Limited Relationship Between Echocardiographic Measures and Electrocardiographic Markers of Left Ventricular Size in Healthy Children.

Pediatric ECG standards have been defined without echocardiographic confirmation of normal anatomy. The Pediatric Heart Network Normal Echocardiogram Z-score Project provides a racially diverse group of healthy children with normal echocardiograms. We hypothesized that ECG and echocardiographic measures of left ventricular (LV) dimensions are sufficiently correlated in healthy children to imply a clinically meaningful relationship. This was a secondary analysis of a previously described cohort including 2170 digital ECGs. The relationship between 6 ECG measures associated with LV size were analyzed with LV Mass (LVMass-z) and left ventricular end-diastolic volume (LVEDV-z) along with 11 additional parameters. Pearson or Spearman correlations were calculated for the 78 ECG-echocardiographic pairs with regression analyses assessing the variance in ECG measures explained by variation in LV dimensions and demographic variables. ECG/echocardiographic measurement correlations were significant and concordant in 41/78 (53%), though many were significant and discordant (13/78). Of the 6 ECG parameters, 5 correlated in the clinically predicted direction for LV Mass-z and LVEDV-z. Even when statistically significant, correlations were weak (0.05-0.24). R2 was higher for demographic variables than for echocardiographic measures or body surface area in all pairs, but remained weak (R2 ≤ 0.17). In a large cohort of healthy children, there was a positive association between echocardiographic measures of LV size and ECG measures of LVH. These correlations were weak and dependent on factors other than echocardiographic or patient derived variables. Thus, our data support deemphasizing the use of solitary, traditional measurement-based ECG markers traditionally thought to be characteristic of LVH as standalone indications for further cardiac evaluation of LVH in children and adolescents.

Assessing the lack of diversity in genetics research across neurodegenerative diseases: a systematic review of the GWAS Catalog and literature.

Importance: The under-representation of participants with non-European ancestry in genome-wide association studies (GWAS) is a critical issue that has significant implications, including hindering the progress of precision medicine initiatives. This issue is particularly significant in the context of neurodegenerative diseases (NDDs), where current therapeutic approaches have shown limited success. Addressing this under-representation is crucial to harnessing the full potential of genomic medicine in underserved communities and improving outcomes for NDD patients. Objective: Our primary objective was to assess the representation of non-European ancestry participants in genetic discovery efforts related to NDDs. We aimed to quantify the extent of inclusion of diverse ancestry groups in NDD studies and determine the number of associated loci identified in more inclusive studies. Specifically, we sought to highlight the disparities in research efforts and outcomes between studies predominantly involving European ancestry participants and those deliberately targeting non-European or multi-ancestry populations across NDDs. Evidence Review: We conducted a systematic review utilizing existing GWAS results and publications to assess the inclusion of diverse ancestry groups in neurodegeneration and neurogenetics studies. Our search encompassed studies published up to the end of 2022, with a focus on identifying research that deliberately included non-European or multi-ancestry cohorts. We employed rigorous methods for the inclusion of identified articles and quality assessment. Findings: Our review identified a total of 123 NDD GWAS. Strikingly, 82% of these studies predominantly featured participants of European ancestry. Endeavors specifically targeting non-European or multi-ancestry populations across NDDs identified only 52 risk loci. This contrasts with predominantly European studies, which reported over 90 risk loci for a single disease. Encouragingly, over 65% of these discoveries occurred in 2020 or later, indicating a recent increase in studies deliberately including non-European cohorts. Conclusions and relevance: Our findings underscore the pressing need for increased diversity in neurodegenerative research. The significant under-representation of non-European ancestry participants in NDD GWAS limits our understanding of the genetic underpinnings of these diseases. To advance the field of neurodegenerative research and develop more effective therapies, it is imperative that future investigations prioritize and harness the genomic diversity present within and across global populations.

Anakinra-Associated Systemic Amyloidosis.

