Effects of subchronic exposure of silver nanoparticles on intestinal microbiota and gut-associated immune responses in the ileum of Sprague-Dawley rats.

Silver nanoparticles (AgNP) are widely used for their antibacterial properties. Incorporation of AgNP into food-related products and health supplements represents a potential route for oral exposure to AgNP; however, the effects of such exposure on the gastrointestinal system are mostly unknown. This study evaluated changes in the populations of intestinal-microbiota and intestinal-mucosal gene expression in Sprague-Dawley rats (both male and female) that were gavaged orally with discrete sizes of AgNP (10, 75 and 110 nm) and silver acetate. Doses of AgNP (9, 18 and 36 mg/kg body weight/day) and silver acetate (100, 200 and 400 mg/kg body weight/day) were divided and administered to rats twice daily (∼10 h apart) for 13 weeks. The results indicate that AgNP prompted size- and dose-dependent changes to ileal-mucosal microbial populations, as well as, intestinal gene expression and induced an apparent shift in the gut microbiota toward greater proportions of Gram-negative bacteria. DNA-based analyses revealed that exposure to 10 nm AgNP and low-dose silver acetate caused a decrease in populations of Firmicutes phyla, along with a decrease in the Lactobacillus genus. Analysis of host gene expression demonstrated that smaller sizes and lower doses of AgNP exposure prompted the decreased expression of important immunomodulatory genes, including MUC3, TLR2, TLR4, GPR43 and FOXP3. Gender-specific effects to AgNP exposure were more prominent for the gut-associated immune responses. These results indicate that the oral exposure to AgNP alter mucosa-associated microbiota and modulate the gut-associated immune response and the overall homeostasis of the intestinal tract.

High-dose-rate brachytherapy alone for localized prostate cancer in patients at moderate or high risk of biochemical recurrence.

PURPOSE: To evaluate genitourinary (GU) and gastrointestinal (GI) morbidity and biochemical control of disease in patients with localized prostate adenocarcinoma treated with escalating doses per fraction of high-dose rate brachytherapy alone. METHODS AND MATERIALS: A total of 197 patients were treated with 34 Gy in four fractions, 36 Gy in four fractions, 31.5 Gy in three fractions, or 26 Gy in two fractions. Median follow-up times were 60, 54, 36, and 6 months, respectively. RESULTS: Incidence of early Grade ≥ 3 GU morbidity was 3% to 7%, and Grade 4 was 0% to 4%. During the first 12 weeks, the highest mean International Prostate Symptom Score (IPSS) value was 14, and between 6 months and 5 years it was 8. Grade 3 or 4 early GI morbidity was not observed. The 3-year actuarial rate of Grade 3 GU was 3% to 16%, and was 3% to 7% for strictures requiring surgery (4-year rate). An incidence of 1% Grade 3 GI events was seen at 3 years. Late Grade 4 GU or GI events were not observed. At 3 years, 99% of patients with intermediate-risk and 91% with high-risk disease were free of biochemical relapse (log-rank p = 0.02). CONCLUSIONS: There was no significant difference in urinary and rectal morbidity between schedules. Biochemical control of disease in patients with intermediate and high risk of relapse was good.

Basic apoptotic mechanisms of lead toxicity in human leukemia (HL-60) cells.

Lead exposure represents a medical and public health emergency, especially in children consuming high amounts of lead-contaminated flake paints. It may also cause hematological effects to people of all ages. Recent studies in our laboratory have indicated that apoptosis may be associated with the lead-induced oxidative stress and DNA damage. However, the mechanisms underlying its effect on lymphocytes are still largely unknown. Therefore, the aim of the present study was to investigate the apoptotic mechanisms of lead nitrate [Pb(NO(3))(2)] using HL-60 cells as a test model. HL-60 cells were treated with different concentrations of Pb(NO(3))(2) for 24 h prior to cell viability assay and flow cytometry assessment. The results obtained from the trypan blue exclusion test indicated that at very low concentration, Pb(NO(3))(2) has no effect on the viability of HL-60 cells. A significant (p < 0.05) decrease in cell viability was observed when exposed to high level of Pb(NO(3))(2). Data generated from the flow cytometric assessment indicated that Pb(NO(3))(2) exposure significantly (p < 0.05) increased the proportion of annexin V positive cells (apoptotic cells) compared to the control. Pb(NO(3))(2) induced apoptosis of HL-60 cells was associated with the activation of caspase-3. In summary, these studies demonstrated that Pb(NO(3))(2) represents an apoptosis-inducing agent in HL-60 promyelocytic leukemia cells and its apoptotic mechanism functions, at least in part via, induction of phosphatidylserine externalization and caspase-3 activation.

