Optogenetic approaches to vision restoration.

Inherited retinal disease (IRD) affects about 1 in 3000 to 1 in 5000 individuals and is now believed to be the most common cause of blindness registration in developed countries. Until recently, the management of such conditions had been exclusively supportive. However, advances in molecular biology and medical engineering have now seen the rise of a variety of approaches to restore vision in patients with IRDs. Optogenetic approaches are primarily aimed at rendering secondary and tertiary neurons of the retina light-sensitive in order to replace degenerate or dysfunctional photoreceptors. Such approaches are attractive because they provide a "causative gene-independent" strategy, which may prove suitable for a variety of patients with IRD. We discuss theoretical and practical considerations in the selection of optogenetic molecules, vectors, surgical approaches and review previous trials of optogenetics for vision restoration. Optogenetic approaches to vision restoration have yielded promising results in pre-clinical trials and a phase I/II clinical trial is currently underway (ClinicalTrials.gov NCT02556736). Despite the significant inroads made in recent years, the ideal optogenetic molecule, vector and surgical approach have yet to be established.

First-in-human study of the safety and viability of intraocular robotic surgery.

Microsurgery of the retina would be dramatically improved by instruments that offer supra-human precision. Here, we report the results of a first-in-human study of remotely controlled robot-assisted retinal surgery performed through a telemanipulation device. Specifically, 12 patients requiring dissection of the epiretinal or inner limiting membrane over the macula were randomly assigned to either undergo robot-assisted-surgery or manual surgery, under general anaesthesia. We evaluated surgical success, duration of surgery and amount of retinal microtrauma as a proxy for safety. Surgical outcomes were equally successful in the robotic-surgery and manual-surgery groups. Differences in the amount of retinal microtrauma between the two groups were statistically insignificant, yet dissection took longer with robotic surgery (median time, 4 min 5 s) than with manual surgery (1 min 20 s). We also show the feasibility of using the robot to inject recombinant tissue plasminogen activator under the retina to displace sight-threatening haemorrhage in three patients under local anaesthesia. A safe and viable robotic system for intraocular surgery would enable precise and minimally traumatic delivery of gene therapy or cell therapy to the retina.

Novel non-contiguous exon duplication in choroideremia.

The importance of establishing a genetic diagnosis in patients with a choroideremia phenotype has been underscored by the advent of gene replacement therapy for this condition. Here, we describe a complex imbalance at the CHM locus in a male patient with classical disease. At the DNA level, this imbalance consists of 2 non-contiguous duplications (exons 1-2 and 9-12). Further characterization suggests the generation of 2 independent CHM transcriptional units, one of which may produce a deleted form of the Rab escort protein 1 protein. Expression of such a type of aberrant protein in photoreceptors may have important implications when considering gene therapy for this disorder.

Collaborative case conferences in rectal cancer: case series in a tertiary care centre.

BACKGROUND: In many hospitals, resource barriers preclude the use of preoperative multidisciplinary cancer conferences (mccs) for consecutive patients with cancer. Collaborative cancer conferences (cccs) are modified mccs that might overcome such barriers. METHODS: We established a ccc at an academic tertiary care centre to review preoperative plans for patients with rectal cancer. Attendees included only surgeons who perform colorectal cancer procedures and a radiologist with expertise in cross-sectional imaging. Individual reviews began with the primary surgeon presenting the case information and initial treatment recommendations. Cross-sectional images were then reviewed, the case was discussed, and consensus on ccc-treatment recommendations was achieved. Outcomes for the present study were changes in treatment recommendations defined as "major" (that is, redirection of patient to preoperative radiation from straight-to-surgery or uncertain plan, or redirection of the patient to straight-to-surgery from preoperative radiation or plan uncertain) or as "minor" (that is, referral to a multidisciplinary cancer clinic, request additional tests, change type of neoadjuvant therapy, change type of surgery). Chart reviews provided relevant patient, tumour, and treatment information. RESULTS: Between September 2011 and September 2012, 101 rectal cancer patients were discussed at a ccc. Of the 35 management plans (34.7%) that were changed as a result, 8 had major changes, and 27 had minor changes. Available patient and tumour factors did not predict for a change in treatment recommendation. CONCLUSIONS: Preoperative cccs at a tertiary-care centre changed treatment recommendations for one third of patients with rectal cancer. Given that no specific factor predicted for a treatment plan change, it is likely prudent that all rectal cancer patients undergo some form of collaborative review.

