3 TESTIS-SPECIFIC PROTEIN, Y-ENCODED (TSPY) COPY NUMBER AND EXPRESSION IN BOVINE BLASTOCYSTS

Testis-specific protein, Y-encoded (TSPY) is a gene found on the Y chromosome that, like many genes on the Y chromosome of mammalian species, has multiple copies. Humans have between 20–60 copies, whereas cattle can have up to 200 copies. Genomic copy number of TSPY is of interest because it has been linked to fertility. In previous studies, enormous bull-to-bull variation in TSPY copy number has been found (Hamilton et al. 2009 Sex. Dev. 3, 205–213). The aims of this study were to a) examine the copy number of TSPY in brother embryos to see if variation exists among embryos of a single generation and b) to determine if TSPY mRNA (mRNA) is expressed in the early bovine embryo since there is evidence from transgenic mice studies that human TSPY may play a role in development. 80 Holstein blastocysts were produced using standard in vitro fertilization techniques with the semen of a single bull. Individual blastocysts (n = 50) were lysed and quantitative polymerase chain reaction (qPCR) was used to sex the embryos and to measure TSPY copy number in the embryos that were found to be male. The male-specific TSPY and SRY (sex determining region Y) genes were measured in order to sex the embryos along with ZAR1 (zygote arrest protein 1), as an autosomal control. TSPY copy number was measured with a modified 2ΔΔCT method (Hamilton et al. 2009 Sex. Dev. 3, 205–213) and SRY as the single copy reference gene. Messenger RNA was extracted from two pools of blastocysts (n = 20, n = 10) and reverse transcribed into cDNA. The presence of TSPY mRNA in these pools was determined with reverse transcription PCR (RT–PCR) along with the reference gene GAPDH, following standard protocols. Briefly, two sets of TSPY specific primers and one set of GAPDH specific primers were used to amplify the target mRNAs in both pools of embryos using AmpliTaq Gold DNA polymerase (Applied Biosystems) and an annealing temperature of 60°C. PCR products were visualised on a 2% gel using gel electrophoresis and then sequenced to verify specificity of the primers. The results of the embryo sexing experiment showed a 50:50 sex ratio (25 males, 25 females) in the group of individual embryos. TSPY copy number was found to vary significantly (using a one-way ANOVA, P < 0.0001) among brother embryos produced from the semen of the same Hostein bull (n = 25) and ranged from 21.9 ± 7.1 to 159.0 ± 14.0 copies, with an average of 65.9 ± 6.3 copies. Furthermore, the results of the expression experiment showed that TSPY mRNA transcripts were present in both pools of blastocysts. These results provide the first evidence that TSPY is expressed in bovine blastocysts and that copy number can vary within a single generation. This data suggests that the bovine Y chromosome is a dynamic chromosome that is not clonally inherited but can vary its genetic composition within a single generation. The fact that TSPY transcripts were found in the early embryo suggests that it might have another function other than simply a role in spermatogenesis. Supported by National Sciences Engineering and Research Council grant; Canadian Research Chair program; and L’Alliance Boviteq Inc.

A genetically modified mouse model probing the selective action of ifenprodil at the N-methyl-d-aspartate type 2B receptor

Selective antagonism of N-methyl-d-aspartate (NMDA) 2B subunit containing receptors has been suggested to have potential therapeutic application for multiple CNS disorders. The amino terminal NR2B residues 1 to 282 were found to be both necessary and sufficient for the binding and function of highly NR2B subunit specific antagonists like ifenprodil and CP-101,606. Using a genetic approach in mice, we successfully replaced the murine NR2B gene function by "knocking-in" (KI) a chimeric human NR2A/B cDNA containing the minimal domain abolishing ifenprodil binding into the endogenous NR2B locus. Patch-clamp recording from hippocampal cultures of the NR2B KI mice demonstrated that their NMDA receptors have reduced sensitivity to both ifenprodil and CP-101,606, as predicted, but also have a lower affinity for glycine. The NR2B KI mice exhibited normal locomotor activity making this ifenprodil-insensitive mouse model a valuable tool to test the specificity of NR2B selective antagonists in vivo.

