Efficacy and safety of tirbanibulin 1% ointment in actinic keratoses: Data from two phase-III trials and the real-life clinical practice presented at the European Academy of Dermatology and Venereology Congress 2022

BACKGROUND

The 31st European Academy of Dermatology and Venereology (EADV) Congress took place between 7th and 10th of September 2022 in Milan, Italy.

OBJECTIVES

We report presented clinical data on the efficacy/effectiveness, safety and tolerability of tirbanibulin 1% ointment that has recently been licensed for actinic keratosis (AK) of the face or scalp in adults.

METHODS

Summary of presentations given at the EADV Congress.

RESULTS

Prof. Pellacani presented two post hoc analyses from two phase-III trials with AK patients (NCT03285477 [N = 351] and NCT03285490 [N = 351]): A descriptive analysis of medical history, concomitant medications, and safety results confirming a favourable profile for tirbanibulin showing that number of baseline AK lesions was not correlated to severity of local skin reactions. The latter analysis showed that cases of tirbanibulin application site pain or pruritus were few, and most were found to be mild. Prof. Kunstfeld reported six real-life clinical cases in Austria showing good tirbanibulin effectiveness, safety and tolerability for the treatment of new or recurring AK lesions. Results demonstrated that after 2- to 4-month follow-up, tirbanibulin was well tolerated and effective in AK patients. Presentations by Dr. Patel confirmed good outcomes and tolerability of tirbanibulin in Olsen grade 1-2 AK (N = 12) and porokeratosis patients (N = 4) treated once daily for 5 consecutive days in the United Kingdom. Furthermore, real-world experience in solid organ transplant recipients (N = 2) demonstrated effectiveness of tirbanibulin in skin field cancerization treatment. A symposium sponsored by Almirall was conducted during the congress in which Dr. Hadshiew and Dr. Lear brought together their clinical experience in Germany and the United Kingdom respectively. Interesting clinical cases of 5 consecutive days of tirbanibulin treatment compared to other treatments were discussed with attendees, as well as current treatment needs of AK patients.

CONCLUSIONS

This article provides an overview of presentations and symposium discussions, summarizing key phase-III results and real-life clinical experience with tirbanibulin shared by dermatologists across Europe.

Prediction of postnatal circulation in pulmonary atresia/critical stenosis with intact ventricular septum: systematic review and external validation of models

OBJECTIVE

A favorable postnatal prognosis in cases of pulmonary atresia/critical stenosis with intact ventricular septum (PA/CS-IVS) is generally equated with the possibility of achieving biventricular (BV) repair. Identification of fetuses that will have postnatal univentricular (UV) circulation is key for prenatal counseling, optimization of perinatal care and decision-making regarding fetal therapy. We aimed to evaluate the accuracy of published models for predicting postnatal circulation in PA/CS-IVS using a large internationally derived validation cohort.

METHODS

This was a systematic review of published uni- and multiparametric models for the prediction of postnatal circulation based on echocardiographic findings at between 20 and 28 weeks of gestation. Models were externally validated using data from the International Fetal Cardiac Intervention Registry. Sensitivity, specificity, predictive values, area under the receiver-operating-characteristics curves (AUCs) and proportion of cases with true vs predicted outcome were calculated.

RESULTS

Eleven published studies that reported prognostic parameters of postnatal circulation were identified. Models varied widely in terms of the main outcome (UV (n = 3), non-BV (n = 3), BV (n = 3), right-ventricle-dependent coronary circulation (n = 1) or tricuspid valve size at birth (n = 1)) and in terms of the included predictors (single parameters only (n = 6), multiparametric score (n = 4) or both (n = 1)), and were developed on small sample sizes (range, 15-38). Nine models were validated externally given the availability of the required parameters in the validation cohort. Tricuspid valve diameter Z-score, tricuspid regurgitation, ratios between right and left cardiac structures and the presence of ventriculocoronary connections (VCC) were the most commonly evaluated parameters. Multiparametric models including up to four variables (ratios between right and left structures, right ventricular inflow duration, presence of VCC and tricuspid regurgitation) had the best performance (AUC, 0.80-0.89). Overall, the risk of UV outcome was underestimated and that of BV outcome was overestimated by most models.

CONCLUSIONS

Current prenatal models for the prediction of postnatal outcome in PA/CS-IVS are heterogeneous. Multiparametric models for predicting UV and non-BV circulation perform well in identifying BV patients but have low sensitivity, underestimating the rate of fetuses that will ultimately have UV circulation. Until better discrimination can be achieved, fetal interventions may need to be limited to only those cases in which non-BV postnatal circulation is certain. © 2023 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Examining the Role of Microbiota in Emotional Behavior: Antibiotic Treatment Exacerbates Anxiety in High Anxiety-Prone Male Rats

Intestinal microbiota are essential for healthy gastrointestinal function and also broadly influence brain function and behavior, in part, through changes in immune function. Gastrointestinal disorders are highly comorbid with psychiatric disorders, although biological mechanisms linking these disorders are poorly understood. The present study utilized rats bred for distinct emotional behavior phenotypes to examine relationships between emotionality, the microbiome, and immune markers. Prior work showed that Low Novelty Responder (LR) rats exhibit high levels of anxiety- and depression-related behaviors as well as myriad neurobiological differences compared to High Novelty Responders (HRs). Here, we hypothesized that the divergent HR/LR phenotypes are accompanied by changes in fecal microbiome composition. We used next-generation sequencing to assess the HR/LR microbiomes and then treated adult HR/LR males with an antibiotic cocktail to test whether it altered behavior. Given known connections between the microbiome and immune system, we also analyzed circulating cytokines and metabolic factors to determine relationships between peripheral immune markers, gut microbiome components, and behavioral measures. There were no baseline HR/LR microbiome differences, and antibiotic treatment disrupted the microbiome in both HR and LR rats. Antibiotic treatment exacerbated aspects of HR/LR behavior, increasing LRs' already high levels of anxiety-like behavior while reducing passive stress coping in both strains. Our results highlight the importance of an individual's phenotype to their response to antibiotics, contributing to the understanding of the complex interplay between gut microbes, immune function, and an individual's emotional phenotype.

Treatment-induced remission of medulloblastoma using a chemotherapeutic regimen devoid of vincristine in a child with Charcot-Marie-Tooth disease

Charcot-Marie-Tooth (cmt) disease is the most common form of inherited neuropathy. Core features include peripheral neuropathy and secondary axonal degeneration, with a noted distal predominance of limb-muscle wasting, weakness, and sensory loss. Given the significant prevalence of cmt, superimposed neoplastic disease can be encountered within this patient population. Malignancies that are treated with vincristine (a microtubule-targeting agent), even at low doses as part of standard treatment, pose a significant challenge for patients with cmt. Here, we present the case of a child with cmt who was successfully treated for medulloblastoma without vincristine, a standard drug used for treatment of that disease, to avoid the risk of severe debilitating neuropathy. This report is the first of a patient successfully treated for medulloblastoma without vincristine.

Combined Heart and Kidney Transplantation: A 23-Year Experience

BACKGROUND

We report clinical experience with combined heart and kidney transplantation (HKTx) over a 23-year time period.

METHODS

From June 1992 to August 2015, we performed 83 combined HKTx procedures at our institution. We compared the more recent cohort of 53 HKTx recipients (group 2, March 2009 to August 2015) with the initial 30 previously reported HKTx recipients (group 1, June 1992 to February 2009). Pre-operative patient characteristics, peri-operative factors, and post-operative outcomes including survival were examined.

