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1.
Pretreatment of rats with isoprenaline sulphate (IPR) stimulated DNA synthesis in both salivary and mammary gland tissues. Salivary gland tumours induced by N-methyl-N-nitrosourea (MNU) were observed for the first time in rats, but occurred only in IPR-pretreated animals given MNU during the period of IPR-stimulated DNA synthesis. The cumulative index of MNU-induced mammary tumours and the number of tumours per tumour-bearing rat were increased by IPR-pretreament only if the animals received MNU during the period of IPR-stimulated DNA synthesis.  相似文献   

2.
The gated semiautomated first pass and non-gated manual first pass methods of right ventricular ejection fraction calculation were compared. It was found that the gated first pass study was the simplest and fastest to process and was overall judged to give at least as much information as the other technique.  相似文献   

3.
OBJECTIVE: To determine the relationship between the presence of Ureaplasma urealyticum in the amniotic cavity and adverse maternal and perinatal outcome in women with preterm labor. METHODS: Amniocentesis was performed in 181 patients with preterm labor and intact membranes. Amniotic fluid (AF) was cultured for aerobic and anaerobic bacteria and mycoplasmas. Patients were divided into three groups according to the results of AF culture: those with negative AF cultures (n=160), those with positive AF cultures and in whom the only microbial isolate was U urealyticum (n=11), and those with positive cultures for non-ureaplasmas or mixed microorganisms (n=10). Survival techniques were used for analysis. RESULTS: The prevalence of positive AF cultures in which the only microbial isolate was Uurealyticum was 6.1% (11 of 181), and of positive cultures with non-ureaplasmas or mixed microorganisms was 5.5% (10 of 181). The amniocentesis-to-delivery interval was significantly shorter in patients with positive cultures limited to U urealyticum than in those with negative cultures (median 7 [range 0.1-149] hours versus median 264 [0.1-2659] hours, P < .001). Preterm delivery within 48 hours, 72 hours, and 7 days was more frequent in patients with U urealyticum in the AF than in those with sterile AF (48 hour: 91% versus 33%; 72 hour: 91% versus 36%; 7 days: 100% versus 45%, P < .001 for each). Patients with positive AF cultures limited to U urealyticum had a significantly higher rate of adverse perinatal outcome than those with negative culture. Adverse outcomes included low gestational age at birth, low birth weight, histologic chorioamnionitis, significant neonatal morbidity, and perinatal death. CONCLUSION: Microbial invasion of the amniotic cavity with U urealyticum is a risk factor for impending preterm delivery and adverse perinatal outcome.  相似文献   

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5.
Platelet-activating factor (PAF), a phospholipid mediator exhibiting potent biological activities, has been shown to stimulate amylase release from the pancreas and salivary glands. The capacity of salivary glands for PAF biosynthesis in response to stimulation has also been demonstrated. To elucidate the role of PAF in salivary glands, we studied the regulation of platelet-activating factor synthesis by the autonomic nervous system in canine salivary glands. Acetylcholine and ionomycin stimulated PAF production in dispersed cells from parotid, submandibular, and sublingual glands of dogs. Norepinephrine and phenylephrine, but not isoproterenol, also stimulated PAF production in submandibular gland cells. Norepinephrine-induced PAF production was blocked by phentolamine but not by propranolol. Acetylcholine and norepinephrine increased both the PAF production and liberation of [14C]arachidonic acid from cells pre-labeled with [14C]arachidonic acid in the presence of Ca2+ in the medium. These stimulants increased [14C]arachidonic acid liberation without the accompanying production of PAF in Ca(2+)-deprived medium. No activators or inhibitors of protein kinase C produced or affected acetylcholine-induced PAF production. Lyso-PAF:acetyl-CoA acetyltransferase was activated in the cells treated with acetylcholine, norepinephrine, isoproterenol, and 8Br-cyclic AMP. Deprivation of Ca2+ in the medium markedly reduced acetylcholine-induced activation of the transferase, but little affected norepinephrine-, isoproterenol-, and 8Br-cyclic AMP-induced activation. Dithiothreitol-insensitive cholinephosphotransferase activity was also increased by acetylcholine, norepinephrine, isoproterenol, and 8Br-cyclic AMP, and the deprivation of Ca2+ in the medium further increased the activation of the enzyme activity by these agents. These results suggest that PAF synthesis in canine salivary glands is under the control of muscarinic cholinergic and alpha-adrenergic systems via Ca(2+)-dependent remodeling pathways, and that the independent activation of either phospholipase A2 or acetyltransferase is insufficient for PAF production in submandibular gland cells, i.e., the concurrent activation of these enzymes is required.  相似文献   

