Reverse metabolomics for the discovery of chemical structures from humans

Determining the structure and phenotypic context of molecules detected in untargeted metabolomics experiments remains challenging. Here we present reverse metabolomics as a discovery strategy, whereby tandem mass spectrometry spectra acquired from newly synthesized compounds are searched for in public metabolomics datasets to uncover phenotypic associations. To demonstrate the concept, we broadly synthesized and explored multiple classes of metabolites in humans, including N-acyl amides, fatty acid esters of hydroxy fatty acids, bile acid esters and conjugated bile acids. Using repository-scale analysis1,2, we discovered that some conjugated bile acids are associated with inflammatory bowel disease (IBD). Validation using four distinct human IBD cohorts showed that cholic acids conjugated to Glu, Ile/Leu, Phe, Thr, Trp or Tyr are increased in Crohn's disease. Several of these compounds and related structures affected pathways associated with IBD, such as interferon-γ production in CD4+ T cells3 and agonism of the pregnane X receptor4. Culture of bacteria belonging to the Bifidobacterium, Clostridium and Enterococcus genera produced these bile amidates. Because searching repositories with tandem mass spectrometry spectra has only recently become possible, this reverse metabolomics approach can now be used as a general strategy to discover other molecules from human and animal ecosystems.

Commensal bacteria promote type I interferon signaling to maintain immune tolerance in mice

Type I interferons (IFNs) exert a broad range of biological effects important in coordinating immune responses, which have classically been studied in the context of pathogen clearance. Yet, whether immunomodulatory bacteria operate through IFN pathways to support intestinal immune tolerance remains elusive. Here, we reveal that the commensal bacterium, Bacteroides fragilis, utilizes canonical antiviral pathways to modulate intestinal dendritic cells (DCs) and regulatory T cell (Treg) responses. Specifically, IFN signaling is required for commensal-induced tolerance as IFNAR1-deficient DCs display blunted IL-10 and IL-27 production in response to B. fragilis. We further establish that IFN-driven IL-27 in DCs is critical in shaping the ensuing Foxp3+ Treg via IL-27Rα signaling. Consistent with these findings, single-cell RNA sequencing of gut Tregs demonstrated that colonization with B. fragilis promotes a distinct IFN gene signature in Foxp3+ Tregs during intestinal inflammation. Altogether, our findings demonstrate a critical role of commensal-mediated immune tolerance via tonic type I IFN signaling.

Identification of a damage-associated molecular pattern (DAMP) receptor and its cognate peptide ligand in sweet potato (Ipomoea batatas)

Sweet potato (Ipomoea batatas) is an important tuber crop, but also target of numerous insect pests. Intriguingly, the abundant storage protein in tubers, sporamin, has intrinsic trypsin protease inhibitory activity. In leaves, sporamin is induced by wounding or a volatile homoterpene and enhances insect resistance. While the signalling pathway leading to sporamin synthesis is partially established, the initial event, perception of a stress-related signal is still unknown. Here, we identified an IbLRR-RK1 that is induced upon wounding and herbivory, and related to peptide-elicitor receptors (PEPRs) from tomato and Arabidopsis. We also identified a gene encoding a precursor protein comprising a peptide ligand (IbPep1) for IbLRR-RK1. IbPep1 represents a distinct signal in sweet potato, which might work in a complementary and/or parallel pathway to the previously described hydroxyproline-rich systemin (HypSys) peptides to strengthen insect resistance. Notably, an interfamily compatibility in the Pep/PEPR system from Convolvulaceae and Solanaceae was identified.

IL-22 initiates an IL-18-dependent epithelial response circuit to enforce intestinal host defence

IL-18 is emerging as an IL-22-induced and epithelium-derived cytokine which contributes to host defence against intestinal infection and inflammation. In contrast to its known role in Goblet cells, regulation of barrier function at the molecular level by IL-18 is much less explored. Here we show that IL-18 is a bona fide IL-22-regulated gate keeper for intestinal epithelial barrier. IL-22 promotes crypt immunity both via induction of phospho-Stat3 binding to the Il-18 gene promoter and via Il-18 independent mechanisms. In organoid culture, while IL-22 primarily increases organoid size and inhibits expression of stem cell genes, IL-18 preferentially promotes organoid budding and induces signature genes of Lgr5+ stem cells via Akt-Tcf4 signalling. During adherent-invasive E. coli (AIEC) infection, systemic administration of IL-18 corrects compromised T-cell IFNγ production and restores Lysozyme+ Paneth cells in Il-22-/- mice, but IL-22 administration fails to restore these parameters in Il-18-/- mice, thereby placing IL-22-Stat3 signalling upstream of the IL-18-mediated barrier defence function. IL-18 in return regulates Stat3-mediated anti-microbial response in Paneth cells, Akt-Tcf4-triggered expansion of Lgr5+ stem cells to facilitate tissue repair, and AIEC clearance by promoting IFNγ+ T cells.

[Genetic characterization analysis of the whole genome sequence of Coxsackievirus A8 associated with hand, foot and mouth disease in China]

Objective: To study the genomic sequence of Coxsackievirus A8 (CV-A8) associated with hand, foot and mouth disease (HFMD) from 2013 to 2018 in China and to analyze the genetic evolution of each coding region of the full-length genome. Methods: The genome sequences of 11 CV-A8 strains isolated from patients with HFMD in different regions of China from 2013 to 2018 were determined. Sequence alignment and genetic evolution analysis were performed by Sequencher 5.0 and MEGA 7.0 software, etc. Results: Sequence alignment showed that the genome length of 11 CV-A8 strains ranged from 7 393 bp to 7 400 bp. There was no base insertion or deletion in the coding region compared with the prototype strain, but there were individual base insertion or deletion in the non-coding region. The nucleotide and amino acid similarities in the VP1 region of 11 CV-A8 strains were 78.3%-98.6% and 92.6%-99.7%, respectively, and the nucleotide and amino acid sequences identities with the CV-A8 prototype strain were 78.3%-98.2% and 92.6%-99.7%, respectively. Based on the phylogenetic analysis of VP1 region sequences, the CV-A8 can be divided into five genotypes: A, B, C, D and E. The 11 CV-A8 strains in this study belonged to genotypes C (1 strain), D (2 strains) and E (8 strains). The nucleotide and amino acid similarities of 11 CV-A8 full-length genomes were 81.3%-98.8% and 95.9%-99.5%, respectively. The phylogenetic tree of the P2 region showed that the eight E genotypes CV-A8 had the closest evolutionary distance with CV-A4, CV-A14, and CV-A16. The phylogenetic tree of the P3 region showed that the eight E genotypes CV-A8 had a close evolutionary distance with CV-A5, CV-A16, CV-A14 and CV-A4. Conclusions: The 11 CV-A8 stains in this study showed significant intra-genotype diversity in capsid region and recombinant diversity in non-capsid region which indicated that CV-A8 quasispecies were still undergoing dynamics variation. CV-A8 may become an important pathogen of HFMD and the monitoring of CV-A8 needs to be further strengthened.

Lumenal Galectin-9-Lamp2 interaction regulates lysosome and autophagy to prevent pathogenesis in the intestine and pancreas

Intracellular galectins are carbohydrate-binding proteins capable of sensing and repairing damaged lysosomes. As in the physiological conditions glycosylated moieties are mostly in the lysosomal lumen but not cytosol, it is unclear whether galectins reside in lysosomes, bind to glycosylated proteins, and regulate lysosome functions. Here, we show in gut epithelial cells, galectin-9 is enriched in lysosomes and predominantly binds to lysosome-associated membrane protein 2 (Lamp2) in a Asn(N)-glycan dependent manner. At the steady state, galectin-9 binding to glycosylated Asn175 of Lamp2 is essential for functionality of lysosomes and autophagy. Loss of N-glycan-binding capability of galectin-9 causes its complete depletion from lysosomes and defective autophagy, leading to increased endoplasmic reticulum (ER) stress preferentially in autophagy-active Paneth cells and acinar cells. Unresolved ER stress consequently causes cell degeneration or apoptosis that associates with colitis and pancreatic disorders in mice. Therefore, lysosomal galectins maintain homeostatic function of lysosomes to prevent organ pathogenesis.

