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Biomedical subjects

G F Murphy

Publications and source records attributed to G F Murphy.

At least 127 records · Page 7Linked to original sources
PubMed1989

Evidence that large granular lymphocytes of donor origin mediate acute graft-versus-host disease.

We have studied the phenotype of mononuclear cells infiltrating target organs of mice with acute graft-versus-host disease after bone marrow transplantation from H-2-identical donors. Infiltrating mononuclear cells with characteristics of large granular lymphocytes (LGL) were frequently found in close association with dead or dying epithelial cells in the skin, liver, and colon. The phenotype of these putative effector cells was Thy-1+, ASGM1+, Mac-1+, Lyt-1-, Lyt-2-, Ia-, which is characteristic of LGL. Differences in the Thy-1 allele between donor and host were used to demonstrate that these cells were of donor origin. Analysis of cytolytic function in GVHD splenocytes indicated high natural killer activity and low cytolytic T lymphocyte (CTL) activity. These findings suggest that an important effector cell in systemic acute graft-versus-host disease is a large granular lymphocyte of donor origin.

Animals↗
PubMed1989

Intercellular adhesion molecule expression in the evolving human cutaneous delayed hypersensitivity reaction.

Intercellular adhesion molecule-1 (ICAM-1), putatively expressed by antigen-presenting or target skin cells, is a ligand for the lymphocyte function-associated antigen (LFA-1) present on circulating lymphocytes. Immunohistochemistry of normal adult human skin using monoclonal antiserum to ICAM-1 demonstrated focal reactivity restricted to endothelium lining the dermal microvasculature. Delayed hypersensitivity responses elicited with dinitrochlorobenzene in the skin of the same subject were evaluated sequentially over a 96 h period using immunohistochemical and ultrastructural techniques. The first alteration observed consisted of mast cell degranulation within perivenular foci in the superficial dermis at 4 h after antigen challenge. Sparse superficial perivascular T-cell infiltrates were present by 24 h. Progressive staining for ICAM-1 was observed in microvascular endothelium and in dermal dendritic cells between 24 and 48 h. ICAM-1 expression was documented focally within the lower epidermis at 48 h and diffusely within the lower and upper epidermal layers at 96 h. ICAM-1 expression by keratinocytes was consistently associated with T-cell migration into the epidermis, whereas migration was never observed in the absence of ICAM-1 reactivity. Immunoelectron microscopy confirmed ICAM-1 to be exclusively present on endothelial cells, dermal dendritic cells, mononuclear cells, and keratinocytes, and permitted characterization of the patterns of membrane reactivity. ICAM-1 expression by epidermal cells appears to be closely linked to the progressive migration of T cells from the dermis into the epidermis that characterizes cutaneous delayed hypersensitivity.

CD4-Positive T-Lymphocytes↗
PubMed1989

Special techniques in dermatology.

Beyond routine hematoxylin-eosin histologic examinations, specialized diagnostic techniques allow examination of biopsy material for subtle morphological and functional alterations. Morphological analytic techniques (1-micron section analysis, transmission electron microscopy, x-ray probe microanalysis, and digital image analysis) and functional analytic techniques (immunofluorescence, immunohistochemistry, and molecular biologic techniques) are valuable diagnostic tools. These techniques have applications in evaluating cutaneous T-cell lymphoma and atypical lymphocytic infiltrates, vesiculobullous disorders, lupus erythematosus and collagen vascular diseases, vasculitis, poorly differentiated tumors, storage diseases, and infections.

Dermatology↗
PubMed1988

Histologic reporting of malignant melanoma.

The schema for histologic reporting of malignant melanoma outlined above is incomplete. A number of variables, including quantification of tumor cell pigmentation, description of solar degeneration in surrounding stroma, and extent of S-100 protein immunoreactivity by tumor cells, have not been addressed. In addition, it is likely that within the next several years, additional parameters, including those identified by the use of in situ genomic probes (Chapter 3), will become known to confer prognostic information when assessed histologically in biopsy material. Nonetheless, this approach represents a start, an attempt to achieve uniformity in histologic reporting of melanoma. It represents a three-tiered approach. First is the establishment of a malignant melanocytic lesion (malignant melanoma) and the assessment of the anatomic level and extent of invasion of the dermis, which correlates directly with metastatic potential (the vertical growth phase measured in millimeters). Subclassification of the radial growth phase is optional and, by convention, is also reported in this "above the line" portion of the diagnostic assessment. Second, a number of subsidiary diagnostic statements, usually in the form of notes or comments, are recommended. These include assessment of overlying epidermal ulceration, a description of the morphology and mitotic activity of the vertical growth phase nodule, an assessment of the presence or absence of vascular invasion and microscopic satellite formation, a description of the host mononuclear cell response and/or regression, and mention of associated pathology. Finally, an additional narrative statement may be included to describe such things as extent of S-100 immunoreactivity or to modify in a more descriptive manner the database provided above. Although this last category is neither crucial nor mandatory, it serves to add to a collective database from which future determinations concerning the prognostic significance of new histologic parameters may be formulated. Table 6.3 provides a sample report based on the above considerations. This method of histologic reporting is recommended because it includes important diagnostic information as well as parameters for prognosis. Although certain details of less impelling current significance are included, these are of potential future importance as a greater number of patients with malignant melanoma are followed prospectively for prolonged periods of time. These factors may also prove to be significant in the accumulation of a database for research.

