Similar but not the same: insights into the evolutionary history of paralogous sex-determining genes of the dwarf honey bee Apis florea.

Studying the fate of duplicated genes provides informative insight into the evolutionary plasticity of biological pathways to which they belong. In the paralogous sex-determining genes complementary sex determiner (csd) and feminizer (fem) of honey bee species (genus Apis), only heterozygous csd initiates female development. Here, the full-length coding sequences of the genes csd and fem of the phylogenetically basal dwarf honey bee Apis florea are characterized. Compared with other Apis species, remarkable evolutionary changes in the formation and localization of a protein-interacting (coiled-coil) motif and in the amino acids coding for the csd characteristic hypervariable region (HVR) are observed. Furthermore, functionally different csd alleles were isolated as genomic fragments from a random population sample. In the predicted potential specifying domain (PSD), a high ratio of πN/πS=1.6 indicated positive selection, whereas signs of balancing selection, commonly found in other Apis species, are missing. Low nucleotide diversity on synonymous and genome-wide, non-coding sites as well as site frequency analyses indicated a strong impact of genetic drift in A. florea, likely linked to its biology. Along the evolutionary trajectory of ~30 million years of csd evolution, episodic diversifying selection seems to have acted differently among distinct Apis branches. Consistently low amino-acid differences within the PSD among pairs of functional heterozygous csd alleles indicate that the HVR is the most important region for determining allele specificity. We propose that in the early history of the lineage-specific fem duplication giving rise to csd in Apis, A. florea csd stands as a remarkable example for the plasticity of initial sex-determining signals.

Continuous glucose monitoring in cystic fibrosis patients according to the glucose tolerance.

Cystic fibrosis (CF) is associated with a long preclinical state of abnormal glucose tolerance. The aim of this study was (i) to evaluate the profile of glucose tolerance in young adults with CF and (ii) to compare these results with those obtained by a continuous subcutaneous glucose monitoring (CGMS). CF subjects with fasting glycemia inferior to 126 mg/dl were included in the study. An oral glucose tolerance test (OGTT) identified the subjects either with a normal glucose tolerance (NGT), or impaired glucose tolerance (IGT), or diabetes. CGMS (Medtronic) was performed during 3 days to analyze mean glucose level, high glucose excursions, and glucose area under the curve (AUC). Forty-nine patients were included in the study. NGT (n=22), IGT (n=17), and diabetes groups (n=10) were comparable except with regard to age and BMI (p<0.001). HbA1c values in diabetes group were significantly higher (p<0.001) than in NGT and IGT groups. CGMS revealed peaks of glucose values superior to 200 mg/dl at least once after a meal in 8 patients (36%) with NGT, in 9 patients (52%) with IGT, and in all patients with diabetes (p<0.01). Mean CGMS glucose and glucose AUC values increased in patients with diabetes compared to patients with NGT and IGT (p<0.05). Peak of CGMS glucose reached 182+/-60 mg/dl in NGT group despite the normal glucose profile at OGTT. In conclusion, CGMS revealed pathological glucose excursions not only in patients with impaired glucose tolerance at OGTT but also in patients with a normal glycemic profile. CGMS could be a useful tool for the early detection of hyperglycemia in patients with CF.

Specific developmental gene silencing in the honey bee using a homeobox motif.

Manipulating the expression of genes in species that are not currently used as genetic models will provide comparative insights into the evolution of gene functions. However the experimental tools in doing so are limited in species that have not served as models for genetic studies. We have examined the effects of double stranded RNA (dsRNA) in the honey bee, an insect with considerably basic scientific interest. dsRNA derived from a 300 bp stretch of the E30 homeobox motif was injected into honey bee embryos at the anterior pole in the preblastoderm stage. We found that the dsRNA fragment successfully disrupted the protein expression of the target gene throughout the whole embryo. The disruption caused deficient phenotypes similar to known loss of function mutants of Drosophila engrailed, whereas embryos injected with nonsense dsRNA showed no abnormalities. We show that the large size of the honey bee egg (D: 0.3 mm, L: 1.6 mm) and the long preblastoderm stage (11-12 h) can be exploited to generate embryos with partial disruption of gene function, which may provide an elegant alternative to classical chimeric analyses. This is the first report of targeted disruption of gene function in the honey bee, and the results prove that the chosen target gene is a functional ortholog to engrailed in Drosophila.

