Congenital semilunar valvulogenesis defect in mice deficient in phospholipase C epsilon

Phospholipase Cepsilon is a novel class of phosphoinositide-specific phospholipase C, identified as a downstream effector of Ras and Rap small GTPases. We report here the first genetic analysis of its physiological function with mice whose phospholipase Cepsilon is catalytically inactivated by gene targeting. The hearts of mice homozygous for the targeted allele develop congenital malformations of both the aortic and pulmonary valves, which cause a moderate to severe degree of regurgitation with mild stenosis and result in ventricular dilation. The malformation involves marked thickening of the valve leaflets, which seems to be caused by a defect in valve remodeling at the late stages of semilunar valvulogenesis. This phenotype has a remarkable resemblance to that of mice carrying an attenuated epidermal growth factor receptor or deficient in heparin-binding epidermal growth factor-like growth factor. Smad1/5/8, which is implicated in proliferation of the valve cells downstream of bone morphogenetic protein, shows aberrant activation at the margin of the developing semilunar valve tissues in embryos deficient in phospholipase Cepsilon. These results suggest a crucial role of phospholipase Cepsilon downstream of the epidermal growth factor receptor in controlling semilunar valvulogenesis through inhibition of bone morphogenetic protein signaling.     

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.     

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.     

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.     

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.     

Inhibition of tumor cell growth by a human B-cell line

An Adenocarcinoma cell line (Breast-M) and an Epstein-Barr virus (EBV)-infected B-cell line (Hairy-BM) were established from breast tumor tissue. The Hairy-BM was CD20⁺, CD25 (Tac)+ and surface immunoglobulin (sIg)+. Hairy-BM suppressed the in vitro proliferation of Breast-M in a time and a dose-dependent manner. The suppression was also found in 5 different human tumor targets showing tumor-Hairy-BM binding, but not; in 2 murine tumor targets showing no significant tumor-Hairy-BM binding. Lytic activity of Hairy-BM was found only against Breast-M.Abbreviations sIg Surface immunoglobulin - CTL Cytotoxic T-cells - NK Natural killer - IL2 Interleukin 2 - LAK Lymphokine activated killer - CSN Culture supernatant - MTT 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazoolium bromide - PCR Polymerase chain reaction - TIL Tumor-infiltrating lymphocytes - HCL Hairy cell leukemia - TNF Tumor necrosis factor     

A retrospective serological study of Japanese who contracted dengue fever in Thailand

Between September and November 1981, some members of a survey team from Japan suffered from a febrile illness diagnosed clinically as dengue fever during their stay in a village in Khon-Kaen Province, in the north-eastern part of Thailand. The morbidity rate in the team was as high as 69% (11/16). Blood samples were taken from 12 of the 16 members of the team in February, 1982 in Japan and the serum specimens were examined for antibodies to dengue (DEN), Japanese encephalitis (JE) and yellow fever (YF) viruses respectively. The results of the tests indicated that all 8 members who had had symptoms had been infected with DEN type 1 virus. No case of inapparent infection with dengue viruses was found. Of these 8 persons, seven had had neutralizing (N) antibody to JE virus before infection, but their clinical manifestations had been similar to those of an individual without N antibody to JE virus and were typical symptoms of dengue fever, such as leukopenia and "saddle-back" fever, without hemorrhagic manifestations, as seen from platelet counts and hematocrit values.     

The histochemistry of complex carbohydrates in the ovarian follicles of adult mice

Summary In the ovarian follicles of adult mice, complex carbohydrate-containing structures have been studied by means of light microscopic histochemical methods. In the ovarian follicles, the zona pellucida of oocytes, follicular fluid and intercellular matrix of the granulosa layer are found to exhibit positive reactions for complex carbohydrates with 1,2-glycol and acidic groups and -D-mannosyl and -D-glucosyl residues. The present histochemical analyses have revealed that the complex carbohydrates common to the three types of the structures are hyaluronic acid, sulfated glycosaminoglycans other than isomeric chondroitin sulfates and neutral glycoproteins and that sialic acid is a particular moiety of the zona pellucida, whereas isomeric chondroitin sulfates being that of the follicular fluid and intercellular matrix of the granulosa layer. The histophysiological activities of the carbohydrate-containing structures have been discussed with special reference to their histochemical properties determined in the present study.     

Apoptosis induced by the histone deacetylase inhibitor FR901228 in human T-cell leukemia virus type 1-infected T-cell lines and primary adult T-cell leukemia cells

Inhibition of histone deacetylase (HDAC) activity induces growth arrest, differentiation, and, in certain cell types, apoptosis. FR901228, FK228, or depsipeptide, is an HDAC inhibitor effective in T-cell lymphomas. Adult T-cell leukemia (ATL) is caused by human T-cell leukemia virus type 1 (HTLV-1) and remains incurable. We examined whether FR901228 is effective for treatment of ATL by assessing its ability to induce apoptosis of HTLV-1-infected T-cell lines and primary leukemic cells from ATL patients. FR901228 induced apoptosis of Tax-expressing and -unexpressing HTLV-1-infected T-cell lines and selective apoptosis of primary ATL cells, especially those of patients with acute ATL. FR901228 also efficiently reduced the DNA binding of NF-kappaB and AP-1 in HTLV-1-infected T-cell lines and primary ATL cells and down-regulated the expression of Bcl-x(L) and cyclin D2, regulated by NF-kappaB. Although the viral protein Tax is an activator of NF-kappaB and AP-1, FR901228-induced apoptosis was not associated with reduced expression of Tax. In vivo use of FR901228 partly inhibited the growth of tumors of HTLV-1-infected T cells transplanted subcutaneously in SCID mice. Our results indicated that FR901228 could induce apoptosis of these cells and suppress the expression of NF-kappaB and AP-1 and suggest that FR901228 could be therapeutically effective in ATL.