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Biomedical subjects

F Lang

Publications and source records attributed to F Lang.

At least 559 records · Page 31Linked to original sources

Cell volume regulatory mechanisms in progression of renal disease.

One of the striking morphological features of renal failure is an increase of cell volume. This review explores the role of cell volume regulatory mechanisms in the pathophysiology of progressive renal disease. The case is made that TGF-beta, a major cytokine involved in the development of progressive renal failure, upregulates the transcription of the serum and glucocorticoid-dependent kinase hSGK1, involved in cell volume regulation. Excessive extracellular glucose concentrations stimulate TGF-beta1 expression and thus similarly enhance hSGK1-transcription. The kinase stimulates two mechanisms important for cell volume regulation, i.e. the renal epithelial Na+ channel ENaC and the thick ascending limb Na+,K+,2Cl- cotransporter BSC1. On the one hand, stimulation of renal tubular transport leads to renal retention of Na+, which favours the development of hypertension. On the other, the increase of cell volume stimulates protein synthesis and inhibits protein degradation, contributing to the enhanced net formation and deposition of matrix proteins. At later stages, the increase of cell volume may be reversed to atrophy, and cell death may lead to loss of functional tissue. In conclusion, progressive renal disease is paralleled by deranged cell volume regulatory mechanisms.

Activin Receptors, Type I↗

Erucylphosphocholine-induced apoptosis in chemoresistant glioblastoma cell lines: involvement of caspase activation and mitochondrial alterations.

Intrinsic chemoresistance constitutes a major problem in the therapy of malignant gliomas. In vitro experiments with four astrocytoma/glioblastoma (AC/GBM) cell lines revealed that the chemoresistance of two cell lines, A172 and T98G, to cisplatin and etoposide was due to resistance to drug-induced apoptosis. In contrast, all the AC/GBM cell lines tested were sensitive to treatment with the lipophilic ether lipid erucylphosphocholine, ErPC. ErPC-induced apoptosis was independent of wild-type p53-signaling and triggering of the CD95/CD95 ligand (CD95L) system. Inhibition of protein and RNA synthesis by cycloheximide and actinomycin D did not abrogate ErPC-induced apoptosis. However, expression of members of the bcl-2 protein family was modulated during ErPC treatment. Activation of caspase 3 and mitochondrial alterations were central to ErPC-induced apoptosis. We conclude that ErPC-induced activation of the mitochondrial pathway enables cell death in the chemoresistant AC/GBM cells.

Animals↗

[Baker and Itagliata's Quality of Life Scale in a group of 139 schizophrenic patients: factorial analysis and evaluation of global validity].

The Satisfaction with Life Domains Scale SLDS published by Baker and Intagliata in 1982 and translated in French by Chambon and al. is one of the most used rating scales in the field of Subjective Quality of Life (SQL) for patients suffering from schizophrenia. It comprises 16 scales in 7 points and Likert format exploring the following fields: home/apartment/place of residence, neighbourhood, food, clothes, health, people they live with, friends, love life, relationships with their family, how they get on with other people, job/work day programming, spare time, what they do in the community for fun, services and facilities in their area, economic situation, general quality of life. In this study we present results on SLDS about 139 schizophrenic patients (108 males, 31 females) recruited in two centers Lyon (n = 41) and Saint-Etienne (n = 98). The SLDS was a part of more comprehensive studies including evaluation of needs for care, social support, delivery and costs of services. Diagnosis were confirmed using either the SCAN and CATEGO program (n = 108) or the list of the ICD-10 criteria (n = 31) applied at time of inclusion or on the basis of a representative episode of the illness. Patients were classified in two groups, the S group (S, n = 53) for those patients presenting clinical features at time of inclusion excepted residual forms (F 20.5) and the non S group (N-S, n = 86) for those patients free of symptoms at the time of assessment. Non parametric statistics (U test and Kendall test) were used for comparisons between groups. The field by field comparison of the scores shows the poorest level of SQL for love life (m = 4.2; sd = 1.8) and economic status (m = 4.4; sd = 1.8). Comparisons between S and non-S groups show an average range systematically higher for the non-S group and significant differences for the following fields: food, friends, how they get on with other people. The same comparisons between males and females show no significant differences excepted for the following fields: love life, economic situation. Principal components analysis with Varimax rotation were performed and a 4 factors solution was considered as the best one. Before rotation the first factor accounts for 31% of the variance and comprises all the items with loading higher than 0.4 allowing us to consider the possibility of a global score. This global score is normally distributed (m = 95.1 sd = 17.3) and shows a significant difference between S and non S-groups (S m = 92.2 sd = 20.1; non S m = 99.6 sd = 15.4 p = .02) but not between centers and between males and females. After rotation the first factor comprises relationships with family, how they get on with other people, job/work/day programming, spare time, what they do for fun and life in general. The hypothesis of unidimensionality of QV has to be tested using the RASCH model.

