Patterns of ant (Hymenoptera: Formicidae) richness and relative abundance along an aridity gradient in Western Venezuela.

In xeric ecosystems, ant diversity response to aridity varies with rainfall magnitude and gradient extension. At a local scale and with low precipitation regimes, increased aridity leads to a reduction of species richness and an increased relative abundance for some ant species. In order to test this pattern in tropical environments, ant richness and relative abundance variation were evaluated along 35 km of an aridity gradient in the Araya Peninsula, state of Sucre, Venezuela. Three sampling stations comprising five transects each were set up. Pitfall traps and direct collecting from vegetation were assessed per transect. Overall, 52 species, 23 genera, and 7 subfamilies of ants were recorded in the peninsula. The total number of species and genera recorded by both sampling stations and transects decreased linearly with increasing aridity. Total relative abundance was highest in the most arid portion of the peninsula, with Crematogaster rochai (Forel) and Camponotus conspicuus zonatus (Emery) (Hymenoptera: Formicidae) being the numerically dominant species. Spatial and multivariate analyses revealed significant changes in ant composition every 11 km of distance, and showed a decrease of ant diversity with the increase of harsh conditions in the gradient. Here, we discuss how local geographic and topographic features of Araya originate the aridity gradient and so affect the microhabitat conditions for the ant fauna.

Influencia del concentrado de plaquetas sobre la reconstrucción de defectos de cartílago articular en la rodilla de cordero / Influence of concentrated platelets on the reconstruction of cartilage defects in the lamb knee joint

Objetivo. Analizar el efecto de las plaquetas sobre el crecimiento de cartílago en los defectos articulares provocados en la rodilla ovina. Material y método. Se provocó un defecto de 4mm de diámetro y 3mm de profundidad en la tróclea femoral de ambas rodillas en corderos macho de 6 meses de edad. La distribución de los grupos fue: grupo A (n=6): el defecto de la rodilla derecha se rellenó con concentrado de plaquetas 5min después de ser activado con ClCa. Grupo B (n=6): el defecto se rellenó con colágeno y plaquetas. Material y método. Las plaquetas se obtuvieron por centrifugación de 10ml de sangre arterial obtenida de cada animal antes de la cirugía. En los defectos de la rodilla izquierda no se administraron plaquetas. Las ovejas fueron sacrificadas 10 semanas después de la cirugía. Se realizaron estudios macro y microscópicos. Resultados. En el grupo A, se observó cartílago hialino en 4 de los defectos de la rodilla derecha a las 10 semanas de la cirugía. Ninguno de los defectos de la rodilla izquierda mostró crecimiento de cartílago hialino. En el grupo B, no se observó cartílago hialino en nigún defecto. No obstante, todos los defectos presentaron mejor celularidad condral y menor fibrosis en los defectos tratados con plaquetas que en los no tratados. Conclusiones. Esta técnica para la reconstrucción con plaquetas de defectos articulares de oveja ha mostrado en nuestro estudio resultados esperanzadores que empeoran combinadas con un andamiaje de colágeno (AU)

Objective. To study the influence of platelets on cartilage growth in articular defects in the sheep knee. Material and methods. Male Rasa Aragonesa sheep (6 months) were operated under general anaesthesia. A 4mm diameter and 3mm deep defect was made in the femoral trochlea in both knees. The right knee defect was filled with platelet concentrate 5min after being activated with ClCa in group A (n=6), and similarly activated platelets + collagen scaffold in group B (n=6). Platelets were obtained by centrifuging 10ml arterial blood from the sheep prior to the surgical procedure. The left knee defect was not filled. The sheep were sacrificed 10 weeks after surgery. Macroscopic and microscopic studies were performed. Results. In group A, hyaline cartilage was observed in the right knee defect at the end of the experiment in four cases. None of the defects of the left knees showed hyaline cartilage growth. In group B, hyaline cartilage was not observed in any right knee defect. However, in group B, all sheep showed better chondral cellularity and regeneration and lower fibrosis in the defects treated with platelets than in non-treated ones. Conclusions. This technique for articular defect reconstruction with platelets has shown satisfactory results in our study. However, collagen scaffolds may decrease this positive effect (AU)

Animal experience in the Günther Tulip retrievable inferior vena cava filter.

