Cholesteryl ester accumulation in smooth muscle cells after uptake of necrotic products from atherosclerotic lesions

Cholesterol-ladened plasma membrane vesicles were used to load smooth muscle cells (SMC) with cholesterol. Plasma membrane vesicles (PMV) were isolated from rabbit atherosclerotic lesions, and characterized as to size, cholesterol content, and marker enzyme (plasma membrane, lysosome, endoplasmic reticulum) composition. PMV were regarded as a necrotic product since they are produced upon injury to cells. Degradation of PMV was proportional to the PMV protein concentration in the culture medium, suggesting bulk intake of PMV. Cholesterol accumulation of SMC varied with the cholesterol content of the vesicle. Incubation for 3 days with PMV having 0.39 and 0.62 mg cholesterol/mg protein induced the accumulation of 8 and 29 micrograms of esterified cholesterol/mg cell protein, respectively. Incorporation of oleate into cholesteryl ester during a 24-hr period under these conditions, however, was the same. The contribution of cholesterol ester synthesis to the esterified cholesterol content of SMC was 40 and 11% of the total when exposed to PMV having, respectively, low and high contents of cholesterol. This study suggests that cholesterol-bearing PMV in lesions can be utilized to load lesion-SMC. These observations suggest that lipid-bearing elements other than low density lipoprotein may be responsible for cholesterol-loaded SMC in lesions.

Somatostatin may not be a hormonal messenger of fat-induced inhibition of gastric functions

The present study was designed to evaluate somatostatin as a hormonal inhibitor of gastric functions in humans. Seven healthy volunteers were investigated on 6 separate days. Peptone meal-stimulated gastric acid secretion was measured by intragastric titration for 2 h and gastric emptying was estimated with a dye-dilution technique. The effect of intravenous administration of somatostatin at 0, 12.5, 50, 100, and 200 pmol/kg.h was investigated and related to the effect of intragastric administration of 100 ml of vegetable oil. Plasma somatostatinlike immunoreactivity was elevated during intravenous administration of somatostatin at 100 and 200 pmol/kg.h, whereas no increase was detected in response to the oil. Somatostatin infusion at 100 and 200 pmol/kg.h significantly inhibited the acid secretion by 25% and 65%, and the oil reduced the acid output by 41%. Somatostatin at 100 and 200 pmol/kg.h significantly enhanced gastric emptying, whereas the oil inhibited gastric emptying. These observations suggest that somatostatin may not be an important hormonal messenger of fat-induced inhibition of acid secretion or gastric emptying.

The viability and regeneration of artificial cell microencapsulated rat hepatocyte xenograft transplants in mice

Viable hepatocytes were microencapsulated within artificial cells to form a bio-artificial liver. Trypan blue stain exclusion testing generally showed that 60% of the encapsulated hepatocytes remained viable immediately after encapsulation. To determine if xenogeneic hepatocytes can be successfully transplanted, encapsulated rat hepatocytes were implanted intra-peritoneally into mice and galactosamine induced liver failure mice. After 29 days of implantation in mice and 8 days of implantation in liver failure induced mice there was no significant change observed in the number of hepatocytes within the free floating microcapsules recovered from the peritoneal cavity. The percentage viability of the hepatocytes inside the recovered microcapsules increased from 62% to nearly 100% after 29 days of implantation in mice. The percentage viability of the encapsulated hepatocytes implanted in the liver failure induced mice was followed for 8 days. The percentage viability of the hepatocytes inside the microcapsule also increased from 42% to nearly 100%. In mice implanted with free rat hepatocytes, no viable hepatocytes were observed as early as 4 and 5 days after implantation. Instead a larger number of lymphoid cells and remnants of hepatocytes were recovered from the peritoneal cavity. In all cases the viability of the rat hepatocytes were determined with trypan blue stain.

