Demographic and clinical characterization of pediatric group patients with inborn errors of the immune system in a Colombian tertiary hospital

Introduction: In recent decades, there has been a growing increase in the diagnosis of patients with inborn errors of the immune system, formerly known as primary immunodeficiency dis-orders (PIDs). Timely diagnosis remains a challenge due to low clinical suspicion and poor edu-cation on the subject. It is estimated that between 70% and 90% of these pathologies remain underdiagnosed in our environment.Objective: The objective of this study is to characterize the demographic and clinical presen-tation of pediatric group patients with inborn errors of the immune system in a Colombian tertiary hospital.Methods: Retrospective descriptive study of 306 patients with a diagnosis of innate errors of the immune system who consulted the PID clinic between 2011 and 2018 in a high-complexity institution in Cali, Colombia.Results: Three-hundred and six patients were included. The median age was 4 years (IQR 2.3–7.7 years), and 59.5% of the patients were male. According to the International Union of Immunological Societies Expert Committee for Primary Immunodeficiency classification for inborn errors of the immune system, the most common group was antibody deficiency in 74.8% (n=229), especially in the age group between 1 and 5 years. The least frequent in our pop-ulation was complement deficiency. Of the warning signs stipulated for these pathologies, the most frequent were the (1) need for intravenous antibiotics (32%), (2) difficulty growing (15.7%), (3) four or more episodes of ear infection (10.8%), and (4) abscesses in organs or cuta-neous abscesses (12.7%). No patient reported two or more episodes of pneumonia or sinusitis, and only 5.8% of the patients received a bone marrow transplant (AU)

La variante missense rs2908004 de WNT16 actúa como eQTL de FAM3C en osteoblastos primarios humanos / WNT16 rs2908004 missense variant acts as eQTL of FAM3C in human primary osteoblasts

Introducción: WNT16 es un gen importante en la homeostasis ósea, que se encuentra en un locus muy complejo que también incluye los genes vecinos: ING3. FAM3C y CPED1. Además del claro papel de WNT16 sobre la determinación de la densidad mineral ósea (DMO), también se han encontrado pruebas sobre la importancia de estos tres genes vecinos en el metabolismo óseo. Queda por tanto esclarecer si las variantes en WNT16 asociadas a la DMO realizan su efecto propiamente sobre WNT16 o si lo hacen modificando la expresión de estos genes vecinos. Material y métodos: Hemos determinado los niveles de expresión de CPED1 y FAM3C en osteoblastos primarios y hemos comprobado si variantes de WNT16 se comportan como loci de rasgos cuantitativos de expresión (expresion quantitative trait loci; eQTL) de estos genes. Resultados: La variante de cambio de aminoácido rs2908004 en WNT16 actúa como eQTL de FAM3C en osteoblastos primarios bajo la hipótesis de modelo dominante. Discusión: Es posible que el efecto de esta variante sobre la DMO sea debido a la modificación de los niveles de expresión de FAM3C además o en vez de un efecto directo de la proteína WNT16 mutante resultante del cambio de aminoácido. (AU)

Introduction: WNT16 is an important gene in bone homeostasis, found in a very complex locus that also includes neighboring genes: ING3, FAM3C, and CPED1. In addition to the clear role of WNT16 in determining bone mineral density (BMD), evidence has also been found for the importance of these three neighboring genes in bone metabolism. Therefore, it remains to be clarified whether the variants in WNT16 associated with BMD carry out their effect on WNT16 or if they do so by modifying the expression of these neighboring genes. Material and methods: We have determined the expression levels of CPED1 and FAM3C in primary osteoblasts and we have verified whether WNT16 variants behave as loci of quantitative expression traits (expression quantitative trait loci; eQTL) of these genes. Results: The amino acid change variant rs2908004 in WNT16 acts as the eQTL of FAM3C in primary osteoblasts under the dominant model hypothesis. Discussion: It is possible that the effect of this variant on BMD is due to the modification of the expression levels of FAM3C in addition to or instead of a direct effect of the mutant WNT16 protein resulting from the amino acid change. (AU)

Atypical Charles Bonnet syndrome secondary to frontal meningioma: a case report.

