Micrococcus luteus: a rare pathogen of valve prosthesis endocarditis]

A rare case of prosthetic valve endocarditis caused by Micrococcus luteus is described and compared with the few cases reported in the literature, as well as the clinical features, microbiological profile, therapy, and prognosis of common prosthetic valve endocarditis. Micrococcus luteus is a constituent of the normal human buccal bacterial flora which forms yellowish colonies and appears as a gram-positive coccus typically arranged in tetrades. Although of low virulence, the germ may become pathogenic in patients with impaired resistance, colonizing the surface of heart valves. In contrast to staphylococci (for which it may easily be mistaken) it is usually penicillin-sensitive. However, the most promising antibiotic regimen proposed for treatment of Micrococcus luteus seems to be a combination of vancomycin, amikacin, and rifampicin. If the infection leads to severe hemodynamic alterations, however, valve replacement may become necessary similar to the situation in prosthetic valve endocarditis caused by more aggressive and highly resistant bacteria.     

Delayed neurotoxicity of trixylenyl phosphate and a trialkyl/aryl phosphate mixture, and the modulating effect of atropine on tri-o-tolyl phosphate-induced neurotoxicity.

Two hydraulic fluids, Fyrquel EHC (trixylenyl phosphate) and Reofos 65 (trialkyl/aryl phosphate mixture), were examined for effects of organophosphorus-induced delayed neurotoxicity (OPIDN) in hens using the OECD Test Guideline (1984). Furthermore, the influence of atropine and the concentration of tri-o-tolyl phosphate (TOTP) in the oil vehicle on the development of OPIDN were investigated. For Fyrquel EHC a neurotoxic effect was demonstrated with single oral doses of 5, 10 and 15 g/kg. Reofos 65 caused no clinical neurotoxic effect after single oral doses of 5, 10 and 15 g/kg. Redosing at day 22 with Reofos 65 did not result in clinical delayed neurotoxicity, but minor histopathological changes were found in the spinal cord and peripheral nerves. Atropine 10 mg/kg im delayed the onset of OPIDN caused by TOTP 1 g/kg po without affecting the final neurotoxic effect. Dilution of TOTP in large amounts of soybean oil vehicle reduced its neurotoxic effect. In conclusion, the neurotoxic potential of the hydraulic fluids was very low. The effect of atropine and the concentration of the test compound in oil vehicle should be taken into consideration when designing experiments on OPIDN.     

Detection and localization of single-base sequence differences in foot-and-mouth disease virus genomes by the RNase mismatch cleavage method.

The RNase mismatch cleavage method was examined for its efficiency of indicating single-base sequence differences in the capsid protein-coding regions of different foot-and-mouth disease virus subtype O1 strains. The method was found suitable for indicating such differences. RNase A as well as RNase T1 contributed to substrate conversion. Examples for the cleavage of eleven different single-base mismatches in RNA double-strands are now known. All virus genomes found to differ from each other exhibited three or more non-neighboured single-base sequence differences. Other genomes found to be indistinguishable by this method were those of a recent field isolate adapted to cell culture, and those of a vaccine production strain; its progeny was transmitted to pig and cow and then analyzed. The results suggest that host change does not necessarily select for antigenic variant virus, and that virus submitted to some kind of selection pressure is changed at more than one position.     

Localized 1H NMR spectra of glutamate in the human brain.

Localized 1H NMR spectra at TE = 12 ms were obtained from cerebral cortex of human subjects using ISIS with surface suppression. The 2.29-ppm resonance was assigned to C4 glutamate with contributions from C4 glutamine and GABA using in vivo spectral editing and comparison of chemical shift with pure compounds. The measured intensity ratio between the 2.29 resonance and the creatine resonance at 3.03 ppm was in good agreement with the ratio predicted from previously reported measurements of glutamate, glutamine, and GABA concentrations in biopsied human brain tissue.     

The incidence, timing, and management of biliary tract complications after orthotopic liver transplantation.

OBJECTIVE: This study analyzed the incidence and timing of biliary tract complications after orthotopic liver transplantation (OLTx) in 1792 consecutive patients. These results were then compared with those of previously reported series. Finally, recommendations were made on appropriate management strategies. SUMMARY BACKGROUND DATA: Technical complications after OLTx have a significant impact on patient and graft survival. One of the principal technical advances has been the standardization of techniques for biliary reconstruction. Nonetheless, biliary complications still occur. A 1983 report from the University of Pittsburgh reported biliary complications in 19% of all transplants, and an update in 1987 reported biliary complications in 13.2% of transplants. METHODS: The medical records of all patients who underwent liver transplantation and were hospitalized between January 1, 1988 and July 31, 1991 were reviewed. The case material consisted of the medical records of 217 patients treated for 245 biliary complications. RESULTS: Primary biliary continuity was established by either choledochocholedochostomy over a T-tube (C-C, n = 129) or a Roux-en-Y choledochojejunostomy with an internal stent (C-RY, n = 85). The overall incidence for biliary complication in this large series was 11.5%. Strictures (n = 93) and bile leak (n = 58) were the most common complications (69.6%). Most biliary complications (n = 143, 66%) occurred within the first 3 months after surgery. In general, leaks occurred early, and strictures developed later. Bile leaks were equally frequent in both C-C and C-RY (27.1% and 25.9%, respectively); strictures were more common after a C-RY type of reconstruction (36.4% and 52.9%, respectively). Twenty-one patients died, an incidence of 9.6%. Fifteen of the 21 biliary-related deaths were among patients treated for rejection before the recognition of biliary tract pathologic findings. CONCLUSIONS: Progress has been made on improving the results of biliary reconstruction after OLTx. Nonetheless, patients continue to experience biliary complications after OLTx, and these complications cause considerable loss of grafts and life. If significant additional improvement in patient and graft survival are to be obtained, the technical performance of OLTx must continue to improve.     

Presentation, clinical features and outcome in different patterns of atherosclerotic renovascular disease

Atherosclerotic renovascular disease (ARD) is an increasinglyimportant cause of renal failure. However, important featuresof the clinical presentation are not fully described, and theoutcome after intervention by angioplasty remains controversial.Ninety-four patients with ARD diagnosed at angiography werereviewed. Twenty-four patients were diabetic. Thirty-nine patientshad unilateral renal artery stenosis or occlusion (group A),28 had bilateral stenosis (group B), and 27 had unilateral occlusionplus contralateral occlusion or stenosis (group C), Two yearsafter presentation, actuarial patient survival was 96%, 74.3%and 47.1% in groups A, B and C, respectively (p<0.001 forall differences); actuarial renal survival in surviving patientswas 97.3%, 82.4% and 44.7%, respectively (p<0.001 for alldifferences). Percutaneous transluminal balloon angioplasty(PCTA) was performed in 74 patients. Renal function improvedin only a minority of cases, but was stable in 73% of nondiabeticpatients 12 months after PCTA. Angioplasty was less effectivein diabetic subjects, with only 53.3% having stable renal functionat 12 months follow-up. Renal and patient survival were stronglyrelated to the initial angiographic findings. In nondiabeticsubjects, PCTA resulted in stabilization of renal function forat least one year in nearly threequarters of cases, which suggestsa benefit from intervention in this disease whose natural historyis otherwise of progression.