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Biomedical subjects

C Meyer

Publications and source records attributed to C Meyer.

At least 613 records · Page 34Linked to original sources
PubMedDate not supplied

Max Linde, MD, a Luebeck ophthalmologist and patron of Edvard Munch.

Ophthalmologist Maximilian Linde (1862-1940) had a passion for contemporary art and owned one of the most important private collections in Europe. He first met little known Norwegian expressionist Edvard Munch in 1903, recognized special talent, and welcomed him into his family. With Linde's encouragement, patronage, and friendship, Munich became one of the most important artists of his time. Many of Munch's works were commissioned by Linde and many featured Linde and his family as subjects.

Germany↗
PubMedDate not supplied

Motivation to change drinking behavior: comparison of alcohol-dependent individuals in a general hospital and a general population sample.

The general hospital would be especially suited to initiate interventions if hospitalized alcohol-dependent individuals were particularly motivated to change their drinking behavior. This study compares the readiness to change of alcohol-dependent persons in the general hospital and the general population. Stages of change according to the model of Prochaska and DiClemente [6] are assessed using the Readiness to Change Questionnaire (RCQ) in two representative samples: 118 alcohol-dependent subjects admitted to a general hospital (sample 1) and 50 alcohol-dependent individuals in the general population (sample 2). In sample 1, alcohol-dependent persons were identified in 1167 consecutive admissions using screening questionnaires and a diagnostic interview (SCAN). In sample 2, alcohol dependence was assessed in 4075 individuals using a German version of CIDI. The distribution of stages of change differed significantly (p < 0.0001) between the groups, revealing a shift towards higher stages in the hospital subjects. Logistic regression analysis revealed that the stages of readiness to change and age contributed in predicting whether subjects belonged to the general hospital or the general population sample. Findings suggest that the general hospital is a suitable site to initiate interventions for alcohol-dependent individuals.

Adult↗
PubMedDate not supplied

Cloning and gene structure of the rod cGMP phosphodiesterase delta subunit gene (PDED) in man and mouse.

Rod-specific cGMP phosphodiesterase (PDE) is a key enzyme of the phototransduction cascade, and mutations in its catalytic subunits have been associated with retinal degenerative diseases. The bovine delta-subunit solubilises the normally membrane-bound PDE and is the only subunit expressed in extraocular tissues. We isolated the human and mouse orthologs, and found 78% identity at the DNA level and 98% identity at the protein level. The Caenorhabditis elegans homolog shows 69% identity at the protein level. The human PDED gene consisted of 5 exons spanning at least 30 kb of genomic DNA. Northern blot analysis showed a 1.3 kb transcript in human retina, heart, brain, placenta, liver, and skeletal muscle. Fluorescence in situ hybridisation (FISH) and radiation hybrid mapping localised the human PDED gene to chromosome 2q37. A preliminary screen of all 5 exons in 20 unrelated patients with autosomal recessive retinitis pigmentosa revealed no PDED mutations.

3',5'-Cyclic-GMP Phosphodiesterases↗
PubMedDate not supplied

[Promoting the intention to quit smoking among patients in family medicine practice].

BACKGROUND: General practitioners can reach large number of smokers. Their good interpersonal relationship with patients promises successful guidance with regard to smoking. However, little is known about the accessibility of smokers to intervention in general practice and about the motivation to abandon smoking. There is a lack of information concerning the GPs' perceived responsibility for smoking counselling. The goal of the study is to examine to what extent smokers can be advised in general practice and how GPs' assess the practicability of such counselling. METHODS: The sample consisted of consecutive general practices patients. A random sample of 39 GPs was drawn and 34 took part in the study. Of 3434 patients, 99.7 % participated in the screening procedure. Inclusion criteria (age 18 to 70 years, admitted smokers), were met by 551 subjects. The participation rate was 81.4 % (n = 449). All GPs received a single training session. Counselling was tailored to the motivation to quit. More than 60 % of the patients were not motivated to stop smoking. RESULTS: Following the study design, 87.8 % of all smoking patients were counselled by GPs. A total of 79.3 % among the GPs considered the intervention to be practicable. CONCLUSIONS: Despite a low motivation to quit smoking in the general practice, 80 % of the smoking patients can be reached by interventions. Furthermore, since the agreement of the GPs concerning practicability was almost 80 %, measures should be initiated to promote counselling for all smokers within the scope of medical consultation.

Adolescent↗
PubMedDate not supplied

[Osteochondrosis dissecans of concave joint surfaces: roof of shoulder joint, tibial plateau, distal tibia].

