Skip to main content

Home/ Dr. Goodyear/ Group items tagged stone

Rss Feed Group items tagged

Filter: All | Bookmarks | Topics Simple Middle
Nathan Goodyear

Urolithiasis is associated with low serum testosterone levels in men | Otunctemur | Arc... - 0 views

www.pagepressjournals.org/...4580

urolithiasis kidney stones low T low Testosterone men male hormone hormones metabolic syndrome

shared by Nathan Goodyear on 13 Apr 15 - No Cached
  • Nathan Goodyear on 13 Apr 15
     
    low Testosterone is associated with kidney stones in men through increased Metabolic Syndrome.  Better stated, low T is associated with metabolic syndrome and this metabolic dysfunction increased the findings of kidney stones in men.
Nathan Goodyear

No Reported Renal Stones with Intravenous Vitamin C Administration: A Prospective Case ... - 0 views

www.ncbi.nlm.nih.gov/...PMC5981254

vitamin C kidney stones IV vitamin C

shared by Nathan Goodyear on 13 May 20 - No Cached
  • Nathan Goodyear on 13 May 20
     
    Review finds no real increase in kidney stone risk.
Nathan Goodyear

Vitamin C-Induced Oxalate Nephropathy - 0 views

www.hindawi.com/...146927

vitamin C nephropathy kidney stones

shared by Nathan Goodyear on 09 Apr 20 - No Cached
  • Nathan Goodyear on 09 Apr 20
     
    Case study of vitamin C causing oxaloacetate kidney stones and resultant nephropathy.
wheelchairindia9

Easy Handicap Life By Heavy Duty Wheelchair - 0 views

www.blogroll.net/article.php

Easy Handicap Life By Heavy Duty Wheelchair types of medical wheelchairs folding frame adjustable backrest adjustable rear wheel position Axle Plate Adjustments Double cross-brace

shared by wheelchairindia9 on 24 Apr 15 - No Cached
  • wheelchairindia9 on 24 Apr 15
     
    Mobility is an important part of human life. When an affordable wheelchair becomes necessary, for whatever reason, the circumstances are often not ideal. Purchasing an affordable wheelchair starts with knowing the patient and researching the types of wheelchairs available. It is a great resource on many different types of medical wheelchairs. Bariatric wheelchair, designed for users between 18 and 26 stone. It has a padded sling and backrest to ensure the comfort of the user, and the armrests can be removed to allow easy transfer into and out of the wheelchair. The Heavy User Wheelchair is self-propelled, giving the option to either push it, or have the user move themselves. The large rear wheels make the wheelchair well-suited to outdoor use, and allow the user to change the direction they face when in social situations. It has folding frame, so it is easy for storage and transport. Interchangeable frame components allow to grow and change the chairs width and depth. There are custom frame specifications available. Maximum option choices allow chair to be built to the individual's specifications. It has folding "lockout" cross-brace. Cross-brace locks to limit flex in the frame for more efficient propelling. Double cross-brace. Allows more strength and enables greater weight capacity. Wheelchair Bariatric has Adjustable back height. Ensures optimal positioning of backrest for stability and scapular movement. Stabilizer bar to minimize flex and provides a more efficient ride. Multiple footplate options ensure optimal positioning of lower extremities. Quick-release axle allows quick removal of rear wheels for easy transport. Adjustable Axle Plate Adjustments help to maximize stability and propulsion of the chair. Allows center of gravity adjustment for more efficient ride. Also makes it possible to adjust the rear frame height when it's necessary to change the caster wheels. Description: Attendant cable brake. 14" rear wheels. Detachable and washable cu
wheelchairindia9

Easy Handicap Life By Heavy Duty Wheelchair - 0 views

www.apsense.com/...-by-heavy-duty-wheelchair.html

Easy Handicap Life By Heavy Duty Wheelchair types of medical wheelchairs folding frame adjustable backrest adjustable rear wheel position Axle Plate Adjustments Double cross-brace

shared by wheelchairindia9 on 19 Apr 15 - No Cached
  • wheelchairindia9 on 19 Apr 15
     