OBJECTIVE: To describe a 41-year-old woman with a history of neonatal onset multisystem inflammatory disease, on treatment with daily subcutaneous injections of 600 mg of recombinant interleukin-1 receptor antagonist (IL-1Ra) protein, anakinra, since the age of 28, who presented with golf-ball size nodules at the anakinra injection sites, early satiety, new onset nephrotic syndrome in the context of normal markers of systemic inflammation. METHODS: Clinical history and histologic evaluation of biopsies of skin, gastric mucosa, and kidney with Congo-red staining and proteomic evaluation of microdissected Congo red-positive amyloid deposits by liquid chromatography-tandem mass spectrometry. RESULTS: The skin, stomach, and kidney biopsies all showed the presence of Congo red-positive amyloid deposits. Mass spectrometry-based proteomics demonstrated that the amyloid deposits in all sites were of AIL1RAP (IL-1Ra protein)-type. These were characterized by high spectral counts of the amyloid signature proteins (apolipoprotein AIV, apolipoprotein E, and serum amyloid P-component) and the amyloidogenic IL-1Ra protein, which were present in Congo red-positive areas and absent in Congo red-negative areas. The amino acid sequence identified by mass spectrometry confirmed that the amyloid precursor protein was recombinant IL-1Ra (anakinra) and not endogenous wild-type IL-1Ra. CONCLUSION: This is the first report of iatrogenic systemic amyloidosis due to an injectable protein drug, which was caused by recombinant IL1Ra (anakinra).

Evaluation of TERT mRNA expression using RNAscope®: A potential histopathologic diagnostic and prognostic tool.

BACKGROUND: Telomerase reverse transcriptase (TERT) activation has been shown to be an important cancer hallmark; the activation and expression of TERT has been documented in >90% of tumors and TERT activation has been touted as a prognostic marker in many cancers. However, there is currently no simple testing modality to detect TERT mRNA expression in surgical pathology specimens. In this study we aim to evaluate and validate the utility and reliability of the TERT RNAscope® in-situ hybridization (ISH) assay for the detection of TERT mRNA expression in formalin-fixed, paraffin embedded tissue. METHODS AND MATERIALS: RNAscope® detection for TERT was performed on a Leica Biosystems BOND III research staining robot using the Hs-TERT-O1 (ACD, 481968) probe. Twenty three samples containing 48 tissue types were assessed. TERT genomic alterations were determined by targeted next generation sequencing (NGS), while TERT mRNA expression was determined by both targeted RNA-sequencing and TERT RNAscope® and the results compared. Manual vs automated TERT expression quantification methodologies were evaluated for the ISH assay. The expression levels in normal vs. neoplastic tissues were also compared. RESULTS: The RNAscope® assay showed high TERT expression in neoplastic tissues, while most normal tissues have no or very low expression levels (p-value= 0.0001, AUC: 0.99). In addition, there was good correlation of TERT expression between the RNAscope® assay and RNA-sequencing. For RNAscope® quantification, manual calculation of TERT signal/cell ratio based on a count of 100 cells was superior compared to automated signal detection. CONCLUSION: TERT RNAscope® assay is a simple and reliable tool for the evaluation of TERT mRNA expression. TERT signal/cell ratio based on a count of 100 cells is a reproducible and accurate interpretation approach for evaluation of TERT expression.

Physician Global Assessment as a Disease Activity Measure for Relapsing Polychondritis.

OBJECTIVE: Relapsing polychondritis (RP) is a systemic inflammatory disorder of cartilage that lacks validated disease activity measures. Our objective was to test physician global assessment (PhGA), a measure of disease activity commonly used in rheumatic diseases, in a cohort of patients with RP, which has not been done before. METHODS: Adult patients in an observational cohort of RP underwent standardized, comprehensive evaluation at approximately 6-month intervals. PhGA was scored by 3 physicians from the evaluating institution on a scale of 0-10 for each visit. A random subset of 20 visits was scored by 3 independent physicians not affiliated with the evaluating institution. Treatment change between consecutive visits was categorized as increased, decreased, or unchanged. RESULTS: In total, 78 patients were evaluated over 164 visits. The intraclass correlation coefficient (ICC2,1 ) for the 3 raters from the evaluating institution was excellent (0.79 [95% confidence interval (95% CI) 0.73, 0.84]) but was poor in the subset of cases scored by the additional raters (ICC2,1 0.27 [95% CI -0.01, 0.53]). Median PhGA was 3 (range 0-7). PhGA weakly correlated with C-reactive protein level (rs = 0.30, P < 0.01). In response to increased treatment, median PhGA decreased from 3 (interquartile range [IQR] 2, 4) to 2 (IQR 2, 3) (P < 0.01) but rarely went to 0. CONCLUSION: Within a single center, PhGA can be used to quantify disease activity and monitor disease response in RP. Persistent disease activity despite treatment, rather than a relapsing-remitting pattern, is observed for most patients with RP. Reliability of PhGA may not generalize across different institutions. A validated disease-specific activity index is needed in RP.

