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M Said

Publications and source records attributed to M Said.

At least 19 recordsLinked to original sources
PubMed2006

The importance of the Thr17 residue of phospholamban as a phosphorylation site under physiological and pathological conditions.

The sarcoplasmic reticulum (SR) Ca2+-ATPase (SERCA2a) is under the control of an SR protein named phospholamban (PLN). Dephosphorylated PLN inhibits SERCA2a, whereas phosphorylation of PLN at either the Ser16 site by PKA or the Thr17 site by CaMKII reverses this inhibition, thus increasing SERCA2a activity and the rate of Ca2+ uptake by the SR. This leads to an increase in the velocity of relaxation, SR Ca2+ load and myocardial contractility. In the intact heart, beta-adrenoceptor stimulation results in phosphorylation of PLN at both Ser16 and Thr17 residues. Phosphorylation of the Thr17 residue requires both stimulation of the CaMKII signaling pathways and inhibition of PP1, the major phosphatase that dephosphorylates PLN. These two prerequisites appear to be fulfilled by beta-adrenoceptor stimulation, which as a result of PKA activation, triggers the activation of CaMKII by increasing intracellular Ca2+, and inhibits PP1. Several pathological situations such as ischemia-reperfusion injury or hypercapnic acidosis provide the required conditions for the phosphorylation of the Thr17 residue of PLN, independently of the increase in PKA activity, i.e., increased intracellular Ca2+ and acidosis-induced phosphatase inhibition. Our results indicated that PLN was phosphorylated at Thr17 at the onset of reflow and immediately after hypercapnia was established, and that this phosphorylation contributes to the mechanical recovery after both the ischemic and acidic insults. Studies on transgenic mice with Thr17 mutated to Ala (PLN-T17A) are consistent with these results. Thus, phosphorylation of the Thr17 residue of PLN probably participates in a protective mechanism that favors Ca2+ handling and limits intracellular Ca2+ overload in pathological situations.

Acidosis↗
PubMed2006

A new rapid technique for screening the potential of implanted microorganisms to tolerate and grow on petroleum oily sludges.

Standard experimental protocols for biodegrading petroleum hydrocarbons employ microbiological and/or analytical analysis, and require advanced machines and specialized professionals to carry them out. Furthermore, the obtained results involve a high margin of error. In this paper, a new experimental technique was developed to facilitate the study of microbial capability to degrade petroleum oily sludges. The technique is based on growing microorganisms on 0.22 microm filter membranes laid over oily sludge placed in metallic cups. The microbial growth was assessed using the plate counts technique. Sludge degradation was assessed using Fourier Transform Infrared Spectrometry (FTIR), and compared to the decrease in total petroleum hydrocarbons (TPH) using solvent extraction. The protocol was tested using three types of inocula: fungal inoculum containing Paecilomyces variotii; bacterial inoculum containing Bacillus cereus; and fungal-bacterial inoculum containing both strains. Both, fungal and bacterial, strains were isolated from the oily sludge used in the present study, and were tentatively identified as oil degraders. The results of the newly developed technique helped to assess the potential of these cultures to tolerate and grow on the oily sludge.

Bacillus cereus↗
PubMed2005

[Eosinophilic granuloma revealed by torticollis: a case report].

UNLABELLED: Langerhans cell histiocytose is a rare condition in childhood. It presents in different ways ranging from a single bony disease to a multisystemic disease involving vital organs. CASE REPORT: We report a case of single bone involvement revealed by torticollis in an eight-year-old boy. The diagnosis was evocated on radiological findings and confirmed by histologic aspects. After a period of 2,5 years, this child is in total spontaneous remission. CONCLUSION: Torticollis must be explored and watched. Eosinophilic granuloma can be a rare aetiology in children. The outcome is often favorable.

Child↗
PubMed2005

Donor outcomes in right lobe adult living donor liver transplantation: single-center experience in Egypt.

INTRODUCTION AND OBJECTIVES: Living donor liver transplantation (LDLT) is an alternative source of organs for patients with end-stage liver disease (ESLD) in absence of deceased donor LT. In LDLT the greatest concern is donor safety. Our objective was to evaluate the outcome of donors after right lobe liver donation in a single LT center in Egypt. PATIENTS AND METHODS: Fifty LDL resections were performed from 2001 to 2004. The mean donor age was 29.2 +/- 6.4 years. Residual liver volume was 41.1 +/- 4.5%. Mean operative time was 560 +/- 62.2 minutes; mean ICU stay, less than 24 hours; mean hospital stay, 15.4 +/- 7.7 days; and mean follow-up period, 6 months. RESULTS: There was no mortality. The overall complication rate was 68% (34 donors). Major complications included intraoperative bleeding in one, biliary leak in two, and pneumonia in three donors. Minor complications included mild pleural effusion in 13 donors, transient ascites in 10, mild depression in 7, intra-abdominal collections in 3, and wound infections in 1 donor. Residual liver volume did not affect the complication rate. None required reoperation. Return to predonation activity occurred within 6 to 8 weeks. No liver impairment occurred during follow-up. CONCLUSION: Right lobe adult LDLT is a safe procedure with regard to donor outcome. Major complications occurred in only 10% of our series.

