Cross-linked starch microspheres: Effect of cross-linking condition on the microsphere characteristics

Cross-linked starch microspheres were prepared using different kinds of cross-linking agents. The influence of several parameters on morphology, size, swelling ratio and drug release rate from these microspheres were evaluated. These parameters included cross-linker type, concentration and the duration of cross-linking reaction. Microspheres cross-linked with glutaraldehyde had smooth surface compared with those prepared with epichlorhydrine or formaldehyde. The particle size increased with increasing the cross-linking time and increasing the drug loading. Swelling ratio of the particles was a function of cross-linker type but not the concentration or time of cross-linking. Drug release from starch microspheres was measured in phosphate buffer and also in phosphate buffer containing alpha-amylase. Results showed that microspheres cross-linked with epichlorhydrine released all their drug content in the first 30 minutes. However, cross-linking of the starch microspheres with glutaraldehyde or formaldehyde decreased drug release rate. SEM and drug release studies showed that cross-linked starch microspheres were susceptible to the enzymatic degradation under the influence of alpha-amylase. Changing the enzyme concentration from 5000 to 10,000 IU/L, increased drug release rate but higher concentration of enzyme (20,000 IU/L) caused no more acceleration.     

Long-term results of hemigastrectomy with vagotomy in the treatment of bleeding peptic ulcers

Summary and conclusion A total of 102 patients who underwent hemigastrectomy and truncal vagotomy for bleeding peptic ulcers were followed for 6–12 years. Eighty per cent of these patients had a follow-up of 8 years or more. The recurrence of hemorrhage after this operation has been 6.8%. None of these patients bled massively or required a second operation. These results are notably more favorable than those previously reported. The relatively low mortality and the high rate of effectiveness of hemigastrectomy with vagotomy and gastrojejunostomy in the present series demonstrate the superiority of this procedure as the surgical treatment of choice for the control of bleeding from peptic ulcers.     

Pet exposure and the symptoms of asthma, allergic rhinitis and eczema in 6-7 years old children

Allergic diseases are frequent in children and their prevalence and severity differ in the different regions of the world. The association between pet ownership in childhood and subsequent asthma and sensitization is very controversial.In our survey conducted with standardized method (International Study of Asthma and Allergies in Childhood), 3200 children 6-7 years old were questioned regarding asthma, allergic rhinitis and eczema. The prevalence of Attacks and shortness of breath with wheezing during last 12 months in the children who had exposure to pets in the first year of life was 34.3% 'that was less than children who had not exposure (OR=3.06, 95% confidence interval [CI] 1.14-8.21, P=0.021). Also during the past 12 months the prevalence of night dry coughs, allergic rhinitis symptoms and eczema symptoms in those who had pet exposure in the first year of their life was lower than the children did not have it. However there was no significant difference in some other symptoms of asthma in two groups.Our findings suggest that pet exposure in the first year of life can have a protective effect on asthma, allergic rhinitis and eczema.     

IL-10, TNF-α and IFN-γ levels in serum and stomach mucosa of Helicobacter pylori-infected patients

H. pylori is a human pathogen that colonizes the epithelium of the stomach. The host immune response may influence the disease process, where cytokines play important roles in the development of disease. In this study, the concentrations of selected cytokines in the gastric antrum and stomach body mucosa and also in the serum were evaluated. Eighty patients according to their rapid urease test were divided into two groups: H. pylori positive (n=39) and H. pylori-negative (n=41). The concentrations of cytokines in biopsies and serum were determined by ELISA method. The mean TNF-α and IFN-γ levels in the infected group were significantly higher than that of uninfected patients. In contrast, IL-10 level in most patients was undetectable. The mean antral of stomach TNF-α and IFN-γ levels were significantly higher than that of the stomach body. IFN-γ serum level showed positive correlation with antrum and stomach body levels, whereas no correlation was found in TNF-α in different samples. Higher levels of TNF-α and IFN-γ in antral indicate that the colonization of bacteria in the antrum may be higher than stomach body (culture results from two sites support this statement). Increased serum level of IFN-γ indicates the activation of circulating-T cells against infection. Induced H. pylori-related TNF-α is concentrated is gastric mucosa and this pathogen does not cause any significant change in the serum level of this cytokine. Therefore H. pylori by inducing certain inflammatory cytokines but not IL-10 may contribute the process of disease development.     

Cloning and Expression of the Allergen Cro s 2 Profilin from Saffron (Crocus sativus)

BackgroundProfilin is a panallergen that is recognized by IgE in allergic patients. Allergy to saffron (Crocus sativus) pollen has been described in people exposed to its pollen. Saffron contains a profilin that may cause allergic reactions in atopic subjects. The aim of this study was to describe the cloning, expression and purification of saffron profilin from pollen.MethodsCloning of saffron profilin was performed by polymerase chain reaction using specific primers from saffron pollen RNA. Expression was carried out in Escherichia coli BL21 (DE3) using a vector pET-102- TOPO. A recombinant fusion protein was expressed and the recombinant profilin was purified by metal precipitation. Immunological characterization was performed by immunoblotting experiments.ResultsThe 34 kDa- recombinant saffron profilin, Cro s 2, as a fusion protein was purified. Immunoblotting tested with the sera of allergic patients showed a specific reaction with the recombinant Cro s 2 band.ConclusionsThe sequence of Cro s 2 showed a high degree of identity and similarity to other plant profilins and the recombinant saffron profilin, Cro s 2, may be used for target-specific diagnosis and structural analyses and investigation of cross reactivity of Cro s 2 with other plant profilins.     

