Functional and structural neuroplastic changes related to sensitization proxies in patients with Osteoarthritis: a systematic review

OBJECTIVE

Several reports in literature have identified sensitization as a possible basis for the enhanced pain reactions associated with Osteoarthritis (OA). The aim of this current systematic review is to summarize functional and structural brain changes associated with surrogate sensitization parameters assessed in patients with OA-related pain.

DESIGN

Systematic review.

SUBJECTS

Patients with OA related pain.

METHODS

A literature search was conducted systematically in MEDLINE, CINAHL, EMBASE databases for human studies up to December 2019. Articles were included if they assessed brain imaging and senzitisation parameters (quantitative sensory testing and questionnaires) in adults with OA related pain. Methodological quality was assessed using the Methodological Index for Non-Randomized Studies (MINORS) score.

RESULTS

Five studies reporting on 138 patients were included in this review. The MINORS scale yielded mean scores of 8.5/16 and 12.3/24, for the cohort and case-control studies respectively. Four low-quality studies suggest a greater pain matrix activation associated with clinical measures of sensitization in patients with OA, while another study underlined the presence of structural changes (reduced gray matter volume) in the cortical areas involved in the nociceptive processing possible also related to sensitization.

CONCLUSION

This review shows conflicting evidence for structural and functional neuroplastic brain changes related to sensitization proxies in patients with OA.

Exploring the relationship between chronic pain and cortisol levels in subjects with osteoarthritis: results from a systematic review of the literature

OBJECTIVE

Several reports in the literature have identified an association between cortisol levels and the presence of chronic pain in conditions such as rheumatoid arthritis, low back pain or whiplash. In contrast, few have examined the association of cortisol and pain in people with osteoarthritis (OA). The purpose of this systematic review was to verify the association between cortisol and pain in the OA population.

DESIGN

The databases MEDLINE, CINAHL, EMBASE were searched systematically for human studies written in English up to December 2018. Two researchers screened titles and abstracts against predefined inclusion criteria; a third resolved discrepancies. Articles were included if they measured the cortisol levels in adults with pain in the OA population. Methodological quality was assessed using Methodological Index for non-randomized Studies (MINORS) score.

RESULTS

Seven studies reporting on 415 patients were included in this review. The MINORS scale yielded mean scores of 8.6 of 16 and 17.5 of 24, for the cohort and case-control studies respectively. In general, the studies were of poor quality. A discrepancy of noteworthy associations between cortisol level comparison and pain was found.

CONCLUSIONS

This study shows that there is a discrepancy in the relationship between cortisol and pain dependent on how and when cortisol is measured. Evidence from three low-quality studies suggest increased cortisol levels in patients with pain but the conclusions have a high risk of bias. It was not possible to make a quantitative analysis comparing the relationship between cortisol and pain in the OA population.

Temporal summation of second pain: variability in responses to a fixed protocol

BACKGROUND

Temporal summation of second pain (TSSP) is relevant for the study of central sensitization, and refers to increased pain evoked by repetitive stimuli at a constant intensity. While the literature reports on participants whose pain ratings increase with successive stimuli, response to a TSSP protocol can be variable. The aim of this study was to characterize the full range of responses to a TSSP protocol in pain-free adults.

METHOD

Three hundred twelve adults received a train of brief, repetitive heat stimuli at a fixed temperature and rated the intensity of second pain after each pulse. TSSP response (Δ in pain ratings) was quantified using the most common methods in the literature, and response groups were formed: TSSP (Δ > 0), no change (Δ = 0), and temporal decrease in second pain (TDSP) (Δ < 0). A cluster analysis was performed on the Δ values to empirically derive response groups.

RESULTS

Depending on how TSSP response was quantified, 61-72% of the sample demonstrated TSSP, 11-28% had no change in pain ratings and 0-20% demonstrated TDSP. The cluster analysis found that the majority (59%) of participants fell in the no change cluster, 29% clustered into the TSSP group and 12% in the TDSP cluster.

CONCLUSIONS

Using a fixed thermal paradigm, pain-free adults exhibit substantial variability in response to a TSSP protocol not well characterized by group-mean slopes. Studies are needed to determine TSSP response patterns in clinical samples, identify predictors of response and determine the clinical implications of response variability.

Reliability of upper extremity kinematics while performing different tasks in individuals with stroke

Assessments of upper extremity performance typically include qualitative rather than quantitative measures of functional ability. Kinematic analysis is an objective, discriminative measure that quantifies movement biomechanics; however, the use within the poststroke impaired upper extremity is not well established. The purpose of this study was to examine the reliability of upper extremity kinematics in 18 individuals with stroke and 9 healthy controls. Participants performed reaching and grasping tasks over 2 separate days and metrics included movement time, peak velocity, index of curvature, trunk displacement, maximum aperture, and percentage of the movement cycle where maximum aperture occurred. The results showed moderate to high intraclass correlation and low standard error of measurement values for most variables, demonstrating that kinematic analysis may be a feasible and useful tool to quantify upper extremity movement after stroke.

Cystic fibrosis transmembrane conductance regulator (CFTR) gene mutations and risk for pancreatic adenocarcinoma

BACKGROUND

Mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene are common in white persons and are associated with pancreatic disease. The purpose of this case-control study was to determine whether CFTR mutations confer a higher risk of pancreatic cancer.

METHODS

In a case-control study, the authors compared the rates of 39 common cystic fibrosis-associated CFTR mutations between 949 white patients with pancreatic adenocarcinoma and 13,340 white controls from a clinical laboratory database for prenatal testing for CFTR mutations. The main outcome measure was the CFTR mutation frequency in patients and controls.

