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91.
Heparin inhibits bovine testicular hyaluronidase activity in myocardium of dogs with coronary artery occlusion 总被引:1,自引:0,他引:1
R A Wolf D Glogar L Y Chaung P E Garrett G Ertl J Tumas E Braunwald R A Kloner M L Feldstein J E Muller 《The American journal of cardiology》1984,53(7):941-944
Bovine testicular hyaluronidase (BTH) reduces experimental myocardial infarct size and ameliorates electrocardiographic signs of ischemia. This study was done to determine if heparin, an in vitro inhibitor of hyaluronidase activity, blocks the action of BTH in the myocardium of dogs after coronary artery occlusion. BTH was administered intravenously as 5,000 NF units/kg at 0.5 and 2.5 hours after coronary occlusion. Heparin was administered intravenously as a 150-unit/kg loading dose, followed by 10 units/kg per hour i.v., beginning 15 minutes before coronary occlusion. The area of myocardial ischemia at risk was assessed by a radiolabeled microsphere technique; the area that developed necrosis was assessed by a histochemical technique. In vivo activity of BTH was assessed by a colorimetric analysis of the BTH substrate, i.e., hyaluronic acid (HA), extracted from myocardial tissue. For biochemical analysis of HA, the heart was divided into anterior myocardium, which included ischemic tissue and posterior nonischemic myocardium. The myocardial HA content of dogs treated with BTH plus heparin (anterior, 3.44 +/- 0.40 micrograms HA/mg protein; posterior, 3.69 +/- 0.33 micrograms HA/mg protein) was not significantly different from control (anterior, 3.61 +/- 0.29 micrograms HA/mg protein; posterior, 3.55 +/- 0.23 micrograms HA/mg protein). In contrast, BTH lowered myocardial HA content (anterior, 2.16 +/- 0.21 micrograms HA/mg protein; posterior, 2.08 +/- 0.14 micrograms HA/mg protein) compared with either BTH plus heparin or control groups in both anterior myocardium (p = 0.006) and posterior myocardium (p = 0.001).(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
92.
In erythroid tissues the chromatin structure of the beta-globin gene locus is extensively remodeled. Changes include the formation of DNase I hypersensitive sites (HSs) over the promoters of actively expressed genes. To test the hypothesis that such "opening" of promoter chromatin structure is important for beta-globin gene expression, we placed a 101-bp erythroid-specific hypersensitive-site forming element (HSFE) from the core of LCR HS4 immediately upstream of a minimal beta-globin gene promoter. We then studied the effects of this element alone and in combination with other cis-acting elements on globin gene chromatin structure and gene expression in MEL cells and transgenic mice. Single or tandem HSFEs increased the size of the portion of the promoter accessible to DNase digestion, increased the proportion of promoters in an accessible conformation, and increased gene expression approximately 5-fold. These were equivalent to expression levels attained using a 2.8-kb microLCR construct. Inclusion of the LCR HS2 enhancer did not increase expression further. In transgenic mouse fetal liver cells the HSFE increased average expression 2.5-fold compared to the minimal promoter alone. These results indicate that a small cis-acting element is capable of remodeling local beta-globin promoter chromatin structure and producing expression similar to that seen with a microLCR construct. 相似文献
93.
A J Yates G E Gutierrez I R Garrett J J Mencel G W Nuss A B Schreiber G R Mundy 《Endocrinology》1990,126(6):2845-2849
A new analog of salmon calcitonin (N alpha-propionyl Di-Ala1,7,des-Leu19 sCT; RG-12851; here termed CTR), which lacks the ring structure of native calcitonin, was tested for biological activity in several in vitro and in vivo assay systems. The analog (CTR) and salmon calcitonin (sCT) stimulated kidney cell adenylate cyclase activity and inhibited bone resorption in organ cultures of fetal rat long bones with similar potencies and efficacies. Furthermore, CTR and sCT, at similar doses, induced comparable hypocalcemic responses in mice following sc injection or infusions. However, unlike sCT, CTR did not induce anorexia and weight loss in rats following sc injection. These data suggest that the ring structure of sCT may be important for the anorexigenic effect but is not required for effect on bone resorption or calcium homeostasis. Clinical studies appear warranted as, potentially, CTR might induce fewer side effects than does sCT. 相似文献
94.
