Biomedical subjects

K Kohri

Publications and source records attributed to K Kohri.

At least 145 records · Page 8Linked to original sources

PubMed1993

Relationship between the incidence infection stones and the magnesium-calcium ratio of tap water.

In a previous study we showed that the magnesium-calcium ratio of tap water is negatively correlated with the incidence of calcium-containing urinary stones. In this study we examined the relationship between the incidence of struvite stones, water hardness and the regional geological features on the basis of our previous study and an epidemiological study of urolithiasis performed in Japan. The magnesium-calcium ratio of tap water was found to correlate positively with the incidence of struvite stones. The tap water magnesium-calcium ratio was high in regions of basalt and sedimentary rock and was low in granite and limestone areas. The incidence of struvite stones in the regions of basalt and sedimentary rock was higher than that in the granite and limestone areas. Thus, this study suggested that the incidence of struvite stones is related to the magnesium-calcium ratio of tap water and to the regional geology, as is the case for calcium-containing stones.

Calcium↗

PubMed1993

Studies on changes in parameters of the coagulation and fibrinolysis in association with extracorporeal shock wave lithotripsy.

Tissue damage by extracorporeal shock wave lithotripsy (ESWL) is assumed to be attributable to ischemic changes in the treated region surrounding the particular vessel which is first ruptured by shock waves. Such changes cannot take place without being accompanied by acceleration of coagulation and fibrinolysis. In the literature on renal damage by ESWL, no parameters of the coagulation and fibrinolysis of blood were used. The present study was designed to investigate renal damage by shock waves through the quantification of sequential changes in the following parameters between before and after ESWL: thrombin antithrombin III complex (TAT), alpha 2-plasmin inhibitor-plasmin complex (PIC), fibrin and fibrinogen degradation products (FDP) and D-dimer (D-D). In ESWL for renal stones, a significant acceleration of TAT occurred on the 1st postoperative day, followed by acceleration of PIC on the 3rd postoperative day. A transient acceleration was observed for FDP and D-D after operation. The levels of these parameters, however, returned to normal by the 1st postoperative week. In ESWL for ureteral stones, unlike for renal stones, none of the parameters showed statistically significant acceleration. In the construction of percutaneous nephrostomy (PNS) cases for ureteral stones before ESWL, none of the parameters showed significant acceleration either. Changes in these parameters of coagulation and fibrinolysis due to ESWL for renal stones were greater than those of construction of PNS or ESWL for ureteral stones. The reason for the difference of the alteration in these parameters between renal stones and ureteral stones were more abundant vessels in the kidney than the ureter. All these changes in the parameters, however, disappeared within almost 1 week.

Antifibrinolytic Agents↗

PubMed1993

Continuous evaluation for retroperitoneal hematoma following extracorporeal shock wave lithotripsy.

In this paper we report on a patient with extensive retroperitoneal hematoma due to extracorporeal shock wave lithotripsy (ESWL) for a renal stone. The patient had a negative history of previous primary renal disease or risk factors for retroperitoneal hemorrhage after ESWL. The hematoma was treated conservatively and it was completely absorbed 9 months after ESWL as evaluated by computed tomography. Gd-DTPA-enhanced dynamic magnetic resonance imaging (dynamic MRI) was performed immediately after formation of the hematoma. The decrease in renal blood flow in the affected kidney could be observed in this patient by dynamic MRI and its time intensity curve.

Adult↗

PubMed1993

Glucose metabolism in renal stone patients.

The calciuric response and the changes of plasma glucose and insulin produced by a 75-gram oral glucose tolerance test were determined in 27 male patients with idiopathic calcium renal stones (6 with dietary hypercalciuria, 5 with nondietary hypercalciuria and 16 with normocalciuria) and 22 healthy male subjects. The subjects were classified as obese (> or = 120% ideal weight) and nonobese. The incidence of an abnormal response to glucose loading was similar in the stone patients and the healthy subjects. In addition, the plasma glucose and insulin levels after oral glucose load did not differ between the stone patients and control subjects and were affected by the individual degree of obesity. Urinary calcium excretion increased significantly after glucose ingestion in both the stone patients and the control subjects. Urinary calcium excretion was greater in the stone patients than in the control subjects due to the presence of patients with nondietary hypercalciuria, and the increment in urinary calcium excretion in the dietary hypercalciuric and normocalciuric stone patients was indistinguishable from that in the control subjects. The degree of obesity did not affect the increment in urinary calcium excretion. These results suggest that overconsumption of refined carbohydrates such as sugar-sweetened soft drinks, soda and cakes may be a risk factor for stone formation, especially in the patients with nondietary hypercalciuria.

Adult↗

PubMed1993

[Transurethral teflon paste injection for vesicoureteral reflux in neurogenic bladder dysfunction].

