Prenatal alcohol exposure alters expression of genes involved in cell adhesion, immune response, and toxin metabolism in adolescent rat hippocampus

Prenatal alcohol exposure (PAE) can result in mild to severe consequences for children throughout their lives, with this range of symptoms referred to as Fetal Alcohol Spectrum Disorders (FASD). These consequences are thought to be linked to changes in gene expression and transcriptional programming in the brain, but the identity of those changes, and how they persist into adolescence are unclear. In this study, we isolated RNA from the hippocampus of adolescent rats exposed to ethanol during prenatal development and compared gene expression to controls. Briefly, dams were either given free access to standard chow ad libitum (AD), pair-fed a liquid diet (PF) or were given a liquid diet with ethanol (6.7% ethanol, ET) throughout gestation (gestational day (GD) 0-20). All dams were given control diet ad libitum beginning on GD 20 and throughout parturition and lactation. Hippocampal tissue was collected from adolescent male and female offspring (postnatal day (PD) 35-36). Exposure to ethanol caused widespread downregulation of many genes as compared to control rats. Gene ontology analysis demonstrated that affected pathways included cell adhesion, toxin metabolism, and immune responses. Interestingly, these differences were not strongly affected by sex. Furthermore, these changes were consistent when comparing ethanol-exposed rats to pair-fed controls provided with a liquid diet and those fed ad libitum on a standard chow diet. We conclude from this study that changes in genetic architecture and the resulting neuronal connectivity after prenatal exposure to alcohol continue through adolescent development. Further research into the consequences of specific gene expression changes on neural and behavioral changes will be vital to our understanding of the FASD spectrum of diseases.

Extended surgical safety margins and ulceration are associated with an improved prognosis in pleomorphic dermal sarcomas

BACKGROUND

Pleomorphic dermal sarcomas (PDS) are frequent UV-induced sarcomas of the skin of intermediate grade malignant potential. Despite the fact that PDS have a noteworthy potential to recur (up to 28%) as well as to metastasize (up to 20%), there are no specific clinical guidelines with respect to follow-up these patients. Moreover, little is known about clinical, histological or molecular prognostic factors in PDS.

OBJECTIVE

The aim of the present study was to identify risk factors to predict relapse in a large multicentre sample cohort of PDS which could aid to optimize personalized treatment recommendations regarding surgical safety margins and adjuvant radiotherapy.

METHODS

Patients with a diagnosis of PDS were selected from nine European institutions based on the histopathologic criteria described by Fletcher. Clinicopathologic and follow-up data were collected and statistically analysed calculating univariate hazard ratios with 95% confidence intervals by use of the Cox proportional-hazards model and a significance level of P < 0.05. Patients with an incomplete excision of the tumour were excluded.

RESULTS

Univariate Cox regression analysis of possible prognostic factors for progression-free survival (PFS) performed in 92 patients revealed that an excision margin of <2 cm is significantly associated with relapse of PDS [hazard ratio 4.478 (95% CI 1.536-13.055), P = 0.006]. Ulceration of the tumour was associated with a significantly better prognosis [0.396 (0.174-0.904), P = 0.028] whereas adjuvant radiotherapy did not reach statistical significance to improve prognosis in patients with PDS [0.775 (0.231-2.593), P = 0.679]. Gender, age, immunosuppression, intratumoural necrosis, tumour location, vertical thickness or horizontal diameter did not significantly influence PFS in PDS.

CONCLUSION

We identified surgical safety margins of <2 cm and absence of ulceration as risk factors for relapse in patients with PDS. These findings may be implemented into both the primary treatment as well as the further monitoring of patients with PDS.

Modified Vaccinia Virus Ankara: History, Value in Basic Research, and Current Perspectives for Vaccine Development

Safety tested Modified Vaccinia virus Ankara (MVA) is licensed as third-generation vaccine against smallpox and serves as a potent vector system for development of new candidate vaccines against infectious diseases and cancer. Historically, MVA was developed by serial tissue culture passage in primary chicken cells of vaccinia virus strain Ankara, and clinically used to avoid the undesirable side effects of conventional smallpox vaccination. Adapted to growth in avian cells MVA lost the ability to replicate in mammalian hosts and lacks many of the genes orthopoxviruses use to conquer their host (cell) environment. As a biologically well-characterized mutant virus, MVA facilitates fundamental research to elucidate the functions of poxvirus host-interaction factors. As extremely safe viral vectors MVA vaccines have been found immunogenic and protective in various preclinical infection models. Multiple recombinant MVA currently undergo clinical testing for vaccination against human immunodeficiency viruses, Mycobacterium tuberculosis or Plasmodium falciparum. The versatility of the MVA vector vaccine platform is readily demonstrated by the swift development of experimental vaccines for immunization against emerging infections such as the Middle East Respiratory Syndrome. Recent advances include promising results from the clinical testing of recombinant MVA-producing antigens of highly pathogenic avian influenza virus H5N1 or Ebola virus. This review summarizes our current knowledge about MVA as a unique strain of vaccinia virus, and discusses the prospects of exploiting this virus as research tool in poxvirus biology or as safe viral vector vaccine to challenge existing and future bottlenecks in vaccinology.

