Experiences, attitudes, and perceptions of accredited advisors towards a voluntary producer training program for Canadian Quality Milk.

This study was conducted to understand the experiences, attitudes, and perceptions of advisors towards the voluntary producer training program offered in Ontario prior to the first Canadian Quality Milk validation. A survey was used to gather advisor opinions and was sent by e-mail to all advisors listed on the Dairy Farmers of Ontario (DFO) website. ANOVA and Chi-Square analyses were utilized to identify significant differences among respondent groups (veterinarian, non-veterinarian, and unidentified), linear regression was used to evaluate associations with the number of producers an advisor trained, and logistic regression was performed to evaluate associations with advisor opinions. Advisors who trained more producers were more likely to provide both classroom and on-farm sessions, train producers with greater consistency in audit results, and remain in communication with producers they had trained. Advisor-suggested improvements for similar programs in the future were increased compensation, more use of interactive learning, and re-structured advisor training.

Expériences, attitudes, et perceptions de conseillers accrédités envers un programme de formation volontaire des producteurs pour Lait canadien de qualité. La présente étude a été menée pour comprendre les expériences, attitudes et perceptions des conseillers envers le programme volontaire de formation offert en Ontario avant la première validation de Lait canadien de qualité. Un sondage a été utilisé pour récolter les opinions des conseillers et fut acheminé par courriel à tous les conseillers listés sur le site web des Producteurs de lait de l'Ontario (DFO). Des analyses ANOVA et Chi-carré ont été utilisées pour identifier les différences significatives parmi les groupes de répondants (vétérinaires, non-vétérinaires, et non-identifiés), une régression linéaire a été utilisée pour évaluer les associations avec le nombre de producteurs et de conseillers formés, et une régression logistique fut effectuée pour évaluer les associations avec les opinions des conseillers. Les conseillers qui ont formé plus de producteurs étaient plus susceptibles à fournir des sessions de formation en classe et à la ferme, de former les producteurs avec une plus grande constance dans les résultats d'audits, et de demeurer en communication avec les producteurs qu'ils avaient formés. Des améliorations suggérées par les conseillers pour des programmes similaires futurs étaient d'augmenter le montant des compensations, une plus grande utilisation d'apprentissage interactif, et une restructuration de la formation des conseillers.(Traduit par Dr Serge Messier).

Relationship between postmilking standing duration and risk of intramammary infection in freestall-housed dairy cows milked 3 times per day.

Recent evidence exists to suggest that the risk of subclinical mastitis, particularly those infections caused by environmental pathogens, in dairy cows is related to standing and lying patterns. The objective of this study was to determine the association between postmilking standing duration (PMSD) of dairy cows milked 3×/d and risk of intramammary infection (IMI). Four commercial freestall dairy herds in Eastern Ontario, milking 3×/d, were enrolled in a longitudinal study. Forty Holstein-Friesian cows per herd were randomly selected as focal animals from those cows in each herd that met our selection criteria of days in milk (<200 d) and somatic cell count (<100,000 cells/mL). The study consisted of three 28-d periods. The study began following a regularly scheduled Dairy Herd Improvement test with the collection of quarter-level milk samples from all focal animals. Bacteriology was used to confirm infection status at the start of the study and for determination of incidence of IMI throughout the study. A new IMI was defined as having a culture-positive quarter-level sample when the previous sample (28 d prior) had been culture negative for the pathogen of interest. Four sets of quarter-level milk samples were obtained for each focal animal. Lying behavior was recorded for 5 d after each milk sampling using data loggers. For these 5 d, individual milking times, production, and feeding times were also recorded. Postmilking standing duration was analyzed by milking event, with increased PMSD being positively associated with provision of fresh feed or freshly pushed-up feed around the time of milking, greater feed bunk space per cow, and lower freestall stocking density. Over the study period, 456 new IMI were detected, resulting in a mean herd incidence rate of 3.22 IMI per quarter year. Coagulase-negative staphylococci (CNS) and Corynebacterium spp. IMI were statistically analyzed to determine relationship with PMSD; they were the 2 predominant pathogens representing 45 and 31% of IMI, respectively. Only CNS IMI was associated with PMSD. A nonlinear relationship between PMSD and incidence of CNS IMI was found; cows with a PMSD of 90 to 120 min were at a reduced risk for CNS IMI. The risk of experiencing CNS IMI was also reduced with increased frequency of feed push-ups and provision of fresh feed 60 min before to 90 min after milking and >540 min after milking. These results indicate that management practices that promote PMSD of 90 to 120 min, such as the provision of fresh feed or freshly pushed-up feed around the time of milking, providing ample feed bunk space per cow, and keeping freestall stocking density low, should be encouraged to reduce the risk of CNS IMI in freestall-housed cows milked 3×/d.

