[Research progress in the diagnosis and management of proliferative verrucous leukoplakia]

Proliferative verrucous leukoplakia (PVL) is one of the oral potentially malignant disorders (OPMD) with the highest malignant potential. PVL tends to be easily misdiagnosed owing to the resemblance in clinical manifestations between PVL and other diseases such as oral leukoplakia or oral lichen planus. PVL is considered as a special type of oral leukoplakia by some scholars, which is characterized by its tendency of recurrence and metastasis, along with its high risk of malignant transformation. So far, the accurate clinic diagnosis and management of PVL are still intractable due to the lack of definite histopathological definition, unified diagnostic criteria and effective treatment modalities. This review aims to provide the clinical practitioners with a series of advices on the clinical diagnosis and management of PVL by systematically reviewing the diagnostic logistics, therapeutic strategies, malignant transformation detection based on tremendous relevant data and evidence-based medicine.

Stereotactic radiosurgery and anti-PD-1 + CTLA-4 therapy, anti-PD-1 therapy, anti-CTLA-4 therapy, BRAF/MEK inhibitors, BRAF inhibitors, or conventional chemotherapy for the management of melanoma brain metastases

BACKGROUND

Immunotherapy and targeted BRAF/MEK inhibitors (i) have revolutionised the systemic management of advanced melanoma. Given the role of stereotactic radiosurgery (SRS) in the local management of brain metastases, we sought to evaluate clinical outcomes in patients with melanoma brain metastases (MBM) treated with SRS and various systemic therapies.

METHODS

Patients were included if MBM were diagnosed and treated with SRS within 3 months of receiving anti-PD-1+CTLA-4 therapy, anti-PD-1 therapy, anti-CTLA-4 therapy, BRAF/MEK-i, BRAF-i, or conventional chemotherapy. Comparisons between groups were made for overall survival (OS), distant MBM control, local MBM, systemic progression-free survival (sPFS), and neurotoxicity.

RESULTS

In total, 257 patients with 1048 MBM treated over 368 SRS sessions between 2011 and 2020 were identified. On MVA, treatment with anti-PD1+anti-CTLA-4, anti-PD-1, and BRAF/MEK-i improved distant intracranial control over conventional chemotherapy. No significant differences were noted in local control (LC) between groups (p = 0.78). Kaplan-Meier OS at 12 months for anti-PD-1 + CTLA-4 therapy, anti-PD-1 therapy, anti-CTLA-4 therapy, BRAF/MEK-i, BRAF-i, and conventional chemotherapy was 68%, 59%, 45%, 62%, 21%, and 15%, respectively (p = <0.0001). The sPFS rates at 12 months were 57%, 53%, 42%, 45%, 14%, and 6% (p = <0.0001). No significant differences were noted in rates of radiation necrosis (p = 0.93).

CONCLUSIONS

This is among the largest series evaluating MBM treated with SRS and various systemic therapy regimens. Our analysis noted significant differences in OS, distant MBM control, and sPFS by systemic therapy. No differences in LC or radiation necrosis risk were noted.

Artificial intelligence in endoscopy: Overview, applications, and future directions

Since the emergence of artificial intelligence (AI) in medicine, endoscopy applications in gastroenterology have been at the forefront of innovations. The ever-increasing number of studies necessitates the need to organize and classify applications in a useful way. Separating AI capabilities by computer aided detection (CADe), diagnosis (CADx), and quality assessment (CADq) allows for a systematic evaluation of each application. CADe studies have shown promise in accurate detection of esophageal, gastric and colonic neoplasia as well as identifying sources of bleeding and Crohn's disease in the small bowel. While more advanced CADx applications employ optical biopsies to give further information to characterize neoplasia and grade inflammatory disease, diverse CADq applications ensure quality and increase the efficiency of procedures. Future applications show promise in advanced therapeutic modalities and integrated systems that provide multimodal capabilities. AI is set to revolutionize clinical decision making and performance of endoscopy.

Acquired Fanconi Syndrome from Tenofovir Treatment in a Patient with Hepatitis B

Fanconi syndrome is a rare disease of generalized proximal tubule dysfunction which can be acquired secondary to certain medications, including tenofovir, a commonly used hepatitis B treatment. Signs and symptoms of ensuing renal wasting can be severe but vague, leading to potentially avoidable invasive investigations and delays in diagnosis. We present a case of a 62-year-old female with chronic hepatitis B on tenofovir treatment who was found to have subacute weakness, anorexia, and weight loss. She underwent extensive investigations including computed tomography (CT) imaging, bronchoscopy, upper and lower endoscopy, and psychiatric evaluation. Finally, persistent electrolyte derangements led to urine studies, which demonstrated acquired Fanconi syndrome secondary to tenofovir. After discontinuing tenofovir disoproxil fumarate and starting tenofovir alafenamide, her symptoms resolved and her renal function recovered. This case illustrates the importance of maintaining clinical suspicion for tenofovir-induced Fanconi syndrome, given the common use of tenofovir as first-line hepatitis B treatment and the availability of less nephrotoxic alternatives.

A132 A CASE OF COLONIC MALAKOPLAKIA PRESENTING AS A LARGE CECAL MASS : NOT EVERY POLYP HAS TO LOOK LIKE A NAIL

Background

Malakoplakia is a rare inflammatory condition, commonly affecting the genitourinary system of immunocompromised patients. Gastrointestinal malakoplakia has been reported in the literature, with previous endoscopic findings mimicking mass lesions.

Purpose

To describe a case of colonic malakoplakia after referral for endoscopic management of a large non-pedunculated colorectal polyp.

Method

Case report and review of the literature.

Result(s)

Case Report

An 80-year-old male with chronic kidney disease and remote renal transplant on immunosuppressive therapy (mycophenolate mofetil, tacrolimus, prednisone) was referred for endoscopic resection for a large non-pedunculated colorectal polyp in the cecum. Original presenting symptoms included chronic diarrhea, iron deficiency anemia, and fecal immunochemical test (FIT) positivity. A repeat colonoscopy demonstrated a 40mm Paris 0-IIA plaque-like lesion in the cecum with optical features not in keeping with adenomatous or serrated histopathology. Biopsies were performed with histopathology demonstrating normal colonic mucosa with confluent sheets of histiocytes with concentrically layered cytoplasmic inclusions, in keeping with malakoplakia.

