A Polynesian-specific missense CETP variant alters the lipid profile

Identifying population-specific genetic variants associated with disease and disease-predisposing traits is important to provide insights into the genetic determinants of health and disease between populations, as well as furthering genomic justice. Various common pan-population polymorphisms at CETP associate with serum lipid profiles and cardiovascular disease. Here, sequencing of CETP identified a missense variant rs1597000001 (p.Pro177Leu) specific to Māori and Pacific people that associates with higher HDL-C and lower LDL-C levels. Each copy of the minor allele associated with higher HDL-C by 0.236 mmol/L and lower LDL-C by 0.133 mmol/L. The rs1597000001 effect on HDL-C is comparable with CETP Mendelian loss-of-function mutations that result in CETP deficiency, consistent with our data, which shows that rs1597000001 lowers CETP activity by 27.9%. This study highlights the potential of population-specific genetic analyses for improving equity in genomics and health outcomes for population groups underrepresented in genomic studies.

13 EFFECTS OF PLASMA PROGESTERONE CONCENTRATIONS ON LH RELEASE AND OVULATION IN BEEF CATTLE GIVEN GnRH

Two experiments were conducted to determine the effects of plasma progesterone (P4) concentrations on LH release and ovulation in beef heifers and lactating beef cows given gonadotropin-releasing hormone (GnRH). Previously autoclaved, once-used CIDR inserts (Colazo et al. 2004 Anim. Reprod. Sci. 81, 25-34) were used for experimental purposes to induce differential plasma progesterone concentrations. In Experiment 1, postpubertal heifers received 25 mg of dinoprost i.m. (prostaglandin F (PGF); Lutalyse; Pfizer Animal Health, Montreal, Quebec, Canada). On Day 4 (estrus = Day 0), heifers were randomly assigned (10/group) to receive no treatment (control) or 1 or 2 autoclaved once-used CIDR (Pfizer Animal Health) inserts (1CIDR and 2CIDR, respectively). On Day 5, heifers in the 1CIDR group were given PGF twice 12 h apart. On Day 6, all heifers received 100 �g of GnRH i.m. (Cystorelin; Merial Canada, Inc., Victoriaville, Quebec, Canada). Once daily on Days 4 to 9, a blood sample was collected and ultrasonography was performed. On Day 6, heifers in the control (3.0 � 0.4 ng/mL; mean � SD) and 1CIDR groups (3.0 � 0.3 ng/mL) had lower (P < 0.01) plasma progesterone concentrations than those in the 2CIDR group (5.7 � 0.4 ng/mL). However, the diameter of the dominant follicle was larger (P < 0.001) in heifers in the control and 1CIDR groups than in the 2CIDR group (12.1 � 1.0, 11.5 � 0.7, and 10.1 � 0.7 mm, respectively). More (P < 0.01) heifers ovulated in response to GnRH in the control and 1CIDR groups than in the 2CIDR group (10/10, 9/10, and 3/10, respectively). In Experiment 2, ultrasound-guided follicular ablation (FA) was performed (to synchronize ovarian follicular wave emergence) 4 to 6 days after estrus in 20 postpubertal heifers and 20 mature lactating cows. Cattle were randomly and equally assigned to receive an autoclaved, once-used CIDR, either with no further treatment (High-P4) or with two PGF treatments 12 h apart (Low-P4) given after FA. All cattle received 100 �g of GnRH either 6 days after FA or the day after the dominant follicle reached 9 mm in diameter. Ultrasonography was performed daily (from 4 days after FA to ovulation or to 3 days after GnRH treatment). In three cows and three heifers per group, blood samples were collected every 30 min for 12 h after GnRH. The dominant follicle at GnRH treatment was larger in cows than heifers (11.0 � 1.1 vs. 10.3 � 0.9 mm, respectively; P = 0.05) and tended to be smaller in the High-P4 group vs. the Low-P4 group (10.3 � 1.0 vs. 11.0 � 1.0 mm; P = 0.06). Ovulatory response was not different (P = 0.9) between heifers (77.7%) and cows (78.9%), but combined for heifers and cows, was lower in High-P4 vs. Low-P4 cattle (61.1 vs. 94.7; P < 0.01). The GnRH-induced LH surge did not differ (P = 0.23) between cows and heifers, but it was lower and of shorter duration (P < 0.001) in the High-P4 group than in the Low-P4 group. In summary, higher plasma P4 concentrations resulted in decreased LH release and the proportion of cattle ovulating in response to GnRH treatment. There was no significant difference between heifers and cows in LH release or ovulatory response.

