Biomedical subjects

F Lang

Publications and source records attributed to F Lang.

At least 541 records · Page 30Linked to original sources

PubMedDate not supplied

Evaluating interviewing techniques for the sexual practices history. Use of video trigger tapes to assess patient comfort.

BACKGROUND: Although physicians recognize the importance of assessing a patient's risk for human immunodeficiency virus (HIV) infection, many are reluctant to explore a person's sexual history, a principal determinant of this risk. OBJECTIVE: To examine the feasibility of a research design that uses responses to viewing a videotaped interview as a proxy for how patients might feel if they were interviewed using a specific approach, and to determine comfort levels with a variety of interview approaches for conducting HIV risk assessment. METHODS: Individuals responded to a videotape of several interviewing approaches for HIV risk assessment. Responses to the following aspects were collected: introduction of HIV risk assessment, assessment of patient comfort with the topic, techniques for collecting HIV risk and sexual information, and exploration of sensitive issues not previously identified. Participants expressed levels of comfort by means of a Likert scale to rate their comfort with each approach. RESULTS: Participants expressed higher comfort levels with an introduction that used a ubiquity statement or lifestyle bridge question. Also, they expressed greater comfort when the interviewer addressed how they felt about responding to questions about their HIV risk. Participants reported highest levels of comfort with both patient-centered and closed-ended interviewing techniques. Women were less comfortable with an open-ended interviewing technique. CONCLUSIONS: Individuals have different comfort levels for approaches used to assess HIV risk. This trigger tape experimental design to assess comfort levels for interview techniques is feasible for exploring other aspects of physician-patient communication; additional validation studies are recommended.

Adult↗

PubMedDate not supplied

[Alexithymia, depression and drug addiction].

Alexithymia is a multidimensional concept associating an emotional component focused on the difficulty in identifying and describing feelings and a cognitive one centred on the use of a concrete and poorly introspective way of thinking. Alexithymia can be assessed by self-assessment instruments and in particular by the 20 items version of the Toronto Alexithymia Scale (TAS-20). Depressive disorders have complex relationships with the construct of alexithymia and there exist few experimental works on the subject. Epidemiological studies frequently raise an overlap between alexithymia and depression, in particular in the context of addiction. The main aim of this study was to confirm the high prevalence of alexithymia among drug addicted patients taking into account socio-demographic variables (sex, age, social and economic categories). The second aim of the study was to investigate the relationships between alexithymia and depression among drug addicted patients. A sample of 128 drug addicted patients answering DSM IV criteria of dependence to a psycho-active substance (alcohol excluded) was paired according to socio-demographic variables to a control sample of 128 normal subjects. Diagnostic assessment was made using the Mini International Neuropsychiatric Interview (MINI). Alexithymia and depression were assessed with the TAS-20 and with the short version of the Beck Depression Inventory (BDI-13). The results confirm the high prevalence of alexithymia among drug addicted patients (43.5%) compared to controls (24.6%). This difference is based namely on the emotional component of alexithymia, the cognitive component failing to show any difference between the two samples. Moreover, alexithymia appears to be independent from socio-demographic variables in our sample of drug addicted patients; 66.4% of drug addicted patients presents a depressive symptomatology (which is significantly more important in female patients), compared to 26% of the controls. Studies using the TAS and the BDI with 21 items have shown that from 10 to 20% of the variance of alexithymia is explained by depression. Our own results show a shared variance of 20% between the TAS-20 and the BDI, going in the direction of a moderated correlation between alexithymia and depressive symptomatology. Moreover, when we retain only subjects without depressive symptomatology at BDI, drug addicted (n=42) are not any more alexithymic than controls (n=114). Our results plead for a positive association between depression and alexithymia in drug addicted, depressed or healthy subjects. Alexithymia and depression would be two associated dimensions, the emotional component explaining alone this association. The emotional component of the alexithymia would be thymo-dependent, whereas the cognitive component (externally oriented thought) would be independent and constitute a stable clinical feature. These results are concordant with other studies in the literature suggesting that alexithymia in its emotional component is supported by depression. Alexithymia thus did not appear as an autonomous dimension which would discriminate between drug addicted and controls, independently of the absence of a depressive state. The Authors discuss the complexity of the relationships between alexithymia and depression and the correlations between TAS and BDI scales especially for the factor Difficulty Identifying Feelings. These results deserve further studies. The cross-sectional nature of this study do not allow to establish if alexithymia is a subjacent and preexistent in the form of a psychopathological dimension in addictive behaviours, so supporting its emergence, and/or if it develops once the dependence is installed and chronicized. Longitudinal studies remain to be realised.

