Role of rigidity and temperature in the kinetics of photodarkening in Ge(x)As(45-x)Se55 thin films

We present insightful results on the kinetics of photodarkening (PD) in Ge(x)As(45-x)Se55 glasses at the ambient and liquid helium temperatures when the network rigidity is increased by varying x from 0 to 16. We observe a many fold change in PD and its kinetics with decreasing network flexibility and temperature. Moreover, temporal evolution of PD shows a dramatic change with increasing x.

Photoinduced volume changes in amorphous selenium

We have modeled the photoinduced volume change in amorphous selenium. After photon absorption, we treated the excited electron and hole independently within the framework of the tight-binding formalism. We found covalent bond breaking in amorphous networks with photoinduced excited electrons, whereas excited holes contribute to the formation of interchain bonds. We also observed a correlated volume change of the amorphous samples. Our results provide a new and universal description, which can simultaneously explain the photoinduced volume expansion and shrinkage. This model is supported by very recent in situ surface height measurements for amorphous selenium.

High frequency of antibiotic-associated diarrhea due to toxin A-negative, toxin B-positive Clostridium difficile in a hospital in Japan and risk factors for infection

Patients hospitalized in a hospital with a high incidence of antibiotic-associated diarrhea due to toxin A-negative, toxin B-positive (A-/B+) Clostridium difficile were retrospectively investigated to determine the clinical manifestations and risk factors for infection. Of 77 Clostridium difficile isolates obtained from 77 patients during the 1-year investigation period, 30 were A-/B+ and 47 were toxin A-positive, toxin B-positive (A+/B+). By pulsed-field gel electrophoresis analysis, 23 of the 30 A-/B+ strains were outbreak-related, suggesting nosocomial spread of a single type of bacterium, which mainly affected patients in the wards of respiratory medicine, hematology and neurology. Using regression analysis, three factors were found to be associated with infection by A-/B+ isolates: (i) exposure to antineoplastic agents ( P=0.01, odds ratio [OR]=5.1), (ii) the use of nasal feeding tubes ( P=0.008, OR=5.2), and (iii) assignment to a certain internal medicine ward ( P=0.05, OR=3.0). Between patients with Clostridium difficile-associated diarrhea caused by A-/B+ strains and those with A+/B+ strains, no statistically significant difference was found in body temperature, serum concentration of C-reactive protein, leukocyte count in whole blood, frequency of diarrhea, or type of underlying disease. These results indicate that A-/B+ strains of Clostridium difficile can cause intestinal infection in humans and they spread nosocomially in the same manner as A+/B+ strains.

Hospital outbreak of MEN-1-derived extended spectrum beta-lactamase-producing Klebsiella pneumoniae

An outbreak of Klebsiella pneumoniae resistant to broad spectrum cephalosporins occurred in a hospital in the Kinki area in Japan. During 18 months, from February 1998 to July 1999, 23 strains were isolated from 21 patients (10 with pneumonia, 4 with urinary tract infection, 1 with sepsis, 1 with vaginosis, 1 with a wound infection, and 1 with both pneumonia and sepsis; 3 patients showed noninfective colonization with K. pneumoniae) in seven wards, including the intensive care unit. MEN-1-derived gene was detected by polymerase chain reaction from the majority of the strains. Ninety-nine strains of K. pneumoniae were isolated during this period. The isolation rate of K. pneumoniae resistant to broad spectrum cephalosporins was 21%. We distinguished three clones by pulsed-field gel electrophoresis and randomly amplified polymorphic DNA analysis, and one of them was isolated from 18 patients. The presence of an R-plasmid of more than 160 kb was confirmed by plasmid analysis, but it was not possible to obtain transconjugants from all strains. This outbreak of K. pneumoniae was immediately confirmed by genetic analysis, and it was promptly ended by the infection control procedures. This is the first hospital outbreak of MEN-1-producing K. pneumoniae in Japan.

