[Suicidal gas embolism in hospital]

Luftembolien sind im klinischen Alltag nach traumatischen oder iatrogenen Ereignissen eine häufig zu beobachtende Entität. Fälle einer in suizidaler Absicht herbeigeführten Luftembolie sind selten. Die Konnektivität von luft- und flüssigkeitsführenden Schlauchsystemen ermöglicht die Zufuhr großer Gasmengen in kurzer Zeit mit häufig tödlichem Ausgang. Der Einsatz einer Computertomographie vor der Obduktion ist in solchen Fällen obligat und ermöglicht eine umfassende Darstellung der zugeführten Gasmengen. Wir präsentieren den ungewöhnlichen Fall einer suizidalen venösen Gaszufuhr mittels eines stationären Sauerstoffgerätes in einem Krankenhaus.

Qualitative and Quantitative Analysis of Tryptamines in the Poison of Incilius alvarius (Amphibia: Bufonidae)

Rising numbers of psychoactive tryptamine derivatives have become available on the drug market over the last decade, making these naturally occurring or synthetically manufactured compounds highly relevant for forensic analysis. One of these compounds is 5-methoxy-N,N-dimethyltryptamine (5-MeO-DMT), a constituent of the dried poison of Incilius alvarius (Colorado River toad) which has a history of ritual and/or recreational use. Still, comprehensive and validated qualitative as well as quantitative analytical data on the psychoactive components of this poison are scarce. In this study samples of the poison of Incilius alvarius were collected from live toads in the Sonoran Desert, Arizona (USA) and analyzed with a set of complementary methods. Acetone/water (70/30, v/v) proved to be the solvent of choice for the extraction of tryptamine derivatives. Trace compounds were enriched and overload with 5-MeO-DMT was prevented by chromatographic separation of 5-MeO-DMT prior to qualitative analysis. The method for quantification was validated. Applying attenuated total reflection-Fourier transform infrared spectroscopy to samples of the poison, 5-MeO-DMT was identified as the main tryptamine by comparison to the reference spectrum. The combined evaluation of analytical data gained from gas chromatography-mass spectrometry (GC-MS), liquid chromatography-quadrupole time-of-flight high resolution MS (HPLC-qToF-HRMS), and HPLC-MS/MS confirmed the presence of 5-MeO-DMT, 5-MeO-N-methyltryptamine, 5-MeO-tryptamine, 5-MeO-tryptophol, 2-(5-methoxy-1H-indol-3-yl)-acetic-acid (5-MIAA), 5-HO-N-methyltryptamine, bufotenin, DMT, and tryptophan. For the first time, 5-MeO-tryptamine and two positional isomers of indole-substituted HO-MeO-DMT were detected in the poison of Incilius alvarius. The tryptamine present in the highest concentrations was 5-MeO-DMT (mean ± standard deviation: 410,000 ± 30,000 µg/g). Mean concentrations of 5-MeO-tryptamine (490 ± 260 µg/g), 5-HO-N-methyltryptamine (270 ± 120 µg/g), bufotenin (2,800 ± 1,900 µg/g), and DMT (250 ± 80 µg/g), showed a relatively high variability between individual samples. The comprehensive analytical reference data of Incilius alvarius poison presented here might prove useful for forensic chemists.

New insights into a spectrum of developmental malformations related to mTOR dysregulations: challenges and perspectives

In recent years the role of the mammalian target of rapamycin (mTOR) pathway has emerged as crucial for normal cortical development. Therefore, it is not surprising that aberrant activation of mTOR is associated with developmental malformations and epileptogenesis. A broad spectrum of malformations of cortical development, such as focal cortical dysplasia (FCD) and tuberous sclerosis complex (TSC), have been linked to either germline or somatic mutations in mTOR pathway-related genes, commonly summarised under the umbrella term 'mTORopathies'. However, there are still a number of unanswered questions regarding the involvement of mTOR in the pathophysiology of these abnormalities. Therefore, a monogenetic disease, such as TSC, can be more easily applied as a model to study the mechanisms of epileptogenesis and identify potential new targets of therapy. Developmental neuropathology and genetics demonstrate that FCD IIb and hemimegalencephaly are the same diseases. Constitutive activation of mTOR signalling represents a shared pathogenic mechanism in a group of developmental malformations that have histopathological and clinical features in common, such as epilepsy, autism and other comorbidities. We seek to understand the effect of mTOR dysregulation in a developing cortex with the propensity to generate seizures as well as the aftermath of the surrounding environment, including the white matter.

Diagnose angeborener Störungen der Thrombozytenfunktion

Angeborene Störungen der Thrombozytenfunktion sind eine heterogene Gruppe von Erkrankungen, die oft erst bei Auftreten von Blutungen erkannt werden. Im klinischen Bereich haben sich nur wenige Methoden zur Diagnose und Klassifizierung von angeborenen Thrombozytenfunktionsstörungen bewährt. Für eine rationelle Diagnostik ist ein stufenweises Vorgehen empfehlenswert. Anamnese und klinische Untersuchung sind Grundvoraussetzungen. Das von-Willebrand-Syndrom und andere plasmatische Gerinnungsstörungen sollten vor einer spezifischen Thrombozytenfunktionsdiagnostik immer ausgeschlossen werden. Die Bestimmung von Zahl, Größe, Volumen (MPV) und Morphologie der Thrombozyten erlauben Rückschlüsse auf die zu Grunde liegende Störung.

Die PFA-100®-Verschlusszeit eignet sich als Screening zum Ausschluss schwerer Thrombozytenfunktionsstörungen. Die Aggrego metrie ermöglicht die Untersuchung zahlreicher Aspekte der Thrombozytenfunktion. Die Durchflusszytometrie ist zur Diagnose von Thrombasthenie Glanzmann, Bernard-Soulier- Syndrom und Freisetzungsstörungen geeignet. Molekulargenetische Untersuchungen können die Verdachtsdiagnose bestätigen oder zum Nachweis nicht beschriebener Defekte verwendet werden. Hier wird die ungekürzte Version der inter -disziplinären Leitlinie* präsentiert.

