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Biomedical subjects

D A Kennedy

Publications and source records attributed to D A Kennedy.

At least 19 recordsLinked to original sources
PubMed1997

Infiltrating ductal carcinoma of the vulva.

The eleventh case of primary infiltrating ductal carcinoma of the vulva is reported with a review of the literature. The infiltrating tumor is associated with an intraductal component as well as noninvolved mammary-like glandular tissue (ectopic breast tissue) and metastases to inguinal lymph nodes. Estrogen receptor and progesterone receptor immunohistochemical staining is negative utilizing the HSCORE method. The treatment regimen is patterned after approach to node-positive breast carcinoma.

Aged↗
PubMed1991

Posttraining D1 receptor blockade impairs odor conditioning in neonatal rats.

Rat pups that were exposed to a novel anise odor paired with tactile stimulation (stroking the skin with a paint brush) received injections of either saline or the dopamine D1 receptor antagonist (+/-)-SKF 83566 (0.1 mg/kg) before conditioning or immediately after conditioning. Animals that received the drug either before or after training showed less approach to the conditioned odor during the testing period 24 hr later than did animals that received the vehicle. Posttraining administration of the D2 receptor antagonist spiperone (0.1 mg/kg) did not affect subsequent approach to the conditioned odor, suggesting a selective effect of D1 receptor blockade. The impairment in learning by the administration of (+/-)-SKF 83566 before conditioning was reversed by the injection of the dopamine receptor agonist apomorphine (0.1 mg/kg) immediately after conditioning. Posttraining D1 receptor activation appears necessary for normal odor conditioning in rat pups.

2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-ben↗
PubMed1991

Reperfusion of ischemic skeletal muscle causes erythrocyte hemolysis and decreases subsequent oxidant-mediated lung injury.

A prior transient hindlimb ischemia/reperfusion (I/R) insult decreased acute lung injury in rats subsequently treated with cobra venom factor. I/R-mediated protection was associated with erythrocyte hemolysis, increased plasma catalase activity, and increased plasma hydrogen peroxide scavenging activity. In contrast, hindlimb I/R did not increase lung catalase activity, and large amounts of injected catalase were required to increase lung catalase activity. The results suggest that limited I/R in one organ can induce systemic processes that may decrease a subsequent O2 metabolite-mediated injury in another distant organ. The mechanism may involve release of catalase from hemolyzed erythrocytes at levels that are not sufficient to measurably increase total lung catalase activity.

Animals↗
PubMed1989

Protocol for the evaluation of automated blood coagulation instruments (coagulometers) for determination of the international normalised ratio.

Results of prothrombin time tests for the control of oral anticoagulant therapy, when using automated blood coagulation instruments (coagulometers), may not be the same as those obtained when using manual methods, and variation in coagulometer performance may affect clinical interpretation of data. The haematology advisory committee of the Institute of Medical Laboratory Sciences has recommended that coagulometers should be used for determination of prothrombin times only if it can be demonstrated that the results are valid when compared with those of a standardised manual method. A protocol for the evaluation of coagulometers, and details of the procedures, are given in this report, the main emphasis of which is on the assessment of instruments for determination of the International Normalised Ratio. Guidelines are also provided for the general use of machines of this type and for the assessment of safety. The principles of the protocol are applicable to other automated tests of blood coagulation.

Autoanalysis↗
PubMed1988

Needlestick injuries: mechanisms and control.

Consideration of a linear model for venepuncture and patterns that emerge from the literature can help to understand the occurrence of occupational needlestick injuries which are common in healthcare workers. A systematic approach can also help in evaluation of potential control measures and in cost-benefit analysis.

Accident Prevention↗
PubMed1988

Clinical laboratory environmental contamination: use of a fluorescence/bacterial tracer.

A "Centrifichem" centrifugal analyser was found using a double fluorescence/bacterial tracer method to be a source of airborne and surface contamination in the laboratory. The airborne contamination was controlled by a modification incorporating a filter. Ubiquitous surface contamination generally accompanied the processing of simulated patients' sera. Double tracer samples could be used in laboratories to assess the quality of hygiene practices in the same way as quality control samples are currently used to assess the quality of analytical performance. The findings indicated a lack of understanding of basic hygiene practices in the laboratory.

