Validation of a pandemic-proof, decentralized cardiovascular trial: scalable design produces rapid recruitment, high engagement and protocol adherence in DeTAP (Decentralized Trial in Afib Patients)

Background

The COVID-19 pandemic has curtailed clinical trial activity significantly. Decentralized clinical trial (DCT) designs may lower cost, expand trial access, and reduce exposure risk for patients and staff. Whether such designs can be used for large, pivotal drug trials is not known.

Purpose

We performed a feasibility study to inform whether a large phase 3 Cardiovascular DCT can achieve high quality trial results and also withstand health crises such as the COVID-19 pandemic. The DeTAP (Decentralized Trial in Afib Patients) was a single-arm, observational study that integrated a suite of digital health technologies, including paired home sensor devices, into a 100% virtual trial experience for atrial fibrillation (AF) patients on anticoagulation.

Methods

We recruited 100 AF patients over age 55 on oral anticoagulation (OAC) by traditional methods or by social media ads placed California-wide. Subjects completed an online prescreening, uploaded their active OAC prescription, and completed an e-consent via SMS message link. Participants downloaded a customized study app to integrate surveys and data from study-supplied wireless blood pressure (BP) and 6 lead EKG sensors (Figure 1A). Participants completed pre- and post-study engagement surveys, weekly OAC adherence surveys, 4 study televisits, 4 ECG/BP readings, and 4 post-study surveys over a 6 month period. The primary endpoints were protocol engagement-based measurements that quantified percent completion of: 1) televisits 2) surveys, 3) ECG/BP readings requirements. Secondary endpoints were the % changes in: 1) OAC adherence (OACA), 2) nuisance bleeding (NB), 3) individual patient engagement surveys.

Results

100 participants were recruited in 26 days (traditional: 6 in 2 weeks; social media: 94 in 12 days) with a dramatic surge in enrollment driven by social media ads (Figure 1B, Table). A recruitment overflow occurred with >200 eligible candidates on a waitlist. All key study completion metrics showed high compliance: televisit (91%); surveys (85%); ECG/BP completion (90%). Overall OACA was unchanged, but for subjects who reported low initial OACA, there was significant improvement at 6 months (85±16% to 98±6%; p=0.002). 47 participants (57%) reported NB, which did not correlate with OACA. Participant engagement measure scores (PAM-13) trended higher (baseline, 70%; 6 months, 74%, p=0.32). Lastly, study participants exhibited strong interest in participating in a larger experimental drug DCT study (90%) in the future.

Conclusion

The DeTAP study, conducted fully during the COVID-19 pandemic, demonstrates that a decentralized CV medical intervention trial is feasible and can achieve rapid recruitment, high study retention, physiologic and adverse event reporting, and high study engagement via the proper integration of digital technologies and a dedicated DCT study coordination effort. These findings could be informative for virtualizing large pivotal clinical trials at scale.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): Bayer AG Figure 1. DeTAP Study Design and Recruitment TimelineTable 1. DeTAP Results

Herpes zoster in outpatient departments of healthcare centers in India: a review of literature

In India, although incidence of Herpes zoster has not been assessed, regional cases have been reported. We revisited the peer-reviewed literature on clinical cases of HZ to depict the trends in population characteristics, disease presentation, and predisposing factors for the disease in India. Systematically conducted literature search yielded 27 studies, published between January 2011 and May 2020, reporting 3124 HZ clinical cases, with high proportions in older adults (>50 years of age: 15.0–81.3%). Thoracic dermatome was consistently reported as the most frequent site affected by HZ (38.9–71.0%). Post-herpetic neuralgia and secondary bacterial infections were the two most frequent complications (10.2–54.7% and 3.5–21.0%, respectively). Despite the paucity of data and gaps in the reporting of HZ cases, available evidence indicate that the disease causes an important burden to older adults in India, suggesting that preventive strategies, along with recommendations to healthcare practitioners, can help mitigate the burden of HZ.

What is the context?

Herpes zoster is caused by reactivation of the varicella virus in sensory gangila usually during older age.

The most common complication involve skin and neurological disorders, such as post herpetic neuralgia.

Herpes zoster can impact quality of life for months or even years (especially for those >50 years of age).

In India, there is a lack of population-based studies on herpes zoster to reflect burden of disease.

What is new?

