Osteoblastic cells regulate the haematopoietic stem cell niche

Stem cell fate is influenced by specialized microenvironments that remain poorly defined in mammals. To explore the possibility that haematopoietic stem cells derive regulatory information from bone, accounting for the localization of haematopoiesis in bone marrow, we assessed mice that were genetically altered to produce osteoblast-specific, activated PTH/PTHrP receptors (PPRs). Here we show that PPR-stimulated osteoblastic cells that are increased in number produce high levels of the Notch ligand jagged 1 and support an increase in the number of haematopoietic stem cells with evidence of Notch1 activation in vivo. Furthermore, ligand-dependent activation of PPR with parathyroid hormone (PTH) increased the number of osteoblasts in stromal cultures, and augmented ex vivo primitive haematopoietic cell growth that was abrogated by gamma-secretase inhibition of Notch activation. An increase in the number of stem cells was observed in wild-type animals after PTH injection, and survival after bone marrow transplantation was markedly improved. Therefore, osteoblastic cells are a regulatory component of the haematopoietic stem cell niche in vivo that influences stem cell function through Notch activation. Niche constituent cells or signalling pathways provide pharmacological targets with therapeutic potential for stem-cell-based therapies.

Organization of intrahippocampal projections originating from CA3 pyramidal cells in the rat

The distribution of intrahippocampal projections arising from the CA3 region of the rat hippocampus was investigated using in vitro and in vivo methods. In the in vitro hippocampal slice preparation, single CA3 pyramidal cells were intracellularly labeled with horseradish peroxidase (HRP), and the three-dimensional organization of the axonal plexus was analyzed by using a computer-aided digitizing system. As many as eight primary collaterals originated from the principal axon of CA3 pyramidal cells and these commonly bifurcated further and innervated stratum oriens and stratum radiatum of CA3 and CA1. Within the 400 microns slice, the summed length of all visible collaterals per neuron ranged from 2.6 mm to approximately 12.5 mm. While the CA3 principal axon tended to be relatively smooth, the axonal collaterals bore numerous varicosities that electron microscopy confirmed to be presynaptic boutons. These varicosities occurred, on average, once every 7 microns of collateral length. The distribution of axonal collaterals differed depending on the location of the parent pyramidal cell. Only rarely could CA3 collaterals be followed in the slice to their terminations within CA1. To study the topographic organization of CA3 projections both to other levels of CA3 and to CA1, the anterograde tracer, Phaseolus vulgaris leucoagglutinin (PHA-L) was injected into various transverse and septotemporal levels of CA3. Immunohistochemical visualization of the lectin was conducted in dissected and "extended" hippocampi to facilitate analysis of the topographic distribution of projections along the long or septotemporal axis. Projections from all portions of CA3 reached widespread regions of CA3, CA2, and CA1, but only a few fibers entered the subicular complex and there were no projections to the entorhinal cortex. There were also some CA3 and CA2 projections to the hilus of the dentate gyrus, but these did not enter the granule cell or molecular layers. The CA3 projections to CA1 were organized according to several distinctive and consistent gradients that can generally be summarized as follows. 1. CA3 cells located close to the dentate gyrus (proximal CA3), while projecting both septally and temporally, tended to project more heavily to levels of CA1 located septal to the injection site. CA3 cells located closer to CA1, in contrast, projected more heavily to levels of CA1 located temporally to the injection site. 2. At, or close to, the septotemporal level of the injection, cells located proximally in CA3 gave rise to collaterals that tended to terminate more superficially in stratum radiatum than did those arising from mid and distal levels of CA3.(ABSTRACT TRUNCATED AT 400 WORDS)

Quantitative trait loci on chromosomes 3 and 17 influence phenotypes of the metabolic syndrome

Recent research has emphasized the importance of the metabolic cluster, which includes glucose intolerance, dyslipidemia, and high blood pressure, as a strong predictor of the obesity-related morbidities and premature mortality. Fundamental to this association, commonly referred to as the metabolic syndrome, is the close interaction between abdominal fat patterning, total body adiposity, and insulin resistance. As the initial step in identifying major genetic loci influencing these phenotypes, we performed a genomewide scan by using a 10-centiMorgan map in 2,209 individuals distributed over 507 nuclear Caucasian families. Pedigree-based analysis using a variance components linkage model demonstrated a quantitative trait locus (QTL) on chromosome 3 (3q27) strongly linked to six traits representing these fundamental phenotypes [logarithm of odds (lod) scores ranged from 2.4 to 3.5]. This QTL exhibited possible epistatic interaction with a second QTL on chromosome 17 (17p12) strongly linked to plasma leptin levels (lod = 5.0). Situated at these epistatic QTLs are candidate genes likely to influence two biologic precursor pathways of the metabolic syndrome.