Typically an osteochondrosis dissecans occurs in the region of a convex articular surface, the most frequently localisation observed being the medial femoral condyle. Only few cases of an osteochondrosis dissecans in concave articular surfaces have been reported; these involved the tibial plateau, the distal tibia and the proximal surface of the navicular bone. Two more cases with an osteochondrosis dissecans in the proximal and distal tibial epiphysis are reported and additionally a hitherto unreported localisation in the glenoid fossa of the scapula. True osteochondrosis must be differentiated from ossification variants.

Adolescent↗
PubMedDate not supplied

Vitamin K in combination with other biochemical markers to diagnose osteoporosis.

The significance of a multiparametric classification approach of vitamin K is analysed to differentiate premenopausal (CTRL), postmenopausal non-osteoporotic (nOSP) and osteoporotic (OSP) women. Data records of women between 28 and 74 years of age were used for evaluation. Bone mineral density was determined by quantitative computed tomography of the lumbar spine using the T-score to diagnose osteoporosis. Vitamin K and biochemical markers of bone formation and resorption--alkaline phosphatase (AP), bone alkaline phosphatase (bAP), osteocalcin (OC), undercarboxylated osteocalcin (ucOC), procollagen type I carboxyterminal propeptide (PICP), pyridinoline (PYD), deoxypyridinoline (DPD), N-terminal cross-linked telopeptide of type I collagen (NTx) and bone sialo protein (BSP)--were analysed in all women on days 1 and 42. Vitamin K was significantly lower in the OSP group versus nOSP and CTRL. The odds ratio results revealed the following: vitamin K, 16.7; PYD, 7.5; NTx, 6.0; DPD, 2.7; and ucOC, 2.7. Vitamin K represented a sensitivity rate of 64% and a specificity rate of 82%. In the receiver operating curve analysis, vitamin K reached the highest area under curve (AUC) score. The combination of vitamin K and AP, bAP and PYD resulted in increased AUC scores (>0.9). The parameter combination of vitamin K/PYD and vitamin K/bAP demonstrated a sensitivity rate of 75-88%, with a specificity rate of more than 82%. The data suggests that a combination of vitamin K with other biochemical bone indices might be a useful tool for assessing bone metabolism, especially in metabolic bone diseases such as osteoporosis.

Adult↗
PubMedDate not supplied

Determination of cocaine and benzoylecgonine by derivatization with iodomethane-D3 or PFPA/HFIP in human blood and urine using GC/MS (EI or PCI mode).

A method for the simultaneous detection and quantification of cocaine and benzoylecgonine from human blood and urine has been developed. Cocaine and benzoylecgonine were extracted from blood and urine with solid-phase columns containing C18 packing material. Clean, emulsion-free extracts were obtained. The analytes were derivatized with PFPA/HFIP or iodomethane-D3. The underivatized cocaine and derivatized benzoylecgonine were determined by GC/MS with positive chemical ionization (PCI) and the selected ion monitoring mode. Benzoylecgonine was derivatized with iodomethane-D3 to cocaine-D3. Both derivatives were chromatographed on a CP-SIL 5 capillary column. The recovery of extraction was greater than 70%. The detection limit for the PFPA/HFIP derivatives (20 ng/mL) was better than that for iodomethane-D3 derivatives (40 ng/mL). The procedure is simple, rapid, and reproducible. Standard curves were linear and the procedure was suitable for routine analysis. Using fluorescence polarization immunoassay (TDx, Abbott) (cutoff 100 ng/mL), along with one of the GC/MS methods described, we found no false positive or false negative results.

1-Propanol↗
PubMedDate not supplied

Effect of aprotinin on postoperative blood loss in off-pump coronary artery bypass surgery.

BACKGROUND AND AIM OF THE STUDY: Off-pump coronary artery bypass (OPCAB) enables a reduction in postoperative complications, particularly bleeding and transfusion. Nevertheless, a significant percentage of patients still needs transfusion. The effect of antifibrinolytic therapy on postoperative bleeding as part of OPCAB is still not widely described. The purpose of this study was to investigate the potential benefit of aprotinin in OPCAB. METHODS: We conducted a retrospective comparative study with a historical control group. Consecutive patients undergoing off-pump coronary bypass were divided in two groups: 40 patients were operated without any antifibinolytic drug (group C); 40 patients received aprotinin (group A) during surgery. Patients in group A received a bolus of 2 x 10(6) KIU during 30 minutes, followed by a continuous infusion of 0.5 x 10(6) KIU per hour until the end of surgery. The same protocol was used during the whole study period. RESULTS: Preoperative data of the two groups did not differ except for the number of grafts performed, which was higher in group A. Prothrombin time and activated clotting time increased in both groups after surgery. The use of packed red blood cells or fresh frozen plasma was not significantly different between both groups. Postoperative blood loss was significantly reduced in the aprotinin group (540 mL +/- 320 vs. 770 mL +/- 390, p = 0.006). No increase in postoperative troponin values was found in group A. CONCLUSIONS: Aprotinin significantly reduced postoperative blood loss without reducing the transfusion rate. Aprotinin was not associated with any increase in postoperative complications.

