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S McClure

Publications and source records attributed to S McClure.

33 records · Page 2Linked to original sources
PubMed1989

Distinction of microcytic disorders: comparison of expert, numerical-discriminant, and microcomputer analysis.

Presumptive distinction between iron deficiency and heterozygous thalassemia by analysis of the automated blood count and differential continues to be a challenge. We compared two proposed numerical discriminants (MCV2 x MCH, and MCV2 x RDW/100 x Hb) with an analytic microcomputer program (BCDE2 Lea & Febiger). In 7114 subjects, the numerical discriminants and the BCDE2 program correctly identified greater than 90% of thalassemia. In subjects with iron deficiency, the BCDE program was greater than 90% sensitive and specific for positive identification, while the numerical discriminants were less than 75% sensitive and specific at inferential identification. The numerical discriminants, BCDE2, and 17 experts in blood counting were asked to interpret the blood-count data in 7 fully-defined actual cases. The mean experts' score was 5.65 cases correct out of 7. The BCDE program was correct in all cases. The numerical discriminants could not analyze all cases, and both were incorrect in at least one case. We conclude that for the task of analyzing blood counts for microcytic disorders, microcomputer analysis by BCDE outperforms both numerical discriminant functions and analysis by expert hematologists.

Anemia, Hypochromic↗
PubMed1988

A novel glycoprotein expressed on sheep T and B lymphocytes is involved in a T cell activation pathway.

We have produced a new mouse mAb that identifies a sheep T cell activation Ag. The mAb B5-5 is specific for low m.w. components on nearly all sheep thymocytes and peripheral T and B lymphocytes but does not label immature B cells in Peyer's patches or germinal centers. After cross-linking of target structures either directly by plastic-bound mAb or indirectly using anti-Ig reagents, peripheral T cells, but not thymocytes or peripheral B cells, were activated. IL-2 was secreted by T cells after cross-linking and activation was strongly augmented in the presence of PMA. The addition of soluble B5-5 mAb to mitogen-stimulated cultures of sheep lymphocytes resulted in a suppression of PHA responses and augmentation of PWM responses and had a variable effect on Con A responses but had no effect on LPS- or protein A-induced proliferation. When added to alloantigen-stimulated cultures, B5-5 augmented the proliferative response. The B5-5 membrane component consists of 14- to 19-kDa glycoproteins but the banding patterns obtained during SDS-PAGE analysis of 125I-labeled Ag differed between thymocytes, peripheral T cells, and peripheral B cells. On the basis of its range of expression on lymphoid cells and known biochemical and functional properties, we conclude that the B5-5 component on sheep lymphocytes is different from T cell activation Ag in other species.

Animals↗
PubMed1988

Maturation of immunological reactivity in the fetal lamb infected with Akabane virus.

The development of cell-mediated immunological reactivity was studied in fetal lambs infected with Akabane virus. Examination of hepatic cells from fetuses between 40 and 75 days' gestation that had been infected via the transplacental route revealed inconsistent responses to Akabane, together with a uniform failure to respond to non-specific mitogens which contrasted with the behaviour of control, uninfected lambs. Following direct inoculation of fetal lambs with virus between 50 and 120 days' gestation, specific proliferative responses were observed on the part of the spleen cells from some. Direct challenge of fetal lambs of 4 months' gestation evoked cellular responses in lymph draining from the site of virus inoculation similar to those produced by challenge of adult sheep. The proliferative response of lymph-borne cells was substantially better if live, rather than inactivated, virus had been used.

Animals↗
PubMed1988

Transmission of Akabane virus from the ewe to the early fetus (32 to 53 days).

The role of the placental junction in AKA virus infection in the ewe was examined during the time when the chorionic villi were first becoming firmly attached to the maternal caruncles. The studies were made over 21 days covering the period between 32 and 53 days of pregnancy. Viral tropism in the fetal membranes and tissues of the fetuses was identified by virus isolation and immuno-fluorescence studies. Areas of virus replication were noted from 24 h post-inoculation in the fetal membranes and persisted in these tissues throughout the experiment. Viral antigen was first detected in the fetus from day 5 post-inoculation by virus isolation and immuno-fluorescence. From this time on, viral activity increased in specific areas of the fetus, notably in the brain and, to a lesser extent, the skeletal muscles. Gross pathological changes occurred in the fetuses between day 14 and day 21 post-inoculation (46 to 53 days gestation). Despite the relatively high titres of AKA virus present in the placental tissues and the developmental changes occurring in the fetus due to the virus, the placental junction continued to carry out its physiological function of maintaining pregnancy.