Catalytic mechanism of F1-ATPase

The structure of the core catalytic unit of ATP synthase, alpha 3 beta 3 gamma, has been determined by X-ray crystallography, revealing a roughly symmetrical arrangement of alternating alpha and beta subunits around a central cavity in which helical portions of gamma are found. A low-resolution structural model of F0, based on electron spectroscopic imaging, locates subunit a and the two copies of subunit b outside of a subunit c oligomer. The structures of individual subunits epsilon and c (largely) have been solved by NMR spectroscopy, but the oligomeric structure of c is still unknown. The structures of subunits a and delta remain undefined, that of b has not yet been defined but biochemical evidence indicates a credible model. Subunits gamma, epsilon, b, and delta are at the interface between F1 and F0; gamma epsilon complex forms one element of the stalk, interacting with c at the base and alpha and beta at the top. The locations of b and delta are less clear. Elucidation of the structure F0, of the stalk, and of the entire F1F0 remains a challenging goal.

Primary, syncytium-inducing human immunodeficiency virus type 1 isolates are dual-tropic and most can use either Lestr or CCR5 as coreceptors for virus entry

A panel of primary syncytium-inducing (SI) human immunodeficiency virus type 1 isolates that infected several CD4+ T-cell lines, including MT-2 and C8166, were tested for infection of blood-derived macrophages. Infectivity titers for C8166 cells and macrophages demonstrated that primary SI strains infected macrophages much more efficiently than T-cell line-adapted HIV-1 strains such as LAI and RF. These primary SI strains were therefore dual-tropic. Nine biological clones of two SI strains, prepared by limiting dilution, had macrophage/C8166 infectivity ratios similar to those of their parental viruses, indicating that the dual-tropic phenotype was not due to a mixture of non-SI/macrophage-tropic and SI/T-cell tropic viruses. We tested whether the primary SI strains used either Lestr (fusin) or CCR5 as coreceptors. Infection of cat CCC/CD4 cells transiently expressing Lestr supported infection by T-cell line-adapted strains including LAI, whereas CCC/CD4 cells expressing CCR5 were sensitive to primary non-SI strains as well as to the molecularly cloned strains SF-162 and JR-CSF. Several primary SI strains, as well as the molecularly cloned dual-tropic viruses 89.6 and GUN-1, infected both Lestr+ and CCR5+ CCC/CD4 cells. Thus, these viruses can choose between Lestr and CCR5 for entry into cells. Interestingly, some dual-tropic primary SI strains that infected Lestr+ cells failed to infect CCR5+ cells, suggesting that these viruses may use an alternative coreceptor for infection of macrophages. Alternatively, CCR5 may be processed or presented differently on cat cells so that entry of some primary SI strains but not others is affected.

P-glycoprotein is stably inhibited by vanadate-induced trapping of nucleotide at a single catalytic site

P-glycoprotein (Pgp or multidrug-resistance protein) shows drug-stimulated ATPase activity. The catalytic sites are known to be of low affinity and specificity for nucleotides. From the sequence, two nucleotide sites are predicted per Pgp molecule. Using plasma membranes from a multidrug-resistant Chinese hamster ovary cell line, which are highly enriched in Pgp, we show that vanadate-induced trapping of nucleotide at a single catalytic site produces stably inhibited Pgp, with t 1/2 for reactivation of ATPase activity of 84 min at 37 degrees C and >30 h at 4 degrees C. Reactivation of ATPase correlated with release of trapped nucleotide. Concentrations of MgATP and MgADP required to produce 50% inhibition were 9 and 15 microM, respectively, thus the apparent affinity for nucleotide is greatly increased by vanadate-trapping. The trapped nucleotide species was ADP. Divalent Cation was required, with magnesium, manganese, and cobalt all effective: cobalt yielded a very stable inhibited species, t1/2 at 37 degrees C = 18 h. No photocleavage of Pgp was observed after vanadate trapping with MgATP, nor was UV-induced photolabeling of Pgp by trapped adenine nucleotide observed. Vanadate-trapping with 8-azido-ATP followed by UV irradiation caused permanent inactivation and specific labeling of Pgp. Vanadate-induced inhibition was also shown with pure, reconstituted Pgp, with similar characteristics to those in plasma membranes. Vanadate trapping overcomes technical difficulties posed by lack of high affinity nucleotide-binding site(s) or a covalent enzyme-phosphate catalytic intermediate in Pgp. The finding that vanadate trapping of nucleotide at just one site/Pgp is sufficient to give full inhibition at ATPase activity shows that the two predicted nucleotide sites can not function independently as catalytic sites.

