Effect of prolonged moderate and severe energy restriction and refeeding on plasma leptin concentrations in obese women.

BACKGROUND: Plasma leptin in humans is subject to both long- and short-term regulation; it correlates with indexes of body fat that can only change slowly. However, short-term fasting causes large and rapid decreases. OBJECTIVE: We tested the interactions between energy intake and fat loss on plasma leptin during prolonged moderate and severe energy restriction, with a view to understanding mechanisms of control. DESIGN: Postabsorptive leptin was measured with an enzyme-linked immunosorbent assay specific for the human peptide in 21 obese women aged 41 +/- 3 y (weight: 102 +/- 4 kg; 48 +/- 1% body fat) after 1 wk of a weight-maintaining diet and then weekly for 4 wk during a total fast (group 1); a 1.9-MJ/d all-protein, very-low-energy diet (VLED) (group 2); or a low-energy, balanced-deficit diet (BDD) providing 50% of maintenance energy (group 3). In groups 1 and 2, leptin was also measured after 1 wk of refeeding with a diet equivalent to the BDD. RESULTS: Mean leptin decreased markedly by up to 66% (P < 0.001) at week 1 of energy restriction and then gradually thereafter. The change in leptin per kilogram fat mass correlated with that in glucose concentrations [r = 0.538 (P = 0.012) at week 1 and r = 0.447 (P = 0.042) at week 4] but not with that in fat mass. During refeeding postfasting, leptin increased (P = 0.008), despite an ongoing loss of fat mass and correlated positively with changes in resting energy expenditure. At times with comparable cumulative energy restriction and fat loss between diets, the percentage change in leptin paralleled that in glucose. CONCLUSIONS: In obesity, changes in energy intake over days to weeks are a primary modulator of plasma leptin concentrations that are related to the change in glycemia and are able to override the regulatory influence of fat mass.     

Nutritional status and dietary habits of Indian children from Alto Xingu (Central Brazil) according to age

OBJECTIVE: To evaluate the nutritional status and dietary habits of children of the Alto Xingu, Central Brazil, according to age. SUBJECTS: 172 Indian children (<10 years of age) of Alto Xingu tribes. METHODS: Date of birth, sex, weight, height (NCHS reference) and questionnaire of dietary habits at the time of field work. RESULTS: Of the 103 children less than 5 years of age, 34% presented protein-energy malnutrition (PEM), according to Gomez's criteria, of which only 2% with grade II malnutrition and no child presented severe PEM. In relation to the Z scores for the 172 children studied, it was observed that those younger than 1 year (n=25) presented weight for age (median, M=+0.43) and weight for height (M=+1.33) greater (p<0.05) than the children with ages between 12 and 60 months (n=78) (weight for age, M=-0.54; weight for height, M=+0.29) and between 60 and 120 months (n=69) (weight for age, M=-0.78; weight for height, M=+0.27). The height for age Z scores for the population studied showed a shift to the left in relation to the reference population in the three age groups (<12 months, M=-0.95; 12 to 60 months, M=-1.22 and 60 to 120 months, M=-1.40). The mothers nursed, without exception, to the age of 24 months, and the frequency of breastfeeding decreased progressively to age 42 months. The introduction of solid foods started at the age of 6 months and after the 10th month all the children ate "beiju" (flat bread), fruit and fish. CONCLUSION: The nutritional status of Alto Xingu Indian children, in 1992, is adequate and similar to that previously observed between 1974 and 1980.     

A pharmacological study of the angiotensin receptor and tachyphylaxis in smooth muscle.

The interaction of angiotensin with its receptor has been studied on the basis of the tachyphylaxis shown by the rat uterus towards angiotensin II when pH and Ca2+ concentration are below physiological levels. 14C-Angiotensin binding and 45Ca2+-uptake investigations suggest tachyphylaxis to be due to increased binding at low pH and Ca2+ concentration. Studies with alkylating (affinity labeled) angiotensin derivatives containing the N-mustard chlorambucil suggest a "Charnière type" inhibition at the Ca-binding site of receptor and an irreversible inhibition at an anionic site. Angiotensin inhibitors containing chlorambucil do not alkylate tissue but are competitive inhibitors suggesting that the aromatic side chain in angiotensin may induce conformational changes in the receptor. The results obtained lead to a logical model for the angiotensin receptor allowing for normal activation by the hormone as well as for production of tachyphylaxis.     

Modified retrograde intubation in a patient with difficult airway

We report a modified technique of retrograde endotracheal intubation in a patient with limited motility at the atlanto-occipital joint, temporomandibular joint, and cervical spine, presenting for closure of a large oronasal fistula. Despite more recent advances in intubation techniques and technology, retrograde intubation still deserves a place in the anesthetist's armamentarium for the management of the difficult airway.     

