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Biomedical subjects

A Schmidt

Publications and source records attributed to A Schmidt.

At least 577 records · Page 32Linked to original sources
PubMed1986

The impact of a drug information sheet on the understanding and attitude of patients about drugs.

A proposed Food and Drug Administration program to require written information with prescription drugs could cost $500 million annually; the American Medical Association has implemented a similar, voluntary program costing more than $3 million. However, the educational impact of written drug information has not been studied. We evaluated one-page drug information sheets using an objective examination. The baseline score of 71 patients was 3.9 of 6.0. Patients tested before and one day after receiving the drug sheet improved their score by +1.4. In the second phase, patients randomized to receive the drug sheet improved their score after one month by +1.1; those not given the sheet had no improvement. Changes in attitudes and incidence of reported adverse effects seemed to be random and unrelated to the information sheet. Thus, a drug information sheet may be a useful adjunct to patient education.

Attitude↗
PubMed1986

Role of lysines in ion selectivity of bacterial outer membrane porins.

The epsilon-amino groups of available lysine residues of the OmpC, OmpF and PhoE porin proteins of Escherichia coli and of the protein P porin of Pseudomonas aeruginosa, were modified by the bulky reagent trinitrobenzenesulphonic acid. Approximately 78% of the lysines of the anion-selective protein P and PhoE porins were modified whereas only 40-50% of the lysines of the cation selective OmpF and OmpC porins were altered. After modification, the three E. coli porins had very similar high selectivities for cations over anions, in contrast to the native porins which varied 86-fold in ion selectivity. Despite the large size of the trinitrophenyl group attached to modified lysines (i.e., a disc of approx. 0.86 nm diameter X 0.36 nm high) relative to the reported size of the constrictions of the E. coli porins (1.0-1.2 nm diameter), only the anion-selective PhoE porin was substantially blocked after trinitrophenylation. The protein P porin channel was relatively unaffected by trinitrophenylation, in contrast to previous data showing dramatic effects of acetylation of lysines on protein P conductance and selectivity. This favoured a model in which the critical lysines involved in anion binding by protein P were present in a constriction of the channel that was too small for trinitrobenzenesulphonic acid to enter. Overall, the data suggest that both the number and relative position of charged lysines are major determinants of ion selectivity.

Anions↗
PubMed1986

A wheat germ cap-site factor functional in protein chain initiation.

Component C1 from wheat germ, a factor that functions in attaching ribosomes to mRNA, has been resolved into a fraction that does not bind to m7GDP-agarose (referred to as eIF4B) and one that binds and is eluted specifically by m7GDP. Both components are required for the attachment of ribosomes to [3H]methyl-labeled reovirus RNA and for the translation of a number of mRNAs, including the noncapped RNA of satellite tobacco necrosis virus. The component that binds to m7GDP-agarose, referred to as CSF (cap-site factor), contains primarily proteins of Mr 24,000, 26,000, and 75,000. Crosslinking studies with oxidized [3H]methyl-labeled reovirus RNA show that one of the lower molecular weight polypeptides of CSF interacts specifically with the 5'-cap of the mRNA in the absence of any other components. Incubation of component C1 and eIF4A in the presence of ATP results in the additional crosslinking of a 51- and a 65-kDa protein. In the absence of eIF4A, there is only the crosslinking of the lower molecular mass polypeptide (24 or 26 kDa). Attempts to reconstitute the C1 reaction with CSF and eIF4B result in a considerably diminished reaction. Crosslinking of eIF4A, however, is obtained in an incubation containing only CSF and eIF4A, suggesting that CSF may bring about an initial interaction of eIF4A with the 5' end of the mRNA.

Adenosine Triphosphate↗
PubMed1986

The nucleotide sequence of the mercuric resistance operons of plasmid R100 and transposon Tn501: further evidence for mer genes which enhance the activity of the mercuric ion detoxification system.

The DNA sequences of the mercuric resistance determinants of plasmid R100 and transposon Tn501 distal to the gene (merA) coding for mercuric reductase have been determined. These 1.4 kilobase (kb) regions show 79% identity in their nucleotide sequence, and in both sequences two common potential coding sequences have been identified. In R100, the end of the homologous sequence is disrupted by an 11.2 kb segment of DNA which encodes the sulfonamide and streptomycin resistance determinants of Tn21. This insert contains terminal inverted repeat sequences and is flanked by a 5 base pair (bp) direct repeat. The first of the common potential coding sequences is likely to be that of the merD gene. Induction experiments and mercury volatilization studies demonstrate an enhancing but non-essential role for these merA-distal coding sequences in mercury resistance and volatilization. The potential coding sequences have predicted codon usages similar to those found in other Tn501 and R100 mer genes.

