Enzymatic synthesis of (-)- and (+)-acetoxyhexamides and (-)- and (+)-hydroxyhexamides

The enantioselective hydrolysis of (+/-)-4-(1-acetoxyethyl)-N-(cyclohexylcarbamoyl)-benzenesulfona mides 3 with lipase Amano P from Pseudomonas sp. in a water-saturated solvent gave (R)-4-(1-hydroxyethyl)-N-(cyclohexylcarbamoyl)benzenesulfonamide 2 (39%, > 99% ee) and unchanged (S)-3 (50%, 62% ee). On the other hand, enantioselective esterification of (+/-)-2 with lipase Amano P in the presence of vinyl acetate provided (R)-3 (41%, > 99% ee) and unchanged (S)-2 (46%, 78% ee).

Cloning, expression, and chromosomal mapping of a human ganglioside sialidase

Here we report the cDNA sequence of a human ganglioside sialidase. The cDNA was isolated from a human brain cDNA library by screening with a 240 bp probe generated by polymerase chain reaction using primers based on the sequences of rat cytosolic and bovine membrane sialidases which we previously cloned. The 3.0 kb cDNA encodes an open reading frame of 436 amino acids containing a putative transmenbrane domain and an Arg-Ile-Pro and three Asp-box sequences characteristic of sialidases and showing overall 83% and 39% identities to the bovine and rat enzymes, respectively. Northern blot analysis revealed high expression in skeletal muscle and testis, but low level in kidney, placenta, lung, and digestive organs. Transient expression of the cDNA in COS-1 cells resulted in a 130-fold increase in sialidase activity compared to the control level, and the activity was found to be almost specific for gangliosides. Fluorescent in situ hybridization allowed the human sialidase gene localized to chromosome 11 at q 13.5.

[Influence of dexamethasone on the clinical course of bacterial meningitis in children. Especially on secondary fever. Experiences in 27 institutions]

Of pediatric patients with purulent meningitis seen at the institutions listed in the title page of this paper between 1986 and 1994, 93 patients treated with antibiotics and dexamethasone (DXM) were compared with 91 patients treated with antibiotics alone. The patients receiving antibiotics with dexamethasone achieved overall improvement in inflammatory symptoms and signs and cerebrospinal fluid findings and became afebrile significantly earlier than those receiving antibiotics alone. However, some of the patients became febrile again. The secondary fever rate for the DXM group was much higher than that for the antibiotic alone group (p < 0.0001). In most of the rebounded cases, the body temperature rose above 38 degrees C and remained elevated for 2-4 days. Cerebrospinal fluid (CSF) was cultured daily in 54 and 32 patients receiving antibiotics with and without DXM, respectively. Although this study was not a controlled study in a strict sense, these patients compared. In both groups, the CSF became mostly culture-negative within 48 hours. In a few patients receiving DXM, however, it became culture-negative after 72 hours or longer. DXM caused an adverse effect in a patient with meningitis caused by Streptococcus pneumoniae. The adverse effect was mild gastrointestinal bleeding, which recovered spontaneously. From the findings described above, the use of DXM combined with antibiotic therapy was considered to accelerate the relief from fever and improvement of inflammatory symptoms and signs and CSF findings. The body temperature rose again in more than half of the patients receiving DXM, but fell to normal spontaneously without treatment. The elevation doubtlessly could not be distinguished from recurrence of the meningitis itself or complications. It seems to be likely that no treatment but careful observation is required even if the fever recurs as far as the CSF findings showed favorable progress with excelluent general conditions. When DXM is given, it is essential that CSF tests and culture are repeated during the early stages and the progress is monitored carefully.

