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Biomedical subjects

C Adams

Publications and source records attributed to C Adams.

At least 55 records · Page 3Linked to original sources
PubMed1994

Primary hypothyroidism with intracranial hypertension and pituitary hyperplasia.

A 12-year-old girl presented with primary hypothyroidism, secondary pituitary hyperplasia, and intracranial hypertension. Cranial computed tomography revealed a sellar mass with suprasellar extension. She responded to medical treatment. Intracranial hypertension may be associated with primary hypothyroidism prior to thyroxine treatment. Because significant pituitary hyperplasia can be associated with primary hypothyroidism, it is vital to have endocrine investigation prior to consideration of surgical removal of an apparent pituitary tumor.

Cerebrospinal Fluid Pressure↗
PubMed1994

Autosomal recessive, fatal infantile hypertonic muscular dystrophy among Canadian Natives.

We describe eleven mid-western Canadian aboriginal infants with a unique, progressive muscle disorder. All except one had muscle biopsy and/or autopsy. The infants were normal newborns who rapidly developed rigidity of all skeletal muscles, with early, respiratory insufficiency. Death occurred before 18 months of age. Electromyography showed increased insertion activity and profuse fibrillation potentials; motor unit potentials and interference pattern are normal until late in the course. Pathologic features include progressive, granular to powdery Z-band transformation, myofibrillar loss, and muscle regeneration. SDS-gel electrophoresis of one muscle sample revealed increased 54kDa and reduced 80kDa protein fractions. This disease differs from other conditions with Z-band alterations because of continuous muscle activity and relentless clinical progression. The clinical features, elevated serum creatine kinase, electromyographic and muscle biopsy findings suggest a dystrophic process. The recognition of this condition as an autosomal recessive disorder allows appropriate genetic counselling.

Canada↗
PubMed1994

Genetic selection for mutations that impair the co-operative binding of lambda repressor.

Bacteriophage lambda repressor binds co-operatively to adjacent pairs of DNA target sites. A novel combination of positive genetic selections, involving two different operon fusions derived from P22 challenge phages, was used to isolate mutant lambda repressors that have lost the ability to bind co-operatively to tandem sites yet retain the ability to bind a strong, single site. These cb (co-operative binding) mutations result in 10 different amino acid changes, which define eight residues in the carboxyl-terminus of repressor. Because challenge phage derivatives may be applied to study essentially any specific protein-DNA interaction, analogous combinations of genetic selections may be used to explore the ways that a variety of proteins interact to assemble regulatory complexes.

Amino Acid Sequence↗
PubMed1994

International headache society criteria and childhood headache.

The objective of this study was to determine whether the intuitive clinical diagnosis of a headache type made by paediatric neurologists would also have fulfilled International Headache Society (IHS) criteria for that type. Clinical information was recorded on data sheets. The neurologists made clinical diagnoses without referring to a fixed set of criteria. An independent physician then used the information on the data sheets to classify the child's headache by IHS criteria. Complete data sheets were available for 72 children, aged between four and 18 years. The intuitive clinical diagnosis was completely concordant with the criterion diagnosis of the IHS in 61 per cent, partially concordant in 31 per cent and at complete variance in 8 per cent. These data suggest that the IHS criteria can be applied to a majority of children in a referral-based population such as this, but that minor revisions to the criteria are necessary to make them even more applicable to children.

Adolescent↗
PubMed1994

Inter-observer agreement in the diagnosis of childhood headache.

We prospectively assessed inter-observer agreement in the diagnosis of recurrent headaches in children. Clinical letters containing information on 40 children with headaches (age 4.3 to 17.8 years, median 10.4 years) were given to four Pediatric Neurologists. One or more headache types could be checked off on a data sheet that listed the main types recognized by the International Headache Society and an additional one, "combined migraine and tension-type headache". There were six combinational pairs of neurologists. The six pairs yielded 240 sets of diagnoses. Percentage agreement ranged from 45% to 78%, Kappa values from 0.20 to 0.59, and weighted Kappa from 0.19 to 0.52 within the six pairs. Agreement was 76% when both neurologists in a pair assigned single headache types and 4% when one or both neurologists diagnosed multiple types. The International Headache Society suggests that patients may have multiple types of headache and recommends that all types be classified. We suggest that the option of diagnosing more than one headache type from data in clinical letters may reduce inter-observer agreement.

Adolescent↗
PubMed1993

Problem solving styles of school nurses.

School nurses are challenged on a daily basis to solve complex problems and generate creative solutions to meet the health needs of children. This study focused on how school nurses go about solving problems in the delivery of school health services. The results showed that school nurses' problem-solving style allows them to act as "bridgers" within the educational environment and to promote collaboration among many types of school personnel.

Humans↗
PubMed1993

Serosurvey of some major zoonotic infections in children and teenagers in Bali, Indonesia.

