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The continuing evolution of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants with decreased susceptibility to neutralizing antibodies is of clinical importance. Several spike mutations associated with immune escape have evolved independently in association with different variants of concern (VOCs). How and when these mutations arise is still unclear. We hypothesized that such mutations might arise in the context of persistent viral replication in immunosuppressed hosts.Nasopharyngeal specimens were collected longitudinally from two immunosuppressed patients with persistent SARS-CoV-2 infection. Plasma was collected from these same patients late in disease course. SARS-CoV-2 whole genome sequencing was performed to assess the emergence and frequency of mutations over time. Select Spike mutations were assessed for their impact on viral entry and antibody neutralization in vitro.Our sequencing results revealed the intrahost emergence of spike mutations that are associated with circulating VOCs in both immunosuppressed patients (del241-243 and E484Q in one patient, and E484K in the other). These mutations decreased antibody-mediated neutralization of pseudotyped virus particles in cell culture, but also decreased efficiency of spike-mediated cell entry.These observations demonstrate the de novo emergence of SARS-CoV-2 spike mutations with enhanced immune evasion in immunosuppressed patients with persistent infection. These data suggest one potential mechanism for the evolution of VOCs and emphasize the importance of continued efforts to develop antiviral drugs for suppression of viral replication in hospitalized settings.

Ibrutinib, a known Burton's tyrosine kinase (BTK) and interleukin‐2 inducible T‐cell kinase (ITK) inhibitor, is used for the treatment of B‐cell disorders (chronic lymphocytic leukemia [CLL] and various other lymphomas) and chronic graft versus host disease following allogeneic hematopoietic cell transplantation. Because it is considered an immunosuppressant, continuation of ibrutinib is often debated when patients have an active infection, and this becomes an especially difficult decision in the setting of coronavirus disease 2019 (COVID‐19). Here, we describe a patient with CLL who was on ibrutinib then developed severe COVID‐19 infection requiring mechanical ventilation. We elected to continue ibrutinib the same day he was intubated, reasoning that BTK inhibition in myeloid immune cells has been shown to reduce or even reverse influenza‐mediated acute lung injury and that ITK inhibition in T cells has correlated with reduction in viral replication, and therefore may have an advantage in this setting. Ibrutinib also has been shown to block Src family kinases, which potentially could result in reduction of viral entry and the inflammatory cytokine response in the lungs. The patient was extubated after 9 days with a complex hospital course and eventually discharged on room air. The only way to rationally inform these decisions and explore similar potentially promising leads in this pandemic is to conduct carefully done clinical trials.

BACKGROUND There is no clear consensus between pediatric and adult providers about the treatment of adolescents and young adults (AYAs) with Hodgkin lymphoma (HL). METHODS Failure-free survival (FFS) and overall survival (OS) were compared between 114 patients ages 17 to 21 years with HL who were treated on the Eastern Cooperative Oncology Group-American College of Radiology Imaging Network Intergroup adult E2496 study and 391 similarly patients ages 17 to 21 years with HL who were treated on the pediatric Children's Oncology Group (COG) AHOD0031 study. RESULTS Comparing AYAs from the COG and E2496 studies, there were no significant differences in extralymphatic disease, anemia, or hypoalbuminemia. More AYAs in the E2496 trial had stage III and IV disease (63% vs 29%; P < .001) and B symptoms (63% vs 27%; P < .001), and fewer had bulk disease (33% vs 77%; P < .001). More AYAs on the COG trial received radiotherapy (76% vs 66%; P = .03), although in smaller doses. E2496 AYA The 5-year FFS and OS rates were 68% and 89%, respectively in the E2496 AYAs and 81% and 97%, respectively, in the COG AYAs, indicating a statistically superior compared in the COG AYAs (P = .001). In stratified multivariable analyses, E2496 AYAs had worse FFS than COG AYAs in all strata except patients who had stage I and II HL without anemia. Propensity score analysis (based on stage, anemia, and bulk disease) confirmed inferior FFS for E2496 AYAs compared with COG AYAs (P = .004). On the E2496 study, FFS was significantly divergent across age groups (P = .005), with inferior outcomes for those ages 17 to 21 years versus 22-44 years. There was no difference across age on the COG study. CONCLUSIONS Younger AYA patients with HL appear to have better outcomes when treated on a pediatric trial than patients of similar age on an adult trial. Prospective studies examining these differences are warranted. Cancer 2017. © 2017 American Cancer Society.

A general mathematical model that describes the temporal behavior of a real‐time isothermal process used for nucleic acid amplification is derived. A monotonically‐increasing fluorescence signal s(t) generated and measured during the amplification reaction can be modeled in the form of a logistic function of time that is completely described by three parameters (k, t50, and Smax), which may be readily estimated from experimentally acquired s(t) data. Experimental data obtained from a real‐time loop‐mediated isothermal amplification (LAMP) assay for the infectious pathogen Erwinia amylovora (E. amylovora) are used to illustrate and validate the mathematical model. Implementation of such a modeling approach can allow for the extraction of quantitative information from real‐time LAMP data through parameter estimation techniques; this is demonstrated experimentally using real‐time amplification data acquired using the real‐time E. amylovora assay.

