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Biomedical subjects

S Nakata

Publications and source records attributed to S Nakata.

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

Characterization of monoclonal antibodies to human group B rotavirus and their use in an antigen detection enzyme-linked immunosorbent assay.

Three monoclonal antibodies (MAbs)--B5C9, B5E4, and B10G10--to human group B rotavirus, an agent implicated in epidemic outbreaks of diarrhea in the People's Republic of China, primarily in adults, were prepared. MAb reactivity was decreased when virus preparations were treated with EDTA, suggesting reactivity with the outer-capsid protein(s). Competition experiments suggested that these MAbs recognize overlapping epitopes within a single antigenic site. A simple antigen detection enzyme-linked immunosorbent assay (ELISA) specific for the human group B rotavirus was established by using these MAbs as capture antibodies. Fifteen clinical samples obtained from three epidemic areas in the People's Republic of China and previously shown by Chinese scientists to contain group B virus were all positive in the MAb capture antigen detection ELISA, whereas none of the 57 samples lacking the group B virus reacted in the test. The results suggest that this MAb capture antigen detection ELISA will be useful to identify outbreaks caused by the human group B rotavirus and to monitor possible spread of the virus.

Animals↗
PubMed1989

A follow-up study of an uncemented knee replacement. The results of 312 knees using the Kodama-Yamamoto prosthesis.

The Kodama-Yamamoto knee is an uncemented surface replacement which has been used since 1970. The design has been improved twice and this present report concerns the results of the Mark II model. Between 1980 and 1984, 350 knees were replaced in 225 patients. In 1987, a survey of 335 of these knees was conducted at two to seven years after operation. The results were excellent or good in 83% of patients. Many of the failures were because of general disorders unrelated to the operation, but in 5.4% of the knees there were local complications which continue to present problems.

Arthritis, Rheumatoid↗
PubMed1989

[Consideration on the treatment of transposition of the teeth].

The two cases with the transposition of the teeth were treated orthodontically. One was a case in which the teeth which had changed places with each other were aligned in irregular sequence, the other was one with the teeth which had erupted at the unusual position were repositioned in order of the tooth number. Those causes and some problems involved in diagnosis and treatment were discussed. 1. The causes of transposition of the teeth in the two cases reported herein seemed to be premature loss of primary teeth and the malposition of permanent tooth germs, respectively. 2. At the time of the planning of the treatment, the following must be considered. 1) Perfect transposition or imperfect. 2) The positions of root apexes and axial inclinations of the teeth irregularly erupted. 3. Root paralleling is most important for the stability of the treatment results. Moreover, in case of unusual alignment, prevention of premature contact in jaw movement and improvement of appearance must be endeavored.

Humans↗
PubMed1989

[Effects of hypopressure on blood gases and spirograms of patients suffering from chronic respiratory failure].

We examined the effects of hypopressure on blood gases and spirograms of patients suffering from chronic respiratory failure, and compared them with those of normal subjects, using the environmental control unit (ECU). The patients consisted of 2 with idiopathic interstitial pneumonia (IIP), 1 with pulmonary fibrosis due to RA, 3 with bronchiectasis, 2 with chronic bronchitis and 1 with diffuse panbronchiolitis (DPB). We examined their blood gases and spirograms under the condition of 760 mmHg pressure, 25 degrees C temperature and 60% humidity. Then the pressure of ECU decreased to 670 mmHg in 20 minutes, while the temperature and humidity were kept the same. The patients stayed in the hypopressured ECU for 1 hour, and were reexamined. The pressure of 670 mmHg is that of an altitude of about 1,000 m and that of the cabin pressure of commercial aircraft flying at about 9,000 m. The PaO2 of the patients decreased from 74.7 +/- 13.8 torr to 61.8 +/- 9.5 torr significantly. We found, however, the significant decrease of PaO2 in normal subjects from 97.2 +/- 7.8 torr to 80.4 +/- 6.5 torr under the same conditions. The rates of the decreased gases were almost same in both groups. Some patients showed remarkable decreases in VC and FEV1.0 under the hypopressure. No patients or control subject complained of subjective symptoms.

