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Biomedical subjects

R Guthrie

Publications and source records attributed to R Guthrie.

At least 19 recordsLinked to original sources
PubMed1992

A multisite physician's office laboratory evaluation of an immunological method for the measurement of HbA1c.

OBJECTIVE: To evaluate the clinical performance of a new immunological HbA1c method in physicians' office laboratories. RESEARCH DESIGN AND METHODS: Three physicians' offices participated in the evaluations. The clinicians routinely use HbA1c test results to monitor their patients' long-term blood glucose control. Precision and interlaboratory variability were assessed using three levels of lyophilized controls. Correlation of the method's results to currently available laboratory methods was made. Comparison of finger-stick (capillary) results to venous EDTA whole blood results was made on 134 patients. Physician and laboratory personnel input was evaluated with regard to the clinical utility of the system. RESULTS: The CVW and CVB were a maximum of 4.5 and 4.4% for the immunoassay system on three levels of control materials at the three sites. Interlaboratory variability among the control means was found to be 4.9-5.4, 8.0-8.3, and 11.7-12.0% HbA1c. Correlation coefficients (r) ranged from 0.95 to 0.99. There was a positive bias by the DCA 2000 compared with the in-house method at site 1. Minimal negative biases were seen by the DCA 2000 with comparative methods used at sites 2 and 3. Median percentage differences with the comparative methods were 12, -1.4, and -5.6%. Comparison of capillary to venous sample results, from the DCA 2000, showed no clinically significant differences. Operator and physician feedback were positive with respect to technical ease in performance of the test and accuracy of results. CONCLUSIONS: Precision was acceptable and interlaboratory variability was low. The immunological method correlated well with manual ion-exchange and automated HPLC methods. The small sample size and good comparison between capillary and venous sample results make fingerstick sampling acceptable. The method provided immediate test results (within 9 min) to the clinicians.

Blood Specimen Collection↗
PubMed1991

Effects of two rescue doses of a synthetic surfactant on mortality rate and survival without bronchopulmonary dysplasia in 700- to 1350-gram infants with respiratory distress syndrome. The American Exosurf Neonatal Study Group I.

In a multicenter, double-blind, placebo-controlled rescue trial conducted at 21 American hospitals, two 5 ml/kg doses of a synthetic surfactant (Exosurf Neonatal) or air were administered to 419 infants weighing 700 to 1350 gm who had respiratory distress syndrome and an arterial/alveolar oxygen pressure ratio less than 0.22. The first dose was given between 2 and 24 hours of age; the second dose was given 12 hours later to those infants remaining on ventilatory support. Infants were stratified at entry by birth weight and gender. Among infants receiving synthetic surfactant, improvements in alveolar-arterial oxygen pressure gradient, arterial/alveolar oxygen pressure ratio, and oxygen and ventilator needs through 7 days of age were apparent. Death from respiratory distress syndrome was reduced by two thirds (21 vs 7; p = 0.007), and the overall neonatal mortality rate was reduced by half (50 vs 23; p = 0.001). Although there was no significant reduction in the incidence of bronchopulmonary dysplasia (39 vs 31; p = 0.107), the hypothesis that survival through 28 days without bronchopulmonary dysplasia would be enhanced by two rescue doses of synthetic surfactant was proved true (21% improvement, from 132 to 156 patients; p = 0.001). In addition, the incidence of pneumothorax was reduced by one third (62 vs 40; p = 0.022), and the incidence of pulmonary interstitial emphysema was reduced by half (102 vs 51; p = 0.001). The only side effect identified was an increase in the incidence of apnea (102 vs 134; p = 0.001). These findings indicate that rescue use of a synthetic surfactant can improve the morbidity and mortality rates for premature infants with respiratory distress syndrome.

Bronchopulmonary Dysplasia↗
PubMed1990

Isocratic reverse-phase liquid chromatography assay for amino acid metabolic disorders using eluates of dried blood spots.

