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Biomedical subjects

D Maxwell

Publications and source records attributed to D Maxwell.

At least 37 records · Page 2Linked to original sources
PubMed1992

Preoperative radiological evaluation of the liver by computerized tomographic portography in patients with hepatic tumors.

The main objective of preoperative imaging studies is to define as accurately as possible the number, size, location, and relationship of tumor masses in the liver to pertinent portal and hepatic venous vasculature. Computerized tomographic portography images hepatic veins and segmental portal vein branches and identifies the anatomical location of tumor nodules with excellent sensitivity and a low false-positive rate. The intraoperative correlation of computerized tomographic portography on 30 patients in the last 20 months at this institution shows a sensitivity of 88 per cent with a low rate of false-positivity. The ability to detect metastatic lesions in the liver by computerized tomographic portography diminishes when the lesions are noted to be less than 1 cm. The authors conclude that the preoperative interpretation of the computerized tomographic portogram provides valuable information not previously available to the surgeon operating on the liver.

Adult↗
PubMed1991

Effect of H1-receptor blockade on late cutaneous reactions to antigen: a double-blind, controlled study.

This study is of the effect of the blockade of histamine H1 receptors by a long-acting antihistamine on the immediate and late clinical response to antigen (Ag) and on the recruitment of eosinophils in the late-phase cutaneous reaction. Ten adult volunteers with late-phase reactions to the intradermal injection of either Dermatophagoides pteronyssinus or Phleum pratense (timothy) pollen performed a double-blind, crossover study. Each volunteer took astemizole, 10 mg, or identical placebo, daily for 2 weeks. Ag in the concentration that induced a late reaction in the screening visit was injected intradermally at the end of each drug period. The early reaction was measured serially for 30 minutes and the late reaction at 4 and 6 hours. Biopsies of the Ag and control sites were also performed at 6 hours. After a 6-week washout period, subjects then took the opposite medication for 2 weeks and returned for skin testing and biopsy. Skin testing demonstrated that astemizole inhibited the immediate response to both histamine and allergen but had no effect on the late response at 4 hours and at 6 hours. Biopsy specimens revealed no significant effect on eosinophil recruitment at 6 hours. We conclude that histamine H1-receptor blockade has no effect on the late cutaneous reaction to Ag.

Antigens↗
PubMed1991

Flecainide in the treatment of fetal tachycardias.

Fourteen mothers were treated with flecainide for fetal atrial tachycardias associated with intrauterine cardiac failure. Twelve of the 14 fetuses responded by conversion to sinus rhythm. One of the 12 fetuses subsequently died in utero. The remaining fetuses suffered no morbidity and were alive and well 3 months to 2 years after delivery. The two fetuses in whom atrial tachycardia did not convert with flecainide were successfully treated with digoxin. These results compare favourably with previous forms of antiarrhythmic treatment. After recent reports of the side effects of flecainide treatment, however, it has been advised that this drug should be confined to high risk patients and those with life threatening arrhythmias. The use of flecainide for fetal arrhythmias should be limited to patients with severe fetal hydrops and supraventricular tachycardias. It should not be the first drug of choice in atrial flutter.

Cardiac Output, Low↗
PubMed1991

Balloon dilatation of the aortic valve in the fetus: a report of two cases.

Because they had irreversible damage to the left ventricular myocardium none of 12 patients with critical aortic stenosis diagnosed prenatally survived after postnatal treatment. This experience prompted three attempts at intrauterine balloon dilatation of the aortic valve in two fetuses with this condition. On each attempt the balloon catheter was successfully delivered to the left ventricle. In the first fetus the aortic valve was not crossed and the fetus died the next day. In the second fetus the balloon was correctly positioned across the aortic valve and inflated in the valve ring. After delivery, a further balloon angioplasty was performed; this relieved the stenosis but the patient died five weeks later from persisting left ventricular dysfunction related to endocardial fibroelastosis. Balloon angioplasty is feasible in fetal life but the prognosis depends on the ability of the relief of stenosis to limit, prevent, or allow regression of left ventricular damage before delivery.

Adult↗
PubMed1989

Visualization of fetal intra-abdominal organs in second-trimester severe oligohydramnios by intraperitoneal infusion.

Fetal intraperitoneal infusion of saline was performed in two patients with severe oligohydramnios at 24 and 25 weeks' gestation in order to enhance visualization of intra-abdominal organs. Renal agenesis was easily diagnosed. The technique can be considered as an alternative to artificial instillation of amniotic fluid in the differential diagnosis of conditions associated with severe oligohydramnios.

