Population-based study of cancer risk and relative survival following sphincterotomy for stones in the common bile duct

An external nasal dilator (Breathe Right, CNS, Inc., Bloomington, MN) has become popular with athletes. The dilator is an adhesive band with a central elastic strip. When applied across the nasal valve, the device theoretically increases nasal valve area. We used acoustic rhinometry (Hood Laboratories, Pembroke, MA) to measure the cross-sectional area at the nasal valve with and without the device in 53 athletes. Thirty athletes were exercised on a cycle ergometer with and without the device while measuring physiologic parameters, including oxygen consumption (VO2), heart rate, and respiratory rate. The study was conducted in a randomized, double-blind, placebo-controlled manner. At rest, the external nasal dilator was found to significantly increase nasal valve area in all demographic groups measured. The device was also found to significantly decrease submaximal exercise perceived exertion, heart rate, ventilation, and VO2 when compared with placebo.     

Human thyroglobulin reference material (CRM 457). 2nd Part: Physicochemical characterization and certification

This report describes the characterization of a purified human thyroglobulin (Tg) reference material, and details the procedures used in its certification. The purified Tg is intended to be used as a primary reference material to establish calibration of working serum based reference material for immunoassay procedures. The programme involved the participation of 15 European laboratories and one laboratory from the United States. The physicochemical characterization showed by polyacrylamide gel electrophoresis and immunoblotting that the purified Tg had for the major part the expected molecular size of 660 kDa with traces of lower molecular forms. The amino acid composition was close to that demonstrated for the cDNA and the content of iodine was in keeping with a moderately to highly iodinated Tg. The mass concentration in reference material RM 457 is certified to be (0.324 +/- 0.018) g/L on the basis of protein determined by the Lowry method and supported by nitrogen determination, absorbance measurement, and amino acid analysis. This reference material is considered the first step towards decreasing the interlaboratory variability between Tg methods of measurement.     

Molecular determinants of a Ca2+-binding site in the pore of cyclic nucleotide-gated channels: S5/S6 segments control affinity of intrapore glutamates

Cyclic nucleotide-gated (CNG) channels play an important role in Ca2+ signaling in many cells. CNG channels from various tissues differ profoundly in their Ca2+ permeation properties. Using the voltage-dependent Ca2+ blockage of monovalent current in wild-type channels, chimeric constructs and point mutants, we have identified structural elements that determine the distinctively different interaction of Ca2+ with CNG channels from rod and cone photoreceptors and olfactory neurons. Segments S5 and S6 and the extracellular linkers flanking the pore region are the only structural elements that account for the differences between channels. Ca2+ blockage is strongly modulated by external pH. The different pH dependence of blockage suggests that the pKa of intrapore glutamates and their protonation pattern differ among channels. The results support the hypothesis that the S5-pore-S6 module, by providing a characteristic electrostatic environment, determines the protonation state of pore glutamates and thereby controls Ca2+ affinity and permeation in each channel type.     

Is the activity of soluble CD14 enhanced following major trauma?

BACKGROUND: The molecule CD14 acts as a receptor for the protein-bound endotoxin (lipopolysaccharide [LPS]) complex and mediates the cellular effects of LPS. The soluble formation, sCD14, is supposed to neutralize circulating LPS (i.e., LPS antagonist) or transfer LPS effects to endothelial cells (i.e., LPS agonist). OBJECTIVE: To elucidate the release of sCD14 per se in patients with major trauma in the early posttrauma period. Our a priori hypothesis was that sCD14 release depends on the plasma LPS concentration simultaneously measured. PATIENTS: In a prospective study, 65 patients with multiple injuries (Injury Severity Score, 9-75) were enrolled. The patients were rescued by the medical helicopter service and directly admitted to our clinics. The plasma concentrations of sCD14 (enzyme immunoassay) and LPS (chromogenic limulus amebocyte lysate test) were analyzed. The first blood sample was collected immediately at the accident site. The following samples were drawn at intervals from 2 hours to daily for 2 weeks. RESULTS: Sixty-one patients survived the observation time. Immediately after trauma, their mean sCD14 level was not different from that of healthy individuals. Two hours later, a pronounced increase of sCD14 was observed and sustained throughout the observation period. Even nonsurvivors showed an increased sCD14 release, but less pronounced. In all patients, plasma LPS levels were elevated during the first 12 hours. CONCLUSIONS: Major trauma caused an increased release of sCD14. This elevation, however, was not correlated to LPS levels or to the severity of trauma (estimated by trauma scores). We found no evidence that sCD14 levels are of prognostic value regarding survival. Furthermore, the release of sCD14 did not occur in an LPS-neutralizing manner, but rendered possible an LPS-independent mechanism.     

