Natural Product Bis-Intercalator Depsipeptides as a New Class of Payloads for Antibody-Drug Conjugates.

A potent class of DNA-damaging agents, natural product bis-intercalator depsipeptides (NPBIDs), was evaluated as ultrapotent payloads for use in antibody-drug conjugates (ADCs). Detailed investigation of potency (both in cells and via biophysical characterization of DNA binding), chemical tractability, and in vitro and in vivo stability of the compounds in this class eliminated a number of potential candidates, greatly reducing the complexity and resources required for conjugate preparation and evaluation. This effort yielded a potent, stable, and efficacious ADC, PF-06888667, consisting of the bis-intercalator, SW-163D, conjugated via an N-acetyl-lysine-valine-citrulline- p-aminobenzyl alcohol- N, N-dimethylethylenediamine (AcLysValCit-PABC-DMAE) linker to an engineered variant of the anti-Her2 mAb, trastuzumab, catalyzed by transglutaminase.

The lead optimization of the polyamine conjugate of flavonoid with a naphthalene motif: Synthesis and biological evaluation.

Polyamine conjugated flavonoid with a naphthalene moiety (ZYY14) displayed excellent therapeutic activity against hepatocellular carcinoma. In this study, three different series of novel flavonoid-polyamine conjugates were designed and screened against tumor cell lines. The structure-activity relationship study demonstrated the importance of the naphthalene moiety (as the B-ring), the basic side chains in the A-ring, and the methoxy group linked to the C-ring. The optimized compound 9b displayed better antitumor potency in vitro and in vivo than the lead compound ZYY14. Fluorescent assays revealed that 9b could enter cancer cells via polyamine transporter (PAT) and locate in mitochondria and endoplasmic reticulum. Compound 9b and ZYY14 demonstrated similar apoptotic mechanism in the cytotoxicity studies and stimulated the expression of apoptosis-related proteins, such as p-p38, p-JNK, p53 and Bax. In addition, 9b can initiate autophagy which inhibited the occurrence of apoptosis. Thus, 9b can be used as a valuable lead for the future development of antitumor agents.

Inhibition of miR-128-3p by Tongxinluo Protects Human Cardiomyocytes from Ischemia/reperfusion Injury via Upregulation of p70s6k1/p-p70s6k1.

Background and Aims: Tongxinluo (TXL) is a multifunctional traditional Chinese medicine that has been widely used to treat cardiovascular and cerebrovascular diseases. However, no studies have explored whether TXL can protect human cardiomyocytes (HCMs) from ischemia/reperfusion (I/R) injury. Reperfusion Injury Salvage Kinase (RISK) pathway activation was previously demonstrated to protect the hearts against I/R injury and it is generally activated via Akt or (and) Erk 1/2, and their common downstream protein, ribosomal protein S6 kinase (p70s6k). In addition, prior studies proved that TXL treatment of cells promoted secretion of VEGF, which could be stimulated by the increased phosphorylation of one p70s6k subtype, p70s6k1. Consequently, we hypothesized TXL could protect HCMs from I/R injury by activating p70s6k1 and investigated the underlying mechanism. Methods and Results: HCMs were exposed to hypoxia (18 h) and reoxygenation (2 h) (H/R), with or without TXL pretreatment. H/R reduced mitochondrial membrane potential, increased bax/bcl-2 ratios and cytochrome C levels and induced HCM apoptosis. TXL preconditioning reversed these H/R-induced changes in a dose-dependent manner and was most effective at 400 µg/mL. The anti-apoptotic effect of TXL was abrogated by rapamycin, an inhibitor of p70s6k. However, inhibitors of Erk1/2 (U0126) or Akt (LY294002) failed to inhibit the protective effect of TXL. TXL increased p70s6k1 expression and, thus, enhanced its phosphorylation. Furthermore, transfection of cardiomyocytes with siRNA to p70s6k1 abolished the protective effects of TXL. Among the micro-RNAs (miR-145-5p, miR-128-3p and miR-497-5p) previously reported to target p70s6k1, TXL downregulated miR-128-3p in HCMs during H/R, but had no effects on miR-145-5p and miR-497-5p. An in vivo study confirmed the role of the p70s6k1 pathway in the infarct-sparing effect of TXL, demonstrating that TXL decreased miR-128-3p levels in the rat myocardium during I/R. Transfection of HCMs with a hsa-miR-128-3p mimic eliminated the protective effects of TXL. Conclusions: The miR-128-3p/p70s6k1 signaling pathway is involved in protection by TXL against HCM apoptosis during H/R. Overexpression of p70s6k1 is, therefore, a potential new strategy for alleviating myocardial reperfusion injury.