Discordance in patient and physician global assessment in relapsing polychondritis.

OBJECTIVES: Relapsing polychondritis (RP) is a rare, heterogeneous, systemic inflammatory disease that targets cartilage. Patient-reported outcome measures may differ from physician assessment. This study compared patient global assessment (PtGA) and physician global assessment (PhGA) scores in a prospective cohort of patients with RP. METHODS: Adult patients with RP underwent a standardized comprehensive evaluation at ∼6 month intervals. At each visit, three physicians scored PhGA by consensus. The patient independently completed four patient-reported outcomes: PtGA, 36-item Short Form Health Survey (SF-36), Brief Illness Perception Questionnaire (BIPQ) and Multidimensional Fatigue Inventory (MFI). Patient-physician discordance was defined as a difference between PtGA and PhGA of ≥3 on a 0-10 scale. RESULTS: A total of 76 patients were evaluated over 154 visits. The median PhGA was 3 [interquartile range (IQR) 2-3] and the median PtGA was 5 (IQR 4-7). PtGA and PhGA were concordant in 66 visits (42.9%) and patients scored disease severity ≥3 points higher than physicians scored disease activity (positive discordance) in 84 visits (54.5%). Compared with visits with concordance, visits with positive discordance were associated with significantly worse scores on the MFI, BIPQ, SF-36 physical component score and SF-36 mental component score. CONCLUSION: Patients with RP typically self-report high PtGA that does not align with PhGA. Discordance is likely driven by the high physical and psychological burden of illness experienced by patients. Multifaceted treatment approaches that address the burden of disease in RP from the patient perspective are needed.

Somatic Mutations in UBA1 Define a Distinct Subset of Relapsing Polychondritis Patients With VEXAS.

OBJECTIVE: Somatic mutations in UBA1 cause a newly defined syndrome known as VEXAS (vacuoles, E1 enzyme, X-linked, autoinflammatory, somatic syndrome). More than 50% of patients currently identified as having VEXAS met diagnostic criteria for relapsing polychondritis (RP), but clinical features that characterize VEXAS within a cohort of patients with RP have not been defined. We undertook this study to define the prevalence of somatic mutations in UBA1 in patients with RP and to create an algorithm to identify patients with genetically confirmed VEXAS among those with RP. METHODS: Exome and targeted sequencing of UBA1 was performed in a prospective observational cohort of patients with RP. Clinical and immunologic characteristics of patients with RP were compared based on the presence or absence of UBA1 mutations. The random forest method was used to derive a clinical algorithm to identify patients with UBA1 mutations. RESULTS: Seven of 92 patients with RP (7.6%) had UBA1 mutations (referred to here as VEXAS-RP). Patients with VEXAS-RP were all male, were on average ≥45 years of age at disease onset, and commonly had fever, ear chondritis, skin involvement, deep vein thrombosis, and pulmonary infiltrates. No patient with VEXAS-RP had chondritis of the airways or costochondritis. Mortality was greater in VEXAS-RP than in RP (23% versus 4%; P = 0.029). Elevated acute-phase reactants and hematologic abnormalities (e.g., macrocytic anemia, thrombocytopenia, lymphopenia, multiple myeloma, myelodysplastic syndrome) were prevalent in VEXAS-RP. A decision tree algorithm based on male sex, a mean corpuscular volume >100 fl, and a platelet count <200 ×103 /µl differentiated VEXAS-RP from RP with 100% sensitivity and 96% specificity. CONCLUSION: Mutations in UBA1 were causal for disease in a subset of patients with RP. This subset of patients was defined by disease onset in the fifth decade of life or later, male sex, ear/nose chondritis, and hematologic abnormalities. Early identification is important in VEXAS given the associated high mortality rate.

Patient Sleep Quality in Acute Inpatient Rehabilitation.

