Targeting the Phosphatidylserine-Immune Checkpoint with a Small-Molecule Maytansinoid Conjugate

Ligand-targeting drug delivery systems have made significant strides for disease treatments with numerous clinical approvals in this era of precision medicine. Herein, we report a class of small molecule-based immune checkpoint-targeting maytansinoid conjugates. From the ligand targeting ability, pharmacokinetics profiling, in vivo anti-pancreatic cancer, triple-negative breast cancer, and sorafenib-resistant liver cancer efficacies with quantitative mRNA analysis of treated-tumor tissues, we demonstrated that conjugate 40a not only induced lasting regression of tumor growth, but it also rejuvenated the once immunosuppressive tumor microenvironment to an “inflamed hot tumor” with significant elevation of gene expressions that were not accessible in the vehicle-treated tumor. In turn, the immune checkpoint-targeting small molecule drug conjugate from this work represents a new pharmacodelivery strategy that can be expanded with combination therapy with existing immune-oncology treatment options.

Click Chemistry and Multicomponent Reaction for Linker Diversification of Zinc Dipicolylamine-Based Drug Conjugates

An efficient Ugi multicomponent reaction with strain promoted azide-alkyne cycloaddition protocol has been utilized in concert or independently to prepare a small family of bioactive zinc(II) dipicolylamine (ZnDPA)-based SN-38 conjugates. With sequential click chemistry coupling between the cytotoxic payload and phosphatidylserine-targeting ZnDPA ligand derived from structurally diverse carboxylic acids, aldehyde or ketones, and isocyanides, we demonstrated that this convergent synthetic strategy could furnish conjugates harnessing diversified linkers that exhibited different pharmacokinetic profiles in systemic circulation in vivo. Among the eight new conjugates, comparative studies on in vitro cytotoxicities, plasma stabilities, in vivo pharmacokinetic properties, and maximum tolerated doses were then carried out to identify a potent ZnDPA-based SN-38 conjugate that resulted in pancreatic cancer growth regression with an 80% reduction of cytotoxic payload used when compared to that of the marketed irinotecan. Our work provided the roadmap to construct a variety of theranostic agents in a similar manner for cancer treatment.

BPRDP056, a novel small molecule drug conjugate specifically targeting phosphatidylserine for cancer therapy

Zinc(II)-dipicolylamine (Zn-DPA) has been shown to specifically identify and bind to phosphatidylserine (PS), which exists in bulk in the tumor microenvironment. BPRDP056, a Zn-DPA-SN38 conjugate was designed to provide PS-targeted drug delivery of a cytotoxic SN38 to the tumor microenvironment, thereby allowing a lower dosage of SN38 that induces apoptosis in cancer cells. Micro-Western assay showed that BPRDP056 exhibited apoptotic signal levels similar to those of CPT-11 in the treated tumors growing in mice. Pharmacokinetic study showed that BPRDP056 has excellent systemic stability in circulation in mice and rats. BPRDP056 is accumulated in tumors and thus increases the cytotoxic effects of SN38. The in vivo antitumor activities of BPRDP056 have been shown to be significant in subcutaneous pancreas, prostate, colon, liver, breast, and glioblastoma tumors, included an orthotopic pancreatic tumor, in mice. BPRDP056 shrunk tumors at a lower (~20% only) dosing intensity of SN38 compared to that of SN38 conjugated in CPT-11 in all tumor models tested. A wide spectrum of antitumor activities is expected to treat all cancer types of PS-rich tumor microenvironments. BPRDP056 is a first-in-class small molecule drug conjugate for cancer therapy.

Implanted islet mass influences the effects of dipeptidyl peptidase-IV inhibitor LAF237 on transplantation outcomes in diabetic mice

Background

Previous studies showed inconsistent Results of the effects of dipeptidyl peptidase (DPP)-IV inhibitors on syngeneic mouse islet transplantation. We hypothesized that the implanted islet numbers are critical for the effects of DPP-IV inhibitors on the outcomes of transplantation.

Methods

One hundred and fifty or three hundred islets were syngeneically transplanted under the renal capsule of each streptozocin-diabetic C57BL/6 mouse and recipients were then treated without or with LAF237 (10 mg/kg/day, po) for 6 weeks. After transplantation, recipients’ blood glucose, body weight and intraperitoneal glucose tolerance test (IPGTT) were followed-up periodically. The graft was removed for the measurement of β-cell mass at 6 weeks.

Results

In recipients with 150 islets, it was not significantly different between the LAF237- treated group (n = 14) and control group (n = 14) in terms of the blood glucose, body weight, glucose tolerance at 2, 4 and 6 weeks or the graft β-cell mass at 6 weeks. In contrast, in recipients with 300 islets, the LAF237-treated group (n = 24) did have a lower area under the curve of the IPGTT at 4 weeks (p = 0.0237) and 6 weeks (p = 0.0113) as well as more graft β-cell mass at 6 weeks (0.655 ± 0.008 mg vs. 0.435 ± 0.006 mg, p = 0.0463) than controls (n = 24).

Conclusions

Our findings revealed 6-week treatment of LAF237 improves glucose tolerance and increases graft β-cell mass in diabetic mice transplanted with a sufficient number but not a marginal number of islets. These indicate that the effects of DPP-IV inhibitors are influenced by the implanted islet mass.

