Biomedical subjects
Publications and source records attributed to A Saad.
A massive teratoma in the faciocervical region was found in a fetus at 21 weeks, with laboratory evidence of anemia and thrombocytopenia. Vaginal delivery was achieved by cardiocentesis followed by Laminaria tent insertion, dilation and evacuation.
Arylsulphatase A (ASA, EC 3.1.6.1) is a lysosomal enzyme that catalyses cerebroside sulphate degradation. ASA deficiency is associated with metachromatic leucodystrophy (MLD), a rare autosomal recessive disorder, which is characterised by the storage of cerebroside sulphate. Low ASA activities can be also observed in clinically healthy persons, a condition termed ASA pseudodeficiency. Two mutations responsible for the majority of pseudodeficiency alleles have been defined in the ASA gene. These are both A-->G transitions. One causes an asparagine to serine substitution (N350S). The second changes the first polyadenylation signal downstream of the stop codon (1524 + 95A-->G), which causes a severe deficiency of one ASA mRNA species. The incidence of the pseudodeficiency allele is estimated to be high in the general population and can be found in families carrying MLD associated mutations. We report a reliable stratagem for detecting the two PD associated mutations separately, which we have applied to a healthy population. Two homozygotes for the N350S and 1524 + 95A-->G mutations were detected, which gives a population frequency of 2.6%. The overall frequencies of the ASA-PD mutations were shown to be 17.5% for the N350S change and 13.0% for the 1524 + 95A-->G change, estimating each mutation separately. In addition, the frequency of both PD associated mutations occurring together on the same chromosome was found to be 12.3% in our population. The study has also allowed us to establish a new control ASA activity range, which was based on assay of blood from persons who had been shown at the DNA level not to carry ASA PD associated mutations.
The c-kit receptor and its cognate ligand, KL, play a critical role in melanogenesis, gametogenesis, and hematopoiesis. Studies on the expression of c-kit and KL have been primarily focused on mouse development. We undertook the present study to characterize the pattern of expression of these molecules in normal adult human tissues. Using immunohistochemistry and consecutive tissue sections from the same block, we evaluated a variety of well-preserved normal tissues for c-kit and KL microanatomic distribution. c-kit protein was identified in tissue mast cells, melanocytes, glandular epithelial cells of breast, parotid, dermal sweat, and esophageal glands. Scattered c-kit immunoreactivity was also observed for testicular and ovarian interstitial cells. A striking regional distribution of c-kit was detected in the central nervous system, particularly in the cerebellum, hippocampus, and dorsal horn of the spinal cord. KL protein was identified in cells complementary to staining for the receptor, such as glandular myoepithelium of breast and sweat glands. Intense KL immunoreactivity was observed in smooth muscle cells of the bladder, cervix, uterus, and gastrointestinal tract, as well as in striated and cardiac muscle. Strong KL staining was also detected in prostate fibromuscular stroma cells. In the central nervous system, KL expression was confined to Golgi and Purkinje cells in the cerebellum. These results suggest a role for this receptor and its ligand in the maintenance of a variety of fully differentiated tissues.
BACKGROUND: The purpose of this study was to examine the reliability and validity of the newly proposed axis V (disabilities) of ICD-10. METHOD: Eighty-six acutely ill men and women were prospectively recruited from the Al Ain psychiatric units, UAE. Both versions of ICD-10, the Clinical Descriptions and Diagnostic Guidelines and the Diagnostic Criteria for Research (DCR) were used for coding axis I psychiatric diagnosis and its grade of severity; the WHO Disability Assessment Schedule was used to assess disabilities. RESULTS: Inter-rater reliability of the DAS items ranged from moderate to good, and axis V ratings correctly predicted 84% of the observed classification on axis I. CONCLUSION: Axis V is a valid measure of disabilities, but is limited by its modest reliability.