Amino Acid Sequence↗
PubMed1986

[Surgical treatment of bile duct cysts in childhood].

Nine cases of cystic and cylindric bile duct dilatation are discussed. They were treated at the Children's Surgical Hospital of the University of Munich from 1970 to 1984. The patients' mean age was 4.2 years. Upper abdominal sonography in combination with hepatobiliary functional scintigraphy or computer tomography has been proven the best diagnostic procedure. The operating procedure of choice is a total cyst excision followed by an end-to-end anastomosis or a hepatojejunostomy according to the Roux-Y-technique. There were no immediate postoperative complications such as cholangitis. In one case we found a stenosis of the anastomosis after primary hepatocholedochostomy.

Child↗
PubMed1986

Use of the erythrocyte sedimentation rate in chronically ill, elderly patients with a decline in health status.

A decline in health status in a chronically ill, elderly patient could mean the progression of a known disease, depression, or the development of a new disease. The value of the erythrocyte sedimentation rate in selecting patients in whom the likelihood of a new disease is high enough to warrant a diagnostic evaluation was studied. Subjects included long-term residents of a chronic-care hospital over age 65 in whom the erythrocyte sedimentation rate was determined because of a nonspecific, subacute change in health status (n = 98) or new, unexplained musculoskeletal complaints (n = 44). The target erythrocyte sedimentation rate-elevating diseases included infections, connective tissue diseases, and malignancies. Among the group with subacute deterioration, post-test probabilities (incorporating clinical data with test results) of a new disease ranged from 7 percent in those with an erythrocyte sedimentation rate below 20 mm per hour to 66 percent in those with a rate of 50 mm per hour or more. The comparable probabilities among the group with musculoskeletal complaints were 3 percent and 57 percent. The erythrocyte sedimentation rate, an inexpensive test, although nonspecific, appears useful in deciding when to pursue expensive, and sometimes uncomfortable or hazardous, diagnostic evaluations. The erythrocyte sedimentation rate is most useful among patients in whom the probability of disease is moderate (neither very high nor very low) following initial history-taking and examination.

Aged↗
PubMed1986

Increased activity of chondroitin sulfate-synthesizing enzymes during proliferation of arterial smooth muscle cells.

Cultured arterial smooth muscle cells incorporate [35S]sulfate into the extracellular chondroitin sulfate/dermatan sulfate containing proteoglycans at a higher rate in the phase of logarithmic growth than do non-dividing cells. The cell growth-dependent decrease in 35S incorporation with increasing cell density is accompanied by a decrease in the activity of chondroitin sulfate-synthesizing enzymes. The specific activity of xylosyl transferase, N-acetylgalactosaminyl transferase I and chondroitin sulfotransferase declines as the cells proceed from low to high densities. The corresponding correlation coefficients are 0.86, 0.91 and 0.89. The ratio of C-6OH/C-4OH sulfation of chondroitin shows a cell proliferation-dependent decrease indicating an inverse correlation of chondroitin 6-sulfotransferase and chondroitin 4-sulfotransferase activity. The observed changes in the expression of enzyme activities are thought to have some implications in the pathogenesis of arteriosclerosis, the initial stages of which are characterized by proliferation of arterial smooth muscle cells.

Animals↗
PubMed1986

Developmental and tissue-specific expression directed by the alpha 2 type I collagen promoter in transgenic mice.

Eight transgenic mice were generated in which the promoter of the mouse alpha 2(I) collagen gene (nucleotides -2000 to +54), linked to the bacterial gene for chloramphenicol acetyltransferase (CAT), is stably integrated in the germ line. These strains contain from 1 to 20 copies of the alpha 2(I) collagen-CAT chimeric gene per haploid genome. In seven of the eight strains, the CAT gene is expressed, although the levels of CAT enzyme activity vary considerably from one strain to the other. In six of these strains, the expression of the CAT gene follows the expected tissue distribution pattern of expression of the alpha 2(I) collagen gene. In these six strains, the level of CAT activity is much higher in extracts of tail, a tissue that is very rich in tendons, than in any other tissue that was tested. This distribution parallels the much higher levels of alpha 2(I) collagen RNA that are found in the tail as compared to other tissues. Expression of the chimeric gene is detected in the embryo after 8.5 days of gestation, at approximately the same time that the endogenous type I genes become active. We conclude that the alpha 2(I) collagen promoter sequences present in the recombinant plasmid used for our experiments contain sufficient information to ensure stage- and tissue-specific activity of this promoter.

