Stanley A. Rosenthal

Antigen-bearing Langerhans cells in skin, dermal lymphatics and in lymph nodes

Abstract Ferritin-challenged skin sites and draining lymph nodes were studied in normal guinea pigs and in guinea pigs which had been passively sensitized to ferritin or peroxidase by lymphoid cell transfer to ascertain whether Langerhans cells can bind antigen in skin and carry it to lymph nodes. After intradermal challenge with amounts of ferritin as small at 5 μg, ferritin-containing Langerhans cells were seen by electron microscopy in the marginal sinus and cortex of draining lymph nodes in ferritinscnsitized animals and, to an apparently lesser degree, in control animals. Lymph nodes from unchallenged normal guinea pigs contained rare Langerhans cells, none of which had ferritin. The findings indicate that Langerhans cells may pick up antigen in skin and from there circulate to draining lymph nodes, thus carrying out a function analogous to macrophages. In this way they may exhibit antigen to lymphocytes both in skin and in lymph nodes.

Dermal and intravascular Langerhans cells at sites of passively induced allergic contact sensitivity

Abstract In order to further define the role of Langerhans cells in contact allergic reactions, passive transfer studies were done in guinea pigs using 2,4-dinitro-1-chlorobenzene (DNCB)-sensitive donor cells. Langerhans cells were found in the lumen of dermal vessels resembling lymphatics at 2, 3, 15, and 48 hr after DNCB challenge. In contrast to the previously reported findings in actively sensitized guinea pigs, the changes involving Langerhans cells in passively sensitized guinea pigs were mainly noted in the dermis. These consisted of increased numbers of Langerhans cells and of mononuclear cells apposed to Langerhans cells 3 or more hours after challenge with DNCB. The increased Langerhans cell population in the dermis and the presence of Langerhans cells in dermal vessels in specifically challenged sites in adoptive immune reactions furnishes further support for a significant role of Langerhans cells in the interaction between antigen and sensitized cells.

Zygomycosis and HIV infection

The severe immunosuppression associated with HIV infection increases susceptibility to opportunistic fungi. We describe a primary gangrenous cutaneous infection caused by Rhizopus arrhizus in an HIV-infected intravenous narcotic user. In addition, we review nine reported cases of zygomycosis in HIV-infected patients and discuss the frequency and outcome of zygomycosis in HIV infection. Eight of 10 patients were intravenous drug users. Cutaneous infection occurred in four patients. Another case was associated with drug-induced neutropenia. With treatment, 60% of the patients recovered. HIV-induced immunosuppression rarely predisposes to zygomycosis except in intravenous drug users or persons with other risk factors for this fungal infection.

Primary cutaneous infection by Aspergillus ustus in a 62-year-old liver transplant recipient

We report the first case of primary cutaneous aspergillosis caused by Aspergillus ustus, a species that seldom infects human beings. The patient, a 62-year-old liver transplant recipient with end-stage hepatitis C-induced cirrhosis, was receiving the experimental immunosuppressive drug FK-506. Trauma to the skin of the right arm from tape and from an arm board holding intravenous and intraarterial catheters in place and to the left leg from an occlusive knee brace may have contributed to this unusual mycosis. The patients cutaneous aspergillosis responded to a combination of intravenous amphotericin B and topical terbinafine cream. Although the patient died shortly thereafter from hepatic failure, there was no evidence of systemic aspergillosis.

Langerhans cells: Target cells in immune complex reactions

Abstract Skin of normal, cobra venom extract-treated, and C 4 -deficient guinea pigs was injected with ferritin-antiferritin or with peroxidase-antiperoxidase immune complexes. Skin and draining lymph nodes were studied to compare the phagocytosis of these immune complexes by Langerhans cells (LC) and by macrophages. When complement was present, immune complexes were damaging to LC, and uptake of the immune complexes, although present, was limited. When components of complement were absent or diminished, increased numbers of LC in lymph nodes were seen, but damage to LC was absent or decreased. However no detectable change in the amount of phagocytosis by LC was noted. Since some LC can carry antigen from skin to lymph nodes and may be involved in the presentation of antigen to lymphoid cells in some cell-mediated immune responses, impairment or abolition of LC function by immune complexes could represent a mechanism through which the local presence of antibodies might interfere with the induction and elicitation of cellular immunity by antigen. Moreover, damage to LC and subsequent release of intracellular (lysosomal?) substances may constitute a general mechanism of response in the skin to injury and may be an integral part of inflammatory and allergic skin reactions.