Identification of novel susceptibility loci for inflammatory bowel disease on chromosomes 1p, 3q, and 4q: evidence for epistasis between 1p and IBD1

The idiopathic inflammatory bowel diseases, Crohn's disease (CD) and ulcerative colitis (UC), are chronic, frequently disabling diseases of the intestines. Segregation analyses, twin concordance, and ethnic differences in familial risks have established that CD and UC are complex, non-Mendelian, related genetic disorders. We performed a genome-wide screen using 377 autosomal markers, on 297 CD, UC, or mixed relative pairs from 174 families, 37% Ashkenazim. We observed evidence for linkage at 3q for all families (multipoint logarithm of the odds score (MLod) = 2.29, P = 5.7 x 10(-4)), with greatest significance for non-Ashkenazim Caucasians (MLod = 3.39, P = 3.92 x 10(-5)), and at chromosome 1p (MLod = 2.65, P = 2.4 x 10(-4)) for all families. In a limited subset of mixed families (containing one member with CD and another with UC), evidence for linkage was observed on chromosome 4q (MLod = 2.76, P = 1.9 x 10(-4)), especially among Ashkenazim. There was confirmatory evidence for a CD locus, overlapping IBD1, in the pericentromeric region of chromosome 16 (MLod = 1.69, P = 2.6 x 10(-3)), particularly among Ashkenazim (MLod = 1.51, P = 7.8 x 10(-3)); however, positive MLod scores were observed over a very broad region of chromosome 16. Furthermore, evidence for epistasis between IBD1 and chromosome 1p was observed. Thirteen additional loci demonstrated nominal (MLod > 1.0, P < 0.016) evidence for linkage. This screen provides strong evidence that there are several major susceptibility loci contributing to the genetic risk for CD and UC.

Molecular cloning and analysis of functional envelope genes from human immunodeficiency virus type 1 sequence subtypes A through G. The WHO and NIAID Networks for HIV Isolation and Characterization

Present knowledge of human immunodeficiency virus type 1 (HIV-1) envelope immunobiology has been derived almost exclusively from analyses of subtype B viruses, yet such viruses represent only a minority of strains currently spreading worldwide. To generate a more representative panel of genetically diverse envelope genes, we PCR amplified, cloned, and sequenced complete gp160 coding regions of 35 primary (peripheral blood mononuclear cell-propagated) HIV-1 isolates collected at major epicenters of the current AIDS pandemic. Analysis of their deduced amino acid sequences revealed several important differences from prototypic subtype B strains, including changes in the number and distribution of cysteine residues, substantial length differences in hypervariable regions, and premature truncations in the gp41 domain. Moreover, transiently expressed glycoprotein precursor molecules varied considerably in both size and carbohydrate content. Phylogenetic analyses of full-length env sequences indicated that the panel included members of all major sequence subtypes of HIV-1 group M (clades A to G), as well as an intersubtype recombinant (F/B) from an infected individual in Brazil. In addition, all subtype E and three subtype G viruses initially classified on the basis of partial env sequences were found to cluster in subtype A in the 3' half of their gp41 coding region, suggesting that they are also recombinant. The biological activity of PCR-derived env genes was examined in a single-round virus infectivity assay. This analysis identified 20 clones, including 1 from each subtype (or recombinant), which expressed fully functional envelope glycoproteins. One of these, derived from a patient with rapid CD4 cell decline, contained an amino acid substitution in a highly conserved endocytosis signal (Y721C), as mediated virus entry with very poor efficiency, although they did not contain sequence changes predicted to alter protein function. These results indicate that the env genes of primary HIV-1 isolates collected worldwide can vary considerably in their genetic, phylogenetic, and biological properties. The panel of env constructs described here should prove valuable for future structure-function studies of naturally occurring envelope glycoproteins as well as AIDS vaccine development efforts targeted against a broader spectrum of viruses.

