bluuebunny/crossref_metadata_2025_split huggingface dataset:
Microphotometric analysis of NADH‐tetrazolium reductase deficiency in fibroblasts of patients with Leber hereditary optic neuropathy
Authors: Malik S. , Sudoyo H. , Marzuki S. 
Published: December 2002

AbstractWe employed a microphotometric approach to examine whether a defect in the mitochondrial respiratory complex I expected in Leber hereditary optic neuropathy (LHON) as the consequence of a mtDNA (11778G>A) mutation in the ND4 gene coding for a subunit of the respiratory complex I can be detected at the single‐cell level. Genetically stable fibroblast cell lines were established from skin biopsies of two members of a Chinese Indonesian family with LHON. The fibroblasts were homoplasmic for the 11778G>A mutation. The activity of the respiratory complex I was examined histochemically by staining for NADH‐tetrazolium reductase. The histochemical staining showed a typical pattern with an apparent concentration of the activity around the nucleus, suggested as the reflection of the gradient in the thickness of the unsectioned fibroblast cells. Microphotometric quantification of the staining intensity showed that the activity is linear for at least 60min. The activity shows a discontinuity in its Arrhenius kinetics with a break point at 13.0–13.5°C (activation energy at 50–58 J/mol and 209–238 J/mol above and below the break temperature, respectively), indicating the membrane association of the NADH‐tetrazolium reductase activity. Both patients showed lower fibroblast NADH‐tetrazolium reductase activity, with a reduction of ∼30%. Our results demonstrate the utility of microphotometric analysis in the study of biochemical defects associated with mutations in the mtDNA.
Normative Influences on Aggression in Urban Elementary School Classrooms
Authors: Henry David , Guerra Nancy , Huesmann Rowell , Tolan Patrick , VanAcker Richard , Eron Leonard 
Published: December 2002

AbstractWe report a study aimed at understanding the effects of classroom normative influences on individual aggressive behavior, using samples of 614 and 427 urban elementary school children. Participants were assessed with measures of aggressive behavior and normative beliefs about aggression. We tested hypotheses related to the effects of personal normative beliefs, descriptive classroom norms (the central tendency of classmates' aggressive behavior), injunctive classroom normative beliefs (classmates' beliefs about the acceptability of aggression), and norm salience (student and teacher sanctions against aggression) on longitudinal changes in aggressive behavior and beliefs. Injunctive norms affected individual normative beliefs and aggression, but descriptive norms had no effect on either. In classrooms where students and teachers made norms against aggression salient, aggressive behavior diminished over time. Implications for classroom behavior management and further research are discussed.
The Latent Structure of Substance Use Among American Indian Adolescents: An Example Using Categorical Variables
Authors: Mitchell Christina M. , Plunkett Mark 
Published: December 2002

AbstractResearchers frequently have only categorical data to analyze and cannot, for theoretical or methodological reasons, assume that the observed variables are discrete representations of an underlying continuous variable. We present latent class analysis as an alternative method of measuring latent variables in these circumstances. Latent class analysis does not require the assumptions of factor analyses about the nature of manifest and latent variables, but does allow the use of more precise model selection than techniques such as cluster analysis. We modeled the lifetime substance use of American Indian youth. The latent class model of American Indian teenagers' substance use had four classes: Abstaining, Predominantly Alcohol, Predominantly Alcohol and Marijuana, and Plural Substance. We then demonstrated the usefulness of this latent variable by using it to differentiate levels of several variables in a manner consistent with Social Cognitive Theory.
Subverting Culture: Promoting HIV/AIDS Prevention Among Puerto Rican and Dominican Women
Authors: Ortiz-Torres Blanca , Serrano-García Irma , Torres-Burgos Nélida 
Published: December 2002

