Skip to main content

Home/ Dr. Goodyear/ Group items tagged prolonged

Rss Feed Group items tagged

Filter: All | Bookmarks | Topics Simple Middle
26More

Exercise-induced right ventricular dysfunction and structural remodelling in endurance ... - 0 views

eurheartj.oxfordjournals.org/...998 endurance athletes training heart health injury
shared by Nathan Goodyear on 09 Jan 15 - No Cached
  • In a cohort of well-trained athletes, we demonstrated that intense endurance exercise causes an acute reduction in RV function that increases with race duration and correlates with increases in biomarkers of myocardial injury
  • no relationship between LV function and biomarker levels
  • focal gadolinium enhancement and increased RV remodelling were more prevalent in those athletes with a longer history of competitive sport, suggesting that repetitive ultra-endurance exercise may lead to more extensive RV change and possible myocardial fibrosis
  • ...22 more annotations...
  • he cardiac impact of both acute and cumulative exercise is greatest on the RV.
  • Greater reductions in RV function occurred in those athletes competing for a longer duration, suggesting that the heart has a finite capacity to maintain the increased work demands of exercise
  • cardiac injury is greatest in the least trained
  • Previous investigators have documented reductions in RV function in less trained subjects over the marathon distance
  • We enrolled elite and subelite athletes and found a significant association between fitness (VO2max) and the reduction in post-race RVEF
  • Even after many years of detraining, cardiac dilation may not completely regress in elite athletes
  • The focus on well-trained athletes may be of particular relevance, given that they perform exercise of highest intensity and duration most frequently, and, thus, may be at a greater risk of cumulative injury.
  • The lack of correlation between increases in troponin and changes in LV function seen in this study has been previously interpreted as evidence that post-exercise elevations in cardiac biomarkers are benign.
  • a significant correlation between changes in RVEF and post-race biomarker levels and this relationship was even stronger in the athletes who completed the race of longest duration, the ultra-triathlon
  • The correlations with RVEF, but not LVEF, provide further evidence of the differential effects of intense exercise on RV and LV function
  • BNP release during intense exercise is associated with greater relative increases in RV systolic pressures, but not LV pressures
  • BNP may provide a measure of both acute RV load and the resultant fatigue which occurs when this load is sustained
  • It has been demonstrated that ventricular load increases with exercise intensity and is greater for the RV than the LV,29 thus potentially explaining why the RV is more susceptible to fatigue after prolonged exercise.
  • This study demonstrates, for the first time, an association between endurance exercise of increasing duration and structural, functional, and biochemical markers of cardiac dysfunction in highly trained athletes
  • Functional abnormalities were confined to the RV and were largely reversible 1 week following the event
  • there remained a significant minority of athletes in whom there was evidence of myocardial fibrosis in the interventricular septum
  • RV abnormalities may be acquired through cumulative bouts of intense exercise and provides direction for prospective investigations aimed at elucidating whether extreme exercise may promote arrhythmias in some athletes.
  • the acute injury and chronic remodelling of the myocardium both disproportionately affect the RV and it remains possible that the two are linked.
  • focal DGE was confined to the interventricular septum and commonly at the site of RV attachment
  • emerging evidence that intense endurance exercise may be associated with an excess in arrhythmic disorders, the mechanisms for which remain unexplained
  • RVEF (and not LVEF) was reduced in athletes with complex ventricular arrhythmias when compared with healthy athletes and non-athletes without arrhythmias
  • it is premature to conclude that these changes may represent a proarrhythmic substrate
  • Nathan Goodyear on 09 Jan 15
     
    Study finds endurance racing results in reduce Right ventricle ejection fraction even in elite athletes.  This post-race RVEF reduction is associated with VO2max.
1More

PLOS ONE: The Ketogenic Diet and Hyperbaric Oxygen Therapy Prolong Survival in Mice wit... - 0 views

www.plosone.org/...10.1371%2Fjournal.pone.0065522 hyperbaric therapy hyperbaric ketogenic diet ketogenic cancer
shared by Nathan Goodyear on 12 Nov 14 - No Cached
  • Nathan Goodyear on 12 Nov 14
     