Development of a community-based medical rehabilitation programme in the Kivalliq Region of Nunavut, Canada

OBJECTIVE

In 2000, the University of Manitoba and the Department of Health and Social Services of Nunavut, Canada, jointly embarked upon the development of a community-based medical rehabilitation programme in the Kivalliq Region of Canada's central Arctic. Two main objectives were identified in moving forward with the implementation of a rehabilitation programme. Firstly, to conduct a region wide community needs assessment for rehabilitation services for all age groups of all residents of the Kivalliq Region of Nunavut. Secondly, to provide information from which a community-based rehabilitation therapy programme could be developed.

METHODS

A community needs assessment of the Kivalliq Region was carried out to guide the implementation of physiotherapy, occupational therapy and speech language pathology services.

RESULTS

There are now two physiotherapists, one occupational therapist, and one speech language pathologist providing rehabilitation services to the residents of the Kivalliq Region of Nunavut. The results of this needs assessment, the challenges and successes of this medical rehabilitation programme are discussed.

CONCLUSION

The total population of the service area is approximately 8,000 people, the significant majority of whom self-report as Inuit, and are widely dispersed over eight communities. Despite the challenges in terms of culture, geography and recruitment of introducing a rehabilitation program in Canada's north, the residents of the Kivalliq Region now have a viable model of receiving rehabilitative intervention in their home communities.

Speech language pathology services in Kivalliq Region of Nunavut, Canada

OBJECTIVES

To provide a review of Speech Language Pathology services in the Kivalliq Region of Nunavut, Canada, since its inception. Referral sources, reasons for referral and discharge will also be shown for seven of the communities in the Kivalliq Region.

STUDY DESIGN

A quantitative and qualitative survey of the services received for the 26-month time period from January 2001 to February 28th, 2003.

METHODS

A record review of Speech Language Pathology services was conducted. Referral sources in each community, the rate of referrals, reasons for discharge and changes in abilities of three clients were examined.

RESULTS

The rate of referrals increased as the service became more familiar. Small increases in client abilities were noted over the specified time period.

CONCLUSION

Speech Language Pathology services are being utilized more effectively as the referral sources become more familiar with the program.

Community based physiotherapy services in the Kivalliq Region of Nunavut, Canada

OBJECTIVES

Community based physiotherapy services are an integral component of the recent implementation of a medical rehabilitation program in the Kivalliq Region of Nunavut. Since the year 2000, the Inuit people of Canada's central Arctic have had direct access to physiotherapy in their home communities.

STUDY DESIGN

A quantitative review of physiotherapy services from January 1, 2001 to December 31, 2002.

METHODS

Workload measurement data gathered by the physiotherapists in the field will be utilized to present information on referral sources, location of services provided, client diagnoses and average duration of treatment provided. Administrative data will provide information on staffing complements and challenges to date. The need for physiotherapy referrals out of the Kivalliq Region will be reviewed.

RESULTS

Referral sources to physiotherapy services are varied, the majority of diagnoses are musculoskeletal in nature, followed by neurological and cardiovascular. Recruitment of the physiotherapy positions has been successful to date. Referrals out of the region for physiotherapy services have been rare since community based services have begun.

CONCLUSIONS

Access to physiotherapy services by the residents of the Kivalliq Region has been significantly enhanced since the implementation of the medical rehabilitation program.

NR2B-Selective N-Methyl-d-aspartate Antagonists: Synthesis and Evaluation of 5-Substituted Benzimidazoles

Two classes of 5-substituted benzimidazoles were identified as potent antagonists of the NR2B subtype of the N-methyl-d-aspartate (NMDA) receptor. Selected compounds show very good selectivity versus the NR2A, NR2C, and NR2D subtypes of the NMDA receptor as well as versus hERG-channel activity and alpha(1)-adrenergic binding. Benzimidazole 37a shows excellent activity in the carrageenan-induced mechanical hyperalgesia assay in rats as well as good pharmacokinetic behavior in dogs.