Air Pollutants↗
PubMed1986

Delayed-type hypersensitivity to Babesia microti-infected erythrocytes in mice.

Strong delayed-type hypersensitivity (DTH) to Babesia microti was elicited when intraerythrocytic parasites (IEP) were inoculated subcutaneously into the flank of normal mice 6 to 14 days before challenge in the ipsilateral footpad with 10(8) IEP. Intraperitoneal or intravenous administration of antigen did not sensitize mice for DTH. When challenge was given 21 days after immunization, the response was approximately half of the maximum and then rose again slowly over the next 3 weeks to levels that were not significantly different from those maximal values. The response was similar in seven strains of mice, regardless of sex. The response was classified as a true DTH reaction on the basis of kinetics, histology, and the transfer of responsiveness with immune T lymphocytes of the Ly 1+ phenotype, but not with serum. The reaction was specific for IEP since control groups given two injections of red blood cells from uninfected syngeneic mice (NRBC) or one injection of NRBC or sheep red blood cells (SRBC) and one of IEP never developed significant footpad swelling. Freed parasites obtained by osmotic rupture, density gradient sedimentation, and lethally irradiated IEP were also effective for elicitation of DTH. Anti-IEP DTH was expressed in a dose-dependent fashion with 10(6), 10(7), or 10(8) parasites sufficing for immunizing inoculum as long as 10(8) parasites were used as the challenge dose. Mice immunized and challenged with 10(8) lethally irradiated IEP (60 krad, 60Co), were protected against subsequent intraperitoneal challenge with 10(8) viable IEP. If mice were infected intraperitoneally with 10(8) IEP at any time between 21 days before immunization to 2 hr after challenge, their ability to respond to immunization and challenge was profoundly depressed. These data suggest that development of a strong anti-parasite DTH response can occur in parallel with resistance to infection, but is not a rapid sequela of bloodborne infection.

Animals↗
PubMed1986

Prostaglandin-mediated suppression of delayed-type hypersensitivity to infected erythrocytes during Babesia microti infection in mice.

The mechanism of suppression of delayed-type hypersensitivity (DTH) to intraerythrocytic Babesia microti which occurs during infection in mice was examined. The suppression was not specific for anti-parasite DTH; infected mice immunized and challenged with sheep red blood cells had a similar depression of anti-sheep red blood cell DTH. Sublethal or lethal irradiation did not significantly alter the suppression of the DTH response, and cyclophosphamide pretreatment of infected mice also had no effect on suppression. Multiple passive transfer experiments using serum or regional lymph node cells from immunized or infected and immunized (suppressed) donor animals failed to demonstrate any ability to transfer suppression of DTH. Adherent cells from the spleens or peritoneal exudates of suppressed mice, however, did significantly depress the ability of immunized mice to express a DTH response. The cells responsible for this suppression were Thy 1- and nonspecific esterase+. Treatment of suppressive cell populations with 10 micrograms/ml indomethacin for 24 hr in vitro abrogated their suppressive ability, and in vivo administration of indomethacin to suppressed mice also restored DTH to normal levels. By examining levels of prostaglandin E2 (PGE2) in supernates of cultured peritoneal exudate cells from immune or suppressed mice, it was shown that infected mice had peritoneal exudate cells which produced significantly more PGE2 than similar cells from immune mice. These data suggest that B. microti infection elicits synthesis of PGE2 by macrophage-like cells which results in suppression of DTH to parasite as well as heterologous antigens.

Animals↗
PubMed1986

Urinary excretion of cyclic nucleotides, creatinine prostaglandin E2 and thromboxane B2 from mice exposed to whole-body irradiation from an enhanced neutron field.

