Low prevalence of male microchimerism in women with Mayer-Rokitansky-Küster-Hauser syndrome.

STUDY QUESTION: Is there an increased prevalence of male microchimerism in women with Mayer-Rokitansky-Küster-Hauser (MRKH) syndrome, as evidence of fetal exposure to blood and anti-Müllerian hormone (AMH) from a (vanished) male co-twin resulting in regression of the Müllerian duct derivatives? SUMMARY ANSWER: Predominant absence of male microchimerism in adult women with MRKH syndrome does not support our hypothesis that intrauterine blood exchange with a (vanished) male co-twin is the pathophysiological mechanism. WHAT IS KNOWN ALREADY: The etiology of MRKH is unclear. Research on the phenotype analogous condition in cattle (freemartinism) has yielded the hypothesis that Müllerian duct development is inhibited by exposure to AMH in utero. In cattle, the male co-twin has been identified as the source for AMH, which is transferred via placental blood exchange. In human twins, a similar exchange of cellular material has been documented by detection of chimerism, but it is unknown whether this has clinical consequences. STUDY DESIGN, SIZE, DURATION: An observational case-control study was performed to compare the presence of male microchimerism in women with MRKH syndrome and control women. Through recruitment via the Dutch patients' association of women with MRKH (comprising 300 members who were informed by email or regular mail), we enrolled 96 patients between January 2017 and July 2017. The control group consisted of 100 women who reported never having been pregnant. PARTICIPANTS/MATERIALS, SETTING, METHODS: After written informed consent, peripheral blood samples were obtained by venipuncture, and genomic DNA was extracted. Male microchimerism was detected by Y-chromosome-specific real-time quantitative PCR, with use of DYS14 marker. Possible other sources for microchimerism, for example older brothers, were evaluated using questionnaire data. MAIN RESULTS AND THE ROLE OF CHANCE: The final analysis included 194 women: 95 women with MRKH syndrome with a mean age of 40.9 years and 99 control women with a mean age of 30.2 years. In total, 54 women (56.8%) were identified as having typical MRKH syndrome, and 41 women (43.2%) were identified as having atypical MRKH syndrome (when extra-genital malformations were present). The prevalence of male microchimerism was significantly higher in the control group than in the MRKH group (17.2% versus 5.3%, P = 0.009). After correcting for age, women in the control group were 5.8 times more likely to have male microchimerism (odds ratio 5.84 (CI 1.59-21.47), P = 0.008). The mean concentration of male microchimerism in the positive samples was 56.0 male genome equivalent per 1 000 000 cells. The prevalence of male microchimerism was similar in women with typical MRKH syndrome and atypical MRKH syndrome (5.6% versus 4.9%, P = 0.884). There were no differences between women with or without microchimerism in occurrence of alternative sources of XY cells, such as older brothers, previous blood transfusion, or history of sexual intercourse. LIMITATIONS, REASON FOR CAUTION: We are not able to draw definitive conclusions regarding the occurrence of AMH exchange during embryologic development in women with MRKH syndrome. Our subject population includes all adult women and therefore is reliant on long-term prevalence of microchimerism. Moreover, we have only tested blood, and, theoretically, the cells may have grafted anywhere in the body during development. It must also be considered that the exchange of AMH may occur without the transfusion of XY cells and therefore cannot be discovered by chimerism detection. WIDER IMPLICATIONS OF THE FINDINGS: This is the first study to test the theory that freemartinism causes the MRKH syndrome in humans. The study aimed to test the presence of male microchimerism in women with MRKH syndrome as a reflection of early fetal exposure to blood and AMH from a male (vanished) co-twin. We found that male microchimerism was only present in 5.3% of the women with MRKH syndrome, a significantly lower percentage than in the control group (17.2%). Our results do not provide evidence for an increased male microchimerism in adult women with MRKH as a product of intrauterine blood exchange. However, the significant difference in favor of the control group is of interest to the ongoing discussion on microchimeric cell transfer and the possible sources of XY cells. STUDY FUNDING/COMPETING INTEREST(S): None. TRIAL REGISTRATION NUMBER: Dutch trial register, NTR5961.

