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Biomedical subjects

T Kodama

Publications and source records attributed to T Kodama.

At least 703 records · Page 39Linked to original sources
PubMed1989

New projection for portography.

The right anterior caudocranial oblique (RACCO) view is proposed for improved depiction of the portal venous system. It is achieved by tilting the image intensifier 25 degrees caudal and 25 degrees-30 degrees to the right and maintaining the patient in the supine position. Transarterial portography with digital subtraction angiography was performed in the RACCO and posteroanterior (PA) views in 22 patients. Comparison of the two views revealed that the RACCO view was superior to the PA view of the left main branch in 15 patients (68%) and of the right posterior lobe branch in 19 patients (86%). The RACCO view will be useful for the evaluation of the portal system in patients with primary and secondary hepatic neoplasms in whom detailed images are important for diagnosis treatment planning.

Humans↗
PubMed1989

Interspecies homology of cytochrome P-450: inhibition by anti-P-450-male antibodies of testosterone hydroxylases in liver microsomes from various animal species including man.

P-450-male is one of the male-specific forms of cytochrome P-450 in liver microsomes of adult rats and functions as testosterone 2 alpha- and 16 alpha-hydroxylases. The purpose of this study was to examine whether forms of cytochrome P-450 cross-reactive with anti-P-450-male antibodies are present in liver microsomes of other animal species, such as male and female mice, rabbits, guinea pigs, hamsters, dogs and humans. The antibodies cross-reacted with a protein(s) in the liver microsomes of all animal species to show one or more bands on nitrocellulose paper by Western blot peroxidase-anti-peroxidase staining analysis. Qualitative as well as quantitative species differences were noted in the testosterone hydroxylases. The antibodies inhibited 2 alpha-hydroxylase in male rats, 16 alpha-hydroxylase in male rats and male and female dogs, 7 alpha-hydroxylase in female rats and male and female mice and hamsters, and 15 alpha-hydroxylase in female mice and hamsters. No clear inhibition of 6 beta-hydroxylase, which was present in all animal species, was observed. These results indicate that forms of cytochrome P-450 that are immunochemically related with P-450-male catalyze the hydroxylation of testosterone at varying positions depending on the animal species, with the exception of 6 beta-hydroxylation, which may be catalyzed by a distinct form of cytochrome P-450.

Animals↗
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

Different cross-linked types of collagen implanted in rat palatal gingiva.

Collagen membrane preparations were manufactured with the aim of enhancing wound healing following periodontal surgery. After crosslinking by various processing methods (with ultraviolet and hexamethylenediisocyanate) and to various extents, two types of collagen (atelocollagen and tendon collagen) were implanted into a dissection site within palatal gingival tissue. The time course of healing responses was investigated histologically. Collagen implantation was found to accelerate fibrous connective tissue attachment to the root surface and inhibit apical migration of the junctional epithelium. Cross-linked atelocollagen was superior in biocompatibility to the other collagen membranes studied.

Animals↗
PubMed1989

The effect of various concentrations of collagen barrier on periodontal wound healing.

Collagen membrane preparations were manufactured with the aim of enhancing wound healing following periodontal surgery. In order to clarify effects of different concentrations of collagen on wound healing, a basic study was performed. Solutions containing 0.5%, 1.0%, and 1.3% atelocollagen were treated with hexamethylenediisocyanate (HMDIC) for cross-linking, and collagen membranes were prepared with each solution. Periodontal flap surgery was performed on the palatal gingiva beside the maxillary first molar teeth in rats. The root surface of the tooth was exposed and curretted. Then, a piece of atelocollagen membrane was implanted. The healing of the wound was studied histologically and the following findings were made. (1) Apical migration of the junctional epithelium occurred within 2 weeks postoperatively. (2) The implantation of atelocollagen membrane significantly reduced the apical migration. (3) The apical migration of the epithelium did not vary with collagen concentration.

Animals↗
PubMed1989

Healing process of experimental esophageal ulcers induced by acetic acid in rats.

We studied the healing of acetic acid-induced esophageal ulcers in rats with respect to the cellular kinetics. Esophageal ulcers were induced by topical application of acetic acid to the serosal surface. Well-demarcated circular or elliptical ulcers had developed by day 3 after the acid treatment. These ulcers began to decrease in size from day 7 and had healed by day 14. Histological and cellular kinetic findings, with bromodeoxyuridine (BrdU), were degeneration of the esophageal mucosa on day 1 and ulcer formation on day 3, with an increase in the number of BrdU-labeled cells in the esophageal mucosa around the ulcer. On day 7, regenerated epithelium was found to extend towards the ulcer base and the regenerated epithelium had become thicker, with papilla formation, by day 10. On day 14, the ulcer base was covered with thickened regenerated mucosa, with a decrease in the number of BrdU-labeled cells. Marked proliferative activity of the regenerated mucosa and thickening of the esophageal mucosa, with papilla formation, were observed during the healing process.

