A novel endothelial-derived lipase that modulates HDL metabolism.

High-density lipoprotein (HDL) cholesterol levels are inversely associated with risk of atherosclerotic cardiovascular disease. At least 50% of the variation in HDL cholesterol levels is genetically determined, but the genes responsible for variation in HDL levels have not been fully elucidated. Lipoprotein lipase (LPL) and hepatic lipase (HL), two members of the triacylglyerol (TG) lipase family, both influence HDL metabolism and the HL (LIPC) locus has been associated with variation in HDL cholesterol levels in humans. We describe here the cloning and in vivo functional analysis of a new member of the TG lipase family. In contrast to other family members, this new lipase is synthesized by endothelial cells in vitro and thus has been termed endothelial lipase (encoded by the LIPG gene). EL is expressed in vivo in organs including liver, lung, kidney and placenta, but not in skeletal muscle. In contrast to LPL and HL, EL has a lid of only 19 residues. EL has substantial phospholipase activity, but less triglyceride lipase activity. Overexpression of EL in mice reduced plasma concentrations of HDL cholesterol and its major protein apolipoprotein A-I. The endothelial expression, enzymatic profile and in vivo effects of EL suggest that it may have a role in lipoprotein metabolism and vascular biology.

Carbamycholine prevents giant granule-formation in cultured fibroblasts from beige (Chediak-Higashi) mice.

Primary embryonic fibroblasts isolated from beige (Chediak-Higashi) mice develop pathognomonic giant granules in vitro. Inclusion in the culture medium of carbamylcholine (carbachol) or phorbol myristate acetate (PMA) results in the generation of morphologically normally granules. Chediak-Higashi fibroblasts are highly susceptible to shape changes induced by colchicine. This abnormal property is also corrected by carbachol and PMA.

Modified PAXgene method allows for isolation of high-integrity total RNA from microlitre volumes of mouse whole blood.

Analysis of gene expression is often used to evaluate the effects of experimental manipulations in laboratory animals. Blood is a rich source of potential biomarkers, including gene expression information, which may be obtained from whole blood. When compared with the end of a study, when whole blood samples can be easily obtained for gene expression measurements, the limiting volumes of whole blood obtainable from animals during the course of an experiment requires a method for RNA isolation from a minimal volume of whole blood. The PAXgene Blood RNA Extraction System originally designed for isolation of total RNA from 2.5 mL of human whole blood, was modified and successfully used to isolate high-integrity total RNA from as little as 50 microL of mouse whole blood. Fifty microlitres of mouse whole blood yielded an average of 2.3 microg highly intact total RNA, of sufficient quality and quantity allowing for multiple gene expression determinations. The utility of this method was demonstrated by confirming the time- and dose-dependent upregulation of haem oxygenase-1 (Hmox1) mRNA in response to a single injection of cobalt protoporphyrin. The successful isolation of total RNA from small volumes of mouse whole blood can allow for serial sampling on the same animals, thereby reducing the number of animals required for experimentation.

Comparison of 18O exchange and pH stop-flow assays for carbonic anhydrase.

The hydration velocity of CO2 (0.002 M) catalyzed by bovine carbonic anhydrase (BCA) was measured at 25 degrees C and pH 7.4 by three different techniques: two initial-rate (steady-state) stop-flow methods, one using a glass pH electrode (in Hannover, method 1) and one using spectrophotometric measurements of a pH indicator (in Philadelphia, method 2), and an exchange method in which the disappearance of C18O16O from a bicarbonate solution was determined at equilibrium (in Philadelphia, method 3). The Michaelis-Menten constant (Km) and the inhibition constants for chloride (Ki,Cl) and ethoxzolamide (Ki,ez) were the same for methods 1, 2, and 3. The turnover numbers were 270,000, 400,000, and 555,000 s-1 by methods 1, 2, and 3, respectively. Values for CO2 hydration velocity measured by methods 2 and 3 on the same solution of BCA at the same time were the same. Km, maximal reaction velocity (Vmax), Ki,ez, and Ki,Cl obtained from normal human hemolysate at 37 degrees C and pH 7.2 by methods 2 and 3 were the same. Km and Vmax of the carbonic anhydrase isozyme CA III of homogenate from rabbit soleus were also identical by methods 1 and 3. According to Michaelis-Menten theory, the values of Km and Vmax obtained by method 3 should have been significantly smaller than those obtained by methods 1 and 2. We conclude that the catalytic step itself is apparently not rate limiting under physiological conditions and that method 3 can be used to obtain Michaelis-Menten characteristics of carbonic anhydrase.

