Spatiotemporal dynamics of Ixodes ricinus abundance in northern Spain.

Ixodes ricinus is the most medically relevant tick species in Europe because it transmits the pathogens that cause Lyme borreliosis and tick-borne encephalitis. Northern Spain represents the southernmost margin of its main European range and has the highest rate of Lyme borreliosis hospitalisations in the country. Currently, the environmental determinants of the spatiotemporal patterns of I. ricinus abundance remain unknown in this region and these may differ from drivers in highly favourable areas for the species in Europe. Therefore, our study aimed to understand the main factors modulating questing I. ricinus population dynamics to map abundance patterns in northern Spain. From 2012 to 2014, monthly/fortnightly samplings were conducted at 13 sites in two regions of northern Spain to estimate spatiotemporal variation in I. ricinus questing abundance. Local abundance of I. ricinus was modelled in relation to variation in local biotic and abiotic environmental conditions by constructing generalised linear mixed models with a zero-inflated negative binomial distribution for overdispersed data. The different developmental stages of I. ricinus were most active at different times of the year. Adults and nymphs showed a peak of abundance in spring, while questing larvae were more frequent in summer. The main determinants affecting the spatiotemporal abundance of the different stages were related to humidity and temperature. For adults and larvae, summer seemed to be the most influential period for their abundance, while for nymphs, winter conditions and those of the preceding months seemed to be determining factors. The highest abundances of nymphs and adults were predicted for the regions of northern Spain with the highest rate of Lyme borreliosis hospitalisations. Our models could be the basis on which to build more accurate predictive models to identify the spatiotemporal windows of greatest potential interaction between animals/humans and I. ricinus that may lead to the transmission of I. ricinus-borne pathogens.

Integrative clinical, hormonal, and molecular data associate with invasiveness in acromegaly: REMAH study.

INTRODUCTION: Growth hormone (GH)-secreting pituitary tumors (GHomas) are the most common acromegaly cause. At diagnosis, most of them are macroadenomas, and up to 56% display cavernous sinus invasion. Biomarker assessment associated with tumor growth and invasion is important to optimize their management. OBJECTIVES: The study aims to identify clinical/hormonal/molecular biomarkers associated with tumor size and invasiveness in GHomas and to analyze the influence of pre-treatment with somatostatin analogs (SSAs) or dopamine agonists (DAs) in key molecular biomarker expression. METHODS: Clinical/analytical/radiological variables were evaluated in 192 patients from the REMAH study (ambispective multicenter post-surgery study of the Spanish Society of Endocrinology and Nutrition). The expression of somatostatin/ghrelin/dopamine system components and key pituitary/proliferation markers was evaluated in GHomas after the first surgery. Univariate/multivariate regression studies were performed to identify association between variables. RESULTS: Eighty percent of patients harbor macroadenomas (63.8% with extrasellar growth). Associations between larger and more invasive GHomas with younger age, visual abnormalities, higher IGF1 levels, extrasellar/suprasellar growth, and/or cavernous sinus invasion were found. Higher GH1 and lower PRL/POMC/CGA/AVPR1B/DRD2T/DRD2L expression levels (P < .05) were associated with tumor invasiveness. Least Absolute Shrinkage and Selection Operator's penalized regression identified combinations of clinical and molecular features with areas under the curve between 0.67 and 0.82. Pre-operative therapy with DA or SSAs did not alter the expression of any of the markers analyzed except for DRD1/AVPR1B (up-regulated with DA) and FSHB/CRHR1 (down-regulated with SSAs). CONCLUSIONS: A specific combination of clinical/analytical/molecular variables was found to be associated with tumor invasiveness and growth capacity in GHomas. Pre-treatment with first-line drugs for acromegaly did not significantly modify the expression of the most relevant biomarkers in our association model. These findings provide valuable insights for risk stratification and personalized management of GHomas.

Derived neutrophil-to-lymphocyte ratio (dNLR) as a diagnostic biomarker of pediatric acute appendicitis.