Predicting loneliness with polygenic scores of social, psychological and psychiatric traits.

Loneliness is a heritable trait that accompanies multiple disorders. The association between loneliness and mental health indices may partly be due to inherited biological factors. We constructed polygenic scores for 27 traits related to behavior, cognition and mental health and tested their prediction for self-reported loneliness in a population-based sample of 8798 Dutch individuals. Polygenic scores for major depressive disorder (MDD), schizophrenia and bipolar disorder were significantly associated with loneliness. Of the Big Five personality dimensions, polygenic scores for neuroticism and conscientiousness also significantly predicted loneliness, as did the polygenic scores for subjective well-being, tiredness and self-rated health. When including all polygenic scores simultaneously into one model, only 2 major depression polygenic scores remained as significant predictors of loneliness. When controlling only for these 2 MDD polygenic scores, only neuroticism and schizophrenia remain significant. The total variation explained by all polygenic scores collectively was 1.7%. The association between the propensity to feel lonely and the susceptibility to psychiatric disorders thus pointed to a shared genetic etiology. The predictive power of polygenic scores will increase as the power of the genome-wide association studies on which they are based increases and may lead to clinically useful polygenic scores that can inform on the genetic predisposition to loneliness and mental health.

Pre-hospital pelvic girdle injury: Improving diagnostic accuracy in a physician-led trauma service.

BACKGROUND: Examination of missed injuries in our physician-led pre-hospital trauma service indicated that the significant injuries missed were often pelvic fractures. We therefore conducted a study whose aim was to evaluate the pre-hospital diagnostic accuracy of pelvic girdle injuries, and how this would be affected by implementing the pelvic injury treatment guidelines recently published by the Faculty of Pre-Hospital Care. STUDY DESIGN: All blunt trauma patients attended in a 5-month period were included in the study. The presence or absence of pelvic girdle injury on computed tomography (CT) or, if unavailable, pelvic X-ray was used as a primary outcome measure. A retrospective database and case note review was conducted to identify patients who had pelvic binder applied in the study period. For the purposes of the study, pelvic ring and acetabular fractures were grouped together as patients with suspected pelvic girdle injury that should be fitted with a pelvic binder in the pre-hospital setting. The sensitivity and specificity, relating to the presence of pelvic girdle injury in patients with pelvic binders, was calculated in order to determine pre-hospital diagnostic accuracy. RESULTS: 785 patients were attended during the study period. 170 met the study inclusion criteria. 26 (15.3%) sustained a pelvic girdle injury. 45 (26.5%) had a pelvic binder applied. There were eight missed fractures (31%), of which the majority (six) sustained less severe injuries that were managed non-operatively. Two patients required operative fixation. Radiological images and/or reports were available on 169 (99.4%) patients. As a test of the presence of pelvic fracture, pelvic binder application had a sensitivity of 0.69 (95% CI 0.50-0.85) and a specificity of 0.81 (95% CI 0.74-0.87). CONCLUSIONS: Even with a careful clinical assessment and a low threshold for binder application, this study highlights the problems of distracting injury when trying to diagnose and manage pelvic fractures. By implementing the pelvic treatment guidelines published by the Faculty of Pre-hospital Care, the missed injury rate could be reduced from 31% to 8%.

Minimally invasive genomic and transcriptomic profiling of visceral cancers by next-generation sequencing of circulating exosomes.

