Heme orientation affects holo-myoglobin folding and unfolding kinetics11Dedicated to Professor Bo Malmström who died February 9, 2000.

AbstractNative myoglobin (Mb) consists of two populations which differ in the orientation of the heme by 180° rotation (as verified by nuclear magnetic resonance) but have identical absorption spectra and equilibrium–thermodynamic stability. Here, we report that these two fractions of native oxidized Mb (from horse) both unfold and refold (chemical denaturant, pH 7, 20°C) in two parallel kinetic reactions with rate constants differing 10-fold. In accord, the oxidized heme remains coordinated to unfolded horse Mb in up to 4 M guanidine hydrochloride (pH 7, 20°C)

A influência do sexo e da idade na prevalência de bolsas periodontais The influence of gender and age on the prevalence of periodontal pockets

Este trabalho teve como objetivo avaliar a influência dos fatores de risco na prevalência de bolsas periodontais em pacientes atendidos na clínica do terceiro e quarto anos da Faculdade de Odontologia de Piracicaba - Unicamp. Foram avaliados 100 pacientes através do levantamento dos dados contidos nas fichas clínico-anamnésicas, sendo consideradas bolsas de profundidade: 3 mm, 5 mm, 7 mm e 10 mm, de acordo com o sistema diagnóstico WS (SALLUM; SALLUM27, 1996). Os resultados foram comparados entre as profundidades de sondagem e as variáveis idade, sexo, bem como sua distribuição por sextantes. Observou-se maior prevalência de bolsas periodontais no sexo masculino, bem como maior profundidade de sondagem em pacientes acima de 31 anos. A distribuição de bolsas periodontais entre os sextantes foi homogênea.<br>The aim of this study was to evaluate the influence of risk factors on the prevalence of periodontal pockets in patients attending the clinic of the School of Dentistry of Piracicaba - Unicamp. The sample consisted of 100 patients attended by the students from the third and fourth years of undergraduation. The data were taken from anamneses and clinical - periodontal records. Probing depths were considered to be 3, 5, 7 and 10 mm, according to the WS diagnosis system (SALLUM, 1996). The results were compared regarding pockets depths and the risk factors age and gender. Also, the distribution of pockets among the sextants was observed. This study indicated a major prevalence of periodontal pockets in men and an increase in probing depth in patients older than 31 years. The distribution of pockets among the sextants was relatively uniform in all studied groups

Noninvasive investigation of autonomic activity after carotid stenting or carotid endarterectomy

ObjectiveCarotid artery stenting (CAS) has been introduced as an alternative to carotid endarterectomy (CEA) for the treatment of carotid artery stenosis. Both techniques seem to be associated with postoperative hemodynamic lability. Both may induce baroreceptor dysfunction, possibly leading to transient impairment of cardiovascular autonomic activity and resulting in hemodynamic instability. This instability might contribute to postoperative morbidity. To elucidate these phenomena, we studied the cardiac baroreflex and autonomic cardiovascular control after CAS and CEA.MethodIn 20 patients scheduled for CAS (n = 10) or CEA (n = 10), intra-arterial pressures and electrocardiograms were recorded during 10 minutes before and 8 and 24 hours after the procedure. Spontaneous cardiac baroreflex sensitivity was assessed using the sequence method and cross-spectral analysis. In addition, cardiovascular autonomic activity was investigated using spectral analysis of heart rate variability and systolic arterial pressure variability.ResultsAfter CAS, we demonstrated an increase of the spontaneous baroreflex sensitivity median (interquartile range) from 5.6 (5.1 to 6.2) ms/mm Hg before the procedure to 8.8 (6.8 to 10.5) ms/mm Hg and 7.7 (3.9 to 8.6) ms/mm Hg (P < .001), 8 and 24 hours after the procedure. This was consistent with the increase of the high frequency component of heart rate variability reflecting cardiac parasympathetic activity and a decrease of the low frequency of systolic arterial pressure variability reflecting sympathetic vascular activity. The postoperative period was also associated with decreased systolic arterial pressure from 173 (162 to 190) mm Hg at baseline to 122 (109 to 143) mm Hg and 136 (121 to 143) mm Hg at 8 and 24 hours after CAS (P < .001). No changes in baroreflex sensitivity or in autonomic activity were observed after CEA.ConclusionsThese preliminary data suggest that CAS is associated with parasympathetic predominance postoperatively and may probably explain the lower systolic arterial pressure observed after CAS