Using timeliness metrics for household contact tracing and TB preventive therapy in the private sector, India

BACKGROUND

Although screening of household contacts (HHCs) of TB patients and provision of TB preventive therapy (TPT) is a key intervention to end the TB epidemic, their implementation globally is dismal. We assessed whether introducing a '7-1-7' timeliness metric was workable for implementing HHC screening among index patients with pulmonary TB diagnosed by private providers in Chennai, India, between November 2022 and March 2023.

METHODS

This was an explanatory mixed-methods study (quantitative-cohort and qualitative-descriptive).

RESULTS

There were 263 index patients with 556 HHCs. In 90% of index patients, HHCs were line-listed within 7 days of anti-TB treatment initiation. Screening outcomes were ascertained in 48% of HHCs within 1 day of line-listing. Start of anti-TB treatment, TPT or a decision to receive neither was achieved in 57% of HHC within 7 days of screening. Overall, 24% of screened HHCs in the '7-1-7' period started TPT compared with 16% in a historical control (P < 0.01). Barriers to achieving '7-1-7' included HHC reluctance for evaluation or TPT, refusal of private providers to prescribe TPT and reliance on facility-based screening of HHCs instead of home visits by health workers for screening.

CONCLUSIONS

Introduction of a timeliness metric is a workable intervention that adds structure to HHC screening and timely management..

The NK cell receptor NKp46 recognizes ecto-calreticulin on ER-stressed cells

Natural killer (NK) cell kill infected, transformed and stressed cells when an activating NK cell receptor is triggered1. Most NK cells and some innate lymphoid cells express the activating receptor NKp46, encoded by NCR1, the most evolutionarily ancient NK cell receptor2,3. Blockage of NKp46 inhibits NK killing of many cancer targets4. Although a few infectious NKp46 ligands have been identified, the endogenous NKp46 cell surface ligand is unknown. Here we show that NKp46 recognizes externalized calreticulin (ecto-CRT), which translocates from the endoplasmic reticulum (ER) to the cell membrane during ER stress. ER stress and ecto-CRT are hallmarks of chemotherapy-induced immunogenic cell death5,6, flavivirus infection and senescence. NKp46 recognition of the P domain of ecto-CRT triggers NK cell signalling and NKp46 caps with ecto-CRT in NK immune synapses. NKp46-mediated killing is inhibited by knockout or knockdown of CALR, the gene encoding CRT, or CRT antibodies, and is enhanced by ectopic expression of glycosylphosphatidylinositol-anchored CRT. NCR1)-deficient human (and Nrc1-deficient mouse) NK cells are impaired in the killing of ZIKV-infected, ER-stressed and senescent cells and ecto-CRT-expressing cancer cells. Importantly, NKp46 recognition of ecto-CRT controls mouse B16 melanoma and RAS-driven lung cancers and enhances tumour-infiltrating NK cell degranulation and cytokine secretion. Thus, NKp46 recognition of ecto-CRT as a danger-associated molecular pattern eliminates ER-stressed cells.

Nonspherical ultrasound microbubbles

Surface tension provides microbubbles (MB) with a perfect spherical shape. Here, we demonstrate that MB can be engineered to be nonspherical, endowing them with unique features for biomedical applications. Anisotropic MB were generated via one-dimensionally stretching spherical poly(butyl cyanoacrylate) MB above their glass transition temperature. Compared to their spherical counterparts, nonspherical polymeric MB displayed superior performance in multiple ways, including i) increased margination behavior in blood vessel-like flow chambers, ii) reduced macrophage uptake in vitro, iii) prolonged circulation time in vivo, and iv) enhanced blood-brain barrier (BBB) permeation in vivo upon combination with transcranial focused ultrasound (FUS). Our studies identify shape as a design parameter in the MB landscape, and they provide a rational and robust framework for further exploring the application of anisotropic MB for ultrasound-enhanced drug delivery and imaging applications.

Raman spectroscopy reveals high phloem sugar content in leaves of canopy red oak trees

A robust understanding of phloem functioning in tall trees evades us because current methods for collecting phloem sap do not lend themselves to measuring actively photosynthesizing canopy leaves. We show that Raman spectroscopy can be used as a quantitative tool to assess sucrose concentration in leaf samples. Specifically, we found that Raman spectroscopy can predict physiologically relevant sucrose concentrations (adjusted R² of 0.9) in frozen leaf extract spiked with sucrose. We then apply this method to estimate sieve element sucrose concentration in rapidly frozen petioles of canopy red oak (Quercus rubra) trees and found that sucrose concentrations are > 1100 mM at midday and midnight. This concentration is predicted to generate a sieve element turgor pressure high enough to generate bulk flow through the phloem, but is potentially too high to allow for sucrose diffusion from photosynthetic cells. Our findings support the Münch hypothesis for phloem transport once the carbon is in the phloem and challenge the passive-loading hypothesis for carbon movement into the phloem for red oak. This study provides the first ˜in-situ (frozen in the functioning state) source sieve element sucrose concentration characterization in any plant, opening a new avenue for investigation of phloem functioning.