BACKGROUND: Charles Bonnet Syndrome (CBS) is a rare clinical entity that is classically composed of visual hallucinations in the context of an altered optic pathway with preservation of reality judgment. This case aims to present the association of visual hallucinations with complex alterations of the nervous structures adjacent to the visual pathway and an atypical clinical presentation, thus explaining the possible mechanisms involved in the generation of these symptoms. CASE PRESENTATION: A 43-year-old man presents seeking care due to visual hallucinations with partial preservation of reality judgment and symptoms compatible with a major depressive disorder, including irritability and diminished hygiene habits. He has a history of complete gradual loss of vision and hyposmia. Due to poor treatment response during hospitalization, an MRI was obtained, which showed a frontal tumor lesion with meningioma characteristics adjacent to the olfactory groove and compression of the optic chiasm. He underwent surgical resection of the lesion, which remitted the psychotic symptoms, but preserving the visual limitation and depressive symptoms. CONCLUSIONS: The presence of visual hallucinations, without other psychotic features as delusions, is a focus of attention for basic structural pathologies in the central nervous system. Affection at any level of the visual pathway can cause CBS. When finding atypical symptoms, a more in-depth evaluation should be made to allow optimization of the diagnosis and treatment.

Bevacizumab in recurrent ovarian cancer: could it be particularly effective in patients with clear cell carcinoma?

Purpose Treatment of recurrent ovarian carcinoma is a challenge, particularly for the clear cell (CCC) subtype. However, there is a preclinical rationale that these patients could achieve a benefit from antiangiogenic therapy. To assess this hypothesis, we used the growth modulation index (GMI), which represents an intrapatient comparison of two successive progression-free survival (PFS). Methods We conducted a retrospective real-world study performed on 34 patients with recurrent ovarian cancer, treated with bevacizumab-containing regimens from January 2009 to December 2017. The primary endpoint was GMI. An established cut-off > 1.33 was defined as a sign of drug activity. Results 73.5% of patients had high-grade serous ovarian carcinoma (HGSOC), and 17.7% had CCC; 70.6% of patients received carboplatin/gemcitabine/bevacizumab, and 29.4% received weekly paclitaxel/bevacizumab. According to histological subtype, the overall response rate and median PFS were 52% and 14 months for HGSOC and 83.3% and 20 months for CCC, respectively. The overall population median GMI was 0.99; it was 0.95 and 2.36 for HGSOC and CCC, respectively. CCC subtype was significantly correlated with GMI > 1.33 (odds ratio 41.67; 95% confidence interval 3.6–486.94; p = .03). Conclusion Adding bevacizumab to chemotherapy in recurrent CCC is associated with a remarkable benefit in this cohort. The efficacy of antiangiogenic drugs in CCC warrants further prospective evaluation (AU)

On the structural and thermo-magnetic study of the magnetocaloric Heusler alloy Ni2Mn1-xCuxGa0.8Al0.2.

Full Heusler alloys present martensitic transition and shape memory effect related phenomena and several technological applications can be envisaged. One promising area is the magnetocaloric effect (MCE) as the magnetic and structural transitions combine to produce a large isothermal entropy and adiabatic temperature change useful for heating and cooling applications. In this work, we study a Ni-(Mn, Cu)-(Ga, Al) Heusler alloy family which has a giant MCE when the chemical composition is fine-tuned to bring the temperature of the second-order magnetic transition close the first-order structural one. Our results show that, for a certain range of copper concentration, the samples show interesting physical properties captured by calorimetric, microscopy imaging, and magnetization measurements, leading to a high MCE with minimized hysteresis.

Paratricipital approach for distal humerus fractures.

OBJECTIVE: To report functional outcomes in a case series of distal shaft and distal humeral fractures (AO type 12 and 13) managed with open reduction and internal fixation using paratricipital approach. METHODS: Patients who were intervened between May 2006 and December 2015 were included in the analysis. The Mayo Elbow Performance Score (MEPS), the Disabilities of the Arm, Shoulder and Hand (DASH) score and the visual analogue scale (VAS) were used for functional assessment. RESULTS: Twelve patients were included in this case series, eight (67%) of them were women. The average age was 46 (SD 22). Regarding the type of fracture, three (25%) were classified as 12A1, two (17%) as 12B1, two (17%) as 12B2, three (25%) as 13C1 and two (17%) as 13C2. At most recent average follow-up of 3, 4 years (DS 1,62), the results were: elbow range of flexion-extension 138,3º (SD 15,18), MEPS reached 85,8 (DS 11,7), DASH of 11,8 (SD 10,6) and the mean VAS 1,3 (SD 1,1). At the final evaluation, all fractures had healed. One case presented radial nerve neuropraxia, three cases paresthesias at the ulnar nerve territory, and all of these evolved positively and spontaneously. CONCLUSIONS: In our experience, posterior paratricipital approach is useful and safe for managing the open reduction and internal fixation. It may provide preservation of the triceps and promote an earlier rehabilitation. Functional outcomes were satisfactory in this case series.