18 STRATEGIES TO IMPROVE FERTILITY WITH COSYNCH-CIDR PROTOCOLS IN BEEF CATTLE

Two experiments were designed to evaluate strategies to improve fertility with Cosynch-CIDR protocols in cattle. The first experiment investigated the effect of low levels of progesterone prior to a Cosynch-CIDR protocol. On Day 0, lactating beef cows (n = 34) and heifers (n = 37) were placed in two groups to receive 500 μg cloprostenol (PGF; Estrumate, Schering-Plough Animal Health, Pointe-Claire, Quebec, Canada) or a twice-used CIDR (Bioniche Animal Health, Belleville, Ontario, Canada) for 5 days (Pretreatment) or no treatment (Control). On Day 5, used CIDRs were removed and all cattle received a new CIDR (Pfizer Animal Health, Montreal, Quebec, Canada) and 100 μg GnRH (Cystorelin, Merial Canada Inc, Victoriaville, Quebec, Canada). On Day 12, CIDR were removed and PGF was given. A second GnRH was given concurrent with timed AI (TAI) on Day 14 (54–56 h after PGF). Cattle were examined by transrectal ultrasonography for CL and follicle development, and for confirmation of pregnancy (Days 42 to 49). Diameter of the dominant follicle on Day 5 was larger and more variable in cows than in heifers (15.5 ± 5.6 vs. 11.4 ± 3.5 mm, respectively; means, P < 0.001; variance, P < 0.003), and tended to be larger in the Pretreatment group (14.3 ± 4.9 vs. 12.6 ± 5.2 mm; P = 0.13). More Pretreated (60.0%) than Control (36.1%) cattle (P < 0.005), and more cows (64.7%) than heifers (32.4%; P < 0.03) ovulated following the first GnRH. At the time of TAI, 5 (13.5%) heifers had already ovulated (P < 0.03). Diameter of the preovulatory follicle was affected by parity (P < 0.001), but not Pretreatment (P = 0.4), and tended to be larger in heifers that became pregnant (P = 0.13). Pregnancy rate was not affected by parity (P = 0.71), or pretreatment (P = 0.34); pretreatment tended to increase pregnancy rate in heifers (63.2 vs. 38.9%; P = 0.19). The second experiment evaluated the use of eCG in a Cosynch-CIDR protocol in beef heifers. Beef heifers (n = 127) were fed 0.5 mg/head/day of MGA (Pfizer Animal Health) for 15 d; 12 d after the last feeding (designated as Day 0) heifers received a CIDR and 100 μg GnRH. On Day 7, CIDR were removed, and heifers received PGF, and were randomly placed in 2 groups to receive 300 IU of eCG (Pregnacol; Bioniche Animal Health) or no treatment (Control). On Day 9 (54–56 h after PGF), all heifers received 100 μg GnRH, concurrent with TAI. Ultrasonographic examinations were done as in the first experiment. Overall, 79.5% of the heifers had a CL, and 9.4% had a luteinized follicle on Day 0. Seventy-eight heifers (61.4%) ovulated following the first GnRH, and those that ovulated had a less variable preovulatory follicle size than those that did not (13.7 ± 1.7 vs. 13.8 ± 2.3 mm; means, P = 0.76; variance, P < 0.01). However, there was no difference in preovulatory follicle size (P = 0.63), or pregnancy rate (49.2 vs. 53.1%; P = 0.7) for eCG-treated vs. Control heifers. In summary, pretreatment with a twice-used CIDR plus PGF increased the proportion of cattle that ovulated to the first GnRH, but not preovulatory follicle size or fertility in cows; fertility tended to be improved in heifers. Treatment with eCG did not increase preovulatory follicle size or fertility in heifers subjected to an Cosynch-CIDR protocol.

