Endothelin-1 is an autocrine/paracrine factor in the mechanism of angiotensin II-induced hypertrophy in cultured rat cardiomyocytes.

To elucidate the cellular mechanism by which angiotensin II (ANG II) induces cardiac hypertrophy, we investigated the possible autocrine/paracrine role of endogenous endothelin-1 (ET-1) in ANG II-induced hypertrophy of neonatal rat cardiomyocytes by use of synthetic ET-1 receptor antagonist and antisense oligonucleotides to preproET-1 (ppET-1) mRNA. Northern blot analysis and in situ hybridization revealed that ppET-1 mRNA was expressed in cardiomyocytes, but, to a lesser extent, in nonmyocytes as well. ANG II upregulated ppET-1 mRNA level by threefold over control level as early as 30 min, and it stimulated release of immunoreactive ET-1 from cardiomyocytes in a dose- and time-dependent manner. ET-1 stimulated ppET-1 mRNA levels after 30 min in a similar fashion as ANG II. Tetradecanoylphorbol-acetate (10(-7) M) mimicked the effects of ANG II and ET-1 on induction of ppET-1 mRNA. ANG II-induced ppET-1 gene expression was completely blocked by protein kinase C inhibitor H-7 or by down-regulation of endogenous protein kinase C by pretreatment with phorbol ester. ET-1 and ANG II stimulated twofold increase [3H]leucine incorporation into cardiomyocytes, whose effects were similarly and dose dependently inhibited by endothelin A receptor antagonist (BQ123). Introduction of antisense sequence against coding region of ppET-1 mRNA into cardiomyocytes resulted in complete blockade with ppET-1 mRNA levels and [3H]leucine incorporation stimulated by ANG II. These results suggest that endogenous ET-1 locally generated and secreted by cardiomyocytes may contribute to ANG II-induced cardiac hypertrophy via an autocrine/paracrine fashion.

Action of bredinin on mammalian cells.

Bredinin, a new nucleoside antibiotic, inhibited multiplication of several mammalian cell lines in culture and had a cytotoxic effect on L5178Y cells. Growth inhibition by bredinin was prevented by guanosine 5'-monophosphate (GMP), guanosine, or guanine but not by other purine or pyrimidine nucleotides, nucleosides, or bases. Inhibition by bredinin at a low GMP; but at higher concentrations of bredinin the inhibition was not reversed even when the concentration of GMP was raised. Addition of GMP after cellular damage had occurred produced no effect on the damaged cells but it prvented further damage. Bredinin caused marked chromosomal aberrations such as breakages, translocations, and fragmentation in L5178Y cells.

Amino acid sequences of cytotoxin-like basic proteins derived from cobra venoms.

Amino acid sequences of cytotoxin-like basic proteins (CLBPs), purified from the venoms of Formosan cobra (Naja naja atra) and Indian cobra (Naja naja), were reinvestigated. The determined sequences differed from those reported previously by Takechi et al. [(1985) Biochem. Int. 11, 795-802; (1987) Biochem. Int. 14, 145-152]. The sequence of CLBPs at residues 25-30 was found to be hydrophilic as compared with those of cytotoxins. The difference in the hydrophobicity of this region might be responsible for the difference in their cytotoxic activities.

Effect of omeprazole on changes in gastric and upper small intestine pH levels in patients with chronic pancreatitis.

Gastric and upper small intestine pH levels were measured continuously over 24 hours in patients with chronic pancreatitis, and values obtained before and after the administration of omeprazole were compared. Additionally, omeprazole was administered for 2 weeks and the fecal excretion of fat was compared before and after drug therapy. Postprandial gastric pH levels, initially 2.9 to 3.2, increased by 1.6 to 2.1 after treatment. Postprandial upper small intestine pH levels, initially 5.1 to 5.5, increased by 0.7 to 1.0. The lowest pH value of the upper small intestine was 2.2 to 2.4 postprandially; this was increased by > 1.0 after omeprazole, and the amplitude of pH variation was reduced. The cumulative proportions of intraintestinal pH strata of < or = 3, < or = 4, or < or = 5, and higher, initially being 16.4% to 17.1%, 27.4% to 31.7%, and 52.6% to 57.8%, respectively, were remarkably improved after drug treatment. Gastric pH and upper small intestine pH levels showed a positive correlation; an increase in gastric pH levels by 2 corresponded to an increase in small intestine pH levels by 1. After omeprazole administration, mean fecal excretion of fat was decreased to 4.1 +/- 2.6 g/d (range, 1.1 to 9.8 g/d) from 6.5 +/- 3.9 g/d (range, 1.6 to 13.5 g/d). Decreases in excretion of fat averaged 3.4 g/d (range, 2.2 to 4.5 g/d) in patients with steatorrhea. It was concluded that steatorrhea due to chronic pancreatitis can be improved to some extent by improving upper small intestine pH levels following the elevation of gastric pH levels after administration of omeprazole.

