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Biomedical subjects

R Mills

Publications and source records attributed to R Mills.

At least 19 recordsLinked to original sources
PubMed2006

Experimental study on heat transmission to the vestibule during CO2 laser use in revision stapes surgery.

We studied the transmission of heat to the vestibule during revision stapes surgery with a piston in situ, using a CO2 laser, in an in vitro model. A type K thermocouple was placed around the medial end of stainless steel and fluoroplastic wire pistons in a 'vestibule' filled with saline. The effect of laser hits on fluoroplastic wire and stainless steel stapes prostheses was investigated. The effect of introducing a vein graft to seal the stapedotomy was also examined. Greater temperature rises occurred with stainless steel than with fluoroplastic wire pistons. The addition of the vein graft reduced heat transmission. Application of the CO2 laser to fluoroplastic wire pistons, using the power settings suggested by the manufacturer, is not likely to damage the inner-ear structures. Application of 6 W laser energy to stainless steel pistons can potentially disturb the inner-ear function.

Hot Temperature↗
PubMed2006

Applied comparative physiology of the avian middle ear: the effect of static pressure changes in columellar ears.

We investigated the motion of the single ossicle found in the middle ears of four different species of birds. In the avian middle ear, the off centre attachment of the extracolumella to the tympanic membrane and the flexion of the joint between the extracolumella and columella results in rocking of the footplate rather than direct excursion in and out of the vestibule. We postulate that this is a protective mechanism to avoid excessive displacement of the footplate into the vestibule during changes in middle-ear pressure and that it is analogous to the ossicular 'decoupling' observed in the human middle ear in the same circumstances.

Animals↗
PubMed2006

Rosen mobilization of the stapes: does it have a place in modern otology?

We describe two patients with stapes fixation, in both of whom Rosen mobilization seemed to be the most prudent surgical choice. In both cases, a useful hearing gain was achieved initially. In the patient with otosclerosis, the conductive hearing loss recurred and a stapedectomy was subsequently carried out. In the patient with congenital stapes fixation, the hearing gain was maintained for two years eight months. We believe that this technique still has a place in stapes surgery in rare instances.

Adolescent↗
PubMed2006

Surgical management of retraction pockets of the pars tensa with cartilage and perichondrial grafts.

Stable, self-cleansing retraction pockets of the pars tensa are common incidental findings and require no treatment. In other cases, recurrent discharge occurs and there may also be associated conductive hearing loss. In a minority of cases, cholesteatoma may develop. This paper presents the results of surgery using a graft composed of cartilage and perichondrium for retraction pockets involving the posterior half of the tympanic membrane, as well as early results using a larger graft designed to manage retraction of the entire tympanic membrane. Data on 51 patients with posterior retraction pockets are presented. Forty-two (82 per cent) patients had no aural discharge one year following surgery and the tympanic membrane was not retracted in 43 (84 per cent). The larger 'Mercedes-Benz' graft was used in four patients and the results obtained suggested that it may prove a successful technique for extensive retraction pockets.

Cholesteatoma, Middle Ear↗
PubMed2004

The management of acute oesophageal obstruction from a food bolus. Can we be more conservative?

The objective was to assess the number of patients with acute oesophageal bolus obstruction that resolves spontaneously and to aid the identification of the best practice. This prospective and retrospective case series study at a teaching hospital and a district general hospital in Scotland, UK, involved 37 patients with acute oesophageal obstruction from a food bolus who were observed for 24 h from the beginning of symptoms. The bolus passed spontaneously in 54% of the patients during the observational period. A short observational period following the admission of patients with acute food bolus obstruction is reasonable as it may reduce exposure to surgical morbidity and decrease inpatient stay.

Acute Disease↗
PubMed2003

Delayed facial palsy following laser stapedectomy: in vitro study of facial nerve temperature.

Delayed facial palsy following conventional stapes surgery is a rare event, but this complication appears to be more common when a laser is used. We have investigated the temperature in the facial canal during stapes surgery using a KTP laser or a microdrill in preserved human temporal bones. Thermocouples were placed in the facial canal and under the foot plate. The results show maximum rises in temperature of between 1.4 degrees C and 15.2 degrees C in the facial canal during laser surgery (mean 6.1 degrees C, SD 4.5 degrees C), but only between 0.45 degrees C and 2 degrees C during procedures in which a microdrill was used (mean 0.9 degrees C, SD 0.9 degrees C) (P = < 0.009). In addition, the facial nerve undergoes repeated heating and cooling cycles during the laser surgery. We conclude that heating of the facial nerve during laser surgery causes oedema, which in turn leads to compression of the nerve within its bony canal.

Adult↗
PubMed2003

Suicide prevention in first episode psychosis: the development of a randomised controlled trial of cognitive therapy for acutely suicidal patients with early psychosis.