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7.
目的:探讨涎腺嗜酸细胞肿瘤的临床病理特征、鉴别诊断、治疗和预后.方法:对23例嗜酸细胞腺瘤、15例嗜酸细胞腺癌的临床特点、病理表现及组织化学、免疫组织化学和电子显微镜观察结果进行观察、分析,同时对所有病例进行随访,分析患者的治疗和预后.结果:嗜酸细胞腺瘤多发生于腮腺(95.6%),23例患者经局部切除后均无复发,诊断主要依赖组织病理学检查,即肿瘤由嗜酸细胞构成,包膜完整.嗜酸细胞腺癌亦为腮腺多发,是一种恶性程度较高的涎腺肿瘤,局部复发(50%)、区域淋巴结转移(50%)和远处转移率(28.6%)都较高,根治性手术是首选治疗方案,该肿瘤的诊断除依据常规病理特点外,组织化学、免疫组织化学和电子显微镜观察均可证明嗜酸细胞胞浆颗粒为大量线粒体,可辅助诊断,其中免疫组织化学方法因特异性强、简单易行更加适用.结论:涎腺嗜酸细胞肿瘤较少见,嗜酸细胞腺瘤预后较好,肿瘤切除后很少复发;嗜酸细胞腺癌预后差,根治性手术是首选治疗方案,肿瘤诊断主要依靠组织病理学检查,线粒体免疫组织化学有助于诊断和鉴别诊断.  相似文献   

8.
Although DNA is the critical target for the lethal effects of irradiation, the precise mechanisms by which irradiation causes damage in tissues and biological systems is not fully understood. In the present study, the number of mast cells and the expression of the neuropeptide substance P (SP) in salivary glands were examined 10 days after a regimen of irradiation. The irradiation was given as a single dose or 5 consecutive days with daily doses of 7 Gy up to a total dose of 35 Gy. In addition, the number of mast cells and the expression of SP were examined 2 and 24 h after a single dose of 7 Gy. Immunohistochemical staining for 5-hydroxytryptamine (5-HT) and staining with avidin peroxidase and toluidine blue were used to detect mast cells. At examination 2 and 24 h after irradiation treatment, no change in the number of mast cells and the pattern of SP expression was observed. Ten days after irradiation there was a remarkable reduction in the number of mast cells in all the three glands, but there was a marked increase in the number of nerve fibers showing SP-like immunoreactivity in the parenchyme. The results show that early time-dependent alterations in the density of mast cells occur in response to irradiation, and that these changes occur concomitantly with changes in the expression of SP. Since the peripheral nervous system is a main regulator of salivary gland function, it is tempting to speculate that the nervous system interacts with mast cells via SP in modulating irradiation provoked tissue responses in salivary glands.  相似文献   

9.
实验考察了粗金中含有的10种杂质元素对火试金重量法测定银量的影响。结果表明:试料中的铜、铁、镍、锌、铂、钯、硒、碲、锑、铋质量分数分别不高于20%、10%、5%、5%、0. 2%、0. 5%、5%、2%、2%、2%时,该方法测定结果的准确度和精密度符合要求;杂质元素含量超过上限量值时,可通过减少称样量及增加铅箔用量等措施提高方法的适用性。该研究为黄金冶炼企业粗金产品的质量控制、贸易计价等提供技术参考。  相似文献   