Epidermis↗
PubMed1988

Ultrastructure and dynamics of selective mitochondrial injury in carcinoma cells after doxycycline photosensitization in vitro.

Mechanisms and intracellular sites of photosensitized damage were investigated in cultured MGH-U1 cells treated with doxycycline (DOTC). Cells were examined by phase-contrast, fluorescence, and electron microscopy at various times (15 minutes to 24 hours) after ultraviolet irradiation (320-400 nm). DOTC localized selectively within the mitochondria, as shown by colocalized fluorescence with rhodamine 123 (R123). Photosensitization at 1 J/sq cm caused striking swelling of the mitochondrial matrix and disruption of the cristae, accompanied by loss of the ability of mitochondria to concentrate R123. These changes progressed during the first hour after irradiation, and then were followed by partial recovery of mitochondrial ultrastructure and function. At no time were other organelles seen to be affected. It appears that this selective, photosensitized alteration was a consequence of localized and partially reversible damage to the mitochondrial inner membrane. In contrast, exposure to 2-6 J/sq cm caused irreversible injury and necrosis.

Doxycycline↗
PubMed1988

Effects of recombinant gamma-interferon on HLA-DR and DQ expression by skin cells in short-term organ culture.

We studied the effects of various immunologic and inflammatory mediators on the expression of the class II major histocompatibility antigens, HLA-DR and DQ in short-term organ cultures of newborn human foreskin. Induction of these molecules above baseline was observed preponderantly on microvascular endothelium and epidermal dendritic cells, and among the mediators tested, this induction was caused exclusively by immune interferon. Increased reactivity for HLA-DR and DQ was observed at 24 hours for both cell types. Double labeling confirmed that the HLA-DR/DQ-positive dendritic cell population consisted largely of T6-positive Langerhans cells. Peak endothelial HLA-DR expression was seen at 24 hours and slowly dissipated thereafter. In contrast, endothelial HLA-DQ showed increasing expression over 72 hours of the study. Keratinocytes remained unreactive for HLA-DR and DQ during the entire study period. We conclude that class II major histocompatibility molecules can be modulated on skin microvascular endothelial cells and Langerhans cells in situ by immune interferon with response rates different from those previously described for endothelium in cell culture. Furthermore, the organ culture system has revealed keratinocyte unresponsiveness not anticipated from cell culture experiments. These findings have implications for the effector function and potential targeting of these cells in the cutaneous immune response, and establishes short-term organ culture of human skin as a valuable model for assessment of interactions between cytokines and skin cells.

Antigens, Differentiation, T-Lymphocyte↗
PubMed1987

Induction of an activation antigen on postcapillary venular endothelium in human skin organ culture.

We studied the effects of the immune mediators interleukin 1, interleukin 2, tumor necrosis factor, immune interferon, and lipopolysaccharide on the expression of the endothelial activation antigen recognized by the murine monoclonal antibody H4/18 in short term organ cultures of newborn foreskins. No endothelial staining was detectable before culture. Interleukin 1, tumor necrosis factor, and lipopolysaccharide each induced 2+ to 3+ H4/18 staining of microvascular endothelium at 6 hr. Combining mediators produced additive (3+ to 4+) effects, and reactivity was lost or markedly diminished by 24 hr. Incubation with culture medium alone resulted in 1+ to 2+ H4/18 staining at 6 hr, and medium conditioned by cultured foreskins, but not mock-conditioned medium, could induce H4/18 binding in cultured human umbilical vein endothelial cells. The spontaneous expression of microvascular staining in the foreskins was markedly inhibited by cyclosporin A, but not polymyxin B sulfate or dexamethasone; cyclosporin A did not inhibit induction of staining by exogenous mediators. Both light level and immunoultrastructural studies demonstrated H4/18 expression to be associated predominantly with postcapillary venular endothelial cells of the superficial vascular plexus. We conclude that microvascular endothelium of skin can undergo activation in response to exogenous and endogenous cytokines, with the greatest changes occurring in those portions of the vessels most involved in leukocyte and lymphocyte trafficking.