Design, synthesis and evaluation of novel 7-aminoalkyl-substituted flavonoid derivatives with improved cholinesterase inhibitory activities.

A novel series of 7-aminoalkyl-substituted flavonoid derivatives 5a-5r were designed, synthesized and evaluated as potential cholinesterase inhibitors. The results showed that most of the synthesized compounds exhibited potent acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitory activities at the micromolar range. Compound 2-(naphthalen-1-yl)-7-(8-(pyrrolidin-1-yl)octyloxy)-4H-chromen-4-one (5q) showed the best inhibitory activity (IC50, 0.64µM for AChE and 0.42µM for BChE) which were better than our previously reported compounds and the commercially available cholinergic agent Rivastigmine. The results from a Lineweaver-Burk plot indicated a mixed-type inhibition for compound 5q with AChE and BChE. Furthermore, molecular modeling study showed that 5q targeted both the catalytic active site (CAS) and the peripheral anionic site (PAS) of AChE. Besides, these compounds (5a-5r) did not affect PC12 and HepG2 cell viability at the concentration of 10µM. Consequently, these flavonoid derivatives should be further investigated as multipotent agents for the treatment of Alzheimer's disease.

Biosynthetic engineering and fermentation media development leads to gram-scale production of spliceostatin natural products in Burkholderia sp.

A key challenge in natural products drug discovery is compound supply. Hundreds of grams of purified material are needed to advance a natural product lead through preclinical development. Spliceostatins are polyketide-nonribosomal peptide natural products that bind to the spliceosome, an emerging target in cancer therapy. The wild-type bacterium Burkholderia sp. FERM BP-3421 produces a suite of spliceostatin congeners with varying biological activities and physiological stabilities. Hemiketal compounds such as FR901464 were the first to be described. Due to its improved properties, we were particularly interested in a carboxylic acid precursor analog that was first reported from Burkholderia sp. MSMB 43 and termed thailanstatin A. Inactivation of the iron/α-ketoglutarate-dependent dioxygenase gene fr9P had been shown to block hemiketal biosynthesis. However, a 4-deoxy congener of thailanstatin A was the main product seen in the dioxygenase mutant. We show here that expression of the cytochrome P450 gene fr9R is a metabolic bottle neck, as use of an l-arabinose inducible system led to nearly complete conversion of the 4-deoxy analog to the target molecule. By integrating fermentation media development approaches with biosynthetic engineering, we were able to improve production titers of the target compound >40-fold, going from the starting ~60 mg/L to 2.5 g/L, and to achieve what is predominantly a single component production profile. These improvements were instrumental in enabling preclinical development of spliceostatin analogs as chemotherapy.

[Research on Collateral-unblocking Medicines for Cardiovascular Diseases under the Guidance of Vessels Collateral Theory].

OBJECTIVE: "Vessels Collateral Theory", as the inherit and development of "blood vessels" in Huangdi Neijing, is a systematic system by integrating severe vascular diseases. In this article, by taking cardiovascular diseases (CVD) as a cut-in point, roles of "minute collateral-microvascular" lesions in the occurrence and development of CVD were further explored. The interventional effect of collateral-unblocking medicines under the guidance of Vessels Collateral Theory was also in-depth explored, hoping to leading Chinese medical prevention and treatment of CVD.

[Monitoring on spatial and temporal changes of snow cover in the Heilongjiang Basin based on remote sensing].

