Decision-making in breast cancer screening: A qualitative exploration of the match between women's beliefs and screening information in the Netherlands

OBJECTIVE

Decision-making about breast cancer screening requires balanced and understandable information that takes prior beliefs of screening invitees into account.

METHODS

In qualitative interviews with 22 Dutch women who were invited for screening for the first time (49-52 years of age, varying health literacy levels), we gained insight in their beliefs on breast cancer and breast cancer screening, and explored how the current screening information matched these beliefs.

RESULTS

Breast cancer was perceived as an unpredictable, severe, and uncontrollable disease. Women considered screening as self-evident and an important mean to gain some control over breast cancer. Information on benefits of screening was in line with women's prior beliefs and confirmed women's main reasons to participate. Information about false-positive outcomes, overtreatment, and false negative outcomes did not correspond to women's prior beliefs and this information was generally not considered relevant for decision-making. Preferences for additional information merely concerned practical information on the screening procedure.

CONCLUSION

Complex information on the harms of screening does not match women's beliefs and is not taken into account in their decision-making.

PRACTICE IMPLICATIONS

Information regarding breast cancer screening could be further aligned to prior beliefs by taking into account values, filling knowledge gaps and correct misconceptions.

Exploring vaginal discharge scoring to assess clinical metritis severity: Comparison between intrauterine dextrose and systemic antibiotics treatments

The objectives of this study were to assess: 1) differences in the metabolic status, systemic inflammation, daily milk yield, and daily rumination time between Holstein dairy cows with different vaginal discharge scores (VDS) in the first 7±3 DIM, and 2) effects of intrauterine dextrose infusion on metabolic status, systemic inflammation, daily milk yield and daily rumination time in dairy cows with VDS4 and VDS5. Cows (n=641) from a farm located in central Pennsylvania were screened at 7±3 DIM (study d 0) to assess vaginal discharge scores. Vaginal discharge was scored using a five-point scale (i.e., 1- clear fluid, 2- <50% white purulent fluid, 3- >50% white purulent fluid, 4- red-brownish fluid without fetid smell, and 5- fetid red-brownish watery fluid). Cows with VDS4 and VDS5 were blocked by parity and randomly assigned to one of two treatment groups: 1) CONV (VDS4 n=15; VDS5 n= 23): two injections of ceftiofur (per label; 6.6 mg/Kg) 72 h apart; and 2) DEX (VDS4 n=15; VDS5 n=22): three intrauterine infusions of a 50% dextrose solution (1 L/cow) every 24 h. Cows that presented a VDS 1, 2, and 3 were categorized as normal vaginal discharge animals (NOMVDS; n=35) and were randomly selected and matched by parity to CONV and DEX cows. Daily milk yield and rumination time for the first 150 DIM were collected from on-farm computer records. Blood samples were collected to assess haptoglobin (HP) and β-hydroxybutyrate (BHB) concentrations at study d 0, d 7, and d 14 relative to enrollment. Subclinical ketosis was defined as having a BHB concentration >1.2 mmol/dL at any of the sampling points. The data were analyzed using the MIXED and GLIMMIX procedures of SAS as a randomized complete block design. When comparing cows with different VDS (i.e., NOMVDS, VDS4, VDS5) separately, cows with VDS5 had the highest concentration of HP at enrollment compared to cows with VDS4 and NOMVDS; however, cows with VDS4 had higher concentrations of HP compared to cows with NOMVDS. Cows with VDS4 or VDS5 had a higher incidence of subclinical ketosis compared to cows with NOMVDS (p=0.005; VDS4= 62.08±9.16%; VDS5=74.44±6.74%; NOMVDS=34.36±8.53%). Similarly, daily milk yield (p<.0001; VDS4=30.17±1.32 kg/d; VDS5=27.40±1.27 kg/d; NOMVDS=35.14±1.35 kg/d) and daily rumination time (p=0.001; VDS4=490.77±19.44 min; VDS5=465±16.67 min; NOMVDS=558.29±18.80 min) was lower for cows with VDS4 and VDS5 compared to cows with NOMVDS at 7±3 days in milk. When analyzing HP concentration between treatment groups in cows with VDS4 (p=0.70), VDS5 (p=0.25), or VDS4 and VDS5 combined (p=0.31), there was no difference in HP concentration by study d 14 between treatment groups. Interestingly, when only cows with VDS4 were considered for treatment, both treatments, DEX and CONV, increased the daily milk yield to the levels of NOMVDS cows by 14 days in milk. On the other hand, when only cows with VDS5 were considered for treatment, cows treated with DEX produced, on average, 4.48 kg/d less milk in the first 150 days in milk compared to cows treated with CONV or cows that had NOMVDS. Similarly, when cows with either VDS4 or VDS5 were considered for treatment, DEX treatment also impaired milk yield. These results suggest that cows with either VDS 4 or 5 have an altered inflammatory status, and decreased milk yield and rumination compared to cows with NOMVDS. Furthermore, DEX treatment may have similar effects on daily milk yield and metabolic status compared to CONV in cows with VDS4, while DEX is not recommended for cows with VDS5.

The protective effects of hormonal suppression by a gonadotropin-releasing hormone agonist or an oral contraceptive on the decreased ovarian reserve in female rats exposed to isotretinoin

OBJECTIVE

The objective of our study was to evaluate whether ovarian suppression by two different hormonal methods may spare the ovary the cytotoxic effects of isotretinoin in a rat model.

MATERIALS AND METHODS

Four groups (n=8 Sprague-Dawley albino rats per group) were studied: control (Group I), 7.5 mg/kg/day isotretinoin (Group II), isotretinoin plus the combination of 0.030 mg ethinyl estradiol/0.15 mg levonorgestrel (combined oral contraceptive, COC), and isotretinoin plus 100 μg (microgram) leuprolide acetate (GnRHa) (Group III and IV, respectively). Four rats from each group were decapitated on the 30th day of treatment, and the remaining rats were decapitated on the 30th day of untreated follow-up. Serum anti-Mullerian hormone (AMH) concentrations, healthy and atretic follicle numbers, and apoptotic activity of follicles in oophorectomy specimens were compared between the groups.

RESULTS

There were no significant differences in AMH levels among the study groups before, immediately after (first month), and one month after their last medication (second month) (p=0.08, 0.47, and 0.08, respectively). At the end of the first month, the control group had a higher median count of healthy primordial follicles compared to the study groups: 13.5 (8-22), 5.5 (3-11), 6 (2-13), and 1 (0-1) in control, isotretinoin, isotretinoin+COC, and isotretinoin+GnRHa groups, respectively (p=0.02). However, there was no statistically significant difference in the number of healthy primordial follicles between the groups one month after the last medication (p=0.33). The median atretic antral follicle counts in the first month were 2 (1-4), 3.5 (1-4), 0 (0-2), and 0 (0-0) in the control, isotretinoin, isotretinoin+COC, and isotretinoin+GnRHa groups, respectively (p=0.02). Otherwise, there were no significant differences in other types of follicles among the control and treated groups (p>0.05). There was also no statistical difference between the groups regarding immunostaining intensity for active caspase-3 evaluated in the first or second month of treatment (p=0.8 and 0.2, respectively).

