PubMed Health⌕ Search

Biomedical subjects

H Müller

Publications and source records attributed to H Müller.

At least 433 records · Page 24Linked to original sources
PubMed1990

Cytogenetics of breast cancer.

Chromosome counts were performed on 1,100 cells from 17 malignant breast carcinomas and on 168 cells of four normal tissue samples after amethopterin treatment and G-banding. Karyotypes were established from 216 cells of 11 tumor-derived cultures and from 47 cells of four nonmalignant tissue-derived cultures. Karyotypes of cells from nonmalignant samples showed a normal diploid chromosomal constitution with no consistent loss or gain of a specific chromosome. Structural chromosomal abnormalities were not observed. Tumor-derived cultures could be distinguished from normal cultures on the basis of a significantly increased incidence of numerical changes and structural chromosomal aberrations. In nine of 11 tumor-derived cultures, numerically normal cells were shown to be pseudodiploid, with frequencies ranging to 43% (mean, 13.2%) of the diploid cells. In agreement with previous reports, cytogenetic analyses showed predominantly diploid cells. Clonal numerical changes of chromosomes 17, 18, 20, and 21 could be detected in three tumor samples. Clonal structural abnormalities could be observed in two of 11 analyzed tumours. A t(6;12)(p21;p13) and an enlarged chromosome 7 (7q+) were found in a patient with invasive ductal carcinoma. An inversion of chromosome 7 [inv(7)(q11.2q32)] was observed in one case, also diagnosed as invasive ductal carcinoma. The significance of these findings in relation to clinical data is discussed.

Adult↗
PubMed1990

Purified chick-embryo-cell (PCEC) rabies vaccine: its potency performance in different test systems and in humans.

The potency of purified chick embryo cell rabies vaccine Rabipur was evaluated by four different in vivo test systems: (1) NIH test with homologous strain LEP challenge; (2) intramuscular challenge of vaccinated laboratory animals; (3) postexposure vaccine treatment trials in laboratory animals; and (4) antibody induction tests in laboratory animals. These different test systems were compared with the Standard NIH test and an in vitro test, the modified ABT. Each of the four in vivo methods chosen demonstrated potency values superior to that of the Standard NIH test in which challenge was with CVS strain. Potency relations were: Standard NIH test versus alternative methods versus modified ABT 1.0-2.2-1.85 respectively. There was good correlation between alternative in vivo methods and the ABT. In addition examples of antibody induction in man following administration of various postexposure treatment regimens are presented which lead to the conclusion that postexposure vaccination method and composition of the study group play a more important role in achieving optimum treatment results than vaccine potency, provided that it corresponds to WHO requirements (minimum 2.5 IU per dose).

Animals↗
PubMed1990

Malignancies in families of women with medullary, tubular and invasive ductal breast cancer.

Breast cancer seems to represent a heterogeneous group of neoplasia originating from the parenchymal epithelium of the mammary gland. Family studies combined with genetic epidemiological analyses and histological evaluations were used to gain an insight into this nosological entity. Special emphasis was given to the type and frequency of neoplasia in close relatives. This study represents pedigrees of 36 histologically defined pure tubular and 22 pure medullary breast cancer patients as well as 171 with the invasive ductal form. The incidence of cancer in the first degree relatives of all three groups is compared to that of the local population. The first degree relatives did not have a higher risk (RR) for the neoplastic diseases. However, breast cancer occurs more frequently in the female relatives of all three groups. Other cancers have different relative risks.

Adenocarcinoma↗
PubMed1990

Mandibular invasion by oral squamous cell carcinoma. Clinical aspects.

In this paper we have tried to correlate the clinical and radiological aspects to the histological findings in squamous cell carcinomas of the oral cavity, in relation to bone involvement in the mandible. 52 patients were analyzed and we conclude that there is a positive indication for mandible sparing surgery, even if there is fixation to the jaw or radiologically visible bone involvement.

Alveolar Process↗
PubMed1990

Juvenile ossifying fibroma. Report of four cases.

The present investigation concerns 4 patients with juvenile ossifying fibroma (JOF) whose data are analyzed together with 30 cases from the literature. The tumour mainly occurs in juveniles, 79% of the patients being 15 years or younger. Radiologically as well as at surgery, the lesion is demarcated from its surroundings. Histologically, JOF is unique in showing a loose-fibroblastic stroma that contains garland-like strands of osteoid with entrapped osteoblasts, the latter feature not being observed in other fibro-osseous lesions. JOF responds very well to conservative treatment that provided permanent cure in all cases with adequate follow-up data.