We reviewed the literature on clinical cases of herpes zoster in India from last decade and found that:

High propotions of older adults (>50 years of age) are reported to have the disease.

Thoracic dermatomes and post herpetic neuralgia are common clinical presentation and complication.

Post herpetic neuralgia is observed more frequently in older patients.

What is the impact?

Our review highlights sigificant number of cases of herpes zoster are reported and the disease causes a substantial burden to older adults in India.

In view of the growing elderly population in India, the finding of greater proportion of cases in >50 years of age holds importance.

Implementation of preventive strategies along with guidance to healthcare pracitioners can help prevent the disease and complications in vulnerable population.

Vaccination in preterm and low birth weight infants in India

In India, the high neonatal and infant mortality rate is due in part to an increasing number of preterm and low birth weight (LBW) infants. Given the immaturity of immune system, these infants are at an increased risk of hospitalization and mortality from vaccine-preventable diseases (VPDs). In this narrative review, we screened the scientific literature for data on the risk of VPDs, vaccination delay and factors related to it in Indian preterm and LBW infants. Although routine childhood vaccinations are recommended regardless of gestational age or birth weight, vaccination is often delayed. It exposes these infants to a higher risk of infections, their associated complications, and death. After-birth complications, lack of awareness of recommendations, vaccine efficacy and effectiveness and concerns related to safety are some of the common barriers to vaccination. Awareness campaigns might help substantiate the need for (and value of) vaccination in preterm and LBW infants.

What is the context?

In India, the high neonatal mortality rate is due in part to an increasing number of pretern and low birth weight intants.

Affected infants have a poorly developed inmune system and are more susceptible to contracting vaccine-preventable diseases.

The Indian Academy of Pediatrics recommends vaccination according to the same schedule used for full term infants, following chronological (not gestational) age.

Delays in vaccinations increase the risk of preventable infections.

What is new?

Our review of the scientific literature shows that, in India:

infections have more serious conseuences in preterm and low birth weight infants

delays to vaccinate affected infants are common, mostly due to safety and effectiveness concerns from parents and healthcare pracitionrs.

What is the impact?

Improving mternal nutritional status and immunization, and perinatal care could help reduce the number of preterm and low birth weight infants.

Combining maternal immunization with vaccination of affected infants can confer safe and effective protection.

Awareness campaigns for parents and healthcare practitioners could address the issue of vaccination delay in pretern and low birth weight infants in India.

Towards adult vaccination in India: a narrative literature review

Despite vast improvements in childhood vaccination coverage in India, adult vaccination coverage is negligible. Our aim was, therefore, to create awareness about the importance of adult immunization. Although the true burden of vaccine-preventable diseases (VPDs) among Indian adults is unknown, adults are particularly vulnerable during outbreaks, due to a lack of immunization, waning immunity, age-related factors (e.g. chronic conditions and immunosenescence), and epidemiological shift. There are no national adult immunization guidelines in India, and although several medical societies have published adult immunization guidelines, these vary, making it unclear who should receive which vaccines (based on age, underlying conditions, etc.). Other barriers to adult immunization include vaccine hesitancy, missed opportunities, and cost. Steps to improve adult vaccination could include: adoption of national guidelines, education of healthcare providers and the public, and promotion of life-course immunization. Improving adult vaccine coverage could help reduce the burden of VPDs, particularly among older adults.

Chemoprevention gene therapy (CGT): novel combinatorial approach for preventing and treating pancreatic cancer

Pancreatic cancer remains one of the deadliest of all cancers despite aggressive surgical treatment combined with adjuvant radiotherapy and chemotherapy. Chemoresistance and radioresistance are the principal causes of failure of pancreatic cancer patients to respond to therapy. Conditionally replication competent adenovirus (CRCA)-based cancer gene therapy is an innovative strategy for treating cancers displaying inherent resistance to treatment. Limitations of current adenovirus (Ad)-based gene therapies for malignant tumors include lack of cancer-specificity, and effective and targeted delivery. To remedy this situation, CRCAs have been designed that express E1A, necessary for Ad replication, under the control of a cancer-specific progression elevated gene-3 promoter (PEG-Prom) with concomitant expression of an immunomodulatory cytokine, such as mda-7/IL-24 or interferon-γ (IFN-γ), under the control of a ubiquitous and strong cytomegalovirus promoter (CMV-Prom) from the E3 region. These bipartite CRCAs, when armed with a transgene, are called cancer terminator viruses (CTVs), i.e., Ad.PEG-E1A-CMV-mda-7 (CTV-M7) and Ad.PEG-E1A-CMV-IFN-γ (CTV-γ), because of their universal effectiveness in cancer treatment irrespective of p53/pRb/p16 or other genetic alterations in tumor cells. In addition to their selective oncolytic effects in tumor cells, the potent 'bystander antitumor' properties of MDA-7/IL-24 and IFN-γ embody the CTVs with expanded treatment properties for both primary and distant cancers. Pancreatic cancer cells display a "translational block" of mda-7/IL-24 mRNA, limiting production of MDA-7/IL-24 protein and cancer-specific apoptosis. Specific chemopreventive agents abrogate this "translational block" resulting in pancreatic cancer-specific killing. This novel chemoprevention gene therapy (CGT) strategy holds promise for both prevention and treatment of pancreatic cancers where all other strategies have proven ineffective.

