Biomedical subjects

Stefan Gerber

Publications and source records attributed to Stefan Gerber.

14 recordsLinked to original sources

PubMed2004

ARB: a software environment for sequence data.

The ARB (from Latin arbor, tree) project was initiated almost 10 years ago. The ARB program package comprises a variety of directly interacting software tools for sequence database maintenance and analysis which are controlled by a common graphical user interface. Although it was initially designed for ribosomal RNA data, it can be used for any nucleic and amino acid sequence data as well. A central database contains processed (aligned) primary structure data. Any additional descriptive data can be stored in database fields assigned to the individual sequences or linked via local or worldwide networks. A phylogenetic tree visualized in the main window can be used for data access and visualization. The package comprises additional tools for data import and export, sequence alignment, primary and secondary structure editing, profile and filter calculation, phylogenetic analyses, specific hybridization probe design and evaluation and other components for data analysis. Currently, the package is used by numerous working groups worldwide.

Data Display↗

PubMed2004

Mycoplasma hominis in mid-trimester amniotic fluid: relation to pregnancy outcome.

OBJECTIVE: The relationship between detection of Mycoplasma hominis in mid-trimester amniotic fluid and subsequent pregnancy outcome was investigated. STUDY DESIGN: Amniotic fluids from 456 women of European background who underwent a transabdominal amniocentesis at weeks 15-17 of pregnancy were tested for M. hominis by polymerase chain reaction (PCR). The amplicons were hybridized to an internal probe and detected by ELISA. Pregnancy outcomes and clinical data were subsequently obtained. RESULTS: M. hominis were identified in 29 (6.4%) of the amniotic fluids. The rate of preterm labor in women positive for M. hominis (14.3%) was higher than in the negative women (3.3%) (p=0.01). Similarly, a spontaneous preterm birth with intact membranes occurred in 10.7% of the M. hominis-positive women as opposed to only 1.9% of the negative women (p = 0.02). The presence of this mycoplasma was not correlated with fetal chromosomal aberrations, intrauterine growth restriction or preeclampsia. CONCLUSIONS: Detection of M. hominis in second-trimester amniotic fluids can identify women at increased risk for subsequent preterm labor and delivery.

Adult↗

PubMed2003

Screening for infectious diseases.

INTRODUCTION: Fetal brain injury is an essential cause of lifelong morbidity. Infection appears as a cause of brain damage. Apart from chorioamnionitis, screening for infectious diseases must be considered in pregnancies with a risk of congenital infection or cases with abnormal cerebral ultrasound findings. DISCUSSION: Congenital infections include most of the major components of the TORCH complex: toxoplasmosis, rubella, cytomegalovirus, herpes, and varicella. Seronegative mothers can develop primary infection, which carries a risk of vertical transmission. The timing of the infection is a critical point, because fetal damage often depends on the gestational age at which acute maternal infection took place and occurs more likely in the first half of pregnancy. Antenatal ultrasound can detect brain abnormalities, like hydrocephalus, periventricular leukomalacia, calcifications or hemorrhage. Maternal serologic tests must be performed to look for an infectious etiology; the most frequent agents are the components of the TORCH complex. But additional serology must include parvovirus B19, HIV, and coxsackieviruses.

Brain Injuries↗

PubMed2003

Interleukin-1beta gene polymorphism in women with vulvar vestibulitis syndrome.

OBJECTIVE: The pathogenesis of vulvar vestibulitis syndrome remains unknown but may be related to a localized chronic inflammation. The relation between this syndrome and a polymorphism at position +3953 in the interleukin-1beta gene was examined. Allele 2 of this gene has been associated with increased pro-inflammatory immunity. STUDY DESIGN: Buccal or vestibular swabs from 59 women with strictly defined vulvar vestibulitis and from 48 healthy women were tested by polymerase chain reaction for the presence of two alleles at the +3953 interleukin-1beta locus. RESULTS: Allele 2 of the interleukin-1beta gene was identified in 27 (46%) women with vulvar vestibulitis as opposed to 12 (25%) control women (P=0.03). The interleukin-1beta 1,1 genotype was present in 36 (75%) controls as opposed to 32 (54%) vulvar vestibulitis syndrome patients (P=0.02). All subjects had been previously tested for induced interleukin-1beta production in response to bacterial lipopolysaccharide. In both patients and controls, possession of allele 2 was associated with a small but non-statistically significant increase in induced interleukin-1beta production. CONCLUSION: Allele 2 in the interleukin-1beta gene is more common in women with vulvar vestibulitis syndrome than in other women. Susceptibility to vulvar vestibulitis syndrome might be influenced by carriage of this polymorphism.