PURPOSE: To assess the retrievability of the Günther Tulip temporary inferior vena cava filter from a technical viewpoint, and consider the histopathologic changes that occur at the anchoring site of the filter prongs to the vein endothelium in Landrace pigs. METHODS: Twenty-two Günther Tulip retrievable filters were inserted in 22 experimental Landrace pigs via the jugular vein. Device implantation time was 0, 3, 7, 12, 14, 15, 16, 20, 30, 35 and 56 days. Study subjects were divided into two groups. In one group the filter was retrieved percutaneously via the jugular vein whereas in the other group it was removed surgically. The specimens obtained (vena cava and filter) were histopathologically examined. Prior to filter retrieval, a venacavography was obtained in all cases. Degree of retrieval difficulty was rated as follows: no difficulty (N), slight (S), mild (M), high (H) and unretrievable (U). RESULTS: Of the 22 implanted filters, 11 should have been removed percutaneously but this was impossible in three cases (U). In four cases the device was retrieved with no difficulty (N); in two cases the degree of difficulty was mild (M) and in other two it was high (H) and slight (S) respectively. Retrieval difficulties were observed after 16 days. Starting from day 20, there was evidence of fibrosis with thick intimal proliferation and total filter prong involvement, which accounts for the difficulty in retrieving the device. CONCLUSIONS: It is advisable not to exceed a filter retrieval time of 16 days in view of the fibrotic changes reported. It might be necessary to perform a larger study with more animals and with retrieval times between 14 and 20 days.

Utility of the Technicon H-1 flags in the detection of peripheral blood blast cells of paediatric acute leukaemia patients.

This study evaluates the sensitivity and positive predictive value of some of the morphological flags supplied by the Technicon H-1 haematological analyser to detect circulating blasts. A total of 1,269 venous blood samples from 91 paediatric patients diagnosed of acute leukemia were analysed in the Technicon H-1. A conventional microscopic manual method was used for reference. The prevalence was 17.7% for the presence of blasts. The results showed that all samples with more than 5% blasts were detected by some WBC morphological flag: only 5 samples (2.2%) with less than 5% blasts showed no morphological flag. In most cases (86%), the flags observed were either the 'Atyp' flag or the 'Blast' flag or both simultaneously. The positive predictive value obtained by the 'Blast' flag for the true presence of blasts was 66.8%, and for the 'Atyp' flag 34.9%; it was 75.8% when both flags were present simultaneously. False positives were associated with postchemotherapy monocytosis or severe neutropenia.

[Evaluation of the Coulter STKS hematologic autoanalyzer]. / Valoración del autoanalizador hematológico Coulter STKS.

PURPOSE: To express the results of an evaluation of the Coulter STKS blood cell counter. MATERIAL AND METHODS: The following data were collected: inaccuracy, carry-over, linearity, comparison with other systems, suspect morphology alarms, stability of calibration, time-stability of samples and working velocity. The protocol recommended by the ICSH was followed for the first four of the above. RESULTS: Good results were achieved for cell counts and derived parameters. The leucocyte differential count showed fair results for neutrophils, lymphocytes, monocytes and eosinophils; false basophilia was usually associated with the presence of abnormal lymphocytes. No differences were found between adult and paediatric samples. The usefulness of the suspect morphology alarms was also evaluated; they were found fairly sensitive for the presence of stabs, large amounts of atypical lymphocytes and blast cells, and moderately sensitive for erythroblasts and platelet clumps. The predictive value of alarms was found high in any type of pathology, but scarcely valuable when considering the pathology indicated by the alarm, such predictive value being noticeably increased upon associated alarms. CONCLUSION: The Coulter STKS cell counter appears as adequate for the haematology laboratory running daily high number of samples with high pathologic rates.

