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Biomedical subjects

K Boukef

Publications and source records attributed to K Boukef.

At least 37 records · Page 2Linked to original sources
PubMed1997

[Screening and confirmation of anti-HCV antibodies in Tunisian blood donors].

Antibodies to Hepatitis C virus (HCV) were tested in 43000 Tunisian blood donors by using enzyme immuno-assay. Our results show that 0.7% (304/43000) were anti-HVC positive. Of these 304.78 were confirmed anti-HCV positive (0.18%) by immuno-blot, and 99 displayed an indeterminate profile. Different immune responses were observed: In donors with positive serologic pattern (78/304), 25.6% response towards whole antigens (C + NS3 + NS4 + NS5) was frequently observed (44/78) 56.4%. Reactivity to 2 antigens was observed in 28.2% (22/78) and with 3 antigens in only 15.4% (12/78), with systematic reactivity to core. In donors with indeterminate serologic pattern (99/304) 32.5%, reactivity to non-structural antigen NS5 was the most frequently observed (54/99) 54.5%, reactivity to non-structural NS3 antigen was noted in 27.3% (27/99) and to core antigen in 18.2% (18/99). No donors with isolated reactivity to NS4 were observed in our series.

Adolescent↗
PubMed1995

[Study of class I HLA polymorphism in the Tunisian population].

The HLA class I gene polymorphism (HLA-A, -B) was investigated in a population of 102 Tunisians. Allele and haplotype frequencies as well as linkage disequilibrium between HLA-A and HLA-B loci were calculated and compared with other populations. The most frequent alleles were A2 (23%), A30 (12.5%), A3 (10.2%), A1 (8.5%), A23 (7.4%) for the HLA-A locus and B21 (14.3%), B44 (11.4%), B35 (9.6%), B5 (8.5%) for the HLA-B locus. The most frequent haplotype was A3 B21 (2.6%) and a positive linkage disequilibrium was found for the following allelic associations: A11 B35 (X2 = 6.8), A28 B35 (X2 = 5.3), and A30 B35 (X2 = 5). In conclusion, a specific distribution of HLA class I components in terms of antigen and haplotype frequencies characterizes the Tunisian population. This specific pattern may reflect the great ethnical diversity of this community. All these informations may be helpful in the future for HLA and disease association studies.

Alleles↗
PubMed1995

HLA class II gene polymorphism in Tunisians.

The polymorphism of HLA class II genes (HLA-DRB, DQB, DPB) was investigated in 101 Tunisians using polymerase chain reaction. (PCR) amplification and reverse dot blot (RDB) hybridization. Allele and haplotype frequencies, as well as DRB1-DQB1 linkage disequilibria, were calculated. A total of 26 DRB1 alleles were detected and the most prevalent variant was DRB1*0301 with an allelic frequency at 21.87%. In the DR1 group, DRB1*0102 was most frequent than DRB1*0101. In the DR4 group, DRB1*0403 was the most common allele and was associated with DQB1*0402. Interestingly this DRB1-DQB1 association has not been observed in other populations. With regard to the DR8 group, DRB1*0804 was the unique variant detected, whereas with the DR13 specificity, the most common variant was DRB1*1303 in Algerians also. Although the DQB1 polymorphism analysis showed an allelic distribution very close to that observed in caucasoids, many DRB1-DQB1 associations which have not been reported in studies of other populations, were described. Finally at the DPB1 locus DPB1*1701 and *1301 allele frequencies distinguish clearly this Tunisian sample from a French caucasoïd panel of 83 subjects. In conclusion, a specific distribution of HLA components in terms of gene and haplotype frequencies characterizises this Tunisian population. This specific pattern may reflect the great ethnic diversity of this community. All these informations may be helpful in the future for HLA and disease association studies.

Gene Frequency↗
PubMed1995

[HCV antibodies in hemodialyzed patients in Tunisia].

The prevalence of seropositivity to Hepatitis C and B virus and HIV infection in Haemodialysis patients was assessed in sera from 235 patients from 6 dialysis units in Tunisia. Anti-HCV antibodies were found in 106 patients (45.10%), the hepatitis B surface antigene was found in 19 patients (8%), and no case of HIV infection was found. Anti-HCV positivity was correlated with duration of dialysis (p < 0.001). There was no correlation between anti-HCV positivity and the number of transfusions.

Adult↗
PubMed1994

[ABO system polymorphism in the Tunisian population].

A survey carried out on 18820 Tunisian blood donors enabled us to evaluate the distribution of ABO blood group in Tunisia. The genic frequencies in ABO system were as follows: A(0,192), B(0,122), O(0,686).

ABO Blood-Group System↗
PubMed1994

Seropositivity to hepatitis C virus in Tunisian haemodialysis patients.

