Pre-emptive iron supplementation prevents myocardial iron deficiency and attenuates adverse remodelling after myocardial infarction.

AIMS: Heart failure (HF) after myocardial infarction (MI) is a major cause of morbidity and mortality. We sought to investigate the functional importance of cardiac iron status after MI and the potential of pre-emptive iron supplementation in preventing cardiac iron deficiency (ID) and attenuating left ventricular (LV) remodelling. METHODS AND RESULTS: MI was induced in C57BL/6J male mice by left anterior descending coronary artery ligation. Cardiac iron status in the non-infarcted LV myocardium was dynamically regulated after MI: non-haem iron and ferritin increased at 4 weeks but decreased at 24 weeks after MI. Cardiac ID at 24 weeks was associated with reduced expression of iron-dependent electron transport chain (ETC) Complex I compared with sham-operated mice. Hepcidin expression in the non-infarcted LV myocardium was elevated at 4 weeks and suppressed at 24 weeks. Hepcidin suppression at 24 weeks was accompanied by more abundant expression of membrane-localized ferroportin, the iron exporter, in the non-infarcted LV myocardium. Notably, similarly dysregulated iron homeostasis was observed in LV myocardium from failing human hearts, which displayed lower iron content, reduced hepcidin expression, and increased membrane-bound ferroportin. Injecting ferric carboxymaltose (15 µg/g body weight) intravenously at 12, 16, and 20 weeks after MI preserved cardiac iron content and attenuated LV remodelling and dysfunction at 24 weeks compared with saline-injected mice. CONCLUSION: We demonstrate, for the first time, that dynamic changes in cardiac iron status after MI are associated with local hepcidin suppression, leading to cardiac ID long term after MI. Pre-emptive iron supplementation maintained cardiac iron content and attenuated adverse remodelling after MI. Our results identify the spontaneous development of cardiac ID as a novel disease mechanism and therapeutic target in post-infarction LV remodelling and HF.

Pulmonary thromboembolism and obesity in forensic pathologic case work.

328 autopsy cases of fatal pulmonary thromboembolism (PE) were compared to 984 age- and sex-matched controls to evaluate the association between obesity and PE in a forensic context. Both PE and control cases had a mean age of 67,8 years (male 62,9 years, females 71,7 years). The percentage of morbidly obese persons with a body mass index (BMI) of above 40 or abdominal subcutaneous adipose tissue of above 4 cm was higher in the PE group (8,39% vs. 4,67% and 29.45% vs. 23.40%, respectively). On the other side, that of very slim persons (BMI below 18.5 or adipose tissue below 3 cm) was significantly smaller (4,27% vs. 7,52% and 47.55% vs. 56,60%). We thus found a strong association between being overweight and death from PE, while slim persons seem to be at an advantage. As the group of underweight persons includes those suffering from chronic diseases with reduced mobility or hypercoagulability (e.g. tumor kachexia or sarkopenia due to immobilisation), this finding is to some extent unexpected.

Age-Related DNA Methylation in Normal Kidney Tissue Identifies Epigenetic Cancer Risk Susceptibility Loci in the ANKRD34B and ZIC1 Genes.

Both age-dependent and age-independent alteration of DNA methylation in human tissues are functionally associated with the development of many malignant and non-malignant human diseases. TCGA-KIRC data were biometrically analyzed to identify new loci with age-dependent DNA methylation that may contribute to tumor risk in normal kidney tissue. ANKRD34B and ZIC1 were evaluated as candidate genes by pyrosequencing of 539 tissues, including 239 normal autopsy, 157 histopathologically tumor-adjacent normal, and 143 paired tumor kidney samples. All candidate CpG loci demonstrated a strong correlation between relative methylation levels and age (R = 0.70−0.88, p < 2 × 10−16) and seven out of 10 loci were capable of predicting chronological age in normal kidney tissues, explaining 84% of the variance (R = 0.92). Moreover, significantly increased age-independent methylation was found for 9 out of 10 CpG loci in tumor-adjacent tissues, compared to normal autopsy tissues (p = 0.001−0.028). Comparing tumor and paired tumor-adjacent tissues revealed two patient clusters showing hypermethylation, one cluster without significant changes in methylation, and a smaller cluster demonstrating hypomethylation in the tumors (p < 1 × 10−10). Taken together, our results show the presence of additional methylation risk factors besides age for renal cancer in normal kidney tissue. Concurrent tumor-specific hypermethylation suggests a subset of these loci are candidates for epigenetic renal cancer susceptibility.

