Weight of evidence

Evidence-based Medicine (EBM) has become a major source of medical knowledge. It handles complexities of virtually every method or technique used in research. The knowledge on how the EBM researcher retrieves information, judges for relevance and analyzes derived data is invaluable for the skillful reader of medical scientific reports.

Correlation between placental thickness in the second and third trimester and fetal weight

PURPOSE: To investigate relationship between placental thickness during the second and third trimesters and placental and birth weights. METHODS: From January 2011 to June 2012, a total of 250 singleton pregnant women presented at our antenatal clinic were enrolled in this prospective study. All recruited women were assessed at the 1st trimester screening for baseline demographic and obstetric data. The placental thickness was measured trans-abdominally by placing the ultrasound transducer perpendicularly to the plane of the placenta, in the area of the cord insertion at second and third trimester. Pearson's correlation analysis was used to establish the degree of relationship between placental thickness and birth and placental weights. RESULTS: Of 250 recruited participants, 205 women were able to complete the study. The mean age of cases was 26.4±5.1. Values of mean birth and placental weights were 305.56±657.0 and 551.7±104.8 grams respectively. Ultrasonographic measures of placental thickness in second and third trimester and changes between them were 21.68±4.52, 36.26±6.46 and 14.67±5.67 mm respectively. There was a significant positive correlation between placental thickness and birth weight in the second and third trimesters (r=0.15, p=0.03; r=0.14, p=0.04 correspondingly). CONCLUSION: According to our study, birth weight has a positive relation with both second and third trimester placental thickness; however, placental thickness change could not predict low birth weight.

Factors associated with postpartum weight retention in a Brazilian cohort

PURPOSE: To identify the factors associated with weight retention after pregnancy.METHODS: A cohort study was performed with 145 women receiving maternity care at a hospital in Caxias do Sul, Rio Grande do Sul, Brazil, aged 19 to 45 years, between weeks 38 and 42 of pregnancy. The patients were evaluated at one month, three months, and six months after delivery. Student's t-test or one-way analysis of variance (ANOVA) was used to compare groups, as indicated; correlations were assessed with Pearson's and Spearman's tests, as indicated; to identify and evaluate confounders independently associated with total weight loss, a multivariate linear regression analysis was performed and statistical significance was set at p≤0.05.RESULTS: There was a significant positive association between total weight gain - and a negative association with physical exercise during pregnancy - with total weight loss. Higher parity, inter-pregnancy interval, calorie intake, pre-pregnancy body mass index (BMI), weight gain related to pre-pregnancy BMI, presence and severity of depression, and lack of exclusive breastfeeding were directly associated with lower weight loss. Among nominal variables, level of education and marital status were significantly associated with total weight loss.CONCLUSION: In the present study, lower weight retention in the postpartum period was associated with higher educational attainment and with being married. Normal or below-normal pre-pregnancy BMI, physical activity and adequate weight gain during pregnancy, lower parity, exclusive breastfeeding for a longer period, appropriate or low calorie intake, and absence of depression were also determinants of reduced weight retention.

Estimation of Fetal Weight during Labor: Still a Challenge

Objective To evaluate the accuracy of fetal weight prediction by ultrasonography labor employing a formula including the linear measurements of femur length (FL) and mid-thigh soft-tissue thickness (STT). Methods We conducted a prospective study involving singleton uncomplicated term pregnancies within 48 hours of delivery. Only pregnancies with a cephalic fetus admitted in the labor ward for elective cesarean section, induction of labor or spontaneous labor were included. We excluded all non-Caucasian women, the ones previously diagnosed with gestational diabetes and the ones with evidence of ruptured membranes. Fetal weight estimates were calculated using a previously proposed formula [estimated fetal weight = [1] 1687.47 + (54.1 x FL) + (76.68 x STT). The relationship between actual birth weight and estimated fetal weight was analyzed using Pearson's correlation. The formula's performance was assessed by calculating the signed and absolute errors. Mean weight difference and signed percentage error were calculated for birth weight divided into three subgroups: < 3000 g; 3000-4000g; and > 4000 g. Results We included for analysis 145 cases and found a significant, yet low, linear relationship between birth weight and estimated fetal weight (p < 0.001; R2 = 0.197) with an absolute mean error of 10.6%. The lowest mean percentage error (0.3%) corresponded to the subgroup with birth weight between 3000 g and 4000 g. Conclusions This study demonstrates a poor correlation between actual birth weight and the estimated fetal weight using a formula based on femur length and mid-thigh soft-tissue thickness, both linear parameters. Although avoidance of circumferential ultrasound measurements might prove to be beneficial, it is still yet to be found a fetal estimation formula that can be both accurate and simple to perform.