[Emphysematous pyelonephritis complicated with diabetes mellitus: a case report]

A 46-year-old woman with diabetes mellitus was admitted to our hospital due to lower right abdominal pain. Urinalysis did not show marked pyuria. Abdominal computed tomography showed an abnormal gas shadow in the right renal parenchyma. A diagnosis was made of right emphysematous pyelonephritis. Despite aggressive supportive therapy, the patient's condition worsened. Therefore, right nephrectomy was performed. The next day her general condition was markedly improved. We reviewed 122 cases of emphysematous pyelonephritis including our case in the Japanese literature, and discussed its etiology, symptomatology, choice of treatment and prognosis.

[Detection of anti-Chlamydia trachomatis antibody by means of enzyme immunoassay using synthetic peptide antigen]

Newly developed diagnostic kits for the detection of Anti-Chlamydia trachomatis, Peptide-Chlamvdia (LOY: Meiji Milk Products Co., Ltd., Tokyo; for IgG and IgA), were evaluated using the microimmunofluorescence assay (MIF) as the gold standard. These results were also compared to results of testing by Sero-IPALISA and immunoblot (I-B). Detection by LOY in based on enzyme immunoassay with synthetic peptides as the antigen. Thirty serum samples from pediatric patients and 130 serum samples from gynecology patients were used. All 26 pediatric samples that were positive for Chlamydia pneumoniae IgG antibody tested negative with LOY, indicating that the presence of the antibody against C. pneumoniae did not affect the assay by LOY. For 90 gynecological samples, the total, the positive and the negative agreement rates for IgG were quite high; i.e. 87.8%, 90.0% and 70.0% (LOY vs MIF), 85.6%, 85.0% and 90.0% (Sero-IPALISA vs MIF), and 92.0%, 94.9% and 70.0% (I-B vs MIF), respectively. On the other hand, many cases of MIF (-) and LOY (+) discrepancy were seen in IgA detection. In order to better understand the basis for such disagreement. 34 serum samples were collected from patients whose cervical samples were negative for the Chlamydia group antigen based on the assay with IDEIA-Chlamydia. They were then assayed by MIF and LOY. The total, the positive and the negative agreement rates for IgG were 91.2%, 100% and 90.9%, while the total and the negative agreement rates for IgA were 88.2% and 88.2% (there were no IgA positive cases). Furthermore, 6 serum samples (1 case of MIF (+) LOY (+) and 5 cases of MIF (-) LOY (+)) were provided to determine whether LOY detects C. trachomatis specific IgA antibody. Increasing amounts of C. trachomatis serovar L2 were added to the serum samples resulting in a progressive decrease in their reactivity in the LOY assay. These results lead us to speculate that LOY can reveal even low levels of C. trachomatis specific IgA antibody. In conclusion, LOY can be used as an useful kit for detecting C. trachomatis antibody.

Cell-cycle-dependent and ATM-independent expression of human Chk1 kinase

Checkpoint genes cause cell cycle arrest when DNA is damaged or DNA replication is blocked. Although a human homolog of Chk1 (hChk1) has recently been reported to be involved in the DNA damage checkpoint through phosphorylation of Cdc25A, B, and C, it is not known at which phase(s) of the cell cycle hChk1 functions and how hChk1 causes cell cycle arrest in response to DNA damage. In the present study, we demonstrate that in normal human fibroblasts (MJ90), hChk1 is expressed specifically at the S to M phase of the cell cycle at both the RNA and protein levels and that it is localized to the nucleus at this time. hChk1 activity, as determined by phosphorylation of Cdc25C, is readily detected at the S to M phase of the cell cycle, and DNA damage induced by UV or ionizing radiation does not enhance the expression of hChk1 or its activity. Furthermore, hChk1 exists in an active form at the S to M phase in fibroblasts derived from patients with ataxia telangiectasia (AT) which lack the functional AT mutated (ATM) gene product, suggesting that hChk1 expression is independent of functional ATM. Taken together with the findings that phosphorylation of Cdc25C on serine 216 is increased at the S to M phase, it is suggested that at this particular phase of the cell cycle, even in the absence of DNA damage, hChk1 phosphorylates Cdc25C on serine 216, which is considered to be a prerequisite for the G2/M checkpoint. Thus, hChk1 may play an important role in keeping Cdc25C prepared for responding to DNA damage by phosphorylating its serine residue at 216 during the S to M phase.

