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Biomedical subjects

A Saad

Publications and source records attributed to A Saad.

At least 37 records · Page 2Linked to original sources
PubMed2000

The fate and persistence of zineb, maneb, and ethylenethiourea on fresh and processed tomatoes.

Tomatoes grown under greenhouse conditions were sprayed with radiolabelled maneb and zineb to determine the extent of degradation of these fungicides to ethylenethiourea (ETU) and to study the persistence of ETU on the fruits. The total (14C) residues decreased from 0.082 mg/kg and 0.11 mg/kg at day 0 to 0.023 mg/kg and 0.05 mg/kg at day 20, on zineb- and maneb-treated fruits, respectively. This reduction was mainly due to the rapid growth of the fruits. ETU residues on tomato fruits were found to decline with time. A sharp reduction in ETU content was observed during the first 24 h after treatment, followed by a slow decline in the following 5 days. ETU content was reduced by about 80% by day 20 after the fungicide application, and the concentration of EU, the major degradation product of ETU, doubled during the same period. Studies with tomatoes fortified with (14C) ETU (0.006 mg/kg) prior to processing into tomato paste showed that 70% of the radioactivity was lost during washing of the tomatoes in water. Further losses of ETU occurred during boiling of the juice (6%) and during storage of the tomato paste for a period of 3 weeks (3%).

Chromatography, Thin Layer↗
PubMed2000

Thyroid ultrasound compared with World Health Organization 1960 and 1994 palpation criteria for determination of goiter prevalence in regions of mild and severe iodine deficiency.

OBJECTIVES: In 1994, WHO/International Council for the Control of Iodine Deficiency Disorders recommended replacing the WHO 1960 four-grade goiter classification with a simplified two-grade system. The effect of this change in criteria on the estimation of goiter prevalence in field studies is unclear. In areas of mild iodine deficiency disorders (IDD) where goiters are small, ultrasound is preferable to palpation to estimate goiter prevalence. However, in areas of moderate to severe IDD, goiter screening by palpation may be an acceptable alternative to thyroid ultrasound. To address these two issues, we compared WHO 1960 and 1994 criteria with thyroid ultrasound for determination of goiter prevalence in areas of mild and severe IDD in Morocco. DESIGN: A cross-sectional study of 400 six- to 13-year-old children from two mountain villages (Ait M'hamed and Brikcha) in rural Morocco was carried out. METHODS: Urinary iodine concentration (UI), whole blood TSH and serum thyroxine were measured. Thyroid size was graded by inspection and palpation by two examiners using both WHO 1960 and 1994 criteria. Thyroid volume was determined by ultrasound. Variation between examiners and examination methods was assessed. Sensitivity and specificity of the two classification systems compared with ultrasound were calculated. RESULTS: Median UIs in Aït M'hamed and Brikcha were 183 and 24 microg/l respectively. In Ait M'hamed, using 1960 and 1994 criteria, goiter prevalence was 21 and 26% respectively, compared with 13% by ultrasound. In Brikcha, with 1960 and 1994 criteria, goiter prevalence was 64 and 67% respectively, compared with 64% by ultrasound. Agreement between observers was better with the 1994 criteria than with the 1960 criteria in Ait M'hamed (kappa=0.53 and 0.47 respectively), while in Brikcha observer agreement was similar with the two systems (kappa=0.67). Using either the 1994 or 1960 criteria, agreement with ultrasound was only moderate in Ait M'hamed (kappa=0.41-0.44), but good in Brikcha (kappa=0.55-0.64). Overall, compared with ultrasound, sensitivity increased 3-4% using 1994 criteria, while specificity decreased 4-5%. CONCLUSIONS: The WHO 1994 criteria are simpler to use than the 1960 criteria and provide increased sensitivity with only a small reduction in specificity. Agreement between observers is better with the 1994 criteria than with the 1960 criteria, particularly in areas of mild IDD. Like the 1960 criteria, the 1994 criteria overestimate goiter prevalence in areas of mild IDD, compared with ultrasound. However, the 1994 palpation criteria provide an accurate estimate of goiter prevalence in areas of severe IDD, and may be an acceptable and affordable alternative to thyroid ultrasound in these areas.

Adolescent↗
PubMed2000

The epidemiology of schistosomiasis in Egypt: Ismailia governorate.