Water desalination using capacitive deionization with microporous carbon electrodes

Capacitive deionization (CDI) is a water desalination technology in which salt ions are removed from brackish water by flowing through a spacer channel with porous electrodes on each side. Upon applying a voltage difference between the two electrodes, cations move to and are accumulated in electrostatic double layers inside the negatively charged cathode and the anions are removed by the positively charged anode. One of the key parameters for commercial realization of CDI is the salt adsorption capacity of the electrodes. State-of-the-art electrode materials are based on porous activated carbon particles or carbon aerogels. Here we report the use for CDI of carbide-derived carbon (CDC), a porous material with well-defined and tunable pore sizes in the sub-nanometer range. When comparing electrodes made with CDC with electrodes based on activated carbon, we find a significantly higher salt adsorption capacity in the relevant cell voltage window of 1.2-1.4 V. The measured adsorption capacity for four materials tested negatively correlates with known metrics for pore structure of the carbon powders such as total pore volume and BET-area, but is positively correlated with the volume of pores of sizes <1 nm, suggesting the relevance of these sub-nanometer pores for ion adsorption. The charge efficiency, being the ratio of equilibrium salt adsorption over charge, does not depend much on the type of material, indicating that materials that have been identified for high charge storage capacity can also be highly suitable for CDI. This work shows the potential of materials with well-defined sub-nanometer pore sizes for energy-efficient water desalination.

Inhibition of AP-1 by SARI negatively regulates transformation progression mediated by CCN1

Enhanced expression of the CCN family of secretory integrin-binding proteins correlates with many essential components of the cancerous state, including tumor cell adhesion, proliferation, invasion and migration. Consequently, CCN1 expression is elevated in various cancers, including breast cancer, and its expression directly correlates with poor patient prognosis. Using subtraction-hybridization, combined with induction of cancer cell terminal differentiation, we cloned SARI (suppressor of activator protein (AP)-1, regulated by interferon (IFN)), an IFN-beta-inducible, potent tumor suppressor gene that exerts cancer-selective growth inhibitory effects. Forced expression of SARI using an adenovirus (Ad.SARI) inhibits AP-1 function and downregulates CCN1 expression in multiple cancer lineages, resulting in a profound inhibition in anchorage-independent cell growth and tumor cell invasion. Overexpression of SARI reduces CCN1-promoter activity through inhibition of AP-1 binding. Accordingly, SARI selectively blocks expression of the transformed state in rat embryo fibroblast cells that stably overexpress c-Jun. These results illustrate that SARI inhibits AP-1 transactivating factor binding to the cis-element of the CCN1 promoter, possibly through its interaction with c-Jun. Overall, SARI can directly inhibit CCN1-induced transformation by inhibiting the transcription of CCN1, as well as indirectly by inhibiting the expression of c-Jun (and hence blocking AP-1 activity). In these contexts, transformed cells 'addicted' to AP-1 activity are rendered susceptible to SARI-mediated inhibition of expression of the transformed phenotype.