RESULTS

Overall, 50 (5.3%) of 949 patients with pancreatic cancer carried a common CFTR mutation versus 510 (3.8%) of 13,340 controls (odds ratio [OR], 1.40; 95% confidence interval [CI], 1.04-1.89; P = .027). Among patients who were younger when their disease was diagnosed (<60 years), the carrier frequency was higher than in controls (OR, 1.82; 95% CI, 1.14-2.94; P = .011). In patient-only analyses, the presence of a mutation was associated with younger age (median 62 vs 67 years; P = .034). In subgroups, the difference was seen only among ever-smokers (60 vs 65 years, P = .028). Subsequent sequencing analysis of the CFTR gene detected 8 (16%) compound heterozygotes among the 50 patients initially detected to have 1 mutation.

CONCLUSIONS

Carrying a disease-associated mutation in CFTR is associated with a modest increase in risk for pancreatic cancer. Those affected appear to be diagnosed at a younger age, especially among smokers. Clinical evidence of antecedent pancreatitis was uncommon among both carriers and noncarriers of CFTR mutations.

Alcohol consumption, cigarette smoking, and the risk of recurrent acute and chronic pancreatitis

BACKGROUND

Recurrent acute pancreatitis (RAP) and chronic pancreatitis (CP) are associated with alcohol consumption and cigarette smoking. The etiology of RAP and CP is complex, and effects of alcohol and smoking may be limited to specific patient subsets. We examined the current prevalence of alcohol use and smoking and their association with RAP and CP in patients evaluated at US referral centers.

METHODS

The North American Pancreatitis Study 2, a multicenter consortium of 20 US centers, prospectively enrolled 540 patients with CP, 460 patients with RAP, and 695 controls from 2000 to 2006. Using self-reported monthly alcohol consumption during the maximum lifetime drinking period, we classified subjects by drinking status: abstainer, light drinker (< or =0.5 drink per day), moderate drinker (women, >0.5 to 1 drink per day; men, >0.5 to 2 drinks per day), heavy drinker (women, >1 to <5 drinks per day; men, >2 to <5 drinks per day), or very heavy drinker (> or =5 drinks per day for both sexes). Smoking was classified as never, past, or current and was quantified (packs per day and pack-years).

RESULTS

Overall, participants' mean (SD) age was 49.7 (15.4) years; 87.5% were white, and 56.5% were women. Approximately one-fourth of both controls and patients were lifetime abstainers. The prevalence of very heavy drinking among men and women was 38.4% and 11.0% for CP, 16.9% and 5.5% for RAP, and 10.0% and 3.6% for controls. Compared with abstaining and light drinking, very heavy drinking was significantly associated with CP (odds ratio, 3.10; 95% confidence interval, 1.87-5.14) after controlling for age, sex, smoking status, and body mass index. Cigarette smoking was an independent, dose-dependent risk factor for CP and RAP.

CONCLUSIONS

Very heavy alcohol consumption and smoking are independent risks for CP. A minority of patients with pancreatitis currently seen at US referral centers report very heavy drinking.

Graded unilateral cervical spinal cord injury and respiratory motor recovery

We examined the potential contribution of ventromedial (VM) tissue sparing to respiratory recovery following chronic (1 mo) unilateral C2 spinal cord injury (SCI) in rats. Preserved white matter ipsilateral to the injury was quantitatively expressed relative to contralateral white matter. The ipsilateral-to-contralateral white matter ratio was 0 after complete C2 hemisection (C2HS) and 0.23+/-0.04 with minimal VM sparing. Inspiratory (breath min(-1)) and phrenic frequency (burst min(-1)), measured by plethysmography (conscious rats) and phrenic neurograms (anesthetized rats) respectively, were both lower with minimal VM sparing (p<0.05 vs. C2HS). Tidal volume also was greater in minimal VM sparing rats during a hypercapnic challenge (p<0.05 vs. C2HS). In other C2 hemilesioned rats with more extensive VM matter sparing (ipsilateral-to-contralateral white matter ratio=0.55+/-0.05), respiratory deficits were indicated at 1 mo post-injury by reduced ventilation during hypercapnic challenge (p<0.05 vs. uninjured). Anterograde (ventral respiratory column-to-spinal cord) neuroanatomical tracing studies showed that descending respiratory projections from the brainstem are present in VM tissue. We conclude that even relatively minimal sparing of VM tissue after C2 hemilesion can alter respiratory outcomes. In addition, respiratory deficits can emerge in the adult rat after high cervical SCI even when relatively extensive VM sparing occurs.

Multicenter approach to recurrent acute and chronic pancreatitis in the United States: the North American Pancreatitis Study 2 (NAPS2)

BACKGROUND

Recurrent acute pancreatitis (RAP) and chronic pancreatitis (CP) are complex syndromes associated with numerous etiologies, clinical variables and complications. We developed the North American Pancreatitis Study 2 (NAPS2) to be sufficiently powered to understand the complex environmental, metabolic and genetic mechanisms underlying RAP and CP.

METHODS

Between August 2000 and September 2006, a consortium of 20 expert academic and private sites prospectively ascertained 1,000 human subjects with RAP or CP, plus 695 controls (spouse, family, friend or unrelated). Standardized questionnaires were completed by both the physicians and study subjects and blood was drawn for genomic DNA and biomarker studies. All data were double-entered into a database and systematically reviewed to minimize errors and include missing data.

RESULTS

A total of 1,000 subjects (460 RAP, 540 CP) and 695 controls who completed consent forms and questionnaires and donated blood samples comprised the final dataset. Data were organized according to diagnosis, supporting documentation, etiological classification, clinical signs and symptoms (including pain patterns and duration, and quality of life), past medical history, family history, environmental exposures (including alcohol and tobacco use), medication use and therapeutic interventions. Upon achieving the target enrollment, data were organized and classified to facilitate future analysis. The approaches, rationale and datasets are described, along with final demographic results.

