During the luteal phase in the cow, a first-wave dominant follicle grows to reach ovulatory size,... more During the luteal phase in the cow, a first-wave dominant follicle grows to reach ovulatory size, but then ceases to grow, becomes no longer dominant and enters a phase of slow regression. During this growth transition, the concentration of oestradiol has been shown to decrease in follicular fluid. The objective of this study was to determine if follicular fluid oestradiol concentrations are regulated by the activity ofthree major steroidogenic enzymes, namely P450-aromatase (P450-arom), 3\g=b\-hydroxysteroid dehydrogenase/\g=D\5\p=n-\\g=D\4 isomerase (3\g=b\-HSD) and 17\ g=a\ \ x=r eq-\ hydroxylase C-17,20 lyase cytochrome P450 enzyme (P450\p=n-\17\g=a\) measured in granulosa and theca cells isolated from individual first-wave dominant follicles. Follicle growth and state of dominance was assessed by ultrasonography and follicles were classified as growing-dominant (GD, n=6), non-growing-dominant (NGD, n=8) or non\x=req-\ growing-non-dominant (NGND, n=6). Mean follicular fluid concentrations of oestradiol were higher in GD than in NGD or NGND follicles (511 \ m=+-\98 versus 136 \ m=+-\16 and 20 \m=+-\ 11 nmol/l respectively). Oestradiol was not correlated with P450-arom in any of the three groups. In GD follicles, oestradiol was positively correlated with pregnenolone concentration but neither was correlated with granulosa or theca 3\g=b\-HSDactivity or with theca P450\p=n-\17\g=a\ activity. In NGD follicles, oestradiol was negatively correlated with theca 3\g=b\-HSDactivity and pregnenolone was negatively correlated with granulosa 3\g=b\-HSDactivity. In NGND follicles, oestradiol was positively correlated, and pregnenolone was negatively correlated with theca 3\g=b\-HSD and P450\p=n-\17\g=a\activities. These studies demonstrated that pregnenolone supply is the principal regulating factor of oestradiol output during follicle dominance and during the loss of dominance but that the levels of P450\p=n-\17\g=a\ and 3\g=b\-HSDactivity become rate-limiting when the follicle is no longer dominant.
The Canadian veterinary journal. La revue vétérinaire canadienne, 1984
A twelve month old, noncycling Holstein-Friesian heifer, was examined because of abnormal udder d... more A twelve month old, noncycling Holstein-Friesian heifer, was examined because of abnormal udder development. Rectal palpation revealed a tense right uterine horn. A solid mass in the right abdomen was detected by ballottement. A granulosa cell tumor of the right ovary was removed and nine months later the animal conceived.
To mimic the abnormal patterns of follicular growth in the early post-partum period, heifers were... more To mimic the abnormal patterns of follicular growth in the early post-partum period, heifers were injected with 15 mg oestradiol and 37•5 mg progesterone every 12 h for 7 days starting on day 15 of the oestrous cycle. Control and treated animals (no. = 8 per group) were monitored by daily ultrasonography and plasma hormone measurements. Five treated animals had quiescent ovaries for 11 days during which period oestradiol concentrations exceeded 30 pg/ml. After this, the first post-treatment follicular wave produced a normal ovulatory follicle. The other three heifers had quiescent ovaries for 17 days during exposure to high oestradiol values but this was followed by the formation of persistent follicles. The prolonged exposure to oestradiol probably disrupted normal LH surges in the latter animals. Growth rates and internal diameters for normal, ovulatory and prolonged persistent follicles were similar for the first 6 days after emergence, but the persistent follicles grew larger (P...