Dopaminergic influence on thyrotropin secretion in primary hypothyroidism

This study was conducted to assess the influence of dopamine on thyrotropin secretion in patients with primary hypothyroidism before and after optimized L-thyroxin replacement therapy. Thyrotropin responses to dopamine infusion (4 microg/kg/min over 3 hours) and IV metoclopramide (10 mg bolus), a dopamine receptor blocker were studied in 25 consecutive patients with primary hypothyroidism before and after achieving stable euthyroid state and compared with 15 normal age-matched controls. Thyrotropin response to both dopamine infusion (decremental) and IV metoclopramide bolus (incremental) was greater in patients with primary hypothyroidism than that in the control subjects. Thyrotropin response was greater in women than in men. The magnitude of decremental thyrotropin response to dopamine infusion and the incremental response to IV metoclopramide bolus significantly correlated with the basal T3 and T4 levels. Thyrotropin response was blunted to dopamine infusion but not to metoclopramide at follow-up after six-month replacement with L-thyroxin, and both the responses were comparable in women and men in patient group. We conclude that modulation of dopaminergic system by dopamine or by dopamine receptor blocker has a greater influence on thyrotropin secretion in patients with primary hypothyroidism than euthyroid normal subjects.

Gender influences on sarcoplasmic reticulum Ca2+-handling in failing human myocardium

Gender has recently been implicated as an important modulator of cardiovascular disease. However, it is not known how gender may specifically influence the Ca2+-handling deficits that characterize the depressed cardiac contractility of human heart failure. To elucidate the contributory role of gender to sarcoplasmic reticulum (SR) Ca2+ cycling alterations, the protein levels of SR Ca2+-ATPase (SERCA), phospholamban, and calsequestrin, as well as the site-specific phospholamban phosphorylation status, were quantified in a mixed gender population of failing (n=14) and donor (n=15) myocardia. The apparent affinity (EC50) and the maximal velocity (Vmax) of SR Ca2+-uptake were also determined to lend functional significance to any observed protein alterations. Phospholamban and calsequestrin levels were not altered; however, SERCA protein levels were significantly reduced in failing hearts. Additionally, phospholamban phosphorylation (serine-16 and threonine-17 sites) and myocardial cAMP content were both attenuated. The alterations in SR protein levels were also accompanied by a decreased V(max)and an increased EC50 (diminished apparent affinity) of SR Ca2+-uptake for Ca2+ in failing myocardia. Myocardial protein levels and Ca2+ uptake parameters were then analyzed with respect to gender, which revealed that the decreases in phosphorylated serine-16 were specific to male failing hearts, reflecting increases in the EC50 values of SR Ca2+-uptake for Ca2+, compared to donor males. These findings suggest that although decreased SERCA protein and phospholamban phosphorylation levels contribute to depressed SR Ca2+-uptake and left ventricular function in heart failure, the specific subcellular alterations which underlie these effects may not be uniform with respect to gender.

The enhanced contractility of the phospholamban-deficient mouse heart persists with aging

J. P. Slack, I. L. Grupp, R. Dash, D. Holder, A. Schmidt, M. J. Gerst, T. Tamura, C. Tilgmann, P. F. James, R. Johnson, A. M. Gerdes and E. G. Kranias. The Enhanced Contractility of the Phospholamban-deficient Mouse Heart Persists with Aging. Journal of Molecular and Cellular Cardiology (2001) 33, 1031-1040. Phospholamban ablation in the mouse is associated with significant increases in cardiac contractility. To determine whether this hyperdynamic function persists through the aging process, a longitudinal examination of age-matched phospholamban-deficient and wild-type mice was employed. Kaplan-Meier survival curves indicated no significant differences between phospholamban-deficient and wild-type mice over the first year. Examination of cardiac function revealed significant increases in the rates of contraction (+dP/dt) and relaxation (-dP/dt) in phospholamban-deficient hearts compared with their wild-type counterparts at 3, 6, 12, 18 and 24 months of age. Quantitative immunoblotting indicated that the expression levels of the sarcoplasmic reticulum Ca(2+)-ATPase were not altered in wild-type hearts, while they were significantly decreased at 12 months (40%) and 18 months (20%) in phospholamban-deficient hearts. These findings on the persistence of hyperdynamic cardiac function over the long term suggest that phospholamban may constitute an important target for treatment in heart disease.

