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351.
After harvest, cassava (Manihot esculenta Crantz) storage roots undergo rapid postharvest physiological deterioration, producing blue-brown discoloration in the vasculature due to the production of polyphenolics (mainly quinones and coumarins) by enzymes such as polyphenol oxidase (PPO). Here, we report the application of hen egg-white lysozyme (HEWL), a natural PPO inhibitor, in transgenic cassava to repress the symptoms of postharvest physiological deterioration. The HEWL-expressing transgenic plants had lower levels of the two main cassava coumarins tested, scopoletin and scopolin, compared with wild type. HEWL-expressing cassava also showed increased tolerance of oxidative stress. Overall, the lysozyme-PPO system proved to be functional in plants for repressing PPO-mediated commercial product browning.  相似文献   
352.
Although studies have demonstrated that trauma markedly alters the bone marrow immune responses, sex and age are crucial determinants under such conditions and have not been extensively examined. To study this, 21- to 27-day-old (premature), 6- to 8-wk-old (mature), and 20- to 24-mo-old (aged) male and female (proestrus) C3H/HeN mice were sham operated or subjected to trauma (i.e., midline laparotomy) and hemorrhagic shock (30 +/- 5 mmHg for 90 min) followed by fluid resuscitation. Twenty-four hours after resuscitation, bone marrow cells were harvested. Trauma-hemorrhage induced an increased number of the early pluripotent stem cell-associated bone marrow cell subsets (Sca1(+)CD34(-)CD117(+/-)lin(+/-)) in young mice. The CD117(+) proportion of these cell subsets increased in mature proestrus females, but not in males. Aged males displayed significant lower numbers of Sca1(+)CD34(-)CD117(+/-)lin(+/-) cells compared with young male mice. Trauma-hemorrhage also increased development of granulocyte/macrophage progenitor cells (CD11b(+)Gr-1(+)). Proliferative responses to granulocyte macrophage colony-stimulating factor were maintained in mature and aged proestrus females, but decreased in young mice and mature males. Augmented differentiation into monocyte/macrophage lineage in mature and aged proestrus females was observed and associated with the maintained release of TNF-alpha and IL-6. Conversely, increased IL-10 and PGE(2) production was observed in the male trauma-hemorrhage groups. Thus, sex- and age-specific effects in bone marrow differentiation and immune responses after trauma-hemorrhage occur, which are likely to contribute to the sex- and age-related differences in the systemic immune responses under such conditions.  相似文献   
353.
In a population based cohort study information on the consumption of alcohol was obtained from 95% of the 952 consecutive primigravidas who lived in the Dundee district and attended for antenatal care between May 1985 and April 1986. Before realising that they were pregnant more than 90% drank alcohol and 53% were cigarette smokers. During the first four months of pregnancy, however, the proportion of women drinking and smoking fell to 56% and 44%, respectively. Alcohol consumption of more than 120 g absolute alcohol/week (12 or more standard drinks) during pregnancy was related to shorter gestational age (-2·6 weeks), smaller head circumference (-18 mm), shorter (-21 mm) and lighter (-499 g) babies, and lower Apgar scores at five minutes (-0·4, all p<0·01). After adjustment for the effect of smoking, social class, mother''s size, and other confounding factors, however, an alcohol intake of more than 120 g/week was significantly related only to shorter gestational age (-2·0 weeks, p<0·001) and lower Apgar score at five minutes (-0·2, p<0·05). Alcohol intake in the region of 100-119 g/week was significantly related to smaller head circumference (-12 mm, p<0·05). Analysis by type of beverage consumed suggested that beer rather than wine or spirits was associated with a poorer outcome.As there was no detectable effect on pregnancy of alcohol consumption below 100 g/week, it is suggested that health education should be directed towards mothers who drink more than this amount.  相似文献   
354.
Summary Exuberant and subculturable calli could be induced from only hypocotyl and leaf segments of ca 4-month-old seedlings of Meconopsis simplicifolia cultured on Murashige & Skoog's medium supplemented with 10–6M kinetin + 10–5M -naphthalene acetic acid. Suspension cultures were initiated from the calli in a similar medium but with 10–5M 2,4-dichlorophenoxy acetic acid in place of -naphthalene acetic acid. In ca 80% of the suspension cultures somatic embryos differentiated freely (80–85%) as well as on the surface of small clumps of tissue (15–20%). Somatic embryos that developed beyond heart-shaped stage were transferred to agar-solidified Murashige & Skoog's medium free of growth substances. When maintained in 10 h light and 14 h dark the somatic embryos developed into plantlets bearing cauline leaves. From seed sowing to raising normal plantlets via callus required 28 weeks; on average 80 plantlets were obtained from one explant in three passages.Abbreviations 2,4-D 2,4-dichlorophenoxy acetic acid - FAA formalin-acetic acid-alcohol - GA3 gibberellic acid - Kn kinetin - MS Murashige & Skoog's medium (Murashige and Skoog 1962) - NAA -naphthalene acetic acid  相似文献   
355.
