La prueba de claudicación por rascado para diagnosticar lesiones de nervio periférico

Introducción: La prueba de claudicación por rascado es una prueba provocativa recientemente descrita para el diagnóstico de compresiones nerviosas periféricas

Método: El examinador se coloca sentado frente al paciente, primero sin provocar estimulo previo, y le intenta rotar internamente los hombros a lo que el paciente se resiste. Acto seguido se rasca la piel del paciente suavemente sobre el área de la compresión nerviosa, mientras el paciente se resiste a una rotación interna bilateral de los hombros con los codos flexionados, si el paciente tiene alodinia debido a una neuropatía compresiva, se obtiene una momentánea pérdida de la resistencia muscular.

Discusión: Los resultados obtenidos son en base a los sitios de compresión del nervio periférico, y son objetivos porque el examinador percibe el colapso del paciente

Conclusión: Esta prueba puede ser reproducida con facilidad una vez que se pase la curva de aprendizaje. Se esta trabajando en demostrar exactamente el mecanismo fisiológico de como funciona, y también se están analizando otras partes del cuerpo en donde se puede obtener el colapso.

Multiple sclerosis prevalence in Malaga, Southern Spain estimated by the capture–recapture method

Background: Although not definitively proven, there is commonly accepted to be a latitudinal gradient in the distribution of multiple sclerosis (MS), which is more frequent in temperate zones. The European Mediterranean countries are situated in a zone of median frequency, although ever increasing figures have been noted in the last decades.

Objective: The objective of this study was to assess the current prevalence rate of MS in the province of Malaga, Southern Spain.

Methods: The capture–recapture method (CRM) uses independent sources of data and permits the number of non-registered cases of a given disease to be estimated, and by doing so, to avoid ascertainment bias.

Results: Use of this method showed the estimated prevalence rate of MS in the province of Malaga, Southern Spain, to be 125/105 (95% confidence interval: 102/105–169/105), higher than the figures published previously.

Conclusions: Although we recognize that these data need to be confirmed in further studies and in other areas of the country using a similar method, we believe this study is the first to find such high figure of prevalence, being very similar to the figures reported in recent years in other southern European countries.

Usefulness of endoscopic ultrasonography in preoperative gastric cancer staging: diagnostic yield and therapeutic impact

OBJECTIVES

To evaluate the diagnostic yield of endoscopic ultrasonography in loco-regional staging of gastric cancer in our medium and to determine the impact of this technique on later therapeutic management.

MATERIAL AND METHODS

This is a retrospective study carried out on patients histologically diagnosed with gastric adenocarcinoma who had been referred for endoscopic ultrasonographic examination. The technique results were compared with those obtained from surgical samples and/or from exploratory laparoscopy- laparotomy. We compared the initial therapeutic decision based on conventional diagnostic techniques with the final therapeutic management based on the endoscopic ultrasonography results.

RESULTS

Forty-six patients with gastric adenocarcinoma were included in the study (a reference exploration was available in 36 cases). Diagnostic precision was 70% in stage T, while in stages T1, T2, T3 y T4 was 100, 38, 82, and 100%, respectively. The sensitivity and specificity to differentiate T1-2 from T3-4 was 94 and 85%, respectively. We could not identify factors associated with obtaining a correct diagnosis in staging T. Diagnostic precision was 72% for stage N (N0: 58%; Nx 88%). The presence of free perigastric fluid was identified in 7 cases; the presence of peritoneal carcinomatosis was later confirmed in 5 of these. The result of endoscopic ultrasonography led to a modification in the subsequent therapeutic management in 13 patients (28%).

CONCLUSIONS

Endoscopic ultrasonography is a useful technique for loco-regional staging of gastric adenocarcinoma, which may have important implications in the therapeutic management of these patients.