Synthesis of hepatic lipase in liver and extrahepatic tissues

Immunoprecipitations of hepatic lipase from pulse-labeled rat liver have demonstrated that hepatic lipase is synthesized in two distinct molecular weight forms, HL-I (Mr = 51,000) and HL-II (Mr = 53,000). Both forms are immunologically related to purified hepatic lipase, but not to lipoprotein lipase. HL-I and HL-II are also kinetically related and represent different stages of intracellular processing. Glycosidase experiments suggest that HL-I is the high mannose microsomal form of the mature, sialylated HL-II enzyme. Hepatic lipase activity was detected in liver and adrenal gland but was absent in brain, heart, kidney, testes, small intestine, lung, and spleen. The adrenal and liver lipase activities were inhibited in a similar dose-dependent manner by hepatic lipase antiserum. Immunoblot analysis of partially purified adrenal lipase showed an immunoreactive band co-migrating with HL-II at 53,000 daltons which was absent in a control blot treated with preimmune serum. Adrenal lipase and authentic hepatic lipase yielded similar peptide maps, confirming the presence of the lipase in adrenal gland. However, incorporation of L-[35S]methionine into immunoprecipitable hepatic lipase was not detected in this tissue. In addition, Northern blot analysis showed the presence of hepatic lipase mRNA in liver but not adrenal gland. The presence of hepatic lipase in adrenal gland in the absence of detectable synthesis or messenger suggests that hepatic lipase originates in liver and is transported to this extrahepatic site.

Hematologic changes during sexual maturation. Why do black adolescents have low hemoglobin concentrations?

A group of black adolescents stratified by age and sexual maturity (Tanner stage) had electronic blood counts determined. Hemoglobin, hematocrit, and red cell count were lower than the means reported for white or Hispanic children of the same age. The difference could not be explained by iron deficiency, but the data were insufficient to exclude alpha thalassemia as a cause.

Hepatic lipase: a member of a family of structurally related lipases

Partial amino acid sequence of rat hepatic lipase was obtained by gas-phase microsequence analysis of proteolytic fragments. Sequence comparison to bovine lipoprotein lipase and porcine pancreatic lipase reveals a highly conserved region existing among these three physiologically distinct lipolytic enzymes. In a stretch of 36 amino acid residues previously reported for pancreatic lipase (De Caro, J., Boudouard, M., Bonicel, J., Guidoni, A., Desnuelle, P. and Rovery, M. (1981) Biochim. Biophys. Acta 671, 129-138), nineteen residues are identical for all three enzymes, whereas 27 of 36 are identical in rat hepatic lipase and bovine lipoprotein lipase. The fact that this primary structural conservation extends to three different animal species emphasizes the conclusion that these lipolytic enzymes comprise a protein family originating from a common ancestral gene.

Accumulation of cholesteryl ester and lipid droplets in macrophages after uptake of cholesterol-rich necrotic products

The prevalence of degenerated cells in the thickened intima of cholesterol-fed animals suggested that necrotic regions might become a focus for lesion development by attracting histiocytes or monocytes. We propose that cholesterol-rich necrotic products scavenged by macrophages incite the accumulation of cholesteryl ester and the formation of cholesteryl ester droplets. The feasibility of this hypothesis was tested with readily available materials, namely, lung macrophages and plasma membrane vesicles (PMV) released from dying cholesterol-rich and normal hepatocytes. PMV from cholesterol-rich hepatocytes contained 30-fold more cholesteryl ester than PMV from normal hepatocytes. Degradation of 125I-PMV to trichloroacetic acid-soluble products by macrophages was fourfold higher than that of 125I-acetylated low density lipoprotein (acetyl-LDL) at 100 micrograms/ml of ligand in the incubation medium. Within this concentration range, degradation of PMV increased almost linearly with increasing concentrations of PMV, while the degradation of acetyl-LDL followed a saturation curve. Cholesterol-rich PMV increased the cholesteryl ester content of macrophages fourfold and augmented the incorporation of oleate threefold relative to normal PMV. These studies were extended to aortic smooth muscle cells. As with hepatocyte-PMV, smooth muscle cell-PMV was internalized and degraded by macrophages. The results suggested that cholesterol-rich necrotic materials could play a significant role in atherogenesis.

