Size-Induced Depression of First-Order Transition Lines and Entropy Jump in Extremely Layered Nanocrystalline Vortex Matter.

We detect the persistence of the solidification and order-disorder first-order transition lines in the phase diagram of nanocrystalline Bi_{2}Sr_{2}CaCu_{2}O_{8} vortex matter down to a system size of less than one hundred vortices. The temperature location of the vortex solidification transition line is not altered by decreasing the sample size although there is a depletion of the entropy jump at the transition with respect to macroscopic vortex matter. The solid order-disorder phase transition field moves upward on decreasing the system size due to the increase of the surface-to-volume ratio of vortices entailing a decrease on the average vortex binding energy.

Negative symptoms in drug-naive patients with a first-episode psychosis (FEP).

INTRODUCTION: Negative symptoms are nuclear features of schizophrenia that may be present from the onset of the disease. In recent years, it has been described 2 subdomains of negative symptoms: experiential and expressive deficits. The aim of the study is to examine the relationship between negative symptoms and demographic and clinical variables in patients with first-episode psychosis. Also, to explore whether there are differences in the association among these variables and negative symptoms when divided into both subdomains. MATERIAL AND METHODS: A cross-sectional study was performed in 160 patients (52 females and 108 males) with a diagnosis of a first episode psychosis. A questionnaire was administered to collect demographic and clinical variables. RESULTS: A backward stepwise linear regressions analysis was performed in order to observe potential associations between demographic and clinical variables and the presence of negative symptoms. All three models are predicted by worse PSP score, a higher CDSS, a higher disorganized factor score and a lower excited factor score. A longer duration of untreated psychosis (DUP) is associated to a higher score in the experiential deficit subdomain only. CONCLUSIONS: Our work highlights some clinical and phenomenological differences between experiential and expressive deficits. We think that taking into account both subdomains in future studies may lead to more accurate clinical assessment and interventions.

Triggering with GnRH agonist in oocyte-donation cycles: oestradiol monitoring is not necessary during ovarian stimulation.

This prospective observational study evaluated the efficacy and safety of oocyte-donation cycles triggered with a gonadotrophin-releasing hormone (GnRH) agonist without monitoring oestradiol concentrations during ovarian stimulation. A total of 97 oocyte donors received recombinant FSH (150-225/day) and GnRH antagonists (0.25mg/day). Oocyte maturation was triggered with 0.2mg triptorelin s.c. Donors aged 25.4 ± 4.1 years were stimulated for 8.8 ± 0.9 days and underwent 2.9 ± 0.5 (2-4) ultrasound assessments. Total FSH dose was 1703.4 ± 304.7IU, antagonists were administered for 4.3 ± 1.0 days, 14.7 ± 8.8 oocytes were retrieved and there were no cases of ovarian hyperstimulation syndrome. Recipients (n=123) aged 40.3 ± 3.4 years received 10.9 ± 4.3 oocytes, 88.7% of which were metaphase II. Intracytoplasmic sperm injection fertilization rate was 79% and 2.18 ± 0.6 (1-3) embryos were transferred. The pregnancy, clinical pregnancy and twin pregnancy rates were 64.2%, 57.7% and 19.7%, respectively. In conclusion, given the high efficacy and safety of the GnRH-antagonist protocol triggered with a GnRH agonist, the monitoring of oestradiol concentrations is not necessary. Ultrasound monitoring is enough for an adequate follow up of the stimulation cycle in oocyte donors.

Predicting ovarian reserve and reproductive outcome using antimüllerian hormone (AMH) and antral follicle count (AFC) in patients with previous assisted reproduction technique (ART) failure.

PURPOSE OF INVESTIGATION: The main objective of our prospective, observational, analytical research work was to determine whether Anti-Müllerian hormone (AMH) and antral follicle count (AFC) could be effectively used as predictors of ovarian reserve and, possibly, of reproductive outcome with ART. METHODS: We studied 143 IVF/ET cycles in patients with a previous history of ART failure, all of them supposed to be of poor prognosis, who had agreed to another ART attempt after knowing their AMH, AFC, and base hormone (FSH, LH, 17 beta-estradiol) levels. RESULTS: AMH and AFC showed a positive correlation with the number of oocytes retrieved (p = 0.0016) and (p < 0.0001), respectively and with percentage of MII oocytes, (p = 0.00756) and (p < 0.001). The combined use of these markers showed an area under the curve of 82.2% for oocytes retrieved. Our results shows a very high cancelation (22% of started cycles) and very low pregnancy rates (6.7% and 9.8%) in low and normoresponders, respectively. CONCLUSIONS: AMH levels and AFC are reliable indicators of ovarian reserve. Patients with ovarian reserve levels that predict a very low probability of success should be informed that the poor prognosis associated with these values may not justify the expense of IVF/ET.

