Ecdysteroids and juvenile hormones of whiteflies, important insect vectors for plant viruses

Ecdysteroids and juvenile hormones (JHs) regulate many physiological events throughout the insect life cycle, including molting, metamorphosis, ecdysis, diapause, reproduction, and behavior. Fluctuation of whitefly ecdysteroid levels and the identity of the whitefly molting hormone (20-hydroxyecdysone) have only been reported within the last few years. An ecdysteroid commitment peak that is associated with the reprogramming of tissues for a metamorphic molt in many holometabolous and some hemimetabolous insect species was not observed in last nymphal instars of either the sweet potato whitefly, Bemisia tabaci (Biotype B), or the greenhouse whitefly, Trialeurodes vaporariorum. Ecdysteroids reach peak levels 1-2 days prior to the initiation of the nymphal-adult metamorphic molt. Adult eye and wing differentiation which signal the onset of this molt begin earlier in 4th instar T. vaporariorum (Stages 4 and 5, respectively) than in B. tabaci (Stage 6), and the premolt peak is 3-4 times greater in B. tabaci ( approximately 400 fg/microg protein) than in T. vaporariorum ( approximately 120 fg/microg protein). The JH of B. tabaci nymphs and eggs was found to be JH III, supporting the view that JHs I and II are, with rare exception, only present in lepidopteran insects. In B. tabaci eggs, JH levels were approximately 10 times greater on day 2/3 (0.44 fg/egg or 0.54 ng/g) than on day 5 (0.04 fg/egg or 0.054 ng/g) post-oviposition. Approximately, 1.4 fg/2nd-3rd instar nymph (0.36 ng/g) was detected. It is probable that the relatively high level of JH in day 2/3 eggs is associated with the differentiation of various whitefly tissues during embryonic development.     

On the HIV Incubation Distribution Under AZT Treatment

Assuming some general models for the HIV epidemic, in this paper I derive the HIV incubation distributions under AZT treatment. It is shown that under some conditions, these probability distributions are mixtures of some generalized Gamma distributions and products of generalized Gamma distributions.     

Effectiveness of population-based colorectal cancer screening programme in down-staging

BackgroundThis is the first evaluation study to assess the demographic characteristics of the colorectal cancer (CRC) cases detected in the prevalent round of the population-based Colorectal Cancer Screening Programme (CRCSP) in Hong Kong and to explore the effectiveness of the programme on the stage distribution of CRC.MethodsThis study covered the period between 28 September 2016 and 31 December 2018. Information on CRC diagnosis, age and stage at diagnosis were retrieved and reviewed by the Hong Kong Cancer Registry (HKCaR). The CRC detection rate among CRCSP-screened participants and incidence rate among the Hong Kong general population were calculated respectively. The odds ratio (OR) was calculated to measure the strength of association and quantify the effect of CRCSP on stage shift between CRCSP-detected CRC cases and an age-matched cohort of CRC cases diagnosed outside the programme.ResultsThe CRC detection rate among participants of the CRCSP during the study period was 736.0/100,000, whereas the overall CRC incidence rate among general population of similar age groups was 393.7/100,000. For all ages and both sexes, the OR of stage I CRCSP-detected CRC compared to the CRC from the age-matched cohort was 3.91 (95%CI=3.41–4.48) and the OR dropped to 0.54 (95%CI=0.41–0.70) at stage IV. Meanwhile, the overall OR of CRCSP-detected CRC compared to CRC from the age-matched cohort dropped from 2.24 (95%CI=1.97–2.56) to 1.62 (95%CI=1.40–1.87) with increasing age.ConclusionThe present study has demonstrated the initial impact of the CRCSP on shifting the stage at diagnosis towards earlier stage. The benefit of stage-shift was similar for all ages from 60 to 77 in both sexes and seems to increase with younger age. Given the stage-dependent survival outcomes, this stage-shift could lead to a reduction in CRC-associated mortality in Hong Kong in future.     

