Bench-to-bedside imaging in brain metastases: a road to precision oncology

Radiology has seen tremendous evolution in the last few decades. At the same time, oncology has made great strides in diagnosing and treating cancer. Distant metastases of neoplasms are being encountered more often in light of longer patient survival due to better therapeutic strategies and diagnostic methods. Brain metastasis (BM) is a dismal manifestation of systemic cancer. In the present scenario, magnetic resonance imaging (MRI), computed tomography (CT) and positron emission tomography (PET) are playing a big role in providing molecular information about cancer. Lately, molecular imaging has emerged as a stirring arena of dynamic imaging techniques that have enabled clinicians and scientists to noninvasively visualize and understand biological processes at the cellular and molecular levels. This knowledge has impacted etiopathogenesis, detection, personalized treatment, drug development, and our understanding of carcinogenesis. This article offers insight into the molecular biology underlying brain metastasis, its pathogenesis, imaging protocols, and algorithms. It also discusses disease-specific molecular imaging features, focusing on common tumors that spread to the brain, such as lung, breast, colorectal cancer, melanoma, and renal cell carcinoma. Additionally, it covers various targeted treatment options, criteria for assessing treatment response, and the role of artificial intelligence in diagnosing, managing, and predicting prognosis for patients with brain metastases.

Calcium dysregulation combined with mitochondrial failure and electrophysiological maturity converge in Parkinson's iPSC-dopamine neurons

Parkinson's disease (PD) is characterized by a progressive deterioration of motor and cognitive functions. Although death of dopamine neurons is the hallmark pathology of PD, this is a late-stage disease process preceded by neuronal dysfunction. Here we describe early physiological perturbations in patient-derived induced pluripotent stem cell (iPSC)-dopamine neurons carrying the GBA-N370S mutation, a strong genetic risk factor for PD. GBA-N370S iPSC-dopamine neurons show an early and persistent calcium dysregulation notably at the mitochondria, followed by reduced mitochondrial membrane potential and oxygen consumption rate, indicating mitochondrial failure. With increased neuronal maturity, we observed decreased synaptic function in PD iPSC-dopamine neurons, consistent with the requirement for ATP and calcium to support the increase in electrophysiological activity over time. Our work demonstrates that calcium dyshomeostasis and mitochondrial failure impair the higher electrophysiological activity of mature neurons and may underlie the vulnerability of dopamine neurons in PD.

Evaluation of prognostic risk models for postoperative pulmonary complications in adult patients undergoing major abdominal surgery: a systematic review and international external validation cohort study

BACKGROUND

Stratifying risk of postoperative pulmonary complications after major abdominal surgery allows clinicians to modify risk through targeted interventions and enhanced monitoring. In this study, we aimed to identify and validate prognostic models against a new consensus definition of postoperative pulmonary complications.

METHODS

We did a systematic review and international external validation cohort study. The systematic review was done in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We searched MEDLINE and Embase on March 1, 2020, for articles published in English that reported on risk prediction models for postoperative pulmonary complications following abdominal surgery. External validation of existing models was done within a prospective international cohort study of adult patients (≥18 years) undergoing major abdominal surgery. Data were collected between Jan 1, 2019, and April 30, 2019, in the UK, Ireland, and Australia. Discriminative ability and prognostic accuracy summary statistics were compared between models for the 30-day postoperative pulmonary complication rate as defined by the Standardised Endpoints in Perioperative Medicine Core Outcome Measures in Perioperative and Anaesthetic Care (StEP-COMPAC). Model performance was compared using the area under the receiver operating characteristic curve (AUROCC).

FINDINGS

In total, we identified 2903 records from our literature search; of which, 2514 (86·6%) unique records were screened, 121 (4·8%) of 2514 full texts were assessed for eligibility, and 29 unique prognostic models were identified. Nine (31·0%) of 29 models had score development reported only, 19 (65·5%) had undergone internal validation, and only four (13·8%) had been externally validated. Data to validate six eligible models were collected in the international external validation cohort study. Data from 11 591 patients were available, with an overall postoperative pulmonary complication rate of 7·8% (n=903). None of the six models showed good discrimination (defined as AUROCC ≥0·70) for identifying postoperative pulmonary complications, with the Assess Respiratory Risk in Surgical Patients in Catalonia score showing the best discrimination (AUROCC 0·700 [95% CI 0·683-0·717]).