BACKGROUND: Sleep is an important component of neurorehabilitation. This study evaluates sleep quality in the acute inpatient rehabilitation setting and is the first to compare sleep quality in acute rehabilitation versus the acute care hospital and home settings. OBJECTIVE: To assess patient sleep quality in the acute inpatient rehabilitation setting. DESIGN: Cross-sectional survey study. SETTING: Acute inpatient rehabilitation unit. PATIENTS: Seventy-three patients admitted to the acute rehabilitation unit participated in the study. INTERVENTIONS: A validated sleep questionnaire was provided on admission regarding sleep at home and in the acute care hospital. The questionnaire was repeated on discharge from the acute rehabilitation unit regarding sleep during their rehabilitation admission. MAIN OUTCOME MEASURES: Visual analog scale of sleep depth, falling asleep, number of awakenings, percentage of time awake, and quality of sleep were obtained through use of the Richards-Campbell Sleep Questionnaire. These values were averaged to obtain "overall sleep perception." An additional question on environmental noise was added. Scores ranged from 0 for "worst sleep possible" to 100 for "best sleep possible." RESULTS: Patients reported significantly better sleep in all domains and overall in the acute rehabilitation unit compared to the acute care hospital, with the exception of percentage of time awake. Patients also reported significantly better sleep depth but worse noise in the acute rehabilitation unit when compared to home. Similarly, patients reported significantly better sleep in all domains and overall at home in comparison to the acute care hospital with the exception of percentage of time awake. CONCLUSIONS: Patient in the acute rehabilitation unit experience sleep quality that matches their experience at home and exceeds that in the hospital.

Defining Clinical Subgroups in Relapsing Polychondritis: A Prospective Observational Cohort Study.

OBJECTIVE: Relapsing polychondritis (RP) is a systemic disease. Failure to recognize RP can lead to diagnostic delay and further complications, including death. This study was undertaken to identify clinical patterns in a prospective cohort of patients with RP. METHODS: Patient subgroups were identified using latent class analysis based on 8 clinical variables: saddle-nose deformity, subglottic stenosis, tracheomalacia, bronchomalacia, ear chondritis, tenosynovitis/synovitis, inflammatory eye disease, and audiovestibular disease. Model selection was based on Akaike's information criterion. RESULTS: Seventy-three patients were included in this study. Patients were classified into 1 of 3 subgroups: type 1 RP (14%), type 2 RP (29%), and type 3 RP (58%). Type 1 RP was characterized by ear chondritis (100%), tracheomalacia (100%), saddle-nose deformity (90%), and subglottic stenosis (80%). These patients had the shortest median time to diagnosis (1 year), highest disease activity, and greatest frequency of admission to the intensive care unit and tracheostomy. Type 2 RP was characterized by tracheomalacia (100%) and bronchomalacia (52%), but no saddle-nose deformity or subglottic stenosis. These patients had the longest median time to diagnosis (10 years) and highest percentage of work disability. Type 3 RP was characterized by tenosynovitis/synovitis (60%) and ear chondritis (55%). There were no significant differences in sex, race, or treatment strategies between the 3 subgroups. CONCLUSION: Our findings indicate that there are 3 subgroups of patients with RP, with differences in time to diagnosis, clinical and radiologic characteristics, and disease-related complications. Recognizing a broader spectrum of clinical patterns in RP, beyond cartilaginous involvement of the ear and upper airway, may facilitate more timely diagnosis.

The Effect of a Screen Protector on Blue Light Intensity Emitted from Different Hand-held Devices.

PURPOSE: In response to growing concern about the effect of blue light on ocular tissue, companies have created mobile device screen protectors to block blue light. This project evaluates one of these screen protectors' ability to reduce blue light intensity. METHODS: The intensity of light at 450 nm from an iPhone 8, iPhone X, and iPad was measured in a dark room. The averages of three measurements were taken with and without the screen protector at different distances, settings of brightness, and Apple's night shift (NS) mode. Results were analyzed using paired t-tests. RESULTS: At 33 cm, 100% brightness, and 0% NS, the screen protector decreased intensity by 43.9%, 32.3%, and 34.9% for the iPhone 8, iPhone X, and iPad, respectively. At 33 cm and 100% brightness, increasing NS mode from 0% to 100% decreased intensity by 81.2%, 84.2%, and 86.5%. At 33 cm without NS, decreasing the brightness from 100% to 0% decreased intensity by 99.5%, 99.8%, and 97.8%. CONCLUSIONS: The screen protector decreased the intensity at 450 nm for every setting other than those at 0% brightness. Decreasing brightness and applying NS mode were more effective in reducing blue light. More research is needed to determine the benefits of decreasing blue light exposure from electronic devices.

