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Biomedical subjects

A Krause

Publications and source records attributed to A Krause.

At least 127 records · Page 7Linked to original sources
PubMed1997

Induction of chalcone synthase expression by rhizobia and nod factors in root hairs and roots.

Chalcone synthase (CHS) of Vigna unguiculata is encoded by a gene family that is abundantly transcribed in leaves and nodules. Inoculation with Rhizobium sp. NGR234, which nodulates V. unguiculata, or with NGR delta nodABC, a mutant deficient in Nod factor production, induced rapid accumulation of CHS mRNAs in roots and root hairs. As both Nod+ and Nod- bacteria provoke responses, induction of CHS gene expression may involve symbiotic or defense responses. Four days after inoculation with the wild-type Rhizobium sp., the transcript levels increased in roots but decreased in root hairs. Use of a region unique to the 5' end of a specific CHS gene (VuCHS1) showed that increases of transcript levels in root hairs 24 h after inoculation with both rhizobia were specific to this gene. Transcripts of this gene in roots were only detectable 4 days after treatment with NGR234. It is possible therefore that accumulation of VuCHS1 follows the infection pathway of rhizobia entering legume roots. Purified Nod factors induced accumulation of transcripts, showing that they might be part of the signal transduction pathway leading to CHS expression.

Acyltransferases↗
PubMed1997

Borrelia burgdorferi induces chemokines in human monocytes.

Lyme disease is clinically and histologically characterized by strong inflammatory reactions that contrast the paucity of spirochetes at lesional sites, indicating that borreliae induce mechanisms that amplify the inflammatory response. To reveal the underlying mechanisms of chemoattraction and activation of responding leukocytes, we investigated the induction of chemokines in human monocytes exposed to Borrelia burgdorferi by a dose-response and kinetic analysis. Lipopolysaccharide (LPS) derived from Escherichia coli was used as a positive control stimulus. The release of the CXC chemokines interleukin-8 (IL-8) and GRO-alpha and the CC chemokines MIP-1alpha, MCP-1, and RANTES was determined by specific enzyme-linked immunosorbent assays, and the corresponding gene expression patterns were determined by Northern blot analysis. The results showed a rapid and strong borrelia-inducible gene expression which was followed by the release of chemokines with peak levels after 12 to 16 h. Spirochetes and LPS were comparably effective in stimulating IL-8, GRO-alpha, MCP-1, and RANTES expression, whereas MIP-1alpha production preceded and exceeded chemokine levels induced by LPS. Unlike other bacteria, the spirochetes themselves did not bear or release factors with intrinsic chemotactic activity for monocytes or neutrophils. Thus, B. burgdorferi appears to be a strong inducer of chemokines which may, by the attraction and activation of phagocytic leukocytes, significantly contribute to inflammation and tissue damage observed in Lyme disease.

Borrelia burgdorferi Group↗
PubMed1997

An optimized PCR leads to rapid and highly sensitive detection of Borrelia burgdorferi in patients with Lyme borreliosis.

The present study aimed at developing an optimized PCR protocol fro the sensitive and specific detection of all three Borrelia burgdorferi genospecies pathogenic to humans in Lyme borreliosis patients. A rapid DNA extraction method using alkaline lysis was introduced and was found to be superior to other DNA extraction methods. Nested PCR was performed with primer sets targeting the plasmid-located ospA gene and a chromosomal gene segment encoding a 66-kDa protein (p66). In spiked synovial fluid (SF) fewer than three borreliae/sample were detected. The specificities of the amplicons were confirmed by Southern blot analysis with PCR-derived probes. Urine, cerebrospinal fluid (CSF), and SF specimens from 57 patients with Lyme borreliosis and from 58 controls were examined. In clinical samples the diagnostic sensitivity of PCR was 85% with SF samples, 79% with urine samples, and 91% with paired SF-urine samples from patients with Lyme arthritis and was 79% with CSF samples, 45% with urine samples, and 87% with paired CSF-urine specimens from neuroborreliosis patients. One patient each with neuroborreliosis and with Lyme arthritis had PCR-positive urine samples only. In 17% of all cases both primer sets yielded positive results, while the other patients were positive with only one primer set. Among these, more positive results were obtained with the p66 gene primer than with the ospA primer. The specificity exceeded 99%. We conclude that DNA from B. burgdorferi sensu lato species can sensitively and specifically be detected with the optimized PCR method described. At least two different primer sets should be used, and whenever possible, urine and CSF or SF should be analyzed in parallel to achieve maximum sensitivity of the test. This protocol, therefore, considerably enhances the diagnostic power of PCR in patients with B. burgdorferi infection.

