Acute diverticulitis with extraluminal air: is conservative treatment sufficient? A single-center retrospective study

BACKGROUND

Acute diverticulitis with extraluminal air constitutes a heterogeneous condition whose management is controversial. The aims of this study are to report the failure rate of conservative treatment for diverticulitis with extraluminal air and to report risk factors of conservative treatment failure.

METHODS

A retrospective study was performed from an institutional review board-approved database of patients admitted with acute diverticulitis with extraluminal air from 2015 to 2021 at a tertiary referral center. All patients managed for acute diverticulitis with covered perforation (without intraabdominal abscess) were included. The primary endpoint was failure of medical treatment, defined as a need for unplanned surgery or percutaneous drainage within 30 days after admission.

RESULTS

Ninety-three patients (61% male, mean age 57 ± 17 years) were retrospectively included. Ten patients had failure of conservative treatment (11%). These patients were significantly older than 50 years (n = 9/10, 90% versus n = 47/83, 57%, p = 0.007), associated with cardiovascular disease (n = 6/10, 60% versus n = 10/83, 12%, p = 0.002), American Society of Anesthesiologists (ASA) score of 3-4 (n = 4/7, 57% versus 6/33, 18%, p = 0.05), under anticoagulant and antiplatelet (n = 6/10, 60% versus n = 11/83, 13%, p = 0.04) and steroid or immunosuppressive therapy (n = 3/10, 30% versus 5/83, 6%, p = 0.04), and with distant pneumoperitoneum location (n = 7/10, 70% versus n = 14/83, 17%, p = 0.001) compared with those with successful conservative treatment. On multivariate analysis, only distant pneumoperitoneum was an independent risk factor of failure (odds ratio (OR) 6.5, 95% confidence interval (CI) [2-21], p = 0.002).

CONCLUSIONS

Conservative treatment with antibiotics for acute diverticulitis with extraluminal air is safe with a success rate of 89%. Patients with distant pneumoperitoneum should be carefully monitored.

The complex circumstellar environment of supernova 2023ixf

The early evolution of a supernova (SN) can reveal information about the environment and the progenitor star. When a star explodes in vacuum, the first photons to escape from its surface appear as a brief, hours-long shock-breakout flare1,2, followed by a cooling phase of emission. However, for stars exploding within a distribution of dense, optically thick circumstellar material (CSM), the first photons escape from the material beyond the stellar edge and the duration of the initial flare can extend to several days, during which the escaping emission indicates photospheric heating3. Early serendipitous observations2,4 that lacked ultraviolet (UV) data were unable to determine whether the early emission is heating or cooling and hence the nature of the early explosion event. Here we report UV spectra of the nearby SN 2023ixf in the galaxy Messier 101 (M101). Using the UV data as well as a comprehensive set of further multiwavelength observations, we temporally resolve the emergence of the explosion shock from a thick medium heated by the SN emission. We derive a reliable bolometric light curve that indicates that the shock breaks out from a dense layer with a radius substantially larger than typical supergiants.

Infective anoproctitis in men having sex with men: Don't forget Mycoplasma genitalium

OBJECTIVES

The aim was to describe the clinical characteristics of symptomatic anoproctitis and the occurrence of Chlamydia trachomatis (CT), Neisseria gonorrhoeae (NG) and Mycoplasma genitalium (MG) infections in a prospective cohort of MSM patients.

METHODS

From February 2018 to January 2020, all consecutive patients presenting at the Leopold Bellan Proctology Institute of Saint-Joseph Hospital, Paris, France with symptoms of anoproctitis were tested on rectal samples for C. trachomatis (CT), N. gonorrhoeae (NG), M. genitalium (MG). Clinical, microbiological, biological data, STI risk factors, medical history and treatments were collected.

RESULTS

Three hundred and sixty-five patients were included for suspected infective anoproctitis. CT was detected in 84/365 (23%) patients, NG in 45/365 (12%) and MG in 46/315 patients (15%), associated with macrolide resistance in 28/46 MG strains (61%). The most frequent symptoms were rectal pains, rectal bleeding, purulent discharge in 253 (79%), 191 (60%), and 164 (51%) of cases respectively. In comparison with MG infections, ulcerations, erythematous proctitis, rectorragia and false needs were more frequently described in CT infections, while purulent proctitis, functional pain and purulent discharge were more often observed in NG and CT anoproctitis.

CONCLUSION

We found a high prevalence rate of STIs due to CT, NG, while MG detection was associated with a high rate of macrolide resistance in a cohort of MSM patients. Our results confirm that in cases of symptomatic anoproctitis, MG should be tested in association with other STI pathogens.

Liver-Humanized NSG-PiZ Mice Support the Study of Chronic Hepatitis B Virus Infection and Antiviral Therapies

Hepatitis B virus (HBV) is a pathogen of major public health importance that is largely incurable once a chronic infection is established. Only humans and great apes are fully permissive to HBV infection, and this species restriction has impacted HBV research by limiting the utility of small animal models. To combat HBV species restrictions and enable more in vivo studies, liver-humanized mouse models have been developed that are permissive to HBV infection and replication. Unfortunately, these models can be difficult to establish and are expensive commercially, which has limited their academic use. As an alternative mouse model to study HBV, we evaluated liver-humanized NSG-PiZ mice and showed that they are fully permissive to HBV. HBV selectively replicates in human hepatocytes within chimeric livers, and HBV-positive (HBV+) mice secrete infectious virions and hepatitis B surface antigen (HBsAg) into blood while also harboring covalently closed circular DNA (cccDNA). HBV+ mice develop chronic infections lasting at least 169 days, which should enable the study of new curative therapies targeting chronic HBV, and respond to entecavir therapy. Furthermore, HBV+ human hepatocytes in NSG-PiZ mice can be transduced by AAV3b and AAV.LK03 vectors, which should enable the study of gene therapies that target HBV. In summary, our data demonstrate that liver-humanized NSG-PiZ mice can be used as a robust and cost-effective alternative to existing chronic hepatitis B (CHB) models and may enable more academic research labs to study HBV disease pathogenesis and antiviral therapy. IMPORTANCE Liver-humanized mouse models have become the gold standard for the in vivo study of hepatitis B virus (HBV), yet their complexity and cost have prohibited widespread use of existing models in research. Here, we show that the NSG-PiZ liver-humanized mouse model, which is relatively inexpensive and simple to establish, can support chronic HBV infection. Infected mice are fully permissive to hepatitis B, supporting both active replication and spread, and can be used to study novel antiviral therapies. This model is a viable and cost-effective alternative to other liver-humanized mouse models that are used to study HBV.