Cost-effective Alternative for Negative-pressure Wound Therapy.

BACKGROUND: Current predominantly used equipments for negative-pressure wound therapy (NPWT) are expensive. In current healthcare climate continually emphasizing cost containment, importance in developing more cost-effective alternatives cannot be understated. Previously, therapeutically equivalent methods of providing NPWT was demonstrated using just low-cost, universally available supplies, coined Gauze-SUCtion (GSUC). Here, we examine long-term potential financial savings of utilizing GSUC over commercialized products. METHODS: A retrospective cost analysis was performed at the University of Chicago Medical Center between 1999 and 2014. All NPWT was provided via either GSUC or commercialized vacuum-assisted closure (VAC, KCI) device. Sum of all material component costs were reviewed to determine theoretical average daily cost. For the VAC group, recorded institutional spend to KCI was also reviewed to determine actual daily cost. In the GSUC group, this figure was extrapolated using similar ratios. Labor costs for each method were determined using analysis from prior study. Patient demographics, etiology, wound location, and treatment length were also reviewed. RESULTS: Total of 35,871 days of NPWT was provided during the 15-year span. Theoretical average cost of VAC was $94.01/d versus $3.61/d for GSUC, whereas actual average was $111.18/d versus $4.26/d. Average labor cost was $20.11/dressing change versus $12.32. Combined, total cost of VAC therapy was estimated at $119,224 per every 1,000 days of therapy versus $9,188 for the GSUC. CONCLUSIONS: There is clear and significant cost savings from utilization of GSUC method of NPWT. Furthermore, the added advantage of being able to provide NPWT from universally accessible materials cannot be overstated.

CdiA Effectors from Uropathogenic Escherichia coli Use Heterotrimeric Osmoporins as Receptors to Recognize Target Bacteria.

Many Gram-negative bacterial pathogens express contact-dependent growth inhibition (CDI) systems that promote cell-cell interaction. CDI+ bacteria express surface CdiA effector proteins, which transfer their C-terminal toxin domains into susceptible target cells upon binding to specific receptors. CDI+ cells also produce immunity proteins that neutralize the toxin domains delivered from neighboring siblings. Here, we show that CdiAEC536 from uropathogenic Escherichia coli 536 (EC536) uses OmpC and OmpF as receptors to recognize target bacteria. E. coli mutants lacking either ompF or ompC are resistant to CDIEC536-mediated growth inhibition, and both porins are required for target-cell adhesion to inhibitors that express CdiAEC536. Experiments with single-chain OmpF fusions indicate that the CdiAEC536 receptor is heterotrimeric OmpC-OmpF. Because the OmpC and OmpF porins are under selective pressure from bacteriophages and host immune systems, their surface-exposed loops vary between E. coli isolates. OmpC polymorphism has a significant impact on CDIEC536 mediated competition, with many E. coli isolates expressing alleles that are not recognized by CdiAEC536. Analyses of recombinant OmpC chimeras suggest that extracellular loops L4 and L5 are important recognition epitopes for CdiAEC536. Loops L4 and L5 also account for much of the sequence variability between E. coli OmpC proteins, raising the possibility that CDI contributes to the selective pressure driving OmpC diversification. We find that the most efficient CdiAEC536 receptors are encoded by isolates that carry the same cdi gene cluster as E. coli 536. Thus, it appears that CdiA effectors often bind preferentially to "self" receptors, thereby promoting interactions between sibling cells. As a consequence, these effector proteins cannot recognize nor suppress the growth of many potential competitors. These findings suggest that self-recognition and kin selection are important functions of CDI.

The F pilus mediates a novel pathway of CDI toxin import.

