Biomedical subjects

K Okamura

Publications and source records attributed to K Okamura.

At least 109 records · Page 6Linked to original sources

PubMed1999

Serologic study of human parvovirus B19 infection in pregnancy in Japan.

OBJECTIVES: To clarify the relationship between hydrops fetalis and parvovirus outbreaks in the community, seroprevalence of B19 antibody among women of childbearing age, and adverse effects of intrauterine B19 infection. METHODS: Sera were collected from 168 cases of hydrops fetalis which were diagnosed between 1987 and 1997 in Miyagi prefecture, Japan, from 232 healthy pregnant women in 1987 and 277 healthy pregnant women in 1997 in Miyagi, and from 48 women infected with B19 during pregnancy. The sera were examined for B19 IgG and IgM antibodies by enzyme-linked immunosorbent assay and for B19 DNA by polymerase chain reaction. The number of cases of erythema infectiosum in Miyagi had been monitored each month. RESULTS: Thirteen of the 168 cases of hydrops fetalis were found to be caused by intrauterine B19 infection and 12 of the 13 cases clustered in two periods of outbreaks of erythema infectiosum in the community. The positive rates of B19 IgG antibody between 1987 and 1997 were significantly different: 33% in 1987 and 46% in 1997. Nine of the 48 women infected during pregnancy showed adverse effects of the fetus: eight hydrops fetalis and one early abortion with positive B19 DNA. The fetal death rate (>12 weeks of gestation) among them was 15% (7/48), far higher than the calculated 1% among the general population. The nine mothers with adverse fetal outcomes had contact with the infectious source at the 16 weeks of gestation or earlier. CONCLUSIONS: These data clearly showed a relationship between hydrops fetalis and parvovirus outbreaks in the community, and it may be important to follow the seroprevalence for an extrapolated period time to predict occurrence of hydrops fetalis caused by B19. Also the data indicated that the gestational week infection occurred is the most important determinant of an adverse effect to the fetus as described previously.

Adolescent↗

PubMed1999

Parvovirus B19 infection induces apoptosis of erythroid cells in vitro and in vivo.

OBJECTIVE: intrauterine parvovirus B19 infection is related to non-immune hydrops fetalis, the pathogenesis of which is based on the strict tropism of B19 for erythroid precursor cells and the massive destruction of the infected erythroid cells, although the mechanism of beta19-induced cytotoxicity has not been studied in detail. The purpose of this study is to provide empirical evidence that beta19 induces apoptosis of erythroid cells both in vitro and ill vivo. METHODS: we analysed culture cells infected in vitro by B19 and tissues of nine cases of hydrops fetalis caused by B19 intrauterine infection by histological and biological methods. RESULTS: cells infected iil vitro by B19 showed nuclear changes characteristic of apoptosis by light microscopic examination and DNA extracted from the infected cells was fragmented. Electron microscopic examination showed the nuclei of infected cells contained crescent-shaped clumps of heterochromatin with increased density and double staining with anti-B1 9 antibody and terminal deoxynucleotidyl transferase (TdT)-mediated deoxyuridine triphosphate-digoxigenin nick-end labeling (TUNEL) confirmed apoptosis of individual cells. Tissues of cases of hydrops fetalis caused by B19 contained erythroid cells with nuclear inclusions and characteristic nuclear changes of apoptosis by light microscopy. The double-staining confirmed apoptosis of erythroid cells in the tissues. Immunohistochemical analysis with antibodies against cellular factors involved in apoptosis showed that caspase3, p53 and p21 were positive in infected cells.

Apoptosis↗

PubMed1999

Higher cholesterol and insulin levels in pregnancy are associated with increased risk for pregnancy-induced hypertension.

