Visual acuity and retinal function in patients with Bardet-Biedl syndrome

OBJECTIVE:

Bardet-Biedl syndrome is a genetic, multisystem disorder that causes severe visual impairment. This condition is characterized by retinal dystrophy, obesity, digit anomalies, renal disease, and hypogonadism. The purpose of this study was to analyze visual acuity and full-field electroretinogram findings in patients with the Bardet-Biedl syndrome phenotype.

METHODS:

The visual acuity of a group of 23 patients (15 males) with ages ranging from 6-36 years (mean = 15.8±6.4; median = 14.7) was assessed. Retinal function was evaluated by full-field electroretinography, and dark-adapted thresholds were assessed.

RESULTS:

Visual acuity in the better-seeing eye was 20/40 or better in 5 patients (21.7%), 20/50-20/150 in 13 (56.5%) patients, 20/200-20/400 in 2 (8.7%) patients and worse than 20/400 in one (4.3%) patient. The mean acuity in the better-seeing eye was 0.7±0.6 logMAR (20/100, Snellen equivalent). Scotopic rod and maximal responses were non-detectable in 21 (91.3%) patients, and cone responses were non-detectable in 15 (65.2%) patients. Elevated dark-adapted visual thresholds were observed in all 19 patients who were able to be assessed, with 10 (52.6%) patients having thresholds greater than 30 dB.

CONCLUSIONS:

In a relatively young cohort of patients with Bardet-Biedl syndrome, only 21% had 20/40 or better vision. ERG scotopic responses were absent in the majority of cases, with cone responses being observed in less than half of cases. These findings showed the early deleterious effects in retinal function and visual acuity caused by this condition.     

Imaging Trypanosoma cruzi within tissues from chagasic patients using confocal microscopy with monoclonal antibodies

Confocal fluorescence microscopy combined with differential interference contrast imaging of tissues from chagasic patients enabled the unequivocal identification of the parasite Trypanosoma cruzi. Using different monoclonal antibodies that indicate the parasite form and replication stage in conjunction with DNA labelling, specimens derived from distinct clinical forms of the disease were examined. Intracellular amastigote forms of the parasite were clearly detected in heart, brain, skin, lung, and kidney. Dividing amastigotes as well as trypomastigote forms were recognized in samples obtained from patients undergoing either acute-phase or some form of reactivation caused by immunosuppression. Received: 22 December 1998 / Accepted: 11 March 1999     

First report of typical Brazilian Toxoplasma gondii genotypes from isolates of free-range chickens (Gallus gallus domesticus) circulating in the state of Paraíba,Northeast Brazil

This study evaluated, for the first time, the genetic diversity of Toxoplasma gondii isolates from free-range chickens from the state of Paraíba, Northeast Brazil. Tissue samples from 33 chickens from properties in five municipalities of Paraíba (Esperança, Olho d’Água, Malta, Monteiro, and Patos) were bioassayed in mice. The brains of mice infected with T. gondii cysts were used for DNA extraction and genotyping. Genotyping was performed using 11 PCR-RFLP markers and 15 microsatellite (MS) markers. Complete genotyping results were obtained for 29 isolates, with nine genotypes detected by RFLP and 15 genotypes identified by MS. Three genotypes (#273, #274, and #277) have only been recently identified from pigs in the region. Brazilian clonal types BrII and BrIII were identified from one isolate each. Clonal types I, II, and III were not detected by RFLP. Genotype #13 (Caribbean 1), detected in 48.3% (14/29) of isolates from four of the five municipalities investigated, was the most prevalent genotype in the state of Paraíba. However, the MS analysis showed that of these 14 isolates, only four were unique genotypes, and considering the distance between the municipalities from where they were collected, it is possible that only seven are independent isolates while the others are clones. The other genotypes were restricted to different microregions. The results indicate that the Caribbean 1 lineage of T. gondii is circulating widely in Northeast Brazil. The genotypic diversity of T. gondii in the state of Paraíba is high, and microsatellite analysis revealed this diversity with higher resolution than PCR-RFLP.

