Drosophila scavenger receptor CI is a pattern recognition receptor for bacteria

One hallmark of innate immunity apparently conserved from primitive life forms through to humans is the ability of the host to recognize pathogen-associated molecular patterns (PAMPs). Since macrophage pattern recognition receptors are not well defined in Drosophila, we set out to identify such receptors. Our findings reveal that Drosophila macrophages express multiple pattern recognition receptors and that the Drosophila scavenger receptor, dSR-CI, is one such receptor capable of recognizing both gram-negative and gram-positive bacteria, but not yeast. Our data indicate that scavenger receptor bacterial recognition is conserved from insects to humans and may represent one of the most primitive forms of microbial recognition.

Cloning of BNIP3h, a member of proapoptotic BNIP3 family genes

Apoptosis is regulated by interaction of antiapoptotic Bcl-2 family proteins with various proapoptotic proteins, several of which are also members of the Bcl-2 family. BNIP3 (formerly NIP3) is a proapoptotic mitochondrial protein classified in the Bcl-2 family based on limited sequence homology-3 (BH3) domain and COOH-terminal transmembrane domain. Sequence comparison of BNIP3 has indicated that there are several BNIP3 human homologs of this protein, like BNIP3L, Nix and BNIP3. We have cloned a new member of BNIP3 family from the cDNA library prepared from human dermal papilla cells and designated as BNIP3h. BNIP3h shows substantial homology with other BNIP3 family proteins. BNIP3h induced apoptosis from 24 hours after transfection in MCF7 cell lines and its apoptosis inducing activity is extended until 72 hours after transfection.

No deleterious mutations in the FOXJ1 (alias HFH-4) gene in patients with primary ciliary dyskinesia (PCD)

The transcription factor FOXJ1 (alias HFH-4 or FKHL13) of the winged-helix/forkhead family is expressed in cells with cilia or flagella, and seems to be involved in the regulation of axonemal structural proteins. The knockout mouse Foxj1(-/-) shows abnormalities of organ situs, consistent with random determination of left-right asymmetry, and a complete absence of cilia. The human FOXJ1 gene which maps to chromosome 17q, is thus an excellent candidate gene for Kartagener Syndrome (KS), a subphenotype of Primary Ciliary Dyskinesia (PCD), characterized by bronchiectasis, chronic sinusitis and situs inversus. We have collected samples from 61 PCD families, in 31 of which there are at least two affected individuals. Two families with complete aciliogenesis, and six families, in which the affected members have microsatellite alleles concordant for a locus on distal chromosome 17q, were screened for mutations in the two exons and intron-exon junctions of the FOXJ1 gene. No sequence abnormalities were observed in the DNAs of the affected individuals of the selected families. These results demonstrate that the FOXJ1 gene is not responsible for the PCD/KS phenotype in the families examined.

Axonemal beta heavy chain dynein DNAH9: cDNA sequence, genomic structure, and investigation of its role in primary ciliary dyskinesia

Dyneins are multisubunit protein complexes that couple ATPase activity with conformational changes. They are involved in the cytoplasmatic movement of organelles (cytoplasmic dyneins) and the bending of cilia and flagella (axonemal dyneins). Here we present the first complete cDNA and genomic sequences of a human axonemal dynein beta heavy chain gene, DNAH9, which maps to 17p12. The 14-kb-long cDNA is divided into 69 exons spread over 390 kb. The cDNA sequence of DNAH9 was determined using a combination of methods including 5' rapid amplification of cDNA ends, RT-PCR, and cDNA library screening. RT-PCR using nasal epithelium and testis RNA revealed several alternatively spliced transcripts. The genomic structure was determined using three overlapping BACs sequenced by the Whitehead Institute/MIT Center for Genome Research. The predicted protein, of 4486 amino acids, is highly homologous to sea urchin axonemal beta heavy chain dyneins (67% identity). It consists of an N-terminal stem and a globular C-terminus containing the four P-loops that constitute the motor domain. Lack of proper ciliary and flagellar movement characterizes primary ciliary dyskinesia (PCD), a genetically heterogeneous autosomal recessive disorder with respiratory tract infections, bronchiectasis, male subfertility, and, in 50% of cases, situs inversus (Kartagener syndrome, KS). Dyneins are excellent candidate genes for PCD and KS because in over 50% of cases the ultrastructural defects of cilia are related to the dynein complex. Genotype analysis was performed in 31 PCD families with two or more affected siblings using a highly informative dinucleotide polymorphism located in intron 26 of DNAH9. Two families with concordant inheritance of DNAH9 alleles in affected individuals were observed. A mutation search was performed in these two "candidate families," but only polymorphic variants were found. In the absence of pathogenic mutations, the DNAH9 gene has been excluded as being responsible for autosomal recessive PCD in these families.

Digital measurement of torsional eye movement due to postural change and its effect on reading performance

PURPOSE

Posture induced torsional eye movements have rarely been investigated. The current study made use of digital imaging technology to measure the cycloduction resulting from postural change. The effect of cycloduction on reading performance was also investigated.

METHODS

Thirty subjects were recruited and pictures of the right eye were captured using a digital camera at three postures, i.e. sitting, 90 degrees tilted to the right and 90 degrees tilted to the left. With the identification of a conjunctival landmark, torsional eye movement was measured. The subjects were then required to read a custom designed near chart while in those three postures, the reading card being rotated 90 degrees clockwise or 90 degrees anti-clockwise, to match with the tilting of the head. The reproducibility of the torsional eye movement and reading performance measure was determined in 12 of those 30 subjects.

