Gian Carlo Manara

Clarithromycin versus doxycycline in the treatment of rosacea

Forty patients with rosacea were entered into a study comparing clarithromycin with doxycycline in the systemic treatment of mild and severe rosacea. The patients, 25 women and 15 men, aged from 26 to 62 years, were subdivided into two homogeneous groups with regard to age, sex, and disease seventy. The first group of 23 patients, 14 women and 9 men, was treated with 250 mg of clarithromycin for 4 weeks twice daily, and then with 250 mg once daily for the following 4 weeks. The second group of 17 patients, 11 women and 6 men was treated with 100 mg of doxycycline for 4 weeks twice daily, and then with 100 mg once a day for the following 4 weeks. Both objective and subjective evaluations of the dermatosis were performed prior to therapy and after 4, 6, and 8 weeks of treatment.

Ultrastructural characterization of human large granular lymphocyte subsets defined by the expression of HNK-1 (Leu-7), Leu-11, or both HNK-1 and Leu-11 antigens.

A peroxidase-colloidal gold double labeling system in immunoelectron microscopy was used to investigate the ultrastructural features of human large granular lymphocytes (LGL) subpopulations. Three subsets of LGL, Leu-7+-Leu-11-, Leu-7+-Leu-11+, Leu-7- -Leu-11+, were characterized using combinations of the monoclonal antibodies anti-Leu-7 and anti-Leu-11. They showed different ultrastructural patterns. In fact, Leu-7+-Leu-11- cells showed a high nuclear/cytoplasmic ratio (N/C), a round nucleus, a cytoplasm with few organelles, and a rather even surface. Moreover, most of them lacked electron-dense granules. On the other hand, Leu-11+ cells displayed a low N/C, an irregular-shaped nucleus, and a cytoplasm containing a well-developed Golgi apparatus, many mitochondria, vacuoles, vesicles, and numerous electron-dense granules. Moreover, they exhibited an irregular cell surface. Thus, Leu-7+-Leu-11- cells seemed to represent an immature form of LGL, while cells expressing the Leu-11 antigen showed a fine structure specific for functional NK cells. Our findings suggest that the expression of HNK-1 (Leu-7) and Leu-11 antigens respectively represents subsequent stages in NK cell differentiation.

Macrophage — T-lymphocyte interaction in lichen planus

SummaryPapular lichen planus lesions from 12 patients were studied by a double-step immunocyto-chemical method to detect T-lymphocytes. Semithin sections were studied by light microscopy and ultrathin sections examined by electron microscopy. In the dermal infiltrate, many T-lymphocytes appeared closely juxtaposed to macrophages or Langerhans cells, frequently arranged in a rosette-like pattern. In the epidermis, T-lymphocytes were juxtaposed to macrophages or Langerhans cells and to degenerated keratinocytes. The close relationship between T-lymphocytes, macrophages or Langerhans cells and degenerated keratinocytes supports the hypothesis that lichen planus is immunological in nature: T-lymphocytes, after interacting with macrophages or Langerhans cells, become cytotoxic for keratinocytes.

Human normal‐resting epidermal Langerhans cells do express the type 3 complement receptor

The expression of CR3 by murine‐resting epidermal Langerhans cells (LC) is well established, but CR3 expression by human normal‐resting epidermal LC has not yet been demonstrated. In this study, highly sensitive immunostaining techniques, such as immunogold labelling in transmission‐ and scanning‐electron microscopy, were used on freshly isolated, LC‐enriched, normal human epidermal cells. Human normal resting epidermal LC were found to be CR3+, since a low but significant number of gold granules labelled the plasma membrane of all the LC observed under transmission‐electron microscopy, and all the epidermal cells showing LC morphology as observed by scanning‐electron microscopy.

Hairy cell leukemia cells express CD1A antigen

Five patients with hairy cell leukemia (HCL) were studied. Peripheral blood leukocytes, rosette‐forming cells (T) and non‐T‐cells were stained in immunofluorescence by a panel of monoclonal antibodies to investigate the phenotype of HCL cells (HCLC). In all patients HCLC showed B‐lymphocyte phenotype, although they were not stained by antibodies reactive for monocytes, natural killer cells, or T‐cells. However, in all instances the large majority of HCLC were unexpectedly stained with an antibody (anti‐CD1a) usually detectable only in early thymocytes and on Langerhans cells. This finding was further confirmed by immunoelectron microscopy. This type of ambiguity in the lineage of HCL could imply that HCLC might arise from cells differentiated towards the B‐cell lineage, still sustaining an early antigen of a different (T) lineage. These results, moreover, extend the range of the known distribution of the CD1a antigen, which could be useful in diagnosing HCL.