Karl Fullam Brian Caulfield Garrett F. Coughlan Mark McGroarty Eamonn Delahunt 《Journal of Athletic Training》2015,50(9):893-904
Context
Decreased postural stability is a primary risk factor for lower limb musculoskeletal injuries. During athletic competitions, cryotherapy may be applied during short breaks in play or during half-time; however, its effects on postural stability remain unclear.Objective
To investigate the acute effects of a 15-minute ankle-joint cryotherapy application on dynamic postural stability.Design
Controlled laboratory study.Setting
University biomechanics laboratory.Patients or Other Participants
A total of 29 elite-level collegiate male field-sport athletes (age = 20.8 ± 1.12 years, height = 1.80 ± 0.06 m, mass = 81.89 ± 8.59 kg) participated.Intervention(s)
Participants were tested on the anterior (ANT), posterolateral (PL), and posteromedial (PM) reach directions of the Star Excursion Balance Test before and after a 15-minute ankle-joint cryotherapy application.Main Outcome Measure(s)
Normalized reach distances; sagittal-plane kinematics of the hip, knee, and ankle joints; and associated mean velocity of the center-of-pressure path during performance of the ANT, PL, and PM reach directions of the Star Excursion Balance Test.Results
We observed a decrease in reach-distance scores for the ANT, PL, and PM reach directions from precryotherapy to postcryotherapy (P < .05). No differences were observed in hip-, knee-, or ankle-joint sagittal-plane kinematics (P > .05). We noted a decrease in mean velocity of the center-of-pressure path from precryotherapy to postcryotherapy (P < .05) in all reach directions.Conclusions
Dynamic postural stability was adversely affected immediately after cryotherapy to the ankle joint.Key Words: postural balance, lower limb, kineticsKey Points
- A 15-minute cryotherapy application to the ankle joint decreased cutaneous temperature recorded over the anterior talofibular ligament and deltoid ligament.
- Reach distances in the anterior, posterolateral, and posteromedial directions of the Star Excursion Balance Test and center-of-pressure mean velocity decreased after cryotherapy.
- A 15-minute cryotherapy application negatively influenced dynamic postural-stability performance.
- Elite-level field-based athletes should undergo a rewarming period before returning to participation after cryotherapy to the ankle joint to ensure they are not predisposed to injury due to decreased dynamic postural stability.
95.
Dayton D. McMillan Junko Maeda Justin J. Bell Matthew D. Genet Garrett Phoonswadi Kelly A. Mann Susan L. Kraft Hisashi Kitamura Akira Fujimori Yukie Yoshii Takako Furukawa Yasuhisa Fujibayashi Takamitsu A. Kato 《Journal of radiation research》2015,56(5):784-791
Radioactive copper (II) (diacetyl-bis N4-methylthiosemicarbazone) (Cu-ATSM) isotopes were originally developed for the imaging of hypoxia in tumors. Because the decay of a 64Cu atom is emitting not only positrons but also Auger electrons, this radionuclide has great potential as a theranostic agent. However, the success of 64Cu-ATSM internal radiation therapy would depend on the contribution of Auger electrons to tumor cell killing. Therefore, we designed a cell culture system to define the contributions to cell death from Auger electrons to support or refute our hypothesis that the majority of cell death from 64Cu-ATSM is a result of high-LET Auger electrons and not positrons or other low-LET radiation. Chinese hamster ovary (CHO) wild type and DNA repair–deficient xrs5 cells were exposed to 64Cu-ATSM during hypoxic conditions. Surviving fractions were compared with those surviving gamma-radiation, low-LET hadron radiation, and high-LET heavy ion exposure. The ratio of the D10 values (doses required to achieve 10% cell survival) between CHO wild type and xrs5 cells suggested that 64Cu-ATSM toxicity is similar to that of high-LET Carbon ion radiation (70 keV/μm). γH2AX foci assays confirmed DNA double-strand breaks and cluster damage by high-LET Auger electrons from 64Cu decay, and complex types of chromosomal aberrations typical of high-LET radiation were observed after 64Cu-ATSM exposure. The majority of cell death was caused by high-LET radiation. This work provides strong evidence that 64Cu-ATSM damages DNA via high-LET Auger electrons, supporting further study and consideration of 64Cu-ATSM as a cancer treatment modality for hypoxic tumors. 相似文献
96.
97.
98.
