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Biomedical subjects

D Campbell

Publications and source records attributed to D Campbell.

At least 19 recordsLinked to original sources
PubMed1992

Identification of epidermal growth factor Thr-669 phosphorylation site peptide kinases as distinct MAP kinases and p34cdc2.

A synthetic peptide modeled after the major threonine (T669) phosphorylation site of the epidermal growth factor (EGF) receptor was an efficient substrate (apparent Km approximately 0.45 mM) for phosphorylation by purified p44mpk, a MAP kinase from sea star oocytes. The peptide was also phosphorylated by a related human MAP kinase, which was identified by immunological criteria as p42mapk. Within 5 min of treatment of human cervical carcinoma A431 cells with EGF or phorbol myristate acetate (PMA), a greater than 3-fold activation of p42mapk was measured. However, Mono Q chromatography of A431 cells extracts afforded the resolution of at least three additional T669 peptide kinases, some of which may be new members of the MAP kinase family. One of these (peak I), which weakly adsorbed to Mono Q, phosphorylated myelin basic protein (MBP) and other MAP kinase substrates, immunoreacted as a 42 kDa protein on Western blots with four different MAP kinase antibodies, and behaved as a approximately 45 kDa protein upon Superose 6 gel filtration. Another T669 peptide kinase (peak IV), which bound more tightly to Mono Q than p42mapk (peak II), exhibited a nearly identical substrate specificity profile to that of p42mapk, but it immunoreacted as a 40 kDa protein only with anti-p44mpk antibody on Western blots, and eluted from Superose 6 in a high molecular mass complex of greater than 400 kDa. By immunological criteria, the T669 peptide kinase in Mono Q peak III was tentatively identified as an active form of p34cdc2 associated with cyclin A. The Mono Q peaks III and IV kinases were modestly stimulated following either EGF or PMA treatments of A431 cells, and they exhibited a greater T669 peptide/MBP ratio than p42mapk. These findings indicated that multiple proline-directed kinases may mediate phosphorylation of the EGF receptor.

Amino Acid Sequence↗
PubMed1992

Characterization of a type II collagen gene (COL2A1) mutation identified in cultured chondrocytes from human hypochondrogenesis.

A subtle mutation in the type II collagen gene COL2A1 was detected in a case of human hypochondrogenesis by using a chondrocyte culture system and PCR-cDNA scanning analysis. Chondrocytes obtained from cartilage biopsies were dedifferentiated and expanded in monolayer culture and then redifferentiated by culture over agarose. Single-strand conformation polymorphism and direct sequencing analysis identified a G----A transition, resulting in a glycine substitution at amino acid 574 of the pro alpha 1(II) collagen triple-helical domain. Morphologic assessment of cartilage-like structures produced in culture and electrophoretic analysis of collagens synthesized by the cultured chondrocytes suggested that the glycine substitution interferes with conversion of type II procollagen to collagen, impairs intracellular transport and secretion of the molecule, and disrupts collagen fibril assembly. This experimental approach has broad implications for the investigation of human chondrodysplasias as well as human chondrocyte biology.

Alleles↗
PubMed1992

Childhood poisoning--a changing profile with scope for prevention.

OBJECTIVES: To study the pattern of poisoning in children admitted to the Children's Hospital between 1983 and 1988; to compare this pattern with the last study of poisoning in childhood from this institution, done in 1956; and to survey knowledge of a sample of general practitioners and pharmacists about common childhood poisonings. DESIGN: A retrospective review of 407 medical records of children admitted after poisoning and a postal questionnaire to 150 randomly selected pharmacists and 150 randomly selected general practitioners. RESULTS: Poisoning accounted for one in 200 admissions to the Children's Hospital. The pattern of poisoning has changed since 1956 when the main agents were kerosene, pesticides, aspirin and digoxin. Now they are the benzodiazepines, iron preparations, paracetamol and anticonvulsants. There were four deaths due to the ingestion of quinine, caustic soda, ferrous sulphate and an arsenic-based weed killer respectively. Five per cent of the admissions resulted in significant morbidity. Sixty-five per cent of general practitioners and 45% of pharmacists responded to the questionnaire. The high toxicity of quinine, anticonvulsants, iron preparations and digoxin was not widely appreciated by over 50% of the general practitioners while over 60% of the pharmacists were not aware of the high toxicity of anticonvulsants and paracetamol. CONCLUSIONS: Although the pattern of childhood poisoning has changed, it remains a significant but largely preventable cause of mortality and morbidity.