The S-100β protein in normal human peripheral blood is uniquely present within a discrete suppressor-T-cell compartment

The S-100-positive T lymphocytes, and, particularly, the S-100 beta subunit, are restricted, as demonstrated by quantitative subset analysis and double-labeling (gold-peroxidase) immunoelectron microscopy of T-cell subpopulations, to an unique T8-positive cell subset which interestingly was 9.3-negative and CD11b-positive. Since both the T8-positive, 9.3-negative and the T8-positive, CD11b-positive subpopulations have been demonstrated to show suppressive activities, the S-100-positive T cells seem to be closely restricted to a small T-suppressor-cell compartment. Although functional studies on viable isolated S-100 beta-positive cells are impossible to achieve, due to the lack of this protein on the cell membrane, its presence in a discrete T-suppressor compartment might suggest a possible role for the S-100 beta-positive T cells in the regulation of the immune system.

Macrophage–T lymphocyte relationships in man's contact allergic reactions

Seventeen biopsies from contact allergic reaction sites in sensitized patients were studied by electron microscopy and immunocytochemistry. Very intimate appositions of macrophages to T lymphocytes were frequently observed in the dermis at 6, 8 and 12 hours after application of the allergen. Such juxtapositions were seen less frequently after 24, 48 and 72 hours. These appositions seem to indicate that macrophages play an antigen‐presenting role in human contact allergic reactions, as Langerhans cells seem to do.

S-100-positive T cells are largely restricted to a CD8-positive, 9.3-negative subset

SummaryThe present report concerns the demonstration of the exclusive detection among peripheral blood T-lymphocytes of the S-100 protein within the CD8-positive subpopulation wich lacks the antigen recognized by the 9.3 monoclonal antibody. Highly purified human peripheral blood T-cell subsets, obtained by means of panning techniques, were first stained, by an immunofluorescence method, with purified anti-S-100 protein antibodies. The vast majority of S-100 protein- (and, specifically, itsβ subunit) positive cells were detected in the CD8-positive, 9.3-negative subset. This subset had previously been shown to comprise all the alloantigen-specific and histamine-inducible suppressor T-cells. Other T-subsets, even those showing either CD8-positivity (but 9.3-positivity) or 9.3-negativity (but CD8-negativity), were, as a rule, S-100 negative. Immunoelectronmicroscopy confirmed that the S-100-positive cells, showing peroxidase activity within the cytoplasm, were found exclusively within the CD8-positive, 9.3-negative subset. This finding of S-100 protein in cells of a specific T8 suppressor subset extends the range of the known distribution of this protein and may have important implications concerning its role in the modulation of immune responses.

Immunoperoxidase-immunogold double labelling in immunoelectronmicroscopy of large granular lymphocytes

A method for better characterization of mononuclear cell subpopulations using detection of 2 surface antigens simultaneously in electron microscopy was developed with immunoperoxidase-immunogold double labelling. Monoclonal antibodies of IgG and IgM classes were used in the first step, and colloidal gold-labelled anti-mouse IgG antibody and peroxidase-labelled anti-mouse IgM antibody (mu chain-specific) in the second step. Immunoelectronmicroscopy with such double labelling improves ultrastructural analysis of mononuclear cell subpopulations.

Contact urticaria syndrome due to phyenylmercuric acetate

Case no. 2 A 32-year-old male had a !-month history of eczema on the hands, neck and face (Fig. 2). He had started work as a parquet layer a short time before its onset. Lesions improved greatly when the patient stopped work. Patch tests were performed with the GIRDCA standard series, their glue (Pelpren PL/6) and its constituents. Both patients reacted to Pelpren PL/ 6 as is ( + + + ), epoxy resin ( + + + ), and benzyl alcohol ( + + + ), plus isophoronediamine ( + + +) in patient no. 1. After leaving their jobs, both patients made a definite and long-lasting recovery.