Investigation of laboratory methods for characterization of aquatic viruses in fish infected experimentally with infectious salmon anemia virus

Rapid growth in aquaculture has resulted in high-density production systems in ecologically and geographically novel conditions in which the emergence of diseases is inevitable. Well-characterized methods for detection and surveillance of infectious diseases are vital for rapid identification, response, and recovery to protect economic and food security. We implemented a proof-of-concept approach for virus detection using a known high-consequence fish pathogen, infectious salmon anemia virus (ISAV), as the archetypal pathogen. In fish infected with ISAV, we integrated histopathology, virus isolation, whole-genome sequencing (WGS), electron microscopy (EM), in situ hybridization (ISH), and reverse transcription real-time PCR (RT-rtPCR). Fresh-frozen and formalin-fixed tissues were collected from virus-infected, control, and sham-infected Atlantic salmon (Salmo salar). Microscopic differences were not evident between uninfected and infected fish. Viral cytopathic effect was observed in cell cultures inoculated with fresh-frozen tissue homogenates from 3 of 3 ISAV-infected and 0 of 4 uninfected or sham-infected fish. The ISAV genome was detected by shotgun metagenomics in RNA extracted from the medium from 3 of 3 inoculated cell cultures, 3 of 3 infected fish, and 0 of 4 uninfected or sham-infected fish, yielding sufficient coverage for de novo assembly. An ISH probe against ISAV revealed ISAV genome in multiple organs, with abundance in renal hematopoietic tissue. Virus was detected by RT-rtPCR in gill, heart, kidney, liver, and spleen. EM and metagenomic WGS from tissues were challenging and unsuccessful. Our proof-of-concept methodology has promise for detection and characterization of unknown aquatic pathogens and also highlights some associated methodology challenges that require additional investigation.

Specialist oncological surgery for removal of the ovaries and fallopian tubes in BRCA1 and BRCA2 pathogenic variant carriers may reduce primary peritoneal cancer risk to very low levels

Risk‐reducing bilateral salpingo‐oophorectomy (RRBSO) is highly effective for the prevention of high‐grade serous ovarian cancer (HGSOC) in BRCA1/2 pathogenic variant carriers (PVCs), but does not completely eliminate future risk of primary peritoneal cancer (PPC). The requirement to completely remove fallopian tubes at RRBSO and carefully exclude occult cancer/serous tubal intraepithelial carcinoma (STIC) lesions may not have been appreciated historically. We calculated rates of HGSOC and PPC in confirmed BRCA1/2 PVCs registered on the regional database in those who did (cases) and did not (controls) undergo RRBSO after genetic testing. Expected annual rates of ovarian/peritoneal cancer were 1% for BRCA1 ≥ 35 years and 0.5% for BRCA2 ≥ 45 years. Follow‐up before 35/45 years was “risk free” and lead time excluded RRBSO <35 years and <45 years for BRCA1 and BRCA2, respectively. Women were followed from personal mutation report (controls) or RRBSO (cases) to death, ovarian/peritoneal cancer or last follow‐up, whichever was sooner. In total, 891 cases (BRCA1 = 468, BRCA2 = 423) and 1302 controls had follow‐up ≥35 years (BRCA1 = 736) and ≥45 years (BRCA2 = 566), respectively, over a total of 7261.1 risk eligible years (mean = 8.15 years). Twenty‐one occult ovarian cancers were found at RRBSO (2.4%), 16 at stage 1. Post RRBSO, 56.97 ovarian/peritoneal cancers were expected but only 3 were observed (HR = 0.053; 95% CI = 0.013‐0.14), with combined Kaplan‐Meier analysis HR = 0.029 (95% CI = 0.009‐0.100, P < .001). Risk reduction was greater in specialist (HR = 0.03; 95% CI = 0.001‐0.13) compared to non‐specialist centres (HR = 0.11; 95% CI = 0.02‐0.37) (P = .07). In controls, 23.35 ovarian/peritoneal cancers were expected with 32 observed (HR = 1.37; 95% CI = 0.95‐1.91). RRBSO <35/<45 years reduces the risk of ovarian/peritoneal cancer by 95% in BRCA1/2 PVCs and may be greater in specialist centres.

What's new?

Women who carry genetic variants in BRCA1/2 that are linked to high‐grade serous ovarian cancer are advised to undergo risk‐reducing prophylactic bilateral salpingo‐oophorectomy (RRBSO). RRBSO, however, is associated with a significant residual risk of primary peritoneal cancer (PPC). Here, the rate of PPC following prophylactic surgery for high‐grade serous ovarian cancer was investigated among 2,193 BRCA1/2 mutation carriers who had undergone RRBSO. Estimates indicate that prophylactic surgery reduced the overall risk of PPC by 95 percent, a far greater reduction than previously described. Residual risk was lowest when RRBSO was carried out at specialist centers compared to non‐specialist centers.

