bluuebunny/crossref_metadata_2025 huggingface dataset:
Aneuploidy and ageing: chromosome studies on a random sample of the population using G-banding
Authors: Galloway S.M. , Buckton K.E.
Published: May 2008

Chromosome analysis using G-banding was carried out on cells from 65 males and 102 females of all ages from a random sample of the population. The frequency of aneuploid cells showed a significant increase with age in both sexes, and in females the increase in hypodiploidy and hyperdiploidy was more marked than in males, and involved a high proportion of cells that had lost or gained an X chromosome, 45, X cells being much more common than 47, XXX cells. In females, the occurrence of a “fragment” of an X chromosome also correlated with increasing age, and this “fragment” appears to be an X chromosome that has simply divided prematurely at the centromere. The effects of time in culture and of repeating cultures of blood samples from the same individual on proportions of abnormal cells of various types were also investigated, and the results are discussed in the light of findings from several other “ageing surveys.”
Chromosome aberrations and unscheduled DNA synthesis in X- and UV-irradiated lymphocytes from a boy with Bloom’s syndrome and a man with xeroderma pigmentosum
Authors: Evans H.J. , Adams A.C. , Clarkson J.M. , German J.
Published: May 2008

Blood lymphocytes from a boy with Bloom’s syndrome and a man with a mild form of xeroderma pigmentosum were examined for their response to UV-irradiation, as measured by the levels of induced unscheduled DNA synthesis, and to X-irradiation, as measured by chromosome aberrations. Although the individual with Bloom’s syndrome showed facial skin sensitivity to sunlight, his lymphocytes showed a normal response in unscheduled DNA synthesis. In contrast, cells from the individual with xeroderma pigmentosum showed a 50 % reduction in the amount of unscheduled DNA synthesis following UV exposure. Cytogenetic studies on PHA-stimulated Bloom’s syndrome lymphocytes revealed a typical increase in the incidence of aberrations. Many of the Bloom’s cells showed breakages located at the centromere and equal, symmetrical chromatid interchanges involving homologous chromosomes; these aberrations were not produced in control cells cultured in serum from the Bloom’s syndrome patient. In contrast, the frequency of spontaneous aberration in xeroderma pigmentosum lymphocytes was similar to that in controls. G1 cells from both patients were exposed to a range of X-ray doses, and it was shown that neither cell type differed from controls in the incidence of induced chromosome-type aberrations. The significance of these findings is discussed.
A homologous tandem translocation [45,XX,–13,–13,+t(13;13)(q12;q34)]
Authors: Cohen M.M. , Rosen Y. , Gadoth N. , Tal A.
Published: May 2008

Chromosomal investigation of a young girl with mental and motor retardation and congenital anomalies revealed a translocation between both members of pair No. 13. Banding analysis showed that the translocation was “tandem,” leading to monosomy for segments in both the long and short arms of No. 13.
Meiotic analysis of a pericentric inversion, inv(7) (p22q32), in the father of a child with a duplication-deletion of chromosome 7
Authors: Winsor E.J.T. , Palmer C.G. , Ellis P.M. , Hunter J.L.P. , Ferguson-Smith M.A.
Published: May 2008

In a family in which a large pericentric inversion of chromosome 7 is segregating, two of the four progeny of inversion heterozygotes show severe psychomotor retardation and have the karyotype 46, XX, rec(7), dup q, inv(7)(p22q32), derived from crossing-over within the inversion. Meiotic analysis in one of the heterozygotes revealed no evidence of inversion loops in well-spread pachytene cells. In approximately 20 % of cells in diakinesis, the presumptive bivalent 7 had only one chiasma. Two alternatives to the reversed loop mode of meiotic pairing of inversions are proposed. Review of the literature supports the view that “small” pericentric inversions have a much better genetic prognosis than “large” pericentric inversions.
Structural chromosome abnormalities in Down syndrome: a study of two families
Authors: Jacobs P.A. , Mayer M. , Rudak E.
Published: May 2008

Two families were ascertained through a proband with Down syndrome and a structural rearrangement involving two chromosomes 21. It is suggested that in one patient the chromosome is an isochromosome formed by misdivision of the centromere of a maternal telocentric chromosome 21 and that in the other a Robertsonian translocation involving chromosome 21 was inherited from the mother, who is a 46, XX/46, XX,–21,+t(21q21q) mosaic. The origin of the mosaicism is discussed and considered to be likely to be the result of breakage and reunion at the chromatid, rather than the chromosome, level.
The origin of the extra chromosome 21 in Down syndrome
Authors: Hansson A. , Mikkelsen M.
Published: May 2008

Studies of fluorescence and other chromosomal variants were informative in 26 out of 72 families. Maternal nondisjunction was found in 19 and paternal in 7 cases. Satellite association studies of these parents and 94 controls from the same age group showed a highly significant increase in the satellite association index (AI) for chromosome 21 in the parents where the nondisjunctional event had taken place. The AI was also higher for chromosome 14. In addition, the parents who produced the normal gametes had significantly higher AI’s for some acrocentrics than the controls. Exogeneous factors increasing satellite association cannot be ruled out. The number of 21–21 associations was significantly increased in the parents with nondisjunction in meiosis I. The results indicate that satellite association may play a role in the etiology of Down syndrome.
The meiotic behavior of triploidy in a human 69,XXX fetus
Authors: Luciani J.M. , Devictor M. , Boué J. , Freund M. , Stahl A.
Published: May 2008

