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Biomedical subjects

H Tamura

Publications and source records attributed to H Tamura.

At least 361 records · Page 20Linked to original sources
PubMed1989

Frequency of cell transformation by the small DNA tumor viruses: infection of proliferating cells and quiescent cells.

Small DNA-containing tumor viruses (simian virus 40, mouse polyoma-virus, and adenoviruses) malignantly transform fibroblasts of the susceptible rodents. Fibroblasts can exist, in vitro and in vivo, in either of the two states: the proliferating state or the quiescent state. In the present study, we examined whether the state of fibroblasts at the time of exposure to these DNA viruses affects the frequency of transformation. Dense-focus formation in monolayer culture of rat 3Y1 fibroblasts was used to quantitate transformation. Results show that the frequency of transformation by simian virus 40 and mouse polyomavirus was reduced when cells were in the proliferating state at the time of virus inoculation as compared to cells in the quiescent state, whereas that by adenovirus type 12 was similar in the two cellular states. The reduction of the frequency of transformation in proliferating cells infected with simian virus 40 was also observed in BALB/c 3T3 mouse cells. Mechanisms underlying the difference between the two cellular states and the difference between the papovavirus and adenovirus in this aspect of transformation remain to be investigated.

Adenoviridae↗
PubMed1989

Gastrointestinal flora of cotton rats.

The gastrointestinal (GI) flora of cotton rats was examined. No lactobacilli were detected in any part of the GI tract. Anaerobes, including Peptococcaceae, Bacteroidaceae, bifidobacteria and eubacteria, were the predominant bacteria in the stomach, small intestine, caecum and faeces. Aerobes and facultative anaerobes, including Enterobacteriaceae and streptococci, were detected at low numbers and very low frequency of occurrence in all parts of the GI tract. Sixty-one isolates of bifidobacteria were recovered from the stomach, small intestine, caecum and faeces of cotton rats. They were identified as Bifidobacterium animalis, B. pseudolongum biovar a and b. The study showed that the GI flora of cotton rats seem to be very different from the GI flora in other rodents.

Animals↗
PubMed1989

[Electromyographic study on masticatory function of the telescope denture wearers in the Kennedy Class II mandible].

Masticatory function of 10 telescope denture wearers in the Kennedy class II mandible patients was evaluated with electromyography. Electromyographic activity during mastication with kamaboko and peeled raw carrot was recorded from bilateral masseter and the anterior part of temporal muscles at each interval: Before treatment, immediately after denture insertion and 2, 4, 6, 8 weeks after respectively. Mean of duration, interval and cycle of EMG activities, coefficient of variation and average variation were calculated. The results were as follows: 1. Means of duration and cycle times decreased immediately to 2 weeks after denture insertion. 2. EMG activities during raw carrot chewing became regular immediately to 2 weeks after denture insertion, and within 4 weeks in kamaboko chewing. These results suggest that telescope dentures would be adapted to stomatognathic system within short period after denture insertion.

Denture, Overlay↗
PubMed1989

[Prosthodontic treatment for a partial mandibulectomy patient. A mandibular non-reconstructed case].

One of the most consistently frustrating areas of maxillofacial rehabilitation is the treatment of patients who have had radical cancer surgery of the tongue, floor of the mouth, and mandible. The patient described in this report, was a 66-year-old man who had squamous cell carcinoma of the right jaw. The right body of the mandible distal to the right cuspid was resected, and this part of the mandible was not reconstructed. For this mandibulectomy patient, we have treated with the removable partial denture using 30 degree teeth and TS telescope crown as retainer, registrating maxillomandibular relation with Gothic arch tracer and MKG. In addition, masticatory function in this patient was evaluated on tooth contact, tapping pattern, masticatory efficiency and rhythm of mastication. Consequently, 4 to 8 weeks later, tapping pattern and centric occlusion was stabilized, and masticatory function was improved. We will continue to observe this case in long term.

Aged↗
PubMed1989

[Study on grinding of base metal alloys. 4. Constant pressure grinding of a Ni-Cr alloy with vitrified wheels].

The grinding techniques and the constituent element of vitrified wheels suitable for a 13% Cr-Ni dental casting alloy were determined. The lever-type grinding test machine used in the previous study was modified so that a work might be ground under a constant pressure as it moved reciprocally within a short stroke along the tangential direction of a rotating wheel. The grinding performance of two marketed wheels and eleven experimental wheels with different constituent elements was tested. Abrasive grains on the working surface of alumina wheel wore extremely due to abrasive attrition. Carborundum wheels proved to be more suitable for grinding of the comparatively soft Ni-Cr alloy. Not only depressing a wheel against a work but also moving the wheel over it with heavier pressure should be desired for the maximal grinding efficiency. The experimental carborundum wheels exhibited much the same performance as the marketed carborundum wheel under a less grinding pressure that 100 gf. Only the wheel of grain size #150 bonded with 19% binder wore obviously under the pressure of 150 or 200 gf and provided about two times the performance of the marketed wheel.

