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Biomedical subjects

K Kohri

Publications and source records attributed to K Kohri.

At least 163 records · Page 9Linked to original sources

[Investigation on unsuccessful endoscopic operation for cases with vesicoureteral reflux].

Endoscopic operation of vesicoureteral reflux (VUR) has several advantages such as less invasiveness and technical ease with the procedure and shorter hospitalization for the operation in comparison with coeliotomy, but the cure rate achieved by endoscopic operation compares unfavorably with that by coeliotomy. The unsuccessful cases of VUR by endoscopic operation were investigated to promote the success rate by endoscopic operation. Of 66 ureters in 55 patients 50 were successfully treated with the first operation, and 4 of 8 ureters with the second one. All 15 infants were cured, but the cure rate in females between 17 and 45 year old was significantly low (57%). An equally high cure rate was obtained by the endoscopic operation even in patients who had a high grade VUR, patulous ureteral orifices, an underlying neurogenic bladder, or episodes of urinary tract infection. All ureters were cured just after operation. The recurrence of VUR occurred in 19 ureters (29%) and 16 ureters were discovered at one month examination after operation, which indicates that olive oil dissolving teflon paste was partly absorbed to bladder tissue. Teflon paste shifted to internal urethral orifice in 4 unsuccessful ureters. Based on these findings, the endoscopic operation should be considered to be the preferred treatment among others in the management of VUR and the injection of sufficient volume of teflon paste into submucosal and muscular space of the bladder trigone could promote the cure rate.

Adolescent↗

Relationship between metabolic acidosis and calcium phosphate urinary stone formation in women.

The relationship between the degree of metabolic acidosis and calcium phosphate stone formation was studied. Furthermore, the reasons why renal tubular acidosis (RTA) and primary hyperparathyroidism (PHPT) dominantly occur in women, and female stone formers more often produce calcium phosphate stone are discussed. Blood was slightly more acidotic in women than in men in both the urolithiasis and the control groups. Likewise, blood was significantly more acidotic and urinary pH significantly higher in patients with PHPT. Patients with RTA had severe metabolic acidosis, and urinary pH was highest among all groups. Calcium phosphate concentration was significantly higher in women than in men, and was also higher in patients with PHPT than in those with urolithiasis. All patients with RTA had pure calcium phosphate stones. The reasons why females are more acidotic and have more calcium phosphate in stones are suspected to be related to progesterone and urinary tract infection.

Acidosis, Renal Tubular↗

Epidemiology of urolithiasis in the elderly.

To estimate the epidemiology of upper urinary stones in the elderly, a total of 1,957 patients (1,349 men and 608 women) with urolithiasis were studied. The ratio of men to women was approximately 3:1 in middle-aged (between 30 and 59 years), 1:1 in young (29 or younger) and 1:1 in old patients (60 or older). Compared with the age distribution of the entire Japanese population, the incidence of urinary stones was very low in both male and female children, twice as high in middle-aged men, slightly higher in middle-aged women, and equal or slightly lower in the male and female elderly. Stones of calcium oxalate and uric acid occurred more frequently and those of calcium phosphate and struvite less frequently in men than in women. This tendency was especially obvious in the middle-aged. In the old generation, calcium oxalate stones occurred almost equally in men and women. Results of urinary stone analysis were similar among men of the three generations, although the incidence of uric acid stones increased with patient age. In women, however, the incidence of calcium oxalate was higher in the young and old generations, while that of calcium phosphate was higher in the middle-aged.

Adolescent↗

Simple tests to determine urinary risk factors and calcium oxalate crystallization in the outpatient clinic.

We developed 2 simple and rapid tests for measurement of constituent concentrations and the stone-forming tendency of urine in the outpatient clinic. The concentrations of urinary constituents of calcium, magnesium, phosphorus, uric acid and oxalic acid were measured using 2 types of simple colorimetric tests (vial and quantitative filter types). The intensity of the color developing after a given interval was compared with a color standard of 4 levels. The results obtained using the colorimetric test were slightly lower in value than but significantly correlated with those obtained with standard measurements. The second test measured the crystal-forming ability of urine. A 10 ml. urine sample was pipetted into 4 vials that each contained different concentrations of oxalic acid and calcium. After a given interval the turbidity in each vial was compared with a control (0 mg. oxalic acid and calcium). If turbidity occurred in urine with low concentrations of oxalic acid and calcium the sample had a large tendency for crystals to form.

