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Biomedical subjects

M Armstrong

Publications and source records attributed to M Armstrong.

At least 145 records · Page 8Linked to original sources
PubMed1981

The reliability of IgA antibody to Epstein-Barr virus (EBV) capsid antigen as a test for the diagnosis of nasopharyngeal carcinoma (NPC).

Since patients with nasopharyngeal carcinoma were first reported to have elevated levels of IgA antibody to Epstein-Barr virus (EBV) in their sera, workers in a number of countries have studied the possibility that this assay could be used in the diagnosis and monitoring of patients with this disease. In the United States, a collaborative project involving seven centers has been established to investigate the potential value of IgA antibody to EBV viral capsid antigen (VCA) as a clinical tool. In this report, we will summarize the results obtained from three studies: a comparison of EBV serology in three laboratories; a retrospective study of 37 nasopharyngeal carcinoma (NPC) patients and controls, and a prospective study of 126 NPC patients and 683 controls, including 149 patients with other malignancies involving the head and neck. The study of testing comparability in three laboratories demonstrated the feasibility of using this assay in a number of laboratories. The retrospective study confirmed the difference in IgA antibody titers between NPC patients and matched controls. The prospective study showed a relationship between IgA antibody titers and histopathology but not disease stage. IgA antibody titers were elevated more frequently in patients with nonkeratinizing or poorly differentiated types of NPC than for the well-differentiated squamous cell carcinomas. While IgA antibodies to EBV VCA appear to be of value in the early detection and diagnosis of NPC, it is possible that additional serologic tests for immunity to EBV, such as IgG antibody to VCA or early antigen (EA), will improve even further the clinical value of EBV serology in the management of NPC.

Antibodies, Viral↗
PubMed1980

Assertiveness training with high school students.

Baseline assessments of assertiveness were determined prior to instituting a 10-week assertion training program with 85 ninth-and twelfth-grade adolescents. Initial self-report measures of assertiveness indicated that females experienced significantly more discomfort in assertion situations than males. Baseline measures also revealed that while assertiveness increased with age in males, it decreased over grade levels with females. Data from the baseline assessments were used to structure an intervention program in which subjects were randomly assigned to groups which received assertiveness training twice a week for one hour. Prior to data analysis, each group was classed as either high- or low-cohesive. The results indicated a significant increase in assertiveness in the highly cohesive training groups on a behavioral measure of assertiveness.

Adolescent↗
PubMed1979

Measles virus-specific antibodies and immunoglobulin M antiglobulin in sera from multiple sclerosis and rheumatoid arthritis patients.

When rheumatoid factor in rheumatoid arthritis and multiple sclerosis sera was titrated by the fluorescent antibody method on measles virus-infected cells, there was a marked and variable drop in titer on acetone-fixed cells as compared with unfixed cells. This was accounted for by the failure of measles virus hemolysin-inhibiting (HLI) antibody of the immunoglobulin G class to bind to acetone-fixed infected cells. It was shown by staining unfixed and acetone-fixed measles virus-infected cells that rheumatoid factor in most rheumatoid arthritis sera combined with measles virus-specific hemagglutinin-inhibiting and HLI antibodies, whereas rheumatoid factor in multiple sclerosis sera combined only with HLI antibody. Rheumatoid factor of similar specificity was also observed in normal sera and occasionally in rheumatoid arthritis sera. Both rheumatoid arthritis and multiple sclerosis sera showed almost identical increases in average titer above normal of measles virus-specific fluorescent staining immunoglobulin G and HLI antibodies.

Adult↗
PubMed1979

Affinity for measles virus anti-haemolysin of a residual immunoglobulin M in sera of some patients with multiple sclerosis.

HEp2 cells persistently infected with measles virus were treated with trypsin to remove haemagglutinin (HA) and examined unfixed or fixed in acetone by fluorescent antibody methods, comparing those sera specific for structural antigens of the virus. Staining patterns combined with the blocking of specific immunofluorescence indicated that IgG specific for measles virus haemolysin could be recognized in multiple sclerosis (MS) sera and that in some sera from which rheumatoid factor had been removed, a residual IgM (MS-IgM) was absorbed to measles virus-infected cells and showed the same specificity in blocking tests as measles virus anti-haemolysin. MS-IgM could be removed from sera by absorption with latex particles coated with human IgG and would seem to be anti-globulin with preferential affinity for anti-haemolysin.

Acetone↗
PubMed1978

Taurine: an essential nutrient for the cat.

