[Incidence, circumstances and consequences of falls in subjects with stroke: One year of follow-up]. / Incidencia, circunstancias y consecuencias de caídas en sujetos con accidente cerebrovascular: un año de seguimiento.

INTRODUCTION: Falls are among the most frequent complications following stroke (CVA), and have a negative impact on rehabilitation. OBJECTIVES: To study the incidence, circumstances, and consequences of falls in stroke patients up to 12months after starting outpatient kinetic treatment. MATERIALS AND METHODS: Prospective design, case series. Consecutive sampling. Patients admitted to the day hospital between June 2019 and May 2020. Included: adults with a diagnosis of first supratentorial stroke and functional ambulatory category score ≥3. EXCLUSION CRITERIA: other condition affecting locomotion. MAIN VARIABLES: number of falls, circumstances, and consequences. Clinical, demographic, and functional characteristics were measured. RESULTS: Twenty-one subjects were included, 13 suffered at least one fall. The subjects reported 41 falls: 15 were to the most affected side, 35 inside the home, 28 without the indicated equipment, they were alone when the event occurred on 29 occasions, and in two situations medical assistance was required. There were statistically significant differences (P<.05) in functional performance (balance, gait velocity) between those who fell and those who did not. No significant differences were found between gait endurance and falls. CONCLUSION: More than half suffered a fall, alone, to the weaker side, and without the appropriate equipment. With this information the incidence could be reduced by preventive measures.

Mutation and SARS-CoV-2 strain competition under vaccination in a modified SIR model.

The crisis caused by the COVID-19 outbreak around the globe raised an increasing concern about the ongoing emergence of variants of the virus that may evade the immune response provided by vaccines. New variants appear due to mutation, and as the cases accumulate, the probability of the emergence of a variant of concern increases. In this article, we propose a modified susceptible, infected, and recovered (SIR) model with waning immunity that captures the competition of two strain classes of an infectious disease under the effect of vaccination with a highly contagious and deadlier strain class emerging from a prior strain due to mutation. When these strains compete for a limited supply of susceptible individuals, changes in the efficiency of vaccines may affect the behaviour of the disease in a non-trivial way, resulting in complex outcomes. We characterise the parameter space including intrinsic parameters of the disease, and using the vaccine efficiencies as control variables. We find different types of transcritical bifurcations between endemic fixed points and a disease-free equilibrium and identify a region of strain competition where the two strain classes coexist during a transient period. We show that a strain can be extinguished either due to strain competition or vaccination, and we obtain the critical values of the efficiency of vaccines to eradicate the disease. Numerical studies using parameters estimated from publicly reported data agree with our theoretical results. Our mathematical model could be a tool to assess quantitatively the vaccination policies of competing and emerging strains using the dynamics in epidemics of infectious diseases.

A mild case of hemolytic disease of the fetus and newborn due to anti-Sc2.

We report the case of a newborn girl with jaundice due to increased indirect bilirubin with a positive direct antiglobulin test (DAT) and compensated hemolysis. The result of the newborn's DAT was discrepant with the negative result of the mother's indirect antiglobulin test. The multiparous mother had a previous history of fetal hydrops miscarriage, with no known cause, and no record of the cause was found at the hospital where she was treated. After referring samples from the mother and newborn to a reference laboratory, the rare alloanti-Sc2 was identified in the mother's plasma and in the newborn's eluate. HEA BeadChip genotyping of the newborn's DNA sample predicted the SC:1,2 phenotype.We report the case of a newborn girl with jaundice due to increased indirect bilirubin with a positive direct antiglobulin test (DAT) and compensated hemolysis. The result of the newborn's DAT was discrepant with the negative result of the mother's indirect antiglobulin test. The multiparous mother had a previous history of fetal hydrops miscarriage, with no known cause, and no record of the cause was found at the hospital where she was treated. After referring samples from the mother and newborn to a reference laboratory, the rare alloanti-Sc2 was identified in the mother's plasma and in the newborn's eluate. HEA BeadChip genotyping of the newborn's DNA sample predicted the SC:1,2 phenotype.

The pore forming capacity of Sticholysin I in dipalmitoyl phosphatidyl vesicles is tuned by osmotic stress.