Meiotic studies were made on the fetal ovaries of a triploid fetus, 69, XXX. The association modalities of the three chromosomes in human triploidy are the same as those described in several plant species; i.e., trivalents, bivalents and univalents can be found in the same nucleus. In most cases of trivalent configuration, the association occurs between pairs.
Crossover suppression in mice heterozygous for tobacco mouse metacentrics
Authors: Cattanach B.M.
Published: May 2008

Evidence is presented to show that crossing-over between the house mouse acro-centric chromosomes 1, 4, and 5 and the homologous chromosomes of the tobacco mouse Robertsonian translocations, Rb(1.3)lBnr, Rb(4.6)2Bnr, and Rb(5.15)3Bnr, is suppressed in the proximal regions. The data on chromosomes 6 and 9 of Rb2(4.6)Bnr and Rb6(9.14)Bnr, respectively, were ambiguous, but no evidence of crossover suppression was found with the other arm of Rb3Bnr (chromosome 15), nor was any suppression detected with the other tobacco mouse metacentrics when tested with chromosomes 8, 11, 12, 13, 14, and 17. Equivalent tests with the two Robertsonian translocations of house mouse origin, Rb(6.15)lAld and Rb(9.19)163H, also failed to demonstrate crossover suppression. Consideration of the combined genetic and cytogenetic maps of the chromosomes investigated showed that where crossover suppression was found, it could be detected with gene markers located at least halfway down the lengths of the chromosomes. Moreover, probably all the tests employed markers that were located proximally enough to detect crossover suppression of this magnitude. It is concluded that crossover suppression is not typical of all Robertsonian translocations and that the suppression found with RblBnr, Rb2Bnr, and Rb3Bnr could be attributed to minor structural or genie differences between the tobacco mouse metacentrics and house mouse acrocentrics within the proximal regions of only those chromosomes affected. These findings clearly demonstrate that there is no direct relationship between crossover suppression and nondisjunction. Although both phenomena may be attributed to differences between the metacentric and acrocentric chromosomes of the two species, the differences responsible for each type of event need not be the same. There was a deficiency of progeny carrying a metacentric in many of the crosses, and this was more evident when the heterozygous parent was a female. There was no indication of any relationship between this event and either non-disjunction or crossover suppression.
Chromosome banding studies of the Equidae
Authors: Ryder O.A. , Epel N.C. , Benirschke K.
Published: May 2008

The chromosome banding patterns of all seven extant species of the horse family, Equidae, are presented. This mammalian family is composed of a single genus, Equus, notable for its rapid karyotypic evolution. Comparison of G-banded karyo-types has allowed the identification of similar elements in the various species. Chromosome fusions and inversions have been identified, but many rearrangements remain unidentified. In addition to conservation in G-banding patterns of the equine X chromosomes, another chromosome with a conserved G-banding pattern has been identified. Additionally, several examples of chromosomes with a unique G-banding pattern present in two or more species are described. The G-banding pattern of the chromosomes of E. zebra hartmannae (2n = 32) is unique and shows little resemblance to that of other Equidae. The pattern of constitutive heterochromatin, as determined by C-banding, shows alteration with the reduction in diploid chromosome number within the Equidae. Species with the highest diploid chromosome numbers display mainly centromeric C-bands, whereas species with lower diploid chromosome numbers display fewer C-banded chromosomes, and frequently when C-bands are present, they are not centromeric in location. The first description and cytogenetic study of a hybrid from the cross E. grevyi X E. burchelli antiquorum is presented showing extensive homologies between the G-banded chromosomes of these two species.
Studies on the function of H-Y antigen: dissociation and reorganization experiments on rat gonadal tissue
Authors: Zenzes M.T. , Wolf U. , Günther E. , Engel W.
Published: May 2008

On circumstantial evidence, H-Y antigen is assumed to be responsible for the differentiation of the undetermined gonadal anlage into a testis. A direct approach to test the function of H-Y antigen is provided by Moscona-type experiments. Applying a modified technique of in vitro reassociation of cell suspensions, we obtained the following results: (1) dissociated newborn rat gonads, both testis and ovary, reorganize into histotypic structures; (2) under exposure to anti-H-Y anti-serum, testicular cells reassociate into ovarian follicular-like organization; (3) anti-H-l antiserum by itself does not prevent the testicular cells from forming tubular structures. It is concluded that H-Y antigen acts as a differentiation antigen preferably or exclusively on the cell elements participating in the formation of the seminiferous cords.
Human tumor and rodent-human hybrid cells with an increased number of active human NORs
Authors: Miller D.A. , Dev V.G. , Tantravahi R. , Croce C.M. , Miller O.J.
Published: May 2008

A human fibrosarcoma line, HT1080–6TG, with a near diploid number of chromosomes, has an average of 7.3 chromosomes with an Ag-stained nucleolus organizer region (NOR). Cells of this line with an increased number of chromosomes have an increased number of Ag-stained NORs. This cell line has been used as the human parent in constructing mouse-human and rat-human hybrids that segregate rodent chromosomes. The hybrid cell lines, which have 100 or more chromosomes per cell, show a proportionate increase in the number of Ag-stained NORs (means, 11.4–16.8). The frequency of association of acrocentric chromosomes increases in a similar fashion. There is no evidence of inactivation of human NORs in these cells.
Assignment of the gene for adenosine kinase to chromosome 14 in Mus musculus by somatic cell hybridization
Authors: Leinwand L. , Fournier R.E.K. , Nichols E.A. , Ruddle F.H.
Published: May 2008