Hyperinsulinemia and dyslipidemia are known to be associated with essential hypertension but their role in pregnancy-induced hypertension remains unclear. We performed a case-control study comparing cholesterol, insulin, and glucose levels in the early third trimester of pregnancy among 31 women who developed pregnancy-induced hypertension (PIH) (either preeclampsia [n = 6] or nonproteinuric gestational hypertension [n = 25]), with 31 women remaining normotensive through pregnancy. As compared with women remaining normotensive, women subsequently developing PIH had higher fasting cholesterol levels (279 v 247 mg/dL; P = .02) and higher fasting insulin levels (13.3 v 7.9 microU/mL; P = .03), although fasting glucose levels and levels of glucose and insulin after glucose load did not differ significantly between groups. In comparing hypertensive subgroups, fasting insulin levels were significantly higher among women who subsequently developed preeclampsia, but not among those subsequently developing nonproteinuric gestational hypertension. Although women developing PIH had higher pregravid body mass index (25.1 v 22.6 kg/m2, P = .06), fasting cholesterol and insulin levels were associated with risk for PIH even after adjustment for body mass index and age (relative risks for one unit increase, respectively: 1.02 (P = .03) and 1.12 (P = .03). Higher fasting cholesterol and insulin levels in mid- to late pregnancy are associated with increased risk for PIH. These observations support a role for insulin resistance in the development of this complication of pregnancy.

Case-Control Studies↗

PubMed1999

Interleukin-10 level in sputum is reduced in bronchial asthma, COPD and in smokers.

Interleukin (IL)-10 is a potent regulatory cytokine that decreases inflammatory responses. This study investigated whether IL-10 levels in the airway are decreased in chronic airway inflammation associated with asthma or chronic obstructive pulmonary disease (COPD). Sputum was obtained from 12 healthy nonsmokers, 10 healthy smokers, 16 asthmatic patients and seven patients with COPD by means of the sputum-induction method. The IL-10 level was measured via enzyme-linked immunosorbent assay and immunocytochemical analysis. The IL-10 level in sputum was significantly lower in asthma and COPD patients and healthy smokers compared with that in healthy nonsmokers (nonsmokers, 68.0+/-11.3; smokers, 45.3+/-7.8; asthma, 26.7+/-4.0; COPD, 18.0+/-2.3 pg x mL(-1); p<0.05 for nonsmokers versus the other groups). The percentage of IL-10-positive cells in the sputum was also significantly lower in asthma and COPD and in smokers (nonsmokers, 13.2+/-1.7; smokers, 6.4+/-1.8; asthma, 5.4+/-3.5; COPD, 3.5+/-1.6%; p<0.05 for nonsmokers versus the other groups). The IL-10-positive cell appeared morphologically to be the macrophage. These data suggest that the reduced level of interleukin-10 within the airways plays a role in the pathogenesis of chronic airway inflammation in asthma and chronic obstructive pulmonary disease.

Adult↗

PubMed1999

A comparative study of endoscopic trigonoplasty for vesicoureteral reflux in children and in adults.

BACKGROUND: Endoscopic trigonoplasty is an experimental therapy for vesicoureteral reflux. We investigated differences in surgical results between children and adults. METHODS: Endoscopic trigonoplasty was performed on 51 patients and 15 pediatric and 21 adult patients were included in this study. The children accounted for 27 cases of refluxing ureter (grade II, 8; III, 14; IV, 4; V, 1) and the adults for 28 cases (I, 4; II, 18; III, 4; IV, 2). There was a greater proportion of bilateral disease and a higher average degree of reflux in the children's group. RESULTS: We found no significant differences in operative time, complications, analgesics usage, the duration of the indwelling catheter and hospital stay. Our follow up at 3 months showed that the reflux had ceased in 19 of 27 cases (70%) in the children's group and in 27 of 28 cases (96%) in the adults' group. The next follow up at 12 months showed that there was no reflux in 16 of 27 cases (59%) in 15 children and in 17 of 23 adult cases (74%). Trigonal splitting caused recurrence of reflux greater than grade II, in two children (13%) affecting four ureters and in three adults (14%) affecting four ureters. CONCLUSIONS: Endoscopic trigonoplasty has proved to be equally less invasive in children and in adults, but vesicoureteral reflux was less often resolved in children. This suggests that the greater original distance between the ureteral orifices and the greater thickness of the detrusor muscle favor the adult patient. For children, a new surgical concept is needed to increase cessation rate of vesicoureteral reflux.