The osmotic condition modulates the properties of liposomes, particularly those related to their stability and response to external agents such as membrane-active proteins or peptides. In a previous work, we have demonstrated that an osmotic shock can increase, per se, water influx/efflux and the exit of the fluorophore calcein entrapped in the aqueous pool of dipalmitoylphosphatidylcholine (DPPC) and DPPC:sphingomyelin (SM) large unilamellar vesicles (LUVs), suggesting a loss of integrity of the liposome bilayer. In the present work, we have extended our study in order to assess how an osmotic imbalance prior to or synchronous with the addition of a recombinant variant of the pore-forming toxin sticholysin I (rSt I) modifies its pore forming capacity in DPPC and DPPC:SM (1:1) LUVs. Our results conclusively show the capacity of hypotonic gradients to improve the pore forming capacity of rSt I molecules, even in pure DPPC liposomes, rendering pore-formation less dependent on the presence of sphyngomyelin. In fact, non-active toxins in DPPC liposomes become active by a hypotonic imbalance in a similar way to those containing SM as a second component.

Novel specific peptides as superior surface stabilizers for silver nano structures: role of peptide chain length.

Three new collagen mimetic peptides containing the CLK motif as anchoring arms were tested for silver nanoparticle surface stabilization. Our experimental and molecular dynamics data indicate that peptide length has an important effect not only in the resulting nanosilver's colloidal stability, but also in the biological performance of the composite.

Response of unilamellar DPPC and DPPC:SM vesicles to hypo and hyper osmotic shocks: A comparison.

DPPC and DPPC:SM large unilamellar vesicles (LUVs), prepared by extrusion, readily respond to osmotic shocks (hypo- and hyper-osmotic) by water influx/efflux (evaluated by changes in turbidity) and by entrapped calcein liberation (measured by an increase in dye fluorescence intensity). On the other hand, small unilamellar vesicles (SUVs) prepared by sonication are almost osmotically insensitive. LUVs water transport, both in hypo- and hyper-osmotic conditions, takes place faster than calcein ejection towards the external solvent. Similarly, response to a hypotonic imbalance is faster than that associated to a hypertonic stress. This difference is particularly noticeable for the increase in calcein fluorescence intensity and can be related to the large reorganization of the bilayer needed to form pores and/or to adsorb the dye to the inner leaflet of the vesicle after water efflux. Conversely, addition of SM to the vesicles barely modify the rate of calcein permeation across the bilayer.

Anemia del embarazo en la Provincia de Concepción, Chile: relación con el estado nutricional materno y el crecimiento fetal

Estudios realizados en Santiago han determinado que la anemia al inicio del embarazo es un problema de salud pública. No se conoce la situación en el resto del país. El propósito de este estudio fue establecer la prevalencia de anemia en mujeres embarazadas de la provincia de Concepción y evaluar su asociación con su estado nutricional y el crecimiento fetal de sus recién nacidos. Cumplieron con los requisitos de ingreso 1782 mujeres que iniciaron el año 2004 control prenatal en los centros de atención primaria del sistema de salud público de Concepción. La anemia se determinó con los criterios de la OMS (Hb < 11g / dl) y del Center for Disease Control de los Estados Unidos de América (CDC) (Hb < percentilo 5 para cada semana de gestación). Se comparó la presencia o ausencia de anemia con las variables independientes antropométricas maternoinfantiles, la prematurez y el puntaje Apgar del recién nacido, además de la edad, paridad, morbilidad y hábito tabáquico de la madre. Se realizó un análisis multivariado con regresión logística del posible efecto de la anemia en el crecimiento fetal. La prevalencia de anemia fue de 10,9% y de 14,5% según los criterios OMS y CDC, respectivamente. El estado nutricional de la madre se asoció significativamente con la anemia. Sin embargo, la anemia según OMS y CDC al inicio del embarazo no se asoció con el crecimiento fetal en el análisis multivariado. La anemia materna y es algo superior a la del estudio más reciente de Santiago.