Evidence is presented for the assignment of the gene for adenosine kinase to Mus musculus chromosome 14 by synteny testing and karyotypic analysis of mouse X Chinese hamster somatic cell hybrid clones. ADOK and two enzymes previously mapped to mouse chromosome 14, NP and ES-10, were expressed concordantly in 29 hybrid clones. Chromosome analysis confirmed this assignment. Syntenic evidence is also presented using several clones of a gene transfer system in which the gene for human HPRT had integrated into modified mouse chromosome 14’s.
Induced Robertsonian fusions and tandem translocations in mammalian cell cultures
Authors: Hsu T.C. , Pathak S. , Basen B.M. , Stark G.J.
Published: May 2008

Cultures of a cattle cell line and a Peromyscus eremicus cell line recovering from a pulse-treatment with mitomycin C, actinomycin D, 33258 Hoechst, and nitrosoguanidine exhibited translocations between chromosomes at the centromeric regions (Robertsonian fusions) as well as between centromere and telomere and between telomeres (tandem translocations). The frequency of Robertsonian fusions was found to be dose-dependent and duration-dependent with the mitomycin treatment. Biarmed chromosomes resulting from fusions may be monocentric or dicentric. Analyses of clones isolated from treated cells suggested that fused chromosomes may perpetuate in the cell populations.
Laboratory mice carrying three pairs of Robertsonian translocations: establishment of a strain and analysis of meiotic segregation
Authors: White B.J. , Crandall C. , Raveché E.S. , Tjio J.-H.
Published: May 2008

The evolution of a 2n = 34 combined Robertsonian translocation strain Rb(5.19)1Wh/(6.15)1Ald/(8.17)HEM is described. Homozygotes had three large ring translocation bivalents at M I and regular meiotic disjunction at M II. Male and female F1· heterozygotes had similar frequencies of abnormal meiotic disjunction at M II, but aneuploid embryos were more frequent in (F1♂ X NIH GP ♀) crosses (25.6%) than (F1 ♀ X GP ♂) crosses (13.5%) at 10 days’ gestation. It could not be determined whether this discrepancy was genetic in origin or due to limitations in the techniques of M II analysis. Rb(5.19), as well as Rb(6.15) or (8.17), contributed to the aneuploidy, although previous M II analysis of singly heterozygous Rb(5.19)/+ males demonstrated comparatively regular meiotic disjunction. Trisomic embryos were not detected beyond 10 days in five (F1 ♀ X GP ♂) crosses, suggesting that their survival in F1 females is limited. The ratios of the different types of balanced embryos from the (F1 X GP) crosses indicated random meiotic segregation of the three translocation chromosomes in triple heterozygotes. Analysis of complementary groups of balanced embryos from the same crosses also demonstrated lack of preferential segregation of the translocations; embryos with translocations and those with their corresponding homologous acrocentrics were equally frequent. Triploid embryos (3.3 %) were also detected in (F1♂ X NIH GP ♀) crosses. The translocations and Y chromosome served as paternal markers, permitting its origin to be determined in two of three cases (dispermy). One growth-retarded triploid had a distinctive anomaly: failure of lens induction and lack of optic cup development. The combined strain provided a complex of markers for determining polyploidy mechanisms, as well as a common genetic background for comparing behavior of the three translocations at M I.
The use and limitations of chiasma scoring with reference to human genetic mapping
Authors: Hultén M. , Luciani J.M. , Kirton V. , Devictor-Vuillet M.
Published: May 2008

Human chiasma data are summarized, and some preliminary new observations in fetal oocytes are presented. Male chiasma data may give reliable estimates of genetic lengths, both for individual chromosome arms and for the total autosomal complement. Female data are as yet less accurate and give information according to chromosome group only. Movement of chiasmata before they can be reliably scored is unlikely. In both sexes, chiasmata are seen to be clustered along the length of the chromosomes, which may reflect crossingover interference and a tendency for crossingover to more often take place in certain chromosome segments; there are some indications of sex differences in these preferences.
Identification of the facultative heterochromatic X chromosome in females of 25 rodent species
Authors: Kanda N. , Yosida T.H.
Published: May 2008

Treatment of the chromosomes of 25 rodent species with a 50° C hypotonic solution and Giemsa staining permitted identification of the heterochromatic X chromosome in 24 species. With this technique, the facultative heterochromatic X chromosome or the facultative portion of large, composite-type X chromosomes is stained darker than the other chromosomes, allowing it to be distinguished from the homologous euchromatic X chromosome in female metaphase cells. Intense staining of the single X chromosome was not observed in male metaphase cells. It is suggested that this differential staining of one of the two X chromosomes might be due to qualitative differences in chromosomal proteins rather than to differences in the degree of chromosomal condensation or in DNA base sequence.
Nonhomologous associations of C-heterochromatin at human male meiotic prophase
Authors: Driscoll D.J. , Palmer C.G. , Melman A.
Published: May 2008

In human male meiotic prophase, nonhomologous pairings and connections between C-heterochromatic regions were demonstrated by C-banding and G-ll staining. Approximately 40% of the pachytene stages exhibited bivalent associations at regions of C-heterochromatin. Nonhomologous associations were seen between all possible morphological types of bivalents. Evidence is submitted suggesting that nonhomologous associations between regions of C-heterochromatin are a fairly common event in many organisms, including man, and the possible roles of this phenomenon in meiosis are discussed.
Induction of high frequencies of endoreduplication in mammalian cell cultures with 33258 Hoechst and rubidazone
Authors: Kusyk C.J. , Hsu T.C.
Published: May 2008

