Biomedical subjects

J Winkelman

Publications and source records attributed to J Winkelman.

At least 19 recordsLinked to original sources

PubMed1994

Automated reticulocyte counting and measurement of reticulocyte cellular indices. Evaluation of the Miles H*3 blood analyzer.

This study evaluated reticulocyte counting and measurement of reticulocyte cellular indices with the Miles H*3 blood analyzer, a new instrument that combines the Technicon/Miles technology for blood cells counting with a staining technique allowing counting of reticulocytes, quantification of staining intensity and measurement of reticulocyte cellular indices. Reticulocyte counts obtained with the Miles H*3 analyzer were compared with those obtained by manual counting, flow cytometry (thiazole orange method) and by the Sysmex R-3000 (Baxter Diagnostics) reticulocyte analyzer. Reticulocyte counting with the Miles H*3 showed excellent precision, and linearity in the range tested (1.1-49% and 1-72% reticulocytes, respectively, with two different protocols) with no significant carryover. Reticulocyte counts were stable after storing blood samples for 72 hours at 4 degrees C. Comparison of the four different methods, showed an acceptable intraclass correlation between Miles H*3 and Sysmex R-3000 (intraclass correlation coefficient, [ri] = .952), Miles H*3 and flow cytometry (ri = .922), and Sysmex R-3000 and flow cytometry (ri = .938). There was no satisfactory correlation between any of the three automated methods and the values obtained with manual counting of reticulocytes (ri = .538-.755), consistent with the well known imprecision of the manual technique. For a group of normal pediatric subjects, age 1-10, we obtained the following values (+/- SD) of reticulocyte indices: mean corpuscular volume 97.6 +/- 4.7 fL; cell hemoglobin concentration mean 28.2 +/- 1.4 g/dL; cell hemoglobin content 26.7 +/- 1.6 pg. We determined the direct cost, including depreciation, of the manual and instrumental methods. Cost/test varied from $1.61 for manual method to $6.03 for the Sysmex R-3000. Cost/test for flow cytometry and Miles H*3 were $3.34 and $3.49, respectively.

Child↗

PubMed1991

Continuous arterial and venous blood gas monitoring during cardiopulmonary bypass.

A new monitoring technique, based on optical fluorescence chemistry, allows continuous monitoring of all blood gas variables during cardiopulmonary bypass. To evaluate the clinical performance of this monitor, we drew 220 arterial and 216 venous blood samples from 15 patients, and simultaneous blood gas values displayed by the monitor were compared with standard laboratory measurements. The continuous monitor predicted laboratory values with varying degrees of accuracy. (R2 values by linear regression: arterial oxygen tension 0.86, venous oxygen tension 0.36, arterial carbon dioxide tension 0.58, venous carbon dioxide tension 0.72, arterial pH 0.53, venous pH 0.58; pH 0.53, venous pH 0.58; p less than 0.0001). Monitor values of arterial oxygen tension overestimated laboratory values (bias = + 43.5 mm Hg), but the laboratory reference method likely underestimated true arterial oxygen tension in the high range achieved on bypass. Monitoring of venous oxygen tension was imprecise (precision = +/- 6.51 mmHg), regardless of whether stable conditions existed during the sampling period. Monitoring of carbon dioxide tension and pH showed small bias (carbon dioxide tension within 2 mm Hg, pH within 0.03) and good precision (carbon dioxide tension within 3 mm Hg, pH within 0.03). With the development of unstable conditions on bypass, monitor arterial oxygen tension values showed a changing relationship to corresponding laboratory values. In conclusion, arterial and venous carbon dioxide tension and pH monitoring provide acceptably accurate alternatives to laboratory measurement of these variables during cardiopulmonary bypass. Arterial oxygen tension monitoring accurately indicates changes in oxygen tension in the arterial oxygen tension range typically produced during extracorporeal circulation. Oxygen tension monitoring in the venous oxygen tension range is too imprecise for clinical decision-making purposes.

Aged↗

PubMed1989

Detection of specific IgG and IgA antibodies to Chlamydia trachomatis in women with salpingitis confirmed by laparoscopy.

The sera from 12 consecutive symptomatic women with laparoscopy-confirmed salpingitis were screened for the presence of specific IgG and IgA antibodies to Chlamydia trachomatis by a single antigen (L-2) immunoperoxidase assay. All women were found to have IgG and IgA antibodies to C trachomatis. Six women had positive endocervical cultures for C trachomatis, and one of these had positive cultures from the conjunctiva and fallopian tubes. Serum chlamydial IgA antibodies may serve as markers for active infection with C trachomatis regardless of whether organisms can be identified by culture or direct fluorescent antibody techniques from endocervical or fallopian tube samples.

Antibodies, Bacterial↗

PubMed1988

Prevalence of IgA and IgG antichlamydial antibodies in women in the third trimester of pregnancy.

The prevalence of serum antichlamydial IgA and IgG antibodies was investigated by screening 77 randomly selected patients who were in the third trimester of pregnancy. An indirect immunoperoxidase assay that quantitates IgA and IgG was used for screening. Twenty-five women had both IgA and IgG antibodies; an additional ten women had only IgG antibodies. These findings suggest that greater than 45 percent of pregnant women tested had been exposed to Chlamydia trachomatis, and more than 32 percent had evidence of active infection.

Chlamydia Infections↗

PubMed1988

A comparison of culture, direct fluorescent antibody test, and a quantitative indirect immunoperoxidase assay for detection of Chlamydia trachomatis in pregnant women.

An indirect immunoperoxidase assay that quantitates antichlamydial immunoglobulin G (IgG) and IgA antibodies in serum was compared with endocervical culture and direct fluorescent antibody (MicroTrak) for detection of Chlamydia trachomatis in asymptomatic pregnant women. Of the 64 women tested by the three methods, 22 (34%) had antichlamydial IgG and IgA in their serum. The culture was positive in nine patients (14%) and the MicroTrak was positive in eight (12.5%). All positive cultures were immunoperoxidase-positive. One positive MicroTrak was immunoperoxidase- and culture-negative. Thirteen patients had IgG and IgA antichlamydial antibodies with no organisms detected in the endocervix by culture or by direct fluorescent antibody screen.

Cells, Cultured↗

PubMed1984

Regulation of the oxidative burst of macrophages by lipid mediators.

Macrophages, on stimulation, generate both cyclo-oxygenase and lipoxygenase products of arachidonic acid as well as the acetylated phospholipid, PAF-acether. The latter induces the oxidative burst in C. parvum-activated macrophages, but has little activity on resident macrophages. Mouse macrophages are generally rather insensitive to PAF-acether. Prostaglandin (PG)E2, on the other hand is a potent inhibitor of the macrophage oxidative burst, though its activity is also dependent upon the source of the macrophages and the stimulus used. Several lipoxygenase inhibitors inhibit the oxidative burst of mouse peritoneal macrophages, while other authors have reported stimulatory effects of lipoxygenase products on different macrophage populations. The differential actions of lipoxygenase and cyclo-oxygenase products on the macrophage oxidative burst are reflected by the effect of arachidonic acid on the zymosan induced response of mouse resident peritoneal cells: initial enhancement, followed by prolonged inhibition, the latter being indomethacin-sensitive. While PAF-acether is probably an important initiator of the macrophage oxidative burst in vivo, arachidonic acid modulates the response by a "see-saw mechanism", lipoxygenase products being stimulatory and cyclo-oxygenase products (mainly PGE2) being inhibitory.

Animals↗

PubMed1972