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171.
Recurrent hyperparathyroidism due to parathyroid autografts: incidence, presentation, and management
Recurrent hyperparathyroidism (HPT) occurs in a small percentage of patients undergoing parathyroidectomy for primary HPT and is usually due to inadequate excision of hyperfunctioning parathyroid tissue in the neck, a missed ectopic and hyperplastic parathyroid, or, less commonly, parathyroid carcinoma and parathyroid autografts. In order to determine the incidence, clinical characteristics, and outcome of patients with recurrent HPT due to parathyroid autografts, we reviewed our experience with 604 consecutive patients operated on for primary HPT between 1965 and 1989. One hundred of these patients received parathyroid autografts consisting of portions of one or more parathyroid glands. Three patients with autografts, placed in the sternocleidomastoid muscle, developed recurrent HPT due to their autografts for an incidence of 3 per cent. Recurrent disease was diagnosed between 62 and 113 months with an average of 89 months. The autotransplants in all three of these patients were from hyperplastic or adenomatous parathyroid tissue. Two patients had a history of neck irradiation. Preoperative thallium scans accurately localized the hyperfunctioning parathyroid tissue in all three patients. At operation, the hyperfunctioning autografts had grown into a discrete mass with a single vascular pedicle and were resected. Histologic examination disclosed either hyperplastic or adenomatous tissue, and corresponded to the histology and location of the original tissue transplanted in each case. Follow-up ranges from 12 to 67 months, with an average of 48 months. All patients remain cured and none require oral calcium supplementation. We conclude that graft-dependent recurrent HPT is due to the autotransplantation of hyperplastic or adenomatous parathyroid tissue and that thallium scanning is instrumental for diagnosis and localization.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
172.
173.
FH Wapstra H Van Goor G Navis PE De Jong D De Zeeuw 《Canadian Metallurgical Quarterly》1996,90(5):393-401
1. The mechanism of renal protection by angiotensin-converting enzyme inhibition is still the subject of debate. Inhibition of proteinuria might play a role. If so, a good antiproteinuric response to angiotensin-converting enzyme inhibition should predict subsequent protection against renal structural damage. This hypothesis has not been tested in models where treatment is started after the renal disease is well established, i.e. models that mimic the clinical situation. 2. We therefore investigated this hypothesis in 96 male Wistar rats with established adriamycin nephrosis. Reduction of proteinuria was achieved by lisinopril (0, 2, 5 and 10 mg day-1 kg-1) on two different sodium diets (0.3% and 0.05% NaCl). Therapy started 6 weeks after adriamycin (at stable proteinuria) and was continued for 6 weeks. 3. Lisinopril reduced blood pressure by 32 +/- 4% and proteinuria by an average of 72 +/- 7%, with stabilization after 2 weeks. Considerable interindividual differences in antiproteinuric response was found. Glomerulosclerosis score was reduced by 15 +/- 5%. All the effects of angiotensin-converting enzyme inhibitors were enhanced by sodium depletion, but sodium depletion in itself did not affect blood pressure (124 +/- 4 mmHg), proteinuria (664 +/- 68 mg/day) or glomerulosclerosis score (30 +/- 5%). Interestingly, the more proteinuria was reduced initially in an individual rat, the less sclerosis was found in the long term in that rat. 4. In conclusion, angiotensin-converting enzyme inhibition lowers proteinuria and prevents glomerulosclerosis in established adriamycin nephrosis. These effects are enhanced by sodium depletion. The individual short-term antiproteinuric effect predicts the protection against ultimate glomerular damage. This is consistent with the hypothesis that reduction of proteinuria is a mechanism by which angiotensin-converting enzyme inhibitors exert renoprotection. 相似文献
174.
