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Biomedical subjects

A Farag

Publications and source records attributed to A Farag.

At least 19 recordsLinked to original sources
PubMed2006

How we do it: Switching from mechanical perforation to the CO2 laser; audit results of primary small-fenestra stapedotomy in a district general hospital.

The use of laser for stapedotomy was introduced in our department in the year 2002, and since then has taken over the mechanical technique. A total of 85 patients who had undergone primary stapedotomy with either technique are reported with regards to effectiveness and rate of side effects. Although footplate complications were reduced with the laser, short-term hearing outcomes were similar between the two techniques. In four occasions, the surgeon had to switch back to the mechanical technique unexpectedly. Stapedotomy will continue to be performed with the laser in our department, bearing in mind the occasional need for the older technique.

Audiometry↗
PubMed2003

Role of oral anti-diabetic agents in modifying cardiovascular risk factors.

Patients with type 2 diabetes have an increased risk for cardiovascular disease (CVD) and it accounts for up to 80% of excess deaths in these patients. It has been recognized that type 2 diabetes is associated with an increased prevalence of CVD risk factors, including hypertension, dyslipidemia, microalbuminuria, and altered hemostasis. The benefit of cardiovascular protection can only be partially explained by controlling hyperglycemia. Some of the oral agents used to treat hyperglycemia significantly modify other cardiovascular risk factors. This article will review oral agents used to treat type 2 diabetes and their effects on modifying CVD risk factors.

Albuminuria↗
PubMed1999

Quantitative image analysis of F-actin in endothelial cells.

OBJECTIVE: Filamentous actin (F-actin) plays a central role in maintaining endothelial barrier function. Thrombin and histamine, two inflammatory mediators that increase endothelial permeability, can alter F-actin production and distribution. In this study, we use a newly developed image analysis technique to show that these two inflammatory mediators differentially alter F-actin structure. METHODS: Human umbilical vein endothelial cells were grown to confluence and treated with either histamine (1 microM), thrombin (1 microM) or the agonist's vehicle. The endothelium was stained with BODIPY-phallodin, and digitized images were taken of the treated cells. The digitized images of individual human umbilical vein endothelial cells (HUVEC) were imported into a F-actin image analysis program (FAAP) and converted to layers, each one pixel thick. The program then determined the mean gray level (which corresponded to the amount of F-actin) in each layer starting from the outside of the cell (layer 1) and progressing in one pixel layer increments towards the center of the cell (layer 32). RESULTS: Both inflammatory mediators increased endothelial F-actin production, however, the distribution of the actin was different. Thrombin increased the presence of stress fibers, while also decreasing peripheral banding actin. In contrast, histamine had no effect on peripheral actin compared to control, but did increase the presence of F-actin stress fibers. CONCLUSIONS: These results establish that thrombin and histamine alter endothelial F-actin production in different locations within the cell, which can be quantified using an image analysis program.

Actins↗
PubMed1998

Use of the Hagen-Poiseuille law: a new mathematical approach for the integration and evaluation of anorectal physiological testing in patients with faecal incontinence and pelvic dyschezia and in normal controls.

This work was done in order to study the possibility of using the Hagen-Poiseuille law for flow of fluids through tubes to integrate and quantitate the anorectal physiological parameters in patients suffering from faecal incontinence and functional pelvic outlet obstruction compared to normal controls. The Hagen-Poiseuille law was intended to be used in the explanation of the role played by different sensory and motor functions of the anorectal segment in maintaining continence and normal rectal evacuation. The intrarectal pressures during rest, coughing, attempted defaecation, rectal sensation, and rectal compliance at the point of first rectal sensation were measured using anorectal manometry. Anal canal length and diameter were measured using lateral defaecographic views during rest, squeeze, and attempted defaecation, and the anal sphincteric reflex contraction in response to coughing or Valsalva's manoeuver was measured using plug or needle electromyography. These factors were analyzed using the Hagen-Poiseuille law in order to determine anal canal resistance and flow to air, water, and BaSO4 during rest, coughing, and attempted defaecation in controls, during attempted defaecation in patients with functional pelvic outlet obstruction, and during rest and coughing in patients with faecal incontinence. The Hagen-Poiseuille law could detect anal continence in all controls and could also detect and quantitate functional pelvic dyschezia in all patients. The equation could detect and quantitate faecal incontinence in 8 of 14 patients (57.14%) during rest, in 11 of 14 (78.57%) during coughing, and in all 14 patients after correction for sensory and reflex deficits. Both the Hagen-Poiseuille law and the law of Laplace and their proposed hybrid law were successful in explaining some facts concerning factors affecting normal continence and defaecation. The Hagen-Poiseuille law is a useful new mathematical approach for the integration and quantitation of normal and abnormal continence and defaecation. It can be used to plan for treatment and to determine the outcome of patients suffering from functional anorectal disease.

