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Biomedical subjects

M A Bazeed

Publications and source records attributed to M A Bazeed.

At least 19 recordsLinked to original sources
PubMed2004

Effects of Schistosoma haematobium infection on drug-metabolizing enzymes in human bladder cancer tissues.

The mixed function oxidase system includes the phase I drug oxidation proteins e.g. aryl hydrocarbon hydroxylase (AHH), N-nitrosodimethylamine-N-demethylase I (NDMA-dI) and cytochrome b5 which metabolize most carcinogens and xenobiotics into less and/or more active intermediates. These were determined in human bladder tissues diagnosed as bladder cancer only (10 samples) and bladder cancer associated with Schistosoma haematobium (12 samples) and normal bladder tissues (12 samples). In addition to the above enzymes, agents involved in Phase II drug metabolism e.g. glutathione and glutathione S-transferase as well as free radicals (detected as thiobarbituric acid-reactive substances, TBARS) were also determined in these tissues samples. AAH and NDMA-dI, cytochrome b5, and glutathione S-transferase activity decreased by 42, 28, 47 and 32%, respectively, in human bladder cancer tissues. In bladder cancer tissues associated with S. haematobium infection NDMA-dI and GST activity decreased further by 65 and 56%, respectively, whereas AHH activity increased by 50% and levels of reduced glutathione also increased by 43% in cancer tissue and by 29% in schistocome infected bladder cancer tissue. The level of free radicals also increased significantly (by 57%) in infected bladder cancer tissue but not at all in non-infected cancer tissue. Alterations in the activity of phase I and II of drug-metabolizing enzymes in human bladder tissues as a result of S. haematobium infection may therefore change the bladder's capacity to detoxify many endogenous compounds and may also potentiate the deleterious effects of bladder carcinogens, (e.g. N-nitrosamines) which are known to be present in relatively large quantities in the bladder of patients with schistosomiasis. The present study thus provides new insights into mechanisms for the genesis of bladder cancer initiated in association with schistosomiasis.

Adult↗
PubMed2004

Late renal functional and morphological evaluation after non-operative treatment of high-grade renal injuries in children.

OBJECTIVE: To assess the long-term results in children with high-grade renal trauma who were managed without surgery, as such treatment was initially successful but little is known about the late ipsilateral renal function and morphology. PATIENTS AND METHODS: The study included 13 children (nine boys and four girls; mean age 8 years, sd 5) with high-grade renal injury who were managed without surgery between 1997 and 2001, and followed for a mean (sd, range) of 3 (2, 0.5-7) years. The trauma was caused by a motor-car accident in five and falling from a height in eight children, and was on the right in 10 and on the left in three. There was gross and microscopic haematuria in 10 and three patients, respectively. The trauma was graded according to the American Association for Surgery of Trauma, with grades III, IV and V renal injury in six, four and three children, respectively. All patients were treated initially by observation; one required super-selective embolization because of continuing haemorrhage. Three children with progressive urinary extravasation were treated with a percutaneous tube drain and JJ stent for 6 weeks. Patients were discharged after a mean (sd) hospital stay of 9 (6) days. Ultrasonography then showed resolving haematoma in all patients with a mean (sd) size of 7 (2) cm(2). At the last follow-up patients were re-evaluated by a clinical examination, renal scintigraphy and computed tomography angiography. RESULTS: None of the children was hypertensive nor had any abnormality on urine analysis; all had normal serum creatinine levels, and scintigraphy and angiography showed normal contralateral kidneys in all. Ipsilateral abnormalities were detected in 12 patients, and included a single scar in five, multiple scars in six and a cystic lesion with multiple septa in one. There was no vascular complication or hydronephrosis, and no significant functional loss, with all affected kidneys having a split function of 41-50% at the last follow-up. CONCLUSION: Although there is no late functional loss there are residual morphological changes in almost all children with high-grade renal injury. This study provides objective support for the non-operative management of high-grade renal injury in children, but a prolonged follow-up is warranted to assess the risk of progression of these abnormalities.

Child↗
PubMed2004

Comprehensive analysis of tubularized incised-plate urethroplasty in primary and re-operative hypospadias.

