Biomedical subjects

M Wake

Publications and source records attributed to M Wake.

At least 55 records · Page 3Linked to original sources

PubMed1995

Smoking and middle ear ciliary beat frequency in otitis media with effusion.

The middle ear mucociliary system has been shown to play an important role in clearing middle ear effusions. There is conflicting epidemiological evidence, however, as to whether exposure to tobacco smoke plays a significant role in persistence of middle ear effusion in patients with otherwise normal mucociliary function. Samples of middle ear mucosa from 33 patients with persistent otitis media with effusion (OME) were taken at myringotomy, together with corresponding nasal brushings. The aim of this study was to observe the mean ear ciliary beat frequency (CBF) and to compare it with nasal ciliary activity. Nasal brushings were collected from 33 age and sex matched non-smoking controls with no history of nasal atopy or topical nasal treatment. Ear CBF in OME was significantly reduced in comparison to paired nasal samples (p < 0.001). Ear CBF in adult OME patients who smoked or in children who were passive smokers was significantly less than in patients who were not exposed to cigarette smoke (p < 0.01). This study indicates that impaired ciliary function due to tobacco smoke exposure is an aetiological factor in persistent OME.

Adolescent↗

PubMed1995

[Usefulness of rapid detection of plasma insulin levels during resection of insulinoma].

Insulinoma is one of the causes of hypoglycemia and can be cured by surgery. Using the enzyme immunoassay kit (ERUMOTEC INSULIN, Mochida Pharmacy Co.), immunoreactive insulin (IRI) can be measured within one hour. Curative operation was confirmed by normalized IRI level. A 58-year-old man had an episode of loss of consciousness. His blood glucose was below, and his IRI was above, normal. These and other examinations revealed that he was suffering from insulinoma. Tumor resection under general anesthesia was scheduled. Glucose was continuously administered intravenously to prevent hypoglycemia until the end of tumor resection. Frequent blood glucose measurement showed that he had no hypoglycemic episodes. Using the enzyme immunoassay kit, IRI was found to be 704 microU.ml-1 during manipulation of the tumor. At 30 minutes after the tumor resection, it decreased to 9.8 microU.ml-1 (within normal ranges). These data suggested that the operation was curative and that no further hypoglycemic attacks by remnant insulinomas would be anticipated.

Anesthesia, General↗

PubMed1995

[Anesthetic experiences in 3 patients with multiple myeloma].

Multiple myeloma which occurs mostly in aged people is a neoplastic proliferation of plasma cells characterized by immunoglobulin disorders. It presents various kinds of signs and complications depending on its stage and involved organs, and these complications often require surgical treatment. Risk factors to be considered include renal failure, hemorrhagic tendency, increased susceptibility to infections, hyperviscosity syndrome, anemia, and hypercalcemia. We report 5 anesthetic experiences in 3 cases with multiple myeloma.

Aged↗

PubMed1995

[Extracorporeal circulation for removal of carcinoma of the lung invading the left atrium].

A 42-year-old man with one year history of cough and chest pain due to right upper lung cancer was scheduled for radical surgery. An echocardiogram and a lung scan showed a tumor mass in the left atrium, which was originating from carcinoma of the right upper lobe. Right pneumonectomy and atrial tumor extirpation were done successfully under the state of cardiac arrest using extracorporeal circulation with topical cooling by crushed ice in order not to spread the tumor cells into systemic circulation. He was extubated on the 1st postoperative day. But, thereafter he developed moderate dyspnea. On 7, 10 and 13th postoperative days he fell into the state of CO2 narcosis. Decreased capacity of the lung after the pneumonectomy and left phrenic nerve injury during the operation were considered factors causing the respiratory insufficiency. Patient was discharged 6 weeks later and continued to have consultations at the outpatient clinic.

Adult↗

PubMed1994

Cochlear function after selective inner hair cell degeneration induced by carboplatin.

