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Biomedical subjects

R Rabinowitz

Publications and source records attributed to R Rabinowitz.

At least 37 records · Page 2Linked to original sources
PubMed1998

Outcome of patients with vesicoureteral reflux after renal transplantation: the effect of pretransplantation surgery on posttransplant urinary tract infections.

OBJECTIVES: We evaluated the relation of vesicoureteral reflux, pretransplant nephrectomy, and prior ureteral reimplant with respect to posttransplant urinary tract infection and graft survival. METHODS: From 1984 to 1995, 820 renal transplants were performed. Thirty-six (4%) patients had documented vesicoureteral reflux. The patients were divided into three groups: Group I, N = 10 (28%) underwent ureteral reimplantation prior to transplantation; Group II, N = 8 (22%) had bilateral nephrectomy prior to transplantation; and Group III, N = 18 (50%) had persistent reflux at the time of transplantation. RESULTS: Graft survival at 3 years was 50% (18/36). Patient survival was 94% (34/36). The overall incidence of urinary tract infection was 56% (20/36). Complicated urinary tract infection was seen in 28% (10/36) and uncomplicated urinary tract infection in 47% (17/36) of the patients. The incidence of both complicated and uncomplicated urinary tract infection was lower in Group I. However, graft survival was lower in Group I patients. Overall graft survival was significantly lower in patients with vesicoureteral reflux compared with the rest of the group. CONCLUSIONS: The incidence of urinary tract infection did not appear to be altered significantly whether the patients had bilateral nephrectomy or persistent vesicoureteral reflux. However, those patients who had ureteral reimplantation had fewer episodes of infection. Nephrectomy prior to transplantation should be performed selectively.

Adolescent↗
PubMed1998

Prenatal diagnosis of duplex system hydronephrosis: effect on renal salvage.

OBJECTIVES: To determine if prenatal identification of significant renal duplication anomalies affects the management of the patient or the clinical outcome. METHODS: This is a retrospective review of 79 consecutive children with severe hydronephrosis involving a duplex renal collecting system, identified by either prenatal ultrasound (asymptomatic), or symptoms, most often urinary tract infection, but also including abdominal mass, hematuria, or incontinence. An individualized combination of voiding cystourethrogram, ultrasound, intravenous urogram, and nuclear renal scan was used to assess anatomy and function. Ablation of the involved segment was carried out if no or extremely poor function was identified; a definitive reconstructive procedure was elected in the face of easily measureable function. Outcome was determined clinically and by repeat imaging. RESULTS: There was no difference in the rate of renal segment salvage between the prenatally and clinically diagnosed groups. Of the cases analyzed, 20/79 were prenatally identified, of which 13/20 (65%) were reconstructed; 59/79 were identified on clinical grounds, of which 34/59 (58%) were reconstructed. One patient in the prenatal salvage group underwent removal of the affected kidney 5 years later. Another, in the clinical salvage group, underwent a successful secondary procedure for closure of a ureteral fistula. All others have shown improved function, drainage, or both in follow-up. No secondary procedures have been required for the ablation group to date. Follow-up ranges from 4 months to 12 years. CONCLUSIONS: Prenatal identification of significant duplex system hydronephrosis does not improve the rate of renal segment salvage, as determined by standard radiographic means, compared to later identification on clinical grounds. The decision for reconstruction versus ablation in significant duplex system hydronephrosis can be made on the basis of function alone.

Adolescent↗
PubMed1998

Abdominoscrotal hydrocele in infancy.

Abdominoscrotal hydrocele is an uncommon clinical entity. Fewer than 200 cases have been reported in the literature, only two of which described bilateral involvement. We present five cases of abdominoscrotal hydrocele occurring in infancy, three of which revealed bilateral disease. The first case represents the youngest patient ever reported with this condition and the first reported with secondary bilateral upper tract dilatation. The historical background, pathophysiology, diagnosis, and treatment are reviewed.

Abdomen↗
PubMed1998

Buccal mucosal grafts for urethral reconstruction.

