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At least 55 records · Page 3Linked to original sources
PubMed2006

Effects of mid-season avermectin treatments on pyrethroid resistance in horn fly (Diptera: Muscidae) populations at three locations in Louisiana.

Between 1999 and 2002, the effect of mid-season doramectin treatments on the level of resistance in pyrethroid-resistant horn fly populations was examined at three separate Louisiana State University Agricultural Center research stations. The cattle were treated with pyrethroid ear tags in all years at all farms, and each farm received a mid-season doramectin treatment in 1 year. The number of weeks of control at Red River was 11 weeks higher in the year following the mid-season treatment of doramectin. At Macon Ridge, the number of weeks of control was 2 weeks higher in the year following the doramectin treatment. No change was observed at St. Joseph. The LC50s for fly populations tested at Macon Ridge and St. Joseph were found to increase for pyrethroids from the spring populations to the fall populations between 2000 and 2002. The LC50s for fly populations at Red River followed the same trends except in 2000, the year when the doramectin treatment was administered. Flies collected pre and post-treatment each year from St. Joseph and Red River were assayed for two alleles (kdr and skdr) associated with target site resistance to pyrethroids. Flies collected pretreatment at Macon Ridge in 1999 also were assayed for the kdr and skdr, and this population of flies had a frequency of 85.6% R-kdr alleles. At St. Joseph and Red River there was a general decline in the frequency of homozygous susceptible skdr (SS-skdr) and homozygous susceptible kdr (SS-kdr) individuals, as well as a general increase in homozygous resistant skdr (RR-skdr) and homozygous resistant kdr (RR-kdr) individuals, during the 4-year study. At both sites, the frequency of R-kdr alleles increased significantly in flies collected in the fall compared to flies collected in the spring with the exception of Red River in 2000, when dormacetin was applied. The frequency of the R-kdr alleles was significantly higher in flies collected in the fall compared to flies collected in the spring in the following year at both sites in two out of three comparisons. The frequency of R-skdr alleles was significantly lower in fly populations tested in the spring compared to fly populations tested in the fall at both farms in years when doramectin was not applied but there were no differences in the years when doramectin was applied. The frequency of R-skdr alleles was significantly higher in fly populations tested in the fall compared to in the spring the following year during all three comparisons at Red River and in one of three comparisons at St. Joseph.

Alleles↗
PubMed2001

Monitoring butocarboxim resistance of the woolly whitefly (Homoptera: Aleyrodidae) in citrus from Valencia, Spain.

Glass vials coated internally with an insecticide were used as a resistance monitoring technique for testing field populations of the woolly whitefly, Aleurothrixus floccosus (Maskell), collected from citrus. The distribution of resistance to the insecticide butocarboxim in citrus orchards from Valencia (Spain) during 1993 and 1994 was determined by means of this technique. Adults resting on citrus shoots were captured with a portable vacuum cleaner and introduced into the vials. The technique provides control mortality of <25% when assessed 7 h after the insects are captured. In 21 populations tested, LC50s ranged from 1.8 to 42.3 mg/ml. This represents resistance ratios >20-fold among populations. Lower slopes of the concentration-mortality line were found in whitefly populations that exhibited a low level of the LC50. Resistance was widespread in the Valencia areabut spatially irregular, with nearby orchards occasionally showing wide differences in resistance levels. The levels of resistance to butocarboxim obtained with this technique closely matched the field efficacy of the insecticide. This residue bioassay provides a convenient and rapid method to monitor insecticide resistance in A. floccosus populations.

Aldicarb↗
PubMed2002

Identifying older diabetic patients at risk of poor glycemic control.

BACKGROUND: Optimal glycemic control prevents the onset of diabetes complications. Identifying diabetic patients at risk of poor glycemic control could help promoting dedicated interventions. The purpose of this study was to identify predictors of poor short-term and long-term glycemic control in older diabetic in-patients. METHODS: A total of 1354 older diabetic in-patients consecutively enrolled in a multicenter study formed the training population (retrospective arm); 264 patients consecutively admitted to a ward of general medicine formed the testing population (prospective arm). Glycated hemoglobin (HbA1c) was measured on admission and one year after the discharge in the testing population. Independent correlates of a discharge glycemia > or = 140 mg/dl in the training population were assessed by logistic regression analysis and a clinical prediction rule was developed. The ability of the prediction rule and that of admission HbA1c to predict discharge glycemia > or = 140 mg/dl and HbA1c > 7% one year after discharge was assessed in the testing population. RESULTS: Selected admission variables (diastolic arterial pressure < 80 mmHg, glycemia = 143-218 mg/dl, glycemia > 218 mg/dl, history of insulinic or combined hypoglycemic therapy, Charlson's index > 2) were combined to obtain a score predicting a discharge fasting glycemia > or = 140 mg/dl in the training population. A modified score was obtained by adding 1 if admission HbA1c exceeded 7.8%. The modified score was the best predictor of both discharge glycemia > or = 140 mg/dl (sensitivity = 79%, specificity = 63%) and 1 year HbA1c > 7% (sensitivity = 72%, specificity = 71%) in the testing population. CONCLUSION: A simple clinical prediction rule might help identify older diabetic in-patients at risk of both short and long term poor glycemic control.