Child↗
PubMed1990

Differential diagnosis of fibro-osseous jaw lesions. A histological investigation on 30 cases.

A series of 30 fibro-osseous jaw lesions was evaluated for histological parameters that enable appropriate diagnostic classification. Special emphasis was laid upon the histomorphology of the lesion-jawbone interface, blending of lesional bone with adjacent jawbone being employed as the decisive factor in distinguishing between fibrous dysplasia and other fibro-osseous jaw lesions. Using this feature as a discriminative tool, other histological aspects that were useful in differential diagnosis could be identified. Fibrous dysplasia (n = 11) shows a rather uniform appearance with a constant ratio bone: fibrous tissue throughout the entire lesion; acellular mineralized particles are virtually absent. Juvenile ossifying fibroma (n = 3) is characterized by a highly cellular fibroblastic stroma and garland-like strands of cellular osteoid. Ossifying fibroma (n = 12) shows a high variability in stromal cellularity and types of mineralized material. Localized periapical fibro-osseous cemental lesions (n = 4) are histologically almost similar to ossifying fibroma although more heavily mineralized. It is concluded that there is full agreement between histology and radiology in indicating whether a fibro-osseous jaw lesion is demarcated or blends into its surroundings. Moreover, an appropriate diagnosis can be reliably made on histological grounds.

Adolescent↗
PubMed1990

Sec2 protein contains a coiled-coil domain essential for vesicular transport and a dispensable carboxy terminal domain.

SEC2 function is required at the post-Golgi apparatus stage of the yeast secretory pathway. The SEC2 sequence encodes a protein product of 759 amino acids containing an amino terminal region that is predicted to be in an alpha-helical, coiled-coil conformation. Two temperature-sensitive alleles, sec2-41 and sec2-59, encode proteins truncated by opal stop codons and are suppressible by an opal tRNA suppressor. Deletion analysis indicates that removal of the carboxyl terminal 251 amino acids has no apparent phenotype, while truncation of 368 amino acids causes temperature sensitivity. The amino terminal half of the protein, containing the putative coiled-coil domain, is essential at all temperatures. Sec2 protein is found predominantly in the soluble fraction and displays a native molecular mass of greater than 500 kD. All phenotypes of the temperature-sensitive sec2 alleles are partially suppressed by duplication of the SEC4 gene, but the lethality of a sec2 disruption is not suppressed. The sec2-41 mutation exhibits synthetic lethality with the same subset of the late acting sec mutants as does sec4-8 and sec15-1. The Sec2 protein may function in conjunction with the Sec4 and Sec15 proteins to control vesicular traffic.

Amino Acid Sequence↗
PubMed1990

Demonstration of enzyme activities required for cap structure formation in infectious bursal disease virus, a member of the birnavirus group.

The putative viral transcriptase p90 in infectious bursal disease virus (IBDV) was shown to form an enzyme-guanylate intermediate which is indicative of guanylyl-transferase activity. The p90-nucleotide bond is most likely to be a phosphodiester linkage, as it resisted treatment with HCl and NH2OH but was sensitive to NaOH. This is in contrast to phosphoamide bonds formed by reovirus cores. Methyltransferase activity was also demonstrated in IBDV, and is closely associated with transcription, suggesting that p90 may be a multifunctional enzyme.

Animals↗
PubMed1990

A comparison of the sequences of segment A of four infectious bursal disease virus strains and identification of a variable region in VP2.

The nucleotide sequences of the large open reading frame (ORF) from segment A of three European strains of infectious bursal disease virus (IBDV) have been determined using cDNA clones. This ORF of 3036 nucleotides encodes the virion proteins as a polyprotein in the following order: VP2, VP4, VP3. The nucleotide sequences determined have been compared to each other and to the published sequence of an Australian strain. The four strains are closely related, the greatest difference between two strains being 7.7% at the nucleotide level and 2.7% at the amino acid level. Comparisons show that there is a tight cluster of amino acid changes in the virion protein VP2. This variable region corresponded to the region where binding of a neutralizing monoclonal antibody has previously been mapped. A region in the centre of the segment, corresponding to the N terminal of VP4, was found to be completely conserved. Amino acid changes were spread fairly evenly through VP3 and there was no indication of a variable region as found in VP2.

