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Nathan Goodyear

Intravenous Ascorbate as a Tumor Cytotoxic Chemotherapeutic Agent - 0 views

  • There is a 10 — 100-fold greater content of catalase in normal cells than in tumor cells
  • induce hydrogen peroxide generation
  • Ascorbic acid and its salts (AA) are preferentially toxic to tumor cells in vitro (6 — 13) and in vivo
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  • related to intracellular hydrogen peroxide generation
  • only be obtained by intravenous administration of AA
  • Preferentially kills neoplastic cells
  • Is virtually non-toxic at any dosage
  • Does not suppress the immune system, unlike most chemotherapy agents
  • Increases animal and human resistance to infectious agents by enhancing lymphocyte blastogenesis, enhancing cellular immunity, strengthening the extracellular matrix, and enhancing bactericidal activity of neutrophils and modulation of complement protein
  • Strengthens the structural integrity of the extracellular matrix which is responsible for stromal resistance to malignant invasiveness
  • 1969, researchers at the NCI reported AA was highly toxic to Ehrlich ascites cells in vitro
  • In 1977, Bram et al reported preferential AA toxicity for several malignant melanoma cell lines, including four human-derived lines
  • Noto et al reported that AA plus vitamin K3 had growth inhibiting action against three human tumor cell lines at non-toxic levels
  • Metabolites of AA have also shown antitumor activity in vitro
  • The AA begins to reduce cell proliferation in the tumor cell line at the lowest concentration, 1.76 mg/dl, and is completely cytotoxic to the cells at 7.04 mg/dl
  • the normal cells grew at an enhanced rate at the low dosages (1.76 and 3.52 mg/dl)
  • preferential toxicity of AA for tumor cells. >95% toxicity to human endometrial adenocarcinoma and pancreatic tumor cells (ATCC AN3-CA and MIA PaCa-2) occurred at 20 and 30 mg/dl, respectively.
  • No toxicity or inhibition was demonstrated in the normal, human skin fibroblasts (ATCC CCD 25SK) even at the highest concentration of 50 mg/dl.
  • the use of very high-dose intravenous AA for the treatment of cancer was proposed as early as 1971
  • Cameron and Pauling have published extensive suggestive evidence for prolonged life in terminal cancer patients orally supplemented (with and without initial intravenous AA therapy) with 10 g/day of AA
  • AA, plasma levels during infusion were not monitored,
  • the long-term, oral dosage used in those experiments (10 g/day), while substantial and capable of producing immunostimulatory and extracellular matrix modulation effects, was not high enough to achieve plasma concentrations that are generally cytotoxic to tumor cells in culture
  • This low cytotoxic level of AA is exceedingly rare
  • 5 — 40 mg/dl of AA is required in vitro to kill 100% of tumor cells within 3 days. The 100% kill levels of 30 mg/dl for the endometrial carcinoma cells and 40 mg/dl for the pancreatic carcinoma cells in Figure 2 are typical
  • normal range (95% range) of 0.39-1.13 mg/dl
  • 1 h after beginning his first 8-h infusion of 115 g AA (Merit Pharmaceuticals, Los Angeles, CA), the plasma AA was 3.7 mg/dl and at 5 h was 19 mg/dl. During his fourth 8-h infusion, 8 days later, the 1 h plasma level was 158 mg/dl and 5 h was 185 mg/dl
  • plasma levels of over 100 mg/dl have been maintained in 3 patients for more than 5 h using continuous intravenous infusion
  • In rare instances of patients with widely disseminated and rapidly proliferating tumors, intravenous AA administration (10 — 45 g/day) precipitated widespread tumor hemorrhage and necrosis, resulting in death
  • Although the outcomes were disastrous in these cases, they are similar to the description of tumor-necrosis-factor-induced hemorrhage and necrosis in mice (52) and seem to demonstrate the ability of AA to kill tumor cells in vivo.
  • toxic effects of AA on one normal cell line were observed at 58.36 mg/dl and the lack of side effects in patients maintaining >100 mg/dl plasma levels
  • Although it is very rare, tumor necrosis, hemorrhage, and subsequent death should be the highest priority concern for the safety of intravenous AA for cancer patients.
  • Klenner, who reported no ill effects of dosages as high as 150 g intravenously over a 24-h period
  • Cathcart (55) who describes no ill effects with doses of up to 200 g/d in patients with various pathological conditions
  • following circumstances: renal insufficiency, chronic hemodialysis patients, unusual forms of iron overload, and oxalate stone formers
  • Screening for red cell glucose-6-phosphate dehydrogenase deficiency, which can give rise to hemolysis of red blood cells under oxidative stress (57), should also be performed
  • any cancer therapy should be started at a low dosage to ensure that tumor hemorrhage does not occur.
  • patient is orally supplementing between infusions
  • a scorbutic rebound effect can be avoided with oral supplementation. Because of the possibility of a rebound effect, measurement of plasma levels during the periods between infusions should be performed to ensure that no such effect takes place
  • Every effort should be made to monitor plasma AA levels when a patient discontinues intravenous AA therapy.
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    Older study, 1995, but shows the long-standing evidence that IVC preferentially is cytotoxic to cancer cells.`
Nathan Goodyear

