Search PubMed⌕ Search

Biomedical subjects

C Collier

Publications and source records attributed to C Collier.

At least 37 records · Page 2Linked to original sources
PubMed1994

Monitoring of monoclonal gammopathies: rational use of densitometry and rate nephelometry.

The follow-up of patients with monoclonal gammopathies at our institution includes serial serum protein electrophoresis (SPE) with densitometry and IgG, IgA, and IgM quantitative immunoglobulin (QIG) determinations by rate nephelometry. This retrospective audit compares monoclonal protein concentration as estimated by SPE versus QIG in 456 serial serum specimens from 105 patients to determine whether any of the tests provide redundant information. A comparison of the methods demonstrated good correlation between SPE (x-axis) and QIG (y-axis) quantitation for each immunoglobulin class: IgG had a slope of 1.45 and an intercept of 1.60 (Sy/x = 7.46, r = 0.96, n = 250); IgA had a slope of 1.30 and an intercept of -1.37 (Sy/x = 6.85, r = 0.96, n = 78); and IgM had a slope of 1.95 and an intercept of 2.06 (Sy/x = 5.16, r = 0.98, n = 128). The data for individual patients showed similar good correlations. Exceptions included IgA peaks "buried" in the beta region of the SPE (resulting in invalid SPE estimates of monoclonal protein concentration), and IgG peaks of less than 10 g/L (when background polyclonal IgG immunoglobulin skews the QIG estimate of monoclonal protein concentration). An algorithm is proposed whereby monoclonal protein concentration is measured by the specific QIG (i.e., IgG, IgA, or IgM) determination for the routine monitoring of patients, except for those with IgG peaks of less than 10 g/L that are followed by SPE.

Blood Protein Electrophoresis↗
PubMed1994

Preliminary report on cell encapsulation in a hydrogel made of a biocompatible material, AN69, for the development of a bioartificial pancreas.

The occurrence of an inflammatory reaction represents the major obstacle to the development of any implantable system including micro and macroencapsulation. The purpose of this study was to describe an encapsulation method for cells using a membrane made of AN69, a copolymer of acrylonitrile which is considered as a reference in biocompatibility in the field of haemodialysis. The hydrogel of AN69 was obtained after a coagulation step at room temperature followed by a solvent/non-solvent (water) exchange phase. Microcapsules were obtained by co-extrusion of AN69 collodion and saline (with or without cells). The function of encapsulated cells was assessed in vitro, demonstrating cell survival after the microencapsulation procedure. These preliminary data are consistent with the potential interest for the development of the microencapsulation procedure aimed at realising a bioartificial pancreas.

Acrylic Resins↗
PubMed1992

Minimodule dialyser for quantitative ex vivo evaluation of membrane haemocompatibility in humans: comparison of acrylonitrile copolymer, cuprophan and polysulphone hollow fibres.

Minimodule hollow fibre dialysers, representing clinical dialysis modules on a scale of 1/25, enable quantitative evaluation of the haemocompatibility of hollow fibre membranes in an ex vivo flow system in humans. On line heparinization, adjusted for donor sensitivity, is maintained at a minimal level (approximately 0.14 units/ml). Blood samples collected at the minimodule exit over 30 min are analysed for heparin (anti-Xa activity), activated partial thromboplastin time, fibrinopeptide A, platelet count and beta-thromboglobulin, complement fragment C3a, leucocyte count and polymorphonuclear neutrophil elastase. Initial experiments were performed using well-characterized reference materials: acrylonitrile copolymer (AN 69 HF), polysulphone and cuprophan (CUP). Activation of coagulation and platelets was low for AN 69 HF, intermediate for CUP and greatest for polysulphone, while complement activation was negligible in the presence of AN 69 HF, moderate for polysulphone and most important for CUP. Future applications will be directed towards haemocompatibility screening of prototype membranes with the aim of developing clinical dialysers with improved biocompatibility.

Acrylic Resins↗
PubMed1990

High in vitro spontaneous histamine release in long-term hemodialyzed patients.

