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S Nakamura

Publications and source records attributed to S Nakamura.

At least 289 records · Page 16Linked to original sources
PubMed2001

A new approach to enhancement of bone formation by electrically polarized hydroxyapatite.

An electrical field may affect osteogenesis. Since we found that hydroxyapatite (HA) ceramics may be polarizable, we hypothesized that electrically polarized HA may foster production of new bone in vivo. Both polarized and non-polarized HA ceramics were inserted into the subperiosteum spaces at the parietal bone area of rats. After 2, 4, and 8 weeks, the implant sites were examined histologically. Morphometric analysis revealed that new bone formation was accelerated on the negatively charged surface of the polarized HA (N-surface) at 2 weeks. The newly formed bone approached maturation at 4 weeks and was thicker on the N-surface than in the controls. By 8 weeks, newly formed bone in the controls was almost the same as that on the N-surface. These findings suggest that polarized HA is biocompatible and that bone formation on the N-surface is enhanced in the early stage of bone healing.

Animals↗
PubMed2001

Apoptosis and proliferation of myoepithelial cells in atrophic rat submandibular glands.

This study was designed to determine whether apoptosis and proliferation of myoepithelial cells occur in atrophic rat submandibular glands. The excretory duct of the right submandibular gland was doubly ligated with metal clips. The atrophic right submandibular glands removed after 1-28 days of duct ligation were investigated using immunohistochemical double staining for actin as a marker for myoepithelial cells and proliferating cell nuclear antigen (PCNA) as a marker for proliferating cells, double staining for actin immunohistochemistry, nick end-labeling (TUNEL) as a marker for apoptotic cells, and transmission electron microscopy (TEM). A few PCNA- and no TUNEL-positive myoepithelial cells were found in the control submandibular glands taken from animals with no operation. In the experimental glands, PCNA-positive myoepithelial cells were common 2 and 3 days after duct ligation and then decreased in number. TUNEL-positive myoepithelial cells appeared at 2 days and were observed most frequently at 5 days. Apoptotic myoepithelial cells were also identified by TEM. These observations suggest that both apoptosis and proliferation of myoepithelial cells occur, especially in the early phase of atrophy, in the rat submandibular gland.

Actins↗
PubMed2001

Inflammatory pseudotumor of lymph nodes: clinicopathologic and immunohistological study of 11 Japanese cases.

We report 11 Japanese cases of inflammatory pseudotumor (IPT) of the lymph node. There were 7 males and 4 females with ages ranging from 5 to 68 years (median; 48). Only 2 patients had systemic lymphadenopathy, and all others had involvement of only 1 lymph node group. Constitutional symptoms such as fever were present in 8 patients and laboratory abnormalities were detected in 5. All patients recovered and were alive and well after 2 to 180 months (median; 32 months). Histologically, the process mainly involved the connective tissue framework of the lymph node, secondarily spreading into the lymph node parenchyma and the perinodal tissue. It was characterized by a storiform growth pattern of myofibroblasts, marked vascularity with associated vascular lesions, and a polymorphous reactive cellular infiltrate in a collagen-rich stroma. An immunohistochemical study revealed numerous myofibroblasts, histiocytes, and vascular endothelial cells expressing vascular endothelial growth factor (VEGF) in 6 cases. It was suggested that VEGF may be involved, in part, in the induction of the angiogenesis of IPT. Moreover, the present study indicates that follicular dendritic cell sarcoma, nasal T/natural killer cell lymphoma, and anaplastic large cell lymphoma should be added to the differential diagnosis from IPT of the lymph node. Int J Surg Pathol 9(3):207-214, 2001

Adolescent↗
PubMed2001

Follicular lymphoma of the salivary gland: a clinicopathological and molecular study of six cases.