Adeno-associated virus vectors and neurotoxicity-lessons from preclinical and human studies

Over 15 years after hepatotoxicity was first observed following administration of an adeno-associated virus (AAV) vector during a hemophilia B clinical trial, recent reports of treatment-associated neurotoxicity in animals and humans have brought the potential impact of AAV-associated toxicity back to prominence. In both pre-clinical studies and clinical trials, systemic AAV administration has been associated with neurotoxicity in peripheral nerve ganglia and spinal cord. Neurological signs have also been seen following direct AAV injection into the brain, both in non-human primates and in a clinical trial for late infantile Batten disease. Neurotoxic events appear variable across species, and preclinical animal studies do not fully predict clinical observations. Accumulating data suggest that AAV-associated neurotoxicity may be underdiagnosed and may differ between species in terms of frequency and/or severity. In this review, we discuss the different animal models that have been used to demonstrate AAV-associated neurotoxicity, its potential causes and consequences, and potential approaches to blunt AAV-associated neurotoxicity.

A multiplexed barcode approach to simultaneously evaluate gene delivery by adeno-associated virus capsid variants in nonhuman primates

BACKGROUND AND AIMS

Adeno-associated virus (AAV) vectors are widely used to deliver therapeutic transgenes to distinct tissues, including the liver. Vectors based on naturally occurring AAV serotypes as well as vectors using engineered capsids have shown variations in tissue tropism and level of transduction between different mouse models. Moreover, results obtained in rodents frequently lack translatability into large animal studies. In light of the increasing interest in AAV vectors for human gene therapy, an increasing number of studies are being performed in nonhuman primates. To keep animal numbers to a minimum and thus optimize the process of AAV capsid selection, we developed a multiplex barcoding approach to simultaneously evaluate the in vivo vector performance for a set of serotypes and capsid-engineered AAV vectors across multiple organs.

APPROACH AND RESULTS

Vector biodistribution and transgene expression were assessed by quantitative PCR, quantitative reverse transcription PCR, vector DNA amplicon Illumina sequencing and vRNAseq in male and female rhesus macaques simultaneously dosed with a mixture of barcoded naturally occurring or engineered AAV vectors encoding the same transgene. As expected, our findings show animal-to-animal variation in both the biodistribution and tissue transduction pattern, which was partly influenced by each animal's distinctive serological status.

CONCLUSIONS

This method offers a robust approach to AAV vector optimization that can be used to identify and validate AAV vectors for gene delivery to potentially any anatomical site or cell type.

Epidemiology of symptomatic infective anoproctitis in a population of men having sex with men (MSM)

PURPOSE

Anoproctitis due to Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) are Sexual Transmitted Infections (STIs) reported in MSM population. This study describes clinical and microbiological epidemiology of infective anoproctitis in MSM population.

METHODS

All patients with symptomatic anoproctitis consulting at the proctology Institute of Saint-Joseph's Hospital, Paris, were included. Detection of CT/NG was performed by PCR GeneXpert^R and other STIs pathogens Mycoplasma sp., HSV, CMV and T. pallidum were detected by multiplex PCR Allplex (mPCR).

RESULTS

Symptoms most frequently reported were pain, rectal bleeding and purulent flow in 66%, 52% and 49% of cases, respectively. On the 311 rectal samples collected, 171 (55.2%) were positive to CT/NG. Among the 194 used for mPCR, 148 were positive to STIs pathogens (76.2%) including 106 samples (71.6%) positive in coinfections. Among NG infections, 22.6% of the strains were resistant to azithromycin and 26.8% to tetracyclines.

CONCLUSIONS

Anorectal infections in this MSM population showed a high prevalence of not only CT/NG but also other pathogens involved in STIs. The high level of coinfections confirms the requirement of accurate PCR tests to improve diagnosis. This study describing increasing antibiotic resistances for NG strains confirms the updating of international guidelines on antibiotic treatments recommendations.

Hemorrhoidal surgery in patients with IBD: caution is the parent of safety

BACKGROUND

The aim of this study was to evaluate the outcome of hemorrhoidal surgery in patients with inflammatory bowel disease (IBD) undergoing surgery at our center.

METHODS

All adult patients with IBD undergoing hemorrhoidal surgery in our department between November 1, 2013 and July 7, 2020 were included in the study. At the time of surgery, the patients' IBD was in clinical, biological and endoscopic remission, and none of the patients had specific primary anoperineal lesions.

RESULTS

We included 25 patients (48% female) with a mean age 48 years (± 13.1 years). There were 13 cases of CD (52%) and 12 of ulcerative colitis (UC). Pharmacological and instrumental hemorrhoidal treatment had failed in all patients. The CD lesions were exclusively ileal (77%) or ileocolic (23%). The surgical procedures performed for CD were mono-hemorrhoidectomy in three patients (21.4%), tripedicular hemorrhoidectomy in six patients (42.9%), and artery ligations with mucopexy in five patients (35.7%). UC was rectal (16.7%), rectosigmoid (66.7%), or pancolic (16.6%). The surgical procedures performed for UC were a tripedicular hemorrhoidectomy in ten patients (83.3%) and artery ligations with mucopexy in two patients (16.7%). The mean duration of postoperative follow-up was 15.1 months. None of the patients was lost to follow-up. The mean time to wound healing after resection was 71.1 days (± 21 days) for patients with CD and 56.9 days (± 6.7 days) for patients with UC (p = 0.05). Postoperative complications were reported for four patients with CD (28.8%) and two patients with UC (16.7%). There was no suppuration, stenosis, or anal incontinence sequelae.