Maternal anemia in Concepción province, Chile: association with maternal nutritional status and fetal growth. Previous studies in Santiago, Chile have established that anemia in the earliest stages of pregnancy is a public health issue. The situation in other parts of the country is unknown. The purpose of this study is to establish the prevalence of anemia in pregnant women in the province of Concepcion and evaluate its association with maternal nutricional status and fetal growth. The study included 1782 women with singleton pregnancies who began prenatal check-ups in 2004 at the public primary health care centers. Anemia was established using the following criteria: from WHO (Hb < 11g / dl) and from the USA Center for Disease Control (CDC) (Hb < percentile 5 for each gestational week). Anemia prevalence was compared in relation to independent study variables: maternal age, parity, morbidity and smoking habit, and mother and child anthropometry. A multivariable logistic regression model studied the possible effect of anemia on fetal growth. The prevalence of anemia was 10.9% and 14.5% using the WHO and CDC criteria, respectively. The mother’s nutritional status was significantly associated with anemia. However, anemia according to WHO and CDC criteria at the beginning of pregnancy was not significantly associated to fetal growth in the univariate and multivariate analyses. The prevalence of anemia in the province of Concepcion constitutes a public health problem that needs to be addressed and it is slightly higher to that recently observed in the county of Puente Alto, Santiago.

Effects of sodium valproate and carbamazepine on food competition aggression in pigeons.

Valproate and carbamazepine (CAR) have been proposed as adjunct alternatives for the control of aggression in psychiatric patients, although no definite conclusions have been reached. We examined the effects of these drugs on food competition offensive aggression and other behaviors in high- and low-aggression food-restricted pigeons. These were divided into pairs containing previously ranked high-aggression (N = 10 pairs) and low-aggression females (N = 10 pairs). In Experiment 1, a pigeon in each pair of high- and low-aggression subjects was treated daily with an oral dose of sodium valproate (50 mg kg-1 mL saline-1) for 15 days. The other animal received the vehicle. On days 1, 7, and 15, food competition trials (10 min) were performed 60 min after treatment. In Experiment 2, one pigeon in each pair was treated daily with an oral dose of CAR (20 mg kg-1 mL saline-1) for 15 days. Each pair was submitted to a food competition trial on days 1, 7, and 15 of treatment. Valproate (15 days of treatment) selectively decreased the time spent in offensive aggression (control: 102.7 +/- 9.3 vs valproate: 32.7 +/- 9.2 s; P < 0.001, ANOVA-2-TAU) of high-aggression pigeons. This was also the case for 7 and 15 days of CAR treatment (control: 131.5 +/- 8.9 vs CAR: 60.4 +/- 5.3, P < 0.01, and control: 122.7 +/- 7.1 vs CAR: 39.1 +/- 5.2; P < 0.001, ANOVA-2-TAU, respectively). Thus, the two anticonvulsive drugs have a similar effect on food competition aggression in pigeons.

Effects of sodium valproate and carbamazepine on food competition aggression in pigeons

Valproate and carbamazepine (CAR) have been proposed as adjunct alternatives for the control of aggression in psychiatric patients, although no definite conclusions have been reached. We examined the effects of these drugs on food competition offensive aggression and other behaviors in high- and low-aggression food-restricted pigeons. These were divided into pairs containing previously ranked high-aggression (N = 10 pairs) and low-aggression females (N = 10 pairs). In Experiment 1, a pigeon in each pair of high- and low-aggression subjects was treated daily with an oral dose of sodium valproate (50 mg kg-1 mL saline-1) for 15 days. The other animal received the vehicle. On days 1, 7, and 15, food competition trials (10 min) were performed 60 min after treatment. In Experiment 2, one pigeon in each pair was treated daily with an oral dose of CAR (20 mg kg-1 mL saline-1) for 15 days. Each pair was submitted to a food competition trial on days 1, 7, and 15 of treatment. Valproate (15 days of treatment) selectively decreased the time spent in offensive aggression (control: 102.7 ± 9.3 vs valproate: 32.7 ± 9.2 s; P < 0.001, ANOVA-2-TAU) of high-aggression pigeons. This was also the case for 7 and 15 days of CAR treatment (control: 131.5 ± 8.9 vs CAR: 60.4 ± 5.3, P < 0.01, and control: 122.7 ± 7.1 vs CAR: 39.1 ± 5.2; P < 0.001, ANOVA-2-TAU, respectively). Thus, the two anticonvulsive drugs have a similar effect on food competition aggression in pigeons.

