Relativistic statistical thermodynamics of dense photon gas.

We discuss some aspects of interactions of high-frequency electromagnetic waves with plasmas, assuming that the intensity of radiation is sufficiently large, so that the photon-photon interaction is more likely than the photon-plasma particle interaction. In the stationary limit, solving the kinetic equation of the photon gas, we derive a distribution function. With this distribution function at hand, we investigate the adiabatic photon self-capture and obtain the number density of the trapped photons. We employ the distribution function to calculate the thermodynamic quantities for the photon gas. Having expressions of the entropy and the pressure of the photon gas, we define the heat capacities and exhibit the existence of the ratio of the specific heats Gamma , which equals 7/6 for nonrelativistic temperatures. In addition, we disclose the magnitude of the mean square fluctuation of the number of photons. Finally, we discuss the uniform expansion of the photon gas.

Melanoma. Associated antigens in benign melanocytic disorders.

Three instances of depigmentation occurring in children with congenital large nevocytic nevi are reported. Serologic studies for tumour-associated antigens to melanoma were performed by indirect immunofluorescence and complement fixation on these patients and others with benign melanocytic disorders. Positive reactivity in several children was observed. The small numbers studied and lack of uniformity of other testing methods leave open the question of relevance of such reactivity to malignant conversion or protection in congenital nevi.

Apparently normal skin in lepromatous leprosy: histopathological findings.

Biopsy specimens of apparently uninvolved skin from 34 patients with lepromatous leprosy were studied histologically. Bacilli were found in 30 of 31 specimens from clinically polar or near-polar lepromatous patients but not in the three from nonpolar patients. A predominantly perivascular distribution of infiltrate and bacilli is consistent with a hematogenous spread of infection. Subclinical, diffuse lepromatous leprosy is found in patients with nodular lesions and may precede the development of nodules. Study of apparently uninvolved skin may be helpful in classifying patients, in interpreting immunologic responses, and in elucidating the natural history of the illness.

Production of ring-shaped particles by normal and metaplastic tissue. I. Human skin.

Maintenance media incubated with biopsy specimens of human skin tissues contained minute (10-12 nm wide), ring-shaped particles (RSP) similar to those described previously in culture media of mammalian cell lines. In addition to the qualitative demonstration of the particles by electron microscopy, a quantitative method was applied to estimate in media the amount of DNA that could be attributed primarily to RSP content. The amounts of DNA, obtained with 146 test specimens, varied with the pathologic condition of the tissue in the following ascending order: normal skin, verruca vulgaris, seborrheic verruca, actinic keratosis, basal cell carcinoma, and squamous cell carcinoma.

Immunoglobulin deposits in lepromatous leprosy skin. Presence of deposits in apparently uninvolved skin and occurrence of serum antiepithelial antibodies.

Immunoglobulin deposits were detected in ten of 13 biopsy specimens from apparently uninvolved skin of patients with lepromatous leprosy. There were deposits of IgM at the dermoepidermal junction in the skin of five patients, and deposits of IgM along the dermal collagen and elastic fibers in the skin of the other five. The deposits were eluted with acid buffers and high molarity salt solution. Circulating IgG antibodies to intercellular substance of epithelial cells, similar to those present in pemphigus vulgaris, were found in 25% of patients with lepromatous leprosy who were studied. These antibodies appeared to be different from the skin-bound immunoglobulin deposits.