CONCLUSIONS

Hemorrhoidal surgery resulted in a non-negligible frequency of complications in our series of IBD patients, especially in those with CD. Caution is, therefore, still necessary in this patient population.

The effects of climate change on the Pleistocene rock art of Sulawesi

The equatorial tropics house some of the earliest rock art yet known, and it is weathering at an alarming rate. Here we present evidence for haloclasty (salt crystallisation) from Pleistocene-aged rock art panels at 11 sites in the Maros-Pangkep limestone karsts of southern Sulawesi. We show how quickly rock art panels have degraded in recent decades, contending that climate-catalysed salt efflorescence is responsible for increasing exfoliation of the limestone cave surfaces that house the ~ 45 to 20-thousand-year-old paintings. These artworks are located in the world's most atmospherically dynamic region, the Australasian monsoon domain. The rising frequency and severity of El Niño-induced droughts from anthropogenic climate change (that is, higher ambient temperatures and more consecutive dry days), combined with seasonal moisture injected via monsoonal rains retained as standing water in the rice fields and aquaculture ponds of the region, increasingly provide ideal conditions for evaporation and haloclasty, accelerating rock art deterioration.

Surgical management of the rectocele - An update

Rectocele is defined as a hernia of the rectum with protrusion of the anterior rectal wall through the posterior wall of the vagina. This condition occurs commonly, with an estimated prevalence of 30-50% of women over age 50. The symptomatology that leads to consultation is variable but consists predominantly of anorectal and/or gynecological complaints such as dyschezia, requiring digital disimpaction maneuvers, pelvic heaviness, anal incontinence, or dyspareunia. Rectocele may be isolated or associated with other disorders of pelvic stasis involving cystocele and uterine prolapse. Complementary exams (dynamic imaging and anorectal manometry) are essential before deciding on the surgical management of this condition. The indications for surgical management of rectocele are based on the intensity of symptoms and the resulting deterioration in quality of life, and surgery should be discussed after failure of medical treatment. Different approaches are possible, although there is currently no real consensus in the literature. The initial approach depends on the type of rectocele: if it involves the low or mid rectum or is isolated, an approach from below (transanal, transperineal, or transvaginal approach) can be proposed, while, in the presence of a high rectocele and/or associated with various disorders of pelvic stasis, transabdominal rectopexy is more suitable.

Gene Transfer in Adeno-Associated Virus Seropositive Rhesus Macaques Following Rapamycin Treatment and Subcutaneous Delivery of AAV6, but Not Retargeted AAV6 Vectors

Adeno-associated virus (AAV) vectors such as AAV6, which shows tropism for primary human CD4⁺ T cells in vitro, are being explored for delivery of anti-HIV therapeutic modalities in vivo. However, pre-existing immunity and sequestration in nontarget organs can significantly hinder their performance. To overcome these challenges, we investigated whether immunosuppression would allow gene delivery by AAV6 or targeted AAV6 derivatives in seropositive rhesus macaques. Animals were immune suppressed with rapamycin before intravenous (IV) or subcutaneous (SC) delivery of AAV, and we monitored vector biodistribution, gene transfer, and safety. Macaques received phosphate-buffered saline, AAV6 alone, or an equal dose of AAV6 and an AAV6-55.2 vector retargeted to CD4 through a direct ankyrin repeat protein (DARPin). AAV6 and AAV6-55.2 vector genomes were found in peripheral blood mononuclear cells and most organs up to 28 days postadministration, with the highest levels seen in liver, spleen, lymph nodes (LNs), and muscle, suggesting that retargeting did not prevent vector sequestration. Despite vector genome detection, gene expression from AAV6-55.2 was not detected in any tissue. SC injection of AAV6 facilitated efficient gene expression in muscle adjacent to the injection site, plus low-level gene expression in spleen, LNs, and liver, whereas gene expression following IV injection of AAV6 was predominantly seen in the spleen. AAV vectors were well tolerated, although elevated liver enzymes were detected in three of four AAV-treated animals 14 days after rapamycin withdrawal. One SC-injected animal had muscle inflammation proximal to the injection site, plus detectable T cell responses against transgene and AAV6 capsid at study finish. Overall, our data suggest that rapamycin treatment may offer a possible strategy to express anti-HIV therapeutics such as broadly neutralizing antibodies from muscle. This study provides important safety and efficacy data that will aid study design for future anti-HIV gene therapies.

Gene editing and elimination of latent herpes simplex virus in vivo

We evaluate gene editing of HSV in a well-established mouse model, using adeno-associated virus (AAV)-delivered meganucleases, as a potentially curative approach to treat latent HSV infection. Here we show that AAV-delivered meganucleases, but not CRISPR/Cas9, mediate highly efficient gene editing of HSV, eliminating over 90% of latent virus from superior cervical ganglia. Single-cell RNA sequencing demonstrates that both HSV and individual AAV serotypes are non-randomly distributed among neuronal subsets in ganglia, implying that improved delivery to all neuronal subsets may lead to even more complete elimination of HSV. As predicted, delivery of meganucleases using a triple AAV serotype combination results in the greatest decrease in ganglionic HSV loads. The levels of HSV elimination observed in these studies, if translated to humans, would likely significantly reduce HSV reactivation, shedding, and lesions. Further optimization of meganuclease delivery and activity is likely possible, and may offer a pathway to a cure for HSV infection.

Laser ablation of fistula tract (LAFT) and complex fistula-in-ano: "the ideal indication" is becoming clearer…

BACKGROUND

An initial study enabled us to achieve 60% healing of high transsphincteric fistula-in-ano with laser ablation of fistula tract (LAFT) The purpose of this new study was to investigate other predictors of the success of this technique in the treatment of complex anoperineal fistulas.