RESULTS

The baseline characteristics of the two groups were similar, except for a lower incidence of ethanol use and higher pre-operative left-ventricular ejection fraction, cardiac output, and cardiac index in group 2 when compared with group 1 (P = .007, .046, .037, respectively). The pump time was longer in group 2 compared with group 1 (153.30 ± 38.68 vs 129.60 ± 37.60 minutes; P = .007), whereas the graft ischemic time was not significantly different between the groups, with a trend to a longer graft ischemic time in group 2 versus group 1 (195.17 ± 45.06 vs 178.07 ± 52.77 minutes; P = .056, respectively). The lengths of intensive care unit (ICU) and hospital stay were similar between the groups (P = .083 and .39, respectively). In addition, pre-operative and post-operative creatinine levels at peak, discharge, 1 year, and 5 years and the number of people on post-operative dialysis were similar between the groups (P = .37, .75, .54, .87, .56, and P = .139, respectively). Overall survival was not significantly different between groups 2 and 1 for the first 5 years after transplant, with a trend toward higher survival in group 2 (P = .054).

CONCLUSIONS

The most recent cohort of combined heart and kidney transplant recipients had similar ICU and hospital lengths of stay and post-operative creatinine levels at peak, discharge, and 1 and 5 years and a similar number of patients on post-operative dialysis when compared with the initial cohort. Overall survival was not significantly different between the later and earlier groups, with a trend toward higher overall survival at 5 years in the more recent cohort of patients. In selected patients with co-existing heart and kidney failure, combined heart and kidney transplantation is safe to perform and has excellent outcomes.

Transcriptomic Signature of the CD24hi CD38hi Transitional B Cells Associated With an Immunoregulatory Phenotype in Renal Transplant Recipients

The role of B cells after transplant regarding allograft rejection or tolerance has become a topic of major interest. Recently, in renal transplant recipients, a B cell signature characterized by the overexpression of CD19⁺ CD38^hi CD24^hi transitional B cells has been observed in operationally tolerant patients and in belatacept-treated patients with significantly lower incidence of donor-specific antibodies. The phenotypic and functional characterization of these transitional B cells is far from exhaustive. We present the first transcriptomic and phenotypic analysis associated with this cell phenotype. Three populations were studied and compared: (i) transitional CD24^hi CD38^hi , (ii) CD24⁺ CD38^- , and (iii) CD24^int CD38^int B cells. Transcriptome bioinformatic analysis revealed a particular signature for the CD24^hi CD38^hi population. Phenotypic analysis showed that CD24^hi CD38^hi transitional B cells also expressed CD9, CD10, CD1b and inducible T cell costimulator ligand (ICOS-L) markers. In addition, we found enrichment of IL-10⁺ cells among CD24^hi CD38^hi cells expressing ICOS-L and CD1b, the latter showing regulatory properties. Renal transplant recipients treated with belatacept exhibited significant expression of CD1b. Our results show that transitional CD24^hi CD38^hi B cells exhibit a distinct and specific profile, and this could be helpful for understanding of immune-regulatory mechanisms and immune monitoring in the field of organ transplant and autoimmune disease.

Induction of Hematopoietic Microchimerism by Gene-Modified BMT Elicits Antigen-Specific B and T Cell Unresponsiveness toward Gene Therapy Products

BACKGROUND

Gene therapy is a promising treatment option for hemophilia and other protein deficiencies. However, immune responses against the transgene product represent an obstacle to safe and effective gene therapy, urging for the implementation of tolerization strategies. Induction of a hematopoietic chimerism via bone marrow transplantation (BMT) is a potent means for inducing immunological tolerance in solid organ transplantation.

OBJECTIVES

We reasoned, here, that the same viral vector could be used, first, to transduce BM cells for inducing chimerism-associated transgene-specific immune tolerance and, second, for correcting protein deficiencies by vector-mediated systemic production of the deficient coagulation factor.

METHODS

Evaluation of strategies to induce B and T cell tolerance was performed using ex vivo gene transfer with lentiviral (LV) vectors encoding coagulation factor IX (FIX) or the SIINFEKL epitope of ovalbumin. Following induction of microchimerism via BMT, animals were challenged with in vivo gene transfer with LV vectors.

RESULTS

The experimental approach prevented humoral immune response against FIX, resulting in persistence of therapeutic levels of circulating FIX, after LV-mediated gene transfer in vivo. In an ovalbumin model, we also demonstrated that this approach effectively tolerized the CD8⁺ T cell compartment in an antigen-specific manner.

CONCLUSION

These results provide the proof-of-concept that inducing a microchimerism by gene-modified BMT is a powerful tool to provide transgene-specific B and T cell tolerance in a gene therapy setting.

Administration of low doses of IL-2 combined to rapamycin promotes allogeneic skin graft survival in mice

Human CD4(+) CD25(+) FoxP3(+) regulatory T cells (Tregs) prevent allogeneic graft rejection by inhibiting T cell activation, as has been shown in mouse models. Recently, low-dose IL-2 administration was shown to specifically activate Tregs but not pathogenic conventional T cells, leading to resolution of type 1 diabetes in nonobese diabetic mice. We therefore tested the ability of low-dose IL-2 to prevent allogeneic skin graft rejection. We found that while IL-2 alone was inefficient in preventing rejection, combined with rapamycin, IL-2 treatment promoted skin graft survival both in minor disparate and semi-allogeneic skin graft combinations. Tregs are activated by this combined treatment while conventional CD4(+) cell expansion and activation are markedly inhibited. Co-administration of anti-CD25 antibodies dramatically reduces the effect of the IL-2/rapamycin treatment, strongly supporting a central role for Treg activation. Thus, we provide the first preclinical data showing that low-dose IL-2 combined with rapamycin can significantly delay transplant rejection in mice. These findings may form the rational for clinical evaluation of this novel approach for the prevention of transplant rejection.

Early-life exposure to the SSRI paroxetine exacerbates depression-like behavior in anxiety/depression-prone rats

Selective serotonin reuptake inhibitor (SSRI) antidepressants are the mainstay treatment for the 10-20% of pregnant and postpartum women who suffer major depression, but the effects of SSRIs on their children's developing brain and later emotional health are poorly understood. SSRI use during pregnancy can elicit antidepressant withdrawal in newborns and increase toddlers' anxiety and social avoidance. In rodents, perinatal SSRI exposure increases adult depression- and anxiety-like behavior, although certain individuals are more vulnerable to these effects than others. Our study establishes a rodent model of individual differences in susceptibility to perinatal SSRI exposure, utilizing selectively bred Low Responder (bLR) and High Responder (bHR) rats that were previously bred for high versus low behavioral response to novelty. Pregnant bHR/bLR females were chronically treated with the SSRI paroxetine (10 mg/kg/day p.o.) to examine its effects on offspring's emotional behavior and gene expression in the developing brain. Paroxetine treatment had minimal effect on bHR/bLR dams' pregnancy outcomes or maternal behavior. We found that bLR offspring, naturally prone to an inhibited/anxious temperament, were susceptible to behavioral abnormalities associated with perinatal SSRI exposure (which exacerbated their Forced Swim Test immobility), while high risk-taking bHR offspring were resistant. Microarray studies revealed robust perinatal SSRI-induced gene expression changes in the developing bLR hippocampus and amygdala (postnatal days 7-21), including transcripts involved in neurogenesis, synaptic vesicle components, and energy metabolism. These results highlight the bLR/bHR model as a useful tool to explore the neurobiology of individual differences in susceptibility to perinatal SSRI exposure.

