Non‐Isothermal Crystallization of Poly(trimethylene terephthalate) (PTT)/Clay Nanocomposites

Summary: The non‐isothermal crystallization of intercalated poly(trimethylene terephthalate) (PTT)/clay nanocomposites was investigated quantitatively by different methods. Non‐isothermal crystallization of pure PTT can be described by the Ozawa equation, but the Ozawa theory is not valid for PTT/clay nanocomposites. The addition of clay into PTT decreases the crystallization half‐time while increasing the crystallinity and crystallization rate. The PTT/modified clay nanocomposites, in turn, have a higher crystallization rate parameter, k^1/n, and a lower crystallization half‐time compared to unmodified clay/PTT composites. The crystallization activation energy, calculated from Kissinger equation, of PTT, PTT/unmodified clay, and PTT/modified clay composites are 100, 180, and 198–230 kJ · mol^?1, respectively. Similarly, the nucleating activities of the unmodified clay and modified clays are 0.73 and 0.51–0.58, respectively. Although the addition of clay increases the crystallization activation energy, the clay still acts as an effective nucleating agent and increases the crystallization rate and crystallinity of PTT. Further, the modified nanoscale clays are more effective nucleating agents than the unmodified counterparts, and the most effective nucleating concentration of nano‐clay is between 1.0–3.0 wt.‐%.

The crystallization half‐time, t_1/2, decreases as a function of cooling rate, Q, and decreases with an increase in clay concentration.     

Immune responses to Aspergillus antigen in IL‐4‐/‐ mice and the effect of eosinophil ablation

BACKGROUND: Exposure to Aspergillus fumigatus allergens results in enhanced total serum IgE and peripheral blood eosinophils in mice. The associated pulmonary inflammation and immunologic responses are comparable to those detected in human allergic bronchopulmonary aspergillosis. Allergen-induced cytokines are thought to regulate the inflammatory and immune responses in these animals. METHODS: In the present study, we exposed C57BL/6 and BALB/c mice to A. fumigatus antigen. Both wild-type and IL-4 knockout phenotypes of animals of both strains were used. Some animals were also treated with anti-IL-5 or anti-IFN-gamma. Total serum IgE, Aspergillus species IgG subclass, peripheral blood eosinophils, and lung histology were studied. RESULTS: The results demonstrate similar lung inflammation in all wild-type and IL-4-/- animals exposed to A. fumigatus antigen. Similarly, in spite of the diverse immune response produced by the anticytokine treatment, no major differences were detected among any of the animal groups studied. CONCLUSIONS: It can be concluded that A. fumigatus exposure in an immunologically unaltered host is predominantly of a Th2 type, and that depletion of the Th2 cytokine leads to a similar lung inflammation but with a characteristic Th1 response, suggesting that the pathogenesis of allergic aspergillosis is the result of multiple induction pathways.     

A clinical study assessing the tolerability and biological effects of infliximab, a TNF-alpha inhibitor, in patients with advanced cancer

BACKGROUND: Tumour necrosis factor-alpha (TNF-alpha) is an important regulator of the chronic inflammation contributing to tumour progression. Infliximab, an anti-TNF-alpha monoclonal antibody was investigated in this trial of patients with advanced cancer. The primary objectives were to determine the safety profile and biological response of infliximab in a cancer population. Clinical response was a secondary objective. PATIENTS AND METHODS: Forty-one patients received infliximab at 5 mg/kg (n = 21) or 10 mg/kg (n = 20) i.v. at 0 and 2 weeks and then every 4 weeks. Post-treatment samples were measured for changes in plasma and serum TNF-alpha, CCL2, IL-6 and C-reactive protein (CRP). RESULTS: Infliximab was well tolerated with no dose-limiting toxic effects. At both doses of infliximab, neutralisation of serum TNF-alpha was observed after 1 h while plasma CCL2, IL-6 and serum CRP were decreased 24 and 48 h following infliximab administration. Seven patients experienced disease stablisation (range 10-50+ weeks). There was no evidence of disease acceleration in any patient. CONCLUSIONS: Infliximab treatment was safe and well tolerated in patients with advanced cancer. There was evidence of biological activity with baseline TNF-alpha and CCL2 being correlated with infliximab response.     

Effect of antenatal steroid administration on the fetal biophysical profile

PURPOSE: Our objective was to determine whether antenatal steroid administration affects the biophysical profile score in fetuses. METHODS: A prospective study was conducted in 84 fetuses between 28 and 34 weeks' menstrual age at risk of preterm delivery. Two intramuscular injections of 12 mg of betamethasone were given to the mother 24 hours apart. All fetuses underwent biophysical profile testing prior to and between 24 and 48 hours after steroid administration. Biophysical profiles (including nonstress tests) were evaluated by two maternal-fetal medicine specialists blinded to the timing of steroid administration. Neonatal outcome, including Apgar score, menstrual age at delivery, admission to and length of stay in the neonatal intensive care unit, and mortality, was analyzed in all subjects. RESULTS: In 31 (37%; 95 confidence interval, 26.6-47.2%) of 84 cases, the biophysical profile score decreased at least 2 points after steroid administration. The most commonly affected variables were fetal breathing and the nonstress test. There was no significant difference in the neonatal outcome between the fetuses whose biophysical profile decreased and those whose did not. CONCLUSIONS: Biophysical profile scores were decreased in more than one third of fetuses within 48 hours of antenatal steroid administration, but neonatal outcome was not affected. Knowledge of this occurrence could avoid incorrect decision making regarding fetal well-being.     

Changing incidence of sinus infection in children

This study presents the results of a 20 year review of maxillary sinus wash-outs performed on children. The results show a decreasing incidence of purulent sinusitis over the study period. Only 17 per cent of antral wash-outs undertaken yielded pus, indicating that surgical practice has failed to adequately take account of the changing disease incidence.     

A Korean kindred with autosomal dominant nocturnal frontal lobe epilepsy and mental retardation

BACKGROUND: A Korean family had distinctive clinical and neuroimaging features and carried the same genetic mutation that was found in a previously described Japanese kindred with autosomal dominant nocturnal frontal lobe epilepsy. OBJECTIVE: To describe the first Korean family with autosomal dominant nocturnal frontal lobe epilepsy. METHODS: Members of a large family, including 9 affected individuals from 3 generations, underwent a comprehensive genetic, clinical, electroencephalographic, neuropsychological, and neuroimaging evaluation. Affected members were tested for possible mutations in transmembrane regions 1 through 3 of the neuronal nicotinic acetylcholine receptor alpha4 subunit (CHRNA4) by direct sequencing and subsequent restriction analysis. RESULTS: Seizures began in childhood, presenting as nocturnal episodes of staring, confusion, shouting, perioral movements, unintelligible speech, and hand waving. Some patients had ictal or interictal epileptiform activity in the temporal and/or frontocentral areas. Neurological examination and brain magnetic resonance imaging results showed no abnormalities, except that all patients available for testing had mild to moderate mental retardation. Fluorodeoxyglucose F 18 with positron emission tomography showed mild decreased glucose uptake in the superior and middle frontal regions, more so on the left than on the right. Patient response to carbamazepine was poor. All affected members were heterozygous for the CHRNA4 Ser252Leu mutation. CONCLUSIONS: Disorders associated with mutations in the transmembrane region 2 of CHRNA4 are genetically and phenotypically heterogeneous. Distinctive features of this kindred include (1) mental retardation in all affected members available for testing, (2) abnormal brain findings on fluorodeoxyglucose F 18 with positron emission tomography, (3) poor response to carbamazepine, and (4) full penetrance.     

Blepharospasm and hemifacial spasm

Opinion statement