The aims of this study were to expose dominant ovarian follicles at the end of the oestrous cycle... more The aims of this study were to expose dominant ovarian follicles at the end of the oestrous cycle to low progesterone concentrations similar to those that occur during stress, and to examine the effect of a subsequent small increase in progesterone 10 days later. Half a progesterone releasing intravaginal device (0.5 PRID) was administered to 13 heifers from day 15 of the oestrous cycle. In group 1 (n = 7), one 0.5 PRID remained in place until day 40 or until each heifer ovulated. In group 2 (n = 6), the first 0.5 PRID was removed on day 28, and replaced immediately with a second 0.5 PRID. Ultra-sonography and blood collection (10 ml) were conducted each day for 26 days from day 14 and then on alternate days. The largest follicle that emerged during the first 5 days after insertion of the initial 0.5 PRID remained > 10 mm in diameter for 15.3 +/- 1.7 and 11.6 +/- 0.4 days in groups 1 and 2, respectively. This period of dominance, during which no other follicles emerged, was close...
Canadian journal of veterinary research = Revue canadienne de recherche vétérinaire, 1989
The effect of early pregnancy failure on the release of prostaglandin F2 alpha (PGF2 alpha) in re... more The effect of early pregnancy failure on the release of prostaglandin F2 alpha (PGF2 alpha) in response to oxytocin (Ot) was examined in an abnormal breeder (AB) heifer that was not able to maintain a pregnancy beyond 21 days. This animal was used in three experiments: 1) She received one intravenous injection of 100 IU Ot 17 days after the onset of oestrus (Day 0). Frequent blood samples were taken for the measurement of 15-keto-13,14-dihydro-PGF2 alpha (PGFM) by radioimmunoassay. Daily samples for progesterone (P4) determinations were taken to monitor luteal function. This was then repeated using the same animal at either day 17 or 18 or 19 (day 17-19) of pregnancy. 2) Embryos from superovulated normal breeder (NB) donors were transferred at day 7 to the AB heifer as well as to NB control animals. 3) Seven day old embryos from the superovulated AB heifer were transferred to NB recipient animals. At day 17-19 of pregnancy all the recipient heifers (experiments 2 and 3) were subject...
The influence of pregnancy on PGF2c ~ secretion in cattle. 1. Concentrations of 15-keto-13,1#-dih... more The influence of pregnancy on PGF2c ~ secretion in cattle. 1. Concentrations of 15-keto-13,1#-dihydro-prostaglandin F2c z and progesterone in peripheral blood of recipients of transferred embryos. Anita. Reprod. Sci., 7: 195-216.
The Canadian veterinary journal. La revue vétérinaire canadienne, 1987
BOVINE HERPETIC MAMMILLITIS IN QUEBEC: Bovine herpetic mammillitis is reported for the first time... more BOVINE HERPETIC MAMMILLITIS IN QUEBEC: Bovine herpetic mammillitis is reported for the first time in Canada. It is a vesicular and ulcerative skin disease affecting the udder and teats of cows. It is caused by the bovine herpesvirus 2. The principal lesions consist of crusts that are found on the teats and may become complicated by secundary bacterial infection.Specimens collected from the lesions were used to differentiate the condition from pseudo-cowpox by serological tests, virus isolation and electron microscopy. Bovine herpetic mammillitis causes painful and therefore difficult milking which is followed by mastitis and an increased rate of culling.
Les défis pédagogiques que doivent relever les universités sont majeurs et incontournables. L’exp... more Les défis pédagogiques que doivent relever les universités sont majeurs et incontournables. L’exposé magistral avec tous ses attraits « administratifs » et ses lacunes pédagogiques reste pour le moment l’approche dominante en pédagogie universitaire. Les nouvelles technologies de l’information et des communications (NTIC) offrent des avantages pédagogiques indéniables, mais souffrent aussi de certaines faiblesses qu’il est essentiel de connaître si l’on veut pouvoir en prescrire efficacement l’utilisation. Il est aussi urgent que les universités mettent en place les infrastructures humaines et matérielles nécessaires à l’implantation et au développement des NTIC « pédagogiques » dans ces institutions.
