Biomedical subjects

P Huber

Publications and source records attributed to P Huber.

At least 55 records · Page 3Linked to original sources

PubMed2000

Urinary level of nuclear matrix protein 22 in the diagnosis of bladder cancer: experience with 130 patients with biopsy confirmed tumor.

PURPOSE: We prospectively evaluated the value of nuclear matrix protein 22 (NMP22dagger) and cytology in the diagnosis of bladder cancer. MATERIALS AND METHODS: We analyzed NMP22 in voided urine from 235 patients before cystoscopy. Of the patients 130 had transitional cell carcinoma of the bladder and subsequently underwent surgery. In a subset of 200 patients bladder washout samples for cytology were collected during cystoscopy. The cutoff for NMP22 was 10.0 units per ml. For cytology only high grade atypia was considered positive. RESULTS: Histology showed 77 superficial (pTa, pTis) and 53 invasive (pT1 or greater) tumors. Sensitivity of NMP22 was 51% and specificity was 83%. NMP22 sensitivity was 36% for superficial tumors and 73% for invasive transitional cell carcinoma. Overall sensitivity of cytology was 52% and specificity was 89%. Cytology sensitivity was 38% for superficial tumors and 83% for invasive transitional cell carcinoma. NMP22 sensitivity for grades 1, 2 and 3 tumors was 30%, 56% and 68%, respectively. Cytology sensitivity for grades 1, 2 and 3 tumors was 30%, 50% and 91%, respectively. Combined NMP22 and cytology had a sensitivity of 70%. CONCLUSIONS: NMP22 has sensitivity and specificity similar to those of cytology from bladder washout samples. Particularly in low stage and low grade tumors both tests show the same disappointing sensitivity. Because of a false-negative rate of 49%, NMP22 cannot replace cystoscopy in clinical practice, as the danger of missing NMP22 negative tumors is too high to rely on its results in an individual patient.

Biomarkers, Tumor↗

PubMed1999

[Functional dynamics of impending overt hypothyroidism: spontaneous evolution in patients in the years before the beginning of treatment].

The syndrome of subclinical hypothyroidism, with its clinical and metabolic consequences, is frequent. Only a minority of these patients will eventually become overtly hypothyroid. It was the aim of the present study to analyse the spontaneous evolution over 10 years of 27 patients with subclinical hypothyroidism who became overtly hypothyroid (group A). For comparison, 27 patients remaining subclinically hypothyroid and matched for their TSH concentrations were characterised (group B). In group A, continuous increase of TSH concentrations was observed over the whole observation period (p = 0.002; ANOVA). The concentrations of fT4 remained initially stable, and only fell at a late stage in the three years before overt hypothyroidism (p = 0.0001; ANOVA). The concentrations of total T3 remained normal throughout the observation period. Thyroid reserve was already impaired at the beginning and during the whole study period. In contrast, these thyroid parameters of patients of group B remained unchanged over 10 years, and thyroid reserve remained normal. The pathogenesis of overt hypothyroidism is a graded process. Increasing concentrations of TSH, a decrease of fT4 and impaired thyroid reserve are predictors of overt thyroid failure.

Analysis of Variance↗

PubMed1999

Synergistic interaction of ultrasonic shock waves and hyperthermia in the Dunning prostate tumor R3327-AT1.

Pulsed high-energy ultrasound shock waves (PHEUS), similar to those used for clinical lithotripsy, can deposit energy deep in tissue and thereby destroy the microvasculature of solid tumors. We investigated the potential of PHEUS, generated by an electromagnetic shockwave source (19 kV capacitor voltage, 1 Hz pulse frequency), as a local cancer-therapy modality alone and in combination with local tumor hyperthermia (43.5 +/- 0.1 degrees C, 30 min). Copenhagen rats transplanted with the anaplastic Dunning-prostate-tumor sub-line R3327-AT1 received 1000 PHEUS pulses, which delayed tumor growth by one tumor-doubling time (5 days). Histopathology revealed hemorrhage, disruption of tumor vasculature, and necrosis in the focus of the sound field. Bromodeoxyuridine (BUdR) incorporation was significantly lower in PHEUS-treated tumors than in controls. Dynamic magnetic resonance imaging (MRI) studies using gadolinium-DTPA as contrast agent showed a strong reduction of tumor perfusion after PHEUS treatment, although this effect was partly reversible within 3 days after PHEUS. While hyperthermia alone produced no significant delay in tumor growth, the combination of PHEUS and hyperthermia produced tumor-growth delay by 2 tumor-volume-doubling times. The maximum growth delay was achieved when PHEUS and hyperthermia were separated by 24 hr at the time of maximum perfusion reduction indicated by MRI. Thus, the cytotoxic effect of PHEUS was enhanced by hyperthermia in the anaplastic prostate tumor R3327-AT1 grown on Copenhagen rats in a synergistic manner, due to blood-flow reduction. In conjunction with other agents, such as hyperthermia, PHEUS might become a local cancer-therapy modality in solid tumors accessible to ultrasound.

