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Biomedical subjects

T Nishi

Publications and source records attributed to T Nishi.

At least 253 records · Page 14Linked to original sources
PubMed1989

High level expression of a synthetic gene coding for IgG-binding domain B of Staphylococcal protein A.

A gene coding for one of the IgG-binding domains of Staphylococcal protein A, designated domain B, was chemically synthesized. This gene was tandemly repeated to give dimeric and tetrameric domain B genes by the use of two restriction enzymes which gave blunt ends. The genes were highly expressed in Escherichia coli to afford a large amount of dimeric and tetrameric domain B proteins. The single domain B protein was efficiently produced as a fusion protein with a salmon growth hormone fragment. The fusion protein was converted to monomeric domain B by cyanogen bromide cleavage. The CD spectra of the monomeric, dimeric and tetrameric domain B proteins were essentially the same as that of native form protein A, showing that their secondary structures were very similar. The dimeric and tetrameric domain B proteins formed precipitates with IgG as protein A. This system permits the efficient production of mutated single and multiple IgG-binding domains which can be used to study structural changes and protein A-immunoglobulin interactions.

Amino Acid Sequence↗
PubMed1989

Estrogen feedback in normal and sulpiride-induced hyperprolactinemic postmenopausal women.

Feedback effect of estrogen on gonadotropin secretion was studied in normal and sulpiride-induced hyperprolactinemic postmenopausal women. Twelve normoprolactinemic postmenopausal women were administered 40 micrograms/day of ethinyl estradiol (EE2) orally throughout the study. On the 4th week of the study, daily doses of 200 micrograms EE2 were also given to each subject for 4 days. Twelve postmenopausal women were given sulpiride orally in a daily dose of 150 mg throughout the study. Serum levels of prolactin were raised in all 12 subjects given sulpiride. In the 12 sulpiride-induced hyperprolactinemic postmenopausal women, EE2 was given in the same manner as in normal postmenopausal women. The negative feedback effect of estrogen with low doses of EE2 (40 micrograms/day for 4 weeks) and the positive feedback effect of estrogen after the subsequent administration of EE2 (200 micrograms/day for 4 days) were demonstrated in both normoprolactinemic and hyperprolactinemic groups. The result of the present study suggests that sulpiride-induced hyperprolactinemia does not affect the negative and positive feedback effect of estrogen in postmenopausal women.

Aged↗
PubMed1989

Asymmetric synthesis of 2-substituted-3-aminocarbonyl propionic acid.

An asymmetric synthetic route to 2-substituted-3-aminocarbonyl propionic acid, which is the significant component of low-molecular-weight renin inhibitors, is described. The key step of this synthesis is diastereoselective alkylation by using chiral oxazolidinone and benzyl bromoacetate.

Chemical Phenomena↗
PubMed1989

Functioning parathyroid lipoadenoma--report of four cases: clinicopathological and ultrasonographic features.

Functioning parathyroid lipoadenoma (hamartoma) composed of abundant adipose or myxomatous stroma and epithelial cell nests is an unusual cause of primary hyperparathyroidism. We report herein four new cases. None of them belongs in the category of multiple endocrine neoplasia or familial hyperparathyroidism. The clinical manifestations and the laboratory findings are indistinguishable from those of the usual forms of primary hyperparathyroidism. Ultrasonography of the neck demonstrated an enlarged parathyroid gland as a hyperechoic mass in the two patients tested. At operation in each case, a single enlarged gland was found and resected, the weight being 3, 0.3, 0.45 and 1 g, respectively. The patients are normocalcemic 1 to 10 years after surgery. Pathological examination disclosed that the lesions were consistent with lipoadenoma or its variants. On reviewing 20 cases of functioning lipoadenoma which were reported in the literature, including the present cases, we found that the size of the tumors varied and a functioning lipoadenoma is hence by no means unusually large as previously reported. Without knowledge of this specific clinicopathologic entity, the lesion may be overlooked at the preoperative localization study and misdiagnosed as a normal or hyperplastic parathyroid.

Calcium↗
PubMed1989

Evaluation of thyroid scintigraphy in small animals.

Thyroid scintigraphy in rats and mice with 99mTc and 123I was attempted to examine whether this modality might be used in small animals and to describe the possibilities of its application in examining experimentally produced thyroid diseases. A human gamma camera with a pinhole collimator improved for small animals was used for imaging. Thyroid images with 99mTc were obtained 20 minutes after injection and those with 123I were 24 hours after administration. All the scintigrams, although those obtained from mice with 99mTc displayed overlapped salivary gland images, demonstrated sufficiently clear images in size and shape, which showed that thyroid scintigraphy in small animals should be applicable in examining experimentally produced thyroid diseases.

Animals↗
PubMed1989

Progesterone feedback in normal and sulpiride-induced hyperprolactinemic postmenopausal women.

