Antisense src expression inhibits proliferation and erythropoietin-induced erythroid differentiation of K562 human leukemia cells

We constructed a recombinant plasmid which expresses antisense src RNA in human cells and used it as a tool for investigating the role of pp60c-src in proliferation and differentiation of K562 human leukemia cells. In erythropoietin (EPO)-responsive cells, EPO induces rapid tyrosine phosphorylation of several cellular proteins including EPO receptor (EPOR) although EPOR has no tyrosine kinase domain. Here we show that antisense src RNA expression suppresses pp60c-src synthesis in the recombinant plasmid-transfected K562 cells, reduces the proliferation and inhibits hemoglobin synthesis and glycophorin A expression promoted by EPO in K562 cells. These findings suggest that pp60c-src plays crucial roles in the proliferation and EPO-induced erythroid differentiation of K562 cells.

Antisense src expression inhibits U937 human leukemia cell proliferation in conjunction with reduction of c-myb expression

To elucidate the role of pp60c-src in U937 human monoblastoid leukemia cell proliferation, recombinant plasmids containing the src gene or myb gene, which could produce antisense src or antisense myb RNA after dexamethasone treatment, were constructed and transfected into U937 cells (U937-ASRC, U937-AMYB). pp60c-src synthesis in U937-ASRC was diminished by the third day after induction of antisense src RNA and the cell proliferation was reduced, furthermore, the amount of p75c-myb was significantly decreased by the third day. p75c-myb synthesis in U937-AMYB was diminished by the second day after induction of antisense myb RNA and the cell growth was significantly inhibited but the amount of pp60c-src in U937-AMYB was not reduced. These results suggest that a decrease in the amount of pp60c-src leads to an inhibition of p75c-myb expression and subsequent reduction in the U937 cell proliferation.

A comparative study of the solution structures of tachyplesin I and a novel anti-HIV synthetic peptide, T22 ([Tyr5,12, Lys7]-polyphemusin II), determined by nuclear magnetic resonance

The solution structure of tachyplesin I, which was isolated from membrane acid extracts of the hemocytes from the Japanese horseshoe crab (Tachypleus tridentatus), was determined by nuclear magnetic resonance (NMR) and distance geometry calculation. Tachyplesin I takes an antiparallel beta-sheet structure with a type-II beta-turn. Recently, among more than 20 synthetic peptides associated with tachyplesin and its isopeptide (polyphemusin), we found that a novel compound, which we designated as T22 ([Tyr5,12, Lys7]-polyphemusin II), strongly inhibited the human immunodeficiency virus (HIV)-1-induced cytopathic effect and viral antigen expression. The solution structure of T22 was investigated using NMR, and its secondary structure was confirmed to be similar to that of tachyplesin I. The anti-parallel beta-sheet structure and the several amino-acid side chains on the plane of the beta-sheet of T22 are thought to be associated with the expression of anti-HIV activity.

Carboxyl-terminal heparin-binding fragments of platelet factor 4 retain the blocking effect on the receptor binding of basic fibroblast growth factor

Platelet factor 4 (PF-4) blocks the binding of basic fibroblast growth factor (bFGF) to its receptor. In the present study, we constructed carboxyl-terminal fragments, which represent the heparin-binding region of the PF-4 molecule, and examined whether these synthetic peptides retain the blocking effects on the receptor binding of bFGF. Synthetic peptides inhibited the receptor binding of bFGF. Furthermore, they inhibited the migration and tube formation of bovine capillary endothelial cells in culture (these phenomena are dependent on endogenous bFGF).