BACKGROUND: The ability to perform comprehensive profiling of cancers at high resolution is essential for precision medicine. Liquid biopsies using shed exosomes provide high-quality nucleic acids to obtain molecular characterization, which may be especially useful for visceral cancers that are not amenable to routine biopsies. PATIENTS AND METHODS: We isolated shed exosomes in biofluids from three patients with pancreaticobiliary cancers (two pancreatic, one ampullary). We performed comprehensive profiling of exoDNA and exoRNA by whole genome, exome and transcriptome sequencing using the Illumina HiSeq 2500 sequencer. We assessed the feasibility of calling copy number events, detecting mutational signatures and identifying potentially actionable mutations in exoDNA sequencing data, as well as expressed point mutations and gene fusions in exoRNA sequencing data. RESULTS: Whole-exome sequencing resulted in 95%-99% of the target regions covered at a mean depth of 133-490×. Genome-wide copy number profiles, and high estimates of tumor fractions (ranging from 56% to 82%), suggest robust representation of the tumor DNA within the shed exosomal compartment. Multiple actionable mutations, including alterations in NOTCH1 and BRCA2, were found in patient exoDNA samples. Further, RNA sequencing of shed exosomes identified the presence of expressed fusion genes, representing an avenue for elucidation of tumor neoantigens. CONCLUSIONS: We have demonstrated high-resolution profiling of the genomic and transcriptomic landscapes of visceral cancers. A wide range of cancer-derived biomarkers could be detected within the nucleic acid cargo of shed exosomes, including copy number profiles, point mutations, insertions, deletions, gene fusions and mutational signatures. Liquid biopsies using shed exosomes has the potential to be used as a clinical tool for cancer diagnosis, therapeutic stratification and treatment monitoring, precluding the need for direct tumor sampling.

Advanced airway management is necessary in prehospital trauma patients.

BACKGROUND: Treatment of airway compromise in trauma patients is a priority. Basic airway management is provided by all emergency personnel, but the requirement for on-scene advanced airway management is controversial. We attempted to establish the demand for on-scene advanced airway interventions. Trauma patients managed with standard UK paramedic airway interventions were assessed to determine whether airway compromise had been effectively treated or whether more advanced airway management was required. METHODS: A prospective observational study was conducted to identify trauma patients requiring prehospital advanced airway management attended by a doctor-paramedic team. The team assessed and documented airway compromise on arrival, interventions performed before and after their arrival, and their impact on airway compromise. RESULTS: Four hundred and seventy-two patients required advanced airway intervention and received 925 airway interventions by ground-based paramedics. Two hundred and sixty-nine patients (57%) still had airway compromise on arrival of the enhanced care team; no oxygen had been administered to 52 patients (11%). There were 45 attempted intubations by ground paramedics with a 64% success rate and 11% unrecognized oesophageal intubation rate. Doctor-paramedic teams delivering prehospital anaesthesia achieved definitive airway management for all patients. CONCLUSIONS: A significant proportion of severely injured trauma patients required advanced airway interventions to effectively treat airway compromise. Standard ambulance service interventions were only effective for a proportion of patients, but might not have always been applied appropriately. Complications of advanced airway management occurred in both provider groups, but failed intubation and unrecognized oesophageal intubation were a particular problem in the paramedic intubation group.

Identification and functional characterization of three novel alleles for the serotonin transporter-linked polymorphic region.

A promoter polymorphism in the serotonin transporter gene (5-HTTLPR) has been reported to confer relative risk for phenotypes (depression/anxiety) and endophenotypes (amygdala reactivity). In this report, we identify and characterize three rare 5-HTTLPR alleles not previously described in the human literature. The three novel alleles were identified while genotyping 5-HTTLPR in a family-based attention deficit hyperactivity disorder clinical population. Two of the novel alleles are longer than the common 16-repeat long (L) allele (17 and 18 repeats) and the third is significantly smaller than the 14-repeat short (S) allele (11 repeats). The sequence and genetic architecture of each novel allele is described in detail. We report a significant decrease in the expression between the XL17 (17r) allele and the L(A) (16r) allele. The XS11 (11r) allele showed similar expression with the S (14r) allele. A 1.8-fold increase in expression was observed with the L(A)(16r) allele compared with the L(G) (16r) allele, which replicates results from earlier 5-HTTLPR expression experiments. In addition, transcription factor binding site (TFBS) analysis was performed using MatInspector (Genomatix) that showed the presence or absence of different putative TFBSs between the novel alleles and the common L (16r) and S (14r) alleles. The identification of rare variants and elucidation of their functional impact could potentially lead to understanding the contribution that the rare variant may have on the inheritance/susceptibility of multifactorial common diseases.

