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Biomedical subjects

J Rehman

Publications and source records attributed to J Rehman.

At least 19 recordsLinked to original sources
PubMed2001

Dual-organ ablative surgery using a hand-assisted laparoscopic technique. A report of four cases.

In clinical situations where more than one procedure is required, a properly positioned hand-assist device can be used to obviate the need for two large incisions. We present four cases of hand-assisted laparoscopic nephrectomy combined with a simultaneous second organ extraction. Each of the four primary procedures, as well as one of the four secondary procedures, was performed using a hand-assisted laparoscopic technique. In two cases, the secondary procedure was performed with an open surgical technique through the hand-assist incision. For the remaining secondary procedure, we used a laparoscopically assisted technique.

Aged↗
PubMed2001

Significant physiological roles of ancillary penile nerves on increase in intracavernous pressure in rats: experiments using electrical stimulation of the medial preoptic area.

The objectives of this work were to evaluate the contributions of the ancillary penile nerves to penile erection in male rats in vivo. We investigated the effects of unilateral and bilateral transection of the cavernous nerve (main penile nerve) on the increase in intracavernous pressure (ICP) following electrical stimulation of the medial preoptic area (MPOA) in male rats in vivo. After unilateral or bilateral transection of the cavernous nerve (main penile nerve), the ICP responses showed decreases of 28% and 55%, respectively compared to those ICP responses before transection. In other words, even after bilateral transection of the cavernous nerve, significant increases in the ICP response following central stimulation were observed. In contrast to these findings, the ICP response was completely eliminated following bilateral pelvic nerve transection. These data suggested that the ancillary penile nerves, which originate from the major pelvic ganglia, have a complementary role to the cavernous nerves in the autonomic motor innervation of the penis.

Animals↗
PubMed2001

Laparoscopic bilateral hand assisted nephrectomy for autosomal dominant polycystic kidney disease: initial experience.

PURPOSE: The laparoscopic technique for bilateral nephrectomy in patients with autosomal dominant polycystic kidney disease is technically difficult. The procedure may be more acceptable if alterations to the technique made it safer and easier to perform. We describe our initial experience with, and the feasibility and potential benefits of hand assisted laparoscopic nephrectomy for approaching these large kidneys in patients with autosomal dominant polycystic kidney disease. MATERIALS AND METHODS: This approach was successfully applied in 3 patients with end stage renal disease due to autosomal dominant polycystic kidney disease. After obtaining transumbilical pneumoperitoneum ports were placed in the umbilicus (12 mm.), sub-xiphoid in the midline (12 mm.) and subcostal in the midclavicular line on each side (12 mm.). The table was tilted 40 degrees away from the planned side of initial nephrectomy with the patient in the half lateral position. A 7 cm. midline incision was made that incorporated the umbilical port and a commercially available hand assistance device was positioned. One surgeon hand was inserted into the abdomen to serve as a retractor/blunt dissector, while the other operated the electrosurgical instruments. The right hand was inserted for left nephrectomy and the left hand was inserted for right nephrectomy. The laparoscope was passed via the sub-xiphoid port and the instruments were placed through the ipsilateral subcostal laparoscopic port. Nephrectomy was completed and the specimen was removed through the hand port incision by draining the cysts as they were exposed to view via the midline incision. When dissection was difficult, an additional port was placed in the anterior axillary line at the umbilical level. Some cysts were ruptured or aspirated to decrease overall kidney size and make extraction possible via the 6 to 7 cm. midline incision. RESULTS: All procedures were successfully completed. Mean operative time for bilateral hand assisted laparoscopic nephrectomy was 5.5 hours (range 4.5 to 6.6). Estimated blood loss was 200 cc or less. Patients resumed oral intake on postoperative day 1. The mean amount of parenteral analgesics required postoperatively was decreased. Mean hospital stay was 4.3 days but it was 3 days when considering nephrectomy only. Patients returned to normal activity after an average of 2 weeks. There was sustained resolution of preoperative discomfort based on pain analog scales. At 1 month or less all patients recorded absent pain. They uniformly noticed improved preoperative pulmonary and gastrointestinal symptoms CONCLUSIONS: Hand assisted laparoscopic nephrectomy in patients with autosomal dominant polycystic kidney disease makes bilateral nephrectomy a reasonable option. The bilateral procedure may be performed as rapidly as laparoscopic only, unilateral nephrectomy in these cases. The advantages of the hand assisted approach include using tactile sensation to facilitate dissection, rapid blunt finger dissection, hand retraction and the application of immediate tamponade when needed. This procedure provides the benefits of minimal intraoperative blood loss, minimal postoperative pain, brief hospital stay and rapid convalescence in this group of patients at high risk.

