Early MRI Predictors of Relapse in Primary Central Nervous System Lymphoma Treated with MATRix Immunochemotherapy

Primary Central Nervous System Lymphoma (PCNSL) is a highly malignant brain tumour. We investigated dynamic changes in tumour volume and apparent diffusion coefficient (ADC) measurements for predicting outcome following treatment with MATRix chemotherapy in PCNSL. Patients treated with MATRix (n = 38) underwent T1 contrast-enhanced (T1CE) and diffusion-weighted imaging (DWI) before treatment, after two cycles and after four cycles of chemotherapy. Response was assessed using the International PCNSL Collaborative Group (IPCG) imaging criteria. ADC histogram parameters and T1CE tumour volumes were compared among response groups, using one-way ANOVA testing. Logistic regression was performed to examine those imaging parameters predictive of response. Response after two cycles of chemotherapy differed from response after four cycles; of the six patients with progressive disease (PD) after four cycles of treatment, two (33%) had demonstrated a partial response (PR) or complete response (CR) after two cycles. ADC_mean at baseline, T1CE at baseline and T1CE percentage volume change differed between response groups (0.005 < p < 0.038) and were predictive of MATRix treatment response (area under the curve: 0.672-0.854). Baseline ADC and T1CE metrics are potential biomarkers for risk stratification of PCNSL patients early during remission induction therapy with MATRix. Standard interim response assessment (after two cycles) according to IPCG imaging criteria does not reliably predict early disease progression in the context of a conventional treatment approach.

Increasing COVID-19 Vaccination in the United States: Projected Impact on Cases, Hospitalizations, and Deaths by Age and Racial Group

Objectives

Minority populations in the United States face a disproportionate burden of illness from COVID-19 infection and have lower vaccination rates compared with other groups. This study estimated the equity implications of increased COVID-19 vaccination in the United States, with a focus on the number of cases, hospitalizations, and deaths avoided.

Study design

This was an observational real-world modeling study.

Methods

Data from the Centers for Disease Control and Prevention (CDC) were used to identify the remaining unvaccinated US population by county, age, and race as of October 22, 2021. The number of COVID-19 cases, hospitalizations, and deaths avoided were calculated based on case incidence and death data from the CDC, along with data on race- and age-specific hospitalization multipliers, under a scenario in which half of the remaining unvaccinated population per county, race, and age group obtained a full vaccine regimen.

Results

Vaccinating half of the remaining unvaccinated population in each age and race subgroup within counties would result in an estimated 22.09 million COVID-19 cases avoided, 1.38 million hospitalizations avoided, and 150,000 deaths avoided over 12 months. Some minority groups, particularly Black and Hispanic/Latino populations, were projected to experience substantial benefits from increased vaccination rates as they face both lower vaccination rates and worse outcomes if infected with COVID-19.

Conclusions

Increasing COVID-19 vaccination in the United States not only benefits the population as a whole but also serves as a potentially useful lever to reduce the disproportionate burden of COVID-19 illness among minority populations.

Cyclic Thiosulfonates for Thiol-Mediated Uptake: Cascade Exchangers, Transporters, Inhibitors

Thiol-mediated uptake is emerging as a powerful method to penetrate cells. Cyclic oligochalcogenides (COCs) have been identified as privileged scaffolds to enable and inhibit thiol-mediated uptake because they can act as dynamic covalent cascade exchangers, i.e., every exchange produces a new, covalently tethered exchanger. In this study, our focus is on the essentially unexplored COCs of higher oxidation levels. Quantitative characterization of the underlying dynamic covalent exchange cascades reveals that the initial ring opening of cyclic thiosulfonates (CTOs) proceeds at a high speed even at a low pH. The released sulfinates exchange with disulfides in aprotic but much less in protic environments. Hydrophobic domains were thus introduced to direct CTOs into hydrophobic pockets to enhance their reactivity. Equipped with such directing groups, fluorescently labeled CTOs entered the cytosol of living cells more efficiently than the popular asparagusic acid. Added as competitive agents, CTOs inhibit the uptake of various COC transporters and SARS-CoV-2 lentivectors. Orthogonal trends found with different transporters support the existence of multiple cellular partners to account for the diverse expressions of thiol-mediated uptake. Dominant self-inhibition and high activity of dimers imply selective and synergistic exchange in hydrophobic pockets as distinguishing characteristics of thiol-mediated uptake with CTOs. The best CTO dimers with hydrophobic directing groups inhibit the cellular entry of SARS-CoV-2 lentivectors with an IC₅₀ significantly lower than the previous best CTO, below the 10 μM threshold and better than ebselen. Taken together, these results identify CTOs as an intriguing motif for use in cytosolic delivery, as inhibitors of lentivector entry, and for the evolution of dynamic covalent networks in the broadest sense, with reactivity-based selectivity of cascade exchange emerging as a distinguishing characteristic that deserves further attention.

Predictors of Change in Skin Intrinsic Fluorescence in Type 1 Diabetes: The Epidemiology of Diabetes Complications Study

BACKGROUND

Skin intrinsic fluorescent (SIF) scores are indirect measures of advanced glycation end-products (AGEs). SIF scores are cross-sectionally associated with type 1 diabetes (T1D) complications such as increased albumin excretion rate (AER), coronary artery calcification (CAC) and neuropathy. We assessed predictors of SIF score change in those with T1D.

METHODS

Data from the 30-year longitudinal Epidemiology of Diabetes Complications (EDC) study of childhood-onset T1D were used to assess AGEs measured with a SIF score produced by the SCOUT DS® device. SIF scores were assessed twice in 83 participants: between 2007-08 and again between 2010-14. Regression analyses were used to assess independent predictors of SIF score change.

RESULTS

At baseline, mean age was 47.9 ± 6.9 years, diabetes duration was 36.7 ± 6.4 years, and median glycosylated hemoglobin (HbA1c) was 7.1 (interquartile range: 6.5, 8.5). During a mean follow-up of 5.2 ± 0.9 years, mean change in SIF score was 2.9 ± 2.8 arbitrary units. In multivariable linear regression models, log HbA1c (P < 0.001), log estimated glomerular filtration rate (eGFR) (P < 0.001), overt nephropathy (defined as AER ≥ 200 µg/min, P = 0.06), and multiple daily insulin shots/pump use (MDI) exposure years (P = 0.02) were independent predictors of SIF score change.

CONCLUSIONS

Increases in SIF score over 5 years were related to increased glycemic levels and decreased kidney function (eGFR). MDI and glomerular damage were related to a decreased SIF score. This is one of the first studies with repeated SIF assessments in T1D and provides unique, albeit preliminary, insight about these associations.

Skin intrinsic fluorescence scores are a predictor of all-cause mortality risk in type 1 diabetes: The Epidemiology of Diabetes Complications study

AIMS

We assessed the association of skin intrinsic fluorescence (SIF) scores, as a measure of advanced glycation end-products (AGE), with all-cause mortality in type 1 diabetes (T1D).

METHODS

This is an observational retrospective study of a convenience sample from the Epidemiology of Diabetes Complications (EDC) study. AGEs were measured with a SIF score between 2007 and 2014; vital status was assessed in 2020.

RESULTS

Among 245 participants, mean age was 48.6 ± 7.4 years, median diabetes duration was 39.5 years (IQR: 34.2, 44.9), and 53.5% were female. Compared to survivors, the deceased (n = 20) were older, with higher SIF scores, longer diabetes duration, lower body mass index (BMI), and an adverse risk factor profile (all p≤0.05). Univariate Cox regression showed a marginal association between SIF score and mortality (HR: 1.1, 95% CI 0.9-1.2, p = 0.06), which persisted after adjustment for multiple daily insulin shots/pump (MDI) use (HR: 1.1, 95% CI 1.0-1.2, p = 0.04). This association was attenuated after adjustment for T1D duration, A_1c months, or estimated glomerular filtration rate (eGFR).

