Activated N-ras gene induces neuronal differentiation of PC12 rat pheochromocytoma cells

Activated mouse N-ras gene transfected into PC12 rat pheochromocytoma cells suppressed proliferation and promoted neuronal differentiation. Normal mouse N-ras in a LTR-containing vector caused differentiation with a reduced efficiency, but normal N-ras in a vector lacking LTR sequences failed to alter the PC12 phenotype. Cultures of NGF-resistant PC12 variant subline U7 also showed outgrowth of neurites and cessation of cell division following transfection with the mutated ras gene. The present findings suggest that ras genes can, in certain cells, play a role in promoting differentiation and suppressing proliferation, in contrast to their established oncogenic neoplasia-promoting activity in other cells.

Bioartificial liver: implanted artificial cells microencapsulated living hepatocytes increases survival of liver failure rats

Suspension of living hepatocytes were microencapsulated inside 300 micron mean diameter alginate artificial cells. The galactosamine fulminant hepatic failure rat model was used. 48 hours after the injection of galactosamine, grade II coma hepatic failure rats were divided into pairs. One of the pair was randomly chosen for the control group, and the other for the treated group. Each rat in the control group received one peritoneal injection of microcapsules containing no hepatocytes. Each rat in the treated group received one peritoneal injection of microcapsules containing hepatocytes. The survival of the treated group is significantly higher than the control group.

Nonbronchoscopic bronchoalveolar lavage for the diagnosis for Pneumocystis carinii pneumonia in the acquired immunodeficiency syndrome

We compared conventional bronchoscopic transbronchial biopsy (TBB) and bronchoalveolar lavage (BAL) with non-bronchoscopic bronchoalveolar lavage (NB-BAL) in nine patients with acquired immunodeficiency syndrome (AIDS) and bilateral lung infiltrates. NB-BAL was carried out with a control-tipped reusable catheter. In each patient, bronchoscopic procedures were performed in the right lung, followed immediately by NB-BAL in the left lung. The specimens obtained by NB-BAL confirmed the presence of P carinii pneumonia in seven of eight patients in whom the diagnosis was established by TBB or BAL. Viral cultures of NB-BAL specimens yielded cytomegalovirus (CMV) in four of five subjects with evidence of CMV via bronchoscopic technique, including two instances in which CMV was not detected by BAL. Complications were limited to right-sided pneumothorax attributable to TBB. Accuracy of NB-BAL appears to be comparable to that of conventional bronchoscopic approaches in the diagnosis of AIDS-related pulmonary infection with P carinii or CMV. NB-BAL may be a safer and more economical alternative to TBB and BAL in the diagnosis of pulmonary opportunistic infections.

Reductive amination of 3-ketoanguidin and antitumor activity of the products

Amine-containing trichothecanes were prepared by reductive aminations of 3-ketoanguidin. In in vivo tests against P388 leukemia, most of them showed an improved activity compared to anguidin though their potency was decreased. 3-Ketoanguidin also produced some unexpected structures: oxazoline 5, dioxalane 7, and alpha-amino nitrile 13.

Bicyclic and tricyclic analogues of anthramycin

As analogues of pyrrolo[2,1-c][1,4]benzodiazepine antitumor antibiotics, such as anthramycin and tomaymycin, several benzo[1,4]diazepine imines and carbinolamine ethers were prepared and tested in vivo against P388 leukemia. Two different synthetic approaches, namely, a reduction of an aromatic nitro group with a concomitant cyclization and a reduction of a lactam, were employed to generate an imine or a carbinolamine moiety. Bicyclic analogues 6a', 6f, and 6g were found to be active, indicating that the pyrroline ring of anthramycin is not an absolute necessity for the antitumor activity. Compound 6g, 3,4-dihydro-9-hydroxy-4-propargyl-5H-1,4-benzodiazepin-5-one, was at least as active as neothramycin although it was 5 times less potent. Among the tricyclic analogues, compounds 5, 7a, and 8b were active against P388 leukemia, and they generally appear to be more potent than bicyclic analogues.