Teaching methods that provide an opportunity for individual engagement and focussed feedback are ... more Teaching methods that provide an opportunity for individual engagement and focussed feedback are required to create an active learning environment for case-based teaching in large groups. A prospective observational controlled study was conducted to evaluate whether the use of an audience response system (ARS) would promote an active learning environment during case-based discussions in large groups, have an impact on student motivation and improve long-term retention. Group A (N = 83) participated in large group case discussions where student participation was voluntary, while for group B (N = 86) an ARS was used. Data collection methods included student and teacher surveys, student focus group interviews, independent observations and 1-year post-course testing. Results indicated that the use of an ARS provided an active learning environment during case-based discussions in large groups by favouring engagement, observation and critical reflection and by increasing student and teacher motivation. Although final exam results were significantly improved in group B, long-term retention was not significantly different between groups. It was concluded that ARS use significantly improved the learning experience associated with case-based discussions in a large group of undergraduate students.
Journal of Continuing Education in the Health Professions, 2001
Every continuing medical education (CME) provider is confronted one day or another with deciding ... more Every continuing medical education (CME) provider is confronted one day or another with deciding whether to develop distance education programs that may enhance access to CME for health professionals. To make a judicious decision, one needs to understand the features of distance education and the experiences of other providers. Since there was a lack of information in the literature regarding the actual state of distance CME in North America, a Web-based survey aimed at CME providers was conducted including a description of the providers, the users, the activities offered, the technologies employed, and the administration of the systems. The results from this study indicate that the majority (68%) of CME providers had not developed distance education programs at the time of the survey; 30% of the providers, mainly from private companies, were offering nondegree distance education programs, and 2% of the university providers were offering degree programs. The technologies mainly used to develop distance education programs were printed material (69%), videoconferencing (58%), and, to a lesser degree, videotape. The revenue sources to develop degree programs were government funding, tuition, and fees. Other sources such as commercial support and sales were used for nondegree programs. This study revealed that there was considerable interest in distance education, especially from the organizations not offering this type of program. Since distance CME features are now better known, this is a step toward the advancement and development of more and better distance education programs.
Few studies have verified the validity of behavioral and physiological methods of pain assessment... more Few studies have verified the validity of behavioral and physiological methods of pain assessment in cattle. This prospective, blinded, randomized controlled experimental study aimed to validate different methods of pain assessment during acute and chronic (up to 21 d postintervention) conditions in dairy cattle, in response to 3 analgesic treatments for traumatic reticuloperitonitis. Cerebrospinal fluid (CSF) biomarkers and mechanical sensitization were measured as indicators of centralized pain. Proteomics in the CSF were examined to detect specific (to pain intensity) and sensitive (responsive to analgesia) markers. Recordings of spontaneous behavior with video analysis, telemetered motor activity, pain scales, electrodermal activity, and plasma cortisol concentration were quantified at regular intervals. Cows were assigned to group 1 (n = 4, standard control receiving aspirin), group 2 (n = 5, test group receiving preemptive tolfenamic acid), or group 3 (n = 3, positive control receiving preemptive multimodal analgesia composed of epidural morphine, plus tolfenamic acid and butorphanol). Rescue analgesia was administered as needed. Generalized estimating equations tested group differences and the influence of rescue analgesia on the measurements. All 3 groups demonstrated a long-term decrease in a CSF protein identified as transthyretin. The decrease in transthyretin expression inversely correlated with the expected level of analgesia (group 1 < 2 < 3). Moreover, in group 1, CSF noradrenaline decreased long term, cows were hypersensitive to mechanical stimulation, and they demonstrated signs of discomfort with higher motor activity and "agitation while lying" recorded from video analysis. Decreased "feeding behavior," observer-reported pain scales, electrodermal activity, and plasma cortisol concentration were inconsistent to differentiate pain intensity between groups. In summary, changes in CSF biomarkers and mechanical sensitization reflected modulation of central pain in dairy cows. The spontaneous behavior "agitation while lying" was the only behavioral outcome validated for assessing acute and chronic pain in this visceral pain model.