Literature review

Malakoplakia, Greek for “soft plaque”, is a rare inflammatory condition characterized by impaired dysfunction in macrophages leading to the accumulation of incompletely degraded bacteria in phagolysosomes. Histologically, this appears as concentrically layered cytoplasmic inclusions, comprising the pathognomonic Michaelis-Gutmann bodies. Many bacterial organisms have been implicated in the development of malakoplakia, with E. coli being the most common; specifically in immunocompromised patients, whether from immunosuppressive medications, immunodeficiency syndromes, or clinical conditions precluding effective immune function. Malakoplakia commonly presents as a mass-like lesion and has been found in all organs, most commonly in the genitourinary system. Diagnosis is made by biopsy and allows for appropriate treatment, which is most commonly a reduction in immunosuppressive therapy and antibiotic therapy.

Image

Conclusion(s)

Malakoplakia is rare but should be considered when a lesion with atypical optical evaluation features is found in immunocompromised individuals or those with recurrent infections.

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None

Disclosure of Interest

None Declared

A138 SERRATED POLYPOSIS SYNDROME IN INFLAMMATORY BOWEL DISEASE: A SEQUELAE OF CHRONIC DISEASE ACTIVITY OR NEW WHO PHENOTYPE?

Background

Serrated polyposis syndrome (SPS) is a growing health concern with up to 1 in 125 universal screening program participants meeting diagnostic criteria. Conversely, SPS in inflammatory bowel disease (IBD) is rarely described in the literature, despite the predisposition for serrated epithelial change and serrated polyps in this population.

Purpose

To describe a case of World Health Organization (WHO) criterion I SPS in a patient with IBD, and discuss the existing literature on this rare occurrence.

Method

Case report and review of the literature.

Result(s)

Case Report

A 53-year-old female with ulcerative colitis (UC; Phenotype: Left-sided; Duration of disease: 40 years; Medical therapy: sulfasalazine) undergoing regular endoscopic surveillance was recently found to have multiple serrated-class lesions including 6 in the sigmoid colon ranging between 8-30mm in size; this included 3 sessile serrated lesions (SSLs) between 20-30mm removed by piecemeal cold snare resection without complication and 2 residual large SSLs for staged endoscopic resection. No endoscopic disease activity was appreciated (Mayo 0), with histopathology of the sigmoid colon and rectum demonstrating chronic inactive colitis.

Literature Review

From 2008 to 2021, there are eleven reported cases of SPS in IBD. Six patients had UC and most were in remission for several decades at the time of SPS diagnosis. Most SPS cases met WHO criteria and fit within described phenotypes. While the case above meets WHO criterion I for SPS, the presence of large distal lesions is atypical, raising the question of whether chronic disease activity contributed to the development of these serrated lesions, given the known predisposition for serrated epithelial change and serrated lesions in patients with colonic IBD.

Image

Conclusion(s)

SPS in patients with IBD is rare. Questions remain about the role of chronic disease activity contributing to the formation of serrated lesions, its clinical relevance, and optimal management strategy.

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None

Disclosure of Interest

None Declared

Hemostatic powders for gastrointestinal bleeding: a review of old, new, and emerging agents in a rapidly advancing field

Background and study aims  Hemostatic powders are increasingly used to address limitations in conventional endoscopic techniques for gastrointestinal bleeding. Various agents exist with different compositions, characteristics, efficacy, and adverse events (AEs). We sought to review existing hemostatic powders, from preclinical to established agents. Methods  A literature review on hemostatic powders for gastrointestinal bleeding was undertaken through a MEDLINE search from 2000-2021 and hand searching of articles. Relevant literature was critically appraised and reviewed for mechanism of action, hemostasis and rebleeding rate, factors associated with hemostatic failure, and AEs. Results  The most established agents are TC-325 (Hemospray), EndoClot, and Ankaferd Blood Stopper (ABS). These agents have been successfully applied to a variety of upper and lower gastrointestinal bleeding etiologies, in the form of primary, combination, salvage, and bridging therapy. Few AEs have been reported, including visceral perforation, venous embolism, and self-limited abdominal pain. Newer agents include CEGP-003 and UI-EWD, which have shown results similar to those for the older agents in initial clinical studies. All aforementioned powders have high immediate hemostasis rates, particularly in scenarios not amenable to conventional endoscopic methods, but are limited by significant rates of rebleeding. Other treatments include TDM-621 (PuraStat) consisting of a liquid hemostatic agent newly applied to endoscopy and self-propelling thrombin powder (CounterFlow Powder), a preclinical but promising agent. Conclusions  Rapid development of hemostatic powders and growing clinical expertise has established these agents as a valuable strategy in gastrointestinal bleeding. Further research will continue to refine the efficacy and applicability of these agents.

Survey of the Impact of COVID-19 on Chronic Liver Disease Patient Care Experiences and Outcomes

Background

The COVID-19 pandemic has a secondary impact on the health of patients with chronic liver disease (CLD). Our objective was to study this impact on care provision, telemedicine, and health behaviours in CLD patients.

Methods

CLD patients of an urban gastroenterology clinic who attended a telemedicine appointment between March 17, 2020 and September 17, 2020, completed an online survey on care delays, health behaviours, and experience with telemedicine. Chart review was conducted in 400 randomly selected patients: 200 charts from during the pandemic were compared to 200 charts the previous year. Data were extracted for clinicodemographic variables, laboratory investigations, and clinical outcomes.

Results

Of 399 patients invited to participate, 135 (34%) completed the online survey. Fifty (39%) patients reported 83 care delays due to the COVID-19 pandemic, with the majority (71%) of delays persisting beyond 2 months. Ninety-five (75%) patients were satisfied with telemedicine appointments. There was a longer delay between lab work and appointments in patients seen during the pandemic compared to 2019 (P = 0.01). Compared to the year prior, during the COVID pandemic, there was a similar number of cases of cirrhosis decompensation (n = 26, 13% versus n = 22, 11%) and hospitalization (n = 12, 6% versus n = 5, 3%).

Conclusion

The COVID-19 pandemic has led to care delays for CLD outpatients, with most delays on the scale of months. These patient-reported experiences and clinical observations can direct optimization of CLD care as effects from the pandemic evolve.

