Real-world hepatitis C prevalence and treatment uptake at opioid agonist therapy clinics in Ontario, Canada

Widespread screening for hepatitis C virus (HCV) is necessary for Canada to meet its HCV elimination goals by 2030. People who currently or previously injected drugs are at high risk for HCV. Opioid agonist therapy (OAT, such as methadone and buprenorphine) has been shown to help stabilize the lives of people who are opioid-dependent. The distribution of OAT in North America typically requires daily, weekly, or monthly clinic visits and presents an opportunity for engagement, screening and treatment for those at high-risk of HCV. In this study, HCV screening was conducted by staff at OAT clinics in Ontario from 2016 to 2020 and those with chronic infections were treated on-site with direct-acting antivirals. Point-of-care or dried blood spot (DBS) testing was used for antibodies, DBS or serum for HCV RNA and serum for HCV RNA at SVR12 (sustained virological response). Clinics screened 1954 people (mean age 40 years ±12, 63% male). Forty-five percent were antibody positive, of whom 64% were HCV RNA+. Eighty percent of those RNA+ set an appointment in which 99% attended. Ninety-six percent started treatment with 87% completing treatment. Sixty-eight percent of people who completed treatment submitted a sample for SVR12 testing of which 97% achieved a virological cure. Results suggest that HCV screening and treatment at OAT clinics is feasible, effective and warrants expansion. Data suggest strong treatment adherence due to high rates of SVR12 comparable with other OAT-based HCV treatment programs. The lack of SVR12 sampling could be addressed by either on-site phlebotomy or incentivizing SVR12 sampling.

Possible prognostic impact of PKCι genetic variants in prostate cancer

BACKGROUND

Single nucleotide polymorphisms (SNPs) have been linked with prostate cancer (PCa) and have shown potential as prognostic markers for advanced stages. Loss of function mutations in PKCι have been linked with increased risk of malignancy by enhancing tumor cell motility and invasion. We have evaluated the impact of two coding region SNPs on the PKCι gene (PRKCI) and their prognostic potential.

METHODS

Genotypic association of non-synonymous PKCι SNPs rs1197750201 and rs1199520604 with PCa was determined through tetra-ARMS PCR. PKCι was docked with interacting partner Par-6 to determine the effect of these variants on PKCι binding capabilities. Molecular dynamic simulations of PKCι docked with Par-6 were performed to determine variant effects on PKCι protein interactions. The possible impact of changes in PKCι protein interactions on epithelial cell polarity was hypothesized.

RESULTS

PKCι rs1199520604 mutant genotype TT showed association with PCa (p = 0.0055), while rs1197750201 mutant genotype AA also showed significant association with PCa (P = 0.0006). The binding interaction of PKCι with Par-6 was altered for both variants, with changes in Van der Waals energy and electrostatic energy of docked structures.

CONCLUSION

Genotypic analysis of two non-synonymous PKCι variants in association with PCa prognosis was performed. Both variants in the PB1 domain showed potential as a prognostic marker for PCa. In silico analysis of the effect of the variants on PKCι protein interactions indicated they may be involved in PCa progression through aberration of epithelial cell polarity pathways.

Accuracy of portable ultrasound for obstetric biometry

OBJECTIVE

We assessed the accuracy of two portable ultrasound machines (PUM) in obtaining fetal biometry and estimating gestational age.

METHODS

We analyzed data from the Fetal Age Machine Learning Initiative, an observational study of pregnant women in the United States and Zambia. Each participant underwent assessment by an experienced sonographer using both a high-specification ultrasound machine (HSUM) and a PUM (either Butterfly iQ or Clarius C3) to measure fetal biometry and calculate estimated gestational age (EGA) at each visit. Through comparison of paired PUM-HSUM scans, we estimated agreement between individual biometry measurements and aggregate gestational age estimates by reporting mean difference, along with intraclass correlation coefficient (ICC) and Bland-Altman plots, adjusting for trend.

