Encephalomyocarditis (EMC) virus-induced sialodacryoadenitis in mice

The mode of occurrence of the D variant of encephalomyocarditis (EMC-D) virus-induced acute sialodacryoadenitis was investigated using three strains of mice differing in their sensitivity to EMC-D virus-induced diabetes (C57BL/6: resistant; BALB/c: moderately sensitive; DBA/2: highly sensitive). Mice were intranasally inoculated with high (10(5) PFU/mouse) or low dose (10(2) PFU/mouse) of EMC-D virus. Although there were individual differences, the blood virus titer generally reached the peak earlier in the high-dose group than in the low-dose group. Signals of viral RNA and histopathological changes were seen in parotid glands and intraorbital and extraorbital lachrymal glands. In these glands, signals of viral RNA and histopathological changes were detected only in acinar cells and initial lesions were characterized by pyknosis of acinar cells. Coagulative necrosis with interstitial inflammatory cell infiltration developed later in parotid glands of BALB/c mice of the high-dose group and in intraorbital and extraorbital lachrymal glands of all groups except for C57BL/6 mice of the low-dose group. Such changes were not observed in epithelial cells of the ductal system. The present results indicate that EMC-D virus shows clear tissue and cell tropism within the salivary and lachrymal glands, probably due to the distribution of receptors for EMC virus.     

Noninvasive method for measuring the electrical properties of deep tissues using an open-ended coaxial probe

A new noninvasive method of measuring the structure and the electrical properties of bilayered biological tissues was evaluated as a potentially useful diagnostic means for detecting changes in subcutaneous tissues. First, the input impedance of an open-ended coaxial probe radiating into a bilayered model was calculated using a full-wave method, the results showed that the evanescen higher order modes do not have a significant influence on the reflection coefficient of muscle layer surface. Then, it was clearly proven that the phase shift and the modulus of the reflection coefficient of muscle layer surface depending on the frequency are useful to estimate the thickness of fat layer and the electrical properties of muscle respectively. The experimental results showed an excellent agreement with the theoretical relationship between the phase shift and the thickness. The sensitivity of estimation of the electrical properties of muscle was shown to be not enough for differentiating between normal and diseased deep tissue because of noises from the experimental systems.     

Two Autopsy Cases of Primary Leiomyosarcoma of the Liver Superiority of Muscle-specific Actin Immunoreactivity in Diagnosis

Two autopsy cases of leiomyosarcoma of the liver in a 49-year old female and 63-year-old male are reported. Both of the liver tumors showed electron microscopically dense patches in the cytoplasm and intermediate junctions between the tumor cells, suggesting a smooth muscle cell origin, irrespective of their different histological features. The nature of both tumors was confirmed by positive immunoreactivity for muscle-specific actin in the tumor cells, whereas desmin immunoreactivity was labile in both cases, showing a higher diagnostic value of the former compared with the latter in these leiomyosarcomas. Both cases, showed extensive distant metastases in spite of an evident difference in their mitotic indices, indicating that this index is not reliable for judging the metastatic potential of these tumors. Acta Pathol Jpn 41: 461–465, 1991.     

Development of T cells in SCID mice grafted with fetal thymus from AKR mice or F344 rats

To examine the development of T cells within an allogeneic or xenogeneic environment, we engrafted the fetal thymus from AKR mice or F344 rats under the kidney capsule of SCID mice (mTG and rTG mice). T lymphopoiesis developed in SCID mice 2 months after transplantation, although the ratio of CD4/CD8 in both experimental groups was different from that of normal control. T cells in mTG mice did not show in vitro proliferation or cytotoxicity against either host-type C.B-17 (H-2^d) or donor-type AKR (H-2^k) cells, while they exerted potent activities against third-party BIO (H-2^b) cells. In contrast, T cells in rTG mice exhibited proliferation against both host-type C.B-17 and donor-type F344 rat cells. Consistently, graft-vs.-host disease symptoms developed in these mice and histological examination showed impressive infiltration of lymphocytes into the skin or into the mucosal layers of the stomach. Activated state of T cells in rTG mice was also evidenced by the positive expression of interleukin-2 receptor. Taken together, fetal thymus appears to contain progenitor cells which are sufficient for in vivo reconstitution of T lymphopoiesis, but species-specific environment is important for the induction of tolerance. In mTG mice, Vβ6⁺ T cells reactive to donor Mls^a determinants and Vβ3⁺ T cells reactive to host Mls^c determinants were deleted, suggesting that tolerance was regulated mainly by clonal deletion. By contrast, Vβ11⁺ T cells reactive to Mls^f determinants were not deleted possibly due to the lack of their ligands.     

