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Biomedical subjects

M Baumann

Publications and source records attributed to M Baumann.

322 records · Page 18Linked to original sources

Developmental changes in the expression of neuronal ceroid lipofuscinoses-linked proteins.

Neuronal ceroid lipofuscinoses (NCL) form a distinct group of storage diseases where the normal development of the central nervous system is interrupted and neurons of the neocortex begin to degenerate. Mutations in genes encoding three lysosomal enzymes are the causes for three early-onset forms of NCLs: palmitoyl-protein thioesterase 1 (PPT1) is deficient in human infantile NCL, tripeptidyl peptidase 1 (TTP1) in late-infantile NCL, and cathepsin D in congenital ovine NCL. We wanted to compare the developmental expression profiles of these enzymes in rat brain. In conclusion, the PPT1 expression pattern differed from the two other lysosomal enzymes implicated in NCL diseases, thus suggesting a distinctive role for PPT1 in brain development.

Aminopeptidases↗

[Flow cytometric characterization of maturation processes and primitive stem cell population in pre-B-cell ALL in childhood].

Bone marrow and peripheral blood from children with acute lymphoblastic leukemia was analyzed by flow cytometry to assess leukemic cell differentiation and to characterize the profile of cell surface marker expression on rare CD34+ cell populations. The goal of this study was to determine if patterns of cell surface antigens could be identified on CD34+ subpopulations which may allow distinction between normal and leukemic stem cells. Expression of the progenitor cell antigen CD34 on leukemic blasts was very heterogeneous and varied between 0.5 and 100% in 20 patients analyzed in this study. In cALL and pre-B-ALL, a variable percentage of the leukemic cells coexpressed CD20 in addition to CD10. Only in one case, differentiation characteristic for normal B cell development with coordinated downregulation of CD10 with increasing expression of CD20 was observed. By analysing 5 x 10(6)-1 x 10(6) cells, a CD34+ cell population could be identified in 8 out of 8 patients which did not express CD19 and comprised less than 0.1% of all bone marrow or peripheral blood cells. Within this population, there was differentiation from primitive CD34-CD38- to more mature CD34+CD38+ cells. In 4 of these patients, an additional CD34+ population with low expression of CD19 (CD34+CD19lo) was detected. The lack of CD45 expression on the leukemic cells of 2 patients was used as a marker for the leukemic cell clone. In both patients, the CD34+CD19- cells did express CD45 while CD34+CD19lo/+ cells were CD45 negative. This suggests that the CD34+CD19lo cells were part of the leukemic clone and that the CD34+CD38-CD19- cells may represent residual normal primitive hematopoietic cells. In conclusion, flow cytometry allowed identification of primitive CD34+ cell populations in children with ALL, which can now be functionally characterized by transplantation onto immune-deficient mice.

Animals↗

Does lack of Cftr gene lead to developmental abnormalities in the lung?

Lung disease is the major cause of death in cystic fibrosis (CF), but the effect of gene mutation on the morphology of the main structural compartments of the lung is poorly understood. We show here, to our knowledge for the first time, a quantitative comparison of the fine pulmonary structures of cftr mutant versus non-cf mice. Pertinent volumes and surface areas were estimated in 10 homozygous cftrm1HGU mutants and 11 non-cf littermates by unbiased stereology at the light microscopic level. Our data did not reveal any statistical differences between group means for any of the 9 parameters considered. In other words, our data do not supply any significant evidence that the lack of the Cftr gene is accompanied by any developmental abnormalities in the lung, at least as far as the parameters studied are concerned.

Age Factors↗

Early stage shape change of human erythrocytes after application of electric field pulses.

Erythrocytes which receive electric field pulses are subject to poration, fusion and shape changes due to electrodynamic forces, aminophospholipid perturbation and influences on the normal flip-flop process. The shape change characteristics of cells suspended in different media were analysed after application of rectangular electric field pulses from t=11-44 micros and from E=4-8 kV/cm. Albumin is shown to decelerate the echinocyte shape change within the first few seconds after pulse application. The addition of fluoride and vanadate accelerates the shape change due to their inhibiting influence on the aminophospholipid translocase. For both the duration of the field pulse and its field strength, there exist lower threshold values under which no early stage shape change is observable. The activation energy calculated from the dissipative influence of the electric field alone is smaller than expected, indicating the electrodynamic influence on the flip-flop process. Cell shapes were additionally analysed by contour tracing to focus on the echinocyte spicule distribution after pulse application. This image analysis revealed that, with an increase of both pulse duration and field strength, the shape change velocity and the shape change intensity increase.

Buffers↗

Comorbid anxiety and affective disorder in alcohol-dependent patients seeking treatment: the first Multicentre Study in Germany.