High-performance FRET biosensors for single-cell and in vivo lead detection

Forms of lead (Pb) have been insidiously invading human life for thousands of years without obvious signs of their considerable danger to human health. Blood lead level (BLL) is the routine measure used for diagnosing the degree of lead intoxication, although it is unclear whether there is any safe range of BLL. To develop a practical detection tool for living organisms, we engineered a genetically encoded fluorescence resonance energy transfer (FRET)-based Pb²⁺ biosensor, 'Met-lead 1.44 M1', with excellent performance. Met-lead 1.44 M1 has an apparent dissociation constant (K_d) of 25.97 nM, a detection limit (LOD) of 10 nM (2.0 ppb/0.2 μg/dL), and an enhancement dynamic ratio of nearly ~ 5-fold upon Pb²⁺ binding. The 10 nM sensitivity of Met-lead 1.44 M1 is five times below the World Health Organization-permitted level of lead in tap water (10 ppb; WHO, 2017), and fifteen times lower than the maximum BLL for children (3 μg/dL). We deployed Met-lead 1.44 M1 to measure Pb²⁺ concentrations in different living models, including two general human cell lines and one specific line, induced pluripotent stem cell (iPSC)-derived cardiomyocytes, as well as in widely used model species in plant (Arabidopsis thaliana) and animal (Drosophila melanogaster) research. Our results suggest that this new biosensor is suitable for lead toxicological research in vitro and in vivo, and will pave the way toward potential applications for both low BLL measures and rapid detection of environmental lead in its divalent form.

Monitoring the Heavy Metal Lead Inside Living Drosophila with a FRET-Based Biosensor

The harmful impact of the heavy metal lead on human health has been known for years. However, materials that contain lead remain in the environment. Measuring the blood lead level (BLL) is the only way to officially evaluate the degree of exposure to lead. The so-called "safe value" of the BLL seems to unreliably represent the secure threshold for children. In general, lead's underlying toxicological mechanism remains unclear and needs to be elucidated. Therefore, we developed a novel genetically encoded fluorescence resonance energy transfer (FRET)-based lead biosensor, Met-lead, and applied it to transgenic Drosophila to perform further investigations. We combined Met-lead with the UAS-GAL4 system to the sensor protein specifically expressed within certain regions of fly brains. Using a suitable imaging platform, including a fast epifluorescent or confocal laser-scanning/two-photon microscope with high resolution, we recorded the changes in lead content inside fly brains ex vivo and in vivo and at different life stages. The blood-brain barrier was found to play an important role in the protection of neurons in the brain against damage due to the heavy metal lead, either through food or microinjection into the abdomen. Met-lead has the potential to be a powerful tool for the sensing of lead within living organisms by employing either a fast epi-FRET microscope or high-resolution brain imaging.

Abstract 227: BPRDP056, a novel small molecule drug conjugate specifically targeting phosphatidylserine for cancer therapy

Zinc(II)-dipicolylamine (Zn-DPA) have been described to specifically complex with phosphatidylserine (PS), which has a higher level at the external surface of cancer cells in tumorigenic condition. BPRDP056 is a Zn-DPA-SN38 conjugate designed to provide a PS-targeting drug delivery of cytotoxic payload SN-38 at the tumor microenvironment, thereby, decrease the dosage of SN38, while induce apoptosis in cancer cells. The in vivo therapeutic efficacy of BPRDP056 against the growths of human tumors has been shown significant in mice subcutaneously bearing a tumor type of pancreas, prostate, colon, liver, breast and glioblastoma, as well as in mice with an orthotopic pancreatic tumor. BPRDP056 shrunk tumors at a lower dosing intensity (~20%) of SN38 compared to CPT-11 in all models tested. Micro-Western assays showed that BPRDP056 exhibited apoptotic cell death signal levels similar to those of CPT-11 in the treated tumors in mice. Furthermore, pharmacokinetic and preliminary toxicology studies showed that BPRDP056 has a good stability in circulation with an acceptable therapeutic safety window in mice. BPRDP056 has been demonstrated with a tumor targeting ability and thus increases the cytotoxic payload SN38 concentration in situ for improved efficacy. Its therapeutic spectrum against malignant neoplasm will be expected to cover the PS-rich tumor microenvironment of all cancer types. BPRDP056 is a first-in-class Small Molecule Drug Conjugate for anti-cancer therapy.

Citation Format: Chia-Yu Hsu, Yun-Yu Chen, Chen-Fu Lo, Tai-Yu Chiu, Ching-Ping Chen, Chen-Lung Huang, Chung-Yu Huang, Min-Hsien Wang, Yu-Sheng Chao, Joe C. Shih, Teng-Kuang Yeh, Lun K. Tsou, Chiung-Tong Chen. BPRDP056, a novel small molecule drug conjugate specifically targeting phosphatidylserine for cancer therapy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 227.

Linker Optimization and Therapeutic Evaluation of Phosphatidylserine-Targeting Zinc Dipicolylamine-based Drug Conjugates

We report that compound 13, a novel phosphatidylserine-targeting zinc(II) dipicolylamine drug conjugate, readily triggers a positive feedback therapeutic loop through the in situ generation of phosphatidylserine in the tumor microenvironment. Linker modifications, pharmacokinetics profiling, in vivo antitumor studies, and micro-Western array of treated-tumor tissues were employed to show that this class of conjugates induced regeneration of apoptotic signals, which facilitated subsequent recruitment of the circulating conjugates through the zinc(II) dipicolylamine-phosphatidylserine association and resulted in compounding antitumor efficacy. Compared to the marketed compound 17, compound 13 not only induced regressions in colorectal and pancreatic tumor models, it also exhibited at least 5-fold enhancement in antitumor efficacy with only 40% of the drug employed during treatment, culminating in a >12.5-fold increase in therapeutic potential. Our study discloses a chemically distinct apoptosis-targeting theranostic, with built-in complementary functional moieties between the targeting module and the drug mechanism to expand the arsenal of antitumor therapy.