Effects of weight loss on the cardiac parameters of obese dogs

Obesity is one of the most frequent nutritional problems in companion animals and can lead to severe health problems in dogs and cats, such as cardiovascular diseases. This research aimed to evaluate the structural and functional cardiac changes after weight loss in obese dogs. Eighteen obese healthy dogs were assigned into three different groups, according with their initial body weight: Group I (dogs up to 15 kg), Group II (dogs weighing between 15.1 and 30 kg), and Group III (dogs weighing over 30 kg). The animals were submitted to a caloric restriction weight-loss program until they lose 15% of the body weight. The M-mode echocardiogram, electrocardiogram, and blood pressure evaluations were performed before the diet has started and after the dogs have reached the target weight. Data showed a decrease in left ventricular free wall thickness during diastole and systole in Group III, decrease in the systolic blood pressure in Group III, and also in the mean blood pressure in Group II. It was possible to conclude that the weight loss program can reverse structural cardiac changes such as left ventricle eccentric hypertrophy in dogs weighing more than 30 kg, and decrease the arterial blood pressure in obese dogs.

Ethological activities, ruminal parameters and weight gain of calves supplemented with different amounts of sodium chloride

The daily weight gain, behavioral activities (grazing, ruminating and water consumption) and the number of rumen protozoa, pH, NH3, and the osmolarity of rumen fluid was evaluated for four groups of six calves HPB/Zebu submitted to daily intake of 15, 30, 60 and 90g of NaCl during 135 days (9th Jan. to 24th May 2008).Throughout the experimental period the calves were in perfect health condition and did not show any signs suggestive of chronic sodium poisoning. There was no significant difference in average daily gain of the calves as the intake of NaCl increased. No significant behavioral changes were observed in the activities of grazing and rumination. However, there was a noticeable change in the frequency of water consumption in the calves that ingested 90g/d of NaCl; they went more often to the trough and drank more water than the group that ingested only 15g sodium chloride/d. The osmolarity of ruminal liquid was higher in the group of calves fed 90g of NaCl/d. The pH, NH3 concentration and number of rumen protozoa was within the normal range.

Influence of tail biting on weight gain, lesions and condemnations at slaughter of finishing pigs

The present study assessed the association of tail-biting lesions in finishing pigs with weight gain, occurrence of locomotion or respiratory disorders and abscesses during finishing period, and carcass condemnation at slaughter. The study was carried out on 4 different farms. For each animal with a tail biting lesion, two control pigs were selected. The total number of animals in the study was 312, with 104 of them being tail-bitten. Tail lesions were classified according to the degree of severity into four scores: score 0 -normal tail withou lesion; score 1-3 - increasing lesion severity, and score 4 - healed lesions. Overall, the occurrence of severe tail lesions (score 3) varied from 55 to 73% of tail-bitten pigs among farms. On all farms, healing of tail lesions was observed in 95% to 100% of the animals at the evaluation performed within 41-43 days after the commencement of the study. In two out of the four evaluated farms, pigs with score of 3 showed lower weight gain (P<0.05) compared with score 0 pigs. Before slaughter, the occurrence of locomotion problems and nodules/abscesses was associated (P<0.05) with the presence of tail-biting lesions. At slaughter, tail-biting lesions were associated (P<0.05) with the presence of abscesses, lung lesions (pleuritis and embolic pneumonia) or arthritis in carcasses. Carcass condemnation was associated with the presence of tail-biting lesions (P<0.05). Overall, carcass condemnation rate was 21.4%, of which animals with tail-biting lesions accounted for 66.7% of condemnations. Among the animals diagnosed with cannibalism at farm level, only two had not healed their lesions at slaughter. The fact that there were a lot of carcass condemnations, despite the fact that tail-bitten animals had no more active lesions, suggests that different situations may be observed between the field and slaughter, reinforcing the need to analyze pigs both at farm and slaughter to allow proper assessment of losses related to tail biting. Collectively, the observations of the present study show that complications associated with tail-biting found in slaughterhouses are probably underestimating field prevalence.

Parasitism level by helminths and weight gain of calves kept in organic and conventional grazing

Sustainable production is a principle in which we must meet the needs of the present without compromising the capacity of future generations. Despite the successful development of pesticides against endo and ectoparasites found in domestic ruminants, these parasites are still the major problem of the herbivore production system. The purpose of this study was to know the population of gastrintestinal parasites and their influence on weight gain of calves kept in organic and conventional grazing. Thus, organic and conventional calves were randomly selected in 2008 and 2009. The fecal egg count (FEC) indentified the following genders of helminths: Haemonchus, Trichostrongylus, Oesophagostomum, Cooperia, Strongyloides, Trichuris and oocysts of Eimeria. There was no significant difference (p>0.05) between FEC in organic and conventional animals. Calves younger than 6 months showed significant higher infection (p<0.05) than calves between 7 and 12 months of age. The weight gain observed during the study was of 327g/day and 280g/day for conventional and organic systems animals, respectively. Consequently, the combination of sustainable practices of grazing associated with the selective application of anthelmintics may be a feasible alternative for nematode control in a conventional system and in transition to an organic one.