Journal Article↗
PubMed1997

[Statistic tests concerning population mortality indicators].

The objective of this note is to present simple statistical tests applied to common comparison problems met in descriptive studies in the general population. These tests apply to classical mortality indicators: crude and specific death rates, standardized rates (direct and indirect methods). The tests are based on the convergence of the Poisson distribution towards the normal distribution. For each type of comparison, confidence intervals are also provided.

Adult↗
PubMed1988

Observations on the contributions of environmental restraints and innate stem cell ability to hematopoietic regeneration.

A competitive repopulation assay utilizing chromosome markers was used to assay the reconstituting potential of hematopoietic populations. The test populations consisted of tibial murine marrow locally irradiated with doses ranging from 1.5 Gy to 8.5 Gy and of marrow generated from either murine splenic or marrow stem cells. The purpose of this assay was to assess the innate proliferative potential and microenvironmental influences on the ability to repopulate. Regardless of origin, spleen repopulating ability consistently agreed with spleen colony-forming unit (CFU-s) content. Doses of radiation from 5 Gy to 8.5 Gy diminished, by a factor of 2, the ability to repopulate marrow despite maintenance of CFU-s levels. Marrow generated from splenic stem cells had one-fifth the repopulating ability of marrow derived from marrow stem cells, even though CFU-s levels were equivalent. The results imply that the splenic environment can only maintain stem cells at the level of the CFU-s, even if the stem cells were originally of higher quality, and that their original potential cannot be regained in a marrow environment. Nevertheless, the marrow can maintain more primitive stem cells, but this reserve is drained to support CFU-s levels.

Animals↗
PubMed1979

Seasonal variation in work performance and heart rate response to exercise. A study of 1,835 middle-aged men.

A near maximal bicycle exercise test in 1,835 presumably healthy Norwegian men indicated a seasonal variation in physical fitness. Thus, the total amount of work performed was significantly higher, and the work pulse on equivalent loads significantly lower during the summer than during the autumn. Although the differences were small, they may invalidate comparisons made between exercise tests in populations tested at different seasons of the year. In particular, there was a considerable and sudden change in the above mentioned parameters from June--August to September--October.

Adult↗
PubMed2001

Overestimated frequency of a possible emphysema-susceptibility allele when microsomal epoxide hydrolase is genotyped by the conventional polymerase chain reaction-based method.

A recent association study suggested that the His113 variant of microsomal epoxide hydrolase (mEPHX) may confer a risk for development of emphysema, presumably by increasing susceptibility to smoking injury. Before considering a possible role of this enzyme in pulmonary disease, we attempted to characterize the genetic polymorphism further. The Tyr/His113 polymorphism within exon 3 of mEPHX was initially examined in 62 healthy individuals by conventional methods involving polymerase chain reaction (PCR)-based determination of a restriction fragment length polymorphism (RFLP). Genomic nucleotide sequences, including the polymorphic site and the downstream primer sequence, were further analyzed in 95 unrelated, healthy Japanese volunteers by single-stranded conformation polymorphism (SSCP) analysis and direct sequencing. Genotyping by the first method (PCR-RFLP) revealed that the allelic distribution in our test population apparently deviated from Hardy-Weinberg equilibrium. Sequence analysis showed that a synonymous nucleotide substitution, AAG to AAA (Lys119), was located just within the published primer site. The AAA at codon 119 was present only in alleles with Tyr113, and its frequency reached 0.31 in our panel of 190 Japanese alleles. This substitution potentially hampered PCR amplification because of the nucleotide mismatch, with the result that the frequency of the Tyr113 variation was underestimated. The frequency of His113, a possible emphysema susceptibility allele of the mEPHX gene, was thus overestimated when human DNA samples were genotyped in the conventional way. Depending on the population(s) tested, this anomaly could represent a pitfall for PCR-based association studies.

Alleles↗
PubMed1996

Validation of the combined olfactory test.