Adolescent↗
PubMed1997

Obturator internus muscle autotransfer: a new concept for the treatment of anismus. Clinical experience.

In this study 20 patients suffering from chronic constipation due to spastic anal sphincters were operated upon using a new surgical technique. The technique aimed at constructing an active anal dilator mechanism using the obturator internus muscles mobilized from both sides and sutured to the side wall of the anal canal in order to overcome the spastic anal sphincters during defaecation. This series included 3 failures (15%), 16 successful cases (80%), and 1 dissatisfied patient despite normal postoperative investigations (5%). Eleven patients (55%) showed immediate postoperative normalization of their defaecation. Five patients (25%) showed normalization of their defaecation after 10 sessions of electric stimulation of the transposed muscles given 1 month postoperatively for 10 successive days. All the successful cases (16 patients) maintained their good results during the period of follow-up which ranged from 16 to 45 months (average = 30.31 months). For the successful cases, follow-up was from 16 to 42 months (average = 26.72 months). Immediate postoperative complications included 3 cases of wound infection and 2 cases of transient incontinence to gases which responded completely to postoperative Faradic stimulation. No cases of persistent incontinence of any degree were detected among the 20 patients studied. The 3 failures were mainly due to avoidable technical problems. The technique was safe, easy, and physiological, using a strictly perineal approach.

Adult↗
PubMed1996

Detection of irradiated fruits by gas-chromatographic methods.

To detect those fruits which have been subjected to low-dose irradiation (0.5-3 kGy), two methods of chromatography (GC-MS and LC-LC-GC-FID) were used to determine the radiolytic compounds of lipids formed after irradiation, such as alkanes and alkenes. Extraction of volatile hydrocarbon compounds from some parts of irradiated fruits, e.g. the flesh (avocado), seeds (papaya) and kernels (mango and apricot) was carried out. The analysis of hydrocarbons by GC-MS proved the suitability of using C17:1, C16:2, C15:0 and C14:1 as markers for avocados irradiated with a low dose (0.75 kGy). The same indicators appeared following the analysis of papayas and mangoes irradiated with 1.5, and 3.0 kGy. Also, C15:0, C14:1 and C16:3 can be used to identify apricots irradiated with a low dose (0.5 kGy). The detection of alkenes was only improved by a more selective isolation, e.g. of dienes or trienes by LC-LC-GC-FID. Within a few minutes, apricots and avocados irradiated at low doses (0.5 and 0.75 kGy) can be recognized by the indicators C16:2, C17:2 and C16:3, without interfering peaks. In all cases, C16:1, C16:2, C16:3 as well as significant amounts of C17:2 can be used as markers for fruit irradiation.

Alkenes↗
PubMed1996

Effect of L-glutamine supplementation on impaired glucose regulation during intravenous lipid administration.

In contrast to L-glutamine, lipid emulsions are routinely administered to patients receiving nutritional support. The provision of fat during intravenous feeding is essential, but the potentially toxic byproducts of fatty acid oxidation may have adverse metabolic consequences. In the present study, we have examined the effect of L-glutamine, an inhibitor of fatty acid oxidation, on the development of defective blood glucose regulation caused by a 48-hour infusion of 10% intralipid in rats. Male Sprague-Dawley rats (200-290 g) were anesthetized with sodium pentobarbital, the right femoral vein cannulated, and baseline blood samples were taken. Each rat was placed in a metabolic cage with access to water, in the presence or absence of rodent chow. Two hours after waking, the rats were infused with 10% intralipid with either saline (control), 2% L-glutamine, or 2% L-alanine. After 48 hours, all animals were sacrificed and blood samples were again obtained. The mean +/- SEM plasma glucose levels before and after lipid infusion at the rate of 1 mL/hr in control rats fed ad libitum, were 125 +/- 13 and 170 +/- 5 mg/dL (p < 0.01, n = 7). Similarly, plasma free fatty acids (FFA) in these animals rose from 0.74 +/- 0.11 to 1.34 +/- 0.32 mmol/L (p < 0.05). Plasma insulin levels also increased from 337 +/- 44 to 1278 +/- 88 pg/mL (p < 0.01). Reduction of intralipid dose infusion did not prevent insulin resistance characterized by hyperglycemia and hyperinsulinemia. However, addition of L-glutamine to the high-dose lipid infusion with chow feeding prevented changes in plasma glucose, insulin levels, and FFA but not triglyceride levels. Also, glutamine but not alanine supplementation in intralipid infused rats without chow feeding prevented changes in plasma glucose, insulin, and malondialdehyde levels. In conclusion, these data show that glutamine supplementation during intravenous lipid administration in rats prevents the development of impaired glucose regulation associated with hyperlipidemia.