RESULTS

881 participants contributed 1386 paired PUM-HSUM ultrasound studies between April and December 2021. PUM studies included 991 Butterfly and 395 Clarius. Gestational age at scan ranged from 7 to 38 weeks. Compared to HSUM, the Butterfly PUM had a mean difference of -0.20 days (95%CI±0.40) in the 1st trimester and -0.68 days (95%CI±0.68) in the 2nd/3rd trimesters. Also compared to HSUM, the Clarius PUM had a mean difference of 0.47 days (95%CI±0.64) in the 1st trimester and -1.67 days (95%CI±0.43) in the 2nd/3rd trimesters. ICCs were 0.989 or greater throughout. Increasing gestational age was associated with increasing error and absolute error. Both PUM devices demonstrated a modest trend toward underestimation of EGA at advancing gestational ages in 2nd/3rd trimester scans, compared to HSUM.

CONCLUSION

Both the Butterfly iQ and Clarius C3 PUM devices were highly accurate in performing fetal biometry in a diverse population from the US and Zambia. This article is protected by copyright. All rights reserved.

Imaging characteristics of idiopathic scleroma: a retrospective case series and review of the literature

BACKGROUND

Idiopathic scleroma (previously coined solitary idiopathic choroiditis or focal scleral nodule) is an innocuous lesion affecting the sclera with intraocular manifestations. It is often the basis of many misdiagnoses such as amelanotic choroidal melanoma, osteoma or metastatic lesions. Patients are often asymptomatic and the course is benign. With increasing use of community based imaging, more of such cases are being identified. This paper is a retrospective case series investigating the multi-modal imaging findings of idiopathic scleroma.

METHODS

A retrospective analysis of prospectively collected data were analysed. Over the course of January 2008-January 2022, 44 patients diagnosed with idiopathic scleroma and imaged with wide-field colour fundus photography, fundus autofluorescence, ocular coherence tomography (OCT) and B-scan ultrasonography. Due to a poor image, only 43 images were included for OCT review. We also reviewed our patient's demographics, symptoms and baseline ophthalmic characteristics upon presentation.

RESULTS

The mean age was 52 years (range 32-79) and there was no predilection towards gender. All lesions were post equatorial with the most common location being inferotemporal (n = 16, 36%); 32 lesions (73%) were yellow on fundus photography. 82% (n = 36/44) of lesions exhibited hyperautoflourescence and 43 lesions (98%) showed hyperechogenicity on B-scan ultrasonography. 100% of lesions originated from the sclera with no lesions showing active inflammation. 20 (47%) lesions had associated blood vessels overlying them on OCT.

DISCUSSION

Idiopathic scleroma is a yellow, hyperautofluorescent, hyperechogeneic scleral lesion that has no signs of active inflammation. These characteristics help define them from other more sinister cause of amelanotic fundal lesions.

Well-differentiated gastroenteropancreatic G3 NET: findings from a large single centre cohort

Neuroendocrine neoplasms are known to have heterogeneous biological behavior. G3 neuroendocrine tumours (NET G3) are characterized by well-differentiated morphology and Ki67 > 20%. The prognosis of this disease is understood to be intermediate between NET G2 and neuroendocrine carcinoma (NEC). Clinical management of NET G3 is challenging due to limited data to inform treatment strategies. We describe clinical characteristics, treatment, and outcomes in a large single centre cohort of patients with gastroenteropancreatic NET G3. Data was reviewed from 26 cases managed at Queen Elizabeth Hospital, Birmingham, UK, from 2012 to 2019. Most commonly the site of the primary tumour was unknown and majority of cases with identifiable primaries originated in the GI tract. Majority of cases demonstrated somatostatin receptor avidity. Median Ki67 was 30%, and most cases had stage IV disease at diagnosis. Treatment options included surgery, somatostatin analogs (SSA), and chemotherapy with either platinum-based or temozolomide-based regimens. Estimated progression free survival was 4 months following initiation of SSA and 3 months following initiation of chemotherapy. Disease control was observed following treatment in 5/11 patients treated with chemotherapy. Estimated median survival was 19 months; estimated 1 year survival was 60% and estimated 2 year survival was 13%. NET G3 is a heterogeneous group of tumours and patients which commonly have advanced disease at presentation. Prognosis is typically poor, though select cases may respond to treatment with SSA and/or chemotherapy. Further study is needed to compare efficacy of different treatment strategies for this disease.