Ambulatory Care↗

Effect of endocrine therapy on a brain metastatic lesion of prostatic carcinoma.

We describe a 62-year-old male with brain metastasis from prostatic carcinoma, which regressed with medical and surgical endocrine therapies. The patient's presenting complaints were left periocular and deep ocular pain and a defect of the left visual field. During treatment of the above symptoms, macrohematuria, dysuria and pollakiuria occurred. Pathological examination of a transrectal needle biopsy disclosed moderately differentiated adenocarcinoma of the prostate. Computerized tomographic scan (CT) and magnetic resonance imaging demonstrated a brain tumor at the frontal skull base and the region of the frontal lobe suspected to be a metastasis of the prostatic carcinoma. One week after a period of daily administration of estramustine phosphate sodium, the prostate was observed to be softened and slightly decreased in size. The visual field defect and disturbance of urination gradually improved. The prostate decreased to normal size and no tumor mass could be detected on the brain CT after 3 months of treatment.

Adenocarcinoma↗

Characteristics and usage of different ureteral stent catheters.

Presuming that complications associated with ureteral stenting vary in type and occurrence depending on the material and cross-section of the stent, six types of stents immersed in 48 different preparations of artificial urine for 1 month to observe surface changes with a scanning electron microscope. As a result, there was less encrustation on the silicone material compared with other material types, probably due to the smoothness of the surface. This may be related with higher frequency of spontaneous removal or migration to the bladder of this catheter type. Because silicone catheters have softer and thicker walls with a narrow lumen, they may be appropriate for long-term stenting, but not for urinary drainage. In alkaline bacteriuria, struvite encrustation was observed on all stents. This reaction was especially intense with Towers peripheral stents, which had most irregular and uneven surfaces. In aseptic alkaline urine, calcium phosphate crystals partly covered with proteinaceous debris were noted on catheter surfaces. Although in some patients encrustation of uric acid occurred in the bladder portion of the stents, there was no uric acid encrustation in this experimental study.

Crystallization↗

Immunofluorescent study on the interaction between collagen and calcium oxalate crystals in the renal tubules.

The interaction of calcium oxalate crystals and renal tubular cells was studied. Rat renal collecting tubular cells were cultured and immunologically stained with anti-type-IV collagen antiserum (type-IV collagen exists in renal tubular basement membrane). When renal tubular cells and calcium oxalate crystals were mixed, clumps were formed. These clumps were examined by immunological staining with anti-type-IV collagen antiserum. In another series of experiments, calcium-containing crystals were found to be adsorbed onto mucous threads and cast-like materials, although no such adsorption was observed on squamous cells. These absorbed materials interacted with anti-type-IV collagen antiserum. These results suggest that collagen in the renal tubular basement membrane may act as matrix in urinary stone formation.

Animals↗

[The anticancer effects of high energy shock waves on rat bladder cancer induced by BBN].

The in vivo anticancer effects of high energy shock waves (HESW), on bladder cancer induced by N-butyl-N-(4-hydroxybutyl) nitrosamine (BBN), were studied in the rat using the Siemens lithotriptor (Lithostar). There was no significant difference in the anticancer effects in delaying tumor growth, measured as the whole bladder weight including the weight of the cancer, between the groups with and without exposure to HESW. However, light microscopic examination revealed extensive submucosal bleeding and exfoliation of mucosa, and electron microscopic examination revealed degeneration of pleomorphic microvilli, swelling of mitochondria, and destruction of mitochondrial cristae in the cancer cells in bladders exposed to HESW. Flow cytometric determination of DNA content in the cancer cells exposed to HESW indicated a selective diminution of cells in the G2 and M phases and an increase of cells in the G0 and G1 phases of the cell cycle. While the mechanism of HESW-induced anticancer effect could not be determined on the basis of this study, these changes in the morphology and the cell cycle of cancer cells induced by HESW exposure suggest some kind of biological effects following exposure to HESW. It is expected that HESW be an effective method for the treatment of human cancer in combination with chemotherapy and radiation.

