Biomedical subjects

J E Williams

Publications and source records attributed to J E Williams.

At least 91 records · Page 5Linked to original sources

PubMed1992

Iron absorption and incorporation into red blood cells by very low birth weight infants: studies with the stable isotope 58Fe.

Measurements of iron absorption and incorporation into RBCs were obtained with the stable isotope 58Fe, administered as a reference dose, in 11 premature infants with birth weights between 780 and 1,520 g and gestational ages between 24 and 33 weeks. Each study included a timed stool and urine collection, nasogastric tube administration of a single dose of about 228 micrograms of 58Fe/kg of body weight (as FeSO4, with 10 mg/kg of vitamin C) between feedings, and blood samples before 58Fe (day 1) and then 2 weeks (day 15) later. Gastrointestinal absorption of the 58Fe dose as measured by fecal isotope balance was 41.6 +/- 17.6% (mean +/- SD). However, only 12.0 +/- 9.6% of the 58Fe dose (28.7 +/- 22.3% of the absorbed 58Fe dose) was incorporated into RBCs on day 15. 58Fe absorption and 58Fe incorporation into RBCs on day 15 were significantly correlated with the hemoglobin concentration and reticulocyte count on day 1. Transfusion history did not affect 58Fe absorption or 58Fe incorporation into RBCs. We conclude that concurrent measurement of 58Fe absorption with fecal monitoring and of 58Fe incorporation into RBCs permits a better understanding of the fate of iron ingested by premature infants than either measurement alone.

Algorithms↗

PubMed1992

Feeding wash water solids to sows during gestation and lactation: sow productivity, pig performance, and tissue compositions.

Diets containing 0, 10, or 20% dried wash water solids (WWS) from a milk processing plant were fed to 54 Yorkshire gilts (160 to 270 kg) for five parities. Feed intake, weight changes, and morbidity of sows were measured; number of pigs per litter, birth weight, and weight gain of pigs were also determined. Blood, tissue, and milk samples were taken from sows for hematological and mineral analyses, and tissue samples were taken from newborn pigs from each treatment per parity. Overall, initial sow weight, sow weight at weaning, and weight losses were not affected (P greater than .05) by treatment. At 107 d of gestation, overall weights decreased (P less than .05) linearly with level of WWS in the diet. The number of pigs per litter and weight of pigs were not affected (P greater than .10) by diet. Concentrations of NA (P less than .10) and Cd (P less than .05) were lower in kidney of sows fed 20% WWS, and concentrations of Zn were lower in bone and in kidney of sows fed the 20% WWS diet. The Sr and Ba concentrations increased (P less than .05, P less than .10) linearly in bone from sows with level of WWS in the diet. In pigs, concentrations of Mn in kidney and Zn in liver were lower for the 20% WWS treatment. In conclusion, feeding WWS to sows over five parities had minimal adverse effects on sow productivity and pig performance; the reduction in Zn concentrations in tissues of sows and pigs seemed to be related to the Ca content of WWS.

Animal Feed↗

PubMed1992

Cariostatic and ultraconservative sealed restorations: six-year results.

The objective of this clinical study was to determine the ability of an ultraconservative, sealed composite resin restoration, without a traditional cavity preparation and without the removal of the carious lesion, to arrest Class I caries. Tooth preparation was limited to placing a bevel in the enamel. These restorations were compared, over 6 years, with (1) ultraconservative, localized, sealed amalgam restorations with no extension for prevention and (2) traditional, unsealed amalgam restorations with the usual extension for prevention outline form. Caries was arrested by the ultraconservative, sealed composite resin restorations for 6 years. Complete sealant retention on the sealed amalgam restorations was somewhat lower than that on the sealed composite resin restorations; conversely, partial sealant retention was higher for the sealed amalgam group. The marginal integrity of the sealed amalgam restorations was significantly superior to that of the unsealed amalgam restorations. The sealant also protected Class I posterior composite resin restorations against wear.