To clarify the clinicopathologic, immunohistologic, and genotypic features of follicular lymphoma arising from the salivary glands, we examined 20 cases of operatively resected primary salivary gland lymphoma and identified 6 such cases. There were 4 women and 2 men with ages ranging from 38 to 64 years (median 50 years). The tumor arose from the parotid gland in 4 cases and the submandibular gland in the remaining 2. Four patients were stage IE and 2 were stage IIE-1. The median follow-up period was 49 months and all patients were alive and well at the time of going to press. Histologically, 5 patients were follicular lymphoma grade 2, and 1 was grade 3. In all specimens in noninfiltrating salivary gland tissue, there was periductal lymphocytic infiltration near the lymphoma. Moreover, myoepithelial sialoadenitis was noted in 2 lesions. An immunohistochemical study revealed all 6 cases were CD10+, CD79a+, bcl-6+, CD3-, CD5-, CD21-, CD23-, and CyclinD1-. The tumor cells expressed bcl-2 in 3 cases and p53 oncoprotein in 4 cases. Two cases revealed clonal bands with polymerase chain reaction (PCR) assay for the immunoglobulin heavy (IgH) gene. The bcl-2/IgH translocation at the major breakpoint region was detected in 1 case (16%). We found a relatively high incidence of follicular lymphomas (30%) in salivary gland lymphomas. Among the mucosa-associated lymphoid tissue (MALT) system, follicular lymphomas appeared to occur frequently in the salivary glands as well as the duodenum and skin. Moreover, follicular lymphoma arising from the salivary glands appeared to have some of the characteristics of MALT-type lymphoma including indolent prognosis, presence of myoepithelial sialoadenitis, and rarity of the BCL-2 gene rearrangement.

Adult↗
PubMed2001

Cerebrospinal fluid membrane-bound tissue factor and myelin basic protein in the course of vasospasm after subarachnoid hemorrhage.

No marker that predicts accurately the time of occurrence of cerebral vasospasm due to subarachnoid hemorrhage (SAH) has been reported. In the present study, membrane-bound tissue factor (mTF) and myelin basic protein (MBP) concentrations in cerebrospinal fluid (CSF) were evaluated as a predictor of the time of occurrence of cerebral vasospasm. The mTF and MBP concentrations were measured in the CSF from 28 patients with SAH due to ruptured aneurysm. Serial assays were performed from day 4 to day 14 after SAH. CSF mTF and MBP concentrations from days 5 to 9 correlated with the volume of cerebral infarction due to vasospasm and outcome three months after SAH. From the serial assays, CSF mTF measurements predicted the time of occurrence and severity and irreversibility of symptoms due to vasospasm. In conclusion, CSF mTF is predictive of the occurrence and the recovery of cerebral vasospasm, while CSF MBP is only an indicator of severity of brain damage due to vasospasm.

Adult↗
PubMed2001

Role of cadherins in maintaining the compartment boundary between the cortex and striatum during development.

In ventricular cells of the mouse telencephalon, differential expression of cadherin cell adhesion molecules defines neighbouring regions; R-cadherin delineates the future cerebral cortex, while cadherin-6 delineates the lateral ganglionic eminence. By using cell labelling analyses in the whole embryo culture system, we demonstrated that the interface between R-cadherin and cadherin-6 expression is a boundary for cell lineage restriction at embryonic day 10.5. Interestingly, when a group of cells with exogenous cadherin-6 were generated to straddle the cortico-straital boundary by electroporation at embryonic day 11.0, ectopic cadherin-6-expressing cortical cells were sorted into the striatal compartment, and the reverse was the trend for ectopic R-cadherin-expressing striatal cells. Although cadherin-6 gene knockout mice engineered in this study showed no obvious phenotype in telencephalic compartmentalisation, the preferential sorting of ectopic cadherin-6-expressing cells was abolished in this mutant background. Thus, the differential expression pattern of cadherins in the embryonic telencephalon is responsible for maintaining the cortico-striatal compartment boundary.

Animals↗
PubMed2001

A novel series of thromboxane A2 synthetase inhibitors with free radical scavenging and anti-peroxidative activities.

A novel series of indoline derivatives with imidazole and carboxyl moieties were synthesized and evaluated for their thromboxane A2 (TXA2) synthetase inhibiting, radical scavenging and anti-peroxidative activities. Among the compounds synthesized, 3-[5-substituted-3-[2-(imidazol-1-yl)ethyl]indolin-1-yl]propionic acids showed free radical scavenging activity and inhibitory effects on lipid-peroxidation of rat brain homogenate and on arachidonate-induced TXA2-dependent aggregation of rabbit platelets. The anti-platelet and anti-peroxidative activities were related to the lipophilicity of the 5-substituent. The 5-hexyloxy derivative (13) showed about 35-fold higher inhibitory activity on TXA2 synthesis than that of ozagrel and about 100-fold higher activity on lipid peroxidation than that of alpha-tocopherol. Compound 13 showed in vivo anti-thrombotic effect in mice and ex vivo anti-peroxidative activity in rats.