A new test of olfactory function, the combined olfactory test, has been designed to assess odours easily recognizable by the test population. The test consists of an odour recognition test of nine odours, where an odour in a bottle is chosen from a list of four possible odours in a forced choice manner. This is followed by a threshold test using a series of three-fold dilutions of 1-butanol. The mean of the two scores is the combined olfactory score. The test was subjected to a validation study. It was performed on 133 participants with a normal sense of smell and a normal rhinological examination and on 94 participants who said that they did not have a sense of smell. There was a highly significant difference between the combined olfactory score in the normal and 'anosmic' groups (P < 0.001). This significant difference was the same between the two groups for the threshold and odour recognition arms of the test. There was a highly significant difference (P < 0.001) between the two subgroups of 'completely anosmic' and 'almost anosmic' participants, indicating that the test could grade the degree of olfactory dysfunction.

Adult↗
PubMed1993

Changes in malathion and pyrethroid resistance after cypermethrin selection of Culex quinquefasciatus field populations of Cuba.

Use of the organophosphorus insecticide malathion for mosquito control in Cuba, for 7 years up to 1986, selected elevated non-specific esterase and altered acetylcholinesterase (AChE) resistance mechanisms in Culex quinquefasciatus. In central Havana space-spraying of malathion was replaced by the pyrethroid cypermethrin in 1987: alternate cycles of malathion and cypermethrin were applied in some of the more rural areas of Havana district during 1987-91. Consequently, populations of Cx quinquefasciatus in the central area of Havana developed resistance to cypermethrin, but there is no evidence of pyrethroid resistance in the outlying areas. Malathion resistance levels declined significantly after 1986, measured both by bioassay and the frequency of the elevated esterase resistance mechanism, and then stabilized with no measurable decline during 1990 in any of the populations tested. These populations had less than 10% frequency of susceptible homozygotes for both the esterase and AChE resistance mechanisms, indicating that organophosphate resistance is still prevalent in Cuban Cx quinquefasciatus. These two mechanisms appear to be in linkage equilibrium, suggesting that current selection for double resistance is not strong. In the central Havana region, pirimiphos-methyl, an organophosphorus insecticide unaffected by the two common malathion resistance mechanisms, is now being used in a resistance management strategy designed to avoid pyrethroid resistance spreading.

Animals↗
PubMed2002

[The ThinPrep Pap test in population screening].

The ThinPrep technique has been applied to Pap tests in a population screening program in Imola, Italy. A significative decrease in the number of inadequate tests has been observed, while the distribution of the Bethesda diagnostic categories was not different in comparison to the previous year, when conventional Pap tests were used with the adoption of the ThinPrep technique, the productivity of the screening program increased without any need to modify the screening protocol.

Adult↗
PubMed2001

Insecticide-induced behavioral responses of Anopheles minimus, a malaria vector in Thailand.

This study was designed to determine the behavioral responses of 2 test populations of Anopheles minimus females to DDT at 2 g/m2, deltamethrin at 0.0625 g/m2, and lambdacyhalothrin at 0.0369 g/m2 using an improved excito-repellency escape chamber. One test population was colonized in 1993 and referred to as a young colony. The 2nd field test population was collected from Ta-Soa County, Tri-Yok District, Kanchanaburi Province. in western Thailand and referred to as a wild population. Results showed that females of both young and wild test populations rapidly escaped from direct contact with DDT, deltamethrin, and lambdacyhalothrin. Lambdacyhalothrin exhibited the strongest irritant effect on female mosquitoes, followed by DDT and deltamethrin. Fewer females escaped from test chambers without direct contact with treated surfaces but the response was significantly different from that of the controls (P < 0.05). The noncontact response is indicative of a noncontact repellent action. Both contact irritancy and noncontact repellency are involved in An. minimus escape responses. Experimental hut studies that include monitoring of house-entering populations of An. minimus are needed for a meaningful assessment of noncontact repellent actions.

Animals↗
PubMed2002

Determining the sample size for co-dominant molecular marker-assisted linkage detection for a monogenic qualitative trait by controlling the type-I and type-II errors in a segregating F2 population.

Tests for linkage are usually performed using the lod score method. A critical question in linkage analyses is the choice of sample size. The appropriate sample size depends on the desired type-I error and power of the test. This paper investigates the exact type-I error and power of the lod score method in a segregating F(2) population with co-dominant markers and a qualitative monogenic dominant-recessive trait. For illustration, a disease-resistance trait is considered, where the susceptible allele is recessive. A procedure is suggested for finding the appropriate sample size. It is shown that recessive plants have about twice the information content of dominant plants, so the former should be preferred for linkage detection. In some cases the exact alpha-values for a given nominal alpha may be rather small due to the discrete nature of the sampling distribution in small samples. We show that a gain in power is possible by using exact methods.

Crosses, Genetic↗
PubMed1994

HIV-1 antibody positive hepatitis B surface antigen serum in a dental school patient population.

