Exercise training at MLSS decreases weight gain and increases aerobic capacity in obese Zucker rats

This study aimed to identify the aerobic capacity enhancement and subsequent body weight (BW) status of obese Zucker rats (OZRs) after 4 weeks of treadmill running exercise at the maximal lactate steady state (MLSS). In addition to obese Zucker rats (OZRs), lean Wistar Kyoto rats (WKYs) were used, and both species were divided into control and exercise groups as follows: obese exercise (OZR-EX, n=5), obese control (OZR-CON, n=5), lean exercise (WKY-EX, n=5) and lean control (WKY-CON, n=5). The OZR and WKY exercise groups trained 5 days per week at 12.5 m.min-1 and 20 m.min-1, respectively. After 4 weeks of training, MLSS was ascertained to evaluate the animals' aerobic capacity using 3 different velocities (12.5, 15 and 17.5 m.min-1 for OZRs and 25, 30 and 35 m.min-1 for WKYs). The MLSS of OZR-EX was identified at the velocity of 15 m.min-1, representing a 20% increase in aerobic capacity after the exercise program. The MLSS of WKY-EX was identified at 30 m.min-1 with a 50% increase of in aerobic capacity. Obese animals that exercised showed reduced weight gain compared to the non-exercise obese control group (p <0.05). Our results thus show that exercise training at MLSS intensity increased the aerobic capacity in both obese and non-obese animals and also reduced BW gain.

Evaluation of the potential of squash pumpkin by-products (seeds and shell) as sources of antioxidant and bioactive compounds

The transformation of byproducts and wastes generated by agro-food companies is of high importance since only a small portion of plant material is utilized directly for human consumption. Squash pumpkin is greatly used in Portugal and as by-products of its processing are generated tons of shell and seeds. In this study we aim to evaluate the potential of these wastes as sources of beneficial and bioactive compounds (antioxidants and antimicrobials), studying the effect of different extraction solvents and drying methods. The samples (fresh and cooked) were freeze-dried and oven-dried followed by extraction with different solvents that revealed the following decreasing order of efficiency: 70 % ethanol, 70 % methanol, 70 % acetone, ultra-pure water and 100 % dichloromethane. The oven-dried samples showed higher values of antioxidant activity and phenolic content, with exception of the values of phenolics for the seeds material. The shell samples presented higher values (1.47 - 70.96 % inhibition) of antioxidant activity and total phenolic content (2.00 - 10.69 mg GAE/g DW). A positive correlation was found between these two parameters on the shell samples, however the squash seeds revealed a negative correlation between the phenolic content and the antioxidant activity. The results show that these industrial agro-food residues are potentially good sources of bioactive compounds with health benefits.

Determination of the maximal lactate steady state in obese Zucker rats

This study aims to identify the maximum lactate steady state (MLSS) in obese rats in order to provide a more effective tool in the exercise training prescription for this important animal model. To make such determination, obese (Zucker, n=5) (390.0±18.8 g) and lean (Wistar, n=5) (227.3±26.2 g) rats were studied. After adaptation of animals to treadmill, the MLSS was determined by using 3 different velocities (10 m.min⁻¹, 12.5 m.min⁻¹ and 15 m.min⁻¹ for Zucker and 15 m.min⁻¹, 20 m.min⁻¹ and 25 m.min⁻¹ for Wistar). The MLSS was defined as the highest blood lactate concentration that increased up to 1 mmol.L⁻¹ during constant exercise. In obese rats, the MLSS was found in a velocity considerably lower than in lean controls (12.5 m.min⁻¹ and 20 m.min⁻¹), respectively (p<0.05). Therefore, the identification of MLSS in obese Zucker rats is an important tool for exercise prescription and evaluation in obese rat models.

Histochemistry of skin glands of Trachycephalus aff. venulosus Laurenti, 1768 (Anura, Hylidae)

The skin of the adult tree frog, Trachycephalus aff. venulosus, was investigated by light microscopy. Histochemistry was carried out using various stain techniques and showed the basic integument morphology of the skin with squamous epithelium in the epidermis and connective tissue in the dermis, subdivided into spongy and compact layers. The integument observed contains two types of gland; the mucous glands and granular glands. The mucous glands are small and located in the upper layer of the stratum spongiosum of the connective tissue and contain neutral and acid sulfated glycoproteins. The granular glands are large and form a syncytial secretory compartment within the acinus, which is surrounded by smooth muscle cells. Histochemical analyses demonstrated the presence of collagen proteins in both types of gland. An unusual finding was the different densities of the granules in the granular glands. The morphological characteristics of the integument in Trachycephalus aff. venulosus was also compared with others species of Anura.