Dysregulation of the (immuno)proteasome pathway in malformations of cortical development

Background

The proteasome is a multisubunit enzyme complex involved in protein degradation, which is essential for many cellular processes. During inflammation, the constitutive subunits are replaced by their inducible counterparts, resulting in the formation of the immunoproteasome.

Methods

We investigated the expression pattern of constitutive (β1, β5) and immunoproteasome (β1i, β5i) subunits using immunohistochemistry in malformations of cortical development (MCD; focal cortical dysplasia (FCD) IIa and b, cortical tubers from patients with tuberous sclerosis complex (TSC), and mild MCD (mMCD)). Glial cells in culture were used to elucidate the mechanisms regulating immunoproteasome subunit expression.

Results

Increased expression was observed in both FCD II and TSC; β1, β1i, β5, and β5i were detected (within cytosol and nucleus) in dysmorphic neurons, balloon/giant cells, and reactive astrocytes. Glial and neuronal nuclear expression positively correlated with seizure frequency. Positive correlation was also observed between the glial expression of constitutive and immunoproteasome subunits and IL-1β. Accordingly, the proteasome subunit expression was modulated by IL-1β in human astrocytes in vitro. Expression of both constitutive and immunoproteasome subunits in FCD II-derived astroglial cultures was negatively regulated by treatment with the immunomodulatory drug rapamycin (inhibitor of the mammalian target of rapamycin (mTOR) pathway, which is activated in both TSC and FCD II).

Conclusions

These observations support the dysregulation of the proteasome system in both FCD and TSC and provide new insights on the mechanism of regulation the (immuno)proteasome in astrocytes and the molecular links between inflammation, mTOR activation, and epilepsy.

Electronic supplementary material

The online version of this article (doi:10.1186/s12974-016-0662-z) contains supplementary material, which is available to authorized users.

Promoter-Specific Hypomethylation Correlates with IL-1β Overexpression in Tuberous Sclerosis Complex (TSC)

In tuberous sclerosis complex (TSC), overexpression of numerous genes associated with inflammation has been observed. Among different proinflammatory cytokines, interleukin-1β (IL-1β) has been shown to be significantly involved in epileptogenesis and maintenance of seizures. Recent evidence indicates that IL-1β gene expression can be regulated by DNA methylation of its promoter. In the present study, we hypothesized that hypomethylation in the promoter region of the IL-1β gene may underlie its overexpression observed in TSC brain tissue. Bisulfite sequencing was used to study the methylation status of the promoter region of the IL-1β gene in TSC and control samples. We identified hypomethylation in the promoter region of the IL-1β gene in TSC samples. IL-1β is overexpressed in tubers, and gene expression is correlated with promoter hypomethylation at CpG and non-CpG sites. Our results provide the first evidence of epigenetic modulation of the IL-1β signaling in TSC. Thus, strategies that target epigenetic alterations could offer new therapeutic avenues to control the persistent activation of interleukin-1β-mediated inflammatory signaling in TSC brain.

Expression of microRNAs miR21, miR146a, and miR155 in tuberous sclerosis complex cortical tubers and their regulation in human astrocytes and SEGA-derived cell cultures

Tuberous sclerosis complex (TSC) is a genetic disease presenting with multiple neurological symptoms including epilepsy, mental retardation, and autism. Abnormal activation of various inflammatory pathways has been observed in astrocytes in brain lesions associated with TSC. Increasing evidence supports the involvement of microRNAs in the regulation of astrocyte-mediated inflammatory response. To study the role of inflammation-related microRNAs in TSC, we employed real-time PCR and in situ hybridization to characterize the expression of miR21, miR146a, and miR155 in TSC lesions (cortical tubers and subependymal giant cell astrocytomas, SEGAs). We observed an increased expression of miR21, miR146a, and miR155 in TSC tubers compared with control and perituberal brain tissue. Expression was localized in dysmorphic neurons, giant cells, and reactive astrocytes and positively correlated with IL-1β expression. In addition, cultured human astrocytes and SEGA-derived cell cultures were used to study the regulation of the expression of these miRNAs in response to the proinflammatory cytokine IL-1β and to evaluate the effects of overexpression or knockdown of miR21, miR146a, and miR155 on inflammatory signaling. IL-1β stimulation of cultured glial cells strongly induced intracellular miR21, miR146a, and miR155 expression, as well as miR146a extracellular release. IL-1β signaling was differentially modulated by overexpression of miR155 or miR146a, which resulted in pro- or anti-inflammatory effects, respectively. This study provides supportive evidence that inflammation-related microRNAs play a role in TSC. In particular, miR146a and miR155 appear to be key players in the regulation of astrocyte-mediated inflammatory response, with miR146a as most interesting anti-inflammatory therapeutic candidate.

Clinical significance of MUC1, MUC2 and CK17 expression patterns for diagnosis of pancreatobiliary arcinoma

Pancreatic cancer is characterized by aggressive growth and resistance to treatment. Identification of unique biomarkers for diagnosis and prognosis is important for treatment of this disease. We investigated the expression patterns of mucin 1 (MUC1), mucin 2 (MUC2) and cytokeratin 17 (CK17) in both normal tissues and metastatic adenocarcinomas using immunohistochemistry (IHC). We have shown that MUC1 (pan-epithelial membrane mucin), MUC2 (intestinal-type secretory mucin) and CK17 can be used as a panel of markers to distinguish collectively pancreatobiliary carcinoma from other primary site carcinomas. Tumors originating in the pancreatobiliary system showed an expression pattern of MUC1 (+), MUC2 (-) and CK17 (+). By contrast, tumors arising from the colorectal region were MUC1 (-), MUC2 (+) and CK17 (-), while tumors originating from non-pancreatobiliary system tissue expressed a MUC1 (+), MUC2 (-) and CK17 (-) profile. More importantly, the MUC1 (+), MUC2 (-) and CK17 (+) result showed greater sensitivity than CA19-9 by IHC, which is the currently accepted and widely used pancreatic tumor marker for diagnosing pancreatic cancer. Thirteen of 51 cases (25%) of pancreatobiliary adenocarcinomas with the pattern MUC1 (+), MUC2 (-) and CK17 (+) showed no immunoreactivity for CA19-9, while 34/51 (67%) cases having MUC1 (+), MUC2 (-) and CK17 (+) were correlated with positive CA19-9 staining. Our data support using an antibody panel of MUC1, MUC2 and CK17 to enhance current methods for pancreatic cancer diagnosis by identifying specifically the primary tissue of origin.