Detection of pharmaceuticals in "dirty sprite" using gas chromatography and mass spectrometry.

Dirty Sprite, also known as "lean" or "purple drank", is a preparation associated with the presence of codeine and promethazine. These drinks, predominantly used by young people, are mixtures of, for example, soft drinks, prescription medicines, and prescription cough syrups. The use of these illicit preparations started in Texas in the 1960s and become popularized in the 1990s. However, the misuse of these cocktails has become more common in other countries to date, for example, in Thailand. Given the illicit nature of these preparations and the lack of information available on the composition of these products, there is a need to identify and quantify the drugs that may be present. Three samples of Dirty Sprite were analyzed using GC-MS after liquid/liquid-extraction under acidic and basic conditions. Since the acidic extraction did not show the detection of relevant substances, samples were alkalized to pH ≥ 9, followed by extraction with 1-chlorobutane. GC-MS screening revealed the identification of codeine, dihydrocodeine, promethazine and impurities of cocaine. A selected ion monitoring method was developed for the quantification of these compounds using lemonade as a calibration matrix. Quantitative analysis showed concentrations of 130-mg/L codeine, 75-mg/L promethazine, and 3.4-mg/L cocaine in sample 1; 74-mg/L promethazine and 91-mg/L dihydrocodeine in sample 2; and 130-mg/L codeine combined with 68-mg/L promethazine in sample 3. The results also illustrate that the consumption of drugs detected in Dirty Sprite samples could lead to health risks given that these prescription medicines are consumed outside the medical environment.

Age-, tumor-, and metastatic tissue-associated DNA hypermethylation of a T-box brain 1 locus in human kidney tissue.

BACKGROUND: While a considerable number of tumor-specific hypermethylated loci have been identified in renal cell cancer (RCC), DNA methylation of loci showing successive increases in normal, tumoral, and metastatic tissues could point to genes with high relevance both for the process of tumor development and progression. Here, we report that DNA methylation of a locus in a genomic region corresponding to the 3'UTR of the transcription factor T-box brain 1 (TBR1) mRNA accumulates in normal renal tissues with age and possibly increased body mass index. Moreover, a further tissue-specific increase of methylation was observed for tumor and metastatic tissue samples. RESULTS: Biometric analyses of the TCGA KIRC methylation data revealed candidate loci for age-dependent and tumor-specific DNA methylation within the last exon and in a genomic region corresponding to the 3'UTR TBR1 mRNA. To evaluate whether methylation of TBR1 shows association with RCC carcinogenesis, we measured 15 tumor cell lines and 907 renal tissue samples including 355 normal tissues, 175 tissue pairs of normal tumor adjacent and corresponding tumor tissue as well 202 metastatic tissues samples of lung, bone, and brain metastases by the use of pyrosequencing. Statistical evaluation demonstrated age-dependent methylation in normal tissue (R = 0.72, p < 2 × 10-16), association with adiposity (P = 0.019) and tumor-specific hypermethylation (P = 6.1 × 10-19) for RCC tissues. Comparison of tumor and metastatic tissues revealed higher methylation in renal cancer metastases (P = 2.65 × 10-6). CONCLUSIONS: Our analyses provide statistical evidence of association between methylation of TBR1 and RCC development and disease progression.

Heparan Sulfate-Editing Extracellular Sulfatases Enhance VEGF Bioavailability for Ischemic Heart Repair.

