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Biomedical subjects

I Ibrahim

Publications and source records attributed to I Ibrahim.

18 recordsLinked to original sources
PubMed1999

Cochlear implants: response to therapeutic irradiation.

PURPOSE: To determine the response of cochlear implants ("bionic ears") to therapeutic irradiation. METHODS AND MATERIALS: A patient with a cochlear implant was referred for palliative cranial irradiation. As there were no published or manufacturer's data available regarding the response to radiation, implants were tested for functional changes following irradiation. Cochlear implants were supplied by Cochlear Ltd. Two units each of models CI22M, CI22M (with the second generation integrated circuit) and CI24M were irradiated with 4 MV X-rays, and an unirradiated unit of each model was used as a control. The implants were irradiated initially with 25 daily fractions to 50 Gy. To determine the response at higher doses, 10 Gy fractions were delivered to the same implants to 100 Gy, followed by a final fraction of 50 Gy (total dose 150 Gy). The implants were tested after each 10 Gy, up to 1100 Gy, and at 150 Gy. Several indicators of functionality were assessed, including RF (radio frequency) link range, and stimulator output current. The radiation shielding effect of the implants was also assessed. RESULTS: Within the dose range < or = 50 Gy, the stimulator output current of the CI22M units was the only parameter to change. At higher doses (to 150 Gy), changes in current output continued, and gradual loss of RF link range occurred in the CI22M units. The CI24M units showed changes in output current to 100 Gy, and large changes at 150 Gy. Dose attenuation by the implants was measured at 6% for ipsilateral single field 4 MV X-rays. CONCLUSION: Our results suggest that patients with these cochlear implants can receive cranial irradiation with a low risk of implant failure. Changes in stimulator output current can be compensated simply by reprogramming the speech map after the course of radiation treatment.

Adenocarcinoma↗
PubMed1998

Variations in the site and size of third ventriculocisternostomy.

Seventy-eight cases of late-onset, non-communicating hydrocephalus were operated upon by third ventriculocisternostomy. The distortion in the anatomy of the dilated third ventricular floor dictated the selection of the target area. The optimal site for the perforation was the translucent, bluish and thinned out part of the floor. This was variable and in 76.9% not in the midline with more than one fenestra done in 35.9%. the size of the ventriculocisternostomy needed not be around 5 mm. Smaller sized openings in a taut floor (60.3%) served the same purpose as bigger ones in a redundant area (39.7%). The success of the procedure could be predicted from the profuse downward flow of cerebrospinal fluid through the perforation, "Whirl Sign". An acceptable assurance of our results was confirmed both clinically and radiologically. The outcome in our series had four grades, namely cured in 78.2%, ameliorated, but still needed diversion, in 16.7%, status quo in 2.5%, and complicated in 2.5%.

Adolescent↗
PubMed1992

Terazosin in the treatment of benign prostatic hyperplasia: a multicentre, placebo-controlled trial.

The dynamic component of bladder outflow obstruction due to benign prostatic hyperplasia (BPH) has been shown to be modified by alpha 1 adrenergic receptors. Terazosin is an alpha 1 receptor-blocking agent with a long half-life permitting once-daily dosing. This drug was administered in a multicentre, randomised, placebo-controlled trial involving patients with symptomatic bladder outflow obstruction. Of 132 patients recruited for the study, 86 were randomised to receive placebo or terazosin, 81 completed the study, and 80 were considered eligible for efficacy analysis. All terazosin treatment groups showed dramatic improvement in obstructive symptoms when compared with the placebo group, but these differences were not statistically significant because of the small numbers of patients in each group. There were improvements in peak urinary flow rates, mean urinary flow rates, and residual urine volumes for the placebo and terazosin groups, but there were no statistically significant differences in the changes between the groups. Terazosin was well tolerated by patients in this study and may provide symptomatic relief in patients with BPH.

Adrenergic alpha-Antagonists↗
PubMed1988

A decade of experience with the glutaraldehyde-tanned human umbilical cord vein graft for revascularization of the lower limb.

Between October 1975 and November 1985, 907 lower limb bypasses were constructed in 715 patients (799 limbs) with glutaraldehyde-stabilized umbilical veins (UV-G) used as the predominant, or sole, graft material. Each reconstruction was classified in one of eight categories depending on the site of the distal anastomosis: above- and below-knee popliteal, anterior and posterior tibial, peroneal, trifurcation, sequential, and crural (tibial or peroneal) bypasses with adjunctive distal arteriovenous fistulas. Primary and secondary cumulative graft patency rates were determined for each category as well as cumulative actual palliation that combines end points of graft failure, amputation, and death. Half-life patencies for popliteal, tibial, and peroneal bypasses were 6.5, 2.3, and 1.7 years, respectively. Perioperative graft thrombosis occurred in 11% of popliteal reconstructions compared with 22% for the crural group. Nonocclusive graft failure caused by infection, aneurysm, or progressive foot gangrene occurred in 87 grafts (8%). The overall infection rate was 4.3%. Anastomotic aneurysms (1.4%) and strictures (2.1%) occurred infrequently as isolated phenomena. The incidence of graft dilatation and aneurysms assumed significant proportion after 5 years (36% aneurysms and 21% dilation); the diagnosis was particularly facilitated by B-mode imaging. Nevertheless, the overall clinical impact of graft degradation remained minimal (6% after 5 years). Twenty-two of 26 graft aneurysms were excised with successful graft replacement achieved in 10. During this 10-year period, our attitudes did change with regard to the indication for UV-Gs in relation to the maturation of infrapopliteal reconstructive surgery, appreciation of the superior results attainable with in situ saphenous vein, recognition of morphologic changes in long-term UV-G implants, and the growing documentation of poor results with polytetrafluorethylene in the crural position. We believe that UV-G is an acceptable alternative to the absent or deficient autologous vein, particularly in patients with limited life expectancy and where expediency may be a critical factor.