Development and Implementation of Computerized Clinical Guidelines: Barriers and Solutions

Next, the article discusses the need to incorporate the use of surveys, questionnaires, or rating instruments for the collection of end-user feedback during and after the implementation process. A description of the types of rating instruments that will facilitate the assessment of user satisfaction is provided. Initial results from physician feedback during the implementation of our prototype are discussed. Research indicates that computerized decision support systems (CDSSs) can improve clinical performance and patient outcomes, and yet CDSSs are not in widespread use. Physician guidelines, in general, face barriers in implementation. Guidelines in a computerized format can overcome some of the barriers to conventional text-form guidelines; however, computerized programs have novel aspects that have to be considered, aspects such as technical problems/support and user interface issues that can act as barriers. Though the literature points out that human, organizational, and technical issues can act as barriers in the implementation of CDSSs, studies clearly indicate that there are methods that can overcome these barriers and improve CDSS acceptance and use. These methods come from lessons learned from a variety of CDSS implementation ventures. Notably, most of the methods that improve acceptance and use of a CDSS require feedback and involvement of end-users. Measuring and addressing physician or user attitudes toward the computerized support system has been shown to be important in the successful implementation of a CDSS. This article discusses: 1) the barriers of implementation of guidelines in general and of CDSSs; 2) the importance of the physician’s role in development, implementation, and adherence; 3) methods that can improve CDSS acceptance and use; and 4) the types of tools needed to obtain end-user feedback.

The Coupled Straintronic-Photothermic Effect

We describe the coupled straintronic-photothermic effect where coupling between bandgap of the 2D layered semiconductor under localized strains, optical absorption and the photo-thermal effect results in a large chromatic mechanical response in TMD-nanocomposites. Under the irradiation of visible light (405 nm to 808 nm), such locally strained atomic thin films based on 2H-MoS2 embedded in an elastomer such as poly (dimethyl) siloxane matrix exhibited a large amplitude of photo-thermal actuation compared to their unstrained counterparts. Moreover, the locally strain engineered nanocomposites showed tunable mechanical response giving rise to higher mechanical stress at lower photon energies. Scanning photoluminescence spectroscopy revealed a change in bandgap of 30 meV between regions encompassing highly strained compared to the unstrained few layers. For 1.6% change in the bandgap, the macroscopic photo-thermal response increased by a factor of two. Millimeter scale bending actuators based on the locally strained 2H-MoS2 resulted in significantly enhanced photo-thermal actuation displacements compared to their unstrained counterparts at lower photon energies and operated up to 30 Hz. Almost 1 mN photo-activated force was obtained at 50 mW and provided long-term stability. This study demonstrates a new mechanism in TMD-nanocomposites that would be useful for developing broad range of transducers.

Molecular orientation of asphaltenes and PAH model compounds in Langmuir-Blodgett films using sum frequency generation spectroscopy

Asphaltenes are an important class of compounds in crude oil whose surface activity is important for establishing reservoir rock wettability which impacts reservoir drainage. While many phenomenological interfacial studies with crude oils and asphaltenes have been reported, there is very little known about the molecular level interactions between asphaltenes and mineral surfaces. In this study, we analyze Langmuir-Blodgett films of asphaltenes and related model compounds with sum frequency generation (SFG) vibrational spectroscopy. In SFG, the polarization of the input (vis, IR) and output (SFG) beams can be varied, which allows the orientation of different functional groups at the interface to be determined. SFG clearly indicates that asphaltene polycyclic aromatic hydrocarbons (PAHs) are highly oriented in the plane of the interface and that the peripheral alkanes are transverse to the interface. In contrast, model compounds with oxygen functionality have PAHs oriented transverse to the interface. Computational quantum chemistry is used to support corresponding band assignments, enabling robust determination of functional group orientations.

Detection of tethered biocide moiety segregation to silicone surface using sum frequency generation vibrational spectroscopy

Polymer surface properties are controlled by the molecular surface structures. Sum frequency generation (SFG) vibrational spectroscopy has been demonstrated to be a powerful technique to study polymer surface structures at the molecular level in different chemical environments. In this research, SFG has been used to study the surface segregation of biocide moieties derived from triclosan (TCS) and tetradecyldimethyl (3-trimethoxysilylpropyl) ammonium chloride (C-14 QAS) that have been covalently bound to a poly(dimethylsiloxane) (PDMS) matrix. PDMS materials are being developed as coatings to control biofouling. This SFG study indicated that TCS-moieties segregate to the surface when the bulk concentration of TCS-moieties exceeds 8.75% by weight. Surface segregation of C-14 QAS moieties was detected after 5% by weight incorporation into a PDMS matrix. SFG results were found to correlate well with antifouling activity, providing a molecular interpretation of such results. This research showed that SFG can aid in the development of coatings for controlling biofouling by elucidating the chemical structure of the coating surface.

Ultrafast Hot-Carrier Dynamics at Chemically Modified Ge Interfaces Probed by SHG

Time-resolved second-harmonic generation (SHG) was used to study the hot-carrier dynamics and nonlinear optical properties of S-terminated and Cl-terminated Ge(111) interfaces on the femtosecond time scale. The hot-carrier second-order nonlinear optical susceptibilities were determined to be 720 +/- 50 times greater than the valence-band second-order nonlinear optical susceptibilities for the Ge(111)-S system and 880 +/- 100 times greater in the Ge(111)-Cl system. Furthermore, the ground- and excited-state second-order nonlinear optical susceptibilities are suggested to be out of phase for Ge(111)-S and Ge(111)-Cl systems, leading to a pump-induced decrease in the SHG signal as opposed to the increase in the SHG signal observed in the Ge(111)-GeO2 system. Although the SHG response reaches a steady state in 415 +/- 90 fs in the Ge(111)-GeO2 system, a faster response is observed in the Ge(111)-S system, 220 +/- 85 fs, and in the Ge(111)-Cl system, 172 +/- 50 fs. This suggests significantly faster carrier cooling at the Ge(111)-Cl and Ge(111)-S interfaces, with significant implications for hot-carrier mediated device degradation, and migration to high-K dielectrics.