Cells of the mouse L strain and the Chinese hamster CHO line were treated with 33258 Hoechst, rubidazone, and a combination of these. Recovering cell populations following the drug removal exhibited a high frequency (20–50%) of metaphases with diplochromosomes (endoreduplication), especially in the combination treatment series (up to more than 70% in the L strain). Such a procedure should be useful in probing the mechanisms of the endoreduplication process.
A selective medium (GAMA) for the isolation of somatic cell hybrids from HPRT– and APRT– mutant cells
Authors: Liskay R.M. , Patterson D.
Published: May 2008

A medium is described which can be used for the selection of somatic cell hybrids between HPRT– and APRT– mutant cells. This medium, called GAMA, contains as its relevant constituents the following: the purines guanine and adenine and the purine biosynthetic pathway inhibitors mycophenolic adic, which blocks conversion of adenine ribonucleotides to guanine ribonucleotides, and azaserine, which blocks de novo purine synthesis.
Comparison of the karyotypes of four Cercopithecoidae: Papio papio, P. Anubis, Macaca mulatta, and M. fascicularis
Authors: Dutrillaux B. , Biemont M.C. , Viegas-Pequignot E. , Laurent C.
Published: May 2008

The karyotypes of two species of baboons, Papio papio and P. anubis, and of two species of Macaca, M. mulatta and M. fascicularis, are compared after the use of numerous banding techniques. No difference was detected between the karyotype of the two Papio species. However, a minor change in the T-staining of a short segment, probably heterochromatic, could be detected between the Papio species and M. mulatta. A paracentric inversion exists between these three and M. fascicularis. These karyotypes are briefly compared with those of the Pongidae and man. The value of the karyotypic criteria and of the methods used for taxonomy is discussed.
Distribution of spontaneous chromosome breaks in man
Authors: Mattei M.G. , Ayme S. , Mattei J.F. , Aurran Y. , Giraud F.
Published: May 2008

The distribution of break points in human chromosomes was analyzed in 15,754 metaphases from 1084 patients. A total of 1099 breaks were specifically localized to a chromosome band or region depicted in the Paris Conference (1971) report. The sites of the breaks were very different from the expected random distribution and showed distinct clustering of breaks in some regions. These observations underline the heterogeneity of chromosomal material and furnish comparative data for the study of cytotoxic agents and constitutional chromosomal fragility.
Do homologous chromosomes differ?
Authors: Moore II D.H. , Carrano A.V. , Mayall B.H.
Published: May 2008

This paper is concerned with the problem of deciding whether measurements from homologous chromosomes differ. First, a general mathematical model is proposed for studying the distribution of chromosome measurements. Next, log-likelihood ratios are used to test for correlation between homolog pairs and for differences between homolog means and variances. The tests are applied to measurements on 1946 pairs of chromosomes from 10 normal individuals. Test results are interpreted taking into account the large number (2025 total tests) required by the study. Our results demonstrate that, at the current level of resolution, most homologs do not show differences in DNA content. However, there is some evidence that several homolog pairs differ by small amounts of DNA (less than 0.2% of the autosomal genome). Power studies indicate that sample sizes of 20 to 30 measurements are required to detect differences of this size.
Micromethod for chromosome preparations from Chinese hamster lymphocytes
Authors: de Jong B. , Anders G.J.P.A. , Wierda J. , van der Meer I.H. , Zijlstra J.
Published: May 2008

Chromosome preparations from Chinese hamster lymphocytes were made by culturing for 2 to 6 days 50,000 to 800,000 lymphocytes in flat-bottomed Cooke microtiter plates in 0.1 or 0.2 ml Roswell Park Memorial Institute-1640 medium (RPMI-1640) supplemented with 5–40 µl PHA/ml, 20% fetal calf serum (FCS), and 40 µM 2-mercapto-ethanol. Depending on blood volume and cell concentrations used, it was possible to obtain up to 1400 well-spread metaphases from one venepuncture.
Left Ventricular Morphology and Systolic Function in Sleep-Disordered Breathing
Authors: Chami Hassan A. , Devereux Richard B. , Gottdiener John S. , Mehra Reena , Roman Mary J. , Benjamin Emelia J. , Gottlieb Daniel J.
Published: May 2008

Background—

Whether sleep-disordered breathing (SDB) is a risk factor for left ventricular (LV) hypertrophy and dysfunction is controversial. We assessed the relation of SDB to LV morphology and systolic function in a community-based sample of middle-aged and older adults.

Methods and Results—

The present study was a cross-sectional observational study of 2058 Sleep Heart Health Study participants (mean age 65±12 years; 58% women; 44% ethnic minorities) who had technically adequate echocardiograms. A polysomnographically derived apnea-hypopnea index (AHI) and hypoxemia index (percent of sleep time with oxyhemoglobin saturation <90%) were used to quantify SDB severity. LV mass index was significantly associated with both AHI and hypoxemia index after adjustment for age, sex, ethnicity, study site, body mass index, current and prior smoking, alcohol consumption, systolic blood pressure, antihypertensive medication use, diabetes mellitus, and prevalent myocardial infarction. Adjusted LV mass index was 41.3 (SD 9.90) g/m
2.7
in participants with AHI <5 (n=957) and 44.1 (SD 9.90) g/m
2.7
in participants with AHI ≥30 (n=84) events per hour. Compared with participants with AHI <5, those with AHI ≥30 had an adjusted odds ratio of 1.78 (95% confidence interval 1.14 to 2.79) for LV hypertrophy. A higher AHI and higher hypoxemia index were also associated with larger LV diastolic dimension and lower LV ejection fraction, with a trend toward lower LV fractional shortening. LV wall thickness was significantly associated with the hypoxemia index but not with AHI. Left atrial diameter was not associated with either SDB measure.