[Minimizing losses and maximizing efficiency in the detection of acute severe malnutrition]. / Minimizando perdas e maximizando eficiência na detecção de casos de desnutrição aguda severa.

OBJECTIVE: One of the many challenges faced by epidemiologists is to adequately plan and optimize subject selection procedures in terms of effectiveness and efficiency. In the context of a case-control study involving severe acute malnutrition, a two-step subject selection procedure is used. The aim of the article is to establish an appropriate cut-off point for the screening phase and to achieve a common ground for standards, efficiency in detecting severe malnutrition and the two-step procedure. METHODS: The study includes 154 children under the age of 2 from two different hospitals. To determine the ideal cut-off point of weight-for-age (WFA), the following estimators are of interest: the proportion of false negatives (PFN), false positives (PFP) and the percentage of total gain by time (ptg). Weight-for-height (WFH) (cut-off point at -2 SDs) is used as reference for establishing severe acute malnutrition. RESULTS: The magnitude of false negatives declines steadily until the 3rd WFA percentile (P3) and reaches zero close to P9. At this point, the PFP is around 0.4. The ptg decreases sharply up to P4, declining smoothly towards P10 thereafter (54.5%). CONCLUSIONS: The WFA P10 can be recommended for the screening phase. At this cut-off point, there is still efficiency whereas losses of true cases of severe acute malnutrition are minimized.

Fine scale mapping in the sex locus region of the honey bee (Apis mellifera).

Isolating an unknown gene with fine-scale mapping is possible in a "non-model" organism. Sex determination in honey bees consists of a single locus (sex locus) with several complementary alleles. Diploid females are heterozygous at the sex locus, whereas haploid males arise from unfertilized eggs and are hemizygous. The construction of specific inbred crosses facilitates fine scale mapping in the sex locus region of the honey bee. The high recombination rate in the honey bee reduces the physical distance between markers compared with model organisms and facilitates a novel gene isolation strategy based on step-wise creation of new markers within small physical distances. We show that distances less than 25 kb can be efficiently mapped with a mapping population of only 1000 individuals. The procedure described here will accelerate the mapping, analysis and isolation of honey bee genes.

Blood polyamine levels after oral ornithine load, a diagnostic marker of hyperproliferative premalignant and malignant stages in a model of colon carcinogenesis.

This study was performed to determine whether a single oral dose of ornithine (Orn), the substrate of ornithine decarboxylase (ODC), increases blood concentrations of polyamines premalignant stage, and whether blood polyamine levels could be used as predictive markers of cancer development. Male Wistar rats were divided into two groups, control and 1,2-dimethylhydrazine (DMH)-treated rats. DMH (20 mg/kg body weight) was injected intraperitoneally once weekly for 10 weeks. Five, 7, and 10 weeks after the last injection when premalignant aberrant crypt foci have developed in the colon, blood levels of putrescine (PUT), spermidine (SPD), and spermine (SPM) were estimated before and after an oral load of ORN. The results showed that after a single oral load of Orn, blood PUT, but not SPD and SPM, concentrations were significantly higher in DMH-treated rats compared with control rats, indicating enhancement of ODC activity. These results support the view that the increased blood concentration of PUT after administration of Orn may be a useful marker to detect hyperproliferative premalignant and malignant stages of cancer development.

[Semantic equivalence of the Portuguese version of the Abuse Assessment Screen tool used for the screening of violence against pregnant women]. / Equivalência semântica da versão em português do instrumento Abuse Assessment Screen para rastrear a violência contra a mulher grávida.

INTRODUCTION: Research programs and actions regarding family violence have been growing steadily. Therefore, there's a need to develop data collection tools. In Brazil, further problems come up since tools that have been developed elsewhere need to be adapted and translated. This study focuses on the Abuse Assessment Screening (AAS) used to detect violence against pregnant women. The objective is to evaluate the semantic equivalence between the original tool in English and two Portuguese versions, and propose a synthetic version to be used in the field. METHODS: The evaluation of semantic equivalence was carried out in 4 steps: (1) translation, (2) back translation, (3) formal appreciation of equivalence and (4) a final critical assessment by family violence experts. RESULTS: Translation, back translation and the steps 3 and 4 assessment are presented for each item of the tool, along with the original in English. The text covers each discussion that led to the final version. Both versions were quite similar in 14 out of 15 items. Nevertheless, the second version showed to be slightly more adequate although for some items the decision was to combine both versions or, in one case, use an item from version 1. CONCLUSION: The procedure undertaken in this study is discussed in the light of Herdman et al.'s proposal (1998) regarding transcultural equivalence. The study also stresses the importance of using more than one version in the process and the appropriateness of including an additional step about the assessment of the target population's understanding of the tool.

