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Biomedical subjects

M J Freeman

Publications and source records attributed to M J Freeman.

At least 19 recordsLinked to original sources

Hypotensive shock syndrome associated with acute Babesia canis infection in a dog.

A Doberman Pinscher contracted babesiosis after receiving a fresh blood transfusion from a Greyhound blood donor. Hypotensive shock syndrome was suspected on the basis of arterial hypotension, weakness, and pyrexia in the absence of detectable hemolysis and within hours of detection of low numbers of circulating Babesia canis organisms. Treatment with imidocarb dipropionate appears to have been effective in eliminating circulating B canis organisms and clinical disease. The blood donor, recently acquired from a race track, was healthy and lacked any abnormalities on initial laboratory evaluation; however, its serum antibody titer for B canis was > 1:5,000; B canis organisms were later identified on blood smears after the dog had been splenectomized and treated with corticosteroids at an immunosuppressive dosage. This case draws attention to a potential problem in current screening practices for infectious diseases of retired racing Greyhounds intended for use as blood donors.

Acute Disease

Repeated tests of intermale aggression in mice (Mus musculus) are influenced by housing and test conditions.

Young adult male Binghamton Heterogenous (HET) mice were housed either individually or in groups of four, in two-tiered cages for 11 days before their agonistic behavior was observed. Pairs of male mice were tested 3 min each day for 9 consecutive days. Agonistic behavior was observed in two-tiered cages in which there were either clean pine shavings or shavings soiled by young adult female HET mice. Housing and shaving conditions interactively influenced aggression observed over the course of testing. That is, when individually housed mice were tested with clean shavings and when group-housed mice were tested with female-soiled shavings, agonistic behavior decreased over days, but when isolated mice were tested in soiled shavings and when group-housed mice were tested in clean shavings, aggression increased over the course of the 9-day test period.

Aggression

Serological, pathological and cultural evaluations of swine infected experimentally with Mycoplasma flocculare.

Fourteen caesarean-derived, colostrum-deprived pigs and seven conventional swine were exposed to low passage, cloned, field isolates of Mycoplasma flocculare. Sera were collected at varying intervals postexposure (PE) and tested against M. flocculare and M. hyopneumoniae antigens in a semi-automated ELISA. Swine were killed six to 17 weeks PE and their lungs examined grossly for lesions and culturally for mycoplasmas. Pure cultures of M. flocculare were recovered from the lungs of 11 of 14 swine killed six to 12 weeks PE. Mycoplasmas were not isolated from the swine killed 15 to 17 weeks PE. Only one pig had gross lesions of pneumonia. Immunoassays revealed that swine were slow to seroconvert and titers (expressed in terms of optical density) were low. Three of 21 swine had antibodies to M. flocculare five weeks PE, five of 17 had seroconverted at seven to eight weeks and all surviving swine had antibodies to M. flocculare 76 days PE and beyond. Net optical density of positive sera was in the range of 0.201 to 0.412 (an optical density of 0.2 regarded as the breakpoint between negative and positive reactions in our ELISA). All of the sera were ELISA-negative when tested against M. hyopneumoniae antigen. This is regarded as a very significant finding. There has been concern that field sera might contain antibodies to M. flocculare and that such antibodies could render serodiagnostic tests for mycoplasmal pneumonia of swine nonspecific. Results of the present study suggest that swine infected with M. flocculare do not develop sufficient levels of antibodies to interfere with enzyme immunoassays for M. hyopneumoniae.

Animals

Cross-reactions between Mycoplasma hyopneumoniae and Mycoplasma flocculare--practical implications for the serodiagnosis of mycoplasmal pneumonia of swine.

Previous studies using hyperimmune antisera revealed significant serologic cross-reactions between Mycoplasma hyopneumoniae and M. flocculare. These findings, coupled with observations that M. flocculare infection may be widespread, indicated that antibodies to M. flocculare might be common in swine sera and thus cause nonspecific reactions in serodiagnostic tests for mycoplasmal pneumonia of swine (MPS). Information reported here indicates that this premise may be invalid. Twenty-one swine were infected experimentally with M. flocculare. Sera were collected every 2 weeks and tested against M. flocculare and M. hyopneumoniae antigens in an enzyme-linked immunosorbent assay (ELISA). Immunoassays against M. flocculare revealed that swine were slow to seroconvert, and that seroconversion was characterized by low titers. Significantly, none of the sera reacted with M. hyopneumoniae. M. hyopneumoniae reference antisera, and sera from swine naturally infected with M. hyopneumoniae and M. flocculare were also evaluated by an antibody inhibition procedure, i.e., sera were mixed with M. hyopneumoniae or M. flocculare antigen, incubated overnight and tested against M. hyopneumoniae antigen in the ELISA. Treatment with M. hyopneumoniae antigen markedly reduced or abolished seroreactivity, whereas treatment with M. flocculare antigen had little effect. These findings suggest that swine infected with M. flocculare usually do not develop sufficient levels of antibodies to detract from the specificity of the ELISA used to diagnose MPS.

Animals

A comparison of the acid-soluble polypeptides of five herpesviruses.