Acetates↗
PubMed1989

Possible mechanisms of diethyldithiocarbamate-induced gastro-duodenal mucosal damage in rats.

A single s.c. injection of diethyldithiocarbamate (DDC, 1 g/kg) induced not only gastric but also duodenal mucosal damage in rats. DDC induced marked decreases in gastric acid output, gastro-duodenal mucosal blood flow and transmucosal potential difference prior to the development of mucosal lesions. Superoxide dismutase activity in the gastro-duodenal mucosa was also inhibited, while catalase and glutathione peroxidase activities gradually increased after the administration of DDC. These results suggest that a decrease in mucosal defensive mechanisms plays an important role in the development of DDC-induced gastro-duodenal mucosal damage and that oxygen-derived free radicals may also participate in the development of this mucosal damage.

Animals↗
PubMed1989

[Study on biocompatibility of titanium alloys].

The biocompatibility of two different titanium alloys, Ti-6Al-4V ELI and Ti-5Al-2, 5Fe, and pure titanium were evaluated. The results were as follows: 1) Titanium alloys were implanted into the dorsal subcutaneous tissues of the Hartley guinea-pig for 12 weeks, immersed in calf serum or in Ringer's solution for 8 weeks. The surface changes of the titanium alloys were observed by SEM and the chemical composition was analyzed by XMA. No evident surface changes were found. 2) Three hundred mg, 200 mg and 100 mg of the powders of the tested materials were immersed in 2ml of Eagle's MEM, incubated for 1-7 days, 8-21 days and 22-70 days at 37 C degrees. The amount of metallic elements dissolved in the solutions was measured by ICP and AAS. The detected corrosion rates of V and Al contained in the solution, in which Ti-6Al-4V ELI 100 mg was immersed for 1-7 days, were 194.3 +/- 17.6 and 73.0 +/- 28, 1 pg/mg alloy/day, respectively. V was released more than Al. The amount of Ti was below the detectable limit. The solution Ti-5Al-2.5 Fe 100 mg immersed for 1-7 days contained 31.9 +/- 34.4 pg/mg alloy/day Fe and 25.7 +/- 6.3 pg/mg alloy/day Al. Only in the solution 300 mg immersed for 1-7 days was Ti detected at 1.4 pg/mg alloy/day. 3) By the bacterial mutation assay of Salmonella typhimurium TA 98, Salmonella typhimurium TA 100 and Escherichia coli WP2 uvrA, the solutions, in which the tested materials were immersed, were not found to be mutagenic. 4) By the UDS assay, the grain counts on autoradiography with the solutions, in which the tested materials were immersed, were not greater than the negative control. The results suggest an excellent corrosion resistance of the titanium alloys. Mutagenicity was negative by these mutation assays, indicating that the tested alloys and pure titanium are safe for humans and animals.

Animals↗
PubMed1989

[Clinical evaluation of PIVKA-II as a marker of hepatocellular carcinoma].

PIVKA-II (protein induced vitamin K absence or antagonist-II) levels in plasma were measured using ELISA in patients with hepatocellular carcinoma (HCC). PIVKA-II was detected in 53 of 97 patients (54.6%) of HCC, and the combination assay of PIVKA-II and AFP identified 69 of 97 patients (71.1%) with HCC. However, the positive rate of PIVKA-II (6.1%) was lower than that of AFP (37.5%) in patients with HCC less than 2 cm in diameter. The concentration of PIVKA-II was markedly reduced within 2 weeks after treatment in patients with HCC showing a favorable response to Lp-TAE or Lp-TAI. Although PIVKA-II is a valuable marker for the diagnosis and follow-up of patients with HCC, it must be noted that the change to negative concentration of PIVKA-II after treatment does not mean complete necrosis of the tumor.

Aged↗
PubMed1989

Morphometrical and biochemical differences of endocrine pancreata between spontaneously hypertensive and normotensive rats with or without neonatal streptozotocin-induced diabetes.

