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C J Randall

Publications and source records attributed to C J Randall.

At least 19 recordsLinked to original sources
PubMed1992

Independent pathways regulate the cytosolic [Ca2+] initial transient and subsequent oscillations in individual cultured arterial smooth muscle cells responding to extracellular ATP.

Stimulation with extracellular ATP causes a rapid initial transient rise followed by asynchronous periodic oscillations in cytosolic calcium ion activity ([Ca2+]i) in individual aortic smooth muscle cells in either HEPES-buffered or HCO3(-)-buffered saline. The dose at which one-half of the cells display an initial rise in cytosolic calcium is 0.11 microM ATP in the presence of external Ca2+ and 0.88 microM ATP in the absence of external Ca2+; the corresponding value for oscillations in the presence of external Ca2+ is 2.6 microM ATP. While the initial transient displays rapid desensitization, the oscillations persist for greater than 30 min in the continuous presence of ATP. The presence of the agonist ATP is also absolutely required for the maintenance of the oscillations, presumably to provide continuous activation of P2 purinoceptors. The average frequency of oscillation is approximately 0.9 min-1. The frequency depends only slightly on the concentration of ATP, and oscillations do not collapse into a prolonged elevated [Ca2+]i at high concentrations of ATP. Both Ca2+ influx and release from internal stores participate in the initial transient. Oscillations are not produced in the absence of external Ca2+ but are initiated upon the addition of external Ca2+ in the continued presence of ATP. Oscillations in progress are abolished by the removal of extracellular Ca2+ with one additional peak occurring after the Ca2+ removal. These data suggest that extracellular Ca2+ influx is required for the maintenance of the posttransient oscillations, presumably to provide the Ca2+ necessary for refilling intracellular Ca2+ pools that are the source of the oscillating [Ca2+]i. The Ca2+ influx is not regulated by voltage-gated Ca2+ channels. The data in this report are consistent with the view that the initial transient has contributions from two receptor-mediated pathways, and the oscillations are controlled either by a mechanism separate from the ones that control the initial transient or by steps whose control diverges before the point of desensitization.

Actins↗
PubMed1989

Observations on swollen head syndrome in broiler and broiler breeder chickens.

Chickens on 14 broiler breeder farms were examined at various times throughout their laying cycle. Antibodies to the turkey rhinotracheitis virus were common although they were not always accompanied by clinical signs of the swollen head syndrome. Ninety-nine broiler flocks were tested of which only 20 were serologically positive to the virus. Some of these infections were subclinical. On nine farms where swollen head syndrome occurred several successive flocks were sampled; the syndrome occurred intermittently.

Animals↗
PubMed1989

Dysphagia after fast neutron therapy to the head and neck.

Nine patients presenting with dysphagia following successful treatment for head and neck cancer with neutron radiotherapy are reviewed. Combined clinical and videofluoroscopic investigation is used to analyse their deficits and provide indications for management. All patients show impairment of both the oral and pharyngeal phases of the swallow, with the exception of one subject who shows signs of focal neurological damage. It is suggested that fibrosis is the underlying cause of dysphagia in the remainder.

Adult↗
PubMed1988

Avulsion of the patellar ligament in osteopenic laying fowl.

Metabolic bone disease in laying fowl has been associated with mortality and decreases in egg production. Recently there appears to have been an increasing incidence of the disease and the affected flocks have shown a variable response to dietary treatments. In 14 birds from eight recent submissions, avulsion of the patellar ligament together with part of its bony insertion was observed. Because the skeletons of the affected birds were judged from radiographs to be osteopenic, the lesions were probably pathological fractures. Histopathological studies of four birds revealed osteoporosis affecting cancellous bone trabeculae; in one bird, however, the medullary bone trabeculae were largely composed of unmineralized or poorly mineralised matrix, a finding which can be interpreted as osteomalacia.

Animals↗
PubMed1987

Physical-chemical interaction of heparin and human plasma low-density lipoproteins.