Adolescent↗
PubMed1997

Cytokines derived from alveolar macrophages induce fever after bronchoscopy and bronchoalveolar lavage.

As much as one-third of patients develop fever and flu-like symptoms after fiberoptic bronchoscopy (FOB) and bronchoalveolar lavage (BAL) for yet unknown reasons. The aim of the present study was to investigate factors mediating these side effects. Fifty consecutive patients with various pulmonary diseases who underwent FOB without further interventions (n = 30) or combined with BAL (n = 20) were enrolled. Serum levels of the proinflammatory cytokines IL-1beta, IL-6, and TNF-alpha were determined directly prior to (t0), directly after (t1), and 6 h after (t2) the procedures by ELISA. In parallel, blood cultures were drawn at t2. At to and t1, generally only low cytokine concentrations could be detected. At t2, however, significant increases of cytokine levels were found. IL-6 and TNF-alpha were significantly higher in patients after BAL than in patients after FOB. Comparing patients who developed fever (n = 12) with those who did not (n = 38), irrespective of the endoscopic procedures performed, dramatic increases of all three cytokines were detected in febrile patients that were significantly higher than in patients without fever. In the FOB group only patients who received local anesthesia by prilocaine bolus injection into the airways via the working channel of the bronchoscope developed fever and increases of IL-6 and IL-beta, whereas patients anaesthetized by inhalation of a prilocaine aerosol remained afebrile and had slight IL-6 increases only. There was a highly significant correlation between IL-6 values at t2 and the number of BAL alveolar macrophages (r = 0.98). All blood cultures remained sterile. These results indicate that fever after FOB and BAL is induced by proinflammatory cytokines derived from alveolar macrophages activated by instillation of fluid into the airways.

Adult↗
PubMed1997

[The development of a finger joint phantom for the optical simulation of early inflammatory rheumatic changes].

In the field of rheumatology, conventional diagnostic methods permit the detection only of advanced stages of the disease, which is at odds with the current clinical demand for the early diagnosis of inflammatory rheumatic diseases. Prompted by current needs, we developed a finger joint phantom that enables the optical and geometrical simulation of an early stage of rheumatoid arthritis (RA). The results presented here form the experimental basis for an evaluation of new RA diagnostic systems based on near infrared light. The early stage of RA is characterised mainly by a vigorous proliferation of the synovial membrane and clouding of the synovial fluid. Using a double-integrating-sphere technique, the absorption and scattering coefficients (mua, mus') are experimentally determined for healthy and pathologically altered synovial fluid and capsule tissue. Using a variable mixture of Intralipid Indian ink and water as a scattering/absorption medium, the optical properties of skin, synovial fluid or capsule can be selected individually. Since the optical and geometrical properties of bone tissue remain constant in early-stage RA, a solid material is used for its simulation. Using the finger joint phantom described herein, the optical properties of joint regions can be adjusted specifically, enabling an evaluation of their effects on an optical signal--for example, during fluorography--and the investigation of these effects for diagnostically useful information. The experimental foundation for the development of a new optical system for the early diagnosis of RA has now been laid.

Arthritis, Rheumatoid↗
PubMed1997

A New Method for Database Searching and Clustering.