OBJECTIVE: To retrospectively review our experience of the tubularized incised-plate (TIP) urethroplasty over the last 4 years. PATIENTS AND METHODS: From 1998 to December 2001, 133 patients (mean age 7 years, sd 4, range 1-22), had a TIP urethroplasty by one surgeon for primary (103) and re-operative (30) hypospadias; the defects included 106 (79%) distal and mid-shaft, and 27 (21%) posterior shaft. The neourethra was covered by a subcutaneous flap in 66 (50%) patients or by corpus spongiosa (spongioplasty) in 31 (23%), with no cover in the remaining 36 (27%). In the last 20 patients (15%) a modified meatoplasty was used; the site and size of the new meatus was predetermined on the glans around a suitable catheter before any incision. Urethral stents were not used after repair in 39 (29%) patients, and regular meatal dilation was used only in patients with voiding difficulty and obvious tendency to stenosis. The presence of complications requiring re-operation and overall general appearance were recorded. RESULTS: The mean (sd) follow-up was 10 (5) months; there were 24 complications in 20 patients (15%), including a small fistula in 12 (9%), complete disruption of the repair in 4 (3%), meatal stenosis in seven (5%) and neourethral stricture in one (0.8%). Complications were not significantly different between primary and re-operative cases, and unaffected by the use of the stents. On univariate analysis complications were significantly higher with running than interrupted sutures, in repairs in the first 2 years of the study, in patients with posterior hypospadias, and in those with no neourethral coverage. However, the last two factors were the only significant independent risk factors in a multivariate analysis. Regular urethral dilatation was indicated in 43 patients (32%). Modified meatoplasty was associated with a significantly lower requirement for regular dilatation (P < 0.05) and no meatal stenosis. In the 113 complication-free patients the operation gave an excellent cosmetic appearance with a vertical slit meatus on the tip of conical glans in 110 (97%); there was slight meatal retraction in the remaining three patients. CONCLUSION: The TIP repair is a reliable method for treating both distal and proximal penile shaft hypospadias, is suitable for both primary and re-operative cases, and is more versatile than other repairs. Covering the neourethra with a flap or spongioplasty significantly improves the results. Regular urethral dilatation is required in a third of patients but modified meatoplasty obviates the need for regular dilatation and eliminates the risk of meatal stenosis.

Adolescent↗
PubMed2001

Changes in the expression of cytochrome P450 2E1 and the activity of carcinogen-metabolizing enzymes in Schistosoma haematobium-infected human bladder tissues.

The bioactivation of N-nitrosamines and polycyclic aromatic hydrocarbons (PAHs) is mediated primarily by the mixed-function oxidase system, which includes dimethylnitrosamine N-demethylase I, arylhydrocarbon [benzo(a)pyerne] hydroxylase, cytochrome P450, cytochrome b(5), and ethoxycoumarin deethylase. Most of carcinogens and xenobiotics are conjugated and detoxified by phase II drug-metabolizing enzymes such as glutathione S-transferase. The present study showed the influence of Schistosoma haematobium on the activity of the above-mentioned enzymes in 13 schistosome-infected human bladder tissues compared with those of 15 schistosome-free samples. The contents of cytochrome P450 and cytochrome b(5) were increased in the bladder tissues by 48 and 69%, respectively. Moreover, the activities of dimethylnitrosamine N-demethylase I and arylhydrocarbon hydroxylase, ethoxycoumarin O-deethylase, ethoxyresourfin O-deethylase, and pentoxyresorufin O-pentoxyresorufin were increased by 75, 159, 49, 63 and 44%, respectively. The signal intensity for cytochrome P450 2E1 was greatly increased over the control. Also, the activity of glutathione S-transferase was increased by 89%. On the other hand, the activity of glutathione reductase and the level of reduced glutathione were decreased by 40 and 57%, respectively. Interestingly, the level of free radical, thiobarbituric acid reactive substance, was increased in the schistosome-infected human bladder tissues by 125%. The present study clearly demonstrated that S. haematobium changes the activity of carcinogen-metabolizing enzymes. We conclude that S. haematobium could enhance the carcinogenicity of polycyclic aromatic hydrocarbons (e.g. benzo(a)pyrene) and N-nitrosamines (e.g. dimethylnitrosamine) through induction of their corresponding bioactivating enzymes in human bladder tissues.

7-Alkoxycoumarin O-Dealkylase↗
PubMed1993

A new use of ureteroscopy.

Failure to deflate a Foley balloon is a rare but annoying complication. We describe 2 simple techniques to solve this problem.

Catheterization↗
PubMed1989

Xanthogranulomatous pyelonephritis in bilharzial patients: a report of 25 cases.

