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Biomedical subjects

D W Proops

Publications and source records attributed to D W Proops.

At least 37 records · Page 2Linked to original sources
PubMed1995

An in vitro growth study on cholesteatoma and normal skin.

The ability of cholesteatoma to grow rapidly within the ear is well recognized. This study aimed to quantify the in vitro growth of cholesteatoma derived cells. Following removal of cholesteatoma explant cultures were established. Cellular outgrowths were subcultured and a colony forming assay performed. Cells were repeatedly passaged every 14 days until senescence was observed. In comparison with cells derived from normal scalp skin, cholesteatoma derived cells demonstrated a lower colony forming efficiency in both primary and secondary subcultures, achieved fewer passages and cell generations in serial culture, and achieved a lower total population expansion. No evidence was found to suggest an intrinsic loss of growth control. It is proposed that the majority of cholesteatoma is composed of cells with a limited capacity for growth. Explant studies suggested that these may be the progeny of more highly proliferative cells situated at the neck of the cholesteatoma sac.

3T3 Cells↗
PubMed1994

Munchausen syndrome by proxy unmasked by nasal signs.

The protean manifestations of child abuse continue to cause diagnostic difficulty. Recent observations of the high mortality in victims of Munchausen syndrome by proxy, and their siblings, reinforce the need for early diagnosis and appropriate intervention. We report the nasal manifestations which unmasked Munchausen syndrome by proxy in an infant who presented with intestinal and peri-orifical signs masquerading as Crohn's disease. The possibility of Munchausen syndrome by proxy should be considered in an infant with persistent nasal excoriation presenting as part of an undiagnosed illness.

Adult↗
PubMed1993

Osseointegrated implants in the management of childhood ear abnormalities: the initial Birmingham experience.

Over a four-year period 72 children with ear abnormalities have been referred for assessment by the extraoral osseointegrated implant team at The Queen Elizabeth Hospital, Birmingham. Thirty-two children have been judged suitable for rehabilitation. Twelve children have completed rehabilitation using bone-anchored hearing aids and/or auricular prostheses. Two fixtures (seven per cent of those loaded) have dislodged and required replacement. Audiological assessment of the bone-anchored hearing aid users shows only small improvements in their aided thresholds, compared to thresholds obtained with their previous aid. However all now have thresholds of 30 dB(A) or better and report a marked improvement in sound quality. When surveyed, hearing aid and prosthesis users report high levels of satisfaction with this form of rehabilitation. The technique adds a new dimension to the management of children with aural anomalies. The approach and results of a multidisciplinary programme are reported.

Adolescent↗
PubMed1993

Severe cochlear dysplasia causing recurrent meningitis: a surgical lesson.

Meningitis may be the sole presenting sign of a cerebrospinal fluid (CSF) fistula of the temporal bone. An eight-year-old boy suffering from recurrent meningitis was found to have bilateral severe cochlear dysplasia. Bilateral tympanotomies were performed, planning to obliterate each vestibule. In the right ear a stapedectomy was performed, resulting in a torrential 'CSF gusher' and difficulty in packing the vestibule. CSF rhinorrhoea requiring revision surgery and two episodes of gram-negative bacterial meningitis complicated the post-operative management, resulting in a prolonged hospital stay. Subsequently, the left ear was managed in a different fashion, leaving the stapes in situ, with grafts placed to seal the oval window niche. We would recommend this alternative procedure in cases of severe cochlear dysplasia, where abnormalities of the vestibule and basal turn of the cochlea mean that performing a stapedectomy to pack the vestibule may result in a severe 'CSF gusher', by opening directly into the subarachnoid space.

Bone Diseases↗
PubMed1993

Nasal capnography in children: automated analysis provides a measure of obstruction during sleep.

A detailed analysis was made of nasal capnograms obtained from sleeping children with differing degrees of sleep-induced respiratory obstruction, the severe form being known as obstructive sleep apnoea. Clinical observations of these children were compared with analyses of nasal capnography data. During periods when the degree of obstruction was consistent throughout the first hour of sleep, the means and coefficients of variation of several parameters, derived from the capnograms were calculated. The coefficients of variation showed a close relationship to the degree of obstruction. In comparison, measures of end-tidal carbon dioxide concentration proved to be a very insensitive index of the degree of obstruction. The conclusion is that the usefulness of nasal capnography in predicting and grading obstruction can easily be extended by the use of statistical measures of dispersion and that this concept warrants further work.

Airway Obstruction↗
PubMed1993

Detection of laryngeal cancer--the case for early specialist assessment.

The first 300 patients referred from 11 participating general practices (GPs) to the Hoarse Voice Clinic, Queen Elizabeth Hospital, Birmingham, were studied prospectively to estimate the accuracy of GPs' diagnosis of laryngeal symptoms and to assess whether the provision of a direct referral immediate access service for the assessment of persistent laryngeal symptoms is an effective way of ensuring early referral and detection of laryngeal cancer. The GPs' assessment of laryngeal symptoms was inaccurate. Diagnosis after the initial clinic visit was accurate, predicting all histological cases of cancer. Laryngoscopy was possible in all patients at the first clinic visit. Disease requiring admission for direct laryngoscopy and biopsy was found in 39 patients (14%). Ten (3.3%) were found to have laryngeal cancer, of which eight were early lesions. When seen in the clinic 102 (34%) had normal voices and larynxes. A hoarse voice is a symptom requiring specialist assessment. By using the flexible fibreoptic nasendoscope all patients larynxes can be seen in clinic, an accurate diagnosis quickly made and the appropriate management instigated. It is feasible to offer this service without appointments to patients with persistent hoarseness.