BRCA1 and BRCA2 pathogenic variant carriers and endometrial cancer risk: A cohort study

Background

An association between BRCA pathogenic variants and an increased endometrial cancer risk, specifically serous-like endometrial cancer, has been postulated but remains unproven, particularly for BRCA2 carriers. Mechanistic evidence is lacking, and any link may be related to tamoxifen exposure or testing bias. Hysterectomy during risk-reducing bilateral salpingo-oophorectomy is, therefore, of uncertain benefit. Data from a large, prospective cohort will be informative.

Methods

Data on UK BRCA pathogenic variant carriers were interrogated for endometrial cancer diagnoses. Standardised incidence ratios (SIRs) were calculated in four distinct cohorts using national endometrial cancer rates; either from 1/1/1980 or age 20, prospectively from date of personal pathogenic variant report, date of family pathogenic variant report or date of risk-reducing salpingo-oophorectomy. Somatic BRCA sequencing of 15 serous endometrial cancers was performed to detect pathogenic variants.

Results

Fourteen cases of endometrial cancer were identified in 2609 women (1350 BRCA1 and 1259 BRCA2), of which two were prospectively diagnosed. No significant increase in either overall or serous-like endometrial cancer risk was identified in any of the cohorts examined (SIR = 1.70, 95% confidence interval = 0.74–3.33; no cases of serous endometrial cancer diagnosed). Results were unaffected by the BRCA gene affected, previous breast cancer or tamoxifen use. No BRCA pathogenic variants were detected in any of the serous endometrial cancers tested.

Conclusions

Women with a BRCA pathogenic variant do not appear to have a significant increased risk of all-type or serous-like endometrial cancer compared with the general population. These data provide some reassurance that hysterectomy is unlikely to be of significant benefit if performed solely as a preventive measure.

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Endometrial cancer risk was not increased in BRCA1/2 pathogenic variant carriers.

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Results were unaffected by BRCA gene, previous breast cancer or tamoxifen use.

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No specific increase in serous-like endometrial cancer risk was identified.

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Sequencing of 15 serous endometrial tumours revealed no pathogenic BRCA1/2 variants.

Hysterectomy

Hysterectomy is one of the most commonly performed major surgical procedures; approximately 100,000 are performed in the UK each year. Hysterectomy can be total or subtotal. The postulated benefits of subtotal hysterectomy--better pelvic floor and sexual function--have not been confirmed in randomised trials. Traditionally, hysterectomy was performed using either an abdominal or vaginal approach. More recently, laparoscopic techniques have been used. The decision about the technique used is often related to the surgeon's training and expertise, as the indications for each technique overlap. Vaginal hysterectomy is probably the preferred route because it is quicker and cheaper than laparoscopic hysterectomy, with no other clear differences in outcome measures. Laparoscopic hysterectomy has a number of advantages over abdominal hysterectomy: specifically, shorter hospital stay and quicker return to normal activities; complication rates, however, appear to be greater. This also seems to be the case with radical hysterectomy performed for cervical cancer.

Increase in peripheral blood mononuclear cell (PBMC)- and CD56+ cell-mediated killing of endometrial stromal cells by mycobacteria; a possible role in endometriosis immunotherapy?

BACKGROUND

Immunological therapies have shown promising results in the treatment of endometriosis. Mycobacteria are one of the most common immune therapies used in other diseases. We have assessed the effects of mycobacteria in altering the ability of peripheral blood mononuclear cells (PBMCs) and natural killer (NK) cells to kill endometrial stromal cells using an in vitro model. This may have implications in the immunotherapy of endometriosis.

METHODS

Primary cultures of endometrial stromal cells were grown from female patients and PBMCs were extracted from healthy female volunteers. Effector cells (PBMCs or NK cells) were exposed to varying concentrations of mycobacteria before their ability to kill cultured endometrial cells was tested using a 51Cr-release assay.

RESULTS

Treatment of effector cells with the Connaught Substrain Bacillus of Calmette and Guérin (BCG) led to increased killing of target cells by PBMCs and NK cells. The optimal concentration for treatment of effector cells with Connaught BCG was approximately 0.1 multiplicities of infection (m.o.i.). There was a trend towards increased killing after treatment with Pasteur BCG. CD56+ (NK) cells treated with BCG at 0.1 m.o.i. showed increased killing of target cells compared with untreated effector cells.

