Transcriptional analysis of the beta-galactosidase gene (pbg) in Clostridium perfringens

The mode of expression of the beta-galactosidase gene (pbg) of Clostridium perfringens was examined. The pbg gene was transcribed on a single 3.7-kb mRNA. The transcript contained a message for ORF54, located upstream of the pbg gene in the chromosome, indicating that ORF54 and the pbg gene comprise one operon (pbg operon). Expression of the pbg operon was induced by lactose at the transcriptional level. The promoter structure of the pbg operon was characterized by many palindrome structures and direct repeats, which suggests that there might be some catabolite regulation of the expression of the pbg operon in C. perfringens.

Inhibitory effects of azelastine and tranilast on leukotriene B4 and leukotriene C4 generation by rat colonic mucosa

Anti-allergic drugs such as sodium cromoglycate are known to be effective for the treatment of ulcerative colitis (UC). Because leukotriene (LT) production is considered to play an important role in the pathophysiology of UC, we examined the effect of the anti-allergic drugs, azelastine and tranilast, and the 5-lipoxygenase inhibitor, AA861, on LTB4 and LTC4 production by isolated rat colonic mucosa treated with the calcium ionophore, A23187. Preincubation of colonic mucosa with AA861 (10(-4) M) or azelastine (10(-4) M) significantly reduced AA23187-induced LTB4 (p < 0.01 and p < 0.05, respectively) and LTC4 (p < 0.01) production. Pretreatment with tranilast (10(-3) M) also significantly reduced A23187-induced LTC4 production (p < 0.05). These findings suggest that azelastine and tranilast can inhibit LT production in colonic mucosa and may be beneficial in the treatment of patients with UC.

Leukotriene B4 and C4 metabolism in small intestine mucosa of children with celiac disease

The enhanced generation of eicosanoids, including leukotrienes (LTs), may be involved in the pathophysiology of small intestine mucosal injury in patients with celiac disease. We investigated the metabolism of LTB4 and LTC4 by small intestine mucosa in patients with celiac disease by incubating biopsies of small intestine mucosa from patients and healthy subjects in media containing LTB4 and LTC4 and measuring the changes in LTB4 and cysteinyl LT concentrations in the incubation media. There was no significant degradation of LTB4 during a 60-min incubation of the small intestine mucosa from either children with celiac disease or controls. LTC4 was metabolized to LTD4 and LTE4 in a time-dependent manner by the small intestine mucosa of both patients and controls. However, the decreases in LTC4 and the increases in LTD4 and LTE4 by the intestinal mucosa from patients with celiac disease occurred more slowly than the changes observed in control experiments. Reduced catabolism of LTC4 in the small intestine mucosa due to villous atrophy may contribute to increased levels of LTC4 and may play an important role in the pathophysiology of celiac disease.

Flecainide blocks the stimulatory effect of veratridine on slowly adapting pulmonary stretch receptors in anaesthetized rabbits without changing lung mechanics

We examined the responses of slowly adapting pulmonary stretch receptors (PSRs), total lung resistance (RL) and dynamic lung compliance (Cdyn) to administered veratridine before and after pretreatment with atropine or flecainide in anaesthetized, artificially ventilated rabbits with bilateral vagotomy. Administration of veratridine (10 and 30 micrograms kg-1) caused vigorous stimulation of PSRs, resulting in a tonic discharge of receptors during both inflation and deflation, but did not significantly alter either RL or Cdyn. The veratridine-induced PSR stimulation became more prominent, as the dose of this alkaloid was increased. Pretreatment with atropine (1 or 2 mg kg-1) had no significant effect on the excitatory response of PSRs to veratridine. The veratridine-induced PSR stimulation was inhibited by treatment with flecainide (1, 2 and 3 mg kg-1), a sodium channel blocker, and this inhibition was dose-dependent. These results suggest that activation of PSRs following veratridine administration probably related to the increased influx of sodium ions into the receptive terminals but does not depend upon bronchoconstriction.