Differences in SMN1 allele frequencies among ethnic groups within North America

Background:

Spinal muscular atrophy (SMA) is the most common inherited lethal disease of children. Various genetic deletions involving the bi-allelic loss of SMN1 exon 7 are reported to account for 94% of affected individuals. Published literature places the carrier frequency for SMN1 mutations between 1 in 25 and 1 in 50 in the general population. Although SMA is considered to be a pan-ethnic disease, carrier frequencies for many ethnicities, including most ethnic groups in North America, are unknown.

Objectives and methods:

To provide an accurate assessment of SMN1 mutation carrier frequencies in African American, Ashkenazi Jewish, Asian, Caucasian, and Hispanic populations, more than 1000 specimens in each ethnic group were tested using a clinically validated, quantitative real-time polymerase chain reaction (PCR) assay that measures exon 7 copy number.

Results:

The observed one-copy genotype frequency was 1 in 37 (2.7%) in Caucasian, 1 in 46 (2.2%) in Ashkenazi Jew, 1 in 56 (1.8%) in Asian, 1 in 91 (1.1%) in African American, and 1 in 125 (0.8%) in Hispanic specimens. Additionally, an unusually high frequency of alleles with multiple copies of SMN1 was identified in the African American group (27% compared to 3.3–8.1%). This latter finding has clinical implications for providing accurate adjusted genetic risk assessments to the African American population.

Conclusions:

Differences in the frequency of SMA carriers were significant among several ethnic groups. This study provides an accurate assessment of allele frequencies and estimates of adjusted genetic risk that were previously unavailable to clinicians and patients considering testing.

CCN3 is a novel endogenous PDGF-regulated inhibitor of glomerular cell proliferation

CCN proteins affect cell proliferation, migration, attachment, and differentiation. We identified CCN3 as a suppressed gene following platelet-derived growth factor (PDGF)-BB or -DD stimulation in a cDNA-array analysis of mesangial cells. In vitro growth-arrested mesangial cells overexpressed and secreted CCN3, whereas the addition of the recombinant protein inhibited cell growth. Induction of mesangial cell proliferation by PDGF-BB or the specific PDGF beta-receptor ligand PDGF-DD led to downregulation of CCN3 mRNA, confirming the array study. Specific PDGF alpha-receptor ligands had no effect. CCN3 protein was found in arterial smooth muscle cells, the medullary interstitium, and occasional podocytes in the healthy rat kidney. Glomerular CCN3 was low prior to mesangial proliferation but increased as glomerular cell proliferation subsided during mesangioproliferative glomerulonephritis (GN). Inhibition of PDGF-B in mesangioproliferative disease led to overexpression of glomerular CCN3 mRNA. CCN3 localized mostly to podocytes in human glomeruli, but this expression varied widely in different human glomerulonephritides. Glomerular cell proliferation negatively correlated with CCN3 expression in necrotizing GN. Our study identifies CCN3 as an endogenous inhibitor of mesangial cell growth and a modulator of PDGF-induced mitogenesis.

Quantitative multiplex PCR analysis for large rearrangements in the MLH1 and MSH2 genes for hereditary non- polyposis colorectal cancer

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Background: Hereditary non-polyposis colon cancer (HNPCC) is caused by germline mutations in the mismatch repair genes MLH1, MSH2, MSH6 and PMS2. HNPCC patients have ∼80% increased risk of colon cancer, and elevated risk for cancers of the endometrium, ovary, stomach, small intestine and upper urinary tract. Molecular genetic testing in HNPCC families showed that ∼90% of cases are due to MLH1 and MSH2, 7–10% to MSH6, and <5% to PMS2. The majority are point mutations detectable by sequencing; however, about 5% and 20% of mutations in MLH1 and MSH2, respectively, are large rearrangements that require other detection techniques such as Southern blot or multiplex ligation-dependent probe amplification (MLPA). Our laboratory had previously developed and implemented a quantitative multiplex PCR (QMPCR) endpoint assay for clinical testing for large rearrangements in the BRCA1 and BRCA2 genes. We have developed a similar assay for the MLH1 and MSH2 genes in HNPCC which we refer to as CART (Colorectal cancer Rearrangement Test). Methods: CART consists of 9 multiplexes of 8–12 amplicons each, with at least 2 amplicons targeting each coding exon, promoter, and 3’UTR of both genes. Copy numbers are normalized against MLH1, MSH2, and two unlinked control genes. Internally developed software provides automated analysis and statistical confidence levels for the presence or absence of large rearrangements. Results: Initial validation of CART has been performed on 14 MLH1 or MSH2 rearrangement-positive and 30 negative DNA samples. Results were 100% concordant with previous Southern blot data, as well as supplemental MLPA studies. CART has greatly improved turnaround time, accuracy, and consistency compared to Southerns and MLPA. Conclusions: QMPCR is a superior diagnostic tool for detecting large rearrangements in disease genes. Validation of CART for MLH1 and MSH2 rearrangements is underway on a larger set of previously genotyped samples in a blinded manner. In conjunction with sequencing of the MLH1 and MSH2 genes, the CART assay is expected to improve molecular diagnostic testing on individuals at risk for HNPCC.

No significant financial relationships to disclose.

Comprehensive statistical study of 452 BRCA1 missense substitutions with classification of eight recurrent substitutions as neutral

BACKGROUND

Genetic testing for hereditary cancer syndromes contributes to the medical management of patients who may be at increased risk of one or more cancers. BRCA1 and BRCA2 testing for hereditary breast and ovarian cancer is one such widely used test. However, clinical testing methods with high sensitivity for deleterious mutations in these genes also detect many unclassified variants, primarily missense substitutions.

