Design and selection of anti-PD-L1 single-domain antibody and tumor necrosis factor superfamily ligands for an optimal vectorization in an oncolytic virus

Arming oncolytic viruses with transgenes encoding immunomodulators improves their therapeutic efficacy by enhancing and/or sustaining the innate and adaptive anti-tumoral immune responses. We report here the isolation, selection, and vectorization of a blocking anti-human PDL1 single-domain antibody (sdAb) isolated from PDL1-immunized alpacas. Several formats of this sdAb were vectorized into the vaccinia virus (VV) and evaluated for their programmed cell death protein 1 (PD1)/PD1 ligand (PDL1) blocking activity in the culture medium of tumor cells infected in vitro. In those conditions, VV-encoded homodimeric sdAb generated superior PDL1 blocking activity compared to a benchmark virus encoding full-length avelumab. The sdAb was further used to design simple, secreted, and small tumor necrosis factor superfamily (TNFSF) fusions with the ability to engage their cognate receptors (TNFRSF) only in the presence of PDL1-positive cells. Finally, PDL1-independent alternatives of TNFRSF agonists were also constructed by fusing different variants of surfactant protein-D (SP-D) oligomerization domains with TNFSF ectodomains. An optimal SP-D-CD40L fusion with an SP-D collagen domain reduced by 80% was identified by screening with a transfection/infection method where poxvirus transfer plasmids and vaccinia virus were successively introduced into the same cell. However, once vectorized in VV, this construct had a much lower CD40 agonist activity compared to the SP-D-CD40L construct, which is completely devoid of the collagen domain that was finally selected. This latest result highlights the importance of working with recombinant viruses early in the payload selection process. Altogether, these results bring several complementary solutions to arm oncolytic vectors with powerful immunomodulators to improve their immune-based anti-tumoral activity.

Vectorization in an oncolytic vaccinia virus of an antibody, a Fab and a scFv against programmed cell death -1 (PD-1) allows their intratumoral delivery and an improved tumor-growth inhibition

We report here the successful vectorization of a hamster monoclonal IgG (namely J43) recognizing the murine Programmed cell death-1 (mPD-1) in Western Reserve (WR) oncolytic vaccinia virus. Three forms of mPD-1 binders have been inserted into the virus: whole antibody (mAb), Fragment antigen-binding (Fab) or single-chain variable fragment (scFv). MAb, Fab and scFv were produced and assembled with the expected patterns in supernatants of cells infected by the recombinant viruses. The three purified mPD-1 binders were able to block the binding of mPD-1 ligand to mPD-1 in vitro. Moreover, mAb was detected in tumor and in serum of C57BL/6 mice when the recombinant WR-mAb was injected intratumorally (IT) in B16F10 and MCA 205 tumors. The concentration of circulating mAb detected after IT injection was up to 1,900-fold higher than the level obtained after a subcutaneous (SC) injection (i.e., without tumor) confirming the virus tropism for tumoral cells and/or microenvironment. Moreover, the overall tumoral accumulation of the mAb was higher and lasted longer after IT injection of WR-mAb1, than after IT administration of 10 µg of J43. The IT injection of viruses induced a massive infiltration of immune cells including activated lymphocytes (CD8⁺ and CD4⁺). Interestingly, in the MCA 205 tumor model, WR-mAb1 and WR-scFv induced a therapeutic control of tumor growth similar to unarmed WR combined to systemically administered J43 and superior to that obtained with an unarmed WR. These results pave the way for next generation of oncolytic vaccinia armed with immunomodulatory therapeutic proteins such as mAbs.

