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Biomedical subjects

K Nakada

Publications and source records attributed to K Nakada.

At least 145 records · Page 8Linked to original sources
PubMed1992

Effect of serotonin on the immunoreactive thyrotropin-releasing hormone concentrations of the rat stomach.

The effects of serotonin and its related compounds on immunoreactive thyrotropin-releasing hormone (ir-TRH) concentrations of the rat stomach wall and gastric juice were studied. Either serotonin, cyproheptadine or GR38032F was injected intraperitoneally, and the rats were decapitated at various times after the injection. ir-TRH concentrations of the stomach wall and gastric juice were measured by radioimmunoassay, and gastric serotonin concentrations were measured by HPLC. ir-TRH concentrations of the stomach wall decreased, and ir-TRH concentrations of gastric juice increased significantly after serotonin injection. On the other hand, both cyproheptadine and GR38032F did not affect ir-TRH concentrations of the stomach. The effects of serotonin on ir-TRH concentrations of the stomach were significantly blocked by the pretreatment of cyproheptadine and GR38032F. The reciprocal changes of gastric ir-TRH and serotonin concentrations were observed without changes in gastric juice pH. These findings suggest that serotonin stimulates ir-TRH release from the stomach wall into gastric juice, and the effects of serotonin on ir-TRH release may be partly mediated via 5-HT2- and 5-HT3-receptors.

Animals↗
PubMed1992

Radioimmunoassay for the determination of 2-methoxyestriol concentration in plasma of pregnant women.

A specific assay method has been developed for the determination of 2-methoxyestriol in plasma of pregnant women. The quantitation was achieved by radioimmunoassay after extraction of the plasma with ethyl acetate and purification on a Sephadex LH-20 column. In order to obtain the immunogen for 2-methoxyestriol, 6-oxo-2-methoxyestriol was converted to its 6-(O-carboxymethyl)oxime derivative. The derivative was then coupled to bovine serum albumin by the mixed anhydride method, and rabbits were immunized with this conjugate. The antiserum obtained was partially purified by affinity chromatography on estrone 17-(O-carboxymethyl)oxime-aminohexyl Sepharose conjugate to eliminate the cross-reactive antibodies. Plasma 2-methoxyestriol concentrations in pregnancy were estimated to be mean values of 41.1 pg/ml (12th-14th week), 85.3 pg/ml (27th-29th week), and 97.5 pg/ml (37th-41st week).

Cross Reactions↗
PubMed1992

[Effects of a non-ionic low osmolar contrast medium on thyroidal radioiodine uptake in rats].

Recently non ionic low osmolar contrast media (NILOCM) have been widely used in radiographic contrast studies. These new agents have a great advantage over conventional ionic high osmolar contrast media (IHOCM) in low chemical toxicity and good X-ray absorption. However, their effects on thyroid function, especially on thyroidal radioiodine uptake (TRIU), are still unknown and it is not clear how long NILOCM interfere with TRIU. Therefore, the extent of the interference with TRIU caused by previous NILOCM injection was examined using rat thyroid. Male WKA rats were divided into four groups and fed under different dietary conditions, A) routine diet for rats; B) low iodine diet (LID) for 1 week, C) LID for 2 weeks, and D) LID for 8 weeks. Iopamidol was used as NILOCM, and iothalmate, one of IHOCM, was also employed for comparative study. After feeding, some rats in each group were injected with 300 mgI/kg. b.w. of iopamidol or iothalmate. The remaining rats in each group received saline injection as the control. At day 1, 2, 3, 7, and 14 following injection, I-131 was administered intravenously and a 24 hour TRIU (% dose/mg tissue) was measured in each group. Thyroidal iodine content (TIC: micrograms I/mg tissue) at day 1, 7, and 14 was also measured in group A, C, and D. Until day 3, severe suppression on TRIU was observed in all groups, and TIC elevated at day 1 in iothalmate-injected rats. In iopamidol-injected rats, TRIU and TIC recovered after then, and reached the same levels as those in control rats until day 14 except for group D. However, TRIU was still significantly lower and TIC levels in group D was higher at day 14 in iothalmate-injected rats. It is concluded that iopamidol has less effects on TRIU and TIC with a shorter period of recovery than iothalmate. This results maybe beneficial to the patients who were injected NILOCM prior to radioiodine scintigraphy.

Animals↗
PubMed1991

Effects of water-immersion-induced stress and intraperitoneal administration of brain-gut peptides upon immunoreactive thyrotropin-releasing hormone and prostaglandin E2 concentrations in the rat stomach.

