Silicon-mediated and constitutive resistance to Rhopalosiphum maidis (Hemiptera: Aphididae) in corn hybrids.

The corn leaf aphid, Rhopalosiphum maidis (Fitch) (Hemiptera: Aphididae), is an important pest of corn, but no corn genotypes resistant to R. maidis are commercially available. Although the ability of silicon to induce plant resistance against some insects is known, the effect of silicon on R. maidis and in corn hybrids with different levels of constitutive resistance is still unknown. This study sought to determine the constitutive resistance of corn hybrids to R. maidis and silicon resistance induction in hybrids with different degrees of constitutive resistance. Field experiments with natural infestations of aphids were conducted in three locations in Brazil (Patos de Minas, Araguari, and Tupaciguara). Greenhouse trials were also used to evaluate the effect of varietal resistance on aphid population growth and identify resistant and susceptible genotypes. Aphid resistance induced by silicon was determined with resistant and susceptible corn hybrids. In the field, the corn hybrids BM8850, AS1625PRO, and DKB310PRO had the greatest proportion of plants infested by R. maidis in all three localities. The hybrids P30F53H, STATUS VIP, BM9288, DAS2B587HX, DKB175PRO, AS1633PRO, and DKB390PRO2 were the least infested in Patos de Minas and Araguari, and P30F53H was the least infested in Tupaciguara. When antibiosis effects were evaluated by aphid population growth, the hybrids AG7088PRO3 and DKB310PRO2 were susceptible, while P30F53YH was resistant. When natural aphid infestation was evaluated, wherein the effects of antibiosis and non-preference could not be discriminated, soil applications of silicon-induced resistance to R. maidis in both susceptible and constitutively resistant corn hybrids.

[Ewing's tests validation for autonomic dysfunction assessment]. / Validação dos testes de Ewing para avaliação de disfunção autonômica.

The medical literature on the evaluation of autonomic dysfunction accumulated discordant results in the past decades, accentuating the need of validating the proposed tests. The Ewing's tests for studying autonomic abnormalities received increasing acceptance, as they recognize not only cardiovascular reflexes damage but lesions in any other segments of the autonomic nervous system. We proposed to validate them in our population by analysing their results on 30 normal individuals and 23 long-standing diabetics. Our results show that the five tests are highly sensitive and specific, reproducible, use simple and available office material, and fulfil their purpose.

[Myopathy due to carnitine palmitoyltransferase deficiency. Report of 2 cases with enzymatic analyses on muscle tissue]. / Miopatia por deficiência de carnitina-palmitil-transferase. Relato de 2 casos com dosagens enzimáticas no tecido muscular.

We describe two brothers, 25 and 19 years-old, with muscle pain and decreased strength after prolonged exercise; these symptoms are worsened by cold whether of fasting. One of the patients developed recurrent myoglobinuria and had one episode of renal failure. Laboratory investigations were normal between the crises, but during myoglobinuria, serum creatine kinase activity increased 100 times. Electromyography was suggestive of denervation. Muscle biopsy showed increased lipid droplets by the "oil red O" stain and increased activity of succinic dehydrogenase histochemical reaction. Lactate production during ischemia was normal. Biochemical analysis showed decreased carnitine-palmityl-transferase activity in muscle (7.23 and 10.58 nmoles/min/gr; normal range 66.7 +/- 17.3), with normal values for carnitine-octanoyl-transferase and carnitine-acetyl-transferase. The metabolic pathway of fatty acid utilization as an energy source for muscle during exercise in normal and in pathological conditions is discussed.

Miopatia por deficiencia de carnitina-palmitil-transferase: relato de 2 casos com dosagens enzimaticas no tecido muscular. / Myopathy due to carnitine plamitoyltransferase deficiency: report of 2 cases with enzymatic doses in the muscular tissue

Relato dos casos de dois irmaos, que desde a infancia apresentavam dores musculares apos exercicio prolongado ou exposicao ao frio, com diminuicao da forca a medida que o exercicio continuava. Um deles desenvolveu mioglobinuria recorrente e, em um episodio apresentou insuficiencia renal aguda necessitando de dialise peritonial. A investigacao laboratorial intercrise foi normal, mas durante o episodio de mioglobinuria,apresentou grande aumento da creatinafosfoquinase. A eletromiografia foi sugestiva de processo de denervacao. Teste de producao de lactato durante isquemia foi normal. Biopsias musculares mostraram discreto aumento dos lipidios nas fibras musculares e maior atividade da desidrogenase succinica na histoquimica. O estudo bioquimico do tecido muscular dos dois pacientes, revelou importante reducao da atividade da carnitina-palmitil-transferase Sao discutidas vias metabolicas, sua importancia na manutencao da energia muscular durante o exercicio prolongado e o papel dos acidos graxos como fonte energetica muscular durante condicoes normais e patologicas

[Tubular aggregates in a case of chronic proximal spinal atrophy]. / Agregados tubulares em caso de atrofia espinhal crônica proximal.

The case of a 35 years-old man, with chronic proximal muscle atrophy in which at the muscle biopsy tubular aggregates were found by histochemistry procedures is reported. The tubular aggregates stained positive with the modified Gomori trichrome, haematoxylin-eosin, DPNH-diaphorase, non specific esterases, phosphorylase, P.A.S., oil red O and lactate dehydrogenase. They did not show in the routine and acid pre-incubated ATPase, acid and alkaline phosphatases and succinate dehydrogenase. Only found in type II fibers. A brief discussion about the pathogenesis and function of the tubular aggregates is made. The authors believe that the tubular aggregates in this case are secondary to prolonged use of phenobarbital and diphenylhydantoin, associated with the basic denervation process and alcohol abuse.