Impact of 68Ga-PSMA PET/CT in the treatment of prostate cancer: Initial experience in Spain

AimTo evaluate whether positron-emission tomography/computed tomography with ⁶⁸Ga-PSMA (⁶⁸Ga-PSMA PET/CT) influences the therapeutic management of patients with primary or recurrent prostate cancer (PCa).BackgroundAlthough ⁶⁸Ga-PSMA PET/CT is one of the best options for staging or restaging patients with PCa, its availability is still very limited in Spain. The present study reports the results of the first group of patients in Spain who underwent ⁶⁸Ga-PSMA PET/CT imaging.Materials and methodsAll patients (n = 27) with a histological diagnosis of PCa who underwent ⁶⁸Ga-PSMA PET/CT prior to the definitive treatment decision at the only centre with this technology in Spain during 2017–2018 were included. Two nuclear medicine physicians and a radiologist reviewed the imaging studies. The clinical impact was assessed from a theoretical perspective, based on the treatment that would have been applied if no data from the ⁶⁸Ga-PSMA PET/CT were available.ResultsMost patients (n = 26; 96%) had persistent disease or biochemical recurrence after radical prostatectomy, radiotherapy, or combined treatment. One patient underwent ⁶⁸Ga-PSMA PET/CT imaging to stage high-risk PCa. Overall, ⁶⁸Ga-PSMA PET/CT was positive in 19 patients (70.4%). In 68.75% of these patients, none of the other imaging tests—MRI, CT, or bone scans—performed prior to the ⁶⁸Ga-PSMA PET/CT were able to detect the presence of cancerous lesions. Overall, the findings of the ⁶⁸Ga-PSMA PET/CT led to a modification of the therapeutic approach in 62.96% of the patients in the study.Conclusions⁶⁸Ga-PSMA PET/CT alters the therapeutic approach in a substantial proportion of patients with PCa.     

CT和MRI在宫颈癌分期诊断中的临床对比分析

目的：比较CT和MRI在宫颈癌分期诊断中的临床应用价值。方法：回顾性分析宫颈癌患者96例,上述患者均有完整临床资料及术前CT和MRI检查结果,根据术后病理检查结果,比较两种检查方法影像学诊断、侵犯宫颈旁组织、侵犯子宫体、侵犯阴道、淋巴结转移的术前检查结果与病理诊断的符合率。结果：两种检查方法在宫颈癌Ⅰb期、Ⅱa期和Ⅱb期诊断符合率比较差异具有高度统计学意义（P〈0．01）;宫颈癌Ⅲa期和Ⅲb期符合率比较,差异具有统计学意义（P〈0．05）;宫颈癌Ⅳ期符合率比较,差异无统计学意义（P〉O．05）;检查提示侵犯宫颈旁组织、侵犯子宫体与侵犯阴道与术后病理诊断符合率比较,差异具有统计学意义（P〈0．05）。结论：对于宫颈癌患者,术前应积极采取MRI检查方式,可提高诊断符合率,有利于对患者术后治疗的开展和预后的判断。     

扬子鳄胚胎发育分期

本文基于150例不同胎龄的扬子鳄胚胎,将扬子鳄胚胎发育过程分成28个时期。早期胚胎主要以外部形态如体节、体曲程度、脑泡、感觉器官、附肢、鳃弓、颜面部突起、心脏、皮肤等作为分期标准;晚期胚胎主要以器官发育的组织学指标为分期依据。发现在前20个时期中,每个时期的胎龄与密河鳄的很一致,后8个时期的胎龄与密河鳄有差异。分析认为,鳄类晚期胚胎的分期依据应增加器官发育的组织学指标,以便使不同鳄类的胚胎发育有一致的分期标准,为鳄类发育生物学后续研究提供基础资料。     