Animals↗
PubMed1988

The "diff-if". Use of microcomputer analysis to triage blood specimens for microscopic examination.

Increasingly, all automated blood counts are not accompanied by a microscopic white blood cell differential. A popular strategy is to obtain a manual differential if any part of the automated blood count and differential is outside specified limits (the "diff-if" strategy). The authors compared two sets of criteria to triage blood counts for manual differentials: previously recommended numeric values, and the analysis of a microcomputer program. In a population of subjects with a high percentage of hematologic disorders, the microcomputer program and the numeric criteria were equally specific (excluding normal blood smears); the program was more sensitive for bands, immature granulocytes, monocytes, nucleated red blood cells, reticulocytosis, teardrops, red blood cell fragments, and hypersegmented neutrophils. The numeric criteria were more sensitive for eosinophilia (less than 1.0 X 10(9)/L) and mandated fewer manual differentials. In a population of predominantly normal subjects, the program was more sensitive for increased bands and equally sensitive for eosinophilia, the only abnormalities observed on the smear. In a population of subjects with predominantly abnormal blood counts, but excluding most primary hematologic disorders, there were few blood smears with abnormalities beyond eosinophilia or increased bands. In both of these groups, the computer program mandated more manual differentials than did the numeric criteria. The authors conclude that microcomputer analysis by the program tested was more sensitive than numeric criteria to identify specimens with abnormal blood smears. Specificity depended on the patient population. The choice of a triage strategy should be based on the individual laboratory's patient population.

Blood↗
PubMed1988

Analysis of cell division among subpopulations of lymphoid cells in sheep. I. Thymocytes.

The number, distribution and surface phenotype of dividing cells in the thymus, and differences between the cell cycle status of thymocyte subpopulations, were studied in fetal and post-natal lambs using double-labelling techniques. Dividing cells were labelled in vivo for various periods with 5-bromo-2-deoxyuridine (BrdU). The proportions of constituent thymocyte subpopulations that had synthesized DNA during the labelling period were measured by flow cytometry or immunohistochemistry using a panel of monoclonal antibodies (mAbs) specific for sheep lymphocyte differentiation antigens and MHC class I and class II antigens in conjunction with an anti-BrdU mAb. The proportion of thymocytes that incorporated BrdU during a 1-hr labelling period varied with age, and levels of 30%, 13% and 9% were measured, respectively, in 40- and 125-day-old fetuses and 8-week-old lambs. Eight percent of the thymocytes in lambs were synthesizing DNA, with 4% entering the G2 phase per hour, and a substantial number of thymocytes (21%) had a G2 + M phase DNA content. A small subset of thymocytes (1-3%) recognized by mAb E-79 localized to the subcapsular region of the cortex and displayed the highest level of BrdU incorporation. Cortical-type thymocytes (CD1+) comprised 50-70% of thymocytes; however, few of these incorporated BrdU and the proportion in the G2 + M phase of the cell cycle was higher than for other thymocyte subpopulations. The 197+CD4-CD8- T cells also showed no evidence of in vivo division.

Animals↗
PubMed1988

Analysis of cell division among subpopulations of lymphoid cells in sheep. II. Peripheral lymphocytes.

The number, distribution and surface phenotype of dividing cells in lymph nodes and blood and differences between the cell-cycle status of lymphocyte subpopulations were studied in lambs using double-labelling techniques. Dividing cells were labelled in vivo for various time periods with 5-bromo-2-deoxyuridine (BrdU). After removal of lymphoid tissues, the proportions of constituent lymphocyte subpopulations which had synthesized DNA during the labelling period were measured by flow cytometry or immunohistochemistry using a panel of monoclonal antibodies (mAbs) specific for sheep lymphocyte differentiation antigens and MHC class I and class II antigens in conjunction with an anti-BrdU mAb. There was a higher overall level of cell division in the ileocaecal lymph node than in either the prescapular or parathymic lymph nodes. In all three lymph nodes, the majority of lymphocytes which incorporated BrdU occurred in B-cell follicles or germinal centers. CD4+ and CD8+ T cells had a higher level of cell division (LI 5-14%) than those recognized by mAb 197 (CD4- CD8- subset) (LI less than or equal to 3%).

