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101.
Protein kinase C (PKC) acutely increases calcium currents in Aplysia bag cell neurons by recruiting calcium channels different from those constitutively active in the plasma membrane. To study the mechanism of PKC regulation we previously identified two calcium channel alpha1-subunits expressed in bag cell neurons. One of these, BC-alpha1A, is localized to vesicles concentrated primarily in somata and growth cones. We used antibodies to BC-alpha1A to analyze its expression in the bag cell neurons of juvenile Aplysia at a developmental stage at which PKC-sensitive calcium currents have previously been shown to be low. We find that vesicular BC-alpha1A staining is generally reduced in juvenile bag cell neurons but that its expression level can vary among juvenile animals. In 17 bag cell clusters examined, the percentage of neurons that displayed punctate alphaBC-alpha1A staining ranged from 0 to 85%. Sampling of calcium currents from cells of the same clusters by whole cell patch-clamp techniques revealed that the PKC-sensitive calcium current density is significantly correlated with the degree of vesicular staining. In contrast, no correlation of basal calcium current levels with aBC-alpha1A staining was found. These results strongly suggest that BC-alpha1A, a member of the ABE-subfamily of calcium channels, carries the PKC-sensitive calcium current in bag cell neurons. They are consistent with a model in which PKC recruits channels from the vesicular pool to the plasma membrane. 相似文献
102.
TA Swartz R Handsher Y Manor P Stoeckel A Barkay E Mendelson A Leventhal 《Canadian Metallurgical Quarterly》1998,16(20):2090-2095
A combined enhanced inactivated polio vaccine (EIPV) and oral polio vaccine (OPV) programme was introduced in Israel in 1990, with the purpose of providing a solution to the persistent polio morbidity in spite of a 30 year long OPV programme. The schedule comprised two doses of EIPV administered at the age of 2 and 4 months, intercalated with two doses of OPV at 4 and 6 months, followed by a reinforcing dose with the two vaccines simultaneously administered at 12 months. The 5-year evaluation of the programme included: the assessment of clinical suspicions of polio, early immune response in successive cohorts administered the new schedule, dynamics of the immune profile in a cohort followed up to the age of 5, and monitoring of wild poliovirus excretion in sewage specimens collected in 25 permanent sites throughout Israel as well as from the Palestinian Authority. No paralytic polio cases associated with a wild or vaccinal poliovirus strain were detected since the introduction of the programme. At the age of 4 months, one week after administration of the second EIPV and first OPV dose, 100% seropositivity and high geometric mean titres (GMTs) of neutralizing antibody (NA) to the three vaccinal and to the wild poliovirus type 1, responsible for the 1988 polio outbreak, were observed. No change in percent of seropositivity occurred between the age of 6 and 12 months. Thirty days after the IPV and OPV reinforcing doses, GMTs to each of the four poliovirus strains were > or = 3037. Up to the age of 5, the seropositivity was unchanged. After a 2.5-10-fold decline in the first year following the completion of the programme, GMTs to the three vaccinal and the wild poliovirus strain levelled off at rather high values, considered protective. Between 1990 and 1995, 16 wild poliovirus type 1 strains were isolated in three separate episodes in Gaza Strip sewage and once only in one Israeli site very close to Gaza City. The rapidly established, high and persistent NA titre to the vaccinal and wild poliovirus strains and the presence of immunological memory are indicative of high individual protection throughout the first 5 years of life. The only one-time introduction, without circulation, of a wild poliovirus strain in a single Israeli settlement suggests community protection. The intercalated programme offers a contribution to polio eradication by providing a solution to the primary and secondary failure associated with OPV, as well as to the control of vaccine-associated paralytic poliomyelitis. 相似文献
103.
SE Santos AK Ribeiro-Dos-Santos JF Guerreiro EJ Santos TA Weimer SM Callegari-Jacques MA Mestriner MH Franco MH Hutz FM Salzano 《Canadian Metallurgical Quarterly》1998,25(6):505-522
A total of 732 individuals affiliated with six Amazonian Indian populations were variously studied in relation to 26 protein genetic systems. Eleven of them were found to be monomorphic in these groups, in accordance with previous investigations. Similarities and dissimilarities (the latter involving the Rh, Duffy, haptoglobin and transferrin systems) were observed in relation to earlier investigations in four of these populations (Galibi, Palikour, Mundurucu and Tenharim). A dimeric, cathodal variant of albumin was found among two Galibi subjects, and the fairly common occurrence of CP* ACAY among some South American Indian populations was confirmed. The results in the six populations were compared with those from 29 others. When relationships are searched for among tribes of the same linguistic group, the factor that seems to be most influential is geographical localization, an exception being the pattern observed among the Cayapo subgroups. The latter shows genetic differences of the same level of magnitude as those observed among Ge-speaking tribes. 相似文献
104.