Cloning and overexpression of the ascorbate peroxidase gene from the yam (Dioscorea alata) enhances chilling and flood tolerance in transgenic Arabidopsis

Minghuai 1 (MH1) is a yam (Dioscorea alata) cultivar with high tolerance to flooding but sensitivity to chilling. MH1 responded differently to chilling and flooding according to various physiological parameters and antioxidant enzymes. Flooding led to an increase in ascorbate peroxidase (APX) activity in both roots and leaves, while chilling did not affect APX activity. The full length DaAPX ORF sequence from MH1 (750 bp) was then cloned. Phylogenetic analysis showed that plant cytosolic APXs into four major clusters and DaAPX was closely related to Oncidium. The DaAPX gene driven by a 35S promoter was transferred into Arabidopsis. The gene expression and enzyme activity of APX in the DaAPX transgenic lines 1-3 were significantly higher than in wild type (WT) plants. Compared to WT plants, seedling growth characteristics were significantly better in all transgenic lines under chilling, flooding, and oxidative stresses, indicating that the overexpression of DaAPX in Arabidopsis enhanced tolerance to several abiotic stresses. MH1 plants supplied with H₂O₂ presented an increase in the activity of APX leading to enhanced tolerance to chilling. Functional characterization of the APX gene should improve our understanding of the chilling- and flood-response mechanism in the yam.

[Mid-term multi-center outcomes of bilateral radial artery as conduits in coronary artery bypass grafting]

Objective: To evaluate the mid-term outcomes of bilateral radial artery (BRA) grafts in coronary artery bypass grafting (CABG). Methods: All perioperative medical records and follow-up results of CABG with BRA grafts in multi-centers of China were analyzed retrospectively. Results: A total of 211 patients (170 males and 41 females) underwent CABG grafting with BRA conduits between August 2013 and September 2018, with a mean age of (56.5±9.7) years old (rang 41 to 73 years). There were 161 cases of triple-vessel disease and 50 cases of two-vessel disease. Ninety patients had diabetes mellitus (DM), 35 patients with peripheral vascular disease, 4 patients with chronic obstructive pulmonary disease and 11 with heart valve disease. Two patients underwent off-pump CABG and 209 patients accepted on-pump CABG with commitment valve surgery. There were 210 cases of total arterial revascularization and 161 cases using left thoracic artery conduits, with a graft number of 2-4 (2.7±0.9). No operation-related death occurred, atrial fibrillation happened in 12 patients, hemothorax in 7 cases, and forearm hematoma in one case, hypoxemia in 13 cases and pneumonia in one case. The duration of mechanical ventilation was (8.3±4.7) hours and the mean hospital length of stay was (7.1±2.9) days. Follow-up was completed in 191 patients (90.52%) with a duration of 3-59 (35.5±9.3) months. The mean left ventricular ejection fraction at 3 months after operation was significantly improved, compared to that of the pre-operation (61.0%±7.2% vs 47.1%±5.3%, P=0.017). All patients survived, except that one died from brain injury. No major cardiac events occurred, with a cumulative survival rate of 100% at 1 year and 99.53% at 3 year after operation, respectively. It was showed in coronary CT angiography (CTA) examination that all grafts in 132 patients were patent at the mean follow-up duration of (21.5±6.4) months. Conclusions: BRA grafts as arterial conduit in CABG are proved to be safe, easy for total arterial revascularization and have good mid-term clinical results.

ATF3 Sustains IL-22-Induced STAT3 Phosphorylation to Maintain Mucosal Immunity Through Inhibiting Phosphatases

In gut epithelium, IL-22 transmits signals through STAT3 phosphorylation (pSTAT3) which provides intestinal immunity. Many components in the IL-22-pSTAT3 pathway have been identified as risk factors for inflammatory bowel disease (IBD) and some of them are considered as promising therapeutic targets. However, new perspectives are still needed to understand IL-22-pSTAT3 signaling for effective clinical interventions in IBD patients. Here, we revealed activating transcription factor 3 (ATF3), recently identified to be upregulated in patients with active IBD, as a crucial player in the epithelial IL-22-pSTAT3 signaling cascade. We found ATF3 is central to intestinal homeostasis and provides protection during colitis. Loss of ATF3 led to decreased crypt numbers, more shortened colon length, impaired ileal fucosylation at the steady state, and lethal disease activity during DSS-induced colitis which can be effectively ameliorated by rectal transplantation of wild-type colonic organoids. Epithelial stem cells and Paneth cells form a niche to orchestrate epithelial regeneration and host-microbe interactions, and IL-22-pSTAT3 signaling is a key guardian for this niche. We found ATF3 is critical for niche maintenance as ATF3 deficiency caused compromised stem cell growth and regeneration, as well as Paneth cell degeneration and loss of anti-microbial peptide (AMP)-producing granules, indicative of malfunction of Paneth/stem cell network. Mechanistically, we found IL-22 upregulates ATF3, which is required to relay IL-22 signaling leading to STAT3 phosphorylation and subsequent AMP induction. Intriguingly, ATF3 itself does not act on STAT3 directly, instead ATF3 regulates pSTAT3 by negatively targeting protein tyrosine phosphatases (PTPs) including SHP2 and PTP-Meg2. Furthermore, we identified ATF3 is also involved in IL-6-mediated STAT3 activation in T cells and loss of ATF3 leads to reduced capacity of Th17 cells to produce their signature cytokine IL-22 and IL-17A. Collectively, our results suggest that via IL-22-pSTAT3 signaling in the epithelium and IL-6-pSTAT3 signaling in Th17 cells, ATF3 mediates a cross-regulation in the barrier to maintain mucosal homeostasis and immunity.

[An analysis of electrocochleography in patients with OSAHS]

Objective:To investigate the values of electrocochleograph（ECochG）in patients with OSAHS. Method:ECochG was performed in 31 (62 ears) OSAHS patients (moderately 5 cases, severely 26 cases) and 28 healthy adults (56 ears). AP latency ，AP amplitude and SP/AP were measured and analyzed. Result:There was no difference between the two groups in SP/AP amplitude ratio（P>0.05） while both AP latency（P<0.05） and AP amplitude（P<0.05） were significantly different. Conclusion:ECochG can confirm the damage of cochlear and auditory nerve near the cochlear segment in patients with moderate to severe OSAHS.

Galectin-9 Is Critical for Mucosal Adaptive Immunity through the T Helper 17-IgA Axis

Impairment of the intestinal mucosal immunity significantly increases the risk of acute and chronic diseases. IgA plays a major role in humoral mucosal immunity to provide protection against pathogens and toxins in the gut. Here, we investigated the role of endogenous galectin-9, a tandem repeat-type β-galactoside-binding protein, in intestinal mucosal immunity. By mucosal immunization of Lgals9^-/- and littermate control mice, it was found that lack of galectin-9 impaired mucosal antigen-specific IgA response in the gut. Moreover, Lgals9^-/- mice were more susceptible to developing watery diarrhea and more prone to death in response to high-dose cholera toxin. The results indicate the importance of galectin-9 in modulating intestinal adaptive immunity. Furthermore, bone marrow chimera mice were established, and galectin-9 in hematopoietic cells was found to be critical for adaptive IgA response. In addition, immunized Lgals9^-/- mice exhibited lower expression of Il17 and fewer T helper 17 (Th17) cells in the lamina propria, implying that the Th17-IgA axis is involved in this mechanism. Taken together, these findings suggest that galectin-9 plays a role in mucosal adaptive immunity through the Th17-IgA axis. By manipulating the expression or activity of galectin-9, intestinal mucosal immune response can be altered and may benefit the development of mucosal vaccination.