    Hyperbaric therapy improved glucose, tumor growth rate, and increased survival time of mice from 56.7% to 77.9%.
1More

Short-term recovery from prolonged exercise: exploring the potential for protein ingest... - 0 views

opus.bath.ac.uk/21471 training exercise exercise recovery recovery athlete athletes carbohydrates protein
shared by Nathan Goodyear on 10 Feb 16 - No Cached
  • Nathan Goodyear on 10 Feb 16
     
    only abstract available here. early high glycemic carbs benefit fast glycogen restoration.  Adding protein at 0.3 g/kg aids glycogen restoration.
1More

Knee Cap Open Patella - 0 views

www.wheelchairindia.com/...Tynor-Knee-Cap-Open-Patella Knee Cap Allows Easy Movement and Improves Comfort Tynor Knee Cap Comfeel Use Knee Cap open patella reduces pressure on patella associated with old age Freely breathable Soft and comfortable
shared by wheelchairindia9 on 14 Mar 16 - No Cached
  • wheelchairindia9 on 14 Mar 16
     
    Tynor Knee Cap Open Patella Knee Cap open patella is a compression tubular support used in orthopaedic practice to provide firm compression warmth & support to the limbs and joints, to allay pain and inflammation, generally associated with old age, arthritis, sports injury etc. Silicon patellar insert Four way stretch Freely breathable Soft and comfortable Tynor Knee Cap Open Patella Features Made from high quality nylon Ensures longer life. Appealing aesthetics Offers color fastness. Four-way stretch ability Good grip and compression Snug fitting No bunching at the back. Better comfort.. Special interlocking weave and single spiral elastic yarn , double layered Uniform compression even on uneven limb surface. Warmth improves healing. Provides firm support and gentle compression. Anterior patellar opening Relieves patellar pressure. Positions patella in patellar dislocations. Silicon patellar padding Propioception. Massages, increases blood flow, quick healing. Compresses and supports patellar tendon.
1More

Tynor Walker Boot - 0 views

www.wheelchairindia.com/...Tynor-Walker-Boot Tynor Walker Boot Walker Boot Walker Boots Tynor Walker Tynor Walkers tynor walking boot walker boot tynor
shared by wheelchairindia9 on 22 Mar 16 - No Cached
  • wheelchairindia9 on 22 Mar 16
     
    Tynor Walker Boot is designed by the Tynor to rehabilitate the person after injury or fracture. It allows easy movement as well as supports the ankle and leg. This can be a great substitute for cast and also useful during early cast removal. It can also be used during sprain in the foot and this walker gives great relief to the pain. It can easily do any mild activity. It also works for the persons with a lower leg and will give an equal level of the lower feet as well as reduces the pressure. It effectively enclosed the muscles of the leg or foot during the fracture and gives comfort without disturbing the recovery process. This walker boot is made up from the good quality material. It has Aluminum lateral bars that are corrosion free. It is light in weight and provides enhanced mobility. It gives sturdy support to feet and leg. Its Hook Loop system allows to adjust it according to the comfort. It is also infused with Foam liner and Pad set that gives soft feet and also provides great support. It is available in different sizes. Tynor Walker Boot Tynor Walker Boot is designed for rehabilitation after injury, fracture , sprains or surgery of foot, ankle or lower leg. The boots provide support to the ankle and leg without inhibiting mobility. They can be a substitute for cast or can be used in case of early cast removal. With a wider rocker bottom, these boots promote a natural gait, reduced plantar pressure, enhanced stability and comfort to the lower leg. Light weight. Sturdy Support. Enhanced mobility. Maintains normal gait. Tynor Walker Boot Features Moulded foot Improves gait Rocker sole-helps in easy ambulation Offers stabilization of the foot ankle and the lower leg Comfortable positioning and protection of the foot Aluminum lateral bars Rigid support-Improved immobilization of the ankle and the lower leg Malleable, shape can be customized for better fitting and support Foam liner and Pad set Ensure extreme comfort Ensure per
1More

