Candidate Interneurons Mediating the Resetting of the Locomotor Rhythm by Extensor Group I Afferents in the Cat.

Sensory information arising from limb movements controls the spinal locomotor circuitry to adapt the motor pattern to demands of the environment. Stimulation of extensor group (gr) I afferents during fictive locomotion in decerebrate cats prolongs the ongoing extension, and terminates ongoing flexion with an initiation of the subsequent extension, i. e. "resetting to extension". Moreover, instead of the classical Ib non-reciprocal inhibition, stimulation of extensor gr I afferents produces a polysynaptic excitation in extensor motoneurons with latencies (∼3.5-4.0 ms) compatible with 3 interposed interneurons. We assume that some interneurons in this pathway actually belong to the rhythm-generating layer of the locomotor Central Pattern Generator (CPG), since their activity was correlated to a resetting of the rhythm. In the present work fictive locomotion was (mostly) induced by i.v. injection of nialamide followed by l-DOPA in paralyzed cats following decerebration and spinalization at C1 level. In some experiments, we extended previous observations during fictive locomotion on the emergence and locomotor state-dependence of polysynaptic excitatory postsynaptic potentials from extensor gr I afferents to ankle extensor motoneurons. However, the main focus was to record location and properties of interneurons (n = 62) that (i) were active during the extensor phase of fictive locomotion and (ii) received short-latency excitation (mono-, di- or polysynaptic) from extensor gr I afferents. We conclude that the interneurons recorded fulfill the characteristics to belong to the neuronal pathway activated by extensor gr I afferents during locomotion, and may contribute to the 'resetting to extension' as part of the locomotor CPG.

[Presence of malnutrition and risk of malnutrition in institutionalized elderly with dementia according to the type and deterioration stage]. / Presencia de malnutrición y riesgo de malnutrición en ancianos institucionalizados con demencia en función del tipo y estadío evolutivo.

OBJECTIVE: To determine if there exist differences in the nutritional status of patients with dementia according to the type and severity of the disease. METHOD: In this cross-sectional study we carried out an assessment of the nutritional status (anthropometrical assessment, Mini Nutritional Assessment, Chang's protocol) in 83 institutionalized elderly diagnosed with dementia at evolutionary states of 5, 6, and 7 of GDS (Global Deterioration Scale) and FAST (Functional Assessment Stating). The results were analyzed by the Chi-squared, ANOVA, or Kruskal-Wallis tests, the Scheffé's posteriori contrasts, and the linear trend test. Significance was considered at p < 0.05. RESULTS: The mean age of the patients was 81.22 years. The BMI revealed that 21% of the sample were at risk for malnourishment and 14.5% were malnourished. However, by using the MNA, 56.6% of the patients were at risk for malnourishment and 41% were malnourished. According to the Chang's method, the percentage of malnourished patients was increased to 75.9%. None of these variables showed an association with the type of dementia. A significant association was observed between the evolutionary state of dementia and the BMI (p = 0.004), MNA (p = 0.002 and p = 0.006 for the score and the category, respectively), the muscle circumference of the arm (p = 0.043) and the calf circumference (p = 0.043) but not with the percentage of fat mass nor the nutritional diagnosis established by the Chang's method (degree and type of MN). The linear trend test confirmed that both the MNA and BMI scores and the muscle circumference of the arm and the calf circumference were lower in the more severe dementia states. CONCLUSION: Irrespective of the type of dementia, the presence of malnourishment in institutionalized elderly increases in parallel to the evolutionary degree of the dementia.