[A case of Pasteurella multocida subsp. multocida septicemia due to cat bites in liver cirrhosis patient]

A 60-year-old male who had been suffering from liver cirrhosis was admitted to our hospital with high grade fever accompanied by right chest pain. Chest X-rays revealed a moderate amount of pleural fluid suggesting pleuritis. Multocida was isolated from the blood culture as well as the pleural fluid. Antibiotic therapy was initiated according to the drug susceptibility of the isolates. Ten days treatment was effective on the cessation of both septicemia and the clinical symptoms. Since the patient had been bitten several times by his own pet cats, their mouth swabs were taken for pathogenic investigations. Serotypes of the cats' isolates coincided with that of the patient's which consequently indicated the route of infection. P. multocida is a Gram negative coccobacillary organism that resides as normal flora in the oral cavity of animals, including dogs and cats. It has been originally known to be a causative agent for hemorrhagic septicemia in domestic animals. However, recently reports of P. multocida infections in man has been increasing due to the enlargement of pet populations. Although outbreaks of septicemia is rare, it occurs most often in immunologically compromised hosts, including patients with liver cirrhosis as in this case. Therefore, it is important to initiate an urgent antibiotic therapy in such cases. Overall, it is of utmost importance to instruct immunosuppressed patients to avoid excessive exposure to animals including pets.

[Three-dimensional helical CT angiography of the abdomen]

To evaluate the quality of three-dimensional (3D) images of the abdominal vasculature acquired using enhanced helical CT, 3D reconstructions were performed for 43 examinations (38 patients). Twenty-one of 43 examinations were also reconstructed by Maximum Intensity Projection (MIP). The CT scanner employed was the Toshiba Xforce. Helical CT data were acquired using up to 20 continuous 1.5-sec rotations with an X-ray beam width of 5 mm and a couchtop movement speed of 5 to 10 mm/1.5 sec. Axial images were reconstructed at a section interval of 2 mm. Optimal protocol on enhanced helical CT was as follows: Iopamidol 300 mg I/ml was administered intravenously using a biphasic technique (3-4 ml/sec for the initial 100 ml, followed by 0.7-1.5 ml for the remaining 50 ml), and delay times of the early and late phases were 25-35 and 90 sec, respectively. Aortic branches were clearly demonstrated on early phase, while portal branches were well defined on late phase. In the visualization of abdominal vessels, 3D images were nearly equal to MIP images. However, for anteroposterior images, MIP images were superior to 3D images in quality, because 3D images had some longitudinal direction artifacts. Three-dimensional images were considered to be useful for correctly evaluating overlapping abdominal vasculatures. From the above results, 3D and MIP images of the abdominal vasculature obtained using enhanced helical CT were considered to compensate for each other.

Nucleotide sequence of the psaD gene from the thermophilic cyanobacterium Synechococcus vulcanus

The nucleotide sequence was determined for the psaD gene of a thermophilic cyanobacterium, Synechococcus vulcanus, which encoded the PsaD subunit (Subunit II) of the Photosystem I reaction center complex. Except for some differences in the peripherals, the nucleotide sequence of the gene encoding PsaD was identical to that of another thermophilic cyanobacterium Synechococcus elongatus reported previously. Relationship between these primary structures and thermostability was also discussed.

Induction of cerebral thrombosis with phenytoin in rats

BACKGROUND AND PURPOSE

This study was conducted to explore whether intra-arterial infusion of phenytoin causes cerebral ischemia and to examine the mechanism of cerebral ischemia induced by phenytoin.

METHODS

Ten rats were infused with phenytoin (150 microL, 3.75 mg) retrogradely from the left external carotid artery, followed by perfusion of carbon black transcardially. The removed brain was photographed from above, and the nonperfused area was compared with control rats (n = 10) with the use of an image analyzer. Eight animals with or without phenytoin treatment were perfusion-fixed for transmission electron microscopic analyses of cerebral vasculature. To determine the effect of tissue plasminogen activator (TPA) on phenytoin-infused rat cerebrum, 20 rats were treated with or without TPA (120,000 IU) 5 minutes after the phenytoin infusion (n = 10 each).