Quantitative helical dynamic contrast enhanced computed tomography assessment of the spatial variation in whole tumour blood volume with radiotherapy in lung cancer.

We aim to assess the spatial distribution of blood volume (BV) in whole lung tumours in patients undergoing radiotherapy using helical dynamic contrast enhanced computed tomography (DCE-CT), and to determine whether conventional single level, or whole tumour measurements is more representative of the vascular effects of radiotherapy. Following ethical approval and informed consent, 15 patients with histologically proven non-small cell lung cancer underwent paired helical DCE-CT studies at baseline to assess repeatability, and after two fractions of radiotherapy (9 Gy total dose). Tumour BV was calculated for individual contiguous 10mm axial slices, and for the entire tumour volume on a pixel-per-pixel basis. Baseline tumour BV was heterogeneous varying by 15.33%+/-17.11 between adjacent 10mm axial slices. Within subject coefficient of variation was 36.72% with conventional single tumour level evaluation, and 13.62% with whole tumour measurements. Following radiotherapy, one patient had an increase in BV greater than baseline variation (derived from the 95% limits of change) using single level evaluation; in contrast, seven patients had an increase in BV when the whole tumour was assessed. As a group, following radiotherapy, mean BV increased by 17.27% (paired t-test, p=0.20) with single level evaluation and 19.26% (p=0.049) with whole tumour assessment. Tumour BV measured using DCE-CT is spatially heterogeneous. Given the slice-by-slice variation in blood volume, our results demonstrate that whole tumour DCE-CT measurements are more repeatable, and may be a better predictor of vascular changes following therapy, compared to conventional single tumour level evaluations.

Effect of nitric-oxide synthesis on tumour blood volume and vascular activity: a phase I study.

BACKGROUND: Nitric oxide has been implicated in tumour angiogenesis and in the maintaining of vasodilator tone of tumour blood vessels. The tumour vascular effects of inhibition of nitric-oxide synthesis have not been investigated in patients with cancer. METHODS: Seven women and 11 men (12 with non-small-cell lung cancer, five prostate cancer, and one cervical cancer) were recruited onto a phase I dose-escalation study and received a single dose of the nitric oxide synthase inhibitor, N-nitro-L-arginine (L-NNA). Dose escalation was done by a modified Fibonacci scale with three patients at each dose level, starting with 0.1 mg/kg. Changes in dynamic contrast-enhanced CT measures of tumour relative blood volume and transfer constant (K) were measured at 1 h and 24 h after L-NNA administration. FINDINGS: In the 18 patients, toxic effects were self-limiting cardiovascular changes: three patients had Common Toxicity Criteria version 2.0 grade 1 hypertension; two had grade 1 sinus bradycardia; and one had grade 1 palpitation. L-NNA area under the curve (AUC) increased linearly with dose from 163 micromol min(-1) L(-1) at 0.1 mg/kg L-NNA to 2150 micromol min(-1) L(-1) at 0.9 mg/kg L-NNA. In eight patients that underwent dynamic CT scanning, tumour blood volume decreased 1 h after L-NNA treatment (mean 42.9% [range 12.0-62.1]; paired t test p=0.0070), which was sustained for up to 24 h (mean 33.9% [range 6.5-64.9]; p=0.035). This decrease in blood volume was associated with an increase in the number of non-perfused pixels from 7.3% (SD 5.5) at baseline to 25.1% (15.3; p=0.0089) at 1 h, and 18.2% (12.9; p=0.050) at 24 h. There was a significant correlation between L-NNA plasma AUC and the reduction in tumour blood volume at 24 h after L-NNA (r=0.83; p=0.010). INTERPRETATION: We have shown in vivo in patients with cancer that nitric oxide has a role in maintaining tumour blood supply, and we provide early clinical evidence that inhibition of nitric-oxide synthesis has tumour antivascular activity.