Soluble α-synuclein facilitates priming and fusion by releasing Ca2+ from the thapsigargin-sensitive Ca2+ pool in PC12 cells

α-Synuclein is associated with Parkinson's disease, and is mainly localized in presynaptic terminals and regulates exocytosis, but its physiological roles remain controversial. Here, we studied the effects of soluble and aggregated α-synuclein on exocytosis, and explored the molecular mechanism by which α-synuclein interacts with regulatory proteins, including Rab3A, Munc13-1 (also known as Unc13a) and Munc18-1 (also known as STXBP1), in order to regulate exocytosis. Through fluorescence recovery after photobleaching experiments, overexpressed α-synuclein in PC12 cells was found to be in a monomeric form, which promotes exocytosis. In contrast, aggregated α-synuclein induced by lactacystin treatment inhibits exocytosis. Our results show that α-synuclein is involved in vesicle priming and fusion. α-Synuclein and phorbol 12-myristate 13-acetate (PMA), which is known to enhance vesicle priming mediated by Rab3A, Munc13-1 and Munc18-1, act on the same population of vesicles, but regulate priming independently. Furthermore, the results show a novel effects of α-synuclein on mobilizing Ca²⁺ release from thapsigargin-sensitive Ca²⁺ pools to enhance the ATP-induced [Ca²⁺]_i increase, which enhances vesicle fusion. Our results provide a detailed understanding of the action of α-synuclein during the final steps of exocytosis.

Clinical and biophysical characterization of 19 GJB1 mutations

Objective

Charcot–Marie–Tooth disease type X1 (CMTX1), which is caused by mutations in the gap junction (GJ) protein beta‐1 gene (GJB1), is the second most common form of Charcot–Marie–Tooth disease (CMT). GJB1 encodes the GJ beta‐1 protein (GJB1), which forms GJs within the myelin sheaths of peripheral nerves. The process by which GJB1 mutants cause neuropathy has not been fully elucidated. This study evaluated the biophysical characteristics of GJB1 mutants and their correlations with the clinical features of CMTX1 patients.

Methods

All patients with a validated GJB1 mutation were assessed using the Charcot–Marie–Tooth disease neuropathy score version 2 (CMTNS). The impacts of the mutations on the biophysical functions of GJB1 were characterized by assessing intracellular localization, expression patterns, and GJ Ca²⁺ permeability.

Result

Nineteen GJB1 mutations were identified in 24 patients with a clinical diagnosis of CMT. Six are novel mutations: p.L6S, p.I20F, p.I101Rfs*8, p.F153L, p.R215P, and p.D278V. Diverse pathological effects of the mutations were demonstrated, including reduced GJB1 expression, intracellular mislocalization, and altered GJ functions. GJB1 mutations that caused a complete loss of GJ Ca²⁺ permeability appeared to be associated with an earlier disease onset, whereas those resulting in preservation of GJ permeability and with predominant cell membrane expression tended to have a later onset and a milder phenotype.

Interpretation

This study demonstrated that the degree of loss of GJ function caused by the GJB1 mutations might contribute to the onset and severity of neuropathic symptoms in CMTX1.

Interpolation based consensus clustering for gene expression time series

BACKGROUND

Unsupervised analyses such as clustering are the essential tools required to interpret time-series expression data from microarrays. Several clustering algorithms have been developed to analyze gene expression data. Early methods such as k-means, hierarchical clustering, and self-organizing maps are popular for their simplicity. However, because of noise and uncertainty of measurement, these common algorithms have low accuracy. Moreover, because gene expression is a temporal process, the relationship between successive time points should be considered in the analyses. In addition, biological processes are generally continuous; therefore, the datasets collected from time series experiments are often found to have an insufficient number of data points and, as a result, compensation for missing data can also be an issue.

RESULTS

An affinity propagation-based clustering algorithm for time-series gene expression data is proposed. The algorithm explores the relationship between genes using a sliding-window mechanism to extract a large number of features. In addition, the time-course datasets are resampled with spline interpolation to predict the unobserved values. Finally, a consensus process is applied to enhance the robustness of the method. Some real gene expression datasets were analyzed to demonstrate the accuracy and efficiency of the algorithm.

CONCLUSION

The proposed algorithm has benefitted from the use of cubic B-splines interpolation, sliding-window, affinity propagation, gene relativity graph, and a consensus process, and, as a result, provides both appropriate and effective clustering of time-series gene expression data. The proposed method was tested with gene expression data from the Yeast galactose dataset, the Yeast cell-cycle dataset (Y5), and the Yeast sporulation dataset, and the results illustrated the relationships between the expressed genes, which may give some insights into the biological processes involved.

Downregulation of DAB2IP promotes mesenchymal-to-neuroepithelial transition and neuronal differentiation of human mesenchymal stem cells

The DOC-2/DAB2 interactive protein (DAB2IP) is a new member of the Ras GTPase–activating protein family. Recent studies have shown that, in addition to its tumor suppressive role in various tumors, DAB2IP also plays an important role in regulating neuronal migration and positioning during brain development. In this study, we determined the roles of DAB2IP in the neuronal differentiation of human mesenchymal stem cells (hMSCs). We found that lentiviral short hairpin RNA (shRNA)-mediated knockdown of DAB2IP promoted the mesenchymal-to-neuroepithelial stem cell transition (MtNeST) and neuronal differentiation, which were accompanied by a reduction of cell proliferation but not apoptosis or cellular senescence. This suggests that DAB2IP plays an important role in the neuronal induction of hMSCs. Moreover, our finding that reduction of glycogen synthase kinase 3 beta (GSK3β) activity upon LiCl pretreatment inhibited both the MtNeST and production of MAP2-positive cells upon DAB2IP knockdown suggests that this transition is most likely mediated by regulation of the GSK3β signaling pathway. Our study demonstrates that DAB2IP participates in the first step of neuron induction of hMSCs, which implies a potentially important role for DAB2IP in the MtNeST during neurogenesis.

