Macrophages inhibit Coxiella burnetii by the ACOD1-itaconate pathway for containment of Q fever

Infection with the intracellular bacterium Coxiella (C.) burnetii can cause chronic Q fever with severe complications and limited treatment options. Here, we identify the enzyme cis-aconitate decarboxylase 1 (ACOD1 or IRG1) and its product itaconate as protective host immune pathway in Q fever. Infection of mice with C. burnetii induced expression of several anti-microbial candidate genes, including Acod1. In macrophages, Acod1 was essential for restricting C. burnetii replication, while other antimicrobial pathways were dispensable. Intratracheal or intraperitoneal infection of Acod1^-/- mice caused increased C. burnetii burden, weight loss and stronger inflammatory gene expression. Exogenously added itaconate restored pathogen control in Acod1^-/- mouse macrophages and blocked replication in human macrophages. In axenic cultures, itaconate directly inhibited growth of C. burnetii. Finally, treatment of infected Acod1^-/- mice with itaconate efficiently reduced the tissue pathogen load. Thus, ACOD1-derived itaconate is a key factor in the macrophage-mediated defense against C. burnetii and may be exploited for novel therapeutic approaches in chronic Q fever.

MO048: Genome-wide studies reveal factors associated with circulating uromodulin and its relations with complex diseases

BACKGROUND AND AIMS

UMOD is a major risk gene for monogenic and complex forms of kidney disease. The encoded kidney-specific protein uromodulin is the most abundant protein in urine and related to chronic kidney disease, hypertension and pathogen defense. Through basolateral release from kidney epithelial cells, uromodulin also reaches the blood, where its function is largely unknown. To gain insights into potential systemic roles, we performed genome-wide screens of circulating uromodulin in seven cohorts using two complementary assays.

METHOD

Separate genome-wide association study meta-analyses for circulating uromodulin were conducted for the antibody-based assay (five cohorts, N = 13 985) and the aptamer-based SOMAscan assay (two cohorts, N = 18 070). Genome-wide significant loci were placed into their functional genomic context using RNA-seq, ATAC-seq and Hi-C data generated from primary human kidney tissue. An array of downstream genetic analyses was then performed for significant loci, including fine-mapping, colocalization analyses and gene-by-gene interaction analyses. The B4GALNT2 p.Cys466Arg allele was expressed in MDCK cells and studied by immunofluorescence and Western blotting analyses.

RESULTS

We detected and replicated 13 genome-wide significant loci (P <5e−8; 12 novel). At the UMOD locus, functional genomics data of primary human kidney tissue highlighted an upstream regulatory variant with differential accessibility and UMOD transcription in uromodulin-synthesizing kidney cells. Shared association patterns with complex traits, including chronic kidney disease and blood pressure, placed the PRKAG2 locus in the same context as UMOD. Experimental validation of another locus, B4GALNT2, showed that the detected p.Cys466Arg variant of the encoded N-acetylgalactosaminyltransferase has a loss-of-function effect leading to higher serum uromodulin levels. Lastly, our results point to enzymes writing glycan marks present on uromodulin and to their receptors in the circulation.

CONCLUSION

This study provides human genetic evidence of new pathway members of uromodulin and delivers novel insights into its determinants and systemic role in the circulation.

A Founder Mutation in EHD1 Presents with Tubular Proteinuria and Deafness

BACKGROUND

The endocytic reabsorption of proteins in the proximal tubule requires a complex machinery and defects can lead to tubular proteinuria. The precise mechanisms of endocytosis and processing of receptors and cargo are incompletely understood. EHD1 belongs to a family of proteins presumably involved in the scission of intracellular vesicles and in ciliogenesis. However, the relevance of EHD1 in human tissues, in particular in the kidney, was unknown.

METHODS

Genetic techniques were used in patients with tubular proteinuria and deafness to identify the disease-causing gene. Diagnostic and functional studies were performed in patients and disease models to investigate the pathophysiology.

RESULTS

We identified six individuals (5-33 years) with proteinuria and a high-frequency hearing deficit associated with the homozygous missense variant c.1192C>T (p.R398W) in EHD1. Proteinuria (0.7-2.1 g/d) consisted predominantly of low molecular weight proteins, reflecting impaired renal proximal tubular endocytosis of filtered proteins. Ehd1 knockout and Ehd1R398W/R398W knockin mice also showed a high-frequency hearing deficit and impaired receptor-mediated endocytosis in proximal tubules, and a zebrafish model showed impaired ability to reabsorb low molecular weight dextran. Interestingly, ciliogenesis appeared unaffected in patients and mouse models. In silico structural analysis predicted a destabilizing effect of the R398W variant and possible inference with nucleotide binding leading to impaired EHD1 oligomerization and membrane remodeling ability.

CONCLUSIONS

A homozygous missense variant of EHD1 causes a previously unrecognized autosomal recessive disorder characterized by sensorineural deafness and tubular proteinuria. Recessive EHD1 variants should be considered in individuals with hearing impairment, especially if tubular proteinuria is noted.

MO492SELF-REPORTED MEDICATION USE AND URINARY DRUG METABOLITES IN THE GERMAN CHRONIC KIDNEY DISEASE (GCKD) STUDY: A PHARMACOMETABOLOMIC APPROACH

Background and Aims

Chronic kidney disease (CKD) patients are prone to prescription of multiple medications. Medication adherence is a well-recognized problem in the management of patients with chronic diseases requiring polypharmacy. This study aimed to evaluate the connection between self-reported medication use and urine drug metabolite levels in a large cohort of CKD patients, the GCKD study, as a basis for future pharmacometabolomics studies.

Method

Self-reported medication use of 160 substances and 41 medication groups was ascertained at study baseline and coded according to the Anatomical Therapeutic Chemical classification system. A non-targeted mass spectrometry-based approach (Metabolon HD4™) was used for concomitant metabolite quantification in urine. Specificity, sensitivity and accuracy of medication use and the corresponding urine metabolite measurements were calculated. Multivariable regression models (adjusted to age, sex, eGFR, log(UACR), systolic blood pressure, LDL, log(triglycerides), log(HBA1c) were used to establish associations in prescription patterns.