Abstract 2352: Vectorization in an oncolytic vaccinia virus of an antibody, a Fab and a scFv against programmed cell death -1 (PD-1) allow their intratumoral delivery and an improved tumor-growth inhibition

We report here the successful vectorization of a hamster monoclonal IgG (namely J43) recognizing the murine Programmed cell death-1 (mPD-1) in Western Reserve (WR) oncolytic vaccinia virus. Three forms of mPD-1 binders have been inserted in the virus: whole antibody (mAb), Fragment antigen-binding (Fab) or single-chain variable fragment (scFv). MAb, Fab and scFv were produced and assembled with the expected patterns in supernatants of cells infected by the recombinant viruses. The 3 purified mPD-1 binders were able to block the binding of mPD-1 ligand to mPD-1 in vitro. Moreover, mAb was detected in tumor and in serum of C57BL/6 mice when the recombinant WR-mAb was injected intratumorally (IT) in B16F10 and MCA 205 tumors. The concentration of circulating mAb detected after IT injection was up to 1900-fold higher than the level obtained after a subcutaneous (SC) injection (i.e. without tumor) confirming the virus tropism for tumoral cells and/or that tumoral microenvironment allows virus escape from immune surveillance. Moreover, the overall tumoral accumulation of the mAb was higher and lasted longer after IT injection of WR-mPD-1, than after IT administration of 10 μg of J43. Interestingly, in the MCA 205 tumor model, WR-mPD-1 (both mAb and scFv) induced a therapeutic control of tumor growth similar to unarmed WR combined to systemically administered J43 and superior to that provided by an unarmed WR. These results pave the way for next generation of oncolytic vaccinia armed with immunomodulatory therapeutic proteins such as mAbs. New generation of oncolytic vaccinia virus that will express several transgenes simultaneously may also be designed with the goal of providing to the patients enhanced therapeutic/toxicity ratio.

Citation Format: Jean-Baptiste Marchand, Patricia Kleinpeter, Laetitia Fend, Christine Thioudellet, Michel Geist, Nathalie Sfrontato, Véronique Koerper, Renée Brandely, Dominique Villeval, Karola Rittner, Nathalie Silvestre, Philippe Erbs, Laurence Zitvogel, Eric Quemeneur, Xavier Preville. Vectorization in an oncolytic vaccinia virus of an antibody, a Fab and a scFv against programmed cell death -1 (PD-1) allow their intratumoral delivery and an improved tumor-growth inhibition. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 2352.

TG1050, an immunotherapeutic to treat chronic hepatitis B, induces robust T cells and exerts an antiviral effect in HBV-persistent mice

OBJECTIVE

To assess a new adenovirus-based immunotherapy as a novel treatment approach to chronic hepatitis B (CHB).

METHODS

TG1050 is a non-replicative adenovirus serotype 5 encoding a unique large fusion protein composed of a truncated HBV Core, a modified HBV Polymerase and two HBV Envelope domains. We used a recently described HBV-persistent mouse model based on a recombinant adenovirus-associated virus encoding an over length genome of HBV that induces the chronic production of HBsAg, HBeAg and infectious HBV particles to assess the ability of TG1050 to induce functional T cells in face of a chronic status.

RESULTS

In in vitro studies, TG1050 was shown to express the expected large polyprotein together with a dominant, smaller by-product. Following a single administration in mice, TG1050 induced robust, multispecific and long-lasting HBV-specific T cells detectable up to 1 year post-injection. These cells target all three encoded immunogens and display bifunctionality (i.e., capacity to produce both interferon γ and tumour necrosis factor α as well as cytolytic functions). In addition, control of circulating levels of HBV DNA and HBsAg was observed while alanine aminotransferase levels remain in the normal range.

CONCLUSIONS

Injection of TG1050 induced both splenic and intrahepatic functional T cells producing cytokines and displaying cytolytic activity in HBV-naïve and HBV-persistent mouse models together with significant reduction of circulating viral parameters. These results warrant clinical evaluation of TG1050 in the treatment of CHB.