Promoting effects of intravesical instillation of saline on bladder lesion development in rats pretreated with N-butyl-N-(4-hydroxybutyl) nitrosamine are inhibited by bacillus Calmette-Guerin

The promoting effects of intravesical instillation of saline and the efficacy of bacillus Calmette-Guerin (BCG) for prophylaxis of bladder carcinogenesis were assessed. Rats were given 0.05% N-butyl-N-(4-hydroxybutyl)nitrosamine (BBN) for 10 weeks; they were then given 6 weekly intravesical instillations of BCG, saline or distilled water starting 1 week or 15 weeks after the BBN treatment. At 32 weeks, both the incidences and numbers of bladder cancers were elevated in animals receiving the saline. An exception was the early phase BCG group. Significant increases in tumor size were also noted for the saline, but not the distilled water group. The results indicate that intravesical instillation of saline promotes urinary bladder carcinogenesis. However, the inhibitory influence of BCG was suggested if administered at the early, but not the late phase, of carcinogenesis.

Stromelysin promoter 5A/6A polymorphism is associated with acute myocardial infarction

BACKGROUND

Rupture of the fibrous cap of an atherosclerotic plaque is a key event that predisposes to acute myocardial infarction (AMI). Matrix metalloproteinases (MMPs) may contribute to weakening of the cap, which favors rupture. Stromelysin, a member of MMP family, is identified extensively in human coronary atherosclerotic lesions. It can degrade most of the constituents of extracellular matrix as well as activating other MMPs, which suggests that it may play an important role in plaque rupture. Recently, a common variant (5A/6A) in the promoter of the stromelysin gene has been identified. The 5A/6A polymorphism could regulate the transcription of the stromelysin gene in an allele-specific manner.

METHODS AND RESULTS

To investigate the relation between the 5A/6A polymorphism in the promoter of the stromelysin gene and AMI, we conducted a case-control study of 330 AMI patients and 330 control subjects. The prevalence of the 5A/6A+5A/5A genotype was significantly more frequent in the patients with AMI than in control subjects (48.8% vs 32.7%, P<0.0001). In logistic regression models, the odds ratio of the 5A/6A+5A/5A was 2.25 (95% CI, 1.51 to 3.35). The association of 5A/6A polymorphism with AMI was statistically significant and independent of other risk factors.

CONCLUSIONS

The 5A/6A polymorphism in the promoter of the stromelysin gene is a novel pathogenetic risk factor for AMI.

[Effect of antibiotics and antibody on phagocytic bactericidal activity of polymorphonuclear neutrophils of Bordetella pertussis]

The phagocytic bactericidal activity of the polymononucler neutrophils (PMNs) that were collected from healthy volunteer with and without antibody against Bordetella pertussis was investigated. Furthermore, these activity against B. pertussis under observing penicillins or macrolides antibiotics was investigated. Although no efficacy to B. pertussis strain by the PMNs in serum without antibody, but the viable cells of B. pertussis decreased to 1/1,000 1 hr after incubation and was not detected after 4 hrs. In particular, the viable cells of B. pertussis by the PMNs in serum with antibody was markedly reduced when azithromycin was present. These results suggests that the synergistic action of macrolide antibiotics and antibody-mediated phagocytic bactericidal activity on B. pertussis may have clinical relevance.

Identification of mRNA for 5-HT1 and 5-HT2 receptor subtypes in human coronary arteries

OBJECTIVE

Although pharmacological studies have indicated that serotonin (5-HT)-evoked contraction of the human coronary artery is mediated by 5-HT1-like and 5-HT2 receptors, the gene expression of 5-HT receptors is still unclear. We examined mRNA expression of 5-HT1 and 5-HT2 receptor subtypes in human coronary arteries.

