Exercise intensity, training, diet, and lactate concentration in muscle and blood

With some, but not all, types and intensities of exercise, lactate accumulates in the blood and in the muscles engaged in the exercise. A great deal of attention has been directed towards attempting to understand the dynamics of lactate production and removal at the onset of exercise, during exercise, and during the recovery process following exercise. It has been hoped that an unravelling of these events would provide a key to understanding cellular metabolism and its regulation during exercise. The purpose of this introductory paper to a symposium on lactate is to present a brief overview of some of the conditions that influence the rate and magnitude of lactate accumulation during exercise. It is pointed out that many conditions influence the rate and magnitude of the accumulation of lactate in blood and muscles. Included are diet, state of physical fitness, and the type and duration of the exercise. We have cautioned against trying to evaluate the state of oxygen delivery to muscle and the state of tissue oxygenation from the appearance of lactate in blood. We have pointed out the positive aspects of lactate production based on how it augments the cellular supply of ATP, thereby allowing for high intensity exercise, and also the negative aspects that develop as a result the reduction in pH which adversely influences many cellular processes essential for muscular activity.     

Antigen presentation by a B-cell line transfected with cloned immunoglobulin heavy- and light-chain genes specific for a defined hapten.

The rearranged genes encoding immunoglobulin heavy (mu) and light (kappa) chains specific for the hapten 2,4,6-trinitrophenyl (Tnp) were introduced into a B-lymphoma line that bears surface IgG with an unknown specificity and expresses surface Ia molecules. A transformant expressing surface IgM specific for Tnp was obtained. The transformant was found to present Tnp-proteins to antigen (protein)-specific T cells far more efficiently than the parenteral B-lymphoma line. This artificial system, utilizing recombinant DNA technology and gene transfer, provides several approaches for the study of T-cell-B-cell interactions.     

哮喘患儿血清嗜酸性粒细胞阳离子蛋白改变及其意义

目的：评价变应性哮喘患儿血清嗜酸性粒细胞阳离子蛋白（S-ECP）水平改变及其意义。方法：测定25例哮喘发作期患儿糖皮质激素吸入治疗12周前后，及20例未予糖皮质激素吸入治疗的哮喘缓解期患儿S-ECP水平，并对发作期患儿S-ECP水平变化与血嗜酸性粒细胞计数（B-EOS）、肺功能一秒用力呼气量（FEV1）、一秒用力呼气量比用力肺活量（FEV1/FVC）及症状评分的关系作相关性分析。结果：哮喘发作组治疗后S-ECP水平较治疗前显著降低，与对照组（健康儿童10名）比较差异无显著性；哮喘缓解组S-ECP水平明显高于发作组治疗后，但明显低于发作组治疗前。哮喘发作组治疗前S-ECP水平变化与B-EOS无相关性，与FEV1、FEV1/FVC呈负相关，与症状评分呈正相关。结论：监测S-ECP水平可作为评价哮喘气道炎症程度、病情预后和指导抗炎治疗的有效指标。     

Postoperative convalescence after inguinal hernia surgery: Prospective randomized multicenter study of laparoscopic versus Shouldice inguinal hernia repair in 1042 patients

Interest in inguinal hernia surgery has increased significantly with the introduction of new operating techniques during the past decade. This multicenter study compared short-term results in patients treated by the laparoscopic transabdominal preperitoneal patch technique (TAPP; n=518) and the Shouldice technique (n=524). We evaluated demographics, operative data, complications, hospital stay, postoperative pain, use of analgesics, functional status, sick leave, and complaints up to 3 months postoperatively. The median operating time was shorter in the Shouldice group (55 vs. 65 min), but there were no significant differences in complication rates, and major complications were rare. The hospital stay was 1 day or less in over 98% of cases in both groups, but more operations were performed on outpatient basis in the Shouldice group. In the TAPP group postoperative pain and analgesic consumption were less, postoperative functional status was better, and sick leave was shorter (10 vs. 14 days). These results show that the two methods are equally safe and have few major complications. The TAPP operation is associated with less postoperative pain, better postoperative functional status, and shorter sick leave, but at the price of a longer operating time. Electronic Publication