Prostate Cancer-related Events in Patients with Synchronous Metastatic Hormone-sensitive Prostate Cancer Treated with Androgen Deprivation Therapy with and Without Concurrent Radiation Therapy to the Prostate; Data from the HORRAD Trial.

BACKGROUND AND OBJECTIVE: A survival benefit was demonstrated for patients with low-volume synchronous metastatic hormone-sensitive prostate cancer (mHSPCa) when local radiotherapy to the prostate was added to androgen deprivation therapy. This study aims to determine the incidence of prostate cancer-related events and treatments in those who received and those who did not receive external beam radiotherapy for mHSPCa. METHODS: The HORRAD trial is a multicentre randomised controlled trial recruiting originally 432 patients with mHSPCa diagnosed between 2004 and 2014. In a second updated analysis, 328 patients were studied retrospectively for local and nonlocal prostate cancer-related events and treatments. Outcome measurements included the incidence and treatment of local (bladder outlet or ureter obstruction, catheterisation, surgical intervention, ureteric stents, and nephrostomy tubes) and nonlocal (blood transfusions, hospitalisations, and treatment for painful bone metastases) events. Differences between groups were compared using crude and adjusted logistic regression, while time to occurrence of local events was assessed with Kaplan-Meier curves and Cox regression analysis. KEY FINDINGS AND LIMITATIONS: A significant difference in the incidence of local events was observed: 30 events in the radiotherapy group versus 50 in the nonradiotherapy group (p = 0.04). Time to occurrence of local interventions was significantly longer in the radiotherapy group (hazard ratio 0.61, 95% confidence interval 0.37-0.99, p = 0.04). The study's limitations include its retrospective nature. CONCLUSIONS AND CLINICAL IMPLICATIONS: Local radiotherapy to the prostate prolongs local event-free survival significantly and reduces local prostate cancer-related interventions in patients with mHSPCa.

Short-term Changes in Health-related Quality of Life of Patients Undergoing Radical Surgery for Upper Urinary Tract Urothelial Carcinoma: Results from a Prospective Phase 2 Clinical Trial.

Background and objective: The possible negative impact of radical surgery on patients' health-related quality of life (HRQoL) plays an important role in preoperative counseling. Here, we analyzed the HRQoL of patients treated for upper urinary tract urothelial carcinoma (UTUC) in the context of a single-arm phase 2 multicenter study, in which the safety and efficacy of a single preoperative intravesical instillation with mitomycin C were investigated. Our objective was to investigate early changes in HRQoL in patients undergoing radical surgery for UTUC and identify factors associated with these outcomes. Methods: Patients with pTanyN0-1M0 UTUC were prospectively included. HRQoL was assessed using the European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire C30 (EORTC QLQ-C30) questionnaire at baseline, and at 1 and 3 mo after surgery. A linear mixed model was used to evaluate the changes in HRQoL over time and identify the variables associated with these outcomes. The clinical effect size was used to assess the clinical impact and level of perceptibility of HRQoL changes for clinicians and/or patients based on given thresholds. Key findings and limitations: Between 2017 and 2020, 186 patients were included. At baseline, 1 mo after surgery, and 3 mo after surgery, response rates were 91%, 84%, and 78%, respectively. One month after surgery, a statistically significant and clinically relevant deterioration was observed in physical, role, and social functioning, and for the included symptom scales: constipation, fatigue, and pain. An improvement in emotional functioning was observed. At 3 mo, HRQoL returned to baseline levels, except emotional functioning, which improved at 1 mo and persisted to be better than that before surgery. Age >70 yr was associated with worse physical functioning, but better social and emotional functioning. Male patients reported better emotional functioning than females. Postoperative complications were negatively associated with social functioning. Conclusions and clinical implications: UTUC patients treated with radical surgery experienced a significant, albeit temporary, decline in HRQoL. Three months following surgery, HRQoL outcomes returned to baseline levels. This information can be used to counsel UTUC patients before undergoing radical surgery and contextualize recovery after surgery. Patient summary: We investigated the changes in quality of life as reported by patients who underwent surgery for upper tract urothelial carcinoma (UTUC). We found that patients experienced a decline in quality of life 1 mo after surgery, but this was temporary, with full recovery of quality of life 3 mo after surgery. These findings can help doctors and other medical staff in counseling UTUC patients before undergoing radical surgery.

