Recommendations for the management of advanced and metastatic renal cell carcinoma: joint consensus statements from the Hong Kong Urological Association and the Hong Kong Society of Uro-Oncology

INTRODUCTION

Kidney cancer, primarily renal cell carcinoma (RCC), ranks among the top 10 most common malignancies in the male population of Hong Kong. In 2019, members of two medical societies in Hong Kong formed an expert panel to establish a set of consensus statements for the management of metastatic RCC. On 22 June 2021, the same panel met to review recent evidence and reassess their positions regarding the management of advanced and metastatic RCC, with the aim of providing recommendations for physicians in Hong Kong.

PARTICIPANTS

The panel included 12 experts (6 clinical oncologists and 6 urologists) who had extensive experience managing patients with RCC in Hong Kong.

EVIDENCE

The panel reviewed randomised controlled trials, observational studies, systematic reviews/meta-analyses, and international clinical guidelines to address key clinical questions that were identified before the meeting.

CONSENSUS PROCESS

In total, 15 key clinical questions were identified before the meeting, covering the surgical and systemic treatment of advanced or metastatic clear cell, sarcomatoid, and non-clear cell RCCs. At the meeting, the panellists voted on these questions, then discussed relevant evidence and practical considerations.

CONCLUSIONS

The treatment landscape for advanced and metastatic RCC continues to evolve. More immune checkpoint inhibitor (ICI)-based combination regimens will be indicated for the treatment of metastatic clear cell RCC. There is increasing evidence concerning the benefit of adjuvant ICI treatment for resected advanced RCC. This article summarises recent evidence and expert insights regarding a series of key clinical questions about the management of advanced and metastatic RCC.

Anti-Quorum Sensing Activity of Forsythia suspense on Chromobacterium violaceum and Pseudomonas aeruginosa

Background:

Quorum sensing (QS) plays an important role in the production of virulence factors and pathogenicity in Pseudomonas aeruginosa, and the interruption of QS will be a hopeful pathway to combat bacterial infection.

Objective:

In this study, we selected Forsythia suspense (Thunb.) Vahl from traditional Chinese herbal medicines for its anti-QS activity.

Materials and Methods:

Anti-QS of F. suspense extracts (FSE) was monitored using the Chromobacterium violaceum 12472 bioassay. Standard methods were used to investigate the effects of FSE on QS-controlled virulence factors production, swimming motility, and biofilm establishment in P. aeruginosa PAO1.

Results:

FSE could obviously inhibit the violacein production in C. violaceum 12472 and also could inhibit quorum sensing–regulated virulence factors production and biofilm formation in P. aeruginosa in a concentration-dependent manner. The elastase activity and pyocyanin production were inhibited at a maximum of 40.97 and 47.58% when P. aeruginosa was grown in the presence of 0.25 g/mL FSE, which can also inhibit swimming motility of P. aeruginosa. The biofilm formation ability was decreased about 72.45% when in PAO1 cultured with the 0.25 g/mL FSE. The results suggested that FSE may be used as an alternative drug to control and handle harmful infections caused by bacterial pathogens based on QS inhibition.

SUMMARY

Forsythia suspense water extract could obviously inhibit the purple pigment production in C. violaceum 12472

Forsythia suspense water extract could inhibit QS-regulated virulence factors production and biofilm formation in P. aeruginosa.

Abbreviations used: QS: Quorum sensing, Pseudomonas aeruginosa P. aeruginosa, Forsythia suspense F. suspense, FSE: F. suspense extracts, Chromobacterium violaceum 12472 C. violaceum 12472, AIs: autoinducers, AHLs: N-acyl-homoserinelactones, LB: Luria-Bertani, MICs: Minimum inhibitory concentrations, CFU: Colony-Forming Units, ATCC: American Type Culture Collection, PBS: phosphate buffered saline

Connexin 43 reverses malignant phenotypes of glioma stem cells by modulating E-cadherin

