Search PubMed⌕ Search

Biomedical subjects

R E Smith

Publications and source records attributed to R E Smith.

At least 235 records · Page 13Linked to original sources

Cloning and expression of the major inner capsid protein of SA-11 simian rotavirus in Escherichia coli.

The major inner capsid protein (VP6) of SA-11 simian rotavirus has been expressed in Escherichia coli using a cloned cDNA derived from SA-11 double-stranded RNA segment 6. The cloned gene was fused to the N-terminal coding sequence of lacZ resulting in the synthesis of a 44-kDa protein. Several smaller polypeptides were also observed, resulting predominantly from transcription and translation within the gene 6 coding sequence. The recombinant VP6 proved to be antigenic by immunoblot analysis using polyclonal serum against SA-11 rotavirus and by Western-blot analysis using monospecific serum derived from purified viral VP6.

Animals↗

Delayed-type hypersensitivity test for assessing tick-immune status of cattle in Zambia.

Delayed-type hypersensitivity skin reactions were used to assess the tick resistance status of Tonga calves in Zambia. The antigen used in the tests was a homogenate of unfed nymphal Rhipicephalus appendiculatus which had been shown to give protective immunity in guinea pigs to adult female R appendiculatus. There was a significant negative correlation between the intensity of the reactions and the total number of ticks (Amblyomma variegatum, R appendiculatus, Hyalomma truncatum, Boophilus decoloratus and Rhipicephalus species) on the animals.

Animals↗

Bacterial corneoscleritis complicating pterygium excision.

Pterygium excision was complicated by bacterial corneoscleritis and endophthalmitis in two patients, one who had received postoperative beta irradiation and the other topical thiotepa. These complications followed surgery by two and six weeks. Causative organisms were Streptococcus pneumoniae and Pseudomonas aeruginosa, respectively. Despite aggressive therapy, visual outcome was poor in both cases. These cases demonstrate that, although infrequent, complications of pterygium excision can be destructive and visually disabling.

Adult↗

Comparison of intravenous infusions of iloprost and oral nifedipine in treatment of Raynaud's phenomenon in patients with systemic sclerosis: a double blind randomised study.

OBJECTIVE: To compare the long term effects of short term intravenous infusions of iloprost with those of oral nifedipine in patients with Raynaud's phenomenon associated with systemic sclerosis. DESIGN: Double blind, placebo controlled, randomised group comparison. SETTING: Dermatology outpatient clinic. PATIENTS: Twenty three patients with Raynaud's phenomenon associated with well documented systemic sclerosis (American Rheumatism Association criteria) and with typical abnormalities in fingernail folds on capillaroscopy. INTERVENTIONS: Twelve patients were randomised to receive intravenous infusions of iloprost starting at 0.5 ng/kg/min and increased by 0.5 ng/kg/min every 15 minutes to a maximum of 2.0 ng/kg/min for eight hours on three consecutive days with a further single infusion at week 8. Placebo capsules were given concurrently. Eleven patients were randomised to receive nifedipine, starting at 30 mg daily and increased to 60 mg daily after four weeks for another 12 weeks. Infusions of placebo were given in the same manner as the infusions of iloprost. One patient from each group withdrew because of social reasons and three patients receiving nifedipine withdrew because of side effects. END POINT: Reduction in number, duration, and severity of attacks of Raynaud's phenomenon, reduction in number of digital lesions, increase in digital blood flow. MEASUREMENTS AND MAIN RESULTS: Measurements were taken at 0, 4, 8, 12, and 16 weeks. Both regimens produced a reduction in the number, duration, and severity of attacks of Raynaud's phenomenon. The mean (SE) number of digital lesions was reduced with iloprost (from 3.5 (1.6) to 0.6 (0.3] and with nifedipine (from 4.3 (0.8) to 1.4 (0.5] after 16 weeks. Hand temperature and digital and microcirculatory blood flow were increased with iloprost but not with nifedipine. CONCLUSION: Both iloprost and nifedipine are beneficial in the treatment of Raynaud's phenomenon. With nifedipine, however, side effects are common. Short term infusions of iloprost provide longlasting relief of symptoms, and side effects occur only during the infusions and are dose dependent.

Administration, Oral↗

Persistent viral DNA synthesis associated with an avian osteopetrosis-inducing virus.

Bone and red blood cell DNA was obtained from MAV-2(O) infected, osteopetrotic chickens and analyzed for the presence of integrated and unintegrated viral DNA. Results indicate that unintegrated MAV-2(O) DNA did not appear until after osteopetrotic lesions were well established. These observations lead us to conclude that, unlike some retroviral diseases, unintegrated viral DNA may not play a significant role in the pathogenesis of MAV-2(O) osteopetrosis. In addition, there was no evidence of a clonally derived tumor in the bone.