     

Pathogenicity of Nc-Bahia and Nc-1 strains of Neospora caninum in experimentally infected cows and buffaloes in early pregnancy

Neospora caninum is a protozoan parasite known as an important cause of bovine abortion worldwide. Little is currently known about how different strains of N. caninum vary in their pathogenicity. In this study, we compared a Brazilian strain, Nc-Bahia, with the first isolate of this coccidian, Nc-1. Eight cows and seven buffaloes were submitted to fixed-time artificial insemination protocols for a better control of pregnancy. Group 1 was inoculated with Nc-Bahia (n?=?8; five cows and three buffaloes), and Group 2 was inoculated with Nc-1 (n?=?5; two cows and three buffaloes). One nonpregnant female of each species was left uninfected as sentinel controls for potential environmental infection. All inoculated animals received 5?×?10⁸ tachyzoites of N. caninum, by intravenous route, on the 70th day of gestation. Uninfected animals remained seronegative throughout the experiment, indicating no exogenous infection, whereas all inoculated animals became seropositive to N. caninum. In Group 1, abortion was found in only one cow on 42 days postinfection (dpi; frequency of abortion?=?12.5 %), whilst all animals from Group 2 aborted on 35 dpi (frequency of abortion?=?100 %). Parasite DNA was detected by seminested PCR in maternal, foetal and placental tissues, confirming vertical transmission in Groups 1 and 2, although histological lesions had different frequencies and degrees of severity between the groups. There was evidence of lower pathogenicity of Nc-Bahia compared to Nc-1 when used in experimental infection, as it caused fewer abortions, as well as less frequent and milder histological lesions. This was the first time Nc-Bahia has been used for experimental infection.     

Diversity among Tacaribe serocomplex viruses (Family Arenaviridae) associated with the southern plains woodrat (Neotoma micropus)

The southern plains woodrat (Neotoma micropus) is the principal host of Catarina virus in southern Texas and a natural host of other North American Tacaribe serocomplex viruses. The objectives of this study were to increase our knowledge of the genetic diversity among Tacaribe serocomplex viruses associated with N. micropus and to define better the natural host relationships of these viruses. Pairwise comparisons of complete glycoprotein precursor gene sequences and complete nucleocapsid protein gene sequences revealed a high level of genetic diversity among Tacaribe serocomplex viruses associated with N. micropus in western Oklahoma, southern New Mexico, and northern and southern Texas. Collectively, the results of Bayesian analyses of nucleotide sequences and pairwise comparisons of amino acid sequences confirmed that the arenaviruses associated with N. micropus in Oklahoma and New Mexico should be included in the Whitewater Arroyo species complex, and indicated that that the arenaviruses associated with N. micropus in northern Texas are strains of a novel arenaviral species – tentatively named “Middle Pease River virus”. Together, the results of assays for arenavirus and assays for anti-arenavirus antibody in 54 southern plains woodrats and 325 other rodents captured at 2 localities suggested that the southern plains woodrat is the principal host of Middle Pease River virus in northern Texas.     

The genomic analysis of rubella virus detected from outbreak and sporadic cases in Rio de Janeiro state, Brazil.

BACKGROUND: The molecular epidemiology of rubella virus (RV) based on the analysis of the viral E1 gene sequences indicated the existence of two genotypes that differ from each other by 8 to 10% in their nucleotide sequences: genotype I is present in Europe, North America and Asia; and genotype II is present only in Asia. OBJECTIVES: The purpose of the study was to identify the RV genotypes circulating in Brazil. STUDY DESIGN: In this study, we analysed 86 clinical samples collected between 1996 and 1999 during a rubella outbreak and from sporadic cases of rubella in Rio de Janeiro State. For the molecular characterisation of RV strains we have used PCR/nested amplification and direct sequencing of a 513-nucleotide region of the E1 gene. RESULTS: The E1 gene sequences of 14 RVs were obtained and were assigned to two lineages, both within genotype I. The percentage divergence of nucleotide sequence ranged from 3.4 to 5.1% between these two lineages. These results were in agreement with the pattern of variation observed among the sequences obtained from other lineages of RV. CONCLUSIONS: This work demonstrated that two new lineages of RV circulated simultaneously between the years 1996 and 1999 in the state of Rio de Janeiro. These results provided new approaches for monitoring the progress of vaccination efforts in Brazil.     

