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Biomedical subjects

A Saad

Publications and source records attributed to A Saad.

At least 19 recordsLinked to original sources
PubMed2002

A study comparing various noninvasive methods of detecting bladder cancer in urine.

OBJECTIVES: To compare the nuclear matrix protein (NMP)-22 assay, bladder tumour specific antigen (BTAstat) test, telomerase activity (using the telomeric repeat amplification protocol assay, TRAP) and a haemoglobin dipstick test for their ability to replace voided urine cytology (VUC) for detecting bladder cancer. PATIENTS AND METHODS: The study included 120 urological patients prospectively recruited and assessed before surgery. A single freshly voided urine sample (approximate 100 mL) was collected from each patient and aliquoted for each test. All assays were conducted according to the manufactures' guidelines; 79 patients were tested for telomerase activity. The results were then compared with VUC and the diagnosis confirmed by cystoscopy and histology. RESULTS: Fifty-two patients had histologically confirmed transitional cell carcinoma. The overall sensitivity for BTAstat, NMP22, telomerase, VUC and dipstick testing was 63%, 81%, 84%, 48% and 50%, respectively. Combining the results for telomerase and NMP22 gave a sensitivity of 100%. For G1 tumours the respective sensitivities were 23%, 62%, 56%, 23% and 15%, for G2 tumours, 68%, 86%, 92%, 50% and 41% and for G3 tumours 88%, 88%, 100%, 71% and 82%. For pTa tumours the respective detection rates were 48%, 70%, 84%, 39% and 30%, for pT1 tumours 80%, 90%, 90%, 50% and 50%, for pT2/pTis tumours, 100/100%, 100/100%, 100/100%, 88/100% and 88/83%. The overall specificity for the respective tests was 82%, 87%, 93%, 87% and 54%; combining the results of NMP22 and telomerase activity increased the specificity to 96%. CONCLUSIONS: There was significantly better detection than VUC when using the NMP22 and TRAP assay, especially for well-differentiated (P < 0.001 and 0.0027, respectively) and superficial tumours (P < 0.001 and 0.034, respectively). Combining the results of NMP22 and telomerase activity yielded values comparable with cystoscopy.

Adult↗
PubMed2001

Fourier amplitude decay of electron cryomicroscopic images of single particles and effects on structure determination.

Several factors, including spatial and temporal coherence of the electron microscope, specimen movement, recording medium, and scanner optics, contribute to the decay of the measured Fourier amplitude in electron image intensities. We approximate the combination of these factors as a single Gaussian envelope function, the width of which is described by a single experimental B-factor. We present an improved method for estimating this B-factor from individual micrographs by combining the use of X-ray solution scattering and numerical fitting to the average power spectrum of particle images. A statistical estimation from over 200 micrographs of herpes simplex virus type-1 capsids was used to estimate the spread in the experimental B-factor of the data set. The B-factor is experimentally shown to be dependent on the objective lens defocus setting of the microscope. The average B-factor, the X-ray scattering intensity of the specimen, and the number of particles required to determine the structure at a lower resolution can be used to estimate the minimum fold increase in the number of particles that would be required to extend a single particle reconstruction to a specified higher resolution. We conclude that microscope and imaging improvements to reduce the experimental B-factor will be critical for obtaining an atomic resolution structure.

Capsid↗
PubMed2001

Gadolinium-enhanced MR angiography of the breast: is breast cancer associated with ipsilateral higher vascularity?

The aim of this study was to assess a possible association between breast malignancy and ipsilateral higher vascularity on gadolinium-enhanced MR angiography. One hundred six patients were examined by dynamic gadolinium-enhanced 3D MR imaging. Magnetic resonance angiographic views were generated by image subtraction and maximum intensity projection. The study included 85 patients with unilateral malignant breast neoplasms and 21 with unilateral benign lesions. Three blinded readers independently reviewed the MR angiograms after masking the lesions and the corresponding contralateral sites. The readers were asked to determine whether vascularity was higher on the right side, higher on the left side, or equal on both sides. The results were analyzed by the Kappa statistic and Pearson's chi-square test. The blood vessels of the breasts were clearly seen in all cases. There was good agreement among the observers (kappa > 0.54) in assessing vascularity on both sides. Breasts harboring malignant neoplasms were found to have a higher vascularity than the contralateral breasts (p < 0.005). This sign of malignancy had a sensitivity of 76.5%, a specificity of 57%, and an accuracy of 72.6%. Blood vessels of the breast can be depicted by MR angiography. Unilateral malignant neoplasms are associated with a higher ipsilateral vascularity. In conjunction with other indications of malignancy on gadolinium-enhanced MR images, a higher ipsilateral vascularity may serve as an additional sign of malignancy.

Adult↗
PubMed2001

Assessment of arsenic level in the hair of the nonoccupational Egyptian population: pilot study.