Conclusions—

In a community-based cohort, SDB is associated with echocardiographic evidence of increased LV mass and reduced LV systolic function.
Cross-Sectional Relations of Digital Vascular Function to Cardiovascular Risk Factors in the Framingham Heart Study
Authors: Hamburg Naomi M. , Keyes Michelle J. , Larson Martin G. , Vasan Ramachandran S. , Schnabel Renate , Pryde Moira M. , Mitchell Gary F. , Sheffy Jacob , Vita Joseph A. , Benjamin Emelia J.
Published: May 2008

Background—

Digital pulse amplitude augmentation in response to hyperemia is a novel measure of peripheral vasodilator function that depends partially on endothelium-derived nitric oxide. Baseline digital pulse amplitude reflects local peripheral arterial tone. The relation of digital pulse amplitude and digital hyperemic response to cardiovascular risk factors in the community is unknown.

Methods and Results—

Using a fingertip peripheral arterial tonometry (PAT) device, we measured digital pulse amplitude in Framingham Third Generation Cohort participants (n=1957; mean age, 40±9 years; 49% women) at baseline and in 30-second intervals for 4 minutes during reactive hyperemia induced by 5-minute forearm cuff occlusion. To evaluate the vascular response in relation to baseline, adjusting for systemic effects and skewed data, we expressed the hyperemic response (called the PAT ratio) as the natural logarithm of the ratio of postdeflation to baseline pulse amplitude in the hyperemic finger divided by the same ratio in the contralateral finger that served as control. The relation of the PAT ratio to cardiovascular risk factors was strongest in the 90- to 120-second postdeflation interval (overall model
R
2
=0.159). In stepwise multivariable linear regression models, male sex, body mass index, ratio of total to high-density lipoprotein cholesterol, diabetes mellitus, smoking, and lipid-lowering treatment were inversely related to PAT ratio, whereas increasing age was positively related to PAT ratio (all
P
<0.01).

Conclusions—

Reactive hyperemia produced a time-dependent increase in fingertip pulse amplitude. Digital vasodilator function is related to multiple traditional and metabolic cardiovascular risk factors. Our findings support further investigations to define the clinical utility and predictive value of digital pulse amplitude.
Mitochondrial Haplogroups
Authors: Benn Marianne , Schwartz Marianne , Nordestgaard Børge G. , Tybjærg-Hansen Anne
Published: May 2008

Background—

Rare mutations in the mitochondrial genome may cause disease. Mitochondrial haplogroups defined by common polymorphisms have been associated with risk of disease and longevity. We tested the hypothesis that common haplogroups predict risk of ischemic cardiovascular disease, morbidity from other causes, mortality, and longevity in a general population of European descent.

Methods and Results—

We followed 9254 individuals from the Danish general population, in the Copenhagen City Heart Study, prospectively for risk of ischemic cardiovascular disease, morbidity from other causes, and mortality during 25 and 11 years, respectively. Haplogroup frequencies were as follows: H (45.9%), U (15.9%), T (9.9%), J (9.1), K (6.2%), V (4.5%), W/I (3.8%), and Z (3.5%). Hazard ratios for hospitalization due to all cardiovascular disorders (haplogroup U: 1.0 [95% confidence interval{CI}, 0.9 to 1.1]; T: 0.9 [95% CI, 0.8 to 1.0]; J: 1.0 [95% CI, 0.9 to 1.1]; K: 1.0 [95% CI, 0.9 to 1.2]; V: 1.0 [95% CI, 0.9 to 1.2]; W/I: 0.8 [95% CI, 0.7 to 1.0]; Z: 1.0 [95% CI, 0.8 to 1.2]), ischemic heart disease (U: 0.9 [95% CI, 0.8 to 1.1]; T: 0.9 [95% CI, 0.7 to 1.0]; J: 1.1 [95% CI, 0.9 to 1.2]; K: 1.1 [95% CI, 0.9 to 1.3]; V: 1.1 [95% CI, 0.9 to 1.4]; W/I: 1.1 [95% CI, 0.8 to 1.4]; Z: 1.1 [95% CI, 0.8 to 1.4]), and ischemic cerebrovascular disease (U: 1.1 [95% CI, 0.9 to 1.4]; T: 0.9 [95% CI, 0.7 to 1.2]; J: 1.1 [95% CI, 0.9 to 1.4]; K: 1.0 [95% CI, 0.8 to 1.4]; V: 1.1 [95% CI, 0.8 to 1.5]; W/I: 0.8 [95% CI, 0.5 to 1.3]; Z: 0.9 [95% CI, 0.6 to 1.4]) did not differ from 1.0 for any haplogroup versus the most common haplogroup H. Results were similar for hospitalization due to infectious and parasitic diseases, respiratory infections, respiratory disorders, malignant neoplasms, digestive disorders, musculoskeletal disorders, neuropsychiatric disorders, and miscarriages. Likewise, hazard ratios for death from all causes were not different from 1.0 for any haplogroup versus haplogroup H (U: 1.0 [95% CI, 0.8 to 1.1]; T: 0.9 [95% CI, 0.8 to 1.1]; J: 0.9 [95% CI, 0.8 to 1.1]; K: 1.0 [95% CI, 0.8 to 1.2]; V: 1.1 [95% CI, 0.9 to 1.3]; W/I: 0.8 [95% CI, 0.7 to 1.1]; Z: 0.9 [95% CI, 0.7 to 1.2]). Finally, after stratification by major causes of death, hazard ratios remained insignificant.