Bevacizumab in recurrent ovarian cancer: could it be particularly effective in patients with clear cell carcinoma?

PURPOSE: Treatment of recurrent ovarian carcinoma is a challenge, particularly for the clear cell (CCC) subtype. However, there is a preclinical rationale that these patients could achieve a benefit from antiangiogenic therapy. To assess this hypothesis, we used the growth modulation index (GMI), which represents an intrapatient comparison of two successive progression-free survival (PFS). METHODS: We conducted a retrospective real-world study performed on 34 patients with recurrent ovarian cancer, treated with bevacizumab-containing regimens from January 2009 to December 2017. The primary endpoint was GMI. An established cut-off > 1.33 was defined as a sign of drug activity. RESULTS: 73.5% of patients had high-grade serous ovarian carcinoma (HGSOC), and 17.7% had CCC; 70.6% of patients received carboplatin/gemcitabine/bevacizumab, and 29.4% received weekly paclitaxel/bevacizumab. According to histological subtype, the overall response rate and median PFS were 52% and 14 months for HGSOC and 83.3% and 20 months for CCC, respectively. The overall population median GMI was 0.99; it was 0.95 and 2.36 for HGSOC and CCC, respectively. CCC subtype was significantly correlated with GMI > 1.33 (odds ratio 41.67; 95% confidence interval 3.6-486.94; p = .03). CONCLUSION: Adding bevacizumab to chemotherapy in recurrent CCC is associated with a remarkable benefit in this cohort. The efficacy of antiangiogenic drugs in CCC warrants further prospective evaluation.

Características clínicas y sociosanitarias en mayores de 65 años asistidos en atención primaria. Estudio PYCAF / Clinical and socio-sanitary characteristics in adults older than 65 years attended in the Primary Care setting. The PYCAF study

OBJETIVO: Describir las características clínicas y sociosanitarias de los pacientes mayores de 65 años atendidos en consultas de atención primaria. MATERIAL Y MÉTODOS: El estudio PYCAF (Prevalencia Y Características del Anciano Frágil) es un estudio descriptivo, transversal y multicéntrico. Se incluyeron de manera consecutiva sujetos mayores de 65 años, atendidos en las consultas de atención primaria de toda España en condiciones de práctica clínica habitual. RESULTADOS: Se analizaron un total de 2.461 pacientes (edad media de 76,0+/-6,9 años; 57,9% mujeres). La coexistencia de factores de riesgo cardiovascular y comorbilidades fue frecuente, siendo las más prevalentes: hipertensión arterial (73,7%), dislipidemia (58,3%), artrosis (56,4%), obesidad (34,0%) y diabetes (28,9%). El 13,4% de los pacientes tenían algún grado de deterioro cognitivo. Las mujeres mostraron un mayor grado de fragilidad (61,0% vs.51,8%; p < 0,001). El 47,4% de los pacientes tomaban más de 6 fármacos, siendo mayor el consumo en las mujeres (44,2% vs.49,8%; p = 0,047). El 49,5% de los pacientes realizaron más de 10 visitas a atención primaria, el 25,9% 4 o más visitas a atención especializada y un 22,3% estuvieron ingresados en el último año. CONCLUSIONES: El estudio PYCAF nos muestra que los pacientes ancianos tienen mayor prevalencia de enfermedades crónicas cardiovasculares y no cardiovasculares, lo que conduce a una elevada polimedicación. Esta última tiene consecuencias tanto en la seguridad del paciente como en los costes directos e indirectos sobre el Sistema Nacional de Salud que emanan de la asistencia al paciente mayor de 65 años. La prevalencia de fragilidad alcanza a la mitad de la muestra