Urine volume and excretion of cyclic AMP, cyclic GMP, prostaglandin E2 (PGE2), thromboxane B2 (TxB2) and creatinine were evaluated as potential indicators of radiation damage in mice given 2-5 Gy to the whole body from an enhanced neutron field. In general, urinary cyclic AMP, cyclic GMP, creatinine and urine volumes were positively correlated across time postexposure, for each radiation dose. TxB2 levels positively correlated with urine volume and cyclic AMP excretion only in animals given 2.0 Gy. None of these parameters suggests their use as a prognostic indicator of the extent of radiation damage. Urinary excretion of PGE2 was negatively correlated with other urinary parameters. Biphasic increases in urinary PGE2 were also observed. The initial transient elevation 2-3 days postexposure was not correlated with the dose (2-5 Gy). The second elevation of PGE2 excretion occurred at 6-10 days. The magnitude of the latter increase suggests that urinary PGE2 excretion may be a useful indicator of whole-body or kidney exposure to neutron fields.

Animals↗
PubMed1986

British standard for human serum vitamin B12.

Seven laboratories took part in a collaborative study of an ampouled preparation of normal serum labelled 81/563. Each laboratory calibrated the preparation in terms of pure cyanocobalamin by use of Euglena assay. The inclusion of pernicious anaemia serum in the study and additional tests for safety and stability indicated that 81/563 would be a suitable standard for diagnostic testing. In 1985 the National Biological Standards Board established the preparation as the British Standard for Human Serum Vitamin B12 and, with the agreement of participants in the study, assigned it a potency of 320 picograms per ampoule.

Anemia, Pernicious↗
PubMed1985

Microcarriers in combination with enzyme immunofiltration and immunofluroescence for the detection of herpes simplex virus antigens in culture.

A microcarrier culture system in combination with enzyme immunofiltration with a herpes simplex virus (HSV) group monoclonal antibody was found to be as sensitive as immunofluorescence for the detection of HSV type 1 (HSV-1) in cell cultures and to give specific identification at the same time as the appearance of the cytopathic effect with very high infectious inocula and within 10 to 24 h of the appearance of the cytopathic effect with very high infectious inocula and within 10 to 24 h of the appearance of the cytopathic effect with low to high inocula. Multiplicities of infection from 10(-5) to 10(1) were tested at 8 to 96 h postinfection. When applied to the identification of HSV-1 and HSV-2 in cultures of clinical samples, the system detected HSV antigens in 50% of the samples after 2 days and in 100% of the samples after 3 days. With 2 ml of microcarrier suspension and with 50 to 300 microliter per sample, several portions are available for replicate and sequential sampling without destroying the culture. The system requires only that 2 X 10(5) microcarriers be added to the culture tube at the time or before it is seeded with cells, at an extra cost of 6 cents (U.S.) per tube and little extra labor.

Antigens, Viral↗
PubMed1984

Hepatitis B follow-up among Indochinese refugees.

During 1979 and 1980 the Department of National Health and Welfare carried out a survey and later routine testing to determine the prevalence of serologic markers of hepatitis B in Indochinese refugees entering Canada. Between March and July 1981 the hepatitis-B-marker status of 220 selected refugees in the Ottawa-Hull area was reassessed. Overall, 173 (79%) of the participants had the same serologic markers when retested, but in 47 (21%) the markers had changed. The most significant changes were the loss of antigenemia in 22% of those who had been HBsAg-positive and the appearance of evidence of infection in 18% of those who had been seronegative. Most of these changes occurred among persons under 30 years of age, especially females aged 10 to 19 years.

Adolescent↗
PubMed1984

Rapid differentiation of herpes simplex virus types 1 and 2 by cytopathic effect in BS-C-1 cells.

Conditions are defined under which herpes simplex virus (HSV) type 2 produces a characteristic cytopathic effect (c.p.e.) in African green monkey kidney (BS-C-1) cells. The BS-C-1 microplate c.p.e. test was simultaneously evaluated against immunological and biological marker procedures on 359 HSV strains. A BS-C-1 cell suspension was added to serial dilutions of HSV strains in Falcon Micro Test II plates and incubated at 36.5 degrees C in a 4% CO2 atmosphere. When the infected cultures were examined microscopically, distinctive pseudopod-like extensions were seen in cultures infected with type 2 strains but not seen when the infecting virus was type 1, forming the basis for a differentiating test. The test was 100% accurate in differentiating between HSV-1 and -2 on a one test per specimen basis. The method is simple, rapid and requires no specialized reagents.

Animals↗