Expression of alpha2-adrenergic receptors in rat primary afferent neurones after peripheral nerve injury or inflammation.
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1. Immunocytochemistry with polyclonal antibodies directed against specific fragments of intracellular loops of alpha2A- and alpha2C-adrenergic receptors (alpha2A-AR, alpha2C-AR) was used to explore the possibility that expression of these receptors in dorsal root ganglion (DRG) neurones of rat alters as a result of peripheral nerve injury or localized inflammation. 2. Small numbers of neurones with positive alpha2A-AR immunoreactivity (alpha2A-AR-IR) were detected in DRG from normal animals or contralateral to nerve lesions. In contrast, after complete or partial sciatic nerve transection the numbers of ipsilateral L4 and L5 DRG somata expressing alpha2A-AR-IR sharply increased (>5-fold). There was no discernible change in the number of DRG neurones exhibiting alpha2A-AR-IR innervating a region in association with localized chemically induced inflammation. 3. After nerve injury, double labelling with Fluoro-Gold, a marker of retrograde transport from transected fibres, or by immunoreactivity for c-jun protein, an indicator of injury and regeneration, suggested that many of the neurones expressing alpha2A-AR-IR were uninjured by the sciatic lesions. 4. In general the largest proportionate increase in numbers of neurones labelled by alpha2A-AR-IR after nerve lesions appeared in the medium-large diameter range (31-40 microm), a group principally composed of cell bodies of low threshold mechanoreceptors. The number of small diameter DRG neurones labelled by alpha2A-AR-IR, a category likely to include somata of nociceptors, also increased but proportionately less. 5. Relatively few DRG neurones exhibited alpha2C-AR-IR; this population did not appear to change after either nerve lesions or inflammation. 6. These observations are considered in relation to effects of nerve injury on excitation of primary afferent neurones by sympathetic activity or adrenergic agents, sympathetically related neuropathy and reports of sprouting of sympathetic fibres in DRG. (+info)
Neurogenic origin of articular hyperemia in early degenerative joint disease.
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It has been speculated that joint instability resulting from anterior cruciate ligament (ACL) rupture could be exacerbated by changes in vasomotor activity in the remaining supporting structures. In this study, the effect of ACL transection on medial collateral ligament (MCL) basal perfusion and its responsiveness to calcitonin gene-related peptide (CGRP) and sympathetic adrenergic influences was examined. Using urethan-anesthetized rabbits, we tested the effects of CGRP and its antagonist CGRP-(8-37) by topical application of these agents to the exposed knee while sympathetic influences were tested by electrically stimulating the saphenous nerve. It was found that MCL basal perfusion was elevated in ACL-sectioned joints; however, this effect was abrogated by prior resection of the articular nerve supply. At the doses tested, the normal vasodilator response to CGRP was abolished in ACL-sectioned joints, whereas the response to CGRP-(8-37) was attenuated. Even under the influence of increased constrictor tone, MCL and capsule blood vessels still showed substantially reduced responses to exogenous CGRP administration. By contrast, nerve-mediated constrictor responses were mostly unaffected by joint instability. This study suggests that posttraumatic knee joint hyperemia is neurogenically mediated, possibly by increased secretion of CGRP. (+info)
Prognosis of perforating eye injury.
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The assessment of visual function in a series of 130 consecutive patients of perforating eye injuries, revealed that visual acuity of 6/12 or better was regained in 63 per cent, between 6/60 and 6/18 in 9-2 per cent, less than 6/60 in 15-3 per cent, and enucleation was necessary in 9-2 per cent. In 3 per cent, the eyes were retained as blind, symptomfree, and cosmetically satisfactory organs. Two eyes were found to develop complete traumatic aniridia. None in the series was found to have sympathetic ophthalmitis. (+info)
Gastrointestinal injuries during gynaecological laparoscopy.
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A retrospective case review study was carried out on gastrointestinal injuries which occur during gynaecological laparoscopy. Fifty-six patients with 62 gastrointestinal injuries were identified. One-third of the complications (32.2%) occurred during the installation phase for laparoscopy. Four of the six complications attributed to electrosurgery were secondary to the use of monopolar coagulation. Diagnosis of these gastrointestinal injuries was made during surgery in only 20 patients (35.7%). The mean time before diagnosis was 4.0 +/- 5.4 (range 0-23) days. Treatment of these complications was performed by laparoscopic surgery in 16.1% of cases. Prevention relies on the surgeon's experience, strict observance of the safety rules, perfect familiarity with the physical properties of the instruments used, systematic use of bowel preparation for patients presenting a risk of bowel complications, systematic supervision of the route taken by the trocars, meticulous inspection on completion of surgery of all areas where bowel adhesiolysis has been used and, in case of any doubt, tests for leakage involving the rectosigmoid. For patients with a risk of bowel complications, the creation of a pneumoperitoneum and performing a mini laparoscopy in the left hypochondrium can be the judicious option. (+info)
A 4-year-old boy presented with a transorbital-transpetrosal penetrating head injury after a butter knife had penetrated the left orbit. The knife tip reached the posterior fossa after penetrating the petrous bone. Wide craniotomy and the pterional, subtemporal, and lateral suboccipital approaches were performed for safe removal of the object. The patient was discharged with left-sided blindness, complete left ophthalmoplegia, and hypesthesia of the left face. Early angiography is recommended to identify vascular injury which could result in fatal intracranial hemorrhage. (+info)
Corneal wound healing in tenascin knockout mouse.
