Kinetics of human erythrocyte acetylcholinesterase inhibition by a novel derivative of physostigmine: phenserine

The elastic properties of carotid arteries of spontaneously hypertensive rats (SHR) and normotensive controls (Wistar-Kyoto rats [WKY]) were examined in vivo, in situ, and in vitro. The changes of internal diameter were measured with a high-resolution A-mode echo-tracking device simultaneously with the intra-arterial pressure at the carotid. The internal diameter at mean arterial blood pressure (MBP) was substantially smaller in vitro than in vivo in SHR (-33.8%) and WKY (-48.3%). The arterial distensibility was lower in vitro in all arteries compared with in vivo conditions (SHR, -30.1%; WKY, -60.4%; at MBP) despite a reduced incremental elastic modulus in vitro (SHR, -56.9%; WKY, -45.1%; at MBP). However, the in vitro and in vivo measurements show consistent elastic behavior of the carotid arteries between both strains of rats. Carotid arteries from WKY were also examined in situ. Although no significant reduction in internal diameter could be observed in situ, distensibility was dramatically decreased (-87% at MBP). These results emphasize the importance of considering the original vascular geometry when determining elastic properties of arteries. We conclude that experimental conditions are likely to be a critical determinant for the assessment of the mechanical properties of conduit vessels.     

Subcellular localization and some biochemical properties of the flavivirus Kunjin nonstructural proteins NS2A and NS4A

1. The mean incidence of deaths from ascites in the UK in 1993 was 1.4% (0.7% in 1991 and 0.9% in 1992) and 0.8% from sudden death syndrome (SDS). In total, the economic loss to the UK Broiler Industry in 1993 as a result of these 2 conditions was 24 Pounds M. 2. Clear geographical differences emerged in the occurrence of ascites, with, not only the lowest incidences being observed in Northern Ireland, but also the peak of the mortality from ascites occurring much later in the rearing cycle than in other regions on the mainland. 3. In all regions the incidence of SDS was lower than that of ascites but the reason for this disparity remains to be established. 4. Some of the variables associated with the road transportation of day-old chicks from the hatchery to the farm appeared to influence the incidence of ascites. These included distance or time travelled, stocking density, internal lorry temperature and the length of time the lorry was heated before transport as well as the time the shed was heated before chick arrival. Temperature was also an important factor during growth (brooding and finishing). 5. Negative pressure-powered ventilation was preferred in most organisations but more ascites was seen with positive pressure ventilation. However, the lowest incidence of ascites occurred with natural ventilation. There was more ascites relative to shed orientation when the wind direction was from the west compared to the east. 6. This survey identifies the extent of the problem of broiler ascites in the UK and also highlights the importance of good management control of day-old chicks, not only following placement, but even before their arrival on the farm.     

Dietary cholestyramine reduces ochratoxin A-induced nephrotoxicity in the rat by decreasing plasma levels and enhancing fecal excretion of the toxin

Ochratoxin A (OTA) is a mycotoxin that may contaminate animal feed (oat, barley, and rye) and food (wheat, rice, coffee, beer, pig meat), leading to major health problems (e.g., nephropathy) in several animal species including humans. Several methods have been tested to reduce the toxicity of OTA in animals but with limited success. In rats, the effect of cholestyramine (CHA), a bile acid-binding resin, was investigated on OTA-induced nephrotoxicity and bioavailability. Animals were fed semisynthetic diets containing two levels of OTA: 1 or 3 ppm. At each level of OTA, the diets were enriched with 0.1, 1, and 5% of CHA. The results showed that CHA decreased the concentration of OTA in plasma. At 1 and 3 ppm of OTA in the diet, CHA is effective at a level of 0.1% and 5%, respectively. The excretion of OTA and its metabolites (ochratoxin alpha and hydroxylated ochratoxin A) in bile and urine was also decreased by addition of 5% CHA in the diet. This was associated with an increase of OTA excretion in feces. Enzymuria and renal morphology revealed that dietary CHA can decrease OTA-induced nephrotoxicity, probably by reducing renal exposure to the toxin. In conclusion, CHA can reduce OTA concentrations in plasma as well as reducing nephrotoxicity, which may be attributed to a decrease of bioavailability and/or enterohepatic circulation of the toxin.     

Treatment outcome with radiation therapy after breast augmentation or reconstruction in patients with primary breast carcinoma

