By identifying a change in fetal activity state, fetal movement counting may help to reduce the possibility of stillbirth. Concern has arisen that such a focus on fetal activity may cause undue maternal anxiety. A prospective, controlled trial was conducted to determine whether fetal movement counting induced anxiety or other deleterious psychological effects in low-risk primigravidas. A sample of 613 healthy pregnant women was randomly assigned at 28 weeks' gestation to fetal movement counting, sleep recording, or a nonrecording control group. State and trait of anxiety, belief in sources of personal control, and attitudes toward pregnancy and infant were assessed at 28 and 37 weeks' gestation. Participation rates were high (91.4%) across all groups. Most women (90%) assigned to count fetal movements did so on a daily basis (95% of days). No significant changes in psychological status occurred in the three groups as a result of self-monitoring conditions. Independent of group assignment, all women showed a slight increase in transient state and decrease in trait of anxiety from 28 to 37 weeks. Internal locus of control and positive attitudes toward the infant increased slightly, and feelings of well-being decreased slightly for all women. It was concluded that women are willing to record fetal activity, and that fetal movement counting does not cause deleterious psychological effects in low-risk pregnant women.

Adult↗

PubMed1994

Rapid staining with carcinoembryonic antigen aids limited excision of extramammary Paget's disease treated by Mohs surgery.

Extensive extramammary Paget's (EMPD) disease of the perineum in a 68-year-old man was treated by Mohs surgery. To facilitate identification of involved tissue a rapid staining carcinoembryonic antigen was used. This technique proved a useful adjunct to conventional hemotoxylin-eosin (H&E) stains. It was especially useful in highlighting involvement in areas of marked dysplasia/artifact where discrimination is often difficult. It is recommended that such a technique offers considerable benefits over H&E staining when confronted by such tissue morphology.

Aged↗

PubMed1994

Two different types of double-strand breaks in Saccharomyces cerevisiae are repaired by similar RAD52-independent, nonhomologous recombination events.

In haploid rad52 Saccharomyces cerevisiae strains unable to undergo homologous recombination, a chromosomal double-strand break (DSB) can be repaired by imprecise rejoining of the broken chromosome ends. We have used two different strategies to generate broken chromosomes: (i) a site-specific DSB generated at the MAT locus by HO endonuclease cutting or (ii) a random DSB generated by mechanical rupture during mitotic segregation of a conditionally dicentric chromosome. Broken chromosomes were repaired by deletions that were highly variable in size, all of which removed more sequences than was required either to prevent subsequent HO cleavage or to eliminate a functional centromere, respectively. The junction of the deletions frequently occurred where complementary strands from the flanking DNA could anneal to form 1 to 5 bp, although 12% (4 of 34) of the events appear to have occurred by blunt-end ligation. These types of deletions are very similar to the junctions observed in the repair of DSBs by mammalian cells (D. B. Roth and J. H. Wilson, Mol. Cell. Biol. 6:4295-4304, 1986). When a high level of HO endonuclease, expressed in all phases of the cell cycle, was used to create DSBs, we also recovered a large class of very small (2- or 3-bp) insertions in the HO cleavage site. These insertions appear to represent still another mechanism of DSB repair, apparently by annealing and filling in the overhanging 3' ends of the cleavage site. These types of events have also been well documented for vertebrate cells.

Base Sequence↗

PubMed1994

A chromosome breakage assay to monitor mitotic forces in budding yeast.

During the eukaryotic cell cycle, genetic material must be accurately duplicated and faithfully segregated to each daughter cell. Segregation of chromosomes is dependent on the centromere, a region of the chromosome which interacts with mitotic spindle microtubules during cell division. Centromere function in the budding yeast, Saccharomyces cerevisiae, can be regulated by placing an inducible promotor adjacent to centromere DNA. This conditional centromere can be integrated into chromosome III to generate a conditionally functional dicentric chromosome. Activation of the dicentric chromosome results in a transient mitotic delay followed by the generation of monocentric derivatives. The propagation of viable cells containing these monocentric derivative chromosomes is dependent upon the DNA repair gene RAD52, indicating that double-strand DNA breaks are structural intermediates in the dicentric repair pathway. We have used these conditionally dicentric chromosomes to monitor the exertion of mitotic forces during cell division. Analysis of synchronized cells reveal that lethality in dicentric, rad52 mutant cells occurs during G2/M phase and is concomitant with the transient mitotic delay. the delay is largely dependent upon the cell cycle checkpoint gene RAD9, which is involved in monitoring DNA damage. These data demonstrate that DNA lesions resulting from dicentric activation are responsible for signalling the mitotic delay. Since the delay precedes the decline of p34cdc28 kinase activity, mitotic forces sufficient to result in dicentric chromosome breakage are generated prior to spindle elongation and anaphase onset in yeast.