DB Fram TA Aretz JF Mikan A Raisner JF Mitchel LD Gillam DD Waters RG McKay 《Canadian Metallurgical Quarterly》1993,126(4):969-978
The purpose of this study was to assess the safety and histologic effects of radiofrequency thermal balloon angioplasty in the coronary vasculature of normal pigs. Radiofrequency thermal balloon angioplasty was performed in 30 coronary arteries of 16 nonatherosclerotic pigs. Heated inflations were performed at either 50 degrees, 60 degrees, or 70 degrees C for 30 or 60 seconds, and were compared with five nonheated inflations in five additional arteries. All balloon inflations were performed at 2 atm pressure with a balloon/vessel diameter ratio of 1.2 to 1. Heart rate, arterial pressure, and left ventricular pressure were monitored continuously for each animal. A 12-lead ECG, coronary angiography, and two-dimensional transthoracic echocardiography were performed before and 1 hour after each balloon inflation. Each animal was subsequently put to death for postmortem cardiac examination. Heated inflations were well tolerated in 28 of the 30 arteries without significant adverse effects. During one inflation, ventricular fibrillation occurred because of prolonged ischemia from an occlusive guiding catheter. In another artery, a heated inflation resulted in a dissection with a transient decrease in distal coronary flow. Histologic examination revealed a significant increase in wall thinning and elastic fiber straightening with heating at 70 degrees C for both 30 and 60 seconds, and a significant increase in intracoronary thrombus with heating at 70 degrees C for 60 seconds. Depth of periarterial myocardial heat necrosis paralleled the increase in temperature, with an average depth of 166 microns at 50 degrees C, 312 microns at 60 degrees C, and 1031 microns at 70 degrees C. In vivo, radiofrequency coronary angioplasty can be performed relatively safely without significant electrical, hemodynamic, or ischemic changes beyond those seen with conventional nonthermal angioplasty. The extent of heat-induced vessel wall thinning, elastic tissue straightening, intracoronary thrombus formation, and periarterial myocardial necrosis are all related to balloon temperature or duration of heating. 相似文献
105.
JM Hodgson IB Puddey LJ Beilin TA Mori KD Croft 《Canadian Metallurgical Quarterly》1998,128(4):728-732
Isoflavonoids are a class of flavonoids that are derived in the human diet mainly from soybean-based foods. The major dietary isoflavonoids, genistein and daidzein, have estrogen-like activity and are classed as phytoestrogens. Because estrogens can lower serum LDL cholesterol and raise HDL cholesterol, the objective of this study was to determine if isoflavonoids could improve serum lipids in healthy subjects. Forty-six men and 13 postmenopausal women not receiving hormone replacement therapy completed a randomized, double-blind, placebo-controlled trial of two-way parallel design and 8 wk duration. One tablet containing 55 mg of isoflavonoids (predominantly in the form of genistein) or one placebo tablet was taken daily with the evening meal. Subjects maintained their usual diet and physical activity, which were unchanged throughout the intervention. Measurement of isoflavonoids and their metabolites in 24-h urine samples provided an assessment of compliance and of isoflavonoid metabolism. Serum total, LDL, HDL and HDL subclass cholesterol, triglycerides and lipoprotein (a) were assessed at baseline and during the last week of intervention. After adjustment for baseline values, no significant differences in postintervention serum lipid and lipoprotein (a) concentrations between groups were identified. Further adjustment for age, gender and weight change did not alter the results. In addition, changes in urinary isoflavonoids were not significantly correlated with changes in serum lipids and lipoprotein (a). Therefore, this study does not support the hypothesis that isoflavonoid phytoestrogens can improve the serum lipids, at least in subjects with average serum cholesterol concentrations. 相似文献
106.
For ultrasonographic B-scan images collected by means of a handheld transducer moving in the elevational direction, frame spacings are computed with a speckle-decorrelation algorithm, without additional positioning hardware. Fully developed speckle volumes are automatically segmented and spacing computed from the decorrelation curves. Position accuracy is within 10% for phantoms and 15% for breast studies. The algorithm provides image-based registration, which allows accurate three-dimensional volume rendering. 相似文献
107.