Role of IL-2 in cancer immunotherapy: OncoImmunology: Vol 5, No 6 - 1 views

  • IL-2 is one of the key cytokines with pleiotropic effects on the immune system
  • IL-2 as “T-cell growth factor”
  • approved for the treatment of metastatic renal cell carcinoma (1992) and later for metastatic melanoma (1998) by FDA
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  • It is produced predominately by antigen-simulated CD4+ T cells, while it can also be produced by CD8+ cells, natural killer (NK) cells, and activated dendritic cells (DC)
  • IL-2 is an important factor for the maintenance of CD4+ regulatory T cells
  • plays a critical role in the differentiation of CD4+ T cells into a variety of subsets
  • It can promote CD8+ T-cell and NK cell cytotoxicity activity, and modulate T-cell differentiation programs in response to antigen, promoting naive CD4+ T-cell differentiation into T helper-1 (Th1) and T helper-2 (Th2) cells while inhibiting T helper-17 (Th17) differentiation
  • Of note, Tregs, which act to dampen the immune response, constitutively express high levels of α chain
  • IL-2Rα is unique to IL-2 and is expressed by a number of immune cells including T regulatory cells (Treg), activated CD4+ and CD8+T cells, B cells, mature DCs, endothelial cells
  • some investigators evaluated the efficacy of regimens containing low-dose IL-2
  • IL-2 can promote the activation and cell growth of T and NK cells
  • Unfortunately, not all of patients would benefit from targeted therapy and nearly all patients who initially respond to targeted inhibitors inevitably develop acquired resistance to the treatment
  • IL-2 also stimulates T-regulatory cells that constitutively express CTLA-4 and can suppress immune reactions. Hence, IL-2 might enhance antitumor reactivity in the presence of CTLA-4 blockade
  • both HD and low-dose IL-2 therapy preferentially induce the expansion of CD4+CD25+Foxp3+ Treg and the Treg level remains elevated after each cycle of HD IL-2 therapy
  • Due to rapid elimination and metabolism via the kidney, IL-2 has a short serum half-life of several minutes
  • HD IL-2-induced severe toxicities including vascular leak syndrome (VLS), pulmonary edema, hypotension, and heart toxicities
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    Great historical and functional role of IL-2 in the fight against cancer.
Nathan Goodyear

Abrogation of the Negative Influence of Opioids on IL-2 Immunotherapy of Renal Cell Can... - 0 views

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    only abstract available here to general public.  Opiates suprress the immune system.  This is an important point in the fight against cancer. Cancer is, in part, the result of signficant immune imbalance.  In this study of patients with Renal Cell Cancer, melatonin + IL-2 was found to counter this immunosuppressive effect of morphine to increase partial response and to increase the 3 year survival.
Nathan Goodyear