Adolescent↗
PubMed1987

Prostaglandins and cellular reaction in uterine flushings. I. Effect of IUD insertion.

Uterine prostaglandin (PG) levels and cellular reaction in response to IUDs were elevated in sixty women. Short-term users (n = 30) were studied in a control cycle and 3 months after IUD insertion, and long-term users (n = 30) were studied at least 2 years after device insertion. A uterine wash was performed in the proliferative and luteal phase of each investigated menstrual cycle; the cellular components were counted and levels of PGE2, PGF2 alpha and their 13,14-dihydro-15-keto metabolites measured. A significant rise in PG levels was observed in the uterine wash shortly after IUD insertion, particularly in the luteal phase. However, there was a significant reduction in PG levels among long-term users, though the cellular reaction showed a continued increment. The absence of correlation between the biochemical and biological responses indicated that neither of them was totally dependent on the other. The decreased PG levels among long-term users does not support the concept of a key role for these substances in the mechanism of action of IUDs. The temporary post-insertion rise in PG levels coincides with the phase of increased bleeding and pain.

Adult↗
PubMed1987

Prostaglandins and cellular reaction in uterine flushings. II. Effect of PG synthesis inhibition in IUD users.

The effect of oral administration of indomethacin (100 mg/day), a potent inhibitor of prostaglandin (PG) biosynthesis, on the PG levels and cellular profile in the uterine flushings in response to the use of an IUD (Lippes Loop size C) was studied in sixty women. Indomethacin reduced the cell counts in both follicular and luteal phases of menstrual cycles before and after IUD insertion. The anti-inflammatory drug decreased PGE2 and PGF2 alpha levels in both phases of the cycle before IUD insertion. After insertion, it inhibited only the formation of PGF2 alpha and its 13,14-dihydro-15-keto metabolite in the luteal phase but not in the follicular phase. In long-term users, however, the drugs reduced the levels of all PGs studied in the luteal phase and only PGF2 alpha and its metabolite in the follicular phase. The implications of these findings in the mechanisms of contraceptive action of IUDs and their side effects are discussed.

Adult↗
PubMed1980

Plasma enzyme activities indicative of liver cell damage in laying fowl given a diet containing 20 per cent of rapeseed meal.

The effects of a diet containing a high proportion of rapeseed meal on the activity of certain plasma enzymes were studied in laying birds. The enzymes studied were alkaline phosphatase (AP), aspartate transaminase (AST), L-gamma-glutamyl-transferase (gamma-GT), isocitrate dehydrogenase (ICDH), leucine arylamidase (LAP), malate dehydrogenase (MDH) and sorbitol dehydrogenase (SDH). No notable differences were observed between the plasma AP, LAP or SDH activities of the birds given the rapeseed meal and the birds receiving a soyabean meal control diet throughout the experiment. However, the plasma AST and gamma-GT activities of the treated birds showed slight elevations while their plasma ICDH and MDH activities showed more marked elevations, which are indicative of liver damage, in response to the diet. Macroscopic observations of the livers of the birds at the end of the experiment were in fairly good accord with the elevation in plasma ICDH and MDH activities noted for the individual birds.

Alkaline Phosphatase↗
PubMed1979

Spontaneous retroperitoneal hemorrhage from a ruptured hypernephroma.

The clinical presentation and roentgenographic findings of renal cell carcinoma have been consistently variable. These patients can appear with flank pain mimicking ureteral colic, flank tumors, or symptomatic metastasis [1]. Systemic cardiac manifestations including cardiomegaly with congestive heart failure due to arteriovenous fistula formation have been reported [2] Roentgenographic findings may show the tumor to be either vascular or avascular. It may present as a spontaneous perforation of the pelvic ureteral system which is demonstrated by intravenous pyelography (3). In this article, we describe a case of hypernephroma in a cyst wall causing severe spontaneous hemorrhage in the retroperitoneal space resulting in a state of hypovolemic shock.

Adenocarcinoma↗
PubMed1976

Bactericidal effect of acrylic acid esters.

The antibacterial effect of p-Cl, p-Br, p-CH3, O-NO2, M-NO2, and p-NO2 substitutions of dimethylaminoethyl-alpha-phenyl-cinnamate on Bacillus subtilis, Sarcina lutea, and Escherichia coli was studied. The compounds were found to be more active against B. subtilis and S. lutea than against E. coli. The NO2 group in the para position was found to have the highest activity compared with the meta and ortho positions.

Bacillus subtilis↗
PubMed1975

Traumatic perforation of the sigmoid colon through schistosomal ulcerations.

A case is presented in which the colon was perforated through a S. mansoni ulcer after blunt abdominal trauma. This is believed to be a unique situation. The colonic complications of schistosomiasis are discussed, and it is expected that they will be seen more frequently in the United States.

Abdominal Injuries↗