CONCLUSION

The NAPS2 consortium has successfully completed a prospective ascertainment of 1,000 subjects with RAP and CP from the USA. These data will be useful in elucidating the environmental, metabolic and genetic conditions, and to investigate the complex interactions that underlie RAP and CP.

The cystic fibrosis transmembrane conductance regulator gene and ion channel function in patients with idiopathic pancreatitis

Cystic fibrosis transmembrane conductance regulator (CFTR) gene mutations are associated with cystic fibrosis (CF)-related monosymptomatic conditions, including idiopathic pancreatitis. We evaluated prospectively enrolled patients who had idiopathic recurrent acute pancreatitis or idiopathic chronic pancreatitis, healthy controls, CF heterozygotes, and CF patients (pancreatic insufficient or sufficient) for evidence of CFTR gene mutations and abnormalities of ion transport by sweat chloride and nasal potential difference testing. DNA samples from anonymous blood donors were controls for genotyping. At least one CFTR mutation or variant was carried in 18 of 40 patients (45%) with idiopathic chronic pancreatitis and in 6 of 16 patients (38%) with idiopathic recurrent acute pancreatitis but in only 11 of the 50 controls (22%, P=0.005). Most identified mutations were rare and would not be identified in routine genetic screening. CFTR mutations were identified on both alleles in six patient (11%). Ion transport measurements in patients with pancreatitis showed a wide range of results, from the values in patients with classically diagnosed CF to those in the obligate heterozygotes and healthy controls. In general, ion channel measurements correlated with the number and severity of CFTR mutations. Twelve of 56 patients with pancreatitis (21%) fulfilled current clinical criteria for the diagnosis of CF, but CFTR genotyping alone confirmed the diagnosis in only two of these patients. We concluded that extensive genotyping and ion channel testing are useful to confirm or exclude the diagnosis of CF in the majority of patients with idiopathic pancreatitis.

An enteral therapy containing medium-chain triglycerides and hydrolyzed peptides reduces postprandial pain associated with chronic pancreatitis

BACKGROUND/AIM

Pain in patients with chronic pancreatitis is difficult to manage. We examined if an enteral formulation containing medium-chain triglycerides (MCT) and hydrolyzed peptides would (1) minimally stimulate the exocrine pancreas by blunting cholecystokinin release and (2) decrease pain in patients with chronic pancreatitis.

METHODS

In the first part of the study, on separate days, 6 healthy controls consumed a standard enteral formulation, an enteral formulation containing MCT and hydrolyzed peptides, and a high-fat meal. Baseline and postprandial plasma cholecystokinin (CCK) concentrations were analyzed. Subsequently, 8 patients with chronic pancreatitis were enrolled and instructed to complete a visual analog pain assessment for a baseline period of 2 weeks followed by three cans per day of the enteral formulation containing MCT and hydrolyzed peptides for 10 weeks.

RESULTS

Mean CCK levels for our control subjects were 0.46 +/- 0.29 pM at baseline, 10.75 +/- 0.45 pM in response to the high-fat meal, and 7.9 +/- 1.25 pM in response to the standard enteral formulation. Of note, CCK levels were 1.43 +/- 0.72 pM in response to the enteral supplement containing MCT and hydrolyzed peptides. In patients with chronic pancreatitis, the average improvement in pain scores from baseline to the conclusion of the study was 61.8% (p = 0.01). This corresponded to a clinical improvement in 6 of the 8 patients.

CONCLUSIONS

A complete enteral supplement containing MCT and hydrolyzed peptides minimally increases plasma CCK levels. This therapy may be effective in reducing postprandial pain associated with chronic pancreatitis.

Increased prevalence of CFTR mutations and variants and decreased chloride secretion in primary sclerosing cholangitis

Primary sclerosing cholangitis (PSC) and cystic fibrosis (CF) are both slowly progressive cholestatic liver diseases characterized by fibro-obliterative inflammation of the biliary tract. We hypothesized that dysfunction of the CF gene product, cystic fibrosis transmembrane conductance regulator (CFTR), may explain why a subset of patients with inflammatory bowel disease develop PSC. We prospectively evaluated CFTR genotype and phenotype in patients with PSC ( n=19) compared with patients with inflammatory bowel disease and no liver disease ( n=18), primary biliary cirrhosis ( n=17), CF ( n=81), and healthy controls ( n=51). Genetic analysis of the CFTR gene in PSC patients compared with disease controls (primary biliary cirrhosis and inflammatory bowel disease) demonstrated a significantly increased number of mutations/variants in the PSC group (37% vs 8.6% of disease controls, P=0.02). None of the PSC patients carried two mutations/variants. Of PSC patients, 89% carried the 1540G-variant-containing genotypes (resulting in decreased functional CFTR) compared with 57% of disease controls ( P=0.03). Only one of 19 PSC patients had neither a CFTR mutation nor the 1540G variant. CFTR chloride channel function assessed by nasal potential difference testing demonstrated a reduced median isoproterenol response of 14 mV in PSC patients compared with 19 mV in disease controls ( P=0.04) and 21 mV in healthy controls ( P=0.003). These data indicate that there is an increased prevalence of CFTR abnormalities in PSC as demonstrated by molecular and functional analyses and that these abnormalities may contribute to the development of PSC in a subset of patients with inflammatory bowel disease.

