Synthesis of a stabilized version of the imidazolone DNA lesion

Imidazolone (dIz) is an abundant, highly mutagenic, and rather unstable DNA lesion that can cause dG-->dC transversion mutations. dIz is generated in DNA by a variety of oxidative processes such as type I photooxidation. Herein we report the synthesis of a carbocyclic nucleoside analogue of dIz and of DNA containing this stabilized lesion analogue. The carbocyclic modification protects this lesion analogue from anomerization. As the repair of the lesion analogue by DNA glycosylases is not possible, this analogue should allow cocrystallization studies together with wild-type repair enzymes. Characterization of the lesion analogue was performed by using spectroscopic methods and enzymatic digestion experiments of the oligonucleotides.

Recent trends in the burden of alcohol intoxication on pediatric in-patient services in Germany

AIMS

To elicit data on alcohol intoxications requiring in-patient treatment in children and adolescents in Germany between 2000 and 2002.

DESIGN AND PARTICIPANTS

An ex-post analysis was performed to assess the number of children and adolescents (age 10-17 years) with acute alcohol intoxications requiring in-patient hospital treatment (> or =24 hours).

SETTING

22 major children hospitals in Germany.

FINDINGS

The number of acute alcohol intoxications requiring in-patient treatment increased from 227 in 2000 to 313 in 2001 (+37.9%; p*<.01) and 350 in 2002 (+10.6%; p*<.05). 10-12 year-old children comprised 2.2%, adolescents aged 13-14 years 28.6%, and adolescents aged 15-17 years 69.2% of the study population. The most significant increase was seen in adolescents aged 13-14 years (2001: +35.9%, and 2002: +19.3%; p*<.05), and 15-17 years (2001: +59.1%, and 2002: +10.1%; p*<.05). The percentage of female patients increased from 34.1% in 2000 to 41.9% in 2001 and 49.8% in 2002 (p*<.05). Mean time spent in the hospital was 1.7 days (range: 1 day-->4 days).

DISCUSSION AND CONCLUSIONS

This is one of the very few studies that provide epidemiological data on the specific issue of alcohol intoxications in children and adolescents that require in-patient treatment. Apparently, gender differences seem to play a minor role in alcohol-related hospital admissions. Our data demonstrate that excessive alcohol consumption remains an issue of concern in this age cohort.

Detection of subclinical systemic disease in primary central nervous system lymphoma (PCNSL) by polymerase chain reaction (PCR) of the rearranged immunoglobulin heavy chain (IgH) genes

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Background: An unresolved question is why some PCNSL spread systemically while most others do not. It was postulated that extracerebral relapse of PCNSL may represent a sequel of initial occult systemic disease rather than true extracerebral spread. Methods: To elucidate this question, we examined bone marrow and peripheral blood specimens of 24 patients with newly diagnosed PCNSL using PCR for the presence of clonally rearranged IgH genes. The applied IgH PCR method was recently developed by a European Concerted Action (BioMed-2). To all samples (50 ng DNA), three different FR primer sets (FR1, FR2 and FR3) were applied in conjunction with a JH consensus primer (JH22). Baseline routine staging procedures showed no evidence of systemic lymphoma manifestations in all patients. Results: The same dominant PCR products were found in bone marrow aspirates, blood samples and tumor biopsy specimens from three patients, indicating the presence of the same tumor cell population in the CNS as well as in extracerebral sites. No concordant dominant amplificates were detectable in the remaining 21 patients. To date, nine patients have relapsed intracerebrally and none systemically after a median follow-up of 25 months. Median overall survival was 30.5 months. Of the three patients with monoclonality outside the CNS, two are still in complete remission 24 and 25 months after diagnosis, respectively. The third patient relapsed intracerebrally 12 months after diagnosis, achieved complete remission after whole-brain irradiation and died in complete remission 16 months after diagnosis due to pulmonary embolism. Conclusions: Extracerebral disease not detectable by routine staging may be present in PCNSL patients. This finding may have an impact on the understanding of PCNSL pathogenesis and the extent of staging and treatment.