We experienced transurethral teflon paste injection for 12 refluxing ureters of 7 patients with neurogenic bladder dysfunction. Preoperative assessment of cystometry showed hypoactive bladder function with normal bladder compliance in 4 patients, and low compliance bladder (< 10 ml/cmH2O) in 1. Voiding cystography revealed grade 1 reflux in 2 ureters, grade 2 in 3, grade 3 in 2, grade 4 in 2, and grade 5 in 2. One ureter did not show reflux. Zero point two to 1.6 ml of teflon paste was injected on each ureter under cystoscopic observation. These patients were followed for a mean of 25.1 months. Reflux disappeared immediately after the first operations in all patients, however recurrence was observed in 2 ureters, in which improvement of reflux (grade 5 to 2) was achieved in 1 ureter but no improvement (grade 2 to 2) in another. Pyelonephritis was not encountered in any patients after injection. No complication was observed through the follow up period. In conclusion, we advocate that endoscopic teflon paste injection is a useful alternative to ureteroneocystostomy in the treatment of reflux in patients with neurogenic bladder dysfunction.

Aged↗

PubMed1993

[A case of an infant on continuous ambulatory peritoneal dialysis who markedly improved in subjective symptoms after total parathyroidectomy and autotransplantation].

Total parathyroidectomy and autotransplantation to treat secondary hyperparathyroidism (SHP) have been often performed on adult patients with a favorable result, but have rarely been reported in the pediatric literature. We performed the above operations on a 4-year-7-month girl who was treated by continuous ambulatory peritoneal dialysis (CAPD). The postoperative levels of serum calcium remained low in spite of oral calcium and Vitamin D3 medication, and intravenous calcium administration. But an administration of calcium into CAPF fluid has been maintained the normal level of serum calcium. A calcium balance study conducted for 3 days starting the 24th postoperative day showed 391 mg/day of calcium absorption. The girl obtained a relief from the bone pain approximately 2 weeks after the operation and was able to run easily one and a half month after the operation. Total parathyroidectomy and autotransplantation were considered to be an effective treatment for severe symptoms of osteodystrophy in infantile patients with chronic renal failure.

Child, Preschool↗

PubMed1993

[Evaluation of preoperative diagnosis of primary hyperparathyroidism--special reference to normocalcemic cases].

Since the opening of our clinic 117 years before, we have treated 62 cases of primary hyperparathyroidism (PHPT), among which there were 6 cases (1 male, 5 females) whose calcium levels fell within the normal range. However, in all these cases the serum ionized calcium (Ca++) levels and the serum ionized calcium/calcium ratio (Ca++/Ca ratio) were high. Moreover, in comparing them with hypercalcemic patients (56 cases), the serum Ca++ levels were significantly lower, but the (Ca++/Ca ratio) was significantly higher. Also, the excised weight of 606.1 +/- 520.3 mg was significantly smaller than that of hypercalcemic patients, which was 1,967.9 +/- 2,086.3 mg. Preoperative locations showed significantly lower levels in comparison with hypercalcemic patients by all methods including computed tomography (CT), ultrasonography, scintigraphy, and magnetic resonance imaging (MRI). In normocalcemic patients following parathyroidectomy, although the decrease in serum calcium levels was not significant, the serum Ca++ levels and the Ca++/Ca ratio decreased significantly, so that not only are they useful parameters for preoperative diagnosis of PHPT, but they are also considered necessary and indispensable for observation of the post-operative course and judging therapeutic effects including the operation. Based on our study we concluded that in multiple and recurrent stone formers with normal range of serum Ca levels, regardless of the presence or absence of local diagnosis, if the serum Ca++ level and Ca++/Ca ratio are high, existence of primary hyperparathyroidism must be suspected, and adequate treatments should be instituted promptly.

Calcium↗

PubMed1993

Expression of osteopontin messenger RNA by macrophages in atherosclerotic plaques. A possible association with calcification.

Calcification is a common complication in atherosclerosis. As osteopontin (OPN) and osteonectin (ON) are not only involved in the physiological but also the pathological calcification of tissues, we examined the expression of OPN and ON messenger (m)RNAs in normal and atherosclerotic human aortas. By Northern blotting, the OPN mRNA expression was related to the severity of the atherosclerosis. However, ON mRNA expression decreased with the development of atherosclerosis. By a combination of in situ hybridization and immunohistochemistry of serial sections, the macrophages surrounding the atheromatous plaques were identified as the OPN mRNA-expressing cells. The ON mRNA-expressing cells in aortas of a newborn baby and a 3-year-old boy were medial smooth muscle cells, but in aortas of adults, smooth muscle cells that had invaded the intima were found to express ON mRNA. As OPN mRNA-expressing macrophages surrounded the atheromatous plaques, and as the level of OPN mRNA expression increased as atherosclerosis advanced, it is possible that OPN plays a role in the calcification of atheromatous plaques.