The ototoxicity of carboplatin, a second generation anti-cancer agent, was examined using the chinchilla as an animal model. In animals treated with a clinical therapeutic dose (400 mg/m2), the dominant degenerative change is to inner hair cells (IHCs). This is in sharp contrast to most other ototoxic agents, which damage primarily the outer hair cells (OHCs). Functional changes to the cochlea have been evaluated in carboplatin treated subjects by recording cochlear action potentials (CAP) and cochlear microphonics (CM); cochlear lesions were evaluated using scanning electron microscopy. In carboplatin treated animals, CAP thresholds to tone-pip stimuli were elevated in proportion to IHC damage in corresponding cochlear regions. In contrast, CM amplitudes and 'thresholds' remained close to normal in most cases, reflecting the preservation of OHCs in the basal turn. These results indicate a high degree of independence between the inner and outer hair cell systems in the cochlear transduction mechanism. We suggest that this species-specific preparation with selective IHC loss will provide a valuable tool for studying, separately, the role of OHCs in both afferent and efferent cochlear function.

Acoustic Stimulation↗

PubMed1994

Surface morphology of middle ear epithelium in chronic ear disease.

The ultrastructural details of normal middle ear mucosa have been reported in detail in the literature. This study was aimed at investigating the superficial structure of middle ear epithelium with the scanning electron microscope in patients with persistent otitis media with effusion (OME) and chronic suppurative otitis media (CSOM), especially in the light of the authors' recent findings regarding decreased ciliary beat frequency (CBF) in patients exposed to tobacco smoke. Mucosal biopsies were taken from the anterior mesotympanum in four patients with OME and another four patients with CSOM. There was no significant abnormality of cellular surface structure in patients with chronic middle ear disease. Furthermore, no significant difference was observed between smoke exposed and nonsmoke exposed patients. It is concluded that the effect of tobacco smoke on CBF is functional and not related to any anatomical abnormality observed by scanning electron microscopy (SEM).

Adolescent↗

PubMed1994

The uncinate process: a histological and morphological study.

The uncinate process (UP) has become a familiar anatomical landmark to otolaryngologists due to the increasing popularity of functional endoscopic sinus surgery (FESS) in recent years. This study examines the histological and morphological features of UPs removed from a group of patients undergoing FESS operations for chronic sinusitis. The structure of the UP by light microscopy (LM) is reported. A relatively high proportion of goblet cells and seromucous glands was noted. Scanning electron microscopy (SEM) identified four surface cell types on the UP. Furthermore, four categories of surface morphology were noted. The most common appearance was of predominantly ciliated cells. A nonciliated surface ultrastructure is associated with a longer history of sinonasal symptoms and a higher incidence of surgical intervention.

Adult↗

PubMed1994

Selective inner hair cell ototoxicity induced by carboplatin.

Carboplatin is a second-generation platinum antineoplastic agent. It has biological activity similar to cisplatin and is currently recommended for the treatment of ovarian cancer. In clinical use, carboplatin appears less ototoxic than cisplatin. This paper reports the ototoxic effects of carboplatin, in doses equivalent to the clinical use of the drug, in the chinchilla. Intravenous carboplatin 200 to 400 mg/m2 by bolus injection caused significant ototoxicity in this model as revealed by brainstem evoked responses (ABR audiometry). The cochlear pathology as seen by scanning electron microscopy revealed predominantly inner hair cell (IHC) stereocilia damage. Furthermore, the extent (grade) of the morphological lesions appears to be well correlated with the auditory brainstem response pattern of threshold elevation.

Animals↗

PubMed1994

The early development of sino-nasal mucosa.