Hypercalcemia of malignancy and new treatment options - 0 views

  • Hypercalcemia of malignancy occurs as the result of direct bone metastasis and via humoral mechanisms such as parathyroid hormone-related protein (PTHrP) or 1,25-dihydroxyvitamin D mediated pathways
  • ectopic secretion of parathyroid hormone (PTH) has been implicated
  • Hypercalcemia due to osteolytic bone lesions is common in multiple myeloma, leukemia, and breast cancer
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  • Humoral hypercalcemia is predominant in squamous cell, renal cell and ovarian cancers, and lymphomas are associated with 1,25-dihydroxyvitamin D mediated hypercalcemia
  • 20% of cases of hypercalcemia of malignancy and is frequently encountered in multiple myeloma, metastatic breast cancer, and to a lesser extent in leukemia and lymphoma
  • Physiologic bone turnover requires the complementary activity of osteoblasts – mesenchymal stem cell-derived bone-forming cells – and bone-resorbing cells of monocyte and macrophage lineage known as osteoclasts
  • In local osteolytic hypercalcemia, the RANKL/RANK interaction results in excessive osteoclast activation leading to enhanced bone resorption and thus hypercalcemia
  • In addition, osteoclast activation is also mediated by malignancy secreted cytokines, including interleukin-1, initially termed “osteoclast stimulating factor”
  • Macrophage inflammation protein 1-alpha (MIP 1-alpha)
  • hypercalcemia is through extra-renal 1,25-dihydroxyvitamin D (calcitriol) production
  • 1% of cases
  • increased production of 1,25-dihydroxyvitamin D occurs nearly exclusively in Hodgkin and non-Hodgkin lymphoma with case reports of the same in ovarian dysgerminoma
  • 1-α-hydroxylase in the kidney, a process regulated by PTH
  • in 1,25-dihydroxyvitamin D induced hypercalcemia, malignant cells likely recruit and induce adjacent macrophages to express 1-α-hydroxylase, converting endogenous calcidiol into calcitriol.31 Calcitriol then binds to receptors in the intestine leading to heightened enteric calcium reabsorption with resultant hypercalcemia
  • this mechanism of disease is best conceptualized as an absorptive form of hypercalcemia
  • Ectopic production of PTH by malignant cells has been described in a handful of cases involving cancer of the ovary and lung, as well as neuroendocrine tumors and sarcoma
  • primary hyperparathyroidism and malignancy comprising nearly 90% of cases of hypercalcemia
  • an initial panel consisting of PTH, PTHrP, phosphorus, 25-hydroxyvitamin D, and 1,25-dihydroxyvitamin D should be obtained
  • Lymphoma, a hypercalcemia due to 1,25-dihydroxyvitamin D mediated pathways, is implied by elevations in 1,25-dihydroxyvitamin D without concomitant elevations in 25-hydroxyvitamin D. In such cases, PTH is low and PTHrP undetectable
  • Treatment of hypercalcemia of malignancy is aimed at lowering the serum calcium concentration by targeting the underlying disease, specifically by inhibiting bone resorption, increasing urinary calcium excretion, and to a lesser extent by decreasing intestinal calcium absorption
  • mildly symptomatic disease
  • marked symptoms
  • hydration with isotonic fluid (if admitted), avoidance of thiazide diuretics, and a low-calcium diet
  • denosumab
  • Denosumab is an RANKL antibody that inhibits osteoclast maturation, activation, and function
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    hypercalcemia in cancer and treatments.
Nathan Goodyear

Repurposing Drugs in Oncology (ReDO)-chloroquine and hydroxychloroquine as anti-cancer ... - 0 views

  • HCQ, doses for long-term use range between 200 and 400 mg per day.
  • Short-term administration of CQ or HCQ rarely causes severe side effects
  • Short-term administration of CQ or HCQ rarely causes severe side effects
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  • bone marrow suppression
  • cardiomyopathy
  • irreversible retinal toxicity
  • hypoglycaemia
  • daily doses up to 400 mg of HCQ or 250 mg CQ for several years are considered to carry an acceptable risk for CQ-induced retinopathies, with the exception of individuals of short stature
  • chronic CQ or HCQ therapy be monitored through regular ophthalmic examinations (3–6 month intervals), full blood counts and blood glucose level checks
  • long-term HCQ exposure, skeletal muscle function and tendon reflexes should be monitored for weakness
  • both CQ and HCQ, specific caution is advised in patients suffering from impaired hepatic function (especially when associated with cirrhosis), porphyria, renal disease, epilepsy, psoriasis, glucose-6-phosphate dehydrogenase deficiency and known hypersensitivity to 4-aminoquinoline compounds
  • CQ and HCQ can effectively increase the efficacy of various anti-cancer drugs
  • CQ can prevent the entrapment of protonated chemotherapeutic drugs by buffering the extracellular tumour environment and intracellular acidic spaces
  • This study recommends an adjuvant HCQ dose of 600 mg, twice daily.
  • HCQ addition was shown to produce metabolic stress in the tumours
  • HCQ (400 mg/day)
  • important effects of CQ and HCQ on the tumour microenvironment
  • The main and most studied anti-cancer effect of CQ and HCQ is the inhibition of autophagy
  • the expression levels of TLR9 are higher in hepatocellular carcinoma, oesophageal, lung, breast, gastric and prostate cancer cells as compared with adjacent noncancerous cells, and high expression is often linked with poor prognosis
  • TLR9-mediated activation of the NF-κB signalling pathway and the associated enhanced expression of matrix metalloproteinase-2 (MMP-2), MMP-7 and cyclo-oxygenase 2 mRNA
  • HCQ can activate caspase-3 and modulate the Bcl-2/Bax ratio inducing apoptosis in CLL, B-cell CLL and glioblastoma cells
  • In triple-negative breast cancer, CQ was shown to eliminate cancer stem cells through reduction of the expression of Janus-activated kinase 2 and DNA methyl transferase 1 [106] or through induction of mitochondrial dysfunction, subsequently causing oxidative DNA damage and impaired repair of double-stranded DNA breaks
  • CQ or HCQ would be considered for use in combination with immunomodulation anti-cancer therapies
  • Therapies used in combination with CQ or HCQ include chemotherapeutic drugs, tyrosine kinase inhibitors, various monoclonal antibodies, hormone therapies and radiotherapy
  • Most studies hypothesise that CQ and HCQ could increase the efficacy of other anti-cancer drugs by blocking pro-survival autophagy.
  • daily doses between 400 and 1200 mg for HCQ are safe and well tolerated, but two studies identified 600-mg HCQ daily as the MTD
  • HCQ is often administered twice daily to limit plasma fluctuations and toxicity
Nathan Goodyear

