Elevated brain derived neurotrophic factor in plasma and interleukin-6 levels in cerebrospinal fluid in meningitis compared to cerebral malaria.

Neurological infections, such as Cerebral malaria (CM) and meningitis are associated with high mortality and in survivors, particularly young children, persistent neurologic deficits often remain. As brain inflammation plays a role in the development of these neurological sequelae, multiplex assays were used to assess a select set of immune mediators in both plasma and cerebrospinal fluid (CSF) from Zambian children with neurological infections. Both CM and meningitis patients showed high levels of markers for vascular inflammation, such as soluble ICAM-1 and angiopoietins. Although high levels of angiopoietin 1 and angiopoietin 2 were found in the meningitis group, their levels in the CSF were low and did not differ. As expected, there were high levels of cytokines and notably a significantly elevated IL-6 level in the CSF of the meningitis group. Interestingly, although elevated levels BDNF were found, BDNF levels were significantly higher in plasma of the meningitis group but similar in the CSF. The striking differences in plasma BDNF and IL-6 levels in the CSF point to markedly different neuro-pathological processes. Therefore, further investigations in the role of both IL-6 and BDNF in the neurological outcomes are needed.

Relapse risk factors for patients with comorbid affective disorders and substance abuse disorders from an intensive treatment unit.

BACKGROUND AND OBJECTIVES: The prevalence of substance use disorders (SUD), particularly involving opiates and benzodiazepines, has increased to the detriment of public health and the economy. Here, we evaluate relapse factors among the high-risk demographic of patients with SUD and comorbid affective disorders. METHODS: A retrospective chart review of 76 patients discharged after detoxification and simultaneous psychiatric care for concomitant affective disorders and SUDs. Relapse was assessed by two independent evaluators via postdischarge chart review, which included state-wide healthcare utilization, by patient, through healthcare information exchange systems. A Cox Hazards analysis was performed to characterize relapse risk factors. RESULTS: Benzodiazepine use, admission through the emergency department (ED) rather than direct admission, frequent ED use in the preceding year, and history of prior attendance at multiple detoxification programs were risk factors for shortened time-to-relapse. Polysubstance use and intravenous drug use prolonged time to relapse. DISCUSSION AND CONCLUSIONS: Notable findings include the significant relapse risk associated with benzodiazepine abuse and frequent prior ED utilization. These risk factors could reflect a number of underlying mediators for relapse, including anxiety, disease burden, and malingering. Additionally, this study recapitulates the observation in other patient populations that the majority of health resource utilization is attributed to a small population of patients. SCIENTIFIC SIGNIFICANCE: This study is the first to identify relapse predictors among dual-diagnosis affective disorder and SUD patients in survival analysis, and replicates the alarming and largely unknown effect that benzodiazepines have on increasing relapse risk.

Cerebrospinal fluid in COVID-19 neurological complications: Neuroaxonal damage, anti-SARS-Cov2 antibodies but no evidence of cytokine storm.

OBJECTIVE: To study in cerebrospinal fluid (CSF) of COVID-19 subjects if a "cytokine storm" or neuroinflammation are implicated in pathogenesis of neurological complications. METHODS: Cross-sectional study of CSF neuroinflammatory profiles from 18 COVID-19 subjects with neurological complications categorized by diagnosis (stroke, encephalopathy, headache) and illness severity. COVID-19 CSF was compared with CSF from healthy, infectious and neuroinflammatory disorders and stroke controls (n = 82). Cytokines (IL-6, TNFα, IFNγ, IL-10, IL-12p70, IL-17A), inflammation and coagulation markers (high-sensitivity-C Reactive Protein [hsCRP], ferritin, fibrinogen, D-dimer, Factor VIII) and neurofilament light chain (NF-L), were quantified. SARS-CoV2 RNA and SARS-CoV2 IgG and IgA antibodies in CSF were tested with RT-PCR and ELISA. RESULTS: CSF from COVID-19 subjects showed absence of pleocytosis or specific increases in pro-inflammatory markers (IL-6, ferritin, or D-dimer). Although pro-inflammatory cytokines (IL-6, TNFα, IL-12p70) and IL-10 were increased in CSF of stroke COVID-19 subjects, a similar increase was observed in non-COVID-19 stroke subjects. Anti-SARS-CoV2 antibodies in CSF of COVID-19 subjects (77%) were observed despite no evidence of SARS-CoV2 viral RNA. CSF-NF-L was elevated in subjects with stroke and critical COVID-19 as compared to controls and other COVID-19 severity categories. CSF-hsCRP was present in all subjects with critical stages of COVID-19 (7/18) but only in 1/82 controls. CONCLUSION: The paucity of neuroinflammatory changes in CSF of COVID-19 subjects and lack of SARS-CoV2 RNA do not support the presumed neurovirulence of SARS-CoV2 or neuroinflammation in pathogenesis of neurological complications in COVID-19. The role of CSF SARS-CoV2 IgG antibodies and mechanisms of neuronal damage are still undetermined.

