TNF-alpha and IL-8: serum levels and gene polymorphisms (-308G>A and -251A>T) are associated with classical biomarkers and medical history in children with sickle cell anemia.

Sickle cell anemia (SCA) is a disorder characterized by a heterogeneous clinical outcome. In the present study, we investigated the associations between Tumor Necrosis Factor-alpha (TNF-alpha) -308G>A and Interleukin 8 (IL-8) -251A>T gene polymorphisms, medical history and classical biomarkers in children with steady-state SCA. In total, 210 SCA patients aged 2-21 years and 200 healthy controls were studied. Gene polymorphisms, betaS-globin haplotypes and a 3.7-kb deletion in alpha2-thalassemia (α2-thal3.7 kb) were investigated by PCR/RFLP analysis, and cytokine levels were determined by ELISA. Splenomegaly (p=.032) was more prevalent among children younger than 5 years of age. The A allele of the TNF-alpha -308G>A gene polymorphism and the presence of α2-thal3.7 kb were associated with an increase risk of splenic sequestration events (p=.001; p=.046), while the T allele of the IL-8 -251A>T gene polymorphism was considered to be a protective factor for splenomegaly events (p=.032). Moreover, the A allele of the TNF-alpha -308G>A gene polymorphism was associated with high TNF-alpha levels (p=.021), and the hemoglobin F and hemoglobin S haplotypes were correlated with serum levels of IL-8. The logistic regression analysis showed significant effects of the TNF-alpha and IL-8 gene polymorphisms, beta(S)-globin gene haplotypes and α2-thal3.7 kb on the occurrence of splenic sequestration events. Our study emphasizes that the identification of new genetic and immunological biomarkers and their associations with classical markers is an important strategy to elucidate the underlying causes of different SCA phenotypes and their effects on patient outcome.

Sequence change in the HS2-LCR and Ggamma-globin gene promoter region of sickle cell anemia patients.

The fetal hemoglobin (HbF) levels and betaS-globin gene haplotypes of 125 sickle cell anemia patients from Brazil were investigated. We sequenced the Ggamma- and Agamma-globin gene promoters and the DNase I-2 hypersensitive sites in the locus control regions (HS2-LCR) of patients with HbF level disparities as compared to their betaS haplotypes. Sixty-four (51.2%) patients had CAR/Ben genotype; 36 (28.8%) Ben/Ben; 18 (14.4%) CAR/CAR; 2 (1.6%) CAR/Atypical; 2 (1.6%) Ben/Cam; 1 (0.8%) CAR/Cam; 1 (0.8%) CAR/Arab-Indian, and 1 (0.8%) Sen/Atypical. The HS2-LCR sequence analyses demonstrated a c.-10.677G>A change in patients with the Ben haplotype and high HbF levels. The Gg gene promoter sequence analyses showed a c.-157T>C substitution shared by all patients, and a c.-222_-225del related to the Cam haplotype. These results identify new polymorphisms in the HS2-LCR and Gg-globin gene promoter. Further studies are required to determine the correlation between HbF synthesis and the clinical profile of sickle cell anemia patients.

Sequence change in the HS2-LCR and Gg-globin gene promoter region of sickle cell anemia patients

The fetal hemoglobin (HbF) levels and betaS-globin gene haplotypes of 125 sickle cell anemia patients from Brazil were investigated. We sequenced the Gg- and Ag-globin gene promoters and the DNase I-2 hypersensitive sites in the locus control regions (HS2-LCR) of patients with HbF level disparities as compared to their ßS haplotypes. Sixty-four (51.2 percent) patients had CAR/Ben genotype; 36 (28.8 percent) Ben/Ben; 18 (14.4 percent) CAR/CAR; 2 (1.6 percent) CAR/Atypical; 2 (1.6 percent) Ben/Cam; 1 (0.8 percent) CAR/Cam; 1 (0.8 percent) CAR/Arab-Indian, and 1 (0.8 percent) Sen/Atypical. The HS2-LCR sequence analyses demonstrated a c.-10.677G>A change in patients with the Ben haplotype and high HbF levels. The Gg gene promoter sequence analyses showed a c.-157T>C substitution shared by all patients, and a c.-222_-225del related to the Cam haplotype. These results identify new polymorphisms in the HS2-LCR and Gg-globin gene promoter. Further studies are required to determine the correlation between HbF synthesis and the clinical profile of sickle cell anemia patients.