Conclusions—

Our results do not support an association of mitochondrial haplogroups with risk of ischemic cardiovascular disease, morbidity from other causes, mortality, or longevity in a large general population of European descent.
Torcetrapib Does Not Reduce Atherosclerosis Beyond Atorvastatin and Induces More Proinflammatory Lesions Than Atorvastatin
Authors: de Haan Willeke , de Vries-van der Weij Jitske , van der Hoorn José W.A. , Gautier Thomas , van der Hoogt Caroline C. , Westerterp Marit , Romijn Johannes A. , Jukema J. Wouter , Havekes Louis M. , Princen Hans M.G. , Rensen Patrick C.N.
Published: May 2008

Background—

Although cholesteryl ester transfer protein (CETP) inhibition is regarded as a promising strategy to reduce atherosclerosis by increasing high-density lipoprotein cholesterol, the CETP inhibitor torcetrapib given in addition to atorvastatin had no effect on atherosclerosis and even increased cardiovascular death in the recent Investigation of Lipid Level Management to Understand its Impact in Atherosclerotic Events trial. Therefore, we evaluated the antiatherogenic potential and adverse effects of torcetrapib in humanized
APOE*3-Leiden.CETP
(
E3L.CETP
) mice.

Methods and Results—

E3L.CETP
mice were fed a cholesterol-rich diet without drugs or with torcetrapib (12 mg · kg
−1
· d
−1
), atorvastatin (2.8 mg · kg
−1
· d
−1
), or both for 14 weeks. Torcetrapib decreased CETP activity in both the absence and presence of atorvastatin (−74% and −73%, respectively;
P
<0.001). Torcetrapib decreased plasma cholesterol (−20%;
P
<0.01), albeit to a lesser extent than atorvastatin (−42%;
P
<0.001) or the combination of torcetrapib and atorvastatin (−40%;
P
<0.001). Torcetrapib increased high-density lipoprotein cholesterol in the absence (30%) and presence (34%) of atorvastatin. Torcetrapib and atorvastatin alone reduced atherosclerotic lesion size (−43% and −46%;
P
<0.05), but combination therapy did not reduce atherosclerosis compared with atorvastatin alone. Remarkably, compared with atorvastatin, torcetrapib enhanced monocyte recruitment and expression of monocyte chemoattractant protein-1 and resulted in lesions of a more inflammatory phenotype, as reflected by an increased macrophage content and reduced collagen content.

Conclusions—

CETP inhibition by torcetrapib per se reduces atherosclerotic lesion size but does not enhance the antiatherogenic potential of atorvastatin. However, compared with atorvastatin, torcetrapib introduces lesions of a less stable phenotype.
Hands-On Defibrillation
Authors: Lloyd Michael S. , Heeke Brian , Walter Paul F. , Langberg Jonathan J.
Published: May 2008

Background—

Brief interruptions in chest compressions reduce the efficacy of resuscitation from cardiac arrest. Interruptions of this type are inevitable during hands-off periods for shock delivery to treat ventricular tachyarrhythmias. The safety of a rescuer remaining in contact with a patient being shocked with modern defibrillation equipment has not been investigated.

Methods and Results—

This study measured the leakage voltage and current through mock rescuers while they were compressing the chests of 43 patients receiving external biphasic shocks. During the shock, the rescuer’s gloved hand was pressed onto the skin of the patient’s anterior chest. To simulate the worst case of an inadvertent return current pathway, a skin electrode on the rescuers thigh was connected to an electrode on the patient’s shoulder. In no cases were shocks perceptible to the rescuer. Peak potential differences between the rescuer’s wrist and thigh ranged from 0.28 to 14 V (mean 5.8±5.8 V). The average leakage current flowing through the rescuer’s body for each phase of the shock waveform was 283±140 μA (range 18.9 to 907 μA). This was below several recommended safety standards for leakage current.

Conclusions—

Rescuers performing chest compressions during biphasic external defibrillation are exposed to low levels of leakage current. The present findings support the feasibility of uninterrupted chest compressions during shock delivery, which may enhance the efficacy of defibrillation and cardiocerebral resuscitation.
Acacetin, a Natural Flavone, Selectively Inhibits Human Atrial Repolarization Potassium Currents and Prevents Atrial Fibrillation in Dogs
Authors: Li Gui-Rong , Wang Hong-Bing , Qin Guo-Wei , Jin Man-Wen , Tang Qiang , Sun Hai-Ying , Du Xin-Ling , Deng Xiu-Ling , Zhang Xiao-Hua , Chen Jing-Bo , Chen Lei , Xu Xiao-Hui , Cheng Lik-Cheung , Chiu Shui-Wah , Tse Hung-Fat , Vanhoutte Paul M. , Lau Chu-Pak
Published: May 2008

Background—

The development of atrium-selective antiarrhythmic agents is a current strategy for inhibiting atrial fibrillation (AF). The present study investigated whether the natural flavone acacetin from the traditional Chinese medicine
Xuelianhua
would be an atrium-selective anti-AF agent.

Methods and Results—

The effects of acacetin on human atrial ultrarapid delayed rectifier K
+
current (
I
Kur
) and other cardiac ionic currents were studied with a whole-cell patch technique. Acacetin suppressed
I
Kur
and the transient outward K
+
current (IC
50
3.2 and 9.2 μmol/L, respectively) and prolonged action potential duration in human atrial myocytes. The compound blocked the acetylcholine-activated K
+
current; however, it had no effect on the Na
+
current, L-type Ca
2+
current, or inward-rectifier K
+
current in guinea pig cardiac myocytes. Although acacetin caused a weak reduction in the hERG and hKCNQ1/hKCNE1 channels stably expressed in HEK 293 cells, it did not prolong the corrected QT interval in rabbit hearts. In anesthetized dogs, acacetin (5 mg/kg) prolonged the atrial effective refractory period in both the right and left atria 1 to 4 hours after intraduodenal administration without prolongation of the corrected QT interval, whereas sotalol at 5 mg/kg prolonged both the atrial effective refractory period and the corrected QT interval. Acacetin prevented AF induction at doses of 2.5 mg/kg (50%), 5 mg/kg (85.7%), and 10 mg/kg (85.7%). Sotalol 5 mg/kg also prevented AF induction (60%).