CONCLUSIONS

Endometrial stromal cells are susceptible to killer cells activated by mycobacteria. This in vitro work suggests a possible role for mycobacteria in the immunotherapy of endometriosis.

Anti-Proliferative Effect of Mycobacteria, IFN-γ and TNF-α on Primary Cultures Derived from Endometrial Stroma: Possible Relevance to Endometriosis?

PROBLEM

To assess the effects of mycobacteria and inflammatory cytokines on proliferation of endometrial stromal cells. An effect on endometrial stromal cell proliferation in vitro may suggest a similar effect on endometriotic cells in vivo.

METHOD OF STUDY

Primary cultures of endometrial stromal cells were grown from female volunteers. Proliferation of cells was assessed by cell counting and incorporation of tritiated thymidine after exposure to mycobacteria or inflammatory cytokines.

RESULTS

When assessed by cell counting, stromal cell growth was reduced following treatment with Connaught Bacillus of Calmette and Guérin (BCG) and Pasteur BCG: Mycobacterium smegmatis demonstrated a cytotoxic effect. Addition of the cytokines interferon (IFN)-gamma or tumour necrosis factor (TNF)-alpha at high concentrations led to a reduction in cell growth by 24 hr in two of three cell lines. A reduction in proliferation was also found when assessed by tritiated thymidine incorporation, which was statistically significant for Connaught BCG and M. smegmatis.

CONCLUSIONS

Endometrial stromal cells are susceptible to the anti-proliferative effects of mycobacteria. The BCG and other mycobacteria are known immunomodulators in other disease conditions. Further work is required to assess whether these in vitro effects might translate into a useful therapy for endometriosis.

The effects and effectiveness of laparoscopic excision of endometriosis: a prospective study with 2-5 year follow-up

BACKGROUND

This study investigates the outcomes for women up to 5 years after laparoscopic excision of endometriosis.

METHODS

In this prospective observational cohort study, 254 women with chronic pelvic pain were referred to two units specializing in minimal access surgical management of endometriosis. Of these, 216 women underwent surgical assessment and 176 were confirmed to have endometriosis. Questionnaires and visual analogue scale (VAS) scores for dysmenorrhoea, non-menstrual pelvic pain, dyspareunia and dyschesia as well as quality of life instruments; the EQ-5Dindex and EQ-5Dvas, Short-Form 12 (SF-12) and sexual activity questionnaires were completed pre-operatively. Intra-operative details of revised American Fertility Society (rAFS) stage, site of disease, associated tests, duration of surgery and complications were noted. Follow-up was performed by postal questionnaire and chart review. For women who had further surgery, rAFS stage, site of disease, other procedures and histology were all recorded.

RESULTS

Pain scores were all significantly reduced at 2-5 years for dysmenorrhoea (median VAS baseline versus follow-up 2-5 years); 9 versus 3.3 (P < 0.0001), non-menstrual pelvic pain 8 versus 3 (P < 0.0001), dyspareunia 7 versus 0 (P < 0.0001) and dyschesia 7 versus 2 (P < 0.0001). Quality of life was improved for the EQ-5Dindex (P = 0.008 and the EQ-5Qvas (P = 0.03) and for sexual function with pleasure (P = 0.001) and habit (P = 0.012) being improved and discomfort being decreased (P = 0.001). The chance of requiring further surgery as determined by the Kaplan-Meier survival curve was 36%. A rAFS score of >70 was predictive of requiring further surgery (P = 0.03). Of women who had further surgery, endometriosis was found histologically in 68%.

CONCLUSIONS

Laparoscopic excision of endometriosis significantly reduces pain and improves quality of life for up to 5 years. The probability of requiring further surgery is 36%. Return of pain following laparoscopic excision is not always associated with clinical evidence of recurrence.

The Western Australian experience of the use of en bloc resection of ovarian cancer with concomitant rectosigmoid colectomy

OBJECTIVES

The aim of this study was to assess the technique of en bloc resection of ovarian cancer with concomitant rectosigmoid colectomy, in relation to perioperative complication rates, and its impact on survival following the procedure.

METHODS

A retrospective review was performed of the case notes of 129 consecutive procedures performed between 1989 and 2000 in a regional cancer center. RESULTS. Overall, 48.8% of patients suffered a major or minor complication. Complications relating to bowel anastomosis occurred in 2.4%. Perioperative mortality was 3.1%. Median survival for the group as a whole was 30.6 months. Patients who were optimally debulked had a significantly longer median survival time.

CONCLUSION

En bloc resection of ovarian cancer with concomitant rectosigmoid colectomy allows a high rate of optimal debulking with acceptable morbidity, mortality, and survival.