10.
重量法测定电镀锌板和热镀锌板镀锌质量的比较   总被引:1,自引:0,他引:1       下载免费PDF全文
根据GB/T1839-2008采用的重量法分别测定了电镀锌板单面镀锌质量和热镀锌板单面镀锌质量;利用辉光放电发射光谱法测定电镀锌板和热镀锌板的镀锌质量,并表征了溶解前后电镀锌板和热镀锌板的镀层结构。结果发现:热镀锌板和电镀锌板镀层结构略有不同,但重量法能有效溶解镀锌板的镀层,使纯镀锌层、锌铁交界层及渗入钢基中的锌全都溶解下来。此外,试验还发现重量法和辉光放电发射光谱法测定电镀锌板和热镀锌板镀锌质量的分析结果有较好的一致性,这也进一步证明重量法是测定不同类型镀锌板的镀锌质量的较准确方法。另外,根据辉光放电发射光谱法测定不同镀锌板镀层结构的分析结果及电感耦合等离子体原子发射光谱法(ICP-AES)测定镀层中铁和铝含量的分析结果,讨论了重量法测定电镀锌板及热镀锌板镀锌质量误差的来源和大小。发现引起重量法测定不同镀锌板的误差主要由镀层中除锌元素以外的铁和铝元素的溶解引起的。而重量法测定电镀锌板镀锌质量的误差要远远小于重量法测定热镀锌板镀锌质量误差,这说明重量法更适合电镀锌板镀锌质量的测定。  相似文献   

11.
In 148 patients after major surgical procedures urinary endotoxin levels were determined and compared with bacteriological results. The study was designed as a screening study. Urine samples were collected once by suprapubic or transurethral catheters. In a first series of 49 patients urine bacteriology was positive (mainly, Gram-negative rods were found) in 3 cases. However, endotoxin determination was positive in these 3 patients and in a further 10 patients receiving antibiotic therapy for other reasons. Therefore, the following 99 patients were studied also by urinalysis by reagent strips for leukocytes and nitrite. In the second series, 12 urine cultures positive for bacteria were observed. Eleven samples were also endotoxin positive. Five more patients were endotoxin positive and had pathological but unspecific reagent strip results. These patients were treated with antibiotics for other reasons. Patients with candida found in the urine culture (n = 5) were endotoxin negative. Thus, endotoxin determination in urine obtained by suprapubic or transurethral catheters proved to be a very sensitive method for diagnosis of bacterial contamination, even during antibiotic treatment.  相似文献   

12.
A method for the isolation of polytene nuclei from salivary glands cells of the Diptera Rhynchosciara americana is described. The stage-specific morphological pattern of the chromosome is maintained during the isolation. The isolated nuclei show two distinct RNA polymerase activities, namely I and II, characterized on the basis of ionic requirements and alpha-amanitin sensitivity. Studies of the product under the incubation conditions show that the system allows the synthesis of high-molecular weight RNA, beside a low molecular weight peak which may comprise pre-4S and 5S RNAs. Autoradiographic studies carried out in the presence or absence of the toxin alpha-amanitin showed that micronucleoli contain products of RNA polymerase type I activity (ribosomal RNA) and that the DNA puffs are engaged in alpha-amanitin sensitive RNA synthesis and thus are sites of polymerase type II activity.  相似文献   

13.
1. We examined the sialogogic activities in rat major salivary glands of SNI-2011, in comparison with those of pilocarpine and McN-A-343, and we characterized the subtypes of muscarine receptors that are involved in the sialogogic responses to SNI-2011 and McN-A-343. 2. SNI-2011 at doses ranging from 1 to 10 mg/kg (i.v.) increased the secretion of saliva in a dose-dependent manner. The dose-response curves for SNI-2011 were approximately parallel to curves for pilocarpine but the potency of SNI-2011 was about 25-fold lower than that of pilocarpine. 3. The total volume of saliva secreted in response to McN-A-343 was very much less than that secreted in response to SNI-2011. 4. The salivation induced by SNI-2011 and by McN-A-343 was inhibited by various antagonists with the following rank order of potency: 4-DAMP > pirenzepine > AF-DX 116. 5. Our results suggest that the sialogogic effects of SNI-2011 and McN-A-343 are mediated by direct stimulation of M3 receptors in salivary glands and that SNI-2011 may prove useful in the management of xerostomia in patients with Sj?gren's syndrome.  相似文献   

