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Biomedical subjects

M Keene

Publications and source records attributed to M Keene.

17 recordsLinked to original sources
PubMed1991

Hearing loss in chronic renal failure-hearing threshold changes following haemodialysis.

The prevalence of sensorineural hearing loss, measured by pure tone audiometry, was determined in 66 patients with chronic renal failure and threshold changes following haemodialysis were measured in 31 patients. The incidence of hearing loss was 41% in the low, 15% in the middle and 53% in the high frequency ranges respectively. No correlations with weight changes, haematocrit, metabolic bone disease or ototoxic drug history were found. Of 62 ears studied, 38% had a decrease in low frequency threshold after dialysis and 9% had an increase. Threshold in 22/31 ears with pre-existing low frequency loss altered after dialysis with little change in other frequencies and no correlation with weight changes. In conclusion, we find a high incidence of low and high frequency hearing losses in chronic renal failure patients. Fluctuation in low frequencies with dialysis is common. Possible mechanisms include treatment induced changes in fluid and electrolyte composition of endolymph.

Adult↗
PubMed1986

Excision of Bartholin duct cysts using the CO2 laser.

Many methods have been used to treat cystic enlargement of the duct of the Bartholins gland. Widely used methods have the disadvantage of recurrence, hemorrhage, persistent drainage, or considerable scarring. The carbon dioxide laser offers a simple and effective means of treating cystic Bartholin ducts. Ten patients were treated with the CO2 laser. The cyst was incised with the laser and the cyst wall was vaporized from the inside. In a follow-up period of one to four years, there were only two recurrences, and these responded to a second treatment. Surgery was rapid and uncomplicated in all cases, and healing occurred without scar formation. The CO2 laser offers several advantages over conventional methods for treating cysts of the Bartholin duct.

Adolescent↗
PubMed1984

Clinical monitoring of the effects of gentamicin by electrocochleography.

Eight patients receiving prolonged treatment with gentamicin for bacterial endocarditis were monitored for possible ototoxicity using transtympanic electrocochleography as an adjunct to pure tone audiometry, vestibular function tests and serum gentamicin levels. An immediate effect of intravenous gentamicin on the cochlea, shown by changes in the whole nerve action potential and/or cochlear microphonic was recorded in seven patients, none of whom had experienced vestibular or auditory symptoms with gentamicin prior to testing. Two patients subsequently developed evidence of vestibular dysfunction, and a high frequency sensorineural hearing loss occurred in a third individual. There have been no previous report of the immediate effects of gentamicin on the human cochlea to date. The significance of these findings in routine clinical monitoring of ototoxicity is discussed in the light of clinical and animal evidence for the possible mode of action of aminoglycosides on the auditory and vestibular apparatus.

Action Potentials↗
PubMed1984

Hypothalamic hypopituitarism in a patient with a basal encephalocoele--treatment with luteinizing hormone-releasing hormone.

A 20-year-old patient presented with primary amenorrhoea and growth hormone deficiency caused by a basal encephalocoele. She was found to have developed diabetes insipidus in the 8 years following diagnosis. Gonadotrophin release in response to bolus injection of luteinizing hormone-releasing hormone (LHRH) was normal, as was thyrotrophin and adrenocorticotrophin (ACTH) secretion. Pulsatile administration of LHRH by the subcutaneous route resulted in normal ovulation and subsequent menstruation. The investigation and management of patients with basal encephalocoeles are discussed in the light of these findings.

Adult↗
PubMed1982

ENT.

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Ear Diseases↗
PubMed1982

Histopathological findings in clinical gentamicin ototoxicity.

The temporal bone histopathological findings in a case of gentamicin sulfate-induced hearing loss and vertigo in an anephric patient undergoing hemodialysis are presented. A study of the sensory neuroepithelium of the cristae and maculae disclosed the presence of vacuoles with clubbing of the sensory cells. In the cochlea, loss of the innermost row of outer hair cells in the basal turn was the most prominent feature. These findings are discussed in light of reports of similar morphological changes in laboratory studies of gentamicin ototoxicity.

Ear, Inner↗
PubMed1982

Histopathological study of radionecrosis in laryngeal carcinoma.