Eastern Canadian Colorectal Cancer Consensus Conference 2013: emerging therapies in the treatment of pancreatic, rectal, and colorectal cancers.

The annual Eastern Canadian Colorectal Cancer Consensus Conference held in Montreal, Quebec, 17-19 October 2013, marked the 10-year anniversary of this meeting that is attended by leaders in medical, radiation, and surgical oncology. The goal of the attendees is to improve the care of patients affected by gastrointestinal malignancies. Topics discussed during the conference included pancreatic cancer, rectal cancer, and metastatic colorectal cancer.

Clustering and stability of functional lower gastrointestinal symptom after enteric infection.

BACKGROUND: Current diagnostic criteria for functional gut disorder are based on symptom clusters observed after sporadic onset. It remains unclear whether symptoms group similarly in functional disorders of postinfectious etiology. We utilized observational data from the Walkerton Health Study (WHS) to: (i) determine groupings of functional gastrointestinal symptoms among patients exposed to acute gastroenteritis (GE), and (ii) assess the stability of these symptoms grouping over time. METHODS: WHS participants 16 years of age and older at the time of the outbreak were included, if they had completed a modified Talley's Bowel Disease Questionnaire (BDQ) and responded 'yes' to a screening question as to whether they had experienced abdominal pain in the last 2 weeks. Exploratory factor analysis (EFA) using tetrachoric correlations was undertaken to identify symptom constructs. Hierarchical cluster analysis using the k-means method was used to create cluster groupings of patients based on these factors. Confirmatory factors analysis using responses to BDQ questionnaire administered at 4, 6, and 8 years after the outbreak was performed to assess stability of symptom domains over time. KEY RESULTS: A total of 773 participants were eligible for inclusion [62.2% female, mean age 43.1 years (SD = 16.9)]. Eighty-four percent were exposed to acute GE during the outbreak. Two symptom groupings of abdominal pain with either diarrhea or constipation together explained 85.7% of the total variance. Cluster analysis identified four patients groupings based on these factors. These clusters could be qualitatively described as diarrhea- and constipation-predominant, mixed bowel pattern, and no predominance of bowel movements abnormalities. Results of the confirmatory factor analysis validating symptom domains identified in Year 1 showed that the baseline model was acceptable at 4 and 6 years after the outbreak and approached acceptability at 8 years. Values of root mean square error of approximation were 0.071 (90% CI: 0.053, 0.089) at 4 and 0.071 (90% CI: 0.049, 0.092) at 6 years and 0.089 (90% CI: 0.065, 0.114) at 8 years. CONCLUSIONS & INFERENCES: The majority of subjects with postinfectious functional bowel disorders belong to groups with symptoms of abdominal pain and either diarrhea or constipation. These symptom groupings were stable across time.

Outcomes following a limited approach to radiotherapy in rectal cancer.

