PubMed Health⌕ Search

Biomedical subjects

O M Rennert

Publications and source records attributed to O M Rennert.

At least 73 records · Page 4Linked to original sources
PubMed1984

Interstrain variation in acute toxic response to caffeine among inbred mice.

Acute toxic dosage-dependent behavioral effects of caffeine were compared in adult males from seven inbred mouse strains (A/J, BALB/cJ, CBA/J, C3H/HeJ, C57BL/6J, DBA/2J, SWR/J). C57BL/6J, chosen as a "prototypic" mouse strain, was used to determine behavioral responses to a broad range (5-500 mg/kg) of caffeine doses. Five phenotypic characteristics--locomotor activity, righting ability, clonic seizure induction, stress-induced lethality, death without external stress--were scored at various caffeine doses in drug-naive animals under empirically optimized, rigidly constant experimental conditions. Mice (n = 12 for each point) received single IP injections of a fixed volume/g body weight of physiological saline carrier with or without caffeine in doses ranging from 125-500 mg/kg. Loss of righting ability was scored at 1, 3, 5 min post dosing and at 5 min intervals thereafter for 20 min. In the same animals the occurrence of clonic seizures was scored as to time of onset and severity for 20 min after drug administration. When these proceeded to tonic seizures, death occurred in less than 20 min. Animals surviving for 20 min were immediately stressed by a swim test in 25 degrees C water, and death-producing tonic seizures were scored for 2 min. In other animals locomotor activity was measured 15 or 60 min after caffeine administration. By any single behavioral criterion or a combination of these criteria, marked differences in response to toxic caffeine doses were observed between strains. These results indicate that behavioral toxicity testing of alkylxanthines in a single mouse strain may be misleading and suggest that toxic responses of the central nervous system to this class of compounds are genetically influenced in mammals.

Animals↗
PubMed1984

Studies of lipids, lipoproteins, and apolipoproteins in Menkes' disease.

Three patients with Menkes' disease, an inherited disorder of copper transport, were studied to determine whether the copper deficiency was associated with a lipoprotein disorder. Hypocuprinemia was documented in all three cases. Two patients had severe copper and ceruloplasmin deficiencies, whereas the third patient had a less severe deficiency. Hypertriglyceridemia was observed in the first patient, and elevations in triglyceride, cholesterol, apolipoprotein B (ApoB), and apolipoprotein C-III (ApoC-III) occurred predominantly in the very low density lipoprotein fraction (VLDL). This patient had normal lipoprotein lipase activity but mild glucose intolerance. The second patient had a borderline high cholesterol level with normal plasma triglycerides and apolipoproteins, whereas the third patient appeared to have normal total cholesterol but slightly higher triglycerides with elevated plasma apolipoprotein E (ApoE). No striking differences were observed in the chemical composition of all lipoprotein subfractions between patients and controls except that the neutral lipid content of VLDL was higher in patients than in controls. The ApoB was initially normal in molecular weight but degraded faster than the controls during storage. The appearance of the major low density lipoprotein (LDL) fraction of the first two patients was opaque white, in contrast to clear yellow in the third patient and in the age- and diet-matched controls. This abnormal appearance of LDL in these patients was associated with low plasma levels of beta-carotene and ceruloplasmin. These findings suggest that decreased serum copper levels may be associated with lipid and lipoprotein abnormalities and may enhance lipid peroxidation of LDL accounting for the color change.(ABSTRACT TRUNCATED AT 250 WORDS)

Apolipoprotein C-III↗
PubMed1983

Androgen receptors in the brain of neonatal normal male and androgen insensitive rats.

Androgen binding was investigated in the cytosol of brains from neonatal normal and tfm rats using sucrose gradient and charcoal assay. The neonatal normal rat brain contains androgen receptors which sediment at 8S in a sucrose gradient at low ionic strength and at 4S in the presence of 0.5M KC1. These receptors have a high affinity (Kd = 1.2 X 10(-9)M) for dihydrotestosterone (DHT), with a binding capacity of 7.3 X 10(-15) moles/mg cytosol protein. By contrast, there is very little, if any, high affinity androgen receptors in the neonatal tfm rat brain. Apparently, metabolism of testosterone does not affect androgen binding in the neonatal rat brain. The presence of these receptors and the occurrence of aromatization in the brain of neonatal rats are discussed in relation to their possible roles in sexual differentiation of the brain.

