Effects of S-carboxymethyl-l-cysteine on pulmonary sialyl transferase activity in vitro, in healthy and in sulphur-dioxide-induced bronchitic rats

S-carboxymethyl-L-cysteine (carbocysteine) improves the visco-elastic properties of bronchial mucus in vivo, possibly as a result of an increase in the relative proportions of sialomucins in bronchial mucus. Carbocysteine was therefore studied in vitro and ex vivo in both normal and bronchitic rats on pulmonary sialyl transferase, responsible for the addition of sialic acid to mucus glycoproteins. Bronchitis was induced in male Sprague-Dawley rats by repeated exposure to sulphur dioxide for two weeks. During this time they received either 500 mg kg-1 day-1 carbocysteine or its vehicle by the oral route. Rats not being exposed to SO2 received the same treatment. The animals were then killed, and subcellular fractions prepared by differential centrifugation of lung homogenates. Sialyl transferase was assayed using CMP-14C sialic acid as substrate and desialysed fetuin as exogenous acceptor. Enzyme activity was located in both the (Golgi-containing) 10,000 g and 100,000 g pellets with minor activity in the cytosolic supernatants. When tested in vitro between 10(-6) and 10(-3) M, carbocysteine had no effect on sialyl transferase activity in microsomes taken from healthy or bronchitis rats. Repeated administration of carbocysteine was without effect on the sialyl transferase activity in 10,000 g pellets taken from healthy rats. However, in bronchitic rats there was a small but statistically significant (P less than 0.05) increase in enzymic activity in the treated group compared to the animals receiving the vehicle. There was no difference in the activity of the microsomal enzyme compared to vehicle-treated controls in either healthy or bronchitic rats. We conclude that it is possible that an increase in sialyl transferase activity in a Golgi-containing fraction of bronchitic lungs could explain the relative increase in sialomucins in bronchitic subjects.     

Undifferentiated (embryonal) sarcoma of the liver: radiologic- pathologic correlation

Undifferentiated (embryonal) sarcoma (UES) is an uncommon malignant mesenchymal hepatic tumor that occurs in older children and young adults. Fourteen cases are correlated with radiologic and pathologic findings. Radiologic findings reflect the spectrum of solid to cystic appearances observed in the gross specimens. Sonography typically demonstrates a large mass that may be predominantly solid with many small anechoic spaces or may be cystic. Computed tomography reveals a hypodense mass with hyperdense septa of variable thickness and a dense peripheral rim corresponding to the fibrous pseudocapsule of the tumor. Angiographically, UES is usually hypovascular with tumoral vessels, although hypervascular and avascular patterns occur. Prognosis of UES is poor, with a median survival of less than 1 year. Radiologists should be familiar with this malignant tumor since it may present as a large cystic hepatic mass, suggestive of a benign lesion.     

Use of bivariate survival curves for analyzing mortality of heart failure and sudden death in dilated cardiomiopathy

This paper discusses the use of bivariate survival curves estimators within the competing risk framework. Competing risks models are used for the analysis of medical data with more than one cause of death. The case of dilated cardiomiopathy is explored. Bivariate survival curves plot the conjoint mortality processes. The different graphic representation of bivariate survival analysis is the major contribute of this methodology to the competing risks analysis.     

Insulin signalling pathways in aorta and muscle from two animal models of insulin resistance--the obese middle-aged and the spontaneously hypertensive rats