OBJECTIVE: To describe the clinical and socio-sanitary characteristics of adults older than 65 years attended in a Primary Care setting. MATERIAL AND METHODS: The PYCAF study (Prevalence and Characteristics of the Fragile Elderly) is a descriptive, cross-sectional and multicentre study, in which patients older than 65 years attended in clinical practice in Primary Care in Spain were consecutively included. RESULTS: A total of 2,461 patients (mean age 76.0+/-6.9 years, 57.9% women) were included in the study. The coexistence of cardiovascular risk factors and comorbidities was frequent, with arterial hypertension (73.7%) being the most prevalent, followed by dyslipidaemia (58.3%), arthrosis (56.4%), obesity (34.0%), and diabetes (28.9%). Some degree of cognitive impairment was observed in 13.4% of patients. Women had higher rates of frailty (61.0% vs.51.8%; P<.001). Just under half (47.4%) of subjects were taking more than 6 drugs, with the prescription being higher in women (44.2% vs.49.8%; P=.047). Just under half (49.5%) of patients made more than 10 visits to Primary Care, 25.9% of patients 4 or more visits to the specialist, and 22.3% of patients were admitted to hospital in the last year. CONCLUSIONS: The PYCAF study shows that elderly patients have a higher prevalence of chronic cardiovascular and non-cardiovascular diseases, which leads to high polypharmacy. The latter has consequences both on patient safety and on the direct and indirect costs of the National Health System that emanate from the care of patients over 65 years of age. Half the sample has fragility

Do mosses really exhibit so large distribution ranges? Insights from the integrative taxonomic study of the Lewinskya affinis complex (Orthotrichaceae, Bryopsida).

The strikingly lower number of bryophyte species, and in particular of endemic species, and their larger distribution ranges in comparison with angiosperms, have traditionally been interpreted in terms of their low diversification rates associated with a high long-distance dispersal capacity. This hypothesis is tested here with Lewinskya affinis (≡ Orthotrichum affine), a moss species widely spread across Europe, North and East Africa, southwestern Asia, and western North America. We tested competing taxonomic hypotheses derived from separate and combined analyses of multilocus sequence data, morphological characters, and geographical distributions. The best hypothesis, selected by a Bayes factor molecular delimitation analysis, established that L. affinis is a complex of no less than seven distinct species, including L. affinis s.str., L. fastigiata and L. leptocarpa, which were previously reduced into synonymy with L. affinis, and four new species. Discriminant analyses indicated that each of the seven species within L. affinis s.l. can be morphologically identified with a minimal error rate. None of these species exhibit a trans-oceanic range, suggesting that the broad distributions typically exhibited by moss species largely result from a taxonomic artefact. The presence of three sibling western North American species on the one hand, and four Old World sibling species on the other, suggests that there is a tendency for within-continent diversification rather than recurrent dispersal following speciation. The faster rate of diversification as compared to intercontinental migration reported here is in sharp contrast with earlier views of bryophyte species with wide ranges and low speciation rates.

No borders during the post-glacial assembly of European bryophytes.

Climatic fluctuations during the Last Glacial Maximum (LGM) exerted a profound influence on biodiversity patterns, but their impact on bryophytes, the second most diverse group of land plants, has been poorly documented. Approximate Bayesian computations based on coalescent simulations showed that the post-glacial assembly of European bryophytes involves a complex history from multiple sources. The contribution of allochthonous migrants was 95-100% of expanding populations in about half of the 15 investigated species, which is consistent with the globally balanced genetic diversities and extremely low divergence observed among biogeographical regions. Such a substantial contribution of allochthonous migrants in the post-glacial assembly of Europe is unparalleled in other plants and animals. The limited role of northern micro-refugia, which was unexpected based on bryophyte life-history traits, and of southern refugia, is consistent with recent palaeontological evidence that LGM climates in Eurasia were much colder and drier than what palaeoclimatic models predict.

Factors associated with delirium in critical patients in a health institution in Bucaramanga, Colombia. / Factores asociados con el delírium en pacientes críticos de una institución de salud de Bucaramanga, Colombia.