Experiencia en pacientes neutropénicos febriles de alto y bajo riesgo, según el índice MASCC en linfoma no Hodgkin y leucemia aguda; en el Hospital Dr. Gustavo Fricke de Viña del Mar (2002-2005) / Experience in high and low risk patients with febrile neutropenia according to MASCC index in non Hodgkin lymphoma and acute leukaemia at Hospital Dr. Gustavo Fricke of Viña del Mar (2002-2005)

La neutropenia febril constituye una de las principales complicaciones en pacientes sometidos a quimioterapias con diagnóstico de linfoma no Hodgkin y leucemias agudas. Objetivos: describir las características de pacientes con neutropenia febril, clasificándolos en alto y bajo riesgo, según la probabilidad de presentar complicaciones médicas mayores, incluyendo la muerte, según un índice de riesgo validado de la MASCC (Multinational Association for Supportive Care in Cancer Risk Index). Pacientes y métodos: revisión de fichas de pacientes con linfoma no Hodgkin y leucemias agudas que presentaron episodios de neutropenia febril. Se recolectaron 51 episodios entre enero del 2002 y enero del 2005. Se les aplicó retrospectivamente el índice de riesgo diseñado por la MASCC. Resultados: el score de la MASCC aplicado retrospectivamente identificó los pacientes de bajo riesgo (27,5 por ciento del total), no presentándose en este grupo de pacientes complicaciones y muerte. La diferencia entre pacientes de alto y bajo riesgo no fue estadísticamente significativa (p>0.05) debido a que el total de pacientes era pequeño. Se describieron otras variables de ambos grupos. La diferencia en la pesquisa de focos infecciosos en los pacientes de alto riesgo (86.5 por ciento) con respecto a los de bajo riesgo (21.4 por ciento) fue estadísticamente significativa con un p<0.001. A ningún paciente se le administró terapia antibiótica profiláctica. El éxito del primer esquema antibiótico en pacientes de alto riesgo fue de 64.8 por ciento, mientras que en los de bajo riesgo el 100 por ciento respondió al primer esquema antibiótico aplicado. Los antibióticos que se utilizaron como primer esquema eran de espectro reducido, orientado al hallazgo clínico del foco o al microorganismo aislado. El aislamiento del agente infeccioso por hemocultivos en pacientes de alto riesgo fue de un 21.05 por ciento, mientras que en los de bajo riesgo alcanzó un 28.57 por ciento, predominando en ambos gr...

A phase II study of gemcitabine in gallbladder carcinoma.

BACKGROUND: Due to the high mortality rates from gallbladder carcinoma in Chile, we conducted a phase II trial to test the efficacy and safety of gemcitabine in patients with locally advanced or metastatic gallbladder carcinoma. PATIENTS AND METHODS: From January 1998 to February 2000, 26 patients with metastatic or unresectable gallbladder carcinoma and no prior chemotherapy received gemcitabine 1,000 mg/m2 over 30 minutes weekly for three weeks followed by a week of rest. RESULTS: Patients received a median of 4.2 cycles (range 1-10). Out of the 25 patients whose response could be evaluated, 9 went into partial remission, an overall response rate of 36% (95% confidence interval (95% CI): 17.1% to 57.9%). In six (25.0%) patients, the cancer remained stable, and in 10 (40%) it progressed. Median survival time was 30 weeks (range 7-80+. Hematological toxicities were mild, with no cases of febrile neutropenia or hemorrhage. However, four and one patient(s) had grades 1-2 and 3-4 neutropenia, respectively, and two patients had grade 2 thrombocytopenia. Nine patients experienced grade 1-2 nausea/vomiting, but were able to continue treatment. There were no toxic deaths. CONCLUSIONS: In this phase II trial, gemcitabine is an active chemotherapy in metastatic or inoperable gallbladder carcinoma, with a manageable toxicity profile.

Cytotoxic activity of Agave intermixta L. (Agavaceae) and Cissus sicyoides L. (Vitaceae).

The cytostatic activities of Agave intermixta L. (Agavaceae) and Cissus sicyoides L. (Vitaceae) have been determined. In the antimitotic assay, Agave intermixta L. showed complete inhibition of cell division at 24 h of treatment. Both species showed a moderate cytostatic activity against HEp-2 cells, Cissus sicyoides L. being the most active species.

Surface properties of lactobacilli isolated from healthy subjects.

