Follow-Up Biopsies in Gastrointestinal Immune Checkpoint Inhibitor Toxicity May Show Markedly Different Inflammatory Patterns Than Initial Injury

Colitis is a common manifestation of immune checkpoint inhibitor (ICI) toxicity and can present with varied histologic patterns of inflammation, some of which have been shown to be associated with specific ICI drug types. Although the histologic features of ICI colitis seen at the time of diagnosis have been described, there have been few reports following these patients over time. We evaluated initial and follow-up biopsies in 30 patients with ICI colitis and found that 37% of patients developed a different pattern of injury on follow-up biopsy compared to the initial biopsy. Patients with a different inflammatory pattern were more likely to have restarted ICI therapy before their follow-up biopsy (64%) compared to those without a change in inflammatory pattern (11%; P < 0.01). The majority of these patients had changed ICI drug types (86%). Additionally, many cases changed to an inflammatory bowel disease (IBD)-like pattern (36%), raising a question of de novo IBD. However, all of our patients with an IBD-like pattern experienced sustained resolution of symptoms without steroids or other immunosuppressive medications following discontinuation of ICI therapy, consistent with a diagnosis of ICI toxicity. Our findings suggest that follow-up biopsies in patients with ICI colitis may show a different histology and that this does not necessarily warrant a change in the histologic diagnosis to another disease.

A Phase I Trial of Focal Salvage Stereotactic Body Radiation Therapy for Radiorecurrent Prostate Cancer

PURPOSE/OBJECTIVE(S)

Locally recurrent prostate cancer after radiotherapy (RT) is an increasingly recognized entity with no standard management. NCT03253744 was a phase I trial with a primary objective of identifying the maximally tolerated dose (MTD) of a course of image-guided, focal, salvage stereotactic body radiotherapy (SBRT) for patients with local recurrence after prior definitive RT. Additional objectives included biochemical control and imaging response on mpMRI and 18F-DCFPyL (PSMA) PET/CT.

MATERIALS/METHODS

SBRT was prescribed to three dose levels (DLs): 40Gy (DL1), 42.5Gy (DL2), and 45Gy (DL3) in 5 fractions. The prescription dose was delivered to a PTV defined by mpMRI and PSMA imaging and biopsy confirmed tumor volume. Dose escalation followed a 3+3 design with a 3-patient expansion at the MTD. Toxicities above baseline were scored using CTCAE v5.0 criteria for two years after completion of SBRT. Escalation was halted if 2 dose limiting toxicities (DLTs) were observed. DLTs were defined as any persistent (>4 days) grade 3 toxicity occurring within the first 3 weeks after SBRT, and any grade 3 GU or grade 4 GI toxicity thereafter. Imaging response was compared between baseline and 6-months by the Wilcoxon signed rank test.

RESULTS

Between 08/2018 and 05/2022, 8 patients underwent salvage SBRT to 11 intraprostatic lesions with a median follow-up of 27 months. No DLTs were observed on DL1. Two patients were enrolled on DL2 and both experienced grade 3 GU toxicities, prompting de-escalation and expansion (n = 6) on DL1, the MTD. The most common toxicities were grade 2 GU toxicities: acute urinary urgency/frequency, acute weak urinary stream, and noninfective cystitis. One patient at DL1 had a self-limited episode of grade 2 GI toxicity (proctitis). No grade 3 GI toxicities were observed. All but two patients achieved an undetectable PSA nadir. Only one of these experienced biochemical failure (nadir + 2.0) at 33 months with suspicion of distant metastatic failure on restaging PET/CT. Imaging response was demonstrated by MRI in all lesions with heterogeneity in volumetric response (6% to 100%). A significant (p<0.01) response on PSMA PET/CT was observed for all measured parameters (SUVMax, SUVMean, GTVPSMA, Total Lesion PSMA [SUVMean × GTVPSMA]). Of the 11 lesions, 1 (9%) demonstrated a complete response (CR) by MRI and 9 (82%) by PSMA PET/CT. A single lesion increased in volume by 0.06 cc (16%) at 6-month PSMA PET/CT compared to baseline in the only patient who did not achieve an undetectable PSA nadir and did not have imaging suggestive of distant failure.