BACKGROUND: Analyses were performed to determine local control and cosmetic outcome of breast carcinoma patients with prosthetically augmented or reconstructed breasts who had received radiation therapy (RT). METHODS: Twenty-one newly diagnosed breast carcinoma patients with prosthetically augmented or reconstructed breasts were treated with external beam RT. All patients received whole breast RT (median dose, 50.4 gray [Gy]) and 19 were boosted to a median dose of 60.4 Gy. A median dose of 50.4 Gy was delivered to the regional lymph nodes in 12 patients. Tissue equivalent bolus material was used in six patients. Seventeen patients received adjuvant systemic therapy. Cosmetic results were evaluated at 3-6-month intervals. RESULTS: With a median follow-up of 32 months, good/excellent cosmetic results were observed in 71% of patients (100% in those with augmented breasts and 54% in those with reconstructed breasts). Four patients (19%) with fair/poor cosmetic outcomes required implant removal and/or revision. Multiple clinical and treatment-related factors were analyzed for their impact on cosmetic outcome. A worsened cosmetic result was observed with increasing stage (P = 0.076), breast reconstruction (vs. augmentation) (P = 0.030), and bolus application (P = 0.016). All patients with fair/poor cosmetic outcomes had time intervals from implant insertion to RT ranging from 53-213 days. Two patients developed an isolated local recurrence within the augmented breast. CONCLUSIONS: Patients with prosthetically augmented breasts can undergo RT and expect good/excellent cosmetic results. Patients with reconstructed breasts are at a significantly greater risk for cosmetic failure. This risk may be related to the higher percentage of patients with advanced disease, those who received bolus application, and those who received earlier delivery of RT (after the cosmetic procedure) in reconstructed breasts.     

The impact of treatment time and smoking on local control and complications in T1 glottic cancer

Low frequency impedance measurements of pure egg lecithin (phosphatidylcholine) bilayers have revealed the presence of four layers which can be attributed to the acyl chain, carbonyl, glycerol bridge and phosphatidylcholine regions of the lecithin molecule. Measurements on bilayers formed in the presence of unoxidised-cholesterol revealed that cholesterol molecules were located in the hydrocarbon region of the bilayer with its hydroxyl groups aligned with the carbonyl region of the lecithin molecules. Measurements of oxidised-cholesterol lecithin bilayers revealed that these molecules protruded less into the hydrocarbon region and their polar hydroxyl group aligned with the glycerol bridge region of the lecithin molecule.     

Use of continuous stacking hybridization in sequencing using modified oligonucleotide matrices

The opportunity of DNA sequencing by hybridization with oligonucleotide matrix (SHOM) with simultaneously use continuous stacking hybridization and gapped-matrices is considered. The analysis of reconstruction efficiency for various combinations matrices and l-oligonucleotides libraries were made. In most cases combine use of continuous stacking hybridization and gapped matrices permits to decrease the number of additional stacking hybridization twice without lost of efficiency.     

The island posterior calf fasciocutaneous flap: an alternative to the gastrocnemius muscle for cover of knee and tibial defects

By repeatedly presenting an alien scent to territory-owning beavers, Castor canadensis, we tested two competing hypotheses about the function of scent marking: scent fence and scent matching. The scent-fence hypothesis predicts that territory owners should respond increasingly strongly over time towards a recurrent alien scent because of the ineffectiveness of previous responses. The scent-matching hypothesis predicts that the intensity of response should be the same or decrease because, without the presence of the intruding signaller coupled with the chemical signal, the presence of the scent itself does not advertise the ownership of a territory. The response level of resident beaver families was stable to strangers' anal gland secretions (AGSs) and decreased to strangers' castoreum during a period of 6 days. These results support the scent-matching hypothesis but not the scent-fence hypothesis. Copyright 1998 The Association for the Study of Animal Behaviour. Copyright 1998 The Association for the Study of Animal Behaviour.     

Codistribution of procathepsin B and mature cathepsin B forms in human prostate tumors detected by confocal and immunofluorescence microscopy

Ascorbic acid can recycle alpha-tocopherol from the tocopheroxyl free radical in lipid bilayers and in micelles, but such recycling has not been demonstrated to occur across cell membranes. In this work the ability of intracellular ascorbate to protect and to recycle alpha-tocopherol in intact human erythrocytes and erythrocyte ghosts was investigated. In erythrocytes that were 80% depleted of intracellular ascorbate by treatment with the nitroxide Tempol, both 2,2'-azobis(2-amidinopropane) dihydrochloride (AAPH) and ferricyanide oxidized alpha-tocopherol to a greater extent than in cells not depleted of ascorbate. In contrast, in erythrocytes in which the intracellular ascorbate concentration had been increased by loading with dehydroascorbate, loss of alpha-tocopherol was less with both oxidants than in control cells. Protection against AAPH-induced oxidation of alpha-tocopherol was not prevented by extracellular ascorbate oxidase, indicating that the protection was due to intracellular and not to extracellular ascorbate. Incubation of erythrocytes with lecithin liposomes also generated an oxidant stress, which caused lipid peroxidation in the liposomes and depleted erythrocyte alpha-tocopherol, leading to hemolysis. Ascorbate loading of the erythrocytes delayed liposome oxidation and decreased loss of alpha-tocopherol from both cells and from alpha-tocopherol-loaded liposomes. When erythrocyte ghosts were resealed to contain ascorbate and challenged with free radicals generated by AAPH outside the ghosts, intravesicular ascorbate was totally depleted over 1 h of incubation, whereas alpha-tocopherol decreased only after ascorbate was substantially oxidized. These results suggest that ascorbate within the erythrocyte protects alpha-tocopherol in the cell membrane by a direct recycling mechanism.