Malignancy in endometriosis: frequency and comparison of ovarian and extraovarian types

One thousand consecutive cases of surgically proven endometriosis were reviewed to evaluate the frequency and types of pelvic cancers that were associated with ovarian and extraovarian endometriosis. The frequency and types of histologic abnormalities present in the eutopic endometrium when cancers were noted in endometriosis were also evaluated. In the large subset of cases for which the authors were the primary pathologists and all foci of endometriosis were recorded, the frequency of malignancy was 10.8%. In contrast, the frequency was only 3.2% in cases diagnosed by others previously in our institution. Cancers were more commonly found in ovaries when endometriosis was present in that ovary (5%) compared to when endometriosis was present at other sites (1%). Clear cell and endometrioid carcinomas were the malignancies most commonly seen in ovaries containing endometriosis, while clear cell adenocarcinoma and adenosarcoma were most commonly seen in conjunction with extraovarian endometriosis. The association of endometriosis with endometrioid and clear cell carcinoma was much stronger than that of serous and mucinous tumors (p < .01). Concurrent endometrial pathology was commonly seen in cases of malignant transformation of endometriosis (32% of cases).

Interactions between phospholamban and beta-adrenergic drive may lead to cardiomyopathy and early mortality

BACKGROUND

Relieving the inhibition of sarcoplasmic reticular function by phospholamban is a major target of beta-adrenergic stimulation. Chronic beta-adrenergic receptor activity has been suggested to be detrimental, on the basis of transgenic overexpression of the receptor or its signaling effectors. However, it is not known whether physiological levels of sympathetic tone, in the absence of preexisting heart failure, are similarly detrimental.

METHODS AND RESULTS

Transgenic mice overexpressing phospholamban at 4-fold normal levels were generated, and at 3 months, they exhibited mildly depressed ventricular contractility without heart failure. As expected, transgenic cardiomyocyte mechanics and calcium kinetics were depressed, but isoproterenol reversed the inhibitory effects of phospholamban on these parameters. In vivo cardiac function was substantially depressed by propranolol administration, suggesting enhanced sympathetic tone. Indeed, plasma norepinephrine levels and the phosphorylation status of phospholamban were elevated, reflecting increased adrenergic drive in transgenic hearts. On aging, the chronic enhancement of adrenergic tone was associated with a desensitization of adenylyl cyclase (which intensified the inhibitory effects of phospholamban), the development of overt heart failure, and a premature mortality.

CONCLUSIONS

The unique interaction between phospholamban and increased adrenergic drive, elucidated herein, provides the first evidence that compensatory increases in catecholamine stimulation can, even in the absence of preexisting heart failure, be a primary causative factor in the development of cardiomyopathy and early mortality.

Provocative angiography in obscure gastrointestinal bleeding

Obscure gastrointestinal (GI) bleeding is relatively common but difficult to manage. By definition, diagnosis of a specific etiology is particularly challenging. We report the diagnostic use of provocative angiography in a patient with recurrent obscure GI bleeding. Although provocative angiography led to localization of bleeding and allowed specific treatment (placement of a 2-mm long, 0.010-inch diameter platinum coil, resulting in cessation of bleeding for 2 months), ultimately, the use of provocative angiography delayed specific diagnosis in our patient. We conclude that provocative angiography is a potentially powerful adjunct in the management of obscure GI bleeding, but that caution is required when using it. Provocative angiography should be reserved for patients who have had adequate imaging studies with negative results.

Altering the receptor-effector ratio by transgenic overexpression of type V adenylyl cyclase: enhanced basal catalytic activity and function without increased cardiomyocyte beta-adrenergic signalling

The limiting element in beta-adrenergic receptor (betaAR)-G(s)-adenylyl cyclase (AC) signal transduction in the cardiomyocyte is not known, but it has been proposed that the level of adenylyl cyclase expression constrains betaAR signaling. To alter the above equilibrium, type V AC was overexpressed in a myocyte-specific manner in the hearts of transgenic mice using the alpha-myosin heavy chain promoter. Expression of type V AC was approximately 75% over endogenous levels as quantitated by [(3)H]forskolin binding. Functional activity of the transgene product was evident in cardiac membrane AC studies, where basal (45 +/- 11 vs 19 +/- 5 pmol min(-)(1) mg(-)(1)) and forskolin+Mn(2+) (695 +/- 104 vs 386 +/- 34 pmol min(-)(1) mg(-)(1)) stimulated activities were increased compared to activities in nontransgenic (NTG) littermates. However, while isoproterenol stimulated activities were higher (74 +/- 12 vs 46 +/- 9.8 pmol min(-)(1) mg(-)(1)), the fold stimulation over basal was not increased in ACV overexpressors compared to NTG (line 14.3 = 2.29 +/- 0.44-fold, line 15.1 = 1.70 +/- 0.1-fold, NTG = 2.62 +/- 0.18-fold). Similarly, in whole cell patch-clamp studies, betaAR-mediated opening of L-type Ca(2+) channels was not found to be enhanced in transgenic ACV myocytes (225 +/- 15 vs 216 +/- 10% of basal currents). Basal and isoproterenol stimulated PKA activities were elevated in the ACV mice compared to NTG, but again the extent of stimulation over basal was not enhanced. Phosphorylated phospholamban was approximately 2-fold greater in myocytes from ACV hearts compared to NTG, indicating that distal elements of the contractile cascade are activated by AC overexpression. ACV mice displayed increased heart rates and fractional shortening as assessed by echocardiography. However, in vivo hemodynamic studies revealed that heart rate and contractility responses to agonist infusion were not enhanced in ACV mice compared to NTG. We conclude that at native stoichiometries, the levels of adenylyl cyclase influence basal activities and cardiac function, but do not constrain betaAR signaling in the cardiomyocyte.