Aged↗
PubMedDate not supplied

IgE-mediated reactions to autoantigens in allergic diseases.

BACKGROUND: There is increasing evidence that IgE-mediated reactivity against autoantigens could play a role in the pathology of severe chronic atopic diseases. METHODS: Human mitochondrial managenese superoxide dismutase (MnSOD), acidic ribosomal P2 protein and cyclophilins were cloned by PCR, expressed as inclusion body proteins in Escherichia coli, purified by Ni2+-chelate affinity chromatography, refolded in vitro and used for further experiments. RESULTS: Human MnSOD, P2 ribosomal protein and cyclophilins respectively, show sequence identity and similarity of >50% and 70% to the corresponding allergens of Aspergillus fumigatus. The human proteins were able to bind IgE from sera of individuals sensitized to the mould proteins and to elicit strong skin reactions of the immediate type in these individuals. CONCLUSIONS: These observations provide evidence for autoreactivity to human proteins in allergic persons chronically sensitized to environmental allergens from A. fumigatus which share a high degree of sequence homology to the corresponding human proteins.

Allergens↗
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Survey of the taxonomic and tissue distribution of microsomal binding sites for the non-host selective fungal phytotoxin, fusicoccin.

The recent identification of the fusicoccin-binding protein (FCBP) in plasma membranes from monocotyledonous and dicotyledonous angiosperms has opened the basis for an elucidation of the toxin's mechanism(s) of action and indicated a widespread occurrence of the FCBP in plants. Results of a detailed taxonomic survey of fusicoccin-binding sites are reported. Binding sites were not found in prokaryotes, animal tissues, fungi and algae including the most direct extant ancestors of the land plants (Coleochaete). From the Psilotales (Psilophytatae) to the monocotyledonous angiosperms, all taxa analyzed possessed high-affinity microsomal fusicoccin-binding sites. A heterogeneous picture emerged for the Bryophyta. Anthoceros crispulus (Anthocerotae), the only hornwort available to study, lacked fusicoccin binding. Within the Hepaticae as well as the Musci, species lacking and species exhibiting toxin binding were found. The binding site thus seems to have emerged very early in the evolution of the land plants. The tissue distribution of fusicoccin-binding sites was studied in Vicia faba L. shoots. All tissues analyzed showed fusicoccin binding, although not to the same extent. On a per-cell basis, guard cells were found to contain, compared to mesophyll cells, a nine-fold higher number of binding sites. Based on cell surface area, the site density is by a factor of 32 higher in guard cells than in mesophyll cells. Tissue specific expression of the binding sites is suggested by these findings.

Animals↗
PubMedDate not supplied

Immediate alterations in the impulse noise exposed organ of Corti of the guinea pig.

Cochlear microphonics and morphological changes in the organ of Corti were examined in guinea pigs exposed to 1 or 10 impulses of 164 dB SPL. Immediately after noise exposure the CM amplitudes of frequencies between 500 and 10000 Hz delcined severly with an accelerating tendency during the next 2 hours. The decrease in CM in two groups differed insignificantly. 10 minutes after impulse exposure, whole-mount specimens showed mainly swollen and translocated nuclei of outer hair cells. After 2 hours we found large quantities of pyknotic nuclei, karyorrhexis, and gaps in the normal OHC pattern. Despite minor numerical differences in injured cells of either group, exposure to 10 impulses caused a greater degree of irreversible alteration. Altogether, altered hair cells were only localized in the basal and lower second turn, and their numbers were relatively small. This stands in contrast to severe decrease of CM from low to high frequencies. Hair cell injury and additional mechanical lesion of the reticular membrane caused many sites of leakage, allowing interchange of endo-and peri-lymph. This effect is considered to be the main cause of functional damage indicated by rapid CM decline.

Animals↗
PubMedDate not supplied

Constitutive secretion of hematopoietic cytokines by human carcinoma cell lines and its up-regulation by interleukin-1 and phorbol ester.