14.
We studied the effects of the new antioxidant drug U-83836E during splanchnic artery occlusion (SAO) shock in the rat. Serum tumor necrosis factor (TNF-alpha), white blood cell (WBC) count, mean arterial blood pressure (MAP), survival rate and the responsiveness to acetylcholine of aortic rings were investigated. SAO shock produced a marked increase in serum TNF-alpha (241.4 +/- 18.2 U/ml vs Not Detectable in basal), reduced MAP (51.4 +/- 4 mmHg vs 85.1 +/- 5 mmHg), survival time (80 +/- 10 min vs > 240 min), WBC count (2.8 +/- 0.4 x 10(3)/mm3 cells vs 11.7 +/- 0.9 x 10(3)/mm3 cells) and blunted the responsiveness to ACh of aortic rings (60 +/- 3% tension vs 23 +/- 4% tension). The analogue of vitamin E, U-84836E, administered at onset of reperfusion, lowered serum TNF-alpha (38.4 +/- 6.5 U/ml; p < 0.001), improved MAP (67.5 +/- 3.8 mmHg; p < 0.001), WBC count (8.9 +/- 0.6 x 10(3)/mm3; p < 0.001), and survival time (235 +/- 15 min; p < 0.001), and restored the responsiveness to ACh of aortic rings (32 +/- 3.7% tension; p < 0.001). These preliminary data suggest that this new compound could be a promising drug in shock therapy.  相似文献   

15.
Adhesion of Listeria monocytogenes to intestinal endothelial cells is an important initial event in the pathogenesis of infection which is not well understood. The suggestion has been made that some proteins, including internalin and actin polymerisation protein (ActA), and carbohydrate molecules mediate, at least in part, the adhesion of listeria to certain cultured mammalian cells. This study investigated the role of a L. monocytogenes cell-surface protein of 104 kDa (p104) in adhesion to human intestinal enterocyte-like Caco-2 cell lines by transposon (Tn916) mutagenesis and a p104-specific monoclonal antibody (MAb-H7). Genotypic and phenotypic characteristics of Tn916-transformed L. monocytogenes strains, AAMU530 and AAMU572, revealed that these strains did not express p104, and the transposon had been inserted at a single locus in the structural gene. Strains AAMU530 and AAMU572 yielded only 10 and 6.3% adhesion to Caco-2 cells. Coating of L. monocytogenes and L. innocua wild-type strains with MAb-H7 reduced adhesion to Caco-2 cells from 100% to 50 and 45%, respectively, whereas on isotype control MAb EM-7G1 had no effect. Western blot analysis with MAb-H7 indicated that p104 is present in all Listeria spp. except in L. grayi. Furthermore, p104 is also present in internalin (BUG8) and ActA (LUT12) deficient strains, suggesting that p104 is indeed different from internalin or ActA proteins. Cytotoxicity analysis of strains AAMU530 and AAMU572 demonstrated that these strains, although haemolytic and phospholipase-positive, were avirulent when tested with a hybridoma B-lymphocyte cell line. Loss of virulence could be attributed to the interruption of adhesion of mutant strains to the hybridoma cell line. These results strongly suggest that p104 is an adhesion factor in L. monocytogenes and possibly in other Listeria species and is involved in adhesion to intestinal cells.  相似文献   

