Incorporation of sol-gel bioactive glass into PLGA improves mechanical properties and bioactivity of composite scaffolds and results in their osteoinductive properties.

In this study, 3D porous bioactive composite scaffolds were produced and evaluated for their physico-chemical and biological properties. Polymer poly-L-lactide-co-glycolide (PLGA) matrix scaffolds were modified with sol-gel-derived bioactive glasses (SBGs) of CaO-SiO2-P2O5 systems. We hypothesized that SBG incorporation into PLGA matrix would improve the chemical and biological activity of composite materials as well as their mechanical properties. We applied two bioactive glasses, designated as S2 or A2, differing in the content of SiO2 and CaO (i.e. 80 mol% SiO2, 16 mol% CaO for S2 and 40 mol% SiO2, 52 mol% CaO for A2). The composites were characterized for their porosity, bioactivity, microstructure and mechanical properties. The osteoinductive properties of these composites were evaluated in human bone marrow stromal cell (hBMSC) cultures grown in either standard growth medium or treated with recombinant human bone morphogenetic protein-2 (rhBMP-2) or dexamethasone (Dex). After incubation in simulated body fluid, calcium phosphate precipitates formed inside the pores of both A2-PLGA and S2-PLGA scaffolds. The compressive strength of the latter was increased slightly compared to PLGA. Both composites promoted superior hBMSC attachment to the material surface and stimulated the expression of several osteogenic markers in hBMSC compared to cells grown on unmodified PLGA. There were also marked differences in the response of hBMSC to composite scaffolds, depending on chemical compositions of the scaffolds and culture treatments. Compared to silica-rich S2-PLGA, hBMSC grown on calcium-rich A2-PLGA were overall less responsive to rhBMP-2 or Dex and the osteoinductive properties of these A2-PLGA scaffolds seemed partially dependent on their ability to induce BMP signaling in untreated hBMSC. Thus, beyond the ability of currently studied composites to enhance hBMSC osteogenesis, it may become possible to modulate the osteogenic response of hBMSC, depending on the chemistry of SBGs incorporated into polymer matrix.

Nonattendance at outpatient endoscopy.

BACKGROUND AND STUDY AIMS: Nonattendance at outpatient endoscopy leads to inefficiency and delay in diagnosis. We aimed to identify factors associated with failure to attend outpatient gastroscopy and colonoscopy. PATIENTS AND METHODS: We carried out a retrospective audit of nonattendance at outpatient endoscopy over a 12-month period at our tertiary hospital endoscopy unit. Attending patients on the same endoscopy list were used as controls. Patient charts and referral letters were reviewed. The information collected included referral source, time between referral and procedure, indication and type of procedure, reason for nonattendance and history of previous endoscopy. Following the audit a trial of telephone reminders was implemented over a 3-month period. RESULTS: From 2157 outpatient procedures that were scheduled, 263 nonattendees (12.2 %) were identified with 261 controls. Of the nonattendees, 109 (41 %) did not attend for colonoscopy, 121 (46 %) did not attend for gastroscopy and 33 (13 %) failed to turn up for combined procedures. Monday was the most common day of the week for nonattendance (40 % of nonattenders). Nonattendees were younger (46 +/- 14 vs. 55 +/- 16, P < 0.001), less likely to be referred from a gastroenterologist ( P < 0.001) or private practice ( P = 0.02) and more likely to be referred from the emergency department ( P = 0.007). Subsequent to this, a 3-month period of telephone reminder reduced nonattendance rates from 12.2 % to 9 % ( P = 0.03). CONCLUSIONS: Younger patients scheduled for outpatient endoscopy on Mondays who are not referred by a gastroenterologist or private physician are more likely not to attend. These patients should be targeted for interventions designed to increase attendance. Telephone reminders have a modest effect on reducing nonattendance rates.

Partial CFTR genotyping and characterisation of cystic fibrosis patients with myocardial fibrosis and necrosis.

Myocardial necrosis and fibrosis is a rare complication of cystic fibrosis (CF) causing sudden and unexpected death in infancy due to cardiac arrest. Characteristic morphological lesions are recognisable postmortem. The 18 CF patients with this complication had varied clinical features including mild pulmonary involvement, early onset severe pancreatic insufficiency, and profound electrocardiogram (ECG) changes. In this group of patients, 5 were deltaF508 homozygotes, 1 was deltaF508/ N1303K and 1 was a deltaF508/M compound heterozygote. A pair of affected siblings (deltaF508 homozygotes) were fully concordant for myocardial involvement and for the general course of the disease. The co-existence of a genetic predisposition to myocardial lesions resulting most probably from severe cystic fibrosis transmembrane (CFTR) genotypes (such as deltaF508/deltaF508, deltaF508/N1303K) and deficiency of certain trophic factors necessary for metabolism of the myocardium, are postulated to cause myocardial complications in CF leading to circulatory failure and early death.