No significant financial relationships to disclose.

Adiponectin counteracts cytokine- and fatty acid-induced apoptosis in the pancreatic beta-cell line INS-1

AIMS/HYPOTHESIS

Pancreatic beta-cell apoptosis is a common feature of Type 1 and Type 2 diabetes and leptin exerts an anti-apoptotic function in these cells. The beta-cell line INS-1 was used to test the hypothesis that the adipocyte hormone adiponectin might mediate an anti-apoptotic effect comparable to leptin.

METHODS

Apoptosis was induced by culturing cells with a cytokine combination (interleukin-1beta/interferon-gamma) or palmitic acid in absence or presence of leptin or the globular domain of adiponectin (gAcrp30), respectively.

RESULTS

INS-1 cells had a prominent sensitivity towards cytokine- and fatty acid-induced apoptosis, resulting in about three- and six-fold increases in caspase 3 activation and DNA fragmentation, respectively. gAcrp30 strongly (50-60%) inhibited palmitic acid-induced apoptosis, with a weaker effect against cytokine-induced apoptosis (35%). The same result was observed for leptin with both adipokines being non-additive. Reduction of apoptosis by an inhibitor of IkappaB-kinase (IKK) indicated the involvement of the nuclear factor (NF)-kappaB pathway in both cytokine- and fatty acid-induced apoptosis, however, leptin and gAcrp30 were unable to block NF-kappaB activation. Cytokine- and fatty-acid-induced suppression of glucose/forskolin-stimulated insulin secretion was completely prevented through the action of gAcrp30, whereas leptin was only effective against lipotoxicity-mediated beta-cell dysfunction.

CONCLUSION/INTERPRETATION

Our data show that gAcrp30 partially rescues beta cells from cytokine- and fatty-acid-induced apoptosis and completely restores autoimmune- and lipotoxicity-induced dysfunction of insulin-producing cells. We suggest that gAcrp30 exerts its anti-apoptotic function without modulating NF-kappaB activation. This novel beta cell protective function of gAcrp30 might serve to counteract autoimmune- and lipotoxicity-induced beta-cell destruction.

CNS disease as the main manifestation of hemophagocytic lymphohistiocytosis in two children

Hemophagocytic lymphohistiocytosis is a rare and fatal disorder of early infancy, which affects predominantly the mononuclear phagocyte system and is characterized by the presence of fever, hepatosplenomegaly and cytopenia. Neurological symptoms can be extremely variable, ranging from irritability, and convulsions to focal neurological signs. They often develop during disease progression, but can also be the leading initial symptoms. Early diagnosis is mandatory, because new treatments, including bone marrow transplantation, appear to be promising. Here we present the clinical, neuroradiological and histopathological findings from two children with progressive CNS disease as the main clinical manifestation of hemophagocytic lymphohistiocytosis. Both children died and diagnosis was only obtained in retrospect after careful review of the histopathological material.

Combined endoscopic erbium:YAG laser goniopuncture and cataract surgery

PURPOSE

To study the safety and efficacy of endoscopic erbium:YAG (Er:YAG) laser goniopuncture combined with cataract surgery to treat glaucoma.

SETTING

Department of Ophthalmology, Albert-Ludwigs-University Freiburg, Freiburg, Germany, and Institute of Applied Physics, University of Bern, Bern, Switzerland.

METHODS

In this nonrandominized clinical trial, 20 eyes of 20 patients with cataract and glaucoma were treated by combined phacoemulsification and Er:YAG goniopuncture. The primary study endpoints were intraocular pressure (IOP), visual acuity, and number of antiglaucoma drugs 1 year after surgery. Two- and 3-year postoperative data were also measured. This prospective treatment arm was compared to a retrospective inclusion-matched control group treated by cataract surgery alone.

