Chronic treatment with bovine growth hormone upregulates high-affinity hepatic somatotropic receptors in sheep

We evaluated the effect of chronic bovine growth hormone treatment on the hepatic somatotropic receptor. Growing lambs were treated with bGH at 0, 0.05, 0.15, 0.25 or 0.55 mg.kg-1.day-1 daily (N = 5/group) for 56 days. The binding of ovine GH to hepatic membranes washed with 4 mol/l MgCl2 and prepared in the presence of aprotinin was examined. The specific binding of oGH was increased (p less than 0.01) from 7.1 +/- 1.2% in saline-treated controls to 17.4 +/- 1.5% in the 0.55 mg.kg-1.day-1 group. Scatchard analysis showed curvilinear plots that best fitted a two-site model in 22/25 livers. The two sites had estimated dissociation constants (Kd) of 3 to 13 nmol/l for the low-affinity site and a Kd ranging from 0.17 to 0.31 nmol/l for the high-affinity site. Treatment with bGH had no consistent effect on the affinity of either binding site. However, bGH therapy was associated with a dose-dependent increase (p less than 0.01) in the number of high-affinity somatotropic receptors. There was no effect of bGH therapy on the concentration of low-affinity binding sites. The concentration of high-affinity receptors correlated with weight gain (r = 0.54, p less than 0.01), fat content (r = -0.54, p less than 0.01), protein content (r = 0.40, p less than 0.05), and plasma IGF-I (r = 0.57, p less than 0.005). The concentrations of low-affinity binding sites showed no such correlations.(ABSTRACT TRUNCATED AT 250 WORDS)     

PFO closure complications from the AGA registry

Objectives: To evaluate all complications that occurred during or after cardiac catheterizations for Amplatzer PFO device closure of patent foramen ovale (PFO), determine the cause of the complications and recommend techniques to minimize complications in the future. Background: Rare complications were reported to the manufacturer of the Amplatzer PFO occluder since the introduction of the device. Methods: A panel of independent physicians reviewed all complications reported to the manufacturer to determine whether the complication was related to the device or related to the cardiac catheterization procedure. Demographic data, echocardiograms, operative reports, and time to occurrence of complications were reviewed. Results: A total of 11 events were reported. Only two patients had device related complications (erosion), an incidence of 0.018%. Two patients were found to have additional atrial septal defect after PFO closure. Two patients were thought to have an inflammatory reaction without any serious sequelae. Five complications were related to the cardiac catheterization procedure (atrial appendage perforation). Conclusions: Device related complications after Amplatzer PFO occluder placement are extremely rare. Cardiac catheterization related complications appear to be the most common cause of the hemodynamic compromise. Careful manipulation of catheters and wires, recognition of the location of the catheter by fluoroscopy and echocardiography will decrease the risk of such complications. © 2008 Wiley‐Liss, Inc.     

Thoracentesis in patients with hematologic malignancy: yield and safety

BACKGROUND: Pleural effusions occur in patients with hematologic malignancies, particularly during periods of hospitalization. Thoracentesis is often performed to diagnose infection and to exclude the presence of complicated parapneumonic effusions. The efficacy and safety of thoracentesis in this setting has not been well-studied. DESIGN: Retrospective chart review of hospitalized patients with hematologic malignancies undergoing thoracentesis. The aim of this study was to assess the role of thoracentesis in establishing a diagnosis of infection in this population and to determine the risk of complications. RESULTS: A total of 100 thoracentesis findings were analyzed in patients with lymphoma (52 patients) and leukemia (27 patients), and in patients who had undergone bone marrow or stem cell transplantation (21 patients). The indication for performing thoracentesis was to exclude infection in 69% of cases. Fever was present in 59% of the patients, and a concomitant lung parenchymal abnormality was present in 69% of cases. Effusions were moderate to large in size (87% of cases), and were both bilateral (62%) and unilateral (38%). Exudates were documented in 83%of the cases. A specific diagnosis was found in 21 patients and was more frequently established in those with lymphoma (31%) compared to the other groups of patients. Diagnoses found included malignancy in 14 cases, chylous effusions in 6 cases, and infection in 1 case. The one patient in whom empyema was found required drainage. The criteria for a parapneumonic effusion were not found in any other patients. The complication rate of 9% (pneumothorax, seven patients; hemothorax, two patients) was comparable to that in other populations of patients. CONCLUSIONS: Despite a high propensity for developing pulmonary infections, hospitalized patients with hematologic malignancies rarely developed complex parapneumonic effusions. The etiology of many of the effusions that occurred in this setting was unclear.     

Pulmonary embolism in post-mortem material with clinical correlations in 425 cases

425 patients with pulmonary emboli at post mortem were studied retrospectively with the main focus on the clinical diagnosis. The diagnosis of pulmonary embolus was made or suspected while the patient was still alive in 59 patients (14%) and was first written in the post mortem request form in 130 patients (30%). In 236 patients (56%) the diagnosis was made only at post mortem. Even in fatal emboli the diagnosis was missed in 43% of cases. A multiplicity of non specific symptoms and signs was observed with a minority of patients showing signs and symptoms considered as typical. Of 231 thrombophlebitis processes found in locations which could give rise to clinical symptoms in the lower extremities the diagnosis was noted only in 25 cases. Chest x-ray and ECG were negative in two thirds of the cases. The high rate of misdiagnosis derived from two reasons: (a) subjective factors: lack of awareness; (b) objective difficulties: lack of specificity of clinical symptoms and signs as well as of results of the routine tests (chest x-ray and ECG). Since sophisticated confirmative tests for pulmonary emboli will be performed only on the basis of clinical suspicion, clinical awareness based on the observations detailed in this survey is still the cornerstone of diagnosis.     

