Magnetoencephalographic study of event‐related fields and cortical oscillatory changes during cutaneous warmth processing

Thermoreception is an important cutaneous sense, which plays a role in the maintenance of our body temperature and in the detection of potential noxious heat stimulation. In this study, we investigated event‐related fields (ERFs) and neural oscillatory activities, which were modulated by warmth stimulation. We developed a warmth stimulator that could elicit a warmth sensation, without pain or tactile sensation, by using a deep‐penetrating 980‐nm diode laser. The index finger of each participant (n = 24) was irradiated with the laser warmth stimulus, and the cortical responses were measured using magnetoencephalography (MEG). The ERFs and oscillatory responses had late latencies (～1.3 s and 1.0–1.5 s for ERFs and oscillatory responses, respectively), which could be explained by a slow conduction velocity of warmth‐specific C‐fibers. Cortical sources of warmth‐related ERFs were seen in the bilateral primary and secondary somatosensory cortices (SI and SII), posterior part of the anterior cingulate cortex (pACC), ipsilateral primary motor, and premotor cortex. Thus, we suggested that SI, SII, and pACC play a role in processing the warmth sensation. Time–frequency analysis demonstrated the suppression of the alpha (8–13 Hz) and beta (18–23 Hz) band power in the bilateral sensorimotor cortex. We proposed that the suppressions in alpha and beta band power are involved in the automatic response to the input of warmth stimulation and sensorimotor interactions. The delta band power (1–4 Hz) increased in the frontal, temporal, and cingulate cortices. The power changes in delta band might be related with the attentional processes during the warmth stimulation.     

Localised necrosis of scrotum (Fournier's gangrene) in a spinal cord injury patient – a case report

Background  

Men with spinal cord injury (SCI) appear to have a greater incidence of bacterial colonisation of genital skin as compared to neurologically normal controls. We report a male patient with paraplegia who developed rapidly progressive infection of scrotal skin, which resulted in localised necrosis of scrotum (Fournier's gangrene).     

A study of cytokeratin 20 immunostaining in the urothelium of neuropathic bladder of patients with spinal cord injury

Background  

Normal urothelium is characterised by terminally differentiated superficial cells, which express cytokeratin 20 in the cytoplasm. In contrast, cultured human stratified urothelium, which does not undergo complete terminal differentiation of its superficial cells, does not express cytokeratin 20. If spinal cord injury (SCI) affects urothelial differentiation or induces squamous or other metaplastic change undetected by histological analysis, the superficial urothelial cells of the neuropathic bladder might be expected to show absence of immunostaining for cytokeratin 20.     

Development of agglomerated directly compressible diluent consisting of brittle and ductile materials

The objective of this investigation was to develop a novel multifunctional coprocessed adjuvant consisting of three known diluents that show different consolidation mechanisms. The method of wet granulation was adopted for the preparation of coprocessed product. Microcrystalline cellulose (MCC) and colloidal silicon dioxide (X1), lactose monohydrate (X2), and dibasic calcium phosphate dihydrate (X3, DCP) were used as independent variables in a simplex lattice design. Croscarmellose sodium was used at 4% level intragranularly in all the batches. The granules (44/120 #) were characterized for angle of repose, bulk density, tapped density, and Carr's index. The tablets of coprocessed adjuvants were characterized for crushing strength, friability, and disintegration time. Multiple linear regression was adopted for evolving refined mathematical models. A checkpoint batch was prepared and evaluated for particle size distribution, moisture uptake, and dilution potential by using nimesulide as a model drug. Microcrystalline cellulose shows poor flowability due to irregular shape and interlocking. Moreover, it loses a part of its compactibility on wet granulation. To attend these problems, a physical blend of 97% microcrystalline cellulose and 3% colloidal silicon dioxide M5 was prepared and used. The blend of MCC and colloidal silicon dioxide showed better flow than that of the original MCC. Hence, it may be easier to mix with lactose and dibasic calcium phosphate. The loss in compactibility of microcrystalline cellulose on wet granulation was also reduced due to presence of colloidal silicon dioxide. As expected, all the batches exhibited acceptable angle of repose (<35 degrees) and quick disintegration (<1 min). Full and refined models for Carr's index and crushing strength were evaluated. Based on the results of grid analysis, a checkpoint (50% MCC, 40% lactose, and 10% DCP) that satisfies both the conditions of Carr's index and crushing strength was selected. The adjuvants absorb very little moisture in the moisture uptake study. The results of dilution potential study reveal that up to 30% nimesulide, a poorly compressible drug, can be incorporated in the coprocessed product. In vitro drug dissolution from capsules containing pure drug powder and compressed tablets was comparable (f2 = 79). The results reveal that the desired product characters can be obtained by varying the quantity of MCC (a ductile material that undergoes plastic deformation), lactose (brittle material with low-fragmentation propensity), and DCP (brittle material with high-fragmentation propensity).     

Design of a potential colonic drug delivery system of mesalamine

The aim of the present investigation was to develop a site-specific colonic drug delivery system, built on the principles of the combination of pH and time sensitivity. Press-coated mesalamine tablets with a coat of HPMC E-15 were over-coated with Eudragit S100. The in vitro drug release study was conducted using sequential dissolution technique at pH 1.2, 6.0, 7.2 and 6.4 mimicking different regions of gastrointestinal tract. The optimized batch (F2) showed less than 6% of drug release before reaching colonic pH 6.4 and complete drug release was obtained thereafter within 2 hr. A short-term dissolution stability study demonstrated statistical insignificant difference in drug release.     

Effects of time and concentration of sodium ascorbate on reversal of NaOCl-induced reduction in bond strengths

The use of NaOCl as an endodontic irrigant lowers the bond strength of resin cements but this can be reversed by the use of 10% sodium ascorbate for 10 min. The objective of this study was to evaluate the effect of time and concentration of ascorbate at restoring the bond strength. Group 1 roots were prepared using 0.9% NaCl as an irrigant; group 2 roots were irrigated with 5.25% NaOCl; group 3 roots were irrigated with 5.25% NaOCl followed by 10% ascorbate for 10 min; group 4 roots were irrigated with 5.25% NaOCl followed by 10% ascorbate for 3 min; group 5 roots were irrigated with 5.25% NaOCl followed by 10% ascorbate for 1 min; and group 6 roots were irrigated with 5.25% NaOCl followed by 20% ascorbate for 1 min. All roots were then filled with C&B Metabond, stored 1 day in water, and then cross-sectioned into 6 slabs, 1 mm thick, that were trimmed and tested for tensile bond strength. The results demonstrated that 5.25% NaOCl irrigation produced (p < 0.05) significant reduction in resin-dentin bond strengths, but this can be reversed by 10% ascorbate treatment for 1 min.