Reproductive decision making after the diagnosis of multiple sclerosis (MS).

OBJECTIVE: This study aimed to determine reproductive practices and attitudes of North Americans diagnosed with multiple sclerosis (MS) and the reasons for their reproductive decision making. METHODS: A self-administered questionnaire on reproductive practices was mailed to 13,312 registrants of the North American Research Committee on Multiple Sclerosis (NARCOMS) database who met inclusion criteria for the study. Completed questionnaires were then returned to the authors in an anonymous format for analysis. RESULTS: Among 5949 participants, the majority of respondents (79.1%) did not become pregnant following diagnosis of MS. Of these, 34.5% cited MS-related reasons for this decision. The most common MS-related reasons were symptoms interfering with parenting (71.2%), followed by concerns of burdening partner (50.7%) and of children inheriting MS (34.7%). The most common reason unrelated to MS for not having children was that they already have a "completed family" (55.6%). Of the 20.9% of participants who decided to become pregnant (or father a pregnancy) following a diagnosis of MS, 49.5% had two or more pregnancies. CONCLUSION: This study indicates that an MS diagnosis does not completely deter the consideration of childbearing in MS patients of both genders.

Phosphorylation of centrin during the cell cycle and its role in centriole separation preceding centrosome duplication.

Once during each cell cycle, mitotic spindle poles arise by separation of newly duplicated centrosomes. We report here the involvement of phosphorylation of the centrosomal protein centrin in this process. We show that centrin is phosphorylated at serine residue 170 during the G(2)/M phase of the cell cycle. Indirect immunofluorescence staining of HeLa cells using a phosphocentrin-specific antibody reveals intense labeling of mitotic spindle poles during prophase and metaphase of the cell division cycle, with diminished staining of anaphase and no staining of telophase and interphase centrosomes. Cultured cells undergo a dramatic increase in centrin phosphorylation following the experimental elevation of PKA activity, suggesting that this kinase can phosphorylate centrin in vivo. Surprisingly, elevated PKA activity also resulted intense phosphocentrin antibody labeling of interphase centrosomes and in the concurrent movement of individual centrioles apart from one another. Taken together, these results suggest that centrin phosphorylation signals the separation of centrosomes at prophase and implicates centrin phosphorylation in centriole separation that normally precedes centrosome duplication.

Primary structure of human plasma membrane Ca(2+)-ATPase isoform 3.

The complete coding sequence of the human plasma membrane calcium ATPase (PMCA) isoform 3 was determined from overlapping genomic and cDNA clones. The cDNAs for the two major alternative splice variants 3a (3CII) and 3b (3CI) code for proteins of 1173 and 1220 amino-acid residues, respectively, which show 98% identity with the corresponding rat isoforms. On a multiple human tissue Northern blot, a major PMCA3 transcript of about 7 kb was detected exclusively in the brain, demonstrating the highly restricted pattern of expression of this isoform to human neuronal tissues. With the elucidation of the human PMCA3 primary structure, complete sequence information is now available for the entire family of human PMCA isoforms.

Structure of the human CALM1 calmodulin gene and identification of two CALM1-related pseudogenes CALM1P1 and CALM1P2.

The human CALM1 calmodulin gene has been isolated and characterized. The gene contains six exons spread over about 10 kb of genomic DNA. The exon-intron structure is identical to that of the human CALM3 and of the rat CALM1 and CALM3 genes. A cluster of transcription-start sites was identified 200 bp upstream of the ATG translation-start codon, and several putative regulatory elements were found in the 5' flanking region as well as in intron 1. Sequence comparison with the rat CALM1 gene revealed significant similarities in the promoter regions of the two genes and an even more striking degree of identity (70%) in the available intron 1 sequences. A short CAG trinucleotide repeat region was identified in the 5' untranslated region of the human CALM1 gene; this sequence is not conserved in the rat counterpart. Expression of the CALM1 gene was detected in all human tissues tested, although at varying levels. A 1.7-kb mRNA was uniformly present at comparable levels, whereas a 4.2-kb mRNA species was particularly abundant in brain and skeletal muscle. Clones for two different CALM1-related pseudogenes CALM1P1 and CALM1P2 were also isolated and characterized. Both pseudogenes are intronless and non-functional as judged from the presence of mutations abolishing the open reading frame. Genomic Southern analysis indicates that the human CALM1 gene/pseudogene subfamily comprises at least three but probably no more than four members. The entire family consists of three bona fide CALM genes, at least one expressed calmodulin-like CALML gene as well as at least five pseudogenes.

Centrin is a component of the pericentriolar lattice.

Here, we use three polyclonal anticentrin antisera designated 08/28, 26/14-1, and 26/14-2 to further characterize the pericentriolar lattice of metazoan cells. All of these antibodies give an indistinguishable localization pattern that consists of a constellation of pericentrosomal spots. In QT6 cells these spots are few in number and closely associated with the centriolar region, whereas in PtK2 cells they are more numerous and distributed further from the point of microtubule focus. In mitotic cells, centrin is localized to the spindle poles and spindle apparatus. We demonstrate here that the pericentriolar lattice of PtK2 and QT6 cells is, in part, composed of proteins characterized by acidic pIs (4.4 to 5.4), low molecular mass (M(r) 18,500-21,000), and calcium-binding; these attributes and the immunoreactivity of these proteins to anticentrin antibodies indicate that they are centrin isoforms of metazoan cells. Finally, we confirm our earlier observation that PtK2 cells contain a centrin-related protein of M(r) 165,000; QT6 cells also contain centrin-related proteins (M(r) 64,000-165,000). We conclude that centrin is a component of the pericentriolar lattice of higher eukaryotic centrosomes.

Localization of the centrin-related 165,000-Mr protein of PtK2 cells during the cell cycle.

In this study, we follow changes in localization of the centrin-related 165,000-Mr protein of PtK2 cells during the cell cycle. This protein is a component of a pericentriolar lattice that consists of pericentriolar satellites, pericentriolar matrix, and basal feet (Baron A.T., and J.L. Salisbury, J. Cell Biol. 107:2669-2678, 1988). By immunofluorescence microscopy, the 165,000-Mr protein is seen as a constellation of pericentrosomal spots. We observe that cells in late G1 and S are characterized by a dense centrosomal focus of spots with additional spots dispersed throughout the cytoplasm. In G2, one bright centrosomal focus of clustered spots is observed. As the cells proceed through prophase this single focus divides, forming two foci that move toward opposite sides of the nucleus. During prometaphase, each polar focus of spots disperses. At metaphase, the spots are distributed throughout each half-cytoplast from the poles to the chromosomes. During anaphase chromosome movement, some spots are seen beside and behind the trailing chromosome arms while others are clustered at the poles. At telophase, pericentrosomal spots radiate from the poles to surround each mass of chromatin. In early G1, pericentrosomal spots surround each newly formed nucleus. We conclude that the 165,000-Mr protein is a dynamic component of both the centrosome (pericentriolar matrix) and the mitotic apparatus (spindle matrix).