Promotion of intestinal carcinogenesis by dietary methionine.

The metabolism of the polyamines spermidine and spermine is known to be enhanced in rapidly proliferating cells. Methionine is a precursor of the aminopropyl moieties of these amines. Therefore, it was of interest to study the effects of a methionine supplemented diet on polyamine metabolism and preneoplastic changes occurring in the intestinal tract of rats treated with the chemical carcinogen azoxymethane (AOM). Adult Wistar rats received 15 mg AOM/kg body wt (i.p.) once each week for 2 weeks. Thereafter, the rats were randomly divided into two groups and received controlled isoenergetic diets containing the same amount of folate, choline and vitamin B12 during 12 weeks: one group was kept on a standard diet; the other was fed the same diet, except that 1% L-methionine was added at the expense of carbohydrates. After 12 weeks, the administration of the methionine-supplemented diet stimulated the turnover rate of ileal epithelial cells, indicating enhanced crypt cell proliferation. Furthermore, in this group, a 2-fold increase in the number of aberrant hyperproliferative crypts and the appearance of tumors was observed in the colon. These effects were accompanied by the increased formation of spermidine and spermine due to the enhancement of S-adenosylmethionine decarboxylase activity and by the upregulation of Cdx-1, a homeobox gene with oncogenic potentials. The experimental data do not support the view of a chemopreventive effect of dietary methionine supplementation on intestinal carcinogenesis in rats, even at an early phase of preneoplastic development, but rather suggest that methionine promotes intestinal carcinogenesis.

[Measurement reliability in a study on family violence and severe acute malnutrition]. / Confiabilidade das aferições de estudo sobre violência familiar e desnutrição severa na infância.

INTRODUCTION: This study is nested within a research program related to family violence and severe childhood malnutrition. Its aim is to evaluate the reliability of the data collection process in a case-control study. Four components of the main instrument are addressed: (a) CTS (Conflict Tactics Scales) used to measure violence at the family level; (b) CAGE (Cut-down; Annoyed; Guilty & Eye-opener) questionnaire used to gauge suspicion of drinking problems; NSDUQ (Non-student Drugs Use Questionnaire) used to indicate illicit drug consumption; and (d) height/length measurements. METHOD: Stability (intra-observer or test-retest reliability) and equivalence (inter-observer reliability) were evaluated for the cited components (a), (b) and (c). Information was replicated among the first 50 subjects selected for the underlying case-control study. The Kappa index (k) was used in the analysis. A pseudo-Bayes adjustment was carried out in order to handle estimation problems. Regarding (d), only equivalence was evaluated (n = 73), using the Intraclass Correlation Coefficient as the estimator. RESULTS: By and large, all components showed acceptable stability and equivalence. Regarding stability, the estimates of k were around 0.70, 0.78 and 0.85, for CTS, CAGE e NSDUQ, respectively. With respect to equivalence, k was 1.0 for CTS and NSDUQ and 0.75 for CAGE. Equivalence for height/length estimated through the ICC was 0.99. Nevertheless, some deviant situations were detected and are further discussed. The results point to an adequate standardization of observers and reflect the good quality of the data collection procedure concerning the main study, encouraging the research team to press forward with greater assurance.

Functional and metabolic changes in intestinal mucosa of rats after enteral administration of ornithine alpha-ketoglutarate salt.