Results

Among 4,885 participants, 78 drug metabolites were detected in urine (frequency range: 0.4-58%) and assigned into 110 medication – drug metabolite pairs (MMPs) based on reported individual substances and medication groups. For all 68 MMPs of individual substances, accuracy of medication use and the corresponding drug metabolite measurement was excellent (median 97.0%, range 43%-100%), as was measurement-based specificity (median 99.3%, range 73.3%-100%; Fig. 1). Median measurement-based sensitivity was 72.1% (range 1.1%-100%, Fig. 1). Sensitivity and specificity were especially high for angiotensin-II receptor blockers (92%-96%; 99-100%), calcium channel blockers (85-100%; 91-100%), and metoprolol (90%; 98% respectively) commonly prescribed and important medications for blood pressure control and cardiovascular risk reduction in CKD patients. MMPs showing sensitivity <80% included several substances found in over-the-counter (OTC) analgesic medications, suggesting that their use is not always reported. While self-reported use of the OTC analgesics acetaminophen and ibuprofen was <3% each, their corresponding drug metabolites indicated higher usage (acetaminophen: 10-26%; ibuprofen: 10-18%, depending on the number of evaluated drug metabolites). Typical examples of medication co-prescriptions (e.g., trimethoprim and sulfamethoxazole) were detected as the combined presence of their drug metabolites in urine. This result validates the abstraction of single substances from combination medications and this urine-based metabolomic approach.

Conclusion

This study provides a comprehensive screen of the associations between urine drug metabolite levels and self-reported medication use. It supports the usefulness of pharmacometabolomics to assess medication use, frequency of OTC analgesics use, and prescription patterns in persons with CKD.

MO482URINE METABOLITE LEVELS OF CKD PATIENTS ARE ASSOCIATED WITH ADVERSE KIDNEY OUTCOMES AND MORTALITY*

Background and Aims

Chronic kidney disease (CKD) affects >10% of the adult population worldwide and is associated with increased risk of kidney failure (KF) and mortality. Mechanisms underlying the variable course of disease progression are incompletely understood. This study aimed at identifying novel metabolite biomarkers of adverse kidney outcomes and overall mortality, which may offer insights into pathophysiological mechanisms.

Method

Using measurements of 1,487 metabolites in urine of 5,087 CKD patients enrolled in the German Chronic Kidney Disease study, we evaluated the association of urine metabolite levels with adverse events. Main endpoints include KF, a combined endpoint of KF and acute kidney injury (KF+AKI), and overall mortality. Statistical analysis was based on a discovery-replication design (ratio 2:1) and multivariable adjusted Cox regression models. We performed cause-specific hazard regression as well as subdistribution hazard analyses with death of other causes as a competing event for the endpoints KF and KF+AKI. Statistical significance was defined using a Bonferroni correction for the number of tested metabolites per stage. An association was considered replicated if effect estimates from both stages were significant and direction-consistent.

Results

Median follow-up time was 4 years. At time of analysis, 362 patients died, 241 experienced KF, and 382 KF+AKI. Overall, we identified 55 urine metabolites whose levels were significantly and reproducibly associated with adverse kidney outcomes and/or mortality. Cause-specific and subdistribution hazard analyses showed almost identical results. Higher levels of the amino acid C-glycosyltryptophan in urine were associated with higher risk for all three endpoints (KF: hazard ratio 1.43, 95% confidence interval [1.27;1.61], KF+AKI: 1.40 [1.27;1.55], mortality: 1.47 [1.33;1.63]). The cumulative incidence function of KF was higher for each quartile of urine C-glycosyltryptophan levels and the effect were most pronounced in the highest quartile (see Figure). The replicated metabolites belong to different biochemical classes, and those belonging to the phosphatidylcholines pathway showed enrichment. Members of this pathway contributed to the improvement of the prediction performance for KF observed when multiple metabolites were added to the well-established kidney failure risk equation by Tangri.

Conclusion

This comprehensive screen of the association between urine metabolite levels and adverse kidney outcomes and mortality identified and replicated 55 urine metabolites associated with adverse kidney events, potentially providing new insights into the mechanisms of kidney disease progression. The study represents a valuable resource for future experimental studies of biomarkers of CKD progression.

Third-party fecal microbiota transplantation following allo-HCT reconstitutes microbiome diversity

We hypothesized that third-party fecal microbiota transplantation (FMT) may restore intestinal microbiome diversity after allogeneic hematopoietic cell transplantation (allo-HCT). In this open-label single-group pilot study, 18 subjects were enrolled before allo-HCT and planned to receive third-party FMT capsules. FMT capsules were administered no later than 4 weeks after neutrophil engraftment, and antibiotics were not allowed within 48 hours before FMT. Five patients did not receive FMT because of the development of early acute gastrointestinal (GI) graft-versus-host disease (GVHD) before FMT (n = 3), persistent HCT-associated GI toxicity (n = 1), or patient decision (n = 1). Thirteen patients received FMT at a median of 27 days (range, 19-45 days) after HCT. Participants were able to swallow and tolerate all FMT capsules, meeting the primary study endpoint of feasibility. FMT was tolerated well, with 1 treatment-related significant adverse event (abdominal pain). Two patients subsequently developed acute GI GVHD, with 1 patient also having concurrent bacteremia. No additional cases of bacteremia occurred. Median follow-up for survivors is 15 months (range, 13-20 months). The Kaplan-Meier estimates for 12-month overall survival and progression-free survival after FMT were 85% (95% confidence interval, 51%-96%) and 85% (95% confidence interval, 51%-96%), respectively. There was 1 nonrelapse death resulting from acute GI GVHD (12-month nonrelapse mortality, 8%; 95% confidence interval, 0%-30%). Analysis of stool composition and urine 3-indoxyl sulfate concentration indicated improvement in intestinal microbiome diversity after FMT that was associated with expansion of stool-donor taxa. These results indicate that empiric third-party FMT after allo-HCT appears to be feasible, safe, and associated with expansion of recipient microbiome diversity. This trial was registered at www.clinicaltrials.gov as #NCT02733744.

The association between acute graft-versus-host disease and antimicrobial peptide expression in the gastrointestinal tract after allogeneic stem cell transplantation

Intestinal microbiota disruption is associated with acute gastrointestinal (GI) Graft-versus-Host Disease (GvHD) and poor outcome after allogeneic stem cell transplantation (ASCT). Here, in a retrospective analysis of 200 patients undergoing ASCT at the Regensburg University Medical Center, we assessed the relative expression of Paneth cell antimicrobial peptides (AMPs), Human Defensins (HD) 5 and 6 and regenerating islet-derived 3α (Reg3α), in 292 human intestinal biopsies as well as Reg3α serum levels in relation to acute GI GvHD. In the absence of GI GvHD, the relative expression of Paneth cell AMPs was significantly higher in the small intestine (duodenum to ileum) than in the stomach and large intestine (cecum to rectum) for Reg3α (p≤0.001), HD5 (p≤0.002) and HD6 (p≤0.02). Acute stage 2-4 GI GvHD was associated with reduced expression of AMPs in the small intestine (p≤0.01) in comparison to stage 0-1 disease, accompanied by a decrease in Paneth cell count in case of severe acute GI GvHD (p<0.001). The opposite held true for the large intestine as we found stage 2-4 GI GvHD correlated with significantly higher expression of HD5, HD6, and Reg3α compared to mild or no acute GI GvHD (p≤0.002). Severe GI GvHD in both the lower and the upper GI tract also correlated with higher serum concentrations of Reg3α (p = 0.002). As indirect markers of intestinal microbiome diversity low levels of urinary 3-indoxyl sulfate levels were associated with severe stages of acute GI GvHD compared to mild stage or no acute GI GvHD (p = 0.05). In conclusion, acute GI GvHD correlates with intestinal expression of HD5, HD6 and Reg3α as well as Reg3α serum levels and is associated with intestinal dysbiosis.