RESULTS

All rats suffered from respiratory distress 25 to 40 minutes after the injection and received carbon black transcardially. The nonperfused area was seen in the territory of the left internal carotid artery. Thrombi were observed from arterioles to capillaries. Under electron microscopy, endothelial cells were partially exfoliated, and the vascular lumen was obstructed by thrombi predominantly consisting of platelets. Eight rats with TPA survived more than 60 minutes, whereas only 2 rats survived without the treatment (P < .005). Nonperfused areas were 7 +/- 5% and 50 +/- 11% of cerebral surface area in rats with and without TPA treatment, respectively (P < .001).

CONCLUSIONS

Intra-arterial infusion of phenytoin results in a nonperfused area in rat cerebrum primarily due to thrombosis of arterioles and capillaries.

Vibrio trachuri sp. nov., a new species isolated from diseased Japanese horse mackerel

A new species, Vibrio trachuri sp. nov., was isolated from the cultured Japanese horse mackerel (Trachurus japonicus). These Vibrio were Gram negative, motile rods and formed yellow colonies on BTB teepol and TCBS plate, turned TSI medium to yellow and was sensitive to 150 microM O/129 (2,4-diamino-6,7-diisopropyl pteridine phosphate) like Listonella anguillarum which has been described as Vibrio anguillarum. However, the results of VP test and decarboxylation of lysine or dihydrolation of arginine suggested that these Vibrio are rather closely related to V. parahaemolyticus. DNA similarity determined by the microplate hybridization technique revealed that these Vibrio are genetically quite distant from Listonella anguillarum or V. parahaemolyticus and rather close to V. harveyi, although there was no Vibrio species which had more than 70% similarity value. From these results we propose to nominate Vibrio trachuri sp. nov. for this new Vibrio species.

Abnormal expression of heparin sulfate proteoglycan on basal lamina of muscle fibers in two Japanese patients with adhalin deficiency

We recently reported the selective reduction of the B1 subunit of laminin in two Japanese patients with adhalin deficiency. We here investigated immunohistochemically the expression of other components of the extracellular matrix (ECM), including collagen type IV, heparan sulfate proteoglycan can (HSPG), chondroitin-4-sulfate proteoglycan, decorin, and fibronectin in adhalin deficiency, compared with other types of muscular dystrophy. We found a reduction of HSPG on the basal lamina surrounding each muscle fiber in adhalin deficiency compared with HSPG in other diseases. This finding may be characteristic evidence of the disturbance of the sarcolemma-ECM interaction and the sarcolemmal instability in adhalin deficiency. Recently, a direct role of HSPG in fibroblast growth factor (FGF) signal transduction was demonstrated. Further investigation is required to determine if the dysfunction of FGF is relevant to the pathogenesis of adhalin deficiency.

[Comparative examinations of serum pepsinogen I, II and gastric area using computed radiography in the atrophic gastritis]

The relationship between serum PG I, PG II levels and extent of atrophic gastritis was examined. On 64 patients (male: 32, female: 32, 51.9 years old on average) with established diagnosis of either atrophic gastritis or normal. In the X-ray gastric examination, Fuji Computed Radiography (FCR) was used to obtain clear-cut images of the gastric area. Concerning the serum PG I level, patients in the group with atrophic gastritis showed lower levels than those of the people in the group with no atrophic change, but the variation was wide, and no definite tendency was seen in the relationship between the atrophic change and the serum PG I levels. Concerning the serum PG II level, as the atrophic change progresses, the serum PG II level tended to increase gradually. A significant reduction in the PG I/II ratio was seen in the group with atrophic changes (p < 0.01) in comparison with the group with no atrophic changes, and the PG I/II value tended to decrease. In conclusion, as a relationship between the atrophic change and the serum PG levels had a wide variation, we considered to be difficult by to measure the serum PG level to understand the presence and extent of the atrophic gastritis.

