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Biomedical subjects

M Busch

Publications and source records attributed to M Busch.

At least 91 records · Page 5Linked to original sources
PubMed1995

[Paranasal sinus mycetoma with orbital involvement in a patient with AIDS].

A patient with AIDS was hospitalized with a left-sided face swelling and protrusion of the bulbus. After cranial computed tomography and fine-needle aspiration biopsy of the fossa temporalis we diagnosed a mycetoma; localisation and histology made an aspergilloma most probable. Antimycotic therapy led to complete remission of the symptoms. Post mortem we only could culture Candida albicans out of the abscess cavity.

AIDS-Related Opportunistic Infections↗
PubMed1994

Duration of time from onset of human immunodeficiency virus type 1 infectiousness to development of detectable antibody. The HIV Seroconversion Study Group.

BACKGROUND: For persons newly infected with the human immunodeficiency virus type 1 (HIV-1), the time from the onset of infectivity to the development of detectable HIV-1 antibody is unknown. Persons who donate blood during this period account for nearly all instances of HIV-1 transmission from HIV-1 antibody-screened blood transfusions. STUDY DESIGN AND METHODS: To estimate the window period from infectivity to HIV-1 antibody positivity, 701 HIV-1-seropositive blood donors who made a previous seronegative donation at 40 United States blood centers were studied. The HIV-1 antibody status was determined for at least one recipient of blood from the seronegative donation preceding the seropositive donation made by 182 of the 701 donors. RESULTS: There were 39 seropositive recipients of blood from these 182 donors. Three donors were excluded from further analysis because the seropositive recipients of their blood had other HIV-1 risk factors or had HIV-1 infection before transfusion. The final study population comprised the remaining 179 donors, of whom 36 (20%) transmitted HIV-1 infection to recipients. When the interval between the seropositive donation and the preceding seronegative donation was less than 180 days, 46 percent of the donors transmitted HIV-1. In contrast, when that interval exceeded 540 days, only 2 percent transmitted HIV-1. A mathematical model was developed to explain the relationship between the probability that the previous seronegative donation occurred during the donor's window period of infectiousness, and hence transmitted HIV-1, as a function of both the window period and the duration between the seropositive and previous seronegative donations. This model indicated that the transmission data were most consistent with an average window period of 45 days. Assuming a log-normal window period distribution, it was estimated with 95 percent certainty that at least 90 percent of persons had a window period of less than 141 days. CONCLUSION: The window period averages 45 days, with few, if any, donors remaining infectious and seronegative for longer than 6 months.

Adolescent↗
PubMed1994

Absence of recoverable infectious virus and unique immune responses in an asymptomatic HIV+ long-term survivor.

We have studied a woman with transfusion-acquired HIV who appears to have contained infectious virus to consistently undetectable levels over a 13-year period without antiviral treatment. She received the infected transfusion for intra- and postpartum blood loss immediately after delivery of her second child in 1981. She had no acute febrile syndrome and has never had HIV-associated clinical signs or symptoms in the 13 years since infection. She was first tested and found positive for HIV antibodies in 1985, and the infected blood donor was diagnosed with AIDS in 1986 and died of AIDS-related complications in 1989. Two other recipients of packed erythrocytes from this donor (in 1980 and 1982) also became infected and were subsequently diagnosed with AIDS. Between January 1986 and April 1994, in the setting of continuous and unambiguous Western blot HIV-specific antibodies and intermittently positive low-level HIV DNA signal after polymerase chain reaction (PCR) amplification, more than 30 separate cell cocultures performed in several independent laboratories failed to yield evidence of infectious virus, despite special efforts to induce and detect HIV replication. Immunologically, a strong in vitro proliferative response to HIV envelope proteins also distinguished this subject from other asymptomatic HIV+ individuals.

Adult↗
PubMed1994

Assessment of hepatitis C virus RNA levels by quantitative competitive RNA polymerase chain reaction: high-titer viremia correlates with advanced stage of disease.

A quantitative competitive RNA polymerase chain reaction (QC-PCR) assay was developed for measuring absolute levels of hepatitis C virus (HCV) RNA in the sera of 121 viremic persons, including 64 asymptomatic blood donors, 39 symptomatic patients referred for treatment of chronic hepatitis C, and 18 patients with end-stage liver disease referred for liver transplantation. Mean HCV RNA levels (log molecules per milliliter) were lowest among blood donors with normal alanine aminotransferase (ALT) values (5.8 +/- 1.5), higher among blood donors with elevated ALT (6.9 +/- 0.8) and clinic patients with chronic active hepatitis (6.9 +/- 0.7), and highest among patients with cirrhosis (7.1 +/- 0.8) or end-stage liver disease (7.6 +/- 1.0). High-titer viremia ( > or = 7.5 logs/mL) was more frequent among patients with end-stage liver disease (14/18; 78%) than either blood donors (10/64; P < .001) or patients with chronic active hepatitis (7/26; P < .001). Thus, 121 (94.5%) of 128 anti-HCV-positive persons were viremic. QC-PCR may be valuable for monitoring HCV infection status and selecting individuals for therapy.

Base Sequence↗
PubMed1994

Evaluation of a p21e-spiked western blot (immunoblot) in confirming human T-cell lymphotropic virus type I or II infection in volunteer blood donors. The Retrovirus Epidemiology Donor Study Group.

