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Biomedical subjects

A K Grant

Publications and source records attributed to A K Grant.

At least 19 recordsLinked to original sources
PubMed2003

IPM-compatibility of foliar insecticides for citrus: indices derived from toxicity to beneficial insects from four orders.

A series of compounds representing four major pesticide groups were tested for toxicity to beneficial insects representing four different insect orders: Coleoptera (Coccinellidae), Hemiptera (Anthocoridae), Hymenoptera (Aphelinidae), and Neuroptera (Chrysopidae). These materials included organophosphates (methidathion, esfenvalerate and phosmet), carbamates (carbofuran, methomyl and carbaryl), pyrethroids (bifenthrin, fenpropathrin, zeta-cypermethrin, cyfluthrin and permethrin) and the oxadiazine indoxacarb. Toxicity to coccinellid and lacewing species was assessed by treating 1st instar larvae with the recommended field rate of commercial products, and two 10 fold dilutions of these materials, in topical spray applications. Adult Aphytis melinus Debach and 2nd instar Orius insidiosus (Say) were exposed to leaf residues of the same concentrations for 24 h. ANOVA performed on composite survival indices derived from these data resolved significant differences among materials with respect to their overall toxicity to beneficial insects. Cyfluthrin, fenpropathrin and zeta-cypermethrin all increased the developmental time of the lacewing and one or more coccinellid species for larvae that survived topical applications. Bifenthrin increased developmental time for two coccinellid species and decreased it in a third. Indoxacarb (Avaunt WG, DuPont Corp.) ranked highest overall for safety to beneficial insects, largely because of its low dermal toxicity to all species tested. Zeta-cypermethrin (Super Fury), FMC Corporation) received the second best safety rating, largely because of its low toxicity as a leaf residue to A. melinus and O. insidiosus. Phosmet (Imidan 70W, Gowan Co.) and methidathion (Supracide 25W, Gowan Co.) ranked high for safety to coccinellid species, but compounds currently recommended for use in citrus such as fenpropathrin (Danitol 2.4EC, Sumimoto Chem. Co.) and carbaryl (Sevin XLR EC, Rhone Poulenc Ag. Co.) ranked very low for IPM-compatibility based on their relatively high toxicity to all species tested.

Animals↗
PubMed2003

Intraguild predation among ladybeetles and a green lacewing: do the larval spines of Curinus coeruleus(Coleoptera: Coccinellidae) serve a defensive function?

Laboratory experiments examined interspecific interactions between larvae of three coccinellid species, Curinus coeruleus Mulsant (Chilocorinae), Harmonia axyridis Pallas and Olla v-nigrum (Mulsant) (Coccinellinae), and between these and larvae of the green lacewing, Chrysoperla rufilabris (Burmeister). Larvae of C. coeruleus, although defended on their dorsal surface with long spines, had the smallest mandibles, were the slowest-moving, and the least successful in interspecific larval combat. The long spines of third instar C. coeruleusappeared to reduce their palatability as food to H. axyridis and O. v-nigrum larvae in choice tests with dead larvae, but were not an effective defence against these species in Petri dish arenas. Larvae of O. v-nigrum had a smooth dorsal surface, were intermediate in terms of mandible size, but were the fastest moving, a trait that benefited their survival in intraguild combat. Larvae of H. axyridis were intermediate with respect to dorsal spines and speed of movement, but had the largest mandibles. This species was the most effective intraguild combatant among the coccinellids and the only one to successfully compete against C. rufilabris larvae of similar age. The speed, manoeuverability and long mandibles of C. rufilabris enabled them to impale coccinellid larvae at a relatively safe distance. The spines of C. coeruleus larvae impeded laterally oriented attacks by C. rufilabris, but did not provide sustained protection from repeated attacks. Success in these interactions appeared largely a function of offensive weaponry (mandible size and morphology) and speed of movement, although the role of dorsal spines as defensive structures was not ruled out. Rates of larval cannibalism were highest for C. rufilabris and largely mirrored the level of aggression observed in interspecific combat for each species.

Animals↗
PubMed1984

Clinical evaluation of the 14C-Triolein Breath Test: a critical analysis.

Twenty-two hospital patients without gastrointestinal symptoms and fourteen patients with clinically suspected fat malabsorption were studied using the 14C-Triolein Breath Test and three day fecal fat estimation. The 14C-Triolein Breath Test was 100% sensitive and 86% specific for fat malabsorption. Three day fecal fat estimations were 86% sensitive and 91% specific. These data confirm the high sensitivity and specificity obtained using the 14C-Triolein Breath Test. The speed and convenience of the 14C-Triolein Breath Test plus acceptable sensitivity and specificity make this a practical screening test to detect fat malabsorption.