13 EFFECTS OF PRESYNCHRONIZATION WITH A USED CIDR, AND TREATMENT WITH eCG ON FERTILITY IN LACTATING COWS SUBJECTED TO A COSYNCH PROTOCOL

The objectives were to investigate the effects of pretreatment with a used CIDR on follicle size and ovulation rate in cows after an injection of GnRH, and treatment with eCG at the time of PGF on preovulatory follicle size and fertility in cows subjected to a Cosynch protocol. Lactating crossbred beef cows (n = 292), 2 to 12 years of age were allocated to two groups to receive either a used CIDR (Bioniche Animal Health; Belleville, Ontario, Canada) for 15 days or no treatment (Control). At CIDR removal (Day 0), all cows received 100 μg of GnRH i.m. (Cystorelin, Merial Canada Inc., Victoriaville, Quebec, Canada). On Day 7, all cows received 500 μg of cloprostenol i.m. (PGF; Estrumate, Schering-Plough Animal Health, Pointe-Claire, Quebec, Canada) and were further allocated to receive either 400 IU of eCG i.m. (Pregnacol; Bioniche Animal Health) or no treatment (2 × 2 factorial design; n = 73 per group). On Day 9 (54 h after PGF), cows were given 100 μg of GnRH i.m., concurrent with timed AI (TAI). Transrectal ultrasonographic examinations were done on a subset of approximately 40 cows in each group on Days −15, 0, 7, and 9 to assess ovarian structures, and on all cows on Day 37 to confirm pregnancy. Data were analyzed by SAS CATMOD and ANOVA. Overall, 53% of cows had a CL present on Day −15 (P = 0.23). At first GnRH (Day 0), fewer CIDR-treated cows than Control cows had a CL (15.2 vs. 85.0%, respectively; P < 0.001), while mean (± SEM) diameters of the dominant follicle were larger in CIDR-treated cows (18.2 ± 0.4 vs. 13.8 ± 0.4 mm, respectively; P < 0.001). Moreover, the proportion of cows that ovulated following the first GnRH was higher (P < 0.001) in CIDR-treated (75.0%) than Control (48.7%) cows. Eight (10.0%) cows presynchronized with a CIDR did not ovulate and had a luteinized follicle (31.7 ± 1.9 mm) at the time of PGF. Although CIDR-treated cows had larger (P < 0.002) dominant follicles than Control cows on Day 9 (16.6 ± 0.3 vs. 15.2 ± 0.3 mm), presynchronization did not affect fertility (53.4 vs. 54.1%, respectively). However, diameter of the dominant follicle at TAI in cows that became pregnant was smaller in CIDR-treated vs. Control cows (15.3 ± 0.3 vs. 16.6 ± 0.3; P < 0.005). Treatment with eCG on Day 7 did not affect (P = 0.17) the diameter of the dominant follicle at TAI, but tended (P = 0.06) to increase pregnancy rate (58.9 vs. 48.6%). Furthermore, pregnancy rate tended to be higher (P = 0.08) in Control cows given eCG (47/73, 64.4%) than in the Control- (32/73, 43.8%), CIDR- (39/73, 53.4%) or CIDR/eCG- (39/73, 53.4%) treated cows. In addition, pregnancy rate was affected by parity; 2-yr-old cows had a lower (P < 0.04) pregnancy rate than older cows (42.9, 58.7, and 58.2% for 2, 3–4, and >5 years, respectively). Treatment with eCG increased pregnancy rate by 33% (P < 0.03) in 2-yr-old Control cows. In summary, presynchronization with a used CIDR prior to a Cosynch protocol increased the proportion of cows responding to the first GnRH. Although CIDR-treated cows had a smaller dominant follicle at TAI, pregnancy rate was not affected. Treatment with eCG increased fertility in Control cows; eCG may be useful in GnRH-based protocols in lactating beef cows.

