Who suffers most from leg ulceration?

This study examines health-related quality of life (HRQoL) in patients with leg ulceration and determines which patient groups are affected most by this condition. A cross-sectional study using the Nottingham Health Profile (NHP) and age/sex-matched normal scores in patients entering six clinical audit cycles was carried out. The 758 patients included in the study (mean age 74.6 years, 64% women) had been affected by leg ulceration for a median of 10.5 months (range 0.5 to 708). Patients produced significantly higher scores than age/sex-matched normal values for all domains of the NHP, indicating poorer HRQoL (all p < 0.001). Increasing age led to greater deficits in energy (p < 0.001) and mobility (p < 0.001) with greater social isolation (p = 0.044). Women experienced poorer energy, sleep patterns, mobility and emotional reactions (all p < 0.001), and increased physical pain and social isolation (p < 0.05) compared to men. However, higher scores may be expected for older women based on age/sex-matched normal values. After adjustment for age/sex-matched normal values, it was the younger patients who experienced a greater deficit in HRQoL over all domains of the NHP, with men scoring higher than women in the domains of bodily pain, sleep and social isolation (p < 0.001) and energy (p = 0.015). Leg ulceration has a major impact on patients' HRQoL as detected by the NHP. The excess in scores compared with age/sex-matched normal values indicate that it is younger male patients in whom ulceration makes a greater impact on HRQoL.     

Surface segregation of phosphorus, carbon, and sulfur in commercial low-carbon grades of steel

Surface segregation behavior of solute atoms has been studied on low-carbon steels used in producing galvannealed sheet steels for automotive body panel applications. Samples of cold-rolled low-carbon steels with different amounts of carbon and phosphorus in solution were heated in a vacuum chamber and their surface chemistries analyzed by Auger electron spectroscopy. For the steels studied here, one or more of the elements carbon, phosphorus, and sulfur accumulated significantly at the surface within a temperature window of 300 to 973 K. As the temperature was increased, carbon appeared on the surface first, followed by phosphorus, and then sulfur. Each succeeding segregating element displaced the previous one from the surface. The free solute concentration in the bulk and the temperature were critical factors controlling the amount of solute accumulation at the surface. Once segregated, the solute atoms remained on the surface as the samples cooled. Carbon and/or boron in steels retarded the transport of phosphorus to the surface. The implications of these findings in understanding the galvannealing behavior of these steels are discussed.     

Polymeric cryoprotectants in the preservation of biological ultrastructure. III. Morphological aspects.

Two high molecular weight polymers, polyvinylpyrrolidone (PVP) and hydroxyethyl starch (HES), have been used as cryoprotectants for preparing specimens to be freeze fractured. Solutions of 25% (w/w) suppress the formation of intracellular ice in single cells and tissue blocks from both plants and animals to the extent that fine structural details of the cell can be elucidates. The mode of action of these cryoprotectants, together with the structures they reveal and the peculiar advantages attached to their use, is discussed.     

Variations of bacterial populations in human feces measured by fluorescent in situ hybridization with group-specific 16S rRNA-targeted oligonucleotide probes

Six 16S rRNA-targeted oligonucleotide probes were designed, validated, and used to quantify predominant groups of anaerobic bacteria in human fecal samples. A set of two probes was specific for species of the Bacteroides fragilis group and the species Bacteroides distasonis. Two others were designed to detect species of the Clostridium histolyticum and the Clostridium lituseburense groups. Another probe was designed for the genera Streptococcus and Lactococcus, and the final probe was designed for the species of the Clostridium coccoides-Eubacterium rectale group. The temperature of dissociation of each of the probes was determined. The specificities of the probes for a collection of target and reference organisms were tested by dot blot hybridization and fluorescent in situ hybridization (FISH). The new probes were used in initial FISH experiments to enumerate human fecal bacteria. The combination of the two Bacteroides-specific probes detected a mean of 5.4 x 10(10) cells per g (dry weight) of feces; the Clostridium coccoides-Eubacterium rectale group-specific probe detected a mean of 7.2 x 10(10) cells per g (dry weight) of feces. The Clostridium histolyticum, Clostridium lituseburense, and Streptococcus-Lactococcus group-specific probes detected only numbers of cells ranging from 1 x 10(7) to 7 x 10(8) per g (dry weight) of feces. Three of the newly designed probes and three additional probes were used in further FISH experiments to study the fecal flora composition of nine volunteers over a period of 8 months. The combination of probes was able to detect at least two-thirds of the fecal flora. The normal biological variations within the fecal populations of the volunteers were determined and indicated that these variations should be considered when evaluating the effects of agents modulating the flora.     

