Towards a methodology for the effective surface modification of porous polymer scaffolds

A novel low-pressure radio-frequency plasma treatment protocol was developed to achieve the effective through-thickness surface modification of large porous poly (d,l-lactide) (PDLLA) polymer scaffolds using air or water: ammonia plasma treatments. Polymer films were modified as controls. Scanning electron micrographs and maximum bubble point measurements demonstrated that the PDLLA foams have the high porosity, void fraction and interconnected pores required for use as tissue engineering scaffolds. The polymer surface of the virgin polymer does contain acidic functional groups but is hydrophobic.

Following exposure to air or water: ammonia plasma, an increased number of polar functional groups and improved wetting behaviour, i.e. hydrophilicity, of wet surfaces was detected. The number of polar surface functional groups increased (hence the decrease in water contact angles) with increasing exposure time to plasma. The change in surface composition and wettablility of wet polymer constructs was characterised by zeta potential and contact angle measurements. The hydrophobic recovery of the treated PDLLA polymer surfaces was also studied. Storage of the treated polymer constructs in ambient air caused an appreciable hydrophobic recovery, whereas in water only partial hydrophobic recovery occurred. However, in both cases the initial surface characteristics decay as function of time.     

Skeletal recovery after weaning does not require PTHrP

Mice lose 20% to 25% of trabecular bone mineral content (BMC) during lactation and restore it after weaning through unknown mechanisms. We found that tibial Pthrp mRNA expression was upregulated fivefold by 7 days after weaning versus end of lactation in wild‐type (WT) mice. To determine whether parathyroid hormone–related protein (PTHrP) stimulates bone formation after weaning, we studied a conditional knockout in which PTHrP is deleted from preosteoblasts and osteoblasts by collagen I promoter–driven Cre (Cre^ColI). These mice are osteopenic as adults but have normal serum calcium, calcitriol, and parathyroid hormone (PTH). Pairs of Pthrp^flox/flox;Cre^ColI (null) and WT;Cre^ColI (WT) females were mated and studied through pregnancy, lactation, and 3 weeks of postweaning recovery. By end of lactation, both genotypes lost lumbar spine BMC: WT declined by 20.6% ± 3.3%, and null decreased by 22.5% ± 3.5% (p < .0001 versus baseline; p = NS between genotypes). During postweaning recovery, both restored BMC to baseline: WT to –3.6% ± 3.7% and null to 0.3% ± 3.7% (p = NS versus baseline or between genotypes). Similar loss and full recovery of BMC were seen at the whole body and hind limb. Histomorphometry confirmed that nulls had lower bone mass at baseline and that this was equal to the value achieved after weaning. Osteocalcin, propeptide of type 1 collagen (P1NP), and deoxypyridinoline increased equally during recovery in WT and null mice; PTH decreased and calcitriol increased equally; serum calcium was unchanged. Urine calcium increased during recovery but remained no different between genotypes. Although osteoblast‐derived PTHrP is required to maintain adult bone mass and Pthrp mRNA upregulates in bone after weaning, it is not required for recovery of bone mass after lactation. The factors that stimulate postweaning bone formation remain unknown. © 2011 American Society for Bone and Mineral Research.     

The Association Between Gastric Endoscopic Findings and Histologic Premalignant Lesions in the Iranian Rural Population

Atrophic gastritis, intestinal metaplasia, and gastric dysplasia are histologic premalignant lesions (PMLs). Correlation between the gastric endoscopic findings and histologic PMLs is not clear. This study was designed to determine the possible association of endoscopic findings and histologic PMLs.Over 28 months gastric endoscopic findings of consecutive rural patients with dyspepsia were categorized into 3 groups: 1—normal, 2—ulcerative with or without concurrent abnormality, 3—abnormal non-ulcerative. Biopsies of antrum and body were taken from all included patients and examined for the presence of histologic PMLs. Any mucosal abnormality was also biopsied.From 7340 evaluated patients, an overall of 1973 patients were included. 55.7% of patients were in group 1; 3.8% in group 2 and 40.5% in group 3. A within sex analysis showed that the majority of male patients were in PMLs subgroup (P < 0.001) likewise in groups 2 and 3 (P < 0.001). The prevalence of histologic PMLs in groups 2 and 3 was significantly higher than group 1 (P < 0:001) but the difference was not significant between groups 2 and 3 (P = 0.484). Mean (±SD) age of patient with PMLs was 50.25 ± 17.71 whereas in patients without PMLs was 41.16 ± 16.48 (P < 0.001).This study has showed that abnormal gastric endoscopic findings, male sex and increased age can be considered as risk factors of the formation of histologic PMLs. Until further investigations we propose that any abnormality on gastric mucosa (ulcerative or non-ulcerative) could be biopsied for the evaluation of probable histologic PMLs especially in old men.     