Acetyltransferases↗
PubMed1986

Effect of SO(2) and O(3) on Production of Antioxidants in Conifers.

Production of antioxidants was investigated in needles of fir (Abies alba Mill.) and spruce (Picea abies (L.) Karst) after exposure to low concentrations of SO(2), O(3), and a combination of both pollutants. Glutathione reacted most sensitively to pollutants followed by vitamin E and vitamin C. In spruce needles, the overall increase of antioxidants after exposure to air pollutants was lower than in needles of fir. SO(2) was more potent than O(3). Maximum increase of antioxidants was found in needles after exposure of trees to SO(2) + O(3).

Journal Article↗
PubMed1986

Lipid peroxidation in higher plants : the role of glutathione reductase.

To study the role of glutathione reductase in lipid peroxidation, bean leaves (Phaseolus vulgaris) cv Fori were treated with the herbicide acifluorfen-sodium (sodium 5-[2-chloro-4-(trifluoromethyl)phenoxy]-2-nitrobenzoic acid). Acifluorfen is a potent inducer of lipid peroxidation. In beans, decrease of acid-soluble SH-compounds and lipid peroxidation, measured as ethane evolution, were the toxic events after treatment of leaves with acifluorfen. As a primary response to peroxidation, increased production of antioxidants, such as vitamin C and glutathione, was found. This was followed by elevation of glutathione reductase activity. Enhanced activity of the enzyme prevented both further decline of acid-soluble SH-compounds and lipid peroxidation. Increased production of antioxidants and elevated activity of antioxidative enzymes, like glutathione reductase, seem to be a general strategy to limit toxic peroxidation in plants.

Journal Article↗
PubMed1986

Dermatoglyphic peculiarities in families with X-linked mental retardation and fragile site Xq27: a collaborative study.

The dermatoglyphic patterns of fingertips, palms and soles of 75 male patients with X-linked mental retardation and fra-Xq27 and of 28 obligate female heterozygotes were analyzed and compared with the data from 200 male and 200 female control individuals. The results show that there is a strong association between the fra-X-syndrome and dermatoglyphic peculiarities observed in male patients and also in female heterozygotes. The characteristic dermatoglyphic features of the fra-X-syndrome are: increased frequencies of radial loops, whorls and arches on the fingertips, a pronounced transversal course of palmar ridges, lower a-b RC, absence of c-triradii on the palms, abnormal palmar and plantar creases, dysplasia of the papillary ridges and low frequencies of true patterns on the soles. Some of these patterns were found in the female carriers of fra-Xq27 also. The combination of palmar and plantar patterns, expressed by a "log. score-Index", provides a high degree of discrimination between the male patients with fra-X-syndrome and the control group. A preliminary log. score-Index was developed also for the female heterozygotes. A "phantom picture" of the dermatoglyphic stigmata is constructed. We suggest that dermatoglyphic examination of the members of families suspected for fra-Xq27-syndrome can be useful for predicting this state and for diagnosing male hemizygotes and carrier females.

Adolescent↗
PubMed1986

Transcriptional control of the mouse alpha 2(I) collagen gene: functional deletion analysis of the promoter and evidence for cell-specific expression.

A chimeric gene was constructed in which sequences between 2,000 base pairs upstream of the start of transcription of the mouse alpha 2(I) collagen gene and 54 base pairs downstream of this site were fused to the chloramphenicol acetyltransferase (CAT) gene. We present evidence suggesting that this collagen gene segment is sufficient for cell-specific expression of the chimeric gene. Indeed, the levels of CAT activity in transient expression experiments were at least 10 times higher after transfection of NIH 3T3 cells than after transfection of a mouse myeloma cell line, whereas much less difference was found after transfection of these two cell types with pSV2-CAT, a plasmid in which the early simian virus 40 promoter is fused to the CAT gene. Several deletions were introduced in the same 5'-flanking segment of the alpha 2(I) collagen gene, and the effects of these deletions were examined after DNA transfection of the chimeric collagen-CAT gene into NIH 3T3 cells. At least two segments broadly located between -979 and -502 and between -346 and -104 are needed for optimal expression of the chimeric gene. These results were obtained both in transient expression experiments and by analysis of pools of NIH 3T3 cells that were stably transfected with the different mutants. In general, the effects of the deletions on the activity of the alpha 2(I) collagen promoter were analogous, whether the plasmids harbored the simian virus 40 enhancer sequence or not, although the overall levels of expression of the chimeric gene were increased when the recombinant plasmids contained this sequence.