    Mobility is an important part of human life. When an affordable wheelchair becomes necessary, for whatever reason, the circumstances are often not ideal. Purchasing an affordable wheelchair starts with knowing the patient and researching the types of wheelchairs available. It is a great resource on many different types of medical wheelchairs. Bariatric wheelchair, designed for users between 18 and 26 stone. It has a padded sling and backrest to ensure the comfort of the user, and the armrests can be removed to allow easy transfer into and out of the wheelchair. The Heavy User Wheelchair is self-propelled, giving the option to either push it, or have the user move themselves. The large rear wheels make the wheelchair well-suited to outdoor use, and allow the user to change the direction they face when in social situations. It has folding frame, so it is easy for storage and transport. Interchangeable frame components allow to grow and change the chairs width and depth. There are custom frame specifications available. Maximum option choices allow chair to be built to the individual's specifications. It has folding "lockout" cross-brace. Cross-brace locks to limit flex in the frame for more efficient propelling. Double cross-brace. Allows more strength and enables greater weight capacity. Wheelchair Bariatric has Adjustable back height. Ensures optimal positioning of backrest for stability and scapular movement. Stabilizer bar to minimize flex and provides a more efficient ride. Multiple footplate options ensure optimal positioning of lower extremities. Quick-release axle allows quick removal of rear wheels for easy transport. Adjustable Axle Plate Adjustments help to maximize stability and propulsion of the chair. Allows center of gravity adjustment for more efficient ride. Also makes it possible to adjust the rear frame height when it's necessary to change the caster wheels. Description: Attendant cable brake. 14" rear wheels. Detachable and washable cu
wheelchairindia9

Easy Handicap Life By Heavy Duty Wheelchair - 0 views

www.articlepoint.org/...-by-heavy-duty-wheelchair.aspx

Easy Handicap Life By Heavy Duty Wheelchair types of medical wheelchairs folding frame adjustable backrest adjustable rear wheel position Axle Plate Adjustments Double cross-brace

shared by wheelchairindia9 on 19 Apr 15 - No Cached
  • wheelchairindia9 on 19 Apr 15
     
    Mobility is an important part of human life. When an affordable wheelchair becomes necessary, for whatever reason, the circumstances are often not ideal. Purchasing an affordable wheelchair starts with knowing the patient and researching the types of wheelchairs available. It is a great resource on many different types of medical wheelchairs. Bariatric wheelchair, designed for users between 18 and 26 stone. It has a padded sling and backrest to ensure the comfort of the user, and the armrests can be removed to allow easy transfer into and out of the wheelchair. The Heavy User Wheelchair is self-propelled, giving the option to either push it, or have the user move themselves. The large rear wheels make the wheelchair well-suited to outdoor use, and allow the user to change the direction they face when in social situations. It has folding frame, so it is easy for storage and transport. Interchangeable frame components allow to grow and change the chairs width and depth. There are custom frame specifications available. Maximum option choices allow chair to be built to the individual's specifications. It has folding "lockout" cross-brace. Cross-brace locks to limit flex in the frame for more efficient propelling. Double cross-brace. Allows more strength and enables greater weight capacity. Wheelchair Bariatric has Adjustable back height. Ensures optimal positioning of backrest for stability and scapular movement. Stabilizer bar to minimize flex and provides a more efficient ride. Multiple footplate options ensure optimal positioning of lower extremities. Quick-release axle allows quick removal of rear wheels for easy transport. Adjustable Axle Plate Adjustments help to maximize stability and propulsion of the chair. Allows center of gravity adjustment for more efficient ride. Also makes it possible to adjust the rear frame height when it's necessary to change the caster wheels. Description: Attendant cable brake. 14" rear wheels. Detachable and washable cu
fnfdoc

Health Issues Due To Blood In Semen | Your Health Our Priority - 0 views

www.fnfdoc.com/...h-issues-due-to-blood-in-semen

Blood In Semen Diseases Health Hematospermia

shared by fnfdoc on 29 Apr 18 - No Cached
  • fnfdoc on 29 Apr 18
     
    Bleeding in semen caused by medical procedures, also known as hematospermia. Blood in semen caused by infections, tumors, and stones in organs as well as anatomical problems. The most common cause is a prostate biopsy.
Nathan Goodyear

High-Dose Intravenous Vitamin C Combined with Cytotoxic Chemotherapy in Patients with A... - 0 views

www.ncbi.nlm.nih.gov/...PMC4388666

IVC "IV vitamin C" "vitamin cancer

shared by Nathan Goodyear on 01 Jun 19 - No Cached
  • Nathan Goodyear on 01 Jun 19
     
    Phase I/II study of IVC with chemotherapy found good safety and tolerability, no oxaloacetate stones and suprisingly, three patients with different types of cancer that experienced unexpected transient stable disease, increased energy and functional improvement...Really?!
Nathan Goodyear