Appendicitis stands as the most common surgical emergency in pediatric populations. Despite the existence of numerous diagnostic biomarkers, their utility is constrained by limitations in cost-effectiveness, potentially leading to therapeutic delays. This research aims to determine the diagnostic accuracy of the derived neutrophil-to-lymphocyte ratio (dNLR) in appendicitis. Although its role in this context has been recently described, this is the first study to compare its performance against acute-phase reactants routinely employed in clinical practice. Following approval from the Research Committee (2023/390894), a diagnostic study was conducted including patients under 15 years old undergoing surgery for acute appendicitis (AA) and those presenting with non-surgical abdominal pain (AP).

Crimean-Congo haemorrhagic fever virus in questing non-Hyalomma spp. ticks in Northwest Spain, 2021.

Crimean-Congo haemorrhagic fever (CCHF) unexpectedly emerged in humans in Northwest Spain in 2021, and two additional cases were reported in the region in 2022. The 2021 case was associated with a tick bite on the outskirts of the city where the patient lived. PCR analysis of 95 questing ticks collected in the outskirts of that city in 2021, none of the genus Hyalomma, revealed a prevalence of confirmed CCHF virus (CCHFV) infection of 10.5%. Our results in this emerging scenario suggest the need to consider that CCHFV may be effectively spreading to Northwest Spain and to urgently understand any possible role of non-Hyalomma spp. ticks in the eco-epidemiological dynamics of CCHFV.

High response diversity and conspecific density-dependence, not species interactions, drive dynamics of coral reef fish communities.

Species-to-species and species-to-environment interactions are key drivers of community dynamics. Disentangling these drivers in species-rich assemblages is challenging due to the high number of potentially interacting species (the 'curse of dimensionality'). We develop a process-based model that quantifies how intraspecific and interspecific interactions, and species' covarying responses to environmental fluctuations, jointly drive community dynamics. We fit the model to reef fish abundance time series from 41 reefs of Australia's Great Barrier Reef. We found that fluctuating relative abundances are driven by species' heterogenous responses to environmental fluctuations, whereas interspecific interactions are negligible. Species differences in long-term average abundances are driven by interspecific variation in the magnitudes of both conspecific density-dependence and density-independent growth rates. This study introduces a novel approach to overcoming the curse of dimensionality, which reveals highly individualistic dynamics in coral reef fish communities that imply a high level of niche structure.

Animal Exposure Model for Mapping Crimean-Congo Hemorrhagic Fever Virus Emergence Risk.

To estimate the determinants of spatial variation in Crimean-Congo hemorrhagic fever virus (CCHFV) transmission and to create a risk map as a preventive public health tool, we designed a survey of small domestic ruminants in Andalusia, Spain. To assess CCHFV exposure spatial distribution, we analyzed serum from 2,440 sheep and goats by using a double-antigen ELISA and modeled exposure probability with environmental predictors by using generalized linear mixed models. CCHFV antibodies detected in 84 samples confirmed low CCHFV prevalence in small domestic ruminants in the region. The best-fitted statistical model indicated that the most significant predictors of virus exposure risk were cattle/horse density and the normalized difference vegetation index. Model validation showed 99.7% specificity and 10.2% sensitivity for identifying CCHFV circulation areas. To map CCHFV exposure risk, we projected the model at a 1 × 1-km spatial resolution. Our study provides insight into CCHFV ecology that is useful for preventing virus transmission.

Class A capsid assembly modulator apoptotic elimination of hepatocytes with high HBV core antigen level in vivo is dependent on de novo core protein translation.

