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Biomedical subjects

C Bucher

Publications and source records attributed to C Bucher.

At least 19 recordsLinked to original sources
PubMed2004

High-dose chemotherapy using BEAM for tumor debulking without stem cell support followed by early allogeneic reduced intensity conditioning transplantation to induce a graft-versus-lymphoma effect in patients with high risk or refractory lymphoma.

In patients with refractory lymphoma, we tested the hypothesis that high-dose chemotherapy (BEAM) without stem cell support followed by a reduced intensity (RIC) allogeneic transplant with fludarabine and 2 Gy TBI 28 days later results in tumor debulking and establishment of a graft vs lymphoma effect, with acceptable toxicity. In a pilot protocol we treated 10 patients, 22-62 (median 47) years of age with high-risk or refractory Hodgkin's or non-Hodgkin's lymphoma. Donors were HLA identical siblings (eight) or unrelated volunteers. None died during the neutropenic phase after BEAM which lasted up to the RIC HSCT. The duration of neutropenia was 31-43 (median 36) days. All patients engrafted and nine achieved CR. All developed acute GvHD (median grade III) and all patients at risk developed chronic GvHD. Three patients died of GvHD. One relapsed and six patients are in continuous CR 10-32 (median 15) months after HSCT. This approach appears feasible and results in a high response rate. Neutropenia duration is of concern. It remains to be tested whether separation of debulking chemotherapy and induction of allogeneic effects confers an advantage.

Adolescent↗
PubMed2003

Clinical and angiographic outcome of patients with mild coronary lesions treated with balloon angioplasty or coronary stenting. Implications for mechanical plaque sealing.

AIMS: To investigate the clinical and angiographic outcome of patients with mild coronary lesions treated with balloon angioplasty or coronary stenting (coronary plaque sealing, i.e. dilatation of angiographically non-significant lesions) compared to moderate and severe stenoses. METHODS AND RESULTS: Patients with chronic stable angina and a single de novo lesion in a native coronary vessel scheduled to undergo percutaneous coronary intervention (PCI) were selected from 14 different studies. Off-line analysis of angiographic outcomes was assessed in all patients using identical and standardised methods of data acquisition, analysis and definitions. Clinical endpoints were adjudicated by independent clinical events committees. All quantitative coronary angiographic (QCA) analyses were performed in the same core laboratory. Stenosis severity prior to PCI was categorised into three groups: <50% diameter stenosis (DS), 50-99%DS and >99%DS pre. A total of 3812 patients were included in this study; 1484 patients (39%) were successfully treated with balloon angioplasty (BA) only and stented angioplasty was performed in 2328 patients (61%).One-year mortality and rate of non-fatal myocardial infarction (MI) (Kaplan-Meier) did not differ between BA and stented angioplasty for any of the stenosis severity categories. Following BA, the combined event rate (death and non-fatal MI) was 4.8, 4.6 and 0% in the <50, 50-99 and >99%DS categories, respectively. Following stented angioplasty, the combined event rate was 3.1, 4.4 and 4.8% in the same categories. The need for repeat revascularisation corrected for stenosis severity in the Cox proportional-hazards regression model was reduced by 20% after stented angioplasty (hazard ratio (HR) 0.80, 95%CI 0.69-0.93). CONCLUSION: The concept of plaque sealing is appealing from the theoretical point of view. However, with current technology, plaque sealing cannot prevent death and future non-fatal MIs in the long-term because 1-year event rates after PCI of non-significant stenoses remain unacceptably elevated when compared with the estimated 1-year probability of a non-fatal MI in lesions with a <50%DS. Moreover, major adverse cardiac events at 1-year after PCI are not directly related to the degree of pre-procedural stenosis severity.

Angina Pectoris↗
PubMed2001

Patterns of her-2/neu amplification and overexpression in primary and metastatic breast cancer.