A multi-stage stratified sample of 12,515 individuals from 1,941 households in 42 villages in the Ismailia governorate of Egypt were surveyed for schistosomal infection. A subset of 2,390 subjects were surveyed for morbidity by physical and ultrasonographic examination. The prevalence of Schistosoma mansoni infection in rural Ismailia was 42.9% and the geometric mean egg count (GMEC) was 93.3 eggs/gram of stool, with considerable variability between communities. Prevalence and intensity peaked in the 20-30-year-old age group and was higher in males than in females. Prevalence and intensity of S. haematobium was very low: 1.8% and 3.5 ova/10 ml of urine GMEC, respectively. Canal water exposure risk factors for S. mansoni infection were males bathing (odds ratio [OR] = 2.2), females washing clothes (OR = 1.9), and children playing or swimming (OR = 2.3). Presence of in-house piped water supply and latrine lowered infection rates (P < 0.001 and P = 0.002, respectively). Histories of S. mansoni infection (OR = 1.6) or treatment (OR = 1.5) and blood in feces (OR = 3.5) were associated with infection. Hepatomegaly (16.0%) was more frequently detected than splenomegaly (3.6%) by physical examination, with both being more frequent in older age groups. Splenomegaly, but not hepatomegaly, was associated with presence of S. mansoni ova in stools (OR = 1.4) and the community burden of infection (P = 0.02). Ultrasonographically detected hepatomegaly, splenomegaly, and periportal fibrosis (PPF) were detected in 43.0%, 17.4%, and 39.7% of the subjects, respectively. The higher grades of PPF were rare. Ultrasonographically detected splenomegaly, not hepatomegaly, was associated with S. mansoni infection, community burden of infection, and PPF. Risk factors for PPF were the same as for S. mansoni infection. There was a marginal association of PPF with infection and none (P = 0.33) with the intensity of infection in individuals or in the community. We conclude that in rural Ismailia, S. haematobium infection is rare but the prevalence and intensity of infection with S. mansoni is high. The risk of infection is associated with environmentally detected factors and behaviors. Hepatosplenic morbidity attributable to S. mansoni infection is low, presumably because of the favorable effect of wide application of praziquantel therapy.

Adolescent↗
PubMed2000

[Acute lymphoblastic leukemia in adults. Apropos of 42 cases].

Between 1989 and 1995, 42 cases with acute lymphoblastic leukemia (18 males and 24 females) were diagnosed in our institution. Median age was 38.5 years (range, 16-88 years). Leukocyte count was more than 30.10(9)/l in 54% of cases. According to the French-American-British (FAB) criteria, 67% were classified L1 and 33% L2. Sixteen patients were treated with 12LA80 protocol, 14 patients with LALA 85 protocol, 6 patients with LALA 87 protocol and 6 patients with EORTC protocol. Complete remission was achieved in 22 cases (52%), 8 cases (20%) failed to respond and 12 (28%) died during induction. Relapse was observed in 10 cases. The 4-year survival rate was 28% confirming the worse prognosis of this leukemia when treated with standard chemotherapy.

Adolescent↗
PubMed2000

[Childhood acute myeloblastic leukemias. Report of 21 cases].

Between 1989 and 1996, 21 cases with acute non lymphoblastic leukemia (11 males and 10 females) were diagnosed in our institution. Median age was 9 years (range, 2-15 years). Leukocyte count was more than 50,109/l in 47% of cases. According to the French-American-British (FAB) criteria, 7 cases were classified M1, 10 cases were classified M2, 1 classified M4Eo and 3 classified M5. All patients were treated with "7 + 3" protocol and complete remission was achieved in 17 cases (80%), 2 cases (10%) failed to respond and 2 (10%) died during induction. Relapse was observed in 15 cases. The 3-year survival rate was 20% and the relapse-free-survival rate was 12% confirming the worse prognosis of this leukemia when treated with standard chemotherapy.

Adolescent↗
PubMed2000

Discriminant analysis of free fatty acids of some Egyptian snails as a step for schistosomiasis control: new trends.

Schistosomiasis is still the most common occupational health problem of rural workers in Egypt. The use of molluscicides, either chemical or biological, and environmental changing are the most successful methods of snail control. The new trend in Schistosoma control programs is to study the ecological factors that attract miracidium Schistosoma specific snails, to emphasizing to find out new environmental safe control methods. Since Schistosoma worms do not make fatty acids de novo, they require host lipids for survival and to complete their life cycle. Discriminate analysis of the estimated free fatty acids was done in this study in Biomphalaria alexandrina, Biomphalaria glabrata, and Bulinus truncatus, viz. Lymnaea truncatula and Physa acuta (Schistosoma intermediate and non-intermediate respectively). With the objective of determination of the biochemical difference that attract the infestation of Schistosoma miracidium to the target snails, as a step of the new control trends. Caprylic acid (C8:0), and Oleic acid (C18:1) are significantly lower in the tissues of Schistosoma intermediate snails compared to the non-intermediate snails. While, Capric acid (C10:0), Margaric acid (C17:0), and Lenoleic acid (C18:2) of the intermediate snails are significantly higher than that of non-intermediate snails. The percent of correct medical classification of snails are more than 80% according to Caprylic acid, Margaric acid, and Lenoleic acid, the other 15 fatty acids are less than 80%. These three free fatty acids could be chemoattractive of Schistosoma miracidium, and could be used as safe environmental control compounds, which needs further research.

Animals↗
PubMed1999

Vaccination against Schistosoma mansoni infection using 74 kDa Schistosoma protein antigen.

