Contacts posing risks of disease introduction in swine breeding herds in Quebec, Canada: Is the frequency of contacts associated with biosecurity measures?

The introduction of pathogens into swine breeding herds can occur through a variety of contacts involving people, animals, vehicle or various supplies. Appropriate biosecurity is critical to mitigate these risks. A retrospective study was conducted to describe contacts with swine breeding sites over a one-month period and to evaluate their association with biosecurity measures and site characteristics. As part of a larger project, sites which had a recent porcine reproductive and respiratory syndrome virus introduction were selected. A questionnaire, logbooks and pig traceability system were used for collecting data relative to persons or supplies entering the breeding unit, live pig transportation, service vehicles, other animal species, neighboring pig sites and manure spreading around the site. The 84 sites investigated had a median sow inventory of 675. A median of 4 farm staff and 2 visitors entered the breeding unit at least once over the one-month period. A total of 73 sites (87%) received visitor(s), mostly from maintenance and technical services. All sites received at least 3 supply deliveries (median of 8) including semen (99% of sites), small material and/or drugs (98% of sites), bags (87% of sites), and/or equipment (61% of sites). Live pig movements were observed in all sites, with a median number of 5 truck entries on the site or exits from the site. For feed mill, rendering and propane trucks, at least one entry was noted in ≥ 61% of sites. For all service vehicle categories except feed mill and manure vacuum trucks, a single service provider was involved in each site. Dogs and cats were banned from all sites, but wild birds were observed in 8% of sites. Manure spreading within a 100 m radius of pig units was noted in 10% of the sites. With a few exceptions, biosecurity measures were not associated with the frequency of contacts. A 100-sow increase in sow inventory was associated with an increase of 0.34 in the cumulated number of staff entering the breeding unit, of 0.30 in the number of visitors and of 0.19 in the number of live pig movements. Live pig movements were also positively associated with vertically integrated farrow-to-wean (vs. independent farrow-to-wean) production and time interval of 4 weeks or more between farrowing (vs. less than 4). Considering the variety and frequency of contacts observed, biosecurity should be meticulously applied in all breeding herds to prevent endemic and exotic disease introduction.

Differences in musculoskeletal health due to gender in a rural multiethnic cohort: a Project FRONTIER study.

BACKGROUND: Very few studies have investigated differences in musculoskeletal health due to gender in a large rural population. The aim of this study is to investigate factors affecting musculoskeletal health in terms of hand grip strength, musculoskeletal discomfort, and gait disturbance in a rural-dwelling, multi-ethnic cohort. METHODS: Data for 1117 participants (40 years and older, 70% female) of an ongoing rural healthcare study, Project FRONTIER, were analyzed. Subjects with a history of neurological disease, stroke and movement disorder were excluded. Dominant hand grip strength was assessed by dynamometry. Gait disturbance including stiff, spastic, narrow-based, wide-based, unstable or shuffling gait was rated. Musculoskeletal discomfort was assessed by self-reported survey. Data were analyzed by linear, logistic regression and negative binomial regressions as appropriate. Demographic and socioeconomic factors were adjusted in the multiple variable analyses. RESULTS: In both genders, advanced age was a risk factor for weaker hand grip strength; arthritis was positively associated with musculoskeletal discomfort, and fair or poor health was significantly associated with increased risk of gait disturbance. Greater waist circumference was associated with greater musculoskeletal discomfort in males only. In females, advanced age is the risk factor for musculoskeletal discomfort as well as gait disturbance. Females with fair or poor health had weaker hand grip strength. Higher C-reactive protein and HbA1c levels were also positively associated with gait disturbance in females, but not in males. CONCLUSION: This cross-sectional study demonstrates how gender affects hand grip strength, musculoskeletal discomfort, and gait in a rural-dwelling multi-ethnic cohort. Our results suggest that musculoskeletal health may need to be assessed differently between males and females.

Use of the intra-aortic balloon pump to stop gastrointestinal bleeding.

