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Biomedical subjects

P Willson

Publications and source records attributed to P Willson.

At least 19 recordsLinked to original sources
PubMed2003

Induction of protective immunity in pigs after immunisation with CpG oligodeoxynucleotides formulated in a lipid-based delivery system (Biphasix).

A large number of studies demonstrated the immunostimulatory effects of CpG oligonucleotides (ODN), particularly in mice. In the present study, we evaluated the ability of lipid-based delivery systems to enhance the adjuvant effect of CpG-ODN and protect against infection in a porcine pleuropneumonia model. Increased levels of OmlA-specific antibody were detected in animals immunised with OmlA and CpG-ODN formulated in the delivery system Biphasix-vaccine targeting adjuvant (VTA), compared to pigs immunised with VTA without CpG-ODN or CpG-ODN alone. In addition, the responses induced by VTA/CpG formulation were similar to those induced by the commercial adjuvant VSA; however, VTA formulations caused significantly less tissue damage than VSA.

Animals↗
PubMed2002

CpG-containing oligodeoxynucleotides augment and switch the immune responses of cattle to bovine herpesvirus-1 glycoprotein D.

The adjuvanticity of a synthetic oligodeoxynucleotide containing unmethylated CpG motifs (CpG ODN) was determined in cattle. Calves were immunized with a truncated secreted version of glycoprotein D (tgD) of bovine herpes virus-1 (BHV-1) formulated with alum, CpG ODN, or a combination of both. BHV-1 tgD formulated with CpG ODN or with alum and CpG ODN induced a stronger and more balanced immune response than tgD in alum. This level of immunity was of sufficient magnitude to minimize weight loss and significantly reduce the duration of virus shedding after intranasal viral challenge. Local tissue reactions generated by CpG ODN were very mild and transient, whereas reactions induced by alum or a combination of CpG ODN and alum were moderate in severity and duration. These data demonstrate that CpG ODN causes minimal injection site reactions and yet acts as an effective adjuvant in cattle.

Adjuvants, Immunologic↗
PubMed2002

Changes in the leucocyte subpopulations of the palatine tonsillar crypt epithelium of pigs in response to Streptococcus suis type 2 infection.

The tonsils are portal of entry and a site of multiplication and persistence for a variety of pathogens, including Streptococcus suis (S. suis), which is a common cause of meningitis, septicemia and arthritis in pigs. Understanding the early changes that occur in the first barrier of the tonsil, i.e. the crypt epithelium, in response to S. suis infection is critical in clarifying the pathogenesis of this disease and for the future development of efficient methods of mucosal vaccination. In this study, we investigated the early changes, from 18 to 72 h, that occur in leucocyte subpopulations of the crypt epithelium of the palatine tonsils of 3-week-old pigs in response to S. suis type 2 infection. Monoclonal antibodies against leucocyte markers CD3, CD4, CD8, gammadelta T cell receptor, lambda-immunoglobulin light-chain, myeloid cells, and major histocompatibility complex class II molecule (MHC-II) were used in an avidin-biotin immunoperoxidase technique. An increase in the number of lambda-immunoglobulin light-chain positive cells (B cell subset) was noticed in crypts of S. suis-infected animals from 18 h after infection onwards. This increase was significant at 18 and 48 h after infection. The number of CD4 and CD8 cells was greater from 18 h onwards, with a significant increase at 24 and 72 h post-infection. No significant difference in numbers of CD3, gammadelta T cell receptor and MHC-II positive cells was detected in the crypts of infected animals compared to controls. Macrophages, neutrophils and crypt epithelial cells stained positively with the myeloid marker, and the area of crypt epithelium positive for this marker was increased in the crypts of infected animals, with a significant difference detected at 24 and 72 h after infection. These results suggest that there is participation of the innate immunity in the early phase of S. suis infection, represented by neutrophils, macrophages and likely epithelial cells, and that there is a potential for the initiation of both humoral and cellular responses against S. suis within the crypt epithelium of the palatine tonsil.

Animals↗
PubMed2001

Suppository-mediated DNA immunization induces mucosal immunity against bovine herpesvirus-1 in cattle.