BACKGROUND: Ornithine alpha-ketoglutarate salt efficiently improves the nutritional status of protein-depleted patients. Our aim was to explore the effects of ornithine alpha-ketoglutarate supplementation on intestinal physiology in healthy animals. METHODS: Rats were given a nutritive mixture supplemented with ornithine alpha-ketoglutarate (1 g.kg-1 per day) by enteral route for 7 days. Controls received the diet supplemented with casein acid hydrolysate under isoenergetic and isonitrogenous conditions. RESULTS: An adaptive hyperplasia of the villi and an increase in the brush-border hydrolase activities were observed in rats receiving ornithine alpha-ketoglutarate. Because of the high ornithine aminotransferase activity, ornithine alpha-ketoglutarate-derived ornithine was extensively transaminated with a concomitant enhancement of ornithine decarboxylation. Surprisingly, with glutamate and putrescine, the products of ornithine transamination and decarboxylation, gamma-aminobutyric acid accumulated (10-fold to 16-fold) dramatically in the intestinal mucosa of rats treated with ornithine alpha-ketoglutarate. Because gamma-aminobutyric acid formation was completely prevented by the diamine oxidase inhibitor aminoguanidine but was not modified after inactivation of ornithine aminotransferase by 5-fluoromethylornithine, it is evident that gamma-aminobutyric acid is formed in the mucosa from ornithine via putrescine as an intermediate. CONCLUSIONS: It is assumed that enhanced gamma-aminobutyric acid formation in the intestinal mucosa by ornithine alpha-ketoglutarate treatment might be of physiologic importance in the regulatory processes of cell growth and differentiation.

Beneficial effects of L-arginine on intestinal epithelial restitution after ischemic damage in rats.

The polyamines are involved in repair processes after intestinal ischemia. Arginine and ornithine, both precursors of polyamines were therefore expected to exert beneficial effects on mucosal barrier dysfunction. Arginine may also generate NO and there is support for the view that NO may be beneficial after an ischemic insult. Male Wistar rats were given, by gavage, isonitrogenous solutions of L-arginine (0.5 g/kg) or L-ornithine (0.7 g/kg) 17 and 2 h before ischemia. Controls received an isonitrogenous solution of casein hydrolysate (1 g/kg). Transient intestinal ischemia was produced in anesthetized rats by occluding the superior mesenteric artery for 90 min. Intestinal morphology, hydrolase activities, polyamine and cGMP contents, and cell proliferation rates were determined 4 h after reperfusion. Administration of arginine or ornithine did not prevent ischemic damage but accelerated morphological repair, enhanced cell proliferation, and polyamine content was observed. Arginine was significantly more effective than ornithine. Formation of cGMP was enhanced after arginine administration. NG-nitroarginine methylester, an inhibitor of NO synthase, prevented the arginine effects on mucosal repair. We conclude that arginine-derived NO is an important mediator in the restitution of intestinal mucosa by minimizing cell injury during reperfusion.

Polyamines and the recovery of intestinal morphology and function after ischemic damage in rats.

We have followed the time-course of the morphological and functional recovery of intestinal mucosa after 90 min of mesenteric vascular occlusion. At the end of the ischemic period the villi were smashed, but crypts were preserved. Microvillous hydrolase activities showed a dramatic drop when compared with sham-operated controls. Reperfusion was followed by an immediate upsurge of ornithine decarboxylase activity and a significant (p < 0.01) enhancement of putrescine and N1-acetyl-spermidine concentrations, while spermidine and spermine concentrations in mucosal cells decreased. This indicated that, both, de novo synthesis and degradation rates of the polyamines were increased. Treatment with alpha-difluoromethyl-ornithine, a selective inactivator of ornithine decarboxylase prevented the accumulation of active enzyme, but did not prevent morphological healing. It delayed however the recovery of sucrase and aminopeptidase-specific activities. Our results suggest that in addition to de novo synthesis, other sources of polyamines are mobilized to an extent that growth at a normal rate is supported. This indicates that the presence of active ornithine decarboxylase enzyme is not a prerequisite for the restitution of intestinal integrity after ischemia. We suggest that in a situation of inadequate polyamine supply the restoration of vital processes (mucosal regeneration) has priority over the restoration of specific functions.

Soybean oil, blackcurrant seed oil, medium-chain triglycerides, and plasma phospholipid fatty acids of stressed patients.

