Vastus Lateralis Motor Unit Recruitment Thresholds Are Compressed towards Lower Forces in Older Men.

BACKGROUND: Aging results in adaptations which may affect the control of motor units. OBJECTIVE: We sought to determine if younger and older men recruit motor units at similar force levels. DESIGN: Cross-sectional, between-subjects design. SETTING: Controlled laboratory setting. PARTICIPANTS: Twelve younger (age = 25 ± 3 years) and twelve older (age = 75 ± 8 years) men. MEASUREMENTS: Participants performed isometric contractions of the dominant knee extensors at a force level corresponding to 50% maximal voluntary contraction (MVC). Bipolar surface electromyographic (EMG) signals were detected from the vastus lateralis. A surface EMG signal decomposition algorithm was used to quantify the recruitment threshold of each motor unit, which was defined as the force level corresponding to the first firing. Recruitment thresholds were expressed in both relative (% MVC) and absolute (N) terms. To further understand age-related differences in motor unit control, we examined the mean firing rate versus recruitment threshold relationship at steady force. RESULTS: MVC force was greater in younger men (p = 0.010, d = 1.15). Older men had lower median recruitment thresholds in both absolute (p = 0.005, d = 1.29) and relative (p = 0.001, d = 1.53) terms. The absolute recruitment threshold range was larger for younger men (p = 0.020; d = 1.02), though a smaller difference was noted in relative terms (p = 0.235, d = 0.50). These findings were complimented by a generally flatter slope (p = 0.070; d = 0.78) and lower y-intercept (p = 0.009; d = 1.17) of the mean firing rate versus recruitment threshold relationship in older men. CONCLUSION: Older men tend to recruit more motor units at lower force levels. We speculate that recruitment threshold compression may be a neural adaptation serving to compensate for lower motor unit firing rates and/or denervation and subsequent re-innervation in aged muscle.

[Recurrent abdominal pain] / Dor abdominal recorrente.

OBJECTIVE: To present current concepts about the diagnosis of recurrent abdominal pain and to review the basis of the therapeutic approach for this disease in children and adolescents. METHODS: References were obtained from the Medline, from recent review articles, and from personal files. Books and dissertations were also analyzed. Only the most important articles were included in this review. RESULTS: Recurrent abdominal pain is the main cause of recurrent pain in children between 4 and 16 years of age. It is defined as the occurrence of three or more abdominal pain attacks within 3 months or less. These attacks are severe enough to interrupt routine activities, making the child remain asymptomatic between the episodes of pain. The diagnosis is based on a detailed clinical history, on an improved physical examination, and on a few laboratory tests. It can be manifested with isolated paroxysms of umbilical pain, abdominal pain with dyspeptic symptoms, and abdominal pain with digestive tract dysfunction. The treatment must emphasize the cognitive-behavioral factors of the recurrent pain. CONCLUSIONS: The treatment of recurrent abdominal pain using the strategy presented here represents an equilibrium in which time is neither wasted nor insufficient during the investigative process required for treating children and their families with this problem.

[Transesophageal echocardiography in patients treated with ventilation at a polyvalent intensive care unit]. / Ecocardiografia transesofágica em doentes ventilados numa unidade de cuidados intensivos polivalente.

Transthoracic echocardiography (TTE) has a definite role in general ICUs where its indications are now generally accepted. Transesophageal echocardiography (TEE) has widened the diagnostic scope of ultrasonic and doppler technology, partly by resolving the physical limitations of TTE. In this article the authors comment on their series of TTEs and TEEs, pointing out advantages, the diagnostic and therapeutic implications, especially in artificially ventilated patients. They conclude by emphasising the need to establish TEE as a routine diagnostic tool in general ICUs.

Prevalence of anemia among school-children from Rio Acima (State of Minas Gerais, Brazil): use of the standardized prevalence method and evaluation of iron deficiency.

The prevalence of anemia and iron deficiency was investigated in 332 children aged 7 to 15 years, 156 (47%) boys and 176 (53%) girls enrolled in the schools of the municipality of Rio Acima, MG. Seventy-four children were white (22.3%), 218 were mulatto (65.7%), and 40 were black (12%). Mean hemoglobin level was 12.75 +/- 0.75 g/dl. Lower values were determined for black children (12.32 +/- 0.87g/dl) compared to white (12.76 +/- 0.99 g/dl) and mulatto (12.81 +/- 0.94 g/dl) children. The prevalence of anemia was 16.6% when determined on the basis of the percentage of children with hemoglobin values lower than the 3rd percentile for age and sex (standard method), and 36.2% when determined by the standardized prevalence method for the evaluation of the prevalence of malnutrition in populations. Depletion of iron reserves was 8.13% for the population in general and 20% for the anemic children. This low prevalence of iron deficiency may have been the result of the value adopted as the lower normal limit (10 ng/ml) for serum ferritin values. The small percentage of anemic children with iron depletion may also be justified by the standard of normality adopted for hemoglobin values which was originally elaborated for the white population of North America and Finland and therefore may be inadequate for the population studied here, of diverse racial composition.

