A Prematriculation Intervention to Improve the Adjustment of Students to Medical School

Background and purpose: The transition from a baccalaureate program to a medical curriculum can be a difficult period for some students. Our study asked whether providing students with review materials and a means of assessing their degree of preparedness prior to matriculation influenced actual and perceived performance in 1st-year basic science courses. Methods: Didactic review materials in basic science subjects encountered in the 1st year were made available to prematriculants online. Access to materials for each subject was contingent upon completion of a pretest. Prematriculants were free to use the materials as they saw fit. Once students matriculated, performance in basic science subjects was compared between those who had accessed the materials and those who had not. Students who accessed the materials were also surveyed to determine if they perceived any benefit from their use. Results: More than half of matriculants chose to access the intervention materials. There was no significant difference in MCAT, prerequisite grade point average, or total grade point average between those students who chose to access the intervention materials and those who did not. Students who accessed the intervention materials reported gains in confidence in their ability to perform well in medical school. Those students who accessed the intervention materials had significantly higher examination scores in an early basic science course than those who did not. Conclusions: An online prematriculation intervention can provide useful background material to interested students. Access to this material increased performance in a 1st-year basic science course and was perceived as valuable by students.     

The utility of a HindIII polymorphism of factor VIII examined by rapid DNA analysis

A previously described HindIII restriction fragment length polymorphism (RFLP) of factor VIII (FVIII) has its polymorphic site in the unsequenced nineteenth intron. We have located the polymorphic site, as well as an invariant site, by amplifying and sequencing IVS 19 using the polymerase chain reaction (PCR). The oligonucleotide primers were synthesized from known FVIII sequence on either side of the 19-20 splice junction. The amplified product was cloned into a plasmid and sequenced by the dideoxy chain termination method. The polymorphic HindIII site was 103 bp and the invariant site 184 bp from the 3' end of the nineteenth exon. The frequency of the polymorphism was determined in 457 subjects (643 chromosomes) of seven ethnic groups on whom frequency of the BclI RFLP of IVS 18 was also assessed. The HindIII site is highly polymorphic in all groups, approximately 0.25:0.75, the expected heterozygosity averaging 37.6%, and the observed number of heterozygotes did not differ significantly from expectation. The (+):(-) allelic ratio is similar in all groups, except African-Americans in whom it is reversed. Strong allelic association (linkage disequilibrium) is present between the HindIII polymorphism of IVS 19 and the BclI polymorphism of IVS 18.     

Role of the Fastigial Nucleus in Generalized Seizures as Demonstrated by GABA Agonist Microinjections

The cerebellum is electrically and metaboli cally active during seizures. Numerous studies have also shown that cerebellar electrical stimulation and lesions of the cerebellar cortex or nuclei influence seizure thresh old, but there are significant contradictions, with different effects observed even in investigations using the same species and similar seizure types and experimental ma nipulations. Discrete intracerebral microinjection of neu roactive agents has been used to characterize the way in which other brain regions control seizures, but has not been applied to the cerebellar systems. This approach has advantages because effects are restricted to specific re ceptors and spare passing axons; experimental variables also can be simply specified and reproduced. We used this method to characterize the role of the cerebellar nu clei in seizures and to determine if observed effects could be reproduced with different agents at different doses. Effects of bilateral control microinjections in the fastigial (medial) cerebellar nucleus were compared with different doses of the GABA_A agonist piperidine-4-sulfonic acid and the GABA_B agonist (?)baclofen (Bf). Soon after in jection, the animals were ataxic. After 4 min, seizures were induced by timed continuous intravenous (i.v.) bicu culline (BIC) infusion. Both GABA agonists produced significant reductions in myoclonic, clonic, and tonic sei zure thresholds. Injections just dorsal or anterior to this nucleus and bilateral dentate (lateral) nucleus injections had little effect on seizures. These results demonstrate that the cerebellar system does control seizures, but does not provide support for the early concept that cerebellar stimulation and systemic phenytoin block seizures through inhibition of cerebellar nuclei secondary to Pur kinje cell activation.