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Biomedical subjects

H Kawamoto

Publications and source records attributed to H Kawamoto.

At least 127 records · Page 7Linked to original sources
PubMed1997

[A case of cerebral arteriovenous malformation with accidental migration of a microcatheter during endovascular procedure].

This is a report of a case of cerebral arteriovenous malformation with accidental breakaway of a microcatheter during endovascular embolization. A 25-year-old female suddenly suffered severe headache. CT scan demonstrated intraventricular hemorrhage, and the angiogram revealed right parieto-occipital AVM. We performed endovascular embolization using a flow-directed microcatheter (1.5F BALT MAGIC catheter) 2 weeks after onset, and the microcatheter broke accidentally and a fragment of the soft tip migrated to the distal posterior cerebral artery during the procedure. Although we tried to retrieve the catheter using several retrieval devices, we failed. Two days after the procedure we undertook surgical treatment. The migrated catheter was recognized in a small feeding artery which was stretched tightly, so retrieval was very risky. Using hemoclips for trapping the part of the catheter which remained in the feeder, we were able to retrieve it by cutting the feeder. Flow-directed microcatheters are very usefull in endovascular procedures, but it is necessary to handle them carefully in accord with sufficient knowledge of their use and handling methods.

Adult↗
PubMed1996

Isolation of the most immature population of murine fetal thymocytes that includes progenitors capable of generating T, B, and myeloid cells.

Thymus cells of murine fetuses at day 12 of gestation are exclusively of the CD3-CD4-CD8-CD44+CD25- phenotype, which is known as a hallmark of the most immature subset of thymus cells. In the present study, we show that day 12 fetal thymus (FT) cells express Fc gamma RII/ III (FcR) at a broad range of levels on their surface. The FcR+ FT cells seem to represent T lineage cells, because a large majority of them express the T lineage specific transcription factors TCF-1 and GATA-3 as well as CD3 epsilon in the cytoplasm. Also shown is that the FcR- population contains progenitors capable of developing into not only T cells but also B and myeloid cells, whereas FcR+ progenitors are mostly committed to the T lineage. These findings indicate that thymic T lineage cells express FcR on their surface at the earliest stage of differentiation, and thus FcR is a useful marker in isolating the most immature population of murine FT cells.

Animals↗
PubMed1996

Involvement of transcription factors TCF-1 and GATA-3 in the initiation of the earliest step of T cell development in the thymus.

Flow cytometric and immunocytochemical analyses of murine fetal thymus (FT) cells with antibodies to various surface markers and transcription factors reveal that the synthesis of TCF-1 and GATA-3 protein begins simultaneously in a fraction of the most immature population of FT cells, which have the phenotype of CD4-CD8-CD44+CD25-. No TCF-1-producing cells is found in the fetal liver (FL). In CD44+CD25- FT cells, the production of TCF-1 is immediately followed by intracellular expression of CD3 epsilon. It is also found that the T cell development from FL, but not FT, progenitors in the FT organ culture system is severely inhibited by the addition of antisense oligonucleotides for either TCF-1 or GATA-3. These results strongly suggest that TCF-1 and GATA-3 play essential roles in the initiation of the earliest steps of T cell development in the thymus.

3T3 Cells↗
PubMed1996

Requirement of cell interactions through adhesion molecules in the early phase of T cell development.

We investigated the role of adhesion molecules in T cell development. A large proportion of murine fetal thymus (FT) cells obtained at Day 13 of gestation, which are c-kit+, express the adhesion molecules Pgp-1, VLA-4, LFA-1, and ICAM-1 on their surface at high levels. The expression profiles of these adhesion molecules resemble quite well those on c-kit+ cells in fetal liver (FL). The level of expression of these molecules on FT cells declines with the embryonal age and becomes mostly negative by birth except for LFA-1. In the case of LFA-1, a reincrease of expression levels is seen in newborn mice. The role of these adhesion molecules in T cell development was investigated by adding monoclonal antibodies (mAb) into the FT organ cultures, where T cell development from FT or FL progenitors was induced by coculturing these cells with a deoxyguanosine-treated FT lobe. We found that anti-Pgp-1, anti-LFA-1, and anti-VLA-4 mAb severely inhibited the early phase of T cell development from FL progenitors. On the other hand, the suppressive effect of these mAb on the T cell development from FT progenitors was only slight, if any. These findings strongly suggest that interactions with elements in the thymic microenvironment through Pgp-1, LFA-1, and VLA-4 are indispensable for prethymic progenitors to develop into T cells.