Antigen quality determines the efficiency of antitumor immune responses generated in the absence of regulatory T cells

The observation that depletion or inhibition of regulatory T cells (Tregs) unleashes efficient antitumor effector immune responses that can lead to tumor eradication in mice has opened new perspectives for the development of cancer immunotherapy. The quality and overall efficiency of the effector immune responses induced in the absence of Tregs seem to depend on multiple factors that determine the result of a battle involving effector T cells (Teffs), Tregs and tumor cells. In this study, we investigated the quality of tumor-associated antigens (TAAs) as one such factor. We show that the presence of a strong dominant antigen is required for the induction of effector responses capable of tumor eradication in the absence of Tregs. The sole addition of a dominant antigen on tumor cells does not change tumor growth in unmanipulated mice, but improves tumor eradication rate from a few to almost 100% in the absence of Tregs. This eradication can be shown to result from the recruitment and activation of specific Teffs recognizing this antigen. We also show that the presence of such dominant antigens has the side effect of restricting the breadth of the immune response to other TAAs, which could favor the generation of escape mutant by tumor editing. Taken together, our results highlight the potential, and some requirements for cancer immunotherapy based on Treg depletion. They also show that, ultimately, tumor fate depends on multiple factors that should all be taken into consideration for the design of more efficient immunotherapy.

Anastomotic leaks: what is the best diagnostic imaging study?

PURPOSE

Postoperative anastomotic leaks are one of the most devastating consequences of colorectal surgery. Diagnostic imaging for upper gastrointestinal anastomotic leaks has been evaluated and reported on extensively. No study has compared the utility and effectiveness of CT scans and water-soluble enemas for the identification of postoperative lower gastrointestinal anastomotic leaks. The present study was designed to evaluate and compare these two common radiographic imaging modalities in detecting lower gastrointestinal anastomotic leaks.

METHODS

A retrospective chart review was performed that identified 36 patients during a seven-year period who underwent reoperative surgery for a lower gastrointestinal anastomotic leak. Patient's imaging studies were classified as positive if extravasation of contrast material was demonstrated. When negative, a study was retrospectively reviewed in an attempt to identify findings suggestive of an anastomotic leak.

RESULTS

There were 36 patients identified with a postoperative lower gastrointestinal leak requiring surgical intervention. There were 28 of 36 patients (78 percent) re-explored on the basis of a radiologic study demonstrating an anastomotic leak. A total of 27 CT scans were performed, of which 4 (14.8 percent) were considered positive for an anastomotic leak. On review of the remaining negative CT scans, nine (33.3 percent) were considered descriptive positive with a large amount of fluid or air in the peritoneal cavity but without obvious extravasation of contrast. Eighteen patients were evaluated with a water-soluble enema and 15 (83.3 percent) demonstrated extravasation of contrast material. In the 26 patients with a distal anastomotic leak, 17 water-soluble enemas were performed, with 15 (88 percent) demonstrating a leak. In contrast, only 2 of 17 (12 percent) CT scans were positive in this group of patients (P < 0.001). There were ten patients who initially had a CT scan followed by a water-soluble enema. Of these patients, eight of nine (88 percent) initially had a negative CT scan but were considered to be clinically suspicious of having an anastomotic leak and subsequently had a leak demonstrated on a water-soluble enema.

CONCLUSIONS

Early intervention in patients who develop an anastomotic leak can be shown to improve the ultimate outcome, especially with respect to mortality. It is usually necessary to obtain objective tests of anastomotic integrity because of the nonspecificity of clinical signs. Our study supported the superiority of water-soluble enema to CT imaging in patients in whom both modalities were used. This difference was most pronounced for distal anastomotic leaks, whereas no radiologic imaging study proved effective in evaluating proximal anastomoses.

Strong-field atomic phase matching

We interpret a learning-control experiment with the goal of optimizing multiphoton population transfer in atomic sodium in the strong-field limit. Despite multiple experimental constraints, a learning algorithm discovers optimal pulses that can be understood in terms of a simple dynamic picture of the atom-field interaction. We show that the shaped pulses counteract the dynamic Stark-induced stimulated emission that would otherwise impede the efficient use of a pi pulse to invert a multiphoton transition.

Therapeutic potential of CD4+ CD25+ regulatory T cells in allogeneic transplantation

The subpopulation of CD4+ CD25+ immunoregulatory T cells constitutes less than of the entire CD4+ T-cell pool in mice and 2% in humans. These cells play a crucial role in the control of autoimmune processes. More recently, in vitro and in vivo data also indicate that CD4+ CD25+ immunoregulatory T cells can regulate alloreactivity. This renders them good candidates for innovative strategies in the field of transplantation. Inducing a state of immune tolerance with immunoregulatory T cells would alleviate the need for immunosuppression, and the occurrence of late allograft failure represents a major goal of transplantation immunology. Here we discuss how these naturally occurring CD4+ CD25+ immunoregulatory T cells can be used to modulate alloreactivity in hematopoietic stem cell and solid organ transplantation.

Effect of combined cytostatic cyclosporin A and cytolytic suicide gene therapy on the prevention of experimental graft-versus-host disease

The immunosuppressive drug cyclosporin A (CsA) represents the standard preventive treatment of graft-versus-host disease (GVHD), the main complication of allogeneic hematopoietic stem cell transplantation (HSCT). However, its efficacy is only partial and many patients develop lethal GVHD despite CsA. A strategy of genetic immunosuppression based on conditional elimination of donor T cells expressing the Herpes simplex type 1 thymidine kinase (TK) suicide gene was recently developed. In this system, ganciclovir (GCV) selectively kills dividing but not quiescent TK T cells. Since CsA is known to have a cytostatic effect on T cells, it could negatively interfere with the division-dependent TK gene therapy. We thus tested whether administration of CsA would antagonize elimination of alloreactive donor TK T cells mediated by GCV in a murine model of GVHD. In vivo experiments revealed that, contrary to GCV, CsA only transiently controlled alloactivation-induced T cell proliferation, and likewise could not prevent lethal GVHD. When T cells resumed proliferation under CsA, they were however still sensitive to GCV. Survival, as well as immune reconstitution, was excellent in mice treated with GCV alone or in combination with CsA. These observations should help to design improved suicide gene therapy trials in the field of allogeneic HSCT.

Penile paraffinoma: self-injection with mineral oil

We present a 64-year-old patient with a 9-cm firm, irregular penile mass associated with phimosis, erectile dysfunction, and voiding difficulty. After he reluctantly admitted to multiple penile mineral oil self-injections for enlargement, surgical excision was performed. Pathologic examination was consistent with mineral oil granuloma (paraffinoma). Within several weeks after surgery, his erectile dysfunction and voiding complaints resolved. Paraffinomas have been encountered with the use of various oily substances injected for cosmetic purposes. Despite early warnings, these agents continued to be used to treat conditions ranging from hemorrhoids to wrinkles and even baldness. Fortunately, most of these fads have been abandoned by medical professionals, but the complicating lesions have been documented as having lag times as long as 30 years. Complete surgical excision remains the treatment of choice to prevent recurrence. Increased public awareness is needed for the prevention of this physically and psychologically debilitating problem.

Division rate and phenotypic differences discriminate alloreactive and nonalloreactive T cells transferred in lethally irradiated mice

After non-T-cell-depleted allogeneic hematopoietic stem cell transplantation (HSCT), both alloreactive and homeostatic signals drive proliferation of donor T cells. Host-reactive donor T cells, which proliferate on alloantigen stimulation, are responsible for the life-threatening graft-versus-host disease. Non-host-reactive donor T cells, which proliferate in response to homeostatic signals, contribute to the beneficial peripheral T-cell reconstitution. The elimination of alloreactive T cells is a major therapeutic challenge for HSCT and would greatly benefit from their specific identification. After T-cell transfer in lymphopenic recipients, the present results show that alloreactive T cells rapidly divided; up-regulated CD69, CD25, and CD4 molecules; and down-regulated CD62L. In contrast, nonalloreactive T cells started to divide later and did not up-regulate CD69, CD25, and CD4. Thus, these 2 cell populations can be effectively discriminated. This should facilitate the specific depletion of alloreactive T cells in allogeneic HSCT.

