Trait-mediated responses of caterpillar communities to spongy moth outbreaks and subsequent tebufenozide treatments.

Outbreaks of the spongy moth Lymantria dispar can have devastating impacts on forest resources and ecosystems. Lepidoptera-specific insecticides, such as Bacillus thuringiensis var. kurstaki (BTK) and tebufenozide, are often deployed to prevent heavy defoliation of the forest canopy. While it has been suggested that using BTK poses less risk to non-target Lepidoptera than leaving an outbreak untreated, in situ testing of this assumption has been impeded by methodological challenges. The trade-offs between insecticide use and outbreaks have yet to be addressed for tebufenozide, which is believed to have stronger side effects than BTK. We investigated the short-term trade-offs between tebufenozide treatments and no-action strategies for the non-target herbivore community in forest canopies. Over 3 years, Lepidoptera and Symphyta larvae were sampled by canopy fogging in 48 oak stands in southeast Germany during and after a spongy moth outbreak. Half of the sites were treated with tebufenozide and changes in canopy cover were monitored. We contrasted the impacts of tebufenozide and defoliator outbreaks on the abundance, diversity, and functional structure of chewing herbivore communities. Tebufenozide treatments strongly reduced Lepidoptera up to 6 weeks after spraying. Populations gradually converged back to control levels after 2 years. Shelter-building species dominated caterpillar assemblages in treated plots in the post-spray weeks, while flight-dimorphic species were slow to recover and remained underrepresented in treated stands 2 years post-treatment. Spongy moth outbreaks had minor effects on leaf chewer communities. Summer Lepidoptera decreased only when severe defoliation occurred, whereas Symphyta declined 1 year after defoliation. Polyphagous species with only partial host plant overlap with the spongy moth were absent from heavily defoliated sites, suggesting greater sensitivity of generalists to defoliation-induced plant responses. These results demonstrate that both tebufenozide treatments and spongy moth outbreaks alter canopy herbivore communities. Tebufenozide had a stronger and longer lasting impact, but it was restricted to Lepidoptera, whereas the outbreak affected both Lepidoptera and Symphyta. These results are tied to the fact that only half of the outbreak sites experienced severe defoliation. This highlights the limited accuracy of current defoliation forecast methods, which are used as the basis for the decision to spray insecticides.

Salinity reduces site quality and mangrove forest functions. From monitoring to understanding.

Mangroves continue to be threatened across their range by a mix of anthropogenic and climate change-related stress. Climate change-induced salinity is likely to alter the structure and functions of highly productive mangrove systems. However, we still lack a comprehensive understanding of how rising salinity affects forest structure and functions because of the limited availability of mangrove field data. Therefore, based on extensive spatiotemporal mangrove data covering a large-scale salinity gradient, collected from the world's largest single tract mangrove ecosystem - the Bangladesh Sundarbans, we, aimed to examine (QI) how rising salinity influences forest structure (e.g., stand density, diversity, leaf area index (LAI), etc.), functions (e.g., carbon stocks, forest growth), nutrients availability, and functional traits (e.g., specific leaf area, wood density). We also wanted to know (QII) how forest functions interact (direct vs. indirect) with biotic (i.e., stand structure, species richness, etc.) and abiotic factors (salinity, nutrients, light availability, etc.). We also asked (QIII) whether the functional variable decreases disproportionately with salinity and applied the power-law (i.e., Y = a Xb) to the salinity and functional variable relationships. In this study, we found that rises in salinity significantly impede forest growth and produce less productive ecosystems dominated by dwarf species while reducing stand structural properties (i.e., tree height, basal area, dominant tree height, LAI), soil carbon (organic and root carbon), and macronutrient availability in the soil (e.g., NH4+, P, and K). Besides, species-specific leaf area (related to resource acquisition) also decreased with salinity, whereas wood density (related to resource conservation) increased. We observed a declining abundance of the salt-intolerant climax species (Heritiera fomes) and dominance of the salt-tolerant species (Excoecaria agallocha, Ceriops decandra) in the high saline areas. In the case of biotic and abiotic factors, salinity and salinity-driven gap fraction (high transmission of light) had a strong negative impact on functional variables, while nutrients and LAI had a positive impact. In addition, the power-law explained the consistent decline of functional variables with salinity. Our study disentangles the negative effects of salinity on site quality in the Sundarbans mangrove ecosystem, and we recognize that nutrient availability and LAI are likely to buffer the less salt-tolerant species to maintain the ability to sequester carbon with sea-level rise. These novel findings advance our understanding of how a single stressor-salinity-can shape mangrove structure, functions, and productivity and offer decision makers a much-needed scientific basis for developing pragmatic ecosystem management and conservation plans in highly stressed coastal ecosystems across the globe.

11C-methionine PET for grading and prognostication in gliomas: a comparison study with 18F-FDG PET and contrast enhancement on MRI.