Malfunctioned gap junctional intercellular communication (GJIC) has been thought associated with malignant transformation of normal cells. However, the role of GJIC-related proteins such as connexins in sustaining the malignant behavior of cancer stem cells remains unclear. In this study, we obtained tumorspheres formed by glioma stem cells (GSCs) and adherent GSCs and then examined their GJIC. All GSCs showed reduced GJIC, and differentiated glioma cells had more gap junction-like structures than GSCs. GSCs expressed very low level of connexins, Cx43 in particular, which are key components of gap junction. We observed hypermethylation in the promoter of gap junction protein α1, which encodes Cx43 in GSCs. Reconstitution of Cx43 in GSCs inhibited their capacity of self-renewal, invasiveness, and tumorigenicity via influencing E-cadherin and its coding protein, which leads to changes in the expression of Wnt/β-catenin targeting genes. Our results suggest that GSCs require the low expression of Cx43 for maintaining their malignant phenotype, and upregulation of Cx43 might be a potential strategy for treatment of malignant glioma.

Giant urethral diverticulum calculus presenting as scrotal abscess

We report herein a patient with a urethral calculus associated with urethral diverticulum. A 39-year-old man presented with scrotal swelling and acute retention of urine. Computed tomography of the pelvis and cystoscopy demonstrated a giant calculus in the proximal penile urethra. Emergency in-situ lithotripsy was performed. Complete stone clearance was achieved and a large urethral diverticulum was encountered. The rare occurrence of urethral diverticulum and associated stone disease were discussed.

Beyond-limit light focusing in the intermediate zone

We experimentally verify that a new nanolens of a designed plasmonic aperture can focus visible light to a single line with its width smaller than the limit of half the wavelength in the intermediate zone. The experimental measurement indicates that while the near field plays a role to increase the spot size in the near zone, it is negligible at the beyond-limit focused region; i.e., the focused light is dominated by the radiative fields. The image taken by the optical microscope shows that the fields focused have propagated to the far zone. Besides being of academic interest, the nanolens capable in achieving a lower diffraction limit in the intermediate zone is important for application possibilities.

Characteristic of algogenic organic matter and its effect on UF membrane fouling

Algogenic organic matter (AOM) was extracted from blue-green algae (cyanobacteria) and its characteristic was determined by various methods including high-pressure size-exclusion chromatography (HP-SEC), hydrophobic and hydrophilic fractionation, molecular weight (MW) fractionation and fluorescence excitation emission matrix (EEM). The results revealed that AOM was hydrophilic fractionation predominantly, accounting for 78%. The specific ultraviolet absorbance of AOM was 1.1 L/(mg m) only. The analysis for MW distribution demonstrated that organic matter greater than 30,000 MW accounted for over 40% and was composed of mostly neutral hydrophilic compound. EEM analyses revealed that protein-like and humic-substances existed in AOM. A test for membrane filtration exhibited that AOM could make ultrafiltration membrane substantial flux decline, which can be attributed to membrane pore clog caused by neutral hydrophilic compound with larger MW.

Effect of oral immunization with Aeromonas hydrophila ghosts on protection against experimental fish infection

AIMS

To investigate whether oral immunization with Aeromonas hydrophila ghosts (AHG) vaccine can elicit mucosal and systemic immune responses of Carp (Carassius auratus gibelio) compared to conventional formalin-killed bacteria (FKC).

METHODS AND RESULTS

Fish were fed diets coated with AHG, FKC or phosphate buffered saline (PBS) alone, after immunization, more antigen-specific antibody was significantly detected in serum and intestinal mucus in AHG group than FKC group and PBS group. In addition, after challenged with the parent strain J-1, the survival of bacterial ghost-vaccinated fish was higher than PBS group and FKC group, the relative per cent survival (RPS) being 76.8%, 58.9%, respectively.

CONCLUSIONS

Oral immunization with A. hydrophila ghosts can elicit systemic and mucosal adaptive immune responses and has higher potential to induce protective adaptive immunity than normal vaccine.

SIGNIFICANCE AND IMPACT OF THE STUDY

Oral immunization with bacterial ghosts is a promising new solution with potential application to prevent diseases in fish.

