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1.
A systematic approach to reconstruction of neglected tears of the patellar tendon. A case report 总被引:1,自引:0,他引:1
Neglected tears of the patellar tendon due to loss of active extension remain a difficult therapeutic endeavor. The goals in the approach to this diagnosis include restoration of both structural and functional integrity of the extensor mechanism. A procedure has been developed utilizing Z-shortening of the patellar tendon, Z-lengthening of the quadriceps tendon, and the semitendinosis gracilis as a biologic splint. This technique allows establishment of preoperative goals, including restoration of the muscle-tendon complex in its anatomic position, restoration of quadriceps function, preservation of vascularity of the reconstructed tendon, and splinting of the patellar tendon. This reconstruction allows early mobilization and rehabilitation. 相似文献
2.
顺铂聚乳酸微球的药物释放特性及肝动脉栓塞研究 总被引:5,自引:0,他引:5
对顺铂聚乳酸微球进行了体外药物释放和家犬肝动脉栓塞研究。该微球粒径范围为50~200μm,平均粒径为115.76±35.94μm,顺铂含量为37.16%(W/W);体外药物释放机制符合Higuchi方程;肝动脉栓塞后8h,肝组织顺铂浓度高达21.55±12.18μg/g,明显高于肝动脉灌注顺铂组:3.16±0.09μg/g(P<0.05);肝动脉栓塞组的顺铂血浓峰值、各取血点浓度及曲线下面积AUC皆低于肝动脉灌注顺铂组。可望达到提高栓塞部位的药物疗效,降低全身毒副反应的作用。 相似文献
3.
4.
Islet cell carcinomas of the pancreas: a twenty-year experience 总被引:16,自引:0,他引:16
Unlike its lethal exocrine counterpart, islet cell carcinoma of the pancreas is an indolent neuroendocrine neoplasm. The majority of these tumors are hormonally active. When functioning, a number of clinical syndromes (for example, hyperinsulinism, Zollinger-Ellison and Cushing's syndromes) may be evident. Fifty-eight patients surgically treated between 1965 and 1984 were retrospectively analyzed. The purpose of this study was to determine the distribution of functioning versus nonfunctioning tumors and the response to type of therapy. Mean postoperative follow-up was 7.4 years. Survival and prognostic indices were calculated by the Kaplan-Meier method and compared with log-rank tests. Of the group, 54% had functioning and 46% nonfunctioning tumors. Gastrinomas were the most common functioning tumors encountered (19%). Of interest was the finding that nonfunctioning tumors increased steadily during the last 15 years of the study (25% to 65%). Curative resections were performed in 15 (26%) and noncurative procedures in 43 patients (74%), with an overall operative mortality rate of 3%. Symptomatic improvement was achieved in 90% (curative) and 51% (noncurative). Survival at 3 years was 87% and 66% for the curative and noncurative groups, respectively (p less than 0.1), with an overall 5-year survival of 42%. The absence of hepatic metastases was a major predictor of survival at 3 years (82% vs 56%, p less than 0.05). Survival was statistically better at 3 years in those patients with gastrinomas compared with patients with nonfunctioning tumors (91% vs 58%, p less than 0.05). Although surgical cure is rare, significant long-term palliation may be achieved in a large percentage of patients with an aggressive surgical approach, occasional total gastrectomy, combination chemotherapy, H2 blockade, when indicated, and, most recently, with the new long-acting analogue of somatostatin. 相似文献
5.
The buffering capacity of tears collected from contact lens wearers was compared to that from non-contact lens wearers. Three groups of subjects were investigated: 6 subjects not wearing contact lenses, 3 subjects wearing rigid contact lenses, and 3 subjects wearing hydrogel contact lenses. Each of the 12 subjects provided, on 6 separate occasions, 100 microliters of tears. The pH of the tears was measured with a closed chamber, temperature stabilized micro-electrode system firstly on collection and then after titration with acid and base. In all, 28 titration steps across the acid-base spectrum were completed for each subject's tears on each occasion. These tear pH responses to acid-base challenge were compared to that of unbuffered distilled water for the same titration procedure. There was no statistically significant effect of contact lens wear on tear buffering capacity, but considerable inter-subject variability was noted. 相似文献
6.
PURPOSE: The change/no-change procedure (J. E. Sussman & A. E. Carney, 1989), which assesses speech discrimination, has been used under the assumption that the number of stimulus presentations does not influence performance. Motivated by the tenets of the multiple looks hypothesis (N. F. Viemeister & G. H. Wakefield, 1991), work by R. F. Holt and A. E. Carney (2005) called this assumption into question (at least for adults): Nonsense syllable discrimination improved with more stimulus presentations. This study investigates the nature of developmental differences and the effects of multiple stimulus presentations in the change/no-change procedure. METHOD: Thirty normal-hearing children, ages 4.0-5.9 years, were tested on 3 consonant-vowel contrasts at various signal-to-noise ratios using combinations of 2 and 4 standard and comparison stimulus repetitions. RESULTS: Although performance fell below that which is predicted by the multiple looks hypothesis in most conditions, discrimination was enhanced with more stimulus repetitions for 1 speech contrast. The relative influence of standard and comparison stimulus repetitions varied across the speech contrasts in a manner different from that of adults. CONCLUSION: Despite providing no additional sensory information, multiple stimulus repetitions enhanced children's discrimination of 1 set of nonsense syllables. The results have implications for models of developmental speech perception and assessing speech discrimination in children. 相似文献
7.