Associations of herd- and cow-level factors, cow lying behavior, and risk of elevated somatic cell count in free-stall housed lactating dairy cows.

Recent evidence suggests that the risk of intramammary infection in dairy cows is related to lying patterns. The objectives of this study were to quantify the standing and lying behavior of dairy cows milked 3×/d, determine the cow- and herd-level factors associated with these behaviors, and relate these findings to the risk of an elevated somatic cell count (SCC). Five commercial free-stall dairy herds in Eastern Ontario, milking 3×/d, were enrolled in a longitudinal study. Forty Holstein-Friesian cows/herd were randomly selected as focal animals based on days in milk (<200 d) and SCC (<100,000 cells/mL). Farms were followed for 4, 5-week periods. Individual-cow SCC was recorded at the beginning of each period and end of the final period. Elevated SCC (eSCC) was used as an indicator of subclinical mastitis. A new incident eSCC was defined as an individual cow that started the period with a SCC <100,000 cells/mL but whose next SCC exceeded 200,000 cells/mL. Lying behavior was recorded 5d after each milk sampling using data loggers. For these 5d, individual milking times and feeding times were also recorded. On d1 of each recording period 2 trained observers scored focal cows for hygiene and lameness. Throughout the course of the study, cows averaged 11.2h/d of lying time, split into 8.6 lying bouts/d that were on average 84.6 min in length. Later lactation cows had longer daily lying times that were split into fewer lying bouts of longer duration than cows earlier in lactation. Lame cows had longer daily lying times and lying bout durations than non-lame cows. Cows with greater milk yield had lower lying times than lower producing cows. Average post-milking standing time across the study herds was 103 min. Manipulation of feed (feed delivery or push-up) by the stockperson, in the hour before milking or shortly thereafter, resulted in the longest post-milking standing times. Over the study period, 48 new eSCC were detected, resulting in a mean herd incidence rate of 0.91 eSCC/cow-year at risk for all study herds. A non-linear relationship between post-milking standing time and eSCC incidence was found; compared to those cows that lie down <90 min after milking, cows that lie down for the first time >90 min after milking had a lower risk of acquiring a new eSCC. The risk of experiencing an eSCC was also increased in multiparous cows, and in those cows with a higher SCC at the beginning of the study. These results indicate that management practices that promote post-milking standing time, such as the manipulation of feed delivery around milking times, should be encouraged to reduce the risk of cows experiencing new eSCC.

Fish in hot water: hypoxaemia does not trigger catecholamine mobilization during heat shock in rainbow trout (Oncorhynchus mykiss).

Rainbow trout (Oncorhynchus mykiss) exposed to an acute heat shock (1 h at 25 °C after raising water temperature from 13 °C to 25 °C over 4 h) mount a significant catecholamine response. The present study investigated the proximate mechanisms underlying catecholamine mobilization. Trout exposed to heat shock in vivo exhibited a significant reduction in arterial O(2) tension, but arterial O(2) concentration was not affected by heat shock, nor was catecholamine release during heat shock prevented by prior and concomitant exposure to hyperoxia (to prevent the fall in arterial O(2) tension). Thus, catecholamine mobilization probably was not triggered by impaired blood O(2) transport. Heat-shocked trout also exhibited an elevation of arterial CO(2) tension coupled with a fall in arterial pH, but these factors are not expected to trigger catecholamine release. The changes in blood O(2) and CO(2) tension occurred despite a significant hyperventilatory response to heat shock. Future studies should investigate whether catecholamine mobilization during heat shock in rainbow trout is triggered by a specific effect of high temperature activating the sympathetic nervous system via a thermosensitive transient receptor potential channel.

Agonistic encounters and cellular angst: social interactions induce heat shock proteins in juvenile salmonid fish.

Juvenile salmonid fish readily form dominance hierarchies when faced with limited resources. While these social interactions may result in profound behavioural and physiological stress, it is unknown if this social stress is evident at the level of the cellular stress response--specifically, the induction of stress or heat shock proteins (Hsps). Thus, the goal of our study was to determine if Hsps are induced during hierarchy formation in juvenile rainbow trout (Oncorhynchus mykiss). To this end, we measured levels of three Hsps, Hsp70, Hsc (heat shock cognate)70 and Hsp90 in the white muscle, liver and brain of trout that had been interacting for 36 h, 72 h or 6 days. Our data indicate that Hsps are induced in both dominant and subordinate fish in a time- and tissue-specific manner. In further mechanistic experiments on fasted and cortisol-treated fish, we demonstrated that high plasma cortisol does not affect Hsp induction in trout white muscle or liver, but both conditions may be part of the mechanism for Hsp induction with social stress in the brain. We conclude that the behavioural and physiological stress experienced by juvenile rainbow trout in dominance hierarchies can be extended to the induction of Hsps.