RATIONALE: Mechanistic insight into the inflammatory response after acute myocardial infarction may inform new molecularly targeted treatment strategies to prevent chronic heart failure. OBJECTIVE: We identified the sulfatase SULF2 in an in silico secretome analysis in bone marrow cells from patients with acute myocardial infarction and detected increased sulfatase activity in myocardial autopsy samples. SULF2 (Sulf2 in mice) and its isoform SULF1 (Sulf1) act as endosulfatases removing 6-O-sulfate groups from heparan sulfate (HS) in the extracellular space, thus eliminating docking sites for HS-binding proteins. We hypothesized that the Sulfs have a role in tissue repair after myocardial infarction. METHODS AND RESULTS: Both Sulfs were dynamically upregulated after coronary artery ligation in mice, attaining peak expression and activity levels during the first week after injury. Sulf2 was expressed by monocytes and macrophages, Sulf1 by endothelial cells and fibroblasts. Infarct border zone capillarization was impaired, scar size increased, and cardiac dysfunction more pronounced in mice with a genetic deletion of either Sulf1 or Sulf2. Studies in bone marrow-chimeric Sulf-deficient mice and Sulf-deficient cardiac endothelial cells established that inflammatory cell-derived Sulf2 and endothelial cell-autonomous Sulf1 promote angiogenesis. Mechanistically, both Sulfs reduced HS sulfation in the infarcted myocardium, thereby diminishing Vegfa (vascular endothelial growth factor A) interaction with HS. Along this line, both Sulfs rendered infarcted mouse heart explants responsive to the angiogenic effects of HS-binding Vegfa164 but did not modulate the angiogenic effects of non-HS-binding Vegfa120. Treating wild-type mice systemically with the small molecule HS-antagonist surfen (bis-2-methyl-4-amino-quinolyl-6-carbamide, 1 mg/kg/day) for 7 days after myocardial infarction released Vegfa from HS, enhanced infarct border-zone capillarization, and exerted sustained beneficial effects on cardiac function and survival. CONCLUSIONS: These findings establish HS-editing Sulfs as critical inducers of postinfarction angiogenesis and identify HS sulfation as a therapeutic target for ischemic tissue repair.

Evidence for an association of interferon gene variants with sudden infant death syndrome.

BACKGROUND: There is evidence that inflammation plays a role in the etiology of sudden infant death syndrome (SIDS). Immune system dysregulation seems to be the background of higher infection susceptibility in SIDS infants. This phenotype is possibly determined by genetic factors. METHODS: Twenty-three single nucleotide polymorphisms (SNPs) in the following 13 candidate genes governing the immune system were successfully genotyped in 251 Caucasian SIDS cases and 336 controls from Germany: ADAR1, CSF2RB, DDX58, IFNA1, IFNA21, IFNA8, IFNAR2, IFNG, IL6, MX2, OAS1, OAS3, and TNFA. Associations between genotypes and SIDS were then statistically evaluated using logistic regression analyses. RESULTS: Overall analysis revealed statistically significant results for two variants in interferon gamma (IFNG) (rs2069705: OR 1.40 (1.07; 1.83), p = 0.01; and rs2069727: OR 0.75 (0.59; 0.96), p = 0.02) and for one variant in interferon alpha 8 (IFNA8) (rs1330321: OR 1.85 (1.06; 3.21), p = 0.03). Haplotype analyses identified a three-marker risk IFNG haplotype rs2069727-rs2069718-rs2069705 associated with SIDS (OR = 1.62, 95% CI 1.23-2.13; p = 0.0003). Subgroup associations were found for variants in adenosine deaminase acting on RNA1 (ADAR1), 2',5'-oligoadenylate synthetase-1 (OAS1) and colony stimulating factor 2 receptor beta common subunit (CSF2RB). CONCLUSION: In summary, this large study of 251 SIDS cases for common variants in 13 candidate genes governing the immune system has provided first evidence for a role of IFNG in the etiology of SIDS and should stimulate further research into the clinicopathological relevance of immunomodulatory genes for this fatal syndrome.

EMC10 (Endoplasmic Reticulum Membrane Protein Complex Subunit 10) Is a Bone Marrow-Derived Angiogenic Growth Factor Promoting Tissue Repair After Myocardial Infarction.