Cycles triggered with GnRH agonist: exploring low-dose HCG for luteal support.

The aim of this study in patients at risk of ovarian hyperstimulation syndrome (OHSS) was to determine the efficacy and safety of luteal support using human chorionic gonadotrophin (HCG) after triggering ovulation with gonadotrophin-releasing hormone (GnRH) agonist in IVF/intracytoplasmic sperm injection antagonist cycles. A total of 192 OHSS-risk patients, following a GnRH antagonist protocol (0.25mg/day cetrorelix) during recombinant FSH stimulation, were triggered with 1.5mg s.c. leuproreline for ovulation. A total of three boluses of HCG were used for luteal support, 1000IU (group A, n=44), 500IU (group B, n=115) or 250IU (group C, n=33) every third day, starting the day after oocyte retrieval. For the reproductive outcome, main variables were biochemical and clinical pregnancy rates, and for OHSS, the variables were the numbers of moderate and severe OHSS cases. Overall pregnancy rate was 51.8% and clinical pregnancy rate was 43.4%. This study observed eight cases of moderate (4.2%) and seven of severe OHSS (3.6%). Six out of the seven (85.7%) severe cases were late-onset OHSS, related to pregnancy. In conclusion, GnRH agonist single dose for triggering ovulation and low doses of HCG used as luteal-phase support seem to secure a normal pregnancy outcome without increasing the OHSS risk.

Sexual dysfunction in drug- naïve first episode nonaffective psychosis patients. Relationship with prolactin and psychotic symptoms. Gender differences.

BACKGROUND: Our aim is to examine differences in sexual functioning (SF) between patients with drug-naïve first episode psychosis (FEP) and healthy controls (HC). We will also examine correlations between prolactin levels, testosterone levels and psychotic symptomatology with SF from a gender perspective. METHODS: Cross-sectional study. We included 68 FEP patients and 50 HC. A blood sample was extracted. We used the Positive and Negative Syndrome Scale to assess symptom severity, using the five factor structure according to Emsley. The Changes in Sexual Function Questionnaire (CSFQ) was administered. RESULTS: We found significantly better SF in HC than in patients (in CSFQ total score (p = 0.032) and in CSFQ Desire (p = 0.032)). A significant correlation between prolactin or testosterone and SF was not observed. We found a negative significant correlation between the disorganised subscale of the EMSLEY and total CSFQ (p = 0.027; r = -0.329), CSFQ Desire (p = 0.028; r = -0.329) and CSFQ Arousal (p = 0.026; r = -0.332) in the patient sample. In a regression model, we found sex (p = 0.003) and disorganized symptoms (p = 0.034) as significant predictors. CONCLUSIONS: We found evidence for better SF in HC than in FEP patients. We could not confirm an association between prolactin or testosterone and SF. Disorganized symptomatology could be a relevant factor in SF.

The GK rat beta-cell: a prototype for the diseased human beta-cell in type 2 diabetes?

Increasing evidence indicates that decreased functional beta-cell mass is the hallmark of type 2 diabetes (T2D) mellitus. Nowadays, the debate focuses on the possible mechanisms responsible for abnormal islet microenvironment, decreased beta-cell number, impaired beta-cell function, and their multifactorial aetiologies. This review is aimed to illustrate to what extend the Goto-Kakizaki rat, one of the best characterized animal models of spontaneous T2D, has proved be a valuable tool offering sufficient commonalities to study these aspects. We propose that the defective beta-cell mass and function in the GK model reflect the complex interactions of multiple pathogenic players: (i) several independent loci containing genes responsible for some diabetic traits (but not decreased beta-cell mass); (ii) gestational metabolic impairment inducing an epigenetic programming of the pancreas (decreased beta-cell neogenesis and/or proliferation) which is transmitted to the next generation; and (iii) loss of beta-cell differentiation due to chronic exposure to hyperglycemia/hyperlipidemia, inflammatory mediators, oxidative stress and to perturbed islet microarchitecture.

High doses of GnRH antagonists are efficient in the management of severe ovarian hyperstimulation syndrome.

