Markers of human immunodeficiency virus infection in pediatric bronchoalveolar lavage samples.

Pulmonary cells and fluid obtained by bronchoalveolar lavage (BAL) from 19 pediatric acquired immunodeficiency syndrome (AIDS) patients with pneumonia were examined for markers of human immunodeficiency virus (HIV-1) infection. The HIV-1 DNA was detected in BAL cells by polymerase chain reaction (PCR) in 14 of 15 patients (93.3 percent). Immunostaining of cytocentrifuged cell preparations of six specimens revealed that HIV-1 antigen was associated with from five percent to 95 percent of the alveolar macrophages. Analysis of the 22 cell-free BAL fluids by enzyme immunoassay (EIA) showed that samples from three patients (15.8 percent) contained HIV-1 p24 antigen. One sample, with a dilution factor of 15.1 relative to serum, contained a markedly elevated antigen concentration (106 pg per ml) compared to the serum concentration (41.6 pg per ml). Antibodies to HIV-1 were present in the BAL fluids of six patients (31.6 percent) at levels detectable by EIA. By Western blot analysis, three samples yielded more intense gp120 bands compared to bands observed with matched serum samples. Our results suggest that HIV-1 and antibodies to this virus are frequently present in the lungs of children with AIDS and that the serum antigen and antibody profile of some patients does not reflect local pulmonary levels.     

Non-specific X-linked semidominant mental retardation by mutations in a Rab GDP-dissociation inhibitor

Non-specific X-linked mental retardation (MRX) is a very common disorder which affects approximately 1 in 600 males. Despite this high frequency, little is known about the molecular defects underlying this disorder, mainly because of the clinical and genetic heterogeneity which is evident from linkage studies. Recently, a collaborative study using the candidate gene approach demonstrated the presence of mutations in GDIalpha, a Rab GDP-dissociation inhibitor encoded by a gene localized in Xq28, associated with non-specific mental retardation. GDIalpha is mainly a brain-specific protein that plays a critical role in the recycling of Rab GTPases involved in membrane vesicular transport. The study presented here was designed to assess the prevalence of mutations in the GDIalpha in mentally retarded patients and to discuss the clinical phenotypes observed in affected individuals. Mutation screening of the whole coding region of the GDIalpha gene, using a combination of denaturing gradient gel electrophoresis and direct sequencing, was carried out in 164 patients found negative for expansions across the FRAXA GCC repeat. In addition to the nonsense mutation recently reported in MRX48, we have identified a novel missense mutation in exon 11 of the GDIalpha gene in one familial form of non-specific mental retardation. In this family (family R), all affected males show moderate to severe mental retardation, and the X-linked semidominant inheritance is strongly suggested by the severe phenotypes in males with respect to mildly affected females or unaffected obligatory carriers. This study showed that the prevalence of GDIalpha mutations in non-specific mental retardation could be estimated to be 0.5-1%, and molecular diagnosis and genetic counselling in some cases of non-specific mental handicap can now be provided.      

Primary non-Hodgkin''s lymphoma and pseudolymphoma of lung: A study of 161 patients

The authors studied 161 cases of primary non-Hodgkin's lymphomas and pseudolymphomas of lung. Small lymphocytic proliferations, which they believe to be lymphomas, constituted 31.6 per cent of cases; plasmacytoid lymphocytic and small cleaved follicular center cell lymphomas (Lukes-Collins system), 22.4 and 11.8 per cent of cases, respectively; and the remaining follicular center cell lymphomas and B-immunoblastic sarcomas, 5.6 per cent of cases. Pseudolymphomas constituted 14 per cent of cases. Most patients were elderly and asymptomatic; in most cases a solitary nodule or infiltrate was observed on a chest radiograph. Radiographic evidence of effusion was found in both lymphomas and pseudolymphomas, but hilar adenopathy was restricted to lymphomas. A few peribronchial reactive germinal centers and intralesional giant cells/granulomas were seen frequently in unequivocal lymphomas, so their presence cannot be used to exclude neoplasia. A generally monomorphic cell population and invasion of bronchial cartilage or visceral pleura are suggestive of malignancy, whereas primitive cytologic appearance and invasion of lymph nodes or parietal pleura are pathognomonic of malignancy. Diffusely admixed mature lymphocytes and plasma cells with numerous reactive follicles suggest pseudolymphomas. Immunologic determination of clonality may be diagnostically definitive. Most localized lesions in lung were treated by surgical resection, whereas in cases of extensive pulmonary disease, biopsies were performed and patients were treated by chemotherapy or irradiation. Both lymphomas and pseudolymphomas recurred, most often within three years. Pseudolymphoma recurred only in lung. When distant spread of lymphoma occurred, it commonly involved extranodal sites. Only 18 of 101 patients with lymphoma died with or of tumor, and no patient with pseudolymphoma died of disease. Neither histologic subtype among the "small cell" lymphoid lymphomas nor the presence of regional node involvement was prognostically significant, but pleural effusion on the initial chest radiograph was a significant predictor of both recurrence and mortality.     