OBJECTIVE: To determine the incidence and the factors associated with delirium in intensive care unit patients. METHODS: A cohort study conducted on 134 patients in the intensive care unit at a clinic in Bucaramanga, Colombia., who were recruited in the first 24hours following admission and on whom the Richmond Agitation-Sedation Scale (RASS), PRE-DELIRIC version in Spanish, and Confusion Assessment method for Intensive Care Unit (CAM-ICU) were applied; the outcome was evaluated through daily monitoring with CAM-ICU. RESULTS: The incidence of delirium was 20.2%, the predominating type was hypoactive at 66.7%, followed by the hyperactive type at 7.4% and mixed at 25.9%. Fifty-two percent of the patients with delirium died. In the bivariate analysis, the use of sedatives (Relative Risk(RR) 2.4, 95% confidence interval (95% CI) = 1.2-4.5), infection (RR = 2. 8, 95% CI=1.3-5.9), metabolic acidosis (RR = 4 3, 95% CI=2.3-8.0), mechanical ventilation (RR = 4 6, 95% CI=2.0-10.6), aged over 60 years (RR = 2 3, 95% CI=1.09-5.3) and APACHE score greater than 14 (RR = 3. 0) (95% CI=1.1-8.2) were identified as risk factors for delirium. The multivariate analysis only found a relationship with infection (RR = 3 8, 95% CI=1.6-9.1) and being aged over 60 years (RR = 3 2, 95% CI 1.2-8.3). CONCLUSIONS: delirium is frequent in patients in the intensive care unit, especially the hypoactive type. Half of the patients with delirium died. The main risk factors for delirium are infection and being over 60 years age, therefore, delirium prevention activities should focus on these critical patients.

[Clinical and socio-sanitary characteristics in adults older than 65 years attended in the Primary Care setting. The PYCAF study]. / Características clínicas y sociosanitarias en mayores de 65 años asistidos en atención primaria. Estudio PYCAF.

OBJECTIVE: To describe the clinical and socio-sanitary characteristics of adults older than 65 years attended in a Primary Care setting. MATERIAL AND METHODS: The PYCAF study (Prevalence and Characteristics of the Fragile Elderly) is a descriptive, cross-sectional and multicentre study, in which patients older than 65 years attended in clinical practice in Primary Care in Spain were consecutively included. RESULTS: A total of 2,461 patients (mean age 76.0±6.9 years, 57.9% women) were included in the study. The coexistence of cardiovascular risk factors and comorbidities was frequent, with arterial hypertension (73.7%) being the most prevalent, followed by dyslipidaemia (58.3%), arthrosis (56.4%), obesity (34.0%), and diabetes (28.9%). Some degree of cognitive impairment was observed in 13.4% of patients. Women had higher rates of frailty (61.0% vs. 51.8%; P<.001). Just under half (47.4%) of subjects were taking more than 6 drugs, with the prescription being higher in women (44.2% vs. 49.8%; P=.047). Just under half (49.5%) of patients made more than 10 visits to Primary Care, 25.9% of patients 4 or more visits to the specialist, and 22.3% of patients were admitted to hospital in the last year. CONCLUSIONS: The PYCAF study shows that elderly patients have a higher prevalence of chronic cardiovascular and non-cardiovascular diseases, which leads to high polypharmacy. The latter has consequences both on patient safety and on the direct and indirect costs of the National Health System that emanate from the care of patients over 65 years of age. Half the sample has fragility.

Effect of chlorhexidine baths on central-line-associated bloodstream infections in a neonatal intensive care unit in a developing country.

Healthcare-associated infections, particularly central-line-associated bloodstream infections (CLABSIs), are worrisome in neonates. This study describes the impact of chlorhexidine baths on CLABSI rates in a neonatal intensive care unit in a developing country, through a quasi-experimental study undertaken over 62 months (January 2012 to February 2017) divided into two periods: before and after the implementation of a protocol for chlorhexidine baths in July 2014. The rate of CLABSIs per 1000 central-line-days decreased from 8.64 to 4.28 after implementation of the protocol. The use of chlorhexidine baths appears to reduce the number of CLABSIs in neonates.

In vitro anti-Acanthamoeba synergistic effect of chlorhexidine and cationic carbosilane dendrimers against both trophozoite and cyst forms.

Acanthamoeba sp. are the causative agents of severe illnesses in humans such as Acanthamoeba keratitis (AK) and granulomatous amoebic encephalitis (GAE). Medical therapy is not yet well established. Treatments of AK last for several months and generate toxicity, resistances appear due to the cysts stage and recurrences can occur. In this study has been demonstrated that the combination of chlorhexidine digluconate (CLX) and carbosilane dendrimers containing ammonium or guanidine moieties has in vitro synergistic effect against Acanthamoeba polyphaga. This synergy provokes an important reduction in the minimal trophozoite amoebicidal concentration (MTAC) of CLX, which means a reduction of their toxic effects on human cells. Moreover, some CLX/dendrimer combinations show important activity against the cyst resistance stage.