Adult↗
PubMed1984

Colonic bicarbonate output as a test of disease activity in ulcerative colitis.

No available test objectively measures impairment of function of the inflamed colonic mucosa in ulcerative colitis. To study function we assessed rectal bicarbonate output by rectal dialysis in the presence of water and bacterial fatty acid (n-butyrate) in 21 controls, 18 patients with acute ulcerative colitis, 12 patients with ulcerative colitis in remission, and 12 patients with other forms of colitis. In acute ulcerative colitis, compared with controls, bicarbonate output and pH was reduced (p less than 0.001); stimulated bicarbonate output with bacterial fatty acid (incremental bicarbonate output) was reduced by 80% in acute ulcerative colitis (p less than 0.01). Results indicate that bicarbonate output is a useful and selective test of mucosal function in acute ulcerative colitis. A diminished incremental bicarbonate output with n-butyrate supports the view of inadequate oxidation of bacterial fatty acids in vivo by the mucosa in ulcerative colitis. Whether the test will prove to be an index of prognosis or will aid choice between medical or surgical therapy requires further study.

Acute Disease↗
PubMed1982

Gastrointestinal endoscopy: some perspectives.

Remarkable technological advances of fibreoptic endoscopy in the past two decades have produced important improvements in diagnosis and treatment of gastrointestinal and hepatobiliary disorders. These advances must be kept in perspective; continuing, critical assessment of their contribution to the management of patients is desirable. Endoscopy can have adverse effects on the total performance of departments of gastroenterology, on gastroenterology as a discipline, and even on the status of the medical profession in the community. Gastroenterologists need to show proficiency of performance and integrity of practice. Control may be achieved by certification delineation of privileges, peer review, public accountability, and realistic financial returns for procedures. Records of a department of gastroenterology indicate that some control may be achieved by insistence on a consultation before decision on endoscopy. This may be a desirable alternative to endoscopy on demand. Undue emphasis on technology runs some risk of destroying the proper practice of consultant medicine.

Endoscopy↗
PubMed1982

A comparison of diazepam and phenoperidine in premedication for upper gastrointestinal endoscopy: a randomized double blind controlled study.

A variety of agents are used as premedication for upper gastrointestinal endoscopy (U.G.E.). To our knowledge, no double blind studies have been performed to compare their value. In this study phenoperidine (2 mg i.v.) was compared with diazepam (t mg i.v.) in 200 consecutive patients undergoing elective U.G.E. The study was randomized and double blind in regard to both endoscopists and patients. All patients were given atropine (0.4 mg i.v.) and a throat spray with 2% amethocaine. Patients who needed supplemental medication were given diazepam and excluded from final analysis. A graded questionnaire was recorded by endoscopists and patients after U.G.E., and a further anonymous questionnaire was returned by patients four days later. Statistical analysis revealed that phenoperidine was superior at facilitating intubation and providing more relaxation as judged by the endoscopist. Patient questionnaires, four days after U.G.E., indicated less distress during intubation and examination with phenoperidine. Nausea, vomiting, amnesia and phlebitis were uncommon after either phenoperidine or diazepam.

Clinical Trials as Topic↗
PubMed1981

The effect preloads of amino acid on shortterm satiety.

The effect of a preload of an amino acid preparation on food intake in man was assessed in eight subjects. Each subject was given a small dose of amino acids or placebo 1/2 h before being presented with a meal. This was done in a blind, randomized fashion on five occasions for each preparation to each subject. The mean food intake of the subjects when receiving the amino acid preparation was 10% (p less than 0.01) less than the intake when receiving the placebo. When the subjects were grouped according to their variation from ideal weight, a 22.5% reduction in food intake was observed in group I (n = 4) who were greater than 5% above the ideal weight for height ratio (p less than 0.001). A 1.75% increase (NS) was seen in group II (n = 4) whose weight was within 5% of their ideal weight. These results demonstrate a modulation of satiety by small caloric doses of amino acids in overweight subjects.

Amino Acids↗
PubMed1981

A problem of management in Whipple's disease.

A patient with Whipple's disease did not respond to appropriate antibiotic treatment. A therapeutic response was obtained by a combination of tetracycline and prednisolone.