[Detection of extended spectrum beta-lactamases producing Enterobacteriaceae in feces]

A study was made of 366 feces for detection of extended spectrum beta-lactamases producing Enterobacteriaceae from feces. The selective agar was used for modified drigalski agar (Eiken Chemical Co., LTD) with 2 micrograms/ml cefotaxime (ESBL screen agar). 92 strains of Enterobacteriaceae, 41 Escherichia coli, 15 Citrobacter freundii, 13 Enterobacter cloacae, 11 Klebsiella pneumoniae, and other 12, were isolated from ESBL screen agar. And, R-plasmid that were selected by 2 micrograms/ml cefotaxime were transferred by conjugation from two of the 92 strains. These strain were E. coli TH9809927 and Proteus mirabilis TH9808262 that were amplified by "Toho-1 type" primer. The clude enzyme from two strains (donor) and transconjugants were especially hydrolysed cepharoridine and cefotaxime. Accordingly, two strains (0.5%) were detected as ESBL producers. We think that the result of our survey suggests the increase of ESBLs producing bacterial infection in Japan, and believe that there is a trend of infection of its by surveilance of the feces.

["What an ideal clinical microbiological laboratory should be"--from the position of patient]

To think about the ideal clinical microbiological laboratory in patient's place, there are three important problems in present medical treatment. The first one, for patients, it is necessary to wait many hours to take a medical advice from a doctor. The second, patients should be checked many examinations. The third, the heavy patient's share in his medical expenses. To settle a bit these matters, the clinical laboratory should try to accept the rapid and economical examinations for patients.

[Rapid detection of Shiga-like toxin gene in feces with rapid-cycle polymerase chain reaction]

A rapid detection for Shiga-like toxin in feces was developed with the nucleic acid extraction method by silicondioxide-guanidine thiothianate and rapid-cycle polymerase chain reaction by RapidCycler (model 1002; Idaho Technology, RC-PCR here after). Twenty-two fecal samples that were collected from patients with diarrhoea caused by E. coli O157:H7 and frozen for 6 months were examined directly by RC-PCR, conventional PCR assay using by ThermalCycler 9600-R (Roche, TC-PCR here after) and by the culture method using tellurite-cefixime sorbitol MacConkey (direct method). These examinations were done also after being injected into TCV-TSB and incutated at 35 degrees C overnight (indirect method). The sensitivity of RC-PCR and TC-PCR using a diluted suspension of broth enriched at 35 degrees C overnight were 4.1 pg and 410 fg, respectively. Positive results in the direct method were obtained in 7 for RC-PCR, 10 for TC-PCR and 5 for culture. Positive results on indirect assay were obtained in 9 for RC-PCR, 9 for TC-PCR and 7 for culture. It was demonstrated that the RC-PCR assay was able to detect Shiga-like toxin gene in feces in less than 90 minutes after being received at the laboratory.

[Rapid detection of Escherichia coli 0157:H7 in feces by latex agglutination and immunochromatographic assay]

The rapid detection method of Escherichia coli O157 in feces by using the latex agglutination test kit (Prolex; Pro Lab Diagnostics) and the immunochromatic assay kit (NOW EH. E. coli; Binax) was studied. 176 fecal samples obtained from 154 healthy men and 22 patients who had diarrhea by E. coli O157 were examined. Tellurite cefixim sorbitol MacConkey (TC-SMAC), Prolex and NOW were used for studies and also these were done after the enriched culture by tellurite cefixime vancomycin toriptic soy broth (TCV-TSB). In the direct inoculation, 5 (23%) of 22 samples, 7 (32%) and 9 (41%), and after the enriched culture, 7 (32%), 10 (46%) and 11 (50%) were positive by culture, Prolex and NOW, respectively. On the other hand, 154 samples from healthy men were all negative in the direct inoculation, but in the enriched culture, 7 of 40 (18%) were positive by NOW. These samples were negative by boiled (100 degrees C, 15 minutes). Our results indicated that Prolex and NOW were useful for accurate and rapid diagnosis of E. coli O157 enteritis, and more sensitivity results were obtained with the enrichment broth.

Management and design of the maintenance of SAM mouse strains: an animal model for accelerated senescence and age-associated disorders

The Senescence-Accelerated Mouse (SAM) was established by inbreeding and pedigree selection based on the life span, degree of senescence, as well as the incidence and degree of several age-associated disorders. At first, SAM strains were developed under conventional conditions, but now some strains are also maintained under specific pathogen-free conditions. There are many methods used to maintain such strains of mice; our methods will be introduced as one example of how to develop and maintain strains of mice used in aging research.