During the luteal phase in the cow, a first-wave dominant follicle grows to reach ovulatory size,... more During the luteal phase in the cow, a first-wave dominant follicle grows to reach ovulatory size, but then ceases to grow, becomes no longer dominant and enters a phase of slow regression. During this growth transition, the concentration of oestradiol has been shown to decrease in follicular fluid. The objective of this study was to determine if follicular fluid oestradiol concentrations are regulated by the activity ofthree major steroidogenic enzymes, namely P450-aromatase (P450-arom), 3\g=b\-hydroxysteroid dehydrogenase/\g=D\5\p=n-\\g=D\4 isomerase (3\g=b\-HSD) and 17\ g=a\ \ x=r eq-\ hydroxylase C-17,20 lyase cytochrome P450 enzyme (P450\p=n-\17\g=a\) measured in granulosa and theca cells isolated from individual first-wave dominant follicles. Follicle growth and state of dominance was assessed by ultrasonography and follicles were classified as growing-dominant (GD, n=6), non-growing-dominant (NGD, n=8) or non\x=req-\ growing-non-dominant (NGND, n=6). Mean follicular fluid concentrations of oestradiol were higher in GD than in NGD or NGND follicles (511 \ m=+-\98 versus 136 \ m=+-\16 and 20 \m=+-\ 11 nmol/l respectively). Oestradiol was not correlated with P450-arom in any of the three groups. In GD follicles, oestradiol was positively correlated with pregnenolone concentration but neither was correlated with granulosa or theca 3\g=b\-HSDactivity or with theca P450\p=n-\17\g=a\ activity. In NGD follicles, oestradiol was negatively correlated with theca 3\g=b\-HSDactivity and pregnenolone was negatively correlated with granulosa 3\g=b\-HSDactivity. In NGND follicles, oestradiol was positively correlated, and pregnenolone was negatively correlated with theca 3\g=b\-HSD and P450\p=n-\17\g=a\activities. These studies demonstrated that pregnenolone supply is the principal regulating factor of oestradiol output during follicle dominance and during the loss of dominance but that the levels of P450\p=n-\17\g=a\ and 3\g=b\-HSDactivity become rate-limiting when the follicle is no longer dominant.
The Canadian veterinary journal. La revue vétérinaire canadienne, 1984
A twelve month old, noncycling Holstein-Friesian heifer, was examined because of abnormal udder d... more A twelve month old, noncycling Holstein-Friesian heifer, was examined because of abnormal udder development. Rectal palpation revealed a tense right uterine horn. A solid mass in the right abdomen was detected by ballottement. A granulosa cell tumor of the right ovary was removed and nine months later the animal conceived.
To mimic the abnormal patterns of follicular growth in the early post-partum period, heifers were... more To mimic the abnormal patterns of follicular growth in the early post-partum period, heifers were injected with 15 mg oestradiol and 37•5 mg progesterone every 12 h for 7 days starting on day 15 of the oestrous cycle. Control and treated animals (no. = 8 per group) were monitored by daily ultrasonography and plasma hormone measurements. Five treated animals had quiescent ovaries for 11 days during which period oestradiol concentrations exceeded 30 pg/ml. After this, the first post-treatment follicular wave produced a normal ovulatory follicle. The other three heifers had quiescent ovaries for 17 days during exposure to high oestradiol values but this was followed by the formation of persistent follicles. The prolonged exposure to oestradiol probably disrupted normal LH surges in the latter animals. Growth rates and internal diameters for normal, ovulatory and prolonged persistent follicles were similar for the first 6 days after emergence, but the persistent follicles grew larger (P...
