Residual DNA quantification in clinical batches of BBG2Na, a recombinant subunit vaccine against human respiratory syncytial virus

BBG2Na, a well-defined recombinant protein produced in Escherichia coli, is a promising human respiratory syncytial virus subunit vaccine candidate. This study describes the quantification of residual DNA in large scale batches used in phase I to III clinical trials. Two different analytical methods were developed and applied on five different final bulks of Drug Substance and their associated in process control samples, namely a chemiluminescent hybridisation assay and the total DNA Threshold System assay. These two complementary methods demonstrated the clearance of residual DNA during the downstream purification process. The amount of residual DNA found in the final bulks was below 20 pg of DNA per 300 microg BBG2Na, the highest tested clinical dose of antigen. This is very low level of residual DNA for a recombinant subunit vaccine produced in a bacteria and contribute to make for BBG2Na a well-characterised biopharmaceutical. This study also provides data concerning the validation of the hybridisation dot blot assay and the total DNA Threshold(trade mark)assay.

Synthesis and characterization of respiratory syncytial virus protein G related peptides containing two disulphide bridges

Respiratory Syncytial Virus (RSV) is the most important cause of bronchiolitis and viral pneumoniae in infants and young children. Approximately 100,000 children are hospitalized in the USA each year as a result of RSV infections. During the research and development of subunit human RSV vaccines, we have produced numerous synthetic peptides and recombinant proteins containing the four cysteines of the highly conserved central region of the G attachment protein. For several of these disulphide bridges containing peptides, all possible oxidizing isomers were synthesized using various oxidising conditions, resulting in different ratios of isomers. Each isolated isomer was fully characterized by RP-HPLC, FZCE and ES-MS after purification by preparative RP-HPLC. The different cysteine pairings were unambiguously established after enzymatic digestion, LC-MS analysis and peptide microsequencing. These synthetic and analytical methods were developed for the characterization of recombinant fusion protein BBG2Na which is currently investigated in clinical phase II and seems to be as a very promising vaccine candidate, and for peptides which were synthesized to be evaluated as conjugate vaccines or as immunochemical tools, after covalent coupling to carrier proteins. Furthermore, these studies allowed us to determine which of the different possible isomers was the most stable and probably the preferred form in native conditions. Finally, the different oxidising and analysis conditions, should be useful for disulphide pairing studies of other peptides and proteins having the same "xCxxCxxxxxCxxxCx" framework, such as G proteins of non-human RSV strains, developed for example as veterinary vaccine candidates.

Development of a quantitative assay for residual host cell proteins in a recombinant subunit vaccine against human respiratory syncytial virus

We have developed and validated a process-specific immunoligand assay based on the Threshold system for the quantification of residual host cell proteins (HCPs) in a recombinant subunit vaccine candidate against the human respiratory syncytial virus (hRSV). The industrial process of this vaccine produced in Escherichia coli, involved five chromatography steps for the production of clinical-grade batches. The clearance of non-product-related protein throughout the purification process was documented by the evaluation of the HCP content in the chromatographic fractions at each step of the downstream processing. The assay had a detection limit of 0.5 ng/ml of HCP equivalent to 10 parts per million (ppm). The quantification limit was 1.3 ng/ml of HCP, giving a sensitivity range of the assay of 10 to 30 ppm. To our knowledge, this is the first sensitive HCP assay reported for a vaccine.