Trend to better nutrition on Australian hospital menus 1986-2001 and the impact of cook-chill food service systems

OBJECTIVE

To assess trends in the nutritional quality of hospital menus and examine differences between menus used in hospitals with cook-chill or cook-fresh food services.

DESIGN

Standard patient menus were analysed against 28 criteria to assess nutritional standards and compared with results from similar studies in 1986 and 1993.

SETTING

Menus were collected from 80 hospitals in New South Wales (NSW), Australia, including 36 using cook-chill food service systems.

STATISTICAL ANALYSIS

Chi-squared analysis was used to assess differences between the proportions of hospitals meeting the criteria in 1993 and 2001, and between different types of hospitals.

RESULTS

In 2001, compared with 1993, significantly many hospitals offered more than one hot choice at the evening meal, more menus highlighted low fat items and more calcium-rich foods were available. More than 90% of hospitals allowed patients to select their own menu, offered wholemeal breads and high-fibre breakfast cereals, fresh fruit, polyunsaturated margarine, a milk dessert at least once a day and two or more hot options at the midday meal. Hospitals with cook-chill food services had menus that were more likely to meet nutritional recommendations, although they were less likely to offer a choice of serving size. A high proportion of unpopular choices were offered in menus, especially meat dishes and desserts.

APPLICATIONS/CONCLUSION

Since 1986, NSW hospital menus have improved to offer choices that conform better to dietary guidelines. Cook-chill food services may have positive and negative impacts on meal choices. The assessment criteria are useful in hospitals to assess their menus.

Development and implementation of computerized clinical guidelines: barriers and solutions

Research indicates that computerized decision support systems (CDSSs) can improve clinical performance and patient outcomes, and yet CDSSs are not in widespread use. Physician guidelines, in general, face barriers in implementation. Guidelines in a computerized format can overcome some of the barriers to conventional text-form guidelines; however, computerized programs have novel aspects that have to be considered, aspects such as technical problems/support and user interface issues that can act as barriers. Though the literature points out that human, organizational, and technical issues can act as barriers in the implementation of CDSSs, studies clearly indicate that there are methods that can overcome these barriers and improve CDSS acceptance and use. These methods come from lessons learned from a variety of CDSS implementation ventures. Notably, most of the methods that improve acceptance and use of a CDSS require feedback and involvement of end-users. Measuring and addressing physician or user attitudes toward the computerized support system has been shown to be important in the successful implementation of a CDSS. This article discusses: 1) the barriers of implementation of guidelines in general and of CDSSs; 2) the importance of the physician's role in development, implementation, and adherence; 3) methods that can improve CDSS acceptance and use; and 4) the types of tools needed to obtain end-user feedback.

Factors affecting nonmedical participants' allocation of scarce medical resources

This study was designed to determine the factors that affect nonmedical participants' judgments in constructing a ranked waiting list for kidney patients requiring dialysis. Participants (N=167) were given a questionnaire that provided minimal demographic data about 16 hypothetical patients. Participants were requested to rank patients in order of priority for treatment. Each participant's personal demographic details were also obtained. Patients differed on four dimensions: gender, income, alcohol consumption, and religious beliefs, yielding a 2x2x2x2 design. The participants favoured for treatment included females over males, "poor" over "rich," nondrinkers over drinkers, and Christians over atheists. Results are discussed in terms of establishing democratic criteria and informing medical personnel on explicit factors which may affect their decision making, thus guarding against biases in judgment.

Agreement between troponin T levels from plain and heparinized tubes

OBJECTIVE

To determine whether there was a clinically significant effect on troponin T measurement when the sample was collected in a heparinized (plasma) blood collection tube compared with a serum tube.

METHODS

Prospective cohort study using a convenience sample of 198 patients with undifferentiated illness presenting to an Emergency Department who required troponin T measurement. Samples were collected in both plain (serum) tubes and plasma tubes for comparison. All samples were measured using an Elecsys 2010 Immunoassay system (Roche-Boehringer Mannheim, Germany).

RESULTS

There were 35 troponin T measurements > or = 0.03 microg/L (the limit of reproducibility of the test). The negative predictive value for troponin T performed in heparinized tubes compared with plain tubes was 100% (95% confidence interval 96.4-100) at the > or = 0.03 microg/L level and 100% (95% confidence interval 97-100%) at the > or = 0.1 microg/L level. At a cut-off point for risk stratification in acute coronary syndromes (> or = 0.1 microg/L), there was 100% concordance between the two measurements for each sample.

CONCLUSION

The use of plasma (heparinized) tubes for the collection of troponin T samples is unlikely to produce clinically significant false-negative results compared with collection of troponin T samples in serum (plain) tubes.

Scaling-up production of recombinant AAV vectors for clinical applications

Recombinant adeno-associated virus (AAV)-based vectors capable of expressing therapeutic gene products in vivo have shown significant promise for human gene therapy. A major challenge for these applications is the development of processes to enable production of large quantities of AAV vectors and purification of material that is well characterized and appropriate for parenteral administration. Several cell culture systems have been developed for AAV vector production, and a limited number of these demonstrate the potential to generate AAV vectors at concentrations compatible with cost-effective large-scale production. Vector purification protocols, in particular those based on the use of scalable column chromatography, have concurrently been developed that demonstrate the potential to provide highly purified AAV vector preparations with high yield. These advances support the potential for AAV vectors as therapeutic agents for gene therapy.