METHODS

All patients treated with LAFT in our department between May 2017 and October 2018 were included prospectively. LAFT was used for patients with complex anoperineal fistulas who were at high risk of anal incontinence after fistulotomy. The fistula was considered healed when the internal and external openings were closed and the patient experienced no pain or leakage.

RESULTS

A total of 100 consecutive patients (65 males) with a median age of 43 years (range 22-88 years) were included in the study. Eight patients were lost to follow-up. The fistulas were low (8%) or high (79%) transsphincteric, and suprasphincteric (13%). After a median follow-up of 13.6 months (range 6-23 months), fistula healing was observed in 41 patients (44.6%). On univariate analysis, an anterior location, a narrow internal orifice and administration of less than 400 J of energy were significantly associated with healing. On multivariate analysis, a narrow internal orifice and low energy administration remained significant predictive factors of success [OR 5.08 (1.03-25.03), p = 0.046; OR 2.59 (1.08-6.17), p = 0.032]. No new cases of anal incontinence or any worsening of pre-existing anal incontinence was observed during follow up.

CONCLUSIONS

This study indicates that complex anoperineal fistulas with a narrow internal orifice can be successfully treated with less than 400 J and are ideal for LAFT.

A low-cost paper-based platform for fast and reliable screening of cellular interactions with materials

A paper-based platform was developed and tested for studies on basic cell culture, material biocompatibility, and activity of pharmaceuticals in order to provide a reliable, robust and low-cost cell study platform. It is based upon a paper or paperboard support, with a nanostructured latex coating to provide an enhanced cell growth and sufficient barrier properties. Wetting is limited to regions of interest using a flexographically printed hydrophobic polydimethylsiloxane layer with circular non-print areas. The nanostructured coating can be substituted for another coating of interest, or the regions of interest functionalized with a material to be studied. The platform is fully up-scalable, being produced with roll-to-roll rod coating, flexographic and inkjet printing methods. Results show that the platform efficiency is comparable to multi-well plates in colorimetric assays in three separate studies: a cell culture study, a biocompatibility study, and a drug screening study. The color intensity is quantified by using a common office scanner or an imaging device and the data is analyzed by a custom computer software without the need for expensive screening or analysis equipment.

The optimal indication for FiLaC® is high trans-sphincteric fistula-in-ano: a prospective cohort of 69 consecutive patients

BACKGROUND

The aim of our study was to prospectively evaluate the effectiveness of the Fistula Laser Closure (FiLaC^®) technique in patients at high risk of anal incontinence and to determine the predictors of success and the impact of the procedure on anal continence.

METHODS

A prospective study was conducted on all patients treated with FiLaC^® in our department in May 2016-April 2017, because they were at high risk of anal incontinence after fistulotomy, The fistula was considered healed when the internal and external openings were closed and the patient experienced was no pain or leakage.

RESULTS

A total of 69 consecutive patients (34 males) with a median age of 40 years (33-53 years) were included in the study. One patient was lost to follow up. The fistulas were intersphincteric (3%), low (15%) or high (66%) trans-sphincteric, and suprasphincteric (16%). After a median follow-up period of 6.3 months (4.2-9.3), fistula healing was observed in 31 patients (45.6%). In univariate analysis, high trans-sphincteric fistulas (p = 0.007) and age over 50 years (p = 0.034) were significantly associated with healing. In multivariate analysis, only high trans-sphincteric fistulas were a predictive factor of significant success. No new cases of anal incontinence or any worsening in case of pre-existing anal incontinence were observed during follow-up.

CONCLUSIONS

FiLaC^® is particularly effective in cases of high trans-sphincteric fistulas (60% cure). This technique seems to be the most promising sphincter-saving technique available for this indication.

CRISPR/Cas9 and Genome Editing for Viral Disease-Is Resistance Futile?

Chronic viral infections remain a major public health issue affecting millions of people worldwide. Highly active antiviral treatments have significantly improved prognosis and infection-related morbidity and mortality but have failed to eliminate persistent viral forms. Therefore, new strategies to either eradicate or control these viral reservoirs are paramount to allow patients to stop antiretroviral therapy and realize a cure. Viral genome disruption based on gene editing by programmable endonucleases is one promising curative gene therapy approach. Recent findings on RNA-guided human immunodeficiency virus 1 (HIV-1) genome cleavage by Cas9 and other gene-editing enzymes in latently infected cells have shown high levels of site-specific genome disruption and potent inhibition of virus replication. However, HIV-1 can readily develop resistance to genome editing at a single antiviral target site. Current data suggest that cellular repair associated with DNA double-strand breaks can accelerate the emergence of resistance. On the other hand, a combination antiviral target strategy can exploit the same repair mechanism to functionally cure HIV-1 infection in vitro while avoiding the development of resistance. This perspective summarizes recent findings on the biology of resistance to genome editing and discusses the significance of viral genetic diversity on the application of gene editing strategies toward cure.

In vivo disruption of latent HSV by designer endonuclease therapy

A large portion of the global population carries latent herpes simplex virus (HSV), which can periodically reactivate, resulting in asymptomatic shedding or formation of ulcerative lesions. Current anti-HSV drugs do not eliminate latent virus from sensory neurons where HSV resides, and therefore do not eliminate the risk of transmission or recurrent disease. Here, we report the ability of HSV-specific endonucleases to induce mutations of essential HSV genes both in cultured neurons and in latently infected mice. In neurons, viral genomes are susceptible to endonuclease-mediated mutagenesis, regardless of the time of treatment after HSV infection, suggesting that both HSV lytic and latent forms can be targeted. Mutagenesis frequency after endonuclease exposure can be increased nearly 2-fold by treatment with a histone deacetylase (HDAC) inhibitor. Using a mouse model of latent HSV infection, we demonstrate that a targeted endonuclease can be delivered to viral latency sites via an adeno-associated virus (AAV) vector, where it is able to induce mutation of latent HSV genomes. These data provide the first proof-of-principle to our knowledge for the use of a targeted endonuclease as an antiviral agent to treat an established latent viral infection in vivo.