Nonselective ETA/ETB receptor antagonist blocks proliferation of rat vascular smooth muscle cells after balloon angioplasty.

To elucidate the role of endothelin receptor subtypes in the abnormal proliferation of vascular smooth muscle cells (VSMC) associated with vascular injury, we have investigated the effects of a novel and potent nonselective ETA/ETB receptor antagonist (TAK-044) on the proliferation of rat VSMC in vitro and in vivo. TAK-044 dose-dependently inhibited DNA synthesis stimulated by 10(-7) M ET-1 in cultured rat VSMC from the late passage with the approximate IC50 of 6 x 10(-8) M. After balloon angioplasty, the neointimal lesion in the injured carotid arteries in the TAK-044-treated group (0.052 +/- 0.014 mm2) was significantly (p < 0.05) decreased compared to that in control group (0.26 +/- 0.045 mm2), while the medial surface area was not affected. The intima/media ratio in the TAK-044 group (31 +/- 6%) also significantly (p < 0.05) decreased from that of the control group (148 +/- 25%). Our data suggest that nonselective ETA/ETB receptor antagonists may be therapeutic potential for prevention against the intimal thickening associated with vascular injury.

Effect of bredinin and its aglycone on L5178Y cells.

The aglycone of the nucleoside antibiotic, bredinin, was as strongly cytotoxic to L5178Y cells as bredinin. The cytotoxic properties of the aglycone were very similar to those of bredinin and the minimum inhibitory concentrations of both were 10(-5)M. The growth inhibitory effects of both agents regardless of their concentrations, were reversed by guanylic acid, guanosine or guanine. However, on increasing the concentrations of these agents, the reversing effect of guanylic acid decreased gradually, the dose-response curves for the two agents being similar. Both agents inhibited the incorporation of thymidine and uridine, but not leucine into macromolecules in L5178Y cells and their inhibitory effects were reversed to similar extents by guanylic acid. On the other hand, the growth inhibitory effect of the aglycone on L5178Y cells was prevented by adenine only, though not be adenosine or adenylic acid while the effect of bredinin was not prevented by adenine. These results suggest that the aglycone itself does not inhibit growth, but that its effect is due to its conversion to bredinin by an enzyme such as adenine phosphoribosyl transferase. For recovery of growth, three moles of adenine were required per mole of the aglycone. When the aglycone was administered orally to rats, bredinin was administered orally to rats, bredinin was recovered in their serum and urine.

Studies on neplanocin A, new antitumor antibiotic. I. Producing organism, isolation and characterization.

Neplanocin A. C11H13N5O3, is a novel carbocyclic analog of adenosine with cyclopentene. It was isolated from the culture filtrate of Ampullariella regularis A11079 by means of ion-exchange, carbon, silica gel adsorption, or partition chromatography. Neplanocin A forms crystals, and is stable at acidic or alkaline pH. Neplanocin A has cytotoxicity against L5178Y cells in culture and showed a remarkable effect on the life prolongation of mice infected with L1210 leukemia.

Isolation and characterization of new thiol protease inhibitors estatins A and B.

New thiol protease inhibitors, estatins A and B, were isolated from the culture filtrate of Myceliophthora thermophila M4323. The basic, water-soluble inhibitors were characterized as having an agmatine, trans-epoxysuccinic acid and L-phenylalanine or L-tyrosine moieties in the structure. The molecular formulas C18H25N5O5 and C18H25N5O6 for A and B were indicated by elemental analysis and fast atom bombardment MS. Estatins were specific inhibitors against thiol proteases such as papain, ficin and bromelain. They suppressed IgE antibody production in mice, but not IgG.

Mode of action of bredinin with guanylic acid on L5178Y mouse leukemia cells.