Resistance Exercise Training Increases Muscle Mass and Strength in Prostate Cancer Patients on Androgen Deprivation Therapy.

PURPOSE: This study aimed to assess the effects of 20 wk resistance exercise training with or without protein supplementation on body composition, muscle mass, muscle strength, physical performance, and aerobic capacity in prostate cancer patients receiving androgen deprivation therapy (ADT). METHODS: Sixty prostate cancer patients receiving ADT were randomly assigned to perform 20 wk of resistance exercise training with supplementation of 31 g whey protein (EX + PRO, n = 30) or placebo (EX + PLA, n = 30), consumed immediately after exercise and every night before sleep. A separate control group (CON, n = 36) only received usual care. At baseline and after 20 wk, body composition (dual-energy x-ray absorptiometry), muscle mass (computed tomography scan), muscle strength (1-repetition maximum strength tests), physical performance (Timed Up and Go Test, 30-Second Chair Stand Test, and Stair Climb Test), aerobic capacity (cardiopulmonary exercise test), and habitual dietary intake (food diary) were assessed. Data were analyzed using a two-factor repeated-measures ANOVA. RESULTS: Over time, muscle mass and strength increased in EX + PRO and EX + PLA and decreased in CON. Total fat mass and fat percentage increased in EX + PRO and CON, but not in EX + PLA. Physical performance did not significantly change over time in either group. Aerobic capacity was maintained in EX + PLA, but it decreased in EX + PRO and CON. Habitual protein intake (without supplements) averaged >1.0 g·kg body weight -1 ·d -1 , with no differences over time or between groups. CONCLUSIONS: In prostate cancer patients, resistance exercise training counteracts the adverse effects of ADT on body composition, muscle mass, muscle strength, and aerobic capacity, with no additional benefits of protein supplementation.

Optimization of Preoperative Lymph Node Staging in Patients with Muscle-Invasive Bladder Cancer Using Radiomics on Computed Tomography.

Approximately 25% of the patients with muscle-invasive bladder cancer (MIBC) who are clinically node negative have occult lymph node metastases at radical cystectomy (RC) and pelvic lymph node dissection. The aim of this study was to evaluate preoperative CT-based radiomics to differentiate between pN+ and pN0 disease in patients with clinical stage cT2-T4aN0-N1M0 MIBC. Patients with cT2-T4aN0-N1M0 MIBC, of whom preoperative CT scans and pathology reports were available, were included from the prospective, multicenter CirGuidance trial. After manual segmentation of the lymph nodes, 564 radiomics features were extracted. A combination of different machine-learning methods was used to develop various decision models to differentiate between patients with pN+ and pN0 disease. A total of 209 patients (159 pN0; 50 pN+) were included, with a total of 3153 segmented lymph nodes. None of the individual radiomics features showed significant differences between pN+ and pN0 disease, and none of the radiomics models performed substantially better than random guessing. Hence, CT-based radiomics does not contribute to differentiation between pN+ and pN0 disease in patients with cT2-T4aN0-N1M0 MIBC.

Long-term Follow-up of Intravesical Onabotulinum Toxin-A Injections in Male Patients with Idiopathic Overactive Bladder: Comparing Surgery-naïve Patients and Patients After Prostate Surgery.