Learning curve for laparoscopic Roux-en-Y gastric bypass with totally hand-sewn anastomosis: analysis of first 600 consecutive patients

BACKGROUND

Laparoscopic Roux-en-Y gastric bypass (LRYGB) is a challenging operation for the treatment of morbid obesity with well-demonstrated effectiveness in weight lost. There are several variations to the technique.

METHODS

From September 2000 to July 2004, 600 consecutive patients underwent surgery for morbid obesity at our institution. The surgical technique employed was LRYGB with totally hand-sewn gastrojejunal anastomosis (GJA). All patients were considered candidates for laparoscopic approach regardless of age, gender, body mass index (BMI), or previous bariatric or digestive surgery.

RESULTS

Mean BMI was 44.4 +/- 7.6 kg/m2. Thirty-two patients had undergone previous failed bariatric procedures. Conversion to an open procedure was necessary in three patients. Seventy-two patients (12%) developed early complications, including 23 (3.8%) leaks at the GJA (eight in the first 18 patients). Mortality rate was 1.1% (one death was related to GJA leakage). Early and late reoperation rates were 5.3 and 1.8%, respectively. Rate plateau of morbidity and mortality was reached after the first 18 patients when the surgical technique was fully standardized.

CONCLUSIONS

LRYGB is a technically demanding procedure for the surgical treatment of morbid obesity with significant morbidity during the learning curve. The learning curve can be soon overcome, reaching a rate plateau of complications after adequate training. Morbidly obese patients should be operated on in expert bariatric surgical laparoscopic units to obtain the best results.

Antioxidant effect of saponin: potential action of a soybean flavonoid on glucose tolerance and risk factors for atherosclerosis

At the present time, much attention is being paid to antioxidant substances because many pathological conditions are associated with oxidative stress. The purpose of the present study was to discover the potency of saponin (2-phenyl-benzopyrane), a soybean flavonoid, with respect to its hypoglycaemic and hypolipidaemic action, and the association of these effects with oxidative stress. Male Wistar rats were divided into two groups (n = 6): control group and saponin-treated group (60 mg/kg) during 30 days. Saponin had no effects on glucose tolerance. Although no changes had been observed in low-density lipoprotein-cholesterol, saponin-treated animals had increased low-density lipoprotein-cholesterol/triacylglycerol ratio and decreased triacylglycerol, very low-density lipoprotein-cholesterol and total/high-density lipoprotein-cholesterol ratio than the control group. Saponin-treated rats showed lower lipid hydroperoxide than control rats, indicating decreased potential to atherosclerosis. No alterations were observed in antioxidant enzymes, superoxide dismutase and glutathione peroxidase, while lipid hydroperoxide were decreased in saponin-treated rats. In conclusion, the beneficial effects of saponin on serum lipids were related to a direct saponin antioxidant activity.

Toxicity of dietary restriction of fat enriched diets on cardiac tissue

The present study examines the effects of caloric restriction in cardiac tissue evaluation markers of oxidative stress. High-fat dietary restrictions can have a long-term impact on cardiac health. Dietary restriction of control diet increased myocardial superoxide dismutase (SOD) and catalase activities. Dietary restriction of fatty acid-enriched diets increased myocardial lipoperoxide concentrations, while SOD activity was decreased in cardiac tissue of rats with dietary restriction of fatty acid-enriched diets. Dietary restriction of unsaturated fatty acid-enriched diet induced the highest lipoperoxide concentration and the lowest myocardial SOD activity. Dietary restriction of unsaturated fatty acid decreased myocardial glycogen, and increased the lactate dehydrogenase/citrate synthase ratio. Dietary restriction of fatty acid-enriched diets were more deleterious to cardiac tissue than normal ad lib.-fed diet. In conclusion, the effects of caloric restriction on myocardial oxidative stress is dependent on which nutrient is restricted. Dietary restriction of fatty acid-enriched diets is deleterious relative to ad lib.-fed chow diet.