BACKGROUND In an ECOG-ACRIN Cancer Research Group study (E1496), maintenance rituximab (MR) was reported to prolong progression-free survival (PFS) in comparison with observation (OBS) alone in patients with indolent lymphoma after induction chemotherapy. Here the long-term follow-up of the same patient cohort is presented. METHODS Patients with indolent lymphoma received induction chemotherapy with cyclophosphamide, vincristine, and prednisone (CVP). Patients with stable disease or a better response were then randomized to weekly rituximab (375 mg/m2 × 4 doses) every 6 months for 2 years (MR) or to OBS. The primary endpoint was PFS; the secondary endpoints were overall survival (OS), response rate, and toxicities. RESULTS Of the 387 patients who initially received CVP induction, 158 were randomized to MR, and 153 were randomized to OBS. After a median follow-up of 11.5 years, patients on MR had longer median PFS (4.8 years) than patients on OBS (1.3 years; hazard ratio [HR], 0.49; P < .0001). However, there was no difference in OS between MR and OBS (10-year OS, 67% vs 59%; median OS, 13.5 years vs not reached; HR, 0.91; P = .69). Other than MR, only minimal residual disease after induction therapy was significantly associated with PFS on multivariate analysis (HR, 0.71; P = .02). A low initial tumor burden, minimal residual disease, follicular histology, a low Follicular Lymphoma International Prognostic Index score, and female sex were associated with longer OS. There was no increase in the rate of second primary malignancies with MR vs OBS. CONCLUSIONS With long-term follow-up, MR did not influence OS. The PFS benefit was maintained. MR should be considered optional for patients with indolent B-cell lymphoma. Cancer 2016;122:2996-3004. © 2016 American Cancer Society.

BACKGROUND The role of consolidation radiotherapy was examined for patients with diffuse large B-cell lymphoma who were treated at institutions of the National Comprehensive Cancer Network during the rituximab era. METHODS Failure-free survival (FFS) and overall survival (OS) were analyzed in terms of patient and treatment characteristics. Potential associations were investigated with univariate and multivariate survival analysis and matched pair analysis. RESULTS There were 841 patients, and most (710 or 84%) received 6 to 8 cycles of rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP); 293 (35%) received consolidation radiation therapy (RT). Failure occurred for 181 patients: 126 patients (70%) who did not receive RT and 55 patients (30%) who did. At 5 years, both OS and FFS rates were better for patients who had received RT versus those who did not (OS, 91% vs 83% [P = .01]; FFS, 83% vs 76% [P = .05]). A matched pair analysis (217 pairs matched by age, stage, International Prognostic Index [IPI] score, B symptoms, disease bulk, and response to chemotherapy) showed that the receipt of RT improved OS (hazard ratio [HR], 0.53 [P = .07]) and FFS (HR, 0.77 [P = .34]) for patients with stage III/IV disease, but too few events took place among those with stage I/II disease for meaningful comparisons (HR for OS, 0.94 [P = .89]; HR for FFS, 1.81 [P = .15]). A multivariate analysis suggested that the IPI score and the response to chemotherapy had the greatest influence on outcomes. CONCLUSIONS There was a trend of higher OS and FFS rates for patients who had received consolidation RT after R-CHOP (especially for patients with stage III/IV disease), but the difference did not reach statistical significance. Cancer 2014. © 2014 American Cancer Society. Cancer 2015;121:1032–1039. © 2014 American Cancer Society.

Summary There is a lack of published data examining non-cytotoxic options for the frontline treatment of patients with high-tumour burden (HTB) indolent non-Hodgkin lymphoma (iNHL). We completed a multicentre phase II study for patients with untreated HTB iNHL (NCT00369707) consisting of three induction cycles of weekly bortezomib and rituximab followed by an abbreviated consolidation. Forty-two patients were treated and all were evaluable; the most common histology was follicular lymphoma (FL) (n = 33, 79%). Patient characteristics included median age 62 years (40–86); 38% bulky disease; 19% malignant effusions; 91% advanced-stage disease; and median FL International Prognostic Index (FLIPI) score was 3. Therapy was well tolerated with few grade 3/4 toxicities including minimal neurotoxicity. On intent-to-treat, the overall response rate (ORR) at end of therapy was 70% with a complete remission (CR) rate of 40% (FL: ORR 76%, CR 44%). With 50-month median follow-up, 4-year progression-free survival (PFS) was 44% with 4-year overall survival (OS) of 87% (FL: 44% and 97%, respectively). Four-year PFS for FLIPI 0–2 vs. 3–5 was 60% vs. 26% respectively (P = 0·02), with corresponding OS rates of 92% and 81% respectively (P = 0·16). Collectively, bortezomib/rituximab is a non-cytotoxic therapeutic regimen that was well tolerated and resulted in long-term survival rates approximating prior rituximab/cytotoxic chemotherapy series for untreated HTB FL.

BACKGROUND T-cell lymphomas (TCLs) are uncommon in the United States. The accurate diagnosis of TCL is challenging and requires morphologic interpretation, immunophenotyping, and molecular techniques. The authors compared pathologic diagnoses at referring centers with diagnoses from expert hematopathology review to determine concordance rates and to characterize the usefulness of second-opinion pathology review for TCL. METHODS Patients in the National Comprehensive Cancer Network non-Hodgkin lymphoma database with peripheral TCL, not otherwise specified (PTCL-NOS), angioimmunoblastic TCL (AITL), and anaplastic lymphoma kinase (ALK)-positive and ALK-negative anaplastic large cell lymphoma (ALCL) were eligible if they had prior tissue specimens examined at a referring institution. Pathologic concordance was evaluated using available pathology and diagnostic testing reports and provider progress notes. The etiology of discordance and the potential impact on treatment were examined. RESULTS Among 131 eligible patients, 57 (44%) had concordant results, totaling 64% of the 89 patients who were referred with a final diagnosis. Thirty-two patients (24%) had discordant results, representing 36% of those who were referred with a final diagnosis. The rates of discordance among patients with of PTCL-NOS, AITL, ALK-negative ALCL, and ALK-positive ALCL were 19%, 33%, 34%, and 6%, respectively. In 14 patients (44% of discordant results), pathologic reclassification could have resulted in a different therapeutic strategy. Forty-two patients (32%) were referred for classification with a provisional diagnosis. CONCLUSIONS In a large cohort of patients with TCL who were referred to National Comprehensive Cancer Network centers, the likelihood of a concordant final diagnosis at a referring institution was low. As current and future therapies target TCL subsets, these data suggest that patients with suspected TCLs would benefit from evaluation by an expert hematopathologist. Cancer 2014;120:1993–1999. © 2014 American Cancer Society.

