Surgery for diverticular disease results in a higher hernia rate compared to colorectal cancer: a population-based study from Ontario, Canada.

BACKGROUND: Incisional hernias are a well described complication of abdominal surgery. Previous studies identified malignancy and diverticular disease as risk factors. We compared incisional hernia rates between colon resection for colorectal cancer (CRC) and diverticular disease (DD). STUDY DESIGN: We performed a retrospective, population-based, matched cohort study. Provincial databases were linked through the Institute for Clinical Evaluative Sciences. These databases include all patients registered under the universal Ontario Health Insurance Plan. Patients aged 18-105 undergoing open colon resection, without ostomy formation between April 1, 2002 and March 31, 2009, were included. We excluded those with previous surgery, hernia, obstruction, and perforation. The primary outcomes were surgery for hernia repair, or diagnosis of hernia in clinic. RESULTS: We identified 4660 cases of DD. These were matched 2:1 by age and gender to 8933 patients with CRC for a total of 13,593. At 5 years, incisional hernias occurred in 8.3% of patients in the CRC cohort, versus 13.1% of those undergoing surgery for DD. After adjusting for important confounders (comorbidity score, wound infection, age, diabetes, prednisone and chemotherapy), hernias were still more likely in patients with DD [HR 1.58, 95% Confidence Interval (CI) 1.43-1.76, P < 0.001]. The only significant covariate was wound infection (HR 1.63, 95% CI 1.43-1.87, P < 0.001). CONCLUSION: Our study found that incisional hernias occur more commonly in patients with DD than CRC.

Drying efficiency and particle movement in coating--impact on particle agglomeration and yield.

The purpose of this study was to determine the influences of drying efficiency and particle movement on the degree of agglomeration and yield of pellets coated under different conditions. Thermodynamic conditions were varied using different inlet air temperatures and airflow rates, fluid dynamics were varied using different airflow patterns and air velocities, and two sizes of pellets were coated at different airflow rates and partition gaps. Agglomeration was minimized when all the moisture introduced into the system was removed by the drying air. Excessively dry conditions led to increased loss of yield due to spray-drying effect and attrition. Fluid dynamics were still important even with adequate drying, as the degree of agglomeration was relatively higher in the non-swirling airflow of Wurster coating than in the swirling airflow of precision coating. Increasing air velocities increased pellet velocities, resulting in lower degrees of agglomeration. Hence, agglomeration due to fluid dynamics was attributed to differences in pellet velocities, pellet proximity and pellet trajectories within the partition column. Smaller pellets agglomerated primarily from inadequate drying and not due to inadequate opportunities for particle movement. Larger pellets were more affected by the partition gap due to restriction of their movement through the partition gap. Hence, both thermodynamics and fluid dynamics were found to be important in minimizing agglomeration and ensuring quality coated products.

Use of swirling airflow to enhance coating performance of bottom spray fluid bed coaters.

As there is strong interest in coating increasingly smaller particles or pellets for use in compacted dosage forms, there is a need for better small particle coating systems. This study explored the use of swirling airflow to enhance the performance of the bottom spray coating system. Firstly, pellet coating in the non-swirling airflow of conventional Wurster coating was compared with that of swirling airflow in precision coating under standardized conditions. Secondly, precision coating was studied in greater details at different airflow rates (60-100m(3)/h) and partition gaps (6-22mm). Precision coating was found to have higher Reynolds numbers (Re) than Wurster coating, indicating higher turbulence. It produced coated pellets of better properties than Wurster coating, having less agglomeration and gross surface defects, more uniform coats, increased flow and tapped density, and slower drug release. Higher surface roughness did not affect the yield. In precision coating, increasing airflow rates decreased the degree of agglomeration but had minimal effect on pellet quality attributes (colour intensity, colour uniformity and surface roughness) and yields. Increasing partition gaps increased the degree of agglomeration proportionally, but this effect was small. However, greater changes in yield, surface roughness, colour intensity and colour uniformity were detected. This study showed that precision coating, while having a higher drying ability, was able to maintain the same yield and produce coated pellets with superior quality compared to Wurster coating. In precision coating, airflow rate had greater influence on the drying of pellets while partition gap had greater influence on pellet quality attributes.

Ultrasonication of chitosan and chitosan nanoparticles.

The objective of this study was to evaluate the effects of ultrasonication on chitosan molecules and nanoparticles. Molecular weight (M(v)) of chitosan HCl (M(v) 146 kDa and degree of deacetylation (DD) 96%) decreased linearly with increasing duration and amplitude of ultrasonication. DD and FTIR absorption were unaffected. X-ray diffraction (XRD) analysis suggested greater chain alignment in the ultrasonicated chitosan samples. Chitosan nanoparticles had mean diameter of 382 nm, polydispersity of 0.53 and zeta potential of 47 mV. Ultrasonication administered at increasing duration or amplitude decreased the mean diameter and polydispersity of the nanoparticles. Zeta potential and FTIR absorbance were unaffected, while XRD suggested a greater disarray of chain alignment in the nanoparticle matrix. Under the transmission electron microscope (TEM), freshly prepared nanoparticles were dense spherical structures which became fragmented after ultrasonication for 10 min at amplitude of 80. Untreated nanoparticle formulation turned turbid upon storage for 3 weeks at ambient conditions due to substantial swelling of the nanoparticles. Ultrasonicated nanoparticle formulation remained clear on storage. Although the particles had also swelled, they were no longer spherical, assuming instead an irregular shape with branching arms. In conclusion, high-intensity ultrasonication induced considerable damage on the chitosan nanoparticles which could affect their function as drug carriers.

The treatment of multiple intracranial tuberculous abscesses: a case report.

A Chinese female aged 2 years 8 months with tuberculous meningitis developed hydrocephalus requiring insertion of a ventriculoperitoneal shunt. After adequate anti-tuberculosis chemotherapy for 14 weeks, multiple intracranial tuberculous abscesses developed. The lesions increased in size and number accompanied by clinical deterioration. Repeated drainage operations were performed in view of the increased intracranial pressure. The child made a remarkable recovery after an initial stormy course.