Berberine and evodiamine influence serotonin transporter (5-HTT) expression via the 5-HTT-linked polymorphic region.

The aim of this study was to investigate the effect of berberine and evodiamine on serotonin transporter (5-HTT) expression and then test how allelic variations previously identified in the promoter region could modulate that effect in the serotonergic neuronal cell line RN46A. Both berberine and evodiamine, alone and in combination, increased 5-HTT mRNA and protein expression significantly across the various alleles. When tested against the S, XS(11), L(G), L(A), XL(17), and XL(18) alleles, respectively, 100 µM berberine increased 5-HTT promoter activities by 67%, 128.7%, 106.9%, 100.4%, 26.2% and 82%, 2 µM evodiamine increased 5-HTT promoter activities by 216.7%, 81.6%, 305.6%, 181.5%, 175.3% and 102.2%. Berberine and evodiamine increased 5-HTT promoter activity differently depending on the genetic variation of the 5-HTTLPR polymorphism. This study has provided a convincing example of how herbal compounds influence the expression of one of the most intensively studied psychiatric candidate genes, the serotonin transporter.

Berberine increases expression of GATA-2 and GATA-3 during inhibition of adipocyte differentiation.

It is known that a number of transcription factors are key regulators in the complex process of adipocyte differentiation including peroxisome proliferator activated receptor gamma (PPARgamma) and the CCAAT enhancer binding protein alpha (C/EBPalpha). Studies have demonstrated that in pre-adipocyte 3T3-L1 cells constitutive expression of the DNA binding proteins GATA-2 and GATA-3 results in protein/protein interactions with C/EBPalpha resulting in down regulation of PPARgamma and subsequent suppressed adipocyte differentiation with cells trapped at the pre-adipocyte stage. Thus it appears that GATA-2 and GATA-3 are of critical importance in regulating adipocyte differentiation through molecular interactions with PPARgamma and C/EBPalpha. Recent reports suggest that berberine, an isoquinoline derivative alkaloid isolated from many medicinal herbs prevents differentiation of 3T3-L1 cells via a down regulation of PPARgamma and C/EBPalpha expression. The aim of this study was to determine the effect of berberine on GATA-2 and 3 gene and protein expression levels during differentiation of 3T3-L1 cells. MTT (Methylthiazolyldiphenyl-tetrazolium bromide) was used to detect the cytotoxic effects of berberine on the viability of 3T3-L1 cells during proliferation and differentiation. Differentiation of 3T3-L1 cells was monitored by Oil Red O staining and RT-PCR of PPARgamma and C/EBPalpha and the expression of GATA-2 and 3 was determined by RT-PCR and Western Blot. Results show that following treatment with 8microM berberine the mRNA and protein expression levels of GATA-2 and 3 were elevated and accompanied by inhibited adipocyte differentiation. These results may lead to the use of berberine to target the induction of specific genes such as GATA-2 and GATA-3 which affect adipocyte differentiation.

Is the prevalence of deliberate penetrating trauma increasing in London? Experiences of an urban pre-hospital trauma service.

BACKGROUND: Recent media interest in stabbings and shootings has lead to the general assumption that injury and death secondary to deliberate penetrating trauma are rising. The aim of this study was to establish the prevalence of deliberate penetrating trauma within a London-based physician-led pre-hospital trauma service, and evaluate whether the perceived increase reported by the media translates into a real increase in penetrating trauma caseload. METHOD: A retrospective review of a physician-led pre-hospital care trauma database was conducted to identify all patients who sustained stabbing or shooting injuries over a 16-year period. Patients who died in the pre-hospital phase and paediatric patients were included. Other local and national datasets were examined to determine whether similar trends were observed. RESULTS: 1564 penetrating trauma victims were identified, including 92 children. 1358 patients (86.8%) sustained stab wounds; 206 patients were shot (13.2%). Penetrating injury accounted for 9.9% of the overall trauma caseload during the study period. The annual increase in patients sustaining stabbing injuries was 23.2%. Gun shot wounds increased by 11.0% per year. CONCLUSION: The study demonstrates a significant annual rise in the number of cases of deliberate penetrating trauma managed by a UK physician-led pre-hospital trauma service.