BACKGROUND: Evidence regarding long-term results in male idiopathic overactive bladder (iOAB) patients is limited and rarely focuses on the effects of prior prostatic surgery. OBJECTIVE: This study aims to identify the long-term treatment persistency and occurrence of adverse events of intravesical onabotulinum toxin-A (BoNT-A) injections in male iOAB patients after prostatic surgery (ie, transurethral resection of the prostate [TURP] or radical prostatectomy [RP]) compared with surgery-naïve patients. DESIGN, SETTING, AND PARTICIPANTS: In this retrospective, single-centre study, data from 477 patients treated with intravesical BoNT-A injections were collected. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Outcome data of 120 male patients with iOAB, with collectively 207 BoNT-A injections, were analysed and presented in this study. RESULTS AND LIMITATIONS: At the last point of follow-up, 35 patients (29.2%) were still on active treatment. Twenty patients (16.7%) required de novo clean intermittent self-catheterisation (CISC). Three groups were identified: 56 patients without prostate surgery, 40 patients with TURP, and 24 patients with RP prior to treatment. Discontinuation rates and patient-reported outcomes of BoNT-A treatment (none, insufficient, or satisfactory) were similar, but a significant difference was seen in de novo CISC (p=0.004): 28.6% in the group without prior surgery, 7.5% in the TURP subgroup, and 4.2% in the RP subgroup. Odds of de novo CISC was significantly higher for the group without prior surgery than for both the TURP subgroup (odds ratio [OR] 4.9; 95% confidence interval [CI]: 1.33-18.31; p=0.017) and the RP subgroup (OR 9.2; 95% CI: 1.14-73.96; p= 0.037). CONCLUSIONS: The data of this retrospective, single-centre cohort suggest that BoNT-A treatment leads to lower CISC rates in male patients after prior desobstructive surgery than in surgery-naïve patients. PATIENT SUMMARY: This study describes the results of onabotulinum toxin-A (BoNT-A) injections in the bladder of male patients with idiopathic overactive bladder after initial prostate surgery compared with surgery-naïve patients. The results showed that BoNT-A treatment leads to lower catheterisation rates in patients after prior prostate surgery than in men without prior prostate surgery.

Patient-reported Quality of Life in Patients with Primary Metastatic Prostate Cancer Treated with Androgen Deprivation Therapy with and Without Concurrent Radiation Therapy to the Prostate in a Prospective Randomised Clinical Trial; Data from the HORRAD Trial.

BACKGROUND: A survival benefit was demonstrated for patients with low-volume metastatic prostate cancer (mPCa) when local radiotherapy was added to androgen deprivation therapy (ADT). OBJECTIVE: To determine the effect of ADT combined with external beam radiotherapy (EBRT) to the prostate on health-related quality of life (HRQoL) of patients with primary bone mPCa. DESIGN, SETTING, AND PARTICIPANTS: The HORRAD trial is a multicentre randomised controlled trial recruiting 432patients with primary bone mPCa between 2004 and 2014. INTERVENTION: Patients were randomised to ADT with EBRT or to ADT alone. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Patients completed two validated HRQoL questionnaires (European Organization for Research and Treatment of Cancer [EORTC] Quality of Life Questionnaire Core Module (QLQ-C30) and EORTC Quality of Life Questionnaire Prostate Module [QLQ-PR25]) at baseline and at 3, 6, 12, and24 mo after the initiation of treatment. The effect of both treatments was evaluated based on mixed-effect models. RESULTS AND LIMITATIONS: Patient characteristics and HRQoL scores at baseline were similar in both arms. At baseline, 98% of patients completed the questionnaires, compared with 58% at 24 mo. Patients reported significantly more diarrhoea (difference between the groups 10.8; 95% confidence interval [CI] 7.3-14.2), bowel symptoms (4.5; 95% CI 2.1-6.8), and urinary symptoms (11.9; 95% CI 8.9-14.8) after EBRT and ADT compared with ADT alone (all between-arm difference p < 0.001). Urinary complaints levelled at 6 mo. At 2 yr, only bowel symptom scores were significantly different (8.0; 95% CI 4.8-11.1, p ≤ 0.001), but 68% of patients in the radiotherapy group did not report clinically relevant worsening of their bowel symptom scores. CONCLUSIONS: Patients with bone mPCa reported temporary modest urinary and bowel symptoms after combined treatment with EBRT of the prostate and ADT compared with ADT alone. For some patients (22%), deterioration of bowel functions remains at 2 yr, whereas general HRQoL does not deteriorate.. PATIENT SUMMARY: This study investigated the effect of radiotherapy to the prostate added to hormonal therapy on patient-reported health-related quality of life (HRQoL) in patients with primary bone metastatic prostate cancer. Most patients reported only temporary urinary and bowel symptoms. In 22% of patients, bowel symptoms remained at 2 yr, whereas general HRQoL did not deteriorate.

[Chloroquine as a possible treatment for COVID-19]. / Chloroquine als mogelijke behandeling van COVID-19.

