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Biomedical subjects

K Chiba

Publications and source records attributed to K Chiba.

At least 325 records · Page 18Linked to original sources
PubMed1989

Cefotiam disposition in markedly obese athlete patients, Japanese sumo wrestlers.

Markedly obese athletes like Japanese sumo wrestlers may frequently suffer various traumas which result in the prophylaxis or treatment of posttraumatic infection with antibiotics. However, appropriate dosage regimens in this group of patients have not been fully known for many antibiotics. Therefore, we studied the kinetic disposition of cefotiam, a parenteral, broad-spectrum cephalosporin with activity against gram-positive and -negative bacteria, after an intravenous dose (2 g) infused over 30 min into 15 sumo wrestler patients with an excess body weight (130 to 220% of ideal body weight) and 10 control patients with a normal weight (90 to 102% of ideal body weight). Mean (+/- standard deviation) clearance and steady-state volume of distribution were significantly greater in the sumo wrestler than in the control group (38.3 +/- 9.4 versus 23.5 +/- 6.0 liters/h, P less than 0.001, and 30.2 +/- 8.0 versus 17.9 +/- 6.1 liters, P less than 0.001). Mean elimination half-life was slightly but significantly longer in the sumo wrestler than in the control group (0.91 +/- 0.14 versus 0.74 +/- 0.20 h, P less than 0.05). However, mean residence time did not differ between the two groups (0.79 +/- 0.10 versus 0.75 +/- 0.14 h). The statistical differences in clearance and volume of distribution between the two groups disappeared when these kinetic parameters were corrected for body surface area, but not for total body weight or ideal body weight. The results suggest that the dosage calculation of cefotiam, a hydrophilic antibiotic, should be made on the basis of body surface area in morbidly obese athlete or sumo wrestler patients. However, whether this recommendation should extend to other nonathlete obese subjects remains to be determined.

Adult↗
PubMed1989

Rat epidermal growth factors: purification and tissue content.

Rat epidermal growth factor (rEGF) was isolated from the submaxillary gland of male rat by reversed phase high performance liquid chromatography and ion exchange chromatography. The binding of purified rEGF to human carcinoma cells (A-431) and its tritiated thymidine uptake on rat epidermal fibroblast cells (FR) were almost the same as those of purified commercially available mouse EGF (mEGF). Antisera to rEGF was raised in rabbits and a radioimmunoassay (RIA) system was established. The assay range of the RIA was about 1.0 to 100 ng/ml. The within assay coefficients of variation were 5 to 10%, while the between assay coefficients of variation were 5 to 13%. The tissue content of rEGF of male rats (10 weeks old) was examined. As a result, the submaxillary gland was found to contain a very high concentration of rEGF (214 micrograms/g wet tissue) as predicted, and digestive tissues, stomach, intestine and duodenum contained 2.49, 3.57, 9.44 ng/g wet tissue, respectively. The amounts in prostate and seminal vesicle were relatively high, being 65.6 and 2,268 ng/g wet tissue, respectively. The amount in the submaxillary gland increased markedly after 7 weeks of age. These results suggest that EGF is an important factor in gonadal function.

Aging↗
PubMed1989

[Distribution pattern of density in lumbar vertebra studied with computed tomography: a study of histogram plot].

The bone mineral status of the cancellous bone in the lumbar vertebrae was evaluated by analysing density histograms and measuring the mean density by computed tomography. The results obtained were as follows: (a) the distribution pattern of bone density in lumbar vertebrae revealed a normal distribution. (b) high correlation coefficients between peak density (r = -0.79) or mean density (r = -0.77) and age was obtained in males, whereas peak densities in females were maintained well at ages younger than 50 years and peak densities abruptly decreased after 50 years of age. Osteoporotic vertebrae, in which multiple osteosclerotic changes were observed, had several peak densities and did not show normal density distribution pattern. These results indicated that our methods combining analysis of density histograms and measurement of mean density are useful to evaluate the bone mineral status.

Absorptiometry, Photon↗
PubMed1989

[A new computed tomography method for quantitative analysis of abdominal aortic atherosclerosis].