Animals↗

PubMed1999

The vascular endothelial-cadherin promoter directs endothelial-specific expression in transgenic mice.

Vascular endothelial-cadherin (VE-cadherin) is a calcium-dependent adhesive molecule, exclusively and constitutively expressed in endothelial cells. Analysis of the VE-cadherin promoter fused to a reporter gene in bovine aortic endothelial cells showed three major functional regions. The proximal region alone (-139, +24) promoted nonspecific transcription; the addition of the (-289, -140) and (-2226, -1190) domains abolished transcription in fibroblasts while expression in endothelial cells remained unchanged, suggesting that fragments (-2226, +24) and longer contain the full endogenous promoter activity. To study the transcriptional specificity of the promoter region in vivo, we generated transgenic mice carrying the chimeric construct containing the (-2486, +24) region. The promoter directed reporter expression in all examined organs of adult transgenic mice. During embryonic development, transgene expression was detected at the early steps of vasculogenesis. Later, the expression persisted during development of the vascular system and was restricted to the endothelial layer of the vessels. Together, these data provide evidence for specific regulatory regions within the VE-cadherin promoter. Furthermore, the identification of DNA sequences restricting gene expression to the endothelium has many potential applications for the development of animal models of cardiovascular or angiogenic diseases or for the delivery of therapeutic molecules.

5' Untranslated Regions↗

PubMed1999

Merkel cell carcinoma: the role of radiation therapy in general management.

BACKGROUND: Merkel cell carcinoma (MCC) is a rare malignant, locally aggressive tumor of the skin. Because few data exist about the clinical course of irradiated patients, we reviewed the 17 patients treated at our institution since 1982. PATIENTS AND METHODS: The median age at diagnosis was 71 years (range 47 to 88 years). Twelve patients presented with lymph node involvement (Stage II), 5 patients with negative lymph nodes (Stage I). Five patients were irradiated immediately after initial surgical excision of the primary tumor. Eleven patients underwent a surgical treatment of recurrence prior to the first irradiation. Only 1 patient received primary radiotherapy. A median dose of 52.8 Gy (range 40 to 60 Gy) in the region of the primary tumor and a median dose of 49.5 Gy (range 30 to 54 Gy) in the regional lymph nodes were delivered. RESULTS: The median overall survival after first diagnosis was 45 months. Three-year overall survival was 57%, 5-year cause-specific survival was 73% (Kaplan Meier). Local control could be achieved in the 5 patients irradiated immediately after surgical treatment of the primary tumor. In contrast, an in-field recurrence occurred in 5 of 12 patients irradiated after surgical excision of relapsed disease. Five patients developed distant metastases. None of these patients was irradiated immediately after surgical excision of the primary tumor. CONCLUSIONS: With respect to our experience, a local control can be achieved with an immediate postoperative radiotherapy of the primary tumor site and the adjacent lymph nodes.

Aged↗

PubMed1999

Sonochemically induced radicals generated by pulsed high-energy ultrasound in vitro and in vivo.

The aim of this study was to evaluate the role of radicals as a mechanism of tissue damage induced by pulsed high-energy ultrasound. Transient cavitation has proved to be an important mechanism for the generation of reactive radical species during pulsed high-energy ultrasound applications. The amount of radicals studied in in vitro experiments using a chemical dosimeter based on iodine release is proportional to the number of pulses. Sonications of the R3327-AT1 subline of the Dunning prostate rat tumor transplanted in the thigh of Copenhagen rats were performed applying 500 and 2000 pulses at a pulse repetition frequency of 1 Hz. Tumor growth after treatment was compared with sham-treated controls. We were able to assess a significant growth delay, but could not find a significant difference between the two groups treated. In conclusion, radical formation does not seem to be the major mechanism for tissue necrosis induced by pulsed high-energy ultrasound.

Adenocarcinoma↗

PubMed1999

Quantitative MR temperature monitoring of high-intensity focused ultrasound therapy.

