Altered Kinetics Properties of Erythrocyte Lactate Dehydrogenase in Type II Diabetic Patients and Its Implications for Lactic Acidosis

Recent studies have been noted that the erythrocytes from Type II diabetic patients show significantly altered structural and functional characteristics along with the changed intracellular concentrations of glycolytic intermediates. More recent studies from our laboratory have shown that the activities of enzymes of glycolytic pathway changed significantly in RBCs from Type II diabetic patients. In particular the levels of lactate dehydrogenase (LDH) increased significantly. Lactic acidosis is an established feature of diabetes and LDH plays a crucial role in conversion of pyruvate to lactate and reportedly, the levels of lactate are significantly high which is consistent with our observation on increased levels of LDH. Owing to this background, we examined the role of erythrocyte LDH in lactic acidosis by studying its kinetics properties in Type II diabetic patients. Km, Vmax and apparent catalytic efficiency were determined using pyruvate and NADH as the substrates. With pyruvate as the substrate the Km values were comparable but Vmax increased significantly in the diabetic group. With NADH as the substrate the enzyme activity of the diabetic group resolved in two components as against a single component in the controls. The Apparent Kcat and Kcat/Km values for pyruvate increased in the diabetic group. The Ki for pyruvate increased by two fold for the enzyme from diabetic group with a marginal decrease in Ki for NADH. The observed changes in catalytic attributes are conducive to enable the enzyme to carry the reaction in forward direction towards conversion of pyruvate to lactate leading to lactic acidosis.     

Chronic flexibility gains: effect of isometric contraction duration during proprioceptive neuromuscular facilitation stretching techniques

The aim of this study was to assess the effect of to isometic contraction durations during propiceptive neuromuscular facilitation stretching on gains inflexion at the hip. Forty-three women (M age = 20.0 years, SD = 1.3) were assigned to one of three groups: 5-s isometric contraction (5-IC), 10-IC, and control. Flexibility was assessed at baseline and Weeks 3 and 6. Analysis of covariance, controlling for pretest differences, showed a significant interaction, F(2, 33) = 44.1, p < .001. Flexibility was significant lower in the control group relative to the 5-IC and 10-IC groups and in the 5-IC group relative to the 10-IC group at 3 and 6 weeks (3 weeks = 101.2 +/- 1.4 degrees, 114.3 +/- 1.5 degrees, 120.5 +/- 1.3 degrees; 6 weeks = 103.0 +/- 1.4 degrees, 126.1 +/- 1.6 degrees, 133.3 +/- 1.4 degrees for control, 5-IC and 10-IC groups, respectively). A longer contraction time led to greater increases in flexibility.     

Effects of muscle-tendon length on joint moment and power during sprint starts

The aim of this study was to examine the effects of muscle-tendon length on joint moment and power during maximal sprint starts. Nine male sprinters performed maximal sprint starts from the blocks that were adjusted either to 40 degrees or 65 degrees to the horizontal. Ground reaction forces were recorded at 833 Hz using a force platform and kinematic data were recorded at 200 Hz with a film camera. Joint moments and powers were analysed using kinematic and kinetic data. Muscle - tendon lengths of the medial gastrocnemius, soleus, vastus medialis, rectus femoris and biceps femoris were calculated from the set position to the end of the first single leg contact. The results indicated that block velocity (the horizontal velocity of centre of mass at the end of the block phase) was greater (P < 0.01) in the 40 degrees than in the 65 degrees block angle condition (3.39 +/- 0.23 vs. 3.30 +/- 0.21 m . s(-1)). Similarly, the initial lengths of the gastrocnemius and soleus of the front leg in the block at the beginning of force production until half way through the block phase were longer (P < 0.001) in the 40 degrees than in the 65 degrees block angle condition. The initial length and the length in the middle of the block phase were also longer in the 40 degrees than in the 65 degrees block angle condition both for both the gastrocnemius (P < 0.01) and soleus (P < 0.01-0.05) of the rear leg. In contrast, the initial lengths of the rectus femoris and vastus medialis of the front leg were longer (P < 0.05) in the 65 degrees than in the 40 degrees block angle condition. All differences gradually disappeared during the later block phase. The peak ankle joint moment (P < 0.01) and power (P < 0.05) during the block phase were greater in the 40 degrees than in the 65 degrees block angle condition for the rear leg. The peak ankle joint moment during the block phase was greater (P < 0.05) in the 40 degrees block angle for the front leg, whereas the peak knee joint moment of the rear leg was greater (P < 0.01) in the 65 degrees block angle condition. The results suggest that the longer initial muscle-tendon lengths of the gastrocnemius and soleus in the block phase at the beginning of force production contribute to the greater peak ankle joint moment and power and consequently the greater block velocity during the sprint start.     

Comparison of heart rate monitoring with indirect calorimetry for energy expenditure evaluation

PurposeThe purpose of this study was to compare established methods with newly-developed methods for estimating the total energy expenditure (TEE).MethodsThe study subjects comprised 46 individuals, including 16 middle-aged men (mean age 51.4 years), 14 middle-aged women (mean age 49.9 years) and 16 young women (mean age 19.1 years). The TEE was estimated from 24-h heart rate (HR) data using newly-developed software (MoveSense HRAnalyzer 2011a, RC1, Suunto Oy, Vantaa, Finland), and was compared against the TEE determined using doubly labeled water (DLW). Agreement between the two methods was analyzed using Bland and Altman plots.ResultsThe HR method yielded similar TEE values as the DLW method at the group level, with an average of 8.6 kcal/day in the difference in the mean, but with large individual variations. Forty-four (96%) out of 46 subjects fell within ±2SD of the mean difference in TEE comparisons, and there was no tendency towards under- or over-estimation.ConclusionOur results indicate that the current software using HR analysis for the estimation of daily TEE needs further development for use with free-living individuals.     

