PubMed Health⌕ Search

Biomedical subjects

H Fritzsche

Publications and source records attributed to H Fritzsche.

At least 19 recordsLinked to original sources
PubMed1992

The formation of A-DNA in NaDNA films is suppressed by netropsin.

Oriented films of NaDNA complexed with netropsin were studied with deuterium nuclear magnetic resonance (2H NMR), X-ray diffraction and ultraviolet (UV) linear dichroism to obtain information about the influence of netropsin on the structural arrangement of the DNA bases and on the B-A transition. The results of these studies clearly demonstrate a strong suppression of the formation of A-DNA at relative humidities (RHs) down to about 50%. The suppression was complete in the NaDNA-netropsin complex studied with 2H NMR which had a netropsin input ratio, r, of 0.22 drug/base pair. The sample used for UV linear dichroism had a similar input ratio while the X-ray diffraction samples had input ratios between 0.033 and 0.39 drug/base pair. Together, the results of these studies are in agreement with previous infrared (IR) linear dichroism studies of the conformation of the sugar-phosphate backbone in NaDNA-netropsin complexes, which showed that the B-A transition is suppressed for r-values down to approximately 0.1 drug/base pair (Fritzsche, H., Rupprecht, A. and Richter, M., Nucleic Acids Res. 12 (1984) 9165-9177).

Animals↗
PubMed1992

[Steroid and protein hormone concentrations in serum and follicular fluid after stimulation for in vitro fertilization].

Sixty patients with tubal infertility were stimulated for IVF with a fixed schedule consisting of clomiphene and pure follicle stimulating hormone. They responded with an optimal estradiol increase and 2 to 4 embryos were transferred. Conception cycles (n = 17) could be differentiated from non-conception cycles (n = 43) by serum estradiol, serum progesterone, the serum progesterone/estradiol-ratio and serum LH concentrations. Testosterone, androstenedione and FSH in serum and follicular fluid showed no significant relation to a possible therapy outcome. We conclude from our findings, that, during the peri-implantation period, certain LH patterns followed by an optimal progesterone/estradiol-ratio in the serum support an embryo survival after transfer to the uterus.

Androstenedione↗
PubMed1992

Abbott IMx and serono MAIAclone assays compared for lutropin determinations in urine.

The urinary lutropin (luteinizing hormone; LH) profiles of 20 patients were determined in 10 consecutive urine samples (n = 200) with a manual technique (MAIAclone, Serono; y) and a fully automated (Abbott IMx; x) technique. For 132 single determinations within the range of detection, the regression line was y = 1.39 x - 0.07 (r = 0.85). Retrospective analysis of the LH profiles obtained by the IMx yielded the classification "not pregnant" (negative) in 14 cases, of which 13 were correctly classified; 6 profiles were classified as "pregnant" (positive), which correlated with the clinical findings in 4 cases. Nine of the LH profiles analyzed with the MAIAclone method were classified as negative, which was correct in seven cases. Retrospective analysis of 11 LH profiles established with the MAIAclone assay gave positive results, which agreed with the clinical outcome in three cases. The diagnostic sensitivity of the IMx and MAIAclone methods was 87% and 47%, respectively; diagnostic specificity was 80% and 60%, respectively. In smaller series (< or = 40 samples), the IMx method has considerable advantages over the MAIAclone method in cost and convenience, because standard curves can be stored and assays can be performed as single determinations.

Autoanalysis↗
PubMed1991

[Significance of a specific LH profile after follicle stimulation for producing a pregnancy with IVF/ET].

We report on a retrospective study of LH-profiles after follicular augmentation for in vitro fertilization in order to be able to predict more precisely the chance of success. In 30 out of 34 patients we were able to retrospectively characterize the patients as potentially pregnant or not pregnant. In a prospective application of this statistical method, it should be possible to decide on the basic of specific LH-profiles whether to continue with follicular aspiration or to cancel the cycle in order to increase the pregnancy rate.

Chorionic Gonadotropin↗
PubMed1990

Modulation of the B-A transition of DNA by potential antitumor antibiotics. Influence of the base composition of DNA.

The B-A transition of DNA in oriented films of DNA-drug complexes is more or less restricted as a consequence of drug binding as revealed by infrared linear dichroism. A fraction of DNA is irreversibly locked into the B form. This behavior is described by the number of DNA base pairs "frozen" in the B form by one drug molecule. This quantity is dependent on the DNA sequence the drug is attached to. In this paper, drug complexes of oriented films of NaDNA with a GC content of 42% from calf thymus and a GC-rich DNA from Micrococcus lysodeikticus were compared. The restriction of the B-A transition of DNA complexes with two intercalating antibiotics, aclacinomycin A and violamycin BI, is not severely influenced by the base composition of DNA. By contrast, the strong groove binding oligopeptide antibiotics netropsin and distamycin A are much less effective to restrict the B-A transition of GC-rich DNA than of AT-rich DNA. This finding is in agreement with previous results by other methods which support a model based upon a strong preference of AT clusters by these two non-intercalating drugs.

Antibiotics, Antineoplastic↗
PubMed1990

[Immunoscintigraphic follow-up studies with the 99m-Tc marked monoclonal anti-CEA antibody BW 431/26].