A new quantitative method has been developed for real-time mapping of temperature changes induced by high intensity focused ultrasound (HIFU). It is based on the temperature dependence of the T1 relaxation time and the equilibrium magnetization. To calibrate the temperature measurement, the functional relationship between T1 and temperature was examined in different samples of porcine muscle and fatty tissue. The method was validated by a comparison of calculated temperature maps with fiber-optic measurements in heated muscle tissue. The experiment showed that the accuracy of the MR method for temperature measurements is better than 1 degree C. Since the acquisition time of the employed MR sequence takes only 3 s per slice and the calculation of the temperature map can be performed within seconds, the imaging technique works nearly in real-time. The temperature measurement could be realized during HIFU showing no disturbances by ultrasound sonication. In comparison to other MR approaches, the advantages of the introduced method lie in a sufficient accuracy and time resolution combined with a reasonable robustness against motion as well as the feasibility for temperature monitoring in fatty tissues.

Adipose Tissue↗

PubMed1999

Detecting anxiety and depression in hospitalised elderly patients using a brief inventory.

This study validated a French language version of an inventory designed to detect symptoms of depression and anxiety [Goldberg et al, 1987] in a sample of elderly French-speaking inpatients at risk for one of these disorders. Latent trait analysis was used to replicate the structure of the symptoms in the inventory, and receiver operating characteristic analysis was used to assess the performance of the inventory as a screening measure for Major Depressive Episode and Generalised Anxiety Disorder according to DSM-IV criteria. Reflecting the ascertainment of individuals in the sample as being at risk for a disorder, prevalence of individual symptoms was high although the general structure of the inventory was found to be comparable to that found in samples of both community elderly and younger medical patients. ROC analyses showed that the subscales of inventory performed satisfactorily as screening measures for anxiety or depression but lacked specificity for each disorder. In addition to providing further evidence for the utility of this inventory to detect general psychiatric distress in elderly persons, this study provides a valid means of detecting symptoms of depression and anxiety in French speaking groups.

Aged↗

PubMed1999

Control of cavitation activity by different shockwave pulsing regimes.

The aim of the study was to control the number of inertial cavitation bubbles in the focal area of an electromagnetic lithotripter in water independently of peak intensity, averaged intensity or pressure waveform. To achieve this, the shockwave pulses were applied in double pulse sequences, which were administered at a fixed pulse repetition frequency (PRF) of 0.33 Hz. The two pulses of a double pulse were separated by a variable short pulse separation time (PST) ranging from 200 micros to 1500 ms. The number and size of the cavitation bubbles were monitored by scattered laser light and stroboscopic photographs. We found that the number of inertial cavitation bubbles as a measure of cavitation dose was substantially influenced by variation of the PST, while the pressure pulse waveform, averaged acoustic intensity and bubble size were kept constant. The second pulse of each double pulse generated more cavitation bubbles than the first. At 14 kV capacitor voltage, the total number of cavitation bubbles generated by the double pulses increased with shorter PST down to approximately 400 micros, the cavitation lifespan. The results can be explained by cavitation nuclei generated by the violently imploding inertial cavitation bubbles. This method of pulse administration and cavitation monitoring could be useful to establish a cavitation dose-effect relationship independently of other acoustic parameters.

Dose-Response Relationship, Radiation↗

PubMed1999

The gammaPE complex contains both SATB1 and HOXB2 and has positive and negative roles in human gamma-globin gene regulation.

A large nuclear protein complex, termed gammaPE (for gamma-globin promoter and enhancer binding factor), binds to five sites located 5' and 3' of the human y-globin gene. Two proteins, SATB1 (special A-T-rich binding protein 1) and HOXB2, can bind to yPE binding sites. SATB1 binds to nuclear matrix-attachment sites, and HOXB2 is a homeodomain protein important in neural development that is also expressed during erythropoiesis. The present work showed that antisera directed against either SATB1 or HOXB2 reacted specifically with the entire gammaPE complex in electrophoretic mobility shift assays (EMSAs), suggesting that the two proteins can bind to the gammaPE binding site simultaneously. When SATB1 or HOXB2 was expressed in vitro, they could bind independently to gammaPE binding sites in EMSA. Interestingly, the proteins expressed in vitro competed effectively with each other for the gammaPE binding site, suggesting that this may occur under certain conditions in vivo. Transient cotransfections of a HOXB2 cDNA and a y-globin-luciferase reporter gene construct into cells expressing SATB1 suggested that SATB1 has a positive and HOXB2 a negative regulatory effect on transcription. Taking into account their potentially opposing effects and binding activities, SATB1 and HOXB2 may modulate the amount of gamma-globin mRNA expressed during development and differentiation.