16.
BACKGROUND: The authors had previously conducted an investigation of minor salivary gland mucoepidermoid carcinoma, in which they demonstrated that certain clinical and histopathologic features were useful in predicting biologic outcome. The current study investigated the usefulness of these features in determining the prognoses of patients with mucoepidermoid carcinomas of the major salivary glands. METHODS: Clinical data and 15 histopathologic features were compared in 4 patient groups based on outcome after initial treatment. The outcome groups were 1) survival without disease, 2) survival with tumor recurrence only, 3) survival with metastasis, and 4) death related to tumor. A numeric score was assigned to each unfavorable histopathologic feature. Low grade tumors had scores of 0-4. Intermediate grade tumors scored 5 or 6. High grade tumors had scores higher than 6. RESULTS: Most patients (75%) were tumor free after the initial treatment. Twenty-one patients (9%) had local recurrence only, 12 (5%) demonstrated metastasis and survived, and 25 patients (11%) died of their disease. CONCLUSIONS: Clinical features associated with metastasis or death were more advanced age, tumor size, and preoperative symptoms. Histopathologic features that correlated with poor outcome were cystic component less than 20%, 4 or more mitotic figures per 10 high-power fields, neural involvement, necrosis, and anaplasia. All five of these histopathologic features demonstrated statistical prognostic significance when parotid gland tumors from Groups 1 and 4 were compared (P < 0.001). The point-based grading system demonstrated a statistically significant correlation with outcome for parotid tumors but not for submandibular tumors. The authors' findings indicate that patients with tumors of equal histopathologic grade have a better prognosis when their tumors are in the parotid gland than when their tumors are in the submandibular gland. Six of eight submandibular tumors that metastasized or resulted in death were low grade lesions, and none were high grade.  相似文献   

17.
采用热重分析法研究了铁含量对焦炭反应的影响规律.利用液相吸附法制备了不同Fe2O3含量的焦炭样品,通过对样品的微观分析和焦炭反应动力学的研究,阐释了铁元素对反应机理的影响.结果表明,铁对焦炭溶损反应具有正催化作用,且催化作用随铁含量的增大而加强;铁的存在降低了焦炭反应的起始反应温度和剧烈反应温度,导致焦炭过早破碎,影响焦炭强度;同时铁的存在也降低了焦炭溶损反应的反应级数和活化能.反应级数从无Fe2O3添加时的1.53级降为零级.研究表明,Fe2O3均匀分布在焦炭表面使其能提供更多的有效催化活性中心,进而对溶损反应起到催化作用.  相似文献   

18.
The choline acetyltranferase activity underwent marked changes during the life span: in the submaxillaries, the total enzyme activity increased 70-fold from birth up to the age of 3 months and it then remained constant throughout the rest of the observation period, i.e. up to 28-29 months; in the parotids, in contrast, it continued to rise beyond the age of 3 months and the highest value was reached at 24 months. The weights of the glands increased markedly up to 3 months. The gain in weight was less pronounced thereafter.  相似文献   

19.
Two triangulation methods for measuring perceived egocentric distance were examined. In the triangulation-by-pointing procedure, the observer views a target at some distance and, with eyes closed, attempts to point continuously at the target while traversing a path that passes by it. In the triangulation-by-walking procedure, the observer views a target and, with eyes closed, traverses a path that is oblique to the target; on command from the experimenter, the observer turns and walks toward the target. Two experiments using pointing and 3 using walking showed that perceived distance, averaged over observers, was accurate out to 15 m under full cue conditions. For target distances between 15 and 25 m, the evidence indicates slight perceptual underestimation. Results also show that observers, on average, were accurate in imaginally updating the locations of previously viewed targets. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

20.
In order to evaluate the direct effect of isoflurane-nitrous oxide and halothane-nitrous oxide anaesthesia on cardiac contractility in 20 adults, we have used a method based on left ventricular end-systolic wall stress (LVESWS) vs velocity of circumferential fibre shortening with corrected heart rate (Vcfc), obtained by transoesophageal echocardiography. We found that LVESWS (index of afterload) decreased significantly with isoflurane-nitrous oxide (n = 10) in concentrations of 1.5-1.95 MAC, but there were no significant changes in LVESWS with halothane-nitrous oxide (n = 10). Vcfc decreased significantly with halothane-nitrous oxide in concentrations of 1.5-1.95 MAC, but this index did not change significantly with isoflurane-nitrous oxide. However, there was no significant difference between the two groups in LVESWS or Vcfc. In the analysis of the LVESWS-Vcfc relationship, myocardial contractility associated with isoflurane-nitrous oxide anaesthesia did not differ significantly from that associated with halothane-nitrous oxide anaesthesia at equiMAC concentrations. The results suggest that halothane-nitrous oxide anaesthesia, at 1.5-1.95 MAC, maintained myocardial contractility in similar anaesthetic concentrations to isoflurane-nitrous oxide.  相似文献   

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