Animals↗
PubMed2001

Plasma monocyte chemoattractant protein-1 antigen levels and the risk of restenosis after coronary stent implantation.

Monocyte chemoattractant protein-1 (MCP-1) plays a fundamental role in monocyte recruitment and has been implicated in atherosclerosis. The present study tested the hypothesis that increased levels of MCP-1 are associated with an increased risk for restenosis post stent implantation. The plasma MCP-1 antigen levels were measured pre-stenting, and at 24 and 48 h and 6 months post stenting in 41 patients with stable exertional angina (SEA) who had undergone successful stent implantation. Nineteen patients with chest pain syndrome were selected as a control group. Initial plasma MCP-1 antigen levels (mean +/- SE, pg/ml) in the patients with SEA were significantly higher than those in the control group (852.3+/-51.4 vs 418.2+/-26.7, p<0.001). The patients with SEA were divided into 2 groups based on follow-up angiographic findings: 17 patients with restenosis (R group); 24 patients without restenosis (N group). The lesion was significantly longer in the R group than in the N group (p<0.03). Plasma MCP-1 antigen levels at pre-stenting were not significantly different between the 2 groups (820.6+/-69.1 in the R group vs 874.7+/-73.8 in the N group). Serial changes of plasma MCP-1 levels were plotted as percent changes from the initial levels (mean +/- SE, %) and were significantly higher in the R group than in the N group at 48 h and at 6 months post stent implantation (104.6+/-4.8 vs 89.2+/-3.4, p<0.01, 109.6+/-11.2 vs 98.5+/-5.0, p<0.05). The study concludes that MCP-1 production at stented coronary arterial sites is associated with an increased risk for restenosis post stent implantation.

Aged↗
PubMed2001

Males in rural Bangladeshi communities are more susceptible to chronic arsenic poisoning than females: analyses based on urinary arsenic.

Spot urine samples were collected from the inhabitants of two rural communities in northwestern Bangladesh. We compared arsenic levels in the urine samples ([As](u); n = 346) with those in water from tube wells ([As](tw); range < 1-535 microg/L; n = 86) on an individual basis. The small variation of [As](u) within subjects and highly positive correlation with [As](tw) indicate that [As](u) is a useful indicator of exposure. Analyses of [As](u) showed that creatinine correction was necessary, that [As](u) only reflected recent exposure, and that there were substantial interindividual differences for a given [As](tw) level. To evaluate the toxic effects of arsenic exposure, we constructed a system for rating skin manifestations, which revealed distinct sex-related differences. Comparison of males and females in the same households confirmed that skin manifestations were more severe in the males, and in the males of one community a dose-response relationship between [As](u) and the degree of skin manifestation was evident. The results of this study indicate that [As](u) in spot urine samples can be used as an exposure indicator for As. They suggest that there might be sex-related, and perhaps community-related, differences in the relationship between [As](u) and skin manifestations, although several confounding factors, including sunlight exposure and smoking habits, might contribute to the observed sex difference. The existence of such differences should be further confirmed and examined in other populations to identify the subpopulations sensitive to chronic arsenic toxicity.

Adult↗
PubMed2001

A histological study of the necrotic area after transtrochanteric anterior rotational osteotomy for osteonecrosis of the femoral head.

We studied nine patients who had had a transtrochanteric anterior rotational osteotomy, as developed by Sugioka, for osteonecrosis of the femoral head. At a mean of 2.5 years after the initial operation we carried out a histological study of the previously necrotic femoral head which had not shown collapse of the new primary weight-bearing site. In seven joints, there was proliferation of fibrous tissue in the dead trabeculae with vascular ingrowth. New bone covering dead trabeculae created the characteristic appearance of 'creeping substitution'. However, these changes were limited and did not extend over the entire necrotic area. Dead bone remained in all the cases. In the other two heads we did not observe proliferation of fibrous tissue or vascular ingrowth, only dead trabeculae and dead bone marrow.