Optimization of extracellular alkaline protease production from species of Bacillus

Thirty-five strains capable of secreting extracellular alkaline proteases were isolated from the soil and waste water near the milk processing plant, slaughterhouse. Strain APP1 with the highest-yield alkaline proteases was identified as Bacillus sp. The cultural conditions were optimized for maximum enzyme production. When the initial pH of the medium was 9.0, the culture maintained maximum proteolytic activity for 2,560 U ml(-1) at 50 degrees C for 48 h under the optimized conditions containing (g(-1)): soyabean meal, 15; wheat flour, 30; K(2)HPO(4), 4; Na(2)HPO(4), 1; MgSO(4) x 7H(2)O, 0.1; Na(2)CO(3), 6. The alkaline protease showed extreme stability toward SDS and oxidizing agents, which retained its activity above 73 and 110% on treatment for 72 h with 5% SDS and 5% H(2)O(2), respectively.

Microfabricated biocapsules provide short-term immunoisolation of insulinoma xenografts

This study examines the viability and functionality of two insulinoma cell lines, RIN (1048) and betaTC6F7, encapsulated within microfabricated biocapsules. Surface and bulk micromachining are integrated in the biocapsule fabrication process, resulting in a diffusion membrane with uniform pore size distribution as well as mechanical and chemical stability, surrounded by an anisotropically-etched silicon wafer, which serves as the encapsulation cavity. Insulinoma cells (4500 cells/biocapsule) were enclosed within these microfabricated biocapsules and subjected to a static incubation study after either implantation in BALB-C mice or incubation in vitro. Examination of retrieved microfabricated biocapsules revealed an insulin stimulatory index of approximately 1.5 for encapsulated RIN cells and 3.6 for encapsulated betaTC6F7 cells for biocapsules with 18 nm pore sized microfabricated membranes, similar to indices of biocapsules incubated in vitro. There was an 80% decrease in cell stimulatory response between in vitro and in vivo 66 nm-biocapsules as compared to 20% for 18 nm-biocapsules, indicating that the immunoisolatory effectiveness depends greatly on achieving uniform pore sizes in the size range of 18 nm or smaller. The present study demonstrates the feasibility of using microfabricated biocapsules for the immunoisolation of insulinoma cells lines. The microfabricated biocapsule may serve as an alternative to conventional polymeric based biocapsules for possible use as in vivo insulin secreting bioreactor.

Role of Microfilaments and Microtubules in the Invasion of EPC Cells by Aeromonas hydrophila

The influence of the cytoskeleton on the invasion of Aeromonas hydrophila strain AhJ-1, isolated from diseased fish, in the monolayer cell of epithelioma papillosum cells of carp (EPC) was evaluated by the recovery of gentamicin-resistant bacteria from Triton X-100 cell lysates. The depolymerization of microfilaments (MF) by cytochalasin B and D inhibited the uptake of A. hydrophila in a dose-dependent manner and that of microtubules (MT) by colchicines and nocodazole did not affect the invasion of A. hydrophila in EPC cells significantly. The invasion frequency decreased approximately 62% with the addition of 0.1 microg/ml cytochalasin D and nearly 86% by the addition of 5.0 microg/ml. Invasion decreased approximately 49% and 83% by addition of cytochalasin B in a concentration of 2.5 microg/ml and 10.0 microg/ml. Colchicine and nocodazole, inhibitors of MT formation appears to have little effect on the invasion of EPC cells by strain Ah J-1. Thus MF formation, but not MT formation seems to play an important role in the internalization of A. hydrophila J-1.

A simplified risk-based approach for process screening in municipal wastewater reclamation and reuse

Reuse of municipal wastewater has become a promising solution to relieve the tension of increasing fresh water demand in many metropolitans. Although different advanced technologies are available to reclaim wastewater into premium quality, associated health effects are usually not properly assessed in reclamation process selection. A simplified risk-based approach developed for process screening and adaptation of health impacts as a consideration in reclamation process selection is discussed in this paper. This approach can be used to screen out unqualified processes and those with poor cost benefits. As a result, the design of wastewater reclamation could be enhanced to control the associated health impacts in wastewater reuse.