Alleles↗

PubMed2003

Detection of Ureaplasma urealyticum in second-trimester amniotic fluid by polymerase chain reaction correlates with subsequent preterm labor and delivery.

Ureaplasma urealyticum is the microorganism most frequently isolated from the amniotic fluid of women in preterm labor. The relationship between intra-amniotic U. urealyticum in healthy second-trimester pregnant women and subsequent pregnancy outcome was investigated. Transabdominal amniotic fluid obtained from 254 asymptomatic women at 15-17 weeks' gestation were tested by polymerase chain reaction (PCR). U. urealyticum was identified in 29 subjects (11.4%). A subsequent preterm labor occurred in 17 U. urealyticum-positive women (58.6%), compared with 10 (4.4%) U. urealyticum-negative women (P<.0001). Preterm birth was documented in 7 (24.1%) U. urealyticum-positive women compared with only 1 U. urealyticum-negative woman (0.4%) (P<.0001). U. urealyticum-positive women also had a higher prevalence of preterm labor in a prior pregnancy (20.7%) than did the negative women (2.7%; P=.0008). PCR testing of second-trimester amniotic fluid for U. urealyticum can identify women at risk for subsequent preterm labor and delivery.

Adult↗

PubMed2003

Polymorphism in intron 2 of the fetal interleukin-1 receptor antagonist genotype influences midtrimester amniotic fluid concentrations of interleukin-1beta and interleukin-1 receptor antagonist and pregnancy outcome.

OBJECTIVE: Preterm labor in experimental models is initiated by intra-amniotic interleukin-1beta (IL-1beta) and inhibited by interleukin-1 receptor antagonist (IL-1ra). The IL-1ra gene is polymorphic and the different alleles are associated with variations in IL-1beta and IL-1ra production. The relationship among the IL-1ra genotype of the fetus, concentrations of IL-1beta and IL-1ra in second-trimester amniotic fluid, and pregnancy outcome was determined. STUDY DESIGN: Amniotic fluids from 291 consecutive women with singleton pregnancies, obtained at 15 to 17 weeks' gestation, were tested for IL-1beta and IL-1ra concentrations by enzyme-linked immunosorbent assay. DNA from fetal cells was analyzed for a length polymorphism in intron 2 of the IL-1ra gene by polymerase chain reaction. Pregnancy outcomes were obtained after completion of testing. RESULTS: The distribution of fetal IL-1ra genotypes was similar to that found in other populations: 50.9% (148) were homozygous for allele 1 (IL1RN*1), 39.5% (115) were IL1RN*1/allele 2 (IL1RN*2) heterozygotes, 6.9% (20) were IL1RN*2 homozygotes, whereas 2.7% (8) had combinations of other alleles. Fetal possession of IL1RN*2 was associated with a greater than 50% increase in midtrimester intra-amniotic IL-1beta levels (P=.006) and a smaller increase in IL-1ra levels (P=.01) compared with fetuses who were IL1RN*1 homozygotes. Despite the low sample size, IL1RN*2 homozygosity, but not midtrimester intraamniotic levels of IL-1beta and IL-1ra, was related to an increased rate of preterm birth (P<.0001). In the 11 pregnancies that were subsequently terminated because of major malformations, there was a decreased frequency of IL1RN*1 homozygosity (P=.04). Birth weight was unrelated to IL-1ra genotype. CONCLUSION: Possession by the fetus of the IL1RN*2 allele is associated with enhanced intraamniotic IL-1beta production. Induction of an intra-amniotic proinflammatory immune response might be more likely to lead to preterm labor in fetuses carrying the IL1RN*2 allele.

Amniotic Fluid↗

PubMed2003

Interleukin-1 receptor antagonist gene polymorphism, vaginal interleukin-1 receptor antagonist concentrations, and vaginal ureaplasma urealyticum colonization in pregnant women.