Verrucous carcinoma in epidermolysis bullosa simplex is possibly associated with a novel mutation in the keratin 5 gene

Epidermolysis bullosa simplex (EBS) is mainly caused by mutations in the KRT5 and KRT14 genes. Squamous cell carcinoma (SCC) represents the second most frequent skin neoplasia with complex aetiology. The molecular events disrupting the orchestrated interplay between the cytoskeleton, cell adhesion molecules and signalling proteins are ill understood in SCC. We describe the molecular background and the unusual course of the disease in a patient with EBS Dowling-Meara, severe keratoderma and a massive verrucous carcinoma. Skin and tumour samples from the patient were analysed using light microscopy, immunohistochemistry and immunofluorescence mapping. Mutation analysis of the KRT5 and KRT14 genes identified the novel KRT5 mutation p.E477D. Invasive tumour areas were characterized by downregulation of keratins 5 and 14, reduced and irregular desmocollin-2 expression and increased expression of keratins 6, 16 and 17. Levels of Ki-67 were increased and levels of E-cadherin strongly reduced in the tumour tissue. In this case a novel KRT5 mutation led to increased fragility of keratinocytes. Desmosome and adherens junctions were destabilized, which may trigger keratinocyte-mediated inflammation, possibly via p120-catenin-dependent signalling, suggesting a link between a keratin mutation and SCC, which adds weight to the hypothesis that disturbance of the cytoskeleton represents a major cause in the appearance of the malignant phenotype. Some individuals with EBS may be at risk of developing secondary SCC.

Perforation of the left atrium by a chest tube in a patient with cardiomegaly: management of a rare, but life-threatening complication

Perforation of the heart is a rare, but life-threatening complication of chest tube thoracostomy. We report the very unusual case where right-sided insertion of a Matthys catheter (6 F) due to pleural effusion resulted in a left atrium perforation. Heart injury was immediately considered as a continuous flow of bright red blood emerging through the chest drain. Diagnosis was confirmed by computertomography also revealing a massive cardiomegaly due to pre-existing mitral valve regurgitation. In two consecutive thoracotomies, first the Mathys drain was removed and the heart defect closed and then the mitral valve was replaced by a bio prosthesis. The extent of the cardiomegaly and the position of the left atrium were not detected pre-operatively by chest X-ray or ultrasonic device. Despite a nosocomial pneumonia, the patient fully recovered. This case shows that extreme caution is necessary when inserting chest tubes in patients where thorax imaging by X-ray or ultrasonic device does not provide a clear anatomical site. In order to minimise complications, a blunt puncturing procedure or Seldinger technique should be used and assisted by a Doppler ultrasonic device. Also early imaging by CT and Doppler ultrasonic technique should be attempted. This may reduce incidence of severe complications as in this case.

Benzodiazepines for schizophrenia

BACKGROUND

Many people with schizophrenia do not achieve a satisfactory treatment response with ordinary antipsychotic drug treatment. In these cases, various add-on medications are used, among them benzodiazepines.

OBJECTIVES

To review the effects of benzodiazepines for the treatment of schizophrenia and schizophrenia-like psychoses.

SEARCH STRATEGY

The reviewers searched the Cochrane Schizophrenia Group's register (last search March 2005). This register is compiled by methodical searches of BIOSIS, CINAHL, Dissertation abstracts, EMBASE, LILACS, MEDLINE, PSYNDEX, PsycINFO, RUSSMED, Sociofile, supplemented with hand searching of relevant journals and numerous conference proceedings. We also contacted authors of relevant studies in order to obtain missing data from existing trials.

SELECTION CRITERIA

All randomised controlled trials comparing benzodiazepine to antipsychotics or to placebo (or no intervention), whether as sole treatment or as an adjunct to antipsychotic medication for the treatment of schizophrenia and/or schizophrenia-like psychoses.

DATA COLLECTION AND ANALYSIS

We independently inspected abstracts, selected studies and re-inspected and quality assessed the full reports. We independently extracted relevant outcomes. Dichotomous data were analysed using relative risks (RR) and the 95% confidence intervals (CI). Continuous data were analysed using weighted mean differences. Where possible the number needed to treat (NNT) or number needed to harm (NNH) statistics were calculated.

MAIN RESULTS

The review currently includes 31 studies with over 2000 participants. Most studies were small, of short duration - one to 13 weeks - and inconsistently and incompletely reported. Eight studies compared benzodiazepines as a sole agent with placebo. More participants receiving benzodiazepines showed a clinically significant response (n=222, 4 RCTs, RR 0.54 CI 0.3 to 1.0, NNT 3 CI 2 to 17). Only one small study found a significant group difference in favour of benzodiazepines regarding the improvement in overall BPRS mental state. Different rating scales were used to assess general mental state, and therefore many outcomes could not be pooled and no overall direction of effect emerged. Some adverse events observed in these studies suggested that benzodiazepines were more harmful than placebos but again the data were incompletely reported and without overall effect. Thirteen studies examined the effects of benzodiazepines in comparison to antipsychotics as a sole treatment. Trials that reported on clinical response found no advantage for any treatment group concerning improvement of the participants' global state, except of one small study that analysed the mean CGI severity score at one hour. This comparison is highly limited by the low numbers of studies reporting on global function and the short trial duration. Two studies showed a statistically significant superiority of antipsychotics in terms of relapse prevention at one year. Desired sedation occurred significantly more often among participants in the benzodiazepine group than among participants in the antipsychotic treatment group at 20 (n=301, 1 RCT, RR 1.32 CI 1.2 -1.5, NNT 5, CI 3 to 8) and 40 minutes(n= 301, 1 RCT, RR 1.13 CI 1.0 to 1.2, NNT 9 CI 6 to 33), but not at 30, 60 or 12 minutes. Other outcomes relating to the general or specific mental state revealed no significant differences between groups. As far as adverse events were reported there were no results in favour of any group. Sixteen studies examined whether the augmentation of antipsychotics with benzodiazepines is more effective than antipsychotics as a sole treatment. During the first hour of treatment the combination treatment group benefited from the additional benzodiazepine in terms of the participants global state. This benefit diminished over time and was not reproducible at 2 hours or longer. No superior efficacy of benzodiazepine augmentation could be found regarding the general mental state. Specific aspects of the mental state showed no group difference except for desired sedation at 30 and 60 minutes. Somnolence affected the combination treatment group significantly more than the control group (n=118, 2 RCTs, RR 3.30 CI 1.0 to 10.4, NNH 8 CI 5 to 50). We found use of antiparkinson medication to be less frequently used in the combination treatment group (n=282, RR 0.68 CI 0.5 to 1.0, NNT 9 CI 6 to 48). Adverse events were poorly reported and the results were based on very little data.