Current algorithms for the serologic confirmation of human T-cell lymphotropic virus type I and II (HTLV-I/II) antibody reactivity are complicated. We evaluated the performance of an HTLV-I Western blot (immunoblot) spiked with recombinant p21e protein (p21e WB) as an alternative to current confirmatory methods. These methods include the HTLV-I viral lysate Western blot and either a radioimmunoprecipitation assay or a p21e enzyme-linked immunosorbent assay. Five hundred fifty nine blood donations obtained from five U.S. blood centers and classified as HTLV-I/II seropositive (n = 149) or seroindeterminate (n = 410) by routine testing methods were further evaluated by PCR for proviral DNA and by the p21e WB. On the basis of serologic and PCR testing, 155 donations were classified as HTLV-I/II infected. The sensitivity of the p21e WB was 97.4%, slightly exceeding that of routine confirmatory testing. The specificity of the p21e WB was 97.5%, as determined by testing of 404 seroindeterminate samples that were negative in the PCR. The positive predictive value of the p21e WB was 94%. In contrast, the specificity and positive predictive value of routine confirmatory testing were both 100%. Follow-up sampling of presumptive p21e WB false-positive donors substantiated the absence of HTLV-I/II infection. Although the p21e WB used in this study has high sensitivity and may be useful as a confirmatory assay in epidemiologic research studies, it may not be ideal as a confirmatory test for the notification of blood donors.

Blood Donors↗
PubMed1993

Software FIACRE: bioprocess monitoring on the basis of flow injection analysis using simultaneously a urea optode and a glucose luminescence sensor.

Various computer programs for large-scale bioprocess control and optimization have been developed as well as software for simple laboratory routine analysis. In comparison, software can hardly be found that works on laboratory scale and provides the control of complex flow injection analysis (FIA) systems, multisubstrate determination, data evaluation as well as minimal process control abilities. The sensors applied can be of different type (luminometric or other optical as well as electrochemical biosensors). The development of such a software may be very helpful for the transfer of FIA/biosensor systems from the state of development to industrial processes. Hence, each analysing system--even a well established biosensor--has to be individually adapted to the process, a task which is best done under laboratory conditions. Such a flexible, computer-controlled FIA system for research level based on the software FIACRE is presented. Five FIA/(bio)sensor system can be controlled simultaneously. Additionally, common temperature and pH recordings are possible. Determinations of substrate concentrations are performed by means of calibration curves which can be recorded at different times. This allows supervising the activities of the sensors during a cell cultivation and controlling the bioprocess, e.g. by adding substrate to a cell culture. The automated monitoring of the degradation of glucose and urea by two different optical sensing principles during a cell cultivation under the control of one microcomputer is presented for the first time. For this purpose, already well examined biosensors (a urease optode and a luminometric glucose sensor) were employed and their properties discussed under the aspect of working in real cultivation media. It will also be shown that substrates being of interest for bioprocess control can be detected by slight modifications of known reactions. For example, substrates of NADH-dependent enzymatic reactions can be detected by the luminol chemiluminescence system, and optodes can be employed for pH, penicillin and glucose determination.

Alcohol Dehydrogenase↗
PubMed1993

Cyanopeptolins, new depsipeptides from the cyanobacterium Microcystis sp. PCC 7806.

Four depsipeptides (peptide lactones), called cyanopeptolins A, B, C and D, have been isolated from the cyanobacterium Microcystis sp. PCC 7806. They possess identical structures consisting of cyclic L-glutamic acid-gamma-aldehyde, L-leucine, N-methyl-phenylalanine, L-valine, L-threonine, L-aspartic acid, hexanoic acid and a variable basic amino acid. This variable amino acid can be L-arginine (cyanopeptolin A), L-lysine (cyanopeptolin B), N epsilon-methyl-L-lysine (cyanopeptolin C) and N epsilon,N epsilon-dimethyl-L-lysine (cyanopeptolin D), respectively. The L-glutamic acid-gamma-aldehyde and the amino group of L-leucine form an unusual 3-amino-6-hydroxy-2-oxo-1-piperidine system. L-Threonine is connected to L-valine via its hydroxy-group forming an ester bonding. The hexanoic acid residue is attached to the N-terminal aspartic acid residue which is not a part of the ring structure. The isolation procedure of the four cyanopeptolins as well as structure elucidation are described. Amino acid analysis, GC/MS analysis, FAB-MS and several NMR techniques were used to reveal the structures.

Amino Acid Sequence↗
PubMed1993

[A comparative consideration of para-aortic fields within the framework of the German Hodgkin's Disease Study].

In 33 patients of the multicenter German Hodgkin's Lymphoma Study Group the field borders of the paraaortic field were compared computer-assisted. It was seen that fields are chosen often too small or too large, though precise description of the fields is given in the protocol. In these patients the para-aortics were irradiated exclusively as extended field region. In addition to the above observation the clipping of the spleen pedicle provides the optimal help for correct positioning of this field. Overall a very low frequency of lymphatic clipping is observed, though clinical needs are obvious.

Aorta↗
PubMed1993

[Diabetes insipidus and breast carcinoma--the importance of NMR tomography (MRT) in therapy planning].

In patients with advanced breast cancer the incidence of diabetes insipidus is between 0.1% and 0.9%. Satisfactory symptomatic relief can be obtained with Desmopressin-acetate. In the presence of this symptom complex magnetic resonance imaging (MRI) can aid in the detection of metastases to the posterior pituitary. By the use of magnetic resonance imaging, the incidence for and implementation of local radiotherapy can be firmly grounded.

Adult↗
PubMed1993

Radiation therapy verification in brachytherapy combining iron sulphate gel irradiation and magnetic resonance imaging (MRI).

We developed a verification method that allows the three-dimensional qualitative delineation of the dose inside an applicator during intracavitary brachytherapy using MRI of dose-dependent changes of iron sulphate. In addition to computer calculations, the verification of the dose distribution is depicted now within the applicator. Therefore one can get a qualitative information about the relative position of the applicator according to the tumor volume and the desired brachytherapy radiation volume.

Brachytherapy↗
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↗