INTERPRETATION

In the pre-COVID-19 pandemic data, variability in the risk of pulmonary complications (StEP-COMPAC definition) following major abdominal surgery was poorly described by existing prognostication tools. To improve surgical safety during the COVID-19 pandemic recovery and beyond, novel risk stratification tools are required.

FUNDING

British Journal of Surgery Society.

The Role of Mitochondria-Linked Fatty-Acid Uptake-Driven Adipogenesis in Graves Orbitopathy

CONTEXT

Depot-specific expansion of orbital adipose tissue (OAT) in Graves orbitopathy (GO; an autoimmune condition producing proptosis, visual impairment and reduced quality of life) is associated with fatty acid (FA)-uptake-driven adipogenesis in preadipocytes/fibroblasts (PFs).

OBJECTIVE

This work sought a role for mitochondria in OAT adipogenesis in GO.

METHODS

Confluent PFs from healthy OAT (OAT-H), OAT from GO (OAT-GO) and white adipose tissue in culture medium compared with culture medium containing a mixed hormonal cocktail as adipogenic medium (ADM), or culture-medium containing FA-supplementation, oleate:palmitate:linoleate (45:30:25%) with/without different concentration of mitochondrial biosubstrate adenosine 5'-diphosphate/guanosine 5'-diphosphate (ADP/GDP), AICAR (adenosine analogue), or inhibitor oligomycin-A for 17 days. Main outcome measures included oil-red-O staining and foci count of differentiated adipocytes for in vitro adipogenesis, flow cytometry, relative quantitative polymerase chain reaction, MTS-assay/106 cells, total cellular-ATP detection kit, and Seahorse-XFe96-Analyzer for mitochondria and oxidative-phosphorylation (OXPHOS)/glycolysis-ATP production analysis.

RESULTS

During early adipogenesis before adipocyte formation (days 0, 4, and7), we observed OAT-specific cellular ATP production via mitochondrial OXPHOS in PFs both from OAT-H and OAT-GO, and substantially disrupted OXPHOS-ATP/glycolysis-ATP production in PFs from OAT-GO, for example, a 40% reduction in OXPHOS-ATP and trend-increased glycolysis-ATP production on days 4 and 7 compared with day 0, which contrasted with the stable levels in OAT-H. FA supplementation in culture-medium triggered adipogenesis in PFs both from OAT-H and OAT-GO, which was substantially enhanced by 1-mM GDP reaching 7% to 18% of ADM adipogenesis. The FA-uptake-driven adipogenesis was diminished by oligomycin-A but unaffected by treatment with ADP or AICAR. Furthermore, we observed a significant positive correlation between FA-uptake-driven adipogenesis by GDP and the ratios of OXPHOS-ATP/glycolysis-ATP through adipogenesis of PFs from OAT-GO.

CONCLUSION

Our study confirmed that FA uptake can drive OAT adipogenesis and revealed a fundamental role for mitochondria-OXPHOS in GO development, which provides potential for therapeutic interventions.

Collective Imagining: The Early Genesis and Development of a sense of Collectiveness during Infancy

On entering formal education, infants face the demand of participating in collective educational rou¬tines and learning experiences. However, in this age period, the sense of collectiveness is still in an embry¬onic form. This study explored how infants enter into and experience the need for collectiveness and how teachers create the conditions for the development of a sense of collectiveness during infancy. Our educa¬tional experiment drew on a Conceptual PlayWorld, as a collective model of practice for the development of play and imagination. Thirteen infants (0,5—2 years old) participated in the study. Visual methods were used for digital data collection and analysis. It was found that, being in the imaginary situation as play part¬ners, teachers introduced to the infants’ environment the demand to align with the collective, consistently facilitated and sustained infants’ motive orientation to the collective. The use of props, the embodiment of the experience and the shift from physical objects and concrete spaces to a shared intellectual and abstract space appeared to be critical. The findings inform everyday practice and policy opening up a new area of understanding about the concept of collective imagining, as an important concept for the development of a collective orientation for infants.

Methodological Challenges of Studying Children in a Living Laboratory: Case example of Conceptual PlayLab

Digital technologies have created possibilities in research unavailable when Vygotsky first introduced his cultural-historical approach for studying children’s development. More needs to be known about the relations between methodology and method when using digital tools in the early developmental period (1-5 years). In this paper we introduce the concept of a living laboratory to capture the research dynamics of this cultural age period in family homes and preschool settings under conditions of an educational experiment. We discuss Vygotsky’s theoretical concepts as foundational for theorising the use of digital tools for researching in a living laboratory. Central for a living laboratory are: (1) capturing development in motion, (2) including the past in the present research context, (3) designing studies in ways that go beyond fossilised complete forms of development, and (4) creating study conditions for condensed and amplified forms of development. To bring these conditions into the research contexts where a condensed form of development emerges opens up a dynamic yet dialectical way of studying early development. We showcase digital tools, such as VR and digital data collection, as part of (1) undertaking an educational experiment of a Conceptual PlayWorld, and (2) a cultural-historical conception of longitudinal research for studying the conceptual development of infants, toddlers and preschoolers within a living laboratory.

