Predictive value of a senior comprehensive examination as to performance on a national certification examination.

OBJECTIVE: To determine what value a senior departmental comprehensive examination holds in predicting the future success of a student on the MT(ASCP) certification examination. DESIGN: Part 1: To evaluate the efficacy of the comprehensive examination, scores were obtained in the examination categories of hematology, clinical chemistry, immunohematology, and microbiology for all dinical laboratory science students who have graduated from the University of Mississippi Medical Center since 1993. The data were analyzed to determine if a correlation exists between student performance on the senior comprehensive, and their future performance on the MT(ASCP) national certification examination. Part 2: To determine the extent to which a senior comprehensive examination was required for graduation at other university-based clinical laboratory science programs, a simple survey was e-mailed to members of the clinical laboratory science educators forum. SETTING: 2+2 university-based dinical laboratory science program PARTICIPANTS: Part 1: Previous graduates of the Clinical Laboratory Science Program at the University of Mississippi Medical Center since 1993. Part 2: Program directors who are members of the Clinical Laboratory Sciences Educator's Forum. RESULTS: Part 1: Results indicated a distinct division between participants who scored higher than 74.36% (Group A) on the senior comprehensive examination, and those scoring below 74.36% (Group B). In Group A, 100% of participants passed the MT(ASCP) national certification examination on the first attempt. Results were mixed for Group B. Part 2: The survey indicated that of the 40 respondents, most were similar to the University of Mississippi Medical Center Clinical Laboratory Science Program in that they require a comprehensive to be taken, that the grade received is part of another course grade, and that the examination is prepared using questions submitted by the faculty. CONCLUSIONS: Part 1: The senior departmental comprehensive examination is of value in predicting the future success of a student on the MT(ASCP) national certification examination. Part 2: Unlike the University of Mississippi Medical Center, 16 of the 40 respondents stated that passage of the comprehensive examination was a requirement for graduation. In those programs, the comprehensive was a major part of a course grade.

Reverse transcriptase-polymerase chain reaction amplification and partial sequence of T helper 1- and T helper 2-type lymphokine genes from the owl monkey (Aotus trivirgatus).

The reverse transcriptase-polymerase chain reaction (RT-PCR) was used to amplify selected lymphokine mRNAs from phytohemagglutinin-activated leukocytes of the owl monkey (Aotus trivirgatus). Interleukin-2 (IL-2), IL-4, IL-13, and interferon-gamma were selected as lymphokine mRNAs of interest, since expression of these cytokines helps define the type of T helper lymphocyte response (i.e., TH1 versus TH2). Because sequences for these lymphokine genes were not available for the owl monkey, multiple PCR primers for each lymphokine gene were designed based on published human sequences. Various PCR primer pairs were then used in the RT-PCR to determine the conditions for optimal amplification of each owl monkey cytokine mRNA. In addition, each PCR primer pair was compared for the ability to amplify lymphokine mRNAs from other primate species, including African green (Cercopithecus aethiops), squirrel (Saimiri sciureus), and rhesus (Macaca mulatta) monkeys. The specificity and sensitivity of optimal primer pair was also demonstrated by amplification of as little as 10 fg of each lymphokine gene in a background of 300 ng of irrelevant cDNA. Finally, partial sequences of owl monkey coding regions for IL-2, IL-13, and interferon-gamma were determined and compared for homology with their human counterparts. Together, these studies define specific and sensitive conditions for detection of lymphokine mRNA expression in the owl monkey and provide partial sequence information of the coding region for these lymphokines. This investigation should provide molecular probes to investigate the immune response against malaria and the effectiveness of malaria vaccines in the owl monkey that models this human disease.

In vivo treatment with anti-interleukin-13 antibodies significantly reduces the humoral immune response against an oral immunogen in mice.