METHODS

We developed an extension of the Grantham difference, called A-GVGD, to score missense substitutions against the range of variation present at their position in a multiple sequence alignment. Combining two methods, co-occurrence of unclassified variants with clearly deleterious mutations and A-GVGD, we analysed most of the missense substitutions observed in BRCA1.

RESULTS

A-GVGD was able to resolve known neutral and deleterious missense substitutions into distinct sets. Additionally, eight previously unclassified BRCA1 missense substitutions observed in trans with one or more deleterious mutations, and within the cross-species range of variation observed at their position in the protein, are now classified as neutral.

DISCUSSION

The methods combined here can classify as neutral about 50% of missense substitutions that have been observed with two or more clearly deleterious mutations. Furthermore, odds ratios estimated for sets of substitutions grouped by A-GVGD scores are consistent with the hypothesis that most unclassified substitutions that are within the cross-species range of variation at their position in BRCA1 are also neutral. For most of these, clinical reclassification will require integrated application of other methods such as pooled family histories, segregation analysis, or validated functional assay.

Application of haplotype pair analysis for the identification of hemizygous loci

An expectation maximisation based prediction algorithm was created to identify unusual haplotypes in patient samples that may be caused by small intragenic deletions. In this approach, unphased SNP genotypes are compared to pairs of canonical haplotypes to identify potentially hemizygous regions. This method was successfully applied to identify five deletions in the 3' region of BRCA1.

IGF-I, osteocalcin, and bone change in pregnant normotensive and pre-eclamptic women

Pre-eclampsia is a pregnancy disorder of uncertain etiology that affects 5-10% of all pregnancies, with symptoms typically presenting around or after 20 wk gestation. We hypothesized that IGF-I, osteocalcin, and bone loss would be different among women with pre-eclampsia compared with normotensive pregnant women. There were 962 pregnant healthy women, aged 12-35, who were assessed at entry to care, at 28 wk, and at delivery for osteocalcin and IGF-I concentrations. Bone ultrasound was measured at entry to care and at 6 wk postpartum, whereas bone mineral density was measured by dual x-ray densitometry at delivery. There were 64 women (6.7%) among the women being followed who developed pre-eclampsia. In women with pre-eclampsia, IGF-I concentrations were 74% greater in the third trimester compared with the first trimester, whereas there was little change in osteocalcin concentrations. In contrast, normotensive women had an average increase of 43% in IGF-I concentrations accompanied by a 63% decline in osteocalcin concentrations. In women with pre-eclampsia, IGF-I and osteocalcin concentrations were significantly correlated (r = 0.48 and 0.43) at both the first and third trimester time points, but only in the third trimester among normotensive women (r = 0.27). The bone change difference between the two groups was not statistically significant. Women with pre-eclampsia appear to have an exaggerated IGF-I responsiveness compared with women who are normotensive; however, the strong correlation between IGF-I and osteocalcin in women with pre-eclampsia suggests that the IGF-I is able to retain its role as a local regulator of bone remodeling, as indicated by the osteocalcin concentrations.

The BRCA2 genetic variant IVS7 + 2T-->G is a mutation

Biochemical and genetic characterizations that support the conclusion that the variant BRCA2 IVS7 + 2T --> G represents a deleterious mutation are presented. RNA analysis from a breast cancer patient with BRCA2 IVS7 + 2T --> G showed that the productive message was produced from only one chromosome. A haplotype analysis confirmed that the intronic variant resides on the chromosome that does not produce the normal mRNA. Additionally, an RNA splicing product that deletes exon 7 was produced by the chromosome that carries BRCA2 IVS7 + 2T --> G. The deletion of exon 7 from the RNA alters the open reading frame by removing residues 249-287 and incorporating 18 abnormal amino acids before terminating with an opal stop codon. The experimental approach presented produces strong evidence of the presence of a deleterious mutation, because the contribution by both chromosomes to each RNA species analyzed was tracked using a coding region polymorphism as a marker. Furthermore, a single nucleotide polymorphism (SNP) haplotype analysis that confirms the location of the intronic variant and an associated family history that shows a high incidence of cancer supported these biochemical data.

Bone loss in adolescent and adult pregnant women

OBJECTIVE

To determine the amount of change in bone ultrasound measures among pregnant adolescent girls and women and whether that change was associated with adolescence, maternal growth during pregnancy, limited weight gain during pregnancy, hypertension in pregnancy, or poor diet.

METHODS

We used bone ultrasound measurements of attenuation and sound velocity to assess changes in quantitative ultrasound indices of 252 pregnant adolescent girls and women age 12-34 years. Bone ultrasound measurement of the os calcis was performed at 16 +/- 7 weeks' gestation (mean +/- standard deviation and 6 +/- 1 weeks postpartum.

RESULTS

On average, the bone quantitative ultrasound index was 3.6% lower 6 weeks postpartum than at entry into care (P <.001). Nulliparous patients had significantly greater bone loss than did parous subjects. Still-growing adolescents had greater quantitative ultrasound index decreases than did grown women (-5.5% versus -1.9%, P <.02). Patients in the upper tertile of baseline quantitative ultrasound index lost more bone than did patients in the lower tertile (-5% versus 0.5%, P <.02). Pregravid weight, weight change during pregnancy, gynecologic age, and age at menarche predicted bone change in subgroups defined by parity or age; however, none of the differences in those variables were statistically significant. Greater dietary calcium intake, less physical activity, and pregnancy hypertension and preeclampsia were not associated with bone change.

CONCLUSION

There has been inconsistent evidence of maternal bone loss during pregnancy. The findings of this study challenge the assumption that because of increased calcium absorption from the maternal intestine, no transitory bone loss occurs in pregnancy. The amount of bone loss among growing adolescents and nulliparous patients was consistent with the demands of fetal mineralization and the continued demands of the maternal skeleton during growth.

