Skip to main content

Home/ Dr. Goodyear/ Group items matching ""plasma concentration"" in title, tags, annotations or url

Group items matching
in title, tags, annotations or url

Sort By: Relevance | Date Filter: All | Bookmarks | Topics Simple Middle
Nathan Goodyear

Fifty- two-Week Treatment With Diet and Exercise Plus Transdermal Testosterone Reverses the Metabolic Syndrome and Improves Glycemic Control in Men With Newly Diagnosed Type 2 Diabetes and Subnormal Plasma Testosterone - Heufelder - 2013 - Journal of Andr - 0 views

onlinelibrary.wiley.com/...full

diet exercise nutrition diabetes metabolic syndrome men male hormone hormones low T low Testosterone

shared by Nathan Goodyear on 04 Mar 15 - No Cached
  • there appears to be a positive correlation between serum testosterone levels and insulin sensitivity in men across the full spectrum of glucose tolerance (Pitteloud et al, 2005), and this relationship is at least partially direct and not fully dependent on (changes in) elements of the MetS
  • supervised D&E alone led to significant improvements in testosterone concentrations, glycemic control, and components of the MetS
  • diet control, exercise, and testosterone supplementation may be beneficial in the management of men with T2D
  • ...7 more annotations...
  • androgen-deprivation therapy in males with prostatic cancer may be associated with an increased risk for T2D, which may be caused by negative effects on insulin sensitivity
  • insulin sensitivity, measured by HOMA, improved in both groups and with a significantly greater degree when testosterone was added to supervised D&E
  • Fasting insulin concentrations, a good representative of insulin sensitivity, did show a significant correlation with changes in circulating androgen levels, an observation in support of Pitteloud et al (2005), who showed a direct relationship between insulin sensitivity and circulating testosterone concentrations using the hyper-insulinemic euglycemic clamp technique
  • 52 weeks of testosterone treatment also significantly improved circulation levels of adiponectin and hsCRP, key serum markers of insulin sensitivity and hepatic steatosis
  • The changes in both adiponectin and hsCRP were significantly correlated with the therapy-induced changes in bioavailable testosterone
  • a negative correlation was found between hsCRP levels and bioavailable testosterone
  • serum PSA concentrations did not differ between the 2 treatment groups, indicating that short-term testosterone administration appears to be acceptably safe
  • Nathan Goodyear on 04 Mar 15
     
    Study of men with metabolic syndrome and type II Diabetes finds that diet and exercise alone improved glucose control and metabolic syndrome components by 31%.  The addition of Testosterone therapy increased this % to 81%.
Nathan Goodyear

Vitamin C and cancer revisited - 0 views

www.ncbi.nlm.nih.gov/...PMC2516245

IV vitamin C cancer vitamin C H2O2 hydrogen peroxide Fe

shared by Nathan Goodyear on 05 Mar 18 - No Cached
  • It is well known that vitamin C, or ascorbic acid, is an effective biologic antioxidant and does not act as a pro-oxidant under normal conditions (5) because it does not readily autoxidize, i.e., react with oxygen (O2) to produce reactive oxygen species, such as superoxide radicals (O2•−) or H2O2
  • However, ascorbate readily donates an electron to redox-active transition metal ions, such as cupric (Cu2+) or ferric (Fe3+) ions, reducing them to cuprous (Cu+) and ferrous (Fe2+) ions, respectively
  • Reduced transition metal ions, in contrast to ascorbic acid, readily react with O2, reducing it to superoxide radicals (Reaction 2), which in turn dismutate to form H2O2 and O2
  • ...6 more annotations...
  • The H2O2 produced this way (Reactions 1–3) seems to be key to ascorbate's antitumor effect because H2O2 causes cancer cells to undergo apoptosis, pyknosis, and necrosis
  • In contrast, normal cells are considerably less vulnerable to H2O2
  • The reason for the increased sensitivity of tumor cells to H2O2 is not clear but may be due to lower antioxidant defenses
  • In fact, a lower capacity to destroy H2O2—e.g., by catalase, peroxiredoxins, and GSH peroxidases—may cause tumor cells to grow and proliferate more rapidly than normal cells in response to low concentrations of H2O2
  • These observations, combined with the inhibitory effect on xenograft growth, provide the proof of concept that millimolar concentrations of extracellular ascorbate, achievable by i.p. injection or i.v. infusion in experimental animals and humans, respectively, exert pro-oxidant, antitumor effects in vivo.
  • They also show that the concentration of the ascorbyl radical correlates with the concentration of H2O2 in interstitial fluid, whereas no H2O2 can be detected in blood or plasma
  • Nathan Goodyear on 05 Mar 18
     
    review of the mechanism of how extracellular AA, only obtainable from parenteral dosing, can produce H2O2 extracellularly to then be cytotoxic to cancer cells.
Nathan Goodyear