Congenital facial anomalies among 4- through 7-year-olds: psychological effects and surgical decisions

In children with congenital facial anomalies, body image and emotional indicators correlated with the timing and number of operations, rather than with the severity of the deformity. These data suggest that surgery should be performed at the earliest age possible and in the fewest number of stages.

N.M.R. studies of aldonolactones. The 80-MHz proton N.M.R. and 20-MHz proton-coupled 13C N.M.R. of D-Arabinono-1,4-lactone in D2O solutions

The 80-MHz proton n.m.r. spectrum of D-arabinono-1,4-lactone in D2O has been simulated and the results utilized in the assignment of the 20-MHz proton-coupled 13C n.m.r. spectrum. Two-and three-bond carbon-proton coupling constants have been derived from computer simulations and are discussed in terms of the dihedral angles in the preferred conformation.

The architecture of the animal fatty acid synthetase complex. IV. Mapping of active centers and model for the mechanism of action

The fatty acid synthetase of animal tissue consists of two subunits, each containing seven catalytic centers and an acyl carrier site. Proteolytic cleavage patterns indicate that the subunit is arranged into three major domains, I, II, and III. Domain I contains the NH2-terminal end of the polypeptide and the catalytic sites of beta-ketoacyl synthetase (condensing enzyme) and the acetyl-and malonyl-transacylases. This domain, therefore, functions as a site for acetyl and malonyl substrate entry into the process of fatty acid synthesis and acts in part as the site of carbon-carbon condensation, resulting in chain elongation. Domain II is the medial domain and contains the beta-ketoacyl and enoyl reductases, probably the dehydratase, and the 4'-phosphopantetheine prosthetic group of the acyl carrier protein site. Domain II, therefore, is designated as the reduction domain where the keto carbon is reduced to methylene carbon by sequential processes of reduction, dehydration, and reduction again. Throughout these processes, the acyl group is attached to the pantetheine-SH of the acyl carrier protein. The latter site is distal to the cysteine-SH of the beta-ketoacyl synthetase, constitutes the 15000-dalton polypeptide at the COOH-terminal end of Domain II, and connects to Domain III. When the growing chain reaches C16 carbon length, the fatty acyl group is released by the thioesterase activity, which is contained in Domain III. A functional model is proposed based on the aforementioned results and the recent evidence that the synthetase subunits are arranged in a head-to-tail fashion, such that the pantetheine-SH of the acyl carrier protein of one subunit and the cysteine-SH of the beta-ketoacyl synthetase of the second subunit are juxtaposed. In this model, a palmitate synthesizing site contains Domain I of one subunit and Domains II and III of the second subunit. Therefore, even though each subunit contains all of the partial activities of the reaction sequence, the actual palmitate synthesizing unit consists of one-half of a subunit interacting with the complementary half of the other subunit.

The architecture of the animal fatty acid synthetase. III. Isolation and characterization of beta-ketoacyl reductase

Sequential treatment of the chicken liver fatty acid synthetase by trypsin and subtilisin cleaved the Mr 267,000 subunit to 6-8 polypeptides, ranging in molecular weights from 15,000 to 94,000. Fractionation of the digest by ammonium sulfate and chromatography on a Procion Red HE3B affinity column permitted the isolation of a polypeptide (Mr = 94,000) containing the beta-ketoacyl reductase activity but no other partial activities normally associated with the synthetase. The specific activity of the beta-ketoacyl reductase increased 2 to 3 times in this fraction, an increase that is within the expected range based on relative molecular weight. The kinetic parameters of this fraction towards NADPH and N-acetyl-S-acetoacetyl cysteamine were essentially the same as the beta-ketoacyl reductase component of the intact synthetase. However, the purified fragment did not catalyze the reduction of acetoacetyl-S-CoA derivative, a substrate that is readily reduced by the intact synthetase. Fluorescence measurements with etheno-NADP+ indicate the binding of about 1 mol of NADP+/94,000 daltons, a value which is in agreement with the results obtained from fluorescence measurements with NADPH and the binding of a radiolabeled photoaffinity analog of NADP+. Phenylglyoxal inhibits the beta-ketoacyl reductase activity of either the intact synthetase or the isolated fragment, suggesting the involvement of an essential arginine at or near the active site. Another fragment (Mr 36,000) containing beta-ketoacyl reductase activity was isolated from the synthetase after kallikrein/subtilisin double digestion. Previous mapping studies had shown that this fragment lies adjacent to the COOH-terminal thioesterase domain and overlaps the tryptic Mr 94,000 peptide by approximately 21 daltons. This fragment, but not the Mr 94,000 fragment, was found to contain the phosphopantetheine prosthetic group, indicating that the acyl carrier protein moiety is located in the 15,000-dalton segment that separates the beta-ketoacyl reductase from the thioesterase domain.