One hundred and ninety serum samples, mainly from children and teenagers, from northeast Bali were tested for the presence of antibodies against five zoonotic agents: Brucella abortus, Coxiella burnetii, Toxoplasma gondii, Toxocara canis and Trichinella spiralis. All children were negative for brucellosis and Q fever. A high prevalence rate was found for toxocariasis (63.2%) and trichinosis (19.5%). Antibody prevalence against T. gondii was found to be rather low (3.1%). To our knowledge, this is the first evidence of toxoplasmosis, toxocariasis and trichinosis infection in humans on Bali. Eating habits and poor hygiene may explain the frequency of parasitic infestations in the children and teenagers in Bali.

Adolescent↗
PubMed1993

Accident prevention. Getting the message across on safety.

Child accident prevention is a key part of the health visitor's role. But faced with the demands of a large and busy caseload, health visitors may not be able to give the subject the priority it needs. Cheryll Adams describes a uniquely simple way to ensure that parents get the message about child safety.

Accident Prevention↗
PubMed1992

A comparative study of pH/activity profiles for the anaerobic H2O2 and alkyl hydroperoxide supported N demethylation of N methylaniline catalyzed by alkaline haematin and microsomal cytochrome P-450.

A comparative study of the effect of pH on haemin-mediated H2O2 and alkyl hydroperoxide-supported N-demethylation of N-methylaniline and the corresponding cytochrome P-450 mediated process has been carried out. This extends previous studies and provides quantitative evidence that the same active oxygen species are involved in both the enzymic and metalloporphyrin mediated processes. Furthermore, this evidence clearly indicates that the environment at the point of catalysis in the enzyme active site differs considerably from that of the bulk solution.

Anaerobiosis↗
PubMed1992

Comprehension problems in children with specific language impairment: literal and inferential meaning.

A group of 61 schoolchildren with specific language impairment (SLI) was compared with a control group on a comprehension task, in which the child was questioned about a story that had been presented either orally or as a series of pictures. Half the questions were literal, requiring the child to provide a detail that had been mentioned or shown explicitly in the story. The remainder required the child to make an inference about what had not been directly shown or stated. SLI children were impaired on this task, even after taking into account "comprehension age," as assessed on a multiple-choice test. However, the effects of mode of presentation and question type were similar for control and SLI groups. Children who fitted the clinical picture of semantic-pragmatic disorder had lower scores than other SLI children on this task. In addition, they were more prone to give answers that suggested they had not understood the question. However, as with the other SLI children, there was no indication that they had disproportionate difficulty with inferential questions. It is concluded that SLI children are impaired in constructing an integrated representation from a sequence of propositions, even when such propositions are presented nonverbally.

Child↗
PubMed1992

Flagellar microtubule dynamics in Chlamydomonas: cytochalasin D induces periods of microtubule shortening and elongation; and colchicine induces disassembly of the distal, but not proximal, half of the flagellum.

To study the mechanisms responsible for the regulation of flagellar length, we examined the effects of colchicine and Cytochalasin D (CD) on the growth and maintenance of Chlamydomonas flagella on motile wild type cells as well as on pf 18 cells, whose flagella lack the central microtubules and are immobile. CD had no effect on the regeneration of flagella after deflagellation but it induced fully assembled flagella to shorten at an average rate of 0.03 microns-min. Cells remained fully motile in CD and even stubby flagella continued to move, indicating that flagellar shortening did not selectively disrupt machinery necessary for motility. To observe the effects of the drug on individual cells, pf 18 cells were treated with CD and flagella on cells were monitored by direct observation over a 5-hour period. Flagella on control pf 18 cells maintained their initial lengths throughout the experiment but flagella on CD-treated cells exhibited periods of elongation, shortening, and regrowth suggestive of the dynamic behavior of cytoplasmic microtubules observed in vitro and in vitro. Cells behaved individually, with no two cells exhibiting the same flagellar behavior at any given time although both flagella on any single cell behaved identically. The rate of drug-induced flagellar shortening and elongation in pf 18 cells varied from 0.08 to 0.17 microns-min-1, with each event occurring over 10-60-min periods. Addition of colchicine to wild type and pf 18 cells induced flagella to shorten at an average rate of 0.06 microns-min-1 until the flagella reached an average of 73% of their initial length, after which they exhibited no further shortening or elongation. Cells treated with colchicine and CD exhibited nearly complete flagellar resorption, with little variation in flagellar length among cells. The effects of these drugs were reversible and flagella grew to normal stable lengths after drug removal. Taken together, these results show that the distal half to one-third of the Chlamydomonas flagellum is relatively unstable in the presence of colchicine but that the proximal half to two-thirds of the flagellum is stable to this drug. In contrast to colchicine, CD can induce nearly complete flagellar microtubule disassembly as well as flagellar assembly. Flagellar microtubules must, therefore, be inherently unstable, and flagellar length is stabilized by factors that are sensitive, either directly or indirectly, to the effects of CD.

Actins↗
PubMed1992

Mutant lambda repressors with increased operator affinities reveal new, specific protein-DNA contacts.