Animals↗

PubMed1999

Identification and analysis of the balhimycin biosynthetic gene cluster and its use for manipulating glycopeptide biosynthesis in Amycolatopsis mediterranei DSM5908.

Seven complete genes and one incomplete gene for the biosynthesis of the glycopeptide antibiotic balhimycin were isolated from the producer, Amycolatopsis mediterranei DSM5908, by a reverse-cloning approach and characterized. Using oligonucleotides derived from glycosyltransferase sequences, a 900-bp glycosyltransferase gene fragment was amplified and used to identify a DNA fragment of 9,882 bp. Of the identified open reading frames, three (oxyA to -C) showed significant sequence similarities to cytochrome P450 monooxygenases and one (bhaA) showed similarities to halogenase, and the genes bgtfA to -C showed similarities to glycosyltransferases. Glycopeptide biosynthetic mutants were created by gene inactivation experiments eliminating oxygenase and glycosyltransferase functions. Inactivation of the oxygenase gene(s) resulted in a balhimycin mutant (SP1-1) which was not able to synthesize an antibiotically active compound. Structural analysis by high-performance liquid chromatography-mass spectrometry, fragmentation studies, and amino acid analysis demonstrated that these oxygenases are involved in the coupling of the aromatic side chains of the unusual heptapeptide. Mutant strain HD1, created by inactivation of the glycosyltransferase gene bgtfB, produced at least four different compounds which were not glycosylated but still antibiotically active.

Anti-Bacterial Agents↗

PubMed1999

Role of vascular endothelial-cadherin in vascular morphogenesis.

Vascular endothelial (VE)-cadherin is an adhesive transmembrane protein specifically expressed at interendothelial junctions. Its extracellular domain exhibits Ca2+-dependent homophilic reactivity, promoting cell-cell recognition. Mice deficient in VE-cadherin die at mid-gestation resulting from severe vascular defects. At the early phases of vascular development (E8.5) of VE-cadherin-deficient embryos, in situ differentiation of endothelial cells was delayed although their differentiation program appeared normal. Vascularization was defective in the anterior part of the embryo, while dorsal aortae and vitelline and umbilical arteries formed normally in the caudal part. At E9.25, organization of endothelial cells into large vessels was incomplete and angiogenesis was impaired in mutant embryos. Defects were more severe in extraembryonic vasculature. Blood islands of the yolk sac and clusters of angioblasts in allantois failed to establish a capillary plexus and remained isolated. This was not due to defective cell-cell recognition as endothelial cells formed intercellular junctions, as shown by electron microscopy. These data indicate that VE-cadherin is dispensable for endothelial homophilic adhesion but is required for vascular morphogenesis.

Animals↗

PubMed1999

Application of the polymerase chain reaction to detect fowl adenoviruses.

The possibility of using the polymerase chain reaction (PCR) for the detection of fowl adenoviruses (FAdV) was tested. The optimal reaction parameters were evaluated and defined for purified genomic DNA of type 8 fowl adenovirus (FAdV-8), and then the same conditions were applied for nucleic acid extracted from infected cells. One hundred picograms of purified viral DNA, or 250 FAdV-8-infected cells, were detected by ethidium bromide staining of the PCR products in agarose gels. The sensitivity was increased to 10 pg purified viral DNA, or 25 infected cells, when the PCR products were hybridized with a specific labeled probe. Several field isolates of FAdV and the CELO virus (FAdV serotype 1) could be amplified by the same primers and conditions, but the size of the amplicons was smaller than that for the FAdV-8 PCR product. Other avian viruses and uninfected cell cultures tested negative.

Adenoviridae Infections↗

PubMed1999

[Endothelial intercellular junctions: relationship between vascular adhesion and morphogenesis].

Endothelial cell-cell junctions are required for integrity of the vascular system. Similar to that of epithelial cells, the interendothelial cleft contains tight, adherens and gap junctions, and the newly-defined complexus adherentes. In the past few years, the molecular components of these organelles were identified as well as their mutual interactions. These data deciphered the complex link between the cell membrane and the cytoskeleton. The contribution of these junctions in vessel formation and permeability is discussed in this review.

Animals↗

PubMed1998

[Long-term study of subclinical hypothyroidism: spontaneous course and predictors of manifest hypothyroidism].