BACKGROUND: Variation in the use of neoadjuvant and adjuvant radiotherapy for rectal cancer suggests an opportunity to avoid it in all but patients at highest risk of local recurrence. METHODS: Between 1 July 1999 and 1 February 2006, patients with primary rectal cancer were treated by a single surgeon operating at McMaster University, Hamilton, Ontario, Canada. Digital rectal examination and pelvic computed tomography were used to determine whether the mesorectal margin was threatened by tumour and thus whether preoperative radiotherapy would be needed. The study outcome was local tumour recurrence. RESULTS: Forty-six (48 per cent) of 96 patients received preoperative radiation therapy. The median follow-up was 4·2 years. Tumours were fixed or tethered in 31 (67 per cent) of the 46 irradiated patients. In contrast, no tumour was fixed in unirradiated patients and only ten (20 per cent) of the 50 tumours were tethered. The proportion of patients with stage I or II tumours based on final pathology was similar: 61 per cent (28 of 46) and 56 per cent (28 of 50) in irradiated and unirradiated groups respectively (P = 0·287). There were four (9 per cent) and two (4 per cent) local recurrences among irradiated and unirradiated patients respectively (P = 0·422). CONCLUSION: Limiting preoperative radiotherapy in rectal cancer to patients with a threatened circumferential margin does not compromise patient outcome.

Preoperative or postoperative therapy for stage II or III rectal cancer: an updated practice guideline.

AIMS: Uncertainty remains regarding the optimal therapy for patients with stage II or III rectal cancer. Systematic reviews and practice guidelines on preoperative and postoperative therapy for rectal cancer were published by the Gastrointestinal Cancer Disease Site Group in 2003 and 2000, respectively. The systematic reviews were updated and revised and new recommendations for preoperative and postoperative therapy were developed based on the updated body of evidence. The following research questions were addressed: After appropriate preoperative staging tests, should patients with resectable clinical stage II or III rectal cancer be offered preoperative radiotherapy (with or without chemotherapy)? What is the role of postoperative radiotherapy and/or chemotherapy for patients with resected stage II or III rectal cancer who have not received preoperative radiotherapy, in terms of improving survival and delaying local recurrence? MATERIALS AND METHODS: The MEDLINE, EMBASE and Cochrane Library databases, as well as meeting proceedings from the American Society of Clinical Oncology, were searched for reports of randomised controlled trials and meta-analyses comparing preoperative or postoperative therapy with surgery alone or other preoperative or postoperative therapy for stage II or III rectal cancer. The draft practice guideline and systematic reviews were distributed through a mailed survey to 129 health care providers in Ontario for review. RESULTS: Systematic reviews on preoperative and postoperative therapy for rectal cancer were developed. On the basis of the evidence contained in these reviews, the Gastrointestinal Cancer Disease Site Group drafted recommendations. Of the 33 practitioners who responded to the mailed survey, 97% agreed with the draft recommendations as stated, 88% agreed that the report should be approved as a practice guideline and 94% indicated that they were likely to use the guideline in their own practice. CONCLUSIONS: Preoperative chemoradiotherapy is preferred, compared with standard fractionation preoperative radiotherapy alone, to decrease local recurrence. Preoperative chemoradiotherapy is also preferred, compared with a postoperative approach, to decrease local recurrence and adverse effects. For patients with relative contraindications to chemotherapy in the preoperative period, an acceptable alternative is preoperative radiotherapy alone followed by surgery. Patients with resected stage II or III rectal cancer who have not received preoperative radiotherapy should be offered postoperative therapy with concurrent chemoradiotherapy plus fluoropyrimidine-based chemotherapy.

Colour vision deficiency.

Colour vision deficiency is one of the commonest disorders of vision and can be divided into congenital and acquired forms. Congenital colour vision deficiency affects as many as 8% of males and 0.5% of females--the difference in prevalence reflects the fact that the commonest forms of congenital colour vision deficiency are inherited in an X-linked recessive manner. Until relatively recently, our understanding of the pathophysiological basis of colour vision deficiency largely rested on behavioural data; however, modern molecular genetic techniques have helped to elucidate its mechanisms. The current management of congenital colour vision deficiency lies chiefly in appropriate counselling (including career counselling). Although visual aids may be of benefit to those with colour vision deficiency when performing certain tasks, the evidence suggests that they do not enable wearers to obtain normal colour discrimination. In the future, gene therapy remains a possibility, with animal models demonstrating amelioration following treatment.

