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Biomedical subjects

C A East

Publications and source records attributed to C A East.

At least 19 recordsLinked to original sources
PubMed2004

Gold weight implants in the management of lagophthalmos in facial palsy.

The otolaryngologist plays an essential role in the diagnosis and management of a facial palsy. We present one of the largest cohort prospective studies in the UK of 22 patients with gold weight implants, including ancillary oculoplastic techniques, and their outcomes. Facial paralysis places the eye at risk and protection and lubrication of the eye is paramount in the management of these patients. If recovery of facial function is likely to be delayed or negligible, gold weight loading of the upper lid has been shown to be effective in providing a dynamic solution to lagophthalmos. Following surgery, complete eye closure was possible in the upright position in 18 patients (82%). Two patients had their weights removed secondary to infection (9%). At long-term follow up, four patients judged their vision to have deteriorated (29%). Two of these, after investigation by the ophthalmologists, were found to have pressure astigmatism and removal corrected the visual problems. Overall patient satisfaction with the procedure is high and all reported improvement in eye closure following the operation. An algorithm for the management of the eye in patients with facial palsy is outlined.

Cohort Studies↗
PubMed1997

Nitric oxide does not reverse pulmonary hypertension associated with end-stage liver disease: a preliminary report.

Pulmonary hypertension is a well known, though uncommon complication of end-stage liver disease (ESLD). Patients with severe pulmonary hypertension and ESLD undergoing orthotopic liver transplantation (OLT) may develop right ventricular failure and death. This study investigates the reversibility of pulmonary hypertension by the inhalation of nitric oxide in patients under evaluation for OLT. Ten patients with ESLD who were discovered to have moderate to severe pulmonary hypertension were administered nitric oxide via face mask in concentrations ranging from 0 to 80 ppm. Inhaled nitric oxide is a potent pulmonary vasodilator without apparent systemic effects. Nitric oxide had no demonstrable effect on mean pulmonary artery pressure (PAP) (37 vs. 37 mm Hg), transpulmonary gradient (TPG) (26 vs. 26 mm Hg), or pulmonary vascular resistance (PVR) (295 vs. 288 dynes x sec x cm (-5)). Two patients were discovered to have an elevated pulmonary artery occlusion pressure (PAOP) on baseline readings. The cause of pulmonary hypertension in these two patients was secondary to volume overload as a result of hepato-renal syndrome rather than primary pulmonary arteriolar pathology and was responsive to diuresis or dialysis but not to nitric oxide therapy. In conclusion nitric oxide does not reverse pulmonary hypertension associated with ESLD.

Administration, Inhalation↗
PubMed1995

A prospective randomised trial of the use of sodium bicarbonate and hydrogen peroxide ear drops to clear a blocked tympanostomy tube.

This randomised prospective trial compared the efficacy of sodium bicarbonate and hydrogen peroxide ear drops in clearing a blocked tympanostomy tube. Tympanostomy tubes, 110 in number, obstructed with blood or inspissated secretions were randomised into treatment and control groups. Details of the operative procedure were retrospectively collected from the patients notes. The patients were reviewed after 2 weeks for both clinical and tympanometric evidence of clearance of the tube and evidence of complications of the drops. There was no significant therapeutic advantage between the two drops (P > 0.9), but in both treatment arms there was a significant therapeutic advantage over a period of observation (P < 0.05 in both groups). Otorrhoea and pain on instilling the drops occurred with equal incidence in both treatment groups. As obstruction of tympanostomy tubes is a common occurrence which often prompts surgical reventilation, there is great potential for cost savings if conservative treatment can be used effectively. The treatments for obstructed tympanostomy tubes are reviewed and methods of prevention of this common occurrence are discussed.

Acoustic Impedance Tests↗
PubMed1995

The diagnosis of inflammatory sinonasal disease.

