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Biomedical subjects

M Clay

Publications and source records attributed to M Clay.

At least 37 records · Page 2Linked to original sources

Granulocyte antigens and antibodies.

Granulocyte-specific antigens defined by human alloantisera are clinically important in neonatal neutropenia, autoimmune neutropenia, transfusion reactions, drug-induced immune neutropenia, and poor response to granulocyte transfusions. Many different antigens have been defined by human alloantisera using different assays. Only antigens of the N system of Lalezari are commonly studied today. The composition and location of these antigens within the granulocyte membrane are not known, but work is now proceeding on those issues. It also appears that these antigens may have some structural or functional role in the granulocyte. Although many myeloid MoAbs have been developed, there are very few reports to establish whether these identify structures that are related to the N series of granulocyte antigens. However, these MoAbs can serve as excellent reagents for better understanding the granulocyte membrane. It appears that studies during the next several years will provide exciting information about the structure-function relationships in the granulocyte membrane.

Antibodies↗

Protective effect of methylxanthines against carbachol-induced bronchoconstriction in normal subjects.

The bronchoprotective effect of bioequivalent doses of theophylline (TH; 234 mg) and a combination of TH, proxyphylline (PPH) and diprophylline (DPH) in the proportion 2:3:3 (Neo-Biphyllin, NB; 600 mg) against carbachol-induced bronchoconstriction was studied in 10 healthy non-smokers in a randomised controlled double-blind cross-over trial. The subjects were on a methylxanthine-free diet 4 days prior to and during each study day. Bronchial provocation tests were conducted in the morning and afternoon of the three separate study days--control and two medication days--using a standardised technique. On the control day, the dose of carbachol required to reduce the partial expiratory flow volume at 25% of vital capacity (V25p) by at least 25% was established. A significant protective effect was achieved with both TH (p less than 0.05) and NB (p less than 0.001) as measured by V25p. Bronchoprotection was achieved with low maintenance serum levels of TH.

Adult↗

Three sera defining a new granulocyte-monocyte-T-lymphocyte antigen.

Three sera containing antibodies recognizing a previously undescribed antigen on granulocytes were found during testing of sera from multiparous donors. All of the antibody producers were in good health. None had a history of transfusion. Using the granulocyte agglutination assay the sera recognize a single antigen which is not associated with the neutrophil antigens NA1, NA2, NB1, NC1, ND1, NE1, 5a, 5b, 9a, nor common red blood cell or HLA antigens. The three sera did not react with autologous cells or with the cells of the other antibody producers. Granulocytes from one antibody producer did not absorb antibody activity from any of the three sera. The antigen was found in large quantities on granulocytes and monocytes, in smaller quantities on T lymphocytes, and not on B lymphocytes, red cells, and platelets. The sera reacted with 340 of 343 random donors (99.1%) and were negative with the same donor cells. Family studies showed autosomal dominant inheritance of the antigen. Five of 12 sibs in three families lacked this antigen (not statistically different from the expected ratio). The calculated gene frequency for the gene controlling the production of this antigen is 0.906. There appeared to be no association to the HLA, NA or Rh loci or to the X or Y chromosomes. None of the infants of these three women showed clinical signs of alloimmune neonatal neutropenia.

Adult↗

Effect of leukocyte antibodies and HLA matching on the intravascular recovery, survival, and tissue localization of 111-indium granulocytes.