Base Sequence↗

PubMed1993

Disruption of mitotic spindle orientation in a yeast dynein mutant.

Dynein motor isoforms have been implicated as potential kinetochore-associated motors that power chromosome-to-pole movements during mitosis. The recent identification and sequence determination of genes encoding dynein isoforms has now permitted the in vivo analysis of dynein function in mitosis. In this report we describe the identification and mutational analysis of the gene, DHC1, encoding a dynein heavy chain isoform in Saccharomyces cerevisiae. Sequence analysis of a 9-kb genomic fragment of the DHC1 gene predicts a polypeptide highly homologous to dynein sequences characterized from sea urchin, Dictyostelium, Drosophila, and rat. Mutations in the yeast dynein gene disrupt the normal movement of the spindle into budding daughter cells but have no apparent effect on spindle assembly, spindle elongation, or chromosome segregation. Our results suggest that, in yeast, a dynein microtubule motor protein has a nonessential role in spindle assembly and chromosome movement but is involved in establishing the proper spindle orientation during cell division.

Amino Acid Sequence↗

PubMed1993

The centromere frontier: kinetochore components, microtubule-based motility, and the CEN-value paradox.

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Animals↗

PubMed1993

Genetic dissection of centromere function.

A system to detect a minimal function of Saccharomyces cerevisiae centromeres in vivo has been developed. Centromere DNA mutants have been examined and found to be active in a plasmid copy number control assay in the absence of segregation. The experiments allow the identification of a minimal centromere unit, CDE III, independently of its ability to mediate chromosome segregation. Centromere-mediated plasmid copy number control correlates with the ability of CDE III to assemble a DNA-protein complex. Cells forced to maintain excess copies of CDE III exhibit increased loss of a nonessential artificial chromosome. Thus, segregationally impaired centromeres can have negative effects in trans on chromosome segregation. The use of a plasmid copy number control assay has allowed assembly steps preceding chromosome segregation to be defined.

Centromere↗

PubMed1992

Measurement of the ratio B(W--> tau nu )/B(W-->e nu ) in pp-bar collisions at sqrt s =1.8 TeV.

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Journal Article↗

PubMed1992

Controllability and duration of stress alter central nervous system depressant-induced sleep time in rats.

Rats were exposed to either 80 escapable shocks or yoked inescapable shocks and then injected with several hypnotic doses of sodium pentobarbital, midazolam, or ethanol; their sleep-time duration was compared with that of naive controls. Inescapable shock exposure resulted in a significant increase in ethanol-induced sleep time compared with the escapable shock and naive control groups. Both escape and yoked groups showed an increase in barbiturate-induced sleep time compared with controls, although no difference was observed for midazolam. Acute stress (twenty 5-s inescapable shocks) did not alter the depressant-induced sleep time for any of the drugs tested. These results illustrate the importance of psychological aspects of stress and its influence on the potency of certain depressants.

Animals↗

PubMed1991

A dynamin-like protein encoded by the yeast sporulation gene SPO15.

The tightly centromere-linked gene SPO15 is essential for meiotic cell division in the yeast Saccharomyces cerevisiae. Diploid cells without the intact SPO15 gene product are able to complete premeiotic DNA synthesis and genetic recombination, but are unable to traverse the division cycles. Electron microscopy of blocked cells reveals a duplicated but unseparated spindle-pole body. Thus cells are unable to form a bipolar spindle. Sequence analysis of SPO15 DNA reveals an open reading frame that predicts a protein of 704 amino acids. This protein is identical to VPS1, a gene involved in vacuolar protein sorting in yeast which has significant sequence homology (45% overall, 66% over 300 amino acids) to the microtubule bundling-protein, dynamin. The SPO15 gene product expressed in Escherichia coli can be affinity-purified with microtubules. SPO15 encodes a protein that is likely to be involved in a microtubule-dependent process required for the timely separation of spindle-pole bodies in meiosis.

