Malaria epidemiology in the Pakaanóva (Wari') Indians, Brazilian Amazon

This paper reports the results of a longitudinal study of malaria incidence (1998-2002) among the Pakaanóva (Wari') Indians, Brazilian southwest Amazon region, based on data routinely gathered by Brazilian National Health Foundation outposts network in conjunction with the Indian health service. Malaria is present yearlong in the Pakaanóva. Statistically significant differences between seasons or months were not noticed. A total of 1933 cases of malaria were diagnosed in the Pakaanóva during this period. The P. vivax / P. falciparum ratio was 3.4. P. vivax accounted for 76.5% of the cases. Infections with P. malariae were not recorded. Incidence rates did not differ by sex. Most malaria cases were reported in children < 10 years old (45%). About one fourth of all cases were diagnosed on women 10-40 years old. An entomological survey carried out at two Pakaanóva villages yielded a total of 3.232 specimens of anophelines. Anopheles darlingi predominated (94.4%). Most specimens were captured outdoors and peak activity hours were noted at early evening and just before sunrise. It was observed that Pakaanóva cultural practices may facilitate outdoor exposure of individuals of both sexes and all age groups during peak hours of mosquito activities (e.g., coming to the river early in the morning for bathing or to draw water, fishing, engaging in hunting camps, etc). In a context in which anophelines are ubiquitous and predominantly exophilic, and humans of both sexes and all ages are prone to outdoor activities during peak mosquito activity hours, malaria is likely to remain endemic in the Pakaanóva, thus requiring the development of alternative control strategies that are culturally and ecologically sensitive.     

Phenotypic and genotypic analyses of enterohemorrhagic Escherichia coli O145 strains from patients in Germany

Enterohemorrhagic Escherichia coli (EHEC) strains of serogroup O145 are emerging as causes of diarrhea and the hemolytic-uremic syndrome. However, there have been few genetic analyses of this EHEC group. We investigated the serotypes, virulence genes, plasmid profiles, pulsed-field gel electrophoresis (PFGE) patterns, and genetic variability of the fliC and eae genes in 120 EHEC O145 strains isolated from cases of hemolytic-uremic syndrome (n = 24) or diarrhea (n = 96) in Germany between 1996 and 2002. Three isolates belonged to serotype O145:H28, one to serotype O145:H25, and 116 were nonmotile (O145:H(-)). One hundred fourteen of the nonmotile strains shared fliC restriction fragment length polymorphism (RFLP) patterns identical to that of the O145:H28 strains. The remaining two nonmotile strains displayed a fliC-RFLP pattern identical to that of the O145:H25 strain. Each of the 117 strains with the fliC-RFLP(H28) pattern harbored eae gamma, whereas the three strains with the fliC-RFLP(H25) pattern possessed eae beta. Five different stx genotypes, six combinations of plasmid-encoded putative virulence genes, 29 plasmid profiles, and 47 PFGE types were identified. Strains within some of the PFGE types could be further subtyped by means of distinct plasmid profiles. These data demonstrate that the EHEC O145 serogroup is comprised of two different serotypes that possess distinct eae types. The heterogeneity of EHEC O145 strains at the chromosomal and plasmid level, in particular the high diversity in PFGE patterns, provides a basis for molecular subtyping of these pathogens.     

Pulmonary and mediastinal "sarcoidosis" following surgical resection of cancer

Previous reports indicate that enlarged hilar and mediastinal lymph nodes caused by sarcoid-like reactions may develop after curative resection of cancer, and their presence does not necessarily denote neoplastic recurrence. Reports further suggest that coexisting pulmonary infiltrates in this setting may be related to sarcoidosis. In this study, we describe two patients who had resected lung and gastric cancer and who later developed pulmonary interstitial infiltrate, concurrent with progressive mediastinal lymphadenopathy initially thought to be caused by intrathoracic dissemination of their cancer. These changes were shown by open lung biopsy to be a benign, granulomatous reaction interpreted as sarcoidosis. Thus, it is important to recognize this clinical pattern when pulmonary infiltrates develop after complete treatment of cancer in an otherwise relapse-free patient and to encourage lung or lymph node biopsy in these particular settings in order to confirm a sarcoid-like reaction, thereby avoiding unnecessary chemotherapy for presumed tumor recurrence.     

