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Biomedical subjects

R Konda

Publications and source records attributed to R Konda.

At least 37 records · Page 2Linked to original sources
PubMed1993

[Renal function of contralateral kidney after total or partial removal of kidney with ectopic ureter].

The effects of partial or total removal of the kidney with ectopic ureter on the contralateral kidney were evaluated using DMSA renal uptake rate on 8 patients. After partial nephrectomy on 6 cases, the affected residual kidneys showed significant decrease in DMSA renal uptake rate in 2 cases in which the extirpated kidneys had normal renal tissue in part but did not show significant change in DMSA uptake rate in 4 cases in which the extirpated kidneys were dominated mainly with dysplasia. Post-operative increase in DMSA uptake rate of the contralateral kidneys were significant in 3 of 4 patients who had the operation before they became 2 years old. In 2 of these 3 cases, pre-operative scintigram showed extremely low rate of DMSA renal uptake. Four cases aged 2 years old and over did not show post-operative increase in the uptake rate. As we have previously reported on the cases with hydronephrosis, these results suggest that 1) existence of obstruction caused by ectopic ureter inhibit the development of the contralateral kidney and 2) the growth of the kidney can resume the release of that obstruction, if the release is made while the kidneys are still in developing stage.

Child↗
PubMed1993

[Studies on reflux nephropathy--renal tubular and glomerular damage evaluated by various urinary indices].

Measurements were performed on beta 2-microglobulin (beta 2-MG), alpha 1-microglobulin (alpha 1-MG), N-acetyl-beta-D-glucosaminidase (NAG) as indices of renal tubular damage and microalbumin as an index of renal glomerular damage in 204 cases with primary vesicoureteral reflux (VUR). Investigations were made on the relationship between each index and extent of renal cortical damage from the findings of 99mTc-dimercapto-succinic acid (DMSA) renoscintigraphy, and also on the changes of each index before and after antireflux operation. At the first examination, high values of urinary beta 2-MG, alpha 1-MG, NAG and albumin were noted in 36%, 40%, 50% and 34% of cases with VUR respectively. Almost all the cases with high indices values before the operation showed improvement in those values accompanied with disappearance of VUR after the operation. These findings suggest that renal tubular and glomerular damage were induced by the sterile reflux itself. High values of urinary indices were confirmed in 16% (beta 2-MG), 40% (alpha 1-MG), 27% (NAG) and 32% (albumin) cases after a lapse of 2 years or longer since antireflux operation or spontaneous disappearance of VUR. In some of these cases indices values showed some improvement but have not returned to normal levels, and in other cases indices were within normal limits preoperatively but turned out to be high levels during the observation period even after the disappearance of VUR. Most of these cases were accompanied with severe cortical damage of unilateral or bilateral kidneys on DMSA renoscintigraphy. Based on these findings, we suggest that overload to residual nephron, caused by reduced mass of functional nephron, is playing an important role on raising the values of various urinary indices.

Acetylglucosaminidase↗
PubMed1993

[The effect of unilateral ureteral obstruction on the contralateral renal growth in weanling rats].

The effect of unilateral hydronephrosis on the growth of contralateral kidney were evaluated with weanling rats of which kidneys were in growing stage (body weighted between 80 g and 90 g). These rats underwent complete unilateral ureteral obstruction (CUUO) on day 0. They were divided into 3 groups and went through second operations on day 3 (CUUO-3) as follows; a) CUUO released, b) nephrectomy performed and c) CUUO continued. Sham-operation was performed on day 0 and on day 3 to the controls. Wet weights and bromodeoxy-uridine (BrdU) labeling index (L.I.) (index for cell proliferation in the uriniferous tubules) of the contralateral kidneys were measured for the evaluation. The wet weights were significantly higher in all the groups than that of the controls throughout the observation period on and after the day 3. The group that underwent nephrectomy demonstrated a sharp rise in L.I. after the day 7. In the group that was continued in CUUO, the L.I. started to rise later than its rise in nephrectomised group but the index caught up at the time when the blood flow completely disappeared in the kidneys of the ligated side. L.I. in the group of which CUUO was released became significantly higher than that of controls on the day 7 and remained its significance until the day 21 in spite of resolution of the hydronephrosis. To reveal the effect of length of obstructed term, the same trial was carried out that rats endured in CUUO for 5 days (CUUO-5) till the second operation. This turned out lower L.I. in the CUUO-5 than the CUUO-3. These results suggest that the presence of hydronephrosis made by CUUO suppress the growth (cell proliferation) of contralateral kidney and also duration of obstruction can be critical on the renal growth that shorter obstructed period turns out preferable for cell proliferation after relief of CUUO.

