Biomedical subjects

T A Long

Publications and source records attributed to T A Long.

17 recordsLinked to original sources

PubMed1998

Intragenic recombination and diversifying selection contribute to the evolution of downy mildew resistance at the RPP8 locus of Arabidopsis.

Pathogen resistance (R) genes of the NBS-LRR class (for nucleotide binding site and leucine-rich repeat) are found in many plant species and confer resistance to a diverse spectrum of pathogens. Little is known about the mechanisms that drive NBS-LRR gene evolution in the host-pathogen arms race. We cloned the RPP8 gene (for resistance to Peronospora parasitica) and compared the structure of alleles at this locus in resistant Landsberg erecta (Ler-0) and susceptible Columbia (Col-0) accessions. RPP8-Ler encodes an NBS-LRR protein with a putative N-terminal leucine zipper and is more closely related to previously cloned R genes that confer resistance to bacterial pathogens than it is to other known RPP genes. The RPP8 haplotype in Ler-0 contains the functional RPP8-Ler gene and a nonfunctional homolog, RPH8A. In contrast, the rpp8 locus in Col-0 contains a single chimeric gene, which was likely derived from unequal crossing over between RPP8-Ler and RPH8A ancestors within a Ler-like haplotype. Sequence divergence among RPP8 family members has been accelerated by positive selection on the putative ligand binding region in the LRRs. These observations indicate that NBS-LRR molecular evolution is driven by the same mechanisms that promote rapid sequence diversification among other genes involved in non-self-recognition.

Alleles↗

PubMed1996

Alcohol intake in high alcohol drinking (HAD) rats is suppressed by FG5865, a novel 5-HT1A agonist/5-HT2 antagonist.

Both the 5-HT2 antagonist, FG5606 (amperozide), and the mixed 5-HT1 agonist/5-HT2 antagonist, FG5893, attenuate significantly the volitional intake of alcohol in the cyanamide treated rat. The purpose of the present study was to investigate the effect on alcohol drinking in the selectively bred, high alcohol drinking (HAD) rat of a new and novel 5-HT1A agonist/5-HT2 antagonist, FG5865 (2-[4-[4,4-bis(4-fluorophenyl)butyl]-1-piperazinyl]-3-pyridinecarboxy lic acid methyl ester), which shares pharmacological properties with FG5893. Initially, a standard three bottle preference test for water vs. 3% to 30% alcohol solutions was given over 11 days to determine the maximally preferred concentration for each animal. Then water and this solution, which ranged between 9% and 20% with an overall mean absolute intake of 6.3 +/- 0.5 g/kg per day, was offered over three consecutive 4-day test sequences: (1) predrug control; (2) SC injections b.i.d. of either 1.0 mg/kg or 2.5 mg/kg FG5865 or saline control vehicle; and (3) postdrug. Whereas saline failed to alter alcohol consumption of the HAD rats, FG5865 caused a significant dose dependent reduction by as much as 75% in the intakes of alcohol during its administration in terms of both g/kg (p < 0.01) and proportion of alcohol to total fluid intake (p < 0.01). During the administration of 2.5 mg/kg FG5865, alcohol drinking declined from 6.5 +/- 0.3 g/kg to as low as 2.3 +/- 0.2 g/kg per day. Neither the body weight of the HAD animals nor their intake of food was affected by either dose of FG5865. These results uphold the concept that the 5-HT1A and 5-HT2 receptor subtypes in the brain play a part in the aberrant drinking of alcohol of the HAD rat. Because FG5865 influences the activity of serotonergic neurons in the mesolimbic system of the rat, it is envisaged that the drug suppresses alcohol drinking by way of its action on these neurons.

Alcohol Drinking↗

PubMed1996

Mycobacterial testing in clinical laboratories that participate in the College of American Pathologists Mycobacteriology Surveys. Changes in practices based on responses to 1992, 1993, and 1995 questionnaires.

