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Biomedical subjects

E Koh

Publications and source records attributed to E Koh.

At least 109 records · Page 6Linked to original sources
PubMed1989

[Temperature influence on human testicular function--optimal temperature for testicular macromolecular synthesis].

Precursor incorporations into DNA, RNA and protein fractions of the human testicular tissue were examined at 28 degrees C-43 degrees C in vitro to study the optimal temperature for DNA, RNA and protein synthesis in the human testis. The results suggest that the DNA synthesis shows delicate temperature sensitivity and is at a maximum at 31 degrees C, whereas the RNA and protein syntheses are at a maximum at 37 degrees C-40 degrees C. The slight variation of the testicular temperature may cause spermatogenic dysfunction because of delicate temperature sensitivity of the testicular DNA synthesis.

Culture Techniques↗
PubMed1989

Low density lipoprotein and apoprotein B induce increases in inositol trisphosphate and cytosolic free Ca2+ via pertussis toxin-sensitive GTP-binding protein in vascular smooth muscle cells.

Low density lipoprotein (LDL), a major cholesterol-carrying lipoprotein in the plasma, binds to its receptor through apoprotein B (Apo-B). The addition of LDL and Apo-B induced rapid (5 s), but transient increase in the inositol 1,4,5-trisphosphate (Ins-1,4,5-P3) level with K0.5 values of 1.1 and 0.07 microgram/ml, accompanied by increases of cytosolic free Ca2+ concentration [( Ca2+]i), in vascular smooth muscle cells (VSMC). The increases by LDL and Apo-B were both reduced by pretreatment of the VSMC with pertussis toxin. The early change in Ins-1,4,5-P3 involving a GTP-binding protein may function as an initial signal for the action of LDL in VSMC.

Animals↗
PubMed1989

Comparison of the inhibitions of proliferation of normal and psoriatic fibroblasts by 1 alpha,25-dihydroxyvitamin D3 and synthetic analogues of vitamin D3 with an oxygen atom in their side chain.

The inhibitory effects of 1 alpha,25-(OH)2D3 and synthetic oxa-derivatives of vitamin D3 on growth of normal and psoriatic fibroblasts in culture were compared. Proliferation of normal fibroblasts was strongly inhibited by these new compounds in the following order: 22-oxa-1 alpha,25-(OH)2D3 greater than 22-oxa-1 alpha-(OH)D3 greater than 1 alpha,25-(OH)2D3 greater than 20-oxa-1 alpha,25-(OH)2D3. 22-Oxa-1 alpha,25-(OH)2D3 was about 10-times more inhibitory than 1 alpha,25-(OH)2D3. Proliferation of psoriatic fibroblasts was not inhibited by 1 alpha,25-(OH)2D3 at concentrations of up to 10(-6) M, but was suppressed by 10(-8)-10(-6) M 22-oxa-1 alpha,25-(OH)2D3 and 10(-6) M 22-oxa-1 alpha-(OH)D3. These results suggest that oxa-derivatives of vitamin D3, especially 22-oxa-1 alpha,25-(OH)2D3, should be useful in further studies on the cause and treatment of psoriasis.

Calcitriol↗
PubMed1989

[A case of successful surgical treatment of straddling tricuspid valve associated with dextrocardia and VSD].

A case of straddling tricuspid valve associated with dextrocardia and VSD was presented. Closure of ventricular septal defect and tricuspid valve replacement were performed on this patient. Since the straddling septal leaflet of the tricuspid valve shared a posterior papillary muscle in the left ventricle with the posterior mitral leaflet, division of this papillary muscle was thought to induce papillary muscle dysfunction of both leaflet. Hence, the chordae of straddling tricuspid leaflet was detached from the shared papillary muscle and the ventricular septal defect was closed by a large pericardial patch. Because of peculiar anatomy of the conduction system in this situation, the junctional area of the inlet septum and tricuspid annulus was avoided from stitching in VSD closure. Suture through the tricuspid septal leaflet and pericardial patch for VSD were used for tricuspid valve replacement as well. The patient showed uneventful postoperative course without any conduction disturbance including the right bundle branch block.