Bursting activity in leech Retzius neurons induced by low external chloride

We have investigated the bursting activity of Retzius neurons in the central nervous system of the leech Hirudo medicinalis as induced in Cl(-)-free saline by measuring membrane potential, membrane current and the intracellular calcium concentration ([Ca2+]i), using fura-2 or Oregon-Green488-Bapta-1. The Retzius neurons changed their low tonic firing to rhythmical bursting activity when the extracellular Cl- concentration ([Cl-]o) was lowered to 1 mM or less. In Cl(-)-free saline (Cl- exchanged by gluconate), bursting was accompanied by a rise in intracellular Ca2+ in both cell body and axon, which oscillated in synchrony with the bursts. The Ca2+ transients depended on the amplitude and duration of the depolarization underlying the burst, and were presumably due to Ca2+ influx through voltage-dependent Ca2+ channels. In Ca(2+)-free, EGTA-buffered saline or in the presence of Ca2+ channel blockers verapamil (1 mM) or diltiazem (500 microM) the depolarizations underlying the bursts in Cl(-)-free saline were enhanced in amplitude and duration. Bursting was not affected by depleting the intracellular Ca2+ stores with cyclopiazonic acid. The depolarization in Cl(-)- and Ca(2+)-free saline did not evoke intracellular Ca2+ changes. The burst-underlying membrane depolarization induced by Cl- removal was found to be due to a Na(+)-dependent persistent inward current and could be inhibited by saxitoxin (25-50 microM). The results suggest that a persistent Na+ current is generated in Cl(-)-free saline and induces the depolarization underlying rhythmic activity, and that presumably Ca(2+)-induced K+ currents modulate the bursting behaviour.

Identification and characterisation of multiple linear B cell protectopes in the respiratory syncytial virus G protein

Respiratory syncytial virus (RSV) is an important respiratory pathogen in man, against which no vaccine is available. However, recent evidence suggests that antibodies to the RSV F and G proteins may play an important role in disease prevention. We previously demonstrated that BBG2Na, a subunit vaccine candidate including residues 130-230 of the Long strain G protein, protects rodents against RSV challenge. Using a panel of monoclonal antibodies (MAb) and synthetic peptides, five linear B cell epitopes were identified that mapped to residues 152-163, 165-172, 171-187 (two over-lapping epitopes) and 196-204. Antibody passive transfer and peptide immunisation studies revealed that all were protective. Pepscan analyses of anti-RSV-A and BBG2Na murine polyclonal sera suggested stronger immunogenicity of some protective epitopes (protectopes) in the context of BBG2Na compared with live virus. However, all the identified murine B cell protectopes were conserved in RSV seropositive humans. Should these protectopes correspond with protection in humans, BBG2Na may constitute a very interesting vaccine candidate against RSV.

Reducing emergency visits in older adults with chronic illness. A randomized, controlled trial of group visits

CONTEXT

Emergency department utilization by chronically ill older adults may be an important sentinel event signifying a breakdown in care coordination. A primary care group visit (i.e., several patients meeting together with the provider at the same time) may reduce fragmentation of care and subsequent emergency department utilization.

OBJECTIVE

To determine whether primary care group visits reduce emergency department utilization in chronically ill older adults.

DESIGN

Randomized trial conducted over a 2-year period.

SETTING

Group-model HMO in Denver, Colorado.

PATIENTS

295 older adults (> or = 60 years of age) with frequent utilization of outpatient services and one or more chronic illnesses.

INTERVENTION

Monthly group visits (generally 8 to 12 patients) with a primary care physician, nurse, and pharmacist held in 19 physician practices. Visits emphasized self-management of chronic illness, peer support, and regular contact with the primary care team.

MEASURES

Emergency department visits, hospitalizations, and primary care visits.

RESULTS

On average, patients in the intervention group attended 10.6 group visits during the 2-year study period. These patients averaged fewer emergency department visits (0.65 vs. 1.08 visits; P = 0.005) and were less likely to have any emergency department visits (34.9% vs. 52.4%; P = 0.003) than controls. These differences remained statistically significant after controlling for demographic factors, comorbid conditions, functional status, and prior utilization. Adjusted mean difference in visits was -0.42 visits (95% CI, -0.13 to -0.72), and adjusted RR for any emergency department visit was 0.64 (CI, 0.44 to 0.86).

CONCLUSION

Monthly group visits reduce emergency department utilization for chronically ill older adults.

A candidate prostate cancer susceptibility gene at chromosome 17p

It is difficult to identify genes that predispose to prostate cancer due to late age at diagnosis, presence of phenocopies within high-risk pedigrees and genetic complexity. A genome-wide scan of large, high-risk pedigrees from Utah has provided evidence for linkage to a locus on chromosome 17p. We carried out positional cloning and mutation screening within the refined interval, identifying a gene, ELAC2, harboring mutations (including a frameshift and a nonconservative missense change) that segregate with prostate cancer in two pedigrees. In addition, two common missense variants in the gene are associated with the occurrence of prostate cancer. ELAC2 is a member of an uncharacterized gene family predicted to encode a metal-dependent hydrolase domain that is conserved among eukaryotes, archaebacteria and eubacteria. The gene product bears amino acid sequence similarity to two better understood protein families, namely the PSO2 (SNM1) DNA interstrand crosslink repair proteins and the 73-kD subunit of mRNA 3' end cleavage and polyadenylation specificity factor (CPSF73).