Cats fed a purified diet containing purified casein as the source of protein develop retinal degeneration due to the lack of taurine in the diet. To test whether cats can synthesize this sulfur amino acid from sulfate or cystine, radioisotopes of these substances were injected into taurine-depleted and control cats. Sulfate did not serve as a precursor for taurine synthesis, whereas cystine underwent only a moderate conversion to taurine. This is in keeping with the low level of cysteinesulfinic acid (CSA) decarboxylase activity in cat liver. There was no difference between the activity of CSA decarboxylase in tissues from control cats and that in tissues from taurine-depleted cats. The pattern of tissue accumulation of [35S]taurine and from [35S]cystine also indicated that tissues from taurine-depleted cats do not synthesize [35S]taurine more rapidly than tissues from control cats. The data did not indicate a difference in taurine uptake by tissues of control and deficient cats, but progressive accumulation in deficient cats suggested that the turnover rate of taurine is decreased by the deficiency. Since supplementation of the purified diet with cysteine has been found previously to be inadequate to prevent progressive taurine depletion of the retina and its subsequent degeneration and since conversion of sulfur compounds to taurine in vivo is inadequate, taurine can be considered an essential nutrient for the cat.

Animals↗
PubMed1968

Production and elimination of disruptive classroom behavior by systematically varying teacher's behavior.

The effects of teacher behaviors on the classroom behaviors of children were investigated by systematically varying approving (praise, smiles, contacts, etc.) and disapproving (verbal reprimands, physical restraint, etc.) classes of teacher behavior. Measures were taken on both teacher and child behaviors. Each day a sample of 10 children was observed. The subject pool was a class of 28 well-behaved children in a middle-primary public school class. The results demonstrated that approving teacher responses served a positive reinforcing function in maintaining appropriate classroom behaviors. Disruptive behaviors increased each time approving teacher behavior was withdrawn. When the teacher's disapproving behaviors were tripled, increases appeared most markedly in the gross motor and noise-making categories of disruptive behavior. The findings emphasize again the important role of the teacher in producing, maintaining, and eliminating disruptive as well as pro-social classroom behavior.

Journal Article↗
PubMed1967

The reversal of phenylarsenoxide inhibition of keto acid oxidation in mitochondrial and bacterial suspensions by lipoic acid and other disulphides.

1. Inhibition of pyruvate oxidation in suspensions of Aerobacter aerogenes cells and of isolated mitochondria from rat heart and liver by phenylarsenoxide is prevented by an excess of lipoic acid, whereas inhibition due to certain bivalent cations is not. 2. In both systems inhibition persists when the bacteria and mitochondria are recovered and resuspended in fresh media in the absence of the inhibitor. Persistent inhibition due to preincubation with phenylarsenoxide, but not with the metal ions, is reversed by lipoic acid and by certain other disulphides. 3. 2,3-Dimercaptopropan-1-ol prevents the inhibition of pyruvate oxidation by phenylarsenoxide and by bivalent cations in both mitochondria and bacterial cells. 4. In aerobic suspensions of mitochondria and bacteria disulphides such as lipoic acid are reduced rapidly to dithiols. Reduction is inhibited by Co(2+), Ni(2+), Cd(2+) and Zn(2+), but not by phenylarsenoxide. 5. It is concluded that the inability of lipoic acid to prevent the action of the metal ions on pyruvate oxidation is due to the inhibition of its reduction to the effective dithiol.

Animals↗
PubMedDate not supplied

Presentation and outcome of 1107 cases of schistosomiasis from Africa diagnosed in a non-endemic country.

Schistosomiasis is found in a significant proportion of returning travellers and immigrants to Britain. This study is a retrospective review of 1107 consecutive cases of schistosomiasis from Africa diagnosed by microscopy or serology presenting to the Hospital for Tropical Diseases, London, UK. 50.4% of cases were asymptomatic. The most common symptom which resolved on treatment was tiredness. Serology was positive in 951 (86%), and ova seen in 45%. Urine dipstick testing was positive for blood in 21% and protein in 15%, with eosinophilia in 44%. In this population urine dipstick, full blood count and serology were all insufficient screening tools used alone. Among patients with full follow-up data 3 months or more after treatment with praziquantel, definite treatment failure occured in 4 of 271 (1.5%), restricting the analysis to those with ova seen at diagnosis. There was no significant difference in treatment failure between 1 and 3 days of treatment. Antibody level was the same or higher than at treatment in 55% of cases seen after about 3 months and 38% after 1 year, confirming it is probably of limited clinical use in detecting treatment failure.

Adult↗
PubMedDate not supplied

When a student commits suicide. A protocol for colleges of nursing.

Nursing faculty are rarely prepared for the suicide of a student. The authors discuss a protocol to be implemented when such an event occurs. It highlights the needs of faculty, fellow students, and significant others during this difficult period and guides the reader through the process of informing the faculty and students about the suicide, conducting support meetings, and managing the media. The protocol helps schools prevent disorganization and unnecessary legal jeopardy associated with such a crisis.

Crisis Intervention↗