Isokinetic gradient centrifugation prolongs survival of pig islets xenografted into mice

The shikimate pathway presents an attractive target for malaria chemotherapy. Three shikimic acid analogs exhibited different effects on Plasmodium falciparum growth. (6R)-6-Fluoro-shikimate and (6S)-6-fluoro-shikimate inhibited growth (50% inhibitory concentrations, 1.5 x 10(-5) and 2.7 x 10(-4) M, respectively), whereas 2-fluoro-shikimate had no effect. para-Aminobenzoic acid abrogated the inhibition, demonstrating that the shikimate pathway was specifically targeted.     

Acute pulmonary histoplasmosis as an imported disease

A previously healthy 44-year-old male traveller presented with a dry cough, fever and an abnormal chest X-ray after a stay in Guatemala, where he had explored bat caves. Acute pulmonary histoplasmosis was diagnosed after culture of Histoplasma capsulatum from bronchial washings. A favourable response was seen upon treatment with itraconazole for six weeks. Acute pulmonary histoplasmosis should be considered in a healthy traveller returning with fever from the USA or subtropical areas.     

Isolation, structure elucidation, and biological activity of the steroid oligoglycosides and polyhydroxysteroids from the Antarctic starfish Acodontaster conspicuus

A total of 19 steroids, of which 13 steroidal oligoglycosides (nine new and four known) and six polyhydroxylated steroids (four new and two known), has been isolated from the Antarctic starfish Acodontaster conspicuus. The mixture is dominated by glycosides composed of steroidal aglycons having the hydroxyl groups typically disposed on one side of the tetracyclic nucleus, i.e., 3 beta,4 beta,6 alpha,8,15 beta-, with some having a sulfate at C-6, and differing in the side chains and/or in the disaccharide moieties that are usually attached at C-26, with some at C-28 and C-29. Those compounds are accompanied by minute amounts of glycosides with a delta 8(14)-double bond in the steroid, which is a structural feature not previously found among polyhydroxysteroids derived from starfish. Small amounts of six related unglycosidated polyhydroxysteroids and three higher-molecular-weight asterosaponins complete the composition of the mixture. The structures of the new compounds were determined by interpretation of their spectral data and by comparison with spectral data of known compounds. Eighteen of these compounds were evaluated for their ability to inhibit growth in Antarctic marine bacteria isolated from either the water column or the surfaces of benthic marine invertebrates. Of these compounds, 50% were active against at least one Antarctic marine bacterium. This suggests that these compounds may play an important role in deterring microbial fouling.     

Management of ingested foreign bodies within the appendix: a case report with review of the literature

A case is reported of an elective appendectomy in a patient with known ingestion of a sharp foreign body. The metal drill bit was ingested unintentionally 3 months before presentation at our institution. Plain abdominal films demonstrated the foreign body in the right lower abdominal quadrant. Because the gold dental drill bit was sharp and thought to be lodged in the terminal ileum or cecum, an attempt was made to remove the object during colonoscopy. This attempt was unsuccessful because no drill bit could be detected in the colon or terminal ileum. A laparoscopic exploration was performed, and the foreign body was found to lie in the appendix, after bowel manipulation under fluoroscopic guidance and with direct laparoscopic visualization. A laparoscopic assisted appendectomy was performed. On pathologic examination the drill bit was embedded in the tip of the appendix with signs of intramucosal acute inflammation. Management and indication for surgery of foreign bodies in the appendix are discussed, and we review the related literature. This is the second reported case of a dental drill bit in the appendix causing appendicitis.     

Epilepsy, learning disability and anti-convulsant drug status

We describe the isolation of crotoxin, a presynaptic B-neurotoxin, as well as its subunits B (crotactine) and A (crotapotin) from lyophilized Crotalus durissus terrificus venom by a single-step preparative isoelectric focusing procedure. From 98 mg of dried venom protein 20.1 mg of crotactine and 13.1 mg of crotapotin were recovered in the first step of focalization and 4.2 mg in a second run. These values correspond to 35.7% of the total venom protein applied. Crotactine separated in the 9.3-7.0 pH range (tubes 1-6) and crotapotin in the 1.8-2.8 pH range (tubes 15-19) and both were homogeneous by SDS-PAGE and N-terminal amino acid analysis. Crotactine, a 12-kDA protein, presented hemolytic and phospholipase A2 activity. Thus, using isoelectric focusing we simultaneously purified both toxins in high yields. This method can be used as an alternative for the purification and characterization of proteins from other snake venoms under conditions in which biological activity is retained.