Increased synthesis of pro-inflammatory cytokines in C9ORF72 patients.

C9ORF72 hexanucleotide expansion is the most common genetic cause of familial amyotrophic lateral sclerosis (ALS)/fronto-temporal dementia (FTD) disease spectrum. Even though three major mechanisms of disease pathogenesis have been proposed, we lack detailed understanding of the factors that influence disease onset and progression. We sought to characterize cerebrospinal fluid and sera of C9ORF72 patients via a multiplex assay of 41 chemokines and cytokines in comparison to neurological controls and sporadic ALS patients. We found an increase in synthesis of pro-inflammatory chemokines and cytokines in disease samples and particularly in C9ORF72 patients in comparison to controls. We provide evidence that a CSF pro-inflammatory signature is a feature of C9ORF72-mediated disease.

Cerebrospinal fluid in COVID-19 neurological complications: no cytokine storm or neuroinflammation.

BACKGROUND: Neurological complications occur in COVID-19. We aimed to examine cerebrospinal fluid (CSF) of COVID-19 subjects with neurological complications and determine presence of neuroinflammatory changes implicated in pathogenesis. METHODS: Cross-sectional study of CSF neuroinflammatory profiles from 18 COVID-19 subjects with neurological complications categorized by diagnosis (stroke, encephalopathy, headache) and illness severity (critical, severe, moderate, mild). COVID-19 CSF was compared with CSF from healthy, infectious and neuroinflammatory disorders and stroke controls (n=82). Cytokines (IL-6, TNFα, IFNγ, IL-10, IL-12p70, IL-17A), inflammation and coagulation markers (high-sensitivity-C Reactive Protein [hsCRP], ferritin, fibrinogen, D-dimer, Factor VIII) and neurofilament light chain (NF-L), were quantified. SARS-CoV2 RNA and SARS-CoV2 IgG and IgA antibodies in CSF were tested with RT-PCR and ELISA. RESULTS: CSF from COVID-19 subjects showed a paucity of neuroinflammatory changes, absence of pleocytosis or specific increases in pro-inflammatory markers or cytokines (IL-6, ferritin, or D-dimer). Anti-SARS-CoV2 antibodies in CSF of COVID-19 subjects (77%) were observed despite no evidence of SARS-CoV2 viral RNA. A similar increase of pro-inflammatory cytokines (IL-6, TNFα, IL-12p70) and IL-10 in CSF of COVID-19 and non-COVID-19 stroke subjects was observed compared to controls. CSF-NF-L was elevated in subjects with stroke and critical COVID-19. CSF-hsCRP was present almost exclusively in COVID-19 cases. CONCLUSION: The paucity of neuroinflammatory changes in CSF of COVID-19 subjects and lack of SARS-CoV2 RNA do not support the presumed neurovirulence of SARS-CoV2 or neuroinflammation in pathogenesis of neurological complications in COVID-19. Elevated CSF-NF-L indicates neuroaxonal injury in COVID-19 cases. The role of CSF SARS-CoV2 IgG antibodies is still undetermined. FUNDING: This work was supported by NIH R01-NS110122 and The Bart McLean Fund for Neuroimmunology Research.