Animals↗
PubMed1987

Epidermal cells in activation of suppressor lymphocytes: further characterization.

Intravenous administration of hapten-coupled, high-density (density greater than 1.077) epidermal cells (HD-EC) to mice results in the appearance of transferable splenic T suppressor (Ts) cells as assayed in adoptive transfer experiments. Depletion of I-A bearing cells from the HD-EC population before hapten coupling prevents these cells from inducing Ts cell formation, whereas depletion of Thy-1-bearing cells from the HD-EC cell preparation has no effect. When HD-EC are adhered to glass for 2 hr, the ability to induce Ts cell formation resides in the adherent population. Exposure of HD-EC to a dose of ultraviolet radiation (UVR) that largely abrogates the ability of hapten-coupled EC to immunize mice for a DTH response does not affect the ability of these cells to activate Ts cells. Treatment of mice with i.p. administration of 20 mg/kg of cyclophosphamide 2 days before EC harvesting abrogates the ability of HD-EC from these mice to induce Ts cell formation. HD-EC from B10.A(3R) (I-Jb) but not B10.A(5R) (I-Jk) mice induce Ts cell formation in B10.A(3R) mice, demonstrating that the ability to do so is restricted by the I-J locus. Transmission electron microscopy of adherent HD-EC populations demonstrated that two cell types were present. One type had the characteristics of keratinocytes; the other was monocyte-like and resembled Langerhans cells or indeterminate cells in many aspects. Immunoelectron microscopy revealed this second cell type to bear I-A/I-E antigen. These cells were T-200 positive and Mac-1 negative by immunoperoxidase staining. Extensive examination by light and electron microscopy failed to reveal any dermal components in the EC populations; however, a very small degree of dermal contamination cannot be excluded. Thus, EC that activate afferent-acting Ts cells are high-density, I-A+, Thy-1-, I-J restricted, glass adherent, and functionally UVR resistant and cyclophosphamide sensitive.

Animals↗
PubMed1987

Involucrin as a diagnostic marker in oral lichenoid lesions.

Thirty-eight biopsy specimens were examined for involucrin reactivity by an immunoperoxidase technique. The sampling consisted of specimens diagnosed as normal oral mucosa, reactive epithelial hyperplasia, lichen planus (LP), nonspecific lichenoid stomatitis (NLS), lichenoid dysplasia (LD), carcinoma in situ, and squamous cell carcinoma (SCCa) on routine hematoxylin and eosin examination. Findings were consistent with prior observations of involucrin reactivity in skin and cervical-vaginal mucosa. Specifically, conditions characterized by predominance of mature squamous epithelial cells (superficial layers of normal and hyperplastic oral epithelium, NLS, and LP) exhibited strong involucrin reactivity in such areas. In contrast, atypical or dysplastic lichenoid lesions (LD), as well as carcinoma in situ, despite squamoid differentiation, demonstrated irregular distribution of involucrin, suggesting disturbances in terminal differentiation. Invasive components of SCCa revealed markedly diminished involucrin expression. These findings support prior evidence that LP and LD are biologically distinct lesions. Clinically and microscopically, both may be morphologically similar. However, involucrin reactivity should be helpful in distinguishing difficult cases. Accordingly, we suggest that the use of involucrin immunoreactivity may prove to be a valuable adjunct in the separation of similar lichenoid oral conditions.

Carcinoma, Squamous Cell↗
PubMed1987

Morphologically distinctive forms of cutaneous mast cell degranulation induced by cold and mechanical stimuli: an ultrastructural study.

To determine whether morphological differences in the response of cutaneous mast cells characterize clinically distinct forms of urticaria, we used ultrastructural techniques to examine skin biopsy specimens from three patients with cold-induced urticaria and four patients with dermographism. Biopsy specimens were obtained before application of the stimulus and at the time of lesion formation. Patients with cold-induced urticaria exhibited morphological alterations only after stimulus application consisting of enlargement and uniform disorganization of some, but not all, granules, fusion of the membranes of adjacent granules, fusion of granule membranes with mast cell membranes, and discharge of electron-lucent and disorganized granule contents into the extracellular space. Mast cells from patients with immediate as well as delayed dermographism exhibited alterations before and after stimulus application consisting of enlargement of most granules, nonuniform (zonal) disorganization or solubilization of granule contents, fusion of granule membranes with mast cell membranes, and extracellular discharge of granule contents. Small cytoplasmic vesicles containing disorganized granular material were associated with the degranulation process. Endothelial cells lining nearby postcapillary venules exhibited prominent perinuclear condensation of contractile microfilaments during degranulation in both groups. Both before and after application of the stimulus, the walls of the superficial dermal vessels of the patients with dermographism were thinner and contained less extracellular matrix material than vessel walls of the patients with cold-induced urticaria. The morphologically distinctive types of mast cell degranulation that characterize these two clinically separable urticarial disorders may indicate different pathogenic mechanisms of lesion formation.