Adolescent↗

PubMed1992

Sealed restorations: 5-year results.

This clinical study determined the feasibility of a sealed resin composite restoration to arrest dental caries using a minimal tooth preparation: a bevel in enamel only without removal of the carious lesion. These ultra-conservative sealed composite restorations placed over caries (CompS/C) were compared with ultra-conservative sealed amalgam restorations (AGS) that had no "extension for prevention". The CompS/C restorations were also compared with the traditional (unsealed) amalgam restorations (AGU) with the "extension for prevention" outline form. Caries progress, as determined by standardized radiographs, revealed that after 5 years caries remained arrested under the CompS/C restorations; the marginal integrity was similar for the CompS/C and the AGS groups, and exhibited highly significant superiority to the AGU restorations (Chi square, P less than = 0.00004). Complete sealant retention over the amalgam restorations (AGS group) was less than over the composite restorations (CompS/C), and conversely, partial sealant retention was higher for the AGS group. Sealants also appeared to protect the posterior composite restorations against wear.

Adolescent↗

PubMed1991

Evidence for involvement of both D1 and D2 receptors in maintaining cocaine self-administration.

Rats trained to self-administer cocaine (0.75 mg/kg/infusion) on an FR-5 schedule were treated with selective D1 or D2 antagonists. A69045, a D1 antagonist with no appreciable affinity for 5-HT receptors increased cocaine self-administration to 147, 172 and 167% of baseline at doses of 2.5, 5.0 or 10.0 mumol/kg, SC respectively. SCH-23390 (0.007, 0.015 and 0.030 mumol/kg, SC) increased self-administration to 116, 147 and 165% of baseline, respectively. Both D1 antagonists decreased responding in some animals at the highest dose tested. The D2 antagonist YM-09151-2 showed a similar profile, increasing cocaine self-administration at 0.01 and 0.016 mumol/kg, SC and suppressing responding by most animals at the dose of 0.03 mumol/kg, SC. These data give further support to the hypothesis that both D1 and D2 receptors are involved in maintaining cocaine self-administration.

Animals↗

PubMed1991

The radiological features of phylloides tumour of the breast with clinico-pathological correlation.

The mammograms of 13 patients with phylloides tumour of the breast are reviewed and the results correlated with clinical and histological features. Three patients had recurrent tumours. There is a strong association between phylloides tumour and fibroadenoma. Many of the tumours are radiologically indistinguishable from fibroadenomata and it is not possible to predict tumour behaviour on the basis of clinical and radiological features alone.

Adult↗

PubMed1991

Selenium absorption and retention by very-low-birth-weight infants: studies with the extrinsic stable isotope tag 74Se.

Measurements of dietary selenium absorption and retention were obtained after administration of a single dose of the extrinsic stable isotope tag 74Se in 20 appropriate for gestational age premature infants with birth weights between 720 and 1,630 g and gestational ages between 26 and 33 weeks. Infants were assigned randomly to receive a standard premature formula (1.34 microgram of Se/dl) or a selenium-supplemented version of that formula (2.03 micrograms of Se/dl). Each study consisted of one feeding that had been extrinsically labeled with 74Se (1.03 microgram/kg) and a timed stool and urine collection. The percent 74Se absorption was 91.2 +/- 5.4% (mean +/- SD) from the standard formula and 86.2 +/- 3.0% from the selenium-supplemented formula (p less than 0.05), but the percent of the absorbed 74Se retained was not different, i.e., 96.6 +/- 2.1% and 95.0 +/- 2.8%, respectively. The percent net absorption and net retention were also not different between the standard and selenium-supplemented formulas; net absorption was 72.7 +/- 18.1% vs. 67.8 +/- 18.8% and net retention was 57.2 +/- 17.6% vs. 53.3 +/- 20.2%, respectively. The percent 74Se absorption and true selenium absorption were significantly correlated with the percent net selenium absorption and net selenium absorption, respectively. We conclude that an extrinsically administered dose of 74Se can be used to study selenium nutrition in growing premature infants.