Juveniles of the overexploited Amazonian fish Colossoma macropomum (Characiformes: Serrasalmidae) as potential seed dispersers of Cecropia spp

Colossoma macropomum is a frugivorous fish from the Amazon and Orinoco river basins. This species has an important economic and social role in both river watersheds; it also has been overfished for more than 40 years, leading to changes in the populations structure. Currently adults are less common in fisheries, while juveniles are more frequently fished and sold in several market places along the Amazon River. Reportedly adult individuals consume a vast quantity of fruits and seeds and has been recognized as effective seed dispersers that plays a significant ecological role. Although frugivorous fishes are important dispersers in tropical rainforests, assessments of their effectiveness in dispersing seeds and in the effect on the germination of these ingested seeds are still insufficient. Cecropia latiloba and Cecropia membranacea are two pioneer tree species that initiate the succession process in the tropical forest and are both widely consumed by C. macropomum. In this study we aimed to verify if the Cecropia seeds that pass through the digestive tract of juveniles of C. macropomum would show improved germination. The results obtained through controlled experiments confirm that seeds that pass through the digestive tract of C. macropomum retained their germination capacity. Although the responses in the improvement of the germination variables (germination capacity, minimum imbibition time, time necessary for reaching 50 % germination capacity, emergence velocity index and germination mean time) did not show statistical differences between treatments, the seedlings that grew from the seeds consumed by the fish were taller than those without the digestive treatment. We conclude that juveniles of C. macropomum have the possibility to disperse the seeds of these Cecropia species.

Colossoma macropomum es un pez frugívoro de las cuencas del Amazonas y el Orinoco. Esta especie tiene un importante papel económico y social en ambas cuencas; sin embargo, ha sido sobreexplotada por más de 40 años, lo que ha llevado a cambios en la estructura de sus poblaciones. Actualmente los adultos son menos comunes en las pesquerías, mientras que los juveniles son atrapados y vendidos en varios mercados a lo largo del río Amazonas con mayor frecuencia. Se ha reportado que los individuos adultos consumen grandes cantidades de frutas y semillas, y han sido reconocidos como dispersores efectivos con un papel ecológico vital. A pesar de que los peces frugívoros son dispersores importantes en los bosques tropicales, los estudios sobre su efectividad en la dispersión de semillas y sobre la capacidad de germinación y la viabilidad de las semillas ingeridas son aún insuficientes. Cecropia latiloba y Cecropia membranacea son dos especies de árboles pioneros que inician el proceso de sucesión en los bosques tropicales; ambas son ampliamente consumidas por C. macropomum. El objetivo de este estudio fue verificar si las semillas de Cecropia que pasaron por el tracto digestivo de los juveniles de C. macropomum mejorarían su germinación. Los resultados obtenidos a través de experimentos controlados confirmaron que las semillas que pasan a través del tracto digestivo de C. macropomum mantienen su capacidad de germinar. Aunque las variables de germinación (capacidad de germinación, tiempo de imbibición mínimo, tiempo necesario para alcanzar el 50 % de la capacidad de germinación, índice de velocidad de emergencia y tiempo medio de germinación) no mostraron diferencias estadísticas entre tratamientos, las plántulas que crecieron de las semillas consumidas por los peces crecieron más que aquellas provenientes de semillas no ingeridas. Concluimos que los juveniles de C. macropomum tienen la posibilidad de dispersar las semillas de estas especies de Cecropia.

Black Fly (Diptera: Simuliidae) Assemblages of High Andean Rivers Respond to Environmental and Pollution Gradients.

