Characterization of a cohort of Angolan children with sickle cell anemia treated with hydroxyurea

BACKGROUND

Sickle Cell Anemia (SCA) is a monogenic disease, although its severity and response to treatment are very heterogeneous.

OBJECTIVES

This study aims to characterize a cohort of Angolan children with SCA and evaluate their response to hydroxyurea (HU) treatment and the potential side effects and toxicity.

METHODS

The study enrolled 215 patients between 3 and 12 years old before and after the administration of HU, at a fix dose of 20 mg/kg/day for 12 months.

RESULTS

A total of 157 patients started HU medication and 141 of them completed the 12-month treatment. After initiating HU treatment, the frequency of clinical events decreased (transfusions 53.4 %, hospitalizations 47.1 %). The response to HU medication varied among patients, with some experiencing an increase in fetal hemoglobin (HbF) of <5 %. The mean increase in HbF was 11.9 %, ranging from 1.8 % to 31 %. Responders to HU treatment were 57 %, inadequate responders 38.7 % and non-adherent 4.2 %. No clinical side effects related to HU were reported. Hematological toxicities were transient and reversible. Children naïve to HU and with lower HbF reported higher number of hospitalizations caused by malaria infection. During HU treatment, the frequency of malaria episodes did not appear to be affected by HbF levels.

CONCLUSIONS

the present study provided a valuable contribution to the understanding of the clinical and laboratory profiles of Angolan children with SCA. These findings support the evidence that the implementation of prophylactic measures and treatment with HU is associated with increased survival in children with SCA.

Methods for conservation of intra-varietal genetic variability in ancient grapevine varieties

Conservation of intra-varietal genetic variability is a crucial strategy to preserve traditional viticulture and to face future challenges. Conservation can be performed through two processes: (1) conservation without other immediate objectives; (2) conservation which simultaneously ensures the evaluation of important quantitative traits (such as yield, must quality traits, tolerance to abiotic stresses). The second strategy permits the quantification of intra-varietal genetic variability for important quantitative traits and the selection of a superior group of genotypes (polyclonal selection). Based on the results obtained from the conservation of ancient Portuguese varieties, the abovementioned methods for conservation of intra-varietal diversity are compared, and the advantages and disadvantages of each one are discussed.

Grapevine clonal selection in Portugal: A different approach

The methodology for selection of an ancient grapevine variety conducted by PORVID (Portuguese Association for Grapevine Diversity) and the Portuguese Network for Grapevine Selection, focuses on quantitative genetic tools resulting in an integrated strategy that comprises two types of selected material – clonal and polyclonal – both carrying high genetic and economic gains for relevant agronomic and oenological traits. This work focused on the clonal selection methodology, particularly on the model for communication with users of selected materials (grape growers and winemakers). The approach is innovative, since detailed information of the whole experimental process leading to certified clones is provided, including predicted genetic gains for several traits and information about the clone's environmental stability (G × E interaction). This last analysis, combined with the utilisation of several certified clones (approximately 7), contributes to a better adaptation to environmental changes.

Effect of oral administration of Tribulus terrestris extract on semen quality and body fat index of infertile men

Male fertility can be evaluated through complete semen analysis. Plants belonging to the Tribulus genus are known for their role in enhancing sex hormone levels and semen quality. The aim of this study was to evaluate the effects of T. terrestris on semen quality and physiological parameters. Sixty-five men with abnormal semen evaluation were included in this study, in which they were prescribed with oral administration of Androsten^® (250 mg of Tribulus terrestris dried extract per capsule). Body fat percentage, lean muscle mass gain, fluctuation in steroid hormone levels and all semen parameters were analysed during the period of treatment. The results demonstrated that decrease in the percentage of body fat and increase in lean mass were significant, as well as increase in dihydrotestosterone levels. Complete semen analysis evaluated at the end of treatment showed significant enhancement in sperm concentration, motility and liquefaction time. Protodioscin, the main phytochemical agent of the Tribulus genus, acts on sertoli cells, germ cell proliferation and growth of seminiferous tubules. This component is known to convert testosterone into dihydrotestosterone, which plays important roles in male attributes. Our results indicate the therapeutic use of Tribulus terrestris by men presenting altered semen parameters, and/or undergoing infertility treatment.