PF Night Splint Derotation - 0 views

www.wheelchairindia.com/...PF-Night-Splint-Derotation Understanding The Role Of Treating Night Splints plantar fascia and intrinsic musculature Derotation foot splinting provides support to the knee multiple orthopedic problems Less slippage of product
shared by wheelchairindia9 on 21 Mar 16 - No Cached
  • wheelchairindia9 on 21 Mar 16
     
    PF Night Splint (Derotation) Applications Prevention and correction of foot drop. Night splint for early healing. Ambulatory, can be used as a day splint. Perfect post-operative immobilisation and derotation. Peroneal / Peritibial nerve or muscle damage. Ankle or Plantar flexion contracture and functional alignment. Can be used to protect the diabetic/ injured ankle & foot. PF Night Splint (Derotation) Features Removable de-rotation bar. Moulded foot casing, aesthetically pleasing and durable. Effective Liner, improved comfort. Highly functional Design, customized degree of dorsiflexion. Double strapping mechanism, better grip.
4More

Nutrients | Free Full-Text | Myths, Artifacts, and Fatal Flaws: Identifying Limitations... - 0 views

www.mdpi.com/...htm vitamin C ascorbic acid
shared by Nathan Goodyear on 24 Sep 18 - No Cached
  • l-gulonolactone oxidase, an enzyme with the synthesis of l-ascorbic acid as its only known function
  • prolonged fasting causes ascorbate synthesis to decline
  • agents that stimulate glycogenolysis also stimulate ascorbate synthesis when an animal is in a fed state
  • Nathan Goodyear on 24 Sep 18
     
    Great review on the science of vitamin C.
16More

The Pharmacokinetics and Interactions of Ivermectin in Humans-A Mini-review - 0 views

www.ncbi.nlm.nih.gov/...PMC2751445 Ivermectin
shared by Nathan Goodyear on 19 Mar 18 - No Cached
  • This drug is extensively metabolized by human liver microsomes by cytochrome P450
  • cytochrome P-4503A4, converting the drug to at least 10 metabolites
  • its elimination half-life is around a day
  • ...12 more annotations...
  • second rise in plasma levels (mostly occurring between 6 and 12 h after the dose) suggesting an enterohepatic recycling of the drug
  • Ivermectin is exceptionally potent, with effective dosages levels that are unusually low.
  • the optimal dose of ivermectin is 150 μg/kg, but the frequency of administration is still controversial, ranging from 150 μg/kg once to three times yearly.
  • high lipid solubility of ivermectin, this compound is widely distributed within the body.
  • To interrupt the transmission of onchocerciasis in humans, the combination of ivermectin and doxycycline is highly effective as, in infested patients, the ingestion of the anthelmintic (200 μg/kg, single dose) and the antibacterial (100 mg/kg, daily for 6 weeks)
  • ivermectin interactions with another concurrently administered drugs can occur.
  • This issue becames important, as combination chemotherapy is being used with increasing frequency as resistance to antiparasitic agents is becoming more widespread.
  • haematomatous swellings
  • prothrombin times were significantly above baseline by one week to one month after drug ingestion, suggesting an antagonist effect against vitamin K
  • bleeding disorders were not found in 15,000 patients treated with ivermectin (150 μg/kg)
  • prolonged prothrombin ratios were observed in 148 subjects given ivermectin orally. Although no patients suffered bleeding complications, factor II and VII levels were reduced in most of them, suggesting interference with vitamin K metabolism
  • Ivermectin has a minimal effect on coagulation and concern about mass treatment for this reason appears to be unjustified
  • Nathan Goodyear on 19 Mar 18
     