CONCLUSIONS

Our results show that GnRH agonists or COC have no protective effects on ovarian reserve when co-administered with isotretinoin in the rat model.

Acceptability of risk-based triage in cervical cancer screening: A focus group study

BACKGROUND

Compared to the previous cytology-based program, the introduction of primary high-risk human papillomavirus (hrHPV) based screening in 2017 has led to an increased number of referrals. To counter this, triage of hrHPV-positive women in cervical cancer screening can potentially be optimized by taking sociodemographic and lifestyle risk factors for cervical abnormalities into account. Therefore, it is essential to gain knowledge of the views of women (30-60 years) eligible for cervical cancer screening.

OBJECTIVE

The main goal of this qualitative study was to gain insight in the aspects that influence acceptability of risk-based triage in cervical cancer screening.

DESIGN

A focus group study in which participants were recruited via four general medical practices, and purposive sampling was used to maximize heterogeneity with regards to age, education level, and cervical cancer screening experiences.

APPROACH

The focus group discussions were transcribed verbatim and analyzed using reflexive thematic analysis.

PARTICIPANTS

A total of 28 women (average age: 45.2 years) eligible for cervical cancer screening in The Netherlands participated in seven online focus group discussions. Half of the participants was higher educated, and the participants differed in previous cervical cancer screening participation and screening result.

KEY RESULTS

In total, 5 main themes and 17 subthemes were identified that determine the acceptability of risk-stratified triage. The main themes are: 1) adequacy of the screening program: an evidence-based program that is able to minimize cancer incidence and reduce unnecessary referrals; 2) personal information (e.g., sensitive topics and stigma); 3) emotional impact: fear and reassurance; 4) communication (e.g., transparency); and 5) autonomy (e.g., prevention).

CONCLUSION

The current study highlights several challenges regarding the development and implementation of risk-based triage that need attention in order to be accepted by the target group. These challenges include dealing with sensitive topics and a transparent communication strategy.

Dutch individuals' views of screening for oesophageal cancer: a focus group study

OBJECTIVE

Screening for early oesophageal adenocarcinoma (OAC), including its precursor Barrett's oesophagus (BO), can potentially reduce OAC-related morbidity and mortality. This study explores Dutch at-risk individuals' views of screening an at-risk population for BO/OAC.

DESIGN

We invited 372 individuals with risk factors for OAC from primary care practices, 73 individuals with surveillance experience, and 221 participants of previous studies (BO/OAC screening trial or survey) to participate in focus groups. Transcripts were inductively and thematically analysed by two independent researchers.

RESULTS

A total of 50 individuals (42% with gastro-oesophageal reflux symptoms) of 50-75 years participated. Themes that were raised included: theme 1 'screening intentions' describing participants' motivation to be screened (eg, early diagnosis, potential reassurance, physician recommendation, and knowing someone with cancer) or decline screening (eg, anticipated discomfort or suboptimal accuracy of the test); theme 2 'risk-based eligibility' describing the tension between effectiveness (eg, targeting high-risk individuals) and inclusivity (eg, making screening available for everyone); theme 3 'distributive justice', in which the pressure of a potential new screening programme on healthcare resources was discussed; and theme 4 'information needs' describing the perceived lack of information access and individuals' preference to discuss screening with their general practitioner.

CONCLUSION

Individuals not only expressed high willingness to be screened but also voiced the concern that a new screening programme may pressure limited healthcare resources. If implemented, it is crucial to develop educational materials that meet the public's information needs and explain the test procedures and eligibility criteria while avoiding stigmatising language.

Postpartum intrauterine dextrose infusion: Effects on uterine health, metabolic stress, systemic inflammation, and daily milk yield in clinically healthy dairy cows

The objective of this study was to assess the effect of intrauterine dextrose infusion at 4 ± 1 d in milk (DIM) on the incidence of clinical metritis (CM), metabolic stress [i.e., body condition score (BCS), β-hydroxybutyrate (BHB) concentration, and subclinical ketosis incidence], systemic inflammation (i.e., haptoglobin concentration), and daily milk yield in clinically healthy postpartum dairy cows. Cows (n = 245) from a dairy farm located in southwest Pennsylvania were screened at 4 ± 1 DIM using a Metricheck (Simcro Tech Ltd.) device to assess vaginal discharge. In addition, overall cow health (e.g., lameness, abnormal breathing) and rectal temperature were assessed at this time. Cows (n = 134) that presented a clear dense vaginal discharge, were in clinically good health status, and had a normal rectal temperature (i.e., <39.7°C) were blocked by parity (primiparous = 64; multiparous = 70) and randomly assigned to 1 of 3 groups: (1) SAL (n = 45): 1 intrauterine infusion of isotonic saline solution (1 L/cow); (2) DEX (n = 44): 1 intrauterine infusion of a 50% dextrose solution (1 L/cow), or (3) CON (n = 45): cows remained untreated. Cows were re-screened at 7 d after enrollment (11 ± 1 DIM) using the Metricheck device to assess CM incidence (research clinical metritis incidence; RCMI). On-farm computer records (i.e., Dairycomp 305) were also used to collect clinical metritis incidence (farm clinical metritis incidence; FCMI). In addition, BCS was assessed and blood samples were collected at enrollment and at study d 7, 14, and 21. Furthermore, daily milk yield and clinical disease events for the first 60 DIM were collected from on-farm computer records. The data were analyzed using the MIXED and GLIMMIX procedures of SAS (SAS Institute Inc.) as a randomized complete block design. Although not significant, the RCMI and FCMI in DEX and SAL cows were on average 14.5 and 18.1 percentage points higher, respectively, compared with CON cows. The SAL cows had higher BHB and haptoglobin concentrations and higher incidence of subclinical ketosis compared with CON cows on study d 7. With regard to daily milk yield, there was a day by treatment interaction, where CON cows produced more milk on certain days compared with DEX and SAL cows. Based on these findings, authors conclude that intrauterine dextrose infusion in clinically healthy postpartum cows with normal vaginal discharge may be prejudicial for cow health and performance.

Adherence to dietary guidelines and cognitive decline from middle age: the Doetinchem Cohort Study

BACKGROUND

Diet, in particular the Mediterranean diet, has been associated with better cognitive function and less cognitive decline in older populations.