Neoadjuvant chemotherapy induces breast cancer metastasis through a TMEM-mediated mecha... - 0 views

stm.sciencemag.org/...eaan0026

chemotherapy TMEM tumor microenvironment of metastasis metastasis cancer

shared by Nathan Goodyear on 11 Jul 17 - No Cached
  • We found about a twofold increase in circulating tumor cells (CTCs) (P < 0.05) after paclitaxel treatment in all experimental models examined
  • We found an increase in both the metastatic incidence (at least one micrometastatic focus of more than five tumor cells) (Fig. 3I) and the number of cancer cell micrometastases in the lungs of paclitaxel-treated mice
  • in early-stage breast cancers, chemotherapy increases vascular permeability at TMEM sites, which is accompanied by increased cancer cell dissemination.
  • ...1 more annotation...
  • significant ~1.3-fold (P = 0.027) increase in the number of CTCs
  • Nathan Goodyear on 11 Jul 17
     
    New study suggests chemotherapy may increase metastasis  via increase in TMEM.  I wonder if this increases recurrence as well.  Could the very corner stone of Cancer therapy actually increase metastatic risk potential?
indian-health

Top Urethroplasty Surgeons in India Best Care to Improve Your Urology Issues - 0 views

www.101pressrelease.com/to-improve-your-urology-issues

best Urethroplasty surgeons best urologist in india Urethroplasty Surgery India Cost of Urethroplasty Surgery India Urethroplasty Surgery Cost In India Low Cost Urethroplasty Surgery India Affordable Urethroplasty Surgery India

shared by indian-health on 16 Sep 22 - No Cached
  • indian-health on 16 Sep 22
     
    Thanks to Top urethroplasty surgeons in India high level of giving and dexterity, they leave no stone unturned to present nothing but the best of the healthcare services.
wheelchairindia9

Folding Power Wheelchair - 0 views

disabilityproduct.in/...POWER-WHEELCHAIR

Power wheelchair Convenient For Disabled People direction by a joystick sort Folding Power Wheelchair transport for elder people allows moving freely karma power wheelchair kp-10.3

shared by wheelchairindia9 on 10 Sep 15 - No Cached
  • wheelchairindia9 on 10 Sep 15
     
    GM LITE POWER WHEELCHAIR GM Lite Brushless Power Wheelchair with Batteries is a revolutionary light weight power wheelchair using brushless motor. It is the most economic power wheelchair without sacrificing safety & durability. The wheelchair promotes pressure redistribution, reduces downward sliding and helps maintain good posture. Specifications: 10 times longer life Lightest - 23 kg 5 year long life, safe LiFePO4 battery (10ah) High efficiency brushless hub motor 5 seconds folding and unfolding Easy to carry Load : 120 kg Speed : 8km/hr Range: 15 km Slope : 12% 24V180W brushless 8-inch gear hub motor
wheelchairindia9

Heavy Duty Wheelchair - 0 views

www.wheelchairindia.com/...HEAVY-DUTY-WHEELCHAIR

complex power wheelchairs mobility device system include postural support reduces downward sliding good flat pavements wheels and castors light weight power wheehair providing optimal mobility and function

shared by wheelchairindia9 on 11 May 15 - No Cached
  • wheelchairindia9 on 11 May 15
     
    Bariatric wheelchairs (often referred to as extra wide wheelchairs or heavy duty wheelchairs) are strong enough to accommodate almost any user. Just like lighter manual chairs, bariatric wheelchairs are all foldable and feature armrests and swing-away footrests - but they differ quite a bit in their construction. While lightweight wheelchairs often employ materials like aluminum or titanium alloy, a bariatric wheelchair is usually fashioned from steel. Karma 8020 X Heavy Duty Wheelchair: It comes with detachable swing away footrests. The wheel chair has flip-back armrests. It comes with centre of gravity adjustment. The wheel chair has wide profile casters. Seat Size 20'' inch & 22'' inch Total Weight 17 K.G. Heavy duty wheelchairs (often referred to as extra wide wheelchairs or bariatric wheelchairs) are sturdy enough to accommodate almost any user. Just their lighter cousins, manual chairs, heavy duty models all fold and feature arm rests and swing-away footrests - but they differ quite a bit in their construction. Heavy duty wheelchairs require more strength to push by the caregiver and by the user, if the chair is self-propelled. In some cases, it may be wise for the caregiver to ask for assistance from another person in order to push the wheelchair safely. Karma 8520 Heavy Duty Wheelchair: It comes with detachable swing away footrests. The wheel chair has flip-back armrests. It comes with centre of gravity adjustment. The wheel chair has wide profile casters. Seat Size 20'' inch & 22'' inch Total Weight 17 K.G. Features: Dual, reinforced steel cross braces. Supports individuals maximum weight. Reinforced steel frame provides added support. Heavy duty, nylon reinforced upholstery with a back carry pouch. Removable, reversible desk length arms. Adjustable leg support.
Nathan Goodyear