Temporary aortic occlusion can be lifesaving in selected conditions. We describe the unorthodox use of an intra-aortic balloon pump without counterpulsation to achieve temporary vascular control in a patient with shock caused by rapid upper gastrointestinal bleeding. The technique of aortic balloon occlusion has been reported in several clinical circumstances, primarily trauma. However, its use to increase blood pressure and gain time for resuscitation before laparotomy for catastrophic gastrointestinal bleeding has not previously been described.

Retroaortic left renal vein and its implications in abdominal aortic surgery.

The embryological development of the retroperitoneal venous system is a complex process. As a result, the anatomy of the inferior vena cava (IVC) and renal veins shows extensive variability. Improper completion of this process may lead to six anatomical variants: retroaortic left renal vein (LRV) types I and II, circumaortic venous collar, duplication of the IVC, transposition or left-sided IVC, and preaortic iliac confluence. All six are infrequent, but may be encountered during abdominal aortic reconstruction and pose challenging problems to the operating surgeon. Failure to appreciate these anomalies can lead to inadvertent injury and major venous bleeding. Preoperative diagnosis can be made on a CT scan, but this is not always performed prior to aortic surgery. In this report, we analyze two cases of retroaortic LRV complicating abdominal aortic aneurysmectomy, describe the most common infrarenal venous anomalies encountered during aortic surgery, and briefly review the literature.

The effects of psychological factors in sports medicine rehabilitation adherence.

This study investigated the influence of achievement motivation and self-esteem on injury treatment adherence in a general sample of injured patients receiving treatment in a sports medicine clinic. Subjects consisted of both injured athletes and workers who had incurred an on-the-job injury. Based on scales of self-esteem and achievement motivation, patients were categorized as either high or low in self-esteem certainty, self-esteem level, tendency to be task-involved, and tendency to ego-involved in tasks. Treatment adherence was measured by number of missed appointments and by physical therapist ratings of effort and progress. It was found that patients low in self-esteem certainty and high in ego-involvement tended to miss the most treatment appointments. Contrary to previous findings, task-involvement was not found to be related to treatment adherence.

Endoscopic sphincterotomy: the whole truth.

An 8 year experience of 602 patients (median age 76 years) referred for endoscopic management of common bile stones is reported. No patient referred for treatment has been excluded. A diagnostic cholangiogram was achieved in 94 per cent and sphincterotomy was accomplished in 91.5 per cent. The bile ducts were demonstrated to be completely cleared of stones in 491 (81.6 per cent) of 602 patients. A mean number of 1.9 endoscopic retrograde cholangiopancreatography examinations per patient were necessary to achieve this result. Complications of endoscopic sphincterotomy, which were strictly defined, occurred in 10.5 per cent of patients although five patients had two complications (total complication rate 11.3 per cent). The 30-day mortality rate was 2.2 per cent, seven of 13 deaths (1.2 per cent) occurring as a direct result of sphincterotomy. There have been statistically significant improvements in bile duct clearance and complication rates with increasing experience of endoscopists.

Inducible cellular responses to ultraviolet light irradiation and other mediators of DNA damage in mammalian cells.

Both naturally occurring and carcinogen-induced tumors display not only point mutations in cellular oncogenes but also more complex changes in cellular oncogenes and other cellular genes. For this and other reasons, it seems likely that DNA damage in mammalian cells can induce alterations in gene expression that may have both short and long term consequences in the target cell. The purpose of this review is to summarize current available information on inducible responses to UV-irradiation and other mediators of DNA damage in mammalian cells, and to provide some working hypotheses. We have divided these responses into three time frames, immediate (0-12 hours), early (12-48) and late (beyond 48 hours). Immediate responses include the action of DNA repair enzymes, some of which are induced as a consequence of DNA damage, and transient inhibition of DNA synthesis. Within the past few years considerable evidence has accumulated that during this immediate period there is increased expression of certain cellular oncogenes, proteases and proteins whose functions remain to be identified. It is of interest that the expression of some of these genes is also induced by certain growth factors, tumor promoters and heat shock. Alterations in gene expression during the subsequent "early" period (12-48 hrs.) have not been studied in detail, but it is during this period that one can detect increased replication of several types of viruses in cells that harbor these viruses. We have examined in detail the induction of asynchronous polyoma DNA replication (APR) in a rat fibroblast cell line carrying integrated copies of this DNA. We have obtained evidence that UV-irradiation of these cells leads to the synthesis of a 40 kd protein, within the first 1-24 hrs after irradiation, that binds to a specific sequence TGACAACA in the regulatory region of polyoma DNA. We suggest that this protein acts together with other proteins to induce APR and that this serves as a useful model for understanding the mechanisms responsible for amplification of cellular genes, a phenomenon often seen in malignant tumors. Finally, we discuss how the events occurring during the immediate and early periods following DNA damage might lead to late effects in the target cell that are stable and contribute to the genotype and phenotype of some of the progeny of these cells that are destined to become tumor cells.