Simuliid larvae are common inhabitants of mountain rivers throughout the world, where they can serve as ecological indicators. Black flies were sampled during three seasons in four rivers in the upper basin of the Bogotá River in the Colombian Andes, and physical, chemical, and hydrological data were recorded. Multivariate methods were used to determine the relationships between the presence and abundance of simuliid species and environmental characteristics. Fourteen species were found: eight in the genus Gigantodax (Enderlein, Diptera, Simuliidae) and six in the genus Simulium (Latreille, Diptera, Simuliidae). Dissolved oxygen, dissolved solids, redox potential, chemical oxygen demand, and nutrients contributed to an explanation of species distributions. Species in clean waters and in more polluted waters had narrow niches; those in low to moderately polluted waters had broader niches. Species in the lower reaches of the watercourses had greater turnover, perhaps because the most sensitive species had disappeared and been replaced by more tolerant species. Thus, simuliids can be used as predictors of environmental characteristics of Andean rivers and can be useful in the evaluation and management of these watersheds.

Trauma Craneoencefálico por Proyectil de Arma de Fuego: Revisión Temática / Traumatic brain injury (TBI) by a firearm projectile: thematic review / Traumatismo cranioencefálico por projétil de arma de fogo: revisão temática

Resumen El trauma craneoencefálico (TCE) por proyectil de arma de arma de fuego (PAF) es una condición severa producida por alteraciones mecánicas sobre el encéfalo. En Colombia, uno de cada cinco homicidios se produce a nivel craneal. Objetivo: Realizar una revisión de la literatura para identificar los aspectos médico-legales y clínico-quirúrgicos del TCE por PAF. Metodología: Revisión realizada por medio de búsqueda en bases de datos de literatura médica y recopilación de datos publicados por entidades gubernamentales. Resultados: El TCE por PAF, es un evento epidemiológicamente constante, cuyos patrones se relacionan con la presencia de conflictos armados. Se asocia con manifestaciones clínicas y complicaciones severas asociadas con variables como el tipo de arma y munición, sexo de la víctima, región principal de lesión y mecanismo de muerte. La mortalidad de este evento es muy alta si no se realiza intervención quirúrgica; y de hacerlo, las lesiones determinan la reducción de la expectativa y calidad de vida. Conclusión: El conflicto armado actual de Colombia, hace del TCE por PAF un tema de importancia criminológica, criminalística y médico-legal.

Abstract Traumatic brain injury (TBI) caused by a firearm projectile (FAP) is a severe condition produced by mechanical alterations on the encephalon. In Colombia, one in every five killings is produced at cranial level. Objective: to do a literature review to identify the medical-legal and clinic-surgical issues of TBI by FAP. Methodology: a review conducted by means of medical literature databases searching and data gathering published by governmental entities. Results: TBI by FAP is an event epidemiologically constant; and its standards are related to the presence of the armed conflicts. It is associated with clinical manifestations and severe medical complications connected with diverse variables such as type of weapons and ammunition, sex of the victims, main region of the lesion and death mechanism. If the surgical operation is not performed, the mortality in this event is very high, but if the surgery is carried out, the lesions determine the decrease of life expectancy and quality. Conclusion: the current Colombian armed conflict makes TBI by FAP a topic of criminological, criminalistics and medical-legal relevance.

Resumo O Traumatismo Cranioencefálico (TCE) por Projétil de Arma de Fogo (PAF) é uma condição severa causada por alterações mecânicas sobre o encéfalo. Na Colômbia, um em cada cinco homicídios é producido na zona craniana. Objetivo: realizar uma revisão de literatura para identificar os aspectos médico-legais e clínico-cirúrgicos do TCE por PAF. Metodologia: revisão realizada por meio de busca em bases de dados da literatura médica e coleta de dados publicados por entidades governamentais. Resultados: o TCE por PAF é um evento epidemiologicamente constante, cujos padrões relacionam-se à presença de conflito armado. Associa-se a manifestações clínicas e complicações graves vinculadas a diversas variáveis, como o tipo de arma e munição, sexo da vítima, lugar principal da lesão e mecanismo da morte. A mortalidade, decorrente desse evento, é muito alta caso não seja realizada intervenção cirúrgica. No pós-cirúrgico, as lesões determinam a redução da expectativa e da qualidade de vida. Conclusão: o conflito armado atual na Colômbia faz do TEC por PAF um tema de importancia criminológica, criminalística e médico-legal.