Histological transformation (HT) is a major cause of morbidity and mortality in patients with indolent non-Hodgkin lymphoma (NHL). The multicentre National Cancer Comprehensive Network database for NHL provides a unique opportunity to investigate the natural history of HT in the rituximab era. 118 patients with biopsy-confirmed indolent lymphoma and subsequent biopsy-confirmed HT were identified. Treatments for HT included autologous stem-cell transplant (auto-SCT) (n = 50), allogeneic SCT (allo-SCT) (n = 18), and treatment without transplant (n = 50). The 2-year overall survival (OS) for the entire cohort was 68%. For auto-SCT patients aged ≤ 60 years (n = 24), the 2-year OS was 74%. For non-transplanted patients aged ≤ 60 years (n = 19), the 2-year OS was 59%. The 2-year OS of patients naïve to chemotherapy prior to HT was superior to patients who were exposed to chemotherapy prior to HT (100% vs. 35%, P = 0.03). In this largest prospective cohort of patients of strictly defined HT in the rituximab era, the natural history of HT appears more favourable than historical studies. Younger patients who were not exposed to chemotherapy prior to HT experienced a prolonged survival even without transplantation. This study serves as a benchmark for future trials of novel approaches for HT in the Rituximab era.

There remains an unmet therapeutic need for patients with relapsed/refractory diffuse large B-cell lymphoma (DLBCL) and peripheral T-cell lymphoma (PTCL). We conducted a phase I/II trial with bortezomib (dose-escalated to 1·6 mg/m(2) ) given concurrently with gemcitabine (800 mg/m(2) ) days 1 + 8 q21 d. Of 32 patients, 16 each had relapsed/refractory PTCL and DLBCL. Median prior therapies were 3 and 35% had failed transplant. Among the first 18 patients, 67% experienced grade 3/4 neutropenia and/or grade 3/4 thrombocytopenia resulting in repeated treatment delays (relative dose intensity: 46%). Thus, the study was amended to give bortezomib and gemcitabine days 1 + 15 q28 d, which resulted in markedly improved tolerability. Among all patients, the overall response rate (ORR) was 24% with 19% complete remission (CR; intent-to-treat (ITT) ORR 16%, CR 13%), which met criteria for futility. The ORR for DLBCL was 10% (CR 10%) vs. 36% for PTCL (CR 27%). Among 6 PTCL patients treated on the modified schedule, ORR by ITT was 50% (CR 30%). Altogether, concurrent bortezomib/gemcitabine given days 1 + 8 q21 d was not tolerable, while modification to a bi-monthly schedule allowed consistent treatment delivery. Whereas efficacy of this combination was low in heavily pre-treated DLBCL, there was a signal of activity in relapsed/refractory PTCL utilizing the modified schedule.

Bacteroides thetaiotaomicron is a prominent member of the human distal gut microbiota that specializes in breaking down diet and host-derived polysaccharides. While polysaccharide utilization has been well studied in B. thetaiotaomicron, other aspects of its behavior are less well characterized, including the factors that allow it to maintain itself in the gut. Biofilm formation may be a mechanism for bacterial retention in the gut. Therefore, we used custom GeneChips to compare the transcriptomes of biofilm and planktonic B. thetaiotaomicron during growth in mono-colonized chemostats. We identified 1,154 genes with a fold-change greater than 2, with confidence greater than or equal to 95%. Among the prominent changes observed in biofilm populations were: (i) greater expression of genes in polysaccharide utilization loci that are involved in foraging of O-glycans normally found in the gut mucosa; and (ii) regulated expression of capsular polysaccharide biosynthesis loci. Hierarchical clustering of the data with different datasets, which were obtained during growth under a range of conditions in minimal media and in intestinal tracts of gnotobiotic mice, revealed that within this group of differentially expressed genes, biofilm communities were more similar to the in vivo samples than to planktonic cells and exhibited features of substrate limitation. The current study also validates the use of chemostats as an in vitro "gnotobiotic" model to study gene expression of attached populations of this bacterium. This is important to gut microbiota research, because bacterial attachment and the consequences of disruptions in attachment are difficult to study in vivo.

Arsenic trioxide (ATO) is an effective therapeutic agent for acute promyelocytic leukemia (APL) (Evens et al, 2004). In APL, ATO induces differentiation at low concentrations, while inducing apoptosis at higher concentrations (Miller, et al 2002). In addition, ATO-induced apoptosis in APL is mediated through the mitochondrial apoptotic pathway, resulting in part from the production of reactive oxygen species (ROS) such as hydrogen peroxide (Dai, et al 1999, Yi, et al 2002). High intracellular levels of glutathione (GSH) confer resistance to ATO in part through the detoxification of ROS. Compounds that promote ROS and/or deplete protective metabolites such as GSH are able to sensitize tumor cells to oxidative cytolysis. Buthionine sulfoximine (BSO), a selective inhibitor of gamma glutamylcysteine synthetase, is known to effectively deplete cellular GSH (Davison, et al 2003, Gartenhaus, et al 2002). We evaluated herein the cytotoxic activity and cell death pathways induced by ATO alone and combined with BSO in non-Hodgkin’s lymphoma (NHL) cell lines and primary lymphoproliferative cells.

Metagenomics is an emerging field focused on characterizing the structures, functions and dynamic operations of microbial communities sampled in their native habitats without the need for culture. Here, we present findings from a 16S rRNA gene sequence- and whole community DNA shotgun sequencing-based analysis of the adult human gut microbiomes of lean and obese mono- and dizygotic twins. Our findings indicate that a core microbiome can be found at the gene level, despite large variation in community membership, and that variations from the core are associated with obesity. These findings have implications for ongoing Human Microbiome Project(s), and highlight important challenges to the field of metagenomics.