Adult↗

PubMedDate not supplied

[Are anxiety or depressive disorders more frequent among one of the anorexia or bulimia nervosa subtype?].

UNLABELLED: Our objective was to answer the following question: are there differences between diagnostic groups of eating disorders (ED) for the prevalence of depressive and anxiety disorders, when clinical differences between the groups are taken into account (ie age of subjects, ED duration, inpatient or outpatient status, and Body Mass Index)? METHOD: We evaluated the frequency of anxiety disorders and depressive disorders in 271 subjects presenting with a diagnosis of either anorexia nervosa or bulimia, using the Mini International Neuropsychiatric Interview (MINI), DSM IV version. We compared the prevalences between sub-groups of anorexics (AN-R and AN-BN), between sub-groups of bulimics (BN-P and BN-NP) and between anorexics and bulimics while adjusting for the variables defined below. RESULTS: Current or lifetime comorbidity of anxiety and depressive disorders did not differ between AN-Rs and AN-BNs, nor between BN-Ps and BN-NPs. Only current diagnoses of agoraphobia and obsessive-compulsive disorder were significantly more frequent in anorexics than in bulimics. CONCLUSION: The greater frequency of comorbidity between obsessive-compulsive disorder and AN compared to BN, already well documented, is not questioned. The remaining anxiety disorders are equally frequent among all the diagnostic types of ED.

Adolescent↗

PubMedDate not supplied

[Is depressive disorder linked to anxiety disorder among anorexics and bulimics?].

UNLABELLED: The primaty objective is to determine whether the presence anxiety disorders is related to depressive comorbidity in subjects suffering from ED, while taking into account certain variables which may be related to depression [subjects' age, ED duration, prior incidents of anorexia nervosa in BN subjects, inpatient or outpatient status, nutritional state (as measured by Body Mass Index or BMI)]. Our secondary objective is to evaluate the relative chronology of the onset of anxiety disorders and depressive disorders in anorexic and bulimic subjects. METHOD: We evaluated the frequency of depressive disorders in 271 subjects presenting with a diagnosis of either anorexia nervosa or bulimia, using the Mini International Neuropsychiatric Interview (MINI), DSM IV version. RESULTS: While univariate analyses show that nearly all anxiety disorders are related to major depressive episode (MDE), a separate analysis of each anxiety disorder reveals that they do not all have the same influence in terms of risk of onset of MDE in anorexics and bulimics, when adjusted for univariate variables related to MDE (subjects' age, ED duration, prior incidents of anorexia nervosa in BN subjects, inpatient or outpatient status, nutritional state). Current generalized anxiety is significantly related to lifetime presence of MDE in AN subjects, and to current MDE in AN and BN subjects. Generalized anxiety is the most frequent disorder in AN and BN subjects to according our study; it also appears to be one of the principal predictive factors for MDE, which is 2.4 to 4.2 times more frequent when GAD is present. Diagnosis of OCD has its own particular effect on lifetime risk for MDE in AN subjects, regardless of GAD: it increases the risk of depression by 3.5. It is one of the most frequent anxiety disorders among AN subjects, present in nearly a quarter of them. In bulimics, when GAD is excluded, two factors are related to current diagnosis of MDE: panic disorder and subjects' inpatient or outpatient status. Hospitalized bulimics are diagnosed with current MDE 4.4 times more often than those seen as.

Adult↗

PubMedDate not supplied

Human parvovirus B19: a new emerging pathogen of inflammatory cardiomyopathy.

