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.     

Markers of inflammation in induced sputum in acute bronchitis caused by Chlamydia pneumoniae

Little is known of the inflammatory characteristics of acute infections of the respiratory tract caused by virus and unusual bacteria such as Chlamydia pneumoniae. A case is reported in whom inflammatory indices in sputum were used to investigate, for the first time, the airway inflammation during an episode of acute bronchitis caused by C pneumoniae. The patient presented with a dry cough of five days duration. C pneumoniae was identified by polymerase chain reaction (PCR) in a nasopharyngeal swab collected on day 5. Virological studies were negative. Clinical and inflammatory indices in induced sputum were measured on days 6, 8, and 11. The cough cleared spontaneously by day 11. Forced expiratory volume in one second was normal throughout. Sputum findings identified intense airway inflammation characterised by increased total cell and lymphocyte counts followed by an increase in neutrophils and a decrease in the CD4/CD8 ratio, activation of CD8 lymphocytes, and exudation as indicated by an increase in fluid phase fibrinogen. These observations suggest that sputum might be useful to monitor an inflammatory/immune response of the airway in acute infections.


     

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.