Enhancement of major histocompatibility class I protein synthesis by DNA damage in cultured human fibroblasts and keratinocytes.

Exposure of primary human fibroblasts or simian virus 40-transformed human keratinocytes to several different classes of DNA damage, including UV light C (254 nm), resulted in a rapid increase in the expression of human major histocompatibility class I (MHC-I) proteins. MHC-I induction was also detected after exposure to low doses of the protein synthesis inhibitor cycloheximide, suggesting that MHC-I induction by DNA damage may be a component in a derepressible cellular SOS pathway.

Distribution of the c-myc oncoprotein in normal and neoplastic tissues of the rat colon.

A rat model of 5-azoxymethane induced colon cancer was studied in order to correlate histopathological changes and the differential distribution of the c-myc protein. Weanling Fisher 344 rats were injected with three, one week apart, subcutaneous injections of 5-azoxymethane (AOM) (15 mg kg-1) and the animals were divided into low and high fat diet groups. Nine colon tumors, of varying degrees of malignancy, that developed in the AOM-treated rats, and sections of normal colonic mucosa were examined. A rabbit polyclonal anti-c-myc antibody produced nuclear staining at 1:100 dilution in cryostat frozen sections of the normal rat colonic mucosa and the colon tumors when prepared with a Cryostat Frozen Sectioning Aid (CFSA). The tissue localization of the c-myc antibody staining revealed: (1) in normal mucosa, nuclei of the basal portion of the mucosa; (2) in adenomatous polyps, nuclei at all levels of the mucosa; and (3) in a carcinoma in situ, intense staining of glandular epithelial cell nuclei at all levels within the tumor. This procedure may provide a sensitive method for detecting abnormal cells in the colonic epithelium that have an altered proliferative capacity.

Endoscopic removal of retained stones after biliary surgery.

Seventy-three patients with retained stones in the common duct after biliary surgery underwent attempted endoscopic removal at a mean interval of 39 days after surgery. Endoscopic extraction was successful in 63 patients (86 per cent). Complications occurred in 14 patients (19 per cent). The most frequent complication was haemorrhage which occurred in nine patients, four of whom required surgery; two other patients required surgery for complications. The complication rate of endoscopic sphincterotomy in recently operated patients may be higher than in the non-operated patient. Less invasive methods, such as dissolution therapy or T tube track extraction, may be preferable as they are associated with less risk. Endoscopic sphincterotomy should be reserved for patients in whom these alternative techniques fail or are inappropriate.

Serum carnitine levels in normal individuals.

Serum carnitine levels have been measured in 178 samples from 75 normal volunteers. We report a wide range of values (10-70 mumol/liter and 8-74 mumol/liter for free and acetylated carnitine, respectively) and a distinct difference between the ranges for males and females (p less than 0.001). There is also substantial, seemingly random fluctuation in any one individual's levels, when measured serially over several weeks.

Experience with the Portacath.

Fifty Portacaths have been inserted in patients undergoing prolonged outpatient chemotherapy, most for haematological disease. Twenty-one are still working at a median duration of 12 months (range 1-27) and a further 15 were functioning normally at the time of the patients death (median survival 6 months). Four functioning Portacaths have been removed, three suspected of causing septicaemia and one believed erroneously to have occluded. Ten have ceased to function and nine of these have been removed. The causes of these failures are nearly all avoidable and are discussed in detail; many occurred early in our experience. With careful attention to detail and with management by trained and interested staff, the Portacath is a safe and reliable device for intermittent vascular access.