OBJECTIVE: To determine whether treatment of severe ovarian hyperstimulation syndrome (OHSS) with high-dose gonadotropin-releasing hormone (GnRH) antagonist, due to its luteolytic effect, is an effective method of management. METHODS: Six infertile patients who had been scheduled for embryo transfer and developed early-onset severe OHSS with ascites and hemoconcentration were chosen for treatment with 3.0 mg of a GnRH antagonist (Cetrotide; Cetrorelix, Serono, Madrid, Spain). The response of these patients was compared with five patients with severe early-onset OHSS who received support therapy alone. All patients were evaluated clinically, echographically, and hematologically. RESULTS: Estradiol (E2) levels dropped significantly a few days after treatment. Peritoneal fluid regression measured by ultrasound was faster on the study group compared with controls. Hematocrit remained comparable in both groups during follow-up. In two cases a second bolus of GnRH-antagonist was used due to clinical and biochemical findings during the four days of observation following the initial dose. None of the patients treated with GnRH antagonists required paracentesis. CONCLUSIONS: Treatment with high doses of GnRH antagonists seems to be effective in the management of severe OHSS.

Acyclovir delivery matrices based on poly(ethylene glycol)/chitosan semi-interpenetrating networks.

Chitosan matrix systems have been studied as potential vehicles for the prolonged release of acyclovir (ACV). The influence of chitosan concentration (from 0.83% to 1.67%) on viscoelastic properties of formulations with and without glyoxal was analyzed. For chitosan-poly(ethylene glycol) 400 formulations loss modulus (G'') are greater than storage modulus (G'). This corresponds to the characteristic behavior of nonstructured systems. When glyoxal was added to the chitosan-poly(ethylene glycol) 400 formulations, gelled matrix was obtained (i.e., G' is higher than G''), except for the lowest chitosan concentration. ACV release rates for the both types of systems, with and without glyoxal, were also determined. The ACV diffusion coefficient values from matrices are less than for the respective formulation without glyoxal and it was found to depend on the crosslink density within the matrices. Viscoelastic parameters, dynamic moduli (G', G''), and complex viscosity (eta*), were correlated with the ACV diffusion coefficients (D). The complex viscosity (eta*) could be used as a parameter of predictive value for the release rate of drugs.

A halocin acting on Na+/H+ exchanger of haloarchaea as a new type of inhibitor in NHE of mammals.

The capability of halocin H6 (a bacteriocin-like protein produced by haloarchaea Haloferax gibbonsii) to inhibit Na+/H+ exchanger (NHE) in mammalian cells and its cardio-protective efficacy on the ischemic and reperfused myocardium were evaluated in the present study. H6 inhibits NHE activity (measured by a flow cytometry method) in a dose-dependent form of cell lines of mammalian origin (HEK293, NIH3T3, Jurkat and HL-1) as well as in primary cell culture from human skeletal muscle (myocytes and fibroblasts). In vivo, an ischemia-reperfusion model in dogs by coronary arterial occlusion was used (two hours of regional ischemia and three hours of reperfusion). In animals treated with halocin H6 there was a significant reduction of premature ventricular ectopic beats and infarct size, whereas blood pressure and heart rate remained unchanged. Up to date, halocin H6 is the only described biological molecule that exerts a specific inhibitory activity in NHE of eukaryotic cells.

Site-bond percolation of polyatomic species.

A generalization of the classical monomer site-bond percolation problem is studied in which linear k-uples of nearest neighbor sites (site k-mers) and linear k-uples of nearest neighbor bonds (bond k-mers) are independently occupied at random on a square lattice. We called this model the site-bond percolation of polyatomic species or k-mer site-bond percolation. Motivated by considerations of cluster connectivity, we have used two distinct schemes (denoted as S intersection of B and S union of B) for k-mer site-bond percolation. In S intersection of B(S union of B), two points are said to be connected if a sequence of occupied sites and (or) bonds joins them. By using Monte Carlo simulations and finite-size scaling theory, data from S intersection of B and S union of B are analyzed in order to determine the critical curves separating the percolating and nonpercolating regions.

Birth weight and obstetric complications determine age at onset in first episode of psychosis.