The reproductive features of wild all-acrocentric and 2n = 22 Robertsonian (Rb) house mice (M. m. domesticus) from Tunisia were studied. The aim was to examine the possibility of a reproductive selective advantage associated with chromosomal change as well as to measure the effect of heterozygosity for a large number of Rb fusions on the fertility of hybrids. Results showed that litter sizes were significantly smaller in Rb than in all-acrocentric mice. This difference, which may represent a favourable demographic strategy related to the habitat segregation observed in the Tunisian mice, needs to be studied further. The F1 hybrids between the two chromosomal races showed a significantly reduced reproductive success and litter size (respectively, 53 per cent and 60 per cent less than either parental race). Analysis of the testicular histology of F1 and backcross males showed in some cases a breakdown of spermatogenesis. The degree of this disturbance was not related to the level of chromosomal heterozygosity suggesting that genetic incompatibilities between the two genomes might be involved. The strong reduction in fertility measured in these hybrids represents a reproductive isolating mechanism effectively reducing gene flow between the all-acrocentric and 22Rb mice populations of Tunisia.
The pharmacokinetics of amikacin were studied in healthy mature female chickens (n = 6). Single doses of amikacin were injected as an i.v. bolus (10 mg/kg) and i.m. (20 mg/kg) into the same birds with a 30-day rest period between treatments. Amikacin was determined by the fluorescence polarization immunoassay method. The i.v. pharmacokinetics could be described by a two-compartment model with a t1/2 alpha of 0.150 +/- 0.064 h and a t1/2 beta of 1.44 +/- 0.34 h. The total body clearance was 0.109 +/- 0.017 1/h/kg and the volume of distribution at steady-state was 0.193 +/- 0.060 l/kg. Following a single i.m. injection, the peak plasma concentration (Cmax) was 50.79 +/- 4.05 micrograms/ml and occurred at 0.50 +/- 0.26 h. The i.m. extent of absorption was 91.2 +/- 17.6%. Simultaneous modeling of i.v. and i.m. results provided estimates of an absorption half-life of 0.480 +/- 0.158 h. The i.m. pharmacokinetics after repeated administration were studied following the tenth dose (20 mg/kg, every 8 h). The Cssmax was 38.58 +/- 6.96 micrograms/ml and occurred at 0.79 +/- 0.37 h, and the biological half-life of amikacin was 1.86 +/- 0.47 h. The multiple dosing yielded peak concentrations of 39 micrograms/ml and trough concentrations of 3.26 micrograms/ml. Based on these data, the recommended amikacin dosage in chickens is 20 mg/kg body weight every 8 h.
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A new case of trisomy 4p is reported. The patient was a boy with dysmorphism, growth failure and developmental retardation. Craniofacial features included microcephaly with a flat forehead, a prominent glabella, hyperteleorism, a broad, concave nasal bridge, a bulb-shaped nose, a wide mouth with a prominent upper lip and a short philtrum, low-set ears, a low hairline, micrognathia, and a short neck. Abdominal muscles were normal. Cryptorchidism with a hypoplastic scrotum and a micropenis were found, as well as forced flexion of the fingers and talipes equinus. The intravenous urogram disclosed ptosis of the right kidney. Developmental retardation was severe with an IQ under 50. RHG banding techniques on peripheral lymphocytes disclosed 4p14 pter duplication. The karyotype was 46,XY inv dup(4-p) (p14----pter). The mother's karyotype was normal. The father had a translocation between the short arm of chromosome 4 and the long arm of chromosome 15; his karyotype was 46,XY, t(4;15) (p14;q26). Thus, the child had trisomy for a segment of the short arm of chromosome 4 (p14----pter) and monosomy for the terminal band of the long arm of chromosome 15 (15q26). The first case of trisomy 4p was reported in 1970 by Wilson et al. Since then, there have been 46 additional reports in the medical literature. Although children with trisomy 4p share a number of features, the phenotypic manifestations of this chromosomal abnormality are variable and nonspecific, making clinical diagnosis difficult.