CONCLUSION

On this phase I dose escalation study of salvage SBRT for isolated intraprostatic local failure after definitive RT, the MTD was 40Gy in 5 fractions. producing a 100% 24-month bPFS, with one late failure at 33 months occurring after the 24-month study period. The most frequent clinically significant toxicity was late grade 2 GU toxicity. Imaging response was demonstrated in all lesions on MRI and PSMA PET/CT with exception of a single lesion.

Computational pathology in 2030: a Delphi study forecasting the role of AI in pathology within the next decade

BACKGROUND

Artificial intelligence (AI) is rapidly fuelling a fundamental transformation in the practice of pathology. However, clinical integration remains challenging, with no AI algorithms to date in routine adoption within typical anatomic pathology (AP) laboratories. This survey gathered current expert perspectives and expectations regarding the role of AI in AP from those with first-hand computational pathology and AI experience.

METHODS

Perspectives were solicited using the Delphi method from 24 subject matter experts between December 2020 and February 2021 regarding the anticipated role of AI in pathology by the year 2030. The study consisted of three consecutive rounds: 1) an open-ended, free response questionnaire generating a list of survey items; 2) a Likert-scale survey scored by experts and analysed for consensus; and 3) a repeat survey of items not reaching consensus to obtain further expert consensus.

FINDINGS

Consensus opinions were reached on 141 of 180 survey items (78.3%). Experts agreed that AI would be routinely and impactfully used within AP laboratory and pathologist clinical workflows by 2030. High consensus was reached on 100 items across nine categories encompassing the impact of AI on (1) pathology key performance indicators (KPIs) and (2) the pathology workforce and specific tasks performed by (3) pathologists and (4) AP lab technicians, as well as (5) specific AI applications and their likelihood of routine use by 2030, (6) AI's role in integrated diagnostics, (7) pathology tasks likely to be fully automated using AI, and (8) regulatory/legal and (9) ethical aspects of AI integration in pathology.

INTERPRETATION

This systematic consensus study details the expected short-to-mid-term impact of AI on pathology practice. These findings provide timely and relevant information regarding future care delivery in pathology and raise key practical, ethical, and legal challenges that must be addressed prior to AI's successful clinical implementation.

FUNDING

No specific funding was provided for this study.

Challenges in the Development, Deployment, and Regulation of Artificial Intelligence in Anatomic Pathology

Significant advances in artificial intelligence (AI), deep learning, and other machine-learning approaches have been made in recent years, with applications found in almost every industry, including health care. AI has proved to be capable of completing a spectrum of mundane to complex medically oriented tasks previously performed only by boarded physicians, most recently assisting with the detection of cancers difficult to find on histopathology slides. Although computers will not replace pathologists any time soon, properly designed AI-based tools hold great potential for increasing workflow efficiency and diagnostic accuracy in the practice of pathology. Recent trends, such as data augmentation, crowdsourcing for generating annotated data sets, and unsupervised learning with molecular and/or clinical outcomes versus human diagnoses as a source of ground truth, are eliminating the direct role of pathologists in algorithm development. Proper integration of AI-based systems into anatomic-pathology practice will necessarily require fully digital imaging platforms, an overhaul of legacy information-technology infrastructures, modification of laboratory/pathologist workflows, appropriate reimbursement/cost-offsetting models, and ultimately, the active participation of pathologists to encourage buy-in and oversight. Regulations tailored to the nature and limitations of AI are currently in development and, when instituted, are expected to promote safe and effective use. This review addresses the challenges in AI development, deployment, and regulation to be overcome prior to its widespread adoption in anatomic pathology.

Nodal ratio of positive to excised nodes, but not number of positive lymph nodes is better to predict group to avoid chemotherapy among postmenopausal ER-positive, lymph node-positive T1-T2 breast cancer patients

AIM OF STUDY

To identify whether nodal ratio (NR) of positive to excised nodes is superior to number of positive lymph nodes to predict group to avoid chemotherapy among postmenopausal ER-positive, lymph node-positive, T1-T2 breast cancer patients.

MATERIALS AND METHODS

Postmenopausal estrogen receptor (ER)-positive, lymph node-positive patients who received endocrine therapy (n = 173) with complete baseline data in our hospital between 2000 and 2006 were included. The disease-free survival (DFS) was compared. Survival analysis was performed using Kaplan-Meier method. Cox proportional hazard models were used to evaluate the prognostic value of chemotherapy with different NR for DFS. P--values less than 0.05 were regarded as significant.