Toxicity of ad lib. overfeeding: effects on cardiac tissue

The aim of the present study was to determine the effects of ad lib. overfeeding and of dietary restriction (DR) on oxidative stress in cardiac tissue. Lipoperoxide concentrations were decreased and antioxidant enzymes were increased in moderate-DR-fed rats. Severe-DR induced increased lipoperoxide concentrations. Overfeeding increased lipoperoxide levels in cardiac tissue. Total superoxide dismutase (SOD) and Cu-Zn superoxide dismutase (Cu-Zn SOD) activities were decreased in cardiac tissue at 35 days of overfeeding. As no changes in glutathione peroxidase (GSH-Px) were observed in overfed rats, while SOD and Cu-Zn SOD activities were decreased in these animals, it is assumed that superoxide anion is an important intermediate in the toxicity of ad lib. overfeeding. Overfeeding induced alterations in markers of oxidative stress in cardiac tissue.

The use of the oxidative stress responses as biomarkers in Nile tilapia (Oreochromis niloticus) exposed to in vivo cadmium contamination

Water contaminants have a high potential risk for the health of populations. Protection from toxic effects of environmental water pollutants primarily involves considering the mechanism of low level toxicity and likely biological effects in organisms who live in these polluted waters. The biomarkers assessment of oxidative stress and metabolic alterations to cadmium exposure were evaluated in Nile tilapia, Oreochromis niloticus. The fish were exposed to 0.35, 0.75, 1.5, and 3.0 mg/l concentrations of Cd2+ (CdCl2) in water for 60 days. Fish that survived cadmium exposure showed a metabolic shift and a compensatory development for maintenance of the body weight gain. We observed a decreased glycogen content and decreased glucose uptake in white muscle. Lactate dehydrogenase (LDH) and creatine phosphokinase (CK) activities were also decreased, indicating that the glycolytic capacity was decreased in this tissue. No alterations were observed in total protein content in white muscle due to cadmium exposure suggesting a metabolic shift of carbohydrate metabolism to maintenance of the muscle protein reserve. There was an increase in glucose uptake, CK increased activity, and a clear increase of LDH activity in red muscle of fish with cadmium exposure. Since no alterations were observed in lipoperoxide concentration, while antioxidant enzymes glutathione peroxidase (GSH-Px) and superoxide dismutase (SOD) were changed in the liver and the red and white muscle of fish with cadmium exposure, we can conclude that oxygen free radicals are produced as a mediator of cadmium toxicity. Resistance development is related with increased activities of antioxidant enzymes, which were important in the protection against cadmium damage, inhibiting lipoperoxide formation.

[Human colostrum: a natural source of probiotics?]

OBJECTIVE: The aim of the present study was to obtain data on the microbiota of human colostrum, and to correlate it with a possible source of probiotics transferred from mother to infant during breastfeeding. METHODS: 70 samples of milked human colostrum were analyzed as to the presence of mesophylic, thermoduric, psychrotrophic, proteolytic, proteolytic-psychrotrophic, lipolytic microorganisms, molds and yeasts, Staphylococcus aureus, total coliforms, fecal coliforms, Group D Streptococcus species and lactic acid bacteria. RESULTS: the microbiological analyses revealed several classical groups of microorganisms: mesophylic (68.6%); thermoduric (38.6%); psychrotrophic (8.6%); proteolytic (15.7%); proteolytic-psychrotrophic (1,4%); lipolytic (4.3%); molds and yeasts (11.4%); Staphylococcus aureus (44.3%); total coliforms (7.2%); and lactic acid bacteria (37.2%), thus characterizing a diversified microbiota. Thermoduric-psychrotrophic microorganisms, fecal coliforms and Group D Streptococcus species were not identified in any of the samples. CONCLUSIONS: The results show a microbiota rich in lactic acid bacteria, which may work as probiotics if delivered to infants within the first days of life.

CD69 expression on peripheral CD4+ T cells parallels disease activity and is reduced by mycophenolate mofetil therapy in uveitis

PURPOSE

To assess the effects of mycophenolate mofetil (MMF) therapy on T helper cell activation status, using CD69 expression and cytokine profile with flow cytometry in relation to clinical activity in uveitis.