Prevalence of anemia among school-children from Rio-Acima (State of Minas Gerais, Brazil): use of the standardized prevalence method and evaluation of iron deficiency

The prevalence of anemia and iron deficiency was investigated in 332 children aged 7 to 15 years, 156 (47 per cent) boys and 176 (53 per cent) girls enrolled in the schools of the municipality of Rio Acima, MG. Seventy-four children were white (22.3 per cent), 218 were mulatto (65.7 per cent), and 40 were black (12 per cent). Mean hemoglobin level was 12.75 ñ 0.75 g/ dl. Lower values were determined for black children (12.32 + 0.87 g/dl) compared to white (l2.76 ñ 0.99 g/dl) and mulatto (12.81 ñ 0.94 g/dl) children. The prevalence of anemia was 16.6 per cent when determined on the basis of the percentage of children with hemoglobin values lower than the 3rd percentile for age and sex (standard method), and 36.2 per cent when determined by the standardized prevalence method for the evaluation of the prevalence of malnutrition in populations. Depletion of iron reserves was 8.13 per cent for the population in general and 20 per cent for the anemic children. This low prevalence of iron deficiency may have been the result of the value adopted as the lower normal limit (10 ng/ml) for serum ferritin values. The small percentage of anemic children with iron depletion may also be justified by the standard of normality adopted for hemoglobin values which was originally elaborated for the white population of North America and Finland and therefore may be inadequate for the population studied here, of diverse racial composition.

[The role of echocardiography in intensive care]. / O papel da ecocardiografia em cuidados intensivos.

Echocardiography hasn't played yet a major role in the majority of the noncardiac intensive care units, specially the ones with general multi-care profile. In the past few years an increasing number of patients admitted have an important cardiac component, reason why we emphasize the role of this non invasive diagnostic tool. It's easily performed, may be repeated as many times as necessary, thus providing a quick diagnosis of the disease, its repercussions and medical or surgical interventions.

Is dilution of cows' milk formula necessary for dietary management of acute diarrhoea in infants aged less than 6 months?

There is concern that feeding full-strength animal milk to infants aged less than 6 months with diarrhoea may have adverse consequences. We assessed the effects on clinical course of two feeding regimens in 159 Guatemalan and Brazilian infants aged 2 weeks to 6 months who had had acute diarrhoea for 120 h or less, showed signs of mild to moderate dehydration, and had no complications. After correction of dehydration, infants were assigned randomly to receive continued full-strength milk feeding or initial feeding with diluted milk with regrading to full-strength milk over 48 h. There were no significant differences between feeding groups in rate of treatment failures (-1%, 95% Cl -14 to 12%) or mean (SD) total stool output (full-strength milk 335 [268] g/kg, diluted milk 338 [354] g/kg) and duration of diarrhoea (92 [50] vs 92 [44] h). A significant association was found between presence of reducing substances in stools and treatment failure (OR 4.3, 95% CI 1.1 to 16.8), but reducing substances in stools were common both in treatment successes (61%) and in failures (87%). Our study supports the conclusion that, for infants under 6 months of age with diarrhoea whose only food is animal milk or formula, the milk or formula normally given should be provided in full strength as soon as dehydration has been corrected.

[Von Recklinghausen's neurofibromatosis]. / Neurofibromatose de von Recklinghausen.

Neurofibromatosis is a multisystemic disease in which the multiple possible clinical manifestations may have important diagnostic and prognostic implications; if arterial hypertension coexists, many pathogenic mechanisms justify that the possible secondary etiology must be considered. In this report we review the pathogenic and clinical mechanisms and we point to the diagnostic strategy to reveal anomalies and diseases that, although present, may be occult.

[Von Recklinghausen neurofibromatosis and malignant pheochromocytoma: presentation of 3 cases]. / Neurofibromatose de von Recklinghausen e feocromocitoma maligno: apresentação de três casos.

Neurofibromatosis may involve every organ. Manifestations vary greatly and different kind of neoplasia may be associated with excessive frequency; it's the case of pheochromocytoma that, as a benign tumor, coexists in 10%. Description of coexistency as a malignant tumor is a rarity; therefore, we think it's interesting to publish our experience. Nevertheless the association of Von Recklinghausen's disease with hypertension is not always dependent of that kind of association.

Chronic calcifying pancreatitis in children: a report of six cases.

1. A study of six patients with Chronic Calcifying Pancreatitis (CCP) occurring over a 10 year period, representing an incidence rate of approximately 1:1,000 of the inpatients in the children's ward of a general hospital in central Brazil, is reported. 2. Major clinical manifestations as well as therapeutic management are described. 3. The possible relationship between CCP and primary protein-calorie malnutrition is discussed and the importance of a CCP diagnosis when dealing with malnourished children who do not respond satisfactorily to common therapy is emphasized.

Chronic calcifying pancreatitis in children: a report of six cases

1. Study of six patients with chronic calcifying pancreatitis (CCP) occurring over a 10 year period, representing an incidence rate of approximately 1:1,000 of the impatients in the children's ward of a general hospital in central Brazil, is reported. 2. Major clinical manifestations as well as therapeutic management are described. 3. The possible relationship between CCP and primary protein-calorie malnutrition is discussed and the importance of a CCP diagnosis when dealing malnourished children who do not respond satisfactorily to common therapy is emphasized

Doenca celiaca:aspectos atuais e nossa experiencia. / Celic disease: current aspects and our experience

Neste trabalho sao feitas consideracoes sobre a doenca celiaca. Uma casuistica e apresentada, e a necessidade de se estabelecer criterios bem definidos da doenca e discutida. Enfatiza-se o risco de complicacoes que correm os celiacos em uso de gluten. Manifestacoes clinicas pouco comuns e outras menos evidentes sao abordadas no trabalho o efeito protetor do leite humano e enfatizado

Uso da dieta de frango no tratamento da diarreia protraida do lactante. / Use of chicken diet in the treatment of protracted infantile diarrhea

Os autores apresentam a sua experiencia com o uso de carne de peito de frango como fonte proteica no tratamento dietetico da diarreia protraida do lactente. Os bons resultados obtidos sao motivo de sugestao para o uso desta formula

Coeliac disease in identical twins.

Coeliac disease occurred at the same age in MZ twins. The diagnosis was confirmed by histology of the small intestine, rapid response to a gluten-free diet, and relapse after reintroduction of gluten.