Pre-hospital use of ketamine in paediatric trauma.

OBJECTIVES: To describe the use of ketamine in children by a pre-hospital physician-based service. METHODS: A five and a half year retrospective database review of all patients aged <16 years who were attended by London's Helicopter Emergency Medical Service and given ketamine. RESULTS: One hundred and sixty-four children met the inclusion criteria. The median age was 10 years (range 0-15 years). One hundred and four (63%) had a Glasgow Coma Scale (GCS) of 15 and 153 (93%) had a GCS>8 before administration of ketamine. Patients received from 2 to 150 mg ketamine IV (mean=1.0 mg/kg) and 112 (68%) received concomitant midazolam (0.5-18 mg, mean=0.1 mg/kg). One hundred and forty-one (86%) received ketamine intravenously and 23 (14%) intramuscularly. Only 12 patients (7%) were trapped. The most common mechanisms of injury in those who received ketamine were road traffic collisions, burns and falls. CONCLUSION: The safe delivery of adequate analgesia and appropriate sedation is a priority in paediatric pre-hospital care. Ketamine was predominantly used in awake non-trapped patients with blunt trauma for procedural sedation and analgesia. Detailed database searches did not demonstrate loss of airway, oxygen desaturation or clinically significant emergence reactions after ketamine administration. This study failed to demonstrate any major side effects of the drug and reassured us that the safety profile of the drug in this environment is likely to be satisfactory. The use of ketamine in trapped children was rare.

Medical response times to major incidents: potential benefits of a regional air ambulance mutual aid scheme.

In the event of major incidents, neighbouring air ambulances can be used to assist. To assess the potential benefit of this cooperation, three fictitious major incidents were described to emergency service dispatch desks to assess the availability and response times for neighbouring air ambulances. A medical infrastructure at each site could be in place in a shorter time when the mutual aid scheme was used. This short study demonstrates the increased availability of doctors and flight paramedics that can be achieved by cooperation schemes. The costs of such schemes are minimal where air ambulances already exist. Ambulance services can use this type of scheme rapidly to place a comprehensive medical infrastructure for major incidents.

Identification of bidirectional promoters in the human KIR genes.

Although the class I MHC receptors expressed by human and mouse natural killer (NK) cells have distinct molecular origins, they are functional analogues that are expressed in a variegated pattern. The murine Ly49 class I receptors contain bidirectional promoters that have been proposed to control the probabilistic expression of these genes. Whether similar elements are present in the human killer Ig-like receptor (KIR) genes is a fundamental question. A detailed analysis of the 2 kb intergenic region separating the KIR2DL4 gene and the adjacent KIR3DL1 gene revealed that additional promoter elements exist in the human KIR genes. Remarkably, the previously characterized KIR3DL1 proximal promoter possesses bidirectional promoter activity that maps to an 88 bp DNA fragment containing CREB, AML, Sp1 and Ets transcription factor binding sites. Individual KIR genes and alleles possess bidirectional promoters with distinct properties. Analysis of KIR(+)and KIR(-) NK cells and NK precursors indicates that reverse transcripts from the bidirectional promoter are found in cells that lack KIR protein expression, but are not present in mature KIR-expressing NK cells, suggesting that reverse transcription from the proximal promoter blocks gene activation in immature NK and precursor cells.

Military perspective on the civilian response to the London bombings July 2005.