Hypoxia-inducible protein 2 Hig2/Hilpda mediates neutral lipid accumulation in macrophages and contributes to atherosclerosis in apolipoprotein E-deficient mice

Recently we identified hypoxia-inducible protein 2 (HIG2)/hypoxia-inducible lipid droplet-associated (HILPDA) as lipid droplet (LD) protein. Because HILPDA is highly expressed in atherosclerotic plaques, we examined its regulation and function in murine macrophages, compared it to the LD adipose differentiation-related protein (Adrp)/perilipin 2 (Plin2), and investigated its effects on atherogenesis in apolipoprotein E-deficient (ApoE^-/-) mice. Tie2-Cre-driven Hilpda conditional knockout (cKO) did not affect viability, proliferation, and ATP levels in macrophages. Hilpda proved to be a target of hypoxia-inducible factor 1 (Hif-1) and peroxisome proliferator-activated receptors. In contrast, Adrp/Plin2 was not induced by Hif-1. Hilpda localized to the endoplasmic reticulum-LD interface, the site of LD formation. Hypoxic lipid accumulation and storage of oxidized LDL, cholesteryl esters and triglycerides were abolished in Hilpda cKO macrophages, independent of the glycolytic switch, fatty acid or lipoprotein uptake. Hilpda depletion reduced resistance against lipid overload and increased production of reactive oxygen species after reoxygenation. LPS-stimulated prostaglandin-E2 production was dysregulated in macrophages, demonstrating the substrate buffer and reservoir function of LDs for eicosanoid production. In ApoE^-/- Hilpda cKO mice, total aortic plaque area, plaque macrophages and vascular Vegf expression were reduced. Thus, macrophage Hilpda is crucial to foam-cell formation and lipid deposition, and to controlled prostaglandin-E2 production. By these means Hilpda promotes lesion formation and progression of atherosclerosis.-Maier, A., Wu, H., Cordasic, N., Oefner, P., Dietel, B., Thiele, C., Weidemann, A., Eckardt, K.-U., Warnecke, C. Hypoxia-inducible protein 2 Hig2/Hilpda mediates neutral lipid accumulation in macrophages and contributes to atherosclerosis in apolipoprotein E-deficient mice.

Distinct von Hippel-Lindau gene and hypoxia-regulated alterations in gene and protein expression patterns of renal cell carcinoma and their effects on metabolism

During the last decade the knowledge about the molecular mechanisms of the cellular adaption to hypoxia and the function of the "von Hippel Lindau" (VHL) protein in renal cell carcinoma (RCC) has increased, but there exists little information about the overlap and differences in gene/protein expression of both processes. Therefore the aim of this study was to dissect VHL- and hypoxia-regulated alterations in the metabolism of human RCC using ome-based strategies. The effect of the VHL- and hypoxia-regulated altered gene/protein expression pattern on the cellular metabolism was analyzed by determination of glucose uptake, lactate secretion, extracellular pH, lactate dehydrogenase activity, amino acid content and ATP levels. By employing VHL-/VHL(+) RCC cells cultured under normoxic and hypoxic conditions, VHL-dependent, HIF-dependent as well as VHL-/HIF-independent alterations in the gene and protein expression patterns were identified and further validated in other RCC cell lines. The genes/proteins differentially expressed under these distinct conditions were mainly involved in the cellular metabolism, which was accompanied by an altered metabolism as well as changes in the abundance of amino acids in VHL-deficient cells. In conclusion, the study reveals similarities, but also differences in the genes and proteins controlled by VHL functionality and hypoxia thereby demonstrating differences in the metabolic switch of RCC under these conditions.

Metabolic plasticity of human T cells: Preserved cytokine production under glucose deprivation or mitochondrial restriction, but 2-deoxy-glucose affects effector functions

The strong link between T-cell metabolism and effector functions is well characterized in the murine system but hardly investigated in human T cells. Therefore, we analyzed glycolytic and mitochondrial activity in correlation to function in activated human CD4 and CD8 T cells. Glycolysis was barely detectable upon stimulation but accelerated beyond 24 h, whereas mitochondrial activity was elevated immediately in both T-cell populations. Glucose deprivation or mitochondrial restriction reduced proliferation, had only a transient impact on "on-blast formation" and no impact on viability, IFN-γ, IL-2, IL-4, and IL-10 production, whereas TNF was reduced. Similar results were obtained in bulk T cells and T-cell subsets. Elevated respiration under glucose restriction demonstrated metabolic flexibility. Administration of the glycolytic inhibitor 2-deoxy-glucose suppressed both glycolysis and respiration and exerted a strong impact on cytokine production that persisted for IFN-γ after removal of 2-deoxy-glucose. Taken together, glycolytic or mitochondrial restriction alone compromised proliferation of human T cells, but barely affected their effector functions. In contrast, effector functions were severely affected by 2-deoxy-glucose treatment.

Central European BRCA2 mutation carriers: birth cohort status correlates with onset of breast cancer

BACKGROUND

Mutations in brca1 and 2 genes lead to a significant increase in the lifetime risk of developing breast (BC) and ovarian cancer (OC). There are indications that birth cohort can influence the cancer risk in brca1 mutation carriers. Therefore, we investigated the risks for BC and OC associated with brca2 mutations in a cohort of female mutation carriers of a genetically heterogeneous Central European population.

PATIENTS AND METHODS

This study included 246 women in whom a functional mutation in the brca2 gene had been identified at our institution. At the time of analysis, 153 women had developed cancer (142 BC, 9 OC, 2 BC and OC). Risks were estimated using the product limit method. The log rank test was used to compare different strata.

RESULTS

After correction for risk-reducing surgeries, the cumulative risk of developing cancer to age 70 was found to be 88% for BC (95% CI 81-95%) and 31% for OC (95% CI 17-45%). Female brca2 mutation carriers born in 1958 or later were at a significantly higher risk of developing BC at a younger age (p<0.001), while no such age cohort-dependent correlation was found for OC.

