Biomedical subjects

T Kurabayashi

Publications and source records attributed to T Kurabayashi.

At least 55 records · Page 3Linked to original sources

PubMed1998

Lumbar bone mineral density changes during pregnancy and lactation.

OBJECTIVE: To elucidate the change of bone metabolism in the lumbar trabecular and its relationship with serum hormonal changes in pregnancy and lactation. STUDY DESIGN: In a cross-sectional study, we measured the bone mineral density (BMD) of 2-4 lumbar vertebrae of 571 puerperae at days 3-5 postpartum and 341 healthy, non-pregnant women (control subjects) of approximately the same age by dual energy X-ray absorptiometry. In a longitudinal study, we also measured the BMD of 111 puerperae at 3 and 6 months after delivery. RESULTS: The mean BMD at days 3-5 postpartum was significantly lower than that of the control (1.013+/-0.005 vs. 1.032+/-0.006 g/cm2, P = 0.019). The lactating group showed BMD decrement to 95.1+/-0.5% (n = 69) and 94.1+/-0.7% (n = 61) at 3 and 6 months postpartum, respectively, compared with days 3-5 postpartum, and the amenorrhea group showed the same tendency. The non-lactating group and resumption of menses group did not show a BMD decrement postpartum. In the lactating group, serum estradiol was significantly lower than in the non-lactating group at 3 months postpartum, serum prolactin and bone alkaline phosphatase levels were higher than in the non-lactating group at 3 and 6 months postpartum. CONCLUSIONS: Pregnancy may cause a decrease of lumbar BMD, and the lactation and amenorrhea also cause a decrease of BMD. In addition to lactation status, the ovarian dysfunction is one of the factors in bone loss during lactation.

Absorptiometry, Photon↗

PubMed1998

Decrease in the proportion of granulated CD56+ T-cells in patients with a history of recurrent abortion.

We investigated levels of CD56+ T-cells (CD3+ CD56+ cells) in peripheral circulation, which express one of the natural killer (NK) cell markers, by flow cytometry and with monoclonal antibodies in patients with a history of recurrent abortion. We compared these values with those obtained in normal women who were not pregnant as well as in normal pregnant subjects. The percentage of CD56+ T-cells in the peripheral blood of patients with a history of recurrent abortion was less than that in the non-pregnant or pregnant women. These results suggest that CD56+ T-cells with extrathymic properties may be associated with the maintenance of normal pregnancy in humans.

Abortion, Habitual↗

PubMed1998

Simple bone cyst: investigation on the presence of gas in the cavity using computed tomography--review of 52 cases.

OBJECTIVE: The purpose of this study was to evaluate whether gas is present in the cavities of simple bone cysts. STUDY DESIGN: Computed tomographic images of 52 simple bone cyst cases were reviewed and compared with the findings at surgery. RESULTS: Whereas gas was confirmed at the time of surgery in 28 cases, no computed tomographic images indicated the presence of gas in the cavity. Bone expansion was noted in 13 of these 28 cases. CONCLUSIONS: From these findings, we concluded that the presence of gas in the simple bone cyst cavity at surgery has been erroneously interpreted.

Adolescent↗

PubMed1998

Effects of progestins on the metabolism of cancellous bone in aged oophorectomized rats.

The effects of progestins on bone loss in female oophorectomized (ovx) rats were evaluated. One-year-old Sprague-Dawley rats were divided into eight groups: (1) beginning controls (control); (2) sham-operated controls (sham); (3) ovx; (4) ovx treated with estrogen (ovx + E); (5) ovx treated with progesterone (ovx + P); (6) ovx treated with estrogen and progesterone (ovx + E + P); (7) sham group treated with estrogen (sham + E); and (8) sham group treated with progesterone (sham + P). Immediately after surgery, the rats in the hormone injected groups were subcutaneously (s.c.) injected daily for 15 weeks with estrogen (17-beta-estradiol, 0.01 mg/kg in ethanol), or progesterone (4-pregnene-3,20-dione, 0.1 mg/kg in ethanol), or both. At the end of 15 weeks, the bone mineral density (BMD) and bone histomorphometry of the rats' lumbar vertebrae and serological parameters were measured. In the sham, ovx, and ovx + P groups, treatment with progesterone alone did not maintain the BMD in the lumbar vertebrae, but in the ovx + E and ovx + E + P, sham + E, and sham + P groups, progesterone did not inhibit the action of estrogen in the aged ovx rat model. BMD in the sham + P group was significantly higher than in the sham group (270.8+/-10.8 mg/cm2 versus 253.6+/-10.2 mg/cm2; p < 0.01). Bone histomorphometry revealed that bone volume (BV/TV) increased more in the ovx + E + P group than in the ovx + E group and more in the sham + P group than in the sham group, but not significantly. The ovx + E, ovx + E + P, sham + E, and sham + P groups showed no significant differences in the bone formation and resorption parameters, but the bone formation variables tended to increase in the ovx + E + P and sham + P groups. We concluded that progesterone alone cannot prevent bone loss or the increase in turnover after ovx and that estrogen, not progesterone, accounted for all of the bone activity in this study. It seems doubtful that progesterone inhibits the action of estrogen, and in fact may have a beneficial effect on bone metabolism.