Since the outbreak of COVID-19, chloroquine has been mentioned as a possible treatment. In vitro studies have shown anti-viral activity of chloroquine against SARS-CoV-2. Recently, the Dutch National Institute for Public Health and the Environment published treatment options for antiviral treatment for COVID-19 where chloroquine was suggested as first choice for off-label treatment, beside remdesivir en lopinavir/ritonavir. In this commentary, we provide a background and history of chloroquine, the evidence for antiviral efficacy of chloroquine and the arguments for off-label use of chloroquine in COVID-19.

Preclinical Activity of HER2-Selective Tyrosine Kinase Inhibitor Tucatinib as a Single Agent or in Combination with Trastuzumab or Docetaxel in Solid Tumor Models.

HER2 is a transmembrane tyrosine kinase receptor that mediates cell growth, differentiation, and survival. HER2 is overexpressed in approximately 20% of breast cancers and in subsets of gastric, colorectal, and esophageal cancers. Both antibody and small-molecule drugs that target HER2 and block its tyrosine kinase activity are effective in treating HER2-driven cancers. In this article, we describe the preclinical properties of tucatinib, an orally available, reversible HER2-targeted small-molecule tyrosine kinase inhibitor. In both biochemical and cell signaling experiments, tucatinib inhibits HER2 kinase activity with single-digit nanomolar potency and provides exceptional selectivity for HER2 compared with the related receptor tyrosine kinase EGFR, with a >1,000-fold enhancement in potency for HER2 in cell signaling assays. Tucatinib potently inhibits signal transduction downstream of HER2 and HER3 through the MAPK and PI3K/AKT pathways and is selectively cytotoxic in HER2-amplified breast cancer cell lines in vitro. In vivo, tucatinib is active in multiple HER2+ tumor models as a single agent and shows enhanced antitumor activity in combination with trastuzumab or docetaxel, resulting in improved rates of partial and complete tumor regression. These preclinical data, taken together with the phase-I tucatinib clinical trial results demonstrating preliminary safety and activity, establish the unique pharmacologic properties of tucatinib and underscore the rationale for investigating its utility in HER2+ cancers. GRAPHICAL ABSTRACT: http://mct.aacrjournals.org/content/molcanther/19/4/976/F1.large.jpg.

Author Correction: Discovery of a selective catalytic p300/CBP inhibitor that targets lineage-specific tumours.

In the originally published version of this Letter, the authors Arthur F. Kluge, Michael A. Patane and Ce Wang were inadvertently omitted from the author list. Their affiliations are: I-to-D, Inc., PO Box 6177, Lincoln, Massachusetts 01773, USA (A.F.K.); Mitobridge, Inc. 1030 Massachusetts Avenue, Cambridge, Massachusetts 02139, USA (M.A.P.); and China Novartis Institutes for BioMedical Research, No. 4218 Jinke Road, Zhangjiang Hi-Tech Park, Pudong District, Shanghai 201203, China (C.W.). These authors contributed to the interpretation of results and design of compounds. In addition, author 'Edward A. Kesicki' was misspelled as 'Ed Kesicki'. These errors have been corrected online.

Discovery of Spiro Oxazolidinediones as Selective, Orally Bioavailable Inhibitors of p300/CBP Histone Acetyltransferases.

p300 and its paralog CBP can acetylate histones and other proteins and have been implicated in a number of diseases characterized by aberrant gene activation, such as cancer. A novel, highly selective, orally bioavailable histone acetyltransferase (HAT) domain inhibitor has been identified through virtual ligand screening and subsequent optimization of a unique hydantoin screening hit. Conformational restraint in the form of a spirocyclization followed by substitution with a urea led to a significant improvement in potency. Replacement of the hydantoin moiety with an oxazolidinedione followed by fluoro substitution led to A-485, which exhibits potent cell activity, low clearance, and high oral bioavailability.

Discovery of a selective catalytic p300/CBP inhibitor that targets lineage-specific tumours.

