Spatio-temporal dynamics of dengue 2009 outbreak in Córdoba City, Argentina

During 2009 the biggest dengue epidemic to date occurred in Argentina, affecting almost half the country. We studied the spatio-temporal dynamics of the outbreak in the second most populated city of the country, Córdoba city. Confirmed cases and the results of an Aedes aegypti monitoring during the outbreak were geolocated. The imported cases began in January, and the autochthonous in March. Thirty-three percent of the 130 confirmed cases were imported, and occurred mainly at the center of the city. The autochthonous cases were more frequent in the outskirts, specially in the NE and SE. Aedes aegypti infestation showed no difference between neighborhoods with or without autochthonous cases, neither between neighborhoods with autochthonous vs. imported cases. The neighborhoods with imported cases presented higher population densities. The majority of autochthonous cases occurred at ages between 25 and 44 years old. Cases formed a spatio-temporal cluster of up to 20 days and 12km. According to a mathematical model that estimates the required number of days needed for transmission according to daily temperature, the number of cases begun to fall when more than 15.5 days were needed. This may be a coarse estimation of mean mosquito survival in the area, provided that the study area is close to the global distribution limit of the vector, and that cases prevalence was very low.

Dengue virus identification by transmission electron microscopy and molecular methods in fatal dengue hemorrhagic fever

Dengue virus is the most significant virus transmitted by arthropods worldwide and may cause a potentially fatal systemic disease named dengue hemorrhagic fever. In this work, dengue virus serotype 4 was detected in the tissues of one fatal dengue hemorrhagic fever case using electron immunomicroscopy and molecular methods. This is the first report of dengue virus polypeptides findings by electron immunomicroscopy in human samples. In addition, not-previously-documented virus-like particles visualized in spleen, hepatic, brain, and pulmonary tissues from a dengue case are discussed.

[Peritoneal strumosis: an extension study with (99m)Tc-pertecnectate]

We report the case of a 35-year-old nulliparous woman, with a previous history of ovarian cystectomy diagnosed 3 years earlier due a struma ovarii type of monodermal teratoma in the right ovary and a hemorrhagic cyst in the left ovary. Progressive growth of the left adnexal mass was observed in the periodic medical check-ups. Due to this, a second laparoscopy was performed and, based on the findings, a left ovarian cystectomy, right salpingectomy and resection of multiple peritoneal implants were carried out. The pathology diagnosis was left struma ovarii and peritoneal strumosis. A whole body and SPECT/CT scan with (99m)Tc-pertechnetate was performed to detect possible peritoneal implants. This study helped to make the therapeutic decision.

Detection of zoonotic intestinal parasites in public parks of Spain. Potential epidemiological role of microsporidia

Several studies have demonstrated that the soil of public parks presents an important source of infection which has a significant impact on public health. Children are the main group affected by accidentally ingestion of contaminated soil. This study was performed in order to identify the presence of zoonotic parasites in dog and cat faecal and soil samples from public parks of Madrid, Spain. Six hundred twenty-five and seventy-nine soil and faecal samples (presumably from dogs and cats) respectively were collected from 67 parks. Intestinal parasites were identified in 27 parks (40.3%), which were contamined with Giardia sp. (19.4%), microsporidia (19.4%), Toxocara spp. (16.4%), Cryptosporidium sp. (6%), Entamoeba histolytica (3%) and Ancylostomidae (3%). Combinations of two or more intestinal parasites were found in 11 parks, and it was common to find Giardia and microsporidia together in samples. Intestinal parasites were detected in 18% (112/625) of soil samples. The most frequent parasite species found in the examined soil samples were Toxocara spp. (16.4%), followed by Giardia sp. (4.5%) and Strongyloides sp. larvae (3%). The zoonotic parasites found in the 79 faecal samples were Giardia sp. (17.7%), Cryptosporidium sp. (9%), E. histolytica (2.5%), Trichuris vulpis (1.3%), Toxascaris leonina (1.3%) and microsporidia spores (28%). Microsporidia characterization by amplification of DNA confirmed 10 samples as positive, eight for E. bieneusi and two for E. hellem by PCR. The role of those parasites in the environment are discussed.