Ureaplasma urealyticum is the microorganism most frequently isolated from amniotic fluids of women in preterm labor. The relationship between vaginal colonization with U. urealyticum, vaginal interleukin-1 receptor antagonist (IL-1ra) levels, and the IL-1ra genotype in pregnant women was examined. Vaginal specimens, obtained with a cotton swab from 207 women in their first trimester of pregnancy, were tested for IL-1ra concentrations by enzyme-linked immunosorbent assay and for U. urealyticum and IL-1ra genotypes by PCR. U. urealyticum was detected in 85 (41.1%) women. The median IL-1ra level was 450 ng/ml in women positive for U. urealyticum, as opposed to 225 ng/ml in women negative for this microorganism (P < 0.0001). Sixty-two percent of the 16 women who were homozygous for allele 2 of the IL-1ra gene (IL-1RN*2) were colonized with U. urealyticum, as opposed to 47% of the 49 women who were IL-1RN*1/IL-1RN*2 heterozygotes and 34% of the 133 women who were IL-1RN*1 homozygotes (P < 0.05). Median IL-1ra levels were 750 ng/ml in IL-1RN*2 homozygotes, 300 ng/ml in IL-1RN*1/IL-1RN*2 heterozygotes, and 250 ng/ml in IL-1RN*1 homozygotes (P = 0.02). The vast majority of subjects had an uneventful pregnancy and delivered a healthy infant at term. The IL-1ra genotype or U. urealyticum colonization was unrelated to birth weight. Pregnant women who are colonized with U. urealyticum during the first trimester have elevated vaginal IL-1ra concentrations and a higher prevalence of the IL-1RN*2 homozygote genotype than do noncolonized women.

Adolescent↗

PubMed2002

Long-term ex vivo expansion of human fetal liver primitive haematopoietic progenitor cells in stroma-free cultures.

Successful expansion of haematopoietic cells in ex vivo cultures will have important applications in transplantation, gene therapy, immunotherapy and potentially also in the production of non-haematopoietic cell types. Haematopoietic stem cells (HSC), with their capacity to both self-renew and differentiate into all blood lineages, represent the ideal target for expansion protocols. However, human HSC are rare, poorly characterized phenotypically and genotypically, and difficult to test functionally. Defining optimal culture parameters for ex vivo expansion has been a major challenge. We devised a simple and reproducible stroma-free liquid culture system enabling long-term expansion of putative haematopoietic progenitors contained within frozen human fetal liver (FL) crude cell suspensions. Starting from a small number of total nucleated cells, a massive haematopoietic cell expansion, reaching > 1013-fold the input cell number after approximately 300 d of culture, was consistently achieved. Cells with a primitive phenotype were present throughout the culture and also underwent a continuous expansion. Moreover, the capacity for multilineage lymphomyeloid differentiation, as well as the recloning capacity of primitive myeloid progenitors, was maintained in culture. With its better proliferative potential as compared with adult sources, FL represents a promising alternative source of HSC and the culture system described here should be useful for clinical applications.

Antigens, CD34↗

PubMed2002

A deficiency in interferon-alpha production in women with vulvar vestibulitis.

OBJECTIVE: Previous studies have suggested that interferon-alpha may be an effective treatment for some women with vulvar vestibulitis. We evaluated whether women with this syndrome had a deficiency in endogenous and induced interferon-alpha production. STUDY DESIGN: Blood was collected in heparinized tubes from 62 women with vulvar vestibulitis and 47 control women of similar age and ethnicity. Whole blood cultures were incubated in the presence of 0.1 ng/mL lipopolysaccharide (induced) or culture medium (uninduced) for 18 to 20 hours. Aliquots were tested for interferon-alpha levels by enzyme-linked immunosorbent assay. Vestibular samples were tested for human papillomavirus by polymerase chain reaction. Aliquots were also characterized for alleles of the polymorphic gene, interleukin-1 receptor antagonist, by polymerase chain reaction. RESULTS: In uninduced cultures, interferon-gamma was present in 68.1% of control subjects as opposed to 33.9% of vulvar vestibulitis patients ( P =.0005). Similarly, after lipopolysaccharide stimulation, 70.2% of control subjects and only 48.4% of patients produced interferon-alpha ( P =.03). Among the positive samples, however, there were no differences in the interferon-alpha levels between patients and control subjects. In contrast, induction of interferon gamma in response to lipopolysaccharide was similar in control subjects (78.0%) and vulvar vestibulitis patients (82.1%). Women who have a deficiency in interferon-alpha production did not have an increased prevalence of human papillomavirus infection. There was no relation between interleukin-1 receptor antagonist genotype and interferon-alpha production. CONCLUSION: An inability to produce interferon-alpha may contribute to chronic vestibular inflammation in some women.