Drotrecogin alfa (activated) in severe falciparum malaria.

Drotrecogin alfa (activated) is a drug licensed for the treatment of severe sepsis. We describe the care of a 61-year-old man who developed multi-organ failure secondary to severe falciparum malaria infection with parasitaemia levels of 40%. Included in his care were an exchange blood transfusion and an infusion of Drotrecogin alfa (activated). Within hours of starting the infusion of Drotrecogin alfa (activated), the patient's clinical condition stopped deteriorating. Steady improvement followed with weaning from ventilatory assistance on day 14 post admission. The patient made a full recovery and was discharged home following rehabilitation. The indications for Drotrecogin alfa (activated) and the appropriateness of its use in severe malaria with multi-organ failure are discussed. Drotrecogin alfa (activated) may be a useful treatment in patients with multi-organ failure resulting from severe malaria.

Age, apolipoprotein E4, and the risk of HIV dementia: the Hawaii Aging with HIV Cohort.

There are discrepant findings regarding the risk of HIV-associated dementia (HAD) relating to apolipoprotein E4, suggesting other factors may modulate risk. Furthermore, evidence suggests a changing phenotype of HAD in the era of highly active antiretroviral therapy (HAART), prompting a need to determine if new disease markers have emerged. In this analysis, APOE genotype was determined for 182 participants enrolled in the Hawaii Aging with HIV Cohort. After controlling for age and diabetes status, an independent risk of HAD relating to E4 was seen in older participants [OR=2.898 (1.031-8.244)] but not in younger participants [OR=0.373 (0.054-1.581)]. Several proposed mechanisms may underlie this association. Consideration of non-traditional risk factors for HAD in older HIV patients may yield new markers of disease in the era of HAART.

Higher frequency of dementia in older HIV-1 individuals: the Hawaii Aging with HIV-1 Cohort.

BACKGROUND: Antiretroviral therapy has improved survival for HIV-1-infected individuals. The neuroepidemiologic implications of HIV-1 in an aging population are not well known, particularly the prevalence of HIV-associated dementia (HAD). METHODS: The authors report a baseline cross-sectional analysis of 202 HIV-1-seropositive individuals enrolled into one of two groups of the Hawaii Aging with HIV Cohort: older (50 or more years old, n = 106) and younger (20 to 39 years old, n = 96). Neuropsychological, neurologic, medical, and laboratory data were obtained at enrollment. Participant cognitive status was classified (research case definitions) using American Academy of Neurology (1991) criteria in a consensus conference of physicians and neuropsychologists. RESULTS: HAD was more frequent in older (25.2%) compared to younger (13.7%) individuals (p = 0.041) corresponding to an OR of 2.13 (95% CI: 1.02 to 4.44) for the older compared to the younger group. After adjusting for education, race, substance dependence, antiretroviral medication status, viral load, CD4 lymphocyte count, and Beck Depression Inventory score, the odds of having HAD among individuals in the older group was 3.26 (1.32 to 8.07) times that of the younger group. CONCLUSIONS: Older age is associated with increased HAD in this HIV-1 cohort. Underlying mechanisms are unclear but do not appear related to duration of HIV-1 infection.

Symptomatic distal sensory polyneuropathy in HIV after age 50.

OBJECTIVE: To determine if aging changes the frequency, severity, or manifestations of symptomatic distal sensory polyneuropathy (SxDSPN) in patients with HIV-1. METHODS: Prospective observations of 70 older (age < or = 50) and 56 younger (age 20 to 40) patients with HIV, and a control group of 48 older non-HIV patients, were conducted utilizing neurologic examination, neuropsychological testing, lumbar puncture, laboratory, and medical history. RESULTS: The frequency of SxDSPN among older HIV patients was 50.4%, compared to 19.6% among younger HIV patients (p < 0.001). SxDSPN among control patients occurred in 4.2%, similar to the general population. Older compared to younger HIV patients demonstrated more severe symptoms (p = 0.02) and greater deficits for vibration (p < 0.01). Increasing numbers of neuropathic comorbidities among older compared to younger HIV patients were associated with increasing severity of deficits to pinprick (p = 0.003). Dementia and SxDSPN coexisted in 36% of the older HIV patients and in none of the younger HIV patients (p = 0.021). Older HIV patients with nadir CD4 < or =200 cells/mL were 4.23 times as likely to have SxDSPN than older patients with nadir CD4 >200 cells/mL (p = 0.007). Vibratory deficits excessive to pinprick deficits predicted SxDSPN among older (OR 2.83) but not younger seropositive patients (p = 0.036). CONCLUSIONS: Age > or = 50 increases the frequency of SxDSPN, and is associated with both vibratory loss as the predominant sensory deficit and increased severity of pinprick loss among symptomatic patients with neuropathic comorbidities. SxDSPN is associated with both dementia and low nadir CD4 in HIV-positive patients aged 50 and greater.