METHODS

Total RNA was extracted from human coronary arteries of 14 patients at autopsy by the guanidine method. Reverse transcription-polymerase chain reaction (RT-PCR) and ribonuclease protection assays were performed to identify 5-HT1 and 5-HT2 receptor mRNA expression in human coronary artery.

RESULTS

By RT-PCR, 5-HT1b, 5-HT2A and 5-HT2B mRNAs were detected in all of the 14 patients. 5-HT1A, 5-HT1D, and 5-HT1E mRNAs were detected in only some patients. However, neither 5-HT1F mRNA nor 5-HT2C mRNA was detected in any patient. By ribonuclease protection assay, 5-HT1B and 5-HT2A signals were detected in all patients examined, but neither 5-HT1A, 5-HT1D nor 5-HT2B signal was detected in any patient.

CONCLUSIONS

Of 5-HT1/2 receptor subtypes, 5-HT1B and 5-HT2A receptor mRNAs were predominantly expressed in human coronary arteries. Our finding provides molecular evidence that the 5-HT1B receptor may be the 5-HT1-like receptor which mediates constriction of human coronary arteries.

[Progress in diagnosis and treatment of acute coronary syndrome]

Acute coronary syndrome is caused by disruption of a coronary atherosclerotic plaque. It is recognized that the risk of plaque disruption depends more on plaque composition than on plaque size. Therefore, it is important to establish imaging techniques and clinical markers for the identification of vulnerable plaques. Intravascular ultrasound and angioscope may reveal important features of vulnerable plaques. In the near future, optical coherence tomography and intravascular thermography may further improve the characterization of plaques. Systemic markers of inflammation, such as CRP and SAA, may reflect the intensity of inflammation in the atherosclerotic lesion. Clinical observations indicate that plaques may be stabilized by lipid-lowering drugs, anti-oxidants, estrogen and Chlamydia-killing antibiotics. After plaque rupture, new generation antiplatelet and anticoagulant drugs, such as GPIIb/IIIa antagonists and low-molecular heparin, can limit the mural thrombi formation more effectively.

Association of salivary immunoglobulin A antibody and initial mutans streptococcal infection

We explored the relationship between mutans streptococcal infection and the development of salivary IgA antibody during initial colonization. Repetitive swabbing (n = 292) of the teeth of 33 children revealed that 45% became infected with mutans streptococci between 13 and 36 months of age. In contrast, mutans streptococci could not be detected in 18 children whose last sample was taken at 39-81 months of age (median age = 62 months). During the period of mutans streptococcal infectivity, immunoglobulin A (IgA) antibody to several mutans streptococcal antigens appeared in most children, whether or not infection had been demonstrated. Robust responses to mutans streptococcal components occurred during or shortly after, but not before the period of mutans streptococcal infectivity. No consistent differences were observed among the summarized patterns of response of infected and uninfected groups of children, although the IgA Western blot patterns of individual subjects were often quite distinct. For example, sets of siblings, who would be presumed to be challenged with similar maternal mutans streptococcal clonotypes, were shown to develop qualitatively different salivary IgA responses to mutans streptococcal components. These results support a discrete period for mutans streptococcal infection and may suggest that the level of maternal infection is a factor in the success of infection of the child during this period. The data also suggest that exposure to mutans streptococci is a sufficient condition for robust mucosal IgA responses to mutans streptococcal antigens during the period of infectivity and that these responses may be different, even among siblings.