The effectiveness of anaerobic digestion in removing estrogens and nonylphenol ethoxylates

The fate and behaviour of two groups of endocrine disrupting chemicals, steroid estrogens and nonylphenol ethoxylates, have been evaluated during the anaerobic digestion of primary and mixed sewage sludge under mesophilic and thermophilic conditions. Digestion occurred over six retention times, in laboratory scale reactors, treating sludges collected from a sewage treatment works in the United Kingdom. It has been established that sludge concentrations of both groups of compounds demonstrated temporal variations and that concentrations in mixed sludge were influenced by the presence of waste activated sludge as a result of transformations during aerobic treatment. The biodegradation of total steroid estrogens was >50% during primary sludge digestion with lower removals observed for mixed sludge, which reflected bulk organic solids removal efficiencies. The removal of nonylphenol ethoxylates was greater in mixed sludge digestion (>58%) compared with primary sludge digestion and did not reflect bulk organic removal efficiencies. It is apparent that anaerobic digestion reduces the concentrations of these compounds, and would therefore be expected to confer a degree of protection against exposure and transfer of both groups of compounds to the receiving/re-use environment.

Visualization of the Orai1 homodimer and the functional coupling of Orai1-STIM1 by live-cell fluorescence lifetime imaging

The Orai1-STIM1 constructed store-operated Ca2+ channels (SOCs) have been found to exert several essential Ca2+ entry/signaling cascades, e.g., the generation of immune response in T lymphocytes. Although biochemical and novel imaging evidence appear to indicate that Orai1 and STIM1 interact with each other to achieve store-operated Ca2+ entry (SOCE), the detailed mechanism of functional SOCE in situ has yet to be fully understood. In this study, green fluorescence protein (EGFP as donor) targeted to either the N- or C-terminal of Orai1 (wild type or delta1-90+delta267-301 double deletion type) and mOrange (as acceptor) tagged STIM1 were used to comprise a fluorescence resonance energy transfer (FRET) pair within living PC12 cells. The fluorescence lifetime map and histogram/distribution of each single cell, determined by one-photon excitation fluorescence lifetime imaging microscopy (FLIM), was used to visualize FRET and show the Orai1 homodimer and Orai1-STIM1 binding. Both the color-coded lifetime map and the distribution of EGFP-tagged Orai1 significantly changed after the administration of thapsigargin, the SOCE stimulating agent. The FRET efficiency from each experimental set was also calculated and compared using double exponential analysis. In summary, we show the detailed interactions Orai1-Orai1 and Orai1-STIM1 within intact living cells by using the FLIM-FRET technique.

Cyanide removal from cassava mill wastewater using Azotobactor vinelandii TISTR 1094 with mixed microorganisms in activated sludge treatment system

Cassava mill wastewater has a high organic and cyanide content and is an important economic product of traditional and rural low technology agro-industry in many parts of the world. However, the wastewater is toxic and can pose serious threat to the environment and aquatic life in the receiving waters. The ability of Azotobactor vinelandii TISTR 1094, a N2-fixing bacterium, to grow and remove cyanide in cassava wastewater was evaluated. Results revealed that the cells in the exponential phase reduce the level of cyanide more rapidly than when the cells are at their stationary growth phase. The rate of cyanide removal by A. vinelandii depends on the initial cyanide concentration. As the initial cyanide concentration increased, removal rate increased and cyanide removal of up to 65.3% was achieved. In the subsequent pilot scale trial involving an activated sludge system, the introduction of A. vinelandii into the system resulted in cyanide removals of up to 90%. This represented an improvement of 20% when compared to the activated sludge system which did not incorporate the strain.

Fate and occurrence of alkylphenolic compounds in sewage sludges determined by liquid chromatography tandem mass spectrometry

An analytical method has been developed and applied to determine the concentrations of the nonionic alkylphenol polyethoxylate surfactants and their metabolites, alkylphenoxy carboxylates and alkyphenols, in sewage sludges. The compounds were extracted with methanol/acetone (1:1 v/v) from sludge, and concentrated extracts were cleaned by silica solid-phase extraction prior to determination by liquid chromatography tandem mass spectrometry. The recoveries, determined by spiking sewage sludge at two concentrations, ranged from 51% to 89% with method detection limits from 6 microg kg(-1) to 60 microg kg(-1). The methodology was subsequently applied to sludge samples obtained from a carbonaceous activated sludge plant, a nitrifying/denitrifying activated sludge plant and a nitrifying/ denitrifying activated sludge plant with phosphorus removal. Concentrations of nonylphenolic compounds were two to three times higher than their octyl analogues. Long-chain nonylphenol polyethoxylates (NP3-12EO) ranged from 16 microg kg(-1) to 11754 microg kg(-1). The estrogenic metabolite nonylphenol was present at concentrations ranging from 33 microg kg(-1) to 6696 microg kg(-1).