RESULTS

The mean IOP dropped by 30% (23.5 mm Hg +/- 3.9 [SD] to 16.3 +/- 2.7 mm Hg) after 12 months in the laser-treated group (P<.0001) and by 9% (19.8 +/- 1.3 mm Hg to 18.1 +/- 1.8 mm Hg) in the control group (P =.12). After 3 years, the mean IOP in the laser group was 15.0 +/- 2.0 mm Hg. The mean number of antiglaucoma drugs needed decreased from 1.6 +/- 0.9 to 0.5 +/- 0.8 in the laser group (P<.0001) and from 1.0 +/- 0.9 to 0.8 +/- 0.9 in the control group (P =.21). Anterior chamber hemorrhage occurred in 12 eyes after laser treatment and resolved within 72 hours in all but 1 patient who was on warfarin sodium (Coumadin) therapy. There were no cases of hypotony in either group.

CONCLUSIONS

Endoscopic Er:YAG laser goniopuncture was a successful adjunct to cataract surgery in glaucoma patients. Sustained IOP reduction was achieved with few postoperative complications.

Comparison of long-term fluctuations: laser scanning tomography versus automated perimetry

BACKGROUND

The aim of our study was to investigate the long-term variability of laser scanning tomography and to compare it with the long-term variability of automated perimetry.

METHOD

We retrospectively reviewed the charts of 199 patients (394 eyes) who underwent both automated perimetry (Octopus) and laser scanning tomography (Heidelberg retina tomograph, HRT) in our hospital since 1994. All patients either had ocular hypertension (OHT) or early stage glaucoma. The mean follow-up time was 5.4 years; the average number of examinations was 7.7. The variability was described by the variance ratio VR.

RESULTS

The HRT parameters showed very similar long-term fluctuations as the Octopus parameters. In detail: VR of HRT parameters ranged from 0.04 (cup area, cup volume, mean cup depth) to 0.35 (contour height variation), whereas VR of Octopus parameters ranged from 0.12 (mean sensitivity) to 0.15 (loss variance).

CONCLUSIONS

The long-term variability of HRT parameters is in the same range as the long-term variability of visual field parameters. Since it is now widely accepted that visual field changes over time should be reproduced at least once or twice before clinical consequences can be drawn, the same should be postulated for HRT changes over time.

Endoscopically controlled erbium:YAG goniopuncture versus trabeculectomy: effect on intraocular pressure in combination with cataract surgery

PURPOSE

. To compare the efficacy of endoscopic erbium:YAG laser goniopuncture in glaucoma treatment to trabeculectomy, both methods as adjuncts to cataract surgery.

METHODS

. Fifty-nine eyes of 59 glaucoma patients with coexistent cataract were treated by phacoemulsification and endoscopic Er:YAG goniopuncture in a combined fashion. The primary study endpoints were intraocular pressure (IOP), number of antiglaucomatous drugs, postoperative complications, hospitalisation time and visual acuity at 1 year after surgery. To date, 24 eyes have finished the 1-year follow-up. This prospective treatment arm was compared to a retrospective inclusion-matched control group treated by trabeculectomy and cataract surgery in a single procedure.

RESULTS

. In the laser-treated group, the mean IOP dropped by 30% from 23.4+/-3.7 mmHg to 16.3+/-6 mmHg ( P<0.0001) after 12 months. Without reoperation, treatment was successful in 71% of these eyes. In the control group, the IOP decreased by 33.5% from 22.7+/-3.3 mmHg to 15.1+/-3.8 mmHg ( P<0.0001). The success rate without reoperation was 46%. The number of antiglaucomatous drugs needed decreased from 1.48+/-0.95 to 0.48+/-0.7 ( P<0.0001) in the laser-treated group and from 2.0+/-0.9 to 0.39+/-0.6 ( P<0.0001) in the control group. Postoperative complications were found more frequently in the control group ( P<0.0001). Hospitalisation was shorter in the laser group ( P<0.0001). Postoperative visual acuity was lower in the control group ( P=0.004).

CONCLUSION

. Combined Er:YAG goniopuncture and cataract surgery lowers the IOP to an extent comparable to combined trabeculectomy and cataract surgery. Due to fewer postoperative complications, Er:YAG goniopuncture seems to be superior to standard fistulation surgery as the primary approach within the first year.