Animals↗
PubMed1983

Zinc metabolism in testicular feminization and surgical cryptorchid testes in rats.

Rats with testicular feminization (Tfm) had been reported to have a testis specific zinc deficiency. In this report it is demonstrated that this organ specific zinc deficiency was not corrected by intraperitoneal zinc administration. Normal littermates on the other hand showed a positive testicular response to zinc administration. The increased testicular zinc level in control animals returned to normal 1 week after the zinc treatment probably due to the fast turnover of this element in the testis. Not only surgically induced cryptorchidism but also surgical cryptorchidism and epididymodeferentectomy (to simulate Tfm conditions in normal adult rats) caused a drastic reduction in testicular zinc level. Unlike in Tfm rats, however, the decrease in zinc content in operated animals was not accompanied by a corresponding decrease in alkaline phosphatase activity. Zinc concentration and alkaline phosphatase activity in plasma or other organs were not affected by the surgical procedure. The testicular copper content in the operated animals was higher than that of the unoperated controls.

Alkaline Phosphatase↗
PubMed1983

Polyamine metabolism in McCoy cells: I. Comparative studies of extracellular polyamine conjugated proteins of human fibroblast and McCoy cultures.

polyamine conjugated proteins were identified in culture medium from both human skin fibroblasts and transformed mouse cells (McCoy cells). Sephadex G-100 column chromatography of medium allowed identification of two polyamine conjugated proteins from both types of cell cultures; one with Mr greater than 100,000 (MP1) and one with Mr = 60,000-70,000 (MP2). Human skin fibroblast MP1 contained putrescine and spermidine while MP1 from McCoy cultures contained putrescine, spermidine and spermine. MP2 isolated from both cultures contained all three polyamines. The relative concentration of polyamines in MP1 and MP2 for human fibroblasts and McCoy cells were different. The spermidine and spermine associated with MP1 and MP2 of McCoy cultures was covalently bound while for putrescine only 70.5% in MP1 and MP2 of McCoy cultures was covalently bound while for putrescine only 70.5% in MP1 and 74.5% in MP2 was covalently bound. The covalent nature of the polyamine protein conjugation was confirmed by autoradiography following isogel agarose isoelectric focusing. MP2 was resolved into three radiolabeled proteins with pI's between 5.25 and 5.20. Both MP1 and MP2 of McCoy cultures were heterogeneous. MP1 consisted of at least five proteins with Mr's of 180,000, 38,000, 76,000 and 68,000. The major protein (or proteins) had a pI of 5.25. MP2 consisted of at least three proteins with Mr's 72,000, 68,000 and 62,000; their pI's were between 5.20 and 5.25.

Cells, Cultured↗
PubMed1983

Polyamine metabolism in McCoy cells: II. Cellular origin of excreted polyamine conjugated proteins.

Incubation of McCoy cultures with medium containing 14C-putrescine resulted in the incorporation of 14C-polyamine into intracellular proteins. A greater than 100,000 dalton 14C-polyamine conjugated protein was present in the McCoy cell lysate supernatant (CLSP). CLSP was heterogeneous containing proteins with pIs ranging from 4.55 to 5.50. The major proteins had pIs of 4.55 and 5.20. Electrophoresis of solubilized McCoy cell lysate pellet revealed a 14C-polyamine conjugated protein peak with Mr approximately or equal to 70,000 (CLPP). Both CLSP and CLPP contained bound polyamine. The major CLSP polyamine was spermidine while spermine exceeded the other two polyamines (putrescine and spermidine) in CLPP. About 25% of the polyamines associated with CLSP and CLPP were covalently bound with the exception of CLSP putrescine where 62.1% was covalently bound. Results suggested the presence of a polyamine protein isopeptide bond in CLSP. Sephadex gel filtration of cultured medium resulted in the identification of two macromolecular polyamine-containing fractions (MP1, Mr greater than 100,000 and MP2, M = 60,000-70,000). Antibody raised in rabbits against a membrane-organelle preparation cross-reacted with Sephadex gel filtration derived MP1 but not with peak MP2 suggesting that MP1 but not MP2 might be a membrane constituent. Antibody raised against medium polyamine conjugated protein peak 2 (MP2) cross-reacted with the cell lysate supernatant indicating that MP2 was present in the cytosol. It did not cross-react with the cell lysate pellet preparation. Antibody against MP2 also formed a precipitation band with MP1 indicating that there might be a common antigenic site on MP1 and MP2.