BACKGROUND: Only 25% of patients with HER-2/neu-positive metastatic breast tumors respond favorably to trastuzamab (Herceptin) treatment. We hypothesized that a high failure rate of patients on trastuzamab could result if some of the metastases were HER-2 negative and these metastases ultimately determine the course of the disease. METHODS: We used tissue microarrays (TMAs) containing four samples each from 196 lymph node-negative primary tumors, 196 lymph node-positive primary tumors, and three different lymph node metastases from each lymph node-positive tumor to estimate HER-2 gene amplification by fluorescence in situ hybridization (FISH) and Her-2 protein overexpression by immunohistochemistry (IHC). RESULTS: FISH and IHC analyses gave the same result with respect to HER-2 status for 93.7% of the tissues contained in the TMAs. Tissue samples were, therefore, considered to be HER-2 positive if they were positive for either HER-2 DNA amplification or Her-2 protein expression and HER-2 negative if both FISH and IHC gave a negative result. The HER-2 status of lymph node-positive primary tumors was maintained in the majority of their metastases. For HER-2-positive primary tumors, 77% (95% confidence interval [CI] = 59% to 90%) had entirely HER-2-positive metastases, 6.5% (95% CI = 8% to 21%) had entirely HER-2-negative metastases, and 16.3% (95% CI = 5% to 34%) had a mixture of HER-2-positive and HER-2-negative metastases. For HER-2-negative primary tumors, 95% (95% CI = 88% to 98%) had metastases that were entirely negative for HER-2. CONCLUSIONS: Our data suggest that differences in HER-2 expression between primary tumors and their lymph node metastases cannot explain the high fraction of nonresponders to trastuzamab therapy.

Antibodies, Monoclonal↗
PubMed2001

Tissue microarrays for rapid linking of molecular changes to clinical endpoints.

Advances in genomics and proteomics are dramatically increasing the need to evaluate large numbers of molecular targets for their diagnostic, predictive or prognostic value in clinical oncology. Conventional molecular pathology techniques are often tedious, time-consuming, and require a lot of tissue, thereby limiting both the number of tissues and the number of targets that can be evaluated. Here, we demonstrate the power of our recently described tissue microarray (TMA) technology in analyzing prognostic markers in a series of 553 breast carcinomas. Four independent TMAs were constructed by acquiring 0.6 mm biopsies from one central and from three peripheral regions of each of the formalin-fixed paraffin embedded tumors. Immunostaining of TMA sections and conventional "large" sections were performed for two well- established prognostic markers, estrogen receptor (ER) and progesterone receptor (PR), as well as for p53, another frequently examined protein for which the data on prognostic utility in breast cancer are less unequivocal. Compared with conventional large section analysis, a single sample from each tumor identified about 95% of the information for ER, 75 to 81% for PR, and 70 to 74% for p53. However, all 12 TMA analyses (three antibodies on four different arrays) yielded as significant or more significant associations with tumor-specific survival than large section analyses (p < 0.0015 for each of the 12 comparisons). A single sample from each tumor was sufficient to identify associations between molecular alterations and clinical outcome. It is concluded that, contrary to expectations, tissue heterogeneity did not negatively influence the predictive power of the TMA results. TMA technology will be of substantial value in rapidly translating genomic and proteomics information to clinical applications.

Adult↗
PubMed2001

[Therapy of allergic bronchial asthma].

Asthma and atopy are strongly related conditions. The presence of specific IgE to perennial (arthropods, animal dander and other), seasonal (pollens, certain fungal spores) and occupational allergens is associated with the occurrence of asthmatic symptoms. Current therapy is based on combining three principles: Avoidance of trigger factors and of allergen exposure, drug therapy, and specific immunotherapy. Feasability and effectiveness of allergen avoidance (particularly of perennial allergens) have been proven. However, these measures must often be supplemented with drug therapy. Several classes of drugs are nowadays available for treatment of asthmatic symptoms and, most importantly, for control of the bronchial inflammatory process which underlies atopic asthma. Specific immunotherapy is a good treatment option in allergy to pollens, but its use is controversial in allergy to house dust mites and other perennial allergens. Finally, it should be kept in mind that the successful longterm management of patients with atopic asthma depends highly on the compliance of patients.

Anti-Asthmatic Agents↗
PubMed2001

Allergy to bumblebee venom.

