Interstitial chemotherapy with carmustine-loaded polymers for high-grade gliomas: a randomized double-blind study

OBJECTIVE

To find out the effect of carmustine (bischloroethyl-nitrosourea) combined with a biodegradable polymer in the treatment of malignant (Grades III and IV) gliomas, applied locally, at the time of the primary operation.

METHODS

Prospective, randomized double-blind study of an active treatment group versus a placebo group. Conducted at the Departments of Neurosurgery of the University Hospitals of Helsinki, Tampere, and Turku in Finland and Trondheim in Norway. The study consisted of 32 patients (16 in each treatment group) enrolled between March 23, 1992, and March 19, 1993. The study was planned to include 100 patients but had to be terminated prematurely, because the drug that was being used had become unobtainable. The main outcome measures included the survival times of patients after the operations and the application of an active drug or placebo.

RESULTS

The median time from surgery to death was 58.1 weeks for the active treatment group versus 39.9 weeks for the placebo group (P = 0.012). For 27 patients with Grade IV tumors, the corresponding times were 39.9 weeks for the placebo group and 53.3 weeks for the active treatment group (P = 0.008). At the end of the study, six patients were still alive, five of whom belonged to the active treatment group.

CONCLUSION

Carmustine applied locally in a biodegradable polymer at the time of primary operation, seems to have a favorable effect on the life span of patients with high-grade gliomas.

Infections, inflammation, and the risk of coronary heart disease

BACKGROUND

The role of infections and inflammation in the pathophysiology of coronary heart disease is emerging. We studied the independent and joint effects of these 2 components on coronary risk.

METHODS AND RESULTS

We measured baseline levels of C-reactive protein (CRP) and antibodies to adenovirus, enterovirus, cytomegalovirus, and herpes simplex virus as well as to Chlamydia pneumoniae (Cpn) and Helicobacter pylori in 241 subjects who suffered either myocardial infarction or coronary death during the 8.5-year trial in the Helsinki Heart Study, a coronary primary prevention trial. The 241 controls in this nested case-control study were subjects who completed the study without coronary events. Antibody levels to herpes simplex type I (HSV-1) and to Cpn were higher in cases than in controls, whereas the distributions of antibodies to other infectious agents were similar. Mean CRP was higher in cases (4.4 versus 2.0 mg/L; P<0.001), and high CRP increased the risks associated with smoking and with high antimicrobial antibody levels. The odds ratios in subjects with high antibody and high CRP levels were 25.4 (95% CI 2.9-220.3) for HSV-1 and 5.4 (95% CI 2.4-12.4) for Cpn compared with subjects with low antibody levels and low CRP. High antibody levels to either HSV-1 or to Cpn increased the risk independently of the other, and their joint effect was close to additive.

CONCLUSIONS

Two chronic infections, HSV-1 and Cpn, increase the risk of coronary heart disease. The effect is emphasized in subjects with ongoing inflammation, denoted by increased CRP levels.

Direct amplification of rRNA genes in diagnosis of bacterial infections

A broad-range bacterial PCR targeting rRNA genes (rDNAs) was used to directly analyze 536 clinical samples obtained from 459 hospitalized patients during a 4-year study period. The molecular diagnosis based on DNA sequencing of the PCR product was compared to that obtained by bacterial culture. The bacteriological diagnosis was concordant for 447 (83%) specimens. Broad-range rDNA PCR was the only method that yielded an etiologic diagnosis for 11 (2.4%) of 459 patients. Compared to culture and clinical assessment, the sensitivity of the PCR method combined with sequencing was 74.2%, and the specificity was between 98.7 and 99.6%. At present, the described molecular approach proved superior to bacterial culture in two clinical situations: infections caused by bacteria with unusual growth requirements and specimens taken during antimicrobial treatment of the patient.