Thirty-six adult severe head injury and cerebral stroke patients in four intensive-care units were randomized to receive one of three enteral diets for 21 days. These diets, which supplied 45% of calories from fat, differed only in lipid composition. Diet A was comprised of 100% soybean oil, diet B contained a 50:50 (wt/wt) mixture of soybean oil and medium-chain triglycerides (MCTs), and diet C contained 42.5% MCT, 50% soybean oil, and 7.5% blackcurrant seed oils. Plasma phosphatidylcholine and fatty acid composition of plasma total phospholipids were determined before initiating treatment (day 0) and weekly throughout the study. Results indicated that at the start of the study, all patients had low linoleic acid (18:2 omega 6) levels compared with healthy subjects. Emulsion A disturbed the balance between several fatty acids of the omega 6 series, as exemplified by the significant increase in 18:2 omega 6 proportions. In contrast, both emulsions B and C introduced a less-pronounced rise in 18:2 omega 6 associated for emulsion C with a significant increase in dihomo-gamma-linolenic acid (20:3 omega 6) and docosapentaenoic acid (22:5 omega 3) in plasma phospholipids. Furthermore, 18:3 omega 6 change was significantly different between groups A and C and that of 20:3 omega 6 between group A and both groups B and C. Throughout the study, arachidonic acid (20:4 omega 6) exhibited remarkable steady-state levels regardless of the diet. This study shows that providing the injured body with high amounts of 18:2 omega 6 does not lead to high levels of its upper derivatives in plasma phospholipids.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of amino acids in mixtures given by enteral or parenteral route on intestinal morphology and hydrolases in rats.

This study compares the effects of amino acid addition to an elemental liquid diet containing carbohydrates and triglycerides given either intragastrically or intravenously on the morphology and on hydrolase activities in the jejunum and ileum of adult rats. The isocaloric mixtures were administered for 4 days and control rats received an isocaloric laboratory diet orally. Independent of their content in amino acid, all mixtures given intravenously caused a drop in mucosal weight and a shortening of the height of the villi in both the jejunum and ileum. By enteral route, the addition of amino acids to a carbohydrate-triglyceride liquid diet led to the maintenance of normal villus height (this effect being prominent in the ileum) and to a significant increase of jejunal sucrase and aminopeptidase activities when compared with the carbohydrate-triglyceride mixture. Feeding the mixtures by parenteral route caused a significant drop of both enzyme activities. In contrast, lactase activity was generally not modified by the route of nutrient administration or by the composition of the diets. However, the absence of amino acid in the mixture given intravenously caused a specific drop of lactase activity in the ileum. Ileal sucrase activity was lowered dramatically by intragastric or intravenous feeding of the elemental diets. This effect was not modulated by the presence of amino acids. The presence of amino acids caused a significant drop of aminopeptidase activity in the ileum independently of the route of administration when compared with animals receiving the carbohydrate-triglyceride liquid diet.(ABSTRACT TRUNCATED AT 250 WORDS)

Composition of phospholipid fatty acids in red blood cell membranes of patients in intensive care units: effects of different intakes of soybean oil, medium-chain triglycerides, and black-currant seed oil.

Fatty acid composition of phospholipids in red blood cell membranes was studied in 32 severely head-injured or cerebral stroke patients receiving enteral nutrition for 3 weeks. During this study the effects of three diets differing only by their lipid composition were investigated. The daily energy intake of each patient amounted to 2950 kilocalories, of which the lipid fraction represented 45.7%. Diet A contained only soybean oil, diet B consisted of a 50% soybean oil and 50% medium-chain triglycerides mixture, and diet C was an emulsion of 50% soybean oil, 42.5% medium-chain triglycerides, and 7.5% black-currant seed oil. Our results showed no biochemical signs of fatty acid deficiency in red blood cell membranes for the patients at the beginning of the study, after a comparison with a control group of 20 healthy adults. Inhibition of delta 6-desaturase activity on linoleic acid (C18:2 omega 6) after diet A was suggested by an increase of linoleic acid without a corresponding increase of dihomo-gamma-linolenic acid (C20:3 omega 6). Replacing 50% of soybean oil by with medium-chain triglycerides (diet B) prevented this enzyme inhibition. Supply of black-currant seed oil rich in gamma-linolenic (C18:3 omega 6) and stearidonic (C18:4 omega 3) acids (diet C) induced significant increases of dihomo-gamma-linolenic and eicosapentaenoic (C20:5 omega 3) acids, without influencing arachidonic acid (C20:4 omega 6) levels. This balance was evaluated through the ratio (C20:3 omega 6 + C20:5 omega 3)/C20:4 omega 6.