Hydrophobic cluster analysis of G protein-coupled receptors: a powerful tool to derive structural and functional information from 2D-representation of protein sequences

Current methods for comparative analyses of protein sequences are 1D-alignments of amino acid sequences based on the maximization of amino acid identity (homology) and the prediction of secondary structure elements. This method has a major drawback once the amino acid identity drops below 20-25%, since maximization of a homology score does not take into account any structural information. A new technique called Hydrophobic Cluster Analysis (HCA) has been developed by Lemesle-Varloot et al. (Biochimie 72, 555-574), 1990). This consists of comparing several sequences simultaneously and combining homology detection with secondary structure analysis. HCA is primarily based on the detection and comparison of structural segments constituting the hydrophobic core of globular protein domains, with or without transmembrane domains. We have applied HCA to the analysis of different families of G-protein coupled receptors, such as catecholamine receptors as well as peptide hormone receptors. Utilizing HCA the thrombin receptor, a new and as yet unique member of the family of G-protein coupled receptors, can be clearly classified as being closely related to the family of neuropeptide receptors rather than to the catecholamine receptors for which the shape of the hydrophobic clusters and the length of their third cytoplasmic loop are very different. Furthermore, the potential of HCA to predict relationships between new putative and already characterized members of this family of receptors will be presented.     

Neurologic complications after irradiation of the cervical spinal cord for malignant tumour of the head and neck

A total of 165 patients with tumours of the head and neck were irradiated via fields including the entire cervical portion of the spinal cord. Eight patients (4.8 per cent) developed mild reversible signs of radiation myelitis. Only one of these cases was found among the 44 patients who received a dose to the spinal cord of over 5 000 rad via fields of less than 16 cm in length; 7 cases were patients with Hodgkin's disease who were given up to 3 700 rad via mantle fields. A survey of previous reports on transverse spinal lesions provoked by irradiation revealed a possibility of overdosage in several cases, and dose tolerance limits mentioned previously should accordingly be applied with caution.     

The non-peptide neuropeptide Y Y1 receptor antagonist BIBP3226 blocks the [Leu31,Pro34]neuropeptide Y-induced modulation of alpha 2-adrenoceptors in the nucleus tractus solitarii of the rat

The potential blockade of the neuropeptide Y (NPY) Y1 receptor agonist [Leu31,Pro34]NPY-induced modulation of the characteristics of alpha 2-adrenoceptor agonist [3H]p-aminoclonidine binding sites by a selective non-peptide NPY Y1 receptor antagonist BIBP3226, was studied in the nucleus tractus solitarii of the rat by means of quantitative receptor autoradiography. [Leu31,Pro34]NPY at a concentration of 10 nM significantly increased the Kd value of [3H]p-aminoclonidine binding sites in the nucleus tractus solitarii without influencing the Bmax, suggesting the existence of an antagonistic modulation by NPY Y1 receptors of alpha 2-adrenoceptors in the nucleus tractus solitarii. BIBP3226 at 100 nM fully blocked the [Leu31,Pro34]NPY-induced increase in Kd of the [3H]p-aminoclonidine binding sites. The present results therefore provide evidence, by use of a NPY Y1 receptor antagonist, for the existence of a NPY Y1/alpha 2 receptor interaction in the nucleus tractus solitarii.     

D1 dopamine receptor binding and mRNA levels are not altered after neonatal 6-hydroxydopamine treatment: evidence against dopamine-mediated induction of D1 dopamine receptors during postnatal development

The role of dopaminergic innervation on the postnatal developmental expression of D1 dopamine receptors was investigated. Bilateral destruction of dopamine-containing neurons was achieved by treating rats intracisternally with 6-hydroxydopamine (6-OHDA) on postnatal day 3, and rats were killed on day 21. To ensure effective reduction of D1 receptor activation by residual dopamine, a group of 6-OHDA-lesioned rats was given twice daily injections of the D1 receptor antagonist SCH-23390, from day 4 to 20. D1 dopamine receptor binding was assessed in the caudate-putamen, nucleus accumbens, and olfactory tubercle by quantitative autoradiographic analysis of [3H]SCH-23390 binding. In addition, the relative amount of D1A receptor mRNA was assessed by in situ hybridization of a 35S-labeled riboprobe. In the developing rats, neither the amount of [3H]SCH-23390 binding nor the amount of D1A receptor mRNA was altered by 6-OHDA lesioning followed by chronic treatment with SCH-23390. Thus, bilateral destruction of dopamine-containing neurons and treatment with SCH-23390 in neonatal rats did not interfere with the developmental expression of D1 receptors or alter the levels of mRNA that code for this receptor protein. Treatment of intact rats with SCH-23390 from postnatal day 4 to 20 also did not alter [3H]SCH-23390 binding or levels of D1 receptor mRNA. However, adult rats treated chronically with SCH-23390 exhibited increased [3H]SCH-23390 binding but did not show a significant change in D1 receptor mRNA levels.     

Antibodies against pneumococcal C-polysaccharide are not protective

The ability of antibodies against C-polysaccharide (C-Ps) to protect against experimental pneumococcal infection was examined in a mouse model. No protection against types 6A and 14 pneumococcal infection could be demonstrated neither with mouse monoclonal antibodies against C-Ps, specific for phosphorylcholine (PC) or for C-Ps backbone, nor for polyclonal rabbit immunsera against C-Ps. The monoclonal antibody with PC-specificity was protective against infection with type 27 pneumococcus, that has PC as part of its capsular polysaccharide. Type-specific mono- and polyclonal antibodies were highly protective against infection with the homologous type. We conclude that no species-specific protection can be achieved against intraperitoneal Streptococcus pneumoniae infection with optimally capsulated bacteria in outbred mice by passive immunization with antibodies to C-Ps.