Current Knowledge Status on Periphyton Algae and Benthic Macroinvertebrates of The Meta Region, Colombia / Estado actual del conocimiento sobre microalgas del perifiton y macroinvertebrados bentónicos en el departamento del meta, colombia

RESUMEN El departamento del Meta cuenta con un elevado potencial hidrológico que se traduce en oportunidades para los sectores agrícola, pecuario y ambiental. Por otra parte, se han incrementado considerablemente las actividades de la industria petrolera, lo cual ha traído nuevos retos y amenazas a la región. En consecuencia, los ríos del departamento se ven afectados por vertimientos de diferentes tipos, por captaciones y por modificaciones de los entornos de ribera y de los ambientes bentónicos. Sin embargo, es poco lo que se conoce acerca de estos sistemas y de las comunidades de microalgas y macroinvertebrados que los habitan, las cuales cumplen un papel fundamental en el funcionamiento ecológico de los ríos. Por esta razón se analizan las características más relevantes de dichas comunidades y se discuten las modificaciones que las actividades humanas provocan sobre la estabilidad ecológica de los ríos en un contexto regional. Adicionalmente, se presenta un listado de los taxones de microalgas perifíticas y macroinvertebrados bentónicos registrados para el departamento del Meta.

ABSTRACT Nowadays the Meta Department has a high hydrological potential, which results in an opportunity for agriculture and livestock. Moreover, activities of the oil industry have significantly increased, which have brought new challenges and threats to the region. Consequently, different types of discharges and environment modifications affect the Meta Region's rivers in their watersheds and their riparian and benthic communities. However, these systems are poorly understood, including the periphyton and macroinvertebrate communities that inhabit them. In this paper, we provide a review of the most relevant characteristics of these communities, and we discuss the changes caused by human activities on the ecological stability of the rivers in a regional context. Additionally, we presented a list of periphytic algae and benthic macroinvertebrates taxa registered in the Meta Region.

Ecological characterization of Aedes aegypti larval habitats (Diptera: Culicidae) in artificial water containers in Girardot, Colombia.

The establishment of habitats for immature Ae. aegypti is regulated by biotic and abiotic factors and interactions between these factors. This study aimed to determine the effects of physico-chemical variables and planktonic algae on immature Ae. aegypti habitats in 101 water tanks (50 of them containing Ae. aegypti pupae and/or larvae) in Girardot, Colombia. Physical data were collected from the water tanks (volume, capacity, material, detritus, and location), along with the physico-chemical variables (temperature, pH, conductivity, redox potential, dissolved oxygen, percentage of oxygen saturation, nitrates, nitrites, and orthophosphates). The richness and abundance of the planktonic organisms were also measured. A chi-square test showed that the occurrence of detritus was greater and the container volume was smaller in the tanks that were positive for larvae. Only Cyanobacteria had a positive correlation with the abundance of immature-stage Ae. aegypti. The results could be important for understanding the vector ecology and envisaging its probable control in the domestic water tanks of Girardot.

Variación diurna de la talla en una población de adultos jóvenes colombianos / Diurnal variation of height in a Colombian young adult population