3D modeling and characterization of the human CD115 monoclonal antibody H27K15 epitope and design of a chimeric CD115 target

The humanized monoclonal antibody H27K15 specifically targets human CD115, a type III tyrosine kinase receptor involved in multiple cancers and inflammatory diseases. Binding of H27K15 to hCD115 expressing cells inhibits the functional effect of colony-stimulating factor-1 (CSF-1), in a non-competitive manner. Both homology modeling and docking programs were used here to model the human CD115 extracellular domains, the H27K15 variable region and their interaction. The resulting predicted H27K15 epitope includes mainly the D1 domain in the N-terminal extracellular region of CD115 and some residues of the D2 domain. Sequence alignment with the non-binding murine CD115, enzyme-linked immunosorbent assay, nuclear magnetic resonance spectroscopy and affinity measurements by quartz crystal microbalance revealed critical residues of this epitope that are essential for H27K15 binding. A combination of computational simulations and biochemical experiments led to the design of a chimeric CD115 carrying the human epitope of H27K15 in a murine CD115 backbone that is able to bind both H27K15 as well as the murine ligands CSF-1 and IL-34. These results provide new possibilities to minutely study the functional effects of H27K15 in a transgenic mouse that would express this chimeric molecule.

A unique anti-CD115 monoclonal antibody which inhibits osteolysis and skews human monocyte differentiation from M2-polarized macrophages toward dendritic cells

Cancer progression has been associated with the presence of tumor-associated M2-macrophages (M2-TAMs) able to inhibit anti-tumor immune responses. It is also often associated with metastasis-induced bone destruction mediated by osteoclasts. Both cell types are controlled by the CD115 (CSF-1R)/colony-stimulating factor-1 (CSF-1, M-CSF) pathway, making CD115 a promising target for cancer therapy. Anti-human CD115 monoclonal antibodies (mAbs) that inhibit the receptor function have been generated in a number of laboratories. These mAbs compete with CSF-1 binding to CD115, dramatically affecting monocyte survival and preventing osteoclast and macrophage differentiation, but they also block CD115/CSF-1 internalization and degradation, which could lead to potent rebound CSF-1 effects in patients after mAb treatment has ended. We thus generated and selected a non-ligand competitive anti-CD115 mAb that exerts only partial inhibitory effects on CD115 signaling without blocking the internalization or the degradation of the CD115/CSF-1 complex. This mAb, H27K15, affects monocyte survival only minimally, but downregulates osteoclast differentiation and activity. Importantly, it inhibits monocyte differentiation to CD163⁺CD64⁺ M2-polarized suppressor macrophages, skewing their differentiation toward CD14^-CD1a⁺ dendritic cells (DCs). In line with this observation, H27K15 also drastically inhibits monocyte chemotactic protein-1 secretion and reduces interleukin-6 production; these two molecules are known to be involved in M2-macrophage recruitment. Thus, the non-depleting mAb H27K15 is a promising anti-tumor candidate, able to inhibit osteoclast differentiation, likely decreasing metastasis-induced osteolysis, and able to prevent M2 polarization of TAMs while inducing DCs, hence contributing to the creation of more efficient anti-tumor immune responses.

Kalman Temporal Differences

Because reinforcement learning suffers from a lack of scalability, online value (and Q-) function approximation has received increasing interest this last decade. This contribution introduces a novel approximation scheme, namely the Kalman Temporal Differences (KTD) framework, that exhibits the following features: sample-efficiency, non-linear approximation, non-stationarity handling and uncertainty management. A first KTD-based algorithm is provided for deterministic Markov Decision Processes (MDP) which produces biased estimates in the case of stochastic transitions. Than the eXtended KTD framework (XKTD), solving stochastic MDP, is described. Convergence is analyzed for special cases for both deterministic and stochastic transitions. Related algorithms are experimented on classical benchmarks. They compare favorably to the state of the art while exhibiting the announced features.

Specific tumor cell targeting by a recombinant MVA expressing a functional single chain antibody on the surface of intracellular mature virus (IMV) particles

Recombinant vaccinia virus with tumor cell specificity may provide a versatile tool either for direct lysis of cancer cells or for the targeted transfer of genes encoding immunomodulatory or toxic molecules. We report the expression of a tumor-specific single-chain antibody on the surface of intracellular mature vaccinia virus particles (IMV). The wild-type p14 externally membrane-associated protein p14 (A27L gene), which is not required for viral binding and replication, was replaced by p14 fusion molecules carrying a single-chain antibody directed against the tumor-associated antigen MUC-1. MUC-1 mucin is an epithelial cell antigen whose aberrant expression plays a role in autoimmunity and tumor immunity in the majority of human carcinomas and multiple myeloma. Fusion protein carrying the single-chain antibody at the NH2-terminal position was expressed and exposed at the envelope of the corresponding recombinant virus. The construct containing the antibody was able to bind a MUC-1 specific 60mer peptide. Moreover, targeted virus infects MUC-1-expressing cells in vitro more efficiently.