The feedback effect of progesterone on pituitary gonadotropin release was investigated in ten normal and ten sulpiride-induced hyperprolactinemic postmenopausal women. Forty micrograms of ethinyl estradiol (E2) was administered orally throughout the study. After E2 pre-treatment, 25 mg of progesterone was administered intramuscularly and serum concentrations of LH and FSH were assayed at 4, 8, 12, 24, and 48 hours after injection. A positive feedback effect of progesterone on gonadotropin release was demonstrated in five normoprolactinemic postmenopausal women and in six sulpiride-induced hyperprolactinemic women. These results suggest that the positive feedback effect of progesterone is maintained in sulpiride-induced hyperprolactinemic postmenopausal women as well as in normoprolactinemic postmenopausal women.

Aged↗
PubMed1989

[Experimental study on tooth fractures in young rats].

The influence of tooth fractures on growth of rat incisors was examined with soft X-ray radiography, xeroradiography and microradiography. Thirty young rats were used in this study and experimental fractures were produced on the mandibular left incisors. Radiological observations were carried out immediately, 7, 14, 21, 28 and 35 days after fracturing. The soft X-ray radiograms obtained immediately after fracturing showed clear radiolucent images. The radiopacity of the fractured regions gradually increased from the 7th day. Enamel hypoplasia was observed from the 7th day, and it moved towards the edge of the incisors with the growth of the fractured teeth. The xeroradiograms obtained at each term demonstrated as same findings as those obtained with soft X-ray radiography. The microradiograms obtained immediately after fracturing showed no noteworthy findings except for the clear radiolucent area of the fractured regions. Fine radiopaque lines along the edges of fractured regions were observed from the 7th day. Dentin-like radiopaque calcified masses were observed from the 14th day.

Animals↗
PubMed1989

[Clinical significance of measurement of nuclear DNA content in breast cancer].

Nuclear DNA content measured by a cytofluorometric method was investigated to evaluate its clinical significance in 73 cases with breast cancer which had extended radical mastectomy. Many cases of D type (diploid type) which had a prominent peak at the 2c region (control DNA content of lymphocytes) were safe indications for modified radical mastectomy. Bone recurrence was significantly more frequent in D type than in N type (non-diploid type) which did not have a prominent peak at the 2c region. Because D type had high positive rate of hormone receptors, endocrine therapy might be effective for many cases. Local or lung recurrence was more common in cases with N type which had a significant low cumulative survival rate compared with D type and especially N type 4c-3 of which over 4c cells more than 30% had the poorest prognosis. Therefore, multidisciplinary treatment composed of extended operation, radiation and chemotherapy was necessary to improve the prognosis of breast cancer patients with N type 4c-3. It was concluded that the measurement of nuclear DNA content in breast cancer might be useful for decision of therapy suitable for each case based on malignancy grading.

Breast Neoplasms↗
PubMed1988

Constitutional and echocardiographic variability of the normal electrocardiogram in children.

To understand better the normal electrocardiogram and to improve the diagnosis of left ventricular hypertrophy (LVH), the authors examined RV5 and SV1 + RV5, using a special computational technique, in relation to body size, heart size, and the distance between the heart and the chest wall in 7-year-old normal subjects. Boys and girls were analyzed separately. Using multiple regression analysis with a total of 16 constitutional and echocardiographic parameters as the predictor variable, the authors selected a minimum set of parameters and found that the greater the left ventricular mass (LVM) and the left ventricular cavity and the shorter the distance between the heart and the chest wall, the greater the RV5 and SV1 + RV5. In subjects with LVH in whom these parameters vary, SV1 + RV5 is preferable to RV5 for the electrocardiographic diagnosis of LVH, because LVM correlates more significantly with SV1 + RV5. In a similar analysis, using principal components as the predictor variable, no significance level was reached for the first principal component that represented size. This indicates that RV5 and SV1 + RV5 are in a constant range, irrespective of the body size and accompanying heart size.

Body Constitution↗
PubMed1988

Pituitary and testicular response to luteinizing hormone releasing hormone in normal and sulpiride-induced hyperprolactinaemic men.

Pituitary and testicular response to an intravenous infusion of 480 micrograms luteinizing hormone releasing hormone (LHRH) for 8 hours (1 microgram/min) was investigated in 8 male volunteers in normal and hyperprolactinaemic state. Eight normal men were given 150 mg of sulpiride daily for 14 days. Serum prolactin (PRL) levels were elevated significantly, but basal serum levels of luteinizing hormone (LH) and follicle-stimulating hormone (FSH) did not change following daily oral administration of sulpiride in 8 normal men. Eight men showed biphasic LH response to LHRH infusion in both normal and hyperprolactinaemic state, and there was a rather exaggerated response in serum LH concentration in hyperprolactinaemic state. Serum FSH response to LHRH was similar in normal and hyperprolactinaemic state. Although slight increase in serum testosterone concentration was observed during LHRH infusion in normal and hyperprolactinaemic state, the statistical difference was not significant. The result of the present study suggests that the function of the hypothalamic-pituitary-testicular axis, as measured by serum gonadotrophin and testosterone responses, is well reserved.