Birth Weight↗

PubMed1991

Ultraconservative sealed restorations: three-year results.

The overall objective of this clinical study was to determine the feasibility of using a sealed composite restoration to arrest caries without the removal of the carious lesion and without the traditional cavity preparation. The minimal tooth preparation (a bevel in enamel) usually did not require any anesthetic injection and conserved tooth structure. These ultraconservative sealed composite restorations placed over caries (CompS/C) have been compared with ultraconservative sealed amalgam restorations (AGS) and with the traditional outline form (unsealed) amalgam restorations (AGU). This clinical study has shown that: (1) caries can be arrested by the CompS/C restoration for a period of three years; (2) the marginal integrity of the AGS restorations showed a definite trend toward improvement as compared to the AGU restorations; and (3) complete sealant retention over posterior restorations was similar in both the CompS/C and the AGS groups during the first two years; however, at Year 3 complete sealant retention was 16 percent higher in the CompS/C than in the AGS group.

Adolescent↗

PubMed1991

Use of electron microscopy in examination of faeces and rectal and jejunal biopsy specimens.

The stools and rectal biopsy specimens of 44 patients with AIDS and diarrhoea were examined by culture, light microscopy, and electron microscopy. In 13 patients examination of rectal biopsy material and faecal samples showed no pathogen, but in two of these, microsporidiosis was found by electron microscopical examination of jejunal biopsy specimens. This organism was also identified electron microscopically in one of the further five jejunal biopsy samples taken from patients with a known cause of diarrhoea. Blastocystis hominis infection was identified electron microscopically in six patients, all of whom had cryptosporidiosis additionally seen by light microscopy. Four of these six patients remained well for long periods, with only moderate diarrhoea, and follow up showed no evidence of blastocystis infection. In only four of 11 patients found to have cryptosporidium in their stools at light microscopy were organisms found at electron microscopy. Viral inclusions were only identified at electron microscopy in one of 10 patients with an opportunistic viral infection seen at light microscopy (cytomegalovirus n = 7, herpes simplex virus n = 3). No additional viral pathogens were detected in either stools or rectal biopsy material by electron microscopy. It is concluded that routine electron microscopic examination of stool samples or rectal biopsy material taken from patients with AIDS and diarrhoea is unnecessary and does not increase the yield of potential pathogens compared with standard microbiological techniques and histology.

Acquired Immunodeficiency Syndrome↗

PubMed1991

Influence of zeranol and breed on growth, composition of gain, and plasma hormone concentrations.

Seven Angus and six Brangus steers averaging 225 and 245 kg, respectively, were assigned randomly to zeranol (36 mg) implant (I) and no implant (NI) treatments. Steers had ad libitum access to a corn silage diet plus .68 kg of a soybean meal-based supplement fed daily. Steers were bled via jugular catheters on d 0, 28, 56, and 84 at 15-min intervals for 4 h before and 4 h after feeding. Concentrations of growth hormone (GH), insulin (INS), triiodothyronine (T3), thyroxine (T4), and glucose were determined. Whole-body protein and fat contents were monitored. A breed x I interaction (for d 56 to 84 and d 0 to 84) was observed for ADG (P less than .05 and P less than .07, respectively), feed conversion (P less than .05 and P less than .07, respectively), and protein deposition (for d 0 to 29 and d 0 to 84; P less than .07 and P less than .05, respectively). These interactions were attributed to a greater response to I by Angus than by Brangus steers. A feeding x period interaction (P less than .10) was observed for mean GH concentration, and INS, T4, and T3 concentrations were higher (P less than .05) during the 4-h postfeeding period than during the 4-h prefeeding period. The implant increased (P less than .08) mean GH concentration but did not alter the frequency, duration, or amplitude of plasma GH peaks. Steers that were implanted had lower (P less than .05) plasma T3. Brangus steers had lower (P less than .05) plasma glucose, T3, and T4 concentrations than Angus steers. Results indicate that growth factors beyond those measured are responsible for the anabolic response to zeranol.

