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Biomedical subjects

G F Murphy

Publications and source records attributed to G F Murphy.

At least 199 records · Page 11Linked to original sources
PubMed1982

The genesis of paired cisternae during the mitotic cycle.

Paired cisternae, which are conspicuous in mitotically active cells, are two or more flattened, membrane-bound saccules stacked in parallel arrays. The origin, development, and fate of paired cisternae during the cell cycle were studied in a poorly differentiated carcinoma of the eyelid. Early in the mitotic cycle, multiple membrane-bound, ovoid vesicles separated by interconnecting septa formed at the nuclear-cytoplasmic interface coincident with the disappearance of the nuclear envelope. These vesicles became progressively flattened and elongated to form paired cisternae, and by late prophase, had migrated to the cell periphery. During early anaphase, intimate association of paired cisternae with condensing chromosomes was observed. During late anaphase and telophase, distension of the cisternae resulted in vesicles similar to those observed in prophase cells. An apparent coalescence of these distended vesicles around the aggregated chromatin of daughter cells resulted in newly formed nuclear envelopes. Paired cisternae appear to be specialized nuclear membrane-derived structures that are fundamental in the generation of nuclear membranes of daughter cells. An infrequently observed variant of paired cisternae, subsurface confronting cisternae, is briefly described.

Aged↗
PubMed1981

Diffuse melanosis secondary to metastatic malignant melanoma. Light and electron microscopic findings.

Tumor-free hyperpigmented skin from a patient with diffuse melanosis secondary to metastatic melanoma was examined by light and electron microscopy. Our findings indicate that the pathogenesis of this diffuse slate blue color is primarily to pigment deposition within perivascular dermal macrophages. We did not find intact melanosomes or individual tumor cell metastases in clinically normal skin, as has been previously reported.

Adult↗
PubMed1981

Ultrastructural and x-ray microanalytical observations of minocycline-related hyperpigmentation of the skin.

In order to elucidate the nature and distribution of the pigment responsible for the circumscribed blue-black cutaneous hyperpigmentation occurring after administration of minocycline hydrochloride, transmission electron microscopy and energy-dispersive electron x-ray microanalysis were performed on lesional skin. Ultrastructural observations demonstrated electron-dense iron-containing particles either incorporated into a variety of siderosomes, within dermal histiocytes, free within the cytoplasm, or, rarely, scattered among dermal collagen fibers. Electron x-ray microanalysis confirmed iron content present within these particles. Although siderosomal inclusions contained occasional melanosome complexes, the degree of deposition of electron-dense iron-containing particles in dermal histiocytes seemed to be primarily responsible for the blue-black discoloration of the skin. The present study is an investigation of the structure and composition of the pigment responsible for minocycline-related cutaneous hyperpigmentation.

Adolescent↗
PubMed1981

T cell subsets and Langerhans cells in lichen planus: in situ characterization using monoclonal antibodies.

Skin biopsies from four patients with lichen planus were studied using monoclonal antibodies directed against T lymphocytes. Anti-TI and anti-T3 antibodies, which react with all peripheral T cells, stained most cells in the dermal infiltrates. The majority of infiltrating cells also stained with anti-T4 and anti-T4b antibodies, which react with helper/inducer cells, whereas a minority of cells stained with anti-T8 antibody, which reacts with cytotoxic/suppressor cells. Surface IgM was not identified on any infiltrating cells, providing evidence against B cell participation. Intraepidermal and dermal cells with long cytoplasmic extensions stained with any anti-T6 antibody in all cases, defining them as Langerhans cells or their precursors. T6-positive cells were seen in greater number than in normal control epidermis and dermis. The results indicate that well-developed lesions of lichen planus are characterized by an influx of helper/inducer T lymphocytes and increased numbers of Langerhans cells. These observations support the contention that cellular immunity is important in the pathogenesis of this disorder.

Antibodies, Monoclonal↗
PubMed1981

Characterization of Langerhans cells by the use of monoclonal antibodies.

