Expression of the Human Immunoglobulin Heavy Chain VH6 Gene Element by Fetal B Lymphocytes

Fetal B lymphocytes in mice and humans use a limited number of the available V_H gene segments. Mouse fetal B cells primarily utilize 3' V_H elements, suggesting that the localization of these elements determines their rearrangement frequency. The previously reported non-random usage of human V_H genes has been more difficult to explain. In this study the authors analysed the expression of the most proximal 3' human V_H element (V_H6) using a monoclonal antibody (JE-6). V_H6 expression was assessed in various B cell differentiation stages from fetal liver, bone marrow and spleen at 12–20 weeks of gestation. The authors demonstrate that the level of V_H6 expression does not exceed a stochastic usage frequency. This suggests that the localization of V_H6 does not significantly promote its expression during human fetal life, and that other factors must affect the usage of V_H genes during human fetal development.     

Sustained eosinophil cationic protein release into tears after a single high-dose conjunctival allergen challenge

Background The appearance of eosinophils is a hallmark sign of the allergic late-phase response (LPR). Eosinophil cationic protein (ECP), a readily measurable product released from activated eosinophils, has so far not been evaluated in the ocular LPR. Objective Two sets of trials were performed in order to investigate changes of local and systemic eosinophil activity and their possible link with symptoms and hyper-reactivity in the allergic LPR in the eye. Methods In the first experiment, ECP was analysed in tears and serum and the clinical reaction was evaluated during a 72-h time–course after a single, high-dose allergen challenge out of season in one eye of 15 pollen-sensitized volunteers. In a second experiment, the hypothesis of an increased clinical response to an allergen challenge in an eye that had been provoked with allergen 48h previously was tested in nine sensitized individuals. Results In the first experiment, symptoms at 10 min and 2, 4, 6, 8 and 24 h significantly exceeded base line scores of the challenged eyes. Tear ECP was significantly elevated in challenged eyes compared to contralateral eyes at 6, 8 and 24 h. In addition, symptoms and ECP release correlated significantly at the 24-h evaluation. Serum ECP remained unchanged throughout the study period. In the second experiment, conjunctival hyperreactivity 48h after an allergen challenge was not confirmed. Conclusion ECP secretion occurs in the experimental ocular LPR and is in part associated with the magnitude of the clinical reaction, which suggests a truly pathogenic role of the activated eosinophil in pollen-induced allergic conjunctivitis.     

Allergen content in dust from homes and schools in northern Norway in relation to sensitization and allergy symptoms in schoolchildren

Background Previous studies have shown a high prevalence of atopic diseases among school children in the community of Sør-Varanger. Moreover, animal dander followed by pollen und house dust mite, were the most common allergens in skin prick tests. Objective To assess the allergen content in homes (living-rooms and mattresses) and classrooms of children living in an arctic area at 70° north. The presence of allergens in homes and schools and their relationship to atopy was of particular interest. Methods Dust samples from 38 homes and seven schools in northern Norway were collected by vacuum cleaning. The presence of allergens of dog, birch, timothy, Cladosporium herbanun, codfish and hen egg-white was investigated by radio-allergosorbent test (RAST) inhibition and the presence of major allergens of cat Felis domesticus (Fel d I) and house dust mites (HDM) Dermatophagoides pteronyssinus (Derp I) and Dermatophagoides farinae (Derf I) by enzyme-linked immunosorbent assay (ELISA). Results Mattresses contained significantly more dust per unit area than living-rooms and classrooms. No statistically significant differences in allergen content for dog. birch, timothy, Cladosporium, codfish and hen egg-white were seen between HDM-sensitized and non-atopic children. Most dust samples contained dog allergens with the highest allergenic activity found in living-rooms of those keeping dogs. An increased level of Feld I was detected in only one of 38 samples from living-rooms (this family kept a cat) and in 25 of 38 samples from mattresses with ranges from 24 to 84ng/m². The highest concentrations were found in mattresses of children keeping cats. Increased levels ( 25 ng/m²) of Derp I were found only in homes and virtually only in mattresses of HDM-sensitized children. An increased level of Derf] was found in only one case, i.e. in the mattress of an HDM-sensitized child where additionally Der p I and HDMs were demonstrated microscopically. When relating Der p I to HDMsensitization an odds ratio of more than 16 (95% Cl: 1.6–394.3) was found. All extracts from living-rooms included codfish allergens. Low RAST inhibition values were detected for hen egg-white, Cladosporium, birch and timothy pollen in most samples. Furthermore, the study demonstrated that dust from schools was relatively free of allergens. Conclusion Previous findings indicating that the main allergen exposure problem in this geographical area is that of pet allergens were confirmed.     