Decisions concerning the allocation of scarce medical resources

This paper aimed to determine the criteria participants use to make decisions about scarce medical resources (allocation to use a kidney machine). It varied information about patients on 4 factors (sex, smoking, employment status, community service). It also set out to see if decisions made in groups differed from aggregated decisions of those made alone. In the first study, participants completed a simple questionnaire requiring them to rank-order sixteen hypothetical patients. In the second study, a group discussion (in groups of three participants) preceded the group putting an agreed rating on the identical questionnaire. Participants favoured patients who were employed, non-smokers and participated in community service. This suggests that participants adopted a utilitarian moral ideology. Participants' smoking habits interacted with the hypothetical patients' smoking habits, indicating in-group favouritism. In the second study it was found that when the decision was made in a group of three it amplifies the decision made by an individual. In this sense there was clear evidence of group polarization.

Evidence for gene transfer and expression of factor IX in haemophilia B patients treated with an AAV vector

Pre-clinical studies in mice and haemophilic dogs have shown that introduction of an adeno-associated viral (AAV) vector encoding blood coagulation factor IX (FIX) into skeletal muscle results in sustained expression of F.IX at levels sufficient to correct the haemophilic phenotype. On the basis of these data and additional pre-clinical studies demonstrating an absence of vector-related toxicity, we initiated a clinical study of intramuscular injection of an AAV vector expressing human F.IX in adults with severe haemophilia B. The study has a dose-escalation design, and all patients have now been enrolled in the initial dose cohort (2 x 10(11) vg/kg). Assessment in the first three patients of safety and gene transfer and expression show no evidence of germline transmission of vector sequences or formation of inhibitory antibodies against F.IX. We found that the vector sequences are present in muscle by PCR and Southern-blot analyses of muscle biopsies and we demonstrated expression of F.IX by immunohistochemistry. We observed modest changes in clinical endpoints including circulating levels of F.IX and frequency of FIX protein infusion. The evidence of gene expression at low doses of vector suggests that dose calculations based on animal data may have overestimated the amount of vector required to achieve therapeutic levels in humans, and that the approach offers the possibility of converting severe haemophilia B to a milder form of the disease.

Adenovirus-mediated expresssion of the murine ecotropic receptor facilitates transduction of human hematopoietic cells with an ecotropic retroviral vector

One factor limiting the ability to modify human repopulating hematopoietic cells genetically with retroviral vectors is the relatively low expression of the cognate viral receptor. We have tested sequential transduction of human hematopoietic cells with an adenoviral vector encoding the ecotropic retroviral receptor followed by transduction with an ecotropic retroviral vector. Adenoviral transduction of K562 erythroleukemia cells was highly efficiently with >95% of cells expressing the ecotropic receptor at a multiplicity of infection (MOI) of 103with a correspondingly high transduction with a retroviral vector. Ecotropic receptor expression in CD34+ cells following transduction with adenoviral vectors was increased by at least two-fold (from 20 to 48%) by replacing the RSV promoter with the CMV E1a promoter, resulting in a parallel increase in retroviral transduction efficiency. Replacing the head portion of the fiber protein in conventional adenoviral vectors (serotype 5) with the corresponding portion from an adenoviral 3 serotype resulted in ecotropic receptor expression in 60% of CD34+ cells at an MOI of 104 and a retroviral transduction of 60% of hematopoietic clonogenic progenitors. The sequential transduction strategy also resulted in efficient transduction of the primitive CD34+CD38- subset suggesting that it may hold promise for genetic modification of human hematopoietic stem cells.

Expression of tissue inhibitor of matrix metalloproteinases 1 by use of an adenoviral vector inhibits smooth muscle cell migration and reduces neointimal hyperplasia in the rat model of vascular balloon injury

BACKGROUND

Cell migration is a major contributor to injury-induced neointimal hyperplasia and depends on alteration of the proteolytic balance within the arterial wall toward matrix breakdown. This is partly mediated by the matrix metalloproteinases (MMPs) and their natural inhibitors, the tissue inhibitors of metalloproteinases (TIMPs).

METHODS AND RESULTS

An increase in expression of biologically active and immunoreactive TIMP-1 was seen in vitro after infection of rat smooth muscle cells (SMCs) with Av1.TIMP1 (an adenoviral vector containing the human TIMP1 cDNA). Infection of rat SMCs with Av1.TIMP1 reduced migration in vitro by 27% compared with control virus-infected cells (37.6+/-4.34 versus 51+/-5.01 cells per high-power field, P<0.05). The adenoviral vector was delivered to the injured rat carotid artery, and 4 days later, immunoreactive protein was identified and migration of SMCs reduced by 60% (5.2+/-0. 5 versus 12.8+/-1.5 cells per section, P<0.05, n=5). Neointimal area 14 days after injury showed a 30% reduction in the animals receiving the Av1.TIMP1 virus compared with controls (0.09+/-0.01 versus 0. 14+/-0.01 mm2, P=0.02, n=14).

CONCLUSIONS

The response to arterial balloon injury involves MMP-dependent SMC migration and can be attenuated in vivo by the transmural expression of TIMP-1 by adenoviral gene transfer.

Enhanced neuroblastoma transduction for an improved antitumor vaccine

BACKGROUND

A recent clinical trial of an antineuroblastoma vaccine used adenovirus serotype 5 (Ad5) vectors to transduce autologous tumor cells with the gene encoding IL-2. A method to improve transduction efficiency was sought to enable the use of lower viral titers, especially when in situ adenoviral-mediated tumor cell transduction is considered.