Stress analysis of the aortic valve with and without the sinuses of valsalva

BACKGROUND AND AIM OF THE STUDY

In some patients with dilated aortic root, attempts have been made to replace the aorta and preserve the anatomically normal leaflets. The tubular Dacron graft used in the valve-sparing procedure does not have the sinuses of Valsalva, and therefore might adversely affect the valve. The effect of the presence or absence of the sinuses was investigated on stresses in the leaflets.

METHODS

Finite element models of the tubular aortic root and the root with the sinuses were constructed. The model dimensions were: aorta radius 13 mm; valve height 18 mm; leaflet thickness 0.5 mm; aorta and sinus wall thickness 1.3 mm. In the root with the sinuses, each leaflet-sinus unit formed a cylindrical geometry. The model was loaded with an internal pressure of 80 mmHg (0.01 N/mm2) and the stress determined.

RESULTS

The stress in the leaflet belly was 0.26 N/mm2, and not affected by the geometry and stiffness of the root. In the tubular root there was a stress concentration along the leaflet attachment, and the stress reached 0.65 N/mm2; in contrast, in the sinus root there was no stress concentration and maximum stress was only 0.3 N/mm2. Under pressure, the leaflet-sinus assembly expanded in a uniform manner, whereas in a tubular root large deformations occurred along the leaflet attachment.

CONCLUSION

The sinuses of Valsalva play a very important role in minimizing stress in the leaflets; thus, use of the sinus graft is expected to enhance the longevity of the spared valve.

Alkaline liquid chromatography/electrospray ionization skimmer collision-induced dissociation mass spectrometry for phosphopeptide screening

A rapid on-line method for the identification of phosphorylated peptides in enzymatic protein digests by specific marker ion signals is described. In our study we investigated the use of alkaline conditions together with a previously described method for selective and sensitive detection of phosphopeptide ions combining high-performance capillary liquid chromatography (LC) and electrospray ionization mass spectrometry (ESI-MS). Phosphorylation-specific marker ions (m/z 79, PO(3)(-), and m/z 97, H(2)PO(4)(-)) were generated by skimmer collision-induced dissociation (sCID) in the negative-ion mode. The method was evaluated and validated for mono-phosphorylated synthetic peptides using different alkaline pH values and CID offsets. Alkaline conditions (pH 10.5) enhance the generation of phosphopeptide-specific fragment ions from serine- and tyrosine-phosphorylated peptides, and enable the use of m/z 79 (PO(3)(-)) and m/z 97 (H(2)PO(4)(-)) as phosphorylation-specific marker traces. Note that HPLC separation in trifluoroacetic acid containing solvents impairs the use of m/z 97 (C(2)F(3)O(-) fragment ion at m/z 97) as a phosphorylation-specific marker. The optimized method was applied for the detection of phosphorylated peptides in a tryptic beta-casein digest. The expected mono- and tetra-phosphorylated peptides were detected and rapidly identified by (mu)LC/ESI-sCID-MS and (mu)LC/ESI-MS analysis.

Spanning or looping? The order and conformation of bipolar phospholipids in lipid membranes using 2H NMR spectroscopy

Solid-state 2H NMR spectroscopy was used to study and characterize the conformation and order of bolaform lipid membranes. A series of 2H-labeled bolaform phosphatidylcholines has been synthesized and their properties compared to a [D4]dimyristoylphosphatidylcholine (DMPC) and a [D8]-32 macrocyclic phosphatidylcholine. 31P NMR measurements establish that the aqueous dispersions of these lipids adopt lamellar phases. Computational dePakeing was used to extract the spectrum of the oriented system from spectra consisting of a superposition of randomly oriented domains in an unoriented sample. A large (> 90 %) and constant value for the normalized segmental order parameter (Smol) was observed for all positions along the diacyl chain of the bolaform lipids and only a small population (< 10%) of a less ordered conformer was observed. The less ordered conformer is assigned to the looping conformation on the basis of comparison with the deuterated macrocyclic phospholipid which has an enforced loop in its diacyl chain. The predominant population(> 90%) of the bolaform lipids is assigned to a highly ordered, spanning conformer.