Adult↗

PubMed1999

Closure of mouth of bladder diverticulum via endoscopic transvesico-transurethral approach.

We successfully treated bladder diverticula in two patients using the endoscopic transvesico-transurethral approach. The mouth of the diverticulum was closed in two layers under pneumobladder, using two percutaneous ports placed into the bladder as well as the urethral route. This operation was performed 2 to 3 months after the bladder outlet obstruction was relieved by transurethral resection or incision of the prostate. The patients were able to void with a minimum of residual urine. The endoscopic transvesico-transurethral approach provided satisfactory vision.

Aged↗

PubMed1999

Conservation and diversification of MHC class I and its related molecules in vertebrates.

The elucidation of the complete peptide-binding domains of the highly polymorphic shark MHC class I genes offered us an opportunity to examine the characteristics of their predicted protein products in the light of the latest advance in the structural studies of the MHC class I molecules. The results suggest that the fundamental characteristics in the T-cell recognition of the MHC class I molecule/peptide complex are expected to have been established at the early stage of the vertebrate evolution. The elucidation of the typical classical class I molecules from fishes and also of some MHC class I-related molecules may help us-to explore the common denominator of the ancient class I molecules.

Amino Acid Sequence↗

PubMed1999

The effect of mechanical trauma on the tooth germ of rat molars at various developmental stages: a histopathological study.

Intrusive trauma was experimentally applied to the tooth germ at different developmental stages in the rat first molar. The tooth germ at the earliest (postnatal day 1, initiating stage of enamel matrix formation) and the latest (postnatal day 10, calcifying stage of preformed enamel matrix) developmental stages studied showed localized enamel hypoplasia as a direct sequela of trauma. The tooth germs in which enamel matrix was rapidly thickening (postnatal days 3, 5, 7) and had not yet started to calcify showed the most intense and extensive injuries to the formation and structural organization of both enamel and dentin. As for indirect effects secondary to trauma, tooth germ dislocation was observed chiefly in tooth germs at the same developmental stages, frequently resulting in ankylosis. The present experimental model may be helpful for clarifying the histogenesis of traumatic changes in the developing tooth germ.

Ameloblasts↗

PubMed1999

Characterization of breast masses by dynamic enhanced MR imaging. A logistic regression analysis.

PURPOSE: To identify features useful for differentiation between malignant and benign breast neoplasms using multivariate analysis of findings by MR imaging. MATERIAL AND METHODS: In a retrospective analysis, 61 patients with 64 breast masses underwent MR imaging and the time-signal intensity curves for precontrast dynamic postcontrast images were quantitatively analyzed. Statistical analysis was performed using a logistic regression model, which was prospectively tested in another 34 patients with suspected breast masses. RESULTS: Univariate analysis revealed that the reliable indicators for malignancy were first the appearance of the tumor border, followed by the washout ratio, internal architecture after contrast enhancement, and peak time. The factors significantly associated with malignancy were irregular tumor border, followed by washout ratio, internal architecture, and peak time. For differentiation between benignity and malignancy, the maximum cut-off point was to be found between 0.47 and 0.51. In a prospective application of this model, 91% of the lesions were accurately discriminated as benign or malignant lesions. CONCLUSION: Combination of contrast-enhanced dynamic and postcontrast-enhanced MR imaging provided accurate data for the diagnosis of malignant neoplasms of the breast. The model had an accuracy of 91% (sensitivity 90%, specificity 93%).

Adult↗

PubMed1999

Effect of meal timing after resistance exercise on hindlimb muscle mass and fat accumulation in trained rats.