The human parvovirus B19 (PVB19), an erythrovirus causing diverse clinical manifestations ranging from asymptomatic or mild to more severe outcomes such as hydrops fetalis, is the only known human pathogenic parvovirus so far. Although enteroviruses have long been considered the most common cause of inflammatory cardiomyopathy, PVB19 is emerging as a important candidate. Recent studies have indicated an association of PVB19 with paediatric and adult inflammatory cardiac disease. However, whether or not PVB19 has an impact on inflammatory cardiomyopathy in adult patients is still unclear. The first hints for a possible aetiopathogenetic role of the PVB19-infection and the development of cardiac dysfunction were demonstrated by molecular biology utilizing in situ hybridization (ISH) and polymerase chain reaction (PCR). According to available evidence, PVB19-associated inflammatory cardiomyopathy is characterized by infection of endothelial cells of small intracardiac arterioles and venules, which may be associated with endothelial dysfunction, impairment of myocardial microcirculation, and penetration of inflammatory cells into the myocardium.

Cardiomyopathy, Dilated↗

PubMedDate not supplied

Osmotic shock-induced suicidal death of erythrocytes.

Osmotic shock triggers eryptosis, a suicidal death of erythrocytes characterized by cell shrinkage, cell membrane blebbing and phosphatidylserine exposure at the cell surface. Phosphatidylserine-exposing erythrocytes are recognized by macrophages, engulfed, degraded and thus cleared from circulating blood. Eryptosis following osmotic shock is mediated by two distinct signalling pathways. On the one hand, osmotic shock stimulates a cyclooxygenase leading to formation of prostaglandin E2 and subsequent activation of Ca2+-permeable cation channels. On the other hand, osmotic shock activates a phospholipase A2 leading to release of platelet activating factor, which in turn activates a sphingomyelinase and thus stimulates the formation of ceramide. The increased cytosolic Ca2+ concentrations on the one hand and ceramide on the other trigger phospholipid scrambling of the cell membrane with the subsequent shift of phosphatidylserine from the inner to the outer cell membrane leaflet. Ca2+ further activates Ca2+-sensitive K+ channels leading to cellular KCl loss and further cell shrinkage. The cation channels are inhibited by Cl- anions, erythropoietin and dopamine. The sphingomyelinase is inhibited by high concentrations of urea. Thus, the high Cl- and urea concentrations in renal medulla presumably prevent the triggering of eryptosis despite hyperosmolarity. The mechanisms involved in eryptosis may not only affect the survival of erythrocytes but may be similarly operative in nucleated cells exposed to osmotic shock.

Animals↗

PubMedDate not supplied

Effect of hepatocyte swelling on microtubule stability and tubulin mRNA levels.

Incubation of isolated rat hepatocytes under conditions known to induce cell swelling caused several alterations in microtubule physiology. As shown by immunofluorescence microscopy experiments in the absence and presence of triethyllead or colchicine (two well-established microtubule inhibitors), an apparent stabilization of the microtubule network became evident in hepatocytes exposed to hypotonic (190 mosmol/L) conditions. A similar stabilizing effect was also observed upon cell swelling induced by addition of insulin (100 nmol/L) or glutamine (10 mmol/L). The differential microtubule stabilities were not attributed to a differential incorporation of the antimicrotubular agents into hepatocytes as shown by [3H]colchicine-uptake experiments. The swelling-induced alterations of microtubules may contribute to the swelling-induced changes of liver cell function: in perfused rat liver it was found that the established inhibitory effect of hypotonic cell swelling on hepatic proteolysis was largely abolished in presence of colchicine. Tubulin mRNA levels increased by 1.9-, 2.1- and 2.7-fold in isolated hepatocytes being exposed for 120 min to hypotonic medium, insulin, or glutamine, respectively. The results suggest an involvement of microtubular structures in the regulation of liver metabolism in response to alterations of the cellular hydration state.

Animals↗

PubMedDate not supplied

Body dissatisfaction and its interrelations with other risk factors for bulimia nervosa in 12 countries.

