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Biomedical subjects

R Klemm

Publications and source records attributed to R Klemm.

8 recordsLinked to original sources
PubMed2000

The effect of imputation of exposure estimates on the association between fine particulate matter and mortality.

PURPOSE: The Harvard Six Cities Study (HSCS) found a small but significant association between daily PM2.5 and daily mortality count. The HSCS findings have been used as the basis for new EPA regulations, requiring lower levels of PM2.5. We feel that there are unresolved issues regarding the HSCS that should be fully evaluated prior to its findings being used as the basis of new regulation, including how the extent and method of imputing exposure data affect the association with daily mortality counts.METHODS: We examined the association between PM2.5 levels and daily mortality count, comparing the results from the HSCS methods with results based on an alternate imputation method, and with non-missing data.RESULTS: Overall, approximately 30% of the data points used in the HSCS were imputed. The method of imputation affected the association between particulate matter and mortality to a substantial degree in most of the cities. When the model using the HSCS method was compared to the model using the alternate method, in two areas the coefficients decreased substantially and lost significance. In two areas they changed little; in one area it rose substantially and became significant; and in one area it declined substantially but remained significant. When compared to the model based on the non-missing data, somewhat different patterns were observed. In both comparisons there were some large changes in the magnitude of the effect, but these were not consistent with the model used.CONCLUSIONS: We are concerned about the degree of data imputation and the effect that the method of imputation has on the association between particulate matter levels and mortality. In the case of the HSCS it appears that the imputed data are more strongly associated with the outcome than other methods of imputation and than the non-missing data. The reasons for these observations are not readily apparent, but the differences in effect should be explored and explained.

Journal Article↗
PubMed1999

Research and quality control in natural family planning with relational database systems.

Research and quality control in natural family planning (NFP) is based on continuous data collection in prospective studies. The quality of the data is determined by the reliability of collection, input, management, and retrieval. During a period of ten years, different relational databases were programmed to manage the large number of very different data in NFP studies. Recently, all experience with different database systems has been summarized by writing and testing a completely new data management system based on MS Access 97: NFPDAT 1.0. This new software is used for data collection, evaluation and administration in NFP Study Groups. Over 200 internal formulae guarantee maximum data consistency while 30,000 cycles from 1477 patients were stored. Easy data evaluation for research and administration is possible with the help of a new report generator even without prior knowledge of SQL (System Query Language) or Visual Basic for MS Access 97. Using this method, interim results for research and quality control can be obtained at any time. NFPDAT can be used by all Natural Family Planning Study Groups using the symptothermal method for research and administration. With the help of NFPDAT, various prospective studies of Natural Family Planning were conducted.

Austria↗
PubMed1998

Retrospective clinical trial of contraceptive effectiveness of the electronic fertility indicator Ladycomp/Babycomp.

The Babycomp/Ladycomp (Valley Electronics Ltd., Eschenlohe, Germany) is an electronic device that combines the temperature method and calendar method for planning and preventing pregnancy by identifying the fertile and infertile phases of the menstrual cycle. In a retrospective clinical trial, the system was tested as a contraceptive aid. A total of 648 women from Germany and Switzerland have participated: 597 women with 10,275 months of use used the device for contraception. Thirty-three unplanned pregnancies were identified, giving a total pregnancy rate of 3.8 use effectiveness according to the Pearl Index. Six method-related pregnancies occurred, producing a method Pearl Index of 0.7. Calculating the cumulative pregnancy rates by life-table analysis, it was found that, after about one year of exposure, the probability of an unintended pregnancy was 5.3% (0.053), after 2 years it was 6.8% (0.068) and after about 3 years of exposure it was 8.2% (0.082). The mean length of the identified fertile period was 14.3 days with a standard deviation of 4.6 days in all cycles reported. The acceptance of the device by the woman and her partner was good. In fact, 21 of the 33 women who became pregnant would still recommend the device for further use (63.6%).

Actuarial Analysis↗
PubMed1995

p53 transcriptional activation mediated by coactivators TAFII40 and TAFII60.

The tumor suppressor protein p53 is a transcriptional regulator that enhances the expression of proteins that control cellular proliferation. The multisubunit transcription factor IID (TFIID) is thought to be a primary target for site-specific activators of transcription. Here, a direct interaction between the activation domain of p53 and two subunits of the TFIID complex, TAFII40 and TAFII60, is reported. A double point mutation in the activation domain of p53 impaired the ability of this domain to activate transcription and, simultaneously, its ability to interact with both TAFII40 and TAFII60. Furthermore, a partial TFIID complex containing Drosophila TATA binding protein (dTBP), human TAFII250, dTAFII60, and dTAFII40 supported activation by a Gal4-p53 fusion protein in vitro, whereas TBP or a subcomplex lacking TAFII40 and TAFII60 did not. Together, these results suggest that TAFII40 and TAFII60 are important targets for transmitting activation signals between p53 and the initiation complex.

Amino Acid Sequence↗
PubMed1992

Paid and unpaid benefits. Strategies for nurse recruitment and retention.

One of the biggest problems facing hospital administrators is the recruitment and retention of nursing staff. The authors examine how a sampling of hospitals are meeting this challenge and describe important tangible and intangible benefits that can curb nursing turnover. This study defines ways to boost employee morale and cut administrative costs.

Humans↗
PubMed1991

Interrelationship between hypersensitivity to soybean proteins and growth performance in early-weaned pigs.

The objective of this growth trial was to determine the interrelationship between immunological criteria, gut morphology, and performance of starter pigs fed soybean proteins processed by different methods. One hundred twenty-five pigs were orally infused with 6 g/d of either dried skim milk, soybean meal (48% CP), soy protein concentrate, extruded soy protein concentrate, or experimental soy protein concentrate from 7 to 11 d of age and then fed a diet containing the same protein sources from weaning (d 21) to 35 d of age. All pigs were fed a corn-soybean meal diet containing 10% dried whey, 1.25% lysine, and 3% soybean oil for the remaining 21 d of the experiment. Xylose absorption and anti-soy immunoglobulin G (IgG) titers were measured on d 6 postweaning, and skin-fold thickness after intradermal injection of protein extracts was measured on d 7 postweaning. A total of 25 pigs (five pigs/treatment) was euthanatized on d 7 postweaning. Villus height and crypt depth from duodenum samples were measured. These measurements were obtained to elucidate a relationship between the hypersensitivity responses to soybean products and growth performance of baby pigs. Pigs fed diets containing soybean meal had a lower (P less than .05) rate of gain (d 0 to 14) and villus height, higher (P less than .01) serum anti-soy IgG titers, and increased skin-fold thickness (d 6 and 7 postweaning) after intradermal injection compared with those fed dried skim milk. Pigs fed other soy proteins also had lower ADG from d 0 to 14 postweaning; however, pigs fed moist extruded soy protein concentrate tended (P less than .09) to have higher ADG and improved feed utilization when compared with pigs fed soybean meal (d 0 to 14).(ABSTRACT TRUNCATED AT 250 WORDS)

Animal Feed↗