Three-Port versus Four-Port Laparoscopic Cholecystectomy: A Randomized Controlled Trial

 Laparoscopic cholecystectomy (LC) is one of the most common surgery performed and is traditionally performed using four ports. With the aim of improving patient’s comfort, port numbers have been reduced to single port. But feasibility and the extra expense that comes with single and double port LC has made them less attractive. Three port LC can be a safe alternative to four port LC, and various research has shown its safety. This study compares the three port LC with the traditional four port LC with the objective of assessing feasibility and benefit of the decreased port number. We evaluated 217 patients who were randomly allocated for three port and four port LC. Both the groups were compared for operative time, assessment of postoperative pain, days of hospital stay and postoperative recovery time after discharge. The parameters were compared using Statistical Package for the Social Sciences (SPSS) version 16. Among 217 patients, 123 underwent three port LC and 94 underwent four port LC. The larger number were females (79.7%), and with comparable age group of patients. Rate of conversion to open cholecystectomy, postoperative pain scale, analgesic requirement, average hospital stay and port site infection rates were comparable in both groups of patients. The average time taken for operation was less in three port LC than the four port LC but this was not statistically significant. There is no significant difference between 3 port and 4 port LC in terms of time required for the surgery, conversion rate, complication and duration of hospital stay.

Mini-implant-supported twin-block appliance: An innovative modification

Twin block is a commonly used appliance for correction of retrognathic mandible in growing patients. However, it has a drawback of causing lower incisor proclination, which reduces its potential of achieving maximum skeletal effects. Thus, we introduced a novel modification in the present design to facilitate greater anteroposterior effects in skeletal dimension. The aim of the present case reports is to evaluate the efficacy of this modified twin block. Here we present two cases treated with mini-implant-supported twin-block appliance, which successfully controlled the lower incisor position, thereby increasing the envelope for orthopedic correction in class II myofunctional therapy. This modification is useful in growing patients with retruded mandible to achieve maximum skeletal effects.

Medication persistence and risk of fracture among female Medicare beneficiaries diagnosed with osteoporosis

We examined the relationship between persistent osteoporosis medication use and fracture risk among female Medicare beneficiaries diagnosed with osteoporosis using Medicare claims, 2009-2012. Persistent use was associated with reduced risk of fracture and significantly lower total health care costs in the follow-up period. Results were consistent using different analytical methods.

INTRODUCTION

This study aimed to examine the relationship between medication persistence and fracture risk among female Medicare beneficiaries diagnosed with osteoporosis.

METHODS

Elderly female Medicare beneficiaries diagnosed with osteoporosis and initiated on osteoporosis medication January 1, 2009-June 30, 2011, were included. Persistent medication use was defined as continuous use (no gap ≥ 60 days) for 1 year or longer. The key outcome was fragility fracture. A difference-in-difference analysis was performed at the log scale of fracture rate using a Poisson regression model with months 1-6 before medication initiation as the pre-initiation period and up to 18 months after as the post-initiation period. Total health care costs were compared using a similar approach. Sensitivity analyses were conducted using different pre- and post-initiation periods.

RESULTS

The study included 294,369 patients; 32.9% were persistent osteoporosis medication users and 67.1% non-persistent (< 12 months continuous use). Fracture incidence rates were 16.2 per 100 patient-years pre-initiation and 4.1 post-initiation for persistent users; corresponding rates for non-persistent users were 19.0 and 7.3 per 100 patient-years. The adjusted post-/pre-initiation fracture rate ratios were 0.284 for persistent and 0.411 for non-persistent users. The ratio of the two rate ratios was 0.692 (persistent vs. non-persistent, p < 0.0001), suggesting a significantly greater fracture rate reduction for persistent users. Adjusted cost ratios were significantly lower for persistent users. Sensitivity analyses results were similar.

CONCLUSIONS

Persistent use of osteoporosis medications was associated with reduced risk of fracture and significantly lower total health care costs. Payers and patients would benefit from interventions aimed at improving medication persistence.