METHODS

Patients with posterior or intermediate uveitis treated with MMF (n = 10), patients with active uveitis not treated with MMF and receiving no or minimal therapy (n = 10), and healthy volunteers (n = 21) had peripheral blood lymphocyte immunofluorescence analysis for T helper cell (CD4, CD3) markers, activation status (CD69), and intracellular cytokine (interleukin [IL]-2, interferon [IFN]-gamma, and IL-4) levels. Patients were compared before and during MMF therapy in relation to T helper cell activation and clinical activity.

RESULTS

Patients with active uveitis not treated with MMF and receiving no or minimal therapy had increased frequency of CD69-positive CD4 T cells (10.5% +/- 4.6%, P = 0.0007) compared with healthy volunteers (3.3% +/- 2.7%). Of all patients receiving MMF therapy, only patients with moderate to severe uveitis activity in the pre-MMF treatment group (n = 5; 15.5% +/- 5.0%, P = 0.004) had increased frequency of CD69-positive CD4 T cells compared with healthy volunteers. During MMF therapy, a significant reduction in frequency of CD69-positive CD4 T cells occurred in patients with prior moderate to severe uveitis activity (to 8.9% +/- 3.8%, P = 0.04). Levels of CD69-positive CD4 T cells in patients who had had inactive or mildly active disease (n = 5) before and during MMF therapy were comparable with levels in healthy volunteers. No significant changes in cytokine levels were found between the patient and control groups. A significant association between changes in frequency of CD69-positive CD4 T cells and changes in visual acuity (P = 0.008) and changes in vitreal haze (binocular indirect ophthalmoscopy score; P = 0.01) was observed in MMF-treated patients with prior moderate to severe uveitis activity.

CONCLUSIONS

Reduction in uveitis activity during MMF therapy correlates with reduction in frequency of peripheral blood CD69-positive CD4 cells. The frequency of CD69-positive CD4 T cells is a measure of activity in posterior uveitis and may guide adequate immunosuppression.

[Antimicrobial resistance of coliform isolates from expressed human milk]

The dispersion of potentially pathogenic, antibiotic-resistant microorganisms via expressed human milk can be considered a risk factor. The aim of this study was to contribute to a better understanding of coliform isolates from expressed human milk and their antimicrobial resistance profiles. The sampling scheme followed a totally randomized design, using 837 samples of expressed human milk. Of these, 71 (8.48%) were identified as contaminated with total coliforms, although in none of the samples did the population exceed 1.0x10(3) MPN/ml. Most of the microorganisms isolated (91.6%) belonged to only two species, Enterobacter cloacae and Klebsiella pneumoniae, which when subjected to antibiograms, revealed that several strains showed prior resistance to some of the antimicrobials tested. Coliforms may grow in expressed human milk if it is improperly stored, depleting protection factors and reducing the milk's nutritional value.

Environmental cadium exposure and metabolic responses of the Nile tilapia, Oreochromis niloticus

The contamination of water by metal compounds is a worldwide environmental problem. This study was undertaken to evaluate the impact of short-term cadmium exposure on metabolic patterns of the freshwater fish Oreochromis niloticus. The fish were exposed to 320, 640, 1,280 and 2,560 microg/l sublethal concentrations of Cd++ (CdCl2) in water for 7 days. The specific activities of the enzymes phosphofructo kinase (PFK-E.C.2.7.1.11.), lactate dehydrogenase (LDH-E.C.1.1.1.27.) and creatine kinase (CKE.C.2.7.3.2.) were decreased in white muscle after cadmium treatments, indicating decreases in the capacity of glycolysis in this tissue. Cadmium exposure induced increased glucose concentration in white muscle of fish. On the other hand, cadmium exposure at sublethal concentrations increased phosphofructo kinase and LDH in red muscle of fish. Cadmium significantly decreased total protein concentrations in liver and white muscle regardless of tissue glycogen levels. The data suggest that cadmium acts as a stressor, leading to metabolic alterations similar to those observed in starvation.