CONCLUSION

The age cohort-dependent early onset in BC in women born after 1958 strongly suggests the importance of exogenous factors such as lifestyle modification while this does not seem to be the case for OC. Female brca2 mutation carriers should be counseled about their age cohort-dependent breast cancer risk.

Presenilin 1/γ-secretase modulates P-cadherin processing and influences cell adhesion in oral squamous cell carcinoma cell lines

P-cadherin belongs to a family of Ca(2+)-dependent homophilic cell-cell adhesion proteins that are important for correct cellular localization and tissue integrity in the oral epithelium. P-cadherin is only expressed in the basal and suprabasal cell layers of the oral epithelium, but in advanced oral squamous cell carcinoma (OSCC), a reduced membranous and an enhanced cytoplasmic truncated P-cadherin level is observed. In this study, we investigated the impact of presenilin (PS) 1/γ-secretase on P-cadherin processing in OSCC. Western blot analyses showed an enhanced PS1 expression in OSCC cell lines and in primary oral keratinocytes (POK) isolated from primary OSCC tissue (OSCC POK) compared with POKs isolated from normal oral mucosa. Immunocytochemical stainings and co-immunoprecipitation experiments revealed a cytoplasmic colocalization and a direct interaction of P-cadherin and PS1 in OSCC POKs. Blocking of PS1/γ-secretase activity by the PS1/γ-secretase inhibitors and N-[N-(3,5-difluorophenacetyl)-L-alanyl]-S-phenylglycine t-butyl ester, another specific γ-secretase inhibitor yielded a 100 kDa P-cadherin band on western blots of OSCC cell line extracts. Small interfering RNA knockdown of PS1 equally generated a 100 kDa P-cadherin form in OSCC POKs. Mass spectrometry analyses and experiments with the glycosylation inhibitor tunicamycin characterized the appearing 100 kDa P-cadherin band as the unglycosylated full-length form of P-cadherin. On the functional level, cell attachment assays demonstrated an enhanced cell adhesion after PS1/γ-secretase inhibition only in the transiently P-cadherin expressing OSCC cell line PCI52 but not in the PCI52 control cells. In summary, our results show that PS1/γ-secretase contributes to P-cadherin processing and to reduced cell adhesion in OSCC.

The German Chronic Kidney Disease (GCKD) study: design and methods

BACKGROUND

Chronic kidney disease (CKD) is increasingly recognized as a global health problem. The conditions leading to CKD, the health impact of CKD and the prognosis differ markedly between affected individuals. In particular, renal failure and cardiovascular mortality are competing risks for CKD patients. Opportunities for targeted intervention are very limited so far and require an improved understanding of the natural course of CKD, of the risk factors associated with various clinical end points and co-morbidities as well as of the underlying pathogenic mechanisms.

METHODS

The German Chronic Kidney Disease (GCKD) study is a prospective observational national cohort study. It aims to enrol a total of 5000 patients with CKD of various aetiologies, who are under nephrological care, and to follow them for up to 10 years. At the time of enrolment, male and female patients have an estimated glomerular filtration rate (eGFR) of 30-60 mL/min×1.73 m2 or overt proteinuria in the presence of an eGFR>60 mL/min×1.73 m2. Standardized collection of biomaterials, including DNA, serum, plasma and urine will allow identification and validation of biomarkers associated with CKD, CKD progression and related complications using hypothesis-driven and hypothesis-free approaches. Patient recruitment and follow-up is organized through a network of academic nephrology centres collaborating with practising nephrologists throughout the country.

CONCLUSIONS

The GCKD study will establish one of the largest cohorts to date of CKD patients not requiring renal replacement therapy. Similarities in its design with other observational CKD studies, including cohorts that have already been established in the USA and Japan, will allow comparative and joint analyses to identify important ethnic and geographic differences and to enhance opportunities for identification of relevant risk factors and markers.

Kinetic laws, phase-phase expansions, renormalization group, and INR calibration

We introduce systematic approaches to chemical kinetics based on the use of phase-phase (log-log) representations of the rate equations. For slow processes, we obtain a corrected form of the mass-action law, where the concentrations are replaced by kinetic activities. For fast reactions, delay expressions are derived. The phase-phase expansion is, in general, applicable to kinetic and transport processes. A mechanism is introduced for the occurrence of a generalized mass-action law as a result of self-similar recycling. We show that our self-similar recycling model applied to prothrombin assays reproduces the empirical equations for the International Normalized Ratio calibration (INR), as well as the Watala, Golanski, and Kardas relation (WGK) for the dependence of the INR on the concentrations of coagulation factors. Conversely, the experimental calibration equation for the INR, combined with the experimental WGK relation, without the use of theoretical models, leads to a generalized mass-action type kinetic law.

Deficiency in glutamine but not glucose induces MYC-dependent apoptosis in human cells

The idea that conversion of glucose to ATP is an attractive target for cancer therapy has been supported in part by the observation that glucose deprivation induces apoptosis in rodent cells transduced with the proto-oncogene MYC, but not in the parental line. Here, we found that depletion of glucose killed normal human cells irrespective of induced MYC activity and by a mechanism different from apoptosis. However, depletion of glutamine, another major nutrient consumed by cancer cells, induced apoptosis depending on MYC activity. This apoptosis was preceded by depletion of the Krebs cycle intermediates, was prevented by two Krebs cycle substrates, but was unrelated to ATP synthesis or several other reported consequences of glutamine starvation. Our results suggest that the fate of normal human cells should be considered in evaluating nutrient deprivation as a strategy for cancer therapy, and that understanding how glutamine metabolism is linked to cell viability might provide new approaches for treatment of cancer.

Random activation energy model and disordered kinetics, from static to dynamic disorder

We suggest a unified path integral approach for random rate processes with random energy barriers, which includes systems with static and dynamic disorder as particular cases. We assume that the random component of the activation energy barrier can be described by a generalized Zubarev-McLennan nonequilibrum statistical ensemble that can be derived from the maximum information entropy approach by assuming that the time history of the fluctuations of the random components of the energy barrier are known. We show that the average survival function, which is an experimental observable in disorderd kinetics, can be computed exactly in terms of the characteristic functional of this generalized Zubarev-McLennan nonequilibrium statistical ensemble. We investigate different types of disorder described by our approach, ranging from static disorder with infinite memory to random processes with long or short memory, and finally to rapidly fluctuating independent random processes with no memory. We derive expressions of the average survival function for all these types of disorder and discuss their implications in the evaluation of kinetic parameters from experimental data. We illustrate our approach by studying a simple model of dynamic disorder of the renewal type. Finally we discuss briefly the implications of our approach in molecular biology and genetics.