OBJECTIVES

To quantify associations of a healthy diet, defined by adherence to either the Mediterranean diet, the WHO guidelines, or Dutch Health Council dietary guidelines, with cognitive function and cognitive decline from middle age into old age.

METHODS

From the Doetinchem Cohort Study, a large population-based longitudinal study, 3644 participants (51% females) aged 45-75 y at baseline, were included. Global cognitive function, memory, processing speed, and cognitive flexibility were assessed at 5-y time intervals up to 20-y follow-up. Adherence to the Mediterranean diet was measured with the modified Mediterranean Diet Score (mMDS), adherence to the WHO dietary guidelines with the Healthy Diet Indicator (HDI), and adherence to the Dutch Health Council dietary guidelines 2015 with the modified Dutch Healthy Diet 2015 index (mDHD15-index). The scores on the dietary indices were classified in tertiles (low, medium, high adherence). Linear mixed models were used to model level and change in cognitive function by adherence to healthy diets.

RESULTS

The highest tertiles of the mMDS, HDI, and mDHD15-index were associated with better cognitive function compared with the lowest tertiles (P values <0.01), for instance at age 65 y equal to being 2 y cognitively younger in global cognition. In addition, compared with the lowest tertiles, the highest tertiles of the mMDS, HDI, and mDHD15-index were statistically significantly associated with 6-7% slower global cognitive decline from age 55 to 75 y, but also slower decline in processing speed (for mMDS: 10%; 95% CI: 2, 18%; for mDHD15: 12%; 95% CI: 6, 21%) and cognitive flexibility (for mDHD15: 10%; 95% CI: 4, 18%).

CONCLUSIONS

Healthier dietary habits, determined by higher adherence to dietary guidelines, are associated with better cognitive function and slower cognitive decline with aging from middle age onwards.

Effects of postpartum acetylsalicylic acid on uterine diseases and reproductive performance in dairy cattle

Uterine diseases are some of the most prevalent and costly diseases for the dairy industry. It has been reported that an exacerbated and prolonged inflammatory response around calving can increase the risk of developing metritis, which subsequently can impair production and fertility in dairy cows. The objective of this study was to assess the effects of 2 oral administrations of acetylsalicylic acid 24 h apart on the incidence of uterine diseases [i.e., retained fetal membranes, clinical metritis, clinical endometritis) and reproductive performance [i.e., days in milk to conception, number of services to conception, proportion of cows pregnant at first service, proportion of abortion at first service (ABRT)] in dairy cows after calving. Cows from one dairy farm (n = 246) located in central Pennsylvania were included in this study. Animals were blocked by parity and randomly assigned to 1 of 2 groups: (1) ASA (n = 121): within ~12 h after parturition, cows received 2 treatments with acetylsalicylic acid (ASA; 200 mg/kg, 4 boluses) 24 h apart; or (2) UNT (n = 125): cows remained untreated. Clinical metritis was assessed at 7 ± 3 and 14 ± 3 d in milk (DIM) using a Metricheck device (Simcro Tech Ltd., Hamilton, New Zealand). Cows that presented a fetid, red-brownish, watery vaginal discharge were classified as having clinical metritis. Clinical endometritis was assessed through ultrasonography and defined as presence of hyperechoic fluid (>3 mm) in the uterus lumen at 50 ± 10 DIM. The incidence of retained fetal membranes was defined as the failure of expulsion of the placenta within 24 h after calving and recorded by farm personnel. The data were analyzed using the MIXED and GLIMMIX procedures of SAS (SAS Institute Inc., Cary, NC) as a randomized complete block design. A lower proportion of cows treated with acetylsalicylic acid developed clinical metritis at 7 ± 3 DIM (ASA = 34.97 ± 5.57%; UNT = 57.21 ± 5.80%) and tended to develop clinical endometritis at 50 ± 10 DIM (ASA = 3.84 ± 2.67%; UNT = 13.61 ± 5.23%) compared with cows that remained untreated. Cows treated with acetylsalicylic acid tended to require 18 d less to conceive compared with UNT cows (ASA = 125.63 ± 8.21 d; UNT = 143.44 ± 6.28 d). Furthermore, there was a tendency for a treatment × ABRT interaction, whereby ASA cows that aborted at first service tended to conceive 35 d sooner compared with UNT cows that aborted at first service (ASA = 151.42 ± 15.90 d; UNT = 186.38 ± 11.84 d). Although there was no difference in pregnancy per AI at first service between treatment groups (ASA = 23.88 ± 7.92%; UNT = 17.93 ± 6.31%), the proportion of cows aborting at first service in the ASA group tended to be lower than that in the UNT group (ASA = 1.03 ± 1.06%; UNT = 6.04 ± 2.62%). Results from this study suggest that a short-duration acetylsalicylic acid treatment after calving may decrease the incidence of uterine diseases and improve reproductive success in cows that aborted at first service in dairy cattle.

Administration of acetylsalicylic acid after parturition in lactating dairy cows under certified organic management: Part I. Milk yield, milk components, activity patterns, fertility, and health

Parturition is a natural process that gradually progresses from one stage to the next. However, around 5% of dairy cows will experience dystocia, which is considered to be a painful and stressful event. Studies have reported positive effects on cow performance and welfare after treatment with nonsteroidal anti-inflammatory drugs during the first postpartum days. The objectives were to assess the effects of acetylsalicylic acid administration after calving on (1) milk yield and components, (2) daily activity patterns, (3) reproductive performance, and (4) health in lactating dairy cows under certified organic management. Cows from 3 organic herds were enrolled. Within 12 h after parturition, cows were blocked by parity and calving ease and randomly assigned to 2 treatments: (1) aspirin (ASP; n = 278), in which cows received 4 consecutive treatments every 12 h with acetylsalicylic acid (100 mg/kg; 2 boluses) or (2) placebo (PLC, n = 285), in which cows received 4 treatments every 12 h with gelatin capsules (2 capsules) filled with water. Daily milk yield for the first 30 d in milk (DIM) and monthly milk yield, fat, protein, and somatic cell count (SCC) data from the first 5 Dairy Herd Improvement Association tests were collected. Activity patterns were measured using activity data loggers in the first 7 DIM. Clinical disease events (60 DIM) and fertility data were collected from on-farm computer records. Statistical analysis was performed using the MIXED (milk yield, components, and activity), LIFETEST (fertility), and GLIMMIX (health) procedures of SAS (SAS Institute Inc., Cary, NC). Overall, ASP cows produced 1.82 kg/d more milk than PLC cows during the first 30 DIM. Interestingly, cows that experienced dystocia and received ASP produced 4.48 kg/d more milk compared with cows in the PLC group that experienced dystocia. Cows treated with ASP had lower somatic cell count during the first 5 Dairy Herd Improvement Association tests. There were no differences in daily lying time, lying bouts, and lying bout duration between the ASP and PLC groups. However, cows in the ASP group had 587,64 steps/d more compared with PLC cows. In addition, ASP cows tended to require fewer days (ASP = 113.76 ± 4.99 d; PLC = 125.36 ± 4.74 d) and needed fewer services (ASP = 1.86 ± 0.21 services; PLC = 2.19 ± 0.24 services) to become pregnant compared with PLC cows. There were no differences in clinical disease events between treatments. Results from this study suggest that treating cows with ASP after calving may help improve milk yields and udder health, increase activity, and enhance fertility in dairy cattle under certified organic management.