Automated recognition system to classify subcellular protein localizations in images of different cell lines acquired by different imaging systems

Systemic analysis of subcellular protein localization (location proteomics) provides clues for understanding gene functions and physiological condition of the cells. However, recognition of cell images of subcellular structures highly depends on experience and becomes the rate-limiting step when classifying subcellular protein localization. Several research groups have extracted specific numerical features for the recognition of subcellular protein localization, but these recognition systems are restricted to images of single particular cell line acquired by one specific imaging system and not applied to recognize a range of cell image sources. In this study, we establish a single system for automated subcellular structure recognition to identify cell images from various sources. Two different sources of cell images, 317 Vero (http://gfp-cdna.embl.de) and 875 CHO cell images of subcellular structures, were used to train and test the system. When the system was trained by a single source of images, the recognition rate is high and specific to the trained source. The system trained by the CHO cell images gave high average recognition accuracy for CHO cells of 96%, but this was reduced to 46% with Vero images. When we trained the system using a mixture of CHO and Vero cell images, an average accuracy of recognition reached 86.6% for both CHO and Vero cell images. The system can reject images with low confidence and identify the cell images correctly recognized to avoid manual reconfirmation. In summary, we have established a single system that can recognize subcellular protein localizations from two different sources for location-proteomic studies. studies.

Good death study of elderly patients with terminal cancer in Taiwan

OBJECTIVES

Over half of all terminal cancer patients in Taiwan are 65 or older, thus demonstrating the importance of terminal care for elderly people. This study investigates the good death status of elderly patients with terminal cancer, comparing the differences in the degree of good death among elderly and younger groups, and exploring the factors related to the good death score.

METHODS

Three hundred and sixty-six patients with terminal cancer admitted to a palliative care unit were enrolled. Two structured measurements, the good death scale and the audit scale for good death services, were used as the instruments in the study.

RESULTS

The scores of individual items and of the good death scale were increased significantly in both elderly (n = 206, 56.3%) and younger (n = 160, 43.7%) groups from the time of admission to just prior to death. However, the elderly group had significantly lower scores in 'awareness' (t = -3.76, P < 0.001), 'propriety' (t = -2.92, P < 0.01) and 'timeliness' (t = -2.91, P < 0.01) than the younger group prior to death. Furthermore, because of a lack of truth-telling, the elderly group also had significantly lower scores than the younger group in both 'respect for autonomy' and 'decision-making participation' (t = -2.17, P < 0.05; t = -2.21, P < 0.05, respectively). Multiple regression analysis revealed that 'respect for autonomy' (OR = 1.22, 95% CI = 0.76-1.67) and 'verbal support '(OR = 0.93, 95% CI = 0.34-1.51) were two independent correlates of the good death score in the elderly group.

CONCLUSION

The dilemma of truth-telling compromises the autonomy of the elderly patients with terminal cancer and consequently affects their good death scores. The palliative care team should emphasize the issue of truth-telling in the process of caring for terminally ill cancer patients, especially elderly patients.

Treatment and removal strategies for estrogens from wastewater

Natural and synthetic steroidal estrogens (estrone, 17beta-estradiol and 17alpha-ethinylestradiol) are endocrine disrupters, that are discharged consistently from the sewage treatment works into surface waters, thereby causing endocrine disrupting effects to aquatic organisms at trace concentrations (nanogram per litre). Several years of research have been focused on their fate, behaviour and removal in the environment but primarily in the sewage treatment works which acts as a sink for these compounds. This review attempts to summarize the factors involved in the removal of these chemicals from the sewage treatment works. Biological processes, and to a limited extent physio-chemical properties, play a vital role in the endocrinal deactivation of these compounds. The efficiency of these processes is highly dependent on operating parameters (such as sludge retention time, redox potential, etc) that govern the secondary treatment process of a functional sewage treatment works. Although advanced treatment technologies are available, cost and operational considerations do not make them a sustainable solution.

An automated tracking system to measure the dynamic properties of vesicles in living cells

Recent technological improvements have made it possible to examine the dynamics of individual vesicles at a very high temporal and spatial resolution. Quantification of the dynamic properties of secretory vesicles is labor-intensive and therefore it is crucial to develop software to automate the process of analyzing vesicle dynamics. Dual-threshold and binary image conversion were applied to enhance images and define the areas of objects of interest that were to be tracked. The movements, changes in fluorescence intensity, and changes in the area of each tracked object were measured using a new software system named the Protein Tracking system (PTrack). Simulations revealed that the system accurately recognized tracked objects and measured their dynamic properties. Comparison of the results from tracking real time-lapsed images manually with those automatically obtained using PTrack revealed similar patterns for changes in fluorescence intensity and a high accuracy (<89%). According to tracking results, PTrack can distinguish different vesicular organelles that are similar in shape, based on their unique dynamic properties. In conclusion, the novel tracking system, PTrack, should facilitate automated quantification of the dynamic properties of vesicles that are important when classifying vesicular protein locations.

Hepatitis B virus infection in children and adolescents in a hyperendemic area: 15 years after mass hepatitis B vaccination

BACKGROUND

Hepatitis B virus (HBV) infection is hyperendemic in Taiwan. Before universal HBV immunization was started in Taiwan in 1984, the carrier rate for hepatitis B surface antigen (HBsAg) was 15% to 20% in the general population.

OBJECTIVE

To quantify the population impact of a mass vaccination program for HBV 15 years after its implementation.

DESIGN

Descriptive analysis of serologic markers of HBV in healthy children and adolescents.

SETTING

Chung-Cheng District, Taipei City, Taiwan, in 1999.