Long-term serum lipid lowering, behavior modification, and weight loss in obese women

Reduced calorie intake, changes in the composition of foods ingested, and increased physical activity are the usual initial recommended therapies for the obesity that often accompanies hypercholesterolemia and other hyperlipidemias. Collectively resulting in weight loss, these behavioral changes are known to produce short-term (< or = 7- to 9-mo) reductions in serum cholesterol and other lipids. In contrast, previous long-term (> or = 1-yr) investigations fail to disclose a cholesterol-lowering effect of weight loss, although the subjects in these studies were not hypercholesterolemic. The aim of our investigation was to examine the long-term changes in serum lipids that occurred in a representative cohort of healthy obese (n = 45, body mass index mean +/- SD 39.0 +/- 8.6 kg/m2) women after they completed a 15-wk conventional behavior-modification program. The serum cholesterol level of this cohort was elevated at baseline (6.18 +/- 1.41 mM, > or = 75th percentile). At the time of follow-up (17.0 +/- 7.0 mo), there were significant decreases in body weight (-16.7 kg, p < 0.001) and reductions in serum total (-0.53 mM, p < 0.01) and low-density lipoprotein (-0.35 mM, p < 0.05) cholesterol. Serum triglyceride levels also decreased significantly (-0.38 mM, p < 0.001), and serum high-density lipoprotein levels remained unchanged; the ratio of high-density lipoprotein total cholesterol increased significantly (p < 0.05) relative to baseline levels. Multiple stepwise regression analysis indicated that the best predictor of percentage change in each respective lipid was its own baseline level.(ABSTRACT TRUNCATED AT 250 WORDS)

Body composition and surgical treatment of obesity. Effects of weight loss on fluid distribution

Obesity is associated with absolute and relative expansion of the extracellular water compartment (ECW). The effects of substantial and prolonged weight reduction on body water distribution are unknown, however. The authors studied total body water (TBW) by tritiated water dilution, ECW by 35SO4 dilution, exchangeable sodium (Na(e)) by 24Na, and total body potassium (TBK) by 40K whole-body counting in 25 severely obese women (body mass index [BMI] = 48 +/- 7 kg.m-2, mean +/- standard deviation) aged 36 +/- 8 years before and at intervals after gastric restrictive (GR; n = 12) and malabsorptive (MA; n = 13) operations for obesity. Results are compared with a control group of 26 healthy normal-weight women (BMI = 21 +/- 2). Before operation, the obese patients had absolute elevations of all water compartments compared with controls, with significantly higher ratios of Na(e) to TBK (1.17 +/- 0.13 versus 0.91 +/- 0.10; p less than 0.05) and ECW to intracellular water (ICW) (E/I = 0.82 +/- 0.17 versus 0.63 +/- 0.06; p less than 0.05). After weight loss of 52 +/- 20 kg in MA and 47 +/- 19 kg in GR patients (nonsignificant between groups) to a stable level 22 +/- 8 months after operation, there were statistically significant reductions in TBW, ICW, TBK, and Na(e) in both groups, but a significant reduction in ECW only after GR. Adjusting for preoperative weight, duration of follow-up, and rate of weight loss, E/I was greater after MA than GR (1.09 +/- 0.25 versus 0.82 +/- 0.14; p less than 0.05). The elevated preoperative E/I ratio did not normalize with weight loss after surgery, and the response was related to the type of operation. The finding remains to be explained although the increased E/I after MA may reflect mild protein-calorie malnutrition not detectable in the blood. The persistence of elevated E/I with significant weight loss after GR might imply an intrinsic or irreversible imbalance of fluid distribution in obese patients.

Differences in skeletal muscle and bone mineral mass between black and white females and their relevance to estimates of body composition

This study tested the hypothesis that black females have an increase in skeletal muscle and bone mineral mass compared with white females matched for age (+/- 5 y), weight (+/- 2 kg), height (+/- 3 cm), and menstrual status. Conventional [underwater weighing, whole body 40K counting (WBC), 3H2O dilution] and newly developed (dual-photon absorptiometry) techniques were used to provide ethnicity-independent estimates of body composition in 28 pairs of matched subjects. Black females had greater appendicular skeletal muscle (P less than 0.001), bone mineral (P less than 0.001), and total body potassium (TBK) (P = 0.05) compared with white females. Two classic coefficients used in body composition research [density of fat-free mass (FFM) for underwater weighing and TBK/FFM for WBC] differed significantly (P less than 0.05) between black and white females; currently applied coefficients underestimated fat in black females. This study confirms that black and white females differ in body composition and that errors in fat estimates occur when ethnicity is not accounted for in body composition models.