Comparison of effects of ascorbic acid on endothelium-dependent vasodilation in patients with chronic congestive heart failure secondary to idiopathic dilated cardiomyopathy versus patients with effort angina pectoris secondary to coronary artery disease

Impaired endothelium-dependent vasodilation has been reported to play an important role in the pathogenesis of cardiovascular diseases such as coronary artery disease (CAD) and congestive heart failure (CHF). However, the precise mechanism of endothelial dysfunction has not been elucidated in these conditions. To evaluate the role of oxidative stress in endothelial dysfunction, the effect of antioxidant ascorbic acid on brachial flow-mediated, endothelium-dependent vasodilation during reactive hyperemia and nitroglycerin-induced endothelium-independent vasodilation was examined with high resolution ultrasound in 12 patients with CHF caused by idiopathic dilated cardiomyopathy without established coronary atherosclerosis and in 10 patients with CAD. Flow-mediated vasodilation in CHF (4.4+/-0.5%) and CAD (4.0 - 0.8%) was significantly (p <0.05) attenuated compared with that in 10 control subjects (9.6+/-0.9%). However, nitroglycerin-induced vasodilation was similar in 3 groups (13.7+/-1.3% in control, 13.9+/-1.1% in CHF, 12.7+/-1.4% in CAD). Ascorbic acid could significantly improve flow-mediated vasodilation only in patients with CAD (9.1+/-0.9%) but not with CHF (5.6+/-0.6%), and had no influence on nitroglycerin-induced vasodilation (13.6+/-1.1% in CHF, 14.0+/-1.3% in CAD). These results suggest that, in brachial circulation, augmented oxidative stress mainly leads to endothelial dysfunction in CAD but not in CHF caused by idiopathic dilated cardiomyopathy.

Significance of membrane glycoproteins in platelet interaction with oxidized low-density lipoprotein

The significance of three platelet membrane glycoproteins, (CD62p, CD63, and CD36) was studied in platelet interaction with native and copper-oxidized plasma low-density lipoproteins (LDL). Native LDL acquired platelet-activating ability only after oxidation. Flow-cytometric studies showed that CD62P and CD63 were rapidly expressed on platelets at a low concentration of oxidized LDL, indicating that they are more sensitive markers than platelet aggregation for detection of platelet activation by oxidized LDL. CD36 was found to be contributing to the binding and activation of platelets with oxidized LDL, but not to the binding of platelets with native LDL. Although the presence of oxidized LDL in plasma is known, its effect on platelet function remains to be studied.

Immunohistochemical evaluation of p53, proliferating cell nuclear antigen (PCNA) and bcl-2 expression during bacillus Calmette-Guerin (BCG) intravesical instillation therapy for superficial bladder cancers

Bacillus Calmette-Guerin (BCG) immunotherapy for superficial bladder cancer is now widespread, but non-effective cases are not uncommon and it has yet to be clarified why this is the case. In an attempt to cast light on this problem, we evaluated differences between effective and non-effective cases immunohistochemically using p53, proliferating cell nuclear antigen (PCNA), and bcl-2 antibodies. Between March 1988 and March 1996 a total of 79 superficial bladder cancer patients were treated with BCG intravesical instillation therapy after transurethral resection of bladder tumor (TUR-Bt). Of these, 19 demonstrated recurrence after the initial treatment. From the 60 remaining patients without recurrence, we randomly chose 19 additional cases and evaluated both series for p53, PCNA and bcl-2 immunohistochemical staining using formalin-fixed, paraffin-embedded tissues. For the recurrent cases, material taken prior and subsequent to BCG therapy was available for 17 of the 19 patients. Positive staining for p53 was noted for 42.1% (8/19) of both recurrent and non-recurrent cases, without any difference between the two. The rates for PCNA and bcl-2 were 52.6% (10/19) and 47.4% (9/19) in recurrent, and 36.8% (7/19) and 78.9% (15/19) in non-recurrent cases, respectively. Thus, there was a significant difference for lower incidences of bcl-2 in recurrent cases (P = 0.044). Values for p53 and bcl-2 were respectively 47.1% (8/17) and 41.2% (7/17) pre-treatment, and 52.9% (9/17) and 35.3% (6/17) post-treatment in the recurrence group. In contrast to the similarity in these results, PCNA positive cases were 52.9% (9/17) pre-treatment and 17.6% (3/17) post-treatment. These data suggest that there are differences between BCG-sensitive and BCG-resistant bladder cancers in terms of bcl-2 expression.