UNLABELLED: The aim of this study was to compare the grading and prognostic value of l-[methyl-(11)C]-methionine ((11)C-MET) PET in glioma patients with (18)F-FDG PET and contrast-enhanced MRI. METHODS: Patients (n = 102) with histopathologically confirmed gliomas were followed up for an average of 34.6 ± 3.8 mo after PET. The median survival was 18 ± 4.7 mo in the high-grade glioma group and 58 ± 27 mo in the low-grade glioma group. Patients underwent (18)F-FDG PET, (11)C-MET PET, and MRI in the diagnostic and preoperative stage. The ratio of the mean standardized uptake value in the tumor to mean standardized uptake value in contralateral normal cortex (T/N ratio) was calculated. Kaplan-Meier survival analysis and ANOVA were performed. RESULTS: T/N ratios for (11)C-MET PET and (18)F-FDG PET were significantly higher in high-grade gliomas than in low-grade gliomas (2.15 ± 0.77 vs. 1.56 ± 0.74, P < 0.001, and 0.85 ± 0.61 vs. 0.63 ± 0.37, P < 0.01, respectively). Median survival was 19 ± 5.4 mo in patients with a T/N ratio greater than 1.51 for (11)C-MET PET and 58 ± 26.7 mo in those with a T/N ratio less than 1.51 (P = 0.03). Among the LGGs, median survival was lower in patients with a mean T/N ratio greater than 1.51 for (11)C-MET PET (16 ± 10 mo; 95% confidence interval, 1-36 mo) than in those with a T/N ratio less than 1.51 (P = 0.04). No significant difference in survival in LGGs was based on (18)F-FDG uptake and MRI contrast enhancement. CONCLUSION: (11)C-MET PET can predict prognosis in gliomas and is better than (18)F-FDG PET and MRI in predicting survival in LGGs.

Gallbladder metastasis from malignant melanoma: diagnosis with FDG PET/CT.

Melanoma with metastasis to the gallbladder is sometimes seen on autopsy but is rarely seen in living patients, in part because it is often asymptomatic. A 67-year-old man with a history of malignant melanoma in situ underwent an F-18 FDG PET/CT scan, which showed a gallbladder focus (SUV 16.9). Four months later, on the repeat FDG PET/CT scan, a new lesion in the gallbladder was noted. Laparoscopic cholecystectomy was done and histopathologic findings were consistent with gallbladder metastasis of melanoma. PET/CT detects metastasis at unusual sites accurately and is helpful in correct staging and management of patients with melanoma.

Combined C-11 methionine and F-18 FDG PET imaging in a case of neurosarcoidosis.

PURPOSE: PET scanning of the brain with F-18 FDG and C-11 methionine (MET) is useful for characterizing brain lesions discovered at MRI or CT. Most positive PET scans indicate malignancy. However, this case report demonstrates positive F-18 FDG and C-11 MET PET scans in a patient with a nonmalignant condition, neurosarcoidosis. MATERIALS AND METHODS: We detail the history and evaluation of a 59-year-old woman who presented with ataxia. The patient's evaluation included a contrast-enhanced MRI followed by PET scanning of the brain with C-11 MET and of the brain and trunk with F-18 FDG. The patient subsequently underwent biopsy of a lesion as directed by MRI and PET. RESULTS: The MRI demonstrated multiple enhancing leptomeningeal lesions consistent with metastatic disease. PET with F-18 FDG and C-11 MET demonstrated lesions in both cerebellar hemispheres with F-18 FDG accumulation in the mediastinum and left hilum. Biopsy of a brain lesion directed by MRI and PET revealed sarcoidosis. CONCLUSIONS: In evaluating brain lesions, PET with F-18 FDG and C-11 MET can help localize the lesion best suited for biopsy. However, not all lesions that have increased uptake on C-11 MET or F-18 FDG PET are malignant. Granulomatous inflammatory diseases such as neurosarcoidosis should also be considered in the differential diagnosis.

High 2-deoxy-2[F-18]fluoro-D-glucose uptake on positron emission tomography in hibernoma originally thought to be myxoid liposarcoma.

PURPOSE: The purpose of the study is to describe the rare tumor on 2-deoxy-2[F-18]fluoro-D-glucose (FDG) positron emission tomography (PET). PROCEDURE: A 33-year-old male was diagnosed with high uptake lesion on FDG-PET scanning, which was found to be hibernoma on excision. RESULTS: Hibernoma, originally confused with liposarcoma based on its PET and computed tomography presentation, was excised and correctly identified by pathology. CONCLUSION: Although found to be benign, radiological and FDG-PET scanning results were indistinguishable from malignancy, and biopsy is required to exclude neoplasm.

Functional imaging in Lhermitte-Duclose disease.

