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Biomedical subjects

M Hartmann

Publications and source records attributed to M Hartmann.

At least 397 records · Page 22Linked to original sources
PubMed1980

In vivo and in vitro recombination of lambda DNA in CaC12 transfection.

Using CaCl2 mediated transfection with Lambda DNA fragments, in vitro joining by ligase and in vivo recombination with helper phage DNA are effective systems for generating artificial recombinants. Recombination efficiencies are 20--30% in the in vitro and in vivo recombination systems. At 30 to 37 degree C T4 ligase mainly joins natural cohesive alpha ends, while at 12 degrees C the EcoRI-generated termini are preferentially ligated to form biologically active molecules, if the cloning vector alpha 401 is used, which has only one EcoRI target. The ligation products were characterized by gel electrophoresis and CaCl2 transfection. For in vivo recombination a new CaCl2 transfection system was developed, termed postinfection-dependent CaCl2 transfection system, which is based on the infection of recipient cells with helper phages after transfection. In marker rescue experiments using this method not only single but also double recombination occurred between two independent alpha DNA fragments and the helper phage DNA.

Bacteriophage lambda↗
PubMed1980

[Local sudomotor attacks in the left ulnar nerve area (author's transl)].

Two patients with circumscribed sudomotor and vasomotor attacks in the area of the ulnar nerve of the left hand are described. The onset of the disease in both cases occurred at approximately 10 years of age. Etiology is discussed in terms of an excessive and erroneous visceral-efferent regeneration after unknown trauma of the ulnar nerve during childhood.

Adult↗
PubMed1980

[Pharmacokinetics of caffeine in mice and its modification by ethanol].

In experiments on mice the pharmacokinetics (absorption, distribution, metabolism) of orally administered caffeine (18 mg/kg) using 14C caffeine as marker and the influence of simultaneously applied ethanol (1,8 g/kg) was tested. The following results were obtained: 1. Caffeine was very quickly absorbed from the gastro-intestinal tract of mice. Addition of ethanol had no noticeable influence on the absorption of caffeine. 2. The elimination of caffeine from the serum and tissues examined (liver, kidney, brain, muscle) showed an exponential course with a half life of 40-60 minutes and was completed after 4 to 5 hours. 3. By giving ethanol the elimination of caffeine was significantly decreased and its half life increased to 160-240 minutes. 4. The caffeine metabolites reached their maximal concentration in serum and tissues examined within two hours. In the liver and kidney the concentration of caffeine metabolites was greater than in the serum, whereas they were lower in the brain and muscle. At the end of the experimental the concentration of caffeine metabolites reached only very low values. 5. After administration of ethanol the caffeine metabolites were significantly decreased from the 30th to 180th minute in the liver and kidney; they were only slightly lowered in the serum and almost unchanged in the muscle and brain. The results of these experiments suggest that ethanol inhibits the metabolism of caffeine in the liver, especially by influencing its demethylation to other dimethyl- and monomethylxanthines and probably also its oxidation ot methyluric acids.

Absorption↗
PubMed1979

Molecular characterization of the genomes of actinophages SH3, SH10, SH11, and SH12 infecting Streptomyces hygroscopicus.

Some physico-chemical properties of the DNAs released from the actinophages SH3, SH10, SH11, and SH12 are described. The four phage DNAs have a linear double-stranded secondary structure and are unique with respect to their high G.C contents which, from melting studies and buoyant density experiments, were found to be in the range of 68-73 mol-%. The DNA molecular weights were determined by sedimentation velocity experiments and by electron microscopic length measurements, the mean values of the two corresponding data sets being 34.0 x 10(6) (SH3), 26.7 x 10(6) (SH10), 26.1 x 10(6) (SH11), and 28.7 x 10(6) (SH12) with a mean relative error of +/- 5%. From different observations it was concluded that SH10 DNA, and possibly also SH11 and SH12 DNA, have cohesive ends and can undergo intramolecular or intermolecular association to form ring-like monomers or linear and ring-like multimers. Cleavage of the DNAs of SH3, SH10, SH11, and SH12 by EcoRI restriction endonuclease delivered two, one, zero, and two cleavage sites, respectively, and by BamHI restriction endonuclease eight, zero, zero, and zero cleavage sites, respectively.

Bacteriophages↗
PubMed1978

The immediate effects of intravenous specific nutrients on EEG sleep.

This study examined the immediate influence of intravenous amino acids and glucose on sleep as measured by all-night EEG recording. The study on 9 normal female subjects was of a latin-square design. Slow wave sleep (SWS) was increased by both solutions whilst dream sleep (REM) was decreased by amino acids and increased by glucose. Total sleep time was not affected. Subjective feelings as to restlessness, quality and depth of sleep under the impact of the various solutions were gathered. The work further elucidates the effect of nutrition on sleep and supports certain theories as to the function of the main sleep component.

Adult↗
PubMed1978

Relative genealogic incidence of certain "civilization diseases" in a geriatric population versus pregeriatric groups.

In a prevalence epidemiologic study conducted in a characteristic submontane area in North Bohemia, the genealogic incidence of myocardial infarction, sudden brain vascular episodes, and malignant tumors was studied in a representative sample of persons aged 70 to 105 years. The incidence was then compared with that in two other samples: 1) men under age 40 with a history of transmural myocardial infarction, and 2) both men and women aged 40--60 who had a stroke. The statistical evaluation was performed according to accepted international criteria (WHO). A significantly lower genealogic incidence of myocardial infarction and sudden brain vascular episodes was found in the geriatric subjects (70--105 years old) who had symptoms of so-called physiologic aging, as compared with the incidence in the younger subjects who had symptoms of so-called pathologic aging. The difference was less clear-cut with respect to the genealogic incidence of malignant tumors.

Adult↗
PubMed1978

[Surgical treatment of hyperhidrosis axillaris].

Radical sweat gland excision is the treatment of choice in axillary hyperhidrosis. After a review of the common surgical techniques the own technique is discribed. It consists of a vertical excision of the hyperhidrotic skin area and primary wound closure. No recurrences of hyperhidrosis were seen in the follow up period.

Adult↗
PubMed1977

Some risk factors in pathologic aging.

A clinico-epidemiologic prevalence survey was conducted in the sub-mountainous area of Northern Bohemia, which is distinguished by the highest proportion of aged people in Bohemian countries. It involved 6057 persons of the 70-79 age group, 1718 persons of the 80-89 age group and 139 persons of the 90+ group, plus control subjects in various other groups. In this study an attempt was made to find an effective measure of the presumed risk factors of pathologic aging in persons of the 70-105 age group. The data were analyzed by the method of coincidence of two parameters of binomial decomposition on the computer Odra. The quantity dependence of the signs was determined, and an index of the compound-risk factor of pathologic aging was calculated. When the numerical value of the index is lower than 56.9 +/- 4.36 for a group of males or 50.3 +/- 3.55 for a group of females, the probability is that a given person in those groups will survive to an advanced age. The total risk is higher for the male sex. Of considerable importance are the genetic burden, external environmental causes, harmful habits, certain "civilization" diseases, and other factors such as disturbed social contacts and defective nutrition.

Aged↗