Histamine dihydrochloride and low-dose interleukin-2 as post-consolidation im... - 0 views

  • IL-2 is a central T cell-derived cytokine, which induces NK cell and T cell proliferation, differentiation and activation, and also stim-ulates the production of secondary immunostimulatory cytokines
  • combination of histamine and IL-2 thus triggers efficient NK cell-mediated killing of several types of leukemic cells, including freshly recovered human AML blasts
  • histamine improves the effects of IL-2 on T cell activation
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  • principal action of histamine is to protect cytotoxic lymphocytes from myeloid-cell-induced inactivation, thus improving the efficiency of the T and NK cell stimulation achieved by IL-2
  • random-ized Phase II study of patients with renal cell carcinoma further support the suggestion that the combination of HDC and IL-2 improves lymphocyte functions
  • HDC improves the effectiveness of IL-2-induced T and NK cell activation in cancer patients, as predicted in preclinical models
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    histamine dihydrochloride enhances immune effects of NK cells in IL02 therapy; specifically in this analysis in AML, the histamin prevented inactivation of the IL-2 activated NK cells.
Nathan Goodyear

Nivolumab for previously treated unresectable metastatic anal cancer (NCI9673): a multi... - 0 views

  • Patients received a median of six doses of nivolumab
  • four of the first 12 patients had partial responses
  • Nine (24% [95% CI 15–33]) of 37 patients achieved a response (seven partial responses and two complete responses
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  • no treatment-related deaths
  • the most common adverse events were anaemia (26 [70%]), fatigue (25 [68%]), and rash
  • hypothyroidism
  • hypothyroidism
  • nivolumab-related autoimmune hypothyroidism, which resolved after a short course of corticosteroids
  • No grade 3 or 4 adverse events occurred
  • Nivolumab resulted in objective responses in 24% of patients with metastatic SCCA
  • Historically, doublet chemotherapy with cisplatin and fluorouracil has been the most common treatment for patients with metastatic SCCA
  • our results suggest that immune checkpoint blockade agents might extend overall survival beyond currently available therapies, especially if provided early in the disease treatment course
  • the dose of nivolumab we used differs from the 2016 recommendation of a fixed 240 mg every 2 weeks
  • 25% of patients develop distant metastases
  • most patients with localised SCCA are cured by chemoradiation
  • More than 90% of cases of SCCA are linked to prior infection with human papillomavirus (HPV)
  • Within tumour cells, HPV oncoproteins are immunogenic and can trigger an anti-tumour host immune response by recruitment of tumour-infiltrating lymphocytes
  • Tumour cells express PD-L1 and, on binding its inhibitory receptor PD-1 on the surface of T cells, downregulate T-cell activation and thwart the local anti-tumour immune response
  • Nivolumab is a humanised monoclonal antibody against PD-1 that disrupts this interaction, enabling T-cell cytotoxicity. It has activity as a monotherapy in advanced solid cancers, such as head and neck cancer, melanoma, non-small-cell lung cancer, and renal cell carcinoma
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    study finds nivolumab helpful in some patients with surgically unresectable or metastatic anal cancer.  The dose used was 3 mg/kg every 2 weeks. 
Nathan Goodyear

Intravenous vitamin C as a chemotherapy age... [P R Health Sci J. 2004] - PubMed - NCBI - 0 views

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    IV vitamin C shown to be beneficial in treatment of renal cell cancer, colorectal cancer, pancreatic cancer, non-Hodgkin's lymphoma, and breast cancer without toxic side effects.  The doses provided here were high dose and these are patients that are very unhealthy.
Nathan Goodyear

IL-2: The First Effective Immunotherapy for Human Cancer | The Journal of Immunology - 0 views

  • IL-2 is a 15.5-kDa cytokine secreted predominately by Ag-simulated CD4+ T cells, but it can also be produced by CD8+ cells, NK cells, and activated dendritic cells
  • IL-2 is the predominant factor responsible for the maintenance of CD4+ regulatory T cells
  • A generalized capillary leak syndrome was induced by IL-2 in vivo that resulted in interstitial pulmonary infiltrates and substantial weight gain in patients
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  • The side effects were transient and returned to baseline following treatment
  • Tumors do not express IL-2 receptors and thus the antitumor activity was the result of IL-2 stimulation of immune cell
  • Patients with metastatic melanoma or metastatic renal cell cancer were uniquely responsive to high-dose IL-2 administration, and except for patients with advanced non-Hodgkin’s lymphomas (35) only rare responses were seen in patients with other tumor types
  • The underlying toxicity of IL-2 results from a capillary leak that leads to fluid extravasation into visceral organs that can compromise their function
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    Great review of the history of IL-2 in the treatment of cancer.  IL-2 stimulates the immune system to attack cancer.  Don't reinvent the wheel; use what is already present and available.
Nathan Goodyear

