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C Mitchell

Publications and source records attributed to C Mitchell.

At least 19 recordsLinked to original sources
PubMed1992

Regional transfusion centre preoperative autologous blood donation programme: the first two years.

OBJECTIVE: To assess the efficacy of a regional autologous blood donation programme. DESIGN: Clinical and laboratory data were collected and stored prospectively. Transfusion data were collected retrospectively from hospital blood bank records. SETTING: Northern Region Blood Transfusion Service and 14 hospitals within the Northern Regional Health Authority. SUBJECTS: 505 patients referred for autologous blood donation before elective surgery. MAIN OUTCOME MEASURES: Patient eligibility, adverse events from donation, autologous blood units provided, and autologous and allogeneic blood units transfused within 10 days of operation. RESULTS: Of 505 patients referred, 354 donated at least one unit. 78 of 151 referred patients who did not donate were excluded at the autologous clinic, mostly because of anaemia or ischaemic heart disease. In 73 cases the patient, general practitioner, or hospital consultant decided against donation. 363 autologous procedures were undertaken. In 213 (59%) cases all requested units were provided. The most common reasons for incomplete provision were late referral or anaemia. Adverse events accompanied 24 of 928 donations (2.6%). Transfusion data were obtained for 357 of the 363 procedures. 281 donors were transfused; autologous blood only was given to 225, autologous and allogeneic blood was given to 52, and allogeneic blood only was given to four. 648 of 902 (72%) units of autologous blood were transfused. Complete provision of requested autologous units was followed by allogeneic transfusion in 12 of 208 procedures (5.8%). Incomplete provision was followed by allogeneic transfusion in 44 of 149 procedures (30%). CONCLUSIONS: This study shows the feasibility of a regional autologous transfusion programme. Autologous donors only infrequently received allogeneic transfusion. Patients should be appropriately selected and referred early.

Blood Banks↗
PubMed1992

Multistage carcinogenesis in paediatric and adult cancers.

Retinoblastoma (RB) and the familial adenomatous polyposis/colorectal cancer (FAP/CRC) complex provide well-characterised examples of multistage carcinogenesis and inheritance of a predisposition to cancer. Retinoblastoma appears to conform to the simple two-step model first proposed by Knudson. The gene responsible for RB, now called Rb1, has been located in chromosome region 13q14. The Rb1 gene has been cloned and subjected to extensive analysis. It is probable that the Rb1 gene product has a role in the regulation of transcription. The familial form of RB occurs as the result of a germline mutation of one of the copies of the Rb1 gene. Colorectal cancer, in contrast, appears to be the result of four or five steps involving both activation of oncogenes and inactivation of antioncogenes. The FAP gene has been located in chromosome region 5q21 by genetic linkage, and a candidate gene, MCC (mutated in colon cancer), has been cloned. Other mutations in previously-identified genes that have been identified as important in the genesis of CRC include the activation of p53 and of Ki-ras. A gene lying in chromosome region 18q which is deleted in colorectal cancer, and hence named DCC has been cloned. Its protein product has sequence homology to neural cell adhesion molecules and other related cell-surface glycoproteins. Delineation of the genes involved in the development of tumours such as RB and CRC provides insight into the mechanisms by which sequential mutations result in carcinogenesis.

Adenomatous Polyposis Coli↗
PubMed1992

Possible evidence for genomic imprinting in childhood acute myeloblastic leukaemia associated with monosomy for chromosome 7.