Inflammatory bowel disease in migrant and native Jewish populations of southern Israel.

Ulcerative colitis and Crohn's disease were studied in three Jewish populations in the Beer Sheva district of southern Israel. Age-adjusted prevalence rates on 31 December 1987 were for ulcerative colitis, 89/10(5), and for Crohn's disease, 30/10(5). Both diseases were commoner in females and in European-American-born Jews. Age-adjusted incidence rates have increased and in 1979-1987 were for ulcerative colitis, 5.4/10(5)/year, and for Crohn's disease, 2.1/10(5)/year. Females developed ulcerative colitis at a younger age and Crohn's disease at a later age than males. Israel-born patients developed both diseases at a young age. The clinical features of ulcerative colitis were similar in the various populations. Epidemiologic data in Jews may aid in the understanding of the pathogenesis of inflammatory bowel diseases.

Ulcerative colitis in the Jewish population of southern Israel 1961-1985: epidemiological and clinical study.

The incidence of ulcerative colitis in the Jewish population of Southern Israel has increased in the period 1961-85 and is presently 5.8/10(5)/year. The mean annual incidence was significantly higher in European and American born (10.8/10(5)/year) than in Asian and African or Israeli born Jews. The disease was significantly more prevalent in women, who developed the illness at a younger age and had a milder course. The age adjusted prevalence rate in each population group was greater than the rates detected by earlier studies in other areas of the country (p less than 0.05). The prevalence rate in the total population now approximates the moderate to high prevalence rates of ulcerative colitis found in many other localities. The particularly high rates of ulcerative colitis in the European and American born population in Israel, in Jews residing in Western countries, and in certain non-Jewish populations in Great Britain and Northern Europe may imply the presence of a common aetiological mechanism.

Incidence of idiopathic ulcerative colitis in Jewish population subgroups in the Beer Sheva region of Israel.

The epidemiology and clinical features of idiopathic ulcerative colitis in different Jewish population groups in the Beer Sheva district of Israel were studied retrospectively over the period 1961-85. The average annual age-adjusted incidence rate increased (p less than 0.05) in all population groups during this period. The incidence rate in the total population in 1981-85 was 5.8 per 10(5) population per yr. In European and American born subjects the incidence rate was twice as high as in Asian and African born and Israeli born subjects. The mean age of onset of ulcerative colitis was significantly lower in Israeli born persons (26.8 yr) than in the other population groups; when the total population was stratified by age, this difference was shown to be caused by the relative youthfulness of the Israeli born subpopulation. Despite these striking epidemiological differences, clinical features were similar in the three population groups.

Aspects of the epidemiology of Crohn's disease in the Jewish population in Beer Sheva, Israel.

The epidemiology of Crohn's disease in Jews in the Beer Sheva district of Israel was studied. The mean annual incidence per 10(5) population was 1.1 for the period 1961-80 and 1.8 for the period 1976-80. The crude prevalence rate on 31 December 1980 was 14.0 per 10(5) population. The unadjusted prevalence rates by place of birth were: Israeli-born 6.9, European/American-born 24.6 and Asian/African-born 19.4 per 10(5) population. The age-adjusted prevalence rates were: Israeli-born 9.7, European/American-born 15.8 and Asian/African-born 12.5 per 10(5) population. The study has demonstrated: 1) that Crohn's disease has a low prevalence in Jews in this district; 2) that Crohn's disease is not as uncommon in Asian/African-born Jews as was previously thought; 3) that the low crude rate of Crohn's disease in Israeli-born Jews in this district is partially accounted for by the age distribution of the population; and 4) that environmental rather than genetic factors appear to determine the incidence of Crohn's disease in this district.

Varicoid carcinoma of the esophagus. Report of a patient with adenocarcinoma and review of the literature.

A patient with varicoid carcinoma of the esophagus is reported. These tumors differ from classical esophageal carcinoma and have some resemblance to esophageal varices in their radiological and endoscopic appearances. Dysphagia is generally not the presenting symptom. The histological picture in our patient was that of a poorly differentiated adenocarcinoma with areas of signet-cell carcinoma. This is an exceptional finding since all previously reported cases of varicoid carcinoma of the esophagus have been squamous cell carcinomas.

Granular cell myoblastoma of the sigmoid colon.