A137 AN ELUSIVE GASTROINTESTINAL BLEED: A CASE OF RUPTURED CYSTIC ARTERY PSEUDOANEURYSM WITH PREVIOUS BILLROTH-II SURGERY

Background

Cystic artery pseudoaneurysm (CAP) is a rare but potentially life-threatening cause of upper gastrointestinal (GI) bleeding and requires urgent intervention.

Aims

To describe the clinical enigma of CAP in the context of distorted anatomy and discuss management.

Methods

Case report and review of literature

Results

Case Report

A healthy 91-year-old man with a remote history of gastric ulcer perforation leading to Billroth-II surgery 40 years ago presented to a community hospital with melena. He had no abdominal pain and liver enzymes were normal. His hemoglobin was 97 g/L (from 137 g/L the month prior) with a BUN:Cr ratio of 50.6 mg/dL and white cell count of 14.4 x109/L. Upper endoscopy identified a large adherent clot in the stomach that could not be dislodged and was suspected to obscure the culprit lesion. Afferent and efferent limbs from previous Billroth-II surgery were identified but not intubated. He was managed supportively with acid suppression and blood transfusion, but his hemoglobin continued decreasing, leading to transfer to a tertiary centre. Upon arrival he had new-onset abdominal pain, rigors, and diaphoresis with a heart rate of 175 beats/minute and blood pressure of 75/40 mmHg. After resuscitation, emergent CT angiogram demonstrated acute contrast extravasation into the gallbladder in keeping with a ruptured CAP. He underwent successful coiling of the cystic artery. Following this, his abdominal pain resolved, and hemoglobin stabilized. Repeat endoscopy demonstrated Billroth-II anatomy without bleeding lesion. He was treated with antibiotics for presumed cholecystitis and discharged home for outpatient cholecystectomy.

Literature Review

CAP is a rare cause of hemobilia, described only in case reports. The complete hemobilia triad of jaundice, right upper quadrant pain, and GI bleeding is absent in the majority of cases, requiring endoscopic evaluation of the ampulla of Vater or contrast CT. The most common causes of CAP are iatrogenic from cholecystectomy, cholecystitis, gallstones, and malignancy. These mechanisms, whether through trauma or inflammation, lead to damage of the gallbladder wall and the cystic artery. Contained CAP can lead to intermittent bleeding whereas ruptured CAP causes brisk arterial bleeding, necessitating arterial embolization or emergent cholecystectomy. In cases of biliary obstruction, either from the original process or subsequent blood clot at the ampulla, ERCP can lead to successful decompression.

Conclusions

We present a case of ruptured CAP which eluded diagnosis due to diagnostic rarity, lack of clinical clues, and distorted anatomy. CAP should be considered with a history of recent cholecystectomy, acute cholecystitis, or gallstones. Maintaining an index of suspicion for rare causes of GI bleeding can ensure timely diagnosis and escalation to the appropriate level of care.

Funding Agencies

None

A256 SURVEILLANCE OF SMALL, NON-FUNCTIONING, ASYMPTOMATIC PANCREATIC NEUROENDOCRINE TUMORS: THE BRITISH COLUMBIA EXPERIENCE

Background

Expert consensus surrounding surveillance for small, non-functioning, asymptomatic pancreatic neuroendocrine tumors (PNETs) remains conflicting. Recent observational studies have shown that surveillance is a safe strategy while large database studies show superior overall survival with surgical resection.

Aims

To describe the growth of small (&lt;2cm), non-functioning, asymptomatic PNETs undergoing surveillance at a tertiary hospital in British Columbia.

Methods

We conducted a retrospective case series of patients with biopsy-proven, non-functioning, asymptomatic PNETs which were &lt;2cm by RECIST criteria at diagnosis, who were followed through active surveillance at Vancouver General Hospital, British Columbia from February 1, 2011-February 1, 2021. Patients were included if serial imaging, whether by endoscopic ultrasound or cross-sectional imaging, was available for a minimum of 24 months.

Results

Of the 57 patients with pathology-proven PNETs that were identified, 14 cases were included after excluding those with resection within 1 year (n=17), lost to follow up (n=13), metastatic disease (n=6), size greater than 2cm at diagnosis (n=4), and with concurrent cancer (n=3). Included patients were predominantly female (n=10, 71%), Caucasian (n=8, 57%), and had a mean Charlson comorbidity index of 3.14. Mean PNET size at diagnosis was 12mm with standard deviation of 4.26mm. Tumors were located in the pancreatic head (n=4, 29%), body (n=6, 42%), and tail (n=4, 29%). Of 8 patients who had Ki67 stains, all were &lt;3%, and of 11 patients with mitotic index, all had &lt;2 mitotic figures. As such, of the 8 patients with available WHO grading, all were grade 1. The average follow-up was 49.6 months with an average tumor growth of 0.82mm per year. When grouping these tumors by growth, 9 (62%) tumors exhibited no growth, 2 tumors grew &lt;1mm per year, 2 tumors grew 1-1.5mm per year, and 1 tumor grew 7.7mm per year. Two cases (14%) of PNETs underwent surgical resection due to size surpassing 2 cm. No patients undergoing surveillance developed metastatic disease.

Conclusions

To our knowledge, we have performed the first Canadian series of small, low-grade PNETS and demonstrated that active surveillance is a safe strategy with most tumors exhibiting no growth of several years. Of the subset of PNETs which demonstrate progression, the preceding surveillance strategy did not disadvantage patients in terms of progression to metastases and allowed for delay of potentially morbid surgery. Further research with prospective studies and larger samples should be conducted.

Funding Agencies

CAG

A214 SIMPLIFICATION OF CARE FOR HCV IS EFFECTIVE DURING THE COVID PANDEMIC: A RETROSPECTIVE STUDY OF HCV TREATMENT UTILIZING THE BRITISH COLUMBIA HEPATITIS C NETWORK

Background

The COVID-19 pandemic has impacted healthcare access, including to curative treatment for hepatitis C (HCV) infection in the form of direct-acting antivirals (DAAs). A 49% decrease in DAA dispensations in Canada during the pandemic has been reported, but little is known about these treated populations.

Aims

To explore the patient characteristics and treatment patterns in those who were treated for HCV during the COVID pandemic.

Methods

A retrospective chart review was conducted at one site of utilizing the British Columbia Hepatitis C Network. Only patients included into the database were analyzed. Patients started on treatment between 03/17/2020-03/16/2021 were included as the “pandemic group” and patients from the 03/17/2019-03/16/2020 were included as a comparison “pre-pandemic group”. Data were extracted for clinicodemographic variables, laboratory investigations, treatment start date, regimen, and sustained virologic response at 12 weeks (SVR12).