Participación en un programa de acondicionamiento físico y capacidad funcional en sujetos sometidos a angioplastia por síndrome coronario agudo / Participation in a fitness program and functional capacity in patients undergoing angioplasty for acute coronary syndrome

Objetivo: Describir la capacidad funcional de sujetos que participaron o no de un programa de acondicionamiento físico después de ser sometidos a angioplastia coronaria. Metodología: Estudio de corte transversal realizado en 19 sujetos (68,4% hombres) con síndrome coronario agudo sometidos a angioplastia coronaria entre junio y agosto del 2010, aptos para la realización de una prueba de esfuerzo. La variable dependiente fue la capacidad funcional evaluada por medio de protocolos de Bruce y Bruce modificado; la variable independiente principal fue la participación en el programa de acondicionamiento físico. Se realizaron análisis de regresión lineal simple y múltiple para establecer las variables asociadas a capacidad funcional. Resultados: Se encontró que las personas que asisten al programa alcanzan 2,57 MET por encima de las personas que no asisten (p = 0,003), ajustado por antecedentes de hipertensión arterial y obesidad. Por el contrario, las personas obesas alcanzan 3,04 MET menos comparadas con las personas no obesas, ajustado por asistencia al programa e hipertensión arterial (p = 0,003). Conclusiones: En el análisis ajustado, se encontró asociación entre la participación en un programa de acondicionamiento físico y la capacidad funcional, por lo que se recomienda la inclusión y la participación de los sujetos que han recibido revascularización percutánea, en un programa de acondicionamiento físico dentro de su proceso de rehabilitación

Objective: To describe the functional capacity of subjects who participated compared to those who did not participate in a Fitness program after undergoing coronary angioplasty. Methodology: A cross-sectional study was conducted in 19 subjects (68.4% men) with acute coronary syndrome undergoing coronary angioplasty between June and August 2010, who were appropriate for conducting a stress test. The dependent variable was functional capacity assessed by the modified Bruce and Bruce protocols. The main independent variable was participation in the fitness program. Simple and multiple linear regression analyses were performed to establish the variables associated with functional capacity. Results: We found that the subjects who attended the program achieved 2.57 MET above those who did not attend the program (P=.003), adjusted for history of hypertension and obesity. Conversely, obese people reached 3.04 MET less when compared with non-obese individuals, adjusted for program assistance and hypertension (P=.003). Conclusions: In the adjusted analysis, an association was found between participation in a fitness program and functional capacity. Thus, inclusion and participation of subjects who have received percutaneous revascularization in a fitness program within their rehabilitation process is recommended

How to define nativeness in vagile organisms: lessons from the cosmopolitan moss Bryum argenteum on the island of Tenerife (Canary Islands).

The distinction between native and introduced biotas presents unique challenges that culminate in organisms with high long-distance dispersal capacities in a rapidly changing world. Bryophytes, in particular, exhibit large distribution ranges, and some species can truly be qualified as cosmopolitan. Cosmopolitan species, however, typically occur in disturbed environments, raising the question of their nativeness throughout their range. Here, we employ genetic data to address the question of the origin of the cosmopolitan, weedy moss Bryum argenteum on the island of Tenerife. The genetic diversity of B. argenteum on Tenerife was comparable to that found in continental areas due to recurrent colonisation events, erasing any signature of a bottleneck that would be expected in the case of a recent colonisation event. The molecular dating analyses indicated that the first colonisation of the island took place more than 100,000 years ago, i.e. well before the first human settlements. Furthermore, the significant signal for isolation-by-distance found in B. argenteum within Tenerife points to the substantial role of genetic drift in establishing the observed patterns of genetic variation. Together, the results support the hypothesis that B. argenteum is native on Tenerife; although the existence of haplotypes shared between Tenerife and continental areas suggests that more recent, potentially man-mediated introduction also took place. While defining nativeness in organisms that are not deliberately introduced, and wherein the fossil record is extremely scarce, is an exceedingly challenging task, our results suggest that population genetic analyses can represent a useful tool to help distinguish native from alien populations.

Development of a new oxygen consumption rate assay in cultures of Acanthamoeba (Protozoa: Lobosea) and its application to evaluate viability and amoebicidal activity in vitro.