The preoperative diagnosis of xanthogranulomatous pyelonephritis is difficult due to its similarities to other renal diseases. Also, its relationship to bilharziasis to the best of our knowledge has never been studied. We attempted to explore these 2 problems by reviewing the files and pathological slides of 25 patients whose diagnosis was proved histopathologically to be xanthogranulomatous pyelonephritis. We concluded that the diagnosis of xanthogranulomatous pyelonephritis preoperatively still is difficult. We believe that bilharziasis is an etiologic factor for the disease by increasing the incidence of urinary tract obstruction, infection and stone formation. We plan to study this relationship further by examining the freshly removed kidneys immunohistologically.

Adult↗
PubMed1988

In vitro chemosensitivity testing of renal cell cancer. Short-term culture technique.

In an attempt to solve the problem of chemosensitivity testing of renal cell carcinoma in vitro, a modified short-term culture technique was developed. The kinetic study of hypernephroma cells and normal renal cells showed that the uptake of H3-uridine and H3-thymidine is at its maximum after eighty hours. The effect of doxorubicin, cisplatinum, vinblastine, and mitomycin C in different concentrations was tested. Tumors generally showed more resistance than sensitivity. Some tumors showed sensitivity to one or more drugs, but no one drug was persistently effective in all tumors. Our short-term culture technique solved the discrepancy between cell kinetics and test duration found in the Volm test and the problem of nongrowth in the clonogenic assay.

Carcinoma, Renal Cell↗
PubMed1988

Effect of lectins on KK-47 bladder cancer cell line.

The effect of three lectins, Ricinus communis agglutinin (RCA II), concanavalin agglutinin (ConA), and wheat germ agglutinin (WGA), on KK-47 bladder cancer cell line was studied, RCA II showed effective inhibition of H3-uridine and H3-thymidine uptake by KK-47. ConA showed a stimulatory effect in all three concentrations used. WGA also showed stimulatory effect, but it was less pronounced than ConA.

Carcinoma↗
PubMed1986

Local excision of urothelial cancer of the upper urinary tract.

In 9 of 93 patients (9.7%) with urothelial cancer of the upper tract (7 renal pelvis tumors, 3 ureteral tumors), conservative surgery was employed using a free peritoneal autotransplant for replacement of the renal pelvis in 5 kidneys. Absolute indications for conservative surgery were solitary kidneys/nonfunctioning contralateral kidneys in 4 patients and bilateral tumors in 1 patient. Local recurrences developed 1-3 years after operation in 4 of 6 kidneys (3 patients), 3 of which had grade-2 and grade-3 primary lesions. All patients were treated successfully by repeated local excision. In the presence of a normal contralateral kidney, local tumor excision was done electively in 4 patients (3 low-grade/low-stage lesions, 1 high-risk patient), none of these patients developed recurrences. Two patients died without evidence of tumor recurrence, 7 patients are free of tumor at an average follow-up of 23 months (range 5-65 months). Local excision of urothelial cancer should be considered not only for solitary kidneys, bilateral tumors and cases with renal failure, but also for low-stage/low-grade localized tumors, leaving the patient better prepared for later treatment of a possible recurrence due to the well recognized chance of a multiplicity of tumors in time and space.

Adult↗
PubMed1986

Effect of lectins on 3H-uridine and 3H-thymidine uptake by cultured renal cell carcinoma and normal renal cells.

The effect of lectins on cultured renal cell carcinoma and normal renal cells was studied. Ricin II showed effective inhibition of 3H-uridine and 3H-thymidine uptake by renal cell carcinoma and normal renal cells in all cases. Normal renal cells were more resistant to the inhibitory effect of ricin II as compared to renal cell carcinoma. Concanavalin agglutinin and wheat germ agglutinin led to stimulation of 3H-uridine and 3H-thymidine uptake by renal cell carcinoma and normal renal cells at low concentrations (0.2 micrograms/ml), and to suppression at high concentrations (2 and 20 micrograms/ml).

Carcinoma, Renal Cell↗
PubMed1986

Functional pattern of sacral root stimulation: III. Erection.

The mechanism of canine penile erection was studied in 6 'chronic' and 15 'acute' male dogs by means of sacral root stimulation combined with pharmacologic studies. The basic mechanism of erection cannot be explained by a pure increase in arterial perfusion of the cavernous spaces due to neural vasomotor regulation. The vasomotor mechanism, whether pure arteriolar vasodilation, or venous drainage impairment, or secondary to as yet undefined behavior of the corporal smooth muscle, can be activated by stimulation of the parasympathetic outflow. Those preganglionic fibers may synapse to noncholinergic and non-beta-adrenergic neurons, which release a yet unidentified vasodilator neurotransmitter mediating the neurovascular effect.