Animals↗

[Clinical study of extracorporeal shock wave lithotripsy for stones in solitary kidney].

Extracorporeal shock wave lithotripsy (ESWL) treatment was performed on 17 patients with a solitary or sole functioning kidney from August 1986 to April 1988. Some patients with renal stone had a double pig tail catheter to protect the stone street and those with ureteral stones had a ureteral balloon occlusion catheter to raise the efficiency of fragmentation placed prior to ESWL as much as possible. Combined manipulation with such an instrument as nephrostomy tube to wash out residual stone fragments or endoscopic operation were performed. Despite of these devices, ESWL treatments for staghorn calculi and cystine stones were troublesome in solitary kidneys. After follow up ranged from 9 to 602 days (mean 87.6 days), 10 patients (58.8%) were stone free. ESWL treatment is safe and effective for solitary kidneys. We recommended premedication and pretreatment by ureteral stenting in patients with a solitary kidney.

Adult↗

[Studies on renal damages after extracorporeal shock wave lithotripsy using Gd-DTPA-enhanced dynamic MRI].

Renal damages after ESWL treatment were examined by Gd-DTPA enhanced dynamic MRI. Gd-DTPA was used as the contrast medium and fast magnetic resonance imaging with suspended respiration using the flip angle of 20 degrees and gradient echo technique at 0.5 Tesla was used for photographing. In normal kidneys, a low intensity band was observed with the passage of Gd-DTPA through the kidney from 1 to 2 minutes after the injection. In patients who underwent ESWL treatment, however, the low intensity band which was observed before ESWL treatment became partly obscure after ESWL treatment. Furthermore, these find changes in the renal parenchyma could not be fully detected by usual MRI which does not use Gd-DTPA. Gd-DTPA enhanced dynamic MRI was considered to be effective for finding the limited dose of shock waves for ESWL treatment.

Adult↗

[Indications for surgical treatment of secondary hyperparathyroidism].

From 1978 to 1990 subtotal parathyroidectomy was carried out on 41 patients for secondary hyperparathyroidism. The indications for parathyroidectomy and suitable operative time, especially in the point of view of renal osteodystrophy are discussed. Serum ALP and PTH level and the presence of generalized fibrous osteitis were good indicators for parathyroidectomy. Furthermore, 99mTc-Pyrophosphate bone scintigraphy and Dual Photon Absorptiometry were proved to be valuable for patient selection for parathyroidectomy. Parathyroidectomy for patients in whom 99mTc-pyrophosphate bone uptake is diminished or patients in whom bone mineral contents are dramatically decreased must be carefully performed.

Absorptiometry, Photon↗

[Clinical study in infants with vesicoureteral reflux].

A clinical study was performed on 52 infants up to 2 years old with vesicoureteral reflux. We treated 12 of them conservatively. Half of them dropped out within 1 year. It was very difficult to follow up the infants over a long time in the conservative treatment group. As a result of the conservative treatment, reflux disappeared spontaneously in only 2 infants. Forty infants underwent antireflux operations. The reflux disappeared in all cases. However, we injured the peritoneum in 2 cases when the Politano-Leadbetter method was applied. A modified Politano-Leadbetter method was adopted because of the peritoneum injury. As an antireflux operation on infants, the modified Politano-Leadbetter method is desirable. Renal function and growth were studied. Renal function was assessed with 99m-Tc-DTPA renograms. Renal ratio was evaluated by intravenous pyelography. The function of refluxing kidneys Severely damaged was not improved after the antireflux operations. The small kidneys with a high grade or the atrophic kidneys did not demonstrate normalization of renal growth after antireflux operations. In conclusion, it is important to detect the reflux at the early infant stage and perform the antireflux operation at an early stage in the case of high grade or renal impairment.

Child, Preschool↗

Determination of urinary oxalate by high-performance liquid chromatography monitoring with an ultraviolet detector.

High-performance liquid chromatography (HPLC) monitoring with an ultraviolet detector was carried out to measure urinary oxalate levels in urolithiasis. Interfering substances in urine were removed by anion exchange prior to chromatography. This procedure was found excellent with respect to sensitivity, reproducibility, and analytical recovery. The findings were in agreement with colorimetric date. The mean oxalate level in 24-hour urine was 30.5 +/- 15.1 mg in patients with a single episode and 36.3 +/- 9.8 mg in recurrent stone formers. The latter values was significantly higher than the normal control level (27.4 +/- 3.8 mg).

