The in vivo diagnosis of shrimp allergy must continue to be based on SPT with fresh material. Shrimp-allergic patients frequently react to a number of ill-defined high-molecular-weight allergens, thus leaving currently available materials for component-resolved diagnosis largely insufficient. Mites and crustaceans probably share several allergens other than tropomyosin.

Cell surface expression of carbohydrate receptors (i.e. mannose and galactose receptors) and phagocytosis of apoptotic cells by sinusoidal liver cells was studied. Binding sites and phagocytic activity were quantified at different time intervals (1, 3, 5, 7, 9, 11, 13, 15, 20, 30, 40 and 60 days) after the in vivo administration to rats of a potent liver mitogen, lead nitrate, that also induces apoptosis. The number and distribution of binding sites was receptor and cell-type dependent during the days following the metal injection. The use of competing saccharides in inhibition uptake experiments suggests that sinusoidal liver cells actively phagocytose apoptotic hepatocytes and circulating apoptotic cells by using both receptors. In particular, Kupffer cells at 5 and 15 days after the lead nitrate injection are very active in internalizing apoptotic cells (two- to threefold control). However, phagosomes containing apoptotic hepatocytes are often seen inside the cytoplasm of parenchymal and endothelial cells.

The present study reports the effects of retinoic acid (RA) on cultured fetal rat hepatocytes. We show that RA treatment induces both differentiation and apoptosis. Hepatocytes cultured for 48 hours in the presence of 5 mol/L RA form junctional complexes in the areas of contact between neighboring cells and develop bile canaliculi, typical features of mature and well-differentiated cells. At the same time, about 20% of cells are induced to die by apoptosis, and the percentage of apoptotic cells increases according to the concentration of RA used and the duration of treatment. The induction of apoptosis, studied at the morphological and biochemical levels, revealed that, in our system, the classical compaction of chromatin occurs only during the final stages of the process; instead of the common marker of apoptosis, i.e., the ''DNA ladder'' pattern of fragmentation, megabase-sized fragments were found. These observations provide further evidence of the existence of fundamental differences in the mechanisms of apoptosis among cell types. To investigate the molecular mechanism of the effects of RA, we evaluated the expression of two proteins, c-myc and p53, which are known to be involved in both cell differentiation and apoptosis. The data obtained show that the amount of p53 remained unchanged after RA treatment. On the contrary, a dose-dependent reduction in c-myc levels was found, suggesting that RA action may be mediated by modulation of this oncogene. Our findings regarding the apoptosis-inducing effect of RA, which was not found in adult hepatocytes, suggest a possible relationship between this phenomenon and the proliferative capacity and/or differentiation state of hepatocytes. (HEPATOLOGY 1998;28: 727-737.) Natural and synthetic retinoids, members of the vitamin A family, are compounds with numerous pleiotropic effects.

We investigated by ELISA the IgE response to whole extract of the house-dust mite Dermatophagoides pteronyssinus (Dp) and to the native major allergens, Der p 1 and Der p 2, in sera from 18 adult patients (group A) with Dp-allergic asthma before (t0) and 1, 2, 3, and 4 (t1-t4) years after subcutaneous specific immunotherapy (SIT). A qualitative reduction (P = 0.05) of the IgE responses to Dp and Der p 2 was observed from t1 to t4, but a highly statistical significant decrease appeared at t3 (P < 0.01). With regard to Der p 1 IgE values, the immunotherapy induced a significant decrease (P < 0.01) at t3, but not before. In group A, the IgE responses to Der p 1 and Der p 2 were not correlated at t0 (rs = 0.31; P = 0.21) but were correlated at t3 (rs = 0.78; P = 0.001). We also examined sera from 14 adult patients (group B, same SIT schedule as group A) who were without respiratory symptoms at the end of the third year (t3) of Dp SIT. At this time (t3), there were no significant differences in Der p 1 and Der p 2 IgE levels between group A and group B.

Skin cancer is one of the most commonly diffused cancer in the world and its incidence rates have constantly increased in recent years. At the current state of the art, there is a lack of objective, quick and non-invasive methods for diagnosing this condition; this, combined with hospital crowding, may lead to late diagnosis. Starting from these considerations, this paper addresses the implementation of a microwave reflectometry based-system that can be used as a non-invasive method for the in-vivo diagnosis and early detection of biological abnormalities, such as skin cancer. This system relies on the dielectric contrasts existing between normal and anomalous skin tissues at microwave frequencies. In particular, a truncated open-ended coaxial probe was designed, manufactured and tested to sense (in combination with a miniaturized Vector Network Analyzer) the variations of skin dielectric properties on a group of volunteer patients. The specific data processing demonstrated the suitability of the system for discriminating malignant and benign lesions from healthy skin, ensuring simultaneously effectiveness, low cost, compactness, comfortability and high sensitivity.