Drug Therapy, Combination↗
PubMed1980

Thyroid, renal, and hepatic function tests following cholecystography with high-dose contrast agents.

Serum biochemical tests were observed for about three weeks following oral cholecystography with fractionated high doses (6 g) of iopanoic acid (Telepaque) or sodium ipodate (Biloptin) in 24 and 29 patients, respectively. Both agents produced similar effects. No significant changes were seen in renal or hepatic function except for a mild increase in bilirubin on day 22. Serum urate decreased 10% on day 4, but the change was not significant. On days 4 and 11, there were significant increases in thyroid-stimulating hormone, thyroxine and free thyroxine index, and a moderate fall in triiodothyronine. Reverse triiodothyronine increased sharply on day 4. The pattern of changes observed suggests that these contrasts interfere with the extrathyroidal deiodination of iodothyronines. The temporary rise in thyroxine and free thyroxine index exceeded reference ranges in about half of all subjects, but they remained clinically euthyroid. Thyroid function tests should be interpreted with caution within three weeks of cholecystography.

Adult↗
PubMed1980

Fractionated dose cholecystography: a comparison between iopanoic acid and sodium ipodate.

Two randomised groups of 100 subjects each, undergoing oral cholecystography, were given either a 6 g fractionated dose of iopanoic acid (Telepaque) or sodium ipodate (Biloptin) to determine the relative merits of this dose schedule. Exclusions to the study were pregnancy and iodine sensitivity. Calculi or abnormal gallbladder opacification were present in 45% of subjects. Both agents were equally effective in demonstrating abnormalities, although bile duct visualisation was better using iopanoic acid (P less than 0.05). Of 46 subjects with abnormal cholecystograms subsequently undergoing surgery, all had the diagnosis confirmed. Side effects occurred in 63% of all subjects, being twice as common in those taking iopanoic acid (P less than 0.01). Sodium ipodate in a large fractionated dose is favoured because of the lower occurrence of side effects without loss of diagnostic accuracy.

Cholecystography↗
PubMed1979

Iron deficiency anaemia--a prospective study.

A prospective study was performed over 15 months to determine the cause of iron deficiency in adult males and postmenopausal females attending a general hospital. The laboratory computer identified all subjects with a haemoglobin less than 10.6 g/dl and a mean corpuscular volume less than 86 fl. Patients becoming anaemic after trauma or recent surgery were excluded. The iron status of each patient was assessed by serum iron studies, serum ferritin or sternal marrow aspiration. Reduced red cell indices and blood film morphology were not diagnostic of iron deficiency. Of 215 patients assessed, about half (103) were found to be iron replete. This group had a variety of disorders--malignancy, chronic inflammation, chronic renal and non-malignant haematological diseases. The other group of 104 patients satisfied criteria for iron deficiency, and 100 of these were investigated further. The cause of iron deficiency was found in all but three subjects. Inadequate dietary intake was a contributing factor in over half of the patients and 40 regularly took salicylates. Investigation defined a source of chronic gastrointestinal blood loss in most instances.

Adult↗
PubMed1978

The Mallory-Weiss lesion: a five-year experience.

A retrospective survey has been made of patients with the Mallory-Weiss lesion who presented with upper gastrointestinal tract bleeding during the period 1972 to 1976. The lesion was diagnosed endoscopically in 78 cases, representing 7.7% of the total number of patients admitted with upper gastrointestinal tract bleeding. Patients ranged in age from 18 to 86 years (mean 43 years). The male-female ratio was 3:1. A history of retching and vomiting clearly preceded the bleeding in 60 patients. Significant alcohol intake within 48 hours of bleeding was reported in 53% of patients. Other upper gastrointestinal tract conditions, or migraine, may have induced vomiting in some instances. Previously known Mallory-Weiss lesions were rare (two patients), but 21% of patients had well documented past upper gastrointestinal tract bleeding from other causes. The tears were situated at the cardio-oesophageal junction in 47% of patients and were entirely gastric in 30%; 23% were oesophageal. Blood replacement was required in 31 patients (40%), and 16 of these were transfused with five or more units. Of those patients requiring transfusion, half had other significant pathological lesions. The mean hospital stay was four days and prolonged stay in hospital was usually necessary only in the presence of other disease. In no instance was surgery required primarily to control bleeding from mucosal tears. This study suggests that the Mallory-Weiss lesion is a relatively common cause of upper gastrointestinal tract bleeding, but that it is usually a benign condition, unless it complicates some other disorder.

Adolescent↗