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Biomedical subjects

S Kitamura

Publications and source records attributed to S Kitamura.

At least 577 records · Page 32Linked to original sources

Sex-linked recessive lethal test of Drosophila melanogaster after exposure to 50-Hz magnetic fields.

To determine whether a 50-Hz magnetic field will induce mutations, a sex-linked recessive lethal test of Drosophila melanogaster was performed. Adult flies were exposed at an rms flux density of 500 mu T or 5 mT to the homogeneous field of a Helmholtz coil. The ambient field to which controls were exposed was less than 1 mu T. Exposures took place continuously for 13 to 14 days, which correspond to the life cycle of Drosophila at 25 degrees C. About 10,000 X-chromosomes were tested at each flux density. Recessive lethal mutation rates of 0.13, 0.21, and 0.18 percent were observed, respectively, for control, 500-mu T, and 5-mT conditions. By the Kastenbaum-Bowman significance test, the recessive lethal mutation rates in the 500-mu T and 5-mT conditions did not differ from the mutation rate of controls.

Animals↗

Internal thoracic artery grafting for congenital coronary malformations.

We report 2 patients with congenital coronary anomalies (atresia of left main coronary artery and anomalous origin of the left coronary artery from the pulmonary artery) successfully treated with single or double internal thoracic artery grafting. Because the internal thoracic artery has a potential for circumferential as well as longitudinal development, and because of the uncertainty of ultimate vein graft function, we believe that the internal thoracic artery is the best graft material for the treatment of congenital coronary malformations requiring bypass operation in children, adolescents, or even in adults.

Child↗

Angiographic demonstration of no-flow anatomical patency of internal thoracic-coronary artery bypass grafts.

To clarify the no-flow situation of the stringlike internal thoracic artery graft, we angiographically examined such grafts by temporarily occluding the recipient coronary artery with a percutaneous transluminal coronary angioplasty balloon and were able to reveal anatomical patency of the internal thoracic artery graft in 2 patients 1 year and 3 years after the operations. Thus, there is a possibility that internal thoracic artery grafts may continuously maintain anatomical patency even under no-flow situations just like nonfunctioning collateral vessels and may function properly later as a graft when the native coronary flow decreases. Also, this angiographic technique can be a new method for detecting anatomical patency of no-flow and functionally closed internal thoracic artery grafts.

Anastomosis, Surgical↗

Effects of hormonal supplements on the maintenance of cardiac function in potential donor patients after cerebral death.

It is well-known that cardiac function in cerebrally dead patients rapidly deteriorates, leaving the organ unfit for donation. This study investigated whether or not cardiac function in patients with cerebral death can be maintained in a desirable condition with hormonal supplementation. In studies of changes in hormones before and after cerebral death, insulin, glucagon, triiodothyronine, thyroxine, cortisol, vasopressin, epinephrine, and norepinephrine values were measured with a lapse of time after cerebral death. Among them, triiodothyronine and cortisol levels were markedly reduced after cerebral death; therefore, these two hormones were selected as hormonal supplements. The average period from the judgment of cerebral death to cardiac arrest was 4.3 days in 12 patients with no hormonal supplement (group I) and more than 11.5 days in 4 patients with hormonal supplement (group II). This period for patients in group II was significantly longer (p less than 0.05). In 2 of the group II patients the hormonal supplementation was discontinued at the family's request, and in the other 2 patients, it was discontinued because of proposed renal donation. Hemodynamic comparisons between the two groups showed that the mean arterial pressure and the left ventricular maximum dp/dt were significantly higher (p less than 0.01) as was the cardiac index (p less than 0.05) on the 3rd day after cerebral death in members of group II. Thereafter, in group II, an excellent hemodynamic state was maintained until hormonal supplements were discontinued. We conclude that the triiodothyronine and cortisol supplements were effective in the maintenance of cardiac function in patients after cerebral death.

Adolescent↗

An HRP study of the location of the motoneurons supplying the tensor veli palatini muscle of the rabbit.