A characterization of genetic variants in BRCA1 intron 8 identifies a mutation and a polymorphism

The biochemical and genetic characterizations of two variants that occur in BRCA1 intron 8 are presented. The variant IVS8+2T-->C induces an aberrant transcript that deletes exon 8. This exon-skipping deletion disrupts the open reading frame by juxtaposing exon 7 and exon 9 in the aberrant splice product. Theoretically, 50 abnormal residues from reading frame 2 are translated following exon 7 before a stop codon is encountered. The chromosomal contribution to the relevant RNA species was tracked using a silent polymorphism at codon 694 (serine AGC or AGT). Nucleotide sequencing of this polymorphic codon demonstrated that the aberrant transcript was derived solely from the chromosome encoding AGT. The normally spliced productive transcript also displayed loss of heterozygosity and was derived solely from the chromosome encoding AGC at codon 694. Also, a haplotype analysis using a breast cancer patient database showed that the chromosome bearing serine 694-AGT carried IVS8+2T-->C. A second more common variant, IVS8-58delT, was characterized as a polymorphism. Analysis of RNA from patient samples used the same silent polymorphism at codon 694 and showed that the normal message was derived from both chromosomes.

BRCA1 IVS16+6T-->C is a deleterious mutation that creates an aberrant transcript by activating a cryptic splice donor site

Results and conclusions are presented that characterize BRCA1 IVS16+6T-->C as a deleterious mutation. BRCA1 transcripts from peripheral blood mononuclear cells of a breast cancer patient with the transition IVS16+6T-->C show the loss of a heterozygous base within codon 871. Additionally, an aberrant RNA splicing product which incorporates 69 bases of the 5' end of intron 16 at the junction of exons 16 and 17 is produced solely from the allele with IVS16+6T-->C. This insertion contains two in-frame stop codons and encodes a protein truncated at residue 1662 (plus 13 residues encoded by the intron). The aberrant transcript is specifically associated with the intronic variant since it was contained within the insertion. Furthermore, sequence analysis of the heterozygous base within codon 871 demonstrates that the two RNA products, productive mRNA and aberrantly spliced RNA, are contributed to exclusively by separate alleles. Finally, the aberrant transcript is produced by the activation of a cryptic splice site which has greater homology with the primate consensus splice sequence than the mutated exon 16 donor site.

The reproducibility of ultrasound bone measures in a triethnic population of pregnant adolescents and adult women

We used bone ultrasound technology with its measurement of attenuation (broadband ultrasound attenuation [BUA] as dB/MHz) and sound velocity (speed of sound as m/s) for assessing the quantitative ultrasound index (QUI) summary measure in a triethnic population of 280 pregnant women. The study purpose was to describe the reproducibility of the ultrasound technology and determine if the correlations of age, weight, and ethnicity with the bone status measures in this population are consistent with the correlations of age, weight, and ethnicity that have been reported with other technologies that measure bone mass. We evaluated the first 280 women enrolled in our longitudinal study of lead turnover from maternal bone during pregnancy and lactation. Enrollees were pregnant, aged 12-29 years, and self-classified as black, white, or Hispanic. Bone ultrasound was measured twice at entry to prenatal care, which, on average, was at 14 weeks gestation. Reproducibility was described with intraclass correlations and the standard error of measurement. Age, weight, and ethnicity were associated with bone status measures using Spearman correlations and generalized linear models. The reproducibility of the summary bone measure, QUI, was high (96-97%). Variation in age and ethnicity did not alter reproducibility; however, the reproducibility of the attenuation measure (BUA as dB/MHz) lessened with increasing weight, declining from 95% to 89%. Since this attenuation is included in the summary QUI measure, there was a slight, and nonsignificant, decline in QUI reproducibility (from 97% to 96%) as women increased in size. There were no statistically significant differences in mean bone ultrasound measures according to age, where ages ranged from 12-29 years. Women who categorized themselves as black had, on average, an 8.5% greater QUI than did women who classified themselves as Hispanic or white. There were no significant pair-wise differences in mean ultrasound measures of bone between women classifying themselves as Hispanic or white. The use of ultrasound is a highly reproducible measure to assess bone characteristics in a population of pregnant adolescent and young adult women and its summary measure of bone mass is correlated with ethnic as well as body size characteristics.

Effect of cimetidine on the pharmacokinetics of the metabolites of metamizol

Metamizol (dipyrone) is hydrolyzed in the gastrointestinal tract to the pharmacologically active metabolite 4-methyl-amino-antipyrine (4-MAA), which is transformed by both, oxidation to 4-formyl-amino-antipyrine (4-FAA) and demethylation to 4-amino-antipyrine (4-AA). 4-AA is acetylated to 4-acetyl-amino-antipyrine (4-AcAA). The aim of the present study was to investigate whether cimetidine will alter the pharmacokinetics of the metabolites of metamizol due to cimetidine-induced inhibition of the metabolic transformation of 4-MAA. The study was carried out in 12 patients with duodenal ulcer treated with cimetidine 1,000 mg daily over 20 days. A single oral dose of metamizol 1,500 mg was administered 2 days prior to commencement of cimetidine therapy to all patients. Two further doses of 750 and 1,500 mg of metamizol were given in a randomized order on days 8 and 13 during cimetidine treatment. Blood samples for determination of metamizol metabolites were drown over 48 hours post dose. Drug assays for metamizol metabolites and cimetidine were performed using HPLC methods. The patients were phenotyped for CYP2D6 and acetylation polymorphism. The results revealed that cimetidine interacted with 4-MAA by increasing the systemic availability, prolonging the elimination half-life and decreasing the systemic clearance of 4-MAA, whereas the renal clearances of 4-MAA remained unchanged. Consistent with cimetidine-induced changes in the oxidation of 4-MAA to 4-FAA, as well as in the demethylation of 4-MAA to 4-AA, were the decreased rates of production and the lower maximum concentrations of 4-FAA and 4-AA when metamizol was administered during cimetidine treatment (p < 0.05). No correlation was found between the decrease in the production rates of 4-FAA induced by cimetidine and the hydroxylation abilities of the patients, this suggesting that CYP2D6 is not involved in the metabolism of 4-MAA to 4-FAA. The acetylation of 4-AA to 4-AcAA was not affected by cimetidine. Cimetidine produced an increase not proportional to the dose in the systemic availability only of 4-MAA, whereas the kinetics of the other metabolites changed proportionally to the increasing dose of metamizol.