Conclusions—

The present study demonstrates that the natural compound acacetin is an atrium-selective agent that prolongs the atrial effective refractory period without prolonging the corrected QT interval and effectively prevents AF in anesthetized dogs after intraduodenal administration. These results indicate that oral acacetin is a promising atrium-selective agent for the treatment of AF.
Multidimensional Longwave Forcing of Boundary Layer Cloud Systems
Authors: Mechem David B. , Kogan Yefim L. , Ovtchinnikov Mikhail , Davis Anthony B. , Evans K. Franklin , Ellingson Robert G.
Published: May 2008

The importance of multidimensional (MD) longwave radiative effects on cloud dynamics is evaluated in an eddy-resolving model (ERM)—the two-dimensional analog to large-eddy simulation (LES)—framework employing multidimensional radiative transfer [Spherical Harmonics Discrete Ordinate Method (SHDOM)]. Simulations are performed for a case of unbroken, marine boundary layer stratocumulus and a broken field of trade cumulus. “Snapshot” calculations of MD and independent pixel approximation (IPA; 1D) radiative transfer applied to simulated cloud fields show that the total radiative forcing changes only slightly, although the MD effects significantly modify the spatial structure of the radiative forcing. Simulations of each cloud type employing MD and IPA radiative transfer, however, differ little. For the solid cloud case, relative to using IPA, the MD simulation exhibits a slight reduction in entrainment rate and boundary layer total kinetic energy (TKE) relative to the IPA simulation. This reduction is consistent with both the slight decrease in net radiative forcing and a negative correlation between local vertical velocity and radiative forcing, which implies a damping of boundary layer eddies. Snapshot calculations of the broken cloud case suggest a slight increase in radiative cooling, although few systematic differences are noted in the interactive simulations. This result is attributed to the fact that radiative cooling is a relatively minor contribution to the total energetics. For the cloud systems in this study, the use of IPA longwave radiative transfer is sufficiently accurate to capture the dynamical behavior of boundary layer clouds. Further investigations are required to generalize this conclusion for other cloud types and longer time integrations.
Energy of Midlatitude Transient Eddies in Idealized Simulations of Changed Climates
Authors: O’Gorman Paul A. , Schneider Tapio
Published: May 2008

As the climate changes, changes in static stability, meridional temperature gradients, and availability of moisture for latent heat release may exert competing effects on the energy of midlatitude transient eddies. This paper examines how the eddy kinetic energy in midlatitude baroclinic zones responds to changes in radiative forcing in simulations with an idealized moist general circulation model. In a series of simulations in which the optical thickness of the longwave absorber is varied over a wide range, the eddy kinetic energy has a maximum for a climate with mean temperature similar to that of present-day earth, with significantly smaller values both for warmer and for colder climates. In a series of simulations in which the meridional insolation gradient is varied, the eddy kinetic energy increases monotonically with insolation gradient. In both series of simulations, the eddy kinetic energy scales approximately linearly with the dry mean available potential energy averaged over the baroclinic zones. Changes in eddy kinetic energy can therefore be related to the changes in the atmospheric thermal structure that affect the mean available potential energy.
Comparison of Parametric and Nonparametric Bootstrap Methods for Estimating Random Error in Equipercentile Equating
Authors: Zhongmin Cui  , Kolen Michael J.
Published: May 2008

This article considers two methods of estimating standard errors of equipercentile equating: the parametric bootstrap method and the nonparametric bootstrap method. Using a simulation study, these two methods are compared under three sample sizes (300, 1,000, and 3,000), for two test content areas (the Iowa Tests of Basic Skills Maps and Diagrams and the ACT English), for two test lengths (24 items and 75 items), and for different parametric models (polynomial log-linear models with fitted degrees of C =2 through 10). One thousand bootstrap samples were used to estimate standard errors of equating. The parametric bootstrap method was found to estimate standard errors of equating more accurately than the nonparametric bootstrap method in most of the situations examined.
Paternalistic Leadership: A Review and Agenda for Future Research
Authors: Pellegrini Ekin K. , Scandura Terri A.
Published: May 2008

The growing interest in paternalistic leadership research has led to a recent proliferation of diverse definitions and perspectives, as well as a limited number of empirical studies. Consequently, the diversity of perspectives has resulted in conceptual ambiguities, as well as contradictory empirical findings. In this article, the authors review research on paternalistic leadership in an effort to assess the current state of the literature. They investigate the construct of paternalistic leadership and review the findings related to its outcomes and antecedents as well as the various measurement scales used in paternalistic leadership research. On the basis of this review, the article concludes with an agenda for future theoretical and empirical research on this emerging and intriguing new area for leadership research.
Having One's Cake and Eating It, Too
Authors: Mandell Marvin B.
Published: May 2008