An iterative database searching method is introduced and applied to the design of a database clustering procedure. The search method virtually never produces false positive hits while determining meaningfully large sets of sequences related to the query. A novel set-theoretic database clustering algorithm exploits this feature and avoids a traditional, distance-based clustering step. This makes it fast and applicable to data-sets of the size of, e.g., the Swiss-Prot database. In practice we achieve unambiguous assignment of 80% of Swiss-Prot sequences to non-overlapping sequence clusters in an entirely automatic fashion.

Journal Article↗
PubMed1997

[Quality of life in relation to patient education regarding surgical procedures in primary breast carcinoma].

Breast conserving therapy is seen as a profit according to life quality. The patients have been subjected to the surgeon suggestions during decision-making about the primary therapy. The purpose of this study was to examine the relationship between the degree of preoperative information of breast cancer therapy and patients' choices of treatments in cases suited for breast conserving therapy. 138 recurrence free patients after breast conserving therapy (BCT) or mastectomies (ME) due to a breast cancer staged as pT1-2N0-1M0 and missing contraindication to BCT were interviewed using an observer checklist. The degrees of preoperative information, reasons for decision to mastectomy, though BCT was possible, were correlated with the postoperative life quality. Patients decided for BCT were averaging 56.0 + 12.3 years and significantly (p < 0.05) younger than patients decided for ME (60.4 + 10.5), whereas tumor size, nodal status and adjuvant therapies were comparable. The results indicate, that subjects' choice of treatment was unrelated to the amount of information. 87% (BET) respectively 78.3% (ME) patients evaluated, that preoperative information was enough (p = 0.19). The most frequent reasons for preference of mastectomy were the "perception that survival would be diminished if mastectomy was not done" (93.5%), "avoidance of radiotherapy" (60.9%) and "no partner" (34.8%). According to expectation the body image in the BCT-group (84.8%) was significantly (p = 0.0007) more positive than in the ME-group (58.9%). Nevertheless only 5 (10.9%) patients after ME have felt sorry for their earlier decision. There were no significant differences between the two groups with regard to partner- and sexual adjustment as well as physical well-being. Despite being fully informed of treatment possibilities and no medical contraindications to BCT nearly one third preferred mastectomy due to different reasons. When the patient was involved in the clinical decision-making process the mastectomy indicates not generally a loss of life quality, though nearly 40% are dissatisfied with their nude body image.

Adult↗
PubMed1996

A study of second-look laparoscopy after acute salpingitis.

Acute salpingitis (AS) has a major impact on the reproductive health of women. In this study second-look laparoscopy was assessed for its ability to predict reproductive function after AS. We questioned 158 women who had had a second-look laparoscopy with tubal dye insufflation after laparoscopically proven AS between September 1984 and August 1989. The answers of 69 women with at least two years of involuntary infertility were analyzed. The mean follow-up period was 76 months (range 53-108 months). Second-look laparoscopy revealed bilateral tubal occlusion in 21.7% (15/69). Bilateral tubal occlusion was found in 9.5% (2/21) after mild stage, 20% (4/20) after moderate stage and 32.1% (9/28) after severe stage AS. The rate of infertility during follow-up was 9.5% (stage I), 35% (stage II) and 39.9% (stage III). Eighty per cent (12/15) of women with proven bilateral tubal occlusion after treated AS had involuntary infertility, and 14.8% (8/54; P = 0.000001) of women with one or both tubes patent also had infertility. Specificity, sensitivity and positive predictive value for subsequent infertility were 85.2%, 80% and 84.1%, respectively. Pelvic adhesions (21/69) were strongly correlated with bilateral tubal occlusion (8/21; 38.1%; P = 0.029), a history of chronic pelvic pain (14/21; 66.7%; P = 0.00024), as well as failure to achieve an intrauterine pregnancy (10/21; 47.6%; P = 0.024). Recurrent pelvic infections occurred in 16% (12/69) and ectopic pregnancies in 7.3% (5/69). Operations for infertility and pelvic pain (excluding ectopic pregnancy), were carried out in 11.6% (8/69). We conclude that second-look laparoscopy after treated AS have accurate evaluation of reproductive function.

