Harvested white-tailed deer as sentinel hosts for early establishing Ixodes scapularis populations and risk from vector-borne zoonoses in southeastern Canada.

Due to recent establishment of the blacklegged tick, Ixodes scapularis Say, in southeastern Canada, tick-borne zoonoses (Lyme disease, human granulocytotropic anaplasmosis, and babesiosis) are of growing concern for public health. Using white-tailed deer (Odocoileus virginianus) culled in southwestern Quebec during 2007-2008, we investigated whether hunter-killed deer could act as sentinels for early establishing tick populations and for tick-borne pathogens. Accounting for environmental characteristics of culling sites, and age and sex of deer, we investigated whether their tick infestation levels could identify locations of known tick populations detected in active surveillance, presumed tick populations detected by passive surveillance, or both. We also used spatial cluster analyses to identify spatial patterns of tick infestation and occurrence of tick-borne zoonoses infection in ticks collected from the deer. Adult ticks were found on 15% of the 583 deer examined. Adult male deer had the greatest number (approximately 90%) of adult ticks. Overall, 3, 15, and 0% of the ticks collected were polymerase chain reaction (PCR)-positive for Borrelia burgdorferi, Anaplasma phagocytophilum, and Babesia microti, respectively. Our statistical analyses suggest that sex and age of deer, temperature, precipitation, and an index of tick dispersion by migratory birds were significantly associated with tick infestation levels. Cluster analysis identified significant clusters of deer carrying ticks PCR-positive for A. phagocytophilum, and for deer carrying two or more I. scapularis. Our study suggests that hunter-killed deer may be effective as sentinels for emerging areas of tick-borne anaplasmosis. They may have limited use as sentinels for early emerging I. scapularis tick populations and emerging Lyme disease risk.

Ixodes scapularis ticks collected by passive surveillance in Canada: analysis of geographic distribution and infection with Lyme borreliosis agent Borrelia burgdorferi.

Passive surveillance for the occurrence of the tick Ixodes scapularis Say (1821) and their infection with the Lyme borreliosis spirochaetes Borrelia burgdorferi s.l. has taken place in Canada since early 1990. Ticks have been submitted from members of the public, veterinarians, and medical practitioners to provincial, federal, and university laboratories for identification, and the data have been collated and B. burgdorferi detected at the National Microbiology Laboratory. The locations of collection of 2,319 submitted I. scapularis were mapped, and we investigated potential risk factors for I. scapularis occurrence (in Quebec as a case study) by using regression analysis and spatial statistics. Ticks were submitted from all provinces east of Alberta, most from areas where resident I. scapularis populations are unknown. Most were adult ticks and were collected in spring and autumn. In southern Québec, risk factors for tick occurrence were lower latitude and remote-sensed indices for land cover with woodland. B. burgdorferi infection, identified by conventional and molecular methods, was detected in 12.5% of 1,816 ticks, including 10.1% of the 256 ticks that were collected from humans and tested. Our study suggests that B. burgdorferi-infected I. scapularis can be found over a wide geographic range in Canada, although most may be adventitious ticks carried from endemic areas in the United States and Canada by migrating birds. The risk of Lyme borreliosis in Canada may therefore be mostly low but more geographically widespread than previously suspected.

Molecular dosimetry in rat urine of aflatoxin-N7-guanine and other aflatoxin metabolites by multiple monoclonal antibody affinity chromatography and immunoaffinity/high performance liquid chromatography.

