Body protein does not vary despite seasonal changes in fat in the White Stork Ciconia ciconia

To understand how a large soaring bird, the White Stork Ciconia ciconia , copes with energy constraints, we compared changes in body mass in 14 captive adult storks with the body composition of 12 free-ranging adult storks found dead from accidents. The captive storks, already in an enclosure for several years, were fed ad libitum . They were weighed daily for 1.53.5 years using an automatic device. The bodies of the accidentally killed storks were analysed to determine total water, lipid, protein and ash contents, and to assess the biochemical composition of certain organs. Females were on average 20% lighter and 24% smaller than males, but the body mass of the sexes varied in parallel throughout the year. Body mass peaked in December and January (2530% above minimal body mass), due essentially to large fat stores in subcutaneous and abdominal adipose tissues. Body mass and body lipid rapidly decreased from February to June, whether the storks reared chicks successfully or not, and remained minimal for a few days into July. In contrast to birds using flapping flight, no variation in body protein or pectoral muscle protein was observed while breeding, even though the moult occurred then, nor in August, before the time when wild storks migrate. An endogenous regulation of body fuels is discussed.     

Elevation of glutathione in phenylalanine mustard-resistant murine L1210 leukemia cells

Murine L1210 leukemia cells resistant to the antineoplastic agent L-phenylalanine mustard have a 1.5-2.0-fold elevation in their cellular GSH and GSSG content as compared to drug-sensitive cells. Cellular uptake of L-[U-14C]cystine and its incorporation into GSH of the resistant tumor are correspondingly elevated. Synthesis of gamma-glutamylcysteine, GSH, and GSSG is elevated 1.5-2.0-fold in cell-free preparations of the resistant tumor. This increased synthesis of GSH is attributed to increased cellular content (1.6-fold) of gamma-glutamylcysteine synthetase. GSH synthetase activity is equivalent in both drug-sensitive and -resistant cells. Investigation into the hydrolysis of selected peptides by cell-free preparations of both sensitive and resistant tumors suggest that aminopeptidase M participates in the formation of L-cysteine from L-Cys-Gly. This is supported by the observation that these preparations readily degrade L-Leu-p-nitroanilide and L-Ala-L-Ala-L-Ala, known substrates for aminopeptidase M, but not dipeptidase. The failure of the tumors to degrade Gly-D-Ala, a dipeptidase substrate, and the marked inhibition of L-Ala-Gly, L-Cys-Gly, and L-Ala-L-Ala-L-Ala hydrolysis by Bestatin further support a role for aminopeptidase M in the generation of L-cysteine from L-Cys-Gly. These results suggest that the drug-resistant tumor cell has developed an efficient mechanism for maintenance of elevated GSH which involves both gamma-glutamyl transpeptidase-initiated catabolism of GSH to cysteine and its reutilization by gamma-glutamylcysteine synthetase.     

Changes in airway resistance induced by nasal inhalation of cold dry, dry, or moist air in normal individuals

Fontanari, Pierre, Henri Burnet, Marie CarolineZattara-Hartmann, and Yves Jammes. Changes in airway resistanceinduced by nasal inhalation of cold dry, dry, or moist air in normalindividuals. J. Appl. Physiol. 81(4):1739-1743, 1996.Nasopulmonary bronchomotor reflexes elicited bymechanical or irritant stimulation of the nose have been described inanimals and asthmatic patients. However, few studies were devoted tothe consequences of nasal breathing of cold and dry air or of only dryor only moist air on the bronchomotor control in normal individuals.The present study reported changes in interruption resistance (Rint)measured during eupneic breathing of moderately cold (4 or10°C) and dry [0.3% relative humidity (RH)] airor of room air at 23°C that is either dry (0.3% RH) or moist (97%RH). Nasal inhalation of cold (4°C) dry air or of only dryair significantly increased baseline Rint value (17 and 21%,respectively) throughout the 15-min test periods. The response to cold was significantly accentuated when the air temperature was lowered to 10°C (42%). After nasal anesthesia orinhalation of a cholinergic antagonist, cold air did not induce achange in Rint. Nasal inhalation of moist room air had no effect. No Rint changes were measured during oral breathing of the three testagents. It is concluded that the activation of cold receptors orosmoreceptors in the nasal mucosa induces protective bronchoconstrictor responses in normal individuals.

     

Antigenic, functional, and molecular genetic studies of human natural killer cells and cytotoxic T lymphocytes not restricted by the major histocompatibility complex