Adult↗
PubMed1988

Experimental chronic pulmonary infection in mice caused by Klebsiella pneumoniae.

Examination of mouse strain differences in susceptibility to experimental respiratory tract infection with Klebsiella pneumoniae 27 revealed that a chronic pulmonary infection model could be established using CBA/J mice. After 6 X 10(5) colony-forming units of K. pneumoniae 27 were inoculated into the lung, the bacterial counts in the lungs changed with time showing four different phases: initial decrease, regrowth, steady-state, and final increase leading to death. Throughout the course of the infection, the challenge bacteria were isolated mainly from the respiratory organs. Pulmonary gross lesions appeared on day 2 after infection and persisted thereafter. Lobar consolidation was the primary lesion and occurred mainly in the anterior and middle lobes of the right lung, and the median lobe. Mice began to die from 4 weeks after aerosol exposure. This model may be useful for investigating the pathogenesis of chronic pulmonary infection by Klebsiella and its therapy.

Animals↗
PubMed1988

Effect of recombinant human interleukin-2 on the course of experimental chronic respiratory tract infection caused by Klebsiella pneumoniae in mice.

The effect of recombinant human interleukin-2 (rIL-2) on the course of experimental chronic respiratory tract infection caused by Klebsiella pneumoniae in mice was examined. rIL-2 was administered subcutaneously once a day for 7 or 14 days, starting 2 weeks after the mice were infected. Administration of 2 or 20 micrograms of rIL-2 per mouse daily for 7 days reduced bacterial counts in the lungs dose dependently. At a dose of 0.2 microgram per day, proliferation of bacteria in the lungs was suppressed after 14 days of administration. Agglutinin titers in serum were not affected by rIL-2 treatment. Monocyte and lymphocyte counts in peripheral blood were increased by administration of 20 micrograms of rIL-2 daily for 14 days but not by treatment for 7 days. In addition, clearance of bacteria from the lungs after aerosol exposure was enhanced by treatment for 7 days before infection. Thus, rIL-2 acted therapeutically or prophylactically in the presence or absence, respectively, of a specific antigen. These effects were not abolished by anti-asialo GM1 antibody. This suggests that activation of natural killer cells does not play a critical role in the therapeutic and prophylactic effects of rIL-2.

Aerosols↗
PubMed1988

Contribution of hepatic reticuloendothelial system to glomerular IgA deposition in rat liver injury.

Liver damage was induced in rats by a single dose of dimethylnitrosamine or D-galactosamine. In the dimethylnitrosamine model, marked glomerular IgA deposition occurred between Days 4 and 28, with its peak at Day 14. Serum IgA levels were significantly increased at Days 2 and 4, then gradually decreased, and normalized at Day 14. In the D-galactosamine model, however, no such deposition was observed, though serum IgA levels similarly increased on Days 2 and 4. IgA content in high molecular weight fraction from serum increased at Day 3 in both models. This increment remained at Day 7 only in the dimethylnitrosamine model, in which carbon clearance from the circulation was significantly decreased at Day 3. These data suggest that dysfunction of the hepatic reticuloendothelial system is a factor contributing to glomerular IgA deposition occurring in liver injury.

Alanine Transaminase↗
PubMed1988

[Malignancy grading in breast cancer as assessed by nuclear DNA content].

The relationship between nuclear DNA content measured by cytofluorometry and the prognostic factors, especially the histological lymph node metastasis was investigated in patients with breast cancer. Nuclear DNA content was measured in 82 cases to evaluate its clinical significance concerning the malignancy grading. Histograms of DNA content were classified into two basic ploidy patterns based on presence or absence of a prominent peak at the 2c (diploid) region. D type (diploid type) which had a prominent peak at the 2c region resembled the histogram pattern of normal cells more closely than N type (non-diploid type). The rate of lymph node metastasis of N type (57.4%) was significantly higher than that of D type (28.6%) (p less than 0.05). The rate of lymph node metastasis of N type was higher than D type regardless of the tumor size or histological types. The five year cumulative survival rate of D type (91.7%) was significantly higher than that of N type (68.2%) (p less than 0.05). Despite the lymph node metastasis, the survival rate of D type was higher than that of N type. From a view point of the relationship between nuclear DNA content and lymph node metastasis, breast cancers of D type might be much safer indications for modified radical mastectomy. From this study, it was suggested that the measurement of nuclear DNA content of the breast cancer would bring the important informations about the malignancy grading and decision of the operative procedure.

Adult↗