Priming by microbial antigens from the intestinal flora determines the ability of CD4+ T cells to rapidly secrete IL-4 in BALB/c mice infected with Leishmania major

Infection of BALB/c mice with Leishmania major results in the rapid accumulation of IL-4 transcripts within CD4(+) T cells that react to the parasite Leishmania homologue of mammalian RACK1 (LACK) Ag. Because memory/effector cells secrete IL-4 more rapidly than naive cells, we sought to analyze the phenotype of these lymphocytes before infection. Indeed, a fraction of LACK-specific CD4(+) T cells expressed a typical CD62 ligand(low)CD44(high)CD45RB(low) phenotype in uninfected mice. LACK-specific T cells were primed in gut-associated lymphoid tissues by cross-reactive microbial Ags as demonstrated by their reactivity with bacterial extracts and by the ability of APCs from the mesenteric LN of BALB/c mice to induce their proliferation. Also, mice in which the digestive tract has been decontaminated exhibited a reduced proportion of LACK-specific T cells expressing a memory/effector phenotype and did not exhibit the early accumulation of IL-4 transcripts induced by L. major. Thus, LACK-specific T cells represent a subset of CD4(+) T cells which have acquired the ability to rapidly secrete IL-4 as the result of their priming by cross-reactive microbial Ags. Tracking the fate of these cells may provide information about the regulation of cell-mediated immune responses to gut Ags in physiological and pathological situations.

Spinal cord injury without radiographic abnormalities in children and adolescents: case report of a severe cervical spine lesion and review of literature

The biomechanics of the child's and juvenile's spine is responsible for the commonly encountered closed spinal trauma with significant neurological injury but without bony or ligament injury (particularly of the cervical spine). The ligamentous laxity and hypermobility of the young bony cervical and thoracic spine predispose to spinal cord injury without radiographic abnormalities. We report a 16-year-old girl with typical features of this type of injury after a "flic-flac" sports injury. We conclude that children and adolescents who have neurological deficits without positive radiographic findings require appropriate diagnostic screening, monitoring, and often a prolonged therapy. The sometimes changing neurological deficits should never be ignored or dismissed as psychogenic affection.

Local permutations in the glomerular array of the mouse olfactory bulb

Olfactory sensory neurons expressing a given odorant receptor gene project their axons with great precision to a few specific glomeruli in the olfactory bulb. It is not clear to which extent the positions of these glomeruli are fixed. We sought to evaluate the constancy of the glomerular array in the mouse by determining the relative positions of glomeruli for various odorant receptors, using a method that affords single-axon resolution, and in a large number of bulbs. We used a genetic strategy to visualize neuronal populations that express one of three members of the mOR37 subfamily. We generated by gene targeting five strains of mice in which expression of a given mOR37 gene is linked to expression of an axonal maker, which is either taulacZ or tauGFP. The patterns of marker expression faithfully mimic those of the cognate receptors. Axons of neurons expressing a given mOR37 gene converge onto one or two glomeruli per bulb. Each mOR37 gene has its own glomeruli, and the mOR37 glomeruli are grouped within a restricted domain of the bulb. Serial sectioning of 214 bulbs reveals that the relative positions of the three types of glomeruli are not fixed but display local permutations. Importantly, this is also the case among the two bulbs from one individual, ruling out the genetic manipulation itself and differences in genetic background or olfactory experience as causes for the observed variability. These local permutations may reflect the developmental history of the glomeruli and are relevant for the construction of spatial odor maps.

