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S H Hutner

Publications and source records attributed to S H Hutner.

At least 19 recordsLinked to original sources
PubMed1998

A practical assay of lipoate in biologic fluids and liver in health and disease.

A procedure for assaying lipoic acid concentration in biologic fluids and tissues was devised using a eukaryotic protozoan Tetrahymena thermophila. T.thermophila has a specific and sensitive (30 pg/ml) requirement for lipoic acid. Unlike humans and other microorganisms, T.thermophila can not synthesize lipoic acid; hence, its requirement for exogenous lipoic acid is specific. The lipoic acid supplied to T. thermophila by the processing of biologic fluids and tissues during the assay procedure, permits the derivation of a practical assay for lipoate concentration as described here. Lipoate concentration in biologic fluids and tissue obtained from healthy humans, compared to those obtained from patients with renal and liver disease, indicate deviations from normal during disease. Absorption chartings of 200 mg of DL-alpha-lipoic acid in humans indicate a peak concentration of lipoate in plasma 2 h after ingestion and then a steady descent of lipoate to a baseline level after 24 h. With this practical assay, it is now possible to chart lipoate's antioxidant activity and therapeutic action during health and disease.

Absorption↗
PubMed1996

Antioxidant survey to assess antagonism to redox stress using a prokaryotic and an eukaryotic system.

Using a prokaryote (Escherichia coli) and a metazoa-resembling eukaryote (Ochromonas danica), we surveyed antioxidants which might overcome redox stress imposed by menadione sodium bisulphite (MD) and buthionine sulphoximine (BSO). BSO oxidant stress was evident only in O. danica; MD oxidant stress was evident in both organisms. Glutathione, its precursors, e.g. cysteine, homocysteine, and 2-oxo-4-thiazolidine carboxylic acid, and red blood cells, emerged as prime antioxidants for relieving BSO and MD oxidant stress. BSO and MD oxidant activity and antioxidant-annulling effect in O. danica were judged comparable to those found in animal cells whereas the results E. coli were not entirely equivalent. The O. danica system emerged as a practical, rapid, and useful system for pinpointing oxidant stressors and antioxidants, and shows promise for studies with mammalian systems.

Antioxidants↗
PubMed1991

Role of 5'-deoxy-5'-methylthioadenosine in growth of several microbial B12 requirers.

5'-Deoxy-5'-Methylthioadenosine (MTA) figures in cellular methionine and polyamine syntheses. It replaces B12 for growth of the chrysomonad protozoan Poteriochromonas malhamensis at a ratio of MTA:B12 of approximatly 10,000,000:1 (by weight). MTA does not replace B12 for other B12-requirers, e.g.: Euglena gracilis, Lactobacillus leichmannii, and Escherichia coli 113-3. The methionine synergism for P. malhamensis growth is also negated when B12 activity is annulled by alkali treatment; MTA is not inactivated by such treatment. The growth promoting activity of various deoxynucloesides and deoxynucloetides for P. malhamensis and other B12-requirers is reported here due to contamination by cobalamins. Ethionine antagonizes the growth-enhancing effect of MTA, methionine, and B12, individually and collectively -evidence that MTA plays a role in supplying methionine for P. malhamensis growth. MTA concentrations in body fluids and mammalian tissues are too low to interfere with the use of P. malhamensis for estimating only metabolically active B12.

Adenosine↗
PubMed1991

Hypovitaminosis C in patients treated with high-dose interleukin 2 and lymphokine-activated killer cells.

Patients (n = 15) with metastatic malignant melanoma, hypernephroma, and colon carcinoma received a three-phase adoptive immunotherapy protocol: phase 1, 10(5) units (high-dose) interleukin-2 (IL-2) iv every 8 h or 1 mg/m2 continuous intravenous infusion; phase 2, 6.5 d rest + leukapheresis; phase 3, 4 d of high-dose IL-2 plus three infusions of autologous lymphokine-activated killer cells. Toxicities of treatment included fever, chills, tachycardia, hypotension, vomiting, diarrhea, and fluid retention. Patients entering the trial were not malnourished, and mean plasma ascorbic acid concentrations before therapy were normal (36.3 +/- 14.2 mumol/L). Mean concentrations dropped by 80% after the first phase of treatment with high-dose IL-2 alone (to 7.4 +/- 4.5 mumol/L). Mean plasma ascorbic acid concentrations remained severely depleted (between 4.5 and 7.4 mumol/L) throughout the remainder of the 15-d treatment. Ascorbic acid concentrations became undetectable (less than 2.8 mumol/L) in 12/15 patients during this time. Blood pantothenate and plasma vitamin E concentrations remained within normal limits in all patients tested throughout the phases of therapy.

Adult↗
PubMed1987

Severe hypovitaminosis C occurring as the result of adoptive immunotherapy with high-dose interleukin 2 and lymphokine-activated killer cells.