The syndrome of subclinical hypothyroidism is frequent and predominantly affects females over 40. Only limited data on its natural course is available. It was the aim of our prospective trial to analyze the spontaneous evolution of this syndrome, to identify risk factors of the development of overt hypothyroidism and to develop guidelines for the management of such patients. 154 female patients were followed over a mean observation period of 10 years. After 10 years, 34% had developed overt hypothyroidism, 57% remained in the subclinical stage, and in 9% thyroid function had normalized. The initial grading of TSH-concentration (< 6 mU/l, 6-12 mU/l, > 12 mU/l) was highly predictive for thyroid failure: 7.3%, 25% and 78%, respectively, overt hypothyroidism occurred. Further risk factors for thyroid failure included an impaired thyroid reserve (T3-stimulation after TRH) and elevated titers of microsomal antibodies. We therefore recommend to controlling patients with a TSH-concentration < 6 mU/l, start thyroxine hormone replacement therapy in patients with a TSH-concentration > 12 mU/l and, depending on the additional risk factors, either controlling or treating patients with a TSH-concentration of 6-12 mU/l.

Adolescent↗

PubMed1998

Identification of a novel cadherin (vascular endothelial cadherin-2) located at intercellular junctions in endothelial cells.

Endothelial cells express two major cadherins, VE- and N-cadherins, but only the former consistently participates in adherens junction organization. In heart microvascular endothelial cells, we identified a new member of the cadherin superfamily using polymerase chain reaction. The entire putative coding sequence was determined. Similarly to protocadherins, while the extracellular domain presented homology with other members of the cadherin superfamily, the intracellular region was unrelated either to cadherins or to any other known protein. We propose for this new protein the name of vascular endothelial cadherin-2. By Northern blot analysis, the mRNA was present only in cultured endothelial cell lines but not in other cell types such as NIH 3T3, Chinese hamster ovary, or L cells. In addition, mRNA was particularly abundant in highly vascularized organs such as lung or kidney. In endothelial cells and transfectants, this cadherin was unable to bind catenins and presented a weak association with the cytoskeleton. This new molecule shares some functional properties with VE-cadherin and other members of the cadherin family. In Chinese hamster ovary transfectants it promoted homotypic Ca2+ dependent aggregation and adhesion and clustered at intercellular junctions. However, in contrast to VE-cadherin, it did not modify paracellular permeability, cell migration, and density-dependent cell growth. These observations suggest that different cadherins may promote homophilic cell-to-cell adhesion but that the functional consequences of this interaction depend on their binding to specific intracellular signaling/cytoskeletal proteins.

Amino Acid Sequence↗

PubMed1998

Requirement of a GT box (Sp1 site) and two Ets binding sites for vascular endothelial cadherin gene transcription.

Vascular endothelial cadherin (VE cadherin) gene encodes a Ca2+-dependent cell adhesion molecule required for the organization of interendothelial junctions. This gene is exclusively and constitutively expressed in endothelial cells. Previous data with transgenic mice revealed that the transcriptional regulatory elements present within a -2486/+24 DNA fragment of mouse VE cadherin gene mimic the tissue-specific activity of the endogenous promoter. In this study, we analyzed elements implicated in the function of the proximal regulatory region. Electrophoretic mobility shift assay identified a GT-rich sequence (positions -49/-39) interacting with factors related to the Sp1 family. Point mutations abolished the binding of nuclear proteins in vitro and drastically diminished the activity of the promoter in transient transfection assay. Supershift assays with antibodies against proteins of the Sp1 family revealed that Sp1 and Sp3 interact with this region of the VE cadherin promoter. Furthermore, two GGAA motifs, located at positions -93/-90 and -109/-106, were shown to interact with nuclear factors. Site-directed mutagenesis of these sequences demonstrated that these Ets binding sites are essential for promoter activity. In vitro binding assays in the presence of various antisera suggest that Erg is one of the proteins interacting with the -109/-106 site.

Animals↗

PubMed1998

[Ultrasensitive TSH screening for detection of thyroid gland dysfunctions in women of a medical ambulatory care patient group].

This aim of the study was to identify the prevalence of unsuspected thyroid dysfunction in a female population attending a medical primary care unit (case-finding study). A TSH assay of the third generation was used as a screening test. The overall prevalence of unsuspected thyroid dysfunction in 1061 female patients was 2.5% (0.5% overt hyperthyroidism, 0.3% overt hypothyroidism, 0.5% subclinical hyperthyroidism, and 1.2% subclinical hypothyroidism). The prevalence of thyroid disease is clearly age dependent with 4.3% over the age of 40 and 5.9% for 50-60 year-olds. The ratio for females below 40 and over 40 was 10.75 (Odds ratio, p < 0.0001). We conclude from our study and from the literature that TSH screening as a case-finding strategy is indicated, and also seems cost-effective, in women over 40 years of age.

Adolescent↗