Aluminum Oxide↗
PubMed1989

[Study on grinding of base metal alloys. 5. Constant pressure grinding of a Ni-Cr alloy with electro-deposited wheels].

The grinding techniques and electro-deposited wheels suitable for a 13% Cr-Ni dental casting alloy were determined. The lever-type grinding test machine modified in the previous study was used to investigate the grinding performance of experimental wheels of CBN- and diamond-particles. Depression of the diamond wheel against the work yielded unfavorable grinding results. Not only depression of the wheel against it but also moving the wheel over it with a heavier pressure is desired for higher grinding efficiency and its durability. Probably, the undurability of this wheel is associated with abrasive attrition due to oxidation or some chemical reaction with the work. The CBN wheel had not been suitable for the Co-Cr alloy tested in the third paper, but it exhibited very excellent performance for grinding of the Ni-Cr alloy, even without being moved over the work. Although being high in cost, the CBN wheel may pay for the very high performance and its durability.

Chromium Alloys↗
PubMed1989

The influence of dialysis solution on the exercise capacity in patients on CAPD.

The present study was conducted to see whether the exercise capacity can be altered by intraperitoneal dialysis solution in patients on CAPD. Symptom-limited progressive treadmill tests with respiratory gas analysis were performed in patients on long-term CAPD, and exercise time (ET), maximal oxygen uptake (VO2 max) and ventilatory anaeorbic threshold (AT) were obtained. The treadmill tests were carried out before and after the drainage of 2-liters of dialysis solution. The dialysate bag with the fluid had either been carried by patients on their backs (test A) or been kept apart from their bodies (test B) during exercise, i.e. an apparent body weight in test B without the CAPD bag decreased by 2 kg as compared with the control. VO2max, AT or ET in test A did not change, whereas ET in the test B was prolonged after the drainage of dialysis solution (before: 437 +/- 170 sec, after: 479 +/- 158 sec, n = 10, p less than .01). No change was noted in VO2max or AT in test B. We conclude that the dialysis solution retained in the peritoneal cavity affects ET by acting as an extra-weight, although the solution has no influence on VO2max and AT.

Adult↗
PubMed1989

[Operative indication for aortic valvuloplasty by rasping procedure from the point of histopathologic evaluation].

Rasping procedure is proposed by the author as one of the methods of aortic valvuloplasty and defined as shaving the surface of rheumato-degenerative aortic valve by using the electric rasp. Materials were the removed rheumato-degenerative aortic valves as specimen, and classified into 3 groups. The first group (type I) was valve lesion limited to valve free edge, second (type II) was mild thickening entirely, third (type III) was severe thickening with calcified degeneration. Rasping procedure was performed for the thickened portion of the valve specimen by the electric rasp. Morphologic examinations after rasping procedure were evaluated by histopathologic study. Histopathologically, there was hyaline degenerative connective tissue in superficial layer above the collagen fiber's layer in rheumato-degenerative thickened valve in type I. This hyaline degenerative connective tissue was considered to be fragile and pathologic in the tissue structure. Rasping procedure could remove this connective tissue layer. Type II, there was the similar finding to the type I from the free edge to the mid portion of the cusp. So, Rasping procedure was effective for type I and type II valve degeneration. On the contrary, the calcified lesion (type III), rasping procedure was not effective in valve coaptation and the pathological findings showed the fragmentation in the calcified layer. In the pathological comparison with the slicing procedure for type II by the surgical knife, there was a crack and cleft in the collagen fiber's layer in the case of slicing procedure. It can be concluded the results of histopathological study of the rasping procedure proved to be superior to the conventional aortic valvuloplasty (slicing method).

Aortic Valve↗
PubMed1989

[Rapid diagnosis of gram-negative bacteriuria with endotoxin-specific chromogenic test].

Limulus amebocyte lysate test is a simple, yet sensitive laboratory method for detecting endotoxin. Although the specificity of the test was questioned, we recently solved this problem by removing a (1----3)-beta-D-glucan-sensitive factor G from the lysate (Endospecy, Seikagaku Kogyo Co., Ltd, Tokyo). In this study, we have established a method for the determination of endotoxin urine in using Endospecy. An aliquot of 0.2 ml of Endospecy dissolved in 4.4 ml of 0.1 mol/l Tris-HCl buffer (pH 8.0) was added to 5 microliter of urine sample. The mixture was incubated at 37 degrees C for 30 min. After diazo-coupling, absorbance was measured at 545 nm. The standard curve using Escherichia coli 0111: B4 endotoxin showed a good linearity. The addition-recovery test of various endotoxins showed nearly 100% recovery. Normal urine contained less than 60 pg/ml of endotoxin. Urine from patients with Gram-negative bacteriuria showed definitely high values, whereas urines infected either with Gram-positive bacteria or with fungi all showed nearly normal values. This method will be useful as a rapid and reliable test for the diagnosis of urinary tract infection with Gram-negative bacteria.