~(18)F-FDGPET/CT显像对淋巴瘤诊断、分期及疗效评价价值探讨

目的:探讨18氟-氟代脱氧葡萄糖(18F-FDG)PET/CT对淋巴瘤诊断、分期和疗效的评价价值。方法:入选我院2008年1月至2013年1月收治的52例经手术病理证实为淋巴瘤的患者,均进行18F-FDG PET/CT检查,并与病理结果进行比较,评价诊断价值,治疗前后对比分期改变,评价疗效和改变治疗方案。结果:PET/CT诊断发现异常高代谢情况51例(98.1%),其对淋巴瘤检查的灵敏度为98.1%(51/52),诊断率与病理结果比较相当,差异无统计学意义(P0.05),治疗后,11例(21.2%)完全恢复,PET/CT未见高代谢或肿大情况,3例(5.8%)临床分期上调,15例(28.8%)分期下调,其中15例(28.8%)改变治疗方案。结论:18F-FDG PET/CT对淋巴瘤诊断准确性高,在分期和疗效评价中具有重要意义,有助于准确分期并鉴别残余病变性质。     

Breath biomarkers for detection of human liver diseases: preliminary study

Chronic liver disease is initially occult, has multiple aetiologies, involves complex diagnostic questions, and requires follow-up because progression is likely. Blood tests and biopsies are generally used, but have disadvantages. We have developed a new test for liver disease based on abnormal concentrations of metabolic products detected in exhaled breath. This test can be used, in conjunction with other clinically accepted diagnostic protocols, to detect and classify chronic liver diseases. Samples of breath collected from spontaneously breathing human subjects (86 patients presenting with 13 liver diseases and 109 subjects with normal liver function) were concentrated cryogenically and analysed by wide-bore capillary gas chromatography using various detectors. The concentrations of various molecules in exhaled breath were examined for potential use as biomarkers of liver function. Subjects with chronic liver diseases could be differentiated from those with normal liver function by comparing levels of breath carbonyl sulphide, carbon disulphide and isoprene; these differences were confirmed and correlated by comparing the levels with standard clinical blood markers of liver damage. The presence of chronic liver failure can thus be detected with sensitivity and specificity by quantifying sulphur-containing compounds arising from the abnormal metabolism associated with liver disease. The breath test we have developed appears to distinguish between hepatocellular and biliary tract aetiologies, and allows staging for severity. This approach may provide the clinician with a simple, non-invasive technique for use in the screening of large populations and follow-up for patients with chronic liver disease.     

TEP/TDM et cancer pulmonaire : indications et perspectives

Lung cancer is a major public health problem that generates a large number of imaging and acts for diagnostic procedures. The last decade saw the development of positron emission tomography coupled to the scanner (PET/CT), which has significantly improved the staging and allowed to obtain better accuracy in the initial staging. It may change the management of a patient thanks to a better characterization of the initial situation. Several series have to assess performance, often higher than that of CT and there are several recommendations specifying the place of this examination in the management of lung cancer. It also seems to become a complementary tool to the radiotherapist for delineation of volumes to be irradiated using functional information of the tumor. The concept of biological target volume (BTV) has been introduced. There are more perspectives for diagnostic, therapeutic evaluation and prognosis with the study of new tracers, including those of hypoxia and cell proliferation.     

Stages in the development of the embryo of the fresh-water crayfishCherax destructor

Summary Development of the crayfish embryo is described in sequential stages separated by intervals that represent 5% of the total time taken from fertilization to hatching, which is 40 days at 19° C. Early cell division, aggregation of blastoderm cells into the ventral plate, gastrulation and formation of the embryo can be clearly observed through the transparent chorion and each stage characterised using morphological criteria. At hatching the egg chorion splits open but the hatchling (postembryo stage 1) remains attached to the inside of the egg by membranes extending from its tail. 7 to 8 days later the hatchling moults to produce the 2nd post-embryonic stage. Free from the egg, it still clings to the mother. 14 days later the 2nd postembryonic stage moults to produce the immature adult.