Suicide gene therapy of graft-versus-host disease: immune reconstitution with transplanted mature T cells

After allogeneic hematopoietic stem cell transplantation (HSCT), mature transplanted T cells play a major role in restoration of the immune system. However, they can also induce a life-threatening complication: graft-versus-host disease (GVHD). Suicide gene therapy of GVHD aims to selectively eliminate alloreactive T cells mediating GVHD while sparing nonalloreactive T cells that should contribute to immune reconstitution. It was demonstrated previously that treatment with ganciclovir (GCV) can control GVHD in mice by killing donor T cells engineered to express the thymidine kinase (TK) suicide gene. TK allows phosphorylation of nontoxic GCV into triphosphate GCV, which is selectively toxic for dividing cells. Thus, in the TK-GCV system, the specificity of cell killing depends on the cycling status of TK T cells rather than allogeneic recognition. This is a potential drawback because in recipients of lymphopenic allogeneic HSCT, alloreactive and homeostatic signals drive the proliferation of donor T cells. It is shown here that the onset of alloreactive T-cell division occurs earlier than that of nonalloreactive T cells, thus establishing a time frame for GCV administration. A 7-day GCV treatment initiated at the time of HSCT allowed efficient prevention of GVHD, while sparing a pool of nondividing donor TK T cells. These cells later expanded and contributed to the replenishment of the recipient immune system with a diversified T-cell receptor repertoire. These results provide a rationale for designing the therapeutic scheme when using TK-GCV suicide gene therapy in allogeneic HSCT.

The adoption and diffusion of ambulatory care retirement housing communities

This article is the result of an exploratory study into the factors slowing the adoption of a retirement housing community. Through research, we have identified a list of primary issues which are impeding the movement of the retirement housing community concept from the introductory stage of the product life cycle into its growth stage. We have then related each of the issues to the general factors which serve to accelerate the adoption rate and provided suggestions concerning specific strategies that will overcome each of the factors slowing the adoption rate.

Preservation of graft-versus-infection effects after suicide gene therapy for prevention of graft-versus-host disease

The main complications following allogeneic hematopoietic stem cell transplantation are graft-versus-host disease and poor immune reconstitution leading to severe infections. Mature donor T cells present in the transplant facilitate T cell reconstitution in adults, but also induce graft-versus-host disease, which itself impairs immune reconstitution. Thus, infusing a large number of donor T cells with a diverse repertoire should accelerate functional immune reconstitution after transplantation, only if graft-versus-host disease can be controlled. We previously demonstrated that preventive treatment with ganciclovir could control graft-versus-host disease in mice if donor T cells are made to express viral thymidine kinase as a "suicide" gene. Here we evaluated the recovery of functional antiviral immune responses in such mice. Irradiated mice received an allogeneic hematopoietic stem cell transplantation with thymidine kinase-expressing T cells and were protected from graft-versus-host disease by ganciclovir treatment, and then challenged with lymphocytic choriomeningitis virus. Grafted mice could mount efficient antilymphocytic choriomeningitis virus immune responses leading to viral elimination. Furthermore, when transplanted cells were obtained from mice previously immunized against lymphocytic choriomeningitis virus, grafted mice developed memory-type accelerated responses against the virus. We conclude that efficient graft-versus-infection effects can be mediated by naive T cells and memory donor T cells that persist after suicide gene therapy for prevention of graft-versus-host disease.

T-Cell suicide gene therapy for organ transplantation: induction of long-lasting tolerance to allogeneic heart without generalized immunosuppression

Standard immunosuppressive drugs used for allogeneic organ transplantation do not specifically target alloreactive T cells and must be given for the lifetime of the patient, resulting in significant morbidity and mortality. We aimed to induce experimental immune tolerance to vascularized heart allograft using a suicide gene allowing selective elimination of dividing T cells expressing Herpes simplex virus type 1 thymidine kinase upon ganciclovir administration. We show that without ganciclovir, transgenic mice selectively expressing thymidine kinase in T cells rejected a vascularized cardiac allograft in 7 days. In contrast, allograft was definitively accepted after a 7-day course of ganciclovir initiated at the time of allotransplantation. Interestingly, T cells from both rejecting and tolerant mice proliferated in response to donor or third-party allogeneic stimulation. This state of tolerance was challenged through a second vascularized cardiac allotransplantation. Third-party allografts were rejected while those syngeneic to the first allograft were accepted without any additional treatment. These results show that short-term pharmacogenetic immunosuppression can induce long-lasting, robust, and specific tolerance to solid vascularized allograft without generalized continuous immunosuppression.

Efficacy and safety of the novel ultrasound contrast agent perflutren (definity) in patients with suboptimal baseline left ventricular echocardiographic images

Suboptimal left ventricular (LV) cavity visualization and endocardial border delineation often compromise the clinical utility of echocardiography. This study examines the safety and efficacy of perflutren, a novel ultrasound contrast agent, for LV cavity opacification and endocardial border delineation in patients with suboptimal baseline echocardiograms. In a multicenter, randomized, placebo-controlled, double-blind trial, 211 patients with suspected cardiac disease and suboptimal baseline echocardiograms were enrolled at 17 sites. Two intravenous injections of either placebo (saline) or perflutren (5 or 10 microl/kg) were given approximately 30 minutes apart. Images of the apical 4- and 2-chamber views were acquired and scored. Perflutren opacified the LV cavity after both dosages (5 and 10 microl/kg dosages). Clinically useful contrast was observed in 89% of patients who received perflutren and in 0% of patients who received placebo (p < 0.01). Quantitative assessment of LV opacification with videodensitometry showed similar results. The mean duration of clinically useful contrast was 90 seconds. Improvement in endocardial border delineation was demonstrated in 91% of patients who received perflutren and in 12% of those who received placebo (p < 0.001). Following perflutren, an average of 4 more segments per patient were evaluable compared with baseline. Salvage of nondiagnostic baseline examinations by perflutren was demonstrated in 48% of eligible subjects. The safety profile of perflutren was similar to placebo. These data indicate that administration of perflutren to patients with suboptimal baseline images is well tolerated and provides substantial LV cavity opacification and improvement in endocardial border delineation.

Transient control of a virus-induced immunopathology by genetic immunosuppression

The ability to control T cell reactivity using suicide genes opens new perspectives for the treatment of T cell-mediated diseases. The therapeutic effect is achieved by the selective killing of thymidine kinase gene-modified activated T cells by ganciclovir (GCV). This strategy has been shown to control T cell alloreactivity efficiently after bone marrow or solid organ transplantation. Here, we aimed to determine whether an immunopathological process induced by a viral infection could be controlled by GCV when T cells express a thymidine kinase transgene. When transgenic mice were infected with the lymphocytic choriomeningitis virus, administration of GCV resulted in an efficient, but only transient, control of the immunopathological immune response. Further analysis revealed the existence of a minute population of GCV-insensitive T cells. These cells expand in response to the virus despite the presence of GCV and cause immunopathology before viral elimination is finally obtained. Thus, when confronted with a replicative virus, the efficacy of this genetic immunosuppression strategy is highly dependent on the presence of even small numbers of GCV-insensitive cells. These results emphasize the need for sufficient preclinical investigations with regard to the pathology and the nature of the immune response if suicide gene transfer is envisioned for new therapeutic indications.

Prolonged allograft survival through conditional and specific ablation of alloreactive T cells expressing a suicide gene

BACKGROUND

Control of antidonor activated T cells involved in allograft rejection while preserving immunocompetence is a challenging goal in transplantation. Engineered T cells expressing a viral thymidine kinase (TK) suicide gene metabolize the nontoxic prodrug ganciclovir (GCV) into a metabolite toxic only to dividing cells. We evaluated this suicide gene strategy for inducing transplantation tolerance in mice.