Adult↗
PubMed2005

[Imaging of pulmonary hydatid cyst in children].

PURPOSE: We present the various imaging features of pediatric pulmonary hydatidosis based upon a series of 232 cases. The importance of chest radiographs and thoraco-abdominal ultrasound is emphasized. PATIENTS AND METHODS: A retrospective study of 232 children with pulmonary hydatidosis is presented. The 232 cases (130 boys and 102 girls, age range: 18 months to 14 years) were studied between January 1982 and December 2001. Chest radiographs were available in all cases, chest ultrasound in 156 cases and abdominal ultrasound in 212 cases. CT was only performed in 40 cases. Surgery was performed for all patients. Diagnosis was confirmed with serology tests and/or pathological study of resected cysts. RESULT: The total number of pulmonary cysts detected on chest radiographs was 344. The right lung was more frequently affected than the left (208 lesions). A simple cyst was the most commonly observed lesion (220 cysts). Complicated forms were noted in 118 cases. 180 cysts were observed at ultrasound. A simple cyst presenting as an anechoic mass was noted in 140 cases. In 38 cases, the lesion was heterogeneous. In two lesions endocystic germinal membranes were detected. CT visualized 50 lesions. Thirty three lesions were complicated with endocystic floating or collapsed membranes. Bronchiectasis was observed in seven cases. CONCLUSION: Chest radiographs and thoraco-abdominal ultrasound are very useful for the diagnosis of pulmonary hydatidosis and evaluation of lesion extension. CT is useful for diagnosis of atypical or complicated lesions and to detect bronchiectasis.

Adolescent↗
PubMed2005

Transmandibular approach to polycentric recurrent pleomorphic adenoma of the parapharyngeal space.

Surgery for tumors of the parapharyngeal space PPS) requires adequate exposure to identify and protect vital structures. Thus transcervical and transcervical-transparotid approaches to the PPS may be enhanced by mandibulotomy for better visualisation. We have chosen this approach with single mandibulotomy just in front of foramen mentale and without lip incision. We present a 39 years old male who was undergone surgery for policentric recurrency of a pleomorphic adenoma of the parapharyngeal space.

Adenoma, Pleomorphic↗
PubMed2004

ASCIA guidelines for prevention of food anaphylactic reactions in schools, preschools and child-care centres.

These guidelines have been developed by the anaphylaxis working party of the Australasian Society of Clinical Immunology and Allergy to provide advice for minimizing the risk of food-induced anaphylaxis in schools, preschools and child-care centres. The guidelines outline four steps for the prevention of food anaphylactic reactions in children at risk and food policy measures specific to school age and preschool age children.

Age Factors↗
PubMed2004

Phosphorylation of phospholamban in ischemia-reperfusion injury: functional role of Thr17 residue.

Phospholamban (PLB) is a sarcoplasmic reticulum (SR) protein that when phosphorylated at Ser16 by PKA and/or at Thr17 by CaMKII increases the affinity of the SR Ca2+ pump for Ca2+. PLB is therefore, a critical regulator of SR function, myocardial relaxation and myocardial contractility. The present study was undertaken to examine the status of PLB phosphorylation after ischemia and reperfusion and to provide evidence about the possible role of the phosphorylation of Thr17 PLB residue on the recovery of contractility and relaxation after a period of ischemia. Experiments were performed in Langendorff perfused hearts from Wistar rats. Hearts were submitted to a protocol of global normothermic ischemia and reperfusion. The results showed that (1) the phosphorylation of Ser16 and Thr17 residues of PLB increased at the end of the ischemia and the onset of reperfusion, respectively. The increase in Thr17 phosphorylation was associated with a recovery of relaxation to preischemic values. This recovery occurred in spite of the fact that contractility was depressed. (2) The reperfusion-induced increase in Thr17 phosphorylation was dependent on Ca2+ entry to the cardiac cell. This Ca2+ influx would mainly occur by the coupled activation of the Na+ / H+ exchanger and the Na+ / Ca2+ exchanger working in the reverse mode, since phosphorylation of Thr17 was decreased by inhibition of these exchangers and not affected by blockade of the L-type Ca2+ channels. (3) Specific inhibition of CaMKII by KN93 significantly decreased Thr17 phosphorylation. This decrease was associated with an impairment of myocardial relaxation. The present study suggests that the phosphorylation of Thr17 of PLB upon reflow, may favor the full recovery of relaxation after ischemia.

