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Biomedical subjects

S Shields

Publications and source records attributed to S Shields.

14 recordsLinked to original sources
PubMed2006

Endoscopic retrograde cholangiopancreatography after pancreaticoduodenectomy for benign and malignant disease: indications and technical outcomes.

BACKGROUND AND STUDY AIMS: Patients undergoing pancreaticoduodenectomy develop postoperative complications related to surgery and their disease. Very little data are available on the role or success of endoscopic retrograde cholangiopancreatography (ERCP) in such patients. The aim of this study was to evaluate the indications and role of diagnostic and therapeutic ERCP after pancreaticoduodenectomy for both benign and malignant disease. PATIENTS AND METHODS: This study was a 10-year (1990 - 2000) single institution retrospective review of all ERCPs performed on patients who had undergone pancreaticoduodenectomy surgery. Indications for the ERCP and technical procedural success were studied. RESULTS: 29 patients with a pancreaticoduodenectomy underwent 56 ERCPs. Reasons for surgery were neoplasia and chronic pancreatitis. Indications for ERCP included evaluation of jaundice and pain. Technical success related to the clinical indication (jaundice 69 %, pain 54 %). CONCLUSION: ERCP plays an important role in the management of postpancreatic surgery problems including biliary and anastomotic strictures, and should be the modality of choice. However, surgical technique may make the afferent limb inaccessible, and the ductal anastomosis difficult to identify in patients with some types of pancreaticoduodenectomy. Closer collaboration between surgeon and endoscopist may allow alterations in surgical technique to improve postoperative ERCP success.

Balloon Occlusion↗
PubMed2001

Bradykinin and nerve growth factor release the capsaicin receptor from PtdIns(4,5)P2-mediated inhibition.

Tissue injury generates endogenous factors that heighten our sense of pain by increasing the response of sensory nerve endings to noxious stimuli. Bradykinin and nerve growth factor (NGF) are two such pro-algesic agents that activate G-protein-coupled (BK2) and tyrosine kinase (TrkA) receptors, respectively, to stimulate phospholipase C (PLC) signalling pathways in primary afferent neurons. How these actions produce sensitization to physical or chemical stimuli has not been elucidated at the molecular level. Here, we show that bradykinin- or NGF-mediated potentiation of thermal sensitivity in vivo requires expression of VR1, a heat-activated ion channel on sensory neurons. Diminution of plasma membrane phosphatidylinositol-4,5-bisphosphate (PtdIns(4,5)P2) levels through antibody sequestration or PLC-mediated hydrolysis mimics the potentiating effects of bradykinin or NGF at the cellular level. Moreover, recruitment of PLC-gamma to TrkA is essential for NGF-mediated potentiation of channel activity, and biochemical studies suggest that VR1 associates with this complex. These studies delineate a biochemical mechanism through which bradykinin and NGF produce hypersensitivity and might explain how the activation of PLC signalling systems regulates other members of the TRP channel family.

Animals↗
PubMed2001

Group I metabotropic glutamate antagonist reduces acute neuronal degeneration and behavioral deficits after traumatic brain injury in rats.

Recent studies indicate that acute activation of Group I mGluRs following traumatic brain injury (TBI) contributes to the ensuing pathophysiology. The present study examined the effects of post-TBI administration of the selective mGluR1 antagonist (RS)-1-aminoindan-1,5-dicarboxylic acid (AIDA) on acute neuronal degeneration in the hippocampus and long-term sensorimotor and learning/memory outcome. In Experiment 1, 26 rats received 0.4, 2.0, or 10.0 nmol AIDA or artificial CSF vehicle infusion into the hippocampus starting 5 min postinjury. At 24 h after TBI characteristic pyramidal cell degeneration was observed in Fluoro-Jade-stained coronal sections of the CA2/3 sectors of the dorsal hippocampus. The mean (+/-SEM) number of Fluoro-Jade-positive neurons in the 10 nmol AIDA group (184 +/- 32) was significantly less (P < 0.05) than the vehicle group (310 +/- 47). In Experiment 2, 20 rats were trained on sensorimotor and memory tasks prior to parasagittal fluid percussion TBI. Rats were administered 10 nmol AIDA or vehicle as in Experiment 1. Rats were assessed on beam walking and radial arm maze (RAM) performance weekly for 6 weeks after TBI. Acquisition of a Morris water maze (MWM) task was assessed on days 11-15 after TBI. The AIDA-treated group had significantly reduced deficits in beam walk, MWM, and RAM performance compared to the vehicle-treated group. These data indicate that injury-induced acute activation of mGluR1 receptors contributes to both the cellular pathology and the behavioral morbidity associated with TBI.

Animals↗
PubMed2001

A comparison of patients' responses about their disability with and without attribution to their affected area.