Simultaneous, quantitative analysis of UDP-N-acetylglucosamine, UDP-N-acetylgalactosamine, UDP-glucose and UDP-galactose in human peripheral blood cells, muscle biopsies and cultured mesangial cells by capillary zone electrophoresis

The aim of this study was to develop and evaluate a capillary zone electrophoretic (CE) procedure for the accurate quantification of the UDP-hexosamines as well as for the corresponding UDP-hexoses in samples from various biological origins. Testing different buffer conditions, voltages, capillary dimensions and temperatures, optimal results were achieved with a 90 mM borate buffer, pH 9.0, at 18 degrees C and 15.5 kV in an uncoated fused-silica capillary of 50 cm x 50 microm and a detection wavelength of lambda = 262 nm. The total procedure, i.e., including variations of the sample preparation, showed coefficients of variation for the peak areas between 4. 1% and 10.4% in mesangial cells (n = 7) and between 7.8 and 10.3% (n = 6) in leukocytes for the components of interest. To improve precision, an internal standard was used for calibration. The limit of detection for all compounds is an absolute amount of 180 fmol, sufficient for the precise analysis of UDP-sugars in a limited amount of biological samples, such as human leukocytes (obtained from a 10 mL blood sample), muscle biopsies (< or = 100 mg), and mesangial kidney cells (ca. 2.5 x 10(5) cells). This reproducible, quantitative analysis of all four UDP-sugars from various biomedically relevant origins by CZE is a definite improvement over the generally used high performance liquid chromatography (HPLC) procedures. The CZE method allows the study of the flux through the hexosamine pathway in diabetes mellitus and other diseases in a simple, quantitative and accurate way.

Psychiatric patients at greatest risk and in greatest need. Impact of the Supervision Register Policy

BACKGROUND

Mental health provider trusts in England were required in 1994 to establish local Supervision Registers of patients at risk.

AIMS

To identify the factors associated with registration, and obtain clinicians' views on its effectiveness.

METHOD

At a random sample of 14 trusts data were collected from case notes, key workers and responsible medical officers.

RESULTS

A sample of 133 registered patients were more disabled and had more extensive histories of violence and self-harm than 126 comparison patients on the upper tier of the Care Programme Approach (CPA). Those registered were a heterogeneous group. For some there was little evidence of risk. In most cases clinicians did not believe registration had improved care.

CONCLUSIONS

The Supervision Register policy has not resulted in the identification of a well-defined group. Its effectiveness is limited by the lack of operationalized measures of risk.

Practical mental health assessment in primary care. Validity and utility of the Quick PsychoDiagnostics Panel

BACKGROUND

Many case-finding instruments are available to help primary care physicians (PCPs) diagnose depression, but they are not widely used. Physicians often consider these instruments too time consuming or feel they do not provide sufficient diagnostic information. Our study examined the validity and utility of the Quick PsychoDiagnostics (QPD) Panel, an automated mental health test designed to meet the special needs of PCPs. The test screens for 9 common psychiatric disorders and requires no physician time to administer or score.

METHODS

We evaluated criterion validity relative to the Structured Clinical Interview for DSM-IV (SCID), and evaluated convergent validity by correlating QPD Panel scores with established mental health measures. Sensitivity to change was examined by readministering the test to patients pretreatment and posttreatment. Utility was evaluated through physician and patient satisfaction surveys.

RESULTS

For major depression, sensitivity and specificity were 81% and 96%, respectively. For other disorders, sensitivities ranged from 69% to 98%, and specificities ranged from 90% to 97%. The depression severity score correlated highly with the Beck, Hamilton, Zung, and CES-D depression scales, and the anxiety score correlated highly with the Spielberger State-Trait Anxiety Inventory and the anxiety subscale of the Symptom Checklist 90 (Ps <.001). The test was sensitive to change. All PCPs agreed or strongly agreed that the QPD Panel "is convenient and easy to use," "can be used immediately by any physician," and "helps provide better patient care." Patients also rated the test favorably.

CONCLUSIONS

The QPD Panel is a valid mental health assessment tool that can diagnose a range of common psychiatric disorders and is practical for routine use in primary care.