This paper extracted and verified the snow cover extent in Heilongjiang Basin from 2003 to 2012 based on MODIS Aqua and Terra data, and the seasonal and interannual variations of snow cover extent were analyzed. The result showed that the double-star composite data reduced the effects of clouds and the overall accuracy was more than 91%, which could meet the research requirements. There existed significant seasonal variation of snow cover extent. The snow cover area was almost zero in July and August while in January it expanded to the maximum, which accounted for more than 80% of the basin. According to the analysis on the interannual variability of snow cover, the maximum winter snow cover areas in 2003-2004 and 2009-2010 (>180 x 10(4) km2) were higher than that of 2011 (150 x 10(4) km2). Meanwhile, there were certain correlations between the interannual fluctuations of snow cover and the changes of average annual temperature and precipitation. The year with the low snow cover was corresponding to less annual rainfall and higher average temperature, and vice versa. The spring snow cover showed a decreasing trend from 2003 to 2012, which was closely linked with decreasing precipitation and increasing temperature.

18F-FDG PET and combined 18F-FDG-contrast CT parameters as predictors of tumor control for hepatocellular carcinoma after stereotactic ablative radiotherapy.

UNLABELLED: The application of stereotactic ablative radiotherapy (SABR) to hepatocellular carcinoma (HCC) is emerging. To identify pretreatment prognostic indicators is crucial for patient selection and optimal individual therapy. The aim of this study was to determine whether (18)F-FDG PET and a combined (18)F-FDG-contrast CT parameter could be useful tools to predict tumor control for patients with HCC treated by SABR. METHODS: We retrospectively identified 31 patients (41 tumors) who underwent (18)F-FDG PET before SABR between November 2007 and September 2011. (18)F-FDG PET parameters were collected as prognostic indicators, including visual PET scale (+/-), maximal standardized uptake value (SUV) of the tumor (T SUV max), ratio of T SUV max to maximal normal-liver SUV, ratio of T SUV max to mean normal-liver SUV, and score combining tumor volume and T SUV max (CT/(18)F-FDG PET score). They underwent SABR with a median dose of 42 Gy (ranging from 30 to 50 Gy) in 4-5 fractions. (18)F-FDG PET parameters and clinical factors were tested as predictors of tumor control and patient survival. RESULTS: The median follow-up time was 18 mo. Among the parameters examined, T SUV max and CT/(18)F-FDG PET score were significantly correlated with tumor control. T SUV max with a cutoff value of 3.2 was the most significant prognostic indicator. The 4-y control rate was 86.2% in tumors with a T SUV max of 3.2 or less but only 37.5% in those with a T SUV max of more than 3.2 (adjusted hazard ratio, 9.40; 95% confidence interval, 1.18-74.76; P = 0.034). CT/(18)F-FDG PET score (≤ 4 vs. >4) was also a significant predictor of tumor control after SABR. Tumors with a CT/(18)F-FDG PET score of more than 4 had a 5.23-fold risk of tumor failure. After adjustment for factors of sex, American Joint Committee on Cancer stage, Cancer of the Liver Italian Program score, and Child-Pugh classification, tumors with a score of more than 4 had a 4.96-fold risk of failure after SABR, compared with tumors with a score of 4 or less. For overall survival, none was statistically significant. CONCLUSION: The use of (18)F FDG PET to predict tumor control is feasible. T SUV max with a cutoff value of 3.2 is the best prognostic indicator. We suggest that (18)F-FDG PET may be a reference for prognostic prediction, patient selection, and radiation dose adjustment for HCC patients treated with SABR.

Stereotactic body radiation therapy in recurrent hepatocellular carcinoma.

PURPOSE: To examine the safety and efficacy of Cyberknife stereotactic body radiation therapy (SBRT) and its effect on survival in patients of recurrent hepatocellular carcinoma (HCC). METHODS AND MATERIALS: This was a matched-pair study. From January 2008 to December 2009, 36 patients with 42 lesions of unresectable recurrent HCC were treated with SBRT. The median prescribed dose was 37 Gy (range, 25 to 48 Gy) in 4-5 fractions over 4-5 consecutive working days. Another 138 patients in the historical control group given other or no treatments were selected for matched analyses. RESULTS: The median follow-up time was 14 months for all patients and 20 months for those alive. The 1- and 2-year in-field failure-free rates were 87.6% and 75.1%, respectively. Out-field intrahepatic recurrence was the main cause of failure. The 2-year overall survival (OS) rate was 64.0%, and median time to progression was 8.0 months. In the multivariable analysis of all 174 patients, SBRT (yes vs. no), tumor size (≤4 cm vs. >4 cm), recurrent stage (stage IIIB/IV vs. I) and Child-Pugh classification (A vs. B/C) were independent prognostic factors for OS. Matched-pair analysis revealed that patients undergoing SBRT had better OS (2-year OS of 72.6% vs. 42.1%, respectively, p = 0.013). Acute toxicities were mild and tolerable. CONCLUSION: SBRT is a safe and efficacious modality and appears to be well-tolerated at the dose fractionation we have used, and its use correlates with improved survival in this cohort of patients with recurrent unresectable HCC. Out-field recurrence is the major cause of failure. Further studies of combinations of SBRT and systemic therapies may be reasonable.