Vitamin C preferentially kills cancer stem cells in hepatocellular carcinoma via SVCT-2 | npj Precision Oncology - 0 views

www.nature.com/...s41698-017-0044-8

cancer cancer stem cells liver cancer vitamin C IV vitamin C oncology

shared by Nathan Goodyear on 30 Jan 18 - No Cached
  • Chen et al. have revealed that ascorbate at pharmacologic concentrations (0.3–20 mM) achieved only by intravenously (i.v.) administration selectively kills a variety of cancer cell lines in vitro, but has little cytotoxic effect on normal cells.
  • Ascorbic acid (the reduced form of vitamin C) is specifically transported into cells by sodium-dependent vitamin C transporters (SVCTs)
  • SVCT-1 is predominantly expressed in epithelial tissues
  • ...41 more annotations...
  • whereas the expression of SVCT-2 is ubiquitous
  • differential sensitivity to VC may result from variations in VC flow into cells, which is dependent on SVCT-2 expression.
  • high-dose VC significantly impaired both the tumorspheres initiation (Fig. 4d, e) and the growth of established tumorspheres derived from HCC cells (Fig. 4f, g) in a time-dependent and dose-dependent manner.
  • Hepatocellular carcinoma (HCC)
  • The antioxidant, N-acetyl-L-cysteine (NAC), preventing VC-induced ROS production (a ROS scavenger), completely restored the viability and colony formation among VC-treated cells
  • DNA double-strand damage was found following VC treatment
  • DNA damage was prevented by NAC
  • Interestingly, the combination of VC and cisplatin was even more effective in reducing tumor growth and weight
  • Consistent with the in vitro results, stemness-related genes expressions in tumor xenograft were remarkably reduced after VC or VC+cisplatin treatment, whereas conventional cisplatin therapy alone led to the increase of CSCs
  • VC is one of the numerous common hepatoprotectants.
  • Interestingly, at extracellular concentrations greater than 1 mM, VC induces strong cytotoxicity to cancer cells including liver cancer cells
  • we hypothesized that intravenous VC might reduce the risk of recurrence in HCC patients after curative liver resection.
  • Intriguingly, the 5-year disease-free survival (DFS) for patients who received intravenous VC was 24%, as opposed to 15% for no intravenous VC-treated patients
  • Median DFS time for VC users was 25.2 vs. 18 months for VC non-users
  • intravenous VC use is linked to improved DFS in HCC patients.
  • In this study, based on the elevated expression of SVCT-2, which is responsible for VC uptake, in liver CSCs, we revealed that clinically achievable concentrations of VC preferentially eradicated liver CSCs in vitro and in vivo
    • Nathan Goodyear
      Nathan Goodyear on 31 Jan 18
       
      the authors here made similar mistakes to the Mayo authors i.e. under doses here in this study.  They dosed at only 2 grams IVC.  A woefully low dose of IVC.
  • Additionally, we found that intravenous VC reduced the risk of post-surgical HCC progression in a retrospective cohort study.
    • Nathan Goodyear
      Nathan Goodyear on 31 Jan 18
       
      positive results despite a low dose used.
    • Nathan Goodyear
      Nathan Goodyear on 31 Jan 18
       
      Their comfort zone was 1mM.  They should have targeted 20-40 mM.
  • Three hundred thirty-nine participants (55.3%) received 2 g intravenous VC for 4 or more days after initial hepatectomy
  • As the key protein responsible for VC uptake in the liver, SVCT-2 played crucial roles in regulating the sensitivity to ascorbate-induced cytotoxicity
  • we also observed that SVCT-2 was highly expressed in human HCC samples and preferentially elevated in liver CSCs
  • SVCT-2 might serve as a potential CSC marker and therapeutic target in HCC
  • CSCs play critical roles in regulating tumor initiation, relapse, and chemoresistance
  • we revealed that VC treatment dramatically reduced the self-renewal ability, expression levels of CSC-associated genes, and percentages of CSCs in HCC, indicating that CSCs were more susceptible to VC-induced cell death
  • as a drug for eradicating CSCs, VC may represent a promising strategy for treatment of HCC, alone or particularly in combination with chemotherapeutic drugs
  • In HCC, we found that VC-generated ROS caused genotoxic stress (DNA damage) and metabolic stress (ATP depletion), which further activated the cyclin-dependent kinase inhibitor p21, leading to G2/M phase cell cycle arrest and caspase-dependent apoptosis in HCC cells
  • we demonstrated a synergistic effect of VC and chemotherapeutic drug cisplatin on killing HCC both in vitro and in vivo
  • Intravenous VC has also been reported to reduce chemotherapy-associated toxicity of carboplatin and paclitaxel in patients,38 but the specific mechanism needs further investigation
    • Nathan Goodyear
      Nathan Goodyear on 31 Jan 18
       
      so, exclude the benefit to patients until the exact mechanism of action, which will never be fully elicited?!?!?
  • Our retrospective cohort study also showed that intravenous VC use (2 g) was related to the improved DFS in HCC patients after initial hepatectomy
    • Nathan Goodyear
      Nathan Goodyear on 31 Jan 18
       