Somatic von Hippel-Lindau mutation in clear cell papillary cystadenoma of the epididymis

Papillary cystadenoma of the epididymis is an uncommon benign lesion that may occur sporadically or as a manifestation of von Hippel-Lindau (VHL) disease. Neither immunohistochemical studies nor molecular genetic analyses of the VHL gene have been reported previously for this lesion. The authors describe two cases of clear cell papillary cystadenoma of the epididymis, both of which were initially confused with metastatic renal cell carcinoma. Both lesions showed positive immunohistochemical staining for low and intermediate molecular weight keratins (Cam 5.2 and AE1/AE3), EMA, vimentin, alpha 1-antitrypsin, and alpha 1-antichymotrypsin. Each was negative for CEA. Because clear cell papillary cystadenoma is similar to renal cell carcinoma histologically, and because both occur as components of the von Hippel-Lindau disease complex, the authors analyzed both cases for the presence of mutations in the VHL gene. A somatic VHL gene mutation was detected in one of the two tumors by polymerase chain reaction followed by single-strand conformation polymorphism analysis. Direct sequencing revealed a cytosine to thymine transition at nucleotide 694, resulting in the replacement of an arginine with a stop codon after the sixth amino acid of exon 3. As the VHL gene is believed to function as a tumor suppressor gene, VHL gene mutations may play a role in the initiation of tumorigenesis in sporadic cystadenomas of the epididymis.

Why another leaflet?

Mary Rutledge and Joanne Davis explain why they produced a leaflet to promote healthy eating to children at school. Liz Bixby describes a leaflet on bronchiolitis, which won the HVA award at this year's annual professional conference.

Detection of human papillomavirus in nongenital Bowen's disease by in situ DNA hybridization

Genital Bowen's disease has been strongly linked in recent studies to human papillomavirus (HPV). Nongenital Bowen's disease has been less well investigated, although isolated reports, all of which involved detection of HPV after extraction of DNA from fresh-frozen tissue, have been made. We investigated 25 cases of nongenital Bowen's disease in 5 black and 20 white patients for the presence of HPV types 1, 6, 11, 16, and 18 using paraffin-embedded tissues. Human papillomavirus was present in six specimens from 3 of the 5 black patients (one previously reported to be positive on Southern blot) and 3 of the 20 white patients; HPV 16 was detected in all 6 cases on low-stringency testing, but only 4 remained positive on high-stringency testing. This suggests an HPV closely related to but not entirely homologous with HPV 16 in the 2 remaining cases. Five of the 6 positive specimens were lesions from the hands and feet and 1 was from the volar aspect of the arm. Clinical factors associated with the presence of HPV included black race, location on the palmar surface and the feet, young age, and verrucous or hyperkeratotic clinical appearance. Of the 6 positive cases, all 5 of the patients available for examination also had evidence of HPV-associated genital lesions. No specific histopathologic features were found to be indicative of the presence or absence of HPV.

Eggs, serum lipids, emotional stress, and blood pressure in medical students

Emotional stress that occurred as a result of anticipation and participation in final exams did not change mean serum total cholesterol or high density lipoprotein cholesterol significantly in 26 male students who had eaten two eggs daily while maintaining a controlled diet for 12 wk. These same men continued to maintain a controlled diet but abstained from eating eggs for 12 wk which resulted in a statistically significant lower total cholesterol level at the end of 6 wk and on the day of final exams at the end of 12 wk. Mean values for high-density lipoprotein cholesterol in abstainers were significantly reduced at the end of 6 wk, but did not change further by 12 wk. Mean serum triglycerides values were variable. Blood pressures were not changed significantly.