Results

97 patients were treated during the pandemic compared to 143 patients the year prior, representing a 32% decline. Patients treated during the pandemic were predominantly new referrals (n=70, 72% vs n=64, 45% pre-pandemic, p&lt;0.01) and had fewer total appointments (median 2 per patient vs 4 per patient pre-pandemic, p&lt;0.01). There was a median of 1 in-person visit and 1 telehealth appointment per patient during the pandemic (vs median 2 per patient of each type pre-pandemic).

Pandemic patients were younger (mean age 56.0 years vs 59.6 pre-pandemic, p=0.04), and a greater proportion were on opioid agonist therapy (28% vs 13% pre-pandemic, p&lt;0.01). Less transient elastography (TE) was performed during the pandemic (69% vs 89% pre-pandemic). Amongst those with TE scores, a lower proportion of those treated during the pandemic were cirrhotic (13% vs 21% pre-pandemic).

During the pandemic, treatment patterns shifted towards more prescriptions for glecaprevir/pibrentasvir (56% of all prescriptions vs 44% pre-pandemic) and sofosbuvir/velpatasvir (37% vs 29% pre-pandemic). There was slightly less use of sofosbuvir/velpatasvir/voxilaprevir at (2% vs 4% pre-pandemic).

The proportion of patients who completed lab work for SVR was similar during the pandemic (n=83/97, 85.6%) compared to pre-pandemic (n=120/143, 83.9%). Similarly, SVR12 remained high during the pandemic at 98.7% (vs 99.3% pre-pandemic). Of all 97 patients prescribed DAAs during the pandemic, 92 (94.8%) completed treatment.

Conclusions

Less persons were treated during the COVID pandemic, which may deter progress towards HCV elimination targets. Very high SVR12 and treatment completion rates during the pandemic suggest that patients can be effectively treated with less pre-treatment investigations and fewer appointments.

Funding Agencies

None

Non-alcoholic fatty liver disease (NAFLD) in Filipino North American patients: Results from a multi-ethnic cohort

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) is more prevalent in certain ethnicities due to a combination of genetic, environmental, and metabolic factors. North American Filipino populations may have lifestyle and metabolic risk factors for NAFLD; however, the prevalence of NAFLD in this group is unknown. We sought to determine whether Filipino patients are over-represented in a multi-ethnic NAFLD cohort and describe their clinical presentation, primarily compared to other ethnicities in the same geographical region and secondarily compared to Manila-based Filipino patients.

METHODS

A cross-sectional study was conducted with patients with NAFLD who were followed at the Hepatology Clinic at Vancouver General Hospital, Canada, from January 2015 to August 2018. Data were extracted for clinicodemographic data, ethnicity, anthropometric measures, blood work, and transient elastography (TE). External comparison data was obtained online from the Metro Vancouver census and a NAFLD study conducted in Manila, Philippines.

RESULTS

Of 317 patients meeting inclusion criteria for the study, 224 patients had complete datasets. The mean age was 51.1 years, and 50% were female. There were 139 (62%) Caucasian and other ethnicity patients, 55 (25%) Asian patients, and 30 (13%) Filipino patients. Compared to other ethnic groups, the Filipino group had similar clinical characteristics, including NAFLD fibrosis scores and TE. Of included NAFLD patients, the proportion of Filipino patients (13.39%) was significantly greater than the proportion of Filipino residents in Metro Vancouver (5.52%, p <0.01). Our Filipino Canadians seemed to be younger, with fewer females and a lower proportion of diabetes mellitus, but a higher proportion of hypertension than the previously reported cohort from Manila.

CONCLUSIONS

While Filipino patients have not previously been examined in multi-ethnic NAFLD studies, they may represent a high-risk population. Further research is needed to clarify the prevalence and presentation of NAFLD in Filipino Canadian patients, as this appears to be a significant health issue in this community.

Structure-dependent electrical conductivity of protein: its differences between alpha-domain and beta-domain structures

Electron transports in the α-domain and β-domain of proteins have been comprehensively investigated. The structure-dependent electron transport of proteins has been experimentally measured and theoretically simulated, and both the theoretical and experimental results demonstrate significant differences in electrical conductivity between the α-domain and β-domain. By controlling the feedback system of the scanning tunneling microscope (STM), the conductance of a single α-domain protein hemoglobin (Hgb) and a β-domain protein superoxide dismutase enzyme (SOD) were measured, respectively. The current signal of Hgb is obviously stronger, indicating that the α-domain is more conductive. To confirm our finding, molecular orbitals of both the β-domain in SOD and α-domain in Hgb have been analyzed based on first-principles calculations. As expected, tunneling transport and hopping in the α-domain are both more efficient, indicating that it is easier for electrons to transport through the α-domain, which are in great agreement with our experimental data. In order to explain our results, molecular structures of α- and β-domains have been carefully analyzed and show that the explanation should lie in the differences in packing mode between the α-domain and β-domain. This research should be very important to application prospects in molecular electronics.

First Report of Pine Wilt Disease Caused by Bursaphelenchus xylophilus on Pinus thunbergii in the Inland City of Zibo, Shandong, China