AIMS/HYPOTHESIS: The aim of this study was to investigate insulin signalling pathways directly in vivo in skeletal muscle and thoracic aorta from obese middle-aged (12-month-old) rats, which have insulin resistance but not cardiovascular disease, and from spontaneously hypertensive rats (SHR), an experimental model of insulin resistance and cardiovascular disease. METHODS: We have used in vivo insulin infusion, followed by tissue extraction, immunoprecipitation and immunoblotting. RESULTS: Obese middle-aged rats and the SHR showed marked insulin resistance, which parallels the reduced effects of this hormone in the insulin signalling cascade in muscle. In aortae from obese middle-aged rats, the PI 3-kinase/Akt pathway is preserved, leading to a normal activation of endothelial nitric oxide synthase. In SHR this pathway is severely blunted, with reductions in eNOS protein concentration and activation. Both animals, however, showed higher concentrations and higher tyrosine phosphorylation of mitogen-activated protein (MAP) kinase isoforms in aortae. CONCLUSIONS/INTERPRETATION: Alterations in the IRS/PI 3-K/Akt pathway in muscle of 12-month-old rats and SHR could be involved in the insulin resistance of these animals. The preservation of this pathway in aorta of 12-month-old rats, apart from increases in MAP kinase protein concentration and activation, could be a factor that contributes to explaining the absence of cardiovascular disease in this animal model. However, in aortae of SHR, the reduced insulin signalling through IRS/PI 3-kinase/Akt/eNOS pathway could contribute to the endothelial dysfunction of this animal.     

Radioimmunoassay of factor V in human plasma and platelets

Homogeneous, single-chain human factor V was used to develop a double antibody competition radioimmunoassay to measure factor V concentrations in plasma and platelets. Standard curves were constructed that allow for the detection of as little as 20 ng factor V/ml of plasma. Normal factor V concentrations range from 4 to 14 micrograms/ml of plasma with an average value of 7.0 +/- 2.0 micrograms/ml (n = 64). No correlation was observed between antigen levels and age or sex. The radioimmunoassay data are consistent with factor V clotting assays, providing freshly drawn plasma is used in the bioassay. Radioimmunoassay of washed platelets indicate that 0.63-1.93 microgram of factor V is present per 2.5 X 10(8) platelets (4612-14128 molecules of the factor V platelet). When normalized to individual hematocrits and platelet count, the data indicated that platelets contribute approximately 18%-25% of the factor V found in whole blood. In addition, two individuals with functionally deficient factor V were examined and found to be deficient in both antigen and activity.     

Electrochemical synthesis and characterization of poly(4,4′(5′)-bis[(3,4-(ethylenedioxy)thien-2-yl]tetrathiafulvalene) films: A new TTF–bithiophene regular copolymer

Anodic coupling of 4,4′(5′)-bis[(3,4-(ethylenedioxy)thien-2-yl]tetrathiafulvalene (1) in acetonitrile has produced a new polythiophene-based polymer containing tetrathiafulvalene (TTF) moieties regularly inserted in the polythiophene chain. The polymer poly(1) has been compared with poly(3-[7-oxa-8-(4-tetrathiafulvalenyl)octyl]-2,2′-bithiophene) bearing the TTF moieties as pendant groups. The polymer films were characterized by cyclic voltammetry, FTIR reflection–absorption and UV–vis spectroscopy, in situ ESR and in situ conductivity. The reversible oxidation of the polymers in two one-electron steps at the TTF moiety displays characteristics which suggest a faster electron transfer and a higher redox conductivity for poly(1).     

The role of implantable cardioverter defibrillator for primary vs secondary prevention of sudden death in patients with idiopathic dilated cardiomyopathy.

AIM: To analyse the characteristics and outcome of patients with idiopathic dilated cardiomyopathy (DC) considered at high risk of sudden death (SD) and treated with implantable cardioverter defibrillators (ICD) for primary prevention (Group A) in comparison with patients treated with ICDs because of previous sustained ventricular tachyarrhythmias or syncope (Group B). METHODS: Group A consisted of 27 patients with at least two of the following criteria: left ventricular end-diastolic diameter (LVEDD) > or =70 mm (74%), LV ejection fraction (LVEF) < or =30% (78%), non-sustained ventricular tachycardia (VT) (56%), long history of disease (> or =48 months since diagnosis, 85%) and family history of SD (11%). Group B consisted of 27 patients treated with ICDs because of sustained VT/fibrillation (n=18) or syncope (n=9). RESULTS: NYHA class, LVEF, LVEDD and amiodarone treatment were similar in the two groups. Patients in group A were younger (46+/-15 vs 59+/-17 years, P=0.0008), were more often treated with beta-blockers (89% vs 62%; P=0.02) and had a longer interval since diagnosis (86+/-60 vs 40+/-50 months; P=0.004). Twelve month rates of appropriate intervention (AI) were 41% in Group A and 57% in group B (P NS). In group A, after a mean follow-up of 21+/-14 months, patients showing the combination of LVEF < or =30% and LVEDD > or =70 mm had the highest frequency of AI (76% vs 10%, P=0.005). In group B, after a mean follow-up of 33+/-23 months, 78% of patients with syncope had AI. Total and sudden deaths were 11% and 4% in group A and 19% and 4% in group B (P NS). CONCLUSIONS: Patients with idiopathic DC treated with ICD for primary prevention because they were considered at high risk of SD according to clinical criteria showed a high rate of AI, similar to that of patients treated for secondary prevention. The highest rate of AI was seen in patients with both severe dysfunction and dilatation and in those with previous syncope.     

