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Biomedical subjects

M Busch

Publications and source records attributed to M Busch.

At least 19 recordsLinked to original sources
PubMed1992

Spatial control of the gap gene knirps in the Drosophila embryo by posterior morphogen system.

The gap genes of Drosophila are the first zygotic genes to respond to the maternal positional signals and establish the body pattern along the anterior-posterior axis. The gap gene knirps, required for patterning in the posterior region of the embryo, can be activated throughout the wild-type embryo and is normally repressed from the anterior and posterior sides. These results provide direct molecular evidence that the posterior morphogen system interacts in a fundamentally different manner than do hunchback and bicoid, which are responsible for anterior pattern formation.

Animals↗
PubMed1992

Psychoactivity and abuse potential of sumatriptan.

Sumatriptan is a 5-HT1D agonist of therapeutic use in migraine and cluster headaches. To determine the profile of psychoactivity and abuse potential, a double-blind Latin-square crossover study was conducted in 12 male subjects with histories of substance abuse. The effects of subcutaneous placebo, sumatriptan (8 and 16 mg), and morphine (10 and 20 mg) were assessed on measures of subjective, behavioral, and physiologic responses including signs, symptoms, Addiction Research Center Inventory scales, onset of drug effects and miosis. Sumatriptan was psychoactive, was discriminated from placebo, produced a dose-related decrease on euphoria scores, elevated scores on measures of apathetic sedation and disliking, and lacked identification as a prototypic drug of abuse. There were no clinically significant effects on heart rate, pupil size, or blood pressure. In contrast, morphine (the positive control) produced expected dose-response relationships on measures of reinforcing and physiologic effects. The study suggests that sumatriptan has a low abuse potential.

Adult↗
PubMed1992

[Case reports on the importance of the locoregional radiotherapy of Merkel cell tumor].

The Merkel cell tumor is becoming an increasingly diagnosed primary neoplasm of the skin. This subepidermal tumor is commonly located on the head and neck or extremities of elderly patients. Occasionally misinterpreted as cutaneous metastases, they show a high rate of local recurrence (27 to 52%) and distant metastatic spread (18 to 52%). The definitive diagnosis can be made with immunohistochemistry. Wide surgical excision with postoperative irradiation to the local site and regional lymphatics is the therapy of choice. In seven patients we describe management strategies and discuss their clinical results.

Adult↗
PubMed1992

A skin MR-marker for radiation treatment planning.

After experiences with fluid filled tubes a gel fitted with an adhesive has been developed, to reproducibly markate treatment ports on the patient's skin. A gel is chosen, that hinders loss of the fluid and smoothly fits to the skin surface due to the adhesive. The clinical use of the gel hopefully will help with the use of NMR image information in radiotherapy treatment planning.

Equipment Design↗
PubMed1991

An improved microcomputer program for finding gene- or gene family-specific oligonucleotides suitable as primers for polymerase chain reactions or as probes.

We present here an easy-to-use computer program which finds oligonucleotides suitable as primers in polymerase chain reactions (PCR) or as probes for hybridization. In contrast to other programs used for this purpose, the additional advantage of this one is the possibility of directly detecting gene- as well as gene family-specific oligonucleotides. For this purpose, up to 200 different DNA sequences, of maximally 65,000 nucleotides each, can be scanned in a single search to ensure either single or multiple gene binding of the PCR primers or probes. Specific oligonucleotides for genes carrying internal repetitions and for single genes belonging to a set of highly conserved genes can also be detected. Many parameters such as exclusion of simple sequences, which are known to be highly repeated throughout various genomes or regions of stable secondary structures in both primer-primer and primer-template, can be taken into consideration and avoided. Furthermore, the G + C content and the length of the oligonucleotides can be changed in a broad range by the user.

Animals↗
PubMed1991

Detection of HIV-1 in Entamoeba histolytica without evidence of transmission to human cells.

Intestinal protozoa like Entamoeba histolytica and Giardia lamblia have been proposed as vectors or cofactors in the development of AIDS. To determine whether these protozoa could transmit HIV, laboratory strains of protozoa were cocultured with cells chronically infected by a highly replicative strain of HIV-1. Entamoeba histolytica, but not Giardia lamblia, took up virus. Immunologically detectable HIV-1 was present in the amebae up to 48 h after exposure to infected cells, but this virus could not be transferred to uninfected human cells. Amebae isolated directly from two HIV-infected individuals were also found to be positive for HIV-1. After lysis of these protozoa and coculture with uninfected peripheral blood mononuclear cells, no transfer of virus to the human cells was observed.

Animals↗
PubMed1991

Distribution and phylogenetic significance of 27-hydroxy-octacosanoic acid in lipopolysaccharides from bacteria belonging to the alpha-2 subgroup of Proteobacteria.

Lipopolysaccharides (LPSs) from a number of bacteria belonging to the alpha-2 subgroup of the class Proteobacteria were screened for the presence of 27-hydroxy-octacosanoic acid (27-OH-28:0). With few exceptions, most of the bacteria contained 27-OH-28:0 in their lipid A fractions. In addition, some of the bacteria contained other n-2-hydroxylated long-chain fatty acids hitherto not reported. The distribution of 27-OH-28:0 was restricted to the alpha-2 subgroup. LPSs from members of the other subgroups (the beta and gamma subgroups), including some well-characterized enterobacterial LPSs, were devoid of 27-OH-28:0. Our results indicate that the presence of n-2-hydroxylated long-chain fatty acids in LPSs might be used as a chemophylogenetical marker.

