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Biomedical subjects

R Rabinowitz

Publications and source records attributed to R Rabinowitz.

At least 19 recordsLinked to original sources

The effect of xenoantisera on T-lymphocyte functions in the absence of complement.

An attempt was made to determine whether xenoantisera can detect functional receptors on mouse T lymphocytes. Antisera were raised by immunizing rabbits with BALB/c thymus cells, boiled thymus homogenate, brain homogenate or bone marrow cells. Following heat inactivation these antisera were absorbed with mouse kidney and liver homogenates, and studied for their effect, in the absence of C', on the activity of murine T lymphocytes. Rabbit anti-bone marrow serum (RAB) had no effect on the mixed lymphocyte reaction (MLR) nor on cell-mediated lysis (CML). In contrast, rabbit anti-thymus serum (RAT) and anti-boiled thymus serum (RABT) inhibited strikingly, the MLR, CML, and the response to concanavalin A and phytohemagglutinin. Rabbit anti-brain serum (RABR) caused a marked increase of the proliferation of lymphocytes both in the presence or absence of various stimuli and had no effect on the CML. Absorption experiments indicated that a number of antigens are involved in the inhibitory activity of RAT. Antibodies to a T cell specific antigen interfere with the response of T lymphocytes to mitogenic stimuli, while the activity of cytotoxic T cells is inhibited by antibodies to a determinant shared by B and T lymphocytes.

Absorption

Artifactual urethral stricture in male child.

Artifactual urethral obstruction at the suspensory ligament of the penis may be produced if the penis is left in its normally dependent position during a urethrogram. We present 2 such cases to re-emphasize this phenomenon so that caution is taken in interpreting distal bulbous urethral strictures.

Child

Primary massive reflux in children.

Over a ten-year period, of more than 1,000 children whose primary vesicoureteral reflux was treated surgically, there were 54 children with 80 single ureters which were massively dilated. Primary reconstruction with ureteral tailoring was done in 25 ureters with a success rate of 92 per cent. Forty-five ureters were temporarily diverted because of uncontrolled infection and/or azotemia. In almost half of these instances, temporary diversion resulted in improvement in ureteral caliber to such an extent that nontailored reimplantation could be performed with a success rate of 87 per cent. Six kidneys were removed and four have been maintained in the diverted state with severe renal dysplasia. Eighty-eight per cent of the refluxing megaureters were reconstructed with a success rate of 89 per cent.

Child

Dopamine-beta-hydroxylase activity in serum of patients with hepatic damage.

1. The activity of dopamine-beta-hydroxylase (DBH) was assayed in the serum of 102 patients, mostly with varying degrees of hepatic dysfunction. 2. DBH activity was not elevated in those with liver disorder and did not correlate with serum bilirubin, transaminase, lactic dehydrogenase, alkaline phosphatase or creatine phosphokinase. 3. It is concluded that the liver is not necessarily involved in the inactivation of DBH.

Dopamine beta-Hydroxylase

Surgical management of massive neurogenic hydronephrosis.

Permanent urinary diversion has been the standard recommended treatment of massive dilatation of the upper tracts in the child with neurogenic vesical dysfunction. Reimplantation of relatively normal caliber ureters into neurogenic bladders has been shown to be effective. However, attempts to save urinary diversion in 39 neurogenic megaureters have been unrewarding, with the salvage rate of 15 per cent, and 64 per cent have been diverted permanently. Upper tract decompression by continuous or intermittent catheterization, nephrostomy or end cutaneous ureterostomy was used in this series. When ureteral caliber responded to decompression a reasonable success rate from non-tailored reimplantation may be anticipated. However, in those instances in which ureteral caliber failed to respond or when tailoring or ureteral caliber was done in conjunction with reconstruction the success rate was much lower.

Adolescent

Upper tract management when posterior urethral valve ablation is insufficient.

Of 105 boys with posterior urethral valves managed during a 10-year period most were managed by primary valve ablation. However, 39 of these boys required concomitant or additional procedures to 71 massively dilated ureters because of azotemia, infection and/or progressive upper tract deterioration. In 17 boys 25 ureters could be reconstructed primarily by varying degrees of ureteral tailoring. When there was severe infection, azotemia and/or doubt as to the function of the affected renal unit, staged reconstruction was initiated by cutaneous ureterostomy. One-fourth of these ureterostomy diverted children died of azotemia despite free urinary drainage. Those who went on to have staged reconstruction, despite multiple surgical procedures, retained intact urinary systems with acceptable function.

Bacterial Infections

Hyperchloremic acidosis and imperforate anus.

The predominant electrolyte imbalance associated with enterourinary fistulas is hyperchloremic acidosis. The mechanism is the absorption of urinary electrolytes across the colonic mucosa. One of the genitourinary associated anomalies of a high imperforate anus is a rectourinary fistula. There have been 5 cases of hyperchloremic acidosis as a complication of an imperforate anus with a rectourinary fistula reported in the literature to date. An additional case is presented with a clinical analysis of the previously reported cases. The important factors in the development of hyperchloremic acidosis in patients with an imperforate anus are 1) the presence of a rectourinary fistula, 2) an initial diverting colostomy permitting a long segment of colonic mucosa for the absorption of urinary electrolytes, 3) distal urinary tract obstruction allowing significant volumes of urine to flow into the colonic segment and 4) the presence of urinary tract infection contributing to the urinary obstruction. Management should consist of vigorous electrolyte therapy, decreasing the retrograde flow of urine into the colon by temporary catheterization and early repair of the fistulous tract.

