Rapamycin inhibits cdk4 activation, p 21(WAF1/CIP1) expression and G1-phase progression in transformed mouse fibroblasts.

Rapamycin, a bacterial macrolide antibiotic, is a potent immunosuppressant agent that blocks cell proliferation by inhibiting the G1/S transition in several cell types. In sensitive cells, rapamycin inhibits the phosphorylation of p70 S6K and of Rb; however, the precise mechanisms involved have not been elucidated. In the mouse BP-A31 fibroblasts, synchronised in G0/G1 phase by serum starvation and induced to reinitiate the G1-phase progression, rapamycin inhibited the entry into S phase.

Investigation of gamma camera detector uniformity using a dynamic line phantom.

Background: Investigation of the applicability of the dynamic line phantom for determination o the uniformity of circular and rectangular field-of-view gamma cameras.

Methods: Count rate - activity and uniformity - count rate functions were determined by the dynamic line phantom on three circular field-of-view gamma cameras with 37 PMTs, on one circular field of view camera with 19 PMTs, and on one rectangular field-of view gamma camera with 59 PMTs, with and without a collimator. For an evaluation of the efficacy of the dynamic line phantom, the results were compared with the uniformity values obtained with a 99mTc point source and a 57-Co sheet source.

Accurate determination of metabolic rates from dynamic positron emission tomography data with very-low temporal resolution.

Purpose: The graphical approach is widely used for the pixelwise determination of local metabolic rate of glucose from dynamic positron emission tomography (PET) data. In its conventional implementation, measured integrals over time frames are used to approximate instantaneous tracer concentrations at midframe times ("midframe approach"). This is justified in case of high temporal resolution of the PET measurement; that is, if scan protocols with a large number of short frames are used.

Use of molecular methods to identify the Mycobacterium tuberculosis complex (MTBC) and other mycobacterial species and to detect rifampin resistance in MTBC isolates following growth detection with the BACTEC MGIT 960 system.

A prospective study was organized by using a total of 1,585 consecutive clinical specimens to determine whether biomass obtained from positive growth in the MGIT 960 system could be used directly in AccuProbe DNA hybridization tests, the PCR-based Inno-LiPA Rif.TB (LiPA) assay, and a PCR-based DNA sequencing of the rpoB gene for the rapid identification of the Mycobacterium tuberculosis complex (MTBC) and other mycobacterial species and for the determination of rifampin (RIF) resistance in MTBC strains. The results were compared to routine culture, identification, and susceptibility testing techniques performed on the same samples.

Improved statistical power of the multilinear reference tissue approach to the quantification of neuroreceptor ligand binding by regularization.

A multilinear reference tissue approach has been widely used recently for the assessment of neuroreceptor-ligand interactions with positron emission tomography. The authors analyzed this "multilinear method" with respect to its sensitivity to statistical noise, and propose regularization procedures that reduce the effects of statistical noise. Computer simulations and singular value decomposition of its operational equation were used to investigate the sensitivity of the multilinear method to statistical noise.

Analysis of tuberculosis surveillance in Hungary in 2000.

Setting: Hungary, Central Europe, with a population of 10.3 million living in 20 administrative districts (19 counties and the capital).

Objective: To summarize the results of the first year of the revised National Tuberculosis Surveillance System.

Laboratory diagnosis of nontuberculous mycobacteria.

In conclusion, it is important to realize that there is no "stand alone" assay for the identification of NTM. Many new species may not be recognized in all assays. Newer molecular tests are more accurate for identification than phenotypic tests and have significantly improved turnaround time.

The c-kit tyrosine kinase inhibitor STI571 for colorectal cancer therapy.

The c-kit tyrosine kinase inhibitor STI571 exhibits a substantial therapeutic activity in patients with chronic myeloid leukemia and gastrointestinal stromal tumors respectively associated with constitutive activation of the BCR-ABL and c-kit tyrosine kinases. Human colorectal tumors also express the c-kit proto-oncogene. The present study focuses on the anticancer activity of STI571 in human colorectal tumor cells in vitro and in vivo.

Transcriptional activation by the oestrogen receptor alpha is modulated through inhibition of cyclin-dependent kinases.

We have investigated the interaction between the expression of p21(WAF1/CIP1/SDI1), a stoichiometric inhibitor of Cdk, and the transcriptional activity of the oestrogen receptor alpha (ER(alpha). Transient transfection experiments demonstrated that the expression of p21(WAF1/CIP1/SDI1) amplified the transcriptional activation by ER(alpha). A dominant negative mutant of Cdk2 also enhanced the ER(alpha) transcriptional activity, indicating that the underlying mechanism relies on the inhibition of Cdk2 activity and cell cycle arrest.

A model analysis of internal loads, energetics, and effects of wobbling mass during the whole-body vibration.

The internal loads, energetics, and the effects of wobbling mass during the whole-body vibration are studied in terms of analysis and comparison of two models: one is a system of four degrees-of-freedom with rigid and wobbling masses in both lower body and upper body (Model A), while the other one (Model B) is a system of three degrees-of-freedom with a rigid upper body and is otherwise identical to Model A. The main findings are the following: (1) The wobbling mass in the upper body is able to reduce the total internal load on the rigid mass of the upper body considerably. (2) "Partial" internal loads on a certain part of the body may be even larger than the total load on the same part of the body because of the phase differences among the partial loads.