A prospective study was carried out on 25 consecutive patients referred to an outpatient clinic at The Royal National Throat, Nose and Ear Hospital, with a medical letter suggestive of sinusitis, to test the hypothesis that the diagnosis of inflammatory sinus disease could be made simply and accurately by employing systematic nasal endoscopy and a series of plain sinus X-rays. The study compared the diagnostic yields of the history, rigid nasal endoscopy and plain sinus films with computed tomography. All the investigations were performed on the same day. The interobserver variability between consultant ENT surgeon, senior registrar and registrar were compared. With heightened concern over the radiation exposure patients are receiving for medical investigations, the radiation exposure was determined for a selected group of patients. This study demonstrated that in the diagnosis of inflammatory sinonasal disease the clinical assessment correlated with the CT findings in over 90 per cent of cases. This accuracy was dependent on the experience of the clinician in using rigid nasal endoscopy. Interobserver variability ranged from 71 to 90.4 per cent in the correct diagnosis of underlying sinus disease. Close agreement was seen with the interpretation of CT scans. The concordance rate between plain films and CT scans was 87 per cent when reported by a consultant radiologist. This is in close agreement with previously reported studies. The average radiation exposure of coronal CT scanning was 218 times the dose for plain sinus X-rays.

Adult↗
PubMed1995

Intranasal salbutamol has no effect on mucociliary clearance in normal subjects.

Normal mucociliary clearance is essential for the healthy function of the upper and lower airways. Restoring normal clearance times in the presence of chronic disease would be a helpful adjunct in treating these patients. This double-blind placebo-controlled trial in 37 normal subjects compared topical salbutamol against placebo on nasal mucociliary clearance. Clearance rates were measured using the sacharine clearance technique and 34 patients completed the study. There was no effect of treatment, sex, order of treatment or period (interval between treatments) on mucociliary times. There was a weak positive correlation with age and there was a trend towards increased clearance times with salbutamol although this did not reach significance (P = 0.226). The results show that topical salbutamol appears to have no effect on nasal mucociliary clearance times in vivo in normal subjects.

Administration, Intranasal↗
PubMed1994

Global monitoring of positive surgical outcome: a feasibility study at the Royal National Throat Nose and Ear Hospital.

We present early results of a study looking at the feasibility of positive outcome 'monitoring' after every operation at the Royal National Throat Nose and Ear Hospital. A system for quantitative 'measurement' of outcome after every operation is still light years away, and as a result audit of outcome has lagged behind audit of structure and process. Our 'monitoring' approach involves simply documenting, for every patient, whether the individual goal of the operation has or has not been achieved. Piloting this system over a 6-month period in 1993 suggests that it is feasible and useful, providing the results are used as pointers to more detailed study, rather than as endpoints in themselves.

Feasibility Studies↗
PubMed1992

Preoperative CT scanning for endoscopic sinus surgery: a rational approach.

Recent research on inflammatory sinus disease has implicated a central role for the ethmoid labyrinth, which may influence changes in the maxillary and frontal sinuses. CT can provide excellent definition of the paranasal sinuses and particularly the ethmoids, which is a prerequisite for endoscopic surgery. We describe a prospective series of 110 coronal CT scans performed on patients with a clinical diagnosis of sinusitis who had undergone diagnostic nasal endoscopies and medical treatment prior to surgery. 86% of the scans showed abnormal mucosal thickening. The ethmoids were affected in 73% and the maxillary sinus in 64%. Pneumatization of the middle turbinate was a common variant and when present was associated with anterior ethmoid disease in 60% of patients. Anterior ethmoid inflammatory changes were demonstrable in 95% of patients with maxillary sinus disease. Direct coronal CT can readily demonstrate disease in the infundibulum, frontal recess and posterior ethmoids in the same orientation confronting the endoscopist, and helps in the planning of ethmoidal surgery. Following surgery the sinuses can be directly inspected in outpatients which reduces the need for any further plain radiographs. It is important that the diagnosis of sinusitis is not based on CT findings alone as isolated areas of mucosal thickening are common in the normal population.

Endoscopy↗
PubMed1991

Bone-inducing implants in head and neck surgery: an experimental study.