Animals↗

PubMed1998

Adverse reactions to nonionic iodine in contrast-enhanced computed tomography: usefulness of monitoring vital signs.

OBJECTIVE: To report on adverse reactions to intravenous nonionic iodine contrast media and evaluate the usefulness of monitoring vital signs. MATERIAL AND METHODS: A prospective study of 1537 consecutive patients who received contrast-enhanced CT with nonionic iodine was performed. Systolic and diastolic arterial blood pressure, pulse rate and arterial blood oxygen saturation were monitored. Severity of adverse reactions was classified as minor, intermediate and severe. RESULTS: A total of 64 adverse reactions developed in 57 patients. The overall prevalence was 3.7% (57/1537). The most common symptom was nausea (18/64) followed by pharyngeal discomfort (11/64). One patient had a severe reaction consisting of prolonged hypotension. Four patients had an intermediate reaction, three transient hypotension or hypertension and one extensive urticaria and facial edema. In two out of four patients who became hypotensive or hypertensive, the reactions developed without any obvious clinical symptoms. CONCLUSIONS: Severe or life-threatening acute adverse reactions to intravenous nonionic iodine contrast media may develop without any obvious clinical symptoms. Monitoring vital signs is very helpful for early detection.

Adolescent↗

PubMed1998

Computed tomography in the diagnosis of maxillofacial mass lesions in younger children.

OBJECTIVE: To evaluate the CT findings of maxillofacial mass lesions in younger children and to discuss the effectiveness of CT in their differential diagnosis. PATIENTS AND METHODS: CT findings of 17 patients (age range, 0 years 5 months to 3 years 3 months) with histopathologically proven maxillofacial mass lesions were retrospectively evaluated. About two-thirds (11/17) comprised congenital lesions or more common lesions in infancy or younger children. RESULTS: Hemangiomas, dermoid cysts and ranulas in this age group presented characteristic CT findings in common with those occurring in adults. Two invasive lesions (melanotic neuroectodermal tumor and aggressive fibromatosis) had irregular margins and the latter also showed aggressive bone destruction. Two angiomas had irregular margins. A fibrosarcoma showed expansile bone destruction but had a regular margin. CONCLUSION: CT was useful in demonstrating the extent of maxillofacial mass lesions in children and for surgical treatment planning. Although some invasive lesions could be correctly diagnosed on the basis of CT, its diagnostic value in differentiating malignant from benign maxillofacial lesions in younger children was limited.

Ameloblastoma↗

PubMed1998

Thrombosed varix in the submandibular space.

Thrombosed varix in the oral region often appears as a pigmented mass in the mucosa simulating a hemangiomatous lesion. It rarely occurs in the deeper orofacial region. We report a case of thrombosed varix in the submandibular space with symptoms of a tumor. The clinical symptoms and MRI and CT findings are discussed. The clinical symptoms were not characteristics. High signal intensity on CT (80 HU) and a concentric signal distribution on CT and MRI may suggest a thrombosed varix.

Chin↗

PubMed1998

Laparoscopic management of rudimentary horn pregnancy. A case report.

BACKGROUND: Rudimentary uterine horn pregnancy is a very rare condition. Removal of a rudimentary horn is required as soon as a pregnancy is confirmed because most pregnancies in a rudimentary uterine horn rupture in the first or second trimester. CASE: A 22-year-old woman was admitted to our hospital because an ectopic pregnancy was suggested by ultrasonographic examination at another hospital. A rudimentary uterine horn pregnancy was suspected from transvaginal ultrasonography. The patient was treated with laparoscopic surgery at 7 weeks of gestation. The pregnant rudimentary horn was removed laparoscopically by use of an automatic stapling device. The postoperative course was uneventful. CONCLUSION: This is the first report of laparoscopic resection of a pregnant rudimentary uterine horn. Laparoscopic management of such a pregnancy may reduce operating time and peritoneal damage.

