Haplotypes and polymorphism in the CCR5 gene in sickle cell disease.

Sickle cell disease shows several clinical manifestations in distinct levels of severity. This heterogeneity is due to the haplotype variability associated with the HbS gene, levels of fetal hemoglobin and environmental conditions, which modify the disease expression. Science community believes that the presence of a polymorphism in the CCR5 gene, which is related to chronic inflammatory state, could confer a higher survival rate and a lower number of inflammatory events to these patients since the deletion in CCR5Δ32 would knock out the CCR5 gene. Therefore, this study aimed to identify the haplotypes in ßS and ßC genes, as well as to investigate the presence of the CCR5Δ32 deletion in patients with sickle cell disease. For this purpose, DNA was isolated with the QIAamp DNA Investigator Kit, and PCR was the method chosen to detect the mutant allele CCR5Δ32. The haplotypes in ßS and ßC genes were detected by RFLP with the restriction enzymes XmnI, HindIII, HincII, and HinfI analyzing six polymorphic sites on the ß cluster, succeeded by electrophoresis. The atypical haplotype was the most common (54.3%), followed by Benin (28.6%), Bantu (11.5%), Senegal (2.8%), and Cameroon (2.8%). No patients presented CCR5Δ32 deletion. The increase in the frequency of atypical haplotypes suggests that these patients passed by variation in the genetic pattern from ancestral haplotypes throughout the years.

Genomic ancestry evaluated by ancestry-informative markers in patients with sickle cell disease.

The ß(s) mutation is responsible for the most aggressive form of sickle cell disease, has a predominantly African origin, and arrived in Brazil through the slave trade. However, the Brazilian population is highly miscegenated, underscoring the importance of ancestry-informative markers (AIMs) for the identification of the genetic structure of a population. In this study, we have estimated the genetic contributions of various ethnicities in individuals with sickle cell disease in the microregion of Jequié, Bahia, in Brazil, by using AIMs, and compared the findings to those from a phenotypic characterization. Eight AIMs were analyzed: AT3 (rs3138521), DRD2 (rs1079598), APO (rs3138522), PV92, Sb19.3 (rs3138524), CKM (rs4884), LPL (rs285), and CCR5Δ32 (rs333). Samples were subjected to polymerase chain reaction (PCR) and PCR-restriction fragment length polymorphism. The amplified products were electrophoresed on agarose gels, and the data were statistically analyzed using Genepop, FSTAT 2.9, and Admix3. Phenotypic classification showed a high frequency of mulattos  (85%) in the Brazilian population; however, ancestry-informative markers indicated that 44, 42, and 11% of the population had European, African, and native American ancestries, respectively. The phenotypic classification is justified as a complementary method for the characterization of the genetic ancestry in patients with sickle cell disease, as it confirms the molecular findings regarding ancestry.

Longitudinal differentiation in Melipona mandacaia (Hymenoptera, Meliponini) chromosomes.

Melipona mandacaia is a stingless bee endemic to northeast Brasil. We describe the M. mandacaia karyotype using C-banding technique. fluorochrome staining and treatment with restriction enzymes and discuss the position of this species in the context of the phylogeny of the genus. Melipona mandacaia has 2n = 18 (14 SM + 2 M + 2 A). Heterochromatin was detected in the pericentromeric region of pairs 1, 2 and 8 and in the form of small blocks in the remaining pairs. Staining with base-specific fluorochromes showed that this heterochromatin was rich AT (QM and DAPI), except in the region corresponding to the NOR which was rich GC (CMA3) and was cleaved by the HaeIII enzyme. Melipona mandacaia is a member of Group I Melipona. Treatment with DraI/Giemsa discloses a larger number of bands than treatment with DraI/QM. Pre-cleavage with DraI gave rise to a larger number of bands following QM staining; a circumstance evidently due to a removal of the DNA-protein complex that prevented the association of the fluorochrome with AT-rich DNA. The results highlight the complex nature of heterochromatin.

Silver staining of nucleolar organizer regions (NOR) in some species of Hymenoptera (bees and parasitic wasp) and Coleoptera (lady-beetle).