Animals↗

The effect of radiation therapy on von Willebrand factor in patients with angiosarcoma.

Radiation damages endothelial cells (EC) of malignant and normal tissues. Shortly after radiation injury platelet thrombi cause small vessel obstruction. Radiation doses of 20 Gy or higher release von Willebrand factor (VWF) from cultured human umbilical vein EC. Angiosarcoma (AS) is a vascular tumor with abnormal appearing EC which have detectable cytoplasmic VWF. We examined the effect of radiation therapy on VWF in three patients with AS. Each patient's malignant tissue was demonstrated to have cytoplasmic VWF present. Venous blood samples were drawn immediately before and at weekly intervals during treatment. Patient 1 received 80 Gy over 6 weeks and had no alterations in the VWF. Patient 2 received 64 Gy over 6 weeks and was noted to have loss of the high molecular weight multimers of VWF without loss of FVIII:C, VW: RIST, or von Willebrand antigen activity (VW:Ag). Patient 3 was treated with 64.4 Gy over 9 weeks and had a disproportionate increase of the VW: Ag and VW: RIST to FVIII: C. This returned to normal after completion of therapy. These changes were minimal and might be explained by either limited local release or no increased release of VWF from the irradiated tissue. The minimally abnormal multimeric pattern in patient 2 may be due to the release of an abnormal VWF in normal amounts or small amounts of proteolysis. The alteration in the VW: RIST and VW: Ag to FVIII: C ratio can be explained by activated coagulation secondary to radiation injury.

Aged↗

Determination of inositol phosphates and other anions in rat brain.

Anion chromatography methods have been developed to determine the concentrations of inositol phosphates and other water-soluble metabolites in rat brain. The cerebral cortex, hippocampus, and striatum were analyzed by chemically suppressed conductivity detection. Animals were sacrificed by directed microwave irradiation for more accurate estimations of in vivo concentrations. The effects of different sample preparation methods are compared. Trichloroacetic acid, formic acid, and perchloric acid extraction result in lower recoveries of phosphocreatine and other anions than does homogenization with water followed by chloroform-methanol extraction. The effects of postdecapitative ischemia on metabolite concentrations are determined. These methods will be used to study the effects of pharmacological agents on inositol phosphates and should be broadly applicable to the analysis of a variety of biological systems.

Animals↗

Reflex sympathetic dystrophy (algoneurodystrophy): temperature studies in the upper limb.

The temperature response of the hands to mild cold stress (20 degrees C for one minute) has been measured in 20 normal subjects, 20 patients with reflex sympathetic dystrophy (RSD) and 10 patients with chronic upper limb pain (CULP) of uncertain origin. The results of RSD and CULP groups were significantly (p less than 0.05) different from normal but were indistinguishable. For each patient, 11 variables obtained from the thermal stress test were compared with the normal range. Ten of the RSD group and seven of the CULP group had four or more abnormal variables and were considered to have a thermoregulatory abnormality. The thermal stress test is useful in the objective assessment of RSD. It is non-invasive, patient acceptable and reproducible.

Adult↗

Effects of 13-cis-retinoic acid on the hamster meibomian gland.

Systemic administration of 13-cis-retinoic acid caused a reduction of acinar tissue in the hamster meibomian gland. Histologic examination of treated meibomian gland tissue revealed a thickening of gland ductal epithelium and a decrease in the numbers of mature lipid-laden acinar cells. Morphometric analysis showed a reduction of up to 75% in mean volume of meibomian acinar tissue from animals fed a high dose of 13-cis-retinoic acid. Clinical observations in these animals included alopecia and weight loss. Ocular complications included crusting of the eyelid margin and the external surface of the lid and erythema of the conjunctiva. The model supports previous observations by the authors that systemic 13-cis-retinoic acid affects meibomian gland structure in a laboratory animal. The ocular side effects described in this model suggest that future functional studies may yield important insights into the complex relationship between meibomian gland morphology and function, and events on the ocular surface.

Animals↗

Myocardial abscess and sternal osteomyelitis following myocardial infarction and resuscitation.

A 58 year old man presented with an anterior myocardial infarction requiring repeated resuscitation. He had impaired glucose tolerance. He died five weeks later and post-mortem examination revealed a myocardial abscess and sternal osteomyelitis due to Staphylococcus aureus. These had not been apparent clinically. The possible aetiology and difficulties in diagnosis are discussed.

Abscess↗