The development of molecular dosimetry methods will simplify the identification of people at high risk for cancer. A combined monoclonal antibody immunoaffinity chromatography/high performance liquid chromatography method has been devised to isolate and quantify aflatoxin-DNA adducts and other metabolites in rat urine samples. We report the production of 11 different monoclonal antibodies recognizing aflatoxin B1, aflatoxin Q1, aflatoxin G1, aflatoxicol, and aflatoxin M1 and the application of these antibodies to a multiple monoclonal antibody affinity chromatography technique. Using the multiple monoclonal antibody affinity column with rat urines obtained from dosed animals, between 90 and 95% of total aflatoxin metabolites can be bound to the column and isolated. Analytical immunoaffinity chromatography/high performance liquid chromatography analysis of these isolated aflatoxins reveals that more than 55% of the aflatoxins in rat urine are aflatoxin-dihydrodiol, aflatoxin-N7-guanine, aflatoxin Q1, aflatoxin M1, aflatoxin P1, and aflatoxin B1, accounting for 1.5, 9.6, 1.8, 34.5, 8.0, and 1.0% of the total aflatoxins, respectively. Further, a perchloric acid digestion of the aflatoxin-N7-guanine peak was used to confirm its identity by its conversion to guanine. The measurement of aflatoxin-N7-guanine excretion in rat urine was examined to assess its utility as a marker of DNA adduct formation in the liver, and a dose-dependent excretion in urine was found with a correlation coefficient of 0.99. A comparison of the dose-dependent residual levels of aflatoxin binding to liver DNA with the amount of aflatoxin-N7-guanine excreted in urine showed a correlation coefficient of 0.98. Besides the nucleic acid adduct excretion data, aflatoxin M1 and aflatoxin P1 were evaluated as molecular dosimeters in the urine. Aflatoxin M1 was found to be an excellent marker, whereas no linear relationship between dose and aflatoxin P1 excretion in urine was found.

Evaluation of hollow fiber bioreactors as an alternative to murine ascites production for small scale monoclonal antibody production.

The objective of this study was to compare monoclonal antibody production in hollow fiber bioreactor systems and murine ascites to determine the feasibility of the bioreactor system as a potential alternative to the use of mice. Three hybridoma cell lines were grown in each of three different hollow fiber bioreactor systems and in groups of 20 mice. Mice were primed with 0.5 ml pristane intraperitoneally 14 days prior to inoculation of 1X10(6) hybridoma cells. Each mouse was tapped a maximum of three times for collection of ascites. Ascites volumes and daily clinical observations were recorded. Bioreactors were harvested three times weekly for 65 day and were monitored by cell counts, cell viability and media glucose consumption. Time and materials logs were maintained. The total quantity of monoclonal antibody produced in 20 mice versus the mean production for the three different bioreactors in 65 days was as follows: cell line 2B11, 455 mg vs. 168 mg; cell line 3C9, 446 mg vs. 565 mg; and cell line RMK, 997 mg vs. 1023 mg. Mean monoclonal antibody concentration ranged from 4.07 to 8.37 mg/ml in murine ascites, and from 0.71 to 11.10 mg/ml in hollow fiber bioreactor system. Although time and material costs were generally greater for the bioreactors, these results suggest that hollow fiber bioreactor system merit further investigations as potentially viable in vitro alternatives to the use of mice for small scale (< 1 g) monoclonal antibody production.

Role of second messengers in the release of motilin from isolated canine intestinal cells.

We examined the intracellular mechanisms for the release of motilin in a preparation of mucosal cells obtained from dog duodenum. Enzymatically dispersed cells were separated by counterflow elutriation to enrich motilin content. Postreceptor activation process was studied by comparing the release of motilin obtained with exogenous analogues or stimulants of the various intracellular signal pathways. Dibutyryl cyclic adenosine monosphate (10(-3) M) and forskolin (10(-5) M) induced a moderate response in motilin secretion. Phorbol ester beta-phorphol-12-myristate-13-acetate and phospholipase C were potent stimulants of motilin release. Raising intracellular calcium concentration by calcium ionophore A23187 or increasing calcium content in the incubation milieu failed to modify the secretion of motilin. Analogues of 8-bromoguanosine-3'5' cyclic monosphosphate were ineffective. Therefore, the motilin cell was very sensitive to protein kinase C activators and appeared moderately responsive to a stimulation of the adenylate cyclase pathway.

Cholinergic regulation of motilin release from isolated canine intestinal cells.

An in vitro model was developed to study the regulation of motilin release from its endocrine-producing cell. Enzymatically dispersed cells from canine duodenojejunal mucosa were separated by centrifugal counterflow elutriation to enrich motilin content. From the motilin-enriched cell preparation, the release of motilin was determined under stimulation with various agents. Carbachol dose-dependently stimulated the release of motilin from its producing cell. Bombesin, morphine, and erythromycin, recognized stimulants for motilin release in vivo, failed to influence the secretion of motilin in vitro. Serotonin, GIP, CCK, pentagastrin, cisapride, neosynephrine, isoproterenol, or muscimol were also ineffective in the in vitro model. The response to carbachol was abolished by atropine but was not affected by somatostatin, serotonin, secretin, CCK, or GIP. These results suggest that muscarinic receptors are present on the motilin cell membrane and that acetylcholine is a major regulator of motilin release.

