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Biomedical subjects

Y Tada

Publications and source records attributed to Y Tada.

At least 19 recordsLinked to original sources

Surgical treatment of Takayasu arteritis.

From 1959 to 1991, 93 patients underwent vascular reconstruction for Takayasu arteritis at our institution. The details of the cases were as follows: 16 were of type I (brachiocephalic ischemia), 48 type II (hypertension), 13 type III (extensive lesions with cerebral ischemia and hypertension), and 16 type IV (aneurysms). Carotid reconstruction, repair of atypical aortic coarctation, renovascular reconstruction, and aneurysm repair were performed independently or in combination. Nine operative deaths occurred, 8 cases of which were operated before 1970. The most serious of the delayed complications was suture line aneurysm formation, which was encountered in ten cases. The aneurysms were often found long after the operation, some of them developing even after more than 20 years. Takayasu arteritis is characterized by extensive inflammation and destruction of the medial elastic fibers and long term postoperative observation is mandatory to improve the late survival rate.

Aortic Aneurysm

False aneurysm as a late complication of division of a patent ductus arteriosus.

A 58-year-old male patient who had a huge false aneurysm as a late sequela of division of patent ductus arteriosus was surgically managed with success. It is noteworthy that 24 years had elapsed from the initial operation until recognition of the aneurysm. The pathogenesis and method of the surgical treatment are discussed.

Aortic Aneurysm

Acute renal toxicity of thiabendazole (TBZ) in ICR mice.

The acute toxic effects of thiabendazole [2-(4'-thiazolyl)benzimidazole; TBZ] on the kidneys of ICR mice were investigated. The mice were given 0, 250, 500 or 1000 mg TBZ/kg body weight by gavage (using olive oil as a vehicle), and the kidneys were subjected to pathological examination at 1, 3, 5 or 24 hr after dosing. Gross findings were slight enlargement and the presence of whitish areas (white maculae) in kidneys of treated mice at 3, 5 or 24 hr after dosing. Histological findings were desquamation of degenerated cells in proximal tubules of treated mice at 1 hr. Dilation of proximal, distal and collecting tubules was apparent in treated mice at 3, 5 and 24 hr. TBZ-induced renal injury was reduced by pretreatment with inducers of the microsomal monooxygenase system (sodium phenobarbital, beta-naphthoflavone and 3-methylcholanthrene) and were enhanced by pretreatment with inhibitors of that system (2-diethylaminoethyl-2,2-diphenylvalerate hydrochloride and piperonyl butoxide). The concentration of TBZ in blood at 1 or 5 hr after dosing was lower in mice pretreated with microsomal monooxygenase system inducers and was higher in those pretreated with the inhibitors, than in those given TBZ alone. These results suggest that TBZ-induced renal injury may be attributable to the parent compound rather than its metabolites. Measurement of organic ion uptake into renal slices revealed significant depression of [1-14C]tetraethylammonium bromide (TEA) uptake in treated mice at 1 or 5 hr, whereas uptake of p-[glycyl-2-3H]aminohippurate (PAH) was not depressed at 1 or 5 hr after dosing. The reduction in uptake of TEA is interpreted as the result of competitive suppression of the tubular transport of TEA by TBZ. TBZ-induced renal injury was reduced by organic cation transport inhibitors [N'-methylnicotinamide (NMN) or thiamine] but not by organic anion transport inhibitor [p-(dipropylsulphamyl)benzoic acid probenecid], suggesting that the reduction of TBZ-induced renal injury is the result of competitive suppression of the tubular transport of TBZ by NMN or thiamine.

Administration, Oral

Case report: nifedipine-rifampicin interaction attenuates the effect on blood pressure in a patient with essential hypertension.

A 72-year-old woman with 5-year history of essential hypertension developed peritoneal tuberculosis. The patient's hypertension, which had been well-controlled by long-acting nifedipine, deteriorated after the administration of rifampicin, an antitubercular agent. During use of nifedipine and rifampicin, both the peak plasma concentration and the area under the curve of nifedipine decreased markedly to about 40% of those without rifampicin. The findings suggest that rifampicin may increase the elimination of nifedipine, presumably by induction of its hepatic metabolism. Nisoldipine, another calcium antagonist, also failed to lower the patient's blood pressure, when given in combination with rifampicin. Taken together, these findings indicate that more caution should be urged when calcium antagonist is prescribed along with rifampicin.

Adrenergic alpha-Antagonists

Analysis of body-length distribution of Dirofilaria immitis in the cardio-pulmonary blood vessel of naturally infected dogs in Shiga Prefecture, Japan.