With the break up of the Warsaw Pact and changing global relations, current military deployments are becoming smaller and more expeditionary (e.g. Afghanistan, East Timor and Sierra Leone). During the Cold War, the use of weapons of mass effect was highly likely to have been seen on the battlefield. Ironically, the proliferation of CBRN agents and the knowledge of their application, as well as the manufacture of improvised explosive devices, have lead to the targeting of civilian populations by extremist groups. One of the benefits of military clinicians embedded in NHS hospital trusts, as well as a strong reservist cadre, is a greater understanding of the implications and management of asymmetric attacks against the U.K. The experience and skills of military clinicians may be of benefit to NHS trusts while this type of threat exists. Military clinicians are also likely to benefit from the experience that they get in certain NHS posts that provide skills that are readily transferable to military medicine. The events of 7th July highlighted the dynamic use of deployable medical resources and a rapid return to normal service provision. This type of 'Health Resilience' can only be achieved with a combination of effective emergency planning, on scene clinical risk management and clinical leadership.

London bombings July 2005: the immediate pre-hospital medical response.

On July 7th 2005 a series of terrorist bombs exploded in London. The transport system was targeted and at least 54 passengers were killed and around 700 injured. This paper describes the immediate pre-hospital medical response to the four scenes. From the perspective of the London Helicopter Emergency Medical Service the deployment, difficulties on scene and the initial lessons learned are discussed.

Variation in alphoid DNA size and trisomy 21: a possible cause of nondisjunction.

The cause of nondisjunction of chromosome 21 remains largely unknown. In the present report, we investigate the hypothesis that variation in alphoid DNA size has a role in trisomy formation. Pulsed-field gel electrophoresis was used to examine the chromosome 21 alphoid DNA array lengths in 23 families (all of Northern European ancestry) with an affected child with trisomy 21 in whom the parental and meiotic origin of nondisjunction had been determined as maternal meiosis I, and in 38 controls. Initially, the combined alphoid size of both chromosome 21 homologues was assessed. This indicated an association between small combined alphoid size and maternal meiosis I nondisjunction. Moreover, in a subset of the families under study (n=12), it was possible to study the alpha21-I size of individual chromosome 21 homologues (simple alphoid size); this provided further evidence that the risk for nondisjunction is related to the size of the alphoid array of one of the two chromosome 21 homologues being small.

The ovine CCAAT-enhancer binding protein delta gene: cloning, characterization, and species-specific autoregulation.

Transcription factors belonging to the CCAAT-enhancer binding protein (C/EBP) family have been implicated in the regulation of gene expression during growth, differentiation, apoptosis, and inflammation. Autoregulation is relatively common in the modulation of C/EBP gene expression and, for the human and murine C/EBPalpha, it is known that species-specific autoregulatory mechanisms operate. It is therefore essential to investigate the autoregulation of additional C/EBP genes from a wider range of different species to gauge the degree of commonality, or otherwise, which exists. As an important step towards this goal, we report here the cloning and the characterisation of the ovine C/EBPdelta gene (ovC/EBPdelta) and analysis of its promoter region. Transient transfection assays reveal that ovC/EBPdelta acts as a transcriptional activator. Although several motifs that are characteristic of C/EBPdelta genes are conserved in the ovine sequence, including the basic region, leucine zipper, and activation domains, two regions have been identified that are specifically absent in the ovine and bovine homologues. The ovC/EBPdelta promoter is active in both the hepatoma Hep3B and the mammary epithelial HC11 cell lines, induced by the cytokine interleukin-6 and autoregulated by mechanisms that are potentially different from those described for the rat promoter. These results suggest that, in common with C/EBPalpha, the C/EBPdelta genes may also be subject to autoregulation by distinct species-specific mechanisms.

Heterotrisomy, a significant contributing factor to ventricular septal defect associated with Down syndrome?

