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.

In vitro efficacy of a novel chemoradiopotentiator--taxoltere metro.

PURPOSE: To evaluate the in vitro cytotoxic and radiopotentiating effects of a novel paclitaxel analog (taxoltere metro) on Chinese hamster ovary (CHO) cells and human colon cancer cells. METHODS AND MATERIALS: Three cell lines (CHO cells, HCT116 human colon carcinoma cells [paclitaxel-sensitive], and VM46 cells [paclitaxel-resistant subline of HCT116]) were employed in this study. Cell survival was determined using the standard colony-forming assay. The ID50 value (drug concentrations required to reduce colony formation to 50% of the control value) was determined as a cytotoxic index from each cell survival curve. The sensitizer enhancement ratio (SER) as a radiopotentiating endpoint was determined as the ratio of the D0 values (with or without drugs) under hypoxic or air conditions. RESULTS: Taxoltere metro was 5-15 times more effective in killing CHO cells than paclitaxel under both hypoxic and euoxic treatment conditions. Cytocidal effects of taxoltere metro on HCT116 cells and VM46 cells were 28 and 70 times higher than those of paclitaxel (p<0.001), respectively. Taxoltere metro also produced significant radiopotentiating effects on euoxic CHO and HCT116 cells, but not on hypoxic cells. The SER value of taxoltere metro for CHO cells was about 2.3 at a dose of 100 nM. With HCT116 cells, taxoltere metro yielded an SER of 1.2 at the low dose of 10 nM. In contrast, the parent compound paclitaxel yielded little or no radiosensitization with either CHO or HCT116 cells. CONCLUSION: The results demonstrate that taxoltere metro is significantly more potent than paclitaxel in chemoradiopotentiating CHO cells and HCT116 human colon carcinoma cells. The data strongly suggest that taxoltere metro could be a promising chemoradiopotentiating agent for treatment of cancer.

Screening of a library of phage-displayed peptides identifies human bcl-2 as a taxol-binding protein.

A random library of phage displayed peptides was screened for binding to a biotinylated derivative of paclitaxel (Taxol). Affinity-selected peptides were analyzed for similarity to human proteins. There was no significant similarity between the paclitaxel-selected peptides and tubulin. However, a subset of the peptides was identified that exhibits significant similarity to a non-conserved region of the anti-apoptotic human protein Bcl-2: ELISA assays confirmed binding of paclitaxel to Bcl-2, and circular dichroism spectroscopy demonstrated that a substantial conformational change accompanies this binding. In vivo, treatment with paclitaxel has been shown to lead to Bcl-2 inactivation with concomitant phosphorylation of residues in a disordered, regulatory loop region of the protein. Similarity between paclitaxel-selected peptides and this loop region implicate these residues in drug binding, and suggest that the apoptotic action of paclitaxel may involve the binding of paclitaxel to Bcl-2. These results demonstrate that peptides displayed on the surface of bacteriophage particles can mimic the ligand-binding properties of disordered regions of proteins.

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.

Correction of congenital indirect hyperbilirubinemia by small intestinal transplantation.

