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51.
Leal Filho MB Morandin RC de Almeida AR Cambiucci EC Borges G Gontijo JA Metze K 《Neuroscience letters》2005,373(2):165-170
There are reports describing both provocation and inhibition of neurogenic pulmonary edema by anesthetic drugs. Therefore, we compared the effect of two types of anesthesia on the formation of neurogenic pulmonary edema in rats with balloon-induced acute spinal cord injury. Animals with sham procedure (group 1) were anesthesized by intraperitoneal sodium pentobarbital. In the experimental groups, rats were submitted to acute spinal cord lesion by insufflations of a balloon in the epidural space at T8 for 1 min (group 3 under i.p. sodium pentobarbital and group 2 under i.p. xylazine-ketamine anesthesia). In rats with pentobarbital anesthesia, systolic blood pressure doubled the baseline value during compression, whereas this effect was less pronounced in the ketamine-xylazine group. The pulmonary index (100 x wet lung weight/body weight) was 0.395 (+/-0.018) in sham-operated rats, rose to 0.499 (+/-0.060) in group 2, and was maximum under pentobarbital anesthesia (0.639+/-0.14; p=0.0018). Histologic examination of the spinal cord showed parenchymal ruptures and acute hemorrhage. Comparison of the pulmonary index with histologic slides of lung parenchyma revealed that relevant intra-alveolar edema occurred only for index values above 0.55. On electron microscopy, endothelial alterations, and damage of the alveolar lining cells were found. Our study indicates that neurogenic pulmonary edema caused by spinal cord injury is less pronounced in rats under xylazine-ketamine anesthesia, when compared with pentobarbital. 相似文献
52.
Tania C. Araújo-Jorge Maria de Nazareth Leal de Meirelles Lourdes Isaac 《Parasitology research》1990,76(7):545-552
We report that alpha-2-macroglobulin (A2M), the physiologically important plasma protease inhibitor and suspected immunomodulator, alters the functional ability of murine resident peritoneal macrophages (RM) to ingest and kill the infective trypomastigote stage ofTrypanosoma cruzi, the aetiological agent of Chagas' disease. Treatment of RM with 500 g/ml A2M for 30 min enhanced the uptake of trypomastigotes, epimastigotes, and amastigotes by 125%, 46%, and 300%, respectively. The same treatment also increased the phagocytosis of sheep erythrocytes opsonized with complement and IgG as well as of galactosylated asialoerythrocytes. After 60–90 min parasite-cell interaction, epi-and amastigotes were killed by the RM, whereas the infection with trypomastigotes was controlled only after 24 h. Other protease inhibitors, bovine serum albumin, and LPS showed no such effect. The production of hydrogen peroxide was not affected by A2M treatment, but the ultrastructural aspects showed trypomastigote damage and enhancement of macrophage membrane ruffling, indicative of macrophage activation. These results suggest that A2M has the ability to modulate, at least functionally, certain receptor-mediated endocytic pathways that, in concert with an activation of possibly oxygen-independent microbicidal mechanisms, could contribute to resistance against the parasite.Abbreviations A2M
alpha-2-macroglobulin
- F-A2M
fast A2M
- S-A2M
slow A2M
- RM
resident macrophages
- BT
bloodstream trypomastigotes
- EPI
epimastigotes
- AMA
amastigotes
- DMEM
Dulbecco's Modified Eagle Medium
- PBS
phosphate-buffered saline
- BSA
bovine serum albumin
- LPS
bacto lipopolysaccharide
- STI
sovoean trypsin inhibitor
- PPA
pepstatin A
- LPT
leupeptin
- PNT
1, 10-phenanthroline
- TLCK
N--tosy-L-lysine-chloromethylketone
- E
sheep erythrocyte
- aE
asialoerythrocyte
- Gal R
receptors for galactosylated particles 相似文献
53.
Leal GF Roberts E Silva EO Costa SM Hampshire DJ Woods CG 《Journal of medical genetics》2003,40(7):540-542
54.
55.
B lymphocytes secreting IgG linked to latent transforming growth factor- beta prevent primary cytolytic T lymphocyte responses 总被引:3,自引:0,他引:3
B lymphocytes secreting IgG linked to latent transforming growth factor
(TGF)-beta (IgG-TGF-beta) prevent cytolytic T lymphocyte (CTL) responses to
unrelated antigens in mixed lymphocyte cultures (MLC) so long as resting
resident macrophages and functional Fc receptors are present. This was
shown using IgG-secreting plaque-forming cells (PFC) to sheep erythrocytes
(SRBC) obtained from popliteal lymph nodes of mice injected repeatedly in
foot pads with SRBC. Remarkably, as few as approximately 300 PFC prevented
CTL responses of 5 x 10(5) normal syngeneic spleen cells in MLC.
Supranatants of short-term cultures of PFC also prevented CTL responses,
and suppression was prevented by eliminating or dissociating IgG and
TGF-beta present in supranatants or by antibody against active TGF-beta.
Furthermore, the latency- associated peptide of latent TGF-beta was
detected in approximately 10% of foci of IgG captured from single PFC,
indicating that at least some B lymphocytes secrete IgG-TGF-beta as a
complex. Resting resident macrophages (which do not produce latent
TGF-beta) and functional Fc receptors were required for suppression,
consistent with idea that IgG- TGF-beta is taken up through Fc receptors
for IgG and that active TGF- beta, cleaved from latent TGF-beta of the
complex, is delivered directly to potentially responding CTL. If CTL
responses in man are similarly regulated by B lymphocytes, then an ongoing
B cell response in patients with chronic viral infections or bearing
immunogenic cancers may prevent effective therapeutic vaccination.
相似文献
56.