Specific complex formation between the type II bare lymphocyte syndrome-associated transactivators CIITA and RFX5

Two of the genes defective in the five complementation groups identified in the class II-negative bare lymphocyte syndrome or corresponding laboratory mutants have been cloned. One gene encodes a protein, RFX5, that is a member of the RFX family of DNA binding proteins. The other, CIITA, encodes a large protein with a defined acidic transcriptional activation domain; this protein does not interact with DNA. Expression plasmids encoding regions of RFX5 fused to the GAL4 DNA binding domain activated transcription from a reporter construct containing GAL4 sites in a cotransfection assay in the Raji human B cell line. However, these plasmids produced transcriptional activity in HeLa cells only in conjunction with interferon gamma stimulation, a condition in which expression of both CIITA and class II major histocompatibility complex surface proteins are induced. Furthermore, these plasmids were not active in RJ2.2.5, an in vitro mutagenized derivative of Raji in which both copies of CIITA are defective. Transcriptional activation by the RFX5 fusion protein could be restored in RJ2.2.5 by cotransfection with a CIITA expression plasmid. Finally, a direct interaction between RFX5 and CIITA was detected with the yeast two-hybrid and far-Western blot assays. Thus, RFX5 can activate transcription only in cooperation with CIITA. RFX5 and CIITA associate to form a complex capable of activating transcription from class II major histocompatibility complex promoters. In this complex, promoter specificity is determined by the DNA binding domain of RFX5 and the general transcription apparatus is recruited by the acidic activation domain of CIITA.

Transactivation by CIITA, the type II bare lymphocyte syndrome-associated factor, requires participation of multiple regions of the TATA box binding protein

CIITA is a positive regulator of class II major histocompatibility complex gene transcription that has been found to be defective in one of the five complementation groups of class II major histocompatibility complex-negative cell lines. Its N-terminal region is capable of activating transcription from a reporter gene when fused to a DNA binding domain. We have investigated the mechanism of transactivation mediated by the CIITA activation domain by studying its role in the process of transcription initiation and elongation. Specifically the altered specificity TBP (TATA box binding protein) assay has been used to analyze the response of the CIITA activation domain to mutations in TBP known to disrupt its interaction with its associated general factors. Transactivation by CIITA was extremely sensitive to a mutation in TBP that in yeast is known to abolish VP16-mediated transcription but leaves basal transcription unaffected. A TBP mutant defective in interaction with TBP-associated factor TAFII250 also failed to mediate transactivation through the CIITA activation domain. Certain interactions between TBP and general factors that are specifically required for acidic activation domains were also required for CIITA-mediated transactivation to reach its full potential. Finally, like VP16, CIITA was able to stimulate elongation of transcription. Overall the mechanism of transactivation by the human B-cell-specific CIITA is very similar to that mediated by the herpes virus transactivator VP16 in the ways that have been tested.

A zinc finger protein that represses transcription of the human MHC class II gene, DPA

The proximal promoters of all MHC class II genes contain a sequence element, the 19-bp X box, that is conserved in both sequence and position. Extensive analysis using a wide variety of approaches has demonstrated that the integrity of the X box is essential for transcription initiation from all class II genes studied. However, the X box is now recognized to contain two subregions, termed X1 and X2. Radiolabeled oligonucleotides corresponding to the X2 box of the MHC class II genes DPA and DQB were used to screen B cell and T cell expression libraries. A novel cDNA, termed XBR (X box repressor), encoding a putative zinc finger protein that binds specifically to the DPA X2 box was isolated from a human T cell line. The XBR gene encodes a 7-kb message that is ubiquitously transcribed, although at higher levels in tissues of the lymphocytic compartment. Southern blots indicate that this gene is single copy in primates and contains regions that are highly divergent in other species. Overexpression of XBR in a B cell line resulted in a dramatic reduction of transcription from a reporter gene construct driven by the DPA promoter, but not from similar constructs with mutations in the X2 box. Similarly, overexpression of XBR reduced induction of reporter gene activity driven from the DPA promoter in HeLa cells treated with IFN-gamma. XBR may, therefore, mediate transcriptional repression, thus preventing inappropriate MHC class II expression. XBR function may in part explain the dominant trans-acting repression of MHC class II expression reported in cell fusion experiments.

A zinc finger protein that represses transcription of the human MHC class II gene, DPA

The proximal promoters of all MHC class II genes contain a sequence element, the 19-bp X box, that is conserved in both sequence and position. Extensive analysis using a wide variety of approaches has demonstrated that the integrity of the X box is essential for transcription initiation from all class II genes studied. However, the X box is now recognized to contain two subregions, termed X1 and X2. Radiolabeled oligonucleotides corresponding to the X2 box of the MHC class II genes DPA and DQB were used to screen B cell and T cell expression libraries. A novel cDNA, termed XBR (X box repressor), encoding a putative zinc finger protein that binds specifically to the DPA X2 box was isolated from a human T cell line. The XBR gene encodes a 7-kb message that is ubiquitously transcribed, although at higher levels in tissues of the lymphocytic compartment. Southern blots indicate that this gene is single copy in primates and contains regions that are highly divergent in other species. Overexpression of XBR in a B cell line resulted in a dramatic reduction of transcription from a reporter gene construct driven by the DPA promoter, but not from similar constructs with mutations in the X2 box. Similarly, overexpression of XBR reduced induction of reporter gene activity driven from the DPA promoter in HeLa cells treated with IFN-gamma. XBR may, therefore, mediate transcriptional repression, thus preventing inappropriate MHC class II expression. XBR function may in part explain the dominant trans-acting repression of MHC class II expression reported in cell fusion experiments.