Sequence analyses of the olfactory receptor gene cluster mOR37 on mouse chromosome 4

The olfactory receptor multigene family is organized in clusters spread throughout the genome. In the present study, we have sequenced two subregions of the mOR37 gene cluster on mouse chromosome 4. The resulting 100 kb of sequence revealed seven odorant receptor coding regions and one gene fragment. Sequence analyses reveal that the mOR37 gene cluster may represent a rather ancient cluster. The mOR37 genes exhibit a complex intron/exon structure, and some appear to be differentially spliced. All genes in the cluster share conserved sequence motifs 5' of their putative initial exons, which represent potential binding sites for transcription factors. The clustered organization and conserved sequence motifs suggest common expression control mechanisms for these genes.

Serine residues 1177/78/82 of the insulin receptor are required for substrate phosphorylation but not autophosphorylation

Serine residues of the human insulin receptor (HIR) may be phosphorylated and negatively regulate the insulin signal. We studied the impact of 16 serine residues in HIR by mutation to alanine and co-overexpression in human embryonic kidney (HEK) 293 cells together with the docking proteins insulin receptor substrate (IRS)-1, IRS-2, or (SHC) Src homologous and collagen-like. As a control, IRS-1 was also cotransfected with an HIR with a juxtamembrane deletion (HIR delta JM) and therefore not containing the domain required for interaction with IRS-1. Coexpression of HIR with IRS-1, IRS-2, and SHC strongly enhanced tyrosine phosphorylation of these proteins. A similar increase in tyrosine phosphorylation was observed in cells overexpressing IRS-1, IRS-2, or SHC together with all HIR mutants except HIR delta JM and a mutant carrying exchanges of serines 1177, 1178, and 1182 to alanine (HIR1177/78/82), although this mutant showed normal autophosphorylation. Analysis of total cell lysates with anti-phosphotyrosine antibodies showed that in addition to the overexpressed substrates, other cellular proteins displayed reduced levels of tyrosine phosphorylation in these cells. To study consequences for phosphatidylinositol 3-kinase (PI 3-kinase) activation, we established stable NIH3T3 fibroblast cell lines overexpressing wild-type HIR, HIR1177/78/82, and other HIR mutants as the control. Again, HIR1177/78/82 showed normal autophosphorylation but showed a clear decrease in tyrosine phosphorylation of endogenous IRS-1 and activation of PI 3-kinase. This decrease in kinase activity also occurred in an in vitro kinase assay towards recombinant IRS-1. Finally, we performed a separation of the phosphopeptides by high-performance liquid chromatography and could not detect any differences in the profiles of HIR and HIR1177/78/82. In conclusion, we have defined a region in HIR that is important for substrate phosphorylation but not autophosphorylation. Therefore, this mutant may provide new insights into the mechanism of kinase activation and substrate phosphorylation.

Influence of live respiratory syncytial virus priming on the immune response generated by a recombinant vaccine candidate, BBG2Na

Respiratory syncytial virus is one of the major respiratory pathogens for infants and immunocompromized children. With the exception of young children, all the population has encountered RSV and is seropositive. Recent reports have demonstrated however that the virus also affects the elderly and represents a major cause of illness associated with an excess of morbidity and mortality. We have generated a recombinant RSV vaccine, BBG2Na, which is highly protective in rodents against RSV infection. The aim of this study was to evaluate the ability of the vaccine to increase anti-RSV protection in RSV-primed mice and to characterize the induced immune responses. Immunization with BBG2Na increased the anti-RSV-A serum antibody titers of RSV-primed mice with induction of both IgG1 and IgG2a antibodies attesting for a mixed Th response. Moreover, the level of the induced anti-G2Na antibodies was greater in seropositive mice. Finally, sera from RSV-primed mice displayed a higher protective efficacy after transfer into naive mice following subsequent immunization with BBG2Na than sera of mice immunized with RSV-A only. Our results demonstrate that BBG2Na is immunogenic and increases the protective efficacy of serum antibodies in RSV-primed mice; they support the possibility of performing clinical trials in the seropositive human population.