BACKGROUND: It is widely accepted that risk factors for bulimia nervosa, mainly body dissatisfaction, are dependent on cultural factors. However, to date few studies have compared data from different cultures with an appropriate methodology. Therefore we aimed to gather reliable information on body dissatisfaction and other risk factors for bulimia from different nations and to reveal their functional interrelations. METHODS: A series of 10 silhouettes, designed to be as far as possible free from cultural and other detailed aspects, was shown to 1,751 medical and nursing students in 12 nations. A functional model was applied to each sample and tested by structural equation methodology. RESULTS: The most extreme body dissatisfaction was found in northern Mediterranean countries, followed by northern European countries. Countries currently undergoing a process of westernization show an intermediate amount of body dissatisfaction, and non-western countries demonstrate rather low values. Body dissatisfaction is the most important influence on dieting behaviour in most countries. CONCLUSIONS: Despite ongoing adoption of western values worldwide, we observe remarkable differences in body dissatisfaction between different cultures. That body dissatisfaction seems disturbingly partly detached from the actual BMI, i.e. possible overweight, as well as from feelings of low self-esteem in some western countries, raises new questions about the possible origin of the pressure to be thin.

Adolescent↗

PubMedDate not supplied

Repair of non-circumferential cervical trachea defects by three different latissimus dorsi flaps. A comparative studyin an experimental setting.

BACKGROUND: Large intrathoracic airway defects may be closed using a pedicled latissimus dorsi (LD) flap, with rewarding results. This study addresses the question of whether this holds true for extrathoracic non-circumferential tracheal defects. METHODS: A cervical segment of the trachea of 4 x 1 cm was resected in 9 white male pigs. The defect was stented with a silicone stent for 3 months and closed either by an LD flap alone (group a, n = 3), an LD flap with an attached rib segment covered by pleura (group b, n = 3), or an LD flap reinforced by a perforated polylactide (MacroPore) plate (group c, n = 3). The trachea was assessed by rigid endoscopy at 3 and 4 months and histologically at 4 months postoperatively. RESULTS: The degree of stenosis at the level of the reconstruction at 4 months was 25, 50 and 75% in group a, 15, 50 and 60% in group b, and 20, 95 and 95% in group c, respectively. The percentage of the defect covered by columnar epithelium was 100% in all animals of group a, 60, 100 and 100% in group b, and 10, 0 and 0% in group c. Resorption of the rib was seen in all animals of group b and obstructive inflammatory polyps were found in 2 animals of group c. CONCLUSION: Pedicled LD flaps provided less satisfactory results for closure of large non-circumferential extrathoracic airway defects than observed after intrathoracic reconstruction. A pedicled rib segment added to the LD flap did not improve the results obtained from LD flap repair alone, and an embedded MacroPore prosthesis may result in severe airway stenosis due to plate migration and intense inflammatory reaction protruding into the tracheal lumen.

Animals↗

PubMedDate not supplied

Cell volume regulation in renal cortical cells.

Both proximal renal tubule cells and cultured Madin-Darby canine kidney (MDCK) cells are capable of regulating their volume in hypotonic media. Regulatory cell volume decrease in proximal straight tubules is impaired by barium, amiloride and acetazolamide and depends on the presence of bicarbonate and of sodium, whereas it is unaffected by complete removal of extracellular chloride. The observations may point to parallel loss of potassium through potassium channels as well as of bicarbonate and sodium via a bicarbonate-sodium cotransport. Alternatively, potassium/hydrogen ion exchange or potassium bicarbonate cotransport could be involved. In MDCK cells, exposure to hypotonic media apparently leads to the activation of an anion channel, while potassium conductance is rather decreased. In both proximal tubules and MDCK cells, volume regulatory decrease is possibly triggered by leucotrienes, which may be released during cell swelling. Cell volume is altered in a variety of conditions even at isotonic extracellular fluid and cell volume-regulatory mechanisms are likely to participate in regulation of renal transepithelial transport.

Animals↗

PubMedDate not supplied

Cell volume regulation in liver.