The prevalence of anti-hepatitis C virus (anti-HCV) antibodies and of hepatitis B markers (HBs antigen, anti-hepatitis B core antigen) was assessed in 63 haemodialysis patients from the Tunisian Sahel. As measured by second generation ELISA assays (Ortho and Organon), the frequency of anti-HCV antibodies was 42% (27/63), while 4 patients (6.3%) were HBs Ag positive and 30 (47.6%) anti-HBc positive. Anti-HCV seropositivity was significantly correlated with duration of dialysis (p = 0.007) and number of blood transfusions (> 10 units, p = 0.0004). Among 12 subjects with a history of abnormal ALAT levels, 10 were anti-HCV positive (p = 0.0016) and the results suggest hepatitis C viral infection to be the main cause of liver disease in haemodialysis patients in Tunisia.

Adolescent↗
PubMed1994

Red cell alloantibodies in patients with haemoglobinopathies.

The present study was carried out to determine the evidence of alloimmunization against red blood cells in 364 patients transfused in our center over a period of 4 years (1990-1993). Among these patients, 127 were thalassemic and 182 had sickle cell disease (SCD). In 55 control patients, who received blood matched for the ABO, Rhesus and Kell antigen systems from the outset of transfusion, no immunization was detected. However, in the study group, who initially received blood matched only for ABH and Rh D antigens, the frequency of alloimmunization was 7.76% (24/309). Only one antibody was detected in 15 patients (62.5%) and two or more in 9 patients (37.5%). Alloimmunization concerned the Rhesus system in 58.82% of cases and the Kell system in 26.47%, while the frequency of immunization was significantly lower in patients of less than 5 years as compared to those in the age range 5-10 years (p < 0.001).

Adolescent↗
PubMed1993

[Rhesus system polymorphism in the Tunisian population].

A survey carried out on 4129 Tunisian blood donors permitted to evaluate the distribution of Rhesus blood group in Tunisia. The haplotypes frequency were as follow, R1: 0,367 r: 0,284 R0: 0,2082 R2: 0,1218 R': 0,00188 r'': 0,0001.

Gene Frequency↗
PubMed1992

[Blood donors and anemia].

Biological examinations of 2,630 blood donors showed that 8.6% of them were suffering with anemia. In 4% of the cases we discovered iron deficit and an hemoglobinopathy was found in 0.64% of all the cases.

Adult↗
PubMed1991

[Epidemiologic study of anti-HCV antibodies in Tunisian blood donors].

A study carried out on 2,006 Tunisian blood donors permitted us to evaluate the prevalence of hepatitis C virus antibodies (anti-HCV) which was 1.09%; frequency of indirect markers of NANBH were as follows: ALAT greater than 2 N (1.24%), anti-HBc (30.35%), 55.5% of HCV (+) donors had anti-HBc (+), 12.5% had rises ALAT and only 33.3% both markers.

Blood Donors↗
PubMed1991

First case in Tunisia of PH1 positive chronic myelogenous leukemia in a 3 year old child.

The first case in Tunisia of a 3 year old child with adult type chronic myelogenous leukemia is presented. Diagnosis was based on clinical and biological presentation and detection of Philadelphia (PH1) chromosome. Chronic myelogenous leukemia in children represents 3.8% of all cases of chronic myelogenous leukemia detected in Tunisia between 1970 and 1990. Only one 3.5 year old case was reported without PH1 chromosome.

Age Factors↗
PubMed1982

Unusual heavy chains of human IgG immunoglobulins: rearrangements of the ch domain exons.

Unusual combinations--unexpected sets, excess of lack--of antigenic determinants, or Gm allotypes, on the constant regions of the heavy chains of the human IgG1 and IgG3 immunoglobulins are accounted for in terms of genetic events (exchanges, duplications and deletions) involving the DNA sequences, or exons, coding for the three CH1-, CH2- and CH3 domains of the gamma 1 and gamma 3 chains. Equal and unequal cross-overs at the level of the introns without damage to the CH exons are postulated.

Crossing Over, Genetic↗
PubMed1981

Human transferrin (Tf) and group-specific component (Gc) subtypes in Tunisia.

Simultaneous subtyping of two genetic markers--group-specific component (Gc) and transferrin (Tf)--by electrofocusing enabled us to compute the following gene frequencies for the Tunisian population: Gc1S, 0.525; Gc1F, 0.260; Gc2, 0.215; TfC1, 0.770; TfC2, 0.215; TfD1, 0.015. The frequencies of TfD, TfC2, and Gc1 are higher than those found in Caucasoid populations and can be explained by Negroid contribution. A selective advantage related to the metabolic role of this vitamin D-binding protein does not seem very likely for any particular Gc type or subtype. It is postulated that the differences in the frequencies of the Gc alleles might be related to selective advantage for genes belonging to other genetic systems originally closely linked to either Gc1 or to Gc2 alleles.

Blood Proteins↗
PubMed1981

Frequency of human A gamma 75Thr globin chain in a population from Tunisia.

Cord blood samples, collected at Sousse and Monastir, from Tunisian newborns were focused on a thin layer of agarose in order to detect the carriers of the A gamma 75Thr chain (A gamma chain bearing a replacement Ile-->Thr at position 75). Nineteen individuals (10%) were positive for this variant. The frequency of the A gamma 75Thr gene in the Tunisian population (0.050) is compared with that of various ethnic populations.

Fetal Hemoglobin↗