Revealing the prehistoric settlement of Australia by Y chromosome and mtDNA analysis

Published and new samples of Aboriginal Australians and Melanesians were analyzed for mtDNA (n=172) and Y variation (n=522), and the resulting profiles were compared with the branches known so far within the global mtDNA and the Y chromosome tree. (i) All Australian lineages are confirmed to fall within the mitochondrial founder branches M and N and the Y chromosomal founders C and F, which are associated with the exodus of modern humans from Africa approximately 50-70,000 years ago. The analysis reveals no evidence for any archaic maternal or paternal lineages in Australians, despite some suggestively robust features in the Australian fossil record, thus weakening the argument for continuity with any earlier Homo erectus populations in Southeast Asia. (ii) The tree of complete mtDNA sequences shows that Aboriginal Australians are most closely related to the autochthonous populations of New Guinea/Melanesia, indicating that prehistoric Australia and New Guinea were occupied initially by one and the same Palaeolithic colonization event approximately 50,000 years ago, in agreement with current archaeological evidence. (iii) The deep mtDNA and Y chromosomal branching patterns between Australia and most other populations around the Indian Ocean point to a considerable isolation after the initial arrival. (iv) We detect only minor secondary gene flow into Australia, and this could have taken place before the land bridge between Australia and New Guinea was submerged approximately 8,000 years ago, thus calling into question that certain significant developments in later Australian prehistory (the emergence of a backed-blade lithic industry, and the linguistic dichotomy) were externally motivated.

Transition Event Statistics in Genetics and Disordered Kinetics. Theoretical Approaches for Extracting Rate Distributions from Experimental Data

We study the analogies between the theory of rate processes in disordered systems and the overdispersed molecular clocks in evolutionary biology. A biological "molecular clock" expresses the statistics of the number of amino acid or nucleotide substitutions during evolution. Random variations of the evolution rates lead to statistical (overdispersed) molecular clocks which are described by random point processes with random substitution rates. We find that the models for overdispersed molecular clocks are equivalent to those of the random-rate or random channel models used in disordered kinetics. The number of transport (reaction) events in disordered kinetics plays the same role as the number of substitution events in molecular biology. We study the connections between the (observed) statistics of the transition events and the statistics of random rate coefficients and random channels; a unified approach is developed which is valid both in molecular biology and in disordered kinetics. We develop methods for extracting statistical information about the variations of rate coefficients from experimental or observed data regarding the fluctuations of the numbers of substitution, reaction, or transport events. For systems with static disorder, the observed statistics of the number of reaction events, expressed in terms of probabilities at a given time or by the cumulants of the number of transition events at a given time, contains the information necessary for evaluating the cumulants or the probability density of the rate coefficients or the density of states for random channel kinetics. For dynamic disorder this is not possible; further information about multitime probability distributions of the reaction events is needed.

FEM1A is a candidate gene for polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is the most common endocrine disorder among women of reproductive age, and is characterized by infertility, hyperandrogenism and insulin resistance in skeletal muscle. There is evidence for a PCOS gene localized to chromosome 19p13.3. The FEMIA gene maps to chromosome 19p13.3 and is highly expressed in skeletal muscle. FEMIA is a homolog of fem-1, a sex-determination gene of Caenorhabditis elegans that controls masculinization. In a pilot study of Caucasian PCOS patients from our local clinic, we found that one of these five patients exhibited a heterozygous germline missense mutation in FEM1A, designated FEM1A*H500Y. This mutation alters an amino acid conserved from human to C. elegans, and was not found in any of 198 control chromosomes. This missense allele was not found in any of a separate group of 30 PCOS patients from a different regional/ethnic background. Immunostaining of mouse ovary demonstrated that the mouse homolog of FEM1A is expressed in androgen-producing secondary interstitial cells, with a marked increase in expression after puberty, consistent with a key feature of PCOS -- ovarian hyperandrogenism. In conclusion, FEM1A should be considered a candidate gene for PCOS, and more extensive analysis of FEM1A, both coding and regulatory sequences, is warranted in patients and families with PCOS.

Fisher's theorems for multivariable, time- and space-dependent systems, with applications in population genetics and chemical kinetics

We study different physical, chemical, or biological processes involving replication, transformation, and disappearance processes, as well as transport processes, and assume that the time and space dependence of the species densities are known. We derive two types of Fisher equations. The first type relates the average value of the time derivative of the relative time-specific rates of growth of the different species to the variance of the relative, time-specific rates of growth. A second type relates the average value of the gradient or the divergence of the relative, space-specific rates of growth to the space correlation matrix of the relative, space-specific rates of growth. These Fisher equations are exact results, which are independent of the detailed kinetics of the process: they are valid whether the evolution equations are linear or nonlinear, local or nonlocal in space and/or time and can be applied for the study of a large class of physical, chemical, and biological systems described in terms of time- and/or space-dependent density fields. We examine the implications of our generalized Fisher relations in population genetics, biochemistry, and chemical kinetics (reaction-diffusion systems). We show that there is a connection between the enhanced (hydrodynamic) transport of mutations induced by population growth and space-specific rate vectors: the velocity of enhanced transport is proportional to the product of the diffusion coefficient of the species and the space rate vector; this relation is similar to a fluctuation-dissipation relation in statistical mechanics.

Task-specific expression of the foraging gene in harvester ants

In social insects, groups of workers perform various tasks such as brood care and foraging. Transitions in workers from one task to another are important in the organization and ecological success of colonies. Regulation of genetic pathways can lead to plasticity in social insect task behaviour. The colony organization of advanced eusocial insects evolved independently in ants, bees, and wasps and it is not known whether the genetic mechanisms that influence behavioural plasticity are conserved across species. Here we show that a gene associated with foraging behaviour is conserved across social insect species, but the expression patterns of this gene are not. We cloned the red harvester ant (Pogonomyrmex barbatus) ortholog (Pbfor) to foraging, one of few genes implicated in social organization, and found that foraging behaviour in harvester ants is associated with the expression of this gene; young (callow) worker brains have significantly higher levels of Pbfor mRNA than foragers. Levels of Pbfor mRNA in other worker task groups vary among harvester ant colonies. However, foragers always have the lowest expression levels compared to other task groups. The association between foraging behaviour and the foraging gene is conserved across social insects but ants and bees have an inverse relationship between foraging expression and behaviour.

