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21.
Introduction : Hypertrophic scar is a devastating sequel to burns and other tangential skin injuries. It follows deep dermal injuries and does not occur after superficial injuries. Nitric oxide (NO) plays many important roles in wound healing from inflammation to scar remodeling. Studies have shown that expression of nitric oxide synthase and nitric oxide production are decreased in human hypertrophic scar. However little is known about NO involvement in the early stages of hypertrophic scarring, because of the lack of an animal model. It was recently reported that the female red Duroc pig (FRDP) makes thick scar, which is similar to human hypertrophic scar. We hypothesized that NO production in wounds on the female, red Duroc pig is similar to that of human hypertrophic scar and that NO involvement in deep wounds is different from that in superficial wounds. Methods : Superficial (0.015” to 0.030”) and deep (0.045” to 0.060”) wounds were created on the backs of four FRDPs. Biopsies were collected at weeks 1.5, 4, 8 and 21 post wounding including samples of uninjured skin. Nitric oxide levels were measured with the Griess reaction assay and normalized with tissue protein level. Results : Superficial wounds healed with an invisible scar whereas the deep wounds healed with scar resembling mild hypertrophic scar. The thickness of the scars from the deep wounds was significantly greater than uninjured skin and healed superficial wounds (p < 0.01). NO levels were increased at 1.5 weeks in deep wounds compared to superficial wounds and uninjured skin (p < 0.05). At 8 weeks, NO levels in deep wounds had returned to the level of uninjured tissue and superficial wounds. By 21 weeks, NO levels had decreased significantly when compared to superficial wounds (p < 0.01). There were no differences in NO levels between uninjured skin and superficial wounds at any time point (p > 0.05). Conclusions : NO production is similar in late, deep wounds on the female, red Duroc pig to that reported in the literature for human hypertrophic scar further validating this animal model. NO production is quite different after deep wounds as compared to superficial wounds in the FRDP. Early elevation in nitric oxide production might account for excessive inflammation in deep wounds that become thick scars in the FRDP. Nitric oxide regulators and effects at early stages of scar formation should be elucidated further and the FRDP appears to be a useful model. 相似文献
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L Corey W E Stamm P M Feorino J A Bryan S Weseley M B Gregg K Solangi 《The New England journal of medicine》1975,293(25):1273-1278
Eleven of 40 patients in a hemodialysis unit had clinical or biochemical evidence of hepatitis during a five-week period. The clinical disease was mild, being limited solely to dialysis patients. Epidemiologic investigation indicated that the incubation period was between 17 and 35 days and that 10 of 11 patients had been exposed to a single venous-pressure monitor before onset. Dried blood and evidence of blood reflux up the venous-pressure gauge suggested that cross-contamination of the blood of successive patients probably resulted in transmission of disease. No association with the hepatitis B surface antigen or anti-hepatitis B antibody was demonstrated, but 10 of the 11 patients with elevated transaminase levels had evidence of recent exposure, to Epstein-Barr virus as manifested either by Ox-cell hemolysin titers or rises in titers to viral capsid antigen. 相似文献
24.
25.
Determination of optimal cryoprotectants and procedures for their addition and removal from human spermatozoa 总被引:9,自引:7,他引:9
The objective was to test the hypothesis that the optimal cryoprotective
agent for cryopreservation of human spermatozoa would be a solute for which
cells have the highest plasma membrane permeability, resulting in the least
amount of volume excursion during its addition and removal. To test this
hypothesis, theoretical simulations were performed using membrane
permeability coefficients to predict optimal procedures for the addition
and removal of a cryoprotectant. Simulations were performed using data from
four different cryoprotectants: (i) glycerol, (ii) dimethyl sulphoxide,
(iii) propylene glycol and (iv) ethylene glycol. Thermodynamic formulations
were applied to determine approaches for the addition and removal of 1 M
and 2 M final concentrations of cryoprotectant, allowing the spermatozoa to
maintain a cell volume within their osmotic tolerance limits. Based on
these data, ethylene glycol was predicted to be optimal for minimizing
volume excursions among the solutes evaluated. These predictions were then
experimentally tested using glycerol as the control cryoprotectant and
ethylene glycol as the experimental cryoprotectant. The results indicate
that there was a higher (P < 0.05) recovery of motile spermatozoa after
cryopreservation when using 1 M ethylene glycol than with 1 M glycerol,
supporting the hypothesis that use of the cryoprotectant for which the cell
has the highest permeability will result in higher cell survival.
相似文献
26.