Hydroxy Acids↗
PubMed1991

Leukocyte filtration removes infectious particulate debris but not free virus derived from experimentally lysed HIV-infected cells.

We used in vitro model of storage-induced leukocyte degradation in blood to experimentally characterize the infectivity of the debris of lymphocytes harboring human immunodeficiency virus (HIV-1). The leukocyte filtration process removed both intact HIV-infected H9 cells and the particulate debris, but failed to remove the cell-free HIV released from lysed cells. These data suggest that the leukocyte filtration of donor blood soon after collection would optimally reduce the particulate infectious burden of blood for transfusions.

Blood Transfusion↗
PubMed1991

[Aluminum, steel and tungsten portal film cassettes for the imaging verification of 60Co photon irradiation up to 42 MV in a clinical trial].

The movement of the patient lowers the contrast of the portals, because the exposition time is long and identical with the treatment time. To enhance the contrast in the portals, the first models of the cassettes were modified under the clinical tests by a rear sheet nearly free from backscattering. With the modified cassettes iodine contrast media are weakly seen on the portals in the laboratory tests, but not in the clinical routine.

Aluminum↗
PubMed1991

[The intracavity radiotherapy of cervical carcinoma with flexible applicators following the vesicovaginal interposition of the uterus].

Advantages of new flexible intracervical applicators treating cervical cancer with high dose rate afterloading brachytherapy are reported: The insertion of the flexible applicator is usually possible without anesthesia and dilation of the cervix. Therefore the treatment can be performed on an outpatient basis. The risks of perforation and infection are minimal. Dosimetry and documentation of the applicator geometry are possible, if the planning system allows the definition of individual curves of an individual applicator. We now prefer flexible applicators instead of rigid steel applicators treating cervix carcinoma.

Brachytherapy↗
PubMed1991

Definitive radiation therapy in the treatment of carcinoma of the uterine cervix. Treatment results and prognostic factors.

219 patients suffering from cervix carcinoma received definitive radiation therapy using moderate doses of external beam therapy and high dose-rate afterloading brachytherapy from 1979 to 1986. At five years, the actuarial survival (AS) for stage Ib patients was 81%, for stage IIa 53%, for stage IIb 56%, for stage IIIa 25%, for stage IIIb 33% and for stages IVa and IVb 0%. Significant prognostic factors for actuarial survival were FIGO stage, histological type, grading and, marginally, age of the patient at the time of diagnosis. The survival data censored for death caused by intercurrent disease (tumor related survival, TUS) at five years were: 90% (Ib), 66% (IIa), 63% (IIb), 50% (IIIa), 41% (IIIb) and 0% (IVa and IVb). The prognostic factors were stage and grading. Age and histology failed to be a significant prognostic factor. The disease-free survival (DFS) according to FIGO stage at five years were: Ib 84%, IIa 64%, IIb 59%, IIIa 50%, IIIb 38%, IVa and IVb 0%. Prognostic factors for disease-free survival were limited to FIGO stage and grading. The five-year local control results (LC) according to stage were 90% (Ib), 64% (IIa), 67% (IIb), 43% (IIIb) and 0% (IVa and IVb) with stage as prognostic factor. High dose-rate afterloading therapy for cervix carcinoma yields good results for local control and survival with a low ratio of severe side effects (6%). Radiation therapy eliminates the prognostic influence of histological type and grading of the tumor on local control. External beam and afterloading doses, however, are relevant factors for prognosis, if the patients are stratified by FIGO stage.

Adenocarcinoma↗
PubMed1990

Brucella abortus 16S rRNA and lipid A reveal a phylogenetic relationship with members of the alpha-2 subdivision of the class Proteobacteria.

On the basis of ribosomal 16S sequence comparison, Brucella abortus has been found to be a member of the alpha-2 subdivision of the class Proteobacteria (formerly named purple photosynthetic bacteria and their nonphototrophic relatives). Within the alpha-2 subgroup, brucellae are specifically related to rickettsiae, agrobacteria, and rhizobiae, organisms that also have the faculty or the obligation of living in close association to eucaryotic cells. The composition of Brucella lipid A suggests a close phylogenetical relationship with members of the alpha-2 group. The chemical analysis of the lipid A fraction revealed that Brucella species contain both glucosamine and diaminoglucose, thus suggesting the presence of a so-called mixed lipid A type. The serological analysis with polyclonal and monoclonal antibodies is in agreement with the existence of mixed lipid A type in B. abortus. The amide-linked fatty acid present as acyl-oxyacyl residues were 3-O-C(16:0)12:0, 3-O-C(16:0)13:0, 3-O-C(16:0)14:0, and 3-O-C(18:0)14:0. The only amide-linked unsubstituted fatty acid detected was 3-OH-C16:0. The ester-linked fatty acids are 3-OH-C16:0, 3-OH-C18:0, C16:0, C17:0, and C18:0. Significant amounts of the large-chain 27-OH-C28:0 were detected together with traces of 25-OH-C26:0 and 29-OH-C30:0. Comparison of the Brucella lipid composition with that of the other Proteobacteria also suggests a close phylogenetical relationship with members of the alpha-2 subdivision. The genealogical grouping of Brucella species with pericellular and intracellular plant and animal pathogens as well as with intracellular plant symbionts suggests a possible evolution of Brucella species from plant-arthropod-associated bacteria.

Bacteria↗