Relative expansion of extracellular fluid in obese vs. nonobese women

There is a conflict in previous studies with regard to the relation between adipose tissue mass and total body fluid distribution. This study tested the hypothesis that obesity is accompanied by an increase in the extracellular-to-intracellular fluid ratio above that observed in nonobese subjects. Extracellular fluid was evaluated in obese (n = 39) and nonobese (n = 26) healthy women, using two different dilution volumes, 35SO4 [extracellular water (ECW)] and 24NaCl [exchangeable sodium (Nae)]. Intracellular water (ICW = 3H2O dilution volume-ECW) and total body potassium (TBK; 40K whole body counting) were assumed to represent intracellular fluid. Two independent markers of relative fluid distribution were formulated as ECW/ICW and Nae/TBK. Obese and nonobese women were of similar age and height but differed in body weight and TBW by 67.7 kg and 12.9 liters, respectively. The obese women had significantly larger absolute ECW, Nae, ICW, and TBK compared with the nonobese women (all P less than 0.001). The ratios ECW/ICW and Nae/TBK were significantly higher in obese vs. nonobese women and were highly correlated with each other (r = 0.54, P less than 0.001) in the pooled group of subjects. Fluid volumes are thus increased in obese women, and the expansion is relatively greater for the extracellular compartment. These results have implications in the study of human body composition and may also account in part for the fluid-overload states that often accompany severe obesity.

Chemical and elemental analysis of humans in vivo using improved body composition models

Six chemical compartments [water, protein, mineral (osseus and cellular), glycogen, and fat] consisting of 11 elements (N, C, Ca, Na, Cl, K, H, P, O, S, and Mg) comprise greater than or equal to 99% of body weight in living humans. The combination of three neutron-activation systems, whole body 40K counting, and 3H2O dilution at Brookhaven National Laboratory now potentially makes it possible to quantify greater than or equal to 96% of the chemical and elemental determinants of body weight in vivo. The aims of the present study were 1) to develop 6- and 11-compartment chemical and elemental models, respectively, and 2) to evaluate these models in a group of 20 healthy adults. Results demonstrated that body weight estimated from either chemical or elemental components was highly correlated with (both r = 0.97, P less than 0.001) and on average differed by less than 4% from actual body weight. The compartmental results obtained using the chemical model were also evaluated by comparing calculated and actual body density (Db) estimated by underwater weighing. Calculated Db [1.041 +/- 0.017 (SD) g/ml] agreed closely and was highly correlated with actual Db (1.039 +/- 0.018 g/ml; r = 0.82; P less than 0.001). Hence a near-complete chemical and elemental analysis of living human subjects is now possible and, with potential future refinements, represents an important opportunity to quantify the effects of gender, aging, and ethnic status on body composition.

Body composition in humans: advances in the development of multicompartment chemical models

Until recently it was practical to divide body weight into only two or three chemical compartments in living subjects due to an inability to quantify directly total body mineral, protein, and fat in vivo. The six-compartment chemical model is now the cornerstone of research in human body composition. Advanced technologies, including neutron activation analysis systems and dual photon absorptiometry, now enable investigators to extend body composition estimates and to construct near-complete chemical models in vivo. These new or refined approaches will advance our knowledge of human body composition and will also improve our accuracy in calibrating simpler epidemiologic and bedside body-composition techniques.

[Clinical experience with extracorporeal shock wave lithotripsy MFL-5000 for urinary stone]

A Dornier MFL 5000, a new generation extracorporeal shock wave lithotripter, was installed in our hospital and the first Japanese clinical experience has been collected between July and November in 1989. We report our experience with the first 35 patients with 45 stones who were treated in 42 treatments using ESWL. We followed up 3 weeks. No invasive anesthesia was performed except 2 cases of epidural anesthesia. A double J catheter was installed in 2 patients, a ureteral catheter in 4 patients, and PNL was performed in 2 patients before ESWL. We did not use a PNL or a TUL in the postoperative treatment. In the 3 week followed up period, 29 patients (82.9%) were completely free from stone fragments. No serious complications were observed after ESWL. We conclude that the DORNIER MFL 5000 is effective for renal and ureteral stones without serious complications.