Inhibition of WNT signaling attenuates self-renewal of SHH-subgroup medulloblastoma

The SMOOTHENED inhibitor vismodegib is FDA approved for advanced basal cell carcinoma (BCC), and shows promise in clinical trials for SONIC HEDGEHOG (SHH)-subgroup medulloblastoma (MB) patients. Clinical experience with BCC patients shows that continuous exposure to vismodegib is necessary to prevent tumor recurrence, suggesting the existence of a vismodegib-resistant reservoir of tumor-propagating cells. We isolated such tumor-propagating cells from a mouse model of SHH-subgroup MB and grew them as sphere cultures. These cultures were enriched for the MB progenitor marker SOX2 and formed tumors in vivo. Moreover, while their ability to self-renew was resistant to SHH inhibitors, as has been previously suggested, this self-renewal was instead WNT-dependent. We show here that loss of Trp53 activates canonical WNT signaling in these SOX2-enriched cultures. Importantly, a small molecule WNT inhibitor was able to reduce the propagation and growth of SHH-subgroup MB in vivo, in an on-target manner, leading to increased survival. Our results imply that the tumor-propagating cells driving the growth of bulk SHH-dependent MB are themselves WNT dependent. Further, our data suggest combination therapy with WNT and SHH inhibitors as a therapeutic strategy in patients with SHH-subgroup MB, in order to decrease the tumor recurrence commonly observed in patients treated with vismodegib.

Nanoparticle Based Combination Treatments for Targeting Multiple Hallmarks of Cancer

Treatment of cancer remains one of the most challenging tasks facing the healthcare system. Cancer affects the lives of millions of people and is often fatal. Current treatment methods include surgery, chemotherapy, radiation therapies or some combinations of these. However, recurrence is a major problem. These treatments can be invasive with severe side effects. Inefficacies in treatments are a result of the complex and variable biology of cancerous cells. Malignant tumor cells and normal functioning cells share many of the same biological characteristics but the main difference is that in cancer cells there is in an overuse and over expression of these biological characteristics. These pertinent characteristics can be grouped into eight hallmarks, as illustrated by Hanahan and Weinberg. These characteristics include sustaining proliferative signaling, evading growth suppressors, resisting cell death, enabling replicative immortality, inducing angiogenesis, activating invasion and metastasis, reprogramming energy metabolism, and evading immune destruction. In order to provide a noninvasive, effective treatment, delivery methods must be explored in order to transport cytotoxic agents used for targeting the hallmarks of cancer in a safer and more effective fashion. The use of nanoparticles as drug delivery carriers provides an effective method in which multiple cytotoxic agents can be safely delivered to cancer tissue to simultaneously target multiple hallmarks. By targeting multiple hallmarks of cancer at once, the efficacy of cancer treatments could be improved drastically. This review explores the uses and efficacy of combination therapies using nanoparticles that can simultaneously target multiple hallmarks of cancer.

Differential expression of virulence genes and role of gyrA mutations in quinolone resistant and susceptible strains of Salmonella Weltevreden and Newport isolated from seafood

AIMS

To investigate the differential expression of virulence genes and role of gyrA mutations in quinolone resistant and susceptible strains of Salmonella isolated from seafood.

METHODS AND RESULTS

Forty Salmonella isolates from seafood were tested for antibiotic sensitivity. Minimal inhibitory concentration (MIC) was determined and two nalidixic acid-resistant isolates, viz Salmonella Weltevreden (SW9) and Salmonella Newport (SN36) were selected for identifying the mechanism of resistance. SW9 showed mutation in the gyrA gene at codon 83 (Ser to Tyr) while SN36 presented at codon 87 (Asp to Asn). Experimental induction of resistance to a sensitive Salm. Newport (SN71) showed point mutation at codon 87 (Asp to Gly) in the gyrA gene, and was designated SN71R. All the isolates resistant to nalidixic acid had a single mutation at different positions in the gyrA gene. However, induction of resistance to a sensitive Salm. Weltevreden (SW30) was exceptional in that it did not show any mutation in the gyrA region. Use of Phe-Arg-β-naphthylamide (PAβN) also could not reduce MIC below the Clinical and Laboratory Standards Institute guidelines revealing the absence of efflux mediated resistance. Thus, the resistance mechanism in SW30R is unknown. The growth rate of quinolone resistant isolates was slower than the susceptible ones. The resistant isolates showed decreased epithelial cell invasion and intracellular replication. The mRNA expression levels of some of the genes were significantly (P < 0·005) reduced in SN71R compared to the sensitive strain (SN71).