A novel biopolymer composed of porcine gelatin and dextran was used in a randomized controlled pilot clinical trial to treat diabetic foot ulcers to establish safety profile and evaluate effect on wound closure. Fifty-six patients were prospectively randomized at 10 centers (control = 25; E-Matrix = 31). Control patients received routine sharp debridement, off-loading, and hydrogel dressings applied daily. E-Matrix patients received identical wound care with the addition of monthly subcutaneous injections of E-Matrix under the wound surface. Patients were monitored for 12 weeks using wound planimetry and photography. Primary endpoint was safety as measured by adverse event reporting and clinical laboratory analysis. Secondary endpoint was wound closure based on intent to treat. There was no significant difference in the rate of adverse events between treated and control subjects. Overall closure rate for E-Matrix treated wounds was 42%(13 of 31 subjects) compared to 32%(8 of 25 subjects) for controls. Subgroup analysis suggested that E-Matrix may be more effective than control for treatment of larger (>2 cm2) and older (>17 weeks duration) wounds (see table). Parameter Treatment Group N Closed %Closed Size >2 cm E-Matrix 17 8 47% Control 14 4 29% Ulcer duration >17 weeks E-Matrix 15 6 40% Control 15 3 20% Although the study is insufficiently powered to evaluate statistical significance, E-Matrix demonstrated a similar safety profile to control treatment with trends toward improved healing in larger and older wounds. Further randomized trials are necessary to confirm these promising initial results.

Hypoxia-Inducible-Factors (HIFs) activate oncogenic pathways, while thioredoxins, including thioredoxin-1 (Trx1) and thioredoxin reductases-1 and -2 (TrxR1 and TrxR2), promote HIF-α stabilization. Elevated levels of thioredoxin or HIF have been associated with poor outcomes in solid tumors and each represent potential therapeutic targets. In lymphoma cell line immunoblotting studies, we found that Raji and SUDHL4 cells exhibited normoxic HIF-2α protein-stabilization. Furthermore, five lymphoma cell-lines showed increased TrxR1 expression, while only Namalwa, HF1, and SUDHL4 had Trx1 and TrxR2 activation. Utilizing tissue microarrays from diffuse large B-cell (DLBCL) and follicular lymphoma (FL) patient specimens (n=82), we found different frequency of HIF expression in FL versus DLBCL as well as differing HIF-1 versus HIF-2 expression within each histologic subgroup. Forty-four percent of DLBCL versus 11% of FL cases had moderate-to-high expression of both HIF-1α and HIF-2α (p=0.0017), while 56% of DLBCL and 32% of FL samples had at least low HIF-1α and HIF-2α expression (p=0.042). Survival analysis among newly-diagnosed DLBCL cases showed 44% 2-year event-free survival (EFS) and 67% overall survival (OS) with high HIF-1α and HIF-2α expression compared with 67% and 76%, respectively, (p=0.10 and p=0.64, respectively) without high expression. These data demonstrate that HIF and the thioredoxins are activated in lymphoma and that HIF expression may influence prognosis.

BACKGROUND. Radioimmunotherapy with radiolabeled monoclonal antibodies to CD20 produces a high response rate in patients with recurring non-Hodgkin lymphoma (NHL), but the durability of those remissions is not well defined. METHODS. Data on patients with recurring NHL treated with yttrium Y 90 ibritumomab tiuxetan in 4 clinical trials were reviewed to identify patients with a long-term response, defined as a time to progression of 12 months or longer. RESULTS. Long-term responses were seen in 37% (78/211) of patients. At a median follow-up of 53.5 months (range, 12.7–88.9) the median duration of response was 28.1 months and the median time to progression was 29.3 months. A third of these patients had been treated with at least 3 previous therapies, and 37% of them had not responded to their last therapy. The findings in patients with follicular lymphoma (n = 59) were similar to those in the overall population of long-term responders. The estimated overall survival at 5 years was 53% for all patients treated with 90Y ibritumomab tiuxetan and 81% for long-term responders. CONCLUSIONS. A single dose of 90Y ibritumomab tiuxetan can produce durable responses and prolonged overall survival in a substantial number of patients in whom previous therapies have failed. Cancer 2007. © 2007 American Cancer Society.

BACKGROUND. Low voriconazole levels have been associated with a higher failure rate in patients with confirmed fungal infections. METHODS. Steady-state plasma trough voriconazole levels were measured after at least 5 days of therapy in 87 patients with hematologic malignancies on 201 separate occasions (1–5 levels per patient; median, 2). Most patients (90%) had undergone allogeneic hematopoietic stem cell transplantation. The daily voriconazole dose, administered in 2 divided doses, was 200 mg (n = 4), 400 mg (n = 151), 500 mg (n = 20), 600 mg (n = 18), and 800 mg (n = 8); corresponding to 2.0–16.3 (median, 5.4) mg/kg. Plasma voriconazole levels were 0–12.5 μg/mL (median, 1.2). Voriconazole was undetectable (0.5 to 2.0, >2.0 to 5.0, and >5.0. Whereas the daily drug dose in mg/kg was significantly higher when the levels were >5.0 μg/mL, there was no consistent relation between dose and level below that threshold. In adult patients getting standard doses of voriconazole orally, the drug levels are highly variable. Based on limited available data, between a quarter and two-thirds of these levels could potentially be associated with a lower likelihood of response or a higher likelihood of failure. CONCLUSIONS. Future voriconazole studies should incorporate prospective therapeutic drug monitoring and consideration should be given to checking levels in patients receiving the drug for confirmed, life-threatening fungal infections. Cancer 2007. © 2007 American Cancer Society.

SPECT can be used to image regional cerebral blood flow (rCBF) and has been shown to help localize the seizure focus in partial epilepsies as part of the presurgical evaluation. Few studies have explored the possible relation between preoperative SPECT and underlying pathology, or any relation to postsurgical outcome. In this study preoperative ictal and interictal rCBF in relation to the histopathological diagnosis and outcome in a series of 35 children (24 females, 11 males; mean age 9.6 years, age range 11 months to 18 years) who had undergone resective surgery for epilepsy were retrospectively evaluated. A correlation between ictal hyperperfusion and the underlying responsible pathology was shown, with a consistent ictal increase in perfusion in developmental pathologies and Rasmussen's encephalitis, and consistent interictal hypoperfusion in hippocampal sclerosis (HS). No rCBF study parameter appeared to relate to outcome but in the group with HS the best outcome was seen in those with localizing ictal rCBF. The varied group of pathologies from hemispherectomy had excellent outcome but the SPECT findings had little to contribute over the abnormalities detected on MRI. In conclusion, rCBF studies remain a useful presurgical investigation in children with partial epilepsy, especially where HS, cortical dysplasia, or inflammatory disease are the underlying pathology. However, rCBF studies add little to the investigation of children with seizures secondary to benign tumours or cerebral infarcts, or where hemispherectomy is the likely preferred surgical option.