      Terribly inadequate dose.  Target is 20-40 mM which other studies have found occur with 50-75 grams of IVC.
  • several clinical trials of high-dose intravenous VC have been conducted in patients with advanced cancer and have revealed improved quality of life and prolonged OS
  • high-dose VC was not toxic to immune cells and major immune cell subpopulations in vivo
  • high recurrence rate and heterogeneity
  • tumor progression, metastasis, and chemotherapy-resistance
  • SVCT-2 was highly expressed in HCC samples in comparison to peri-tumor tissues
  • high expression (grade 2+/3+) of SVCT-2 was in agreement with poorer overall survival (OS) of HCC patients (Fig. 1c) and more aggressive tumor behavior
  • SVCT-2 is enriched in liver CSCs
  • these data suggest that SVCT-2 is preferentially expressed in liver CSCs and is required for the maintenance of liver CSCs.
  • pharmacologic concentrations of plasma VC higher than 0.3 mM are achievable only from i.v. administration
  • The viabilities of HCC cells were dramatically decreased after exposure to VC in dose-dependent manner
  • VC and cisplatin combination further caused cell apoptosis in tumor xenograft
  • These results verify that VC inhibits tumor growth in HCC PDX models and SVCT-2 expression level is associated with VC response
  • qPCR and IHC analysis demonstrated that expression levels of CSC-associated genes and percentages of CSCs in PDXs dramatically declined after VC treatment, confirming the inhibitory role of VC in liver CSCs
  • Nathan Goodyear on 30 Jan 18
     
    IV vitamin C in vitro and in vivo found to "preferentially" eradicate cancer stem cells.  In addition, IV vitamin C was found to be adjunctive to chemotherapy, found to be hepatoprotectant.  This study also looked at SVCT-2, which is the transport protein important in liver C uptake.
Nathan Goodyear

Steroids in Saliva for Assessing Endocrine Function - 0 views

edrv.endojournals.org/...367.abstract

saliva salivary hormone hormones testing

shared by Nathan Goodyear on 25 Jun 13 - No Cached
  • Nathan Goodyear on 25 Jun 13
     
    Another study validates saliva as a reliable method for hormone testing.  The author concludes: "steroid concentrations in saliva are independent of flow rate and reflect those in the free fraction in plasma".  This study also discuss potential collection problems and means to resolve them.
Nathan Goodyear

SALIVARY CORTISOL ASSAYS FOR ASSESSING PITUITARY-ADRENAL RESERVE - PETERS - 2008 - Clinical Endocrinology - Wiley Online Library - 0 views

onlinelibrary.wiley.com/...abstract

saliva salivary hormone hormones testing evaluation cortisol

shared by Nathan Goodyear on 30 Apr 12 - No Cached
  • Since salivary cortisol concentrations were shown to reflect the free, biologically active fraction in plasma, salivary assay may, in selected cases, provide results of greater diagnostic significance than plasma total concentrations.
  • Nathan Goodyear on 30 Apr 12
     
    salivary cortisol found to be superior to total serum cortisol levels.
Nathan Goodyear

Vitamin C Pharmacokinetics: Implications for Oral and Intravenous Use - 0 views

www.annals.org/...533.short

IV intravenous vitamin C therapy treatment minerals vitamins

shared by Nathan Goodyear on 22 Nov 11 - No Cached
  • Nathan Goodyear on 22 Nov 11
     
    only high dose IV vitamin C shown to produce high plasma vitamin C concentrations compared to oral vitamin c.
Nathan Goodyear

The role of vitamin C in the treatment of pain: new insights - 0 views

www.ncbi.nlm.nih.gov/...PMC5391567

vitamin C pain arthritis

shared by Nathan Goodyear on 18 Sep 17 - No Cached
  • recommended that during illness one should be careful about the intake of vitamin C, keeping in mind that acute illness rapidly depletes stores of ascorbic acid
  • it is possible that other hospital-associated pain may be partly due to vitamin C deficiency, which is relatively prevalent in hospital settings
  • Vitamin C deficiency (defined as plasma vitamin C concentrations <11 µmol/L
  • ...5 more annotations...
  • Vitamin C is cost effective and appears to be a safe and effective adjunctive therapy for specific pain relief
  • it decreases the requirement for opioid analgesics, particularly post surgically and for bone metastasis
  • recent research has indicated a positive impact of high dose vitamin C on cancer- and chemotherapy-related quality of life, including pain
  • Cameron and Campbell [81] reported a number of cases of dramatic to complete amelioration of bone pain in patients with severe cancer-related pain given both high dose oral and intravenous vitamin C
  • hypovitaminosis C (defined as plasma vitamin C concentrations <23 µmol/L
  • Nathan Goodyear on 18 Sep 17
     
    vitamin C reduces pain; mechanism of action likely anti-inflammatory antioxidant, but yet inconclusive.
Nathan Goodyear

