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Biomedical subjects

T Kitamura

Publications and source records attributed to T Kitamura.

At least 649 records · Page 36Linked to original sources
PubMed1987

Selective enlargement of the third ventricle found in chronic schizophrenia.

Selective enlargement of the third ventricle was observed when the area and the VBR (ventricle-brain ratio) were measured in 37 chronic schizophrenics (DSM-III criteria) as compared with 37 controls. However, the width or the width to IS (maximum inner skull width) ratio was not significantly different between the two groups. There was no correlation between any measure of the third ventricle and any of the clinical variables. Five patients had VBRs of the third ventricle that were larger than the mean + 2 SD of the control, but there was no significant difference between these five schizophrenics and the others in any of the clinical variables.

Adult↗
PubMed1987

Electron microscopic autoradiographic demonstration of inositol incorporation in the cochlea.

[3H]Inositol was perilymphatically perfused into the guinea pig cochlea and the sites of its incorporation were autoradiographically identified by electron microscope. In the organ of Corti, distinct areas of inositol incorporation were observed at sites enriched with cytoskeletal proteins. In addition, a wide range of cell organelles incorporated inositol. Cell membrane/subsurface cisterna complex of the outer hair cells and the cell membrane/microvilli complex incorporated inositol more avidly than did other cell membranes. In the stria vascularis, intermediate cells incorporated inositol more frequently than cells in other areas.

Animals↗
PubMed1987

Four serotypes of haemorrhagic fever with renal syndrome viruses identified by polyclonal and monoclonal antibodies.

Antigenic relationships among 20 strains of haemorrhagic fever with renal syndrome (HFRS) viruses isolated in Korea, China, U.S.S.R., Finland, Japan and U.S.A. were examined with rat immune sera, patient sera, eight monoclonal antibodies against the SR-11 strain and 10 monoclonal antibodies against the 76-118 strain. Antigen analyses by indirect immunofluorescent antibody and immune adherence haemagglutination tests using polyclonal and monoclonal antibodies demonstrated that HRFS viruses may be divided into four serotypes, i.e. Apodemus (Type 1), Rattus (Type 2), Clethrionomys (Type 3) and Microtus (Type 4). Further, it was demonstrated that Type 1 could be divided into three subtypes and Type 3 into two subtypes. The two sets of monoclonal antibodies were useful for identification of the antigenic types of viruses isolated from patients in endemic areas.

Animals↗
PubMed1987

Dendritic activities of spinal motoneurones in pigs and rabbits enhanced through chronic stimulation of a dorsal root.

1. The L6 or L7 dorsal root in 7-10-day-old pigs was chronically stimulated for 3 or 4 h a day for 4 days/week. The stimuli were 50 or 500 Hz pulse trains delivered at 0.5/s. The induced movements were limited to the hip and hind leg on the stimulated side without any sign of pain. There was evidence that not only the monosynaptic, but also polysynaptic pathways to the motoneurones were chronically stimulated. After 2-6 days of chronic stimulation, all pigs were studied in acute experiments either under pentobarbitone (Nembutal) anaesthesia or in the decerebrated state. Normal (unstimulated) 15-28-day-old pigs were also studied in acute experiments under similar conditions, as the controls. 2. In thirty-three out of fifty-six motoneurones of normal pigs there were all-or-none potentials of 2-6 ms duration and 1-5 mV amplitude. These have been named D-spikes. They occurred in response to tibial nerve and/or dorsal root stimulation and/or spontaneously. They could be abolished by injection of a hyperpolarizing current. These results show that D-spikes are different from any of the well-established all-or-none events of the motoneurone, i.e. the spikes of the axon, initial segment, soma and unitary excitatory post-synaptic potentials. Several kinds of D-spikes could exist in the same motoneurone, as judged from their wave forms and thresholds. This argues for the dendrites as the sites of origin for D-spikes, because only the dendrites can have multiple sites for spike generation. D-spikes were shown to summate to form a larger depolarization. 3. In pigs chronically stimulated with 500 Hz pulses seventy-five motoneurones were studied in acute experiments. In sixty-one motoneurones D-spikes were observed. This indicated that D-spike occurrence was enhanced in the chronically stimulated motoneurones as compared with controls. 4. Characteristic of the chronically stimulated motoneurone was the presence of a depolarization of all-or-none nature which was more than 10 ms in duration and 2-12 mV in amplitude. The depolarization is referred to as the D-wave. The D-wave was similar in properties to the D-spike described above, except that it was of longer duration. Consequently, it is assumed that the D-wave is summed D-spikes. D-waves were observed in nineteen motoneurones.(ABSTRACT TRUNCATED AT 400 WORDS)

Action Potentials↗
PubMed1987

Design of a new pulse duplicator system for prosthetic heart valves.

