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Biomedical subjects

C J Emerson

Publications and source records attributed to C J Emerson.

7 recordsLinked to original sources

Ultrastructure of the spermatozoa and eggs of the ocean pout (Macrozoarces americanus L.), an internally fertilizing marine fish.

Ultrastructure of sperm and eggs of the ocean pout (Macrozoarces americanus L.), an internally fertilizing marine teleost, was examined by scanning and transmission electron microscopy. The results showed that the sperm do not have an acrosome but have a very long mid-piece (one to two times the sperm head length) containing numerous well-developed elongated mitochondria. The sperm also have two tails (is biflagellate) each consisting of nine peripheral and one central pair (9 +/- 2) of microtubules. This long mid-piece and the biflagellate nature of the sperm appear to be associated with the long life-span of the sperm and with sperm dispersal in the ovary to fertilize the eggs internally. The ocean pout eggs are enveloped by a porous chorionic membrane similar to that found in other teleosts but have two micropyles, a condition likely related to a mechanism of egg fertilization which increases the egg fertility in the presence of low sperm numbers. Following insemination, some biochemically undefined excretions appeared on the surface of fertilized eggs and led to the acquisition of adherent capability of the eggs which formed a tightly associated egg mass in sea water.

Animals↗

Transbronchial lung biopsy with the fibreoptic bronchoscope: analysis of results in 433 patients.

Transbronchial lung biopsy was performed via the fibreoptic bronchoscope in 433 patients. In 183 patients, whose chest radiographs showed bilateral diffuse shadows a histologic diagnosis was established by transbronchial biopsy in 61%, including sarcoidosis (58), fibrosing alveolitis (18) and carcinoma (14). Histologically normal lung or inadequate pulmonary tissue for diagnosis was obtained from 71 patients in this group. In 225 patients with solitary chest radiography opacity, a diagnosis of bronchial carcinoma was finally made in 130, of whom 82 (63%) had a histological diagnosis established by transbronchial biopsy. In 84 patients finally shown to have sarcoidosis, 65 (77%) had positive histology by transbronchial biopsy whereas only 19 (40%) of 48 patients with fibrosing alveolitis yielded histology compatible with the diagnosis. Pneumothorax developed in three patients after the procedure but only one required intercostal drainage. Haemorrhage of 50-100 ml occurred in seven patients and bleeding ceased spontaneously in all cases. There were no fatalities.

Adolescent↗

Fibreoptic bronchoscopy: ten years on.

Fibreoptic bronchoscopy was introduced more than 10 years ago and is now in many centres a routine diagnostic procedure, having superseded rigid bronchoscopy. Its major role is in the diagnosis of bronchial carcinoma, where the results are as good as, if not better than, results with the rigid instrument. Other major applications have been found in investigating haemoptysis, transbronchial lung biopsy in interstitial lung disease, and in the critically ill patient in the intensive care unit. More recently, the instrument has been used to perform bronchoalveolar lavage in investigating interstitial lung diseases and to enable lobar and segmental lung function studies to be performed. Fibreoptic bronchoscopy is a major advance in the diagnosis of pulmonary diseases, but there will always be times when rigid bronchoscopy is preferable.

Adolescent↗

Transbronchial lung biopsy through fibreoptic bronchoscope in diagnosis of sarcoidosis.

Sarcoidosis was ultimately diagnosed in a consecutive series of 79 patients, of whom 24 presented with unusual features. Histological support for this diagnosis was obtained in 37 out of 42 patients who underwent transbronchial biopsy; epithelioid and giant-cell granulomas were also found on biopsy of the bronchial mucosa in 17 out of 22 patients. Kveim tests were completed in 44 patients: results were positive in 19, equivocal in 11, and negative in 14. In 16 patients histological support was obtained on biopsy of various other tissues. The clinical presentation of the disease and the degree of histological support provided by the various procedures used in reaching a diagnosis of sarcoidosis varied considerably. Transbronchial biopsy of the lung is a useful advance in diagnosing sarcoidosis and provided a higher diagnostic yield than any other method.

Biopsy↗

Scanning electron microscopic observations on the inner ear of the skate, Raja ocellata.

The inner ear of the skate, Raja ocellata, was examined by scanning electron microscopy. The otolithic membranes have a gelatinous component and an endogenous class of otoconia. Cupulae are reticulate in form. The morphology and polarization of sensory cell hair bundles are described for the various regions of the labyrinth, and are compared with published observations on other species. In the otolithic maculae, the more centrally located receptor cells generally have longer sterecolia than the peripheral cells. The hair bundles of the lacinia are similar to those of the central portion of the sacculus and differed from those of the rest of the utricular macula. Hair bundles in the peripheral regions of all maculae and cristae are similar. The polarization pattern of the utriculus is similar to that of teleosts, while that of the lagena is less clearly dichotomized. The receptor cells of most of the sacculus are oriented in a bivertical direction, with cells in the anterior portion, and a few in the posterior region, being aligned longitudinally. The significance of morphology and polarization with respect to the functions of the otolithic organs is discussed. The relationship of cell processes of the ampullary receptors to the cupula is briefly considered.

Acoustic Maculae↗

Techniques utilizing real time stereo scanning electron microscopy in the microdissection of biological tissues.

The use of the scanning electron microscope (SEM) for the microdissection of biological tissue is described. The dissections were accomplished by the use of electrolytically pointed needles that were positioned in a simply constructed holder. The operations were viewed using real time stereo SEM, and recorded on videotape. Various methods for photographing the videotape recordings are outlined.

Data Display↗

Cupula-receptor cell relationships with evidence provided by SEM microdissection.

Ampullae from the inner ear of the skate, Raja ocellata, were examined by SEM to further elucidate the relationships of the sensory hairs of the receptor cells to the overlying cupula. Specimens were prepared by a variety of methods and were fractured to visualize these relationships. Critical point drying resulted in good cellular and sensory hair preservation, but the cupulae were grossly shrunken. Freeze-dried cupulae, in contrast, more closely approximated the in vivo condition. Although tissues suffered freezing damage, sensory hair bundles were readily discerned. In both critical point dried and freeze-dried ampullae, the peripheral hair cell bundles and the kinocilia of most of the central hair cells, extended across the subcupular space and contacted the cupular material. Some of the specimens were further investigated by dissection in the SEM, the process being viewed in real time stereo. Microdissection confirmed that most kinocilia were attached to the cupula. When the cupula was displaced, sensory hair bundles remained attached to it and broke preferentially at their base from the receptor cells.

Animals↗