Effect of Ascorbate on the Activity of Hypoxia-inducible Factor in Cancer Cells | Cancer Research - 0 views

cancerres.aacrjournals.org/...1764.long

Hypoxia-inducible Factor 1 Fe HIF-1 iron vitamin C HIF-1alpha cancer

shared by Nathan Goodyear on 01 Apr 21 - No Cached
  • Nathan Goodyear on 01 Apr 21
     
    "Ascorbate at physiological concentrations (25 μm) strikingly suppressed HIF-1α protein levels and HIF transcriptional targets, particularly when the system was oncogenically activated in normoxic cells. Similar results were obtained with iron supplementation" Here, physiologic levels of plasma AA decrease HIF-1alpha activity.
Nathan Goodyear

Pharmacokinetic modeling of ascorbate diffusion through normal and tumor tissue - PubMed - 0 views

pubmed.ncbi.nlm.nih.gov/25277418

vitamin C pharmacokinetics cancer

shared by Nathan Goodyear on 25 Nov 21 - No Cached
  • Nathan Goodyear on 25 Nov 21
     
    supraphysiological plasma ascorbate concentrations (>100 μM) are required to achieve effective delivery of ascorbate to poorly vascularized tumor tissue
Nathan Goodyear

The Role of Vitamin C in Human Immunity and Its Treatment Potential Against COVID-19: A Review Article - PMC - 0 views

www.ncbi.nlm.nih.gov/...PMC9925039

COVID-19 SARS-CoV-2 COVID WBC ascorbic acid vitamin C

shared by Nathan Goodyear on 01 Sep 23 - No Cached
  • vitamins A, B, C, E, B6, B12, folate, zinc, iron, copper, and selenium
  • White blood cells, including neutrophils and monocytes, accumulate concentrations of vitamin C up to 100 times greater than that of plasma
  • Vitamin C is a crucial component of both the innate (nonspecific) and adaptive (specific) portions of the immune system
  • ...52 more annotations...
  • play a role during the initial chemotactic response of neutrophils shortly after infection
  • following vitamin C supplementation, a 20% increase in neutrophil chemotactic activity was observed
  • also contributes to the phagocytosis and killing of microbes by neutrophils
  • low levels of vitamin C occurring in high-stress situations
  • maturation, proliferation, and viability of T cells have all been shown to be upregulated by the presence of normal physiologic concentrations of vitamin C
  • Vitamin C has been shown to directly affect the number of Igs released from B cells
  • vitamin C among healthy young adult males showed a significant increase in serum levels of IgA, IgG, and IgM
  • effects of high-dose vitamin C on cytokine levels in cancer patients, finding decreased amounts of the cytokines Interleukin-1 alpha (IL-1 alpha), IL-2, IL-8, and tumor necrosis factor-alpha (TNF-alpha) after high-dose vitamin C infusion
  • when vitamin C was supplemented with vitamin E in healthy adults, it increased the production of cytokines IL-1 beta and TNF-alpha
  • vitamin C acts to modulate the levels of cytokines to prevent them from fluctuating in either direction
  • vitamin C also acts as an important antioxidant to the cells of the immune system.
  • human leukocytes, neutrophils, in particular, possess the ability to transport the oxidized form of vitamin C across its membrane to use as a defense mechanism against ROS produced during an immune response
  • Vitamin C also can recover other endogenous antioxidants in the body such as vitamin E and glutathione, returning them to their active state
  • vitamin C can decrease the activation of NF-kB
  • can reduce harmful nitrogen-based compounds such as N-nitrosamines and nitrosamides, both of which are carcinogenic 
  • subjects taking oral vitamin C supplementation saw a 60% to 90% reduction in oxidative stress compared to a placebo control
  • subjects infused with vitamin C alone had a 516% increase in glutathione levels compared to subjects not provided the 500 mg daily supplementation
  • hydroxylating proline and lysine
  • mature and stabilize the tissue of a healing wound
  • healing
  • oral surgery
  • improved soft tissue regeneration
  • vitamin C increases the mRNA levels of type I and type III collagen in the human dermis
  • Studies have demonstrated that those with low levels of vitamin C are at a significantly higher risk of respiratory infection compared to those with normal levels
  • viral cold duration was reduced by about 8% in adults and 13.5% in children using prophylactic daily doses of 200 mg of oral vitamin C
  • prophylactically supplementing vitamin C decreases the risk of infection with respiratory viruses such as the common cold
  • combined with probiotics, oral vitamin C supplementation showed a 33% decrease in the incidence of respiratory tract infections in preschool-age children [
  • high-dose oral supplementation of vitamin C managed to prevent or reduce symptoms if taken before or just after the onset of cold- or flu-like symptoms
  • improvements in oxygen saturation and decreased IL-6 levels (a marker of inflammation) in the treatment group compared to the control group
  • 8 g doses of oral vitamin C
  • there is a negative correlation between age and serum levels of vitamin C
  • Patients with COVID-19 will likely also experience depletion in serum levels of vitamin C as a direct result of the upregulation of the immune system to combat the infection
  • Colunga et al. suggested that oral vitamin C can be combined with oral Quercetin, an antiviral flavonoid, to improve Quercetin’s ability to block viral membrane fusion of SARS-CoV-2
  • high doses of 1-2 g/day of oral vitamin C could prevent other upper respiratory infections
  • It appears vitamin C supplementation by itself does not provide a striking benefit in preventing COVID-19 infection for those without a deficiency
    • Nathan Goodyear
      Nathan Goodyear on 01 Sep 23
       