This paper discusses results of a computer simulation for designing a new pulse duplicator system for mechanical heart valves. The design objective of the system is to obtain a compact, efficient pulse duplicator system capable of accurately measuring the volume flow rate across a valve. The volume flow rate is determined as the derivative of the volume displacement of an actuator piston which directly drives the fluid. The system does not need any circulatory loop, since the piston is controlled on-line to follow command signals representing an aortic impedance. The results of the computer simulation show: the designed PI-controllers of the actuator can precisely control valve motion to follow given command signals, the eigenvalues of the controllers have to be carefully chosen to prevent unstable behaviors of a valve in diastole, and the dimensions of the actuator is optimized by minimizing a cost function of the total efficiency of the system.

Biomechanical Phenomena↗
PubMed1987

Carcinoma of the renal pelvis and bladder associated with sarcoidosis: a case report.

A 75-year-old woman with transitional cell carcinoma of the renal pelvis was revealed to have sarcoid granulomas within the kidney as well as in the renal pedicle lymph nodes. Furthermore, noncaseating granulomas had been found in the pelvic lymph nodes in a histological study following previous total cystectomy for bladder cancer. The association of sarcoidosis with genitourinary malignancies is briefly discussed.

Aged↗
PubMed1987

Urethrectomy is harmful for preserving potency after radical cystectomy.

Twenty-three patients who underwent conventional total cystectomy were examined regarding postoperative potency. Two patients who were subjected to simple cystectomy and whose partial prostate and whole seminal vesicles were left showed full erection and normal ejaculation 1-2 months after surgery, thus giving 100% potency after simple cystectomy. In contrast, of 12 patients who underwent radical cystectomy alone, only 3 (25%) regained potency postoperatively, and the strength and duration of erection were not satisfactory for 1 of the 3 patients. Nine patients who received radical cystectomy and urethrectomy did not show signs of potency postoperatively. The sum total postoperative potency rate in the 21 patients subjected to radical cystectomy was 14.3% (3/21). The facts may indicate that urethrectomy is harmful for postoperative potency because damage of the cavernous nerves probably takes place during surgery. To avoid nerve damage, the urethra should be left intact during radical cystectomy employing the nerve-sparing technique developed by Walsh and Donker unless the posterior urethra is invaded by bladder carcinoma. In addition, it was demonstrated that pelvic irradiation might cause impotency as neither pelvic lymph node dissection nor cisplatin administration had any influence on postoperative potency.

Aged↗
PubMed1987

Possibility of elevated parathyroid function in patients with calcium-containing nephrolithiasis as compared with normal controls.

109 patients with calcium-containing nephrolithiasis and 10 normal controls underwent oral calcium load test. After thorough examination, 6 of the 109 patients were diagnosed as having primary hyperparathyroidism (PHPT) and the remainder as having normocalcemic nephrolithiasis without PHPT. Following the oral calcium load test, the latter were operationally divided into 3 groups - normocalciuric nephrolithiasis (NN), n = 78; absorptive hypercalciuria (AH), n = 10, and renal hypercalciuria (RH), n = 15 - according to the criteria reported by Pak et al. Before the oral calcium load test, nephrogenous adenosine 3',5'-monophosphate (NcAMP), urinary adenosine 3'-5'-monophosphate (urinary cAMP), and plasma immunoreactive parathyroid hormone (iPTH) were determined to evaluate parathyroid function. This function, as assessed by mean basal NcAMP in the NN, AH and RH groups as well as the PHPT group, was significantly increased as compared with that in the normal controls. Within the NcAMP-elevated 4 groups, the mean basal NcAMP was highest in the PHPT group followed by the RH, AH and NN groups. In view of the mean basal NcAMP, disregarding the PHPT group, the NN and AH groups seemed to be intermediate types between the normal controls and the RH groups. Similar, but less distinctive results were obtained in the determination of urinary cAMP and plasma iPTH. On the other hand, when leaving the PHPT group out, the mean basal urinary calcium creatinine ratio (Ca/Cr) was highest in the RH group followed by the AH and NN groups, and lowest in normal controls, suggesting that the NN and AH groups were intermediate between normal controls and the RH group. The mean basal urinary Ca/Cr ratio in the PHPT group was moderately elevated but not remarkable. Almost similar tendencies were observed in 24-hour urinary calcium excretions on a calcium-restricted diet. A weakly positive correlation (r = 0.232, p less than 0.05) between basal NcAMP and basal urinary Ca/Cr ratio was observed in accumulated cases of the NN, AH and RH groups, whereas a negative correlation (r = -0.664, p less than 0.05) was obtained in normal controls. It is concluded that a possible abnormal calcium metabolism is suggested in stone formers without PHPT. Additionally, it is speculated that 'relative hypercalciuria' in NN and hypercalciuria in AH and RH might be accounted for in a single line of a primary renal leak of calcium.