Patterns of care for the initial management of cervical cancer in Ontario.

OBJECTIVE: To facilitate the planning of resources for cancer services in Ontario, Cancer Care Ontario commissioned an evaluation of operative services delivered for cervical cancer. METHODS: Women with an incident diagnosis of cervical cancer were identified from 1 April, 2003 to 31 March, 2004 using the Ontario Cancer Registry. Record linkages were created to other provincial health databases such as the Ontario Health Insurance Plan. RESULTS: There were 513 incident cases. Disease-specific rates of cancer were higher in rural areas and those from lower income quintiles. Forty-three percent of women had no surgery. Use of surgery did not appear to vary by SEC, urban/rural residence or LHIN. Women of younger age were more like to receive surgery for cervical cancer. Gynecologists conducted 63% of the operations. Gynecologics were most likely to complete a lymphadenectomy (70.3%). All women were assessed by CXR. Only 22% of women had a CT scan of the abdomen and pelvis. Radiation consults were performed in half of the women with cervix cancer but treatment was only delivered to half of those seen. Medical oncologists saw about 10% of women with cervical cancers. CONCLUSIONS: There appear to be variations in incidence rates of cervical cancer, with cancers being more frequent in rural areas. In two-thirds of the population, surgery is performed in the region where the patient lives. Subspecialty care from gynecologic oncologists was provided to one-third of women. These preliminary data would be enhanced with further information such as comorbidity, treatment intent (palliative/curative), histology, grade and stage.

Patterns of care in the initial management of women with vulvar cancers in Ontario.

BACKGROUND: To facilitate the planning of future resources for cancer services in Ontario, Cancer Care Ontario commissioned an evaluation of operative services delivered for vulvar cancer. METHODS: Women with an incident diagnosis of vulvar malignancy were identified from 1, April 2003 to 31 March, 2004 using the Ontario Cancer Registry. Record linkages were created to other provincial health databases such as the Ontario Health Insurance Plan. RESULTS: Vulvar cancers affected 148 women. Disease specific rates of cancer were higher in rural areas and in women in the lower income quintiles. No surgery occurred in 17.6% of women. Use of surgery did not appear to vary by urban/rural residence or LHIN. Ontario's 17 gynecologic oncologists performed 75% of the surgeries. Groin lymphadenectomy rate was 52.8%. Surgery was performed in the LHIN of residence for 41% of women. All women were assessed by CXR. CT scan of the abdomen and pelvis occurred in 77%. MRIs were done infrequently. Radiation consults were preformed in half of the women with vulvar cancer but treatment was only delivered in half of those seen. Medical oncologists saw about 10% of women with gynecologic cancers. CONCLUSIONS: There appear to be variations in incidence rates of vulvar cancer with disease being more frequent in rural areas. Subspecialty care from gynecologic oncologists was provided to 75% of women. Rates of lymphadenectomy as part of a surgical attempt occurred in 52.8% of women. These data would be enhanced with further information such as comorbidity, treatment intent (palliative/curative), histology, grade and stage.

Patterns of care in the initial management of women with ovarian cancer in Ontario.