      Flawed statement. What is normal? Vitamin D. Many variables effect levels and dose, including the two compartment kinetics and absorption.
  • Hiedra et al. were able to show decreases in inflammatory biomarkers, such as D-dimer and ferritin
  • some evidence to support that prophylactic use of vitamin C helps reduce the severity of respiratory infection symptoms once a subject has already been infected
  • oral vitamin C in combination with zinc provided the largest amount of antibody titers 42 days
  • linear relationship between days of vitamin C therapy and survival duration
  • other studies were unable to find any definitive improvement concerning therapy with vitamin C
    • Nathan Goodyear
      Nathan Goodyear on 01 Sep 23
       
      Either these studies are designed to fail or the authors are lacking some basic understanding of pharmacokinetics and pharmacodynamics with vitamin C.
  • Fowler et al. aimed to see if a high-dose vitamin C infusion would benefit patients affected by ARDS, but they were unable to conclude that vitamin C infusion, compared to a placebo, could decrease vascular inflammation and damage in ARDS
    • Nathan Goodyear
      Nathan Goodyear on 01 Sep 23
       
      At what dose, duration, frequency???
  • in a sample of 67 COVID-19-positive ICU patients, 82% of them displayed plasma vitamin C levels below 0.4 mg/dL
    • Nathan Goodyear
      Nathan Goodyear on 01 Sep 23
       
      They are kind of make the point from my earlier note.
  • continuous vitamin C infusion at a rate of 60 mg/kg/day for four days decreased the need for mechanical ventilation and vasopressor use but had no significant effect on overall mortality
    • Nathan Goodyear
      Nathan Goodyear on 01 Sep 23
       
      Again, designed to fail or ignorance designed the study which failed
  • Carr et al. suggested that high-dose IV vitamin C is most effective when treating sepsis as septic patients receiving the normal daily recommendations through diet still showed decreased vitamin C levels
  • High-dose IV vitamin C treatment has also been shown by Kakodkar et al. to decrease syndecan-1, an endothelial glycocalyx that contributes to mortality in septic patients
  • combined with hydrocortisone and thiamine, septic patients treated with 1.5 g of IV vitamin C every six hours showed a distinct decrease in their SOFA scores and none of the patients treated developed organ failure
  • combined with hydrocortisone and thiamine, septic patients treated with 1.5 g of IV vitamin C every six hours showed a distinct decrease in their SOFA scores and none of the patients treated developed organ failure
  • reduced overall mortality
  • reduced overall mortality
  • propose the use for high-dose vitamin C to aid in the treatment of septic shock-induced hypotension
  • treatment of severe sepsis using a high dose (up to 200 mg/kg/day) of IV vitamin C was explored in phase I, a double-blind, randomized, placebo-controlled trial by Fowler et al. [75]. Their findings included a reduction in SOFA scores and decreased vascular injury compared to a placebo control group, all while showing minimal adverse side effects
    • Nathan Goodyear
      Nathan Goodyear on 01 Sep 23
       
      High dose here is laughable. Again, duration and frequency also.
  • Maintaining a daily intake of 75 and 100 mg for men and women, respectively, as recommended by the U.S. Institute of Medicine
    • Nathan Goodyear
      Nathan Goodyear on 01 Sep 23
       
      This recommendation is FRANK IGNORANCE
Nathan Goodyear

Concentrations of total and free dehydroepiandrosterone in plasma and dehydroepiandrosterone in saliva of normal and hirsute women under basal conditions and during administration of dexamethasone/synthetic corticotropin -- Swinkels et al. 36 (12): 2042 - - 0 views

www.clinchem.org/...2042

dehydroepiandrosterone saliva testing salivary adrenal function secretion

shared by Nathan Goodyear on 20 Jan 11 - No Cached
  • Nathan Goodyear on 20 Jan 11
     
    Conclusion: "the concentration of DHEA in saliva is a reliable index of adrenal DHEA secretion..."
Nathan Goodyear

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

www.ncbi.nlm.nih.gov/...PMC1405876

IV vitamin C vitamin C cancer

shared by Nathan Goodyear on 24 Apr 17 - No Cached
  • 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
  • ...6 more annotations...
  • 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
  • Nathan Goodyear on 24 Apr 17
     