The dynamic and reversible acetylation of proteins, catalysed by histone acetyltransferases (HATs) and histone deacetylases (HDACs), is a major epigenetic regulatory mechanism of gene transcription and is associated with multiple diseases. Histone deacetylase inhibitors are currently approved to treat certain cancers, but progress on the development of drug-like histone actyltransferase inhibitors has lagged behind. The histone acetyltransferase paralogues p300 and CREB-binding protein (CBP) are key transcriptional co-activators that are essential for a multitude of cellular processes, and have also been implicated in human pathological conditions (including cancer). Current inhibitors of the p300 and CBP histone acetyltransferase domains, including natural products, bi-substrate analogues and the widely used small molecule C646, lack potency or selectivity. Here, we describe A-485, a potent, selective and drug-like catalytic inhibitor of p300 and CBP. We present a high resolution (1.95 Å) co-crystal structure of a small molecule bound to the catalytic active site of p300 and demonstrate that A-485 competes with acetyl coenzyme A (acetyl-CoA). A-485 selectively inhibited proliferation in lineage-specific tumour types, including several haematological malignancies and androgen receptor-positive prostate cancer. A-485 inhibited the androgen receptor transcriptional program in both androgen-sensitive and castration-resistant prostate cancer and inhibited tumour growth in a castration-resistant xenograft model. These results demonstrate the feasibility of using small molecule inhibitors to selectively target the catalytic activity of histone acetyltransferases, which may provide effective treatments for transcriptional activator-driven malignancies and diseases.

Long-term compliance and results of intravesical botulinum toxin A injections in male patients.

INTRODUCTION: Intravesical injections with botulinum toxin A (BoNT-A) is an established treatment for patients with overactive bladder (OAB) symptoms. However, most studies have evaluated the efficacy of this treatment in women and report short-term results. In this study, we evaluated the long-term compliance of BoNT-A in a heterogeneous group of male patients. MATERIALS AND METHODS: This is a retrospective, single-centre study. We evaluated all male patients who have been treated with BoNT-A from 2004 until 2010 in a large teaching hospital. Patients received 100-300 U of onabotulinum toxin-A in 20 intravescial injections. Some patients received dose adjustment with repeated injections. RESULTS: In total, 88 male patients were included. The mean follow-up was almost 6 years (69 months). Of all patients, 22 (25%) continued BoNT-A treatment at last follow-up (success). Of the patients who discontinued treatment, 35 had insufficient effect and 27 had tolerability issues (eg, urinary retention, self-catheterisation, voiding LUTS). Four patients abandoned treatment due to other reasons that were not related to BoNT-A. Of all patients, 24% had to use intermittent catheterisation (de novo) or indwelling catheters at some point during the follow-up. DISCUSSION: In this real-life, heterogeneous cohort of men, the long-term compliance with BoNT-A was 25%. Patients with neurogenic OAB symptoms appear to have the best results in our study with 36% of patients who were still on active treatment during last follow-up. Intravesical BoNT-A can be an effective treatment for men with OAB symptoms. In our study, only 25% of patients continued treatment during long-term follow-up. Larger, prospective trials are needed to confirm these results.

Distal renal tubular acidosis with multiorgan autoimmunity: a case report.

A 61-year-old woman with a history of pernicious anemia presented with progressive muscle weakness and dysarthria. Hypokalemic paralysis (serum potassium, 1.4 mEq/L) due to distal renal tubular acidosis (dRTA) was diagnosed. After excluding several possible causes, dRTA was considered autoimmune. However, the patient did not meet criteria for any of the autoimmune disorders classically associated with dRTA. She had very high antibody titers against parietal cells, intrinsic factor, and thyroid peroxidase (despite normal thyroid function). The patient consented to a kidney biopsy, and acid-base transporters, anion exchanger type 1 (AE1), and pendrin were undetectable by immunofluorescence. Indirect immunofluorescence detected diminished abundance of AE1- and pendrin-expressing intercalated cells in the kidney, as well as staining by the patient's serum of normal human intercalated cells and parietal cells expressing the adenosine triphosphatase hydrogen/potassium pump (H(+)/K(+)-ATPase) in normal human gastric mucosa. The dRTA likely is caused by circulating autoantibodies against intercalated cells, with possible cross-reactivity against structures containing gastric H(+)/K(+)-ATPase. This case demonstrates that in patients with dRTA without a classic autoimmune disorder, autoimmunity may still be the underlying cause. The mechanisms involved in autoantibody development and how dRTA can be caused by highly specific autoantibodies against intercalated cells have yet to be determined.

