Serum Regulation of In Vitro Lymphocyte Responses in Early Experimental Syphilis

Sera from rabbits with early experimental syphilis were tested for their effect on in vitro lymphocyte transformation responses to related specific antigens (sonicated T. pallidum), unrelated specific antigens (sheep erythrocytes), and the T cell mitogen, concanavalin A. Results were compared with responses in preinfection sera and in sera from sham-infected rabbits. Titration experiments in which normal serum was used indicated that optimal lymphocyte responsiveness is obtained with a final serum concentration of 1%. Under these conditions, no differences in concanavalin A stimulation were observed in cultures with syphilitic sera. Responses to sonicated T. pallidum were inhibited, but only by 17 to 25% when compared with the response in preinfection sera. In cultures containing 10% serum, inhibition of lymphocyte proliferation to sonicated T. pallidum antigens was evident with sera from all syphilitic animals from day 10 (55% inhibition) through day 31 (80% inhibition) of infection. Responses to concanavalin A and sheep erythrocytes were significantly inhibited by day 10 sera; only 20% of the sera tested demonstrated substantial nonspecific inhibitory capacity. No differences were evident among sera from any of the sham-infected animals or among the preinfection sera from either group. Pooled serum with high inhibitory activity was fractionated by ammonium sulfate precipitation, DEAE ion exchange chromatography, and Sephadex G-200 gel filtration. Two separate inhibitors were identified: (i) a low-molecular-weight, ammonium sulfate-soluble, nonspecific inhibitory fraction containing albumin and alpha-globulins with the capacity to inhibit both antigen and mitogen responses and (ii) a high-molecular-weight, ammonium sulfate-precipitable, inhibitory fraction containing alpha-globulin and FTA-ABS-reactive immunoglobulin M which affected only the antigen-specific response to sonicated T. pallidum. Immunodiffusion failed to detect immunoglobulin or T. pallidum antigens in either fraction. DEAE-purified immunoglobulin G from immune serum was not inhibitory.     

Transformation of rat cells by the hybrid virus Ad2(2+) HEY.

A set of four isogenic rat cell lines transformed by Ad22+ HEY have been studied. While all of the cell lines synthesize SV40 T antigen, only one expresses adenovirus 2 T antigen: none expresses SV40 V antigen or adenovirus 2 fibre antigen. Three cell lines contain 1 to 2 virus equivalents of SV40 and adenoviral sequences per diploid quantity of rate cell DNA and the fourth line contains five copies of SV40 and 20 copies of the adenovirus genome. At least three of the cell lines contain DNA sequences from the helper adenovirus 2 in addition to sequences from the Ad2+ HEY genome. The patterns of integrated virus sequences are complex suggesting multiple insertions of both adenovirus and SV40 DNA sequences. SV40 can be rescued from three cell lines by fusion with permissive cells.     

Missed diagnosis in hematological patients—an autopsy study

Autopsy findings of missed diagnoses that would probably have changed management or prognosis occur in up to 29% of cases in general hospitals. Such proportions may be higher in subsets of patients with complex diseases. We reviewed 2908 consecutive autopsies performed over a period of 29 months in a large-volume hospital, analyzing 118 autopsies of patients with hematological malignancies or severe aplastic anemia. A review of macroscopic reports as well as microscopic examination of tissue samples was performed. Medical records were reviewed for clinical diagnoses. Discordances between clinical and autopsy diagnoses were classified using Goldmans criteria. Additionally, we searched for clinical parameters correlated with occurrence of class-I discrepancy using a multivariate method. Median age was 46.5 years, and 25.4% had received a hematopoietic stem-cell transplant. Overall, 11.9% (6.6–19.1%) of patients died before conclusion of the hematological diagnosis and 33% (24.6–42.3%) died with no active hematological disease. We found class-I discrepancy in 31.3% (23.1–40.5 %) of cases. The most common among these diagnoses were hematological disease, pneumonia and gastrointestinal bleeding. In a univariate analysis, being elderly (P=0.04) was positively correlated with the finding of class-I discrepancies; while, having received previous specific hematological treatment (P=0.0005) or hematopoietic stem-cell transplants (P=0.013), or being admitted to a specialized hematology unit (P=0.0006) were negatively correlated to the occurrence of such discrepancies. Multivariate analysis showed that care in a specialized hematology unit (OR 0.34, 0.12–0.93) was independently associated with lower occurrence of discrepancies. We concluded that critical diagnoses are often missed in highly complex hematological patients especially in the absence of admission to specialized hematology units.     