To study the effect of meal timing after exercise on body composition, 20 male rats were assigned to either a group fed a meal right after exercise (R) or a group fed a meal 4 h after exercise (L). Resistance exercise (squatting) was conducted from 6:00 to 7:00, 3 d/wk for 10 wk. Meals were consumed from 7:00 to 8:00 and from 19:00 to 20:00 for R, and from 11:00 to 12:00 and from 19:00 to 20:00 for L. The room was lighted from 7:00 to 19:00. After 10 wk, the body weight was comparable between the groups. The hindlimb muscle weight was higher in R than in L by 6% (p < 0.05), whereas the sum of the weight of perirenal, epididymal, and mesenteric adipose tissues was lower in R than in L by 24% (p < 0.01). The soleus lipoprotein lipase (LPL) activity was higher in R than in L by 70% (p < 0.01), and the activity negatively correlated with the adipose tissue weight (r = -0.49, p < 0.05). These results suggest the possibility that ingesting a meal right after resistance exercise may contribute to an increase in the muscle mass and to a decrease in the adipose tissue compared to ingesting a meal several hours later.

Adipose Tissue↗

PubMed1999

Effect of timing of meal intake after squat exercise training on bone formation in the rat hindlimb.

We hypothesized that bone acquisition was affected by the timing of meal intake after resistance exercise training. This was based on the following previous results: 1) Nutrient intake right after exercise resulted in an increase in muscle mass and a decrease in abdominal fat mass as well as muscle protein synthesis when compared to the intake of a meal later after the exercise; and 2) body composition has been proposed to be a good predictor of bone mass. To substantiate our hypothesis, 20 male rats were assigned to either a group fed a meal right after squat exercise (R) or a group fed a meal 4 h after the exercise (L). The 10-wk training program consisted of approximately 70% of one repetition maximum for each animal, 15 repetitions per set, 10 sets per day, 3 d per week. As a result, hindlimb muscle mass in the R group was greater (p < 0.05) than that in the L group and abdominal fat mass was less (p < 0.01) in the R group as compared to the L group, regardless of there being no significant difference in body weight between the groups. Bone volume in the tibia (p < 0.01) and femur (p < 0.05) were both significantly greater in the R group than in the L group. Bone mineral content index (BMCI) and bone mineral density index (BMDI) in the tibia of the R group were significantly (p < 0.05) greater than the corresponding values of the L group. The greater BMCI and BMDI in the tibia were positively and significantly (p < 0.05) related with hindlimb muscle mass, but not with abdominal fat mass. There was no significant difference in BMCI and BMDI in the femur between the groups. These results suggest that the R regimen may contribute to increased bone acquisition in the tibia as compared to the L regimen, and this effect is partly due to the enlargement of muscle mass in the R group as compared to the L group.

Adipose Tissue↗

PubMed1999

[A case of advanced gastric cancer successfully treated by neoadjuvant chemotherapy with CPT-11, CDDP and 5-FU].

A patient with advanced gastric cancer was treated with combined administration of CPT-11 CDDP and 5-FU before operation. CPT-11 was given intravenously at a dose of 30 mg/m2/day on day 1 and day 8. At the same time, 5 mg/m2/day CDDP and 350 mg/m2/day 5-FU were infused for 2 weeks. The patient experienced no other adverse reaction than a mild degree of nausea. Histological examination of the resected specimen revealed complete disappearance of cancer cells both in the stomach and the regional lymphnodes.

Adult↗

PubMed1999

[Clinical study of retroperitoneal lymph node dissection for patients with advanced germ cell tumors].