Comparison of digit ratio (2D:4D) between Brazilian men with and without prostate cancer

BACKGROUND

Digit ratio (2D:4D) has been suggested as a proxy biomarker for prenatal androgen activity and has been linked to prostate cancer, as the genes that regulate the formation and differentiation of the fingers are also related to the carcinogenesis of prostate cancer. To investigate the possible correlation between right hand, left hand and right hand minus left hand (DR-L) 2D:4D and prostate cancer of Brazilian subjects by comparing 2D:4D ratios of individuals diagnosed with prostate cancer and individuals without the disease. Also, to inquire the relationship between 2D:4D and severity of prostate cancer through Gleason scores.

METHODS

Digital measurements of the lengths of the index and ring fingers of both hands of patients diagnosed with prostate cancer (PCA group, n=100) and healthy control individuals (n=100) were obtained using a digital vernier caliper. Means of the 2D:4D ratios were compared. Data were analyzed by the Student's t-test for unpaired samples, Mann-Whitney test and Spearman's correlation with a significance level of 5%.

RESULTS

The PCA group presented significantly lower right and left 2D:4D (P=0.001 and P=0.002, respectively) in comparison to healthy controls, but DR-L were not significantly different between groups (P=0.589). In addition, digit ratios were not correlated to Gleason score for either hand or in DR-L.

CONCLUSIONS

2D:4D seems to be a marker for screening patients for prostate cancer in an admixed population, as males with prostate cancer present lower 2D:4D than healthy subjects. On the other hand, 2D:4D does not appear to be associated with the severity of prostate cancer.

A model integration approach linking signalling and gene-regulatory logic with kinetic metabolic models

Systems biology has to increasingly cope with large- and multi-scale biological systems. Many successful in silico representations and simulations of various cellular modules proved mathematical modelling to be an important tool in gaining a solid understanding of biological phenomena. However, models spanning different functional layers (e.g. metabolism, signalling and gene regulation) are still scarce. Consequently, model integration methods capable of fusing different types of biological networks and various model formalisms become a key methodology to increase the scope of cellular processes covered by mathematical models. Here we propose a new integration approach to couple logical models of signalling or/and gene-regulatory networks with kinetic models of metabolic processes. The procedure ends up with an integrated dynamic model of both layers relying on differential equations. The feasibility of the approach is shown in an illustrative case study integrating a kinetic model of central metabolic pathways in hepatocytes with a Boolean logical network depicting the hormonally induced signal transduction and gene regulation events involved. In silico simulations demonstrate the integrated model to qualitatively describe the physiological switch-like behaviour of hepatocytes in response to nutritionally regulated changes in extracellular glucagon and insulin levels. A simulated failure mode scenario addressing insulin resistance furthermore illustrates the pharmacological potential of a model covering interactions between signalling, gene regulation and metabolism.

Molecular diagnosis of haemophilia A at Centro Hospitalar de Coimbra in Portugal: study of 103 families--15 new mutations

Haemophilia A (HA), the most commonly inherited bleeding disorder, has well known phenotype heterogeneity, influenced by the type of mutation, modulating factors and development of inhibitors. Nowadays, new technologies in association with bioinformatics tools allow a better genotype/phenotype correlation. With the main objective of identifying familial carrier women and to offer prenatal diagnosis, 141 HA patients belonging to 103 families, followed or referred to the Haemophilia Centre of CHC, E.P.E., were studied. Molecular diagnosis strategy was based on HA severity: IVS22 and IVS1 inversions, direct sequencing and MLPA technique. New missense and splicing mutations were further analyzed using molecular modelling. Genotype/phenotype correlation was assessed taking into account the known modulating factors. During this study, mutations were detected in 102/103 families, carrier status was determined in 83 women and 14 prenatal diagnoses were performed. In a total of 46 different mutations identified, 15 have not been reported previously by the HAMSTeRS and HGMD. Genotype/phenotype correlation revealed two cases with a clinical picture less severe than expected by the type of mutation identified. Six patients developed inhibitors: five severe (IVS22, IVS1, large deletion) and one mild (p. Gln2265Lys). The adopted strategy allowed the identification of 99% of the molecular alterations underlying the HA phenotype (98% detection rate for severe and 100% for moderate and mild). Evaluation of genotype-phenotype correlation was complemented with structural protein modelling of newly identified missense mutations, contributing to better understanding of the disease-causing mechanisms and to deepening knowledge on protein structure-function.