Amiloride prevents amphotericin B related hypokalaemia in neutropenic patients.

Twenty neutropenic patients with various haematological disorders were randomised prospectively to receive either intravenous amphotericin B alone or amphotericin B and oral amiloride 5 mg twice a day for treatment of confirmed or suspected fungal infection. Patients receiving amiloride had a significantly higher plasma potassium (p less than 0.01), a significantly lower urinary potassium loss (p less than 0.01), and required significantly less potassium chloride supplementation to maintain their plasma potassium within the normal range (p less than 0.001). Amiloride was well tolerated, had no clinically important side effects, and provided effective control of plasma potassium in patients treated with amphotericin B.     

Proton spectroscopy study of the left dorsolateral prefrontal cortex in pediatric depressed patients

The dorsolateral prefrontal cortex (DLPFC) plays an essential role in mood regulation and integration of cognitive functions that are abnormal in major depressive disorder (MDD). Few neuroimaging studies have evaluated the still maturing DLPFC in depressed children and adolescents. We conducted single voxel proton magnetic resonance spectroscopy ((1)H MRS) of the left DLPFC in 14 depressed children and adolescents (13.3 +/- 2.3 years old, 10 males) and 22 matched healthy controls (13.6 +/- 2.8 years old, 13 males). Depressed subjects had significantly lower levels of glycerophosphocholine plus phosphocholine (GPC + PC; or choline-containing compounds) and higher myo-inositol levels in the left DLPFC compared to healthy controls. In the depressed subjects, we found significant inverse correlations between glutamate levels and both duration of illness and number of episodes. In healthy controls there was a significant direct correlation between age and glutamine levels, which was not present in the patient group. Lower GPC + PC levels in pediatric MDD may reflect lower cell membrane content per volume in the DLPFC. Increased myo-inositol levels in MDD may represent a disturbed secondary messenger system. GPC + PC and myo-inositol abnormalities further demonstrate the involvement of DLPFC in pediatric MDD.     

Association of DLG5 R30Q variant with inflammatory bowel disease

Crohn's disease (CD) and ulcerative colitis (UC) are chronic inflammatory diseases of the gastrointestinal system known as the inflammatory bowel diseases (IBD). Recently, Stoll and colleagues reported a novel finding of genetic variation in the DLG5 gene that is associated with IBD (CD and UC combined). We present here a study of the genetic variation described in that report in two well-powered, independent case-control cohorts and one family-based collection, and confirm the proposed association between IBD and the R30Q variant of DLG5 in two of the three studies. We are, however, unable to replicate the other proposed association to the common haplotype described in Stoll et al and suggest that this other finding could conceivably have been partially a statistical fluctuation and partially a result of LD with the replicated R30Q association. This study provides support for the hypothesis that DLG5 constitutes a true IBD risk factor of modest effect.     

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.     

Hepatitis B virus transmission in Brazilian hemodialysis units: serological and molecular follow-up

A serological and molecular study of hepatitis B virus (HBV) infection was carried out in dialysis units in Central Brazil. Between 1995 and 1999, serum samples from all HBsAg-positive hemodialysis patients (n = 43) were tested for HBeAg/anti-HBe and subtyping by monoclonal ELISA. HBV DNA was detected by PCR and positive samples were genotyped by restriction fragment polymorphism pattern (RFLP) methodology. TheHBsAg prevalence declined in this population during the survey period (12-5.8%). HBeAg and anti-HBe were detected in 23 (53.5%) and 18 (41.9%) sera, respectively. Thirty-six samples could be HBsAg subtyped: 21 were subtype ayw(3), 14 belonged to adw(2) and one was identified as adw(4). HBV DNA was present in 30 serum samples. Of these, 20 (66.7%) were genotype D, 9 (30%) genotype A, and 1 (3.3%) genotype F. In addition, the RFLP pattern could be determined in samples from 18/20 genotype D patients: D3 (10 strains), D7 (7 strains) and D4 (1 strain); from 8/9 genotype A patients: A1 (6 strains) and A3 (2 strains); and from the patient infected with genotype F: F1. Patterns D3 and D7 were associated closely with HBV infection in the two largest hemodialysis units studied. These findings confirm the value of the RFLP method as an effective molecular epidemiological tool for elucidating HBV transmission in hemodialysis units.