Kuhn R. De Mori R. 《IEEE transactions on pattern analysis and machine intelligence》1995,17(5):449-460
This article describes a new method for building a natural language understanding (NLU) system, in which the system's rules are learnt automatically from training data. The method has been applied to design of a speech understanding (SU) system. Designers of such systems rely increasingly on robust matchers to perform the task of extracting meaning from one or several word sequence hypotheses generated by a speech recognizer. We describe a new data structure, the semantic classification tree (SCT), that learns semantic rules from training data and can be a building block for robust matchers for NLU tasks. By reducing the need for handcoding and debugging a large number of rules, this approach facilitates rapid construction of an NLU system. In the case of an SU system, the rules learned by an SCT are highly resistant to errors by the speaker or by the speech recognizer because they depend on a small number of words in each utterance. Our work shows that semantic rules can be learned automatically from training data, yielding successful NLU for a realistic application 相似文献
175.
A dedicated low-power CMOS transponder microchip is presented as part of a novel telemetry implant for biomedical applications. This mixed analog-digital circuit contains an identification code and collects information on physiological parameters, i.e., body temperature and physical activity, and on the status of the battery. To minimize the amount of data to be transmitted, a dedicated signal processing algorithm is embedded within its circuitry. All telemetry functions (encoding, modulation, generation of the carrier) are implemented on the integrated circuit. Emphasis is on a high degree of flexibility towards sensor inputs and internal data management, extreme miniaturization, and low-power consumption to allow a long implantation lifetime 相似文献
176.
M Pérez-Encinas JL Bello S Pérez-Crespo R De Miguel S Tome 《Canadian Metallurgical Quarterly》1994,46(3):225-229
Familial chronic myeloproliferative syndrome (CMS) was observed in five members from two different generations of the same kindred. Diagnosis included agnogenic myeloid metaplasia (case 1), polycythemia vera (case 2), and essential thrombocythemia (cases 3-5). Cases 1-3 were siblings, case 5 was the daughter of case 1, and case 4 was the cousin of cases 1, 3. Age at diagnosis ranged from 28 to 75 years, cases 1 and 3 were male, and the others were female. The diagnosis was made after an episode of cerebral thrombosis in one patient, during a study for headache and dizziness in another, and fortuitously in the three remainders. All patients had splenomegaly and varying degrees of thrombocytosis. The cytogenetic exam was normal in all four cases. A woman patient was treated with interferon during a pregnancy. Fetal growth was retarded, and the newborn showed bone and genital malformations. No environmental leukemogen factor was found. This familial case strengthens Dameshek's theory of a common pathogenesis of CMS and suggests a genetic and hereditary etiology. 相似文献
177.
Examined whether male and female students of high mathematical ability use different solution strategies on math problems that had previously yielded gender differences in correct responding. Structured interviews were conducted with high school students who had scored at least 670 on the math portion of the Scholastic Aptitude Test (SAT-M). Eight types of solution strategies could be further dichotomized as conventional or unconventional in approach. Female students were more likely than male students to use conventional strategies. SAT-M scores were correlated with positive attitudes (confidence and persistence) toward math: use of conventional strategies was correlated with negative attitudes (dislike, nonrelevance) toward math. Findings may help to explain patterns of gender differences on SAT-M problems among high-ability students in which female students outperform male students on conventional problems and male students outperform female students on unconventional problems. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
178.
Posture and gesture analysis, together with the monitoring of body kinematics, is a field of increasing interest in bioengineering and several connected disciplines. In this paper, some typical features of distributed sensing systems are described, as well as a methodology to read signals from such systems. Theory, simulation, results, and some specific applications are shown. Strain gauges have been used as sensors and have been deposited directly onto textile fibers, demonstrating one way to realize a wearable sensor system. 相似文献
179.
180.
A. Palmeri F. Ricciardelli G. Muscolino A. De Luca 《Canadian Metallurgical Quarterly》2004,130(9):1052-1061
The equation of motion of linear dynamic systems with viscoelastic memory is usually expressed in a integrodifferential form, and its numerical solution is computationally heavy. In two recent papers, the writers suggested that the system memory be accounted for through the introduction of a number of additional internal variables. Following this approach, the motion of the system is governed by a set of first-order, linear differential equations, whose solution is quite easy. In this paper, the approach is extended to single-degree-of-freedom systems subjected to random, nonstationary excitation. The equations governing the time variation of the second-order statistics are derived, and an effective step-by-step solution procedure is proposed. Numerical example shows the accuracy of the procedure for white and nonwhite excitations. 相似文献