pH and energy dependent transport of ketoprofen across rat jejunum in vitro.

The aim of this study was to elucidate transport mechanisms of ketoprofen (monocarboxylic acid with pK(a) 4.6) across rat jejunum in vitro using side-by-side diffusion cells. When the tissue was incubated on the mucosal and serosal sides with buffer of pH 7.51 (pH of the mucosal surface was 7.08), ketoprofen permeated faster in the mucosal-to-serosal than in the opposite direction. No asymmetry in transport was observed when 2 mM mucus disrupting agent 1,4-dithio-DL-threitol (pH of the mucosal surface increased to 7.21) was added to the mucosal side. Mucosal-to-serosal permeability of ketoprofen increased three times when the pH of the incubation medium was changed from 8.06 (pH of the mucosal surface was 7.34) to 6.07 (pH of the mucosal surface was 5.95), while no pH dependence was found under ATP-depletion caused by sodium azide. In the ketoprofen concentration range from 0.125 to 5 mM no saturation of transport was observed. Moreover, ketoprofen transport was not changed in the presence of 2 mM benzoate, 10 and 20 mM acetate, 20 mM L-lactate (substrates for monocarboxylate transporter 1, MCT1) and 1 mM alpha-cyano-4-hydroxy-cinnamic acid (an inhibitor of MCT1). These results indicate that ketoprofen is transported across rat jejunum in vitro by pH and energy dependent transport mechanisms, and most probably not by MCT1.     

Surprisingly quick development of squamous cell carcinoma in chronic skin ulcer]

Malignant transformation of skin epithelium caused by chronic wound exudation in the absence of osteomyelitis is a rare event. The paper reports a case of 50 year old Caucasian male who presented with an exophytic tumor on the right hand. The tumor rapidly developed within previous area of unhealed skin wound that had existed only for about 5 months. Histological examination of the excised tumor revealed highly differentiated squamous cell carcinoma (SCC). At that time of surgery nearby lymph node biopsy didn't reveal evidence for metastatic spreading. Patient underwent the limb salvage procedure with tumor resection followed by two stage, cross-flap skin plasty. This report indicates that there is a need to expand knowledge about SCC and about the treatment of the patients with these tumor by surgeons practicing in small medical centers.     

Affinity fractionation of lymphocytes using a monolithic cryogel

A new type of continuous, supermacroporous, monolithic, cryogel affinity adsorbent was developed, allowing specific fractionation and separation of human peripheral blood lymphocytes in a chromatographic format. The affinity adsorbent was used to design a novel cell separation strategy, which was based on the interaction of protein A from Staphylococcus aureus with cells bearing IgG antibodies on the surface. After treating lymphocytes with goat anti-human IgG(H+L), the IgG-positive B-lymphocytes were efficiently separated from T-lymphocytes. Protein A covalently coupled to epoxy activated dimethylacrylamide (DMAA) cryogel matrix specifically bound IgG-bearing B-lymphocytes through the Fc region, while non-bound T-lymphocytes passed through the column. More than 90% of the B-lymphocytes were retained in the column while the cells in the breakthrough fraction were enriched in T-lymphocytes (81%). The viability of the T-lymphocytes isolated was greater than 90%. The bound lymphocytes released by human or dog IgG recovered 60-70% of the B-cells without significantly impairing the cell viability. The technique can be applied in general to cell separation systems where IgG antibodies against specific cell surface markers are available.     

Automatic avoidance of obstacles is a dorsal stream function: evidence from optic ataxia

When we reach out to pick something up, our arm is directed to the target by visuomotor networks in the cortical dorsal stream. However, our reach trajectories are influenced also by nontarget objects, which might be construed as potential obstacles. We tested two patients with bilateral dorsal-stream (parietal lesions, both of whom were impaired at pointing to visual stimuli (optic ataxia). We asked them to reach between two cylinders, which varied in location from trial to trial. We found that the patients' reaches remained invariant with changes in obstacle location. In a control task when they were asked to point midway between the two objects, however, their responses shifted in an orderly fashion. We conclude that the dorsal stream provides the visual guidance we automatically build into our movements to avoid potential obstacles, as well as that required to ensure arrival at the target.     

Polypoid nonchromaffin paraganglioma of the duodenum

Summary A polypoid tumor was surgically removed from the second part of the duodenum of a 56-year-old male. The main body consisted of large epithelioid cells arranged in an adenoma like pattern of strands and nests. These cells were argyrophil and had marked nonspecific esterase activity. Unmyelinated nerves with proliferated Schwann cells accompanied these epithelioid cells together with scattered gangliocyte like elements. Ultramicroscopically, the epithelioid cells were seen to contain round electron dense granules, 150 nm in diameter on average. The tumor is considered to be a nonchromaffin paraganglioma, as it probably developed from paraganglion cells associated with small arteries or branches of the vagus nerve, or from the undifferentiated pluripotent APUD cells of the duodenum.