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Biomedical subjects

M J Freeman

Publications and source records attributed to M J Freeman.

At least 37 records · Page 2Linked to original sources
PubMed1983

Comparison of manually performed Microtiter plate and semiautomated (cuvette) indirect enzyme-linked immunosorbent assays for the serodiagnosis of mycoplasmal pneumonia of swine.

Standardized enzyme-linked immunosorbent assays for the serodiagnosis of mycoplasmal pneumonia of swine were developed, using the traditional Microtiter plate method and a method based on semiautomated processor-analyzer instrumentation. The results of the 2 procedures were not significantly different when the titers of positive and negative anti-Mycoplasma hyopneumoniae standard reference sera were determined in triplicate in 3 separate experiments. Although both methods yielded reproducible results, the instrument-assisted enzyme-linked immunosorbent assay would be preferable if large numbers of samples are to be tested.

Animals↗
PubMed1983

Comparison of the enzyme-linked immunosorbent assay and the indirect hemagglutination and complement fixation tests for detecting antibodies to Mycoplasma hyopneumoniae.

Caesarean-derived, colostrum-deprived swine were exposed to a broth culture of a low passage field isolate of Mycoplasma hyopneumoniae by intranasal inoculation. The intranasal-inoculated swine subsequently were commingled with their litter-mates to effect transmission via contact-exposure. Sera were collected from the swine at two to four week intervals for approximately one year postexposure and evaluated by the enzyme-linked immunosorbent assay (ELISA), indirect hemagglutination and complement fixation tests. The intranasal-exposed swine seroconverted earlier, developed higher titers and remained indirect hemagglutination and complement fixation positive longer than the contact-exposed swine. It was concluded that the antibody response of intranasal-exposed swine was artificially high and that sera from such swine were not suitable for evaluating the sensitivity of mycoplasmal pneumonia of swine serodiagnostic tests. The indirect hemagglutination test was relatively insensitive and technically cumbersome and the least promising as a practical field test. The complement fixation test appeared to be slightly more sensitive in detecting early antibody production (especially in contact-exposed swine) but it was the least sensitive in detecting late antibodies. The ELISA was generally the most sensitive procedure. Individual high ELISA titers were from ten to 32 times greater than maximum complement fixation and indirect hemagglutination titers. The most striking difference among the three tests was the persistence of high ELISA titers late in the study. All swine were ELISA positive at necropsy approximately one year postexposure despite the fact that lungs were devoid of lesions and culturally and immunofluorescent negative for M. hyopneumoniae.

Animals↗
PubMed1982

DNA-binding properties of a herpes simplex virus immediate early protein.

The herpes simplex virus alpha, or immediate early, protein ICP4 has been shown to be central to the control of the early stages of virus replication. The detailed mechanism of this control is unknown. In this communication we show that purified ICP4 was unable to bind to DNA even though the protein was capable of such activity in a crude extract. Addition of either infected- or uninfected-cell extracts to the purified protein restored its DNA-binding activity. These results suggest that ICP4 binds to DNA only via a component of uninfected cells.

DNA Helicases↗
PubMed1979

Effects of age on cellular immune responses in BALB/cJ mice: increase in antibody-dependent T lymphocyte mediated cytotoxicity.

Two in vitro cell-mediated immune (CMI) responses of splenic lymphocytes of BALB/cJ mice of various ages (1.25, 2.5, 4, 10.5 and 30 months) were examined. These were the antibody-dependent lymphocyte-mediated cytotoxicity (ADLMC) responses, mediated by the K cell subclass to T lymphocytes, and phytohemagglutinin (PHA) induced mitogenesis, mediated by the theta positive T lymphocytes. ADLMC responses increased with age, culminated at 10.5 months, then slowly declined. Lymphocytes of young mice (2.5 or 4 months of age) were significantly more responsive to PHA than lymphocytes of mature (10.5 months) or aged adults (30 months) (p less than 0.01), indicating progressive suppression of this type of CMI response with age, as observed previously. The difference in time of maturation and extent of suppression of ADLMC and PHA responses was not influenced by changes in numbers of specific effector cells, since percentages of these did not change with age (as measured by immunofluorescence and rosetting techniques). The increase with age of ADLMC responses may be due to deregulation of earlier suppressor activity which allows the K cell to be fully responsive, but other mechanisms may be involved.

Aging↗
PubMed1979

DermRx. An experiment in computerizing information on dermatologic therapy.