AbstractThis article discusses the challenges faced by researchers and interventionists when attempting to promote change in social norms and normative beliefs that promote HIV/AIDS risk‐related behaviors among Puerto Rican and Dominican women. The article focuses on the role of culture in HIV/AIDS prevention with women by analyzing the sociohistorical context of some cultural beliefs and by illustrating the tension between risk‐related and protective cultural beliefs in research conducted by the authors with women in both New York and Puerto Rico. The authors propose that promoting changes in sex‐related social norms and normative beliefs might be constructed as a subversive act and present the challenge this analysis poses for community psychology. They conclude that this conceptualization might be construed as subversive because rather than idealizing culture, it promotes changes that respect diversity within the culture and foster participation in the development of new cultural values, beliefs and norms.
A Cost Analysis of Self‐Management Programs for People with Chronic Illness
Authors: Groessl Erik J. , Cronan Terry A. 
Published: December 2002

AbstractThe soaring cost of health care is a national problem that needs response at multiple levels, including that of the community. Reducing or limiting health care costs through interventions that emphasize the self‐management of health may promote broader health care coverage, better quality of health care, and a sense of control over one's health. Therefore, it behooves community psychologists to perform cost analyses when testing interventions for people in a community. The present study investigated the effects of social support and education interventions on psychosocial variables, health status, and health care costs in older people with osteoarthritis. Participants were 363 members of a health maintenance organization (HMO), 60 years of age and older, with osteoarthritis. Participants were randomly assigned to one of three intervention groups (social support, education, or a combination of both) or to a control group. The results indicated that feelings of helplessness decreased in the intervention groups but not in the control group. All groups showed increases in self‐efficacy and overall health status. In addition, health care costs increased less in the intervention groups than in the control group. Cost analysis was used to demonstrate that the monetary savings of the intervention greatly outweighed the cost of conducting the intervention. It appears that interventions can limit health care costs while improving health and increasing feelings of control for older people with osteoarthritis. Further, this paper demonstrates how a cost‐benefit focus can benefit community studies.
Help‐Seeking Comfort and Receiving Social Support: The Role of Ethnicity and Context of Need
Authors: Kaniasty Krzysztof , Norris Fran H. 
Published: December 2002

AbstractExamined help‐seeking comfort and receiving social support among Latinos, African Americans, and European Americans across two contexts: in a communitywide emergency (Hurricane Andrew) and 2 years later in a nonemergency situation. In general, help‐seeking comfort was a strong predictor of received support. Notwithstanding many similarities between the groups, the effects of ethnicity differed according to the context. In emergency, all groups reported similarly high levels of help‐seeking comfort and received support. In nonemergency, help‐seeking comfort declined for blacks and whites but not for Latinos. Although all ethnic groups reported receiving less social support in nonemergency, the decline in received support across contexts was most dramatic for Latinos. Situational, cultural, and differential resource loss explanations are offered to account for the findings.
The Coming‐Out Process and Its Adaptational and Health‐Related Associations Among Gay, Lesbian, and Bisexual Youths: Stipulation and Exploration of a Model
Authors: Rosario Margaret , Hunter Joyce , Maguen Shira , Gwadz Marya , Smith Raymond 
Published: December 2002

AbstractA model is proposed and explored that links the coming‐out process to the psychological functioning (i.e., self‐esteem and distress) and sexual behaviors of gay, lesbian, and bisexual youths recruited from gay‐focused community‐based and college organizations in New York City. The coming‐out process is multidimensional, consisting, as defined here, of involvement in gay/lesbian activities, attitudes toward homosexuality, comfort with homosexuality, self‐disclosure of sexual identity to others, and sexual identity. The coming‐out dimensions were related to self‐esteem, distress, and unprotected sexual behaviors. In addition, the relations between the coming‐out dimensions and unprotected sexual behaviors were explained by psychological functioning. In particular, limited involvement in gay/lesbian activities was associated with more unprotected sex. Negative attitudes toward homosexuality were related directly to more unprotected sex, and they were related indirectly to more unprotected sex by means of increasing emotional distress. These and other findings have implications for designing preventive interventions to increase the youths' psychological functioning and reduce their unprotected sexual behaviors.
The Benefits of Mutual Support Groups for Parents of Children With Disabilities
Authors: Solomon Michael , Pistrang Nancy , Barker Chris 
Published: December 2002