AUTHORS' CONCLUSIONS

Randomised trial-derived evidence is currently too poor to recommend benzodiazepines neither as a sole nor as an adjunctive agent in schizophrenia or schizophrenia-like psychoses. The only significant effects were seen in terms of short-term sedation, at best. The evidence available on augmentation of antipsychotics with benzodiazepines is inconclusive and justifies large, simple and well-designed future trials focusing on clinical response, mental state, aggressive behaviour and adverse events.

Delays to treatment and out-of-pocket medical expenditure for tuberculosis patients, in an urban area of South America

Short delays to treatment are important for the control of tuberculosis (TB). National Tuberculosis Programmes provide free diagnosis and treatment for smear-positive patients, so that the patients' out-of-pocket medical expenditure could be almost nil. The factors associated with delays in starting treatment, and the pre-treatment out-of-pocket medical expenditure for TB patients, have now been investigated in the Bolivian city of Cochabamba. Bolivia is the Latin American country with the highest incidence of TB. It is covered by a national TB programme that provides free diagnosis and free treatment for smear-positive patients. Structured interviews with 144 smear-positive patients enrolled in this programme revealed median patient, provider and total delays of 3.6, 6.2 and 12.9 weeks, respectively. The total delays were longer for the female patients than for the male, and for patients who consulted private doctors than for the other patients. When the first healthcare provider was a doctor, the median provider delay was 4.9 weeks in the public sector but 7.2 weeks in the private. The median out-of-pocket medical expenditure per patient, which was U.S.$13.2 overall, was much higher for those who consulted a private doctor than for those who did not (U.S.$21.9 v. U.S.$5.4, respectively; P<0.001). It appears that interventions targeting doctors (in both the private and public sectors) are likely to have a larger impact on the shortening of delays in TB treatment than interventions targeting patients. They could also reduce unnecessary out-of-pocket expenditure.

[Polytrauma with tension pneumothorax with inserted chest tube]

The authors report a case of a 25-year-old woman with a polytrauma, caused by a free fall of 12 metres in suicidal intention. Following endotracheal intubation and mechanical ventilation by an emergency physician at the scene, the patient was delivered to the emergency room of an university hospital. An ultrasonic check of the abdomen revealed free fluid in the abdominal cavity, and a rupture of liver and spleen was suspected. Since breath sounds over the right lung were diminished, a chest tube was inserted immediately in the fifth intercostal space in the anterior axillary line. About 300 millilitres of blood were drained by the tube. Shortly thereafter, a laparotomy was performed, where spleen and liver rupture were confirmed and treated. After 60 minutes, the patient developed severe hypotension coupled with ventricular tachycardia and fibrillation, and resuscitation measures had to be initiated. Since breath sounds over the right lung were missing, a tension pneumothorax was suspected and a thoracotomy performed immediately. While huge amounts of air and blood were emerging from the thoracic cavity, a rupture of the right mainstem bronchus as well as of the right pulmonary artery and vena subclavia was identified. The chest tube was found dislocated into the subcutaneous tissue. Despite of open heart compression, application of adrenaline and noradrenaline and substitution of packed red blood cells and of crystalloid and colloid solutions, all resuscitation measures failed so that the patient died shortly after on the operation table. This case illustrates first the difficulties of an adequate thoracic trauma management, particularly, when clinical symptoms are discrete, second the problems of the insertion and control of a chest tube, and third risks associated with wrong position or secondary dislocation which may include - as in our case - "masking" of severe injury patterns and delay of life-saving measures such as an immediate thoracotomy. In order to improve prognosis of patients with poly-/thoracic trauma, establishment of spiral-CT in emergency centres, routine bronchoscopy and safe handling of chest tubes may be helpful.

The soluble pool of HLA-G produced by human trophoblasts does not include detectable levels of the intron 4-containing HLA-G5 and HLA-G6 isoforms

In the context of implantation and pregnancy, several immunomodulating functions have been attributed to the different HLA-G isoforms. Increasing attention is now being addressed to the actively secreted soluble forms, because they might have a systemic function or could be useful as diagnostic tools. However, the cellular source of secretion, even during pregnancy, where HLA-G expression level is known to be highest, is still under debate. To elucidate the conflicting results, we investigated the isoform distribution in human first trimester and term placentas in situ and in vitro. Results obtained by applying immunohistochemistry, western blot, enzyme-linked immunosorbent assay (ELISA) and RT-PCR show that (1) all of the alpha1 domain-containing HLA-G isoforms are restrictedly expressed in the extravillous cytotrophoblasts (EVCTs) and very few first-trimester syncytiotrophoblasts, which directly cover cell columns, whereas mesenchymal cells of the villous chorion do not express HLA-G; (2) as demonstrated in western blots, trophoblasts express only the HLA-G1 isoform; (3) HLA-G5 and -G6 transcripts could be detected in human term placenta and isolated first-trimester trophoblasts but levels are extremely low; and (4) conditioned media of primary first-trimester trophoblasts, and the chorion laeve-derived trophoblastic cell line AC1-M59 do contain HLA-G1 fragments shed from the cell surface. Our data provide substantial evidence that none of the intron 4-containing isoforms, the so-called actively secreted, soluble HLA-G5 or -G6, are produced by human trophoblasts in situ or in vitro.