Novel N1-(benzyl)cinnamamidine derived NR2B subtype-selective NMDA receptor antagonists

Novel (E)-N(1)-(benzyl)cinnamamidines were prepared and evaluated as NR2B subtype NMDA receptor ligands. Excellent affinity was achieved by appropriate substitution of either phenyl ring. The 2-methoxybenzyl compound 1h had approximately 1,000-fold lower IC(50) in NR2B than NR2A-containing cells. Replacement of the styryl unit by 2-naphthyl was well tolerated.

Orally efficacious NR2B-selective NMDA receptor antagonists

A novel series of benzamidines was synthesized and shown to exhibit NR2B-subtype selective NMDA antagonist activity. Compound 31 is orally active in a carrageenan-induced rat hyperalgesia model of pain and shows no motor coordination side effects.

N-Methyl-D-aspartate receptor subtype-selectivity of homoquinolinate: an electrophysiological and radioligand binding study using both native and recombinant receptors

Homoquinolinate, a derivative of the endogenous NMDA agonist, quinolinate, has been shown to display higher affinity for Xenopus oocytes expressing NR2A- and NR2B-containing receptors, compared to NR2C- and NR2D-containing receptors, whilst autoradiographical experiments subsequently showed that [3H]homoquinolinate labelled a subpopulation of NMDA receptors in rat brain sections, with a similar distribution to NR2B-containing receptors. In this study, we have shown that NMDA-specific [3H]homoquinolinate binding to rat brain membranes comprised 44% of total binding with a Bmax value of 5.73 pmol/mg protein, which was inhibited by NMDA with Ki=0.867 micro m. However, NMDA-specific [3H]homoquinolinate binding was not observed for a number of human recombinant NMDA receptors investigated, suggesting that there are subtle differences between the binding sites of recombinant and native receptors. Electrophysiological experiments revealed that homoquinolinate activated human recombinant NR1a/NR2A, NR1a/NR2B and NR1a/NR2A/NR2B receptors with EC50 values of 25.2, 13.8 and 9.04 micro m, respectively, with intrinsic activities of 148, 93.3 and 125%, respectively, compared to glutamate (=100%). In contrast to an autoradiographical study, these radioligand binding and electrophysiological experiments suggest that homoquinolinate is not highly selective for NR2B-containing receptors.

Rapid pharmacotherapeutic intervention for an influenza A outbreak in the Canadian Arctic: lessons from the Sanikiluaq experience

In January of 2000 an outbreak of influenza-like illness (ILI) was identified by Health Centre nursing staff in the remote island Inuit community of Sanikiluaq, Nunavut. A staged approach to an intervention strategy was adopted and an intervention team dispatched within 48 hours with diagnostic, prophylactic, and therapeutic capabilities and the intent to evaluate the response as well. The presence of influenza virus was determined on site in 3 out of thirteen initial cases of ILI using portable kit based rapid detection. This permitted the use of zanamivir (an inhaled neuraminidase inhibitor) for prophylaxis in 201, and for treatment in 12 persons. Amantadine was only used in 16 and 52 were ineligible for medical intervention, mostly because they fell outside of the window of opportunity or for maternal/reproductive reasons. The intervention strategy framework adopted was felt to be successful and is presented for consideration in future intervention initiatives.

The Knee Society Index of Severity for failed total knee arthroplasty: practical application

Previous classifications of severity for total knee arthroplasty revisions have been based largely on bone loss of the femur and tibia. These approaches failed to address the more technically difficult issues in revision surgery such as surgical exposure, contractures, extremity alignment, implant removal, soft tissue stability (in the anteroposterior and in the sagittal planes), extensor mechanism integrity, and patellar revisability. Through the Knee Society, the authors developed a severity index that incorporated these latter factors into one measure. The current authors describe the application of the Knee Society Index of Severity for failed total knee arthroplasty and its method of scoring.