Association between intraepithelial Escherichia coli and colorectal cancer

BACKGROUND & AIMS

Although multiple studies have focused on Helicobacter pylori, little is known about the mucosa-associated flora of the colon. The aim of this study was to detect bacteria directly in colonic mucosa from patients screened for colorectal cancer.

METHODS

Bacteria were quantified with the polymerase chain reaction and identified by comparative sequence analysis in colonoscopic biopsy specimens from 31 asymptomatic and 34 symptomatic controls with normal colonoscopic findings, 29 patients with colonic adenoma, and 31 patients with colorectal carcinoma. In 41 patients, intra- and extracellular location of bacteria was confirmed with the gentamicin protection assay.

RESULTS

No bacteria were detected in biopsy specimens from 97% of asymptomatic and 69% of symptomatic controls. In contrast, bacterial concentrations of 10(3)-10(5) colony-forming units per microliter were detected in biopsy specimens from both malignant and macroscopically normal tissue in 90% and 93% of patients with adenoma and carcinoma, respectively. E. coli and coli-like bacteria were shown to colonize the colonic mucosa in 82% of these patients. The gentamicin protection assay indicated that E. coli was partially intracellular in 87% of patients with adenoma and carcinoma and in none of the controls.

CONCLUSIONS

The colonic mucosa of patients with colorectal carcinoma but not normal colonic mucosa is colonized by intracellular E. coli.

Genetic analysis of adenovirus type 2 III. Temperature sensitivity of processing viral proteins

Using sodium dodecyl sulfate-polyacrylamide slab gel electrophoresis of [35S]methionine-labeled adenovirus type 2-infected KB cell extracts, a total of 23 virus-induced polypeptides was detected. This technique was applied to the analysis of the temperature-sensitive mutant, ts 1, which has previously been shown to be defective in a late function. By means of pulse-chase experiments, ts 1 was shown to be defective in the processing of the precursor polypeptide (Pre VII) to the major core protein VII. Two other putative precursor polypeptides, Va (27K) and Vb (24K), were also not processed. Thus, the ts 1 mutation blocked the appearance of six post-translational clevage products, i. e., polypeptides VI, VII, VIII, X, XI, and XII. All of these polypeptides are virion components. Processing was temperature sensitive in a shift-up experiment, whereas it was normal in a shift-down experiment. The kinetics of the temperature-shift experiments suggested that infectious virus could be recovered if enough time is provided for processing to take place. Processing was not inhibited by cycloheximide. The analysis of purified virus particles and empty shells (TCs) revealed the presence of the precursor and putative precursor polypeptides Pre-VII, Va and Vb, instead of their cleavage products, in both types of particles. Based on these results we propose that the ts 1 gene codes for or regulates an endoprotease which is responsible for the completion of the last step in virus maturation, that is, the conversion of "young virions" into mature infectious virions by a series of maturation cleavages.

Chromosomal assignment of the second locus for autosomal dominant cerebellar ataxia (SCA2) to chromosome 12q23-24.1

The autosomal dominant cerebellar ataxias (ADCA) are a group of neurodegenerative disorders characterized by onset with gait ataxia, dysarthria, dysmetria and dysdiadochokinesia. We have demonstrated previously genetic heterogeneity within these disorders by excluding the disease locus from the documented spinocerebellar ataxia locus (SCA1) on chromosome 6p in a large Cuban founder population. We now report the assignment of a second locus for ADCA (SCA2) to chromosome 12q23-24.1 following linkage analyses carried out for the Cuban pedigrees, with probable flanking markers D12S58 and phospholipase A2. Investigation of linkage to the interval containing SCA2 for seven French ADCA families, previously excluded from linkage to SCA1, provides preliminary data suggesting the existence of a third ADCA locus (SCA3).

Effects of interleukin-12 on the immune response to a multipeptide vaccine for resected metastatic melanoma

PURPOSE

Forty-eight patients with high-risk re-sected stage III or IV melanoma were immunized with two tumor antigen epitope peptides derived from gp100(209-217)(210M) (IMDQVPSFV) and tyrosinase(368-376)(370D) (YMDGTMSQV) emulsified with incomplete Freund's adjuvant (IFA). Patients received peptides/IFA with or without interleukin (IL)-12 30 ng/kg to evaluate the toxicities and immune responses in either arm with time to relapse and survival as secondary end points.