Newer Studies on the Epidemiology of Fungous Infections of the Feet

were really produced in this manner, it would justify the continuation of such attempted prophylactic measures as: the exclusion of persons with fungous infection of the feet from the use of public bathing facilities; the use of disinfectants on the floors of shower and locker rooms; the installation of antiseptic foot baths; and the use of individual disposable slippers. These and other rituals have been recommended over and

A comparison between Dactylaria gallopava and Scoleocobasidium humicola: first report of an infection in a tortoise caused by S. humicola

Scolecobasidium humicola, a soil fungus and etiologic agent of phaeohyphomycosis in fish, is herein reported to cause cutaneous lesions in a tortoise, Terrapine carolina var. carolina. S. humicola was isolated from lesions on the foot and dematiaceous hyphae were observed in KOH preparations of the biopsy and in stained preparations. This isolate and others were compared morphologically and physiologically with isolates of Dactylaria gallopava which it resembles. As a result of this investigation, we concluded that D. gallopava may be differentiated from S. humicola macroscopically, by the production in D. gallopava of an extensive diffusible purplish-red to reddish-brown pigment when cultured on Sabouraud dextrose agar; microscopically, by the presence and usually predominance of conidia, whose apical cell is markedly wider than the basal cell, and usually constricted at the septum; and physiologically, by the ability to grow on media containing cycloheximide and by the ability to grow well at 36-45 degrees C. In contrast, S. humicola does not usually produce a diffusible pigment on Sabourauds dextrose agar or if present, is not extensive; it lacks the wider upper cell; is less constricted or non-constricted at the central septum; grows on media containing cycloheximide, although some inhibition may occur and lastly, does not grow at 36 degrees C or higher. Both species were urease positive, hydrolysed tyrosine but not casein, xanthine, or gelatin.

Studies in the differentiation between Microsporum ferrugineum ota and Trichophyton soudanense Joyeux

A study, conducted with 20 isolates of Microsporum ferrugineum and 12 isolates of Trichophyton soudanense, revealed that some of the discrepancies in the literature regarding their characteristics and differentiation were due to methodology, strain variation and the use of an insufficient number of isolates. We found all isolates of T. soudanense to be urease negative and gelatinase positive (usually by the first week); to produce brown to black colonies on Lowenstein-Jensen medium; to rapidly decompose casein and more slowly tyrosine; to grow well or better at 37°C as compared to room temperature; to produce reflexive branching on cornmeal Tween agar and abundant microconidia on casero medium and to exhibit no sexual reaction with either mating type of Arthroderma simii. All but one isolate demonstrated restricted growth on lactose agar and only three isolates perforated hair.In contrast, we found 18 of 20 isolates of M. ferrugineum to be urease positive in urea broth (most isolates were negative on urea agar); all produced light-colored colonies on Lowenstein-Jensen medium; spreading colonies on lactose agar and failed to perforate hair in vitro or to produce reflexive branching. Most isolates manifested poorer to no growth at 37°C compared to room temperature and all but one failed to decompose casein and tyrosine. A few strains produced macroconidia and/ or microconidia on casero medium and some reacted sexually with A. simii (a) or (−) mating type. Gelatin hydrolysis was variable.We suggest the following key tests to differentiate M. ferrugineum from T. soudanense: urease activity in urea broth; colony color on Lowenstein-Jensen medium; growth on lactose agar; growth at 37° C compared to room temperature; presence of reflexive branching on cornmeal Tween agar.

Failure to Sensitize to Autologous Skin.

Summary 1) Eighty-nine guinea pigs were injected intracutaneously, intramuscularly or intraperitoneally with autologous skin in emulsion with adjuvants. Thirty-eight guinea pigs were injected intracutaneously or intramuscularly with control emulsion, not containing skin. Subsequently an autograft was done on each animal. No significant differences were noted in acceptance of autografts between animals injected with skin emulsion and control emulsion. 2) Irritancy tests using scraping and burning of the skin did not produce different results in the test animals and the control animals. 3) Under the conditions of these tests no autosensitization to skin could be demonstrated in guinea pigs.

Studies on contact sensitivity to DNCB in guinea pigs by the macrophage migration test.

Guinea pigs contact-sensitized to 2,4-dinitrochlorobenzene (DNCB) by foot-pad injections or by topical applications of the hapten were studied by the direct macrophage migration test using DNP-guinea pig albumin (DNP-Alb) and DNP-guinea pig skin extract (DNP-SE) as antigens. Specific inhibition of macrophage migration in the presence of either antigen was found in a significant number of animals exhibiting contact sensitivity to DNCB. However, a wide variation in migration indices was observed in both groups of sensitized animals, with some animals showing a significant enhancement of macrophage migration.