Adult↗

Effect of high energy shock waves on tumor cells.

Exposure of bladder tumor cell strain HT-1197, chronic bonemarrow leukemic cell strain K-562, and African green-turtle normal kidney cell strain Vero to high energy shock waves resulted in ultrastructural changes and a reduction in cell viability as determined by 3H-thymidine incorporation assay and flowcytometer. K-562 was the most sensitive while Vero was the most resistant to the high energy shock wave. By flowcytometry using anti BrdU antibody, described K-562 in the S phase was found to be inhibited by the exposure. Electron microscopy revealed destruction of microvilli over the cell surface and swollen mitochondria in K-562 and HT-1197. These effects were related to the number of high energy shock wave exposures. Our study demonstrates that a high energy shock wave has an anti-tumor effect in vitro.

Animals↗

Relationship of plasma and urine composition to recurrence of calcium urinary stones in patients on drug therapy.

Factors relating alterations in plasma and urine composition to recurrence of urinary stones during drug therapy were investigated by using a multiple regression analysis technique. These factors were influenced not only by the efficacy of the drugs but also by other factors (plasma or urinary constituents and overall health of the patients, etc.). In order to study the effect of drug therapy or other treatment on the alteration of plasma and urine constituents, multiple regression analysis is more appropriate than Student's paired t-test which has been used by some workers. These two analytical methods yield different results even if used on the same data.

Adult↗

Allopurinol and thiazide effects on new urinary stone formed after discontinued therapy in patients with urinary stones.

We treated 87 patients with calcium-containing urinary stones with either allopurinol alone (44 patients) or in combination with thiazide (43 patients) and studied new stone formation before, during, and after the discontinuation of the drug therapy. The number of stones formed were 1.18, 0.24, and 0.13 before, during, and after discontinuation of the drug therapy, respectively, in the patients treated with allopurinol alone and 1.32, 0.20, and 0.09 in those treated in combination with thiazide. No differences were observed in these values and the duration of each observation period between the two groups. Decreases in the incidence of stone formation even after interruption of drug therapy suggested that recurrence-preventive effects observed following administration of these drugs include the effects of medical guidance. However, allopurinol therapy was effective in preventing recurrence in patients with hyperuricosuria.

Allopurinol↗

Calcium oxalate crystal formation in patients with hyperparathyroidism and hyperthyroidism and related metabolic disturbances.

The crystallization of calcium oxalate in the urine of patients with hyperparathyroidism and hyperthyroidism was studied using a mixed suspension mixed product removal (MSMPR) system. In addition, calcium metabolism in hyperthyroidism and its relationship to urolithiasis was investigated. The urines from all the three groups (normal subjects, hyperparathyroid and hyperthyroid patients) showed reduced nucleation rates and increased growth rates in comparison with the control synthetic urine. The nucleation rate was not significantly different between the three human urine groups, while the growth rate was significantly higher in the hyperparathyroid group compared to the normal and hyperthyroid groups. Crystal volume (suspension density) in the hyperparathyroid group was approximately twice that in the other two groups. Serum and ionized calcium levels in hyperparathyroid patients were higher than in normal subjects, while hyperthyroid patients had levels only slightly higher than those in normal subjects. The hyperparathyroid and hyperthyroid groups differed significantly from the normal group in urinary calcium excretion. These two groups also showed significantly higher levels of serum alkaline phosphatase and urinary hydroxyproline than did the normal group. Although hyperthyroid patients have a calcium metabolism similar to hyperparathyroid patients, the incidence of urolithiasis is no different between hyperthyroid and normal subjects. The results of both crystallization and calcium metabolism in hyperparathyroid patients were not significantly different between those with and without urolithiasis. The result of crystallization was also not significantly different between hyperparathyroid patients with and without hypercalciuria. This study suggests that hypercalciuria alone does not produce urinary stones and that urine from hyperparathyroid patients may contain promotors of calcium oxalate crystallization and calcium stone formation.

Calcium Oxalate↗