A new fluorometric method has been developed for measuring the oxygen consumption rate (OCR) of Acanthamoeba cultures in microplates and for screening molecules with amoebicidal activity against this microorganism. The use of a biofunctional matrix (containing an oxygen-sensitive fluorogenic probe) attached to the microplate wells allowed continuous measurement of OCR in the medium, hence assessment of amoebic growth. The new OCR method applied to cell viability yielded a linear relationship and monitoring was much quicker than with indirect viability assays previously used. In addition, two drugs were tested in a cytotoxicity assay monitored by the new OCR viability test. With this procedure, the standard amoebicidal drug chlorhexidine digluconate showed an IC50 of 3.53 + 1.3 mg/l against Acanthamoeba polyphaga and 3.19 + 1.2 mg/l against Acanthamoeba castellanii, whereas a cationic dendrimer [G1Si(NMe3+)4] showed an IC50 of 6.42 + 1.3 mg/l against A. polyphaga. These data agree with previous studies conducted in our laboratory. Therefore, the new OCR method has proven powerful and quick for amoebicidal drug screening and is likely to be applied in biochemical studies concerning protozoa respiration and metabolism.

Characterization of a human-pathogenic Acanthamoeba griffini isolated from a contact lens-wearing keratitis patient in Spain.

Amoebae were isolated from contact lenses of a symptomatic lens wearer in Spain. Protozoa were characterized by studying their morphology, biology, protease activity and the 18S rRNA gene sequence. Morphology of the organism was observed by light microscopy, scanning electron microscopy and transmission electron microscopy. Its structure corresponded to an amphizoic amoeba. The protozoa grew well at 37 °C and poorly at lower temperatures. In addition, it was capable of lysing mammalian cells in vitro. A major 56 kDa proteolytic enzyme was observed in amoeba crude extracts by gelatin-sodium dodecyl sulphate-polyacrylamide gel electrophoresis. Most proteolytic enzymes in protozoa extracts showed significant activity over a wide range of pH (3-9) and temperature (8-45 °C) values. The assays on inhibition of protease activity indicated strongly that enzymes detected in amoeba extracts corresponded to serine proteases and, to a lesser extent, cysteine proteases. The use of proteinase inhibitors on a tissue culture model proved that the proteinase activity is critical for developing focal lesions in HeLa cell monolayers. Finally, partial sequencing of the 18S ribosomal RNA gene and phylogenetic analyses indicated that the isolate is closely related to Acanthamoeba griffini H37 from the UK (T3 genotype).

Extant diversity of bryophytes emerged from successive post-Mesozoic diversification bursts.

Unraveling the macroevolutionary history of bryophytes, which arose soon after the origin of land plants but exhibit substantially lower species richness than the more recently derived angiosperms, has been challenged by the scarce fossil record. Here we demonstrate that overall estimates of net species diversification are approximately half those reported in ferns and ∼30% those described for angiosperms. Nevertheless, statistical rate analyses on time-calibrated large-scale phylogenies reveal that mosses and liverworts underwent bursts of diversification since the mid-Mesozoic. The diversification rates further increase in specific lineages towards the Cenozoic to reach, in the most recently derived lineages, values that are comparable to those reported in angiosperms. This suggests that low diversification rates do not fully account for current patterns of bryophyte species richness, and we hypothesize that, as in gymnosperms, the low extant bryophyte species richness also results from massive extinctions.

3D free-standing porous scaffolds made of graphene oxide as substrates for neural cell growth.

The absence of efficient therapies for the treatment of lesions affecting the central nervous system encourages scientists to explore new materials in an attempt to enhance neural tissue regeneration while preventing inhibitory fibroglial scars. In recent years, the superlative properties of graphene-based materials have provided a strong incentive for their application in biomedicine. Nonetheless, a few attempts to date have envisioned the use of graphene for the fabrication of three-dimensional (3D) substrates for neural repair, but none of these involve graphene oxide (GOx) despite some attractive features such as higher hydrophilicity and versatility of functionalization. In this paper, we report novel, free-standing, porous and flexible 3D GOx-based scaffolds, produced by the biocompatible freeze-casting procedure named ISISA, with potential utility in neural tissue regeneration. The resulting materials were thoroughly characterized by Fourier-transform infrared, Raman, and X-ray photoelectron spectroscopies and scanning electron microscopy, as well as flexibility testing. Embryonic neural progenitor cells were then used to investigate adhesion, morphology, viability, and neuronal/glial differentiation. Highly viable and interconnected neural networks were formed on these 3D scaffolds, containing both neurons and glial cells and rich in dendrites, axons and synaptic connections, and the results are in agreement with those obtained in initial studies performed with two-dimensional GOx films. These results encourage further investigation in vivo on the use of these scaffolds as guide substrates to promote the repair of neural injuries.