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Biomedical subjects

J C Forest

Publications and source records attributed to J C Forest.

At least 55 records · Page 3Linked to original sources
PubMed1987

Microporous hydrophilic polyurethane vascular grafts as substitutes in the abdominal aorta of dogs.

Polyurethanes are emerging as promising biomaterials. A microporous vascular graft fabricated from Mitrathane, a new polyetherurethane urea, appeared to be particularly interesting according to in vitro evaluation and was tested in vivo as an infrarenal aortic substitute (i.d. 5 mm) in 24 dogs. After implantation for scheduled periods ranging from 4 h to 6 mnth, morphology evaluation and healing analysis of the grafts were performed. At harvesting, 18 grafts were patent and 6 were thrombosed. The thrombosed grafts had been implanted for 4 h (1 graft), 1 mnth (2 grafts) and 6 mnth (3 grafts). No macroscopic deposits other than red mural thrombi were observed. At 1 mnth complete external encapsulation was observed in 2 grafts. The capsule then contracted and became thinner; over the long term it shrank, became translucent and incomplete at 6 mnth. Yellow and brown stains appeared on many of the grafts. Characterization of the brown stains showed them to be iron (Fe3+) and the yellow stains were associated with the deposition of a bile pigment (bilirubin).

Animals↗
PubMed1987

Quality-control scheme for blood glucose measured outside the laboratory.

We propose a quality-control (QC) scheme to evaluate the performance of blood glucose estimates made with a reflectometer in hospital wards or at home. We constructed a chart illustrating the comparison by regression analysis of the results of 254 reflectometer readings (y) and simultaneous capillary blood glucose analyses in the laboratory (x). Arbitrary acceptance limits around the regression line (y = 0.5 + 0.87x; r = 0.97, Sy/x = 0.8 mmol/L) were established, based on the mean +/- 2 SD of the reflectometer readings of a series of classes of 1.1 mmol/L interval, made with the results from the laboratory analyzer. Each ward using a reflectometer is provided with the QC chart, and the first blood glucose estimation with the reflectometer on each working shift is controlled by re-assay in the laboratory. If the reflectometer reading is outside the limits, the next glucose estimation is also re-assayed. If two consecutive readings are outside the limits, the reflectometer procedure is considered to be failing, the instrument's readings are not used for medical decisions, and remedial action is taken. The chart can also be used as a teaching tool for training the patients or the nurses and to evaluate individual performance.

Blood Glucose↗
PubMed1986

C-reactive protein as biochemical indicator of bacterial infection in neonates.

Serial quantitative measurements of C-reactive protein (CRP) were performed, using an automated enzyme immunoassay method, in 127 neonates (114 premature and 13 full-term) classified in three groups: neonates with a normal postnatal course (group 1, n = 69), neonates with clinical suspicion of bacterial infection but with negative cultures (group 2, n = 49), and neonates with proven bacterial infection (group 3, n = 9). A total of 545 serial serum CRP concentrations were determined. In group 1, CRP concentrations were below the detection limit of the method (10 mg/L) except in one neonate who suffered from neonatal anoxia but whose clinical course was uncomplicated (CRP: 31 mg/L within 24 h of life). Thirty-three neonates of group 2 had CRP values consistently below 10 mg/L while 16 had elevated CRP concentrations at least on one occasion ranging from 10 to 70 mg/L. Diagnoses other than bacterial infection could explain the raised CRP concentrations in neonates of group 2. CRP concentrations were found to be elevated (greater than 80 mg/L) during the course of infectious diseases in all neonates with proven bacterial infection (septicemia (4), pneumonia (1), multiple micro-abscesses (1), urinary tract infection (3]. Serial measurement of CRP concentrations are shown to be valuable in detecting bacterial infection in neonates as well as in following the efficacy of antimicrobial therapy.

Bacterial Infections↗
PubMed1986

Biochemical markers in the assessment of protein-calorie malnutrition in premature neonates.

We studied 135 premature newborns of 26 to 36 weeks gestation, divided into three groups: the control group, 66 premature infants with uncomplicated course; 51 premature neonates with appropriate birth weight for gestational age (AGA), who suffered from clinical problems that delayed oral feeding; and 18 premature infants with small birth weight for gestational age (SGA). When neonates of the same postnatal age were compared, prealbumin concentrations were the lowest in the SGA group at the third and fourth postnatal week. Although the AGA group had the most infants with serious illnesses and the lowest protein-calorie intakes, their prealbumin concentrations did not differ significantly from those of the control group. But when the infants of each group were subdivided on the basis of intakes and weight gain regardless of postnatal age, those with greater intakes showed significantly higher prealbumin values; however, in all groups, the infants with higher intakes were also significantly older. Total proteins and albumin showed similar changes in all groups. Prealbumin concentrations showed great interindividual variability in infants of the same postnatal age. We conclude that prealbumin, albumin, and serum total proteins are not sufficiently sensitive biochemical markers to assess alterations of the nutritional status of premature infants.