The development of human nasal mucosa was studied in 20 fetal heads between 8 and 24 weeks of gestation. Initially the nasal cavity is lined by a single layer of flattened cells, which produces two to three layers of undifferentiated spherical cells. Olfactory epithelium lines the cranial portion of the human fetal nasal cavity at 8 weeks of gestation. Pseudostratified ciliated cuboidal or columnar epithelium appears at 9 weeks of gestation in the nasal cavity and between 14 and 16 weeks of gestation in the primitive ethmoid sinuses and maxillary sinus infundibulum. Goblet cells and glandular acini appear between 12 and 14 weeks of gestation. Initially these goblet cells/glands are found predominantly in the anterior nasal cavity but are more evenly distributed at 24 weeks of gestation. The epithelial development of the nasal septum generally precedes that of the lateral nasal wall. This study documents nasal mucosal maturation and associated anatomic development in the human fetus.

Embryonic and Fetal Development↗

PubMed1994

[Perioperative management of a patient with myotonic dystrophy developing the cardiac symptoms initially prior to the neuromuscular symptoms].

The authors anesthetized a 48-year-old woman with endometrial cancer and a large ovarian cyst. She developed cardiac failure initially followed by the sick sinus syndrome and A-V block from hypertrophic cardiomyopathy, prior to neuromuscular symptoms. Epidural anesthesia assisted by general anesthesia was carried out safely without intravenous administration of any muscle relaxants. From this experience, it is considered that epidural anesthesia assisted with some other proper methods is suitable for surgery of lower abdomen.

Anesthesia, Epidural↗

PubMed1994

Induction of selective inner hair cell damage by carboplatin.

Carboplatin (diammine [1,1 cyclobutane dicarboxylato (2)-0,0'] platinum) is an anti-cancer agent which can be toxic to the inner ear. We have explored the nature of this ototoxicity in the chinchilla. In this species, initial degenerative changes appear to be restricted to the inner hair cell (IHC) regions of the organ of Corti. This finding is intriguing and unusual since all other known ototoxic drugs, such as aminoglycosides, are predominantly associated with outer hair cell damage. In the present study, the mechanism of ototoxicity was investigated by comparing two different routes of carboplatin administration. Carboplatin was administered either intravenously (i.v.) or intraperitoneally (i.p.). The mode of administration influenced electrophysiological and morphological changes. Hearing thresholds were elevated in the i.v. group significantly more than in the i.p. group at all tested frequencies. The degree of hair cell damage was evaluated by scanning electron microscopy at four frequency regions in each cochlea. IHC damage in the i.v. group was significantly more severe than in the i.p. group. Carboplatin effects on a different species, the guinea pig, were also determined to clarify interspecies differences. In the guinea pig, outer hair cell damage occurred sporadically and inner hair cells remained intact. In contrast, chinchilla inner hair cells are susceptible to the ototoxic effects of carboplatin. The degree of hair cell damage appears to be dependent on the peak level of carboplatin rather than on the total dose. This animal model provides a new tool for the investigation of inner and outer hair cell function.

Animals↗

PubMed1994

Ototoxicity of carboplatin: comparing animal and clinical models at the Hospital for Sick Children.

Carboplatin was introduced to the paediatric population as an alternative chemotherapeutic agent in the management of various malignant neoplasms, including sarcomas of the head and neck, in the hope that it would have fewer side effects than pre-existing agents. While many investigators have considered the ototoxicity of this drug only incidentally, others have presumed it to be of negligible importance. A recent animal model of its use has demonstrated damage to the inner hair cells of the cochlea, particularly at the basal turn, with a corresponding high incidence of hearing loss. Similarly, 11 of 22 patients who received this agent at the Hospital for Sick Children over the past 2 years demonstrated a sensorineural hearing loss in the 4 to 12 kHz range. This complication occurred as early as after the first dose and was generally progressively worse with subsequent doses. Consequently, we recommend careful audiologic monitoring of children receiving this agent.

Adolescent↗

PubMed1993

ENT cancer in the West Midlands region of England.

In the period 1978-1986, 2907 cases of ear, sinonasal and throat (ENT) cancers were registered in the computer data base of the West Midlands Cancer Registry, Birmingham. These cases have been examined by site and subsite in this article. Squamous cell carcinomas continue to dominate ENT cancer with notable male predominance. Histology, male/female ratios and time trend analysis are reported for this group of cancers.