Adaptations of the nucleolar organizer regions (NOR) banding technique using precipitation of silver salts significantly improved the NOR characterization of some species of hymenopterans and one coleopteran. The bee Melipona marginata (2n = 18) showed one metacentric pair of chromosomes with a NOR in the pericentromeric position. The parasitic wasp Mellitobia australica (2n = 12) also showed one metacentric pair with a strongly Ag-positive NOR. The male lady-beetle Cycloneda sanguinea (2n = 18 + Xy(p)) displayed a NOR on a pair of acrocentric autosomes. In the male Euglossa sp. (a haplodiploid species) (n = 21) the NOR were multiple, and occurred in five chromosomes. In the bee Plebeia sp. 1 (2n = 34) the NOR seemed restricted to one of the homologues of a metacentric pair. The systematic advances brought out by using this technique in the context of current theories of karyotypic evolution of these taxa are described and discussed.

The karyotype of the parasitoid Chelonus insularis Cresson (Hymenoptera, Braconidae, Cheloninae).

The karyotype of Chelonus insularis (Hymenoptera, Braconidae, Cheloninae) is described. The males show an haploid number of seven chromosomes and the females a diploid number of fourteen chromosomes, confirming haplo-diploid sex determination. Comparisons of these results with karyotypes of other species of the same family were done and a possible mechanism involved in the karyotype evolution of this species is discussed.

The karyotype of the parasitoid Chenolus insularis Cresson (Hymenoptera, Braconidae, Cheloninae)

The karyotype of Chelomus insularis (Hymenoptera, Braconidae, Cheloninae) is described. The males show an haploid number of fourteen chromosomes, confirming haplo-diploid sex determination. Comparisons of these results with karyotypes of other species of the same family were done and a possible mechanism involved in the karyotype evolution of this species is discussed.

Rat kidney band 3 mRNA modulation in chronic respiratory acidosis.

Recent evidence indicates the existence of a protein related to the erythroid chloride-bicarbonate exchanger (band 3 protein) in the basolateral aspect of type A intercalated cells of the distal nephron. To probe the possible participation of this transporter in the renal adaptation to chronic hypercapnia, we examined the steady-state abundance of band 3 mRNA in the kidney during respiratory acidosis of variable duration. Total RNA was isolated from renal cortex and medulla of rats maintained in a 10% CO2 atmosphere for 2 or 5 days and from contemporaneous controls. The RNA was analyzed by Northern blot assay using cDNA probes for band 3 and beta-actin genes. Using a 3' cDNA probe encoding the membrane-associated domain of band 3 protein that is involved in anion exchange, we found a two- to threefold increase in steady-state mRNA levels (whether or not correction for the beta-actin signals was applied) in renal cortex and medulla at 5 days of hypercapnia. Similar, but less definitive, increases were observed at the 2-day time point. Using a 5' cDNA probe encoding an erythroid-protein segment absent from the kidney band 3 major transcript, we detected meager hybridization in renal tissue and no measurable variation during hypercapnia. Use of splenic RNA as a positive control for the 5' probe disclosed marked reduction of band 3 mRNA levels in hypercapnia, indicating organ specificity of band 3 gene expression. We conclude that steady-state levels of kidney band 3 mRNA increase in chronic respiratory acidosis as a result of transcriptional or posttranscriptional regulatory mechanisms. This adaptation might be involved in the augmentation of renal acidification characteristic of chronic hypercapnia.

Infecçäo por Listeria monocytogenes pós-transplante renal: relato de seis casos / Infection by Listeria monocytogenes following renal transplantation: report of 6 cases

Säo relatados 6 casos de listeriose em pacientes transplantados renais, que ocorreram entre 13 dias e 57 meses após iniciarem imunossupressäo clássica, sendo 3 casos classificados como meningite, 2 casos como meningoencefalite e 1 caso como bacteremia. Houve um óbito e os 5 pacientes restantes apresentaram boa evoluçäo. Com dados adicionais da literatura, säo discutidos a epidemiologia, o diagnóstico e tratamento, da listeriose pós-transplante renal