Purification and characterization of a coagulant enzyme, okinaxobin I, from the venom of Trimeresurus okinavensis (Himehabu snake) which releases fibrinopeptide B

A coagulant enzyme, named okinaxobin I, has been purified to homogeneity from the venom of Trimeresurus okinavensis (Himehabu) by chromatographies on Sephadex G-100 and CM-Toyopearl 650M columns. The enzyme was a monomer with a molecular weight of 37,000 and its isoelectric point was 5.4. The enzyme acted on fibrinogen to form fibrin clots with a specific activity of 77 NIH units/mg. Fibrinopeptide B was released at a rate much faster than fibrinopeptide A. The enzyme exhibited 2 to 3 times higher activity toward tosyl-L-arginine methyl ester and benzoyl-L-arginine p-nitroanilide than bovine thrombin. The esterase activity was strongly inhibited by diisopropylfluorophosphate and phenylmethanesulfonyl fluoride, and to a lesser extent by tosyl-L-lysine chloromethyl ketone, indicating that the enzyme is a serine protease like thrombin. The N-terminal sequence was highly homologous to those of coagulant enzymes from T. flavoviridis and Bothrops atrox, moojeni venoms which preferentially release fibrinopeptide A. In order to remove most, if not all, of the bonded carbohydrates, the enzyme was treated with anhydrous hydrogen fluoride (HF), thereby reducing the molecular weight to 30,000. The protein contained approximately 260 amino acid residues when computation was based on this value. The HF-treated enzyme retained about 50% of the clotting and esterolytic (TAME) activities and preferentially released fibrinopeptide B from fibrinogen. The carbohydrate moiety is not crucial for enzyme activity but might be necessary for eliciting full activity.

Mode of action of the gramicidin S analogs lacking hydrophilic amino acid residues on biomembranes

The gramicidin S analog lacking basic ornithine residues, cyclo(-Val-Ala-Leu-delta Phe-Pro-)2 (where delta Phe represents alpha, beta-dehydrophenylalanine), increased the K+ permeability of human erythrocytes and Staphylococcus aureus similarly to the parent gramicidin S. This analog altered the normal discoid shape of human erythrocytes to an invaginated form. The direction of the shape change was opposite to the case of gramicidin S causing crenated cells. We suppose that the analog accumulated predominantly into the inner half monolayer of membrane and destabilized the membrane structure, resulting in a break in the membrane.

Revised structure of the peptide lactone antibiotic, TL-119 and/or A-3302-B

The peptide lactone antibiotic TL-119 and/or A-3302-B was chemically synthesized in order to confirm the proposed structure. The synthetic compound was different from both natural TL-119 and A-3302-B in their physicochemical properties and in biological activity. Re-examination of the configuration of the constituent amino acid residues in natural TL-119 and/or A-3302-B indicated that natural TL-119 and A-3302-B contains D-aThr instead of the original L-Thr. We tentatively propose a revised structure for TL-119 and/or A-3302-B.

Opioid activities of morphiceptin-like peptides latent in various natural proteins

The Tyr-Pro-Phe peptide sequence, an N-terminal tripeptide fragment of opioid peptide morphiceptin, was searched on the database SEQDB (Peptide Institute, Osaka). More than 30 proteins were drawn in a list with 15 amino acid varieties at the position adjacent to Phe. Seven morphiceptin-like peptides with the H-Tyr-Pro-Phe-Xxx-NH2 sequence, where Xxx denotes the selected amino acids (Ala, Asp, Gly, Gln, Lys, Thr and Tyr), have been synthesized. Together with the side-chain protected analogs [Asp(OBzl), Lys(Z), and Thr(Bzl)], they have been evaluated for opioid activities. For the mu opioid receptors to which morphiceptin binds specifically and selectively, analogs with Xxx = Asp, Lys, Ala, Thr, Gln, Tyr and Gly showed a considerably weaker binding affinity than morphiceptin. In contrast, the Thr(Bzl) derivative demonstrated an affinity ten times greater than morphiceptin. Because of an extremely weak affinity for the delta receptors, its mu-selectivity became very high (260-fold). The present results and the increased activity of [Val4]morphiceptin (Sakaguchi et al., 36) indicate that the mu receptors tolerate the hydrophobic or aromatic residue at the site corresponding to position 4 of morphiceptin. When the circular dichroism (CD) spectra are compared between active and inactive analogs, no significant difference is found in both water and methanol. This suggests that the activity of morphiceptin analogs with the Tyr-Pro-Phe sequence is mainly determined by the structural characters of the amino acid residue in position 4 rather than by the molecular conformation. The results suggested a possible formation of morphiceptin-like peptides in various protein digests.