Influence of major histocompatibility complex on bacterial composition of fecal flora

Very little is known about how the host genome influences the composition of the gastrointestinal flora, largely due to the great number and diversity of bacteria present in the flora and the difficulties of using traditional methods of bacterial isolation and identification. We have approached the problem by studying bacterium-derived cellular fatty acids in the stool samples of six mouse strains congenic for the major histocompatibility complex (MHC). The results obtained indicate that the composition of the fecal flora is genetically regulated. In addition to undefined gene loci, MHC alone has a pronounced effect, since mice with different MHC in the same background have significantly different fecal floras. Demonstration of the genetic influence on the gastrointestinal flora opens a new approach to studying the pathogenesis of bacterially induced diseases.

Molecular and chemical characterization of the lipopolysaccharide O-antigen and its role in the virulence of Yersinia enterocolitica serotype O:8

The Y. enterocolitica O:8(YeO8) O-antigen repeat units consist of five sugar residues: N-acetyl-D-galactosamine (GalNAc), D-galactose (Gal), D-mannose (Man), L-fucose (Fuc), and 6-deoxy-D-gulose (6d-Gul). The nucleotide sequence of the O-antigen gene cluster of the YeO8 strain 8081-c was determined. Altogether, 18 open reading frames (ORFs) were identified and shown to be essential for O-antigen biosynthesis. We previously characterized the 3'-end of the O-antigen gene cluster and identified four genes: two for GDP-Man biosynthesis, one for UDP-Gal biosynthesis, and one for O-antigen polymerase. Based on sequence similarity, Tn5-insertion phenotypes and chemical analysis, the 14 new genes were assigned the following functions: four genes are involved in the biosynthesis of CDP-6d-Gul and two in GDP-Fuc biosynthesis. Five gene products were assigned sugar transferase functions and one gene product was similar to Wzx, the O-antigen flippase. Two genes remained unassigned. By genetic complementation we also showed that YeO8 O-antigen biosynthesis was dependent on N-acetyl-glucosaminyl:undecaprenylphosphate transferase (GlcNAc transferase), the WecA (formerly known as Rfe) protein. Data obtained from chemical-composition analysis suggest that in addition to being GlcNAc transferase, WecA may also function as a GalNAc transferase. Using a restriction-deficient derivative of Y. enterocolitica O:8 strain 8081, a rough mutant, designated 8081-R2, was isolated. 8081-R2 was complemented in trans with a cloned O-antigen gene cluster restoring surface O-antigen expression. The virulence of the wild-type strain and that of the complemented strain were significantly higher (approx. 100-fold) than that of the rough mutant in an orally infected mouse model, showing that YeO8 O-antigen is a virulence factor.

A novel locus of Yersinia enterocolitica serotype O:3 involved in lipopolysaccharide outer core biosynthesis

Yersinia enterocolitica serotype O:3 strain 6471/76-c (YeO3-c) was sensitive to bacteriophage phi R1-37 when grown at 37 degrees C but not when grown at 22 degrees C because of steric hindrance by abundant lipopolysaccharide (LPS) O-side chain (O-antigen) expressed at 22 degrees C. The transposon library of YeO3-c was grown at 37 degrees C and screened for phage phi R1-37-resistant transposon insertion mutants. Three types of mutant were isolated: (i) phage receptor mutants expressing O-antigen (LPS-smooth), (ii) phage receptor mutants not expressing O-antigen (LPS-rough), and (iii) LPS-smooth mutants with the phage receptor constitutively sterically blocked. Mutant type (i) was characterized in detail; the transposon insertion inactivates an operon, named the trs operon. The main findings based on this mutant are: (i) the frs operon is involved in the biosynthesis of the LPS outer core in YeO3-c; the nucleotide sequence of the trs operon revealed eight novel genes showing similarly to known polysaccharide biosynthetic genes of various Gram-negative bacteria as well as to capsule biosynthesis genes of Staphylococcus aureus; (ii) the biosynthesis of the core of YeO3-c involves at least two genetic loci; (iii) the trs operon is required for the biosynthesis of the bacteriophage phi R1-37 receptor structures; (iv) the homopolymeric O-antigen of YeO3-c is ligated to the inner core in Y. enterocolitica O:3; (v) the trs operon is located between the adk-hemH and galE-gsk gene pairs in the Y. enterocolitica chromosome; and (vi) the phage phi R1-37 receptor is present in many but not in all Y. enterocolitica serotypes. The results also allow us to speculate that the trs operon is a relic of the ancestral rfb region of Y. enterocolitica O:3 carrying genes indispensable for the completion of the core polysaccharide biosynthesis.