Since December 1995, pediatric renal transplant recipients in our unit have received a DMSA scan as soon as possible post-transplant in order to provide a baseline for comparison in the event of subsequent complications. We retrospectively reviewed the case notes and DMSA scans of the 45 patients who underwent a scan within 9 wk of their transplant to see if pre or peri-transplant factors or post-transplant complications were associated with defects on scanning. Forty percentage of scans had defects. The presence of defects was not associated with potential predisposing factors such as patient or donor age, cadaveric or live donation, cold ischemia time, multiple donor vessels, the use of non-heart beating donors, the mean time to scan, the serum creatinine, or the presence of structural renal tract anomalies predisposing to UTI. However, 87% of patients had complications before the scan, including UTI, rejection, acute tubular necrosis, transplant biopsy and drug toxicity. Children with no clinical complications had a significantly reduced risk of a defect (p = 0.035), while biopsy was associated with the presence of defects (p = 0.0034). Twenty patients had one or more follow up DMSA scans: one patient developed a new focal defect. In conclusion, renal transplant defects are frequently found on DMSA scanning even early after transplantation and are non-specifically associated with many different complications.

Planners are becoming increasingly interested in watershed-based plans as a way to more accurately reflect the natural landscape processes that cross the borders of political jurisdictions. Although developing plans that cross political boundaries is a relatively simple matter, establishing the transboundary authority necessary to implement such plans is often a much different matter. We investigated the regulatory mechanisms under which a watershed-based storm-water management plan could be implemented in the Big Darby Creek, Ohio, USA, a national scenic river currently facing critical threats from nonpoint sediment- and pollutant-loaded storm-water runoff in the rapidly urbanizing portions of the watershed. The watershed encompasses portions of 7 counties, 11 incorporated areas, and 26 townships, each of which has some authority over land use and storm water. The transboundary options explored include creation of a storm-water utility, creating a conservancy district, or an independent approach requiring all jurisdictions in the watershed to simultaneously adopt a series of storm-water ordinances. We evaluated these options on a number of characteristics, including their relative ability to control runoff quality and quantity, the locus of political control and enforcement authority under each, funding considerations, and the likelihood of acceptance given the region's existing political realities. Although a central authority such as a conservancy district or storm-water management district would likely be most effective in protecting water quality, the long tradition of local controls on land use makes this politically infeasible. Thus, we argue that a watershed-based protection plan for the Darby region will require the simultaneous independent approach. The case study of the Big Darby suggests that the successful implementation of watershed-based plans may be more dependent on the plan's political savvy than its technical superiority.

Environmental modeling has long been a recognized part of environmental risk assessment. Traditionally, environmental models have been deterministic models for specific processes over small areas using spatially aggregated subunits for data collection and processing. For an analysis of environmental risk factors on a regional scale, such models are not always appropriate because of uncertainties in the processes, heterogeneity of the environment, and extensive data requirements. Under such circumstances, statistical modeling of the environment can offer useful insights because it deals with a combination of processes and provides a broad view of the degree and signilicance of the factors impacting ecological resources on a regional scale. Using data from the Eastern Cornbelt Plains ecoregion of Ohio, USA, we have developed several statistical models relating anthropogenic activities on the watershed and a set of stream condition variables to the biological quality of stream segments. The effects of land use and instream physical and chemical factors on the biological indicator, the index of biotic integrity, have been studied using nested watersheds as geographic units. The effects of scale and spatial aggregation have been integrated into the model. A geographic information system database was built using Arc/Info® software (Environmental Systems Research Institute, Redlands, CA, USA) for integrating and summarizing data. The results can be used as a screening model to help planners review the potential cumulative impacts of human activities on indicators of fish community structure. Future work will try to account more explicitly for distance decay of pollutants and the effects of underlying geology and soils on variations in biological diversity.

This study examined the relationship between magnetic resonance diffusion imaging and autoradiographic markers of cerebral blood flow (99mTc-hexamethylpropylene amine oxime) and cerebral hypoxia (125I-iodoazomycin arabinoside) in a rat model of stroke. Middle cerebral artery occlusion in the rat was performed using an intraluminal suture approach. Diffusion, hypoxia, and blood flow maps were acquired 2 hr following occlusion, and were compared with T2 images and histology at 7 hr. Two hours following middle cerebral artery occlusion the lesion distributions from the diffusion maps and hypoxic autoradiographs were similar. The blood flow threshold for increased uptake of the hypoxic marker was approximately 34 +/- 7% of the normal flow. The combination of diffusion or hypoxic images with perfusion maps allowed differentiation between four regions: 1) normal tissue; 2) a region of decreased perfusion but normal diffusion and normal uptake of hypoxic marker; 3) a region of decreased perfusion, decreased diffusion and increased uptake of hypoxic marker; 4) a region of decreased perfusion, decreased diffusion and low uptake of hypoxic marker. The areas for increased uptake of hypoxic marker and decreased diffusion are equivalent, indicating similar blood flow thresholds. Regions of oligaemic misery perfusion, ischaemic misery perfusion and lesion core may be delineated with the combination of diffusion or hypoxic images and perfusion maps.

The mammalian intestine contains a complex, dynamic, and spatially diversified society of nonpathogenic bacteria. Very little is known about the factors that help establish host-microbial symbiosis in this open ecosystem. By introducing single genetically manipulatable components of the microflora into germfree mice, simplified model systems have been created that will allow conversations between host and microbe to be heard and understood. Other paradigms of host–microbial symbiosis suggest that these interactions will involve an exchange of biochemical signals between host and symbionts as well as among the bacteria themselves. The integration of molecular microbiology, cell biology, and gnotobiology should provide new insights about how we adapt to a microbial world and reveal the roles played by our indigenous ‘nonpathogenic’ flora. BioEssays20:336-343, 1998. © 1998 John Wiley & Sons, Inc.