We studied the morphometrical and biochemical changes of endocrine pancreata in spontaneously hypertensive rats (SHR) and normotensive Wistar Kyoto rats (WKY) with or without noninsulin-dependent diabetes mellitus induced by neonatal streptozotocin (STZ) treatment at 4 months of age. Female (2-day-old) neonates were intraperitoneally injected with 62.5 or 75.0 mg/kg of STZ for SHR, 87.5 or 100.0 mg/kg of STZ for WKY, and vehicle for control. In STZ-treated groups, overt hyperglycemia developed in SHR with significantly decreased serum immunoreactive insulin (IRI), whereas in WKY, hyperglycemia was very mild and serum IRI was not lowered. The number and mean size of pancreatic islets did not differ between SHR and WKY, although mean islet size was reduced by half in both compared with that in the corresponding control, respectively. Percentage distribution of insulin-positive B cells in the islet was significantly reduced more in SHR than in WKY (34% of control versus 64% of control, p less than 0.05). Furthermore, pancreatic IRI content was far more reduced in SHR than in WKY (3% of control versus 43% of control, p less than 0.001). In vehicle-treated groups, the glycemic levels and the morphometrical islets did not differ between SHR and WKY. However, serum IRI was significantly lower but pancreatic IRI content was higher in SHR than in WKY. The mechanisms of strain differences between SHR and WKY seen in the present study were discussed.

Animals↗
PubMed1989

[Prevention of renal toxicity of cisplatin by administration of bismuth subnitrate].

The effect of pretreatment with bismuth subnitrate (BSN) for prevention of the renal toxicity of cisplatin (CDDP) was examined in 44 patients with lung cancer (43 non-small cell and one small cell lung cancer). In non-small cell lung cancer cases, the effect of the antitumor activity of chemotherapeutic drugs was observed in 62% of patients pretreated with BSN, and 42% in the group without pretreatment with BSN. No antitumoral activity of chemotherapeutic drugs was suppressed by treatment with BSN. In the group without pretreatment of BSN, serum creatinine and BUN were in proportion to the number of administrations of chemotherapeutic drugs. On the other hand, no renal toxicity was shown in the group with pretreatment by BSN. No protective effect against myelosuppression with pretreatment by BSN was demonstrated, perhaps because of the influence of anti-cancer drugs apart from CDDP.

Adult↗
PubMed1989

[Possible mechanisms of diethyldithiocarbamate-induced duodenal mucosal damage in rats].

Diethyldithiocarbamate (DDC), which markedly lowers activity of Cu, Zn-superoxide dismutase (SOD), induces not only gastric but also duodenal mucosal damage in rats. In this experiment, we studied on the mechanisms of DDC-induced duodenal mucosal damage with special reference to aggressive and defensive factors. Possible importance of oxygen-derived free radicals was also investigated. Male Wistar rats weighing about 200 g received a single subcutaneous injection of DDC at a dose of 1 g/kg. Mucosal lesions such as edema, shortness of villi and shallow erosion developed from 3 hours after DDC injection. The ulcer index reached at its maximum 12 hours later. Gastric acid output was markedly inhibited from 87.7 +/- 8.7 to 14.0 +/- 2.6 microEq/kg/h (m +/- SE) 30 minutes after the administration of DDC (p less than 0.01), which gradually recovered thereafter. Duodenal mucosal blood flow before DDC injection was 144.7 +/- 12.7 ml/min/100 g, which decreased to 83.3 +/- 5.1 (p less than 0.01) 1 hour later. Transmucosal potential difference of the duodenum before DDC injection was -9.5 +/- 1.0 mV, which decreased to -3.8 +/- 1.3 (p less than 0.05) 30 minutes later. Duodenal alkaline secretion before DDC injection was 15.6 +/- 0.8 microEq/kg/h, which decreased to 5.0 +/- 0.9 microEq/kg/h (p less than 0.01) 90 minutes later. PAS-stained mucus of Brunner's glands remained unchanged by the administration of DDC. SOD activity was markedly inhibited from 57.7 +/- 4.0 to 15.7 +/- 0.9 u/mg protein 3 hours after the administration of DDC (p less than 0.01), then recovered 24 hours later.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1989

[A case of pituitary adenoma presenting binasal inferior quadrants hemianopsia].

Visual field defect due to pituitary adenoma ordinarily shows bitemporal hemianopsia. But we experienced a case presenting binasal inferior quadrants hemianopsia. A 60-year-old woman was admitted to our hospital complaining of headache and blurred vision. At ophthalmologic examination, the visual acuity on the right was 0.02 and on the left 0.3. Visual field showed a loss of bilateral inferior nasal quadrants. There was neither pallor nor edema of either of the optic disks. A computerized tomography (CT) scan showed an enhancing mass in the intra- and suprasellar region. But despite remarkable suprasellar expansion of the tumor, the straight view of bilateral carotid angiograms revealed no elevation of the first part of the anterior cerebral arteries (ACA). On the lateral view, the terminal portion of the precommunicating part of the left ACA showed rather marked anteroinferior displacement. 2 mm thin sliced CT scans at the suprasellar region revealed that the left internal carotid artery had been touching the lateral portion of the tumor and the ACA had been displaced anteriorly by the tumor. Two weeks after admission, transsphenoidal tumor resection was carried out. Total removal was achieved and histological examination showed that the tumor was nonfunctioning chromophobe adenoma. The postoperative course was uneventful except for transient diabetes insipidus. The patient's visual acuity rapidly improved to 0.8 on the right and 0.5 on the left two weeks after operation. Although there was still a tendency for left inferior nasal field defect, remarkable improvement was obtained subjectively and objectively. According to the findings of CT scans and cerebral angiograms, binasal hemianopsia may have been produced by the mechanism as follows.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenoma, Chromophobe↗
PubMed1989