BACKGROUND: To facilitate the planning of future resources for cancer services in Ontario, Cancer Care Ontario commissioned an evaluation of operative services delivered for ovarian cancers. The affected population was characterized in terms of age, location of residence, and SES. Operative care delivery was described in terms of inpatient verses outpatient access, LHIN of treatment, surgical specialist providing treatment, and specific operative procedures. The investigations and consults around the time of diagnosis are described. METHODS: Women with an incident diagnosis of an ovarian malignancy were identified from 1 April 2003 to 31 March 2004 using the Ontario Cancer Registry. Record linkages were created to other provincial health databases such as the Ontario Health Insurance Plan. RESULTS: We report on 963 women with ovarian cancer. The incidence of disease was related to increasing age. Access to surgery correlated with the highest income quintile, urban residence and LHIN. Twenty-seven percent of women did not have surgery for their ovarian cancer. Women of younger age were more like to receive surgery for ovarian cancer. Use of a laparotomy for biopsy was most common in community hospital (40%). Lymphadenectomy rates were low overall; rates for gynecologic oncologists were 13.2%. All women were assessed by CXR. CT scan of abdomen and pelvis occurred in 77% of women. MRIs were done infrequently. Medical oncology were involved in 26.6% of the patients. CONCLUSIONS: These pilot data would be enhanced with further information such as comorbidity, treatment intent (palliative/curative), histology, grade and stage. However, there are clear referral patterns to academic centres which means a need for manpower and hospital resources to deal with this population.

Patterns of surgical care for uterine cancers in Ontario.

OBJECTIVES: To facilitate the planning of future resources for cancer services in Ontario, Cancer Care Ontario commissioned an evaluation of operative services delivered for uterine cancer. METHODS: Women with an incident diagnosis of a uterine malignancy were identified from 1 April 2003 to 31 March 2004 using the Ontario Cancer Registry. Record linkages were created to other provincial health databases such as the Ontario Health Insurance Plan. RESULTS: Uterine cancer affected 1,436 women. Disease specific rates of cancer were higher in rural areas and those from the highest income quintiles. Surgery occurred in 94.7% of women. Use of surgery did not appear to vary by SEC, urban/rural residence or LHIN. Gynecologists conducted 76.1% of the operations. Lymphadenectomy took place in 18.7% of women. Lymphadenectomy rates were highest in gynecologic oncologists (43.3%). All women were assessed by CXR. Radiation therapy consults were preformed in half of the women with uterine cancer but treatment was only delivered in half of those seen. Medical oncologists saw about 6.3% of women with uterine cancers. CONCLUSIONS: There appear to be variations in incidence rates of uterine cancer with disease being more frequent in those of the highest SES. In two-thirds of the population, surgery is delivered in the region where the patient lives. Subspecialty care from gynecologic oncologists was provided to one-third of women. Rates of lymphadenectomy as part of a surgical attempt to assess disease spread appear low. These pilot data would be enhanced with further information such as comorbidity, treatment intent (palliative/curative), histology, grade and stage.

Urea and carbamate derivatives of primaquine: synthesis, cytostatic and antioxidant activities.

The novel urea primaquine derivatives 3 were prepared by aminolysis of primaquine benzotriazolide 2 with several hydroxyamines and ethylendiamine, while carbamates 4 were synthesized from the same precursor 2 and alcohols. All compounds are fully chemically characterized and evaluated for their cytostatic and antioxidant activities. The most prominent antiproliferative activity was obtained by compounds 3c, 3d, 3g, and 5b (IC(50)=9-40 microM). 1-(5-Hydroxypentyl)-3-[4-(6-methoxy-quinolin-8-ylamino)-pentyl]urea (3c) showed extreme selectivity toward SW 620 colon cancer cells (IC(50)=0.2 microM) and a bit less toward lung cancer cells H 460. Hydroxyurea 3h showed the highest interaction with DPPH. Primaquine twin drug 3g showed very significant inhibition on LOX soybean (IC(50)=62 microM). Almost all the tested derivatives highly inhibited lipid peroxidation, significantly stronger than primaquine phosphate.

Rectal cancer surgery and regional lymph nodes.

In patients with rectal cancer, the status of regional or mesorectal lymph nodes is central to both tumor staging and predicting local and distant recurrence. The importance of mesorectal lymph nodes in rectal cancer should inform treatment decisions around pre-operative diagnostic imaging, surgical techniques, pathologic assessment, and the use of radiation therapy.

Invasive vulvar cancer in a woman with human immunodeficiency virus: case report and review of the literature.