Allergy to bumblebee venom is a rare form of Hymenoptera venom allergy. Because bumblebees are increasingly used for the pollination of greenhouse plants, the prevalence of this Hymenoptera allergy has increased during the past decade. The clinical presentation, diagnosis and therapy of bumblebee venom allergy are similar to other Hymenoptera venom allergies. There is a significant immunological cross-reactivity between bumblebee and honeybee venom. It has been claimed that immunotherapy with honeybee venom can protect patients with bumblebee venom allergy. This concept, however, has been called into question after the finding of bumblebee venom-specific IgE lacking cross-reactivity to honeybee venom, and three cases of bumblebee venom-allergic patients in whom immunotherapy with honeybee venom was unsuccessful. Immunotherapy with pure bumblebee venom has been shown to be effective and safe, and is currently the treatment of choice in individuals who cannot avoid contact with bumblebees. Immunotherapy with honeybee venom, however, should be considered in patients with severe reactions to bumblebee stings and concurrent sensitization to honeybee venom.

Adult↗
PubMed2000

[Ant venoms: a rare cause of allergic reactions in Switzerland].

In Switzerland, unlike other countries, allergic reactions to ants are a rare phenomenon when compared to the well known allergies to bee and wasp venom. In this report we present a series of case reports and a review of the different types of allergy to ants. Due to increased travel and heterogeneity of the population, we have observed several patients with sensitisation or allergy to the venom of imported fire ants (Solenopsis), a species of ant found in the Americas. Furthermore, allergic reactions to bites of the mound-building wood ant (Formica rufa), whose habitat is Central and Northern Europe, have been documented. Whereas reactions to fire ants can be life-threatening, reactions to mound-building wood ants have led to marked local reactions and in 2 cases to dyspnoea and wheezing. These reactions could be due either to primary sensitisation to ant venom or cross-reactivity in the presence of an allergy to wasp venom. Evaluation of patients presenting with a potential ant venom allergy includes a detailed personal history, skin testing and determination of specific IgE. However, to date only extracts from fire ants are commercially available for diagnostic tests. In the light of our observations we assume cross-reactivity between the venoms of fire ants and mound-building wood ants, and it therefore seems appropriate to use fire ant diagnostics in determining sensitisation to mound-building wood ants. In patients with severe fire ant-venom allergy we recommend desensitisation by immunotherapy, whereas in patients presenting with minor allergic reactions, e.g. after bites by mound-building wood ants, we provide the patients with emergency medication. Since current knowledge of ant allergies in Europe is limited, further studies are warranted.

Animals↗
PubMed2000

Novel synthesis of hybrid calixphyrin macrocycles

The reaction of benzaldehyde with excess pyrrole at room temperature in the absence of solvent affords a mixture of meso-substituted polypyrranes species. After separation by column chromatography, these may be used to prepare a range of calix[4]phyrin macrocycles by condensation with acetone under conditions of acid catalysis.

Journal Article↗
PubMed2000

Detecting activation of ribosomal protein S6 kinase by complementary DNA and tissue microarray analysis.

BACKGROUND: Studies by comparative genomic hybridization (CGH) have shown that chromosomal region 17q23 is amplified in up to 20% of primary breast cancers. We used microarray analyses to measure the expression levels of genes in this region and to explore their prognostic importance. METHODS: A microarray that contained 4209 complementary DNA (cDNA) clones was used to identify genes that are overexpressed in the MCF-7 breast cancer cell line as compared with normal mammary tissue. Fluorescence in situ hybridization was used to analyze the copy number of one overexpressed gene, ribosomal protein S6 kinase (S6K), and to localize it to the 17q23 region. Northern and western blot analyses were used to measure S6K gene and protein expression, and an enzymatic assay was used to measure S6K activity. Tumor tissue microarray analysis was used to study amplification of S6K and the HER-2 oncogene, another 17q-linked gene, and the relationship between amplification and prognosis was analyzed. The Kaplan-Meier method was used for data analysis, and the log-rank test was used for statistical analysis. All P values are two-sided. RESULTS: S6K was amplified and highly overexpressed in MCF-7 cells relative to normal mammary epithelium, and protein expression and enzyme activity were increased. S6K was amplified in 59 (8.8%) of 668 primary breast tumors, and a statistically significant association between amplification and poor prognosis (P =.0021) was observed. Amplification of both S6K and HER-2 implied particularly poor survival (P =.0001). CONCLUSIONS: The combination of CGH information with cDNA and tissue microarray analyses can be used to identify amplified and overexpressed genes and to evaluate the clinical implications of such genes and genomic rearrangements. S6K is likely to be one of the genes at 17q23 that is amplified during oncogenesis and may adversely affect the prognosis of patients with this amplification.