OBJECTIVES: Patients requiring urethral reconstruction but who have a paucity of usable genital tissue present a considerable technical challenge. Herein we report the experience of three centers in the use of buccal mucosa for urethral replacement. METHODS: From 1991 to 1996, 22 urethral reconstructions were completed using a graft of buccal mucosa. Eighteen of 22 patients had previously failed hypospadias repairs, while three had bulbar urethral stricture and one had penile carcinoma. Grafts were taken from either the inner cheek or the lower lip, and seven were used as a combined graft. Onlay grafts were used in 6 cases and tubularized grafts in 16 cases. RESULTS: Two patients developed complications at the donor site. Nine of 22 patients had complications of the urethroplasty-two had meatal stenosis, four developed a urethral fistula, and three developed urethral stricture. All complications have been managed successfully to date. CONCLUSIONS: Buccal mucosa is an excellent source of graft material for urethral replacement in complex urethroplasties. It is readily available, in abundant supply, and has physical properties beneficial to free graft survival.

Adolescent↗
PubMed1998

Activated human T-cells bestow T-cell antigens to non-T-cells by intercellular antigen transfer.

The mechanism of the appearance of T-cell antigens on B-cells, following in vitro activation of peripheral blood lymphocytes, was analyzed using the following model: Purified T-cell suspensions were activated by exposure to phytohemagglutinin (PHA) for 3 days, and then incubated for one hour in the presence of cells of either Raji or K562 cells. The expression of T-cell antigens on the cell lines was determined using immunofluorescent F(ab)2 fragments of monoclonal antibodies (mAbs). Following exposure of the CD19+ Raji cells to activated T lymphocytes, 87.6% of the CD19+ cells coexpressed CD2. A large proportion of the CD19+ cells also expressed CD4, CD5, and CD8 antigens. Similar results were obtained with Raji cells that were prelabeled with calcein AM. In Raji cells, which were rendered CD5+ following incubation with activated T cells, only a negligible level of CD5 mRNA was detected with a sensitive RT-PCR technique, probably attributable to contamination with T cells. K562 cells incubated with activated T cells acquired CD2 but not the CD4 and CD8 antigens. Exposure of either Raji or K562 cells to mAb against CD58 inhibited the transfer of CD2. The present study indicates that following their activation, T-cells gain the capacity to transfer T-cell antigens to non-T cells and that CD2 and CD58 molecules are involved in this process.

Antibodies, Monoclonal↗
PubMed1998

The effect of dental alloys on mouse lymphocyte subpopulations.

The aim of the present study was to determine the effect of nickel-containing alloys on lymphocyte subsets in an experimental setting. Plates of alloys containing nickel (Ceramalloy, Talladium, Cerillium, Rexillium) or gold (Orion) were implanted subcutaneously into mice. The levels of CD4+ and CD8+ T-lymphocyte subpopulations and of Smig+ B lymphocytes were determined at various intervals following implantation, using monoclonal antibodies and flow cytometry. No changes were detected in the proportion of the lymphocyte subsets tested. One month after implantation, the mean fluorescence intensity of CD4, CD8 or Smig, in the peripheral blood lymphocytes (PBL) of the nickel alloy-implanted animals, was significantly higher than that prior to this procedure. Only a mild increase in CD4 and CD8 was noted after implantation of the gold alloy. The observed effects are most likely attributable to the surgical trauma, and do not indicate that nickel-containing dental alloys influence T cell subsets in this murine model.

Animals↗
PubMed1998

Assessment of first-trimester nuchal translucency by daily reference intervals.

Increased fetal nuchal translucency measured in the first trimester is associated with an elevated frequency of chromosomal abnormalities, yet no reference intervals for transvaginal sonographic measurements of fetal nuchal translucency in that period of development have been established. The aim of the present cross-sectional study was to construct appropriate gestational age-specific reference intervals for nuchal translucency. Transvaginal ultrasound was used in 180 normal pregnant women between 9 and 14 weeks of gestation. Reference intervals were constructed by the parametric method. These reference intervals were then compared to the traditional threshold value of 3 mm, when applied to 287 women scheduled for amniocentesis or chorionic villus sampling (CVS). Both methods had the same sensitivity, 85.7%, and negative predictive value, 99.6%, in predicting fetal chromosomal abnormalities. However, the specificity of the gestational age-related reference intervals tended to be higher than that of the 3-mm threshold: 94.6% vs. 87.9%. The positive predictive value of the former method was higher than that of the 3-mm threshold: 28.6% vs. 15%. The increased specificity and positive predictive value of these reference intervals are of particular importance when applied to women under the age of 35 years. In those women, the finding of an abnormally thick nuchal translucency can lead to the performance of amniocentesis or CVS. Therefore, using these reference intervals instead of the traditional 3-mm threshold may save a significant number of unnecessary invasive procedures.

