Basic isoferritin and hypercalcaemia in renal cell carcinoma

A 63-year-old man with iron loss anaemia and hypercalcaemia was found to have a renal cell carcinoma. Despite the iron-deficient blood and bone marrow picture, the serum ferritin concentration was markedly raised. This was mainly due to a “basic isoferritin”. The serum parathormone concentration was normal. The serum ferritin and calcium concentrations returned to normal after the tumour was removed. We propose that the renal cell carcinoma cells in this patient secreted the basic isoferritin as well as humoral factor(s) responsible for hypercalcaemia.     

Sialidases (neuraminidases) in bacterial vaginosis and bacterial vaginosis-associated microflora.

Bacterial vaginosis, Prevotella species, and Bacteroides species have been associated with prematurity and upper genital tract infection. Prevotella (Bacteroides) species and Bacteroides fragilis have also been associated with preterm birth. However, the mechanism by which lower genital tract infection causes upper genital tract disease remains poorly understood. Sialidases (neuraminidases) are enzymes which enhance the ability of microorganisms to invade and destroy tissue. Elevated levels of sialidase activity were detected in 42 (84%) of 50 vaginal fluid specimens from women with bacterial vaginosis and none of 19 vaginal fluids from women without bacterial vaginosis (P less than 0.001). Vaginal fluid from women with bacterial vaginosis had a median specific activity of 9.8 U compared to 2.5 U of sialidase in women without bacterial vaginosis (P less than 0.001). In order to determine the probable source of sialidases in vaginal fluid, the microorganisms recovered from women with bacterial vaginosis before and after treatment were assayed. Of 28 specimens from women with bacterial vaginosis, 27 (96%) yielded sialidase-positive bacteria, at a median concentration of 10(6.5) CFU/ml of vaginal fluid. Prevotella and Bacteroides species accounted for the sialidase activity in 26 of the vaginal fluids, and Gardnerella vaginalis accounted for the sialidase activity in the remaining fluid. After treatment, sialidase was detected in the vaginal fluid of 1 (5%) of 22 women who responded to therapy and in all of 6 women for whom therapy failed. These data suggest that vaginal fluid sialidase is highly correlated with bacterial vaginosis and that the probable sources for this enzyme activity are the Bacteroides and Prevotella species present in the vagina.     

Comparative analysis of genetic variability among Candida albicans isolates from different geographic locales by three genotypic methods.

The objective of the present study was to conduct a comparative genotypic analysis of Candida albicans isolates from the United States, Europe, and Southeast Asia to determine whether differences between isolates might be associated with geographic locations. The genotypes of 86 unrelated isolates of C. albicans (from the United States and Europe) and 26 isolates from Singapore were examined by three DNA typing methods. Computer-assisted methods were used to analyze the gel patterns for all isolates. A dendrogram based on the overall similarity of the patterns obtained by restriction endonuclease analysis (REA) with EcoRI clustered the U.S. and European isolates into two major groups (groups A and B). The Singaporean isolates demonstrated unique REA profiles, with nine isolates having both or neither of the REA-characteristic 3.7- and 4.2-kb bands present in groups A and B. By REA profiles, the Singaporean isolates were related to each other with similarity values (S(AB)s) of > 0.80, but only one isolate mixed with the U.S. and European isolates at this S(AB) (an arbitrary threshold for genetic similarity). Randomly amplified polymorphic DNA (RAPD) analysis generated DNA profiles that clustered the C. albicans isolates into approximately the same number of distinct typing groups as REA. However, isolates identical to each other by REA were generally different from each other by RAPD analysis. In a composite dendrogram prepared from the results obtained by RAPD analysis, the isolates from the United States and Europe clustered in major groups with S(AB)s of > 0.85, while Singaporean isolates connected to these clusters at S(AB)s of > or = 0.75. Pulsed-field gel electrophoresis was less discriminatory, discerning about one-third as many distinct subtypes as REA or RAPD analysis; the Singaporean isolates were distributed randomly with the U.S. and European isolates. These results suggest that a high degree of genetic diversity exists between C. albicans isolates from Southeast Asia and those from the United States and Europe.     

Human IgG anti-F(ab'')2 antibodies possess rheumatoid factor activity.