BACKGROUND: Clinical trials of bone marrow cell-based therapies after acute myocardial infarction (MI) have produced mostly neutral results. Treatment with specific bone marrow cell-derived secreted proteins may provide an alternative biological approach to improving tissue repair and heart function after MI. We recently performed a bioinformatic secretome analysis in bone marrow cells from patients with acute MI and discovered a poorly characterized secreted protein, EMC10 (endoplasmic reticulum membrane protein complex subunit 10), showing activity in an angiogenic screen. METHODS: We investigated the angiogenic potential of EMC10 and its mouse homolog (Emc10) in cultured endothelial cells and infarcted heart explants. We defined the cellular sources and function of Emc10 after MI using wild-type, Emc10-deficient, and Emc10 bone marrow-chimeric mice subjected to transient coronary artery ligation. Furthermore, we explored the therapeutic potential of recombinant Emc10 delivered by osmotic minipumps after MI in heart failure-prone FVB/N mice. RESULTS: Emc10 signaled through small GTPases, p21-activated kinase, and the p38 mitogen-activated protein kinase (MAPK)-MAPK-activated protein kinase 2 (MK2) pathway to promote actin polymerization and endothelial cell migration. Confirming the importance of these signaling events in the context of acute MI, Emc10 stimulated endothelial cell outgrowth from infarcted mouse heart explants via p38 MAPK-MK2. Emc10 protein abundance was increased in the infarcted region of the left ventricle and in the circulation of wild-type mice after MI. Emc10 expression was also increased in left ventricular tissue samples from patients with acute MI. Bone marrow-derived monocytes and macrophages were the predominant sources of Emc10 in the infarcted murine heart. Emc10 KO mice showed no cardiovascular phenotype at baseline. After MI, however, capillarization of the infarct border zone was impaired in KO mice, and the animals developed larger infarct scars and more pronounced left ventricular remodeling compared with wild-type mice. Transplanting KO mice with wild-type bone marrow cells rescued the angiogenic defect and ameliorated left ventricular remodeling. Treating FVB/N mice with recombinant Emc10 enhanced infarct border-zone capillarization and exerted a sustained beneficial effect on left ventricular remodeling. CONCLUSIONS: We have identified Emc10 as a previously unknown angiogenic growth factor that is produced by bone marrow-derived monocytes and macrophages as part of an endogenous adaptive response that can be enhanced therapeutically to repair the heart after MI.

Candidate gene variants of the immune system and sudden infant death syndrome.

BACKGROUND: Sudden infant death syndrome (SIDS) causes early infant death with an incidence between 0.5 and 2.5 cases among 1000 live births. Besides central sleep apnea and thermal dysregulation, infections have been repeatedly suggested to be implicated in SIDS etiology. METHODS: To test the risk contribution of common genetic variants related to infection, we genotyped 40 single-nucleotide polymorphisms (SNPs) from 15 candidate genes for association with SIDS in a total of 579 cases and 1124 controls from Germany and the UK in a two-stage case control design. RESULTS: The discovery-stage series (267 SIDS cases and 303 controls) revealed nominally significant associations for variants in interleukin 6 (IL6) (rs1880243), interleukin 10 (IL10) (rs1800871, rs1800872), and mannose-binding lectin 2 (MBL2) (rs930506), and for several other variants in subgroups. Meta-analyses were then performed in adding genotype information from a genome-wide association study of another 312 European SIDS cases and 821 controls. Overall associations were observed for two independent variants in MBL2: rs930506 in a co-dominant model (odds ratio (OR) = 0.82, p = 0.04) and rs1838065 in a dominant model (OR = 1.27, p = 0.03). CONCLUSION: Our study did not replicate published associations of IL10 variants with SIDS. However, the evidence for two independent MBL2 variants in the combined analysis of two large series seems consistent with the hypothesis that infection may play a role in SIDS pathogenesis.

Doublesex and mab-3 related transcription factor 1 (DMRT1) is a sex-specific genetic determinant of childhood-onset asthma and is expressed in testis and macrophages.