Incidental encoding of emotional pictures: Affective bias studied through event related brain potentials

Emotional stimuli are better remembered than neutral stimuli. Most of the studies taking into account this emotional bias refer to explicit memory, use behavioral measures of the recall and predict better recall of negative stimuli. The few studies taking into account implicit memory and the valence emotional dimension are inconclusive on the effect of the stimulus' emotional valence. In the present study, 120 pictures (30 positive, 30 negative, 30 relaxing and 30 neutral) were shown to, and assessed by, 28 participants (study phase). Subsequently, event related brain potentials (ERPs) were recorded during the presentation of 120 new (shown for the first time) and 120 old (already shown in the study phase) pictures (test phase). No explicit instructions or clues related to recovery were given to participants, and a distractor task was employed, in order to maintain implicit the memory assessment. As expected from other studies' data, our results showed that old stimuli elicited an enhanced late positive component 450 ms after stimulus onset (repetition effect). Moreover, this effect was modulated by the stimuli's emotional valence, since the most positively valenced stimuli were associated with a decreased repetition effect with respect to the most negatively valenced stimuli. This effect was located at ventromedial prefrontal cortex. These results suggest the existence of a valence-mediated bias in implicit memory.     

Stapedectomy: fenestration versus partial or complete footplate removal

The introduction of stapes surgery in the 1950s has brought about numerous changes to the field. The designed changes in the prosthesis as well composition of the prosthesis has influenced stapes surgery. The introduction of microdrills and lasers has also had some dramatic influences in the field. Stapes surgery can be divided into large fenestra technique or small fenestra technique. There are various proponents to each technique, with reported excellent results for each technique. The long-term hearing results are comparable with each technique. This article reviews the long-term results for large fenestra and small fenestra surgery.     

Efficacy and safety of a vaccine against human leptospirosis in Cuba]

OBJECTIVES: To evaluate the efficacy of vax-SPIRAL, a Cuban vaccine against leptospirosis, and to provide additional information concerning the safety of this vaccine (which was developed by Cuba's Finlay Institute). METHODS: This phase III efficacy trial of vax-SPIRAL was controlled, randomized, and double blind. The control vaccine used for the trial was Heberbiovac-HB (Heber Biotec, Cuba), a recombinant hepatitis B vaccine. The randomization unit for allocating persons to the study group or the control group were 523 family physician offices in the selected municipalities. The study covered the entire population of males and females from 20 to 64 years old who voluntarily agreed to participate, from the municipalities of Ranchuelo, Quemado, Santo Domingo, Encrucijada, Corralillo, Cifuentes, and Camajuaní, which are in the province of Villa Clara, in the central region of Cuba. The vaccinations were given in the physicians' offices between February and July 1998, with an interval of 6 weeks between the two doses. The follow-up period was 12 months. A case was considered positive if a person who had received the two doses of the vaccine became ill with leptospirosis more than 21 days after receiving the second dose, with the diagnosis confirmed through serological and microbiological methods. We calculated the efficacy of the vaccine and the relative risk of becoming ill with leptospirosis after the vaccination. For the safety study, two persons were chosen at random from among the individuals vaccinated at the office of each physician participating in the study. Follow-up of local and systemic adverse reactions was carried out by the family physicians during the seven days after the application of each dose. The level of statistical significance was set at 0.05. RESULTS: A total of 101 832 persons were vaccinated, with 50 354 of them (49.4%) receiving the leptospirosis vaccine and 51 478 of them (50.6%) receiving the control vaccine. The efficacy of the vax-SPIRAL vaccine was 78.1% (95% confidence interval (CI): 59.2% to 88.3%), and the relative risk of becoming ill with leptospirosis after receiving the leptospirosis vaccine was 0.22 (95% CI: 0.12 to 0.41). General discomfort was the most frequent systemic adverse reaction, and mild spontaneous pain at the injection site was the most frequent local effect. The local and systemic adverse reactions were both more frequent in the study group than in the control group (P = 0.003). There were no serious adverse events. CONCLUSION: The vax-SPIRAL vaccine proved to be safe and efficacious for leptospirosis control. The vaccine is recommended for use in preventing this disease among groups at risk of contracting it.