Amino Acid Sequence↗
PubMed1990

[Safety monitoring of disposable medical products].

In 1988 medical devices have become a part of the German AMG. According to this law safety monitoring similar to the one with drugs should be introduced. In the United States the so called medical device report regulation is responsible for safety monitoring. They have demonstrated that the risks of these instrument cannot be neglected. Therefore medical organisations or technical supervising institutions in Germany should take care of safety monitoring with medical devices, because otherwise supranational organisations, which are already present in different countries, or European community authorities will become responsible after the introduction of the free European market in 1992.

Catheters, Indwelling↗
PubMed1990

Different Epstein-Barr virus expression in lymphomas from immunocompromised and immunocompetent patients.

Eighteen tissue samples from lymphoproliferative lesions and lymphomas in immunodeficiency states were investigated for their content of Epstein-Barr virus (EBV) genome by dot blotting and for the distribution of EBV in tissue sections by in situ hybridization. Fourteen lymphomas from AIDS patients and four children with disorders of the immune system were available. For control reasons, six cases of infectious mononucleosis (IM) and eight Burkitt's lymphomas (BL) from malaria-free regions of Africa were included in the study. Two different patterns of EBV distribution are described: 1) heterogeneous scattered EBV-positive cells, as originally seen in IM and therefore called the IM-type pattern, 2) and a BL-type pattern seen in endemic Burkitt's lymphoma with homogeneous EBV-positive cells all over the tumor. In lymphomas in patients with inborn immunodeficiencies, an IM-type pattern was found. In lymphomas from AIDS patients, the two different patterns were found. There were lymphomas with the IM-type pattern as well as some with the BL-type pattern. In some AIDS-associated lymphomas, both patterns occurred in one tumor. The findings suggest that it is not the disease process that is the distinguishing feature between the two patterns of EBV infection but rather the patient's underlying disease and the extent of this disease.

Acquired Immunodeficiency Syndrome↗
PubMed1990

[Comparison of HIV-associated dyshemopoiesis in myelodysplastic HIV-negative patients].

Bone marrow biopsies of 23 HIV-1 infected patients and 29 patients with myelodysplastic disorders were examined histologically by immuno- and enzyme-histochemical techniques and morphometrical methods. The nucleolar organizer regions (AgNOR) were demonstrated and visually counted. Hypercellularity in marrows of AIDS patients is substantially caused by an increase of erythropoiesis and CD68+ macrophages/reticular cells. However, hypercellularity in preleukemia results from hyperplasia of all hematological cell lines and CD68+ bone marrow macrophages/reticular cells. AgNOR count is positively correlated with granulo- and erythropoiesis in preleukemia. In AIDS there is such a positive correlation between AgNOR count and granulopoiesis whereas an inverse relationship appears in erythropoiesis. The results suggest that HIV-associated bone marrow alterations differ from merely reactive changes and are related to myelodysplastic disorders.

Acquired Immunodeficiency Syndrome↗
PubMed1990

[Histochemical and histomorphometric studies on growth fractions in human breast carcinoma].

Nucleolar organizer regions (NOR) can easily be recognized on paraffin sections of bioptic material with an argyrophilic stain. NORs are meant to to correlate with mitotic activity of proliferating cells. This study examine wether NOR-activity corresponds with the proliferations marker KI-67. 10 fibroadenomas and 40 invasive ductal breast carcinomas were studied. For objective tumor grading the size of the nuclei was determined morphometrically. NORs, KI-67 and nuclei sizes correlate closely in fibroadenomas. In carcinomas, however, a correlation between NORs, KI-67, and the size of the nuclei could not be found. NORs and KI-67 evidently mark different cell activities. For prognostic evaluation of malignant tumors they should therefore not be used alternatively but complementarily.

Breast Neoplasms↗
PubMed1990

Structural changes within mixed populations of microtubules and protofilament ribbons caused by dilution and cold incubation.

By means of electron microscopy we have investigated the influence of dilution and cold incubation (0 degree C) on mixed populations of tubulin assemblies consisting of microtubules (MTs) and protofilament ribbons with C- and S-shaped profiles formed in the presence of glycerol. Dilution results in a partial disappearance of ribbons, whereas cold incubation causes a decrease of the percentage of MTs in favour of C-ribbons, probably produced by splitting of MT ends. In the case of dilution, we assume a lower dynamic stability of ribbons compared with MTs, which was already observed during long-time incubation of mixed population (Böhm et al., Biochem. Biophys. Acta 929, 154, 1987), whereas the splitting effect in the cold should be caused by the deficiency of MT-bound microtubule-associated proteins (MAPs), which is observed in the presence of glycerol.