Portosystemic hepatic encephalopathy model shows reversal learning impairment and dysfunction of neural activity in the prefrontal cortex and regions involved in motivated behavior

Hepatic encephalopathy (HE) is a neurological complication that affects attention and memory. Experimental animal models have been used to study HE, the most frequent being the portacaval shunt (PCS). In order to investigate learning impairment and brain functional alterations in this model, we assessed reversal learning and neural metabolic activity in a PCS rat model. PCS and sham-operated rats were tested for reversal learning in the Morris water maze. Brains were then processed for cytochrome oxidase (CO) histochemistry. The PCS group had reversal learning impairment and a reduction in CO activity in the prefrontal cortex, ventral tegmental area and accumbens shell nucleus. These results suggest that this model of portosystemic HE shows learning impairments that could be linked to dysfunction in neural activity in the prefrontal cortex and regions involved in motivated behavior.

Improving use of resources-health care in patients with psychiatric pathology after introduction of risperidone long-acting injection (RLAI)

Enhance adherence to treatment is one of the main objectives in psychiatric clinical practice. The aim of this study is to evaluate changes in the use of oral antipsychotic medication, the use of rehabilitation resources and the number and duration of income in Psychiatric Inpatient Unit, comparing one year before and one year after RLAI's introduction, in patients with different psychiatric disorders, followed up by Mental Health Center and have maintained adherence to treatment for a defined period. We performed an observational, retrospective study by reviewing medical records of patients in ambulatory monitoring. The sample consisted of all patients (112) who had maintained RLAI treatment for a year, excluding those who did not fulfill the guideline correctly (14), remaining n = 98. We included patients of various pathologies, establishing groups as qualitative variables (F.20 = 56; F.25 = 12; F.22–28 = 20; F.60 = 10); of both sexes (V = 71; M = 27) and all ages. The preliminary results obtained showed a greater use of rehabilitation resources and decreased use of oral antipsychotics.

Raptor nest decorations are a reliable threat against conspecifics

Individual quality is often signaled by phenotypic flags, such as bright plumage patches in birds. Extended phenotype signals can similarly show quality, but in these cases the signals are external to the individual, often taking the form of objects scavenged from the environment. Through multiple manipulative experiments, we showed that objects used for nest decoration by a territorial raptor, the black kite (Milvus migrans), act as reliable threats to conspecifics, revealing the viability, territory quality, and conflict dominance of the signaler. Our results suggest that animal-built structures may serve as signaling devices much more frequently than currently recognized.

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.

Coping with uncertainty: breeding adjustments to an unpredictable environment in an opportunistic raptor

No environment is truly constant in time. As a result, animals have evolved multiple adjustments to cope with such fluctuations. However, the allocation of effort to costly activities that imply long-term commitments, such as breeding, may be extremely challenging when future resources change constantly and unpredictably, a context that has received little investigation. To fill this gap, we studied the breeding response by a wetland-dependent raptor, the black kite Milvus migrans, to within and between-years fluctuations in resource availability (inundation levels). The breeding performance of the population was decomposed into reproductive components expressed in a sequence of successive tasks along the breeding cycle (e.g. timing of laying, clutch size, hatching success, brood reduction). Variation in each component was related to resource levels observed at different key dates of the season in order to test whether and when population-level reproduction was adjusted to available resources. Along a 22-year time-series, inundation levels fluctuated unpredictably within and among years, and mostly affected the later components of kites' reproduction, such as hatching success and the incidence of brood reduction, which were the main determinants of the population yearly breeding output. Results were consistent with multiple adjustments to cope with uncertainty. As the season progressed and resources became easier to assess, a bet-hedging waiting strategy based on a conservatively small, invariant and asynchronous clutch gave way to real-time resource-tracking mechanisms mediated by progressive adjustments to current prey availability, so that population-level breeding rates were determined and tuned to resources rather late in the season. Such adjustments were the likely outcome of the interaction between parental tactics and environmental constraints. Behavioural flexibility, such as dietary opportunism, probably promoted further resistance to resource oscillations. Given that all ecosystems show some degree of unpredictability, resource-tracking adjustments, such as the ones depicted here, are likely to be commonplace in most communities.

Chronic liver disease and cirrhosis mortality and social deprivation: a spatial analysis in small areas of Madrid region

OBJECTIVES

To study census-tract distribution of chronic liver disease and cirrhosis mortality in the Madrid Region and its association with socio-economic deprivation.

