Mammalian response to subdermal implantation of textured microimplants

The development of small, textured implant particles suspended in a hydrogel has allowed for subdermal injection therapy to fill tissue defects. The microimplant particles were placed subdermally into the ears of white New Zealand rabbits in order to characterize the foreign body response and the permanence of the implant. Serial micrometer readings were performed on the implant sites to determine any change in thickness of the augmentation following baseline measurement. An initial increase in the thickness was noted approximately 20–30 days postimplantation, as expected. A stable thickness was noted for the remainder of the experiment. Serial histological sections were performed at irregular intervals from one week to one year. Histology demonstrated a mild foreign body response with collagen surrounding each individual microimplant particle. The response was stable after 30–40 days and has remained stable for over one year. It was determined that the histology demonstrated a Boros IA type, or nonimmunogenic, low-turnover foreign body reaction.     

How often can the clinical diagnosis of exanthema subitum be confirmed with the HHV-6 serology test

Three years ago a newly recognized human herpes virus (HHV-6) was identified to be the causative agent for exanthem subitum (roseola infantum). So far this diagnosis was suggested chiefly by excluding other infections and the presence of a typical course of the disease. To find out how often the clinical diagnosis can be confirmed serologically, we asked five pediatricians in private practice as well as residents of the out-patient and infant departments of our hospital to obtain paired heparinized blood samples of any child suspicious for exanthem subitum. 36 children with clinically suspected exanthem subitum and a mean age of 14.2 (5-71) months were included in this prospective study. Indirect immunofluorescence was used to detect IgG and IgM antibodies to HHV-6. In 22 children (61%) the clinical diagnosis was confirmed serologically. IgM antibody was found in only 16 of these 22 children. In 8 patients the results were ambiguous. Three had in the same time a doubtful seroconversion to other viruses of the herpes group (HSV twice; EBV once), in four children there was an insufficient rise in IgG antibodies without presence of an IgM response, and once we found a very high HHV-6 specific antibody titre (greater than 1:80) in both serum samples. In 6 children neither a seroconversion nor a rise in HHV-6 antibody titre were found. Retrospectively, only three of these children had a clinical course really typical for exanthem subitum. We conclude that in most cases the clinical diagnosis of exanthem subitum will be confirmed by serological examination.(ABSTRACT TRUNCATED AT 250 WORDS)     

Pretransplant Exposure to Donor HLA-DR Antigen in Random Transfusion Units and the Development of Donor Antigen-Specific Hyporeactivity

Our previous studies have shown that the in vitro assay of donor antigen-specific hyporeactivity is a useful marker for identifying solid organ transplant recipients (kidney, lung and heart) at low risk for immunologic complications (i.e., late acute rejection episodes and chronic rejection). Donor antigen-specific hyporeactivity is defined as a significantly decreased post- vs. pretransplant proliferative response to donor antigens while response to third-party controls remains unchanged. We analyzed whether exposure to the same HLA-DR antigen pretransplant via random blood transfusion and posttransplant via the transplanted organ influenced the development of hyporeactivity. Thirty previously nontransfused recipients, each receiving two 150 ml pretransplant random blood transfusions, were assessed for hyporeactivity at 1 year posttransplant. Of the 12 recipients with pretransplant exposure to kidney HLA-DR via transfusions, 6 (50%) developed hyporesponsiveness; in contrast, of the 18 recipients who were not preexposed, only 3 (15%) exhibited this form of immunomodulation. Of interest, 2 of the 3 hyporesponsive recipients who were not preexposed, received units containing HLA-DR antigens previously shown to share crossreactive epitopes with the kidney HLA-DR. In conclusion, these results suggest a increased incidence in the development of hyporeactivity in patients receiving pretransplant transfusions which share an HLA-DR antigen with the transplanted kidney.     

Distribution of repetitive and non-repetitive circumsporozoite protein epitopes on Plasmodium falciparum sporozoites and immunochemical characterization of human malaria antisera.

The presence and distribution of circumsporozoite protein (CSP) epitopes located in the repetitive and non-repetitive regions were studied in three Plasmodium falciparum strains, NF54, IFA5 and IFA6. It was found by immunofluorescence, Western blotting and immunoelectron microscopy that mAbs to epitopes of the repetitive domaine bound similarly to the CSP of all three strains. MAbs to epitopes of the flanking regions yielded either some strain differences (mAbs to the C-terminal end), or reacted only in immunofluorescence tests on whole sporozoites (mAbs to the N-terminal end). Human sera from an area endemic for malaria, two of them positive in ELISA on (NANP)40 and two negative, were tested for their reactivity with epitopes of the flanking regions of the CSP. The presence of antibodies to such epitopes could be demonstrated by Western blots and immunocytochemistry independent of the reactivity of the sera to recognize (NANP)40. All tested bound to salivary gland tissues but not to their secretory product in immunocytochemical experiments.     

Immune response to immunostimulatory complexes (ISCOMs) prepared from human immunodeficiency virus type 1 (HIV-1) or the HIV-1 external envelope glycoprotein (gp120)

In mice, immunostimulatory complexes (ISCOMs) prepared from HIV-1 B external envelope glycoprotein (gp120) induced 10-fold higher antibody titres than gp120 emulsified in depot adjuvant, as measured by enzyme-linked immunosorbent assay (ELISA). Rhesus monkeys immunized with gp120 ISCOMs produced precipitating and virus neutralizing antibody titres equivalent to those seen in HIV-infected chimpanzees and humans. After multiple immunizations with HIV-1 B gp120 ISCOMs, a rhesus monkey developed a neutralizing response to the HIV-1 isolates RF and MN, but not to the CC isolate. Antisera from ISCOM-immunized rhesus monkeys recognized gp120 on the membranes of HIV-1 B-infected H9 cells, indicating the preservation of epitope structure in the ISCOMs matrix.     

The HK/MBD Questionnaire: Replication and Validation of Distinct Factors in a Nonclinical Sample

Although Tarter et al.'s (1977) HK/MBD questionnaire has been found useful in subtyping populations of clinical alcoholics, its potential utility in nonclinical populations has yet to be determined. The current study examined the family history, personality, and substance use/abuse correlates of Tarter et al.'s HK/MBD questionnaire and factor analytically derived subscales (Alterman and McLellan, 1986) in a nonclinical sample of 580 young, adult males. In addition, a factor analysis of the HK/MBD questionnaire was undertaken to assess the extent to which the factor structure determined on a clinical alcoholic sample replicates in a nonclinical sample. Results indicated that each of the HK/MBD subscales showed relatively unique patterns of correlations with the various personality measures employed suggesting that they are measuring separate constructs. Perhaps of greatest importance, the HK/MBD items that appear to be of greatest relevance for understanding substance use/abuse are those related to antisocial behavior. Finally, the factor structure of the HK/MBD questionnaire in the nonclinical sample was found to be quite similar to the structure obtained in a clinical sample. These results demonstrate the multidimensional structure of the HK/MBD questionnaire and the utility of using the more homogeneous subscales in research with both clinical and nonclinical samples.