Individual preparations of affinity purified anti-F(ab')2 antibodies and anti-Fc antibodies isolated from the sera of patients with rheumatoid arthritis (RA), were examined for reactivity with the Fab and Fc fragments of human IgG. Western blot assays demonstrated specific interaction of affinity-purified anti-Fab antibodies with both Fab and Fc molecules. Approximately one-half of the anti-Fab antibody preparations studied contained IgG antibodies reactive with Fab and Fc fragments in ELISA, suggesting the existence of naturally occurring epibody-like autoantibodies in these patients. Thirteen of 14 affinity-purified anti-Fc antibody preparations contained IgG cross-reactive with Fab molecules in ELISA. Double-adsorption assays on affinity columns demonstrated that a minimum of 14%, and possibly as much as 50%, of the IgG anti-Fab antibodies reacted with the Fc of IgG. Conversely, a minimum of 12%, and possibly as much as 70%, of the IgG anti-Fc antibodies reacted with IgG Fab molecules. Anti-Fab antibodies isolated from non-RA individuals also exhibited anti-Fc reactivity in ELISA, demonstrating the presence of these dual-reactive antibodies in other autoimmune and normal individuals. These studies establish the presence of naturally occurring IgG autoantibodies reactive with both the Fab and Fc fragments of human IgG. Their existence emphasizes the potential of anti-immunoglobulin antibodies to recognize a multiplicity of antigens, possibly including other members of the immunoglobulin supergene family.     

Evaluation of two BBL Crystal systems for identification of some clinically important gram-negative bacteria.

The BBL Crystal system (Becton Dickinson Microbiology Systems, Cockeysville, Md.) is a miniaturized bacterial identification method employing modified conventional and chromogenic substrates. Two products are currently available, the Rapid Stool/Enteric ID Kit and the Enteric/Nonfermenter ID Kit, each comprising thirty tests. We report an evaluation of both systems (using database version 1.1 for both) in the identification of 51 gram-negative taxa likely to be encountered commonly in the clinical laboratory. In all, 266 strains were tested in the Enteric/Nonfermenter ID Kit, and these represented 36 taxa of the family Enterobacteriaceae (188 strains), 5 oxidase-positive fermentative taxa (26 strains), and 10 nonfermentative taxa (52 strains). The majority of these same strains (203 of 266) were also tested in the Rapid Stool/Enteric ID Kit. The Enteric/Nonfermenter ID Kit performed as follows: Enterobacteriaceae, 93% correct, 6% not identified, and 1% incorrect; oxidase-positive fermenters, 88, 12, and 0%, respectively; and nonfermenters, 100% correct, although several only to the genus or group level. The Rapid Stool/Enteric ID Kit gave the following results: Enterobacteriaceae, 91% correct, 7% not identified, and 2% incorrect; oxidase-positive fermenters, 80, 13, and 7%, respectively (but results were based on only 15 strains); and nonfermenters, 100% correct (but results were based on only 11 strains). We found the systems extremely easy and rapid to use, and for the Enteric/Nonfermenter ID Kit an identification rate of 100% in 40 of 51 taxa was achieved, with corresponding figures of 29 of 39 taxa for the Rapid Stool/Enteric ID Kit.     

Detection and quantitation of human immunodeficiency virus-infected peripheral blood mononuclear cells by flow cytometry.

A flow cytometric assay has been developed to detect and quantitate human immunodeficiency virus (HIV)-infected peripheral blood mononuclear cells obtained from HIV-seropositive patients. Peripheral blood was obtained from patients attending an acquired immune deficiency syndrome clinic, and mononuclear cells were separated by centrifugation onto Ficoll-Hypaque. The cell layer at the interface was removed, washed in phosphate-buffered saline without Ca2+ and Mg2+, and fixed with 90% methanol, and intracellular HIV antigens were detected by indirect immunofluorescence with monoclonal antibodies to HIV antigens as the primary antibody and fluorescein isothiocyanate-conjugated goat anti-mouse immunoglobulin G F(ab')2 antibody as the secondary antibody. DNA content was determined by propidium diiodide staining after RNase treatment. These fluorochrome-treated cells were analyzed for two-color fluorescence by flow cytometry. The results showed that HIV-infected cells in peripheral blood that have been treated with monoclonal antibodies to the p24 or nef antigens of HIV can be detected and quantitated by flow cytometry. The percentage of p24 antigen-positive mononuclear cells had a significant correlation (P = 0.0001) with the clinical status of the patient, i.e., those with a high percentage of p24 antigen-positive cells had a poorer prognosis than those with a lower percentage of p24 antigen-positive mononuclear cells. In addition, for those in Centers for Disease Control groups III and IV, there was an inverse correlation between the percentage of p24 antigen-positive mononuclear cells and the number of T4 cells. However, cell-associated antigen detection by flow cytometry did not correlate with detection of antigen in sera of HIV-seropositive patients by the standard antigen capture enzyme-linked immunosorbent assay. This lack of correlation was probably due to the presence of immune complexes in the sera of HIV-seropositive patients. These results suggest that flow cytometry can be used as a rapid, sensitive, and quantitative assay system for the determination of the antigen status of HIV-seropositive patients and that it may be more useful as an indicator of disease progression than the currently used antigen detection methods.     