Experimental designs for evaluation of genetic variability and selection of ancient grapevine varieties: a simulation study

Classical methodologies for grapevine selection used in the vine-growing world are generally based on comparisons among a small number of clones. This does not take advantage of the entire genetic variability within ancient varieties, and therefore limits selection challenges. Using the general principles of plant breeding and of quantitative genetics, we propose new breeding strategies, focussed on conservation and quantification of genetic variability by performing a cycle of mass genotypic selection prior to clonal selection. To exploit a sufficiently large amount of genetic variability, initial selection trials must be generally very large. The use of experimental designs adequate for those field trials has been intensively recommended for numerous species. However, their use in initial trials of grapevines has not been studied. With the aim of identifying the most suitable experimental designs for quantification of genetic variability and selection of ancient varieties, a study was carried out to assess through simulation the comparative efficiency of various experimental designs (randomized complete block design, alpha design and row-column (RC) design). The results indicated a greater efficiency for alpha and RC designs, enabling more precise estimates of genotypic variance, greater precision in the prediction of genetic gain and consequently greater efficiency in genotypic mass selection.

Tobacco Smoking and Motivation to Quit in Psychiatric Patients

Introduction:

Smoking is a major health risk in the population in general with significantly increased morbility/mortality with severe consequences on the quality of life and tremendous economic burden on society. It is well known that psychiatric patients have an even higher prevalence of smoking, of heavy smokers and of other risk factors that contribute to the same illnesses.

Non-smoking campaigns/smoking restrictions have flourished and it appears that more people are quitting or seriously contemplating the idea. When once, many non-smokers tolerated smokers, today the stigma associated with smoking is undeniable. Psychiatric patients, already greatly stigmatized, risk even becoming more so. Furthermore, smoking cessation programs and interventions frequently are not available, exclude many psychiatric patients and/or are ill-adapted to the special needs in this patient population.

Aim:

To establish the prevalence of smoking, quantity of tobacco smoked, other factors of dependence by psychiatric diagnosis in a portuguese psychiatric hospital.

Establish the motivation of these patients to seek help by professionals and motivation to quit.

Methods:

Application of questionnaires including Fagerstrom's Modified Questionnaire to patients under care by one team of a Psychaitric hospital in Lisbon, Portugal (CHPL - Sector A).

Discussion and conclusions:

The study is under way therefore, there are no valid conclusions yet.

Certainly it will be possible to confirm high levels of smoking tobacco in this patient population. Hopefully, we may also conclude that there is the desire to change smoking habits making cessation programs a needed and welcomed intervention in psychiatric settings.

[Necrotizing fasciitis after varicella]

Necrotizing fasciitis is a rare and severe infection characterised by extremely rapid progressive involvement of the superficial fascias and deep dermal layers of the skin, with resultant vasculitis and necrosis. The authors present three clinical cases of necrotizing fasciitis; all three patients previously had varicella rash, rapid progressive spreading erythema with severe pain and toxic shock syndrome. Two patients had positive cultures of b-haemolytic streptococcus. Early stage differential diagnosis with celulitis, aggressive antibiotic treatment and pediatric intensive care support are essential. However, the main therapy is early extensive surgical approach involving all indurate areas, down to and including the muscle fascia.

Antioxidant activity of 5-aminosalicylic acid against peroxidation of phosphatidylcholine liposomes in the presence of alpha-tocopherol: a synergistic interaction?

