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Biomedical subjects

D K Rassin

Publications and source records attributed to D K Rassin.

At least 55 records · Page 3Linked to original sources
PubMed1988

Growth and total body water in premature infants fed "in-utero" or "ex-utero".

Total body water and anthropometric measurements were compared in two groups of premature infants. The first group included infants with birthweights less than 1,501 g who were fed under usual clinical circumstances and studied at a bodyweight of 1,800-2,100 g ("Ex-utero"); the second group of infants had a birthweight of 1,800 to 2,100 g and were studied within the first week of life ("In-utero"). Triceps and subscapular skinfold thicknesses were significantly greater in "Ex-utero" infants than in "In-utero" infants, whereas body length was significantly greater in the latter group compared to the former. There were no difference in total body water, abdominal skinfold thickness, or midarm circumference between the two groups. These data suggest that feeding premature infants a standard premature infant formula under established guidelines leads to differences in body and fat distribution but not total body water compared to infants nourished "in utero".

Arm↗
PubMed1986

Hexosaminidase: a marker for healing after ischemic gut injury.

Serum hexosaminidase activity (HEX) is elevated with ischemic gut injury. To determine if subsequent decreases in HEX correlate with gut healing, 97 weanling rats were subjected to laparotomy at which alternate vascular bundles were ligated along the base of the entire anterior mesenteric artery arcade. Fifteen rats served as preoperative controls. After recovery, rats were allowed ad lib food and water. Groups were then killed at intervals, blood was drawn for HEX determination, and samples of small bowel were taken for histological evaluation. Microscopically, focal ischemic necrosis began at 6 hr. Between 12 and 48 hr, cellular changes were consistent with progressive ischemic injury. Evidence of healing was apparent beginning at 5 days and these histological changes correlated with changes in HEX. Thus HEX proves useful as a marker for gut healing in this model.

Animals↗
PubMed1986

A cobalamin metabolic defect with homocystinuria, methylmalonic aciduria and macrocytic anemia.

We have identified a patient with methylmalonic aciduria and homocystinuria due to a defect in cobalamin metabolism of the cb1C type mutant. At the time of admission at eight months of age the patient was malnourished, hypotonic and had macrocytic anemia. Neonatal screening for hypermethioninemia associated with homocystinuria had been normal. Serum vitamin B12 was markedly increased and folate concentration was above normal, as were urinary homocystine and methylmalonic acid. The patient had abnormal brain stem auditory and visual evoked potentials. Fibroblast activity of N5-methyltetrahydrofolate: homocysteine methyltransferase was reduced to approximately 10% of concurrent controls. A course of therapy with hydroxocobalamin resulted in a 90% reduction in excretion of methylmalonic acid and normalization of the evoked potentials. These studies support the efficacy of hydroxocobalamin therapy in this disease, suggest that methylmalonic acid may be the most appropriate metabolite to monitor for therapeutic response, and in importance of electrophysiologic studies in character in objectively monitoring the response to treatment metabolic disease.

5-Methyltetrahydrofolate-Homocysteine S-Methyltran↗
PubMed1986

Protein quantity and quality in term and preterm infants: effects on urine creatinine and expression of amino acid excretion data.

The effect of dietary protein quantity and quality on the excretion of creatinine in preterm and term neonatal infants has been investigated. Whey protein predominant formulas result in increased creatinine excretion as compared with either casein protein predominant formulas or with pooled human milk in preterm infants (p less than 0.001 by ANOVA). The volume of human milk (170 versus 185 versus 200 ml/kg/day) appears to have little effect in these infants. In term infants, few differences among the feeding groups were observed, although creatinine excretion did increase with time. The pattern of creatinine excretion among feeding groups was similar regardless of whether or not the data were expressed in milligrams per deciliter or in milligrams per 24 hours. Small correlations of creatinine excretion with birth weight were observed, but these appeared to vary, depending on the type of feeding. These diet-induced differences in creatinine excretion indicate the need for caution in expressing other urinary metabolites, such as amino acids, relative to creatinine excretion.

Amino Acids↗
PubMed1986

Development of serum hexosaminidase activity in infants.

Serum activity of hexosaminidases A and B has been measured to identify patients with Tay-Sachs and Sandhoff diseases, and may also be influenced by other clinical conditions including neonatal necrotizing enterocolitis. We have characterized the normal developmental pattern of hexosaminidase activity in serum by measuring this enzyme activity in 61 neonates of 27-40 weeks gestation who were followed from birth to age 4-8 weeks. Total serum hexosaminidase activity significantly increased with postnatal and gestational age, and with initiation of enteral feeding. We conclude that serum hexosaminidase activity in infants with clinical conditions that may influence serum activity of this enzyme must be compared to that in normal infants of similar gestational and postnatal ages.

