Heterologous radioimmunossay of monkey alpha-fetoprotein.

Immunoelectrophoresis showed that rabbit anti-human alpha-fetoprotein (AFP) cross-reacts with monkey AFP which was not detectable in the serum from an adult non-pregnant monkey. A heterologous radioimmunoassay of monkey AFP was developed using this antiserum which circumvented the need for purified monkey AFP. The radioimmunoassay is of sufficient sensitivity to measure AFP in maternal and fetal serum and amniotic fluid in the rhesus monkey.     

Evidence for projections from the rostral medullary raphe onto medullary catecholamine neurons in the rat

Following the iontophoretic deposition of Phaseolus vulgaris leucoagglutinin (PHA-L) into the rostral medullary raphe, which included portions of the caudal nucleus raphe magnus, rostral nucleus raphe pallidus, rostral nucleus raphe obscurus and rostral nucleus reticularis paragigantocellularis, two-color immunoperoxidase staining was employed to demonstrate contiguity between PHA-L-immunoreactive (PHA-LI) varicose fibers and boutons and medullary catecholamine (CA) cells. Raphe projections were contiguous with phenylethanolamine N-methyltransferase-immunoreactive (PNMTI) neurons in the C1, C2 and C3 cell groups and with tyrosine hydroxylase-immunoreactive (THI) neurons in the A1 and A2 cell groups. Contiguity between PHA-LI processes and medullary CA cells was observed most frequently in the C1 cell group. Preliminary findings of this study have been presented previously.     

Monoclonal antibodies against Pseudomonas aeruginosa outer membrane antigens: isolation and characterization.

Hybridomas secreting monoclonal antibodies specific for Pseudomonas aeruginosa outer membrane antigens were isolated. One of the antibodies was highly specific for the O antigen of the lipopolysaccharide of International Antigen Typing Scheme serotype 5 strains, reacting only weakly with a serotype 17 strain and failing to react with the outer membranes of strains representing 15 other serotypes. This monoclonal antibody was able to agglutinate heat-killed bacterial cells as well as lipopolysaccharide-coated sheep erythrocytes. Two other monoclonal antibodies were able to interact with the outer membranes of strains representing all 17 serotypes, although they were unable to agglutinate heat-killed bacterial cells. One of these was shown to be specific for the major outer membrane lipoprotein H2. The antigenic site against which this monoclonal antibody reacted was present in the outer membranes of two Pseudomonas fluorescens strains, two Pseudomonas putida strains, a Pseudomonas anguilliseptica strain, and an Azotobacter vinelandii strain, but not in the outer membranes of five other bacterial species.     

Colonial dissociation and susceptibility to phagocytosis of Pseudomonas aeruginosa grown in a chamber implant model in mice.

Pseudomonas aeruginosa strains were grown in 1-cm plastic chambers sealed at both ends with porous Millipore filters and implanted in the peritonea of mice. Mucoid and nonmucoid strains of P. aeruginosa isolated from a patient with cystic fibrosis largely retained their phenotypes when grown for up to 1 year in this in vivo system, although colonial dissociation occurred, as observed in chronic lung infections of patients with cystic fibrosis. In the absence of added opsonins, P. aeruginosa M2 cells taken directly from the in vivo system were significantly more susceptible to phagocytosis than were the same P. aeruginosa cells after being washed in buffer. Phagocytosis of in vivo-grown P. aeruginosa cells could be further enhanced by using a porin protein F-specific monoclonal antibody.     

Use of monoclonal antibodies to protein F of Pseudomonas aeruginosa as opsonins for phagocytosis by macrophages.

Five protein F-specific monoclonal antibodies were found to opsonize Pseudomonas aeruginosa for complement-independent phagocytosis by unelicited mouse peritoneal macrophages, mouse macrophage cell line P388D1, and human monocyte-derived macrophages. Immunoglobulin G1 antibodies seemed to be a preferred isotype.     

Coinfection with three Ehrlichia species in dogs from Thailand and Venezuela with emphasis on consideration of 16S ribosomal DNA secondary structure

As part of a larger study to investigate tick-borne infections in dogs from Thailand and Venezuela, documentation of coinfection with three Ehrlichia species in two dogs, one from each country, became the focus of the present study. Although neither dog had clinical signs attributable to ehrlichiosis, both dogs were anemic and neutropenic and the Thai dog was thrombocytopenic. Genus- and species-specific PCR targeting the 16S rRNA genes indicated that both dogs were coinfected with Ehrlichia canis, E. platys, and E. equi. To our knowledge, these results provide the first molecular documentation for the presence of E. equi in dogs from these countries. Using universal bacterial PCR primers, one nearly full-length 16S rRNA gene could be amplified from each dog. The sequences were identical to each other and almost identical to that of E. platys (AF156784), providing the first E. platys 16S ribosomal DNA (rDNA) sequences reported from these two geographically divergent countries. To determine whether these sequence differences allow differentiation between these two strains and other published 16S rDNA E. platys sequences, we performed a phylogenetic analysis of the rRNA, incorporating the consideration of secondary structure.     