Repeated immunoscintigraphy with murine monoclonal antibodies was performed in only few patients because of developing HAMA (Human Anti Mouse Antibodies) and therefore high risk of allergic reactions. Patients with HAMA, which could be observed in about 26% after immunoscintigraphy, show high liver-spleen uptake of labeled monoclonal antibodies in further examinations in some cases.

Adult↗
PubMed1990

[Microsurgical therapy in tubal sterility].

In spite of the advances in the field of in vitro-fertilization, microsurgery still offers the best chances for treatment of tubal infertility. Because of the irreversible tubal wall pathology the results following microsurgical repair of the postinfectious tubal disease are limited to approximately 30%. No further improvement of the surgical technique is to be expected. According to the birth rate and the rate of extrauterine gestation, microsurgery gives the best results in the correction of filmy adhesions, fimbrial phimosis and proximal tubal occlusion. Distal tubal occlusion with development of hydrosalpinx and extremely thickness of the wall should be treated by IVF-ET. If higher rates of pregnancy are to be achieved in the future in tubal sterility, the treatment of methods (microsurgery, endoscopy and extracorporeal fertilization) must be combined.

Anastomosis, Surgical↗
PubMed1989

[NMR research on blood plasma for tumor detection--a method for mass screening?].

Recently, a simple NMR test was proposed to distinguish patients with and without malignant diseases by line-width analysis of methyl and methylene lipoprotein resonances in human plasma (4). We have reevaluated this proposed cancer detection technique at 250 MHz (magnet field strength 5.9T). The mean line width for 11 controls was 31.2 Hz (SD 4.1 Hz). For 8 patients with untreated malignant tumors, the line width was 27.5 Hz (SD 3.9 Hz). The data confirm the reported lower line widths of human plasma NMR resonances for patients with malignant tumors compared with controls (4). However, the statistical significance (P greater than 0.07) does not justify to use this technique for individual differential diagnostic purposes without further improvements of the method.

Biomarkers, Tumor↗
PubMed1989

[Synchronous occurrence of neoplasias of the thyroid gland and hyperthyroid nodular struma in an endemic area].

The simultaneous occurrence of hyperthyroidism and differentiated carcinoma of the thyroid gland is more frequent than previously assumed. In our endemic goiter region 16.5% of patients with thyroid carcinoma have hyperthyroidism and 1.8% of patients with hyperthyroidism have a thyroid carcinoma. The tumors are predominantly located in autonomous adenomas but are also found in cold nodules. Not only scintigraphically cold nodules but also warm and hot nodules must be suspected of malignancy. Consistent preoperative cytodiagnosis of all goiter nodules, including hot nodules, is therefore recommended. Surgical treatment of toxic multi-nodular goiters should be considered more often.

Adenoma↗
PubMed1988

[The significance of specific LH patterns before and following ovulation induction with hCG within the scope of in vitro fertilization and simplified diagnosis].

In 55 patients follicular stimulation for in vitro fertilisation (IVF) was carried out with a combination of clomiphene (Cl)/human follicle stimulating hormone (FSH) and human chorion gonadotropin (hCG) for ovulation induction. Two days before the anticipated hCG application LH measurements in 4-hourly urine samples were started and continued until follicular aspiration. A LH-IRMA (LH-MAIAclone, Serono) utilising monoclonal antibodies enabled the detection of LH also after hCG. In order to facilitate the organisation and to exclude sources of error the LH concentrations were correlated to the urinary creatinine concentrations and expressed as LH units per gram creatinine (LH U/g Cr). 6 characteristic LH profiles could be found: 31 patients (group a) had a baseline between 5-12 LH U/g Cr with an abrupt increase 10-12 hours after hCG, 2 patients (group b) had slightly elevated LH levels (10-15 LH U/g Cr), after hCG a decrease and 20-30 hours later a distinct increase. 7 patients (group c) had an endogenous LH surge before the hCG application. 3 patients (group d) had very low LH values (below 5 LH U/g Cr), 6 patients (group e) markedly increased concentrations (above 20 LH U/g Cr) with no change after hCG. 6 patients (group f) had significant LH fluctuations. Of the 15 pregnancies 12 were in group a, 2 in group b, 1 in group c, none in the groups d-f. The good correlation between the LH concentrations and creatinine concentrations in the urine proved the usefulness of this method and contributed well to organisational simplifications.(ABSTRACT TRUNCATED AT 250 WORDS)

Chorionic Gonadotropin↗
PubMed1988

Phosphate catalyzed exchange rates of NH-N protons of DNA.

We have studied the catalysis of the exchange of the hydrogen-bonded NH-N protons of the short DNA helix (d-CCAAGCTTGG)2 by phosphate addition. The NH exchange rates were monitored by the line widths of the corresponding NH resonances in the 1H nmr spectra. The exchange catalyst phosphate is most effective on the exchange rate of the terminal CG1 base pairs. However, all internal base pairs are also moderately affected by phosphate which suggests an exchange mechanism governed by a fast equilibrium between opened and closed states of the duplex. Within the limits of error the same effectiveness of phosphate on the exchange rate of all internal NH-N protons has been observed. With the exception of the terminal base pairs, no sequence and/or position specificity of the exchange rates of the NH-N protons of the base pairs has been found.

Base Sequence↗
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↗