The binding specificities of four mutant lambda cI repressor proteins with increased affinities for operator DNA were examined. Two mutant repressors (Glu34----Lys and Glu83----Lys) have the same specificity of binding as wild-type repressor, whereas two (Gly48----Ser and Gly48----Asn) have new binding specificities. The Gly48----Asn mutant repressor recognizes lambda operators with changes at base pair 3 with a different order of affinity than wild-type repressor, suggesting that the side chain of Asn48 makes additional specific DNA contacts at or near this base pair. When paired with a change that disrupts the specific interaction of the amino-terminal arm of lambda repressor with DNA (Lys4----Gln), one change that increases the affinity of repressor (Gly48----Ser) suppresses the binding defect of the Lys4----Gln repressor, resulting in a double mutant repressor with a new binding specificity different than that of both its parents and of wild type. These results lend strong support to the model of direct recognition of the lambda operator by lambda repressor proposed from the crystal structure of the repressor/operator complex.

Bacteriophage lambda↗
PubMed1992

[Left ventricular dilatation after primary transmural anterior myocardial infarction. Influence of the percentage of akinesia on echocardiography].

The aim of this study was to determine whether the percentage of akinesia on echocardiography during the acute phase of transmural anterior myocardial infarction could predict secondary left ventricular dilatation. The study group comprised 24 patients (18 men and 6 women) with an average age of 59 years. The patients underwent two echocardiographic examinations, the first during the acute (< 72 hours) phase and the second, 6 months later. Ventricular volumes were calculated by the ellipse monoplane method in the apical 4 chamber view. The percentage of akinesia was defined as the ratio between the length of the akinetic segment and the left ventricular end diastolic perimeter in the apical 4 chamber view. An increase in end diastolic volume (83 +/- 25 vs 62 +/- 18 ml/m2; p < 0.01) and in end systolic volume (51 +/- 27 vs 34 +/- 11 ml/m2; p < 0.01) was observed 6 months after infarction without a significant change in ejection fractions (42 +/- 17% vs 44 +/- 10%). The percentage of akinesia in the acute phase was > 30% in 15 patients (Group I) and < 30% in 9 patients (Group II). The increase in ventricular volumes at 6 months after infarction was significant in Group I (p < 0.02) but not in Group II. At 6 months after infarction, the end systolic volumes were greater (60 +/- 27 vs 37 +/- 22 ml/m2, p < 0.5) and the ejection fractions were lower (35 +/- 13% vs 53 +/- 18%, p < 0.01) in Group I than in Group II.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

Superiority of end-diastolic volume and ejection fraction measurements over wedge pressures in evaluating cardiac function during aortic reconstruction.

Marked changes occur in cardiac function during aortic reconstruction. Numerous factors (primarily compliance changes) limit the currently used pressure-based pulmonary artery catheters' ability to reflect these changes accurately. A new pulmonary artery catheter was used in 26 patients undergoing aortic reconstruction (7 patients with abdominal aortic aneurysms and 19 with occlusive disease) that directly measures right ventricular (RV) volumes and ejection fractions. The extent of coronary artery disease (CAD) was evaluated before surgery, and the patients were divided into three classes. The greatest changes in cardiac function were noted immediately after aortic cross-clamping. Cardiac output significantly decreased in patients with mild or moderate CAD (p less than 0.01 and p less than 0.001) but not in patients with no CAD (p less than 0.5). This correlated well with RV end-diastolic volume (RV-EDV) and stroke volume (RV-SV) measurements in the groups with mild (p less than 0.05) and moderate CAD (p less than 0.01) but not in the group with no CAD (p greater than 0.5). Wedge pressure showed poor correlation, with no significant change noted in any group (p greater than 0.5). Measurements taken later in the procedure documented a significant trend toward baseline in mild and moderate groups. At the opening of the second limb of the graft, the compensated values (CO, RV-EDV, and RV-SV) did not change significantly in the groups with mild and no CAD (p greater than 0.2) but approached significance in the group with moderate CAD (p less than 0.08).(ABSTRACT TRUNCATED AT 250 WORDS)

Aorta, Abdominal↗
PubMed1991

Calvarial thinning in low grade intracerebral gliomas presenting with epilepsy.

Intracranial gliomas can erode or thin the skull. These changes are detectable on conventional radiographs but they appear to be rare. Only a few examples of the appearances on computed tomography (CT) are recorded in the literature. This paper describes the CT appearances of 11 cases. All of the patients presented with epilepsy. In most the tumours were small and indolent. Some went undetected or misdiagnosed for several years because of a lack of familiarity with the appearances.

Adolescent↗
PubMed1991

Qualitative age differences in memory for text: a life-span developmental perspective.

Qualitative differences in memory for text among 4 age groups (mean ages = 14.14, 17.55, 48.35, and 67.12 years) were examined in this study. Participants produced written recall and summary responses after presentation of a story and an essay. The response protocols were scored for their reproductive, elaborative, and metaphoric content. Age-group differences were observed in the quality of the responses. In general, the adolescent recall and summary responses were reproductive and text based, whereas the adult responses were more reconstructive and interpretive. Age-group differences were especially apparent in the story condition: The adolescents recalled and summarized the story's propositional content, whereas many of the adults recalled and summarized the story's psychological and metaphoric meanings as well. Individual difference variables accounted for much of the age-related variability in the essay but not in the story responses.

Adolescent↗