Capsid assembly is critical in the hepatitis B virus (HBV) life cycle, mediated by the viral core protein. Capsid assembly is the target for new anti-viral therapeutics known as capsid assembly modulators (CAMs) of which the CAM-aberrant (CAM-A) class induces aberrant shaped core protein structures and leads to hepatocyte cell death. This study aimed to identify the mechanism of action of CAM-A modulators leading to HBV-infected hepatocyte elimination where CAM-A-mediated hepatitis B surface antigen (HBsAg) reduction was evaluated in a stable HBV replicating cell line and in AAV-HBV-transduced C57BL/6, C57BL/6 SCID, and HBV-infected chimeric mice with humanized livers. Results showed that in vivo treatment with CAM-A modulators induced pronounced reductions in hepatitis B e antigen (HBeAg) and HBsAg, associated with a transient alanine amino transferase (ALT) increase. Both HBsAg and HBeAg reductions and ALT increase were delayed in C57BL/6 SCID and chimeric mice, suggesting that adaptive immune responses may indirectly contribute. However, CD8+ T cell depletion in transduced wild-type mice did not impact antigen reduction, indicating that CD8+ T cell responses are not essential. Transient ALT elevation in AAV-HBV-transduced mice coincided with a transient increase in endoplasmic reticulum stress and apoptosis markers, followed by detection of a proliferation marker. Microarray data revealed antigen presentation pathway (major histocompatibility complex class I molecules) upregulation, overlapping with the apoptosis. Combination treatment with HBV-specific siRNA demonstrated that CAM-A-mediated HBsAg reduction is dependent on de novo core protein translation. To conclude, CAM-A treatment eradicates HBV-infected hepatocytes with high core protein levels through the induction of apoptosis, which can be a promising approach as part of a regimen to achieve functional cure. IMPORTANCE: Treatment with hepatitis B virus (HBV) capsid assembly modulators that induce the formation of aberrant HBV core protein structures (CAM-A) leads to programmed cell death, apoptosis, of HBV-infected hepatocytes and subsequent reduction of HBV antigens, which differentiates CAM-A from other CAMs. The effect is dependent on the de novo synthesis and high levels of core protein.

The influence of resolution on the predictive power of spatial heterogeneity measures as biomarkers of liver fibrosis.

Spatial heterogeneity of cells in liver biopsies can be used as biomarker for disease severity of patients. This heterogeneity can be quantified by non-parametric statistics of point pattern data, which make use of an aggregation of the point locations. The method and scale of aggregation are usually chosen ad hoc, despite values of the aforementioned statistics being heavily dependent on them. Moreover, in the context of measuring heterogeneity, increasing spatial resolution will not endlessly provide more accuracy. The question then becomes how changes in resolution influence heterogeneity indicators, and subsequently how they influence their predictive abilities. In this paper, cell level data of liver biopsy tissue taken from chronic Hepatitis B patients is used to analyze this issue. Firstly, Morisita-Horn indices, Shannon indices and Getis-Ord statistics were evaluated as heterogeneity indicators of different types of cells, using multiple resolutions. Secondly, the effect of resolution on the predictive performance of the indices in an ordinal regression model was investigated, as well as their importance in the model. A simulation study was subsequently performed to validate the aforementioned methods. In general, for specific heterogeneity indicators, a downward trend in predictive performance could be observed. While for local measures of heterogeneity a smaller grid-size is outperforming, global measures have a better performance with medium-sized grids. In addition, the use of both local and global measures of heterogeneity is recommended to improve the predictive performance.

Usefulness of cell ratios and the derived neutrophil-to-lymphocyte ratio in the diagnosis of pediatric acute appendicitis. / Utilidad de los índices celulares y el índice neutrófilo/linfocito derivado en el diagnóstico de la apendicitis aguda pediátrica.

