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Biomedical subjects

J A Murray

Publications and source records attributed to J A Murray.

At least 73 records · Page 4Linked to original sources

Angiographic embolization of bilateral internal iliac arteries to control life-threatening hemorrhage after blunt trauma to the pelvis.

Angiographic embolization of bleeding pelvic vessels is increasingly used in patients with pelvic injuries. Temporary angiographic embolization of bilateral internal iliac arteries (TAEBIIA) is occasionally necessary. From November 1991 to March 1998, 30 consecutive patients (mean age of 43 years, mean Injury Severity Score of 25) with complex pelvic fractures underwent TAEBIIA to control severe hemorrhage not responding to subselective embolization. Angiography revealed multiple sources of pelvic bleeding in 28 (93%) patients. In the two remaining patients, no bleeding was identified but TAEBIIA was done empirically. Thirteen patients had laparotomies before TAEBIIA with unsuccessful bleeding control, and the remaining 17 had TAEBIIA as the primary treatment. After TAEBIIA 90 per cent of patients had successful clinical (27 of 30) and radiographic (25 of 28) control of bleeding. Of the three patients who continued to bleed after TAEBIIA two were successfully re-embolized and one died of acute cardiac failure before any further intervention was attempted. TAEBIIA had a success rate of 97 per cent (29 of 30) in controlling pelvic hemorrhage without significant complications related to it. TAEBIIA is a safe and effective alternative to subselective embolization in controlling retroperitoneal bleeding in selected patients with blunt pelvic trauma.

Adult↗

Pediatric falls: is height a predictor of injury and outcome?

Falls account for a significant proportion of pediatric injuries and deaths. A retrospective review of pediatric patients (age 0-14 years) was performed to determine whether patterns of injuries and outcomes could be predicted on the basis of the height of the fall. In addition we evaluated the triage criterion "fall greater than 15 feet" for transport of patients to a trauma center. Patients were stratified by the height of the fall: greater than or less than 15 feet. The end points for analysis were the associated injuries and survival. Patients who fell less than 15 feet had a higher incidence of intracranial injuries (and fewer extremity fractures than patients who fell more than 15 feet). Skull fractures were the most frequent injury and were associated with an increase in intracranial injuries in both subgroups. In conclusion low-level falls are associated with significant intracranial injuries. The evaluation of patients sustaining low-level falls should not be limited on the basis of the height of the fall. Using falls of greater than 15 feet as a triage criterion for transport to a trauma center needs to be prospectively evaluated to ensure that critically injured patients are triaged appropriately.

Accidental Falls↗

DNA damage triggers disruption of telomeric silencing and Mec1p-dependent relocation of Sir3p.

In eukaryotic cells, surveillance mechanisms detect and respond to DNA damage by triggering cell-cycle arrest and inducing the expression of DNA-repair genes [1]. In budding yeast, a single DNA double-strand break (DSB) is sufficient to trigger cell-cycle arrest [2]. One highly conserved pathway for repairing DNA DSBs is DNA non-homologous end-joining (NHEJ), which depends on the DNA end-binding protein Ku [3]. NHEJ also requires the SIR2, SIR3 and SIR4 gene products [4] [5], which are responsible for silencing at telomeres and the mating-type loci [6]. Because of the link between NHEJ and the Sir proteins, we investigated whether DNA damage influences telomeric silencing. We found that DNA damage triggers the reversible loss of telomeric silencing and relocation of Sir3p from telomeres. Complete Sir3p relocation was triggered by a single DNA DSB, suggesting that the singal is amplified. Consistent with this idea, Sir3p relocation depended on the DNA damage-signalling components Ddc1p and Mec1p. Thus, signalling of DNA damage may release Sir3p from telomeres and permit its subsequent association with other nuclear subdomains to regulate transcription, participate in DNA repair and/or enhance genomic stability by other mechanisms.

Bleomycin↗

Cytokinin activation of Arabidopsis cell division through a D-type cyclin.