Neural and muscular receptors for motilin in the rabbit colon.

Motilin receptors were classically recognized in the gastroduodenal area, where they help to regulate interdigestive motility. More recently, motilin receptors were identified in the colon where their biologic significance remains unclear. We aimed here to characterize the motilin receptors of the rabbit colon. Distal colon and duodenum were obtained from sacrificed rabbits. Tissues homogenized by Polytron were submitted to differential centrifugation to obtain neural synaptosomes or smooth muscle plasma membranes enriched solutions. Motilin binding to these membranes was determined by the displacement of (125)I MOT by the native peptide MOT 1-22, or by peptide analogues MOT 1-12 [CH(2)NH](10-11) or GM-109 and by erythromycin derivative GM-611. Motilin binding capacity was maximum in colon nerves (49.5 +/- 6.5 fmol/mg protein vs. 19.9 +/- 2.5 in colon muscles or 9.4 +/- 2.8 and 6.6 +/- 1.2 in duodenal muscles and antral nerves respectively); all tissues expressed similar affinity for MOT 1-22, and the motilin agonist GM-611 bound equally to neural or muscle tissues from the rabbit colon; the synthetic antagonist MOT 1-12 [CH(2)NH](10-11) showed greater affinity for colon nerves than for colon muscles (plC50: 7.23 +/- 0.07 vs. 6.75 +/- 0.03). Similar results were obtained with the peptide antagonist GM-109; receptor affinity toward MOT 1-12 [CH(2)NH(10-11)] was always five times superior in neural tissues, whether they came from the colon or the antrum, than in muscle tissues, whether they were obtained from colon or from duodenum. Motilin receptors are found in very high concentration in nerves and in muscles from rabbit colon; specific motilin receptor subtypes are identified in nerves (N) and muscles (M) of the rabbit colon; N and M receptor subtypes seem independent of the organ location.

Digestive motor effects and vascular actions of CGRP in dog are expressed by different receptor subtypes.

Calcitonin gene-related peptide (CGRP) is a 37 AA peptide localized in blood vessels and nerves of the GI tract. Activation of CGRP receptors (subtypes 1 or 2) usually induces vasodilation and/or muscle relaxation, but its effects in dog and on gastroduodenal motility are still unclear. This study looked for the effect of CGRP and the antagonist CGRP8-37, specific for CGRP type 1 receptor, 1) on GI motility (interdigestive and postprandial), and 2) on hemodynamy, in conscious dogs. During the interdigestive period, the infusion of CGRP1-37 (200 pmol/kg/h) or CGRP8-37 (2000 pmol/kg/h) did not modify the duration of the migrating motor complex nor the release nor the motor action of plasma motilin. The gastric emptying of a solid meal (15 g meat/kg) was reduced by the administration of CGRP1-37 (AUC: 2196 +/- 288.6 versus 3618 +/- 288.4 with saline or T12: 78 +/- 7.3 versus 50 +/- 4.3 min; P < 0.01) and this effect was reversed by the antagonist CGRP8-37. CGRP1-37 significantly (P < 0. 01) diminished arterial pressures (118 +/- 1.6/64 +/- 1.4 vs. 125 +/- 1.4/75 +/- 1.2 mmHg with saline) and accelerated the basal cardiac rhythm (110 +/- 1.4 versus 83 +/- 1.6 beats/min). However, CGRP8-37 failed to block the cardiovascular effects of CGRP1-37. In dog, CGRP could influence digestive motility by slowing the gastric emptying of a meal through an action on CGRP-1 receptors. Hemodynamic effects of CGRP were not blocked by CGRP8-37 and seem therefore mediated by CGRP-2 receptor subtype.

Two new peptides to improve post-operative gastric ileus in dog.