Structural brain lesions in schizophrenia -magnetic resonance imaging on a mid field magnet

Objectives : The brain damage associated with schizophrenia has been established beyond doubt; however, what remains unexplored is the biological nature of transcultural variations. An important reason for this was the lack of mid and high field scanners in developing countries like India. Material and Methods : We undertook a pilot study using a 0.5 Tesla MRI scanner (General Electric Signa Contour) to explore identifiable structural brain lesions in ten randomly selected individuals with schizophrenia. Results: Nine of the ten participants in the series had structural brain changes. The most common findings were ventricular dilatation and prominent cerebral cortical sulci and cerebellar folia. Additionally non-focal white matter lesions were observed in three patients and small right hippocampus was noted in one participant. Conclusions : The study discusses that establishing structural brain lesions with mid field scanners is indeed feasible. The small study sample and heterogeneity of schizophrenia however made it difficult to establish any definite associations

75 Treatment Escalation Plan (TEP) Completion Rates in General Surgery

Background

TEPs ensure every patient has a ceiling of care formally documented, including a DNACPR decision. This pre-empts complications and provides guidance on how to appropriately manage acutely unwell patients. There is no national standard for TEPs. Our aim: to formally document the incidence of TEP completion in general surgery at a local District General Hospital.

Method

A multi-phase, cross-sectional study of 1. Inpatients on three general surgical wards, 2. TEP completion at post-take after a typical on-call cycle.

Results

15.4% of TEPs were completed, of which 75% had a DNARCPR form. For the two post-take ward rounds, 5% and 7.7% of admitted patients had a TEP. Elective surgical/Enhanced recovery patients (ERP) did not have a TEP. Findings were presented locally, and posters placed in the surgical offices. Cycle 2: 19.6% and 10% completion rate for ward and post-take patients, respectively.

Conclusions

TEPs are rarely completed. Minimal improvement in completion rate was noted at cycle 2. TEPs are more commonly completed for patients not for resuscitation. Future aims include editing the surgical clerking proforma and the elective surgery/ERP paperwork to encourage completion, improving patient care. Currently we are arranging similar audits across other NHS trusts to determine if this is a national problem.

Comparison of pulmonary vein sizing by transesophageal echocardiogram and by direct angiogram

Funding Acknowledgements

Type of funding sources: None.

Background

Pulmonary vein (PV) anatomy and sizing is important to know before performing PV isolation. This information is conventionally obtained by angiography or by CT scan.

Aim

We undertook this study to identify and measure the PVs during TEE studies and validate these against angiography.

Method

17 consecutive patients due to undergo PV isolation for paroxysmal atrial fibrillation were analysed. Using TEE, the PVs were visualised (Upper panel) as follows:  i) From the mid-esophageal four chamber view, the chamber probe was turned to the right at 110-130º for the bicaval view, where the RSPV was seen entering the left atrium adjacent to the SVC. ii) At 0º the SVC was imaged in its short axis, and the probe advanced till the interatrial septum was seen. The angle was changed to 30º to visualise the right inferior PV (RIPV). iii) From the two chamber view (70-90º), the probe was turned to the left and withdrawn to display the left superior PV (LSPV) entering the left atrium parallel to the appendage.iv) Keeping the LSPV in focus, the angle was changed to 135º and the probe advanced till the AV groove, where the left inferior PV (LIPV) was visualised. After transseptal puncture, each PV was cannulated. The PV angiograms were performed in several projections to obtain the best PV profile (lower panel). Using electronic callipers, each PV was measured within 1 cm of its entry into the left atrium, after having received all tributaries. Those PVs were considered for analysis which were measured by both TEE and angiography. The paired ‘T’ test was used to compare the PV diameters by TEE and angiography and the Bland Altman analysis was done to see the level of agreement.

Results

Of a total of 68 PVs, 62 could be adequately visualised by TEE and 50 by angiography. These 50 PVs were measured using both methods. The diameters of the PVs measured by TEE and angiography were not statistically different by the paired t test; LSPV14 ± 1.8 mm v/s 14.4 ± 2.1 mm; RSPV 13 ± 1.8 mm v/s 14.6 ± 3.5 mm; LIPV 11.9 ± 2.1 vs 13.2 ± 2.8 mm and RIPV 10.5 ± 2.7 vs 12.1 ± 2.9 mm. Bland Altman analysis showed most PV sizes estimated by TEE and angiography lay within limits of agreement.