Magnesium metabolism in health and disease. [Dis Mon. 1988] - PubMed result - 0 views

www.ncbi.nlm.nih.gov/...3282851

magnesium disease health

shared by Nathan Goodyear on 21 Mar 11 - No Cached
  • Less than 1% of the total body magnesium is present in blood
  • A large segment of the U.S. population may have an inadequate intake of magnesium and may have a chronic latent magnesium deficiency that has been linked to atherosclerosis, myocardial infarction, hypertension, cancer, kidney stones, premenstrual syndrome, and psychiatric disorders.
  • Nathan Goodyear on 21 Mar 11
     
    Magnesium in health and disease
Nathan Goodyear

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.`
Nathan Goodyear

Pharmacologic ascorbic acid concentrations selectively kill cancer cells: Action as a p... - 0 views

www.pnas.org/...13604.full

IV vitamin C cancer ascorbic acid vitamin C H2O2 GPX glutathione Perioxidase

shared by Nathan Goodyear on 09 Feb 11 - Cached
  • Taken together, these data indicate that ascorbate at concentrations achieved only by i.v. administration may be a pro-drug for formation of H2O2, and that blood can be a delivery system of the pro-drug to tissues.
  • These findings give plausibility to i.v. ascorbic acid in cancer treatment, and have unexpected implications for treatment of infections where H2O2 may be beneficial
  • pharmacologic concentrations of ascorbate killed cancer but not normal cells, that cell death was dependent only on extracellular but not intracellular ascorbate, and that killing was dependent on extracellular hydrogen peroxide (H2O2) formation with ascorbate radical as an intermediate
  • ...48 more annotations...
  • Our data show that ascorbic acid selectively killed cancer but not normal cells, using concentrations that could only be achieved by i.v. administration
  • Ascorbate-mediated cell death was due to protein-dependent extracellular H2O2 generation, via ascorbate radical formation from ascorbate as the electron donor. Like glucose, when ascorbate is infused i.v., the resulting pharmacologic concentrations should distribute rapidly in the extracellular water space (42). We showed that such pharmacologic ascorbate concentrations in media, as a surrogate for extracellular fluid, generated ascorbate radical and H2O2. In contrast, the same pharmacologic ascorbate concentrations in whole blood generated little detectable ascorbate radical and no detectable H2O2. These findings can be accounted for by efficient and redundant H2O2 catabolic pathways in whole blood (e.g., catalase and glutathione peroxidase) relative to those in media or extracellular fluid
  • ascorbic acid administered i.v. in pharmacologic concentrations may serve as a pro-drug for H2O2 delivery to the extracellular milieu
  • H2O2 generated in blood is normally removed by catalase and glutathione peroxidase within red blood cells, with internal glutathione providing reducing equivalents
  • The electron source for glutathione is NADPH from the pentose shunt, via glucose-6-phosphate dehydrogenase. If activity of this enzyme is diminished, the predicted outcome is impaired H2O2 removal causing intravascular hemolysis, the observed clinical finding.
    • Nathan Goodyear
      Nathan Goodyear on 05 Mar 18
       
      The mechansism here is inadequate recycling of GSH due to lack of G6PD, build up of intracellular H2O2 and RBC lysis--hemolysis.
  • Only recently has it been understood that the discordant clinical findings can be explained by previously unrecognized fundamental pharmacokinetics properties of ascorbate
  • Intracellular transport of ascorbate is tightly controlled in relation to extracellular concentration
  • Intravenous ascorbate infusion is expected to drastically change extracellular but not intracellular concentrations
  • For i.v. ascorbate to be clinically useful in killing cancer cells, pharmacologic but not physiologic extracellular concentrations should be effective, independent of intracellular ascorbate concentrations.
    • Nathan Goodyear
      Nathan Goodyear on 05 Mar 18
       