RESULTS

The median follow-up was 72 months. Three of 13 variables analyzed remained significantly prognostic for survival in the Cox proportional hazards model. These included age (hazard ratio (HR) =1.642, 95% confidence interval (CI) =1.154-2.337, P = 0.006); histological grade (HR = 2.463,95% CI = 1.389-4.367, P = 0.002); and NR (HR = 2.280, 95% CI = 1.113-4.671, P = 0.024). Subgroup analysis by NR status showed that in patients with NR ≥ 0.20, chemotherapy significantly improves DFS (HR = 0.360, 95% CI = 0.195-0.663, P = 0.001); while in patients with NR < 0.20, chemotherapy did not significantly affect DFS (HR = 0.677, 95% CI = 0.227-2.107, P = 0.493). Radiotherapy is an important factor that improves DFS in lymph node-positive patients, so it is considered in all analysis.

CONCLUSION

This retrospective analysis demonstrates that NR of positive to excised nodes, but not number of positive lymph nodes is better to predict group to avoid chemotherapy among postmenopausal ER-positive, lymph node-positive T1-T2 breast cancer patients.

Insomnia symptoms in South Florida military veterans with epilepsy

BACKGROUND

Despite the high prevalence of insomnia in veterans with epilepsy, it remains understudied. Our aim was to identify the associations of insomnia with epilepsy, comorbidities, and treatment-related variables in South Florida veterans.

METHODS

We performed a cross-sectional analysis of veterans attending an epilepsy clinic over 18 months. Participants completed standardized assessments of seizure and sleep. Insomnia was defined as 1) difficulty with sleep onset, maintenance, or premature awakenings with daytime consequences or 2) sedative-hypnotic use on most nights of the previous month.

RESULTS

One hundred sixty-five veterans (87% male, age 56 ± 15 years) were included: 66 reporting insomnia (40%). In logistic regression analysis, insomnia was significantly associated with post-traumatic seizure etiology, lamotrigine prescription, and mood and psychotic disorders. Female gender and levetiracetam treatment were associated with lower odds for insomnia.

CONCLUSION

Insomnia was associated with post-traumatic epilepsy, mood/psychotic comorbidities, and antiepileptic regimen. Insomnia represents an under-recognized opportunity to improve comprehensive epilepsy care.

Spatially Invariant Vector Quantization: A pattern matching algorithm for multiple classes of image subject matter including pathology

Introduction:

Historically, effective clinical utilization of image analysis and pattern recognition algorithms in pathology has been hampered by two critical limitations: 1) the availability of digital whole slide imagery data sets and 2) a relative domain knowledge deficit in terms of application of such algorithms, on the part of practicing pathologists. With the advent of the recent and rapid adoption of whole slide imaging solutions, the former limitation has been largely resolved. However, with the expectation that it is unlikely for the general cohort of contemporary pathologists to gain advanced image analysis skills in the short term, the latter problem remains, thus underscoring the need for a class of algorithm that has the concurrent properties of image domain (or organ system) independence and extreme ease of use, without the need for specialized training or expertise.

Results:

In this report, we present a novel, general case pattern recognition algorithm, Spatially Invariant Vector Quantization (SIVQ), that overcomes the aforementioned knowledge deficit. Fundamentally based on conventional Vector Quantization (VQ) pattern recognition approaches, SIVQ gains its superior performance and essentially zero-training workflow model from its use of ring vectors, which exhibit continuous symmetry, as opposed to square or rectangular vectors, which do not. By use of the stochastic matching properties inherent in continuous symmetry, a single ring vector can exhibit as much as a millionfold improvement in matching possibilities, as opposed to conventional VQ vectors. SIVQ was utilized to demonstrate rapid and highly precise pattern recognition capability in a broad range of gross and microscopic use-case settings.

Conclusion:

With the performance of SIVQ observed thus far, we find evidence that indeed there exist classes of image analysis/pattern recognition algorithms suitable for deployment in settings where pathologists alone can effectively incorporate their use into clinical workflow, as a turnkey solution. We anticipate that SIVQ, and other related class-independent pattern recognition algorithms, will become part of the overall armamentarium of digital image analysis approaches that are immediately available to practicing pathologists, without the need for the immediate availability of an image analysis expert.