Adverse reactions, such as skin flush and pruritus, have been observed among hemodialyzed (HD) patients. A potential relationship between hemodialysis and allergic phenomena prompted us to investigate some allergologic parameters. Total IgE, specific IgE antiethylene oxide and anti-isocyanate toluene diisocyanate, and in vitro spontaneous histamine release (SHR) were measured in 105 long-term stable HD patients. Thirty-two of the patients had occasionally developed skin flush reactions and/or pruritus during dialysis sessions. Blood samples were taken at the start of dialysis, sera were kept frozen until assay, and in vitro SHR was performed on washed leukocytes at 37 degrees C for 40 minutes. A high (range, 20% to 80%) and reproducible in vitro SHR was observed among 24% of patients. No correlation was found between SHR and the type of dialysis membrane used (copolymer of acrylonitrile-methallyl-sodium sulfonate, cuprophan, and polysulfone). High SHR (i.e., greater than 20%) was observed mainly among patients with detectable antiethylene oxide IgE antibodies (p less than 0.001). High levels of IgE (greater than 300 ng/ml), specific IgE antibodies, and a high in vitro SHR were all observed concomitantly in 26% of the patients with skin flush reactions and/or pruritus, whereas all three of these parameters together were present in only 3% of the symptom-free patients. To our knowledge, this is the first time that a high in vitro SHR has been described among HD patients, and putative correlations with in vivo phenomena are discussed.

Adolescent↗
PubMed1987

Community hospital surgeon-specific infection rates.

A one-year prospective study of surgeon-specific nosocomial infection rates was done in two community hospitals. Hospital A (93 beds) and Hospital B (158 beds) have nearly identical surgical staffs. Unified criteria for the diagnosis of infections, methods of data collection, and coding were used. Data were processed with an IBM 370 computer using Statistical Analysis System (SAS). Each surgeon received semiannual reports of 1) overall infection rate by site, 2) number of surgical wound infections by wound class and type of procedure, 3) pathogens for each deep and incisional infection, and 4) quarterly wound infection rates by wound class. Analysis of reports revealed high Class I surgical wound infection rates for both general and orthopedic surgeons. One person in each group had inordinately high infection rates. These data serve as an objective incentive to reduce surgical wound infections, identify individual problems, and suggest surgical privileges be evaluated by performance.

Cross Infection↗
PubMed1987

Studies on the metabolic behaviour of industrial actinide-bearing aerosols after deposition in the rat lung: an experimental basis for interpreting chest monitoring data and assessing limits on intake for workers.

UNLABELLED: The metabolism of 239Pu and 241Am in 3 site-specific industrial dusts has been studied after their deposition in the rat lung. A comparative experiment has also been carried out with a mixture of these actinides inhaled as their nitrates. The aim of this study was to provide an experimental basis for assessing limits on intake and to establish whether the 239Pu content in the lungs could be interpolated from measurements of 241Am. THE RESULTS: 1 demonstrate the wide differences in the lung retention kinetics of the actinides and in the absolute and relative amounts translocated to the blood that can occur for industrially produced materials; 2 show that the annual limits on intake (ALIs) for the different materials vary between those postulated for class W and Y compounds by the International Commission on Radiological Protection; 3 indicate that acute intakes of 239Pu equivalent to the ALI can, depending on the nature of the dust, be estimated from 241Am chest monitoring data at times from a few days up to about 3 years after exposure.

Aerosols↗
PubMed1986

Operating room surveillance: a new approach in reducing hip and knee prosthetic wound infections.

A prospective study of surgical wound infections (SWI) in hip prosthesis surgery and total hip and knee replacements at two community hospitals with common surgical staffs was begun in May 1982. The rates of SWI during the first 7 months for four orthopedic surgeons were 9% (3/32) for hip prosthesis surgery and 16.7% (3/18) for total hip and knee replacement, with 12% (6/50) overall. To reduce infections, each orthopedic surgeon agreed to intraoperative surveillance (IOS) of two procedures (hip prosthesis or total hip or knee replacement) by the infection control nurse at each hospital. Significant IOS findings were too many persons in the operating room (five to nine persons), operating room doors opened frequently (25 to 50 times), inconsistent use of prophylactic antibiotics, and excessive conversation. In January 1984, IOS data and recommendations were shared with each orthopedic surgeon, the operating room staff, and the anesthesia personnel. Subsequently, a statistically significant drop in SWI was realized for total hip and knee replacement (1/36 versus 5/36, p = 0.05) and overall (3/73 versus 14/116, p = 0.05). The drop in SWI for hip prosthesis surgery was not statistically significant (2/37 versus 9/80, p greater than 0.10). IOS and individualized communication were effective in reducing SWI.

Aged↗