The effects of water-immersion-induced stress and intraperitoneal (i.p.) administration of selected neuropeptides on the levels of thyrotropin-releasing hormone (TRH) and prostaglandin E2 (PGE2) were studied in the rat stomach. Water-immersion caused a significant decrease immunoreactive-TRH (ir-TRH) concentrations in the stomach, and a significant increase in ir-TRH concentrations in the gastric juice. The concentrations of PGE2 were significantly increased at 0.5-4 hrs, and significantly decreased at 6-8 hrs after water-immersion. In the experiment of i.p. administration of selected neuropeptides, the level of ir-TRH in the stomach was significantly decreased after VIP injection, whereas it was significantly increased after beta-endorphin injection. The concentration of PGE2 was significantly decreased in the stomach after i.p. administration of TRH and VIP. However, it did not change after beta-endorphin injection. These results indicate that some neuropeptides may participate in regulating the endogenous level of PGE2 and that these interrelations between neuropeptides and PGE2 may be important as ulcerogenic factors in stress ulcers induced by water-immersion in the rat.

Animals↗
PubMed1991

Single photon emission computed tomography with Tc-99m-dimercaptosuccinic acid in patients with upper urinary tract infection and/or vesicoureteral reflux.

By means of Tc-99m dimercaptosuccinic acid (DMSA) scintigraphy, an established method for assessing renal cortical damage, we evaluated the pick-up rate for renal defects (scars) by single photon computed tomography (SPECT) and planar images of 10 normal volunteers, and 58 patients (70 scintigrams) with upper urinary tract infections, most of whom had a history of vesicoureteral reflux (VUR). The positive study rate for renal defects depended on the severity of VUR. The overall positive rates for renal cortical defects obtained by DMSA SPECT imaging and DMSA planar imaging were 60% and 43%, respectively, and the difference between these was significant (p less than 0.005). The mean absolute individual renal uptake (/injected dose) at 2 hours post-injection was decreased in kidneys with defects detected by SPECT alone. The positive study rate for intravenous urography (IVU) depended on the grade of VUR and was 15% overall. DMSA SPECT imaging detects renal cortical defects at greater frequency than previously achieved.

Adolescent↗
PubMed1991

[Gallbladder function and CCK after gastrectomy].

Postgastrectomy cholelithiasis has become a problem and biliary tract dyskinesia has been cited as an etiologic factor. CCK is the most important gut hormone with respect to biliary tract function, so we conducted an experimental study of postgastrectomy gallbladder function and CCK levels which gave the following results: 1. Although postprandial gallbladder contraction for the most part occurred in response to endogenous CCK, another mechanism (the gastro-cholecystic reflex) seemed to be responsible for some of them. 2. The postgastrectomy decrease in postprandial gallbladder contraction appeared to be due to disappearance of this gastro-cholecystic reflex. 3. Gallbladder contraction occurred in association with postprandial CCK secretion following total gastrectomy and Roux-en-Y reconstruction, but the altered food passage route caused changes in the dynamics of CCK secretion, and this is believed to have had an influence on the gallbladder contractile response.

Animals↗
PubMed1990

[Cystic papillary carcinoma of the thyroid--sonographic-pathologic correlation].

Ultrasonographic findings of 13 patients with cystic papillary carcinoma (CPC) of the thyroid gland were reviewed retrospectively correlating with pathologic findings. A 4-6 cm oval cystic structure with a 2-3 cm pedunculated projection of mass into the lumen was the characteristic sonographic findings of CPC. However, other sonographic findings of CPC simulated adenoma, nodular goiter or follicular carcinoma. Pathological investigation revealed that malignant cells tended more to be located in intracystic pedunculated mass and/or pericystic region than in the cyst wall. In most of the cases cyst walls were chiefly composed of granulomatous tissue with scattered malignant cells. These findings indicate that the needle biopsy should be done under ultrasonographic guidance to obtain sufficient material for accurate cytologic and/or pathologic diagnosis, thereby reducing the number of false negative cases.

Adult↗
PubMed1990

The clinical features and prognosis of rhabdomyosarcoma: follow-up studies on pediatric tumors from the Japanese Pediatric Tumor Registry 1971-1980. Part II. Committee of Malignant Tumors, Japanese Society of Pediatric Surgeons.