The goals of this study were to describe demographic variables, drinking history, and the 6-month prevalence of Axis I comorbidity among alcohol-dependent subjects in GERMANY: The variables: amount of alcohol consumption, age at onset of the first alcohol consumed, age at onset of daily alcohol consumption, age at onset of withdrawal symptoms and number of detoxifications were related to the different comorbid disorders and gender. In this study, 556 patients from 25 alcohol treatment centres were enrolled between 1 January 1999 and 30 April 1999. After a minimum of 10 days of sobriety patients who fulfilled ICD-10 and DSM-IV criteria of alcohol dependence were interviewed for data collection using the Mini-DIPS (German version of the Anxiety Disorders Interview Schedule) and a standardized psychosocial interview. The 6-month prevalence of comorbid Axis I disorders was 53.1%. Among the patients with comorbidity, affective and anxiety disorders were most frequent. Comorbid stress disorder was associated with an early start of drinking, an early beginning of withdrawal symptoms, highest number of detoxifications, and the highest amount of alcohol consumed. Female patients with anxiety disorder consumed more alcohol and started earlier than females without this comorbid disorder. The data do not answer the question of the pathogenesis of comorbid disorders and alcoholism, but indicate that stress disorders in alcoholic patients and anxiety disorders in female alcoholics influence the course and severity of alcoholism.

Adult↗

Lateral spreading of topically applied UV filter substances investigated by tape stripping.

The lateral spreading of topically applied substances is a competitive process to the penetration into the stratum corneum (SC). The penetration of topically applied UV filter substances into the human SC and the lateral spreading were investigated in vivo. Tape stripping in combination with spectroscopic measurements was used to study both processes of two UV filter substances. The concentration of both UV filters was determined inside and outside the application area by varying the application and tape stripping protocol. A spreading of the topically applied substances from the treated to the untreated areas was observed, which caused a concentration gradient. This lateral spreading depends on the time between application and tape stripping and the size of the treated skin area. Significant amounts of topically applied substances were found adjoining the application area, due to the lateral spreading which takes place on the skin surface. In general, the lateral spreading must be considered to be a competitive process when studying penetration processes of topically applied substances. It has to be considered during drug treatment of small limited skin areas and for the interpretation of recovery rates obtained in penetration studies.

Administration, Cutaneous↗

The mutation causing the common apolipoprotein A-IV polymorphism is a glutamine to histidine substitution of amino acid 360.

Apolipoprotein (apo) A-IV is a protein involved in the metabolism of chylomicrons and high density lipoproteins. This protein displays genetic polymorphism due to two main codominant alleles, A-IV1 and A-IV2. We have identified the mutation that leads to this polymorphism. It is caused by a single-base substitution of guanine for thymine in the third base of codon 360. This substitution leads to a glutamine to histidine change. Direct sequencing of amplified DNA from eight subjects in a three-generation pedigree has demonstrated that the guanine to thymine substitution can explain the apo A-IV polymorphism. In 32 unrelated individuals, a correspondence between apo A-IV phenotype determined by isoelectric focusing and genotype determined with Fnu4HI digestion of amplified DNA could be demonstrated. The enzyme lecithin:cholesteryl acyltransferase (LCAT) is activated by apo A-IV. Under our in vitro conditions, the isoprotein apo A-IV 1-1 is a better LCAT activator than is the isoprotein apo A-IV 2-2. A knowledge of the molecular mechanism underlying the apo A-IV polymorphism will help to elucidate the mechanisms involved in LCAT activation.

Amino Acid Sequence↗

A mechanical cycling phenomenon in electrofused eryhrocytes.

We have characterized a reciprocating mechanical oscillation that can easily be detected in a large fraction of electrofused erythrocytes. Under our conditions, up to about 30% of all electrofusion products (e.g. doublet, triplet, and higher) show at least one cycle and up to 10% show only two cycles. A much smaller fraction (about 1-2%) show 5-10 or more cycles before stopping. In fused doublets the oscillation appears as a roughly linear and slow expansion of the diameter of the 'hourglass constriction' or fusion zone which proceeds simultaneously with a slow contraction of the pole-to-pole length. At what appears to be a threshold, the fusion zone diameter shrinks simultaneously with an expansion in the pole-to-pole length. This takes place rapidly (within a few video frames). The change in length is about 10% and is easily observable by video light microscopy. The periodicity is variable (5-60 s) and subsequent periods often decrease substantially in length. For the range studied, the characteristics of the reciprocation do not appear to be dependent on the strength of the electric field pulse. To our knowledge this phenomenon was originally discovered, but not characterized, in another laboratory. Using our protocol, cells were observed to undergo fusion from as soon as 6, to as late as 84 s after the fusogenic electric pulse was applied.

