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121.
The effects of endotoxin (20 mg kg-1 i.p.) on the mesenteric vascular responses to acetylcholine, bradykinin, sodium nitroprusside, and to transient occlusion of the superior mesenteric artery were examined in rats anesthetized with pentobarbitone. Mesenteric vasodilator responses to close arterial injections of acetylcholine and bradykinin were reduced at 1.5 h after endotoxin and almost abolished by 4 h; responses to sodium nitroprusside were unaffected. Occlusion of the superior mesenteric artery for 30, 60, or 120 s produced, on release of the occlusion, a time-dependent vasodilator response in the mesenteric circulation (post-occlusion hyperemia). This hyperemia was markedly reduced by nitro-L-arginine methyl ester (L-NAME); L-NAME did not modify acetylcholine-induced vasodilation. Endotoxin-pretreatment did not modify mesenteric post-occlusion hyperemia 1.5 h after administration but markedly reduced the response by 2.5 h. The administration of L-NAME to endotoxin-treated rats did not further attenuate the hyperemic responses. Mesenteric vasoconstrictor responses to phenylephrine were not modified by endotoxin, although systemic pressor responses to this agent were impaired. We concluded that endotoxin impairs endothelium and nitric oxide-dependent vasodilator responses in the mesenteric circulation.  相似文献   
122.
BACKGROUND: Surgeons are often called upon to perform pancreaticoduodenectomy for either suspicion of malignancy or symptoms due to benign disease. Perioperative morbidity and mortality following pancreaticoduodenectomy have decreased markedly over the last 2 decades. In response, many surgical centers advocate expanding the indications for pancreaticoduodenectomy to include lesions other than periampullary carcinoma. PATIENTS AND METHODS: A retrospective review of medical records for 108 patients undergoing pancreaticoduodenectomy for benign disease at The Johns Hopkins Medical Institutions over 100 months was completed. The subset of patients with a histopathologic diagnosis of chronic pancreatitis was identified and compared with patients undergoing pancreaticoduodenectomy for other benign conditions. RESULTS: The mortality rate for the present series was less than 1%. Perioperative complications, the majority of which were self-limited, occurred in 51% of patients. The most common complication was delayed gastric emptying. Pancreatic anastamotic leak occurred in 18% of patients and developed significantly more frequently in patients with benign diseases other than chronic pancreatitis (31% versus 8%, P < 0.05). CONCLUSION: Among appropriately selected patients, the rates of perioperative mortality and serious morbidity are low, and concerns about mortality and morbidity should not prevent an aggressive approach to surgical resection in patients with benign disease.  相似文献   
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A 45-year-old man with a history of cyclophosphamide exposure underwent repeated ureteroscopy for positive urine cytology findings after resection of a Grade 2 papillary transitional-cell carcinoma of the bladder. Despite careful technique, an intussusception developed in the left ureter, which was repaired by resection and construction of a Boari flap. To our knowledge, this is the first report of retrograde ureteral intussusception caused by ureteroscopy.  相似文献   
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This study presents baseline and 3-month follow-up motor and neuropsychological data for 22 patients with Parkinson's disease (PD) who underwent anatomically guided unilateral posterior ventral pallidotomy (PVP). Postsurgical improvements were seen in psychomotor speed, fine motor accuracy, and dyskinesia, whereas grip strength decreased on the side contralateral to the surgery. No change was detected in overall level of cognitive functioning, nor were changes demonstrated in memory, language, or working memory when the entire sample of patients was evaluated. When the group was divided on the basis of side of surgery, patients with left-sided pallidotomies showed a decline in verbal fluency. Patients and caregivers reported improvement in psychosocial functioning. These initial findings of improved motor performance and largely unaffected cognitive functions are consistent with results obtained with functional PVP and provide support for the use of anatomically guided posterior ventral pallidotomy in the treatment of motor symptoms of PD.  相似文献   
127.
