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Biomedical subjects

E Koh

Publications and source records attributed to E Koh.

At least 127 records · Page 7Linked to original sources
PubMed1988

[A case of fibrous pseudotumor of the spermatic cord].

A case of fibrous pseudotumor of the left spermatic cord is reported. The patient was a 4-year-old boy with the complaint of swelling and pain of the left scrotal contents. An intrascrotal tumor was suspected and surgical exploration was carried out. A small tumor was resected and histological examination revealed fibrous pseudotumor. This tumor was not a true neoplasm, but was due to an inflammatory disease. The clinical and histological findings of the tumor are discussed.

Child, Preschool↗
PubMed1988

[Endocrinological profile of human spermatogenic impairment--evaluation of function of Leydig and Sertoli cells in vivo or in vitro studies].

In vivo and in vitro studies were performed to determine the function of Leydig and Sertoli cells of the human testis with various degrees of spermatogenic impairment. The increases in basal and peak serum levels of luteinizing hormone (LH) and follicle stimulating hormone (FSH) after LH-RH administration correlated with the degree of impairment of spermatogenesis, and the basal peripheral blood levels of testosterone and that after human chorionic gonadotropin (hCG) administration for patients with moderate or severe impairment were significantly lower than the values for those with mild impairment. The concentration of testosterone in the internal spermatic vein of varicocele patients with or without hCG treatment did not differ between in mild and moderate impairment. In studies on cultured Sertoli cells, the production rate of plasminogen activator in patients with severe impairment was significantly lower than that in patients with moderate or mild impairment. The decrease in testicular high-affinity binding site for FSH correlated with the degree of hypospermatogenesis found in idiopathic male infertility, but, on the contrary, the hCG (LH) receptors showed no correlation with the degree of impairment of spermatogenesis. In the investigation of the relationship between testicular FSH receptors and the effectiveness of human menopausal gonadotropin (hMG)-hCG treatment on idiopathic male infertility, the presence or absence of testicular FSH receptors predicted the responsiveness to the treatment.

Chorionic Gonadotropin↗
PubMed1988

Relationship between the occurrence of late potential on the body surface ECG and cardiac performance in myocardial infarction.

Comparative evaluations of the percent of the perimetric circumference of infarction and cardiac performance for the occurrence of late potential were performed in 12 normal subjects and 22 patients with old myocardial infarction (MI). All patients were in normal sinus rhythm without bundle branch block. Bipolar X, Y, and Z leads were signal-averaged using a bandpass filter with a low-cut frequency of 100 Hz and a high-cut frequency of 300 Hz. The filtered signals for the three leads were displayed and combined into a vector magnitude, square root of X2 + Y2 + Z2. The percent ratio of the root mean square voltage in the last 40 msec of the QRS complex was calculated against that of the total filtered QRS (%RMS40). The value of the standard deviation (SD) in the phase distribution was obtained by the Fourier analysis of multi-gated blood pool images. Significant differences were observed among MI with late potential, MI without it and the normal subjects for %RMS 40 (5.7 +- 2.8% vs 26.9 +- 8.1, 37.5 +- 10.8%). Left ventricular ejection fraction was lower in MI with late potential (19.7 +- 7%) compared to that of MI without it (33 +- 18%) and the normal subjects (60 +- 4%); the value of SD was higher in MI with late potential (64 +- 21 degrees), compared to that of MI without it (43 +- 20 degrees) and the normal subjects (9 +- 4 degrees). These findings showed that the percent ratio of the last 40 msec RMS voltage (%RMS 40) was found to discriminate effectively among MI with and without late potential and normal subjects. It was suggested that the amount and structure of the infarcts may be important factors in the occurrence of late potential.

Adult↗
PubMed1988

[Down-regulation of rat and human testicular hCG receptors by hCG].

Changes in rat and human testicular human chorionic gonadotropin (hCG) binding sites induced by hCG were estimated in vivo and in vitro. After a single administration of hCG, the specific hCG binding sites were significantly reduced for 7 and 5 days in rat and human testes, respectively. However, hCG binding sites had recovered to pretreatment values by the 14th day after the administration. Occupied hCG binding sites measured in both rat and human testes accounted for about half of the reduced binding sites on the day after administration of hCG, but thereafter the number of sites occupied was not correlated with the reduction of the binding induced a dose-related significant loss of the specific hCG binding sites for 7 and 5 days in rat and human testes, respectively. Thereafter, the number of binding sites gradually increased. These patterns of change in hCG binding sites in vitro were similar to those in vivo. These findings suggest that the reduction in hCG binding sites in rat and human testes by hCG is due not only to occupancy but also down-regulation of the binding sites. In conclusion, the present testicular organ culture method is useful to study hormonal regulation of testicular function, especially in human testes.

Adult↗
PubMed1987

[Radioimmunoassay of the calcitonin gene-related peptide and its measurement in the plasma of patients with medullary thyroid carcinoma and in the cerebrospinal fluid of normal subjects].