A high-performance liquid chromatographic method for the simultaneous determination of the amino acids methionine, valine, tryptophan, phenylalanine, isoleucine, and leucine extracted from dried blood spots used in neonatal screening is described. The amino acids are eluted from a 3-mm filter paper disc of dried blood with an absolute ethanol:norleucine internal standard solution (1.5:1, v/v), derivatized with o-phthalaldehyde prior to injection, and separated on a C-18 reverse-phase column with subsequent fluorescent detection. The analysis time is under 9 min at the described sample dilution and the assay is linear from 15 to 300 mumols/liter for five of the amino acids and from 15 to 500 mumols/liter for valine. The interrun coefficients of variation are less than 10% (except for tryptophan) and the analytical recoveries exceed 85%. Results from patient samples correlate well with those from a Waters Pico-Tag amino acid analysis system and no apparent interferences were encountered. The rapid analysis time and the specificity of the assay will facilitate the presumptive diagnosis of the inherited amino acidopathies phenylketonuria, maple syrup urine disease, and homocystinuria/methioninemia as well as monitoring blood levels of diagnosed patients.

Amino Acid Metabolism, Inborn Errors↗
PubMed1989

Transient neonatal tyrosinaemia.

Children who had presented with transient neonatal tyrosinaemia (TNT) were compared with a group of unaffected controls at 7-9 years of age. A comprehensive psychometric assessment revealed significant differences between the groups in adaptive behaviour, psycholinguistic abilities, and speed of learning. In nearly all components of the tests used, higher levels of TNT were associated with lower levels of performance. This study demonstrates that TNT, a condition commonly regarded as benign in the short term, has long-term effects which may be detrimental to the child in school.

Adaptation, Psychological↗
PubMed1989

Erythrocyte protoporphyrin screening for lead poisoning in Bedouin children. A study from Kuwait.

Screening for lead poisoning can be performed by measuring either blood lead (PbB) or a haematological indicator such as erythrocyte protoporphyrin (EP). We have screened 902 infants and children aged from 3 months to 5 years amongst those attending three primary health care centres in AI Jahra governorate of Kuwait. Blood specimens were collected by finger prick on Guthrie filter paper and the dried blood samples were mailed to the Central Laboratory of the Children's Hospital, Buffalo, USA. One hundred and eighty-four (20 per cent) had an elevated EP (greater than 50 micrograms/dl). Of those 11 had values above 159 micrograms/dl; 140 children were further tested for blood lead levels (PbB) haemoglobin, mean cell volumes, and percentage of transferrin saturation; 41 had blood lead levels greater than 25 micrograms/dl which is the current definition of elevated blood lead levels. Two children (2 per cent) were in Class IV, 17 (15 per cent) and 16 (14 per cent) were in Class II and Class III, respectively. There was a significant correlation between EP and PbB (r = 0.686; P = less than 0.001). Of 72 children with elevated EP and normal PbB, 32 were anaemic (Hb less than 11 g/dl) and 20 had iron deficiency. The role of tribal practices using lead contaminated preparations and their contribution to elevated blood lead levels is discussed.

Biomarkers↗
PubMed1989

Osteomyelitis of the symphysis pubis: a complication of cardiac catheterisation.

An elderly female experienced the onset of right femoral pain shortly after undergoing cardiac catheterisation. Her condition was later found to be Pseudomonas osteomyelitis of the symphysis pubis. The patient did not have any of the usual risk factors for Pseudomonas osteomyelitis, ie, intravenous drug abuse, contiguous surgery or trauma. The probable mechanism of bacteria seeding into a haematoma around the femoral artery and then spreading to the contiguous osseus structures is proposed for this unusual complication.

Aged↗
PubMed1988

Office evaluation of dementia. How to arrive at a clear diagnosis and choose appropriate therapy.