AbstractThis study examined what parents of children with disabilities and special needs found helpful about belonging to mutual support groups. Quantitative data (based on 56 parents from 6 groups) indicated that members found the groups very helpful and were very satisfied with the support they received from their groups; they also described the groups as high in cohesion, expressiveness, task orientation, and self‐discovery. A grounded theory analysis of focus group data (based on 43 parents from 5 of the groups) indicated that such support was helpful in three broad domains: (1) the sociopolitical, which involved developing a sense of control and agency in the outside world; (2) the interpersonal, which involved asense of belonging to a community; and (3) the intraindividual, which involved self change. A central theme of identity change emerged as superordinate to these three categories.
Identification of ‘private’ mutations in patients with ornithine transcarbamylase deficiency
Authors: Tuchman M. , Morizono H. , Rajagopal B. S. , Plante R. J. , Allewell N. M. 
Published: December 2002

AbstractThe majority of cases of ornithine transcarbamylase deficiency are due to novel mutations making it impossible to develop common methods for genetic analysis. However, identification of causative mutations has important implications for diagnosis (particularly prenatal diagnosis), prediction of likely course and outcome and the eventual possibility of gene therapy. As part of a continuing study of ornithine transcarbamylase deficiency, we now report an additional thirty novel mutations in the ornithine transcarbamylase gene, together with a brief summary of their clinical presentations.
A new case of multiple mitochondrial enzyme deficiencies with decreased amount of heat shock protein 60
Authors: Briones P. , Vilaseca M. A. , Ribes A. , Vernet A. , Lluch M. , Cusi V. , Huckriede A. , Agsteribbe E. 
Published: December 2002

AbstractHeat shock protein 60 (hsp60) is a mitochondrial matrix protein involved in the folding and correct assembly of polypeptides into complex mitochondrial enzymes. Its deficiency has recently been described as the most likely primary cause of congenital lactic acidaemia with multiple mitochondrial enzyme deficiencies in a female patient. We describe a new case of a girl with a substantially decreased amount of hsp60 in cultured fibroblasts. She presented from birth with hypotonia, unusual facial features, feeding difficulties and failure to thrive. Death occurred at age 4.5 years. Biochemical findings included metabolic acidosis with lactic acidaemia, hyperammonaemia and intermittent ketosis. In contrast to the previously reported case, organic acid analysis showed an altered profile throughout her life. In agreement with this profile, various mitochondrial enzyme activities were deficient in cultured fibroblasts, including enzymes of the respiratory chain and the Krebs cycle, the pyruvate dehydrogenase complex and the mitochondrial biotin‐dependent carboxylases. Fibroblast mitochondria showed ultrastructural abnormalities, were swollen, and were mainly localized around the nucleus.The description of a second case of multiple mitochondrial enzyme deficiencies with reduced amount of hsp60 supports the idea that hsp60 deficiency might be a more common cause of mitochondrial disease. This opens new possibilities for the diagnosis and understanding of congenital lactic acidaemia.
Inborn errors of the purine nucleotide cycle: Adenylosuccinase deficiency
Authors: Van den Berghe G. , Vincent M. F. , Jaeken J. 
Published: December 2002

AbstractAdenylosuccinase catalyses two reactions in purine metabolism: the conversion of succinylaminoimidazole carboxamide ribotide (SAICAR) into amino‐imidazole carboxamide ribotide (AICAR) along the de novo synthesis of purine nucleotides, and the conversion of adenylosuccinate (S‐AMP) into AMP in the conversion of IMP into AMP. The hallmarks of adenylosuccinase deficiency are the presence of succinylaminoimidazole carboxamide riboside (SAICAriboside) and succinyladenosine (S‐Ado) in body fluids. These normally undetectable succinyl‐purines are the products of the dephosphorylation, by cytosolic 5′‐nucleotidase, of the two substrates of adenylosuccinase. The clinical picture of the enzyme deficiency is markedly heterogeneous with, as a rule, a profound, but nevertheless variable degree of psychomotor delay, often convulsions and/or autistic features, sometimes growth retardation and muscular dystrophy. The diagnostic tests that can be used for diagnosis, the enzyme and gene defects that have been identified, and the hypotheses that have been put forward to explain the pathophysiology of the disorder are reviewed.
mtDNA depletion and impairment of mitochondrial function in a case of a multisystem disorder including severe myopathy
Authors: Kirches E. J. F. , Winkler K. , Warich‐Kirches M. , Szibor R. , Wien F. , Kunz W. S. , von Bossanyi P. , Bajaj P. K. , Dietzmann K. 
Published: December 2002