Presencia de malnutrición y riesgo de malnutrición en ancianos institucionalizados con demencia en función del tipo y estadío evolutivo / Presence of malnutrition and risk of malnutrition in institutionalized elderly with dementia according to the type and deterioration stage

Objetivo: Determinar si existen diferencias en el estado nutricional de los pacientes con demencia en función del tipo y la severidad de la misma. Método: Mediante un estudio transversal se realizó una valoración del estado nutricional (valoración antropométrica, Mini Nutricional Assessment, protocolo de Chang) en 83 ancianos institucionalizados con diagnóstico de demencia en estadíos evolutivos 5, 6 y 7 de las escalas GDS (Global Deterioration Scale) y FAST (Functional Assessment Stating). Los resultados se analizaron mediante los tests Chi-cuadrado, ANOVA o Kruskal-Wallis, contrastes a posteriori de Scheffé y test de tendencia lineal. La significación se alcanzó con p < 0,05. Resultados: La edad media de los residentes fue de 81,22 años. El IMC reveló que el 21% de la muestra presentaba riesgo de malnutrición y el 14,5% malnutrición por defecto. En cambio, el MNA clasificó al 56,6% de los residentes en situación de riesgo de malnutrición y al 41% con malnutrición. Según el método de Chang el porcentaje de pacientes malnutridos ascendió al 75,9%. Ninguna de estas variables mostró asociación con el tipo de demencia. Se observó una asociación significativa entre el estadío evolutivo de la demencia y el IMC (p = 0,004), MNA (p = 0,002 y p = 0,006 para la puntuación y la categoría, respectivamente), circunferencia muscular del brazo (p = 0,043) y circunferencia de la pantorrilla (p = 0,043); aunque no para el porcentaje de masa grasa ni para el diagnóstico nutricional establecido por el método de Chang (grado y tipo de MN). El test de tendencia lineal confirmó que tanto las puntuaciones del MNA y del IMC, como los valores de la circunferencia muscular del brazo y de la circunferencia de la pantorrilla fueron menores en los estadíos de demencia más severos. Conclusión: Independientemente del tipo de demencia, la presencia de malnutrición en ancianos institucionalizados aumenta conforme lo hace el estadío evolutivo de la misma (AU)

Objective: To determine if there exist differences in the nutritional status of patients with dementia according to the type and severity of the disease. Method: In this cross-sectional study we carried out an assessment of the nutritional status (anthropometrical assessment, Mini Nutritional Assessment, Chang's protocol) in 83 institutionalized elderly diagnosed with dementia at evolutionary states of 5, 6, and 7 of GDS (Global Deterioration Scale) and FAST (Functional Assessment Stating). The results were analyzed by the Chi-squared, ANOVA, or Kruskal-Wallis tests, the Scheffé's posteriori contrasts, and the linear trend test. Significance was considered at p < 0.05. Results: The mean age of the patients was 81.22 years. The BMI revealed that 21% of the sample were at risk for malnourishment and 14.5% were malnourished. However, by using the MNA, 56.6% of the patients were at risk for malnourishment and 41% were malnourished. According to the Chang's method, the percentage of malnourished patients was increased to 75.9%. None of these variables showed an association with the type of dementia. A significant association was observed between the evolutionary state of dementia and the BMI (p = 0.004), MNA (p = 0.002 and p = 0.006 for the score and the category, respectively), the muscle circumference of the arm (p = 0.043) and the calf circumference (p = 0.043) but not with the percentage of fat mass nor the nutritional diagnosis established by the Chang's method (degree and type of MN). The linear trend test confirmed that both the MNA and BMI scores and the muscle circumference of the arm and the calf circumference were lower in the more severe dementia states. Conclusion: Irrespective of the type of dementia, the presence of malnourishment in institutionalized elderly increases in parallel to the evolutionary degree of the dementia (AU)

Field evaluation of the single intradermal cervical tuberculin test and the interferon-gamma assay for detection and eradication of bovine tuberculosis in Spain.