CONCLUSIONS

Nalidixic acid-resistant Salmonella strains are associated with lower virulence and pathogenicity than the sensitive strains.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study provided valuable information on the difference in the growth, cytotoxicity, infectivity and expression of virulence genes in resistant and susceptible strains. Furthermore, the gyrA mutation was shown to be the main mechanism of quinolone resistance in Salmonella other than the overexpression of efflux pumps or the presence of plasmid mediated quinolone resistance genes.

Serum lipid profile in oral squamous cell carcinoma: alterations and association with some clinicopathological parameters and tobacco use

Hypocholesterolemia has been observed in patients with cancers of various organs; however the potential role of alterations in serum lipid profile in oral cancer remains controversial. Hence, this study aimed to evaluate the serum lipid profile in oral squamous cell carcinoma (OSCC) and its prognostic significance. Ninety untreated OSCC patients, who reported to the craniofacial unit for treatment between 2011 and 2014, were identified to obtain clinicopathological data and preoperative blood investigations including lipid profile. The fasting blood lipid profile, including total cholesterol (TC), triglyceride (TG), high density lipoprotein (HDL), and low density lipoprotein (LDL), was evaluated using a fully automated biochemistry analyser. Data were analyzed statistically using the Student's t-test, analysis of variance, and post hoc tests. Statistically significant decreases in serum TC, HDL, and LDL levels were observed in OSCC patients as compared to healthy controls (P<0.05). There was no statistically significant difference in mean lipid profile values in terms of stage, grade, or lymph node metastasis. This study identified changes in lipid profiles in OSCC. The results suggest that during the development and progression of OSCC, levels of serum lipids are decreased. A review of the literature confirmed that OSCC patients exhibit aberrant serum lipid patterns.

Findings on interval colonoscopies: an auditable performance indicator for colonoscopy quality?

OBJECTIVE

An important marker of colonoscopy quality is detection of pathology and incidence of missed pathology. Back-to-back colonoscopies cannot ethically be performed for quality assurance alone yet may be required for clinical reasons. This study aims to investigate the incidence of new findings in colonoscopies repeated within a 12 month period and considers the role of such an analysis in the assessment of colonoscopy quality.

DESIGN

All colonoscopies performed over a 3-year period at an endoscopy training unit were studied. Colonoscopies repeated within a 12-month period were analysed.

RESULTS

5747 colonoscopies were performed over the study period. 137 repeat colonoscopies were included with median interval from initial colonoscopy of 174 days. 19 (14%) repeat colonoscopies yielded new findings including one cancer, 234 days following a normal colonoscopy. Additional polyps were identified in 13 colonoscopies indicating a missed polyp rate of 9%. In these, a median number of two polyps per colonoscopy with median size 5.5 mm were found. There was no morbidity associated with repeat colonoscopy in this series. New findings on repeat colonoscopy appeared more likely following initial colonoscopy by non-consultant non-training grade endoscopists (23% vs 11%, p=0.09) yet small numbers involved preclude meaningful comparison.

CONCLUSIONS

Analysis of clinically indicated repeat colonoscopies and rate of detection of new pathology may offer utility in colonoscopy quality assurance and would offer a direct assessment of the most important aspect of colonoscopy quality.

MutT Homolog 1 (MTH1) maintains multiple KRAS-driven pro-malignant pathways

Oncogenic RAS promotes production of reactive oxygen species (ROS), which mediate pro-malignant signaling but can also trigger DNA damage-induced tumor suppression. Thus RAS-driven tumor cells require redox-protective mechanisms to mitigate the damaging aspects of ROS. Here, we show that MutT Homolog 1 (MTH1), the mammalian 8-oxodGTPase that sanitizes oxidative damage in the nucleotide pool, is important for maintaining several KRAS-driven pro-malignant traits in a nonsmall cell lung carcinoma (NSCLC) model. MTH1 suppression in KRAS-mutant NSCLC cells impairs proliferation and xenograft tumor formation. Furthermore, MTH1 levels modulate KRAS-induced transformation of immortalized lung epithelial cells. MTH1 expression is upregulated by oncogenic KRAS and correlates positively with high KRAS levels in NSCLC human tumors. At a molecular level, in p53-competent KRAS-mutant cells, MTH1 loss provokes DNA damage and induction of oncogene-induced senescence. In p53-nonfunctional KRAS-mutant cells, MTH1 suppression does not produce DNA damage but reduces proliferation and leads to an adaptive decrease in KRAS expression levels. Thus, MTH1 not only enables evasion of oxidative DNA damage and its consequences, but can also function as a molecular rheostat for maintaining oncogene expression at optimal levels. Accordingly, our results indicate MTH1 is a novel and critical component of oncogenic KRAS-associated malignancy and its inhibition is likely to yield significant tumor-suppressive outcomes in KRAS-driven tumors.