METHODS

Transgenic mice expressing TK in mature T cells were analyzed for (i) specific T-cell depletion under GCV treatment upon various stimulations; (ii) outcome of allogeneic nonvascularized skin or heart allografts under a short 14-day GCV treatment initiated at the time of transplantation; and (iii) the capacities of T cells from such allotransplanted mice to proliferate in mixed lymphocyte reactions and to induce graft-versus-host disease in irradiated recipients with the genetic background of the donor allograft.

RESULTS

Upon in vitro or in vivo GCV treatment, only activated dividing TK T cells but not B cells were efficiently depleted. Acute rejection of allogeneic grafts was prevented and a significant prolongation of graft survival was obtained, although associated with signs of chronic rejection. Prolonged skin graft survival correlated with decreased in vitro and in vivo T-cell reactivities against donor alloantigens, whereas overall immunocompetence was preserved.

CONCLUSIONS

Efficient and specific depletion of alloreactive TK T cells can be achieved by administrating GCV. These results open new perspectives for the control of allogeneic graft rejection using suicide gene therapy.

Management of porphyria cutanea tarda in the setting of chronic renal failure: a case report and review

The treatment of porphyria cutanea tarda (PCT) in patients with chronic renal failure poses a therapeutic challenge. In the absence of renal failure, phlebotomy and oral antimalarials have been the standard of care for PCT. However, in the presence of renal failure, associated chronic anemia often precludes the use of phlebotomy, and oral antimalarials are usually ineffective. We describe a patient with severe symptomatic PCT and chronic renal failure whose disease was successfully managed with a combination of high-dose erythropoietin and small volume phlebotomy. We also review several previously reported approaches to management of PCT in the setting of renal failure, which include small repeated phlebotomy, erythropoietin, deferoxamine, chloroquine, plasma exchange, high-efficiency/high-flux hemodialysis, cholestyramine, charcoal hemoperfusion, and kidney transplantation. An algorithm for the management of these patients is proposed.

Infusion versus bolus contrast echocardiography: a multicenter, open-label, crossover trial

BACKGROUND

In current practice, contrast echocardiography is performed with single or multiple bolus injections, which often result in an uncontrolled period of attenuation followed by transient left ventricular opacification (LVO). Because a "slow bolus" appears to reduce attenuation and prolong LVO, we hypothesized that a controlled infusion of contrast might provide a more uniform contrast effect with less attenuation and longer contrast duration.

METHODS AND RESULTS

We sought to test the hypothesis by using an infusion of contrast (DEFINITY [perflutren], The DuPont Pharmaceuticals Co, Medical Imaging, North Billerica, Mass) that is stable when diluted in saline in a randomized, multicenter, controlled, crossover trial. Sixty-four patients with poor noncontrast images were recruited at 3 centers and randomly assigned to 2 single "slow" bolus injections of contrast (10 microL/kg each over a period of 30 to 60 seconds) or an infusion (1. 3 mL in 50 mL normal saline initially at 4.0 mL/min) of contrast. Patients then returned within 24 to 72 hours for the alternative form of contrast delivery. Three independent experienced echocardiographers viewed 30 seconds of videotape for all optimal baseline and optimal contrast images to score LVO and qualitatively assessed endocardial border evaluability. The duration of adequate LVO then was independently assessed by review of the entire videotape. Three independent sonographers traced single-frame, digitally captured images to measure the length of the contiguous endocardial border visualized. Both bolus and infusion administration demonstrated improved LVO (>90% by all blinded readers, P <.01) and endocardial border visualized (mean increase of 1.8 to 4.7 cm at both end-diastole and end-systole, all P <.05) as compared with baseline images. However, contrast infusion resulted in a longer duration of LVO (range of mean durations for each reader, 158 to 174 seconds longer, P <.05) and a shorter duration of attenuation (18 to 54 seconds, P <.05) compared with either bolus injection. There were no severe adverse events with contrast infusion.

CONCLUSIONS

Contrast echocardiography delivered as an infusion optimizes the contrast effect by decreasing the attenuation period, extending the LVO duration, and providing a uniform contrast effect that may be useful in obtaining multiple echocardiographic views, stress echocardiography, myocardial perfusion imaging, and applications in which blood flow must be quantified.

Ganciclovir-sensitive acute graft-versus-host disease in mice receiving herpes simplex virus-thymidine kinase-expressing donor T cells in a bone marrow transplantation setting

BACKGROUND

The use of donor T cells expressing the herpes simplex thymidine kinase (HSV-TK) gene followed by ganciclovir (GCV) treatment could allow for specific modulation of the alloreactivity occurring after bone marrow transplantation. We are presently exploring such an approach in a phase I clinical trial.

METHODS

To examine the beneficial effect of administrating HSV-TK-expressing donor T lymphocytes +/- GCV treatment on acute graft-versus-host disease (aGVHD) control, irradiated Balb/c or C57BL/6 mice underwent transplantation with allogeneic bone marrow cells in conjunction with CD3+ allogeneic splenocytes from transgenic mice expressing an HSV-TK transgene. GCV treatment was initiated upon the occurrence of severe aGVHD.

RESULTS

GCV treatment resulted in a 40-60% long-term survival rate of GVHD-free recipients having received HSV-TK-expressing T cells, whereas only 0-6% of mice survived without GCV treatment. Lethal aGVHD occurred in all the control animals having received non-HSV-TK-expressing T cells, irrespective of GCV treatment.

CONCLUSION

Our results demonstrate that the administration of donor HSV-TK-expressing T cells to hematopoietic stem cell graft recipients followed by GCV treatment at the onset of severe aGVHD significantly reduces aGVHD-induced mortality and results in GVHD-free surviving recipients.

The cutaneous porphyrias

Deficiencies of 7 enzymes in the heme biosynthetic pathway result in the development of porphyrias. Two of the porphyrias, aminolevulinate dehydratase deficiency porphyria and acute intermittent porphyria do not have cutaneous findings. Cutaneous findings in the other porphyrias could be subdivided into acute phototoxicity and subacute phototoxicity. In addition, 2 of the porphyrias, hereditary coproporphyria and variegate porphyria have both cutaneous and neurovisceral findings. Now that chromosomal assignments for all the genes of the defective enzymes have been mode, prenatal diagnosis is possible for congenital erythropoietic porphyria, and in vitro gene therapy has been successfully performed for congenital erythropoietic porphyria and erythropoietic protoporphyria.

Immunological defects after suicide gene therapy of experimental graft-versus-host disease

Donor T cells are beneficial for engraftment, immune reconstitution, and antileukemic effects after allogeneic marrow transplantation, but they also cause graft-versus-host disease. Treatment with ganciclovir can control graft-versus-host disease if donor T cells are genetically engineered to express viral thymidine kinase. Clinical protocols with thymidine kinase-expressing T cells currently prescribe the curative use of ganciclovir for genetic immunosuppression only after clinical manifestations of graft-versus-host disease have appeared. The aim of this work was to compare early/preventive versus delayed/curative treatment of GVHD. Here, we found that ganciclovir administered early after experimental marrow transplantation was highly effective in preventing graft-versus-host disease caused by thymidine kinase-expressing T cells, and surviving recipient mice were able to mount a T cell-dependent B cell response. In contrast, curative ganciclovir administration later after transplantation was much less effective in treating graft-versus-host disease and surviving recipients had markedly impaired immune function. These findings should be considered in the development of future clinical trials using thymidine kinase-expressing T cells; to date, such trials have envisaged the use of GCV to treat only declared graft-versus-host disease. The use of thymidine kinase-expressing T cells for conditional elimination of activated T cells after allogeneic marrow transplantation offers a promising new approach for the control of graft-versus-host disease. The versatility of the thymidine kinase/ganciclovir system offers clinical options depending on whether thymidine kinase-expressing T cells are infused at the time of bone marrow transplantation or in a delayed manner, and depending on whether GCV is administered in an early/preventive or delayed/curative manner. The rationale underlying these options is more complex than it may appear and is likely to have a profound impact on the efficacy of such treatments. In the present work, we analyze the immunological impact when GCV is administered in an early/preventive or delayed/curative manner. Our results demonstrate that the delayed/curative strategy is clearly associated with severe immunological defects. To our knowledge, this is the first report of immunodeficiency subsequent to suicide gene therapy for GVHD.

