In-stent restenosis is caused by the proliferation of the smooth muscle cells (SMCs) following a host response towards the implanted device. However, the precise biochemical and cellular mechanisms are still not completely understood. In this paper, the behaviour of SMCs has been investigated by an in vitro model where the cells were stimulated by platelet derived growth factor (PDGF) on tissue-like substrates as well as on biomaterials such as stainless steel (St) and diamond-like carbon (DLC)-coated St. The results demonstrated that SMCs have a completely different adhesion mode on St and become particularly prone to proliferation and pro-inflammatory cytokine secretion under PDGF stimulus. This would suggest that restenosis may caused by the accidental contact of the SMC with the St substrate under an inflammatory insult.
The in vitro activity of sulperazon (cefoperazone/sulbactam) was tested against 94 ceftazidime-resistant strains of bacteria isolated from mostly seriously ill patients in critical care units. Acinetobacter baumanii, Pseudomonas aeruginosa and Klebsiella pneumoniae made up 80% of the pathogens studied; 90% of the Klebsiella strains were producers of extended-spectrum beta-lactamases (ESBL). The MIC90 of sulperazon for Klebsiella was 12 mg/l (range 1.5-16 mg/l), indicating that this drug may be a useful alternative for the treatment of ceftazidime-resistant, ESBL-producing Klebsiella.
170 clinical isolates of Pseudomonas aeruginosa were tested for in vitro susceptibility to gentamicin, amikacin, tobramycin, netilmicin, kanamycin, streptomycin, cefotaxime, ceftriaxone, cefoperazone, ceftazidime, moxalactam, azlocillin, piperacillin and ticarcillin. Against 93 gentamicin-sensitive strains, the most active antibiotics were in descending order, ceftazidime, tobramycin, gentamicin, amikacin, and the ureidopenicillins. Against 77 gentamicin-resistant strains, only ceftazidime, amikacin and moxalactam had mode minimum inhibitory concentrations within achievable peak serum levels after standard therapeutic dosage. There was no correlation between cephalosporin resistance and aminoglycoside resistance except for cefoperazone, which, together with the ureidopenicillins and ticarcillin, showed marked decrease in activity against gentamicin-resistant strains.
The effects of phentolamine and propranolol on contractural responses of guinea-pig superior mesenteric-portal vein to adrenaline and isoprenaline were investigated. Phentolamine was capable of completely abolishing the response to adrenaline and to isoprenaline while propranolol had no effect on responses to either agonist. It is suggested that Alpha receptors are the only type of adrenoceptor involved in adrenergic control of contraction of this vein and that isoprenaline is capable of stimulating these receptors.
Entamoeba histolytica, the causative agent for human amoebiasis, is among the most deadly parasites, accounting for the second highest mortality rate among parasitic diseases. Because this parasite dwells in low oxygen tension, for its cultivation, microaerophilic conditions are required to mimick the human gut environment. Several methods developed for optimal growth environment are commercially available and some are conventionally modified in-house which include the Anaerocult A and oil blocking preparation methods. This study was undertaken to compare the reliability of the Anaerocult A and the oil blocking methods in generating anaerobic environment for cultivation of E. histolytica. The trophozoites of E. histolytica HM1: IMSS strains were axenically cultivated in TYI-S-33 medium in culture incubated anaerobically by using Anaerocult A (Merck) and mineral oil blocking method. The outcomes of both methods were determined by the minimum inhibitory concentration (MIC) of metronidazole against E. histolytica by giving a score to the growth pattern of the trophozoites. The reliability of both methods was assessed based on susceptibility testing of E. histolytica to metronidazole. The MIC obtained by both anaerobic condition methods was 6.25 ug/ ml, thus showing that oil-blocking method is comparable to the Anaerocult A method and therefore, considered as a reliable method for generating an anaerobic environment for the cultivation of E. histolytica.