BACKGROUND: Asthma is a disease affecting more boys than girls in childhood and more women than men in adulthood. The mechanisms behind these sex-specific differences are not yet understood. OBJECTIVE: We analyzed whether and how genetic factors contribute to sex-specific predisposition to childhood-onset asthma. METHODS: Interactions between sex and polymorphisms on childhood asthma risk were evaluated in the Multicentre Asthma Genetics in Childhood Study (MAGICS)/Phase II International Study of Asthma and Allergies in Childhood (ISAAC II) population on a genome-wide level, and findings were validated in independent populations. Genetic fine mapping of sex-specific asthma association signals was performed, and putatively causal polymorphisms were characterized in vitro by using electrophoretic mobility shift and luciferase activity assays. Gene and protein expression of the identified gene doublesex and mab-3 related transcription factor 1 (DMRT1) were measured in different human tissues by using quantitative real-time PCR and immunohistochemistry. RESULTS: Polymorphisms in the testis-associated gene DMRT1 displayed interactions with sex on asthma status in a population of primarily clinically defined asthmatic children and nonasthmatic control subjects (lowest P = 5.21 × 10(-6)). Replication of this interaction was successful in 2 childhood populations clinically assessed for asthma but showed heterogeneous results in other population-based samples. Polymorphism rs3812523 located in the putative DMRT1 promoter was associated with allele-specific changes in transcription factor binding and promoter activity in vitro. DMRT1 expression was observed not only in the testis but also in lung macrophages. CONCLUSION: DMRT1 might influence sex-specific patterns of childhood asthma, and its expression in testis tissue and lung macrophages suggests a potential involvement in hormone or immune cell regulation.

Are porcine flexor digitorum profundus tendons suitable graft substitutes for human hamstring tendons in biomechanical in vitro-studies?

INTRODUCTION: Although a plenty of studies exist assessing the strength of ligamentous fixation techniques using porcine flexor digitorum profundus tendons as graft substitutes for human hamstring tendons, there is no biomechanical study comparing these two tendons. To interpret the results obtained with porcine flexor digitorum profundus tendons, knowledge of their biomechanical properties is essential. The purpose of this study was to compare the biomechanical properties of human hamstring tendons and porcine flexor digitorum profundus tendons. MATERIALS AND METHODS: A total of six human hamstring tendons and six porcine flexor digitorum profundus tendons were analysed in this study. Quadruple-bundle human hamstring tendons and double-bundle porcine flexor digitorum profundus tendons with a diameter of 9 mm were used. Specimens were placed into a tensile loading fixation of a servohydraulic testing machine. Biomechanical analysis included pretensioning of the constructs at 50 N for 10 min following cyclic loading of 1500 cycles between 50 and 200 N at 0.5 Hz for measurement of elongation. Subsequently, ultimate failure load and failure mode analysis were performed with a ramp speed of 20 mm/min. RESULTS: Human hamstring tendons showed significantly higher maximum load to failure values compared to porcine flexor digitorum profundus tendons (1597 ± 179.6 N vs. 1109 ± 101.9 N; p = 0.035). Human hamstring tendons yielded significantly lower initial elongation during preload, but not during cyclical loading. CONCLUSIONS: When porcine flexor digitorum profundus tendons are used as graft substitutes for human hamstring tendons in biomechanical studies, maximum load to failure is underestimated while elongation is comparable to that of human hamstring tendons. Transferring results of biomechanical studies into clinical practice, the lower maximum load to failure of porcine flexor digitorum profundus tendons needs to be taken into consideration.

Whole-exome sequencing identifies mutations of TBC1D1 encoding a Rab-GTPase-activating protein in patients with congenital anomalies of the kidneys and urinary tract (CAKUT).