Mucosal surfaces are the primary sites for the transmission of infectious agents including viruses, so effective vaccines generally should induce mucosal immunity. Furthermore, noninvasive delivery is desirable because of the ease of application, the high degree of patient compliance, and the improved safety for patients and clinicians due to the elimination of needles. Unfortunately, most of the conventional vaccines are parenterally administered and result in systemic rather than mucosal immunity. Here we present the first report of mucosal immunity by noninvasive DNA immunization in a target species. As an approach to induce mucosal immunity against bovine herpesvirus-1, cows were immunized intravaginally with suppositories containing plasmid coding for glycoprotein D. Serum IgG, as well as IgA both in the serum and in the nasal fluids, were detected, which supports the contention of a common mucosal immune system. This level of immunity was of sufficient magnitude to minimize weight loss and significantly reduce the duration of virus shedding after intranasal viral challenge, which demonstrates the efficacy of suppository-based administration of DNA vaccines to target species. As this is a very practical method of delivery, it has great potential to be applied as vaccine or therapy in a variety of species.

Administration, Intravaginal↗
PubMed2001

Women in danger: intimate partner violence experienced by women who qualify and do not qualify for a protective order.

Not all women who apply qualify for a civil protective order. This study compares the type and severity of violence reported by women who qualified with that experienced by women who did not qualify. Ninety women seeking a protective order against a male intimate were interviewed. Findings indicated that 28% of women applying for a protective order did not qualify primarily because of cohabitation requirements or childbearing status. Actual and threatened violence was measured with the 46-item Severity of Violence Against Women Scale. A 17-item questionnaire measured stalking behavior. Levels of reported violence for the preceding 3 months were measured for the two groups. The symbolic threat behavior only of throwing, smashing, or breaking an object was significantly higher for qualifying women. The physical abuse behavior only of being pushed, shoved, or pulled was significantly higher. None of the stalking behaviors were significantly different. Data are urgently needed that document the barriers to abused women receiving protective orders, the relevancy of qualifying criteria, and the effectiveness of protective orders issued.

Adolescent↗
PubMed2001

Bacterial expression of an immunologically reactive PCV2 ORF2 fusion protein.

The entire coding region of open reading frame 2 (ORF2) of porcine circovirus 2 (PCV2) was linked to the 3'-end of the maltose-binding protein (MBP)-His(8)-tag gene. The fusion protein was expressed as soluble form after induction by isopropylthio-beta-d-galactoside. MBP-His(8)-ORF2 was purified to homogeneity by immobilized metal affinity chromatography based on the interaction of the polyhistidine-tag with metal ions. Expression could represent 1% of the total protein in Escherichia coli, allowing approximately 1 mg of highly purified protein to be obtained per liter of bacterial culture. The fusion protein was recognized in Western blot by anti-PCV2 polyclonal antibody and swine sera with PCV2 infection. In addition, rabbit polyclonal antibody raised against purified MBP-His(8)-ORF2 fusion protein reacted with the ORF2 protein in immunoprecipitation. The availability of this fusion protein should permit a thorough study of prevalence of PCV2 infection in large-scale serological studies of field samples.

ATP-Binding Cassette Transporters↗
PubMed2001

Priming by DNA immunization augments T-cell responses induced by modified live bovine herpesvirus vaccine.

DNA vaccines have several advantages over conventional vaccines. One of the most important characteristics is the presentation of antigen via both MHC class I and class II receptors. Although this generally results in strong T-cell responses, antibody production and protection achieved by DNA immunization are unfortunately not always adequate. In contrast, modified live virus (MLV) vaccines usually induce adequate antibody and moderate cellular responses, whereas killed vaccines tend to elicit weak immune responses in general. A DNA prime-MLV boost regimen should result in enhanced cellular immunity and possibly improved antibody production. To test this hypothesis, plasmids encoding bovine herpesvirus-1 (BHV-1) glycoproteins B and D were delivered by gene gun to the genital mucosa of cattle prior to immunization with modified live BHV-1 vaccine. The immune responses induced were compared to those of an MLV-vaccinated group and a negative control group. Although significantly enhanced T-cell responses were induced by priming with the DNA vaccine, there was no increase in antibody titres. Similar levels of protection were induced by the MLV vaccine alone and the DNA prime and MLV boost regimen, which suggests that there is no correlation between the induction of T-cell responses and protection from BHV-1 challenge.

