Dehydrochlorination of poly(sulfonyl-co-2-chloroethylene)

Poly(sulfonyl-co-2-chloroethylene)s were shown to have an enhanced tendency to undergo dehydrochlorination compared with poly(vinyl chloride). Dehydrochlorination was observed under the following conditions: (a) during preparation of the copolymers by γ-radiation initiated copolymerization of vinyl chloride and sulfur dioxide, (b) by γ-irradiation of the polymer, (c) during ageing, (d) on heating and (e) in solution in basic solvents, such as DMSO. The dehydrochlorination was studied by microanalysis, by IR and UV spectroscopy and by ¹H and ¹³C NMR. Hydrogen chloride was eliminated preferentially from chloroethylene units occurring between two sulfonyl units. The proportion chloroethylene units: sulfonyl units in poly(sulfonyl-2-chloroethylene) decreased from ≈ 2:1 at a copolymerization temperature of 0°C to ≈ 1:1 at a temperature of ?78°C. The results show, that dehydrochlorination of copolymers prepared at low temperatures is a serious problem, especially with initiation by γ-irradiation.     

Influence of scaffold thickness and scaffold composition on bioartificial graft survival

Biological scaffolds exhibit advantageous properties for tissue engineering of small diameter vessels. The influence of their extracellular matrix (ECM) components during in vivo repopulation is unknown. We implanted different xenogenic vascular matrices in a rat model to determine the influence of scaffold-thickness and ECM composition on in vivo repopulation. Decellularized ovine jugular vein (JV, n=42), carotid artery (CA, n=42) and aorta (AO, n=42) were implanted subcutaneously in the neck of adult male rats. Animals were sacrificed 2, 4 and 8 weeks after implantation. Cell and matrix morphology of explanted scaffolds were characterized by hematoxylin-eosin and pentachrome staining. Monoclonal anti-rat-CD31 was used to identify revascularization. Quantification of cell density was done by DNA-isolation.THICKNESS OF IMPLANTED XENOGENIC SCAFFOLDS VARIED ACCORDING TO THE MATERIAL USED (AO: 3.0-3.8mm; CA: 0.7-0.88mm; JV: 0.35-0.61mm). Immunohistology revealed complete repopulation of AO, CA, and JV scaffolds with endothelial cells and myofibroblasts within 2 weeks. After 8 weeks of implantation, AO scaffolds were completely covered by an endothelial monolayer and showed signs of a central matrix degeneration. JV scaffolds were completely degenerated at this stage. In contrast, CA scaffolds showed preserved ECM with a normal myofibroblast population and endothelial cell coverage.     

Wide spread scars, hypertrophic scars, and keloids

Patients with a wide scar may complain of having a "keloid," yet have a hypertrophic or a wide spread scar. The plastic surgeon should make the appropriate clinical diagnosis, because therapy varies depending on the condition present. A wide spread scar is best treated with excision and closure. A buried dermal flap may help to prevent recurrence, which is nevertheless likely to some degree. A hypertrophic scar can be distinguished from a keloid on clinical grounds. Although both may be red, nodular, and itchy, the keloid overgrows the original wound boundary and is much more likely to recur after surgical excision. Nonsurgical treatment of hypertrophic scars and keloids is similar, using repeated intralesional injections of Kenalog 40 mg per cc and sustained pressure on the lesion when possible. Surgical treatment differs for hypertrophic scars or keloids. Scar excision and closure, and selective Z-plasty, may be used in hypertrophic scars. In keloids, aggressive surgery is usually avoided, unless the lesion has a narrow pedicle. Surgery of keloids should be accompanied by intra- and postoperative Kenalog-40 injections, and on occasion by sustained pressure. Very large keloids may be resistant to medical management, and too aggressive for surgery owing to a high likelihood of recurrence. These difficult lesions serve as the impetus for continued biochemical and tissue culture research, seeking a biochemical means of control keloids.     

Vegan Diet and Bone Health—Results from the Cross-Sectional RBVD Study

Scientific evidence suggests that a vegan diet might be associated with impaired bone health. Therefore, a cross-sectional study (n = 36 vegans, n = 36 omnivores) was used to investigate the associations of veganism with calcaneal quantitative ultrasound (QUS) measurements, along with the investigation of differences in the concentrations of nutrition- and bone-related biomarkers between vegans and omnivores. This study revealed lower levels in the QUS parameters in vegans compared to omnivores, e.g., broadband ultrasound attenuation (vegans: 111.8 ± 10.7 dB/MHz, omnivores: 118.0 ± 10.8 dB/MHz, p = 0.02). Vegans had lower levels of vitamin A, B2, lysine, zinc, selenoprotein P, n-3 fatty acids, urinary iodine, and calcium levels, while the concentrations of vitamin K1, folate, and glutamine were higher in vegans compared to omnivores. Applying a reduced rank regression, 12 out of the 28 biomarkers were identified to contribute most to bone health, i.e., lysine, urinary iodine, thyroid-stimulating hormone, selenoprotein P, vitamin A, leucine, α-klotho, n-3 fatty acids, urinary calcium/magnesium, vitamin B6, and FGF23. All QUS parameters increased across the tertiles of the pattern score. The study provides evidence of lower bone health in vegans compared to omnivores, additionally revealing a combination of nutrition-related biomarkers, which may contribute to bone health. Further studies are needed to confirm these findings.     