BACKGROUND: Earlier age at onset of psychosis (AOP) has been associated with poor social adjustment and clinical outcome. Genetic and environmental factors such as obstetric complications, parental history of psychosis, advanced paternal age at time of birth, low birth weight and gestational age, and use of drugs have been described as bringing AOP forward. This study aims to evaluate the relationship between AOP and these factors in a sample of first episode of psychosis (FEP) patients. METHODS: Clinical and sociodemographic data, age at FEP, age of parents at birth, parental history of psychosis, drug-use habits of the mother during pregnancy and of the patient before psychotic onset, and Lewis and Murray obstetric complication scale were obtained from 90 patients with FEP. Statistical analysis was performed by means of Pearson correlations, Chi-square tests, Student T-test analyses and a linear regression model using SPSS version 22. RESULTS: Pre-eclampsia, need for incubator at birth, use of forceps, parental history of psychosis, and low birth weight were associated with an earlier AOP. Use of forceps and birth weight are the variables which best predict AOP in FEP. Stimulant drugs, which were mostly used together with cannabis and cocaine, were the only substances associated with an earlier AOP. CONCLUSIONS: Our findings are consistent with previous study results and underline the role of the prenatal period in the development of psychosis and the importance of careful monitoring of pregnancy and delivery, especially in cases with familial history.

Evaluation of the elastic behaviour of central venous PVC, polyurethane and silicone catheters.

Eighty used and 20 new silicone, polyurethane and polyvinylchloride central venous catheters were tested to establish the Young's modulus and the bending stiffness of the catheters and their introducers. The catheters were subjected to longitudinal traction forces and their lengthening measured. Young's modulus and the geometric moment of inertia were then calculated. It is shown that polyurethane catheters show least variation in their elastic characteristics, and that silicone catheters offer least resistance to bending and do not change their elastic properties after use. All catheters were equally unlikely to cause thrombus production if this is related to excessive bending stiffness.

Shear stress synergism index and relative thixotropic area.

Shear stress synergism index and relative thixotropic area are introduced as quantifiers of viscous synergism and comparative thixotropy. The utility of these terms is demonstrated by their application to microcrystalline cellulose-sodium carboxymethyl cellulose (MCC-NaCMC) hydrogel, a starch of different botanical origins hydrogels and their combinations.

Thixotropy of highly viscous sodium (carboxymethyl)cellulose hydrogels.

A general method to quantify the thixotropic behavior of systems with very low thixotropy is proposed. The areas enclosed by the rheograms tau = f(gamma) must be fitted to functions with well-determined boundary conditions. From these equations the corresponding thixotropic areas are obtained, together with the theoretical area enclosed by the rheogram corresponding to the maximum rheodestruction. The proposed method is applied to high viscosity sodium (carboxymethyl)cellulose gels.

A time-dependent expression for thixotropic areas. Application to aerosil 200 hydrogels.

Experimental determination of the areas enclosed under the up curve, sigma = sigma(;gamma), corresponding to time zero, and the down curve, which would be obtained following complete rheodestruction of the system structure, is not an easy matter. In the present study a semi-empirical procedure for calculating the hypothetical values of these parameters is proposed. With these parameters it is possible to obtain a time-dependent expression for the thixotropic areas, S(T). This procedure has been applied to the study of the thixotropic behavior of Aerosil 200 hydrogels at different concentrations. The comparative analysis of these systems has been realized by studying the relative thixotropic areas and relative thixotropic rates that are obtained from S(T).

A simplified method for postmortem coronary angiography using gastrograffin.

OBJECTIVE: To assess the adequacy of perfusion of the heart at autopsy with a gastrograffin and dye mixture to obtain rapid postmortem angiograms while simultaneously documenting the vascular distribution of the myocardium. BACKGROUND: Postmortem coronary angiography is occasionally used in the evaluation of suspected cardiac deaths. Angiography provides legal documentation and can serve to guide subsequent cardiac dissection. Multiple techniques have been suggested in the literature for coronary angiography using infusion of radio-opaque silicone or gelatin. These techniques are cumbersome and require equipment generally not available in autopsy suites. METHODS: Following removal of the heart, a mixture of gastrograffin and colored dyes is injected into each coronary artery via a syringe. The coronary arteries are ligated and radiographs are obtained. After fixation, the heart is dissected in the usual manner. RESULTS: Adequate postmortem coronary angiograms are routinely obtained with this method. The coronary arterial distribution within the myocardium is easily documented at both the gross and microscopic levels because of the presence of differential coloration. CONCLUSIONS: The aforementioned technique using a gastrograffin and dye mixture provides a simplified approach to postmortem angiography. The novelty of the procedure stems from the low cost, ease of implementation, dual ability to assess vascular anatomy radiologically (gastrograffin), and gross distribution and histologic findings of dependent tissue using the light microscope (colored dye). This technique is inexpensive, rapid, and easily used, making it more suitable for general hospital practice and medical examiners' offices than previously described methods.