Endotoxins↗
PubMed1989

Immunohistological identification of T and B cells in normal and malignant tissues of the uterine endometrium.

We examined the state of T and B cells in tissues from 61 cases of endometrial cancer by immunohistochemistry with monoclonal antibodies. In cancer tissues, T cells frequently appear in clusters at the tip of the infiltrating cancer. As to age, both T and B cells were rare in 9 out of 11 cases involving endometrial cancer in patients in their 40s. In the normal endometrium, infiltration of numerous T cells was seen in only 2 out of 27 cases (7.4%). However, it was seen in cancer tissues in 28 out of 61 cases (45.9%). Thus the infiltration of numerous T cells into cancer tissues was confirmed. Within the same uterus, T cells seldom infiltrated into the area of the benign endometrium while T cells were seen in large numbers in the cancer foci. This indicates that T cells infiltrate after having recognized cancer cells. Compared to stages I and II, T cell infiltration tended to decrease in stages III and IV. While no fixed relation was found between the degree of histologic differentiation and T cell infiltration, fewer T cells were observed in the cases where cancer penetrated to the depth of cancer invasion and where it occupied a large area. Thus, it was assumed that in the host-immune defence mechanism in particular, T cell infiltration played a key role in tumor immunology of patients with endometrial cancer.

Adult↗
PubMed1989

[Diagnosis of paraaortic and pelvic lymph node metastasis by ultrasound guided percutaneous fine needle aspiration biopsy (FNAB)].

Ultrasonography (US) was performed in patients with gynecologic malignancies to detect paraaortic and pelvic lymphadenopathy. US of paraaortic lymph nodes was performed in 32 patients. Of the 32 patients 17 had lymphadenopathy, and ultrasound-guided percutaneous fine needle aspiration biopsies (FNAB) were therefore performed in 16 of these 17 cases. Of these 16 patients, 11 were positive and 5 were negative FNAB. US of pelvic lymph nodes was performed in 68 patients. Of the 68 patients 14 had lymphadenopathy, and FNAB were performed in 8 of these. All 14 of these FNABs were positive. There were no major complications from due to FNAB. It is therefore concluded that ultrasound-guided percutaneous FNAB is very useful in detecting metastatic lymph nodes of gynecologic malignancies.

Aorta, Abdominal↗
PubMed1989

[Coronary artery stenosis following aortic valve replacement--a case report].

A case with severe left main trunk (LMT) stenosis nine months after aortic valve replacement was presented. The patient, 57-year-old female, underwent aortic valve replacement with a tilting disk valve (Omnicarbon 21 A). Her postoperative course was uneventful, but angina pectoris developed after nine months. Coronary angiography was performed and revealed 99% LMT stenosis. Operation was performed with OTCA to LMT and with a saphenous vein graft to left anterior descending artery. Coronary artery stenosis following aortic valve replacement may be dangerous and it must be treated as soon as the diagnosis is established.

Aortic Valve↗
PubMed1989

[Surgical treatment of Taussig-Bing malformation in an adult--a case report].

With the development of pediatric cardiac surgery, the surgical treatment of Taussig-Bing malformation has been common in frequency and a majority of these cases are reported. However, because the patient's condition is so critical in the early stage of life, the importance of adequate initial operation is emphasized, and this area is restricted to the operative cases of child patient. In this clinical study, the operation for 41-year-old adult patient with Taussing-Bing malformation was successfully performed using the Kawashima's procedure, and we would like to report the detailed operative procedure as well as its clinical courses. This patient was female of 41 years of age and at surgery, this case was found to be the Taussig-Bing malformation associated with pulmonic stenosis, and the operation for intracardiac repair was carried out using intracardiac conduit (5 x 4 cm) and also extracardiac conduit (5 x 3 cm). It is reported that there are many operative procedure available in child patients but we believe that Kawashima's procedure is probably the best choice of operation for adult patients because of its simplicity.

Adult↗
PubMed1989

[Regulation of progesterone accumulation in dissociated luteal cells on day 15 of pregnancy in rats].

Luteal cells from the corpora lutea of rats on day 15 of pregnancy were suspended in DMEM-F12 and progesterone accumulation was measured by radioimmunoassay. Progesterone accumulation increased steadily over eight hours and then gradually decreased. Progesterone accumulation was seen to increase with the addition of BSA and 25-hydroxycholesterol. At doses of 12 ng/ml and 600 ng/ml hCG, progesterone accumulation increased, but was seen to decrease at a dose of 30 micrograms/ml hCG. However, the addition of cyclohexamide alone had no effect on progesterone accumulation, but the simultaneous addition of cyclohexamide and hCG blocked the effects of hCG in a dose related manner. These data indicate that progesterone production by rat luteal cells depends on cholesterol availability. The results reveal that hCG stimulates progesterone production by a process requiring new protein synthesis.

Animals↗