Conclusions

A majority of PVs can be visualised by TEE using a defined protocol. TEE is a good technique to visualise and assess the size of PVs, avoiding the need for contrast medium and radiation.

Abstract Figure. TEE and angiographic images of PVs

Social network analysis of COVID-19 transmission in Karnataka, India

We used social network analysis (SNA) to study the novel coronavirus (COVID-19) outbreak in Karnataka, India, and to assess the potential of SNA as a tool for outbreak monitoring and control. We analysed contact tracing data of 1147 COVID-19 positive cases (mean age 34.91 years, 61.99% aged 11-40, 742 males), anonymised and made public by the Karnataka government. Software tools, Cytoscape and Gephi, were used to create SNA graphics and determine network attributes of nodes (cases) and edges (directed links from source to target patients). Outdegree was 1-47 for 199 (17.35%) nodes, and betweenness, 0.5-87 for 89 (7.76%) nodes. Men had higher mean outdegree and women, higher mean betweenness. Delhi was the exogenous source of 17.44% cases. Bangalore city had the highest caseload in the state (229, 20%), but comparatively low cluster formation. Thirty-four (2.96%) 'super-spreaders' (outdegree ⩾ 5) caused 60% of the transmissions. Real-time social network visualisation can allow healthcare administrators to flag evolving hotspots and pinpoint key actors in transmission. Prioritising these areas and individuals for rigorous containment could help minimise resource outlay and potentially achieve a significant reduction in COVID-19 transmission.

P636 A unique case of purulent pericarditis resulting in cardiac tamponade

Introduction and case report description

A 54-year-old male with no past cardiac disease was experiencing a productive cough, fevers, chills, and shortness of breath for 3 days in the community. His dyspnea worsened significantly, and he then presented to the emergency room. He admitted to using intravenous recreational drugs. His initial vital signs included a temperature of 38.2 degrees Celsius, a heart rate of 116 beats per minute, and a blood pressure of 88/42 mmHg. He had a positive pulses paradoxus with a decrease in systolic blood pressure of 14 mmHg on inspiration.

Description of the problem and procedures

This presentation was consistent with cardiac tamponade. He had an emergent echocardiogram showing a large pericardial effusion in the apical-four-chamber view (Image 1, A), including collapse of the right ventricle during diastole (Image 1, B, Green Arrow). There were also fibrin strands seen in a modified parasternal long axis view (Image 1, C, Blue Arrow). He had an emergency pericardiocentesis using real-time ultrasound guidance, which drained 400 mL of thick brown purulent fluid. A pigtail catheter was inserted to allow for continued drainage. Immediately afterwards, the patient’s blood pressure normalized, and his shortness of breath improved significantly.

Using the ultrasound, the physician also saw bilateral pleural effusions. The larger left pleural effusion was drained, and a pigtail catheter was inserted into the left pleural space. After confirming that there was no post-procedure left pneumothorax, the right pleural effusion was also drained.

An echocardiogram after the pericardiocentesis showed a significant decrease in the size of the pericardial effusion (Image 1, D).

The patient was started on broad-spectrum antibiotics, which was then narrowed after cultures from both the pericardial fluid and pleural fluid grew methicillin-susceptible Staphylococcus aureus.

Discussion

Cardiac tamponade results in increased compression of the cardiac chambers due to raised pericardial pressures. As it progresses, it can result in significant impairment in venous return, cardiac output, and blood pressure. This is a life-threatening condition if it is not promptly treated. In this case, the patient had a methicillin-susceptible Staphylococcus aureus empyema which spread contiguously into the pericardium and resulted in cardiac tamponade.

Conclusions and implications for clinical practice

This case highlights the clinical benefits of being proficient in performing a point-of-care ultrasound because a bedside echocardiogram by the physician immediately confirmed the diagnosis and allowed for safer drainage of the pericardial effusion using ultrasound guidance to decrease the chance of causing a perforation of the ventricle. Using ultrasound, the clinician was also able to promptly diagnose the pleural effusions and urgently drain them, which was necessary for achieving source control in order to fully treat the infection.