A single retroviral gag precursor signal peptide recognized by FBL-3 tumor-specific cytotoxic T lymphocytes

Several dominant T-cell receptors of cytotoxic T-lymphocyte (CTL) clones specific for FBL-3 tumor antigen were clonally amplified in mixed lymphocyte tumor cell cultures derived from an individual immune mouse. Every CTL clone analyzed had a common specificity for a single epitope in the precursor to cell membrane-associated nonstructural gag-encoded protein, Pr75gag, which can be minimally identified by nine amino acid residues, SIVLCCLCL. This epitope is located within the hydrophobic signal sequence motif that mediates translocation of the protein into the endoplasmic reticulum. These novel observations suggest that expression of Pr75gag in FBL-3 tumor cells led to the amplification of CTLs which recognize the signal sequence of the nonstructural gag-encoded glycoprotein precursor.

A radioreceptor binding assay for platelet-activating factor (PAF) using membranes from CHO cells expressing human PAF receptor

A simple and reproducible radioreceptor assay (RRA) has been developed using membranes from CHO cells which can stably express human platelet-activating factor (PAF) receptor. The CHO cells expressing the PAF receptor, termed CHO.1F8, showed a significant intracellular Ca2+ response to PAF, and the same binding properties to [3H]WEB 2086, a PAF antagonist, as reported (Kd, 13.6 +/- 1.9 nM; Bmax, 2.5 +/- 0.4 pmol/mg protein (n = 6)). A competitive binding assay was done using the CHO.1F8 cell membranes and [3H]WEB 2086. The minimum detectable dose of PAF was 0.3 nM (approximately 30 pg per well) and the assay was highly specific for PAF. This method makes it possible to handle large numbers of samples rapidly and simultaneously, since the receptor membrane is prepared in advance and the binding assay can be completed within 3 h. Using this method, we have determined the production and cell association of PAF in human neutrophils.

Marked detergents effects on safranine T-mediated photo-induced electron transfer in cytochrome P-450 1A2

Cytochrome P-450 accepts electrons from electron transfer proteins to facilitate monooxidation reactions. It is suggested that basic amino acids such as Lys and Arg on the P-450 molecular surface interact with acidic amino acids such as Glu and Asp of the electron transfer protein. Safranine T is a basic compound which mediates electron transfer with illumination. It was found with flash photolysis that an electron from photo-reduced safranine T quickly reaches the heme iron of cytochrome P-450 1A2 (P-450 1A2). The photo-induced reduction kinetics of P-450 1A2 were analyzed by the Runge-Kutta method on the second order assumption. The electron-transfer rate constant from safranine T to P-450 1A2 was 2.1 x 10(6) M-1s-1. The rate constant was remarkably increased up to 3.1 x 10(8) M-1s-1 by adding cholic acid, while that was drastically reduced down to 3.5 x 10(4) M-1s-1 by adding Emulgen 913. The electron-transfer rate of a His163-Glu mutant, which has a 40 mV lower redox potential than that of the wild type, was the same as that of the wild type in the absence of the detergents, although the reduced fraction of the mutant was 30% lower than that of the wild type. The electron-transfer rate of the mutant also changed significantly by adding the detergents in the same way as the wild type. Based on these results, together with optical absorbance and fluorescence data, we discuss the inter- and intramolecular electron-transfer mechanism of P-450 1A2.

pH dependent alterations of monoepoxides and monochlorohydrins of linoleic acid, and their existence in vivo

Some monoepoxides of linoleic acid (LA) were converted to monochlorohydrins in low-pH solutions containing chloride ions (Cl-). Conversely, monochlorohydrins of LA were converted to monoepoxides in high-pH solutions. We attempted to determine whether these monochlorohydrins and monoepoxides were produced from LA by the cytochrome-c-H2O2-and/or myeloperoxidase-H2O2-system. The existence of monoepoxides and monochlorohydrins of LA in leukocytes was confirmed by high-performance liquid chromatography (HPLC). Furthermore, leukotoxin in human leukemia cells (THP-1) was stained immunohistochemically by a monoclonal anti-leukotoxin antibody.