[Evaluation of adherence to French guidelines concerning the information of the women having a scarred uterus on their mode of delivery]

OBJECTIVE

To evaluate adherence of obstetricians from our maternity to French practice guidelines concerning information to give to pregnant patients with a history of scarred uterus.

MATERIALS AND METHODS

Observational retrospective study performed on medical files from June to August 2014 and concerning women with a scarred uterus that gave live-birth after 37weeks of gestation. Information of patients had to concern the risks of a history of caesarean, the benefits and risks of the various delivery modes.

RESULTS

On 758 deliveries, 77 cases were studied: 48 patients were followed up from the beginning of pregnancy, 23 from the 2nd trimester and 6 were not followed. Among patients followed from the beginning, no data was written on medical file concerning information that should to be given in immediate post-partum, in preconception counseling, and at the beginning of pregnancy about the risks of scarred uterus and the mode of delivery. In the 8th month, information about benefits and risks of the planned delivery mode was noticed in 45% of files.

CONCLUSION

The information that need in theory to be given to the patients with scarred uterus appeared little or insufficiently noticed on medical files; which can be due either to an inaccurate information, or to a lack of transcription of the information nevertheless given. A check-list in obstetrical file would help to systematize the information to provide in scarred uterus patients.

Classical treatment of hemorrhoids

Radical and definitive surgical treatment is indicated in approximately one out of ten patients with hemorrhoidal disease. The Milligan and Morgan hemorrhoidectomy technique is the most widely performed in France: the technique is well-codified and results are satisfactory and durable if the indications and the post-operative follow-up are appropriately respected. Post-operative pain can be adequately controlled.

AAV-mediated delivery of zinc finger nucleases targeting hepatitis B virus inhibits active replication

Despite an existing effective vaccine, hepatitis B virus (HBV) remains a major public health concern. There are effective suppressive therapies for HBV, but they remain expensive and inaccessible to many, and not all patients respond well. Furthermore, HBV can persist as genomic covalently closed circular DNA (cccDNA) that remains in hepatocytes even during otherwise effective therapy and facilitates rebound in patients after treatment has stopped. Therefore, the need for an effective treatment that targets active and persistent HBV infections remains. As a novel approach to treat HBV, we have targeted the HBV genome for disruption to prevent viral reactivation and replication. We generated 3 zinc finger nucleases (ZFNs) that target sequences within the HBV polymerase, core and X genes. Upon the formation of ZFN-induced DNA double strand breaks (DSB), imprecise repair by non-homologous end joining leads to mutations that inactivate HBV genes. We delivered HBV-specific ZFNs using self-complementary adeno-associated virus (scAAV) vectors and tested their anti-HBV activity in HepAD38 cells. HBV-ZFNs efficiently disrupted HBV target sites by inducing site-specific mutations. Cytotoxicity was seen with one of the ZFNs. scAAV-mediated delivery of a ZFN targeting HBV polymerase resulted in complete inhibition of HBV DNA replication and production of infectious HBV virions in HepAD38 cells. This effect was sustained for at least 2 weeks following only a single treatment. Furthermore, high specificity was observed for all ZFNs, as negligible off-target cleavage was seen via high-throughput sequencing of 7 closely matched potential off-target sites. These results show that HBV-targeted ZFNs can efficiently inhibit active HBV replication and suppress the cellular template for HBV persistence, making them promising candidates for eradication therapy.

AAV-mediated delivery of zinc finger nucleases targeting hepatitis B virus inhibits active replication

Despite an existing effective vaccine, hepatitis B virus (HBV) remains a major public health concern. There are effective suppressive therapies for HBV, but they remain expensive and inaccessible to many, and not all patients respond well. Furthermore, HBV can persist as genomic covalently closed circular DNA (cccDNA) that remains in hepatocytes even during otherwise effective therapy and facilitates rebound in patients after treatment has stopped. Therefore, the need for an effective treatment that targets active and persistent HBV infections remains. As a novel approach to treat HBV, we have targeted the HBV genome for disruption to prevent viral reactivation and replication. We generated 3 zinc finger nucleases (ZFNs) that target sequences within the HBV polymerase, core and X genes. Upon the formation of ZFN-induced DNA double strand breaks (DSB), imprecise repair by non-homologous end joining leads to mutations that inactivate HBV genes. We delivered HBV-specific ZFNs using self-complementary adeno-associated virus (scAAV) vectors and tested their anti-HBV activity in HepAD38 cells. HBV-ZFNs efficiently disrupted HBV target sites by inducing site-specific mutations. Cytotoxicity was seen with one of the ZFNs. scAAV-mediated delivery of a ZFN targeting HBV polymerase resulted in complete inhibition of HBV DNA replication and production of infectious HBV virions in HepAD38 cells. This effect was sustained for at least 2 weeks following only a single treatment. Furthermore, high specificity was observed for all ZFNs, as negligible off-target cleavage was seen via high-throughput sequencing of 7 closely matched potential off-target sites. These results show that HBV-targeted ZFNs can efficiently inhibit active HBV replication and suppress the cellular template for HBV persistence, making them promising candidates for eradication therapy.

DNA cleavage enzymes for treatment of persistent viral infections: recent advances and the pathway forward

Treatment for most persistent viral infections consists of palliative drug options rather than curative approaches. This is often because long-lasting viral DNA in infected cells is not affected by current antivirals, providing a source for viral persistence and reactivation. Targeting latent viral DNA itself could therefore provide a basis for novel curative strategies. DNA cleavage enzymes can be used to induce targeted mutagenesis of specific genes, including those of exogenous viruses. Although initial in vitro and even in vivo studies have been carried out using DNA cleavage enzymes targeting various viruses, many questions still remain concerning the feasibility of these strategies as they transition into preclinical research. Here, we review the most recent findings on DNA cleavage enzymes for human viral infections, consider the most relevant animal models for several human viral infections, and address issues regarding safety and enzyme delivery. Results from well-designed in vivo studies will ideally provide answers to the most urgent remaining questions, and allow continued progress toward clinical application.

