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Biomedical subjects

L Michaels

Publications and source records attributed to L Michaels.

At least 127 records · Page 7Linked to original sources

Laryngeal abductor paralysis in multiple system atrophy. A report on three necropsied cases, with observations on the laryngeal muscles and the nuclei ambigui.

Clinical and pathological findings are reported in three cases of Shy-Drager syndrome with laryngeal stridor severe enough to require tracheostomy. Indirect laryngoscopy in all three cases revealed a failure to abduct the vocal cords properly with a resulting narrowing of the glottic airway. Histological studies showed a marked atrophy of the posterior crico-arytenoid muscles and little atrophy of the other laryngeal muscles. The posterior crico-arytenoid muscles have the sole responsibility of abducting the vocal cords, so it is concluded that the patient's stridor was caused by the selective paralysis of these muscles. Histological studies of the posterior crico-arytenoid muscles were suggestive of denervation but despite this finding, no clear evidence of any motor cell loss in the nuclei ambigui was obtained. Other possible causes of the selective posterior crico-arytenoid atrophy are discussed.

Autonomic Nervous System Diseases↗

The demonstration of cartilaginous involvement in laryngeal carcinoma by computerized tomography.

Thirty-six patients with laryngeal carcinoma were investigated by computerized tomography (CT). In 8 patients invasion of cartilage was shown at subsequent pathological examination of the excised larynges. In all there were 14 areas of cartilage involvement, 11 of which could be diagnosed on retrospective examination of the CT scans. Involvement of tumour was shown either as areas of decreased density (chondrolysis) or areas of local increased density (chondrosclerosis) due to cartilage ossification. False positive and false negative evidence of cartilage involvement was recorded in the series, but the accuracy of diagnosis in positive terms was approximately 79%. Histological evidence is put forward that the presence of carcinoma in relation to the cartilage produces perichondritis, which enhances ossification and the latter process may then in itself facilitate invasion by the tumour. Previous radiotherapy may also be a factor in the causation of the perichondritis and ossification.

Carcinoma, Squamous Cell↗

Pathology of the intrinsic muscles of the larynx.

The intrinsic muscles of the larynx were exposed in each of 54 normal larynges derived from the autopsy series of a general hospital and submitted to microscopic examination. Muscle fibre alterations were found in all the posterior cricocarytenoid muscles in patients from 13 years of age on wards. In about half of the patients these changes included necrosis of segments of muscle fibres and secondary cellular reactions to this. In two cases of chronic autonomic failure with multiple system atrophy the intrinsic laryngeal muscles were similarly examined. Both cases showed a marked gross and microscopic atrophy of the posterior cricoarytenoid muscles; there were also microscopic changes similar to those found in the normal population. The significance of the changes in the routine post-mortem larynges, the changes in the cases of chronic autonomic failure with multiple system atrophy and the relationship between the two are discussed.

Adolescent↗

Teaching self-management skills to asthmatic children and their parents in an ambulatory care setting.

A program designed to teach self-management skills to asthmatic children and their parents was performed by a nurse-educator utilizing health education techniques. Goals included: (1) reduce frequency and severity of asthma; (2) reduce emergency room visits and hospitalizations; (3) reduce school absenteeism; (4) develop positive family self-help attitudes; and (5) incorporate patient-parent education in an office. After informed consent was obtained, 26 asthmatic children, aged 2 to 14 years, were selected and evaluated. Appropriate asthma management including avoidance, medications, and immunotherapy, if indicated, was initiated for both a study group (13 patients) and a comparison group (13 patients). Symptom and medication diaries were kept for six to 18 months. Educational intervention by a nurse-educator, including four hours of individual instruction, group classes, telephone access, and monitoring for the study patients, resulted in fewer hospitalizations and emergency room visits as compared to control patients, tenfold less school absenteeism, and fewer asthma attacks. Estimated hospital and emergency room costs were much less in the educated group. These results were accomplished by improving comprehension of and compliance with the medical management program by the study patients and their families; more medications were used and therapy for asthma was initiated earlier.

Adolescent↗

Histopathological changes in the temporal bone in kwashiorkor.

The histopathological changes in human temporal bones are described for 2 cases of kwashiorkor--a protein/calorie malnutrition (PCM) state. There is photographic evidence of severe damge to the middle and inner ears and to the vestibulocochlear nerve. The middle ear shows evidence of chronic otitis media, a common clinical finding in kwashiorkor. Significantly, the round window membranes in both cases showed thickening and infiltration with inflammatory cells. The inner ear showed the loss of cellular elements and hair cell loss in the spiral organ. A marked decrease of spiral ganglion cells and demyelination of the vestibulocochlear nerve were also seen.

Adolescent↗

Squamous cell carcinoma of the middle ear.