AbstractThe ratio of mtDNA and a nuclear reference gene was estimated by Southern blotting in the skeletal muscle DNA of a 3‐year‐old girl who suffered from congenital brain damage, focal epilepsy, hepatomegaly, malabsorption syndrome and severe myopathy. The signal ratio of mtDNA versus 18S rDNA was 22% of the mean value obtained from controls. No major deletions or insertions were found and the MERRF, MELAS and NARP mutations were ruled out. Mitochondrial DNA‐encoded enzyme activities and mitochondrial respiration were reduced. The analysis of the NAD(P)H and flavoprotein redox states of intact fibres revealed the presence of mitochondrial dysfunction. In tissue sections a moderate elevation of type I and type II fibre diameter variation was detected, aberrant NADH‐ and succinate dehydrogenase staining and some ragged red fibres. This suggested that a mitochondrial disorder caused by a decrease in the amount of intact wild‐type mtDNA was responsible for the severe myopathy.
Neuropsychological outcome of experimental manipulation of phenylalanine intake in treated phenylketonuria
Authors: Griffiths P. , Ward N. , Harvie A. , Cockburn F. 
Published: December 2002

AbstractBlood phenylalanine concentrations were experimentally increased for 3 months by means of a phenylalanine‐complemented amino acid supplement in a group of 16 children aged 10‐16 years with classical phenylketonuria who had been treated early and who had remained on the restricted diet. Average concentrations achieved during challenge were between 1000 and 1300 µmol/L. Psychological outcome was measured by a neuropsychological battery consisting of tests of verbal and spatial memory, attention and fine motor coordination. A triple‐blind, repeated measures, randomized, crossover design was adopted to control for practice and expectancy effects. Subjects were assessed at baseline and at the end of the first and second phenylalanine manipulation periods. Significant interactions (ANOVA) emerged as predicted for phenylalanine concentrations, but similar crossover effects were not found for any of the neuropsychological tests. The results suggested that medium‐term hyperphenylalaninaemia in treated PKU is not harmful to psychological functioning in older children and adolescents who have been continuously treated up to and beyond age 10 years, though the susceptibility of executive functions needs to be further researched. The findings add some weight to the idea that by late childhood the vulnerability of the nervous system to the neurotoxic influence of phenylalanine may be much reduced.
Treatment with low‐dose diazoxide in two growth‐retarded prepubertal girls with glycogen storage disease type Ia resulted in catch‐up growth
Authors: Nuoffer J. M. , Mullis P. E. , Wiesmann U. N. 
Published: December 2002

AbstractTwo originally prepubertal girls suffering from glycogen storage disease type Ia and short stature were treated with low‐dose diazoxide (3‐4.8 mg/kg per day) for 7 and 4 years, respectively. Both showed an impressive catch‐up growth following this treatment. This appeared to be due to prolongation of normoglycaemia after meals and reduction of fasting lactic acidosis by diazoxide.
Assessment of homocysteine status
Authors: Refsum H. , Fiskerstrand T. , Guttormsen A. B. , Ueland P. M. 
Published: December 2002

AbstractPlasma total homocysteine (tHcy) determination is used in the diagnosis of homocystinuria, in cobalamin and folate deficiency and in cardiovascular risk assessment. However, determination of tHcy includes many pitfalls which complicate the assessment of homocysteine status. In the present article, we review basic knowledge for a rational use of plasma tHcy in diagnostic as well as scientific work. The subjects dealt with are procedures for sample handling and processing, the principles of tHcy analyses, and genetic and acquired determinants of the plasma tHcy concentration.
Treatment products and approaches for phenylketonuria: improved palatability and flexibility demonstrate safety, efficacy and acceptance in US clinical trials
Authors: Prince A. P. , McMurry M. P. , Buist N. R. M. 
Published: December 2002

