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Biomedical subjects

H Fritzsche

Publications and source records attributed to H Fritzsche.

At least 73 records · Page 4Linked to original sources
PubMed1988

The influence of mixed venous pO2 on the natriuretic activity of cat plasma.

Plasma was taken from anaesthetised cats with high or low mixed venous pO2. Different plasma fractions were then administered to anaesthetised rats to examine the effect on sodium excretion. It was found that only the low molecular weight fraction of the plasma from cast with high mixed venous pO2 showed any natriuretic activity. A lipid soluble extract from the same plasma also increased sodium excretion. It is concluded that an increase in mixed venous pO2 in anaesthetised cats leads to the release or activation of a natriuretic factor, which has a molecular weight below 700 and is lipid soluble.

Animals↗
PubMed1987

Anthracycline antibiotics. Interaction with DNA and nucleosomes and inhibition of DNA synthesis.

We report studies of the interaction of four anthracycline antibiotics, iremycin (IM), daunomycin (DM), aclacinomycin A (AM), and violamycin B1 (VM), with naked DNA, nucleosomal core particles, and 175 base pair (bp) nucleosomes lacking histone H1. In all cases the binding strength increases in the order IM less than DM approximately AM less than VM. The binding substrates increased in affinity for the drugs in the following order: core particles less than 175-bp nucleosomes less than DNA. The apparent DNA length increment per drug bound decreases in the progression IM greater than DM greater than AM greater than VM, the same serial order as is characterized by increasing binding affinity. Dichroism amplitude measurements show that for all drugs the long-wavelength absorbance transition moment is tilted by 26-29 degrees relative to the plane perpendicular to the helix axis; this angle probably corresponds to the long axis tilt of the intercalated chromophore. Finally, it was found that the ability of the drugs to inhibit DNA synthesis by Escherichia coli DNA polymerase I increases in the same order as their binding affinity.

Aclarubicin↗
PubMed1987

[Diagnosis and therapy of Basedow hyperthyroidism. Results of an Austrian study].

After organisation and presentation of an European survey about "The management of Hyperthyroidism due to Graves disease" by the European Thyroid Association (ETA) national studies have been proposed. The Austrian survey was realized by the Austrian Society of Nuclear Medicine (ONG). Based on the original questionnaire of the ETA with a simple case report of uncomplicated Graves' disease and with 8 variations of the basic case including sex, age, thyroid volume and recurrence participants were asked to comment diagnostic and therapeutic procedures. Out of 42 participants 19 were heads of departments, 19 assistants and 4 internal specialists in practice with main clinical work in the field of thyroid diseases. Thyroid scintigraphy is performed in 98% (Tc 99 m 78%, J 123 15%) and ultrasound in 64%. "In vitro"-procedures include 5-6 tests (means = 5,7). 21% prefer determination of total hormones, 31% of free hormones. Various combinations of both hormone determinations are used most frequently. TRH-Test ist performed in 52.4%. Auto-antibodies are measured in 81%. TSH-receptor auto-antibodies and microsomal and thyreoglobulin auto-antibodies as well are determined in 40%. Therapeutic options of the basal case report and the 8 variations showed antithyroid drugs (ATD) in 62%, radioiodine (RI) in 26% and surgery in 12%. RI is proposed in elder patients (79%) and in patients with recurrence of the disease (45%). Surgery is recommended in patients with large thyroid volume (57%). For ATD administration only carbimazole and methimazol in a mean dosage of 60 mg/die (range 20-120 mg/die) is chosen. After euthyroidism is reached ATD is reduced to 50-90% of the original dosage.(ABSTRACT TRUNCATED AT 250 WORDS)

Austria↗
PubMed1986

[Diagnosis of radionuclide uptake using samples and excretion measurements].

Diagnosis of internal contamination with radionuclides can be achieved by body or organ counting and by analysis of samples of intake or excretion. Sample counting from air, drinking water, food etc. is preferred in environmental contamination and may be used to estimate average body burden and internal dose. For complete monitoring of intake numerous samples have to be measured. Unknown internal contamination with alpha and low energy beta emitters is detected by excretion analysis. For determination of body or organ burden, based on standard man models, time and frequency of intake, physical, chemical and biological behaviour of radionuclides have to be taken into account. Sample sources are mainly urine, feces, exhaled air and in special cases sweat, blood and hair. The collection of excreta needs the cooperation of the contaminated individuals. The results of analysis is usually delayed because of time consuming radiochemical procedures. Repetition of measurement is necessary to increase precision of dose estimate and for detection of single, recurrent or continuous uptake.