Peptides can influence gastrointestinal motility, and from data obtained earlier in rats, we hypothesized that MTL-RP/Ghrelin, as well as CGRP receptor antagonist 8-37, could improve gastric post-operative ileus in dog. Dogs submitted to laparotomy were perfused with or saline or CGRP 8-37 or MTL-RP/Ghrelin on days 1-4 post-operatively while gastric emptying was estimated by measuring the postprandial increase in plasma acetaminophen ingested with a meal. As expected, in saline-treated animals the gastric emptying function was impaired post-operatively. The total amount of acetaminophen emptied (AUC over 150 min) on post-operative days 1-4 reached respectively 31+/-5%, 65+/-8%, 60+/-8% and 62+/-8% of the normal emptying capacity. CGRP antagonist increased the total emptying of acetaminophen to 52+/-5% on day 1, 95+/-2% on day 2 and 103+/-3% (P<0.05) on day 3. The delayed emptying of acetaminophen seen post-operatively in saline-treated animals could be completely reversed by MTL-RP/Ghrelin (P<0.01) whether it was given at 100 microg/kg on day 2 (102+/-7% of the normal emptying capacity), 4 microg/kg on day 3 (106+/-7%) or 20 microg/kg on day 4 (132+/-8%). As found earlier in rodents, CGRP receptor antagonist 8-37 as well as MTL-RP/Ghrelin are potent prokinetics to improve post-operative gastric ileus in dog.

Heterogeneity of motilin receptors in the gastrointestinal tract of the rabbit.

Motilin, a 22-amino acid peptide synthesized in endocrine cells of intestinal mucosa, stimulates GI smooth muscle contractility. To elucidate the mode of action of motilin, we attempted to determine whether motilin receptors are localized on nerve cells or on smooth muscle cells of the GI tract. Mucosa-free tissues from rabbit antrum and duodenum were homogenized separately with a Polytron prior to differential centrifugation to obtain synaptosome or plasma membrane-enriched fractions, as determined by the distribution of [3H]saxitoxin (SAX) binding (neural membranes) and 5' nucleotidase (5'N) activity (smooth muscle plasma membranes). Motilin binding was evaluated by the displacement of [125I]motilin by motilin (1-22) on the various membrane fractions. In the antrum, motilin binding was highly correlated with SAX binding (r = 0.81, p < 0.0005), and also significantly with 5'N activity (r = 0.54, p < 0.05). In the duodenum, motilin binding correlated significantly with 5'N activity (r = 0.67, p < 0.005), but not with SAX binding (r = -0.11, NS). Receptor affinity, for the motilin antagonist MOT(1-12)[CH2NH]10-11, for motilin(1-22), and for the motilin agonist erythromycin lactobionate was significantly (p < 0.001, p < 0.001, and p < 0.05, respectively) higher in SAX-enriched fractions from the antrum than in 5'N-enriched fractions from the duodenum. Therefore, in the rabbit: 1) motilin receptors appear to be predominantly located on nerve tissues in the antrum and restricted to smooth muscle cells in the duodenum, and 2) antral receptors and duodenal receptors displayed different pharmacological characteristics, probably corresponding to two specific and heterogeneous motilin receptor subtypes.

Motilin-like-immunoreactivity in intestine and brain of dog.

Motilin-like-immunoreactivity was detected in various regions of canine intestinal tract and brain. Its content in the brain was much smaller than in the gut. Its regional distribution was not uniform in both organs. On gel chromatography (G-50 SF), intestinal extracts revealed a main molecular form of motilin-like-immunoreactivity corresponding to motilin 1-22, while, in the brain, it eluted predominantly with the void volume. Further characterization of this later substance does not suggest it is strongly related to motilin. Putative motilin precursors of 14 kd and 6 kd are detectable in small concentration in intestinal mucosa.

[Carotid endarterectomy: preoperative medical history and long-term outcome of 82 patients]. / Endartériectomie carotidienne: histoire médicale préopératoire et devenir à long terme de 82 patients.

Using medical files, death certificates and an interview at home for the survivors, a long term retrospective follow-up study was done for 82 subjects operated for carotid stenosis. Causes of death, survival rates and medical history of survivors were studied. Subjects were classified in two preoperative risk categories according to their medical history prior to angiography: low risk (36 subjects) and medium risk (46 subjects). None of the subjects were lost during the follow-up period which varies from 81 to 105 months. At seven years, observed survival rate is significantly lower for the medium risk patients than for the low risk patients (43.0 +/- 8.6 versus 80.6 +/- 6.6; X2 M-H, p = 0.006). The difference between the survival rates is markedly noticeable after the fifth year of follow-up. Besides, the percentage of survivors who have developed cerebrovascular problems after the operation is significantly higher in the medium risk group than the low risk group (54.5% versus 25.0%, X2 p congruent to 0.04). Does this mean that the preoperative risk classification separates two different stages or two different forms of atherosclerosis?