Intravenously administered vitamin C as cancer therapy: three cases - 0 views

  • peak plasma concentrations obtained intravenously are estimated to reach 14 000 μmol/L, and concentrations above 2000 μmol/L may persist for several hours
  • Emerging in vitro data show that extracellular ascorbic acid selectively kills some cancer but no normal cells by generating hydrogen peroxide
  • Death is mediated exclusively by extracellular ascorbate, at pharmacologic concentrations that can be achieved only by intravenous administration
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  • Vitamin C may serve as a pro-drug for hydrogen peroxide delivery to extravascular tissues, but without the presence of hydrogen peroxide in blood
  • not all cancer cells were killed by ascorbic acid in vitro
  • Intravascular hemolysis was reported after massive vitamin C administration in people with glucose-6-phosphate dehydrogenase deficiency
  • Administration of high-dose vitamin C to patients with systemic iron overload may increase iron absorption and represents a contraindication
  • Ascorbic acid is metabolized to oxalate, and 2 cases of acute oxalate nephropathy were reported in patients with pre-existing renal insufficiency given massive intravenous doses of vitamin C
  • Rare cases of acute tumour hemorrhage and necrosis were reported in patients with advanced cancer within a few days of starting high-dose intravenous vitamin C therapy, although this was not independently verified by pathologic review
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    IV vitamin C associated with prolonged survival in 3 patients with different cancers.  Peak serum levels reached 14,000 micromol/L, which levels above the 1,000 micro mol/L (cancer cell cytotoxic threshold) were maintained for hours
Nathan Goodyear

Ascorbate in pharmacologic concentrations selectively generates ascorbate radical and h... - 0 views

  • Proposed mechanism
  • The data show that pharmacologic ascorbate concentrations produced Asc•− selectively in extracellular fluid compared with blood and that H2O2 formation occurred when Asc•− concentrations were >100 nM in extracellular fluid.
  • These data validate the hypothesis that ascorbate is a prodrug for selective delivery of reactive species to the extravascular space
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  • pharmacologic ascorbate as a prooxidant drug for therapeutic use.
  • Recently we reported that pharmacologic ascorbic acid concentrations produced H2O2 concentrations of ≥25 μM, causing cancer cell death in vitro
  • We found that H2O2 concentrations generated in vivo were those that caused cancer cell death in vitro
  • When ascorbate was given parenterally, Asc•−, the product of a loss of one electron from ascorbate, was detected preferentially in extracellular fluid compared with blood
  • Asc•− generation in extracellular fluid depended on the ascorbate dose and the resulting concentrations
  • With i.v. administration of ascorbate, Asc•− concentrations were as much as 12-fold greater in extracellular fluid compared to blood and approached 250 nM
  • In blood, such Asc•− concentrations were never produced and were always <50 nM
  • These data are all consistent with the hypothesis that pharmacologic ascorbate concentrations in vivo serve as a prodrug for selective delivery of H2O2 to the extracellular space
  • After oral ingestion, control of intracellular and extracellular ascorbate concentrations is mediated by three mechanisms: intestinal absorption, tissue transport, and renal reabsorption
  • intestinal absorption, or bioavailability, declines at doses >200 mg
    • Nathan Goodyear
       
      significant limitation of gut absorption of vitamin C--at 200 mg po.
  • corresponding to plasma concentrations of ≈60 μM
    • Nathan Goodyear
       
      equates to 0.06 mM.  Max blood levels found with po AA dosing has been 0.22 mM
  • at approximately this concentration, the ascorbate tissue transporter SVCT2 approaches Vmax, and tissues appear to be saturated
    • Nathan Goodyear
       
      SVCT2 Rc in gut reach max binding.
  • also at ≈60 μM, renal reabsorption approaches saturation, and excess ascorbate is excreted in urine
  • Parenteral administration bypasses tight control
  • When tight control is bypassed, H2O2 forms in the extracellular space
  • in vivo validation of ascorbate as a prodrug for selective H2O2 formation
  • Temporarily bypassing tight control with parenteral administration of ascorbate allows H2O2 to form in discrete time periods only, decreasing likelihood of harm, and provides a pharmacologic basis for therapeutic use of i.v. ascorbate
  • H2O2 formation results in selective cytotoxicity
  • Tumor cells are killed with exposure to H2O2 for ≤30 min
  • In vitro, killing is mediated by H2O2 rather than Asc•−
  • In addition to cancer treatment, another potential therapeutic use is for treatment of infections. H2O2 concentrations of 25–50 μM are bacteriostatic
  • virally infected cells may also be candidates
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    follow up invivo study to previous study from 2005.  Here, the authors prove their hypothesis that ascorbate is a prodrug for delivery of H2O2.
Nathan Goodyear