Female↗

PubMed2002

Defective regulation of the proinflammatory immune response in women with vulvar vestibulitis syndrome.

OBJECTIVE: The cause of vulvar vestibulitis syndrome is unknown. To determine a possible role for defective immune regulation in this chronic condition, proinflammatory and anti-inflammatory immune responses to the 70-kd heat shock protein and to lipopolysaccharide were compared in women with and without vulvar vestibulitis syndrome. STUDY DESIGN: Whole blood cultures from 62 women with vulvar vestibulitis syndrome and 48 control subjects were incubated in the presence or absence of 5 microg/mL human recombinant 70-kd heat shock protein or 0.1 ng/mL lipopolysaccharide for 18 hours. The culture supernatants were then assayed for interleukin-1 beta and interleukin-1 receptor antagonist by enzyme-linked immunosorbent assay. RESULTS: Median levels of interleukin-1 beta were higher in response to heat shock protein in cultures from patients with vulvar vestibulitis syndrome (median, 1.07 ng/mL) as opposed to control subjects (median, 0.40 ng/mL; P =.006). Conversely, levels of interleukin-1 receptor antagonist were higher in response to heat shock protein in control subjects (median, 39.21 ng/mL) than in patients (median, 29.25 ng/mL; P =.009). In response to lipopolysaccharide, median levels of interleukin-1 beta were similar in patients (1.00 ng/mL) and control subjects (1.15 ng/mL); median interleukin-1 receptor antagonist concentrations were higher in control subjects (70.0 ng/mL) than in patients (44.3 ng/mL; P <.0001). The ratio of interleukin-1 receptor antagonist to interleukin-1 beta was higher in control subjects than in women with vulvar vestibulitis syndrome in response to both heat shock protein (P =.0002) and lipopolysaccharide (P =.01). In uninduced cultures, interleukin-1 receptor antagonist levels were also higher in control subjects (median, 1.60 ng/mL) than in patients with vulvar vestibulitis syndrome (median, 0.62 ng/mL; P <.0001). CONCLUSION: A relative inability to down-regulate proinflammatory interleukin-1 beta activity by interleukin-1 receptor antagonist may contribute to the pathophysiologic features of vulvar vestibulitis syndrome.

Cytokines↗

PubMed2002

Polymorphism in the interleukin-1 gene complex and spontaneous preterm delivery.

OBJECTIVE: We examined the association between preterm delivery and polymorphisms at position +3953 of the interleukin-1 beta gene (IL1B+3953) and in intron 2 of the interleukin-1 receptor antagonist gene (IL1RN). STUDY DESIGN: This was a case-control study that involved 52 pregnancies that resulted in spontaneous preterm delivery before 34 weeks of gestation and 197 pregnancies that resulted in birth at term. Polymorphisms were determined by polymerase chain reaction and restriction fragment length polymorphism analysis. RESULTS: Homozygous carriage of IL1B+3953 allele 1 by fetuses of African descent was associated with a risk of preterm delivery (P =.033). Fetuses of Hispanic descent that carried IL1RN allele 2 were found to be at an increased risk for preterm premature rupture of membranes and subsequent preterm delivery(P =.021; odds ratio, 6.5; 95% CI, 1.25-37.7). CONCLUSION: There are associations of spontaneous preterm delivery with the fetal carriage of IL1B+3953*1 and IL1RN*2 alleles in African and Hispanic populations, respectively.

Adult↗

PubMed2002

Differential characterization of women with vulvar vestibulitis syndrome.