Tuberculosis control and the private health sector in Bolivia: a survey of pharmacies

BACKGROUND

Bolivia is a high tuberculosis (TB) incidence country with a large private for-profit health sector. TB drug sales in private pharmacies are not illegal.

OBJECTIVES

To measure the availability of TB drugs in private pharmacies, study vendors' attitudes, and explore the potential for collaboration between the public health sector and pharmacies.

METHODS

Simulated clients visited a random sample of 100 pharmacies in the city of Cochabamba, presenting with a prescription for four TB drugs. After the survey, contacts were made with the local Pharmacist's Association.

RESULTS

Twenty-five pharmacies sold at least one drug, 23 sold rifampicin and 16 sold isoniazid. Of 99 pharmacies unable to fill the whole prescription, 59 referred the client to another pharmacy, and 22 to the public services. Pharmacists said that rifampicin was often prescribed for non-TB indications, and that TB drug sales were of minimal contribution to their income. They agreed to stop selling the drugs and to refer clients seeking them to the public sector.

CONCLUSION

This study has documented a small market for TB drugs sales in private pharmacies and provided the opportunity to start collaboration with the pharmacists. Our results suggest that the private sector contributes little to managing TB in Bolivia.

Nucleation and growth of molecular organic crystals in a liquid film under vapor deposition

We report on the nucleation and growth of tetracene in a thin liquid film which is continuously supersaturated by vapor deposition of molecules onto the film. In a first stage, nucleation and fast anisotropic two-dimensional dendritic growth occurs. In a second stage, the dendrites coarsen into pallet-shaped crystals. These are highly oriented with respect to the plane of the liquid film and reach a lateral size of several 100 microm. The two-dimensional growth mode is explained by the confined growth geometry in the liquid in combination with the anisotropy of the crystal structure.

Candidate gene analysis of KIAA0678 encoding a DnaJ-like protein for adolescent nephronophthisis and Senior-Løken syndrome type 3

Nephronophthisis (NPH), an autosomal recessive cystic kidney disease, causes progressive renal failure. The gene for adolescent nephronophthisis (NPHP3) has been mapped to chromosome 3q21-->q22. Senior-Løken syndrome (SLS) describes the association of NPH and Leber congenital amaurosis. Recently a locus for Senior-Løken syndrome (SLSN3) has been localized on chromosome 3q21-->q22 containing the whole critical NPHP3 region. Within the critical NPHP3/SLSN3 region we identified the gene KIAA0678 encoding a DnaJ-like protein. KIAA0678 was considered a good functional candidate gene for NPH3 and SLS3, because molecular cha- perones are involved in the etiology of renal and retinal diseases. Analysis of the genomic structure of KIAA0678 identified 25 exons. For mutational analysis all exons and intron-exon boundaries were amplified and directly sequenced. Affected individuals of two NPH3 families and one SLS family with haplotypes indicative for homozygosity by descent for the NPHP3/SLSN3 locus were studied. No mutation in KIAA0678 was detected. We conclude, KIAA0678 most likely is not responsible for NPH and SLS in the patients studied.

[Methods of process analysis, instruments of quality management. Successful implementation of quality projects]

Meaningful experience and knowledge--the prerequisite for the successful implementation of quality projects--are described in terms of their practical importance on the basis of the experience gained with quality management in the municipal hospital at München-Schwabing (HMS). Against the background of the process of quality assurance or PDCA (Plan Do Check Act), the approach to the selection of suitable themes (problem selection), the prioritization of projects, the appropriate composition of the project group, the description of the problem, and the organization of the project, are discussed. The authors describe the implementation of methods of process analysis such as flow diagrams and cause-and-effect diagrams. The importance of evaluation is justified, and pragmatic approaches are presented. The importance of project documentation and essential contents are discussed.

A human mitochondrial ferritin encoded by an intronless gene

Ferritin is a ubiquitous protein that plays a critical role in regulating intracellular iron homoeostasis by storing iron inside its multimeric shell. It also plays an important role in detoxifying potentially harmful free ferrous iron to the less soluble ferric iron by virtue of the ferroxidase activity of the H subunit. Although excess iron is stored primarily in cytoplasm, most of the metabolically active iron in cells is processed in mitochondria. Little is yet known of how these organelles regulate iron homeostasis and toxicity. Here we report an unusual intronless gene on chromosome 5q23.1 that encodes a 242-amino acid precursor of a ferritin H-like protein. This 30-kDa protein is targeted to mitochondria and processed to a 22-kDa subunit that assembles into typical ferritin shells and has ferroxidase activity. Immunohistochemical analysis showed that it accumulates in high amounts in iron-loaded mitochondria of erythroblasts of subjects with impaired heme synthesis. This new ferritin may play an important role in the regulation of mitochondrial iron homeostasis and heme synthesis.

Genesis of the ILT/LIR/MIR clusters within the human leukocyte receptor complex

The human leukocyte receptor complex (LRC) contains at least 26 genes which belong to the immunoglobulin superfamily The genes include two clusters of immunoglobulin-like transcript (ILT)/leukocyte immunoglobulin-like receptor (LIR)/monocyte-macrophage inhibitory receptor (MIR) loci, a cluster of killer cell inhibitory receptor (KIR) genes, two leukocyte-associated immunoglobulin-like receptor genes, as well as the Fc receptor for IgA and the natural cytotoxicity receptor I loci. It has already been postulated that these genes have evolved by multiple duplications, while the two ILT clusters are likely to have been generated by the inverse duplication of an ancient ILT cluster. To shed more light on the possible origin of the loci within the LRC, we have now investigated the presence of KIR and ILT loci in a variety of vertebrates by hybridizations and compared the genomic sequences of all ILT genes. Our results lead to the following conclusions: 1) the origin of KIR genes dates back to about 100 million years, but only primate and human KIRs are closely related; 2) in contrast, genes which are detectable with human ILT cDNAs are already found in birds, suggesting their presence already about 300 million years ago. Using the sequence data produced by the human genome project, we have developed a hypothesis that reconstructs the genesis of the two human ILT clusters in detail which will help to understand the function of the LRC.