Animals↗
PubMed1992

[Evaluation of renal function and prediction of renal functional recovery in children with unilateral hydronephrosis using renal pelvic urine].

In 29 children with unilateral hydronephrosis who underwent surgery at the age from 2 months to 15 years (27 patients with ureteropelvic junction stenosis and 2 with obstructive megaureter), beta 2-microglobulin (beta 2-MG), alpha 1-microglobulin (alpha 1-MG), N-acetyl-beta-D-glucosaminidase (NAG) and albumin were determined in renal pelvic urine from the hydronephrotic kidney to evaluate renal dysfunction accompanying urinary tract obstruction. Moreover, it was also examined whether it is possible to predict functional recovery of the hydronephrotic kidney on the basis of relation between these indices and pre- and postoperative changes in renal dimercaptosuccinic acid (DMSA) uptake rate. The values of beta 2-MG, alpha 1-MG, NAG and albumin in urine from the renal pelvis were high in 48%, 50%, 75% and 83% of the patients, respectively. Among the patients of one year and up, those with low preoperative DMSA uptake rate tended to have high values of beta 2-MG, alpha 1-MG and NAG. On the contrary, albumin level was high in 78% of patients who had good preoperative DMSA uptake rate. With respect to the relation between pre- and postoperative changes in DMSA uptake rate and each index, beta 2-MG and alpha 1-MG were high in 73% and 62% of patients who exhibited a marked increase in postoperative DMSA uptake rate. In patients without a remarkable change in DMSA uptake rate before and after surgery, on the other hand, the values of these were high only in 25% and 36%.(ABSTRACT TRUNCATED AT 250 WORDS)

Acetylglucosaminidase↗
PubMed1992

[Effect of unilateral hydronephrosis upon contralateral renal growth].

UNLABELLED: To evaluate the effect of hydronephrosis on the growth of contralateral normal kidney, following experiment was designed and performed. EXPERIMENT: Three to four weeks old S-D rats weighing 80-90 g were used. The kidney development of these rats is considered to be roughly equivalent to that of a one year old child. Those rats were divided into three groups: (1) left nephrectomy (group N), (2) left ureteral ligation (group H), and (3) sham operation (group S). Bromodeoxy uridine (BrdU) was administered intraperitoneally on the 1st, 3rd, 5th, 7th and 14th days after operations. One hour after injection of BrdU, right kidneys were removed and wet weight and labelling index (LI) of BrdU were calculated. Compensatory renal growth of right kidneys was observed in both group H and group N on and after 1st or 3rd day. In group N, the growth was accompanied by cellular proliferation, while in group H, hypertrophy was the major finding for up to 5th day. From 7th day on, when significant disorders became histologically evident in the left hydronephrotic kidneys, cell proliferation was also observed in the group H. The above results indicate that compensatory renal growth occurred in the contralateral normal kidney after unilateral ureteral ligation. Although proliferation of right renal tubular cells were recognized when significant tubular and interstitial damage of the left hydronephrotic kidneys were observed, hypertrophy was a major finding in an early stage. We suggest that these results were attributed to (1) reduction of nephron triggered to proliferate tubular cells and (2) the existence of hydronephrotic kidney inhibited tubular cell proliferation.

Animals↗
PubMed1991

[The effect of pyeloplasty on renal function in children with unilateral ureteropelvic junction obstruction. Investigation of the split renal function using DMSA renal uptake rate].