Cytokinins are plant hormones that regulate plant cell division. The D-type cyclin CycD3 was found to be elevated in a mutant of Arabidopsis with a high level of cytokinin and to be rapidly induced by cytokinin application in both cell cultures and whole plants. Constitutive expression of CycD3 in transgenic plants allowed induction and maintenance of cell division in the absence of exogenous cytokinin. Results suggest that cytokinin activates Arabidopsis cell division through induction of CycD3 at the G1-S cell cycle phase transition.

Adenine↗

Lung-sparing surgery after penetrating trauma using tractotomy, partial lobectomy, and pneumonorrhaphy.

OBJECTIVE: To evaluate the role of lung-sparing surgical techniques in the surgical management of penetrating pulmonary injuries. DESIGN: Retrospective case series. SETTING: Academic level I trauma center. PATIENTS AND METHODS: Forty patients underwent thoracic surgery for penetrating lung injuries during a 63-month period from January 1993 to March 1997. Five (12.5%) underwent anatomical lobectomy, 3 (7.5%) pneumonorrhaphy, 9 (22.5%) stapled wedge resection, and 23 (57.5%) stapled tractotomy. In total, 34 patients (85%) were treated with stapling techniques (1 anatomical lobectomy, 1 pneumonorrhaphy, 9 stapled wedge resections, and 23 stapled tractotomies) and 35 (87.5%) underwent had lung-sparing surgery for trauma. RESULTS: Morbidity and mortality rates were 40% and 5%, respectively. Patients who underwent anatomical lobectomy required longer mechanical ventilatory support, intensive care unit stay, and hospital stay and had a higher morbidity rate compared with patients who underwent lung-sparing surgery for trauma but had central and extensive pulmonary injuries. Stapled tractotomy was efficient in controlling bleeding and bronchial leaks, but, in 3 patients, parts of the divided lung parenchyma were devascularized and had to be resected. CONCLUSIONS: Lung-sparing surgery for trauma with the use of staplers can be used in the majority of patients with penetrating pulmonary injuries requiring operation. Stapled tractotomy is a rapid and effective method for controlling hemorrhage and air leaks.

Adult↗

The effect of peroxynitrite on sphincter of Oddi motility.

BACKGROUND: Nitric oxide (NO*) is an inhibitory neurotransmitter that induces sphincter of Oddi relaxation. Superoxide (O*-2)-scavenging enzymes are present in enteric plexuses of the sphincter of Oddi and O*-2 alters sphincter of Oddi motor function. O*-2 rapidly oxidizes nitric oxide (NO*) to form peroxynitrite (ONOO-), thus terminating the biological activity of NO*. The aim of our study was to determine the effects of ONOO- on sphincter of Oddi motility in vitro. MATERIALS AND METHODS: Adult opossums were sacrificed and the sphincter of Oddi was removed and placed in a tissue bath containing oxygenated Krebs solution at 37 degreesC. In the first series of experiments, force transducers recorded tension in a transverse orientation at two sites along the spontaneously contracting sphincter of Oddi. In a second series of experiments, circular muscle strips were precontracted with carbachol and stimulated by an electrical field. RESULTS: ONOO-, superoxide dismutase (SOD), Nomega-nitro-l-arginine (l-NNA), or oxyhemoglobin were added to the tissue baths. ONOO- decreased the frequency of contractions in the spontaneously contracting sphincter of Oddi. Adding hemoglobin increased the frequency of contractions. ONOO- also increased the stimulation-induced relaxation compared to controls. The increase in relaxation induced by ONOO- was inhibited by oxyhemoglobin and l-NNA but not SOD. Pretreatment with oxyhemoglobin prevented the increase in the stimulation-induced relaxation caused by ONOO-. CONCLUSION: These results suggest that hemoglobin binds ONOO- or that ONOO- generates NO.

Animals↗

Angiographic embolization for arrest of bleeding after penetrating trauma to the abdomen.

