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Biomedical subjects

B Woods

Publications and source records attributed to B Woods.

33 records · Page 2Linked to original sources

The effect of porta-systemic shunting on liver, brain and kidney zinc concentrations in the rat.

Patients with alcoholic cirrhosis have subnormal liver zinc concentrations, and excessive urinary zinc excretion. It has been suggested that diversion of dietary zinc into the systemic circulation through porta-systemic shunts may be a major factor influencing the organ distribution of zinc in these patients. To test this hypothesis, we randomized Sprague-Dawley rats into a sham-operated group, and a group subjected to partial portal-vein occlusion (PPVO), which induces the formation of extensive porta-systemic collaterals. Three months after the operation, liver, brain and kidney zinc concentrations were measured in 8 sham-operated and 8 PPVO rats. Mean liver zinc concentrations were significantly higher in the PPVO group when compared to sham-operated controls (P less than 0.05). Brain and kidney zinc concentrations were similar in the 2 groups. This short-term study indicates that liver zinc concentrations are maintained and even increased in rats with porta-systemic shunting, and that diversion of portal blood into the systemic circulation is not a major cause of the low liver zinc concentration observed in alcoholic cirrhosis.

Animals↗

Toxic woods.

Eighty-three cases of dermatitis caused by wood or sawdust have been seen at St John's Hospital for Dieases of the Skin, London, in the last 20 years. The clinical details and results of patch tests are reported. The literature on dermatitis, mucosal irritation, asthma and other toxic effects of woods of some 300 botanical species is reviewed at length, with an index of scientific, trade and vernacular names, chemical formulae of the known sensitizing substances, and a table of the 28 toxic woods most often encountered. Pathogenesis, diagnosis and prophylaxis are discussed.

Adolescent↗

Protein catabolic rate in patients on continuous peritoneal dialysis. A multivariate predictive model.

Protein catabolic rate (PCR) and PCR normalized to standard weight (PCRN) are important indices of nutrition in patients on continuous peritoneal dialysis. The purpose of this study was to test whether urea clearance is among the predictors of PCR and PCRN in a multivariate analysis. Stepwise logistic regression was used to develop separate models for low PCR and low PCRN on a set of 143 urea kinetic studies in 92 patients on continuous peritoneal dialysis. The regression models were tested on an independent sample of 189 urea kinetic studies in 102 patients on continuous peritoneal dialysis by deriving the area under a receiver operating characteristic curve. In the derivation set, low serum urea, high serum creatinine, low urine and dialysate drain volumes, and low body surface area were identified as predictors of PCR < or = 50 g daily. The area under the receiver operating characteristic curve in the validation set was 0.930 (95% confidence interval: 0.915-0.945). Low serum urea, male gender, high body mass index and low urea fractional clearance (KT/V) were predictors of PCRN < or = 0.80 g/kg daily. The receiver operating characteristic area for this model was 0.948 (95% confidence interval: 0.926-0.970). Logistic regression analysis was repeated twice after adding urea nitrogen excretion normalized to standard weight (UNEN) as a candidate variable. This process identified low UNEN, male gender, and obesity as the predictors of low PCRN, and low UNEN, male gender, low urine volume, low drain volume normalized by body water, and high serum albumin as predictors of low KT/V urea. The authors conclude that PCR and PCRN can be predicted by models that incorporate serum azotemic indices, body size and composition, and direct or indirect measurements of urea clearance. Small body size and lean body composition predict low PCR but high PCRN values. Both PCRN and KT/V urea are predicted by UNEN. Multivariate analysis cannot, therefore, rule out the hypothesis that PCRN and KT/V are linked mathematically.

Body Weight↗

Effects of norepinephrine on lung liquid production by in vitro lungs from fetal guinea pigs.

Lungs from near-term fetal guinea pigs (61 +/- 2 days of gestation) were supported in vitro for 3 h; lung liquid production was monitored by a dye dilution method. Untreated control preparations produced fluid at 1.38 +/- 0.30 mL x kg(-1) body weight x h(-1), with no significant change (ANOVA; regression analysis); those given 1.24 x 10(-9) or 1.24 x 10(-8) M norepinephrine during the middle hour showed no significant change, but those given concentrations between 5.24 x 10(-8) and 1.24 x 10(-5) M all showed significant reductions or fluid reabsorption (based on 42 fetuses). The responses showed a linear relationship with the log concentration (r = 0.97). They appeared to involve alpha-adrenoreceptors, since responses to 10(-7) M norepinephrine were unaffected by 10(-6) M propranolol, but those to 10(-7) and 1.24 x 10(-6) M norepinephrine were abolished by 10(-6) and 1.78 x 10(-5) M phentolamine, respectively (based on 48 fetuses). Activation was through alpha2-adrenoreceptors, since responses to 10(-7) and 10(-5) M norepinephrine were abolished by 10(-4) M yohimbine, but not by 10(-5) M prazosin (based on 60 fetuses). The results show that norepinephrine is able to reduce lung liquid production when at plasma levels present at birth, and that it can produce reabsorption; unlike epinephrine, there was no reduction in responses at high concentrations. This work reintroduces a neglected factor, norepinephrine, into possible controls of lung liquid reabsorption, and opens up the potential for neural controls.

Adrenergic alpha-1 Receptor Antagonists↗

Isoniazid-related hepatitis.

Conclusive evidence of isoniazid (INH)-related hepatotoxicity ranging from asymptomatic elevation of liver enzymes to fulminant hepatic failure resulting in liver transplantation and/or death has been firmly established. Anticipation of the widespread usage of INH in the prevention and treatment of tuberculosis is expected due to the recent increasing incidence of tuberculosis. The aim of this article is to review the current concepts of pathogenesis, histopathology, risk factors and clinical features of INH-related hepatitis, emphasizing the need for vigilance.

Antitubercular Agents↗

Choriocarcinoma metastatic to the lung. A cytologic study with identification of human choriogonadotropin with an immunoperoxidase technique.

A case of choriocarcinoma metastatic to the lung following a previous hydatidiform mole is presented. It was possible to make definitive identification of trophoblastic elements on a needle aspiration biopsy using an immunoperoxidase staining technique, thus avoiding diagnostic thoracotomy prior to therapeutic intervention. A method of immunoperoxidase staining of previously fixed and Papanicolaou-stained needle aspiration biopsy specimens is also described, and other uses of the immunoperoxidase technique on needle biopsy specimens are discussed.

Adult↗