Animals↗
PubMed1986

Compartmentation and characterization of different proteoglycans in bovine arterial wall.

Proteoglycans stained specifically with cuprolinic blue have been visualized in electron micrographs of bovine arterial tissue. Three differently sized proteoglycan-cuprolinic blue precipitates, designated as types I, II, and III, could be detected in the extracellular matrix. The precipitates could be distinguished by their length, width, area, topographical distribution, and their characteristic association with other matrix components. By taking into account the available biochemical data and the individual susceptibilities of the precipitates towards specific glycosaminoglycan-degrading enzymes, each type of proteoglycan-cuprolinic blue precipitate could be attributed to a proteoglycan population containing dermatan sulfate, chondroitin sulfate, or heparan sulfate as its main glycosaminoglycan component.

Animals↗
PubMed1986

Pulmonary function and acid application in the esophagus.

The effect of acid application in the esophagus on pulmonary function was measured in three groups of patients in a double-blind investigation. Group 1 consisted of ten patients with esophagitis but without pulmonary disease, group 2 was 21 patients with bronchial asthma without esophagitis, and group 3 was eight patients with both esophagitis and bronchial asthma. Pulmonary function was assessed by total lung capacity (TLC), airway resistance (Raw), residual volume (RV), and peak expiratory flow (PEF). The four parameters were measured at the following five times during a single trial: before and after insertion of an esophageal catheter; after instillation of 50 ml of isotonic sodium chloride solution; after instillation of 50 ml of 0.1 N hydrochloric acid; and after intravenous injection of atropine (0.01 mg/kg of body weight). A significant decrease (the Wilcoxon test, p less than 0.02; and the Mann-Whitney test, p less than 0.002) in PEF and a significant increase (p less than 0.02 and p less than 0.002, respectively) in Raw after instillation of HCl were seen only in group 3. Changes in the other groups were small and without any regular pattern. Six of the patients in the third group accepted another trial after three days of pretreatment with atropine (0.01 mg/kg twice daily). Now instillation of acid did not produce any change in PEF or Raw (p less than 0.001). We conclude that a modest bronchoconstriction when acid is present in the esophagus is seen in patients with bronchial asthma and severe esophagitis. Atropine inhibits this bronchoconstriction, indicating vagal mediation.

Adult↗
PubMed1986

Water loss from the respiratory tract during hyperventilation in normal subjects and in asthmatics.

Expiratory water loss was measured in four asthmatics and in four healthy subjects by leading the expired air through a tube filled with silicagel during hyperventilation. No difference in water loss was seen as the average water loss was 0.025 g/l for the asthmatics and 0.029 g/l for the healthy subjects. After hyperventilation PEF decreased more than 20% in the asthmatics while no change was seen in the lung function of the healthy subjects. It is concluded that expiratory water loss per se is not the reason for the decrease in lung function seen in asthmatics after exercise and hyperventilation.

Adult↗
PubMed1986

Reproducibility of histamine inhalation in asthmatics.

The reproducibility of the changes in FEV, induced by inhalation of histamine, was studied in adult asthmatics. Histamine was inhaled from a Hudson nebulizer, delivering 0.3 ml/min, at tidal breathing through one minute. FEV was measured immediately before and two minutes after cessation of the inhalation. Identical concentrations of histamine were inhaled by the individual patient on every challenge. Reproducibility was studied on the same day, with one day inbetween the histamine challenges and with 12 weeks inbetween two challenges. When reproducibility during the same day was studied an average fall in FEV of 34% was found after the first inhalation and 34% decrease was found after the second challenge. When histamine challenge were done on two following days the fall in FEV was 25% on the first day and 28% on the second day. The average fall in FEV was 34% and 28% when reproducibility was studied with an interval of 12 weeks. No statistically significant difference was found between any of the compared challenges.

Adult↗