BACKGROUND The aim of this study was to determine the long term outcome and toxicities after the administration of 2-chlorodeoxyadenosine (2-CdA) to patients with previously treated, advanced, indolent non-Hodgkin's lymphoma (NHL). METHODS Twenty-two patients (median age, 55 years) with relapsed or refractory low grade NHL (median disease duration, 2.8 years) were treated with 2-CdA by continuous infusion at 0.1 mg/kg/day over 5 or 7 days every 28 days, for a maximum of 6 cycles. RESULTS The overall response rate was 45%. Two patients (9%) achieved a complete response (CR), 8 patients (36%) achieved a partial response, and 12 patients (55%) had no response. The two patients achieving CR have remained in CR for 46 and 38 months, respectively. Freedom from treatment failure at 24 months was 32%. Overall survival at 24 months was 59%. Three patients developed second malignancies: acute myelogenous leukemia (AML), myelodysplastic syndrome, and a cutaneous lymphoproliferative disorder. Fourteen patients have died after a median follow-up of 28 months (range, 3.9-49.2 months) due to progressive NHL (11 patients), infection (2 patients), and AML (1 patient). CONCLUSIONS 2-CdA is an active agent for patients with previously treated, advanced, indolent NHL and may result in lasting remissions. Late complications following treatment may include delayed bacterial, fungal, or viral infection. Determination of whether the second malignancies that occurred in three patients reported herein were related to treatment with 2-CdA will require further study. Cancer 1998;82:957-64. © 1998 American Cancer Society.

Objective The etiology of anorexia nervosa is not fully understood, but is probably multifactorial, including a biological substrate. The purpose of this paper is to investigate the possible underlying biological substrate. Method: Fifteen children and adolescents aged 8–16 years underwent regional cerebral blood blow radioisotope scans. All fulfilled DSM-IV criteria for anorexia nervosa. Three of the girls had a follow-up scan when they had regained their lost weight. Results: Thirteen of the 15 patients had unilateral temporal lobe hypoperfusion, 8 on the left side and 5 on the right. The abnormality persisted in the 3 girls who had a follow-up scan after weight restoration. Discussion: This is the first report of reduced regional cerebral blood flow in childhood-onset anorexia nervosa, and suggests an underlying primary functional abnormality. © 1997 by John Wiley & Sons, Inc. Int J Eat Disord 22: 159–165, 1997.

Background: In recent times there has been a number of newer methods advocated as treatment for bladder outlet obstruction. Prior to embracing these newer technologies, the authors' experiences with conventional transurethral resection of the prostate should be evaluated and compared with those experienced in the newer modalities. The objective was to determine whether a standard transurethral resection of the prostate (TURP) still compared favourably with the newer modalities in terms of duration of stay, duration of catheterization, re-admission rate, re-catheterization rate, cost and long-term results. The results are compared with those of workers whose level of expertise was the best that could be achieved with transurethral needle ablation (TUNA) and laser prostatectomy. Methods: During the 3-year period from September 1992 to September 1995, 575 TURP were carried out in a regional hospital. The total duration of stay, the postoperative duration of stay, the re-catheterization and re-admission rates were assessed and the costs estimated. Results: Transurethral resection of the prostate was shown to compare favourably in terms of the duration of hospital admission and the duration of catheterization, and to have a significantly lower re-catheterization rate and a significantly lower re-admission rate than the newer modalities. Conclusion: Transurethral resection of the prostate is still the method of choice for surgical management of bladder outlet obstruction, and it remains as the gold standard. Having reviewed the results of the newer modalities as carried out by the experts in those fields, it was found that TURP compares favourably with those procedures. From the point of view of duration of stay, duration of catherization, re-admission rate and re-catheterization rate, as well as cost and long-term results, TURP remains as the gold standard and the newer modalities are not believed to be advantageous at this stage.

Purpose: To understand the pathological basis of focal hypoperfusion seen on interictal 99 Tc m hexamethylpropyleneamine oxime (HMPAO) single-photon-emission computed tomography (SPECT) in intractable temporal lobe epilepsy, and to determine why the technique may be misleading in the localization and lateralization of the seizure focus in some cases. Methods: Interictal 99 Tc m HMPAO SPECT and proton magnetic resonance spectroscopy ('H MRS) of the mesial temporal regions were performed in 14 children with intractable temporal lobe epilepsy not caused by a foreign tissue lesion. Results: Hypoperfusion of one temporal lobe ipsilateral to the seizure focus was demonstrated in 10 (71%) of the children; 1 H MRS correctly lateralised in eight of these 10. No asymmetry of perfusion of the anterior temporal regions was seen in the remaining four children; on 'H MRS, three of these were bilaterally abnormal but nonlateralising. Repeated SPECT and 'H MRS in three children demonstrated changes over time, the findings from the two techniques being consistent with each other on both the initial and the repeated scans. Conclusions: Abnormalities demonstrated by 'H MRS correlate well with those seen on interictal SPECT and can help to understand the pathologic basis of these SPECT abnormalities. Furthermore, the presence of bilateral damage can result in an absence of perfusion asymmetry on interictal SPECT.