Selective termination is employed in multifetal pregnancies, in the presence of an abnormal fetus, in order to improve the prognosis of the normal fetuses. The term elective reduction is used to describe reduction in twin pregnancies for maternal medical conditions, psychological, or socioeconomic reasons. The purpose of this study was to evaluate the factors that influence outcome in such pregnancies. Eighty-two twin pregnancies underwent selective termination (n = 59) or elective reduction (n = 23) over a 10-year period. Early procedures, performed < or = 14 weeks (n = 31), had a pregnancy loss of 9.7% and a mean procedure-to-loss interval of 4.1 +/- 2.8 weeks; mean birthweight was 3299 +/- 395 g in survivors, with a mean gestational age at delivery of 38.4 +/- 2.3 weeks. In comparison, procedures performed > 14 weeks (n = 51) had a pregnancy loss of 7.8%, with a procedure-to-loss interval of 1.2 +/- 0.6 weeks. Mean birthweight was 2577 +/- 999 g, with a mean gestational age at delivery of 35.7 +/- 5 weeks. In conclusion, outcomes were more favourable among patients who underwent a first trimester procedure. The slight increase in pregnancy loss may be attributed to a higher than expected rate of spontaneous abortions in the first trimester, as manifested by the higher procedure-to-loss interval after a first trimester procedure. These facts underscore the importance of early detection of fetal abnormalities in twin pregnancies by ultrasonography and chorionic villus sampling.  相似文献   
128.
BACKGROUND: Significant changes are restructurng the U.S. health care delivery system. National health reform is now extending itself into the public sector. Increased health and medical costs by federal and state governments are forcing a reevaluation of major entitlement programs, especially Medicaid. METHODS/RESULTS: Because Medicaid is the single largest item in many state budgets, states are now enrolling Medicaid patients into managed and coordinated care arrangements as a means to control costs and increase access to care. HMOs are not only competing for private patients but also actively seeking the Medicaid population. Nationally, almost one-fourth of all Medicaid patients are now enrolled in managed care plans. Various models and approaches have been developed by individual states. CONCLUSIONS: Because managed care enrollment in the Medicaid program has increased substantially in recent years, selected services including vision care are no longer rendered by any practitioner willing to accept Medicaid fees. Freedom of choice is now restricted to pre-selected and panel practitioners participating with the managed care program. The rules, regulations, billing procedures, fees, and program requisites will differ under managed care programs. Private optometric practitioners must consider entering economic and organizational relationships and linkages that make them attractive to managed care organizations.  相似文献   
129.
The solution structure of robustoxin, the lethal neurotoxin from the Sydney funnel-web spider Atrax robustus, has been determined from 2D 1H NMR data. Robustoxin is a polypeptide of 42 residues cross-linked by four disulphide bonds, the connectivities of which were determined from NMR data and trial structure calculations to be 1-15, 8-20, 14-31 and 16-42 (a 1-4/2-6/3-7/5-8 pattern). The structure consists of a small three-stranded, anti-parallel beta-sheet and a series of interlocking gamma-turns at the C-terminus. It also contains a cystine knot, thus placing it in the inhibitor cystine knot motif family of structures, which includes the omega-conotoxins and a number of plant and animal toxins and protease inhibitors. Robustoxin contains three distinct charged patches on its surface, and an extended loop that includes several aromatic and non-polar residues. Both of these structural features may play a role in its binding to the voltage-gated sodium channel.  相似文献   
130.
Mycoplasma hyopneumoniae is the etiological agent of porcine enzootic pneumonia, a commercially expensive respiratory disease of swine. Salmonella typhimurium SL3261 was used as a live carrier of plasmid pKF1, which encodes a 15-kDa recombinant M. hyopneumoniae protein. This expressed recombinant protein consists of the carboxy-terminal 11 kDa of a 42-kDa M. hyopneumoniae NrdF ribonucleotide reductase R2 subunit protein. Rabbit anti-15-kDa serum was able to inhibit the growth of viable M. hyopneumoniae J in vitro. When used as a live oral vaccine, S. typhimurium SL3261(pKF1) induced a significant secretory immunoglobulin A immune response in the lungs of mice orally immunized against the M. hyopneumoniae antigen. Utilization of live oral vaccines expressing potentially protective M. hyopneumoniae proteins, such as the NrdF antigen, which can stimulate a lung mucosal response against surface-accessible proteins may provide a cost-effective alternative to the present control strategies used for porcine enzootic pneumonia.  相似文献   
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