The maintenance of liver cell volume in isotonic extracellular fluid requires the continuous supply of energy: sodium is extruded in exchange for potassium by the sodium/potassium ATPase, conductive potassium efflux creates a cell-negative membrane potential, which expelles chloride through conductive pathways. Thus, the various organic substances accumulated within the cell are osmotically counterbalanced in large part by the large difference of chloride concentration across the cell membrane. Impairment of energy supply leads to dissipation of ion gradients, depolarization and cell swelling. However, even in the presence of ouabain the liver cell can extrude ions by furosemide-sensitive transport in intracellular vesicles and subsequent exocytosis. In isotonic extracellular fluid cell swelling may follow an increase in extracellular potassium concentration, which impairs potassium efflux and depolarizes the cell membrane leading to chloride accumulation. Replacement of extracellular chloride with impermeable anions leads to cell shrinkage. During excessive sodium-coupled entry of amino acids and subsequent stimulation of sodium/potassium-ATPase by increase in intracellular sodium activity, an increase in cell volume is blunted by activation of potassium channels, which maintain cell membrane potential and allow for loss of cellular potassium. Cell swelling induced by exposure of liver cells to hypotonic extracellular fluid is followed by regulatory volume decrease (RVD), cell shrinkage induced by reexposure to isotonic perfusate is followed by regulatory volume increase (RVI). Available evidence suggests that RVD is accomplished by activation of potassium channels, hyperpolarization and subsequent extrusion of chloride along with potassium, and that RVI depends on the activation of sodium hydrogen ion exchange with subsequent activation of sodium/potassium-ATPase leading to the respective accumulation of potassium and bicarbonate. In addition, exposure of liver to anisotonic perfusates alters glycogen degradation, glycolysis and probably urea formation, which are enhanced by exposure to hypertonic perfusates and depressed by hypotonic perfusates.

Animals↗

PubMedDate not supplied

Volume-regulatory potassium release from isolated perfused rat kidney.

The present study has been performed to test for cell volume regulatory potassium release from the isolated perfused rat kidney exposed to hypotonic perfusate and for its sensitivity to potassium channel blocker barium and calcium channel blocker verapamil. Replacement of 25 mmol/l NaCl with 50 mmol/l mannitol has little effect on effluent potassium activity, whereas subsequent omission of mannitol from the perfusate leads to a transient increase of effluent potassium activity, reflecting volume regulatory potassium release. Barium (1 mmol/l) leads to a marked transient decrease of effluent potassium activity, pointing to net cellular uptake of potassium. Verapamil (1 mumol/l) leads to a slight decrease of effluent potassium activity. Both barium and verapamil virtually abolish the rapid, transient increase of effluent potassium activity upon exposure to hypotonic perfusates. Thus, the substances either block or markedly retard volume regulatory potassium release. The apparent renal vascular resistance is transiently increased by exposure to hypotonic perfusates and by barium, but is reduced by verapamil. Cell volume regulation of isolated perfused mouse straight proximal tubules is retarded but not abolished by verapamil (0.1 mmol/l). In conclusion, cellular potassium release from rat kidney can be determined by continuous measurement of effluent potassium activity. The volume regulatory potassium release and cell volume regulation are impaired by both barium and verapamil. The persisting cell volume regulation could be due either to slow potassium release and/or some mechanism independent of potassium.

Animals↗

PubMedDate not supplied

Ion channels in Madin-Darby canine kidney cells.

Ion channels in Madin-Darby canine kidney cells serve transepithelial chloride transport and probably cell volume regulation. Three distinct potassium channels and one anion channel have been revealed by patch clamp studies in Madin-Darby canine kidney cells. The potassium channels are activated by an increase in intracellular calcium activity. A number of hormones activate the potassium channels by an increase in intracellular calcium activity. However, under certain conditions the hormones hyperpolarize the cell membrane without increasing intracellular calcium activity sufficiently to activate the calcium-sensitive potassium channels. Thus, the hormones may activate potassium channels via another, as yet undefined, intracellular mechanism. The anion channel is stimulated by cAMP. Another factor modifying channel activity is cell volume: cell swelling leads probably to subsequent activation of potassium and anion channels. The net result is a variable transient hyperpolarization followed by a sustained depolarization of the cell membrane.

Animals↗

PubMedDate not supplied

The biological significance of cell volume.