Computational hydrodynamics of animal swimming: boundary element method and three-dimensional vortex wake structure

The slender body theory, lifting surface theories, and more recently panel methods and Navier-Stokes solvers have been used to study the hydrodynamics of fish swimming. This paper presents progress on swimming hydrodynamics using a boundary integral equation method (or boundary element method) based on potential flow model. The unsteady three-dimensional BEM code 3DynaFS that we developed and used is able to model realistic body geometries, arbitrary movements, and resulting wake evolution. Pressure distribution over the body surface, vorticity in the wake, and the velocity field around the body can be computed. The structure and dynamic behavior of the vortex wakes generated by the swimming body are responsible for the underlying fluid dynamic mechanisms to realize the high-efficiency propulsion and high-agility maneuvering. Three-dimensional vortex wake structures are not well known, although two-dimensional structures termed 'reverse Karman Vortex Street' have been observed and studied. In this paper, simulations about a swimming saithe (Pollachius virens) using our BEM code have demonstrated that undulatory swimming reduces three-dimensional effects due to substantially weakened tail tip vortex, resulting in a reverse Karman Vortex Street as the major flow pattern in the three-dimensional wake of an undulating swimming fish.

Adenovirus-Mediated MUC1 gene transduction into human blood-derived dendritic cells

MUC1 protein is widely expressed on various human cancer cells and has a specific highly glycosylated core structure with multiple tandem repeats, which may include an immunogenic peptide sequence. The potency of MUC1 protein to induce human histocompatibility leukocyte antigen-class I-restricted cytotoxic T-lymphocyte (CTL) induction remains to be fully clarified in human beings. In the current study, we made MUC1-expressing human dendritic cells (DCs) using recombinant adenovirus vector. Adenovirus vector plasmid containing human MUC1 cDNA, pAdHM4-MUC1 was constructed using in vitro ligation with a shuttle vector, pHMCMV5. Adenovirus vector expressing MUC1 was generated by the transfection of PacI-digested recombinant vector plasmid into 293 cells. Human blood DCs were obtained from 7-day culture of monocytes with recombinant human (rh) granulocyte-macrophage (GM) colony-stimulating factor (CSF) and (rh)interleukin (IL)-4. Then, 1 x 10(6) DCs were incubated with viral supernatant at a multiplicity of infection of 200 for 24 h in the presence of rhGM-CSF and rhIL-4. Flow cytometric analysis showed that 30% to 40% of the transduced DCs expressed MUC I protein; by contrast, nontransduced or transduced DCs with mock virus expressed only small amounts of MUC1 protein. Adenovirus-mediated MUC1 gene transduction into DCs had no significant effect on DC surface marker expressions or functions such as mixed leukocyte reaction. Furthermore, MUCI-specific CD8+ CTLs could be induced from healthy donor blood lymphocytes using MUC1-expressing DCs as stimulators. These results suggested that MUC1 gene-transduced DCs are a functional and potent tool for triggering a CTL response against MUC1 cancer cells.

Height and weight change across menarche of schoolgirls with early menarche

OBJECTIVE

To describe growth before and after menarche.

DESIGN

Nine hundred five fourth grade school girls were identified as a closed cohort from the first semester of 1993 for the observational study of the onset of menarche and its predictive factors.

SETTINGS

Eight elementary schools in Taipei City and Taipei County, Taiwan.

MAIN OUTCOME MEASURES

Data were collected from self-administered questionnaires and school records. Height and weight were measured in September, January, February, and June, or only in September and February of each year.

RESULTS

All subjects remained in the cohort until sixth grade, 410 of whom had their first menstruation before graduating from elementary school. Height, weight, and body mass index (calculated as weight in kilograms divided by the square of height in meters) at each time point were plotted against 2 time scales: chronological age and time from the onset of menarche. Growth velocity of height and weight across the onset of menarche was assessed with slope change using the mixed-effect model analysis.

CONCLUSIONS

The results support the hypothesis that height velocity reaches a peak 1 year before menarche but height velocity stopped increasing within 1 year after menarche. The change in weight velocity reveals no obvious growth spurt at age of menarcheal onset.