    Review of Ivermectin as an anti-parasitic.
18More

American Journal of Obstetrics & Gynecology Home Page - 0 views

www.ajog.org/...fulltext "Vaginal mesh" immune system
shared by Nathan Goodyear on 31 Aug 18 - No Cached
  • M1 macrophages are characterized by the secretion of reactive oxygen species and proinflammatory cytokines and chemokines and can be identified via the cell surface marker CD86
  • M2 macrophages secrete growth factors and antiinflammatory immune modulators and can be identified by the cell surface marker CD206
  • an overzealous M2 response can also lead to excess tissue deposition and fibrosis
  • ...14 more annotations...
  • Studies of similar meshes that are used in hernia repair have demonstrated that all polypropylene meshes induce a prolonged inflammatory response at the site of implantation
  • the long-term presence of activated inflammatory cells, such as macrophages at the mesh tissue interface, can impact negatively the ability of the mesh to function as intended.
  • All M1 proinflammatory and M2 proremodeling cytokines and chemokines were increased in mesh explants as compared with nonmesh tissue (Table 3Table 3), which indicated a robust, active, and ongoing host response to polypropylene long after implantation
  • Comparison of the ratio of the M2 proremodeling cytokines (IL-10+IL-4) with the M1 proinflammatory cytokines (TNF-α+IL-12p70) revealed a decrease in mesh explants as compared with controls (P = .003), which indicated a shift towards a proinflammatory profile.
  • Mesh explants contained a higher number of total cells/×200 field when compared with controls (682.46 ± 142.61 cells vs 441.63 ± 126.13 cells; P < .001) and a lower ratio of M2:M1 macrophages (0.260 ± 0.161 cells vs 1.772 ± 1.919; P = .001), which supported an ongoing proinflammatory response.
  • the host response was proportional to the amount of material in contact with the host
  • A persistent foreign body response was observed in mesh-tissue complexes that were excised from women who required surgical excision of mesh months to years after mesh implantation
  • The host response was characterized by a predominance of macrophages with an increase in both proinflammatory and proremodeling cytokines/chemokines along with increased tissue degradation, as evidenced by increased MMP-2 and -9
  • Mesh-tissue complexes removed for mesh exposure had increased pro–MMP-9 that indicated a proinflammatory and tissue destruction–type response
  • The presence of macrophages, elevated cytokines, chemokines, and MMPs in tissue-mesh complexes that were excised from patients with exposure or pain suggests that polypropylene mesh elicits an ongoing host inflammatory response
  • In the presence of a permanent foreign body, the implant is surrounded with a fibrotic capsule because it cannot be degraded
  • For hernia meshes, if the fibers are too close (<1 mm), the fibrotic response to neighboring fibers overlaps, or “bridges,” and results in “bridging fibrosis” or encapsulation of the mesh
  • Gynemesh PS has a highly unstable geometry when loaded that resulted in pore collapse and increasing stiffness of the product
  • mesh shrinkage (50-70%) has been described to occur after transvaginal insertion of prolapse meshes
  • Nathan Goodyear on 31 Aug 18
     
    Mesh and the abnormal immune response.
17More

Anti-helminth compound niclosamide downregulates Wnt Signaling and elicits antitumor re... - 0 views

