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Biomedical subjects

S Nakata

Publications and source records attributed to S Nakata.

At least 145 records · Page 8Linked to original sources
PubMed1996

[A case of prostate cancer diagnosed one and half year after retropubic prostatectomy for benign prostatic hypertrophy].

A 77-year-old male patient underwent retropubic prostatectomy for benign prostatic hypertrophy. Fourteen months after operation, a hard nodule was palpated on the left lobe on digital examination. Transrectal needle biopsy was performed, and the pathological diagnosis was poorly differentiated adenocarcinoma of the prostate. It was one and half year after prostatectomy that we diagnosed prostate cancer (stage D2).

Adenocarcinoma↗
PubMed1995

Evidence that graft coronary arteriosclerosis begins in the early phase after transplantation and progresses without chronic immunoreaction. Histopathological analysis using a retransplantation model.

The histopathological features of chronic rejection and its initiation were assessed using rat heterotopic heart transplantation and retransplantation models. Fully allogeneic or minor, non-MHC antigen-mismatch heart grafts transplanted into recipient rats treated with a short course of FK506 showed long-term survival but developed graft atherosclerosis after 40 days posttransplantation. Retransplantation of allografts back into the original donor strain did not prevent graft atherosclerosis if the grafts had resided in the primary recipient for up to 5 days; residence in the primary allogeneic recipient for less than 4 days did not result in graft atherosclerosis in the secondary recipient. Short-course administration of FK506 did not affect the production of these changes. Graft coronary arteriosclerosis begins between 3 and 5 days posttransplantation and progresses without continuous allogeneic immunological drive. The present findings will provide a new means by which to approach the analysis of development of chronic allograft rejection.

Animals↗
PubMed1995

Anemia-inducing substance from plasma of patients with advanced malignant neoplasms.

Patients with advanced malignant neoplasms develop anemia and immunosuppression. During an attempt to identify the causes, we have found that plasma from such patients makes RBCs more fragile in hypotonic buffer, according to results obtained with a coil planet centrifuge. Plasma from these patients suppresses mitogen-stimulated lymphocyte proliferation. In this study, we identified the substance with these effects as a protein. During two-dimensional gel electrophoresis, two isomers with M(r) 50,000 and slightly different isoelectric points near 6.0 were found. Cell fractionation showed that these proteins were in both the cytosol and the nuclear fraction of cells in neoplasms. Another protein with the same antigenicity and a M(r) 100,000 found in the nuclear fraction of cells in neoplasms.

Anemia↗
PubMed1995

Molecular characterization of a human calicivirus with sequence relationships closer to animal caliciviruses than other known human caliciviruses.

cDNA clones were produced from a morphologically typical human calicivirus (HuCV) in stool specimens collected in 1982 during an outbreak of gastroenteritis in Sapporo, Japan. The cDNA clones were generated separately in two laboratories by reverse transcriptase-polymerase chain reaction (RT-PCR) using primers 35 and 36 derived from Norwalk virus. The RT-PCR product from six specimens was of the predicted size, had a continuous protein encoding frame on the positive strand, and contained GLPS and YGDD amino acid motifs at the predicted distance from the primers. RT-PCR amplification with primer 35 and a HuCV/Sapporo-specific primer 36 of four HuCV/Sapporo-positive stool specimens from a 1986 Houston day care center outbreak yielded products with 93% nucleotide and 99% predicted amino acid sequence identity with the HuCV/Sapporo strain from the 1982 outbreak. The HuCV/Sapporo strains are genetically distinct from previously characterized HuCVs and more closely related to known animal CVs than other known HuCVs.

Animals↗
PubMed1995

Extraordinary high rate of HTLV type II seropositivity in intravenous drug abusers in south Vietnam.

Serum specimens (n = 1899) were assayed for infections with HTLV-I, HTLV-II, and HIV-1 in seven classified groups of normal healthy controls, children, pregnant women, prostitutes, intravenous drug abusers, patients under going hemodialysis, and hemophiliacs in South and North Vietnam. Surprisingly, 125 of 954 samples from South Vietnam exhibited seropositivity for HTLV-II and 119 of these belonged to the group of IVDAs (n = 200). The remaining six positives were a healthy control, a prostitute, two children, and two patients under going hemodialysis. Two IVDAs who were seropositive for HTLV-I and 10 of 15 seropositives for HIV-1 were also positive for HTLV-II in this population. In contrast, no seropositives to any of the viruses were detected in the North Vietnamese samples (0 of 945). The HTLV-II-seropositive IVDAs exhibited increased seropositivity with age compared with HIV-1 seropositivity in the population, and there was no statistical relation between seropositivity for HTLV-II and HIV-1. The HTLV-IIs in South Vietnam IVDAs appeared, by subtype-specific peptide ELISA, to be a mixture of both subtypes a and b, with subtype a predominant. It seems possible that HTLV-II may have been introduced into this population from IVDAs from the United States during the Vietnam conflict, but in a period prior to, or early in, the introduction of HIV-1 to IVDAs.