The Kartagener syndrome--an electron microscopic studies of biopsied mucosa.

We studied 43 tissue samples taken from patients (16 male and 27 women) with clinical diagnosis of Kartagener's syndrome. The specimens were fixed and prepared for transmission electron microscopy. After preliminary light microscopic examination 23 cases were qualified for ultrastructural studies. We found abnormal number of cilia on the bronchial mucosa cells. The ciliary structure was abnormal. In several cases we observed lack of inner and/or outer dynein arms, abnormal location of central microtubules, and abnormal number of microtubular doublets. Other findings were as follows: replacement of ciliated cells by goblet ones, mucosal edema and inflammatory infiltrate.

[Broncho-pulmonary complications due to aspiration of foreign bodies by children]. / Powiklania oskrzelowo-plucne w wyniku aspiracji cial obcych u dzieci.

The paper describes 239 children with bronchopulmonary disease due to foreign body (f.b.) aspiration treated in our center during between 1980-1992. Twenty-eight percent of the cases had been referred to hospital without any suspicion of f.b. aspiration. Almost half of the children (49.7%) were below the age of 2 years. Boys were affected more often (61.5%) than girls. In 61.1% the cases the f.b. had been aspirated into the right bronchial tree. Pieces of nuts were the most common f.b. - 35.1%. The most common chest X-ray symptoms were disturbances of bronchial patency (74.1%). Non-metalic, but potential shadowing f.b. like bones and teeth gave the clear signs only in 17.6% of the cases. After f.b. aspiration chronic irreversible lesions such as bronchiectasis and lung fibrosis were observed in 18.8% of the children. The prevalence of bronchiectasis was proportional to the duration of deposition. If the f.b. had been removed within the first month after aspiration we observed no complications. After aspiration of ears of grain, bronchiectasis was present in 80% of cases. Aspiration of f.b. into the left bronchial tree very often caused ventilation disturbations. Such cases were diagnosed and treated earlier than cases of right side f.b. aspirations. As a consequence bronchiectasis in the left lung was observed 2.7 less frequently.

Genetically determined sparteine oxidation and sulfadimidine acetylation polymorphism in patients with non-occupational urinary bladder cancer.

The results of our study revealed a predominance of the percentage of extensive metabolizers (EM) of sparteine (94.8%) among 58 patients with non-occupational urinary bladder cancer in comparison with the percentage of extensive metabolizers (91.2%) in healthy persons; the difference being not statistically significant. However, among ultrarapid (EM) oxidators with the metabolic ratio (MR) < 0.5 the difference in the MR frequency distribution between 15 patients with bladder cancer (25.9%) and 18 healthy persons (11.25%) was statistically significant. Therefore, our studies provide some evidence of a possible relationship between the EM sparteine oxidation phenotype and the susceptibility to non-occupational bladder cancer. Not statistically significant slight prevalence of the percentage of slow acetylators (SA) (53.1%) among 32 urinary bladder cancer patients in comparison with the percentage of SA (49%) among 45 healthy persons may confirm the conclusion that a slow acetylator phenotype is not associated with the increased risk of the development of non-occupational urinary bladder cancer.

[Placental lactogen level and activity of oxytocinase, beta-glucuronidase and thermostable alkaline phosphatase isoenzyme in blood serum of women with ectopic pregnancy]. / Poziom laktogenu lozyskowego oraz aktywnosc oksytocynazy, beta-glukuronidazy i termostabilnego izoenzymu fosfatazy alkalicznej w surowicy krwi kobiet z ciaza ektopowa.

The lack of literature data dealing with placental lactogen concentration as well as with the other biochemical parameters in blood serum in women with ectopic pregnancy was the reason we turned to that problem. In eight patients with ectopic pregnancy there was determined placental lactogen level and oxytocinase activity as well as the activity of beta-glucuronidase and thermostable alkali phosphatase isoenzyme in blood serum. The results obtained were compared to the concentration of those parameters in blood serum in women with ectopic pregnancy and to those of not pregnant women. It was stated that in women with ectopic pregnancy there was produced placental lactogen and its concentration in blood serum was lower (about 30 percent) than that in women with ectopic pregnancy. Similarly, mean value of oxytocinase activity in women with ectopic pregnancy was twice lower in comparison to that of ectopic pregnancy, while beta-glucuronidase activity was twice higher when compared to that of ectopic pregnancy values. Placental alkali phosphatase isoenzyme activity was similar in both groups of pregnant women.