Prediction and verification of possible reef-fish spawning aggregation sites in Los Roques Archipelago National Park, Venezuela

This study attempts to predict and verify possible spawning aggregation sites and times in the Los Roques Archipelago National Park, Venezuela, based on physical reef characteristics and the knowledge of experienced local fishermen. Three possible aggregation sites were selected for monitoring based on satellite images, low-cost bathymetric mapping and interviews with experienced local fishermen. Abundances and sizes of 18 species that are known to form reproductive aggregations were monitored at these sites using underwater visual census for 7 days after each full moon from February to August, 2007. While spawning events were not observed, possible indirect evidence of spawning aggregations was found for Lutjanus analis at Cayo Sal and Boca de Sebastopol, Lutjanus apodus at Cayo Sal, Lutjanus cyanopterus at Cayo Sal and Piedra La Guasa and Epinephelus guttatus at Bajo California and Cayo de Agua. Additionally, indirect evidence was identified for the past existence of a spawning aggregation of Epinephelus striatus in the northern part of the archipelago, which may have been eliminated by overfishing c.15 years ago. Bathymetric mapping showed that the shelf edge at sites monitored in this study was shallower than at spawning aggregation sites in other parts of the Caribbean, and that sites were not proximal to deep water. While this study does not prove the existence or locations of spawning aggregations of reef fishes in the archipelago, it does add insight to a growing understanding of generalities in the relationship between seafloor characteristics and the locations of transient reef-fish spawning aggregations in the Caribbean.

Characterization of the inhibitory roles of RFRP3, the mammalian ortholog of GnIH, in the control of gonadotropin secretion in the rat: in vivo and in vitro studies

RF-amide related peptides (RFRP), as putative mammalian orthologs of the avian gonadotropin-inhibitory hormone (GnIH), have been proposed as key regulators of gonadotropin secretion in higher vertebrates. Yet considerable debate has arisen recently on their physiological relevance and potential mechanisms and sites of action. Present studies were undertaken to further characterize the effects of RFRP on LH and FSH secretion by a combination of in vivo and in vitro approaches in male and female rats. Initial screening via intracerebroventricular (icv) administration of different analogs of RFRP1 (RFRP1-12 and RFRP1-20) and RFRP3 (RFRP3-8 and RFRP3-17), as well as the related neuropeptide FF (NPFF8), to gonadectomized (GNX) female rats evidenced significant, albeit modest, inhibitory effects on LH secretion only for RFRP3-8 and RFRP3-17, which were detectable at the high dose rage (1 nmol for RFRP3-8, 5 nmol for RFRP3-17). This moderate inhibitory action was also documented after icv administration of RFRP3-8 to intact and GNX male rats. In addition, systemic (intravenous) administration of RFRP3-8 decreased the circulating levels of both gonadotropins in GNX male rats. Likewise, RFRP3-8 inhibited basal and GnRH-stimulated LH secretion by pituitaries from GNX males in vitro. This inhibitory effect was blocked by the antagonist of RFRP receptors, RF9. In summary, our results support a putative inhibitory role of RFRP3 as ortholog of GnIH in the regulation of gonadotropin secretion in mammals, which appears to involve direct pituitary actions as well as potential central (hypothalamic) effects.

Acute inflammation reduces kisspeptin immunoreactivity at the arcuate nucleus and decreases responsiveness to kisspeptin independently of its anorectic effects

Severe inflammatory challenges are frequently coupled to decreased food intake and disruption of reproductive function, the latter via deregulation of different signaling pathways that impinge onto GnRH neurons. Recently, the hypothalamic Kiss1 system, a major gatekeeper of GnRH function, was suggested as potential target for transmitting immune-mediated repression of the gonadotropic axis during acute inflammation, and yet key facets of such a phenomenon remain ill defined. Using lipopolysaccharide S (LPS)-treated male rats as model of inflammation, we document herein the pattern of hypothalamic kisspeptin immunoreactivity (IR) and hormonal responses to kisspeptin during the acute inflammatory phase. LPS injections induced a dramatic but transient drop of serum LH and testosterone levels. Suppression of gonadotropic function was associated with a significant decrease in kisspeptin-IR in the arcuate nucleus (ARC) that was not observed under conditions of metabolic stress induced by 48-h fasting. In addition, absolute responses to kisspeptin-10 (Kp-10), in terms of LH and testosterone secretion, were significantly attenuated in LPS-treated males that also displayed a decrease in food intake and body weight. Yet pair-fed males did not show similar alterations in LH and testosterone secretory responses to Kp-10, whose magnitude was preserved, if not augmented, during food restriction. In summary, our data document the impact of acute inflammation on kisspeptin content at the ARC as key center for the neuroendocrine control of reproduction. Our results also suggest that suppressed gonadotropic function following inflammatory challenges might involve a reduction in absolute responsiveness to kisspeptin that is independent of the anorectic effects of inflammation.