Tumor gene therapy by MVA-mediated expression of T-cell-stimulating antibodies

Immune responses to tumor-associated antigens are often dampened by a tumor-induced state of immune anergy. Previous work has attempted to overcome tumor-induced T-cell anergy by the direct injection of vectors carrying the genes encoding one of a variety of cytokines. We hypothesised that the polyclonal stimulation of T cells, preferably through the TCR complex, would result in a cascade of cytokines associated with T-cell activation and would be best able to overcome T-cell anergy. Here we use the highly attenuated MVA poxvirus to express on tumor cells, in vitro and in vivo, either of three membrane-bound monoclonal antibodies specific for murine TCR complex. Using this system, we have expressed antibodies specific for the CD3 epsilon chain (KT3), TCR alpha/beta complex (H57-597), and V beta 7 chain (TR310). Tumor cells bristling with these antibodies are capable of inducing murine T-cell proliferation and cytokine production. When injected into growing tumors (P815, RenCa, and B16F10), these constructs induce the activation of immune effector cells and result in the rejection of the tumor. Histological and FACS analysis of tumor-infiltrating leukocytes reveal that the injection of recombinant virus-expressing antibodies specific for the TCR complex attracts and activates (CD25(+), CD69(+)) CD4 and CD8 lymphocytes. This approach represents a novel strategy to overcome T-cell anergy in tumors and allow the stimulation of tumor-specific T cells.

Where do adolescents get their condoms?

PURPOSE

To determine where adolescents obtain their condoms; the availability and accessibility of condoms; condom availability in relationship to different sexually transmitted disease (STD) rates; and the availability of safer sex information in places where condoms are sold.

METHODS

We conducted a random digit-dialed telephone survey of 259 14-19-year-old adolescents in Monroe County, New York. Self-reported health services use, knowledge and use of confidential services, and where adolescents obtained or intended to obtain condoms were assessed. Research assistants visited all retail establishments in five areas of similar population size with gonorrhea rates from 887 to 12,427 per 100,000 adolescents to assess how available and accessible condoms were in each store. Perceived access and actual condom availability and accessibility were compared using Chi-square and Student's t-tests.

RESULTS

Trained interviewers dialed 11,800 numbers in 1993, identifying 4449 (40%) households among 11,065 numbers reached successfully. Of these, 393 (8.8%) had eligible adolescents and 259 (66%) completed interviews. Most adolescents reported obtaining, or planning to obtain, condoms in stores rather than from free health care settings. Adolescents who have used condoms more often reported having obtained them without cost than having purchased them. Condoms were available at 101 (83%) of 122 stores identified. All drug stores and 75% of supermarkets sold condoms and displayed them openly. Most small grocery stores also sold condoms (92%), but were less likely to openly display them. No stores displayed or provided safer sex information. Areas with higher STD rates had more stores (p <.01), and more stores that sold condoms (p <.01). There was no difference in condom cost by area.

CONCLUSIONS

Many adolescents obtain their condoms in retail stores. Condom accessibility varied by store type and area STD rate. Increasing condom visibility in private grocery stores may increase the accessibility of condoms to adolescents in areas with highest STD rates.

Effects of rhythm regularization and rate control in improving left ventricular function in atrial fibrillation patients undergoing atrioventricular nodal ablation

OBJECTIVES

To assess the relative contributions of rate control and rhythm regularization to left ventricular function in atrial fibrillation (AF) patients undergoing atrioventricular nodal ablation. This was performed by assessing the effect of ventricular rhythm regularization on left ventricular function during AF, and the effect of varying heart rate on left ventricular function after ablation.