To evaluate the role of novel fully covered self-expanding metal stent for endoscopic drainage of infected pancreatic pseudocyst

INTRODUCTION

Endoscopic ultrasonography-guided transgastric drainage of pancreatic pseudocyst (PPC) is the mainstay of treatment. Drainage can be achieved either by plastic stents or fully covered self-expandable metal stent (FCSEMS). Plastic stents have small lumen diameter, which may limit drainage and may necessitate re-intervention. FCSEMS are easier to deploy and preclude the need to place multiple plastic stents.

OBJECTIVE

To evaluate the role of novel FCSEMS for endoscopic drainage of infected PPC.

METHODS

PATIENTS

10 patients with single symptomatic pseudocyst in proximity to the stomach or duodenum and fever were treated. Pseudocyst drainage was done per protocol. Repeat computed tomography scan after 72 h. Nasocystic drain removed after 3-5 days. PATIENTS were followed-up at every 2 week interval. Stent was removed after complete disappearance of pseudocyst confirmed on imaging. Early (7 days) and late (>7 days) complications were noted and managed accordingly.

RESULTS

Technical success and clinical success achieved in all. Early complication: 1/10 (pneumoperitoneum). No late complications observed. Stent were removed without complication after 6-7 week follow-up period ranges from 6 to 8 months.

CONCLUSION

Use of FCSEMS for pseudocyst drainage is technically feasible and safe.

Imaging of peritoneal ligament by endoscopic ultrasound

INTRODUCTION

Double layered peritoneal folds, variously named as ligaments, omenta and mesenteries connect the intraperitoneal organs to the abdominal wall. Some of these ligaments contain blood vessels and lymph nodes while others are avascular. The peritoneal folds not only act as conduits for the passage of blood vessels from the retroperitoneum to reach intraperitoneal organs, but also provide a pathway for the spread of disease processes. It is difficult to identify these normal peritoneal folds at imaging. Computed tomography is the most common imaging modality used to detect diseases of the peritoneum to fully delineate peritoneal anatomy and the extent of disease. The endoscopic ultrasound (EUS) can be used to image peritoneal ligaments with the advantage of lack of ionizing radiation and lower cost. Though EUS is being increasingly used both for diagnostic and interventional purposes in the abdomen, it has not been used to assess the peritoneal ligaments till now.

METHODS

We did this study in 50 patients using linear echo endoscope to delineate various peritoneal ligaments. The technique of evaluation of ligament has been described in this review.

CONCLUSION

The peritoneal ligaments can be delineated with accuracy by EUS.

Presence of T3SS2β genes in trh⁺ Vibrio parahaemolyticus isolated from seafood harvested along Mangalore coast, India

Vibrio parahaemolyticus is a seafood-borne pathogen autochthonous to the marine and estuarine ecosystem, responsible for gastroenteritis when contaminated raw seafood is consumed. The pathogenicity has been associated with thermostable direct haemolysin (TDH) and TDH-related haemolysin (TRH). Of late, the presence of T3SS2α and T3SS2β gene clusters has been well documented in clinical isolates of Vibrio parahaemolyticus and known to play an essential role in pathogenesis. However, reports on the presence of T3SSβ genes in V. parahaemolyticus isolated from the seafood and/or environmental samples are scanty. In this study, we have identified and analysed the distribution of the T3SS2β genes in V. parahaemolyticus isolated from seafood harvested along southwest coast of India. Results showed that T3SS2β genes are solely associated with trh⁺ and tdh⁺ /trh⁺ strains of V. parahaemolyticus. Reverse transcriptase PCR (RT-PCR) showed that the T3SS2β genes identified in trh⁺ V. parahaemolyticus were transcriptionally active. To our knowledge, this study appears to be the first description on the presence of T3SS2β-positive V. parahaemolyticus isolated from seafood in India. The study of T3SS2 along with other virulence factors will help in better understanding of the risk of seafood-borne illness due to V. parahaemolyticus.