Adult↗
PubMed1998

Lymphocyte subsets in human tonsils: the effect of age and infection.

The aim of the present study was to determine the effect of repeated tonsillitis on the development of lymphocyte subsets in the tonsils and among peripheral blood lymphocytes (PBL) of children. Subsets of T- and B cells were analyzed in the tonsils and in PBL of patients undergoing tonsillectomy for idiopathic tonsillar hypertrophy, recurrent tonsillitis, or tonsillar hypertrophy and tonsillitis. The majority of the CD4+ cells in the tonsils displayed the CD45RO+ phenotype, while the majority of those in the PBL displayed the CD45RA+ phenotype. Likewise, the proportion of CD45RO+CD8+ cells was higher in the tonsils than among PBL. The proportion of CD4 cells expressing the CD45RO marker increased with age among PBL, but not in the tonsils. B cells, detected by their CD19, CD20, and CD21 markers, were three times more abundant in the tonsils than in the PBL. The proportion of CD38+ cells showed a negative correlation with age, both in the tonsils and among PBL. Among PBL a striking age-related reduction was seen in the proportion of CD19+, CD21+ and CD38+CD21+ B cells. In contrast, in the tonsils age-related changes could be detected only in the proportion of CD21+CD38+ cells. No difference among patients with various clinical diagnoses was detectable in any of the T- and B cell subsets in the tonsils and PBL. Thus, lymphocyte subsets evolve independently in the tonsils and peripheral blood, with the repeated antigenic challenge of tonsillar lymphocytes not influencing circulating memory cells.

ADP-ribosyl Cyclase↗
PubMed1998

Hereditary CD4+ T lymphocytopenia.

Two siblings suffering from mental retardation, progressive bronchiectasis, extensive warts, and persistent hepatitis B are described. The propositus also had an unusual physiognomy and non-specific colitis. Both patients had a marked decrease in the population of CD4+ helper T cells.

Adolescent↗
PubMed1998

Enhanced lymphoid cell recovery after bone marrow transplantation: correlation with the presence of costimulatory antibodies in serum.

We describe a patient with T cell deficiency who underwent bone marrow transplantation (BMT) from an HLA-identical brother. The patient's white blood cell count recovered with exceptional rapidity post-BMT: after 7 to 9 days it rose sharply to 98x10(9) cells/L, 76% of which were mononuclear leukocytes. It then decreased, and a second peak was observed 250 days post-BMT. Lymphocytes from both peaks displayed a phenotype of mature T cells together with characteristics of a constitutively activated state; that is, they 1) exhibited high levels of tyrosine-phosphorylated T cell receptor (TCR) zeta chain, 2) spontaneously secreted IL-2, 3) expressed activation specific cell surface markers, and 4) were unresponsive to in vitro stimuli. The increased cell counts in both peaks correlated with the presence of anti-lymphocytic antibodies in the patient's serum, which reacted with peripheral blood lymphocytes (PBLs) both from the donor and from unrelated individuals. These antibodies were present before BMT and reappeared post-BMT. Variable number tandem repeats analysis revealed that the patient's PBLs were chimeras for up to 2 years post-BMT. This finding could explain the newly synthesized post-BMT anti-lymphocytic antibodies and the appearance of the second WBC peak during that period. The patient's anti-lymphocytic antibodies displayed costimulatory activity, enhancing the in vitro proliferation of normal T cells suboptimally activated via the TCR. The unique characteristics of these antibodies could explain the enhanced T cell recovery observed post-BMT as well as the constitutive activation state of these cells. Furthermore, such antibodies may eventually facilitate development of a therapeutic method for inducing enhanced post-BMT recovery.

Adolescent↗
PubMed1997

Use of enzyme replacement therapy for Gaucher disease during pregnancy.

OBJECTIVE: To date there has been little published experience with enzyme replacement therapy in pregnant women with symptomatic type I Gaucher disease. STUDY DESIGN: We describe six patients, including three with repeated early pregnancy loss, five of whom successfully carried pregnancies to term; the last pregnancy was terminated because of pulmonary hypertension. RESULTS: All pregnancies were uneventful and five resulted in healthy newborns. CONCLUSION: We concluded that in patients with Gaucher disease of childbearing age,for whom obstetric complications are an important symptom of the disease, pregnancy is not contraindicated (unless there is evidence or suspicion of pulmonary hypertension) and treatment should not be interrupted because the clinical improvement engendered by enzyme replacement therapy is conducive to fewer complications during pregnancy and delivery and post partum.