OBJECTIVE: To analyze the accuracy of cell ratios in the diagnosis of pediatric acute appendicitis while introducing a new one -the derived neutrophil-to-lymphocyte ratio (dNLR). MATERIALS AND METHODS: An observational, retrospective study of patients aged 0-15 years old diagnosed with acute appendicitis (AA) and with non-surgical abdominal pain (AP) treated in our institution from 2021 to 2022 was carried out. The neutrophil-to-lymphocyte ratio (NLR), monocyte-to-lymphocyte ratio (MLR), platelet-to-lymphocyte ratio (PLR), and dNLR were compared between groups. RESULTS: 98 AA patients (30% of whom were female; age: 10 ± 3.3 years) and 97 AP patients (53% of whom were male; age: 9.3 ± 3.7 years) were included. NLR, MLR, PLR, and dNLR values were higher in AA patients than in AP patients: 9.6 IQR (interquartile range) 9.5 vs. 3.3 IQR 5.3: p< 0.0001; 0.7 IQR 0.6 vs. 0.46 IQR 0.7: p< 0.023; 199.8 IQR 163.9 vs. 134.0 IQR 129.2: p< 0.0001; and 5.29 IQR 3.9 vs. 2.39 IQR 2.7; p< 0.0001, respectively. Sensitivity, specificity, positive-negative predictive value, area under the ROC curve, and dNLR cut-off point for AA diagnosis were 70%, 78%, 77-72%, 0.811, and 3.98, respectively. CONCLUSIONS: Cell ratios are useful and cost-effective inflammatory parameters in the diagnosis of pediatric acute appendicitis. The results of this study suggest dNLR has the greatest clinical accuracy.

OBJETIVOS: Analizar la precisión de los índices celulares en el diagnóstico de la apendicitis aguda pediátrica, introduciendo uno nuevo, el índice neutrófilo/linfocito derivado (INLd). MATERIAL Y METODOS: Estudio retrospectivo observacional de los pacientes de 0-15 años diagnosticados de apendicitis aguda (AA) y con dolor abdominal no quirúrgico (DA) tratados en nuestro centro entre 2021-2022. Se comparó el índice neutrófilo/linfocito (INL), índice monocito/linfocito (IML), índice plaqueta/linfocito (IPL) y el INLd entre los grupos. RESULTADOS: Se incluyeron 98 casos con AA (30% mujeres, edad 10 ± 3,3 años) y 97 pacientes con DA (53% hombres, edad 9,3 ± 3,7 años). Los valores de INL, IML, IPL e INLd fueron mayores en pacientes con AA respecto a niños con DA: 9,6 rango intercuartil (RIC) 9,5 vs. 3,3 RIC 5,3: p< 0,0001; 0,7 RIC 0,6 vs. 0,46 RIC 0,7: p< 0,023; 199,8 RIC 163,9 vs. 134,0 RIC 129,2: p< 0,0001; y 5,29 RIC 3,9 vs. 2,39 RIC 2,7: p< 0,0001; respectivamente. La sensibilidad, especificidad, valor predictivo positivo-negativo, área bajo la curva ROC y el punto de corte del INLd para el diagnóstico de AA fue de 70%, 78%, 77-72%, 0,811 y 3,98; respectivamente. CONCLUSIONES: Los índices celulares son parámetros inflamatorios útiles y coste-efectivos que pueden contribuir al diagnóstico de la apendicitis aguda pediátrica. Los resultados de este estudio sugieren que el INLd es el de mayor precisión clínica.

Infrequent associations of cutis marmorata telangiectatica congenita: a two-case report. / Asociaciones infrecuentes de la cutis marmorata telangiectásica congénita: reporte de dos casos.

INTRODUCTION: Cutis marmorata telangiectatica congenita (CMTC) is a rare capillary malformation characterized by persistent reticular and violaceous erythema. We present two cases of CMTC. CLINICAL OBSERVATION: The first case involved a 13-month-old male with a reticular violaceous macule on the left gluteal region and a brownish papule with Darier's sign on the inner malleolus of the left foot, which was biopsied, revealing > 15 mast cells per field, leading to a diagnosis of CMTC and solitary cutaneous mastocytoma. The second case involved a newborn with a characteristic CMTC lesion without other malformations at birth, who subsequently developed two cutaneous tumors consistent with infantile hemangiomas during follow-up. DISCUSSION: CMTC is a benign condition. However, approximately 50% of cases exhibit associated anomalies. When CMTC is suspected, musculoskeletal, ophthalmological, and cutaneous malformations should be ruled out. To the best of our knowledge, this is the first report of CMTC associated with mastocytoma and one of the few cases associated with infantile hemangioma.