Methylene blue increases systemic vascular resistance in human septic shock. Preliminary observations.

We report the hemodynamic improvements induced by intravenous methylene blue (MB), a guanylate cyclase inhibitor, in 2 patients with hyperdynamic septic shock treated with norepinephrine (NE) infusion, mechanical ventilation and hemodialysis. MB injection augmented the low vascular resistance, mean arterial pressure and induced a slight decrease of cardiac index, without any change of heart rate and pulmonary artery wedge pressure. Plasma cyclic GMP levels decreased without a significant change of atrial natriuretic factor levels. MB (2 mg.kg-1) induced a longer lasting improvement of circulatory failure without deleterious side effects, but did not prevent the occurrence of delayed multiorgan failure or subsequent death. These data suggest that in patients, severe sepsis-induced loss of vascular responsiveness to NE involves activation of soluble guanylate cyclase, possibly stimulated by enhanced nitric oxide production. Furthermore, these observations support the concept that pharmacological blockade of guanylate cyclase may improve hemodynamics but not survival rates.

[Acute fatty liver of pregnancy. Diagnostic value of hyperuricemia in the pre-jaundice stage]. / Un cas de stéatose hépatique aiguë gravidique. Intérêt diagnostique de l'hyperuricémie au stade pré-ictérique.

Acute fatty liver of pregnancy, with a case history where an early diagnosis could have been made, and a review of the French literature. Acute fatty liver of pregnancy, or Sheehan's syndrome is a rare but very serious complication of pregnancy. The disease is demonstrated by vomiting, abdominal pain and a high level of uric acid in the blood before jaundice is noted. Within a few days the triad of jaundice, pruritus and encephalopathy occur. These are often associated with toxaemia of pregnancy and with polyuria and polydipsia. A raised white blood count and a high level of bilirubinemia are almost always present. The outlook is very serious when haemorrhage appears. This malignant form of the disease is characterised by liver and kidney failure. Liver biopsy confirms the diagnosis. The prognosis is related to an early diagnosis and is good when labour is induced or caesarean section performed. Acute fatty liver of pregnancy is an emergency from the diagnostic as well as the therapeutic angles.

[Prognostic factors of decompensated chronic respiratory insufficiency. Apropos of a series of 272 cases]. / Facteurs pronostiques des insuffisances respiratoires chroniques décompensées. A propos d'une série de 272 observations.

Over a 6 years' period (1980-1986), 272 patients with chronic respiratory disease were admitted for respiratory failure to the same intensive care unit. The series was characterized by the high mean age of the patients (69.3 years) and by the high proportion of those who were ventilated (75%); 33.7% of the patients died within 1 month of discharge. The survival rate at 5 years estimated by the actuarial survival curve was 28%. Parameters measured during the acute decompensation phase were analyzed statistically. The main prognostic factors regarded as unfavourable were: old age and associated visceral failure particularly, important loss of weight and muscular atrophy, pre-existing neurological sequelae, left ventricular dysfunction, simplified Le Gall score above 15, presence of respiratory encephalopathy, stroke or viral infection as precipitating factors of decompensation, transfer from other hospital units after failure of medical treatment, and need for mechanical ventilation for more than 30 days.

[Vital capacity restitution curve: prognostic value in chronic decompensated respiratory insufficiency]. / La courbe de restitution de la capacité vitale: intérêt pronostique au cours des insuffisances respiratoires chroniques décompensées.

From a series of 50 patients with acute decompensation of chronic obstructive lung disease (38 of whom were treated by mechanical ventilation), the authors demonstrate the prognostic value of an easily obtained parameter of respiratory function: the vital capacity restitution curve (VCRC). From daily measurements of vital capacity, beginning on the day of admission, a graph is constructed which shows an initial period of increase in the degree of restitution, followed by stabilization of the values. An analysis of the various parameters embodied in this graph provides information about the prognosis. Such graphs can be divided into 3 zones of prognostic value: a favourable zone, an intermediate zone (mediocre survival with or without mechanical ventilation) and an unfavourable zone (death during the acute phase). Although a favourable prognosis can be made after 4 days of observation and almost always by the 10th day, an unfavourable prognosis cannot be made before the 21st day.