The Sweet Potato NAC-Domain Transcription Factor IbNAC1 Is Dynamically Coordinated by the Activator IbbHLH3 and the Repressor IbbHLH4 to Reprogram the Defense Mechanism against Wounding

IbNAC1 is known to activate the defense system by reprogramming a genetic network against herbivory in sweet potato. This regulatory activity elevates plant defense potential but relatively weakens plants by IbNAC1-mediated JA response. The mechanism controlling IbNAC1 expression to balance plant vitality and survival remains unclear. In this study, a wound-responsive G-box cis-element in the IbNAC1 promoter from -1484 to -1479 bp was identified. From a screen of wound-activated transcriptomic data, one transcriptional activator, IbbHLH3, and one repressor, IbbHLH4, were selected that bind to and activate or repress, respectively, the G-box motif in the IbNAC1 promoter to modulate the IbNAC1-mediated response. In the early wound response, the IbbHLH3-IbbHLH3 protein complex binds to the G-box motif to activate IbNAC1 expression. Thus, an elegant defense network is activated against wounding stress. Until the late stages of wounding, IbbHLH4 interacts with IbbHLH3, and the IbbHLH3-IbbHLH4 heterodimer competes with the IbbHLH3-IbbHLH3 complex to bind the G-box and suppress IbNAC1 expression and timely terminates the defense network. Moreover, the JAZs and IbEIL1 proteins interact with IbbHLH3 to repress the transactivation function of IbbHLH3 in non-wounded condition, but their transcription is immediately inhibited upon early wounding. Our work provides a genetic model that accurately switches the regulatory mechanism of IbNAC1 expression to adjust wounding physiology and represents a delicate defense regulatory network in plants.

Toward live-cell imaging of dopamine neurotransmission with fluorescent neurotransmitter analogues

We report a novel 'fluorescent dopamine' that possesses essential features of natural dopamine. Our method is simple and is readily extended to monoamine neurotransmitters such as L-norepinephrine, serotonin and GABA, providing a more practical approach. Because of its compatibility with sensitive fluorescent measurements, we envisage that our approach will have a broad range of applications in neural research.

[The evaluation of hearing aid effect in presbycusis]

Objective:To evaluate the effect of hearing aid in presbycusis. Method:Using the method of international outcome inventory for hearing aids(IOI-HA)and medium acoustic intensity(65 dBSPL) word recognition score(WRS), to evaluate the effect of hearing aid in moderate and severe presbycusis. Result:After the hearing aid of moderate presbycusis, The improved value of monosyllabic words and recognition rate in quite and noise statement(SNR=5) were 31.15%, 23.21%, 44.11%.However, improved values in severe presbycusis were 37.51%, 48.47%，50.17%, before and after hearing aid, the difference of the improved average value was statistically significant(P <0.05); Both the moderate and severe presbycusis were satisfacted with hearing aid.The IO-HA scores of moderate and severe presbycusis ranged from 15 to 34.The difference of IOIHA score of moderate and severe presbycusis had no statistical significance(P >0.05); moderate and severe presbycusis with high satisfaction with HA of quiet statement,and low satisfaction of monosyllabic words listening, and the degree of satisfaction was higher in patients with moderate to severe hearing loss in noise statement.Conclusion:Speech audiometry is an important method to assess the effect of hearing aid; IOI-HA is a timeconsuming short, subjective method.The combine of multiple evaluations have guiding significance to debugging of hearing aid expected effect and hearing aid device.

[Necessity of repeated roll test in horizontal semicircular canalithasis positioned diagnosis]

OBJECTIVE

To investigate the influence of repeated roll test in horizontal semicircular canalithasis(HSC-Can) positioned diagnosis, so as to investigate the cecessity of repeated roll test.

METHODS

The patients with a chief complaint of positional vertigo accepted two consecutive cycles roll test, the evoked nystagmus characteristics of each cycle recorded by video-nystagmuograph(VNG), whose direction, intensity, time and other parameters characteristics were analyzed in 51 HSC-Can.

RESULTS

Horizontal nystagmus in the same direction with turning were induced in HSC-Can roll test. In 51 HSC-Can, roll test cycle 1 and cycle 2 induced nystagmus same strength side in 26 cases(51.0%), of which 19 cases with stronger nystagmus intensity in cycle 2, another 7 cases were weaker; the opposite strength side of the two loops induced nystagmus, and cycle 1 evoked nystagmus intensity were weaker than cycle 2, based on cycle 2 results determined HSC-Can affected side in 25 cases (49.0%). Lesion and normal side in cycle 1 induced nystagmus duration (x±s, the same below) were (13.4±11.5)s and (14.1±9.9)s, respectively intensity (18.1±22.4)°/s and (13.0±12.0)°/s; as in cycle 2 induced nystagmus duration was (20.7±10.2)s and (18.0±12.0)s, strength respectively(40.4±28.0)°/s and (15.6 ±11.2)°/s. Cycle 2 ipsilateral rotor position evoked nystagmus showed longer duration and stronger intensity than cycle 1. Between two cycle induced ipsilateral nystagmus duration, intensity differences were statistically significant (t values were -4.233 and -5.154, P=0.000). 51 HSC-Can patients, 44 patients selected repositioning maneuver, after 1-2 times of maneuver, 41 cases (93.2%) showed complete resolution of symptoms, all cases's symptoms were improved; other 7 patients selected medication only.

CONCLUSION

The proposed suspicious HSC-Can patients should receive at least two cycles roll test, and mainly in the second cycle could determine the location of the responsible semicircular canals.

Abstract 186: Novel Secondary Multifocal No-Reflow Phenomenon Associated with Activated Leukocyte-induced Microcirculatory Obstruction

Background: No-reflow may occur early after reperfusion of ischemic tissues. In a rat model of hepatic ischemia and reperfusion (IR), delayed multifocal no-reflow was observed hours after initial restoration of circulation. We herein sought to characterize this novel phenomenon and investigate its underlying pathophysiological mechanism.

Methods: Hepatic IR of male wistar rats was induced by clamping hepatic artery and portal vein for 60 min, followed by release of the clamp for reperfusion. Intravital optical microscopy was employed to image microcirculation (FITC-dextran), cellular hypoxia-reoxygenation (autofluorescence of mitochondrial flavoproteins), extracellular DNA (propidium iodide, PI) and the interactions among leukocytes, platelets and endothelium.

Results: Multifocal no-reflow was observed in vivo at the early stage of reperfusion revealed by no recovery of microcirculation and cellular autofluorescence. Interestingly, such no-reflow phenomenon recurred sporadically and remittently about 3 h after initial restoration of circulation. This novel secondary no-reflow was associated with recurrent microcirculatory obstruction caused by stagnation of blood cells. Such obstruction was triggered by activated leukocytes as evidenced by their adhesion with platelets and migration along endothelium. Extracellular DNA near the obstructed sinusoids indicates involvement of neutrophil-extracellular traps (NET).

Conclusions: Secondary multifocal no-reflow may occur hours after initial reperfusion. With activated leukocytes and NET playing key roles, the pathogenic mechanism differs distinctly from that of immediate no-reflow and may implicate alternative targets for therapeutic interventions.

SAHA attenuates sevoflurane-induced learning and memory impairments in fetal mice

Previous studies have found that children with multiple exposures to anesthesia at an early age are at increased risk of learning and memory impairment. Sevoflurane is the most commonly used inhalational anesthetic for general anesthesia in children. Multiple exposures to sevoflurane have been shown to induce neuroinflammation, inhibit neurogenesis, and cause subsequent learning and memory impairments in fetal mice. Histone-tail acetylation has been implicated in memory formation. In this study, we employed suberanilohydroxamic acid (SAHA), an inhibitor of histone deacetylases, to treat sevoflurane-induced learning and memory impairments. Six-day-old C57BL/6 mice were exposed to sevoflurane for 2 h daily for 3 days. Morris water maze test performed to evaluate learning and memory impairments and the expression of genes related in to synaptic remodeling/plasticity, or regulated by neuronal activity or the cell cycle were detected by real-time PCR. We found that SAHA attenuated sevoflurane-induced learning and memory impairments in fetal mice. Our findings suggest that SAHA may have potential as a therapeutic agent for preventing or treating the neurotoxicity associated with anesthesia.

