In vivo evaluation of occlusal wear of two experimental composites versus amalgam

Two experimental inhomogeneous microfilled composites with spherical prepolymerized particles and an interpenetrating network (IPN), which provides a stable bond between prepolymerized spheres and the matrix (B-21 and B-51), and amalgam were used for Class II MOD fillings in mandibular molars. After 3 and 6 months of clinical use, wear of the material was measured with a replica technique and a modified surface roughness test. The failure mode was analysed with SEM photographs also using a replica technique. After 6 months the wear of the composites in the occlusal contact area was more than twice as high as the substance loss of amalgam. It was concluded that the composites were not suitable for fillings bearing occlusal load. However, the failure mode seen in the SEM for B-21 indicated that the IPM leads to a stable incorporation of the spherical prepolymerized particles into the matrix. Due to its good surface characteristics B-21 should be further investigated for its use as an anterior composite. B-51 was especially designed as a posterior composite. Beside the construction elements of B-21 it contained also barium glass spheres to obtain radiopacity. This hybrid construction failed due its wear mode.     

Predictive animal testing for photocontact allergenicity

The purpose of this investigation was to establish a standardized animal model to predict the photoallergenic potential of new chemical compounds. In a first series of experiments the main factors influencing the induction of photoallergenicity were evaluated (induction concentration, pH of the test solution, pretreatment of the irradiation site with sodium lauryl sulphate, additional use of adjuvant injections and routes of administration). Osram Ultravitalux lamps were utilized for these studies.
In a second series of experiments a Xenon 6000 W radiation source was used. Positive results were obtained with well known photosensitizers, as, for instance, the halogenated salicylanilides, as well as with so-called weak photoallergens (e.g. bithionol, sulphanilamide) by stimulating the animals' immune system with Freund's complete adjuvant.
The photoallergenic compounds were at the same time tested for their contact allergenic potential in the optimization test.
A standard procedure for the predictive photoallergenicity assay in guinea-pigs is proposed.     

Serum levels of soluble intercellular adhesion molecule 1 are increased in chronic B-lymphocytic leukemia and correlate with clinical stage and prognostic markers [see comments]

The serum levels of soluble intercellular adhesion molecule 1 (ICAM-1) were significantly elevated (P < .001) in patients with chronic B- lymphocytic leukemia (B-CLL, n = 113) compared with healthy controls (n = 31). sICAM-1 levels in B-CLL were positively correlated to the tumor mass as reflected by the modified Rai and the Binet staging systems, lymphocyte counts, and isolated spleno/hepatomegaly. During disease progression or regression on cytoreductive therapy, the circulating sICAM-1 levels changed accordingly. sICAM-1 was also correlated to a kinetic parameter such as the lymphocyte doubling time. Furthermore, the serum sICAM-1 levels were inversely correlated to hemoglobin levels in patients with early clinical stage, and this may turn out to be of prognostic value. sICAM-1 was compared with other serum markers said to reflect disease activity in B-CLL, ie, soluble CD23, thymidine kinase, lactate dehydrogenase (LDH), and beta 2-microglobulin. sICAM-1 was equally well or better correlated to clinical stage and lymphocyte doubling time. In univariate regression analysis, all serum markers but LDH correlated with survival, and in multivariate analysis, sICAM-1 was the only marker approaching significance for additional prognostic information when included after clinical stage and lymphocyte doubling time. Based on the present observations, it appears that prospective studies repeatedly monitoring serum sICAM-1 in B-CLL are justified.     

Antibody-dependent enhancement of HIV-1 infection in human term syncytiotrophoblast cells cultured in vitro

We examined if Fc receptor-mediated antibody-dependent enhancement (FcR-ADE) or complement-mediated antibody-dependent enhancement (C′-ADE) of virus infection can contribute to increasing replication of HIV-1 in human syncytiotrophoblast (ST) cells. Here we report that both FcR-ADE and C′-ADE may result in enhanced virus release from HIV-1-infected ST cells. We show that FcR-ADF of HIV-1 infection in ST cells is mediated by FcRIII and other FcR(s) belonging to undetermined Fc classes and does not require CD4 receptors, whereas C'-ADE uses both CD4 and CR2-like receptors. FcR-ADE: seems to be more efficient in enhancing HIV-I replication than C′-ADE. While FcR-ADE leads to increased internalization of HIV-1. C′-ADE does not result in enhanced endocytosis of the virus. In addition, antibodies mediating FcR-ADE arc reactive with the gp120 viral envelope antigen, whereas antibodies involved in C′-ADE react with the viral transmembrane glycoprotein gp41. Data suggest that both FcR-ADH and C′-ADE may contribute lo the spread of HIV-1 from mother to the fetus.