Rapid screening for bacteriuria in pregnancy

Summary We evaluated a bioluminescence assay as a screening test for the detection of bacteriuria in pregnancy. A total of 1,000 urine specimens from a randomly selected group of pregnant women undergoing prenatal surveillance was investigated. Sequential dilution of urine specimens on CLED agar plates served as a reference method. Set against the reference group, bioluminescence screening scored a 93% sensitivity, a 78% specificity and a 99% predictive accuracy for negative results. All urine specimens were also analysed chemically for the presence of nitrite and leucocyte esterase by dip sticks. Dip sticks proved to be insufficient because of poor sensitivities of 54% and 59%, respectively. The bioluminescence assay is an effective, time- as well as labor-saving but questionably cost-effective method for the detection of bacteriuria in pregnancy.

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Rascher Nachweis der Bakteriurie bei Schwangeren

Zusammenfassung In der vorliegenden Studie prüften wir die klinische Wertigkeit eines Biolumineszenz-Verfahrens zum Nachweis der Bakteriurie bei Schwangeren. Insgesamt wurden 1000 Routine-Harnproben von Schwangeren untersucht. Als Referenzmethode diente die sequentielle Verdünnung der Harnproben und Ausstreichen auf CLED-Agarplatten. Eine signifikante Bakteriurie konnte mit der Biolumineszenz-Methode mit einer Sensitivität von 93% und einer Spezifität von 78% erkannt werden. Die Voraussagewahrscheinlichkeit für negative Resultate war 99%. Gleichzeitig untersuchten wir alle Harnproben auf Vorhandensein von Nitrit und Leukozyten-Esterase mittels Teststreifen. Die Sensitivitäten lagen nur bei 54% bzw. 59%. Mit Hilfe der Biolumineszenz-Methode kann eine signifikante Bakteriurie bei Schwangeren rasch, verläßlich, aber nur bei relevanter Probenanzahl auch kostengünstig nachgewiesen werden.

     

Atopy patch test reactions to Malassezia allergens differentiate subgroups of atopic dermatitis patients

BACKGROUND: The yeast Malassezia is considered to be one of the factors that can contribute to atopic dermatitis (AD). OBJECTIVES: To investigate the reactivity to Malassezia allergens, measured as specific serum IgE, positive skin prick test and positive atopy patch test (APT), in adult patients with AD. METHODS: In total, 132 adult patients with AD, 14 with seborrhoeic dermatitis (SD) and 33 healthy controls were investigated for their reactions to M. sympodialis extract and three recombinant Malassezia allergens (rMal s 1, rMal s 5 and rMal s 6). RESULTS: Sixty-seven per cent of the AD patients, but only one of the SD patients and none of the healthy controls, showed a positive reaction to at least one of the Malassezia allergens (extract and/or recombinant allergens) in at least one of the tests. The levels of M. sympodialis-specific IgE in serum correlated with the total serum IgE levels. Elevated serum levels of M. sympodialis-specific IgE were found in 55% and positive APT reactions in 41% of the AD patients with head and neck dermatitis. A relatively high proportion of patients without head and neck dermatitis and patients with low total serum IgE levels had a positive APT for M. sympodialis, despite lower proportions of individuals with M. sympodialis-specific IgE among these groups of patients. CONCLUSIONS: These results support that Malassezia can play a role in eliciting and maintaining eczema in patients with AD. The addition of an APT to the test battery used in this study reveals a previously overlooked impact of Malassezia hypersensitivity in certain subgroups of AD patients.     

The efficacy of nicotinamide gel 4% as an adjuvant therapy in the treatment of cutaneous erosions of pemphigus vulgaris

The high rate of morbidity and mortality resulting from long‐term use of corticosteroids in pemphigus vulgaris (PV) warrants discovery of a new treatment strategy. Based on the pathophysiology of PV, nicotinamide can block the process of blister formation through its anti‐inflammatory properties. This study was conducted to evaluate the clinical effectiveness of nicotinamide gel in the treatment of skin lesions of PV. In a double‐blind, placebo‐controlled study, eight PV patients with a total of 60 skin lesions were treated by either nicotinamide or placebo gel. After 30 days of treatment, epithelialization index of the two groups was compared. The mean of the epithelialization index in skin lesions that received nicotinamide was significantly higher than that of the placebo group (26 vs. –5.8, p < 0.001). Our results were suggestive that nicotinamide gel can effectively be used as an adjunctive treatment for PV lesions.