Can Multiple Mini Interviews work in an Irish setting? A feasibility study.

Multiple Mini Interview (MMI) is a new selection tool for medical school applicants. Developed at McMaster University in 2004 it comprises a series of interview stations designed to measure performance across a range of competencies including communication skills, team work, and ethical reasoning. In September 2012, 109 First Year Medical students underwent the MMI. It consisted of 10 stations. The median total score, out of 150, was 100 (min 63, max 129). Cronbach Alphas for the 10 individual stations range from 0.74 to 0.80. Overall Cronbach Alpha of MMI items was 0.78. Staff and student feedback was positive. The outline cost per student was estimated at Euro 145. This study demonstrates that it is feasible to hold a MMI with acceptable levels of reliability and stakeholder approval in an Irish setting. Further work is ongoing to establish the concurrent and predictive validity of MMI in this cohort of medica students.

Hybrid position and orientation tracking for a passive rehabilitation table-top robot.

This paper presents a real time hybrid 2D position and orientation tracking system developed for an upper limb rehabilitation robot. Designed to work on a table-top, the robot is to enable home-based upper-limb rehabilitative exercise for stroke patients. Estimates of the robot's position are computed by fusing data from two tracking systems, each utilizing a different sensor type: laser optical sensors and a webcam. Two laser optical sensors are mounted on the underside of the robot and track the relative motion of the robot with respect to the surface on which it is placed. The webcam is positioned directly above the workspace, mounted on a fixed stand, and tracks the robot's position with respect to a fixed coordinate system. The optical sensors sample the position data at a higher frequency than the webcam, and a position and orientation fusion scheme is proposed to fuse the data from the two tracking systems. The proposed fusion scheme is validated through an experimental set-up whereby the rehabilitation robot is moved by a humanoid robotic arm replicating previously recorded movements of a stroke patient. The results prove that the presented hybrid position tracking system can track the position and orientation with greater accuracy than the webcam or optical sensors alone. The results also confirm that the developed system is capable of tracking recovery trends during rehabilitation therapy.

Reversible Photoinhibition in Antarctic Moss during Freezing and Thawing.

Tolerance of antarctic moss to freezing and thawing stress was investigated using chlorophyll a fluorescence. Freezing in darkness caused reductions in Fv/Fm (ratio of variable to maximum fluorescence) and Fo (initial fluorescence) that were reversible upon thawing. Reductions in Fv/Fm and Fo during freezing in darkness indicate a reduction in the potential efficiency of photosystem II that may be due to conformational changes in pigment-protein complexes due to desiccation associated with freezing. The absorption of light during freezing further reduced Fv/Fm and Fo but was also reversible. Using dithiothreitol (DTT), which inhibits the formation of the carotenoid zeaxanthin, we found reduced flurorescence quenching during freezing and reduced concentrations of zeaxanthin and antheraxanthin after freezing in DTT-treated moss. Reduced concentrations of zeaxanthin and antheraxanthin in DTT-treated moss were partially associated with reductions in nonphotochemical fluorescence quenching. The reversible photoinhibition observed in antarctic moss during freezing indicates the existence of processes that protect from photoinhibitory damage in environments where freezing temperatures occur in conjunction with high solar radiation levels. These processes may limit the need for repair cycles that require temperatures favorable for enzyme activity.

Proximal upstream flanking sequences direct calcium regulation of the rat prolactin gene.