MATERIALS AND METHODS

A chimeric adenoviral delivery vector was utilized in which the fiber head from adenovirus serotype 3 was incorporated into the backbone of Ad5. Since the fiber head protein is responsible for viral attachment to target cells, a different spectrum and range of infectivity might result. Both the chimeric (Av9LacZ4) and Ad5 (Av1LacZ4) vectors were constructed to carry a beta-galactosidase transgene. The relative transduction efficiency of these two vectors was then evaluated in five tumor-derived short-term neuroblastoma cultures and four established neuroblastoma cell lines. Enzyme activity was assessed using three different methods: in situ staining, flow cytometric analysis, and a quantitative assay.

RESULTS

A significant improvement in transduction efficiency of the short-term neuroblastoma cultures with the new chimeric adenovector was demonstrated. A similar improvement in transduction efficiency was not observed in the established cell lines, suggesting that the cell surface receptor for the Ad 3 serotype had been lost in vitro. Increased transduction of tumor cells with N-myc amplification was also observed.

CONCLUSIONS

The newly constructed chimeric adenoviral vector transduces short-term neuroblastoma cultures more efficiently than the standard Ad5 vector. This vector will permit the use of lower viral titers and may be useful in other adenoviral-based gene-therapy protocols. Increased transgene expression in N-myc-amplified cells offers possible selectivity for in situ gene delivery.

Evidence for a grammar-specific deficit in children

BACKGROUND

Specific language impairment (SLI) is a disorder in which language acquisition is impaired in an otherwise normally developing child. SLI affects around 7% of children. The existence of a purely grammatical form of SLI has become extremely controversial because it points to the existence and innateness of a putative grammatical subsystem in the brain. Some researchers dispute the existence of a purely grammatical form of SLI. They hypothesise that SLI in children is caused by deficits in auditory and/or general cognitive processing, or social factors. There are also claims that the cognitive abilities of people with SLI have not yet been sufficiently characterised to substantiate the existence of SLI in a pure grammatical form.

RESULTS

We present a case study of a boy, known as AZ, with SLI. To investigate the claim for a primary grammatical impairment, we distinguish between grammatical abilities, non-grammatical language abilities and non-verbal cognitive abilities. We investigated AZ's abilities in each of these areas. AZ performed normally on auditory and cognitive tasks, yet exhibited severe grammatical impairments. This is evidence for a developmental grammatical deficit that cannot be explained as a by-product of retardation or auditory difficulties.

CONCLUSIONS

The case of AZ provides evidence supporting the existence of a genetically determined, specialised mechanism that is necessary for the normal development of human language.

Circumvention of immunity to the adenovirus major coat protein hexon

Immunity to adenoviruses is an important hurdle to be overcome for successful gene therapy. The presence of antibodies to the capsid proteins prevents efficacious adenovirus vector administration in vivo. We tested whether immunity to a particular serotype of adenovirus (Ad5) may be overcome with a vector that encodes the hexon sequences from a different adenovirus serotype (Ad12). We successfully constructed an adenovirus vector with a chimeric Ad5-Ad12 hexon which was not neutralized by plasma from C57BL/6 mice immunized with Ad5. The vector was also capable of transducing the livers of C57BL/6 mice previously immunized with Ad5.

Sustained phenotypic correction of murine hemophilia A by in vivo gene therapy

Hemophilia A is caused by a deficiency of blood coagulation factor VIII (FVIII) and has been widely discussed as a candidate for gene therapy. While the natural canine model of hemophilia A has been valuable for the development of FVIII pharmaceutical products, the use of hemophiliac dogs for gene therapy studies has several limitations such as expense and the long canine generation time. The recent creation of two strains of FVIII-deficient mice provides the first small animal model of hemophilia A. Treatment of hemophiliac mice of both genotypes with potent, human FVIII-encoding adenoviral vectors resulted in expression of biologically active human FVIII at levels, which declined, but remained above the human therapeutic range for over 9 months. The duration of expression and FVIII plasma levels achieved were similar in both hemophiliac mouse strains. Treated mice readily survived tail clipping with minimal blood loss, thus showing phenotypic correction of murine hemophilia A by in vivo gene therapy.

Surface expression of intercellular adhesion molecule 1 on epithelial cells in the human adenoid

Human rhinoviruses enter the host by way of the nose and conjunctiva. Intercellular adhesion molecule 1 (ICAM-1) is the cellular receptor for the majority of rhinoviruses. ICAM-1 expression on the luminal surface of epithelial cells in the upper airway may be an important determinant of virus localization in the airway. Eighteen adenoids and 5 nasopharyngeal biopsies were evaluated by immunohistochemistry for surface expression of ICAM-1. Heavy immunoreactivity of ICAM-1 was found on the surface of a small number of single nonciliated cells in the lymphoepithelium. Squamous epithelial cells showed minimal to no staining, and ciliated epithelium had positive ICAM-1 staining of the basal cells but not on the ciliated border. The localization of ICAM-1 expression to specific, limited areas of the surface epithelium of the nasopharynx may have important implications in the pathogenesis of rhinovirus infections, especially initiation of the host response to rhinovirus.