RESULTS

Incycloduction was induced when tilting to the right and excycloduction when tilting to the left. This method was found to be reproducible with the 95% confidence limits of 0.80 degrees between visits. The mean incycloduction induced was 6.50 degrees (SD 1.51 degrees ) and 6.41 degrees (SD 1.46 degrees ) for excycloduction. No significant difference in amount was demonstrated (paired t-test: t = 0.624, P = 0.538). No significant difference was found in the reading scores at various postures (Repeated measures ANOVA: df = 2, F = 1.881, P = 0.162).

CONCLUSIONS

The results presented here demonstrate that we have developed an objective and instantaneous method with good precision, which could be applied in other studies that require the measurement of torsional eye movements. The induced cycloduction did not affect the reading performance.

A new family of adenylyl cyclase genes in the male germline of Drosophila melanogaster

We describe the cloning and characterization of a new gene family of adenylyl cyclase related genes in Drosophila. The five adenylyl cyclase-like genes that define this family are clearly distinct from previously known adenylyl cyclases. One member forms a unique locus on chromosome 3 whereas the other four members form a tightly clustered, tandemly repeated array on chromosome 2. The genes on chromosome 2 are transcribed in the male germline in a doublesex dependent manner and are expressed in postmitotic, meiotic, and early differentiating sperm. These genes therefore provide the first evidence for a role for the cAMP signaling pathway in Drosophila spermatogenesis. Expression from this locus is under the control of the always early, cannonball, meiosis arrest, and spermatocyte arrest genes that are required for the G2/M transition of meiosis I during spermatogenesis, implying a mechanism for the coordination of differentiation and proliferation. Evidence is also provided for positive selection at the locus on chromosome 2 which suggests this gene family is actively evolving and may play a novel role in spermatogenesis.

A locus for primary ciliary dyskinesia maps to chromosome 19q

Primary ciliary dyskinesia is an autosomal recessive condition characterised by chronic sinusitis, bronchiectasis, and subfertility. Situs inversus occurs in 50% of cases (Kartagener syndrome). It has an estimated incidence of 1 in 20 000 live births. The clinical phenotype is caused by defective ciliary function associated with a range of ultrastructural abnormalities including absent dynein arms, absent radial spokes, and disturbed ciliary orientation. The molecular genetic basis is unknown. A genome scan was performed in five Arabic families. Using GENEHUNTER, a maximal multipoint lod score (HLOD) of 4.4 was obtained on chromosome 19q13.3-qter at alpha (proportion of linked families) = 0.7. A 15 cM critical region is defined by recombinations at D19S572 and D19S218. These data provide significant evidence for a PCD locus on chromosome 19q and confirm locus heterogeneity.

Chinese tonal language rehabilitation following cochlear implantation in children

Cantonese language rehabilitation in 28 prelingually deaf children who underwent cochlear implantation was evaluated. All patients were implanted with multichannel devices and the operations went smoothly. They all had improved scores on audiological assessments and speech perception tests. The speech evaluation tests included the recognition of sounds, vowels, consonants and tone. Sentence recognition and story comprehension were both improved after training for 2 years. Cochlear implantation is a useful measure for the speech rehabilitation of prelingually profound deaf children when hearing aids are of no benefit. The multichannel implant device is of clinical significance in the rehabilitation of those patients using tonal language.

Primary ciliary dyskinesia: a genome-wide linkage analysis reveals extensive locus heterogeneity

Primary ciliary dyskinesia (PCD), or immotile cilia syndrome (ICS), is an autosomal recessive disorder affecting ciliary movement with an incidence of 1 in 20000-30000. Dysmotility to complete immotility of cilia results in a multisystem disease of variable severity with recurrent respiratory tract infections leading to bronchiectasis and male subfertility. Ultrastructural defects are present in ciliated mucosa and spermatozoa. Situs inversus (SI) is found in about half of the patients (Kartagener syndrome). We have collected samples from 61 European and North American families with PCD. A genome-wide linkage search was performed in 31 multiplex families (169 individuals including 70 affecteds) using 188 evenly spaced (19cM average interval) polymorphic markers. Both parametric (recessive model) and non-parametric (identity by descent allele sharing) linkage analyses were used. No major locus for the majority of the families was identified, although the sample was powerful enough to detect linkage if 40% of the families were linked to one locus. These results strongly suggest extensive locus heterogeneity. Potential genomic regions harbouring PCD loci were localised on chromosomes 3p, 4q, 5p, 7p, 8q, 10p, 11q, 13q, 15q, 16p, 17q and 19q. Linkage analysis using PCD families with a dynein arm deficiency provided 'suggestive' evidence for linkage to chromosomal regions 8q, 16pter, while analyses using only PCD families with situs inversus resulted in 'suggestive' scores for chromosomes 8q, and 19q.

PCR-based quantitation of Cryptosporidium parvum in municipal water samples

A PCR method for the quantitation of Cryptosporidium parvum oocysts in municipal drinking water samples was investigated. Quantitative PCR uses an internal standard (IS) template with unknown target numbers to compare to standards of known concentrations in a standard curve. The IS template was amplified using the same primers used to amplify a portion of a 358 bp gene fragment that encodes a repetitive oocyst wall protein in C. parvum. Municipal water samples spiked with known numbers of C. parvum oocysts were tested by quantitative PCR using the IS and the Digene SHARP Signal System Assay for PCR product detection. The absorbance readings for target DNA and IS templates versus the number of molecules of the target DNA were plotted to generate standard curves for estimating oocyst numbers. The method allowed the quantitation of oocysts from log 3 to log 5 spiked into municipal water samples.

[Allergy to squid and acari in a child]

Anaphylactic reactions after consumption of squid by patients sensitized to house dust mites have been reported several times.

CASE REPORT

A child allergic to dust mites developed an angioneurotic edema after eating squid. An immunoallergological assessment, including the prick test, labial test and IgE RAST revealed an allergy associated to both dust mites and squid.