A granular cell myoblastoma of the upper sigmoid colon is reported in a 53-year-old male. The tumor was detected during investigation of abdominal pain and was removed by colonoscopic polypectomy. Colonoscopy provides a new method of treatment for these unusual colonic lesions and avoids the need for surgery. To our knowledge the tumor has not been reported previously in the sigmoid colon.

Role of cyclic GMP in gastrin secretion from rat antral mucosae in organ culture.

Rat antral mucosae maintained for 6 h in organ culture responded to carbamylcholine with a significant increase in endogenous cyclic GMP production and gastrin secretion. The acetylcholine analogue exerted a stimulatory action within a defined concentration range: exposure of antral explants to carbachol concentrations greater than the optimal stimulatory dose was accompanied by a marked decrease in both cyclic GMP production and gastrin release. Exogenous 8-Br-cyclic GMP (1 mM) significantly augmented gastrin secretion into the culture media during 6-12 h culture periods. Cycloheximide (0.1 mM) and the Ca2+ channel-blocker verapamil (5 microM) prevented 8-Br-cyclic GMP from acting as a gastrin secretagogue. Addition of cyclic somatostatin-14 (0.1 mM) to culture media was attended by complete inhibition of 8-Br-cyclic GMP-stimulable gastrin secretion. These results provide evidence that cyclic GMP may play a mediatory role in the coupling of gastrin secretory processes to agonist stimulation. It would seem that the secretagogue action of 8-Br-cyclic GMP requires unabated Ca2+ transmembrane fluxes and protein biosynthesis. Since somatostatin-14 abrogates the stimulatory effect of 8-Br-cyclic GMP on antral gastrin secretion, it is surmised that the inhibitory tetradecapeptide acts at a locus (or loci) distal to domains involved in the actual generation of the cyclic nucleotide.

Esophageal carcinoma in Indian Jews of southern Israel. An epidemiologic study.

The incidence of esophageal cancer varies in different populations and localities. The varied composition of the immigrant population of southern Israel afforded us an opportunity to investigate the frequency of the disease. The results of a retrospective study (1961-1985) revealed a high mean age-adjusted incidence rate (per 10(5)) in immigrant Indian men (6.5 +/- 2.17) and Indian women (17.2 +/- 5.12). Rates in all non-Indian immigrants were significantly lower: men 2.7 +/- 1.19, women 2.1 +/- 0.24. The relative risk of developing the disease was significantly higher in Indians. The age at diagnosis was lower in Indian women (54.6 +/- 10.4 years) than Indian men and other immigrants (p less than 0.05). The clinical features were similar in all cases. The risk factors in Indian men were not apparent; in women, the indiscrete use of spices might have raised the rate of esophageal cancer. The disease is more frequent in Indian populations in several parts of the world, and vigilance is required on the part of physicians.

Regional difference in ambient intraluminal gastric acidity after cimetidine monitored by intragastric pH-metry.

Acid secretion was monitored in five duodenal ulcer patients using intragastric glass pH electrodes located in the gastric body and antrum under basal conditions and after the administration of cimetidine. It was shown that differences exist between the body and antral pH in the basal state and in the response to cimetidine. The basal hydrogen ion concentration (mean +/- SEM, mmol/l) in the body, 25.97 +/- 5.03, exceeded that in the antrum, 10.59 +/- 6.44 (p less than 0.05). After cimetidine, the pH rose to 3.5 at both electrodes, this stage being shorter in the antrum (16 min) than body (54 min) (p less than 0.0125). During the next stage the pH rose above 3.5 and the hydrogen ion concentration (mean +/- SEM, mmol/l) was very low in both the body, 0.05 +/- 0.01 (p less than 0.0005 compared to basal) and antrum, 0.08 +/- 0.05 (p less than 0.05 compared to basal). Recovery to basal pH levels occurred more quickly in the body than antrum. Intragastric pH-metry offers a reliable method for studying the mode of action of pharmacological agents on the stomach and contributes information not made available by routine gastric analysis.

Enterocolitis complicating chrysotherapy. Case report and review of the literature.

We report a case of a 71-yr old man with seronegative rheumatoid arthritis, who developed severe enterocolitis during gold therapy. Radiological studies, endoscopy and biopsies showed diffuse involvement of the stomach, duodenum and small and large intestines. The clinical course was prolonged and complicated by multiple infections. Of the 10 cases with chrysotherapy-induced enterocolitis reported in the literature, 3 were from Israel. There may be a relationship between the development of enterocolitis following gold therapy, ethnic group and HLA-B8 and DRw3 antigens.