Congenital anomalies of the kidneys and urinary tract (CAKUT) are genetically highly heterogeneous leaving most cases unclear after mutational analysis of the around 30 causative genes known so far. Assuming that phenotypes frequently showing dominant inheritance, such as CAKUT, can be caused by de novo mutations, de novo analysis of whole-exome sequencing data was done on two patient-parent-trios to identify novel CAKUT genes. In one case, we detected a heterozygous de novo frameshift variant in TBC1D1 encoding a Rab-GTPase-activating protein regulating glucose transporter GLUT4 translocation. Sequence analysis of 100 further CAKUT cases yielded three novel or rare inherited heterozygous TBC1D1 missense variants predicted to be pathogenic. TBC1D1 mutations affected Ser237-phosphorylation or protein stability and thereby act as hypomorphs. Tbc1d1 showed widespread expression in the developing murine urogenital system. A mild CAKUT spectrum phenotype, including anomalies observed in patients carrying TBC1D1 mutations, was found in kidneys of some Tbc1d1 (-/-) mice. Significantly reduced Glut4 levels were detected in kidneys of Tbc1d1 (-/-) mice and the dysplastic kidney of a TBC1D1 mutation carrier versus controls. TBC1D1 and SLC2A4 encoding GLUT4 were highly expressed in human fetal kidney. The patient with the truncating TBC1D1 mutation showed evidence for insulin resistance. These data demonstrate heterozygous deactivating TBC1D1 mutations in CAKUT patients with a similar renal and ureteral phenotype, and provide evidence that TBC1D1 mutations may contribute to CAKUT pathogenesis, possibly via a role in glucose homeostasis.

Germline genetics of the p53 pathway affect longevity in a gender specific manner.

Aging is thought to occur through the accumulation of molecular and cellular damage. A key regulator of the cell's stress response is p53. In mice, the activity of p53 associates with lifespan. We were therefore interested whether SNPs in members of the p53-pathway are associated with longevity in humans. We genotyped the following SNPs: p53 - rs1042522 (Arg72Pro), MDM2 - rs2279744 (SNP309), MDM4 - rs4245739 (SNP34091), rs1563828 (SNP31826), PPP2R2B (rs319217) in 155 long-lived individuals (LLIs) who died at the age of 91 and over and in 171 ethnically-matched control subjects. Kaplan-Meier survival curves and log-Rank-test were used to determine the mean and median survival times. In female LLIs, the Pro-allele of rs1042522 (Arg72Pro) and the G-allele of rs2279744 (SNP309) were significantly associated with an increased survival time (P=0.026, P<0.001, respectively, log-Rank-test). In contrast, there was no difference regarding the survival time in male LLIs (rs1042522: P=0.58, rs2279744: P=0.503, log-Rank-test). There was no difference regarding the average age of death for the genotypes of the respective SNPs in the MDM4 gene (rs1563828: P=0.99; rs4245739: P=0.179, respectively). Here we show for the first time that the G-allele of rs2279744 (SNP309) is associated with increased lifespan. Importantly, this effect is gender-specific. Our data support the hypothesis that genetic variants that are associated with lower activity of p53--and therefore increased tumor risk--are associated with prolonged lifespan in a gender-specific manner.

Association between polymorphisms in the P2RY1 and SSTR2 genes and sudden infant death syndrome.

INTRODUCTION: Sudden infant death syndrome (SIDS) is a multifactorial syndrome and we believe that an inefficient respiratory response to certain homeostatic stressors, such as hypoxia and hypercapnia, is a key factor in the etiology of SIDS. Hence, we genotyped two single nucleotide polymorphisms (SNPs) in genes of importance for respiratory control: P2RY1 (adenosine diphosphate/adenosine triphosphate receptor) and SSTR2 (somatostatin receptor). METHODS: Two SNPs, Rs1466113 (C > G dimorphism in SSTR2) and rs701265 (A > G dimorphism in P2RY1), were typed in 175 SIDS cases and 195 controls and 275 SIDS cases and 338 controls, respectively. Genotyping was performed using TaqMan technology. RESULTS: The determined genotype frequencies were SSTR2: CC (14.4 %), CG (49.7 %), GG (35.9 %) in controls and CC (17.1 %), CG (49.1 %), and GG (33.8 %) in SIDS; P2RY1: AA (70.6 %), AG (28.7 %), GG (0.7 %) in SIDS and AA (68.3 %), AG (27.9 %), and GG (3.8 %) in the control group. For rs701265 in P2RY1, homozygous G carriers were significantly more frequent in the control group (p = 0.02). CONCLUSION: We think that allele G provides a protective effect in events of ventilatory stress. Moreover, the significant lack of P2Y1 G allele homozygotes in the SIDS group shows that respiratory response plays an important role in the etiology of SIDS. Thus, we believe it is worthwhile to further investigate functional polymorphisms within genes that are involved in respiratory control in the future.