To survive, cells have to avoid excessive alterations of their volume. To this end, cells have developed a complex machinery of cell volume regulatory mechanisms comprising transport across the cell membrane and metabolism. Upon cell swelling, they loose electrolytes mainly via selective K+ channels and unselective ion channels and/or KCl symport, upon cell shrinkage they accumulate ions by Na+,K+,2Cl- cotransport and parallel operation of Na+/H+ exchange and Cl-/HCO3- exchange. In addition, cell shrinkage stimulates glycogenolysis, proteolysis and formation of organic osmolytes such as amino acids, methylamines and polyols. Cell swelling stimulates formation of glycogen and proteins and cellular release of organic osmolytes. Alterations of cell volume do play a crucial role in the regulation of cell function, as illustrated by four examples: 1. Epithelial transport may lead to cell swelling, which then triggers volume regulatory mechanisms modifying transcellular transport. 2. Insulin swells hepatocytes by activation of Na+,K+,2Cl- cotransport and Na+/H+ exchange, glucagon shrinks those cells by activation of ion channels. The respective volume changes participate in the regulation of cellular protein and glycogen metabolism by these hormones. 3. Growth factors and expression of ras oncogene activate Na+,K+,2Cl- cotransport and Na+/H+ exchange, leading to the respective cell swelling. 4. Hepatocyte swelling triggers a hepatorenal reflex decreasing renal blood flow.

Animals↗

PubMedDate not supplied

Mixed venous PO2 during exercise in patients with different cardiopulmonary function.

The mixed venous PO2(PvO2) as a parameter of peripheral O2 supply correlates at rest and during exercise with the coefficient of oxygen delivery (COD = CaO2 x CO/VO2). PvO2 is determined by the O2 capacity, pulmonary and cardiac function. Values under 34 mm Hg at rest and a pronounced drop of PvO2 during exercise indicate a restriction of either pulmonary or cardiac function or both. The effect of respiratory disorder on PvO2 is striking only when the PaO2 is below 65 mm Hg. Besides PvO2, the meaning of the mean peripheral O2 capillary pressure (PacO2) for the peripheral O2 supply should also be considered.

Heart↗

PubMedDate not supplied

Transcatheter embolization of multiple pulmonary artery aneurysms in Behçet's syndrome. Report of a case.

Transcatheter embolization of a pulmonary artery aneurysm in Behçet's disease has rarely been attempted. A report is presented of a case with four pulmonary aneurysms and massive hemoptysis. Transcatheter embolization was successfully performed in three of these aneurysms, with clinical improvement during a follow-up period of 11 months. Technical problems, hazards, and indications for embolization in these patients are discussed.

Adult↗

PubMedDate not supplied

Comparison of macrophage phospholipid radiolabelling methods for measuring phospholipase A2 inhibition.

Rat peritoneal macrophages activated by ionophore A 23187, were labelled after introduction in the culture medium of 1-0-stearoyl 2-0-[3H] arachidonylglycero-3-phosphocholine (as unique source of tritiated arachidonic acid), or [3H] arachidonic acid which was esterified by cells in phospholipids and triglycerides or remained non esterified. With either cell-labelling method, stimulated macrophages produced tritiated nonesterified fatty acids and eicosanoids which were isolated from cell and medium lipids. When introduced into the culture medium at 1, 5 or 10 microM, the membrane phospholipid analogue 1,2 di-O-hexadecylglycerophosphocholine (dihexadecyl-GPC), but not the lysolecithin analogue 1-0-octadecyl 2-0-methylglycero phosphocholine, lowered phospholipase A2 activity with either labelling method. Dihexadecyl-GPC had an inhibitory effect on the release of arachidonic acid and eicosanoids. Moreover, this effect, as measured by tritiated nonesterified fatty acid formation, was greater in activated cells labelled with tritiated phospholipid (IC50 6 microM) than with [3H] arachidonic acid (IC50 60 microM). This is attributable to the inhibitory effect of dihexadecyl-GPC on endogenous phospholipase A2 and the endogenous enzyme excreted together with lysosomes into the medium. It may be concluded that radioactive phospholipid labelling is a sensitive method for measuring phospholipase A2 activity and assessing the effects of potential phospholipase inhibitors.

Animals↗

PubMedDate not supplied

[Atypical antipsychotics].

This paper synthetizes important information concerning principal atypical antipsychotic drugs actually used in clinical practice: classification, pharmacokinetics, therapeutic uses, side effects, contra-indications and drug interactions. These molecules have heterogeneous structures, but are more and more used because of good neurological tolerance, greater efficacy against negative symptoms, and for clozapin greater efficacy against resistant schizophrenia.

Antipsychotic Agents↗