Cytotoxicity not restricted by the major histocompatibility complex (MHC) is mediated by two distinct types of lymphocyte: natural killer (NK) cells and non-MHC-restricted cytotoxic T lymphocytes (CTL). These two types of cytotoxic lymphocytes can be distinguished by antigenic phenotype, function, and molecular genetic studies. In human peripheral blood, NK cells are identified by expression of the Leu-19 and/or CD16 cell surface antigens, and lack of CD3/T cell antigen receptor (Ti) complex expression (i.e., CD3-,Leu-19+). Peripheral blood non-MHC-restricted CTL express both CD3 and Leu-19 (i.e., CD3+, Leu-19+, referred to as Leu-19+ T cells). Both Leu-19+ T cells and NK cells lyse "NK-sensitive" hematopoietic tumor cell targets, such as K562, without deliberate immunization of the host. However, most "NK activity" in peripheral blood is mediated by NK cells, because they are usually more abundant and more efficient cytotoxic effectors than Leu-19+ T cells. The cytolytic activity of both NK cells and Leu-19+ T cells against hematopoietic targets was enhanced by recombinant interleukin 2 (rIL 2). NK cells, but not peripheral blood Leu-19+ T cells, were also capable of lysing solid tumor cell targets after short-term culture in rIL 2. Southern blot analysis of NK cells revealed that both the T cell antigen receptor beta-chain genes and the T cell-associated gamma genes were not rearranged, but were in germ-line configuration. These findings indicate that NK cells are distinct in lineage from T lymphocytes and do not use the T cell antigen receptor genes for target recognition.(ABSTRACT TRUNCATED AT 250 WORDS)     

RNF185 Is a Novel E3 Ligase of Endoplasmic Reticulum-associated Degradation (ERAD) That Targets Cystic Fibrosis Transmembrane Conductance Regulator (CFTR)

In the endoplasmic reticulum (ER), misfolded or improperly assembled proteins are exported to the cytoplasm and degraded by the ubiquitin-proteasome pathway through a process called ER-associated degradation (ERAD). ER-associated E3 ligases, which coordinate substrate recognition, export, and proteasome targeting, are key components of ERAD. Cystic fibrosis transmembrane conductance regulator (CFTR) is one ERAD substrate targeted to co-translational degradation by the E3 ligase RNF5/RMA1. RNF185 is a RING domain-containing polypeptide homologous to RNF5. We show that RNF185 controls the stability of CFTR and of the CFTRΔF508 mutant in a RING- and proteasome-dependent manner but does not control that of other classical ERAD model substrates. Reciprocally, its silencing stabilizes CFTR proteins. Turnover analyses indicate that, as RNF5, RNF185 targets CFTR to co-translational degradation. Importantly, however, simultaneous depletion of RNF5 and RNF185 profoundly blocks CFTRΔF508 degradation not only during translation but also after synthesis is complete. Our data thus identify RNF185 and RNF5 as a novel E3 ligase module that is central to the control of CFTR degradation.     

Anoctamin 1 dysregulation alters bronchial epithelial repair in cystic fibrosis

Cystic fibrosis (CF) airway epithelium is constantly subjected to injury events due to chronic infection and inflammation. Moreover, abnormalities in CF airway epithelium repair have been described and contribute to the lung function decline seen in CF patients. In the last past years, it has been proposed that anoctamin 1 (ANO1), a Ca^2 +-activated Cl^? channel, might offset the CFTR deficiency but this protein has not been characterized in CF airways. Interestingly, recent evidence indicates a role for ANO1 in cell proliferation and tumor growth. Our aims were to study non-CF and CF bronchial epithelial repair and to determine whether ANO1 is involved in airway epithelial repair. Here, we showed, with human bronchial epithelial cell lines and primary cells, that both cell proliferation and migration during epithelial repair are delayed in CF compared to non-CF cells. We then demonstrated that ANO1 Cl^? channel activity was significantly decreased in CF versus non-CF cells. To explain this decreased Cl^? channel activity in CF context, we compared ANO1 expression in non-CF vs. CF bronchial epithelial cell lines and primary cells, in lung explants from wild-type vs. F508del mice and non-CF vs. CF patients. In all these models, ANO1 expression was markedly lower in CF compared to non-CF. Finally, we established that ANO1 inhibition or overexpression was associated respectively with decreases and increases in cell proliferation and migration. In summary, our study demonstrates involvement of ANO1 decreased activity and expression in abnormal CF airway epithelial repair and suggests that ANO1 correction may improve this process.     

Specificity of the rapid rK39 antigen-based immunochromatographic test Kalazar Detect(r) in patients with cutaneous leishmaniasis in Brazil

The aim of this study was to evaluate the specificity of a rapid immunochromatographic test that was developed to detect antibodies against the rK39 antigen for the diagnosis of visceral leishmaniasis (VL). This evaluation was performed using sera from patients with a confirmed diagnosis of active cutaneous leishmaniasis. The sera from 272 patients with a confirmed diagnosis of localised cutaneous leishmaniasis (CL) who resided in an area endemic for Leishmania braziliensis in Brazil were obtained before the initiation of antileishmanial treatment. Kalazar Detect^(r)(InBios, Seattle, WA) recombinant K39 antigen-based immunochromatographic strips were used according to the manufacturer''s instructions. The test results were evaluated independently by two examiners in sequential order. The positive controls for the test included five serum samples from five patients with parasitologically confirmed diagnosis of VL caused by Leishmania infantum in Brazil. Overall, 100% of the samples obtained from patients with CL were negative, confirming the absence of a serological cross-reaction for individuals with cutaneous disease when these patients were evaluated using the rapid test. The lack of a cross-reaction in patients who were infected by parasites of the same genus highlights the specificity of the rK39 antigen for the diagnosis of VL in areas with the sympatric circulation of L. braziliensis and L. infantum.