The clinic features of 28 cases of squamous cell carcinoma of the middle ear are reviewed. Only one patient developed cervical lymph node metastasis and one radiological evidence of pulmonary metastasis. Fourteen of 23 patients (61%) died within 5 years after treatment from intracranial extension of the neoplasm. The pathological findings in three cases in which serially sectioned temporal bones were available are described. An important feature in each case was a penetration by tumour of the bony wall on the medial wall of the middle ear to infiltrate the carotid canal and b penetration by tumour of the thin layer of bone between the posterior mastoid air cells and the dura with subsequent invasion along the dura and into the internal auditory meatus. In one case the cochlea was infiltrated from the latter situation, but direct invasion of the cochlea from the middle ear was not observed. In view of the extensive infiltration that is probably already present at the time of diagnosis, radical surgical procedures are contraindicated.

Adult↗

Examination of the larynx in the histopathology laboratory.

A method is described for examination of the larynx in the histopathology laboratory. Using a slicing machine, transverse slices of the whole larynx are obtained from which representative histological samples may be prepared. This method offers the advantages of a complete gross examination of the normal and pathological structures of the larynx supplemented by histological studies using any of the methods of paraffin embedding, frozen section, plastic embedding, or electron microscopy on any part of the larynx.

Histological Techniques↗

Amyloid in localised deposits and plasmacytomas of the respiratory tract.

Clinical and histological features of 25 cases with amyloid deposits in the respiratory tract are described. The false cord is the commonest single site of such "primary" amyloid involvement. Evidence of extensive involvement and replacement of seromucinous glands by amyloid was seen in each case. Fourteen cases of plasmacytoma with "secondary" amyloid deposits are also described. The nose and nasopharynx were principally involved as with respiratory tract plasmacytomas in general but a similar association of the amyloid with seromucinous glands was also seen. Electron microscopy showed early involvement of the basal lamina of the duct of a seromucinous gland by amyloid in one case. Possible reasons for the association of amyloid precursors in respiratory tract amyloid with seromucinous glands are given.

Adult↗

Cholesterol granuloma of the maxillary antrum.

Five cases of cholesterol granuloma in the maxillary antrum are described. The lesion takes place in the mucosa. It seems likely that filtration and haemorrhage are the 2 main ways in which cholesterol is concentrated in certain tissues. The maxillary antrum provides a clear illustration of these 2 mechanisms at work.

Adult↗

Ambulant management of patients with recent myocardial infarction.

Thirty-two patients who had remained ambulant and active after suffering an acute myocardial infarction were observed for 6 months. Complications were present initially in 11 but proved transient. One patient died of a new coronary thrombosis 15 weeks after the initial episode. There were no recurrences among the 31 surviving patients. After the 6 months all but two patients were as well as before the attack; 21 were free of symptoms and there was no undue incidence of objective findings that could be attributed to failure to rest after the attack. It is therefore concluded that, for patients who suffer an acute myocardial infarction, immediate diagnosis and admission to a coronary care unit need not be equated invariably with immobilization in bed. Our experience suggests that selected patients can be allowed moderate activity without ill effects and thus avoid the undesirable consequences of enforced bed rest.

Acute Disease↗

Otolaryngological disturbances in Waldenstrom's macroglobulinaemia.

Four cases of Waldenstrom's macroglobulinaemia (WM) are described in which otoloaryngeal symptoms were present. Symptoms in WM are related to (a) bleeding diathesis and (b) hyperviscosity of the blood. The bleeding diathesis was manifested as epistaxis in 2 cases. In one case which came to postmortem, histological examination of the temporal bone showed complete disruption of the labyrinth by haemorrhage. Hyperviscosity probably was the source of hearing loss which took place in all 4 patients and had the following characteristics: (a) sudden onset (b) cochlear type (c) bilateral (d) sequential involvement of the two sides (e) improvement on treatment of the disease with alkylating agents or plasmapheresis. Early diagnosis of WM is thus important.

Aged↗

Undifferentiated carcinoma of the nasopharynx: a light and electron microscopical study.

Light microscopical study of 29 cases of undifferentiated carcinoma of the nasopharynx showed evidence or origin of the tumour cells from overlying epithelium in 10 cases. In all cases the tumour cells had a distinctive cellular appearance of 'empty' chromatin deficient nuclei, prominent nucleoli and indefinite cytoplasmic margins. Electron microscopy indicated desmosomes and poorly defined tonofilaments in addition to the above cytoplasmic features. Undifferentiated carcinoma of the nasopharynx shows characteristic light and electron microscopic features which indicate that the tumour cells take origin from squamous epithelium, but are of an extreme degree of dedifferentiation.

Carcinoma↗

Pathology of 'non-healing (midline) granuloma'.

In a histological study of biopsy and postmortem material from 30 cases of nasal disease in which a clinical diagnosis of 'midline granuloma' or Wegener's granuloma had been given, we selected 10 cases on the basis of the presence of widespread coagulative necrosis and atypical cells. Evidence is provided that such changes represent a malignant neoplasm of histiocytic lymphoma type. Local invasion and spread to cervical and more distant lymph nodes, spleen, liver, and kidney were seen in some of the cases. Erythrophagocytic activity was marked in the spleen in three cases and histiocytic infiltration of the bone marrow in two cases, indicating a more generalised activity of histiocytic cells. Terms such as 'malignant granuloma' should be abandoned. In obstructive and ulcerating conditions of the nose efforts should be concentrated on making an accurate histological diagnosis.

Adult↗

Pleionaitema.

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Cardiomegaly↗