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Biomedical subjects

H Huber

Publications and source records attributed to H Huber.

At least 37 records · Page 2Linked to original sources
PubMed2001

New drugs in the palliative chemotherapy of advanced non-small-cell lung cancer.

In inoperable advanced non-small-cell lung cancer (NSCLC), palliative chemotherapy is established and aims at palliation of symptoms, improvement of quality of life and prolongation of survival. In the last years, several new drugs with enhanced activity towards NSCLC and improved toxicity profile have been characterised, for example vinorelbine, gemcitabine, paclitaxel and docetaxel. Data from randomised trials suggest that regimens containing new drugs are more active than older combinations. Platin-based combinations of either vinorelbine, gemcitabine or paclitaxel have resulted in better outcome than cisplatin alone and new drugs in combination with platins are more active than the corresponding single agent. Non-platin-based combinations must be considered investigational until their non-inferiority to platin-based protocols has been proven in randomised trials on large patient populations. Patients with good performance status and adequate organ function should receive platin-based chemotherapy that includes the new drugs (vinorelbine, gemcitabine, paclitaxel or docetaxel). New drugs without platins are suitable for elderly patients and patients with poor performance status. Second-line chemotherapy prolongs survival in selected patients and should be particularly offered to patients with good performance status.

Antineoplastic Agents↗
PubMed2001

[The insufficiency fracture of the sacrum. An often unrecognized cause of low back pain: results of bone scanning in a major hospital].

AIM: The insufficiency fracture of the sacrum is often radiographically occult. Bone scintigraphy is a method of reference for the diagnosis; the results have been analysed retrospectively. METHODS: Bone scintigraphy was done on patients who, predominantly after minor trauma, suffered from lower back pain and whose radiographic findings were negative. RESULTS: During a 24 month period, a sacral insufficiency fracture was diagnosed in 102 patients. H-shaped hyperfixation of the tracer--described as typical--was present in only 19.6% of the cases. Tracer accumulation was found as follows: located uni/bilateral in the sacral wings (32.4%/6.9%), horizontal (27.4%) and half H-shaped (13.7%). In 85% of the cases there were further fractures with main localisations in the public bone, in the spine and the ribs. CONCLUSION: The insufficiency fracture of the sacrum as cause of lower back pain is not uncommon, especially in postmenopausal women with risk factors. Bone scintigraphy is not only an adequate procedure for the detection of often radiographically occult sacral fractures, but also an easy method to reveal the often concomitant fractures.

Fractures, Stress↗
PubMed2000

Activation of retinoic acid receptor alpha is sufficient for full induction of retinoid responses in SK-BR-3 and T47D human breast cancer cells.

Retinoid signaling via retinoic acid (RA) and retinoid X receptors (RARs and RXRs) regulates mammary epithelial cell growth and differentiation. Loss of RAR-beta might represent an early event during breast carcinogenesis. Higher differentiated, estrogen-dependent, estrogen receptor (ER)-positive (ER+) mammary carcinoma cells have been found to contain relatively high levels of RAR-alpha and to be responsive to retinoids, whereas most undifferentiated, estrogen-independent, ER-negative (ER-) cells are characterized by low RAR-alpha expression and by retinoid resistance. In contrast, RAR-gamma is detectable at equal levels in both ER+ and ER- cells. In the present investigation, we directly examined the relative contribution of the distinct retinoid receptors to the retinoid response of breast cancer cells by comparing the effects of low concentrations of specific retinoids, which selectively activate individual receptor subtypes, on growth, cell cycle distribution, apoptosis, and on the autoregulation of RAR-alpha and RAR-gamma in ER- SK-BR-3 and ER+ T47D breast cancer cells. In vitro growth activity was determined by using a colorimetric cell viability assay and analysis of cell cycle distribution, and apoptosis was performed by flow cytometry of propidium iodide-stained or fluorescent Annexin V-labeled cells, respectively, whereas expression of RAR-alpha and RAR-gamma was determined by Northern blotting. Both cell lines are retinoid sensitive and express high amounts of RAR-alpha, RAR-gamma, and RXR-alpha. RAR-alpha-selective compounds (AM80 and AM580) inhibit cell growth, induce G1 arrest, stimulate apoptosis, and up-regulate RAR-alpha and RAR-gamma mRNA as efficiently as RAR/RXR-pan-reactive (9-cis RA) and RAR-pan-reactive retinoids (all-trans RA, TTNPB). Remarkably, an RAR-alpha antagonist (Ro 41-5253) not only blocks the RAR-alpha-selective agonists but also the pan-reactive compounds. In contrast, RAR-13-selective (CD417), RAR-gamma-selective (CD437/AHPN), and RXR-alpha-selective (Ro 25-7386) retinoids exert no effects on the examined parameters. Thus, our results support the idea that RAR-alpha is the crucial receptor mediating the biological effects during retinoid signaling in both ER- SK-BR-3 and ER+ T47D human breast cancer cells.