Alanine↗
PubMed1995

Laser welding of everted enterotomies in rats.

OBJECTIVE: To assess the feasibility of welding everted enterotomies with laser. DESIGN: Open study. MATERIAL: 21 Male albino rats (mean weight 152 g). INTERVENTIONS: 28 Full thickness enterotomies (involving 50% to complete circumference of the rat's small intestine) were welded with an Nd-YAG laser non-contact fibre. The bowel ends were everted and held tightly with simple non-toothed forceps during welding. MAIN OUTCOME MEASURE: Success or failure judged by the naked eye. RESULTS: Welding was successful in 14/20 (70%) enterotomies that involved half the circumference of the small bowel but in only 3/8 (38%) when the enterotomy extended further because of inadequate tissue opposition. A new visual end point of welding was noticed. CONCLUSION: Laser welding of everted enterotomies is safe for small enterotomies as judged by the naked eye, but controlled studies are needed before the technique can be tested in humans.

Anastomosis, Surgical↗
PubMed1994

A new option for splenic preservation in normal sized spleen based on preserved histology and phagocytic function of the upper pole using upper short gastric vessels.

Despite the recognized desirability of splenic salvage, forced splenectomy remains the rule in many operative situations, including trauma and pancreatic cancer. An anatomic study was conducted to assess whether the upper short gastric arteries provide sufficient collateral circulation to the spleen that the upper pole could remain viable even when the hilum is resected and the splenic artery and vein no longer intact. The anatomy of the upper short gastric vessels was studied in 59 human spleens and 18 albino rat spleens. Fifty-four human specimens (92%) and 18 (100%) of the rat spleens showed at least 1 upper short gastric artery and 1 vein connecting the fundus of the stomach with the interior of the upper pole of the spleen with no connection to the major hilar vessels. Lower two-thirds splenectomy, which included excision of the hilum of the spleen after ligation of both the splenic artery and vein, was performed on 14 of the 18 rats. The remaining 4 rats served as control animals. The upper pole of the spleen was preserved solely on the upper short gastric vessels that pass directly between the stomach and the interior of the spleen. Structure and macrophage function in the residual splenic tissue was shown to be preserved at 1 hour and 2 weeks postoperatively, based on results of the India ink technique for demonstrating phagocytic function and on results of regular histologic examination. Preservation was attributed to the fact that blood supply for the residual splenic tissue after splenic mass reduction remained adequate through the upper short gastric vessels. Splenic mass reduction is essential to improve perfusion to the residual splenic tissue if excision of the splenic hilum or ligation of the main splenic vessels becomes an operative necessity.

Animals↗
PubMed1994

One-week therapy with oral terbinafine in cases of tinea cruris/corporis.

The use of oral terbinafine in the treatment of superficial dermatophyte infections has been extensively studied, using different treatment regimens. To evaluate the efficacy of short-term therapy with oral terbinafine in cases of tinea cruris/corporis, 22 patients (21 male and one female) with mycologically proven tinea cruris/corporis, were included in the present study. Each patient received one tablet of terbinafine 250 mg daily for 1 week. Patients were followed-up for 6 weeks after completion of treatment. Clinical and mycological assessments were performed at the end of treatment, and at the end of the follow-up period. The mean sum of scores of signs and symptoms in all patients decreased significantly from 12.36 before treatment to 0 at the end of the follow-up period, and mycological investigations were negative in all patients at the end of the follow-up period. Our results show that 1-week therapy with oral terbinafine is highly effective in the treatment of tinea cruris/corporis.