Adult↗

[Validation study of the Depressive Experience Questionnaire].

Sidney Blatt, considering as being insufficient the categorical-symptomatic approach of depression, has worked out a theory of depression and psychopathology that integrates the contributions of psychoanalysis as well as cognitive and developmental psychology. Within a broad psychoanalytic framework, Blatt's formulation focus on the quality of interpersonal relationship, the nature of object representation and early life experiences. Personality development is viewed as the consequence of the interaction of 2 basic developmental tasks: the establishment of the capacity to form stable, enduring, mutually satisfying interpersonal relationships and the achievement of a differentiated, realistic, essentially positive identity. The relationship between these 2 developmental lines involves a complex dialectical process during which progress in each line is essential for progress in the other and which contributes to the development of both a sense of identity and the capacity for interpersonal relatedness. These developmental lines permit not only to define an during individual's primary personality configuration but also enable to identify cognitive structures that are inherent in various forms of psychopathology, including depression. Disruptions at different developmental stages create vulnerability to different subsequent psychological disturbances. Blatt characterised as anaclitic or dependent the axis concerned with interpersonal relationship and as introjective or self-critical the axis concerned with development of the sense of self and identity. Depressive Experience Questionnaire was developed by Blatt et al. to determine the validity of this model of psychopathology which emphazises continuities between normal and pathological forms of depression. The instrument was developed by Blatt et al. by assembling a pool of items describing experiences frequently reported by depressed individual. Sixty-six items were selected and administered to a large nonclinical sample (500 female and 160 male undergraduates). Principal component analysis within sex performed on the answers to DEQ confirmed his assumption in identifying two principal depressive dimensions. The first factor involved items that are primarily externally directed and refer to a disturbance of interpersonal relationships (anaclitism); the second factor consists of items that are more internally directed and reflect concerns about self-identity (self-criticism). A third factor emerged, assessing the good functioning of subject and confidence in his resources and capacities (efficacy). Scales derived from these factors have high internal consistency and substantial test-retest reliability. The solutions for men and women were highly congruent. Factor structure has been replicated in several nonclinical and clinical samples, supporting considerable evidence to the construct validity of the DEQ Dependency and Self-criticism scales. An adolescent form of DEQ (DEQ-A) has successively been developed. Factor analysis revealed three factors that were highly congruent in female and male students and with the three factors of the original DEQ. The reliability, internal consistency and validity of DEQ-A indicate that the DEQ-A closely parallels the DEQ, especially in the articulation of Dependency and Self-criticism as two factors in depression. These formulations and clinical observations about the importance of differentiating a depression focused on issues of self-criticism from issues of dependency are consistent with the formulations of others theorists which, from very different theoretical perspectives, posit 2 types of depression, one in which either perceived loss or rejection in social relationships is central and the other in which perceived failure in achievement, guilt or lack of control serves as the precipitant of depression. These 2 types of experiences have been characterized as dominant other and dominant goal , as anxiously attached and compulsively self-reliant and as sociotropic and autonomous . Our work presents the results of a validation study of both forms of Blatt's questionnaire (for adults--DEQ--and for adolescents--DEQA) translated in French in a large population of normal subjects, aged 15 to 45 years. DEQ and DEQ-A were compared by inspection of items loading strongly on each factor and by correlation of the three factors of adults and adolescents. The exploratory factor analysis of DEQ and DEQA revealed three orthogonal factors, corresponding with Blatt's original dimensions. Consistency and external validity were adequate for all 3 factors of DEQ and DEQ-A. Anaclitism and self-criticism dimensions of DEQ and DEQ-A correlate positively with measures of depression (DSM-IV, Beck Depression Inventory), consistently with the results obtained by Blatt. Differently from this author, anaclitism appears to be less differentiated in males than in females, suggesting that the concept of dependence could assume different relevance for men and women.