Antineoplastic Agents↗
PubMed2000

Adenylylsulfate reductases from archaea and bacteria are 1:1 alphabeta-heterodimeric iron-sulfur flavoenzymes--high similarity of molecular properties emphasizes their central role in sulfur metabolism.

Highly active adenylylsulfate (APS) reductase was isolated under N(2)/H(2) from sulfate-reducing and sulfide-oxidizing bacteria and archaea. It was a 1:1 alphabeta-heterodimer of molecular mass approximately 95 kDa, and two subunits (alpha approximately 75, beta approximately 20 kDa). The specific activity was 11-14 micromol (min mg)(-1); cofactor analysis revealed 0.96+/-0.05 FAD, 7.5+/-0.1 Fe and 7.9+/-0.25 S(2-). The photochemically reduced enzyme had a multiline EPR spectrum resulting from two interacting [4Fe-4S] centers. The properties of the different APS reductases were remarkably similar, although the enzyme is involved in different metabolic pathways and was isolated from phylogenetically far separated organisms. A structural model is proposed, with FAD bound to the alpha-subunit, and two [4Fe-4S] centers located in close proximity on the beta-subunit.

Adenosine Monophosphate↗
PubMed2000

Deletion of 13q14 remains an independent adverse prognostic variable in multiple myeloma despite its frequent detection by interphase fluorescence in situ hybridization.

Interphase fluorescence in situ hybridization (FISH) studies of chromosomal region 13q14 were performed to investigate the incidence and clinical importance of deletions in multiple myeloma (MM). Monoallelic deletions of the retinoblastoma-1 (rb-1) gene and the D13S319 locus were observed in 48 of 104 patients (46.2%) and in 28 of 72 (38.9%) patients, respectively, with newly diagnosed MM. FISH studies found that 13q14 was deleted in all 17 patients with karyotypic evidence of monosomy 13 or deletion of 13q but also in 9 of 19 patients with apparently normal karyotypes. Patients with a 13q14 deletion were more likely to have stage III disease (P =.022), higher serum levels of beta(2)-microglobulin (P =.059), and a higher percentage of bone marrow plasma cells (P =.085) than patients with a normal 13q14 status on FISH analysis. In patients with a deletion of 13q14, myeloma cell proliferation (Ki-67) was markedly increased (22.0% +/- 6.9% compared with 15.6% +/- 8.2% in patients without the deletion; P =.0008). Evaluation of bromodeoxyuridine incorporation in 5 patients revealed that both rb-1-deleted and rb-1-normal MM subpopulations were proliferative. The presence of a 13q14 deletion on FISH analysis was associated with a significantly lower rate of response to conventional-dose chemotherapy (40.8% compared with 78. 6%; P =.009) and a shorter overall survival (24.2 months compared with > 60 months; P <.005) than in patients without the deletion. Multivariate analysis of prognostic factors confirmed the independent predictive value of 13q14 deletions for shortened survival. In conclusion, deletions of 13q14 are frequently detected by interphase FISH in patients with newly diagnosed MM, correlate with increased proliferative activity, and represent an independent adverse prognostic feature in MM. (Blood. 2000;95:1925-1930)

Adult↗
PubMed2000

Two year follow-up of a garbage collector with allergic bronchopulmonary aspergillosis (ABPA).

BACKGROUND: Separate collection of biodegradable garbage and recyclable waste is expected to become mandatory in some western countries. A growing number of persons engaged in garbage collection and separation might become endangered by high loads of bacteria and fungi. Case history and examination A 29 year old garbage collector involved in emptying so-called biological garbage complained of dyspnea, fever, and flu-like symptoms during work beginning in the summer of 1992. Chest x-ray showed streaky shadows near both hili reaching into the upper regions. IgE- and IgG-antibodies (CAP, Pharmacia, Sweden) were strongly positive for Aspergillus fumigatus with 90.5 kU/L and 186%, respectively. Total-IgE was also strongly elevated with 5430 kU/L. Bronchial challenge testing with commercially available Aspergillus fumigatus extract resulted in an immediate-type asthmatic reaction. Two years later he was still symptomatic and antibodies persisted at lower levels. CONCLUSIONS: Our diagnosis was allergic bronchopulmonary aspergillosis (ABPA) including asthmatic responses as well as hypersensitivity pneumonitis (extrinsic allergic alveolitis) due to exposure to moldy household waste. A growing number of persons engaged in garbage collection and handling are exposed and at risk to develop sensitization to fungi due to exposure to dust of biodegradable waste. Further studies are necessary to show if separate collection of biodegradable waste increases the health risks due to exposure to bacteria and fungi in comparison to waste collection without separation.

