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Biomedical subjects

S Taha

Publications and source records attributed to S Taha.

At least 19 recordsLinked to original sources
PubMed2006

Effect of alpha-stat vs. pH-stat strategies on cerebral oximetry during moderate hypothermic cardiopulmonary bypass.

BACKGROUND AND OBJECTIVES: This study was undertaken to compare the effect of alpha-stat vs. pH-stat strategies for acid-base management on regional cerebral oxygen saturation (RsO2) in patients undergoing moderate hypothermic haemodilution cardiopulmonary bypass (CPB). METHODS: In 14 adult patients undergoing elective coronary artery bypass grafting, an awake RsO2 baseline value was monitored using a cerebral oximeter (INVOS 5100). Cerebral oximetry was then monitored continuously following anaesthesia and during the whole period of CPB. Mean +/- SD of RsO2, CO2, mean arterial pressure and haematocrit were determined before bypass and during the moderate hypothermic phase of the CPB using the alpha-stat followed by pH-stat strategies of acid-base management. Alpha-stat was then maintained throughout the whole period of CPB. RESULTS: The mean baseline RsO2 in the awake patient breathing room air was 59.6 +/- 5.3%. Following anaesthesia and ventilation with 100% oxygen, RsO2 increased up to 75.9 +/- 6.7%. Going on bypass, RsO2 significantly decreased from a pre-bypass value of 75.9 +/- 6.7% to 62.9 +/- 6.3% during the initial phase of alpha-stat strategy. Shifting to pH-stat strategy resulted in a significant increase of RsO2 from 62.9 +/- 6.3% to 72.1 +/- 6.6%. Resuming the alpha-stat strategy resulted in a significant decrease of RsO2 to 62.9 +/- 7.8% which was similar to the RsO2 value during the initial phase of alpha-stat. CONCLUSION: During moderate hypothermic haemodilutional CPB, the RsO2 was significantly higher during the pH-stat than during the alpha-stat strategy. However, the RsO2 during pH-stat management was significantly higher than the baseline RsO2 value in the awake patient breathing room air, denoting luxury cerebral perfusion. In contrast, the RsO2 during alpha-stat was only slightly higher than the baseline RsO2, suggesting that the alpha-stat strategy avoids luxury perfusion, but can maintain adequate cerebral oxygen supply-demand balance during moderate hypothermic haemodilutional CPB.

Brain↗
PubMed2006

Comparison of RANTES expression in Crohn's disease and ulcerative colitis: an aid in the differential diagnosis?

BACKGROUND: RANTES (regulated on activation, normal T cell expressed and secreted) expression is increased in inflammatory bowel disease (IBD). RANTES is produced at higher levels in granulomatous conditions, so increased RANTES expression can be expected in Crohn's disease compared with ulcerative colitis. AIM: To compare RANTES expression between intestinal biopsy specimens of patients with Crohn's disease and those with ulcerative colitis. MATERIALS AND METHODS: A prospective study of patients presenting with lower gastrointestinal symptoms at the Bahrain Specialist Hospital from July 2004 to April 2005 was carried out. Endoscopic colonic biopsy specimens were taken from every patient and subjected to (a) routine haematoxylin and eosin staining examination by light microscopy, (b) immunohistochemistry for examination of RANTES protein expression by light microscopy and (c) in situ hybridisation for examination of RANTES mRNA expression by light microscopy. RANTES expression was assessed and quantified. RESULTS: 58 patients were enrolled to the study. Of them, 40 had IBD (21 had Crohn's disease and 19 had ulcerative colitis), 15 were controls with normal colonic biopsy results or non-inflammatory lesions and 3 had colonic inflammatory lesions other than IBD. RANTES expression in lymphocytes or histiocytes was significantly higher (p = 0.04) in new patients with ulcerative colitis than in those with Crohn's disease analysed by immunohistochemistry (IHC). CONCLUSION: RANTES expression in lymphocytes or histiocytes is significantly higher in patients with ulcerative colitis than in those with Crohn's disease. Hence, RANTES IHC can be an effective method for distinguishing between biopsy specimens of patients with ulcerative colitis from those of patients with Crohn's disease, where routine histological features are indeterminate. RANTES IHC may prove to be a useful technique for identifying early or equivocal granulomas.