Cooperativity between the J and S elements of class II major histocompatibility complex genes as enhancers in normal and class II-negative patient and mutant B cell lines

The class II major histocompatibility complex genes all contain in their proximal promoters three cis-elements called S, X, and Y that are conserved in both sequence and position, and a fourth element, J, conserved in sequence but not in position. J, X, and Y and, to some extent, S, have been shown to be functionally important in regulation of expression of these genes. In the present study, a protein factor that binds cooperatively to the S plus J elements of the promoter of the class II major histocompatibility complex gene DPA has been detected. Moreover, functional cooperativity between S and J in activation of the enhancerless -40 interferon-beta (-40 IFN-beta) promoter has been demonstrated. Finally, the latter assay appears to subdivide complementation group A of class II negative human B cell lines that includes both mutants generated in vitro and cells from patients with the bare lymphocyte syndrome (type II). In three of these cell lines, the enhancerless -40 IFN-beta promoter containing the S plus J elements was functionally active, while in the others it was inactive.

A factor that regulates the class II major histocompatibility complex gene DPA is a member of a subfamily of zinc finger proteins that includes a Drosophila developmental control protein

A novel DNA sequence element termed the J element involved in the regulated expression of class II major histocompatibility complex genes was recently described. To study this element and its role in class II gene regulation further, a cDNA library was screened with oligonucleotide probes containing both the S element and the nearby J element of the human DPA gene. Several DNA clones were obtained by this procedure, one of which, clone 18, is reported and characterized here. It encodes a protein predicted to contain 688 amino acid residues, including 11 zinc finger motifs of the C2H2 type in the C-terminal region, that are Krüppel-like in the conservation of the H/C link sequence connecting them. The 160 N-terminal amino acids in the nonfinger region of clone 18 are highly homologous with similar regions of several other human, mouse, and Drosophila sequences, defining a subfamily of Krüppel-like zinc finger proteins termed TAB (tramtrack [ttk]-associated box) here. One of the Drosophila sequences, ttk, is a developmental control gene, while a second does not contain a zinc finger region but encodes a structure important in oocyte development. An acidic activation domain is located between the N-terminal conserved region of clone 18 and its zinc fingers. This protein appears to require both the S and J elements, which are separated by 10 bp for optimal binding. Antisense cDNA to clone 18 inhibited the expression of a reporter construct containing the DPA promoter, indicating its functional importance in the expression of this class II gene.

African swine fever virus specific porcine cytotoxic T cell activity

African swine fever virus (ASFV) specific, cytotoxic T lymphocyte (CTL) activity has been studied in a protection model in which SLA inbred miniature swine are experimentally inoculated with a naturally occurring, non-fatal ASFV isolate (NHV). Peripheral blood mononuclear cells (PBMC) from such infected swine show significant activity in CTL assays, using cultured ASFV-infected porcine blood derived macrophages as target cells. This CTL activity is elicited from PBMC by in vitro restimulation of effector cells with low doses (multiplicity of infection = 0.1) of the homologous virus isolate for 48 to 72 h. For SLAc/c effectors, this CTL activity appears to be SLA class I restricted because (1) blocking target cell antigens with monoclonal antibodies (mAb) against SLA class I antigens causes a major reduction in CTL activity; (2) there is preferential lysis of SLA class I matched, ASFV infected targets; and (3) depletion of effector cells with CD8 specific mAb and complement causes a reduction in CTL activity. The CTL activity is ASFV specific for all pigs tested in that infected macrophages are preferentially lysed as compared to normal (non-infected) cultured macrophages or macrophages infected with hog cholera virus (HCV). Lysis of macrophages infected with different ASFV isolates revealed that there is marked lysis of macrophages infected with the virulent L60 isolate but less lysis of macrophages infected with the DR-II and Tengani isolates. In summary, our data show that ASFV specific CTL activity is triggered in swine infected with the NHV ASFV isolate.

Hypomethylation of MHC class II Eb gene is associated with expression

Methylation patterns in the major histocompatibility complex (MHC) class II Eb locus have been analyzed in cell lines representative of different cell types; in particular those with phenotypes found at various stages of B cell development. A series of variant B cell lymphoma lines which serves as a model in which to investigate mechanisms regulating class II gene expression in normal peripheral B cells has been examined. Eb methylation patterns have also been determined in various healthy mouse tissues. The pattern of methylation of the Eb locus varies between different cell lines and tissue types such that hypomethylation is associated with gene expression. There appears to be a methylation pattern which is permissive for class II gene expression and which is characteristic of a variety of cell lines, but is lost in cell lines representing terminally differentiated class II nonexpressing plasma cells. Another methylation pattern has been identified which is found in cloned cell lines selected for expression of very high levels of cell surface class II product. The patterns of methylation associated with MHC class II expression involve changes in methylation sites located within the first intron and several kilobase pairs 5' of the promoter, but no changes were observed in the 3' end of the locus. Moreover, the different methylation patterns do not map to the prominent CpG rich cluster located 5' of the Eb promoter and which remains completely methylated regardless of transcriptional status.

2-[(2-pyridylmethyl)sulfinyl]-1H-thieno[3,4-d]imidazoles. A novel class of gastric H+/K(+)-ATPase inhibitors

2-[(2-Pyridylmethyl)sulfinyl]thienoimidazoles were synthesized and investigated as potential inhibitors of gastric H+/K(+)-ATPase. The [3,4-d] isomers of the two possible thienoimidazole series were found to be potent inhibitors of gastric acid secretion in vitro and in vivo. Structure-activity relationships indicate that especially lipophilic alkoxy, benzyloxy, and phenoxy substituents with additional electron-demanding properties in the 4-position of the pyridine moiety combined with an unsubstituted thieno[3,4-d]imidazole lead to highly active compounds with a favorable chemical stability. Various substitution patterns in the thieno[3,4-d]imidazole moiety result in lower biological activity. The heptafluorobutyloxy derivative saviprazole (HOE 731, 5d) was selected for further development and is currently undergoing clinical evaluation. Comprehensive pharmacological studies indicate a pharmacodynamic profile different to omeprazole, the first H+/K(+)-ATPase blocker introduced on the market.