Abstract P636 Figure. Image 1. Cardiac Tamponade

A review of skeletal dysplasia research in India

We aimed to review the contributions by Indian researchers to the subspecialty of skeletal dysplasias (SDs). Literature search using specific keywords in PubMed was performed to retrieve all the published literature on SDs as on July 6, 2017. All published literature on SDs wherein at least one author was from an Indian institute was included. Publications were grouped into different categories based on the major emphasis of the research paper. Five hundred and forty publications in English language were retrieved and categorized into five different groups. The publications were categorized as reports based on: (i) phenotypes (n = 437), (ii) mutations (n = 51), (iii) novel genes (n = 9), (iv) therapeutic interventions (n = 31), and (v) reviews (n = 12). Most of the publications were single-patient case reports describing the clinical and radiological features of the patients affected with SDs (n = 352). We enlisted all the significant Indian contributions. We have also highlighted the reports in which Indians have contributed to discovery of new genes and phenotypes. This review highlights the substantial Indian contributions to SD research, which is poised to reach even greater heights given the size and structure of our population, technological advances, and expanding national and international collaborations.

Seven additional families with spondylocarpotarsal synostosis syndrome with novel biallelic deleterious variants in FLNB

The location and/or type of variants in FLNB result in a spectrum of osteochondrodysplasias ranging from mild forms, like spondylocarpotarsal synostosis syndrome and Larsen syndrome, to severe perinatal lethal forms, such as atelosteogenesis I and III and Boomerang dysplasia. Spondylocarpotarsal synostosis syndrome is characterized by disproportionate short stature, vertebral anomalies and fusion of carpal and tarsal bones. Biallelic loss-of-function variants in FLNB are known to cause spondylocarpotarsal synostosis syndrome and 9 families and 9 pathogenic variants have been reported so far. We report clinical features of 10 additional patients from 7 families with spondylocarpotarsal synostosis syndrome due to 7 novel deleterious variants in FLNB, thus expanding the clinical and molecular repertoire of spondylocarpotarsal synostosis syndrome. Our report validates key clinical (fused thoracic vertebrae and carpal and tarsal coalition) and molecular (truncating variants in FLNB) characteristics of this condition.

Alpha galactosidase A activity in Parkinson's disease

Glucocerebrosidase (GCase, deficient in Gaucher disease) enzymatic activity measured in dried blood spots of Parkinson's Disease (PD) cases is within healthy range but reduced compared to controls. It is not known whether activities of additional lysosomal enzymes are reduced in dried blood spots in PD. To test whether reduction in lysosomal enzymatic activity in PD is specific to GCase, we measured GCase, acid sphingomyelinase (deficient in Niemann-Pick disease types A and B), alpha galactosidase A (deficient in Fabry), acid alpha-glucosidase (deficient in Pompe) and galactosylceramidase (deficient in Krabbe) enzymatic activities in dried blood spots of PD patients (n = 648) and controls (n = 317) recruited from Columbia University. Full sequencing of glucocerebrosidase (GBA) and the LRRK2 G2019S mutation was performed. Enzymatic activities were compared between PD cases and controls using t-test and regression models adjusted for age, gender, and GBA and LRRK2 G2019S mutation status. Alpha galactosidase A activity was lower in PD cases compared to controls both when only non-carriers were included (excluding all GBA and LRRK2 G2019S carriers and PD cases with age-at-onset below 40) [2.85 μmol/l/h versus 3.12 μmol/l/h, p = 0.018; after controlling for batch effect, p = 0.006 (468 PD cases and 296 controls)], and when including the entire cohort (2.89 μmol/l/h versus 3.10 μmol/l/h, p = 0.040; after controlling for batch effect, p = 0.011). Because the alpha galactosidase A gene is X-linked, we stratified the analyses by sex. Among women who were non-carriers of GBA and LRRK2 G2019S mutations (PD, n = 155; control, n = 194), alpha galactosidase A activity was lower in PD compared to controls (2.77 μmol/l/h versus 3.10 μmol/l/h, p = 0.044; after controlling for a batch effect, p = 0.001). The enzymatic activity of acid sphingomyelinase, acid alpha-glucosidase and galactosylceramidase was not significantly different between PD and controls. In non-carriers, most lysosomal enzyme activities were correlated, with the strongest association in GCase, acid alpha-glucosidase, and alpha galactosidase A (Pearson correlation coefficient between 0.382 and 0.532). In a regression model with all five enzymes among non-carriers (adjusted for sex and age), higher alpha galactosidase A activity was associated with lower odds of PD status (OR = 0.54; 95% CI:0.31-0.95; p = 0.032). When LRRK2 G2019S PD carriers (n = 37) were compared to non-carriers with PD, carriers had higher GCase, acid sphingomyelinase and alpha galactosidase A activity. We conclude that alpha galactosidase A may have a potential independent role in PD, in addition to GCase.