Abortion, Induced↗

PubMed1997

Primary choriocarcinoma of the uterine cervix: clinical, MRI, and color Doppler ultrasonographic study.

Primary choriocarcinoma of the uterine cervix was diagnosed in a 38-year-old Japanese woman 4 months after a normal vaginal, term delivery. The patient had experienced irregular genital bleeding for several weeks. A cervical polypoid tumor was detected by visual inspection 4 months after delivery. Magnetic resonance imaging (MRI) and color Doppler ultrasonography revealed a hypervascular tumor (6 cm) in the uterine cervix. The patient's urinary level of human chorionic gonadotropin (hCG) was 128,000 IU/L. Histological examination of a biopsy of the cervical tumor showed choriocarcinoma. After completion of 2 courses of chemotherapy, the patient underwent a total abdominal hysterectomy. Histological examination of uterus showed no evidence of choriocarcinoma. At present, the patient is free of disease. MRI and color Doppler ultrasonography were useful for diagnosis by detecting the abundant blood flow and central necrosis of the cervical tumor.

Adult↗

PubMed1997

Differential diagnosis of tumours of the minor salivary glands of the palate by computed tomography.

OBJECTIVE: To define the CT criteria for differentiating malignant from benign tumours of the minor salivary glands of the palate and to evaluate their accuracy. PATIENTS AND METHODS: CT findings of 63 patients with histopathologically proven minor salivary gland tumours of the palate (23 malignant, 40 benign) were retrospectively evaluated. RESULTS: Aggressive bone destruction was a specific finding of malignant tumours, but was seen in only 57% (13/23) of this series. Extension into the pterygopalatine fossa was observed in seven malignant and one benign tumour. Calcifications within a tumour were observed in four cases, all of which were malignant. These three CT findings were significantly more frequent in malignant tumours. Using any one of these as the criterion for the malignancy, the sensitivity was 78% (18/23), specificity 98% (39/40) and accuracy 90% (57/63). CONCLUSION: Malignant tumours of the minor salivary glands of the palate are very likely to show any or all of aggressive bone destruction, extension into the pterygopalatine fossa and calcification, whereas benign tumours can almost always be correctly diagnosed by their absence.

Calcinosis↗

PubMed1997

Periosteal new bone formation in the jaws. A computed tomographic study.

OBJECTIVES: To investigate the diagnostic significance of a periosteal reaction (PR) in diseases of the jaws. METHODS: The frequency of PR was investigated in 1142 patients who had undergone CT of the maxilla or mandible. The pattern of PR was categorized as either parallel, irregular, spicule or Codman's triangle. We examined the relationship of the pattern of PR to the specific disease categories of osteomyelitis, trauma, cysts, benign tumours and malignant tumors. RESULTS: Seventy patients were found to have PR. It was found in 40% of cases with osteomyelitis and 15% of malignant tumors. The only benign lesion was an eosinophilic granuloma. There were no cysts. The frequency of PR was higher in younger patient and in those with sarcomas or bone metastases compared with those with carcinomas. Ninety-one percent of the patients with osteomyelitis showed single or multi-layered PR parallel to the cortical bone, while 61% of those with malignant tumors had a spicule pattern. With the exception of Codman's triangle, none of the PR patterns were specifically associated with any one disease category. When the PR pattern was combined with the pattern of cortical bone destruction, 90% of the patients with PR could be correctly assigned to one or other of the four disease categories of osteomyelitis, trauma, benign lesion or malignant tumor. CONCLUSIONS: The pattern of PR on CT in combination with the pattern of the cortical destruction of the cortex is useful in differentiating osteomyelitis from malignant tumors.

Adult↗

PubMed1997

Computed tomography in the diagnosis of buccal space masses.

OBJECTIVE: To evaluate the CT features of buccal space masses. PATIENTS AND METHODS: Fifty-three cases of buccal space masses were reviewed retrospectively. The diagnosis was confirmed histopathologically in all except two. CT images were assessed for the number, location, internal architecture and margin of the lesions and their relation to the surrounding structures. RESULTS: The series comprised 44 tumors (33 benign and 11 malignant) and nine non-tumorous lesions. Buccal gland tumors were all found adjacent to the outer surface of the buccinator, in contrast to epidermoid cysts and accessory parotid tumors which were completely separate from it. Hemangiomas were characterized by multiple masses or the presence of phleboliths. When ill-defined margins, violation of fascial planes and aggressive bone destruction were used as the criteria for the malignancy, only seven out of 11 malignant tumors were correctly diagnosed (sensitivity 64%). CONCLUSION: CT was useful in demonstrating the presence and location of the masses in the buccal space and sometimes in the differential diagnosis. For a mass of uncertain cause in the buccal space, a buccal gland tumor is the most likely diagnosis. The value of CT in differentiating malignant from benign buccal space lesions is limited.