Adult↗
PubMed2000

Influence of ischemic time on hyperacute xenograft rejection of pig hearts in a working heart perfusion model with human blood.

In xenotransplantation long ischemic time of grafts is supposed to have a marked influence on hyperacute rejection (HXR). We investigated the influence of different cold ischemic times on HXR of ex vivo "working pig hearts" perfused with human blood. Xenoreactive natural antibodies (XNAb) as a trigger of HXR were eliminated by Ig-Therasorb immunoadsorption (IA). Explanted Landrace pig hearts of group G1 and group G3 (with additional IA) underwent 4 h of cold ischemia prior to xenoperfusion. Control groups G2 and G4 (with IA) were kept ischemic for only 46.6 +/- 15.8 and 51.2 +/- 4.2 min, respectively. Ischemic time prolonged the perfusion time in our working heart model (G1: 356 +/- 46.1 min; G2: 125 +/- 31 min; P < 0.05). IA had no additional impact on perfusion time but was effective by itself. The heart weight increased fourfold more in G2 as compared to the other groups. IA without ischemia significantly improved cardiac output in G4 (G3: 198.8 +/- 15.4 mL/min; G4: 338.5 +/- 16.0 mL/min). Coronary flow in G2 was significantly lower than in G1 (G1: 157.9 +/- 9.15 mL/min; G2: 59.4 +/- 20.1 mL/min). Histological signs of HXR (light and electron microscopy) could be found in G2 in contrast to the other groups. Parameters of serological damage showed a minimum in G4 and the maximum in G2. In G1 XNAb were nearly equally eliminated immediately after the start of xenoperfusion as in IA groups G4 and G3. Four hours of ischemic time showed beneficial effects in preventing HXR, possibly caused by changes of the endothelial cell surface (for example, glycosylation or loss of alpha1-3Gal epitopes with a hapten effect).

Acute Disease↗
PubMed2000

Aneuploidy of chromosome 7 can be detected in invasive lung cancer and associated premalignant lesions of the lung by fluorescence in situ hybridisation.

In the present study the chromosomal status of seven invasive non small cell lung cancer specimens and associated premalignant lesions was investigated. By fluorescence in situ hybridisation (FISH) with centromere specific probes, an increase in the percentage of aneuploid cells from pre-invasive to invasive lesions could be demonstrated (mean 8.5 and 59%, respectively, for chromosome 7). Furthermore, mean chromosome copy numbers were higher in invasive carcinomas as compared to premalignant lesions, indicating polyploidization during tumor development. Increasing evidence suggests that aberrations of chromosome 7 occur early in the development of lung cancer. Whether these aberrations can be used as a biomarker for future neoplastic progression remains to be determined.

Aneuploidy↗
PubMed2000

Respiration of arsenate and selenate by hyperthermophilic archaea.

A novel, strictly anaerobic, hyperthermophilic, facultative organotrophic archaeon was isolated from a hot spring at Pisciarelli Solfatara, Naples, Italy. The rod-shaped cells grew chemolithoautotrophically with carbon dioxide as carbon source, hydrogen as electron donor and arsenate, thiosulfate or elemental sulfur as electron acceptor. H2S was formed from sulfur or thiosulfate, arsenite from arsenate. Organotrophically, the new isolate grew optimally in the presence of an inorganic electron acceptor like sulfur, selenate or arsenate. Cultures, grown on arsenate and thiosulfate or arsenate and L-cysteine, precipitated realgar (As2S2). During growth on selenate, elemental selenium was produced. The G+C content of the DNA was 58.3 mol%. Due to 16S rRNA gene sequence analysis combined with physiological and morphological criteria, the new isolate belongs to the Thermoproteales order. It represents a new species within the genus Pyrobaculum, the type species of which we name Pyrobaculum arsenaticum (type strain PZ6*, DSM 13514, ATCC 700994). Comparative studies with different Pyrobaculum-species showed, that Pyrobaculum aerophilum was also able to grow organotrophically under anaerobic culture conditions in the presence of arsenate, selenate and selenite. During growth on selenite, elemental selenium was formed as final product. In contrast to P. arsenaticum, P. aerophilum could use selenate or arsenate for lithoautotrophic growth with carbon dioxide and hydrogen.