Hydrophobic domains affect the collagen-binding specificity and surface polymerization as well as the virulence potential of the YadA protein of Yersinia enterocolitica

The YadA surface protein of enteropathogenic Yersinia species contains two highly hydrophobic regions: one close to the amino terminal, and the other at the carboxy-terminal end of the YadA polypeptide. To study the role of these hydrophobic regions, we constructed 66 bp deletion mutants of the yadA genes of Yersinia enterocolitica serotype O:3 strain 6471/76 (YeO3) and of O:8 strain 8081 (YeO8). The mutant proteins, YadAYeO3-delta 83-104 and YadAYeO8-delta 8O-101, lacked 22 amino acids from the amino-terminal hydrophobic region, formed fibrillae and were expressed on the cell surface. Bacteria expressing the mutated protein lost their auto-agglutination potential as well as their collagen-binding property. Binding to fibronectin and laminin was affected differently in the YeO3 and the YeO8 constructs. The deletion did not influence YadA-mediated complement inhibition. Loss of the collagen-binding property was associated with loss of virulence in mice. We also constructed a number of YadAYeO3 deletion mutants lacking the hydrophobic carboxy-terminal end of the protein. Deletions ranging from 19 to 79 amino acids from the carboxy terminus affected polymerization of the YadA subunits, and also resulted in the loss of the YadA expression on the cell surface. This suggests that the carboxy terminus of YadA is involved in transport of the protein to the bacterial outer surface.

Interleukin-10 functions as an antiinflammatory cytokine in rheumatoid synovium

OBJECTIVE

Interleukin-10 (IL-10) is an antiinflammatory cytokine that has been shown to play a role in rheumatoid arthritis (RA). We therefore investigated the effects of IL-10 on the function and phenotype of synovial fluid mononuclear cells (SFMC) derived from patients with RA. In addition, we studied the production of IL-10 in rheumatoid joints, and the role of endogenous IL-10 in the regulation of SFMC function.

METHODS

The presence of IL-10 in rheumatoid joints was studied using IL-10-specific enzyme-linked immunosorbent assay (ELISA) and reverse transcriptase- polymerase chain reaction (RT-PCR) techniques. The effects of recombinant human IL-10 or neutralizing anti-IL-10 monoclonal antibodies (MAbs) on both cytokine production and phenotype of SFMC were evaluated using cytokine-specific ELISAs and flow cytometry. The effect of IL-10 on proliferation of SFMC was determined by incorporation of tritiated thymidine.

RESULTS

IL-10 was detected by ELISA in 22 of 23 SF samples, and was spontaneously produced by cultured SFMC. IL-10 messenger RNA was detectable in all 8 SFMC samples, as determined by RT-PCR. Neutralization of endogenously produced IL-10 by anti- IL-10 MAbs resulted in increased production of IL-1 beta, tumor necrosis factor alpha (TNF alpha), and granulocyte- macrophage colony-stimulating factor (GM-CSF) by SFMC, and in enhanced proliferation of SFMC. In particular, the production of TNFalpha was dramatically increased by anti-IL-10 MAbs. Moreover, the expression of HLA-DR molecules by SF macrophages was increased, and the expression of CD16 was decreased by anti-IL-10 MAbs. In contrast, addition of recombinant IL-10 significantly decreased the production of IL-1 beta, TNF alpha, and GM-CSF by SFMC, and decreased spontaneous and IL-2-induced proliferation of SFMC. Finally, IL-10 decreased HLA-DR expression and increased the expression of the Fc gamma receptors, CD16 and CD64, by SF macrophages.