Adult↗
PubMed1989

[A case of primary ureteral squamous cell carcinoma associated with calculus].

A case of primary squamous cell carcinoma of the ureter associated with ureteral calculus is presented. A 66-year-old woman was admitted to our hospital, with the chief complaint of macroscopic hematuria in October, 1985. A kidney-ureter-bladder X-ray and drip intravenous pyelography failed to reveal the calculus shadow clearly. However, computerized tomographic scan revealed the calculus shadow clearly adjacent to the ureteral tumor, and retrograde pyelography revealed the filling defect on a third lower portion of the left ureter. She was diagnosed with tumor of the ureter associated with the calculus. She underwent complete nephroureterectomy with excision of a periureteral cuff of the bladder. The tumor was diagnosed histologically as squamous cell carcinoma. Metastases and recurrence of tumor have never occurred on July, 1987. Forty-four cases of the primary ureteral squamous cell carcinoma could be collected in the Japanese literature. Moreover, we deal with this disease associated with the ureteral calculus.

Aged↗
PubMed1989

[Induction of plasma renin activity in human internal spermatic vein after treatment of HCG].

To investigate the secretion of renin from the Leydig cells of human testis, plasma renin activity (PRA) in left internal spermatic vein (ISV) and cubital vein (CV) was measured at the time of surgical repair of varicocele in 30 patients between 26 and 39 years old. Sixteen of them were given a single i.m. injection of hCG (10,000 iu) 4 days before operation, whereas the remaining fourteen were not treated. Although mean PRA levels of CV in treated and non-treated groups were similar (1.35 +/- 0.46 and 1.19 +/- 0.59 ng/ml/hr, respectively), mean PRA level of ISV in the treated group (2.85 +/- 1.15 ng/ml/hr) was significantly higher than that of CV in the same group (1.35 +/- 0.46 ng/ml/hr), and that of ISV in the non-treated group (1.39 +/- 0.67 ng/ml/hr) (both P less than 0.01). Mean testosterone level of the same ISV was clearly higher in the treated than in non-treated group (P less than 0.005). These data seem to suggest the secretion of hCG-induced renin from the human testis in vivo and the possibility of relation between androgens and secretion of renin.

Adult↗
PubMed1989

[A renal trauma: evaluation by dynamic CT].

To document the severity and degree of renal injury multiple studies may be necessary, including excretory urography, nephrotomography, arteriography and ultrasonographic examination. Even these extensive studies fail at times to provide sufficient information for treatment of the injury. However, the parenchymal injuries and extrarenal hematomas are depicted more accurately by computed tomography (CT). Moreover, dynamic CT can assess parenchymal enhancement during the capillary phase. Therefore, dynamic CT is useful in assessing the renal contusion and hematoma. In addition, it appears to be highly reliable and relatively noninvasive means of diagnosing renal trauma.

Humans↗
PubMed1989

[A case of chronic huge hematocele].

A case of chronic hematocele with calcification of the tunica vaginalis is reported. A 65-year-old male was referred to our clinic because of painless swelling of left scrotal contents. Examination revealed a heavy hard mass, 18 cm in diameter, in left scrotum, which started to enlarge 5 years earlier. He had a history of having been kicked by a cow about 10 years previously. The scrotum did not transmit light. Ultrasonography demonstrated hematocele with calcified shell. As it was impossible to exclude a testicular tumor completely, we performed high orchiectomy. Upon opening the mass an old hematocele was formed, which contained old brownish black clotted blood and a normal testis. The thick shell of the mass was found to be a calcified tunica vaginalis. Only 2 cases of chronic hematocele have been reported in the Japanese literature.