Rare Occurrence of 3 "H": Hypercalcemia, Hemolytic Anemia and Hodgkin's Lymphoma - 0 views

  • administered zoledronic acid (4 mg). Prednisolone (1 mg/kg/day) was started and simultaneously, she was administered first cycle of ABVD (Adriamycin: 25 mg/m2, Bleomycin: 10 U/m2, Vinblastine: 6 mg/m2 and Dacarbazine: 375 mg/m2), which led to normalisation of serum calcium levels over 4 days and improvement in her hemoglobin levels
  • Etiology of anemia in Hodgkin’s lymphoma is multifactorial. Anemia of chronic disease, decreased red cell survival, infiltration of bone marrow by tumor and marrow suppression by chemotherapy/radiotherapy are the common mechanisms
  • Our case had only a transient response to steroids and chemotherapy. Therefore, she was treated with Rituximab which brought hemolysis under control
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  • Hypercalcemia in HL is rare and its incidence has been reported as 0.9, 1.6 and 5.4 % in different series
  • Hypercalcemia of malignancy involves three mechanisms: 1. Humoral hypercalcemia mediated by PTHrP—seen in solid tumors like breast cancer and adult T cell leukemia/lymphoma (ATLL), 2. Direct osteoclast mediated bone resorption due to bony metastasis—seen in solid tumors and multiple myeloma, 3. Calcitriol mediated hypercalcemia—seen in Hodgkin’s and non-Hodgkin’s lymphoma as well as granulomatous disorders like tuberculosis, sarcoidosis, leprosy and disseminated Candidiasis
  • Mechanism of hypercalcemia in HL has long been suggested to involve extra-renal activation of 1α-hydroxylase leading to production of 1, 25(OD)2 Vitamin D3 or Calcitriol, an active metabolite of Vitamin D, which leads to increased re-absorption of calcium and phosphate from intestine, increased osteoclast activation and bone resorption as well as increased phosphate re-absorption in renal tubules
  • The source of 1α-hydroxylase in HL has been postulated as monocytes and macrophages infiltrating the tumor akin to tuberculosis or sarcoidosis and is stimulated by IFN-γ secreted by T-lymphocytes
  • Like sarcoidosis, patients with HL exhibit increased sensitivity to Vitamin D supplements and sunlight, which have been found to precipitate hypercalcemia in these patients
  • Classical biochemical profile in Calcitriol mediated hypercalcemia include: an elevated calcium, normal/slightly elevated phosphate, normal 25(OH) Vitamin D, suppressed PTHrP and PTH, elevated Calcitriol and a normal/increased tubular reabsorption of phosphate
  • not been associated with a poorer prognosis and tends to subside after treatment of the underlying disease
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    great read on hypercalcemia in hodgkin's lymphoma.
Nathan Goodyear

The Long-Term Survival of a Patient With Stage IV Renal Cell Carcinoma Follow... - 0 views

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    Great review of the synergy of IV vitamin C and ALA in this case study.
Nathan Goodyear

High-dose intravenous vitamin C in the treatment of a patient with renal cell carcinoma... - 0 views

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    This is a case study of a patient with cancer of the kidney treated with vitamin C. Therapy was obviously successive in obtaining remission.
Nathan Goodyear

Testosterone and the Cardiovascular System: A Comprehensive Review of the Clinical Lite... - 0 views