Characterization of the potent gonadotropin-releasing activity of RF9, a selective antagonist of RF-amide-related peptides and neuropeptide FF receptors: physiological and pharmacological implications

Identification of RF-amide-related peptides (RFRP), as putative mammalian orthologs of the avian gonadotropin-inhibitory hormone, has drawn considerable interest on its potential effects and mechanisms of action in the control of gonadotropin secretion in higher vertebrates. Yet, these analyses have so far relied mostly on indirect approaches, while direct assessment of their physiological roles has been hampered by the lack of suitable antagonists. RF9 was recently reported as a selective and potent antagonist of the receptors for RFRP (RFRPR) and the related neuropeptides, neuropeptide FF (NPFF) and neuropeptide AF (NPFF receptor). We show here that RF9 possesses very strong gonadotropin-releasing activities in vivo. Central administration of RF9 evoked a dose-dependent increase of LH and FSH levels in adult male and female rats. Similarly, male and female mice responded to intracerebroventricular injection of RF9 with robust LH secretory bursts. In rats, administration of RF9 further augmented the gonadotropin-releasing effects of kisspeptin, and its stimulatory effects were detected despite the prevailing suppression of gonadotropin secretion by testosterone or estradiol. In fact, blockade of estrogen receptor-alpha partially attenuated gonadotropin responses to RF9. Finally, systemic administration of RF9 modestly stimulated LH secretion in vivo, although no direct effects in terms of gonadotropin secretion were detected at the pituitary in vitro. Altogether, these data are the first to disclose the potent gonadotropin-releasing activity of RF9, a selective antagonist of RFRP (and NPFF) receptors. Our findings support a putative role of the RFRP/gonadotropin-inhibitory hormone system in the central control of gonadotropin secretion in mammals and have interesting implications concerning the potential therapeutic indications and pharmacological effects of RF9.

Analysis of the HLA population data (AHPD) submitted to the 15th International Histocompatibility/Immunogenetics Workshop by using the Gene[rate] computer tools accommodating ambiguous data (AHPD project report)

During the 15th International Histocompatibility and Immunogenetics Workshop (IHIWS), 14 human leukocyte antigen (HLA) laboratories participated in the Analysis of HLA Population Data (AHPD) project where 18 new population samples were analyzed statistically and compared with data available from previous workshops. To that aim, an original methodology was developed and used (i) to estimate frequencies by taking into account ambiguous genotypic data, (ii) to test for Hardy-Weinberg equilibrium (HWE) by using a nested likelihood ratio test involving a parameter accounting for HWE deviations, (iii) to test for selective neutrality by using a resampling algorithm, and (iv) to provide explicit graphical representations including allele frequencies and basic statistics for each series of data. A total of 66 data series (1-7 loci per population) were analyzed with this standard approach. Frequency estimates were compliant with HWE in all but one population of mixed stem cell donors. Neutrality testing confirmed the observation of heterozygote excess at all HLA loci, although a significant deviation was established in only a few cases. Population comparisons showed that HLA genetic patterns were mostly shaped by geographic and/or linguistic differentiations in Africa and Europe, but not in America where both genetic drift in isolated populations and gene flow in admixed populations led to a more complex genetic structure. Overall, a fruitful collaboration between HLA typing laboratories and population geneticists allowed finding useful solutions to the problem of estimating gene frequencies and testing basic population diversity statistics on highly complex HLA data (high numbers of alleles and ambiguities), with promising applications in either anthropological, epidemiological, or transplantation studies.