www.ncbi.nlm.nih.gov/...PMC3117125 Niclosamide Wnt cancer colon cancer
shared by Nathan Goodyear on 21 Mar 18 - No Cached
  • Others have reported that niclosamide inhibits the NF-κB pathway in leukemia cell lines (26) or mTOR signaling in MCF-7 breast cancer cells
  • niclosamide enhances the anti-tumor effect of oxaliplatin
  • In the more rapidly growing tumor (HCT116), a dose of 200 mg/kg of body weight was needed to suppress the tumor growth
  • ...13 more annotations...
  • however, 100 mg/kg of niclosamide could suppress the growth of the relatively slow-growing tumor (CRC039) to the same level
  • niclosamide was confirmed to inhibit the growth of human CRCs in NOD/SCID mice
  • niclosamide can inhibit Wnt pathway activation in CRC
  • The mechanism of action of the niclosamide in our studies is thought to be through internalization of Fzd1 and downregulation of Wnt pathway intermediaries
  • Recently, Jin et al. (26) reported that niclosamide inhibited the NF-κB pathway and increased reactive oxygen species levels to induce apoptosis in AML cells. In contrast, we did not observe any inhibitory effect of niclosamide on NF-κB signaling in our CRC model
  • oral administration of niclosamide does result in sufficient distribution of the drug into tumor tissue, to prove a prolonged inhibitory effect on Wnt/ß-catenin signaling, resulting in tumor growth inhibition
  • we required higher doses (100 ~ 200 mg/kg body weight) of niclosamide in order to demonstrate significant inhibition of tumor growth in NOD/SCID mice
  • niclosamide concentrations in tumor tissue showed good correlation with those in plasma, suggesting the efficient distribution of niclosamide from blood to tumor tissue
  • we observed downregulation of Dvl2 and ß-catenin cytosolic expression in niclosamide-treated tumor cells in vivo
  • One potential concern for the use of niclosamide as an anticancer therapy is the poor absorption of this drug
  • The Wnt signaling pathway, fundamental to embryonic tissue patterning, is also activated in stem-like cells
  • The canonical Wnt pathway is activated in approximately 80% of sporadic CRC primarily due to mutations in the APC gene
  • recent observations reveal that Wnt ligands or inhibitors may affect the growth and survival of colon cancer cells in spite of the presence of APC or CTNNB1 mutations
  • Nathan Goodyear on 21 Mar 18
     
    Niclosamide found to inhibit Wnt/B-catenin signaling pathway, and thus promotion of apoptosis, in colorectal cancer cells in Vivo study.  It was also found to augment chemotherapeutic.
17More

Cortisol Exerts Bi-Phasic Regulation of Inflammation in Humans - 0 views

www.ncbi.nlm.nih.gov/...PMC3186928 cortisol glucocorticoids inflammation hormones
shared by Nathan Goodyear on 12 Oct 16 - No Cached
  • GCs induce increased cellular expression of receptors for several pro-inflammatory cytokines including interleukin (IL)-1 (Spriggs et al. 1990), IL-2 (Wiegers et al. 1995), IL-4 (Paterson et al. 1994), IL-6 (Snyers et al. 1990), and IFN-g (Strickland et al. 1986), as well as GM-CSF
  • GCs have also been shown to stimulate effector cell functions including phagocytosis by monocytes (van der Goes et al. 2000), effector cell proliferative responses (Spriggs et al. 1990), macrophage activation (Sorrells and Sapolsky 2010), and a delay of neutrophil apoptosis
  • a concentration- and time-dependent range of GC effects that are both pro- and anti-inflammatory
  • ...13 more annotations...
  • basal (diurnal) concentrations of cortisol do not exert an anti-inflammatory effect on several pro-and anti-inflammatory mediators of the human immune inflammatory response
  • withdrawal of cortisol activity in vivo did not lead to increased inflammatory responsiveness of immune effector cells
  • maximal suppression of inflammation was achieved by a stress-associated, but still physiologic, cortisol concentration. There was no greater anti-inflammatory effect at higher cortisol concentrations (Yeager et al. 2005) although IL-10 concentrations continued to increase with increasing cortisol concentrations as we and others have shown
  • acutely, physiological cortisol concentrations are anti-inflammatory and, as proposed, act to limit over expression of an inflammatory response that could lead to tissue damage
  • Acutely, cortisol has anti-inflammatory effects following a systemic inflammatory stimulus (Figure 4). However, a cortisol concentration that acts acutely to suppress systemic inflammation also has a delayed effect of augmenting the inflammatory response to subsequent, delayed stimulu
  • 1) GCs can exert pro-inflammatory effects on key inflammatory processes and, 2) GC regulation of inflammation can vary from anti- to a pro-inflammatory in a time-dependent manner
  • The immediate in vivo effect of both stress-induced and pharmacological GC concentrations is to suppress concurrent inflammation and protect the organism from an excessive or prolonged inflammatory response
  • GCs alone, in the absence of an inflammatory stimulus, up-regulate monocyte mRNA and/or receptors for several molecules that participate in pro-inflammatory signaling, as noted above and in the studies presented here.
  • In humans, as shown here, if in vivo GC concentrations are elevated concurrent with an inflammatory stimulus, anti-inflammatory effects are observed
  • In sharp contrast, with a time delay of 12 or more hours between an increased GC concentration and the onset of an inflammatory stimulus, enhancing effects on inflammation are observed. These effects have been shown to persist in humans for up to 6 days
  • GC-induced enhancement of inflammatory responses is maximal at an intermediate concentration, in our studies at a concentration that approximates that observed in vivo following a major systemic inflammatory stimulus
  • In addition to enhanced responses to LPS, recently identified pro-inflammatory effects of GCs also show enhanced localization of effector cells at inflammatory sites
  • we hypothesize that pre-exposure to stress-associated cortisol concentrations “prime” effector cells of the monocyte/macrophage lineage for an augmented pro-inflammatory response by; a) inducing preparative changes in key regulators of LPS signal transduction, and b) enhancing localization of inflammatory effector cells at potential sites of injury
  • Nathan Goodyear on 12 Oct 16
     