Adult↗
PubMed1987

[Almost complete disappearance of metastatic pulmonary tumor and reduction of the main hepatic mass in a case of hepatocellular carcinoma treated with UFT].

A 61-year-old female patient with a low density area indicated by abdominal CT was admitted to hospital. Several circular shadows 5-20-mm in diameter were visible on the chest photos. Primary hepatocellular carcinoma complicated by compensatory cirrhosis accompanying pulmonary metastasis was diagnosed from blood biochemistry tests, a high AFP value (390,000 ng/ml) and angiogram findings. After two months of daily administration of 400 mg of UFT as ftorafur, both reduced AFP (46,000 ng/ml) and a reduction of the primary nidus were observed; after four months, the circular shadows were almost completely eliminated on chest photos. Although UFT administration was discontinued (total FT dose 33.6g) due to jaundice, in the eight months after discontinuation no enlargement of the primary nidus, recurrent shadows on chest photos, or recurrent rise of AFP were observed. This case is considered to suggest the effectiveness of UFT against primary hepatocellular carcinoma with accompanying pulmonary metastasis.

Administration, Oral↗
PubMed1987

Binding of erythropoietin to CFU-E derived from fetal mouse liver cells.

The binding of recombinant erythropoietin (EPO) to fetal mouse liver cells (FMLC) was investigated using a radioiodinated derivative which retained full biological activity. FMLC were fractionated using a preformed Percoll density gradient. Using the fractionated FMLC, the ability to form CFU-E colonies in a semisolid culture was examined, and the binding of [125I]EPO was measured. The highest specific binding of [125I]EPO was observed in a fraction with a density between 1.062 and 1.076 g/ml. The same fraction showed the highest ability to form CFU-E-derived colonies. After suspension culture of FMLC with EPO for 2 days, differentiated erythroid cells with higher density markedly increased. The specific binding of [125I]EPO to these cells almost disappeared with differentiation. Scatchard analysis with cells of the CFU-E-enriched fraction showed a nonlinear curve, suggesting the existence of two classes of binding sites. One binding site was high-affinity (Kd1 = 0.41 nM), and the other low-affinity (Kd2 = 3.13 nM). These results suggest that the expression of EPO receptors on the erythroid cells is highest in CFU-E.

Animals↗
PubMed1987

[Ultrasonographic diagnosis of intracystic breast tumors].

Ultrasonography was performed on 1805 patients with breast diseases during the past 3 years and 20 (1.1%) intracystic tumors were detected. Among 20 intracystic tumors, 14 were finally diagnosed as benign and 6 as malignant. None of the 6 malignant lesions was judged as exclusively malignant and only 3 were considered as suspiciously malignant by ultrasonography. Ultrasonography is effective in making the location of intracystic tumors clear but not suitable for distinguishing malignant tumor from those that are benign. On the contrary, among the 6 malignant lesions, 5 were diagnosed as malignant and 1 as suspiciously malignant by aspiration cytology. Therefore, a combined examination of ultrasonography and aspiration cytology is a useful method for preoperative diagnosis of intracystic breast tumors.

Adenocarcinoma↗
PubMed1987

Liquid chromatography and radioimmunoassay compared for determination of cortisol and corticosterone in plasma after a dexamethasone suppression test.

We developed sensitive, specific "high-performance" liquid chromatography (HPLC) for determining suppressed cortisol and corticosterone in human plasma and compared its efficacy with that of conventional radioimmunoassay (RIA) at concentrations in the nanogram per liter range. Steroids from a 0.5-mL aliquot of plasma were extracted by rapid-flow fractionation, with diethyl ether as mobile-phase solvent, diatomaceous earth granules as stationary-support material. Analytical recovery of the steroids approached 100%. Concentrations in plasma were determined from peak-height ratio calibration (dexamethasone internal standard). The analytical column contained silica gel and the solvent system was water/methanol/dichloromethane/n-hexane (0.1/3/30/66.9 by vol). We could measure the steroids before and 20 h after oral administration of 0.5 mg of dexamethasone. The detection limit was 300 ng per liter of plasma for corticosterone, 500 ng/L for cortisol, with CVs of less than 4%. Determining corticosterone after administration of dexamethasone, in four of 20 such samples we could determine concentrations greater than 300 ng/L; the others contained corticosterone between 100 and 300 ng/L, but these values could not be certified analytically. Mean concentrations of these hormones as determined by RIA substantially exceeded those by HPLC. Some cross reactions in RIA could not be considered negligible in spite of pre-column treatment of the extracts.

Adult↗