Gender-related effects of chronic ethanol ingestion on rat hepatic acyl-CoA:cholesterol acyltransferase

The influence of chronic ethanol ingestion on hepatic acyl-CoA: cholesterol acyltransferase activity was investigated to determine the relationship between alcohol intake and cholesterol ester accumulation. Rats were given nutritionally complete liquid diets supplemented with 6.3% ethanol or an isocaloric equivalent of dextrin-maltose for 5 weeks. During this period, the hepatic acyl-CoA: cholesterol acyltransferase activity of ethanol-fed male rats remained constant, whereas the same activity in pair-fed controls as well as chow-fed rats exhibited a 30% decrease in activity. Unlike alcohol-fed male rats, the hepatic acyl-CoA: cholesterol acyltransferase activity of female rats decreased by approximately 30% by the fifth week of ethanol ingestion. Despite the fact that the gender of the animals led to disparate levels of acyl-CoA: cholesterol acyltransferase activity in response to ethanol ingestion, similar levels of cholesteryl ester accumulation were observed. The altered levels of acyl-CoA: cholesterol acyltransferase activity caused no significant change in the cholesterol concentration, cholesterol/phospholipid ratio, phospholipid fatty acid composition, or the membrane fluidity of the hepatic microsomes. We conclude that the altered hepatic acyl-CoA: cholesterol acyltransferase activity of ethanol-fed female rats cannot be directly responsible for ethanol-induced accumulation of cholesteryl esters.

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.

Subjective distresses of nasogastric tube feeding

Health care professionals assume that tube feeding is an unpleasant, distressing experience for patients, which is only partially substantiated by experience. Thirty patients were interviewed via a tube feeding and hospital experience checklist (a 47-item interview schedule). Common experiences were operationally defined as those felt by at least 50%; subjectively distressful experiences were those identified by patients as causing distress. The most common and most distressful experiences of nasogastric tube feeding were: sensory irritations and sensory deprivation. The psychosensory irritation experiences were: thirst, sore nose or throat, dry mouth, runny nose, a tube in the nose, taking food through a tube, breathing through the mouth, breathing with a tube in the nose, taking food in a treatment type container, and taking food with a different texture and smell than usual. The psychosensory deprivation experiences were: an unsatisfied appetite for certain foods, deprivation of tasting, chewing, swallowing food, and drinking liquids, limited mobility, and deprivation of regular food. Except for burping, gastrointestinal symptoms were not common though they were usually distressful. This information has been used to develop teaching programs which are being tested for effectiveness in reducing distress associated with nasogastric tube feeding.

Comparison of the effects of ultraviolet light and purinergic nerve stimulation on the guinea-pig taenia coli

1 The responses of the guinea-pig taenia coli, urinary bladder, and the rabbit portal vein to ultraviolet (u.v.) light were compared to those elicited by purinergic nerve stimulation and exogenous adenosine triphosphate (ATP).2 In the presence of sodium nitrite, u.v. light between 340-380 nm produced a maximum relaxation of the taenia coli. The relaxation was reversible and fast in onset. It was unaffected by atropine, guanethidine or low concentrations of phentolamine or propranolol. When the tone was low, the relaxation was usually followed by a ;rebound contraction' upon cessation of stimulation. Thus, the response to u.v. light closely resembles the responses to both purinergic nerve stimulation and exogenously applied ATP.3 U.v. light did not initiate impulses in purinergic nerves since its action was unaffected by tetrodotoxin; nor did it release ATP from nerve terminals (in contrast to its release during purinergic nerve stimulation). The adenosine-uptake inhibitor, dipyridamole, which potentiates the responses to purinergic nerve stimulation and ATP, did not affect the response to u.v. light.4 Agents known to alter postjunctional responses to purinergic nerve stimulation and ATP also altered the response to u.v. light. High concentrations of the 2-substituted imidazoline compounds, antazoline and phentolamine, which antagonize the responses to purinergic nerve stimulation and ATP, reduced the responses to u.v. irradiation. The prostaglandin synthesis inhibitor, indomethacin, which abolishes the ;rebound contraction' following stimulation of purinergic nerves, also blocks the ;rebound ;contraction' following u.v. irradiation. Increases in the K(+) concentration produced parallel changes in the inhibitory responses to u.v. light and purinergic nerve stimulation.5 U.v. light produced relaxation and inhibition of spontaneous activity of the rabbit portal vein (relaxed by ATP), but had no effect on the guinea-pig urinary bladder (contracted by ATP) and ureter (unaffected by ATP).6 It is suggested that u.v. light is acting on some part of the purinergic receptor complex which is involved in the mediation of inhibitory responses to ATP and purinergic nerve stimulation, and may therefore provide a way of investigating the chemistry of inhibitory purinergic receptors.