Molecular defects in variant forms of mannose-binding protein associated with immunodeficiency

Distinct molecular mechanisms underlying immunodeficiency caused by three different naturally occurring point mutations within the collagen-like domain of human mannose-binding protein (MBP; also known as mannose-binding lectin) have been revealed by introduction of analogous mutations into rat serum MBP. The change Arg23-->Cys results in a lower proportion of the large oligomers most efficient at activating the complement cascade. The presence of cysteine at position 23, which forms aberrant interchain disulfide bonds, causes disruption of the normal oligomeric state. The deficiency in MBPs containing Gly25-->Asp and Gly28-->Glu substitutions also results in part from reduced formation of higher oligomers. However, decreased ability to interact with downstream components of the complement cascade due to changes in both the N-terminal disulfide-bonding arrangement and the local structure of the collagenous domain make more important contributions to the loss of activity in these mutants.

Epstein-Barr virus LMP1 modulates the malignant potential of gastric carcinoma cells involving apoptosis

About 10% of gastric carcinomas including lymphoepithelioma-like carcinoma and adenocarcinoma are associated with Epstein-Barr virus (EBV) infection. In EBV-associated gastric carcinomas, the tumor cells express Epstein-Barr nuclear antigen 1 (EBNA-1) but not EBNA-2, -3A, -3B, or -3C, leader protein, or latent membrane proteins (LMPs) because of gene methylation. Only a few exceptional cases have LMP1 expression in tumor cells as demonstrated by immunohistochemical studies. To elucidate the biological effects of LMP1 and the significance of its restricted expression in EBV-associated gastric carcinomas, the LMP1 gene was transferred into EBV-negative gastric carcinoma cell lines (SCM1 and TMC1) and into EBV-negative nasopharyngeal carcinoma (NPC) cells (HONE-1) as a control. The biological effects of LMP1 in gastric carcinoma cells were monitored in vitro and in vivo. These results showed that the consequence of LMP1 expression is a growth enhancement in NPC cells, but it is a growth suppression in gastric carcinoma cells. The LMP1-expressing gastric carcinoma cells had a reduced growth rate, colony-forming efficiency, mean colony size, and tumorigenicity and a lower malignant cytological grade. The reduced growth rate, colony-forming efficiency, and mean colony size were partially reversible in vitro with treatment with LMP1 antisense oligonucleotide. In addition, enhanced apoptosis was found in the LMP1-expressing gastric carcinoma cells. This suggests that LMP1 may negatively modulate the malignant potential of gastric carcinoma cells via an enhancement of apoptosis. We concluded that the restriction of LMP1 expression in EBV-associated gastric carcinomas may lead to a growth advantage for tumor cells by avoiding LMP1 apoptotic effects and immunologically mediated elimination.

Expression of p53 protein in colorectal carcinoids

OBJECTIVE

To determine the frequency and prognostic significance of p53 protein expression in colorectal carcinoid tumors.

DESIGN

Thirty-one paraffin-embedded specimens of colorectal carcinoid tumor were studied by immunohistochemical staining to detect p53 protein expression. The association of p53 expression with tumor site, tumor size, invasion level, tumor stage, DNA pattern, and patient survival were analyzed.

RESULTS

p53 protein was detected in five (16%) of 31 colorectal carcinoid tumors. There was a correlation between p53 overexpression and tumor site, tumor size, tumor stage, and DNA ploidy (P < .05) but not for the depth of tumor invasion (P = .06). In addition to tumor size, invasion, stage, and DNA aneuploidy, p53 protein overexpression was also indicative of a poor prognosis (P < .001).

CONCLUSIONS

The overexpression of p53 protein is uncommon in colorectal carcinoid tumors. However, the expression of p53 protein has a correlation with clinicopathologic-predicting criteria in colorectal carcinoid tumors and may be used as an associated prognostic parameter to assess patient survival.