Construction and characterization of a bovine BAC library with four genome-equivalent coverage

A bovine artificial chromosome (BAC) library of 105 984 clones has been constructed in the vector pBeloBAC11 and organized in 3-dimension pools and high density membranes for screening by PCR and hybridization. The average insert size, determined after analysis of 388 clones, was estimated at 120 kb corresponding to a four genome coverage. Given the fact that a male was used to construct the library, the probability of finding any given autosomal and X or Y locus is respectively 0.98 and 0.86. The library was screened for 164 microsatellite markers and an average of 3.9 superpools was positive for each PCR system. None of the 50 or so BAC clones analysed by FISH was chimeric. This BAC library increases the international genome coverage for cattle to around 28 genome equivalents and extends the coverage of the ruminant genomes available at the Inra resource center to 15 genome equivalents.

Validation of a reverse transcription nested polymerase chain reaction (RT-nPCR) to detect bovine viral diarrhea virus (BVDV) associated with in vitro-derived bovine embryos and co-cultured cells

Sensitive RT-nPCR assays can be used for the rapid detection of viruses. The objective of this research was to validate an RT-nPCR assay for detection of BVDV associated with various samples collected from an IVF system. In 12 research replicates, we maintained matured COCs as negative controls or exposed them to 1 of 4 noncytopathic strains (SD-1, NY-1, CD-87, or PA-131) of BVDV for 1 h immediately before IVF. After 4 d of IVC, we harvested groups of 5 nonfertile ova or degenerated embryos (NFD) and some associated cumulus cells and transferred developing embryos and the remaining cumulus cells into secondary IVC drops. On the seventh d of IVC, cumulus cells, groups of 5 washed NFD and groups of 5 developed, washed embryos were harvested. We also collected single developed embryos after washing, washing with trypsin, washing and cryopreservation in ethylene glycol, or washing with trypsin and cryopreservation in ethylene glycol. All washes were performed according to International Embryo Transfer Society standards. Developed embryos and NFD were sonicated prior to assay. All samples were assayed for BVDV using virus isolation and RT-nPCR. The virus isolation and RT-nPCR assays determined that all negative control samples were BVDV-free. Virus was detected in association with all exposed cumulus cells and groups of developed embryos using both virus isolation and RT-nPCR. Results from viral assays of other exposed samples indicate enhanced sensitivity of the RT-nPCR assay. The RT-nPCR assay used in this research exhibited acceptable sensitivity, specificity, predictive value and repeatability for rapid detection of BVDV associated with the various samples obtained from an IVF system.

Differential control during maximal concentric and eccentric loading revealed by characteristics of the electromyogram

Maximal eccentric loading has been associated with higher levels of spindle afferent activity but lower levels of integrated EMG as compared to maximal concentric loading. Elbow flexor EMG was recorded from 17 subjects during concentric (CONC) and eccentric (ECC) elbow flexion at 70 degrees s(-1) using a Kin-Com dynamometer. We hypothesized that peak EMG amplitude would be more sensitive to fluctuations in facilitation by the spindle primary afferents via the segmental stretch reflex pathway, and that the mean EMG would be more reflective of the ongoing level of muscle activation. A ratio of peak to mean EMG (P/M EMG ratio) was predicted to be larger during maximal eccentric loading than maximal concentric loading. The peak EMG (P<0.013) and the P/M EMG ratio (P<0.001) were significantly greater during the ECC condition than the CONC condition. In a subgroup of three subjects who underwent 3 weeks of eccentrically biased weight training, EMG, peak torque and torque variability were assessed before and after training. P/M EMG ratio decreased, while peak torque and torque variability increased following the training. Differences in the P/M EMG ratio appear to reflect differences in the way eccentric and concentric muscle actions are controlled and do not simply represent less control during the eccentric task.

Quality controls for bovine viral diarrhea virus-free IVF embryos

Introduction of bovine viral diarrhea virus (BVDV) with cumulus-oocyte-complexes (COCs) from the abattoir is a concern in the production of bovine embryos in vitro. Further, International Embryo Transfer Society (IETS) guidelines for washing and trypsin treatment of in-vivo-derived bovine embryos ensure freedom from a variety of pathogens, but these procedures appear to be less effective when applied to IVF embryos. In this study, COCs were exposed to virus prior to IVM, IVF and IVC. Then, virus isolations from cumulus cells and washed or trypsin-treated nonfertile and degenerated ova were evaluated as quality controls for IVF embryo production. The effect of BVDV on rates of cleavage and development was also examined. All media were analyzed prior to the study for anti-BVDV antibody. Two approximately equal groups of COCs from abattoir-origin ovaries were washed and incubated for 1 h in minimum essential medium (MEM) with 10% equine serum. One group was incubated in 10(7) cell culture infective doses (50% endpoint) of BVDV for 1 h, while the other was incubated without virus. Subsequently, the groups were processed separately with cumulus cells, which were present throughout IVM, IVF and IVC. Cleavage was evaluated at 4 d and development to morulae and blastocysts at 7 d of IVC. After IVC, groups of nonfertile and degenerated ova or morulae and blastocysts were washed or trypsin-treated, sonicated and assayed for virus. Cumulus cells collected at 4 and 7 d were also assayed for virus. Anti-BVDV antibody was found in serum used in IVM and IVC but not in other media. A total of 1,656 unexposed COCs was used to produce 1,284 cleaved embryos (78%), 960 embryos > or = 5 cells (58%), and 194 morulae and blastocysts (12%). A total of 1,820 virus-exposed COCs was used to produce 1,350 cleaved embryos (74%), 987 embryos > or = 5 cells (54%), and 161 morulae and blastocysts (9%). Rates of cleavage (P = 0.021), cleavage to > or = 5 cells (P = 0.026) and development to morula and blastocyst (P = 0.005) were lower in the virus-exposed group (Chi-square test for heterogeneity). No virus was isolated from any samples from the unexposed group. For the exposed group, virus was always isolated from 4- and 7-d cumulus cells, from all washed nonfertile and degenerated ova (n = 40) and morulae and blastocysts (n = 57) and from all trypsin-treated nonfertile and degenerated ova (n = 80) and morulae and blastocysts (n = 91). Thus, virus persisted in the system despite the presence of neutralizing antibody in IVM and IVC media, and both washing and trypsin treatment were ineffective for removal of the virus. Presence of virus in 4- and 7-d cumulus cells as well as in nonfertile and degenerated ova were good indicators of virus being associated with morulae and blastocysts.