CONCLUSIONS

In individuals with long duration T1D, SIF scores adjusted for MDI predicted all-cause mortality, although this association was attenuated after adjustments. Given the nature of sampling and small number of events, our findings require replication.

The timed barium swallow and its relationship to symptoms in achalasia: Analysis of surface area and emptying rate

BACKGROUND

Timed barium swallow (TBS) is used to objectively measure response following achalasia therapy; however, findings can be discordant with symptoms. We hypothesized that measurement of surface area of the residual barium column would improve its utility in measuring outcome.

METHODS

In a single-center cohort, achalasia patients undergoing therapy between September 2015-2016 who had TBS were included. Four metrics of emptying were studied: Post-therapy residual barium (a) absolute height and (b) surface area and percentage reduction in (c) residual height (%H) and (d) surface area (%SA) compared to pretherapy. Metrics were evaluated against symptom response (Eckardt score).

KEY RESULTS

Twenty-four achalasics (median age 43 year; 13 males) were included; 14 received pneumatic dilatation, and 10 had peroral endoscopic myotomy. Treatment resulted in significant reduction in median Eckardt score (7 to 1; P = .03), mean residual barium column height (14.7 ± 8.7 to 7.9 ± 6.0 cm; P = .01) and surface area (52.7 ± 43.5 to 24.5 ± 23.6 cm² ; P = .02). There were 4 (17%) initial non-responders (Eckardt > 3). % SA was best at discriminating between responders and non-responders (area under curve 0.85 ± 0.08; sensitivity 100%, specificity 80%). Concordance with symptomatic response following therapy was 83% when using 45% as the cutoff for surface area reduction compared to pretherapy. Eight patients whose static barium height was discordant with symptoms became concordant when % SA was used as a measure of response.

CONCLUSIONS & INFERENCES

Change in barium surface area is a superior measure of esophageal emptying and better correlates with treatment response than the conventional 5-minute barium height in defining objective response to achalasia therapy.

World Health Organization Grade II/III Glioma Molecular Status: Prediction by MRI Morphologic Features and Apparent Diffusion Coefficient

Background A readily implemented MRI biomarker for glioma genotyping is currently lacking. Purpose To evaluate clinically available MRI parameters for predicting isocitrate dehydrogenase (IDH) status in patients with glioma. Materials and Methods In this retrospective study of patients studied from July 2008 to February 2019, untreated World Health Organization (WHO) grade II/III gliomas were analyzed by three neuroradiologists blinded to tissue results. Apparent diffusion coefficient (ADC) minimum (ADC_min) and mean (ADC_mean) regions of interest were defined in tumor and normal appearing white matter (ADC_NAWM). A visual rating of anatomic features (T1 weighted, T1 weighted with contrast enhancement, T2 weighted, and fluid-attenuated inversion recovery) was performed. Interobserver comparison (intraclass correlation coefficient and Cohen κ) was followed by nonparametric (Kruskal-Wallis analysis of variance) testing of associations between ADC metrics and glioma genotypes, including Bonferroni correction for multiple testing. Descriptors with sufficient concordance (intraclass correlation coefficient, >0.8; κ > 0.6) underwent univariable analysis. Predictive variables (P < .05) were entered into a multivariable logistic regression and tested in an additional test sample of patients with glioma. Results The study included 290 patients (median age, 40 years; interquartile range, 33-52 years; 169 male patients) with 82 IDH wild-type, 107 IDH mutant/1p19q intact, and 101 IDH mutant/1p19q codeleted gliomas. Two predictive models incorporating ADC_mean-to-ADC_NAWM ratio, age, and morphologic characteristics, with model A mandating calcification result and model B recording cyst formation, classified tumor type with areas under the receiver operating characteristic curve of 0.94 (95% confidence interval [CI]: 0.91, 0.97) and 0.96 (95% CI: 0.93, 0.98), respectively. In the test sample of 49 gliomas (nine IDH wild type, 21 IDH mutant/1p19q intact, and 19 IDH mutant/1p19q codeleted), the classification accuracy was 40 of 49 gliomas (82%; 95% CI: 71%, 92%) for model A and 42 of 49 gliomas (86%; 95% CI: 76%, 96%) for model B. Conclusion Two algorithms that incorporated apparent diffusion coefficient values, age, and tumor morphologic characteristics predicted isocitrate dehydrogenase status in World Health Organization grade II/III gliomas on the basis of standard clinical MRI sequences alone. © RSNA, 2020 Online supplemental material is available for this article.

Oxidative Stress and Cardiovascular Risk in Type 1 Diabetes Mellitus: Insights From the DCCT/EDIC Study

Background

Hyperglycemia leading to increased oxidative stress is implicated in the increased risk for the development of macrovascular and microvascular complications in patients with type 1 diabetes mellitus.

Methods and Results

A random subcohort of 349 participants was selected from the DCCT / EDIC (Diabetes Control and Complications Trial/Epidemiology of Diabetes Interventions and Complications) cohort. This included 320 controls and 29 cardiovascular disease cases that were augmented with 98 additional known cases to yield a case cohort of 447 participants (320 controls, 127 cases). Biosamples from DCCT baseline, year 1, and closeout of DCCT , and 1 to 2 years post‐ DCCT ( EDIC years 1 and 2) were measured for markers of oxidative stress, including plasma myeloperoxidase, paraoxonase activity, urinary F 2α isoprostanes, and its metabolite, 2,3 dinor‐8 iso prostaglandin F 2α . Following adjustment for glycated hemoblobin and weighting the observations inversely proportional to the sampling selection probabilities, higher paraoxonase activity, reflective of antioxidant activity, and 2,3 dinor‐8 iso prostaglandin F 2α , an oxidative marker, were significantly associated with lower risk of cardiovascular disease (−4.5% risk for 10% higher paraoxonase, P <0.003; −5.3% risk for 10% higher 2,3 dinor‐8 iso prostaglandin F 2α , P =0.0092). In contrast, the oxidative markers myeloperoxidase and F 2α isoprostanes were not significantly associated with cardiovascular disease after adjustment for glycated hemoblobin. There were no significant differences between DCCT intensive and conventional treatment groups in the change in all biomarkers across time segments.

Conclusions

Heightened antioxidant activity (rather than diminished oxidative stress markers) is associated with lower cardiovascular disease risk in type 1 diabetes mellitus, but these biomarkers did not change over time with intensification of glycemic control.

Clinical Trial Registration

URL : https://www.clinicaltrials.gov . Unique identifiers: NCT 00360815 and NCT 00360893.