Differing susceptibility of echocardiographic contrast agents to adverse effects of biologic factors: multicenter, videodensitometric comparison of octafluoropropane-filled microspheres with air-filled microspheres for left ventricular opacification

BACKGROUND

Echocardiographic contrast enhancement of the left ventricle has diagnostic value in the assessment of regional and global left ventricular (LV) function. The efficacy of both octafluoropropane-filled human albumin microbubbles (OCTA) and of air-filled human albumin microbubbles (AIR) for LV endocardial delineation and qualitative LV opacification has previously been reported. However, pulmonary disease, obesity, impaired LV function, and decreased echogenicity may diminish the efficacy of contrast agents for LV opacification. The purpose of this study was to compare the susceptibility of 2 contrast agents currently approved by the Food and Drug Administration to these biologic factors.

METHODS

To compare quantitative LV opacification with OCTA (0.2, 0. 5, 3.0, 5.0 mL) versus AIR (0.08 mL/kg, 0.22 mL/kg), we performed videodensitometry in 199 patients (average age 59.2 +/- 13.3 years, 79% men) studied in 2 identical, prospective, multicenter, blinded trials, of whom 74 had impaired LV function, pulmonary disease, or both, 70 were obese (body mass index >30 kg/m(2)), and 45 were nonechogenic (>/=4 of 6 endocardial segments were not seen in the apical 4-chamber view). Changes in videodensity from noncontrast to contrast agent with the same gain settings were determined at end diastole and end systole (gray scale 0 to 255 U) for 2 regions of interest: left ventricle apex-to-mid-cavity and mid-cavity-to-base. The relative influence of clinically evident pulmonary disease, impaired LV function on echocardiography, and echogenicity on LV opacification produced by both contrast agents was determined by multivariate analysis.

RESULTS

Significant videodensity increases ranging from 67% to 143% were observed with both agents. At the recommended initial doses (0.5 mL for OCTA, 0.22 mL/kg for AIR), OCTA produced greater opacification than AIR in both regions of interest and at both phases of the cardiac cycle. Poor LV function was associated with decreased LV opacification for AIR but not for OCTA. Diminished echogenicity was more strongly associated with impaired opacification for AIR than for OCTA. Obesity and clinically evident pulmonary disease were associated with diminished chamber opacification with both OCTA and AIR.

CONCLUSIONS

In addition to the superiority of octafluoropropane-filled microspheres to air-filled microspheres for LV opacification, the efficacy of OCTA is relatively unaffected by impaired LV function and is less susceptible to the effects of poor echogenicity than AIR.

Suicide gene-mediated modulation of graft-versus-host disease

The development of suicide genes and progress in retroviral gene transfer to T-cells open new perspectives for the treatment of graft-versus-host disease (GVHD) after allogeneic bone marrow transplantation (BMT) for leukemia and lymphoma. Indeed, suicide genes that metabolize inactive prodrugs into compounds toxic for dividing cells provide a powerful means for the pharmacogenetic control of T-cell reactivity. Here, we demonstrate the selective destruction of activated TK-transgenic T-cells in vivo and develop two new transgenic lines which should be useful for preclinical studies of suicide gene therapy strategies for GVHD.

Deletional and mutational analyses of the human CD4 gene promoter: characterization of a minimal tissue-specific promoter

In recent years, considerable interest has arisen in understanding the mechanisms of the CD4 gene transcriptional control which resulted in the identification of a promoter, enhancers and a silencer. While the murine CD4 gene promoter has been well studied, little is known about its human counterpart that we previously identified as a 1.1 kb region. Here, we show that the -170/+20 region represents a minimal tissue-specific promoter with a size compatible with its inclusion in viral vectors for gene therapy. In addition, mutational analyses provided evidence that this fragment contains three regions critical for transcriptional activity: an initiator-like sequence, an Ets consensus site and an ATF consensus site. The latter site is absent in the murine promoter, suggesting that some differences exist between the transcriptional control of the human and murine CD4 genes.

Effect of atenolol or metoprolol on arbutamine stress echocardiography in patients suspected of having coronary artery disease

Arbutamine stress echocardiography was performed in 81 patients with suspected coronary artery disease. Arbutamine infusion, using a dedicated closed-loop delivery device, provided comparable myocardial stress in patients receiving beta-1 blockers versus those who were not.

Erythema multiforme associated with contact dermatitis to poison ivy: three cases and a review of the literature

Erythema multiforme (EM) is a hypersensitivity reaction that occurs mainly after exposure to certain medications or in the setting of infection, most commonly that due to herpes simplex virus. Rare cases of EM have been reported after allergic contact dermatitis due to various substances. There has been one case in the literature of EM following Rhus contact dermatitis. We report three patients who developed EM after allergic contact dermatitis due to poison ivy. In all three patients, targetoid lesions developed primarily on the palms and soles, either after a brief course of prednisone or during its taper. Two of the patients have had more than one episode of EM after poison ivy dermatitis. Although EM has been described after allergic contact dermatitis due to a variety of antigens (nickel being the most common), there is only one report in the literature of EM following Rhus contact dermatitis. Given the prevalence of allergic contact dermatitis due to poison ivy, this may be an under-reported complication.

Fertile homozygous transgenic mice expressing a functional truncated herpes simplex thymidine kinase delta TK gene

Dividing cells expressing the Herpes simplex type 1 thymidine kinase (TK) can be killed upon ganciclovir treatment. Likewise, conditional cell knock-out can be obtained in transgenic mice expressing a TK gene placed under the control of tissue-specific regulatory sequences. Such animals provide powerful experimental systems for assessing the functional role of specific cell populations through their time-controlled ablation. However, whatever the regulatory sequences used, a leaky toxic overexpression of TK in testis renders male TK-transgenic mice sterile and prevents the generation of homozygous TK-expressing animals. To solve this problem, we designed a truncated TK variant (delta TK) not expressed in the testis. We generated transgenic mice expressing delta TK under the control of lymphocyte-specific regulatory sequences derived from the CD4 gene. The delta TK protein expressed in T-lymphocytes allowed the conditional ablation of activated T-cells in vitro and in vivo. Importantly, for one transgenic line we could generate fertile homozygous mice harboring a functional delta TK transgene. delta TK should thus dramatically facilitate the development of transgenic mice expressing a conditional suicide gene.

Improved left ventricular endocardial border delineation and opacification with OPTISON (FS069), a new echocardiographic contrast agent. Results of a phase III Multicenter Trial

OBJECTIVES

The echocardiographic contrast-enhancing effects and safety profile of ALBUNEX (a suspension of air-filled albumin microspheres) were compared with the new contrast agent OPTISON (formerly FS069: a suspension of albumin microspheres containing the gas perfluoropropane) in 203 patients with inadequate noncontrast echocardiograms.

BACKGROUND

The efficacy of ALBUNEX has been limited by its short duration of action. By using perfluoropropane instead of air within the microsphere, its duration of action is increased.