Role of Central Corneal Thickness on Baseline Parameters and Progression of Visual Fields in Open Angle Glaucoma

Purpose

To evaluate the relationship of central corneal thickness (CCT) to baseline visual field parameters and visual field progression in patients with primary open-angle glaucoma (POAG).

Methods

Charts of consecutive patients with POAG were reviewed to obtain visual field data. Visual field was measured by standard threshold static perimetry. Variables analyzed included mean deviation (MD) and pattern standard deviation (PSD).

Results

A total of 121 eyes examined over 4 years were evaluated. A significant negative relationship between CCT and PSD (correlation coefficient: −0.02, p<0.05) was found. Analyses comparing CCT to change in PSD and MD (visual field progression) were statistically not significant.

Conclusions

Patients with thinner corneas initially present with a greater visual field defect, indicating that thin corneas may contribute to advanced glaucomatous damage at the time of diagnosis. However, CCT does not seem to be a significant risk factor for progression of the disease.

Neurenteric cyst of the conus medullaris

Background:

Neurenteric cysts (NECs) are rare developmental malformations of the central nervous system (CNS) which originate as benign congenital lesions. They originate from developmental foregut precursors, and are presumed to be the result of abnormal partitioning of the embryonic notochord plate. Such NECs predominantly arise in the cervical region in patients around 6 years of age or in their twenties or thirties. Notably, NECs of the conus medullaris are exceedingly rare, especially in patients of advanced age.

Case Description:

A 70-year-old male presented with bilateral upper thigh and leg pain of over 20 years duration. His pain worsened over the past 3 years, and he sought surgical management. Although his neurological exam was normal, the lumbar magnetic resonance imaging revealed an intradural, nonenhancing, thin-walled, cystic lesion at L1/conus medullaris. The lesion was successfully resected without any adverse sequelae.

Conclusions:

NECs are rare congenital legions that involve the spine. Here, an L1 intradural extramedullay neuroenteric cyst of the conus medullaris was resected without complications.

Post-prophylaxis Toxoplasma chorioretinitis following donor-recipient mismatched liver transplantation

Toxoplasmosis may be transferred by organ transplantation. The most common clinical presentation is with multisystem disease, although isolated ocular toxoplasmosis has been described. Many centers have suggested that universal use of co-trimoxazole prophylaxis obviates the need for specific Toxoplasma testing. We report a case of donor-acquired ocular toxoplasmosis after liver transplantation despite co-trimoxazole prophylaxis. The diagnosis was confirmed by Toxoplasma polymerase chain reaction assay in conjunction with seroconversion. The fact that the infection was donor acquired was confirmed by serological mismatch and the absence of sporozoite-specific antigen antibody in the recipient.

Second family provides further evidence for causation of Steel syndrome by biallelic mutations in COL27A1

Steel syndrome is a rare disorder of the skeleton characterized by facial dysmorphism, short stature, carpal coalition, dislocated radial heads, bilateral hip dislocation and vertical talus. Homozygous variants in COL27A1 were reported in an extending family from Puerto Rico. Here, we report a 5-year-old girl from a non-consanguineous family with facial dysmorphism, short stature, carpal coalition, dislocation of radial heads, bilateral hip dislocation, scoliosis and vertical talus. Exome sequencing identified 2 novel compound heterozygous variants c.521_528del (p.(Cys174Serfs*34)) and c.2119C>T (p.(Arg707*)) in COL27A1 in this child and the parents were heterozygous carriers. We hence report the second molecularly proven case of Steel syndrome and the first case to be reported among non-Puerto Rican population. Our report further validates the role of COL27A1 mutations in causation of Steel syndrome.