Los cambios en la talla corporal a lo largo del día tras la bipedestación son procesos poco conocidos, aun en el escenario de la morfología. Este estudio evaluó la variación de la talla a lo largo del día en una muestra de población joven colombiana. Mediante un muestreo aleatorio estratificado por asignación proporcional se evaluó la variación de la talla corporal a lo largo del día en 55 sujetos jóvenes. Se tomaron cuatro mediciones de talla durante un día, usando para ello un tallímetro convencional. Se realizó análisis estadístico de los resultados mediante pruebas de concordancia (CCI). La edad promedio de los sujetos evaluados fue de 19,5±1,86 años, de los cuales 22 (40%) fueron del sexo masculino. La talla y peso promedio fueron 167,1±8,59 cm y 65,8±14,5 Kg, respectivamente. La pérdida media de altura al final del día fue 9,4±3,12 mm; la pérdida en las mujeres fue de 9,72±3,35 mm y en los hombres 8,95±2,76 mm sin que esa diferencia fuese significativa (p=0,22). No se identificó asociación entre peso mayor a 78 Kg y pérdida de talla en el día mayor a 1 cm (p=0,18). En la franja de 06:00­10:00 horas ocurrió la mayor disminución de la talla, el 60%; mientras que de 10:00­14:00 horas la disminución fue 10%, y del 30% de 14:00­18:00 horas. La pérdida de talla observada en este estudio es ligeramente inferior a lo reportado en estudios previos. El conocimiento de la variación diaria de la talla corporal debe tenerse en cuenta en el planeamiento de los controles de crecimiento infantil.

Changes in height throughout the day after standing are poorly understood, even in morphological sciences. This study evaluated height variations throughout the day in a sample of young Colombian population. Using a stratified random sampling with proportional allocation, diurnal changes in height was evaluated in 55 subjects. Four measurements of size were taken over a day, using a conventional measurer for it. Statistical analysis of the results was performed by testing agreement (ICC). The average age of the subjects tested was 19.5±1.86 years, of which 22 (40%) were male. The average height and weight were 167.1±8.59 cm and 65.8±14.5 Kg respectively. The average loss of height after the day was 9.4±3.12 mm loss in women was 9.72±3.35 mm and 8.95±2.76 mm in men but this difference was not significant (p=0.22). Statistically significant association between weight >78 Kg and height loss in the day >1cm (p=0.18) was not identified. In the range of 06:00 to 10:00 hours came up with the greatest reduction in size, 60%; while from 10:00 to 14:00 hours the decrease was 10% and 30% of 14:00­18:00 hours. Height loss observed in this study was just below that reported in the literature. The knowledge of the changes in height throughout the day should be taken in consideration when diagnosing growth pathologies.

Relaciones entre las abundancias del bacterioplancton y del fitoplancton en tres ecosistemas lénticos de los Andes Colombianos / Relations between bacterioplankton and phytoplankton abundance in three lentic ecosystems in the Colombian Andes

We analyzed relations among phytoplankton and total bacterioplankton fractions in three lentic ecosystems (Neusa and Prado dams, and Fúquene lagoon) with different physicochemical characteristics, in the Andes of Colombia. Samplings were made in three sites of each water body during three surveys. Neusa dam (meso to oligotrophic) had the lowest bacterial concentration; Prado dam (eutrophic) had a high bacterial and algal abundance, and the Fúquene lagoon (mesotrophic) had lower concentrations of phytoplankton but a high relative concentration of bacteria, probably because of its particular conditions: high organic matter and low nutrient levels in the water. There was a negative correlation of total bacterioplankton with the phytoplankton (Pearson = -0.4479, p = 0.019, n=27) and a positive correlation between phytoplankton and heterotrophic bacteria (Pearson = 0.3866, p = 0.062, n=24) and between total bacterioplankton and DBOs (Pearson = 0.4088, p = 0.034, n=27). Apparently, total bacterioplankton and phytoplankton were not coupling, but cultivable bacteria and the phytoplankton had some degree of relationship.

[Relations between bacterioplankton and phytoplankton abundance in three lentic ecosystems in the Colombian Andes]. / Relaciones entre las abundancias del bacterioplancton y del fitoplancton en tres ecosistemas lénticos de los Andes Colombianos.