Administration of acetylsalicylic acid after parturition in lactating dairy cows under certified organic management: Part II. Biomarkers of nociception, inflammation, and stress

The objective was to assess the effect of oral administration of acetylsalicylic acid after calving on the concentrations of substance P (SP), haptoglobin (HP), and cortisol in lactating dairy cows. Holstein dairy cows (n = 152) from 3 organic herds were included. At parturition, cows were blocked by parity [multiparous (MULT) and primiparous (PRIM)] and calving ease [eutocia (EUT) and dystocia (DYS)] and were randomly assigned to 1 of 2 treatment groups: aspirin (ASP; n = 76), in which within 12 h after parturition cows received 4 treatments with acetylsalicylic acid (100 mg/kg; 2 boluses) at 12-h intervals, or placebo (PLC; n = 76), in which within 12 h after parturition cows received 4 consecutive treatments with gelatin capsules (2 capsules) containing water 12 h apart. Blood samples were collected immediately before treatment and at 12, 24, 36, 48, and 168 h (7 DIM) for assessment of circulating concentration of SP, HP, and cortisol. Based on farm records, cows were classified in the following clinical disease categories: no clinical disease event (NO-EVT), a single clinical disease event (SI-EVT), and more than 1 clinical disease event (MU-EVT). The study data were analyzed as a randomized complete block design using mixed multiple linear and logistic regression models. With regard to HP, there was a tendency for an interaction between treatment and parity, where MULT cows treated with ASP had lower concentration of HP compared with MULT cows treated with PLC (ASP = 124.33 ± 6.83 µg/mL; PLC = 143.9 ± 7.24 µg/mL). Analysis by calving ease showed that cows with DYS had higher concentrations of HP (DYS = 159.17 ± 5.97 µg/mL; EUT = 138.72 ± 6.22 µg/mL) and SP (only at 168 h; DYS = 64.99 pg/mL, 95% confidence interval, CI: 2.68-2.81; EUT = 60.33 pg/mL, 95% CI: 2.91-3.06) after calving compared with EUT cows. Regardless of treatment, PRIM cows had higher concentrations of SP (MULT = 55.11 pg/mL, 95% CI: 1.27-1.30; PRIM = 57.62 pg/mL, 95% CI: 1.99-2.06), HP (MULT = 134.14 ± 4.96 µg/mL; PRIM = 163.75 ± 7.76 µg/mL), and cortisol (MULT = 18.65 µg/mL, 95% CI: 1.02-1.05; PRIM = 21.92 µg/mL, 95% CI: 1.67-1.74) compared with MULT cows. In addition, cows that experienced SI-EVT or MU-EVT had higher concentrations of HP (NO-EVT = 134.13 ± 5.95 µg/mL; SI-EVT = 142.68 ± 7.32 µg/mL; MU-EVT = 170.03 ± 9.42 µg/mL) and cortisol (NO-EVT = 17.86 µg/mL, 95% CI: 1.20-1.24; SI-EVT = 21.01 µg/mL, 95% CI: 1.61-1.67; MU-EVT = 22.01 µg/mL, 95% CI: 2.08-2.18) compared with cows with NO-EVT recorded. Results from this study suggest that a short-duration anti-inflammatory therapy after calving reduced HP in MULT cows but may not have effects on SP and cortisol concentrations. Calving ease and parity affected the concentrations of markers of inflammation, nociception, and stress regardless of treatment. Further research is warranted to assess anti-inflammatory strategies aimed at decreasing inflammation and stress in DYS and PRIM cows and therefore improve welfare and performance of these high-priority groups.

Effects of postpartum acetylsalicylic acid on metabolic status, health, and production in lactating dairy cattle

The transition period is one of the most challenging times for dairy cattle. Previous research suggests that treatment of postpartum cows with anti-inflammatory drugs may decrease pain and inflammation, enhancing cow welfare and performance during this challenging period. However, these strategies involve numerous time-consuming interventions, which require extra labor and do not fit modern farm logistics. The objective of this experiment was to assess the effects of acetylsalicylic acid (ASA) every 24 h for 2 d after calving on (1) daily milk yield, daily milk conductivity, and daily rumination during the first 60 days in milk (DIM), and 305-d mature-equivalent milk, milk fat, and milk protein yields, (2) body condition score, β-hydroxybutyrate (BHB), and haptoglobin, and (3) incidence of clinical diseases during the first 60 DIM. Dairy cows (n = 246) from a dairy farm located in Pennsylvania were enrolled in this experiment. Cows were blocked by parity and assigned randomly to 1 of 2 treatments: (1) ASA (n = 121), in which cows received 2 treatments with ASA (200 mg/kg; 4 boluses), the first within 12 h after parturition and the second 24 h later; or (2) untreated (UNT; n = 125), in which cows remained untreated. Blood samples were collected at 30 ± 6 h, 7 ± 3 d, and 14 ± 3 d after calving to measure BHB and haptoglobin concentrations. Body condition score was assessed at enrollment, 7 ± 3 DIM, 14 ± 3 DIM, and 50 ± 10 DIM. Furthermore, incidences of diseases, daily rumination, daily milk yield, and daily milk conductivity during the first 60 DIM and 305-d mature-equivalent milk, milk fat, and milk protein yields were collected from on-farm computer records. The data were analyzed using mixed multiple linear and logistic regression models as a randomized complete block design. Multiparous cows treated with ASA produced 1.64 kg/d more milk compared with multiparous cows that remained untreated (ASA = 41.66 ± 0.88 kg/d; UNT = 40.02 ± 0.81 kg/d) during the first 60 DIM. There was no difference in daily milk conductivity and rumination between treatments. Cows treated with ASA had lower concentration of BHB (ASA = 1.16 ± 0.64 mmol/L; UNT = 1.23 ± 0.80 mmol/L) during the first 14 ± 3 DIM and had higher body condition score within the first 50 ± 10 DIM compared with cows that remained UNT. There were no differences in circulating concentrations of haptoglobin between treatments. These results support previous findings showing that the use of anti-inflammatory drugs after calving may increase milk production and affect the metabolic status of dairy cows.