Biomarkers↗
PubMed2004

[The Dijon Physical Activity Score: reproducibility and correlation with exercise testing in healthy elderly subjects].

PURPOSE: To validate a French physical activity score for current use in healthy elderly people. PATIENTS AND METHODS: A brief questionnaire was developed for healthy elderly subjects older than 72 years. Questions asked about self-assessed physical fitness (1), daily activity (2), leisure and sport activity (5) and rest time (1). Correlations were searched between the score and several parameters of physical fitness: maximal exercise stress test (peak VO(2)), six-minute walk test, 200-meter long walk test, timed up an go test. RESULTS: A total of 57 subjects were studied (mean age, 77.6 +/-3.6 years; 28 females and 29 males). The mean time to complete the questionnaire was 3.96 minutes. Reproducibility was 0.606, as determined by Spearman's coefficient. Correlations were found between the physical activity score and peak VO(2) (0.302, P <0.05) and peak power (0.257, P <0.10). CONCLUSIONS: This easily obtained physical activity score provides a new way to assess physical activity in active elderly subjects. The physical score correlated in part with maximal ability but must be validated in several diseases.

Activities of Daily Living↗
PubMed2003

[Cervical medullary metastasis in a patient with Von Hippel-Lindau disease].

Von Hippel-Lindau disease is an autosomal dominant disorder mainly characterized by hemangioblastoma(s) associated with kidney clear-cell carcinoma. Hemangioblastoma represents 2 to 3% of all central nervous system tumors whereas extramedullary metastasis accounts for 30 to 50% of all intravertebral column tumors. The most common sites of metastatic dissemination in order of frequency are the lung, breast, prostate and kidney. We report a case of an unusual cervical intradural extramedullary metastasis of clear-cell kidney carcinoma associated with a cervical spinal cord hemangioblastoma in a 45-year-old patient with Von Hippel-Lindau disease who had developed retinal hemangioblastomas 20 years earlier. A review of the relevant literature is proposed.

Adult↗
PubMed2003

[Tophaceous gout of the cervical spine, causing cord compression. Case report and review of the literature].

We present the case of a 74-year-old patient with long-standing gout who developed C4-C5 tophaceous gout causing cord compression. The patient had undergone 4 years earlier for a disco-osteophytic cord compression (anterior C4-C5 and C5-C6 discectomy). When admitted, the patient presented quadriparesia which had developed during the previous week in association with acute tophaceous gout on the knees, and the metarsophalangeal articulations, in the context of a bronchial infection. The diagnosis of spondylodiscitis was initially retained because of the clinical features of severe infection and the radiological data (C4-C5 cord compression, with anterior epidural lesions in MRI). The intervention allowed decompression and pathological diagnosis of tophaceous gout. Spinal gout is well-known, and very rarely responsible for cord compression: only 15 cases of cervical gout have been described in the literature. Radiological findings are not specific, and treatment is surgical in the event of medullar compression despite medical treatment.

Aged↗
PubMed2000

Apnea-induced hemoglobin desaturation during one-lung vs two-lung ventilation.

PURPOSE: To compare the rate of apnea-induced hemoglobin desaturation during one-lung ventilation (OLV) vs. two-lung ventilation (TLV) in patients undergoing thoracic surgery. METHODS: Six patients undergoing thoracotomy or thoracoscopy were included. Each patient served as his/her own control. The lungs were ventilated with oxygen 100% using TLV, followed after 20-30 min by OLV and the resultant PaO2 was measured. Apnea was then induced following the two techniques of ventilation, and the times for every 1% decrease in hemoglobin saturation from 100% to 95%, as monitored by pulse oximetry, were recorded. The times for every 1% decrease in the saturation were compared in the two groups. RESULTS: The mean PaO2 value following TLV (445+/-99 mm Hg) was higher than the mean PaO2 following OLV (156+/-18 mm Hg). Also, the mean time for subsequent apnea induced hemoglobin desaturation from SpO2 100% to 95% following TLV was twice the time of desaturation following OLV (6.3+/-1.2 min vs. 3.2+/-0.5 min, P<0.05). CONCLUSION: Hemoglobin desaturation occurs more rapidly during apnea following OLV than TLV. The rapid desaturation may be attributed to the decrease of FRC, associated with an increased transpulmonary shunting. The results suggest that two-lung ventilation with oxygen 100% provides a greater safety margin than one-lung ventilation with oxygen 100% whenever ventilation is interrupted.