Australia↗
PubMed1992

Spontaneous chylothorax in Noonan syndrome. Treatment with prednisone.

OBJECTIVE: To describe a case of spontaneous chylothorax in a child with Noonan syndrome successfully treated with prednisone. DESIGN: Case report. SETTING: A pediatric cardiology referral center for the Rocky Mountain region. PATIENT: An 18-month-old girl with Noonan's syndrome, pulmonary stenosis, and hypertrophic cardiomyopathy who presented with spontaneous chylothorax. INTERVENTIONS: The child's chylothorax did not respond to thoracic duct ligation, tetracycline pleurodesis, and pleurectomy during a 2-month period. A low-fat diet was helpful but did not eliminate the problem. Prednisone was started orally at 1 mg/kg per dose twice daily and slowly tapered during 3 months. The chylothorax did not recur during 8 months of follow-up. CONCLUSIONS: Prednisone may be useful in the treatment of chylothorax in Noonan syndrome. A controlled clinical trial would be helpful but would be difficult in such a rare complication of an uncommon syndrome.

Chylothorax↗
PubMed1992

New methods for evaluating utilization management programs.

Blue Cross and Blue Shield of Massachusetts, Inc (BCBS), has developed two new methods for measuring the effect of utilization management (UM) in reducing unnecessary hospital use. The "program component" method measures the separate effect of preadmission review, concurrent review, and discharge planning. The "savable days" method produces a composite measure of the effectiveness of the program as a whole. The use of these two methods is illustrated with five years of utilization review data from the BCBS nongroup insurance product. The results can be used by operations managers and policymakers to measure the performance of individual UM components and the program as a whole, to establish goals and monitor program performance, to modify the program in response to changing utilization patterns, to assist in developing premiums, to establish risk-sharing agreements with employers or providers, and to demonstrate the effectiveness of the program for use in marketing.

Blue Cross Blue Shield Insurance Plans↗
PubMed1992

Cost-effectiveness of present programs for detection of asymptomatic hypertension in relation to the severity of hypertension and proteinuric hypertension.

Proteinuric hypertension is an important cause of maternal and perinatal mortality. Eclampsia cannot always be prevented. The likelihood of identifying a new case of proteinuric hypertension at any particular visit is very low using traditional antenatal care schedules, and care could be focused on women at higher risk.

Cost-Benefit Analysis↗
PubMed1992

Differential response of human thymus cells to CD2 antibodies: fragmentation of DNA of CD45RO+ and proliferation of CD45RO- subsets.

Human thymocytes bearing the CD45RO 'memory' cell phenotype do not proliferate in concanavalin A (Con A)-stimulated cultures and may be destined for intrathymic death. To determine whether this subset would exhibit characteristics of programmed cell death (apoptosis), we examined the integrity of the nuclear DNA by gel electrophoresis. DNA fragmentation was restricted to the CD45RO+ subset of human thymocytes following exposure to stimulating concentrations of anti-CD2 antibodies. Both CD45RO- and CD45RO+ subsets mobilized cytoplasmic Ca2+ following cell-surface CD2 ligation, but entry into the cell cycle and vigorous thymidine uptake were restricted to the CD45RO- subset. Our results provide a mechanism which may account for the failure of thymic CD45RO+ cells to respond to stimuli which elicit proliferation by the reciprocal CD45RA+ subset.

Antigens, CD↗
PubMed1992

A review of urea and creatinine kinetics in predicting CAPD outcome.