Acidosis

Leaking mycotic aneurysm of renal artery in a child.

A case of staphylococcal endocarditis, complicated by a leaking mycotic aneurysm of the right artery in a boy is presented. An emergency nephrectomy was lifesaving. The clinical course and pathology are discussed and the literature is reviewed.

Adolescent

Salvaging the iatrogenic megaureter.

From 1965 through 1975 we treated 30 children with 44 megaureters that were acquired after the reimplantation of normal caliber ureters. One-third of these children had had at least 2 prior surgical procedures on the bladder and 30 per cent were azotemic. There was no difference in the salvage rate of acquired megaureters with reflux versus obstruction. Temporary proximal diversion often was useful in the short-term management. Only 70 per cent of the patients completed reconstruction and only 70 per cent of those reconstructed were successful by all parameters. Ureteral tailoring was generally a necessary adjunct to successful repeat reimplantation. There was a significantly lesser salvage rate in those ureters that had had more than 1 prior surgical procedure. The best results were obtained when all surgical maneuvers were done transvesically because there was a significant incidence of acquired atonic vesical dysfunction after repeated dissections in the perivesical area.

Adolescent

Mechanisms involved in the weak alloimmunogenicity of Thy-1 on mouse brain.

Immunization of mice with allogeneic brain homogenates fails to elicit an appreciable response to the Thy-1 antigen. The aim of the present study was to determine the mechanism of the low immunogenicity of allogeneic brain. Immunization of C3H mice with freshly prepared mixtures of AKR/J thymus cells with either AKR/J or C3H brain homogenates elicited a primary response to the Thy-1.1 antigen as effectively as immunization with AKR/J thymus cells. When the mixtures were incubated overnight prior to injection, only AKR/J brain homogenate but not C3H brain homogenate abrogated the capacity of AKR/J thymus cells to elicit an anti-Thy-1.1 response. Suppressor T cells did not seem to be responsible for the inability of brain to elicit an anti-Thy-1 response, as mice that received cyclophosphamide 2 days prior to injection of brain did not produce Thy-1 antibodies. Antigenic competition also did not seem to be the cause for the weak immunogenicity of Thy-1 on brain, as mixtures of thymus and brain were capable of eliciting a primary response. When spleen cells from mice hyperimmunized against Thy-1 were transferred to normal syngeneic mice, subsequent immunization with brain homogenate was capable of eliciting Thy-1 antibodies. These results indicate that Thy-1 on brain may resemble a hapten, in being incapable of eliciting a primary immune response, but behaves like a complete antigen in boosting a secondary response.

Animals

Surgical treatment of the massively dilated primary megaureter in children.

From 1964 to 1975, of 83 children with primary megaureter 33 had unilateral and 8 bilateral massively dilated ureters that required surgical treatment, and of these 73% had febrile infection, 5% were septic and 10% were azotaemic. Surgical treatment consisted of ureteric reimplantation with excision of the atonic distal segment, preceded by diversion when indicated. Tailored reimplantation was successful in 98% of ureters and non-tailored reimplantation was uniformly unsuccessful. All failures were successfully corrected by tailored reimplantation. Thus the requirements for successful surgical management of massive ureteric dilatation in children secondary to an atonic ureteric segment are excision of the atonic segment, transvesical or extravesical tailoring of the ureter and reimplantation.

Adolescent

Urinary tract reconstruction in prune belly syndrome.

Fifteen boys with prune belly syndrome cared for over a ten-year period required surgical treatment because of uncontrolled infection and/or progressive azotemia. Five died of renal dysplasia. Primary or staged reconstruction resulted in significant improvement when ureteral reimplantation was combined with tailoring of ureteral caliber.

Abdominal Muscles

The influence of etiology on the surgical management and prognosis of the massively dilated ureter in children.

The massively dilated ureter is a major therapeutic challenge that faces the pediatric urologist. In those instances when more conservative measures, such as control of infection or correction of the primary pathology, have failed or are likely to fail surgical treatment must be directed to the massively dilated ureter itself. The goals of reconstructive procedures are the elimination of residual urine, effective ureteral peristalsis, and efficient and/or urgent urinary drainage. We encountered these clinical settings in 244 children with 366 massively dilated ureters from 1965 through 1974. The underlying pathologic processes included primary megaureter, refluxing megaureter, posterior urethral valves, ureteral duplication with upper role ectopic ureterocele or lower pole refluxing megaureter, simple ureterocele, ureterovesical junction obstruction, neurogenic vesical dysfunction, prune belly syndrome and acquired (iatrogenic) megaureter. The results of several reconstructive techniques are reviewed according to the excretory urogram, cystogram, renal function studies and the presence or absence of urinary infection. Analysis of the results with respect to the underlying pathologic entity responsible for the massively dilated ureter indicates that the etiology is a crucial factor in determining whether surgical treatment should be recommended and the type of surgical treatment that will most likely be successful.

Abdominal Muscles