    very interesting read on the effects of inflammation on cortisol and visa versa.
21More

Nutrients | Free Full-Text | Vitamin C Status Correlates with Markers of Metabolic and ... - 0 views

www.mdpi.com/...htm vitamin C health cognition
shared by Nathan Goodyear on 28 Feb 18 - No Cached
  • vitamin C deficiency is the fourth most prevalent nutrient deficiency reported in the United States
  • Hypovitaminosis C (defined as a plasma concentration ≤23 µmol/L)
  • The CHALICE (Canterbury Health, Ageing and Lifecourse) study is a unique New Zealand study comprising a comprehensive database of determinants of health
  • ...17 more annotations...
  • The CHALICE cohort of 404 individuals aged 50 years had an average vitamin C intake of ~110 mg/day, which should provide adequate plasma concentrations [14]. Despite this, a significant proportion of the participants had inadequate plasma vitamin C status
  • inadequate plasma vitamin C concentrations (i.e., <50 µmol/L)
  • adequate plasma levels (i.e., >50 µmol/L)
  • Higher plasma vitamin C status was associated with lower weight, BMI and waist circumference
  • plasma vitamin C was negatively associated with blood triglycerides, HbA1c and insulin, and positively associated with HDL levels.
  • No correlation was found between plasma vitamin C and the two indicators of heart health; blood pressure and cardiovascular risk score.
  • 2.4% of 50-year-olds were deficient in vitamin C (i.e., <11 µmol/L)
  • hypovitaminosis C (i.e., <23 µmol/L)
  • A high proportion (63%) of our participants had inadequate plasma vitamin C concentrations (i.e., <50 µmol/L)
  • The association of low vitamin C with obesity in this study replicates results in the literature [35,40,41,42,43,44], and it is apparent that individuals with higher weight require higher intakes of vitamin C to reach adequate vitamin C status
  • higher plasma vitamin C status is associated with lower circulating levels of blood triglycerides, insulin and HbA1c
  • A role for vitamin C in the prevention or management of diabetes and/or metabolic syndrome has been suggested
  • In this study, we also demonstrate lower levels of mild cognitive impairment in those with high vitamin C status
  • The odds of mild cognitive impairment were twice as high for those below 23 μmol/L plasma vitamin C concentration.
  • Vitamin C is present at very high concentrations in the brain
  • animal models have shown that the brain is the last organ to be depleted of the vitamin during prolonged deficiency
  • A recent animal study has shown that moderate vitamin C deficiency may play a role in accelerating amyloid plaque accumulation in Alzheimer’s disease
  • Nathan Goodyear on 28 Feb 18
     