Aging↗
PubMed1986

Attitudes toward breastfeeding.

To understand why some lower socioeconomic status mothers delivering at a state university hospital breastfeed, while others do not, 26 attitude items were administered in a survey of 358 mothers. A factor analysis of these items yielded four interpretable factors: benefits to infant, social inconvenience, personal inconvenience, and physical inconvenience-medical benefits to child. These factors were significantly related to breastfeeding within each level of ethnicity and marital status. The results imply that emphasizing the benefits for the infant, and providing strategies for minimizing personal inconveniences, should promote breastfeeding in these populations.

Black or African American↗
PubMed1984

Hexosaminidase: a biochemical marker for necrotizing enterocolitis in the preterm infant.

To evaluate hexosaminidase as a biochemical marker for the early detection of necrotizing enterocolitis in preterm infants, 33 preterm infants without necrotizing enterocolitis and 18 preterm infants with necrotizing enterocolitis had hexosaminidase activity measured during the course of their hospitalization. Although hexosaminidase activity could not identify those preterm infants with necrotizing enterocolitis who had impending perforation, the data strongly suggest that measurements of serum hexosaminidase activity may provide an early biochemical indication of the presence of necrotizing enterocolitis in the preterm infant. Hopefully, early detection of necrotizing enterocolitis in these infants will reduce the morbidity and mortality of this disease.

Clinical Enzyme Tests↗
PubMed1984

Role of taurine in feeding the low-birth-weight infant.

Plasma and urinary taurine concentrations, growth, nitrogen balance, duodenal bile salt concentration and pattern, fecal bile acid excretion, and intestinal fat absorption were determined in appropriate for gestational age low-birth-weight infants fed either a whey-predominant cow milk formula or the same formula supplemented with taurine (45 mumol/kg/day). Mean plasma taurine concentration in the two groups did not differ. Mean urinary taurine concentration in the control and supplemented groups over the entire study period were 2.67 +/- 0.69 and 12.41 +/- 5.20 mumol/dl, respectively (P less than 0.05). Urinary taurine concentration in the supplemented infants, however, decreased significantly during the study period. Neither growth nor nitrogen retention differed between the two groups. Mean duodenal concentrations of taurine as well as glycine conjugates of both cholate and chenodeoxycholate were higher in supplemented infants. Total duodenal bile salt concentration correlated positively with taurine status as reflected by urinary taurine excretion (r = 0.71); this correlation plus the lower duodenal cholesterol concentration in supplemented infants suggests that conversion of cholesterol to bile acids was greater in supplemented infants. Mean intestinal fat absorption in control and supplemented infants, however, did not differ.

Bile Acids and Salts↗
PubMed1984

Cysteine supplementation of total parenteral nutrition: the effect in beagle pups.

Total parenteral nutrition solutions supplemented with cysteine-HCl (S-TPN, 0.8 mmol/kg/day) were infused into beagle pups from day 10 of life to day 20 (n = 6). Another group of pups received unsupplemented TPN solutions (US-TPN) (n = 6). Fluid, protein, and energy intake from nonprotein sources were similar in both groups. Data from these two groups were compared and similar measurements in normally suckled pups were also compared with the two TPN groups (n = 6). There were significant differences in the rate of weight gain between the pups that received TPN and the pups that were suckled (P less than 0.01). Weight gain, hepatic DNA and protein concentrations, and cerebral DNA and protein concentrations in the pups that received TPN supplemented with cysteine were not different from similar measurements in pups that received unsupplemented TPN. Plasma total cyst(e)ine (Cyst(e)ine refers to the mixture in any proportion of the sulfhydryl (cysteine) and the disulfide (cystine) forms of this compound) concentrations in the cysteine-supplemented pups (7.9 +/- 1.2 mumol/DL, X +/- SD) were significantly greater than in the unsupplemented pups (4.9 +/- 1.8 mumol/DL). Hepatic glutathione concentrations in the supplemented pups (583 +/- 85 mumol/100 g liver) were also significantly greater than in the unsupplemented pups (392 +/- 113 mumol/100 g liver). These data suggest that the supplementation of TPN solutions with cysteine, even in an animal enzymatically capable of cysteine synthesis, has significant effects on glutathione synthesis.