New Locus for Skin Intrinsic Fluorescence in Type 1 Diabetes Also Associated With Blood and Skin Glycated Proteins

Skin fluorescence (SF) noninvasively measures advanced glycation end products (AGEs) in the skin and is a risk indicator for diabetes complications. N-acetyltransferase 2 (NAT2) is the only known locus influencing SF. We aimed to identify additional genetic loci influencing SF in type 1 diabetes (T1D) through a meta-analysis of genome-wide association studies (N = 1,359) including Diabetes Control and Complications Trial/Epidemiology of Diabetes Interventions and Complications (DCCT/EDIC) and Wisconsin Epidemiologic Study of Diabetic Retinopathy (WESDR). A locus on chromosome 1, rs7533564 (P = 1.9 × 10(-9)), was associated with skin intrinsic fluorescence measured by SCOUT DS (excitation 375 nm, emission 435-655 nm), which remained significant after adjustment for time-weighted HbA1c (P = 1.7 × 10(-8)). rs7533564 was associated with mean HbA1c in meta-analysis (P = 0.0225), mean glycated albumin (P = 0.0029), and glyoxal hydroimidazolones (P = 0.049), an AGE measured in skin biopsy collagen, in DCCT. rs7533564 was not associated with diabetes complications in DCCT/EDIC or with SF in subjects without diabetes (nondiabetic [ND]) (N = 8,721). In conclusion, we identified a new locus associated with SF in T1D subjects that did not show similar effect in ND subjects, suggesting a diabetes-specific effect. This association needs to be investigated in type 2 diabetes.

Improving Immunization Coverage through Budgeted Microplans and Sub-national Performance Agreements: Early Experience from Cambodia

In recent years, Cambodia has demonstrated significant success in specific aspects of immunization with gains through campaign efforts in measles control and polio eradication. In contrast, routine immunization rates have failed to improve over the last five years. In response, the National Immunization Program of the Ministry of Health developed a coverage improvement planning (CIP) process. This paper describes the CIP process in Cambodia, including identified barriers to and strategies for improving coverage. Immunization coverage rose in 8 of 10 pilot districts in the year following the introduction of CIP in 2003. The mean increase in DPT3 coverage across pilot districts on an annual basis was 16%, which provides encouraging early evidence for the effectiveness of the intervention. Factors associated with success in coverage improvement included: (1) development of a needs-based micro-plan, (2) application of performance-based contracting between levels of management, (3) investment in social mobilization, (4) securing finance for health outreach programs and (5) strengthened monitoring systems. Lessons learned will guide program expansion to improve immunization coverage nationally.

Caffeine Consumption Contributes to Skin Intrinsic Fluorescence in Type 1 Diabetes

BACKGROUND

A variant (rs1495741) in the gene for the N-acetyltransferase 2 (NAT2) protein is associated with skin intrinsic fluorescence (SIF), a noninvasive measure of advanced glycation end products and other fluorophores in the skin. Because NAT2 is involved in caffeine metabolism, we aimed to determine whether caffeine consumption is associated with SIF and whether rs1495741 is associated with SIF independently of caffeine.

MATERIALS AND METHODS

SIF was measured in 1,181 participants with type 1 diabetes from the Epidemiology of Diabetes Interventions and Complications study. Two measures of SIF were used: SIF1, using a 375-nm excitation light-emitting diode (LED), and SIF14 (456-nm LED). Food frequency questionnaires were used to estimate mean caffeine intake. To establish replication, we examined a second type 1 diabetes cohort.

RESULTS

Higher caffeine intake was significantly associated with higher SIF1(LED 375 nm[0.6, 0.2]) (P=2×10(-32)) and SIF14L(ED 456 nm[0.4, 0.8]) (P=7×10(-31)) and accounted for 4% of the variance in each after adjusting for covariates. When analyzed together, caffeine intake and rs1495741 both remained highly significantly associated with SIF1(LED 375 nm[0.6, 0.2]) and SIF14(LED 456 nm[0.4, 0.8]). Mean caffeinated coffee intake was also positively associated with SIF1(LED 375 nm[0.6, 0.2]) (P=9×10(-12)) and SIF14(LED 456 nm[0.4, 0.8]) (P=4×10(-12)), but no association was observed for decaffeinated coffee intake. Finally, caffeine was also positively associated with SIF1(LED 375 nm[0.6, 0.2]) and SIF14(LED 456 nm[0.4, 0.8]) (P<0.0001) in the replication cohort.

CONCLUSIONS

Caffeine contributes to SIF. The effect of rs1495741 on SIF appears to be partially independent of caffeine consumption. Because SIF and coffee intake are each associated with cardiovascular disease, our findings suggest that accounting for coffee and/or caffeine intake may improve risk prediction models for SIF and cardiovascular disease in individuals with diabetes.

Dietary HMB and β-alanine co-supplementation does not improve in situ muscle function in sedentary, aged male rats

This study evaluated the effects of dietary β-hydroxy-β-methylbutyrate (HMB) combined with β-alanine (β-Ala) in sedentary, aged male rats. It has been suggested that dietary HMB or β-Ala supplementation may mitigate age-related declines in muscle strength and fatigue resistance. A total of 20 aged Sprague-Dawley rats were studied. At age 20 months, 10 rats were administered a control, purified diet and 10 rats were administered a purified diet supplemented with both HMB and β-Ala (HMB+β-Ala) for 8 weeks (approximately equivalent to 3 and 2.4 g per day human dose). We measured medial gastrocnemius (MG) size, force, fatigability, and myosin composition. We also evaluated an array of protein markers related to muscle mitochondria, protein synthesis and breakdown, and autophagy. HMB+β-Ala had no significant effects on body weight, MG mass, force or fatigability, myosin composition, or muscle quality. Compared with control rats, those fed HMB+β-Ala exhibited a reduced (41%, P = 0.039) expression of muscle RING-finger protein 1 (MURF1), a common marker of protein degradation. Muscle from rats fed HMB+β-Ala also exhibited a 45% reduction (P = 0.023) in p70s6K phosphorylation following fatiguing stimulation. These data suggest that HMB+β-Ala at the dose studied may reduce muscle protein breakdown by reducing MURF1 expression, but has minimal effects on muscle function in this model of uncomplicated aging. They do not, however, rule out potential benefits of HMB+β-Ala co-supplementation at other doses or durations of supplementation in combination with exercise or in situations where extreme muscle protein breakdown and loss of mass occur (e.g., bedrest, cachexia, failure-to-thrive).

Epidemiology of Dysglycemia in Pregnant Oklahoma American Indian Women

CONTEXT

Minority communities are disproportionately affected by diabetes, and minority women are at an increased risk for glucose intolerance (dysglycemia) during pregnancy.

OBJECTIVES

In pregnant American Indian women, the objectives of the study were to use current criteria to estimate the prevalence of first-trimester (Tr1) dysglycemia and second-trimester (Tr2) incidence of gestational diabetes mellitus (GDM) and to explore new candidate measures and identify associated clinical factors.

DESIGN

This was a prospective cohort study. In Tr1 we performed a 75-g, 2-hour oral glucose tolerance test (OGTT) and glycated hemoglobin (HbA1c) to determine the following: fasting insulin; homeostasis model assessment of insulin resistance; serum 1,5-anhydroglucitol; noninvasive skin autofluorescence (SCOUT). We defined dysglycemia by American Diabetes Association and Endocrine Society criteria and as HbA1c of 5.7% or greater. In Tr2 in an available subset, we performed a repeat OGTT and SCOUT.

PARTICIPANTS

Pregnant American Indian women (n = 244 at Tr1; n = 114 at Tr2) participated in the study.

OUTCOMES

The prevalence of dysglycemia at Tr1 and incidence of GDM at Tr2 were measured.

RESULTS

At Tr1, one woman had overt diabetes; 36 (15%) had impaired glucose tolerance (American Diabetes Association criteria and/or abnormal HbA1c) and 59 (24%) had GDM-Tr1 (Endocrine Society criteria). Overall, 74 (30%) had some form of dysglycemia. Associated factors were body mass index, hypertension, waist/hip circumferences, SCOUT score, fasting insulin, and homeostasis model assessment of insulin resistance. At Tr2, 114 of the Tr1 cohort underwent a repeat OGTT and SCOUT, and 26 (23%) had GDM. GDM-Tr2 was associated with increased SCOUT scores (P = .029) and Tr1 body mass index, waist/hip circumferences, diastolic blood pressure, fasting insulin, and triglyceride levels. Overall, dysglycemia at Tr1 and/or Tr2 affected 38% of the women.