Aged↗
PubMed1988

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

There are reports that patients with renal failure have elevated circulating concentrations of parathyroid hormone (PTH), which is suspected to be a causal factor of the cerebral symptoms of these patients. A positive correlation between the circulating level of immunoreactive PTH and the extent of abnormality in the electroencephalogram (EEG) in humans has been reported. Moreover, in uremic dogs normalization of the EEG was observed after parathyroidectomy, and increased abnormality of the EEG was observed on infusion of PTH. If PTH is really a causal factor of uremic encephalopathy and abnormality of the EEG in patients with renal failure, the question arises as to whether PTH acts on the brain after penetrating through the blood-brain barrier or in some other way. In this work, we measured PTH by both C-terminal-specific RIA (C-PTH) and N-terminal-specific RIA (N-PTH) in the circulation and cerebrospinal fluid (CSF) of normal subjects and patients with renal failure. Blood and CSF samples were obtained from 7 normal volunteers (31 approximately 81 years old: 4 males and 3 females) and 22 patients with chronic renal failure (25 approximately 87 years old: 12 males and 10 females). No patients had a psychotic disease or endocrinopathy other than secondary hyperparathyroidism. Samples of venous blood were collected from the subjects after an overnight fast at the time of lumbar puncture for CSF sampling. C-terminal-specific RIA for measurement of the plasma and CSF concentrations of C-PTH was carried out using a commercially available RIA kit (Eiken Laboratory Inc., Tokyo, Japan).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1988

1,25-Dihydroxyvitamin D3 binds specifically to rat vascular smooth muscle cells and stimulates their proliferation in vitro.

Cultured vascular smooth muscle cells (VSMC) derived from rat aorta were found to contain a specific receptor for 1,25-dihydroxyvitamin D3 [1,25-(OH)2D3]. Its Kd (5.0 x 10(-11) M) and capacity (22.9 fmol/mg of cytosol protein) for 1,25-(OH)2D3, its sedimentation coefficient on a sucrose density gradient (3.2 S), its relative affinities for various vitamin D3 metabolites [1,25-(OH)2D3 greater than 25-hydroxyvitamin D3 greater than 24,25-dihydroxyvitamin D3 greater than vitamin D3] and its affinity for DNA-cellulose were similar to those reported for the 1,25-(OH)2D3 receptor in other tissues. 1,25-(OH)2D3 at concentrations of more than 10(-10) M caused dose-dependent enhancement of the proliferation of VSMC in DMEM with 10% FCS. 25-Hydroxyvitamin D3 stimulated the proliferation of VSMC only at its highest concentration tested (10(-6) M). These data show that 1,25-(OH)2D3 stimulates the proliferation of VSMC after its binding to a cytoplasmic receptor of the cells in vitro, and support the possibility that VSMC are target cells of the hormone.

Animals↗
PubMed1988

Preoperative parameters related to the improvement of semen characteristics after surgical repair of varicocele in subfertile men.

To know the parameter related to improvement of each semen characteristic (sperm density and percentage of progressive motile sperm) after high ligation of the left internal spermatic vein, 119 men from infertile couples were investigated. In each individual, the semen characteristic was considered to be different from the postoperative mean value if it was over or below 2 SD of the preoperative mean. Although no relationship was detected with the age of the patient, the duration of infertility or the preoperative semen characteristics, a definite relationship was found between the degree of varicocele and the improvement in each semen characteristic. For improvement of the sperm density, each of the volume and the score count by Johnsen's scale of the affected and unaffected testes and the serum hormone values (LH, FSH and testosterone) showed correlations. Meanwhile, for the improvement of the percentage of progressive motile sperm, correlations were found only with each of the testicular volume on the unaffected side and the serum testosterone level.

Adult↗
PubMed1988

Effect of estrogens on renal responsiveness to parathyroid hormone in elderly female subjects.