Arsenic level of hair samples of apparently healthy Egyptian was measured by means of hydride atomic absorption spectrophotometery. It ranged between 0.04 and 1.04 mg As/kg hair, about 55% of the analysed hair samples were within the range of allowable values (0.08-0.25 mg As/kg hair), but 45% were not. There were no considerable sex-related differences (0.303 and 0.292 mg As/kg hair for males and females, respectively). Different educational levels did not influence it either, when the effect of the age had been excluded. Children and adolescents proved to be more susceptible to arsenic as their mean levels (0.353 microg/g), and were significantly higher than those in the adults (0.233 microg/g). Smoking and some dietary habits had an important role in the elevation of arsenic levels among the nonoccupational Egyptian population: 60% of smokers and 66.7% of indoor passive smokers had arsenic levels >0.25 mg As/kg hair. Arsenic levels were also dependent on the kind of smoking, as hair arsenic of the subject smoking molasses tobacco was found to be significantly higher than that of cigarette smokers (0.459 and 0.209 mg As/kg hair, respectively). The frequency of meat and fish consumption per week was also found to be positively, significantly correlated with arsenic levels. On the other hand, the frequency of consumption of fruits, fresh and cooked vegetables, milk and milk products per week beneficially influenced the arsenic level of the hair samples examined. Arsenic content of the consumed water in Egypt was 0.001 mg/l, which is below the maximum drinking water level allowed by World Health Organisation (WHO). Therefore, the arsenic content of domestic tap water hardly contributed to the arsenic exposure of the Egyptian population in the regions of the study. It is likely that exposure routes by smoking, fish and animal protein consumption are the principal cause of arsenic accumulation in the general Egyptian population.

Adolescent↗
PubMed2001

The T-SCAN technology: electrical impedance as a diagnostic tool for breast cancer detection.

In this paper we present the T-SCAN technology and its use as a diagnostic tool for breast cancer detection. We show, using theoretical models with simplified geometries, that displaying planar two-dimensional maps of the currents detected at the breast's surface relate to the electric field distribution within the breast. This distribution is a manifestation of the bulk spatial inhomogeneities in the complex dielectric constant that represent the various tissue types. These differences may be used to discriminate between various pathological states. We furthermore illustrate a useful classifier, based on admittance data measured up to 2 kHz, and we argue that low frequency impedance measurements can be used successfully in breast cancer diagnosis.

Breast Neoplasms↗
PubMed2001

The early detection and diagnosis of bladder cancer: a critical review of the options.

Bladder cancer has a high worldwide incidence matched by a tendency to recur, necessitating close and regular follow-up. Current methods of investigation of bladder cancer involve cystoscopy, ultrasound scanning and contrast urography, with additional information provided by cytology. These methods, although having a high detection rate, are expensive, time-consuming, invasive and uncomfortable. There is, therefore, a need for an inexpensive, noninvasive, quick and simple investigation with a high sensitivity and specificity for the detection of bladder cancer. There are an increasing number of molecular assays available for the detection of bladder cancer. From bladder tumour antigens to nuclear matrix proteins to adhesion molecules, cytoskeletal proteins and growth factors, urology has looked at them all to support the early detection and diagnosis of bladder cancer. This review critically discusses both the commercial as well as the research-based diagnostic assays available (their mode of action, overall accuracy - both by stage and grade, and their uses and limitations from both a clinical as well as a practical point of view). Aiming to give an insight into the options currently available for noninvasive bladder cancer diagnosis, it also provides prospective comment on what new methods/technologies may be useful in the medium term.

Biomarkers, Tumor↗
PubMed2001

[Acute lymphoblastic leukemia with Philadelphia chromosome: eight case reports].

Philadelphia chromosome-positive (Ph+) acute lymphoblastic leukemia (ALL) is an aggressive form of acute leukemia that children ALL. Between 1991 and 1998, eight cases Ph+ ALL (7 males and one female) were diagnosed in our institution by successful cytogenetic studies. Median age was 37 years (range, 1-60 years). Leukocyte count was more than 50 x 109/l in 5 cases. According to the French-American-British (FAB) criteria, six patients were classified L1 and two L2. The Ph+ as sole anomaly was seen in 2 patients (25%), while additional chromosome changes were observed in 6 cases. Complete remission was achieved in 5 cases (62%) and relapse was observed in all cases? The 2-year survival rae was 25% confirming the worse prognosis of this leukemia when treated with standard chemotherapy.

Adolescent↗
PubMed2001

[Insulin resistance index: measurement and potential in human reproduction].

Insulin resistance (IRI) applies to abnormalities of insulin-stimulated glucose metabolism. Biochemical events related to this phenomenon are difficult to search in the absence of overt diabetes mellitus. A simple method to quantify insulin resistance was assessed through the measurement of glucose and insulin (fasting glucose [mmol/L] x fasting insulin [mU/L]/22.5) in patients (n = 50) attending our clinic of human reproduction, including controls (n = 10) and diabetics either unstable or under control (n = 5). Cases with obesity, polycystic ovarian disease, diabetes mellitus, infertility and hypoglycemia showed higher (p = 0.01-0.05) IRI changes, inversely correlated with a decreasing fasting glucose observed in diabetics under treatment with various degrees of control. We conclude that the IRI method used in this work is a reliable estimate of insulin resistance with potential applications for the study of reproductive biology.

Blood Glucose↗
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↗
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↗