Acute Disease↗
PubMed1996

[Autoimmune diseases of the peripheral cornea. Immunopathology, clinical aspects and therapy].

Noninfectious ulceration of the peripheral cornea remains a major diagnostic and therapeutic challenge. The pathogenesis in most of these disorders is unclear, however, on the basis of systemic connective tissue diseases, autoimmune mechanisms are most likely involved. The peripheral cornea has distinct morphological and immunological characteristics that predispose for inflammatory reactions. Major differences exist regarding humoral and cellular components of the immune system. In the peripheral cornea there is more high-molecular IgM and initial complement component C1 than in the central cornea and may predispose for immune complex formation. The close contact to the conjunctival vasculature provides the basis necessary to generate an immune response. Langerhans cells and macrophages as important antigen presenting and processing cells are present in higher number in the peripheral cornea. Autoimmune diseases that affect the peripheral cornea include collagen vascular diseases and Mooren's ulcer. Although this association is obvious in advanced rheumatoid arthritis more subtle forms of polyarteritis nodosa or systemic lupus erythematosus require careful medical evaluation and workup. Ocular manifestations may present as the initial clinical signs and require careful workup in these potentially lethal disorders.

Antigen-Presenting Cells↗
PubMed1996

Potential infectious agents in the induction of arthritides.

In the multifactorial etiology of rheumatic diseases, infectious agents are regarded as the major environmental factors that may cause inflammatory arthritides in genetically susceptible hosts. Two not mutually exclusive pathogenetic pathways are hypothesized to explain the initiation and perpetuation of chronic arthritides by infectious agents: persistent infection and induction of immunopathology. In this review we focus on the role of infections in the etiopathogenesis of rheumatoid arthritis. Retroviruses and enteropathogenic bacteria continue to be the most intensively discussed candidates as possible etiologic factors of rheumatoid arthritis. Although there is ample indirect evidence for the involvement of infections in the pathogenesis of autoimmune disease, direct proof is still missing. There may be no single infectious trigger for rheumatoid arthritis, but multiple infectious agents that share antigenic motifs. The "reverse immunology" approach addresses this issue and is discussed in our outlook on future research directions.

Arthritis↗
PubMed1996

Infection with Bacillus cereus after close-range gunshot injuries.

Three patients were admitted with close-range gunshot wounds of the knee and lower leg, inflicted in all three cases through clothing. At admission, all of the patients were given antibiotics (cefuroxime and metronidazole) to prevent streptococcal and anaerobic infection. All of the patients developed severe tissue infection with Bacillus cereus within days of admission. In one case, the organism was also recovered from the blood. B. cereus is capable of causing severe infection after trauma and its ubiquity in the environment allows it easy access to gunshot wounds. Its potent production of beta-lactamase renders penicillins and cephalosporins predictably ineffective. The early administration of a non-beta-lactam drug (such as ciprofloxacin) should be considered in cases where Bacillus cereus is isolated from traumatic wounds.

Anti-Bacterial Agents↗
PubMed1996

Naloxone-reversible coma unrelated to opiate drugs.

A role for endogenous opioids in central nervous system disorders has often been proposed. A case report is presented of a 47-year-old male, medicated only with carbamazepine and lithium, who developed a precipitous alteration of consciousness (Glascow coma scale = 4). An extensive medical workup did not reveal an underlying cause. He exhibited a graded awakening with two intravenous doses of naloxone, which gradually reversed as the last naloxone dose was eliminated. Immunoassay and thin-layer chromatography of two urine samples (to evaluate the possibility of a medication error, alcohol ingestion, or illicit drug use) revealed only the presence of carbamazepine. A dysregulation of the endogenous opioid system is believed to underlie this episode.