Adult↗
PubMed1995

Functional masticatory evaluation in hemifacial microsomia.

The features of hemifacial microsomia with unilateral condylar hypoplasia in a 9-year-old female patient were analysed in a multidisciplinary fashion. Cephalometric roentgenograms revealed malformation of the mandible, with the right condylar process being smaller than the left. In addition, the right maxillary alveolar process was underdeveloped. Closed view radiography with oblique lateral transcranial projection (by modified Schüller's method) of the temporomandibular joint revealed an anterior dislocation of the condyle on the unaffected side. Computed tomography (CT) of the masticatory muscles demonstrated that the medial pterygoid muscle on the affected side, unlike the other muscles, was larger than that on the unaffected side. The surface electromyographic activities of the temporal and masseter muscles and reduction of the maximum bite force on the affected side during clenching corresponded with the CT findings. The hypertrophy of the medial pterygoid muscle on the affected side was considered likely to be a compensatory adjustment to keep the mandible centred. A three-dimensional study of the movement of the mandible revealed that the condyle on the affected side moved vertically and that the rotational centre was located antero-inferior to the condylar process during maximum jaw opening and closing movements. These findings suggested lack of articular guidance. Moreover, the unaffected condylar process showed considerable backward movement during retrusion and ipsilateral excursion of the mandible. The mandibular head on the unaffected side showed obvious protraction during all jaw movements, which might have induced the overgrowth of the condylar head on the unaffected side in this growing child.

Alveolar Process↗
PubMed1995

Epidemiological characteristics of prostate cancer in Gunma Prefecture, Japan. Gunma University Urological Oncology Study Group.

BACKGROUND: Prostate cancer is rare in Asia, but the number of patients is increasing in Japan. We conducted an epidemiological study of prostate cancer in Gunma Prefecture, Japan, to investigate the trends and characteristics of the disease. METHODS: The subjects were 1,411 prostate cancer patients newly diagnosed between 1985 and 1992, and 656 patients who died from prostate cancer between 1981 and 1992. The incidence and mortality rates were calculated by year, demographic region and age. RESULTS: The yearly incidence rate showed an increase but the mortality rate showed no marked fluctuations. There was no significant difference between urban and rural districts in either incidence or mortality rate. The incidence rate tended to be high in the northern part of the prefecture, but no marked variation in mortality rate was seen. The incidence and mortality rates in districts with a history of manganese mining were high compared to those in districts without mining. In contrast, the incidence and mortality rates in districts with a history of zinc mining were comparatively lower. Both incidence and mortality rates showed a marked increase with age. The age-specific incidence showed a double logarithmic relationship to age. CONCLUSIONS: The increase of the yearly incidence rate might be due to changes in lifestyle and environmental factors, improved diagnostic techniques, and increased awareness among the general public regarding prostate disease. Further investigation is needed to clarify the pattern and the causes of regional differences in the incidence and mortality rates. The possibilities that managanese and zinc might be related to prostatic carcinogenesis are suggested.

Age Distribution↗
PubMed1995

Relation between postpacing T wave changes and myocardial scintigraphic characteristics in patients with ventricular demand pacemaker.

The aim of this study was to elucidate the cause of T wave changes after ventricular pacing using thallium 201 single photon emission computed tomography (Tl-SPECT). Tl-SPECT was performed in 20 patients with sick sinus syndrome who had negative T wave after ventricular pacing and had had a ventricular demand pacemaker (VVI) implanted. Patients who have stenotic coronary arteries were excluded from the study. From the analysis of Tl-SPECT, extent score was calculated as the ischemic region. Data in patients with SSS were compared with those in 20 normal controls (NC). Thallium perfusion defects in patients with VVI were observed and distributed mainly in apex and inferior regions on the polar map. The extent score in patients with VVI was significantly higher than that in NC (56.4 +/- 21.6% vs 3.2 +/- 6.4%, P < 0.01). The washout rate of thallium 201 in the defect area was significantly lower in patients with VVI than in NC (27.4 +/- 10.2% vs 46.8 +/- 12.3%, P < 0.01). These results suggest that T wave changes after ventricular pacing are closely related to myocardial ischemia.

Aged↗
PubMed1995

[An analysis of familial prostate cancer].