Influence of administration dose and route on the immunogenicity and protective efficacy of BBG2Na, a recombinant respiratory syncytial virus subunit vaccine candidate

The immunogenicity and protective efficacy of BBG2Na, a novel recombinant respiratory syncytial virus subunit vaccine candidate, was assessed in BALB/c mice under various conditions of dose, administration route and number of immunisations. A single intra-peritoneal (i.p.) dose of 2 microg, or two doses of 0.2 microg, were sufficient to induce elevated RSV-A serum antibodies and sterilising lung protective immunity. Serum antibody titres were significantly boosted following second immunisations, but not a third. Of three routes of immunisation, i.p. induced the highest RSV-A antibody titres, followed in efficacy by the intra-muscular (i. m.) and subcutaneous (s.c.) routes. Nonetheless, all three routes induced comparable and sterilising lung protection. In contrast, upper respiratory tract protection was observed only after i.p. vaccination, although significant viral titre reductions were evident following i.m. or s.c. immunisations. Interestingly, Pepscan analyses indicated that antibody epitope usage was highest in i.p. and lowest in i.m. immunised mice, respectively. Nonetheless, all routes resulted in antibody responses to known lung protective epitopes (protectopes). Thus, the prevention of serious lower respiratory tract disease, the principle goal of a RSV vaccine, but not URT infection, is dose dependent but unlikely to be influenced by the route of BBG2Na administration.

The DNA sequence of human chromosome 21

Chromosome 21 is the smallest human autosome. An extra copy of chromosome 21 causes Down syndrome, the most frequent genetic cause of significant mental retardation, which affects up to 1 in 700 live births. Several anonymous loci for monogenic disorders and predispositions for common complex disorders have also been mapped to this chromosome, and loss of heterozygosity has been observed in regions associated with solid tumours. Here we report the sequence and gene catalogue of the long arm of chromosome 21. We have sequenced 33,546,361 base pairs (bp) of DNA with very high accuracy, the largest contig being 25,491,867 bp. Only three small clone gaps and seven sequencing gaps remain, comprising about 100 kilobases. Thus, we achieved 99.7% coverage of 21q. We also sequenced 281,116 bp from the short arm. The structural features identified include duplications that are probably involved in chromosomal abnormalities and repeat structures in the telomeric and pericentromeric regions. Analysis of the chromosome revealed 127 known genes, 98 predicted genes and 59 pseudogenes.

Factors that contribute to positive perceived health in an older population

This study explored the extent to which factors commonly associated with negative outcomes of aging also predicted positive perceived health in a group of community-dwelling older people. Questionnaires originally administered during a randomized trial of HMO's outpatient group visit program supplied data from approximately 700 participants. Stepwise modeling identified significant factors within categories of predictors of perceived health. Hierarchical multiple linear regression then modeled the incremental importance of theoretically-derived categories of factors. Many but not all of the factors previously associated with negative outcomes of aging also predicted positive perceived health, accounting for 38% of the variation. The most important predictors were fewer chronic conditions and no worsening of those conditions, mobility and better physical performance status, and the absence of depression. Gender, limitations in daily living activities, dementia, and utilization of services had little effect. The categories of f factors associated with positive perceived health had cumulative, interdependent effects.

CD4(+) T-cell-mediated antiviral protection of the upper respiratory tract in BALB/c mice following parenteral immunization with a recombinant respiratory syncytial virus G protein fragment

We analyzed the protective mechanisms induced against respiratory syncytial virus subgroup A (RSV-A) infection in the lower and upper respiratory tracts (LRT and URT) of BALB/c mice after intraperitoneal immunization with a recombinant fusion protein incorporating residues 130 to 230 of RSV-A G protein (BBG2Na). Mother-to-offspring antibody (Ab) transfer and adoptive transfer of BBG2Na-primed B cells into SCID mice demonstrated that Abs are important for LRT protection but have no effect on URT infection. In contrast, RSV-A clearance in the URT was achieved in a dose-dependent fashion after adoptive transfer of BBG2Na-primed T cells, while it was abolished in BBG2Na-immunized mice upon in vivo depletion of CD4(+), but not CD8(+), T cells. Furthermore, the conserved RSV-A G protein cysteines and residues 193 and 194, overlapping the recently identified T helper cell epitope on the G protein (P. W. Tebbey et al., J. Exp. Med. 188:1967-1972, 1998), were found to be essential for URT but not LRT protection. Taken together, these results demonstrate for the first time that CD4(+) T cells induced upon parenteral immunization with an RSV G protein fragment play a critical role in URT protection of normal mice against RSV infection.