Expression, purification, ATPase properties, and microtubule-binding properties of the ncd motor domain

ncd is a kinesin-related motor protein from Drosophila that moves in the opposite direction along microtubules to kinesin. To learn more about the ncd mechanism, ncd motor domain (R335-K700) was expressed in Escherichia coli and its enzymatic characteristics were studied. The ncd motor domain was purified from the cell lysate by S-Sepharose chromatography, and trace amounts of contaminants were removed by passing through a MonoQ column. The yield was 20 mg from a 500 mL culture of E. coli. The purified ncd motor domain exhibited an unusual UV spectrum with a broad peak around 272-275 nm, which was at least partly due to the bound nucleotide. Upon incubation with radioactive ATP, 3H at adenine but not 32P at gamma-phosphate was retained by the protein on gel filtration, indicating it bound ADP but not ATP. Thus, like kinesin, nucleotide binding to the ncd motor domain is tight, although there is an equilibrium between the protein and free nucleotide. We also used a fluorescent ATP analogue, mantATP, for the kinetic study of ncd motor domain. MantATP was turned over by ncd motor domain slowly in the absence of microtubules, but microtubules activated the turnover to a similar extent to that of ATP. Upon incubation with ncd motor domain, the fluorescent intensity of mantATP increased at 0.005 s-1, which is likely to reflect the release of endogenous ADP and incorporation of mantATP into the protein. The fluorescence intensity of the ncd motor domain having bound mantADP, likewise, decreased upon mixing with ATP, representing the mantADP release.(ABSTRACT TRUNCATED AT 250 WORDS)

Decrease of medullary catecholaminergic neurons in multiple system atrophy and Parkinson's disease and their preservation in amyotrophic lateral sclerosis

We investigated the number of tyrosine hydroxylase (TH)-immunoreactive neurons in the C1 and A2 regions of the medulla, the sites of the baroreflex arc, in 7 patients with multiple system atrophy (MSA), 8 with Parkinson's disease (PD), 9 with amyotrophic lateral sclerosis (ALS), and 12 age-matched normal subjects to analyze the relationship between cardiovascular dysfunction and medullary catecholaminergic neurons. Orthostatic hypotension (OH) was marked in all the MSA patients and moderate in three PD patients. Three of the five ALS patients who had been on respirators showed lability of blood pressure; paroxysmal hypertension and nocturnal hypotension without compensatory tachycardia. All the MSA patients showed extremely marked decrease of TH-immunoreactive neurons in both the C1 and A2 regions. In the patients with Parkinson's disease, numerous TH-immunoreactive neurons contained Lewy bodies that were immunostained by antibody to TH. TH-immunoreactive neurons were decreased very markedly in the A2 regions of two patients with OH, and three patients without OH showed fairly marked decreases in the C1 or A2 region. In contrast, the number of TH-immunoreactive neurons in ALS was the same as in normal subjects. In MSA and some PD patients, orthostatic hypotension may partly be due to the involvement of the medullary catecholaminergic neurons. The lability of blood pressure in ALS probably is not related to the medullary catecholaminergic neurons.

Prevalence of cerebral palsy in twins, triplets and quadruplets

BACKGROUND

Twins and triplets are at higher risk of cerebral palsy than singletons. This study investigated the degree of risk for cerebral palsy in twins, triplets and quadruplets, and identified factors associated with the increased risk.

METHODS

The subjects were recruited from the Kinki University Twin and Higher Order Multiple Births Registry.

RESULTS

The subjects were 705 twins pairs (1410 twins), 96 sets of triplets (287 triplets excluding one infant death), and 7 sets of quadruplets (27 quadruplets excluding one infant death), who were born after 1977. The prevalence of cerebral palsy was 0.9% among 1410 twins, 3.1% among 287 triplets, and 11.1% among 27 quadruplets. Furthermore, the risks of producing at least one child with cerebral palsy were 1.5%, 8.0%, 42.9% in twin, triplet, quadruplet pregnancies, respectively. After adjusting for each associated factor using logistic regression, the risk of cerebral palsy was significantly associated with decrease in gestational age and asphyxia. The odds ratio indicated that infants whose gestational age was < 32 weeks were 20 times more likely to develop cerebral palsy than infants whose gestational age was > or = 36 weeks.

CONCLUSIONS

The prevalence of cerebral palsy in triplets and quadruplets was higher than that in twins. Lower gestational age was associated with a greater risk of cerebral palsy.