Anthropometry↗
PubMed1985

The Laboratory Information System (LIS): I-Application to the clinical chemistry laboratory.

The Laboratory Information System (LIS) was designed as a "turn-key" system. The main functions are operated interactively on a mini-computer which gives the laboratory complete control over daily processing. Collection of results from automated analyzers is accomplished via a micro-computer/micro-processor network. Links are provided with a central main frame computer for immediate patient identification and historical data processing. LIS is designed to manage all the operations involved in laboratory activities. The system has 14 major functions: registration of test requests, production of specimen collection sheets and identification labels, confirmation of specimen collection, production of aliquot labels, workload inquiry, production of worksheets, manual entry of test results, automated entry of test results, results inquiry, preliminary report, final report, daily activities reports, statistical reports, billing. System security is provided along three directions: data entry validation, system access control, and memory protection. The main advantages of LIS are: reduced clerical work, better evaluation of workload, faster communication, improvement of information given to the clinician: adapted reference values, interpretation, comments, improved retrieval operations, faster billing.

Autoanalysis↗
PubMed1984

Biological markers in major psychosis and alcoholism: phenotypic and genotypic markers.

Some basic concepts and trends which appear to be essential in the search for biological markers in mental disorders are discussed. Comments related to major psychosis and alcoholism are presented under three headings: (i) heterogeneity of disorders (ii) multifactoriality of disorders and (iii) mental disorders as genetically influenced disorders. Tentative classification and terminology of biological markers are given. Various types of phenotypic markers are discussed and alcoholism is taken as a model for a more detailed discussion of available putative phenotypic markers and of research strategies to be used, namely the pharmacological challenge in high risk subjects (e.g. ethanol and TRH challenge). Some highlights from the field of DNA markers are described, mainly the basic procedures which may be used to investigate genetic aspects of mental disorders by recombinant DNA technology.

Alcoholism↗
PubMed1984

Adaptation of the Syva EMIT-cad digoxin enzyme immunoassay technique on the Instrumentation Laboratory Multistat-III microcentrifugal analyzer.

The Syva EMIT-cad digoxin assay, a three-step manual enzyme immunoassay (EIA) technique, was adapted to be run on the Multistat-III microcentrifugal analyzer. This adaptation permits semiautomation of the procedure along with a sizable reduction in sample and reagent volumes. A 5-min pretreatment of a 100-microliters sample with 0.5 N NaOH is followed by a 15-min incubation with 625 microliters of the anti-digoxin antibody and enzyme substrate reagent. A 198 microliters aliquot of this mixture and 65 microliters of the second digoxin enzyme conjugate reagent are loaded separately onto the rotor by the loader module in two successive loading cycles. The final 30-min incubation is initiated by rotation in the analyzer module. Intraassay performance [coefficient of variation (CV)] using patient samples (n = 10) is 10.5% at 0.6 ng/ml, 10.2% at 1.4 ng/ml, and 10.5% at 2.9 ng/ml. Interassay performance (CV) using the Hyland Omega II (1.4 ng/ml) and Omega III (2.8 ng/ml) ligand quality control sera (n = 13) is 12.3% and 9.7%, respectively. Assay linearity is excellent up to 5.0 ng/ml. Correlation of the results with a radioimmunoassay (RIA) method is EMIT = 0.98 RIA + 0.02, r2 = 0.92, standard error of estimate = 0.23 (52 patient samples). The time required for a normal run (10 patients) or a single urgent analysis is approximately 75 min.

Autoanalysis↗
PubMed1983

Reference values for the oral glucose tolerance test at each trimester of pregnancy.

A 100-gram oral glucose tolerance test (OGTT) was performed on a selected group of normal women at each trimester of pregnancy to establish reference values for hyperglycemia and hypoglycemia. Ninety three OGTT were performed in the first trimester, 121 in the second trimester, and 98 in the last trimester. The fasting serum glucose did not differ significantly between the trimesters. The values at 60 and 120 minutes were significantly different for the fifth, fiftieth, and ninety-fifth percentiles between each trimester of pregnancy. For the 180-minute readings, the fifth and fiftieth percentiles were not significantly different between the first and second trimester of pregnancy, but the results of the third trimester were significantly higher than those of the other trimesters. The mean fasting insulinemia remained relatively constant during pregnancy. Insulin response to OGTT increased during the progression of the pregnancy. The interpretation of the glucose tolerance tests during pregnancy, either to detect gestational diabetes or hypoglycemia, should take these physiologic changes into account.