[Detection and identification method of three mycobacterium species and genus specific detection by polymerase chain reaction and DNA hybridization with alkaline phosphatase labeled oligonucleotide probe]

Rapid detection and identification method of mycobacteria from specimen with infected mycobacteriosis was established by the combination of polymerase chain reaction and alkaline phosphatase labeled oligonucleotide probe (PCR-ALPDH). We prepaired four kinds of probes: Mycobacterium tuberculosis complex, M. avium, M. intracellulare, and mycobacterial-probe other than tuberculosis. PCR-ALPDH was compared with conventional methods using 234 specimens which suspected mycobacteriosis. In culture, 68 specimens (29.1%) were positive and 166 specimens (70.9%) were negative. In PCR-ALPDH, 88 specimens (37.6%) were positive and 146 specimens (62.4%) were negative. In 68 specimens which were positive in culture, the agreement of results of conventional identification and PCR-ALPDH for each probes were: 39/40 (PCR-ALPDH/Culture, 97.5%) in M. tuberculosis 5/9 (55.6%) in M. avium, 6/6 (100%) in M. intracellulare and 22/28 (88.6%) in MOTT isolation. Among 166 negative culture specimens, 27 specimens were positive in PCR-ALPDH. The results indicated that PCR-ALPDH method was applicable for the establishment of rapid and sensitive mycobacterial diagnostic system.

[Isolation of enteropathogenic microorganism from patients with infection of the digestive tract during 1976 to 1988 in Tenri Hospital]

Enteropathogenic microorganisms isolated from feces of 9,393 patients with diarrhea or enteritis in our hospital between 1976 and 1988 were analyzed. As the result of the examination of 5,443 outpatients, 1,811 strains of pathogens were isolated from 1,686 cases (31.0%). Several species including Salmonella spp., Escherichia coli serotype, Vibrio parahaemolyticus, were isolated before 1978, and the incidence of pathogens was low (14.8%). For the 10-year period since 1979, the incidence markedly increased to 34.4%, and the number of pathogens isolated also increased to about twice that before 1978. The main cause of the increase was Campylobacter species. The major pathogens detected since 1979 were Campylobacter spp., E. coli serotype, Salmonella spp., V. parahaemolyticus, etc., but Rota virus, Clostridium difficile, Aeromonas spp., Vibrio fluvialis, etc. have also been detected, showing an increase in the number and diversity of the detected pathogens. As the result of the examination of 3,950 inpatients, 835 strains of pathogens were isolated from 800 cases (20.3%). The incidence of C. difficile was the highest, 423 of 800, followed by E. coli serotype, Salmonella spp., Campylobacter spp., V. parahaemolyticus and Aeromonas spp., in that order. All the inpatients from whom C. difficile was isolated manifested diarrhea or enteritis after administration of antimicrobial agents. The pathogens causing communicable disease were Salmonella spp. serovar Typhi, Salmonella spp. serovar Paratyphi A, Shigella flexneri, Shigella sonnei and Entamoeba histolytica, which were isolated from 5, 1, 3, 2 and inpatients, respectively.

[Prevention and control of nosocomial infection caused by methicillin resistant Staphylococcus aureus in premature infant ward--prevention effect of "povidone iodine solution" wipe of neonatal skin]

In January 1983, a number of premature infants under management in the premature infants' unit of our hospital were found to have bacteremia due to Staphylococcus aureus. By the end of February of the same year, 4 of these infants, who had been treated in the same unit, developed impetigo. The S. aureus responsible for this condition was classified as type IV by a coagulase typing. In a subsequent antimicrobial susceptibility test using the disk diffusion method, this microorganism was found to be resistant to methicillin, erythromycin and lincomycin, and to be susceptible to tetracycline, chloramphenicol and cefmetazole, indicating that it was a methicillin resistant S. aureus (MRSA). Because the result from the coagulase typing agreed with the antimicrobial susceptibility pattern in all cases, we concluded that these cases represented nosocomial infection with MRSA. The source and route of the infection were investigated, and measures taken to prevent bacterial spread from carriers and to keep instruments and environments clean. Although the source of infection was not identified. Then, we tried wiping the body surface of the premature infants with an Isodine solution (10% PVP-I, 1:100 dilution) in order to prevent colonization of the microorganism on the body surface. With this application+, MRSA was no longer detected from the body surface of the premature infants, and no additional MRSA infection occurred in the premature infants' unit. Data collected for premature infants' managed at our hospital in the subsequent 6 years allows us to conclude that MRSA infection can be almost completely controlled by frequent surveys of carriers and appropriate body surface wiping with Isodine solution.(ABSTRACT TRUNCATED AT 250 WORDS)