INTRODUCCION: La cutis marmorata telangiectásica congénita (CMTC) es una rara malformación capilar caracterizada por eritema reticular y violáceo persistente. Presentamos dos casos de CMTC. OBSERVACION CLINICA: Un varón de 13 meses presentaba una mácula violácea reticular en glúteo izquierdo y una pápula parduzca con signo de Darier en el maléolo interno del pie izquierdo, que fue biopsiada identificando > 15 mastocitos/campo, con lo cual se diagnosticó de CMTC y mastocitoma cutáneo solitario. El segundo caso, una recién nacida con una lesión característica de CMTC sin otras malformaciones al nacer, que durante el seguimiento desarrolló dos tumoraciones cutáneas compatibles con hemangiomas infantiles. COMENTARIOS: La CMTC es una condición benigna, sin embargo, aproximadamente el 50% de los casos presentan anomalías asociadas. Ante la sospecha de CMTC se deben descartar malformaciones musculoesqueléticas, oftalmológicas y cutáneas. Hasta donde tenemos conocimiento, este es el primer reporte de CMTC asociada con mastocitoma y uno de los pocos con hemangioma infantil.

Wet anaerobic digestion of organic fraction of municipal solid waste: experience with long-term pilot plant operation and industrial scale-up.

This paper presents the analysis of a pilot anaerobic digestion plant that operates with organic fraction of municipal solid waste (OFMSW) from a wholesale market and can treat up to 500 kg d-1. The process was monitored for a period of 524 days during which the residue was characterized and the biogas production and methane content were recorded. The organic load rate (OLR) of volatile solids (VS) was 0.89 kg m-3 d-1 and the Hydraulic Retention Time (HRT) was 25 d during the process. The yield was 82 Nm3 tons OFMSW-1 biogas, equivalent to 586 Nm3 tons CH4 VS-1. The results obtained in the pilot plant were used to carry out a technical-economic evaluation of a plant that treats 50 tons of OFMSW from wholesale markets. A production of 3769 Nm3 d-1 of biogas and 2080 Nm3 d-1 of methane is estimated, generating 35.1 MWh d-1 when converted to electricity.

Lymphatic Malformations in Parkes Weber's Syndrome: Retrospective Review of 16 Cases in a Vascular Anomalies Center.

INTRODUCTION: Parkes Weber's syndrome (PWS) is a rare genetic disorder characterized by overgrowth and vascular malformations, primarily affecting the extremities. While PWS is known to be associated with arteriovenous and capillary malformations, the potential involvement of lymphatic malformations (LMs) has not been previously reported. The objective of this study is to investigate the presence of lymphatic anomalies in PWS patients and their role in the development of limb asymmetry. MATERIALS AND METHODS: This is a retrospective study of patients diagnosed with PWS in a Vascular Anomalies Center from 1994 to 2020. Clinical data were obtained from medical records including diagnostic imaging, lymphoscintigraphy, and genetic testing. The Institutional Review Board and Ethics Committee have approved this study. RESULTS: A total of 16 patients aged 18 interquartile range 14.7 years diagnosed with PWS were included (50% female). Six of the 16 patients with PWS had clinical and imaging data suggestive of LM (37.5%) and 3 of them had genetic variants in RASA1 (2/3) or KRAS (1/3). Limb asymmetry was greater in patients with isolated PWS (2.6 ± 0.8 cm) than in the PWS-lymphatic anomalies population (2 ± 0.7 cm), although not significant (p = 0.247). One in 6 patients with PWS-LM required amputation (16.6%) versus 1 in 10 in isolated PWS (10%). CONCLUSION: Lymphatic anomalies may be present in a significant number of patients with PWS and could have a role in limb asymmetry and outcomes. It is paramount to investigate their existence and distinguish them from true overgrowth.

Risk factors for sequelae after surgery for lymphatic malformations in children.