Developing efficient strategies for the generation of transgenic cattle which produce biopharmaceuticals in milk

At the close of the millennium, a revolution in the treatment of disease is taking shape due to the emergence of new therapies based on human recombinant proteins. The ever-growing demand for such pharmaceutical proteins is an important driving force for the development of safe and large-scale production platforms. Since the efficacy of a human protein is generally dependent on both its amino acid composition as well as various post-translational modifications, many recombinant human proteins can only be obtained in a biologically active conformation when produced in mammalian cells. Hence, mammalian cell culture systems are often used for expression. However, this approach is generally known for limited production capacity and high costs. In contrast, the production of (human) recombinant proteins in milk of transgenic farm animals, particularly cattle, presents a safe alternative without the constraint of limited protein output. Moreover, compared to cell culture, production in milk is very cost-effective. Although transgenic farm animal technology was still in its infancy a decade ago, today it is on the verge of fulfilling its potential of providing therapeutic proteins that can not be produced otherwise in sufficient quantities or at affordable cost. Since 1989, we have been at the forefront of this development, as illustrated by the birth of Herman, the first transgenic bull. In this communication, we will present an overview of approaches we have taken over the years to generate transgenic founder animals and production herds. Our initial strategies were based on microinjection; at the time the only viable option to generate transgenic cattle. Recently, we have adopted a more powerful approach founded on the application of nuclear transfer. As we will illustrate, this strategy presents a breakthrough in the overall efficiency of generating transgenic animals, product consistency, and time of product development.

Physical assignment of the bovine MHC class IIa and class IIb genes

Screening of a bovine yeast artificial chromosome (YAC) library revealed two clones which contain most of the class II genes of the major histocompatibility complex (MHC) known to date. The YACs were mapped by fluorescence in situ hybridization (FISH) and characterized for the class II genes they contain. We found that the classic class II genes BoLA- DQA, -DQB, -DRA, and -DRB3 are located at BTA 23q21 and the non-classic class II genes DYA, DIB, LMP2, LMP7, TAP2, BoLA-DOB, -DMA, -DMB, and -DNA are located at BTA 23q12-->q13. These two different mapping locations confirm and extend previous findings of a gross physical distance between classic and non-classic MHC class II genes in cattle.

Mapping quantitative trait loci for milk production and health of dairy cattle in a large outbred pedigree

Quantitative trait loci (QTL) affecting milk production and health of dairy cattle were mapped in a very large Holstein granddaughter design. The analysis included 1794 sons of 14 sires and 206 genetic markers distributed across all 29 autosomes and flanking an estimated 2497 autosomal cM using Kosambi's mapping function. All families were analyzed jointly with least-squares (LS) and variance components (VC) methods. A total of 6 QTL exceeding approximate experiment-wise significance thresholds, 24 QTL exceeding suggestive thresholds, and 34 QTL exceeding chromosome-wise thresholds were identified. Significance thresholds were determined via data permutation (for LS analysis) and chi-square distribution (for VC analysis). The average bootstrap confidence interval for the experiment-wise significant QTL was 48 cM. Some chromosomes harbored QTL affecting several traits, and these were always in coupling phase, defined by consistency with genetic correlations among traits. Chromosome 17 likely harbors 2 QTL affecting milk yield, and some other chromosomes showed some evidence for 2 linked QTL affecting the same trait. In each of these cases, the 2 QTL were in repulsion phase in those families appearing to be heterozygous for both QTL, a finding which supports the build-up of linkage disequilibrium due to selection.

Report of the first workshop on the genetic map of bovine chromosome 1

A report of the first workshop on the genetic map of bovine chromosome 1 (BTA1) is presented. Five laboratories contributed 31,962 informative meioses from 70 loci. Thirty-two loci which had been typed by at least two laboratories were used to construct a framework genetic map with a likelihood ratio support of at least 1000:1 for locus order. The resulting sex-averaged framework map contained 26 loci and spanned 163.6 CM. The lengths of the female and male maps were 159.5 CM and 165.3 CM, respectively, and there was evidence for an expansion in the telomeric one-third of the male map. Of the four cases where order for closely linked loci differed among the maps produced for each of the contributing laboratories, a consensus order was obtained for three in the framework map. The average genetic distance between framework loci on the sex-averaged map was 6.3 CM.

Isolation of microsatellites from a bovine YAC clone harbouring the SOD1 gene

A bovine yeast artificial chromosome (YAC) clone containing the superoxide dismutase 1 (SOD1) gene was used as a template for polymerase chain reaction (PCR) amplification using a conserved short interspersed nuclear element (SINE) primer. Two highly polymorphic microsatellites with nine and eight alleles were isolated and mapped by linkage analysis to the centromeric region of BTA1. These microsatellites will be used in the construction of a genetic and physical map of the SOD1 region towards positional cloning of the polled gene.