Animals↗
PubMed2001

Primary healthcare provider's lost opportunity to help abused women.

PURPOSE: To determine how often primary care providers have the opportunity to assess and intervene for intimate partner violence (IPV) in a population of women who are known to be experiencing IPV. DATA SOURCES: A convenience sample of 149 abused women presenting to the justice system for protection orders or to file assault charges against in intimate partner were interviewed about the date and reason for her last healthcare visit, whether she had been screened for IPV, and the presence of selected conditions, medication use, and hospitalizations. CONCLUSIONS: Although 86% (n = 128) of the women had sought healthcare services within the previous year, only 24% (n = 36) had been assessed for IPV. IMPLICATIONS FOR PRACTICE: Abused women use healthcare services at higher rates and have more health conditions than non-abused women. Despite recommendations of professional organizations, health providers have low rates of screening for IPV. Universal screening for IPV by nurse practitioners could substantially interrupt ongoing abuse.

Adult↗
PubMed2001

Prevalence of hepatitis E virus antibodies in Canadian swine herds and identification of a novel variant of swine hepatitis E virus.

Swine hepatitis E virus is a newly identified potentially zoonotic virus from pigs of particular concern for possible direct transmission to a human xenotransplant recipient by organ transplantation. In the present study, prevalence of serum antibodies to hepatitis E virus was examined in Canadian swine herds. A total of 998 serum samples collected from 6-month-old healthy slaughter hogs were examined by enzyme immunoassay and Western blot analysis for antibodies to the recombinant open reading frame 3 (ORF3) protein of hepatitis E virus expressed in Escherichia coli. These samples represented more than 80 different swine production units from five major swine-producing provinces across Canada. From this study, 594 samples (59.4%) were found to be positive for hepatitis E virus antibody. The seroprevalence was higher in Quebec (88.8%) and Ontario (80.1%) than in Alberta and Saskatchewan (38.3%). By PCR using a pair of oligonucleotide primers deduced from the ORF2 sequence of human hepatitis E virus, a specific hepatitis E virus sequence was recovered from feces of pigs. The nucleotide sequence identity between the U.S. swine hepatitis E virus and the Canadian isolate (SK3) was only 85.8%, suggesting that genotypic variations may exist in swine hepatitis E virus in North America. Among 165 serum samples collected from humans in Saskatchewan, 2.4% were found to be positive for antibodies to the hepatitis E virus ORF3 protein. Our data indicate that hepatitis E virus is highly prevalent in commercial swine populations in Canada and support the suggestion that the swine hepatitis E virus may be an important zoonotic agent for humans.

Animals↗
PubMed2001

Referring abused women: does police assistance decrease abuse?

To evaluate if abused women's use of the police reduced further violence experienced, 90 abused women were interviewed at a large urban police department and followed for 6 months. Frequency and severity of violence as well as danger of homicide were measured before and at 3 and 6 months after women sought police help. Women seeking police help had significantly reduced threats of abuse (F = 124.62, df = 2,81; p < .0005), actual abuse (F = 90.11, df = 2,81; p < .0005), and danger of being killed (F = 188.69, df = 2,81; p < .0005) by her intimate partner. Bonferroni post hoc tests showed that significantly fewer threats of abuse, physical abusive acts, and risk indicators for homicide had occurred from prefiling to 3 months (p <.0005) and prefiling to 6 months (p <.0005). The data indicate that referring abused women to the police is an appropriate intervention.

Adolescent↗
PubMed2000

Quantitative, competitive PCR analysis of porcine circovirus DNA in serum from pigs with postweaning multisystemic wasting syndrome.