Abortion, Habitual↗
PubMed1997

Urinary interleukin-8/creatinine level as a predictor of response to intravesical bacillus Calmette-Guerin therapy in bladder tumor patients.

PURPOSE: Our purpose was to determine whether urinary interleukin-8 (IL-8) levels could be used to predict a tumor-free response to intravesical bacillus Calmette-Guerin (BCG) therapy in bladder cancer patients. MATERIALS AND METHODS: A total of 46 patients with superficial bladder cancer underwent an initial 6-week course of intravesical BCG therapy after transurethral resection. Voided urine samples were collected immediately before BCG instillations 1 and 6. Urine samples were centrifuged at 1,500 rpm for 8 minutes, and the supernatant was stored at -20 C. An enzyme-linked immunosorbent assay technique was used to measure urinary IL-8 levels. The Jaffé method was used to measure urinary creatinine. Results were expressed as the IL-8/creatinine ratio. Patients were followed with cystoscopy and urinary cytology every 3 months to detect bladder tumor recurrence. RESULTS: IL-8/creatinine ratios were measured in 31 patients before BCG therapy and were undetectable in 15. After 5 weeks of intravesical BCG therapy, IL-8/creatinine ratios fell in 27 patients (59%), were unchanged in 10 (22%) and rose in 9 (19%). Mean followup was 20.9 months (range 3 to 48). There was no association between the direction of change in IL-8/creatinine ratio and response to intravesical BCG therapy (p = 0.5). CONCLUSIONS: Urinary IL-8 levels obtained before intravesical BCG therapy and after instillation 5 of BCG were not helpful in predicting tumor recurrences in bladder cancer patients.

Adjuvants, Immunologic↗
PubMed1997

Late presentation of cryptorchidism: the etiology of testicular re-ascent.

PURPOSE: We reviewed the records of 21 boys who had 23 previously documented descended testes that reascended and who underwent orchiopexy during a 2-year period. MATERIALS AND METHODS: We retrospectively reviewed a 2-year experience in 103 boys (115 undescended testes) who underwent orchiopexy in 1988 and 1989. RESULTS: In our 2-year experience 21 of the 103 boys with undescended testes had multiple recorded confirmations of testicular descent in the past. Of the boys 40% had previously been examined in the office or with general anesthesia by a pediatric urologist or pediatric surgeon for another reason, and 40% had a nurse or physician parent. Surgery was performed at ages 5 to 14 years, an average of 2 years after the initial presentation with reascent. Human chorionic gonadotropin was unsuccessful in causing testicular descent. There was no correlation with a patent processus vaginalis and no association with adhesions. The testis was located in the superficial inguinal pouch in the majority of patients, and the gubernacular attachment was in an abnormal location in all and ectopic in half of the cases. CONCLUSIONS: Our observations confirm that the etiology of this condition is a missed diagnosis at a younger age. The testis is undescended but almost completely descended. With somatic growth the distance between the terminal portion of the gubernaculum of the apparently descended testis and the scrotum increases, making the diagnosis more obvious. The potential for this condition makes it mandatory that intrascrotal testicular location be confirmed by periodic physical examination through puberty.

Age Factors↗
PubMed1997

The appearance of the CD4+CD8+ phenotype on activated T cells: possible role of antigen transfer.

Stimulation of peripheral blood lymphocytes (PBL) with phytohemagglutinin (PHA) strikingly increased the proportion of CD4+CD8+ cells. Highly purified CD4+ and CD8+ lymphocyte populations cultured in the presence of PHA consistently failed to coexpress the CD8 and CD4 markers. Similarly, exposure of highly purified CD4+ cells to PHA and recombinant interleukin-2 resulted in augmented expression of CD25 but failed to induce the expression of CD8. When purified preparations of either CD4+ or CD8+ cells were activated separately for 3 days and incubated together for an additional 5 h, a considerable proportion of CD4+CD8+ cells was found in the mixture. Cycloheximide treatment did not prevent the appearance of the CD8 marker on CD4 cells. CD4+CD8+ cells isolated from PBL exposed for 3 days to PHA lost their CD8 antigenicity within 24-48 h in the absence of PHA. Increased levels of soluble CD4 and CD8 antigens were found in supernatant fluids of PHA-stimulated cells. T cells failed, however, to bind soluble markers even after prolonged incubation in the presence of supernatant fluids. Our studies show that activation of CD4+ cells per se does not elicit the CD4+CD8+ phenotype and that soluble T cell markers do not bind to T cells. Rather, it seems that direct cell-cell contact is required for the transfer of CD8 molecules from CD8+ cells to the membrane of CD4+ cells.