Location of the motoneurons supplying the tensor veli palatini muscle of the rabbit was examined with the retrograde labeling technique following intramuscular injection of HRP. Labeled motoneurons were ipsilaterally located in the ventral or ventromedial portion of the rostral two-thirds of the motor trigeminal nucleus at the level of about 6.0 to 8.5 mm rostral to the obex. The location of the labeled motoneurons was ventromedial to the region supplying the masseter, the temporalis, and the medial pterygoid muscles and ventral to the region supplying the anterior digastric and the mylohyoid muscles, the location which coincided with the lateral pterygoid region. The labeled motoneurons were scattered around or in this region.

Animals↗

A high-performance liquid chromatographic method for the quantitative enantioselective analysis of mefloquine stereoisomers.

A rapid quantitative, enantioselective HPLC method for the analysis of the four stereoisomers, (+) and (-) erythro and (+) and (-) threo forms, of mefloquine has been developed using a Chiralpak Ad analytical column containing amylose tris-3,5-dimethylphenyl carbonate coated on silica gel and hexane/ethanol/diethylamine (96:4:0.1, v/v%) as the mobile phase. This method made it possible to quantitate small amounts of threo form in the presence of the erythro form of mefloquine, the form which is used as the active ingredient in commercial mefloquine tablets. Tablets from three sources were studied to estimate their optical purity, and it was found that tablets from one source contain 0.27 w/w% of the (-)-threo and 0.25 w/w% of the (+)-threo form, tablets from the second source contain 0.056 and 0.042 w/w% (-)- and (+)-threo, respectively, and tablets from the third source contain 0.052 w/w% (+)-threo, with the remainder erythro.

Chromatography, High Pressure Liquid↗

Kinetic study of the transformation from tetrahydrate to monohydrate of a new antiallergic, sodium 5-(4-oxo-phenoxy-4H-quinolizine-3-carboxamide)-tetrazolate.

Two hydrates (tetrahydrate, I, and monohydrate, II) of a new antiallergic, sodium 5-(4-oxo-phenoxy-4H-quinolizine-3-carboxamide)-tetrazolate (FR71021), were prepared and characterized by means of infrared spectrometry, thermal analysis, and power X-ray diffraction spectrometry. While I was confirmed to dehydrate readily resulting in an anhydrate form (noncrystalline form) below its critical relative humidity for dehydration, I was also transformed into II under humid conditions. The transformation kinetics from I to II were investigated under varying temperature and humidity conditions by a powder X-ray diffraction technique. The transformation mechanism followed a zero-order reaction, and the apparent transformation rate constant (k) could be described as a function of water vapor pressure (P), temperature (T), and the interaction orders between water vapor pressure and the samples (s): k = A.exp(-Ea/RT).Ps, where Ea is the activation energy and R is the gas constant.

Biotransformation↗

Incidence of Paneth cells in minute tubular adenomas and adenocarcinomas of the large bowel.

This study attempted to demonstrate the incidence of Paneth cells within large bowel tubular adenoma and adenocarcinoma according to location and macroscopic appearance using minute tumors (up to 5 mm in size). We have shown that Paneth cells were sometimes seen in the early stage of the development of large bowel epithelial neoplasia. According to the macroscopic appearance (elevated or depressed type), in large bowel epithelial neoplasia, there was a statistical difference between the depressed type (32.5%, 14 of 40 cases) and the elevated type (16.6%, 24 of 145 cases) (Chi square analysis, p < 0.05) in the incidence of Paneth cells. Paneth cells were seen more frequently in adenocarcinoma (45.8%, 11 of 24 cases) than in tubular adenoma (16.8%, 27 of 161 cases), with a significant statistical difference (Chi square analysis, p < 0.01). According to location, in both tubular adenoma and adenocarcinoma, Paneth cells were more frequently observed in the proximal colon (tubular adenoma: p < 0.01, adenocarcinoma: p < 0.05, Chi square analysis).

Adenocarcinoma↗

New bronchodilators. II. 3H-imidazo[4,5-c]quinolin-4(5H)-ones.