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PURPOSE: Tenascin (TN) is a large hexameric extracellular matrix glycoprotein that is expressed in developing organs and tumors. It has also been reported that TN is expressed in the embryonic cornea and during corneal wound healing. However, the role of TN in the cornea is not fully known. In this study, the role of TN in corneal wound healing was examined using the TN knockout (KO) mouse. METHODS: Two different injuries (a linear perforation wound and two 10-0 nylon suture wounds) were made separately on the corneas of both TNKO and congenic wild-type mice. The corneal wound healing was compared histologically, and the expression of TN and fibronectin (FN) on the injured cornea was examined immunohistochemically and by immunoblot analysis. RESULTS: Based on histologic analysis, there was no significant difference in the wound healing process between wild-type and TNKO mice in the linear incision experiment. However, the corneal stromata of TNKO mice were compressed prominently and devoid of migrating keratocytes in suture injury, which induced a more significant amount of TN than perforation wounds. Although FN expression on the sutured corneas of TNKO mice was upregulated during suture injury, the amount of FN protein was smaller than that of wild-type mice at the same time points after injury. CONCLUSIONS: In suture wounds, TN appears to enhance the amount of FN expression, and a lack of TN may impair stromal cell migration. TN plays a significant role in corneal wound healing, especially for wounds with mechanical stress. (+info)
Needlestick and sharps injuries among health-care workers in Taiwan.
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Sharps injuries are a major cause of transmission of hepatitis B and C viruses and human immunodeficiency virus in health-care workers. To determine the yearly incidence and causes of sharps injuries in health-care workers in Taiwan, we conducted a questionnaire survey in a total of 8645 health care workers, including physicians, nurses, laboratory technicians, and cleaners, from teaching hospitals of various sizes. The reported incidence of needlestick and other sharps injuries was 1.30 and 1.21 per person in the past 12 months, respectively. Of most recent episodes of needlestick/sharps injury, 52.0% were caused by ordinary syringe needles, usually in the patient units. The most frequently reported circumstances of needlestick were recapping of needles, and those of sharps injuries were opening of ampoules/vials. Of needles which stuck the health-care workers, 54.8% had been used in patients, 8.2% of whom were known to have hepatitis B or C, syphilis, or human immunodeficiency virus infection. Sharps injuries in health-care workers in Taiwan occur more frequently than generally thought and risks of contracting blood-borne infectious diseases as a result are very high. (+info)
Recurrent carotid blowout syndrome: diagnostic and therapeutic challenges in a newly recognized subgroup of patients.
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BACKGROUND AND PURPOSE: To our knowledge, recurrent carotid blowout syndrome (rCBS) has not been well described. Our purpose was to review our institution's recent experience with patients who presented with multiple episodes of carotid blowout syndrome (CBS), and who were referred for emergent diagnostic angiography and endovascular therapy. METHODS: We retrospectively reviewed the last 46 consecutive patients who had a clinical diagnosis of CBS. All patients were examined and treated prospectively according to a standardized protocol. Most patients (43 of 46) had undergone extensive primary and salvage radical surgery with intraoperative brachytherapy or external beam radiation or both. The remaining three patients had either traumatic or iatrogenic CBS. RESULTS: Twelve patients (26%) in our series had more than one episode of CBS in which a total of 32 (20 recurrent) events were observed (average 2.7, range 2-4). Intervals of rCBS ranged from 1 day to 6 years. Thirteen (65%) of 20 recurrent events were attributed to progressive disease (PD), and seven (35%) of 20 to treatment failures (TFs). In the PD group, seven (54%) of 13 had recurrent ipsilateral disease, and six (46%) of 13 had recurrent contralateral disease. Etiologies of rCBS were as follows: seven exposed carotids; seven carotid pseudoaneurysms; eight small-branch pseudoaneurysms; five tumor hemorrhages; three hyperemic/ulcerated wounds; and one aortic arch rupture. Twenty-seven of 32 events were treated with endovascular therapy, which included the following: nine carotid occlusions; 11 small-branch embolizations; three transarterial tumor embolizations; one carotid stent; and two direct-puncture embolizations. Four of six TFs were retreated successfully with endovascular therapy; the remaining two TFs were managed successfully by surgery. In the PD group, hemorrhagic complications of rCBS were managed successfully in all but one patient, who died. No permanent neurologic or ophthalmologic complications occurred. CONCLUSION: Recurrent CBS is a frequently encountered problem in which most cases are caused by PD resulting from both multifocal iatrogenic arteriopathy and occasional wound complications that are characteristic of aggressively managed head and neck surgical patients. Initial TFs are encountered often as well. Despite the diagnostic and therapeutic challenges of rCBS, most cases can be retreated effectively. (+info)