Study of lymphocyte subpopulations in bone marrow in a model of protein–energy malnutrition

ObjectiveProtein–energy malnutrition (PEM) is an important public health problem affecting millions of people worldwide. Hematopoietic tissue requires a high nutrient supply, and a reduction in leukocytes, especially lymphocytes, suggests that some nutritional deficiencies might be altering bone marrow function and decreasing its ability to produce lymphocytes. In this study, we evaluated the effect that PEM has on lymphocyte subtypes and the cell cycle of CD5⁺ cells.MethodsSwiss mice were subjected to PEM using a low-protein diet containing 4% protein. When the experimental group had lost about 20% of their original body weight, we collected blood and bone marrow cells and evaluated the hemogram, the myelogram, bone marrow lymphoid markers using flow cytometry, and the cell cycle in CD5⁺ bone marrow.ResultsMalnourished animals presented anemia, reticulocytopenia, and leukopenia with lymphopenia. The bone marrow was hypocellular, and flow cytometric analyses of bone marrow cells showed cells that were CD45⁺ (91.2%), CD2⁺ (84.9%), CD5⁺ (37.3%), CD3⁺ (23.5%), CD19⁺ (43.3%), CD22⁺ (34.7%), CD19⁺/CD2⁺ (51.2%), CD19⁺/CD3⁺ (24.0%), CD19⁺/CD5⁺ (13.2%), CD22⁺/CD2⁺ (40.1%), CD22⁺/CD3⁺ (30.3%), and CD22⁺/CD5⁺ (1.1%) in malnourished animals and CD45⁺ (97.5%), CD2⁺ (42.9%), CD5⁺ (91.5%), CD3⁺ (92.0%), CD19⁺ (52.0%), CD22⁺ (75.6%), CD19⁺/CD2⁺ (62.0%), CD19⁺/CD3⁺ (55.4%), CD19⁺/CD5⁺ (6.7%), CD22⁺/CD2⁺ (70.3%), CD22⁺/CD3⁺ (55.9%), and CD22⁺/CD5⁺ (8.4%) in control animals. Malnourished animals also presented more CD5⁺ cells in the G0 phase of cell cycle development.ConclusionMalnourished animals presented bone marrow hypoplasia, maturation interruption, prominent lymphopenia with depletion in the lymphoid lineage, and changes in cellular development. We suggest that these changes are some of the primary causes of lymphopenia in cases of PEM and partly explain the increase in susceptibility to infections found in malnourished individuals.     

Croton cajucara crude extract and isolated terpenes: activity on Trypanosoma cruzi

Croton cajucara is a plant found in the Amazon region and is known for its medicinal properties. The effects of the methanolic extract of the stem bark of C. cajucara (MCC) and of the isolated terpenes, trans-dehydrocrotonin (t-DCTN) and acetyl aleuritolic acid (AAA), were investigated using four isolates of Trypanosoma cruzi. In assays with trypomastigotes, the extract was more active than the isolated compounds, presenting IC₅₀ in the range of 10 to 50 μg/mL. The trypanocidal effect of MCC, AAA and benznidazole was significantly higher in the GLT291 and C45 strains, which were recently isolated from wild animals. MCC and AAA caused a dose-dependent inhibition of epimastigote proliferation. In assays using intracellular amastigotes, AAA and MCC reduced the percent of infection and the endocytic index after 96 h of treatment, at concentrations that were non-toxic to the host cells. MCC inhibited the trypanothione reductase pathway in both epimastigotes and trypomastigotes of all the subpopulations. The absence of AAA activity on the trypanothione reductase pathway in epimastigotes of Dm28c suggests heterogeneity of the biochemical profile between this clone and the three strains. Epimastigotes and trypomastigotes (GLT291) were treated for 24 h with MCC or AAA, and both induced alterations of the plasma membrane, while AAA-treated epimastigotes also displayed mitochondrial damage.     