Animals↗
PubMed1996

Small carcinomas of the thyroid. A long-term follow-up of 867 patients.

OBJECTIVE: To determine the adequate extent of surgery for small carcinomas of the thyroid. DESIGN: Retrospective cohort study of 867 consecutive patients with small carcinomas of the thyroid (lesions < 10 mm in diameter) who were operated on at the Noguchi Thyroid Clinic, Oita, Japan, between 1965 and 1987. Mean follow-up was 12.8 years. SETTINGS: A center for treatment of thyroid disease, where about 1400 thyroid operations are performed per year. PATIENTS: Thyroidectomy was performed in patients with a preoperative diagnosis of Graves' disease, Graves' disease with nodules, solitary thyroid nodules, multinodular goiters, cysts, chronic thyroiditis and small carcinomas of the thyroid, in 394, 22, 136, 193, 18, 28, and 76 patients, respectively. RESULTS: Operations were conservative. Three patients who had adenomatous nodular goiters underwent total thyroidectomy. Modified radical neck dissection was performed in 66 patients. Of these 66 patients, 30 had grossly noticeable nodal metastases and 17 had microscopic metastases. Another 50 patients underwent selective lymph node excision, and 28 patients had nodal metastases. Recurrence from remnants of thyroid was seen in five patients. They were treated by surgery. Recurrence in lymph nodes was observed in five patients, and four of them were successfully treated. Recurrence in bone was observed in two patients; one with recurrence in the femur was successfully treated. Two patients died with recurrent cancer. CONCLUSIONS: Small carcinomas of the thyroid can be fatal. Total thyroidectomy is unnecessary. Modified radical neck dissection is unnecessary unless gross nodal metastases are present. Long-term follow-up is mandatory. A

Adolescent↗
PubMed1996

Matrix metalloproteinase-9 secretion by human pituitary adenomas detected by cell immunoblot analysis.

Twenty-two pituitary adenomas were examined on the secretion of matrix metalloproteinase-9 (MMP-9) and tissue inhibitor of metalloproteinase-1 (TIMP-1) using a cell immunoblot assay, and discussed regarding an association between cavernous sinus invasion and the secretion of these proteins. The cell immunoblot assay, a kind of immunoblot procedure, is able to detect proteins at the single cell level and to detect the incidence of tumour cells secreting the target proteins in the total tumour cell population. The incidence of tumour cells secreting MMP-9 was significantly higher in invasive adenomas than in noninvasive ones. On the other hand, TIMP-1 secretion was not detected in any adenomas in this study. This result suggested that MMP-9 secretion, and especially the number of MMP-9-secreting cells, may be associated with cavernous sinus invasion of pituitary adenomas.

Adenoma↗
PubMed1996

Type IV collagenase activity and cavernous sinus invasion in human pituitary adenomas.

Pituitary adenomas are regarded generally as benign tumours, but some of them can invade the cavernous sinus. On the other hand, matrix metalloproteinase-9 (MMP-9), which is a type IV collagenase, recently has been found to be expressed in matastases and to be related to the invasiveness of various malignant tumours including brain tumours. In order to investigate some characteristic features of pituitary adenomas which invade the cavernous sinus, we examined immunohistological studies for MMP-9 in seven pituitary adenomas for type IV collagen in a dura mater and assayed for type IV collagenase activity in seven adenomas using type IV collagen labelled with fluorescein isothiocyaniate (FITC). We found immunopositive adenoma cells for MMP-9 in all invasive adenoma and immunopositive spindle like cells for type IV collagen in the dura mater. All three invasive adenomas had high levels of type IV collagenase activity (0.57-0.72 U/ml), but the four adenomas which did not invade the cavernous sinus had low levels of type IV collagenase activity (0.0-0.10 U/ml). These results suggest that the level of type IV collagenase activity in a pituitary adenoma may be related to its ability to invade the cavernous sinus.

Adenoma↗
PubMed1996

Stoichiometric studies of tannin-protein co-precipitation.