Adult↗
PubMed2000

A comparative study between classical stirred and ultrasonically-assisted dead-end ultrafiltration.

The aim of this work was to determine mass transfer coefficients in the cases of ultrasonically-assisted and classical stirred dead-end ultrafiltration. A comparative study was then performed, and mass transfer coefficients obtained under ultrasonic conditions are described by an empirical model. This correlation results from an analogy with what is observed using a stirred cell and involves the ultrasonic power as the main parameter. The hydrodynamics are assumed to depend on the intensity of the ultrasound effects illustrated by the agitation arising within the cell. This agitation is due to convective currents as well as physical effects due to cavitation. The concentration polarization phenomenon is therefore affected by this action of ultrasonic waves.

Journal Article↗
PubMed2000

[Dermoid cyst of the lateral ventricle associated with ethmoidal dermal sinus. Report of a case].

We report a case of a ventricular dermoid cyst associated with a dermal sinus connected with the ethmoidal cells in a patient who developed rapid symptoms of raised intracranial pressure. Computed tomography showed a cystic mass in the right lateral ventricle with a hydrolipidic image in the left frontal horn of the ventricle and associated hydrocephalus. Magnetic resonance imaging showed a heterogeneous T1 hyperintense mass with a fistulous tract communicating with the ethmoid cells. A cerebrospinal fluid ventriculo-peritoneal shunt was initially established, which required further revision. A right sided transventricular approach was undertaken in a second stage, allowing resection of a dermoid cyst. Obliteration of the dermal sinus tract was obtained using pericranial duraplasty. Clinical and imaging features are discussed. The need for total resection including the tumor capsule and occlusion of the fistula are emphasized if recurrence and infection are to be prevented.

Adult↗
PubMed2000

[Aneurysm of the postero-inferior cerebellar artery associated with arteriovenous malformation].

A saccular aneurysm of the posterior inferior cerebellar artery lying in the fourth ventricle and an arteriovenous malformation in the cerebellum fed by the same artery are reported. Clipping of the neck of the aneurysm and total removal of the arteriovenous malformation were performed successfully during one stage. Review of the pertinent literature indicates that the aneurysm of the posterior inferior cerebellar artery originates from the peripheral portion of the artery when associated with arteriovenous malformation. The treatment is often surgical with good results in more than 80% of cases. A one-stage operation is the method of choice. Embolization is not without risk and can be attempted when the PICA's course allows easy catheterization.

Aged↗
PubMed2000

Sevoflurane anesthesia in a myasthenic patient undergoing transsternal thymectomy.

Myasthenia gravis (MG) is an autoimmune disease resulting from the production of antibodies against the acetylcholine receptors of the neuromuscular synapse. The thymus gland is involved in the autosensitization process, and there is a consensus that all adults with generalized MG should have a thymectomy. Removal of a much thymic tissue as possible via the transsternal approach in the logic goal of thymectomy in the treatment of MG. Because of the unpredictable response to succinylcholine and the marked sensitivity to nondepolarizing muscle relaxants in the MG patients, some anesthesiologists avoid the use of muscle relaxants in the myasthenic patients, and depend on deep inhalation anesthesia, such as halothane, isoflurane or sevoflurane. In the present report, we used sevoflurane 4%, without supplementation by muscle relaxants, for the induction and maintenance of anesthesia in a MG patient undergoing transsternal thymectomy. The report reviews the anesthetic technique, and describes the electromyographic (EMG) changes following sevoflurane.