Moderate concentrations of bredinin (1.2 X 10(-5) M) strongly inhibited growth of L5178Y cells, with the effect being reversed by guanylic acid (GMP). However, at higher concentrations of breeding the inhibition was not reversed completely by GMP added in excess. Bredinin was cytocidal at concentrations above 2 X 10(-5) M, but 5 X 10(-5) M bredinin in the presence of excess GMP, bredinin was cytostatic. Bredinin inhibited nucleic acid synthesis of L5178Y cells, but bredinin itself was not incorporated into the nucleic acid. Inhibition of nucleic acid synthesis was clearly reversed by GMP. Similarly chromosomal aberrations in L5178Y cells caused by bredinin were reversed by GMP. In contrast, the effect of ahigh concentration of bredinin on cell multiplication was not reversed by GMP. The modal volume of L5178Y cells increased during incubation in the presence of bredinin and GMP for 24 hours, 5 X 10(-5) M bredinin with GMP causing a 70% increase in cell volume. This increase in cell volume was mainly due to an increase in the protein content of the cells. The cytostatic effect of bredinin with GMP was reversed completely by adenosine-3',5'-cyclic monophosphate (cyclic AMP). Other cyclic nucleotides and nucleotides were ineffective. The reversing effect of cyclic AMP on cell survival depended upon the concentration of GMP, and was not seen in the absence of GMP. It was concluded that cyclic AMP influences the secondary cytostatic effect of bredinin, and not the primary cytotoxic effect reversed by GMP.

[Superoxide anion (O2-) production by polymorphonuclear leukocytes in insulin dependent diabetes mellitus (IDDM)].

The superoxide anion (O2-) production in polymorphonuclear leukocytes stimulated by phorbol myristate acetate in IDDM and non-insulin dependent diabetes mellitus (NIDDM) was determined by the method of Johnston et al, compared with that of each age matched controls. And the correlation between O2- production and hemoglobin (Hb) A1 and A1c value was investigated. The O2- production in IDDM was 24.4 +/- 7.4 (mean +/- SD, n mol per 4 X 10(5) cells) at 10 min. and 51.4 +/- 8.7 at 30 min., in NIDDM each 31.6 +/- 9.3, 60.2 +/- 14.4, and in controls each 40.5 +/- 4.2, 72.4 +/- 3.1. O2- production in IDDM was significantly lower than that in NIDDM (p less than 0.001 at 10 min. and p less than 0.01 30 min.) and controls (p less than 0.001 at 10 and 30 min.). O2- production at 10 and 30 min. possessed a negative correlation with Hba1 and A1c value (HbA1: p less than 0.01 at 10 min. p less than 0.05 at 30 min., HbA1c: p less than 0.01 at 10 and 30 min.). These findings suggest that impaired O2- production might be one of the factors accounting for depressed bactericidal activity of polymorphonuclear leukocytes in IDDM, and that a protracted hyperglycemia might shed some effect on O2- production.

[Peripheral lymphocyte subset of patients with pancreatic diabetes mellitus--about a decreased ratio of T-LGL and ability of host defense].

Patients with diabetes mellitus (DM) often suffer from various and severe infection. Patients with pancreatic DM have malnutrition due to chronic pancreatitis. Therefore it is believed that patients with pancreatic DM have a lower ability of host defence to infectious diseases than normal subjects. We examined the primpheral lymphocyte subsets (T cell, B cell, NK cell, CD3+ 56+ T) of eighteen patients (males, age = 52.8 +/- 12.7 years old, mean +/- SD) with pancreatic DM by two color flow-cytometry to evaluate the lymphocyte function. Ratios of T cell (T%, 66.9 +/- 9.3%, mean +/- SD). B cell (B%, 13.1 +/- 5.8%) and NK cell (Nk%, 19.3 +/- 8.7%) to total peripheral lymphocytes of patients with pancreatic DM were not significantly different from those (T% = 66.4 +/- 7.8%, B% = 13.5 +/- 6.7%, NK% = 19.9 +/- 9.1%) of thirteen normal subjects (males, age = 51.2 +/- 13.1). CD3+56+ T cell % (4.1 +/- 1.9%) of patients with pancreatic DM was lower than that (6.0 +/- 3.0%) of normal subjects (p < 0.05). CD3+56+ T cells have cytotoxic activity and it is likely that this activity is similar to that of NK cells. These results suggested that a decrease in peripheral CD3+56+ T cell % is a factor showing a weak host defense mechanism to infectious diseases in patients with pancreatic DM.

[Antigenicity study of rokitamycin].