Adult↗

PubMed1993

The urban/rural divide in head and neck cancer--the effect of atmospheric pollution.

Inter-district variations in the incidence of head and neck squamous carcinoma in the period 1978-1987 have been identified from records at the West Midlands Cancer Registry, England. Analysis of the records reflect the national and international trend of higher urban cancer rates compared with neighbouring rural communities. Atmospheric pollution data (mean sulphur dioxide and smoke concentrations) from a national survey are positively correlated with squamous cancer of the larynx and pharynx. The correlation is most significant between laryngeal cancer rates and atmospheric sulphur dioxide levels. The periods 1950-1970 and 1970-1990 have been analysed separately to reflect the reduction in atmospheric pollution that has occurred over these years and thus avoid missing a latent effect that this might have on cancer rates.

Air Pollutants↗

PubMed1993

Tissue culture of middle ear epithelium using fibroblast-reorganized collagen gels.

The middle ear epithelium of the guinea pig has been cultured on a modified floating collagen matrix. Fibroblasts harvested from abdominal skin dermis of allogenic animals were used to reorganize hydrated collagen gels into a dermal-like matrix. Within two days, the explants placed on the surface of these matrices showed proliferation of polygonal "outgrowth cells" which could be maintained for up to one month. During the first two weeks of the culture period, dividing cells were frequently identified. These cells were especially abundant in the marginal area of the explants and consisted of pseudostratified columnar cells. The reorganized collagen gel matrix was stable and did not dissolve even after the "outgrowth cells" became confluent. The present system should allow further elucidation of the growth and differentiation mechanisms of middle ear epithelial cells.

Animals↗

PubMed1992

The histology of 'stored' autologous ossicles.

Controversy still exists concerning the ultimate fate of transposed or transplanted ossicles in tympanoplasty. Histological studies on autologous and homologous ossicles removed at revision operations, or from animal studies, vary in their conclusions. The viability, of such materials used in the long-term is still uncertain. Whether this has any functional significance is also uncertain. This report contains a histological review of 10 ossicle remnants stored in the 'closed' mastoid cavity for 12 months, following closed cavity mastoidectomy (combined approach tympanoplasty).

Cholesteatoma↗

PubMed1992

Detection of recurrent cholesteatoma by computerized tomography after 'closed cavity' mastoid surgery.

Pre-operative Computerized Tomography was performed prior to second look operations in 10 cases to check for cholesteatoma after combined approach tympanoplasty. Three independent opinions were obtained on the CT scans and compared with the operative findings. This small series failed to demonstrate reliable pre-operative radiological detection of cholesteatoma. There was disappointing inter-observer agreement in interpretation of the CT scans.

Cholesteatoma↗

PubMed1992

Ciliary beat frequency of nasal and middle ear mucosa in children with otitis media with effusion.

Impaired mucociliary function of respiratory tract mucosa is associated with secretory otitis media in some well recognized syndromes. Ciliary activity per se may now be assessed directly by determination of ciliary beat frequency by a photoelectric technique. 49 children with otitis media with effusion undergoing surgical treatment were studied. Middle ear mucosa and nasal epithelial cells were obtained by biopsy and cytological brushings respectively at the time of surgery (myringotomy +/- grommet insertion under general anaesthesia). From these samples mean nasal ciliary beat frequency was 11.0 Hz and mean middle ear ciliary beat frequency was 11.2 Hz. A positive correlation exists between mean ciliary beat frequency of nasal and middle ear samples from individual patients. A comparison of mean ciliary beat frequency between children who were effusion positive and effusion negative at the time of surgery revealed no statistically significant difference. In addition, no difference existed between those children with recurrent otitis media with effusion and newly presenting cases. No prima facie evidence exists of impaired ciliary function in this population of children with otitis media with effusion.

Acoustic Impedance Tests↗