CONCLUSIONS

Dysglycemia at some point during pregnancy was common among American Indian women. It was associated with features of insulin resistance and may confer long-term health risks for mother and child.

Correlation of advanced glycation endproducts estimated from skin fluorescence in first-degree relatives: the impact of adjustment for skin pigmentation

The objective was to assess the relationship of skin advanced glycation endproducts (AGEs) between first-degree relatives estimated from skin fluorescence (SF) after adjustment for skin pigmentation. SF was excited by LEDs centered at 375, 405, and 420 nm from children with type 1 diabetes and their mothers. Data were adjusted to generate measures of skin intrinsic fluorescence (SIF) at the various excitation wavelengths, using 2 different pairs of correction coefficients for excitation (kx) and emission (km): kx = 0.5, km = 0.5 (not associated with skin pigmentation) and kx = 1.0, km = 0.0 (strongly associated with skin pigmentation). Pearson correlation analysis was performed, as well as a multiple variable analysis with maternal SIF adjusted for the effects of maternal age and race. There were 50 matched pairs of children and their mothers. Children were 13.3 ± 3.7 years of age and there were 19 boys/31 girls and 15 black/35 white. Mothers were 41.8 ± 6.8 years of age. The age of mother and child was highly correlated, r = .64, P < .0001. In Pearson correlation analysis, child's SIF (kx = 1.0, km = 0.0) the had strongest association with maternal SIF, while with SIF (kx = 0.5, km = 0.5) there was a trend for association. In the multiple variable model child SIF was associated with maternal SIF for all corrections and wavelengths but was stronger for kx = 1.0, km = 0.0. Even after adjustment for skin pigmentation and race, correlation of SIF between family members persists, suggesting that other genetic and/or environmental factors shared by parent and child may influence estimated skin AGEs.

Skin advanced glycation endproducts are elevated at onset of type 1 diabetes in youth

OBJECTIVES

To compare skin advanced glycation endproducts (AGEs) in children at onset of type 1 diabetes with children without diabetes.

STUDY DESIGN

Skin AGEs (sAGEs) were estimated by measurement of skin intrinsic fluorescence (SIF) at diagnosis of type 1 diabetes (NewD; n=47, F=45%, M=55%, Age=10±3.7) and in youth without diabetes (NoD; n=112, F=53%, M=47%, Age=10.4±4.8). HCO₃, pH, pCO₂, glucose level, and HbA₁c effect on SIF was evaluated in NewD patients.

RESULTS

SIF at 405 nm and 420 nm excitation were higher (p=0.03) in NewD children compared to NoD. HCO₃, pH, pCO₂, glucose, and HbA₁c were not associated with SIF levels.

CONCLUSIONS

Despite the short duration of untreated diabetes, sAGEs were higher in children with NewD compared to children with NoD. Further study will be needed to determine whether early accumulation of sAGEs is associated with higher risk for development and progression of complications.

Interictal psychosis following temporal lobe surgery: dentate gyrus pathology

BACKGROUND

De novo interictal psychosis, albeit uncommon, can develop in patients following temporal lobe surgery for epilepsy. Pathological alterations of the dentate gyrus, including cytoarchitectural changes, immaturity and axonal reorganization that occur in epilepsy, may also underpin co-morbid psychiatric disorders. Our aim was to study candidate pathways that may be associated with the development of interictal psychosis post-operatively in patients with hippocampal sclerosis (HS).

METHOD

A total of 11 patients with HS who developed interictal psychosis (HS-P) post-operatively were compared with a matched surgical HS group without psychosis (HS-NP). Resected tissues were investigated for the extent of granule cell dispersion, mossy fibre sprouting and calbindin expression in the granule cells. We quantified doublecortin, mini-chromosome maintenance protein 2 (MCM2) and reelin-expressing neuronal populations in the dentate gyrus as well as the distribution of cannabinoid type 1 receptor (CBR1).

RESULTS

The patterns of neuronal loss and gliosis were similar in both groups. HS-P patients demonstrated less mossy fibre sprouting and granule cell dispersion (p < 0.01) and more frequent reduction in calbindin expression in granule cells. There were no group differences in the densities of immature MCM2, doublecortin and reelin-positive cells. CBR1 labelling was significantly lower in Cornu ammonis area CA4 relative to other subfields (p < 0.01); although reduced staining in all hippocampal regions was noted in HS-P compared with HS-NP patients, the differences were not statistically significant.

CONCLUSIONS

The alterations in dentate gyrus pathology found in HS-P patients could indicate underlying differences in the cellular response to seizures. These mechanisms may predispose to the development of psychosis in epilepsy and warrant further investigation.

GWAS identifies an NAT2 acetylator status tag single nucleotide polymorphism to be a major locus for skin fluorescence

AIMS/HYPOTHESIS

Skin fluorescence (SF) is a non-invasive marker of AGEs and is associated with the long-term complications of diabetes. SF increases with age and is also greater among individuals with diabetes. A familial correlation of SF suggests that genetics may play a role. We therefore performed parallel genome-wide association studies of SF in two cohorts.

METHODS

Cohort 1 included 1,082 participants, 35-67 years of age with type 1 diabetes. Cohort 2 included 8,721 participants without diabetes, aged 18-90 years.

RESULTS

rs1495741 was significantly associated with SF in Cohort 1 (p < 6 × 10(-10)), which is known to tag the NAT2 acetylator phenotype. The fast acetylator genotype was associated with lower SF, explaining up to 15% of the variance. In Cohort 2, the top signal associated with SF (p = 8.3 × 10(-42)) was rs4921914, also in NAT2, 440 bases upstream of rs1495741 (linkage disequilibrium r (2) = 1.0 for rs4921914 with rs1495741). We replicated these results in two additional cohorts, one with and one without type 1 diabetes. Finally, to understand which compounds are contributing to the NAT2-SF signal, we examined 11 compounds assayed from skin biopsies (n = 198): the fast acetylator genotype was associated with lower levels of the AGEs hydroimidazolones of glyoxal (p = 0.017).

CONCLUSIONS/INTERPRETATION

We identified a robust association between NAT2 and SF in people with and without diabetes. Our findings provide proof of principle that genetic variation contributes to interindividual SF and that NAT2 acetylation status plays a major role.

The association of skin intrinsic fluorescence with type 1 diabetes complications in the DCCT/EDIC study

OBJECTIVE

To determine whether skin intrinsic fluorescence (SIF) is associated with long-term complications of type 1 diabetes (T1D) and, if so, whether it is independent of chronic glycemic exposure and previous intensive therapy.

RESEARCH DESIGN AND METHODS

We studied 1,185 (92%) of 1,289 active Diabetes Control and Complications Trial (DCCT)/Epidemiology of Diabetes Interventions and Complications (EDIC) participants from 2010 to 2011. SIF was determined using a fluorescence spectrometer and related cross-sectionally to recently determined measures of retinopathy (stereo fundus photography), cardiac autonomic neuropathy (CAN; R-R interval), confirmed clinical neuropathy, nephropathy (albumin excretion rate [AER]), and coronary artery calcification (CAC).