Adult↗
PubMed2001

Missed anterior crossing vessels during open retroperitoneal pyeloplasty: laparoscopic transperitoneal discovery and repair.

PURPOSE: Extrinsic ureteropelvic junction obstruction due to anterior crossing segmental renal vessels is present in more than 50% of patients in adulthood. In this situation the ureter must usually be dismembered and transposed anterior to the crossing vascular structures, where it is anastomosed to the renal pelvis. Via the open retroperitoneal approach there may be a limited view of the anterior surface of the ureteropelvic junction and, hence, anterior crossing vessels may possibly be missed. We describe 2 patients with ureteropelvic junction obstruction in whom anterior vessels were missed during open retroperitoneal repair. Laparoscopic transperitoneal secondary pyeloplasty with posterior displacement of the crossing renal vessel was performed in each case. MATERIALS AND METHODS: Two patients presented with symptomatic congenital ureteropelvic junction obstruction after failed endopyelotomy in 1 and failed open retroperitoneal procedures in both. Preoperatively spiral computerized tomography angiography with a ureteropelvic junction protocol revealed crossing vessels in the 2 cases. This finding was confirmed at transperitoneal laparoscopic pyeloplasty. The ureter and renal pelvis were transposed anterior to the crossing vessels and 2 rows of running sutures were placed to complete the anastomosis. RESULTS: The 2 laparoscopic procedures were completed successfully. The anterior crossing vessels were preserved in each case. Currently the patients are asymptomatic and furosemide washout renal scan was normal. CONCLUSIONS: Spiral CT angiography reliably delineates the renal vascular anatomy in patients with ureteropelvic junction obstruction. This study may be valuable before planned open retroperitoneal ureteropelvic junction obstruction repair. Laparoscopic pyeloplasty may successfully manage anterior crossing vessels associated with secondary ureteropelvic junction obstruction.

Adolescent↗
PubMed2000

Leukocyte adhesion molecule expression and T cell naïve/memory status following isoproterenol infusion.

This study examined adhesion molecules on peripheral leukocytes following a 30-min infusion of the beta-adrenergic agonist isoproterenol in 23 healthy subjects. In response to isoproterenol, the number of CD8 +CD62L- T cells and both CD62L+ and CD62L-natural killer (NK) (CD3 CD16+ 56+) cells increased markedly in circulation (p < 0.001). In addition, the surface density of CD62L was significantly lower on both CD8+ and CD4+ T cells (p < 0.001). Plasma levels of soluble CD62L remained unchanged, arguing against an isoproterenol-induced shedding of L-selectin. In contrast to CD62L, the surface density of the beta2 integrin LFA-1 (CD11a) was higher on circulating lymphocytes (p < 0.001) (but not monocytes or lymphocytes) post-infusion. Isoproterenol also led to a mobilization of memory/activated CD8+CD29high T cells (p < 0.01), but had no significant effect on the number of circulating CD8+ CD45RA+ CD62L+ naïve T cells. beta blockade with the non-specific antagonist propranolol eliminated these isoproterenol-induced effects.

Adrenergic beta-Agonists↗
PubMed2000

Experimental hyperprolactinemia in a rat model: alteration in centrally mediated neuroerectile mechanisms.

