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Biomedical subjects

R D Adam

Publications and source records attributed to R D Adam.

44 records · Page 3Linked to original sources

Radionuclide transit studies in the detection of oesophageal dysmotility.

A scintigraphic method is described to measure the transit of a fluid bolus through the oesophagus. Transit times in 16 normal subjects ranged from five to 15 seconds and were highly reproducible. Prolonged transit times were observed in 16 of 19 patients with known oesophageal motility disorders, and in these patients inspection of the time activity curves frequently permitted an adynamic oesophagus to be distinguished from one showing excessive incoordinate contractions. The technique was then applied prospectively to 50 patients referred for oesophageal motility studies and a comparison made between the oesophageal transit measurements and the findings on conventional oesophageal manometry. There was agreement between these tests in 42 (84%) of the 50 patients. The measurement of oesophageal transit may be made quickly and safely, without causing discomfort to the patient, and it appears to be at least as sensitive as manometry in the detection of oesophageal motility disorders.

Adult↗

Semiquantitative cultures and routine tip cultures on umbilical catheters.

One hundred and fourteen umbilical catheters (79 arterial and 35 venous) were cultured with a semiquantitative technique. Twelve cultures were SQC positive with greater than or equal to 15 colonies, and all but two of these had greater than or equal to 100 colonies. Organisms usually considered to be pathogens were associated with SQC positive catheters, whereas organisms generally considered nonpathogens were associated with less than 15 colonies on SQC. Therefore SQC may help to differentiate between contamination and infection related to umbilical catheters. The one case with purulence at the cord base grew 100 colonies of Staphylococcus epidermidis on SQC. S. epidermidis showed a bimodal distribution in colony count and should be considered as a pathogen when high colony counts are present. Duration of catheterization was longer in SQC positive catheters. Empiric antibiotic use was associated with negative SQC. Further study is indicated in a newborn population with a lower rate to antibiotic use for correlation of SQC results with catheter-induced bacteremia and sepsis.

Anti-Bacterial Agents↗

Prolonged effect of nadolol on heart rate in hyperthyroidism.

There is extensive experience in the treatment of hyperthyroidism with beta-blockade. Because of the short half-life of propranolol the drug must be taken in divided doses. The effect of a single daily dose of a long-acting beta-blocking drug, nadolol, was investigated in 7 hyperthyroid patients. A satisfactory and prolonged reduction in heart rate was observed during continuous monitoring over a 24-hour period. Nadolol, therefore, is a possible alternative to propranolol in the treatment of hyperthyroidism with an advantage in the poorly-compliant patient.

Adolescent↗

Alcohol absorption, gastric emptying and a breathalyser.

1 The value of a portable breathlyser (Alcometer AE-M2) in the assessment of gastric emptying after alcohol ingestion was investigated by comparing breath and venous blood alcohol concentrations with simultaneous scintigraphic measurements of gastric emptying rate. 2 Alcohol absorption, as determined by the area under the venous blood alcohol concentration-time curve during the first 30 min, correlated with gastric emptying during the same period, implying dependence of the rate of alcohol absorption on gastric emptying rate. 3 There was no correlation between breath and venous alcohol concentrations during the first 15 min after alcohol ingestion, but a significant correlation was observed thereafter. 4 Breath alcohol measurements may be sufficient to detect gross alterations in gastric emptying but measurements of venous blood alcohol are likely to be more reliable.

Breath Tests↗

Intravenous N-acetylcystine: the treatment of choice for paracetamol poisoning.

One hundred cases of severe paracetamol poisoning were treated with intravenous N-acetylcysteine (acetyl-cysteine). There was virtually complete protection against liver damage in 40 patients treated within eight hours after ingestion (mean maximum serum alanine transaminase activity 27 IU/1). Only one out of 62 patients treated within 10 hours developed severe liver damage compared with 33 out of 57 patients (58%) studied retrospectively who received supportive treatment alone. Early treatment and acetylcysteine also prevented renal impairment and death. The critical ingestion-treatment interval for complete protection against severe liver damage was eight hours. Efficacy diminished progressively thereafter, and treatment after 15 hours was completely ineffective. Intravenous acetylcysteine was more effective than cysteamine and methionine and noticeably free of adverse effects. It is the treatment of choice for paracetamol poisoning.

Acetaminophen↗

Clinical and metabolic features of overdosage with Amesec.

A 23-year-old woman ingested 2g. amylobarbitone, 10.4g. aminophylline and 2g. ephedrine. She was deeply unconscious, hypothermic, and went on to have supraventricular and ventricular dysrhythmias, convulsions and haematemesis. During the last convulsion she aspirated vomitus and died. The peak plasma concentration of amylobarbitone was 19mg. per l. and those of ephedrine and theophylline were 13 times higher than accepted therapeutic levels. During the course of the poisoning marked hypokalaemia (1.8mmol./l.) and hyperinsulinaemia (greater than 240mU./l.) were found in conjunction with mild hyperglycaemia (9.6mmol./l.) and elevation of free fatty acid levels (1860mumol./l.). The mechanism of these changes is discussed.

Adult↗

The effect of the acute administration of tolbutamide on left ventricular function in insulin-dependent diabetics.

Despite better control of diabetic patients with morbidity and mortality from heart disease is significantly higher than in non-diabetics. While this may be a result of premature atherosclerosis or primary diabetic cardiopathy, the possibility of oral hypoglycemic agents have adverse cardiac effects must be considered. Using nuclear angiography the effect of the acute administration of 1 g tolbutamide on left ventricular ejection fraction (EF) in a group of 10 Type-1 diabetics was investigated. There was no difference in the response of the EF when compared to the response in 10 diabetic controls given i.v. saline. While i.v. tolbutamide may have adverse cardiac effects when administered to animals or in vitro this does not necessarily apply to human diabetics.

Adult↗

Analysis of a repeat-containing family of Giardia lamblia variant-specific surface protein genes: diversity through gene duplication and divergence.

Giardia lamblia trophozoites express on their surfaces one of a set of cysteine-rich antigenically variant proteins, called variant-specific surface proteins, which comprise the majority of proteins detected by surface labeling. While these VSP proteins may be immunodominant proteins important in the host immune response to G. lamblia, the ability to switch expression from one VSP to another may provide a means for the trophozoites to avoid the host immune response. The first VSP characterized, VSPA6 (from the A6 clone of the WB isolate, originally termed CRP170), contains 18-23 copies of a 65 amino acid repeat. We have now used the repeat as a probe to isolate from a WBA6 genomic library two genes related to vspA6 (called vspA6-S1, vspA6-S2). Sequence analysis of the vspA6-S1 gene revealed nearly two complete copies of the 195 bp repeat and substantial nucleotide and translated amino acid similarity in the coding regions 5' and 3' to the repeats. The vspA6-S2 gene, while still related, showed greater divergence from vspA6 than vspA6-S1 in the nonrepeat coding region and contained nearly four copies of a 201 bp repeat that was 75% identical to the 195 bp vspA6 repeat. These results suggest that gene duplication followed by divergence has played a key role in the generation of the vsp gene repertoire.

Amino Acid Sequence↗