Characteristics of depressive behavior induced by feeding thiamine-deficient diet in mice

We produced thiamine-deficient (TD) mice by TD diet treatment. The growth curve of mice on TD feeding was sharply increased until on the 10th day and subsequently the body weight gradually decreased. The mortality rate in mice was about 67% on the 30th day after the start of TD feeding. We performed the forced swimming test on the 10th and 20th day after the start of TD feeding. The duration of immobility in the forced swimming test was increased on the 20th day of TD feeding. Locomotor activity and motor co-ordination between the pair-fed control group and TD group on the 20th day of TD feeding were not significantly changed. Only a single injection of thiamine HCI (50 mg/kg, s.c.) on the 10th day after the start of a TD diet shortened the increased duration of immobility in the forced swimming test on the 20th day after the start of TD feeding. Whereas these reversal effects of thiamine treatment on the 20th day were not found when the treatment was given on the 19th day after the start of a TD diet. On the 20th day after the start of TD feeding, the increased duration of immobility time induced by TD was shortened by chronic administration of the tricyclic antidepressant imipramine (10 mg/kg, i.p.). These results suggested that behavioral changes in the forced swimming test might be involved in the degeneration of serotonergic and noradrenergic neurons.     

Molecular characteristics of tissue-bound semicarbazide-sensitive amine oxidase (SSAO) in guinea pig tissues

Various mammalian tissues contain a tissue-bound amine oxidizing enzyme distinct from mitochondrial outer membrane enzyme, monoamine oxidase (MAO, EC 1.4.3.4), termed semicarbazide-sensitive amine oxidase (SSAO, EC 1.4.3.6). An increase in SSAO activity was found in patients suffering from vascular disorders such as diabetes and diabetic complications. It has previously been shown that 2-bromoethylamine (2-BEA) is a potent, and selective suicidal inhibitor of tissue-bound SSAO. The aim of this study was to investigate the interaction of this suicidal SSAO inhibitor with the tissue-bound enzyme in guinea pig lung, kidney, stomach, and heart homogenates. The conditions necessary for this inhibitor to titrate the concentrations of this enzyme were also determined. 2-BEA appears to interact with SSAO, as reported previously for this enzyme from different sources, in a manner consistent with an irreversible, "suicide" reaction. Because of this property, 2-BEA could be used to titrate the concentrations of SSAO active centers in these tissues under the appropriate conditions employed. Although some possible non-specific binding of the inhibitor to sites other than the active center of the enzyme, metabolism of this inhibitor and/or presence of enzyme subtypes was hypothesized, the molecular characteristics of SSAO in these tissues (Km, Vmax values, enzyme efficiencies, approximate enzyme concentrations, and molecular turnover numbers) towards the substrate kynuramine (0.1 mM) at pH 7.4 and 37 degrees C have been estimated.     

Possible Mechanism of Action of β-Lactam-Enhancing Factor on Methicillin-Resistant Staphylococcus aureus

We have recently found a factor (Factor T) in aged mixtures of tungstate and phosphate which greatly enhances the antibacterial effects of β-lactams on methicillin-resistant strains of staphylococcal species such as methicillin-resistant Staphylococcus aureus (MRSA), but shows only weak effects on methicillin-susceptible S. aureus and bacterial strains other than staphylococci. Factor T alone did not strongly inhibit cell metabolism and bacterial growth unless an excess amount was added. When Factor T was added to the culture medium beforehand, the growth of MRSA cells was rapidly suppressed just after addition of oxacillin (MPIPC). However, the growth of the cells was inhibited gradually when these two reagents were added in reverse order. For full expression of the enhancing effect, it seemed necessary for cells of MRSA strains to be incubated with Factor T for at least 2–3 hr. When the cells were washed after being sensitized by incubating them for 5 hr with Factor T, it took approximately 1 hr for the cells to recover their resistance to MPIPC. Factor T reduced the amount of penicillin-binding protein-2′ (PBP 2′), and thus sensitized the MRSA strains to β-lactams.     