A competitive PCR (cPCR) assay was developed for monitoring porcine circovirus (PCV) DNA in serum samples from piglets. The cPCR was based on competitive coamplification of a 502- or 506-bp region of the PCV type 1 (PCV1) or PCV2 ORF2, respectively, with a known concentration of competitor DNA, which produced a 761- or 765-bp fragment, respectively. The cPCR was validated by quantification of a known amount of PCV wild-type plasmids. We also used this technique to determine PCV genome copy numbers in infected cells. Furthermore, we measured PCV DNA loads in clinical samples. More than 50% of clinically healthy piglets could harbor both types of PCV. While PCV1 was detected in only 3 of 16 pigs with postweaning multisystemic wasting syndrome (PMWS), all the sick piglets contained PCV2. A comparison of the PCV2 DNA loads of healthy and sick animals revealed a significant difference, indicating that the development of PMWS may require a certain amount of PCV2.

Animals↗
PubMed2000

Gene gun-mediated DNA immunization primes development of mucosal immunity against bovine herpesvirus 1 in cattle.

Vaccination by a mucosal route is an excellent approach to the control of mucosally acquired infections. Several reports on rodents suggest that DNA vaccines can be used to achieve mucosal immunity when applied to mucosal tissues. However, with the exception of one study with pigs and another with horses, there is no information on mucosal DNA immunization of the natural host. In this study, the potential of inducing mucosal immunity in cattle by immunization with a DNA vaccine was demonstrated. Cattle were immunized with a plasmid encoding bovine herpesvirus 1 (BHV-1) glycoprotein B, which was delivered with a gene gun either intradermally or intravulvomucosally. Intravulvomucosal DNA immunization induced strong cellular immune responses and primed humoral immune responses. This was evident after BHV-1 challenge when high levels of both immunoglobulin G (IgG) and IgA were detected. Intradermal delivery resulted in lower levels of immunity than mucosal immunization. To determine whether the differences between the immune responses induced by intravulvomucosal and intradermal immunizations might be due to the efficacy of antigen presentation, the distributions of antigen and Langerhans cells in the skin and mucosa were compared. After intravulvomucosal delivery, antigen was expressed early and throughout the mucosa, but after intradermal administration, antigen expression occurred later and superficially in the skin. Furthermore, Langerhans cells were widely distributed in the mucosal epithelium but found primarily in the basal layers of the epidermis of the skin. Collectively, these observations may account for the stronger immune response induced by mucosal administration.

Animals↗
PubMed2000

Positive human health effects of wearing a respirator in a swine barn.

STUDY OBJECTIVES: A study was conducted to evaluate the acute health effects of wearing an N-95 disposable respirator in a swine confinement facility. DESIGN: A crossover trial design was used in the study. SETTING: The study was carried out at the research facilities of the Centre for Agricultural Medicine, the Royal University Hospital, and the Prairie Swine Centre Inc, Saskatoon, Saskatchewan, Canada. PARTICIPANTS: Twenty-one nonsmoking healthy male subjects with no previous swine barn exposure participated in the study. INTERVENTIONS: The subjects participated in a laboratory session (baseline day), a 4-h exposure in a traditional swine room wearing the respirator (intervention day), and a 4-hour exposure in a traditional swine room without a respirator (nonintervention day). MEASUREMENTS: Lung function, methacholine challenge tests, blood counts, nasal lavage, and cytokines in serum and nasal lavage fluid. RESULTS: Mean (+/- SE) shift change in FEV(1), from preexposure to postexposure, was highest on nonintervention day (-8.1+/-1.01%) and was significantly different from intervention day (0.32+/-0.62%; p<0.0001) and baseline day (1.57+/-0.51%; p<0.0001). Similar patterns were observed in the mean values of the provocative concentration of a substance (methacholine) causing a 20% fall in FEV(1) (nonintervention day, 130.4+/-36.9 mg/mL; intervention day, 242.0+/-38.0 mg/mL; and baseline day, 328.0 mg/mL +/-34.1 mg/mL). Significant increases in serum neutrophil levels and nasal cell counts were observed on the nonintervention day in comparison to the baseline and intervention days. Significant increases also were found in the levels of cytokines interleukin (IL)-6 and IL-8 in nasal lavage fluid and in the levels of IL-6 in serum for the nonintervention day in comparison to the other 2 days. CONCLUSIONS: The results demonstrate that an N-95 disposable respirator can help to significantly reduce acute negative health effects in subjects not previously exposed to a swine barn environment.