METHODS

Each patient received ALBUNEX (0.8 and 0.22 mL/kg) and OPTISON (0.2, 0.5, 3.0, and 5.0 mL) on separate days a minimum of 48 hours apart. Echocardiograms were evaluated for increase in left ventricular (LV) endocardial border length, degree of LV opacification, number of LV endocardial border segments visualized, conversion from a nondiagnostic to a diagnostic echocardiogram, and duration of contrast enhancement. A thorough safety evaluation was conducted.

RESULTS

Compared with ALBUNEX, OPTISON more significantly improved every measure of contrast enhancement. OPTISON increased well-visualized LV endocardial border length by 6.0+/-5.1, 6.9+/-5.4, 7.5+/-4.7, and 7.6+/-4.8 cm, respectively, for each of the four doses, compared with only 2.2+/-4.5 and 3.4+/-4.6 cm, respectively, for the two ALBUNEX doses (p < 0.001). 100% LV opacification was achieved in 61%, 73%, 87%, and 87% of the patients with the four doses of OPTISON, but in only 16% and 36% of the patients with the two ALBUNEX doses (p < 0.001). Conversion of nondiagnostic to diagnostic echocardiograms with contrast occurred in 74% of patients with the optimal dose of OPTISON (3.0 mL) compared with only 26% with the optimal dose of ALBUNEX (0.22 mL/kg) (p < 0.001). The duration of contrast effect was also significantly greater with OPTISON than with ALBUNEX. In a subset of patients with potentially poor transpulmonary transit of contrast (patients with chronic lung disease or dilated cardiomyopathy), OPTISON more significantly improved the same measures of contrast enhancement compared with ALBUNEX and did so to the same extent as in the overall population. Side effects were similar and transient with the two agents.

CONCLUSION

OPTISON appears to be a safe, well-tolerated echocardiographic contrast agent that is superior to ALBUNEX.

Pain control following elective gastrointestinal surgery: is epidural anesthesia warranted?

Fifty-nine patients undergoing elective major gastrointestinal surgery were entered into a prospective, randomized trial between January 1993 and July 1994 comparing the effectiveness, side effects, and hospital costs of postoperative epidural anesthesia (Group 1, n = 29) and intramuscular narcotic injections (Group 2, n = 30). Epidural catheters were inserted by a team that supervised catheter care and infusion rates in the postoperative period. The nonepidural group received intramuscular injections on a regular basis. Patients filled out visual analog scales to measure levels of pain ( 1 = minimal, 10 = maximal) every eight hours. Patient activity, bowel, and urinary function were recorded by the nursing staff. Control of pain (as measured by the daily average visual analog score) was more effective in Group 1 (P < .001) on postoperative days 1-3 (1.3 vs 3.6 on day 1, 0.7 vs 2.6 on day 2, 0.9 vs 3 on day 3). There was no significant difference in mean values between groups 1 and 2 with respect to first ambulation on the hospital ward, onset of liquid diet, intake of solid food, first spontaneous voiding, first bowel movement, length of hospitalization, or charge of hospitalization ($13,439 +/- 7,452 vs $11,821 +/- 6,630). We conclude that epidural anesthesia significantly lessens incisional pain following major elective lower gastrointestinal surgery when compared to analgesic injections alone. However, while not statistically significant, the overall charge was increased by 14% in the epidural group. This finding should be examined in light of the relatively low pain level in patients receiving narcotic injections alone.

Hir proteins are required for position-dependent gene silencing in Saccharomyces cerevisiae in the absence of chromatin assembly factor I

Chromatin assembly factor I (CAF-I) is a three-subunit histone-binding complex conserved from the yeast Saccharomyces cerevisiae to humans. Yeast cells lacking CAF-I (cacDelta mutants) have defects in heterochromatic gene silencing. In this study, we showed that deletion of HIR genes, which regulate histone gene expression, synergistically reduced gene silencing at telomeres and at the HM loci in cacDelta mutants, although hirDelta mutants had no silencing defects when CAF-I was intact. Therefore, Hir proteins are required for an alternative silencing pathway that becomes important in the absence of CAF-I. Because Hir proteins regulate expression of histone genes, we tested the effects of histone gene deletion and overexpression on telomeric silencing and found that alterations in histone H3 and H4 levels or in core histone stoichiometry reduced silencing in cacDelta mutants but not in wild-type cells. We therefore propose that Hir proteins contribute to silencing indirectly via regulation of histone synthesis. However, deletion of combinations of CAC and HIR genes also affected the growth rate and in some cases caused partial temperature sensitivity, suggesting that global aspects of chromosome function may be affected by the loss of members of both gene families.

Phase III multicenter trial comparing the efficacy of 2% dodecafluoropentane emulsion (EchoGen) and sonicated 5% human albumin (Albunex) as ultrasound contrast agents in patients with suboptimal echocardiograms

OBJECTIVES

This study was performed to compare the safety and efficacy of intravenous 2% dodecafluoropentane (DDFP) emulsion (EchoGen) with that of active control (sonicated human albumin [Albunex]) for left ventricular (LV) cavity opacification in adult patients with a suboptimal echocardiogram.

BACKGROUND

The development of new fluorocarbon-based echocardiographic contrast agents such as DDFP has allowed opacification of the left ventricle after peripheral venous injection. We hypothesized that DDFP was clinically superior to the Food and Drug Administration-approved active control.

METHODS

This was a Phase III, multicenter, single-blind, active controlled trial. Sequential intravenous injections of active control and DDFP were given 30 min apart to 254 patients with a suboptimal echocardiogram, defined as one in which the endocardial borders were not visible in at least two segments in either the apical two- or four-chamber views. Studies were interpreted in blinded manner by two readers and the investigators.

RESULTS

Full or intermediate LV cavity opacification was more frequently observed after DDFP than after active control (78% vs. 31% for reader A; 69% vs. 34% for reader B; 83% vs. 55% for the investigators, p < 0.0001). LV cavity opacification scores were higher with DDFP (2.0 to 2.5 vs. 1.1 to 1.5, p < 0.0001). Endocardial border delineation was improved by DDFP in 88% of patients versus 45% with active control (p < 0.001). Similar improvement was seen for duration of contrast effect, salvage of suboptimal echocardiograms, diagnostic confidence and potential to affect patient management. There was no difference between agents in the number of patients with adverse events attributed to the test agent (9% for DDFP vs. 6% for active control, p = 0.92).

CONCLUSIONS

This Phase III multicenter trial demonstrates that DDFP is superior to sonicated human albumin for LV cavity opacification, endocardial border definition, duration of effect, salvage of suboptimal echocardiograms, diagnostic confidence and potential to influence patient management. The two agents had similar safety profiles.

Effects of practice setting on quality of lipid-lowering management in patients with coronary artery disease

We undertook a study to determine whether there were differences in the quality of lipid management in patients with coronary artery disease (CAD) in 2 different practice settings (which represent different socioeconomic classes), and to determine the level of compliance with the National Cholesterol Education Program guidelines by academic physicians in managing patients with CAD. A retrospective cross-sectional study was performed using a systematic chart review of 270 medical records (131 from the cardiology clinic, 139 from the cardiology private practice) of patients with known CAD at an academic tertiary care center in New York City. The total proportion of patients with CAD having a lipid profile ordered in the clinic and private suite was 43%. Of these people, 22% had a low-density lipoprotein cholesterol (LDL) < or = 100 mg/dl and 54% had an LDL < or = 130 mg/dl (10% and 23% of the total population, respectively). The total proportion of patients taking lipid-lowering medications was 29%. When comparing the quality of treatment between the 2 settings, there were no statistically significant differences in the percentages of patients who had lipid profiles measured (40% clinic vs 47% private suite, p >0.10), in the percentage of patients with LDL < or = 130 mg/dl (50% clinic vs 57% private suite, p >0.10) or in the weighted percentage of patients taking lipid-lowering medications (29% clinic vs 48% private suite, p = 0.099). The performances of individual physicians, however, varied widely. The percentages of patients with lipid profiles measured by individual physicians ranged from 0% to 83%, while the percentages of patients on drug treatment by a physician ranged between 10% and 88%. These findings indicate that socioeconomic differences, represented by different practice settings, do not account for differences in the screening for, control of, or use of medications in managing hyperlipidemia. Rather, individual physicians are accountable for differences in lipid management.