We analyzed relations among phytoplankton and total bacterioplankton fractions in three lentic ecosystems (Neusa and Prado dams, and Fúquene lagoon) with different physicochemical characteristics, in the Andes of Colombia. Samplings were made in three sites of each water body during three surveys. Neusa dam (meso to oligotrophic) had the lowest bacterial concentration; Prado dam (eutrophic) had a high bacterial and algal abundance, and the Fúquene lagoon (mesotrophic) had lower concentrations of phytoplankton but a high relative concentration of bacteria, probably because of its particular conditions: high organic matter and low nutrient levels in the water. There was a negative correlation of total bacterioplankton with the phytoplankton (Pearson = -0.4479, p = 0.019, n=27) and a positive correlation between phytoplankton and heterotrophic bacteria (Pearson = 0.3866, p = 0.062, n=24) and between total bacterioplankton and DBOs (Pearson = 0.4088, p = 0.034, n=27). Apparently, total bacterioplankton and phytoplankton were not coupling, but cultivable bacteria and the phytoplankton had some degree of relationship.

Growth, feeding and reproduction of the catfish Eremophilus mutisii (Pisces: Trichomycteridae), from artificial reservoirs in Colombia

The catfish, Eremophilus mutisii, was cultured under different densities in artificial rainfall reservoirs at Caldas, Boyacá, Colombia. At capture, the average total length of the animals was 10 cm and the weight ranged between 9 and 10 g. These fish were in initial stages of sexual development. After a year in the reservoirs, they had increased in length and weight as follows (densities in parentheses): 5.22 cm and 27.23 g (0.5 individuals/m2); 1.98 cm and 8.79 g (1 individual/m2), and 2.45 cm and 0.82 g (2 individuals/m2). They were at the early stages of sexual maturity, and their condition factor fluctuated between 0.61 and 0.96. They preferably ingested insect larvae that were found in benthic and littoral communities of the reservoirs. The benthos was dominated by ephippia of Daphnia, lumbriculids, and chironomid larvae. The biomass of benthic organisms ranged between 0.1126 and 1.3847 g/m2. In the littoral community aquatic insects were the most important component, especially the hemipterans. The biomass of the littoral fauna ranged between 0.14 and 4.05 g/m2.

El “capitán de la sabana”, Eremophilus mutisii (Humboldt, 1805), fue cultivado en diferentes densidades en pequeños lagos artificiales localizados en Caldas, Boyacá, Colombia. Al inicio, el promedio de la longitud corporal fue 10 cm y el peso osciló entre 9 y 10 gr. Los peces se encontraban en estados iniciales de desarrollo sexual. Luego de un año de experimentación, los peces cultivados a una densidad de 0.5 ind/m2 incrementaron 5.22 cm en longitud y 27.23 gr en promedio (1 ind/m2: 1.98 cm y 8.79 gr; 2 ind/m2: 2.45 cm y 0.82 gr). Los peces se encontraban iniciando su madurez sexual, y su factor de condición fluctuó entre 0.61 y 0.96 y consumían principalmente larvas de insectos. El bentos estaba dominado por efipios de Daphnia, lumbricúlidos y larvas de quironómidos. La biomasa de organismos benticos osciló entre 0.1126 y 1.3847 gr/m2. En la comunidad litoral, los insectos acuáticos fueron los componentes mas importantes, especialmente los hemípteros. La biomasa de la fauna litoral osciló entre 0.14 y 4.05 gr/m2.

Growth, feeding and reproduction of the catfish Eremophilus mutisii (Pisces: Trichomycteridae), from artificial reservoirs in Colombia.

The catfish, Eremophilus mutisii, was cultured under different densities in artificial rainfall reservoirs at Caldas, Boyacá, Colombia. At capture, the average total length of the animals was 10 cm and the weight ranged between 9 and 10 g. These fish were in initial stages of sexual development. After a year in the reservoirs, they had increased in length and weight as follows (densities in parentheses): 5.22 cm and 27.23 g (0.5 individuals/m2); 1.98 cm and 8.79 g (1 individual/m2), and 2.45 cm and 0.82 g (2 individuals/m2). They were at the early stages of sexual maturity, and their condition factor fluctuated between 0.61 and 0.96. They preferably ingested insect larvae that were found in benthic and littoral communities of the reservoirs. The benthos was dominated by ephippia of Daphnia, lumbriculids, and chironomid larvae. The biomass of benthic organisms ranged between 0.1126 and 1.3847 g/m2. In the littoral community aquatic insects were the most important component, especially the hemipterans. The biomass of the littoral fauna ranged between 0.14 and 4.05 g/m2.