[Effects of tongxinluo on angiogenesis and the volume of blood perfusion in ischemic stroke rats].

OBJECTIVE: To observe the effects of Tongxinluo (TXL) on angiogenesis and the volume of blood perfusion in ischemic stroke rats. METHODS: The model of middle cerebral artery occlusion (MCAO) was established using craniotomy ligation of the middle cerebral artery on one side. After screening, the male SD rats were randomly divided into the sham-operation group, the model group, the large dose TXL group, the middle dose TXL group, the low dose TXL group, and the Nimodipine group. The expression of microvascular density (MVD, CD31) of the MCAO rats was detected using immunohistochemical assay after 14 days of medication. The microvascular morphology and the volume of blood perfusion in the brain tissue were observed under laser scanning confocal microscope (LSCM). RESULTS: The positive CD31 expression was intense with significant coloring in the large dose TXL group, the middle dose TXL group, and the Nimodipine group, better than that of the model group. The blood perfusion volume in the ischemic brain cortex could be promoted in the large dose TXL group, the middle dose TXL group, and the Nimodipine group (P<0.01, P<0.05). The optimal effects were shown in the large dose TXL group (P<0.01). CONCLUSION: TXL significantly increased the MVD of the ischemic brain tissue, promoted the post-ischemic angiogenesis, and increased the volume of blood perfusion of ischemic brain tissue, playing certain blood flow compensatory roles.

[Effects of fatigue and restraint stress on the expression of carnitine palmitoyltransferase-I and 5-hydroxytryptamine receptors in aorta of rats].

OBJECTIVE: To investigate the effect of fatigue and restraint stress on the expressions of CPT (carnitine palmitoyltransferase)-I, PPAR (peroxisome proliferator-activated receptor) δ, 5-HT (hydroxytryptamine) 1D and 5-HT2A receptors in aorta of rats. METHODS: A total of 45 healthy male Wistar rats were randomly divided into control group, excessive fatigue group and restraint stress group (n = 15 each). The general condition, morphological changes of aortic endothelium cell and the blood levels of ET-1 (endothelin) and NO (nitric oxide) were observed. The real-time reverse transcription PCR (polymerase chain reaction) and Western blot were used to detect the gene and protein expressions of CPT-I, PPAR δ, 5-HT1D and 5-HT2A receptors in aorta. RESULTS: Compared with control group, the structural damages of endothelial cell were induced by excessive fatigue and restraint stress. The plasma levels of ET-1 increased [(124 ± 18) ng/L vs (161 ± 18) ng/L, (154 ± 17) ng/L] (P < 0.01, P < 0.05) while the serum levels of NO decreased [(63 ± 16) µmol/L vs (39 ± 8) µmol/L, (41 ± 7) µmol/L] (P < 0.05); the mRNA expressions of CPT-Iand PPARδ decreased in excessive fatigue rats, [(1.23 ± 0.21) vs (0.42 ± 0.05)], [(1.09 ± 0.10) vs (0.25 ± 0.07)] (P < 0.01); the protein expressions of CPT-Iand PPARδ decreased in excessive fatigue rats, [(1.32 ± 0.07) vs (0.83 ± 0.04)], [(1.41 ± 0.05) vs. (0.75 ± 0.06)]; the mRNA and protein expressions of 5-HT1D receptor decreased in excessive fatigue rats and restraint stress rats, [(1.10 ± 0.15) vs (0.46 ± 0.13), (0.45 ± 0.02)], [(1.19 ± 0.05) vs (0.71 ± 0.06), (0.70 ± 0.05)] (P < 0.01); the mRNA and protein expressions of 5-HT2A receptor increased in excessive fatigue rats and restraint stress rats, [(0.99 ± 0.08) vs (6.73 ± 0.46), (7.01 ± 1.56)], [(0.64 ± 0.03) vs (0.79 ± 0.05), (0.82 ± 0.03)] (P < 0.01). CONCLUSION: Excessive fatigue and restraint stress can injure the structure and function of endothelial cell. The changes in energy of abnormal carnitine metabolism and 5-HT receptors may play important roles.