Animals↗
PubMed2003

Role of dual-site phospholamban phosphorylation in the stunned heart: insights from phospholamban site-specific mutants.

Phosphorylation of phospholamban (PLB) at Ser16 (protein kinase A site) and at Thr17 [Ca2+/calmodulin kinase II (CaMKII) site] increases sarcoplasmic reticulum Ca2+ uptake and myocardial contractility and relaxation. In perfused rat hearts submitted to ischemia-reperfusion, we previously showed an ischemia-induced Ser16 phosphorylation that was dependent on beta-adrenergic stimulation and an ischemia and reperfusion-induced Thr17 phosphorylation that was dependent on Ca2+ influx. To elucidate the relationship between these two PLB phosphorylation sites and postischemic mechanical recovery, rat hearts were submitted to ischemia-reperfusion in the absence and presence of the CaMKII inhibitor KN-93 (1 microM) or the beta-adrenergic blocker dl-propranolol (1 microM). KN-93 diminished the reperfusion-induced Thr17 phosphorylation and depressed the recovery of contraction and relaxation after ischemia. dl-Propranolol decreased the ischemia-induced Ser16 phosphorylation but failed to modify the contractile recovery. To obtain further insights into the functional role of the two PLB phosphorylation sites in postischemic mechanical recovery, transgenic mice expressing wild-type PLB (PLB-WT) or PLB mutants in which either Thr17 or Ser16 were replaced by Ala (PLB-T17A and PLB-S16A, respectively) into the PLB-null background were used. Both PLB mutants showed a lower contractile recovery than PLB-WT. However, this recovery was significantly impaired all along reperfusion in PLB-T17A, whereas it was depressed only at the beginning of reperfusion in PLB-S16A. Moreover, the recovery of relaxation was delayed in PLB-T17A, whereas it did not change in PLB-S16A, compared with PLB-WT. These findings indicate that, although both PLB phosphorylation sites are involved in the mechanical recovery after ischemia, Thr17 appears to play a major role.

Amino Acid Substitution↗
PubMed2003

Balloon dilatation of anastomotic strictures secondary to surgical repair of oesophageal atresia.

The purpose of this study was to evaluate the efficiency and safety of oesophageal balloon dilatation in strictures secondary to surgical treatment of oesophageal atresia in 25 children. Patients comprised 15 males and 10 females, aged 1-36 months. Median age was 4 months (interquartile range (IQR)=19). The strictures were more than 50% of oesophageal lumen and the delay from surgical treatment to balloon dilatation varied from 1 month to 36 months. Associated gastroesophageal reflux was noted in 15 patients. All procedures were performed under sedation using fluoroscopic guidance. Balloons of increasing diameter, 4-20 mm were used. Water soluble contrast swallow was performed after each dilatation session. A total of 115 balloon dilatation sessions were performed with a range of 1-14 procedures per patient (median 4 dilatations, IQR=4.5). Dilatation relieved the stricture in all patients over a follow-up period varying from 4 months to 33 months. The best results were noted in children under 6 months, who needed two or few dilatation sessions, with relative risk (RR) of 0.52 and 95% confidence interval of 0.29-0.92. The presence of associated gastroesophageal reflux indicated a high risk (RR of 12, p<0.001) for undergoing more than two balloon dilatation sessions. The only serious complications observed were two cases of oesophageal perforation, which were treated conservatively. Fluoroscopically guided balloon dilatation is a safe and effective treatment in the management of strictures secondary to surgical repair of oesophageal atresia, especially when started early (within 6 months of surgery) and not associated with gastroesophageal reflux.

Catheterization↗
PubMed2003

Commonsense design of patella implant: four years of clinical experience with 124 patients.