Wnt signaling plays an essential role in neuronal specification of the dorsal spinal cord

In the developing spinal cord, signals from the roof plate are required for the development of three classes of dorsal interneuron: D1, D2, and D3, listed from dorsal to ventral. Here, we demonstrate that absence of Wnt1 and Wnt3a, normally expressed in the roof plate, leads to diminished development of D1 and D2 neurons and a compensatory increase in D3 neuron populations. This occurs without significantly altered expression of BMP and related genes in the roof plate. Moreover, Wnt3a protein induces expression of D1 and D2 markers in the isolated medial region of the chick neural plate, and Noggin does not interfere with this induction. Thus, Wnt signaling plays a critical role in the specification of cell types for dorsal interneurons.     

Proliferation of exogenously injected primordial germcells （PGCs） into busulfan-treated chicken embryos

Aim: This study was designed to investigate the effect of busulfan treatment on the proliferation of chicken primordialgerm cells (Fgcs) in vivo, focusing on the preferential settlement of PGCs onto the germinal ridges of chicken em-bryos. Methods: Bustdfan (250 rig/egg) was injected into the egg white of freshly oviposited fertilized eggs, whichwere then incubated. Embryonic developnent and viability were examined, and exogenous PGCs collected from embry-onic blood vessels were injected into the germinal crescent region of recipient enthryos. The nttmber of PGCs residedonto germinal ridges of the right and left sides were compared. Results: Bustdfan had a slight harmful effect on theembryo viabihty and the PGCs proliferation. The number of PGCs resided onto the left side of germinal ridges wasslightly higher as compared with the right side. Conclusion: Busulfan suppressed the viability of embryos and the pro-liferation of endogenous PGCs in the recipient embryos. However, the number of exogenous PGCs proliferated washigher in embryos treated with busnlfan than those without busulfan. Data also suggest the possibihty of a preferentialresidence of PCCs toward the left side of the germinal crescent region as compared with the right, which may be due toa more advanced functional development of the left gonad than the right. (Asian JAndro11999 Dec; 1 : 187 - 190)     

Reproductive characteristics of transgenic (TG) chickens carrying an exogenous gene

An exogenous gene (lacZ/MiwZ) introduced into the germinal crescent region (GCR) of avian embryos was confirmed to be successfully transferred to the gonads via the primordial germ cells (PGCs). Following hatching, the chicks were raised until the stage of sexual maturation. The incorporation of MiwZ DNA was detected in male and female transgenic chickens, respectively. The normal male and female transgenic birds were subjected to artificial insemination according to routine methods. Fertilized eggs obtained from female transgenic chickens were incubated for 72 h and the embryos removed from the yolk were examined by X-gal staining to detect the introduction of MiwZ in the offspring. As a result, the expression of MiwZ was detected in the offspring. Furthermore, the presence of MiwZ in the extracts from embryos was also detected by polymerase chain reaction (PCR) analysis. In male transgenic chickens, the presence of injected MiwZ in the extracts from sperm was also confirmed. The exogenous gene introduced into the GCR migrated successfully to the gonad resulting in its incorporation into the offspring and spermatozoa of transgenic chickens.     