Animals↗
PubMed1986

Conservative surgery of renal cell carcinoma.

From 1967 to 1985 conservative surgery (enucleation, n = 49; partial resection, n = 7) was performed for renal tumors in 57 patients (age 31-77, mean 54.8 years). Imperative indications for conservative surgery (n = 29) were chronic renal failure, benign pathology of contralateral kidney, functional or anatomical solitary kidney, and bilateral tumors. Elective conservative surgery (n = 28) was done for small, peripherally located lesions, in cases of uncertain malignancy and in one tumor detected by chance during stone surgery. Tumors removed for imperative indications were 2-11 cm (mean 5.8 cm) in size. In the elective group, tumor size ranged from 1 to 7 cm (mean 3.3 cm). Follow-up was 6-103 months (mean 35.8 months). In the group with imperative indications, there was 1 postoperative mortality; 18 of 29 patients are alive without evidence of disease, 2 with metastases, and 2 were reoperated conservatively for local recurrences; 1 was lost to follow-up, 2 died of metastases, and 3 died due to unrelated reasons. In the elective group all 28 patients are living free of cancer.

Adult↗
PubMed1983

Cultured rabbit vesical smooth muscle cells for lining of dissolvable synthetic prosthesis.

For prosthetic use in genitourinary operations we investigated the feasibility of producing grafts from cultured smooth muscle cells on absorbable synthetic biomaterial. Biopsies of bladder wall muscle without mucosa were obtained from 20 rabbits for culture of smooth muscle cells; cultured cells were examined by light and electron microscopy. Those cells were grown in subculture on a microfiber mesh carrier woven from 35-denier polyglycolic acid fibers. As shown by scanning electron microscopy (SEM), complete coverage of the synthetic fabric was achieved after ten to fourteen days of subculture.

Animals↗
PubMed1983

New surgical procedure for management of Peyronie disease.

Surgical excision of fibrotic plaques and replacement of the defect by grafts may be necessary in advanced Peyronie disease. Synthetic, absorbable mesh for grafting the defect was used in 6 mongrel dogs. An area of tunica albuginea 1.5 by 2.5 cm was removed from the corpus cavernosum, thus exposing the spongy cavernous tissue. A Dexon mesh of the same dimensions, woven in our laboratory from polyglycolic acid fibers of 308 denier thickness, was sutured to the defect by 3-0 Dexon sutures. The mesh caused hemostasis and the animals' postoperative course was uneventful. Posterection cavernosograms showed no curvature of the penis, bulging of the operative area, or obstruction of the corpora cavernosa. Histologic studies at three weeks, and two, four, and six months after surgery showed complete healing and gradual replacement of the Dexon mesh by fibrous connective tissue.

Animals↗
PubMed1983

New treatment for urethral strictures.

A new operative technique using synthetic, absorbable mesh for grafting a urethral defect was applied in 7 mongrel male dogs. The ventral half of the urethral circumference with its surrounding corpus spongiosum was excised for a length of 3 to 4 cm. A Dexon mesh of the same dimensions, woven in our laboratory from polyglycolic acid fibers, was sutured to the defective area. A perineal urethrotomy was established, and no splints were left behind. Dogs were studied between two and six months. Retrograde urethrography showed that the operative area healed without strictures or irregularities. Intravenous urography showed no back pressure effects, and cultured urine was always sterile. Histologic examination two months after surgery showed that the urothelium was completely healed, without inflammatory changes or disruption. Suburothelial tissues were replaced by dense collagenous connective tissue. The excised corpus spongiosum did not regenerate. After six months, the area of dense collagen described was diminished in size so that the operative area could be hardly identified except by the absence of corpus spongiosum.

Animals↗
PubMed1983

Ileal replacement of the bilharzial ureter: is it worthwhile?

Our 14-year experience with the use of isolated ileal segments for replacement of the bilharzial ureter is analyzed retrospectively. Of 52 patients subjected to this procedure followup data were available for 38, in whom 52 ureters were repaired. The results generally were unsatisfactory: the morbidity and mortality rates were high and the percentage of functional improvement was low. The risk was higher for patients with low creatinine clearance. Therefore, we recommend that this operation be avoided when possible. If the operation is unavoidable, tapering of the ileal segment with antireflux ileovesical anastomosis may improve the outcome. Further clinical study must be done.

Adult↗