BACKGROUND: : HIV is associated with a decrease in cellular immunity which allows for persistence of high-risk HPV types and this can predispose the woman to dysplasia or cancer of the gynecologic tract. CASE: : We present a case of Stage 3 vulvar cancer in a 33-year-old HIV positive woman. The patient was treated with primary radiation; unfortunately there was persistent disease. Exenterative surgery was planned but abandoned due to a positive presacral node. CONCLUSION: : The optimal treatment of advanced vulvar cancer in HIV positive patients remains unclear given the small number of cases reported in the literature. Lessons from the anal cancer literature may help inform the care of vulvar cancer patients given the comparable high prevalence of this disease in the patients infected with HIV.

Blue cone monochromatism: a phenotype and genotype assessment with evidence of progressive loss of cone function in older individuals.

AIM: To perform a detailed clinical and psychophysical assessment of the members of three British families affected with blue cone monochromatism (BCM), and to determine the molecular basis of disease in these families. METHODS: Affected and unaffected members of three families with BCM were examined clinically and underwent electrophysiological and detailed psychophysical testing. Blood samples were taken for DNA extraction. The strategy for molecular analysis was to amplify the coding regions of the long wavelength-sensitive (L) and middle wavelength-sensitive (M) cone opsin genes and the upstream locus control region by polymerase chain reaction, and to examine these fragments for mutations by direct sequencing. RESULTS: We have confirmed the reported finding of protan-like D-15 arrangements of patients with BCM. In addition, we have demonstrated that the Mollon-Reffin (MR) Minimal test is a useful colour-discrimination test to aid in the diagnosis of BCM. Affected males were shown to fail the protan and deutan axes, but retained good discrimination on the tritan axis of the MR test, a compelling evidence for residual colour vision in BCM. This residual tritan discrimination was also readily detected with HRR plates. In two families, psychophysical testing demonstrated evidence for progression of disease. In two pedigrees, BCM could be linked to unequal crossovers within the opsin gene array that resulted in a single 5'-L/M-3' hybrid gene, with an inactivating Cys203Arg mutation. The causative mutations were not identified in the third family. CONCLUSIONS: The MR test is a useful method of detecting BCM across a wide range of age groups; residual tritan colour discrimination is clearly demonstrated and allows BCM to be distinguished from rod monochromatism. BCM is usually classified as a stationary cone dysfunction syndrome; however, two of our families show evidence of progression. This is the first report of progression associated with a genotype consisting of a single 5'-L/M-3' hybrid gene carrying an inactivating mutation. We have confirmed that the Cys203Arg inactivating mutation is a common sequence change in blue cone monochromats.

Cone dystrophy phenotype associated with a frameshift mutation (M280fsX291) in the alpha-subunit of cone specific transducin (GNAT2).

AIM: To describe the phenotype of a three generation consanguineous Pakistani family containing six individuals with autosomal recessive cone dystrophy caused by mutation in GNAT2. METHODS: Five of the six affected individuals underwent an ophthalmological examination, electrodiagnostic testing, fundus photography, autofluorescence imaging, and detailed psychophysical testing. RESULTS: All five examined patients had a history of nystagmus from infancy, photophobia, defective colour vision, and poor visual acuity. The nystagmus in three of the individuals had lessened with time. Fundus examination revealed an abnormal foveal appearance, without frank atrophy or pigmentation. Electroretinography (ERG) revealed absent ISCEV cone flicker ERGs with some preservation of responses to short wavelength stimulation. Rod ERGs showed no definite abnormality, but maximal (mixed rod-cone) response a-wave amplitudes were mildly subnormal. Rudimentary residual colour vision was detected in three individuals. There is clinical evidence of progressive visual acuity reduction in two older individuals. CONCLUSION: Mutation in the alpha-subunit of cone specific transducin (GNAT2) is characterised by an infantile onset cone dystrophy. Some affected individuals may show deterioration of visual acuity with time.