Cumulative stress and substantiated maltreatment: the importance of caregiver vulnerability and adult partner violence

OBJECTIVE: Our goal is to assess the effect of caregiver vulnerabilities, singly and in combination, on the substantiation of child abuse (physical, sexual) and neglect, while controlling for relevant background variables. We test the moderator role of adult partner violence in qualifying the relationship between caregiver vulnerabilities and maltreatment substantiation. METHOD: Secondary analyses of the 1998 Canadian Incidence Study of Reported Child Maltreatment (CIS) are used to predict child protective service investigation substantiation versus non-substantiation from a range of caregiver vulnerability factors. Involvement in partner violence was examined as a moderator in the relation between caregiver vulnerabilities and maltreatment substantiation. The CIS is an epidemiological survey of first-reported cases to child protective services, using a random sample of child welfare agencies across Canada. Child welfare workers completed a research form on the child, primary caregiver, family, perpetrator, severity and type of maltreatment, as well as services and court outcomes. All maltreatment classifications were assigned according to the Canadian legal definition of child abuse and neglect. Hierarchical logistic regression analyses were used, with stepped entry of: (1) demographic factors, socioeconomic disadvantage, and caregiver's own history of maltreatment; (2) caregiver vulnerability factors; (3) involvement in partner violence; (4) the interaction between caregiver vulnerability and partner violence. RESULTS: Caregiver substance abuse was found to be the single most potent kind of caregiver vulnerability in predicting maltreatment substantiation. When the total number of vulnerabilities was used as the predictor, prediction across all types of maltreatment increased, especially for substantiated neglect. Analyses also showed that the presence of partner violence in the home exacerbated the effect of caregiver vulnerability on substantiation. CONCLUSIONS: The total number of caregiver vulnerabilities was the best predictor of the substantiation of child abuse and neglect. This relationship was moderated by the existence of partner violence: high caregiver vulnerability and high partner violence increased the likelihood of substantiation versus non-substantiation. These results suggest that caregiver issues should be considered in tandem with partner relationships. Among child welfare cases, caregiver vulnerability and partner violence are critical targets for child maltreatment prevention and early child protective services intervention.     

Using educational placement in third grade to select and validate a preschool screening measure

The early detection of children with mild learning problems remains a problem. New screening tests are being developed that will be more effective in identifying children who fall into this “difficult to identify” group. This study examined the predictive validity of one potential screening test. The scores of 268 children on each task of a nine‐task preschool cognitive battery were evaluated in terms of the accuracy with which they predicted the classification of those same children into regular education (n = 254) or special education (n = 14) 4 years later when the children were in third grade. A classification accuracy level of 79% was achieved for the exceptional children, and a classification level of 70% for the normally achieving children. Racial/ethnic status, testing language, and socioeconomic status all impacted the children's screening performance. Lower screening scores and a greater proportion of the sample with scores below the cut were associated with minority status, not being tested in English, and lower socioeconomic status. Preschool testing in Spanish or both English and Spanish was associated with poorer achievement 4 years later. Many of the children not in special education, but with a screening score below 13, had serious academic problems in third grade that were reflected in their low percentile scores on one or more subtests of the Stanford Achievement Test. © 2003 Wiley Periodicals, Inc. Psychol Schs 40: 565–582, 2003.     

The urban and the natural in education reform: the development of Hamburg Schullandheime (rural school hostels) in the 1920s

ABSTRACT

The desire to be close to nature and live in tune with it grew as industrialisation, urbanisation and the impact of technology became increasingly ubiquitous at the turn of the twentieth century. Throughout Europe, model schools were established in rural environments. These private reform schools could not solve the problems of public urban schools. Founded on the initiative of teachers and parents, the Schullandheim (rural school hostel) emerged as a new form bringing urban education and schooling close to nature after the First World War in Germany. Even if related pedagogic activities developed at that time in other countries there is no evidence for comparable institutions. Besides tracing the development of Schullandheime, the article shows how the school hostel idea was embedded in the contemporary educational discussion about the influence large cities had on youth and explores the educational and cultural differences within the school hostel movement through the use of visual material.     

Making Connections: Linking Cognitive Psychology and Intervention Research to Improve Comprehension of Struggling Readers

Many studies have demonstrated the efficacy of reading comprehension interventions for struggling readers, including students with learning disabilities. Yet, some readers continue to struggle with comprehension despite receiving these interventions. In this article, we argue that an explicit link between cognitive psychology and intervention research contributes to knowledge regarding for whom and under what conditions reading comprehension interventions are most likely to be beneficial. First, we provide a brief overview of a cognitive perspective on reading comprehension. Next, we illustrate an application of this perspective by describing a collaborative project in which we examined interactions among reader characteristics, text properties, and instructional contexts. Last, we highlight directions for future research and implications for practice.