Adolescent↗
PubMed1987

Ultrastructure: effects of melanin pigment on target specificity using a pulsed dye laser (577 nm).

It has been shown recently that brief pulses of 577 nm radiation from the tunable dye laser are absorbed selectively by oxyhemoglobin. This absorption is associated with highly specific damage to superficial vascular plexus blood vessels in those with lightly pigmented (type I-II) skin. To determine whether pigmentary differences in the overlying epidermis influence this target specificity, we exposed both type I (fair) and type V (dark) normal human skin to varying radiant exposure doses over 1.5-microsecond pulse durations from the tunable dye laser at a wavelength of 577 nm. Using ultrastructural techniques, we found in type I skin that even clinical subthreshold laser exposures caused reproducible alterations of erythrocytes and adjacent dermal vascular endothelium without comparable damage to the overlying epidermis. In contrast, degenerated epidermal basal cells represented the predominant form of cellular damage after laser exposure of type V skin at comparable doses. We conclude that epidermal melanin and vascular hemoglobin are competing sites for 577 nm laser absorption and damage, and that the target specificity of the 577 nm tunable dye laser is therefore influenced by variations in epidermal pigmentation. This finding is relevant to the clinical application of the tunable dye laser in the ablative treatment of vascular lesions. We also found on ultrastructure that the presence of electron-lucent circular structures of approximately 800 A in diameter were observed only at and above clinical threshold doses in those with type I skin and at the highest dose of 2.75 J/cm2 in type V skin. It has been proposed that these structures might be heat-fixed molds of water vapor. Both this and ultrastructural changes of epidermal basal cells demonstrate mechanisms responsible for alteration of tissue after exposure to 577 nm, which are discussed.

Animals↗
PubMed1987

Melanosomes are a primary target of Q-switched ruby laser irradiation in guinea pig skin.

The specific targeting of melanosomes may allow for laser therapy of pigmented cutaneous lesions. The mechanism of selective destruction of pigmented cells by various lasers, however, has not been fully clarified. Black, brown, and albino guinea pigs were exposed to optical pulses at various radiant exposure doses from a Q-switched, 40 nsec, 694 nm ruby laser. Biopsies were analyzed by light and electron microscopy (EM). Albino animals failed to develop clinical or microscopic evidence of cutaneous injury after irradiation. In both black and brown animals, the clinical threshold for gross change was 0.4 J/cm2, which produced an ash-white spot. By light microscopy, alterations appeared at 0.3 J/cm2 and included separation at the dermoepidermal junction, and the formation of vacuolated epidermal cells with a peripheral cytoplasmic condensation of pigment. By EM, enlarged melanosomes with a central lucent zone were observed within affected epidermal cells at 0.3 J/cm2. At 0.8 and 1.2 J/cm2, individual melanosomes were more intensely damaged and disruption of melanosomes deep in the hair papillae was observed. Dermal-epidermal blisters were formed precisely at the lamina lucida, leaving basal cell membranes and hemidesmosomes intact. Possible mechanisms for melanosomal injury are discussed. These observations show that the effects of the Q-switched ruby laser are melanin-specific and melanin-dependent, and may be useful in the selective destruction of pigmented as well as superficial cutaneous lesions.

Animals↗
PubMed1987

Gamma-interferon inhibits collagen synthesis in vivo in the mouse.

Subcutaneous implantation of osmotic pumps into CAF1 mice resulted in the formation of thick fibrous capsules around the pumps. When pumps were loaded with recombinant murine gamma-interferon (rMuIFN-gamma) to deliver 2 X 10(3) U/h for 14 d, there was a marked decrease in thickness and collagen content of the capsules from rMuIFN-gamma-treated animals compared with capsules from animals receiving diluent alone. The collagen content of the capsules was estimated by hydroxyproline analysis of the tissue and by quantitative electron microscopy of collagen bundles. Heat-inactivated rMuIFN-gamma failed to reduce the fibrotic response in this assay. These results provide compelling evidence that gamma-interferon can down-regulate collagen synthesis in vivo and suggest the possibility that this lymphokine may be useful in the treatment of disease states characterized by excessive fibrosis.

Animals↗