CONCLUSIONS

In light of the potential seriousness of anaphylactic reactions, parents of children allergic to dust mites and these children should be made aware of the increased risk of allergies to squid that they may face.

The transcriptional activation domain of VP16 is required for efficient infection and establishment of latency by HSV-1 in the murine peripheral and central nervous systems

The herpes simplex virus (HSV) transactivator VP16 is a structural component of the virion that activates immediate-early viral gene expression. The HSV-1 mutant in1814, which contains a 12-bp insertion that compromises the transcriptional function of VP16, replicated to a low level if at all in the trigeminal ganglia of mice (I. Steiner, J. G. Spivack, S. L. Deshmane, C. I. Ace, C. M. Preston, and N. W. Fraser (1990). J. Virol. 64, 1630-1638; Valyi-Nagy et al., unpublished data). However, in1814 did establish a latent infection in the ganglia after corneal inoculation from which it could be reactivated. In this study, several HSV-1 strains were constructed with deletions in the VP16 transcriptional activation domain. These viruses were viable in cell culture, although some were significantly reduced in their ability to initiate infection. A deletion mutant completely lacking the activation domain of VP16 (RP5) was unable to replicate to any detectable level or to efficiently establish latent infections in the peripheral and central nervous systems of immunocompetent mice. However, similar to in1814, RP5 formed a slowly progressing persistent infection in immunocompromised nude mice. Thus RP5 is severely neuroattenuated in the murine model of HSV infection. However, the activation domain of VP16 is not essential for replication in the nervous system, since we observed a slow progressive infection persisting in the absence of an immune response.

Mutations in the gene encoding the human matrix Gla protein cause Keutel syndrome

Keutel syndrome (KS, MIM 245150) is an autosomal recessive disorder characterized by abnormal cartilage calcification, peripheral pulmonary stenosis and midfacial hypoplasia. A genome search using homozygosity mapping provided evidence of linkage to chromosome 12p12.3-13.1 (maximum multipoint lod score, 4.06). MGP was a candidate on the basis of its localization to this chromosomal region and the known function of its protein. MGP maps to chromosome 12p near D12S363. Human MGP is a 10-kD skeletal extracellular matrix (ECM) protein that consists of an 84-aa mature protein and a 19-aa transmembrane signal peptide. It is a member of the Gla protein family, which includes osteocalcin, another skeletal ECM protein, and a number of coagulation factors (factors II, VII, IX, X and proteins S and C). All members of this family have glutamic acid residues modified to gamma-carboxyglutamic acids (Gla) by a specific gamma-carboxylase using vitamin K as a cofactor. The modified glutamic acid residues of Gla proteins confer a high affinity for mineral ions such as calcium, phosphate and hydroxyapatite crystals, the mineral components of the skeletal ECM. The pattern and tissue distribution of Mgp expression in mice suggest a role for Mgp in regulating ECM calcification. Mglap-deficient mice (Mglap-/-) have been reported to have inappropriate calcification of cartilage. Mutational analysis of MGP in three unrelated probands identified three different mutations: c.69delG, IVS1-2A-->G and c.113T-->A. All three mutations predict a non-functional MGP. Our data indicate that mutations in MGP are responsible for KS and confirm its role in the regulation of extracellular matrix calcification.

Mass spectrometric and thermodynamic studies reveal the role of water molecules in complexes formed between SH2 domains and tyrosyl phosphopeptides

BACKGROUND

SH2 domains have a fundamental role in signal transduction. These domains interact with proteins containing phosphorylated tyrosine residues and, in doing so, mediate the interactions of proteins involved in tyrosine kinase signalling. The issue of specificity in SH2 domain interactions is therefore of great interest in terms of understanding tyrosine kinase signal-transduction pathways and in the discovery of drugs to inhibit them. Water molecules are found at the interfaces of many complexes, however, to date little attention has been paid to their role in dictating specificity.

RESULTS

Here we use a combination of nanoflow electrospray ionization mass spectrometry (ESI-MS), isothermal titration calorimetry and structural data to investigate the effect of water molecules in complexes formed between the SH2 domain of tyrosine kinase Src and tyrosyl phosphopeptides. Binding studies have been performed using a series of different peptides that were selected to allow changes in the water content at the complex interface and demonstrate changes in specificity. ESI-MS enables quantification of the number of water molecules that interact with a higher affinity than those generally found solvating the biomolecular complex.

CONCLUSIONS

Comparing the interactions of different peptides, we show that an intricate network of water molecules have a key role in dictating specificity. The use of mass spectrometry to quantify tightly bound water molecules may prove of general use in structural biology, where an independent determination of the water molecules associated with a structure would be advantageous. Furthermore, the ability to assess whether given water molecules are important in high-affinity binding could make this method a precious tool in drug design.

Ginsenoside Rg1 down-regulates glucocorticoid receptor and displays synergistic effects with cAMP

Ginsenoside-Rg1 (G-Rg1) from the roots of Panax ginseng C. A. Meyer has been shown to bind to the glucocorticoid receptor (GR). To further explore the effect of G-Rg1 binding to GR, a luciferase reporter gene containing two copies of a glucocorticoid response element was constructed and transiently transfected into FTO2B rat hepatoma cells. A dose-dependent induction of the reporter gene was observed in response to G-Rg1, and the inductive effect was blocked by treatment with the antiglucocorticoid RU486. In addition, both G-Rg1- and dexamethasone (Dex)-induced transcription was synergistically enhanced by the treatment of dibutyryl cAMP (Bt2-cAMP). G-Rg1 treatment also led to the down-regulation of intracellular GR content, which was similar to the effect of Dex. By showing that G-Rg1 down-regulates GR and induces GR-mediated transcription synergistically with cAMP, we conclude that G-Rg1 is a functional GR ligand in FTO2B cells.