Adult↗
PubMed1989

[Imaging diagnosis of ruptured site in hepatocellular carcinoma].

Rupture causes frequently the patients with HCC to death. Then it is important to investigate ruptured site of HCC in order to stop bleeding effectively and safely by emergent TAE without causing liver failure. We evaluate the usefulness of 3 major imaging method, such as US, CT and angiography in our 18 cases of HCC. In ultrasonography, ruptured site was shown as the high echoic area localized around the tumor in 4/15 cases (26.7%). In computed tomography of rapid scanning, it was shown as the intraperitoneal high density area around the tumor in 3/18 cases (16.7%). And lipiodol CT showed the characteristic leakage in the abdominal cavity. In angiography, it was shown as the extravasation of contrast material only in 2/13 cases (15.4%). In the results, it was possible to diagnose the ruptured site in 8/18 cases (44.4%) by using these procedures. Diagnosis of ruptured site will make it possible to reduce the frequency of hepatic failure caused by emergent TAE.

Adult↗
PubMed1989

End-to-side and end-to-end vascular anastomoses with a carbon dioxide laser.

This study was designed to compare anastomoses performed with a carbon dioxide laser and conventional anastomoses performed with 7-0 polypropylene suture. In each of 80 rabbits, the divided left carotid artery was anastomosed by a continuous suture technique and the right carotid was anastomosed with a carbon dioxide laser. In each of 40 additional rabbits, both end-to-end and end-to-side laser anastomoses were performed on the same carotid artery. The laser technique involved the placement of three stay sutures (end-to-end technique) or four stay sutures (end-to-side technique) of 7-0 polypropylene and an everting laser seal at a power level of 65 mW. The 1-year overall patency rate was 98% (78/80) in laser anastomoses, 79% (63/80) in suture anastomoses, and 95% (38/40) in combined end-to-end and end-to-side laser anastomoses. Microscopic findings in laser anastomoses demonstrated degeneration of collagen and protein in the adventitia and media, but much less intimal injury than in suture anastomoses, with reendothelialization beginning earlier (within 7 days after anastomosis as compared with 2 to 4 weeks). The tissue tensile strength at 1 hour was less in laser anastomoses than in suture anastomoses, but the laser anastomoses still withstood an intraluminal pressure load of 380 mm Hg. Laser anastomosis improved the microscopic and histologic appearance of the intimal layer, allowing for rapid early reendothelialization and resulting in excellent patency rates.

Anastomosis, Surgical↗
PubMed1989

[Clinical study on the endoscopical lithotomy in cholecystolithiasis].

Endoscopical lithotomy was carried out in 14 patients with cholecystolithiasis. 6 patients were men and 8 were women (age 40-78). 4 of them underwent endoscopical lithotomy because of their inoperability. The other patients refused surgical operation and wished the procedure. Percutaneous Transhepatic Cholecystic drainage (PTCCD) was performed at the right intercostal space under ultrasonic guide and was dilated to 16 Fr in diameter. After 1-2 weeks, lithotomy by using Percutaneous Transhepatic Cholecystoscopy (PTCCS) started. Nd-YAG laser and/or Electrohydraulic lithotripter were used to fragment stones. Lithotomy was successfully finished without serious complications in all cases. In conclusions, the therapeutic advantage of PTCCS may be expected for cholecystolithiasis.

Adult↗
PubMed1988

Quantitative genetic analysis of bi-iliac breadth.

Bi-iliac breadth, the frontal maximum diameter between right and left iliac crests, was measured in 1,547 male and 2,085 female residents of a rural area in Japan. All subjects were over 14 years of age. The bi-iliac breadth showed an increase related to age but little sex difference. Modification of age and sex variations from the measured value was obtained by calculation of the score, represented by arithmetical means and standard deviations. Distribution of these scores appeared to be binomial, and since binomial distribution approaches normal distribution when n is large, it is presumed that this trait gains normal distribution. Thus variation of bi-iliac breadth in subjects 20-79 years of age enables us to analyze inheritance. No significant difference was found between husband and wife in the correlation coefficients or between father and daughter (0.13 +/- 0.08). Significant differences were found as follows: father-son (0.35 +/- 0.05) (P less than 0.001), mother-son (0.28 +/- 0.05) (P less than 0.001), and mother-daughter (0.28 +/- 0.06) (P less than 0.001). There was no indication of maternal or paternal effects, since no significant difference was found in father-child and mother-child correlation coefficients. It is concluded that bi-iliac breadth is a quantitative genetic trait under control of polygenes on autosomes. Regression coefficient of child on midparental value was 0.55 +/- 0.05, approximately twice the means of four pairs of correlation coefficients between parent-offspring. Narrowly, heritability was estimated as 0.54 approximately 0.55. Contribution of dominance to total variance was small (VD = 0.11), in contrast to the larger additive genetic variance (VA = 0.54).