Subchronic stress-induced depressive behavior in ovariectomized mice

AimsMood disorders including depression are more common in women than men, particularly in times of lower estradiol levels. In this study, we investigated the effect of estrogen on emotional behavior in mice in a stress environment.Main methodsFemale mice were divided into four groups: two groups were ovariectomized (OVX) and two were sham-operated. One group each of OVX and sham mice was kept in a normal environment and the other groups were assigned to a daily stress (1 h/day) for 7 days from 5 days after operation. On the 14th day after operation, subjects were measured to assess behavioral specificity, locomotor activity, elevated plus-maze (EPM) behavior, passive avoidance (PA) behavior and forced swimming behavior.Key findingsThe OVX plus stress (OVX + S) group showed a significant prolongation of immobility compared with the other groups. In all the groups there were no changes in locomotor activity, EPM behavior or PA behavior. We further examined the effect of estrogen against depressive behavior in the OVX + S group. The vehicle or 17β-estradiol (E2) was administered s.c. to OVX + S mice for 4 days beginning on post-operative day 11. Subchronic E2 treatment decreased the stress response and improved depressive behavior relative to the vehicle group.SignificanceThese data have important implications regarding the prevention of depression in postmenopausal women undergoing estrogen therapy.     

The Effect of CO2 Enrichment on the Growth of Nodulated and Non-Nodulated Isogenic Types of Soybean Raised Under Two Nitrogen Concentrations

To find the effects of CO₂ enrichment on plant development and photosynthetic capacity of nodulated (line A62-1) and non-nodulated (line A62-2) isogenic lines of soybean (Glycine max Merr.), we examined the interactions among two CO₂ treatments (36±3 Pa = AC and 70±5 Pa = EC), and two nitrogen concentrations [0 g(N) m⁻²(land area) = 0N; 30 g(N) m⁻²(land area) = 30N]. Nodules were found in both CO₂ treatments in 0N of A62-1 where the number and dry mass of nodules increased from AC to EC. While the allocation of dry mass to root and shoot and the amount of N in each organ did not differ between the growth CO₂ concentrations, there was larger N allocation to roots in 0N than in 30N for A62-2. The CO₂-dependence of net photosynthetic rate (P _N) for A62-1 was unaffected by both CO₂ and N treatments. In contrast, the CO₂-dependence of P _N was lower in 0N than in 30N for A62-2, but it was independent of CO₂ treatment. P _N per unit N content was unaffected by CO₂ concentrations. The leaf area of both soybean lines grown in 30N increased in EC. But in 0N, only the nodulated A62-1 showed an increase in leaf area in EC. Nitrogen use efficiency of plants, NUE [(total dry mass of the plant)/(amount of N accumulated in the plant)] in 30N was unaffected by CO₂ treatments. In 0N, NUE in EC was lower than in AC in A62-1, and was higher than that at AC in A62-2. Hence, the larger amount and/or rate of N fixation with the increase of the sink-size of symbiotic microorganisms supplied adequate N to the plant under EC. In EC, N deficiency caused the down-regulation of the soybean plant. This revised version was published online in June 2006 with corrections to the Cover Date.     

Epidemiological and Ecological Studies of Japanese Encephalitis in Okinawa,Subtropical Area in Japan. I. Investigations on Antibody Levels to Japanese Encephalitis Virus in Swine Sera and Vector Mosquito in Okinawa,Miyako and Ishigaki Islands

From 1985 to 1989, serum specimens of swine raised in the northern, central and southern areas in Okinawa island were examined for Japanese encephalitis (JE) virus antibody by ELISA and hemagglutination-inhibition test. The antibody positive rate was found to be higher in the north and central than in the south. The 2-mercaptoethanol sensitive antibody to JE was detected mostly in June and July, and occasionally in other months except February and March. There was no month when all specimens from three areas turned antibody-negative simultaneously, indicating that JE virus transmission to swine lasted longer in Okinawa island than in other temperate areas in Japan. From 1986 to 1991, the vector mosquitoes (Culex tritaeniorhynchus) were collected in a pig farm in the south of Okinawa island. A total of 153 strains of JE virus was isolated from the vector mosquitoes mainly in June. In Miyako and Ishigaki islands, the antibody positive rate in swine sera was found to be extremely low, compared with that in Okinawa island. In Miyako island, where no paddy rice field is cultivated, a few adults as well as larvae of the vector mosquito were collected, while in Ishigaki island, where there are many watered rice fields, a lot of adults as well as larvae were collected. Although the environmental situation is quite different between the two islands, JE virus transmission appeared to be very low in both islands.     