The polypeptides soluble in 0.25 M-HCl were extracted from the nuclei of BHK cells infected with herpes simplex virus type 1 or type 2 and separated by SDS-PAGE. Seventeen polypeptides were detectable in each extract of which 10 type 1 and nine type 2 polypeptides were reproducibly effectively extracted. In cells infected with bovine mammillitis virus, pseudorabies virus or equine herpesvirus type 1, at least 12, 13 and eight polypeptides respectively were acid-soluble. In addition to histones, three other cellular polypeptides were present in sizeable quantities in the acid extracts and could obscure other acid-soluble viral polypeptides. Possible relationships between some polypeptides of the five herpesviruses are discussed.

Animals

Evaluation of the indirect hemagglutination assay as a practical serodiagnostic test for mycoplasmal pneumonia of swine.

Sera from swine experimentally or naturally infected with Mycoplasma hyopneumoniae (the etiological agent of mycoplasmal pneumonia of swine, MPS) were tested by the indirect hemagglutination assay (IHA), the enzyme-linked immunosorbent assay (ELISA) and the complement fixation (CF) test. The IHA detected antibody at comparable times and levels to the other 2 serological tests following experimentally-induced infection. In the late antibody response (greater than or equal to 86 days post-infection), the ELISA titres were higher than either the IHA or the CF test. The IHA appeared least satisfactory when it was used to test sera from commercial swine herds. When 1000 sera were tested, the IHA was positive for only 30 (22%) of 135 sera which were positive by the ELISA and the CF test. The IHA titres were low; 20 of the 30 sera had a titre of only 10. The end-points for the IHA were difficult to read for sera of this low titre. The relationship between positive IHA results for the herd sera obtained at necropsy, and the occurrence of gross or microscopic lesions typical of MPS was poor (41 and 50% agreement, respectively). An agreement of 39% was noted between positive IHA results and the localization of mycoplasmal antigens by an indirect immunofluorescence (IIF) test. However, IHA results correlated significantly (P less than 0.05) with gross and microscopic lesions, but not with the IIF test. No significant correlation was noted between the IHA (or the other 2 serologic tests) and the cultural isolation of M. hyopneumoniae or M. flocculare. On the basis of these results, the IHA appears to have limited promise as a practical test for the diagnosis of MPS in commercial swine herds because of the low titres observed, poor correlation of the IHA and other indicators of MPS, the necessarily subjective determination of end-points, and other inherent technical limitations of the test.

Animals

Serological cross-reactivity of porcine reference antisera to Mycoplasma hyopneumoniae, M. flocculare, M. hyorhinis and M. hyosynoviae indicated by the enzyme-linked immunosorbent assay, complement fixation and indirect hemagglutination tests.

The enzyme-linked immunosorbent assay (ELISA) indicated significant cross-reactivity between the antigens of Mycoplasma hyopneumoniae ( HyoP ) and M. flocculare (Floc), another porcine mycoplasma of wide distribution but uncertain pathogenic significance, when porcine antisera of each specificity were tested against HyoP antigen. The titers of the anti-Floc sera ranged from threefold to 13-fold less than the titer of the anti- HyoP reference serum at different times after immunization. These values ranged from onefold less than to fourfold greater than the minimal positive titer of 80. The antisera to the other porcine mycoplasmal antigens [i.e. M. hyorhinis ( HyoR ) and M. hyosynoviae ( HyoS )] reacted less strongly to HyoP antigen but titers only slightly less than to slightly greater than the minimal positive titer were noted for some sera. Cross-reactivity was also detected by the complement fixation test, although the titers for this test were generally lower than for the ELISA, presumably reflecting lower sensitivity of the complement fixation test. Positive indirect hemagglutination titers to HyoP antigen were also observed for both anti-Floc sera obtained at one or more times during the immune response. With two exceptions (one anti- HyoR serum with a complement fixation titer of 16 and one anti- HyoR serum with an indirect hemagglutination titer of 10), none of the anti- HyoR or anti- HyoS sera had detectable indirect hemagglutination or complement fixation titers to HyoP antigen at any time after immunization. The levels of cross-reactivity detected by the complement fixation test and indirect hemagglutination and, especially, the ELISA would be of significance for the development of any practical sero-diagnostic test for mycoplasmal pneumonia of swine.

Animals

Evaluation of criteria for the postmortem diagnosis of mycoplasmal pneumonia of swine.

Ten swine from each of five herds believed to be affected with mycoplasmal pneumonia of swine and ten swine from each of five herds believed to be mycoplasmal pneumonia-free were selected for postmortem study. Lungs from the 100 swine were examined; grossly and microscopically for lesions typical of mycoplasmal pneumonia of swine and culturally and by an indirect immunofluorescent procedure for the presence of Mycoplasma hyopneumoniae. Nineteen of the lungs had both gross and microscopic lesions typical of mycoplasmal pneumonia of swine and 13 (68%) of these were infected, i.e. were culturally and/or indirect immunofluorescent positive. Absence of gross lesions did not prove freedom from mycoplasmal pneumonia, 14 of 73 (19%) grossly normal lungs were found to be infected with M. hyopneumoniae. Comparison of the indirect immunofluorescent and cultural examination, as methods of diagnosing mycoplasma pneumonia, revealed that neither procedure alone was reliable in the case of negative results. Ten lungs were indirect immunofluorescent negative and culturally positive and seven were culturally negative and indirect immunofluorescent positive (11 lungs were positive by both procedures). It was concluded that a definitive diagnosis of mycoplasmal pneumonia of swine requires that M. hyopneumoniae be visualized in indirect immunofluorescent stained lung sections or that it be recovered culturally.

Animals

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

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

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

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

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

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

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

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