Adipose Tissue↗

PubMed1991

Evaluation of dairy food processing wash water solids as a protein source: I. Forage intake, animal performance, ruminal fermentation, and site of digestion in heifers fed medium-quality hay.

Twelve ruminally, duodenally, and ileally cannulated (average initial BW 313 +/- 20 kg) and 27 intact Hereford heifers (average initial BW 256 +/- 17 kg) were used in two experiments to evaluate dairy food wash water solids (WWS) as a protein source in medium-quality hay diets. Heifers received a basal diet of orchardgrass hay (7.4% CP) and were assigned to one of three supplement treatments: control (C; .9% CP), WWS (18.8% CP)-, and soybean meal (SBM; 19.1% CP)-based supplements (fed at 1.5 kg of DM/d). Supplements were formulated to have similar ME concentrations. Ruminal ammonia concentrations were greater (P less than .10) for WWS- and SBM-supplemented heifers than for C heifers at most sampling times. Moreover, WWS and SBM increased (P less than .10) total VFA (mM) and acetate (mol/100 mol) and lowered propionate (mol/100 mol) at several sampling times. Ruminal fluid volume (liters) was unchanged (P greater than .10) by treatment; however, fluid dilution and flow rate (liters/h) were less (P less than .10) in C heifers than in heifers fed SBM or WWS supplements. Wash water solids and SBM supplementation increased (P less than .10) OM, NDF, and ADF digestibilities compared with C heifers. Feeding WWS and SBM supplements increased BW at 84 d (P less than .10) compared with C-supplemented heifers. Forage intake at 54 and 84 d by heifers supplemented with SBM or WWS was greater (P less than .10) than by C heifers. Control-supplemented heifers had the least, WWS intermediate, and SBM the greatest ADG at 84 d (P less than .10; .14 vs .35 vs .48 kg/d, respectively). These data indicate that WWS may be used as a protein source without serious adverse effects in heifers consuming medium-quality hay for 84 d.

Ammonia↗

PubMed1991

Evaluation of dairy food processing wash water solids as a protein source: II. Microbial protein synthesis, duodenal nitrogen flow, and small intestinal amino acid disappearance.

Twelve ruminally, duodenally, and ileally-cannulated Hereford heifers (average initial BW 313 +/- 20 kg) were used in a replicated experiment to evaluate dairy food processing wash water solids (WWS) as a protein source. Heifers were fed 2.8 kg of chopped (7.6 cm) hay and one of three supplements (1.5 kg/d, DM basis). Supplements were formulated to be similar in energy and contained 1.0 (control), 23.2 (WWS), and 21.6% (soybean meal; SBM) CP on an OM basis. Total N and nonammonia N entering the duodenum (g/d) were greater (P less than .10) for heifers fed WWS and SBM supplements than for controls. Bacterial N flow (g/d) at the duodenum was less (P less than .10) for controls (43.9) than for WWS- (63.9) and SBM- (69.9) supplemented heifers. Feed escape N (g/d) was greater (P less than .10) for WWS-fed heifers than for those fed SBM (32.1 vs 20.7 g/d, respectively). Total tract N digestion (g/d) was greatest (P less than .10) for SBM, intermediate for WWS, and least for control heifers. Microbial protein synthesis (g/kg of OM intake) was enhanced (P less than .10) by WWS and SBM supplementation, but efficiency of synthesis (g/kg of OM fermented) did not differ among treatments. Essential amino acid (AA) disappearance in the small intestine (g/d) was less (P less than .10) for control than for the other two treatments. Nonessential AA disappearance was greatest (P less than .10) for the WWS and least (P less than .10) for the control treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acids↗

PubMed1991

Evaluation of dairy food processing wash water solids as a protein source: III. Nitrogen utilization by heifers fed medium-concentrate diets.