BACKGROUND: Angiographic embolization is an effective technique to control bleeding after blunt trauma to the liver or pelvis. Its role in penetrating trauma to the abdomen has not been studied. METHODS: From January 1992 to May 1998, 40 patients underwent angiography for bleeding resulting from intra-abdominal penetrating injuries (33 gunshot wounds, 7 stab wounds). Angiographic embolization of intraperitoneal or retroperitoneal vessels was performed by standard angiographic techniques with gelatin sponge and/or coils. Data were extracted from medical records, radiology data bank, trauma registry, and morbidity/mortality records, and compared by Student's t test and chi-square test. The main outcome measures were failure of angiographic embolization to control bleeding and complications of angiographic embolization. RESULTS: Angiography was performed during a course of nonoperative management in 6 patients (group A), because of failure to control bleeding surgically in 23 (group B), and because of late vascular complications after an initially successful operation in 11 more (group C). In 32 patients, angiography revealed active bleeding; 29 (91 %) underwent successful angiographic embolization. Of the remaining 3 patients, 2 were successfully managed surgically (1 each from groups A and B) and 1 died despite multiple surgical maneuvers (group B). One patient who developed postoperatively a large, bleeding superior mesenteric artery pseudoaneurysm, suffered extensive bowel necrosis after angiographic embolization. No other significant complication was related to angiographic embolization. CONCLUSIONS: Angiographic embolization after penetrating injuries to the abdomen is safe and effective for a small number of selected patients. It is a valuable tool for bleeding control when surgery has failed. It may be ideal for control of late vascular complications when reoperation is not desirable. It may prove to be a useful adjunct in the nonoperative treatment of selected injuries.

Abdominal Injuries↗

Celiac disease and recurrent pancreatitis.

BACKGROUND: Celiac disease is associated with pancreatico-biliary disease. Postulated mechanisms include reduced gallbladder emptying due to impaired cholecystokinin release and pancreatitis due to malnutrition. We hypothesize that celiac disease may also be associated with pancreatico-biliary abnormalities due to duodenal inflammation and papillary stenosis. METHODS: Over a 48-month period, 169 patients referred for possible sphincter of Oddi dysfunction who underwent pancreatico-biliary manometry were tested for gliadin and endomysial antibodies. Duodenal and papillary biopsies were preformed in those patients who were positive. RESULTS: Celiac disease was diagnosed in 12 (7.1%; 3 men, 9 women). The mean age was 61 years as compared with 37 years for those patients without celiac disease. All of the celiac patients had been referred for recurrent abdominal pain and/or idiopathic pancreatitis. Ten had idiopathic recurrent pancreatitis with elevated amylase and lipase levels. Two of these patients also had mildly elevated liver function tests associated with the abdominal pain. Only 3 of 12 patients had a prior diagnosis of celiac disease. These 12 patients had manometric evidence of stenosis and histologic evidence of periampullary inflammation as well as histologic changes consistent with celiac disease. In 10 of 12 patients sphincterotomy or extension of a prior papillotomy was performed. Two patients were treated with a gluten-free diet alone. CONCLUSIONS: We describe 12 patients with papillary stenosis and celiac disease. In 9 cases the celiac disease was a new diagnosis. Celiac disease should be considered in the etiology of papillary stenosis or idiopathic recurrent pancreatitis.

Adult↗

The plant cell cycle.

Molecular controls of the plant cell cycle must integrate environmental signals within developmental contexts. Recent advances highlight the fundamental conservation of underlying cell cycle mechanisms between animals and plants, overlaid by a rich molecular and regulatory diversity that is specific to plant systems. Here we review plant cell cycle regulators and their control.

Cell Cycle↗

Retinoblastoma proteins in plants.

The retinoblastoma protein Rb is part of a conserved pathway that controls the activation of cell division in animals. Rb represses cell cycle transcription factors of the E2F family, and thereby prevents uncontrolled cell proliferation. Rb itself is inactivated when phosphorylated by cyclin-dependent kinases, and the D-type cyclin kinases are particularly important in this process during the reactivation of cell division in quiescent cells. In addition, Rb has important developmental roles in controlling the onset of cellular differentiation in a number of cell types. The recent discovery in plants of both Rb proteins and other components of the Rb pathway suggests that, far from being restricted to the animal kingdom, Rb may have a conserved role in allowing multicellular organisms to develop complex body plans consisting of many different cell types. This review assesses the potential roles of Rb proteins in plant cell cycle control and development.

Cell Division↗

Esophageal lichen planus: the Mayo Clinic experience.