Short communication: Assessment of biomarkers of inflammation in the vaginal discharge of postpartum dairy cows diagnosed with clinical metritis

Clinical metritis, characterized by the presence of an enlarged uterus and abnormal red-brownish foul-smelling vaginal discharge (VD), is a prevalent condition that causes important economic losses to dairy operations. The accurate diagnosis and treatment of this disease can help decrease its negative effects on the well-being and performance of dairy cows. The objectives of this study were to assess (1) the concentration of haptoglobin (Hp) and neutrophil-derived haptoglobin-matrix metalloproteinase 9 (Hp-MMP 9) in the VD of postpartum cows; and (2) the correlation between Hp and Hp-MMP 9 concentrations in serum and VD. Fifty-three dairy cows from 4 farms in central Pennsylvania were enrolled in this observational study.. Postpartum cows (7 ± 3 DIM) were screened using a Metricheck device to assess VD score (VDS): 1, clear fluid (n = 4); 2, < 50% white purulent fluid (n = 14); 3, > 50% white purulent fluid (n = 8); 4, red-brownish watery fluid without fetid smell (n = 22); and 5, fetid red-brownish watery fluid (n = 5). Blood and VD samples were collected for assessment of Hp and Hp-MMP 9 concentrations. Cows with a VDS of 4 or 5 (VDS4/5) had higher serum Hp concentrations than cows with a VDS of 1, 2, or 3 (VDS1/3; 93 ± 187 µg/mL vs. 59 ± 106 µg/mL, respectively). Similarly, cows with VDS4/5 had higher VD Hp concentrations than cows with VDS1/3 (73 ± 56 µg/mL vs. 17 ± 16 µg/mL, respectively). We found a significant correlation (0.37) between Hp levels in serum and in VD. We found no difference in serum Hp-MMP 9 between VDS4/5 and VDS1/3 cows. The VD concentrations of Hp-MMP 9 were higher in VDS4/5 cows than in VDS1/3 cows (7,629 ± 9,847 ng/mL vs. 1,567 ± 2,165 ng/mL, respectively). The correlation between Hp-MMP 9 in serum and VD was 0.22; nevertheless, it was not statistically significant. Interestingly, Hp and Hp-MMP 9 concentrations were higher in VD samples than in serum, regardless of VDS. Results from this study suggest that inflammatory biomarkers may be increased in cows with a VDS of 4 or 5. Further research should be aimed at elucidating the processes involved in inflammatory biomarker production and transportation in the uterus, as well as the effect of these biomarkers on endometrial cells.

Associations of pre- and postpartum lying time with metabolic, inflammation, and health status of lactating dairy cows

The objective was to evaluate the associations of pre- and postpartum lying time (LT) with serum total calcium (Ca), nonesterified fatty acids (NEFA), β-hydroxybutyrate (BHB), and haptoglobin concentrations, hemogram, and health status of dairy cows. A total of 1,052 Holstein cattle (401 nulliparous heifers and 651 parous cows) from 3 commercial dairy farms were fitted with electronic data loggers (IceQube, IceRobotics, Edinburgh, UK) on a hind leg 14 ± 3 d before parturition (dpp) and removed at 14 ± 3 d in milk (DIM) to assess their LT. Lying time data were summarized and reported daily (min/d or h/d). Serum concentrations of NEFA (at 14 ± 3 and 7 ± 3 dpp), total serum calcium within 48 h after calving, and BHB (at 7 ± 3 and 14 ± 3 DIM) were determined. Serum concentration of haptoglobin was determined and a hemogram was performed on a subsample of 577 cows (237 primiparous and 340 multiparous) at 7 ± 3 DIM. Cases of milk fever, retained placenta, metritis, mastitis, pneumonia, and digestive disorders within 30 DIM were recorded and cows were categorized into 1 of 4 groups: (1) nondiseased (ND, n = 613; cows without ketosis and any other health conditions); (2) cows with only ketosis (KET, n = 152); (3) sick cows experiencing ≥1 health conditions, but without ketosis (SICK, n = 198); or (4) cows with ketosis plus at least one other health condition (KET+, n = 61). Data were analyzed using mixed linear regression models or logistic regression (MIXED or GLIMMIX procedures). Lying time within 14 dpp had a significant positive quadratic association with serum NEFA concentrations at 14 ± 3 and 7 ± 3 dpp but was not significantly associated with serum Ca concentration within 48 h after calving. Lying time during the first 14 DIM after parturition had a significant linear association with the risk of ketosis within 14 DIM. For every 1-h increment in mean LT (from 8 to 15 h/d) within the first 14 DIM after calving, the risk of diagnosis with ketosis within 14 DIM increased by 3.7 percentage points. Regardless of parity, a greater proportion of KET and KET+ groups had increased serum prepartum NEFA concentration (≥400 µEq/L) and increased body condition loss from 14 dpp to 28 DIM compared with SICK and ND cows. A greater proportion of multiparous KET and KET+ cows had hypocalcemia within 48 h after calving compared with ND and SICK cows, but we did not detect a significant association between hypocalcemia and health status on primiparous cows. Multiparous KET+ cows had significantly reduced neutrophils and white blood cell count compared with ND cows, but lymphocytes did not differ. Regardless of parity, KET+ and SICK cows had significantly higher concentrations of serum haptoglobin compared with ND cows. These results suggest that LT along with energy and Ca balance are critical for transition cow health.

Effect of serum calcium status at calving on survival, health, and performance of postpartum Holstein cows and calves under certified organic management

The study objective was to assess the effect of hypocalcemia (HYPO; ≤2.0 mmol/L) of the dam at calving on survival, health, and performance of lactating dairy cows and their calves under certified organic management. Prepartum dairy cows (primiparous, n = 445; multiparous, n = 328) from 1 dairy herd were monitored (prepartum pen) for imminent signs of parturition (appearance of amniotic sac outside the vulva) until birth. All calves were subject to the same newborn care, colostrum management, and failure of passive transfer assessment (serum total protein ≤5.5 mg/dL). Serum total calcium of cows was determined in samples taken within 2 h after calving. To define HYPO cows after calving, a cut-point of total serum Ca concentration with optimal sensitivity and specificity to predict metritis or calf diarrhea was established by using the receiver operator characteristic. The effect of HYPO on survival (died or culled within 60 DIM), health status, and pregnancy per artificial insemination (PAI) for first services of lactating cows were analyzed using the GLIMMIX procedure of SAS. Additionally, the effect of HYPO at calving on days in milk (DIM) at first service (DIMFS), milk yield (kg), milk components (percent fat and protein), and somatic cell count were analyzed for the first 3 Dairy Herd Improvement Association (DHIA) tests using the MIXED procedure of SAS (SAS Institute Inc., Cary, NC). The effect of parity (primiparous and multiparous), body condition score at calving, and manure hygiene score at calving were also included in the statistical models. The effect of HYPO at calving on calf survival, serum total protein, and diarrhea within 10 d of age were assessed using GLIMMIX procedure of SAS. The overall prevalence of HYPO was 14.6% (2.7% for primiparous and 30.8% for multiparous cows). Cows experiencing HYPO at calving had greater proportion of metritis (25.1 vs. 14.7%) and culling within 60 DIM (15.9 vs. 6.8%) compared with non-HYPO cows, respectively. For the first 3 DHIA tests, milk yield and components did not differ between HYPO and non-HYPO cows. The DIMFS as well as proportion of cows with dystocia, births of twins, mastitis, and PAI at first service were not different between HYPO and non-HYPO cows. The proportion of stillbirth, weaned calves, and serum total protein did not differ between calves born from HYPO or non-HYPO cows. However, calves born from HYPO cows had greater incidence of diarrhea (49%) than calves born (33.3%) from non-HYPO cows. Findings from the present study showed that HYPO at calving had significant health implications for both dams and calves under certified organic management.