PATIENTS AND METHODS

Immunizations were administered every 2 weeks for 8 weeks, then every 4 weeks for 12 weeks, and then once 8 weeks later. A leukapheresis to obtain peripheral-blood mononuclear cells for immune analyses was done before and after vaccination. Skin testing with peptides and recall reagents was performed before and after vaccinations.

RESULTS

Local pain and granuloma formation, fever, and lethargy of grade 1 or 2 were observed. Transient vaccine-related grade 3-but no grade 4-toxicity was observed. Thirty-four of 40 patients developed a positive skin test response to the gp100 peptide but none to tyrosinase. Immune responses were measured by release of gamma-interferon in an enzyme-linked immunosorbent assay (ELISA) by effector cells in the presence of peptide-pulsed antigen-presenting cells or by an antigen-specific tetramer flow cytometry assay. Thirty-three of 38 patients demonstrated an immune response by ELISA after vaccination, as did 37 of 42 patients by tetramer assay. Twenty-four of 48 patients relapsed with a median follow-up of 20 months, and 10 patients in this high-risk group have died.

CONCLUSION

These data suggest a significant proportion of patients with resected melanoma mount an antigen-specific immune response against a peptide vaccine and indicate that IL-12 may increase the immune response and supporting further development of IL-12 as a vaccine adjuvant.

Safety study of nonoxynol-9 as a vaginal microbicide: evidence of adverse effects

Nonoxynol-9 (N-9) is virucidal in vitro, and is therefore a candidate microbicide for preventing sexual transmission of HIV. However, the activity of N-9 is nonspecific, suggesting that virucidal levels may produce adverse effects including epithelial disruption, inflammation of the genital mucosa, or both. A randomized placebo controlled trial of daily use of 100 mg of N-9 took place for 1 week in 40 female volunteers. Outcome measures included symptoms, colposcopic and histologic changes in the genital tract, and impact on vaginal flora. Genital irritation was reported by 10 of the N-9 and 5 of the placebo group. Colposcopy showed erythema in 9 of the N-9 group and 2 of the placebo group. Histologic inflammation was found in 7 of the N-9 group and 2 of the placebo group. Inflammatory changes were characterized by patchy infiltration of the lamina propria predominantly with CD8+ lymphocytes and macrophages, in the absence of epithelial disruption. A transient reduction in numbers of lactobacilli was observed in 9 of the 15 women using N-9, and 6 of 18 women using placebo. N-9 used for 7 days in a standard spermicidal dose was associated with increased irritation, colposcopic and histologic evidence of inflammation and was more frequently associated with reduction in numbers of lactobacilli during gel use. The clinical significance of the recruitment of cells susceptible to HIV infection to the genital mucosa is unknown but raises concerns about the suitability of N-9 as a microbicide when given in this dose.

Optimization of 4-phenylamino-3-quinolinecarbonitriles as potent inhibitors of Src kinase activity

Subsequent to the discovery of 4-[(2,4-dichlorophenyl)amino]-6,7-dimethoxy-3-quinolinecarbonitrile (1a) as an inhibitor of Src kinase activity (IC(50) = 30 nM), several additional analogues were prepared. Optimization of the C-4 anilino group of 1a led to 1c, which contains a 2,4-dichloro-5-methoxy-substituted aniline. Replacement of the methoxy group at C-7 of 1c with a 3-(morpholin-4-yl)propoxy group provided 2c, resulting in increased inhibition of both Src kinase activity and Src-mediated cell proliferation. Analogues of 2c with other trisubstituted anilines at C-4 were also potent Src inhibitors, and the propoxy group of 2c was preferred over ethoxy, butoxy, or pentoxy. Replacement of the morpholine group of 2c with a 4-methylpiperazine group provided 31a, which had an IC(50) of 1.2 nM in the Src enzymatic assay, an IC(50) of 100 nM for the inhibition of Src-dependent cell proliferation and was selective for Src over non-Src family kinases. Compound 31a, which had higher 1 and 4 h plasma levels than 2c, effectively inhibited tumor growth in xenograft models.

Children in food-insufficient, low-income families: prevalence, health, and nutrition status

OBJECTIVE

To examine characteristics of US children living in food-insufficient households and to compare food and nutrient intakes, physical inactivity, and overweight and underweight status of children in food-insufficient households with those in food-sufficient households.

