Bonafide, type-specific human papillomavirus persistence among HIV-positive pregnant women: predictive value for cytological abnormalities, a longitudinal cohort study

This study investigated the rate of human papillomavirus (HPV) persistence, associated risk factors, and predictors of cytological alteration outcomes in a cohort of human immunodeficiency virus-infected pregnant women over an 18-month period. HPV was typed through L1 gene sequencing in cervical smears collected during gestation and at 12 months after delivery. Outcomes were defined as nonpersistence (clearance of the HPV in the 2nd sample), re-infection (detection of different types of HPV in the 2 samples), and type-specific HPV persistence (the same HPV type found in both samples). An unfavourable cytological outcome was considered when the second exam showed progression to squamous intraepithelial lesion or high squamous intraepithelial lesion. Ninety patients were studied. HPV DNA persistence occurred in 50% of the cases composed of type-specific persistence (30%) or re-infection (20%). A low CD4+T-cell count at entry was a risk factor for type-specific, re-infection, or HPV DNA persistence. The odds ratio (OR) was almost three times higher in the type-specific group when compared with the re-infection group (OR = 2.8; 95% confidence interval: 0.43-22.79). Our findings show that bonafide (type-specific) HPV persistence is a stronger predictor for the development of cytological abnormalities, highlighting the need for HPV typing as opposed to HPV DNA testing in the clinical setting.

Use of V H, D and J H immunoglobulin gene segments in Brazilian patients with chronic lymphocytic leukaemia (CLL)

Chronic lymphocytic leukaemia (CLL) is a haematological malignancy for which reliable prognostic markers are needed in view of its clinical heterogeneity. In approximately 50 percent of CLL patients, immunoglobulin (Ig) rearrangements are modified by somatic hypermutation (SHM), a process that represents a reliable prognostic indicator of favourable progression. In this study, we investigated SHM in 37 Brazilian CLL patients and identified the preferential involvement of specific immunoglobulin gene families and segments through PCR-amplified fragments or subcloned fragments. Forty-one rearrangements were observed and 37 of them were functional. A 98 percent homology cut-off with germinal sequences showed 18 patients (48.7 percent) with SHM. Unmutated cases showed a poorer clinical outcome. V H3 was the most frequent V H family, followed by V H4. The V H4-39 segment was the most frequently used, mainly in unmutated cases, while the V H3 family was predominant in mutated cases. The D3 and J H4/J H6 families were the most frequently observed.

Population structure and genetic variability of mainland and insular populations of the Neotropical water rat, Nectomys squamipes (Rodentia, Sigmodontinae)

Seven microsatellite loci were used to investigate the genetic variability and structure of six mainland and two island populations of the Neotropical water rat Nectomys squamipes, a South American semi-aquatic rodent species with a wide distribution. High levels of variability were found within mainland populations while island populations were less variable but the more differentiated in respect to allele number and frequency. The time of biological divergence between mainland and island populations coincided with geological data. A significant geographic structure was found in mainland populations (q = 0.099; r = 0.086) although the degree of differentiation was relatively low in respect to the distance between surveyed localities (24 to 740 km). Genetic and geographic distances were not positively correlated as previously found with random amplified polymorphic DNA (RAPD) markers. Significant but low genetic differentiation in the mainland and lack of isolation by distance can be explained by large population size and/or recent population expansion. Additionally, the agreement between the age of geologic events (sea level fluctuations) and divergence times for insular populations points to a good reference for molecular clock calibration to associate recent environmental changes and the distribution pattern of small mammals in the Brazilian Atlantic Forest

Adenosine deaminase isozyme variation inn Alouatta belzebul with review of data from other primates

Dados sobre os tipos de adenosina deaminase säo reportados em 1067 espécimes de Alouatta belzebul belzebul procedentes da regiäo do rio Tocantins, na Amazônia Brasileira. Oito fenótipos eletroforéticos foram observados, codificados provavelmente por 4 alelos. O grau de polimorfismo observado pode ser classificado como moderno. Dados da literatura indicam que cerca de 40% das espécies de macacos do Velho Mundo e 2 espécies do Novo Mundo säo monomórficas para este locus, e nas espécies ocorre variaçäo, 2-3 alelos säo observados. Em Alouatta belzebul o cromossomo Y está translocado para um autossomo. O locus ADA näo está em desequilíbrio de ligaçäo com os genes determinantes do sexo masculino, e portanto, ou este locus näo está localizado no autossomo indicado, ou está distante da regiäo na qual estes genes foram relocados

Chromosomes and spermatozoa of the great apes and man

The chromosome complement of four species phylogenetically related to man, the chimpanzee (Pan troglodytes), the pygmy chimpanzee (Pan paniscus), the gorilla (Gorilla gorilla), and the orangutan (Pongo pygmaeus) have been analysed with chromosome banding techiniques and compared to the human chomosome complement. This has shown remarkable homologies between species, and presumed mechanism of chromosome evolution have been proposed. Chromosome heteromorphism in the great apes have been compared to those found in human populations, and most o them affected the distribution or the amount of constitutive heterochromatin and/or brilliantly fluorescent material, a situation comparable to man where such variation have been established as chromossome polymorphisms. However, a balanced polymorphic structural rearregement involving large segments of euchromatic material has been found in two populations of orangutan. This rearrangement consisted of two pericentric inversions, one inside the other, comprising an unusual kind of chromosome polymorphism in mammalian populations. Moreover, it showed that pericentric inversions, the most probable chromosome rearrangements in the phylogeny of the chromosome of man and the great apes, might not necessarialy be restricted by infertility barriers, but may spread successfully in the popluation. The patterns of late replication of the chromossome of the great apes and man have been compared, using BUrd as a thymidine substitute in the cell cycle. This has show remarkable similarities in the patters of the pattehumam of late replication between species, and, as in the human chromosome, most regions of late replication in the chromosome of the great apes corresponded to areas of positive G-banding...