A primary objective of the large collaborative project entitled "Inflammation and the Host Response to Injury" was to identify leukocyte genes that are differentially expressed after two different types of injury in mouse models and to test the hypothesis that both forms of injury would induce similar changes in gene expression. We report here the genes that are expressed in white blood cells (WBCs) and in splenocytes at 2 h, 1 day, 3 days, and 7 days after burn and sham injury or trauma-hemorrhage (T-H) and sham T-H. Affymetrix Mouse Genome 430 2.0 GeneChips were used to profile gene expression, and the results were analyzed by dCHIP, BRB Array Tools, and Ingenuity Pathway Analysis (IPA) software. We found that the highest number of genes differentially expressed following burn injury were at day 1 for both WBCs (4,989) and for splenocytes (4,715) and at day 1 for WBCs (1,167) and at day 3 for splenocytes (1,117) following T-H. The maximum overlap of genes that were expressed after both forms of injury were at day 1 in WBCs (136 genes) and at day 7 in splenocytes (433 genes). IPA revealed that the cell-to-cell signaling, cell death, immune response, antiapoptosis, and cell cycle control pathways were affected most significantly. In summary, this report provides a database of genes that are modulated in WBCs and splenocytes at sequential time points after burn or T-H in mice and reveals that relatively few leukocyte genes are expressed in common after these two forms of injury.  相似文献   
356.
Although systemic interleukin-6 (IL-6) level is elevated, hepatocellular function is impaired and liver injury occurs after trauma-hemorrhage (T-H), it remains unknown whether a causal relationship exists between elevated IL-6 levels and liver injury after T-H. We hypothesized that IL-6 is causative in the development of hepatic dysfunction and injury after T-H. To examine this, adult male Sprague-Dawley rats underwent a 5-cm midline laparotomy and were subjected to hemorrhagic shock (blood pressure = 35 mmHg for approximately 90 min), followed by resuscitation (Ringer lactate, 4 times the shed blood volume). At 2, 5, and 24 h thereafter, blood samples were collected and the liver isolated and perfused for 60 min. Portal inflow pressure was measured, and perfusate samples were collected to measure IL-6, alanine aminotransferase (ALT), and lactate dehydrogenase (LDH) levels. A significant positive correlation between plasma levels of IL-6 and ALT and perfusate levels of IL-6 and LDH levels was observed. In a second series of experiments, rats were treated with immunoglobulin G (IgG) or antibodies against rat IL-6 (anti-IL-6) at the onset of resuscitation. At 5 h after resuscitation, anti-IL-6 treatment attenuated the T-H induced increases in plasma ALT and thromboxane B(2) (a thromboxane A(2) metabolite) levels, and bile flow was normalized to sham levels. Perfusion of livers from normal rats with IL-6 did not alter portal pressure; however, perfusion of a stable thromboxane A(2) analog dose dependently increased portal pressure. Thus IL-6 plays a significant role in the induction of hepatic dysfunction and liver injury after T-H that appears to be in part mediated by increased thromboxane A(2) levels.  相似文献   
357.
Although studies have shown 17beta-estradiol (E2) administration following trauma-hemorrhage (T-H) attenuates alterations in T cell cytokine production, it remains unknown whether such effects of E2 are mediated via genomic or non-genomic pathways. In this study, we determined the non-genomic effects of E2 on splenic T cell cytokine production and the role of MAPK following T-H. Male Sprague-Dawley rats underwent T-H (mean BP 40 mmHg for 90 min, then resuscitation). E2, E2 conjugated with BSA (E2-BSA, 1 mg/kg E2) with or without an estrogen receptor antagonist (ICI 182 780), or vehicle was administered during resuscitation. Two hours thereafter, T cell production of IL-2 and IFN-gamma and activation of MAPK (p38, ERK-1/2 and JNK) were determined. The effect of selective MAPK inhibitors on cytokine production was also examined in vitro. IL-2 and IFN-gamma production capacity and MAPK activation decreased in T cells following T-H. However, E2 administration normalized these parameters. Although E2-BSA administration also attenuated suppression in cytokine production, the values were lower compared to sham. In contrast, E2-BSA prevented T-H-induced suppression in MAPK activation to the same extent as E2. Co-administration of ICI 182 780 abolished E2-BSA effects. These findings suggest E2 effects on T cell cytokine production following T-H are mediated at least in part via non-genomic pathway and these non-genomic effects are likely mediated via MAPK pathways.  相似文献   
358.