10 W widely tunable narrow linewidth double-clad fiber ring laser

A highly efficient and widely tunable narrow linewidth ytterbiumdoped double-clad fiber laser with a linearly polarized output power of 10 W is demonstrated. The laser wavelength was tunable over a range of 24 THz from 1032 nm to 1124 nm by using a diffraction-grating pair in Littrow-Littman configuration in a unidirectional ring-cavity. The laser linewidth was smaller than 2.5 GHz for all power levels and all laser wavelengths. Additionally, an operating mode without any measurable amplified spontaneous emission with a linearly polarized output power of up to 3 W was realized.

Structural basis of pheromone binding to mouse major urinary protein (MUP-I)

The mouse major urinary proteins are pheromone-binding proteins that function as carriers of volatile effectors of mouse physiology and behavior. Crystal structures of recombinant mouse major urinary protein-I (MUP-I) complexed with the synthetic pheromones, 2-sec-butyl-4,5-dihydrothiazole and 6-hydroxy-6-methyl-3-heptanone, have been determined at high resolution. The purification of MUP-I from mouse liver and a high-resolution structure of the natural isolate are also reported. These results show the binding of 6-hydroxy-6-methyl-3-heptanone to MUP-I, unambiguously define ligand orientations for two pheromones within the MUP-I binding site, and suggest how different chemical classes of pheromones can be accommodated within the MUP-I beta-barrel.

BRCA1/2 mutations in Swiss patients with familial or early-onset breast and ovarian cancer

QUESTIONS UNDER STUDY

Germ-line alterations in BRCA1 and BRCA2 genes account for 30-50% of all forms of familial breast and ovarian cancer syndromes. Specific mutations in specific populations and ethnic groups have been identified in BRCA1 and BRCA2. However, it is not known whether such specific mutations prevail in the Swiss population.

METHODS

We started to screen patients with primary breast and ovarian cancer and a strong family history of both cancers by sequencing the full-length coding regions of BRCA1 and BRCA2.

RESULTS

With the selection criteria used in this study we identified 19 mutations in the first 38 patients screened (50%). These mutations were either defined as deleterious and resulted in a protein truncation (n = 10) or were defined as unclassified variants (n = 9). One novel truncating mutation was found in BRCA2 and two novel unclassified variants were detected in BRCA1. These three mutations are not described in the BIC and HGMD databanks.

CONCLUSIONS

We detected three unknown mutations among 38 patients in a Swiss study of BRCA1/2 mutation patterns. One of these novel mutations is clearly deleterious as it leads to protein truncation at nucleotide 133 of BRCA2.

BRCA1/2 mutations in Swiss patients with familial or early-onset breast and ovarian cancer

QUESTIONS UNDER STUDY

Germ-line alterations in BRCA1 and BRCA2 genes account for 30-50% of all forms of familial breast and ovarian cancer syndromes. Specific mutations in specific populations and ethnic groups have been identified in BRCA1 and BRCA2. However, it is not known whether such specific mutations prevail in the Swiss population.

METHODS

We started to screen patients with primary breast and ovarian cancer and a strong family history of both cancers by sequencing the full-length coding regions of BRCA1 and BRCA2.

RESULTS

With the selection criteria used in this study we identified 19 mutations in the first 38 patients screened (50%). These mutations were either defined as deleterious and resulted in a protein truncation (n = 10) or were defined as unclassified variants (n = 9). One novel truncating mutation was found in BRCA2 and two novel unclassified variants were detected in BRCA1. These three mutations are not described in the BIC and HGMD databanks.

CONCLUSIONS

We detected three unknown mutations among 38 patients in a Swiss study of BRCA1/2 mutation patterns. One of these novel mutations is clearly deleterious as it leads to protein truncation at nucleotide 133 of BRCA2.