Tracheal trauma from percutaneous tracheostomy using the Griggs method.

In a safety evaluation study, relative force and distance measurements during percutaneous tracheostomy were recorded using specially monitored Griggs guidewire dilating tracheostomy forceps on 12 cadavers scheduled to undergo postmortem examination the same day. All measurements were recorded in millivolts and were converted to force and distance via appropriate calibration tables. Markedly more force was required for tracheal destruction than for therapeutic tracheal dilation (87.7 N +/- 19 N vs. 31.6 N +/- 17.1 N, p <0.001). Also relatively less force was required for therapeutic tracheal dilation than for dilation of the pretracheal tissues (44.4 N +/- 17.1 N vs. 31.6 N +/- 17.1 N, p <0.05). These results suggest that the Griggs tracheostomy forceps have a reasonable margin of safety in that tracheal destruction is unlikely to occur inadvertently during therapeutic dilation. Second, the dilation of pretracheal tissues can act as useful guide in knowing how much force to apply in a therapeutic dilation.

Pulmonary oedema after ophthalmic regional anaesthesia in an unfasted patient undergoing elective surgery.

An elderly female patient presenting for phaco-emulsification and intra-ocular lens implant under local anaesthesia developed pulmonary oedema after surgery and underwent emergency tracheal intubation. The pulmonary oedema may have been caused by her omission of routine oral diuretic medication before surgery and having to lie flat for the procedure. The patient had not been fasted before surgery, as is accepted practice in many hospitals. This made emergency tracheal intubation potentially hazardous. The patient made a full recovery. The issues of pre-operative assessment, fasting and the withholding of diuretic medication before elective eye surgery under local anaesthesia are discussed.

Tests of a cellular model for constant branch distribution in the filamentous fungus Neurospora crassa.

The growth of mycelial fungi is characterized by the highly polarized extension of hyphal tips and the formation of subapical branches, which themselves extend as new tips. In Neurospora crassa, tip growth and branching are crucial elements for this saprophyte in the colonization and utilization of organic substrates. Much research has focused on the mechanism of tip extension, but a cellular model that fully explains the known phenomenology of branching by N. crassa has not been proposed. We described and tested a model in which the formation of a lateral branch in N. crassa was determined by the accumulation of tip-growth vesicles caused by the excess of the rate of supply over the rate of deposition at the apex. If both rates are proportional to metabolic rate, then the model explains the known lack of dependence of branch interval on growth rate. We tested the model by manipulating the tip extension rate, first by shifting temperature in both the wild type and hyperbranching (colonial) mutants and also by observing the behavior of both tipless colonies and colonyless tips. We found that temperature shifts in either direction result in temporary changes in branching. We found that colonyless tips also pass through a temporary transition phase of branching. The tipless colonies produced a cluster of new tips near the point of damage. We also found that branching in colonial mutants is dependent on growth rate. The results of these tests are consistent with a model of branching in which branch initiation is controlled by the dynamics of tip growth while being independent of the actual rate of this growth.

Phaeochromocytoma: an unusual cause of hypertension in pregnancy.

A primiparous, full-term, 28-year-old woman underwent an emergency lower segment Caesarean section under epidural anaesthesia for failure to progress in the first stage. Despite an uneventful pregnancy and delivery, she developed a hypertensive crisis in the postoperative period complicated by acute pulmonary oedema requiring ventilation for 48 h in the intensive care unit. Intravenous magnesium sulphate infusions and hydralazine boluses were used to control the blood pressure, which was associated with clonus, hyperreflexia, tachycardia and profuse sweating. The patient made a good recovery. Later measurement of urinary catecholamines in the recovery phase showed greatly elevated levels of norepinephrine, dopamine and vanillyl mandelic acid. Further investigations included a normal abdominal computed tomography scan and a I-123 meta-iodo-benzyl-guanidine scintigraphy scan which revealed a 3- to 4-cm irregular tumour located at the level of the lower pole of the right kidney and further liver hot spots. Intravenous magnesium sulphate infusion proved successful in controlling hypertension caused by a phaeochromocytoma in the postpartum period.