Blotting, Northern↗
PubMed2000

[Mastocytosis: an important differential diagnosis in anaphylactoid reaction to Hymenoptera sting. A case report and overview of clinical aspects, diagnosis and current therapy of mastocytosis].

A 77-year old farmer presented with a history of three severe anaphylactoid reactions after hymenoptera stings for the last three years. No sensitisation to hymenoptera venoms could be shown on allergological work-up. The serum level of tryptase however was clearly elevated (37.1 micrograms/l; normal value: < 13.5 micrograms/l). The diagnosis of systemic mastocytosis could be confirmed by bone marrow biopsy. Patients with mastocytosis are at increased risk of anaphylactic/anaphylactoid reactions. They should be educated how to avoid trigger factors and they should always carry an emergency kit (H1 blocker, corticosteroid, adrenalin) and a "mastocytosis pass" with them. Venom immunotherapy is indicated in patients with proven hymenoptera allergy. Selected patients at very high risk of anaphylactic reactions may need a continuous prophylactic medication with H1 and H2 blocker and eventually a cyclooxygenase inhibitor.

Aged↗
PubMed2000

Double sensitization to honeybee and wasp venom: immunotherapy with one or with both venoms? Value of FEIA inhibition for the identification of the cross-reacting ige antibodies in double-sensitized patients to honeybee and wasp venom.

BACKGROUND: Double sensitization to honeybee (Apis mellifera) and wasp venom (Vespula spp.) as determined by skin test and measurement of specific IgE is common in hymenoptera sting allergy. Double-sensitized patients have either distinct antibodies for each venom or cross-reacting antibodies that recognize similar or identical epitopes in both venoms. Unfortunately, patients often fail to identify the stinging insect which makes it difficult to distinguish cross-reactors from non cross-reactors. However, for economic reasons as well as for the benefit of the patients, it would be useful to identify complete cross-reactors. METHODS: In this study we investigated 24 double-sensitized patients who were candidates for venom immunotherapy. Homologous and heterologous FEIA inhibition was carried out with honeybee (Apis mellifera) and wasp venom (Vespula spp.) preparations from two different providers. The inhibitor concentrations were ranging from 0 to 100 microg protein/ml. RESULTS: Sera of 4 patients were completely cross-reacting for one venom (3 honeybee, 1 wasp), 8 patients were partially cross-reacting and 10 patients were not cross-reacting. Two patients were excluded from the study due to insufficient homologous inhibition. Data from specific IgE measurements, skin test, and clinical history were not useful for the identification of cross-reacting patients. CONCLUSION: FEIA inhibition is easy to perform and useful for the identification of patients with complete cross-reactivity. In these patients immunotherapy might be restricted to one venom which is beneficial for the patient and cost-effective.

Adolescent↗
PubMed1999

Relative risk of malignant tumors in analgesic abusers. Effects of long-term intake of aspirin.

BACKGROUND: Nonsteroidal anti-inflammatory drugs (NSAID) e.g. aspirin, indomethacin are reported in epidemiological and experimental studies to reduce the risk for colo-rectal cancer and potentially other malignant tumors. METHODS: We examined the effect of NSAIDs on tumor prevalence in abusers of mixed analgesics containing aspirin, phenacetine, caffeine or codein. 618 analgesic abusers who were autopsied between 1968-1983 were compared with a control group without evidence of analgesic abuse matched for sex, age and year autopsy was performed. RESULTS AND CONCLUSIONS: Abusers were found to have an overall risk of 0.40 fold of having developed a malignancy as compared with the controls. Excluding patients with urinary tract tumors which are increased in analgesic abusers the risk was further decreased to 0.28. No statistically significant effect was found for patients with prostate cancer. The results encourage prospective control studies in high risk patients.

Aged↗