The expression of a novel, epithelium-specific ets transcription factor is restricted to the most differentiated layers in the epidermis

Ets proteins have been implicated in the regulation of gene expression during a variety of biological processes, including growth control, differentiation, development and transformation. More than 35 related proteins containing the 'ets domain' have now been found which specifically interact with DNA sequences encompassing the core tetranucleotide GGAA. Although ets responsive genes have been identified in the epidermis, little is known about their distribution and function in this tissue. We have now demonstrated that epidermis and cultured epidermal keratinocytes synthesize numerous ets proteins. The expression of some of these proteins is regulated as a function of differentiation. Among these is a novel ets transcription factor with a dual DNA-binding specificity, which we have called jen. The expression of jen is not only epithelial specific, but it is the only ets protein so far described, and one of the very few transcription factors whose expression is restricted to the most differentiated epidermal layers. We show that two epidermal marker genes whose expression coincides with that of jen are transregulated by this protein in a complex mode which involves interactions with other transcriptional regulators such as Sp1 and AP1.

Ginsenoside-Rg1, one of the major active molecules from Panax ginseng, is a functional ligand of glucocorticoid receptor

We have examined the possibility that a component of Panax ginseng, ginsenoside-Rg1 (G-Rg1), acts by binding to the glucocorticoid receptor (GR). G-Rg1 competed for [3H]dexamethasone (Dex) binding to GR with a specific affinity of 1-10 microM and activated a glucocorticoid responsive element-containing luciferase reporter gene. The dose-dependence patterns of G-Rg1 and Dex for these two effects were nearly identical, although two to three orders of magnitude higher concentration of G-Rg1 than that of Dex was required for the same magnitude of response. At the cellular level, the growth of FT02B cells was suppressed by G-Rg1 as well as by Dex, each of whose effects were abolished by RU486. These results demonstrate that G-Rg1 is a functional ligand of GR.

A novel human ERK phosphatase regulates H-ras and v-raf signal transduction

A cDNA encoding a novel human extracellularly-regulated kinase (ERK) phosphatase, designated B59, was isolated from a B5/589 human mammary epithelial cell cDNA library. The 1104 nucleotide open reading frame encodes 368 amino acids including the highly conserved catalytic site sequence of protein phosphotyrosine phosphatases (PTPs), VXVHCXXGXXR, at amino acid position 276-287. The predicted 70 amino acid stretch surrounding the HC motif shares significant sequence identity with other human dual specificity PTPs (dsPTPs), including the known ERK PTPs CL100, PAC1, B23, as well as the dsPTPs VH-1 and VHR. B59 protein synthesized in vitro in a rabbit reticulocyte lysate dephosphorylated rat ERK1 and ERK2 proteins whose phosphorylation had been stimulated by v-mos kinase added to the lysate. Ectopic expression of B59 in NIH3T3 fibroblasts inhibited the induction of an oncogene-responsive promoter by the dominant-activating raf mutant, raf-BXB. Moreover, cotransfection of NIH3T3 cells with B59 inhibited morphological transformation by H-ras and v-raf oncogenes. These results suggest that B59 suppresses the transforming activity of H-ras or v-raf oncogenes through ERK dephosphorylation and inactivation.

The nucleotide sequence of Saccharomyces cerevisiae chromosome V

Here we report the sequence of 569,202 base pairs of Saccharomyces cerevisiae chromosome V. Analysis of the sequence revealed a centromere, two telomeres and 271 open reading frames (ORFs) plus 13 tRNAs and four small nuclear RNAs. There are two Tyl transposable elements, each of which contains an ORF (included in the count of 271). Of the ORFs, 78 (29%) are new, 81 (30%) have potential homologues in the public databases, and 112 (41%) are previously characterized yeast genes.

The nucleotide sequence of Saccharomyces cerevisiae chromosome XVI

The nucleotide sequence of the 948,061 base pairs of chromosome XVI has been determined, completing the sequence of the yeast genome. Chromosome XVI was the last yeast chromosome identified, and some of the genes mapped early to it, such as GAL4, PEP4 and RAD1 (ref. 2) have played important roles in the development of yeast biology. The architecture of this final chromosome seems to be typical of the large yeast chromosomes, and shows large duplications with other yeast chromosomes. Chromosome XVI contains 487 potential protein-encoding genes, 17 tRNA genes and two small nuclear RNA genes; 27% of the genes have significant similarities to human gene products, and 48% are new and of unknown biological function. Systematic efforts to explore gene function have begun.

Ginsenoside-Rh2 blocks the cell cycle of SK-HEP-1 cells at the G1/S boundary by selectively inducing the protein expression of p27kip1

The mechanism of action by which ginsenoside-Rh2 (G-Rh2) suppresses the proliferation of SK-HEP-1 cells is reported. The results from flow cytometric analyses show that G-Rh2 arrested the cell cycle at the G1/S transition phase. The cyclin E-dependent kinase activity which had been immunoprecipitated with cyclin E-specific antibody was down-regulated in the cells in response to G-Rh2. The IC50 value required to down-regulate the kinase activity by 50% was approximately 0.75 microM. Immunoblotting analyses show that G-Rh2 selectively induced the expression of p27kip1 in a dose-dependent manner whereas it had no effect on the levels of cyclin E, cdk2, and p21WAF1. In addition, our data show that G-Rh2 reduced the protein levels of cdc25A at doses higher than 10 microM. Collectively, these data suggest that ginsenoside-Rh2 arrests the cell cycle at the G1/S transition phase by selectively inducing protein expression of p27Kip1 and, as a consequence, down-regulating cyclin E-dependent kinase activity.

