Noninvasive, visual examination for the presence of gunshot residue on human skin

1973 ◽

Vol 31 ◽

pp. 328-329

Author(s):

John A. Trotter

Keyword(s):

Red Blood Cells ◽

Analytical Method ◽

Blood Cells ◽

Guinea Pigs ◽

Specific Protein ◽

Visual Examination ◽

Hemoglobin Synthesis ◽

Peroxidatic Activity ◽

Small Density

Hemoglobin is the specific protein of red blood cells. Those cells in which hemoglobin synthesis is initiated are the earliest cells that can presently be considered to be committed to erythropoiesis. In order to identify such early cells electron microscopically, we have made use of the peroxidatic activity of hemoglobin by reacting the marrow of erythropoietically stimulated guinea pigs with diaminobenzidine (DAB). The reaction product appeared as a diffuse and amorphous electron opacity throughout the cytoplasm of reactive cells. The detection of small density increases of such a diffuse nature required an analytical method more sensitive and reliable than the visual examination of micrographs. A procedure was therefore devised for the evaluation of micrographs (negatives) with a densitometer (Weston Photographic Analyzer).

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A web-like network of type vi collagen in human skin is revealed by immuno-electron microscopy

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100103978 ◽

1988 ◽

Vol 46 ◽

pp. 382-383

Author(s):

Douglas R. Keene ◽

Robert W. Glanville ◽

Eva Engvall

Keyword(s):

Electron Microscopy ◽

Monoclonal Antibody ◽

Human Skin ◽

Basement Membranes ◽

Primary Antibody ◽

Fat Cells ◽

Secondary Antibody ◽

Type Vi Collagen ◽

Dermal Matrix ◽

Immuno Electron Microscopy

A mouse monoclonal antibody (5C6) prepared against human type VI collagen (1) has been used in this study to immunolocalize type VI collagen in human skin. The enbloc method used involves exposing whole tissue pieces to primary antibody and 5 nm gold conjugated secondary antibody before fixation, and has been described in detail elsewhere (2).Biopsies were taken from individuals ranging in age from neonate to 65 years old. By immuno-electron microscopy, type VI collagen is found to be distributed as a fine branching network closely associated with (but not attached to) banded collagen fibrils containing types I and III collagen (Fig. 1). It appears to enwrap fibers, to weave between individual fibrils within a fiber, and to span the distance separating fibers, creating a “web-like network” which entraps fibers within deep papillary and reticular dermal layers (Fig. 2). Relative to that in the dermal matrix, the concentration of type VI collagen is higher around endothelial basement membranes limiting the outer boundaries of nerves, capillaries, and fat cells (Fig. 3).

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Effect of Acetone and Kerosene on Skin Ultrastructure

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100093717 ◽

1972 ◽

Vol 30 ◽

pp. 92-93

Author(s):

A. P. Lupulescu ◽

H. Pinkus ◽

D. J. Birmingham

Keyword(s):

Electron Microscopy ◽

Human Skin ◽

Osmium Tetroxide ◽

Human Epidermis ◽

Ultrastructural Changes ◽

Chemical Agents ◽

Skin Ultrastructure ◽

Volar Surface

Our laboratory is engaged in the study of the effect of different chemical agents on human skin, using electron microscopy. Previous investigations revealed that topical use of a strong alkali (NaOH 1N) or acid (HCl 1N), induces ultrastructural changes in the upper layers of human epidermis. In the current experiments, acetone and kerosene, which are primarily lipid solvents, were topically used on the volar surface of the forearm of Caucasian and Negro volunteers. Skin specimens were bioptically removed after 90 min. exposure and 72. hours later, fixed in 3% buffered glutaraldehyde, postfixed in 1% phosphate osmium tetroxide, then flat embedded in Epon.

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Changes in corneocyte element concentrations occur in skin inner stratum corneum

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100134326 ◽

1990 ◽

Vol 48 (2) ◽

pp. 146-147

Author(s):

R. R. Warner

Keyword(s):

Stratum Corneum ◽

Human Skin ◽

Element Concentration ◽

Skin Barrier ◽

Barrier Properties ◽

Brick Wall ◽

Inorganic Elements ◽

Dry Skin ◽

Skin Biopsies ◽

Intercellular Lipid

Keratinocytes undergo maturation during their transit through the viable layers of skin, and then abruptly transform into flattened, anuclear corneocytes that constitute the cellular component of the skin barrier, the stratum corneum (SC). The SC is generally considered to be homogeneous in its structure and barrier properties, and is often shown schematically as a featureless brick wall, the “bricks” being the corneocytes, the “mortar” being intercellular lipid. Previously we showed the outer SC was not homogeneous in its composition, but contained steep gradients of the physiological inorganic elements Na, K and Cl, likely originating from sweat salts. Here we show the innermost corneocytes in human skin are also heterogeneous in composition, undergoing systematic changes in intracellular element concentration during transit into the interior of the SC.Human skin biopsies were taken from the lower leg of individuals with both “good” and “dry” skin and plunge-frozen in a stirred, cooled isopentane/propane mixture.

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Desmosomal distribution in the epidermis of a non-contracting human skin equivalent

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100124884 ◽

1992 ◽

Vol 50 (1) ◽

pp. 896-897

Author(s):

L.X. Oakford ◽

S.D. Dimitrijevich ◽

R. Gracy

Keyword(s):

Human Skin ◽

Basal Layer ◽

Skin Equivalent ◽

Tissue Component ◽

Intact Skin ◽

Similar Sequence ◽

Sequence Of Events ◽

Suprabasal Keratinocytes ◽

Human Skin Equivalent

In intact skin the epidermal layer is a dynamic tissue component which is maintained by a basal layer of mitotically active cells. The protective upper epidermis, the stratum corneum, is generated by differentiation of the suprabasal keratinocytes which eventually desquamate as anuclear comeocytes. A similar sequence of events is observed in vitro in the non-contracting human skin equivalent (HSE) which was developed in this lab (1). As a part of the definition process for this model of living skin we are examining its ultrastructural features. Since desmosomes are important in maintaining cell-cell interactions in stratified epithelia their distribution in HSE was examined.

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Pyrotechnic Residues in Gunshot Residue Analysis

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100117649 ◽

1985 ◽

Vol 43 ◽

pp. 128-129

Author(s):

H. M. Sagara ◽

S. A. Schliebe ◽

M. C. Kong

Keyword(s):

Law Enforcement ◽

Residue Analysis ◽

Gunshot Residue ◽

Particle Analysis ◽

Dry Skin ◽

X Ray ◽

Skin Cells ◽

Smokeless Powder ◽

Carbon Coated ◽

Detailed List

Particle analysis by scanning electron microscopy with energy-dispersive x- ray analysis is one of the current methods used in crime laboratories to aid law enforcement in identifying individuals who have recently fired or handled a firearm. During the discharge of a firearm, the high pressure caused by the detonation of the cartridge materials forces a portion of the generated gases through leaks in the firing mechanism of the weapon. These gases contain residues of smokeless powder, primer mixture, and contributions from the projectile itself. The condensation of these hot gases form discrete, micrometer-sized particles, which can be collected, along with dry skin cells, salts, and other hand debris, from the hands of a shooter by a simple adhesive lift technique. The examination of the carbon-coated adhesive lifts consist of time consuming systematic searches for high contrast particles of spherical morphology with the characteristic elemental composition of antimony, barium and lead. A detailed list of the elemental compositions which match the criteria for gunshot residue are discussed in the Aerospace report.

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