Contact-dependent growth inhibition (CDI) is a widespread form of inter-bacterial competition that requires direct cell-to-cell contact. CDI(+) inhibitor cells express CdiA effector proteins on their surface. CdiA binds to specific receptors on susceptible target bacteria and delivers a toxin derived from its C-terminal region (CdiA-CT). Here, we show that purified CdiA-CT(536) toxin from uropathogenic Escherichia coli 536 translocates into bacteria, thereby by-passing the requirement for cell-to-cell contact during toxin delivery. Genetic analyses demonstrate that the N-terminal domain of CdiA-CT(536) is necessary and sufficient for toxin import. The CdiA receptor plays no role in this import pathway; nor do the Tol and Ton systems, which are exploited to internalize colicin toxins. Instead, CdiA-CT(536) import requires conjugative F pili. We provide evidence that the N-terminal domain of CdiA-CT(536) interacts with F pilin, and that pilus retraction is critical for toxin import. This pathway is reminiscent of the strategy used by small RNA leviviruses to infect F(+) cells. We propose that CdiA-CT(536) mimics the pilin-binding maturation proteins of leviviruses, allowing the toxin to bind F pili and become internalized during pilus retraction.

Pyoderma gangrenosum: A case report of bilateral dorsal hand lesions and literature review of management.

Pyoderma gangrenosum is a great masquerader in wound diagnosis and management. Frequently misdiagnosed as a necrotizing infection, the elusive nature of its etiology and pathogenesis has thwarted the establishment of a standardized management algorithm, leaving immunosuppressant therapies as the mainstay of treatment. The present report describes a 61-year-old woman presenting with temporally discrete bilateral dorsal hand lesions successfully managed with distinctive multimodality therapies. The initial lesion was managed under the auspices of a necrotizing process using a combination of hyperbaric oxygen therapy and skin grafting with a negative-pressure dressing, both individually demonstrated to be effective for prompt wound stabilization and coverage. A subsequent contralateral hand lesion was similarly managed as a necrotizing infection before a diagnosis of pyoderma gangrenosum was considered. Stabilization and eventual resolution was achieved using intravenous and topical steroids followed by hyperbaric oxygen therapy, again highlighting the benefits of multimodality therapy in the setting of pyoderma gangrenosum.

La pyodermite gangréneuse provoque souvent de faux diagnostics et de mauvaises prises en charge des plaies. Elle est souvent diagnostiquée à tort comme une infection nécrosante, et la nature insaisissable de son étiologie et de sa pathogenèse contrecarre la création d'un algorithme de prise en charge standardisé, laissant les immunosuppresseurs comme pivots du traitement. Le présent rapport décrit le cas d'une femme de 61 ans qui a consulté en raison de lésions bilatérales du dos des mains discrètes temporelles, prises en charge avec succès par des thérapies multimodales distinctives. La lésion initiale a été traitée sous les auspices d'un processus nécrosant faisant appel à un mélange de thérapie par oxygène hyperbare et de greffe de la peau accompagnée d'un pansement en pression négative, car il est démontré que chacun de ces traitements stabilise et couvre rapidement la plaie avec efficacité. Une lésion controlatérale subséquente a été également prise en charge comme s'il s'agissait d'une lésion nécrosante avant qu'on envisage un diagnostic de pyodermite gangréneuse. Les médecins ont réussi à stabiliser, puis à résoudre le problème à l'aide de stéroïdes intraveineux et topiques suivis d'une thérapie par oxygène hyperbare, faisant de nouveau ressortir les avantages de la thérapie multimodale en présence d'une pyodermite gangréneuse.

Applications of biomaterials in plastic surgery.

The expansion of the application of biomaterials in plastic surgery has led to the increased availability of commercial products in recent years. This overview discusses soft tissue fillers, bioengineered skins, acellular dermal matrices, biomaterials for craniofacial surgery, and peripheral nerve repair. We summarize indications, properties, uses, types, advantages and disadvantages of some of the currently available products from each category. Finally, the current state of development in drug delivery system is also briefly summarized.

Single-fraction stereotactic body radiation therapy and sequential gemcitabine for the treatment of locally advanced pancreatic cancer.