Pre- and post-operative changes of renal function in twenty children (10 were younger than 2 years old) with unilateral hydronephrosis due to ureteropelvic junction obstruction were studied on the basis of DMSA renal uptake rate. A marked increase in DMSA renal uptake rate was observed in thirteen cases (65%) after pyeloplasty on the obstructed side. Among them eight children were younger than 2 years old. In 6 children younger than 2 years old, a remarkable increase of DMSA renal uptake rate after reconstructive operation was recognized not only on the obstructed side but also on the contralateral normal side. These tendency could not be observed in those older than 2 years old. These results suggest that, in the young children, the obstructed kidney inhibits the contralateral normal and compensatory renal growth, and that the relief of obstruction eliminates this inhibition and causes the renal growth spur in a normal kidney. We conclude that it is essential to correct unilateral ureteropelvic junction obstruction before two years of age if an improvement of renal function not only on the obstructed side but also on the normal side is to be expected.

Adolescent↗
PubMed1990

[Urinary incontinence in children with primary vesicoureteral reflux--urinary incontinence and function of refluxing kidney].

The interrelation among urinary incontinence (nocturnal enuresis, urge incontinence), history of urinary tract infection and renal function was investigated in 153 children with primary vesicoureteral reflux who were more than three years old. Of them, 98 children (64%) had the chief complaint of urinary tract infection (UTI) and 43 children (28%), urinary incontinence. Of the children whose chief complaint was UTI, 44 (45%) had incontinence. Thus, 87 children (57%) with VUR had urinary incontinence. Almost all the children who had urinary incontinence and no previous UTI had good renal function. Renal dysfunction was found in children with previous UTI history. These studies on children with primary VUR more than three years old indicate that, although urinary incontinence could be a factor for recurrence of UTI and a probable cause of worsening of renal function, there is no direct correlation between urinary incontinence and renal dysfunction accompanied by VUR.

Adolescent↗
PubMed1990

[Renal function in children with solitary kidney].

Renal function of eighteen children with solitary kidney (14 congenital and 4 acquired) was assessed using DMSA renal uptake rate and urinary excretion of alpha 1-MG, beta 2-MG, NAG and microalbumin. Seven of the cases were associated with vesicoureteral reflux (VUR) and two with congenital hydronephrosis. These anomalies have been already treated surgically before entering this study. DMSA renal uptake rate of 8 children was the same as that of the controls (51.8 +/- 3.7%; mean +/- SD). However, the uptake rate of 10 cases were more than 2SD below the mean of the controls. In five of them, including two children with no other urinary tract anomaly, the uptake rate was less than 70% of the mean of the controls. Half of 14 children evaluated with alpha 1-MG showed high values. In 6 of these 7 cases, DMSA renal uptake rate was more than 2SD below the mean of the controls. Urinary microalbumin was not correlated with urinary alpha 1-MG or DMSA renal uptake rate. Three of 4 children with high values of urinary microalbumin were more than 10 years old. Nine of 12 children evaluated with all the indices mentioned above showed high values of urinary alpha 1-MG and/or microalbumin. Low DMSA renal uptake rate was revealed in 7 out of these 9 children including two cases without urinary tract anomaly. These results indicate that, in the cases with solitary kidney even though no other urinary tract anomaly is recognized, renal overload may have already developed in early life.

Acetylglucosaminidase↗
PubMed1990

[Evaluation of renal function in children with primary VUR up to two years old].

The function of 99 refluxing kidneys of 61 children up to two years old at the time of diagnosis was evaluated by 99mTc-DMSA renoscintigraphy, urinary beta 2-microglobulin (beta 2-MG), alpha 1-microglobulin (alpha 1-MG) and N-acetyl-beta-D-glucosamidase (NAG). High grade reflex (grade IV, V) was found in 45% of the cases. 76%, 51% and 92% of the cases showed abnormally high value of urinary beta 2-MG, alpha 1-MG and NAG, respectively. These results indicate that they have already had tubular dysfunction at the time of diagnosis. DMSA renoscintigraphy of 82 refluxing kidneys of 49 children was performed. Of these, 48% had renal scar and 28% had serious renal dysfunction [DMSA uptake rate less than 18%]. 10-20% of low grade VUR had less than 18% DMSA uptake rate. Two patterns were noticed in the group in which urinary beta 2-MG ranged 0.33-1.0. One was characterized by good bilateral renal function with slight tubular damage and the other serious renal dysfunction with fixed tubular damage. No remarkable recovery of the renal function was noticed after antireflux operation in the second pattern cases. In many cases, in which urinary beta 2-MG was more than 1.0, improvement of DMSA uptake rate was noticed after antireflux operation.