  • Low endogenous bioavailable testosterone levels have been shown to be associated with higher rates of all‐cause and cardiovascular‐related mortality.39,41,46–47 Patients suffering from CAD,13–18 CHF,137 T2DM,25–26 and obesity27–28
  • have all been shown to have lower levels of endogenous testosterone compared with those in healthy controls. In addition, the severity of CAD15,17,29–30 and CHF137 correlates with the degree of testosterone deficiency
  • In patients with CHF, testosterone replacement therapy has been shown to significantly improve exercise tolerance while having no effect on LVEF
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  • testosterone therapy causes a shift in the skeletal muscle of CHF patients toward a higher concentration of type I muscle fibers
  • Testosterone replacement therapy has also been shown to improve the homeostatic model of insulin resistance and hemoglobin A1c in diabetics26,68–69 and to lower the BMI in obese patients.
  • Lower levels of endogenous testosterone have been associated with longer duration of the QTc interval
  • testosterone replacement has been shown to shorten the QTc interval
  • negative correlation has been demonstrated between endogenous testosterone levels and IMT of the carotid arteries, abdominal aorta, and thoracic aorta
  • These findings suggest that men with lower levels of endogenous testosterone may be at a higher risk of developing atherosclerosis.
  • Current guidelines from the Endocrine Society make no recommendations on whether patients with heart disease should be screened for hypogonadism and do not recommend supplementing patients with heart disease to improve survival.
  • The Massachusetts Male Aging Study also projects ≈481 000 new cases of hypogonadism annually in US men within the same age group
  • since 1993 prescriptions for testosterone, regardless of the formulation, have increased nearly 500%
  • Testosterone levels are lower in patients with chronic illnesses such as end‐stage renal disease, human immunodeficiency virus, chronic obstructive pulmonary disease, type 2 diabetes mellitus (T2DM), obesity, and several genetic conditions such as Klinefelter syndrome
  • A growing body of evidence suggests that men with lower levels of endogenous testosterone are more prone to develop CAD during their lifetimes
  • There are 2 major potential confounding factors that the older studies generally failed to account for. These factors are the subfraction of testosterone used to perform the analysis and the method used to account for subclinical CAD.
  • The biologically inactive form of testosterone is tightly bound to SHBG and is therefore unable to bind to androgen receptors
  • The biologically inactive fraction of testosterone comprises nearly 68% of the total testosterone in human serum
  • The biologically active subfraction of testosterone, also referred to as bioavailable testosterone, is either loosely bound to albumin or circulates freely in the blood, the latter referred to as free testosterone
  • It is estimated that ≈30% of total serum testosterone is bound to albumin, whereas the remaining 1% to 3% circulates as free testosterone
  • it can be argued that using the biologically active form of testosterone to evaluate the association with CAD will produce the most reliable results
  • English et al14 found statistically significant lower levels of bioavailable testosterone, free testosterone, and free androgen index in patients with catheterization‐proven CAD compared with controls with normal coronary arteries
  • patients with catheterization‐proven CAD had statistically significant lower levels of bioavailable testosterone
  • In conclusion, existing evidence suggests that men with CAD have lower levels of endogenous testosterone,13–18 and more specifically lower levels of bioavailable testosterone
  • low testosterone levels are associated with risk factors for CAD such as T2DM25–26 and obesity
  • In a meta‐analysis of these 7 population‐based studies, Araujo et al41 showed a trend toward increased cardiovascular mortality associated with lower levels of total testosterone, but statistical significance was not achieved (RR, 1.25
  • the authors showed that a decrease of 2.1 standard deviations in levels of total testosterone was associated with a 25% increase in the risk of cardiovascular mortality
  • the relative risk of all‐cause mortality in men with lower levels of total testosterone was calculated to be 1.35
  • higher risk of cardiovascular mortality is associated with lower levels of bioavailable testosterone
  • Existing evidence seems to suggest that lower levels of endogenous testosterone are associated with higher rates of all‐cause mortality and cardiovascular mortality
  • studies have shown that lower levels of endogenous bioavailable testosterone are associated with higher rates of all‐cause and cardiovascular mortality
  • It may be possible that using bioavailable testosterone to perform mortality analysis will yield more accurate results because it prevents the biologically inactive subfraction of testosterone from playing a potential confounding role in the analysis
  • The earliest published material on this matter dates to the late 1930s
  • the concept that testosterone replacement therapy improves angina has yet to be proven wrong
  • In more recent studies, 3 randomized, placebo‐controlled trials demonstrated that administration of testosterone improves myocardial ischemia in men with CAD
  • The improvement in myocardial ischemia was shown to occur in response to both acute and chronic testosterone therapy and seemed to be independent of whether an intravenous or transdermal formulation of testosterone was used.
  • testosterone had no effect on endothelial nitric oxide activity
  • There is growing evidence from in vivo animal models and in vitro models that testosterone induces coronary vasodilation by modulating the activity of ion channels, such as potassium and calcium channels, on the surface of vascular smooth muscle cells
  • Experimental studies suggest that the most likely mechanism of action for testosterone on vascular smooth muscle cells is via modulation of action of non‐ATP‐sensitive potassium ion channels, calcium‐activated potassium ion channels, voltage‐sensitive potassium ion channels, and finally L‐type calcium ion channels
  • Corona et al confirmed those results by demonstrating that not only total testosterone levels are lower among diabetics, but also the levels of free testosterone and SHBG are lower in diabetic patients