Intraepidermal dendritic cells react with the monoclonal antibody, anti-T6, which also reacts with a majority of cortical thymocytes but not with mature T lymphocytes. Application of a four-step peroxidase antiperoxidase technique and immunoelectron microscopy to normal human epidermis demonstrates that T6 antigen is present on the cell surface of Langerhans cells but not on keratinocytes or melanocytes. These data suggest that T6 antigen is an important marker for Langerhans cells.

3,3'-Diaminobenzidine↗
PubMed1981

Microvascular injury in lymphomatoid granulomatosis involving the skin. An ultrastructural study.

An electron microscopic study of a cutaneous lesion of lymphomatoid granulomatosis taken from a patient with pulmonary involvement was performed. Microvascular alterations ranged from mild, degenerative changes to vessel necrosis. Less severe changes included enlarged endothelial cells, with margination of small lymphoid cells in affected vessels. Luminal occlusion by necrotic endothelial cell fragments and fibrin was associated with thickening and reduplication of the basal lamina and an angiocentric, inflammatory infiltrate in severely affected vessels. The most frequently observed cells in the infiltrate were cleaved and noncleaved lymphocytes that exhibited notable cytolysis and degenerative changes in cytoplasmic organelles. We conclude that lymphomatoid granulomatosis involving the skin is a disorder in which substantial numbers of cleaved and noncleaved lymphoid cells participate, eventuating in small-vessel necrosis and occlusion and repeated endothelial cell regeneration.

Aged↗
PubMed1980

Exfoliation of respiratory epithelium in hamster tracheal organ cultures infected with Mycoplasma pneumoniae.

Hamster tracheal organ cultures were infected with M. pneumoniae and examined sequentially by transmission and scanning electron microscopy to correlate surface with intracellular alterations. Infection was established by culture and the demonstration of morphologically compatible organisms on the mucosal surface. Ciliated epithelial cells developed vacuolization of the apical and subnuclear cytoplasm and eventually fragmented along planes formed by coalescing vacuoles. Non-ciliated cells showed apical swelling and loss of microvilli during the course of infection. After degeneration and sloughing of both ciliated and non-ciliated cells, a flattened layer of intact basal cells covered the submucosa. It is likely that progressive vacuolization of epithelial cells leads to exfoliation of both cells and cell fragments in M. pneumoniae infection. Since organisms frequently are associated with these exfoliated cells, their potential presence in sputum and lavage specimens could prove to be of diagnostic importance.

Animals↗
PubMed1980

Carcinoid tumor of the middle ear.

A primary tumor of the middle ear with histologic, histochemical, and ultrastructural features of a neuroendocrine neoplasm is described. This neoplasm superficially resembles the so-called adenomatous tumor of the middle ear, and potential relationships and differences between these tumors are discussed. Although the histogenesis of the carcinoid tumor of the middle ear is not well understood, it most likely originates from pre-existing neuroendocrine cells or a primitive precursor cell. This neoplasm should be considered in the differential diagnosis when biologically low-grade tumors with prominent acinar or trabecular architectures are encountered in the middle ear. Since the carcinoid tumor of the middle ear is presumably of foregut derivation, stains for argyrophilic granules and electron-microscopic identification of neurosecretory granules are important diagnostic aids.

Adenocarcinoma↗
PubMed1980

Oral warty dyskeratoma.

An elderly woman had a small verrucose hyperkeratotic papule on the hard palate. Histologic examination showed the lesion to be a warty dyskeratoma. Warty dyskeratoma may represent an abnormal keratinization response to intraoral trauma or inflammation. All eight previously reported cases are reviewed. Clinically, the lesions appeared as verrucose hyperkeratotic papules or as focal mucosal depressions, sometimes filled with keratin. Eight of nine lesions were located on the hard palate or on an alveolar ridge.

Aged↗
PubMed1979

Relationship between survival and histologic type in small cell anaplastic carcinoma of the lung.

Survival and histologic subtype were compared in 61 patients with small cell anaplastic lung cancer. Patients with lymphocyte-like (oat cell) and fusiform histologies treated with chemotherapy had longer median survivals than the polygonal and other varieties on the same treatment. Likewise, when detectable disease was confined to the chest and supraclavicular nodes, the patients with lymphocyte-like and fusiform types lived longer. The improved survival in the lymphocyte-like and fusiform categories accounted for most of our improved overall median survival rates with the COPP regimen in small cell lung cancer. Survival in the polygonal and other types was not appreciably different from that seen in non-small cell lung cancer (squamous and adenocarcinoma). It may be possible to refine treatment plans on the basis of cell type so as to further increase survival in small cell anaplastic lung carcinoma.