Accidents↗
PubMed1986

[A so-called atypical adenoma of the thyroid in an endemic struma area].

In view of the benign clinical course of the atypical adenoma and the high diagnostic accuracy of our frozen sections we feel that subtotal strumectomy with in toto removal of the adenoma and closely spaced follow-ups constitutes an adequate treatment of this thyroid neoplasm. In our opinion primary lobectomy means unnecessarily exposing a disproportionately high percentage of patients to the higher complication risk of this more radical surgery. From 1977 to 1982 there were 47 cases of atypical adenoma among our patients. The ratio men: women was 1:3.7, the mean age of the patients was 44 years. The patients underwent subtotal strumectomy. In the period under review "atypical adenoma" diagnosed on the basis of frozen sections turned out to be carcinoma in 5 instances. The follow-up period of the 47 patients that underwent surgery ranges from 1 1/2 to 7 years. None of the patients has had tumor regrowth so far.

Adenoma↗
PubMed1985

NMR studies on oligodeoxyribonucleotides containing the dam methylation site GATC. Comparison between d(GGATCC) and d(GGm6ATCC).

The conformation of two hexanucleotides, d(GGATCC) and d(GGm6ATCC), has been studied by proton nuclear magnetic resonance. Nuclear Overhauser effect (NOE) measurements on d(GGATCC) are in agreement with a normal B form right-handed helical structure. The single- and double-strand resonances are in fast exchange on a proton NMR time scale. The exchange is observed to be slow for d(GGm6ATCC); up to the Tm, separate resonances are observed for each state, though above the Tm exchange becomes more rapid. The preferred orientation of the adenosine methylamino group (methyl cis to N1) hinders base-pair formation. At 0 degree C irradiation of the m6A-T imino proton gives an NOE to AH2, showing that base pairing is Watson-Crick. Intra- and interresidue NOEs show that the helix is right handed and in the B form. Comparing results on the two oligomers demonstrates that adenosine methylation induces little or no change in the conformation of the helix but reduces the Tm from 45 to 32 degrees C. All of the amino proton resonances, as well as the imino resonances, have been assigned. From NOE experiments on the unmethylated oligomer we have located the Watson-Crick and non-Watson-Crick adenosine amino protons. At 0 degree C these resonances show broadening due to rotation of the amino group, and their rotation is slightly slower than for the adjacent guanosine amino group, though both these amino groups have lifetimes of less than 10 ms at 0 degree C. The imino protons show normal behavior, disappearing from the spectra ca. 20 degrees C below the Tm.(ABSTRACT TRUNCATED AT 250 WORDS)

Base Sequence↗
PubMed1985

[The supply of iodine in the province of Vorarlberg].

For evaluation of iodine supply in Vorarlberg, Austria, iodine urine excretion was measured in 299 patients. The Mean was 74,3 +/- 53,6 micrograms J/g Cr, the Median 61 micrograms J/g Cr. 79% of the patients showed an iodine deficiency I according to WHO classification and 41% an iodine deficiency II. In this patient group were included 44 subjects with no thyroid disease who showed an iodine excretion of 70.8 +/- 56,5 micrograms J/g Cr and a Median of 50,5 micrograms J/g Cr. There was no statistical difference to the values of the patient group. Regional evaluation of iodine supply showed an iodine deficiency I in 78% and an iodine deficiency II in 38% in the industrial region of the Rheintal. In the region Walgau with mixed industrial-rural population an iodine deficiency I was found in 81% and an iodine deficiency II in 45%. In the rural areas of Bregenzerwald and deep valleys an iodine deficiency I could be demonstrated in 81% and 83% respectively and an iodine deficiency II in 47 and 57% respectively. This moderate but statistically not significant differences show the minor influence of alimentation in iodine supply. Assuming a constant table salt consumption the results support the common belief that iodine supply in iodine deficient areas is strongly connected to incorporation of iodinated table salt. Therefore an increase of the iodination of table salt in Austria seems to be necessary to guarantee sufficient iodine supply.