Improved biological properties of synthetic distearoyl phosphatidyl choline-based liposome in the conscious rat

We have previously produced and tested a liposome preparation based on hydrogenated soy lecithin (HSL-L) for the purpose of designing blood replacement in the form of liposome encapsulated hemoglobin (LEH). While these liposomes had acceptable physicochemical properties which addressed many of the desirable characteristics of "artificial blood," they produced hypotension, hemoconcentration, and thrombocytopenia when administered to rats. The following studies present improved synthetic distearoyl phosphatidylcholine-based liposomes (sDSPC-L) which were compared to the HSL-L for their biological effects in the conscious normovolemic rat (n = 6 - 11). HSL-L induced hypotension (-25 +/- 3 mmHg, P less than 0.01), tachycardia (+88 +/- 11 beats/min, P less than 0.01), decrease in cardiac index (-33 +/- 4%, P less than 0.01), and elevation of the total peripheral resistance index (+0.450 +/- 0.003 mmHg/ml/min/kg, P less than 0.01). The hematologic responses to HSL-L were: leukocytosis (+6,070 +/- 1,064/microliters, P less than 0.01), hemoconcentration (+4.0 +/- 0.1%, P less than 0.01), 0.01), and thrombocytopenia (-160 +/- 18 X 10(3)/microliters, P less than 0.01). Plasma thromboxane B2 (TXB2) was elevated to 30.4 +/- 5.6 pg/100 microliters (P less than 0.01). In contrast, the only effects induced by sDSPC-L were slight tachycardia (+37 +/- 9 beats/min, P less than 0.05) and a marginal increase in plasma TXB2 to 9.7 +/- 3.3 pg/100 microliters (P less than 0.05). All effects, except for those related to cardiac output and peripheral resistance, were transient. These data underscore the importance of pure synthetic DSPC in improving the biological effects of liposomes and suggest sDSPC-L as a promising vehicle for encapsulating hemoglobin.     

Asthma und asthmatypische Beschwerden bei Schulkindern: Vergleich von Gebieten in Deutschland und Osterreich

Conclusion

Geographical differences in morbidity of asthma and asthmalike complaints were ascertained and remained stable after adjustment for potential confounders. However, the choice of the way of presentation (relative risk versus deviation from the weighted mean of the prevalences) can provoke different suggestive effects.     

Aging trends: Indonesia

The authors discuss causes and consequences of aging trends in Indonesia. Aspects considered include median age and support ratios; life expectancy; marital status and living arrangements; health, mobility, and disability; education; and work and income.     

Which organic acids does hemofiltrate contain in the presence of acute renal failure?

It is not generally possible to measure most organic acids in the serum of critically ill patients, due to rapid metabolism and methodological problems. Only the regular measurement of lactic acid and the arterial ketone body ratio (acetoacetate/beta-hydroxybutyrate, AKBR) have been introduced in clinical practice, but these parameters can represent only a part of the disturbed metabolism. In pediatric patients, a chromatographical urine analysis has been established for detection of inborn errors of metabolism, which allows the determination of more than 50 organic acids simultaneously (gas chromatographic (GC) analysis in combination with mass spectrometry (MS)]. In continuous treatment of acute renal failure, hemofiltrate is always available, but it contains only low protein concentrations and after the filtration process, metabolism is rapidly stopped. The sieving coefficient of lactic acid is nearly one in hemofiltration. The aim of our study was to compare results of the regular and CG/MS methods in blood and hemofiltrate for lactic acid, and to find other organic acids of possible clinical importance. We investigated serum (lactic acid) and hemofiltrate of 40 critically ill patitens, similar to the urine analysis method for infants. All patients suffered from acute renal failure and were treated by continuous veno-venous hemofiltration (CVVH). The conditions of treatment were standardized (spontaneous ultrafiltration in the first hour), and the material (blood/hemofiltrate) was taken one hour after the beginning of extracorporeal circulation. Statistical methods included correlation analysis, nonparametric ANOVA with Wilcoxon scores (ranks of data), and stepwise discriminant analysis. Regular and GC/MS methods in hemofiltrate showed a good correlation for lactic acid. The best correlation with lactic acid was found for 4-hydroxy-phenyllactic acid (n=20, r=0.866), 2-hydroxy-valeric acid (n=22, r=0.7491) and 2-hydroxybutyric acid (n=32, r=0.5148). Age, sex, diagnosis, and APACHE II score play a subordinate role, but the presence of glyceric and citric acid possibly have prognostic importance [nonparimetric ANOVA with Wilcoxon scores (ranks of data)], as does the combination of 3-hydroxypropionic acid, glyceric acid, and threonic-acid-4-lacton (stepwise discriminant analysis). It can be concluded that in acute renal failure, the measurement of lactic acid and AKBR can reflect only a small part of disturbed metabolism. Hemofiltrate can be a useful medium in describing metabolic processes in critically ill patients with acute renal failure. Some inherited metabolic diseases in infants (phenylketonuria, maple syrup disease) and ketoacidosis show similar metabolic modifications.     

Abducted, hyperextended small finger deformity of nonneurologic etiology

The abduction and hyperextension deformity of the small finger is usually associated with ulnar nerve palsy. Six patients who sustained an abduction force to their small finger presented with the finger in an abducted and hyperextended position. All patients were neurologically intact and were unable to adduct or flex the finger at the metacarpophalangeal joint. Surgical findings in these patients included rupture of the radial sagittal band, collateral ligament, and junctura tendinum. Sequential division of these structures in cadaveric hands confirmed that all these tissues had to be deficient for this deformity to occur. The traumatic abducted, hyperextended small finger deformity may respond to conservative treatment, but surgery is sometimes necessary.