PATIENTS AND METHODS

Eleven patients with continuous AF and V/VI-R pacemakers undergoing therapeutic atrioventricular nodal ablation were studied. Preablation patients underwent two 30 min observation periods in a randomized, blinded fashion during which they were either in baseline AF (pacer set to default V/VI 50/min) or being paced using a rhythm stabilizing algorithm (RSA) designed to regularize rhythm without changing baseline ventricular rate. Six weeks after ablation, patients were again observed during the two following 30 min periods: pacing at a low clinically indicated rate (69+/-9 beats/min), and pacing at the rapid, mean preablation rate. During all observation periods, left ventricular function was measured continuously using a nuclear vest that provided validated measures of heart rate, ejection fraction, and normalized end-systolic volume (ESV) and end-diastolic (EDV) volume.

RESULTS

Before ablation, RSA successfully regularized rhythm, decreasing the coefficient of variation of interbeat intervals 20+/-5% to 10+/-4% (P<0.001). The heart rate with RSA (105+/-19 beats/min) was not significantly different from the baseline AF rate (102+/-21 beats/min). Increased rhythm regularity achieved by RSA significantly improved left ventricular function, decreasing ESV from 62+/-12 units to 57+/-11 units (P=0.03), and increasing the ejection fraction from 31+/-11% to 36+/-11% (P=0.03). After ablation, at the clinically indicated low pacing rate of 69+/-9 beats/min, a much greater improvement in ejection fraction was observed, increasing to 44+/-13% (P=0.005 compared with preablation). However, rapid regular pacing at the mean preablation rate of 110+/-18 beats/min eradicated this improvement, decreasing the ejection fraction to 31+/-8% (P=0.003), and increasing ESV from 53+/-13 units to 62+/-8 units (P=0.006).

CONCLUSIONS

Rhythm regularity achieved by a regularizing pacing algorithm can significantly, albeit modestly, improve left ventricular function in AF. However, more marked improvements in left ventricular function seen after ablation are primarily due to rate reduction alone.

Permanent explantation of implantable cardioverter defibrillators

Although ICD therapy is seen as an irrevocable mode of therapy in most patients, a small number of patients do have their devices permanently explanted. The long-term outcome in these patients has not been described. The purpose of this single center study was to evaluate the long-term outcome of patients whose ICD was explanted and not replaced and to propose clinical variables that can be considered when making the decision to discontinue therapy. Ten of 323 (3.1%) patients in our ICD registry had their devices permanently explanted or turned off between 1986 and December 1998. The devices had been in place for 39 +/- 31 months preexplant. No patient had received appropriate therapy prior to surgery, which was indicated for infection or lead fracture. All patients are alive and well 75 +/- 30 months postexplant with 1 (10%) patient requiring late reimplantation. We reviewed the English language literature describing ICD explanation without replacement. A total of 151 patients were reported in eight studies and were followed for up to 30 months postexplant. Excluding patients with terminal illness or heart transplantation 57.6% survived without reimplantation. In selected patients, after not using an ICD for a long period and when clinical circumstances justify, device therapy may be discontinued with some degree of safety.

Transvenous pacemaker leads do not worsen tricuspid regurgitation: a prospective echocardiographic study

Limited prospective data are available regarding the influence of pacemaker leads on tricuspid valve function. To examine the true incidence of these complications, 35 patients were prospectively examined by two-dimensional and Doppler echocardiography before and after implantation of either a permanent pacemaker or an automatic implantable cardioverter-defibrillator. Of the 35 patients imaged preoperatively, the amount of tricuspid regurgitation (TR) was judged as normal or trivial in 15 (43%), mild in 10 (29%), moderate in 8 (23%), and severe in 2 (6%). Following electrode implantation, TR was noted to be normal or trivial in 13 (38%), mild in 15 (48%), moderate in 6 (17%) and severe in 1 (3%). We conclude that implantation of permanent right ventricular electrodes is not usually associated with an acute worsening of tricuspid regurgitation in most patients.