RESULTS

Overall, moderately strong associations were seen with all complications, before adjustment for mean HbA1c over time, which rendered these associations nonsignificant with the exception of sustained AER>30 mg/24 h and CAC, which were largely unaffected by adjustment. However, when examined within the former DCCT treatment group, associations were generally weaker in the intensive group and nonsignificant after adjustment, while in the conventional group, associations remained significant for CAN, sustained AER>30 mg/24 h, and CAC even after mean HbA1c adjustment.

CONCLUSIONS

SIF is associated with T1D complications in DCCT\EDIC. Much of this association appears to be related to historical glycemic exposure, particularly in the previously intensively treated participants, in whom adjustment for HbA1c eliminates statistical significance.

Clinical and technical factors associated with skin intrinsic fluorescence in subjects with type 1 diabetes from the Diabetes Control and Complications Trial/Epidemiology of Diabetes Interventions and Complications Study

BACKGROUND

The Diabetes Control and Complications Trial (DCCT)/Epidemiology of Diabetes Interventions and Complications(EDIC) studies have established multiyear mean hemoglobin A1c (HbA1c) as predictive of microvascular complications in persons with type 1 diabetes. However, multiyear mean HbA1c is not always available in the clinical setting. Skin advanced glycation end products (AGEs) are thought to partially reflect effects of hyperglycemia over time, and measurement of skin AGEs might be a surrogate for multiyear mean HbA1c. As certain AGEs fluoresce and skin fluorescence has been demonstrated to correlate with the concentration of skin AGEs, noninvasive measurement by skin intrinsic fluorescence(SIF) facilitates the exploration of the association of mean HbA1c and other clinical/technical factors with SIF using the detailed phenotypic database available in DCCT/EDIC.

SUBJECTS AND METHODS

Of the subjects, 1,185 (53% male) had measurements of SIF during years 16/17 of EDIC with mean age and diabetes duration of 51.5 and 29.8 years, respectively. SIF measurements were obtained on the underside of the forearm near the elbow using a skin fluorescence spectrometer. Demographic data and health history were self-reported, and an annual standardized examination measured clinical status. Linear regression models were constructed to identify significant clinical and technical factors associated with SIF, and the final models only used factors that were significant.

RESULTS

SIF ranged from 8.7 to 54.0 arbitrary units and was log-normally distributed. Log(SIF) correlated more with mean HbA1c as the time period increased. In multivariate analyses log(SIF) was significantly associated with mean HbA1c, age,estimated glomerular filtration rate < 60mL/min/m2, smoking status, skin tone, and clinic latitude <37 N.

CONCLUSIONS

SIF reflects age, mean HbA1c over time, smoking, and renal damage, which are known risk factors for diabetes complications.

Screening for HbA1c-defined prediabetes and diabetes in an at-risk greek population: performance comparison of random capillary glucose, the ADA diabetes risk test and skin fluorescence spectroscopy

BACKGROUND

We examined the accuracy of random capillary glucose (RCG) and two noninvasive screening methods, the ADA diabetes risk test (DRT) and skin fluorescence spectroscopy (SFS) as measured by Scout DS for detecting HbA1c-defined dysglycemia or type 2 diabetes in an at-risk cohort.

METHODS

Subjects were recruited at two clinical sites for a single non-fasting visit. Each subject had measurements of height, weight and waist circumference. A diabetes score was calculated from skin fluorescence measured on the left forearm. A finger prick was done to measure RCG and HbA1c (A1C). Health questionnaires were completed for the DRT. Increasing dysglycemia was defined as A1C ≥ 5.7% (39 mmol/mol) or ≥ 6.0% (42 mmol/mol). Type 2 diabetes was defined as A1C ≥ 6.5% (47.5 mmol/mol).

RESULTS

398 of 409 subjects had complete data for analysis with means for age, body mass index, and waist of 52 years, 27 kg/m(2) and 90 cm. 51% were male. Prevalence of A1C ≥ 5.7%, ≥ 6.0% and ≥ 6.5% were 54%, 34% and 12%, respectively. Areas under the curve (AUC) for detection of increasing levels dysglycemia or diabetes for RCG were 63%, 66% and 72%, for the ADA DRT the AUCs were 75%, 76% and 81% and for SFS the AUCs were 82%, 84% and 90%, respectively. For each level of dysglycemia or diabetes, the SFS AUC was significantly higher than RCG or the ADA DRT.

CONCLUSIONS

The noninvasive skin fluorescence spectroscopy measurement outperformed both RCG and the ADA DRT for detection of A1C-defined dysglycemia or diabetes in an at-risk cohort.

Skin intrinsic fluorescence is associated with hemoglobin A(1c )and hemoglobin glycation index but not mean blood glucose in children with type 1 diabetes

OBJECTIVE

To evaluate the relationship between skin advanced glycation end products (sAGEs) with mean blood glucose (MBG), hemoglobin A(1c) (HbA(1c)), and MBG-independent, between-patient differences in HbA(1c) among children with type 1 diabetes.

RESEARCH DESIGN AND METHODS

Children aged 5 to 20 years with type 1 diabetes of at least 1 year duration participated. At a clinic visit, sAGE was estimated noninvasively by measurement of skin intrinsic fluorescence (SIF). SIF data were adjusted to correct for variation in skin pigmentation. MBG-independent, between-patient differences in HbA(1c) were examined by statistically controlling HbA(1c) for MBG or alternatively by use of a hemoglobin glycation index (HGI). Results were similar whether HbA(1c), MBG, and HGI were analyzed as single values from the time of the SIF examination visit or as the mean values from all available visits of the patient.

RESULTS

HbA(1c) was correlated with MBG (r = 0.5; P < 0.001; n = 110). HbA(1c) and HGI, but not MBG, were statistically associated with SIF after adjustment for age, duration of diabetes, race, sex, and BMI z-score. SIF increased with age and duration of diabetes and was higher in girls than boys.

CONCLUSIONS

sAGE levels estimated by SIF increase with age, duration of diabetes, and female sex. sAGE is correlated with MBG-independent biological variation in HbA(1c), but not with MBG itself. These results suggest that factors besides MBG that influence HbA(1c) levels also contribute to accumulation of sAGE.

Skin fluorescence correlates strongly with coronary artery calcification severity in type 1 diabetes

BACKGROUND

Coronary artery calcification (CAC) is more severe and occurs at an earlier age in type 1 diabetes. Risk factors for this subclinical marker of atherosclerotic burden, like coronary artery disease (CAD) itself, are not fully identified. One postulated mechanism for the increased CAC observed in type 1 diabetes is the accumulation of advanced glycation end products (AGEs). As certain collagen AGEs fluoresce, skin intrinsic fluorescence (SIF) can act as a novel marker of levels of collagen AGEs. We thus sought to determine the relationship between skin intrinsic fluorescence and CAC in type 1 diabetes.

METHODS

One hundred five participants in the Pittsburgh Epidemiology of Diabetes Complications study of childhood-onset (age <17 years) type 1 diabetes who had previously undergone electron beam tomography scanning for CAC (80 of whom had follow-up data) had SIF measurements taken using the SCOUT DM (VeraLight, Inc., Albuquerque, NM). Mean age and diabetes' duration were 49 and 40 years, respectively, at the time of SIF measurement.

RESULTS

Seventy-one percent of the study participants had some measurable CAC that was univariately (but not after age adjustment) cross-sectionally associated with SIF (odds ratio = 2.51, 1.37-4.59). However, for CAC severity using natural logarithmically transformed scores, SIF was both univariately (P < 0.0001) and multivariably (P = 0.03) associated with CAC. This relationship was independent of age, a history of CAD, renal function, or renal damage. Receiver operator characteristic analyses revealed that the discriminative ability of SIF to detect CAC went from an area under the curve of 71% for the presence of any CAC to 85% for those with a CAC score >400.