Molecular imaging of ischemia and reperfusion in vivo with mitochondrial autofluorescence

Ischemia and reperfusion (IR) injury constitutes a pivotal mechanism of tissue damage in pathological conditions such as stroke, myocardial infarction, vascular surgery, and organ transplant. Imaging or monitoring of the change of an organ at a molecular level in real time during IR is essential to improve our understanding of the underlying pathophysiology and to guide therapeutic strategies. Herein, we report molecular imaging of a rat model of hepatic IR with the autofluorescence of mitochondrial flavins. We demonstrate a revelation of the histological characteristics of a liver in vivo with no exogenous stain and show that intravital autofluorescent images exhibited a distinctive spatiotemporal variation during IR. The autofluorescence decayed rapidly from the baseline immediately after 20-min ischemia (approximately 30% decrease in 5 min) but recovered gradually during reperfusion (to approximately 99% of the baseline 9 min after the onset of reperfusion). The autofluorescent images acquired during reperfusion correlated strongly with the reperfused blood flow. We show further that the autofluorescence was produced predominantly from mitochondria, and the distinctive autofluorescent variation during IR was mechanically linked to the altered balance between the flavins in the oxidized and reduced forms residing in the mitochondrial electron-transport chain. Our approach opens an unprecedented route to interrogate the deoxygenation and reoxygenation of mitochondria, the machinery central to the pathophysiology of IR injury, with great molecular specificity and spatiotemporal resolution and can be prospectively translated into a medical device capable of molecular imaging. We envisage that the realization thereof should shed new light on clinical diagnostics and therapeutic interventions targeting IR injuries of not only the liver but also other vital organs including the brain and heart.

Living status in patients over 85 years of age after TUVRP

INTRODUCTION

To evaluate surgical risk and post-operative quality of living status in patients over 85 years of age after transurethral vaporization resection of the prostate (TUVRP).

METHODS

Sixty patients over 85 years of age underwent TUVRP were compared with 228 patients less than the age of 80 years. Group A was 60 patients greater than 85 years of age, Group B was 137 patients from 71 to 79 years of age, and Group C was 91 patients from 60 to 70 years of age.

RESULTS

In Group A, pre-operative ASA grade was higher than the other two groups, compared with Group C, p < 0.01. Operating time was 40.03 ± 18.90 min, compared in the three groups, p > 0.05. Follow-up was obtained in 49 (81.67%) patients; of them 10 patients were deaths with a survival time of 22.90 ± 11.14 months. In the 39 survivors, post-operative IPSS score was 11.17 ± 6.9, compared with Group B, p > 0.05 and Group C, p < 0.01. Quality of Life (QOL) index was 1.11 ± 0.80, compared with Group B, p < 0.001 and Group C, p < 0.01. Barthel Index score in 16 patients was >60 and the score was 82.81 ± 8.56 pre-operatively. The patients with >60 were increased to 19 cases and the score was improved to 90.93 ± 7.58 (p < 0.001) in follow-up.

CONCLUSION

Surgical risk in patients over 85 years of age was higher than patients less than the age of 80 years. A safety TUVRP could improve their voiding function and activities of daily living.

Pancreatic head mass from metastatic meningeal hemangiopericytoma

Purpose. To illustrate the propensity of meningeal hemangiopericytoma to spread extraneurally, as a distinction to the ordinary meningioma.Patients or subjects. A patient with long history of meningeal hemangiopericytoma was reported.Methods. A case report on meningeal hemangiopericytoma with a literature review was presented.Results. The patient has multiple local recurrence as well as distant metastases.This is the first case report of metastatic meningeal hemangiopericytoma causing compression of the pancreatic head.The patient also has biopsy-proven pulmonary metastases.The patient received both local and systemic therapy.Discussion. It is important to recognize the distinctive features differentiating meningeal hemangiopericytoma from meningioma. The positive impact of clinico-pathological correlation on patient management is emphasized.

Effects of microwave radiation and conductive heating on Tribolium castaneum microstructure

Microwave radiation and conductive heating were used to completely kill adult Tribolium castaneum (Coleoptera: Tenebrionidae) in wheat flour to protect the flour during storage without significantly effecting its quality. The microstructure of T. castaneum was analyzed to reveal the mechanisms leading to death under microwave and heat treatments. Microwave radiation and conductive heating had different effects on the microstructure of the cuticle of adult T. castaneum and on the ultrastructure of the cells of the epidermis, fat body, and midgut. Both treatments caused a large cavity to appear in the nucleus and the disappearance of mitochondria and the Golgi apparatus. After microwave treatment, there was little change in the surface microstructure but the epidermis was of uneven thickness and the four outer layers of the cuticle were thinner. Nuclear size was essentially unchanged, but fat body cells were fewer and coalesced together. In contrast, conductive heating led to a disordered arrangement of cells on the surface of T. castaneum and indistinct boundaries between layers of the cuticle. The nuclei were enlarged and the fat body cells noticeably fewer and indistinct with a scattered distribution. Thus, microwave treatment produced less severe effects on the surface microstructure and cellular ultrastructure of T. castaneum than did conductive heating. It is concluded that these cellular and surface changes were responsible for the death of T. castaneum.

Interaction between zonal populations of articular chondrocytes suppresses chondrocyte mineralization and this process is mediated by PTHrP

OBJECTIVE

Articular cartilage is separated from subchondral bone by the tidemark and a calcified cartilage zone. Advancement of the calcified region and tidemark duplication are both hallmarks of osteoarthritis (OA). Currently the mechanisms controlling post-natal articular cartilage mineralization are poorly understood. The objective of this study is to test the hypothesis that cellular communication between different cartilage layers regulates articular chondrocyte mineralization.

DESIGN

Co-culture models were established to evaluate the interaction of chondrocytes derived from the surface, middle and deep zones of articular cartilage. The cultures were stimulated with triiodothyronine (T3) to promote chondrocyte hypertrophy. The effects of zonal chondrocyte interactions on chondrocyte mineralization were examined over time.

RESULTS

Co-culture of deep zone chondrocytes (DZCs) with surface zone chondrocytes (SZCs) suppressed the T3-induced increase in alkaline phosphatase (ALP) activity and related mineralization. Moreover, SZC-DZC co-culture was associated with a significantly higher parathyroid hormone-related peptide (PTHrP) expression when compared to controls. When PTHrP(1-40) was added to the DZC-only culture, it suppressed DZC ALP activity similar to the inhibition observed in co-culture with SZC. In addition, treatment with PTHrP reversed the effect of T3 stimulation on the expression of hypertrophic markers (Indian hedgehog, ALP, matrix metalloproteinases-13, Type X collagen) in the DZC cultures. Moreover, blocking the action of PTHrP significantly increased ALP activity in SZC+DZC co-culture.

CONCLUSION

Our findings demonstrate the role of zonal chondrocyte interactions in regulating cell mineralization and provide a plausible mechanism for the post-natal regulation of articular cartilage matrix organization. These findings also have significant implications in understanding the pathology of articular cartilage as well as devising strategies for functional cartilage repair.

The treatment of primary and metastatic renal cell carcinoma (RCC) with image-guided stereotactic body radiation therapy (SBRT)

PURPOSE

Brain metastases from renal cell carcinoma (RCC) have been successfully treated with stereotactic radiosurgery (SRS). Metastases to extra-cranial sites may be treated with similar success using stereotactic body radiation therapy (SBRT), where image-guidance allows for the delivery of precise high-dose radiation in a few fractions. This paper reports the authors' initial experience with image-guided SBRT in treating primary and metastatic RCC.