Child, Preschool↗
PubMed1990

[Estimation of glomerular filtration rate from the urinary excreted contrast medium concentration].

In the animal experiments, glomerular filtration rate (GFR) values were estimated from the urinary response to the intravenously administrated iopamidol. By introducing some reasonable assumptions, mass balance equations about the contrast medium were transformed and GFR was defined as the ratio of logarithm of urinary concentration by time. Urinary concentrations were determined by measuring the photodensity on the X-ray film of urine specimens. Obtained values of GFR were well fitted to those obtained by the analysis of the plasma disappearance curve. The advantage of this method is that measurement of urinary volume is not necessary.

Animals↗
PubMed1989

[Evaluation of renal scarring in children with primary VUR by 99mTc-DMSA renoscintigraphy].

Renal scarring in 271 kidneys of 172 children with primary vesicoureteral reflux (VUR) was evaluated by 99mTc-DMSA renoscintigraphy. 58% of refluxing kidneys were with renal scar by the initial DMSA renoscintigraphy. Only 52% of these kidneys showed good correlation between the findings on IVP and DMSA renoscintigram. Of the 144 refluxing kidneys with normal IVP, 41% had renal scarring on DMSA renoscintigram. DMSA renoscintigram revealed widespread renal scarring in 28% of kidneys with only calyceal clubbing and in 60% of those with segmental cortical thinning on IVP. It is realized that IVP was an in-sensitive method to evaluate renal scarring of refluxing kidneys and such kidneys with segmental renal scar on IVP accompanies more widespread scar on DMSA renoscintigram. These cases were allocated to 2 age groups, younger than 3 years and older than 4 years. In the former group less than 10% of kidneys with low grade VUR and about 40% with high grade UVR had widespread renal scarring. On the contrary, in the latter group severe renal scar was recognized in more than 20% of kidneys with low grade VUR and in about 60% with high grade UVR.

Adolescent↗
PubMed1986

[Radiation-induced meningioma--a case report].

A case of meningioma following irradiation for a tumor of the third ventricle is reported. A four year old girl was admitted complaining of headache and vomiting. The pneumoventriculography revealed marked hydrocephalus and a mass lesion at the third ventricle. Under the diagnosis of a tumor of the third ventricle, ventriculo-atrial shunt and radiation therapy were performed. Totally, 4170 rad irradiation was directed from left temporal area through a single portal. Though she had no complaints for fourteen years, at the age of eighteen, she was admitted complaining of right hemiparasis and general convulsion. CT scan and left carotid angiogram revealed a left fronto-temporal tumor diagnosed as meningioma. Histological examination showed transitional type meningioma. The post-operative course was uneventful, and discharged without neurological sign except for slight right hemiparesis. A review of available literature revealed about 150 cases of post irradiated meningiomas. However, there were only 18 cases of meningiomas following irradiation for the treatment of brain tumors. These reported cases were also discussed.

Adolescent↗
PubMed1984

[The effect of prazosin hydrochloride on cerebral vasospasm--an experimental study].

The effect of Prazosin, a new alpha-receptor blocking agent, to release and prevent experimental cerebral vasospasm induced by oxyhemoglobin was investigated. In the first group of cats Prazosin was administered one hour before the induction of vasospasm by oxyhemoglobin, and thirty minutes after the application of oxyhemoglobin in the second group. Doses of 0.5 mg/kg and 0.1 mg/kg were subjected to both groups respectively. In the third group, the divided administration of Prazosin was done; 0.05 mg/kg was given one hour before and two hours after the application of oxyhemoglobin. In the first group, prevention of vasospasm was observed. In the second group, induced vasospasm was released from three hours after the administration of Prazosin. These effects were seemed to be dependent on doses of Prazosin. In the third group, more constant prevention of vasospasm was observed than the former groups. The possible mechanism of preventing and releasing effect of Prazosin on cerebral vasospasm was discussed.

Animals↗