The adequacy of the peritoneal dialysis prescription is of great concern. Although the use of urea kinetics has become the standard in hemodialysis, its usefulness in peritoneal dialysis is unclear. It has been suggested that creatinine clearance may correlate with clinical outcome in CAPD but, as with urea kinetics, its predictive value is not established. The efficacy number (EN), which only requires a four hour exchange, was introduced as a simpler approach to creatinine kinetics. These three kinetic models were correlated to clinical outcome in 18 stable CAPD patients over a 12 month study period. The patients were divided into three groups: good (G), intermediate (I), and poor (P) based on uremic symptoms, mortality, hospital days, biochemical indices and the need for transfer to hemodialysis. Both forms of creatinine kinetics (weekly creatinine clearance, EN) were able to differentiate between the G, I, and P outcome groups (P < 0.05). The weekly uea Kt/V was able to differentiate between the G and P groups (P < 0.05) but not between the I and the other two outcome groups. Both urea and creatinine kinetics predict clinical outcome in CAPD. However, creatinine kinetics may be a more sensitive predictor. The efficacy number was just as sensitive as creatinine clearance in predicting clinical outcome yet simpler to gather the data for its calculation.

Creatinine↗
PubMed1991

Deprivation indices.

Explore the source record for details and available documents.

Health Care Rationing↗
PubMed1991

Increased airways reactivity after smoke inhalation.

13 fire victims who required treatment after smoke inhalation underwent lung function assessment within 3 days of injury and 3 months later. Initial airways hyperreactivity improved over this period, but FEV1 and airways specific conductance did not change significantly. There was a strong correlation between exposure carboxyhaemoglobin concentration (an indicator of smoke exposure) and initial airways specific conductance (r + 0.79; p = 0.006). Airways obstruction after smoke inhalation in house fires may be more common and more persistent than is generally recognised. Early lung function tests would allow the incidence of pulmonary complications after smoke inhalation and the potential benefits of early use of inhaled antiinflammatory drugs to be assessed.

Adult↗
PubMed1991

Identification and characterization of a protective immunodominant B cell epitope of pertactin (P.69) from Bordetella pertussis.

Epitopes defined by monoclonal antibodies (mAb) specific for the Bordetella pertussis outer membrane protein P.69 (pertactin) were mapped using a series of amino- and carboxy-terminal deletion mutants expressed in Escherichia coli. mAb were found to bind predominantly to a region of pertactin spanning a (Pro-Gln-Pro)5 repeat motif and one mAb was found to bind to another region spanning a (Gly-Gly-Xaa-Xaa-Pro)5 repeat motif. To localize further the mAb-binding sites, a panel of synthetic peptides, a series of 94 overlapping hexameric peptides, and a P.69 30-amino acid fusion to a hepatitis B core protein (HBcAg-69), were synthesized. This combined approach has identified the binding site for the mAb BBO5: Pro-Gly-Pro-Gln-Pro-Pro; mAb BBO7, E4A8 and E4D7: Ala-Pro-Gln-Pro-Pro-Ala-Gly-Arg; and mAb BPE3: Thr-Leu-Trp-Tyr-Ala-Glu-Ser-Asn-Ala-Leu-Ser-Lys-Arg. We have used a non-lethal murine respiratory model of B. pertussis infection to investigate the ability of a peptide containing the epitope of the mAb BBO5 to elicit protective immunity. Immunization of mice with the HBcAg-69 protein prevented growth of B. pertussis in the lungs compared to mice receiving HBcAg alone, and protection correlated with high titers of anti-P.69 antibodies.

Amino Acid Sequence↗
PubMed1991

Cognitive abilities and school performance of extremely low birth weight children and matched term control children at age 8 years: a regional study.