CONCLUSIONS

The relationship between SIF and CAC appears stronger with more severe calcification. Given the strong relationship of CAC with CAD this finding has important implications and suggests that SIF maybe a useful marker of CAC/CAD risk and potentially a therapeutic target.

Vector prime protein boost vaccination in the setting of myeloablative-induced lymphopenia suppresses growth of leukemia and solid tumors

We have developed a vaccine, which is designed to induce tumor-associated antigen (TAA)-specific T cells and antibodies in the setting of profound lymphopenia induced by myeloablative therapy and T-cell-depleted bone marrow transplantation. Test mice were injected subcutaneously (sc) with the 32DP210Bcr-Abl cell line, which is positive for the p210Bcr-Abl protein (Group 1). In Group 2, 7 days after injection of the 32DP210Bcr-Abl positive cell line, the mice received 900 cGy total body irradiation (TBI) followed in 1 h by the intravenous infusion of 10 million T-cell-depleted syngeneic bone marrow cells (TCDBMT) (Group 2). The leukemia-bearing group received an intravenous injection of 10 million spleen cells (donor lymphocyte infusions) from unvaccinated (Group 3) and TAA/ecdCD40L-vaccinated (Group 4) syngeneic mice 3 days after completion of the TBI and TCDBMT. Groups 3 and 4 mice received three additional sc vaccinations at 7-day intervals with the TAA/ecdCD40L vaccine, in which the TAA was taken from the junctional peptide of the P210bcr-Abl protein. The survival of Groups 3 and 4 mice was significantly longer than that in Groups 1 and 2 mice. Vaccinated mice from Group 4, which developed complete responses, survived up to 350 days post-injection of the leukemia cells without any evidence of leukemia regrowth.

Targeting of chemotherapy to Tie-2-receptor positive angiogenic endothelial cells of tumor vasculature

Abstract #902

Background: There are at least three types of cells in tumor tissue which express the Tie2 receptor (Tie2R): dividing vascular endothelial cells (TVECs), Tie2R-expressing monocytes (TEMs) and Tie2R-expressing mesenchymal progenitor cells (TMPCs).&#x2028; &#x2028; We tested if the targeting of chemotherapy to these classes of Tie2R positive cells could suppress tumor cell growth.&#x2028; Material and Methods: We constructed replication incompetent adenoviral vectors carrying the cytosine deaminase (CD) suicide gene driven by the mouse Tie2R transcriptional promoter and enhancer sequences. In these viruses, we inserted an RGD-4C peptide into the HI loop of the fiber knob domain of the vector to increase its transduction efficiency in TVECs. At the same time, we added two mutations (S408E and P409A) in the AB loop of the fiber, which ablated the CAR-binding ability of the vector. The resulting vector was named AdTie2RCD(MRGD).&#x2028; Results: In vitro viral infection assays involving the human umbilical vein endothelial cells (HUVECs) showed that the RGD-modified vectors have a higher transduction efficiency as compared with their adenoviral vector counterparts which have a wild type fiber protein. Mice carrying the rat Her-2-Neu positive N202 mouse breast cancer cells and the mouse B16 melanoma cells were treated with intravenous injections of Hetastarch and the AdTie2RCD(MRGD) vector followed by intraperitoneal injections of 5-Fluorocytosine (5-FC). The Hetastarch was given before the intraveinous infusion of the adenoviral vector in order to reduce the uptake of the adenoviral vector by the reticuloendothelial cell system. The Tie2R targeted chemotherapy sensitization vectors induced greater degrees of suppression of tumor cell growth than did the control group, achieved the similar treatment effect to its CMV promoter counterpart, but with less side effect.&#x2028; &#x2028; Histological analysis showed that these vectors specifically targeted the TVECs, TEMs and TMPCs through which they may have exerted cytotoxic effects in the presence of 5-FC on the tumor cells.&#x2028; Discussion: Our results showed that N202 breast cancer cell line is more responsive to the Tie2R-targeting therapy compared to B16 mouse melanoma cell line and the Tie2R-directed anti-angiogenic therapy deserves further study, in combination with other types of therapy to pave the way for future clinic trails.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 902.

Inherited predisposition to colorectal adenomas caused by multiple rare alleles of MUTYH but not OGG1, NUDT1, NTH1 or NEIL 1, 2 or 3

BACKGROUND

MUTYH-associated polyposis (MAP) is a recessive trait characterised by multiple colorectal adenomas and a high risk of colorectal cancer. MUTYH functions in the DNA base excision repair pathway and has a key role in the repair of oxidative DNA damage.

OBJECTIVES

To assess the contribution of inherited variants in genes involved in base excision repair and oxidative DNA damage including MUTYH, OGG1, NEIL1, NEIL2, NEIL3, NUDT1 and NTH1 to the multiple colorectal adenoma phenotype.

METHODS

Inherited variants of MUTYH, OGG1, NEIL1, NEIL2, NEIL3, NUDT1 and NTH1 were sought in 167 unrelated patients with multiple colorectal adenomas whose family histories were consistent with recessive inheritance. These variants were also characterised in approximately 300 population controls.

RESULTS

Thirty-three patients (20%) and no controls were MUTYH homozygotes or compound heterozygotes (ie, carried two mutations) and therefore had MAP. Eight different pathogenic MUTYH mutations were identified, of which four were novel. MAP cases had significantly more adenomas than non-MAP cases (p = 0.0009; exact test for trends in proportions) and presented earlier (p = 0.013; analysis of variance). Twenty-four protein-altering variants were identified upon screening of OGG1, NEIL1, NEIL2, NEIL3, NUDT1 and NTH1. However, all combinations of two (or more) variants that were identified at an individual locus in patients were also seen in controls, and no variants were significantly over-represented (or under-represented) in cases.

CONCLUSION

Multiple rare alleles of MUTYH are associated with autosomal recessive MAP, while OGG1, NEIL1, NEIL2, NEIL3, NUDT1 and NTH1 do not contribute significantly to autosomal recessive polyposis.

Donor lymphocyte infusions from Ad-sig-TAA/ecdCD40L vector prime-TAA/ecdCD40L protein boost (VPP) vaccinated allodonors decrease tumor cell growth post allograft

3071

Background: Individuals of advanced chronological age exhibit an impaired immune response to vaccines. This may be due to a reduction in the ratio of antigen naïve/memory CD4 and CD8 T cells and acquisition of functional defects in activated “helper” CD4 T cells (eg diminished CD40 ligand (CD40L) expression) during the aging process. Methods: In order to circumvent this defective response to vaccines in individuals in the fifth and sixth decades of life, our laboratory has developed an adenoviral vector (Ad-sig- TAA/ecdCD40L) vaccine which is designed for the in vivo target associated antigen (TAA) loading and activation of dendritic cells (DCs), and to overcome the absence of CD40L expression in activated CD4 helper T cells in older individuals. Results: The subcutaneous (sc) injection of this vector leads to the release of a fusion protein composed of a TAA linked to the extracellular domain (ecd) of the CD40 ligand (CD40L), which binds to the CD40 receptor on DCs, activates the DCs, and leads to the presentation of TAA fragments on Class I MHC. Two sc injections of the TAA/ecdCD40L protein as a booster following the sc administration of the Ad-sig-TAA/ecdCD40L vector (VPP) expands the magnitude of the cellular and humoral immune response induced by the vector in 18 month old aged mice as well as in younger mice. This vaccine decreased levels of negative regulatory CD4 FOXP3 T cells in tumor nodules. We administered TBI and an allogeneic stem cell transplant 7 days post sc injection of the E7 positive TC-1 cells. DLI from an Ad-sig-E7/ecdCD40L vector prime-E7/ecdCD40L protein boost vaccinated donor were injected iv 3 days post transplant, and a single E7/ecdCD40L protein boost sc vaccination one week thereafter. We found that the growth rate of the E7 positive TC-1 tumor cells post allograft was less in the vaccinated than in the control (injection of tumor cells followed in 7 days by TBI), or the animals in which the allograft recipient was vaccinated without DLI. Conclusions: Thus, the use of DLI from VPP vaccinated allodonors decreased tumor cell growth post allograft.