Expression of human cholesterol 7alpha-hydroxylase in atherosclerosis-susceptible mice via adenovirus infection

Adenovirus is a vector for the delivery of genes mainly to the liver. Short-term (approximately 3 days) studies using adenovirus transfection have provided valuable insights into how genes can complement normal and pathological phenotypes. When atherosclerosis-susceptible C57BL/6 mice were infected with an adenovirus vector containing the human 7alpha-hydroxylate cDNA (AV17h1) and fed on a chow diet, human 7alpha-hydroxylase mRNA and enzyme activity doubled compared with that in mice infected with an adenovirus vector (AV1Null) alone. In AV17h1-infected mice fed on a high fat cholic acid (HFCA) diet, mRNA expression and activity of both the endogenous and adenovirus (human) 7alpha-hydroxylase were repressed. AV17h1-infected mice fed on a HFCA diet and killed at mid-light had increased 7alpha-hydroxylase activity and mRNA compared with mice killed at mid-dark. Since expression of AV17h1 is driven by a constitutive Rous sarcoma virus promoter, the repression of human 7alpha-hydroxylase by the HFCA diet was unexpected. In spite of this post-transcriptional repression by the HFCA diet, AV17h1-infected mice expressed the human 7alpha-hydroxylase mRNA, causing its enzyme activity to be 3-fold greater than in AV1Null-infected mice. In AV17h1-infected mice, the 7alpha-hydroxylase enzyme activity varied as a linear function of human mRNA abundance. In conclusion, the accumulation of apolipoprotein B-containing lipoproteins in plasma of C57BL/6 mice fed on the HFCA diet was not reduced by longer-term (2 weeks) 7alpha-hydroxylase expression, probably because of its diminished expression caused by the diet and hepatic inflammation from the adenovirus infection. These results may suggest that adenovirus is effective in promoting longer-term (2 weeks) expression of 7alpha-hydroxylase.

Selective targeting of human cells by a chimeric adenovirus vector containing a modified fiber protein

The adenovirus fiber protein is responsible for attachment of the virion to unidentified cell surface receptors. There are at least two distinct adenovirus fiber receptors which interact with the group B (Ad3) and group C (Ad5) adenoviruses. We have previously shown by using expressed adenovirus fiber proteins that it is possible to change the specificity of the fiber protein by exchanging the head domain with another serotype which recognizes a different receptor (S. C. Stevenson et al., J. Virol. 69:2850-2857, 1995). A chimeric fiber cDNA containing the Ad3 fiber head domain fused to the Ad5 fiber tail and shaft was incorporated into the genome of an adenovirus vector with E1 and E3 deleted encoding beta-galactosidase to generate Av9LacZ4, an adenovirus particle which contains a chimeric fiber protein. Western blot analysis of the chimeric fiber vector confirmed expression of the chimeric fiber protein and its association with the adenovirus capsid. Transduction experiments with fiber protein competitors demonstrated the altered receptor tropism of the chimeric fiber vector compared to that of the parental Av1LacZ4 vector. Transduction of a panel of human cell lines with the chimeric and parental vectors provided evidence for a different cellular distribution of the Ad5 and Ad3 receptors. Three cell lines (THP-1, MRC-5, and FaDu) were more efficiently transduced by the vector containing the Ad3 fiber head than by the Ad5 fiber vector. In contrast, human coronary artery endothelial cells were transduced more readily with the vector containing the Ad5 fiber than with the chimeric fiber vector. HeLa and human umbilical vein endothelial cells were transduced at equivalent levels compared with human diploid fibroblasts, which were refractory to transduction with both vectors. These results provide evidence for the differential expression of the Ad5 and Ad3 receptors on human cell lines derived from clinically relevant target tissues. Furthermore, we show that exchange of the fiber head domain is a viable approach to the production of adenovirus vectors with cell-type-selective transduction properties. It may be possible to extend this approach to the use of ligands for a range of different cellular receptors in order to target gene transfer to specific cell types at the level of transduction.

Prevention of rhinovirus infection in chimpanzees by soluble intercellular adhesion molecule-1

Intercellular adhesion molecule-1 (ICAM-1) is the cell surface receptor for the major class of human rhinoviruses, and tICAM453, a truncated, soluble form of ICAM-1, has been shown previously to be a potent in vitro inhibitor of rhinovirus. In this report, we have investigated the in vivo efficacy of tICAM453 for the prophylaxis of rhinovirus serotype 16 infection in the chimpanzee. Because chimpanzees do not show clinical symptoms of infection after rhinovirus challenge, infection was followed by measuring antirhinovirus serum antibody responses and detection of virus shedding. By both of these measures, intranasal application of tICAM453 was efficacious in preventing rhinovirus infection in chimpanzees subsequently challenged with infectious doses of virus. These results suggest that the use of soluble rhinovirus receptor to inhibit virus binding to host cells should be feasible in humans.

Complete short-term correction of canine hemophilia A by in vivo gene therapy

Hemophilia A is a severe bleeding disorder caused by a deficiency in clotting factor VIII (FVIII). A canine model that closely mimics the human disease was used to determine if an adenoviral vector expressing a human FVIII cDNA could be used to correct the hemophilia A phenotype. Within 48 hours after peripheral vein administration of the vector to FVIII-deficient dogs, the hemophilic phenotype was corrected, based on determination of the activated clotting time, the activated partial thromboplastin time, and the cuticle bleeding time. Direct measurement of human FVIII in the dog plasma showed FVIII expression at amounts well above the human therapeutic level. FVIII expression in treated dogs was short-term, lasting 1 to 2 weeks, due to the development of a human FVIII-specific inhibitor antibody response. These data provide the first demonstration of in vivo gene therapy of hemophilia A.