OBJECTIVE: The first-line treatment of lymphatic malformations (LMs) is pharmacological or interventional; however, surgery is still necessary in selected cases. Our aim was to identify factors associated with the occurrence of permanent postoperative complications. METHODS: This was a case series study of children operated on for LMs between 2001 and 2021 and followed-up in our institution. Patients who presented sequelae derived from surgical treatment (cases) and those who did not (controls) were compared. RESULTS: We included 112 children who underwent surgery for LMs in different centers. Forty-nine cases and 63 controls were included (58% male), with a mean age of 34 months. Patients younger than 1 year presented more complications than older children, 59% (n = 29/49) vs 41% (n = 24/49), respectively (P = .02). LMs were in the cervicofacial region in seven patients in the control group compared with 30 of the cases (P ≤ .001), with microcystic malformations the most associated with sequelae (n = 11/15; P = .019). Concerning permanent complications, 88% were neurological (n = 43/49), mainly peripheral facial palsy (n = 17). There was greater postoperative residual disease in controls compared with cases (65% vs 14%, respectively; P ≤ .0001). However, following a second procedure in the control group, there was no significant difference in long-term cure rates (P = .38). CONCLUSIONS: The risk of sequelae following surgery for LM increases significantly in patients younger than 12 months in cervicofacial and microcystic malformations. Because non-radical resections are associated with fewer complications and an optimal long-term cure rate, we consider that aggressive surgical approaches should be avoided if the absence of sequelae is not guaranteed.

Testing the efficiency of capture methods for questing Hyalomma lusitanicum (Acari: Ixodidae), a vector of Crimean-Congo hemorrhagic fever virus.

Available methods to census exophilic tick populations have limitations in estimating true population size due to their inability to capture a high proportion of the actual tick population. We currently ignore the efficacy of these methods to capture questing Hyalomma spp. ticks, vectors of the Crimean-Congo hemorrhagic fever virus. To address the need of accurately estimating questing densities of Hyalomma spp., we designed a field experiment to test the efficacy of blanket dragging, blanket flagging, CO2-baited traps, and an ad hoc designed method, absolute surface counts, in capturing adult Hyalomma lusitanicum ticks from known numbers of preset fluorescent-marked ticks. The experiment was designed in 2 stages to estimate the point (1-day sampling) and cumulative (3-day serial sampling) efficacy of the methods under varying sampling effort and habitat. Tick survival, host interference, and weather effects on efficacy were controlled for in multiple regression models. There was high variability in method efficacy for capturing ticks, which was also modulated by effort, habitat, tick density, hosts, and soil temperature. The most effective method was absolute surface counts for both point estimates (39%) and cumulative efficacy (83%). CO2-baited traps reached a maximum efficacy of 37%, while blanket dragging and blanket flagging captured a maximum of the 8% of the marked ticks. Our results reveal the strengths and weaknesses of the different tick capture methods applied to adult H. lusitanicum and lay the groundwork for more accurate inferences about the true size of exophilic tick populations.

Mapping the risk of exposure to Crimean-Congo haemorrhagic fever virus in the Iberian Peninsula using Eurasian wild boar (Sus scrofa) as a model.

Crimean-Congo haemorrhagic fever (CCHF) virus (CCHFV) is a tick-borne zoonotic pathogen that can cause a lethal haemorrhagic disease in humans. Although the virus appears to be endemically established in the Iberian Peninsula, CCHF is an emerging disease in Spain. Clinical signs of CCHFV infection are mainly manifested in humans, but the virus replicates in several animal species. Understanding the determinants of CCHFV exposure risk from animal models is essential to predicting high-risk exposure hotspots for public health action. With this objective in mind, we designed a cross-sectional study of Eurasian wild boar (Sus scrofa) in Spain and Portugal. The study analysed 5,291 sera collected between 2006 and 2022 from 90 wild boar populations with a specific double-antigen ELISA to estimate CCHFV serum prevalence and identify the main determinants of exposure probability. To do so, we statistically modelled exposure risk with host- and environment-related predictors and spatially projected it at a 10 × 10 km square resolution at the scale of the Iberian Peninsula to map foci of infection risk. Fifty-seven (63.3 %) of the 90 populations had at least one seropositive animal, with seroprevalence ranging from 0.0 to 88.2 %. Anti-CCHFV antibodies were found in 1,026 of 5,291 wild boar (19.4 %; 95 % confidence interval: 18.3-20.5 %), with highest exposure rates in southwestern Iberia. The most relevant predictors of virus exposure risk were wild boar abundance, local rainfall regime, shrub cover, winter air temperature and soil temperature variation. The spatial projection of the best-fit model identified high-risk foci as occurring in most of western and southwestern Iberia and identified recently confirmed risk foci in eastern Spain. The results of the study demonstrate that serological surveys of CCHFV vector hosts are a powerful, robust and highly informative tool for public health authorities to take action to prevent human cases of CCHF in enzootic and emergency settings.