Oxidative damage has been implicated in the pathogenesis of inflammatory bowel diseases. 5-Aminosalicylic acid (5-ASA), the anti-inflammatory drug commonly used in the treatment of this condition, has been shown to possess antioxidant properties considered to be of particular importance in the pathologic context of these diseases. However, its action mechanisms are far from being completely elucidated, especially regarding its antioxidant properties in the presence of endogenous antioxidants such as alpha-tocopherol (alpha-T), the major defence system of biomembranes against lipid peroxidation. In this study we investigated the scavenging activity of 5-ASA toward peroxyl radicals generated at different sites of soybean PC liposomes, used as model membranes, either alone or in combination with alpha-T. 5-ASA, separately, shows strong scavenging activity toward peroxyl radicals generated in the aqueous phase by thermal decomposition of 2,2'-azobis(2-amidinopropane hydrochloride) (AAPH), inducing a clear concentration-dependent inhibition period, either of oxygen consumption or of conjugated diene hydroperoxides production. HPLC analysis indicates that 5-ASA is consumed, at a constant rate, throughout the reaction, and when the inhibition period is over, the oxidation rate is resumed. On the other hand, apart from a slight decrease in the rate of oxidation, 5-ASA is unable to suppress efficiently lipid peroxidation, when the reaction starts inside the lipid membranes, by thermal decomposition of 2,2'-azobis(2,4-dimethylvaleronitrile) (AMVN). When 5-ASA is combined with alpha-T, and the oxidation starts in the aqueous phase, an additive inhibitory effect occurs between both compounds. 5-ASA protects efficiently alpha-T against initial attack from AAPH-peroxyl radicals, delaying its consumption. On the other hand, if the reaction starts inside the lipid bilayer, 5-ASA prolongs significantly the inhibitory period produced by alpha-T on the initial rate of oxidation, as measured by oxygen consumption and conjugated diene hydroperoxides. This inhibitory effect points to a synergistic interaction between 5-ASA and alpha-T, since 5-ASA, by itself, is unable to suppress the oxidation reaction. Therefore, 5-ASA reveals an important cooperative effect with alpha-T, either affording an efficient protection to this antioxidant compound, when free radicals are generated in the aqueous site, or potentiating its activity when oxidation is initiated inside the lipid bilayer. Taking into account that the ascorbic acid content decreases significantly in the inflamed mucosa of patients with inflammatory bowel diseases, our data are, certainly, a very important contribution to the knowledge of the anti-inflammatory action of 5-ASA.

[Are there any arguments against hormone replacement therapy after treatment of ovarian adenocarcinoma?]

The hormonal status of 95% of the women treated for epithelial ovarian carcinoma is menopausal, either naturally or after treatment. This raises the important question of the hormonal replacement therapy (HRT) among these patients. Several retrospective studies have explored the potential positive or negative influence of HRT on the genesis of ovarian adenocarcinoma. Although somehow contradictory, these studies taken all together fail to show any favouring nor protective role of HRT. In vitro, estrogens have been shown to induce the proliferation of ovarian cancer cell lines. On the opposite, progesterone and antiestrogens have antiproliferative effects. Both types of effects are mediated by intracellular steroid hormone receptors (ER, PgR). Although high dose progesterone derivatives and antiestrogens have been shown to obtain therapeutic responses in patients carrying advanced ovarian carcinoma, response rates were usually less than 20%, and no clinico-biological correlation (with ER, PgR status) could be demonstrated. There is therefore no evidence for a clinical significance of the presence of hormonal receptors in these tumors. A single retrospective study explored the possible influence of HRT on the prognosis of patients treated for ovarian carcinoma, and did not demonstrate any deleterious effect. This review of recent epidemiological, biological and clinical data fails to find any argument against the prescription of HRT in patients treated for ovarian adenocarcinoma, in the absence of other contra-indications.

Maternal and perinatal implications of the use of human recombinant erythropoietin

BACKGROUND

The use of human recombinant erythropoietin (rHuEPO) in pregnant patients has been limited by the fear of eventual maternal and fetal repercussions (either direct or indirect).