About half of patients presenting with dementia have Alzheimer's disease, which cannot be prevented or reversed. Treatment of these patients is aimed at improving their quality of life and helping their families provide supportive care. About 15% of patients with dementia can be successfully treated. A detailed patient history, thorough physical examination, and appropriate laboratory testing are important to identify the treatable causes of dementia, such as normal-pressure hydrocephalus, Korsakoff's psychosis, and drug toxicity.

Aged↗
PubMed1988

Insulin autoantibodies at diagnosis of insulin-dependent diabetes: effect on the antibody response to insulin treatment.

Insulin autoantibodies (IAA) are frequently found in newly diagnosed untreated insulin-dependent diabetics. We evaluated whether the insulin antibody response over the first year of treatment with insulin was different in individuals with IAA v those without IAA. One hundred five previously untreated type I diabetics were randomly assigned to treatment with either pure porcine or mixed bovine/porcine insulin. Twenty-one in each group had detectable IAA at diagnosis. Percent binding rose in all patients after commencing insulin therapy and was significantly greater in those with IAA at diagnosis irrespective of the type of insulin administered. The elevated binding in the IAA positive patients at all time points was equivalent to the binding that could be attributed to the insulin autoantibodies. Two different mechanisms could explain this greater insulin antibody binding during insulin therapy in the IAA positive patients. First, there may be summation of binding due to insulin autoantibodies and binding due to insulin antibodies formed in response to the exogenous insulin. Alternatively, the insulin antibodies formed in response to exogenous insulin could replace the IAA, with those individuals positive for IAA at diagnosis having a proportionately greater antibody response to injected insulin. Irrespective of the mechanism, patients with IAA at diagnosis develop higher insulin antibody measurements when subsequently treated with exogenous insulin.

Autoantibodies↗
PubMed1988

Erythromycin in acute pharyngitis: a comparison of efficacy and patient tolerance of two twice-daily preparations.

Two hundred sixty-five adult and adolescent patients with possible streptococcal pharyngitis were treated with either erythromycin ethylsuccinate or an enteric-coated erythromycin in a twice-daily dosage schedule. In patients with group A beta-hemolytic streptococcal infection, both preparations achieved a cure rate of 93%. Patients receiving the enteric-coated erythromycin reported significantly more gastrointestinal adverse effects than did the patients receiving erythromycin ethylsuccinate.

Acute Disease↗
PubMed1988

Prenatal lead exposure and its potential significance for developmental disabilities: a preliminary study of umbilical cord blood lead levels.

It has been reported that between 1976-1980 the mean blood lead level in American preschool children was 16 micrograms/dl. The Centers for Disease Control (CDC) recently set a blood level of 25 micrograms/dl as the highest acceptable level for children. However, current research findings have provided evidence that detrimental effects on development can occur when lead levels are below this acceptable value. In particular, recent work has shown a relationship between early (prenatal) exposure to lead and delayed cognitive development. Because the developing fetus is particularly vulnerable to insult, it is of critical importance to obtain information about the developmental effects of prenatal exposure to lead and about those factors that may influence this exposure. This report presents initial findings of an ongoing investigation pertaining to issues surrounding early lead exposure. To date umbilical cord blood samples have been measured in 802 infants born at Children's Hospital of Buffalo between November 1987 and April 1988. These infants' residence span approximately 50 townships with most residing in Buffalo proper. Approximately 60 percent of the infants had measurable cord blood lead levels in the range of 4 to 20 micrograms/dl.

Cognition Disorders↗
PubMed1988

The incidence of Legionella pneumophila as the cause of acute ambulatory lower respiratory tract infection.

Seventy-nine ambulatory patients with acute lower respiratory tract infection were evaluated for Legionella pneumophila by acute and convalescent antibody titers. None of the patients met the traditional criteria for the diagnosis of acute infection caused by Legionella pneumophila. Currently accepted criteria for diagnosing legionellosis by serologic means may or may not be applicable to mild respiratory tract infections.

Ambulatory Care Facilities↗