BACKGROUND: Young people with early psychosis are at particularly high risk of suicide. However, there is evidence that early intervention can reduce this risk. Despite these advances, first episode psychosis patients attending these new services still remain at risk. To address this concern, a program called LifeSPAN was established within the Early Psychosis Prevention and Intervention Centre (EPPIC). The program developed and evaluated a number of suicide prevention strategies within EPPIC and included a cognitively oriented therapy (LifeSPAN therapy) for acutely suicidal patients with psychosis. We describe the development of these interventions in this paper. METHOD: Clinical audit and surveys provided an indication of the prevalence of suicidality among first episode psychosis patients attending EPPIC. Second, staff focus groups and surveys identified gaps in service provision for suicidal young people attending the service. Third, a suicide risk monitoring system was introduced to identify those at highest risk. Finally, patients so identified were referred to and offered LifeSPAN therapy whose effectiveness was evaluated in a randomised controlled trial. RESULTS: Fifty-six suicidal patients with first episode psychosis were randomly assigned to standard clinical care or standard care plus LifeSPAN therapy. Forty-two patients completed the intervention. Clinical ratings and measures of suicidality and risk were assessed before, immediately after the intervention, and 6 months later. Benefits were noted in the treatment group on indirect measures of suicidality, e.g., hopelessness. The treatment group showed a greater average improvement (though not significant) on a measure of suicide ideation. CONCLUSIONS: Early intervention in psychosis for young people reduces the risk of suicide. Augmenting early intervention with a suicide preventative therapy may further reduce this risk.

Acute Disease↗
PubMed2003

Anaesthetic management of coronary artery bypass grafting in a patient with central core disease and susceptibility to malignant hyperthermia on statin therapy.

Central core disease and malignant hyperthermia (MH) are both associated with mutations in the RYR1 gene. We report the anaesthetic management of one such patient presenting for coronary artery bypass grafting. Her medication included aspirin 75 mg, atorvastatin 20 mg, isosorbide mononitrate 60 mg, atenolol 25 mg and glyceryl trinitrite sublingual spray as required. The use of aprotinin, statins and moderate hypothermia in patients with central core disease and known susceptibility to MH has not been documented.

Adult↗
PubMed2001

Fertility and sexual function following orchiectomy and 2 cycles of chemotherapy for stage I high risk nonseminomatous germ cell cancer.

PURPOSE: We investigate fertility and sexual function in patients following orchiectomy and adjuvant cisplatin based chemotherapy for high risk, stage I nonseminomatous germ cell tumor of the testis. MATERIALS AND METHODS: Between 1985 and 1994, 59 patients with stage I nonseminomatous germ cell tumor and poor prognostic factors were treated with 2 cycles of cisplatin, vinblastine and bleomycin, or bleomycin, etoposide and cisplatin after orchiectomy. At least 32 months following treatment all patients were contacted and asked to complete a questionnaire regarding fertility and sexual activity, and to volunteer for a semen and hormonal analysis. RESULTS: Of the 59 patients 49 (83%) completed the questionnaire. Before chemotherapy 18 (37%) patients had fathered children, 6 (12%) were involuntarily childless and none had a major sexual dysfunction. After treatment 11 (22%) patients fathered children, and 5 (10%) were involuntarily childless, with 4 involuntarily childless before chemotherapy. There were no significant alterations in sexual function. Semen analysis in 27 patients was normal in 23, and revealed mild oligospermia in 2 and azoospermia in 2. In 18 patients with hormone analysis median values for luteinizing hormone and free testosterone were normal but median value for follicle-stimulating hormone was slightly increased. CONCLUSIONS: Two cycles of cisplatin based adjuvant chemotherapy do not seem to affect adversely fertility or sexual activity.

Adult↗
PubMed2001

Phase shifting prior to spatial filtering enhances optical recordings of cardiac action potential propagation.

Optical imaging of cardiac electrical activity using a voltage-sensitive dye provides high spatial resolution maps of action potential propagation and repolarization. Charge-coupled-device (CCD) camera-based imaging systems, however, are limited by their low signal-to-noise ratio. We have developed an image processing method to enhance the quality of optical signals recorded using a CCD camera. The method is based on the observation that within a small neighborhood of adjacent pixels, the morphology of the optical action potential varies little except for a phase shift in time resulting from the propagation of the wavefront. The method uses a phase-correlation technique to first correct for this time shift before spatially filtering with a 5 x 5 Gaussian convolution kernel (sigma = 1.179). A length 5 median filter is then applied to further reduce noise by filtering in the temporal domain. The image-processing scheme allows for more accurate extraction of maps of electrical activation, repolarization, and action potential duration.

Action Potentials↗
PubMed2001

In vitro evaluation of a malleus head to stapes head 'incus replica' prosthesis.

An ossicular prosthesis produced by making a mould from a cadaveric incus and injecting ionomeric cement into it (incus replica prosthesis, IRP) has been cemented to the malleus head and stapes head and evaluated in fresh human temporal bones using a laser vibrometer. Stapes velocity was recorded under acoustic stimulation and foot plate displacements were derived. Fourteen frequencies between 125 Hz and 8000 Hz have been used. Measurements were made with the ossicular chain intact, following removal of the incus, with the prosthesis cemented to the malleus, but not the stapes, and with the incudo-stapedial joint cemented. In a second series of experiments the performance of the IRP was compared with that of a Causse partial ossicular replacement prosthesis, using the same experimental set-up. The results indicate that the prosthesis performs almost as well as the intact ossicular chain and that cementing the incudo-stapedial joint gives better sound transmission than leaving it uncemented. In addition the IRP outperforms the conventional partial ossicular replacement prosthesis.

Bone Cements↗
PubMed1999

Risk factors for chronicity in childhood otitis media with effusion.

One hundred and ninety-one children who presented to the author's clinic with otitis media with effusion (OME) over a 2-year period (1986-1988) have been studied prospectively. Resolution of their OME was considered to have occurred when they had normal findings on pneumatic otoscopy, tympanometry and audiometry on at least two occasions 6 months apart and had subjectively normal hearing in between. The number of operations performed during the course of the disease was used as a surrogate for chronicity. Children with a history of previous aural discharge at presentation were significantly more likely to have chronic OME (P = < 0.02).

Adolescent↗