Body-length frequencies of Dirofilaria immitis collected from the cardio-pulmonary blood vessel of the dogs were studied in Shiga Prefecture. Japan, in October 1983 and in January and May 1984. The frequencies were not distributed normally because they included the populations of shorter-bodied worms, probably the growing younger worms, whereas the distributions of the body length of worms collected in July 1983 were proved to fit the single normal distribution. From the results of body-length distribution analysis, the worms collected in different seasons were each composed of 1 to 3 groups with different mean body-lengths, standard deviations and composition rates and successive changes were observed in the distribution patterns. According to the analysis of population structures, the infective season was estimated to range from April or May to October or November in 1983 from the respective ages of shorter-bodied worm groups. The annual rates of first infection and re-infection in 1983 determined by the population of shorter-bodied females collected in January were 48% and 93% respectively and the number of newly infecting females per dog ranged from 1 to 27 with a geometric mean of 8.5. The numbers of newly infecting female worms were distributed following the negative binomial and Poisson distributions in newly infected and already infected dogs respectively.

Animals

[Determination of nicarbazin in imported chicken].

The confirmation and quantitative analysis of nicarbazin (NCZ) in imported chickens were made by high performance liquid chromatography equipped with a photodiode array detector. The results showed that 1 out of 7 chicken samples contained over 30 ng/g of NCZ. The concentrations of NCZ varied from 10 to 120 ng/g according to the parts of the NCZ positive chicken samples.

Animals

[Migration test of lead and cadmium from plastic wares in contact with food].

Release of lead and cadmium from plastic tableware was examined. Samples were treated with 2 ml of 4% acetic acid or 0.1N HCl per cm2 of the surface area at 60 degrees C or 95 degrees C for 30 min. No migration of lead and cadmium from samples containing up to 391 ppm lead or 6863 ppm cadmium was observed.

Cadmium

[Determination of volatile substances and leachable components in polystyrene food contact wares].

Material and migration tests of food-contact plastic wares made of polystyrene were carried out. The average concentration of volatile substances (sum of toluene, ethylbenzene, isopropylbenzene, n -propylbenzene, and styrene) in materials was 861 +/- 692 ppm. Styrene was observed in 95% of 19 samples. alpha-Methylstyrene, which is one of the material compounds of polystyrene, was detected in one sample. Release of volatile substances into n-heptane was not observed at the detection limits of 0.1 ppm.

Cooking and Eating Utensils

[Establishment of an experimental model with a high frequency of liver metastasis and recurrence from gastric VX2 cancer: histological analysis of the developmental process of primary and metastatic cancer lesions].

An experimental model with a high frequency of liver metastases and recurrence was established by the non-resection and resection of gastric cancer lesions induced with implanting VX2 cancer cells into the stomach of 35 rabbits. The frequency of liver metastases was 0% on Days 7 and 14, 40% on Day 21 and 60% on Day 28 in the non-resection group. In the resection group, primary lesions were resected on Days 7, 10 and 14, and the metastases were found in all the animals 14 days after the resection on Day 14, though they did not occur in every animal 18 and 21 days after the resection on Days 10 and 7. The metastatic lesions were found in the peri-lobular area, accompanied by cancer emboli in the interlobular veins. Vascular invasion was found in almost all (90%) the primary lesions of animals with liver metastases or recurrence. These results suggest that hepatic micrometastases occur between 10 and 14 days after implantation, and that vascular invasion plays an important role in the formation and extension of liver metastases or recurrence. They also suggest that this model is utilized as a useful tool for studying many aspects of liver metastases or recurrence in gastric cancer.

Animals

[Operative strategy for thoracoabdominal aortic aneurysm with concomitant reconstruction of four main abdominal branches].

A thoracoabdominal aortic aneurysm (TAAA) involving major abdominal branches remains still difficult to be managed. From 1983 to 1990, we successfully operated five such cases. Our operative strategy for TAAA which necessitates concomitant reconstruction of four major abdominal branches is i) to utilize temporary bypass to maintain distal perfusion during aortic cross-clamping, ii) to reconstruct bilateral renal arteries prior to aortic clamping in order to shorten renal ischemic time as much as possible, iii) to reconstruct celiac and superior mesenteric arteries by Crawford's method, iv) to reconstruct two pairs of intercostal arteries by using diagonal anastomosis in the proximal site, and v) to divide the left renal vein temporarily for easy manipulation of renal arteries. All five cases were recovered uneventfully. This procedure, in which the renal ischemic time is saved as short as possible, is considered a safe and reasonable one for thoracoabdominal aortic aneurysms.

Adult

Infantile multilocular renal cyst.