Influence of transgenic overexpression of phospholamban on postextrasystolic potentiation

Twelve mice with PLB overexpression (PLBOE), and 11 isogenic FVB/N wild-type (WT) controls, were anesthetized and instrumented with a 1.4 F Millar catheter in the LV and a 1 F pacemaker in the right atrium. At a cycle length of 200 ms and a fixed extrastimulus of 120 ms, extrastimuli with increasing intervals (PESI) up to 1000 ms were introduced, and the peak rates of LV isovolumic contraction (+/- dP/dtmax) were normalized and fit to monoexponential equations. In a subset of animals, the protocols were repeated after ryanodine (4 ng/g) was given to deplete SR Ca2+ stores. The time constant and the plateau of the exponential curve fits were significantly greater in PLBOE than WT (107.8 +/- 7.0 v 75.2 +/- 5.5 ms and 1.39 +/- 0.03 v 1.08 +/- 0.02, both P < 0.05). At 200, 600 and 1000 ms, the normalized dP/dt was significantly greater in PLBOE than WT. After ryanodine, normalized dP/dt was significantly decreased in PLBOE, but unchanged in WT. The protein levels of the sodium-calcium exchanger normalized to calsequestrin were increased 3.7 +/- 0.3-fold in PLBOE compared to controls. In conclusion, the phospholamban level is a critical determinant of postextrasystolic potentiation in this transgenic model, and is differentially impaired by ryanodine at long diastolic intervals in PLBOE v controls. These differences may be due in part to changes in the protein level and resultant activity of the sodium calcium exchanger.

Astressin, a novel and potent CRF antagonist, is neuroprotective in the hippocampus when administered after a seizure

Corticotropin-releasing factor (CRF), the principle hypothalamic regulator of the adrenocortical axis, also functions as a neurotransmitter. In this latter role, CRF causes electrophysiological activation and epileptiform activity in various brain regions. That finding, coupled with the observation that CRF mRNA is induced in endangered brain regions following necrotic insults, suggests that the peptide might contribute to necrotic neuron loss. Supporting that, a number of studies have shown that CRF antagonists decrease ischemic or excitotoxic damage to neurons. In the present report, we demonstrate the considerable neuroprotective potential of a novel and potent CRF antagonist, astressin, against kainic acid-induced excitotoxic seizures. Intracerebroventricular infusion of the peptide both 30 min before and 10 min after seizures decreased damage in some hippocampal cell fields by as much as 84%, a magnitude of protection greater than reported for other CRF antagonists against other models of necrotic neuronal injury. Administration of astressin was done against both local microinfusion (0.035 microgram) or systemic infusion (10 mg/kg body weight) of the excitotoxin; furthermore, the peptide protected even if administered only 10 min following excitotoxin exposure. This fulfills a critical prerequisite for any eventual therapeutic use of CRF antagonists, namely that they need not be administered in anticipation of a neurological insult.

Overexpression of the glucose transporter gene with a herpes simplex viral vector protects striatal neurons against stroke

Herpes simplex virus vectors bearing a glucose transporter (GT) gene and a marker gene were found to protect neurons against a 1-h focal ischemic insult. Rats receiving the GT vector v alpha22beta gal alpha4GT exhibited a 67.4 +/- 35.3% survival of virally targeted neurons in the ischemic hemisphere compared with the contralateral control (n = 7), whereas rats receiving a control vector exhibited only 32.8 +/- 17.9% survival (n = 9). This significant improvement in survival (105%, p=0.022) suggests that energy failure is an important contributor to the neuropathology of ischemic damage in the striatum, and that it can be alleviated by gene transfer. This is the first demonstration of protection against ischemic cerebral injury by the direct transfer of GT genes to neurons.