The antiobesity action of (S)-(+)-1-(4-chlorophenylthiomethyl)-N-methylethylamine fumarate (AO-124)

The antiobesity effects of (S)-(+)-1-(4-chlorophenylthiomethyl)-N-methylethylamine fumarate (AO-124) were examined in rats and dogs. AO-124 suppressed food intake dose dependently in normal, Zucker fatty and VMH-obese rats, and beagle dogs. Its anorectic activity was not altered by pretreatment with methysergide, a serotonin receptor blocker. AO-124 also reduced the hyperphagia induced by 2-deoxy-D-glucose but not that induced by insulin, noradrenaline or muscimol, suggesting that the anoretic mechanism of AO-124 may be implicated in a glucostatic regulatory system of feeding. In addition, AO-124 decreased insulin secretion in response to an oral, but not an intravenous, glucose load. Such a suppression in insulin secretion may be explained by slow absorption of glucose from the intestine: AO-124 delayed the gastric emptying time of glucose and inhibited the active transport of glucose as observed in the everted small intestine. Two week administration of AO-124 to Zucker fatty rats resulted in a significant reduction of plasma insulin levels, body weight gain, and body lipid without exerting any changes in body protein. These findings indicate that AO-124 may be useful as an antibesity agent on the basis of its unique mechanisms of action.

Relation of body energetic status to dietary self-selection in Sprague-Dawley rats

Self-selection from carbohydrate, protein and fat sources including essential micronutrients was studied in male Sprague-Dawley rats that were 4 weeks of age at the beginning of the experiment. During the experimental period of 14 days, the intake of carbohydrate and fat was quite constant, whereas that of protein increased gradually. The mean intake of carbohydrate, protein, and fat was 31.1 +/- 3.5%, 56.1 +/- 4.6%, and 12.8 +/- 2.8% of the total energy intake, respectively. Animals fed on a mixed diet consisting of high sucrose, consumed 65.1% of their daily energy as carbohydrate, 17.6% as protein, and 17.3% as fat. Total energy intake and body weight gain were not significantly different between the rats on self-selection and those fed on the mixed diet. These results indicate that young rats on dietary self-selection were able to gain body weight comparable to that of rats fed on the mixed diet. Body energetic status affected self-selection patterns. In rats fasted for 5 days or fed on a protein-free diet for 21 days, fat intake increased, but protein intake decreased. On the other hand, fat intake decreased in animals given a sucrose diet higher in energy content than the stock diet; these animals exhibited increased accumulation of body energy. These results indicate that dietary self-selection is closely related to nutritional and physiological body requirements.

Feeding in response to insulin and 2-deoxy-D-glucose in Zucker rats on dietary self-selection

Adult male fatty and lean rats of Zucker strain were given access ad libitum to either a single nutritionally complete diet, or a self-selection regime with separate sources of three macronutrients, protein (casein), fat (hydrogenated coconut oil), and carbohydrate (sucrose). Animals on the single diet were fed on a powdered stock diet, and then switched to the self-selection regime. Energy intake on the self-selection regime was the same as that for the single diet condition in both fatty and lean rats. Fatty rats consumed 45% more energy than did their lean littermates. Further, fatty rats selected 47.0% of their total calories as protein, 30.1% as fat, and 22.9% as carbohydrate. The respective percentages for lean rats were 56.1, 13.0 and 30.9. In lean rats, the injection of insulin (10 U/kg) or 2-deoxy-D-glucose (500 mg/kg, 2DG) failed to increase energy intake, but increased carbohydrate intake 2 times by attenuating protein intake. Also in fatty rats, insulin did not increase energy intake, but it did increase carbohydrate by 50% by attenuating fat intake. 2DG decreased energy intake by attenuating carbohydrate and fat intakes in fatty rats. Fatty rats were slightly less hypoglycemic to insulin, but more hyperglycemic to 2DG than lean rats. These different self-selection patterns of fatty rats seemed to be associated with their endocrine, metabolic, and behavioral abnormalities.