Sustained expression of therapeutic levels of human factor VIII in mice

Deficiency of coagulation factor VIII (FVIII) results in hemophilia A, a common hereditary bleeding disorder. Using a human FVIII-encoding adenoviral vector, Av1ALAPH81, we have demonstrated expression of therapeutic levels of human FVIII in mice sustained for more than 5 months after vector administration. Administration of a high dose (4 x 10(9) plaque-forming units [pfu]) of Av1ALAPH81 to mice resulted in a peak expression of 2,063 ng/mL of human FVIII in the mouse plasma, with levels decreasing to background by weeks 15 to 17. Normal FVIII levels in humans range from 100 to 200 ng/mL and therapeutic levels are as low as 10 ng/mL. Alternatively, administration of 8- to 80-fold lower vector doses (5 x 10(8) pfu to 5 x 10(7) pfu) to normal adult mice resulted in expression of FVIII at therapeutic levels sustained for at least 22 weeks. Detailed analysis of vector toxicity indicated that the high vector dose caused a dramatic elevation of liver-specific enzyme levels, whereas an eight-fold lower vector dose was significantly less hepatotoxic. The data presented here demonstrate that administration of lower, less toxic vector doses allow long-term persistence of FVIII expression.

Transient immunosuppression permits successful repetitive intravenous administration of an adenovirus vector

The in vivo administration of adenovirus vectors frequently elicits a neutralizing antibody response which eliminates or substantially reduces the efficacy of subsequent treatments. Methods to overcome this significant barrier to repeat delivery will be required for the application of adenovirus-based gene therapy in the treatment of chronic disease. We have evaluated the relationship between the initial vector dose and the effectiveness of a second vector administration. C57BL/6 mice injected intravenously with up to 10(7) p.f.u. of a lacZ adenovirus vector, Av1lacZ4, expressed significant levels of human factor IX when injected with 2 x 10(8) p.f.u. of the factor IX vector, Av1H9F, 5 weeks later. An initial dose of 10(8) p.f.u. of Av1lacZ4 completely prevented expression of factor IX following the second administration due to the generation of neutralizing antibody. However, transient immunosuppression with deoxyspergualin (DSG) or cyclophosphamide at the time of initial exposure to 10(8) p.f.u. of Av1lacZ4 prevented the formation of anti-adenovirus neutralizing antibody and permitted an effective second administration of a factor IX vector. Furthermore, transient immunosuppression with cyclophosphamide concomitant with delivery of the factor IX vector enabled an effective administration of a third vector encoding human factor VIII. This approach, together with strategies to prolong the persistence of adenoviral vector expression, should permit long-term therapy with adenovirus-based vectors.

High-level tissue-specific expression of functional human factor VIII in mice

Hemophilia A results from subnormal levels of blood coagulation factor VIII (FVIII) and is an attractive target for gene therapy. However, progress has been impeded by features of FVIII biology such as low mRNA accumulation and the instability of the protein. We have shown previously that a FVIII adenoviral vector, Av1ALH81, allowed high-level expression of human FVIII in mice sustained for several weeks. Here, we have generated a second FVIII adenoviral vector, Av1ALAPH81, in which an intron was introduced into the FVIII expression cassette. Administration of Av1ALAPH81 to mice resulted in significantly increased FVIII plasma levels, 1,046 +/- 163 ng/ml compared to 307 +/- 93 ng/ml of FVIII detected in mice that received Av1ALH81. Normal FVIII levels in humans are 100-200 ng/ml and therapeutic levels are as low as 10 ng/ml. Therapeutic levels are defined as the amount of FVIII necessary to convert severe hemophilia to a moderate or mild hemophiliac condition. The increased potency of the second FVIII adenoviral vector allowed the administration of significantly lower, less toxic vector doses, while retaining the potential for high FVIII expression. Furthermore, we demonstrate that adenoviral-mediated expression of human FVIII can be limited to the liver by inclusion of a liver-specific promoter, thereby achieving the first step in regulated expression of human FVIII in vivo.

Human adenovirus serotypes 3 and 5 bind to two different cellular receptors via the fiber head domain

The adenovirus fiber protein is responsible for attachment of the virion to cell surface receptors. The identity of the cellular receptor which mediates binding is unknown, although there is evidence suggesting that two distinct adenovirus receptors interact with the group C (adenovirus type 5 [Ad5]) and the group B (Ad3) adenoviruses. In order to define the determinants of adenovirus receptor specificity, we have carried out a series of competition binding experiments using recombinant native fiber polypeptides from Ad5 and Ad3 and chimeric fiber proteins in which the head domains of Ad5 and Ad3 were exchanged. Specific binding of fiber to HeLa cell receptors was assessed with radiolabeled protein synthesized in vitro, and by competition analysis with baculovirus-expressed fiber protein. Fiber produced in vitro was found as both monomer and trimer, but only the assembled trimers had receptor binding activity. Competition data support the conclusion that Ad5 and Ad3 interact with different cellular receptors. The Ad5 receptor distribution on several cell lines was assessed with a fiber binding flow cytometric assay. HeLa cells were found to express high levels of receptor, while CHO and human diploid fibroblasts did not. A chimeric fiber containing the Ad5 fiber head domain blocked the binding of Ad5 fiber but not Ad3 fiber. Similarly, a chimeric fiber containing the Ad3 fiber head blocked the binding of labeled Ad3 fiber but not Ad5 fiber. In addition, the isolated Ad3 fiber head domain competed effectively with labeled Ad3 fiber for binding to HeLa cell receptors. These results demonstrate that the determinants of receptor binding are located in the head domain of the fiber and that the isolated head domain is capable of trimerization and binding to cellular receptors. Our results also show that it is possible to change the receptor specificity of the fiber protein by manipulation of sequences contained in the head domain. Modification or replacement of the fiber head domain with novel ligands may permit adenovirus vectors with new receptor specificities which could be useful for targeted gene delivery in vivo to be engineered.