Animals↗

Characteristics of the osmotically induced membrane rupture.

The phenomenon of reciprocating mechanical oscillations of electrofused erythrocytes was used to investigate the mechanical characteristics of ruptures induced in erythrocyte membranes by colloid osmotic pressure. The rupture characteristics follow an exponentially decaying time function. Time constants determined for opening times of ruptures decreased from 5.5 ms at 10 degrees C to 3.8 ms and 2.0 ms at 40 degrees C for the first and the last observable rupture, respectively. Evidence is given that the diameter of the membrane rupture exceeds the size of a haemoglobin molecule. With repetitive membrane rupturing, the ability of the membrane bilayer and associated structures to heal decreases, owing to the reduced ability to withstand pressure gradients. This change allows oscillating doublets to be classified according to one of three groups: group A showing no development in response to swell times, group B showing a continuous decrease in response to swell times, and group C showing a spontaneous decrease in response to swell times. These results suggest that oscillations cease as a result of defects of membrane healing. Calculations of respective temperature ranges are in agreement with temperature ranges for spectrin denaturation. Thus, conclusions obtained from this study suggest that the spectrin network plays a key role in membrane healing processes after mechanical membrane rupture.

Electrophysiology↗

[Liver fluke infection and sarcoptic mange in red foxes in Berlin].

396 red foxes originating from the city of Berlin were examined for opisthorchiid liver flukes and clinical sarcoptic mange between January 1997 and March 1998. Out of 232 (= 58.6%) foxes positive for opisthorchiid flukes 221 animals harboured Metorchis bilis and 70 were infected with Opisthorchis felineus. Pseudamphistomum truncatum was found only in 8 foxes. M. bilis occurred as mono-infection in 154 animals. M. bilis in combination with O. felineus was found in 61 cases. Pure Opisthorchis infection as well as other fluke combinations were found in a small number of animals only. 85 (= 21.5%) foxes showed clinical sarcoptic mange. Liver fluke positive foxes showed a higher mange prevalence than uninfected animals. However, significant associations between flukes and manage were only found when comparing uninfected foxes with those having the highest worm burden. The association of liver flukes and mange could be established for adult female foxes by a significant Odds Ratio of 4.3.

Animals↗

[Autonomy attitudes in the treatment compliance of a cohort of subjects with continuous psychotropic drug administration].