Characterization of clustered MHC-linked olfactory receptor genes in human and mouse

Olfactory receptor (OR) loci frequently cluster and are present on most human chromosomes. They are members of the seven transmembrane receptor (7-TM) superfamily and, as such, are part of one of the largest mammalian multigene families, with an estimated copy number of up to 1000 ORs per haploid genome. As their name implies, ORs are known to be involved in the perception of odors and possibly also in other, nonolfaction-related, functions. Here, we report the characterization of ORs that are part of the MHC-linked OR clusters in human and mouse (partial sequence only). These clusters are of particular interest because of their possible involvement in olfaction-driven mate selection. In total, we describe 50 novel OR loci (36 human, 14 murine), making the human MHC-linked cluster the largest sequenced OR cluster in any organism so far. Comparative and phylogenetic analyses confirm the cluster to be MHC-linked but divergent in both species and allow the identification of at least one ortholog that will be useful for future regulatory and functional studies. Quantitative feature analysis shows clear evidence of duplications of blocks of OR genes and reveals the entire cluster to have a genomic environment that is very different from its neighboring regions. Based on in silico transcript analysis, we also present evidence of extensive long-distance splicing in the 5'-untranslated regions and, for the first time, of alternative splicing within the single coding exon of ORs. Taken together with our previous finding that ORs are also polymorphic, the presented data indicate that the expression, function, and evolution of these interesting genes might be more complex than previously thought.

MHC-linked olfactory receptor loci exhibit polymorphism and contribute to extended HLA/OR-haplotypes

Clusters of olfactory receptor (OR) genes are found on most human chromosomes. They are one of the largest mammalian multigene families. Here, we report a systematic study of polymorphism of OR genes belonging to the largest fully sequenced OR cluster. The cluster contains 36 OR genes, of which two belong to the vomeronasal 1 (V1-OR) family. The cluster is divided into a major and a minor region at the telomeric end of the HLA complex on chromosome 6. These OR genes could be involved in MHC-related mate preferences. The polymorphism screen was carried out with 13 genes from the HLA-linked OR cluster and three genes from chromosomes 7, 17, and 19 as controls. Ten human cell lines, representing 18 different chromosome 6s, were analyzed. They were from various ethnic origins and exhibited different HLA haplotypes. All OR genes tested, including those not linked to the HLA complex, were polymorphic. These polymorphisms were dispersed along the coding region and resulted in up to seven alleles for a given OR gene. Three polymorphisms resulted either in stop codons (genes hs6M1-4P, hs6M1-17) or in a 16-bp deletion (gene hs6M1-19P), possibly leading to lack of ligand recognition by the respective receptors in the cell line donors. In total, 13 HLA-linked OR haplotypes could be defined. Therefore, allelic variation appears to be a general feature of human OR genes.

Identification, tissue specific expression, and chromosomal localisation of several human dynein heavy chain genes

Sliding between adjacent microtubules within the axonema gives rise to the motility of cilia and flagella. The driving force is produced by dynein complexes which are mainly composed of the axonemal dynein heavy chains. We used cells of human respiratory epithelium after in vitro ciliogenesis to clone cDNA fragments of nine dynein heavy chain genes, one of which had never been identified before. Dynein heavy chains are highly conserved from protozoa to human and the evolutionary ancestry of these dynein heavy chain cDNA fragments was deduced by phylogenetic analysis. These dynein heavy chain cDNAs are highly transcribed in human tissues containing axonema such as trachea, testis and brain, but not in adult heart or placenta. PAC clones containing dynein heavy chains were obtained and used to determine by FISH their chromosomal position in the human genome. They were mapped to 2p12-p11, 2q33, 3p21.2-p21.1, 13q14, 16p12 and 17p12. The chromosomal assignment of these dynein heavy chain genes which was confirmed by GeneBridge 4 radiation hybrid screening, will be extremely useful for linkage analysis efforts in patients with primary ciliary dyskinesia (PCD).

Polymorphisms in olfactory receptor genes: a cautionary note

The hundreds of human olfactory receptor (OR) genes are organized into clusters occurring on nearly every chromosome. Although their sequences are not always closely related, they share stretches of considerable similarity, both at the amino acid and nucleotide levels. We demonstrate here that an HLA complex-linked OR sequence, FAT11, for which recently a number of alleles have been claimed within the Hutterites, contains sequences derived from two closely related, linked OR genes, hs6M1-12 and hs6M1-16. Instead of indicating a difference between alleles of a given locus, two of the polymorphisms described for FAT11 (at amino acids 48 and 220 of the deduced protein sequence, respectively) may in fact reflect distinct sequences of hs6M1-12 and a further, closely related HLA-linked OR locus, hs6M1-13P. As a consequence, recombination rates in Hutterites in the region telomeric of HLA-G may have to be reconsidered.

Mapping of leukaemia-associated breakpoints in chromosome band 3q21 using a newly established PAC contig

Chromosome aberrations affecting band 3q21 are associated with a particularly poor prognosis in patients with acute myeloid leukaemia. To facilitate the molecular characterization of such rearrangements, we established a PAC contig covering the relevant genomic region. Using these PACs as probes in fluorescence in situ hybridization (FISH) experiments, we showed that a number of 3q21 breakpoints in patient samples map to a previously defined 'breakpoint cluster region'. Others, however, are located at varying distances centromeric of it. These results have important implications in the search for genes affected by 3q21 rearrangements.