DESIGN

Cross-sectional, nationally representative sample of children and households from the Continuing Survey of Food Intakes by Individuals, from 1994 to 1996.

PARTICIPANTS

A group of 3790 households, including 5669 children (ages 0-17 years).

MAIN OUTCOME MEASURE(S)

Estimates of food insufficiency for children were based on the reported adequacy of their households, described as "often don't have enough to eat" or "sometimes don't have enough to eat." Nutrient consumption was based on two 24-hour dietary recalls from in-person interviews.

RESULTS

Three percent of all households with children, and 7.5% of low-income families with children experienced food insufficiency. Several demographic and characteristic differences were observed between the food-sufficient and food-insufficient low-income groups. Children of low-income families, either food-sufficient or food-insufficient, had similar macronutrient and micronutrient intake, reported exercise, television watching, and percentage of overweight and underweight. When compared with the higher-income food-sufficient households, children in the low-income food-insufficient households consumed fewer calories (P =.05) and total carbohydrates (P =.004), but had a higher cholesterol intake (P =.02). The low-income food-insufficient group included more overweight children (P =.04), consumed less fruits (P =.04), and spent more time watching television (P =.02).

CONCLUSIONS

While not different from low-income families who do not report food insufficiency, low-income families with food insufficiency had children who differed from high-income families in several nutrition and anthropometric measures. Clinicians should be aware of the possible effects of poverty and lack of access to food on child health and nutrition status. The long-term effects of these are not yet known.

Prophylaxis and management of hamstring muscle injuries in intercollegiate football players

Hamstring muscle strains were responsible for the loss of playing time of a significant number of football players at the University of Nebraska in the early 1970s. After the acquisition of a Cybex II isokinetic dynamometer, the number of injuries was noted to decrease. A retrospective study was performed over the period 1973 to 1982. Players in Group I, from 1973 to 1977, underwent a training program consisting of a supervised winter running program and self-designed year-long stretching, running, and weight lifting. Hamstring injuries were managed with rest, ice, and elevation initially and, by the third day, mild running was instituted. On the average, by the 14th day the athlete had demonstrated adequate speed and agility and was allowed to return to action. Group II consisted of players from the 1978 to 1982 period. These players received supervised winter running programs and staff-designed year-long stretching, running, and weight lifting programs. In addition, all athletes had baseline testing of hamstrings and quadriceps. Deficits were corrected to a desired ratio of 0.60. Injured players in Group II were treated with rest, ice, and elevation initially. High speed isokinetic workouts were begun on the third day with testing on the fifth day. They were allowed to begin jogging when the peak torque of hamstrings equaled 70% of baseline. Players returned to action when peak-torque reached a level of 95% of the baseline score or a hamstrings:quadriceps ratio of 0.55 or greater. Average time out of action was 2 weeks.(ABSTRACT TRUNCATED AT 250 WORDS)

The initiation sites for RNA transcription in Ad2 DNA

Six restriction fragments of Ad2 DNA which contain sites for RNA initiation have been identified by their ability to hybridize nascent labeled RNA less than 1 kb in length. Four RNA initiation sites early in infection are identified in regions where previous work (Flint, 1977) had mapped mRNAs. The major late RNA initiation site is the origin of a giant nuclear transcript extending from approximately 16.3 map units to (or close to) 100 units at the end of the genome. This transcription unit encompasses at least four or five mRNA sites; processing of this long transcript appears necessary to generate the mRNA.

The definition of a large viral transcription unit late in Ad2 infection of HeLa cells: mapping of nascent RNA molecules labeled in isolated nuclei

Nuclei isolated from HeLa cells 15 hr after infection with Ad2 synthesize an RNA transcript approximately 25 KB long, beginning between 0.2 and 0.3 on the physical map and extending to (or close to) the right end of the genome. The majority (60-92%) of the RNA transcribed from fragments between 0.2 and 1.0 is synthesized as part of this large molecule which represents the major product of late Ad2 RNA synthesis. Smaller transcripts are also formed mainly from the left end of the Ad2 genome.

