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C Cotton

Publications and source records attributed to C Cotton.

8 recordsLinked to original sources
PubMed2001

Sex- and age-of-onset-based locus heterogeneity in asthma.

Asthma is a complex disease with a genetic component. The results of genome-wide linkage studies imply that locus heterogeneity is likely to be an important feature of the genetics of asthma. To attempt to reduce locus heterogeneity, we hypothesized that the following may form the bases for locus heterogeneity at some asthma susceptibility loci: sex of affected individuals, parental origin of alleles shared by affected sib pairs, and age of onset of wheeze. Analysis of such strata may assist in the identification of novel susceptibility loci, or reveal the basis for locus heterogeneity at previously identified loci. Genotype and phenotype data from genome-wide linkage searches for asthma susceptibility loci from three populations were analyzed. Some regions demonstrated evidence for linkage to affected individuals of a particular sex. There was evidence for excess maternal allele sharing at regions on chromosomes 9 and 11. Regions on chromosomes 2 and 6 were linked to late and early age at onset of wheeze in asthma, respectively. These analyses suggest that the bases that we selected for stratification may be appropriate at certain susceptibility loci for asthma, and may therefore assist in the fine mapping of such loci. Differences in such variables between studies may explain apparent nonreplication of linkage results.

Adolescent↗
PubMed1997

Immuno and functional characterization of CFTR in submandibular and pancreatic acinar and duct cells.

Cystic fibrosis results from defective Cl- channel activity mediated by the cystic fibrosis transmembrane conductance regulator (CFTR) gene product. In the gastrointestinal tract this is manifested in abnormal salivary secretion and pancreatic insufficiency. This is generally attributed to defective Cl- transport by the ductal system of the glands. We provide the first immunocytochemical and functional evidence for expression of CFTR protein and Cl- current in rat and mouse submandibular gland (SMG) and pancreatic acinar cells, a site proximal to the ductal system of these secretory glands. Monoclonal and polyclonal antibodies recognizing COOH-terminal epitopes of CFTR show that duct and acinar cells from the two glands express CFTR in the luminal membrane. Specificity of the polyclonal antibody was verified by absence of staining in duct and acinar cells of the SMG of cf-/cf- and delta F/delta F mice. Identification of CFTR in acinar cells was aided by demonstrating coexpression of CFTR and type 3 inositol 1,4,5-trisphosphate receptors in the luminal pole of acini and absence of type 3 inositol 1,4,5-trisphosphate receptors in ducts. Electrophysiological characterization in single SMG duct and acinar cells shows the presence of a protein kinase A-activated, voltage- and time-independent, ohmic Cl- current and absence of repolarization-dependent tail currents, all of which are kinetic properties of the CFTR-dependent Cl- channel. In addition, the channel was activated by the nonhydrolyzable ATP analog 5'-adenylylimidodiphosphate and the benzimidazalone NS-004. Channels activated by all activators were inhibited by glibenclamide and a known inhibitory antiserum [anti-CFTR-(505-511)]. Combined immunologic, functional, and pharmacological evidence allows us to conclude that acinar cells of the SMG and pancreas express functional CFTR-dependent Cl- channels. Because this site is proximal to the duct, modification of activity of this channel in acinar cells is likely to contribute to abnormal salivary secretion and pancreatic insufficiency typical of cystic fibrosis.

Animals↗
PubMed1993

Alternate, adjacent 2 and 3:1 meiotic segregation products from a balanced t(13;18) (q12;q11) carrier.

We present a case in which alternate, adjacent 2 and 3:1 meiotic segregations have occurred in the pregnancies of a female carrier of a balanced reciprocal translocation -46,XX,t(13;18) (q12;q11). Products of five conceptions effectively showed trisomy 18q, trisomy 18p or monosomy 18p. This is one of the rare rearrangements which can give rise to a variety of segregation modes including adjacent 2.

Chromosomes, Human, Pair 13↗
PubMed1979

Defective reticuloendothelial system function in rheumatoid arthritis.

The function of the splenic reticuloendothelial system in patients with rheumatoid arthritis (R.A.) was assessed by determining the clearance of autologous heat-damaged erythrocytes from the circulation. 11/13 patients with active R.A. had a defect in the clearance of red cells and there was a significant inverse correlation between splenic function and the level of circulating immune complexes detected by a Clq-binding assay. Splenic function was normal in 13 patients with inactive disease who had been treated with either gold or prednisone. A serial study on 1 patient with active R.A. showed a clear correlation between fluctuations in disease activity, splenic function, and the level of circulating immune complexes.

Adult↗
PubMed1979

Reversal of impaired splenic function in patients with nephritis or vasculitis (or both) by plasma exchange.

By studying the clearance of autologous labeled antibody-coated or heat-damaged erythrocytes, we showed that reversible blockade of the splenic component of reticuloendothelial function existed in 14 of 15 patients referred for treatment of nephritis or vasculitis. In 10 patients treated by plasma exchange--alone in three and combined with steroids and cytotoxic drugs in six--reversal of splenic blockade followed in nine, and in the three patients treated solely by plasma exchange this reversal was demonstrated to occur within 48 hours of the procedure. Only gradual reversal of splenic blockade was found in three of five patients treated by steroids with or without cytotoxic drugs; no change in splenic function was observed in two. When circulating immune complexes were detected by a C1q-binding assay, there was, in serial studies, an approximate inverse correlation between splenic function and the level of C1q-binding material, though hyposplenism was also a feature of patients in whom the C1q-binding assay was negative.

Antigen-Antibody Complex↗
PubMed1975

Contingency awareness in premature infants.

Infants of low birthweight were placed in an artificial contingency situation in which leg movement produced movement of an overhead mobile. When compared with 5 non-contingent controls, these 5 infants showed an increase in frequency of kicks and in the amount of time spent focusing on the mobile.

Age Factors↗
PubMedDate not supplied

Isolation and characterisation of nuv11, a mutation affecting meiotic and mitotic recombination in Aspergillus nidulans.

A mutant of Aspergillus nidulans, designated nuv11, has been isolated as hypersensitive to the monofunctional alkylating agent MNNG and the quasi-UV-mimetic mutagen 4-NQO. The mutation was recessive, resulting from mutation of a single gene which mapped to chromosome IV, and was non-allelic to the previously characterised repair-deficient mutations uvsB and uvsH which are also located on this linkage group. The nuv11 mutation results in slow growth, deficient intragenic and intergenic meiotic recombination, increased spontaneous chromosome instability, and increased intragenic and intergenic mitotic recombination in homozygous diploids. By screening a wild-type gene bank of A nidulans, a clone (pNUV11A40) has been isolated which complements the nuv11 mutation, restoring wild-type responses to both MNNG and 4-NQO.

4-Nitroquinoline-1-oxide↗