Microfabricated immunoisolating biocapsules

A microfabricated silicon-based biocapsule for the immunoisolation of cell transplants is presented. The biocapsule-forming process employs bulk micromachining to define cell-containing chambers within single crystalline silicon wafers. These chambers interface with the surrounding biological environment through polycrystalline silicon filter membranes. The membranes are surface micromachined to present a high density of uniform pores, thus affording sufficient permeability to oxygen, glucose, and insulin. The pore dimensions, as small as 20 nm, are designed to impede the passage of immune molecules and graft-borne viruses. The underlying filter-membrane nanotechnology has been successfully applied in controlled cell culture systems (Ferrari et al., 1995), and is under study for viral elimination in plasma fractionation protocols. Here we report the encouraging results of in vitro experiments investigating the biocompatibility of the microfabricated biocapsule, and demonstrate that encapsulated rat neonatal pancreatic islets significantly outlive and outperform controls in terms of insulin-secretion capability over periods of several weeks. These results appear to warrant further investigations on the potential of cell xenografts encapsulated within microfabricated, immunoisolating environments for the treatment of insulin-dependent diabetes.

Prostatein C3-mRNA: a sensitive marker of androgen-responsiveness in prostate explant cultures

Prostatein is an androgen-dependent protein which is secreted by the rat ventral prostate. To determine if prostatein or its mRNA were responsive to androgen in vitro, prostate explants were cultured in media containing 0 or 25 nM dihydrotestosterone (DHT), estradiol (E2), or cortisol (F). Prostatein concentrations in medium were measured by radioimmunoassay at 2 and 4 days and in homogenates at 4 days. They were not changed significantly by any of these steroids. The concentration of the mRNA for the C3-subunit of prostatein was determined by dot hybridization at 0, 2, 4, 6, and 8 days. It was decreased significantly by 2 days when compared with explants cultured in the presence of DHT and significant differences persisted through 8 days. In conclusion, quantitation of the mRNA for the C3-subunit of prostatein in short-term cultures of ventral prostate explants appears to be more sensitive to changes in androgen concentration than does measurement of prostatein, per se. Prostatein C3-mRNA may be a useful marker for in vitro studies of androgen agonists and antagonists.

Maternal cell contamination in cultured chorionic villi: comparison of chromosome Q-polymorphisms derived from villi, fetal skin, and maternal lymphocytes

Maternal cell contamination of chorionic villi (CV) samples used for first trimester prenatal diagnosis can cause obvious and/or unrecognized diagnostic dilemmas. The purpose of this investigation is to assess the frequency of maternal cell contamination (MCC) in chorionic villus samples and to evaluate selected parameters which might predict where contamination is more likely to have occurred. Maternal lymphocytes, chorionic villi from ultrasonically directed transcervical catheter aspiration, and fetal tissue were obtained at 8-11 weeks gestation from 45 patients undergoing elective termination. Quinacrine (Q) banded metaphases were compared from duplicate direct preparations of chorionic villi; cultured chorionic villi, fetal fibroblast tissue cultures, and maternal lymphocyte cultures. Q-polymorphisms in metaphase chromosomes were 100 per cent concordant between fetal tissue and direct CV preparation. However, evidence for maternal cell contamination occurred in 13.1 per cent of cultured chorionic villi preparations where polymorphisms were found to be identical between maternal and cultured CV and both distinct from fetal tissue preparations. Where MCC was identified, it was noted that CV cell cultivation interval was prolonged (24.2 +/- 6.8 days) compared with non-contaminated cultures (14.1 +/- 4.4 days) (p less than 0.05). We conclude that maternal cell contamination is a significant problem with chorionic villus sampling. Where direct preparations are not employed or when cultures are 'slow growing', MCC may be a significant and unrecognized complication re: fetal diagnosis. Direct preparations, multiple cultures, quinacrine banding, and maternal Q-polymorphism comparisons can minimize diagnostic dilemmas secondary to maternal cell contamination.(ABSTRACT TRUNCATED AT 250 WORDS)