A series of novel 3-substituted imidazo[4,5-c]quinolin-4(5H)-ones (2a-w) was prepared by the reaction of imidazo[4,5-c]quinolin-4(5H)-ones (6) with several electrophiles under basic conditions. The bronchodilatory activity of these compounds was evaluated on the basis of their protective effects against antigen-induced contraction (the Schultz-Dale reaction) of guinea-pig trachea (in vitro) and antigen inhalation-induced bronchospasm in passively sensitized guinea-pigs (in vivo). Although correlations between in vitro and in vivo activities were not clear, short alkyl chains such as the methyl and ethyl groups at the 3-position were important for potent activity, especially in vivo. Substituents at the 5-position were more tolerant of the activity than those at the 3-position. 5-Ethyl-3-methyl-3H-imidazo[4,5-c]quinolin-4(5H)-one (21) exhibits the most potent bronchodilatory activity among our tested compounds and is at least 5-fold more active than theophylline in vivo.

Animals↗

Ultrasonographic evaluation of neck and supraclavicular lymph nodes metastasized from lung cancer.

The significance of ultrasonography in the evaluation of metastasized neck and supraclavicular lymph nodes from lung cancer was analyzed. By ultrasonography, the lymph nodes could be visualized clearly as low-echogenic round areas, and the size could be precisely measured in three dimensions. It was also possible to diagnose whether or not the lymph node adhered to the surrounding tissues and to determine the relationship and the connection of supraclavicular lymph node and upper mediastinal lymph node. The therapeutic effect related to the size of the lymph node was evaluable by ultrasonography. Therefore, the ultrasonographic approach to the neck and supraclavicular lymph nodes metastasized from lung cancer is considered to be useful for clinical use.

Clavicle↗

[Clinical and CT-findings in hemiballismus].

We studied the correlation between clinical and CT-findings in 33 cases with hemiballismus. Of these 33 cases, 4 cases were examined by the authors and 29 cases were obtained from the literature. Cerebrovascular disease was present in 27 cases and the localization of the lesion was examined with CT. Of these 10 cases had lesions in the subthalamus, while 17 cases had lesions outside the subthalamus. In 6 cases, the location of the lesion was not recognized on CT. In cases with lesions outside the subthalamus, 11 cases had lesions in the putamen, 10 cases had lesions in the caudate. Therefore the lesion were largely located in the striatum. Typical hemiballismus was seen in 16 cases. In this group, 6 cases had lesions in the subthalamus, 5 cases had lesions in the putamen, and 3 cases had lesions in the caudate. Hemiballismus accompanied by hemichorea was seen in 17 cases. In this group, while 9 cases had hemichorea with ballismus, and 5 out of 9 cases had lesions in the caudate, 4 cases had lesions in the putamen. Thus, all lesions were located in the striatum. Eight out of 17 cases had hemiballismus with chorea. In these 8 cases, 4 cases had lesions in the subthalamus, these were 2 cases in the putamen, and 2 cases had lesions in the caudate. When all cases were examined in terms of clinical manifestations, 10 cases were considered to have lesions in the caudate and 7 out of 10 cases involved chorea. Ten cases had lesions in the subthalamus, while 6 out of 10 cases showed typical hemiballismus.(ABSTRACT TRUNCATED AT 250 WORDS)

Cerebral Infarction↗

[Lipopolysaccharide binding protein enhances intratracheally administrated lipopolysaccharide-induced acute lung inflammation via a CD14 receptor].