Eight multicannulated heifers (average BW 415 +/- 34 kg) were used in a replicated 4 x 4 Latin square to evaluate fluid milk processing wash water solids (WWS) as a dietary N source. Heifers were fed corn/cottonseed hull-based diets containing soybean meal (control, 0% WWS N) or WWS replacing soybean meal at 33, 67, or 100% of supplemental dietary N. Total tract and ruminal DM and OM digestibilities decreased linearly or cubically (P less than .05) as dietary WWS N increased. Total ruminal VFA concentration (P less than .05) and propionic acid molar proportion (P less than .10) were greater in heifers fed 0 vs 100% WWS N. Heifers fed 0% WWS N had the greatest (P less than .05) ruminal ammonia concentration at all sampling times. Dietary WWS did not affect (P greater than .10) ruminal pH, fluid dilution rate, fluid flow, fluid volume, or turnover time. Total tract N digestibility decreased quadratically (P less than .10) with increasing WWS N in the diet. Supplemental WWS N did not affect (P greater than .10) flow of duodenal ammonia N or bacterial N, or efficiency of microbial N synthesis. Diets containing WWS N resulted in a cubic increase (P less than .10) in duodenal flow of essential amino acids compared with 0% WWS N; however, there were no differences in small intestinal amino acid disappearance. Data indicate that WWS can replace 33% of the soybean meal N in a corn/cottonseed hull-based diet without decreasing ruminal fermentation, fluid digesta kinetics, microbial efficiency, or small intestinal amino acid utilization.

Amino Acids↗

PubMed1991

A comparison of perceived self among drug addicts and nonaddicts.

The Adjective Check List was employed to compare the self-concepts of 41 male drug addicts, 44 male nonaddicted technical school students, and 37 male nonaddicted psychiatric patients. A large number of significant differences were found. Three scoring systems were used that yielded a total of 23 scales. There were nine scales on which the addict group was different from the normal group but the psychiatric nonaddict group was not. These nine scales are of particular interest since they represented traits that differentiated addicts from normals. These traits appear to be related to addiction rather than general maladjustment. Implications for treatment are discussed.

Adult↗

PubMed1991

Sealed restorations: 4-year results.

The overall objective of this clinical study was to determine the feasibility of using a sealed composite restoration to arrest caries. This objective was to be achieved using minimal tooth preparation for Class I lesions, without the traditional Class I cavity preparation and without the removal of the carious lesion. The minimal tooth preparation consisted of no [corrected] removal of the carious lesion, bevel in enamel only, and usually not requiring any anesthetic injection. These ultra-conservative sealed composite restorations placed over caries (CompS/C) were compared with ultra-conservative sealed amalgam restorations (AGS) and with the traditional (unsealed) amalgam restorations (AGU). This study showed that: 1) caries is arrested under the CompS/C restoration for a period of 4 years; 2) sealant retention is similar in both the CompS/C and the AGS groups; 3) the marginal integrity of the AGS restorations is markedly superior to that of the AGU restorations; and 4) sealant appears to prevent wear of posterior composite restorations.

Adolescent↗

PubMed1990

The D2 agonist quinpirole potentiates the discriminative stimulus effects of the D1 agonist SKF 38393.