Systematic review of biomarkers to monitor therapeutic response in leishmaniasis.

Recently, there has been a renewed interest in the development of new drugs for the treatment of leishmaniasis. This has spurred the need for pharmacodynamic markers to monitor and compare therapies specifically for visceral leishmaniasis, in which the primary recrudescence of parasites is a particularly long-term event that remains difficult to predict. We performed a systematic review of studies evaluating biomarkers in human patients with visceral, cutaneous, and post-kala-azar dermal leishmaniasis, which yielded a total of 170 studies in which 53 potential pharmacodynamic biomarkers were identified. In conclusion, the large majority of these biomarkers constituted universal indirect markers of activation and subsequent waning of cellular immunity and therefore lacked specificity. Macrophage-related markers demonstrate favorable sensitivity and times to normalcy, but more evidence is required to establish a link between these markers and clinical outcome. Most promising are the markers directly related to the parasite burden, but future effort should be focused on optimization of molecular or antigenic targets to increase the sensitivity of these markers. In general, future research should focus on the longitudinal evaluation of the pharmacodynamic biomarkers during treatment, with an emphasis on the correlation of studied biomarkers and clinical parameters.

Epstein-Barr virus-positive post-transplant lymphoproliferative disorder of the central nervous system, after renal transplantation with a discrepancy in viral load between peripheral blood and cerebrospinal fluid.

A 43-year-old female developed an Epstein-Barr virus (EBV)-positive post-transplant lymphoproliferative disorder (PTLD) in the central nervous system (CNS), 14 years after renal transplantation. One year prior to presentation, the patients' treatment regimen was altered from cyclosporine, azathioprine, and prednisone to mycophenolate mofetil and prednisone. Magnetic resonance imaging of the brain revealed lesions suspect for malignant lymphoma. The EBV real-time polymerase chain reaction (PCR) on peripheral blood was negative, but highly positive on cerebrospinal fluid. EBV-positive PTLD was confirmed using histological analysis of cerebral biopsies. Despite tapering of immune suppressive medication and treatment with rituximab and chemotherapy, the patient deceased 50 days after presentation. This case illustrates that vigilance is required when presented with a negative EBV PCR result on peripheral blood when PTLD of the CNS is suspected. This late presentation suggests a relation to the switch in immunosuppressive regimen 1 year earlier.

[A woman with a vaginal tumor]. / Een vrouw met een vaginale tumor.

A 87-year-old woman presented with vaginal blood loss. A tumor protruded through the anterior vaginal wall. Biopsy revealed transitional epithelium without atypia. In 1975 the urethra was dilated because of ischuria after a midline cystocele repair resulted in trauma. A post-traumatic transvaginal diverticulum of the urethra was diagnosed and closed.

Miltefosine: a review of its pharmacology and therapeutic efficacy in the treatment of leishmaniasis.

Miltefosine is an alkylphosphocholine drug with demonstrated activity against various parasite species and cancer cells as well as some pathogenic bacteria and fungi. For 10 years it has been licensed in India for the treatment of visceral leishmaniasis (VL), a fatal neglected parasitic disease. It is the first and still the only oral drug that can be used to treat VL and cutaneous leishmaniasis (CL). The standard 28 day miltefosine monotherapy regimen is well tolerated, except for mild gastrointestinal side effects, although its teratogenic potential severely hampers its general use in the clinic and roll-out in national elimination programmes. The pharmacokinetics of miltefosine are mainly characterized by its long residence time in the body, resulting in extensive drug accumulation during treatment and long elimination half-lives. At the moment, different combination therapy strategies encompassing miltefosine are being tested in multiple controlled clinical trials in various geographical areas of endemicity, both in South Asia and East Africa. We here review the most salient pre-clinical and clinical pharmacological aspects of miltefosine, its mechanism of action against Leishmania parasites and other pathogens, and provide a systematic overview of the efficacy and safety data from all clinical trials of miltefosine, either alone or in combination, in the treatment of VL and CL.

High-resolution analysis of intrahost genetic diversity in dengue virus serotype 1 infection identifies mixed infections.