Co-precipitation of a series of galloylglucoses (hydrolysable tannins) with bovine serum albumin (BSA) was studied stoichiometrically by analysing both galloylglucoses and BSA in the precipitates using HPLC. BSA-precipitating ability increased mainly with an increase in the number of galloyl groups in a galloylglucose molecule but was also affected by the position of the galloyl group (penta- > tetra- > 2,3,6-tri- > 2,3,4-tri- >> di- >> monogalloylglucose). The precipitated BSA increased linearly with an increase in the number of galloyl groups bound to a BSA molecule. BSA-precipitating abilities of the galloylglucoses were closely related to their relative affinities for BSA. These results suggest a two-stage mechanism: initial complexation of galloylglucose with BSA and subsequent precipitation, as a mechanism of the co-precipitation.

Animals↗
PubMed1996

Detection and sequencing of Norwalk-like viruses from stool samples in Japan using reverse transcription-polymerase chain reaction amplification.

Norwalk-like viruses were detected in Japan in 12% (26/209) of patients with nonbacteria and nonrotavirus gastroenteritis in an outpatient clinic of a hospital from 1991 to 1994 by reverse transcription-polymerase chain reaction. They were also present in 7% (26/378) of total samples including those from rotavirus-positive gastroenteritis patients. In addition, the viruses were recovered in samples from 15 of 17 patients which were collected during outbreaks of gastroenteritis in various places in Japan by the same method. The DNA sequence of the polymerase region from patients at the hospital (sporadic cases) showed that two subgenogroups, similar to UK1-6 in genogroup G1 and to UK1-1 in genogroup G2 (Ando et al, J Clin Microbiol, 1995, 33: 64-71) exist in Japan. The latter was more frequently found.

Base Sequence↗
PubMed1996

Effect of surgery on gonadal function of premenopausal women with pituitary adenomas other than prolactinomas.

The effects of surgery on pituitary-gonadal function were investigated in women with pituitary adenomas other than prolactinomas. The subjects were 46 women of premenopausal age with a pituitary adenoma. Twenty tumors were GH producing, 19 were nonfunctioning, and 7 were adrenocorticotropin producing adenomas. The surgery was performed mainly via the transsphenoidal route, with the aim of eradicating the tumor and preserving pituitary function. The menstrual cycle was preserved postoperatively in 9 out of 10 (90%) patients with regular preoperative menstruation. Menstrual disturbance was seen in 36 (78.3%) cases preoperatively. The causative factors for menstrual disturbance were gonadotropin impairment and hyperprolactinemia in GH producing and nonfunctioning adenoma. Excessive hormonal secretion itself is a major causative factor for menstrual disturbance in GH and ACTH producing adenoma. Regular menstruation was restored following surgery in 20 out of 36 (55.6%) patients with menstrual problems. The predicting factors for postoperative recovery of menstruation are: size of adenoma less than 40 mm, period of amenorrhea less than 5 years, and preoperatively preserved gonadotropin secretion. In addition, preoperative hyperprolactinemia was also a predicting factor in women with nonfunctioning adenoma. Thus, even in patients with pituitary adenomas other than prolactinoma, the restoration of menstruation is highly achievable when surgery is performed with attention to preserving pituitary function.

Adenoma↗
PubMed1996

Effects of surgery on testosterone secretion in male patients with pituitary adenomas.

The purpose of this study was to assess the effect of surgery on gonadal function in 42 male patients with pituitary adenomas Gonadal functions were evaluated by measuring total serum testosterone concentrations pre- and postoperatively. The subjects of the study were 20 patients with GH secreting adenoma, 7 patients with prolactinoma and 15 patients with nonfunctioning (NF) adenoma. Their ages ranged from 18 to 60 years (mean +/- SEM, 41 +/- 1.9). The serum testosterone concentration was low at less than 300 ng/dl preoperatively in 14 of 20 patients (70%) with GH producing adenoma, 6 of 7 patients (86%) with prolactinoma, and 7 of 15 patients (47%) with NF adenoma. Postoperatively, the total serum testosterone concentration was normalized in 9 of 14 patients (64%) with GH producing adenoma, one of 6 patients (17%) with prolactinoma, and 5 of 7 patients (71%) with NF adenoma. The normalization of serum GH and prolactin concentrations is indispensable for the restoration of gonadal function. It is very important to preserve the normal preoperative gonadotropin secretion by means of gentle surgery.

Adenoma↗
PubMed1996

[The influence of endoscopic injection sclerotherapy (EIS) on respiro-circulatory condition in patients with portal hypertension--the effect of oxygen administration].