Atrophy↗
PubMed1996

Beta-globin haplotype analysis suggests that a major source of Malagasy ancestry is derived from Bantu-speaking Negroids.

The origins of the inhabitants of Madagascar have not been fully resolved. Anthropological studies and preliminary genetic data point to two main sources of ancestry of the Malagasy, namely, Indonesian and African, with additional contributions from India and Arabia. The sickle-cell (beta s) mutation is found in populations of African and Indian origin. The frequency of the beta s-globin gene, derived from 1,425 Malagasy individuals, varies from 0 in some highland populations to .25 in some coastal populations. The beta s mutation is thought to have arisen at least five times, on the basis of the presence of five distinct beta s-associated haplotypes, each found in a separate geographic area. Twenty-five of the 35 Malagasy beta s haplotypes were of the typical "Bantu" type, 1 "Senegal" haplotype was found, and 2 rare or atypical haplotypes were observed; the remaining 7 haplotypes were consistent with the Bantu haplotype. The Bantu beta s mutation is thought to have been introduced into Madagascar by Bantu-speaking immigrants (colonists or slaves) from central or east Africa. The Senegal beta s mutation may have been introduced to the island via Portuguese naval explorers. This study provides the first definitive biological evidence that a major component of Malagasy ancestry is derived from African populations, in particular, Bantu-speaking Negroids. beta A haplotypes are also consistent with the claim for a significant African contribution to Malagasy ancestry but are also suggestive of Asian/Oceanic and Caucasoid admixture within the Malagasy population.

Africa↗
PubMed1996

[Sarcoid tumor of the breast].

We report on a 56 years old women with an enlarging breast mass in the region of an old scar due to a former diagnostic excision. Mammography and sonography were without value while MRT was suspicious for breast cancer. In the frozen section of the excised tissue a carcinoma was diagnosed and therefore a mastectomy performed. This diagnosis was in correct, instead a granulomatous process in the breast and the axillary lymph nodes took place. In respect to a pulmonary sarcoidosis and to laboratory results a true breast sarcoidosis may be supposed. It was also discussed whether it could be a lipogranulomatous pseudosarcoidosis.

Biopsy↗
PubMed1996

Parainfluenza-3-virus infection enhances allergic sensitization in the guinea-pig.

BACKGROUND: Viral respiratory tract infections have been previously considered to be associated with induction of allergic sensitization. OBJECTIVE AND METHODS: In order to investigate this relationship in an animal model, guinea-pigs were inoculated intranasally with Parainfluenza-3-(PI-3) virus (n = 16) or virus-free culture medium (controls, n = 12), sensitized at day 4 with inhaled ovalbumin (OA) and challenged 3 weeks later with inhaled OA using specific bronchial provocation testing with body plethysmographic measurement of compressed air (CA). Furthermore, specific anti-OA-IgG1-antibodies in serum before challenge were determined by enzyme linked immunosorbent assay (ELISA). For investigation of airway epithelium permeability horseradish peroxidase (HRP) was inhaled at day 4 after inoculation by six animals, and HRP serum concentrations were determined by a direct ELISA 30 min after inhalation. RESULTS: PI-3 infected animals were found to be significantly more sensitized to OA compared with controls, with higher CA values (P < 0.001) on specific bronchial provocation and with increased specific anti-OA-IgG1 titers. Serum-HRP concentrations were about 20 times higher in the infected animals compared with controls. PI-3 infected and sham-infected animals had comparable bronchial reactions on specific provocation with OA when sensitized systemically. CONCLUSIONS: We conclude that viral respiratory tract infection with PI-3 virus enhances inhalative allergic sensitization in the guinea-pig. Increased mucosal permeability to antigens may be an important pathophysiological mechanism.

Adjuvants, Immunologic↗