INTRODUCTION: The purpose of this study was to induce hyperprolactinemia in adult male rats and determine its effect on the central and peripheral mediated neurogenic as well as myogenic mechanisms of erectile function/dysfunction in a rat model. The use of penile reflexes in awake animals was used to test the effect of both central and peripheral mechanisms. Electrical stimulation of the cavernous nervous was used to test peripheral neural function and intracorporal injection of papaverine was used to test the intactness of the corporal smooth muscles. These mechanisms were further explored by administration of testosterone. METHODS: Eighteen Fisher-344 200-250 g rats aged 10 weeks were used in this study. Group 1 (n = 6) hyperprolactinemia was induced with subcutaneous (SQ) injection of 5 mg rat prolactin (NIDDK-r-PRL-B-7, biopotency 25 IU/mg) in two divided doses daily for 1 week. Testosterone propionate 100 mg/kg dissolved in sesame oil was given intramuscularly on day 1 (weekly dose). Group 2 (n = 6) control animals received SQ injection of vehicle twice daily and sesame oil I/M on day 1. Group 3 (n = 6) received testosterone propionate. Penile reflexes (erections, cups, flips and clusters) were assessed prior to induction (x 3) of and following one-week state of hyperprolactinemia (day 5, 6 and 7). All animals were trained three times before recording the penile reflexes. The penile reflexes being averaged to give a single composite score for each animal. All animals underwent dissections that isolated the cavernosal bodies and cavernosal nerves. Cavernous nerves were activated and intracorporal pressures were recorded at increasing current magnitude (range 0.5-10 mA). Following that corporal smooth muscle reactivity was determined by increasing injection of papaverine (100-3000 microg). Concentration response curves (CRCs) were then generated by plotting percent change (fractional change to make standardized comparison) to increasing neurostimulation or papaverine concentrations at half-log increments. Serum prolactin was determined by rPRL radioimmunoassay Kit-Amersham while serum testosterone was determined Testosterone ELISA Kit-Neogen. RESULTS: Penile reflexes were normal in all groups at the start of experiment but after 1 week of hyperprolactinemia, reflexes were totally abolished in hyperprolactinemia rats (Group 1) and unchanged in Groups 2 and 3. Response to cavernous nerve activation and resulting rise in intracorporal pressure to increasing current (range 0.5-10 mA) were statistically non-significant in any groups. Similarly the intracorporal pressure response to pharmacologic erection induced by papaverine (100-3000 microg) were also non-statistically significant in any groups. Serum prolactin level in all rats receiving prolactin were > 500 ng/ml and the rat group receiving testosterone, serum level were > 20 x higher than the control rat. CONCLUSIONS: This approach allowed more clear separation of central and peripheral mechanism of erection. This study shows a central neurological effect of hyperprolactinemia on erectile function. Hypogonadism does not seem to contribute to the impaired penile reflexes as documented by replacement of testosterone did not recover the centrally mediated penile reflexes. Lowered serum testosterone is secondary phenomenon. These observations may have important implications for the understanding, the mechanism and treatment of men with hyperprolactinemia as well as future research in this field.

Animals↗
PubMed2000

Laparoscopic nephropexy.

Although there has long been debate about the existence of nephroptosis, contemporary radiologic and biochemical studies confirm its existence. Both percutaneous and laparoscopic operations are available for fixing the kidney, with high early success rates. Objective documentation of the diagnosis is mandatory. Further studies with validated quality-of-life and pain questionnaires are needed to determine the long-term success of nephropexy.

Abdominal Muscles↗
PubMed2000

Laparoscopic ureteral surgery.

The use of laparoscopy for ureteral surgery, currently in its relative infancy, is critically reviewed here as an alternative to traditional open and endoscopic methods. The technical aspects of laparoscopic ureteral surgery, clinical and experimental experience to date, and recent advances in anastomotic and substitutive technology are discussed.

Humans↗
PubMed1999

Increased production of antigen-specific immunoglobulins G and M following in vivo treatment with the medicinal plants Echinacea angustifolia and Hydrastis canadensis.

A number of immunomodulatory effects have been attributed to the medicinal plants Echinacea angustifolia and Goldenseal (Hydrastis canadensis); however, little is known about whether treatment with these plants can enhance antigen-specific immunity. We investigated the antigen-specific in vivo immunomodulatory potential of continuous treatment with Echinacea and Goldenseal root extract over a period of 6 weeks using rats that were injected with the novel antigen keyhole limpet hemocyanin (KLH) and re-exposed to KLH after the initial exposure. Immunoglobulin production was monitored via ELISA continuously over a period of 6 weeks. The Echinacea-treated group showed a significant augmentation of their primary and secondary IgG response to the antigen, whereas the Goldenseal-treated group showed an increase in the primary IgM response during the first 2 weeks of treatment. Our results suggest that medicinal plants like Echinacea or Goldenseal may enhance immune function by increasing antigen-specific immunoglobulin production.