Clinical evaluation of aortic atherosclerosis has been most commonly performed by visual analysis of aortic calcification on conventional radiographs or X-ray CT. However, precise evaluation of the degree of calcification or mild changes with increasing age can be difficult by these methods of visual analysis. A new quantitative method of evaluating the abdominal aortic atherosclerosis using CT is reported. Target CT scans of the abdominal aorta were performed at the level of the 1st, 3rd and 4th lumbar vertebrae. Two circular regions of interest (ROI) were selected along the outer margin and inner margin of the abdominal aortic wall on CT images, since it was difficult to precisely trace the aortic wall. Histograms of CT value for each pixel were made from two ROIs. A histogram at the ROI of the outer margin was depicted using class values over the maximum CT value in histogram at the ROI of inner margin which indicated flowing blood. A sum of products of the value in each class by the number in that class was divided by the aortic diameter. The value thus obtained was defined as the atherosclerotic index (S.I.). Forty-five cases were studied with this method. Six cases were excluded because of artifacts. The remaining 39 cases (16 males, 23 females) were analyzed. S.I. increased with aging and was higher in men than in women. However, it increased more rapidly in women (8.68/year) than in men (2.73/year). Because this new method employed the CT value, it is more objectively quantitative than previous methods of visual analysis in evaluating abdominal aortic atherosclerosis.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1989

[Evaluation of gallbladder emptying in patients with chronic liver disease by 99mTc-EHIDA hepatobiliary scintigraphy].

Gallbladder emptying after intramuscular injection of cerulein was investigated by 99mTc-EHIDA hepatobiliary scintigraphy in 23 patients with biliary disease, 55 patients with chronic liver disease, and 21 normal controls. The mean gallbladder ejection fraction in patients with gallstones and liver cirrhosis was significantly reduced compared with normal controls. (gallstones: 56.3 +/- 21.3%, LC with gallstones: 50.8 +/- 29.6%, LC without gallstones: 55.9 +/- 26.7%, vs. normal controls: 74.4 +/- 12.9%, p less than 0.01). The mechanism for sluggish gallbladder emptying in liver cirrhosis is unknown, however impaired emptying with bile stasis provides a potential pathophysiologic basis for the high frequency of pigment stones.

Adult↗
PubMed1989

[Multiple ureteral diverticula: a case report].

A 73-year-old male was admitted to our hospital with the complaint of difficulty and frequency of urination. Needle biopsy of the prostate was done and microscopic examination revealed adenocarcinoma. Bone scintigram showed multiple bone metastasis and he was diagnosed as having prostatic carcinoma stage D2. Intravenous pyelography revealed multiple out-pouching lesion of mid left ureter and left mild hydronephrosis. Fosfestrol was given for prostatic carcinoma and no treatment was given for multiple ureteral diverticula. Sixteen cases of multiple ureteral diverticula from Japan were collected and discussed.

Adenocarcinoma↗
PubMed1989

Nipradilol, a beta-adrenoceptor antagonist having a vasodilatory action, attenuates myocardial acidosis induced by coronary artery occlusion in dogs.

In dogs anesthetized with pentobarbital, the anterior descending coronary artery (LAD) was partially occluded to reduce LAD flow to about half of the original flow (partial occlusion). Myocardial pH (MpH) was measured by the use of a micro glass pH electrode. MpH decreased from 7.5-7.63 to 6.82-6.86 30 min after partial occlusion of the LAD. Nipradilol (0.3 mg/kg) was injected intravenously 30 min after partial occlusion, which continued for a further 60 min after nipradilol injection. Nipradilol decreased blood pressure and heart rate, and significantly increased myocardial pH which had been decreased by partial occlusion, within 60 min after injection. Nipradilol-induced restoration of the myocardial [H+] (calculated from the pH data), that had been increased by partial occlusion, was 48.5%. Bradycardia induced by nipradilol was not a determinant factor in the pH effect of nipradilol, because even in the paced heart, nipradilol restored the myocardial [H+] that had been increased by partial occlusion. These results indicate that nipradilol attenuates ischemia-induced myocardial acidosis, suggesting the favorable effect of nipradilol on ischemic myocardium. The favorable effect of nipradilol may be due to the beta-adrenoceptor antagonistic effect rather than the vasodilating effect.