Prescriptions for psychotropic drugs are part of a general practitioner's daily routine. As with all drugs, they need to be controlled by a phenomenon of observance. Respecting prescriptions is in fact a major public health concern. Our problematic is centred on the analysis of the association between observance and autonomy in order to gain a better understanding of the links between the drug, how it is to be taken, and how the patients adapt and control it. Identifying and comparing autonomous practices psychotrope users associated with attitudes put into play by those who claim to observe or not to observe their treatment is the aim of this project. The qualitative analysis of the speech is based on the categorial analysis of the contents of 46 transcriptions of 23 women et 23 men continuous (regular monthly intake for at least 5 years), aged between 50 and 65. The majority live in couples, have professional activities, and are executives. The psychotropes with the largest consumption are: anxiolytics and antidepressors. The average duration of their consumption is more than 17 years. Two types of attitude can be distinguished through the qualitative analyse. The attitudes of non-observers towards the psychotropic drug and dependence show controlled, autonomous acts. Autonomy is an influencing factor in their observation of the prescribed treatment, it is a major component of their non-observance regarding psychotropes; thus our hypothesis is confirmed. The strategy adopted around the medication arises from autonomy of action. Organising the treatment is seen as a sign of autonomy, as taking an initiative in relation to the medical prescription, and not as rebellious, or carefree behaviour, or as a sign of inconsistency. Non-observers seem more to be involved in a step towards self-regulation. Active taking verbs such as stop, diminish, increase , and success verbs succeed the I is greatly used, reinforced in some cases by myself ; this vocabulary situates the patient as an actor facing the drug and shows that he is capable of action. For observers, taking the drug is qualified as regular and some users categorically refuse to bypass the doctor's advice never . Looking for additional information is an act of autonomy. It is found partly with the doctor; but also from the media, the exchanges with the others and the reading of the notes. But talking to other people and reading the information leaflets are more often done by non-observers. Recognizing oneself in the indications and the dosage marked on the leaflet seems to be the first step to adopting the drug so as to know it better and to gain mastery of it. Autonomy is gained through finding alternative, substitutive or complementary solutions with a large share left to herbal medicine and homeopathy. Non-observers seem to be more active than observers in diminishing or stopping taking psychotropes. Affirming one's autonomy is also shown in the direction given to each person's trajectory of life, behaviour referring to it, the projection into the future, and the dynamics of life. These actions underlie a capacity of resistance, non-observers using evocative terms such as taking things in hand , recognizing the while, in certain cases, the need to be supported. This capacity of action is far less present in observers who acknowledge their difficulties in facing up to events. The intentionality and the determination of their behaviour and their choices depend on the autonomy of willpower. Adjusting the amount taken is shown by expressions of intention, and justifies self-regulation. Non-observers direct their behaviour towards a reduction in the medication and commit themselves not to go over a certain amount. Stopping usage is declared as certain , it is planned. On the other hand, it remains unpredictable for observers for whom consumption is linked to the description of a need to have long-lasting health. Observers describe taking their medication as automatic, routine, and easy. A sort of fatality and resignation is attached to the prescription, linked to a negative perception of their health. The medication is at the same time nourishing and destructive . The disagreeable sensations caused by its suppression and the secondary effects appear less important than the benefits to be had from it. Autonomy can be recognized in the type of commitment established with the professional. It can be shown around a prescription negociated for treatment and delivered in mutual agreement. It places the patient in an active partnership. The presence of I and of more frequent active verbs in non-observers shows the role played by the patient. His conversation organizes itself round how the medication is to be taken. Systematic use of the prescription reinforces the instrumental recourse to the doctor for a renewal especially for non-observers. For observers, the prescription is followed despite disagreements. The professional is appreciated for his expertise in advice, how to use the medication . Confidence results from this know-how. The feeling of fear inspired by the psychotrope puts taking the medication into perspective and removes the guilt from non-observance. This process contributes to the patient's carrying on taking the medication. The positive effects found again thanks to the medication strengthen the later's perpetuation. When the patient is asked to participate in the prescription, this participation is described differently in the two groups. In observers, it is understood from the viewpoint of the doctor-patient association with, us and for the other group from the viewpoint of cooperation I, one . In non-observers, a type of delegation is highlighted leave it to be managed , the patient's confidence in the doctor lets him manage his medication under medical control . The autonomy of willpower is shown by the degree of openness to the Other Person. Non-observers have quite open and trendy character traits and give a rather positive image of themselves. These elements are absent from the speech of observers in favour of a negative self-image. The autonomy of willpower shows up in their free expression within the family, and with friends, the patient is freed from the influence of other people. For non-observers it is admitted easily . Observers show reserve through a concern of being discrete; rules of good behaviour do not allow them to speak about their consumption since it lifts the veil on their person and its affects. Two types of attitude can be distinguished: Observers for whom the psychotrope supports them against an unhappy life and is part of a habit which is hidden from other people, they keep to the prescribed doses and don't try to change them, they have absolute confidence in the medical profession; non-observers for whom psychotropes are a crutch which they mistrust. They are conscious of the bad effects and state their intention and their will to control this medication by planning on a reduction in, or even an end to, consumption. In order to give a meaning to the prescription and to avoid too great a feeling of guilt, they legitimize the later by an obligation created by a need, and by an improvement in symptomatology, and they minimize the quantity and the effects of taking the medication. They cooperate with the doctor and are involved in a close relationship with my doctor . They show a certain familiarity to the medication and talk openly about their consumption. Autonomy is a means to responsibility and to valorise a part of the patients in particular those which are non-observing so as to strengthen their capacity to manage their health as best they can. It contributes to a better observance of treatment in as much as autonomous patients are more inclined to negotiate with their doctors. Looking for self-regulatory behaviour allows us a better understanding of those patients non-observers who are willing, and helps them to develop their aptitude to face up to their illness.

Attitude↗

[Medical prescription and consumption of psychotropic drugs: questions on the differences between men and women].

In health sociology and social epidemiology the gender-related differences in psychotropic drug consumption and prescription have not been throughly investigated. The objective of this review of literature is to analyze women's attitudes and behaviour in psychotropic drug consumption, the cultural influence of the patient's role in the doctor-female patient relation. The family, the society and the cultural aspects related to the role of the patient appear to be factors that strengthen the females' behaviour concerning psychotropic drugs. Results reflect that women consume more psychotropic drugs than men do; when they consult, they obtain them more frequently than men do; and doctors prescribe psychotropic drugs more often to women than to men. However many questions persist about the physicians' role: are the differences in prescriber's attitudes and practices related to their gender or to their patients' gender? Do women doctors prescribe more psychotropic drugs than male doctors? Do the former prescribe more to women than to men? If that is the case, what are the social and cultural reasons that account for this difference? Does a specific socialisation of the two genders account majoritarily for this difference?

Culture↗