Proposal for a less cumbersome anesthesia workstation

Conclusions With adaptation and implementation of these concepts, current problems with today's anesthesia workstations can be overcome. The problems of information management and workstation layout will be of less significance.     

Stereotactic brain biopsy in AIDS

Summary In the hope of finding a treatable condition, the need for rapid diagnosis in HIV-seropositive patients with brain lesions is apparent. In order to evaluate the efficacy of stereotactic brain biopsy in AIDS patients, we retrospectively studied 25 HIV-infected patients undergoing stereotactic biopsy. Brain lesions were identified with gadolinium-enhanced MRI and/or contrastCT. Brain biopsy was performed using the system of Riechert. From 8 up to 15 small tissue samples from one or two targets were obtained in every patient. The biopsy material was examined cytologically, histologically (including electron microscopy), immunohistochemically and, in part, by animal test and polymerase chain reaction (PCR). A definite diagnosis was achieved in 92%. Diagnosis included primary central nervous system lymphoma (PCNSL) (10), toxoplasmosis (10), progressive multifocal leukoencephalopathy (2) and one case of co-existing toxoplasmosis and cytomegalovirus infection. Two biopsies were non-diagnostic. All PCNSLs showed polymorphic B-cell populations of high malignancy; accurate classification according to the Kiel classification was not possible. In 3 lymphomas Epstein-Barr nuclear antigen (EBNA) 2-mRNA could be detected by PCR and confirmed immunohistochemically by EBNA 2 expression. In 6 cases autopsy confirmed the biopsy diagnosis. Conventional histology was not sufficiently decisive for toxoplasmosis and progressive multifocal leukoencephalopathy, so that immunohistochemistry and animal tests became very important for a final diagnosis. With the help of different morphological and molecular biological techniques stereotactic brain biopsy appears to be an effective method in the diagnosis of HIV-associated brain lesions. In view of the marked radio- and chemosensitivity of PCNSLs it is mandatory to establish an early and accurate histological diagnosis for adequate treatment.     

Effects of different perfusates on functional parameters of isolated perfused dog kidneys.

BACKGROUND: The isolated perfused canine kidney has been established as a valid model for conducting both renal physiology and transplantation research. This model is of particular importance for developing new strategies to improve graft function after renal transplantation. In the present study, a newly developed method using isolated haemoperfused porcine kidneys was adapted for use in canine kidneys. In contrast to haemoperfusion, synthetic perfusion media can be standardized and can prevent the initiation of blood-mediated reperfusion reactions. Thus, an additional aim was to determine whether blood could be replaced by synthetic cell-free perfusion solutions. METHODS: Canine kidneys (n = 30) were harvested from donors euthanized in veterinary practices for causes unrelated to the present study. The kidneys were isolated and perfused with autologous blood or cell-free synthetic electrolyte buffer (Tyrode solution). During perfusion, we monitored renal perfusate flow (RPF), glomerular filtration rate (GFR), electrolyte and glucose reabsorption, oxygen consumption and urine concentration. RESULTS: Changes in perfusion medium did not affect the RPF. In contrast, GFR, urine concentration and oxygen consumption were significantly higher, whereas fractional excretion of sodium and glucose were significantly lower in blood- than in Tyrode-perfused kidneys. CONCLUSIONS: This system offers a simple model for studying whole-organ functional alterations after acute renal ischaemia. Renal function indicators were below values reported during in vivo physiological conditions. These functions were better conserved when kidneys were perfused with autologous blood than with Tyrode.     

Nitroblue-tetrazolium test for the functional evaluation of phagocytic cells: A critical analysis of the methodology

The reduction of NBT to formazan has been suggested as an indicator of the reduction potential of biological systems. An increase in the amount of reduced formazan reflects the activation of the hexose monophosphate shunt of phagocytes cultivated in vitro, as a result of cellular stimulation by chemical or biological factors, or during phagocytosis. This phenomenon has been widely used for the determination of activated phagocytes by different methods. However, the technical limitations of these methods have not been evaluated carefully. In the investigations presented here threesolvents for formazan, pyridine, dioxane and dimethylformamide, have been tested for their suitability as extraction agents. For each solvent the optimal wavelength for photometric evaluation has been determined and dose relation curves between dissolved formazan and OD have been established. Several factors (time, temperature, pH, contamination with water or acid) affecting the dissolving properties and stability of formazan in different solvents have been investigated. With the solvents tested, dioxane proved to be the most suitable agent for extracting NBF. Thus, a methodology for the quantitative evaluation of NBT has been established. This method can be used for the identification of activators as well as of inhibitors of the phagocyte system.     