Characterization of nonhuman primate epidermal and dermal dendritic cells with monoclonal antibodies. A study of Langerhans cells and indeterminate cells in the rhesus monkey

Epidermal dendritic cells (Langerhans cells) present cutaneously derived antigens to T cells in the skin and draining lymph nodes and therefore are important in many afferent immune responses. The role of dermal dendritic cells on the other hand is more obscure, although it has been suggested that these cells are precursor forms of Langerhans cells. Although human cutaneous dendritic cells have been previously characterized by using monoclonal antibodies, there are no reports of comparable studies in the skin of rhesus monkeys. By using an immunoperoxidase technique with light and immunoelectron microscopy, we have evaluated 29 antibodies raised against human cell surface antigens for their reactivity to dendritic cells in the skin of rhesus monkeys. This study demonstrates that many antisera to human cell surface antigens can be used to identify cutaneous dendritic cells in this species and that the cell populations so labeled are similar ultrastructurally to those in man. These observations represent the first demonstration of immunologic markers specific for epidermal Langerhans cells in animals, and are requisite for further study of dendritic cell function in nonhuman primate models of human immunopathologic diseases.     

Phenotypic transformation of macrophages to Langerhans cells in the skin

Langerhans cells, important participants in the cutaneous cellular immune response, are markedly diminished in skin of patients undergoing allogeneic bone marrow transplantation during the first 4 weeks after this procedure. To determine the mechanism responsible for the subsequent repopulation of these cells, the authors studied the immunophenotypic and morphologic profiles of sequential skin biopsies during the posttransplantation period. Cells with surface antigens of monocytes/macrophages within the superficial dermis were gradually replaced by dermal and epidermal dendritic cells exhibiting coexpression of monocyte/macrophage and Langerhans cell surface antigens. Ultrastructural examination revealed that many of these cells contained both prominent phagolysosomes and Birbeck granules. Antigenically and structurally mature Langerhans cells were observed within the epidermis by the end of the second month after transplantation. Phenotypic transformation of phagocytic dermal macrophages to Langerhans cells appears to represent a mechanism for repopulation of Langerhans cells during the period of immunologic reconstitution in this patient population.     

Do proficiency test results correlate with the work performance of screeners who screen Papanicolaou smears?

We rescreened Papanicolaou smear slides from 40,245 women, which had been examined by 81 cytology screeners, scored the screeners' work performance, and compared these scores with the results of the screeners' performance on glass slide and computer-based proficiency tests. All diagnoses (i.e., from the proficiency tests, the original slides, and the rescreened slides) were classified in the 4 diagnostic categories specified in the Clinical Laboratory Improvement Amendments. The rescreening scores were standardized to account for different distributions of abnormalities in the proficiency tests and rescreened slides. We compared a standardized score with the proficiency test scores. Of the cases, 91% were categorized as normal, benign, or reactive changes when rescreened, and 98% of these agreed with the original diagnosis. Sixteen percent of low-grade and 15% of high-grade intraepithelial lesions were classified as normal. The rank correlation between the rescreening scores and both proficiency tests was 0.24 using a scoring scheme for cytotechnologists. The correlation between the rescreening and proficiency testing scores indicates that performance on a 10-slide test gives some indication of the true performance of screeners. The computer-based test shows promise as an alternative to the glass slide test but needs further development and validation.     

Increased frequency of congenital chromosomal aberrations in female partners of couples undergoing intracytoplasmic sperm injection

We evaluated the frequency of congenital chromosomal aberrations in a sample of 305 couples included in an intracytoplasmic sperm injection (ICSI) programme. Twenty individuals (3.3%) with congenital chromosomal abnormalities could be identified. The following types of abnormalities were observed: reciprocal translocations (n = 7), Robertsonian translocations (n = 3), inversions (n = 3), other structural aberrations (n = 4) and sex chromosome aberrations (n = 3). The rate of chromosomally abnormal males (10/305, 3.3%) lay within the expected range for patients with reduced semen quality. Surprisingly, 50% (10/20) of all abnormal karyotypes were contributed by the female partner of ICSI patients. These data confirm the higher incidence of chromosomal aberrations in infertile populations as compared with the baseline population risk. Additionally, the data imply that in some cases of male factor infertility a hidden female chromosomal factor may be present, which cannot be identified by standard clinical evaluation. In conclusion, we recommend chromosomal analysis in both partners of couples undergoing ICSI treatment.