The effect of estrogens on the renal responsiveness to parathyroid hormone (PTH) was examined by PTH loading tests with synthetic human-PTH (1-34) in 8 normal elderly females (mean +/- SD age, 81.0 +/- 7.1 yr) before and after administration of estrogen (Premarin 1.25 mg/day for 4 weeks). Basal urinary adenosine cyclic 3', 5'-monophosphate (cAMP) excretion showed a tendency to increase after estrogen administration (5.47 +/- 1.68 vs 6.60 +/- 2.67 nmol/100 ml GFR) and the theoretical renal phosphorous threshold showed a tendency to decrease from 3.22 +/- 0.98 to 2.73 +/- 0.56 mg/dl. The blood ionized calcium concentration did not change after estrogen administration (4.44 +/- 0.16 vs 4.32 +/- 0.20 mg/dl) and serum phosphorous (P) decreased significantly (3.65 +/- 0.47 vs 3.01 +/- 0.42 mg/dl, p less than 0.05). There was no increase in mean serum immunoreactive PTH (0.34 +/- 0.10 vs 0.34 +/- 0.05 ngeq/ml). The urinary excretions of cAMP in response to PTH loading [100 U of human-PTH (1-34), intravenously] significantly (p less than 0.05) increased (94.8 +/- 57.0 vs 196.7 +/- 118.3 nmol/100 ml GFR/h) after estrogen administration. Moreover the changes in urinary excretion of cAMP (r = 0.698, p less than 0.01) and P (r = 0.555, p less than 0.05) induced by the PTH loading were positively correlated with serum estradiol in elderly females, assessed as groups before and after estrogen administration. These results suggest that estrogens may enhance the renal responsiveness to exogenous PTH administration.

Adult↗
PubMed1988

Induction of renin-angiotensin system in human testis in vivo.

To better understand the local renin-angiotensin system in Leydig cells of the human testis, the plasma renin activity (PRA) and plasma concentration of angiotensin II (PAII) in the left internal spermatic vein (ISV) and cubital vein (CV) were measured at the time of surgical repair of varicocele in 27 patients. Fourteen of the patients were given a single i.m. injection of hCG (10,000 IU/m2) 4 days before the operation, whereas the remaining 13 were not treated. Although the mean PRA or PAII levels in the CV in the treated and nontreated groups were similar, both levels in the ISV in the treated group were significantly higher than in the nontreated group (p less than 0.05). For PAII levels in the treated group, nine of 11 patients with an increased PRA level showed significantly higher levels than the normal peripheral PAII value. The serum testosterone levels in the same ISV were also much higher in the treated group than in the nontreated group (p less than 0.001). These results suggested the possibility that sex steroids might influence the renin-angiotensin system in Leydig cells.

Adult↗
PubMed1988

Optimal temperature for synthesis of DNA, RNA, and protein by human testis in vitro.

To determine the optimal temperature for DNA, RNA, and protein syntheses in the human testis, the levels of incorporation of 3H-thymidine, 14C-uridine, and 14C-leucine into testicular tissue were studied at 28 degrees C, 31 degrees C, 34 degrees C, and 37 degrees C in vitro. The results suggest that the DNA synthesis is at a maximum at 31 degrees C and shows delicate temperature sensitivity, whereas the RNA and protein syntheses are at a maximum at 34 degrees C or 37 degrees C and are temperature-dependent. It is concluded that the temperature sensitivity of DNA synthesis may be one of the primary causes of delicate thermal inhibition of human spermatogenesis.

Cells, Cultured↗
PubMed1988

Anthracycline-induced congestive heart failure in two pediatric leukemia cases and long term follow-up.

Endomyocardial biopsy was performed on two leukemia patients who had recovered from severe congestive heart failure (CHF) due to anthracycline cardiomyopathy at 41 months and 47 months after CHF. Microscopic myocardial findings in both patients revealed that myocytes were hypertrophic, but interstitial fibrosis was not observed, suggesting a compensatory mechanism for the damaged heart muscle during the acute episode of CHF. The improvement of clinical symptoms and the normalization of cardiac function, including fractional shortening and ECG changes, is thought to have been associated with this myocardial repairing process.

Adolescent↗