SIGNIFICANCE AND IMPACT OF THE STUDY

T3SSs (α or β) are the important virulence factors of Vibrio parahaemolyticus that contribute to their pathogenicity in humans. This study demonstrated the presence of T3SS2β genes in V. parahaemolyticus isolated from the seafood harvested along Mangalore coast. RT-PCR showed that the T3SS2β genes identified in seafood isolates of V. parahaemolyticus were found to be functional. To the best of our knowledge, this is the first description of T3SS2β genes in trh⁺ V. parahaemolyticus isolated from seafood in India. The presence of T3SS2 along with other virulence factors such as TDH and/or TRH highlights a potential health risk for seafood consumers.

Electrical excitation of surface plasmons by an individual carbon nanotube transistor

We demonstrate here the realization of an integrated, electrically driven, source of surface plasmon polaritons. Light-emitting individual single-walled carbon nanotube field effect transistors were fabricated in a plasmonic-ready platform. The devices were operated at ambient conditions to act as an electroluminescence source localized near the contacting gold electrodes. We show that photon emission from the semiconducting channel can couple to propagating surface plasmons developing in the electrical terminals. Our results show that a common functional element can be operated for two different platforms emphasizing thus the high degree of compatibility between state-of-the-art nano-optoelectronics devices and a plasmonic architecture.

Caecal lymphangioma: a rare cause of gastrointestinal blood loss

Lymphangioma is the malformation of the lymphatic system. Lymphangioma is a benign tumour and most colonic lymphangiomas do not cause symptoms and do not require treatment. Resection is required in patients with bleeding or intussusceptions. We report a case of intestinal lymphangiomatosis in a 31-year-old man who presented with recurrent melena and anaemia, which were diagnosed endoscopically and treated with surgical resection.

Psoriatic triad in a patient presenting with oligodontia

Psoriasis is a common dermatological disease. It can occur at any age but usually develops between 15 and 35 years of age and may persist throughout a person's lifetime with periods of exacerbation and remission. The hyperproliferative state of the affected epidermis produces a turnover rate that is up to eight times greater than normal. Instead of being shed, the skin cells pile up, causing the visible lesions. Oral manifestations of psoriasis are rare clinical observations. Lesions have been reported on the lips, buccal mucosa, palate, gingiva, and floor of the mouth. We document a presentation of psoriasis showing a triad: skin lesions, arthritis, and oral manifestations (oligodontia being patient's chief concern). Dental rehabilitation done was in the form of partial dentures. This was done to address the immediate concern of the patient, that is, inability to chew properly. As put forth through this case report, a potential link between psoriasis and oligodontia has scope for further study.

Randomized controlled trial comparing above- and below-elbow plaster casts for distal forearm fractures in children

PURPOSE

Long arm cast is the method of immobilization after closed reduction of the fracture of the distal third of the forearm, although short arm cast has been used to immobilize the forearm by some orthopedic surgeons. We conducted this study to evaluate the rate of displacement, union time, complication, and cost of treatment between the above-elbow and below-elbow plaster cast groups.

METHODS

We designed a prospective randomized controlled trial to compare above- and below-elbow casts for patients of distal forearm fracture aged 4-12 years. One hundred and one patients were presented to our institution during the period from 1st June 2007 to 31st May 2008. Twelve patients were excluded from the study. Eighty-nine patients were randomized into two groups. Four patients were lost to follow up. Hence, 85 patients, 42 in the above-elbow group and 43 in the below-elbow group, were analyzed. Informed consent was obtained prior to participation in the trial. The parameters to be studied were defined before treatment and noted in the pilot-tested pro forma and follow up was done.

RESULTS

Among the 85 patients analyzed, randomization was successful. Pain and swelling on the next day and at one week following cast application was significantly higher (P = 0.000) in the above-elbow group. Three cases in the above-elbow group needed slitting of the plaster cast. Remanipulation was needed more often in the above-elbow group (9.5%). Although the cast index was not statistically significant (P = 0.054) between the groups, those who needed remanipulation had a larger cast index (0.80). The total cost of the treatment and the number of school days lost was significantly higher (P = 0.000) in the above-elbow group.

CONCLUSION

Below-elbow cast treatment was comparable in terms of redisplacement, union time, and movement of the wrist to the above-elbow treatment. The complications rate and total cost was higher in the above-elbow plaster group, which could be a cost benefit if a below-elbow cast is used.

Making the most of Papua New Guinea's biodiversity: Establishment of an integrated set of programs that link botanical survey with pharmacological assessment in "The Land of the Unexpected"

An integrated and coordinated set of programs has been established to meet ICBG goals in Papua New Guinea (PNG). Here we give an overview of the PNG ICBG and focus on the key elements and major steps taken to establish a program necessary for the pharmacological assessment of botanicals and traditional medicines in PNG and, by extrapolation, in other developing countries.