Gregg D. Phillips Russell A. Whitehead David R. Knighton 《Developmental dynamics》1991,192(3):257-262
The object of this study was to examine the initiation and pattern of capillary growth associated with wound healing. Collagen sponges were implanted subcutaneously in the hind limbs of adult male rats to stimulate the formation of granulation tissue. Blood vessels of the hind limbs of euthanized rats were perfused with Mercox (an acrylic monomer) via the abdominal aorta at selected periods of time following sponge implantation. When the perfusate was completely cured, the sponge and parajacent tissues were excised and subsequently macerated by alternating immersion in 40% KOH and distilled water. Cast replicas of the vascular lumina were coated with gold and imaged by scanning electron microscopy. At 6 hr, punctate depressions at the periphery of the replicas of vein and venule lumina were noted. The depressions represented sites of leukocyte margination. By 24 hr, the depressions increased numerically, indicating a great increase in the sites of leukocyte margination. The number of these depressions decreased by 48 hr. Concomitantly, the depressions representing endothelial cell nuclei became more pronounced, indicating nuclear hypertrophy of these cells. In addition, capillary bud formation was initiated. At 72 hr, capillary buds were quite apparent and arose solely from venules. Between 7 and 14 days, replicas of capillary lumina were longer and formed an elaborate network, presumably by end-to-end, side-to-side, and end-to-side anastomoses. The network was formed circumferential to the sponge and then capillary sprouts entered the sponge's interstitial spaces. 相似文献
27.
Donor insemination: Dutch parents' opinions about confidentiality and donor anonymity and the emotional adjustment of their children 总被引:1,自引:4,他引:1
Brewaeys A; Golombok S; Naaktgeboren N; de Bruyn JK; van Hall EV 《Human reproduction (Oxford, England)》1997,12(7):1591-1597
Results from a comparative study investigating 38 donor insemination (DI)
Dutch families with 4-8 year old children are presented. The aims of this
study were to investigate parents' opinions on the issues of
confidentiality and donor anonymity, to assess the emotional development of
the children, and to examine in DI families the association between secrecy
with regard to the use of a donor and the emotional adjustment of the
children. The DI families were compared to families with a child conceived
by in-vitro fertilization (IVF) and to families with a naturally conceived
child. Secrecy appeared to be associated with DI and not with IVF: 74% of
the DI parents intended not to inform the child about the way in which
she/he was conceived, whereas none of the IVF parents intended to keep the
secret. Only one set of DI parents and two sets of IVF parents had actually
told the child. As to donor anonymity, a spread of opinions appeared among
DI parents; 57% preferred an anonymous donor, 31% would have liked non-
identifying information about the donor, 9% preferred the donor's identity
to be registered and 3% remained unsure. Parents' major concern was to know
more about the medical/genetic background of the donor. Mothers and fathers
in the DI families differed in their opinions concerning the issues of
confidentiality and donor anonymity: fathers, more often than mothers, were
secretive with regard to the use of a donor and husbands, more often than
their wives, were in favour of donor anonymity. With regard to the
emotional development of the children, more emotional/behavioural problems
were revealed among DI children than among children who were naturally
conceived. No association was found between secrecy and the
emotional/behavioural adjustment of the children.
相似文献
28.
Expression of CD44 in effusions of patients diagnosed with serous ovarian carcinoma – diagnostic and prognostic implications 总被引:2,自引:0,他引:2
Berner HS Davidson B Berner A Risberg B Kristensen GB Trope CG Van de Putte G Nesland JM 《Clinical & experimental metastasis》2000,18(2):197-202
CD44 is a family of cell adhesion molecules involved in a variety of cellular functions. The present study analysed the expression
of two CD44 isoforms in serous effusions of patients diagnosed with ovarian carcinoma and corresponding primary and metastatic
lesions. Fifty-eight effusions, 23 primary ovarian tumours, and 44 metastatic lesions were studied for protein expression
of CD44s and v3-10 using immunohistochemistry. Results were correlated with clinical parameters. CD44v3-10 was seen in carcinoma
cells in the majority of cases at all sites. Malignant effusions showed an up-regulation of CD44s compared to both primary
tumours and metastatic solid lesions. Mesothelial cells frequently expressed CD44s, but were rarely immunoreactive for v3-10.
CD44s immunoreactivity in cancer cells in effusions was significantly more often observed in patients with FIGO stage 3 than
in stage 4 patients (P = 0.045). Staining results did not correlate with age, effusion site, metastatic site, tumour grade or residual tumour mass
after initial surgery. Likewise, comparison of overall and disease-free survival with expression of the CD44 isoforms studied
did not reveal any statistically significant associations. The up-regulation in CD44 levels in effusions, primarily in stage
3 disease, suggests that adhesion of ovarian carcinoma cells to mesothelium may be regulated at the level of CD44s expression,
and provides further evidence of phenotypic alteration in the transition from primary tumour cell clones to effusions. The
similar expression profile of CD44 in carcinoma cells in peritoneal and pleural effusions supports our previous observations
and the hypothesis that carcinoma cells in peritoneal effusions are truly metastatic.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
29.