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Biomedical subjects

K G Lofsness

Publications and source records attributed to K G Lofsness.

6 recordsLinked to original sources
PubMed2000

WHIM syndrome, an autosomal dominant disorder: clinical, hematological, and molecular studies.

The acronym WHIM refers to Warts, Hypogammaglobulinemia, Infections, and Myelokathexis. The latter refers to the retention of white cells in the marrow, which becomes hypercellular. We have found approximately 20 examples of WHIM syndrome in the literature under various designations; the first examples are Zuelzer [1964] and Krill et al. [1964]. Chronic noncyclic neutropenia and hypercellular bone marrow represent defective release of marrow cells into the peripheral stream (myelokathexis). The hypermature neutrophils are bizarre in form. Condensed nuclei connected by long, stringy filaments and vacuolated cytoplasm suggest apoptosis. Fever or other stress increases the release of neutrophils. Hypogammaglobulinemia is marked and associated with recurrent upper respiratory infections (sinusitis, tonsillitis, otitis media, pneumonia). Patients have numerous warts, some venereal, with resultant cervical and vulval premalignant dysplasia. We report on a kindred of 6 affected individuals in 3 generations with autosomal dominant WHIM syndrome. The sex ratio among reported patients and in our kindred is 17 female to 8 male. Because there had been no male-to-male transmssion, search of the entire X-chromosome including the pseudoautosomal area was carried out and no linkage was found. Recently, the propositus has had an unaffected daughter, confirming our finding that the gene is not X-linked. A genome-wide search is being carried out.

Adolescent↗
PubMed1994

Evaluation of automated reticulocyte counts and their reliability in the presence of Howell-Jolly bodies.

An automated reticulocyte procedure using a flow cytometer and the fluorescent dye thiazole orange was evaluated for clinical use. The mean reticulocyte count on 118 hematologically healthy adults was 1.56% (standard deviation [SD] 0.54), with virtually no difference in percentage between women and men. The mean absolute values were 68.4 x 10(9)/L (SD 24.6) and 75.7 x 10(9)/L (SD 27.2), respectively. When compared with the standard microscopic technique, the automated method showed excellent correlation (r = 0.98) and greatly improved precision (coefficient of variation [CV] 4.1%) over the manual method (CV 22.8%). Preanalytic storage of blood samples at 4 degrees C for up to 48 hours did not significantly affect results, nor did varying the incubation time of diluted samples from 1/2 to 2 hours. In a group of patients with appreciable numbers of Howell-Jolly bodies, automated reticulocyte counts were spuriously elevated. The difference between the manual and automated counts on these patients approximated the percentage of Howell-Jolly bodies observed on their Wright-Giemsa stained blood smears.

Adolescent↗
PubMed1987

Hematologic parameters and leukocyte histogram patterns in infectious mononucleosis.

Blood samples from 60 patients with serologically positive infectious mononucleosis were analyzed on the Coulter S-Plus IV. Hemoglobins and platelet counts were essentially normal, and leukocyte counts were elevated in less than half the cases. Reactive lymphocytes were present on blood smears from all patients. The S-Plus IV automated three-part leukocyte differentials showed significantly lower numbers of lymphocytes and more mononuclears and granulocytes than manual microscopic differentials. On the leukocyte histograms, lymphocyte peaks were consistently wider than normal and asymmetrical. The instrument generated R2 flags on 43 of 60 (72%) of the samples. Using a combination of "R" flags, mononuclear backlighting, and "H" flags, the Coulter S-Plus IV identified 59 of 60 infectious mononucleosis samples as requiring further review.

Adolescent↗
PubMed1985

Determination of passing scores on certification examinations: an unresolved issue.

In the field of clinical laboratory science, certification may be obtained by passing the National Certification Agency for Medical Laboratory Personnel (NCA) examination. This multiple-choice test is competence-based and criterion-referenced, and uses a modified Angoff procedure to establish the passing score. For this study, the NCA examination scores of 1,868 certification applicants (mostly new graduates) and 111 selected laboratory practitioners were compared. Although the NCA examination is designed to define the level of minimum competence, the failure rate of practitioners identified by their supervisors as minimally competent was almost four times greater that that of the certification applicants. Even the most competent group of practitioners scored well below the applicants for certification. These findings suggest that the examination cut-off point may not really define minimal competence and that the method used to determine the passing score might not be appropriate for certification examinations.

Certification↗
PubMed1983

The preparation of simulated spinal fluid for teaching purposes.

A simulated spinal fluid can be prepared by adding red and white blood cells and bovine serum albumin to a commercially available balanced salt solution. Using this preparation as a substitute for actual cerebrospinal fluid enables teachers to provide adequate quantities of microscopically positive fluid, and at the same time eliminates the danger of potential contamination. The appearance of the red and white cells, both in the hemocytometer and in a centrifuged and stained preparation, is realistic. This simulated spinal fluid is useful in teaching not only cell counting and identification techniques, but also total protein and glucose analyses. The method for preparing this solution is simple, inexpensive, and requires only equipment that is readily available to the teaching laboratory.

Cerebrospinal Fluid↗