Both true experiments and regression discontinuity (RD) designs produce unbiased estimates of effects. However, true experiments are, of course, often criticized on equity grounds, whereas RD designs entail sacrifices in terms of statistical precision. In this article, a hybrid of true experiments and RD designs is considered. This hybrid entails smaller sacrifices in statistical efficiency than RD designs and also is likely to be judged as being considerably more fair than true experiments and possible even RD designs. Moreover, unlike pure RD designs, the hybrid design considered here can be employed in situations in which the variable on which assignment to treatment condition is based takes on only a discrete set of values.
Caregivers' Aspirations, Realities, and Expectations: The CARE Tool
Authors: Keefe Janice , Guberman Nancy , Fancey Pamela , Barylak Lucy , Nahmiash Daphne
Published: May 2008

Caregivers to family and friends are increasingly recognized as essential players in the continued shift of care of dependent populations to the community. Currently, Canadian provincial home care programs have neither a comprehensive policy nor an assessment regarding caregivers' needs. This article describes an assessment tool that takes into account caregivers' reality and conditions and that situates them as essential partners with the formal system and reports on the validation and reliability testing of this tool. Seven sites in Quebec and Nova Scotia involving 40 assessors tested the tool with 168 caregivers. Results suggest that this comprehensive tool enables practitioners to understand caregivers' needs and situations. Focus groups with assessors and interviews with home care administrators revealed that the tool increased worker understanding and awareness of what it means to be a caregiver, ascertained the key caregiver concerns, and identified these needs in rapid succession.
Resource Loss and Naturalistic Reduction of PTSD Among Inner-City Women
Authors: Walter Kristen H. , Hobfoll Stevan E.
Published: May 2008

Halting the process of psychosocial and material resource loss has been theorized as being associated with the reduction of posttraumatic stress disorder (PTSD). This study examines how the limiting of resource loss is related to alleviation of PTSD symptoms among 102 inner-city women, who originally met diagnostic criteria for PTSD after experiencing interpersonal traumatic events such as child abuse, rape, and sexual assault. Participants whose PTSD symptoms improve and become nondiagnostic for PTSD are compared with those who remain diagnostic. The two groups are not significantly different at pretest. However, at the 6-month time point, those who become nondiagnostic for PTSD report less resources loss in three of four domains. This pattern suggests that as PTSD symptoms decrease, women's material and psychosocial resource loss diminishes, which in turn, may aid their recovery process.
The Prosecution of Hate Crimes
Authors: Phillips Nickie D.
Published: May 2008

Since the development of bias crime legislation over the past few decades, scholars have debated the merits of the legislation and questioned its enforcement.1 In light of such concerns, this study presents characteristics of all cases prosecuted as bias crimes in a New Jersey county between 2001 and 2004 and applies the hate crime typology originally developed in 1993. Results show that, in this jurisdiction, the typology is an inadequate tool for classifying cases prosecuted as hate crimes. Approximately one third of the cases are unclassifiable according to the typology. Findings indicate that the typology is useful for understanding cases in which bias is the sole motivation but inadequate for application to the many cases in which bias is a peripheral motivation.
Forty Seven Million Strong, Weak, Wrong, or Right
Authors: Saunders Cynthia M.
Published: May 2008

This article uses the dissemination technique of performance ethnography to present findings from semi-structured interviews conducted with 150 individuals in southern California in summer 2003. Qualitative inquiry informed the methodology using purposive sampling, selecting individuals who are employed and uninsured for health services. Participants were recruited through ads in newspapers, magazines, the World Wide Web, and snowball sampling. Interviews were audio-taped, transcribed, and content-analyzed with NUD*IST software. Results were presented as a formal report in a legislative briefing at the Sacramento, California, State Capitol. The intent of this article is to use performative social science to engage readers, the public, and policy-makers to address difficult issues associated with the lack of health insurance.
Measures for Determining English Language Proficiency and the Resulting Implications for Instructional Provision and Intervention
Authors: Albers Craig A. , Kenyon Dorry M. , Boals Timothy J.
Published: May 2008

Although numerous English language proficiency (ELP) measures currently exist, many were developed prior to the No Child Left Behind Act of 2001 (NCLB). These pre-NCLB measures typically focused on social language proficiency, whereas post-NCLB measures are linked to ELP standards and focus on academic language proficiency (ALP). ELP measures are typically used for accountability purposes and to determine eligibility for services; less attention has been given to their utility in enhancing classroom instruction and intervention provision. Inconsistency in scores between pre- and post-NCLB measures frequently leaves educators wondering whether English language learners (ELLs) have the necessary ALP to benefit from classroom instruction. This study investigates the intervention validity of ELP assessment by examining the concurrent validity of various pre-NCLB measures to a recently developed post-NCLB measure. As hypothesized, results indicate moderate correlations between pre- and post-NCLB measures, suggesting that ALP-focused post-NCLB measures are likely to provide more utility for ELL classroom instruction and intervention provision.
Endovascular Repair of Abdominal Aortic Aneurysm With Chronic Dissection Using an Intravascular Ultrasound-Guided Reentry Catheter
Authors: Lai Kin-Man , Coleman Patrick
Published: May 2008

The incidence of aortic dissection is rare (approximately 10 cases per 1 million inhabitants' year), and reports of an associated aortic dissection within an abdominal aortic aneurysm (AAA) are anecdotal. Historically, such a dissection was treated by operation, but operative risks often excluded patients from intervention. An endovascular approach appears to be more advantageous, but concerns regarding “true” versus “false” lumens and the presence of an intimal flap make an endovascular intervention potentially hazardous. In this report, the authors describe a novel endovascular repair of an AAA with an Excluder device and the successful treatment of a concomitant abdominal aortic dissection using intravascular ultrasound and a Pioneer guided reentry catheter.