Extensive gene duplications and a large inversion characterize the human leukocyte receptor cluster

The chromosomal region 19q13.4 harbors the human leukocyte receptor cluster (LRC) which has been demonstrated to contain 19 genes encoding leukocyte-expressed receptors of the immunoglobulin (Ig) superfamily. A spotted PAC library was used to construct a contig of 65 overlapping clones spanning the complete LRC. Within the 900 kb covered by the contig, we identified one cluster containing killer cell inhibitory receptor genes and two clusters containing Ig-like transcript (ILT) genes. Of these, the second ILT cluster, located at the centromeric end of the LRC, was previously unknown. Detailed analysis of the ILT receptor genes in this cluster revealed one novel (ILT11) and six already known ILT genes. The two ILT clusters are transcribed in opposite directions and are separated by about 200 kb, which contains two leukocyte-associated inhibitory receptor (LAIR) genes. The data suggest that the two ILT clusters, each including one LAIR locus, arose from a single ancestral ILT/LAIR cluster by inverse duplication of a c large genomic fragment. Furthermore, the NK cell-expressed NKp46 gene was localized 20 kb telomeric of FCAR; and 14 novel genes mapping within the LRC were identified by cDNA selection. Together with the gene for the ribosomal protein S9 (RPS9), which had previously been assigned to 19q13.4, the total number of LRC genes is now 44. Of these, 29 belong to the Ig superfamily.

Transcription factor GATA-2 gene is located near 3q21 breakpoints in myeloid leukemia

Rearrangements affecting chromosome band 3q21 are observed in a subgroup of patients with acute myeloid leukemia (AML) or myelodysplastic syndrome (MDS). However, little is known about the molecular consequences of such aberrations. We therefore established a PAC contig in the 3q21 breakpoint region and identified potential protein coding sequences by exon trapping. One of the exons isolated was from the human GATA-2 gene, which we showed to be transcribed from telomere to centromere. The majority of 3q21 breakpoints are located telomeric to the transcribed portion of this gene in a region that in mice appears to be necessary for proper promoter function. Results of GATA-2 expression analyses in leukemic cell lines as well as primary patient samples are compatible with the hypothesis that 3q21 aberrations contribute to leukemogenesis through deregulation of the hematopoietic transcription factor GATA-2.

Dissection of the 5.5 Mbp region directly telomeric of HLA-B including a long range restriction map, YAC and PAC contigs

A large number of diseases are associated with the human major histocompatibility (HLA) complex located in 6p21.3. The underlying defect of most of these has not yet been determined even after detailed analysis of the HLA region. Due to the extended haplotypes found in this area, several of the HLA-linked disease genes may be located also telomeric of the class I region. In order to analyse the area covering the 4 megabases directly telomeric of HLA-F in close detail, we have generated 50 new markers. These and other markers have been used to establish a SalI restriction map from 46 YACs. A subset of 42 markers was applied to construct a genomic long range restriction map from an HLA-A2/B13 haplotype. Both maps have been compared revealing the presence of additional 150 kb in the HLA-A2 haplotype close to the RFP locus. Additionally, 47 PACs have been selected mapping to this region and grouped into 7 contigs. Sequencing of these PAC contigs has already been initiated.

Physical mapping of two histone gene clusters on human chromosome 6p22.1-22.2

Histones are basic proteins which are responsible for the assembly and maintenance of the nucleosomal structure within the chromosomal fiber in eukaryotes. Two clusters of these genes have previously been mapped to the region 6p21.1-p22.2. We describe here a radiation hybrid map, a long range restriction map and a YAC contig covering and linking these two clusters and giving the precise localisation with respect to the HLA complex. The large cluster contains five H1 histone genes in the 6p22.2 region, the smaller only one, H1F5 (H1.5), in 6p22.1. In both clusters, each H1 locus is accompanied by several core histone genes. The large cluster has additionally been covered by a sequence ready PAC contig and three probably unrelated genes (TRMI2, BTN and SSADH) have been accurately localized within the 6p22.2-p22.1 region.

Complex duplications at 6p22.1, 6p11.2, 5q13, 5p15.1 and 5p13 revealed by fluorescent in situ hybridisation

A complex pattern of fluorescent in situ hybridisation (FISH) has been detected using PAC clones from the short arm of chromosome 6, proximal to the haemochromatosis gene at 6p22.1. Cross-hybridisation to 6p22.1, 6p11.2, 5q13, 5p15.1 and 5p13 was consistently detected with several PAC clones covering a genomic region greater than 200 kb. These results indicate that large sections of genomic DNA are shared by these 5 disparate chromosomal segments, indicative of large scale duplication events. These results were in part accounted for by the identification of several expressed sequence tags (ESTs).

Genomic organization of the HSET locus and the possible association of HLA-linked genes with immotile cilia syndrome (ICS)

The kinesin-related protein (HSET) gene belongs to the kinesin superfamily, the members of which are involved in cellular transport processes. The HSET gene product was previously characterized by partial cDNA sequencing. The gene is located on the short arm of human Chromosome 6 (6p21.3), at the centromeric end of the major histocompatibility complex. Here, we report the genomic structure of the complete HSET gene together with its flanking loci. Sequence analysis of the 40 kilobase (kb) cosmid clone containing the HSET gene also revealed the presence of several new genes not related to the kinesin superfamily. These include a 60S ribosomal protein L35A-like pseudogene (rPL35A-like) on the telomeric side and a polycomb-like gene (PHF1), a copper tolerance-like gene (CUTA1) and the 5' part of the synaptic ras-GTPase-activating protein (SynGAP) gene centromeric of HSET. In addition, a complete 60S ribosomal protein L12-like (rPL12L) gene in intron 3 of the HSET gene was identified which appears to have an open reading frame. The possible involvement of the HSET gene and a beta-tubulin gene (TUBB) in the pathogenesis of immotile cilia syndrome (ICS) was studied by screening two unrelated ICS families with microtubular defects and suspected HLA linkage for mutations within the HSET gene and the TUBB gene. Four single base substitutions were detected in the HSET gene, and none in the TUBB gene. On the basis of these data, a role of the HSET and TUBB products in the pathogenesis of ICS in the two families is unlikely.

