Quantification of 16S rRNAs in complex bacterial communities by multiple competitive reverse transcription-PCR in temperature gradient gel electrophoresis fingerprints

Uncultured predominant Bacillus ribotype DA001 in Dutch Drentse A grassland soils, as revealed by its 16S rRNA sequence, was detected in soil by fluorescent whole-cell in situ hybridization. A prominent rod-shaped cell type was identified in bacterial suspensions prepared from soil by a multiple 16S rRNA probing approach.     

Estimation of conduction velocity vector fields from epicardial mapping data

An automated method to estimate vector fields of propagation velocity from observed epicardial extracellular potentials is introduced. The method relies on fitting polynomial surfaces T(x, y) to the space-time (x, y, t) coordinates of activity. Both speed and direction of propagation are computed from the gradient of the local polynomial surface. The components of velocity, which are total derivatives, are expressed in terms of the partial derivatives which comprise the gradient of T. The method was validated on two-dimensional (2-D) simulations of propagation and then applied to cardiac mapping data. Conduction velocity was estimated at multiple epicardial locations during sinus rhythm, pacing, and ventricular fibrillation (VF) in pigs. Data were obtained via a 528-channel mapping system from 23 x 22 and 24 x 21 arrays of unipolar electrodes sutured to the right ventricular epicardium. Velocity estimates are displayed as vector fields and are used to characterize propagation qualitatively and quantitatively during both simple and complex rhythms.     

Strategies to target kyotorphin analogues to the brain

The design, synthesis, and pharmacological evaluation of brain-targeted chemical delivery systems (CDS) for a kyotorphin analogue (Tyr-Lys) are described. The brain-targeted compound contains the active peptide in a packaged, disguised form, flanked between the lipophilic cholesteryl ester on the C-terminus and the 1, 4-dihydrotrigonellyl redox targetor, attached to the N-terminus through strategically selected L-amino acid(s) spacer. It was found that for successful brain targeting, the epsilon-amine of Lys needs to be also converted to a lipophilic function. Through sequential enzymatic bioactivation, the Tyr-Lys dipeptide is released in a sustained manner, producing significant and prolonged analgesic activity as demonstrated by the rat tail latency test. An alternate strategy was also employed. Lys was replaced by a redox amino acid pair, Nys+ left and right arrow Nys, the nicotinamide left and right arrow 1,4-dihydronicotinamide analogues of Lys (Nys+ is 2-amino-6-(3-carbamoyl-1-pyridiniumyl)hexanoic acid). The Nys form is lipophilic and facilitates delivery in addition to the C- and N-terminal lipophilic functions. Enzymatic oxidation to Nys+ provides the lock-in, followed by removal of the lipophilic groups, releasing Tyr-Nys+ from the brain-targeted analogue (BTRA). Nys+ was shown to be an effective substitution for Arg or Lys. The activities of the CDS and BTRA, respectively, were antagonized by naloxone, supporting the designed brain-targeted processes. The most potent compound is the two-proline spacer containing CDS (CDS-PP), followed by the BTRA.     

The RET/PTC3 oncogene: metastatic solid-type papillary carcinomas in murine thyroids

Our research goal is to better understand the mechanisms controlling the initiation and progression of thyroid diseases. One such disease, papillary thyroid carcinoma (PTC), is the leading endocrine malignancy in the United States. Recently, a family of related fusion proteins, RET/PTC1-5, has been implicated in the early stages of PTC. Although all five members of this family have the c-RET proto-oncogene kinase domain in their COOH terminus, little is known about how these genes alter follicular cell biology. Consequently, to answer questions related to the mechanism of the RET/PTC fusion protein action, we have devised a molecular genetic strategy to study PTC using a mouse model of thyroid disease. A new member of this fusion oncogene family, RET/PTC3, which has been implicated in more cases of solid tumor carcinoma (79%) than PTC1 or PTC2 and predominates (80%) in radiation-induced thyroid cancer of children, was investigated in our study. We have generated transgenic mice expressing human RET/PTC3 exclusively in the thyroid. These mice develop thyroid hyperplasia, solid tumor variants of papillary carcinoma and metastatic cancer. This new transgenic line will be useful in deciphering the molecular and biological mechanisms that cause PTC and histological variations in humans.     

A novel form of hereditary myeloperoxidase deficiency linked to endoplasmic reticulum/proteasome degradation

Myeloperoxidase (MPO) deficiency is a common inherited disorder linked to increased susceptibility to infection and malignancy. We identified a novel missense mutation in the MPO gene at codon 173 whereby tyrosine is replaced with cysteine (Y173C) that is associated with MPO deficiency and assessed its impact on MPO processing and targeting in transfectants expressing normal or mutant proteins. Although the precursor synthesized by cells expressing the Y173C mutation (MPOY173C) was glycosylated, associated with the molecular chaperones calreticulin and calnexin, and acquired heme, it was neither proteolytically processed to mature MPO subunits nor secreted. After prolonged association with calreticulin and calnexin in the endoplasmic reticulum, MPOY173C was degraded. Furthermore, the 20S proteasome inhibitor N-acetyl-L-leucinyl-L-leucinyl-L-norleucinyl inhibited its degradation, suggesting that the proteasome mediates proteolysis of MPOY173C and, thus, participates in quality control in this novel form of hereditary MPO deficiency.     