Amino Acids↗
PubMed1984

Total parenteral nutrition in sick preterm infants: effects of cysteine supplementation with nitrogen intakes of 240 and 400 mg/kg/day.

The effects of supplementing total parenteral nutrition (TPN) solutions with cysteine were assessed at two different levels of nitrogen intake by determining nitrogen retention, sulfate excretion, and sulfur-containing amino acid concentrations. Ten infants received 72 mg/kg/day of cysteine-HCl in a TPN solution for a period of 6 days. Five of these infants received 251 +/- 48 (mean +/- SD) mg/kg/day of nitrogen, and five received 403 +/- 45 mg/kg/day of nitrogen. Two other groups of five infants each received unsupplemented TPN at nitrogen intakes of 235 +/- 48 and 412 +/- 54 mg/kg/day, respectively. Fluid and nonprotein caloric intakes were similar for all four groups. Cysteine supplementation increased plasma and urine free cyst(e)ine concentrations and enhanced total sulfur retention, but did not enhance nitrogen retention. [Cyst(e)ine refers to the mixture in any proportion of the sulfhydryl (cysteine) and the disulfide (cystine) forms of this compound.] Nitrogen retention, sulfate excretion, cyst(e)ine excretion, and plasma taurine concentrations increased as the result of the increase in nitrogen intake.

Cysteine↗
PubMed1984

Incidence of breast-feeding in a low socioeconomic group of mothers in the United States: ethnic patterns.

Breast-feeding has been shown to have increased in incidence during recent years in the United States. However, this increase is not particularly evident in lower socioeconomic groups. Factors associated with the decision to breast-feed or not were investigated in a population of 379 mothers. Self-completed questionnaires were obtained from 94.5% of these mothers. Data with respect to demographics, reproductive history, prenatal care, and education were collected. Only 27.2% of the study population indicated that they intended to breast-feed. Using the chi2 test for equality of proportions, marital status, head of household, maternal and paternal ethnicity, maternal education, income, and number of pregnancy were found to be the most important variables associated with breast-feeding. The effect of ethnicity predominated over that of the other demographic variables when they were examined jointly within ethnic groups. The effect of ethnicity was apparent when the number of each ethnic group in the study population was compared with the percent of that group that intended to breast-feed: 145 Anglo-Americans, 43.5% breast-feeding; 131 black Americans, 9.2%; 62 Mexican Americans, 22.6%; 19 others, 42.1%. The importance of ethnicity in the decision to breast-feed has probably been underestimated. Efforts to increase breast-feeding in the United States ought to be designed with full consideration of this factor.

Adolescent↗
PubMed1983

Social support, social influence, ethnicity and the breastfeeding decision.

A survey was conducted of all mothers delivering infants at a university medical center hospital in the month of July, 1981. The survey was conducted within 48 hours of delivery and addressed factors related to the breastfeeding decision. The mother's response to the question concerning choice of infant feeding was verified against the feeding records. One set of questions concerned the perceived general supportiveness toward breastfeeding of six individuals significant to the mother. Another set of questions identified who was most influential in the mother's breast or bottle feeding decision. The pattern of significant bivariate relationships between a person's supportiveness and breastfeeding varied across ethnic and maritial status groups. Single and multiple logistic analyses were conducted within ethnic groups to identify from whom support was most important for initiating breastfeeding. Among Black-Americans, support from a close friend was most important. Among Mexican-Americans, support from the mother's mother was most important. Among Anglo-Americans, support from the male partner was important. A broad variety of ensuing research issues are raised. An implication is that social support may be an important interventive variable, but the potentially supportive individual to be reached by an interventive program varies by ethnic group.

Black or African American↗
PubMed1983

Hexosaminidase: a marker for intestinal gangrene in necrotizing enterocolitis.

Detection of intestinal ischemia, prior to necrosis, is a major clinical problem. The lysosomal acid hydrolase, hexosaminidase (HEX), is known to be elevated in intestinal infarction. To determine if this enzyme could differentiate between partial intestinal ischemia and full-thickness intestinal gangrene, the following rat study was designed. Partial segmental intestinal ischemia was created by ligating alternate vascular bundles over a short (6 vessel) segment of the small-bowel mesentery, and complete segmental intestinal vascular occlusion was achieved by ligating the blood supply to the ileocecal segment. Preoperative serum HEX values were obtained from 15 animals. The rats were separated into one sham-operated and two intestinal ischemia groups. At four hours after surgery HEX values were determined. Total HEX activity was significantly elevated four hours after insult in both partial and complete intestinal ischemia, (P less than 0.005 and P less than 0.001 respectively). Total HEX activity was greater in complete intestinal ischemia than in partial ischemia, (P less than 0.05). Three neonates with intestinal perforation, secondary to necrotizing enterocolitis, were evaluated. The mean preoperative HEX activity was 1421 nmol/hr/mL serum and the mean post-resection HEX activity was 808 nmol/hr/mL serum. These data suggest that serum HEX activity may be a good marker for intestinal gangrene in neonates with necrotizing enterocolitis.