Adoptive immunotherapy of human cancer was investigated in our institution as part of a National Cancer Institute extramural group study. This treatment, for patients with metastatic malignant melanoma, hypernephroma, and colon carcinoma, consisted of three phases: (a) 5 days of i.v. high-dose (10(5) units/kg every 8 h) interleukin 2, (b) 6 1/2 days of rest plus leukapheresis; and (c) 4 days of high-dose interleukin 2 plus three infusions of autologous lymphokine-activated killer cells. Toxicities included fever, chills, tachycardia, hypotension, vomiting, diarrhea, and fluid retention. Ascorbic acid is known to be important to cell-mediated immunity, and it has been reported to be depleted during physiologically stressful events. Therefore, we determined plasma ascorbic acid levels in patients (n = 11) before adoptive immunotherapy and before and after Phases 1, 2, and 3 of treatment. Patients entering the trial were not malnourished. Mean plasma ascorbic acid levels were normal (0.64 +/- 0.25 mg/dl) before therapy. Mean levels dropped by 80% after the first phase of treatment with high-dose interleukin 2 alone (0.13 +/- 0.08 mg/dl). Mean plasma ascorbic acid levels remained severely depleted (0.08 to 0.13 mg/dl) throughout the remainder of the treatment, becoming undetectable (less than 0.05 mg/dl) in eight of 11 patients during this time. Values obtained from 24-h urine collections on two of two patients indicated that ascorbate was not excreted in the urine. Plasma ascorbic acid normalized in three of three patients tested 1 mo after the completion of treatment. Unlike the results for ascorbic acid, blood pantothenate and plasma vitamin E remained within normal limits in all 11 patients throughout the phases of therapy. Responders (n = 3) differed from nonresponders (n = 8) in that plasma ascorbate levels in the former recovered to at least 0.1 mg/dl (frank clinical scurvy) during Phases 2 and 3, whereas levels in the latter fell below this level.

Adult↗
PubMed1987

Polyamines antagonize both the antileukemic activity and the reverse transcriptase stimulatory activity of 4,4'-diacetyldiphenylurea bis(guanylhydrazone) (DDUG).

(Diacetyldiphenylurea)bis(guanylhydrazone) (DDUG) functions as a cationic trypanocide antagonized in vivo by exogenous concomitant addition of the biologically active polyamine, spermine. It also inhibits the DNA polymerases of L1210 murine leukemia cells. We have found that DDUG stimulates Rauscher murine leukemia virus DNA polymerase activity in a manner similar to polyamines. Such stimulation does not occur if DNA synthesis is carried out on spermine + activated DNA complexes. We also show that the in vivo antileukemic activity of DDUG in the L1210 ascites mouse model is antagonized by biologically active polyamines. These studies suggest a new intracellular target for the antileukemic activity of DDUG: interference with polyamine function.

Animals↗
PubMed1986

Determination of metabolically active B12 and inactive B12 analog titers in human blood using several microbial reagents and a radiodilution assay.

Metabolically active B12 analogs and inactive B12 analogs were measured in plasma, red blood cells (RBC), and pooled pernicious anemia serum. B12 values by Lactobacillus leichmannii, Escherichia coli, Euglena gracilis, and radioisotope dilution method (RIDA) as assays for total B12 (active analogs + inactive analogs) were compared to Ochromonas malhamensis values as index of only metabolically active B12. B12 values above those with O malhamensis distinguished inactive analogs from active B12. Inactive analogs contribute 85, 97, 135, and 163% above active B12 activity in normal plasma when E gracilis, L leichmannii, RIDA, and E coli, respectively, were used for B12 analysis. RIDA B12 determinations for active B12 in plasma showed that 44% of the B12 measured was still due to inactive analogs when compared to O malhamensis B12 activity. Inactive B12 analogs contributed 21, 151, and 224% above O malhamensis active B12 in RBC when E gracilis, L leichmannii, and E coli, respectively, were used.

Anemia, Pernicious↗
PubMed1984

New drug combination for experimental late-stage African trypanosomiasis: DL-alpha-difluoromethylornithine (DFMO) with suramin.

Using a previously described mouse model of late-stage African trypanosomiasis (i.e., involvement of the central nervous system), we demonstrate that a combination of DL-alpha-difluoromethylornithine (DFMO) and suramin is curative. In the curative protocol, DFMO is given as a 2% solution in the drinking water for 14 days and suramin is administered as a single dose (20 mg/kg intravenously) on day 1 of DFMO administration. Since: 1) DFMO has very low toxicity, 2) suramin is one of the least toxic of the presently used trypanocides, and 3) suramin and DFMO act synergistically in mouse models of both acute and late stage trypanosomiasis, we conclude that this combination offers special promise in the treatment of African trypanosomiasis in man.

Animals↗
PubMed1984

Antitumor phthalanilides active in acute and chronic Trypanosoma brucei brucei murine infections.