Previous investigations have shown that Ca2+ strongly and specifically stimulates endogenous PRL gene expression by GH3 cells. In this study, addition of Ca2+ to Ca2+-deprived GH3 cells yielded a large (ca. 8-fold) stimulation of transient expression of a transfected PRL-chloramphenical acetyltransferase (CAT) construct containing ca. 1 kilo-base-pair of the PRL promoter region, but only a slight (less than or equal to 2-fold) nonspecific stimulation of CAT activity directed by any of three control promoters: dihydrofolate reductase, Rous sarcoma virus, or thymidine kinase. In GH3 cells never deprived of Ca2+, expression of a PRL-CAT construct was specifically stimulated and inhibited, respectively, by the dihydropyridine voltage-dependent Ca2+ channel modulators Bay K8644 and nimodipine; Ca2+ can thus regulate expression of an exogenous PRL promoter in cells incubated under physiological Ca2+ conditions. By employing a combined protocol, in which Ca2+-deprived cells are exposed to Ca2+ in the presence of Bay K8644, a very large (greater than 35-fold) but still promoter-specific induction of expression of a PRL-CAT construct was obtained. Analysis of 5'-deleted PRL-CAT constructs implied that the PRL gene Ca2+ response element is contained entirely within the first 174 base pairs of upstream flanking DNA sequence.

Proximal rat prolactin promoter sequences direct optimal, pituitary cell-specific transcription.

Previous studies have shown that transferred hybrid constructs containing the PRL promoter are expressed specifically in rat pituitary (GH) cell lines. However, it is not yet clear which DNA region(s) is primarily responsible for expression directed by this promoter in pituitary cells. In the present studies we have examined the DNA sequences required for cell type-specific transcription of the rat PRL (rPRL) promoter either during transient expression in intact cells or in nuclear chromatin extracts. RNase protection and nuclear run-on transcription assays showed directly that a PRL-chloramphenicol acetyltransferase (CAT) construct containing about two kilobase-pairs of the rPRL promoter region (pPRL-CAT) is transcribed specifically in pituitary (GH3) cells. Analysis by transient expression in GH3 cells of pPRL-CAT and its 5' deletions showed that 1) deletion of sequences between positions -1957 and -958 did not significantly affect CAT activity; 2) the first 187 basepairs (bp) of the rPRL promoter directs full CAT activity; and 3) 98% of this activity is accounted for by rPRL DNA sequences between positions -187 and -113, containing two GH3 chromatin footprinting sites. Analysis in GH3 cell nuclear extracts showed that transcription of PRL-CAT constructs is unaffected by successive 5' deletions from position -1957 to -187, and that further deletion to -75 yielded only a moderate (approximately 2-fold) decrease in transcription.(ABSTRACT TRUNCATED AT 250 WORDS)

Calcium channel agonists and antagonists: effects of chronic treatment on pituitary prolactin synthesis and intracellular calcium.

PRL synthesis by GH cells in culture has previously been shown to increase when calcium is added to cultures grown in calcium-depleted medium or when cultures are treated for 18 h or longer with the dihydropyridine calcium channel agonist BAY K8644, whereas the antagonist nimodipine inhibits PRL. The experiments described here were designed to test whether differences in PRL synthesis caused by the dihydropyridines are due to changes in PRL mRNA levels, whether structurally different classes of calcium channel blockers alter PRL production, and whether long term treatment with calcium channel agonists and antagonists alters intracellular free calcium, [Ca2+]i. PRL synthesis and PRL mRNA levels were increased similarly by BAY K8644 and decreased in parallel by the dihydropyridine antagonist nimodipine, while overall protein and RNA synthesis were not changed by either the agonist or antagonist. Two calcium channel blockers which act at different sites on L-type channels than the dihydropyridines also inhibited PRL synthesis without affecting GH; 5 microM verapamil reduced PRL by 64% and 15 microM diltiazem by 89%. Partial depolarization with 5-25 mM KCl increased PRL synthesis up to 2-fold. The intracellular free calcium ion concentration was estimated by Quin 2 and averaged 142 nM for control cultures in normal medium, and 128 and 168 nM for cultures treated 72 h with nimodipine or BAY K8644, respectively. Nimodipine totally prevented the calcium rise obtained upon depolarization.(ABSTRACT TRUNCATED AT 250 WORDS)

Use of a selectable reporter for the isolation of mammalian regulatory genes.