Enveloped virus is the major virus form produced during productive infection with the modified vaccinia virus Ankara strain

Modified vaccinia virus Ankara (MVA) is a highly attenuated virus strain that may be useful as a vaccine vector. Ultrastructural examination of purified MVA showed that most of the viral particles are enveloped in contrast to the Copenhagen strain (COP). In CsCl gradients, the majority of the MVA particles displayed a light buoyant density characteristic of the enveloped form. Consistent with these results, MVA particles were poorly labeled with antibodies against the surface of intracellular mature virus but strongly labeled with antibodies against an envelope antigen. Furthermore, MVA was more resistant than the COP strain to neutralization by mouse anti-COP antibodies. These results suggest that the MVA strain may be particularly suitable for the engineering of envelope proteins and that MVA may be able to resist the humoral immunity displayed by previously vaccinated individuals.

Is electrical storm in ICD patients the sign of a dying heart? Outcome of patients with clusters of ventricular tachyarrhythmias

BACKGROUND

Electrical storm in patients with implanted cardioverter defibrillators (ICDs) is purported to carry an ominous prognosis.

METHODS AND RESULTS

We retrospectively compared 40 patients with electrical storm (defined as three or more episodes of ventricular arrhythmia requiring ICD therapy in a 24 h period) with those only having isolated appropriate ICD therapy (n=57) and with patients having no or only inappropriate ICD therapy (n=125). All patients received ICDs for documented sustained VT or VF. There was no significant difference in age, sex, ejection fraction, total follow-up time, or underlying heart disease between any of the three groups. Patients who had electrical storm received their first appropriate ICD therapy 275 +/- 369 days post-implant (35% had storm as their first event) with storm occurring an average of 599 +/- 710 days post-implant. Patients had 1.5 +/- 1.0 storms in total (median= 1), with 55 +/- 91 episodes per storm. There were no significant differences in actuarial survival at 5-year follow-up between the three groups. Eighty percent of storm patients were alive 5 years post-implant.

CONCLUSION

Storm is a common occurrence in ICD patients, can occur at any time during the follow-up period, and does not independently confer increased mortality.

Targeted macrophage cytotoxicity using a nonreplicative live vector expressing a tumor-specific single-chain variable region fragment

Antigen-specific recognition and subsequent destruction of tumor cells is the goal of vaccine-based immunotherapy of cancer. Often, however, tumor antigen-specific cytotoxic T lymphocytes (CTLs) are either not available or in a state of anergy. In addition, MHCI expression on tumor cells is often downregulated. Either or both of these situations can allow tumor growth to proceed unchecked by CTL control. We have shown previously that tumor antigen-specific monoclonal antibodies can be expressed in vaccinia virus and that activated macrophages infected with this virus acquire the ability to kill tumor cells expressing that antigen. Here we show that a membrane-anchored form of the scFv portion of the MUC1 tumor antigen-specific monoclonal antibody, SM3, can be expressed on activated macrophages with the highly attenuated poxvirus, modified vaccinia Ankara (MVA), as a gene transfer vector. Cells infected with the MVA-scFv construct were shown to express the membrane-bound scFv by Western blot and FACS analysis. That cells expressing the membrane-anchored scFv specifically bind antigen was shown by FACS and by BIAcore analysis. GM-CSF-activated macrophages were infected with the construct and shown to recognize specifically MUC1-expressing tumor cells as measured by IL-12 release. Furthermore, activated macrophages expressing the membrane-bound scFv specifically lyse target cells expressing the MUC1 antigen but not cells that do not express MUC1.

Validation of a noninvasive measure of local myocardial repolarization in a conscious human model: adaptation of repolarization to changes in rate

INTRODUCTION

A commercial pacemaker sensor measure of the unipolar endocardial stimulus to T wave interval may accurately reflect changes in the monophasic action potential duration at 90% repolarization (APD90). This sensor system was used to study the kinetics of adaptation of repolarization duration to changes in heart rate in humans.