Isolating the spectroscopic signature of a hydration shell with the use of clusters: superoxide tetrahydrate

Cluster spectroscopy, aided by ab initio theory, was used to determine the detailed structure of a complete hydration shell around an anion. Infrared spectra of size-selected O(2)-. (H(2)O)(n) (n = 1 to 4) cluster ions were obtained by photoevaporation of an argon nanomatrix. Four water molecules are required to complete the coordination shell. The simple spectrum of the tetrahydrate reveals a structure in which each water molecule is engaged in a single hydrogen bond to one of the four lobes of the pi* orbital of the superoxide, whereas the water molecules bind together in pairs. This illustrates how water networks deform upon accommodating a solute ion to create a distinct supramolecular species.

Genetic linkage of Werner's syndrome to five markers on chromosome 8

Werner's syndrome (WS) is a rare autosomal recessive disease in which the affected individuals display symptoms of premature ageing. The substantial phenotypic overlap between WS and normal ageing indicates that these two conditions may have pathogenetic mechanisms in common. The WS mutation has pleiotropic effects, and patients and their cells show many differences compared with normals. Despite extensive study of the clinical and biochemical features of this disorder, the primary genetic defect remains unknown. We have undertaken a genetic linkage study in an effort to identify the locus of the primary defect. Here we report close genetic linkage of the WS mutation to a group of markers on chromosome 8.

Evidence that a locus for familial psoriasis maps to chromosome 4q

Psoriasis is an inflammatory skin disease that affects 2% of the population. It is characterised by red, scaly skin patches which are usually found on the scalp, elbows and knees, and may be associated with severe arthropathy. The lesions are caused by abnormal keratinocyte proliferation, and infiltration of inflammatory cells into the dermis and epidermis. The usual age of onset of psoriasis is between 15 and 30 years, although it can present at any age. Psoriasis is recognised to have a large genetic component. Twin studies show the concordance in monozygotic twins to be between 65-70%, compared to between 15-20% in dizygotic twins. Family studies estimate the risk to first degree relatives at between 8-23%. However, there are also several environmental factors, including streptococcal infection and stress, that affect the onset and presentation of the disease. The mode of inheritance of psoriasis is unclear. We conducted a genome-wide scan to search for psoriasis susceptibility loci in a single large multiplex family. Parametric linkage analysis indicated that a susceptibility locus for familial psoriasis was located on chromosome 4q. Investigation of this locus in five further multiplex families using both parametric and non-parametric methods gave significant localisation to chromosome 4q. The maximum total pairwise lod score obtained was 3.03 with the microsatellite marker D4S1535 at theta = 0.08. Non-parametric multipoint analysis with GENEHUNTER- demonstrated significant excess allele sharing, with a P value of 0.0026, at the same locus.

Response to anti-PD1 therapy with nivolumab in metastatic sarcomas

BACKGROUND

Manipulation of immune checkpoints such as CTLA4 or PD-1 with targeted antibodies has recently emerged as an effective anticancer strategy in multiple malignancies. Sarcomas are a heterogeneous group of diseases in need of more effective treatments. Different subtypes of soft tissue and bone sarcomas have been shown to express PD-1 ligand.

METHODS

We retrospectively analyzed a cohort of patients (pts) with relapsed metastatic/unresectable sarcomas, who were treated with nivolumab provided under a patient assistance program from the manufacturer. Pts underwent CT or PET/CT imaging at baseline and after at least four doses of nivolumab; RECIST 1.1 criteria were used for response assessment.

RESULTS

Twenty-eight pts with soft tissue (STS, N = 24) or bone sarcoma (N = 4), received IV nivolumab 3 mg/kg every 2 weeks from July 2015. Median age was 57 (24-78), male:female ratio was 14:14; the median number of nivolumab cycles was eight. Eighteen pts concomitantly received pazopanib at 400-800 mg daily. The most common side effect was grade 1-2 LFT elevations; grade 3-4 toxicity occurred in five patients (colitis, LFT elevations, pneumonitis). Twenty-four pts received at least four cycles. We observed three partial responses: one dedifferentiated chondrosarcoma, one epithelioid sarcoma and one maxillary osteosarcoma (last two patients on pazopanib); nine patients had stable disease including three leiomyosarcomas; 12 patients had progression of disease including 4 leiomyosarcoma. Clinical benefit (response + stability) was observed in 50% of the evaluable patients.

CONCLUSIONS

These data provide a rationale for further exploring the efficacy of nivolumab and other checkpoint inhibitors in soft tissue and bone sarcoma.