BACKGROUND: Patella resurfacing in Total knee Arthroplasty still is an issue of controversy, that results from the statistically poor performance of patella implants. Since the basic fault of conventional designs, in our opinion, is the inadequate thickness of the polyethylene, an innovative patella was designed and rules of technique were set to optimize the surgical procedure. METHODS: Since July 1998 we have employed the new patella in 124 consecutive patients undergoing total knee arthroplasty. They had the patella routinely resurfaced with an implant of a special design of a concave undersurface and a convex (dome) articulating surface. The thickness of the entire implant was uniform at all areas of contact. The bony patella was prepared with a concave reamer and shaped into a dome with a shallow central hole. Fixation with cement gave an optimally stable implant to shear forces and resistance to wear. RESULTS: All patients were studied prospectively and followed up to five years. Results were related specifically to performance of the patella as a part of the entire joint. Two patients died from unrelated causes. Four patients had delayed wound healing. One sustained a transverse fracture of the patella already healed with minimal displacement when she came to our attention. One sustained avulsion of the patella tendon from the tuberosity, which underwent surgical reattachment. Rest pain score (10-0) improved from 5.2 to 0.5. Activity pain score (10-0) improved from 9.0 to 1.4. Walking score (0-10) improved from 3.2 to 8.2. Stairs negotiation (0-10) improved from 2.8 to 8.0 and ADL Function (0-10) improved from 4.3 to 8.2. CONCLUSION: The special technique of resurfacing of the patella was developed during a short learning period. The new design of the patella implant, eight mm thick at any point of contact gave excellent and good results in 91%. There were no intra operative complications. During five years of follow up two complication were encountered and treated successfully: a minimally displaced transverse fracture and an avulsion of the patella tendon from the tuberosity. None of the patellae components required replacement. In our opinion the new design of bio-mechanically reliable patella implant will regain confidence of surgeons who presently refrain from patella resurfacing.

Arthroplasty, Replacement, Knee↗
PubMed2002

[Feminine pseudo-hermaphroditism and ovarian polycystic syndrome: the role of hydrocortisone].

We report the case of a patient who was initially assigned as a male, and in whom the diagnosis of CAH was delayed (17 years of age). He was shown to have female pseudohermaphrodites. Before treatment, plasma testosterone level was: 15 ng/mL (N: 0.1-0.7), 17 OH progesterone (17 OHP): 45 ng/mL (N: 0.1-1.1) and FSH, LH values were below the normal range. While taking hydrocortisone, a rapid onset of new clinical, biological and radiological findings were observed after three months: rapid menarche and thelarche occurred, plasma testosterone and 17 OHP levels decreased, respectively 1 and 3.7 ng/mL, plasma FSH and LH were respectively 4.1 mUI/mL (N: 1.5-7) and 14.3 m UI/mL (N: 1.1-11.7). Polycystic ovaries were shown at sonography. Authors try to discuss the mechanism of the new events observed and specially those related to the polycystic ovarian disease. In a female with untreated CAH at adult age, menarche can rapidly occur once appropriate treatment was started.

17-alpha-Hydroxyprogesterone↗
PubMed2001

Long-term changes in Serengeti-Mara wildebeest and land cover: pastoralism, population, or policies?

Declines in habitat and wildlife in semiarid African savannas are widely reported and commonly attributed to agropastoral population growth, livestock impacts, and subsistence cultivation. However, extreme annual and shorter-term variability of rainfall, primary production, vegetation, and populations of grazers make directional trends and causal chains hard to establish in these ecosystems. Here two decades of changes in land cover and wildebeest in the Serengeti-Mara region of East Africa are analyzed in terms of potential drivers (rainfall, human and livestock population growth, socio-economic trends, land tenure, agricultural policies, and markets). The natural experiment research design controls for confounding variables, and our conceptual model and statistical approach integrate natural and social sciences data. The Kenyan part of the ecosystem shows rapid land-cover change and drastic decline for a wide range of wildlife species, but these changes are absent on the Tanzanian side. Temporal climate trends, human population density and growth rates, uptake of small-holder agriculture, and livestock population trends do not differ between the Kenyan and Tanzanian parts of the ecosystem and cannot account for observed changes. Differences in private versus state/communal land tenure, agricultural policy, and market conditions suggest, and spatial correlations confirm, that the major changes in land cover and dominant grazer species numbers are driven primarily by private landowners responding to market opportunities for mechanized agriculture, less by agropastoral population growth, cattle numbers, or small-holder land use.

Animals↗
PubMed2001

[Pneumatic dilatation of caustic esophageal stenosis in children. Report of five cases].

The ingestion of caustic substances is a frequent accident in the child. The treatment of caustic strictures of the esophagus, which constitute the most frightening complication, varies from conservative treatment to esophageal replacement. We report the preliminary results of a prospective work established since July 1998 and aimed at evaluating the role of pneumatic dilatation in the treatment of these injuries. STUDIED POPULATION: The series included five boys with an average age of six years. Two children were neurologically handicapped. RESULTS: The caustic product was soda (three cases), a dishwasher solution (one case) and bleach (one case). Dysphagia was constant and concerned the semi-fluids in four cases. The stricture was extended over an average length of 4 cm. The total number of dilatations was 36, with an average of seven sessions/patient. No complication was noted. The result was good in four cases. The only failure was noted in a child who presented a gastroesophageal reflux secondary to the scarring phenomena. CONCLUSION: Pneumatic dilatation constitute a therapeutic mean whose results are attested. The best treatment remains, however, preventive: it is the setting out of reach of the child the dangerous products.

Burns, Chemical↗