Adolescent↗
PubMed2000

Indicators of intimate partner violence in women's employment: implications for workplace action.

The study examined the indicators and consequences of intimate partner violence on women's employment and associated types and levels of violence. Interviews were conducted with a consecutive sample of 90 women seeking a protective order. Actual and threatened violence was measured with the Severity of Violence Against Women Scales (46 items). Eight questions were asked about type of harassment experienced at the worksite. The results found most of the abused women had been employed at one time (87%) and had also experienced harassment from an intimate partner related to their work (89%). Findings indicated lost productivity and reduced performance. The researchers concluded poor work performance, tardiness, and absenteeism may indicate an employee is suffering from intimate partner violence.

Absenteeism↗
PubMed1999

Building community for the long-term: an intergenerational commitment.

Intergenerational visitation programs have demonstrated advantages for the young and old, but few programs last more than a year or two. Weaving long-term intergenerational programs into the fabric of both school curricula and community cultural life was the goal of a project launched in 1988 in Phoenix, Arizona. Classrooms of children visit weekly or biweekly with nearby nursing home residents, developing friendships while pursuing educational activities. Carefully planned and widespread community support through board participation, donations, and publicity has allowed the program to continue to expand, while the budget has decreased. Materials are available which facilitate program replication.

Aged↗
PubMed1998

Isolation of circovirus from lesions of pigs with postweaning multisystemic wasting syndrome.

Postweaning multisystemic wasting syndrome (PMWS), an apparently new disease, has been recognized in swine herds in western Canada. Young pigs with this disease have progressive weight loss, tachypnea, dyspnea, and jaundice, accompanied by interstitial pneumonia, lymphadenopathy, hepatitis, and nephritis. We examined more than 400 pigs from more than 70 herds in Alberta, Saskatchewan, and Manitoba with cases of PMWS. A small virus was isolated from a range of tissues from 8 of 8 affected pigs examined. The agent was identified as a circovirus-like virus using electron microscopy, immunohistochemical staining with porcine and rabbit immune serum, and in situ hybridization. Immunohistochemical examination of tissues from more than 100 affected pigs has revealed widespread viral antigen, often contained in circovirus-like inclusion bodies, in lesions from numerous organs. Although Koch's postulates remain to be fulfilled, these results demonstrate a high degree of association between the presence of the circovirus-like virus and PMWS in affected swine.

Alberta↗
PubMed1996

Bacterial and fungal flora of dust deposits in a pig building.

OBJECTIVE: The purpose of the study was to investigate the bacterial and fungal flora of dust deposits in a newly built pig grower finisher building. Viable bacterial counts and microbial species found in a barn which had never housed pigs were compared with those in a barn housing 144 pigs. METHODS: The quantitative streak plate method was used to measure viable bacterial counts on nutrient agar or sheep blood agar. Viable bacterial counts of the dust deposits were expressed as the number of colony forming units (CFUs)/mg of dust. Gram positive cocci and Gram negative bacilli were identified by an automated system. Identifications with a confidence interval > 90% were accepted at the species level. Fungi were identified to the genus level with slide culture preparations on cereal agar. RESULTS: The lowest viable bacterial count (4.8 x 10(4)/mg of dust) was found in the barn with no pigs. In the barn with pigs the highest viable bacterial count (2.1 x 10(6)/mg of dust) was in dust from the top of a partition close to pig activity. Six species of bacteria or fungi were found in dust from the room with no pigs, whereas 22 different microorganisms were detected in dust from the room with pigs. With the exception of Enterobacter agglomerans no other species of the family Enterobacteriaceae was found in dust deposits in this new pig building. Twelve species of Gram positive bacteria were found in the room housing pigs. CONCLUSIONS: The pig is not only a source but also a disperser of airborne bacteria in pig buildings. Speciation of the microbial flora in dust from the pig building suggests that many of the microorganisms were either of human or environmental origin. Nevertheless as some of these microorganisms are known opportunistic pathogens or allergens and because of the documented increased incidence of chronic respiratory symptoms in pig workers, precautions to reduce inhalation of microbial or dust particles by pig workers seem prudent.

Animals↗