CONCLUSION

These data indicate that endogenously produced IL-10 functions as an immunoregulatory molecule in rheumatoid synovium. Importantly, exogenous IL-10 has potent antiinflammatory effects on SFMC, suggesting that IL-10 may be useful in the treatment of patients with RA.

Sex ratio of newborns: preponderance of males in toxemia of pregnancy

The ratio of males to females in 1061 babies born to mothers with toxemia of pregnancy is 1.24. The ratio increases as the severity of the disease increases, being 1.71 in cases in which the urinary output of protein is equal to or greater than 3 grams per 24 hours. Histoincompatibility of the fetus and mother, including incompatibility due to an antigen (or antigens) dependent on the Y chromosome, is suggested to function in the pathogenesis of pregnancy toxemia.

Persistence of Yersinia antigens in peripheral blood cells from patients with Yersinia enterocolitica O:3 infection with or without reactive arthritis

OBJECTIVE

To assess the persistence of bacterial antigens in peripheral blood cells from patients with Yersinia enterocolitica O:3-triggered reactive arthritis (ReA).

METHODS

Peripheral blood samples were obtained from 20 patients with Y. enterocolitica O:3 infection (11 with ReA and 9 without). These samples were studied by immunochemical techniques for the presence of Yersinia antigens at the beginning of infection and up to 4 years thereafter. Synovial fluid samples from 6 of the 11 ReA patients were also studied.

RESULTS

The Yersinia antigens lipopolysaccharide and heat-shock protein (HSP) were detected in peripheral blood mononuclear cells and polymorphonuclear phagocytes from all patients studied at the early phase of the disease. They were also found in the synovial fluid cells of patients with Yersinia-triggered ReA. At 4 years after the onset of infection, these bacterial antigens were still detected in the peripheral blood cells of most of the ReA patients studied.

CONCLUSION

This study has, for the first time, directly demonstrated that bacterial antigens persist for a long time in patients who develop ReA after Y. enterocolitica O:3 infection. The finding of bacterial HSP in synovial fluid cells could provide a link to the pathogenesis of ReA, since T cell responses of synovial cells have been shown to be directed against that structure. A close similarity between the bacterial and host HSP might contribute to the development of the relatively common, chronic form of this complication.

Genetic organization and sequence of the rfb gene cluster of Yersinia enterocolitica serotype O:3: similarities to the dTDP-L-rhamnose biosynthesis pathway of Salmonella and to the bacterial polysaccharide transport systems

The Yersinia enterocolitica O:3 lipopolysaccharide O-antigen is a homopolymer of 6-deoxy-L-altrose. The cloned rfb region was sequenced, and 10 open reading frames were identified. Transposon mutagenesis, deletion analysis and transcomplementation experiments showed that eight of the genes, organized into two operons, rfbABC and rfbDEFGH, are essential for O-antigen synthesis. Functional tandem promoters were identified upstream of both operons. Of the deduced polypeptides RfbA, RfbF and RfbG were similar to Salmonella proteins involved in the dTDP-L-rhamnose biosynthesis. Rhamnose and 6-deoxy-L-altrose are C3-epimers suggesting that analogous pathways function in their biosynthesis. RfbD and RfbE were similar to capsular polysaccharide export proteins, e.g. KpsM and KpsT of Escherichia coli. This and transposon mutagenesis showed that RfbD and RfbE function as O-antigen exporters.

LcrF is the temperature-regulated activator of the yadA gene of Yersinia enterocolitica and Yersinia pseudotuberculosis

The virulence plasmid of human pathogenic Yersinia species, pYV, encodes secreted proteins, Yop proteins, and an outer membrane protein, YadA. YadA has been associated with binding to a variety of substrates and with interference with host defense. YadA is regulated by temperature and is expressed only at 37 degrees C. Unlike the yop regulon, the yadA gene is not under Ca2+ regulation. Here, we show that LcrF (VirF), the temperature-regulated activator of the yop regulon, also acts as an activator for yadA.