A general method is described for isolating the genes encoding differentiation-specific activators of transcription using genetic selection. Employing regulation of the prolactin encoding gene (PRL) as a model, we have shown that the hamster dihydrofolate reductase-encoding gene (dhfr) is an effective dominant selectable reporter in this methodology. The dhfr coding region was ligated to the rat PRL promoter, and the resultant construct was stably transfected into DHFR- Chinese hamster ovary (CHO) cells, where it had little or no activity. Transfection of these cells with plasmid DNA, containing the coding region of a pituitary-specific transcription factor (Pit-1/GHF-1) in a eukaryotic expression vector, resulted in transfectants in which activation of the chimeric construct, pPRLdhfr, had occurred, enabling these cells to be selected on the basis of their DHFR+ phenotype. Our results suggest that this strategy could be used to isolate unknown genes that regulate a variety of differentiated functions.

Binding of trifluoperazine and fluorene-containing compounds to calmodulin and adducts.

Calmodulin can be specifically acylated with a fluorene-containing hydrophobic spin-labeling reagent at just Lys 75 or at Lys 75 and Lys 148. The binding of trifluoperazine to calmodulin and the two adducts was determined using a Hummel-Dreyer procedure, and binding of the phenothiazine was found to be characterized by apparent positive cooperativity and an apparent limiting stoichiometry of about seven binding sites per protein molecule. Two non-reactive fluorene-containing compounds were synthesized, and both reagents exhibited far less binding to calmodulin than did trifluoperazine. One of these was also assayed for binding to the monolabeled adduct, and this binding was about half that observed with calmodulin and was non-cooperative. Thus, the qualitative and quantitative binding parameters of hydrophobic groups to calmodulin can be quite different.

Epidermal growth factor and phorbol ester regulate prolactin gene expression via distinct pathways.

Previous studies, involving phosphorylation of cytoplasmic proteins and localization of DNA regulatory elements, have suggested that epidermal growth factor (EGF) and 12-O-tetradecanoylphorbol-13-acetate (TPA) have similar actions on prolactin (PRL) gene expression by pituitary (GH) cells. However, little is presently known about whether the actions of these two factors involve common gene-distal intermediates. In the present study, we have employed two approaches to examine this question. Chronic exposure of GH3 cells to TPA, which strongly down-regulates protein kinase C activity, completely inhibited acute TPA stimulation of transient expression of a transfected PRL promoter construct ((-187)PRL-CAT), but did not inhibit EGF stimulation of either accumulation of endogenous PRL mRNA or of expression of (-187)PRL-CAT. Furthermore, the acute stimulatory effects of EGF and TPA on expression of (-187)PRL-CAT were additive. Each of these observations implies that EGF and TPA have gene-distal actions on PRL gene expression that are at least partially non-overlapping.

Evaluation of testicular hCG binding in unilaterally cryptorchid rats following administration of ethane dimethane sulphonate (EDS).

Administration of ethane dimethane sulphonate (EDS) (75 mg/kg) to unilaterally cryptorchid rats, results in a rapid decline in serum testosterone levels and a marked reduction in hCG binding to homogenates of scrotal and cryptorchid testes, consistent with the destruction of Leydig cells within the testes as shown by morphological and morphometric analysis. Between 3 and 7 days after EDS, serum LH and FSH levels rise, LH to levels found in castrate rats. hCG binding begins to recover in scrotal testes, reaching 32% of control values 28 days after EDS. However, the recovery of hCG binding to cryptorchid testes is more rapid, reaching 51% of control levels by 21 days which coincides with the re-establishment of serum testosterone to normal levels. Since a different rate of recovery is observed for hCG binding to scrotal and cryptorchid testes, and both testes are exposed to the same circulating levels of LH and FSH, the likely stimulus for recovery of hCG binding and regeneration of Leydig cells is intratesticular in origin. This supports the concept that local factors, released following damage to the seminiferous epithelium by cryptorchidism, play a role in the differentiation and growth of Leydig cells within the testis.

The effects of ethane dimethane sulphonate (EDS) on bilaterally cryptorchid rat testes.