An organ culture method for adult colon from germfree and conventional mice: effects of donor age and carcinogen treatment on epithelial mitotic activity

An organ culture system by which adult mouse colon epithelium could be maintained in a modified form for several weeks was described. The effects of donor age and carcinogen pretreatment were studied as a preliminary to proposed experiments on the effect of carcinogen treatment in vitro on colon epithelium from mice of different ages. Mitotic activity was compared in explants of colon from germfree C57BL mice 5 weeks, 5 months, and 9 months old; no differences were detected. The effect of old age on mitotic activity was not studied, since colon epithelium from old (30 mo) conventional mice could not be maintained in culture. Colon explants from conventional mice that had been pretreated for 32 weeks with weekly doses of a carcinogen, 1,2-dimethylhydrazine, appeared to have a higher potential for mitotic activity in vitro than did those from age-matched, untreated controls, but the difference was only significant at the 10% level. The epithelial cells were normal in ultrastructure, and the method may be valuable for studies of the direct effects of substances on adult colon epithelium.     

Conditioning and personality: A study of normal and neurotic subjects.

"Pavlov's concepts of excitation and inhibition were related to the dimension of introversion-extraversion in normal and neurotic subjects. Normal and neurotic subjects were conditioned, using the eyeblink and PGR reflexes. It was found that (a) anxiety states conditioned much better than hysterics, and (b) conditionability is related to introversion-extraversion and not to neuroticism." 37 references. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Impedance characterization and modeling of electrodes for biomedical applications

A low electrode-electrolyte impedance interface is critical in the design of electrodes for biomedical applications. To design low-impedance interfaces a complete understanding of the physical processes contributing to the impedance is required. In this work a model describing these physical processes is validated and extended to quantify the effect of organic coatings and incubation time. Electrochemical impedance spectroscopy has been used to electrically characterize the interface for various electrode materials: platinum, platinum black, and titanium nitride; and varying electrode sizes: 1 cm2, and 900 microm2. An equivalent circuit model comprising an interface capacitance, shunted by a charge transfer resistance, in series with the solution resistance has been fitted to the experimental results. Theoretical equations have been used to calculate the interface capacitance impedance and the solution resistance, yielding results that correspond well with the fitted parameter values, thereby confirming the validity of the equations. The effect of incubation time, and two organic cell-adhesion promoting coatings, poly-L-lysine and laminin, on the interface impedance has been quantified using the model. This demonstrates the benefits of using this model in developing better understanding of the physical processes occurring at the interface in more complex, biomedically relevant situations.     

Investigation of multidrug resistance in cultured human renal cell carcinoma cells by 31P-NMR spectroscopy and treatment survival assays

KTCTL-26 and KTCTL-2 are renal cell carcinoma (RCC) lines with high and lowexpression of P-170 glycoprotein, respectively. Inherent differences between the two cell lines in terms of phosphate metabolites and growth characteristics in culture were examined for possible association with multidrug resistance (MDR). Differences in response to drug treatment were investigated for 40 h incubations with various doses of vinblastine (VBL) alone or as cotreatments with various concentrations of the calcium antagonist diltiazem (DIL) and/or interferon–α (IFN-α). Treatment effects were quantitated using the MTT survival assay and ³¹P magnetic resonance spectroscopy (MRS) to determine phosphate metabolite profiles in intact cells. KTCTL-2 and KTCTL-26 cells exhibited significant inherent differences in phosphocholine, glycerophosphocholine, glycerophosphoethanolamine, and phosphocreatine levels. KTCTL-26 cells were more sensitive than KTCTL-2 to 0.011μM VBL alone (87% vs. 102% survival) or to 0.011μM BL + 10μM DIL (55% vs. 80% survival). The latter treatment resulted in a significant decrease in the ratio of phosphocholine to glycerophosphocholine in KTCTL-26 cells but no significant changes in phosphate metabolites in KTCTL-2 cells. Metabolomic ³¹P MRS detects different metabolite profiles for RCC cell lines with different MDR phenotypes and may be useful for noninvasive characterization of tumors in a clinical setting.This revised version was published online in August 2005 with a corrected sequence of authors.