Methicillin-resistant Staphylococcus aureus in nosocomial infections in the surgical ward and operating room.

In this study 214 strains of Staphylococcus aureus were isolated from clinical specimens on the surgical ward from 1983 to 1988 and in addition, 62 airborne strains were collected in the operating room. Highly methicillin-resistant strains of S.aureus (H-MRSA, MIC greater than 100 micrograms/ml) not detected in 1983 showed a significant increase in frequency by 1987 accounting for about 60% of MRSA (MIC greater than or equal to 12.5 micrograms/ml). Countermeasures instituted in 1987 such as the use of disinfectant chlorhexidine alcohol significantly decreased the frequency of MRSA and H-MRSA isolates in 1988. In our study of coagulase type, MRSA type IV strains were predominant until 1984, whereas after 1986 type II was prevalent. All airborne strains collected in the operating room were methicillin-sensitive S.aureus, with type VII currently epidemic. We therefore concluded that cross infection with MRSA took place on the surgical ward rather than in the operating room.

Cross Infection↗
PubMed1989

[Correlation between coagulase typing and antibiotic susceptibility in methicillin resistant Staphylococcus aureus].

One hundred and fifty-two strains of Staphylococcus aureus isolated from clinical specimens from 1983 to 1987 were examined in their susceptibility against various antibiotics and in their coagulase typing. The isolation frequency of methicillin resistant strains (MRSA) was 61.6%, and highly methicillin resistant (MIC greater than 100 micrograms/ml) group occupied 81.3% of MRSA in 1987. From the study of coagulase type, it was found that current epidemic strains in our ward was type II. In MRSA, type IV strains were predominantly isolated until 1984, but after 1986 most of all MRSA strains belonged to type II. According to the coagulase type-classification of MRSA, the isolation frequency of type II was 97.5% of highly methicillin resistant group. Type II strains were more sensitive to MINO and OFLX than type IV, although in the susceptibility to DMPPC type II was less sensitive than type IV. In type IV, the percentage of beta-lactamase-producing strains was 79.3%, and type II, 33.3% with the high significance of statistical difference (p less than 0.01). In conclusion, a close correlation was suggested between beta-lactamase producing activity and the mechanism of resistance to non-beta-lactam antibiotics as to MINO, OFLX in type IV strains. On the other hand, in type II strains the mechanism of resistance seemed to be simply explained by changes of penicillin-binding-protein (PBP), and there was little concern with beta-lactamase, and other antibiotic-modifying enzymes.

Anti-Bacterial Agents↗
PubMed1989

[Two cases of thymic carcinoid].

Two cases of thymic carcinoid tumor were reported. Case 1 was 64-year-old male who was admitted to our hospital with a complaint of dyspnea. He was proved to have a huge anterior mediastinal tumor by chest X-ray and chest CT. After radiation therapy, the tumor was resected on February 5, 1981. Pericardium was partially resected and showed tumor invasion. Sixty-four days after operation, he died due to respiratory insufficiency. Case 2 was 71-year-old male who was pointed out to have an abnormal shadow by X-ray mass screening and was admitted to our hospital. Chest X-ray and chest CT revealed the presence of an anterior mediastinal tumor. Resection of the tumor was done on February 13, 1986. Although the tumor showed mediastinal lymph node metastasis and invaded to the pericardium and the right lung, it was resected completely. Cytological examination of pericardial effusion showed tumor cells at the time of resection. He is now quite well and without any evidence of recurrence 3 year and 1 months after operation. Histopathologically, the tumors of two cases consisted of relatively uniform cells with abundant clear or slightly eosinophilic cytoplasm and regularly and centrally located nuclei. Mitotic figures were occasionally seen in both cases. Many tumor cells were positively to Grimelius stain. On the other hand, Fontana-masson stain was negative. Immunohistochemically, the tumor cells were positively stained with anti-NSE and anti-GRP antibodies in Case 1 and with anti-NSE antibody in Case 2.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