A nomogram for assessment of breathing patterns during treadmill exercise

Objective: To assess the breathing patterns of trained athletes under different conditions. The hypothesis is that the breathing pattern during a progressive treadmill exercise is independent of the protocol, at least in healthy people, and can be assessed using a nomogram.

Methods: A total of 43 male and 21 female athletes from different sports were studied. They performed one of two different protocols (steps or ramp) on a treadmill. The two protocols started at the same speed and had the same rate of increase in work. During the test, the expired air was analysed for CO₂ and O₂. Ventilation (VE) was continuously recorded, and tidal volume (Vt) and breathing frequency (BF) at the same intensity were analysed for both protocols, as well as Vt/T_i and T_i/T_tot.

Results: No significant differences were observed in Vt and BF between the two protocols in either the men or women at any level (confidence intervals up to 0.958 in all the groups). T_i/T_tot remained constant, and all increases in VE were strongly related to the respective increases in Vt/T_i. Plots of data for men and women showed a curvilinear relation between Vt and BF which could be fitted with an exponential function with a strong correlation (R² = 0.98 for men and 0.97 for women).

Conclusions: Graphic expression of Vt v BF is a useful nomogram for the routine assessment of ventilatory response during exercise in healthy trained subjects.

     

Arteriovenous malformations of the vein of Galen

Vein of Galen arteriovenous malformations encompass a diverse group of vascular anomalies that share a common feature: dilatation of the vein of Galen. Although clinical presentations are highly variable, depending on age of presentation, signs and symptoms overlap between age groups. The association of heart failure and cranial bruit constitutes the most striking clinical presentation in neonates. However, less severe and fulminant modes of presentation are frequent in older infants, children, and adults. Treatment approaches consist of symptomatic treatment of heart failure on the one hand and of surgery or endovascular treatment on the other. The results of the latter have improved in recent years, opening up a broad spectrum of new possibilities. We present the case of an asymptomatic 15-day-old neonate who presented an arteriovenous malformation of the vein of Galen and who was treated with endovascular occlusion of the arterial afferents. An excellent result was obtained with no evidence of neurological abnormalities.     

Recurrent polychondritis: apropos of a case

We present a case of relapsing polychondritis which presented as hypoacusis and showed several peculiarities. The initial diagnosis was serous otitis. After a more careful study we found certain details which made us suspect a relapsing polychondritis. The diagnosis was confirmed by a biopsy of the nasal cartilage and a detailed systemic study was performed. As distinctive characteristics we found a mixed hypoacusis, in which the sensorineural component was partially recovered following corticoid treatment.     

Removal of bowel aerobic gram-negative bacteria is more effective than immunosuppression with cyclophosphamide and steroids to decrease natural alpha-galactosyl IgG antibodies

Abstract: Natural α-Galactosyl (Gal) antibodies play an important role in the rejection of pig xenografts by humans and Old World monkeys. In this study we investigate the efficacy of two different strategies to reduce the serum level of natural anti-Gal antibodies. On the one hand, removal of aerobic gram-negative bacteria from the intestinal flora, because anti-Gal antibodies appear to be produced as a result of the continuous sensitization by these microorganisms. On the other hand, we studied the effect on these antibodies of an immunosuppressive regimen of cyclophosphamide and steroids. Ten baboons were treated for three months with norfloxacin (Nor Group; n = 6) or cyclophosphamide and steroids (CyP Group; n = 4). A further four baboons did not receive any treatment (Control Group). Aerobic gram-negative bacteria became negative in stools of the Nor Group after two weeks of treatment, and remained undetectable until week 7. Thereafter, a gradual increase on the fecal concentration of aerobic gram-negative bacteria was observed despite the norfloxacin treatment. The mean anti-Gal IgG in the Nor Group gradually declined from week 4 to 9 to a mean of 62.7 ± 18% of the baseline level, and during this period were significantly lower than in the CyP ( P  < 0.02) and the Control ( P  < 0.05) groups. No differences were observed between the three groups during the 16 weeks of follow-up in serum levels of anti-Gal IgM, hemolytic anti-pig antibodies, total IgG, IgM and IgA. In conclusion, removal of normal aerobic gram-negative bacteria from the intestinal flora is more effective than immunosuppression with CyP and steroids in reducing the level of natural anti-Gal antibodies, although there is no discernible effect on IgM antibodies.     

Epidemiologic aspects of American visceral leishmaniasis in an endemic focus in Eastern Venezuela

An endemic focus of American visceral leishmaniasis (AVL) in eastern Venezuela has been evaluated in terms of patients (n = 48), immunologic reactivity to Leishmania in household contacts (n = 187) and neighborhood controls (n = 170), detection of Leishmania (L. donovani complex) in dogs and wild animals by the polymerase chain reaction (PCR) and characteristics of the sandfly population. The male:female ratio of patients was 1.18:1; 89.6% were < or =12 years old. Serologic reactivity was significantly higher in household contacts than in controls (P = 0.0008), as was the size of leishmanin reactions in contacts < or =10 years of age (P = 0.0141). Leishmania donovani complex-specific PCRs were positive in dogs, an opossum (Didelphis marsupialis), and a black rat (Rattus rattus). Lutzomyia longipalpis and Lu. evansi, both implicated in the transmission of AVL, were identified among the 386 sand flies examined. These observations provide the bases for an active control program as well as further studies of reservoirs and vector-host relationships in this area.