No significant financial relationships to disclose.

Mapping of angiogenic markers for targeting of vectors to tumor vascular endothelial cells

The vasculature of mouse breast tumor spheroids grown on mammary fat pad tissue in an intravital microscopy (IVM) viewing chamber was shown to derive from infiltrating angiogenic mammary vessels. The receptors tissue factor (TF), alpha V beta 3 integrin and Tie-2 were expressed on the vascular endothelium in the periphery but not in the center of the tumor spheroids nor in the mammary tissue nor in smooth muscle tissue, whereas Tie-1 and PCAM-1 were expressed extensively in the entire tumor and in the vascular endothelium of the entire tumor nodule and in normal mammary tissue. TF is a specific target for adenoviral vector-mediated cancer immunotherapy. Subcutaneous injection of the AdfVII/IgG(1)Fc vector leads to the release into the system circulation of a fVII/IgG(1)Fc immunoconjugate molecule that binds specifically and tightly to TF on vascular endothelial cells and tumor cells, activating a cytolytic immune response against the targeted cells. We show that a single administration of the AdfVII/IgG(1)Fc vector destroys the peripheral but not the central vasculature of a tumor spheroid, causing partial tumor regression; additional administrations prevent regeneration of the peripheral vasculature and regrowth of the tumor. These findings indicate that a critical parameter for optimizing tumor damage is the schedule for successive administrations of the AdfVII/IgG(1)Fc, which should coincide with the regeneration of the peripheral vasculature and continue until the tumor is destroyed.

Vaccine for prevention of breast cancer

2580

Background: Women with high risk breast cancer still succumb to their disease despite existing programs of adjuvant therapy. Thus, new approaches for adjuvant therapy are needed. Her-2-Neu overexpression on a breast cancer cells correlates with recurrence, metastasis and resistance to chemotherapy and radiation therapy. The immune response is tolerant of tumor associated antigens (TAA) like Her-2-Neu since they have been present on epithelial cells since birth. The immune response to vaccines in women with breast cancer is limited by the diminished number of CD4 and CD8 T cells and qualitative defects of CD4 cells in individuals above the age of 50. Methods: The following strains of mice were vaccinated: 6–8 week old hMUC-1.Tg mice, and rH2N.Tg mice, as well as 18 month and 2 month old C57BL/6J mice, by injecting subcutaneously the Ad-sig-TAA/ecdCD40L vector prime followed by sc injections of the TAA/ecdCD40L protein boost. Results: Vaccination of 18 month old mice with the Ad-sig-TAA/ecdCD40L vector prime protein boost produce regressions of TAA positive sc tumor and a 5 fold increase in antigen specific spleen cells, a 10X increase in subcutaneous tumor nodules of antigen specific effector CD8 T cells by tetramers, and a 2X decrease of CD4+CD25+FOXP3+ cells. Vaccination of rH2N.Tg mice starting at 6 weeks with the Ad-sig-rH2N/ecdCD40L vector prime/protein boost prevented the development of breast cancer in 50% of the mice. The Ad-sig-hMUC-1/ecdCD40L vector prime/ hMUC-1/ecdCD40L protein boost induced hMUC-1 specific antibodies in hMUC-1.Tg mice which bound to human breast cancer specimens. The rH2N/ecdCD40L vector prime/protein boost vaccine suppressed growth of rH2N positive tumor cells and this effect was potentiated by concomitant administration of chemotherapy. Conclusions: These results suggest that the Ad-sig-TAA/ecdCD40L platform can be used to suppress the growth of existing breast cancer even in old mice and prevent the development of breast cancer. We are preparing a phase I clinical trial of this approach in the setting of breast cancer patients who have failed first line adjuvant therapy. In this trial, the vaccine will be added to established salvage therapy and both in vivo evaluations of tumor response, in vitro assays of immune response and toxicity will be measured.

No significant financial relationships to disclose.

Tumor-specific therapeutic effect induced by an oncolytic adenoviral vector containing heat shock protein 70 and prodrug activation genes

We constructed a melanoma-specific oncolytic adenoviral vector Ad.MCDIRESE1.71Hsp3, in which the cytosine deaminase and adenoviral E1A genes linked by the IRES sequence were under the control of a mouse tyrosinase enhancer/promoter transcriptional element in the E1 region of the vector. We also inserted the human heat shock protein 70 (Hsp70) gene driven by the cytomegalovirus promoter into the E3 region of this vector. The RGD-4C peptide was inserted into the HI loop of the fiber knob domain of the Ad.MCDIRESE1.71Hsp3 vector to increase the transduction efficiency of this vector to tumor cells. The Ad.MCDIRESE1.71Hsp3 vector replicates specifically in melanoma cells, and it has a melanoma-specific cytotoxic effect in the presence of 5-fluorocytosine in vitro and in vivo. Moreover, the in vivo killing of tumor cells associated with the overexpression of Hsp70 generated by the intratumoral injection of the Ad.MCDIRESE1.71Hsp3 vector into established subcutaneous tumors can lead to the suppression of tumor growth and potent melanoma-specific systemic immune responses.

Engineering conditionally replication-competent adenoviral vectors carrying the cytosine deaminase gene increases the infectivity and therapeutic effect for breast cancer gene therapy

We constructed a conditionally replication-competent adenoviral vector Ad.Lp-CD-IRES-E1A(control) in which the expression of both the prodrug-activating cytosine deaminase gene and the viral replication E1A gene were driven by the L-plastin tumor-specific promoter. In order to overcome the low infectivity of the adenoviral vectors for breast cancer cells, and to increase the safety and efficacy for cancer gene therapy, this vector was further modified on a transductional level by simultaneously ablating the native tropism of the vector to the primary CAR receptor and inserting a RGD-4C peptide into the HI loop of the fiber, which allows the vector to use the alphavbeta3 and alphavbeta5 receptors as alternative receptors. The resulting vector was named Ad.Lp-CD-IRES-E1A(MRGD). The transduction efficiency of the vector for breast cancer cell lines which have low expression level of CAR was increased both in vitro and in vivo. The Ad.Lp-CD-IRES-E1A(MRGD) vector produces a higher vector particle yield and a greater cytotoxic effect in tumor cells which have a low expression level of CAR, than did the Ad.Lp-CD-IRES-E1A(control) vector. Intratumoral injection of the Ad.Lp-CD-IRES-E1A(MRGD) vector following the intraperitoneal injection of 5FC into xenotransplanted human breast cancer cell lines which have low expression level of CAR led to greater degree of tumor regression in vivo than did the intratumoral injection of control adenoviral vectors not so modified.