William Dickey M.D. Ph.D. F.A.C.G. Daphne Garrett R.G.N. 《The American journal of gastroenterology》2002,97(1):79-82
OBJECTIVE: We set out to compare the success of colonoscopy using long and intermediate length standard adult instruments. METHODS: An intermediate length (133 cm working length) and long (168 cm) videocolonoscope were used on an alternate patient basis during routine endoscopy lists. Completion rates, times, and the need for external abdominal pressure were documented, as were causes of failed cecal intubation. RESULTS: Among patients with no history of colon resection and with satisfactory bowel preparation, 173 procedures were performed with the intermediate and 167 with the long colonoscope. There was no significant difference in completion rates (96% for both, excluding patients with strictures), completion times (intermediate mean = 7.73 min, long = 8.11 min; p = 0.44), or need for external abdominal pressure. Similarly, no difference was observed for male and female patients analyzed separately. Though there was no significant difference in completion rates for males and females overall (99% vs 95% excluding patients with strictures, p = 0.08), the latter had significantly longer completion times (mean = 8.75 vs 6.76 min, p < 0.001) and were more likely to require external abdominal pressure. Intermediate colonoscope length was responsible for failure to reach the cecum in one patient only (0.6%). CONCLUSIONS: Although the length of the intermediate instrument rarely compromises colonoscopy, it offers no significant advantage over the long scope for routine procedures. 相似文献
99.
Blockade of autocrine stimulation in simian sarcoma virus-transformed cells reverses down-regulation of platelet-derived growth factor receptors. 总被引:24,自引:6,他引:24
J S Garrett S R Coughlin H L Niman P M Tremble G M Giels L T Williams 《Proceedings of the National Academy of Sciences of the United States of America》1984,81(23):7466-7470
The viral (v)-sis oncogene encodes a protein (p28sis) that is structurally homologous to platelet-derived growth factor (PDGF). We have shown that simian sarcoma virus (SSV)-transformed cells containing the v-sis oncogene release a Mr 20,000 substance that is recognized by antisera to synthetic peptide sequences contained in p28sis. Medium conditioned by SSV-transformed cells competes with 125I-labeled PDGF for specific PDGF receptor sites, initiates DNA synthesis, and stimulates tyrosine phosphorylation of the PDGF receptor when added to normal cells. When normal cells are co-cultured with SSV-transformed cells, the PDGF receptors of the normal cells are down-regulated by factors released from the transformed cells. Thus, SSV-transformed cells release material that is functionally similar to PDGF. We have used anti-phosphotyrosine antibodies to purify PDGF receptors and to detect PDGF-stimulated receptors in normal cells. SSV-transformed cells have no PDGF receptors detectable by these antibodies or by 125I-labeled PDGF binding studies. However, when SSV-transformed cells are exposed to suramin, a compound that blocks binding of PDGF to its receptors, the receptors reappear on the cell surface and within 8 hr are present at the same levels as in control cells. These "new" receptor sites can be phosphorylated in response to PDGF. Thus, the absence of PDGF receptors in SSV-transformed cells is due to down-regulation of the receptors by an autocrine mechanism that can be blocked by suramin. 相似文献
100.
Van de Ven P Mao L Fogarty A Rawstorne P Crawford J Prestage G Grulich A Kaldor J Kippax S 《AIDS (London, England)》2005,19(2):179-184
OBJECTIVE: To determine whether reporting that the HIV-positive partner's viral load is undetectable rather than detectable is associated with unprotected anal intercourse (UAI) in HIV serodiscordant gay couples. METHOD: A cross-sectional study nested within two cohort studies, the Health in Men (HIM) cohort of HIV-negative men, from July 2001 to December 2003 and the Positive Health (PH) cohort of HIV-positive men, from February 2002 to August 2003. The study participants were 119 men in an HIV serodiscordant regular relationship of at least 6 months duration (45 HIV-negative men from HIM, 74 HIV-positive men from PH). The main outcome measure was the occurrence of UAI within the relationship in the previous 6 months. RESULTS: Eighty-two men reported no UAI and 37 reported some UAI. Of couples in which the HIV-positive partner's viral load was reported to be undetectable, 39.4% reported UAI compared with 20.8% of those where viral load was reported to be detectable (P = 0.04). In multivariate analysis, significant predictors of UAI were younger age [odds ratio (OR), 0.94; 95% confidence interval (CI), 0.87-1.00; P = 0.05], greater HIV optimism (OR, 4.98; 95% CI, 1.25-19.8; P = 0.02) and reported undetectable viral load (OR, 2.88; 95% CI, 1.13-7.37; P = 0.03). CONCLUSIONS: Most serodiscordant gay couples do not engage in any UAI. UAI within such relationships is significantly more likely to occur where the HIV-positive partner is reported to have undetectable viral load. UAI in HIV serodiscordant relationships is problematic even if viral load is undetectable because of unknown risk parameters, viral load variability and the possibility of drug-resistant strains of HIV. 相似文献