Adolescent↗
PubMed1988

The mechanism of discordant xenograft rejection.

The mechanism of discordant xenograft rejection using the guinea pig-to-rat heart graft model was studied. In this model, we found that (A) Rejection occurred rapidly, in 17.5 +/- 8.3 min (mean +/- SD) (n = 8). (B) The graft survived longer when the recipient rat was pretreated with cobra venom facter (CVF). (C) Complement hemolytic titers in serum showed significant reduction of C3 in rejection without consumption of C4 and C2, suggesting complement activation through the alternative pathway. (D) No natural antibodies were detected in this combination. Complement-dependent cytotoxicity (CDC) titer, and hemagglutination (HA) titer were lower than x1. (E) Histological examination of the rejected heart xenograft revealed a large area of myocytolysis without interstitial cellular infiltration. (F) In vitro experiments showed that rat complement attacked guinea pig erythrocytes (Egp) via the alternative pathway. These findings indicate that rejection in this discordant xenograft model of guinea pig-to-rat was caused by primary activation of complement via the alternative pathway.

Animals↗
PubMed1988

Detection of human calicivirus antigen and antibody by enzyme-linked immunosorbent assays.

Enzyme-linked immunosorbent assays (ELISAs) were developed to detect human calicivirus (HCV) antigen and antibody to HCV. The ELISAs were specific for HCV and as sensitive as a previously developed radioimmunoassay. These ELISAs were used to search for evidence of HCV infection in the United States, where HCV gastroenteritis has rarely been reported. One hundred sixty-three stool samples collected from children hospitalized with diarrhea were examined; one sample was positive in the ELISA. Typical calicivirus particles were found in this stool sample, and these particles reacted with a hyperimmune guinea pig anti-HCV serum by immune electron microscopy. The age-related acquisition of antibody to HCV in hospitalized infants and children (from birth to 19 years old) without gastroenteritis and in healthy adults was also evaluated. The pattern of acquisition of antibody to HCV was similar to that for group A rotaviruses, namely, beginning in infancy and becoming 100% by the age of 4 years. These data suggest that HCV is associated with infantile gastroenteritis in the United States, that infections with HCV are common, and that many infections with HCV (Sapporo strain) may not require hospitalization.

Adolescent↗
PubMed1988

[A case of leiomyoma of the spermatic cord].

A 46-year-old man visited our clinic with the chief complaint of indolent swelling of the left scrotal contents. An elastic hard and fist-sized mass with negative transillumination was palpable in left scrotum, but testis and epididymis were not discriminated. Left high orchiectomy was performed. Tumor was 90 X 55 mm in size and the testis and epididymis at the lower pole of the tumor were intact. Histological diagnosis was leiomyoma and we diagnosed leiomyoma of the spermatic cord. To our knowledge, this is the 5th case reported in Japan.

Genital Neoplasms, Male↗
PubMed1988

[Statistical study of penile cancer].

Between 1961 and 1985, 44 cases of penile cancer were experienced at Gunma University Hospital. We statistically analyzed 42 of them. The average age was 56.9 years old, ranging from 28 to 86 years old. Interval from onset of the disease to first visit to our hospital ranged from 0 to 50 months, averaging 9 months. The main chief complaints were mass formation, spontaneous pain, ulceration, and abnormality of urinary stream. More than 75% of them had phimosis. Thirty-one percent had stage 1, 29% stage 2, 38% stage 3, and 2% stage 4 cancer, according to Jackson's classification. All of them were diagnosed with squamous cell carcinoma. Surgical treatment was given to 37 patients (radical or partial penectomy was performed in most cases). Chemotherapy was given to 23 patients (main chemotherapeutic agent was bleomycin or peplomycin) and irradiation to 26 patients. Five-year survival was seen in 77% of the cases, 92% in low stage group (stage 1 and 2) and 63% in high stage group (stage 3 and 4). Ten-year survival was seen in 62% of the cases, 79% in low stage group and 43% in high stage group (Kaplan-Meier method).