Animals↗
PubMed1983

Cyst(e)ine measurements during total parenteral nutrition.

Using a method that measures plasma protein-bound 1/2 cystine, plasma free cyst(e)ine, and urine free cyst(e)ine, we have observed that infants receiving total parenteral nutrition supplemented with cysteine-HCl have significantly higher plasma and urine free cyst(e)ine concentrations (11.3 +/- 3.4 microns/dl and 47.2 +/- 24.0 microns/dl, means +/- SD) than when 1/2 cystine concentrations are measured by automated amino acid analysis (7.4 +/- 2.0 microns/dl, plasma and 25.0 +/- 7.0 microns/dl, urine). These data suggest that both the sulfhydryl and disulfide form of cyst(e)ine must be measured to assess the effect of cysteine-HCl supplemented total parenteral nutrition.

Chemistry, Organic↗
PubMed1983

Detoxification of xenobiotics by glutathione S-transferases in erythrocytes: the transport of the conjugate of glutathione and 1-chloro-2,4-dinitrobenzene.

The incubation of human erythrocytes with 1-chloro-2,4-dinitrobenzene (CDNB) results in almost quantitative conjugation of glutathione (GSH) to form S-(2,4-dinitrophenyl) glutathione. The reaction is catalysed by erythrocyte glutathione S-transferase. During the present studies we have identified the conjugate in the incubation medium of CDNB-treated erythrocytes, indicating that the conjugate of GSH and CDNB is transported out by the erythrocytes. Quantitation of the conjugate in the incubation medium by amino acid analysis and thin layer chromatography indicates that the erythrocytes transport the conjugate at an approximate rate of 140 nmol/h/ml erythrocytes. The transport of the conjugate is inhibited by sodium fluoride. Exhaustion of ATP from the erythrocytes results in a significant decrease in the rate of transport which is restored with the regeneration of ATP by incubating the erythrocytes with adenine and inosine. This indicates that the transport of conjugate is an energy dependent process.

Adenosine Triphosphate↗
PubMed1983

Preterm infants fed human milk attain intrauterine weight gain.

The adequacy of human milk for low-birth-weight infants remains controversial. In this study, 35 healthy preterm infants with gestational age from 31 to 36 weeks and a birth weight less than 2200 g, were followed until they attained a weight of 2400 g at about 5 to 7 weeks of age. These infants were fed pooled, expressed human milk, partly supplemented with their own mother's milk, at intakes of 185 and 200 ml/kg/day. There were no consistent differences between the feeding groups in the rate of gain in weight, length, or head circumference, in serum total protein, in acid-base status, or in plasma amino acid concentrations. It is concluded that pooled, expressed human milk in volumes of 185 or 200 ml/kg/day produces a postnatal weight gain (196 +/- 6 or 205 +/- 7 g/week, respectively) in healthy preterm infants with a gestational age over 31 weeks which compares to intrauterine weight gain (207 g/week). This growth is achieved without apparent metabolic stress.

Amino Acids↗
PubMed1983

Maternal-fetal cyst(e)ine transfer.

In order to investigate the mechanisms by which cyst(e)ine (referring in the following to the mixture, in any proportion, of the sulfhydryl form of this compound - cysteine - and the disulfide form - cystine) transfer across the placenta to the fetus might be limited we first assessed the original observation that cyst(e)ine concentrations in fetal plasma are less than or equal to maternal cyst(e)ine concentrations. Second, we determined the capacity of the placenta to concentrate cyst(e)ine. And third, using an animal model, we determined the effects of providing excess cysteine to maternal rats on maternal-fetal cyst(e)ine transfer. Our data confirm (1) that cyst(e)ine is present in concentrations in human cord plasma that are equal to maternal plasma cyst(e)ine concentrations; (2) establish that cyst(e)ine is concentrated in the placenta, and (3) suggest that the incorporation of cyst(e)ine into glutathione in the placenta may limit the transfer of cyst(e)ine to the fetus.

Animals↗