Ambulatory Care↗
PubMed1992

Hypoxia in sleeping children: overnight studies can be reduced to 4 hours without loss of clinical significance.

Twelve recordings of overnight pulse oximetry representing a range of severity of obstructive sleep disturbance were evaluated by 7 experienced clinicians. Each recording was then scored by counting the number of minutes in each hour affected at any time by a fall in saturation to below 90%. Comparison of the clinical evaluation and the overall scores gave a clear level of 5 minutes per hour at and above which all the assessors agreed that the charts had clinically important desaturation. Overnight pulse oximetry was then performed on 25 children aged between 12 months and 10 years about to undergo adenotonsillectomy. The charts were scored by the method above with a score of 5 or more indicating a positive result for hypoxic episodes. The scores for shortened analysis periods of 1, 2, 3 and 4 hours duration were compared with the overall score and no cases which were negative, up to and including 4 hours, became positive in the overall result. Thus recording pulse oximetry for 4 hours provides sufficiently accurate information for clinical purposes.

Child↗
PubMed1991

Production of parathyroid-hormone-related protein by cholesteatoma cells in culture.

Specimens of cholesteatoma were removed at surgery from five patients who had evidence of bone resorption. Parathyroid-hormone-related protein (PTHrP) was detected, by radioimmunoassay, in conditioned media from keratinocyte cultures derived from all five samples. Concentrations of PTHrP in conditioned media from secondary cultures were higher for the cholesteatoma cells than for normal keratinocytes from controls matched for age and sex. Thus, production of PTHrP by cholesteatoma may be a contributory factor in the bone destruction commonly associated with this disorder.

Adolescent↗
PubMed1991

Management of epistaxis in children.

A randomised clinical trial of antiseptic nasal carrier cream (Naseptin) and silver nitrate cautery in the treatment of epistaxis in children was carried out. Fifty-four percent responded to cautery with silver nitrate and 50% to treatment with Naseptin antiseptic carrier cream. There were 24 patients in each group. No statistically significant difference was observed between the groups when tested with the chi 2 test. We believe that the first line treatment of epistaxis in children should be the use of antiseptic nasal cream.

Adolescent↗
PubMed1991

An animal investigation into the effects of tympanostomy on middle ear mucociliary function and cilia.

The effect of tympanostomy on guinea-pig middle ear mucosa with particular reference to mucociliary function and cilia was investigated. 13 guinea-pigs were used; 5 acted as the control group with no surgical intervention whilst the other 8 had perforations made in one tympanic membrane. 6 weeks later an attempt was made to measure mucociliary function in all the ears, but this was unsuccessful. However, it would appear that fashioning a perforation in the tympanic membrane causes no histological changes in this animal model.

Animals↗
PubMed1990

Role of routine fluid replacement in children undergoing tonsillectomy.

It has been suggested that children undergoing tonsillectomy would benefit from an intravenous infusion, to counteract the period of pre-operative fasting combined with the blood loss at operation. A prospective study of 50 children undergoing tonsillectomy was undertaken. The children were randomly allocated into two groups, one to receive an infusion and a control group. There were no significant differences between the two groups, although the children with an infusion had a longer mean post-operative stay. There would seem to be no role for routine intravenous fluid replacement in children undergoing uncomplicated tonsillectomy.

Adolescent↗
PubMed1990

Fine needle aspiration cytology of salivary gland lesions.

Eighty-eight fine needle aspirates from 79 salivary gland lesions in 77 patients were examined. The overall diagnostic sensitivity was 84% and the specificity 98.41%. When the 14 unsatisfactory specimens were excluded the sensitivity rose to 95.45%. Correct identification of the disease process was possible in nearly 80% of cases with a final benign diagnosis. The histological tumour type was correctly predicted in 75% of the malignancies. In the others the cytological diagnosis was anaplastic malignant neoplasm.

Adolescent↗
PubMed1990

Scanning electron microscopy of tympanic membrane epithelium during in vitro migration.

The en masse locomotion in tissue culture of stratified squamous epithelium of the tympanic membrane and cholesteatoma is a unique feature of these epithelia. A scanning electron microscopy study of cultures was carried out to seek features of surface architecture that might throw light on this special activity. Differences from cultures of non-migratory stratified squamous epithelium include the following: numerous lamellae emanating from the top surface of cells at the leading edge, a ridge of spent leading edge cells behind that edge, a cap of keratin behind the latter and large balloon-like swelling of cells is prevalent in the trailing edge. It is suggested that differentiation of migrating stratified squamous epithelium in tissue culture is towards specialized cells active in migration as shown by the leading and trailing edge cells, as well as towards keratinization as shown by the keratin cap.

Adult↗
PubMed1989

Cryptococcosis of the larynx.

An unusual case of cryptococcosis of the larynx is described in a non-immunocompromised patient. To our knowledge this is the second reported case in the literature.

Adult↗