Acidosis↗
PubMed1989

[A susceptible factor to acquire parkinsonism: sparteine oxidation polymorphism].

Recently, we found that hepatic oxidative enzyme(s) functions to attenuate neurotoxic effects of MPTP by converting the agent to its inactive metabolite(s) and reducing the amount of MPTP reaching at the brain in mice. Since the factors affecting the neurotoxic effects of MPTP may be related to the cause of spontaneous Parkinsonism, we studied the oxidation polymorphism of sparteine in 49 patients with parkinsonism. Although no poor metabolizer was found in patients with Parkinsonism, mean metabolic ratio of the patients was significantly (P less than 0.05) greater than that of healthy subjects. Furthermore, the value showed a significantly negative correlation (r = -0.327, p less than 0.05) with the onset of age. In addition, the percentage of the presumed heterozygotes (metabolic ratio less than 1.4) was tended to be greater in the patients with the onset of age, younger than 49 years (10/31) than in those with the onset of age, older than 50 years (2/18). These results suggest that decreased capacity of sparteine oxidation may be one of the susceptible factors to acquire Parkinsonism in human.

Age Factors↗
PubMed1989

[Psychogenic urinary retention: report of two cases].

Case 1 was a 24-year-old woman, with a broken heart who complained of urinary retention. Cystometry revealed a hypoactive bladder without detrusor contraction. Case 2 was a 30-year-old man, who thought that he had renal failure. Urodynamic study showed hypoactive bladder without detrusor contraction. External sphincter electromyograph revealed no evidense of detrusor sphincter dyssynergia. These 2 cases were treated by psychotherapy, administration of diazepam and bethanechole, and intermittent self catheterization. The Japanese literature on the psychogenic urinary retention is briefly discussed.

Adult↗
PubMed1989

[A case of retrocaval ureter in childhood].

We report a case of retrocaval ureter in a 14-year-old boy with the complaint of right flank pain. Intravenous pyelography and drip infusion pyelography showed right hydronephrosis and "inverted J" shaped ureter. A retrograde pyelography with venocavography revealed a typical retrocaval ureter, but abdominal CT scan did not show the "retrocaval segment". Ureterouretero-reanastomosis was performed and hydronephrosis was markedly improved. We analyzed 20 cases of retrocaval ureter in childhood.

Adolescent↗
PubMed1989

Thermal cycling effects on the stored rabbit cornea.

Specular microscopy has proven itself a useful tool for evaluation of donor corneas. In many eye banks, corneas are stored at 4 degree C and warmed to room temperature for specular microscopic evaluation. On occasion it would be desirable to put the cornea back into storage provided there were no detrimental effects of the recooling and subsequent rewarming. The effects of repeated cooling and rewarming (thermal cycling) on the corneal endothelium were determined using rabbit corneas stored in M-K medium at 4 degree C. Some corneas were left in the refrigerator for a 7-day storage interval while others were removed daily, warmed to room temperature, evaluated morphologically and biochemically with the specular microscope and the redox fluorometer, respectively, and then placed back in the refrigerator. At the end of the 7-day storage period there were no statistically significant differences in either the biochemical signals or the specular appearance between thermally cycled corneas and corneas that were continuously stored at 4 degrees C for the same period of time. Repeated warming, specular microscopic observation, and cooling of the cornea appear not to be detrimental to the corneal endothelium.

Animals↗
PubMed1988

Noninvasive metabolic analysis of preserved rabbit cornea.

With the method of corneal redox fluorometry, the autofluorescence of reduced pyridine nucleotides (PN) and oxidized flavoproteins (Fp) in rabbit corneal endothelium was measured as a function of storage time in McCarey-Kaufman (MK) medium and K-Sol medium. Measurements were started immediately after preparation of the corneal button, and the corneas were followed up for up to three weeks of storage. In both media, the PN/Fp ratio of the endothelium initially increased slightly in the first or second day and then began to decrease toward a level lower than baseline. This initial increase is possibly a result of an adaptive mechanism. The PN/Fp ratio maintained itself in the range of baseline values up to one week in MK medium but not in K-Sol medium. With scanning electron microscopy, the surface of the membrane and cell border were maintained for a three-week preservation period, and no apparent differences were found between the corneas stored in the two media. With transmission electron microscopy, the intracellular organelles appeared almost normal through one week of preservation in corneas stored in either media. During weeks 2 and 3, however, intracellular edema with increased endothelial thickness became prominent in the corneas stored in both media. Although no visual difference in the morphological features of the endothelium was apparent between corneas stored in either medium, computer-assisted morphometric analysis showed a statistically significant increase in the coefficient of variation of mean cell area for the corneas preserved in K-Sol medium but not for those preserved in MK medium.