A cytotoxic hydroperoxy sterol from the brown alga,Nizamuddinia zanardinii

Background

The marine environment is a unique source of bioactive natural products, of which Nizamuddinia zanardinii is an important brown algae distributed in Oman Sea. Literature revealed that there is no report on phytochemistry and pharmacology of this valuable algae.

Methods

Bioguided fractionation of the methanolic extract of Nizamuddinia zanardinii, collected from Oman Sea, led to the isolation of a hydroperoxy sterol. Its structure was determined by analysis of the spectroscopic data as 24-hydroperoxy-24-vinyl cholesterol (HVC). In vitro cytotoxic activity of this compound was evaluated against HT29, MCF7, A549, HepG2 and MDBK cell lines.

Results

Although 24(R)-hydroproxy-24-vinylcholesterol has been previously reported from Sargassum and Padina species, it is the first report on the presence of this compound from N. zanardinii. This compound exhibited cytotoxicity in all cell lines (IC₅₀, 3.62, 9.09, 17.96, 32.31 and 37.31 μg/mL respectively). HVC was also evaluated for apoptotic activity and demonstrated positive results in terminal deoxynucleotidyl transferase dUTP Nick End labeling (TUNEL) assay suggesting it a candidate for further apoptotic studies.

Conclusions

Nizamuddinia zanardinii, a remarkable brown algae of Oman Sea, is a good source of hydroproxy sterols with promising cytotoxic on various cell lines particularly human colon adenocarcinoma.     

The Results of Brown Syndrome Surgery with Superior Oblique Split Tendon Lengthening

Purpose: To report the surgical outcome of superior oblique tendon split lengthening for management of patients with severe type of congenital Brown syndrome. Brown syndrome is characterized by hypotropia in primary position and limitation of elevation in adduction more than ?4.

Materials and methods: Fourteen consecutive patients with severe congenital Brown syndrome underwent superior oblique split lengthening surgery (10?mm). The amount of hypotropia in primary gaze and the degree of elevation in adduction were compared before and after the surgery. Any surgical complications were also recorded.

Results: Surgery was performed on 15 eyes in 11 female and 3 male subjects. Mean postoperative follow-up time was 12.93?±?1.79 months (ranging from 10 to 16 months). Average hypotropia in primary gaze improved from 16.2?±?5.5 prism diopters (range: 10–25 prism diopters) preoperatively to 5.9?±?4.0 prism diopters (range: 0–18 prism diopters) postoperatively recorded at final follow-up examination (p?p?Conclusion: Superior oblique split lengthening has a significant effect on reducing primary gaze hypotropia and improving elevation in adduction. This technique should be considered for the treatment of patients with severe congenital Brown syndrome.     

Improved MR-based characterization of engineered cartilage using multiexponential T2 relaxation and multivariate analysis

Noninvasive monitoring of tissue quality would be of substantial use in the development of cartilage tissue engineering strategies. Conventional MR parameters provide noninvasive measures of biophysical tissue properties and are sensitive to changes in matrix development, but do not clearly distinguish between groups with different levels of matrix development. Furthermore, MR outcomes are nonspecific, with particular changes in matrix components resulting in changes in multiple MR parameters. To address these limitations, we present two new approaches for the evaluation of tissue engineered constructs using MR, and apply them to immature and mature engineered cartilage after 1 and 5 weeks of development, respectively. First, we applied multiexponential T(2) analysis for the quantification of matrix macromolecule-associated water compartments. Second, we applied multivariate support vector machine analysis using multiple MR parameters to improve detection of degree of matrix development. Monoexponential T(2) values decreased with maturation, but without further specificity. Much more specific information was provided by multiexponential analysis. The T(2) distribution in both immature and mature constructs was qualitatively comparable to that of native cartilage. The analysis showed that proteoglycan-bound water increased significantly during maturation, from a fraction of 0.05 ± 0.01 to 0.07 ± 0.01. Classification of samples based on individual MR parameters, T(1), T(2), k(m) or apparent diffusion coefficient, showed that the best classifiers were T(1) and k(m), with classification accuracies of 85% and 84%, respectively. Support vector machine analysis improved the accuracy to 98% using the combination (k(m), apparent diffusion coefficient). These approaches were validated using biochemical and Fourier transform infrared imaging spectroscopic analyses, which showed increased proteoglycan and collagen with maturation. In summary, multiexponential T(2) and multivariate support vector machine analyses provide improved sensitivity to changes in matrix development and specificity to matrix composition in tissue engineered cartilage. These approaches show substantial potential for the evaluation of engineered cartilage tissue and for extension to other tissue engineering constructs.