Adjuvants, Immunologic↗
PubMed1999

Modification of sexual behavior of Long-Evans male rats by drugs acting on the 5-HT1A receptor.

Modulation of the sexual behavior of male rats by the anxiolytic buspirone (S-20499) and its analog gepirone were compared to the effects of 8-OH-DPAT (or DPAT, a selective 5-HT1A reference agonist), and BMY-7378 (a selective 5-HT1A partial agonist). Long-Evans rats were used; modulation of copulatory behavior and alteration of penile reflexes were examined. Modulation of copulatory behavior was assessed by three indices: frequency and length of intromission, and latency of ejaculation. DPAT, at doses of 1-8 mg/kg, reduced these three indices in a time dependent manner such that the effects peaked at 45 min and normalized at 90 min. The dose-effect relationship (assessed 45 min after DPAT injection) is bell-shaped with an ED50 approximately 1 mg/kg on the ascending limb of the curve. The effects of buspirone (2 mg/kg) and gepirone (2 mg/kg) on copulatory behavior were indistinguishable from control. BMY-7378 alone and in combination with these other 5-HT1A agonists reduced copulatory behavior, though not statistically significant. Penile reflexes, including number of erections, cups and flips, were inhibited by these agents: DPAT>buspirone>gepirone (inactive at 2 mg/kg). Furthermore, the latency period to erection was at least doubled by DPAT (2 mg/kg). Buspirone and gepirone, however, reduced the latency period to erection. BMY-7378 inhibited penile reflexes when administered alone and even more in combination with DPAT or buspirone. Two butyrophenone analogs, spiperone (a 5-HT1A and dopamine D2 antagonist) and haloperidol (a D2 antagonist), were also tested for their interaction with DPAT. Both of these drugs (at 0.25 mg/kg, 60 min after administration) reduced all indices of penile reflexes and copulation. Furthermore, in combination with DPAT (2 mg/kg, 45 min), the effects were synergistic such that sexual activity came nearly to a standstill. These opposing effects on putatively brain originated copulatory behavior and spinal mediated penile reflexes indicate that the effects of buspirone and DPAT on sexual behavior in the male rat may be possible at different parts of the central nervous system. If a tentative shared target site by DPAT and buspirone is the 5-HT1A receptor, than the same 5-HT receptor sub-type at different locations (brain, raphe nuclei, spinal cord and autonomic ganglia) may modulate rat sexual behavior in opposing ways.

8-Hydroxy-2-(di-n-propylamino)tetralin↗
PubMed1999

Nonselective beta blockade attenuates the recruitment of CD62L(-)T lymphocytes following exercise.

Exercise induces a selective redistribution of CD62L(-) T lymphocytes. This study examined the effects of beta adrenergic receptor blockade on this phenomenon. Twelve healthy men were exercised to exhaustion on a treadmill prior to and following 1 week of treatment with the nonselective beta antagonist propranolol or the beta1 selective antagonist metoprolol. Dynamic exercise resulted in a significant lymphocytosis (p < 0.001). CD8(+)CD62L(-) T cells showed a greater than 3-fold increase in response to exercise (p < 0.001) as compared to CD8(+)CD62L(+) T cells, which showed a more modest increase. Treatment with the nonselective beta antagonist propranolol significantly attenuated the preferential increase of circulating CD8(+)CD62L(-) lymphocytes (p = 0.01) but had no effect on CD8(+)CD62L(+) T cells. Treatment with the beta1 selective antagonist metoprolol did not affect the response of either subset. Our findings replicate a prior study indicating that CD62L expression influences T lymphocyte trafficking in response to exercise and extends those findings by showing that this phenomenon is mediated, in part, via the beta2-adrenergic receptor.

Adrenergic beta-Antagonists↗
PubMed1999

The reported sex and surgery satisfactions of 28 postoperative male-to-female transsexual patients.