Risk factors for mortality caused by hypothalamic obesity in children with hypothalamic tumours

BACKGROUND

Hypothalamic obesity (HyOb) is a common complication of childhood hypothalamic tumours. Patients with HyOb probably have a higher mortality rate than those with other types of obesity due in many cases to obstructive sleep apnoea/hypoventilation.

OBJECTIVES

To identify predictive factors for mortality caused by HyOb in children.

METHODS

Twenty children with HyOb secondary to hypothalamic tumours that were followed-up for ≥3 years and aged <15 years at diagnosis, and received supraphysiological glucocorticoid treatment for ≤1 month.

RESULTS

Mean age at diagnosis was 6.36 ± 3.60 years. Mean body mass index (BMI) Standard deviation of the samples (SDS) increased from 0.77 ± 1.26 to 2.66 ± 1.45 during the first 6 months, but slowed from month 6-12 (2.73 ± 1.35). ΔBMI SDS at 0-6 months was significantly higher in patients aged <6 years at diagnosis than in those aged >6 years at diagnosis (3.71 ± 1.96 vs. 0.83 ± 0.73, P < 0.001). Maximum BMI SDS was also significantly higher in the younger group (3.88 ± 1.39 vs. 2.79 ± 0.64, P < 0.05). In all, four patients died and the mortality rate was significantly higher in the patients with a further increase in BMI SDS > 1 SDS after 6 months of therapy (RR: 8.4, P < 0.05). Both overall mortality and obesity-related mortality rates were higher in the patients aged <6 years at diagnosis (4.5-fold, 7.2-fold higher, respectively, P > 0.05). The mortality rate was also 3.7-fold higher in the patients with a maximum BMI SDS ≥ 3 at any time during the first 3 years after therapy(P > 0.05).

CONCLUSIONS

An increase in BMI SDS after 6 months of therapy was observed to be a risk factor for mortality caused by HyOb. In addition, age <6 years at diagnosis and a maximum BMI SDS ≥ 3 were associated with a higher mortality rate, indicating that earlier and more aggressive treatment of obesity is required.

Effect of intrauterine administration of gonadotropin releasing hormone with glycerol on serum LH concentrations in lactating dairy cows

The objectives of the study were to assess: (1) preovulatory serum LH concentrations and (2) synchrony of ovulation after im or iu administration of GnRH with or without the addition of glycerol. Cows were presynchronized with 2 injections of PGF2α given 14d apart (starting at 26±3DIM) followed by Ovsynch (OV; GnRH-7d-PGF2α-48h-GnRH) 12d later. At the time of the second GnRH of OV (GnRH2), cows were blocked by parity and randomly allocated to 1 of 4 treatments: (1) control (CON; n=8) received 2mL of sterile water im; (2) im (IM; n=8) received 100μg of GnRH im; (3) cows were infused with 200μg GnRH into the uterus (IU; n=9); and (4) iu administration of 200μg GnRH plus glycerol 7% v/v (IUG; n=8). Serum circulating progesterone concentrations at hour 0 did not differ (P>0.05) among groups. Concentrations of LH were greater (P<0.05) in IM than IU, IUG, and CON cows at hours 1, 1.5, 2, and 3. All cows ovulated within 48h in the IM (8/8) group followed by IU (6/9) and IUG (4/8) groups, and only two out of eight cows ovulated in the CON group. Although iu administration of GnRH in the IU and IUG groups resulted in lower serum concentrations of LH than IM cows, IU or IUG cows were able to ovulate within 48h after GnRH2 administration.

Effect of intrauterine dextrose or antibiotic therapy on reproductive performance of lactating dairy cows diagnosed with clinical endometritis

The objectives of this study were to assess the responses to treatments (clinical cure and cow survival 14 d posttherapy) of cows with clinical endometritis (CE) that received intrauterine infusion of a hypertonic solution of 50% dextrose (DEX) or subcutaneous ceftiofur crystalline free acid (CCFA) and subsequent pregnancy per artificial insemination (P/AI) in cows with CE compared with cows without CE. Cows (n=760) from 2 dairy herds were screened for CE using vaginoscopy and measurement of cervix diameters [exam 1; 26±3 d in milk (DIM)]. Cows with vaginal discharge scores of 2 or 3 (scale 0-3) were stratified by parity and randomly allocated into 1 of 3 treatment groups: (1) intrauterine infusion (∼200 mL) of 50% DEX solution (n=79); (2) 6.6 mg/kg single-dose of subcutaneous administration of CCFA (n=75); or (3) untreated control animals (CON, n=83). Fourteen days posttherapy (at 40±3 DIM), cows with CE were re-examined (exam 2; 40±3 DIM) to assess the response to treatments. All cows were presynchronized with 2 injections of PGF(2α) given 14 d apart (starting at 26±3 DIM) followed by Ovsynch (OV; GnRH-7 d-PGF-56 h-GnRH 16 h-timed-AI) 12 to 14 d later. Cows displaying signs of standing estrus any time during the protocol were inseminated, whereas the remaining cows were subjected to timed AI 16 h after the second GnRH of OV. Pregnancy diagnosis was performed via transrectal ultrasonography at 39±3d post-AI followed by pregnancy reconfirmation 30 d after the first pregnancy diagnosis. Uterine swabs revealed that Arcanobacterium pyogenes and Escherichia coli were the most predominant bacteria isolated at the time of treatments. Mortality within 14 d posttherapy was not different among treatment groups. Cows with CE had greater cervical diameter at exam 1 and decreased P/AI compared with cows without CE. Treatment with CCFA or DEX increased the proportion of cows with clear vaginal discharge (score 0; clinical cure) 14 d posttherapy compared with CON cows. Pregnancy per AI from DEX (29.8±4%) cows tended to differ from that of CON (21.1±4%) or CCFA cows (19.7±4%), but it resulted in similar P/AI as those cows without CE (39.1±2%). The use of intrauterine DEX alone or as an adjunct of antibiotic therapy for the treatment of CE needs further investigation.