Taking chances: problem gamblers and mental health disorders--results from the St. Louis Epidemiologic Catchment Area Study

OBJECTIVES: This study determined prevalence estimates of problem gambling and relationships to other psychiatric and substance use disorders. METHODS: In 1981, the Diagnostic Interview Schedule was used to collect epidemiological information on problem gambling and other disorders from 3004 adults in St. Louis, Mo. RESULTS: The lifetime prevalence of pathological gambling was 0.9%; 46% of those surveyed gambled recreationally. Problem gamblers (those reporting at least one gambling-related problem) were 9.2% of the sample and were predominately White (69%), male (78.2%), and young than nongamblers. They were at increased risk for several psychiatric diagnoses, especially for antisocial personality disorder, alcoholism, and tobacco dependence. CONCLUSIONS: Clinicians treating alcoholism and tobacco dependence may need to screen for problem gambling. Additional research in the context of increased gambling opportunities is needed.     

Determination of n-hexane metabolites by liquid chromatography/mass spectrometry. 1. 2,5-hexanedione and other phase I metabolites in untreated and hydrolyzed urine samples by atmospheric pressure chemical ionization

The capabilities of atmospheric pressure chemical ionization liquid chromatography/mass spectrometry (APCI-LC/MS) were investigated for the analysis of urinary 2,5-hexanedione (2,5-HD) and for the identification and characterization of other n-hexane Phase I metabolites in hydrolized urine samples. Chromatography was performed under reversed phase conditions at 0.75 mL min-1 flow rate. The ionization of 2,5-HD and other n-hexane metabolites was obtained in positive ion mode. After optimization of several interface parameters, the linearity, sensitivity and precision of the method were determined operating in the selected ion monitoring mode. Detection limits were 0.02 and 0.05 mg L-1 in water and urine respectively, with linear calibration curves in the 0.05-10 L-1 concentration range. Repeatability and both intra-day and inter-day precision were determined at two concentration levels (0.5 and 5.0 mg L-1), and relative standard deviations were in the 1.3%-5.3% range. The method was applied to the quantitative analysis of 2,5-HD in urine samples from an external Quality Assurance Programme for Organic Solvent Metabolites. Moreover, the metabolites 5-hydroxy-2-hexanone, 2,5-hexanediol and 4,5-dihydroxy-2-hexanone were identified and confirmed in hydrolyzed urine of rats exposed to n-hexane.     

Detection of epitopes on follicle-stimulating hormone and FSH-antiserum-induced suppression of bioactivity of follicle-stimulating hormone and luteinizing hormone

There are currently two major approaches to hormonal male contraception. One relies on testosterone (analogs) either alone or in combination with gonadotropin releasing hormone (GnRH) (analogs or immunizations), the other on immunizations against follicle-stimulating hormone (FSH). Theoretically, the latter method will suppress spermatogenesis whilst not interfering with libido. An absolute requirement is, however, that an anti-FSH vaccine does not include anti-luteinizing hormone (LH) antibodies (LH being responsible for the induction of testosterone which is necessary to maintain libido). In this report we show that when whole FSH is used for vaccination, in most cases in addition to biological activity against FSH, anti-LH activity is also induced. By systematic analysis of the antisera raised with FSH using systematic epitope scanning (PEPSCAN) we found differences between the FSH-specific and FSH-nonspecific sera. Only the FSH-specific antiserum contained antibodies that recognized amino acid sequence 37-55 on the beta-subunit in a linear manner. Because antibodies against this epitope have not been found in the cross-reactive sera this epitope forms a prime candidate for an anti-FSH contraceptive vaccine.     

Serum interleukin-6 levels in metastatic renal cell carcinoma before treatment with interleukin-2 correlates with paraneoplastic syndromes but not patient survival

PURPOSE: We sought to determine the frequency of interleukin-6 (IL-6) expression in renal cancer cell lines, the frequency of the detection of IL-6 in the serum of patients with metastatic renal cell carcinoma, whether serum IL-6 level correlates with the development of paraneoplastic syndromes and whether serum IL-6 level in patients with metastatic renal cancer correlates with response to treatment with interleukin-2 (IL-2) or patient survival. MATERIALS AND METHODS: Conditioned media from 21 cell lines from 20 patients were examined for IL-6. We identified 2 matched groups of patients with metastatic renal cancer (30 responders and 29 nonresponders) to IL-2 based immunotherapy. Stored pretreatment serum specimens were evaluated for IL-6. Medical records were reviewed to determine the presence of paraneoplastic syndromes. RESULTS: IL-6 was detected in 19 of 21 renal cancer cell lines (90%) obtained from 20 patients with metastatic renal cancer as well as in the serum of 33 of 59 patients (56%) with metastatic renal cell carcinoma. A significant association between serum IL-6 level and anemia (p = 0.0032), elevated platelet count (p = 0.01), decreased albumin (p = 0.034) and elevated alkaline phosphatase (p = 0.04) was found. A trend was noted of the association of increased serum IL-6 level and fever (p = 0.051). No correlation was found between pretreatment serum IL-6 level and survival or response to IL-2. CONCLUSIONS: IL-6 was frequently secreted by renal cancer cell lines but it was only present in the serum of approximately half of the patients with metastatic renal cancer. Elevations of serum IL-6 were associated with paraneoplastic manifestations frequently seen in patients with renal cancer, including anemia, thrombocytosis, decreased albumin and elevations of alkaline phosphatase (Stauffer's syndrome). A weak relationship was noted between serum IL-6 level and fever but none was noted between that and survival or response to IL-2.