METHODS AND RESULTS

Patients were studied using an external pacemaker capable of displaying all stimulus to T wave intervals for each paced beat. Right ventricular stimulation was delivered via the pacemaker and compared simultaneously to APD90. Steady-state pacing was simulated by 60 seconds of pacing at cycle lengths (CLs) 350 to 700 msec. Adaptation to a new ventricular rate was analyzed with a sudden 200-msec decrease in CL. The relation between repolarization measure and steady-state CL (n = 16) was linear with a slope of 0.16 and 0.19 for APD90 and stimulus to T wave interval, respectively (P = NS). The adaptation of both repolarization measures to a sudden change in rate were best modeled by a biexponential function. Stimulus to T wave interval exhibited a parallel course to APD90, and an analysis of normalized differences between APD90 and stimulus to T wave interval followed an approximately normal distribution, with 93.5% of the paired differences within 2 SD of the mean.

CONCLUSION

A pacemaker sensor measure of stimulus to T wave interval accurately parallels APD90 during both steady-state and sudden changes in rate. Repolarization in human endocardium follows a linear relation to steady-state CL and adapts to a new rate with a biexponential function. This model represents a novel method for studying human cardiac repolarization.

Hyperaldosteronism and sudden cardiac death

From a database of 130 implantable cardiac defibrillator recipients, 2 patients (1.5%) with sudden cardiac death as a presenting symptom, leading to diagnosis of primary hyperaldosteronism, are described. This is a newly described cause of sudden cardiac death, possibly more frequent than suspected, which should be considered in patients with malignant arrhythmias and hypokalemia.

Mechanisms of cardiopulmonary resuscitation in a patient with right ventricular dilatation--an echocardiographic contribution

The mechanism of cardiopulmonary resuscitation is still debated. Two different theories have been proposed: direct cardiac compression versus intrathoracic pressure. A patient with dilated right cardiac chambers, who underwent a transesophageal echocardiography study during cardiopulmonary resuscitation, is reported. The direct compression mechanism was clearly demonstrated.

One-stage coronary angiography and angioplasty

The combination of diagnostic angiography and angioplasty as a single procedure is becoming common practice in many institutions, but the feasibility and safety of this strategy have not been reported. This report describes 2,069 patients who underwent coronary angioplasty over a 3-year period at an institution where combined angiography and angioplasty is the norm. All patients were prepared before angiography for potential immediate angioplasty. In 1,719 patients, angioplasty was performed immediately after the diagnostic angiogram, while separate procedures were performed in 350 patients. Of those 350 patients, 254 were referred for angioplasty after diagnostic angiography at other hospitals. One thousand one hundred ninety-seven patients were admitted electively for treatment of stable angina pectoris, and 872 underwent procedures during hospitalization for unstable angina or acute myocardial infarction. One thousand nine hundred seven patients (92.2%) had successful angioplasties; in 130 patients (6.3%) the lesion could not be dilated, but no complication occurred, and in 32 patients (1.5%) angioplasty ended with a major complication (0.8% death, 1.0% Q-wave myocardial infarction, 0.5% emergency coronary artery bypass surgery). There was no difference between the combined and staged groups with regard to success, major and minor complication rates or in length of hospitalization after angioplasty. We conclude that routine combined strategy for angiography and angioplasty is feasible, safe, easier for the patient, and more cost-effective than 2 separate procedures.

Coronary artery-pulmonary artery fistula associated with hypertrophic cardiomyopathy

This report describes two patients with the combination of a coronary artery fistula from the left anterior descending artery (LAD) to the pulmonary artery together with hypertrophic cardiomyopathy.

[The safety belt: effects on injury patterns of automobile passengers]

Since 1984 the law concerning safety belts has been implemented; this paper deals with the findings in 386 victims of motor accidents who were x-rayed between 1981 and 1989. Minor injuries have been ignored. The number of passengers wearing belts increased by 30% after 1984. The number of passenger injuries did not decrease. Injuries directly caused by the belts included a small number of fractures of clavicles, the sternum and ribs and one pelvic fracture, one serious abdominal injury with tearing of the mesenteric artery and one ruptured spleen. An indirect result of wearing seat belts was a marked increase in cervical whiplash injuries and some increase in thoracic vertebral fractures. None of the belt induced injuries proved fatal. Amongst those using seat belts there was a significantly lower fatality rate and injuries causing prolonged disability. In particular, using seat belts, serious injuries to the skull and brain were reduced by 80%. Similarly injuries to the abdomen, the odontoid, pelvis and hip joint were greatly reduced. The advantages of wearing a seat belt greatly outweigh the disadvantages.