Three populations of mouse lymph node dendritic cells with different origins and dynamics

We have identified three distinct populations of mouse lymph node dendritic cells (DC) that differ in their capacity to uptake Ag delivered by different routes, and in their dynamics. The "I-DCs" are large cells that resemble the interdigitating cells and have a mature phenotype and a slow turnover. They derive from the regional tissues. The "sm-DCs" and "sI-DCs" are smaller (hence s-DC), have a more immature phenotype and a rapid turnover. The sI-DC phenotype, including CD8alpha expression suggests a lymphoid-related origin. The sI-DC population is expanded 100-fold after an in vivo flt3 ligand treatment. The sm-DC phenotype suggests a myeloid-related origin. Interestingly, sm-DCs can acquire i.v. injected macromolecules in less than 30 min after injection. They may, therefore, play an important role in the immune response against blood Ags.

Safety and efficacy of closed-loop arbutamine stress echocardiography for detection of coronary artery disease. International Arbutamine Study Group

Closed-loop arbutamine stress echocardiography has been shown to be safe and effective for detecting coronary artery disease (CAD) using a standardized infusion protocol and centralized core laboratory analyses. However, the accuracy of arbutamine stress echocardiography using local test interpretation has not been previously tested in a large population. The present study reports the safety, sensitivity, and specificity of arbutamine stress echocardiography in a multicenter trial allowing user-defined, nonstandardized protocols and local test interpretation. In all, 1,070 patients underwent arbutamine stress testing at 81 sites. Heart rate increased from 73 +/- 13 to 124 +/- 15 beats/min, systolic blood pressure from 144 +/- 24 to 174 +/- 25 mm Hg, and pressure rate product x 10(3) from 10.5 +/- 2.8 to 19.6 +/- 3.9. Among 1,070 patients, there were only 2 (0.2%) significant adverse events related to arbutamine, both of which resolved completely with appropriate therapy. There were no incidents of ventricular fibrillation, sustained ventricular tachycardia, or death related to testing. Among 242 patients who underwent arbutamine stress echocardiography and diagnostic coronary angiography within 12 weeks, sensitivity and specificity for detection of CAD were 71% (95% confidence interval 64% to 77%) and 67% (95% confidence interval 52% to 80%), respectively. Closed-loop arbutamine stress echocardiography is a safe and effective method for evaluating CAD in clinical practice.

Position-dependent variegation of a CD4 minigene with targeted expression to mature CD4+ T cells

The CD4 gene follows a complex and highly regulated pattern of expression throughout T cell development. This expression is governed by different regulatory elements that have been partly identified, including a promoter, a proximal enhancer, and a silencer. Here we show that a CD4 minigene comprising a combination of these elements is specifically expressed in mature CD4+ T cells of transgenic mice, but not in CD4+CD8+ double positive thymocytes. The proportion of transgene-expressing CD4+ T cells was constant within a given transgenic line, but varied greatly from one line to another. We demonstrate that this pattern of expression is due to integration of the transgene within or in the vicinity of centromeric heterochromatin. This position-effect variegation demonstrated with a short CD4 transgene has not been observed with larger ones containing additional regulatory sequences, suggesting that the CD4 gene contains a locus control region. Such position-dependent effects must be taken into consideration when developing transgenic models or gene transfer vectors because they can result in the absence of transgene expression in a subpopulation of target cells. Finally, the combination of the CD4 gene silencer, proximal enhancer, and promoter provides an interesting tool to selectively express genes of interest in mature CD4+ T cells of transgenic mice and for the development of gene therapy vectors.

Position-dependent variegation of a CD4 minigene with targeted expression to mature CD4+ T cells

The CD4 gene follows a complex and highly regulated pattern of expression throughout T cell development. This expression is governed by different regulatory elements that have been partly identified, including a promoter, a proximal enhancer, and a silencer. Here we show that a CD4 minigene comprising a combination of these elements is specifically expressed in mature CD4+ T cells of transgenic mice, but not in CD4+CD8+ double positive thymocytes. The proportion of transgene-expressing CD4+ T cells was constant within a given transgenic line, but varied greatly from one line to another. We demonstrate that this pattern of expression is due to integration of the transgene within or in the vicinity of centromeric heterochromatin. This position-effect variegation demonstrated with a short CD4 transgene has not been observed with larger ones containing additional regulatory sequences, suggesting that the CD4 gene contains a locus control region. Such position-dependent effects must be taken into consideration when developing transgenic models or gene transfer vectors because they can result in the absence of transgene expression in a subpopulation of target cells. Finally, the combination of the CD4 gene silencer, proximal enhancer, and promoter provides an interesting tool to selectively express genes of interest in mature CD4+ T cells of transgenic mice and for the development of gene therapy vectors.

Mesenteric angiography for lower gastrointestinal hemorrhage: are there predictors for a positive study?

PURPOSE

Selective mesenteric angiography is an expensive, invasive, diagnostic, and therapeutic tool for lower gastrointestinal hemorrhage. Some institutions have required a positive nuclear medicine bleeding scan before angiography. We have attempted to determine if this is a valid screening test for mesenteric angiography. Are there any other factors to predict which patients are actively bleeding and who will benefit from angiography?

METHODS

All cases of mesenteric angiography for hemorrhage performed during a 12-year period were reviewed.

RESULTS

A total of 131 angiograms were performed during a 12-year period with 45 patients demonstrating active bleeding; 54 patients had a bleeding scan before angiography. A positive bleeding scan did not increase the percentage of positive angiograms. A history of prior gastrointestinal bleeding, transfusions, orthostatic hypotension, or tachycardia were not predictors for a positive angiogram.

DISCUSSION

This study could not identify any single useful predictor that will increase the likelihood of obtaining a positive angiogram. Nuclear medicine scans should not be used routinely as a screening test for angiography.

Ruptured visceral artery aneurysms

Visceral artery aneurysms are uncommon lesions that are rarely identified in the absence of symptoms. Between February 1972 and April 1992, nine patients (5 men and 4 women) with rupture of visceral artery aneurysms were treated. The average age was 62 years old (range 39 to 86 years old). The arteries involved were the splenic (4), the common hepatic (2), the left hepatic (1), the celiac (1), and the superior mesenteric (SMA) (1). No ruptured renal artery aneurysm was identified. Six patients presented with abdominal distension, pain, and hemodynamic instability. Three patients had recurrent gastrointestinal bleeding with erosion into the duodenum, the common bile duct or the pancreatic duct. All three had unnecessary gastrointestinal operations despite preoperative (2 patients) or intraoperative (1 patient) identification of a visceral artery aneurysm. One patient with an SMA aneurysm had ligation and bypass. Three patients with splenic artery aneurysms had splenectomy. The remaining five patients had either ligation or resection without arterial reconstruction. No end-organ dysfunction was identified. There was one death (11%) due to the SMA aneurysm. Pathological findings in four patients were cystic medial necrosis, diffuse deficiency of the internal elastic lamina, fibromuscular dysplasia, and atherosclerosis, respectively. The remainder were thought to be due to atherosclerosis on gross examination. Rupture of visceral artery aneurysms occurs infrequently and can be treated by simple ligation in most cases. Recognition that rupture of splanchnic arterial aneurysms into adjacent viscera can cause recurrent gastrointestinal bleeding may prevent both substantial delays in diagnosis and inappropriate therapy.