[Clinical evaluation of sultamicillin in the treatment of urinary tract infections]

Sultamicillin, a new semisynthetic oral beta-lactam antibiotic, was evaluated for its antibacteria susceptibility and clinical efficacy against urinary tract infection (UTI), and the following results were obtained. The sensitivity of sultamicillin (SBTPC) on 518 strains of clinical isolates from the urine were tested and compared to ampicillin (ABPC). S. aureus, S. epidermidis, Enterococcus sp., Streptococcus sp., E. coli, K. pneumoniae, K. oxytoca, P. mirabilis, M. morganii and Acinetobacter sp. showed high sensitivity to SBTPC. The antibacterial activity of SBTPC was superior to that of ABPC in most strains and especially more superior in beta-lactamase producing strains. The clinical effectiveness rate on a total of 15 patients with acute uncomplicated cystitis was 93.3% and the eradication rate of causative organisms was 93.3%. On 15 patients with chronic complicated UTI, the clinical effectiveness rate was 73.3% and eradication rate was 76.5%. Side effects (diarrhea) were observed in 3 cases, but this symptom was not severe and soon disappeared. Abnormal laboratory data due to the drug were not observed.

A clinical study of total cystectomy for transitional cell carcinoma of the urinary bladder

Fifty six patients with transitional cell carcinoma of the urinary bladder were treated by total cystectomy from January, 1979 through December, 1988. A retrospective study was conducted on 52 patients on whom prognosis could be followed up. There were 40 men and 12 women (male to female ratio: 3.3: 1), between 32 and 79 years old (mean age, 64.1 years old). The overall 1-, 3- and 5-year survival rates were 65.8%, 54.1% and 43.0%, respectively. The 5-year survival rates for patients with low grade (G, I, II) and high grade (G. III) were 41.9% and 42.7%, respectively: with no significant difference in the survival curves between the two groups. The 5-year survival rates according to histopathological stage were 78.9% for patients in low stage, 24.7% in high stage, and the difference in the survival curves between the two groups was statistically significant (P less than 0.001). The mortality in the 21 cases of the 33 high stage cases in which cisplatin was used was 42.9%, with 3- and 5-year survival rates were 53.1% and 36.8%, respectively. In the remaining 12 cases in which cisplatin was not used for post-operative chemotherapy, the mortality in the 12 cases was 83.3%, with 3- and 5-year survival rates of 25.1% and 12.3%, respectively. Thus, the patients who received post-operative chemotherapy showed a better survival rate than those who did not with a significant difference (P less than 0.05). The results of the present study suggest the usefulness of post-operative adjuvant chemotherapy in the high stage case.

[Detection of beta-lactamase-producing strains isolated from urinary tract and their drug susceptibility]