Glycosyltransferases in the Golgi apparatus synthesize cell wall polysaccharides and elaborate the complex glycans of glycoproteins. To investigate the targeting of this type of enzyme to plant Golgi compartments, we generated transgenic Arabidopsis plants expressing alpha-2,6-sialyltransferase, a glycosyltransferase of the mammalian trans-Golgi cisternae and the trans-Golgi network. Biochemical analysis as well as immunolight and immunoelectron microscopy of these plants indicate that the protein is targeted specifically to the Golgi apparatus. Moreover, the protein is predominantly localized to the cisternae and membranes of the trans side of the organelle. When supplied with the appropriate substrates, the enzyme has significant alpha-2,6-sialyltransferase activity. These results indicate a conservation of glycosyltransferase targeting mechanisms between plant and mammalian cells and also demonstrate that glycosyltransferases can be subcompartmentalized to specific cisternae of the plant Golgi apparatus. 相似文献
108.
Differences in duration judgments made by younger and older adults were reviewed. Previous research is unclear about whether such differences exist and, if so, how they may be explained. The meta-analyses revealed substantial age-related differences. Older adults gave larger verbal estimates and made shorter productions of duration than did younger adults. There were no age-related differences in reproduction of duration or in psychophysical slope relating judged and target duration. Older adults' duration estimates were more variable than were those of younger ones. Findings are discussed in terms of pacemaker rate and attentional resources. An explanation regarding divided attention between nontemporal and temporal information processing best explains the findings. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
109.
PW Pisters JL Abbruzzese NA Janjan KR Cleary C Charnsangavej MS Goswitz TA Rich I Raijman RA Wolff R Lenzi JE Lee DB Evans 《Canadian Metallurgical Quarterly》1998,16(12):3843-3850
PURPOSE: To evaluate the toxicities, radiographic and pathologic responses, and event-free outcomes with combined modality treatment that involves preoperative rapid-fractionation chemoradiation, pancreaticoduodenectomy, and electron-beam intraoperative radiation therapy (EB-IORT) for patients with resectable pancreatic adenocarcinoma. PATIENTS AND METHODS: Patients with radiographically resectable localized adenocarcinoma of the pancreatic head were entered onto a preoperative protocol that consisted of a 2-week course of fluorouracil (5-FU) 300 mg/m2 daily 5 days per week and concomitant rapid-fractionation radiation 30 Gy, 3 Gy daily 5 days per week. Radiographic restaging was performed 4 weeks after chemoradiation, and patients with localized disease underwent pancreaticoduodenectomy with EB-IORT 10 to 15 Gy. RESULTS: Thirty-five patients were entered onto the study and completed chemoradiation, 34 (97%) as outpatients. Three patients (9%) experienced grade 3 nausea and vomiting; no other grade 3 or 4 toxicities were observed. Of the 27 patients taken to surgery, 20 patients (74%) underwent pancreaticoduodenectomy with EB-IORT. All patients had a less than grade III pathologic response to preoperative chemoradiation. At a median follow-up of 37 months, the 3-year survival rate in patients who underwent combined modality therapy was 23%. CONCLUSION: Combined modality treatment with preoperative rapid-fractionation chemoradiation, pancreaticoduodenectomy, and EB-IORT is associated with minimal toxicity and excellent locoregional control. This represents one approach to maximize the proportion of patients who receive all components of combined modality therapy and avoids the toxicity of pancreaticoduodenectomy in patients found to have metastatic disease at the time of restaging. 相似文献
110.
TA Wiegers J Van der Zee JJ Kerssens MJ Keirse 《Canadian Metallurgical Quarterly》1998,46(11):1505-1511
In The Netherlands women with low risk pregnancies can choose whether they want to give birth at home or in hospital, under the care of their own primary caregiver. The majority of these women prefer to give birth at home, but over the last few decades an increasing number of low risk women have chosen a hospital birth, leaving hospital with their baby shortly after delivery. As both this trend and its effects have not been extensively investigated, a study was designed to examine the determinants of the choice for home or hospital birth. It was hypothesized that the choice would be determined by a combination of personal and social factors. Structural equation modelling indicated that social factors, especially the confidence of significant others in home birth and the expectations of hospital care during childbirth, were by far the strongest predictors of choice. Personal factors, measured as perceived health status before and during pregnancy, the existence of minor symptoms and fear of pain or complications during birth, were found to play an indirect role. Demographic variables such as age, education and urbanization showed no effect. These findings indicate that emphasizing the good results and excellent quality of Dutch maternity care at home is likely to support and strengthen the general acceptance of home birth. 相似文献