Expression of contact, a new zebrafish DVR member, marks mesenchymal cell lineages in the developing pectoral fins and head and is regulated by retinoic acid

Available data indicate that heat shock proteins act as chaperones under non-stress conditions by assisting in: (1) the folding of newly synthesized proteins, (2) the intracellular translocation of proteins, and (3) the function of other proteins. As we gain additional information concerning cellular physiology, we may find that heat shock proteins play a key role in many additional cellular functions. When cells experience thermal or chemical stress, heat shock proteins take on a new role, conserved from bacteria to humans, of protecting cells from the detrimental effects of stress. This latter role takes on added significance for the embryo in which the developmental program must be read linearly, with little opportunity to cycle backward to complete a missed segment of the program. Although circumstantial evidence clearly implicates heat shock proteins in protecting embryos from thermal stress, definitive evidence is still lacking. The challenge for the future is to obtain such definitive data. Ideally, such information will lead to new therapeutic paradigms that will afford protection to the human embryo/fetus exposed to thermal/chemical stress.     

Fluorescence histochemical techniques for catecholamines as tools in neurobiology

Formaldehyde-induced and glyoxylic-acid-induced fluorescence histochemistry permits the tissue localization of catecholamines in the central nervous system (CNS) and peripheral nervous system (PNS), and in culture. Counterstains such as ethidium bromide provide excellent background identification of specific innervated regions in both the CNS and the periphery. Use of fluorescence histochemistry with immunocytochemistry can elucidate catecholamine-peptide relationships. Gelatin-ink perfusion used with fluorescence histochemistry permits the investigation of neuro-vascular relationships and documentation of vascular and parenchymal compartmentation of innervation. Combined use of fluorescence histochemistry and retrograde tracing methods demonstrates the specific cellular sources of innervation of target regions. Micropunch neurochemical analysis provides quantitative data for correlation with fluorescence histochemistry within a target region of innervation, and micro-spectrofluorometric analysis provides a semi-quantitative evaluation of the amount of fluorophore within a target region or within specific subcellular compartments such as the cell body or terminals.     

Blood pressure changes during short-term fluoxetine treatment

PURPOSE: To evaluate the potential diagnostic role of mediastinal sonography in patients with cystic fibrosis (CF), we screened the mediastinum of adult CF patients with and without signs of infection and healthy controls. METHODS: Fifty-four consecutive adult patients with CF and 53 healthy volunteers underwent high-resolution mediastinal sonography. The paratracheal region and aorticopulmonary window of each subject were examined for lymph nodes. Each patient was screened for clinical signs of infection. RESULTS: Lymph nodes were detectable in the mediastinum of 39 of 50 CF patients (78%); the mean total lymph node volume was 1.5 +/- 1.7 cm3. Lymph nodes were detectable in the mediastinum of 31 of 50 controls (62%); the mean total lymph node volume in this group was 0.3 +/- 0.3 cm3 (p < 0.001). In the 30 CF patients with signs of infection, the mean total lymph node volume was larger (2.0 +/- 1.8 cm3) than in the 20 CF patients without signs of infection (0.7 +/- 0.9 cm3; p = 0.002). CONCLUSIONS: These results indicate that lymph node volume determination by high-resolution mediastinal sonography may help assess inflammatory activity in patients with CF.     

Gene structure of the human MET proto-oncogene

By direct sequencing of cosmids using primers designed from the known cDNA sequence, we identified 19 exons in the human MET proto-oncogene, and sequenced the corresponding 5' and 3' exon-intron junctions. By homology search in the database of the Washington University Genome Sequence Center (GSC), we identified one additional exon. These 20 exons, together with a previously reported exon, bring the total exon number of MET to 21. Oligonucleotide primers were designed to amplify each exon and adjacent intronic sequences to permit examination of each exon for mutations. By restriction mapping, we assembled a 110 kb genomic contig that covered almost the entire MET proto-oncogene. This information is relevant for the screening of recently reported mutations of the MET gene which cause hereditary papillary renal carcinomas and for the search for additional mutations of the same gene which may play a role in the pathogenesis of common human carcinomas including carcinomas of the breast, ovary and pancreas.     

Architecture of the yeast cell wall. Beta(1-->6)-glucan interconnects mannoprotein, beta(1-->)3-glucan, and chitin

In a previous study (Kollár, R., Petráková, E., Ashwell, G., Robbins, P. W., and Cabib, E. (1995) J. Biol. Chem. 270, 1170-1178), the linkage region between chitin and beta(1-->3)-glucan was solubilized and isolated in the form of oligosaccharides, after digestion of yeast cell walls with beta(1-->3)-glucanase, reduction with borotritide, and subsequent incubation with chitinase. In addition to the oligosaccharides, the solubilized fraction contained tritium-labeled high molecular weight material. We have now investigated the nature of this material and found that it represents areas in which all four structural components of the cell wall, beta(1-->3)-glucan, beta(1-->6)-glucan, chitin, and mannoprotein are linked together. Mannoprotein, with a protein moiety about 100 kDa in apparent size, is attached to beta(1-->6)-glucan through a remnant of a glycosylphosphatidylinositol anchor containing five alpha-linked mannosyl residues. The beta(1-->6)-glucan has some beta(1-->3)-linked branches, and it is to these branches that the reducing terminus of chitin chains appears to be attached in a beta(1-->4) or beta(1-->2) linkage. Finally, the reducing end of beta(1-->6)-glucan is connected to the nonreducing terminal glucose of beta(1-->3)-glucan through a linkage that remains to be established. A fraction of the isolated material has three of the main components but lacks mannoprotein. From these results and previous findings on the linkage between mannoproteins and beta(1-->6)-glucan, it is concluded that the latter polysaccharide has a central role in the organization of the yeast cell wall. The possible mechanism of synthesis and physiological significance of the cross-links is discussed.     