A total of 518 bacterial strains isolated from the urine of patients with various urological diseases in our Urological Department between November, 1987 and February, 1989 were studied for their beta-lactamase production and susceptibility to various antimicrobial agents was determined. beta-lactamase activity was determined by the acidometry disc method. There were 241 gram-positive cocci, 276 of gram-negative rods and 1 Neisseria gonorrhoeae. Thirty-four percent of the gram positive and 76.3% of gram negative rods produced beta-lactamase. S. aureus (81.3%), S. epidermidis (65.1%) in gram-positive cocci, E. cloacae (100%), S. marcescens (100%), C. freundii (100%), P. aeruginosa (97.2%), P. Rettgeri (88.9%), E. gergoviae (85.7%), K. oxytoca (84.6%), M. morganii (81.8%) and E. coli (69.0%) in gram-negative rods produced beta-lactamase at a higher rate. beta-lactamase produced by gram-positive cocci was entirely penicillinase, and that produced by gram-negative rods only penicillinase in 4.0%, only cephalosporinase in 44.2% and both in 25.4%. In S. aureus and S. epidermidis, the isolated rate of strains resistant to ampicillin (p less than 0.01) and piperacillin (p less than 0.05) in the beta-lactamase producing strains was significantly higher than that in the beta-lactamase non-producing strains. In E. coli, the isolation rate of strains resistant to ampicillin and piperacillin in the penicillinase-producing strains was significantly higher than in the penicillinase non-producing strains (p less than 0.01). But both cephalosporinase-producing strains and beta-lactamase non-producing strains showed high susceptibility to cephalothin. These results suggest that the penicillinase might present a clinical problem in the treatment of urinary tract infections by S. aureus, S. epidermidis and E. coli.

Specific inhibitory conformation of dipeptides for chymotrypsin

Based on the analyzed conformation of a chymotrypsin inhibitor H-delta Phe-Phe-OMe, we have designed a series of diastereomeric phenylalanylphenylalanine methyl esters and derivatives as possible inhibitors. Among the peptides synthesized, H-D-Phe-L-Phe-OMe was found to be very resistant to chymotrypsin in spite of its L-Phe-OMe structure at the C-terminus. It inhibited the enzyme fairly strongly and competitively with Ki = 9.0 x 10(-5) M in the assay using Ac-Tyr-OEt as a substrate. The measurements of the NOEs in high-resolution 1H-NMR analyses indicated the presence of the hydrophobic core built by the intramolecular interaction between the D-Phe-phenyl and ester-methyl groups. It was suggested that this core interacts with the chymotrypsin S2 site (Trp215) and Phe2 with the S1 site. The backbone structure of this dipeptide was assumed to be in an inhibitory conformation that fits the active center of the enzyme.

Relationships between serum cholesterol and obesity: a field study on nutritional background of hypercholesterolemia

1. Serum cholesterol levels in Japan were unrelated to total fat intake and its quality. 2. A significant positive correlation was found between serum cholesterol level and BMI, and the total energy intake was significantly higher in hypercholesterolemic group than in normocholesterolemic group. 3. Hypercholesterolemia seems to occur in the background of accumulation of body fat due to relative excess of energy intake in Japan.

Design and synthesis of dimeric analogs of neurokinin A and B: effect of dimerization of COOH-terminal heptapeptides on receptor selection

Dimeric analogs of neurokinin A and neurokinin B COOH-terminal heptapeptides were synthesized in order to examine the effect of ligand dimerization on the receptor selection. Dimerization was carried out at the NH2-terminus of peptides with succinic acid, yielding succinyl bis[Asp-Ser-Phe-Val-Gly-Leu-Met-NH2] (D-NKA4-10) and succinyl bis[Asp-Phe-Phe-Val-Gly-Leu-Met-NH2] (D-NKB4-10). In the assay using rat vas deferens (RVD), it was found that the deletion of the NH2-terminal tripeptide from native neurokinin A or B enhances the activity 1.5- to 8-fold, resulting in formation of NK-2 receptor specific ligands NKA4-10 and NKB4-10. When dimeric analogs of these shortened peptides, namely D-NKA4-10 and D-NKB4-10, were examined in RVD and guinea pig ileum (GPI), they were fairly potent in GPI, but not in RVD. Under conditions in which the NK-1 receptors in GPI were desensitized with NK-1 specific substance P methyl ester, dimers reduced the activity drastically, while the corresponding monomers exhibited unchanged activity. These results suggest that dimerization of the COOH-terminal heptapeptide of neurokinins changes the receptor selection of peptides from NK-2 to NK-1, and that the NK-1 receptor has a structure favorable to a dimeric peptide ligand.