How to prevent port-site metastases in laparoscopic colorectal surgery

Various reports concerning port-site metastasis after laparoscopic surgery for colorectal cancer have created a new concern regarding the use of this technique for the treatment of this malignancy. The real incidence is not yet known; neither are its prognostic implications. Numerous experimental studies, both in vitro and in vivo, have been published since 1994. These studies have analyzed the possible role of pneumoperitoneum and carbon dioxide (CO(2)) and pathophysiology, as well as the influence of minimally invasive techniques on tumor response and immunity. There are no definitive results yet, but there is enough evidence to presume that the etiology of this new complication might derive from surgical technique. We present our 8-year experience with laparoscopic surgery for colorectal cancer. We also review our technique for preventing port-site implants. At this writing, we have had no port metastasis in our series of 320 colorectal cancer cases with a mean follow-up period of 54 months. The steps we follow as a routine in all cases of laparoscopic colorectal cancer are (a) fixation of trocars to the abdominal wall, (b) avoidance of touching the tumor, (c) high vascular ligation, (d) intraoperative colonoscopy and intraluminal irrigation with 5% iodine povidone, (e) specimen isolation before extraction from the abdominal cavity, and (f) intraperitoneal and trocar-site irrigation with a tumoricide solution.

Effect of the source of dietary fat on postweaning lipogenesis in lean and fat pigs

Twenty-four male piglets weaned after 21 days, 12 of the Large White lean breed (LW) and 12 of the Alentejano fat breed (AL), have been used to compare the effects of genotype and source of dietary fat on the activities of enzymes involved in lipogenesis and on the composition of selected fatty tissues. During 4 weeks the piglets were fed isoenergetic and isonitrogenous experimental diets, containing 5 % of either olive oil or tallow. In AL piglets the acetylcoenzyme A carboxylase activity was three- and ninefold higher, the malic enzyme activity six- and fivefold, and the glucose-6-phosphate dehydrogenase activity was four- and fivefold higher in the dorsal subcutaneous and in the perirenal fat, respectively, than in LW piglets. In general, fatty tissues of the AL piglets contained a higher proportion of saturated fatty acids. Olive oil induced a significant increase in the activities of malic enzyme and glucose-6-phosphate dehydrogenase in both tissues, but only slightly increased the acetylcoenzyme A carboxylase activity in perirenal fatty tissues (p < 0.05). The fatty acid profile of the subcutaneous and of the perirenal fat was strongly affected by the composition of dietary fat. These observations showed that the source of dietary fat influenced markedly lipid metabolism and body composition since a very early age.

Methicillin-resistant Staphylococcus aureus in human milk

We collected and analyzed 500 samples of human milk, from five Brazilian cities (100 from each) to detect methicillin-resistant strains of Staphylococcus aureus (MRSA) producing enterotoxins. We found 57 strains of MRSA, and the mecA gene, responsible for resistance, was detected in all of them using a specific molecular probe. We examined 40 strains for the presence of four enterotoxins, after selecting a subset that included all strains from each region, except for the largest sample, from which 10 were randomly selected. Among these two presented enterotoxin B, and growth in human colostrum and trypicase soy broth. After 5 h of incubation at 37 degrees C, population sizes were already higher than 9.4 x 10(5) UFC/ml and enterotoxin was released into culture medium and colostrum. Our results stress the importance of hygiene, sanitary measures, and appropriate preservation conditions to avoid the proliferation of S. aureus in human milk.

Relationship between Chagas' disease immunoreactivity in pericardial fluid and survival of children

Pericardial fluid (PF) obtained at autopsy has been used for the study of fluid pericardium proteins in noninfectious and infectious diseases such as Chagas' disease. The aim of the present study was to determine the immunoreactivity to Chagas' disease in PF obtained at autopsy from children in an endemic area. A total of 251 autopsy records were surveyed from the files of the Medical School of Uberaba, Brazil, of children ranging in age from stillborn to 14 yr who had died between 1968 and 1992. The reactions for Chagas' disease (immunofluorescence, complement fixation, and hemagglutination) applied to PF were recorded. Thirty-four children (13.5%) showed positive reactions to Chagas' disease. The frequency of immunoreactivity was significantly related to age-group distribution (chi 2 = 13.4; P < 0.005). Children with negative PF tests who had died between 1 and 60 days of age presented a median survival time of 13 days; positive children presented a median survival time of 4 days (Z = 2.1; P = 0.02). These data indicate that the prevalence of Chagas' disease is high among pregnant women in southern Brazil. In addition, they also suggest that "antitrypanosome antibodies" detected in PF may be 1 of the indicators of age of infant death and may possibly play a role in the course of the disease in children born from mothers with Chagas' disease.