METHODS

The authors present their experience with the use of rHuEPO during pregnancy, with two pregnant women with kidney transplants and in three others with chronic renal insufficiency (one with diabetic nephropathy, another dialysis dependent), all with hematocrit below 30% and adequate iron reserves.

RESULTS

Three of the patients had needed blood transfusions before beginning therapy, and another needed transfusion after significant metrorrhagia. The length of the treatment varied between 2 and 23 weeks and the hematocrit at delivery varied between 26% and 36%. Secondary effects (appearance or worsening of hypertension and seizures) were nil. There was one fetal death at 23 weeks of pregnancy (following an abruptio placenta), two neonates weighing between the 5th and the 10th percentiles, and three needing phototherapy (1 to 2 days). One year after birth, all showed a normal ponderal and neurologic development.

CONCLUSIONS

Among the cases presented, no maternal and perinatal complications attributable to rHuEPO were registered. It is important that institutions report their experiences with the use of rHuEPO, given its restrictive indications and the limited experience of each institution.

Synthesis and properties of N-bromoacetyl-L-thyroxine

A one-step bromoacetylation of L-thyroxine (T4) produces N-bromoacetyl-L-thyroxine (BrAcT4) in good yield. The reaction product is best purified by high-speed countercurrent chromatography. While HPLC is satisfactory only for purification of microgram and submicrogram quantities, amounts ranging from about 1 ng to 1 g of BrAcT4 can be processed by high-speed countercurrent chromatography (HSCCC), a method which we have previously used for the purification of N-bromoacetyl-3,3',5-triiodo-L-thyronine (BrAcT3). Operating conditions for the one-step synthesis of BrAcT4 and BrAcT3 differ due to differences in solubility and reactivity of the two hormones. BrAcT4 purified by HSCCC and shown to be pure by analytical HPLC has been characterized by alpha max and epsilon max in the near and far uv in several solvents, mass spectrum, 1H NMR spectrum, TLC in three solvent systems, retention time in reverse-phase HPLC (C18) in relation to the retention times of two internal standards, 3,3',5-triiodo-L-thyronine and T4, and melting point. Corresponding data for BrAcT3, not previously reported, have also been determined. The described procedure can provide not only substantial amounts of highly purified BrAcT4 for competition studies, but also 125I-labeled BrAcT4 of high specific activity for affinity labeling. Since solutions of BrAcT4 and of BrAcT3 undergo partial decomposition on evaporation to dryness, suitable procedures for the preparation of these hormones in solid form and for storage in solutions have been devised.

Synthesis and characterization of N-bromoacetyl-3,3',5-triiodo-L-thyronine

N-Bromoacetyl-3,3',5-triiodo-L-thyronine and carrier-free [3'-125I]-N-bromoacetyl-3,3',5-triiodo-L-thyronine, to be used for affinity labeling of thyroid hormone receptors, were synthesized using a one-step procedure: a solution of the thyroid hormone 3,3',5-triiodo-L-thyronine and bromoacetyl bromide in ethyl acetate was refluxed for an optimal period of time which depends on the amount of hormone processed. The bromoacetylated hormone thus obtained was then fractionated by high-speed counter-current chromatography which yielded N-bromoacetyl-3,3',5-triiodo-L-thyronine that was pure by the criteria of high-performance liquid chromatography and thin-layer chromatography with different solvent systems. The pure product was well separated from all contaminants including one which in high-performance liquid chromatography was not easily separated from N-bromoacetyl-3,3',5-triiodo-L-thyronine. The latter was characterized by 1H nuclear magnetic resonance, plasma desorption mass spectrometry, thin-layer chromatography, high-performance liquid chromatography, UV spectrophotometry, and melting point. Amounts of 3,3',5-triiodo-L-thyronine ranging from picograms, including carrier-free 125I-labeled triiodothyronine, to 200 to 300 mg can be processed with the equipment used in the present investigation.