The pinewood nematode (PWN) Bursaphelenchus xylophilus (Steiner & Buhrer 1934) Nickle 1970 is the causal agent of pine wilt disease. It is especially damaging in East Asian countries, including Japan, China, and Korea. In China, the nematode has been found in Anhui, Guangdoung, Guizhou, Chongqing, and Zhejiang Provinces since its discovery in Jiangsu Province in 1982 (1). China is confronted with an enormous threat to its pine forests. B. xylophilus is transmitted by the insect vector pine sawyer beetle (Monochamus alternatus). The main host trees are Pinus massoniana, P. thunbergii, and P. densiflora, which are the most common pine trees in China. Shandong Province, located north of Jiangsu Province, is a high-risk area because it was thought to be the northernmost suitable area for the pine wood nematode. P. tabulaeformis, P. densiflora, and P. thunbergii are the principal hosts. In 2010, a pine tree with suspected wilt disease was found in Lushang Forest (36°16'31.11″ N, 118°03'59.79″ E) of P. thunbergii located in Zibo city of Shandong Province. Symptoms were systemic, with almost all leaves brown or yellowish; the tree was nearly dead. Wood samples were collected and nematodes were extracted using a modified Baermann's funnel method. After 12 h, the nematodes were collected from the wood chips, and their morphology was observed with an inverted light microscope (Nikon 90i, Japan). Nematodes had a typical Aphelenchoid-type esophagus and female vulva flap. Females had subcylindrical tails, usually with broadly rounded terminus, some with a short mucro, and flat vulva, whereas males had large paired arcuate spicules with a sharply pointed prominent rostrum, and typical disc-like expansions on distal ends. Standard measurements of these nematodes were as follows: 25 females: body length = 960.9 ± 117.4 (791.5 to 1,265.2) μm, a = 32.1 ± 5.1 (23.7 to 44.5), b = 13.6 ± 1.4 (11.4 to 16.1), c = 28.3 ± 4.6 (21.7 to 42.2), V = 77.8 ± 2.0 (74.2 to 83.9), stylet length = 13.7 ± 1.6 (11.4 to 17.6) μm; 21 males: body length = 785.6 ± 103.2 (609.6 to 1,004.5) μm, a = 33.3 ± 4.4 (26.0 to 40.8), b = 11.9 ± 1.3 (9.0 to 14.6), c = 31.0 ± 2.7 (25.5 to 37.1), stylet length = 13.5 ± 1.9 (11.0 to 17.5) μm, spicule length = 18.8 ± 2.5 (14.9 to 23.9) μm. The morphometrics of this population, apart from body length and "a" value, which are shorter than the Portugal isolate measured by Mota et al. (3), are very much in the same range reported for B. xylophilus. For a more accurate identification, DNA was extracted from individual nematodes using a liquid nitrogen method. The internal transcribed spacers (ITS-1, ITS-2, 5.8S) were amplified by using PCR (2). Nucleotide sequences were compared with the sequences of B. xylophilus in GenBank, accession nos. JN684828 (Portugal), JN684829 (Portugal), JF826219 (Madeira Island) and JQ288086 (Japan). The ITS DNA sequences of the nematode from P. thunbergii were 99% identical to those of B. xylophilus in GenBank. A sequence of this nematode was submitted to the GenBank database and assigned the number KC460340. We have thus confirmed that B. xylophilus is now present north of Changjiang River in Zibo city, Shandong Province. This range expansion, perhaps the result of global warming, will affect both domestic and international quarantine efforts to control the further spread of pinewood nematode. References: (1) X. Y. Cheng et al. Heredity 100:356, 2008. (2) K. Metge and W. Burgermeister. J. Plant Dis. Protect. 113:275, 2006. (3) M. Mota et al. Nematology 1:727, 1999.

Hyalinizing spindle cell tumor with giant rosettes: report of a case showing remarkable myofibroblastic differentiation

We examined the proliferative activity and the differentiation line of tumor cells in a case of "hyalinizing spindle cell tumor with giant rosettes" (HSCGR). A 6 cm tumor within the right deltoid muscle of a 58-year-old female was found by physical and radiographical examinations. A biopsy revealed the histological features of a spindle cell tumor with rosette-like structures. Wide excision was done under the diagnosis of HSCGR. The tumor presented as a gray-whitish, solid mass with focal pseudocystic degeneration. Immunohistochemically, the tumor cells were diffusely positive for vimentin and were also focally positive for S-100, but negative for desmin and alpha-smooth muscle actin. The cells stained positively for Ki-67 with even distribution, there being a correlation with the cellularity of the areas, with a labeling index ranging from 0.3 to 0.5%. In addition, flow cytometry revealed an almost normal diploid DNA pattern and 5.8% S-phase fraction, indicating low proliferative activity. Ultrastructurally, many tumor cells displayed discontinuous basal lamina, pinocytotic vesicles, dilated rough endoplasmic reticulum, and microfilaments with focal dense bodies. The main component of the rosette was collagenous fibrils with normal diameter and normal periodic banding. We interpreted this case of HSCGR as a low grade fibrosarcoma with remarkable differentiation of myofibroblastic lineage, and with focally accumulated, morphologically normal collagenous fibrils.

Antitumor effect of bcl-2 antisense phosphorothioate oligodeoxynucleotides on human renal-cell carcinoma cells in vitro and in mice

BACKGROUND AND PURPOSE

Programmed cell death is a genetically regulated pathway that is altered in many cancers. This process is, in part, regulated by the bcl-2 oncogene. Antisense oligodeoxynucleotides (ODNs) targeted to specific oncogenes have been used with some therapeutic success in animal models of leukemia and melanoma cells and human Hodgkin's lymphoma. We evaluated the effects of antisense ODNs targeted to the bcl-2 oncogene on the proliferation of human renal-cell carcinoma (RCC) cells in vitro and on the growth of human RCC xenografts in BALBc nude (nu/nu) mice.

MATERIALS AND METHODS

Expression bcl-2 mRNA in five RCC cell lines (ACHN, Caki-1, RCZ, RCW, and OS-RC-2) was analyzed by reverse transcriptase-polymerase chain reaction. The effects of phosphorothioated ODNs containing human bcl-2 sense and bcl-2 antisense sequences that were transfected with Lipofectin on the proliferation and viability of cultures of established human RCC cell lines were determined by MTS assay. The expression of Bcl-2 protein in ACHN tumor cells following antisense bcl-2 (AS2) ODN treatment was evaluated by Western blot analysis, and the extent of apoptosis in these cells was determined by fluorescence-activated cell sorter (FACS) analysis. The antitumor activity in ACHN xenografts in nu/nu mice was monitored by measuring differences in tumor weight in treated and control mice.

RESULTS

Expression of bcl-2 mRNA was detected in all five RCC lines. Treatment with antisense bcl-2 ODNs inhibited the growth of all tested RCC cells and decreased Bcl-2 protein expression in ACHN cells. The AS2 antisense ODN complementary to the coding region of bcl-2 mRNA showed a superior antiproliferative effect compared with AS1 ODN complementary to the translation initiation region. Inhibition by antisense bcl-2 ODNs of ACHN cells was dose dependent. The FACS analysis revealed that growth inhibition was associated with the induction of programmed cell death. In vivo, AS2 ODN antitumor activity was noted in locally injected groups.

CONCLUSIONS

Treatment of human RCC with antisense ODNs targeted to bcl-2 inhibits growth and is associated with the induction of programmed cell death. These results suggest therapeutic use of antisense bcl2 in the treatment of RCC.