Adolescent↗
PubMed1985

[Sonographic findings in autonomous adenoma of the thyroid gland in a goiter-endemic region].

Ultrasound scanning was carried out in 84 patients with autonomous nodules and 67 patients with inactive nodules. The echo pattern was correlated to the macro- and microscopic findings as well as to the function of the nodules. The autonomous nodules showed a low echogenicity in 57%, a normal parenchyma-identical echogenicity in 10% and a high echogenicity in 33%. In comparison the echo pattern of the inactive nodules showed low level echoes in 31%, normal in 36% and a high level echoes in 31%. Only one third of the nodules showed a homogeneous echo pattern, one third showed liquid degeneration and one third a mixed echo pattern. There is no correlation between the echo pattern of the autonomous nodules and the metabolic function of the nodules. 65 patients have been operated (37 autonomous and 28 inactive nodules). The macroscopic findings showed bleeding and cysts in most of the echo-poor nodules, also those with homogeneous structures. In the histological findings microfollicular structures were found in both high- and low-echogenicity nodules (18/16%). Macrofollicular changes and mixed forms were found mainly in nodules with parenchyma-identical and high echogenicity (58/48%). Ultrasound is very helpful in the morphological diagnosis of thyroid nodules, but there is no significant correlation to metabolic activity or to microscopic structures of the nodules in the thyroid gland.

Adenoma↗
PubMed1984

Infrared linear dichroism of oriented DNA-ligand complexes prepared with the wet-spinning method.

Oriented DNA films prepared by the wet-spinning technique have been complexed with several ligands: the anthracycline antibiotic violamycin BI, the dipeptide L-carnosine, and the oligopeptide antibiotic netropsin. The formation of the DNA-ligand complexes is accompanied by dramatic changes of the conformational flexibility of DNA. The B-A transition which occurs usually between 80% and 70% relative humidity (RH) is more or less suppressed by the ligands. Violamycin BI at a total ligand per DNA base pair ratio, rt, of approximately 0.03 and L-carnosine at rt approximately 1.5 inhibit the B-A transition of approximately 18 and approximately 0.25 base pairs per ligand molecule, respectively. Netropsin at rt = 0.2 induces a very stable B-DNA even at rather low RH (23%). The total hydration of this complex is significantly higher than for a drug-free DNA film. Netropsin-DNA complexes at rt of 0.02 and 0.01 result in an inhibition of approximately 45 base pairs per drug molecule with respect to the B-A transition.

Aminoglycosides↗
PubMed1984

[Adenomatoid tumors of the uterus].

The clinical behavior and the histogenesis of adenomatoid tumors of the uterus are discussed by means of an own case and of the relevant literature. For some time reports increase suggesting a mesothelial origin of this entity. These tumors are regarded as a variety of benign mesotheliomas. The own findings support this idea.

Adenoma↗
PubMed1983

Nuclear magnetic resonance study on the exchange behavior of the NH-N protons of a ribonucleic acid miniduplex.

The exchange behavior of the guanine N(1) and uracil N(3) protons in the self-complementary hexanucleotide r(ApApGpCpUpU) has been studied at 5 degrees C in 80% H2O/20% D2O by proton NMR. Under these conditions, the hexanucleotide forms a stable miniduplex. The exchange rate of all Watson-Crick NH protons is unaffected by addition of trifluoroethylamine up to 0.07 M. On the other hand, addition of phosphate buffer, pH 6.9, enhances the exchange rate of the uracil N(3) protons of both terminal and internal A X U base pairs but does not influence the exchange rate of the guanine N(1) protons of the central G X C base pairs. Catalysis by increased phosphate concentrations results in an open-limited rate of the internal A X U base pairs with kex = 233 s-1, equivalent to a lifetime of 4.3 ms. The proton exchange of the central G X C is regulated by the opening rate of the central core of the miniduplex. On the other hand, the sensitivity of the exchange rate of internal as well as of terminal A X U base pairs can be explained by their reduced lifetime due to end "fraying" and a subsequent catalysis of the exchange process from the opened state. These results suggest that it may be possible to probe labilized parts of RNAs such as tRNA by gradual addition of the exchange catalyst phosphate and to monitor their exchange rates by proton NMR.

Base Composition↗