A series of phthalanilides and related compounds were tested on a short-term, fulminating, mouse infection of Trypanosoma brucei brucei (EATRO 110 isolate). The most effective compound was [4,4'-bis (4-methylimidazolin-2-yl)-terephthalanilide] which had a cure rate of 75% at 0.1 mg/kg body weight and 100% at 0.5 mg/kg when administered as three single daily intraperitoneal injections starting 24 hours post-infection. Several related phthalanilides and similarly substituted ureas showed definite but lower activity. In tests with a chronic neurotropic T. b. brucei isolate (TREU 667), cure rates greater than 90% were obtained with 10 or 25 mg/kg [4,4'-bis(4-methylimidazolin-2-yl)-terephthalanilide]. Cured animals survived for at least 200 days after infection with no evidence of recrudescence of parasitemia or of toxicity; blood or brain homogenates of cured animals were non-infective to immunosuppressed animals. These studies indicate that this series of compounds, previously studied as antitumor agents, should be re-examined as potential trypanocides.

Anilides↗
PubMed1983

In vivo effects of alpha-DL-difluoromethylornithine on the metabolism and morphology of Trypanosoma brucei brucei.

The EATRO 110 isolate of Trypanosoma brucei brucei was grown in rats for 60 h and the animals treated with the ornithine decarboxylase inhibitor alpha-DL-difluoromethylornithine 12 h or 36 h prior to sacrifice. Control untreated animals died 72-80 h after infection. Treated parasites were shorter and broader than the predominantly long slender forms found in untreated controls and many had two or more nuclei and kinetoplasts. Trypanosomes were purified from blood and examined for disruption of polyamine metabolism. ODC activity decreased by more than 99% after 12 h treatment and putrescine and spermidine levels also decreased dramatically. Spermine, not normally present in control cells, increased to detectable, low levels (less than 1 nmol mg-1 protein) after 36 h treatment. alpha-DL-Difluoromethylornithine-treated cells were unable to synthesize putrescine from [3H]ornithine but were able to convert [3H]putrescine + methionine to spermidine. 12-h treated parasites responded to polyamine depletion by assimilating radiolabeled polyamines in vitro at 2- to 4-times the rate of untreated cells. The metabolism of S-adenosylmethionine was also altered in treated parasites: decarboxylated S-adenosylmethionine increased more than 1000-fold over untreated cells while S-adenosylmethionine decarboxylase activity, associated with the formation of spermidine and spermine in other eukaryotes, paradoxically declined in treated cells. Synthesis of macromolecules was perturbed in treated parasites: rates of DNA and RNA synthesis declined 50-100%, while protein synthesis increased up to 4-fold in 36-h treated cells. alpha-DL-Difluoromethylornithine treatment progressively limits the parasites' ability to synthesize nucleic acids and blocks cytokinesis while inducing morphological changes resembling long slender leads to short stumpy transformation.

Animals↗
PubMed1982

In vivo and in vitro activity by diverse chelators against Trypanosoma brucei brucei.

A system of prescreens and screen has been developed to select chelators as potential drugs against Trypanosoma brucei brucei EATRO 110. The chelators tested were nearly all commercially available, low molecular, and having moderate to high affinity for Fe(III). We prescreened 70 compounds showing heme-sparing or inhibitory activity in a Crithidia fasciculata growth system having excess Fe and minimal hemin. Of these, 45 were highly trypanocidal for suspensions of bloodstream T. b. brucei; criteria of activity here were immobilization, lysis, and loss of infectivity. Eighteen of the chelators highly active in the suspension prescreen were tried in T. b. brucei-infected mice. Thirteen of these chelators were curative in mice with 24-h infections, that is, they allowed survival greater than 30 days beyond the untreated controls. 3,4-Dihydroxycinnamic acid (caffeic acid), 2,9-dimethyl-1, 10 phenanthroline (neocuproine), and 2-pyridinecarboxaldehyde-2-pyridyl-hydrazone cured five out of five mice after an i.v dose of 100 mg/kg. Salicylaldehyde thiosemicarbazone cured five out of five mice at an i.p. dose of 500 mg/kg. Lesser activity was shown by several other chelators.

Animals↗
PubMed1982

Ornithine decarboxylase in Trypanosoma brucei brucei: evidence for selective toxicity of difluoromethylornithine.

Activity of ornithine decarboxylase, the major rate limiting enzyme of polyamine biosynthesis, was determined in bloodstream trypomastigotes of Trypanosoma brucei brucei. The enzyme required pyridoxal-5'-phosphate, dithiothreitol and EDTA for optimal activity. Several properties of the enzyme were investigated and compared to the mammalian enzyme. Most notably, the parasite enzyme was greater than 60-fold more sensitive to the inhibitor DL-alpha-difluoromethylornithine than its mammalian counterpart, thus making it an attractive target for chemotherapy.

Animals↗