The effect of leukocyte antibodies detected under different conditions on the fate in vivo of granulocytes was studied using 111-indium-labeled granulocytes. Sera from patients were tested by granulocyte agglutination (GA), granulocytotoxicity (GC), granulocyte immunofluorescence (GIF), lymphocytotoxicity (LC), and antibody-dependent lymphocyte-mediated granulocytotoxicity. Granulocytes from donors to be studied were labeled with 111-indium and injected. Then the intravascular recovery and survival or tissue localization was determined in 93 studies. Antibodies detected by granulocyte agglutination were associated with a significant reduction in recovery (6.7% v 30.8% in controls; P less than .001) and t1/2 (0.3 hours v 5.6 hours in controls; P = .002). When all possible combinations of serum reactivity were considered, reactivity in the GA plus GIF assays had the best correlation with decreased recovery (R2 = .49; P less than .001) and t1/2 (R2 = .73; P less than .001). When the relationship between the strength of antibody reactivity and the recovery and t1/2 were analyzed, the best relationship was between the combination of LC and GIF with recovery (R2 = .62; P = .001). Because of the general availability of the HLA (LC) testing, the role of LC reactivity was investigated in other ways. There was a strong relationship between sera highly reactive by LC and those reactive by GIF. These highly reactive sera were also associated with reduced recovery and t1/2. The influence of specific HLA antigen mismatches was also studied. When donor and recipient were mismatched for the HLA-A2, B8, or BW44 antigens, there was a significant reduction in either recovery, t1/2, or both. Tissue localization was studied by body scans in patients with and without known sites of inflammation. Antibodies detected by a combination of GA and GIF caused abnormal pulmonary sequestration of granulocytes (three cases) and failure of granulocytes to localize at known sites of inflammation (three cases). HLA (LC) antibodies did not alter tissue localization despite the presence of the corresponding HLA antigens on granulocytes. It appears that GA, GIF, or a combination of these tests is the most effective predictor of altered in vivo fate of granulocytes. However, sera highly reactive by LC and GIF probably define a group of highly immunized patients in whom granulocyte recovery and t1/2 are also reduced. Mismatching for certain HLA antigens is also associated with reduced granulocyte recovery and survival. At present, GA, with or without the immunofluorescence assay, is the most effective predictor of altered in vivo granulocyte activity.(ABSTRACT TRUNCATED AT 400 WORDS)

Antibodies↗

Leptospiral exposure in Detroit rodent control workers.

Antibody levels to L. icterohemorrhagiae of rodent control workers and two control groups were compared with antibodies against five other leptospiral serotypes carried predominantly by species other than rats. Rodent control workers contact urban rats, 77 per cent of which are carriers of leptospiral organisms. Rodent control workers had higher antibody levels against L. icterohemorrhagiae than control groups (OR 4.37, 99 per cent CI = 3.0, 6.3 and OR 11.08, 99 per cent CI = 5.6, 22). Antibodies against the other five serotypes were almost non-existent in the study group.

Adult↗

Severe pulmonary hypersensitivity associated with passive transfusion of a neutrophil-specific antibody.

A life-threatening pulmonary hypersensitivity reaction accompanied by profound leucopenia and transient hypocomplementaemia developed in a 73-year-old man after repair of an abdominal aortic aneurysm. A neutrophil-specific antibody, anti-NA2) was demonstrated by granulocyte immunofluorescence and microagglutination in one of the transfused donor units. In addition, activated complement component C5a was generated in vitro by incubation of the patient's serum with the aortic graft material. This severe clinical reaction may have resulted from the interaction of the transfused anti-NA2 antibody with complement activation induced by the aortic graft material.

Aged↗

Development of an empathic interaction skills schedule in a nursing context.

This study was an attempt to develop a means of teaching and assessing empathic interaction skills in the classroom and in the clinical situation. A descriptive-analytic system of interaction observation was formulated from a theoretical standpoint, with videotape recordings of nurse-patient interactions used as an additional data base. The schedule was applied to both student and qualified nurses in a variety of clinical settings and in the classroom. The videotape recordings were used as a means of assessing the validity and reliability of the schedule. The validity was ascertained in terms of content validity and criterion-related validity. These two aspects of validity were appraised by reference to the professional judgement of experienced qualified nurses. Positive validity coefficients were obtained. The reliability was determined by estimation of inter-rater reliability and intra-rater reliability. Positive reliability coefficients were obtained. Observer objectivity was also calculated.

Education, Nursing↗

Antibody-dependent lymphocyte-mediated granulocytotoxicity (ADLG) for the detection of granulocyte antibodies.

An antibody-dependent cell-mediated granulocytotoxic assay (ADLG) has been developed to detect antibodies to human granulocytes. This study examines some possible variables in this assay, the ADLG activity in serum from normal individuals, the contribution of ABO isohemagglutinins and the sensitivity and specificity of this technique. Significant differences in percentage cytotoxicity of ABO compatible and incompatible cell/serum combinations were detected in the normal population. Human serum with antibodies to the neutrophil specific antigens NA1 and NB1 gave positive results in the ADLG assay. However, differences in sensitivity and specificity were observed among various sera. ADLG activity was dependent on the source of effector cells. Effector and target cells stored in vitro were unsatisfactory in this assay. The ADLG assay may be a valuable addition to existing granulocyte serological methods and provide useful clinical information on mechanisms of immune neutropenias.

ABO Blood-Group System↗

Moral reasoning and the student nurse.