MATERIALS AND METHODS

The image-guided Brainlab Novalis stereotactic system was used. Fourteen patients with 23 extra-cranial metastatic RCC lesions (orbits, head and neck, lung, mediastinum, sternum, clavicle, scapula, humerus, rib, spine and abdominal wall) and two patients with biopsy-proven primary RCC (not surgical candidates) were treated with SBRT (24-40 Gy in 3-6 fractions over 1-2 weeks). All patients were immobilised in body cast or head and neck mask. Image-guidance was used for all fractions. PET/CT images were fused with simulation CT images to assist in target delineation and dose determination. SMART (simultaneous modulated accelerated radiation therapy) boost approach was adopted. 4D-CT was utilised to assess tumour/organ motion and assist in determining planning target volume margins.

RESULTS

Median follow-up was nine months. Thirteen patients (93%) who received SBRT to extra-cranial metastases achieved symptomatic relief. Two patients had local progression, yielding a local control rate of 87%. In the two patients with primary RCC, tumour size remained unchanged but their pain improved, and their renal function was unchanged post SBRT. There were no significant treatment-related side effects.

CONCLUSION

Image-guided SBRT provides excellent symptom palliation and local control without any significant toxicity. SBRT may represent a novel, non-invasive, nephron-sparing option for the treatment of primary RCC as well as extra-cranial metastatic RCC.

Optical breakdown for silica and silicon with double femtosecond laser pulses

The optical breakdown thresholds (OBTs) of typical dielectric and semiconductor materials are measured using double 40-fs laser pulses. By measuring the OBTs with different laser energy and different time delays between the two pulses, we found that the total energy of breakdown decrease for silica and increase for silicon with the increase of the first pulse energy.

Extracellular matrix production by human osteoblasts cultured on biodegradable polymers applicable for tissue engineering

The nature of the extracellular matrix (ECM) is crucial in regulating cell functions via cell-matrix interactions, cytoskeletal organization, and integrin-mediated signaling. In bone, the ECM is composed of proteins such as collagen (CO), fibronectin (FN), laminin (LM), vitronectin (VN), osteopontin (OP) and osteonectin (ON). For bone tissue engineering, the ECM should also be considered in terms of its function in mediating cell adhesion to biomaterials. This study examined ECM production, cytoskeletal organization, and adhesion of primary human osteoblastic cells on biodegradable matrices applicable for tissue engineering, namely polylactic-co-glycolic acid 50:50 (PLAGA) and polylactic acid (PLA). We hypothesized that the osteocompatible, biodegradable polymer surfaces promote the production of bone-specific ECM proteins in a manner dependent on polymer composition. We first examined whether the PLAGA and PLA matrices could support human osteoblastic cell growth by measuring cell adhesion at 3, 6 and 12h post-plating. Adhesion on PLAGA was consistently higher than on PLA throughout the duration of the experiment, and comparable to tissue culture polystyrene (TCPS). ECM components, including CO, FN, LM, ON, OP and VN, produced on the surface of the polymers were quantified by ELISA and localized by immunofluorescence staining. All of these proteins were present at significantly higher levels on PLAGA compared to PLA or TCPS surfaces. On PLAGA, OP and ON were the most abundant ECM components, followed by CO, FN, VN and LN. Immunofluorescence revealed an extracellular distribution for CO and FN, whereas OP and ON were found both intracellularly as well as extracellularly on the polymer. In addition, the actin cytoskeletal network was more extensive in osteoblasts cultured on PLAGA than on PLA or TCPS. In summary, we found that osteoblasts plated on PLAGA adhered better to the substrate, produced higher levels of ECM molecules, and showed greater cytoskeletal organization than on PLA and TCPS. We propose that this difference in ECM composition is functionally related to the enhanced cell adhesion observed on PLAGA. There is initial evidence that specific composition of the PLAGA polymer favors the ECM. Future studies will seek to optimize ECM production on these matrices for bone tissue engineering applications.

A dual-snake model of high penetrability for ultrasound image boundary extraction

Most deformable models require the initial contour to be placed close to the boundary of the object of interest for boundary extraction of ultrasound (US) images, which is impractical in many clinical applications. To allow a distant initial contour, a new dual-snake model promising high penetrability through the interference of the noises is proposed in this paper. The proposed dual-snake model features a new far-reaching external force, called the discrete gradient flow, a connected component-weighted image force, and an effective stability evaluation of two underlying snakes. The experimental results show that, with a distant initial contour, the mean distance from the derived boundary to the desired boundary is less than 1.4 pixels, and most snake elements are within 2.7 pixels of the desired boundaries for the synthetic images with CNR > or =1. For the clinical US images, the mean distance is less than 1.9 pixels, and most snake elements are within 3 pixels of the desired boundaries.

Phase I/II trial evaluating combined radiotherapy and in situ gene therapy with or without hormonal therapy in the treatment of prostate cancer--a preliminary report

PURPOSE

To report the preliminary results of a Phase I/II study combining radiotherapy and in situ gene therapy (adenovirus/herpes simplex virus thymidine kinase gene/valacyclovir) with or without hormonal therapy in the treatment of prostate cancer.

METHODS AND MATERIALS

Arm A: low-risk patients (T1-T2a, Gleason score <7, pretreatment PSA <10) were treated with combined radio-gene therapy. A mean dose of 76 Gy was delivered to the prostate with intensity-modulated radiotherapy. Arm B: high-risk patients (T2b-T3, Gleason score >or=7, pretreatment PSA >or=10) were treated with combined radio-gene therapy and hormonal therapy. Hormonal therapy was comprised of a 4-month leuprolide injection and 2-week use of flutamide. Arm C: Stage D1 (positive pelvic lymph node) patients received the same regimen as Arm B, with the additional 45 Gy to the pelvic lymphatics. Treatment-related toxicity was assessed using Cancer Therapy Evaluation Program common toxicity score and Radiation Therapy Oncology Group (RTOG) toxicity score.

RESULTS

Thirty patients (13 in Arm A, 14 in Arm B, and 3 in Arm C) completed the trial. Median follow-up was 5.5 months. Eleven patients (37%) developed flu-like symptoms (Cancer Therapy Evaluation Program Grade 1) of fatigue and chills/rigors after gene therapy injection but recovered within 24 h. Four patients (13%) and 2 patients (7%) developed Grade 1 and 2 fever, respectively. There was no patient with weight loss. One patient in Arm B developed Grade 3 elevation in liver enzyme, whereas 11 and 2 patients developed Grade 1 and 2 abnormal liver function tests. There was no Grade 2 or above hematologic toxicity. Three patients had transient rise in creatinine. There was no RTOG Grade 3 or above lower gastrointestinal toxicity. Toxicity levels were as follows: 4 patients (13%), Grade 2; 6 patients (20%), Grade 1; and 20 patients (67%), no toxicity. There was 1 patient with RTOG Grade 3 genitourinary toxicity, 12 patients (40%) with Grade 2, 8 patients (27%) with Grade 1, and 9 patients (30%) with no toxicity. No patient dropped out from the trial or had to withhold treatment because of severe toxicity.

CONCLUSIONS

This is the first trial of its kind in the field of prostate cancer that aims to expand the therapeutic index of radiotherapy by combining in situ gene therapy. Initial experience has demonstrated the safety of this approach. There is no added toxicity to each therapy used alone. Long-term follow-up and larger cohort studies are warranted to evaluate long-term toxicity and efficacy.

Important prognostic factors in patients with skull base erosion from nasopharyngeal carcinoma after radiotherapy

PURPOSE

To evaluate the long-term outcome and prognostic factors in patients with skull base erosion from nasopharyngeal carcinoma after initial radiotherapy (RT).