A retrospective study was conducted on 126 patients with rhabdomyosarcoma enrolled in the Japanese Pediatric Tumor Registry between 1971 and 1980. The age of the patients ranged from less than 1 year to 15 years, and the male to female ratio was 1.3:1.0. Primary sites included the pelvis (37.3 per cent), abdomen (23.8 per cent), head and neck (21.4 per cent), thorax (9.5 per cent), extremities (6.4 per cent) and unknown (1.6 per cent). According to the staging system of the Japanese Society of Pediatric Surgeons, the extent of disease was classified into stages Ia (26.2 per cent of the total); Ib (14.6 per cent); II (12.6 per cent), III (29.1 per cent) and IV (17.5 per cent). The clinical stage was significantly correlated with survival outcome in this series (p less than 0.05). Age, sex, histology and primary site per se had no independent prognostic influence on tumor-free survival. With regard to treatment modalities, surgery was performed in 94.0 per cent of the patients, and radiotherapy at a mean dose of 37 Gy, and/or multi-agent chemotherapy in 41.7 per cent and 80.0 per cent, respectively. The patients who underwent total excision had a better survival outcome than those who did not (p less than 0.05). Combination chemotherapy such as VAC was more commonly administered in the latter study period. The overall 2-year tumor-free survival rate (2YTFSR) significantly improved from 24.0 per cent in the former period between 1971 and 1975 to 48.7 per cent in the latter period between 1976 and 1980 (p less than 0.05).

Adolescent↗
PubMed1990

The effects of histamine on the concentrations of immunoreactive thyrotropin-releasing hormone in the stomach and hypothalamus in rats.

The effects of histamine and its related compounds on the concentrations of immunoreactive thyrotropin-releasing hormone (ir-TRH) in the stomach, gastric juice and hypothalamus in rats were studied. Histamine, ranitidine or ethanolamine was injected intraperitoneally, and the rats were decapitated at various times after the injection. Ir-TRH concentrations in the stomach, gastric juice and hypothalamus were measured by a radioimmunoassay. Ir-TRH concentrations in the stomach decreased significantly after histamine injection and increased significantly after ranitidine injection in a dose-dependent manner, but did not change with ethanolamine. Ir-TRH concentrations in the gastric juice increased in a dose-dependent manner, peaking at 30 min after histamine injection, and its effect was blocked with ranitidine. Ir-TRH concentrations in the hypothalamus elevated significantly after histamine injection and reduced significantly after ranitidine injection, but did not change with ethanolamine. The effects of histamine on ir-TRH concentrations in the stomach and hypothalamus were significantly blocked with ranitidine, but not with ethanolamine. These findings suggest that histamine stimulates ir-TRH release from the stomach and inhibits ir-TRH release from the hypothalamus, and that these effects of histamine on ir-TRH release are mediated via an H2-receptor.

Animals↗
PubMed1990

Application of monoclonal antibodies to the detection of black-pigmented Bacteroides spp. in subgingival plaques by immunoslot blot assay.

The aim of the present study was to assess the application of monoclonal antibodies to the detection of black-pigmented Bacteroides spp. in subgingival plaques by immunoslot blot assay. Subgingival plaque samples from adult periodontal patients were examined by immunoslot blot assay with monoclonal antibodies that specifically recognize Bacteroides gingivalis, Bacteroides intermedius serogroups I and II, and Bacteroides melaninogenicus. The assay can detect specifically these Bacteroides spp. in the subgingival plaques. Therefore, we investigated the distribution of these Bacteroides spp. in the subgingival plaques of patients classified by Russell's periodontal index. Reactivities of their plaques with monoclonal antibodies toward B. gingivalis and B. intermedius serogroup I were clearly related to the severity of the periodontal disease, but this was not the case with B. intermedius serogroup II and B. melaninogenicus. These results indicate that this immunoslot blot assay using monoclonal antibodies toward these Bacteroides spp. provides simple detection and monitoring of these organisms in periodontal patients.

Adult↗
PubMed1990

[A study of growth prediction of low-birth-weight infants].

To predict the time required for low-birth-weight (LBW) infants to catch-up with standard weight, the growth curves for weight in 156 LBW infants with no medical abnormalities were examined. The proportion of infants who caught-up with standard weight by 1.5 years of age was significantly higher in appropriate-for-dates (AFD) infants than in small-for-dates (SFD) infants (93% vs. 70%). The age of catch-up with standard weight had a significant inverse correlation with birth weight in AFD infants, and not in SFD infants. The age of catch-up standard weight of AFD infants, as predicted by the regression analysis was 4-8 months for 2,000 g of birth weight, 8-12 months for 1,500 g, and 12-15 months for 1,000 g, with about 80% accuracy. This prediction may be valuable in providing health advice to mothers with LBW infants.