PARTICIPANTS

1357 persons younger than 15 years of age, who were born after the implementation of universal HBV vaccination, and 559 persons 15 to 20 years of age, who were born before the program began.

MEASUREMENTS

Repeated serologic surveys similar to those done before and 5 and 10 years after the national vaccination program was implemented. All participants were tested for serum HBsAg, its antibody (anti-HBs), and hepatitis B core antibody (anti-HBc).

RESULTS

During the 15 years since the vaccination program was implemented, the prevalence of HBsAg among persons younger than 15 years of age decreased from 9.8% in 1984 to 0.7% in 1999; among persons 15 to 20 years of age, the 1999 prevalence of HBsAg was 7% (P < 0.001). Hepatitis B core antibody seropositivity, which represents HBV infection, was found in 2.9% of persons younger than 15 years of age and in 20.6% of persons 15 to 20 years of age (P < 0.001); in the same age groups, the rate of anti-HBs seropositivity was 75.8% and 70.7%, respectively (P = 0.02).

CONCLUSIONS

Universal vaccination significantly decreased the HBV carrier rate and infection rate among children and adolescents born since the program began. By decreasing the carrier pool, continuation of the national HBV immunization program should prevent HBV infection in the children of Taiwan, and, subsequently, adults as well.

Sedation for refractory symptoms of terminal cancer patients in Taiwan

This study assessed sedation in terminal cancer patients in terms of three characteristics: frequency; relationship to intractable symptoms; and the extent to which medical staff, family, and patients found sedation to be ethically acceptable and efficacious. Two hundred seventy-six consecutive patients, who were admitted to the palliative care unit of National Taiwan University Hospital in Taiwan between August 1998 and the end of May 1999, were enrolled. A recording form was completed every day. This included demographic data, pain and common symptom scores, and the use of sedation in the terminal phase. Seventy (27.9%) of 251 patients who died received sedation. Sedation was administered to relieve agitated delirium in 40 (57.1%), dyspnea in 16 (22.8%), severe pain in 7 (10%) and insomnia in 5 (7.2%). The drugs used for sedation were haloperidol in 35 (50%), midazolam in 17 (24.3%), and rapidly increasing dosage of morphine in 9 (12.9%). In fewer than half (42.9%) of the patients, sedation was with the consent of both patient and family, and half (50%) had the consent of family alone. The overwhelming majority of medical staff and family felt the decision to use terminal sedation was ethically acceptable. There was no significant difference in survival time between sedated and non-sedated patients (28.49 vs. 24.71 days, t = -0.791, P = 0.430). Positive ethical acceptability and higher satisfaction with symptom control with terminal sedation were found in both medical staff and family in this study. Further work is needed to find the most appropriate time of intervention and to improve management of refractory symptoms in dying patients.

Immunogenicity and reactogenicity of the combined hepatitis A and B vaccine in young adults

The combination of hepatitis A virus (HAV) and hepatitis B virus (HBV) vaccinations can offer convenience, increased compliance and cost saving. We have studied the immunogenicity, reactogenicity and safety of combined hepatitis A and B vaccination in young adults (16-35 years old). Eighty healthy young adults were divided into two random groups. One group received the combined hepatitis A and B vaccine (HAB) in one arm while the other group was administered concomitant hepatitis A and B vaccines (HAV + HBV) in the right and left arms, respectively. The immunogenicity, reactogenicity and safety were assessed after each dose in both the groups. In local symptoms, the percentage of the combined HAB group was lower than the HAV + HBV group, and the general symptoms were noted in approximately 30% of each group without any significant difference. No serious adverse effects were noted. All the subjects were seropositive for antibody to hepatitis A virus (anti-HAV) after one dose of vaccine, and remained seropositive after three doses in both groups. The seropositive rate for antibody to hepatitis B surface antigen (anti-HBs) was significantly higher (84%) in the combined HAB group than the concomitant HAV + HBV group (62%), (p<0.05) after dose two, and all the subjects were seropositive (100%) after the third dose. The GMTs of anti-HAV and anti-HBs were not significantly different between groups 1 and 2 (p>0.1) except in month 6 when the GMT of anti-HBs was higher in HAB group (p=0.0039). The combined HAB vaccine was found to be safe, well tolerated and had less local symptoms in young adults. The immunogenicity and reactogenicity were similar to the concomitant HAV + HBV vaccines.

Ethical dilemmas in palliative care: a study in Taiwan

OBJECTIVES

To investigate the incidence and solution of ethical dilemmas in a palliative care unit.

DESIGN

Health care workers recorded daily all dilemmas in caring for each patient.

SETTING

Palliative care unit of National Taiwan University Hospital in Taiwan.

PATIENTS

Two hundred and forty-six consecutive patients with terminal cancer during 1997-8.

MAIN MEASUREMENT

Ethical dilemmas in the questionnaire were categorised as follows: telling the truth; place of care; therapeutic strategy; hydration and nutrition; blood transfusion; alternative treatment; terminal sedation; use of medication, and others.

RESULTS

The type and frequency of ethical dilemmas encountered were: place of care (33.3%); truth-telling (32.1%); hydration and nutrition (25.2%); therapeutic strategy (24.8%), and use of medication (19.1%). Ethical problems relating to the place of care and to therapeutic strategy were unlikely to be solved with increased hospital stay and some ethical dilemmas remained unsolved even in the final week in hospital, including place of care (23.2%), truth-telling (17.1%) and therapeutic strategy (11.4%). Problems of truth-telling occurred in nearly half (42.6%) of patients over sixty-five-years-old. Conflicts about blood transfusion were experienced in all patients below 18-years-old, and the dilemmas concerning the place of care occurred most frequently with head and neck cancer patients (43.8%).