A field comparison of the interferon-gamma (IFN-gamma) assay and the single intradermal cervical tuberculin (SICT) test for the diagnosis of bovine tuberculosis was conducted. A total of 1136 cattle belonging to 85 herds placed in 'Castilla y León' (northwestern Spain) were chosen, and 21 of these herds were subjected to the diagnostic assays two or three times at intervals of at least 4 months. All the animals positive to any of the tests were slaughtered and tuberculosis was confirmed by culture isolation method (CIM) and further identification by means of PCR. Only 10.6% of cattle reacted with the bovine PPD in the SICT test, a percentage that increased to 12.8% in the IFN-gamma assay. The sensitivity of the IFN-gamma assay compared to CIM was shown to be higher (84.9%) than that of the SICT test (80.2%), but the combination of both tests offered the highest sensitivity (92.9%). The number of false positive reactors (those animals in which CIM was negative) was considerably higher for the IFN-gamma assay than for the SICT test and, conversely, the number of false negative animals (M. bovis isolation but negative immunological result) was higher for the skin test than for the interferon assay. In the herds tested twice, tuberculosis was eradicated after the second cycle of testing in 50%, and in 75% after the third cycle in herds tested three times. The combination of these two techniques instead of separately seems, therefore, to be useful in eradication programmes against bovine tuberculosis.

Comparison of different methods for diagnosis of bovine tuberculosis from tuberculin- or interferon-gamma-reacting cattle in Spain.

Of 1479 cattle from herds in Northwestern Spain previously diagnosed as tuberculosis (TB) positive, 218 animals which gave a positive tuberculin or interferon-gamma reaction were examined at the slaughterhouse. Medial retropharyngeal and caudal mediastinal lymph nodes, and any tissues containing lesions suspected to be tuberculous, were removed and submitted to the laboratory. Three techniques for diagnosis of TB were used: post mortem examination (PME), smear staining by means of auramine O method (AOM), and culture isolation in Coletsos and Lowenstein-Jensen media followed by confirmation of M. tuberculosis complex organisms using PCR (CIM-PCR). Only 123 (29.9%) of the 412 samples collected showed typical tuberculous lesions. Confirmed M. tuberculosis complex organisms were isolated in 144 cases, 114 of which were from tissues showing lesions (success rate of 92.8%). Smears were found positive in 113 cases, 96 of which came from lesions suspected to be tuberculous (success rate of 78.0%). The sensitivities of CIM-PCR compared with those of PME and AOM were 92.7% and 85.7%, respectively. Statistical analysis revealed that PME and AOM are good indicators of the presence of M. tuberculosis complex organisms in tuberculin- or interferon-gamma reacting cattle.

Susceptibilities of Listeria species isolated from food to nine antimicrobial agents.

The agar dilution method was used to determine the activities of gentamicin, erythromycin, streptomycin, chloramphenicol, ampicillin, sulfamethazine, cephalothin, penicillin G, and tetracycline against 73 strains belonging to the genus Listeria (L. innocua, L. seeligeri, and L. monocytogenes). All strains were isolated from raw milk, cheese, the dairy processing plant, poultry, and the poultry slaughterhouse. Gentamicin, ampicillin, and erythromycin, of which the MICs for 90% of the strains tested for all three species were < or = 5.96 micrograms/ml, were found to be the most active agents studied. Most of the L. innocua strains isolated from poultry and the poultry slaughterhouse were resistant to tetracycline.

Revision of the O antigenic scheme of Listeria.

Factor sera against Listeria O antigens (serologic reference strains) were produced. The results confirm the validity of the O antigenic scheme established for Listeria, but show slight discrepancies in strains of serovars 4b, 4ab and 6b.

O antigenic structure of Listeria grayi and Listeria murrayi.

Cross-agglutination and absorption studies indicated that two serological reference strains of Listeria grayi and Listeria murrayi differed in at least one O factor. The serological analysis revealed that the unshared O factors are not present in other Listeria serovars. These results are not in accordance with the antigenic structure previously reported for L. grayi and L. murrayi, then a new O antigen formulation is proposed for these species: L. grayi (III), XII, XIV and XVI; L. murrayi (III), XII, XIV and XVII.

Serological studies on Listeria grayi and Listeria murrayi.