AbstractA new amino acid formulation and a variety of treatment products incorporating it were evaluated for long‐term safety, efficacy, and acceptance in 25 subjects with phenylketonuria over a period of 5 years. Palatability of the treatment was improved by reducing the required intake of amino acids, reformulating the mixture to have better taste, and providing vitamins and minerals as tablets. The hypotheses were that these strategies would improve compliance and metabolic control and maintain nutritional status in subjects. Compliance with treatment was determined from mean reported intakes (4‐day diet records) and from mean ‘received’ intakes using receipts of treatment products actually shipped to individuals upon request. Mean amino acid intakes prescribed were significantly reduced from study entry to end, from 1.2 g/kg to 0.7 g/kg (p < 0.001). Reported intakes were similarly reduced from 1.3 g/kg to 0.7 g/kg (p < 0.001). While actually ‘received’ intakes of amino acid formula were also significantly reduced (p < 0.001), intakes by this measure were much lower than either prescribed or reported, 0.9 g/kg at entry and 0.4 g/kg at the end of the study, suggesting that acceptance of the treatment (usage of products), even when made more palatable, is below clinical expectations. In spite of these findings, mean serum proteins and minerals, height and weight were not significantly reduced during the study, supporting the safety of lowered intakes of amino acids and of nutritionally incomplete products. While the increase in mean serum phenylalanine concentration from 0.38 to 0.48 mmol/L was significant (p < 0.03), this mean rise of 0.1 mmol/L during a corresponding mean age increase of 4.2 years (from 6.9 to 11.1 years) is lower than in other recent reports from longitudinal studies of outcomes during this age range in subjects treated with traditional products. These data support the safety and efficacy of a more palatable and flexible approach to treatment.
Huntington disease: Advances in molecular and cell biology
Authors: Jones A. L. , Wood J. D. , Harper P. S. 
Published: December 2002

AbstractHuntington disease is an inherited neurodegeneration, for which the associated mutation was isolated in 1993. The mutation is an expansion of a CAG trinucleotide repeat, which translates to give a polyglutamine tract at the N‐terminus of a large protein, huntingtin. Neither the normal nor the pathogenic functions of this protein have been identified, but it is clear that pathogenesis is mediated through the expanded polyglutamine tract within the protein, and that polyglutamine is toxic to cells. A number of proteins which interact with the N‐terminal region of huntingtin have been isolated, but this has not, so far, yielded a rationale for pathogenesis. Huntingtin is found in areas of the brain that degenerate in this disease, but is also associated with pathogenic inclusions in Alzheimer disease and Pick disease. It is possible that Huntington disease has pathogenic mechanisms in common with these other neurodegenerative diseases, and that the mechanism may relate to the formation of abnormal, cytoskeletal‐associated, inclusions within cells.
Social factors and the meaning of food in adherence to medical diets: results of a maternal phenylketonuria summer camp
Authors: Waisbren S. E. , Rokni H. , Bailey I. , Rohr F. , Brown T. , Warner‐Rogers J. 
Published: December 2002

AbstractA Maternal PKU camp provided education and social support for 25 young women with phenylketonuria (PKU). Questionnaires were administered and blood samples were collected on the first and last days of camp to evaluate the psychological and medical impact of the programme. Long‐term outcome was assessed through telephone interviews 7 ‐ 14 months later. Knowledge of maternal PKU and the maternal PKU diet increased significantly. There was a significant increase in campers' ratings of the degree to which others supported the use of birth control to prevent late‐treated pregnancies, although campers' comfort with contraception did not change. Mean blood phenylalanine concentrations were significantly reduced by 37% during camp and by 20% at follow‐up. Ninety‐six per cent of campers remained in contact with other campers after the summer. At follow‐up, one pregnancy was reported, in which metabolic control was achieved prior to conception. Overall, attitudes about treatment and perceptions about ability to cope with PKU did not change to a significant degree. It is suggested that camps may be most successful in changing both behaviour and attitudes if they actively involve the campers in food preparation, address the psychological meaning of food in our culture, and provide social support.