[Rehabilitation and the socio-occupational reintegration of workers who have had a myocardial infarct: a pilot study]. / La réadaptation et la réinsertion socio-professionnelle des travailleurs ayant subi un infarctus du myocarde: étude pilote.

OBJECTIVE: To evaluate in a pilot study some psychosocial impacts of a multidisciplinary rehabilitation program on work reintegration of postmyocardial infarction (MI) patients. PATIENTS AND METHODS: Two groups of 19 workers among public and governmental enterprises of the greater Quebec city area admitted to hospital for uncomplicated MI where recruited for the study. One group received multidisciplinary cardiac rehabilitation intervention and a structured return to work program. The second group received the usual care post-MI (no organized rehabilitation program). Over a period of 15 months, the following variables were measured patients' perception of their loss of autonomy, and loss of capacity to manage their emotions, physical work capacity and their capacity to meet work requirements. The impact of the intervention on convalescence time and patients' stability at work were also evaluated. RESULTS: The rehabilitation group showed a better development than the usual care group of capacity to manage emotions (P=0.004) and of capacity to return to work (P=0.006). Furthermore, the patients in the intervention group reintegrated their work environment following a convalescence of 84.32+/-35.39 days compared with 151.39 +/-75.53 days for the usual care patients (P=0.0007). CONCLUSION: A multidisciplinary rehabilitation program and a structured return to work program are beneficial for sociovocational reintegration of post-MI patients.

[Endorphin control of blood motilin and the gastrointestinal motor complex in the dog]. / Contrôle par les opiacés endogènes de la motilinémie et du complexe moteur migrant chez le chien.

To evaluate the role of endogenous opiates in the regulation of plasma motilin and the interdigestive motor complex of the small bowel, naloxone was administered in dogs. During the infusion of the opiate antagonist, the frequency of motilin cyclic release and of the motor complex was decreased. Moreover, with naloxone, peak increases in plasma motilin were similar to those measured during the control period in 5 of the 8 experiments. They were lower in 3 occasions. These results suggest that endogenous opiates do not play an essential role in the basal organization of intestinal interdigestive motility but that they are able to modify the frequency and the amplitude of motilin cyclic release. They support the possibility that endogenous opiates could, in some circumstances, exert a significant influence on the motor activity of the small intestine.

Associations between Ixodes scapularis ticks and small mammal hosts in a newly endemic zone in southeastern Canada: implications for Borrelia burgdorferi transmission.

Immature Ixodes scapularis infestation and Borrelia burgdorferi infection of wild small mammals were studied from June to October in 2007 and from May to October in 2008 at 71 study sites in a zone where I. scapularis populations and environmental Lyme disease risk are emerging in southwestern Quebec. Seasonal host-seeking activity of immature I. scapularis was similar to patterns reported previously in Canada and the USA: nymphal activity peaked in spring while larval activity peaked in late summer. Synchronous activity of nymphs with some larvae was observed in late spring, which could favour establishment of B. burgdorferi strains that cause short-lived infections in their hosts. White-footed mice (Peromyscus leucopus), deer mice (P. maniculatus), chipmunks (Tamias striatus), and red squirrels (Tamiasciurus hudsonicus) carried 92.0% of the larvae and 94.2% of the nymphs collected. Adult male white-footed mice carried significantly larger numbers of both larval and nymphal I. scapularis than other species and classes of small mammals (different demographic groups or physiological status: age, sex, sexual activity). We conclude that seasonality and host association were comparable to previous studies in North America, even in the context of a newly endemic pattern of low infection prevalence and low densities of host-seeking and feeding I. scapularis in southwestern Quebec. Our studies suggest that B. burgdorferi transmission cycles are focused on adult male mice (which carried 35% of all feeding ticks collected in the study), so control methods targeting this class of hosts may be particularly effective. However, our study also suggested that habitats containing a diverse host structure may dilute transmission cycles by partitioning of nymphal and larval ticks on different host species.

An ergonomic approach to reorganize parking inspection agents' work productivity, health and safety in São Paulo, Brazil.