Age Factors↗
PubMed1990

[Quantitation of absolute and relative renal uptake using 99mTc-DMSA: sequential change in time and correlation with 99mTc-DTPA uptake].

A renal uptake of 99mTc-DMSA as a function of time and correlation between 99mTc-DMSA and 99mTc-DTPA in renal uptake were discussed. The absolute renal uptake of 99mTc-DMSA calculated by complete correction of tissue attenuation and physical decay showed increase by 5 hours after the administration, except one case with congestive heart failure. The net renal counts attained a maximum between 2 to 3 hours after the administration. There was a good correlation (r -0.992, p less than 0.001) between the relative renal uptake of 99mTc-DMSA (2 hour) and that of 99mTc-DTPA (2-3 min). On the contrary, the absolute renal uptake of 99mTc-DMSA as a indicator of total renal function showed a poor correlation (r = 0.419) to GFR calculated from 99mTc-DTPA. The results indicate that the relative renal uptake of 99mTc-DMSA is a reliable quantitative parameter for split renal function. However, the absolute renal uptake of 99mTc-DMSA may be suggested to be a different renal functioning indicator from GFR calculated from 99mTc-DTPA.

Adolescent↗
PubMed1990

[Captopril-enhanced renography using 99mTc-DTPA in renovascular hypertensive patients].

Dynamic renal scintigraphy with 99mTc-DTPA before (baseline renography: BS-RG) and 1 hour after administration of 25 mg to 50 mg of captopril (captopril-enhanced renography: CP-RG) was performed in a selected series of 18 patients suspected of having renovascular hypertension. Final diagnosis was made by angiography and further clinical follow-up. Eight patients were considered as renovascular hypertension (RVH), 6 with bilateral renal artery stenosis (BRAS) and 2 with unilateral renal artery stenosis (URAS). The remaining 10 patients were non-renovascular (non-RVH). Two criteria were prospectively employed for evaluating positive response induced by captopril. Glomerular filtration rate (GFR) on BS-RG (GFRbase) and on CP-RG (GFRcap) was estimated by early (120-180 seconds) DTPA uptake by the kidney, and then captopril response rate (CRR) was calculated in the following: CRR = (GFRcap-GFRbase)/GFRbase X 100 (%). CP-RG was considered positive when it was less than 20%. Renogram shape was also independently evaluated. CP-RG was also considered positive when either a delay of time to peak activity of more than 5 min or conversion of renogram shape to an obstructive or non-functioning pattern was observed. The sensitivity and specificity of CRR and change in renogram were 50% and 80%, 63% and 100%, respectively. In BRAS, positive response was observed in the unilateral kidney alone which maintained relatively a good renal function. CP-RG could not differentiate RVH with URAS from that with BRAS. Four patients were followed after the surgical or angioplastic treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1989

Tracheal agenesis with bronchoesophageal fistulas--a case report.

Although tracheal agenesis is presently considered to be a rare and fatal anomaly, an increasing number of institutions have been reporting such cases. Reported herein, is a clinical and necropsy report of a premature infant whose tracheal agenesis was associated with broncho-esophageal fistulas and an imperforate anus. Accidental esophageal intubation enabled a perineal anoplasty to be performed under general anesthesia and allowed him to survive for 14 days.

Anus, Imperforate↗
PubMed1989

[Statistical analyses of clinical observations made on outpatients visiting the Department of Oral Diagnosis, Meikai University School of Dentistry Hospital, for the past 16 years].

Statistical analyses of clinical observations made on outpatients visiting the Department of Oral Diagnosis, Meikai University School of Dentistry Hospital from June, 1970, to August 1986 were carried out. The total number of new outpatients during this period was 73,708. The results were as follows: 1) The largest number of patients was found in 1978. 2) There was a tendency for the number of new patients to increase in March, June, and August of every year. The smallest number of patients came in December. 3) The greatest number of new patients visiting the hospital was in the 0-9 age category, followed by those in the 20-29 and 30-39 age categories. 4) The greatest chief complaint of patients visiting the hospital was pain, followed by masticatory disturbance and swelling. 5) The number of outpatients coming to the hospital for cosmetic and temporomandibular joint problems has been increasing on a yearly basis over the past 16 years.

Adult↗