[A case of mediastinal angiosarcoma]

INTRODUCTION

Mediastinal angiosarcoma is a rare intrathoracic tumour and the therapeutic approach remains poorly codified.

CASE REPORT

We report the case of a 65-year-old female patient presenting with chest pain. Further exploration revealed an anterior mediastinal mass with pericardial invasion. Transthoracic biopsy gave the diagnosis of angiosarcoma. Multimodal treatment with neoadjuvant chemotherapy (doxorubicin 20 mg/m(2), Ifosfamide 2500 mg/m(2), Uromitexan® 2500 mg/m(2)) and surgery followed by adjuvant radiotherapy has led to remission of the tumour that has persisted for 12 months.

CONCLUSION

Systematic recording of such conditions in dedicated registries could contribute to enhance the description of the clinical and pathological characteristics, thus helping define the principles of specific management.

[Current events in vaccination]

The annual meeting of the Infectious Disease Society of America (IDSA) ; which brought together nearly 5000 participants from over 80 countries in Vancouver, Canada, October 21 to 24, 2010 ; provided a review of the influenza (H1N1) 2009 pandemic, evaluated vaccination programmes and presented new vaccines under development. With 12,500 deaths in the United States in 2009-2010, the influenza (H1N1) 2009 pandemic was actually less deadly than the seasonal flu. But it essentially hit the young, and the toll calculated in years of life lost is high. The monovalent vaccines, whether live attenuated or inactivated with or without adjuvants, were well tolerated in toddlers, children, adults and pregnant women. In order to protect infants against pertussis, family members are urged to get their booster shots. The introduction of the 13-valent Pneumococcal conjugated vaccine in the beginning of 2010 may solve - but for how long ? - the problem of serotype replacement, responsible for the re-increasing incidence of invasive Pneumococcal infections observed in countries that had introduced the 7-valent vaccine. The efficacy of a rotavirus vaccine has been confirmed, with a reduction in hospitalization in the United States and a reduction in gastroenteritis-related deaths in Mexico. In the United States, vaccination of pre-adolescents against human papillomavirus (HPV) has not resulted in any specific undesirable effects. Routine vaccination against chicken pox, recommended since 1995, has not had an impact on the evolution of the incidence of shingles. Vaccination against shingles, recommended in the United States for subjects 60 years and over, shows an effectiveness of 55 %, according to a cohort study (Kaiser Permanente, Southern California). Although some propose the development of personalized vaccines according to individual genetic characteristics, the priority remains with increasing vaccine coverage, not only in infants but also in adults and the elderly. Vaccine calendars that cover a whole lifetime should be promoted, since the vaccination of adults and seniors is a determining factor of good health at all ages.

Successful targeting and disruption of an integrated reporter lentivirus using the engineered homing endonuclease Y2 I-AniI

Current antiviral therapy does not cure HIV-infected individuals because the virus establishes lifelong latent infection within long-lived memory T cells as integrated HIV proviral DNA. Here, we report a new therapeutic approach that aims to cure cells of latent HIV infection by rendering latent virus incapable of replication and pathogenesis via targeted cellular mutagenesis of essential viral genes. This is achieved by using a homing endonuclease to introduce DNA double-stranded breaks (dsb) within the integrated proviral DNA, which is followed by triggering of the cellular DNA damage response and error-prone repair. To evaluate this concept, we developed an in vitro culture model of viral latency, consisting of an integrated lentiviral vector with an easily evaluated reporter system to detect targeted mutagenesis events. Using this system, we demonstrate that homing endonucleases can efficiently and selectively target an integrated reporter lentivirus within the cellular genome, leading to mutation in the proviral DNA and loss of reporter gene expression. This new technology offers the possibility of selectively disabling integrated HIV provirus within latently infected cells.

Modelling intercellular communication and its effects on tumour invasion

We present a model aiming at the description of intercellular communication on the invasive character of gliomas. We start from a previous model of ours based on a cellular automaton and develop a new version of it in a three-dimensional geometry. Introducing the hydrodynamic limit of the automaton we obtain a macroscopic model involving a nonlinear diffusion equation. We show that this macroscopic model is quite adequate for the description of realistic situations. Comparison of the simulations with experimental results shows agreement with the finding that the inhibition of intercellular communication (through gap junctions) tends to decrease migration. As an application of our model we estimated the possible increase in life expectancy, due to reduced cell migration mediated by the inhibition of intercellular communication, on patients suffering from gliomas. We find that the obtained increase may amount to a 20% gain in the case of unresectable tumours.

Investigation of transport processes inside karst aquifer by means of STATIS

Environmental data sets are often multidimensional and consequently display complex structure. This article shows the limitations of principal component analysis (PCA) for the study of such three-dimensional (3D) data sets. These limitations can be resolved by the use of the statistical tool STATIS. The inlet (a swallow hole) and the outlet (a spring) of a karst system of the Western Paris basin were sampled during three rain events of various intensities. These 3D geochemical data sets (variables x sites x dates) for a karst system were analyzed by STATIS method to identify hydrological processes. STATIS proceeds in three steps (interstructure, compromise, and intrastructure), which allows us to focus the analysis of hydrologic systems at different temporal and spatial scales. Compromise plane shows that suspended matter and flood are not simultaneous and highlights a rapid flow, characterized by turbidity and phosphate, which represents a point source contamination, and a ground water flow contaminated by nitrate. Intrastructure plane allows us to compare hydrochemical variations between the swallow hole and the spring lead. By this way, hydrological processes such as direct transfer and resuspension of intrakarstic sediments before and after the flood were identified what cannot be realized by comparison of inlet and outlet breakthrough curves. Finally, results obtained from the same data set by STATIS and a coupled study using PCA and normalized hysteresis curves were compared. This comparison shows the efficiency of STATIS at the identification of transport processes and vulnerability of karst system and its potential for hydrological applications.