Organization of the leukocyte receptor cluster (LRC) on human chromosome 19q13.4

A large number of cDNAs coding for killer cell inhibitory receptors (KIR) and immunoglobulin-like transcripts (ILT) have already been described, and some of the respective genes are known to map in 19q13.4. To understand the genetic relationships of these transcripts, some of which may be alleles from polymorphic loci, it is necessary to determine the genomic organization of the region. To do so, we performed long-range restriction enzyme mapping of the 19q13.4 region along with YAC and PAC contig construction. Eighteen genes could be assigned to a chromosomal segment of about 600 kb. Twelve KIR loci are contained within approximately 200 kb, bordered by the locus for the Fc receptor for IgA (FCAR) at the telomeric side and by a 150-kb cluster containing ILT loci at the centromeric side. A further region with a maximal size of 135 kb containing at least one ILT gene was identified further centromeric, separated by approximately 50 kb from the ILT region near the KIR cluster. The entire KIR/ILT region revealed a considerable degree of genetic polymorphism as shown, for example, by different restriction maps of two sets of PACs spanning the same region. We suggest the designation "Leukocyte Receptor Cluster" (LRC) for this chromosomal segment.

Mapping, genomic structure, and polymorphisms of the human GABABR1 receptor gene: evaluation of its involvement in idiopathic generalized epilepsy

Neurophysiological and pharmacological studies suggest a major role of the GABAB receptor in the epileptogenesis of absence seizures. The gene encoding the human GABABR1 receptor (GABABR1) has recently been mapped to human chromosome 6p21.3 by in situ hybridization, a region that harbors a susceptibility locus (EJM1) for idiopathic generalized epilepsy (IGE). We investigated the hypothesis that the GABABR1 gene (GABBR1) represents a candidate gene for EJM1 by: (1) defining the precise localization approximately 130 kilobases telomeric to the HLA-F locus, (2) by characterizing its genomic organization, and (3) by mutation screening of the entire coding region of GABBR1 in 18 German patients with juvenile myoclonic epilepsy (JME) who were derived from families with evidence for linkage to chromosome 6p21.3 (cumulative lod score Z=3.17 at HLA-DQ). The GABAB receptor gene consists of 22 translated exons. The two alternative transcripts, GABABR1a and GABABR1b, are derived from the same locus but they differ in their alternative 5'-exons. Mutation analyses in JME revealed several DNA sequence polymorphisms, two of which result in amino acid changes occurring in all IGE-affected members of two families. However, clinically unaffected relatives did carry the same variations, excluding these amino acid substitutions as the cause for IGE in these families.

[A totally implantable hearing aid for inner ear deafness: TICA LZ 3001]

Recently, Zenner et al. implanted the first totally implantable electronic hearing devices in patients with SNHL (HNO 46 [1998] 844-852). In the present report, technical and audiological features of the implant TICA are published. The development of the piezoelectric transducer and the microphone for implantation in the posterior wall of the auditory canal as components for the present fully implantable hearing system has already been described (HNO 45, 1997, 792-880). Here we report about our experience with the electronic main module that completes the TICA LZ 3001 system. This module is suited for implantation in the mastoid bone and contains the signal-processing electronics and an integrated battery that can be recharged transcutaneously with a portable charger. The recharging time is around 2 h for an implant operating time of 50 h. The microphone and transducer connectors allow for easy replacement of the main module when the battery lifetime is reached. This lifetime is around 3-5 years. A small wireless remote control allows volume adjustment, contains an on/off switch, and permits selection of four different individual hearing programs. The basic audiological features are provided by a flexible, digitally programmable 3-channel-AGC-system with a peak clipping function. The total bandwidth is around 10 kHz. To our knowledge this is the first fully implantable hearing system that has been in implanted in humans.

A 6p22 reference map of leukocyte DNA: exclusion of rearrangement in four cases of atypical haemochromatosis

We describe a 4 Mb reference map of the haemochromatosis gene region in leukocyte DNA from seven controls and four atypical haemochromatosis patients. Three patients had normal coding sequence for HFE, the candidate gene for genetic haemochromatosis (GH). The fourth patient had classical GH but was heterozygous for Cys282Tyr with otherwise normal coding sequence. The genomic DNA was mapped by pulsed-field gel electrophoresis (PFGE) using five rare-cutting enzymes. Seventeen probes including HFE were positioned on the map. Despite proximity to the highly polymorphic major histocompatibility complex (MHC), no polymorphism was observed in the control group with these telomeric probes. Furthermore, major rearrangement of the HFE region was excluded as a mutation contributing to iron overload in these atypical patients. Maps of cloned DNA are linked through genes and other probes to this reference map of the HFE region in uncloned genomic DNA.

Physical map of the D6S149-D6S193 region on chromosome 6Q27 and its involvement in benign surface epithelial ovarian tumours

A detailed long range restriction map of the region defined by markers D6S149 and D6S193 on chromosome 6q27 has been constructed. This was achieved by YAC cloning and contig assembling of the same region. Seven YAC clones were found to span the almost 1000 Kb region flanked by the two markers which on the genetic map resulted to be 1.9 cM apart. With some of the characterized YAC clones we undertook a molecular cytogenetic analysis of 20 benign ovarian tumors. The rationale for this was the recent mapping to a region of chromosome 6q27, flanked by markers D6281 and D6S133, of a locus for the SV40-mediated immortalization of human cells (SEN6 gene). Noteworthy we found that the the D6S149-D6S193 region (comprised in the larger D6S281-D6S133 physical interval) was altered in all samples analysed adding support to the occurrence of a immortalization step in this type of tumors.