CONCLUSIONS

The solution of ethical dilemmas required refocusing by medical professionals on the importance of continuing communication. Improved ethical training for professionals would contribute to solving the moral dilemmas of palliative care.

Prevalence and severity of symptoms in terminal cancer patients: a study in Taiwan

This paper reports a prospective study conducted between September 1997 and July 1998 in 232 consecutive patients with terminal cancer. A structured data collection form was used daily to evaluate symptoms, which were analyzed at the time of admission, 1 week after admission and 48 h before death. Terminal cancer patients in this study were polysymptomatic. There were no statistically significant differences in the prevalence of most symptoms with the primary site of cancer. The majority of symptoms improved at the end of the 1st week after admission, but many symptoms worsened just before death. The high prevalence of symptoms and lack of significant difference among primary tumor sites may be related to shorter survival times caused by late referral, which is common in Taiwan.

Penile cancer in Taiwan--20 years' experience at National Taiwan University Hospital

To analyze the characteristics and prognostic factors of penile cancer in Taiwanese, we retrospectively reviewed the clinical data of patients with a diagnosis of penile cancer treated during a 20-year period (1977-1996) at National Taiwan University Hospital (NTUH). Of 71 patients treated for penile cancer during the study period, 17 were referred from other hospitals or clinics. Our analyses focused on the 54 previously untreated patients. Growth on the penis was the main symptom in all cases. Palpable inguinal lymph nodes were found only in 14 patients. All 54 patients with primary tumors were treated surgically. Pathologic examination showed squamous cell carcinoma (SCC) in 43 cases, extra-mammary Paget's disease in three, verrucous carcinoma in three, Bowen's disease in two, cutaneous lymphoma in two and basal cell carcinoma in one. Twenty-six (48%) patients had stage I penile cancer, 13 (24%) had stage II, seven (13%) had stage III, and eight (15%) had stage IV cancer. The five-year survival rate was 78% among patients with SCC and 84% among those with nonsquamous malignancies (p = 0.80). The five-year cumulative survival rates according to Jackson's cancer stage were 100% for patients with stage I, 88.9% for those with stage II, 66.7% for those with stage III, and 0% for those with stage IV (p < 0.001). Tumor staging (p = 0.027) and adjuvant chemotherapy (p = 0.042) were found to be the most significant prognostic factors. Penile cancer accounted for 0.254% of all malignancies among male patients at the NTUH during the study period. Our findings indicate that penile cancer is uncommon in Taiwanese and its prognosis is closely related to tumor staging and management. Early diagnosis and appropriate treatment may lead to prolonged survival.

Treating benign prostatic hyperplasia with finasteride in Chinese men: one-year experience

To evaluate the long-term efficacy and safety of finasteride in the treatment of symptomatic benign prostatic hyperplasia (BPH), 50 patients with symptomatic BPH were initially evaluated in a double blind, placebo-controlled study for 6 months. The patients were then treated with finasteride in an open extension study in which all received the same dose of finasteride (5 mg/day) for another 6 months. Among the patients (n = 23) who completed the extension study, prostate volume was significantly reduced from baseline by 15%, maximum urine flow rate improved by 1.9 mL/second, symptom scores improved by 37% and serum prostatic specific antigen (PSA) level decreased by 1.34 ng/mL. Other than serum PSA level, these data differed insignificantly from data at the end of the first 6 months. The adverse events observed at the end of the first 6 months (two patients with decreased sexual libido and two with impotency) persisted throughout the study extension period. At the end of the 12 months study, one more patient reported decreased libido. The sustained clinical efficacy and low incidence of side-effects of daily treatment with finasteride 5 mg for 1 year indicate that finasteride is safe and effective for managing symptomatic BPH in Chinese men.

Simple nephrectomy by retroperitoneoscope

Retroperitoneoscopic simple nephrectomy was successfully performed in 10 of 12 patients with nonfunctioning kidneys. The other two patients underwent traditional open surgery. The surgical procedures, technical pitfalls, surgical results and perisurgical complications of this simple retroperitoneoscopic approach are described. Retroperitoneoscopic nephrectomy is a viable alternative for simple nephrectomy and has the benefits of minimal invasiveness, more rapid convalescence and better quality of life for patients.

Relationship between serum prostate specific antigen concentration and prostate volume

Serum prostate-specific antigen (PSA) levels and prostate volume were evaluated in 553 healthy men aged 40 to 79 years, who entered a study program for benign prostatic hyperplasia from December 1993 to August 1994. Digital rectal examination (DRE), transrectal ultrasonography (TRUS) and serum PSA assay were performed on all participants. After excluding men with suspected prostate cancer and incomplete data, 542 cases qualified for analysis. The mean serum PSA level was 1.4 +/- 1.7 ng/mL which increased with age from 0.8 +/- 0.9 ng/mL in men aged 40 to 49 years to 2.7 +/- 2.8 ng/mL in those aged 70 to 79 years. In this study group, 250 men (46.1%) were documented to have various degrees of benign prostatic hyperplasia (BPH). The prostate volume averaged 22.3 +/- 9.1 mL which increased from 18.5 +/- 6.1 mL in the fifth decade to 27.2 +/- 13.7 mL in the eighth decade. There was a modest correlation between serum PSA level and both age and prostate volume. However, when the prostate volume was adjusted, the PSA level correlated more weakly with age in a multivariate analysis. On the other hand, the serum PSA level correlated more strongly with prostate volume when age was adjusted. Although 5.4% of the men had serum PSA levels > 4 ng/mL, there was no evidence of prostate cancer by DRE and TRUS. Serum PSA levels increased with age and prostate volume, and correlated better with the latter. These factors should be taken into account when determining the significance of a given PSA value in a patient without clinical evidence of prostate cancer.