Anaerobiosis↗
PubMed2000

Vinorelbine-gemcitabine in advanced non-small-cell lung cancer (NSCLC): an AASLC phase II trial. Austrian Association for the Study of Lung Cancer.

PURPOSE: The purpose of the present phase 11 trial was to determine the efficacy and toxicity of vinorelbine-gemcitabine in patients with advanced non-small-cell lung cancer (NSCLC). PATIENTS AND METHODS: From December 1997 to February 1999, 78 chemotherapy-naive patients (median age 60 years, Karnofsky performance status of 100, 90, 80 and 70 present in 5%, 41%, 36% and 18% of the patients, respectively) with stage IIIB (17%) or IV (83%) NSCLC (65% adenocarcinomas, 22% squamous-cell carcinomas, 10% large-cell carcinomas, 3% mixed-cell carcinomas) received 25 mg/m2 vinorelbine and 1200 mg/m2 gemcitabine on days 1, 8 and 15 of a four-week cycle. RESULTS: In an intent-to-treat analysis, partial responses were seen in 19% of the patients. The median duration of response was 4.4 months. The median survival time was seven months and the one-year survival rate was 32%. Myelosuppression was the main side effect with WHO grade 3/4 neutropenia and thrombocytopenia in 35% and 11% of the patients, respectively. Other side effects were usually mild to moderate. CONCLUSIONS: Vinorelbine-gemcitabine is active, well tolerated and easy to administer on an outpatient basis in advanced NSCLC. Thus a randomized comparison of this combination with platinum-based protocols is warranted in patients with advanced NSCLC.

Adult↗
PubMed2000

Deletions of chromosome 13q in monoclonal gammopathy of undetermined significance.

Since deletion of chromosome 13q is a clinically relevant feature in multiple myeloma (MM), we analyzed bone marrow plasma cells from 29 patients with monoclonal gammopathy of undetermined significance (MGUS) to investigate the chromosome 13 status in MGUS. Studies were performed by interphase fluorescence in situ hybridization (FISH) with a panel of 13q14-specific probes (RB1, D13S319, D13S25, D13S31). Plasma cells with a deletion of at least one of the 13q14 loci were detected in 13 patients (44.8%) with MGUS. In five patients (17.2%), deletions of all four 13q14-specific probes were observed, and the additional deletion of a 13q telomeric region (D13S327) suggested loss of the entire 13q arm or monosomy 13. Loss of 13q14 was observed to be monoallelic and to occur in 11.0 to 35.0% of plasma cells (cut-off levels for a deletion <10% with all probes). Nine of 17 patients (52.9%) with MM progressing from a pre-existing MGUS had evidence for a deletion of 13q14 as determined by FISH with the RB1 probe. These results suggest that deletion of 13q14 is an early event in the development of monoclonal gammopathies, but its role for the eventual progression to MM remains to be determined prospectively.

Adult↗
PubMed2000

Multiple myeloma with deletion of chromosome 13q is characterized by increased bone marrow neovascularization.

Anti-angiogenesis therapy with thalidomide has been reported to have marked activity in multiple myeloma (MM). As cytogenetics is an independent prognostic factor in MM, we analysed bone marrow (BM) angiogenesis and cytogenetic abnormalities in 34 patients with active MM. BM microvessel density (MVD), as determined by staining with anti-CD34, was significantly higher in MM (MVD: 221 +/- 94 per mm2) than in controls (80 +/- 36; P < 0.0001). In patients with the presence of at least one unfavourable cytogenetic abnormality (deletion of 13q14, deletion of 17p13, aberrations of 11q), a significantly increased BM MVD was observed (254 +/- 93 vs. 160 +/- 60 in patients with absence of these abnormalities; P = 0.0035). Further analyses indicated that increased BM MVD was significantly correlated with deletion of 13q14 (259 +/- 96 vs. 188 +/- 80; P = 0. 026), but not with other cytogenetic, clinical and laboratory MM parameters. We conclude that BM neovascularization is particularly high in MM with deletion of 13q14, which provides a rationale for use of anti-angiogenic strategies in the treatment of MM with high-risk cytogenetics.

Adult↗
PubMed2000

Oxygen detoxification in the strict anaerobic archaeon Archaeoglobus fulgidus: superoxide scavenging by neelaredoxin.