OBJECTIVE: Lactobacilli are considered cariogenic micro-organisms. As oral species of lactobacilli have not been thoroughly described, the aim of this work was to isolated and identify these organisms from teeth, tongue, saliva and gum of healthy patients and to describe some of their surface properties. SUBJECTS: Forty-four subjects from Tucumán, Argentina, with D, d and M, m indices equal to 0. MATERIALS AND METHODS: Samples were obtained from different areas of the oral cavity. Microorganisms were cultured in lactobacilli selected media (LBS) and identified morphologically and biochemically. Hydrophobicity was analysed by partition in organic solvents, acidity by affinity with chloroform and basicity with ethyl acetate (MATH method), aggregation and coaggregation in presence of (NH4)2SO4, and haemagglutination with ABO erythrocytes in microplates. RESULTS: Eighty-five lactobacilli were isolated; 29.4% were homofermenter, 44.7% facultative heterofermenter and 25.9% obligate heterofermenter. Predominant species were L. fermentum, L. plantarum, L. salivarius, and L. rhamnosus. Most of the strains showed moderate to high hydrophobicity and demonstrated high acid and basic surface charges with almost 40% showing salt aggregation. Few strains haemagglutinated. CONCLUSIONS: A variety of Lactobacillus species were isolated from healthy mouths, some of whom showed adhesion-related properties such as high hydrophobicity and charged surfaces. Probable mechanisms related to the ecological behaviour of lactobacilli in the oral cavity are discussed.

[Efficacy of gemcitabine in the gallbladder cancer. Initial experience in 4 cases]. / Eficacia de gemcitabina en cáncer de vesícula biliar. Experiencia inicial en cuatro casos.

Surgery continues to be the only curative therapy for gallbladder cancer, but useful in very few patients. Mean survival of patients with gallbladder cancer, that are out of the reach of surgery, is 3 months. The few clinical trials of chemotherapy for this disease, report very low success rates. We report four patients with advanced gallbladder cancer, treated with gemcitabine in an intravenous dose of 1000 mg/m2, given in 30 min, once a week during three consecutive weeks, every 28 days. There was a partial response that lasted 40.3 23.2 weeks with a mean survival of 59.75 17 weeks. One patient survives without evidences of disease after 17 months of the diagnosis of an advanced cancer. In all patients, symptoms were alleviated, functional status and quality of life improved. Toxicity was mild and did not require reduction in doses or delay in therapy. Therefore, this medication deserves further investigation for the treatment of gallbladder cancer.

Changes in occipital cortex activity in early blind humans using a sensory substitution device.

The purpose of this study was to investigate the neural networks involved when using an ultrasonic echolocation device, which is a substitution prosthesis for blindness through audition. Using positron emission tomography with fluorodeoxyglucose, regional brain glucose metabolism was measured in the occipital cortex of early blind subjects and blindfolded controls who were trained to use this prosthesis. All subjects were studied under two different activation conditions: (i) during an auditory control task, (ii) using the ultrasonic echolocation device in a spatial distance and direction evaluation task. Results showed that the abnormally high metabolism already observed in early blind occipital cortex at rest [C. Veraart, A.G. De Volder, M.C. Wanet-Defalque, A. Bol, C. Michel, A.M. Goffinet, Glucose utilization in human visual cortex is, respectively elevated and decreased in early versus late blindness, Brain Res. 510 (1990) 115-121.] was also present during the control task and showed a trend to further increase during the use of the ultrasonic echolocation device. This specific difference in occipital cortex activity between the two tasks was not observed in control subjects. The metabolic recruitment of the occipital cortex in early blind subjects using a substitution prosthesis could reflect a concurrent stimulation of functional cross-modal sensory connections. Given the unfamiliarity of the task, it could be interpreted as a prolonged plasticity in the occipital cortex early deprived of visual afferences.

Auditory coding of visual patterns for the blind.

Recognition tasks of simple visual patterns have been used to assess an early visual--auditory sensory-substitution system, consisting of the coupling of a rough model of the human retina with an inverse model of the cochlea, by means of a pixel-frequency relationship. The potential advantage of the device, compared with previous ones, is to give the blind the ability to both localise and recognise visual patterns. Four evaluation sessions assessed the performance of twenty-four blindfolded sighted subjects using the device. Subjects had to recognise twenty-five visual patterns, one at a time, using a head-mounted small camera and interpreting the corresponding sounds given by the device. Half the subjects were trained by means of a correction feedback procedure during ten one-hour training sessions embedded in between the evaluation sessions. Results revealed extremely successful training effects. Performance of trained subjects significantly increased with practice compared with the untrained control group. The improvement was also observed for new patterns, demonstrating a learning-process generalisation. The negative correlation observed between scores and processing time showed that the subjects' response accuracy was related to their speed. In conclusion, simple pattern recognition is possible with a fairly natural vision-to-audition coding scheme, given the possibility for the subjects to have sensory--motor interactions while using the device.