Vasectomized men with sperm auto-antibodies (S.A.A.) and high frequency of HLA-A20 antigen (Ag) were observed by Law et al. (1979); Hancock et al. (1983) observed the prevalence of HLA-A28 in infertile men with S.A.A. HLA-A, B and DR Ag were determined in a population of 80 Caucasian infertile men with (n = 22) or without (n = 58) agglutinating and/or cytotoxic S.A.A. in serum (S) and/or seminal plasma (SP), and the association between HLA-determinants and infertility with S.A.A. was investigated. The frequence of HLA-A28 Ag was found higher in the group with S.A.A. than without (18.2% vs 0.0%) but not statistically significant (chi 2 = 8.87; pc less than 0.15). The same result was obtained with HLA-B13 Ag (chi 2 = 8.87; pc less than 0.32). Lastly, there was no prevalence of HLA-DR Ag in men with S.A.A. In conclusion, no association was found between HLA-A, B and DR Ag and infertility with S.A.A. Nevertheless, two HLA-Ag were more frequently observed in the group with S.A.A.
Inoculation of metallic tin powder into Lewis rats resulted in marked enlargement of the draining lymph nodes. Plasma cells were the major contributors to the increase in cell mass. Certain immunologic aspects of this plasma cell lymphadenopathy were investigated. Immunoglobulin isotypes were distinguished and quantitated by fluorescence immunocytochemistry and rocket electrophoresis of lymph node extracts. Background plaque-forming cells directed against sheep red blood cells were increased. Specific activity was highest 4 days after inoculation of tin. Lymph nodes and spleen continued to increase in cell number so that total background activity attained a maximum at 14 days after inoculation of tin. Tin was a good adjuvant for plaque-forming cells in lymph nodes and for serum agglutinins (primary and secondary responses) when the rats were immunized with sheep red blood cells, even when the antigen was injected at a remote site. The plasma cell response to tin may be due to local polyclonal activation.
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Explore the source record for details and available documents.
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An agglutinin test for the determination of antibody responses to Vibrio cholerae, requiring only 0.025 ml of serum, has been developed. This microtechnique permits the determination of agglutinin titres using fingertip blood, with results comparable with those obtained using venous blood taken at the same time.Among 364 serum pairs in bacteriologically confirmed cases of cholera from an endemic area of East Pakistan, the second serum sample being obtained 6 days or more after the onset of symptoms, a fourfold rise in agglutinin titre occurred in 77.6% of children under 5 years and in 93.2% of persons 5 years of age or older. This titre rise was quite often demonstrated only against a bacterial suspension of the same serotype as the infecting organism. Among 198 serum pairs in bacteriologically negative cases, a fourfold titre rise against the Inaba suspension only was found in 1 case; 5 other persons with fourfold titre rises proved to be household contacts of cholera patients and are taken to represent bacteriological failures or responses to cholera vaccine rather than false positive serological responses.
A microtechnique is described for the determination of vibriocidal antibodies to Vibrio cholerae, using 0.025 ml of fingertip blood or venous serum per test. This test could be used in epidemiological surveys, or as a routine test on patients admitted to hospital.Fourfold or greater rises in vibriocidal titre were noted for 96.5% of 370 bacteriologically confirmed cholera patients in an endemic area of East Pakistan (91.5% for the 94 children under 5 years in the study group). It is necessary to test sera against both Ogawa and Inaba serotypes of V. cholerae, as a significant titre rise was found against the homologous serotype only in 11% of the cases, and against the heterologous serotype only in 2%.Six serologically positive but bacteriologically negative persons were found to be household contacts of confirmed cholera patients (and 3 of the contacts had been vaccinated against cholera within 1 week before testing); 3 other cases (1.6%) were considered to be false positives.The vibriocidal test using fingertip blood was compared with daily rectal swabbing for the detection of cholera carriers among 153 household contacts of cholera patients, who had not received cholera vaccine within 2 weeks before testing; 16% gave a positive vibriocidal titre, while V. cholerae was isolated from 13% only.