To elucidate the possible regulation of endome­trial growth, we investigated the expression of tenascin, an extracellular matrix protein associated with cell proliferation and morphogenetic events, in relation to the mitotic marker ki-67 antigen in human endometrium throughout the menstrual cycle. The endometrial tissue was obtained from women with regular menstruation undergoing hysterectomy due to benign uterine disease. Cryostat sections were subjected to double immunohistochemistry to detect both tenascin and ki-67. During the proliferative phase, an intense deposition of tenascin fibrils occurred in the extracellular matrix of the stroma immediately subjacent to the uterine epithelium that showed the highest proportion of ki-67 positive cells. In the secretory phase, the amount of tenascin expres­sion and the proliferative index of the epithelium were markedly reduced. The topological immunoreactivity of tenascin, however, was clearly related to ki-67 localization close to the tortuous endometrial gland and spiral artery. Expression of tenascin, showing changes depending on the menstrual phase, appears to be influenced by ovarian steroid hormones, and it might play a role in regulating human endometrial development by interaction with mitotic cells.

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Castability of Ti-6Al-7Nb alloy,CP Ti, and Co-Cr alloy was examined for mesh type and plate type specimens. The casting was carried out with a pressure type casting machine and commercial molding material. The castability of the mesh type specimen was evaluated in terms of the number of cast segments (castability index), and that of the plate type was evaluated by the area of the speci­men (casting rate). X-ray images processed by a digital imaging technique were used to identify the casting porosity.The casting rate of the specimens increased with increasing thickness of the specimens. It was concluded that the castability index and the casting rate of Ti-6Al-7Nb alloy was slightly lower than that of CP Ti, and higher than that of Co-Cr alloy, were as Ti-6Al-7Nb alloy showed fewer casting porosities than CP Ti and smaller ones than Co-Cr alloy, which was advantageous for increasing the reliability of the casting properties.

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Obturator prostheses have been extensively used in the functional rehabilitation of maxillectomy patients. The purpose of this study was to evaluate in vitro the vibration movements of three types of obturator prostheses. Three types of bulbs were used: the solid type, the buccal flange type, and the hollow type. Modal analysis was performed to identify the better form. The three types of obturator prostheses were excited by a shaker, and the frequency response functions were recorded on an FFT analyzer to identify their modal shapes. In addition, transient response simulations were carried out, and decay rates of the resultant transient response waves were compared to evaluate the energy absorption after the obturator prosthesis had experienced an impact. The results showed that the modal shapes were closely similar, while the amplitudes at the rests and clasps of the hollow type bulb were the smallest. In the transient response simulation, the decay rates of the hollow type were significantly the highest (p < 0.01). In this study, modal analysis demonstrated that the hollow type obturator prosthesis showed the steepest vibration decay slope, indicating that it might be the best among the three types of bulbs for use in clinical treatments.

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In the in vitro blood-brain barrier (BBB) model, astrocytes have been considered to strengthen the barrier function of brain microvascular endothelial cells (BMECs). Because the blood-nerve barrier (BNB) does not comprise cells equivalent to astrocytes, we hypothesized that the integrity of the BNB is supported by endoneurial pericytes, the only cells comprising endoneurial microvessels other than peripheral nerve microvascular endothelial cells (PnMECs). To estimate the barrier function of in vitro BBB/BNB models, we measured the transendothelial electrical resistance (TEER) and permeability for paracellular diffusion of [car­boxyl-¹⁴C]- inulin across the layers of PnMECs or BMECs co-cultured with pericytes, astrocytes or fibroblasts. When co-cultured with astrocytes, both PnMECs and BMECs showed higher TEER values and significantly lower clearance of inulin. When co-cultured with pericytes, only PnMECs increased the TEER value and lowered the clearance of inulin as effectively as did those co-cultured with astrocytes. Hence, we conclude that endoneurial pericytes may strengthen the BNB function in a PnMEC-specific manner. The TEER values of the PnMEC monolayer challenged by IL-1β, TNFα or VEGF decreased significantly. Based on the present results, the co-culture of PnMECs and pericytes appears to be a useful in vitro BNB model.

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The trend of new patients was investigated at the Clinic for Disabled Patients, University Hospital, Faculty of Dentistry, Tokyo Medical and Dental University for eight years from 1989 to 1996. The purpose of this study was to explore the future role of this specialized clinic. The study revealed the following information: 1.A total of 1,388 new patients, corresponding to 173.5 new patients per year on average, visited the clinic. 2. The percentage of patients aged 30 or more increased. As a result, the mean patient age rose from 40.4 in 1989 to 47.6 in 1996. 3. Referrals accounted for more than 80% of new patients. Medical doctors referred more patients to our clinic than dentists did. 4. While the percentage of disabled patients tended to decrease, the percentage of medically compromised patients increased. 5. The predominant complaint was dental caries. Patients with cardiovascular diseases also complained of gingival bleeding and ill-fitting dentures. The growing percentage of medically compromised patients and the increasing mean age of patients over the eight-year period seems to reflect advances in medical science and the aging society. These tendencies could be more remarkable in the future. Therefore, much closer cooperation between dentists and medical doctors will be required.

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Midkine (MK) is a new member of the family of heparin-binding neurotrophic factors. MK has several important biological effects and plays an important role in the development and survival of neurons. The mechanism by which MK exerts its neurotrophic actions, however has not been sufficiently clarified. To understand the intracellular pathway activated by MK, we established an apoptosis-induction system with the neuronal cell line PC12 and studied the involvement of the mitogen-activated protein kinase (MAPK) cascade in neuroprotective actions of MK. We demonstrate here that MK rescued PC12 cells from apoptosis induced by serum deprivation in a dose-dependent manner. MK also activated extracellular signal­regulated kinases 1 and 2 (ERK1 and ERK2), which are well known as signal transducer acting downstream several receptors. PD98059, an inhibitor of MAPK kinase (MAPKK), inhibited ERK activation and also prevented the trophic effect of MK. These results indicate that MK exerts its neu­roprotective actions mainly via ERK activation.

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In Ghana, West Africa, the prevalence of dual HIV-1 and HIV-2 infections remains to be clarified, and HIV viral load measurement is yet to be established. Conventional assays for HIV-1 RNA measurements have been limited specifically to HIV-1 subtype B, preventing their utilization for Ghana where HIV-1 subtypes A, D and G are prevalent. Therefore, we set out to distinguish the types of HIV infection existing in Ghana so as to determine the extent of actual dual infections, and to measure plasma HIV-1 RNA. Blood samples were collected from 563 sick and healthy Ghanaians who visited hospitals in 1996 and 1997. After T cells were counted, HIV antibody was screened and confirmed by six different commercial assays and one in-house test. Nested PCR was then used to verify HIV-1 and HIV-2 presence by type-specific primers. Plasma HIV-1 RNA was measured by an improved commercial RT-PCR assay, sensitive to all HIV-1 group M subtypes. HIV-1 alone (89%) clearly dominated over HIV-2 alone (2%), and HIV-1 and HIV-2 dual infections were found in 9%. Valid viral load measurements were obtained on test plasma representing the main HIV-1 subtype (A) prevailing in Ghana. A high amount of HIV-1 RNA (5.9 mean log₁₀ RNA copies/ml) was observed in the typical stages of HIV infection represented by groups of CD4⁺ cell counts. We have clarified the seroprevalence of HIV-1 and HIV-2 amongst HIV seropositives, and the high viral load of HIV-1 reflects its influence on AIDS in Ghana.

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