Comparative linkage mapping of human chromosome 13 and bovine chromosome 12

A comparative linkage map of human chromosome 13 and bovine chromosome 12 was constructed using eight polymorphic microsatellite markers associated with six specific genes. Linkage of these was also examined relative to five previously mapped anonymous microsatellite markers. Seven gene-linked markers were developed from bovine large-insert genomic clones containing one of five genes of interest (serotonin receptor subtype 2, fms-related tyrosine kinase, coagulation factor 10, retinoblastoma susceptibility gene, collagen type IV alpha 1), and one additional marker was developed from a microsatellite resident within an intron of the bovine dopachrome tautomerase gene. Four of these loci were previously assigned to bovine chromosome 12 by analysis of a somatic cell hybrid panel. This study provides linkage information for examining gene order in this conserved synteny group. The comparative linkage mapping results indicate that the q arm of human chromosome 13 is almost entirely conserved in bovine chromosome 12. One intrachromosomal rearrangement was detected in this linkage group relative to human, and this rearrangement was confirmed by fluorescence in situ hybridization results.

A medium-density genetic linkage map of the bovine genome

A cattle genetic linkage map was constructed which covers more than 95 percent of the bovine genome at medium density. Seven hundred and forty six DNA polymorphisms were genotyped in cattle families which comprise 347 individuals in full sibling pedigrees. Seven hundred and three of the loci are linked to at least one other locus. All linkage groups are assigned to chromosomes, and all are orientated with regards to the centromere. There is little overall difference in the lengths of the bull and cow linkage maps although there are individual differences between maps of chromosomes. One hundred and sixty polymorphisms are in or near genes, and the resultant genome-wide comparative analyses indicate that while there is greater conservation of synteny between cattle and humans compared with mice, the conservation of gene order between cattle and humans is much less than would be expected from the conservation of synteny. This map provides a basis for high-resolution mapping of the bovine genome with physical resources such as Yeast and Bacterial Artificial Chromosomes as well as providing the underpinning for the interpolation of information from the Human Genome Project.

Development of a bovine X chromosome linkage group and painting probes to assess cattle, sheep, and goat X chromosome segment homologies

The X chromosome linkage group is conserved in placental mammals. However, X chromosome morphological differences, due to internal chromosome rearrangements, exist among mammalian species. We have developed bovine chromosome painting probes for Xp and Xq to assess segment homologies between the submetacentric bovine X chromosome and the acrocentric sheep and goat X chromosomes. These painting probes and their corresponding DNA libraries were developed by chromosome micromanipulation, DNA micropurification, microcloning, and PCR amplification. The bovine Xp painting probe identified an interstitially located homologous segment in the sheep and goat Xq region, most probably resulting from chromosome inversion. Ten type II (microsatellite) markers obtained from the bovine Xq library and five other X chromosome assigned, but unlinked, markers were used to generate a linkage map for Xq spanning 89.4 centimorgans. The chromosome painting probes and molecular markers generated in this study would be useful for comparative mapping and tracing of internal X chromosome rearrangements in all ruminant species and would contribute to the understanding of mammalian sex chromosome evolution.

Relationship of restriction fragment length polymorphisms (RFLP) at the bovine calpastatin locus to calpastatin activity and meat tenderness

Restriction fragment length polymorphisms (RFLP) have been identified at the bovine calpastatin locus. The objective of the present study was to determine whether these polymorphisms are related to variations in calpastatin activity or beef tenderness in unrelated animals of mixed breeding. A sample of 83 crossbred steers from sires representing eight different breeds was examined to determine this relationship. A 2.2-kb cDNA coding for domains 2 through 4 plus a 3' untranslated region of bovine skeletal muscle calpastatin was used as a probe for calpastatin RFLP. Polymorphisms were found using the restriction enzymes BamHI and EcoRI. Polymorphic restriction fragments for BamHI were 9.0 and 5.0 kb and for EcoRI were 6.0 and 4.0 kb. Allelic frequencies for BamHI restriction fragments were .53 for the 9.0-kb allele and .47 for the 5.0-kb allele. Allelic frequencies for EcoRI restriction fragments were .43 for the 6.0-kb allele and >57 for the 4.0-kb allele. No polymorphisms were identified using the restriction enzymes BglII, DraI, or PstI. No associations between EcoRI and BamHI RFLP and 24-h calpastatin activity of Warner-Bratzler shear force at 14 d postmortem were detected. Therefore, the polymorphic EcoRI and BamHI restriction sites within the bovine calpastatin locus do not detect DNA sequence differences responsible for variation in calpastatin activity or tenderness of aged beef. Therefore, these polymorphisms cannot be used to predict tenderness of aged beef from unrelated animals of mixed breeding. These results do not exclude the possibility that other DNA sequences in or near the bovine calpastatin gene are responsible for variation in calpastatin activity or meat tenderness. The lack of a relationship between these calpastatin RFLP and meat tenderness must be distinguished from the well-documented relationship between calpastatin activity and meat tenderness. Therefore, further development of calpastatin-based methods for predicting beef tenderness in unrelated animals of mixed breeding should focus on basic factors influencing calpastatin activity at the molecular and cellular level.