From 1980 to July 1997 sixty-one male-to-female gender transformation surgeries were performed at our university center by one author (A.M.). Data were collected from patients who had surgery up to 1994 (n = 47) to obtain a minimum follow-up of 3 years; 28 patients were contacted. A mail questionnaire was supplemented by personal interviews with 11 patients and telephone interviews with remaining patients to obtain and clarify additional information. Physical and functional results of surgery were judged to be good, with few patients requiring additional corrective surgery. General satisfaction was expressed over the quality of cosmetic (normal appearing genitalia) and functional (ability to perceive orgasm) results. Follow-up showed satisfied who believed they had normal appearing genitalia and the ability to experience orgasm. Most patients were able to return to their jobs and live a more satisfactory social and personal life. One significant outcome was the importance of proper preparation of patients for surgery and especially the need for additional postoperative psychotherapy. None of the patients regretted having had surgery. However, some were, to a degree, disappointed because of difficulties experienced postoperatively in adjusting satisfactorily as women both in their relationships with men and in living their lives generally as women. Findings of this study make a strong case for making a change in the Harry Benjamin Standards of Care to include a period of postoperative psychotherapy.

Adaptation, Psychological↗
PubMed1999

Intraoperative electrical stimulation of cavernosal nerves with monitoring of intracorporeal pressure in patients undergoing nerve sparing radical prostatectomy.

OBJECTIVE: To explore the utility of intraoperative cavernosal nerve stimulation in facilitating atraumatic nerve dissection during radical prostatectomy, and thus help predict postoperative erectile function. PATIENTS AND METHODS: Fourteen patients (aged 51-72 years) underwent nerve-sparing radical retropubic prostatectomy (NSRRP); 10 were potent before surgery (group 1), and four had erectile dysfunction (group 2). A multi-acquisition system (MacLab/8e) with a Macintosh computer was used for real-time display and recording of intracavernosal pressure (ICP) during surgery. Nerves were stimulated with a bipolar probe (monophasic rectangular pulses, 10 mA, 20 Hz, 0.22 s) before and after removal of the gland. The follow-up consisted of interviews with patients and their partners' 12-18 months after treatment. RESULTS: The mean (sem) basal ICP of 8. 0 (2.0) cmH2O remained unchanged during nerve dissection. The mean increase in ICP during electrical stimulation was >50 cmH2O in seven potent patients (group 1) and was sustained as long as the nerve was stimulated. Postoperatively, these seven patients reported erections sufficient for sexual intercourse. However, the three remaining patients in group 1 had pressure rises of <30 cmH2O, of whom two reported partial erections and one reported total impotence postoperatively. The recovery time for erectile function was 6-12 months after surgery. Two patients from group 2 had transient increases in ICP to <40 cmH2O; one had an increase to 20 cmH2O and one had no response at all. All four patients remained totally impotent postoperatively. There were no complications. CONCLUSIONS: Intraoperative electrical stimulation of the cavernosal nerves with ICP monitoring before and after NSRRP is a safe and reliable method for documenting nerve continuity and its functional status. Patients who have normal preoperative erectile function and show an adequate rise in ICP upon electrical nerve stimulation during NSRRP will almost certainly be potent after surgery. This tool may be used to facilitate atraumatic nerve dissection during NSRRP.

Aged↗
PubMed1999

Formation of neoclitoris from glans penis by reduction glansplasty with preservation of neurovascular bundle in male-to-female gender surgery: functional and cosmetic outcome.

PURPOSE: During male-to-female gender reassignment surgery we used an abdominal pedicled inverted penile skin technique to create a vagina and extra folds of skin to create a clitoral hood. Although patients had orgasms with that technique, there was a general request for the placement of a sensate, erectile clitoris. Therefore, in 10 such patients undergoing transsexual surgery a neoclitoris was fashioned from the glans penis. Surgical technique and results are described. MATERIAL AND METHODS: From 1980 to 1995, 57 male-to-female gender surgeries were performed at our university center. In the last 10 such patients undergoing transsexual surgery a neoclitoris was created. Glans volume is reduced to match that of a normal size clitoris and the entire length of the dorsal neurovascular bundle is preserved. The neoclitoris is placed through a buttonhole in the newly constructed introitus. There was minimal bleeding from the bundle intraoperatively. RESULTS: In 8 of 10 patients the neoclitoris remained intact postoperatively with good sensation to touch, vibration and light pressure (sexual sensation). The cosmetic and functional appearance was that of a normal clitoris, and patients were satisfied. In 2 patients the results were not satisfactory because of necrosis of the neoclitoris. CONCLUSIONS: This technique has excellent functional and cosmetic results in the majority of patients. Preservation of the somatic, tactile and vibratory sensation of the neoclitoris is surgically practical, and can afford the patient the possibility of a more functional outcome of gender reassignment surgery.