Calcitonin gene-related peptide (CGRP) is a peptide recently found by recombinant DNA and molecular biological techniques in rat medullary thyroid carcinoma cells, but its physiological role(s) is unknown. We established a radioimmunoassay for this peptide using human-CGRP (1-37) as a standard, 125I-human-CGRP (1-37) as a tracer, and anti-rat-CGRP (28-37) serum as a first antibody. Aprotinin, an inhibitor of proteolytic enzymes in the plasma, was also added to the assay system, because in its absence the tracer was degraded during incubation with plasma samples. The sensitivity of the assay was 60 pg/ml and the intra- and inter-assay coefficients of variation were 6.0% and 8.5%, respectively. The recovery was 105 +/- 17%. The plasma levels of CGRP in 17 normal subjects (mean +/- S.D. age, 45 +/- 12 years) were all below 300 pg/ml, the mean level being 132 +/- 77 pg/ml. The levels were also below 300 pg/ml in 20 of 21 patients with medullary thyroid carcinoma, but one patient who had a high level of 942 pg/ml (mean value, 142 +/- 193 pg/ml). There was no significant difference between the mean plasma levels of CGRP in normal subjects and patients with medullary thyroid carcinoma. The mean plasma levels of CGRP in 5 patients with medullary thyroid carcinoma did not increase in response to infusion of either 4.3 mg/kg of calcium in 10 minutes or 4 micrograms/kg of tetragastrin in 5 minutes, although the plasma levels of calcitonin in these patients increased markedly during these provocation tests. The levels of CGRP in the cerebrospinal fluid of 16 normal volunteers were all below the detectable limit (less than 60 pg/ml). These findings suggest that fewer patients with medullary thyroid carcinoma than reported previously have high plasma levels of CGRP, either in the basal state or in response to calcium or gastrin, and that the levels of CGRP in the cerebrospinal fluid of normal subjects are very low.

Adolescent↗
PubMed1987

Effects of nitrates and calcium channel blockers on Ca2+-ATPase in the microsomal fraction of porcine coronary artery smooth muscle cells.

The effects of the antianginal drugs nitroglycerin, nicorandil, diltiazem, verapamil and nicardipine on the activity of calcium-stimulated magnesium-dependent ATPase (Ca2+-ATPase) were investigated in the microsomal fraction from porcine coronary artery smooth muscle cells. Two discrete Ca2+-dependent ATPase components were observed: [1] a high affinity component, which was a specific Ca2+-ATPase, [with a half saturation constant for Ca2+ (Km) of 0.44 microM, and maximum velocity (Vmax) of 124.3 pmol of phosphate (Pi) released/micrograms of protein/30 min]: [2] a low affinity component in which Ca2+ could be replaced by Mg2+ without loss of its activity. Nitroglycerin and nicorandil (1 microM and 10 microM) both stimulated the activity of the Ca2+-ATPase significantly [142 +/- 12 (mean +/- standard error), and 137 +/- 10% of the control with nitroglycerin, and 152 +/- 17 and 135 +/- 20% with nicorandil] at a Ca2+ concentration of 0.3 microM. Diltiazem, verapamil and nicardipine did not cause significant stimulation. Nitroglycerin and nicorandil (1 microM), significantly decreased the Km for Ca2+ from the control value of 0.44 +/- 0.06 microM to 0.26 +/- 0.03 and 0.22 +/- 0.03 microM, respectively. Nitroglycerin and nicorandil may dilate coronary arteries by stimulating this Ca2+ extrusion pump enzyme through reduction of intracellular Ca2+ in smooth muscle cells.

Animals↗
PubMed1987

Bilateral ureteral stricture due to ureteral fibrosis. Case report.

A case of bilateral ureteral fibrosis is reported. The patient, a 32-year-old man, was admitted as a result of acute renal failure. Ultrasonography showed bilateral hydronephrosis, so that in-dwelling percutaneous nephrostomy tubes were immediately inserted in the bilateral kidneys. Since retrograde and antegrade pyelograms revealed bilateral midureteral stricture, idiopathic retroperitoneal fibrosis at first suspected, but no mass in the retroperitoneal space was found by a computed tomogram. An exploratory laparotomy showed no fibrous mass in the retroperitoneal space either, but that the wall of the ureter was thickened. Biopsy of the ureter led to a histological diagnosis of fibrosis. Since evidence of inflammation such as elevation of the erythrocyte sedimentation rate and cross-reacting protein was found, 50 mg of prednisolone has been administered every other day, with the result that inflammation is now under control. This report deals with specific ureteral fibrosis related to idiopathic systemic fibrosis and collagen disease.

Adult↗
PubMed1987

Urethral metastasis from prostatic carcinoma as diagnosed by immunoperoxidase technique using prostate-specific antigen and prostate-specific acid phosphatase.