Divergent selection for blood serum insulin-like growth factor I concentration in beef cattle: I. Nongenetic effects

Data were obtained from an ongoing experiment involving divergent selection for blood serum IGF-I concentration in purebred Angus cattle. The experiment includes approximately 100 spring-calving (50 high and 50 low line) and 100 fall-calving (50 high and 50 low line) cows. The selection criterion is the mean of IGF-I concentrations measured on each animal at d 28, 42, and 56 of the postweaning performance test. Mean IGF-I values were available for a total of 526 bull and heifer calves. Pooled across years and breeding seasons, high line progeny averaged 21 +/- 6, 17 +/- 6, and 23 +/- 5 ng/mL more IGF-I (P < .01) than low line progeny at d 28, 42, and 56 of the postweaning test. Season effects on IGF-I approached statistical significance only at d 42 and 56 of the postweaning period. Pooled across years and selection lines, spring minus fall differences were 9 +/- 10 (P = .52), -17 +/- 10 (P = .10), -22 +/- 9 (P = .07), and -9 +/- 6 (P = .45) ng/mL for IGF-I concentrations at d 28, 42, and 56 of the postweaning test and for mean IGF-I, respectively. Sex effects on serum IGF-I concentration were highly significant, with greater IGF-I expression in bulls, but were confounded with diet and location. Age of dam effects were not significant. Regressions of IGF-I concentration on on-test age of calf ranged from .46 +/- .13 to 1.08 +/- .20 ng.mL-1.d-1 and were highly significant for all measures of IGF-I.(ABSTRACT TRUNCATED AT 250 WORDS)

Physical and linkage mapping of the bovine genome with cosmids

We have initiated a mapping strategy using cosmid clones to chromosomally anchor a high-resolution bovine genetic linkage map. Ten cosmids containing microsatellites were assigned to bovine chromosomes by fluorescence in situ suppression hybridization (FISH). Four cosmid clones, three of which contain an informative microsatellite, were assigned to autosomes 5, 13, 24, and 28. The assignment to autosome 13 anchors bovine syntenic group U11. Two additional cosmid clones, each containing informative microsatellites, are assigned to autosomes 9 and 29, anchoring bovine linkage groups U2 and U8, respectively. Four cosmid clones, three of which contain informative microsatellites, also provide the first assignment to autosome 25, anchoring bovine syntenic group U7 and orienting the corresponding linkage group relative to the centromere.

Combined Q-banding and fluorescence in situ hybridization for the identification of bovine chromosomes 1 to 7

Eleven probes were assigned to bovine chromosomes 1 to 7 by fluorescence in situ hybridization (FISH). The identification of chromosomes was based on QFQ-banding prior to in situ hybridization and comparison with the Reading Conference (1976) and ISCNDA (1989) standards. The probes used for FISH can now be utilized as identification and discrimination features for bovine chromosomes 1 to 7 and particularly for chromosomes 4 and 6, which are difficult to distinguish. Comparison of our mapping data with previous assignments and of the standard chromosome banding patterns prompt us to propose a change in the ISCNDA nomenclature: ISCNDA chromosome 4 should be named chromosome 6 and vice versa. Chromosome 4 is marked by the ribosomal RNA cluster RNR3, and chromosome 6 is characterized by the casein gene cluster and an anonymous satellite (D6Z1).

Relationship of air temperature, relative humidity, precipitation, photoperiod, wind speed and solar radiation with serum insulin-like growth factor I (IGF-I) concentration in Angus beef cattle

Eight paternal half-sib Angus calves born in late April and early May, 1988 were used to investigate the potential relationship of serum IGF-I concentration with photoperiod and various weather variables including minimum, maximum and average air temperatures, relative humidity, precipitation, wind speed and solar radiation. To determine IGF-I concentration, blood samples were obtained at birth and then weekly until the calves reached 1 mo of age and bi-weekly thereafter. Blood sampling continued until the calves reached puberty as determined by progesterone and testosterone assays. Photoperiod and each weather variable were averaged over the 3 d prior to and including the day of blood sampling (4-d average). Data were divided into two periods: (1) birth through the end of the postweaning period and (2) postweaning period only. Serum IGF-I concentrations were analyzed using a model which included the fixed effects of sex and sample number, the random effect of calf nested within sex and the fixed interaction of sex x sample number, in addition to covariates for weight, photoperiod and weather variables. From birth through the end of the postweaning test, none of the weather variables or photoperiod had significant effects on serum IGF-I concentrations when each was fitted separately. For the postweaning period only, cubic regression coefficients for minimum and average temperatures were .0962 +/- .0325 ng/ml/degrees C3 and .0976 +/- .0272 ng/ml/degrees C3, respectively (P < .01). The quadratic regression coefficient for relative humidity during the postweaning period was -.2991 +/- .1142 ng/ml/%2 (P < .05). The quartic regression coefficient for wind speed during the postweaning period was -36.435 +/- 13.00 ng/ml/(km/hr)4 (P < .01). Maximum temperature, precipitation, solar radiation and photoperiod did not have significant effects on postweaning serum IGF-I concentrations. Based on these data, we conclude that temperature, humidity and wind speed were contributing factors to variation in serum IGF-I concentrations in postweaned beef calves.

Linkage of bovine erythrocyte antigen loci B, C, L, S, Z, R' and T' and the serum protein loci post-transferrin 2 (PTF 2), vitamin D binding protein (GC) and albumin (ALB) to DNA microsatellite markers

Seven bovine erythrocyte antigen loci and three serum protein loci were tentatively assigned to chromosomes or synteny groups by linkage analysis to previously assigned microsatellite DNA markers. The erythrocyte antigen locus EAB was mapped to synteny group U27; EAC to chromosome 18, synteny group U9; EAL to chromosome 3, synteny group U6; EAS to chromosome 21, synteny group U4; EAZ to chromosome 10, synteny group U5; EAR' to chromosome 16, synteny group U1; and EAT' to chromosome 19, synteny group U21. The vitamin D binding protein (GC) and albumin (ALB) loci were assigned to chromosome 6, synteny group U15 and post-transferrin 2 (PTF 2) to chromosome 19, synteny group U21.