Critical roles of kisspeptins in female puberty and preovulatory gonadotropin surges as revealed by a novel antagonist

Kisspeptins (Kp) have recently emerged as master regulators of the reproductive axis and among the most potent elicitors of GnRH-gonadotropin secretion. Despite their paramount importance in reproductive physiology and their potential therapeutic implications, development of Kp antagonists has remained elusive, and only recently has the first compound with the ability to block Kp actions in vitro and in vivo, namely p234, been reported. However, previous in vivo studies all used acute central injections, whereas characterization of the effects of the antagonist after continuous or systemic administration, which poses pharmacological challenges, is still pending. We report herein a comprehensive series of analyses on the impact of continuous intracerebroventricular infusion of p234 on puberty onset and the preovulatory surge of gonadotropins in the female rat. In addition, the effects of systemic (ip) administration of a tagged p234-penetratin, with a predicted higher permeability at the blood-brain barrier, on Kp-10 induced gonadotropin secretion were evaluated. Central infusion of p234 to pubertal females delayed vaginal opening and decreased uterine and ovarian weights at the expected time of puberty, without affecting body weight. Likewise, chronic intracerebroventricular administration of p234 for 4 d prevented the preovulatory surges of LH and FSH. In addition, systemic (ip) administration of p234-penetratin significantly attenuated acute LH and FSH responses to Kp-10, either after intracerebroventricular or ip injection of Kp. Our data document the validity of p234 for antagonizing Kp actions in vivo and provide direct experimental evidence for the important role of Kp signaling in the key events of female reproduction, such as puberty onset and the preovulatory surge of gonadotropins.

Gestational sac volume: comparison between SonoAVC and VOCAL measurements at 11 + 0 to 13 + 6 weeks of gestation

OBJECTIVES

To assess the novel three-dimensional (3D) tool, Sonography-based Automated Volume Count (SonoAVC) in the calculation of gestational sac volume at 11 + 0 to 13 + 6 weeks of gestation, to correlate the measurements with those obtained using Virtual Organ Computed-aided AnaLysis (VOCAL) and to study the reproducibility of SonoAVC volume calculation of this irregularly shaped structure.

METHODS

We acquired 3D volumes of the uterus in 65 pregnancies at 11 + 0 to 13 + 6 weeks of gestation. We performed volume calculation of the gestational sac, excluding the fetus and the placenta, using VOCAL with 15 degrees 12-step rotation. We then repeated the calculation with three different SonoAVC settings and compared both techniques. In 30 cases we assessed the reproducibility of the SonoAVC volume calculations.

RESULTS

In 95% of cases it was possible to calculate the gestational sac volume with SonoAVC. This volume increased with advancing gestation and the volumes were expressed as delta values to compare the measurements made with VOCAL and the three different SonoAVC settings. There was no difference between delta values of gestational sac volume calculated using VOCAL and SonoAVC with high and medium growth settings. Reproducibility analysis showed good results.

CONCLUSION

Gestational sac volume calculation is feasible with SonoAVC in most cases and does not differ from that performed using VOCAL. High and medium growth SonoAVC settings seem to be more accurate for gestational sac volume calculation, although larger studies are required for standardization of the technique. The reproducibility analysis showed similar results to those previously published.

Liver fibrosis in patients with chronic hepatitis C and persistently normal liver enzymes: influence of HIV infection

Liver fibrosis progress slowly in patients with chronic hepatitis C and persistently normal alanine aminotransferase (PNALT) compared to subjects with elevated aminotransferases. Differences in liver fibrosis according to human immunodeficiency virus (HIV) status in this population have not been examined. All patients with serum hepatitis C virus (HCV)-RNA and PNALT who underwent liver fibrosis assessment using elastometry since 2004 at three different European hospitals were evaluated. Patients previously treated with interferon were excluded. PNALT was defined as ALT below the upper limit of normality in at least three consecutive determinations within the last 12 months. Fibrosis stage was defined as mild (Metavir F0-F1) if stiffness < or =7.1 kPa; moderate (F2) if 7.2-9.4 kPa; severe (F3) if 9.5-14 kPa, and cirrhosis (F4) if >14 kPa. A total of 449 HIV-negative and 133 HIV-positive patients were evaluated. HIV-negative patients were older (mean age 51.8 vs 43.5 years) and more frequently females (63%vs 37%) than the HIV counterparts. Mean serum HCV-RNA was similar in both the groups (5.9 vs 5.8 log IU/mL). Overall, 78.8% of the HIV patients were on HAART and their mean CD4 count was 525 (+/-278) cells/microL. In HIV-negatives, liver fibrosis was mild in 84.6%; moderate in 8.7%, severe in 3.3% and cirrhosis was found in 3.3%. In HIV patients, these figures were 70.7%, 18.8%, 6%, and 4.5%, respectively. In the multivariate logistic regression analysis, older age (odds ratio or OR: 1.04; 95% confidence interval or CI: 1.02-1.07; P < 0.001) and being HIV+ (OR: 2.6; 95% CI: 1.21-5.85; P < 0.01) were associated with severe liver fibrosis or cirrhosis (F3-F4). Thus, severe liver fibrosis and cirrhosis are seen in 6.6% of the HCV-monoinfected and in 10.5% of HCV-HIV co-infected patients with PNALT. Some degree of liver fibrosis that justifies treatment is seen in 15% of the HCV-monoinfected but doubles to nearly 30% in HIV-HCV co-infected patients with PNALT.