We studied the influence of EIS on the respiro-circulatory condition of patients with portal hypertension. Subjects were fifty patients with portal hypertension who were successfully injected more than 5.0 ml of sclerotant into varices. A prospective randomized controlled trial was proposed to elucidate the effect of prophylactic administration of pure oxygen. Twenty-five patients inhaled pure oxygen (O2), remaining twenty-five patients did not during EIS. Respiro-circulatory function of patients was evaluated by monitoring O2 saturation, pulse rate and blood pressure during EIS. PaO2 was measured before and after EIS in seven patients without O2. EIS by the 5% ethanolamine oleate with iopamidol (EOI) was performed under X-ray monitoring. O2 saturation in patients without O2 inhalation was lowered, whereas that in patients with O2 inhalation was stable during EIS. O2 saturation during injection of EOI and after EIS in patients without O2 inhalation was significantly lower than that in patients with O2 inhalation. Pulse rate was significantly lower and a rise in blood pressure was smaller in patients given O2. No significant differences of PaO2 was noted before and after EIS. In conclusion, the monitoring of O2 saturation, pulse rate and blood pressure is necessary during EIS. Prophylactic administration of pure oxygen may be useful for prevention of hypoxic state and respiro-circulatory stabilization during EIS.

Adult↗
PubMed1996

[Effectiveness of PEF monitoring in chronic management of asthma patients].

Whether PEF monitoring introduced by the guidelines (NIH/WHO, International Consensus Report and Japanese Allagology Society Report) is effective or not was discussed in chronic management of patients with asthma. It was stressed to improve usefullness of PEF monitoring in the management of asthma patients that the full understanding of physiological basis of PEF as a lung function test and an augmentation of sensitivity and compliance of the PEF monitoring which includes an improvement of accuracy of devices, and automatic registration of recordings and systems to check the maneuvers of patients to perform PEF is necessary and important.

Animals↗
PubMed1995

Large molecule fraction of plasma separated with polyethylene glycol in treatment of chronic relapsing thrombotic thrombocytopenic purpura.

Plasma exchange and plasma infusion are effective in the treatment of patients with thrombotic thrombocytopenic purpura (TTP). It has been proposed that some component in normal plasma may be deficient in TTP patients. In this experiment normal plasma was fractionated and an effective fraction for the treatment of TTP was sought. Plasma was fractionated with 5% polyethylene glycol and a large molecule fraction was obtained which was composed mainly of proteins and lipoproteins with molecules larger than that of IgG. The fraction was dissolved in physiological saline and infused in two patients with chronic relapsing TTP who had been successfully treated periodically with plasma infusion. Peripheral platelet counts and serum LDH levels were measured, and the efficacy of the treatment was assessed. Infusion of the large molecule fraction elevated platelet counts and lowered the LDH level. However, the efficacy of the large molecule fraction was 25 to 50% that of plasma. Components in the fraction may have been inactivated partially during preparation. We propose that the large molecule fraction contains factors which are effective in some patients with TTP.

Adolescent↗
PubMed1995

Analysis of the growth rate and cavernous sinus invasion of pituitary adenomas.

Pituitary adenomas generally are regarded as benign tumours, but a part of them can invade the cavernous sinus and recur. We examined 43 pituitary adenomas for the following factors: tumour volume, endocrinological function, cavernous sinus invasion, and growth rates examined by using anti-proliferating cell nuclear antigen (PCNA) and MIB1 (a novel anti-Ki-67) as markers. There was significant correlation between PCNA- and MIB1-positive cell rates and PCNA- and MIB1-positive cell rates were higher in the three cases with rapid regrowth than in the other cases. Staining was stronger and more distinct for MIB1 than for anti-PCNA; thus, MIB1-positive cells were easily distinguished by their intense immunoreactivity. MIB1 may be useful for detecting those rare cases with rapid regrowth even when initially regarded as benign tumours. Adenomas with cavernous sinus invasion were significantly larger than those demonstrating no invasion. However, no significant difference was found in the frequency of PCNA- or MIB1-positive cells between adenomas with and without cavernous sinus invasion. These findings suggest that cavernous sinus invasion and growth rate are independent biological factors. Therefore, cavernous sinus invasion may be due to chemical factors produced by the tumour itself rather than as a result of rapid tumour growth.

Adenoma↗