A computer simulation for behavior therapy training.

Computer simulation technology has been applied to a wide variety of learning tasks; however, behavior therapy training has not been among them. A computer simulation has recently been developed for use in behavior therapy training. The simulation written for Apple II microcomputers reflects possible referral, assessment, and intervention procedures encountered by a behavior therapist in a mental health center. Forty-two pieces of assessment information may be drawn from 8 general areas, while 6 different interventions may be chosen after a diagnosis is reached. Simulation content and utility were rated highly by both practicing behavior therapists and trainees.

Induction of asynchronous replication of polyoma DNA in rat cells by ultraviolet irradiation and the effects of various inhibitors.

The ability of various DNA damaging agents to induce asynchronous replication of polyoma DNA (APR) in rat cells carrying integrated copies of these DNA sequences may provide a useful model for understanding mechanisms of gene amplification. The present study has explored in detail the ability of UV irradiation to induce APR in the polyoma transformed rat fibroblast cell line H3. We have found that the optimum condition for induction of APR was obtained by irradiating the H3 cells with UV-C (wavelength, 254 nm) at 1-2 J/m2. Irradiation with UV-B (270-360 nm) was much less effective, and no induction of APR was obtained with even high doses of UV-A (345-440 nm). This action spectrum provides evidence that the critical target for induction of APR is DNA. We found that when normal rat fibroblasts were irradiated with UV-C and then fused to H3 cells, this also led to induction of APR. These results provide evidence that the induction of APR by UV-C is mediated by a trans-acting factor. The induction of APR by UV-C was inhibited by high doses of cycloheximide or actinomycin D, suggesting that the production of this trans-acting factor requires de novo protein and RNA synthesis. On the other hand, low doses of cycloheximide or actinomycin D alone were able to induce APR, perhaps by blocking the synthesis of cellular factors that normally inhibit APR. Thus, induction of APR by UV-C provides a useful system for identifying cellular factors that might mediate or prevent the asynchronous replication of various DNA sequences.

Nitropyrenes are inducers of polyoma viral DNA synthesis.

The biological activity of a series of nitropyrenes was assayed by measuring their ability to induce the asynchronous replication of viral DNA in rat fibroblasts transformed by a ts-a mutant of polyoma virus. Concentrations of 10-30 micrograms/ml of 1-nitropyrene (1-NP) induced viral replication, and this effect was enhanced by addition of rat-liver S9 microsomal fraction (300 micrograms/ml) to the culture medium. The response was less than that obtained with 0.1 micrograms/ml of the activated metabolite of benzo[a]pyrene (BP), BP trans-7,8-dihydrodiol-9,10 epoxide (anti) (BPDE). A series of di-, tri-, and tetra-nitropyrenes were also found to induce polyoma DNA replication, in the absence of exogenous microsomal activation, displaying strongly positive effects at 0.5-2.0 microgram/ml. Dose-response curves with 1,6-dinitropyrene (1,6-DNP) from 0.01 to 0.5 microgram/ml indicated that this compound was approximately equipotent with BPDE for induction of polyoma DNA synthesis. Studies of drug metabolism, DNA binding and DNA adduct formation indicate that 1,6-DNP is metabolized in this cell line, binds to DNA, and forms stable adducts. The level of DNA modification seen with 1,6-DNP is higher than that observed under comparable conditions with an equivalent dose of BPDE. These findings provide additional evidence that the nitropyrene class of compounds can exert biological effects in mammalian cells, and that the dinitropyrenes are more potent than 1-NP.

Development of a computerized reference retrieval system: a behavior therapy training tool.

The vastness of the behavior therapy literature base often poses problems for beginning therapists who need greater familiarity with assessment and intervention literature. Hence a computerized reference retrieval system was developed for trainees to access behavior therapy references efficiently. The system contains over 1600 references from 158 problem categories and is economically competitive with commercial systems. Similar systems can be established using currently available microcomputer technology. The present system is primarily used by doctoral and masters students to assist in case conceptualizations and decision making during practicum courses.