Testing for human immunodeficiency virus antibody (anti-HIV-1) in patients positive for hepatitis B surface antigen has never been performed in a dental school patient population. In this population there was a 2.8% positive reactivity for HIV-1 antibodies in subjects who were also positive for hepatitis B surface antigen. An enzyme-linked immunoassay with a repeat test and confirmation with a Western blot technique were used.

Blotting, Western↗
PubMed2006

Development of a smell identification test using a novel stick-type odor presentation kit.

The odor identification is strongly influenced by the social and cultural factors; therefore, the odorants used in a smell identification test should be familiar to the test population. In addition, the device used in the test is desired to be simply handled and retain odor quality over time. We developed a novel stick-type odor presentation kit that consists of microcapsules of odorant incorporated into stable cream and the smell identification test using it. Thirteen odorants were selected to be familiar to the test population. In the test, we used two identification methods: one was a modified forced-choice paradigm with "detectable but not recognizable" and "no smell detected" added as choices and the other was a two-step identification paradigm where the participant first selected one of eight odor categories and then chose the specific odor name from the selected category. We verified the performance of the odor stick and the test by stability, using a test-retest paradigm, comparing this test with another smell test, and testing Japanese people from a range of age groups. We conclude that this kit is a useful odor presentation device, and the test using it works effectively as a smell identification test.

Adult↗
PubMed2005

Involvement of a sodium channel mutation in pyrethroid resistance in Cydia pomonella L, and development of a diagnostic test.

Populations of the codling moth, Cydia pomonella L (Lepidoptera, Tortricidae) have developed resistance to several classes of insecticide such as benzoylureas, juvenile hormone analogues, ecdysone agonists and pyrethroids, but the corresponding resistance mechanisms have not been extensively studied. Knockdown resistance (kdr) to pyrethroid insecticides has been associated with point mutations in the para sodium channel gene in a great variety of insect pest species. We have studied two susceptible strains (S and Sv) and two resistant strains (Rt and Rv) of C pomonella that exhibited 4- and 80-fold resistance ratios to deltamethrin, respectively. The region of the voltage-dependent sodium channel gene which includes the position where kdr and super-kdr mutations have been found in Musca domestica L was amplified. The kdr mutation, a leucine-to-phenylalanine replacement at position 1014, was found only in the Rv strain. In contrast, the super-kdr mutation, a methionine-to-threonine replacement at position 918, was not detected in any C pomonella strain. These data allowed us to develop a PCR-based diagnostic test (PASA) to monitor the frequency of the kdr mutation in natural populations of C pomonella in order to define appropriate insecticide treatments in orchards.

Amino Acid Sequence↗
PubMed1979

Limitations of psychological tests in a dialysis population.

Psychological tests are being used increasingly in dialysis populations, both for psychosomatic research and for clinical evaluations, warranting careful examination of their uses and limitations. Characteristics associated with dialysis populations can limit the validity of many psychological tests which are useful in other populations. These characteristics include such factors as the great biological heterogeneity of dialysis patients, their uniquely dependent relationship to treating staff, and their tendency to respond with socially desirable answers. There is a need to develop psychological tests that are specific for dialysis populations and take into account social desirability response bias. At present, the limitations of psychological tests in a dialysis population are substantial.

Attitude↗
PubMed1984

Duffy (white) genes in a black Baltimore population.

Testing of 722 black hospital patients in Baltimore for the Duffy antigens found in whites demonstrated that 36.28 percent of the patients possessed these blood proteins. This group is the largest cluster of black individuals so examined in the United States. The results may provide a genetic benchmark for the Baltimore black population and offer a comparison with blacks in other areas.

Adolescent↗
PubMedDate not supplied

Cost-effectiveness of cardiac troponin I in a systematic chest pain evaluation protocol: use of cardiac troponin I lowers length of stay for low-risk cardiac patients.

We evaluated several measures of clinical and fiscal interest to assess the effect of adding an automated cardiac troponin I (c-TnI) assay to our current cardiac panel, which consists of creatine kinase MB (CK-MB), myoglobin, total CK activity, and a calculated CK-MB relative index. Samples were collected on admission and at 3, 6, and 8 hours after admission as part of our diagnostic protocol. Our study was designed to collect data on a control group of patients, implement a change (i.e., c-TnI testing), and then measure the effect of the change on a test population having otherwise equivalent diagnostic and therapeutic pathways. We assessed differences in patient hospital and cardiac care unit length of stay (LOS), time to cardiac catheterization, and hospital and laboratory charges and costs. We found that adding c-TnI to our testing regimen decreased LOS for the large test population. Within this large test population, patients classified as low risk for acute myocardial infarction experienced statistically and clinically significant shorter LOS and lower total and variable hospital costs; for patients with unstable angina, there was an increase (though not statistically significant) in laboratory costs.

Adult↗