Aged↗

PubMed1993

[Septic shock induced by extracorporeal shock wave lithotripsy treatment with percutaneous nephrostomy in 5 cases with urolithiasis].

We have experienced 5 cases of septic shock induced by extracorporeal shock wave lithotripsy (ESWL) and percutaneous nephrostomy. We suspected 5 causes of septic shock; severe hydronephrosis, nephrostomy tube itself, an increase of intrarenal pressure, bacteria in urinary stone, and hepatic failure. Based on the above suspected causes of septic shock, we suggested 3 prophylactic treatments for septic shock; a preventive administration of antibiotics before ESWL and percutaneous nephrostomy, proper management of nephrostomy tube, and early diagnosis and treatment for septic shock.

Aged↗

PubMed1993

[Effect of verapamil on urinary calcium and oxalate excretion in renal stone formers].

The effect of the calcium antagonist verapamil on urinary calcium and oxalate excretion was examined and compared with that of trichlormethiazide to evaluate whether verapamil is useful in the prevention of calcium oxalate renal stones. Twenty-four-hour urine of 16 renal stone formers was measured at the outpatient clinic before and after administration of 120 mg/day verapamil for a mean duration of 2.7 months (range, 2 weeks to 6 months). The 24-hour urine was analyzed for creatinine, calcium, oxalic acid, magnesium and citric acid and the results compared with those in 20 renal stone formers who were administered trichlormethiazide. Verapamil was found to significantly reduce the urinary oxalate excretion of the 5 hyperoxaluric (> or = 50 mg/day) patients but no significant effect on urinary calcium, magnesium or citric acid was observed. Conversely, trichlormethiazide significantly decreased urinary calcium excretion in the hypercalciuric (> or = 250 mg/day) patients. Calcium oxalate risk index of hypercalciuric and hyperoxaluric patients was significantly reduced after the administration of verapamil. These findings suggest that verapamil is effective in reducing urinary oxalate excretion in the hyperoxaluric patients.

Calcium↗

PubMed1992

Recognition of an antiparallel beta-sheet structure of human epidermal growth factor by its receptor. Site-directed mutagenesis studies of Ala-30 and Asn-32.

The Ala-30 and Asn-32 residues involved in the major antiparallel beta-sheet structure of human epidermal growth factor (hEGF) were substituted with various amino acid residues, and the receptor-binding affinities of the nine variant hEGFs were determined by the use of human KB cells. The Ala-30----Arg, Ala-30----His and Ala-30----Phe substitutions drastically reduced the binding affinity, suggesting that the side chain in position 30 of Ala-30 of hEGF is required to be small for the receptor binding. The Asn-32----Asp substitution significantly reduced the binding affinity, while the Asn-32----His variant could bind to the receptor as well as to the wild-type hEGF. Therefore, it seems to be important for receptor binding that the side chain in position 32 does not have a negative charge but does have an NH group. Thus, we propose that, in the ligand-receptor complex, the receptor recognizes, on one side of the antiparallel beta-sheet structure of hEGF, a wider contact area than previously suggested.

Alanine↗

PubMed1992

Molecular cloning and sequencing of cDNA encoding urinary stone protein, which is identical to osteopontin.

We have sequenced a cDNA of urinary stone protein. cDNA sequences show complete homology between urinary stone protein and human osteopontin (bone sialoprotein) (nucleotides 265-886 and 1183-1424). Osteopontin is a recently discovered bone matrix protein which has been implicated in mediating mineral formation within bone extracellular matrix. This result shows that osteopontin is presumably involved in stone formation as stone matrix.

Base Sequence↗

PubMed1992

A site-directed mutagenesis study on the role of isoleucine-23 of human epidermal growth factor in the receptor binding.

The isoleucine-23 residue of human epidermal growth factor (hEGF) was substituted by a variety of amino acid residues and the receptor-binding activities of variant hEGFs were determined by the use of human KB cell. Tight receptor binding was found of variants with hydrophobic amino acid residues in position 23. The size of the isoleucine residue was nearly optimum for the receptor binding as compared with other hydrophobic residues. The structure analysis by two-dimensional nuclear magnetic resonance spectroscopy showed that the substitution at position 23 only slightly affected the tertiary structure of hEGF. These indicate that the side chain of isoleucine residue in position 23, which is exposed on the protein surface, directly binds to a hydrophobic pocket of the receptor.

Amino Acid Sequence↗

PubMed1992

A new method for determination of urinary citrate.