ßS-Haplotypes in sickle cell anemia patients from Salvador, Bahia, Northeastern Brazil

ßS-Globin haplotypes were studied in 80 (160 ßS chromosomes) sickle cell disease patients from Salvador, Brazil, a city with a large population of African origin resulting from the slave trade from Western Africa, mainly from the Bay of Benin. Hematological and hemoglobin analyses were carried out by standard methods. The ßS-haplotypes were determined by PCR and dot-blot techniques. A total of 77 (48.1 percent) chromosomes were characterized as Central African Republic (CAR) haplotype, 73 (45.6 percent) as Benin (BEN), 1 (0.63 percent) as Senegal (SEN), and 9 (5.63 percent) as atypical (Atp). Genotype was CAR/CAR in 17 (21.3 percent) patients, BEN/BEN in 17 (21.3 percent), CAR/BEN in 37 (46.3 percent), BEN/SEN in 1 (1.25 percent), BEN/Atp in 1 (1.25 percent), CAR/Atp in 6 (7.5 percent), and Atp/Atp in 1 (1.25 percent). Hemoglobin concentrations and hematocrit values did not differ among genotype groups but were significantly higher in 25 patients presenting percent fetal hemoglobin ( percentHbF) > or = 10 percent (P = 0.002 and 0.003, respectively). The median HbF concentration was 7.54 ± 4.342 percent for the CAR/CAR genotype, 9.88 ± 3.558 percent for the BEN/BEN genotype, 8.146 ± 4.631 percent for the CAR/BEN genotype, and 4.180 ± 2.250 percent for the CAR/Atp genotype (P = 0.02), although 1 CAR/CAR individual presented an HbF concentration as high as 15 percent. In view of the ethnic and geographical origin of this population, we did not expect a Hardy-Weinberg equilibrium for CAR/CAR and BEN/BEN homozygous haplotypes and a high proportion of heterozygous CAR/BEN haplotypes since the State of Bahia historically received more slaves from Western Africa than from Central Africa

BetaS-haplotypes in sickle cell anemia patients from Salvador, Bahia, Northeastern Brazil.

BetaS-Globin haplotypes were studied in 80 (160 betaS chromosomes) sickle cell disease patients from Salvador, Brazil, a city with a large population of African origin resulting from the slave trade from Western Africa, mainly from the Bay of Benin. Hematological and hemoglobin analyses were carried out by standard methods. The betaS-haplotypes were determined by PCR and dot-blot techniques. A total of 77 (48.1%) chromosomes were characterized as Central African Republic (CAR) haplotype, 73 (45.6%) as Benin (BEN), 1 (0.63%) as Senegal (SEN), and 9 (5.63%) as atypical (Atp). Genotype was CAR/CAR in 17 (21.3%) patients, BEN/BEN in 17 (21.3%), CAR/BEN in 37 (46.3%), BEN/SEN in 1 (1.25%), BEN/Atp in 1 (1.25%), CAR/Atp in 6 (7.5%), and Atp/Atp in 1 (1.25%). Hemoglobin concentrations and hematocrit values did not differ among genotype groups but were significantly higher in 25 patients presenting percent fetal hemoglobin (%HbF) > or = 10% (P = 0.002 and 0.003, respectively). The median HbF concentration was 7.54+/-4.342% for the CAR/CAR genotype, 9.88 3.558% for the BEN/BEN genotype, 8.146 4.631% for the CAR/BEN genotype, and 4.180+/-2.250% for the CAR/Atp genotype (P = 0.02), although 1 CAR/CAR individual presented an HbF concentration as high as 15%. In view of the ethnic and geographical origin of this population, we did not expect a Hardy-Weinberg equilibrium for CAR/CAR and BEN/BEN homozygous haplotypes and a high proportion of heterozygous CAR/BEN haplotypes since the State of Bahia historically received more slaves from Western Africa than from Central Africa.

Nature of plant stimulators in the production of Acetobacter xylinum ("tea fungus") biofilm used in skin therapy.

Caffeine and related xanthines were identified as potent stimulators for the bacterial cellulose production in A. xylinum. These compounds are present in several plants whose infusions are useful as culture-medium supplements for this acetobacterium. The proposed target for these native purine-like inhibitory substances is the novel diguanyl nucleotide phosphodiesterase(s) that participate(s) in the bacterial cellulogenic complex. A better understanding of this feature of A. xylinum physiology may facilitate the preparation of bacterial cellulose pellicles, which are applied as a biotechnological tool in the treatment of skin burns and other dermal injuries.