A novel splice-site mutation in the gamma subunit of the epithelial sodium channel gene in three pseudohypoaldosteronism type 1 families

Pseudohypoaldosteronism type 1 (PHA1, OMIM 264350) is an uncommon inherited disorder characterized by salt-wasting and end-organ unresponsiveness to mineralocorticoids. A complete genome search using homozygosity mapping in eleven consanguineous families with PHA1 provided conclusive evidence of linkage with heterogeneity. The disease locus mapped to chromosome 16p12.2-13.11 in six families and to 12p13.1-pter in the other five families. These two chromosomal regions harbour the genes encoding the three subunits of the human amiloride sensitive epithelial sodium channel (hENaC): SCNN1B and SCNN1G on 16p and SCNN1A on 12p. Our linkage results have been further supported by the recent report of mutations in the alpha and beta subunit genes in PHA1 patients. We now report the identification of a 3' splice site mutation in SCNN1G (318-1 G-->A) in three families showing linkage to 16p. Abnormal splicing results with the production of two messenger RNAs, one arising from activation of an adjacent cryptic splice site and the other from skipping of the downstream exon. The two corresponding mutant gamma hENaC subunits are predicted to have three highly conserved amino acids in the extracellular domain replaced by a novel amino acid (KYS106-108-->N) and truncation from 649 to 134 amino acids respectively. These three families all originate from the Indian sub-continent and the probands have severe generalized PHA. They share a common haplotype which suggests the presence of a founder mutation in this sub-population.

Splenectomy in cancer surgery: diminishing indications?

The diminishing enthusiasm towards performing splenectomy (SPL) either as an integral part of surgical cancer management (SCM), or for staging/management (ST) of lymphoma, warranted our assessment of the extent of this trend in a minority population. We retrospectively analysed all SPL submitted to Surgical Pathology for histological processing over a 24-year period (1/1/70-12/31/93) at the Howard University Hospital, a predominantly African-American institution. Of the 446 SPL performed during the period, sixty-nine (15.5%) were performed as part of SCM/ST. Seventy-five per cent (52/69) were for solid intra-abdominal cancers (SIC) and 25% (17/69) for lymphoma. As a group, the patients were older, 71% over 40 years old) and showed a male predominance (61% males). Sixty-two per cent (43/69) of the SPL were performed in the decade 1970-1979. In the following decade 1980-1989, the frequency with which SPL was performed, had dropped to 33% (23/69). Four years into the current decade, 1990-1993, only 5% (3/69) of the SPL were performed for SCM/ST. These findings suggest that in African-Americans, the performance of SPL in ST/SCM has been declining over the years, which is in agreement with the current growing trends in cancer treatment i.e. to avoid unnecessary operations, limit morbidity, preserve important organs, maintain immunocompetence of the patient and to utilize advanced imaging techniques in ST/SCM.

CO2 and Nd:YAG laser-induced pulmonary parenchymal lung injury in a rabbit model

Laser exposure of the pulmonary parenchyma during treatment of emphysema and other clinical indications causes acute lung injury. Animal investigations are needed to understand and control laser-induced lung injury. We hypothesized that lung injury is deeper from Nd:YAG laser exposures than CO2 exposures because of deeper penetration of Nd:YAG wavelength light. We compared the temporal evolution of histologic injury in rabbits resulting from continuous mode shallow CO2 and Nd:YAG laser pulmonary parenchymal exposures applied in rabbits. Forty-six New Zealand white (NZW) rabbits underwent treatment with CO2 laser (n=18), Nd:YAG laser (n=18), or sham thoracotomy control (n=10) to the visceral pleural surface using 1 min of exposure (5 watts, defocused to 70 W/cm2 power density for both lasers). Animals were killed at 0, 4, 7, 21, and 49 d after exposure. Lung injury, similar to that seen clinically in humans, developed in all laser-treated animals. Injury progressed from ischemia and vascular congestion, to edema and necrosis, followed by pleural and parenchymal fibrosis. The acute injury was qualitatively distinct and slightly deeper in CO2 than Nd:YAG-treated animals (p<0.02) despite the shallower depth of penetration of the CO2 laser. These findings may imply that higher absorption coefficient for CO2 laser energy results in greater focal temperatures and injury in the areas of direct exposure, and suggest that Nd:YAG laser exposure at these settings may cause shallower injury than CO2 lasers in humans undergoing clinical treatment.

Localisation of pseudohypoaldosteronism genes to chromosome 16p12.2-13.11 and 12p13.1-pter by homozygosity mapping

Pseudohypoaldosteronism type 1 (PHA1, OMIM 264350) is a rare Mendelian disorder characterised by end-organ unresponsiveness to mineralocorticoids. Most steroid hormone insensitivity syndromes arise from mutations in the corresponding receptor, but available genetic evidence is against involvement of the mineralocorticoid receptor gene, MLR, in PHA1. A complete genome scan for PHA1 genes was undertaken using homozygosity mapping in 11 consanguineous families. Conclusive evidence of linkage with heterogeneity was obtained with a maximum two-locus admixture lod score of 9.9. The disease locus mapped to chromosome 16p12.2-13.11 in six families and to 12p13.1-pter in the other five families. The two chromosomal regions harbour genes for subunits of the amiloride-sensitive epithelial sodium channel: SCNN1B and SCNN1G on 16p and SCNN1A on 12p. Liddle's syndrome of hypertension and pseudoaldosteronism has been shown to arise from mutations in SCNN1B and SCNN1G. These results strongly suggest that PHA1 and Liddle's syndrome are allelic variants caused by mutations in genes encoding subunits of this sodium channel. These genes are of broad biological interest both in relation to sodium and water homeostasis in mammals and by virtue of their homology to the mec genes of Caenorhabditis elegans involved in mechanosensitivity and neuronal degeneration.