We performed retroperitoneal lymph node dissection (RPLND) on 14 patients (IIA: 1, IIB: 4, IIIA: 3, IIIB2: 2, IIIC: 4) with testicular and one with retroperitoneal germ cell tumor at the Nagoya University Hospital between 1986 and 1997. According to the international germ cell consensus classification, 4 patients were classified as "good-prognosis", three as "intermediate-prognosis" and eight as "poor-prognosis". RPLND was performed on 12 patients with the tumor marker levels normalized preoperatively and on three without the marker normalization. The mean surgical time was 510 (195-1, 125) minutes and the mean bleeding volume was 3,806 (100-12,598) g. The surgical time and bleeding volume were correlated with the size of the tumor in the body axis. Intraoperative complications occurred in 5 (33%) out of 15 patients: injury of renal artery (2), renal vein (1), ureter (1) and common iliac artery (2). Postoperative complications occurred in 2 patients: ileus (2) and lower extremity edema resulting from resection of the inferior vena cava (1) and would dehiscence (1). Of the 8 patients whose completely resected retroperitoneal tumors were necrosis/fibrosis or teratoma (psCR), 6 achieved survival with no evidence of disease (NED). Among 4 patients, whose tumor was not completely resected but pathologically diagnosed as necrosis/fibrosis or teratoma (pCR), NED without recurrence was achieved in 2 and also in one with resection of relapsed teratoma 2.5 years after RPLND. All three patients with cancer tissues pathologically retained in the resected tumors (sCR or psIR), consequently died of the disease. In six patients with relapse, the initial sign was elevation of the tumor marker levels, which was noted more than 30 days postoperatively in 2 patients with psCR and 7 to 15 days in 4 patients without psCR. We believe that RPLND is needed to examine the pathology and to predict the prognosis of the poor-risk patients with NSGCT. Careful dissection of vessels is needed to reduce vascular complications.

Adolescent↗

PubMed1999

[Three cases of urinary retention caused by uterine leiomyoma].

Three females with urinary retention caused by uterine leiomyoma are reported. The patients were 35, 48 and 50 years old. In each patient, transabdominal ultrasonography showed a large and homogeneous mass located in the retrovesical space, compressing the bladder. Pre-operative computed tomographic (CT) scan and magnetic resonance (MR) imaging revealed uterine leiomyoma which severely compressed the bladder from the posterior wall to the urethra. The urinary symptoms completely resolved in all patients following total hysterectomy, and postoperative uroflowmetry demonstrated normal voiding.

Adult↗

PubMed1999

A randomized comparative study of the Bandloop versus the standard loop for transurethral resection of the prostate.

PURPOSE: The Bandloop is a new electroresection loop that is broader than the standard loop and thickens from front to back. We compared the safety and efficacy of the Bandloop to the conventional loop electrode for transurethral prostatectomy. MATERIALS AND METHODS: A randomized prospective study was performed on 53 patients with lower urinary tract symptoms and estimated prostatic volume greater than 30 ml. on transrectal ultrasonography. The Bandloop was used in 25 cases (Bandloop group) and standard loop was used in 28 (standard group). Surgical outcomes, including International Prostate Symptom Score, resected prostatic weight, operative time, uroflowmetry, post-void residual urine, postoperative catheterization period, time to disappearance of macrohematuria, and serial changes of hemoglobin and urinalysis, between the 2 groups were compared. RESULTS: A total of 23 Bandloop and 28 standard loop cases were evaluable. There was no difference in preoperative estimated prostatic volume (mean 44.7 versus 47.8 ml.), resected prostatic weight (36.5 versus 29.4 gm.) or operative time (61 versus 60 minutes) between the 2 groups. The ratio of resected weight-to-estimated prostatic volume was significantly greater in the standard group (81.4% versus 61.9%). There was no difference in postoperative catheterization period (3.3 versus 3.4 days) or time to disappearance of macroscopic hematuria (5.0 versus 5.0 days). Postoperative changes in symptom score (-15.1 versus -15.9), maximum flow rate (11.8 versus 16.3 ml. per second at 12 weeks) and residual volume (-31.6 versus -48.6 ml. at 12 weeks) demonstrated no significant difference between the 2 groups. There was no difference in intraoperative and postoperative bleeding estimated by serial changes in serum hemoglobin and urinalysis after surgery. No patient had major complications or required transfusion. CONCLUSIONS: Transurethral prostatectomy using the Bandloop is as safe and effective in achieving subjective and objective improvements as standard transurethral prostatectomy. However, our randomized study indicates that the Bandloop offers no advantage compared to the standard loop electrode for transurethral prostatectomy.

Aged↗

PubMed1999

[Clinical study of high-dose chemotherapy with peripheral blood stem cell transplantation for poor-risk germ cell tumor].