INTRODUCTION: Crigler-Najjar syndrome, type I, is a disease characterized by complete absence of hepatic bilirubin glucuronidation. The congenital indirect hyperbilirubinemia is due to an autosomal recessive deficiency of the enzyme, uridine diphosphate glucuronosyl transferase (UDPGT). The inbred homozygous Gunn rat is also deficient in UDPGT, exhibits unconjugated hyperbilirubinemia, and is an excellent animal model of the Crigler-Najjar syndrome. This study was performed to test the ability of transplanted intestine from normal Wistar rat donors to correct the deficiency in hepatic bilirubin conjugation. MATERIALS AND METHODS: In phase 1, Gunn rats underwent 40-cm heterotopic small-bowel transplants from either Wistar (experimental) or Gunn (control) rats. In phase 2, 15- to 20-cm Wistar-to-Gunn jejunal transplants were placed either heterotopically or orthotopically (in intestinal continuity). All rats were treated with cyclosporin A (CsA), 5 mg/kg per day. Serum bilirubin levels were determined spectrophotometrically at weekly intervals posttransplantation. In phase 2, UDPGT activity was quantitated at 0, 2, 4, and 8 weeks using known quantities of bilirubin as substrate. RESULTS: Total bilirubin levels decreased significantly in the 40-cm heterotopic transplant recipient rats. From the initial values of 7.12 +/- 0.59 mg/dL, levels reached the nadir of 4.23 +/- 0.27 mg/dL. A parallel drop in serum levels of indirect bilirubin was noted (5.04 +/- 0.54 mg/dL to 2.74 +/- 0.23 mg/dL). After 6 weeks, bilirubin levels began to rise toward pretransplant values. In contrast, there was no significant change in bilirubin levels in the control Gunn-to-Gunn rats. Fifteen- to 20-cm heterotopic Wistar-to-Gunn transplants caused a qualitatively similar drop in total and indirect bilirubin levels. Orthotopic (in continuity) Wistar-to-Gunn transplants lowered serum bilirubin levels more rapidly, and the effect was sustained throughout the 8-week study period. By 1 week posttransplantation, total bilirubin levels dropped from 5.11 +/- 0.48 mg/dL to 2.41 +/- 0.16 mg/dL (P < 0.05); data at 8 weeks averaged 1.84 +/- 0.35 mg/dL. Respective data for indirect bilirubin levels were 4.81 +/- 0.45 mg/dL, 2.26 +/- 0.18 mg/dL, and 1.35 +/- 0.39 mg/dL. Wistar rat UDPGT activity in intestine and liver averaged 0.61 +/- 0.05 and 1.88 +/- 0.06 mg bilirubin conjugated/mg tissue per hour, respectively. Enzyme activity in the transplanted intestine persisted throughout the course of the study. CONCLUSION: Transplants of small intestine with known UDPGT activity partially corrected the deficiency in Gunn rats and allayed the hyperbilirubinemia. Since the small intestine is known to contain small but significant amounts of a large number of predominantly hepatic enzymes, bowel transplantation may be an appropriate treatment for this and other similar genetic enzyme deficiencies.

Does ketorolac tromethamine, a new analgesic, decrease postoperative recovery time, narcotic requirements, nausea and/or vomiting, and unscheduled hospital admissions: a retrospective analysis.

This study retrospectively evaluated patients receiving intramuscular ketorolac for postoperative analgesia as compared to intravenous narcotics. Ninety-eight patients' charts were reviewed. Forty-nine subjects who received ketorolac postoperatively (intramuscularly) when entering the post anesthesia recovery unit, were matched with forty-nine subjects who had had similar diagnoses (operated on during the same eight months) who did not receive ketorolac (groups 1 and 2). All subjects received narcotics (intravenously) when complaining of pain. Variables recorded were type and duration of procedure, patient age, gender, post anesthesia recovery time, unscheduled admissions, ketorolac dose, narcotic requirements and doses, and nausea and/or vomiting. Data for each of the two groups were compared by Wilcoxon signed-rank test. Groups 1 and 2 did not differ in type or duration of surgery, patient age or gender. Procedures ranged from dilatation and curettage to major spinal surgeries. Post anesthesia recovery unit times, narcotic dosages and nausea and/or vomiting were not different between group 1 and 2. The timing of administration for the ketorolac may be a reason for these results; it may be beneficial if administered intraoperatively, or intravenously (when FDA approved in the United States) during the postoperative period.

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)

Glycosylated haemoglobin in uraemia.

Glycosylated haemoglobin (GHb) was measured in 71 patients with stable chronic renal failure by the thiobarbituric acid (TBA) reaction and by agar gel electrophoresis. Nineteen patients were diabetic. Of the non-diabetics, 22 were treated conservatively (including 8 children), 15 by maintenance haemodialysis, and 15 by continuous ambulatory peritoneal dialysis. GHb measured by both methods correlated with postprandial blood glucose levels. There was a significant discrepancy between the two methods only in patients with serum urea concentrations greater than 30 mmol/l, mean +/- SD, (6.8 +/- 2.6% vs 8.2 +/- 2.5% for TBA and electrophoresis, respectively). This difference, delta GHb, correlated with serum urea, serum creatinine, and serum bicarbonate, but after logistic regression of results from all 71 patients only serum urea was associated with delta GHb. Lower haemoglobin and GHb and high fetal haemoglobin concentrations in the haemodialysis group suggested increased haemolysis in these patients. Measurement of GHb by the TBA method and by agar gel electrophoresis remain useful indicators of hyperglycaemia in patients with mild, stable chronic renal failure.