Adult↗
PubMed1999

Homocysteine induces DNA synthesis and proliferation of vascular smooth muscle cells by a hydrogen peroxide-independent mechanism.

Elevated plasma levels of homocysteine have been identified as an important and independent risk factor for cerebral, coronary, and peripheral atherosclerosis, although the mechanisms are unclear. Homocysteine has been shown to promote cell proliferation and induction of the gene transcription factor c-fos in vascular smooth muscle cells. Earlier reports have suggested that homocysteine exert its effect via hydrogen peroxide (H2O2) produced during its metabolism. To evaluate the contribution of homocysteine to the pathogenesis of vascular diseases, we examined whether the effect of homocysteine on vascular smooth muscle cell growth is mediated by H2O2. We observed that 1.0 mM homocysteine induces DNA synthesis by 1.5-fold and proliferation of vascular smooth muscle cells two-fold in the presence of peroxide scavenging enzyme, catalase (2,600 U/ml). Our results suggest that homocysteine induces smooth muscle cell growth by an H2O2-independent pathway and that the effects of homocysteine may sum together with the known initiating events produced by oxidative stress and accelerate the progression of atherosclerosis.

Animals↗
PubMed1998

Effect of vitamin E and probucol on dietary cholesterol-induced atherosclerosis in rabbits.

The preventive effect of vitamin E and Probucol against atherosclerosis in rabbits were compared. Atherosclerosis was induced by a 2% cholesterol-containing vitamin E-poor diet (5-10 ppm). Six groups of five rabbits each were studied. Group I (control) was fed on a vitamin E-poor diet. The other groups had the following supplements: group II, 50 mg/kg vitamin E i.m.; group III, 2% cholesterol; group IV, 2% cholesterol plus 50 mg/kg vitamin E i.m., group V, 2% cholesterol plus 1% Probucol; group VI, 2% cholesterol + 1% Probucol plus 50 mg/kg vitamin E i.m. After 4 weeks, aortas were removed and analyzed by light and scanning electron microscopy for atherosclerotic lesions. Samples of the media were analyzed for protein kinase C activity. The aortas of cholesterol-fed rabbits showed typical atherosclerotic lesions, detected by microscopic examination, their media smooth muscle cells exhibited an increase in protein kinase C activity. Vitamin E fully prevented cholesterol-induced atherosclerotic lesions and the induction of protein kinase C activity. Probucol was not effective in preventing either cholesterol-induced atherosclerotic lesions or the induction of protein kinase C activity. These results show that the protective effect of vitamin E against hypercholesterolemic atherosclerosis is not produced by an other antioxidant such as Probucol, and therefore, may not be linked to the antioxidant properties of this vitamin. The effects observed at the level of smooth muscle cells ex vivo suggest an involvement of signal transduction events in the protective effect of vitamin E against atherosclerosis.

Animals↗
PubMed1998

[Trauma-induced arterial aneurysm in childhood. Report of a case and review of the literature].

We report a case of calloso-marginal artery aneurysm in a 3 year old child, revealed 3 weeks after a craniocerebral trauma with frontal embarrure, by a sudden subarachnoidal hemorrhage syndrome with loss of consciousness and coma. The CT scan confirmed the subarachnoid hemorrhage in all the basal cisterns, with an interhemispheric subdural hematoma. The carotid angiography showed a right calloso-marginal aneurysm. The child has been operated (coagulation of the artery and excision of the false aneurysm. We studied the mechanism of pediatric post-traumatic aneurysm, the histological and clinical presentation emphasizing the necessity of a complete neuroradiological exploration when new neurological symptoms develop after head trauma. Neurosurgical and/or endovascular neuroradiological treatment is mandatory.

Accidents, Traffic↗
PubMed1998

[Chronic subdural hematoma in utero. Case report with literature review].

We present a case of chronic subdural hematoma diagnosed in utero by ultrasonography, and MRI at 31 weeks gestation. No cause of usual intracranial hemorrhage was found. There was no trauma. The child was operated after induced vaginal delivery at 37 weeks gestation, with good results and normal neuropsychological development after one year. We discuss the symptomatology and the therapeutic attitude in such cases.

Adult↗