High-affinity binding of thyroid hormones to neuroblastoma plasma membranes

The binding of thyroid hormones to isolated plasma membranes was studied in NB41A3 neuroblasts. Saturable binding of L-T3, D-T3 and L-T4 was observed. Binding was time-dependent, with equilibrium reached in less than 60 min and maximal binding occurring between pH 7.4 and 7. Saturation experiments demonstrated two classes of sites for L-T3: a high-affinity site with Ka 8.4 X 10(9) M-1 and a low-affinity site with Ka 7.3 X 10(6) M-1.L-T3 and D-T3 inhibited each other's binding, L-T3 being several-times more potent. Affinity labeling of isolated membranes with bromoacetylated thyroid hormones disclosed stereospecific binding to SDS-PAGE bands with approximate molecular masses of 27 kDa (preferentially labeled by BrAc-L-T3), 32 kDa (preferentially labeled by BrAc-D-T3), and 48 and 87 kDa (preferentially labeled by BrAc-L-T4). Binding of BrAc-L-T3 to the 27 kDa band accounted for 3.4% of total binding, was selectively inhibited by excess L-T3, and may be involved in intracellular transport of L-T3.

The influence of nutritional status on skin anergy in experimental cancer

Malignant tumours as well as severe malnutrition can interfere with carcass weight, serum albumin and delayed hypersensitivity tests. In order to identify the separate effects of these two phenomena, Wistar rats were submitted to various nutritional manipulations prior to Walker-256 carcinosarcoma inoculation (TU). Six groups of well-nourished rats with positive response to the Keyhole Limpet Haemocyanin (KLH) test were studied. Three TU-bearing groups were established, [1] protein-deprived before and after TU (group DDT), [2] protein deprived before TU and later brought back to normal chow (group DNT), and [3] those receiving a complete diet throughout the experiment (group NNT). Identical control groups without TU, sham-injected, were called DDC, DNC and NNC. Tumour size and body weight were measured daily. KLH tests were done sequentially and serum albumin was determined at sacrifice. Results indicated that cancer produced marked changes in immune response. Malnutrition was responsible for anergy and weight loss, and further aberrations tended to occur when both conditions were present. Feeding was able to restore body weight and KLH response in tumour-bearing as well as in control rats, but subsequent deterioration occurred in cancer bearing rats after the first week of tumour development. It is concluded that cancer potentiates the effects of malnutrition, on body weight and immune response, but temporary recovery could be demonstrated after adequate refeeding.

Triiodothyronine transport into differentiated and undifferentiated mouse neuroblastoma cells (NB41A3)

The mechanism of T3 entry into cells was studied in undifferentiated NB41A3 neuroblasts and after differentiation with 0.5 mM sodium butyrate. In undifferentiated neuroblasts, cell uptake of labeled L-T3 at 2 h was reduced to 43% of the control value by excess L-T3, whereas only 5.9% of D-T3 uptake was saturable. After incubation of intact cells with labeled hormone, the nuclei contained 3.8% of the total cellular L-T3 and 4.3% of D-T3. Thus, L-T3 nuclear uptake was 3 times higher than D-T3. Kinetic analysis of the initial rate of uptake of L-T3 by the cells gave a Km of 1.25 nM and a maximum velocity of 2.38 fmol/min.10(6) cells. The initial rate of D-T3 uptake was not saturable. Inhibitors of ATP production (antimycin and oligomycin) as well as monodansylcadaverine virtually abolished saturable cell uptake and decreased nuclear uptake more than total cell uptake, suggesting that the saturable component of uptake into the cells is the major source of nuclear L-T3. After differentiation by butyrate, both cell uptake and nuclear uptake of L-T3 increased. The apparent affinity (Ka) of the nuclear T3 receptors was determined in intact cells and compared with the Ka measured with isolated nuclei. In undifferentiated cells, the apparent Ka was 3-fold higher than the true Ka, presumably due to a step-up in the free T3 concentration in the cytosol compared to that in the incubation medium. After butyrate exposure, the apparent nuclear Ka was decreased to less than 1.5 times the control value, but Ka in isolated nuclei was unchanged. The number of nuclear receptors, however, was increased by butyrate in both intact cell and isolated nuclei experiments. These results indicate that butyrate exerts separate effects on the number of nuclear receptors and saturable T3 transport in mouse neuroblasts.