Little is known about the rate at which genetic variation is generated within intrahost populations of dengue virus (DENV) and what implications this diversity has for dengue pathogenesis, disease severity, and host immunity. Previous studies of intrahost DENV variation have used a low frequency of sampling and/or experimental methods that do not fully account for errors generated through amplification and sequencing of viral RNAs. We investigated the extent and pattern of genetic diversity in sequence data in domain III (DIII) of the envelope (E) gene in serial plasma samples (n = 49) taken from 17 patients infected with DENV type 1 (DENV-1), totaling some 8,458 clones. Statistically rigorous approaches were employed to account for artifactual variants resulting from amplification and sequencing, which we suggest have played a major role in previous studies of intrahost genetic variation. Accordingly, nucleotide sequence diversities of viral populations were very low, with conservative estimates of the average levels of genetic diversity ranging from 0 to 0.0013. Despite such sequence conservation, we observed clear evidence for mixed infection, with the presence of multiple phylogenetically distinct lineages present within the same host, while the presence of stop codon mutations in some samples suggests the action of complementation. In contrast to some previous studies we observed no relationship between the extent and pattern of DENV-1 genetic diversity and disease severity, immune status, or level of viremia.

Viral respiratory tract infections among patients with acute undifferentiated fever in Vietnam.

To investigate the proportion of viral respiratory tract infections among acute undifferentiated fevers (AUFs) at primary health facilities in southern Vietnam during 2001-2005, patients with AUF not caused by malaria were enrolled at twelve primary health facilities and a clinic for malaria control program. Serum was collected on first presentation (t0) and after 3 weeks (t3) for serology. After exclusion of acute dengue infection, acute and convalescent serum samples from 606 patients were using enzyme-linked immunoassays to detect IgA, as well as IgM and IgG antibodies against common respiratory viruses. Paired sera showed the following infections: human parainfluenza virus (HPIV, 4.7%), influenza B virus (FLUBV, 2.2%), influenza A virus (FLUAV, 1.9%) and human respiratory syncytial virus (HRSV, 0.6%). There was no association between type of infection and age, sex or seasonality; some inter-annual differences were observed for influenza. Antibody prevalence, indicative of previous infections, was relatively low: HPV, 56.8%, FLUBV, 12.1%; FLUAV, 5.9% and HRSV, 6.8%.

In vitro and in vivo metabolism of paclitaxel poliglumex: identification of metabolites and active proteases.

BACKGROUND: The efficacy and tolerability of paclitaxel is limited by its low solubility, high systemic exposure, and a lack of selective tumor uptake. Paclitaxel poliglumex (PPX; XYOTAX) is a macromolecular drug conjugate that was developed to overcome these limitations; the 2' hydroxyl group of paclitaxel is linked to a biodegradable polymer, poly-L: -glutamic acid, to form an inactive polymeric conjugate. PPX was previously shown to accumulate in tumor tissue, presumably by taking advantage of the hyperpermeable tumor vasculature and suppressed lymphatic clearance in tumor tissue. METHODS: Because anti-tumor activity requires the release of paclitaxel from the polymer-drug conjugate, the current report characterizes PPX biodegradation and release of paclitaxel as determined by quantitative HPLC/mass spectral analysis. RESULTS: The identification of monoglutamyl-paclitaxel metabolites in tumor tissue confirmed the in vivo metabolism of PPX in a panel of mouse tumor models. In vitro characterization of the metabolic pathway suggests that PPX can enter tumor cells, and is metabolized to form both mono- and diglutamyl-paclitaxel cleavage products. The intracellular formation of these intermediate metabolites is at least partially dependent on the proteolytic activity of the lysosomal enzyme cathepsin B; PPX metabolism is inhibited by a highly selective inhibitor of cathepsin B, CA-074. Reduced metabolism of PPX in livers and spleens from cathepsin B deficient mice confirms that cathepsin B is an important mediator of PPX metabolism in vivo; however, other proteolytic enzymes may contribute as well. CONCLUSIONS: The cathepsin B-mediated release of paclitaxel may have therapeutic implications as cathepsin B is upregulated in malignant cells, particularly during tumor progression.