Biological Transport↗
PubMed1997

Neuroanatomical aspects of mydriatic action of morphine in rats.

Morphine causes mydriasis in rats. In order to investigate whether this effect is due to direct inhibition of preganglionic pupilloconstrictor neurons in the Edinger-Westphal nucleus (EWN), we injected opiate agonists into the EWN in male albino Charles River rats. Bilateral stereotactic microinjections of morphine (10, 20, 30, 40 micrograms/side) inhibited spinal nociceptive reflexes and caused pronounced catalepsy, but had no effect on pupillary size. The powerful opiate agonist, fentanyl, also elicited analgesia and catalepsy, when given in doses of 5 and 10 micrograms/side, but no dose of fentanyl up to 10 micrograms/side induced mydriasis. Naloxone (10 micrograms/side), given into the EWN, effectively antagonized inhibition of the tail-flick response induced by subcutaneously administered morphine (30 micrograms/kg), but had no effect on the cataleptic and mydriatic actions of systemic morphine. These results indicate that, in the rat, morphine-induced mydriasis is not accounted for by a direct action on the EWN.

Analgesics, Opioid↗
PubMed1997

Digoxinlike immunoreactive factor isolated from human pleural fluid is structurally similar to digoxin.

To further define the chemical structure of human endogenous digoxinlike immunoreactive factors (DLIF) we used human pleural effusions as a source of the substance. Digoxinlike immunoreactive factor activity was detected by radioimmunoassay in the pleural fluid of each of four patients; average concentration was 0.35 ng/mL. The chemical profile of DLIF was determined by initial extraction and concentration of DLIF by ion exchange chromatography followed by reverse phase-high-pressure liquid chromatography (RP-HPLC) separation and purification. Using high-pressure liquid chromatography cochromatography of DLIF, together with several radioactively marked glycosides, we observed a single peak of DLIF activity that was chromatographically identical to digoxin. The present study further supports the recent finding that DLIF is related structurally to the cardiac glycosides, and for the first time it has been proven that DLIF is present in pleural fluids.

Cardenolides↗
PubMed1997

Penile block timing for postoperative analgesia of hypospadias repair in children.

PURPOSE: It has been well established that a dorsal penile nerve block immediately after surgery decreases postoperative pain in children undergoing hypospadias repair. However, to our knowledge the efficacy of a penile block immediately before versus immediately after surgery for postoperative pain control has not been previously studied in such children. MATERIALS AND METHODS: We evaluated 98 healthy boys 6 months to 12 years old undergoing hypospadias repair. General anesthesia was induced and maintained in a standard fashion. Patients were randomly assigned to receive a penile block with the same total dose of bupivacaine at the completion of surgery, before the incision or before and at the completion of surgery. No other analgesic was administered intraoperatively. Pain was assessed using a modified objective pain-discomfort scale at 15 minutes, and 3, 12 and 24 hours after surgery. The number of doses of acetaminophen required to control postoperative pain was also recorded. RESULTS: Pain scores were defined in a range of 0-no pain to 6-greatest pain. During recovery median pain scores in the 30, 36 and 32 boys who received a penile block after, before, and before and after surgery were 3, 1.5 and 0 at 15 minutes; 2.5, 1 and 0 at 3 hours; 3, 2 and 0 at 12 hours; and 1, 0 and 0 at 24 hours, respectively. There was no difference in acetaminophen doses required 15 minutes and 3 hours postoperatively in the 3 groups. By 12 hours after surgery the number of acetaminophen doses required for pain control was significantly lower in the before and after, and before groups than in the after group. By 24 hours boys in the before and after group required significantly fewer doses of analgesics than those in the after and before groups. There was no statistically significant difference between the after and before groups. CONCLUSIONS: Two penile blocks performed at the beginning and conclusion of hypospadias repair, respectively, provide better postoperative pain control than 1 penile block done before or after surgery (p < 0.05). These patients require less analgesic than those who receive a penile block only before or only after surgery.

Analgesia↗