The intellectual, psychoeducational, and functional status of a regional cohort of extremely low birth weight (ELBW) survivors who weighed 501 to 1000 gm at birth (n = 143) and who were born between 1977 and 1981 was compared with that of control children born at term (n = 145) who were matched for gender, age, and social class. One hundred twenty-nine ELBW survivors (90%) were available; their mean birth weight was 839 +/- 124 gm and mean gestational age 27 +/- 2.1 weeks, and 48 of them weighed less than or equal to 800 gm at birth. Both ELBW and control groups were tested at a mean unadjusted age of 8 years; 113 of 129 ELBW children completed the full test battery, eight blind children had other tests, and eight were not testable. The mean Full Scale IQ (Wechsler Intelligence Scale for Children--Revised) was 91 +/- 16 for ELBW children and 104 +/- 12 for control children (p less than 0.0001). Between 8% and 12% of the ELBW group scored in the "abnormal" range (less than or equal to -2 SD) on the Wechsler IQ and subtests, compared with 1% to 2% of the control group. The ELBW group did less well on the reading, spelling, and mathematics tests (Wide Range Achievement Test--Revised less than or equal to -2 SD: ELBW = 20% to 28%; control = 3% to 10%). The motor performance of the ELBW group (Bruininks-Oseretsky Test of Motor Proficiency less than or equal to -2 SD: ELBW = 20%; control = 1%) and their visual-motor integration (Beery Developmental Test of Visual-Motor Integration less than or equal to -2 SD: ELBW = 21%; control = 6%) were also poorer. Exclusion of 19 ELBW children with neurologic impairments or an IQ less than or equal to 70 or both did not result in significant improvement in Wechsler or achievement measures. Approximately 15% of the ELBW cohort performed in the abnormal range on the Vineland Adaptive Behavior Scales, compared with none of the control group. Although approximately two thirds of the ELBW group were performing in the normal range on intellectual measures, comparison with the control group suggests that, as a group, ELBW children were significantly disadvantaged on every measure tested.

Achievement↗
PubMed1991

Effect of three sterilization techniques on finger pluggers.

The effects of different sterilization methods on the fatigue life of finger pluggers were investigated. Ninety finger pluggers for each of four sizes (A, B, C, and D) were subdivided into subgroups of 10. Each subgroup was subjected to 1, 8, or 15 cycles of steam autoclave, dry heat, or bead sterilization. Ten control pluggers for each size were not sterilized. After sterilization, experimental and control finger pluggers were subjected to cyclic bending until fracture. Only the A finger pluggers autoclaved for eight cycles had a significantly lower number of cycles to failure compared with that of the controls. Nine subgroups had significantly greater number of cycles before failure than did the control. Because all but one sterilized group had fatigue lifetimes statistically equal to or greater than nonsterilized controls, clinicians generally can use any of the three sterilization methods without fear of plugger failure.

Analysis of Variance↗
PubMed1991

Elevated common acute lymphoblastic leukemia antigen expression in pediatric immune thrombocytopenic purpura.

Bone marrow examination is often performed in thrombocytopenic children to distinguish immune thrombocytopenic purpura (ITP) from acute leukemia. We describe a patient with thrombocytopenia and 50% common acute lymphoblastic leukemia antigen (CALLA) positivity in his marrow who was subsequently shown to have ITP. CALLA (CD10) is a surface antigen found in early B-lymphocytes and is elevated in most cases of childhood acute lymphoblastic leukemia (ALL). This case prompted us to prospectively study the frequency of immature lymphocyte populations in children with ITP. Fourteen patients with acute ITP and five with other conditions were studied. The two groups were comparable with respect to age: ITP mean, 4.3 (range 0.3-15.5) years; control mean, 5.8 (0.6-13.8) years. The ITP group had a significantly higher percentage of CD10 positive bone marrow lymphocytes (p = 0.007). Five of the 10 patients younger than 4 years of age in the ITP group had CD10 levels of greater than 30%, which is in the leukemic range, whereas none of the control patients had a CD10 levels of greater than 17% (p = 0.003). There was good correlation between CD10 positivity and B4 positivity indicating that both of these markers arise from the same population of immature B-lymphocytes. None of the ITP patients who were older than 4 years had a CD10 level of greater than 30%. We conclude that it is common to have an increase in the proportion of immature lymphocytes in the marrow of young children with ITP. The cause of this increase in CD10 positive cells is unknown.(ABSTRACT TRUNCATED AT 250 WORDS)

Antigens, CD↗