The Task Force for Creating a Biomedical Communications System for Dermatology was commissioned by the American Academy of Dermatology to develop an experimental segment of a computerized data bank on dermatologic therapy. The Task Force has completed such a "first generation" system and has named it DermRx. Its data bank carries the following information on each entry: the name of the disease; topical, systemic, physical, and other kinds of treatment; caveats; references to the literature; and the date and reviewer(s). The DermLit and DermRx programs are two components of a projected broader concept of an eventual comprehensive Biomedical Communications System for Dermatology. Such a system is envisaged as a means of making available to dermatologists diverse data relevant to practice, teaching, research, and business aspects of the specialty. At the moment, access to the stored information on dermatologic literature and therapy is by telephone call to, or by correspondence with, the central computer facility at Northwestern University. Eventually it is projected to be accessible by dedicated microcomputers housed in the physician's office. This preliminary report on DermRx is presented to review the progress of the project to date and to elicit comment upon its structure and value.

Dermatology↗
PubMed1978

Histiocytic medullary reticulosis presenting as Mucha-Habermann disease.

Histiocytic medullary reticulosis (HMR) is a rare, progressive, fatal reticuleondothelial proliferative disorder. It was diagnosed in a 10-year-old boy who had pityriasis lichenoides et varioliformis acuta of Mucha-Haberman which was controlled by dapsone for 2 years. One month after cessation of dapsone therapy, cutaneous tumors associated with fever, lymphadenopathy, and hepatosplenomegaly developed. Tissue biopsy specimens of skin, liver, spleen, lymph nodes, and a bone marrow aspirate demonstrated histiocytic erythrophagocytosis and atypical histiocytosis compatible with HMR. A rapidly progressing, fatal course followed despite intensive chemotherapy.

Child↗
PubMed1977

Glycolipid-bound sialic acid in serum: increased levels in mice and humans bearing mammary carcinomas.

In mice bearing transplantable mammary carcinomas, serum levels of sialic acid-containing glycolipids were elevated 2.5-fold in pooled serum samples from which gangliosides were purified by column chromatography. A method is also described by which ganglioside content was estimated on as little as 1.0 ml of whole blood to permit studies with individual tumor-bearing mice and age- and litter-matched controls. Using this method, we observed similar elevations in ganglioside levels that were independent of age and sex of the animal and appeared in advance of palpable tumors. Following excision of the tumors, the glycolipid sialic acid values dropped below control levels and remained there. Serum sialic acid of the glycolipid fraction was elevated nearly 2-fold in human carcinoma patients and appeared to decline after surgery.

Animals↗
PubMed1977

Skin diseases of football and wrestling participants.

This discussion has highlighted some of the cutaneous disorders that are found in football and wrestling participants in an exaggerated form. These disorders may occur in any person, of course, and are not limited to football or wrestling participants. Also, football and wrestling participants may have any cutaneous disorder; their disorders are not limited to those mentioned in this review. The dermatologist should be alert to contagous disorders in these participants, especially because of the close contact their activities necessitate and the potential epidemic spread of these disorders. One must also be alert to the possibility that a condition may be masked by the minor trauma of the sport. It is re-emphasized that these disorders are exaggerated because of the increased perspiration, heat, friction, secretion of fatty acids, body contact, special gear, climatic conditions, and trauma. Fortunately, the participants are normally healthy individuals who respond quickly to the appropriate therapy.

Acne Vulgaris↗
PubMed1972

Studies on type C influenza virus in the chick embryo.

The effect of varying conditions of inoculation and incubation on the growth of type C influenza virus in the allantoic cavity of the developing chick embryo were investigated. It was found that the highest yields of both virus haemagglutinin and infectious virus were obtained following the inoculation of chick embryos at 8 days with subsequent incubation at 32 degrees C. Using the chick embryo allantoic cavity for titration of infectious virus, growth curves of allantoically propagated virus under varying inoculation and incubation conditions were determined.

Animals↗
PubMed1971

Properties of a cold hemagglutin in associated with leptospiral hemolytic anemia of sheep.

The cold hemagglutinin which appears after leptospiral infection of sheep was isolated consistently from the plasma by absorption to autologous erythrocyte stroma at 4 C and subsequent elution at 25 C. Immunoelectrophoretic tests disclosed that the purified preparations consisted primarily of a single detectable component with the electrophoretic, positional, and antigenic characteristics of ovine immunoglobulin M. The properties of the cold hemagglutinin included a rapid sedimentation rate, elution in the leading peak from G-200 Sephadex, high anionic-binding capacity, and rapid electrophoretic mobility. Thus, these methods also supported the identification of the cold hemagglutinin as a homogeneous protein with properties like immunoglobulin M. The occurrence of the cold hemagglutinin after the phase of leptospiremia and concurrent to the onset of hemolytic anemia suggests that this antibody may play a significant role in the genesis of leptospiral acquired hemolytic anemia.

Journal Article↗