Cell Compartmentation↗
PubMed1983

Polyamine metabolism in McCoy cells: III. Comparative studies of the metabolic fate of exogenous putrescine in human fibroblasts and McCoy cultures.

The fate of exogenously added 14C-putrescine following incubation for 24 hours with McCoy and human skin fibroblast cultures was examined. The nature of the polyamine derivatives found were quite different indicative of a difference in the cellular metabolism of polyamines. Exogenously added putrescine (PUT) was metabolized by both McCoy and human skin fibroblast cultures to form spermidine (SPD), spermine (SPM), gamma-aminobutyric acid (GABA) and some unidentified compounds. Within the experimental period of observation, human cultured fibroblasts metabolized PUT more efficiently than McCoy cells and converted more than 50% of it into SPD, SPM, GABA and unknown compounds. Monoacetyl putrescine (MAP) was formed by human skin fibroblasts. It was mainly identified in the culture medium. No MAP was detectable either intracellularly or extracellularly in McCoy cultures. The percentage of 14C-radioactivity found as PUT in the culture medium was greater in McCoy cells (86.0%) than in human fibroblasts (53.9%). The reverse was true for the percentage distribution of 14C-radioactivity as PUT inside the cells. No low Mr conjugates of SPD or SPM were found in the medium or intracellularly with either culture type. Some low Mr putrescine conjugates were found in the culture media; these were identified by the liberation of PUT upon acid hydrolysis.

Cell Compartmentation↗
PubMed1982

Histochemical studies of fibroblasts from patients with Menkes kinky hair disease and Wilson's disease.

Cultured fibroblasts from Menkes kinky hair disease patients showed markedly reduced succinate dehydrogenase and amine oxidase activities. Cytochrome oxidase activity, however, was greatly reduced in some cells and almost normal in others. Cultured fibroblasts from patients with Wilson's disease showed moderately reduced succinate dehydrogenase and cytochrome oxidase activities. Amine oxidase activity was only slightly reduced when compared to that of normal. These results indicated that the histochemical phenotype observed in fibroblasts from patients with Menkes kinky hair disease and Wilson's disease were distinctly different from each other and from normal fibroblasts.

Amine Oxidase (Copper-Containing)↗
PubMed1982

Serum copper and ceruloplasmin in preterm infants: prospective study.

The postnatal time courses in preterm infants (30.0 weeks mean gestational age) of serum copper and ceruloplasmin (Cp) are described and compared. Serum copper was measured by nonflame atomic absorption spectrophotometry and serum Cp was measured by both immunodiffusion (Cpi) and enzyme assay (Cpe). With the exception of Cpe between 7 and 11 weeks of age, correlations among the three laboratory parameters were excellent. Following an early rise in all values, a plateau was seen in copper and Cpi between 5 and 11 weeks; Cpe showed a discordant fall at 7 to 11 weeks of age. After 11 weeks a secondary and definitive rise in all values was seen. Examination of individual time courses indicates the existence of a subgroup of infants with falling values between 5 and 11 weeks of age. Preterm infants had significantly higher serum copper (0.53 +/- 0.05 micrograms/ml) at a mean postnatal age of 10 weeks (39-41 weeks postconception) than did full-term infants (0.44 +/- 0.04 microns/ml) of similar postconceptional age. Low serum copper values were correlated with parenteral nutrition deficient in copper, with increased growth rates, and with twin pregnancies. It is concluded that extrauterine life in preterm infants is associated with precocious rises in serum copper and Cp values. The subgroup of infants with falling values may represent subclinically copper-deficient infants. This subgroup may bias the results of grouped data downwards. A role for nutritional factors in the delayed postnatal rise of serum copper and Cp values in preterm infants cannot be excluded on the basis of current knowledge.

Ceruloplasmin↗
PubMed1982

Comparative studies of manganese binding in human breast milk, bovine milk and infant formula.