Rifaximin, a nonabsorbed oral antibiotic, in the treatment of hepatic encephalopathy: antimicrobial activity, efficacy, and safety

The nonabsorbed (< 0.4%) oral antibiotic rifaximin, which has been available for enteric bacterial conditions for more than a decade in several countries outside the United States, was recently introduced in the United States for the treatment of travelers' diarrhea, and is being evaluated in clinical trials for possible introduction for hepatic encephalopathy and other conditions involving enteric bacteria. This article discusses the antimicrobial activity, efficacy, and safety of rifaximin in hepatic encephalopathy. Rifaximin is a nonsystemic antibiotic with antibacterial activity against enteric pathogens for gastrointestinal infections. In 15 studies, several of which were adequately powered to assess efficacy, rifaximin was at least as effective as lactulose/lactitol (the current mainstay of pharmacologic treatment for hepatic encephalopathy) and neomycin and paromomycin (the antibiotics most commonly prescribed for hepatic encephalopathy) in improving neurologic signs and symptoms and reducing blood ammonia levels. The results of studies employing small samples are similar to those of the larger studies. Finally, rifaximin has a good tolerability profile in patients with hepatic encephalopathy, and thus appears to constitute a promising new option for this disorder. The current database on rifaximin would be strengthened by results of placebo-controlled studies to quantify more precisely the benefits of therapy.     

Impact of stent deployment procedural factors on long-term effectiveness and safety of sirolimus-eluting stents (final results of the multicenter prospective STLLR trial)

Drug-eluting stent failures were associated with various clinical factors. However, the clinical impact of stent deployment technique was unknown. This study was designed to evaluate the frequency and impact of suboptimal percutaneous coronary intervention on long-term outcomes of 1,557 patients treated with sirolimus-eluting stents (SESs) in 41 US hospitals. All steps of the interventional procedure were scrutinized by an independent core laboratory to determine the occurrence of geographic miss (GM). GM included longitudinal (LGM; injured or diseased segment not covered by SES) or axial GM (balloon-artery size ratio <0.9 or >1.3) mismatches. Patients with and without GM were stratified (GM vs no-GM group). Patients, investigators, and the independent clinical event adjudication committee were blind to study group assignments. The primary end point was 1-year target-vessel revascularization (TVR) rate. Incidences and predictors of GM and safety outcomes were secondary end points. GM occurred in 943 patients (66.5%): 47.6% had LGM, 35.2% had axial GM, and 16.5% had both. One-year TVR rates were 5.1% in the GM group versus 2.5% in the no-GM group (p=0.025). TVR was 6.1% in the LGM versus 2.6% in the no-LGM subgroups (p=0.001). The association of GM with 1-year TVR was independent of clinical or anatomic factors (hazard ratio 2.0, 95% confidence interval 1.0 to 4.02, p=0.05). There was a 3-fold increase in myocardial infarction rates associated with GM (2.4% vs 0.8%; p=0.04). In conclusion, GM occurred frequently during SES implantation and was associated with increased risk of TVR and myocardial infarction at 1 year. These results emphasized the need for improvement in contemporary percutaneous coronary intervention practices and technologies.     

Presence of insulin-like growth factor-I receptors and absence of growth hormone receptors in the antler tip.

Red deer antler tips in the growing phase were removed 60 days after the recommencement of growth for autoradiographical studies and RRAs. Sections were incubated with radiolabeled GH or insulin-like growth factor-I (IGF-I), with or without excess competing unlabeled hormones, and were analyzed autoradiographically. There was negligible binding of [125I]GH in any histological zone of antler sections. [125I]IGF-I showed highest specific binding in the chondroblast zone to a receptor demonstrating binding characteristics of the type 1 IGF receptor. The lowest specific binding of [125I]IGF-I was to prechondroblasts. RRAs on antler microsomal membrane preparations RRAs on antler microsomal membrane preparations confirmed the absence of GH receptors and the presence of type 1 IGF receptors found by autoradiography. These findings suggest that IGF-I may act in an endocrine manner in antler growth through a receptor resembling the type 1 IGF receptor. The presence of type 1 receptors in the chondroblast zone implicates IGF-I involvement in cartilage formation through matrixogenesis. There is no support for IGF-I having a major role in mitosis in the antler.     

Saphenous vein graft disease

Saphenous vein graft (SVG) disease has been an obstinate problem facing the cardiologist since the early days of coronary artery bypass grafting (CABG) surgery. SVG disease follows temporally distinct phases of thrombosis, intimal hyperplasia and progressive atherosclerosis leading to recurrent ischemia which can be treated with repeat operation or percutaneous revascularization. However, repeat operation is associated with high mortality and morbidity. Also, percutaneous treatment of SVG disease is complicated by a high rate of procedural and long term complications due to the interrelated phenomena of distal embolization, slow flow or no reflow, periprocedure myocardial infarction, and subsequent restenosis. Long-term patency is poor in this patient population regardless of the treatment modality. Many pharmaceutical and device based approaches have been tested to avert these complications, but few, such as the use of distal protection devices, have shown benefit. The novel drug-eluting stents show promise in reducing the occurrence of restenosis and solving one of the problems associated with the percutaneous treatment of SVG disease. The pathogenesis and therapeutic options for SVG disease is reviewed in this article.