Cellular effects of purvalanol A: a specific inhibitor of cyclin-dependent kinase activities.

We have studied the effects of purvalanol A on the cell cycle progression, proliferation and viability. In synchronized cells, purvalanol A induced a reversible arrest the progression in G1 and G2 phase of the cell cycle, but did not prevent the completion of DNA synthesis in S-phase cells. The specificity of action of the drug was supported by the selective inhibition of the phosphorylation of cyclin-dependent kinase (cdk) substrates such as Rb and cyclin E.

[Prevalence of iodine- and thyroglobulin-negative findings in differentiated thyroid cancer.A retrospective analysis of patients treated from 1951 to 1998 in university hospital].

Aim: The prevalence of iodine- and thyroglobulin-negative findings was evaluated in all patients with differentiated thyroid cancer (DTC) treated from 1961 until 1998 at the Department of Nuclear Medicine, University Hospital Hamburg-Eppendorf.

Methods: A total of 490 patients with papillary thyroid cancer (PCA) and 242 patients with follicular thyroid cancer (FCA) were analyzed retrospectively. Patients were divided into four groups: 1: no recurrence, 2: recurrent disease, 3: primary metastatic/progressive disease and 4: inconclusive follow-up.

Molecular characterization of rifampin-resistant isolates of Mycobacterium tuberculosis from Hungary by DNA sequencing and the line probe assay.

Two regions of rpoB associated with rifampin resistance were sequenced in 29 rifampin-resistant (determined by the proportion method) isolates of Mycobacterium tuberculosis obtained from patients from three counties in Hungary. Of the 29 resistant strains, 27 had a mutation in either the 81-bp region (26 strains) or the N-terminal region (1 strain), while the other 2 strains had no mutations in either region. The locations and frequencies of the mutations differed from those previously reported.

Insulin-like growth factor binding proteins and mitogenic activity of partially fractionated sheep amniotic fluid.

Amniotic fluid collected from ewes on various days of gestation was examined for the presence of insulin-like growth factor (IGF) binding proteins. IGF-binding proteins with a molecular mass of 40-45 kDa appeared at day 41 of gestation. The level of these major IGF-binding proteins increased during pregnancy and reached a maximum at day 106.

Mitogenic activity of high molecular weight forms of insulin-like growth factor-II in amniotic fluid.

Amniotic fluid (AF) collected from ewes and goats at mid gestation displayed mitogenic activity in mouse fibroblasts. Upon fractionation of this material by size exclusion chromatography, the mitogenic activity was resolved into two peaks, whose activity was inhibited by an anti-IGF type 1 receptor blocking antibody. One of the peaks contained IGF-I and IGF-II (mature form), whereas the other contained high M(r) precursor forms of IGF-II.

Low-cost, small-animal shelf for simultaneously assessing several small animals with a whole-body PET scanner.

Objective: The purpose of this work was to establish a low-cost device for simple positioning of several small animals within a whole-body PET scanner.

Methods: The device was designed as a stackable shelf for 3 x 3 animals, similar to a stackable shelf for wine bottles. It was constructed from ordinary PVC drain pipe and acrylic panes.

Comparison of rate of development and rate of change for benign and malignant breast calcifications at the lumpectomy bed.

Objective: The study purpose was to evaluate the rate of development and the rate of change for benign and malignant breast calcifications at the lumpectomy bed.

Materials And Methods: Retrospective review identified 53 new calcifications at the lumpectomy bed in patients with available mammograms and medical records. Breast Imaging Reporting and Data System (BI-RADS) categories were retrospectively assigned on the basis of initial prospective recommendation for yearly follow-up (category 2), 6-month follow-up (category 3), or biopsy (category 4 or 5).

Salivary gland protection by S-2-(3-aminopropylamino)-ethylphosphorothioic acid (amifostine) in high-dose radioiodine treatment: results obtained in a rabbit animal model and in a double-blind multi-arm trial.

Since differentiated thyroid cancer has an excellent prognosis, reduction of long-term side effects of high-dose radioiodine treatment (HD-RIT), i.e. salivary gland impairment is important.

FDG PET detection of unknown primary tumors.

Unlabelled: The management of patients presenting with metastases of unknown primary origin remains a clinical challenge despite a large variety of imaging modalities. The aim of this study was to evaluate FDG PET in detecting the sites of primary cancer in these patients.

Methods: Fifty-three patients with metastatic cervical adenopathy (n = 44) or extracervical metastases (n = 9) of unknown primary origin were included after extensive but inconclusive conventional diagnostic work-up.

B-ind1, a novel mediator of Rac1 signaling cloned from sodium butyrate-treated fibroblasts.

Sodium butyrate is a multifunctional agent known to inhibit cell proliferation and to induce differentiation by modulating transcription. We have performed differential display analysis to identify transcriptional targets of sodium butyrate in Balb/c BP-A31 mouse fibroblasts. A novel butyrate-induced transcript B-ind1 has been cloned by this approach.

Biological reaction to vibration--implications for sport.

In many situations of everyday life, vibration load occurs. Here whole body vibration in vehicles, such as boats, cars, helicopters and others as well as hand-transmitted vibration (motor saws etc.) can be named.