[Study on analysis of concentration of surfactant PS in injected-produced liquor used in ASP flooding with HPLC]

Ion exchanger and ODS bonded silica gel for HPLC packing were prepared. An HPLC method for the analysis of surfactant PS concentration in injected-produced liquor has been established to meet the need of ASP flooding developed in Gudao West Block of Shengli Oilfield, with a minimum detectable limit of 0.4 mg/L, a linear range of 50 mg/L-1,000 mg/L and recoveries of 95.7%-99.8%. This method has provided great technical support in a variety of fields to the design of the prescription for ASP flooding, the regulation of injection measurement, the quality control of products and the study on the mechanism of oil flooding etc.

[Direct optical resolution of acidic biphenyl drugs by high performance liquid chromatography on tris(3,5-dimethylphenylcarbamate) of cellulose]

A chiral stationary phase was prepared by coating cellulose-tris(3, 5-dimethylphenylcarbamate) onto aminopropylated silica gel. A series of enantiomeric acidic biphenyl drugs were directly resolved on the chiral stationary phase (CSP) by normal-phase high performance liquid chromatography (HPLC). A hexane-2-propanol eluting system containing 1% of trifluoroacetic acid was used as mobile phase. Efficient optical resolution of the acidic biphenyl drugs has been attained. The factors that influence chiral discrimination such as structural characeristic of the samples and mobile phase were investigated. An interaction model between the stationary phase and the samples was discussed. The results showed that efficient optical resolution of racemic carboxylic acids could be attained by normal-phase HPLC on CSP using a hexane-2-propanol eluting system containing 1% of trifluoroacetic acid.

Effect of experimental fasciolosis on antipyrine metabolism and clearance in water buffaloes

The effect of chronic Fasciola hepatica infection on the metabolism of antipyrine, a marker of microsomal oxidative metabolism, was investigated in male water buffaloes dosed daily with 60 F. hepatica metacercariae over 20 days. The plasma elimination half-life of antipyrine was significantly elevated by 23% at 11 weeks postinfection (p.i.) but did not significantly differ from the control period at 20 weeks p.i. The systemic clearance of antipyrine decreased by 48% at 11 weeks p.i. and then returned to normal. The renal clearance for each of the main antipyrine metabolites decreased at 11 weeks p.i. (hydroxymethylantipyrine (HMA), -42%; norantipyrine (NORA), -58%; and 4-hydroxyantipyrine (OHA), -70%) and did not significantly differ from the control period at 20 weeks p.i. These findings indicate that experimental subclinical fasciolosis leads to altered antipyrine kinetics and to an inhibition of the different antipyrine metabolic pathways in water buffaloes.

Relationship between p53 gene mutation and protein expression: clinical significance in transitional cell carcinoma of the bladder

Although the mutated p53 gene has been postulated to induce immunohistochemically-detectable p53 protein, reports regarding the relationship between p53 mutation and p53 protein expression have been contradictory. This study investigated the relationship between p53 mutations and p53 expression and their clinical significance for patients with transitional cell carcinoma of the bladder. Eighty-seven transitional cell carcinoma of the bladder were analyzed by immunohistochemistry (IHC) for p53 nuclear accumulation, and the results compared to mutations detected in the p53 gene evaluated by polymerase chain reaction single-strand conformation polymorphism (SSCP) and DNA sequence analysis. By p53 IHC analysis, positive p53 staining was observed in 50 (57.5%) of the 87 tumors. The specificity of IHC, defined as a percentage of IHC negative (<20%) tumors among tumors without mutation, was 94.6%. Despite the good concordance between p53 mutation and p53 protein expression (p<0.0001), 48.0% (24/50) of the tumors showed p53 overexpression without mutation, and 2 (5.4%) tumors with mutation showed no p53 immunoreactivity. Patients with higher grade (grade 3), stage (stages pT2-4), and p53 mutations had a poorer prognosis by Kaplan-Meier survival analysis. A Cox univariate analysis found that grading (hazard ratio 3.139; p=0.002), staging (hazard ratio 3.832; p=0.0005) and p53 mutation (hazard ratio 2.498; p=0.013) were significant variables in these patients, but no variable was independently associated with an increased survival of bladder carcinoma by multivariate analysis. We found that a 20% cut-off level of p53 overexpression showed the highest correlation with prognosis and p53 mutation, however, p53 overexpression and mutation were not superior to staging as prognostic markers. These data suggest that careful assessment of the TNM staging system remains the most reliable predictive indicator of survival for patients with transitional cell carcinoma of the bladder.

[Chiral separation of glycerin monosulfides and bisulfides with a stationary phase of amylose-tris(3,5-dimethylphenylcarbamate)]

Amylose-tris(3,5-dimethylphenylcarbamate) (ADMPC) and aminopropylated silica gel(APS) were prepared after the reported methods. ADMPC was immobilized on APS from tetrahydrofuran solution with a coating amount of 15%. The chiral stationary phase was packed in a stainless-steel column(150 mm x 4.6 mm i.d.) by slurry method. The column was used for the enantioseparation of 6 glycerin monosulfides and 4 glycerin bisulfides. Mixtures of hexane and 2-propanol were used as mobile phases. The enantiomers of the monosulfides could be separated quite well, while those of the bisulfides could not at all. This phenomenon shows that the ether oxygen atom of the monosulfides plays a key role in the chiral discrimination process. The retention time of the solutes increases significantly as the amount of 2-propanol decreases. This shows the main interaction between the solutes and the chiral stationary phase is hydrogen bonding. A dynamic model is presented to account for the chiral discrimination mechanism.