Detection of human papillomavirus DNA in colorectal carcinomas by polymerase chain reaction

Human papillomaviruses (HPVs) are associated with a number of benign and malignant neoplasms. To substantiate the relationship between HPV DNA and colorectal carcinomas, 70 carcinomas and 37 adenomas were analysed in this study. Specific types of HPV DNA in colorectal tumours were detected by polymerase chain reaction (PCR) and Southern blot hybridisation. HPV DNA was detected in 11 of 37 (29.7%) adenomas and in 52.9% 37 of 70 (52.9%) of carcinomas. The expression of HPV DNA in adenomas and carcinomas, especially that of HPV 16 in HPV positive cases (4 of 11 v 26 of 37), was significantly different (p < 0.05). There was no correlation, however, between HPV and the location, differentiation, stage, or survival of malignant neoplasms. These data suggest that HPV DNA, especially type 16, is associated with colorectal carcinogenesis.

Optimal dose of garlic to inhibit dimethylhydrazine-induced colon cancer

This study was designed to investigate the optimal dose of garlic during long-term feeding and its preventive and therapeutic effects on colon cancer in rats induced by 1,2-dimethylhydrazine (DMH). A total of 240 male Sprague-Dawley rats were grouped and fed with either a basal or a garlic diet of different concentration, and some groups were subcutaneously injected with DMH 20 mg/kg once a week for 20 weeks. The incidence of colon tumor was significantly decreased in the groups fed with 2.5%, 5%, and 10% garlic diets (p < 0.001). There was no distinct difference among these concentrations (p > 0.05). Therefore the minimal optimal dose of garlic to inhibit colon cancer was 2.5%. The equivalent dose of this concentration in humans is 4.76 g/m2 body surface/day. In a therapeutic study, the tumor-inducing interval in nude mice subcutaneously injected with colon cancer cells (CC-M2) was prolonged by a 2.5% garlic diet (p < 0.01). Thus smaller tumor volume and longer survival time were found in the garlic group than in the controls (p < 0.01). However, the growth rate of tumors was not markedly inhibited by garlic. All rats finally died within 18 weeks. This study suggested that a 2.5% garlic dose may be used mainly as an inhibitor to prevent colon cancers and improve survival time.

Detection of human papillomavirus DNA in colorectal adenomas

OBJECTIVE

To assess the presence of different types of human papillomavirus (HPV) DNA in colorectal adenomas.

DESIGN

The extracted DNA of 109 formalin-fixed, paraffin-embedded tissue sections of colorectal adenomas were analyzed by polymerase chain reaction and Southern blot hybridization. The correlations of HPV types 6, 11, 16, 18, and 33 DNA with the histological patterns of adenomas were also analyzed.

RESULTS

Human papillomavirus DNA was detected in 28% of the adenomas. There were eight (21%) of 38 in tubular adenomas, 13 (33%) of 40 in tubulovillous adenomas, and 10 (32%) of 31 in villous adenomas. All HPV-6/11-positive cases were tubular or tubulovillous adenomas. However, most HPV-16 infections (8/12) were seen in villous adenomas. Human papillomavirus-positive adenomas included three (8%) of 38 that showed mild dysplasia, 10 (25%) of 40 that showed moderate dysplasia, and 18 (58%) of 31 that showed severe dysplasia.

CONCLUSION

The association of the histological type with HPV-16 and the association of the grade of epithelial dysplasia with HPV DNA were highly significant. These associations support the adenoma-carcinoma hypothesis. In addition, the results suggest that HPV infection may be an important factor for the development of colorectal neoplasia.

Flow cytometric DNA analysis of colorectal carcinoid

We analyzed the patterns of DNA ploidy in 31 colorectal carcinoid tumors from paraffin-embedded tissues by DNA flow cytometry and the relationship of the patterns of DNA ploidy to prognosis. Diploid DNA was found in 78% (24 of 31) of carcinoids and tetraploid in 6% (2 of 31). Five (16%) carcinoids were DNA aneuploid, and four of the patients with aneuploidy showing a near-hypertriploid pattern died during the first 5 years of follow-up. The association of aneuploidy with stage, size, and invasion of tumor was significant. However, our data indicated that DNA aneuploidy of a near-hypertriploid pattern was the most precise and reliable parameter for predicting the prognosis of colorectal carcinoid tumors.