Increased fertility in lactating dairy cows resynchronized with Double-Ovsynch compared with Ovsynch initiated 32 d after timed artificial insemination

The objective was to determine if using a Double-Ovsynch protocol [DO; Pre-Resynch: GnRH-7 d-PGF(2α)-3 d-GnRH, 7 d later Breeding-Resynch: GnRH-7 d-PGF(2α)-56 h-GnRH-16 h-timed artificial insemination (TAI)] to resynchronize ovulation after a previous TAI would increase synchrony and pregnancies per AI (P/AI) compared with an Ovsynch protocol initiated 32 d after TAI (D32; GnRH-7 d-PGF(2α)-56 h-GnRH-16 h-TAI). Lactating Holstein cows at various days in milk and prior AI services were blocked by parity and randomly assigned to resynchronization treatments. All DO cows received the first GnRH injection of Pre-Resynch 22 d after TAI, and cows (n=981) diagnosed not pregnant using transrectal ultrasonography 29 d after TAI continued the protocol. Pregnancy status for all D32 cows was evaluated 29 d after TAI so fertility and pregnancy loss could be compared with that of DO cows. All D32 cows received the first GnRH injection of Ovsynch 32 d after TAI, and cows (n=956) diagnosed not pregnant using transrectal palpation 39 d after TAI continued the protocol. In a subgroup of cows from each treatment, ultrasonography (n=751) and serum progesterone (P4) concentrations (n=743) were used to determine the presence of a functional corpus luteum (CL) and ovulation to the first GnRH injection of D32 and Breeding-Resynch of DO (GnRH1), luteal regression after PGF before TAI, and ovulation to the GnRH injection before TAI (GnRH2). Overall, P/AI 29 d after TAI was not affected by parity and was greater for DO compared with D32 cows (39 vs. 30%). Pregnancy loss from 29 to 74 d after TAI was not affected by parity or treatment. The percentage of cows with a functional CL (P4 ≥1.0 ng/mL) at GnRH1 was greater for DO than D32 cows (81 vs. 58%), with most DO cows having medium P4 (60%; 1.0 to 3.49 ng/ml), whereas most D32 cows had either low (42%; <1.0 ng/mL) or high (36%; ≥3.5 ng/mL) P4 at GnRH1. Ovulation to GnRH1 was similar between treatments but was affected by serum P4 at GnRH. Cows with low P4 (<1.0 ng/mL) had the greatest ovulatory response (59%), followed by cows with medium (≥1.0 to 3.49 ng/mL; 38%) and then high (≥3.50 ng/mL; 16%) P4 at GnRH1. A greater percentage of DO cows were synchronized compared with D32 cows (72 vs. 51%) primarily due to a greater percentage of D32 than DO cows without a functional CL at the PGF injection before TAI (35 vs. 17%) or without complete CL regression before GnRH2 (17 vs. 7%). We conclude that DO increased fertility of lactating dairy cows during a resynchronization program primarily by increasing synchronization of cows during the Ovsynch protocol before TAI.

10 EFFECT OF USING PROTECTIVE AI COVER SHEATHS ON FERTILITY OF LACTATING DAIRY COWS

An adequate and clean artificial insemination (AI) technique is recommended to maximize reproductive outcomes in dairy cattle. The objective of this study was to evaluate the effectiveness of using protective sheaths (PS; Continental Plastic Inc., Delavan, WI, USA) to minimize contamination of the AI catheter (AIC) on pregnancies per AI (P/AI) in lactating dairy cattle. A previous study reported no improvement on cattle fertility when using PS during first service AI (King et al. 1984 Can. Vet. J. 25, 327). Lactating cows housed in free-stall barns on a commercial dairy farm with a rolling herd milk production average of 10.140 kg were presynchronized with 2 injections of PGF2α (25 mg; Lutalyse, Pharmacia & Upjohn, Kalamazoo, MI, USA) given 14 days apart (starting at 26 ± 3 d postpartum) followed by Ovsynch [OV; GnRH-7 d-PGF2α-56 h-GnRH-16 h-timed-AI(TAI)] 12 days later. Cows presenting signs of standing heat any time during the protocol received AI, whereas the remaining animals were subjected to TAI16 h after second OV GnRH (100 μg; Cystorelin, Merial, Duluth, GA, USA). At the moment of AI (one AI technician), 996 services from lactating dairy cows were randomly assigned to 1 of the 2 groups; with (TRT, n = 487) or without (CON, n = 509) the use of PS. In the TRT group, the AIC protected with a PS was introduced into the vagina; once in the cranial portion of the vagina adjacent to the cervical os, the PS was pulled back and only the AIC was manipulated through the cervix into the uterine body for semen deposition. In the CON group, cows received AI without the PS. Additionally, sterile cotton swab (BD, Franklin Lakes, NJ, USA) samples were taken from AIC (n = 51) after AI from both treatment groups. Pregnancy diagnosis was determined by ultrasonography 42 ± 3 d after AI. Data analyses were performed using GLIMMIX (P/AI) and FREQ (culture) procedures of SAS (SAS Institute Inc., Cary, NC, USA). Cultured swab samples revealed that the use of PS was effective in minimizing contamination of the AIC (bacterial growth on AIC; TRT = 57.7% v. CON = 100%; P < 0.0002). Overall, the proportion of cows pregnant (all services) was greater (P = 0.03) for cows in TRT (42.7 ± 2.2%) compared with CON group (36.1 ± 2.1%). For first services postpartum, P/AI did not differ (P = 0.87) between CON (43.01 ± 4.4%) and TRT (43.8 ± 4.6%) groups. However, P/AI for second or greater services (≥2S) were greater (P = 0.007) in TRT (43.8 ± 2.9%) than in CON cows (32.3 ± 2.6%). Results from this study suggested that the use of PS during AI improved P/AI for ≥2S in lactating dairy cows. Performing a clean AI technique through the use of PS may be a cost-effective strategy to improve reproductive outcomes in dairy cattle. Further investigation is needed under various reproductive management conditions to confirm and determine the underlying mechanisms for these findings. Authors thank Coba/Select Sires Inc. (Columbus, OH, USA) for the donation of the AI protector sheaths, Meerland Dairy for providing the animals and Brian Alkire (Coba’s AI technician).