The purpose of this study was to determine whether individual items in a disability questionnaire were answered differently depending on whether or not the questions were attributed to the upper limb (i.e., "do you have difficulty eating due to your arm or hand problem?" or "do you have difficulty eating?", respectively). The a priori hypothesis was that the same or more disability would be detected by nonattributed items. Four hundred sixty-seven patients with upper extremity disorders completed the SF-36 general health survey, which does not attribute health problems to affected areas. Patients also completed six additional questions, modified from the SF-36, regarding work (four questions) and social function with friends and family (two questions), which attributed their disability to their affected upper extremity. Of 467 patients, 419-431 (89-92%) responded to both versions of the questions. Although we demonstrated a significant order effect (Generalized Estimating Equation; P=.003), comparison of the responses to the six questions showed that for five of the six questions (Generalized Estimating Equation; P< or = .001) patients reported more disability when the questions were worded with attribution to the upper extremity. Even considering the order effect, patients demonstrated a counterintuitive result by reporting more disability when questions were attributed to their affected area. Thus, both the wording of questions and order of questions can significantly affect patients' responses about their disability and raises questions about the validity of patients' reports of their disability.

Adult↗
PubMed1988

The role of ultrasound in the management of retinopathy of prematurity.

The authors reviewed the ultrasonic appearance of 54 eyes (27 patients) with advanced retinopathy of prematurity (ROP) and compared the various retinal configurations with the findings at surgery. They found that ultrasound is a sensitive indicator of retinal configuration (type and degree of retinal detachment [RD]), as well as showing the existence of subretinal or choroidal hemorrhage often present in these severely affected eyes. Ultrasound is a useful modality to evaluate, document, and follow the progression of RD in ROP.

Choroid Hemorrhage↗
PubMed1988

Transpupillary argon laser cyclophotocoagulation in the treatment of glaucoma.

Twenty-seven patients with glaucoma, which could not be controlled with maximum tolerable medication and standard laser techniques, underwent transpupillary argon laser cyclophotocoagulation. Only six patients (22.3%) had a successful outcome, and the postoperative course in many cases was complicated by an additional, sustained increase in intraocular pressure. Notwithstanding these results, the procedure may be useful occasionally to preclude the need for conventional glaucoma surgery.

Adolescent↗
PubMed1987

Developmental changes in calmodulin-kinase II activity at brain synaptic junctions: alterations in holoenzyme composition.

Synaptic junctions (SJs) from rat forebrain were isolated at increasing postnatal ages and examined for endogenous protein kinase activities. Our studies focused on the postnatal maturation of the multifunctional protein kinase designated Ca2+/calmodulin-dependent protein kinase II (CaM-kinase II). This kinase is comprised of a major 50-kilodalton (kDa) and a minor 60-kDa subunit. Experiments examined the developmental properties of CaM-kinase II associated with synaptic plasma membranes (SPMs) and synaptic junctions (SJs), as well as the holoenzyme purified from cytosolic extracts. Large developmental increases in CaM-kinase II activity of SJ fractions were observed between postnatal days 6 and 20; developmental changes were examined for a number of properties including (a) autophosphorylation, (b) endogenous substrate phosphorylation, (c) exogenous substrate phosphorylation, and (d) immunoreactivity. Results demonstrated that forebrain CaM-kinase II undergoes a striking age-dependent change in subunit composition. In early postnatal forebrain the 60-kDa subunit constitutes the major catalytic and immunoreactive subunit of the holoenzyme. The major peak of CaM-kinase II activity in SJ fractions occurred at approximately postnatal day 20, a time near the end of the most active period of in vivo synapse formation. Following this developmental age, CaM-kinase II continued to accumulate at SJs; however, its activity was not as highly activated by Ca2+ plus calmodulin.

Aging↗
PubMed1976

Reversibility of hepatic failure following jejunoileal bypass.

Jejunoileal bypass was performed in 50 morbidly obeses patients. The morbidity encountered compared favorably with that of other series. All patients manifesting hepatic failure demonstrated hyperbilirubinemia within the first three months postoperatively. Hyperbilirubinemia, if uncorrected, resulted in a mortality of 75%. Augmentation jejunal interposition was performed in three patients who demonstrated hepatic decompensation or severe electrolyte imbalance or both. This resulted in rapid correction of electrolyte disturbances, liver function measurements, and patient symptoms without significant postoperative weight gain. Persistent hyperbilirubinemia or recalcitrant electrolyte problems or both are indications for augmentation jejunal interposition.

Body Weight↗
PubMedDate not supplied

Reliability of isometric wrist extension torque using the LIDO WorkSET for late follow-up of postoperative wrist patients.

The objectives of this study were to determine interobserver, intraobserver, and overall reliability of isometric wrist extension torque using the LIDO WorkSET and then to estimate the minimal level of detectable change using the standard error of measurement. A generalizability study was conducted on 18 postoperative patients. Primary outcome was mean torque of three trials. Variance components were used to calculate generalizability coefficients for intraobserver (G = 0.96), interobserver (G = 0.94), and overall reliability (G = 0.92). When the same therapist is evaluating a patient on different days, a change of more than 16 inch-lb is needed to be 90% confident that true change has occurred. A greater value for change (23 inch-lb) is required when different therapists evaluate a patient on different days. The LIDO WorkSET measures wrist torque in a reproducible manner in an applied setting. The testing protocol is sensitive to differences in wrist torque between individuals and tolerated in the late postoperative period.

Adult↗