Adult↗
PubMed1988

[A clinical study of tumor of the renal pelvis and ureter].

We report 54 patients with urothelial tumors in upper urinary tract admitted to our hospital between July, 1962 and December, 1985. The patients consisted of 38 males and 16 females; side their ages ranged from 47 to 88 years with a mean of 63.4 years. The affected side was the right side in 21 cases, and the left side in 33 cases. Macro-or microhematuria was observed in 87% of the patients. Pathologically, 53 of the patients had transitional cell carcinoma and 1 had papilloma. Six patients had a past history of bladder tumor. Simultaneous bladder tumor was identified in 10 cases. Vesical recurrence was observed in 5 cases. Total nephroureterectomy with bladder cuff resection was employed as the surgical method in 21 cases, and total nephrectomy without bladder cuff resection in 11 patients. The actual five-year survival rate was 53% for all the patients; 52% for patients with renal pelvic tumors, 75% for those with ureteral tumors and 15% for those with renal pelvic and ureteral tumors. The patients who received nephroureterectomy had a postoperative survival rate similar to that of those who received nephroureterectomy with bladder cuff resection. A simultaneous bladder tumor lowered the survival rate.

Aged↗
PubMed1987

Effect of aortocoronary bypass surgery on coronary circulation and myocardial metabolism during atrial pacing.

Eleven patients with coronary heart disease, in whom at least one of several bypass grafts to the left coronary artery was patent, were selected for the study. The hemodynamics, coronary sinus blood flow, myocardial oxygen consumption, and myocardial lactate metabolism were evaluated at rest and during atrial pacing stress test before and after surgery. There were no significant improvements in the cardiac index, pulmonary arterial end-diastolic pressure, and left ventricular ejection fraction after aortocoronary bypass surgery. However, significant improvement of coronary sinus blood flow, myocardial oxygen consumption, and myocardial lactate extraction and consumption were found during postoperative atrial pacing compared with the preoperative findings. These results suggest that successful bypass grafting may improve myocardial lactate metabolism in ischemic lesions and contribute to the postoperative relief of angina.

Cardiac Pacing, Artificial↗
PubMed1987

Principle of a noninvasive method of measuring Max(dP/dt) of the left ventricle: theory and experiments.

In early systole, before the effects of reflected waves from the periphery become significant, the following equation applies: PA - PO = rho cu (1) where PA and PO are the instantaneous and end-diastolic pressures in the ascending aorta, rho the density of blood, c the velocity of the pulse wave in the aorta, and u the velocity of blood. Differentiation of Eq. (1) with respect to time t yields: dPA/dt = rho c(du/dt) (2) If there is no aortic stenosis, and if the pressure gradient due to the inertia of the blood during acceleration is neglected, the left ventricular pressure P is nearly equal to PA during the ejection period. Since both dP/dt and dPA/dt take their maximum values at times close to the time of aortic valve opening, the following equation applies: Max(dP/dt) not equal to Max(dPA/dt) (3) where Max signifies the maximum value of a derivative. Equation (2) reduces to: Max(dPA/dt) = rho c Max(du/dt) (4) Substitution of Eq. (4) into Eq. (3) yields: Max(dP/dt) not equal to rho c Max(du/dt) (5) Experiments were performed on seven dogs. Max(dP/dt), Max(du/dt), and c were measured during volume loading, pressure loading and unloading, and before and after administration of positive and negative inotropic agents. There was a good linear correlation (Y = 1.01X-2, r = 0.97) between Max(dP/dt) and rho c Max(du/dt). Therefore, Eq. (5) is a universal equation which holds, irrespective of the dogs and interventions employed to change the hemodynamic state.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