Amino Acid Sequence↗

PubMed1990

Heterogeneity and maintenance of centromere plasmid copy number in Saccharomyces cerevisiae.

We developed a novel approach to quantitate the heterogeneity of centromere number in yeast, and the cellular capacity for excess centromeres. Small circular plasmids were constructed to contain the CUP1 metallothionein gene. ARS1 (autonomously replicating sequence) and a conditionally functional centromere (GAL1-GAL10 promoter controlled centromere). The CUP1 gene provided a gene dosage marker, and therefore a genetic determinant of plasmid copy number. Growth of cells on glucose is permissive for centromere function, while growth on galactose renders the centromere nonfunctional and the plasmids are segregated in an asymmetric fashion. We identified "lines" of cells containing increased numbers of plasmids after transformation. Cell lines containing as many as five to ten active centromeres are stably maintained in the absence of genetic selection. Thus haploid yeast cells can tolerate a 50% increase in their centromere number without affecting progression through the cell cycle. This system provides the opportunity to address issues of specific cellular controls on centromere copy number.

Centromere↗

PubMed1990

Effect of live attenuated, cold recombinant (CR) influenza virus vaccines on pulmonary function in healthy and asthmatic adults.

The effects of intranasal inoculation with live attenuated, CR influenza virus vaccines on pulmonary function in healthy and asthmatic adults were evaluated in placebo-controlled, double-blind studies. In 46 healthy adult volunteers, there were no statistically significant alterations in pulmonary function as measured by spirometry and histamine bronchoprovocation tests in the first week following monovalent CR influenza virus vaccine [type A (H3N2, H1N1) and type B]. Among healthy adults with pre-inoculation PC20s less than 10 mg ml-1, 8/12 were infected following vaccination but no significant alterations occurred in histamine bronchoprovocation. In 11 asthmatic adults, no statistically significant alterations in pulmonary function, as measured by spirometry, were noted during the first 7 days postinoculation with bivalent CR influenza virus vaccine type A (H3N2 and H1N1). Postinoculation respiratory illnesses were more common in CR influenza virus vaccine recipients than placebo recipients, but they were mild, consisting of afebrile pharyngitis and transient rhinorrhea. Attenuated CR influenza virus vaccines do not appear to impair pulmonary function during the first week following immunization of healthy and asthmatic adults.

Adolescent↗

PubMed1990

Paraplegia from schistosomiasis.

Paraplegia, a rare complication of schistosomiasis has been reported in the literature. However, a detailed description of neurological recovery and long-term functional follow-up has not been published. In the cases presented, one patient experienced slow recovery over several years and remains nonambulatory. The other patient, infected at the same time and place, has completely recovered neurologically. Recovery was independent of the rehabilitation efforts applied. Case reports, discussion of spinal cord injury due to schistosomiasis and recommendations for treatment are presented in detail.

Adult↗

PubMed1990

Nucleosome depletion alters the chromatin structure of Saccharomyces cerevisiae centromeres.

Saccharomyces cerevisiae centromeric DNA is packaged into a highly nuclease-resistant chromatin core of approximately 200 base pairs of DNA. The structure of the centromere in chromosome III is somewhat larger than a 160-base-pair nucleosomal core and encompasses the conserved centromere DNA elements (CDE I, II, and III). Extensive mutational analysis has revealed the sequence requirements for centromere function. Mutations affecting the segregation properties of centromeres also exhibit altered chromatin structures in vivo. Thus the structure, as delineated by nuclease digestion, correlated with functional centromeres. We have determined the contribution of histone proteins to this unique structural organization. Nucleosome depletion by repression of either histone H2B or H4 rendered the cell incapable of chromosome segregation. Histone repression resulted in increased nuclease sensitivity of centromere DNA, with up to 40% of CEN3 DNA molecules becoming accessible to nucleolytic attack. Nucleosome depletion also resulted in an alteration in the distribution of nuclease cutting sites in the DNA surrounding CEN3. These data provide the first indication that authentic nucleosomal subunits flank the centromere and suggest that nucleosomes may be the central core of the centromere itself.

Chromatin↗