The use of autologous bone for head and neck reconstruction requires a separate harvesting procedure which provides limited quantities of bone that may become infected or undergo resorption after being implanted. In this study, a collagen/ceramic carrier containing osteoinductive factor extract (OFE) was used in a rabbit facial augmentation model. Bone-inducing activity of these implants were evaluated in subcutaneous, intramuscular, and subperiosteal sites. Implants with (test) and without OFE (control) were placed on opposite sides of the face in 40 rabbits, and were harvested at 21 days. Bone formation was evaluated by implant alkaline phosphatase determinations and histomorphometry. Osteoblastic activity, bone formation, and preservation of facial augmentation were noted in the OFE implants, showing maximal bone formation when implanted subperiosteally. Control (no OFE) and demineralized bone implants showed no bone formation. Before these implants can be used clinically, novel bone-inducing factors must be manufactured by recombinant deoxyribonucleic acid (DNA) methodology to verify activity of the homogeneous molecule which would be free of other proteins or infectious agents.

Alkaline Phosphatase↗
PubMed1991

Mastoid obliteration with the temporoparietal fascia flap.

Obliteration of persistently discharging open mastoid cavities is one surgical option to achieve a dry ear. All the currently described techniques involve the use of random pattern local tissue flaps or free grafts. Ten patients have undergone obliteration procedures using the vascularized temporoparietal fascia flap. This resulted in rapid epithelialization by six weeks in seven out of 10 cases. The remaining three patients have persistent non healed areas over the medial attic wall, but are not troubled by otorrhoea. The indications, technique and complications of mastoid obliteration by this axial pattern flap are described.

Adolescent↗
PubMed1991

Composite tragal perichondrial/cartilage autografts vs cartilage or bone paste grafts in tympanoplasty.

Extrusion of plastic or ceramic implants is a significant cause of failure in ossiculoplasty for chronic ear disease. This paper reports the use of a composite tragal cartilage and perichondrial autograft compared to cartilage or bone paste between the graft and tympanic membrane. At 2 years, there were no extrusions in the group with the composite graft (n = 18) and 5 extrusions in the cartilage/bone paste group (n = 18) (P = 0.02). The mean average air-bone gap was significantly better for the composite grafts at 2 years (15 dB vs 24 dB) (P less than 0.05). Extrusions were eliminated and hearing results better at 2 years using the composite graft.

Biocompatible Materials↗
PubMed1991

Osteoinductive biomaterials for medical implantation.

The search for the ideal implant material continues since presently available implants all have significant drawbacks. This paper reviews three studies that we recently completed with bone-inducing implants. Long-term clinical follow-up of 75 allogeneic demineralized bone implants showed an average degree of resorption of 49%. Implants used for dorsal nasal augmentation showed an average degree of resorption of 50.7%, increasing to 82.5% after a 24-month follow-up. The efficacy of demineralized bone implants is dependent on many factors including site of implantation, method of preparation, etc. Transforming growth factor-beta 1 (TGF-beta 1) is a regulator of bone formation. We combined recombinant TGF-beta 1 with demineralized bone powder in a rabbit facial augmentation model. At 6 weeks, there was evidence of increased bone formation in the implants containing TGF-beta 1. Even though TGF-beta 1 can increase bone formation in demineralized bone implants, the overall bone-inducing activity in these implants seems to be suboptimal. Osteoinductive factor extract (OFE) is a partially purified bone factor preparation that has been shown to form bone when implanted into rats. Using a collagen/ceramic carrier, we implanted OFE into a rabbit facial augmentation model. At 21 d, histomorphometry revealed numerous osteoblasts and bone formation in the OFE implants. The bone-inducing activity of many partially purified osteoinductive preparations such as OFE is probably due to Bone Morphogenetic Protein-2A (BMP-2A), which has been shown to induce bone formation in its recombinant form. Recombinant DNA methodology provides the technology necessary to produce these molecules in their homogeneous form, permitting evaluation of bone-inducing activity in a preparation free of contaminants. Finally, the ideal carrier must be devised to permit safe and effective delivery of recombinant bone-inducing factors.