    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

Vitamin C Research - IVC Protocol | The Riordan Clinic - 0 views

www.riordanclinic.org/...protocol

IV vitamin C vitamin C IV intravenous Riordan clinic

shared by Nathan Goodyear on 18 Jun 13 - No Cached
  • therapeutic goal of reaching a peak-plasma concentration of ~20 mM (350- 400 mg/dL) is most efficacious
  • The first post IVC plasma level following the 15 gram IVC has been shown to be clinically instructive: levels below 100 mg/dL correlate with higher levels of existent oxidative stress, presumably from higher tumor burden, chemo/radiation damage, hidden infection, or other oxidative insult, such as smoking.
  • If after four infusions the post IVC dosage remains sub-therapeutic, the patient may have an occult infection, may be secretly smoking, or may have tumor progression
  • Nathan Goodyear on 18 Jun 13
     
    IV vitamin C protocol and review of experience from the Riordan Clinic.
Nathan Goodyear

The adipose tissue metabolism: role of testosterone and dehydroepiandrosterone. - PubMed - NCBI - 0 views

www.ncbi.nlm.nih.gov/...10997611

Testosterone DHEA lipoprotein lipase adipose tissue hormones

shared by Nathan Goodyear on 17 Jun 15 - No Cached
  • T inhibits lipid uptake and lipoprotein-lipase (LDL) activity in adipocytes, and stimulates lipolysis
  • T inhibits differentiation of adipocyte precursor cells
  • DHEA stimulates resting metabolic rate (RMR) and lipid oxidation, and enhances glucose disposal, by increasing the expression of GLUT-1 and GLUT-4 on fat cell plasma membrane
  • ...2 more annotations...
  • The insulin-like effect of DHEA would be associated to a decrease of plasma insulin concentrations and, thus, to an increase of the molar ratio between lipolytic hormones and insulin
  • the fat-reducing effect of both T and DHEA seems to be more evident at the level of visceral adipose tissue
  • Nathan Goodyear on 17 Jun 15
     
    Testosterone inhibits lipid uptake into adipocytes.  Testosterone inhibits lipoprotein lipase.  Testosterone stimulated lipolysis.  Testosterone inhibits adipocyte differentiation of proginator cells. DHEAs effects are through different mechanisms.   Both have a preference for activity with visceral adipose tissue.
Nathan Goodyear

Replacement therapy for hypothyroidism with thyrox... [J Clin Invest. 1995] - PubMed result - 0 views

www.ncbi.nlm.nih.gov/...8675653

hypothyroidism replacement therapy T4 T3

shared by Nathan Goodyear on 08 Mar 11 - No Cached
  • No single dose of T4 was able to restore normal plasma thyrotropin, T4 and T3, as well as T4 and T3 in all tissues, or at least to restore T3 simultaneously in plasma and all tissues. Moreover, in most tissues, the dose of T4 needed to ensure normal T3 levels resulted in supraphysiological T4 concentrations.
  • Nathan Goodyear on 08 Mar 11
     
    replacement therapy for hypothyroidism must include both T4 and T3
Nathan Goodyear

ScienceDirect - American Heart Journal : Plasma total cysteine and total homocysteine and risk of myocardial infarction in women: A prospective study - 0 views

www.sciencedirect.com/...S0002870310000815

elevated homocysteine MI risk cardiac

shared by Nathan Goodyear on 03 Aug 11 - No Cached
  • Fasting homocysteine was positively associated with MI risk
  • Fasting plasma concentration of total homocysteine, but not total cysteine, was positively associated with MI risk.
  • Nathan Goodyear on 03 Aug 11
     
    homocysteine associated with MI risk
Nathan Goodyear

Comparisons of normal saline and lactated Ringer's resuscitation on hemodynamics, metabolic responses, and coagulation in pigs after severe hemorrhagic shock - 0 views