Restriction fragment length polymorphism of human mitochondrial DNA in a sample population from Apulia (Southern Italy)

Restriction fragment length polymorphism (RFLP) of human mitochondrial DNA was analysed in a sample of 87 subjects from Apulia (South Italy) by the restriction enzymes Hpa I, Bam HI, Hae II, Msp I, Ava II, and Hinc II using total blood cell DNA probed by human mtDNA from placenta. Five BamHI morphs were observed, two of which are new ( Bam HI-4 and -5), as well as one new Ava II morph ( Ava II-28). The association Bam HI-4/ Ava II-28 enables us to demonstrate for the first time two polymorphic Bam HI sites present together in the same mtDNA molecule. In agreement with historical data the Apulian sample has been shown to be the most heterogeneous Italian population so far tested.     

Synthesis of TPH-13, a new tridecapeptide from Phyllomedusa rohdei

The synthesis of TPH-13 (Glp-Glu-Lys-Pro-Tyr-Trp-Pro-Pro-Pro-Ile-Tyr-Pro-Met-OH), a tridecapeptide isolated from the skin of the South American frog Phyllomedusa rohdei, is described and alternative approaches are discussed.     

Intratemporal vascular tumors: detection with CT and MR imaging

The diagnostic contributions of computed tomography (CT) and magnetic resonance (MR) imaging were compared in 12 patients with benign intratemporal vascular tumors (hemangioma or vascular malformation). The tumors included six in the internal acoustic canal and six in the geniculate ganglion region. Clinical and histologic correlations were made. Two of the six patients with tumors in the internal acoustic canal underwent CT, and both required gas cisternography to show the tumor. Five patients in that group underwent MR imaging, and all five studies showed the tumor. All six patients with geniculate ganglion tumors underwent CT. Results in one study were questionable, and five showed the tumor. Five patients in this group underwent MR imaging, but the MR findings were positive in only two cases. MR imaging should therefore be performed before CT in the evaluation of facial nerve dysfunction, as it demonstrated all tumors in the internal acoustic canal and some in the geniculate ganglion region. If MR findings are negative, CT should then be performed to rule out a possible geniculate ganglion lesion.     

CHARACTERIZATION OF RAT TESTICULAR ALCOHOL DEHYDROGENASE

A protein from rat testes that catalyzes the oxidation of ethanolin the presence of NAD⁺, but not NADP⁺, has been characterizedenzymatically and compared to that of hepatic alcohol dehydrogenaseobtained from the same animals. The testicular enzyme, likethe hepatic enzyme, has a K_m value for ethanol in the 0.5–1.0-mMrange and can utilize other alcohols such as n-propanol, n-butanol,and isobutanol, although the K_m values for these other alcoholsare considerably lower (0.03–0.08 mM) that that for ethanol.The testicular enzyme is more heat-labile than is the hepaticenzyme. Finally, the testicular enzyme catalyzes the oxidationof retinol and its retinol dehydrogenase activity is inhibitedby ethanol.     

Acquired Cutis Laxa in Childhood Sweet's Syndrome

Abstract:  In Sweet's syndrome, the essential features are the characteristic morphology of the lesions, their histologic appearance, the dramatic response to corticosteroids and the absence of scarring. We report an 8-month-old infant in whom Sweet's syndrome was diagnosed and who developed acquired cutis laxa in the skin lesions.