Therapy for good risk germ cell tumors

BACKGROUND: Duodenal mucosal biopsies are routinely taken for diagnosis in children with complaints of the upper gastrointestinal tract. Surprisingly, little is known about the usefulness of proximal duodenal versus distal duodenal biopsies for routine diagnostic purposes. This study evaluated the comparability of proximal and distal duodenal biopsies with respect to mucosal morphology as well as glycohydrolase expression as an indicator of intestinal epithelial function. METHODS: Specimens obtained in duodenal endoscopic biopsies from 64 children, ranging in age from 3 months to 18 years with normal or affected mucosa, were studied. Biopsies were performed in anatomically defined regions in the bulbus duodeni (the very proximal part of the duodenum) and distally of the papilla of Vater (distal of the pancreatic duct). Biopsy specimens were paraformaldehyde-fixed for histologic examination and immunohistochemical evaluation or were homogenized to isolate RNA. Crypt/villus morphology was assessed as is routinely determined by pathologists. In addition, several aspects of lactase and sucrase-isomaltase expression as paradigms of intestinal brush border enzymes were assessed: localization at the cellular level, semiquantitative immunohistochemistry, and quantitative measurement of the messenger RNA levels of the respective brush border glycohydrolases. RESULTS: As anticipated, there was a wide interpatient variation in mucosal morphology and expression of lactase and sucrase-isomaltase. Nonetheless, the consistent finding was that in each patient, measurements of morphology and lactase and sucrase-isomaltase gene expression were very similar between samples obtained in the proximal and distal biopsies. CONCLUSIONS: Biopsies performed in either location in the duodenum are equally suitable for diagnostic workup of patients suspected of mucosal abnormalities affecting morphology or small intestinal brush border glycohydrolase activities.     

Proteome in perspective

This review describes briefly proteome science. It explains why proteome science or proteomics emerged only recently and why a shift from genomics to proteomics is occurring. This review further illustrates that proteomics can unravel new domains in nature's complexity. Finally, it demonstrates that proteomics is offering new tools for the study of complex biological or medical problems.     

Specific substrates for spectrophotometric determination of penicillin acylase activity

Penicillin acylase substrates suitable for colorimetric determination of the enzyme activity have been tested in this study. The kinetic parameters (Km and kcat) have been elucidated for the following nine substrates: six phenylacetic acid derivatives (p-nitroanilide, p-nitrophenyl ester, p-nitro-m-carboxyanilide, p-nitro-o-carboxyanilide, p-nitro-o-hydroxyanilide, m-nitro-p-carboxyanilide), two D-phenylglycine derivatives (p-nitroanilide, p-nitro-m-carboxyanilide), and also p-nitrophenyl ester of acetic acid (p-nitrophenyl acetate). With the exception of p-nitrophenyl acetate, all the compounds studied are highly specific chromogenic substrates for penicillin acylase, but their reactivity is very variable and kcat/Km values are in a range from 0.8.10(4) to 5.10(6) M(-1).sec(-1).     

AGN 191976: a novel thromboxane A2-mimetic with ocular hypotensive properties

The possible subdivision of thromboxane A2-sensitive (TP) receptors is currently a controversial subject. We report herein on a novel thromboxane A2 mimetic, AGN 191976, which has almost identical pharmacological activity to the well-characterized prostaglandin H2/thromboxane A2 (PGH2/TxA2) mimetic U-46619, but its effects on intraocular pressure are quite distinct from U-46619. Prostanoid receptor activity was determined in vitro using different smooth muscle assays and platelets. Intraocular pressure was measured tonometrically in ocular normotensive Beagle dogs and Cynomolgus monkeys. Conjunctival microvascular permeability was determined in guinea pigs. Despite closely resembling U-46619 as a potent and selective TP receptor agonist, AGN 191976 was a potent ocular hypotensive in dogs and monkeys whereas U-46619 did not lower IOP in either species. The ocular hypotensive effect of AGN 191976 in dogs was attenuated by pretreatment with the TP receptor antagonist SQ 29548. Thus, the ocular hypotensive effects of AGN 191976 are consistent with TP receptor stimulation. Both TxA2-mimetics caused plasma leakage in the guinea pig conjunctiva. The disparate activities of U-46619 and AGN 191976 in our studies suggest the existence of heterogeneous populations of TP-receptors in the eye.     