MyristoylCoA: protein N-myristoyltransferase (NMT) catalyzes the cotranslational covalent attachment of a rare cellular fatty acid, myristate, to the N-terminal Gly residue of a variety of eukaryotic proteins. The myristoyl moiety is often essential for expression of the biological functions for these proteins. Attachment of C14:0 alone provides barely enough hydrophobicity to allow stable association with membranes. The partitioning of N-myrisotylproteins is therefore often modulated by "switches" that function through additional covalent or noncovalent modifications. Candida albicans, the principal cause of systemic fungal infection in immunocompromised humans, contains a single NMT gene that is essential for its viability. The functional properties of the acylCoA binding site of human and C. albicans NMT are very similar. However, there are distinct differences in their peptide binding sites. An ADP ribosylation factor (Arf) is included among the few cellular protein substrates of the fungal enzyme. Alanine scanning mutagenesis of an octapeptide derived from an N-terminal Arf sequence (GLYASKLS-NH2) disclosed that Gly1, Ser5, and Lys6 play predominant roles in binding. ALYASKLS-NH2 is an inhibitor competitive for peptide [Ki(app) = 15.3 +/- 6.4 microM] and noncompetitive for myristoylCoA. Remarkably, replacement of the N-terminal tetrapeptide with an 11-aminoundecanoyl group results in a competitive inhibitor (11-aminoundecanoyl-SKLS-NH2) that is approximately 40-fold more potent [Ki(app) = 0.40 +/- 0.03 microM] than the starting octapeptide. Removal of Leu-Ser from the C-terminus generates a competitive dipeptide inhibitor (11-aminoundecanoyl-SK-NH2) with a Ki(app) of 11.7 +/- 0.4 microM, equivalent to that of the starting octapeptide. A derivative dipeptide inhibitor containing a C-terminal N-cyclohexylethyl lysinamide moiety has the advantage of being more potent (IC50 = 0.11 +/- 0.03 microM) and resistant to digestion by cellular carboxypeptidases. Rigidifying the flexible aminoundecanoyl chain results in very potent general NMT inhibitors (IC50 = 40-50 nM). Substituting a 2-methylimidazole for the N-terminal amine and adding a benzylic alpha-methyl group with R stereochemistry to the rigidifying element produces even more potent inhibitors (IC50 = 20-50 nM) that are up to 500-fold selective for the fungal compared to human enzyme. A related less potent member of this series of compounds is fungistatic. Its growth inhibitory effects are associated with a reduction in cellular protein N-myristoylation, judged using cellular Arf as a reporter. These studies establish that NMT is a new antifungal target.

To what extent have state departments of education developed policies for testing limited English proficiency students with standardized achievement tests? What are some of the relationships between the development of these testing policies and the establishment of bilingual education in the states? What work still lies ahead in standardized achievement testing of limited English proficient students?

MyristoylCoA:protein N-myristoyltransferase (Nmt) catalyses the co-translational, covalent attachment of myristate (C14:0) to the amino-terminal glycine residue of a number of eukaryotic proteins involved in cellular growth and signal transduction. The NMT1 gene is essential for vegetative growth of Saccharomyces cerevisiae. Studies were carried out to determine if Nmt is also essential for vegetative growth of the pathogenic fungus Candida albicans. A strain of C. albicans was constructed in which one copy of NMT was partially deleted and disrupted. A Gly-447--Asp mutation was introduced into the second NMT allele. This mutation produced marked reductions in catalytic efficiency at 24 and 37 degrees C, as judged by in vitro kinetic studies of the wild-type and mutant enzymes which had been expressed in, and purified from, Escherichia coli. The growth characteristics of isogenic NMT/NMT, NMT/delta nmt, and nmt delta/nmtG447D C. albicans strains were assessed under a variety of conditions. Only the nmt delta/nmtG447D strain required myristate for growth. This was true at both 24 and 37 degrees C. Palmitate could not substitute for myristate. Incubation of nmt delta/nmtG447D cells at 37 degrees C in the absence of myristate resulted in cell death as observed by the inability to form colonies on media supplemented with 500 microM myristate. Studies in an immunosuppressed-mouse model of C. albicans infection revealed that the NMT/delta nmt strain produced 100% lethality within 7 d after intravenous administration while the isogenic nmt delta/nmtG447G strain produced no deaths even after 21 d. These observations establish that Nmt is essential for vegetative growth of C. albicans and suggest that inhibitors of this acyltransferase may be therapeutically useful fungicidal agents.

Background. Recent data have suggested that there are no differences among various anthracycline-based chemotherapy regimens including cyclophosphamide, vincristine, methotrexate, and prednisone (CHOP), methotrexate, calcium leucovorin, bleomycin, doxorubicin, cyclophosphamide, and dexamethasone (m-BACOD), methotrexate, doxorubicin, cyclophosphamide, vincristine, prednisone, and bleomycin (MACOP-B), and cyclophosphamide, doxorubicin, etoposide, prednisone, cytosine arabinoside, bleomycin, vincristine, methotrexate, and calcium leucovorin (PROMACE-cyta-BOM) in patients with diffuse aggressive lymphomas. Because outcome appears to depend on certain prognostic factors, risk groups can be identified. Therefore, these prognostic factors were examined for their correlations with survival, time-to-treatment failure (TTF), and disease free survival (DFS) in a group of patients with diffuse aggressive non-Hodgkin's lymphoma who were treated on a single randomized trial with either CHOP or m-BACOD. Methods. From July 1984 to January 1988, 392 patients with diffuse large cell or diffuse mixed non-Hodgkin's lymphoma were enrolled in an Intergroup study and were randomly assigned to treatment with CHOP or m-BACOD chemotherapy. Of these, 325 were eligible for response, toxicity, and survival analysis, and the results were reported. The survival and TTF results now have been updated. The 286 patients who had lactic dehydrogenase (LDH) data available at study entry were analyzed for prognostic features according to the International Index criteria and using Martingale Residuals for proportional hazards regression. Results. There were no differences in survival, TTF, and disease free survival between groups of patients treated with either CHOP or m-BACOD. In addition, analysis using the International Index criteria confirmed that patients in the lower risk groups had better outcome than patients in the higher risk groups (5-year survival was 56 and 58% for low and low/intermediate risk groups, respectively, and 37% and 31% for high/intermediate and high risk groups, respectively). There were, however, no differences in survival, disease free survival, or TTF within any risk group when treatment with CHOP or m-BACOD were compared. In addition, analysis using Martingale residuals for proportional hazards regression identified LDH level (< 3 × normal) as an important prognostic factor that was not captured by the International Index. Thus, 5-year survival was 57% if LDH was normal or below, 42% if LDH was 1-3 × normal, and 21% if LDH was < 3 × normal. Conclusion. In patients with advanced diffuse large cell or diffuse mixed non-Hodgkin's lymphoma, there are no differences in outcome that can be attributed to treatment with CHOP vs. m-BACOD; this holds for any prognostic group identified by the International Index. However, the level of LDH at time of study entry is an important prognostic factor that is predictive of survival and may help to identify candidates for future clinical trials. Cancer 1995; 75:865-73.