A case of a Japanese 14-month-old male infant with multilocular renal cyst is presented. He was admitted with a chief complaint of an abdominal mass. Although clinically and radiographically multilocular renal cyst in the right kidney was suspected, total nephrectomy was performed because of extreme difficulty of partial nephrectomy and impossibility of complete neglect of malignant cystic tumor. Microscopically, immature glomeruloid tissue, primitive tubules, rhabdomyocytes and nerve fibers were noted. The histological diagnosis of multilocular renal cyst with partially differentiated dysplasia was made. Since the first report by Edmunds in 1892, the etiology of multilocular renal cyst has been discussed for years. In our present case, the pathologic findings suggest that multilocular cystic formation in the right kidney might be the result of developmental disturbances.

Humans

Synthesis and regulation of the fourth component of complement (C4) in the human monocytic cell line U937: comparison with that of the third component of complement (C3).

Production of the fourth component of complement (C4) by the human monocytic cell line U937 and its regulation were investigated in comparison with the production of the third component of complement (C3) in a cell culture system. Although no detectable C4 was produced by U937 without stimulation, U937 was induced by recombinant interferon-gamma (IFN-gamma) to synthesize C4 in a dose- and time-dependent fashion. The production of C4 was reversibly inhibited by cycloheximide, indicating that it resulted from de novo synthesis. The C4 synthesized by U937 cells was functionally active as assessed by haemolytic assay. SDS-PAGE following biosynthetic labelling showed that subunit structure of C4 synthesized by U937 cells was identical with that of plasma C4 but that molecular weight of alpha-chain was greater than that of plasma C4. We compared the regulation of C4 synthesis with that of C3 synthesis. Although C3 synthesis by U937 cells was enhanced by IFN-gamma, lipopolysaccharide (LPS) and phorbol myristate acetate (PMA), C4 synthesis was induced only by IFN-gamma. LPS and IFN-gamma induced a synergistic increase in C3 synthesis by U937 cells. U937 cells incubated with LPS and IFN-gamma synthesized a greater amount of C4 than those incubated with IFN-gamma alone. Thus it was demonstrated that the synthesis of C3 and C4 was independently regulated. This study shows that the U937 cell line provides a useful model for studies on the synthesis of complement proteins and on the regulation of complement production.

Cell Line

Leiomyosarcoma of the small intestine associated with von Recklinghausen's disease: report of a case.

A 54-year-old woman with intestinal multiple smooth muscle tumors including leiomyosarcoma, epithelioid leiomyoma, and leiomyomas in association with von Recklinghausen's disease is reported. Thirteen years after the excision of an intestinal leiomyosarcoma, another leiomyosarcoma arose in a different area of the jejunum and was also completely resected. Although leiomyomas are occasionally recognized in patients with von Recklinghausen's disease and a gastrointestinal neoplasm, there have been no other reports of leiomyosarcomas. Careful observation of the tumor is necessary and, if a rapid increase in tumor size is recognized, malignant tumor may have arisen and early surgical treatment is required.

Aortography

Rapid isolation of a rice waxy sequence: a simple PCR method for the analysis of recombinant plasmids from intact Escherichia coli cells.

Polymerase chain reaction (PCR) is an efficient method for obtaining a desired nt sequence if both required primers can hybridize to the target DNA molecule specifically. A rapid and simple PCR-based method for analyzing plasmids using intact cells was established. An attempt to target a rice waxy sequence by PCR using homologous primers was also carried out. In three cases, specific fragments were amplified and their nucleotide sequences were determined. However, the cloned rice waxy gene contained base substitution mutations. The cumulative frequency of mutation after 30 polymerization cycles was estimated to be one in 500 bp.

Base Sequence

Expression of a monocot LHCP promoter in transgenic rice.

The beta-glucuronidase (GUS) gene linked to the promoter of rice light harvesting chlorophyll a/b-binding protein of photosystem II (LHCPII) was introduced into rice by electroporation. Expression of the GUS gene with the LHCP promoter in transformed protoplasts and callus was much lower than with the cauliflower mosaic virus (CaMV) 35S promoter. In green organs, however, LHCP-GUS activity with the LHCP promoter was 10-fold higher than that with the CaMV 35S promoter. Expression of the LHCP-GUS gene was detected in leaves, stems and floral organs but not in roots. Histochemical analysis of leaves showed that the GUS gene was expressed specifically in green tissues. In selfed seeds of the transformants, GUS gene expression was detectable only in the germinated embryos after greening. Northern blot analysis revealed that transcription of the GUS gene with the LHCP promoter was not detectable in dark-grown seedlings of transformants but was induced by exposure to light. These results show that regulation of the introduced chimeric gene in transgenic plants was characteristic of the LHCP gene itself.

Blotting, Southern