Adult↗
PubMed1999

Pathophysiology of Erectile Dysfunction.

Physiology of erection and pathophysiology erectile dysfunction is reviewed. Analysis is obtained from basic and clinical research including animals studies, anatomical studies, and molecular and cellular research on corporal tissue obtained during penile prosthesis implantation. Supraspinal influences and spinal influence on penile erection has been learned from spinal cord injury patient. Corporal smooth muscle relaxation of penile arteries and corpus cavernosum leads to penile erection, results from parasympathetic/nonadrenergic noncholinergic neural pathway activation and simultaneous inhibition of sympathetic outflow. Anatomical studies taught understanding of the mechanism for restriction of blood outflow from the corpora cavernosa. The change of smooth muscle tone has emerged as a key factor in erection and detumescence. Many independent factors converge on the modulation of corporal smooth muscle tone. Neuronal and local neurotransmitter effects via gap junction, potassium channels, and calcium channel. A nitric oxide/cyclic guanosine monophosphate mechanism as well as cyclic aminomonophosphate has an important role in mediating the corporal smooth muscle relaxation necessary for erectile function. Erectile dysfunction can be due to vasculogenic, neurogenic, hormonal, veno-occlusive, psychogenic and/or pharmacogenic factors as well as alterations in the nitric oxide/cyclic guanosine monophosphate (cGMP) or cyclic aminophosphate (cAMP) pathway or other regulatory mechanisms including gap junction or ionic channel resulting in an imbalance in corporal smooth muscle contraction and relaxation. Our present knowledge of the hemodynamics, functional anatomy, neurophysiology, and neuropharmacology of penile erection and dysfunction at the cellular and molecular level has led to better understanding of physiology and pathophysiology of erectile dysfunction.

Journal Article↗
PubMed1998

Experimental autoimmune myocarditis produced by adoptive transfer of splenocytes after myocardial infarction.

One possible mechanism for neurohumoral activation after myocardial infarction may be the generation of an immune response against cardiac self-antigens. We hypothesize that if there is a T cell-mediated reaction to self-antigens, the transfer of splenic lymphocytes from postinfarct rats into syngeneic rats with normal hearts should result in a T cell-mediated autoimmune myocarditis in the healthy syngeneic rats. Rats were killed 6 weeks after coronary ligation. Splenocytes from animals with large and small infarcts were purified from spleens, activated with concanavalin A, and injected in varying doses into normal syngeneic rats. These recipient rats were killed 6 weeks later, and histopathological studies were performed. Our results demonstrate in vivo evidence of lymphocyte-mediated myocardial injury by adoptive transfer of sensitized lymphocytes from rats who developed congestive heart failure after acute myocardial infarction. The amount of infiltrate and necrosis in the recipient rats appeared directly related to the size of the infarct from the donor rats. This suggests that larger infarcts lead to a greater inflammatory response as well as a greater propensity for alteration of cardiac surface antigens or the emergence of previously sequestered antigens. None of the other organs (kidney, liver, lung, or brain) had evidence of infiltrates. Two-dimensional echocardiography did not reveal systolic dysfunction. This study provides direct evidence of autoimmune myocardial injury produced by adoptive transfer of concanavalin A-activated splenocytes after myocardial infarction. We propose that neurohumoral activation early in the postinfarction period triggers a series of specific inflammatory and immunological events that lead to formation of specific clones of T cells. When these are activated and transferred into normal rats, cardiac-specific cellular infiltration occurs, occasionally accompanied by myocardial necrosis. This model should help to further explore the link between neurohumoral activation after myocardial infarction and the subsequent immune alterations that might be associated with the development and/or progression of congestive heart failure. Additionally, this might be a useful model in which to study other immune-mediated cardiomyopathies.

Adoptive Transfer↗