6 research outputs found
Targeting Hepatitis B Virus with Zinc Finger Nucleases
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
Multi-parametric MRI guided dose escalated radiotherapy for treatment of localized prostate cancer (PCa): Initial toxicity results of a prospective phase II trial
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Background: Multi-parametric MRI (mpMRI) of PCa uses advanced sequences to detect aggressive, high grade and bulky lesions. Given known advantages of hypofractionated radiotherapy (RT) to treat PCa (low a/b ratio), we conducted a phase II trial to escalate a high dose to mpMRI lesion(s) via Image-Guided (IG)-RT/Volumetric Arc Therapy (VMAT)/Stereotactic Body Radiotherapy (SBRT) technology. We present the acute toxicity results of this novel approach. Methods: 22 pts with mpMRI lesion(s) were prospectively treated to a course of IGRT/VMAT to the prostate & seminal vesicle +/- pelvic lymph nodes (PLN) to a dose of 45 Gy in 25 fractions followed by SBRT boost, 18 Gy in 3 fraction to the prostate with a simultaneous integrated boost 21 Gy in 3 fractions (EQD2 = 85.2 Gy using a/b 3 or 93.4 Gy using a/b 1.5) to the mpMRI prostatic lesion(s). Placement of 3 polymer based fiducial markers visible in both CT and MRI for image co-registration and treatment guidance was performed. Genitourinary (GU) and gastrointestinal (GI) adverse events (AE) were scored using CTCAE v4. DSMC approved reporting of acute AE results prior to completion of trial accrual as an interim safety assessment prior to final trial accrual. Results: Median age was 66.5 years (range: 57-80). All patients had PI-RADS grade 3-5 mpMRI lesion(s); 41.0%, 45.4% and 13.6% having 1, 2 and 3 lesions respectively. Ten (45%) pts had Gleason Score (GS) 8-10 and 12 had GS 7 disease. Median PSA was 8.97 (range: 4.0-77.9). Eleven (50%), 10 (46%), and 1 (5%) pts had stage T1, T2, and T3 tumor, respectively. Nine pts received treatment to the PLN and 15 received androgen deprivation therapy. All patients completed the protocol treatment without reporting acute GI or GU AEs grade ≥3 during treatment or at follow up. Grade 2 GI (diarrhea) and GU toxicity (frequency) was seen in 2 (9%) and 9 (41%) pts, respectively, during treatment. Of the 16 pts (71%) with least 3 months follow-up all grade 2 GI and 55.5% GU toxicities had resolved. Conclusions: Early results of this prospective Phase II study suggest that high-dose RT for localized PCa via mpMRI-guided RT/VMAT and SBRT boost is tolerable with a favorable acute toxicity profile
Reflechi twòp—Thinking Too Much: Description of a Cultural Syndrome in Haiti’s Central Plateau
A rich Haitian ethnopsychology has been described, detailing concepts of personhood, explanatory models of illness, and links between mind and body. However, little research has engaged explicitly with mental illness, and that which does focuses on the Kreyòl term fou (madness), a term that psychiatrists associate with schizophrenia and other psychoses. More work is needed to characterize potential forms of mild-to-moderate mental illness. Idioms of distress provide a promising avenue for exploring common mental disorders. Working in Haiti\u27s Central Plateau, we aimed to identify idioms of distress that represent cultural syndromes. We used ethnographic and epidemiologic methods to explore the idiom of distress reflechi twòp (thinking too much). This syndrome is characterized by troubled rumination at the intersection of sadness, severe mental disorder, suicide, and social and structural hardship. Persons with thinking too much have greater scores on the Beck Depression Inventory and Beck Anxiety Inventory. Thinking too much is associated with 8 times greater odds of suicidal ideation. Untreated thinking too much is sometimes perceived to lead to psychosis. Recognizing and understanding thinking too much may allow early clinical recognition and interventions to reduce long-term psychosocial suffering in Haiti\u27s Central Plateau