A herpes simplex virus vector overexpressing the glucose transporter gene protects the rat dentate gyrus from an antimetabolite toxin

The use of herpes simplex virus vectors offers an attractive means for the in vitro and in vivo transfer of novel genes into postmitotic neurons. Such an approach allows for the introduction of genes with the potential to protect neurons from necrotic insults. Toward that end, we have previously constructed a bicistronic herpes viral vector expressing the gene for the Glut-1 rat brain glucose transporter (GT), along with the Escherichia coli lacZ reporter gene. We observed that this vector enhances glucose uptake both in primary hippocampal cultures and in the hippocampus itself. Moreover, we have found that this vector will protect a variety of types of cultured neurons from necrotic insults and protect hippocampal neurons in vivo from seizure-induced damage. In the present report, we further demonstrate the neuroprotective potential of this GT-expressing vector. 3-Acetylpyridine, an electron transport uncoupler which is preferentially toxic to the dentate gyrus, was microinfused into the dorsal hippocampus of rats. Infection of dentate neurons with GT vectors at the time of exposure to the toxin significantly decreased damage, whereas infection with a physiologically neutral control vector did not. Moreover, there was a window of opportunity for this intervention, as microinfusion of the GT-expressing vector up to 1 h, but not 4 h, after the insult was still neuroprotective.

Continuity and discontinuity in the anti-V3 IgG response of human immunodeficiency virus type 1-infected persons in a cross-sectional and longitudinal study using synthetic peptides

The principal neutralization domain (PND) of the V3 region of human immunodeficiency virus type 1 (HIV-1) gp120 is central to HIV pathogenesis. The IgG antibody response to PND was followed in 15 HIV-1-infected persons from southern Sweden over 2-5 years using 32 synthetic V3 peptides. Five peptides had amino acid sequences derived from isolates from each of 5 patients. Sera obtained simultaneously with isolate almost always reacted strongly with these cognate peptides; however, reactivity was undetectable in 1 patient's serum and short lived in the sera of another, indicating inducible holes in the antibody repertoire, which would facilitate dissemination of the corresponding virus strains. Reactivity to other V3 peptides correlated with sequence similarity to the cognate peptide. Strong, stable reactivity to peptides with sequences similar to a south Swedish V3-consensus was accompanied by transient activity to less similar ones. The latter may reflect viral variation, B lymphocyte clonal depletion, or both. Certain IgG responses appeared to preclude others, suggesting clonal dominance.

Herpes simplex virus vectors overexpressing the glucose transporter gene protect against seizure-induced neuron loss

We have generated herpes simplex virus (HSV) vectors vIE1GT and v alpha 4GT bearing the GLUT-1 isoform of the rat brain glucose transporter (GT) under the control of the human cytomegalovirus ie1 and HSV alpha 4 promoters, respectively. We previously reported that such vectors enhance glucose uptake in hippocampal cultures and the hippocampus. In this study we demonstrate that such vectors can maintain neuronal metabolism and reduce the extent of neuron loss in cultures after a period of hypoglycemia. Microinfusion of GT vectors into the rat hippocampus also reduces kainic acid-induced seizure damage in the CA3 cell field. Furthermore, delivery of the vector even after onset of the seizure is protective, suggesting that HSV-mediated gene transfer for neuroprotection need not be carried out in anticipation of neurologic crises. Using the bicistronic vector v alpha 22 beta gal alpha 4GT, which coexpresses both GT and the Escherichia coli lacZ marker gene, we further demonstrate an inverse correlation between the extent of vector expression in the dentate and the amount of CA3 damage resulting from the simultaneous delivery of kainic acid.