We have developed a new assay technique using high-performance liquid chromatography. The assay was performed at a flow rate of 0.7 ml/min, a temperature of 60 degrees C and an ultraviolet absorption of 214 nm. Comparison of the results of the new assay with the results obtained for identical samples using the conventional fluorometric method demonstrated a very high correlation coefficient of 0.931.

Adult↗

PubMed1992

Comparison of imaging methods for localization of parathyroid tumors.

Preoperative localization of parathyroid tumors by computed tomography (CT), thallium-201/technetium-99m pertechnetate subtraction scintigraphy (Tl-201/Tc-99m), ultrasonography (US), and magnetic resonance imaging (MRI) was compared in patients with hyperparathyroidism (HPT) to examine the characteristics of each method. A total of 87 patients with HPT were divided into two groups according to the time when they were examined. Patients in group I were examined before MRI had been introduced in our hospital, and a 2.5-MHz transducer probe was used for US. Those in group II were examined by MRI and US using a 7.5-MHz transducer probe. Group I included 45 patients (36 with primary hyperparathyroidism [PHPT] and 9 with secondary hyperparathyroidism [SHPT]), and group II included 42 patients (15 with PHPT and 27 with SHPT). In both PHPT and SHPT and SHPT of group I and PHPT of group II, there was no significant difference in detection rates between all diagnostic methods. In patients with SHPT in group II, the detection rate was significantly higher for CT than for Tl-201/Tc-99m and MRI (both p less than 0.01), and for US than for Tl-201/Tc-99m (p less than 0.01). In both groups I and II, the detection rate of each study method was significantly higher in patients with PHPT than in those with SHPT (all p less than 0.01). Compared with group I, the rate was significantly improved in group II, in both types of patients. Regarding the location of the parathyroid tumor, the detection rate of CT was significantly higher for upper parathyroid glands than for lower glands, whereas that of US and Tl-201/Tc-99m was significantly higher for lower glands. The detection rate sharply increased when the tumor weight reached 250 mg (CT, US) or 1,000 mg (Tl-201/Tc-99m, MRI).

Adult↗

PubMed1992

Influence of morphologic factors on calcium-containing stone formation.

Pathogenesis of urolithiasis cannot be explained only by metabolic disorder. In the present study, morphologic differences of the renal pelvic-caliceal system (PCS) were examined on both the stone and normal sides in calcium-containing stone formers. The results indicated that as compared to the normal side, the urine flow in the PCS was stagnant or not straight on the stone side even in the same individual, showing unfavorable conditions for stone formation. It is therefore considered that morphologic disorders of the urinary tract may be one of the causes for stone formation.

Adult↗

PubMed1992

Renal damages after extracorporeal shock wave lithotripsy evaluated by Gd-DTPA-enhanced dynamic magnetic resonance imaging.

Renal damages after extracorporeal shock wave lithotripsy (ESWL) were evaluated by magnetic resonance imaging (MRI) including Gd-DTPA-enhanced dynamic MRI in 37 patients with renal stone by spin echo methods (T1 and T2-weighted scan) and small tip angle gradient echo method (T2-weighted scan). Sixty-eight percent of the patients had changes in the MRI findings after ESWL. The frequently observed findings were perirenal fluid collection (38%), loss of corticomedullary junction (35%), and increased signal intensity of muscle and other adjacent tissue (34%). Preoperative Gd-DTPA-enhanced dynamic MRI showed low intensity band which suggests Gd-DTPA secretion from the glomerulus into the renal tubulus. In all cases the low intensity band became unclear after ESWL because of renal contusion due to ESWL. MRI, including Gd-DTPA-enhanced dynamic MRI, is considered to be a good procedure for evaluation of renal damages due to ESWL.

Contrast Media↗

PubMed1992

[Study of factors requiring more than two ESWL treatments].

Nine hundred and fifty cases with renal and ureteral stones were treated by extracorporeal shock wave lithotripsy (ESWL) with Siements Lithostar unit from September, 1988 to October, 1990 at Kinki University Hospital. ESWL treatments were performed twice or more on 110 cases (DIFFICULTY GROUP). Ninety-seven cases who were cured by only one ESWL treatment were selected randomly as the control group. The two groups were retrospectively compared to study the factors requiring more than two times of ESWL treatments. There was a significant difference in the time of spontaneous stone discharge before ESWL treatment, the degree of hydronephrosis and the incidence of staghorn calculi as well as middle-lower ureteral calculi between the two groups. There was not a significant difference but a tendency to a longer period of stone existing at the same position and a higher percentage of past history of percutaneous nephrolithotropsy (PNL) in DIFFICULTY GROUP. Because ESWL monotherapy is considered to have limitations, auxiliary procedures or other treatments such as PNL and transurethral lithotripsy are recommended for patients in who in the stones were poorly disintegrated by the first ESWL treatment.

Humans↗