Although 17beta-estradiol (E2) administration following trauma-hemorrhage (T-H) reduces liver injury by decreasing neutrophil accumulation via estrogen receptor (ER)-alpha, it remains unclear whether cytokine-induced neutrophil chemoattractant (CINC)-1 production by Kupffer cells (KC) is directly modulated by ER-alpha under such condition. Male rats underwent laparotomy and hemorrhagic shock (40 mmHg for 90 min), followed by resuscitation with four times the shed blood volume in the form of Ringer's lactate. ER-alpha agonist propyl pyrazole triol (PPT; 5 microg/kg), ER-beta agonist diarylpropionitrile (DPN; 5 microg/kg), E2 (50 microg/kg), or vehicle (10% DMSO) was administered subcutaneously during resuscitation; rats were sacrificed 24h thereafter. KC were isolated and cultured with ER agonists to examine if they directly affect CINC-1 production. T-H increased plasma alanine aminotransferase (ALT; hepatic injury) and hepatic myeloperoxidase (MPO) activity. E2, PPT and DPN administration reduced increased ALT; however, PPT was more effective than DPN. PPT and E2, but not DPN significantly attenuated increased hepatic MPO activity and CINC-1 levels. PPT addition in vitro (10(-7) and 10(-6)M) significantly reduced KC CINC-1 production. In summary, the salutary effects of E2 against hepatic injury are mediated predominantly via ER-alpha which directly modulates KC CINC-1 production and hepatic neutrophil accumulation following T-H.  相似文献   
359.
Although administration of 17beta-estradiol (estrogen) following trauma-hemorrhage attenuates the elevation of cytokine production and mitogen-activated protein kinase (MAPK) activation in epidermal keratinocytes, whether the salutary effects of estrogen are mediated by estrogen receptor (ER)-alpha or ER-beta is not known. To determine which estrogen receptor is the mediator, we subjected C3H/HeN male mice to trauma-hemorrhage (2-cm midline laparotomy and bleeding of the animals to a mean blood pressure of 35 mmHg and maintaining that pressure for 90 min) followed by resuscitation with Ringer's lactate (four times the shed blood volume). At the middle of resuscitation we subcutaneously injected ER-alpha agonist propyl pyrazole triol (PPT; 5 microg/kg), ER-beta agonist diarylpropionitrile (DPN; 5 microg/kg), estrogen (50 microg/kg), or ER antagonist ICI 182,780 (150 microg/kg). Two hours after resuscitation, we isolated keratinocytes, stimulated them with lipopolysaccharide for 24 h (5 microg/mL for maximum cytokine production), and measured the production of interleukin (IL)-6, IL-10, IL-12, and TNF-alpha and the activation of MAPK. Keratinocyte cytokine production markedly increased and MAPK activation occurred following trauma-hemorrhage but were normalized by administration of estrogen, PPT, and DPN. PPT and DPN administration were equally effective in normalizing the inflammatory response of keratinocytes, indicating that both ER-alpha and ER-beta mediate the salutary effects of estrogen on keratinocytes after trauma-hemorrhage.  相似文献   
360.
Genetic Diversity of Cryptosporidium spp. in Captive Reptiles   总被引:3,自引:0,他引:3       下载免费PDF全文
The genetic diversity of Cryptosporidium in reptiles was analyzed by PCR-restriction fragment length polymorphism and sequence analysis of the small subunit rRNA gene. A total of 123 samples were analyzed, of which 48 snake samples, 24 lizard samples, and 3 tortoise samples were positive for Cryptosporidium. Nine different types of Cryptosporidium were found, including Cryptosporidium serpentis, Cryptosporidium desert monitor genotype, Cryptosporidium muris, Cryptosporidium parvum bovine and mouse genotypes, one C. serpentis-like parasite in a lizard, two new Cryptosporidium spp. in snakes, and one new Cryptosporidium sp. in tortoises. C. serpentis and the desert monitor genotype were the most common parasites and were found in both snakes and lizards, whereas the C. muris and C. parvum parasites detected were probably the result of ingestion of infected rodents. Sequence and biologic characterizations indicated that the desert monitor genotype was Cryptosporidium saurophilum. Two host-adapted C. serpentis genotypes were found in snakes and lizards.  相似文献   
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