NOTE ON THE CALCULATION OF PROPELLER EFFICIENCY USING ELONGATED BODY THEORY

The elongated body theory has been widely used for calculations of the hydrodynamic propulsive performance of swimming fish. In the biological literature, terms containing the slope of the amplitude function at the tail end have been neglected in the calculations of thrust and efficiency, and a slope of zero has been assumed. However, some fishes, such as saithe and trout, have non-zero values of the slope near the tail end and, when this term is taken into account, the efficiency may be reduced by as much as 20 % and approaches the result given by the three-dimensional waving plate theory. The inclusion of the slope in the efficiency considerations results in an optimum ratio of the swimming speed to the wave speed that is clearly less than 1. It is suggested that the slope terms should be included in the estimation of propulsive performance for fish swimming with variable amplitude.

Human papillomavirus 16 DNA in NIH3T3 cells transformed by colonic cancer cellular DNA

Human papillomavirus (HPV) 16 DNA is closely associated with human cancers. It has been identified as an aetiological agent in cervical cancers and, recently, in colonic neoplasms. To further understand the role of HPV 16 DNA in colorectal carcinogenesis, NIH3T3 cells were transformed with high molecular weight DNA from colonic cancer cells and the expression of HPV 16 DNA detected. Both human Alu and HPV 16 DNA sequences were found in the type II foci of CC-M2T cells by Southern blot hybridisation. Additionally, 100% tumorigenicity in nude mice was seen. This study shows the transfection of HPV DNA from colonic cancers into NIH3T3 mouse cells and suggests that HPV type 16 might be associated with the malignant transformation of colonic cells.

Autumn southward 'return' migration of the mosquito Culex tritaeniorhynchus in China

Direct evidence for a southward 'return' migration in autumn of the mosquito Culex tritaeniorhynchus in China was obtained by aerial sampling with a net suspended from a balloon. In a preliminary study between 2 and 20 September 1990 at Jiangpu, near Nanjing, in Jiangsu Province, 11 females and 4 males of this species were taken at heights of 150-250 m. During 17-26 October 1991 at Dongxiang in northern Jiangxi Province, 44 mosquitoes (8 males, 36 females) were caught in the aerial net at heights of 80-380 m in northeasterly winds (E-NNW). Most of the specimens were flying within the subsiding air-mass behind a cold front. Cx tritaeniorhynchus was the only species identified (31 females) among the mosquitoes from Dongxiang. Of 24 females dissected, 17 had N stage ovaries--interpreted as diapause, five had stage I ovaries, one had stage II ovaries, and one was gravid (stage V), but none was freshly blood-fed. Cx tritaeniorhynchus is the main vector of Japanese viral encephalitis in China, and it is possible that the virus is reintroduced to northern temperate areas in spring by northward migration of infected Cx tritaeniorhynchus females.

[An animal model for colon cancer metastases to the lung and establishment of metastatic cancer cell line]

Death, in most colon cancer patients, is not caused by their primary tumors. Instead, metastasis is the major cause of morbidity and death. There are few appropriate animal models to investigate the complexity of the metastatic process. Therefore, the pathogenesis of the metastasis process is not clearly understood. We injected SW480 cells into the cecal wall of athymic nude mice to develop an animal model for colon cancer metastasis and to produce a metastasizing tumor. After metastatic foci formed in the murine lung, we established a metastatic cancer cell line, named CC-ML1, by in vitro primary culture. The characteristics of CC-ML1 were (1) a shorter doubling time; (2) a slightly higher metastatic rate and number of colonies; and (3) less morphological variation than those of SW480. Our research suggests that a higher metastatic potential may be found in CC-ML1 than in SW480 after the advanced cycles of the metastatic process. Thus, the primary animal model in this study may be useful in future studies of cells with a high metastatic potential in the pathogenesis of colon cancer metastases.

An animal model for colon cancer metastatic cell line with enhanced metastasizing ability. Establishment and characterization

We have developed an animal model for colon cancer metastasis and produced a metastasizing tumor after using a microinjection technique to inject SW480 cells into the cecal wall of athymic nude mice during "minilaparotomy." After the metastatic foci formed in murine lung, an in vitro primary culture was performed and a new metastatic cancer cell line, which was designated as CC-ML3, was established. The studies included: 1) the comparison between SW 480 and CC-ML3 in morphology, growth kinetics, seeding and plating efficiency, and karyotype; and 2) carcino-embryonic antigen determination, origination, and metastatic ability of CC-ML3. The results showed that CC-ML3 was significantly different from SW480 in vitro and possessed a high metastatic potential in vivo. This newly developed animal model may thus be useful for studying the biology and pathogenesis of metastasis of human colonic cancer.