PURPOSE: This Phase II trial evaluated the toxicity, local control, and overall survival in patients treated with sequential gemcitabine and linear accelerator-based single-fraction stereotactic body radiotherapy (SBRT). METHODS AND MATERIALS: Twenty patients with locally advanced, nonmetastatic pancreatic adenocarcinoma were enrolled on this prospective single-institution, institutional review board-approved study. Gemcitabine was administered on Days 1, 8, and 15, and SBRT on Day 29. Gemcitabine was restarted on Day 43 and continued for 3-5 cycles. SBRT of 25 Gy in a single fraction was delivered to the internal target volume with a 2- 3-mm margin using a nine-field intensity-modulated radiotherapy technique. Respiratory gating was used to account for breathing motion. Follow-up evaluations occurred at 4-6 weeks, 10-12 weeks, and every 3 months after SBRT. RESULTS: All patients completed SBRT and a median of five cycles of chemotherapy. Follow-up for the 2 remaining alive patients was 25.1 and 36.4 months. No acute Grade 3 or greater nonhematologic toxicity was observed. Late Grade 3 or greater toxicities occurred in 1 patient (5%) and consisted of a duodenal perforation (G4). Three patients (15%) developed ulcers (G2) that were medically managed. Overall, median survival was 11.8 months, with 1-year survival of 50% and 2-year survival of 20%. Using serial computed tomography, the freedom from local progression was 94% at 1 year. CONCLUSION: Linear accelerator-delivered SBRT with sequential gemcitabine resulted in excellent local control of locally advanced pancreatic cancer. Future studies will address strategies for reducing long-term duodenal toxicity associated with SBRT.

Fluostatins produced by the heterologous expression of a TAR reassembled environmental DNA derived type II PKS gene cluster.

Culture independent approaches for accessing small molecules produced by uncultured bacteria are often hampered by the inability to easily clone environmental DNA (eDNA) fragments large enough to capture intact biosynthetic gene clusters that can be used in heterologous expression studies. Here we show that homology screening of eDNA megalibraries for clones containing natural product biosynthetic genes, coupled with transformation-assisted recombination (TAR) in yeast, can be used to access large, functionally intact, natural product gene clusters from the environment. The eDNA derived gene cluster reported here was functionally reconstructed from two overlapping cosmid clones using TAR. The isolation and structure elucidation of three new fluostatins (F, G, and H) produced by this TAR reconstructed gene cluster is described.

A dosimetric model of duodenal toxicity after stereotactic body radiotherapy for pancreatic cancer.

INTRODUCTION: Dose escalation for pancreas cancer is limited by the tolerance of adjacent normal tissues, especially with stereotactic body radiotherapy (SBRT). The duodenum is generally considered to be the organ at greatest risk. This study reports on the dosimetric determinants of duodenal toxicity with single-fraction SBRT. METHODS AND MATERIALS: Seventy-three patients with locally advanced unresectable pancreatic adenocarcinoma received 25 Gy in a single fraction. Dose-volume histogram (DVH) endpoints evaluated include V(5) (volume of duodenum that received 5 Gy), V(10), V(15), V(20), V(25), and D(max) (maximum dose to 1 cm(3)). Normal tissue complication probability (NTCP) was evaluated with a Lyman model. Univariate and multivariate analyses were conducted with Kaplan-Meier and Cox regression models. RESULTS: The median time to Grade 2-4 duodenal toxicity was 6.3 months (range, 1.6-11.8 months). The 6- and 12-month actuarial rates of toxicity were 11% and 29%, respectively. V(10)-V(25) and D(max) all correlated significantly with duodenal toxicity (p<0.05). In particular, V(15)≥9.1 cm(3) and V(15)<9.1 cm(3) yielded duodenal toxicity rates of 52% and 11%, respectively (p=0.002); V(20)≥3.3 cm(3) and V(20)<3.3 cm(3) gave toxicity rates of 52% and 11%, respectively (p=0.002); and D(max)≥23 Gy and D(max)<23 Gy gave toxicity rates of 49% and 12%, respectively (p=0.004). Lyman NTCP model optimization generated the coefficients m=0.23, n=0.12, and TD(50)=24.6 Gy. Only the Lyman NTCP model remained significant in multivariate analysis (p=0.001). CONCLUSIONS: Multiple DVH endpoints and a Lyman NTCP model are strongly predictive of duodenal toxicity after SBRT for pancreatic cancer. These dose constraints will be valuable in future abdominal SBRT studies.