We examined the role of lipopolysaccharide binding protein (LBP) in the airspace and the CD14 receptor on alveolar macrophages in TNF alpha production and neutrophil (PMN) sequestration in lungs induced by intratracheal injection of lipopolysaccharide (LPS). LPS alone (Salmonella minnesota wild-type; 20 ng) or LPS + LBP complex [LPS (20 ng) + rabbit LBP (500 ng); preincubated for 30 min at 37 degrees C] was injected intratracheally into isolated rabbit lungs perfused with lactate-Ringer-albumin solution. Human PMN (5 x 10(7)) were added to the perfusate after 2 hr perfusion. Samples of lung perfusate were collected every 30 min for 180 min, after which bronchoalveolar lavage (BAL) was also performed. TNF alpha concentration in the perfusate and BAL fluid were determined using a bioassay with L-929 fibroblasts. PMN accumulation in the lung was determined by myeloperoxidase assay of the lung homogenate. LPS alone did not significantly increase TNF alpha production or PMN accumulation in lungs, whereas LPS/LBP complex increased TNF alpha concentration in the perfusate and PMN accumulation. Intratracheal injection of anti-CD14 antibody (40 micrograms) with LPS/LBP complex prevented TNF alpha production and subsequent PMN sequestration. We conclude that LBP in the airspace enhances the effect of LPS on TNF alpha production via a CD14-dependent pathway, and this subsequently contributes to PMN sequestration in the lungs. Airspace accumulation of LBP secondary to increased vascular and epithelial permeability may play a critical role in the development of septic shock and lung injury by promoting TNF alpha production via a CD14-dependent mechanism.

Acute Disease↗

[A case of Machado-Joseph disease--cerebral blood flow and cerebral metabolic rate of oxygen].

A 51-year-old woman, with progressive gait disturbance and dysarthria, had been diagnosed as Menzel-type spinocerebellar degeneration. Later, she developed dystonic posture of upper limbs and bulging eyes. She was diagnosed as Machado-Joseph disease from neurological findings, which consisted of cerebellar signs, pyramidal tract signs and extrapyramidal tract signs and peripheral neuropathy. She died suddenly of unknown origin. Her illness lasted about 13 years. Neuropathological findings showed moderate neuronal loss with gliosis in the subthalamic nucleus, globus pallidus, substantia nigra, dentate nucleus, oculomotor and hypoglossal nucleus and anterior horn. Positron emission tomography (PET) using 15O steady state inhalation technique revealed reduction of cerebral blood flow and cerebral metabolic rate of oxygen in not only cerebellum but also cerebral cortex. These findings are different from typical PET findings of spinocerebellar degeneration.

Brain↗

[Evaluation of mediastinal lymph nodes by computed tomography in lung cancer].

It is important to evaluate hilar and mediastinal lymph node metastasis accurately, since the findings are used to determine the indications for therapies and to estimate the patient's prognosis. Computed tomography (CT) is a useful method for this purpose, but it is known that healthy people may also have lymphadenopathy up to 10 to 15 mm, and metastasis is sometimes observed in lymph nodes less than 10 mm in cases of adenocarcinoma. For this reason, it is necessary to establish an optimal criteria for measured values of lymph nodes on CT images. In this study, we compared the size of mediastinal lymph nodes on CT images and histological findings in 425 lymph nodes of 153 primary lung cancer patients resected in our hospital from 1984 to 1991. Criteria were expressed as possible criteria which can be obtained from ROC analysis with compatibility of sensitivity and specificity, and definite criteria which offer highest efficiency. We analyzed these two criteria by minor axis, major axis, their sum, and their product. As a result, minor axis offered the best criteria. The value of possible criteria was 8.7 mm (sensitivity: 73%, specificity: 70%) and definite criteria was 13 mm (efficiency: 88%) in 425 lymph nodes. Analyzed by histological type, the criteria of epidermoid carcinoma (possible criteria: 9.5 mm, definite criteria: 13 mm) were larger than those of adenocarcinoma (possible criteria: 8.3 mm, definite criteria: 11 mm). Analysed by anatomical region and histological type, the criteria of epidermoid carcinoma varied by with the location of lymph nodes, but those of adenocarcinoma were almost constant.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenocarcinoma↗

Oxidation of 1,1-diphenylhydrazine to N-nitrosodiphenylamine by superoxide radical in the eye.