www.ncbi.nlm.nih.gov/...PMC4029282

IV fluids lactated ringers normal saline LR NS

shared by Nathan Goodyear on 03 Jul 18 - No Cached
  • NS contains 154 mM Na+ and Cl-, with an average pH of 5.0 and osmolarity of 308 mOsm/L.
  • LR solution has an average pH of 6.5, is hypo-osmolar (272 mOsm/L), and has similar electrolytes (130 mM Na+, 109 mM Cl-, 28 mM lactate, etc.) to plasma
  • hyperchloremic acidosis
  • ...26 more annotations...
  • LR’s acid base balance is superior to that of NS’s
  • There were no significant differences between LR and NS groups in fibrinogen concentrations or platelet count
  • Total protein dropped
  • no significant differences in Hct (Table  1) or total protein between LR and NS groups
  • Bicarbonate HCO3- levels were decreased by hemorrhage but returned to pre-hemorrhage values by 3 h after LR resuscitation, whereas no return was observed with NS resuscitation
  • Na+ was increased after NS resuscitation
  • No changes in Na+ or K+ were observed
  • K+ did not change initially after NS resuscitation but was elevated at 6 h afterwards
  • Ca++ was similarly decreased
  • Cl- was elevated for 6 h after NS resuscitation, with no changes shown after LR resuscitation
  • PT was similarly prolonged by resuscitation with LR (from 11.2 ± 0.2 sec at baseline to 12.1 ± 0.2 sec at 6 h) and NS
  • Plasma aPTT was also similarly prolonged by resuscitation with LR (from 17.1 ± 0.5 sec baseline to 20.1 ± 1.2 sec at 6 h) or NS
  • NS resuscitation resulted in better oxygen delivery and oxygen delivery-to-oxygen demand ratio as an index of oxygen debt
  • NS had better tissue perfusion and oxygen metabolism than LR
  • LR resuscitation returned BE and bicarbonate to pre-hemorrhage levels within 3 h, but no return of BE or bicarbonate was observed for 6 hr with NS resuscitation
  • current blood bank guidelines state that LR should not be mixed with blood to prevent the risk of clot formation from calcium included in LR
  • LR resuscitation should not be given with blood through the same iv-line and crystalloids should be avoided in patients with blood transfusion
  • PT and aPTT were prolonged for 6 h after hemorrhage and resuscitation, suggesting a hypocoagulable states
  • potential thrombotic risk from LR resuscitation is unlikely.
  • we suspected that the blood pressure after NS resuscitation would be lower than that of LR due to its vasodilator effects
  • NS required a larger resuscitation volume and was associated with poor acid base status and elevated serum potassium in this model
  • NS required 50% more volume and was associated with a higher cardiac output and lower peripheral resistance, as compared to LR resuscitation
  • These differences are possibly due to the vasodilator effects from NS
  • an elevation of K+ was observed at 6 h post NS resuscitation, while no change of K+ was observed after LR resuscitation
  • The mechanism for the increase of K+ from NS is not fully known
  • NS is associated with vasodilator effects and the risks of metabolic acidosis and hyperkalemia
  • Nathan Goodyear on 03 Jul 18
     
    LR vs NS crystalloid.
Nathan Goodyear

Clinical review: Specific aspects of acute renal failure in cancer patients - 0 views

www.ncbi.nlm.nih.gov/...PMC1550893

cancer renal failure

shared by Nathan Goodyear on 13 Aug 18 - No Cached
  • uric acid crystal formation in the renal tubules secondary to hyperuricaemia
  • calcium phosphate deposition related to hyperphosphataemia
  • usually develops shortly after the initiation of cytotoxic chemotherapy
  • ...18 more annotations...
  • Non-recombinant urate oxidase (Uricozyme®)
  • recombinant urate oxidase (Rasburicase®)
  • urine alkalisation may induce calcium phosphate deposition
  • renal replacement therapy should be started on an emergency basis when hydration fails to produce a prompt metabolic improvement or when ARF develops
  • Up to 50% of patients with newly diagnosed multiple myeloma have renal failure and up to 10% require dialysis
  • renal ultrasonography remains the method of choice for investigating extra-renal obstruction
  • The relief of the obstruction, either by percutaneous nephrostomy or through a ureteral stent, is the cornerstone of treatment
  • TMA may be associated with the cancer itself, with cancer chemotherapy, or with allogeneic BMT
  • thrombotic microangiopathy (TMA)
  • it may be as high as 5%
  • Most of the cases occur in patients with solid tumours, the most common type being adenocarcinoma (stomach, breast and lung)
  • The pathophysiology of the TMA-malignancy association remains controversial, although many studies suggest an insult to the vascular endothelium
  • mitomycin C. Subsequently, TMA has been reported with many anti-cancer agents, including gemcita-bine, bleomycin, cisplatin, CCNU, cytosine arabinoside, daunorubicin, deoxycoformycin, 5-FU, azathioprine and interferon α
  • Plasma exchanges have been shown to improve prognosis in the general population of patients with TMA
  • Causative factors should be looked for and antihypertensive treatment given. Lastly, in the absence of guidelines, we believe that plasma exchange should be proposed in patients with severe cancer treatment-associated TMA
  • The most widely used protective measure is saline infusion to induce solute diuresis
  • During methotrexate infusion and elimination, fluids should be given to maintain a high urinary output and urinary alkalisation should be performed to keep the urinary pH above 7.5. Rescue with folinic acid (50 mg four times a day) should be started 24 hours after each high-dose metho-trexate infusion and serum methotrexate concentrations should be measured every day
  • cyclophosphamide and ifosfamide
  • Nathan Goodyear on 13 Aug 18
     
    cancer and renal failure
Nathan Goodyear

Multiple Myeloma Tumor Cells are Selectively Killed by Pharmacologically-dosed Ascorbic Acid - EBioMedicine - 0 views