Adult↗
PubMed2001

Clinical significance of coronary flow to the infarct zone before successful primary percutaneous transluminal coronary angioplasty in acute myocardial infarction.

STUDY OBJECTIVE: To assess the effect of coronary flow to the infarct zone before primary coronary angioplasty on hospital complications in patients with acute myocardial infarction (MI). DESIGN: Consecutive case series analysis. SETTING: Coronary-care unit in a university hospital. PATIENTS: Two hundred sixty-four consecutive patients with ST-elevation acute MIs who had successful primary percutaneous transluminal coronary angioplasty. INTERVENTIONS: Coronary angiography on hospital admission and serial echocardiography. MEASUREMENTS AND RESULTS: The status of infarct-related artery flow before primary angioplasty was evaluated on hospital admission. Left ventricular wall motion and pericardial effusions were studied by echocardiography. One hundred ninety patients had total occlusions (Thrombolysis in Myocardial Infarction [TIMI] flow grade, 0 to 1) in the infarct-related artery (group 1), and 74 patients had antegrade flow (TIMI flow grade, 2 to 3) [group 2] before undergoing primary angioplasty procedures. When group 1 was subdivided into two groups (for the presence and absence of collateral flow), the patients with total occlusions and no collateral flow had a higher incidence of left ventricular aneurysmal wall motion (11% vs 1%, respectively; p = 0.03) and pericardial friction rub (15% vs 3%, respectively; p = 0.03) than did those in group 2. Moreover, those patients with total occlusions and no collateral flow had higher incidences of pericardial effusion (34% vs 17%, respectively; p = 0.02; and 34% vs 9%, respectively; p < 0.01) and in-hospital mortality (8% vs 1%, respectively; p = 0.04; and 8% vs 1%, respectively; p = 0.06) than did those patients in the other two groups. CONCLUSIONS: Despite successful primary angioplasty, the absence of antegrade flow in the infarct-related artery and collateral flow to the infarct zone before angioplasty resulted in a higher incidence of in-hospital complications.

Aged↗
PubMed2001

Morning granulocytopenia in a case of Graves' disease.

A 65-year-old woman with Graves' disease presented marked diurnal changes in white blood cell (WBC) and granulocyte counts. Granulocyte count was low and sometimes decreased to 0.2-0.3 x 10(9)/l in the early morning and increased in the afternoon irrespective of her thyroid status. She did not develop sore throat or fever during the investigation period. The present study indicates that these unusual diurnal changes in WBC and granulocyte counts should be considered in the differential diagnosis of agranulocytosis in Graves' disease patients treated with an antithyroid drug.

Aged↗
PubMed2001

Senile plaques in an aged western lowland gorilla.

Senile plaques (SPs) were found in the cerebral cortex of a 44-year-old Western lowland gorilla (Gorilla gorilla gorilla). All the SPs were obtained as dense assemblies consisting of fibrous materials by silver impregnation, but were not detected by Congo red. More SPs were detected by immunostaining for amyloid beta protein (A beta) and a half of A beta-positive-SPs were also immunoreactive for apolipoprotein E. Moreover, all SPs were immunoreactive for A beta 42 and A beta 43, but not for A beta 40. SPs also did not contain A beta precursor protein-positive structures. These findings suggested that SPs in this case were diffuse plaques. To our knowledge, this is the first report of SPs in the gorilla.

Aging↗
PubMed2001

The present status of management for infertility in Miyagi Prefecture, Japan.

To summarize the current management of infertility in Japan, a questionnaire survey was administered. A mail-survey method was used, and surveys were sent to 126 obstetrical and/or gynecological medical facilities in Miyagi Prefecture. The respondents included 86 facilities (68.3%). The majority of participants employed routine assessments, and their records included basal body temperature (98.8%), semen analysis (88.8%), and tubal patency tests (78.8%). Laparoscopic diagnosis, however, was uncommon (15.8%). With respect to treatment, surgical procedures, especially endoscopic procedures, were not generally carried out in addition to medicinal treatment. Sixty-one percent of the respondents performed intrauterine insemination, however assisted reproductive technology (ART) was provided by a few participants, for example, in vitro fertilization-embryo transfer was available at 11.3% of facilities. In self-assessment, the median pregnancy rates for the group undergoing laparoscopy and that not were significant different (30% and 20%, respectively), and those of the group undergoing ART provided and that not were significant different (35% and 20%, respectively). In conclusion, there are various differentials in the methods of diagnosis and treatment of infertility in the medical facilities today, and the outcomes are not always satisfactory. For appropriate management of infertile couples, it will be necessary to more closely manage cooperation between primary care doctors and reproductive specialists.