The significance of frequent and independent p53 and bcl-2 expression in large-cell neuroendocrine carcinomas of the lung

Both p53 and bcl-2 genes are involved in regulating cell death. Reports, however, concerning the relationship between p53 and bcl-2 expression are contradictory. Large-cell neuroendocrine carcinoma (LCNEC) of the lung is a newly recognized clinicopathologic entity. p53 mutation and bcl-2 overexpression are frequent in small-cell lung carcinoma (SCLC), and we observed a close correlation between bcl-2 expression and cellular neuroendocrine (NE) differentiation in non-SCLC, so we speculated that LCNEC, an NE tumor closely related to SCLC, would exhibit high incidence of both p53 alteration and bcl-2 expression. Immunohistochemical expression of p53 and bcl-2 was evaluated on consecutive sections of 26 LCNECs, including 4 combined LCNECs. p53 accumulation and diffuse bcl-2 staining were observed in 18 (69.2%) of 26 and 24 (92.3%) of 26 LCNECs, respectively, but their immunoreactivities showed no fixed distribution relevance on consecutive sections in individual tumors. Statistical analyses yielded no relationship between p53 and bcl-2 expression (P = .47). In all of the four combined LCNECs, p53 was identically either positive or negative in both tumor cell populations with and without NE differentiation. bcl-2 immunoreactivity was observed only for the tumor cells with NE phenotype in three of the four combined LCNECs and was diffuse among the NE tumor cells but geographic in distribution among the non-NE tumor cells of the remaining one combined LCNEC. Thus, our present findings suggest that p53 and bcl-2 are expressed independently and might have distinct expression significance in LCNECs. A high incidence of p53 expression in LCNECs and equal p53 expression profiles in NE and non-NE tumor cell populations of combined LCNECs suggest that p53 alteration is primarily involved in the tumorigenesis of LCNEC. On the other hand, frequent bcl-2 expression in pure LCNECs and selective bcl-2 expression in tumor cells with NE phenotype in combined LCNECs are suggestive of a role for bcl-2 in regulating cellular NE differentiation.

Tumor extension and cell proliferation in adenocarcinomas of the lung

To elucidate the mechanism of tumor extension in human pulmonary adenocarcinoma, we immunohistochemically investigated the expression of cell cycle regulator proteins in 54 small adenocarcinomas less than 3 cm in diameter. The Ki-67-labeling index was significantly higher in the periphery of the tumor nodule than in the center. This proliferative potential correlated well with coexpression of cdk2 and cyclin A. p27, one of the cdk inhibitors, was highly expressed in normal bronchial epithelial cells. Peripherally located tumor cells expressed p27 at an intermediate level, but at a higher frequency and level than those in the center. Expression of p21 was also predominant in the periphery. Furthermore, the expression patterns of p21 and p27 were reciprocal. In vitro kinase assays further demonstrated higher cdk2 kinase activity in the periphery. These results suggest that: (i) within an emerging extension made up of peripherally located tumor cells, their high proliferative potential gradually wanes as their relative topographical position becomes more central in the expanding tumor; (ii) peripherally located tumor cells maintain their proliferative potential by higher cyclin A-cdk2 complex activity; and (iii) intermediate expression of p21/p27 in the peripherally located cells promotes higher cyclin A-cdk2 kinase activity, whereas high p21/p27 expression in nonneoplastic cells inhibits kinase activity.

Active cyclin A-CDK2 complex, a possible critical factor for cell proliferation in human primary lung carcinomas

Expression of cyclins A and E and cyclin-dependent kinase 2 (CDK2) was examined immunohistochemically in 190 cases of human lung carcinoma. Cyclin A and CDK2 were expressed in the majority of squamous cell carcinomas, small cell carcinomas, and large cell carcinomas, but in significantly fewer cases of adenocarcinomas. Cyclin E was expressed in a minority of all subtypes. In particular, well differentiated cells in squamous cell carcinoma stained positively for cyclin E; in contrast, cyclin A was expressed in the nonkeratinized proliferating areas of the tumor nests. Immunoblotting revealed that all these proteins were expressed at higher levels in tumor tissues than in adjacent normal tissues. Immunoprecipitation also revealed higher levels of cyclin A and cyclin E associated with CDK2 in tumor tissues. Furthermore, tumor tissues which exhibited higher cyclin A and CDK2 expression also had higher CDK2 kinase activity. However, cyclin E-associated kinase activity was barely detectable even in tumor samples exhibiting higher cyclin E expression. Consistent with these data, elevated expression of cyclin A correlated to shorter survival periods in contrast to expression of cyclin E, which correlated to longer survival periods. These results suggest that in human lung carcinomas, elevated expression of active cyclin A-CDK2 complexes with associated higher CDK2 kinase activity is critical for promoting cell cycle progression and unrestrained proliferation of tumor cells and can be a predictive marker for patients' prognosis. On the other hand, immunohistochemical detection of cyclin E-CDK2 reflects accumulation of inactive forms of protein complexes, implying differentiation or senescence of the tumor and the better prognosis.

Large cell neuroendocrine carcinoma of the lung: a histologic and immunohistochemical study of 22 cases

Large cell neuroendocrine carcinoma (LCNEC) of the lung is defined as a poorly differentiated and high-grade neuroendocrine tumor that is morphologically and biologically between atypical carcinoid and small cell lung carcinoma (SCLC). During a survey concerning bcl-2 protein expression in the subtypes of lung cancer, we noticed that two previously diagnosed non-SCLCs met the criteria for LCNEC. Because LCNEC is a newly recognized clinicopathologic entity and because all reported cases have been retrieved from the so-called "neuroendocrine tumor file," we suspected that LCNEC had been underdiagnosed. In the present study, we histologically reviewed 766 surgically resected lung cancers and were able to diagnose 22 (2.87%) LCNECs with the neuroendocrine features subsequently confirmed by immunostaining for multiple neuroendocrine markers. Each case stained positively for at least three general neuroendocrine markers, and 12 (54.5%) also were positive for neuroendocrine hormones. Histologically, most LCNECs showed a marked decrease in or a loss of organoid architecture and could be mistaken for poorly differentiated adenocarcinoma or squamous cell carcinoma. Because our LCNECs are the first to be identified by retrospective review of routinely diagnosed lung cancers, and 18 had been classified as non-SCLC, they may represent cases relatively difficult to diagnose. The present study shows that the most difficult diagnostic factor of LCNEC is the recognition of its light microscopic neuroendocrine features, and LCNEC must be distinguished not only from atypical carcinoid or SCLC, but also from common non-SCLC. Histologically, when an organoid architecture is subtle or absent, the rosettelike structure becomes the best marker for the recognition of neuroendocrine differentiation. Clinically, the prognosis for our LCNECs was significantly worse than that for stage-comparable non-SCLCs (p = 0.046).