Haemodynamic changes during beating heart coronary surgery with the 'Bristol Technique'.

OBJECTIVES: Optimal exposure and stabilization of the target coronary vessel is essential to allow the construction of a precise coronary anastomosis during off pump coronary surgery. However, this might be achieved at the expense of significant haemodynamic deterioration, particularly while grafting the circumflex and the posterior descending coronary arteries. The present study was designed to assess the haemodynamic changes with the beating heart positioned for grafting the three main coronaries. METHODS: Twenty-nine consecutive patients (21 male, mean age 62.6+/-7.1 years) undergoing off pump coronary surgery were enrolled in the study. Three different surgical settings of exposure and stabilization were used according to the site of anastomosis: left anterior descending (LAD - set-up 1; n=29), posterior descending (PDA - set-up 2; n=15), and circumflex (Cx - set-up 3; n=21) coronary arteries. Haemodynamic measurements were recorded before any cardiac manipulation (baseline) in set-ups 1, 2 and 3, and immediately after the completion of each distal anastomosis with the heart returned to its anatomical position. RESULTS: There were no marked changes in heart rate (HR) and systemic mean arterial pressure during the construction of the anastomoses for any of the three surgical settings. Set-up 1 (LAD) showed a decrease of 15.5% in stroke volume (SV) and an increase of 9% in pulmonary capillary wedge pressure (PCWP) compared to baseline (both P<0.05), with all the other haemodynamic parameters remaining unchanged. Set-up 2 (PDA) showed a marked decrease in SV and cardiac index (CI), and an increase in central venous pressure (CVP) when compared to baseline (all P<0.05). The most extensive changes were observed in set-up 3 (Cx) with a considerable reduction in SV and CI, and an increase in CVP, PCWP, pulmonary arterial pressure, and systemic vascular resistance index (all P<0.05). These haemodynamic changes were transient and totally recovered after the heart was returned to its anatomical position. CONCLUSIONS: Exposure and stabilization of the three main coronary arteries during beating heart surgery does not produce any appreciable change in systemic blood pressure and HR. The haemodynamic deterioration observed during the construction of the circumflex and posterior descending coronary arteries distal anastomoses is transient and well tolerated with no adverse clinical events.

Reduced cerebral embolic signals in beating heart coronary surgery detected by transcranial Doppler ultrasound.

Cerebral emboli detected by transcranial Doppler imaging were recorded in 20 patients undergoing multiple-vessel coronary artery bypass surgery, either with or without cardiopulmonary bypass, in a prospective unblinded comparative study. Emboli were recorded continuously from the time of pericardial incision until 10 min after the last aortic instrumentation. The numbers of coronary grafts and of aortic clampings were also documented. Patients undergoing revascularization with cardiopulmonary bypass had more emboli (median 79, range 38-876) per case compared with patients having off-pump surgery (median 3, range 0-18). No clinically detectable neurological deficits were seen in either group. Beating heart surgery is associated with fewer emboli than coronary surgery with cardiopulmonary bypass. Further research is necessary to determine whether a smaller number of emboli alters the incidence of neurological deficit after cardiac surgery.

Action of repeat-induced point mutation on both strands of a duplex and on tandem duplications of various sizes in Neurospora.

In Neurospora crassa, DNA sequence duplications are detected and altered efficiently during the sexual cycle by a process known as RIP (repeat-induced point mutation). Affected sequences are subjected to multiple GC-to-AT mutations. To explore the pattern in which base changes are laid down by RIP we examined two sets of strains. First, we examined the products of a presumptive spontaneous RIP event at the mtr locus. Results of sequencing suggested that a single RIP event produces two distinct patterns of change, descended from the two strands of an affected DNA duplex. Equivalent results were obtained using an exceptional tetrad from a cross with a known duplication flanking the zeta-eta (zeta-eta) locus. The mtr sequence data were also used to further examine the basis for the differential severity of C-to-T mutations on the coding and noncoding strands in genes. The known bias of RIP toward CpA/TpG sites in conjunction with the sequence bias of Neurospora accounts for the differential effect. Finally, we used a collection of tandem repeats (from 16 to 935 bp in length) within the mtr gene to examine the length requirement for RIP. No evidence of RIP was found with duplications shorter than 400 bp while all longer tandem duplications were frequently affected. A comparison of these results with vegetative reversion data for the same duplications is consistent with the idea that reversion of long tandem duplications and RIP share a common step.