Thymine salvage, mitochondria, and the evolution of the herpesviruses.

The salvage of thymine is an apparently ubiquitous feature of free-living lifeforms as well as of mitochondria, chloroplasts and most of the large DNA viruses. Assumptions and data are described which explain the evolution of thymine salvage in prokaryotes, animal cells, and large DNA viruses, in terms of deoxythymidine kinase and its relationship to mitochondria. Specifically, it is suggested that regulation of deoxythymidine kinase (by end-product inhibition) has evolved as a means of assuring a constant supply of thymine compounds for the mitochondria and that the degree to which this regulation is present in the deoxythymidine kinases of the various herpesviruses correlates with the degree of dependence of their replicative cycle on the continued health of the mitochondria of their host cells.

Chlorinated pesticides and polychorinated biphenyls in marine species, Oregon/Washington Coast, 1972.

Concentrations of chlorinated pesticides and polychlorinated biphenyls (PCB's) were determined in three offshore marine species from the Oregon/Washington coast: pink shrimp, euphausiids, and flatfish; five species of bivalve mollusks from five estuaries along the Oregon coast; several fish species from the Coos Bay and Columbia River estuaries; and a summer run of steelhead from the Rogue River. The compounds p,p'-DDE and PCB's were detected most frequently. Euphausiids and pink shrimp contained approximately 2 ppb (mug/kg) wet-weight DDE and 8 and 25 ppb PCB's, respectively. Offshore flatfish contained an average of 9 ppb DDE and 29 ppb PCB's. DDE residues in estuarine mollusks approximated 0.5 ppb. PCB levels were not detectable (greater than 3 ppb) except in collections from the mouth of the Columbia River where the levels averaged 400 ppb PCB's and 17 ppb DDT. Selected Columbia River where levels averaged 400 ppb PCB's and 17 ppb DDT. Selected Columbia River fish species contained 38 ppb DDE and 480 ppb PCB's; summer-run steel-head in the Rogue River contained 97 ppb DDE and 125 ppb PCB's. PCB chromatograms of most euphausiids closely resembled those of Aroclor 1254. Chromatograms of shrimp and flatfish indicated selective metabolism of two compounds in the Aroclor 1254 formulation. Biphenyls of higher chlorine content were also detected in the shrimp and flatfish.

Lipid composition of cyanidium.

The major lipids in Cyanidium caldarium Geitler are monogalactosyl diglyceride, digalactosyl diglyceride, plant sulfolipid, lecithin, phosphatidyl glycerol, phosphatidyl inositol, and phosphatidyl ethanolamine. Fatty acid composition varies appreciably among the lipids, but the major ones are palmitic acid, oleic acid, linoleic acid, and moderate amounts of stearic acid. Trace amounts of other acids in the C(14) to C(20) range were also present. Moderate amounts of linolenic acid were found in two strains, but not in a third. The proportion of saturated acid is relatively high in all lipids ranging from about a third in monogalactosyl diglyceride to three-fourths in sulfolipid. This may be a result of the high growth temperature. Lipases forming lysosulfolipid, and lysophosphatidyl glycerol are active in ruptured cells; galactolipid is degraded with loss of both acyl residues. Thus the lipid and fatty acid composition of Cyanidium more closely resembles that of green algae than that of the blue-green algae, although there are differences of possible phylogenetic interest.

Fatty acids in blue-green algae: possible relation to phylogenetic position.

Analyses of the lipids in five species of blue-green algae show that the fatty acids are largely the C(16) and C(18) acids. The only alga that could be grown heterotrophically, Chlorogloea, formed the triply unsaturated C(18) acid in the light but only the doubly unsaturated C(18) acid in the dark. Examination of these results and the results of others suggest that, except for one species, the more highly unsaturated acids are found in the morphologically more complex algae. The fatty acid compositions of blue-green algae are different from the fatty acid composition of the other prokaryotic organisms, the bacteria. It is speculated that the diversity of the patterns of fatty acid composition among the blue-green algae could be of phylogenetic significance.