OBJECTIVE: To determine whether the trend of increasing use of rapid methods of mycobacterial testing among participants in the College of American Pathologists (CAP) Mycobacteriology E Proficiency Testing Survey noted between 1992 and 1993 continued through 1995, and to collect information concerning mycobacterial staining and culture protocols from laboratories that do limited mycobacterial testing. METHODS: The 1993 CAP E Survey questionnaire addressing mycobacterial laboratory practices, test volumes, and rate of recovery of drug-resistant Mycobacterium tuberculosis was included with the CAP 1995 E-A Survey. A shortened list of these same questions, excluding those addressing mycobacterial identification and susceptibility test methods, was added to the CAP 1995 E1-A Survey, to which laboratories that do limited mycobacterial testing subscribe. RESULTS: A total of 802 and 1490 participants in the E and E1 surveys, respectively, returned responses to the CAP by the cutoff date for data analysis. For E Survey participants who answered questions concerning test methods in the years being compared, the percentage who used rapid techniques increased significantly over the study period. More participants used the fluorochrome stain (58% in 1992, 62% in 1993, and 72% in 1995), BACTEC TB plus a solid medium for culture (36% in 1992, 42% in 1993, and 50% in 1995), DNA probes for identification of M tuberculosis (68% in 1993, 79% in 1995), and BACTEC TB for susceptibility testing (65% in 1993, 71% in 1995). The percentages of E1 Survey participants who used a fluorochrome stain for detection of acid-fast bacilli and both a liquid and a solid medium for mycobacterial culture were lower than the percentages of E Survey participants who used these methods. Among participants who responded in all years being compared, the percentage processing respiratory specimens at least 7 times per week increased from 26% in 1992 to 30% in 1993 and 43% in 1995 (P < .001), and the percentages reporting an identification of M tuberculosis within 21 days and susceptibility test results within 28 days increased significantly over the study period (29% in 1992, 40% in 1993, and 56% in 1995 for identification; 13% in 1992, 19% in 1993, and 30% in 1995 for susceptibility testing). Turnaround times for E Survey participants were significantly shorter than those for E1 Survey participants. The number of specimens tested per month appeared to remain relatively stable between 1993 and 1995; however, the number of new patients with tuberculosis and the number of known tuberculosis patients with positive cultures declined significantly. CONCLUSIONS: The recent emphasis placed on utilization of rapid methods of mycobacterial testing appears to have influenced laboratories that subscribe to the CAP E Survey. Significantly more of these laboratories were following the Centers for Disease Control and Prevention's recommendations in 1995 than in 1993 and 1992. However, many laboratories that provide only limited mycobacterial testing still have not adopted the more rapid techniques. Because tuberculosis remains a public health problem, the efforts directed at its control must not wane if the recent downward trend in incidence is to be maintained.

Bacteriological Techniques↗

PubMed1993

Inventory management for cardiac catheterization labs: the Princeton-Baptist Medical Center experience.

Several issues must be considered for implementation in order to decrease inventories and make them more manageable. Physician consensus on products, strict vendor control by the department manager, setting and maintaining low par levels, inventorying stock daily, negotiating just-in-time deliveries, conservation-minded staff, and working in concert with central supply and materiel management personnel are steps that when employed correctly can lead to more manageable inventories in cardiac catheterization departments. If these steps are implemented, they will enhance the liquidity of the department and ultimately that of the medical center.

Alabama↗

PubMed1993

National pathology manpower survey of 1991. Projected needs in community hospitals and private laboratory practice.

The third survey of a representative group of pathologists in community practice confirms the prediction based on the 1987 and 1988 surveys that there would be a growing deficit in the number of pathologists in this practice setting. There is an increasing number of reported vacancies in pathology groups and a significant increment in the percentage of older pathologists, with 32% being older than 54 years of age in 1991, compared with 25% in 1987. Projections based on the plan of individual respondents to retire and the anticipated changes in practice groups suggest that there will continue to be more pathologists leaving practice than new pathologists entering the specialty.

Adult↗

PubMed1993

Physician goals and laboratory test turnaround times. A College of American Pathologists Q-Probes study of 2763 clinicians and 722 institutions.