Human papillomavirus type-related DNA and c-myc oncogene alterations in colon cancer cell lines

Although squamous-cell epithelium is the most frequent target site of human papillomavirus (HPV) infection, a similar infection is demonstrated in columnar epithelial cells in this paper. The papillomavirus expression in three cell lines was detected in colorectal adenocarcinoma of Chinese patients. The HPV-16 and HPV-18 DNA sequences were found in colorectal cancer cell lines, which might suggest the correlation of HPV to the etiology of colorectal cancers. In addition, c-myc oncogene was identified by amplification in all three colorectal cancer cell lines, but only normal germ-line fragments were found in control tissue. The correlation between HPV and c-myc, and the implications of these findings in colorectal cancers are also discussed.

[Production and characterization of monoclonal antibody against colon cancer associated antigen in Chinese]

Although many monoclonal antibodies have been made in human colon cancer, none of them are from the Chinese species. Recently, a colon cancer cell line CC-M2 established from a Chinese patient has been completely characterized and used as immunogen to produce monoclonal antibodies. Monoclonal antibodies were produced by standard hybridoma technique. The fusion rate was 95.8%. An isotype IgG1 of high proliferation named as Sam-2 was used in this study. The titers were measured around 10(4). Further studies on MoAb Sam-2 through indirect immunofluorescent and immunoperoxidase tests revealed its good specificity and sensitivity in colorectal cancer tissue. In CEA study, the result indicated that Sam-2 may react on a non-CEA related antigen. For further clinical application, the antigen was identified as a glycoprotein by chemical resistant test. In preliminary studies using sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunoblotting techniques, Sam-2 could recognize two closed antigens or a dimer antigen with molecular weight 25.2 and 27 Kd respectively.

Characterization of four newly established human colorectal adenocarcinoma cell lines from Chinese patients

Four colon adenocarcinoma cell lines, CC-M2, CC-M3, CC-M4, and CC-M2NM, have been established from surgical specimens of 18 unselected patients without the use of "feeder" cells and additional growth factors (e.g., insulin, hydrocortisone, etc.) in the culture medium. The methods of primary cultivation of tissue explants are described. Studies of determination of morphology, growth curve, plating efficiency, chromosomal analysis, CEA and beta-HCG synthesis, and tumorigenicity, were done to characterize the cell lines. Significant variations have been found in one of the four cell lines, both in vitro and in vivo studies. There are distinct phenotypes in the established cell lines which may be useful in studying the cell differentiation and progression of colorectal cancer.

Synthesis of a cyclic hexapeptide with sequence corresponding to murine tumor necrosis factor-(127-132) as a novel potential antitumor agent

A cyclic hexapeptide cyclo(Lys-Gly-Asp-Gln-Leu-Ser-) 10 was synthesized stepwise in solution by acylation of peptide ester trifluoroacetates directly with preactivated Boc-amino acids using the DCC/HOBt method; the final cyclization reaction was performed using the pentafluorophenyl ester method in solution (1-4). This peptide is a cyclic derivative of murine tumor necrosis factor-(127-132) and is designed as a potential antitumor agent. The cyclic peptide 10 displayed weak cytotoxic activity on three of the four human tumor cell lines tested.

Preoperative use of 5-fluorouracil to reduce operative bleeding in transurethral resection of prostate

We report results of a preliminary study on the preoperative use of 5-fluorouracil (5-FU) to reduce bleeding in transurethral resection of prostate. The average amount of blood lost for each case in the 5-FU group (30 cases) was calculated to be 10.16 mL/g, while the average for the control group was 15.12 mL/g. A blood loss of about 5 mL/g in the 5-FU group was less than in the control group. In addition, the reduction of bleeding was apparent in cases where the removed prostate weighed more than 10 g, and was especially marked in those cases where the removed prostate weighed 20-29 g. A pathologic examination of the 5-FU-treated prostate revealed atrophy of the glandular tissue, hyperplasia of the connective tissue, marked dilatation of the lumen of some of the acini which indicated exhaustion of glandular secretion, a decrease in the number of blood vessels, and formation of lymphoid follicles. All of the test group, with the exception of one whose white blood cell count once dropped to 2,700/mm3, did not show any side effects.