Intensity modulated radiotherapy with concurrent chemotherapy for larynx preservation of advanced resectable hypopharyngeal cancer.

BACKGROUND: To analyze the rate of larynx preservation in patients of locally advanced hypopharyngeal cancer treated with intensity modulated radiotherapy (IMRT) plus concurrent chemotherapy, and compare the results with patients treated with primary surgery. METHODS: Between January 2003 and November 2007, 14 patients were treated with primary surgery and 33 patients were treated with concurrent chemoradiotherapy (CCRT) using IMRT technique. Survival rate, larynx preservation rate were calculated with the Kaplan-Meier method. Multivariate analysis was conducted for significant prognostic factors with Cox-regression method. RESULTS: The median follow-up was 19.4 months for all patients, and 25.8 months for those alive. The 5-year overall survival rate was 33% and 44% for primary surgery and definitive CCRT, respectively (p = 0.788). The 5-year functional larynx-preservation survival after IMRT was 40%. Acute toxicities were common, but usually tolerable. The rates of treatment-related mucositis (> or = grade 2) and pharyngitis (> or = grade 3) were higher in the CCRT group. For multivariate analysis, treatment response and cricoid cartilage invasion strongly correlated with survival. CONCLUSIONS: IMRT plus concurrent chemotherapy may preserve the larynx without compromising survival. Further studies on new effective therapeutic agents are essential.

Successful treatment of metastatic brain tumor by CyberKnife: a case report.

Stereotactic radiosurgery plays an important role in management of metastatic brain tumors, especially when the tumor has recurred after treatment with previous whole brain radiotherapy. Most metastatic brain tumors less than 1 cm(3) show a complete response after stereotactic radio-surgery. However, there are few reports of a dramatic change in the complete response of large metastatic brain tumors. Here, we report a case of adenocarcinoma of lung that had metastasized to the brain. Because the recurrence of the metastatic brain tumor measured approximately 3 cm in diameter, the tumor was previously treated with two prior craniotomies followed by whole brain radiation to the resection cavity. The tumor subsequently recurred and was treated with stereotactic radiosurgery (CyberKnife). A dramatic response was noted 3 months after radiosurgery with complete disappearance of the recurrent tumor.

Peritumoral edema after stereotactic radiosurgery for meningioma.

Peritumoral edema induced by radiosurgery after the treatment of intracranial meningioma has been reported and its mechanism remains unclear. A 65-year-old woman presented with a history of intermittent dizziness. A CT scan and MRI of the brain revealed an extra-axial space-occupying lesion in the left frontal region. She was treated by stereotactic radiosurgery (SRS). Seven months later, the patient began experiencing general weakness and drowsiness. She developed peritumoral edema around the left frontal tumor. Similarly, a 55-year-old woman complained of unstable gait and dizziness 1 month prior to admission. A CT scan and MRI of the brain revealed an extra-axial space-occupying lesion in the right posterior temporal region. Six months after SRS, this patient experienced deteriorated consciousness and general weakness. Peritumoral edema in the right temporal region was noted. We report these two patients, discuss possible causes and review the relevant literature.

Liquid perfluorochemical inhibits inducible nitric oxide synthase expression and nitric oxide formation in lipopolysaccharide-treated RAW 264.7 macrophages.