Antibiotic treatment of post-appendectomy abscesses in children, regardless of size: a twelve years' experience.

Intra-abdominal abscesses are a common issue after appendectomy. Antibiotics have shown efficacy in treating smaller abscesses, while larger ones have traditionally been treated with drainage. This study assesses the efficacy of antibiotics for post-appendectomy intra-abdominal abscess (PAA) in children regardless of size. Case-control study of children with PAA admitted at our hospital from 2010 to 2022. The efficacy of antibiotics was compared between abscesses less and more than 6 cm in diameter. The Institutional Review Board has approved this study. A total of 1766 appendectomies were performed from 2010 to 2022 with an incidence of PAA of 5% (n = 89): age 9.3 IQR 5.8, 63% male (n = 56). Sixty-seven patients presented with a ≤ 6 cm abscess (controls) and 22 children had a > 6 cm PAA (cases). Length of intravenous antibiotics were higher in cases (15 IQR 7 days) than controls (12 IQR 4 days), p = 0.003. The efficacy of antibiotics in controls was 97% whereas 86.4% in cases (p = 0.094), reoperation was needed in 2/67 controls and 3/22 cases, with no differences in complications or readmission. The length of stay was longer in cases (15 IQR 6 days) than controls (13 IQR 5 days), p = 0.042. Antibiotics seem a safe treatment for PAA in children regardless of the size. However, this approach is associated with a longer period of intravenous antibiotics and hospital stay, although not with a higher rate of therapeutic failure, complications or reoperations.

Measures of spatial heterogeneity in the liver tissue micro-environment as predictive factors for fibrosis score.

The organization and interaction between hepatocytes and other hepatic non-parenchymal cells plays a pivotal role in maintaining normal liver function and structure. Although spatial heterogeneity within the tumor micro-environment has been proven to be a fundamental feature in cancer progression, the role of liver tissue topology and micro-environmental factors in the context of liver damage in chronic infection has not been widely studied yet. We obtained images from 110 core needle biopsies from a cohort of chronic hepatitis B patients with different fibrosis stages according to METAVIR score. The tissue sections were immunofluorescently stained and imaged to determine the locations of CD45 positive immune cells and HBsAg-negative and HBsAg-positive hepatocytes within the tissue. We applied several descriptive techniques adopted from ecology, including Getis-Ord, the Shannon Index and the Morisita-Horn Index, to quantify the extent to which immune cells and different types of liver cells co-localize in the tissue biopsies. Additionally, we modeled the spatial distribution of the different cell types using a joint log-Gaussian Cox process and proposed several features to quantify spatial heterogeneity. We then related these measures to the patient fibrosis stage by using a linear discriminant analysis approach. Our analysis revealed that the co-localization of HBsAg-negative hepatocytes with immune cells and the co-localization of HBsAg-positive hepatocytes with immune cells are equally important factors for explaining the METAVIR score in chronic hepatitis B patients. Moreover, we found that if we allow for an error of 1 on the METAVIR score, we are able to reach an accuracy of around 80%. With this study we demonstrate how methods adopted from ecology and applied to the liver tissue micro-environment can be used to quantify heterogeneity and how these approaches can be valuable in biomarker analyses for liver topology.