Cepharanthin, a multidrug resistant modifier, is a substrate for P-glycoprotein

P-glycoprotein modulators are respected to be multidrug resistance reversing agents in cancer chemotherapy. Some calcium channel blockers, calmodulin inhibitors or immunosuppressive agents have been used in clinical studies, although the dose of these drugs required to test in vitro experimental data might cause potent pharmacological effects which are not desirable in patients. By using LLC-GA5-COL150 cells that express P-glycoprotein specifically on the apical membranes, we examined the transport of anticancer drugs mediated by P-glycoprotein. Cepharanthin, a biscoclaurine alkaloid, potently inhibits the transport of vinblastine and daunorubicin, both commonly used anticancer agents. The 50% inhibitory concentration of cepharanthin on daunorubicin transport was 2.06 microM. Combined inhibitory effects on daunorubicin transport were observed when cepharanthin was used together with cyclosporin A, a potent immunosuppressive agent and P-glycoprotein modulator. Cepharanthin itself was transported by P-glycoprotein. Transcellular transport of cepharanthin across LLC-GA5-COL150 cell monolayers was saturable when its concentration was under 5 microM, and the transport was inhibited by P-glycoprotein modulators. These results indicate that cepharanthin can reverse multidrug resistance, and proper combination with other P-glycoprotein modulators could potentiate its inhibitory effect on expelling the anticancer drugs out of the cell via P-glycoprotein.

Patterns of 24 h intragastric acidity in duodenal ulcers in children: the importance of monitoring and inhibiting nocturnal acidity

The objective of this study was to compare the gastric acidity patterns of patients with duodenal ulcers and normal children. Eight patients with duodenal ulcer had their intragastric pH monitored for two consecutive 24 h periods using intragastric glass electrodes. The first 24 h period elucidated pH patterns in the absence of treatment and the second period evaluated the acid suppressive effect of 15 mg/kg of cimetidine when given in three divided doses. Results showed that the ulcer patients were hyperacidic, particularly at midnight. This finding was in marked contrast to the results obtained in the study of normal controls. The mean pH of normal children was above 3 around midnight. This phenomenon is known as intragastric pH inversion. The mean pH 3 time (the cumulative duration of the time for which gastric pH is maintained at > or = pH 3) was significantly shorter in patients with ulcers. However, pH 3 time of these patients significantly increased throughout the 24 h recording period during the daytime and at night after the introduction of cimetidine. This resulted in an induction of apparent nocturnal intragastric pH inversion for the ulcer patients. This study demonstrates the usefulness of 24 h continuous intragastric pH monitoring in children. The data showed that there was a pattern of gastric hyperacidity in pediatric ulcer patients which is clearly distinct from that of normal children, particularly in the patterns occurring at midnight. Cimetidine at 15 mg/kg per day in three divided doses was effective in suppressing secretion even at night.

Expression of thrombomodulin in esophageal squamous cell carcinoma and its relationship to lymph node metastasis

Thrombomodulin (TM) is thrombin receptor that was identified originally on the endothelium and acts as a natural anticoagulant. However, we reported previously that TM was also expressed in the squamous epithelium mainly at the intercellular bridges. In this study, we examined TM expression in the primary lesions of 106 patients with esophageal squamous cell carcinomas and in the lymph node metastatic lesions of 59 patients using immunohistochemical methods. The carcinoma tissues expressed TM mainly at the cell-cell boundaries and in the cytoplasm. When TM expression was compared between the primary and metastatic lesions in the 59 patients who had lymph node metastasis, 41 (69%) showed decreased TM expression, 18 (31%) showed no change, and none (0%) showed an increase in the metastatic lesions. Wilcoxon's signed-rank test indicated that tumor cells that were positive for TM expression were significantly rarer in the metastatic lesions than in the primary tumors (P < 0.0001). This result indicates that the decrease in TM expression is associated with metastasis of the carcinoma cells. This phenomenon is very similar to that of E-cadherin, although the structures of both molecules are quite different. The reduction of TM expression seems to play an important role in the metastatic process of esophageal cancer.