  • Laaksonen et al65 followed 702 Finnish men for 11 years and demonstrated that men in the lowest quartile of total testosterone, free testosterone, and SHBG were more likely to develop T2DM and metabolic syndrome.
  • Vikan et al followed 1454 Swedish men for 11 years and discovered that men in the highest quartile of total testosterone were significantly less likely to develop T2DM
  • authors demonstrated a statistically significant increase in the incidence of T2DM in subjects receiving gonadotropin‐releasing hormone antagonist therapy. In addition, a significant increase in the rate of myocardial infarction, stroke, sudden cardiac death, and development of cardiovascular disease was noted in patients receiving antiandrogen therapy.67
  • Several authors have demonstrated that the administration of testosterone in diabetic men improves the homeostatic model of insulin resistance, hemoglobin A1c, and fasting plasma glucose
  • Existing evidence strongly suggests that the levels of total and free testosterone are lower among diabetic patients compared with those in nondiabetics
  • insulin seems to be acting as a stimulant for the hypothalamus to secret gonadotropin‐releasing hormone, which consequently results in increased testosterone production. It can be argued that decreased stimulation of the hypothalamus in diabetics secondary to insulin deficiency could result in hypogonadotropic hypogonadism
  • BMI has been shown to be inversely associated with testosterone levels
  • This interaction may be a result of the promotion of lipolysis in abdominal adipose tissue by testosterone, which may in turn cause reduced abdominal adiposity. On the other hand, given that adipose tissue has a higher concentration of the enzyme aromatase, it could be that increased adipose tissue results in more testosterone being converted to estrogen, thereby causing hypogonadism. Third, increased abdominal obesity may cause reduced testosterone secretion by negatively affecting the hypothalamus‐pituitary‐testicular axis. Finally, testosterone may be the key factor in activating the enzyme 11‐hydroxysteroid dehydrogenase in adipose tissue, which transforms glucocorticoids into their inactive form.
  • increasing age may alter the association between testosterone and CRP. Another possible explanation for the association between testosterone level and CRP is central obesity and waist circumference
  • Bai et al have provided convincing evidence that testosterone might be able to shorten the QTc interval by augmenting the activity of slowly activating delayed rectifier potassium channels while simultaneously slowing the activity of L‐type calcium channels
  • consistent evidence that supplemental testosterone shortens the QTc interval.
  • Intima‐media thickness (IMT) of the carotid artery is considered a marker for preclinical atherosclerosis
  • Studies have shown that levels of endogenous testosterone are inversely associated with IMT of the carotid artery,126–128,32,129–130 as well as both the thoracic134 and the abdominal aorta
  • 1 study has demonstrated that lower levels of free testosterone are associated with accelerated progression of carotid artery IMT
  • another study has reported that decreased levels of total and bioavailable testosterone are associated with progression of atherosclerosis in the abdominal aorta
  • These findings suggest that normal physiologic testosterone levels may help to protect men from the development of atherosclerosis
  • Czesla et al successfully demonstrated that the muscle specimens that were exposed to metenolone had a significant shift in their composition toward type I muscle fibers
  • Type I muscle fibers, also known as slow‐twitch or oxidative fibers, are associated with enhanced strength and physical capability
  • It has been shown that those with advanced CHF have a higher percentage of type II muscle fibers, based on muscle biopsy
  • Studies have shown that men with CHF suffer from reduced levels of total and free testosterone.137 It has also been shown that reduced testosterone levels in men with CHF portends a poor prognosis and is associated with increased CHF mortality.138 Reduced testosterone has also been shown to correlate negatively with exercise capacity in CHF patients.
  • Testosterone replacement therapy has been shown to significantly improve exercise capacity, without affecting LVEF
  • the results of the 3 meta‐analyses seem to indicate that testosterone replacement therapy does not cause an increase in the rate of adverse cardiovascular events
  • Data from 3 meta‐analyses seem to contradict the commonly held belief that testosterone administration may increase the risk of developing prostate cancer
  • One meta‐analysis reported an increase in all prostate‐related adverse events with testosterone administration.146 However, when each prostate‐related event, including prostate cancer and a rise in PSA, was analyzed separately, no differences were observed between the testosterone group and the placebo group
  • the existing data from the 3 meta‐analyses seem to indicate that testosterone replacement therapy does not increase the risk of adverse cardiovascular events
  • the authors correctly point out the weaknesses of their study which include retrospective study design and lack of randomization, small sample size at extremes of follow‐up, lack of outcome validation by chart review and poor generalizability of the results given that only male veterans with CAD were included in this study
    • Nathan Goodyear
       
      The authors here present Total Testosterone as a "confounding" value
    • Nathan Goodyear
       
      This would be HSD-II
  • the studies that failed to find an association between testosterone and CRP used an older population group
  • low testosterone may influence the severity of CAD by adversely affecting the mediators of the inflammatory response such as high‐sensitivity C‐reactive protein, interleukin‐6, and tumor necrosis factor–α
  •  
    Good review of Testosterone and CHD.  Low T is associated with increased all cause mortality and cardiovascular mortality, CAD, CHF, type II diabetes, obesity, increased IMT,  increased severity of CAD and CHF.  Testosterone replacement in men with low T has been shown to improve exercise tolerance in CHF, improve insulin resistance, improve HgbA1c and lower BMI in the obese.
Nathan Goodyear

Stool Microbiome Profiling of Patients with Metastatic Renal Cell Carcinoma Receiving A... - 0 views

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    Gut microbiome diversity associated with increase in immunotherapy efficacy; particularly akermansia
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