Adolescent↗

PubMed1997

Direct intratumoral gene transfer of the herpes simplex virus thymidine kinase gene with DNA-liposome complexes: growth inhibition of tumors and lack of localization in normal tissues.

To constitute the site-specific expression of the herpes simplex virus thymidine-kinase (HSV-TK) gene in tumor cells, we have assessed the promoter function of the simian virus 40 (SV40) promoter and the 5'flanking region of c-erbB-2 gene using a luciferase-expressing reporter plasmid. After the transfection of the luciferase plasmid directed by the promoter region of c-erbB-2 gene, a large amount of luciferase activity was observed in c-erbB-2-expressing cells (Colo201, MCF-7, and HEC1-A), while none was detected in cells with no expression of c-erbB-2 protein (HRA and KF cells). On the other hand, a high level of luciferase activity was detected in all tumor cell lines tested, when the transfection was performed with SV40 promoter. The repeated transfection of the liposome-conjugated HSV-TK gene regulated by the SV40 promoter or by the promoter region of c-erbB-2 gene with cultivation in 100 micrograms/ml of aciclovir for 5 days in vitro resulted in growth inhibition for all four cell lines examined or for only c-erbB-2-expressing cells in the presence of SV40 promoter or c-erbB-2 promoter, respectively. Finally, direct injection of the DNA-liposome complex into established tumors in the presence of 50 mg/kg of aciclovir led to significant tumor volume reduction in all three tumors tested when SV40 promoter was employed. However, this anti-tumor effect was noted only in c-erbB-2-positive cells (Colo201 cells) upon intratumoral injection of HSV-TK gene regulated by c-erbB-2 promoter. In the case of intratumoral gene transfer, foreign DNA was detected in only one of seven mice by polymerase chain reaction (PCR) analysis performed 7 days following injection. When PCR analysis was carried out at 14 or 21 days following injection, no DNA signal was found at all. However, DNA was detected in several normal tissues at all three times tested in the case of intravenous injection. No abnormalities were seen in histologic examinations of normal tissues or in serum biochemical parameters following DNA liposome delivery. These results suggest that the direct gene transfer of HSV-TK gene regulated by tumor-specific transcriptional units may be one of the most clinically promising of the selective genetic strategies against cancer.

Acyclovir↗

PubMed1997

Characteristics of Escherichia coli HB101 and Pseudomonas putida PpY101 harboring a recombinant plasmid with tandem insertion of the mercury resistance operon.

We constructed the plasmid pSUPmer2 by inserting tandem copies of the mercury resistance (mer) operon into a broad host range-vector, and introduced it into Escherichia coli HB101 and Pseudomonas putida PpY101 to increase their mercury resistance. Strains harboring plasmid pSUPmer2 had higher mercury resistance and mercuric reductase activity than those strains harboring the plasmid pSUPmer which had one copy of the mer operon. Mercury resistance of P. putida PpY101 was significantly increased by tandem insertion of the mer operon.

Cell Division↗

PubMed1997

Immunosuppressive therapy for recurrent aborters with positive antiphospholipid antibodies and alteration of 6ketoPGF1 alpha/TXB2 ratio.

Twelve women (13 pregnancies) with antiphospholipid antibodies (APA) who had suffered from two or more recurrent spontaneous abortions or fetal deaths and had successful pregnancy outcomes after immunosuppressive therapy were studied. APA titers were determined by enzyme-linked immunosorbent assay against cardiolipin, phosphatidyl serine and phosphatidyl inositol. Plasma levels of 6ketoprostaglandin F1 alpha (6ketoPGF1 alpha) and thromboxane B2 (TXB2) were determined by radioimmunoassay. All of the 13 pregnancies resulted in term delivery. None of the 13 patients suffered from pregnancy-induced hypertension, and only one showed intrauterine growth retardation. A significant decrease of APA titer was observed after immunosuppressive therapy. The 6ketoPGF1 alpha/TXB2 ratios before the therapy, after it and at the 1st, 2nd and 3rd trimesters of pregnancy were 0.62 +/- 0.398, 0.88 +/- 0.106, 0.84 +/- 0.550, 1.25 +/- 0.834 and 0.67 +/- 0.413, respectively. The ratio at the 2nd trimester was significantly higher than that before the therapy (P < 0.05, paired t-test, n = 9). The results indicate that the immunosuppressive therapy affected the physiological balance between thromboxane A2 and prostacyclin, and improved clinical symptoms such as recurrent fetal wastage.