Application of the polymerase chain reaction and immunofluorescence techniques to the detection of bacteria in Yersinia-triggered reactive arthritis

Leukocytes in synovial fluid and peripheral blood samples from patients with Yersinia-triggered reactive arthritis were analyzed after DNA amplification using the polymerase chain reaction. The primers applied were specific for the virulence plasmid-coded 1crE genes of Yersinia enterocolitica O:3 and Yersinia pseudotuberculosis III. No Yersinia DNA was observed within the synovial fluid cells or peripheral blood cells by polymerase chain reaction techniques. However, Yersinia antigens were detected in the synovial fluid cells by immunofluorescence techniques. These results suggest that only parts of the causative agents, not the entire microbe, can enter the joint and initiate the inflammation that leads to a reactive arthritis.

Use of the polymerase chain reaction and DNA sequencing for detection of Bartonella quintana in the aortic valve of a patient with culture-negative infective endocarditis

We used the polymerase chain reaction (PCR) and broad-range bacterial primers, combined with DNA sequencing, to identify Bartonella quintana as the etiologic agent in a case of culture-negative infective endocarditis; all blood cultures, as well as the bacterial cultures of the resected aortic valve and vegetations, remained negative. PCR was used to amplify bacterial 16S rDNA from a template prepared from the aortic valve vegetation. The amplified 16S rDNA produced a nucleotide sequence that was 99.79% identical to the B. quintana rDNA sequence. The patient had a highly elevated level of serum antibodies to Bartonella antigen (1:8,192).

Bacterial 16S rDNA polymerase chain reaction in the detection of intra-amniotic infection

OBJECTIVE

Bacterial polymerase chain reaction (PCR) was used to detect early subclinical intraamhiotic infection. We used universal primers which amplify a DNA fragment of 16S ribosomal DNA (rDNA) from all known bacteria and sequenced the positive samples to identify the bacterial species.

DESIGN

Transabdominally obtained amniotic fluid samples from 20 pregnant women with prelabour rupture of the fetal membranes (PROM), showing no signs of clinical infection, and 16 control samples were analysed with universal bacterial PCR. In addition, routine bacterial culture and amniotic fluid glucose were studied.

RESULTS

Out of 20 PROM patients, five were positive in the PCR. PCR detected Ureaplasma urealyticum in two cases, Haemophilus influenzae in one case, Streptococcus oralis in one case and Fusobacterium sp. in one case. Only two of these were positive in a routine bacterial culture. Both were multibacterial infections, which caused discrepancies between the PCR and culture results. Two patients developed infectious complications: both were identified with the PCR assay. Amniotic fluid glucose was lower in PCR positive patients compared with PCR negative patients.

CONCLUSION

Bacterial 16S rDNA PCR, in properly controlled conditions, promises to be a fast and reliable test for early intra-amniotic infection especially concerning Ureaplasma urealyticum.

Intestinal flora in early rheumatoid arthritis

To study the role of intestinal flora in the pathogenesis of RA, we have applied computerized gas-liquid chromatography (GLC) for bacterial cellular fatty acids (CFAs) present in the stool. The CFA spectra represents the total composition of bacterial CFAs in a faecal sample. Correlation and cluster analysis of CFA spectra gathers samples with quantitatively and qualitatively similar bacterial flora into clusters, which then reveal the relationship of samples to each other. Stool samples were collected at the time of hospital admission from patients with early RA before any specific treatment. The CFA spectra in stool samples of RA patients were significantly different from those of non-RA controls. Patients with erosive RA formed a group most clearly different from the controls. Analyses based on the CFA composition of reference bacteria revealed that anaerobic bacteria are primarily responsible for the differences observed. These results suggest that intestinal bacteria play a role in the development of RA.