The cost of a transurethral resection of the prostate is of considerable concern to the community. More of these procedures are being performed as the number of patients in the aged population increases. The costs of wages and salaries, purchase of equipment and depreciation, stationery, linen, investigations (pathology) and pharmaceuticals are compared with the bed charges (as charged to a private patient), the cost per inpatient day and the cost per inpatient treated, which is calculated from the operating fund budget expenditure of The Bendigo Hospital. The cost per diagnosis related group (DRG) 336 (defined as: transurethral prostatectomy, age greater than 69 and/or complication/co-morbidity; mean length of stay 7.0 relative weight = 0.9869) and DRG 337 (defined as: transurethral prostatectomy, age less than 70 without complication/co-morbidity; mean length of stay 5.8; relative weight = 0.7788) are compared with the figures for a similar procedure in 1987 in a United States hospital and extrapolated, by the use of the Consumer Price Index, to 1992 levels. The findings demonstrate that transurethral resection of the prostate as costed in this hospital compares very favourably with that in a US hospital, and favourably from the point of view of health care costs.

The aim of the present series of experiments was to investigate the effect of the size of follicle from which the oocytes originate on their subsequent in vitro developmental ability. Ovarian follicles were isolated and grouped according to size (2-6 mm,6 mm). Primary oocytes were carefully liberated and grouped according to morphology into one of five categories: denuded; expanded; with two or three layers of cumulus; with four or five layers; and with many (six or more) layers. Following in vitro maturation (IVM), fertilization (IVF), and culture (IVC), more oocytes with many layers of cumulus (P0.01, 70.2%, 73/104 vs. 46.8%, 87/186, respectively) and a higher proportion of blastocysts were obtained from follicles6 mm compared to 2-6 mm follicles (P0.01, 65.9%, 60/91 from6 mm follicles vs. 34.3%, 34/99 from 2-6 mm follicles, respectively). Use of follicular fluid (BFF) from follicles of different sizes in the IVM medium did not significantly increase the cleavage rate or blastocyst yield compared to controls. Administration of porcine follicle-stimulating hormone (pFSH) to donors prior to slaughter was investigated as a possible means of increasing the number of larger sized follicles in the ovaries and, thereby, the quality of the recovered oocytes. It was found that administration of six injections of pFSH beginning 3 days prior to slaughter resulted in a significant increase (P0.001) in the proportion of follicles6 mm in diameter (31.6%) compared to that in nontreated controls (6.6%) and to animals that received only four injection groups (9.4%).(ABSTRACT TRUNCATED AT 250 WORDS)

Background The epidophyllotoxin VM 26 has been shown to have single-agent activity in patients with diffuse aggressive lymphoma. In an attempt to determine its activity in combination with other agents known to be effective in lymphoma, a Phase II trial of a novel chemotherapy regimen was conducted. Methods Forty-two patients with Stages II, III, and IV diffuse aggressive lymphoma were treated with teniposide, doxorubicin, prednisone, cyclophosphamide, vincristine, and bleomycin (PA Ten-CPOB) as part of a Phase II trial of the Eastern Cooperative Oncology Group. Fifty-five percent of patients had Stage IV disease, 21% Stage III, and 24% Stage II. Results The overall complete response rate was 64%. Of the 27 patients who had complete response, 19 (70% [45% of the entire group]) are still alive without disease (median follow-up, 5.7 years). No patient had a follow-up time of less than 5 years. On examination of factors that were predictive of survival and relapse, it was found that age younger than 60 years was predictive of long-term survival, as 76% of patients younger than 60 years of age were alive without disease. Forty patients were evaluable for toxicity. There were four (10%) early deaths, and six patients (15%) had Grade 4 hematologic toxicity. Conclusions This alternating combination chemotherapy regimen (PA Ten-CPOB) results in a complete response rate comparable to what has been reported previously in the literature, but 45% of patients in this series demonstrated long-term disease-free survival. When patients younger than 60 years of age with follow-up times of at least 5 years were considered, disease-free survival was 76%.

Mantle cell lymphoma (MCL) is characterized by translocation t(11;14)(q13;q32), aggressive clinical behaviour, and poor patient outcomes following conventional chemotherapy. New treatment approaches are needed that target novel biological pathways. All trans retinoic acid (ATRA) is a key retinoid that acts through nuclear receptors that function as ligand-inducible transcription factors. The present study evaluated cell killing effects of ATRA-enriched nanoscale delivery particles, termed nanodisks (ND), on MCL cell lines. Results show that ATRA-ND induced cell death more effectively than naked ATRA (dimethyl sulphoxide) or empty ND. ATRA-ND induced reactive oxygen species (ROS) generation to a greater extent than naked ATRA. The antioxidant, N-acetylcysteine, inhibited ATRA-ND induced apoptosis. Compared to naked ATRA, ATRA-ND enhanced G1 growth arrest, up-regulated p21and p27, and down regulated cyclin D1. At ATRA concentrations that induced apoptosis, expression levels of retinoic acid receptor-alpha (RARalpha) and retinoid X receptor-gamma (RXRgamma) were increased. Compared to naked ATRA, ATRA-ND significantly stimulated transcriptional activity of RARA in a model carcinoma cell line. Furthermore, the RAR antagonist, Ro 41-5253, inhibited ATRA-ND induced ROS generation and prevented ATRA-ND induced cell growth arrest and apoptosis. In summary, incorporation of ATRA into ND enhanced the biological activity of this retinoid in cell culture models of MCL.