Down syndrome (DS; trisomy 21) is associated with a wide range of variable clinical features, one of the most common being congenital heart defects (CHD). We used molecular genetic techniques to study the inheritance of genes on chromosome 21 in children with DS and CHD. Polymorphic markers on the long arm of chromosome 21 were analysed in 99 families who had a child with DS. Of these, 60 children had a CHD and 39 children had no CHD. Heterotrisomy describes the inheritance of an allele from each of three different grandparents. In some cases heterotrisomy will involve the inheritance of three different alleles. Heterotrisomic regions were defined as those showing retention of non-disjoining parental heterozygosity at polymorphic loci in the non-disjoined chromosomes of children with DS. Using polymorphic non-coding markers, we identified a consistent 9.6-cM minimum region (D21S167-HMG14) of heterotrisomy in children with DS and ventricular septal defect (VSD). Comparing individuals with DS and VSD to all others with DS (those either with no CHD or with any other CHD combined) shows the individuals with DS and VSD to have significantly more non-reduction or heterotrisomy in this region (P=0.006, Fisher's exact test, two-tailed). We postulate that heterotrisomy for a gene or genes in this region is a contributing factor to the pathogenesis of VSD in trisomy 21 either through the presence of three different specific alleles or through the presence of specific combinations of alleles.

Novel methodology for the detection of chromosome 21-specific alpha-satellite DNA sequences.

We present a novel method, based on the hybridization of allele-specific oligonucleotide probes, that allows the specific detection of chromosome 21 alpha-satellite sequences. Absence of informative polymorphic markers from the centromeric region of chromosome 21 has constituted one of the difficulties in studying the centromere of this chromosome. The alpha-satellite subfamilies from chromosomes 21 and 13 are almost identical in sequence and thus cannot be distinguished using conventional hybridization techniques. Analysis using nuclear families showed that the centromeric polymorphism, detected using our specific probe and pulsed-field gel restriction analysis, segregates in a Mendelian fashion and exhibits a high degree of polymorphism among unrelated individuals. The alphoid DNA of chromosome 21 is highly polymorphic, useful not only as a definitive anchor for the genetic map, but also for studies of chromosome 21 nondisjunction, including the unequivocal assignment of meiotic origin.

Expression of the genes encoding CCAAT-enhancer binding protein isoforms in the mouse mammary gland during lactation and involution.

Transcription factors belonging to the CCAAT-enhancer binding protein (C/EBP) family have been implicated in the activation of gene expression in the mammary gland during lactation. We have therefore investigated the detailed expression profile of the C/EBP family during lactation and involution of the mouse mammary gland. The expression of C/EBPbeta and C/EBPdelta mRNA was low during lactation, increased dramatically at the beginning of involution and remained constant thereafter. In contrast, C/EBPalpha mRNA expression was relatively high during the early stages of lactation, declined to low levels during the late stages of lactation and at the start of involution, and increased again during involution. Electrophoretic mobility-shift assays showed a close correlation between the expression of the C/EBP genes and the functional C/EBP DNA-binding activity and, additionally, demonstrated the participation of heterodimers, formed from among the three proteins, in DNA-protein interactions. The DNA-binding activity of the activator protein 1 (AP1) family of transcription factors was also induced during involution. These results therefore point to potentially important regulatory roles for both the C/EBP and the AP1 family during lactation and involution of the mammary gland.

Allelic variability in D21S11, but not in APP or APOE, is associated with cognitive decline in Down syndrome.

Genetic variation in the APOE gene and variation in chromosome 21 genotypes, including the APP locus, may influence age-associated cognitive decline in adults with Down syndrome. Molecular genetic and longitudinal neuropsychological analysis was performed for 41 unrelated Caucasian individuals (mean age 48.1 +/- 1.1 years (s.c.m.)) with free trisomy 21. Allele frequencies and genotype distributions were compared among subgroups with or without evidence of cognitive decline. Genetic variability at APOE and APP was not significantly associated with evidence of cognitive decline. However, aged individuals with Down syndrome, without evidence of cognitive decline, demonstrated unusual allelic variability at D21S11. These findings are discussed in the context of current hypotheses of Alzheimer-type dementia in Down syndrome and in the general population.