The traditional curriculum in nurse education has tended to emphasize the acquisition of knowledge and practical skills and to ignore, for the most part, close examination of the social and moral dimensions of the nurse's role. The authors suggest that we ought to include a much more substantial consideration of moral issues in the nurse education and, in particular, they argue that Kohlberg's model of moral development could provide a theoretical framework. This model is based on a cognitive-developmental approach in which an individual's level of reasoning is assessed by the use of a variety of hypothetical dilemmas. Kohlberg claims to identify six qualitatively distinct stages and argues that the transition from one stage to the next results from the individual's active attempts to resolve conflicts arising from moral dilemmas. Some suggestions are made about the ways in which discussion of moral dilemmas might be incorporated within a moral reasoning module in the nurse education curriculum and proposals are made for methods of teaching such a module.

Cognition↗

Intra- and interstrain differences in models of "behavioral despair".

In the present studies, base line and drug-induced performance of two mouse strains (C57Bl/6 and NIH-Swiss) was evaluated in the forced swim test (FST) and tail suspension test (TST). Intra- and interstrain comparisons indicate that the biological substrates mediating performance in these behavioral procedures are not identical. For example, in NIH-Swiss mice, a sevenfold difference in base line immobility was observed between the FST and TST. By contrast, the base line immobility in C57Bl/6 mice was similar in both procedures. Further, in C57Bl/6 mice, imipramine produced a "U-shaped" dose-response curve in the FST, whilst no evidence of a biphasic response was present in the TST at doses up to 45 mg/kg. In the FST, the AMPA receptor potentiator LY451646 produced a similar dose-response relationship in C57Bl/6 and NIH-Swiss mice, but the minimum effect dose (MED) was fivefold higher in NIH-Swiss mice. This potency difference appears due to both pharmacokinetic and pharmacodynamic factors. These intra- and interstrain differences in performance indicate that despite a face value similarity, the neurochemical pathways involved in mediating performance in these two widely used tests are not identical.

Animals↗

The frequency of granulocyte-specific antibodies in postpartum sera and a family study of the 6B antigen.

We examined sera from 2313 postpartum women as a potential source of granulocyte specific antibodies. Lymphocyte cytotoxic (LC) antibodies were detected in 397 (17.2%) specimens and granulocyte agglutinating (GA) antibodies in 291 (12.6%). Only two GA positive sera had reactivity for previously defined granulocyte specific antigens (one NA1 and NB1 ). One additional serum had GA reactivity similar to a serum previously reported by van Rood and called anti-6B. The frequency of granulocyte specific antibodies (0.1 percent) in our study indicates that the productivity of random screening of parous sera for granulocyte specific antibodies is low. A four-generation family study of the 6B antigen demonstrated a parallel association between HLA-B7 and B40 and 6B reactivity in the LC, GA, and granulocyte immunofluorescence (GIF) assay. This illustrates that the granulocyte reactivity of anti-6B is not granulocyte specific but is HLA related. This report provides additional evidence that HLA antibodies such as anti-B7 (6B) can react with granulocytes bearing these antigens in the GA and GIF assays currently used to identify granulocyte specific antibodies.

Antibody Specificity↗

Effect of ABO incompatibility on the fate in vivo of 111Indium granulocytes.

The effect of ABO incompatibility on the in vivo fate of 111Indium granulocytes was determined. The intravascular recovery and survival (t1/2) and extravascular migration into a skin window of normal-donor granulocytes did not differ in 15 subjects from the values obtained in four controls who received ABO-compatible granulocytes. Nor was the correlation between the ABO antibody titers and the in vivo measurements strongly positive. It is concluded that ABO incompatibility did not alter the in vivo fate of granulocytes.

ABO Blood-Group System↗

Autoimmune neutropenia of infancy and early childhood.

Forty-one children were identified with autoimmune neutropenia of infancy and early childhood (absolute neutrophil count [ANC] less than 500/microliters and demonstrable serum antineutrophil antibodies). There were 21 boys and 20 girls; the median age at diagnosis was 11 months (range 5-38 months). No life-threatening infections occurred. There was a gradual upward trend in ANC in all patients over many months, with 87% having an ANC > 1000/microliters by 24 months from diagnosis. Among various clinical and laboratory parameters analyzed statistically, only younger age at diagnosis was associated with earlier neutrophil recovery. There was no association between degree or duration of neutropenia and sex, race, antibody reactivity, or presence of serious illness at diagnosis.

Age Factors↗

Pressure sore prevention in nursing homes.

Staff working in nursing homes are caring for increasingly dependent residents who are consequently at great risk of developing pressure sores. Mary Clay offers a guide to the essential principles of pressure sore prevention as a teaching aid for all caring staff.

Activities of Daily Living↗