Reactive and undifferentiated arthritis in North Africa: use of PCR for detection of Chlamydia trachomatis

Little is known about the possible role of Chlamydia in patients with reactive or unclassified arthritis in North Africa. This study used polymerase chain reaction (PCR) to survey this population. In addition, we compared the results in three different laboratories for PCR analyses for Chlamydia trachomatis (Ct) in synovial fluid (SF) and tissue (ST) from these North African patients with reactive arthritis (ReA), undifferentiated arthritis (UA), and in rheumatoid arthritis (RA) and osteoarthritis (OA). Eight ReA (six posturethritic, two postenteritic), 23 UA, 13 OA, and 12 RA patients were studied in Algeria, Morocco, and Tunisia. Serum, SF, and ST were obtained from each patient. Ct-PCR was performed in the three different laboratories and compared to Ct-serology [microimmunofluorescence (MIF) and anti-hsp60 enzyme-linked immunosorbent assay (ELISA)] performed in one laboratory. The rate of Ct-PCR positivity in SF/ST was low: none out of the eight ReA and three out of 23 UA patients. In the controls, Ct DNA was detected in two OA SF and in one RA SF. There was no concordance for Ct-PCR positivity between the three laboratories. MIF suggested previous Ct infection (IgG-positive) in two out of five posturethritic ReA, none out of one postenteritic ReA, one out of 17 UA, and nine out of 21 RA/OA patients tested. No MIF-positive patient was PCR-positive from SF or ST. However, anti-hsp60 IgG was detected in all four out of four patients positive by PCR and in 11 out of 44 PCR-negative patients (p = 0.002). In this multinational comparative study, the rate of Ct-PCR-positive synovial specimens in North African ReA/UA patients was low. Concordance among the three PCR testing laboratories was poor indicating the need for test standardization. All Ct-PCR-positive patients were found positive by anti-hsp60 IgG serology.

Diurnal variations in the plasma concentration of parathyroid hormone in dogs

The plasma concentrations of parathyroid hormone (PTH), ionised calcium (Ca(2+)), total calcium, albumin and inorganic phosphorus, and the pH were measured in blood samples obtained from nine dogs during a period of 26 hours. The plasma pth levels fluctuated slightly during the day, by about 20 pg/ml, but there was a distinct peak (42.8 [8.8] pg/ml) at 07.00. Plasma Ca(2+) showed a diurnal pattern in which two peaks (increases of 0.03 mmol/l) were observed at 05.00 and 17.00, and the plasma concentration of inorganic phosphorus showed a similar pattern. There were no diurnal changes in total calcium or albumin.

[Usefulness of anti-citrullinated protein antibodies in the diagnosis and prognosis of rheumatoid arthritis]

Rheumatoid factors were the first biological markers used in diagnosis of rheumatoid arthritis. Their detection is rather sensitive but lack specificity. In contrast, anti-citrullinated protein antibody detection has recently been shown to have a reasonable sensitivity and a high diagnostic specificity. These autoantibodies can be present early in the disease and predict erosive arthritis. Even if an improvement of sensitivity is desirable, the anti-citrullinated protein antibody detection meets many of the requirements of a useful serological marker for rheumatoid arthritis. Its prognostic potential may provide an indication for aggressive treatment. Consequently, incorporation of anti-citrullinated protein antibody positivity as an extra criteria would improve the accuracy of the American College of Rheumatology criteria, commonly used for disease classification.

The influence of the progression of secondary hyperparathyroidism on the set point of the parathyroid hormone-calcium curve

The influence of secondary hyperparathyroidism (2 HPT) on the set point of the parathyroid hormone (PTH)-Ca(2+) curve is controversial. In vitro experiments have shown an increase in the set point. However, clinical studies with hemodialysis patients have provided a variety of results (increases, decreases and no changes in the set point have been reported). The present study was designed to investigate the influence of the progression of 2 HPT on the set point of the PTH-Ca(2+) curve. The PTH-Ca(2+) curve and the expression of parathyroid calcium receptor (CaR mRNA) and vitamin D receptor (VDR mRNA) have been studied in normal rabbits (group I, n=9) and in nephrectomized rabbits (group II, n=18) at two stages after inducing 2 HPT: 2-3 weeks (group IIA) and 5-6 weeks (group IIB). In group I, the set point of the PTH-Ca(2+) curve was 1.63+/-0.03 mM. A progressive hypocalcemia was detected during the evolution of 2 HPT (groups IIA and IIB). Rabbits from group IIA had a significant (P<0.001) decrease in the set point to values of 1.45+/-0.02 mM. However, the set point increased significantly in group IIB (P<0.001) to 1.56+/-0.03 mM. CaR mRNA was similarly decreased in groups IIA (39+/-12%) and IIB (48+/-7%). No changes were detected in VDR mRNA. In conclusion, a reduction in the set point of the PTH-Ca(2+) curve in response to decreased extracellular Ca(2+) was detected in the early phases of 2 HPT. However, with the progression of 2 HPT the set point tended to increase even though extracellular Ca(2+) was markedly decreased. The increase in the set point in the course of 2 HPT seems to be a complex process that cannot be fully explained by changes in parathyroid CaR mRNA or VDR mRNA.

Parathyroid gland function in the uremic rabbit

Rabbits with renal failure have been reported to be hypercalcemic and to have decreased parathyroid hormone (PTH) concentrations. Thus, it would seem that uremic rabbits are resistant to secondary hyperparathyroidism (HPT). The work reported here was designed to investigate parathyroid gland function in uremic rabbits and the effect of diets with different calcium (Ca) and phosphorus (P) content. The relationship between PTH and ionized calcium (Ca2+), parathyroid gland size and parathyroid cell cycle were studied in three groups of rabbits: Group I, rabbits with normal renal function on a standard diet (Ca = 1.2%, P = 0.6%); Group II, partially nephrectomized rabbits on a standard diet; and Group III, partially nephrectomized rabbits on a low Ca (0.6%)-high P (1.2%) diet. Group I rabbits had baseline Ca2+ = 1.71 +/- 0.05 mmol/l and PTH = 26.9 +/- 3.2 pg/ml. During hypo- and hypercalcemic stimulation PTH reached maximal values (PTHmax) of 94.4 +/- 5.5 pg/ml and minimal concentrations (PTHmin) of 3.2 +/- 0.2 pg/ml. Rabbits from Group II were hypercalcemic (baseline Ca2+ = 2.03 +/- 0.06 mmol/l) and had very low PTH levels (1.7 +/- 0.5 pg/ml); however, they reached a PTHmax that was similar to Group I, 92 +/- 8.7 pg/ml. Group III rabbits were hypocalcemic (baseline Ca2+ = 1.22 +/- 0.08 mmol/l) and had very high basal PTH levels (739 +/- 155 pg/ml). Their PTHmax and PTHmin were 801 +/- 169.4 pg/ml and 102.2 +/- 22.2 pg/ml, respectively. Both parathyroid gland size and parathyroid cell proliferation were increased in Group III. In conclusion, our results show that the Ca and P content of the diet markedly influence PTH secretion in the uremic rabbit and that when placed on a low Ca-high P diet uremic rabbits develop secondary HPT.