The antigenicity of rokitamycin (TMS-19-Q, TMS) was studied. Rabbits and mice were repeatedly challenged with TMS emulsified with adjuvant to be strongly immunized. Neither IgG nor IgE antibodies were, however, detected in serum from these animals when assayed by PCA and PHA reactions. Furthermore, guinea pigs immunized with TMS together with Freund's complete adjuvant did not exhibit any systemic anaphylactic reactions when elicited with TMS alone. In contrast, specific antibody production against TMS was confirmed in animals immunized with chemically introduced antigen of TMS-carrier protein conjugate, where TMS had antigenic nature as hapten.

[In vitro antibacterial activity of vancomycin in combination with panipenem against carbapenem-resistant MRSA].

The synergistic relationship between vancomycin (VCM) and carbapenem (CRB) has been reported in antibacterial activity against CRB-resistant strains of MRSA. The purpose of this study is to investigate the antibacterial activity against CRB-resistant MRSA using VCM, panipenem (PAPM), and a combination of both. 8 strains of CRB-resistant MRSA were used to examine the effects of these antibiotics by the broth microdiluton technique. The effect of pH (pH 6, 7, 8) on MIC of VCM alone was not observed in 7 out of 8 strains; MICs were between 1.0-2.0 micrograms/ml. PAPM alone, however, showed an enhancing tendency in alkaline condition in 6 out of 8 strains. There was no influence of pH on MICs in the combination use of VCM and PAPM, showing additive effect in 1 strain and synergistic in 6 strains. Killing-curves against PAPM-resistant MRSA were examined under the following drug combinations; 1/4 MIC of VCM (0.5 micrograms/ml) plus 1/4 MIC of PAPM (16 micrograms/ml), and 1/4 MIC of VCM plus 1/8 MIC of PAPM (8 micrograms/ml). The former drug combination showed synersistic effect; decrease from 1.05 x 10(5) to 6.45 x 10(4) CFU/ml after 6 hours' incubation and to less than 10 CFU/ml after 24 hours. The latter drug combination showed synergistic activity (2.68 x 10(2) CFU/ml) after 24 hours' incubation, but lost antibacterial activity after 48 hours. In conclusion, PAPM in combination with VCM showed synergistic effects on CRB-resistant MRSA. This combination therapy should be evaluated for the treatment of MRSA infection in patients with renal dysfunction.

[Pharmacokinetics of cefmenoxime in renal-failure patients undergoing continuous arteriovenous hemofiltration].

We investigated the pharmacokinetics of cefmenoxime (CMX) administrated to renal-failure patients undergoing continuous arteriovenous hemofiltration (CAVH). CAVH was carried out with a filter (0.5 m2) employing a PAN-50P (hollow fiber type) made of polyacrylonitrile membrane, with a blood flow rate of 100 ml/min and a filtration rate of 1,200 ml/hr. At 5 and 300 minutes after the CMX administration, the concentrations of CMX in the serum were 126.8 mg/L and 31.5 mg/L, respectively. The T1/2 beta was 3.55 hours. In 300 minutes after the administration of CMX, the total amount of CMX contained in the filtrate corresponded to 11.6% of the administered dose.

[Pharmacokinetics of cefotiam in patients undergoing continuous ambulatory peritoneal dialysis].

The pharmacokinetics of cefotiam (CTM) was investigated in 7 patients undergoing continuous ambulatory peritoneal dialysis (CAPD). One gram of CTM was infused either intravenously (i.v. group) or intraperitoneally (i.p. group). In the i.v. group, the serum concentration of CTM at 6 hours after infusion was 25.9 mg/L and the half-life value was 5.09 hours, while the peak value of CTM in dialysate was 12.4 mg/L. In the i.p. group without peritonitis, the dialysate concentration of CTM at 6 hours after infusion was 108.6 mg/L. The serum concentration at 15 minutes after infusion was 3.0 mg/L, the corresponding peak value was 14.0 mg/L at 4 and 6 hours after infusion.

[In vitro combination effect of vancomycin and carbapenems against carbapenem-resistant MRSA].

We determined in vitro combined effects of vancomycin (VCM) plus carbapenems (CRBs) on 12 methicillin-resistant Staphylococcus aureus (MRSA) which are resistant to CRBs. Combinations of VCM plus imipenem (IPM) and VCM plus panipenem (PAPM) and VCM plus meropenem (MEPM) indicated synergistic effects, fractional inhibitory concentration (FIC) indices of < or = 0.05, against 67%, 75%, 67% of the strains, respectively. Against forty two percent of strains tested, 1 MIC of VCM was equal to 1 MBC, and similarly, IPM, PAPM and MEPM had 1 MIC = 1 MBC against 42%, 67% and 75% of the strains tested, respectively. Combinations of VCM plus IPM and VCM plus PAPM and VCM plus MEPM showed synergistic effects, hence a fractional bactericidal concentration (FBC) index of < or = 0.50, against 42%, 50%, 75% of the strains, respectively, and the combination of VCM plus MEPM was most synergistic. These results suggest that combination therapy of VCM with CRB is useful for the treatment of MRSA infection in patients with renal dysfunction.