57.
do Valle Matta MA Sales Alviano D dos Santos Silva Couceiro JN Nazareth M Meirelles L Sales Alviano C Angluster J 《Parasitology research》1999,85(4):293-299
The cell-surface expression of sialoglycoconjugate structures in wild-type Crithidia fasciculata and its TFRR1 drug-resistant mutant was analyzed with the aid of an influenza C virus strain, lectin, enzymatic treatment, and flow cytofluorimetry
analysis probed with fluorescein isothiocyanate-labeled (FITC) lectins. 9-O-Acetyl-N-acetyl neuraminic acid (Neu5,9Ac2) structures mediate influenza C virus cell-binding. The SAα2,3Gal and SAα2,6Gal sequences are specifically recognized by
Maackia amurensis (MAA) and Sambucus nigra (SNA) lectins, respectively. On the basis of these param- eters the TFRR1 mutant strain of C. fasciculata was found to contain exposed sialoglycoconjugates bearing Neu5,9Ac2 surface structures. After the removal of sialic acid residues by neuraminidase activity the marked increases in PNA (peanut
agglutinin)-mediated agglutinating activity showed that those acidic units on C. fasciculata cells were glycosidically linked to d-galactose. The bond involves SAα2,6Gal and SAα2,3Gal linkages as suggested by the use of FITC-SNA and FITC-MAA lectins, respectively.
Both SAα2,3Gal and SAα2,6Gal sequences were preferentially expressed by the TFRR1 mutant. The SAα2,6 linkage markedly predominated. In the TFRR1 mutant, but not in wild-type cells, two distinct populations of cells were distinguished by reactivity with FITC-SNA, one
of which was enriched with surface SAα2,6Gal sequences. These diverse findings suggest that sialoglycoconjugate structures
present on the flagellate surface may be associated with mutation and the cell growth cycle in C. fasciculata.
Received: 17 September 1998 / Accepted: 22 October 1998 相似文献
58.
Alison Severn Damo Xu Jacqueline Doyle Ludmila M. C. Leal Catherine A. O'Donnell Sara J. Brett David W. Moss Foo Y. Liew 《European journal of immunology》1993,23(7):1711-1714
Murine macrophages produce nitric oxide (NO) from L-arginine on stimulation with lipopolysaccharide (LPS), alone or with interferon-γ (IFN-γ). The effect of incubation of macrophages with low concentrations of LPS on NO synthesis on subsequent stimulation was investigated, using a murine macrophage cell line, J774, and peritoneal macrophages from CBA mice. Cells which had been incubated with LPS produced significantly lower amounts of NO, and expressed lower levels of NO synthase activity, following stimulation with IFN-γ and LPS, or with a high concentration of LPS. This effect was not reversed by tumor necrosis factor-α. The ability of CBA macrophages to kill the intracellular parasite Leishmania major was markedly reduced by pre-incubation with LPS. Reduced NO production by macrophages previously exposed to LPS is a manifestation of endotoxin tolerance, and may represent an important means of regulation of NO synthesis and thus a survival mechanism for intracellular parasites. 相似文献
59.
Das P Hai M Elcock C Leal SM Brown DT Brook AH Patel PI 《American journal of medical genetics. Part A》2003,(1):35-42
We describe the molecular analysis of three families with hypodontia involving primarily molar teeth and report two novel mutational mechanisms. Linkage analysis of two large families revealed that the hypodontia was linked to the PAX9 locus. These two families revealed missense mutations consisting of a glutamic acid substitution for lysine and a proline substitution for leucine within the paired domain of PAX9. A pair of identical twins affected with hypodontia in a third family demonstrated a 288-bp insertion within exon 2 that resulted in a putative frameshift mutation and a premature stop codon. The insertion was associated with the loss of 7-bp from exon 2. A block of 256-bp of sequence within the insertion was completely identical to downstream sequence from the second intron of the PAX9 gene. These studies extend the spectrum of mutations in PAX9 associated with hypodontia to include heretofore undescribed categories, including missense mutations. 相似文献
60.
Santos RL Wajid M Khan MN McArthur N Pham TL Bhatti A Lee K Irshad S Mir A Yan K Chahrour MH Ansar M Ahmad W Leal SM 《Human mutation》2005,26(4):396
Though many hearing impairment genes have been identified, only a few of these genes have been screened in population studies. For this study, 168 Pakistani families with autosomal recessive hearing impairment not due to mutations in the GJB2 (Cx26) gene underwent a genome scan. Two-point and multipoint parametric linkage analyses were carried out. Twelve families had two-point or multipoint LOD scores of 1.4 or greater within the transmembrane cochlear expressed gene 1 (TMC1) region and were subjected to further screening with direct DNA sequencing. Five novel putatively functional non-synonymous sequence variants, c.830A>G (p.Y277C), c.1114G>A (p.V372M), c.1334G>A (p.R445H), c.2004T>G (p.S668R), and c.2035G>A (p.E679K), were found to segregate within seven families, but were not observed in 234 Pakistani control chromosomes. The variants c.830A>G (p.Y277C), c.1114G>A (p.V372M), and c.1334G>A (p.R445H) occurred at highly conserved regions and were predicted to lie within hydrophobic transmembrane domains, while non-synonymous variants c.2004T>G (p.S668R) and c.2035G>A (p.E679K) occurred in extracellular regions that were not highly conserved. There is evidence that the c.2004T>G (p.S668R) variant may have occurred at a phosphorylation site. One family has the known splice site mutation c.536 -8T>A. The prevalence of non-syndromic hearing impairment due to TMC1 in this Pakistani population is 4.4% (95%CI: 1.9, 8.6%). The TMC1 protein might have an important function in K(+) channels of inner hair cells, which would be consistent with the hypothetical structure of protein domains in which sequence variants were identified. 相似文献