Differential distribution of protein kinases along the crypt-to-lumen regions of rat colonic epithelium.

The activity of cAMP-dependent and cAMP-independent protein kinases, a class of enzymes involved in the regulation of cell proliferation was measured in rat colonic epithelium. Sequential cell populations harvested by a stepwise scraping technique from colonic crypt regions were identified by histology and incorporation of [3H]-thymidine into DNA. cAMP-independent phosphorylation of casein, in the presence of [gamma-32P]ATP, was markedly suppressed by quercetin, a bioflavonoid known to inhibit G-type casein kinase, protein kinase-C and tyrosine protein kinase. Conversely, the cyclic nucleotide regulatable form requiring histone as substrate was responsive to the action of the heat stable protein kinase inhibitor. The protein kinase species were characterised and partially purified by DEAE-cellulose chromatography. The activity of cAMP-dependent protein kinase in colonic cytosols (pmol 32P/min/mg protein, means (SE)) increased from 129.4 (15.9) in superficial cell populations to 238.5 (31.4) in lower crypt cell fractions (p less than 0.01). Colonic cAMP-independent protein kinase activity increased from 87.3 (15.6) in surface cell preparations to 178.1 (30.0) in lower crypt cell populations (p less than 0.02). A comparable activity gradient was observed in membrane fractions. The activity gradient persisted when the results were expressed as a function of cellular DNA. These findings indicate that protein kinases display a defined topological segregation along the colonic crypt regions and that during migration to the lumen colonic cells attenuate enzyme signals supposedly related to tissue growth.

An evaluation of arbaprostil at multiple doses for the treatment of acute duodenal ulcer: a randomized double-blind placebo-controlled international trial.

Six hundred and thirty patients were enrolled in a randomized double-blind placebo-controlled trial evaluating two arbaprostil dosages (25 micrograms and 50 micrograms) qid for 4 wk for the treatment of acute duodenal ulcers. The healing rates in the placebo, 25-micrograms, and 50-micrograms treatment groups were 39%, 51%, and 60%, respectively. Smoking was found to adversely affect the healing rates in all the treatment groups. Pain severity was less with either arbaprostil treatment. The only side effect found was diarrhea: 10%, 14%, and 32% in the placebo, 25-micrograms, and 50-micrograms treatment groups, respectively. Severe diarrhea occurred in 1% of those patients who received the 50-micrograms dosage regimen, but in none of the other two groups. Arbaprostil at these two dosage levels, when given for 4 wk, appears to be a safe and efficacious agent for the treatment of acute duodenal ulcers.

Tyrphostins inhibit PDGF-induced DNA synthesis and associated early events in smooth muscle cells.

Tyrphostins are low-molecular-weight synthetic inhibitors of protein tyrosine kinase, which block cell proliferation. Since platelet-derived growth factor (PDGF) is thought to figure prominently in disorders of vascular smooth muscle cells (VSMC), such as atherosclerosis, hypertension, and restenosis, we examined whether tyrphostins would inhibit PDGF-induced mitogenesis in VSMC. In this communication, we demonstrate that tyrphostins with the benzenemalononitrile nucleus inhibited PDGF-dependent growth of VSMC as well as PDGF-dependent DNA synthesis in these cells, with the concentrations for 50% inhibition ranging from 0.04 to 9 microM. Up to 30-fold higher tyrphostin concentrations were required to inhibit serum-stimulated DNA synthesis of VSMC. The effect of the tyrphostins is reversible, since on their removal a normal proliferative response to PDGF was resumed. Tyrphostins also inhibited PDGF-receptor autophosphorylation and PDGF-induced phosphorylation of intracellular substrates, including the phosphorylation of phospholipase C-gamma, with a potency ratio similar to their antimitogenic activity. The expression of c-fos mRNA, a mitogenic nuclear signal, was also reduced in PDGF-stimulated VSMC treated with tyrphostins at concentrations which inhibit PDGF-induced mitogenesis. It is concluded that tyrphostins are potent reversible inhibitors of PDGF-induced mitogenesis which act by inhibiting the tyrosine kinase activity of the PDGF receptor and the subsequent signaling cascade. Tyrphostins may be useful in the study and treatment of VSMC proliferation disorders.