[Pharmacokinetics of cefodizime in patients undergoing hemodialysis].

The object of this study was to establish the most effective regimen of cefodizime (CDZM) for patients with chronic renal failure undergoing hemodialysis (HD). T 1/2 beta of CDZM upon 1 g intravenous administration was 3.50 +/- 0.72 hours in an on-HD group, and it was 11.26 +/- 3.89 hours in an off-HD group. When CDZM was administered consecutively at a dose of 1 g or 2 g only after HD, the serum concentration of CDZM was maintained at levels sufficient to exert antibacterial activity, and no tendency for accumulation was observed. The most effective regimen of CDZM to HD patients, therefore, has been that in which concluded to administration was done only after completion of HD, in a dose of 1 g for mild infections and that of 2 g for severe infections.

[Effect of vacuum cleaning of room floors and bed clothes of patients on house dust mites counts and clinical scores of atopic dermatitis. A double blind control trial].

By a randomized double blind control trial we studied the effect of vacuum cleaning of room floors, mattresses and quilts for twelve months on clinical symptoms and laboratory data of atopic dermatitis patients. All patients used the identical new vacuum cleaners. Thirty patients (3-12 years of age) with relatively stable skin conditions were randomly allocated to either of the following two groups. In the monitor group we visited patient's home every three weeks and mite specialists cleaned drastically the room floors, mattresses and quilts and the patient continued to clean in the same way in-between. In the control group we visited similarly but the cleaning was made insufficiently which was also followed by the patient. But, at 2 occasions (the first and the last visits), cleaning was made drastically also in the control group. Thus the mite numbers were counted precisely at the start and the end of the experiment both in the monitor and control groups. Each patient was seen every six weeks by the same doctor and estimated of his symptoms using our unique scoring system (Fig. 1). At the start and the end of the study, total IgE and specific IgE antibodies to house dust mites in the serum were evaluated. The monitor group showed a tendency to count smaller number of mites than the control group after a year, when there was a significant difference only in quilts. However, a statistically significant decrease in the mite counts was observed only in room floors and not in mattresses and quilts both in the monitor and control groups (Fig. 2). Clinical scores after a year significantly improved only in the monitor group and not in the control group (Fig. 3). Serum IgE value and specific antibody titer to house dust mites were not changed significantly after the trial in both groups. As a conclusion, vacuum cleaning of the patient's room improved the clinical symptoms of atopic dermatitis but this could not be related to the reduction of house dust mite number.

[Dry cough in the elderly patients treated with angiotensin converting enzyme inhibitor].

Since dry cough has recently been recognized as a side effect of angiotensin converting enzyme (ACE) inhibitors employed in the treatment of hypertension or congestive heart failure, the incidence of dry cough in elderly patients receiving ACE inhibitors was investigated. There were 237 out-patients on either captopril, enalapril, or delapril, in August and November 1989. Questionnaires concerning dry cough and smoking were completed by 184 patients. Patients either less than 50 years of age, or with chronic pulmonary disease were excluded. The remaining 168 patients, 63 males, 105 females, with a mean age of 73 years were analyzed for the incidence of a dry cough in relation to age, sex, smoking, and type of drugs. The overall incidence of a dry cough was 21/168 (12.5%), 7/63 (11.1%) for males and 14/105 (13.3%) for females, and was less frequent with advancing age; in the 51-60 age group 4/11 (36.4%), in the 61-70 age group 5/39 (12.8%), in the 71-80 age group 9/75 (12.0%), in the 81-90 age group 3/40 (7.5%), in the 91- age group 0/3 (0%). Enalapril showed significantly higher incidence of dry cough than captopril (16/93, 17.2% vs 7/88, 8.0%, p less than 0.05). Delapril showed an incidence 4/11, 36.4%, however, 9 out of the 11 patients who were given delapril had had a history of a dry cough with captopril or enalapril, and in 4 out of these 9 patients the dry cough disappeared by replacement of captopril or enalapril by delapril.(ABSTRACT TRUNCATED AT 250 WORDS)