Discrimination of normal and abnormal prothrombin and protein C in plasma using a calcium ion-inhibited monoclonal antibody to a common epitope on several vitamin K-dependent proteins

Vitamin K deficiency or administration of vitamin K antagonists results in the biosynthesis of abnormal des-gamma-carboxy forms of the vitamin K-dependent proteins. Monoclonal antibody H-11 binds several vitamin K- dependent proteins at a determinant that includes the first two residues of gamma-carboxyglutamic acid. Antibody H-11 binds fully carboxylated prothrombin and protein C in the presence of EDTA but binding is inhibited by the divalent metal ions, calcium, magnesium, and manganese. By contrast, des-gamma-carboxy prothrombin and protein C bind antibody H-11 the same in the presence of EDTA or calcium ion. Antibody H-11 thus appears to bind a conserved antigenic site containing gamma-carboxyglutamic acid that in the presence of divalent metal ion undergoes a conformational transition. This ability of antibody H-11 to bind des-gamma-carboxy prothrombin and protein C in the presence of calcium ion allowed the development of an immunoassay for these proteins in plasma. Prothrombin and protein C from stably anticoagulated individuals receiving warfarin were characterized by their ability to bind antibody H-11 in the presence of calcium ion. Binding of prothrombin and protein C to antibody H-11 in the presence of calcium correlated temporally with warfarin administration. The inability of calcium ion to inhibit binding of antibody H-11 to abnormal prothrombin and protein C in plasma suggests that the circulating forms of both proteins following warfarin administration cannot undergo the metal ion-dependent conformational transition that includes sequence residues 1 through 12.     

Topical steroids for chronic wounds displaying abnormal inflammation

Introduction

Chronic, non-healing wounds are often characterised by an excessive, and detrimental, inflammatory response. We review our experience of using a combined topical steroid, antibiotic and antifungal preparation in the treatment of chronic wounds displaying abnormal and excessive inflammation.

Methods

A retrospective review was undertaken of all patients being treated with a topical preparation containing a steroid (clobetasone butyrate 0.05%), antibiotic and antifungal at a tertiary wound healing centre over a ten-year period. Patients were selected as the primary treating physician felt the wounds were displaying excessive inflammation. Healing rates were calculated for before and during this treatment period for each patient. Changes in symptom burden (pain, odour and exudate levels) following topical application were also calculated.

Results

Overall, 34 ulcers were identified from 25 individual patients (mean age: 65 years, range: 37–97 years) and 331 clinic visits were analysed, spanning a total time of 14,670 days (7,721 days ‘before treatment’ time, 6,949 days ‘during treatment’ time). Following treatment, 24 ulcers demonstrated faster rates of healing, 3 ulcers showed no significant change in healing rates and 7 were healing more slowly (p=0.0006). Treatment generally reduced the burden of pain and exudate, without affecting odour.

Conclusions

In normal wound healing, inflammation represents a transient but essential phase of tissue repair. In selected cases, direct application of a steroid containing agent has been shown to improve healing rates, presumably by curtailing this phase. Further evaluation is required to establish the role of preparations containing topical steroids without antimicrobials in the management of chronic wounds.