Subjects with <Emphasis Type="Italic">TNF-A-857TT</Emphasis> and <Emphasis Type="Italic">-1031TT</Emphasis> genotypes showed the highest <Emphasis Type="Italic">Helicobacter pylori</Emphasis> seropositive rate compared with those with other genotypes

Background A possible association between Helicobacter pylori seropositivity and tumor necrosis factor (TNF) A G-308A has been reported in Korea. The present study examined the associations of H. pylori with functional polymorphisms, TNF-A G-308A, C-857T, and T-1031C, and TNF-B A252G in Japanese subjects.Methods The total of 1374 study subjects included 241 outpatients who participated in an H. pylori eradication program (HPE), 679 first-visit outpatients (FVO) at a regional cancer hospital, and 454 local residents who received a health checkup examination (HCE).Results The frequency of the TNF-A -308A allele was only 1.3% of 480 chromosomes in the HPE group, so the FVO and HCE groups were not genotyped for that polymorphism. The genotype frequency of TNF-A C-857T was 69.2% CC, 27.7% CT, and 3.1% TT; that of TNF-A T-1031C was 69.4% TT, 28.1% TC, and 2.5% CC; and that of TNF-B A252G was 36.8% AA, 48.2% AG, and 15.0% GG. TNF-A -857T was tightly linked to TNF-A -1031T and TNF-B 252A. No significant associations between H. pylori seropositivity and polymorphisms of TNF-A C-857T and TNF-B A252G were observed. However, a reduced odds ratio adjusted for sex, age, and recruitment source was observed for TNF-A -1031CC (0.43; 95% confidence interval, 0.20–0.91) relative to TNF-A -1031TT. Subjects with TNF-A -857CC and -1031CC showed the lowest seropositivity (38.2% of 34 participants), while those with TNF-A -857TT and -1031TT showed the highest (66.7% of 42 participants).Conclusions This study suggests that the possibly high expression genotype of TNF-A may increase susceptibility to persistent H. pylori infection.     

Optic-spinal form of multiple sclerosis and immune-mediated myelopathy in Japan

Optic-spinal form of multiple sclerosis (OS-MS) and HTLV-I associated myelopathy/tropical spastic paraparesis (HAM/TSP) are two immune-mediated myelopathy relatively common in Japan. (1) Transverse myelitis, once seen in 60% of MS, mostly OS-MS, 30 years ago, drastically decreased (5%) recently in Japan. In contrast, frequency of conventional form of MS (C-MS) increased during this period of time. But unlike C-MS in white patients, cerebellar hemispheric lesions are uncommon in Japanese C-MS. These findings emphasize influence of changes in exogenous factors on manifestations of MS and distinct genetic factors related to MS in Japanese and white patients. (2) To clarify the reason of high HTLV-I proviral load in HAM/TSP, we studied cellular immune surveillance against HTLV-I and found that significant cytotoxic T lymphocyte activity, and suppressed natural killer activity and antibody-dependent cell-mediated cytotoxicity in the patients. These altered immune surveillance may be associated with the spread of HTLV-I infection and the pathogenesis of HAM/TSP.     

Effect of N-methyl-2-pyrrolidone on skin permeation of estradiol.

N-Methyl-2-pyrrolidone (NMP) increased the skin permeation of estradiol (E2) in Yucatan micropig epidermis using a modified Franz-type diffusion cell. The addition of NMP significantly increased the fluxes of E2 from water and soybean oil. The flux and skin concentration of E2 were higher from soybean oil than from water and increased with increasing NMP concentrations in soybean oil. Correlation was observed with E2 flux and skin concentration (R(2) = 0.804) NMP enhanced E2 skin permeation because NMP made E2 skin concentration higher. Thus, NMP (10%) was added to the oily gel made by isocetyl isostearate and hydrogenated phospholipid. E2 permeation from the gel without NMP was the same as that from soybean oil suspension. The flux of E2 from the gel with NMP was 0.6 microg/h per cm(2) and might be sufficient for estrogen replacement therapy.