OBJECTIVE: We differentiated women with vulvar vestibulitis syndrome into subgroups on the basis of the time of symptom onset, a history of recurrent vulvovaginal candidiasis, and the interleukin-1 receptor antagonist gene polymorphism. STUDY DESIGN: One hundred sixty-two consecutive patients with strictly defined vulvar vestibulitis syndrome were asked to fill out a questionnaire with the assistance of their gynecologist. A buccal sample was collected from each subject for the analysis of interleukin-1 receptor antagonist gene polymorphism; vaginal and vestibular microbial investigations were performed. RESULTS: Symptoms began with the first act of coitus in 20.4% of patients. A history of a recurrent Candida vulvovaginal infection was reported in 42.6% of patients; 25.9% of the patients were positive for the homozygous interleukin-1 receptor antagonist 2,2 genotype. Women with primary vulvar vestibulitis syndrome differed from women with secondary vulvar vestibulitis syndrome; women with primary vulvar vestibulitis syndrome were younger at the time of the onset of the symptoms (23.8 vs 31.2 years, P <.0001) and had never been pregnant (84.8% vs 61.2%, P <.0001). Women with a history of recurrent Candida vulvovaginitis differed from the other subjects by having a higher frequency of constant vestibular pain (40.6% vs 20.4%, P =.005), a vaginal discharge (79.7% vs 45.2%, P <.0001), and dysuria (62.3% vs 29.0%, P =.0001). Women who were homozygous for interleukin-1 receptor antagonist 2,2 genotype had an earlier onset of symptoms (26 years) than did women who were allele 1 homozygotes (31.3 years, P <.05). They also had a shorter duration of symptoms (4.1 vs 5.9 years, P <.05) and a higher frequency of allergy (47.6% vs 23.4%, P =.002). Human papillomavirus in the vaginal vestibule occurred at a greater frequency in women who were homozygous for interleukin-1 receptor antagonist 2,2 genotype. CONCLUSION: Subgroups of women with vulvar vestibulitis syndrome may be differentiated by symptomatic and genetic variables.

Adult↗

PubMed2002

Prenatal diagnosis of congenital cytomegalovirus infection by detection of immunoglobulin M antibodies to the 70-kd heat shock protein in fetal serum.

OBJECTIVE: Antibodies to the 70-kd heat shock protein were evaluated as biomarkers for cytomegalovirus infection. STUDY DESIGN: Fetal sera that was obtained by cordocentesis at 22 to 25 weeks of gestation from 53 mothers with a confirmed primary cytomegalovirus infection and 28 mothers (control group) without cytomegalovirus infection who had been screened for Rh incompatibility, were assayed by enzyme-linked immunosorbent assay for immunoglobulin M and G anti-70-kd heat shock protein antibodies. RESULTS: Eighteen of 53 fetuses (34.0%) from cytomegalovirus-positive mothers were infected, which was determined by culture or polymerase chain reaction. Anti-70-kd heat shock protein immunoglobulin M was detected in 17 of 18 sera (94.4%) from cytomegalovirus-infected fetuses, in 3 of 35 sera (8.6%) from uninfected fetuses, and in 0 of 28 sera from the control group (P <.0001). The level of antibody reactivity was correlated positively with fetal disease. Anti-70-kd heat shock protein immunoglobulin G was detected in sera from 52 of 53 fetuses (98.1%) from cytomegalovirus-infected mothers. CONCLUSION: The anti-70-kd heat shock protein immunoglobulin M assay may be of value in the assessment of fetal cytomegalovirus infection in pregnant women with a primary cytomegalovirus infection.

Cytomegalovirus Infections↗

PubMed2001

Influence of interleukin-1 receptor antagonist gene polymorphism on disease.

Interleukin-1 receptor antagonist (IL-1RA) is a naturally occurring competitive inhibitor of interleukin-1 (IL-1)-induced proinflammatory activity. The IL-1RA gene is polymorphic, resulting in quantitative differences in both IL-1RA and IL-1beta production. Persons homozygous for allele 2 of the IL-1RA gene (IL1RN*2) have a more prolonged and more severe proinflammatory immune response than persons with other IL-1RA genotypes. Thus, being IL1RN*2 homozygous might be beneficial when combating infectious agents or malignantly transformed cells, but it might be detrimental for those with chronic inflammatory conditions or who are pregnant. The IL1RN*2 phenotype is associated with ulcerative colitis and Crohn's disease, lupus erythematosus, vulvar vestibulitis, and possibly with osteoporosis and coronary artery disease. IL1RN*2 homozygosity may also be associated with recurrent spontaneous abortion, preterm birth, and severity of preeclampsia. Conversely, there are negative associations between IL1RN*2 homozygosity and vaginal colonization with mycoplasmas, infection with human cytomegalovirus and Epstein-Barr virus, human immunodeficiency virus proliferation, and the occurrence of ovarian cancer.

Animals↗