Regulation of monocyte IL-10 synthesis by endogenous IL-1 and TNF-alpha: role of the p38 and p42/44 mitogen-activated protein kinases

IL-10 is an anti-inflammatory cytokine with potent immunomodulatory effects, including inhibition of cytokine production. However, regulation of monocyte IL-10 production is poorly understood. In this report we have investigated the mechanisms of LPS-induced IL-10 production by human peripheral blood monocytes and demonstrate that IL-10 synthesis is uniquely dependent on the endogenous proinflammatory cytokines IL-1 and/or TNF-alpha. LPS signal transduction in monocytes has been shown to involve activation of the p38 and p42 mitogen-activated protein kinase (MAPK) cascades. The results in this paper indicate that inhibition of p38 MAPK potently inhibited the production of IL-10, IL-1beta, and TNF-alpha, whereas blockade of the p42/44 MAPK pathway, while partially inhibiting TNF-alpha and IL-1beta production, had no effect on monocyte secretion of IL-10. Furthermore, neither the inhibition of monocyte TNF-alpha induced by IL-10 nor the stimulation of soluble TNF receptor production was affected by inhibition of the p42/44 MAPK pathway, suggesting that this signaling event is not involved in either monocyte production of or anti-inflammatory responses to IL-10. These data raise the interesting possibility that proinflammatory TNF-alpha-mediated effects may be selectively blocked without modulating the induction or the response to IL-10, whereas the signaling events associated with the anti-inflammatory events induced by IL-10 remain to be elucidated.     

A new tool for studying the molecular architecture of the fungal cell wall: one-step purification of recombinant trichoderma beta-(1-6)-glucanase expressed in Pichia pastoris

We assessed the anesthetic properties of helium and neon at hyperbaric pressures by testing their capacity to decrease anesthetic requirement for desflurane using electrical stimulation of the tail as the anesthetic endpoint (i.e., the minimum alveolar anesthetic concentration [MAC]) in rats. Partial pressures of helium or neon near those predicted to produce anesthesia by the Meyer-Overton hypothesis (approximately 80-90 atm), tended to increase desflurane MAC, and these partial pressures of helium and neon produced convulsions when administered alone. In contrast, the noble gases argon, krypton, and xenon were anesthetic with mean MAC values of (+/- SD) of 27.0 +/- 2.6, 7.31 +/- 0.54, and 1.61 +/- 0.17 atm, respectively. Because the lethal partial pressures of nitrogen and sulfur hexafluoride overlapped their anesthetic partial pressures, MAC values were determined for these gases by additivity studies with desflurane. Nitrogen and sulfur hexafluoride MAC values were estimated to be 110 and 14.6 atm, respectively. Of the gases with anesthetic properties, nitrogen deviated the most from the Meyer-Overton hypothesis. Implications: It has been thought that the high pressures of helium and neon that might be needed to produce anesthesia antagonize their anesthetic properties (pressure reversal of anesthesia). We propose an alternative explanation: like other compounds with a low affinity to water, helium and neon are intrinsically without anesthetic effect.     

Driveway crush injuries in young children: a highly lethal, devastating, and potentially preventable event

BACKGROUND/PURPOSE: The aim of this study was to investigate driveway-related injuries in children, identify associated risk factors, and evaluate outcome compared with other mechanisms of blunt trauma. METHODS: A 6-year review (1991 to 1996) of pediatric (age less than 18 years) pedestrian injuries treated at two urban trauma centers was conducted: one regional pediatric trauma center and one level I trauma center with pediatric commitment. Five hundred twenty-seven children injured in pedestrian accidents were identified from the trauma registry; 51 children (10%) sustained traumatic injuries as a result of being struck in their driveway. Data are reported as mean +/- SEM. RESULTS: Children less than 5 years of age (n = 41) had an injury severity score (ISS) of 12.3+/-2.3, 15 (37%) sustained closed head injury, 13 (37%) had torso trauma, 19 (46%) skeletal trauma, and eight (20%) died. Children > or = 5 years old (n = 10) had an ISS of 10.7+/-2.4, three (30%) sustained closed head injury, four (40%) torso trauma, six (60%) skeletal trauma, and none died. In contrast, all other pediatric pedestrian accidents analyzed over the same time period had a mortality rate of only 2% (11 of 476). CONCLUSIONS: Pediatric driveway trauma carries a significant risk of head injury and a 10-fold increase in mortality in children under 5 years of age when compared with all other pediatric pedestrian accidents. More emphasis must be placed on injury prevention and public education to prevent this devastating mechanism of injury in these young, vulnerable children.