    New study: vitamin C levels correlate with cognitive and metabolic health. What is your vitamin C level? Despite the adequate levels of vitamin C intake, a large % of the individuals had inadequate vitamin C levels which points to a demand issue.  Higher oxidative stress, chronic inflammation... would drive demand for vitamin C higher. Lower vitamin C levels were associated with more metabolic disease, ie. DM, and more cognitive decline.
40More

Intravenous Ascorbate as a Tumor Cytotoxic Chemotherapeutic Agent - 0 views

www.seanet.com/...d_hypotheses_1995-v44-p207.htm vitamin C cancer IV vitamin C ascorbic acid
shared by Nathan Goodyear on 05 Mar 18 - No Cached
  • 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
  • ...36 more annotations...
  • 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.
  • Nathan Goodyear on 05 Mar 18
     
    Older study, 1995, but shows the long-standing evidence that IVC preferentially is cytotoxic to cancer cells.`
50More

Vitamin C preferentially kills cancer stem cells in hepatocellular carcinoma via SVCT-2... - 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.
1More

Supplemental ascorbate in the supportive treatment of cancer: Reevaluation of prolongat... - 0 views

www.ncbi.nlm.nih.gov/...PMC336151 vitamin C IV vitamin C Fe cancer ferritin
shared by Nathan Goodyear on 08 Jul 19 - No Cached
  • Nathan Goodyear on 08 Jul 19
     
    This is the republication of the original Pauling and Cameron study. This re-analysis actually revealed better outcomes than the original. Also, they found that vitamin C likely is responsible for the release of Fe from ferritin required for the cytotoxicity with vitamin C.
1More

Prolonged stabilization of platinum-refractory ovarian cance... : Medicine - 0 views

journals.lww.com/...articleviewer.aspx ascites Intra-peritoneal mistletoe ovarian cancer cancer
shared by Nathan Goodyear on 07 Apr 21 - No Cached
  • Nathan Goodyear on 07 Apr 21
     
    Mistletoe injected intraperitoneal 3 x weekly to reduce ascites.
1More

Topoisomerase I inhibitors: the relevance of prolonged exposure for present clinical de... - 0 views

www.nature.com/...bjc1997491 cancer metronomic chemotherapy low-dose chemotherapy
shared by Nathan Goodyear on 09 Nov 20 - No Cached
  • Nathan Goodyear on 09 Nov 20
     
    Metronomic dosing out performs maximum tolerated chemotherapy in in vitro study.
1More

Les meilleurs hôpitaux cardiaques de Delhi prolongent la vie des patients sou... - 0 views

french-health-trip-2-india.blogspot.com/...-heart-hospitals-of-delhi.html Chirurgie cardiaque Inde Meilleurs hôpitaux cardiaques de Delhi Coût de la chirurgie cardiaque en Inde Chirurgie cardiaque à faible coût Inde Chirurgie cardiaque abordable en Inde Meilleur prix pour la chirurgie cardiaque en Inde Meilleurs hôpitaux de chi
shared by indian-health on 21 Oct 21 - No Cached
  • indian-health on 21 Oct 21
     
    La valeur cardiaque minimalement invasive est très bon marché en Inde, le pays possède les meilleurs hôpitaux cardiaques de Delhi offrant des installations de classe mondiale, et ils disposent d'infrastructures de qualité. Lire la suite https://bit.ly/3B1dYr4 Appelez-nous +91-9371136499 Écrivez-nous contact@indianhealthguru.com #Top10descardiologuesàDelhi #MeilleurcardiologueàDelhi #MeilleurchirurgiencardiaqueàDelhi #MeilleurchirurgiendepontageàDelhi #ChirurgiecardiaqueInde #MeilleurshôpitauxcardiaquesàDelhi
« First ‹ Previous 61 - 80 of 81 Next ›
Showing 20▼ items per page