[Influenza vaccination coverage in asthmatic children in France in 2006-2007]

In France, an annual seasonal influenza vaccination has been recommended since 2000 for patients suffering from chronic respiratory diseases, including asthma. Each year, a free influenza vaccination voucher is sent by the French Public Health Insurance authorities to patients with chronic respiratory disease, including severe asthma. In November 2006, this measure was extended to all asthmatic patients, irrespective of asthma severity. The present paper examines the 2006-2007 influenza vaccination coverage rate in 433 asthmatic children aged six to 17 years (mean age: 9.5 years; male: 61%) who consulted a pediatric pulmonologist between March and September 2007 in eight hospitals throughout France. The influenza vaccination coverage rate was 15.7% for the 2006-2007 season (13.9% for the 2005-2006 season and 10.9% for the 2004-2005 season). General practitioners vaccinated 72.1% of the children. Lack of information (42%) was the most frequently reported reason for non-vaccination. Free vouchers (received by 39.6% of the children) significantly increased the vaccination coverage rate (31% versus 5.9%; p < 0.001). In France, in 2006-2007, the influenza vaccination coverage rate in asthmatic children was far below the national public health objective to achieve for the year 2008 (at least 75%). Concerted action is needed to improve the influenza vaccination coverage rate in asthmatic children.

A model for short- and long-range interactions of migrating tumour cell

We examine the consequences of long-range effects on tumour cell migration. Our starting point are previous results of ours where we have shown that the migration patterns of glioma cells are best interpreted if one assumes attractive interactions between cells. Here we complement the cellular automaton model previously introduced by the assumption of the existence of a chemorepellent produced by the main bulk of large spheroids (in the hypoxic/necrotic areas). Visible effects due to the presence of such a substance can be found in the density profiles of cells migrating out of a single spheroid as well as in the angular distribution of cells coming from two close-lying spheroids. These effects depend crucially on the diffusion speed of the chemorepellent. A comparison of the simulation results to experimental data of Werbowetski et al. allows to draw (tentative) conclusions on the existence of a chemorepellent and its properties.

Low influenza vaccination coverage in asthmatic children in France in 2006-7

In France, annual seasonal influenza vaccination has been recommended since 2000 for patients suffering from chronic respiratory diseases, including asthma. Since 1988, each year from September to December, a free influenza vaccination voucher is sent by the French Public Health Insurance authorities to patients with chronic respiratory disease, including severe asthma. In November 2006, this measure was extended to all asthmatic patients, irrespective of asthma severity. The present paper examines the 2006-7 influenza vaccination coverage rate (VCR) in 433 asthmatic children aged 6 to 17 years (mean age: 9.5 years; male: 61%) who consulted a paediatric pulmonologist between March and September 2007 in eight hospitals throughout France. The influenza VCR was 15.7% for the 2006-7 season (13.9% for the 2005-6 season and 10.9% for the 2004-5 season). General practitioners vaccinated 72.1% of the children. "Lack of information" (42%) was the most frequently reported reason for non-vaccination. Vouchers (received by 39.6% of the children) significantly increased the VCR (31% versus 5.9%; p<0.001). In France, in 2006-7, the influenza VCR in asthmatic children was far below the national public health objective (at least 75% for the year 2008). Concerted action is needed to improve the influenza VCR in asthmatic children.

[Prospective epidemiological study of rotavirus gastroenteritis in Europe (REVEAL study). Results in the French area of the study]

PRIMARY OBJECTIVE

To estimate the incidence of acute gastroenteritis (AGE) and rotavirus acute gastroenteritis (RVAGE) in children less than 5 years of age seeking medical care in primary care, emergency department, and hospital settings.

SECONDARY OBJECTIVES

To compare the clinical profile of RVAGE and non-RVAGE and to describe the distribution of RV serotypes among RVAGE cases.

METHODS

A prospective primary care, emergency ward and hospital-based observational study was conducted during 1 year in a selected city of France with 250,000 inhabitants. Children less than 5 years of age presenting with symptoms of AGE were included. Rotavirus was identified using an Elisa test in stools.

RESULTS

The estimated annual incidence of RVAGE was 1.56% for AGE and 0.87% for RVAGE in hospital, 5.87% for AGE and 2.65% for RVAGE in emergency-wards, 7.39% for AGE and 1.45% for RVAGE in primary care. Total incidence was 14.82% for AGE and 4.96% for RVAGE among children less than 5 years of age. RVAGE were more clinically severe than the AGE: dehydration (26.8% vs. 14.7%, p<0.0001), vomiting 84.9% vs. 60.9%, p<0.0001), fever (74.3% vs. 44.4%, p<0.0001), lethargy (84.9% vs. 70.2%, p<0.0001). G9 serotype was the most frequent serotype encountered (54.7%) during the study period followed by G3 serotype (33.6%) and G2 serotype (7.9%).

CONCLUSION

In this study, RVAGE, caused by serotypes G9 and G3, represented about 1/3 of AGE and were more severe than non-RV AGE with twice as high dehydration rate. These results underline the need for continued promotion on the use of oral rehydration fluids and provide some arguments on the benefits of vaccination against rotavirus and also permanent virological monitoring of circulating serotypes.

A model for glioma cell migration on collagen and astrocytes

We present a model for the migration of glioma cells on substrates of collagen and astrocytes. The model is based on a cellular automaton where the various dynamical effects are introduced through adequate evolution rules. Using our model, we investigate the role of homotype and heterotype gap junction communication and show that it is possible to reproduce the corresponding experimental migration patterns. In particular, we confirm the experimental findings that inhibition of homotype gap junctions favours migration while heterotype inhibition hinders it. Moreover, the effect of heterotype gap junction inhibition dominates that of homotype inhibition.