Therapeutic effects of finasteride in benign prostatic hyperplasia: a randomized double-blind controlled trial

The clinical effects of finasteride, a 5 alpha-reductase inhibitor, in patients with benign prostatic hyperplasia (BPH) were evaluated in a double-blind, placebo-controlled study. Forty-six patients with symptomatic BPH were randomly assigned to 2 groups, the finasteride group and the placebo group. The finasteride group received 5 mg of finasteride daily for 6 months. Prostate volume, urinary flow, urinary symptoms, serum prostate-specific antigen (PSA) and adverse events were determined before and after treatment. After 6 months of treatment the patients treated with 5 mg of finasteride per day had a 30% decrease in their total urinary symptom score, a 14% decrease in prostate volume and a 0.9 ng/dL decrease of PSA. Their maximal urinary flow rate increased by 1.42 mL per second and the mean urinary flow rate increased by 0.64 mL per second. The patients given placebo showed no significant changes in their prostate volume, serum PSA and maximal and mean urinary flow rate. However, the symptom scores in the placebo group also decreased significantly. When compared with the placebo group, those in the finasteride group had significantly lower prostate volume, serum PSA, maximal urinary flow rate and urinary symptoms, but not mean urinary flow rate. The frequency of adverse events was low in both the finasteride and placebo groups. These results show that finasteride may be an effective and safe alternative for the treatment of patients with BPH.

Renal hemodynamics in patients with obstructive uropathy evaluated by duplex Doppler sonography

Duplex Doppler sonography was performed to differentiate varied degrees of obstructive uropathy by demonstrating the intrarenal arterial impedance in terms of pulsatility index and resistive index. We evaluated 56 kidneys in 28 normal subjects and 53 kidneys in 27 patients with unilateral or bilateral obstructive uropathy. The degrees of renal obstruction were determined by clinical criteria, such as excretory urography, antegrade pyelography and/or retrograde ureteral catheterization. There was excellent positive correlation between pulsatility index and resistive index values (correlation coefficient 0.77, p < 0.001). In patients with obstructive uropathy there were significant differences in pulsatility index and resistive index values between the 33 obstructed and 20 nonobstructed kidneys (p < 0.001 for both indexes). Significant differences were also found between the obstructed kidneys and the kidneys of normal subjects (p < 0.001 for both indexes) even after controlling for the age factor (p < 0.001). No difference was found between the nonobstructed kidneys of the patient group and those of normal subjects (p = 0.58 and 0.45 for pulsatility and resistive indexes, respectively). The resistive index values correlated well with the degrees of obstruction (p < 0.001). The mean resistive index values for mildly and significantly obstructed kidneys were 0.64 +/- 0.08 and 0.74 +/- 0.05, respectively. More than 93.3% of the significantly obstructed kidneys had resistive index values greater than or equal to 0.70. The obstruction may be significant and demands surgical intervention when the resistive index reaches that value. In contrast, with resistive index values of less than 0.70 renovascular resistance is minimally altered and obstruction may be mild. The results can be applied clinically to help justify the indications for surgical intervention to relieve symptoms of obstructive uropathy.

Characterization of a newly established human bladder carcinoma cell line, NTUB1

A new human bladder cancer cell line, NTUB1, has been derived from the surgical specimen of a 70-year-old female patient diagnosed with poorly differentiated transitional cell carcinoma. It has been successfully propagated in vitro for over 24 months without evidence of reaching senescence. Population doubling time was about 21 hours at the 32nd passage. It was tumorigenic in nude mice, and the histologic findings of the heterotransplanted tumor resembled the original tumor. Expression of keratin proteins confirmed its epithelial origin. Cytogenetic analysis showed multiple chromosome changes. Anticancer drugs, including thiotepa and adriamycin, were tested in vitro, and the cytotoxicity did not exceed 50% of the control value; likewise, in this patient chemotherapy was not effective. On the other hand, a combination of recombinant tumor necrosis factor and interferon tau in vitro was more effective against this tumor.

Serum level of immunosuppressive acidic protein in patients with urological malignancies

Immunosuppressive acidic protein (IAP) is a non-specific immunoreactive protein arising from inflammatory or malignant conditions in the human body. We determined the IAP levels in 65 cases with urological malignancies and in 31 cases with benign diseases as a control group during a 9-month period. There were significantly higher serum levels of IAP in cases of bladder transitional cell carcinoma (p = 0.025), prostate adenocarcinoma (p less than 0.00001) and upper urinary tract urothelial cancer (kidney and/or ureter, p = 0.013) as compared with those of the control group. Significant differences in IAP between different tumor stages were found in the bladder cancer group with high stage cases having higher IAP levels (p less than 0.0005). However, no significant differences were found between different tumor gradings. Most of the prostate cancer patients had extremely high IAP values (1,029 +/- 490 micrograms/ml) in this study. Renal cell carcinoma and testicular tumors showed no statistical differences from the control group (p = 0.89 and 0.37, respectively). No differences could be found in the different age groups (by decades) or sexes. The serum IAP level can be a good non-specific tumor marker for bladder cancer staging and probably a good follow-up tool for most urological malignancy patients.