Bcl-2 protein expression in lung cancer and close correlation with neuroendocrine differentiation

For determination of the cellular distribution of bcl-2 expression in lung cancer and clarification of its correlation with cell neuroendocrine differentiation, Bcl-2 immunostaining was carried out on a large series of formalin-fixed, paraffin-embedded lung cancer samples, and four general neuroendocrine marker and seven peptide hormone stainings were carried out on all Bcl-2-positive squamous cell carcinomas and adenocarcinomas of the lung as well as on 8 pulmonary neuroendocrine carcinomas histologically diagnosed. In addition, 3 small cell lung cancer cell lines were studied by Western blotting. Neuroendocrine differentiation in Bcl-2-negative squamous cell carcinomas and adenocarcinomas was examined with chromogranin A and alpha-subunit of Go protein stainings. Bcl-2 protein was detected in 104/111 small cell carcinomas, 8/8 neuroendocrine carcinomas, 0/6 typical (well differentiated) carcinoids, 23/64 squamous cell carcinomas, 4/65 adenocarcinomas, and all 3 small cell lung cancer cell lines. All 8 neuroendocrine carcinomas, 11 of the Bcl-2-positive squamous cell carcinomas, and all 4 Bcl-2 positive adenocarcinomas expressed multiple neuroendocrine markers. The distributions of Bcl-2 and neuroendocrine marker immunoreactivity closely paralleled each other on consecutive sections. In squamous cell carcinomas, Bcl-2-positive cells could be roughly subdivided into those with neuroendocrine differentiation features, usually demonstrating intense Bcl-2 staining, with basaloid tumor cells usually expressing weak to moderate Bcl-2 staining. The present study clearly shows Bcl-2 protein expression to be remarkably differentially regulated according to histological types of lung cancers and to appear to quite likely be closely associated with neuroendocrine differentiation of tumor cells, indicating that bcl-2 is importantly involved in cell development and differentiation, in addition to protecting cells from apoptosis. Bcl-2 might be usable as a neuroendocrine marker in lung cancers and possibly also in neural-crest-derived tumors.

Expression of bcl-2 oncogene protein is prevalent in small cell lung carcinomas

To investigate the frequency of bcl-2 oncogene protein expression in small cell lung carcinoma (SCLC), immunohistochemical staining with a mouse-anti-human monoclonal antibody, bcl-2/124, was carried out on 60 formalin-fixed, paraffin-embedded SCLC samples obtained from surgical biopsy, and autopsy cases. bcl-2 protein was detected in 54 out of the 60 SCLCs. In 47 cases, more than half of the tumour cells stained positively. The staining intensity of the tumour cells was comparable to that of infiltrating lymphocytes in 37 cases, but varied from area to area and even from cell to cell. Negative data in six cases were found to be due to unsuitable fixation or embedding procedures rather than the absence of the antigen. bcl-2 oncogene protein may thus be expressed in most if not all SCLCs. bcl-2 may have potential diagnostic and therapeutic importance in SCLCs and non-SCLCs. Previous cytogenetic and molecular genetic analyses indicate that SCLCs carry a number of chromosomal abnormalities and it would follow from the present results that the abnormal expression of bcl-2 may also play a role in the pathogenesis of SCLC, by increasing tumour mass through inhibition of apoptosis as previously proposed. The diagnostic, prognostic, and therapeutic implications of these findings should be studied in greater detail.

Effects of the stem cell factor, c-kit ligand, on human megakaryocytic cells

The kit ligand (KL), also termed stem cell factor (SCF), is a recently discovered hematopoietic growth factor that augments response of early progenitor cells to other growth factors and supports proliferation of continuous mast cell lines. Histological studies suggest that the receptor for SCF/KL, the c-kit proto-oncogene product, is present in bone marrow megakaryocytes. We studied the effects of SCF/KL on immortalized human megakaryocytic cell lines (CMK, CMK6, and CMK11-5) and on isolated human marrow megakaryocytes. Human SCF/KL alone or in combination with the hematopoietic growth factors, interleukin-3 (IL-3), granulocyte-macrophage colony-stimulating factor (GM-CSF), and IL-6, stimulated proliferation of these megakaryocytic cell lines. SCF/KL treatment did not alter expression of gpIb, gpIIb/IIIa, LFA-1, ICAM-1, or GMP-140 in CMK cells. No effect on ploidy was observed. Furthermore, human SCF/KL induced expression of IL-1 alpha, IL-1 beta, IL-2, and IL-6 in CMK cells. In a fibrin clot system, SCF/KL modestly potentiated megakaryocyte colony formation when added alone to cultures containing CD34+, DR+ bone marrow cells. Addition of SCF/KL with IL-3 or GM-CSF to these cultures resulted in a more marked marrow megakaryocytic cells. SCF/KL may directly affect megakaryocytopoiesis, as well as secondarily modulate hematopoiesis through induction of cytokines in target cells.

[A study on the cellular heterogeneity of lung carcinoma]

The cellular heterogeneity and histological origin of 28 cases of lung carcinoma were studied by light and electron microscopy, as well as by immunohistochemical technique. Most and possibly all of the lung carcinomas were heterogeneous. In 5 of these cases, dual-differentiation in individual cells was revealed. It seems that various types of primary lung carcinoma, including small cell carcinoma, have the same histogenesis. Neuro-endocrine differentiation is not only seen in the typical small cell carcinoma, but is also seen in other types of lung carcinoma.

[Studies on endotoxin of Leptospira. V. The effect of EDTA-Na on the release of the LPS of Leptospira interrogans serovar lai]

The yield of leptospiral LPS was able to increase 1-2 times when the cells were treated with EDTA-Na before extracting with hot phenal-water method. The colours and solubility of L-LPS were improved. When the leptospiral cells were stored for a long period of time, and treated by EDTA-Na, the phase distribution of the LPS changed, i.e. they returned from water phase into phenol phase. Such change was related to the quantity of both the saccharide and lipid.

Limited proteolysis of 3-phosphoglycerate kinase without loss of enzymic activity

During tryptic digestion of pig muscle 3-phosphoglycerate kinase in the presence of 3-phosphoglycerate both the decrease of enzymic activity and the release of trichloroacetic acid-soluble peptides occur after a pronounced lag period. During this lag phase the native enzyme molecule is split into two fragments with molecular masses of about 30 and 18 kDa, as detected by SDS-PAGE. Under non-denaturing conditions, however, these fragments are held together by non-covalent forces and constitute an active, nicked enzyme molecule. In the absence of substrates or in the presence of MgATP the kinetics of tryptic digestion is apparently a single first order reaction leading to the formation of peptides with molecular masses of less than 10 kDa.