Antineoplastic Agents↗
PubMed1979

Esophageal-atrial perforation due to recurrent esophagitis 18 years after esophageal bypass surgery.

A 62-year-old man presented with a grand mal seizure, progressive abdominal distention, and refractory hypotension 18 years after colonic bypass of a benign stricture of the low middle third of the esophagus. He died 3 hours after admission to the hospital. The patient had a history of liniment ingestion in childhood plus a long history of dysphagia and substernal pain. Autopsy disclosed a large ulcer of the anterior wall of the distal esophagus, which had eroded through the posterior wall of the left atrium. Histologic examination revealed chronic esophagitis with fibrous obliteration of the esophageal wall, pericardium, and left atrial myocardium near the site of perforation. Foreign material was present within small arteries of multiple viscera, and in several of these fragments transverse striations were demonstrated. Esophageal-atrial perforation is a rare but fatal complication of chronic esophageal ulceration. The clinical and pathological features of this and previously reported cases of nontraumatic esophageal-atrial perforation are reviewed.

Esophageal Fistula↗
PubMed1979

Brenner tumor and mucinous cystadenoma of borderline malignancy in a patient with Turner's syndrome.

A 64-year-old woman with a 45,X karyotype and Turner's syndrome and recent onset of right lower quadrant pain was found to have a mucinous cystadenoma with focal areas of borderline malignancy and a typical Brenner tumor in the right adnexa. Ovarian tumors in patients with a 45,X karyotype and Turner's syndrome are extremely rare. The present paper is the first report of concurrence of these 2 tumors in an affected individual. The simultaneous occurrence and intimate admixture of these tumors in a patient believed to be devoid of germ cells would seem to favor a common histogenesis from the germinal epithelium.

Adnexal Diseases↗
PubMed1978

The equivalent conductivity of aqueous solutions of alkali metal salts of a number of ionic polysaccharides.

Measurements of the equivalent conductivity of aqueous solutions of alkalimetal salts of a number of ionic polysaccharides at 25 degrees C are reported. The polysaccharides studied are: (1) three carboxymethylcelluloses of various degrees of substitution (Li+, Na+, Cs+ salts) in the concentration range 4 X 10(-4) - 6 X 10(-2) equivalents alkali ion per liter, (2) Polypectate (Li+, Na+, K+, Cs+ salts) in the range 1.5 X 10(-4) - 2 X 10(-2) equivalent alkali ion per liter, and (3) Dextransulfate (Li+, Na+, K+ salts) in the range 3 X 10(-4) - 10(-1) equivalent alkali ion per liter. The results are compared to some earlier data and to a limiting law for conductance of rod-like polyions derived by Manning. It is concluded that although qualitative agreement is obtained between observed data and the limiting law when various polyions of different charge densities are compared at a given concentration, the concentration dependence predicted by the limiting law is in agreement with the observed curves only for polyions of a relatively low charge density. At higher charge densities appreciable deviations occur, and dextransulfate which does not have the rod-like polyion structure required by theory does not conform to the predicted concentration dependence at all.

Carboxymethylcellulose Sodium↗
PubMed1978

Radioimmunoassay for serum tobramycin levels using 125I-labeled tobramycin.

A radioimmunoassay is described for the measurement of tobramycin in serum or plasma. The technique has advantages over other assay techniques with regard to precision, specificity, sensitivity and rapidity. The radioimmunoassay uses a tracer labelled with 125Iodine. The iodination technique is simple and gives tracer in high yield, at high specific activity and with complete immunological identity to unlabelled tobramycin. There is a significant correlation between the results obtained by this radioimmunoassay and by the disc-plate assay. Such knowledge of serum levels of tobramycin assists the clinician in regulating drug dosage to obtain an optimum therapeutic effect, and yet avoids toxic serum levels.

Acylation↗