The Knee Society Index of Severity for failed total knee arthroplasty: development and validation

Compared with primary knee replacement, total knee arthroplasty revision surgery is a more complex procedure and accounts for greater expenditures of healthcare resources at each clinical stage. Overall, patients having revision procedures have poorer functional outcomes and higher complication rates than patients having primary arthroplasty. Despite the expanded scope of revision problems and the rapidly emerging technology in revision surgery, the long-term success of any method remains in question. Because there is little consensus on the timing of revision surgery, optimal surgical reconstruction, and the type of prosthesis to be implanted, the Knee Society began development of an Index of Severity for Failed Total Knee Arthroplasty. Fifty-four percent of Knee Society members completed an 82-item questionnaire that determined their clinical impression about potential risk factors for the outcomes of revision surgery for failed total knee replacements. Using these results, a consensus group developed the final version of the index. The result of the nominal group process was the Knee Society Index of Severity, which was based on eight distinct domains. Each domain was divided into attributes and weights based on the questionnaire responses and consensus meeting. Actual case scenarios from five institutions were used to test interrater reliability and validity. The interrater reliability of the average score of all ratings was 0.95; the correlation of the criterion rating with the mean rating was 0.77. When three outliers were not included, the Pearson product correlation increased to 0.92. These data support the application of the Knee Society Index of Severity as a critical component of risk factor studies, effectiveness research, and cost-effectiveness analysis involving revisions of total knee replacements.

Loss of the major GABA(A) receptor subtype in the brain is not lethal in mice

The alpha1beta2gamma2 is the most abundant subtype of the GABA(A) receptor and is localized in many regions of the brain. To gain more insight into the role of this receptor subtype in the modulation of inhibitory neurotransmission, we generated mice lacking either the alpha1 or beta2 subunit. In agreement with the reported abundance of this subtype, >50% of total GABA(A) receptors are lost in both alpha1-/- and beta2-/- mice. Surprisingly, homozygotes of both mouse lines are viable, fertile, and show no spontaneous seizures. Initially half of the alpha1-/- mice died prenatally or perinatally, but they exhibited a lower mortality rate in subsequent generations, suggesting some phenotypic drift and adaptive changes. Both adult alpha1-/- and beta2-/- mice demonstrate normal performances on the rotarod, but beta2-/- mice displayed increased locomotor activity. Purkinje cells of the cerebellum primarily express alpha1beta2gamma2 receptors, and in electrophysiological recordings from alpha1-/- mice GABA currents in these neurons are dramatically reduced, and residual currents have a benzodiazepine pharmacology characteristic of alpha2- or alpha3-containing receptors. In contrast, the cerebellar Purkinje neurons from beta2-/- mice have only a relatively small reduction of GABA currents. In beta2-/- mice expression levels of all six alpha subunits are reduced by approximately 50%, suggesting that the beta2 subunit can coassemble with alpha subunits other than just alpha1. Our data confirm that alpha1beta2gamma2 is the major GABA(A) receptor subtype in the murine brain and demonstrate that, surprisingly, the loss of this receptor subtype is not lethal.

Sedative but not anxiolytic properties of benzodiazepines are mediated by the GABA(A) receptor alpha1 subtype

Inhibitory neurotransmission in the brain is largely mediated by GABA(A) receptors. Potentiation of GABA receptor activation through an allosteric benzodiazepine (BZ) site produces the sedative, anxiolytic, muscle relaxant, anticonvulsant and cognition-impairing effects of clinically used BZs such as diazepam. We created genetically modified mice (alpha1 H101R) with a diazepam-insensitive alpha1 subtype and a selective BZ site ligand, L-838,417, to explore GABA(A) receptor subtypes mediating specific physiological effects. These two complimentary approaches revealed that the alpha1 subtype mediated the sedative, but not the anxiolytic effects of benzodiazepines. This finding suggests ways to improve anxiolytics and to develop drugs for other neurological disorders based on their specificity for GABA(A) receptor subtypes in distinct neuronal circuits.

Teenage Concerns about the Physical Examination

A study of teenagers' thoughts about doctor/patient relationships revealed a high level of discomfort deriving from the physical examination. Our report attempts to clarify the indications for genital and breast examination and techniques for performing these exams in a manner least distressing to teenagers.