Young onset colorectal cancer: How does it differ from its older counterpart?

BACKGROUND

Colorectal cancer in the young has been a debated topic in literature with conflicting reports as to its pattern of occurrence and survival as compared to the older age group.

MATERIALS AND METHODS

Retrospective study to analyze the clinicopathological characteristics, treatment modalities and survival of sporadic young-onset colorectal cancer (YOCR) patients (<40 years) and compare them with the older group (>40 years).

RESULTS

Of 172 patients managed, 72 (42%) were in the YOCR group. Among 72 patients, six were excluded because of hereditary syndromes. Incontinence (P = 0.02) and obstruction at time of presentation (P = 0.03) was significantly more common in the YOCR group. Left sided disease was more common in YOCR group (47/66) compared to the older group (65/100), but the difference was not statistically significant (P = 0.45). The proportion of rectal cancers was significantly more in the YOCR group (39/47) compared to the older group (39/65) (P = 0.01). Significant difference in resectability was noted in the left sided (YOCR 26/47 vs. older 49/65 P = 0.04) and the rectal cancers (YOCR 18/39 vs. Older 29/39 P = 0.02). The survival was similar among the two groups.

CONCLUSIONS

Sporadic colorectal cancers in the young are more advanced and less resectable when compared to older population. Genetic studies are needed to elaborate the reasons for left sided predominance and aggressiveness of sporadic colorectal cancers in the younger subgroups.

Characterization of a biologically derived rabbit tracheal scaffold

There is a clinical need to provide replacement tracheal tissue for the pediatric population affected by congenital defects, as current surgical solutions are not universally applicable. A potential solution is to use tissue engineered scaffold as the framework for regenerating autologous tissue. Rabbit trachea were used and different detergents (Triton x-100 and sodium deoxycholate) and enzymes (DNAse/RNAse) investigated to create a decellularization protocol. Each reagent was initially tested individually and the outcome used to design a combined protocol. At each stage the resultant scaffold was assessed histologically, molecularly for acellularity and matrix preservation. Immunogenicity of the final scaffold was assessed by implantation into a rat model for 4 weeks. Both enzymes and detergents were required to produce a completely acellular (DNA content 42.78 ng/mg) scaffold with preserved collagen and elastin however, GAG content were reduced (8.78 ± 1.35 vs. 5.5 ± 4.8). Following in vivo implantation the scaffold elicited minimal immune response and showed significant cellular infiltration and vasculogenesis. The luminal aspect of the implanted scaffold showed infiltration of host derived cells, which were positive for pan cytokeratin. It is possible to create biologically derived biocompatible scaffolds to address specific pediatric clinical problems. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 2126-2135, 2017.

Efficient use of artificial micro-RNA to downregulate the expression of genes at the post-transcriptional level in Arabidopsis thaliana

Micro-RNAs are cellular components regulating gene expression at the post-transcription level. In the present study, artificial micro-RNAs were used to decrease the transcript level of two genes, AtExpA8 (encoding an expansin) and AHL25 (encoding an AT-hook motif nuclear localized protein) in Arabidopsis thaliana. The backbone of the Arabidopsis endogenous MIR319a micro-RNA was used in a site-directed mutagenesis approach for the generation of artificial micro-RNAs targeting two genes. The recombinant cassettes were expressed under the control of the CaMV 35S promoter in individual A. thaliana plants. Transgenic lines of the third generation were tested by isolating total RNA and by subsequent cDNA synthesis using oligo-dT18 primers and mRNAs as templates. The expression of the two target genes was checked through quantitative real-time polymerase chain reaction to confirm reduced transcript levels for AtExpA8 and AHL25. Downregulation of AtExpA8 resulted in the formation of short hypocotyls compared with those of the wild-type control in response to low pH and high salt concentration. This technology could be used to prevent the expression of exogenous and invading genes posing a threat to the normal cellular physiology of the host plant.