OBJECTIVE: The Traffic Engineering Company of the City of São Paulo (Brazil) observed a decrease in productivity, and an increase in sick leave, accidents and psychological distress among their parking inspection agents. To document this situation, qualitative research was undertaken to obtain an in-depth comprehension of work activity. PARTICIPANTS: Workers, managers and health and safety professionals contributed to the documentation of the problem and to the proposal of possible solutions. METHODS: Ergonomic work analysis focusing on real work activity, as well as interviews with individual or groups of stakeholders, were conducted. RESULTS: This research revealed that political-economic factors gradually contributed to: 1) an increasing work load; 2) growing fatigue throughout the day, increasing the workers' vulnerability to incidents and accidents and their tendency to react inappropriately to violence experienced on the street; and 3) excessive individual responsibility to manage dangerous situations. CONCLUSIONS: Recommendations to ameliorate the situation are proposed. These suggestions are discussed in terms of feasibility given the impact of macro social factors upon micro work activity, and the associated potential expansion of the ergonomist's role.

Differential recognition of oral indigenous bacteria by salivary immunoglobulins A and G.

Assuming that salivary immunity to indigenous microorganisms could develop, we assessed antibacterial reactivities of natural salivary antibodies in specific pathogen-free inbred mice. An ELISA was set up, using whole bacterial cells, to map reactivities of salivary IgA and IgG which accounted respectively for 91% and 8.7% of salivary Ig's in the BALB/c mouse. Representative strains of seven species from three genera (Lactobacilli, Staphylococci, and Streptococci), including major and minor components of the murine oral flora (38, 43, and 8%, respectively), were used to determine the presence and level of specific antibodies in individual saliva. It was verified that naturally occurring IgA antibodies can display diverse antibacterial reactivities. A characteristic profile emerged for salivary IgA where antibodies to Streptococcus faecalis predominate. Natural salivary IgG antibodies did not show the same reactivity pattern as IgA, anti-Lactobacilli and anti-Staphylococci reactivities being much less frequent in the salivary IgG repertoire. However, antibodies to S. faecalis occurred at the same high frequency for both isotypes (62-70% of the samples). Besides being species-specific, antibacterial reactivities were also found to be strain-specific. Broad variations in antibacterial titers were detected among individual mice under standardized experimental conditions. Present data thus suggest that the dynamics of salivary antibody production in the mouse reflect a differential natural sensitization of the secretory (IgA) versus the systemic (IgG) immune systems by distinct populations of indigenous bacteria.

Interdigestive intestinal motility in dogs with chronic exclusion of bile from the digestive tract.

To elucidate the role of bile delivery into the duodenum on the regulation of plasma motilin and on the interdigestive migrating complex, three dogs were operated upon to ligate the main bile duct and divert the biliary flow into the urinary bladder via a Foley catheter. After the operation, despite the chronic diversion of bile from the digestive tract, all animals maintained an excellent health status and exhibited recurrent periods of phase III motor activity migrating from the duodenum to the ileum, which were associated with cyclic increases in plasma motilin. Following the infusion of pooled dog bile (1 mL/min for 10 min) into the duodenum, a premature phase III and a concomitant rise in plasma motilin were observed. These results suggest, that although bile delivery into the duodenum can induce motilin increase in plasma and period of phase III activity in the gut, this phenomenon does not constitute an essential stimulus for the release of motilin and for the induction of the phase III of the interdigestive migrating complex.

Quality of life of 50 carotid endarterectomy survivors: a long-term follow-up study.

The quality of life of 50 subjects who underwent carotid endarterectomy was investigated in a follow-up study varying from 81 to 105 months. Subjects were retrospectively classified in either low or medium preoperative risk categories. Risk was determined from the previous medical history and the findings of the carotid angiography. Quality of life was estimated from the functional level and such psychosocial factors as work, leisure, and finances during the follow-up period. All subjects had minimal dysfunction in ADL and cognition. Medium risk subjects, however, had marked dysfunction in home and outside activities and social interaction. Fifty percent of the working subjects were forced to take an early retirement. Quality of life seems more affected by cardiovascular problems in the 22 medium risk patients and by neurologic problems in the 28 low risk patients. This study suggests the importance of long-term rehabilitation goals to preserve the quality of life.