Relationship between weight, age and hatching success and the concentration of heavy metals in nestling blue macaw (Anodorhynchus hyacinthinus Latham, 1790) in the Pantanal,Mato Grosso do Sul

Abstract: The concentration of heavy metals (Cr, Fe, Al, As, Cd, Cu, Pb, Mo, Ni, Se and Zn) was evaluated in the blood of nestling blue macaws (Anodorhynchus hyacinthinus) captured in the Pantanal, Mato Grosso do Sul (n=26) in 2012; this was based on the hypothesis that these birds exhibit levels of these heavy metals in their organism and that these interfere in hatching success, weight and age of the chicks. Blood samples were digested with nitric acid and hydrochloric acid and the quantification of metals was performed by ICP-OES (Optical Emission Spectroscopy and Inductively Coupled Plasma). Blood samples of nestlings showed concentrations of Cr (0.10μg/g) Fe (3.06μg/g) Al (3.46μg/g), Cd (0.25μg/g) Cu (0.74μg/g), Mo (0.33μg/g), Ni (0.61μg/g), Se (0.98μg/g), and Zn (2.08μg/g). The levels of heavy metals found were not associated with weight, age and hatching success of the chicks.

Correlation between high molecular weight gluten subunits composition and bread-making quality in Brazilian wheat

Bread-making quality is one of the most important targets in the genetic improvement of wheat. Although extensive analyses of quality traits such as farinography, sodium dodecyl sulfate (SDS) sedimentation, alveography, and baking are made in breeding programs, these analyses require high amounts of seeds which are obtained only in late generations. In this experiment the statistical correlations between the high molecular weight subunit of glutenin and bread-making quality measured by alveograph, farinograph and SDS sedimentation were evaluated. Seventeen wheat genotypes were grown under the same conditions, each producing about 1 kg of seeds for the evaluations. The high molecular weight (HMW) glutenin subunits were analyzed by SDS-PAGE. Statistical correlations were highly significant between HMW glutenin subunits and alveograph and SDS sedimentation. These results indicate the possibility of manipulating major genes for wheat seed quality by coupling traditional breeding with non-destructive single seed analysis. Only half seed is necessary to perform the SDS-PAGE analysis. Therefore, the other half seed can be planted to generate the progeny. Seed yield and SDS sedimentation were statistically correlated, indicating the possibility of simultaneous selection for both traits

Effects of bromocriptine on serum prolactin levels, pituitary weight and immunoreactive prolactin cells in estradiol-treated ovariectomized rats: an experimental model of estrogen-dependent hyperprolactinemia

The present study was designed to assess the effects of bromocriptine, a dopamine agonist, on pituitary wet weight, number of immunoreactive prolactin cells and serum prolactin concentrations in estradiol-treated rats. Ovariectomized Wistar rats were injected subcutaneously with sunflower oil vehicle or estradiol valerate (50 or 300 µg rat-1 week-1) for 2, 4 or 10 weeks. Bromocriptine (0.2 or 0.6 mg rat-1 day-1) was injected daily during the last 5 or 12 days of estrogen treatment. Data were compared with those obtained for intact control rats. Administration of both doses of estrogen increased serum prolactin levels. No difference in the number of prolactin cells in rats treated with 50 µg estradiol valerate was observed compared to intact adult animals. In contrast, rats treated with 300 µg estradiol valerate showed a significant increase in the number of prolactin cells (P<0.05). Therefore, the increase in serum prolactin levels observed in rats treated with 50 µg estradiol valerate, in the absence of morphological changes in the pituitary cells, suggests a "functional" estrogen-induced hyperprolactinemia. Bromocriptine decreased prolactin levels in all estrogen-treated rats. The administration of this drug to rats previously treated with 300 µg estradiol valerate also resulted in a significant decrease in pituitary weight and number of prolactin cells when compared to the group treated with estradiol alone. The general antiprolactinemic and antiproliferative pituitary effects of bromocriptine treatment reported here validate the experimental model of estrogen-induced hyperprolactinemic rats

Food intake and weight of lactating rats maintained on different protein-calorie diets, and pup growth

Studies on rats maintained on low-protein-calorie diets during the lactation period show that food intake decreases. This process results in weight loss and a delay in litter development. The purpose of the present study was to determine the alterations in food intake, maternal weight and litter growth during lactation when dams were exposed to diets with different levels of protein and carbohydrate. Female Wistar rats receiving one of 4 different diets, A (N = 14), B (N = 14), C (N = 9) and D (N = 9), were used. Diet A contained 16% protein and 66% carbohydrate; diet B, 6% protein and 77% carbohydrate; diet C, 6% protein and 66% carbohydrate; diet D, 16% protein and 56% carbohydrate. Thus, C and D diets were hypocaloric, while A and B were isocaloric. The intake of a low-protein diet in groups B and C affected the weight of dams and litters during the last two weeks of lactation, while the low-calorie diets limited the growth of D litters at 21 days compared with A litters, but had no effect on the weight of D dams. Group B showed an increase in intake during the first five days of lactation, resulting in a behavioral calorie compensation due to the increase in carbohydrate content, but the intake decreased during the last part of lactation. Food intake regulation predominantly involves the recruitment of a variety of peripheral satiety systems that attempt to decrease the central feeding command system.