Archaeoglobus fulgidus is a hyperthermophilic sulphate-reducing archaeon. It has an optimum growth temperature of 83 degrees C and is described as a strict anaerobe. Its genome lacks any homologue of canonical superoxide (O2.-) dismutases. In this work, we show that neelaredoxin (Nlr) is the main O2.- scavenger in A. fulgidus, by studying both the wild-type and recombinant proteins. Nlr is a 125-amino-acid blue-coloured protein containing a single iron atom/molecule, which in the oxidized state is high spin ferric. This iron centre has a reduction potential of +230 mV at pH 7.0. Nitroblue tetrazolium-stained gel assays of cell-soluble extracts show that Nlr is the main protein from A. fulgidus which is reactive towards O2.-. Furthermore, it is shown that Nlr is able to both reduce and dismutate O2.-, thus having a bifunctional reactivity towards O2.-. Kinetic and spectroscopic studies indicate that Nlr's superoxide reductase activity may allow the cell to eliminate O2.- quickly in a NAD(P)H-dependent pathway. On the other hand, Nlr's superoxide dismutation activity will allow the cell to detoxify O2.- independently of the cell redox status. Its superoxide dismutase activity was estimated to be 59 U mg-1 by the xanthine/xanthine oxidase assay at 25 degrees C. Pulse radiolysis studies with the isolated and reduced Nlr proved unambiguously that it has superoxide dismutase activity; at pH 7.1 and 83 degrees C, the rate constant is 5 x 106 M-1 s-1. Besides the superoxide dismutase activity, soluble cell extracts of A. fulgidus also exhibit catalase and NAD(P)H/oxygen oxidoreductase activities. By putting these findings together with the entire genomic data available, a possible oxygen detoxification mechanism in A. fulgidus is discussed.

Amino Acid Sequence↗
PubMed2000

Malignant cell detection by fluorescence in situ hybridization (FISH) in effusions from patients with carcinoma.

Cytological diagnosis of malignant cells in effusions is hampered by difficulties in the differentiation from reactive mesothelial cells. Because interphase cytogenetics by fluorescence in situ hybridization (FISH) might complement cytological evaluation, we determined the power of tumor cell detection using FISH and cytology in 201 effusions from patients with advanced cancer. Furthermore, 9 primary breast tumors were FISH-karyotyped, and chromosomal aberrations were compared with those of corresponding metastatic effusion cells. By using centromeric probes representing chromosomes 7, 8, 11, 12, 17, and 18, a rate of malignancy-associated aneusomy combined for the 6 chromosomes was detected in an overall of 44.8% of effusion specimens (range, 31.8% to 39.3% for the individual chromosome), comparable to cytology (43.3%). The combination of just 2 FISH probes (namely, representing chromosome pairs 8/11 and 8/17) was almost equally efficient in the identification of aneusomy. Approximately one fourth of the cytologically negative effusions were FISH positive and vice versa. From the initially FISH-negative effusions, 18.9% could be subsequently classified positive with dual-color FISH by visualization of intranuclear chromosomal complexity in rare aneuploid cells. Thus, "overall FISH analysis," including dual-color evaluation, identified tumor cells in significantly more effusions (55.2%, P = .001) than conventional cytology, implying greater sensitivity. Finally, our finding that numerical aberration patterns in primary breast tumors and corresponding metastatic effusions are comparable indicates that FISH examination of primary tumors will indicate the centromeric probe(s) best suited for an efficient search for metastasis in the individual case.

Adenocarcinoma↗
PubMed2000

[Randomized double-blind study (third place blinded) to examine the effectiveness and side effects of methacholine in the nonspecific bronchial provocation test].

Softly and effectiveness of methacholine for the diagnosis of non-specific bronchial hyperresponsiveness [BHR] were tested in a third place blinded study. 61 patients suspected to suffer from BHR took part. 56 subjects provided complete data and were included in the study. 27 participants were challenged with methacholine 0.33% (verum) and 29 patients received NaCl 0.9% (placebo). The challenge was applied as 5-step-test using a storage bag. The doses were elevated by doubling the aerosol volume. A positive test result was assumed when basal specific airway resistance (sRt) reduplicated and simultaneously 2.0 (kPa*s) was attained. Ten out of 27 subjects in the verum group (33.3%) had a positive test result whereas in the placebo group only one subject showed a reaction (3.5%). A statistically significant association between the change of sRt and the cumulative methacholine dose was confirmed in the verum group (p < 0.002), whereas this effect could not be observed in patients challenged with placebo (p = 0.20). Side effects did not occur. We conclude that inhalative challenge with methacholine 0.33% applied as a 5-step-test is suitable to objectify BHR. The substantial benefit of the applied test scheme is the short range of time in which the challenge can be performed (approximately 20 min) and that dilution series of the test substance (methacholine 0.33%) are not required.

Adult↗