Endorsement and memory bias of self-referential pain stimuli in depressed pain patients

This study investigates information processing in chronic pain patients by comparing the responses of depressed pain patients, non-depressed pain patients and non-pain control subjects. Each subject contributed two scores: endorsement of adjectives as descriptors of themselves and their best-friends; and free recall of the presented words. The stimuli consisted of depression-related, pain-related and neutral control adjectives, and each content category was split into negative and positive valence. The four-way interaction between group, reference, content and valence was significant both in the recall data and the endorsement data. Further analysis revealed that depressed pain patients exhibited a bias towards self-referential negative pain words, but not towards self-referential negative depression information. These results are interpreted in line with content specificity theory of information processing and have implications for targeting cognitive interventions with pain patients.

Phenotypic correction of hypercholesterolemia in apoE-deficient mice by adenovirus-mediated in vivo gene transfer

To investigate the potential use of apoE in gene therapy of hyperlipidemias, an adenoviral vector was constructed that contained the human apoE3 cDNA under the control of the RSV promoter (Av1RE). Transduction of HepG2 cells resulted in the overexpression of human apoE secreted into the culture medium. Intravenous injection of 5 x 10(11) Av1RE vector particles into apoE-deficient mice resulted in expression of human apoE3 in mouse plasma at levels of 1.2 +/- 0.4 micrograms/L (mean +/- SEM, n = 5) 7 days after injection. Mice injected with the control vector Av1Lacz4 did not express detectable levels of human apoE. Average plasma cholesterol concentrations were reduced approximately eightfold from 737.5 +/- 118 mg/dL (mean +/- SEM, n = 6) to 98.2 +/- 4.4 mg/dL (mean +/- SEM, n = 5) and were unaffected in the control vector group. Expression of human apoE resulted in a shift in the plasma lipoprotein distribution from primarily VLDL and LDL in the control mice to predominantly HDL in the Av1RE-treated group. Western blot analysis of fast protein liquid chromatography-fractionated mouse plasma showed that the human apoE protein was associated with VLDL, LDL, and HDL. Correction of the hyperlipidemic condition found in the apoE-knockout mouse strain by direct in vivo gene transfer establishes the potential of this approach for treatment of hyperlipidemia caused by apoE deficiency or malfunction in human disease.

In vivo gene delivery and expression of physiological levels of functional human factor VIII in mice

Hemophilia A is caused by blood coagulation factor VIII (FVIII) deficiency and is an attractive target for gene therapy. However, features of FVIII physiology, such as the instability of the mRNA and protein, have provided obstacles to the design of a feasible strategy for the transfer and expression of the human FVIII gene in vivo. We have constructed a recombinant adenoviral vector, Av1ALH81, that contains the human FVIII cDNA from which the B-domain has been deleted (BDD FVIII) and extensively characterized this vector in vitro and in vivo. In vitro, HepG2, human hepatoma cells, transduced with Av1ALH81 secreted high levels of biologically active human BDD FVIII measured by the Coatest bioassay (> 2,400 mU per 10(6) cells per 24 hr). Administration of Av1ALH81 to mice, via tail vein, resulted in expression of human BDD FVIII in the mouse plasma at levels averaging 307 +/- 93 ng/ml 1 week post-injection, measured by a sensitive human FVIII-specific ELISA. Normal FVIII levels in humans are 100-200 ng/ml, and therapeutic levels are as low as 10 ng/ml. Purification of the human FVIII from the mouse plasma, and subsequent Coatest analysis, revealed that the human FVIII produced in the mice was biologically active. In addition, the duration of FVIII expression in vivo was followed, and high-level FVIII expression was sustained over a period of several weeks. The finding that an adenoviral vector can mediate high-level expression of human FVIII in an animal model provides the basis for the development of gene therapy for hemophilia A.

Interpretation bias in responses to ambiguous cues in pain patients

Pain patients and control subjects responses to ambiguous cues were compared in two separate investigations. In the first, pain patients, control subjects and physiotherapists were asked to produce a list of spontaneous associations to ambiguous cues (such as terminal and growth). To control for mood effects the experiment was repeated with three more groups: Pain patients, osteopaths and a control group. Measures of anxiety and depression were incorporated in the analysis. Results indicate that pain patients systematically produce more pain related associations than the other groups, and that this effect is independent of anxiety and depression levels. The discussion concentrates on the implications of these findings both for the theory of pain processing and for clinical interventions.

Crystallographic and cryo EM analysis of virion-receptor interactions

Cryoelectron microscopy has been used to determine the first structure of a virus when complexed with its glycoprotein cellular receptor. Human rhinovirus 16 (HRV16) complexed with the two amino-terminal, immunoglobulin-like domains of the intercellular adhesion molecule-1 (ICAM-1) shows that ICAM-1 binds into the 12 A deep "canyon" on the surface of the virus. This is consistent with the prediction that the viral receptor attachment site lies in a cavity inaccessible to the host's antibodies. The atomic structures of HRV14 and CD4, homologous to HRV16 and ICAM-1, showed excellent correspondence with observed density, thus establishing the virus-receptor interactions.