METHODS AND MATERIALS

From January 1985 to December 1986, 100 patients (71 males, 29 females) with a diagnosis of nasopharyngeal carcinoma were found on computed tomography (CT) to have skull base erosion. The mean age was 41 years (range 16-66). Ninety-six patients had World Health Organization type III undifferentiated carcinoma, and 4 had type I. The metastatic workup, including chest radiography, liver ultrasound scanning, and liver function test was negative. All patients underwent external beam RT (EBRT) alone to 66-80 Gy during 6-8 weeks. A daily fraction size of 2 Gy was delivered using 60Co or a linear accelerator. No patient received chemotherapy. All patients were followed at regular intervals after irradiation. The median follow-up was 22.3 months (range 2-174). Survival of the cohort was computed by the Kaplan-Meier method. The potential prognostic factors of survival were examined. Multivariate analyses were performed using the Cox regression model.

RESULTS

The 1, 2, 5, and 10-year overall survival rate for the cohort was 79%, 41%, 27%, and 13%, respectively. However, the subgroup of patients with both anterior cranial nerve (I-VIII) and posterior cranial nerve (IX-XII) involvement had a 5-year survival of only 7.7%. A difference in the time course of local recurrence and distant metastasis was observed. Both local recurrence and distant metastasis often occurred within the first 2 years after RT. However, local relapse continued to occur after 5 years. In contrast, no additional distant metastases were found after 5 years. The causes of death included local recurrence (n = 59), distant metastasis (n = 21), both local recurrence and distant metastasis (n = 1), and unrelated causes (n = 5). After multivariate analysis, complete recovery of cranial nerve involvement, cranial nerve palsy, and headache after irradiation were found to be independent prognostic factors in this cohort.

CONCLUSIONS

We present one of the longest follow-ups of patients with nasopharyngeal carcinoma invading the skull base. Our results demonstrate the importance of cranial nerve involvement, recovery of headache, and cranial nerve palsy. These factors should be carefully evaluated from the history, physical examination, and imaging studies. A subgroup of patients with skull base involvement had long-term survival after RT alone. The findings of this study are important as a yardstick against which more aggressive strategies, such as combined radiochemotherapy and altered fractionation RT can be compared.

Adaptive symmetric mean filter: a new noise-reduction approach based on the slope facet model

Two new noise-reduction algorithms, namely, the adaptive symmetric mean filter (ASMF) and the hybrid filter, are presented in this paper. The idea of the ASMF is to find the largest symmetric region on a slope facet by incorporation of the gradient similarity criterion and the symmetry constraint into region growing. The gradient similarity criterion allows more pixels to be included for a statistically better estimation, whereas the symmetry constraint promises an unbiased estimate if the noise is completely removed. The hybrid filter combines the advantages of the ASMF, the double-window modified-trimmed mean filter, and the adaptive mean filter to optimize noise reduction on the step and the ramp edges. The experimental results have shown the ASMF and the hybrid filter are superior to three conventional filters for the synthetic and the natural images in terms of the root-mean-squared error, the root-mean-squared difference of gradient, and the visual presentation.

Intrahepatic genetic inoculation of hepatitis C virus RNA confers cross-protective immunity

Naturally occurring hepatitis C virus (HCV) infection has long been thought to induce a weak immunity which is insufficient to protect an individual from subsequent infections and has cast doubt on the ability to develop effective vaccines. A series of intrahepatic genetic inoculations (IHGI) with type 1a HCV RNA were performed in a chimpanzee to determine whether a form of genetic immunization might stimulate protective immunity. We demonstrate that the chimpanzee not only developed protective immunity to the homologous type 1a RNA after rechallenge by IHGI but was also protected from chronic HCV infection after sequential rechallenge with 100 50% chimpanzee infectious doses of a heterologous type 1a (H77) and 1b (HC-J4) whole-virus inoculum. These results offer encouragement to pursue the development of HCV vaccines.

The potential use of intensity modulated radiotherapy (IMRT) in women with pectus excavatum desiring breast-conserving therapy

The purpose of this study was to determine if intensity modulated radiation therapy (IMRT) offers a better treatment plan compared to conventional radiotherapy for patients with pectus excavatum desiring breast-conserving therapy and to assess the feasibility of simultaneous modulated accelerated radiation therapy (SMART) boost. A patient with pectus excavatum desired breast-conserving therapy for her early stage breast cancer. She underwent lumpectomy and axillary lymph node dissection followed by chemotherapy. She was then referred for radiotherapy. A breast board (Med-Tec) with aquaplast body cast was used to limit the movement of the patient, chest wall, and breasts before planning a computed tomography (CT) scan. IMRT including dose-volume histogram (DVH) was compared to that of the conventional plan using parallel opposed tangential beams with a 15-degree wedge pair. Forty-five gray was prescribed to the whole breast to each plan, while 50 Gy was prescribed to the tumor bed using IMRT with SMART boost in 25 fractions over 5 weeks. The coverage of the whole breast was adequate for both plans. IMRT allowed a more homogeneous dose distribution within the breast at the desired dose range. With IMRT there is less volume of ipsilateral lung receiving the radiation dose that is above the tolerance threshold of 15 Gy when compared to that of the conventional plan. However, there is more volume of surrounding normal tissues (the heart, spinal cord, and contralateral breast and lung) receiving low-dose irradiation when IMRT was employed. SMART boost was feasible, allowing a mean dose of 57 Gy to be delivered to the tumor bed simultaneously along with the rest of the breast in 5 weeks. IMRT is feasible in treating early breast cancer patients with pectus excavatum by decreasing the ipsilateral lung volume receiving high-dose radiation when compared to the conventional method. SMART boost shortens the overall treatment time that may have potential radiobiological benefit.

Poly(lactide-co-glycolide)/hydroxyapatite delivery of BMP-2-producing cells: a regional gene therapy approach to bone regeneration

Currently, functional treatment of fracture non-unions and bone loss remains a significant challenge in the field of orthopaedic surgery. Tissue engineering of bone has emerged as a new treatment alternative in bone repair and regeneration. Our approach is to combine a polymeric matrix with a cellular vehicle for delivery of bone morphogenetic protein-2 (BMP-2), constructed through retroviral gene transfer. The objective of this study is to develop an osteoinductive, tissue-engineered bone replacement system by culturing BMP-2-producing cells on an osteoconductive, biodegradable, polymeric-ceramic matrix. The hypothesis is that retroviral gene transfer can be used effectively in combination with a biodegradable matrix to promote bone formation. First, we examined the in vitro attachment and growth of transfected BMP-producing cells on a PLAGA-HA scaffold. Second, the bioactivity of the produced BMP in vitro was evaluated using a mouse model. It was found that the polymer-ceramic scaffold supported BMP-2 production, allowing the attachment and growth of retroviral transfected, BMP-2-producing cells. In vivo, the scaffold successfully functioned as a delivery vehicle for bioactive BMP-2, as it induced heterotopic bone formation in a SCID mouse model.

A textural approach based on Gabor functions for texture edge detection in ultrasound images

Edge detection is an important, but difficult, step in quantitative ultrasound (US) image analysis. In this paper, we present a new textural approach for detecting a class of edges in US images; namely, the texture edges with a weak regional mean gray-level difference (RMGD) between adjacent regions. The proposed approach comprises a vision model-based texture edge detector using Gabor functions and a new texture-enhancement scheme. The experimental results on the synthetic edge images have shown that the performances of the four tested textural and nontextural edge detectors are about 20%-95% worse than that of the proposed approach. Moreover, the texture enhancement may improve the performance of the proposed texture edge detector by as much as 40%. The experiments on 20 clinical US images have shown that the proposed approach can find reasonable edges for real objects of interest with the performance of 0.4 +/- 0.08 in terms of the Pratt's figure.