Computer modelling of ENT out-patients

The behaviour of queues in ENT out-patients has been simulated by a computer program. This allowed various appointment systems to be studied and improved to allow a smooth flow of patients through the clinic, in such a way that the idle time of the clinic staff is reduced without increasing patient waiting times.

HLA-A, B and HLA-DR phenotypes in Mainland Chinese patients with diabetes mellitus

HLA-A, B and DR antigens were studied in Mainland Chinese diabetes mellitus patients and controls (31 Type I DM, 50 Type II DM, 105 controls). HLA-DR3 and HLA-A9 were increased in Type I diabetics only. An increase in HLA-DR4 was noted in Type I diabetics, but the increase was not statistically significant in this small series.

A radioimmunoassay for neurotensin in human plasma

A specific radioimmunoassay for neurotensin in plasma has been developed with a sensitivity of 2 pmol/l of plasma. The antiserum was directed towards the amino terminal region of neurotensin and did not cross-react with other gastrointestinal peptides. Non-specific interference was eliminated and the sensitivity increased by extracting the plasma samples with ethanol prior to assay. Within- and between-assay coefficients of variation were 7.8% and .12% respectively. The mean plasma concentration of neurotensin in 30 fasting subjects was 29 +/- 4 pmol/l. A mixed meal increased plasma neurotensin from 16 +/- 2 to 53 +/- 6 pmol/l at 2 h.

A 13C N.M.R. study of some disaccharides from algal polysaccharides

The acid hydrolysis of agar, a partially methylated agar, and K-carrageenan initially gives the disaccharide resulting from cleavage of the link between the anhydrogalactose and the galactose units. A new method for isolating these disaccharides on a preparative scale is described, and their 13C n.m.r. spectra are listed and assigned.

Posttransplant serum analysis in human kidney allografts

Monitoring of 25 first cadaver transplant recipients was carried out weekly after transplantation. A total of 441 sera were tested from these patients against B and T lymphocytes at 4 degrees C and 37 degrees C for development of cytotoxic antibodies. Thirteen of the 25 patients (52%) developed B-cold antibodies as their first antibodies and all had functioning kidneys. Five of the patients developed B-warm antibodies initially, and all 5 rejected their transplants within 24 days. Of the seven patients who did not develop antibodies, 3 rejected their kidneys within 72 days. We conclude that it is important to distinguish between two types of antibodies to B lymphocytes--those reactive in the cold and those reactive in the warm--since they have opposite effects. Of the 17 successful grafts, 13 first developed B-cold cytotoxins.

Disposition of parenteral butorphanol in man

The metabolism and elimination of 3H-butorphanol (levo-3, 14-dihydroxy-N-(cyclobutylmethyl)[15-3H]morhinan) tartrate were determined in man after therapeutic im (2 mg) and iv (1 mg) doses. As judged from urinary excretion of radioactivity, the im dose was completely absorbed. Butorphanol was rapidly distributed to tissues, had a plasma half-life of about 3 hr, and was extensively metabolized prior to elimination. The major route of elimination was renal, with fecal excretion being a minor route. Hydroxybutorphanol [3, 14-dihydroxy-N-(trans-3'-hydroxycyclobutylmethyl)morphinan] was isolated and identified as a major urinary metabolite and was also present in the plasma. The disposition of butorphanol is compared and contrasted to the disposition of morphine and pentazocine.