One-year results: palatal implants for the treatment of obstructive sleep apnea.

OBJECTIVE: To evaluate long-term effectiveness of palatal implants for treatment of mild to moderate obstructive sleep apnea (OSA). STUDY DESIGN: A prospective study of 26 referred patients with a pretreatment apnea-hypopnea index (AHI) of 10 to 30 and a body mass index of < or =30, representing an extended follow-up of a subset of 41 patients enrolled in previous short-term trials. RESULTS: Twenty-one of 26 patients (80.8%) experienced a decrease in AHI. Fifteen of 26 patients (57.7%) had a follow-up AHI <10 at 1 year, whereas 13 patients (50%) had a 50% or greater reduction to an AHI <10 at 1 year. Mean AHI was reduced from 16.5 +/- 4.5 at baseline to 12.5 +/- 10.5 at 3 months (P < 0.014) and to 12.3 +/- 12.7 at 1 year (P < 0.019). CONCLUSIONS: Patients initially responding to palatal implants with improved AHI maintained improvement through long-term follow-up at 1 year.     

Cyto- and genotoxic effects of coordination complexes of platinum,palladium and rhodium in vitro

The growing industrial use of platinum group elements as catalysts, especially in automobile exhaust detoxification (trimetal catalytic converters), is causing increasing occupational and environmental pollution. The cytotoxic and mutagenic properties of industrially used coordination complexes of platinum, palladium and rhodium were investigated using the neutral red cytotoxicity assay on two established cell lines and theSalmonella typhimurium/microsome test system (Ames test). Cytotoxic effects of the platinum complexes, measured as ED₅₀, occurred at test concentrations of 0.2 mM. The analogous palladium salts tested were 3 times less toxic with ED₅₀ being 0.6 mM, while the rhodium salts proved to be 30 times less toxic (ED₅₀=6 mM). Levels of toxicity of the different complexes of a particular metal did not differ significantly from each other, which indicates that the metal itself is responsible for the toxic effects. In the Ames test, the spontaneous mutation rates increased by factors of 3 to 20 when the four tester strains were exposed to the platinum complexes. The analogous rhodium compounds proved to be considerably less mutagenic, and palladium demonstrated no mutagenic potential. As all of the four tester strains contain different mutations, the mutagenic potential of platinum and rhodium complexes appears to be based on a variety of mechanisms that damage DNA. From these in vitro experiments, it can be concluded that water-soluble complex salts of rhodium are less toxic and have a smaller mutagenic potential than the analogous platinum complexes. For palladium there is no evidence of any mutagenic property. From this point of view, the development of a catalytic converter containing predominantly palladium may be a possible means of minimizing potential health risks from this exhaust detoxification technique.     

Neuropsychological, psychosocial and vocational correlates of the Glasgow Outcome Scale at 6 months post injury: a study of moderate to severe traumatic brain injury patients

Traumatic brain injury (TBI) subjects at Glasgow Outcome Scale levels 3 (severe disability), 4 (moderate disability), 5 (good recovery), and an other injury control group (OIC) were compared in terms of neuropsychological, psychosocial, and vocational functioning 6 months after injury. Subjects were a sample of 100 patients with a moderate to severe traumatic brain injury (TBI) and a matched sample of 30 other injury control subjects (OIC) enrolled in the UCLA Brain Injury Research Center study of TBI outcome. Overall, the results showed a systematic decrease in mean neuropsychological test performance as a function of increasing GOS severity, as well as an increased prevalence of symptoms of depression and lower ratings on measures assessing employability and capacity for self care. TBI patients in the 'severe' and 'moderate disability' groups were distinctly inferior to the 'good recovery' and 'OIC' groups, who were quite similar to each other in terms of cognitive, psychosocial, and vocational outcomes. The results demonstrate overall support for the predictive and concurrent validity of the GOS 6 months post injury. Despite these results, which strengthen the utility and appeal of the GOS for multicentre studies, concerns still remain regarding GOS category 4 (moderate disability), which was shown to lack sufficient discriminability in this study.