TwoATM variants and breast cancer risk

The ATM gene is mutated in ataxia-telangiectasia (AT). Heterozygote female relatives of AT cases have a 2-7fold increased risk of breast cancer. We previously reported high risks of breast cancer associated with certain ATM variants. To estimate the risks more precisely, we have examined two ATM variants, c.1066-6T>G (IVS10-6T>G) and c.4258C>T (p.Leu1420Phe), in additional cases and controls from the same Australian cohorts previously used to estimate the risk of breast cancer associated with c.1066-6T>G. A total of 775 and 84 population-based controls were genotyped for the c.1066-6T>G and c.4258C>T ATM variants respectively, as were index cases from 378 and 373 non-BRCA1/2 breast cancer families. Penetrance was estimated by Bayes factor analysis. The allele frequencies of ATM c.1066-6T>G and c.4258C>T estimated from controls were 0.005 (95% CI=0.002 to 0.009) and 0.012 (95% CI=0.001 to 0.042), respectively. We identified three new breast cancer families with c.1066-6T>G, and seven families with c.4258C>T. Combining with the two c.1066-6T>G families previously reported, the estimated penetrance to age 70 of c.1066-6T>G was 17.2% (95% CI=4.7% to 37.5%). For c.4258C>T, the estimated average penetrance was 4.8% (95% CI 1.7% to 10.1%). In conclusion, we found no evidence that the ATM c.4258C>T variant increases breast cancer risk, and little evidence that c.1066-6T>G confers an elevated risk. Analysis of additional families will be necessary to define more precisely the risk, if any, associated with c.1066-6T>G.

Peopling of three Mediterranean islands (Corsica, Sardinia, and Sicily) inferred by Y-chromosome biallelic variability

An informative set of biallelic polymorphisms was used to study the structure of Y-chromosome variability in a sample from the Mediterranean islands of Corsica and Sicily, and compared with data on Sardinia to gain insights into the ethnogenesis of these island populations. The results were interpreted in a broader Mediterranean context by including in the analysis neighboring populations previously studied with the same methodology. All samples studied were enclosed in the comparable spectrum of European Y-chromosome variability. Pronounced differences were observed between the islands as well as in the percentages of haplotypes previously shown to have distinctive patterns of continental phylogeography. Approximately 60% of the Sicilian haplotypes are also prevalent in Southern Italy and Greece. Conversely, the Corsican sample had elevated levels of alternative haplotypes common in Northern Italy. Sardinia showed a haplotype ratio similar to that observed in Corsica, but with a remarkable difference in the presence of a lineage defined by marker M26, which approaches 35% in Sardinia but seems absent in Corsica. Although geographically adjacent, the data suggest different colonization histories and a minimal amount of recent gene flow between them. Our results identify possible ancestral continental sources of the various island populations and underscore the influence of founder effect and genetic drift. The Y-chromosome data are consistent with comparable mtDNA data at the RFLP haplogroup level of resolution, as well as linguistic and historic knowledge.

Reduced Y-chromosome, but not mitochondrial DNA, diversity in human populations from West New Guinea

To investigate the paternal population history of New Guinea, 183 individuals from 11 regional populations of West New Guinea (WNG) and 131 individuals from Papua New Guinea (PNG) were analyzed at 26 binary markers and seven short-tandem-repeat loci from the nonrecombining part of the human Y chromosome and were compared with 14 populations of eastern and southeastern Asia, Polynesia, and Australia. Y-chromosomal diversity was low in WNG compared with PNG and with most other populations from Asia/Oceania; a single haplogroup (M-M4) accounts for 75% of WNG Y chromosomes, and many WNG populations have just one Y haplogroup. Four Y-chromosomal lineages (haplogroups M-M4, C-M208, C-M38, and K-M230) account for 94% of WNG Y chromosomes and 78% of all Melanesian Y chromosomes and were identified to have most likely arisen in Melanesia. Haplogroup C-M208, which in WNG is restricted to the Dani and Lani, two linguistically closely related populations from the central and western highlands of WNG, was identified as the major Polynesian Y-chromosome lineage. A network analysis of associated Y-chromosomal short-tandem-repeat haplotypes suggests two distinct population expansions involving C-M208--one in New Guinea and one in Polynesia. The observed low levels of Y-chromosome diversity in WNG contrast with high levels of mtDNA diversity reported for the same populations. This most likely reflects extreme patrilocality and/or biased male reproductive success (polygyny). Our data further provide evidence for primarily female-mediated gene flow within the highlands of New Guinea but primarily male-mediated gene flow between highland and lowland/coastal regions.

Monolithic capillary columns for liquid chromatography-electrospray ionization mass spectrometry in proteomic and genomic research

Peptides, proteins, single-stranded oligonucleotides, and double-stranded DNA fragments were separated with high resolution in micropellicular, monolithic capillary columns prepared by in situ radical copolymerization of styrene and divinylbenzene. Miniaturized chromatography both in the reversed-phase and the ion-pair reversed-phase mode could be realized in the same capillary column because of the nonpolar character of the poly-(styrene/divinylbenzene) stationary phase. The high chromatographic performance of the monolithic stationary phase facilitated the generation of peak capacities for the biopolymers in the range of 50-140 within 10 min under gradient elution conditions. Employing volatile mobile phase components, separations in the two chromatographic separation modes were on-line hyphenated to electrospray ionization (tandem) mass spectrometry, which yielded intact accurate molecular masses as well as sequence information derived from collision-induced fragmentation. The inaccuracy of mass determination in a quadrupole ion trap mass spectrometer was in the range of 0.01-0.02% for proteins up to a molecular mass of 20000, and 0.02-0.12% for DNA fragments up to a molecular mass of 310000. High-performance liquid chromatography-electrospray ionization mass spectrometry utilizing monolithic capillary columns was applied to the identification of proteins by peptide mass fingerprinting, tandem mass spectrometric sequencing, or intact molecular mass determination, as well as to the accurate sizing of double-stranded DNA fragments ranging in size from 50 to 500 base pairs, and to the detection of sequence variations in DNA fragments amplified by the polymerase chain reaction.

Premature termination mutations in FBN1: distinct effects on differential allelic expression and on protein and clinical phenotypes

Marfan syndrome (MFS) and other type 1 fibrillinopathies result from mutations in the FBN1 gene, which encodes the connective-tissue microfibrillar protein fibrillin 1. Attempts at correlating genotype with phenotype have suggested considerable heterogeneity. To define the subtype of fibrillinopathy caused by premature termination codon (PTC) mutations, we integrate genotype information and mRNA expression levels with clinical and biochemical phenotypes. By screening the entire FBN1 gene for mutations, we identified 34 probands with PTC mutations. With the exception of two recurrent mutations, these nonsense and frameshift mutations are unique and span the entire FBN1 gene, from IVS2 to IVS63. Allele-specific reverse-transcriptase polymerase chain reaction analyses revealed differential allelic expression in all studied samples, with variable reduction of the mutant transcript. Fibrillin protein synthesis and deposition into the extracellular matrix were studied by pulse-chase analysis of cultured fibroblasts. In the majority of PTC samples, synthesis of normal-sized fibrillin protein was approximately 50% of control levels, but matrix deposition was disproportionately decreased. Probands and mutation-positive relatives were clinically evaluated by means of a standardized protocol. Only 71% (22/31) of probands and 58% (14/24) of the mutation-positive family members met current clinical diagnostic criteria for MFS. When compared with our previously reported study group of 44 individuals with FBN1 cysteine substitutions, the PTC group showed statistically significant differences in the frequency of individual signs, especially in the ocular manifestations. Whereas large-joint hypermobility was more common, lens dislocation and retinal detachment were distinctly less common in the PTC group. We conclude that PTC mutations have a major impact on the pathogenesis of type 1 fibrillinopathies and convey a distinct biochemical, clinical, and prognostic profile.