Actin Cytoskeleton↗
PubMed1990

[Effect of alloxans on pancreatic B-cells with special regard to the alloxan-metal-complex theory. I. Effects of alloxan, alloxan-zinc chelates, dilauric acid and colchicine on blood sugar and rate of mitosis of B-cell Langerhans islets].

Alloxan, alloxan-zinc-chelate, sodium salt of dialuric acid, and colchicine significantly raised the blood sugar level under the previously mentioned experimental conditions 28 h after the application. The typical three-phase blood sugar curve development after alloxan (initial hyperglycemia, hypoglycemia, permanent hyperglycemia) was only approximately reached by dialuric acid which initiated, however, instead of the initial hyperglycemia a more pronounced hypoglycemic phase within the first 6 h. Alloxan-zinc-chelate protractedly and significantly made the blood sugar's increase up to the 7th d post injectionem, without being able to maintain a permanent hyperglycemia with half-normal dosage in comparison with alloxan. Non-diabetogenic alloxan doses (19 mg/kg i. v.) and the appropriate alloxan-zinc-chelate dosage (35 mg/kg) led to a significant increase of the blood sugar only in the chelate group with the long-term test up to 10 d, suggesting an increased and prolonged effect of the metal-chelates by stabilization of alloxan. The tested substances differently acted on the mitotic frequency of B-cells. The mitosis did not increase in the alloxan-zinc- and dialuric acid treated animals and was similar to normal animals far below the fractions of 1/10(6). A 4- and 5-fold increase of the mitotic frequency in the colchicine or alloxan treated animals as well as an accumulation of delayed metaphases suggest an impeded transition to the anaphase and include alloxan among the mitotic poisons.

Alloxan↗
PubMed1990

[Mechanism of action of alloxan on pancreatic B-cells with special regard to the alloxan-metal-complex theory. II. Actions of alloxan, alloxanic acid, Zn2+ and ethyleneglycol-bis-(beta-aminoethylether)-N,N'tetraacetic acid (EGTA) on the assembly of microtubule proteins (MTP) into microtubules or MPT sheets in vitro].

Analyses of the cell structures in the islets of Langerhans revealed the presence of 2 predominant cations, calcium (beta-granules and saccules, mitochondria, sac membranes, and cell membranes) and zinc (secretory granules, encasing membraneous sacs) in association with organelles which involve directional secretion. Both elements are known to interact with microtubules influencing their structural and functional properties, e.g. movement of secretory granules. Influences of Zn2+ on microtubules are investigated with a view to interactions in vitro with and without diabetogenic substances. Turbidimetry and electron microscopic investigations showed that under the conditions mentioned above, alloxan of a concentration of 2 x 10(-5) mol/l (alloxan/tubulin 1:1) inhibits the formation of microtubules and increases the portion of microtubules stabilized of 4 degrees C. The Zn2(+)-induced formation of MTP sheets is not influenced by alloxan and the metal complex forming agent EGTA, if the molar concentrations of the substance and Zn2+ are equally high. With a molar proportion of 2:1 (EGTA:Zn2+), the formation of sheets does not longer occur and only microtubules are formed, whereas neither sheets nor microtubules were assembled by alloxan with this molar proportion. However, neither the assembly of microtubules nor the formation of Zn2(+)-induced sheets are influenced by alloxanic acid in both molar proportions. It is shown that the diabetogenic alloxan influences the formation of microtubules and that performed microtubules are destroyed. This result of alloxan corresponds to its antimitotic activity analogously to the wellknown effect of colchicine (s. Schmidt et al. 1990).(ABSTRACT TRUNCATED AT 250 WORDS)

Alloxan↗
PubMed1990

[AIDS and tuberculosis--the status in Cologne].

The incidence of tuberculosis among people with AIDS in the USA is about four per cent. This is one hundred to two hundred times the incidence of that of the general population. The aim of this study is to get more detailed information about the coincidence between HIV infection/AIDS illness and tuberculosis in Cologne. 2.6% of HIV carriers or people with AIDS are also infected with mycobacterium tuberculosis; this is 81 times of that among the general population in Cologne.

Acquired Immunodeficiency Syndrome↗