Potential prognostic value of mitogen-activated protein kinase activity for disease-free survival of primary breast cancer patients

Signaling through pathways involving mitogen-activated protein kinases (MAP kinases) has been implicated in the pathogenesis of cancer. Thus, the activity of MAP kinase is essential in the malignant potential of human breast tumors. p42/44(MAPK) was significantly higher expressed in tumor samples than in matching normal tissues adjacent to the tumor. p42/44(MAPK) protein expression correlated with enhanced MAP kinase activity only in a subset of tumors, indicating that over-expression of MAP kinases does not reflect the activation status of these enzymes. MAP kinase activity was significantly elevated in 131 tissue samples from primary breast tumors when compared to 18 normal tissues adjacent to tumors. A trend for higher MAP kinase activity in primary tumors of node-positive patients was observed when compared with tumors from node-negative patients. Similarly, higher MAP kinase activities were observed in specimens from patients who had a relapse within the follow-up time of 40 months when compared with patients with no relapse. A survival analysis demonstrated that the MAP kinase activity in primary breast tumors is potentially prognostic for relapse-free survival of patients.

Detection of germ-cell tumor cells in the peripheral blood by nested reverse transcription-polymerase chain reaction for alpha-fetoprotein-messenger RNA and beta human chorionic gonadotropin-messenger RNA

By establishing sensitive nested reverse transcription-PCRs for the detection of mRNA of alpha-fetoprotein (AFP) and beta human chorionic gonadotropin (betahCG), we investigated the presence of circulating tumor cells in the peripheral blood of 119 patients with germ-cell tumor. A total of 336 blood samples obtained before and during therapy were examined with regard to clinical applicability. The overall ratio of positive PCR results was 26.5% and was independent of the serum concentration of AFP and hCG/betahCG. No correlation of the positivity for AFP-mRNA to serum AFP level was found. In contrast, positive results in betahCG-PCR were twice as frequent in patients with elevated serum hCG/betahCG levels as in those with normal serum hCG/betahCG levels (P = 0.012). To develop a valid correlation to tumor stage, tumor histology, and serum level of tumor markers, a subgroup of 36 patients was evaluated before definite therapy. The subgroup revealed an overall ratio of 33.3% positive PCR results. The serum level of both of the markers did not correlate with the detection of corresponding mRNA in peripheral blood samples. However, positive betahCG-PCR results were found exclusively in patients with elevated serum hCG/betahCG (6 of 18 versus 0 of 18; P = 0.019). Patients with stage IIC/III germ-cell tumor demonstrated nearly twice the frequency of positive PCR results as patients with stage I tumor [7 (41.2%) of 17 versus 4 (23.5%) of 17] in this subgroup. With regard to histology, positive PCR results were found mostly in embryonal carcinoma.

Antibody spectrum against the viral transactivator protein in patients with human immunodeficiency virus type 1 infection and Kaposi's sarcoma

We analyzed patterns of antibody response to recombinant transactivator protein (human Immunodeficiency virus type 1 [HIV-1] tat) in serum samples from HIV-1-negative subjects (n = 60), HIV-1-infected asymptomatic patients (n = 20), HIV-1-infected patients with Kaposi's sarcoma (n = 25), and patients with Kaposi's sarcoma without HIV-1 infection. None of the healthy subjects possessed anti-tat immunoglobulin G (IgG) in their serum. All asymptomatic patients with HIV-1 infection were anti-tat IgG-positive. Epitope mapping revealed that these sera had anti-tat IgG to all the functional domains of tat protein. Histochemical studies on lymph nodes from five asymptomatic HIV-1-infected patients showed that, in all cases, tat-positive cells were present within the germinal center at the stage of follicular fragmentation containing immunoblasts and small lymphocytes. Of the 25 HIV-1-infected patients with Kaposi's sarcoma, 4 were anti-tat IgG-positive; however, the epitope analysis revealed that IgG to functional domains of tat protein--in particular to transactivating response element (TAR)-binding site--were absent. All patients with Kaposi's sarcoma without HIV-1 infection were anti-tat IgG-negative. Presence or absence of anti-tat IgG and a prevalence of different antibody profiles in different groups of patients indicated the pathophysiologic role of tat protein. Thus, a passive immunization with anti-tat IgG could be a useful strategy to influence the pathophysiologic state of the disease.