A functional polymorphism in the tyrosine hydroxylase gene indicates a role of noradrenalinergic signaling in sudden infant death syndrome.

OBJECTIVES: Catecholamines may contribute to the cause of sudden infant death syndrome (SIDS). TH01, a tetrameric short tandem repeat marker in the tyrosine hydroxylase gene, regulates gene expression and catecholamine production. STUDY DESIGN: We investigated TH01 in 172 German Caucasian SIDS cases and 390 sex- and age-matched control subjects. RESULTS: The *9.3 alleles were more frequent in patients with SIDS than in control subjects (40.12% vs 31.15%; P = .006). For homozygotes the odds ratio was 1.83 (95% confidence interval: 1.09-3.05), for carriers 1.58 (1.09-2.28). Moreover, *9.3 alleles were significantly more frequent during the winter (47.73% vs 35.38% in the warmer seasons), and the frequency of *9.3 alleles varied significantly with the age at death (weeks 7 to 12: 49.04% vs 29.63% within the first 6 weeks). Other risk factors (sleeping position, gestation, smoking) had no significant impact on the frequency of *9.3. CONCLUSIONS: Our results indicate a relationship between SIDS and TH01 genotype, presumably caused by an impairment of breathing regulation or arousal. We propose that noradrenalinergic neuronal activity contributes to the cause of a major subset of SIDS victims. Moreover, the results further stress that SIDS is a highly heterogenic group.

Expression of the epidermal growth factor seven-transmembrane member CD97 correlates with grading and staging in human oral squamous cell carcinomas.

INTRODUCTION: The oral squamous cell carcinoma (OSCC) is the sixth most common malignant tumor worldwide. No significant better progress has been made in the treatment of OSCCs during the last decades. The heterodimeric CD97 protein is a epidermal growth factor seven-transmembrane family member and was identified as a dedifferentiation marker in thyroid carcinomas. Nothing is known about CD97 in OSCCs. MATERIAL AND METHODS: Employing UV-laser microdissection, CD97 and its ligand CD55 were investigated in normal oral mucosa and OSCCs (n = 78) by multiplex reverse transcription-PCR. Frozen sections were investigated by immunohistochemistry. The effects of retinoic acid and sodium butyrate on the CD97/CD55 expression in OSCC cell lines were determined by quantitative PCR, immunocytochemistry, and flow cytometry. RESULTS: Weak CD97 transcripts were expressed in normal mucosa and normal basal epithelial cells revealed specific CD97 immunostaining. Strong CD97 transcripts were detected in pT(3)/T(4) and G3/G4 OSCC tissues, whereas pT(1)/T(2) and G1/G2 carcinomas revealed weak CD97 transcript levels. A weak CD97 immunostaining was observed in pT(1)/T(2) and G1/G2 tumors. By contrast, intensive CD97 immunostaining was detected in pT(3)/T(4) OSCCs and G3/G4 lesions. CD55 gene expression was low in normal mucosa. All OSCCs, irrespective of stage and grading, displayed strong CD55 immunostaining. Sodium butyrate and retinoic acid inhibited CD97 mRNA and protein in OSCC cell lines. Interestingly, CD55 was up-regulated by both substances. CONCLUSION: We identified CD97 as a novel marker of dedifferentiated OSCC. Interaction of CD97 and CD55 may facilitate adhesion of OSCC cells to surrounding surfaces that would result in metastases and bad prognosis.