By microsomes obtained from bovine ciliary body, 1,1-diphenylhydrazine was oxidized to N-nitrosodiphenylamine in the presence of NADPH. This reaction was stimulated by riboflavin which was recognized to be an electron carrier. The oxidizing activity by microsomes was markedly inhibited by superoxide dismutase, but not by SKF 525-A or carbon monoxide. Similarly, the oxidation of 1,1-diphenylhydrazine to its corresponding nitrosamine occurred in varying degrees when the hydrazine derivative was exposed to visible light in the presence of photosensitizers such as riboflavin, flavin adenine dinucleotide, flavin mononucleotide, lumiflavin, lumichrome, NAD+, NADH, NADP+, or NADPH. The photochemical oxidation was inhibited by active oxygen-scavengers such as superoxide dismutase, L-ascorbic acid or alpha-tocopherol. The superoxide radical involved in the photochemical reaction was determined by measuring the oxidation of epinephrine to adrenochrome. The oxidation of epinephrine was well correlated to that of 1,1-diphenylhydrazine. Thus, the present study provided evidence that the superoxide radical is responsible for the oxidation of a hydrazine derivative to a corresponding nitrosamine by ocular tissue microsomes and by photosensitizers.

Adrenochrome↗

[Late results of coronary artery bypass grafting with the internal thoracic artery].

Between November 1981 and December 1991, 755 patients underwent isolated coronary artery bypass grafting. We compared postoperative events, graft patency and survival rates of the patients who received at least one internal thoracic artery graft (n = 517) with those of the patients who had only saphenous vein bypass grafts (n = 238). No significant difference was found between the 2 groups in patient's age at the operation, female ratio and the incidence of emergency operation. The operative mortality was not significantly different in either group. Graft patency was better for internal thoracic artery grafts than for SVG (ITA grafts 97.1%, SVG 85.6% p less than 0.0001). Graft-LAD patency rate was also better for ITA grafts than for SVG (ITA grafts 97.7%, SVG 86.8%, p less than 0.0001). The incidence of late cardiac events (late cardiac death, reoperation, myocardial infarction) is lower in patients with ITA. Furthermore, patients who received ITA grafts had a better survival rate at 8 years (91.1% versus 85.3%, p = 0.048) than those who had vein bypass grafts alone. We conclude that the use of ITA grafts enhances the long-term benefits including long-term survival rate. This is the first observation in Japanese population.

Adult↗

[Left ventricular performance after patch reconstruction of the left ventricular wall for postinfarction left ventricular aneurysms].

Left ventricular performance in patients with a left ventricular aneurysm (LVA) treated with patch reconstruction is largely unknown. This study consisted of 15 patients, 14 men and 1 woman, with the average age of 59 +/- 8.5 years. The resected area of LVA was 40 +/- 27 cm2. The area of the woven Dacron patch used for reconstruction was 57 +/- 19% of the resected area including the sewing rim. The EF (Ejection Fraction, 1/3FF (Filling Fraction) and PFR (Peak Filling Rate) were calculated by 99mTc equilibrium cardiac pool scintigraphic images. The A/R ratio (peak velocity during atrial kick phase/peak velocity during the rapid filling phase) was measured using Doppler echocardiography, at the mitral orifice level. These parameters were determined before and 1 to 2 months after the operation. The time course was followed for A/R ratios. The preoperative resting global EF was 0.28 +/- 0.14 (0.44 +/- 0.13 for the contractile area) and the EF during exercise was 0.31 +/- 0.14. Resting and exercise EFs improved significantly (p < 0.01) to 0.40 +/- 0.11 and 0.43 +/- 0.10 postoperatively. The 1/3FF (%) and PFR (/sec) were low before operation (1/3FF, 11.3 +/- 8.3; PFR, 1.2 +/- 0.47). Postoperatively, the 1/3FF rose to 14.8 +/- 9.3 and the PFR showed a significant (p < 0.05) increase to 1.6 +/- 0.6. The A/R ratio significantly (p < 0.05) improved from preoperative 1.76 +/- 0.46 to 0.95 +/- 0.11 on the 3rd postoperative day. This improvement was maintained until the late postoperative period, with a value of 1.14 +/- 0.29 at month 16.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