BACKGROUND: Clinical and pathological features of familial prostate cancer patients were examined. METHODS: We compared 7 pairs (14 patients) of familial prostate cancer patients (Group F) with those of 1741 prostate cancer patients diagnosed in around Gunma Prefecture between 1987 and 1993 (Group G). Relative survival rates were compared because the average age was different in two groups. RESULTS: In Group F and Group G, age at diagnosis ranged from 54 to 86 and 47 to 97 years old, and the averages were 68.1 +/- 8.5 (S.D.) and 74.2 +/- 8.3, respectively. The average age tended to be younger in Group F. The ratio of early stage cancer tended to be higher and that of poorly differentiated cancer tended to be lower in Group F. The 3- and 5-year relative survival rate was 82.4% and 57.6% in Group F, and 84.3% and 73.9% in Group G, respectively. The 5-year survival rate tended to be lower in Group F, but almost no difference was observed between two groups on the whole. In Group F, of 6 patients whose causes of death were clear, 4 (66.7%) died of prostate cancer, while in Group G, of 398 patients whose causes of death were elaar, 224 (56.3%) died of prostate cancer. Family history of other cancer sites was positive in 3 of 6 families in Group F. CONCLUSIONS: Familial prostate cancer patients tended to be young, in early stage and low ratio of poorly differentiated cancer.

Aged↗
PubMed1995

The equine pericardial valved conduit and current strategies for pulmonary reconstruction.

In the period from 1976 to February 1995, 268 cases underwent extracardiac conduit repair (ECR), or direct reconstruction of the pulmonary artery. Of these 268 patients, 64 had a valved Dacron conduit, 143 received handmade valved equine pericardial conduits (Xenomedica), 24 had autologous fresh pericardial conduits, and 37 cases had pulmonary artery reconstruction by direct anastomosis without the use of tubular conduits. Hospital mortality in each group showed gradual improvement chronologically; 20.3% in the Dacron group, 9.8% in the equine conduit group, 4.2% in the autologous pericardial conduit group, and 5.4% in the direct anastomosis group, and the mortality rate was significantly higher in the Dacron group (P = .0261). Late death was seen in 7 of 51 (13.7%) in the Dacron group, 12 of 129 (9.3%) in the equine group, 1 of 23 (4.3%) in the autologous pericardial conduit, and none in the direct anastomosis group (P = .1263). Actuarial survival rates of the patients in the Dacron and equine conduit groups showed better survival in the latter without statistical significance: 75.0%, 83.2% at 5 years, and 69.7%, 80% at 10 years, respectively. However, actuarial survival rates among short-term survivors in the Dacron and equine conduit groups remained the same: 87.5%, and 88.7% at 10 years. Our current strategy in this entity is autologous tissue reconstruction of the pulmonary artery either by direct anastomosis or autologous pericardial conduit. Of 30 cases with transposed great arteries or truncus arteriosus, direct anastomosis could be performed in 19 (63.3%) since January 1992.(ABSTRACT TRUNCATED AT 250 WORDS)

Anastomosis, Surgical↗
PubMed1995

[Bypass grafting of left subclavian artery to descending thoracic aorta for relative stenosis of bypass graft after total correction for type A IAA with VSD].

A 4-year-old child underwent one-stage total correction for type A IAA with VSD in 1975 as the first successful case in Japan. At age 21, a gradual rise in her upper limb pressure to 190 mmHg prompted repeat catheterization, which showed a pressure gradient across the EPTFE graft of 58 mmHg. Under general anesthesia in the right lateral position, the patient's left thorax was reopened. The EPTFE graft had undergone patchy calcific degeneration and was significantly hardened. An 18-mm Toray graft preclotted with fibrin glue was anastomosed to the left subclavian artery in side-to-end fashion. Its distal end was anastomosed to the descending aorta distal to the EPTFE bypass during a 20-minute aortic occlusion. The postoperative recovery was uneventful and the pressure gradient between the upper and lower limbs fell to 0 at discharge. We chose this method for reoperation of type A IAA and CoA because of the reduced need for dissection and better effectiveness.

Adult↗
PubMed1995

[Two cases of successful arterial switch operation for double outlet right ventricle associated with straddling and cleft mitral valve].

We successfully performed an anatomical repair for double outlet right ventricle associated with straddling and cleft mitral valve in two patients. In both patients position of the anterior and posterior papillary muscles was found to be normal. Therefore, all staddled mitral component was detached. The mitral valve competency was achieved by suture-closure of the cleft and annuloplasty. This procedure facilitated intraventricular re-routing from the left ventricle to the pulmonary artery. Then arterial switch was performed. Postoperative course was uneventful and no significant mitral valve regurgitation was found in either patient postoperatively. This procedure can be a good option in patients with double outlet right ventricle associated with straddling mitral valve.

Child, Preschool↗