A single dose of ethane dimethane sulphonate (EDS) given to adult male rats has a specific destructive effects on Leydig cells, which are removed from the intertubular area by macrophages. This is associated with a decrease in testosterone (T) and a rise in serum FSH and LH for 21-28 days after EDS. Recovery of Leydig cells occurs from connective tissue precursors. This study uses the bilaterally cryptorchid rat to investigate the influence of local factors from the seminiferous tubules on the restoration of Leydig cell morphology and function. Morphometric data of intertubular tissue, hCG binding, serum T, FSH and LH levels all indicate that the Leydig cell population in cryptorchid testes is more rapidly restored from connective tissue cells when compared to the normal situation. The precise mechanism for this faster recovery will require further study.

Face recognition in children with a pervasive developmental disorder not otherwise specified.

This study investigates the accuracy and speed of face recognition in children with a Pervasive Developmental Disorder Not Otherwise Specified (PDDNOS; DSM-IV, American Psychiatric Association [APA], 1994). The study includes a clinical group of 26 nonretarded 7- to 10-year-old children with PDDNOS and a control group of 65 normally developing children of the same age. Two computerized reaction time tasks were administered: a face recognition task and a control task designed to measure the recognition of abstract visuospatial patterns. The latter were either easy or difficult to distinguish from a set of alternative patterns. The normally developing children recognized the faces much faster than the hardly distinguishable abstract patterns. The children in the PDDNOS group needed an amount of time to recognize the faces that almost equalled the time they needed to recognize the abstract patterns that were difficult to distinguish. The results suggest that, when processing faces, children with PDDNOS use a strategy that is more attention-demanding and, hence, less automatic or "Gestalt-like" than the one used by the control children. The results are discussed in the light of a theory that explains the development of coherent mental representations.

Assessing vulvar lesions. Laser-Doppler flowmetry as a possible technique.

Over the last decade, laser-Doppler flowmetry has been used to measure perfusion in the skin. To date it has not been used on the lower genital tract, and we describe preliminary results of measurements taken on the vulva. We include results from a control population and describe two cases with premalignant or malignant changes in the vulva.

Suppression of testicular function using two dose rates of a reversible water soluble gonadotrophin releasing hormone (GnRH) vaccine in colts.

OBJECTIVE: To investigate the effect of two dose rates (200 and 400 ng) of a gonadotrophin releasing hormone (GnRH) vaccine on testicular function. DESIGN: A vaccination dose rate experiment. PROCEDURE: Two injections were administered 4 weeks apart to six colts in each treatment group. To maintain immunosuppression until the end of the breeding season, a third injection was given if antibody titres fell below 1000. RESULTS: Effective antibody titres were present for 12 to 27 weeks. Testosterone concentrations decreased from 2.22 to 0.31 nmol/L 6 weeks after primary vaccination. Androstenedione concentrations decreased from 1.78 to 0.28 nmol/L 5 weeks after vaccination. Testosterone and androstenedione concentrations above 0.69 and 0.87 nmol/L were attained 31 to 43 weeks after vaccination. Mean scrotal widths and lengths decreased over 29 weeks from 9.2 cm and 9.7 cm to 6.7 cm and 7.6 cm. At surgical castration these dimensions were 10.1 cm and 11.0 cm. Mean semen characteristics before vaccination and after recovery were: gel-free volume 16.5 and 13.5 mL, sperm concentration 295.5 x 10(6) and 315.6 x 10(6)/mL, total sperm per ejaculate 4041 x 10(6) and 4657 x 10(6) and live normal spermatozoa 32% and 60%. Histologically, the testes showed active spermatogenesis. The mean testicular parenchyma weights for the 200 and 400 mg groups were 129.0 g and 109.8 g. Daily sperm production per testis and per gram of testis for the 200 and 400 mg groups were 3.7 x 10(8) and 2.8 x 10(6), and 2.3 x 10(8) and 2.0 x 10(6). CONCLUSIONS: Both dose rates suppressed testicular function. Data showed that the vaccine effects were reversible. Individual immune response was less varied in the 200 mg group. Further work is necessary to achieve a less variable response in the immunosuppression of testicular function.