The difference in ligand localization of manganese in human breast milk, cow's milk and infant formula was investigated. Extrinsic labeling technique was used and the different manganese-binding ligands were separated by gel permeation column chromatography. Manganese was found to bind to different ligands in human milk, cow's milk and infant formula. In human milk, manganese was bound by two high molecular weight proteins, the major one of 407,300 daltons and the minor one of 128,800 daltons. The 407,300-dalton protein was homogeneous with respect to molecular weight and charge and upon saturation with manganese had a metal to protein ratio of 1:1. Cow's milk had three manganese-binding species, with molecular weights of 234,000, 83,200 and less than 1000. The 234,000-dalton manganese-binding fraction was heterogeneous and contained several species with slightly different charge as revealed by DEAE-Sephacel ion-exchange chromatography. Infant formula on the other hand had no high molecular weight manganese-binding species. All the extrinsically added manganese was found in fractions with molecular weight of less than 1000.

Animals↗
PubMed1982

Acid mucopolysaccharide (AMPS) abnormality in multiple sulfatase deficiency: chemical compositions of AMPS in urine and liver.

Extensive chemical analyses of acid mucopolysaccharides (AMPS) were carried out in the urine and tissue (liver and brain) from a Japanese patient and two European patients with multiple sulfatase deficiency (MSD). The Japanese patient with MSD contained excessive quantities of heparan sulfate and moderately increased chondroitin sulfate A/C. Urinary excretion of AMPS in MSD heterozygotes was increased 2-fold compared to our controls. The urinary pattern of AMPS in the mother of the MSD patient showed an increase of 18% heparan sulfate and 36% dermatan sulfate whereas the urinary excretion pattern in the father was increased 21% for heparan sulfate as contrasted to controls (chondroitin sulfate A, 50-52%; chondroitin sulfate C, 38-46%; and heparan sulfate, 3-10%). Seventy-five % of the AMPS and the MSD liver was heparan sulfate rather than dermatan sulfate. The degree of accumulation of AMPS in the MSD liver was 30-50 times that of the control. Cerebral gray matter from the MSD patient contained 30-40 times that of control (relative increase of heparan and dermatan sulfate) whereas only a 5-fold increase was observed in white matter. It seems that a major site of accumulated AMPS appears to be in the gray matter. Carbohydrate analysis of the AMPS obtained from MSD urine and tissues was performed by: enzyme digestion with testicular hyaluronidase, heparitinase and chondroitinase ABC, cellulose acetate electrophoresis, Dowex-1 column chromatography and amino sugar analysis by amino acid analyzer. These findings indicate that the major accumulated AMPS in MSD urine and liver is heparan sulfate and thus, the predominant AMPS metabolic defect in MSD is heparan sulfate degradation.

Brain Chemistry↗
PubMed1982

Increased cerebrospinal fluid free amino acid concentrations in children with bacterial meningitis.

19 free amino acids were measured by Durrum high pressure chromatography in the cerebrospinal fluid of 19 children, 9 with and 10 without bacterial meningitis. Each of the amino acids, except for gamma-amino butyric acid, was significantly increased in meningitis. Values were elevated upon admission of these patients to the hospital, but the highest concentration for most of the amino acids was noted in specimens collected 24-48 h after initiation of antibiotic treatment. Upon the completion of successful antibiotic therapy, the amino acid concentrations returned to normal or near normal levels.

Amino Acids↗
PubMed1981

On the formation of amino acids deriving from spermidine and spermine.

Evidence obtained from experiments with rats and mice is presented suggesting that the naturally occurring amino acids putreanine and N8-(2-carboxyethyl)spermidine, and most probably also related compounds deriving from the polyamines spermidine and spermine by oxidative metabolism, are formed within two anatomical compartments. In the first step polyamines are converted into aldehydes by serum spermine oxidase in the circulation. A certain portion of these aldehydes can be taken up by liver and other organs and transformed by aldehyde dehydrogenase into the corresponding amino acids. Putreanine is not only derived from spermidine, but can also be formed from N8-(2-carboxyethyl)spermidine by oxidative deamination, catalysed by serum spermine oxidase, and subsequent spontaneous elimination of acrolein.

Amino Acids↗