Molecular cloning, expression, and characterization of human bifunctional 3'-phosphoadenosine 5'-phosphosulfate synthase and its functional domains

The universal sulfonate donor, 3'-phosphoadenosine 5'-phosphosulfate (PAPS), is synthesized by the concerted action of ATP sulfurylase and adenosine 5'-phosphosulfate (APS) kinase, which in animals are fused into a bifunctional protein. The cDNA for human PAPS synthase (hPAPSS) along with polymerase chain reaction products corresponding to several NH2- and COOH-terminal fragments were cloned and expressed in COS-1 cells. A 1-268-amino acid fragment expressed APS kinase activity, whereas a 220-623 fragment evinced ATP sulfurylase activity. The 1-268 fragment and full-length hPAPSS (1-623) exhibited hyperbolic responses against APS substrate with equivalent Km values (0.6 and 0.4 microM, respectively). The 1-268 fragment demonstrated Michaelis-Menten kinetics against ATP as substrate (Km 0.26 mM); however, full-length hPAPSS exhibited a sigmoidal response (apparent Km 1.5 mM) suggesting cooperative binding. Catalytic efficiency (Vmax/Km) of the 1-268 fragment was 64-fold higher than full-length hPAPSS for ATP. The kinetic data suggest that the COOH-terminal domain of hPAPSS exerts a regulatory role over APS kinase activity located in the NH2-terminal domain of this bifunctional protein. In addition, the 1-268 fragment and full-length hPAPSS were overexpressed in Escherichia coli and column purified. Purified full-length hPAPSS, in contrast to the COS-1 cell-expressed cDNA construct, exhibited a hyperbolic response curve against ATP suggesting that hPAPSS is perhaps modified in vivo.

Familial hypercholesterolemia with cholesteryl ester transfer protein deficiency

A 21-year-old male was clinically diagnosed with familial hypercholesterolemia (FH) by the manifestations of hypercholesterolemia, tendon xanthoma and family history of premature coronary heart disease. Low density lipoprotein receptor gene was analyzed in attempt to determine a possible point mutation. The normal sequence was partially preserved, and the patient was genetically diagnosed as a heterozygote of FH. In addition, screening for two cholesteryl ester transfer protein (CETP) gene mutations common to Japanese revealed the patient to be a heterozygote of CETP deficiency. A complication of two influential mutations for atherosclerotic ailments was genetically ascertained.

Stretch force on vascular smooth muscle cells enhances oxidation of LDL via superoxide production

Hemodynamic forces on vasculature profoundly influence atherogenesis. We examined the effect of stretch force on the oxidation of low-density lipoprotein (LDL) by rat aortic smooth muscle cells (RASM) and superoxide production. Stretch force was imposed on RASM cultured on deformable dishes by stretching the dishes. Incubation of native LDL with static RASM for 24 h resulted in LDL oxidation as indicated by increases in thiobarbituric acid-reacting substances from 9.5 +/- 2.3 to 24.5 +/- 2.3 nmol malondialdehyde/mg. Stretch force on RASM augmented cell-mediated LDL oxidation to 149.3 +/- 17.1% concomitantly with increase in superoxide production. LDL oxidation was inhibited by superoxide dismutase or depletion of the metal ion in the culture medium, indicating that it was a metal ion-dependent and superoxide-mediated process. The enhancement of LDL oxidation by stretch force was inhibited by diphenyliodonium, indicating the involvement of the NADH/NADPH oxidase system. Our findings suggest that the increased oxidant stress induced by stretch force is one of the potential mechanisms whereby hypertension facilitates atherosclerosis.