Acute tumor vascular effects following fractionated radiotherapy in human lung cancer: In vivo whole tumor assessment using volumetric perfusion computed tomography.

PURPOSE: To quantitatively assess the in vivo acute vascular effects of fractionated radiotherapy for human non-small-cell lung cancer using volumetric perfusion computed tomography (CT). METHODS AND MATERIALS: Sixteen patients with advanced non-small-cell lung cancer, undergoing palliative radiotherapy delivering 27 Gy in 6 fractions over 3 weeks, were scanned before treatment, and after the second (9 Gy), fourth (18 Gy), and sixth (27 Gy) radiation fraction. Using 16-detector CT, multiple sequential volumetric acquisitions were acquired after intravenous contrast agent injection. Measurements of vascular blood volume and permeability for the whole tumor volume were obtained. Vascular changes at the tumor periphery and center were also measured. RESULTS: At baseline, lung tumor vascularity was spatially heterogeneous with the tumor rim showing a higher vascular blood volume and permeability than the center. After the second, fourth, and sixth fractions of radiotherapy, vascular blood volume increased by 31.6% (paired t test, p = 0.10), 49.3% (p = 0.034), and 44.6% (p = 0.0012) respectively at the tumor rim, and 16.4% (p = 0.29), 19.9% (p = 0.029), and 4.0% (p = 0.0050) respectively at the center of the tumor. After the second, fourth, and sixth fractions of radiotherapy, vessel permeability increased by 18.4% (p = 0.022), 44.8% (p = 0.0048), and 20.5% (p = 0.25) at the tumor rim. The increase in permeability at the tumor center was not significant after radiotherapy. CONCLUSION: Fractionated radiotherapy increases tumor vascular blood volume and permeability in human non-small-cell lung cancer. We have established the spatial distribution of vascular changes after radiotherapy; greater vascular changes were demonstrated at the tumor rim compared with the center.

Quality of life and behavioral follow-up study of pediatric survivors of craniopharyngioma.

OBJECT: The authors set out to evaluate the quality of life (QOL), social-emotional functioning, and behavioral functioning of children treated surgically for craniopharyngiomas. METHODS: Twelve girls and 17 boys with a mean age at diagnosis of 8 +/- 3.8 years were surgically treated between 1985 and 1998 at the New York University Medical Center. After a mean follow-up period of 6.8 +/- 3.5 years, these 29 patients were administered either the 36-item Short Form Health Survey version 2 or the Child Health Questionnaire-Parent Form to assess QOL, as well as the Achenbach Child Behavior Checklist or Young Adult Checklist to measure social-emotional and behavioral functioning. Patients older than 19 years of age and parents of patients younger than 19 years of age reported low average overall physical QOL, with overall psychosocial QOL in the average range. Behavioral difficulties were noted, including internalizing, attention, somatic, and social difficulties. Further analyses indicated that retrochiasmatic tumor location, recurrence, and additional surgery were associated with poorer outcomes. In contrast, hydrocephalus, tumor size, and sex were not prognostic variables, and patients significantly improved as post-operative time increased. CONCLUSIONS: Attention toward late effects arising after the treatment of pediatric craniopharyngioma, including decreased postoperative physical health and behavioral functioning, is warranted. Future approaches to treatment should consider the documented effects of either gross-total resection or limited surgery followed by cranial irradiation on QOL, with specific evaluation for those with retrochiasmatic tumors, a recurrent tumor, or the need for additional surgery. Psychosocial QOL and social-emotional functioning should be maintained through ongoing counseling and education.