Bayesian analysis of systems with random chemical composition: renormalization-group approach to Dirichlet distributions and the statistical theory of dilution

We investigate the statistical properties of systems with random chemical composition and try to obtain a theoretical derivation of the self-similar Dirichlet distribution, which is used empirically in molecular biology, environmental chemistry, and geochemistry. We consider a system made up of many chemical species and assume that the statistical distribution of the abundance of each chemical species in the system is the result of a succession of a variable number of random dilution events, which can be described by using the renormalization-group theory. A Bayesian approach is used for evaluating the probability density of the chemical composition of the system in terms of the probability densities of the abundances of the different chemical species. We show that for large cascades of dilution events, the probability density of the composition vector of the system is given by a self-similar probability density of the Dirichlet type. We also give an alternative formal derivation for the Dirichlet law based on the maximum entropy approach, by assuming that the average values of the chemical potentials of different species, expressed in terms of molar fractions, are constant. Although the maximum entropy approach leads formally to the Dirichlet distribution, it does not clarify the physical origin of the Dirichlet statistics and has serious limitations. The random theory of dilution provides a physical picture for the emergence of Dirichlet statistics and makes it possible to investigate its validity range. We discuss the implications of our theory in molecular biology, geochemistry, and environmental science.

African Origin of Modern Humans in East Asia: A Tale of 12,000 Y Chromosomes

To test the hypotheses of modern human origin in East Asia, we sampled 12,127 male individuals from 163 populations and typed for three Y chromosome biallelic markers (YAP, M89, and M130). All the individuals carried a mutation at one of the three sites. These three mutations (YAP+, M89T, and M130T) coalesce to another mutation (M168T), which originated in Africa about 35,000 to 89,000 years ago. Therefore, the data do not support even a minimal in situ hominid contribution in the origin of anatomically modern humans in East Asia.

3rd International Meeting on Single Nucleotide Polymorphism and Complex Genome Analysis: SNPs: 'some notable progress'

Fervent activities for the collection and exploitation of single nucleotide polymorphism (SNP) data continue, amid concerns about their real utility. The desire to understand complex disease aetiology remains a key driving force for this activity. Recent developments provided a level of cautious optimism not seen in previous International Meetings on Single Nucleotide Polymorphism and Complex Genome Analysis. The 3rd such meeting, held 8-11 September 2000 in Taos, New Mexico, covered research on technologies for SNP scoring, analytical tools for using SNPs to map disease genes, examples from researchers using SNPs for specific disease studies, and databases and tools for facilitating these activities. Studies of human history, and a range of studies upon model organisms were also represented. Whilst the transition from technology oriented work (methods, discovery, etc.) to successful biological application is occurring relatively slowly, a clear trend in this direction is now apparent, and it will surely gain momentum in future months and years. Many fundamental properties of SNPs remain unknown, and many other basic questions are still unanswered, but the field is moving forward on all necessary fronts, promising exciting advances just around the corner.

Mutational analyses of BRCA1 and BRCA2 in Ashkenazi and non-Ashkenazi Jewish women with familial breast and ovarian cancer

In Ashkenazi (East European) Jews, three predominant mutations in BRCA1 (185delAG and 5382insC) and BRCA2 (6174delT) account for the majority of germline mutations in high-risk breast and/or ovarian cancer families. Among non-Ashkenazi Jews, the 185delAG, Tyr978Ter, and a handful of "private" mutations have been reported anecdotally within both genes. In this study we attempted to determine the spectrum of BRCA1 and BRCA2 mutations in high-risk Jewish individuals, non-carriers of any of the predominant Jewish mutations. We employed multiplex PCR and denaturing gradient gel electrophoresis (DGGE) analysis for BRCA2, and combined denaturing high performance liquid chromatography (DHPLC) and protein truncation test (PTT) for BRCA1, complemented by DNA sequencing. We screened 47 high-risk Jewish individuals, 26 Ashkenazis, and 21 non-Ashkenazis. Overall, 13 sequence alterations in BRCA1 and eight in BRCA2 were detected: nine neutral polymorphisms and 12 missense mutations, including five novel ones. The novel missense mutations did not co-segregate with disease in BRCA1 and were detected at rates of 6.25% to 52.5% in the general population for BRCA2. Our findings suggest that except for the predominant mutations in BRCA1 and BRCA2 in Jewish individuals, there are only a handful of pathogenic mutations within these genes. It may imply novel genes may underlie inherited susceptibility to breast/ovarian cancer in Jewish individuals.

Polynesian origins: insights from the Y chromosome

The question surrounding the colonization of Polynesia has remained controversial. Two hypotheses, one postulating Taiwan as the putative homeland and the other asserting a Melanesian origin of the Polynesian people, have received considerable attention. In this work, we present haplotype data based on the distribution of 19 biallelic polymorphisms on the Y chromosome in a sample of 551 male individuals from 36 populations living in Southeast Asia, Taiwan, Micronesia, Melanesia, and Polynesia. Surprisingly, nearly none of the Taiwanese Y haplotypes were found in Micronesia and Polynesia. Likewise, a Melanesian-specific haplotype was not found among the Polynesians. However, all of the Polynesian, Micronesian, and Taiwanese haplotypes are present in the extant Southeast Asian populations. Evidently, the Y-chromosome data do not lend support to either of the prevailing hypotheses. Rather, we postulate that Southeast Asia provided a genetic source for two independent migrations, one toward Taiwan and the other toward Polynesia through island Southeast Asia.

