Striae distensae in darker skin types: the influence of melanocyte mechanobiology

Introduction Striae distensae in White people are commonly described as being reddish at first and turning white in time. This dual perception has been challenged. Indeed, the color difference between striae distensae and their surrounding skin varies on a wide range in part depending upon typology. Aim To study striae nigrae that are found only in subjects of darker complexion. Materials and methods In the present study conducted in 44 darker skin adults, dermoscopy was combined to reflectance colorimetry. Results Striae nigrae exhibited hypermelanosis of the epidermal rete ridges crossing transversally the lesions in a laddering pattern. By contrast, striae albae showed only faint melanotic networks. Conclusions As striae distensae are in part under the influence of skin stretching, their colors are likely to be controlled by some mechanobiological process activating or inhibiting melanogenesis in people of darker complexion. No argument involving an inflammatory mechanism is supported by the present observations.     

Noradrenaline use is not associated with extubation failure in septic patients

Standard clinical practice recommends minimal doses of vasoactive drugs during weaning of patients from mechanical ventilation. However there are currently no clinical data to inform clinicians about whether the use of noradrenaline during weaning predisposes to weaning failure. The objective of this study was to evaluate whether the necessity of the vasopressor noradrenaline in mechanically ventilated patients recovering from septic shock changed the extubation outcome. A total of 656 patients recovering from septic shock on mechanical ventilation were selected from intensive care units in two university hospitals. Patients receiving noradrenaline at the time of weaning and case-controls not taking noradrenaline were matched for age, gender, haemodynamic and ventilatory parameters, aetiology of respiratory failure and APACHE II score. One hundred and forty-five patients who successfully tolerated a spontaneous breathing trial were extubated while on noradrenaline therapy and the reintubation rate was measured. In the noradrenaline group, the mean dose of noradrenaline during initial shock treatment was 0.52+/-0.29 microg/kg/min and 0.12+/-0.10 microg/kg/min during weaning. The reintubation rate was 12/63 (19%) in the noradrenaline group and 15/82 (18.3%) in the control group (P=1.00). Intensive care unit mortality was also similar in both groups (10/63, 15.9%) for noradrenaline patients and (11/82, 13.4%) for control patients (P=0.81). Arterial blood gases and ventilatory and haemodynamic parameters were similar in all patients regardless of weaning success. We did not find that the use of noradrenaline at the time of weaning was associated with extubation failure. Low doses of noradrenaline may not preclude weaning from mechanical ventilation.     

Zootherapeutic practices among fishing communities in North and Northeast Brazil: a comparison

This paper compares the medicinal uses of animals in fishing communities located in the North and Northeastern regions of Brazil. Data were obtained through field surveys conducted in the Northern state of Pará and in the NE states of Paraíba, Piauí and Maranhão. We interviewed 137 people (67 men and 70 women), who provided information on animal species used as remedies, body parts used to prepare the remedies, and illnesses to which the remedies were prescribed. Comparisons were made using cluster analysis. Interviewees quoted 138 animal taxa, 11 of which are listed in the Brazilian list of threatened species. Animals were used to treat 100 illnesses. Results suggest that similarities in the repertoire of medicinal resources chosen by the surveyed communities reflects both a geographic/cultural continuum and the local accessability/availability of the resources.     

Biochemistry of the induction and prevention of lipoperoxidative damage in human spermatozoa

Lipid peroxidation occurs in human sperm cells with damage to the cell plasma membrane, leading to loss of cytosolic components and hence to cell 'death'. The peroxidation may be induced at high rates in the presence of Fe2+ and ascorbate. It occurs at slower rates under physiological conditions as spontaneous lipid peroxidation, which has the following characteristics. The rate is constant over the time required for complete loss of motility in the cells of the sperm sample; one can thus use the time to complete loss of motility (TLM) as a ready measure of the rate. Loss of motility occurs at a characteristic extent of lipid peroxidation, assayed in terms of production of the peroxidative breakdown product, malonaldehyde (MA), that is independent of peroxidation rate. For human sperm, this extent corresponds to 0.1 nmol MA/10(8) cells. Human spermatozoa possess the anti-lipoperoxidative defence enzymes, superoxide dismutase (SOD) and glutathione peroxidase plus glutathione reductase (GPX/GRD). The SOD activity is highly variable between human sperm samples while the activities of GPX and GRD are rather more constant. The rates of production of superoxide anion, O2-, and hydrogen peroxide, H2O2, from human spermatozoa are variable, but their sum calculated in O2- equivalents as O2- + 2H2O2 is quite constant. The variability arises from the variability in SOD activity: all H2O2 produced is from O2- due to the action of SOD. The essential role of SOD as defence enzyme is inferred from the observation that TLM of a given sperm sample is directly proportional to the SOD activity of that sample. The essential role of GPX/GRD is inferred from the observation that inhibition of GPX, either with mercaptosuccinate or with complete oxidation of intracellular reduced glutathione, results in a 20-fold increase in peroxidation rate. The capacity of the GPX/GRD system appears to be limited by the glucose-6-phosphate dehydrogenase-catalysed rate of production of NADPH, the required reductive substrate for GRD. Human spermatozoa appear to have enough anti-lipoperoxidative defensive capacity for lifetimes long enough for fertilization but still short enough for ready removal from the female reproductive tract in good time. Too low a defence capacity could lead to male infertility.      

Outpatient surgery for anorectal diseases: the experience of the Clinics Hospital of the Medical School, Botucatu, SP, Brazil, in 437 cases

BACKGROUND: The number of outpatient surgical procedures performed in hospitals, as well as in private clinics, increases daily. In some countries, such as France, outpatient operations outnumber inpatient operations. OBJECTIVE: To evaluate results obtained at the Surgical Outpatient Clinic of the Clinics Hospital of the Medical School, Botucatu, SP, Brazil. PATIENTS AND METHODS: A retrospective study of 437 clinical cases of anorectal anomalies, analyzing the variables age bracket, gender, pathology, and postoperative complications. RESULTS: We observed predominance of patients younger than 45 (62.8%) and of females (56%). The most common ailment was hemorrhoids (45.1%) and the most frequent postoperative complications were pain (9.8%) and bleeding (7.3%). CONCLUSIONS: Our results demonstrate that it is possible to perform various simple procedures related to the treatment of anorectal abnormalities at the outpatient level and therefore at a lower cost. The number of postoperative complications was no higher than that resulting from inpatient surgery.