Monosomy or deletion of chromosome 7 is a frequent finding in both de novo and secondary acute myeloid leukaemia (AML) and myelodysplastic syndromes (MDS). Based on analysis of deletions of chromosome 7 in such patients, it has been suggested that there is a critical region of the chromosome lying within bands q21-q31. We have examined bone marrow and peripheral blood samples from 10 patients with MDS, AML and biphenotypic acute leukaemia who had monosomy for or rearrangement of chromosome 7, seeking evidence of non-random allele loss that might suggest the presence of imprinted genes on the chromosome. Bone marrow cells from one patient with the infant monosomy 7 syndrome had loss of maternal alleles as did two patients with biphenotypic leukaemia. Five out of five patients with MDS and both patients with de novo AML had loss of paternal alleles. One of the latter patients had a del(7) (q31q36) rather than monosomy 7. These findings suggest that imprinting of a gene(s) on chromosome 7, within the bands q31-q36, may be of importance in MDS and AML. Despite the reported increased incidence of AML amongst relatives of patients with cystic fibrosis (CF) the gene for which lies in chromosome region 7q31, none of the patients nor parents studied here appeared to be carriers of the most common gene mutation seen in patients with CF, the delta F508.

Acute Disease↗
PubMed1992

The amino acid sequence of a Bacillus subtilis phosphoprotein that matches an orfY-tsr coding sequence.

Bacillus subtilis contains a 30 kDa protein which was phosphorylated during late vegetative growth and sporulation. The sequence for the N-terminal 16 amino acids was found to be identical to the predicted sequence for the N-terminus of a small open reading frame, orfY, but diverged from the predicted sequence thereafter. The orfY region was resequenced and contained one less adenine residue than previously reported, resulting in an open reading frame from within orfY through the entire coding region for tsr which follows orfY. The predicted orfY-tsr amino acid sequence showed 24% identity to Escherichia coli fructose-1,6-bisphosphate aldolase. Two mutants in the tsr region had 2-5% of wild-type aldolase and the nucleotide sequences showed missense mutations. These results indicate that orfY-tsr encodes aldolase and should be renamed fba1.

Amino Acid Sequence↗
PubMed1992

Amino acid sequences of several Bacillus subtilis proteins modified by apparent guanylylation.

Bacillus subtilis cell extracts, prepared at different times during growth, contained several proteins that were apparently guanylylated in vitro with [alpha-32P]-GTP. Four of the proteins were partially purified and the N-terminal amino acid sequences (13 to 20 residues) were determined. One sequence had 84% identity to Bacillus stearothermophilus triosephosphate isomerase, two were 100% identical to the predicted sequences of the B. subtilis ptsI and ptsH genes while no identity was found for the fourth sequence. This apparent guanylylation occurred with proteins involved in glucose metabolism, although the significance is unknown.

Amino Acid Sequence↗
PubMed1992

Identification of proteins phosphorylated by ATP during sporulation of Bacillus subtilis.

Protein phosphorylation in Bacillus subtilis was assayed in vitro by using extracts prepared from cells at various times during growth and sporulation. At least six proteins were labeled in vitro by using [gamma-32P]ATP and extracts of vegetative cells. In extracts prepared at the end of exponential growth and during stationary phase, 12 to 13 proteins were labeled. Seven of the phosphoproteins were purified by fast-performance liquid chromatography and polyacrylamide gel electrophoresis, blotted to Immobilon membranes, and subjected to partial protein sequencing. One of the sequences had sequence homology (greater than 45%) to elongation factor G from several bacterial species, and four sequences matched the predicted amino-terminal sequences of the outB, orfY-tsr, orfU, and ptsH genes.

Adenosine Triphosphate↗
PubMed1991

International EMS: lessons learned in Costa Rica.

Health care planners in Costa Rica, seeking to upgrade their emergency medical services, contracted with United States agencies for additional funding and established a national program for the development of an emergency medical service system. Three years later some of the problems and accomplishments of both the planning and early implementation phases have been identified and include the importance of a detailed assessment of current system components, resources, and priorities; the early implementation of an accurate data collection system; early planning for system self-sufficiency; the vital role of the lead agency with formal lines of authority; the careful development of local expertise and leadership. The continuing efforts in Costa Rica provide a valuable resource for other countries as they face their emergency health care needs.

Costa Rica↗
PubMed1991

A hospital-based prospective study of perinatal infection with human immunodeficiency virus type 1.