A cross-agglutination study between somatic antigens from reference strains of Listeria grayi and Listeria murrayi with rabbit antisera was done. L. murrayi antisera reacted, at low titres, with L. grayi but L. grayi antisera did not react with L. murrayi antigen. These results, together with agglutinin-absorption tests, led to the conclusion that the serologic relationship between L. grayi and L. murrayi is not as close as is thought. The two species seem to differ in at least one somatic factor, that might be designated O-XVI for L. grayi and O-XVII for L. murrayi. The serologic relationship of L. grayi and L. murrayi with other serovars of Listeria is discussed. The agglutination titre of 180 healthy ruminants against O-antigens of L. grayi and L. murrayi was also investigated; almost all the sera reacted with the antigens of these species, with similar titres (that reached 640) to those detected against O-antigens of serogroups 1/2 and 4.

Survival of Listeria monocytogenes in raw milk treated in a pilot plant size pasteurizer.

The survival of Listeria monocytogenes in raw milk treated in a pilot plant size pasteurizer was investigated. Raw milk was inoculated with different initial concentrations of L. monocytogenes and heated at temperatures ranging from 69 degrees to 73 degrees C. Listerias were not isolated from any of the milk samples immediately after thermal treatment. They were isolated, however, from 46.6% of heated samples (none from samples heated at 73 degrees C) after variable periods at refrigeration temperature. The results suggest that a low number of listerias survive some thermal treatments, but a cold enrichment is necessary to repair the thermally injured cells and detect these organisms in milk. The importance of the isolation technique in the recovery of listerias from pasteurized milk samples is discussed.

Microplate technique to determine hemolytic activity for routine typing of Listeria strains.

Because the hemolysis produced by Listeria monocytogenes and Listeria seeligeri on blood agar is frequently difficult to interpret, we developed a microplate technique for the routine determination of hemolytic activity with erythrocyte suspensions. This microtechnique is a simple and reliable test for distinguishing clearly between hemolytic and nonhemolytic strains and could be used instead of the CAMP (Christie-Atkins-Munch-Petersen) test with Staphylococcus aureus in the routine typing of Listeria strains. Furthermore, our results suggest that the quantitation of the hemolytic activity of the Listeria strains, along with the D-xylose, L-rhamnose, and alpha-methyl-D-mannoside acidification tests, allows the differentiation of L. monocytogenes, L. seeligeri, and Listeria ivanovii. We also observed that the treatment of erythrocytes with crude exosubstances of rhodococcus equi, Pseudomonas fluorescens, Acinetobacter calcoaceticus, and S. aureus enhanced the hemolytic activity of all Listeria strains with this characteristic.

[Listeria monocytogenes in pasteurized milk]. / Listeria monocytogenes dans le lait pasteurisé.

An haemolytic Listeria monocytogenes strain pathogenic to mice was isolated from 6 out of 28 (21.4%) pasteurized milk samples (3.2% fat milk treated at 78 degrees C for 15 s) marketed by a Madrid processing plant. Listeria grayi was recovered from 25 of the samples (89.2%) and L. innocua from 3 samples (10.7%). One milk sample was contaminated with L. welshimeri. No strains of L. ivanovii, L. seeligeri, L. murrayi, or L. denitrificans were isolated. These results show that pathogenic Listeria strains can be isolated from pasteurized milk and reinforce the hypothesis that this food product may be the source of numerous human listeriosis.

[Isolation of micro-organisms of the species Listeria from raw milk intended for human consumption]. / Isolation de micro-organismes du genre Listeria à partir de lait cru destiné à la consommation humaine.

Refrigerated mixtures of raw milk provided by a dairy which was supplied by farms from west and central Spain were tested for the presence of Listeria microorganisms. A total of 95 samples were taken at regular intervals over a 16-month period. Listeria grayi was isolated from 89.5% of the samples, Listeria monocytogenes s. str. from 45.3%, Listeria innocua from 15.8%, Listeria welshimeri from 3.1%, and Listeria seeligeri from 1.05%. Listeria ivanovii, Listeria murrayi, and Listeria denitrificans were not isolated.

New methodology for the isolation of Listeria microorganisms from heavily contaminated environments.

A new methodology was devised for the isolation of microorganisms of Listeria genus from heavily contaminated materials, by which 88% of tested sheep were identified as carriers. There were 286 strains isolated by our methodology versus 19 by the classical system.