An IgG2a anti-Schistosoma mansoni mouse monoclonal antibody was shown to passively protect Swiss mice. The 74 kDa target antigen was isolated from antigenic extracts of S. mansoni adult worms. Swiss and C57 BL/6J mice were immunized with 30, 50, 100 and 200 microg antigen/mouse doses with and without Freund's adjuvant. Sera of immunized mice showed high reactivity against 74 kDa antigen. The highest protection level (76.6% in Swiss mice and 50.1% in C57 BL/6J mice) was obtained using the 50 microg antigen dose with and without Freund's adjuvant. A marked reduction in granuloma number and intensity of collagen and reticular granuloma fibers was observed. The 74 kDa antigen has the ability to protect mice of different strains and to modulate the host immune system.

Adjuvants, Immunologic↗
PubMed1999

Roles of triplex and scaffolding proteins in herpes simplex virus type 1 capsid formation suggested by structures of recombinant particles.

Typical herpes simplex virus (HSV) capsids contain seven proteins that form a T=16 icosahedron of 1,250-A diameter. Infection of cells with recombinant baculoviruses expressing two of these proteins, VP5 (which forms the pentons and hexons in typical HSV capsids) and VP19C (a component of the triplexes that connect adjacent capsomeres), results in the formation of spherical particles of 880-A diameter. Electron cryomicroscopy and computer reconstruction revealed that these particles possess a T=7 icosahedral symmetry, having 12 pentons and 60 hexons. Among the characteristic structural features of the particle are the skewed appearance of the hexons and the presence of intercapsomeric mass densities connecting the middle domain of one hexon subunit to the lower domain of a subunit in the adjacent hexon. We interpret these connecting masses as being formed by VP19C. Comparison of the connecting masses with the triplexes, which occupy equivalent positions in the T=16 capsid, reveals the probable locations of the single VP19C and two VP23 molecules that make up the triplex. Their arrangement suggests that the two triplex proteins have different roles in controlling intercapsomeric interactions and capsid stability. The nature of these particles and of other aberrant forms made in the absence of scaffold demonstrates the conformational adaptability of the capsid proteins and illustrates how VP23 and the scaffolding protein modulate the nature of the VP5-VP19C network to ensure assembly of the functional T=16 capsid.

Capsid↗
PubMed1998

[Fanconi disease: study of 43 cases in southern Tunisia].

BACKGROUND: To report the epidemiologic, clinical, biological features and course of Fanconi's anemia in southern Tunisia. PATIENTS AND METHODS: During a period of 12 years we observed 43 cases. For each patient, careful clinical, biological (hemogram, myelogram, bone marrow biopsy, hemoglobin electrophoresis, karyotype) and radiological (skeleton X-rays, abdominal echography and intravenous urography) examinations were performed. All the patients who were at a pancytopenia stage were given androgens. None had a bone marrow allograft. RESULTS: There were 24 girls and 19 boys. The mean age at diagnosis was 10 years and 9 months. The familial character was present in 53% of the cases. The most frequent initial complaint was anemic syndrome (69%). In ten cases (24%), the diagnosis has been established during a familial investigation. Malformations were present in all cases (abnormal pigmentation: 86%; skeletal maturation retardation: 83%; facial dysmorphy: 76%; statural hypotrophy: 65%; bone abnormalities: 53%; renal malformations: 44%). Anemia was present in 88% of the cases, thrombocytopenia and neutropenia in all cases. Bone marrow was hypoplastic or aplastic in all cases on biopsies. Spontaneous chromosomal breaks were found in 79% of the studied cases. Fetal hemoglobin was increased in 80% of the studied cases with a mean level of 20.5%. Actuarial survival rate at 5 years was 48%, but long survival durations were rare (eight out of 43 patients). DISCUSSION: This disease, rare in the world, seems to be frequent in southern Tunisia. A normal karyotype (with classical techniques), found in five patients, could not discard the diagnosis; for this reason, the use of sensitizing agents should improve the sensitivity of the test. Besides, an increased level of fetal hemoglobin enabled us to suggest the diagnosis in some cases. Androgenotherapy increased the survival duration to more than 5 years in eight patients. However, bone marrow allograft remains the only possibility of cure.

Adolescent↗
PubMed1997

Gluconeogenic activity in response to chronic administration of amphetamine sulphate and drug withdrawal.

1. Chronic amphetamine administration (10 mg/kg) to young rats (Rattus norvegius) (40-90 g) produced an initial hyperglycemia following the initial drug administration. This was followed by progressive hypoglycemia with the continuous drug treatment. 2. The present data also demonstrate increases in levels of serum ACTH and corticosterone that were maintained after drug withdrawal, in the case of corticosterone. 3. The Analysis of the transaminase activity revealed the occurrence of significant increases in serum GOT level. Furthermore, progressive increase in the G-6-Pase activity was recorded, reaching its maximum level by the end of the experiment, which demonstrates that induced amphetamine toxicity is time-dependent.

Adrenocorticotropic Hormone↗
PubMed1996

Advances in the pathologic staging of lung cancer: detection of regional and systemic occult metastases.

Approximately 78% of lung carcinomas would be potentially curable by surgery if they were detected early enough. Thus, the most important factor in predicting outcome and defining therapy is the stage of the disease. This chapter discusses the TNM (primary tumor/nodal involvement/distant metastasis) staging system for lung cancer as well as lymph node and bone marrow micrometastasis status.

Humans↗