Laboratory test turnaround times (TATs) for emergency department patients were studied in 722 institutions using Q-Probes, a quality improvement program of the College of American Pathologists. The medians of the TATs required by 2763 clinicians were 10 minutes for PO2, 20 minutes for hemoglobin, and 30 minutes for potassium and glucose measurements. Surgeons had the shortest TAT requirements for hemoglobin, potassium, and glucose measurements, whereas emergency department physicians had the shortest requirements for PO2. The measured TATs of most hemoglobin and potassium determinations did not meet clinician goals. In contrast to laboratorians, the majority of clinicians defined a TAT start time as test ordering, and a TAT ending time as result reporting. We recommend laboratorians and clinicians mutually agree on the definition of TAT, jointly develop timeliness goals, and together improve TAT performance to fulfill these goals.

Diagnostic Tests, Routine↗

PubMed1992

Emergency department stat test turnaround times. A College of American Pathologists' Q-Probes study for potassium and hemoglobin.

We report aggregate turnaround times (TATs) from phlebotomy to result reporting of emergency department patients' hemoglobin and potassium results for 722 subscribers to the College of American Pathologists Q-Probes program. Approximately 40,000 specimens were obtained for each analyte. Median interinstitutional TAT time of 25 minutes for hemoglobin and 36 minutes for potassium varied little by shift, weekdays, or weekends. The type of personnel collecting the specimen and the method of specimen transport were the most important factors affecting TATs. Specimen transit times accounted for approximately one third of the total TATs, but when couriers transported hemoglobin specimens, the median transit time was equivalent to the median intralaboratory test TAT. The influence of various measures used to improve test transit and TATs is presented.

Bloodletting↗

PubMed1991

Influence of laboratory test volume and geographic location on maternal alpha-fetoprotein results. Information from the College of American Pathologists Maternal alpha-fetoprotein Survey.

Using 1989 College of American Pathologists Maternal alpha-fetoprotein (AFP) Survey data, we found virtually no association between a laboratory's AFP test volume and the reliability of reported multiples of the median uncorrected for maternal weight, race, or diabetes. We also found no differences in AFP gestational age-specific medians across geographic regions of the United States. We did find that clinically important adjustments for maternal weight, race, and diabetes were made more frequently by laboratories with higher clinical AFP test volumes. Consequently, we believe that a minimum AFP test volume for satisfactory performance of AFP testing, as proposed by several professional organizations, cannot be justified on inability of laboratories with low AFP test volumes to quantify AFP in clinical specimens or calculated uncorrected multiples of the medians accurately. However, high-volume laboratories enhance clinical utility of the reported AFP results by making clinically important adjustments of their reported multiples of the medians, and they tend to provide more accurate clinical interpretations. Therefore, we recommend that efforts to improve the quality of AFP testing nationally should focus on improving the ability of laboratories to provide appropriate adjustments to and clinical interpretation of their AFP results, in addition to more traditional efforts directed toward quality control of the analytical aspects of the AFP assay.

Clinical Laboratory Techniques↗

PubMed1990

Two philosophers in search of a contradiction: a response to Singer and Kuhse.

Peter Singer and Helga Kuhse reject my claim that because their views on the mortality of infanticide are metaphysically incommensurate with those of Paul Ramsey they cannot refute his position. According to them, I have failed to see that Ramsey contradicts himself. Once this is seen, no further refutation is needed. I argue that there is no contradiction and offer further thoughts on the metaphysically incommensurate.

Ethical Analysis↗

PubMed1990

Correlates to radiology managers' job satisfaction.

The satisfaction derived from one's job has implications for both employee and organization. This study examined the effect of five facets of the job on the overall job satisfaction of radiology department managers. Results indicated that work (tasks) performed and supervision received significantly contributed to managers' perception of their overall job satisfaction. The implications of these findings are discussed as they relate to the employee and organization.

Adult↗

PubMed1988

Infanticide for handicapped infants: sometimes it's a metaphysical dispute.

Since 1973 the practice of infanticide for some severely handicapped newborns has been receiving more open discussion and defence in the literature on medical ethics. A recent and important argument for the permissibility of infanticide relies crucially on a particular concept of personhood that excludes the theological. This paper attempts to show that the dispute between the proponents of infanticide and their religious opponents cannot be resolved because one side's perspective on the infant is shaped by a metaphysics that is emphatically rejected by the other. In such a situation philosophical argument is powerless to bring about a resolution because there can be no refutation of one side by the other.

Persons with Disabilities↗

PubMed1986