Abdomen↗
PubMed1988

Chorionic villus sampling in a high-risk population--4 years' experience.

Between August 1982 and July 1986 a total of 163 pregnancies in 136 patients with a high genetic risk have had prenatal diagnosis by chorionic villus sampling. Villi were not obtained in five pregnancies (two of which subsequently miscarried), and 11 fetal losses followed successful sampling (four in pregnancies in which the fetus was shown to be affected). The rate of fetal loss fell with increasing experience of the team. Three sets of twins were all sampled successfully.

Abortion, Spontaneous↗
PubMed1987

Laryngeal manifestations of drug induced lupus.

Respiratory stridor and hoarseness were the predominant presenting symptoms in a 63-year-old woman with an hydralazine induced lupus syndrome. Laryngeal tomograms and direct laryngoscopy were consistent with cricoarytenoid arthritis. Proteinuria, anemia, arthritis, and leukocytoclastic vasculitis, as well as the laryngeal findings, all resolved after withdrawal of hydralazine. Laryngeal manifestations of systemic lupus erythematosus are reviewed.

Female↗
PubMed1986

Transabdominal chorionic villus sampling.

Transabdominal chorionic villus sampling, carried out with a fine-bore needle and cannula under ultrasound guidance, was as successful as transcervical aspiration but avoided the risks of bacterial contamination associated with the latter technique. The transabdominal procedure can be carried out under local anaesthesia, and multiple samples can be obtained, if necessary, through a single cannula.

Abdomen↗
PubMed1986

False positive localisation of indium-111 granulocytes in colonic carcinoma.

Indium-111 leucocyte scanning has been shown to be a highly accurate technique for detecting abscesses and assessing inflammatory bowel disease. We have encountered two cases of colonic carcinoma which presented as suspected inflammatory bowel disease and were found to localise 111In-labelled granulocytes. Histology revealed an acute inflammatory infiltrate in these tumours. These results indicate that 111In granulocyte scanning has limitations in the diagnosis of inflammatory bowel disease.

Aged↗
PubMed1985

Retinal vascular autoregulation in conditions of hyperoxia and hypoxia using the blue field entoptic phenomenon.

Autoregulation of retinal blood flow was studied in seven normal volunteers. The stimuli to autoregulation used were hyperoxia and hypoxia under controlled conditions of isocapnia. Macular blood flow was measured using the blue field entoptic phenomenon, and retinal artery and vein diameters were measured using a computerized digitising system. Results under conditions of isocapnic hypoxia showed a 38% average increase in blood flow and an increase in diameter of 8.2% and 7.4% in retinal arteries and veins, respectively. In hyperoxia, blood flow fell by an average of 36% and retinal artery and vein diameter decreased by 5.6% and 10%, respectively.

Adult↗
PubMed1985

A practical assessment of ultrasound-guided transcervical aspiration of chorionic villi and subsequent chromosomal analysis.

Aspiration biopsy of trophoblastic villi was performed on 56 patients immediately preceding suction termination of pregnancy, using a malleable metal cannula and ultrasound guidance. Villi were obtained from 47 patients (84%), with sampling success rising to 93% after experience. Immediate complications were noted in 14% of patients and correlated with placental positions situated furthest from the cervical canal. Karyotyping from cultured and/or direct preparations was attempted on the villus samples and was successful in 42. Clarity of the karyotypes obtained from direct preparations in this series was not found to be adequate for diagnostic purposes. A number of practical suggestions which facilitate chorion villus sampling are described.

Biopsy, Needle↗
PubMed1985

Measurement of autoregulation of retinal blood flow using the blue field entoptic phenomenon.

Autoregulation of retinal blood flow was studied in seven normal volunteers. The stimuli to autoregulation used were hyperoxia and hypoxia under controlled conditions of isocapnia. Macular blood flow was measured using the blue field entoptic phenomenon and retinal artery and vein diameters were measured using a computerised digitising system. Results under conditions of isocapnic hypoxia showed a 38 per cent average increase in blood flow and an increase in diameter of 8.2 per cent and 7.4 per cent in retinal arteries and veins respectively. In hyperoxia blood flow fell by an average of 36 per cent and retinal artery and vein diameter decreased by 5.6 per cent and 10 per cent respectively.

Adult↗