Refined mapping of the epilepsy susceptibility locus EJM1 on chromosome 6

Juvenile myoclonic epilepsy (JME) is a genetically determined common subtype of idiopathic generalized epilepsy. Linkage to the HLA complex on chromosome 6p21.3 and an allelic association with HLA-DR13 and -DQB1 alleles suggest that a susceptibility locus for JME, designated as "EJM1," is located within or near the HLA region. However, further studies revealed controversial results, and genetic heterogeneity has been suspected. The present study was designed to evaluate the validity of the association and linkage findings and to refine the map position of EJM1. Our association analysis showed no significant difference of the frequency of HLA-DR13 carriers in 62 German JME patients compared with that in 77 German controls (X2 = 0.98, df = 1, p = 0.161, one-tailed). Multipoint linkage analysis with use of microsatellite markers from the chromosomal region 6p25-q13 in 29 German families of JME patients provided significant evidence that an epilepsy locus (EJM1) close to the HLA locus confers susceptibility to "idiopathic" generalized seizures (Zmax = 3.27 at theta max = 0.033 centromeric to the HLA-DQ locus), assuming an autosomal dominant mode of inheritance with 70% penetrance. Haplotype analyses revealed key recombinations in five families, which locate EJM1 to the centromeric side of the HLA-DQ locus. This study confirms a causative role of EJM1 in the pathogenesis of idiopathic generalized seizures in the majority of German families of JME patients and refines a candidate region of 10.1 cM in the chromosomal region 6p21 between the flanking loci HLA-DQ and D6S1019. A possible explanation for the current controversial results in families of different populations might be ethnic variation of interfering polygenic effects that could be permissive for heterogeneous susceptibility alleles.

Heterogeneity in rates of recombination in the 6-Mb region telomeric to the human major histocompatibility complex

Analysis of 784 informative meioses in the CEPH pedigrees revealed a total of 22 recombination events having occurred in the 6-Mb region between D6S265 (70 kb centromeric of HLA-A) and D6S276. These 22 breakpoints were localized with respect to anonymous polymorphic markers, leading to a detailed genetic map of the region telomeric to the human major histocompatibility complex. A nonrandom pattern of recombination was observed throughout this region: the low recombination rate of 0.19% within the 4-Mb interval centromeric to the HLA class I-like candidate gene for hemochromatosis indeed contrasts with the approximate 1% rate observed within the most telomeric two megabases. This reduced rate of recombination may be due to selective constraints depending on environmental factors related to immunity and iron status or to structural variations hampering proper meiotic pairing of homologous sequences. Population data from other human genome segments are now needed to determine whether linkage disequilibrium extending over 4 Mb is unique to this region.

Genetic analysis of the epidermal differentiation complex (EDC) on human chromosome 1q21: chromosomal orientation, new markers, and a 6-Mb YAC contig

The epidermal differentiation complex (EDC) unites a remarkable number of structurally, functionally, and evolutionarily related genes that play an important role in terminal differentiation of the human epidermis. It is localized within 2.05 Mb of region q21 on human chromosome 1. We have identified and characterized 24 yeast artificial chromosome (YAC) clones by mapping individual EDC genes, sequence-tagged site (STS) markers (D1S305, D1S442, D1S498, D1S1664), and 10 new region-specific probes (D1S3619-D1S3628). Here we present a contig that covers about 6 Mb of 1q21 including the entire EDC. Fluorescence in situ hybridization on metaphase chromosomes with two YACs flanking the EDC determined its chromosomal orientation and established, in conjunction with physical mapping results, the following order of genes and STSs: 1cen-D1S442-D1S498-S100A10-THH-FLG- D1S1664-IVL-SPRR3-SPRR1-SPRR2-LOR- S100A9-S100A8-S100A7-S100A6-S100A5-S100 A4- S100A3-S100A2-S100A1-D1S305-1qtel. These integrated physical, cytogenetic, and genetic mapping data will be useful for linkage analyses of diseases associated with region 1q21 and for the identification of novel genes and regulatory elements in the EDC.

Genes encoding structural proteins of epidermal cornification and S100 calcium-binding proteins form a gene complex ("epidermal differentiation complex") on human chromosome 1q21

Chromosome 1 reveals in region 1q21 a most remarkable density of genes that fulfill important functions in terminal differentiation of the human epidermis. These genes encode the cornified envelope precursors loricrin, involucrin, and small proline-rich proteins (SPRR1, SPRR2, and SPRR3), the intermediate filament-associated proteins profilaggrin and trichohyalin, and several S100A calcium-binding proteins. Extending and refining our previous physical map of 1q21 we have now mapped two additional S100A genes as well as the three SPRR subfamilies and resolved the arrangement of involucrin, SPRRs, and loricrin. All genes are linked within 1.9 Mbp of human genomic DNA in the order: S100A10, trichohyalin, profilaggrin, involucrin, SPRR3, SPRR1B, SPRR2A, loricrin, S100A9, S100A9, S100A8, S100A6. Colocalization of genes expressed late during maturation of epidermal cells together with genes encoding calcium-binding proteins is particularly intriguing since calcium levels tightly control the differentiation of epithelial cells and the expression of genes encoding epidermal structural proteins. Accounting for the close functional cooperation among these structurally and evolutionary related genes, we conclude that these loci constitute a gene complex, for which we propose the name epidermal differentiation complex.