45S5 bioactive glass surface charge variations and the formation of a surface calcium phosphate layer in a solution containing fibronectin

This study investigated the effect of fibronectin adsorption on surface charge variations and calcium phosphate (Ca-P) layer formation kinetics on the surface of 45S5 bioactive glass (BG). We hypothesize that the adsorption of fibronectin on BG changes the surface charge and alters the kinetics of Ca-P layer formation on the glass surface. The charge at a material's surface modulates surface chemistry, protein adsorption, and interactions with bone cells. The zeta potential of BG in a solution containing human plasma fibronectin (TE-FN) was measured as a function of time by particle electrophoresis, and Ca-P layer formation was characterized using SEM, EDXA, and FTIR. Si, Ca, and P solution concentrations also were determined. It was found that the adsorption of fibronectin reduced the initial electronegativity of the BG surface and delayed the formation of both the amorphous and the crystalline Ca-P layers. The delayed formation of these surface layers may be attributed to the competitive binding of Ca2+ ions by the fibronectin molecule. In addition, the formation of an amorphous Ca-P layer correlated with the reversal from a negatively to a positively charged surface, independent of the presence of fibronectin. The addition of a single protein (in this case fibronectin) can significantly alter material surface parameters, such as charge, and subsequently affect the formation of a surface Ca-P layer. Furthermore, the formation of an amorphous Ca-P layer is an important event in the reactions leading to bioactive behavior, and proteins such as FN are actively involved in the transformation of the surface into a Ca-P layer.

45S5 bioactive glass surface charge variations and the formation of a surface calcium phosphate layer in a solution containing fibronectin

This study investigated the effect of fibronectin adsorption on surface charge variations and calcium phosphate (Ca-P) layer formation kinetics on the surface of 45S5 bioactive glass (BG). We hypothesize that the adsorption of fibronectin on BG changes the surface charge and alters the kinetics of Ca-P layer formation on the glass surface. The charge at a material's surface modulates surface chemistry, protein adsorption, and interactions with bone cells. The zeta potential of BG in a solution containing human plasma fibronectin (TE-FN) was measured as a function of time by particle electrophoresis, and Ca-P layer formation was characterized using SEM, EDXA, and FTIR. Si, Ca, and P solution concentrations also were determined. It was found that the adsorption of fibronectin reduced the initial electronegativity of the BG surface and delayed the formation of both the amorphous and the crystalline Ca-P layers. The delayed formation of these surface layers may be attributed to the competitive binding of Ca2+ ions by the fibronectin molecule. In addition, the formation of an amorphous Ca-P layer correlated with the reversal from a negatively to a positively charged surface, independent of the presence of fibronectin. The addition of a single protein (in this case fibronectin) can significantly alter material surface parameters, such as charge, and subsequently affect the formation of a surface Ca-P layer. Furthermore, the formation of an amorphous Ca-P layer is an important event in the reactions leading to bioactive behavior, and proteins such as FN are actively involved in the transformation of the surface into a Ca-P layer.

Intensity-modulated radiation therapy (IMRT) for prostate cancer with the use of a rectal balloon for prostate immobilization: acute toxicity and dose-volume analysis

PURPOSE

To report acute toxicity and to evaluate the relationship between dose-volume effects and acute toxicity in patients with localized prostate cancer, treated with intensity-modulated radiation therapy (IMRT).

METHODS AND MATERIALS

Acute toxicity (both lower gastrointestinal [GI] and genito-urinary [GU]) in 100 patients treated with IMRT definitively to a prescribed dose of 70 Gy were assessed using RTOG scoring criteria. A rectal balloon was used for prostate immobilization. Mean doses to seminal vesicles, prostate, bladder, and rectum were recorded. Average irradiated bladder and rectal volumes above 65, 70, and 75 Gy were assessed. A relationship between dose volume and clinical toxicity was evaluated. All patients completed the full duration of acute toxicity assessment.

RESULTS

Mean doses to the prostate and seminal vesicles were 75.8 and 73.9 Gy. This represents a moderate dose escalation. Acute GI toxicity profile was very favorable. Eleven percent and 6% of the patients had grade 1 and 2 GI toxicity, respectively, while 83% had no GI complaint. For GU complaints, 38% and 35% had grade 1 and 2 toxicity, respectively, while 27% had no complaints. There was no grade 3 or higher acute GI or GU toxicity. Mean doses to the bladder were 22.8, 23.4, and 26.1 Gy for grade 0, 1, and 2 GU toxicity, respectively (p = 0.132). There is no statistically significant relationship between acute GU toxicity and the bladder volume receiving > 65 Gy, > 70 Gy, or > 75 Gy. In evaluating acute GI toxicity, there are very few grade 1 and 2 events. No relationship was found between acute rectal toxicity and mean rectal dose or irradiated rectal volumes receiving more than 65, 70, and 75 Gy.

CONCLUSION

The findings are important with regard to the safety of IMRT, especially in reducing acute GI toxicity. Dose escalation with IMRT using a prostate immobilization technique is feasible. The findings are also important because they contribute to the clinical and dosimetric correlation aspect in the use of IMRT to treat prostate cancer. A larger cohort may be needed to determine if there is a relationship between acute GU toxicity and (a) mean bladder dose and (b) irradiated bladder volume receiving > 65 Gy, > 70 Gy, or > 75 Gy. A larger cohort of patients treated to a higher dose may be needed to show a relationship between dose volume and acute GI toxicity.

Intensity modulated radiation therapy (IMRT) following prostatectomy: more favorable acute genitourinary toxicity profile compared to primary IMRT for prostate cancer

PURPOSE

To report our initial experience on postprostatectomy IMRT (PPI), addressing acute genitourinary (GU) toxicity in comparison to primary IMRT (PI) for prostate cancer.

METHODS AND MATERIALS

From April 1998 to December 1999, 40 postprostatectomy patients were treated with intensity modulated radiation therapy (IMRT) to a median prescribed dose of 64 Gy (mean dose of 69 Gy). The Radiation Therapy Oncology Group (RTOG) scoring system was used to assess acute GU toxicity. Target volume and maximum and mean doses were evaluated. The mean doses to the bladder and irradiated bladder volume receiving >65 Gy were assessed. These were compared to those of 125 patients treated with PI to a prescribed dose of 70 Gy (mean dose of 76 Gy).

RESULTS

The acute GU toxicity profile is more favorable in the PPI group with 82.5% of Grade 0-1 and 17.5% of Grade 2 toxicity compared to 59.2% and 40.8%, respectively, in the PI group (p < 0.001). There was no Grade 3 or higher toxicity in either group. The target volume was larger in the PPI group, while the maximum and mean doses to the target were higher in the PI group. The mean dose delivered to the bladder was higher in the PPI group. The irradiated bladder volume receiving >65 Gy was significantly larger in the PI group (p < 0.001).

CONCLUSIONS

PPI can be delivered with acceptable ute GU toxicity. The larger PPI target volume may be related to the difficulty in delineating prostatic fossa. Despite a larger target volume and a higher mean dose to the bladder, PPI produced a more favorable acute GU toxicity profile. This may be related to a combination of lower mean and maximum doses and smaller bladder volumes receiving >65 Gy in the PPI group, as well as urethral rather than bladder irradiation. The findings have implications in the evaluation of IMRT treatment plan for prostate cancer, whereby the irradiated bladder volumes above 65 Gy may be more meaningful than the mean dose to the bladder. Longer term toxicity results are awaited.

An adaptive snake model for ultrasound image segmentation: modified trimmed mean filter, ramp integration and adaptive weighting parameters

The snake model is a widely-used approach to finding the boundary of the object of interest in an ultrasound image. However, due to the speckles, the weak edges and the tissue-related textures in an ultrasound image, conventional snake models usually cannot obtain the desired boundary satisfactorily. In this paper, we propose a new adaptive snake model for ultrasound image segmentation. The proposed snake model is composed of three major techniques, namely, the modified trimmed mean (MTM) filtering, ramp integration and adaptive weighting parameters. With the advantages of the mean and median filters, the MTM filter is employed to alleviate the speckle interference in the segmentation process. The weak edge enhancement by ramp integration attempts to capture the slowly varying edges, which are hard to capture by conventional snake models. The adaptive weighting parameter allows weighting of each energy term to change adaptively during the deformation process. The proposed snake model has been verified on the phantom and clinical ultrasound images. The experimental results showed that the proposed snake model achieves a reasonable performance with an initial contour placed 10 to 20 pixels away from the desired boundary. The mean minimal distances from the derived boundary to the desired boundary have been shown to be less than 3.5 (for CNR > or = 0.5) and 2.5 pixels, respectively, for the phantom and ultrasound images.