Epstein-Barr virus-specific serum immunoglobulin A as an acute-phase antibody in infectious mononucleosis.

Immunoglobulin A (IgA) antibodies to Epstein-Barr virus viral capsid antigen were assayed serially in 19 patients with infectious mononucleosis and in 38 controls. Seventy-four percent of infectious mononucleosis patients demonstrated IgA antibody, whereas this was found in 13% of controls. This antibody appeared early in infectious mononucleosis and was virtually gone 10 weeks after onset. Comparison of IgA antibody kinetics was made with IgG and IgM antibodies to viral capsid antigen, heterophile antibody, and antibody to Epstein-Barr virus early antigen and nuclear antigen. Failure to demonstrate IgA antibody was associated with severe illness, prolonged illness, delay in IgG and anti-Epstein-Barr virus nuclear antigen antibody, and low or absent heterophile and anti-early antigen antibody. Assay of IgA antibody to viral capsid antigen is a potentially useful adjunct in the serodiagnosis of infectious mononucleosis or recent Epstein-Barr virus infection, as are the other antibodies tested, but in this study IgM viral capsid antigen antibody was the only acute-phase antibody present in all patients.     

Comparison of Southern transfer hybridization and dot filter hybridization for detection of cervical human papillomavirus infection with types 6, 11, 16, 18, 31, 33, and 35

A commercial dot filter hybridization kit (Virapap Kit) was compared with Southern transfer hybridization for the detection of seven types of human papillomavirus (HPV) in cervical specimens from 450 consecutive females attending a sexually transmitted diseases clinic. In comparison with Southern transfer hybridization, performed with the same probes used in the dot filter kit, the sensitivity, specificity, and positive and negative predictive values of dot filter hybridization were 90%, 94%, 74%, and 98%, respectively. Among patients with cervical cytologic dysplasia, HPV DNA was detected in 44% by dot filter hybridization and in 35% by Southern transfer hybridization. Although 26% of specimens positive by dot filter hybridization were not confirmed by Southern transfer hybridization, cervical dysplasia was detected in 5 (25%) of 20 with HPV DNA detected by dot filter hybridization alone, compared with 25 (8%) of those with no definitive evidence of HPV by either method (P = 0.009) and with 16 (30%) of 53 with HPV DNA detected by both methods (P = 0.7). The kappa statistic for interobserver and intraobserver reproducibility for interpretation of blots was similar for the two methods. The dot filter hybridization method evaluated appears to be a satisfactory alternative to Southern transfer hybridization for detection of HPV DNA.     

Marek's disease as a model for the Landry--Guillain--Barré syndrome: latent viral infection in nonneuronal cells accompanied by specific immune responses to peripheral nerve and myelin.

In the chicken, Marek's disease virus (MDV) induces a demyelinating peripheral neuropathy that, early in the course of the disease, is histopathologically indistinguishable from that seen in the Landry--Guillain--Barré syndrome in man. A continuing role for a productive infection in the pathogenesis of this disease is unlikely, since neither MDV nor MDV antigens can be characteristically detected in nerves or spinal ganglia examined at necropsy. The authors investigated the possible role of a latent viral infection by explanting and maintaining in vitro the sciatic nerves and spinal ganglia from diseased birds. In these tissues, viral specific products were induced and detected by immunofluorescence and ultrastructural methods early after explanation in well-isolated Schwann cells, satellite cells, and lymphocytes. Later, virus was detected in fibroblasts, macrophages, and neoplastic lymphoblastoid cells. Neurons and myelinating Schwann cells, in contrast, did not replicate the agent. Specific cell-mediated and humoral immune responses to chicken peripheral nerve and peripheral nerve myelin were demonstrated early in the course of the disease. When considered relative to potential pathogenetic mechanisms, these results suggest that Marek's disease neuropathy is initiated by the establishment of a latent viral infection in neuronal supporting cells. A specific immune response to viral-induced antigens on these cells could, in turn, result in subsequent demyelination.     

Atypical polypoid adenomyoma: a case report with ultrastructural examination

A case of atypical polypoid adenomyoma occurring in a 40 yr-old female is reported. The lesion was composed of irregular glands lined by atypical epithelium lying in a spindle cell stroma containing smooth muscle cells. The mitotic count of the stroma was less than 1 per 10 high power fields. Squamous metaplasia was present in the glandular elements. Ultrastructural examination of the stroma confirmed the presence of smooth muscle cells. The lesion is compared with similar cases previously reported. The differential diagnosis is considered, including endometrial adenocarcinoma, adenomyosis, endometrial polyps and mixed Mullerian tumours. Atypical polypoid adenomyoma is a benign lesion, and conservative management is recommended.