Lichen planus (LP) is an inflammatory papulosquamous disease which may affect the squamous epithelium of the esophagus. We reviewed six patients with esophageal lichen planus (ELP) seen at Mayo Clinic Rochester between 1984 and 1998. The presenting symptoms were dysphagia (in all six patients) and odynophagia (two patients). Cervical esophageal strictures were seen in four patients; average number of esophageal dilatations required was 15 (range, 10-18). Esophageal biopsies demonstrated the classical histologic findings of ELP in two patients, and a lymphocytic infiltrate in the other four. Concomitant lichen planus (LP) was seen at other sites in five patients: all five had oral LP preceeded by ELP symptoms in all five; three had genital LP preceeded by ELP symptoms in all three; two had dermal LP, preceeded by ELP symptoms in one. Proton pump inhibitors were tried unsuccessfully in all patients. Four patients were started on systemic steroid medication; three had resolution of symptoms within 1 month.

Adult↗

The widening spectrum of celiac disease.

Celiac disease is a permanent intolerance to ingested gluten that results in immunologically mediated inflammatory damage to the small-intestinal mucosa. Celiac disease is associated with both human leukocyte antigen (HLA) and non-HLA genes and with other immune disorders, notably juvenile diabetes and thyroid disease. The classic sprue syndrome of steatorrhea and malnutrition coupled with multiple deficiency states may be less common than more subtle and often monosymptomatic presentations of the disease. Diverse problems such as dental anomalies, short stature, osteopenic bone disease, lactose intolerance, infertility, and nonspecific abdominal pain among many others may be the only manifestations of celiac disease. The rate at which celiac disease is diagnosed depends on the level of suspicion for the disease. Although diagnosis relies on intestinal biopsy findings, serologic tests are useful as screening tools and as an adjunct to diagnosis. The treatment of celiac disease is lifelong avoidance of dietary gluten. Gluten-free diets are now readily achievable with appropriate professional instruction and community support. Both benign and malignant complications of celiac disease occur but these can often be avoided by early diagnosis and compliance with a gluten-free diet.

Celiac Disease↗

Predicting the need for thoracoscopic evacuation of residual traumatic hemothorax: chest radiograph is insufficient.

BACKGROUND: The early removal of large residual posttraumatic hemothorax by videothoracoscopy is increasingly used to avoid the late sequelae of trapped lung and empyema. Plain chest radiography (CXR) is the tool most frequently used to select such cases for operation. Our recent experience has demonstrated that what appears to be a large retained hemothorax on CXR may turn out to be intrapulmonary or extrapleural conditions not amenable to thoracoscopic removal. Our objective was to evaluate the accuracy of CXR in detecting significant residual hemothorax and compare its clinical value to thoracic computed tomography (CT) when used to select patients for thoracoscopic evacuation. METHODS: All patients requiring tube thoracostomy for traumatic hemothorax were prospectively evaluated during a 22-month period (n = 703). Patients who, on the second day after admission, demonstrated opacification on CXR involving more than the costophrenic angle were evaluated by thoracic computed tomography for the presence of undrained fluid. Second-day CXR (CXR2) results were compared with the CT findings. Incorrect interpretation was defined as a difference of more than 300 mL between the two readings. All CXR2 and CT results were reviewed in the same fashion by a radiologist blinded to the surgeon's interpretations. Data on injury mechanism, hemodynamic status, laboratory values, interventions, and outcome were collected prospectively. RESULTS: Fifty-eight patients had clinically significant opacifications on CXR2. The surgeon's and radiologist's CXR2 interpretations were incorrect in 48 and 47% of the cases, respectively. The CT interpretations by the two specialists were in agreement in 97% of the cases. Management that would have been instituted on the basis of CXR2 findings was changed in 18 cases (31%). Twelve patients (21%) required early thoracoscopic evacuation of undrained collections. There was good correlation between the CT estimation and the thoracoscopically retrieved amount of blood. CONCLUSION: Although CXR is useful as a screening tool, it cannot be used to reliably select patients for surgical evacuation of retained traumatic hemothorax. Decision-making should be based on thoracic CT findings.

Adult↗