Temporal zeta potential variations of 45S5 bioactive glass immersed in an electrolyte solution

45S5 bioactive glass (BG) is a bioactive material known to bond to bone in vivo through a surface calcium phosphate (Ca-P) layer. The goal of this study was to address the importance of BG surface charge in the bioactive response by examining the relationship between charge variations and the formation of the surface Ca-P layer. The zeta potential of BG in an electrolyte solution (TE) was measured by particle electrophoresis, and the formation of a Ca-P layer was characterized using SEM, EDXA, and FTIR. Si, Ca, and P solution concentrations also were determined. The initial BG surface was negatively charged, and two sign reversals were detected during 3 days of immersion. The first, from negative to positive after 1 day, is attributed to the adsorption of cations at the BG surface, and the second reversal was due to the precipitation of phosphate ions from solution. A strong correlation was found between the formation of a Ca-P layer and BG surface zeta potential variations. The dynamic shift in zeta potential from an initially negative surface to a positively charged surface directly corresponded with the formation of an amorphous Ca-P layer. In addition, when the glass surface matured into a crystalline Ca-P layer, it was associated with a reversal from a positive to a negative surface. Future work will focus on the effects of protein adsorption on BG surface charge and Ca-P layer formation kinetics as well as on cellular response to a changing BG surface.

Temporal zeta potential variations of 45S5 bioactive glass immersed in an electrolyte solution

45S5 bioactive glass (BG) is a bioactive material known to bond to bone in vivo through a surface calcium phosphate (Ca-P) layer. The goal of this study was to address the importance of BG surface charge in the bioactive response by examining the relationship between charge variations and the formation of the surface Ca-P layer. The zeta potential of BG in an electrolyte solution (TE) was measured by particle electrophoresis, and the formation of a Ca-P layer was characterized using SEM, EDXA, and FTIR. Si, Ca, and P solution concentrations also were determined. The initial BG surface was negatively charged, and two sign reversals were detected during 3 days of immersion. The first, from negative to positive after 1 day, is attributed to the adsorption of cations at the BG surface, and the second reversal was due to the precipitation of phosphate ions from solution. A strong correlation was found between the formation of a Ca-P layer and BG surface zeta potential variations. The dynamic shift in zeta potential from an initially negative surface to a positively charged surface directly corresponded with the formation of an amorphous Ca-P layer. In addition, when the glass surface matured into a crystalline Ca-P layer, it was associated with a reversal from a positive to a negative surface. Future work will focus on the effects of protein adsorption on BG surface charge and Ca-P layer formation kinetics as well as on cellular response to a changing BG surface.

An early vision-based snake model for ultrasound image segmentation

Due to the speckles and the ill-defined edges of the object of interest, the classic image-segmentation techniques are usually ineffective in segmenting ultrasound (US) images. In this paper, we present a new algorithm for segmenting general US images that is composed of two major techniques; namely, the early-vision model and the discrete-snake model. By simulating human early vision, the early-vision model can capture both grey-scale and textural edges while the speckle noise is suppressed. By performing deformation only on the peaks of the distance map, the discrete-snake model promises better noise immunity and more accurate convergence. Moreover, the constraint for most conventional snake models that the initial contour needs to be located very close to the actual boundary has been relaxed substantially. The performance of the proposed snake model has been shown to be comparable to manual delineation and superior to that of the gradient vector flow (GVF) snake model.

Differential expression of C-CAM cell adhesion molecule in prostate carcinogenesis in a transgenic mouse model

PURPOSE

The transgenic adenocarcinoma of mouse prostate (TRAMP) model, in which various grades of prostate intraepithelial neoplasia (PIN) and prostate cancer with metastases can be reproducibly generated, is a paradigm for prostate disease progression. We have previously shown that C-CAM, an adhesion molecule, can suppress the growth of prostate cancer. In this report, we describe immunohistochemical characterization of differential expression of C-CAM at various stages of prostate tumorigenesis in the TRAMP model.

MATERIALS AND METHODS

We sampled prostate specimens and periaortic lymph nodes from TRAMP mice. Indirect immunohistochemical staining with a polyclonal anti-C-CAM antibody was performed on the formalin-fixed, paraffin-embedded specimens. After castration at 12 weeks of age, the TRAMP mice developed androgen-independent prostate cancer (AIPC) and lymph node metastasis at 18 to 24 weeks of age. Samples from these castrated mice were also analyzed.

RESULTS

C-CAM protein was expressed in the normal prostate epithelia of non-transgenic and TRAMP mice as well as in low-grade PINs in TRAMP mice. Expression was uniform on the luminal surfaces of these epithelia. C-CAM expression was noticeably reduced and the staining pattern heterogeneous in some high-grade PINs. C-CAM staining was generally absent in prostate cancer and metastatic lymph nodes. Androgen independent prostate cancer and its metastatic tumors generated in castrated TRAMP mice were also C-CAM negative.

CONCLUSIONS

C-CAM expression correlates with the differentiation states of prostate epithelia and is down regulated early in prostate tumorigenesis in the TRAMP model.

AIDS-related Kaposi's sarcoma involving bone and bone marrow

AIDS-related Kaposi's sarcoma rarely involves bone or bone marrow. Computed tomography of the abdomen and pelvis of an AIDS patient with lower back pain and bilateral limb edema revealed multiple lesions involving liver, spleen, and axial skeleton. Bone marrow examination of the involved iliac crest revealed Kaposi's sarcoma. Pathologic diagnosis is important so that appropriate treatment can be prescribed.

Cross-reference weighted least square estimates for positron emission tomography

An efficient new method, termed as the cross-reference weighted least square estimate (WLSE) [CRWLSE], is proposed to integrate the incomplete local smoothness information to improve the reconstruction of positron emission tomography (PET) images in the presence of accidental coincidence events and attenuation. The algebraic reconstruction technique (ART) is applied to this new estimate and the convergence is proved. This numerical technique is based on row operations. The computational complexity is only linear in the sizes of pixels and detector tubes. Hence, it is efficient in storage and computation for a large and sparse system. Moreover, the easy incorporation of range limits and spatially variant penalty will not deprive the efficiency. All this makes the new method practically applicable. An automatically data-driven selection method for this new estimate based on the generalized cross validation is also studied. The Monte Carlo studies demonstrate the advantages of this new method.

The Baylor College of Medicine experience with gold seed implantation

Advances in imaging technology and implant technique have led to the resurgent interest and practice of brachytherapy for the treatment of prostate cancer. Brachytherapy is a form of radiation treatment in which radioactive sources are placed directly into the tumor; it offers the advantage of maximizing the radiation dose delivered to the tumor while sparing the adjacent normal tissue. Permanent implants have become an important component of radiation delivery. Interstitial gold radioisotope (Au-198) implants for prostate cancer were introduced at Baylor College of Medicine in 1965. The rationale for using Au-198, instead of the two most commonly used radioisotopes, Palladium-103 (Pd-103) and Iodine-125 (I-125), is discussed, and the Baylor implant technique is compared to that used in other centers. Retrospective review divides the patient population into pre-ultrasound versus post-ultrasound eras. Dosimetric calculation and disease control with the Au-198 seed implant for prostatic cancer are reviewed for the two different eras; toxicity is evaluated in the post-ultrasound era only. In the pre-ultrasound era, 510 patients were treated with pelvic lymph node sampling and gold seed insertion of the prostate followed by external beam radiation. In the post-ultrasound era, 54 patients were treated definitively with ultrasound-guided transperineal Au-198 implant followed by external beam irradiation. A small group of 30 patients in the post-ultrasound era were evaluated for the efficacy of Au-198 re-implantation for locally recurrent disease.