Effects of latex membrane on guided regeneration of long bones

Abstract

Natural latex extracted from Hevea brasiliensis is one of the materials pointed out as potential tissue regenerators. The use of latex-based membranes in bone regeneration might be an alternative to stimulate bone formation. The aim of this study was to evaluate the effects of latex membranes in guided bone regeneration of defects produced in long bones of rats. Sixty rats were equally divided into latex and control groups, and each group was subdivided into two subgroups according to treatment duration of 1 and 4 weeks. Bone defects with 2.5?mm in diameter were surgically made in the left tibia. In the animals of the latex group, a latex membrane was placed over the bone defect. The samples underwent quantitative histological analysis of bone formation and collagen matrix, immunohistochemical analysis of osteogenic protein markers, assessment of bone mechanical properties and bone densitometry, and radiological assessment. The osteocalcin immunostaining data were submitted to the generalized linear model test with two independent factors. For the other data, the multivariate ANOVA with two independent factors was performed. The use of the latex membrane significantly improved (p?<?0.005) the volume of newly formed bone, collagen type I matrix, expression of osteopontin, and bone stiffness, both in the early and late stages of regeneration. In conclusion, the latex membrane was able to promote bone regeneration in long bones.     

Pneumonia‐induced sepsis in mice: temporal study of inflammatory and cardiovascular parameters

The aim of the present work is to provide a better comprehension of the pneumonia‐induced sepsis model through temporal evaluation of several parameters, and thus identify the main factors that determine mortality in this model. Klebsiella pneumoniae was inoculated intratracheally in anesthetized Swiss male mice. Inflammatory and cardiovascular parameters were evaluated 6, 24 and 48 h after the insult. The results show that severity of infection and the mortality correlated with the amount of bacteria. Six, 24 and 48 h after inoculation, animals presented pathological changes in lungs, increase in cell number in the bronchoalveolar lavage, leukopenia, increase in TNF‐α and IL‐1β levels, hypotension and hyporesponsiveness to vasoconstrictors, the two latter characteristics of severe sepsis and septic shock. Significant numbers of bacteria in spleen and heart homogenates indicated infection spreading. Interestingly, NOS‐2 expression appeared late after bacteria inoculation, whereas levels of NOS‐1 and NOS‐3 were unchanged. The high NOS‐2 expression coincided with an exacerbated NO production in the infection focus and in plasma, as judging by nitrate + nitrite levels. This study shows that K. pneumoniae inoculation induces a systemic inflammatory response and cardiovascular alterations, which endures at least until 48 h. K. pneumoniae‐induced lung infection is a clinically relevant animal model of sepsis and a better understanding of this model may help to increase the knowledge about sepsis pathophysiology.     

Assessment of quality of life after endoscopic sinus surgery for chronic rhinosinusitis

Chronic rhinosinusitis is a disease of undefined etiology that significantly impacts the quality of life of its patients. Various studies carried out in countries other than Brazil have shown endoscopic sinus surgery as an effective means of treating this condition.ObjectiveThis study aims to analyze, with the aid of SNOT-20, the association between endoscopic sinus surgery and disease-specific quality of life of Brazilian patients treated for chronic rhinosinusitis accompanied or not by nasal polyps.Materials and MethodsThis prospective study enrolled patients submitted to endoscopic sinus surgery after drug therapy failed to improve their symptoms. They were assessed based on questionnaire SNOT-20p before and 12 months after surgery. Improvement on total scores and on the five items deemed more important by each patient were assessed. The study also looked into the correlation between preoperative scores and postoperative improvement and if there were any gender-related improvement differences.ResultsForty-three patients aged 44 (19), md (IQR), 65% of whom (26/43) were males. Statistically significant improvement was seen on SNOT-20 and SNOT-20(5+) and a correlation was established between preoperative scores and postoperative improved scores (p<0.001). No gender-related differences were observed in quality of life.ConclusionEndoscopic sinus surgery in patients with chronic rhinosinusitis is associated with statistically significant improvements in disease-specific quality of life.     

The use of ablative lasers in the treatment of facial melasma

Melasma represents a pigmentary disorder that is difficult to treat. This study aims to broadly review the use of ablative lasers (Er:YAG and CO2) in the treatment of melasma, presenting the level of evidence of studies published to date. A total of 75 patients were enrolled in four case series studies (n=39), one controlled clinical trial (n=6) and one randomized controlled clinical trial (n=30). Studies on the Er:YAG laser showed better results with the use of short square-shaped pulses, which determined low rates of post-inflammatory hyperpigmentation and long-lasting maintenance of results. Likewise, studies on the CO2 laser proved the benefits of short pulse duration along with low-density energy. Post-treatment maintenance with the use of antipigmenting creams was necessary and effective to sustain long-term results. Ablative lasers may represent another useful and effective tool against melasma. Postinflammatory hyperpigmentation and difficulty in sustaining long-term results still represent the main limitations to a broader use of ablative lasers. Based on actual evidence, the use of this technology should be restricted to patients with recalcitrant disease. Further studies will help establish optimal laser parameters and treatment regimens.