A method on strain measurement of HAP in cortical bone from diffusive profile of X-ray diffraction

Bone tissue is a composite material composed of hydroxyapatite (HAp) and collagen matrix. As HAp is a crystalline structure, an X-ray diffraction method is available to measure the lattice strain of HAp crystals. However, mineral particles of HAp in bone have much lower crystallinity than usual crystalline materials, which show a diffusive intensity profile of X-ray diffraction. It is not easy to determine quantitatively an infinitesimal strain of HAp from the peak position of diffusive profile. In order to improve the accuracy of strain measurement of HAp in bone tissue and to obtain reproducible results, this paper proposes an X-ray diffraction method applied to a diffusive profile for low crystallinity. This method is to estimate the lattice strain of HAp using not a peak position but a whole diffraction profile. In this experiment, a strip specimen of 28 x 8 x 2 mm was made from bone axial, outside circumferential and cross-sectional circumferential region in the cortical bone of bovine femur. The X-ray diffraction measurements were carried out before and after applying an external load. As a result, the precision of strain measurement was much improved by this method. Although a constant value of macroscopic strain was applied in the specimen, the lattice strain had a lower value than the macroscopic strain and had a different value in each specimen.     

Construction of human Fab (gamma1/kappa) library and identification of human monoclonal Fab possessing neutralizing potency against Japanese encephalitis virus

A combinatorial human Fab library was constructed using RNAs from peripheral blood lymphocytes obtained from Japanese encephalitis virus hyper-immune volunteers on pComb3H phagemid vector. The size of the constructed Fab library was 3.3x10(8) Escherichia coli transformants. The library was panned 3 times on the purified Japanese encephalitis virus (JEV) virion, and phage clones displaying JEV antigen-specific Fab were enriched. The enriched phage pool was then screened for clones producing Fab molecule with JEV neutralizing activity by the focus reduction-neutralizing test. Among 188 randomly selected clones, 9 Fab preparations revealed neutralizing activities against JEV strain Nakayama. An E. coli transformed with TJE12B02 clone, which produced human monoclonal Fab with the highest neutralizing activity was cultured in a large scale, and the Fab molecule was purified using affinity chromatography. The purified FabTJE12B02 showed the 50% focus reduction endpoint at the concentration of 50.2 microg/ml (ca. 1,000 nM) when JEV strain Nakayama was used. The FabTJE12B02 recognized E protein of JEV strain Nakayama, and the dissociation equilibrium constant (Kd) of the FabTJE12B02 against purified JEV antigen was calculated as 1.21x10(-8) M. Sequence analysis demonstrated that TJE12B02 used a VH sequence homologous to the VH3 family showing 88.8% homology to germline VH3-23, and used a Vkappa sequence homologous to the VkappaII subgroup showing 92.8% homology to germline A17.     

Epidemiological profile of patients hospitalized with candiduria in the Central-Western region of Brazil

BackgroundCandida yeasts are considered the main agents of nosocomial fungal infections.AimsThis study aimed to establish the epidemiological profile of patients with candiduria hospitalized in the capital of the State of Mato Grosso, in the Central-Western region of Brazil.MethodsPatients from three private hospitals and a public hospital participated in the study. This was an observational and cross-sectional study including analysis of patients mortality. It was carried out from March to August 2015.ResultsA total of 93 patients with candiduria were evaluated. Candida tropicalis was found most commonly (37.6%; n = 35), followed by Candida albicans (36.6%; n = 34), Candida glabrata (19.3%; n = 18), psilosis complex (4.3%; n = 4), Candida lusitaniae (1.1%; n = 1) and Candida krusei (1.1%; n = 1). Antibiotic therapy (100%) and the use of an indwelling urinary catheter (89.2%; n = 83) were the most frequent predisposing factors. Antifungal treatment was given to 65.6% of the patients, and anidulafungin was the most used antifungal. Mortality rates were 48% higher among patients with candiduria who had renal failure. Micafungin was the antifungal most prescribed among the patients who died. Candidemia concomitant with candiduria occurred in eight (8.6%; n = 8) cases. Considering the species recovered in the blood and urine, only one patient had genetically distinct clinical isolates.ConclusionsNon-C. albicans Candida species were predominant, with C. tropicalis being the most responsible for most cases of candiduria.     

Locoregional immunotherapy of head and neck cancers utilizing allogeneic spleen cells — a report of 2 cases

Frozen-stored human spleen cells (SC) cultured with streptococcus preparation OK-432 acquired direct cytotoxicity to autologous as well as allogeneic tumor cells. The activated cells started to produce cytocidal cytokine TGIF, which is distinct from previously known cytokines.We examined the possibility of allogeneic adoptive immunotherapy (AIT) using these OK-432-stimulated spleen cells (OK-SC) in two cancer patients. Rapid necrosis of cancer tissue and remarkable decreases of tumor markers in tumor effusion were observed. There were no severe side effects.