Partial liquid ventilation with various types of perfluorocarbon (PFC) has been shown to be beneficial in treating acute lung injury, a clinical outcome that may involve the anti-inflammatory activity of PFC. FC-77 is a type of PFC with relatively higher vapor pressure and evaporative loss than other PFCs during partial liquid ventilation. Overproduction of nitric oxide (NO) by inducible nitric oxide synthase (iNOS) has been proposed to play a crucial role in the pathogenesis of inflammatory diseases. However, whether the iNOS/NO pathway is affected by FC-77 is unknown. Thus, the aim of this study was to investigate whether FC-77 inhibits iNOS expression and NO production in lipopolysaccharide (LPS)-treated RAW 264.7 macrophages. We found that treatment with FC-77 significantly attenuated LPS-induced iNOS expression/activity and production of NO and reactive oxygen species (ROS). FC-77 also attenuated LPS-induced pro-inflammatory cytokine formation, but enhanced interleukin-10 production. Furthermore, the LPS-induced degradation of cytosolic IkappaB-alpha and activation of nuclear transcription factor-kappaB (NF-kappaB) were also inhibited by FC-77. In conclusion, the present study is the first to demonstrate that FC-77 decreases LPS-induced NO production in macrophages, which may be associated with the suppression of pro-inflammatory cytokines, and ROS production, as well as NF-kappaB activation. These results also provide a novel explanation for its anti-inflammatory activity.

The lecanindoles, nonsteroidal progestins from the terrestrial fungus Verticillium lecanii 6144.

Four new indolosesquiterpenes, lecanindoles A-D (1-4), were isolated from fermentations of the terrestrial fungus Verticillium lecanii 6144. The structures of compounds 1-4 were elucidated from analysis of spectroscopic data. Compound 2 was reduced to give 4 and its isomer 5. Compound 4 was found to be a potent and selective progesterone receptor agonist with an EC50 of 1.1 +/- 0.4 nM in a cell-based luciferase reporter assay.

Production of fungal antibiotics using polymeric solid supports in solid-state and liquid fermentation.

The use of inert absorbent polymeric supports for cellular attachment in solid-state fungal fermentation influenced growth, morphology, and production of bioactive secondary metabolites. Two filamentous fungi exemplified the utility of this approach to facilitate the discovery of new antimicrobial compounds. Cylindrocarpon sp. LL-Cyan426 produced pyrrocidines A and B and Acremonium sp. LL-Cyan416 produced acremonidins A-E when grown on agar bearing moist polyester-cellulose paper and generated distinctly different metabolite profiles than the conventional shaken or stationary liquid fermentations. Differences were also apparent when tenfold concentrated methanol extracts from these fermentations were tested against antibiotic-susceptible and antibiotic-resistant Gram-positive bacteria, and zones of inhibition were compared. Shaken broth cultures of Acremonium sp. or Cylindrocarpon sp. showed complex HPLC patterns, lower levels of target compounds, and high levels of unwanted compounds and medium components, while agar/solid support cultures showed significantly increased yields of pyrrocidines A and B and acremonidins A-E, respectively. This method, mixed-phase fermentation (fermentation with an inert solid support bearing liquid medium), exploited the increase in surface area available for fungal growth on the supports and the tendency of some microorganisms to adhere to solid surfaces, possibly mimicking their natural growth habits. The production of dimeric anthraquinones by Penicillium sp. LL-WF159 was investigated in liquid fermentation using various inert polymeric immobilization supports composed of polypropylene, polypropylene cellulose, polyester-cellulose, or polyurethane. This culture produced rugulosin, skyrin, flavomannin, and a new bisanthracene, WF159-A, after fermentation in the presence and absence of polymeric supports for mycelial attachment. The physical nature of the different support systems influenced culture morphology and relative metabolite yields, as determined by HPLC analysis and measurement of antimicrobial activity. The application of such immobilized-cell fermentation methods under solid and liquid conditions facilitated the discovery of new antibiotic compounds, and offers new approaches to fungal fermentation for natural product discovery.

Squamous cell carcinoma of the buccal mucosa: an aggressive cancer requiring multimodality treatment.