We investigated secretion of hematopoietic growth factors in ten human tumor cell lines, derived from 5 different tissue types. The cell lines were stimulated transiently with interleukin-1 (IL-1 ), IL-6, interferon-ç (IFN-ç), lipopolysaccharide (LPS) and tetradecanoyl phorbol 13-acetate (TPA), respectively. Conditioned media (CM) were screened in a bioassay using an indicator cell line which is growth factor-dependent and needs the supply of at least one hematopoietic cytokine. The CM of almost all tumor cell lines analyzed induced proliferation of this indicator cell line as documented by incorporation of [3H]-thymidine. The majority of constitutively cytokine-producing tumor cell lines could be induced to further increase their amounts of secreted proliferation-inducing activity. The strongest inducers were TPA and IL-1 ; weakly or not effective at all were IFN-ç, LPS and IL-6. Enzyme-linked immunosorbent assay (ELISA) identified several cytokines and macrophage-colony-stimulating factor (M-CSF) and IL-6 were secreted at the highest concentrations. Especially in kidney cell lines, the levels of granulocyte-macrophage-CSF (GM-CSF), M-CSF and IL-6 were further strongly increased by the TPA and IL-1 pretreatment. The by far highest amounts of granulocyte-CSF (G-CSF) were elaborated by the bladder cell line T-24 and could be further more than doubled by TPA. Other cell lines, derived from esophagus, lung and pancreas, responded less strongly to the pretreatment with the biomodulators. Our results demonstrating secretion of functionally active cytokines by human solid tumor cell lines suggest that these, to date so-called, hematopoietic cytokines are not entirely hematopoietic specific and might play a fundamentally important role in tumor cell biology.

Cell Division↗
PubMedDate not supplied

Spectral analysis of viscoelasticity of the human lens.

PURPOSE: In the aging lens, two different structural changes become progressively apparent: loss of accommodation and formation of cataract. These changes are due to different alterations in lens structure taking place on a molecular scale. METHODS: For the characterization of liquids, gels, elastic bodies and solids, dynamic mechanical analysis (DMA) represents a non-destructive macroscopic analysis method with considerable sensitivity to microscopic structural changes. Spectra of the shear compliance (reciprocal shear modulus) of human lenses at different ages were measured in a wide frequency range (1 mHz to 1 kHz). By means of computer analysis, the parameters of the involved relaxation processes and the viscous flow were determined. RESULTS: The increase in cross-linking density was correlated with the disappearance of viscous flow in the measured spectra. The accumulation of high-molecular-weight aggregates was held responsible for the shift of the lower frequency relaxation process to lower frequencies with increasing stiffness, which is likely to be correlated with a prolonged accommodation time. CONCLUSION: Dynamic mechanical analysis represents a useful method for the spectroscopic characterization and quantification of the changes in the macroscopic viscoelastic properties caused by molecular changes in cataract formation and loss of accommodation.

Aged↗
PubMedDate not supplied

Structure activity relationships of antiproliferative rocaglamide derivatives from Aglaia species (Meliaceae).

Eleven rocaglamide derivatives (cyclopentatetrahydrobenzofurans) and one structurally related aglain congener all isolated from different Aglaia species (Meliaceae) were tested for growth inhibiting properties using the human cancer cell lines MONO-MAC-6 and MEL-JUSO. Proliferation of both cell lines was efficiently inhibited in a dose and compound dependent manner. Applying MTT-Assay, the IC50 of the most active compound didesmethyl-rocaglamide (1) was observed at 0.002 and 0.006 micrograms/ml (0.004 and 0.013 microM) depending on the cell line investigated. Bulky aminoacyl substituents at C-2, acetylation of the OH substituent at C-1 or insertion of a OH or OMe substituent at C-3 of the rocaglamide skeleton all diminished the activity of the compounds investigated. The aglain derivative 12 was inactive up to a concentration of 3 micrograms/ml (4.6 microM). This loss of activity is assumed to be mainly due to the presence of a pyran ring in the aglains vs. a furan ring as found in rocaglamide derivatives. Rocaglamide derivatives may act primarily by inhibition of cell proliferation as evidenced by the absence of a significant cytotoxic effect in long-term cultures of MONO-MAC-6 cells treated with high doses of didesmethylrocaglamide. Our data suggest that rocaglamide derivatives could exert a potential role in the treatment of malignant diseases and are worth to be investigated in further studies of experimental medicine and pharmacology.

Antineoplastic Agents, Phytogenic↗