Administration, Oral↗
PubMed1993

Obturator internus muscle autotransplantation: a new concept for the treatment of obstructive constipation. An anatomical, physiological and pathological study.

The feasibility of using obturator internus muscle autotransplantation in order to construct an anal dilator mechanism for the treatment of obstructive constipation was studied anatomically, physiologically and pathologically. Electromyographic studies of 15 obturator internus muscles in 10 healthy adult male volunteers and 3 other muscles in patients with documented spastic anal sphincters demonstrated the ability of the obturator internus muscles to contract during straining at stools. The proposed surgical approach was studied in 9 cadavers (5 stillbirths and 4 adults), followed by formal anatomical dissection of the obturator internus muscle and tendon, pudendal nerve and vessels, inferior rectal nerve and nerve to the obturator internus. Anatomical studies proved the feasibility, ease, rapidity and safety of the technique with or without division of the obturator internus tendon with no incidence of injury to the surrounding nerves, vessels or muscles using a purely perineal approach.

Adult↗
PubMed1992

Thrombosis in spinal cord injury.

Some traditional coagulation assays and several new molecular markers of hemostatic activation were measured in 37 patients with spinal cord injury (SCI). Twenty one of the patients (57%) developed deep vein thrombosis (DVT). The radiofibrinogen uptake test (RFUT) was used to diagnose DVT. Thirty eight percent of quadriplegic and 88% of paraplegic patients developed DVT (p < 0.005). No significant differences were found in platelet counts, mean platelet volumes, fibrinogen levels, von Willebrand factor (Ag) levels, platelet factor 4 and beta thromboglobulin concentrations between the groups with and without DVT. Fibrinopeptide A, thrombin/antithrombin III (TAT) complexes and plasma D-dimer levels were significantly higher in the patients with thrombosis. Most patients with DVT had elevated TAT complex levels up to three days before the RFUT became positive. D-dimer levels were highest after the diagnosis had been made.

Adolescent↗
PubMed1992

Laser hepatorrhaphy in albino rats.

The ability of low-power Nd-YAG laser to weld liver tears was studied in nine albino rats (average body weight 146 g) after induction of 11 liver tears. Laser hepatorrhaphy was successful in ten tears. Haemostasis was achieved with the laser technique in all 11 tears, including the single case of postoperative liver tear dehiscence. Bleeding from the site of a marker stitch was successfully controlled by two additional laser shots in one animal. Histologic studies of successfully welded liver tears were done on the first and third postoperative days.

Animals↗
PubMed1990

Changes in hemostasis activity during delivery and the immediate postpartum period.

Postpartum deep vein thrombosis is believed to be related to increased activation of the hemostasis system at the time of delivery. To date, studies designed to test this hypothesis have had relatively small sample sizes or used the measurement of specific coagulation factors and functional tests reflecting hemostasis activity in vitro. With the use of recent technologic advances we determined the effect of delivery on hemostasis in vivo by measuring 11 hemostatic indices simultaneously in 70 healthy pregnant women. Significant increases were found in fibrinopeptide A (p less than 0.001), beta-thromboglobulin (p less than 0.001), and platelet factor 4 (p less than 0.001), suggesting maximum platelet activation and fibrin formation at the time of delivery. In addition to continued clotting activity at 3 hours post partum, increased D-dimer, fibrin-fibrinogen degradation products, and decreased alpha 2-antiplasmin levels suggest maximum fibrinolysis. These changes reflect a peak in hemostatic activity at delivery and in the immediate postpartum period that may predispose the development of deep vein thrombosis.

Adult↗
PubMed1990

Increased intravascular coagulation associated with pregnancy.

Based on an increased turnover of the hemostatic system, it is believed that pregnancy is associated with "hypercoagulability." However, this hypothesis is based primarily on the measurement of specific coagulation factors or functional tests reflecting hemostatic activity in vitro. Using recent technological advances, we determined the effect of pregnancy on hemostasis in vivo by measuring 11 specific hemostatic indices simultaneously in 28 healthy pregnant women and in 24 nonpregnant female controls. Significant increases were found in fibrinopeptide A (P less than .01), beta thromboglobulin (P less than .001), platelet factor 4 (P less than .02), and fibrin(ogen) degradation products (P less than .001), suggesting increased platelet turnover, clotting, and fibrinolysis. This state of compensated, accelerated intravascular coagulation may be necessary for maintenance of the uterine-placental interface and preparation for the hemostatic challenge of delivery.

Adult↗