Management systems response to improving immunization coverage in developing countries: a case study from Cambodia

INTRODUCTION

In contrast to the initial success following the establishment of the National Immunization Program (NIP) in Cambodia in 1986, infant vaccination coverage rates against the six expanded program immunization diseases have not improved since 1995. In response, the NIP of the Ministry of Health has undertaken a series of institutional initiatives to address the problem of static or declining rates of coverage. The aim of this paper is to describe and assess management strategies undertaken by the NIP in Cambodia in support of improved immunization coverage.

METHODS

Sources of information used in preparing this report include international literature, national coverage and surveillance data, government policy documentation, information generated by national strategic planning and health centre microplanning processes, a functional analysis of human resources, and data quality audits.

RESULTS

The NIP has implemented planning, organizational development and human resource development responses to the problem of low coverage. These have included: integration of the nip strategic and operational plans into the health sector plan; strengthening of needs-based microplanning; establishment of a national monitoring and management support strategy; and the introduction of performance-based agreements between levels of government for improved immunization coverage.

CONCLUSIONS

Our analysis of these findings, in particular of the international literature, suggests that NIP's responses have been appropriate, and that the development of NIP management systems and capacity will increase the likelihood for sustained immunization coverage gains within a reform environment of health system decentralization. In 2003, there are early signs that the reform processes undertaken by the NIP have resulted in improved immunization coverage in targeted areas, and this should place the national program in a stronger position to lift immunization coverage in 2004.

A technique for the determination of 18O/16O and 17O/16O isotopic ratios in water from small liquid and solid samples

We have developed a new technique in which a solid reagent, cobalt(III) fluoride, is used to prepare oxygen gas for isotope ratio measurement from water derived either from direct injection or from the pyrolysis of solid samples. The technique uses continuous flow, isotope ratio monitoring, gas chromatography/mass spectrometry (irmGC/MS) to measure the delta18O and delta17O of the oxygen gas. Water from appropriate samples is evolved by a procedure of stepped pyrolysis (0-1000 degrees C, typically in 50 degrees C increments) under a flowing stream of helium carrier gas. The method has considerable advantages over others used for water analysis in that it is quick; requires only small samples, typically 1-50 mg of whole rock samples (corresponding to approximately 0.2 micromol of H2O); and the reagent is easy and safe to handle. Reproducibility in isotope ratio measurement obtained from pyrolysis of samples of a terrestrial solid standard are delta18O +/- 0.54, delta17O +/- 0.33, and delta17O +/- 0.10/1000, 1sigma in all cases. The technique was developed primarily for the analysis of meteorites, and the efficiency of the method is illustrated herein by results from water standards, solid reference materials, and a sample of the Murchison CM2 meteorite.

A multiinstitutional, concurrent chemoradiation trial of strontium-89, estramustine, and vinblastine for hormone refractory prostate carcinoma involving bone

BACKGROUND

Estramustine phosphate (EMP) and vinblastine have radiosensitizing properties and significant activity against hormone refractory prostate carcinoma. Strontium-89 is a palliative agent that acts as a selective radiation source for bone metastasis. The combination of EMP, vinblastine, and strontium-89 was developed to exploit the potential for radiosynergy. PATIENTS AND METHODS Forty-four patients at the Brown Oncology Group affiliated hospitals were treated with oral EMP 600 mg/m2 daily on Weeks 1-4 and 7-10, vinblastine 4 mg/m2 intravenously once each week on Weeks 1-4 and 7-10, and strontium-89 2.2 MBq/kg on Day 1. Courses were repeated every 12 weeks. Response assessment was based on a change in the serum prostate specific antigen (PSA) levels, correlated with change in measurable disease and bone scan appearance.

RESULTS

A greater than or equal to 50% decline in PSA for at least 6 weeks was observed in 21 patients (48%, 95% confidence interval, 33-62%). Median duration of response was 23 weeks (range, 6-70.8 weeks). The median survival was 13 months with 1- and 2-year survival rates of 55% and 25%, respectively. After completion of protocol therapy, a retrospective review showed that only nine patients received subsequent palliative external beam radiation after progression.

CONCLUSIONS

The addition of strontium-89 to the regimen of EMP and vinblastine can be delivered safely and in repeated doses, provides effective palliation, and may decrease the need for future radiation therapy. A randomized trial is necessary to quantify these effects.

Antibody engineering

Antibodies are unique in their high affinity and specificity for a binding partner, a quality that has made them one of the most useful molecules for biotechnology and biomedical applications. The field of antibody engineering has changed rapidly in the past 10 years, fueled by novel technologies for the in vitro isolation of antibodies from combinatorial libraries and their functional expression in bacteria. This review presents an overview of the methods available for the de novo generation of human antibodies, for engineering antibodies with increased antigen affinity, and for the production of antibody fragments. Select applications of recombinant antibodies are also presented.

Pathological mutations in TSC1 and TSC2 disrupt the interaction between hamartin and tuberin

Critical functions of hamartin and tuberin, encoded by the TSC1 and TSC2 genes, are likely to be closely linked. The proteins interact directly with one another and mutations affecting either gene result in the tuberous sclerosis phenotype. However, the regions of hamartin and tuberin that interact have not been well defined, and the relationship between their interaction and the pathogenesis of tuberous sclerosis has not been explored. To address these issues a series of hamartin and tuberin constructs were used to assay for interaction in the yeast two-hybrid system. Hamartin (amino acids 302-430) and tuberin (amino acids 1-418) interacted strongly with one another. A region of tuberin encoding a putative coiled-coil (amino acids 346-371) was necessary but not sufficient to mediate the interaction with hamartin, as more N-terminal residues were also required. A region of hamartin (amino acids 719-998) predicted to encode coiled-coils was capable of oligermerization but was not important for the interaction with tuberin. Subtle, non-truncating mutations identified in patients with tuberous sclerosis and located within the putative binding regions of hamartin (N198_F199delinsI;593-595delACT) or tuberin (G294E and I365del), abolished or dramatically reduced interaction of the proteins as assessed by yeast two-hybrid assays and by co-immunoprecipitation of the full-length proteins from Cos7 cells. In contrast, three non-pathogenic missense polymorphisms of tuberin (R261W, M286V, R367Q) in the same region as the disease-causing TSC2 mutations did not. These results indicate a requirement for interaction in critical growth suppressing functions of hamartin and tuberin.

LD-PCR coupled to long-read direct sequencing: an approach for mutation detection in genes with compact genomic structures

A number of techniques have been developed as primary screens to scan for DNA sequence variants, including denaturing gradient gel electrophoresis, denaturing high-performance liquid chromatography, single-strand conformation polymorphism and heteroduplex analysis. Variant alleles detected by these assays are subsequently characterised by DNA sequencing. Sequencing itself is rarely used as a primary screen because of labour intensity, cost, and, upon automation, occasional inaccuracy in identifying heterozygous sites. We have previously developed an approach based on coupling long-distance PCR (LD-PCR) to long-read direct sequencing to allow the detection of mutations in the approximately 1.1 kb exon 3 of MECP2. Our use of dye-labelled primers generated high-quality bi-directional sequence runs > 650 bp and allowed easy discrimination of heterozygous bases. We now describe the application of this approach to the detection of mutations in a considerably larger 6.35 kb LD-PCR fragment spanning 10 exons (exons 32-41) of the structurally complex, but genomically compact, TSC2 gene. In a blind analysis, 15/15 previously characterised mutations were successfully identified using seven overlapping bi-directional sequencing reactions. Our approach of long-read sequencing of long-distance PCR products may allow rapid sequencing of multiple exons of compact genes and may be appropriate as a highly sensitive primary screen for mutations.