6-Ketoprostaglandin F1 alpha↗

PubMed1996

Physiological dose of estrogen regulates extrathymic T cells in female mice.

Bilateral ovariectomy was performed in female C57BL/6 mice to investigate whether extrathymic T cells in the liver are regulated by physiological doses of estrogen or progesterone. Extrathymic T cells were identified using a two-color immunofluorescence test for CD3 and interleukin-2 receptor beta-chain (IL-2R beta) antigens. The T cells were identified as intermediate CD3+ cells with a high expression of IL-2R beta. It was further demonstrated that the proportion and number of intermediate CD3+ cells decreased in response to ovariectomy, an effect that was countered by estrogen administration. These results suggest that the activation of extrathymic T cells may be regulated by physiological levels of estrogen.

Animals↗

PubMed1996

Effect of estriol on bone loss in postmenopausal Japanese women: a multicenter prospective open study.

OBJECTIVES: To assess the effects of oral estriol on the bone mineral density (BMD) and bone metabolism in postmenopausal women. METHODS: Seventy-five natural postmenopausal women with a BMD of more than 10% below the peak bone density were treated for 50 weeks with 2 mg/day estriol (E3) cyclically and 0.8 g/day of calcium lactate continuously. BMDs at L2-L4 were measured by dual energy X-ray absorptiometry (DXA). RESULTS: The BMD increased 1.79% (p < 0.01 vs. pretreatment) after 50 weeks, accompanied with decrease of biochemical markers of bone turnover. With regard to climacteric symptoms, Kupperman's menopausal index improved (p < 0.01 vs. pretreatment) after 5 weeks of treatment. As to the incidence of adverse events genital bleeding was observed in only 8.0% of the subjects. Endometrial histology and cytology showed neither abnormalities nor hyperplasia during and after the treatment. CONCLUSIONS: Estriol prevented postmenopausal bone loss and improved climacteric symptoms effectively with low incidence of genital bleeding.

Bone Density↗

PubMed1996

The beta 3-adrenergic receptor gene Trp64Arg mutation is overrepresented in obese women. Effects on weight, BMI, abdominal fat, blood pressure, and reproductive history in an elderly Australian population.

A tryptophan to arginine (Trp64Arg) mutation in the beta 3-adrenergic receptor (beta 3-AR) gene has been implicated in diabetes and obesity. We investigated the relationship of the beta 3-AR gene mutation with total body weight, BMI, central abdominal fat, blood pressure (BP), and reproductive history in 686 elderly subjects (429 women, 257 men; mean age 69.8 +/- 6.9 [+/-SD] years) from a cross section of a normal population in Australia. About 14% of the test population were heterozygote carriers of the Trp64Arg mutation; however, significant effects on clinical parameters were only observed in women. The frequency of the mutation was significantly increased in obese women compared with lean women (BMI > or = 27: 20% compared with BMI < 27: 11%, P = 0.02). Significantly higher total body weight (67.5 +/- 12.9 vs. 64.1 +/- 12.2 kg, P = 0.03) and BMI (26.3 +/- 4.7 vs. 25.1 +/- 4.5 kg/m2, P = 0.03) was observed in heterozygote women compared with normal subjects (homozygous for tryptophan). Central abdominal fat was not significantly different, except in women under 70 years, where heterozygotes had 16% higher abdominal fat compared with normal subjects. Female heterozygotes had significantly higher diastolic BP, even after adjustment for age and BMI (88.9 +/- 11.1 vs. 84.2 +/- 10.8 mmHg, P = 0.003) and a longer reproductive life, with an earlier menarche (12.8 +/- 1.3 vs. 13.4 +/- 1.5 years, P = 0.006), a higher gravidity (4.4 +/- 2.4 vs. 3.5 +/- 2.1, P = 0.01), and higher parity (3.8 +/- 2.0 vs. 3.0 +/- 1.9, P = 0.005). Clearly, the beta 3-AR mutation has pleiotrophic effects on a number of physiological systems, including BMI, BP, and reproductive history, perhaps suggesting evolutionary reasons for its maintenance in the population.

Aged↗