Blood Glucose↗
PubMed1983

Variations in amylase isoenzymes and lipase during acute pancreatitis, and in other disorders causing hyperamylasemia.

We compare the clinical value of assay of amylase (EC 3.2.1.1) isoenzymes with that of lipase (EC 3.1.1.3) in serum from patients with proven acute pancreatitis or with hyperamylasemia from other causes. In the former group we measured amylase, lipase, and isoamylases daily. Lipase and P(pancreas)-type isoamylases reached the highest mean values on the first day of an attack of acute pancreatitis (day one). Lipase declined rapidly, and by day four its mean activity was about the same as that of amylase and lower than that of the P-type isoamylases. Great inter-individual variations were found among patients with a similar clinical course. Of the 85 samples analyzed, amylase activity for 36 declined to within reference limits, but 18 of the 36 had high lipase activity, 18 had high P-type isoamylases activity, and 31 had P3 isoenzyme, which is not detectable in normal sera. Determination of isoamylases is a more sensitive index to acute pancreatitis than lipase assay and may be particularly useful when pancreatitis is suspected despite a normal total amylase activity. In the group of patients with hyperamylasemia from other origins, three had macroamylasemia, one had mumps, one had abdominal trauma without pancreatic injury, and one had pelvic inflammatory disease. The specific pattern of macroamylase on electrophoresis permitted a precise diagnosis of macroamylasemia; normal lipase had only ruled out pancreatitis. In the three other cases, lipase and isoamylases excluded pancreatic involvement.

Acute Disease↗
PubMed1983

Performance of the Hitachi 705 evaluated.

We evaluated a new discrete analyzer, the Hitachi 705. The instrument can process sequentially as many as 19 different enzymes or other analytes, with a throughput of 180 tests per hour. We evaluated the spectrophotometer, the sample and reagent probes, and the performance for 11 assays: creatine kinase, aspartate aminotransferase, alkaline phosphatase, gamma-glutamyltransférase, amylase, glucose, urea nitrogen, creatinine, albumin, calcium, and phosphorus. The total imprecisions (within-day plus day-to-day component of imprecision) (CV) were: for the photometer (six concentrations of potassium dichromate), 0.14 to 0.4%; for the serum probe (55 to 20 microL), 0.4 to 1.0%; for the reagents probes (50 to 350 microL), 0.3 to 1.2%; for the enzymatic procedures, 2.0 to 8.0%; and for the other tests (glucose, urea nitrogen, creatinine), 1.0 to 4.0%. Good linearity was obtained in the proposed range for the 11 tests, except for calcium. Comparison of the total analytical error with the medically allowable error at a decision value showed that the test results were acceptable, except for calcium and phosphorus. The instrument showed good reliability and practicability.

Autoanalysis↗
PubMed1982

Measurement of alpha-fetoprotein in maternal serum: three commercial radioimmunoassay kits and two non-commercial radioimmunoassays compared.

We evaluated three commercial radioimmunoassay kits (Amersham, Dainabot, Clinical Assays) and two non-commercial methods for determining alpha-fetoprotein in maternal serum during pregnancy. All five procedures were found to be acceptable with respect to practicability, sensitivity, linearity, and precision. Similar results were obtained with Dainabot, Clinical Assays, and the two non-commercial methods, but the Amersham method revealed a proportional error, results being about 20% lower than those by the other methods. Use of the international unit system is suggested for reporting results for AFP, to facilitate comparison between methods and laboratories.

Evaluation Studies as Topic↗
PubMed1982

Electrophoretic determination of isoamylases in serum with commercially available reagents.

We describe and evaluate a method for determining isoamylases in serum. With this method, which involves conventional electrophoretic apparatus and commercially available reagents, seven isoenzymes can be resolved. The electrophoresis is performed in agarose gel, and isoenzymes are detected with a water-insoluble cross-linked starch polymer linked to a blue dye. The isoenzymes are quantified by densitometry. Within-assay imprecision (CV) was less than 7%, between-assay CV less than 11%. This method has the sensitivity to detect the major isoamylases (P2 and S2) in the serum, even at low total amylase activity. Reference intervals for P-type isoenzymes were 2-52 U/L and for S-type 2-85 U/L. P2S2 is the most common pattern found in normal individuals, then (in decreasing order) P1P2S2, P2S2S3, and P2 patterns. Patterns found in serum from cases of acute pancreatitis, mumps, macroamylasemia, and pelvic inflammatory disease are illustrated.

Acute Disease↗