Animals↗
PubMed1988

Bilateral anterior opercular syndrome: localizing value of SPECT and MRI.

Bilateral anterior opercular syndrome is clinically characterized by facio-pharyngo-glossomasticatory diplegia due to bilateral opercular lesions. Reported cases of the syndrome have been relatively rare probably because of difficulty in determining opercular damage on clinical symptoms alone. We report a case of this syndrome in whom bilateral opercular damage could be detected not by CT, but suggested by SPECT, and confirmed by MR imaging.

Aged↗
PubMed1988

Inhibitory effect of cilazaprilat on norepinephrine release induced by renal nerve stimulation in anesthetized dogs.

In pentobarbital-anesthetized dogs, the increase in the renal norepinephrine secretion rate elicited by renal nerve stimulation (1 Hz) during infusion of angiotensin I (15 ng/kg/min) was partially but significantly inhibited (by 21-37%) after dosing with cilazaprilat (0.1 mg/kg), an angiotensin converting enzyme inhibitor, accompanied by a decrease in the renal venous plasma norepinephrine concentration. These results may suggest that cilazaprilat exerts at least a part of its hypotensive effect through decreasing the facilitatory action of endogenous angiotensin II on adrenergic transmission.

Angiotensin I↗
PubMed1988

Further analysis of sparteine oxidation in a Japanese population and comparison with data observed in different ethnic populations.

1. Data on the oxidation polymorphism of sparteine (SP) studied in 84 unrelated Japanese subjects of whom two (2.4%) were classified as poor metabolizers (PMs) were re-evaluated. The data were obtained from 6-hour urinary excretion ratios of SP to 2- and 5-dehydrosparteines (DHS), after an oral dose of 100 mg of SP sulphate. 2. Urinary excretion of both SP and DHS correlated with the SP/DHS ratio (rs = 0.862 and -0.756, respectively, P less than 0.001). In addition, urinary excretion of 2-DHS, 5-DHS or total DHS discriminated between PMs and extensive metabolizers (EMs). There was also a highly significant correlation (rs = 0.669, P less than 0.001) between the urinary excretion of 2- and 5-DHS. 3. These re-evaluated results on the oxidation polymorphism of SP indicate that 2- and 5-DHS formation from SP shares a common metabolic pathway (presumably via the same P-450 isozyme), and that the SP/DHS ratio, conventionally used as a discriminating index between PMs and EMs, quantitatively reflects the capacity of 2- and 5-DHS formation. 4. The benefit of using a shorter (6 h) collection period for assessing the individual oxidation phenotype of SP and inter-ethnic comparison of SP oxidation is also discussed.

Adult↗
PubMed1988

Corneal endothelial changes following minor trauma.

The healing processes that occur when corneal endothelial cells are subjected to only mild trauma are not known. To study these processes we have developed a system that enables only a few endothelial cells to be traumatized or destroyed under continuous specular microscopic observation in vitro. Experiments in which a small group of cells were traumatized by gentle wounding with a microglass tip produced an immediate and distinct dark area having the same size as the tip. Using this method we have produced and observed two types of wound by controlling the force of wounding. The first type of wound, produced by a gentle touch, recovered within 1 hr. The second type of wound, produced by moderate touch, took about 24 hr to recover completely from the trauma. In the second type of wound, we observed migration, elongation, coalescence and mitosis during the healing process. Histological examination revealed that in the first type of wound, the cells remained intact with no apparent damage seen by vital staining and light microscopy. For the second type of wound, the cells were completely missing although there was no apparent damage to Descemet's membrane.

Animals↗