Between January 1997 and December 1998, six patients with germ cell tumor were treated with high-dose CEC: carboplatin (1,500 mg/m2), etoposide (1,200 mg/m2) and cyclophosphamide (100 mg/kg), followed by peripheral blood stem cell transplantation (PBSCT) at Nagoya University Hospital. Four patients received one cycle of high-dose CEC and two received two cycles. The reasons why the high-dose CEC was administered included: 1) refractory to the induction chemotherapy (AFP/beta-HCG elevated during the induction chemotherapy or prolonged half-life of each marker) in three patients, 2) relapse in two patients, and 3) consolidation in one with unresectable mediastinal residual tumor. There were no treatment-related deaths and grade 1 hepatotoxicity occurred in one (17%) patient. The median duration (range) from PBSCT until a granulocyte count of 500/microL and a platelet count of 50,000/microL was 8.5 (8-11) and 11 (9-16) days, respectively. Of the six patients studied, 5 responded to the treatment; two achieved a complete response (CR) and three achieved a partial response (PR). One patient achieving a CR and two achieving a PR remained in complete remission after 23 to 24 months of follow-up, while the remaining patients with a CR, a PR and an incomplete response died of the disease. High-dose CEC could be administered without serious toxicity but the effectiveness of high-dose CEC for the poor-risk patients with germ cell tumor needs to be further investigated.

Adolescent↗

PubMed1998

Giant leiomyosarcoma of the remnant stomach: report of a case.

We describe herein the case of a 73-year-old woman who developed a giant leiomyosarcoma in the remnant stomach 4 years after undergoing a distal gastrectomy for gastric carcinoma. Abdominal ultrasonography and computed tomography revealed a huge tumor, 22 cm in maximum diameter, in the left hypochondrial region. Selective abdominal angiography showed a hypervascular tumor fed by the branches of the splenic artery and left inferior phrenic artery. The tumor arose from the posterior wall of the remnant stomach, and demonstrated marked extragastric growth and direct invasion of the pancreas, transverse colon, and diaphragm on the left side. Total resection of the remnant stomach with en bloc resection of these adjacent organs was subsequently carried out. We reviewed the Japanese literature on this extremely rare tumor and evaluated its clinical profile. In comparison with leiomyosarcoma of the unresected stomach, that of the remnant stomach more frequently showed endogastric-type growth and was accompanied by ulceration of the gastric mucosa. The prognosis of patients with leiomyosarcoma of the remnant stomach appears to be greatly affected by the presence of liver metastases and the tumor diameter, similar to that of patients with leiomyosarcoma of the unresected stomach.

Aged↗

PubMed1998

Treatment of pancreas head carcinoma in a 91-yr-old man. Report of a case successfully treated with pylorus-preserving pancreatoduodenectomy.

The case of a 91-yr-old man who had a tumor of the pancreas head successfully resected is reported. He was admitted to our hospital because of obstructive jaundice, and then percutaneous transhepatic biliary drainage (PTBD) was performed. Cholangiography via PTBD tube showed marked stenosis of the bile duct in the head of the pancreas. Endoscopic retrograde pancreatography (ERP) showed obstruction of the main pancreatic duct in the head of the pancreas, and carcinoma in the head of the pancreas was diagnosed. Abdominal angiography showed stenosis of the celiac trunk caused by compression from the median arcuate ligament, but no tumor stain or encasement in the pancreas was detected. Because the patient had lived an extremely healthy life and had no serious concurrent disease before admission, laparotomy was performed. The tumor in the head of the pancreas was about 2 cm in diameter and restricted inside the pancreas. Pylorus-preserving pancreatoduodenectomy (PpPD) with regional lymph node dissection was performed. The tumor was 1.5 cm in its maximal diameter, and histopathologically was diagnosed as an invasive ductal carcinoma of the pancreas with moderately differentiated tubular adenocarcinoma. The patient had an uneventful postoperative course and now, 3 yr after surgery, he is doing very well and leading a normal daily life.

Aged↗