Animals↗
PubMed1990

Intralesional interferon gamma treatment for keloids and hypertrophic scars.

Keloids and hypertrophic scars are characterized by excessive collagen formation. Interferon gamma is a lymphokine that can down-regulate collagen synthesis in vitro and in vivo and, therefore, has potential therapeutic benefit in the management of abnormal scars. Intralesional scar injections of interferon gamma were performed to determine the tolerance toxicity and to obtain preliminary evidence for the efficacy of this treatment in the management of hypertropic and keloid lesions. All scars decreased in linear dimensions and flattened out. Five of 10 scars studied decreased at least 50% in linear dimensions. Interferon gamma can safely be administered intralesionally once per week up to a dosage of 0.05 mg for 10 weeks with no serious toxic effects. The commonest reported side effect was a mild headache.

Adult↗
PubMed1989

Normalization of LDL receptor function by lymphocytes of patients with heterozygous familial hypercholesterolemia after treatment with plasma cholesterol lowering agents.

Low density lipoprotein (LDL)-dependent growth of mitogen-activated lymphocytes, inhibited in their capacity to synthesize cholesterol endogenously, can be used as an assay of functional receptors for LDL. Using this technique, abnormalities can be detected in circulating lymphocytes obtained from patients with familial hypercholesterolemia (FH). Functional lymphocyte LDL receptor activity was decreased in patients with heterozygous FH. Following treatment with the specific inhibitor of cholesterol synthesis, lovastatin, alone or in combination with a bile acid-binding resin, there was increased expression of functional lymphocyte LDL receptors in five of nine patients. Plasma LDL cholesterol levels decreased in all nine patients. Three other patients who were only studied while receiving therapy also manifested increased expression of functional lymphocyte LDL receptors. The degree of improvement in plasma LDL cholesterol did not predict the effect on lymphocyte LDL receptor function. Longitudinal studies indicated that an increase in functional LDL receptor activity could be observed with 4 weeks of therapy and persisted for at least 18 months on continuous treatment. These results provide direct evidence that therapy with lovastatin and a bile acid-binding resin can lead to increased expression of functional LDL receptors by lymphocytes in the majority (eight of 12) of patients with heterozygous FH.

Anticholesteremic Agents↗
PubMed1989

Desferrioxamine ototoxicity: evaluation of risk factors in thalassaemic patients and guidelines for safe dosage.

Forty-seven patients with thalassaemia have been studied to define risk factors for development of sensorineural hearing loss, and to establish guidelines for safe chelation. Sensorineural hearing loss was only present in patients who had previously received desferrioxamine (DFO). The two most significant risk factors were the maximum dose of DFO previously received (P less than 0.01), and a serum ferritin of less than 2000 micrograms/l at that time (P less than 0.001). A therapeutic index obtained from the ratio of the mean daily dose of DFO mg/kg divided by the serum ferritin identifies patients with a ratio of greater than 0.025 as at risk of sensorineural hearing loss (P less than 0.001) and can be used as a guideline for safe DFO dosage. Follow-up audiometry of the affected patients over a 2-year period indicated that adjustment of the dose to a therapeutic index of less than 0.025 resulted in the stabilization of hearing loss in seven patients and improvement in two.

Adolescent↗
PubMed1989

Resection of the extra cranial carotid artery in head and neck cancer.

Carotid artery resection and reconstruction by unreversed autogenous saphenous vein grafting was undertaken in six patients undergoing extensive resection for malignancy over a four-year period. There were two deaths within 30 days of operation: one from secondary hemorrhage and one from bronchopneumonia. One patient died at six months and one at three months from recurrence, one died at 12 months from recurrence and one died free of disease at 10 months from aspiration. Vascular complications in three patients included a single TIA at 14 days, graft thrombosis with hemiplegia and a secondary hemorrhage from the graft requiring graft ligature with a subsequent normal neurological status. Malignant involvement of the extracranial carotid artery is associated with poor survival. Treatment by carotid artery resection and grafting should be considered in such cases, particularly where the pharynx or oral cavity are not entered.

Aged↗