Evaluación de la eficiencia fotosintética del fitoplancton en un lago amazónico (Lago Boa) y en un lago andino (Lago Guatavita) / Evaluation of the phytoplanktonic photosynthetic efficiency in an Amazon Lake (Lake Boa) and in an Andean Lake (Lake Guatavita)

La relación entre la fluorescencia variable y la fluorescencia máxima (Fv/Fm) de las comunidades de algas se ha utilizado comúnmente como una medida de la eficiencia fotosintética del fitoplancton. Dicha eficiencia puede estar afectada por la localización de los ambientes acuáticos en distintas provincias limnológicas. En este trabajo se quiso establecer la diferencia en la relación Fv/Fm entre el lago Boa (150 msnm, Amazonía colombiana) y el lago Guatavita (3000 msnm, cordillera oriental de los Andes colombianos). Los promedios de las eficiencias medidas fueron en general bajos (0,212 a 0,367 y 0,089 a 0,32 en los lagos Boa y Guatavita, respectivamente), lo que señala estrés fisiológico para las algas. La eficiencia fue mayor en aguas intermedias y presentó cambios fuertes entre épocas de muestreo y entre ecosistemas. En aguas superficiales se presentó fotoinhibición, la cual fue más fuerte en Guatavita. La eficiencia fotosintética fue menor en el lago andino debido posiblemente a diferencias climáticas, de altura sobre el nivel del mar y de estratificación. Durante los ensayos de laboratorio se observó que la eficiencia disminuyó con el tiempo, lo cual pudo deberse a una aclimatación de las algas a la oscuridad. Los datos de laboratorio confirmaron que el fitoplancton epilimnético del lago Guatavita estuvo fotoinhibido en la época de estratificación.

Commonly relation between variable fluorescence and maximum fluorescence (Fv/Fm) of the algae community has been utilized like a measure of the phytoplanktonic photosynthetic efficiency. Such efficiency can be affected by the water bodies' location in different limnological provinces. The goal of this work was to establish the differences in the Fv/Fm rate between Lake Boa (150 masl Colombian Amazon) and Lake Guatavita (3000 masl, East Range in the Colombian Andes). In general, averages of the photosynthetic efficiencies were low (0.212 to 0.367 and 0.089 to 0.32 in lakes Boa and Guatavita, respectively), which indicate physiological stress to algae. Efficiency was higher in middle waters and changed strongly between sample periods and ecosystems. Photoinhibition occurred in superficial waters was greater in Lake Guatavita. Photosynthetic efficiency was smaller in the Andean lake do possibly to climatic differences, elevation above sea level and stratification. During laboratory assays efficiency decreased along time, caused probably by the darkness adaptation of the algae. Laboratory data confirmed that epilimnetic phytoplankton of the Lake Guatavia was photoinhibited at the stratification period.

Citología por aspiración de nódulos mamarios / Aspiration cytology of breast nodules

Durante año y medio, se estudiaron 205 pacientes con nódulos mamarios que asistieron a la consulta de seno del Hospital González Valencia y Liga de Lucha contra el Cáncer, a los cuales se les practicó una citología por aspiración del nódulo, utilizando una jeringa desechable con aguja n§ 20. Se descartaron los pacientes con lesiones quísticas, quedando 120 casos para el estudio. Sus resultados se compararon con el diagnóstico definitivo dado por la histopatología de la pieza quirúrgica extirpada. En general se obtuvo una correlación del 87%, con unos falsos negativos del 19% y falsos positivos del 7.4%. La sensibilidad de la prueba fue del 86.2% y la especificidasd del 89.5%. No hubo complicaciones con el procedimiento. Concluimos que es recomendable la práctica de la citología por aspiración en todo nódulo mamario, previo a cualquier otro estudio, dada su confiabilidad, simplicidad y bajo costo