PURPOSE: A comprehensive metabolic characterization of a patient with dysplastic gangliocytoma of the cerebellum or Lhermitte-Duclos Disease (LDD) is presented. PROCEDURES: Assessment using 2-deoxy-2-[18F]fluoro-D-glucose (FDG), carbon-11-labeled methionine (11C-MET), carbon-11-labeled choline (11C-Choline) positron emission tomography (PET), and 1H-proton magnetic resonance spectroscopy (MRS) was carried out in a 30-year-old Caucasian woman. RESULTS: FDG-PET revealed hypermetabolism of the tumor. 11C-MET-PET revealed moderate uptake and 11C-Choline showed no uptake. 1H-MRS demonstrated an elevated level of lactate and decreased levels of choline (Cho) and myoinositol. CONCLUSION: Functional imaging in LDD reflects the dual pathological features of neoplasm and hamartoma.

A comparative study on the uptake and incorporation of radiolabeled methionine, choline and fluorodeoxyglucose in human astrocytoma.

PURPOSE: The goal of this investigation was to evaluate uptake and incorporation of 2-deoxy-2-[18F]fluoro-D-glucose (FDG), 11C-methionine, and 11C-choline in 17 patients suspected of grade-II and grade-III tumors using positron emission tomography (PET) and use in vitro astrocytoma cell lines in order to support in vivo findings. METHODS: Seventeen patients with suspected astrocytomas (9 grade-II and 8 grade-III) were studied by PET with FDG and 11C-methionine; and one patient (grade-III) with FDG, 11C-methionine and 11C-choline. Uptake of PET molecular imaging probe was quantitative based on tumor to corresponding contralateral-region uptake ratio, tumor to mean-cortical-uptake ratio, and tumor to white matter uptake ratio. This was correlated with World Health Organization histology grading system and clinical follow-up. Uptake and incorporation of 3H-methionine, 3H-choline and FDG into lipid, RNA, DNA, and protein were investigated in a grade-III human tumor brain-14 astrocytoma cell line. RESULTS: A time-dependent increase in the total uptake of 3H-methionine, 3H-choline and FDG was observed in human tumor brain-14 astrocytoma-III cell line. 3H-methionine was incorporated predominantly into proteins (in excess of 40% at 1 h) while 3H-choline incorporated primarily into lipids (in excess of 60% at 1 hr). Total uptake of FDG was accounted for in the free-pool supernatant fraction. In all patients, PET images of 11C-methionine and FDG provided higher tumor to white matter ratios than tumor to corresponding contra-lateral region ratios and tumor to mean cortical uptake ratios. In grade II patients, FDG did not exhibit significant increase in tumor uptake, while 11C-methionine was a good predictor with ratios of approximately 1.50 +/- 0.48. In grade III patients, both FDG and 11C-methionine exhibited higher ratios than for grade II, with 11C-methionine being the greatest (ratios of 2.50 +/- 0.85), possibly suggesting enhanced protein synthesis. With respect to tumor delineating potential, 11C-choline may be equal to or slightly better than 11C-methionine in the subject evaluated with all three probes. CONCLUSIONS: Results suggest that a combination of FDG and 11C-methionine is useful in the prediction of histological grade of astrocytomas. In addition, 11C-methionine is better than FDG in delineating tumor boundary for low-grade gliomas. In vitro results suggest that 3H-methionine is significantly incorporated into proteins and provides the major driving force in the uptake of 11C-methionine observed in PET images.

Urinary tract infection associated with ureteral stents in renal transplantation.

OBJECTIVES: In the mid 1980s, ureteral stents were used in renal transplantation when ureteral injury had occurred. Subsequently, it was shown that routine ureteral stent placement at the time of transplantation reduced urological complications. We carried out a chart review on renal transplant patients and noted which patients developed urinary tract infections (UTIs) with stents in place, and whether these infections ultimately affected transplant outcome. We sought to distinguish subgroups of patients who were more likely to develop infection and to identify the optimum time for stent removal. PATIENTS AND METHODS: We performed a retrospective chart review of 213 patients who underwent renal transplantation in 1994 and 1995. Adequate follow-up information was available on 167 patients with intraoperative stent placement. Of these 167 patients, 4 patients expired and 8 required transplant nephrectomy due to complications unrelated to the stent. RESULTS: In total, 35 patients (22.6%) developed a post-operative UTI. One infection occurred during the first week following transplant, 3 developed within 2 weeks, and importantly, the remaining 32 infections occurred more than 2 weeks after transplant. An increase in infections in diabetics (25.7%) as compared to other transplant recipients (20.2%) was noted. Patients with cadaveric renal transplants are also at higher risk of UTI (24%) compared to those with living related donors (15%). CONCLUSION: The use of ureteral stents is safe, but is associated with a UTI rate of 22.6%. To reduce infection rates, we recommend stent removal within 14 days and earlier if possible, particularly in diabetic patients who have received a cadaveric renal transplant.