BACKGROUND: In our clinical practice, we have observed a high incidence of locoregional failure in squamous cell carcinoma (SCC) of the buccal mucosa. We analyze our treatment results of this cancer and compare these results with those in the literature. We intend to define the pattern and incidence of failure of buccal cancer and provide information for the design of a better multimodality treatment. METHODS: During the period from 1983 through 2003, 121 previously untreated patients with M0 stage SCC of the buccal mucosa were treated with a curative intent at our hospital. Twenty-seven patients received surgery alone, 36 had radiotherapy alone, and 58 underwent surgery plus postoperative radiotherapy. RESULTS: The 5-year locoregional control, overall survival, and cause-specific survival rates for all patients were 36.3%, 34.3%, and 36.9%, respectively. The locoregional recurrence rate was 57% for all patients, with 80% occurring in the primary site alone. Patients with T1-2N0 disease who received surgery alone still had a high local recurrence incidence of 41%. For patients with locally advanced disease, surgery plus postoperative radiotherapy achieved better overall survival and locoregional control rates than surgery alone or radiotherapy alone. T classification was the only prognostic factor affecting locoregional control and survival in the surgery alone group, whereas N classification and skin invasion predicted a poorer survival for the surgery plus postoperative radiotherapy group. CONCLUSIONS: SCC of the buccal mucosa is an aggressive cancer with a high locoregional failure rate even in patients with T1-2N0 disease. Possible reasons include inadequate treatment and an intrinsically aggressive nature. Postoperative radiotherapy has resulted in a better locoregional control rate for patients with T3-4 or N+ disease and should also be considered for patients with T1-2N0 disease for whom adjuvant therapy after radical surgery currently is not recommended by most guidelines.

Microsatellite diversity within Oryza sativa with emphasis on indica-japonica divergence.

The molecular evolution of cultivated rice Oryza sativa L. has long been a subject of rice evolutionists. To investigate genetic diversity within and differentiation between the indica and japonica subspecies, 22 accessions of indica and 35 of japonica rice were examined by five microsatellite loci from each chromosome totalling 60 loci. Mean gene diversity value in the indica rice (H=0.678) was 1.18 times larger than in the japonica rice (H=0.574). Taking the sampling effect into consideration, average allele number in the indica rice was 1.40 times higher than that in the japonica rice (14.6 vs 10.4 per variety). Chromosome-based comparisons revealed that nine chromosomes (1, 2, 3, 4, 5, 8, 9, 10 and 11) harboured higher levels of genetic diversity within the indica rice than the japonica rice. An overall estimate of F(ST) was 0.084-0.158, indicating that the differentiation is moderate and 8.4-15.8% of the total genetic variation resided between the indica and japonica groups. Our chromosome-based comparisons further suggested that the extent of the indica-japonica differentiation varied substantially, ranging from 7.62% in chromosome 3 to 28.72% in chromosome 1. Cluster analyses found that most varieties formed merely two clusters for the indica and japonica varieties, in which two japonica varieties and five indica varieties were included in the counterpart clusters, respectively. The 12 chromosome-based trees further showed that 57 rice varieties cannot be clearly clustered together into either the indica or japonica groups, but displayed relatively different clustering patterns. The results suggest that the process of indica japonica differentiation may have proceeded through an extensive contribution by the alleles of the majority in the rice genome.

Parotid gland-sparing 3-dimensional conformal radiotherapy results in less severe dry mouth in nasopharyngeal cancer patients: a dosimetric and clinical comparison with conventional radiotherapy.

BACKGROUND AND PURPOSE: This study examined the efficacy of parotid gland sparing of three-dimensional conformal radiotherapy (3DCRT) compared with conventional radiotherapy for NPC patients. Both the dose given to the parotids and clinical assessment of dry mouth were conducted. MATERIALS AND METHODS: Dry mouth was assessed for 108 patients treated with conventional technique and 72 treated with 3DCRT. Dose analysis was performed in 48 patients of the 3DCRT group. A dose of 70 Gy was given to the midplane in conventional radiotherapy and to 90% isodose volume in 3DCRT. Prognostic factors affecting the severity of dry mouth were analyzed using Generalized Estimating Equation (GEE). RESULTS: In the 3DCRT group about 50% of the patients' parotid glands received less than 25 Gy. Parallel analysis of dry mouth shows a significant decrease in the incidence of severe xerostomia after 3DCRT. The proportion of patients without dry mouth was also significantly higher in the 3DCRT group than the conventional group at 1-3 years after completion of radiotherapy. Although 3DCRT delivered a higher dose to the tumor, it spared the parotid gland significantly better than the conventional treatment. Late toxicities were mostly similar between the 2 groups while local control in T4 patients and survival were improved for 3DCRT. CONCLUSION: Dosimetrically and clinically 3DCRT is better than conventional technique regarding parotid gland protection.