Gastric acid inhibitory profile of saviprazole (HOE 731) compared to omeprazole

Saviprazole (HOE 731), a substituted thienoimidazole, caused a dose-dependent inhibition of gastric acid secretion in dogs and rats with ID50 values which were not significantly different from that of omeprazole indicating that both compounds are equally effective. The duration of action in dogs lasted for more than 24 h and was dependent on the state of stimulation. Measurement of serum concentrations of 1 mg/kg saviprazole after intravenous or intraduodenal administration revealed a bioavailability of about 60% in dogs. The elimination half-life was about 30 min following both routes of administration. In rats basal acid secretion was inhibited by saviprazole. In addition stimulation of acid secretion by histamine, desglugastrin, carbachol and isobutylmethylxanthine-forskolin was equally inhibited. This was in agreement with the known mechanism of action, inhibition of the gastric proton pump which is the last step of acid secretion within the parietal cell. Surprisingly, at high dose levels, saviprazole differed from omeprazole. After saviprazole, 1 mg/kg i.v. to dogs, acid output dropped to zero but recovered within 30 min to a level of 90%, whereas omeprazole depressed acid output completely over the whole observation period (4.5 h). Similar results were obtained in pylorus-ligated rats.

The inhibitory effect of HOE 731 in isolated rabbit gastric glands

HOE 731, a substituted thienoimidazole derivative, was studied on [14C] aminopyrine uptake and oxygen consumption in isolated rabbit gastric glands. HOE 731 caused a concentration-dependent inhibition of [14C]aminopyrine uptake during histamine and dbcAMP stimulation. The inhibition during dbcAMP stimulation was in accordance with its proton-pump inhibiting properties, which has already been reported. (Herling et al., Gastroenterology 96: A206, 1989). IC50 values were during histamine stimulation 0.8 +/- 0.3 microM and during dbcAMP stimulation 1.3 +/- 0.4 microM. The inhibition was reversible after addition of dithioerythritol and was of a non-competitive type. Omeprazole caused similar inhibitory effects in the same concentration-range. During time-course studies in glands, the inhibitory effect on [14C]aminopyrine uptake of 0.1 microM HOE 731 already appeared after 10 min of incubation but decreased with increasing incubation time, while 0.1 microM omeprazole caused an unchanged inhibition which started after 30 min of incubation. The concentration of 3 microM of HOE 731 and omeprazole caused a comparable constant inhibition. After pre-incubation for 135 min under basal conditions with subsequent stimulation of the glands with dbcAMP, the inhibitory effect of 10 microM HOE 731 also decreased in contrast to omeprazole. During stimulation for 4 hr, the inhibition of both compounds remained constant. In oxygen consumption studies HOE 731, at 100 microM, caused a strong inhibition down to basal values. This inhibitory effect could be prevented totally when 10 mM imidazole was added to neutralize the acidic compartment of the parietal cell during stimulation. It is concluded that HOE 731 needs acid-activation like omeprazole to inhibit the proton pump, but probably due to its chemical differences (stability, pH for conversion of HOE 731 to its active form) it shows a different inhibitory profile (faster transformation into its active moiety with faster onset of a partially reversible inhibition) as compared to omeprazole.

Antiviral activity and pharmacokinetics of HOE 602, an acyclic nucleoside, in animal models

The acyclic nucleoside derivative HOE 602 (2-amino-9-[1,3-bis(isopropoxy)-2-propoxymethyl]purine) was evaluated for its antiviral activity in cell culture and for its therapeutic efficacy in mice infected with herpes simplex virus type 1 (HSV-1) and type 2 (HSV-2) or with murine cytomegalovirus (MCMV). HOE 602 was inactive in vitro against a variety of DNA- and RNA-viruses. However it prevented symptoms and mortality in mice systemically infected with HSV-1, HSV-2 or MCMV when administered intraperitoneally or orally at a dosage of 100 mumol/kg twice per day. Pharmacokinetic studies in mice and macaques revealed that HOE 602 was converted via three metabolic steps to ganciclovir, which seemed to be the antivirally active compound. The bioavailability of ganciclovir after oral administration of HOE 602 or ganciclovir was similar in mice, while in rhesus monkeys much higher serum levels of ganciclovir were reached with HOE 602. After intraperitoneal or intravenous administration higher drug levels were obtained with ganciclovir. The excellent therapeutic efficacy in animal models, the high enteral absorption in monkeys, and the favourable physical properties will hopefully lead to an orally active drug against cytomegalovirus and severe herpes infections in man.

Virus-specific cellular blastogenesis and interleukin-2 production in swine after recovery from African swine fever

Animals recovered from viral diseases represent an important model to study the host cellular and humoral immune responses to the etiologic agents. This is particularly important for African swine fever virus (ASFV) infections in which antibodies have little or no virus-neutralizing effect. Pigs surviving experimental infection with the naturally occurring low-virulent, nonhemadsorbing ASFV/NH/P68 (NHV) isolate did, however, exhibit virus-specific T-cell activities, as measured by a variety of assays. A strong virus-induced, antigen-specific blastogenic response was observed only with blood mononuclear cells (BMC) from ASF-recovered swine, whereas cells from recovered and naive swine responded similarly to the mitogens concanavalin A and phytohemagglutinin. The ASFV-induced blastogenesis was dependent on virus dose and on the presence of adherent cells. Blood mononuclear cells cultured with antigenically related hemadsorbing ASFV isolates of different virulence characteristics, the highly virulent L60 isolate and moderately virulent DRII isolate, exhibited a similar magnitude of blastogenesis to cells infected with the low-virulent NHV isolate. Virus-infected cells proved to be an efficient inducer of interleukin-2 (IL-2) activity to cells from recovered swine, but not from naive swine, whereas T-cell-specific lectins induced production of similar amounts of IL-2 activity from cells of naive and recovered swine. Correlated with the appearance of virus-induced IL-2 activity in the culture supernatant was the induction of promiscuous killing in cells exposed to prolonged (7 days) virus stimulation.(ABSTRACT TRUNCATED AT 250 WORDS)