J M Carney W Cao L Logan O M Rennert T W Seale 《Pharmacology, biochemistry, and behavior》1986,25(4):769-773
The methylxanthine, theobromine (3,7-dimethylxanthine), was tested in mice, to determine whether theobromine could function in vivo as an adenosine receptor antagonist, in keeping with its reported in vitro effects as a blocker of agonist binding to the adenosine A-1 receptor. Theobromine doses, which themselves had no direct effects on spontaneous locomotor activity, completely blocked N6-cyclohexyladenosine-induced suppression of locomotor activity but were without effect on 5'-N-ethylcarboxamide adenosine (NECA)-induced decreases in motor activity. In contrast to the specific antagonism, theobromine blocked the hypothermia induced by both of these adenosine analogs. These results demonstrate that theobromine is an active in vivo adenosine receptor antagonist and that the antagonism of N6-cyclohexyladenosine sensitive systems occurs even though theobromine does not stimulate spontaneous locomotor activity. Thus, the behavioral stimulant effects of methylxanthines may be more related to effects on NECA-sensitive systems, which are not blocked by theobromine. The use of in vivo differences in the effects xanthine may provide a useful tool in the development of compounds to probe the mechanisms of caffeine induced CNS effects. 相似文献
8.
STUDY OBJECTIVE--In vitro investigations have indicated that adenosine can inhibit beta adrenergic stimulated increases in cardiac contractility. The present study was designed to determine the ability of adenosine to inhibit isoprenaline induced increases in contractility in vivo. Adenosine has been reported to exert its inhibitory effects on contractility by inhibiting adenylate cyclase. Thus, adenosine should have no effect on positive inotropic agents that act independently of adenylate cyclase. We therefore assessed the ability of this nucleoside to inhibit the positive inotropic effect of insulin, a hormone that exerts a positive inotropic effect independently of alterations in cyclic AMP. DESIGN--Saline or adenosine (10 mumol.ml-1) was infused into the circumflex artery at 1 ml.min-1 as a background. Isoprenaline (20 or 200 pmol.min-1) was infused into the artery during saline or adenosine infusion. The response to insulin was determined during hyperinsulinaemic euglycaemic clamp. SUBJECTS--16 adult mongrel dogs were anaesthetised with pentobarbitone. Five dogs were used in isoprenaline studies, and 11 dogs in insulin studies. MEASUREMENTS AND MAIN RESULTS--Dogs were instrumented to obtain measurements of mean arterial blood pressure, heart rate, circumflex artery blood flow (Q), instantaneous left ventricular pressure, and posterior left ventricular wall thickness. We used the slope of the end systolic pressure-dimension relationship (Ees) as an index of myocardial contractility, previously shown to reflect changes in myocardial inotropic state independent of influence from afterload and preload. Left ventricular dP/dtmax was derived from left ventricular pressure with respect to time, and Ees was determined from left ventricular pressure and wall thickness. Neither adenosine, isoprenaline, nor insulin alone caused any significant changes in mean arterial pressure or heart rate. Adenosine caused a significant increase in Q. Both left ventricular dP/dtmax and Ees were significantly increased by either insulin or both doses of isoprenaline. Adenosine inhibited the increases in these indices caused by isoprenaline, but not those caused by insulin. CONCLUSIONS--Adenosine is capable of inhibiting the positive inotropic effect of isoprenaline in vivo. The results suggest that adenosine does not inhibit positive inotropic responses that act independently of the stimulation of adenylate cyclase. 相似文献
9.
Production and secretion of neuroendocrine peptides by small cell lung cancer (SCLC) has been detected in the past years. Most recently the role of bombesin as an autocrine/paracrine growth modifier has been demonstrated. We used the soft agarose clonogenic assay to evaluate the influence of other neuroendocrine peptides on the in vitro proliferation of SCLC cell lines. Neuroendocrine peptides tested were adrenocorticotropic hormone, arginine vasopressin, calcitonin, glucagon, kassinin, neurotensin, physalaemin, somatostatin, and substance P. Experiments were carried out in serum-free and serum-supplemented media with and without serum-free incubation periods. Our results indicated that the amphibian undecapeptide physalaemin inhibits the clonal and mass culture growth of SCLC cell lines at picomolar concentrations. All other neuroendocrine peptides failed to influence SCLC growth in the test systems used. These results suggest a growth regulating effect of physalaemin and a potential new form of neuroendocrine peptide therapy for SCLC. 相似文献
10.
Digital radiography of subtle pulmonary abnormalities: an ROC study of the effect of pixel size on observer performance 总被引:3,自引:0,他引:3
Forty conventional radiographs with examples of mild interstitial infiltrates and subtle pneumothoraces and 40 normal studies of the chest were selected and digitized, with pixel sizes of 1.0, 0.5, 0.2, and 0.1 mm. Observer performance tests were carried out using receiver operating characteristic analysis. Conventional radiographs and digitized images were compared. The results indicate that, in such cases, diagnostic accuracy increases significantly as the pixel size is reduced, at least to the 0.1-mm level. We conclude that, for digital systems using screen-film or similar image receptors, use of a pixel size substantially larger than 0.1 mm may result in some loss of diagnostic accuracy. 相似文献