[Influence of blood pressure profile on erythropoietin levels in diabetics]. / Influence du profil tensionnel des diabétiques sur le taux d'érythropoïétine.

UNLABELLED: The purpose of this study was to investigate the relationships between 24-h BP profil and erythropoietin level in diabetics. PATIENTS AND METHODS: This study included 58 patients (26 women and 32 men, mean age: 58.7 +/- 14.6 yrs, diabetes duration: 16 +/- 11.2 yrs). Patients were divided by 24 hrs ABPM into 2 groups, one in which night-time pressures dipped by more than 10% (dippers, n = 16) and the other in which pressures dipped by less than 10% (non-dippers, n = 42) when compared to daytime pressures. Haemoglobin (Hb) and erythropoietin (EPO) levels where compared between diabetics and a control group (n = 110) and between dippers and non-dippers. RESULTS: Hb concentration of diabetics was significantly lower than those of control subjects (13.5 +/- 1.5 vs 14.5 +/- 1 g/dL; p < 0.0001) but EPO levels did not differ from significant manner between these two groups. EPO concentrations were lower in dippers than in control subjects (13.7 +/- 5.4 vs 17.9 +/- 5 mU/mL; p < 0.01), but there was not significant difference in Hb levels. Non-dippers had a Hb level lower than dippers (13.1 +/- 1.5 vs 14.6 +/- 1.1 g/dL, p < 0.0001), but EPO concentrations did not differ from significant manner. Hb was correlated with between daytime and night-time BP difference (SBP: r = 0.262; p < 0.05 and DBP: r = 0.396; p < 0.002). Hb was negatively correlated with albumin excretion rate (r = -0.335, p < 0.01) and with creatinine level (r = -0.419: p < 0.001). CONCLUSION: These data indicated that EPO production could be impaired in diabetics with abnormal diurnal BP variation. Nephropathy and cardiac autonomic dysfunction could explain these results.

[Transient polyuria in pregnancy in diabetes insipidus and gestational diabetes]. / Transiente Polyurie in der Schwangerschaft bei Diabetes insipidus und Gestationsdiabetes.

Two pregnant women developed overt polyuria (up to 11 l/day) and polydipsia during their second and third trimesters of pregnancy. In one patient hydronephrosis was present. Both patients suffered from mild gestational diabetes mellitus. Plasma sodium was 145 and 162 mmol/l. Polyuria and urinary hypo-osmolality responded well to desmopressin acetate. After delivery, polyuria and polydipsia disappeared in one patient and significantly improved in the other. Infusion of hypertonic saline one and two weeks respectively after delivery led to plasma hyper-osmolality (294 mosmol/kg and 305 mosmol/kg) without detectable stimulation of arginine vasopressin (AVP). Anterior pituitary function was normal. No stimulation of AVP occurred following insulin-induced hypoglycemia. AVP plasma disappearance after i.v. pulse injection of 1 microgram AVP as well as AVP plasma concentration after continuous infusion of 10 ng AVP/min was studied two weeks after delivery in one patient. The results suggested markedly elevated degradation of AVP compared to control subjects, probably due to an increased vasopressin activity. Eight months after delivery, hypertonic saline infusion in one patient led to a plasma-osmolality of 312 mosmol/kg without stimulation of AVP. In the second patient, AVP was not detectable (less than 0.2 pg/ml) six months after delivery when plasma osmolality was 290 mosmol/kg. Our studies demonstrate that a subclinical compensated diabetes insipidus was preexistent in both patients. Exacerbation occurred due to an increased AVP-clearance and presumably due to the hemodynamic and hormonal alterations during pregnancy, including a mild gestational diabetes mellitus.

The influence of polymer concentration on the 5-fluorouracil release rate from carbopol hydrogels.

5-Fluorouracil (5-FU) release kinetics from Carbopol 940 hydrogels prepared at pH 5.5 and five different polymer concentrations (0.0010, 0.0015, 0.0020, 0.0025 and 0.0030 w/w) were determined using Franz diffusion cells. Higuchi's equation for release from solutions was used to calculate the diffusion coefficients of 5-FU in the hydrogels. An empirical equation was obtained for the estimation of diffusivity of 5-FU as a function of polymer concentration, which from a practical view point can be considered useful in preformulation studies. Furthermore, the values of viscosity for all hydrogels assayed were determined. The diffusivity-viscosity relationship resembles the Stokes-Einstein equation for small solutes in liquid phases and provides a factor indicative of additional resistance offered by the gelling agent for drug diffusion.