Cardiac rupture during coronary angioplasty

Cardiac rupture is a catastrophic complication of acute myocardial infarction. We describe a patient with acute myocardial infarction who received thrombolytic therapy and then developed cardiac rupture and tamponade during rescue angioplasty.

Menetrier's disease: evolution of disease under histamine-2 receptor antagonists

A 33-yr-old man, with known peptic disease, developed giant thickening of the gastric mucosa and hypoproteinemia. Serial endoscopic and x-ray examinations of the upper gastrointestinal tract were available before and after the development of Menetrier's disease. In a 1-yr interval, erosive gastritis developed in a normal gastric mucosa, which was followed a few months later by hypoproteinemia. The patient developed the disease while being treated with histamine-2 receptor antagonists.

[Dilutional hyponatremia and convulsions after strenuous exercise]

A 15-year-old girl who drank excessive amounts of water while walking in the desert on a warm day, is reported. Due to complaints of fatigue and headache she was treated with more fluids and had a generalized seizure. On admission her sodium level was 125 meq/l and serum muscle enzymes were increased. Hyponatremia due to exertion and dilution is well established and may be more common than thought. It can present as a generalized seizure and with rhabdomyolysis. This case illustrates the danger of overzealous water replacement, especially without adequate replacement of salts. When water discipline is in force this possibility should be considered in patients presenting after prolonged, strenuous exercise or marching.

The application of the Screening Cerebral Assessment of Neppe (BROCAS SCAN) to a neuropsychiatric population

Assessments of higher cortical functioning are often neglected in patients with possible coarse neurobehavioral psychiatric disease, such as dementia, stroke, or focal cerebral lesions. When performed, the short Folstein Mini-Mental State Exam (MMSE) is typically used. The authors' research on 45 neuropsychiatric patients compared the MMSE with a new 20-30-minute bedside examination, the Screening Cerebral Assessment of Neppe (BROCAS SCAN). This screens 10 areas: recall, recognition, orientation, organization of thought, concentration, calculation, agnosia, apraxia, speech, and sensory-motor-reflex phenomena. The BROCAS SCAN (total) correlated extremely well with neuropsychiatric prediction, MRI changes, and neuropsychological testing, and distinguished diagnoses, demonstrating construct and face validity. It also accounted for a larger proportion of variance than the MMSE in correlating with these parameters and was more sensitive in mildly cognitive impaired patients. The briefer first section of the BROCAS SCAN, the core SCAN, also showed statistically relevant relationships to age, diagnosis, MRI, and neuropsychiatric prediction.

Postnatal development and lymphocyte production of jejunal and ileal Peyer's patches in normal and gnotobiotic pigs

The development of the number, size, structure and proliferative capacity of Peyer's patches (PP) in the jejunum and ileum has been studied during the early postnatal period of conventional and germ-free pigs. A mean of 15 discrete PP in the jejunum and upper ileum (jejPP) were counted at birth, and the number increased only gradually. A continuous PP is located in the terminal ileum (ileal PP). The length of both jejPP and ileal PP increased with age due to the increase in follicle size and in the number of follicles in the ileal PP. In older pigs, only the ileal PP regressed to small scattered follicles. In germ-free piglets at 39 and 59 days of age, longer PP were found than in normal new-born piglets, but they were significantly shorter than in age-matched controls. Lymphocyte production was studied by the metaphase-arrest technique using vincristine. Lymphocyte production in follicles increased dramatically with age, while in other compartments, such as the inter-follicular and dome area, a low age-independent production of lymphocytes was found. There were no differences in lymphocytopoiesis between jejPP and ileal PP. The present data show major differences in the development, structure and function of PP in pigs in comparison to other species. These species-specific aspects are important for future studies on the immunological function of PP.