Autonomic nervous control of the heart rate response to dynamic incremental exercise: evaluation of the Rosenblueth-Simeone model

Summary To evaluate the validity of the Rosenblueth-Simeone model for the heart rate response to incremental dynamic exercise, 11 healthy men performed maximal exercise tests on a cycle ergometer after administration of placebo, propranolol, atropine or both propranolol and atropine. The model showed that the influence of sympathetic activity on heart rate increased at intensities up to those which resulted in a heart rate 70% maximal heart rate on placebo, and levelled off at higher intensities, while there was a progressive withdrawal of the parasympathetic activity. The ratio between heart rate predicted by the model and the recorded heart rate following placebo treatment tended to be less than 1.0 at lower exercise intensities, and approached the unit at intensities above those which resulted in a heart rate higher than 70% of maximal heart rate on placebo. There was a strong correlation (r=0.94,P<0.01) between the heart rate on placebo and the heart rate estimated by the model. Nevertheless, there was some scattering of the data around the identity line, with a standard error of the estimate for the regression line of 11 beats · min^–1. Thus, during incremental exercise, the influence of sympathetic activity on heart rate does not become progressively more important at higher exercise intensities. The application of the Rosenblueth-Simeone model shows limitations during incremental exercise, particularly at low exercise intensities.     

Variable dystrophin expression in different muscles of a Duchenne muscular dystrophy carrier

The majority of Duchenne muscular dystrophy (DMD) female carriers show dystrophin immunostaining abnormalities, although a significant proportion of clinically non-manifesting carriers are normal following this analysis. We had the opportunity to study dystrophin immunostaining in two different muscles, the vastus lateralis and the rectus abdominis of a possible DMD carrier. While the vastus showed normal dystrophin immunostaining, pathological staining was detected in her rectus abdominis. These findings seem to indicate that dystrophin expression can vary in different muscle groups of a DMD carrier. The implications of these findings in DMD carrier detection and possible dystrophin function are discussed.     

Subcutaneous phaeohyphomycosis caused by Cladophialophora bantiana

Primary subcutaneous phaeohyphomycosis can rarely be caused by Cladophialophora bantiana, and we present the histologic and culture findings of such a case. A 32-year-old African American woman with systemic lupus erythematosus presented with a 2-year history of multiple, recurrent, tender, and ulcerated skin nodules with purulent drainage on her upper back. Histologic sections of the excision demonstrated features of phaeohyphomycosis. Culture findings were characteristic of C bantiana. Of interest, at age 10 she had sustained traumatic implantation of wood splinters into this area during a tornado, yet clinical symptoms of a subcutaneous infection did not manifest until she developed lupus erythematosus at age 27. Our case highlights the role of trauma and immunosuppression in the pathogenesis of subcutaneous phaeohyphomycosis.     

A proposed autacoid mechanism controlling mastocyte behaviour

Evidence is provided here supporting the existence of a novel autacoid mechanism negatively modulating mast cell behaviour in response to noxious stimuliin vivo; hence, the denomination “autacoid local inflammation antagonism” (ALIA). In particular, as lipid amides of theN-acylethanolamine type have been reported to accumulate in tissues in degenerative inflammatory conditions, we examined whether theseN-acylated lipids could exert regulatory effects on mast cell activationin vivo. The results reported show that both long- and short-chainN-acylethanolamines, when systemically administered, are effective in reducing mast cell degranulation induced by local injection of substance P in the earpinna of developing rats. These and other data suggest that the endogenous production ofN-acylethanolamines may constitute a local autocrine/paracrine response for the negative feedback control of mast cell responses to various activating signals. Such a process may be of physio-pathological relevance in the regulation of functional neuroimmune-mast cell interactions.

     

Stratification based on language-related endophenotypes in autism: attempt to replicate reported linkage.

The identification of autism susceptibility genes has been hampered by phenotypic heterogeneity of autism, among other factors. However, the use of endophenotypes has shown preliminary success in reducing heterogeneity and identifying potential autism-related susceptibility regions. To further explore the utility of using language-related endophenotypes, we performed linkage analysis on multiplex autism families stratified according to delayed expressive speech and also assessed the extent to which parental phenotype information would aid in identifying regions of linkage. A whole genome scan using a multipoint non-parametric linkage approach was performed in 133 families, stratifying the sample by phrase speech delay and word delay (WD). None of the regions reached suggested genome-wide or replication significance thresholds. However, several loci on chromosomes 1, 2, 4, 6, 7, 8, 9, 10, 12, 15, and 19 yielded nominally higher linkage signals in the delayed groups. The results did not support reported linkage findings for loci on chromosomes 7 or 13 that were a result of stratification based on the language delay endophenotype. In addition, inclusion of information on parental history of language delay did not appreciably affect the linkage results. The nominal increase in NPL scores across several regions using language delay endophenotypes for stratification suggests that this strategy may be useful in attenuating heterogeneity. However, the inconsistencies in regions identified across studies highlight the importance of increasing sample sizes to provide adequate power to test replications in independent samples.