      accumulation of extracellular vitamin C is the effect.
  • It is unknown why ascorbate, via H2O2, killed some cancer cells but not normal cells.
  • There was no correlation with ascorbate-induced cell death and glutathione, catalase activity, or glutathione peroxidase activity.
  • H2O2, as the product of pharmacologic ascorbate concentrations, has potential therapeutic uses in addition to cancer treatment, especially in infections
  • Neutrophils generate H2O2 from superoxide,
  • i.v. ascorbate is effective in some viral infections
  • H2O2 is toxic to hepatitis C
  • Use of ascorbate as an H2O2-delivery system against sensitive pathogens, viral or bacterial, has substantial clinical implications that deserve rapid exploration.
  • Recent pharmacokinetics studies in men and women show that 10 g of ascorbate given i.v. is expected to produce plasma concentrations of nearly 6 mM, which are >25-fold higher than those concentrations from the same oral dose
  • As much as a 70-fold difference in plasma concentrations is expected between oral and i.v. administration,
  • Complementary and alternative medicine practitioners worldwide currently use ascorbate i.v. in some patients, in part because there is no apparent harm
  • Human Burkitt's lymphoma cells
  • We first investigated whether ascorbate in pharmacologic concentrations selectively affected the survival of cancer cells by studying nine cancer cell lines
  • Clinical pharmacokinetics analyses show that pharmacologic concentrations of plasma ascorbate, from 0.3 to 15 mM, are achievable only from i.v. administration
  • plasma ascorbate concentrations from maximum possible oral doses cannot exceed 0.22 mM because of limited intestinal absorption
  • For five of the nine cancer cell lines, ascorbate concentrations causing a 50% decrease in cell survival (EC50 values) were less than 5 mM, a concentration easily achievable from i.v. infusion
  • All tested normal cells were insensitive to 20 mM ascorbate.
    • Nathan Goodyear
      Nathan Goodyear on 05 Mar 18
       
      meaning safe.
  • Lymphoma cells were selected because of their sensitivity to ascorbate
  • As ascorbate concentration increased, the pattern of death changed from apoptosis to pyknosis/necrosis, a pattern suggestive of H2O2-mediated cell death
  • Apoptosis occurred by 6 h after exposure, and cell death by pyknosis was ≈90% at 14 h after exposure
    • Nathan Goodyear
      Nathan Goodyear on 05 Mar 18
       
      work continued beyond the IVC therapy itself
  • In contrast to lymphoma cells, there was little or no killing of normal lymphocytes and monocytes by ascorbate
  • Ascorbate is transported into cells as such by sodium-dependent transporters, whereas dehydroascorbic acid is transported into cells by glucose transporters and then immediately reduced internally to ascorbate
  • Whether or not intracellular ascorbate was preloaded, extracellular ascorbate induced the same amount and type of death.
  • extracellular ascorbate in pharmacologic concentrations mediates death of lymphoma cells by apoptosis and pyknosis/necrosis, independently of intracellular ascorbate.
  • H2O2 as the effector species mediating pharmacologic ascorbate-induced cell death
  • Superoxide dismutase was not protective
  • Because these data implicated H2O2 in cell killing, we added H2O2 to lymphoma cells and studied death patterns using nuclear staining (19, 28). The death patterns found with exogenous H2O2 exposure were similar to those found with ascorbate
  • For both ascorbate and H2O2, death changed from apoptosis to pyknosis/necrosis as concentrations increased
  • Sensitivity to direct exposure to H2O2 was greater in lymphoma cells compared with normal lymphocytes and normal monocytes
  • There was no association between the EC50 for ascorbate-mediated cell death and intracellular glutathione concentrations, catalase activity, or glutathione peroxidase activity
  • H2O2 generation was dependent on time, ascorbate concentration, and the presence of trace amounts of serum in media
  • ascorbate radical is a surrogate marker for H2O2 formation.
  • whatever H2O2 is generated should be removed by glutathione peroxidase and catalase within red blood cells, because H2O2 is membrane permeable
  • The data are consistent with the hypothesis that ascorbate in pharmacologic concentrations is a pro-drug for H2O2 generation in the extracellular milieu but not in blood.
  • The occurrence of one predicted complication, oxalate kidney stones, is controversial
  • In patients with glucose-6-phosphate dehydrogenase deficiency, i.v. ascorbate is contraindicated because it causes intravascular hemolysis
  • ascorbate at pharmacologic concentrations in blood is a pro-drug for H2O2 delivery to tissues.
  • ascorbate, an electron-donor in such reactions, ironically initiates pro-oxidant chemistry and H2O2 formation
  • data here showed that ascorbate initiated H2O2 formation extracellularly, but H2O2 targets could be either intracellular or extracellular, because H2O2 is membrane permeant
    • Nathan Goodyear
      Nathan Goodyear on 05 Mar 18
       
      the conversion of ascorbate to H2O2 occurs extracellular
  • More than 100 patients have been described, presumably without glucose-6-phosphate dehydrogenase deficiency, who received 10 g or more of i.v. ascorbate with no reported adverse effects other than tumor lysis
  • Nathan Goodyear on 09 Feb 11
     
    IV vitamin C benefits cancer patients
1 - 18 of 18
Showing 20▼ items per page