Although there are two dopamine (DA) receptors (D1 and D2) in the brain, the functional role, particularly of D1 receptors, has remained unclear. Recent research has suggested that D1 and D2 receptors interact synergistically in the generation of certain D2 agonist-induced motor responses. On the other hand, an antagonistic interaction between the receptors has been reported for D1 agonist-induced perioral movements. The purpose of the present experiment was to characterize further the interaction between D1 and D2 receptors using a drug discrimination paradigm, a behavioral paradigm that is sensitive and selective for D1 and D2 agonist and antagonist activity. Rats (N = 8) were trained to discriminate the D1 agonist SKF 38393 (SKF; 10 mg/kg, IP, 30 minutes presession) from saline (1.0 ml/kg, IP, 30 minutes presession) in a 2-lever, food-reinforced-drug discrimination paradigm, SKF (0.2-12.8 mg/kg) produced a dose-related increase in SKF-appropriate responding (maximum 87.5% at 12.8 mg/kg). The D2 agonist quinpirole (QUIN; 0.012-0.1 mg/kg, IP, 10 minutes presession) given alone did not substitute for SKF (maximum 37% SKF-appropriate responding at 0.05 mg/kg). QUIN (0.012 or 0.025 mg/kg) in combination with SKF significantly (p less than 0.05) shifted the SKF dose-response function to the left, suggesting that stimulation of D2 receptors can potentiate a behavioral effect mediated by D1 receptors. Furthermore, when taken together with previous findings that SKF failed to potentiate the discriminative stimulus effects of QUIN, the present results suggest that the nature of D1/D2 receptor interactions depends not only upon the behavior under investigation but also upon the receptor action that the behavior reflects.

2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-ben↗

PubMed1990

Preliminary characterization of pyruvate uptake by one-cell ovine embryos.

Pyruvate uptake was measured by a noninvasive method on a total of 59 individual one-cell ovine embryos. Uptake was measured over a 4-h period in Whitten's medium containing 1.0 mM glucose and either 0.0 mM, 0.33 mM, 0.67 mM or 1.0 mM sodium pyruvate. Glucose uptake was also assessed to determine the effect of altering pyruvate concentration on glucose uptake. Embryos incubated in medium containing 1.0 mM or 0.67 mM pyruvate showed average uptake values of 20.36 and 5.00 pmoles per embryo per 4 h, respectively. In contrast, when pyruvate concentrations were 0.0 mM and 0.33 mM, the embryos released an average of 24.60 and 10.40 pmoles pyruvate per embryo per 4 h. Uptake or release of pyruvate was found to vary linearly with concentration level. Increasing pyruvate concentration resulted in a significant decrease in glucose uptake.

Journal Article↗

PubMed1990

Evaluation of the interaction between D1 and D2 receptors in a drug discrimination paradigm.

Recent research has suggested that there is a synergistic interaction between D1 and D2 dopamine (DA) receptors and that D1 stimulation by endogenous DA is necessary for the expression of some D2-mediated behavioral effects. The purpose of the present experiment was to examine further the interactions between D1 and D2 receptors using drug discrimination (DD), a behavioral paradigm that is sensitive and selective for D1 and D2 agonist and antagonist activity. Two groups of male Sprague-Dawley rats (N = 8/group) were trained to discriminate the D2 agonist quinpirole (QUIN; either 0.05 or 0.012 mg/kg, ip, 10 min pre-session) from saline (1.0 ml/kg, ip, 10 min pre-session) in a two-lever, food-reinforced DD paradigm. QUIN (0.0015-0.1 mg/kg) produced a dose-related increase in QUIN-appropriate responding in both groups of rats. The D1 agonist SKF 38393 (SKF; 6.4-12.8 mg/kg, ip) given alone did not substitute for QUIN in either of the two training dose groups. The administration of SKF 30 min before QUIN had no effect on the QUIN dose-response function in either group of rats. These results indicate that stimulation of D1 receptors failed to potentiate a behavioral effect mediated by D2 receptors. The D1 antagonist SCH 23390 (SCH; 0.0015-0.05 mg/kg, ip) partially substituted for QUIN in the group trained with the 0.05 dose of QUIN, and to a larger extent in the group trained with the 0.012 dose of QUIN. SCH did not alter the effect of the training dose of QUIN except at a dose high enough to virtually eliminate lever pressing in the group trained to discriminate the high dose of QUIN. The failure of SCH to block QUIN suggests that D1 receptor stimulation by endogenous DA is not necessary for this D2 effect to be expressed. These results may be accounted for by assuming a presynaptic site of action for QUIN in the QUIN discrimination. Further, they demonstrate that the interaction between D1 and D2 receptors cannot be simply characterized as synergistic.

2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-ben↗