Most infants with pediatric acquired immunodeficiency syndrome and infections with human immunodeficiency virus type 1 (HIV-1) are infected perinatally by their mothers. To determine the proportion of exposed infants who are infected, we conducted a hospital-based prospective study in HIV-1-infected women whose infants were delivered at a single metropolitan hospital in Miami, Fla. A population of uninfected women and their infants was also enrolled and followed longitudinally for 2 years to assess laboratory and clinical measurements. The median follow-up is now 18 months for 82 infants born to HIV-1-infected mothers. The proportion of infected infants in this group is 0.30 (25/82). None of the infants born to 110 HIV-1-seronegative mothers were seropositive. Infected infants were easily distinguished from noninfected infants by virus isolation. No single immunologic or hematologic measure was predictive of infection for all infants at risk for HIV-1 infection who were 6 months of age or younger. As a group, however, infected infants could be distinguished from uninfected index infants by a number of immunologic measures by 6 months of age; the absolute number of CD4+ lymphocytes and the CD4+/CD8+ lymphocyte ratio were the variables most predictive of infection. As in retrospective studies, clinical disease developed in 80% of infected infants within the first 24 months of life. This study provides documentation of HIV-1 perinatal transmission risk and early correlates of infection in young infants from a single hospital.

Acquired Immunodeficiency Syndrome↗
PubMed1991

Absence and labour turnover in a foundry attributable to respiratory disease.

A survey of foundry workers was undertaken to assess the effect of respiratory disease on both absence in the year prior to the survey and labour turnover since a cross-sectional study of respiratory morbidity five years previously. The presence of a wheeze, but not an objective disturbance of airway function, was predictive of absence. Those with respiratory illness, detected in the survey five years previously, were no more likely to have left the foundry than those without such illness. Limited job opportunities may discourage moulders with respiratory disease from leaving the foundry. Absence was not related to cigarette smoking, the presence of bronchial hyperreactivity, or a positive skin test to common allergens. In view of the small number of subjects in this study, studies of larger work populations should be undertaken to further assess the effect of subjective and objective indices of respiratory morbidity on absence and labour turnover.

Absenteeism↗
PubMed1991

Effect of thyroid stimulating hormone on adaptive behaviour in Down's syndrome.

Patients with Down's syndrome are particularly vulnerable to the development of both hypothyroidism and Alzheimer's disease. Both hypothyroidism and Alzheimer's disease may be associated with elevated serum concentrations of thyroid stimulating hormone. In a group of institutionalized Down's syndrome patients with normal thyroid function, global scores of ability were higher than in a group of patients with elevated thyroid stimulating hormone levels in the presence of normal T3 and T4. The actual concentrations of thyroid stimulating hormone were shown to be significantly and inversely correlated with scores of global abilities. If these findings are reproducible, the authors believe that thyroid stimulating hormone estimation may provide confirmatory evidence of clinical dementia in this group of mentally handicapped individuals.

Adaptation, Psychological↗
PubMed1991

Cocaine and pregnant women: a hospital study.

How prevalent is cocaine use among pregnant women? This study of pregnant and newborn populations at Broadlawns Medical Center in Des Moines showed positive rates of 7.1% and 3.6%, respectively. The study also showed that accepted risk factors are not reliable indicators of drug use.

Cocaine↗
PubMed1991

Her only chance.

Explore the source record for details and available documents.

Adult↗
PubMed1990

Sex differences in visual-spatial ability: the role of performance factors.

Two studies were designed to explore the role of performance factors as sources of the frequently noted higher male scores on visual-spatial ability tests. In the first study, the mental rotations test (MRT) was administered to male and female college students of equally high quantitative ability (based on SAT math scores). Although males had significantly more correct responses on the test than did females, their advantage was eliminated when the ratio of correct responses to items attempted was used as the dependent measure. In the second study, the same test was administered to new groups of male and female college students. In this sample, the males had significantly higher SAT math scores. The MRT was administered under standard, timed conditions and under untimed conditions. Both raw and ratio scores were calculated. With SAT math score as the covariate, analyses of covariance indicated that males demonstrated higher performance in the timed, raw-score condition but not in the untimed or in the ratio-score conditions. The theoretical and social policy implications of these studies are discussed.

Adolescent↗