Insulin-like growth factors in plasma and afferent mammary lymph of lactating cows deprived of feed or treated with bovine somatotropin

The galactopoietic actions of bovine somatotropin are both direct and indirect. Indirect actions are apparently mediated by the insulin-like growth factor (IGF) system. The objective of this study was to compare systemic (plasma) versus local (lymph) concentrations of IGF. Afferent mammary lymph most nearly represents the extracellular fluid that is bathing mammary tissue. Catheters were surgically implanted in the jugular vein and the superficial afferent mammary lymph vessels of four lactating cows. A crossover design was utilized to evaluate the effects of bovine somatotropin (bST). After 2 d of basal sampling, either bST (40 mg/d) or excipient was administered daily for 5 d. After the conclusion of the bST study, a second study was conducted in which cows were deprived of feed for 36 h. Blood and lymph were simultaneously sampled at least every 6 h throughout both studies. Milk yield was increased by bST, and concentrations of IGF-I were increased in plasma and lymph. The relationship between plasma and lymph concentrations for IGF-II, bST, insulin, glucose, urea nitrogen, and nonesterified fatty acids were similar during bST treatment. Milk yield was reduced 76% by 36 h of feed deprivation. Feed deprivation also caused a reduction of IGF-I in plasma, but concentrations of IGF-I in lymph were not altered. In contrast, changes in IGF-II, bST, insulin, glucose, urea nitrogen, and nonesterified fatty acids that were caused by feed deprivation followed similar patterns in plasma and lymph. Clearly, if IGF-I mediates the mammary actions of bST, then concentrations of IGF-I in plasma correlate with milk yield responses as well as, if not better than, concentrations in lymph.     

Determination of dimethindene in human tears by high-performance liquid chromatography

A high-performance liquid chromatographic method is described for the determination of dimethindene in human tears. The tear samples were diluted in a 0.01 M hydrochloric acid-n-propanol mixture to prevent the irreversible adsorption of dimethindene. The diluted samples were directly injected into the chromatographic system to avoid sample pretreatment. The validation data demonstrate that the method is specific, precise and accurate within the calibration range of 12 to 1000 ng/ml dimethindene free base.     

Attenuation of the polypeptide 7B2, prohormone convertase PC2, and vasopressin in the hypothalamus of some Prader-Willi patients: indications for a processing defect

7B2 is a neuroendocrine chaperone interacting with the prohormone convertase PC2 in the regulated secretory pathway. Its gene is located near the Prader-Willi syndrome (PWS) region on chromosome 15. In a previous study we were able to show 7B2 immunoreactivity in the supraoptic nucleus (SON) or the paraventricular nucleus (PVN) in only three of five PWS patients. Here we report that in contrast with five other PWS patients, the neurons in the hypothalamic SON and PVN of the two 7B2-immunonegative PWS patients also failed to show any reaction using two antibodies directed against processed vasopressin (VP). On the other hand, even these two cases reacted normally with five antibodies that recognize different parts of the VP precursor. This finding pointed to a processing defect. Indeed, the same patients had no PC2 immunoreactivity in the SON or PVN, whereas PC1 immunoreactivity was only slightly diminished. In conclusion, in the VP neurons of two PWS patients, greatly reduced amounts of 7B2 and PC2 are present, resulting in diminished VP precursor processing.     

trans-encapsidation of a poliovirus replicon by different picornavirus capsid proteins

A trans-encapsidation assay was established to study the specificity of picornavirus RNA encapsidation. A poliovirus replicon with the luciferase gene replacing the capsid protein-coding region was coexpressed in transfected HeLa cells with capsid proteins from homologous or heterologous virus. Successful trans-encapsidation resulted in assembly and production of virions whose replication, upon subsequent infection of HeLa cells, was accompanied by expression of luciferase activity. The amount of luciferase activity was proportional to the amount of trans-encapsidated virus produced from the cotransfection. When poliovirus capsid proteins were supplied in trans, >2 x 10(6) infectious particles/ml were produced. When coxsackievirus B3, human rhinovirus 14, mengovirus, or hepatitis A virus (HAV) capsid proteins were supplied in trans, all but HAV showed some encapsidation of the replicon. The overall encapsidation efficiency of the replicon RNA by heterologous capsid proteins was significantly lower than when poliovirus capsid was used. trans-encapsidated particles could be completely neutralized with specific antisera against each of the donor virus capsids. The results indicate that encapsidation is regulated by specific viral nucleic acid and protein sequences.