With modern radiotherapy techniques, clinical radionecrosis is uncommon following eradication of primary squamous cell carcinoma from the larynx. Histologic sections from 265 specimens, prepared by the technique of whole organ subserial step-sectioning were studied to determine the incidence and location of chondronecrosis and/or osteomyelitis in both irradiated and non-irradiated cases. Chondronecrosis occurred in only 1 of 41 early (pT1 - pT2) tumors but in 143 advanced tumors (pT - pT4) treated with radical radiotherapy and containing residual carcinoma, 27% had evidence of significant necrosis, compared with 24% of those not irradiated. Age, sex, tumor grade and previous laryngeal surgery did not appear to be significant factors in the development of necrosis in irradiated patients. The arytenoid cartilage was most frequently involved when chondronecrosis occurred in association with radiotherapy. Six total laryngectomy specimens (3%) were received from patients with symptoms of chondronecrosis and in whom no residual tumor was present. We conclude that although the incidence of clinical perichondritis is low, histologic chondronecrosis and/or osteomyelitis occurred in 26% of all the larynges studied. Radiotherapy appears to be a significant causative factor only in advanced supraglottic tumors.

Adult↗
PubMed1981

Artificial eustachian tube-induced keratin foreign-body granuloma.

The pathogenesis of granulation tissue that arises periodically around artificial Eustachian tubes was elucidated by histologic examination of 15 cases of tube granuloma. All cases showed the presence of a keratin foreign-body granuloma. The implanted squames incited a foreign-body type of granulomatous reaction and produced a friable vascular exuberant mass that surrounded the artificial Eustachian tube. Histologically, the tube granuloma was characterized by the presence of irregular ovoid slit-like spaces that contained keratin squames, and it was surrounded by foreign-body giant cells.

Adult↗
PubMed1981

Nasal obstruction in pituitary tumours.

A case of pituitary tumour with unusual nasal extension is reported. The literature is reviewed and the histological features, differential diagnosis and management are discussed. The treatment of choice appears to be a transsphenoidal exploration of the pituitary fossa with insertion of a free muscle graft followed by radiotherapy.

Adenoma, Chromophobe↗
PubMed1981

Pathogenesis and detection of aminoglycoside ototoxicity.

Aminoglycoside antibiotics are widely prescribed in the treatment of serious gram negative sepsis. The more recently developed members of this group, although purporting to be less ototoxic, are also capable of producing inner ear damage in sufficiently high doses. This paper reviews the morphological, histochemical, and electrophysiological evidence concerning the mode of action of aminoglycosides on the auditory and vestibular systems and discusses the available methods for the detection of possible clinical ototoxicity. Guidelines are proposed to assist the otolaryngologist when advising about the prevention of ototoxicity and the management of patients with established auditory or vestibular dysfunction.

Aminoglycosides↗
PubMed1981

Occult intralabyrinthine schwannoma.

Report of a case of an intralabynrinthine schwannoma discovered unexpectedly during a labyrinthectomy for intractable vertigo, and description of the light and electron microscopic appearances. Although only 18 of these tumors have been previously reported, it is possible that some cases which are categorized as peripheral vertigo of unknown origin, may be due to an occult Schwannoma. All material removed during surgical procedures on the inner ear should therefore be submitted for histopathological examination.

Female↗
PubMed1980

Cerebrospinal fluid rhinorrhoea in pituitary tumours.

Three cases of CSF rhinorrhoea due to pituitary tumours are reported and the literature reviewed. The treatment of choice appears to be trans-sphenoidal exploration of the pituitary fossa with insertion of a free muscle graft followed by radiotherapy. The probability of the tumour being a prolactin-secreting adenoma is discussed.

Adenoma↗
PubMed1979

Pituitary calcospherites: an aid to highly selective hypophysectomy.

A case of a prolactin-secreting pituitary adenoma containing calcospherites is reported. The difficulties in achieving a highly selective microdissection of large pituitary tumours are discussed and the value of calcification within a prolactinoma emphasized.

Adenoma, Chromophobe↗
PubMed1977

Histones H2a, H2b, H3, and H4 are present in equimolar amounts in chick erythroblasts.

A quantitative labeling method for stoichiometric analysis has been applied to an investigation of the histone composition of chick erythroblast chromatin. The necessity of long fractionation procedures and the dangers of preferential extraction and staining are eliminated through the use of this simple procedure which involves the direct analysis of nuclear proteins on sodium dodecyl sulfate gels. Only a knowledge of the amino acid compositions of the histones is required. H2a, H2b, H3, and H4 are found to be present in nearly equimolar quantities.

Animals↗