[Evaluation of the Sysmex NE-8000 hematologic autoanalyzer]. / Evaluación del autoanalizador hematológico Sysmex NE-8000.

The results of an evaluation of the Sysmex NE-8000 cell counter are reported. Good results were attained for all values of red and white cell counts. Platelet values were good as well, although samples with thrombocytosis were overstated to some extent. Fair results were found for the white-cell differential count concerning neutrophils, eosinophils and lymphocytes, but false monocytosis were frequently seen in paediatric blood samples, whereas some monocytosis were undetected. The alarms for suspected pathology had only moderate sensitivity when used as the only criterion. The predictive value of such alarms was low, except for the "platelet clumps?" sign.

Transitory T-lymphoblastic leukemoid reaction in a neonate with Down syndrome.

A transient leukemoid reaction in a neonate with Down syndrome is reported. The blastic proliferation was identified as T lymphoblastic in an early stage of maturation (prethymocytes) using morphological, cytochemical, and immunological methods. A spontaneous complete remission occurred in 8 weeks. No additional cytogenetic alterations were found, except for those concerning chromosome 21. Other cases reported in the literature reveal that cytogenetic studies may be useful to distinguish these transient leukemic reactions from true leukemias in newborns with Down syndrome. The in vitro growth pattern of peripheral blood and bone marrow may also be useful for this purpose.

[Evaluation of a totally automated alternative system for determining the rate of erythrocyte sedimentation]. / Valoración de un sistema alternativo totalmente automatizado para la determinación de la velocidad de sedimentación globular.

The Ves-MaticR system (VS) for evaluating erythrocyte sedimentation rate (ESR) is compared to Westergren method. A good correlation between both methods is obtained in spite of small differences observed; the accuracy of the VS is also studied. Concerning the time variation, a small reduction of the ESR in the first seven hours is observed, being significant at 24 hours. The most important advantages of the VS are the near complete disappearance of the contamination risk, the reduction of the time employed in setting up, sedimentation and reading, and the reliability.

Hereditary myeloperoxidase deficiency: study of 12 cases.

12 cases of hereditary myeloperoxidase (MPO) deficiency are reported. Histochemical stainings, lysosomal enzyme determinations, electron microscopic study of MPO and granulocytic function were performed. Family studies on 2 generations were carried out in 5 patients and histochemical stainings and biochemical lysosomal enzyme determinations were done. MPO deficiency was found to follow autosomal recessive inheritance and only rarely to have clinical effects.

Resultados con el tratamiento normativo de la hipertension inducida por el embarazo. / Results with the normative treatment of hypertension induced by pregnancy

Se hizo un analisis del manejo de las pacientes con hipertension inducida por el embarazo durante 4 anos en este hospital.El porcentaje global fue de 2,94% en 22.730 partos. La incidencia de pre-eclampsia fue de 2,86% y 0,07% de eclampsia. Hubo predominio de pacientes primegestas y entre los 21 y 25 anos de edad. El porcentaje de prematuridad fue alto, 19,02%, sobre todo en las pre-eclampsias severas. El uso de la cesarea fue liberal, 21,62%, sobre todo en las severas. El manejo de la paciente uniforme, siendo lo principal el reposo, la dieta normosodica, antihipertensivos, sulfato de magnesio e interrupcion del embarazo en los casos severos que no respondian al tratamiento. No se uso diureticos. La mortalidad perinatal fue de 3%. Hubo una muerte materna

[Liver abscess. Diagnosis by the method of opacification]. / Absceso hepático. Diagnóstico por el método de la opacificación.

A 15 min infusion of a 75% iodized solution at 2 cc/k-w produces opacification of the more vascularized organs; hypovascular, necrotic or cystic regions are thus of a different radiological density. In order to show the usefulness of this method in diagnosing a hepatic abscess quickly and topographically, it was applied in 13 cases which had been diagnosed as invading amoebiasis. Hepatography proved to be the most valuable. Positive findings are observed 5 to 7 min after infusion has been completed. The greater density at the edge of the abscess enables its diameter to be measured and the liquid content to be calculated fairly accurately.