www.ebiomedicine.com/...fulltext

multiple myeloma vitamin C IV vitamin C smoldering myeloma cancer

shared by Nathan Goodyear on 25 Sep 17 - No Cached
  • Recent reports indicate that a certain ROS concentration is required for high-dose vitamin C to induce cytotoxicity in cancer cells.
  • The generation of ascorbyl- and H2O2 radicals by PAA increases ROS stress in cancer cells
  • In this study, we report that PAA is efficacious in killing MM cells in vitro and in vivo models, which generated levels of 20–40 mM ascorbate and 500 nM ascorbyl radicals after intraperitoneal administration of 4 g ascorbate per kilogram of body weight (Chen et al., 2008Chen et al., 2008), in xenograft MM mice
  • ...33 more annotations...
  • These data suggest that PAA may show a therapeutic advantage to blood cancers vs solid tumors because of the communication between tumor cells and blood plasma
  • These results strongly suggest that the mechanism of PAA killing of MM cells is indeed iron-dependent
  • These results suggest that PAA administration in SMM may be able to prevent progression to symtomatic MM
  • A recent study by Yun and colleagues demonstrated that vitamin C selectively kills KRAS and BRAF mutant colorectal cancer cells by targeting GAPDH, but spares normal cells
  • RAS family genes show the most frequent mutations in MM. KRAS, NRAS and BRAF are mutated in 22%, 20% and 7% of MM samples
  • the disease stage rather than the mutation of RAS and/or BRAF is the major predictive factor for PAA sensitivity in MM treatment
  • Other molecular mechanisms including ATP depletion and ATM-AMPK signaling have been reported to explain PAA-induced cell death
  • our pilot study also suggested that PAA could overcome drug resistance to bortezomib in MM cells
  • Our findings complement reported studies and further address the mechanism of action using clinical samples in which we observed that PAA killed tumor cells with high iron content, suggesting that iron might be the initiator of PAA cytotoxicity
  • combination of PAA with standard therapeutic drugs, such as melphalan, may significantly reduce the dose of melphalan needed
  • Combined treatment of reduced dose melphalan with PAA achieved a significantly longer progression-free survival than the same dose of melphalan alone.
  • These data also suggest that the bone marrow suppression induced by high-dose melphalan can be ameliorated by the combination of PAA with lower dose of melphalan because of the lack of toxicity of PAA on normal cells with low iron content.
  • if creatinine clearance is <30 mL/min, high dose ascorbic acid should be not administrated.
  • In MM preclinical and clinical studies, ascorbate was used as an adjunct drug and showed controversial results (Harvey et al., 2009, Perrone et al., 2009, Held et al., 2013, Sharma et al., 2012, Nakano et al., 2011, Takahashi, 2010, Sharma et al., 2009, Qazilbash et al., 2008). However, none of these tests used pharmacological doses of ascorbate and intravenous administration
  • Multiple myeloma (MM) is a plasma cell neoplasm.
  • Cameron and Pauling reported that high doses of vitamin C increased survival of patients with cancer
  • pharmacologically dosed ascorbic acid (PAA) 50–100 g (Chen et al., 2008, Padayatty et al., 2004, Hoffer et al., 2008, Padayatty et al., 2006, Welsh et al., 2013), administered intravenously, has potent anti-cancer activity and its role as anti-cancer therapy is being studied at the University of Iowa and in other centers
  • In the presence of catalytic metal ions like iron, PAA administered intravenously exerts pro-oxidant effects leading to the formation of highly reactive oxygen species (ROS), resulting in cell death
  • the labile iron pool (LIP) is significantly elevated in MM cells
  • The survival of CD138+ cells in vitro was significantly decreased following PAA treatment in all 9 MM
  • In contrast, no significant change of cell viability was observed in CD138− BM cells from the same patients
  • The same effect of PAA was also observed in the SMM patients
  • no response to PAA was detected in CD138+ cells from the 2 MGUS patients
  • the combination of melphalan plus PAA showed greater tumor burden reduction than each drug alone, suggesting a synergistic activity between these two drugs
  • Both catalase and NAC protect cells from oxidative damage
  • cells pretreated with NAC and catalase became resistant to PAA even at high doses
  • adding deferoxamine (DFO), an iron chelator, to OCI-MY5 cells before PAA treatment was also sufficient to prevent PAA-induced cellular death
  • iron is essential for PAA to achieve its anti-cancer activity
  • PAA induced early necrosis (Fig. 3Fig. 3A, 60 min) followed by late apoptosis
  • results further indicated that PAA induced mitochondria-mediated apoptosis
  • PAA by reacting with LIP and generating ROS induces mitochondria-mediated apoptosis in which AIF1 cleavage is important for cell death.
  • ROS and H2O2 are well known factors mediating PAA-induced cancer cell death
  • PAA was sensitive to all 9 MMs and 2 SMMs
  • Nathan Goodyear on 25 Sep 17
     
    animal study finds high-dose, pharmacologic vitamin C found to kill multiple myeloma cells via pro-oxidant effect found in similar studies in dealing with different cancers.
‹ Previous 21 - 40 of 69 Next › Last »
Showing 20▼ items per page