The aims of this study were to expose dominant ovarian follicles at the end of the oestrous cycle... more The aims of this study were to expose dominant ovarian follicles at the end of the oestrous cycle to low progesterone concentrations similar to those that occur during stress, and to examine the effect of a subsequent small increase in progesterone 10 days later. Half a progesterone releasing intravaginal device (0.5 PRID) was administered to 13 heifers from day 15 of the oestrous cycle. In group 1 (n = 7), one 0.5 PRID remained in place until day 40 or until each heifer ovulated. In group 2 (n = 6), the first 0.5 PRID was removed on day 28, and replaced immediately with a second 0.5 PRID. Ultra-sonography and blood collection (10 ml) were conducted each day for 26 days from day 14 and then on alternate days. The largest follicle that emerged during the first 5 days after insertion of the initial 0.5 PRID remained > 10 mm in diameter for 15.3 +/- 1.7 and 11.6 +/- 0.4 days in groups 1 and 2, respectively. This period of dominance, during which no other follicles emerged, was close...
Canadian journal of veterinary research = Revue canadienne de recherche vétérinaire, 1989
The effect of early pregnancy failure on the release of prostaglandin F2 alpha (PGF2 alpha) in re... more The effect of early pregnancy failure on the release of prostaglandin F2 alpha (PGF2 alpha) in response to oxytocin (Ot) was examined in an abnormal breeder (AB) heifer that was not able to maintain a pregnancy beyond 21 days. This animal was used in three experiments: 1) She received one intravenous injection of 100 IU Ot 17 days after the onset of oestrus (Day 0). Frequent blood samples were taken for the measurement of 15-keto-13,14-dihydro-PGF2 alpha (PGFM) by radioimmunoassay. Daily samples for progesterone (P4) determinations were taken to monitor luteal function. This was then repeated using the same animal at either day 17 or 18 or 19 (day 17-19) of pregnancy. 2) Embryos from superovulated normal breeder (NB) donors were transferred at day 7 to the AB heifer as well as to NB control animals. 3) Seven day old embryos from the superovulated AB heifer were transferred to NB recipient animals. At day 17-19 of pregnancy all the recipient heifers (experiments 2 and 3) were subject...
The influence of pregnancy on PGF2c ~ secretion in cattle. 1. Concentrations of 15-keto-13,1#-dih... more The influence of pregnancy on PGF2c ~ secretion in cattle. 1. Concentrations of 15-keto-13,1#-dihydro-prostaglandin F2c z and progesterone in peripheral blood of recipients of transferred embryos. Anita. Reprod. Sci., 7: 195-216.
The Canadian veterinary journal. La revue vétérinaire canadienne, 1987
BOVINE HERPETIC MAMMILLITIS IN QUEBEC: Bovine herpetic mammillitis is reported for the first time... more BOVINE HERPETIC MAMMILLITIS IN QUEBEC: Bovine herpetic mammillitis is reported for the first time in Canada. It is a vesicular and ulcerative skin disease affecting the udder and teats of cows. It is caused by the bovine herpesvirus 2. The principal lesions consist of crusts that are found on the teats and may become complicated by secundary bacterial infection.Specimens collected from the lesions were used to differentiate the condition from pseudo-cowpox by serological tests, virus isolation and electron microscopy. Bovine herpetic mammillitis causes painful and therefore difficult milking which is followed by mastitis and an increased rate of culling.
Les défis pédagogiques que doivent relever les universités sont majeurs et incontournables. L’exp... more Les défis pédagogiques que doivent relever les universités sont majeurs et incontournables. L’exposé magistral avec tous ses attraits « administratifs » et ses lacunes pédagogiques reste pour le moment l’approche dominante en pédagogie universitaire. Les nouvelles technologies de l’information et des communications (NTIC) offrent des avantages pédagogiques indéniables, mais souffrent aussi de certaines faiblesses qu’il est essentiel de connaître si l’on veut pouvoir en prescrire efficacement l’utilisation. Il est aussi urgent que les universités mettent en place les infrastructures humaines et matérielles nécessaires à l’implantation et au développement des NTIC « pédagogiques » dans ces institutions.