Attitude towards prophylactic surgery and effects of genetic counselling in families with BRCA mutations. Austrian Hereditary Breast and Ovarian Cancer Group

The intent of this study was to evaluate the effect that an awareness of being a BRCA1 or BRCA2 mutation carrier has on the attitude towards prophylactic surgery and on developing depression symptoms. Thirty-five families were selected on the basis of previously detected BRCA1 or 2 mutations and 90 family members were given the appropriate questionnaires. Prophylactic mastectomy (PM) was considered by 21% of the Austrian mutation carriers (29% affected and 8% non-affected carriers). The majority of affected and non-affected carriers expected PM to impair the quality of their life. Fifty per cent would undergo prophylactic oophorectomy (53% affected and 46% non-affected carriers). The self-rating depression scale indicated that following mutation result disclosure the depression scores of carriers decreased (40 baseline vs 38 after result disclosure, P = 0.3), whereas, for non-carriers, scores increased (36 baseline vs 40 after result disclosure, P = 0.05). We conclude that information about carrier status is not associated with increased depression symptoms in mutation carriers. In non-carriers, depression scores increased slightly, probably reflecting survivor guilt. The option of having PM was associated with a negative impact on the quality of life and was declined by the majority of Austrian mutation carriers.

Denaturing high-performance liquid chromatography detects reliably BRCA1 and BRCA2 mutations

Denaturing high-performance liquid chromatography (DHPLC) is a recently developed method of comparative sequencing based upon heteroduplex detection. To assess the reliability of this method, 180 different mutations (54 deletions, 12 insertions, and 117 single base substitutions) in BRCA1 and BRCA2 were tested. Second, 25 index individuals with complete DHPLC analysis of BRCA1 were reanalyzed by dye-terminator sequencing. Third, 41 index individuals were analyzed concomitantly by both DGGE and DHPLC. Of the 180 different BRCA1 and BRCA2 mutations, 179 showed heterozygous DHPLC elution profiles. Dye-terminator sequencing of the entire BRCA1 gene, including 5592 bp of coding sequence and 5206 bp of flanking noncoding sequence, in 25 index individuals did not reveal additional variants missed by DHPLC. The concomitant analysis of 41 index cases showed that 4 probably disease-associated mutations were identified by DHPLC while only 3 of those 4 sites were detected by denaturing gradient gel electrophoresis. We conclude that DHPLC is a sensitive and cost-effective method for the screening of BRCA1 and BRCA2.

Y-Chromosome evidence for a northward migration of modern humans into Eastern Asia during the last Ice Age

The timing and nature of the arrival and the subsequent expansion of modern humans into eastern Asia remains controversial. Using Y-chromosome biallelic markers, we investigated the ancient human-migration patterns in eastern Asia. Our data indicate that southern populations in eastern Asia are much more polymorphic than northern populations, which have only a subset of the southern haplotypes. This pattern indicates that the first settlement of modern humans in eastern Asia occurred in mainland Southeast Asia during the last Ice Age, coinciding with the absence of human fossils in eastern Asia, 50,000-100,000 years ago. After the initial peopling, a great northward migration extended into northern China and Siberia.

Global sequence diversity of BRCA2: analysis of 71 breast cancer families and 95 control individuals of worldwide populations

The aim of this study was to evaluate the prevalence of simple sequence variation in the BRCA2 gene. To this end, 71 breast and breast-ovarian cancer (HBC/HBOC) families along with 95 control individuals from a wide range of ethnicities were analyzed by means of denaturing high-performance liquid chromatography (DHPLC) and direct sequence analysis. In the coding (10 257 bp) and non-coding (2799 bp) sequences of BRCA2, 82 sequence variants were identified. Three different, apparently disease-associated BRCA2 mutations were found in six HBC/HBOC families (8%): two splice site mutations in introns 5 and 21, and one frameshift mutation in exon 11. In the coding region, 53 simple sequence variants were found: 35 missense mutations, one 2 bp deletion (CT) resulting in a stop at codon 3364, one nonsense mutation with a stop at codon 3326, one deletion of a complete codon (AAA) resulting in the loss of leucine, and 15 silent mutations. In the non-coding region, 26 polymorphisms were detected. Of the 79 sequence variants that were not obviously disease-associated, eight were detected only in HBC/HBOC families. The remaining 71 variants were identified in both HBC/HBOC families and control individuals. Sixty three sequence variants (80%) were specific for a continent. Forty two percent (33 out of 79) of the sequence variants were detected exclusively in Africa, though only 13% of the 332 chromosomes screened were of African origin. Our data indicate that, in BRCA2, simple sequence variation is frequent [in the coding region 1 in 194 bp (straight theta = 2.2 x 10(-4)), and in the non-coding region 1 in 108 bp (straight theta = 4.4 x 10(-4)), respectively].

BRCA1-related breast cancer in Austrian breast and ovarian cancer families: specific BRCA1 mutations and pathological characteristics

We identified 17 BRCA1 mutations in 86 Austrian breast and ovarian cancer families (20%) that were screened for mutations by denaturing high-performance liquid chromatography (DHPLC) and the protein truncation test (PTT). Eleven distinct mutations were detected, 4 of them (962del4, 2795del4, 3135del4 and L3376stop) not previously reported in families of non-Austrian origin. In addition, 6 rare missense mutations (allele frequency < 1%) with unknown biological effects were identified. Four mutations occurred more than once in the Austrian population: 2795del4 (3 times), Cys61Gly (3 times) 5382insC (2 times) and Q1806stop (2 times). Haplotype analysis of the 4 recurrent mutations suggested a common ancestor for each of these. Thirty-four breast cancer cases from 17 families with BRCA1 mutations were further analyzed. We observed a low median age of onset (39.5 years). Sixty-eight percent of all BRCA1 breast cancer cases had negative axillary lymph nodes. This group showed a significant prevalence of a negative estrogen and progesterone receptor status and stage I tumors compared with an age-related, node-negative control group. The prevalence of grade III tumors was marginally significant. Survival analysis either with a control group matched for age (within 5 years), grade, histologic subtype and estrogen receptor status, or with an age-related, node-negative comparison group, showed no statistical difference.

Capillary zone electrophoresis of p-aminobenzoic acid derivatives of aldoses, ketoses and uronic acids

Aldoses, ketoses and uronic acids were derivatized with p-aminobenzoic acid and separated as their borate complexes by capillary zone electrophoresis, using a capillary tube of fused silica containing 150 mM borate buffer, pH 10.0, as carrier. The electrophoretic mobilities of 22 carbohydrates were determined and found to increase with increasing stability of the borate complexes formed. Besides the number of hydroxyl groups and the presence of substituents, complex stability depended most strongly on the configuration of the three vicinal hydroxyl groups at C2, C3 and C4. On-column UV monitoring at 285 nm allowed the detection of glucose with a lower mass detection limit of 15 fmol and a concentration sensitivity of 4 microM. Reproducible quantification of carbohydrates was achieved at least in the concentration range of 0.1-10 mM in reaction solutions by the relative peak area method, using cinnamic acid as internal standard. The method was applied successfully to the determination of the monosaccharide composition of polysaccharides extracted from Radix althaeae.