Recovery from impairment in feeding response to glucoprivic stimuli and in sensitivity to diabetogenic agents in riboflavin-repleted rats

Male weanling rats, fed a riboflavin-deficient diet for 14 days showed impairments in reactivity to the hyperphagic action of either insulin or 2-deoxy-D-glucose (2DG) and in sensitivity to the diabetogenic action of streptozotocin or alloxan. The intraperitoneal injection of riboflavin (160 micrograms/rat) resulted in an immediate restoration in FAD-dependent activation of erythrocyte glutathione reductase and in the reactivity of food intake to insulin, whereas the reactivity of food intake to 2DG was restored after 3 days of riboflavin repletion. The sensitivity to diabetogenic agents was not restored solely by the riboflavin injection but required 3 hours of feeding as well. These findings indicate that the riboflavin deficiency caused some defects at specific glucosensitive sites localized in the pancreas and the brain and that some metabolic processes were necessary to restore the sensitivity.

Reduced sodium excretory ability in young spontaneously hypertensive rats

The excretory response of spontaneously hypertensive rats (SHR) and stroke-prone SHR (SHRSP) to acute saline load was compared to that of control Wistar Kyoto rats (WKY) in pre- and early-hypertensive phases. In each of the 3 groups, half of the animals was fed a low salt diet, and the other half a normal diet. At the prehypertensive phase, sodium and water excretion and sodium-potassium ratio in the urine in SHR and SHRSP fed a normal diet were significantly less than those in WKY. The ability of SHR to excrete sodium and water, however, was improved by the elevation of blood pressure that developed between 7 and 10 weeks after their birth. While young SHR fed a normal diet had a reduced ability to excrete sodium, the young SHR fed a sodium-restricted diet did not. Salt restriction significantly delayed the appearance of high blood pressure in both SHR and SHRSP. These results suggest that in both SHR and SHRSP, and elevation of blood pressure is important to compensate for the reduced ability to excrete sodium and water.

Studies on analgesic agents. 1.1a Preparation of 1,2-diphenyl-2-(4-substituted 1-piperazinyl)ethanol derivatives and structure-activity relationships

The preparation and analgesic activity of a series of the title compounds (8-55 and 57) are described. The intermediates, 2-phenyl-2-(1-piperazinyl)acetophenones 5 and 6, were prepared from benzyl phenyl ketones 3 via their bromides 4. On reduction, compounds 5 afforded the titled compounds 8-12, 16, and 26-48. Compounds 13-15 and 17-25 were obtained by alkylation or benzylation of 1.2-diphenyl-2-(1-piperazinyl)ethanols 7 derived from 6 by reduction. The reduction of 5 and 6 with metal hydrides predominantly gave the erythro isomers. The erythro isomers were remarkably more active than their threo isomers. The more active members in this series of compounds were 16 and derivatives 35 and 37-44 of dl-erythro-1-phenyl-2-(substituted phenyl)-2-[4-(p-methoxybenzyl)-1-piperazinyl]ethanol. Compounds 16, 43, and 44 were the most active with a potency of about two to three times that of codeine. Racemates 16 and 38 were resolved into their optical isomers and it was found that (-)-16 and (+)-38 were more potent than their antipodes. Structure-activity relationship are discussed.

Effects of nutritional factors on the development of ethanol-induced fatty liver in KK and KK-Ay mice

KK and KK-Ay mice developed a steady and reproducible fatty liver when they were given free access to an ethanol solution as a drinking fluid for 10 to 20 days. The present studies were undertaken to elucidate effects of nutritional factors on liver fat contents of the mice given water or ethanol solution. In contrast to cornstarch, sucrose tended to increase the liver fat of control mice. A higher concentration of dietary casein lowered the liver fat of control mice, whereas the dietary concentration of cottonseed oil did not significantly affect the liver rat levels either in control or ethanol groups. Thus the standard basal diets favorable for the development of the alcoholic fatty liver have been established, for example, 10% cottonseed oil, 25 and 30% casein, 58.4 and 53.4% cornstarch for KK (12-15 weeds old) and KK-Ay (5-10 weeks old), respectively. Neither choline, myoinositol, nor any lipotropic agent tested prevented the development of the alcoholic fatty liver. Unlike in rats, orotic acid did not induce a fatty liver but rather alleviated the ethanol-induced fatty liver in these mice.