Safety and efficacy of low anterior en bloc resection as part of cytoreductive surgery for patients with ovarian cancer

OBJECTIVE

To examine the feasibility and safety of a low anterior resection of the rectosigmoid plus adjacent pelvic tumour as part of primary cytoreduction for ovarian cancer.

METHODS

This study included 65 consecutive patients with primary ovarian cancer who had debulking surgery from 1996 through 2000. All patients underwent an en bloc resection of ovarian cancer and a rectosigmoid resection followed by an end-to-end anastomosis. Parameters for safety and efficacy were considered as primary statistical endpoints for the aim of this analysis.

RESULTS

Postoperative residual tumour was nil, <1 cm, and >1 cm in 14, 34, and 14 patients, respectively. The median postoperative hospital stay was 11 days (range, 6 to 50 days). Intraoperative complications included an injury to the urinary bladder in one patient. Postoperative complications included wound complications (n = 14, 21.5%), septicemia (n = 9, 13.8%), cardiac complications (n = 7, 10.8%), thromboembolic complications (n = 5, 7.7%), ileus (n = 2, 3.1%), anastomotic leak (n = 2, 3.1%), and fistula (n = 1, 1.5%). Reasons for a reoperation during the same admission included repair of an anastomotic leak (n = 1), postoperative hemorrhage (n = 1), and wound debridement (n = 1). Wound complications, septicemia, and anastomotic leak formation were more frequent in patients who had a serum albumin level of < or =30 g/L preoperatively. There was one surgically related mortality in a patient who died from a cerebral vascular accident 2 days postoperatively.

CONCLUSIONS

An en bloc resection as part of primary cytoreductive surgery for ovarian cancer is effective and its morbidity is acceptably low.

Neural networks in the diagnosis of malignant ovarian tumours

OBJECTIVE

To assess the role of neural networks in predicting the likelihood of malignancy in women presenting with ovarian tumours.

DESIGN

Retrospective case study.

SETTING

University Department of Obstetrics and Gynaecology, St James's Hospital, Leeds.

METHODS

Information from 217 cases with histologically proven benign, borderline or malignant tumours was extracted for study. Four variables (age, ultrasound findings with and without colour Doppler imaging and CA125) were entered in the neural network classifier. The neural network results were compared with logistic regression analysis.

RESULTS

When used in the neural network the variables of age, CA125 and ultrasound score produced the best result with a sensitivity of 95% and a corresponding specificity of 78% in predicting malignancy. Logistic regression gave a sensitivity or 82% for a specificity of 51%.

CONCLUSION

The neural network is a good method of combining diagnostic variables and may be a useful predictor of malignancy in women presenting with ovarian tumours. A comparison of the performance of the neural network with conventional diagnostic methods would be warranted prior to use in clinical practice.

Recurrent pain after hysterectomy and bilateral salpingo-oophorectomy for endometriosis: evaluation of laparoscopic excision of residual endometriosis

Endometriosis can represent with a variety of symptoms including pelvic pain, dyspareunia and pain with defaecation, up to several years after hysterectomy and bilateral salpingo-oophorectomy. This may occur when all endometriotic tissue is not excised at the time of the initial procedure. Although excision of endometriosis at this time would be preferable, we have found laparoscopic excision of residual endometriosis to be effective in relieving endometriosis associated pain.

Phosphorylation of rat muscle acetyl-CoA carboxylase by AMP-activated protein kinase and protein kinase A

This study was designed to compare functional effects of phosphorylation of muscle acetyl-CoA carboxylase (ACC) by adenosine 3',5'-cyclic monophosphate-dependent protein kinase (PKA) and by AMP-activated protein kinase (AMPK). Muscle ACC (272 kDa) was phosphorylated and then subjected to sodium dodecyl sulfate-polyacrylamide gel electrophoresis followed by autoradiography. Functional effects of phosphorylation were determined by measuring ACC activity at different concentrations of each of the substrates and of citrate, an activator of the enzyme. The maximal velocity (Vmax) and the Michaelis constants (Km) for ATP, acetyl-CoA, and bicarbonate were unaffected by phosphorylation by PKA. Phosphorylation by AMPK increased the Km for ATP and acetyl-CoA. Sequential phosphorylation by PKA and AMPK, first without label and second with label, appeared to reduce the extent of label incorporation, regardless of the order. The activation constant (Ka) for citrate activation was increased to the same extent by AMPK phosphorylation, regardless of previous or subsequent phosphorylation by PKA. Thus muscle ACC can be phosphorylated by PKA but with no apparent functional effects on the enzyme. AMPK appears to be the more important regulator of muscle ACC.