Adult↗

A national study of required family medicine clinical rotations.

The authors collected information from each family medicine department with a required clinical rotation. Timing of such rotations are predominantly during the third year (56%), using a combination of family practice centers and community preceptor sites. Formal didactic instructions are offered for a mean of 28 hours. This instruction is offered in combinations of introductory, weekly, and terminal didactic blocks. Most programs (68%) assign reading from an article file, and 51% develop their own examinations. Clinical evaluations represent the largest portion (61%) of final grades, with 30% coming from examinations and lesser amounts from home visits, student presentations, etc. The implications of these findings are discussed.

Clinical Clerkship↗

Resident behaviors during observed pelvic examinations.

The pelvic exam is a procedure frequently complicated by difficult communication, sexual tension, and iatrogenic pain. Observations of family practice residents performing pelvic exams were done to identify ways in which they deal with these issues. Among the majority of residents, there was a failure to identify and deal with patients' discomfort. Several episodes of behavior felt to be dysfunctional to the doctor-patient relationship were observed. Implications of these findings for medical education are discussed.

Adult↗

[Disorders of noradrenergic pathways in anorexia nervosa. Results].

Twelve patients suffering from mental anorexia were examined on clinical and biological grounds, based on the hypothesis of the functional depression of the noradrenergic track. The initial values of MHPG and of catecholamines were below normal. The quantitative results for depression and retardation were lessened significantly under beta-stimulant treatment. Only glucuro-conjugate MHPG excretion increased significantly, but the MHPG values were much lower than normal at the end of the treatment. The correlations between biochemical and behavioural parameters were worth noticing as far as the retardation scale was concerned. The present study shows the advantage of the dexamethasone suppression test and of the response of TSH under TRH.

Adolescent↗

[A problem detected by the AMDP rating of the Mar. case: the relation between phobia and obsession].

The rating of the videotaped interview of the Mar. case during three meetings of the French-speaking section of the AMDP has revealed the problem of the relationships between phobia and obsession. These ratings triggered a critical reflection based on the theoretical framework from the literature, on the clinical material (the videotaped interview) and on the pragmatic difficulties which appeared during the discussions of the ratings.

Aged↗

[Noradrenergic hypothesis in anorexia nervosa: prospective study using beta-stimulant therapy].

We assumed for this study that beta-stimulants could efficient for the treatment of anorexia nervosa not with direct action upon the center of hunger or upon the secretion of insulin but by stimulating the norepinephrine way which is characterized by a function hypotrophy as it is the case in some affective disorder. This experiment was homogenously performed with seven patients. It then presents an encouraging prospective value.

Adolescent↗

[Cartilage and vitamin D in vitro (author's transl)].

Interactions between cartilage and vitamin D metabolism were studied in vitro. Chondrocytes were isolated from rabbit growth plate cartilage and cultured. These cells are able to transform 25-hydroxycholecalciferol in 24, 25-dihydroxycholecalciferol. Metabolic transformation is modulated by 1, 25-dihydroxycholecalciferol but not by parathyroid hormone neither by extracellular calcium concentrations. 24, 25-(OH) 2D3 and 1, 25-(OH) 2D3 are active on the cellular metabolism of cultured chondrocytes in a different way : 24, 25-(OH) 2D3 stimulates the proteoglycan synthesis in "mature" chondrocytes 1, 25-(OH) 2D3 increases DNA polymerase activities in chondrocytes during the logarithmic phase of division. Finally, specific sites of nuclear receptors of 24, 25-(OH) 2D3 are present in chondrocytes.

Animals↗