Animals↗
PubMed1985

Improved detection of early iron deficiency in nonanemic subjects.

We measured the complete blood cell count, including the index of RBC size heterogeneity (RBC distribution width [RDW]), in 181 subjects without anemia to determine whether RDW became abnormal earlier in the development of iron deficiency than did other variables. In 163 subjects selected only for otherwise normal blood cell counts, an increased RDW was 66% specific (48/73) and 100% sensitive (48/48) for decreased serum iron saturation. Stool guaiac testing was equally specific but less sensitive. In 13 subjects with polycythemia, as iron deficiency developed, RDW increased a minimum of four weeks before mean cell volume changed. In one apparently normal young woman, an abrupt isolated rise in RDW revealed a newly developed low serum transferrin saturation; all values remained normal during serial testing of four other normal subjects. We conclude that RDW is the part of the routine blood cell count that first becomes abnormal during the development of iron deficiency.

Adult↗
PubMed1985

Characteristics and correlates of MMPI change within an adult psychiatric inpatient setting.

This study investigated characteristics and correlates of MMPI change scores among 188 male and female inpatients who were assessed at admission and upon completion of a 9-week residential program. Predictor variables included admission scores from the standard 13 MMPI scales, the Internal-External Locus of Control Scale, the trait component of the State-Trait Anxiety Inventory, and Shipley-Hartford Verbal IQ scores, as well as demographic variables including factors that involved psychiatric history. Outcome variables consisted of change scores based on raw score values for each of the 13 MMPI scales. Results of a canonical correlation indicated a significant relationship between predictor and outcome variables, which cumulatively accounted for 27% of the variance of outcome change scores. Findings were discussed in terms of implications for research and theory in the areas of the measurement of psychological change through use of the MMPI.

Adult↗
PubMed1984

Cellular responsiveness in vitro: the effect of mycobacterial glycopeptides, glycolipids and peptidoglycolipids on the in vitro growth of haemopoietic colony-forming cells.

Incorporation of glycopeptide, glycolipid and peptidoglycolipid preparations from the culture fluid or organisms of a variety of mycobacterial species in suboptimally stimulated cultures of normal mouse bone marrow cells increased the responsiveness of colony-forming cells to colony-stimulating factor, as measured by enhanced colony formation. Possible mechanisms of action and the significance of enhanced colony growth in relation to the mode of action of mycobacterial adjuvants are discussed.

Animals↗
PubMed1982

Budd-Chiari Syndrome and antithrombin III deficiency.

Presented herein is a case report of a 20-year-old woman with a past history of oral contraceptive use who developed Budd-Chiari syndrome. Onset of her illness was abrupt and stormy, simulating fulminant viral hepatitis or toxic hepatic injury. She died within six months of her initial presentation. Although the patient discontinued the use of oral contraceptives two years prior to the initial presentation of the disease, the morphologic features of the venous thrombosis and hepatic damage were indicative of a chronic, ongoing process of longer than six months' duration, thus raising the possibility of a cause-effect relationship between the "pills" and thrombotic process. Of interest was the finding of persistently depressed antithrombin III levels. While a relationship between oral contraceptive usage, antithrombin III deficiency and the Budd-Chiari syndrome is strongly suggested in this case, prospective studies are needed to substantiate this view.

Adult↗
PubMedDate not supplied

Peripherally inserted central catheters. Guidewire versus nonguidewire use: a comparative study.

To date, no research articles have been published that explore the practice of using guidewires for placement of peripherally inserted central catheters. The literature contains speculations regarding the pros and cons of guidewire use. However, no studies to date have compared patient outcomes when peripherally inserted central catheter lines are inserted with and without guidewires. To examine the use of guidewires for peripherally inserted central lines, a comparative study was conducted at two acute care facilities, one using guidewires for insertion and one inserting peripherally inserted central catheter lines without guidewires. 109 catheters were studied between January 1, 1990 and January 1, 1991. The primary focus of this study was to examine whether guidewire use places patients at higher risk for catheter-related complications, particularly phlebitis. No significant differences in phlebitis rates between the two study sites were found. Other catheter-related and noncatheter-related complications were similar between the two facilities. The results of this study do not support the belief that guidewire use increases complication rates.

Adolescent↗