Flow cytometric detection of activated caspase-3

Apoptosis (programmed cell death) is an active process that plays a critical role in multiple biologic processes from embryologic development, to lymphocyte development and selection, and homeostasis. The two major mechanisms of cell death are referred to as the intrinsic and extrinsic pathways. These pathways lead to a cascade of events that ultimately converge to the activation of an effector enzyme, caspase-3. Caspase-3 is a cysteine protease with aspartic specificity and a well-characterized effector of apoptosis or programmed cell death signaling. The pro-form of caspase-3 (p32 caspase-3) is sequestered as a zymogen, where upon proteolysis at a conserved DEVD sequence, is converted to the active (p17 caspase-3) enzyme capable of disassembling the cell. Cell death can become disregulated under various conditions and multiple disease states (e.g., viral infection, carcinogenesis, and metastasis). Sensitive and reproducible detection of active caspase-3 is critical to advance the understanding of cellular functions and multiple pathologies of various etiologies. Here, we provide two simple and reproducible methods to measure active caspase-3 in multiple cell types and conditions using a flow cytometric-based analysis.

p53 and hTERT determine sensitivity to viral apoptosis

Apoptosis is a potent host defense against microbes. Most viruses have adapted strategies to counteract this response. Herpes simplex virus (HSV) produces a balance between pro- and antiapoptotic processes during infection. When antiapoptotic signals become limiting, infected cells die through HSV-dependent apoptosis (HDAP). Oncogenic pathways were previously implicated in HDAP susceptibility. Here, we exploited our ability to selectively express all, one, or no oncogenes in the well-defined HeLa cell system to dissect the requirements for HDAP. Human papillomavirus E6 and E7 oncogene expression was inhibited by the E2 viral repressor. Sole expression of E6 mediated HDAP sensitization. Next, two known cellular targets of E6 were independently modulated. This demonstrated that E6 sensitizes HeLa cells to HDAP through hTERT and p53. Given the universality of the apoptotic antiviral response, p53 and telomerase regulation will likely be important for counteracting host defenses in many other viral infections.

Herpes simplex virus blocks apoptosis by precluding mitochondrial cytochrome c release independent of caspase activation in infected human epithelial cells

Expression of HSV-1 genes leads to the induction of apoptosis in human epithelial HEp-2 cells but the subsequent synthesis of infected cell protein prevents the process from killing the cells. Thus, viruses unable to produce appropriate prevention factors are apoptotic. We now report that the addition of either a pancaspase inhibitor or caspase-9-specific inhibitor prevented cells infected with an apoptotic HSV-1 virus from undergoing cell death. This result indicated that HSV-1-dependent apoptosis proceeds through the mitochondrial apoptotic pathway. However, the pancaspase inhibitor did not prevent the release of cytochrome c from mitochondria, implying that caspase activation is not required for this induction of cytochrome c release by HSV-1. The release of cytochrome c was first detected at 9 hpi while caspase-9, caspase-3 and PARP processing were detected at 12 hpi. Finally, Bax accumulated at mitochondria during apoptotic, but not wild type HSV-1 infection. Together, these findings indicate that HSV-1 blocks apoptosis by precluding mitochondrial cytochrome c release in a caspase-independent manner and suggest Bax as a target in infected human epithelial cells.

Herpes simplex virus genes Us3, Us5, and Us12 differentially regulate cytotoxic T lymphocyte-induced cytotoxicity

Many viruses, including Herpes Simplex Virus (HSV), have developed strategies to avoid detection by cytotoxic T lymphocytes (CTLs). In this article, we evaluated the role of individual HSV-1 genes in preventing cytolysis and apoptosis, and in decreasing viral yield after CTL exposure of HSV-infected fibroblasts, using viruses deleted for the immune evasion gene Us12 or one of the two antiapoptotic genes Us3 and Us5. To evaluate CTL-mediated apoptosis, we used a flow cytometry assay measuring active caspase-3 in target cells. This assay was more sensitive than the chromium release assay used to evaluate cytolysis, and measured a different aspect of CTL cytotoxicity. Although virus with deletion of Us12 was markedly defective in the ability to prevent lysis of target fibroblasts, it retained most of its ability to protect target fibroblasts from CTL-induced apoptosis. Virus with deletion of Us3 was also defective in the ability to prevent lysis of target fibroblasts, yet such virus protected target fibroblasts from CTL-induced apoptosis as well as wild-type viruses. In contrast, Us5-deleted virus showed defects in the ability to protect target fibroblasts from both cytolysis and apoptosis after CTL attack. In addition, the replication of Us12-deleted virus was reduced compared with wild-type virus in fibroblasts subjected to CTL attack 6 h after infection, but showed equivalent replication when CTL attack occurred later. In contrast, Us3- or Us5-deleted virus showed no measurable defect in their ability to replicate in fibroblasts under CTL attack. Our data suggest that cytolysis, apoptosis, and viral yield do not necessarily correlate in infected cells under CTL attack. Furthermore, the Us3, Us5, and Us12 viral genes each have unique inhibitory effects on the different T lymphocyte cytotoxic effects. Taken together, these results suggest that HSV evasion of cellular immunity is multifacterial and complex, and relies on the partially redundant activities of various individual HSV proteins.

Apoptosis and antigen receptor function in T and B cells following exposure to herpes simplex virus

T cells are an essential component of the immune response against herpes simplex virus (HSV) infection. We previously reported that incubation of T cells with HSV-infected fibroblasts inhibits subsequent T cell antigen receptor signal transduction. In the current study, we found that incubation of T cells with HSV-infected fibroblasts also leads to apoptosis in exposed T cells. Apoptosis was observed in Jurkat cells, a T cell leukemia line, and also in CD4(+) cells isolated from human peripheral blood mononuclear cells. Direct infection of these cells with HSV also resulted in apoptosis. Clinical isolates of both HSV type 1 and 2 induced apoptosis in infected T cells at comparable levels to cells infected with laboratory strains of HSV, suggesting an immune evasion mechanism that may be clinically relevant. Further understanding of these viral immune evasion mechanisms could be exploited for better management of HSV infection.