Genetic evidence for the neuronal nitric oxide synthase gene (NOS1) as a susceptibility locus for infantile pyloric stenosis

The etiological role of the gene for neuronal nitric oxide synthase (NOS1) in infantile pyloric stenosis (PS) was investigated by analysis of two intragenic polymorphisms (NOS1a and NOS1b) in 27 families. There was significant overall transmission disequilibrium between PS and NOS1a (P = .006). Consideration of each allele independently revealed a highly significant tendency for allele 7 (210 bp) to be preferentially transmitted to the affected offspring (P = .0006). These observations suggest that NOS1 is a susceptibility locus for PS.

Exclusion of the locus for autosomal recessive pseudohypoaldosteronism type 1 from the mineralocorticoid receptor gene region on human chromosome 4q by linkage analysis

Pseudohypoaldosteronism type 1 (PHA1) is an uncommon inherited disorder characterized by salt-wasting in infancy arising from target organ unresponsiveness to mineralocorticoids. Clinical expression of the disease varies from severely affected infants who may die to apparently asymptomatic individuals. Inheritance is Mendelian and may be either autosomal dominant or autosomal recessive. A defect in the mineralocorticoid receptor has been implicated as a likely cause of PHA1. The gene for human mineralocorticoid receptor (MLR) has been cloned and physically mapped to human chromosome 4q31.1-31.2. The etiological role of MLR in autosomal recessive PHA1 was investigated by performing linkage analysis between PHA1 and three simple sequence length polymorphisms (D4S192, D4S1548, and D4S413) on chromosome 4q in 10 consanguineous families. Linkage analysis was carried out assuming autosomal recessive inheritance with full penetrance and zero phenocopy rate using the MLINK program for two-point analysis and the HOMOZ program for multipoint analysis. Lod scores of less than -2 were obtained over the whole region from D4S192 to D4S413 encompassing MLR. This provdes evidence against MLR as the site of mutations causing PHA1 in the majority of autosomal recessive families.

Inferior outcome of two-haplotype matched renal transplants in blacks: role of early rejection

Acute rejection in the early post-transplant period is a major determinant of long-term outcome. A cohort analysis was performed to evaluate the race-specific incidence rates of early acute rejection episodes (AR) and delayed graft function (DGF) in Americans of African (blacks) and European (whites) descent (N = 2565) who received a 2-HM living-related donor (LRD) first kidney transplant between 1984 and 1992. After adjusting for center and recipient characteristics, blacks had a higher incidence of AR during the initial transplant hospitalization (blacks 13.2% vs. whites 7.4%, OR = 1.64, P = 0.02). DGF also occurred more frequently in blacks (unadjusted OR = 1.58, P = 0.07). Blacks with AR had significantly worse Cox-adjusted five year graft survival than similarly affected whites (blacks 50% vs. whites 76%, P < 0.01). We conclude that failure to take immunosuppressive medications cannot be implicated as a cause of the higher incidence of AR during the initial transplant hospitalization in black kidney transplant recipients. The excess risk of AR in blacks may reflect previously reported intrinsic differences in immune responsiveness and/or pharmacokinetics of immunosuppressive agents. The profound deleterious effect of AR appears to be largely responsible for the accelerated rate of late graft loss in African Americans.

Diminished virulence of a sar-/agr- mutant of Staphylococcus aureus in the rabbit model of endocarditis

Microbial pathogenicity in Staphylococcus aureus is a complex process involving a number of virulence genes that are regulated by global regulatory systems including sar and agr. To evaluate the roles of these two loci in virulence, we constructed sar-/agr- mutants of strains RN6390 and RN450 and compared their phenotypic profiles to the corresponding single sar- and agr- mutants and parents. The secretion of all hemolysins was absent in the sar-/agr- mutants while residual beta-hemolysin activity remained in single agr- mutants. The fibronectin binding capacity was significantly diminished in both single sar- mutants and double mutants when compared with parents while the reduction in fibrinogen binding capacity in the double mutants was modest. In the rabbit endocarditis model, there was a significant decrease in both infectivity rates and intravegetation bacterial densities with the double mutant as compared to the parent (RN6390) at 10(3)-10(6) CFU inocula despite comparable levels of early bacteremia among various challenge groups. Notably, fewer bacteria in the double mutant group adhered to valvular vegetations at 30 min after challenge (10(6) CFU) than the parent group. These studies suggest that both the sar and agr loci are involved in initial valvular adherence, intravegetation persistence and multiplication of S. aureus in endocarditis.

Linkage analysis of idiopathic generalised epilepsy in families of probands with Juvenile Myoclonic Epilepsy and marker loci in the region of EPM 1 on chromosome 21 q: Unverricht-Lundborg disease and JME are not allelic variants

The locus for Unverricht-Lundborg disease, EPM 1, has recently been mapped to chromosome 21q22.3. A locus, EJM 1, predisposing to idiopathic generalised epilepsy in families of probands with juvenile myoclonic epilepsy has been localised to chromosome 6p by evidence of linkage to the HLA region. However, segregation analysis suggests a two-locus model for JME and evidence has been obtained for genetic heterogeneity within the JME/IGE phenotype. EPM 1 was therefore investigated as a candidate locus in the set of families segregating for IGE and JME which do not show linkage to markers on chromosome 6p. Linkage analysis was carried out in 25 families using three microsatellite DNA markers around the EPM 1 gene region using different models of inheritance. Multipoint linkage analysis provided definite exclusion for 20cM around PFKL, the closet linked marker to EPM 1, under three out of four models tested. These results strongly suggest that the EPM 1 gene is not linked to the phenotype expressed in these families, and therefore that Unverricht-Lundborg disease and juvenile myoclonic epilepsy are not allelic variants.