Teaching methods that provide an opportunity for individual engagement and focussed feedback are ... more Teaching methods that provide an opportunity for individual engagement and focussed feedback are required to create an active learning environment for case-based teaching in large groups. A prospective observational controlled study was conducted to evaluate whether the use of an audience response system (ARS) would promote an active learning environment during case-based discussions in large groups, have an impact on student motivation and improve long-term retention. Group A (N = 83) participated in large group case discussions where student participation was voluntary, while for group B (N = 86) an ARS was used. Data collection methods included student and teacher surveys, student focus group interviews, independent observations and 1-year post-course testing. Results indicated that the use of an ARS provided an active learning environment during case-based discussions in large groups by favouring engagement, observation and critical reflection and by increasing student and teacher motivation. Although final exam results were significantly improved in group B, long-term retention was not significantly different between groups. It was concluded that ARS use significantly improved the learning experience associated with case-based discussions in a large group of undergraduate students.
Journal of Continuing Education in the Health Professions, 2001
Every continuing medical education (CME) provider is confronted one day or another with deciding ... more Every continuing medical education (CME) provider is confronted one day or another with deciding whether to develop distance education programs that may enhance access to CME for health professionals. To make a judicious decision, one needs to understand the features of distance education and the experiences of other providers. Since there was a lack of information in the literature regarding the actual state of distance CME in North America, a Web-based survey aimed at CME providers was conducted including a description of the providers, the users, the activities offered, the technologies employed, and the administration of the systems. The results from this study indicate that the majority (68%) of CME providers had not developed distance education programs at the time of the survey; 30% of the providers, mainly from private companies, were offering nondegree distance education programs, and 2% of the university providers were offering degree programs. The technologies mainly used to develop distance education programs were printed material (69%), videoconferencing (58%), and, to a lesser degree, videotape. The revenue sources to develop degree programs were government funding, tuition, and fees. Other sources such as commercial support and sales were used for nondegree programs. This study revealed that there was considerable interest in distance education, especially from the organizations not offering this type of program. Since distance CME features are now better known, this is a step toward the advancement and development of more and better distance education programs.
Few studies have verified the validity of behavioral and physiological methods of pain assessment... more Few studies have verified the validity of behavioral and physiological methods of pain assessment in cattle. This prospective, blinded, randomized controlled experimental study aimed to validate different methods of pain assessment during acute and chronic (up to 21 d postintervention) conditions in dairy cattle, in response to 3 analgesic treatments for traumatic reticuloperitonitis. Cerebrospinal fluid (CSF) biomarkers and mechanical sensitization were measured as indicators of centralized pain. Proteomics in the CSF were examined to detect specific (to pain intensity) and sensitive (responsive to analgesia) markers. Recordings of spontaneous behavior with video analysis, telemetered motor activity, pain scales, electrodermal activity, and plasma cortisol concentration were quantified at regular intervals. Cows were assigned to group 1 (n = 4, standard control receiving aspirin), group 2 (n = 5, test group receiving preemptive tolfenamic acid), or group 3 (n = 3, positive control receiving preemptive multimodal analgesia composed of epidural morphine, plus tolfenamic acid and butorphanol). Rescue analgesia was administered as needed. Generalized estimating equations tested group differences and the influence of rescue analgesia on the measurements. All 3 groups demonstrated a long-term decrease in a CSF protein identified as transthyretin. The decrease in transthyretin expression inversely correlated with the expected level of analgesia (group 1 < 2 < 3). Moreover, in group 1, CSF noradrenaline decreased long term, cows were hypersensitive to mechanical stimulation, and they demonstrated signs of discomfort with higher motor activity and "agitation while lying" recorded from video analysis. Decreased "feeding behavior," observer-reported pain scales, electrodermal activity, and plasma cortisol concentration were inconsistent to differentiate pain intensity between groups. In summary, changes in CSF biomarkers and mechanical sensitization reflected modulation of central pain in dairy cows. The spontaneous behavior "agitation while lying" was the only behavioral outcome validated for assessing acute and chronic pain in this visceral pain model.
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Papers by Denis Harvey