Immune cellular parameters of leprosy and human immunodeficiency virus-1 co-infected subjects

Leprosy and human immunodeficiency virus-1 (HIV-1) are examples of human infections where interactions between the pathogen and the host cellular immunity determine the clinical manifestations of disease. Hence, a significant immunopathological interaction between HIV-1 and leprosy might be expected. In the present study we explored several aspects of cellular immunity in patients co-infected with HIV-1 and Mycobacterium leprae. Twenty-eight individuals were studied, comprising four groups: healthy controls, HIV-1 and M. leprae co-infection, HIV-1 mono-infection, and M. leprae mono-infection. Subjects in the mono-infection and co-infection groups were matched as far as possible for bacillary load and HIV disease status, as appropriate. Peripheral blood mononuclear cells (PBMC) were analysed using six- and seven-colour flow cytometry to evaluate T-cell subpopulations and their activation status, dendritic cell (DC) distribution phenotypes and expression of IL-4 by T cells. The co-infected group exhibited lower CD4 : CD8 ratios, higher levels of CD8⁺ T-cell activation, increased Vδ1 : Vδ2 T cell ratios and decreased percentages of plasmacytoid DC, compared with HIV-1 mono-infected subjects. Across infected groups, IL-4 production by CD4⁺ T lymphocytes was positively correlated with the percentage of effector memory CD4⁺ T cells, suggesting antigenically driven differentiation of this population of T cells in both HIV-1 and M. leprae infections. Co-infection with M. leprae may exacerbate the immunopathology of HIV-1 disease. A T helper 2 (Th2) bias in the CD4⁺ T-cell response was evident in both HIV-1 infection and leprosy, but no additive effect was apparent in co-infected patients.     

Ovarian stripping versus cystectomy: recurrence of endometriosis and pregnancy rate

Purpose

To compare two different surgical techniques, stripping or cystectomy, in patients treated with the same post-operative medical therapy in terms of recurrence of endometrioma, recurrence of pain and spontaneous pregnancy rate within 2 years from surgery.

Methods

The inclusion criteria of this study were: (1) 25–40 years old; (2) ovarian endometrioma more than 3 cm of diameter detected by transvaginal ultrasonography (3) regular menstrual cycle (4) post-operative treatment with GnRH analogs, (5) tubal patency assessed by laparoscopic chromopertubation (6) normal human semen characteristics. Exclusion criteria were uterine myoma, previous medical treatment for endometriosis, presence of adenomyosis, previous surgery of ovarian endometrioma, multiple cysts, bilateral involvement, co-existence of deep endometriosis. Patients were assigned to two study groups: group A (N = 45) patients undergoing stripping technique and group B (N = 64) patients undergoing cystectomy technique for ovarian endometrioma.

Results

In group B the percentage of ultrasonographic recurrence (15.4 %, N = 15) is much lower than in group A (55.6 %, N = 25). (p value 0.001). In group B the percentage of symptomatic recurrence (21.8 %, N = 14) is much lower than in group A (53.3 %, N = 24) (p value 0.001). Spontaneous pregnancy rate in group A patients was of 4.4 % (N = 2) and in group B 22.3 % (N = 21), (p value 0.0072). However, the percentage of specimen with adjacent healthy ovarian tissue was lower in group A (26.6 %) than in group B (50 %) (p value 0.01).

Conclusions

Among the different treatment options for surgical treatment of ovarian endometrioma, in our experience cystectomy appears to be the most appropriate treatment, both in terms of recurrence and pregnancy rate.