The mammalian target of rapamycin as novel central regulator of puberty onset via modulation of hypothalamic Kiss1 system

The mammalian target of rapamycin (mTOR) is a serine/threonine kinase that operates as sensor of cellular energy status and effector for its coupling to cell growth and proliferation. At the hypothalamic arcuate nucleus, mTOR signaling has been recently proposed as transducer for leptin effects on energy homeostasis and food intake. However, whether central mTOR also participates in metabolic regulation of fertility remains unexplored. We provide herein evidence for the involvement of mTOR in the control of puberty onset and LH secretion, likely via modulation of hypothalamic expression of Kiss1. Acute activation of mTOR by l-leucine stimulated LH secretion in pubertal female rats, whereas chronic l-leucine infusion partially rescued the state of hypogonadotropism induced by food restriction. Conversely, blockade of central mTOR signaling by rapamycin caused inhibition of the gonadotropic axis at puberty, with significantly delayed vaginal opening, decreased LH and estradiol levels, and ovarian and uterine atrophy. Inactivation of mTOR also blunted the positive effects of leptin on puberty onset in food-restricted females. Yet the GnRH/LH system retained their ability to respond to ovariectomy and kisspeptin-10 after sustained blockade of mTOR, ruling out the possibility of unspecific disruption of GnRH function by rapamycin. Finally, mTOR inactivation evoked a significant decrease of Kiss1 expression at the hypothalamus, with dramatic suppression of Kiss1 mRNA levels at the arcuate nucleus. Altogether our results unveil the role of central mTOR signaling in the control of puberty onset and gonadotropin secretion, a phenomenon that involves the regulation of Kiss1 and may contribute to the functional coupling between energy balance and gonadal activation and function.

WHO global survey on maternal and perinatal health in Latin America: classifying caesarean sections

BACKGROUND

Caesarean section rates continue to increase worldwide with uncertain medical consequences. Auditing and analysing caesarean section rates and other perinatal outcomes in a reliable and continuous manner is critical for understanding reasons caesarean section changes over time.

METHODS

We analyzed data on 97,095 women delivering in 120 facilities in 8 countries, collected as part of the 2004-2005 Global Survey on Maternal and Perinatal Health in Latin America. The objective of this analysis was to test if the "10-group" or "Robson" classification could help identify which groups of women are contributing most to the high caesarean section rates in Latin America, and if it could provide information useful for health care providers in monitoring and planning effective actions to reduce these rates.

RESULTS

The overall rate of caesarean section was 35.4%. Women with single cephalic pregnancy at term without previous caesarean section who entered into labour spontaneously (groups 1 and 3) represented 60% of the total obstetric population. Although women with a term singleton cephalic pregnancy with a previous caesarean section (group 5) represented only 11.4% of the obstetric population, this group was the largest contributor to the overall caesarean section rate (26.7% of all the caesarean sections). The second and third largest contributors to the overall caesarean section rate were nulliparous women with single cephalic pregnancy at term either in spontaneous labour (group 1) or induced or delivered by caesarean section before labour (group 2), which were responsible for 18.3% and 15.3% of all caesarean deliveries, respectively.

CONCLUSION

The 10-group classification could be easily applied to a multicountry dataset without problems of inconsistencies or misclassification. Specific groups of women were clearly identified as the main contributors to the overall caesarean section rate. This classification could help health care providers to plan practical and effective actions targeting specific groups of women to improve maternal and perinatal care.