[Malignant mesodermal mixed tumor of the bladder: report of a case]

An 81-year-old woman was admitted to our clinic due to gross hematuria. A large bulky pedunculated mass was found in the bladder by cystoscopic examination. Subtotal cystectomy and bilateral cutaneostomy was performed on January 12, 1987. Histologically the tumor was composed of carcinomatous and sarcomatous elements. The carcinomatous element was composed fundamentally of grade 2, transitional cell carcinoma with numerous foci of squamous metaplasia. The sarcomatous element was composed of myxosarcomatous, chondro-sarcomatous pattern and non-differentiated malignant spindle cell component. Immunohistochemical examination demonstrated the presence of cytokeratin and epithelial membrane antigen in the spindle cell and more obvious carcinomatous regions, using the avidin-biotin conjugated immunoperoxidase technique. The patient died 3 months after operation. Autopsy findings showed multiple organ metastasis which were composed of carcinomatous and sarcomatous elements.

Enzyme inhibition by dipeptides containing 2,3-methanophenylalanine, a sterically constrained amino acid

Both isomers of (E)-2,3-methanophenylalanine (delta EPhe), a sterically restricted amino acid, were incorporated into peptides in order to examine their possible enzyme inhibitory activity. Both (2R,3S)- and (2S,3R)- delta EPhe-Phe(or Leu)-OMe were found to inhibit effectively the hydrolysis of Ac-Tyr-OEt by chymotrypsin in a competitive manner. The ester groups of these dipeptides were quite resistant to chymotrypsin hydrolysis, and the delta EPhe-Phe peptide bond was also entirely stable. The inhibition constant (Ki) of the most potent dipeptide of H-(2R,3S)-delta EPhe-Phe-OMe was 0.16 mM at 25 degrees C. The inhibitory action of delta Phe-containing peptides was found to depend on the configuration of the delta Phe residue. The electrophilic nature of the cyclopropane ring which is conjugated with both the phenyl ring and the ester carbonyl group appears to be relevant to the inhibitory activity. Fully irreversible inactivation of chymotrypsin was achieved by its incubation with H-(2R,3S)- delta EPhe-Leu-OMe. An enzyme carboxylate group is thought to be responsible for nucleophilic attack on the cyclopropane ring leading to irreversible inactivation.

[Chronological changes in bacteria isolated from the urinary tract and their drug sensitivities]

Statistical studies were performed on bacterial strains isolated from the urine of patients with various urological disease in our Urological Department between January, 1983 and December, 1987. In 1987, sensitivity tests of antibiotics to various pathogens were carried out. From the outpatients, 5,725 bacterial strains were isolated. S. epidermidis was isolated most frequently (23.8%), followed by Enterococcus species (16.5%), E. coli (14.7%), Streptococcus species (12.6%), Proteus species (5.3%), other GNR (4.6%), P, aeruginosa (4.5%), Klebsiella species (4.4%), and others. From the inpatients, 4,747 bacterial strains were isolated. Enterococcus species was isolated most frequently (23.1%), followed by S. epidermidis (18.7%), Fungi (12.9%), P. aeruginosa (8.0%), other GNR (6.8%), Streptococcus species (5.4%), Enterobacter species (4.8%), E. coli (4.1%), S. aureus (4.1%) and others. Annual change of distribution of organisms indicated that S. aureus from outpatients had a tendency to increase and Streptococcus species had a tendency to decrease. Whereas from inpatients, E. coli, other GNR, Pseudomonas species and Enterobacter species had a tendency to increase, and Streptococcus species, P. aeruginosa, Proteus species and Klebsiella species had a tendency to decrease. S. epidermidis showed a high sensitivity to minocycline and cephalothin, and Enterococcus showed a high sensitivity to ampicillin and minocycline, but did not show good sensitivity to cefoperazone and latamoxef. E. coli showed a high sensitivity to all drug we tested. P. aeruginosa showed a high sensitivity to gentamycin and norflaxacin, but did not show good sensitivity to other many drugs we tested.