Morphological changes of the jejunal mucosa in protracted diarrhea and their correlation with disease duration, weight loss and serum albumin levels

The pathogenesis of protracted diarrhea is multifactorial. In developing countries, intestinal infectious processes seem to play an important role in triggering the syndrome. Thirty-four children aged 1 to 14 months, mean 6.5 months, with protracted diarrhea were studied clinically and in terms of small intestinal mucosal morphology. Mild, moderate or severe hypotrophy of the jejunal mucosa was detected in 82% of cases, and mucosal atrophy was observed in 12%. The intensity of the morphological changes of the jejunal mucosa correlated negatively with serum albumin levels. No correlation was detected between mucosal grading and duration of diarrhea or between mucosal grading and weight reported as percentile. After nutritional support was instituted, serial jejunal biopsies were obtained from 12 patients: five patients submitted to parenteral nutrition for 7 to 38 days, mean 17 days, and 7 patients receiving a hypoallergenic oral diet (semi-elemental formula, 3; chicken formula, 3; human milk, 1). In seven cases (58%) a progressive increase in villus height and a decrease in the number of inflammatory cells were noted. Recovery of the morphologic pattern was accompanied by clinical improvement in all patients

Evidence for the presence of a kininogen-like species in a case of total deficiency of low and high molecular weight kininogens

Low and high molecular weight kininogens (LK and HK), containing 409 and 626 amino acids with masses of ~65 and 120 kDa after glycosylation, respectively, are coded by a single gene mapped to the human chromosome 3 by alternative splicing of the transcribed mRNA. The NH2-termini Glu1-Thr383 region, identical in LK and HK, contains bradykinin (BK) moieties Arg363-Arg371. LK, HK and their kinin products Lys-BK and BK are involved in several biologic processes. They are evolutionarily conserved and only 7 patients, all apparently normal, have been reported to lack them. In one of these patients (Williams' trait), a codon mutation (Arg178 ® stop) has been blamed for the absence of LK and HK. However, using Western blots with 2 monoclonal anti-HK antibodies, one that recognizes the region common to LK and HK and the other that recognizes only HK, I detected ~110-kDa bands in the plasma of this LK/HK-deficient patient vs ~120-kDa bands in normal human and ape plasmas. With polyclonal anti-Lys-BK antibody, which strongly detects BK cleaved at its COOH-terminus in purified HK, I detected ~110-kDa bands in the normal and the deficient plasmas. Western blots with a monoclonal anti-prekallikrein (PK) antibody showed that surface activation of PK and distribution of PK activation products, both dependent on HK, were similar in these plasmas. These findings suggest that a mutant gene yielded a kininogen-like species possibly involving aberrant mRNA splicing - structurally different from normal HK, but apparently with the capacity to carry out seemingly vital HK functions.

Methylmercury intoxication and histochemical demonstration of NADPH-diaphorase activity in the striate cortex of adult cats

The effects of methylmercury (MeHg) on histochemical demonstration of the NADPH-diaphorase (NADPH-d) activity in the striate cortex were studied in 4 adult cats. Two animals were used as control. The contaminated animals received 50 ml milk containing 0.42 µg MeHg and 100 g fish containing 0.03 µg MeHg daily for 2 months. The level of MeHg in area 17 of intoxicated animals was 3.2 µg/g wet weight brain tissue. Two cats were perfused 24 h after the last dose (group 1) and the other animals were perfused 6 months later (group 2). After microtomy, sections were processed for NADPHd histochemistry procedures using the malic enzyme method. Dendritic branch counts were performed from camera lucida drawings for control and intoxicated animals (N = 80). Average, standard deviation and Student t-test were calculated for each data group. The concentrations of mercury (Hg) in milk, fish and brain tissue were measured by acid digestion of samples, followed by reduction of total Hg in the digested sample to metallic Hg using stannous chloride followed by atomic fluorescence analysis. Only group 2 revealed a reduction of the neuropil enzyme activity and morphometric analysis showed a reduction in dendritic field area and in the number of distal dendrite branches of the NADPHd neurons in the white matter (P<0.05). These results suggest that NADPHd neurons in the white matter are more vulnerable to the long-term effects of MeHg than NADPHd neurons in the gray matter.