A genetic linkage map for cattle

We report the most extensive physically anchored linkage map for cattle produced to date. Three-hundred thirteen genetic markers ordered in 30 linkage groups, anchored to 24 autosomal chromosomes (n = 29), the X and Y chromosomes, four unanchored syntenic groups and two unassigned linkage groups spanning 2464 cM of the bovine genome are summarized. The map also assigns 19 type I loci to specific chromosomes and/or syntenic groups and four cosmid clones containing informative microsatellites to chromosomes 13, 25 and 29 anchoring syntenic groups U11, U7 and U8, respectively. This map provides the skeletal framework prerequisite to development of a comprehensive genetic map for cattle and analysis of economic trait loci (ETL).

A conceptual database model for genomic research

We describe a conceptual model for genome databases that facilitates the process of building, maintaining, and disseminating physically anchored genetic linkage maps. The model has been implemented as a relational database at the Roman L. Hruska U.S. Meat Animal Research Center (MARC). Development of consensus maps using disparate data from different reference pedigrees or laboratories is supported. The model is of use to quantitative and population geneticists interested in loci that affect phenotypes and marker-assisted selection, and it is sufficiently flexible for centralized, species genome databases facilitating comparative mapping. The MARC genome database is used to assemble, maintain, and disseminate physically anchored genetic linkage maps for cattle, swine, and sheep currently based on more than 100,000 genotypes from 1,000 markers. Integrated with linkage analysis software, this database permits frequent updates of physically anchored genetic linkage maps.

Divergent selection for postweaning feed conversion in Angus beef cattle: III. Linear body measurements of progeny

Postweaning performance data were obtained on 401 group-fed, purebred Angus calves from 24 selected sires (12 high- and 12 low-feed-conversion sires) from 1983 through 1986 at the Northwestern Branch of the Ohio Agricultural Research and Development Center. Body measurements of progeny were taken from 1983 through 1986 for hip height and backfat, whereas others, except chest measurements (depth and width) that were available only in 1985, were taken from 183 progeny born in 1985 and 1986. The objective of this portion of the study was to determine whether differences in linear body measurements exist between progeny of high- and low-feed-conversion sires. Differences between progeny of high- and low-feed-conversion sires tended to exist (P < .10) for heart girth (176.3 +/- 1.2 vs 173.2 +/- 1.2 cm) and were significant for backfat thickness (.94 +/- .01 vs .87 +/- .02 cm). No significant differences were observed for hip height (115.3 +/- .5 vs 115.5 +/- .5 cm), chest depth (58.8 +/- .6 vs 57.4 +/- .6 cm), chest width (44.4 +/- .5 vs 44.0 +/- .5 cm), head width (21.2 +/- .2 vs 21.1 +/- .2 cm), head length (42.4 +/- .3 vs 41.6 +/- .3 cm), muzzle circumference (41.0 +/- .4 vs 41.6 +/- .3 cm), length between hooks and pins (46.7 +/- .5 vs 46.2 +/- .5 cm), length between shoulder and hooks (94.9 +/- 1.0 vs 93.1 +/- 1.0 cm), or volume (361,199 +/- 4,885 vs 352,718 +/- 5,026 cm3).

Challenges and opportunities for integrating genetically modified animals into traditional animal breeding plans

Techniques have been developed to introduce specific genes from one species into the germplasm of another, including livestock. This paper reviews reports on evaluation, selection, and breeding procedures for introduction and multiplication of transgenes in breeding populations of livestock. Before transgenes are introduced and multiplied in commercial breeding populations, it is necessary to test transgenics extensively for both favorable and unfavorable transgene effects. Parent stock used to produce transgenic founder animals should be selected to excel in polygenic breeding value for economically important traits, especially if founder animals or their sons are to be used directly by AI in commercial populations. However, polygenic breeding value of founder transgenic animals and inbreeding depression are of negligible importance if a transgene is introgressed into a selection nucleus population from three or four generations of backcrossing. Transgenic development should be economically viable for traits with major effects on net merit, especially in the dairy industry, where transgenic sires can be used extensively by AI. A minimum effect of about 10% of the mean (or one phenotypic standard deviation) is a reasonable approximation of the minimum transgene effect that would be necessary to justify introgression into a nucleus swine population. A transgene effect of 10 to 20% of the mean would be required for most economic traits in beef cattle.

Divergent selection for postweaning feed conversion in Angus beef cattle: I. Mean comparisons

Each year from 1979 through 1983, 35 Angus bull calves were selected from a herd at the Eastern Ohio Resource Development Center to be individually fed in a 140-d postweaning performance test. From these 35 individually fed bulls, the three highest and three lowest for feed conversion (feed:gain) were selected and randomly mated to approximately 20 cows each. A different set of high vs low feed conversion sires was used each year. Four replicates (403 progeny) from high vs low sires were evaluated by sire groups for subsequent postweaning and carcass performance. Progeny were slaughtered when estimated by ultrasonic measurement to have 8.9 mm or more of subcutaneous fat at the conclusion of a 140-d postweaning performance test. Progeny with less than 8.9 mm of subcutaneous fat were fed for additional 28-d periods until they reached the required minimum. No differences were found between high and low feed conversion progeny for 140-d feed intake (P less than .30) although high feed conversion progeny gained .09 kg/d more weight (P less than .01) during the 140-d postweaning test. Differences tended to exist between high and low feed conversion progeny for unadjusted (P less than .15) and maintenance-adjusted (P less than .15) feed:gain ratios. Progeny of the high feed conversion group had greater subcutaneous fat (P less than .05) at the end of the 140-d postweaning test and when slaughtered (P less than .05), indicating a genetic difference for composition of BW gain between high- and low-sired progeny. However, no significant differences existed for any other carcass traits evaluated. Bulls had more desirable unadjusted (P less than .001) and maintenance-adjusted (P less than .001) feed:gain ratios than heifers with increased 140-d ADG (P less than .001) and pen feed intakes (P less than .001).