Linkage analysis of idiopathic generalized epilepsy (IGE) and marker loci on chromosome 6p in families of patients with juvenile myoclonic epilepsy: no evidence for an epilepsy locus in the HLA region

Evidence for a locus (EJM1) in the HLA region of chromosome 6p predisposing to idiopathic generalized epilepsy (IGE) in the families of patients with juvenile myoclonic epilepsy (JME) has been obtained in two previous studies of separately ascertained groups of kindreds. Linkage analysis has been undertaken in a third set of 25 families including a patient with JME and at least one first-degree relative with IGE. Family members were typed for eight polymorphic loci on chromosome 6p: F13A, D6S89, D6S109, D6S105, D6S10, C4B, DQA1/A2, and TCTE1. Pairwise and multipoint linkage analysis was carried out assuming autosomal dominant and autosomal recessive inheritance and age-dependent high or low penetrance. No significant evidence in favor of linkage was obtained at any locus. Multipoint linkage analysis generated significant exclusion data (lod score < -2.0) at HLA and for a region 10-30 cM telomeric to HLA, the extent of which varied with the level of penetrance assumed. These observations indicate that genetic heterogeneity exists within this epilepsy phenotype.

Linkage analysis of infantile pyloric stenosis and markers from chromosome 9q11-q33: no evidence for a major gene in this candidate region

A genetic component in the aetiology of infantile pyloric stenosis (PS) is well established. Segregation analysis is compatible with a multifactorial sex modified threshold model of inheritance but a major gene of low penetrance has not been excluded. PS has been reported to occur in 57% (four of seven) of cases with duplication of chromosome 9q11-q33. Twenty families with PS were studied using genetic markers at loci D9S55, D9S111, D9S15, D9S12, D9S56, D9S59, and ASS from this region of chromosome 9. Pairwise lod scores of -2 were obtained with all these markers at recombination fractions greater or equal to 0.04 under both autosomal dominant and autosomal recessive models of inheritance. This provides evidence against the existence of a major locus predisposing to PS within chromosome 9q11-q33.

The NF-kappa B p65 promoter

The promoter of the human gene encoding the p65 subunit of the transcription factor NF-kappa B was cloned and the nucleotide sequence determined. The p65 promoter lacks both TATA and CCAAT consensus sequences. The p65 promoter contains three consensus binding sites of the transcription factor SP1. In contrast to the promoter of the p50 subunit of NF-kappa B, no sequences predicted to bind NF-kappa B are present in the p65 promoter. Phorbol ester (PMA) and phytohemagglutinin (PHA) treatment of Jurkat cells did not activate the p65 promoter in transient transfection experiments. Using different deletion mutants of the p65 promoter, essential promoter elements were mapped.

Effect of anterior mandibular positioning on obstructive sleep apnea

This prospective case report series utilized an anterior mandibular positioning (AMP) device on obstructive sleep apnea (OSA) patients and evaluated the changes in the respiratory disturbance index (RDI) and subjective overall satisfaction with the treatment. The RDI was based on all-night polysomnographic studies performed before and after approximately 4 months of appliance use. Overall satisfaction with the treatment was rated using a Likert scale (0 to 10) after 6, 18, and 36 months of AMP device use. Although only 15 of the 24 subjects agreed to undergo post-appliance polysomnograms, 14 of the 15 subjects showed a clear decrease in the RDI. The effect on the other subjects is unknown, but even if the 9 subjects without polysomnograms had no change in the RDI from the AMP device, a minimum rate of 58% of the subjects (14 of 24) would have substantially improved the RDI at the 3-month time point. Of the 24 subjects, 2 subjects claimed no immediate benefit and stopped using the device, 4 subjects were lost to followup, 1 subject lost weight and stopped using the device, 1 subject had mandibular advancement surgery after using the appliance for a period of time, and 3 stopped using the appliance because of persistent temporomandibular pain problems. The remaining 12 of the 23 (52%) original subjects were still using the appliance successfully at 36 months. One subject died of non-apnea-related causes before the 18-month follow-up time point. The 16 subjects who responded at 36 months reported a mean overall satisfaction with treatment of 6.9 +/- 3.3 on a scale of 10.

Spontaneous intracerebral hemorrhage: a very late delayed effect of radiation therapy

Cerebral necrosis is a well-known delayed sequela of radiation to the central nervous system. Delayed intracerebral hemorrhage occurring several years after radiation is rare; however, with increased survival, this complication will become more common. We report a child who developed a brain-stem hemorrhage 4.5 years following radiation therapy for brainstem tumor. The possible pathogenesis for the spontaneous hemorrhage is discussed. The onset of the neurologic symptoms in this setting occurs later than the usual symptoms of radiation necrosis. It is important to recognize this entity as a late delayed complication of radiation therapy and not to mistake it for tumor recurrence.

Acetyl-levo-carnitine protects against MPTP-induced parkinsonism in primates

Acetyl-levo-carnitine (ALC) protects against 1-methyl, 4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced toxicity in the nonhuman primate. ALC pretreated monkeys do not show signs of parkinsonism or electroretinographic changes typical of dopaminergic deficiency when given MPTP. In addition, pilot neurochemical and morphological data confirm a partial protection effect. While MAO-B inhibitors, like L-Deprenyl, are thought to protect dopaminergic neurons from MPTP-induced cell death by preventing the conversion of MPTP to its toxic metabolite MPP+, ALC is not known to have MAO-B affinity. Converging evidence suggests that ALC may affect directly mitochondrial respiration, which is known to be the target of MPP+ and affected in human neurodegenerative diseases, including Parkinson's disease. The results of this study point to new therapeutic avenues for the treatment of these nosologic entities.