A rare case of urethral metastasis from prostatic adenocarcinoma is reported. Ordinary histological examination by hematoxylin and eosin staining could not determine whether the primary site was the prostate or the urethra. However, with an immunoperoxidase technique using prostate-specific acid phosphatase and prostate-specific antigen as markers for prostatic cells, we obtained a precise diagnosis of the primary sites. As a result, the patient could be successfully treated with hormonal therapy.

Acid Phosphatase↗
PubMed1987

Effect of nicorandil on the cytosolic free calcium concentration and microsomal (Ca2+ + Mg2+)-ATPase activity of vascular smooth muscle cells.

The influence of nicorandil, a potent antianginal drug, on cellular calcium in vascular smooth muscle cells (VSMC) was investigated by studying its effects on the cytosolic free calcium concentration ([Ca2+]i) and calcium-stimulated magnesium-dependent ATPase [(Ca2+ + Mg2+)-ATPase] in the cells. VSMC were prepared from rat aorta, and their [Ca2+]i level was determined by measuring the fluorescence of the free calcium indicator, fura 2. Preincubation with nicorandil for 5 min significantly decreased the rise in [Ca2+]i evoked by addition of either angiotensin II in control solution or prostaglandin F2 alpha, the latter in either the presence or absence of extracellular calcium. The effect of nicorandil on (Ca2+ + Mg2+)-ATPase activity in the microsomal fraction of porcine coronary artery smooth muscle, which is rich in plasma membranes and sarcoplasmic reticulum, was also investigated. Nicorandil at concentrations of 10(-6) and 10(-5) M increased the activity of (Ca2+ + Mg2+)-ATPase significantly at a free calcium concentration of 0.3 microM. At 10(-6) M, nicorandil significantly decreased the Kd for calcium of this enzyme without significantly changing its Vmax. These data suggest that nicorandil suppressed increase of [Ca2+]i, possibly by stimulating (Ca2+ + Mg2+)-ATPase, thereby inhibiting contraction of vascular smooth muscle.

Angiotensin II↗
PubMed1987

[Review of ureteral carcinoma as seen in mapping of the cystectomized bladder].

The incidence of unexpected ureteral carcinoma on mapping and recurrence of upper urinary tract urothelial cancer was examined in 160 patients who had undergone total cystectomy for vesical cancer and complete mapping of the specimens between May, 1978 and June, 1986 at our Center. Unexpected carcinoma in the ureteral stump was found in 5 patients (3.1%) and recurrent cancer in the upper urinary tract developed in 2 (1.3%) of the 160 patients. The incidence was higher in the recurrent bladder cancer cases, and also higher in patients with non-visible, high grade and superficial tumors of the bladders.

Aged↗
PubMed1987

Immunoreactive parathyroid hormones in the circulation and cerebrospinal fluid from patients with renal failure: possible restriction of parathyroid hormone by the blood-brain barrier.

Parathyroid hormone is reported to be a possible causal factor of abnormalities of electroencephalograms of patients with renal failure. In this study, the parathyroid hormone levels were compared in the circulation and cerebrospinal fluid of seven normal subjects and 22 patients with renal failure including those who showed abnormal electroencephalograms. The circulating levels of both C-terminal and N-terminal parathyroid hormone in the subjects studied showed a positive correlation (C-terminal, r = 0.58, P less than 0.01; N-terminal, r = 0.61, P less than 0.01) with the grade of abnormality of the electroencephalogram. However, the levels of C-terminal and N-terminal parathyroid hormone in the cerebrospinal fluid of both normal subjects and patients with renal failure were below the detectable limit (C-terminal, less than 0.1 ng/ml; N-terminal, less than 2.3 pg/ml). These data suggest that in patients with renal failure, the effect of parathyroid hormone on the central nervous system is mediated in some other way than via the cerebrospinal fluid.

Adult↗
PubMed1986

Effects of prostaglandins on the cytosolic free calcium concentration in vascular smooth muscle cells.

The effects of prostaglandin (PG) F2 alpha and 9,11-epithio-11,12-methanothromboxane A2 (STA2), a stable analogue of thromboxane A2, on the cytosolic free calcium concentration ([Ca2+]i) in vascular smooth muscle cells were studied with a new fluorescent Ca2+ indicator fura 2. PGF2 alpha and STA2, which are strong vasoconstrictors, caused rapid phasic and subsequent tonic increases in [Ca2+]i. PGF2 alpha caused dose-dependent elevation of [Ca2+]i not only in control solution but also in the calcium-free solution. A first stimulation with PGF2 alpha caused dose-dependent decrease in the response of [Ca2+]i to a second stimulation with PGF2 alpha. Pretreatment with 13-Azaprostanoic acid, a receptor level antagonist of thromboxane A2 inhibited the increase of [Ca2+]i induced by STA2. These results suggest that PGF2 alpha induces calcium mobilization followed by smooth muscle contraction through its specific receptors.

Angiotensin II↗