Interleukin-13 (IL-13) is a cytokine which significantly enhances the proliferation and differentiation of B lymphocytes. We therefore evaluated its role in the formation of a humoral immune response in vivo. Upon oral immunization with the B subunit of Escherichia coli heat-labile enterotoxin (LT-B), rapid up-regulation of IL-13 mRNA expression in the mesenteric lymph nodes of LT-B intubated mice occurred. This result suggested that IL-13 might be involved in the formation of a mucosal antibody response against LT-B if this cytokine was in fact secreted. To test this possibility, the coding region for murine IL-13 was cloned into the pFLAG-1 expression vector. Recombinant murine IL-13 was purified from bacterial lysates and used as an immunogen to produce polyclonal anti-IL-13 antibodies. Groups of BALB/c mice treated in vivo with anti-IL-13 antibody 2 days before and on the day of oral immunization with LT-B had significantly reduced intestinal IgA and serum IgG and IgA anti-LT-B antibody responses when compared to mice treated with control antibody. Furthermore, groups of mice primed with LT-B and then treated with anti-IL-13 antibody prior to oral immunization with a second dose of LT-B also had significantly reduced intestinal IgA and serum IgG and IgA anti-LT-B antibody titres compared to controls. In vitro LT-B restimulation experiments using splenic mononuclear leucocytes isolated from LT-B primed mice treated with anti-IL-13 antibody demonstrated decreased expression of IL-4 and IL-13 mRNA and decreased IL-4 secretion when compared to controls. Together these results demonstrate an important role for IL-13 in the formation of a humoral immune response at mucosal surfaces.

Vasodilator responses to desmopressin and its diluent, chlorobutanol, in the hindquarters vascular bed of the cat.

Desmopressin is a synthetic analog of vasopressin used to promote hemostasis and reduce postoperative blood loss. Recent studies have shown that desmopressin decreases arterial blood pressure in the anesthetized rat and relaxes isolated segments of aorta and pulmonary artery. Responses to a clinical preparation of desmopressin were investigated in the hindquarters vascular bed of the cat under constant flow conditions so that changes in perfusion pressure directly reflect changes in vascular resistance. Responses to desmopressin and its vehicle, and the effect of receptor antagonists, inhibitors of prostaglandin, and nitric oxide synthesis inhibitors, were investigated.

The Epstein-Barr virus genome encodes deoxythymidine kinase activity in a nested internal open reading frame.

The Epstein-Barr virus (EBV) BXLF1 fragment open reading frame (LORF), though to encode deoxythymidine kinase (dTK) activity, and a shorter frame (SORF), starting at an internal in-frame AUG, were isolated by polymerase chain reaction from a plasmid containing the EcoR1 fragment of EBV strain FF-41. These were transfected into dTK-Escherichia coli, producing multiple SORF- or LORF-containing colonies, which expressed dTK. The 243 NH2-terminal residues of the LORF-encoded polypeptide thus are not essential for dTK activity. SORF, with 1,092 bp, is predicted to encode a 36- to 37-kD polypeptide, in the size range of other herpesviral dTKs.

Effect of desmopressin acetate on hindlimb perfusion pressure in rats: what is the mechanism?

Desmopressin acetate (DDAVP) is a synthetic analogue of vasopressin used to promote hemostasis and reduce postoperative blood loss. Desmopressin acetate can cause hypotension in humans. Our study evaluated the hemodynamics of rapid administration of DDAVP into the isolated hindlimb in live rats and assessed this response after pretreatment with various antagonists. Thirty male Sprague-Dawley rats (350-450 g) were given intraperitoneal pentobarbital anesthesia (50 mg/kg). Perfusion was set at a rate that gave a control mean hindlimb perfusion pressure (HPP) of 100-120 mm Hg. Rats were assigned to five groups (N = 5, each group), with each rat serving as its own control. As a control, saline solution (in volumes equivalent to those used for the antagonists) was injected into the hindlimb preparation before the agonist injections. Each group received both the clinical preparation of DDAVP (i.e., with preservative) and a laboratory preparation of DDAVP in doses of 0.3-3 ng. Group 1 was tested before and after injection of saline solution control; group 2, before and after propranolol (0.5 mg/kg); group 3, before and after meclofenamate (1.5 mg/kg), a cyclooxygenase inhibitor; group 4, before and after nitroarginine (5 mg/kg) an inhibitor of nitric oxide synthesis; and group 5, before and after atropine sulfate (1 mg/kg). Chlorobutanol (25-75 micrograms), the preservative in the clinical preparation of DDAVP, was tested for changes in HPP in five rats similarly prepared. Systemic mean arterial pressure remained constant during the study. The HPP decreased with increasing doses of the clinical preparation of DDAVP, compared with saline solution controls, whereas no change occurred with the laboratory preparation of DDAVP.(ABSTRACT TRUNCATED AT 250 WORDS)