Adult↗
PubMed2001

Measles epidemiology and outbreak investigation using IgM test in Laos.

Following the Pan American Health Organization (PAHO) recommendation on measles elimination, the Western Pacific Region of WHO (WPR) is emphasizing accelerated measles control programme especially since the achievement of polio eradication in WPR in 2000. This includes upgraded surveillance and mass measles vaccination campaign for children aged 9 months to 4 years. However, there are limited scientific evidences supporting the feasibility of this programme in Laos. To examine measles elimination feasibility in the country, we conducted measles outbreak investigation using immunoglobulin M (IgM). From March 1999 to March 2000, we conducted 7 outbreak investigations. At the outbreak sites, we examined clinical manifestations of cases and collected individual data. About five blood samples were drawn from each outbreak, and IgM antibodies to measles were tested. Of 7 investigated outbreaks, 5 were confirmed as measles, one was chickenpox, and one occurred in the inaccessible area due to flooding. In a village of high land Lao, blood drawn was refused. Of 185 cases, 64 (34.6%) cases were immunized, and 110 (59.5%) were unimunized. The estimated vaccine efficacy is 67.9%. The number of measles cases among school-aged children was 74 (40.0%), which represented 2.5% of the total population in investigated villages. Our findings showed various difficulties of the surveillance and the limited outcomes of mass measles vaccination campaign under the accelerated measles control programme by WPR. Efforts to improve cold chain as well as increasing routine immunization coverage must be the priority of measles control.

Antibodies, Viral↗
PubMed2001

Papillary squamous cell carcinoma of the oral mucosa: immunohistochemical comparison with other carcinomas of oral mucosal origin.

Papillary squamous cell carcinoma (PSCC) is a poorly described variant of squamous cell carcinoma, and may be confused with verrucous carcinoma of the head and neck. To add to existing knowledge of this rare tumor, we describe two cases of PSCC arising in the oral mucosa. The lesions were composed of exophytic proliferation of atypical to overtly malignant cells similar to those of conventional squamous cell carcinoma, and invasion into the superficial region of the underlying fibrous tissue was seen in the form of islands and cords of malignant cells. Immunohistochemical assessment of cellular proliferative activity showed a significantly high mean percentage of Ki-67 expression in comparison with verrucous carcinoma, but there was no significant difference of Ki-67 expression among PSCC, conventional squamous cell carcinoma and microinvasive squamous cell carcinoma. These results suggest that the biological behavior of PSCC is analogous to that of SCC.

Aged↗
PubMed2001

[CHF arising after low dose THP-COP chemotherapy in an elderly patient with malignant lymphoma].

A 76-year-old woman was admitted with a one-month history of low grade fever and dizziness. She had a palpable right supraclavicular lymph node. Abdominal ultrasonography showed swollen lymph nodes around the abdominal aorta. A specimen from the right supraclavicular lymph node showed malignant lymphoma (diffuse large B cell type). We started chemotherapy according to the low-dose THP-COP protocol (pirarubicin, cyclophosphamide, vincristine and prednisolone) on the 31st hospital day. Since no adverse effects were detected after two low-dose cycles, the patient received a third course with standard doses on the 87th hospital day. The total dose of pirarubicin was 72 mg/m2. Two days after the third course started, she suffered from dyspnea caused by congestive heart failure. A chest X-ray showed advanced cardiomegaly, severe congestion and bilateral pleural effusion. These conditions improved with transvenous administration of diuretics, a vasodilator and phosphodiesterase inhibitor. In this case, congestive heart failure developed even though the total dose of pirarubicin was lower than in previous reports of this complication. When the THP-COP protocol is indicated in elderly patients, cardiotoxicity should be monitored even if the total dose of pirarubicin is very low.

Aged↗