Herpes simplex virus vector system: analysis of its in vivo and in vitro cytopathic effects

With its natural propensity to infect and establish life-long latency in neurons, herpes simplex virus type 1 (HSV-1) has been successfully employed by various laboratories as vectors for gene transfer into neurons. However, analysis of its cytopathic effects in vivo and in vitro has been limited. In this study, we examined the cytopathic effects of 2 HSV-1 alpha 4 mutants (ts756 and d120) on adult rat hippocampus and striatum and of d120 on hippocampal neurons in culture. We assessed damage by stringent counting of surviving neurons after infection and demonstrated that while neither ts756 nor d120 infection resulted in any gross anatomical or behavioral changes of the animals, ts756, but not d120, produced a significant amount of damage in the CA4 cell field and dentate gyrus of the hippocampus. Thus, since crude examination is insufficient to detect subtle but significant degrees of neuron loss, the cytopathic effects of HSV or any vector system must be carefully analyzed. Furthermore, we also observed that uninfected cell lysates damaged neurons, both in vivo and in vitro. This cytotoxicity occurred within the first 24 h post-inoculation and probably arose through the activation of glutamate receptors. For the preparation of HSV vectors, purification of the virus from soluble cellular components by a simple pelleting step can significantly decrease such acute toxicity.

A survey of synthetic HIV-1 peptides with natural and chimeric sequences for differential reactivity with Zimbabwean, Tanzanian and Swedish HIV-1-positive sera

OBJECTIVE

To determine whether the known sequence differences between African and non-African HIV-1 strains are reflected in the serological response.

DESIGN AND METHODS

We investigated the antibody reactivity of 34 Swedish, 30 Tanzanian and 42 Zimbabwean HIV-1-positive sera to 67 synthetic peptides with sequences from North American and African HIV-1 isolates, mostly derived from regions of gag and env known to be antigenic. Not all sera were tested against all peptides.

RESULTS

Differences in frequency of reactivity were noted with peptides covering the entire third variable domain (V3), which is a primary neutralization determinant, and the carboxyl terminus of gp120, in two regions of gp41, and the carboxyl terminus of p24. In env Tanzanian sera reacted preferentially with a V3 peptide from the strain JY1 (Zaire). Gradual substitutions in the central motif in V3 of ELI from GLGQ to GPGR, typical of many non-African strains, led to a gradual increase in reactivity of many Swedish sera, but did not affect Tanzanian and Zimbabwean sera, suggesting that the major epitopes recognized by these African sera are outside GPGR. V3 peptides from the MN and Z3 strains reacted with most sera, but missed 30% of those of Tanzanian origin. In the carboxyl terminus of gp120 both sets of African sera reacted preferentially with peptides from strains JY1 and MAL. Swedish sera reacted strongest with analogues from strains Z321 and HXB2. In gp41, Swedish sera showed a weak preference for reactivity with HXB2-derived peptides in the immunodominant region (amino acids 590-620), and further towards the carboxyl terminus (amino acids 620-665).

CONCLUSION

The differences in serological reactivity were as great between Zimbabwe and Tanzania as between the two African sets and the Swedish. The geographical differences in the pattern of reactivity with HIV peptides probably depend on both host and viral variation and may be developed into a seroepidemiological tool, useful for optimization of future HIV vaccines.

Serum and pancreatic immunoreactive insulin (IRI) and proinsulin-like component (PLC), serum IRI and PLC response to different stimuli in normal subjects and organic hyperinsulinism

The serum levels of total immunoreactive insulin (IRI) and proinsulin-like component (PLC) in the fasting state and following the administration of insulin secretagogues in 5 patients with organic hyperinsulinism and age and sex matched normal subjects are reported. Diagnosis of organic hyperinsulinism could be established in all instances on the basis of the inappropriately high total serum IRI levels for the corresponding blood glucose values; such an abnormal relationship was not seen in normal subjects, and was further enhanced by insulin secretagogues. Unrestrained insulin secretion in organic hyperinsulinism was enhanced following the administration of glucose, tolbutamide, glucagon or amino acids; the last 2 stimuli are known to be ineffective in causing insulin secretion in the presence of hypoglycemia in normal subjects. Four patints had insulinomas and one probably had islet cell hyperplasia or abnormal function of islet cells. Chromatography of serum IRI to quantitate PLC is a useful adjunct to the diagnosis of organic hyperinsulinism as in the fasting state the proportion of PLC is always elevated, above the normal range of 5-22%. Following the administration of insulin secretagogues there was pronounced increase in total serum IRI in organic hyperinsulinism but the proportion of PLC generally decreased, suggesting thereby that mojor increase in IRI was due to release of stored granular IRI which is known to have a low proportion of PLC.