METHODS

Cross-sectional, ecological (3906 census-tract) study, using mortality data for 1996-2003 and a deprivation index drawn up on the basis of 2001 census data. Standardised mortality ratios were calculated taking Spanish rates for 2001 as reference. Smoothed census-tract relative risks were computed using the Besag-York-Mollie model. Relative risks (RRs) of dying and their 95% credibility intervals (95% CIs) were calculated according to quartiles of the deprivation index (with the fourth quartile -Q- of the indicator being the most unfavourable situation). Maps were plotted depicting the distribution of the posterior probability of RR > 1.

RESULTS

Census tracts with a high risk of mortality were detected, mostly located in the centre and on the eastern, south-eastern and south-western fringes of the city of Madrid. Mortality increased with deprivation. RRs of mortality according to quartíles of the deprivation index were: Q2 = 1.5 (CI: 1.3-1.6), Q3 = 1.9 (CI:1.7-2.2) and Q4 = 2.5 (CI:2.2-2.8) for men; and Q2 = 1.3 (CI:1.1-1.5), Q3 = 1.5 (CI:1.3-1.7) and Q4 = 1.6 (CI:1.3-1.8) for women.

CONCLUSIONS

This small-area study enabled census tracts with excess mortality eligible for a special public health intervention to be identified, and their association with socio-economic deprivation to be confirmed.

Census tract socioeconomic and physical environment and cardiovascular mortality in the Region of Madrid (Spain)

BACKGROUND

Features of the area might contribute to differences in cardiovascular mortality. The census tract distribution of ischaemic heart disease (IHD) and cerebrovascular disease mortality in the Region of Madrid and its association with deprivation and environmental variables were examined in this study.

METHODS

Cross-sectional, ecological study covering 3906 census tracts (median of around 1000 inhabitants), using mortality data (population aged <75 years) for 1996-2003, as well as socioeconomic deprivation and other environmental indicators (subjective perceptions of pollution, background noise, lack of green spaces and delinquency) drawn from the 2001 census. Standardised mortality ratios were calculated. Smoothed census tract relative risks were calculated using the Besag-York-Mollié model. Relative risks (RRs) of dying and their 95% credibility intervals (95% CI) were calculated according to the indicators considered (with the fourth quartile, Q, being the most unfavourable situation). Maps were plotted depicting the distribution of the posterior probability of RR>1.

RESULTS

Census tracts with excess mortality were mostly located in the city of Madrid. Mortality increased with deprivation: RRs of IHD and stroke mortality in Q4 with respect to Q1 were 1.42 (95% CI 1.31 to 1.54) and 1.66 (95% CI 1.45 to 1.88) for men, and 1.54 (95% CI 1.33 to 1.79) and 1.52 (95% CI 1.29 to 1.76) for women respectively. Associations with deprivation decreased only slightly when perceived lack of green spaces and delinquency were included in the model. In men, subjective perceptions of areas remained associated with cardiovascular mortality after adjustment for deprivation.

CONCLUSION

Deprivation and subjective perceptions of physical environmental characteristics are ecologically associated with cardiovascular disease mortality.

Effects of chronic exercise on myocardial refractoriness: a study on isolated rabbit heart

AIM

To determine whether chronic physical training increases atrial and ventricular refractoriness in isolated rabbit heart.

METHODS

Trained rabbits were submitted to a protocol of treadmill running. The electrophysiological parameters of refractoriness investigated in an isolated heart preparation were: (1) atrial effective refractory period (AERP) and atrial functional refractory period and ventricular effective and functional refractory periods (VERP and VFRP) using the extrastimulus technique at four different pacing cycle lengths; (2) the dominant frequency (DF) of ventricular fibrillation (VF). A multi-electrode plaque containing 256 electrodes and a spectral method were used to obtain the mean, maximum and minimum DF of VF. Sinus cycle length of the isolated hearts was determined as an electrophysiological parameter of training. In vivo heart rate, myocardial heat shock proteins (HSP60) and inducible nitric oxide synthase were also determined in some animals as electrophysiological and biochemical markers of training respectively.

RESULTS

VERP and VFRP were longer in the trained group than in the control group. The mean DF of VF was lower in the trained group than in the control group. Despite the fact that training did not significantly modify the AERP, it tended to be longer in the trained group (P = 0.09).

CONCLUSION

Training seems to increase the electrical stability of ventricular myocardium. As the electrophysiological modifications were exhibited in hearts not submitted to extrinsic nervous system or humoral influences, they are, at least in part, intrinsic modifications. These electrophysiological data also suggest that training could protect against reentrant ventricular arrhythmias.