Yersinia-triggered reactive arthritis. Use of polymerase chain reaction and immunocytochemical staining in the detection of bacterial components from synovial specimens

OBJECTIVE

To investigate whether microbial DNA is present in synovial specimens from patients with Yersinia-triggered reactive arthritis.

METHODS

Synovial specimens from 13 patients with Yersinia enterocolitica O:3-triggered reactive arthritis and from 16 control patients were studied using polymerase chain reaction and immunocytochemical staining techniques.

RESULTS

Yersinia chromosomal DNA was not found in any of the synovial specimens from Yersinia-triggered arthritis patients or controls, whereas with immunocytochemical techniques, Yersinia antigens were observed in synovial specimens from all of the patients with Yersinia-triggered reactive arthritis.

CONCLUSION

Only stable bacterial degradation products, not whole bacteria, are present at the site of inflammation in Yersinia-triggered reactive arthritis.

Social and early-life determinants of overweight and obesity in 18-year-old Swedish men

OBJECTIVES

To investigate the combined effects of size at birth and maternal education on prevalence of overweight and obesity among 18-year-old men.

METHODS

We studied the associations of weight for gestational age and maternal education with body mass index (BMI), overweight and obesity by multivariate linear and logistic regression, adjusted for mother's age, parity and diabetes in a register-based cohort of 6535 men born between 1973 and 1985. Further adjustments for mother's height, pre-pregnancy weight, weight gain and smoking during pregnancy were made in a subsample of 1103 men born between 1982 and 1985.

RESULTS

Mean BMI and prevalence of overweight and obesity decreased with higher maternal education. Mother's BMI and smoking were the strongest predictors of sons' overweight and obesity and essentially accounted for the variation in son's overweight by maternal education. The association of size at birth with later overweight was present only in sons born to mothers who were nonsmokers (odds ratio per 1 standard deviation weight for gestational age z-score 1.46, 95% CI 1.18-1.81) and became substantially reduced on adjustment for mother's pre-pregnancy BMI. Length of gestation was not statistically significantly associated with BMI at age 18.

CONCLUSIONS

Maternal overweight and maternal smoking were the strongest determinants of offspring overweight and its social patterning, and should be a priority for public health policies.

The presence of interleukin-13 in rheumatoid synovium and its antiinflammatory effects on synovial fluid macrophages from patients with rheumatoid arthritis

OBJECTIVE

To study the production of interleukin-13 (IL-13) in rheumatoid synovium and the effects of recombinant IL-13 on the phenotype and function of synovial fluid (SF) macrophages and T cells derived from patients with rheumatoid arthritis (RA).

METHODS

The presence of IL-13 in SF was studied using an IL-13-specific enzyme-linked immunosorbent assay (ELISA); the production of IL-13 was studied in SF mononuclear cells (SFMC) by reverse transcriptase-polymerase chain reaction. The effects of recombinant IL-13 on cytokine production by and phenotype of SFMC were evaluated using cytokine-specific ELISAs and flow cytometry, respectively. The effect of IL-13 on the proliferation of SFMC was determined by 3H-thymidine incorporation. The production and the effects of IL-13 were compared with those of IL-4.

RESULTS

IL-13 was present in 27 of 28 SF samples, and IL-13 messenger RNA (mRNA) was detectable in SFMC. Importantly, IL-13 levels were significantly higher than those of IL-4, and IL-13 protein and mRNA were expressed in several samples, although IL-4 synthesis was undetectable. Recombinant IL-13 significantly reduced the production of IL-1 beta and tumor necrosis factor alpha and the expression of CD16 and CD64 by SF macrophages, whereas the expression of HLA-DR and CD23 was increased. These effects on SF macrophages were similar to those observed with IL-4, but in contrast to IL-4, IL-13 had no growth-promoting effect on SF T cells.

CONCLUSION

IL-13 is consistently present in rheumatoid synovium. The ability of exogenous IL-13 to decrease the production of proinflammatory cytokines by SFMC suggests that it may have therapeutic potential in the treatment of patients with RA.