This study characterizes the physical-chemical interactions of heparin with human plasma low-density lipoproteins (LDL). A high reactive heparin (HRH) specific for the surface determinants of LDL was isolated by chromatography of commercial bovine lung heparin on LDL immobilized to AffiGel-10. HRH was derivatized with fluoresceinamine and repurified by affinity chromatography, and its interaction with LDL in solution was monitored by steady-state fluorescence polarization. Binding of LDL to fluoresceinamine-labeled HRH (FL . HRH) was saturable, reversible, and specific; HRH stoichiometrically displaced FL . HRH from the soluble complex, and acetylation of lysine residues on LDL blocked heparin binding. Titration of FL.HRH with excess LDL yielded soluble complexes with two LDL molecules per heparin chain (Mr 13,000) characterized by an apparent Kd of 1 microM. Titration of LDL with excess HRH resulted in two classes of heparin binding with two and five heparin molecules bound per LDL and apparent Kd values of 1 and 10 microM, respectively. At physiological pH and ionic strength, the soluble HRH-LDL complexes were maximally precipitated with 20-50 mM Ca2+. Insoluble complexes contained 2-10 HRH molecules per LDL with the final product stoichiometry dependent on the ratio of the reactants. The affinity of HRH for LDL in the insoluble complexes was estimated between 1 and 10 microM. Insoluble LDL-heparin complexes were readily dissociated with 1.0 M NaCl, and their formation was prevented by acetylation of the lysine residues on LDL.

Animals↗
PubMed1987

Advanced laryngeal cancer: a management perspective.

A retrospective study of 197 T3 and T4 squamous cell carcinomas of the larynx presenting between 1969 and 1978 has been undertaken. These patients have in the main been treated by primary radiotherapy with back-up salvage surgery. The aim of the study was to examine survival, and to try to identify reasons for failure of control. Various prognostic factors have been analysed and are discussed. Overall 5-year survival was 53 per cent but patients with nodal disease responded poorly. Subglottic tumours have a better survival than usually reported. Failure to pick up recurrence was the main problem, and in particular a persistently fixed cord carried a very poor prognosis if laryngectomy was delayed.

Aged↗
PubMed1987

Marginal mandibulectomy for malignant disease: indications, rationale, and results.

The theoretical basis for performing marginal mandibular resection, as opposed to segmental resection, is discussed; and criteria are suggested. Results are presented that suggest that, in the treatment of malignant disease around the jaw, although the mortality from other tobacco- and alcohol-related diseases remains high, good functional and cosmetic results can be achieved with no loss of local control.

Humans↗
PubMed1987

Observations on femoral head abnormalities in broilers.

Detachment of the proximal femoral cartilaginous epiphysis was observed in broilers that were being down-graded at slaughter as a result of haemorrhage into thigh musculature. A traumatic aetiology is proposed with injury occurring at catching. Examination of field case material, and birds culled from a commercial flock of the same strain, revealed that physeal lesions are not infrequent in proximal femora. Clefts and areas of matrix necrosis occurred in normal and dyschondroplastic physeal cartilage. Clefts were thought to result from repetitive minor trauma insufficient to cause total detachment of the cartilaginous epiphysis. Total detachment may result from an acute traumatic episode or be a consequence of pre-existing physeal lesions. A traumatic aetiology suggests that in such cases the terms fracture separation or traumatic epiphyseolysis of the cartilaginous epiphysis are more appropriate than femoral head necrosis or degeneration.

Animals↗
PubMed1986

Malignant tumours of the tongue in young adults. Experience of a secondary referral centre.

Twenty-three cases of malignant tongue tumours in patients aged 15 to 30 are reported. Treatment and prognosis in the 18 for which follow-up information is available are discussed. The disease appears to be very similar to that in older subjects except for a greater incidence of neck node metastases. Close follow-up after primary treatment is essential since there is a high possibility of recurrent disease but which may respond well to salvage surgery if identified early. A greater awareness of the occurrence of tongue cancer in young adults is also necessary.

Adolescent↗
PubMed1986

Tendon lesions in broiler fowls.

Tendon lesions have been studied in 35 broiler or broiler breeder fowls. Tendon rupture most commonly affected the gastrocnemius and flexor muscles but was also seen in cranial tibial muscles (four cases) and the patellar tendon (one case). In nine birds tenosynovitis, characterised by a marked inflammatory response, was identified. In others, however, rupture occurred without appreciable inflammation and these cases were concluded to be comparable to spontaneous tendon rupture in other species. A traumatic aetiology is suggested in these cases, as other pelvic limb tendons or ligament rupture was a frequent concomitant finding. Degenerative tendon lesions were present but it is uncertain whether such changes are primary or secondary to rupture.

Animals↗