Platelet monoamine oxidase in Parkinson patients: effect of L-deprenyl therapy

Platelet MAO activity was measured in 79 Parkinson patients (56 males and 23 females) before and during L-deprenyl therapy. Baseline platelet MAO activity was higher in females than in males with no age dependent differences. During chronic L-deprenyl therapy, MAO activity was inhibited greater than 98%. Four hours after the oral administration of the first 5 mg dose of L-deprenyl, platelet MAO activity was inhibited by 86%. By 24 hours, greater than 98% inhibition was achieved and this degree of inhibition was maintained during continuous L-deprenyl administration. Following oral administration of 10 mg L-deprenyl once a day versus 5 mg L-deprenyl twice a day, the time course of platelet MAO inhibition was similar. Five days after the termination of chronic L-deprenyl therapy, platelet MAO activity was still inhibited by 96%. MAO activity returned to normal by 2 weeks after stopping L-deprenyl. Platelet MAO activity is a useful method of monitoring bioavailability, compliance, dose-response relationship and optimal dosage schedules for L-deprenyl in Parkinson patients.

Regional distribution of calcium/calmodulin-dependent phosphatase activity of calcineurin in rat brain

The regional distribution of calcineurin activity (measured using p-nitrophenyl-phosphate which detects the phospho-tyrosylphosphatase activity of calcineurin) shows that the striatum, hippocampus and cerebral cortex contains high calcineurin activity. Within the striatum, calcineurin activity does not appear to be present in dopaminergic terminals, since lesions of the nigro-striatal dopaminergic pathway (which reduce striatal dopamine levels by 97%) had no effect on calcineurin activity. On the other hand, kainic acid, which destroys neurons whose perikarya are in the striatum, reduced calcineurin activity by 86% indicating that calcineurin activity is localized in striatal intrinsic neurons. Calcineurin apparently does not exist in glia, since glial cells actually proliferate in kainic acid lesioned striatal tissues.

Age-dependent changes in brain glycine concentration and strychnine-induced seizures in the rat

Glycine levels and receptor binding were measured in the medulla and spinal cord of 2-month, 10-month, and 24-month-old Fischer 344 rats. The behavioral response to the administration of the glycine antagonist, strychnine, was also evaluated in 2- and 24-month-old animals to investigate the relevance of these parameters to the susceptibility to seizures. Significant reductions in glycine in both the spinal cord and medulla occurred from 2 to 24 months of age. The glycine precursors, serine and threonine, were decreased only in the spinal cord. [3H]Strychnine binding was also decreased by 38% and 34% in the medulla and spinal cord, respectively, of 24-month-old rats compared to 2-month-olds. [3H]GABA binding was similarly reduced while no age-related changes in [3H]diazepam binding in the spinal cord were detected. Comparison of 2- and 24-month-old animals after systemic injection of 1.75 mg/kg strychnine showed that senescent animals have a higher incidence of seizures and mortality compared to young animals. Decreases in glycinergic neurotransmission may lower strychnine seizure threshold in the aged animal.

Strychnine seizure potentiation by azaspirodecanedione anxiolytics in rats

Buspirone, gepirone and ipsaperone administered intraperitoneally (40 mg/kg) to naive rats were found to be proconvulsive for strychnine-induced seizures. The dose of strychnine required to induce seizures in 50% of test animals (CD50) was 2.18 mg/kg in naive rats, while CD50s for rats treated with the azaspirodecanediones ipsaperone, gepirone and buspirone were 1.65, 0.97 and 0.70 mg/kg respectively. Azaspirodecanediones have high affinity for the 5-HT1A serotonin receptor, however, the specific 5-HT1A agonist, 8-hydroxy-2-(di-n-propyl-amino)-tetralin (8-OH-DPAT) had no effect on strychnine seizure in naive rats (CD50 = 2.0 mg/kg). The strychnine specific proconvulsive effects of inferior olive lesions and buspirone were additive, resulting in a CD50 of 0.1 mg/kg. This observation indicates that the buspirone-induced decrease in strychnine seizure threshold does not require intact inferior olive-climbing fiber pathways. Cerebellar sites for possible azaspirodecanedione action are discussed.

Systemic 1-methyl,4-phenyl,1-2-3-6-tetrahydropyridine (MPTP) administration decreases retinal dopamine content in primates

Following MPTP administration, 4 Cynomolgus monkeys developed a parkinsonian syndrome, accompanied by specific changes of both pattern visual evoked potential and electroretinogram. Retinal dopamine and dihydroxyphenylacetic acid contents were measured in the 4 MPTP-treated monkeys and in 3 normal monkeys. Dopamine and dihydroxyphenylacetic acid levels were significantly lower in the retinas of the MPTP-treated animals (p less than 0.001), suggesting that dopamine has a specific function in the visual system of primates.

Ca2+/calmodulin-dependent phosphoprotein phosphatase activity of calcineurin in rat striatum: effect of kainic acid lesions

Calcineurin, a Ca2+ and calmodulin (CM)-dependent phosphatase, has been shown to be present in high concentrations in the striatum. Using inhibitor-1(phosphorylated by cAMP-dependent protein kinase) as a substrate, we found Ca2+/CM-dependent phosphatase (calcineurin) to be more than 2-fold higher than non-Ca2+/CM-dependent phosphatase in the rat striatum. In order to determine the cellular localization of calcineurin, striatal kainic acid injections were used to destroy neurons whose cell bodies are present at the site of injection. Glutamic acid decarboxylase (GAD) activity was measured as an indicator of destruction of striatal GABA-ergic neurons. After intrastriatal injection of 1 and 2 ug of kainic acid, there was a significant decrease of both calcineurin and GAD. However, injection of 0.5 ug kainic acid into the striatum reduced GAD activity by 81%, but had no effect on calcineurin phosphatase activity. Thus calcineurin does not appear to be equally distributed among all types of striatal neurons, but rather may be concentrated in neurons that are less sensitive to kainic acid than the GABA-ergic neuron.