Fly-ash induced synthesis of phytochelatins in chickpea (Cicer arietinum L.) plants

Phytochelatins and related metabolites (cysteine and GSH) were found to be induced in the shoots of two varieties of Cicer arietinum viz., CSG-8962 and C-235 grown under different amendments of fly-ash with garden soil and press mud. Cysteine, GSH, PCs and its speciation were found in higher concentrations in amended fly-ash than in the control 100% soil. Two species of metal binding peptides i.e., PC2 and PC4 were found in both varieties and in amendments, however, their concentration varied depending upon the fly-ash concentrations in both amendments. Further, var. CSG-8962 was found more tolerant than var. C-235 because of higher concentrations of PCs and related metabolites.

Biological aspects of tooth fragment reattachment in immature incisors

Tooth fragment reattachment is a relatively new technique and there are many aspects which still need to be explored. Reported here is a case of enamel and dentin fracture of 11 and 21. There was a very thin layer of dentin clinically over the pulp chamber and the root apices were immature. The reattachment procedure was modified slightly. The initial joint was made with protective calcium hydroxide and glass ionomer cement on the approximating surfaces. The further reattachment was accomplished using composites and acid etch technique. This was done for pulpal protection. After six months, reattachment was intact and successful with no staining, sensitivity or pain. The radiographs revealed root completion of the immature incisors. The reattachment procedure proved to be biologically superior in addition to its esthetic value and psychological advantage.

TREATMENT OF IDIOPATHIC SCOLIOSIS BY HARRINGTON INSTRUMENTATION

An adolescent idiopathic right-sided thoracolumbar scoliosis has been correctedsurgically with Harrington distraction and compression instrumentation with posteriorfusion for the first time in Nepal.Key Words: Idiopathic scoliosis, Harrington system.

Localization of Fe(2+) at an RTGR sequence within a DNA duplex explains preferential cleavage by Fe(2+) and H2O2

Nicking of duplex DNA by the iron-mediated Fenton reaction occurs preferentially at a limited number of sequences. Of these, purine-T-G-purine (RTGR) is of particular interest because it is a required element in the upstream regulatory regions of many genes involved in iron and oxidative-stress responses. In order to study the basis of this preferential nicking, NMR studies were undertaken on the RTGR-containing duplex oligonucleotide, d(CGCGATATGACACTAG)/d(CTAGTGTCATATCGCG). One-dimensional and two-dimensional 1H NMR measurements show that Fe(2+) interacts preferentially and reversibly at the ATGA site within the duplex at a rate that is rapid relative to the chemical-shift timescale, while selective paramagnetic NMR line-broadening of the ATGA guanine H8 suggests that Fe(2+) interacts with the guanine N7 moiety. Localization at this site is supported by Fe(2+) titrations of a duplex containing a 7-deazaguanine substitution in place of the guanine in the ATGA sequence. The addition of a 100-fold excess of Mg(2+) over Fe(2+) does not affect the Fe(2+)-dependent broadening. When the ATGA site in the duplex is replaced by ATGT, an RTGR site (GTGA) is created on the opposite strand. Preferential iron localization then takes place at the 3' guanine in GTGA but no longer at the guanine in ATGT, consistent with the lack of preferential cleavage of ATGT sites relative to ATGA sites.

Orbital myiasis: a case report

Myiasis; a term first introduced by HOPE refers to invasion of living tissue of humans and other mammals by the eggs or larvae of flies of the order of Diptera. Orbital involvement occurs in approximately 5% of all cases of myiasis. A 72 year old patient is presented with orbital myiasis that was successfully treated by enucleation and grafted with split thickness of skin.

In-situ irradiation of keloid scars with Nd:YAG laser

In-situ coagulation of keloid with Nd:YAG laser irradiation was carried out in in a cohort study of 17 patients, each with one keloid scar situated on either the sternum (six), abdomen (seven), shoulder (two), hip (one), or ear lobe (one). The duration of scarring was three to 17 years and size varied from 3-8 cm long. One to two doses of laser irradiation was required for complete coagulation. At three months, 10 (58.8%) keloids had completely healed; but in seven (41.1%), 25-50% of residual keloid persisted. Intralesional triamcinolone injection, once in four patients and twice in three patients, produced complete resolution in all seven patients. At 18 months to five years follow-up, 14 patients remain keloid-free but in three keloid recurred and was re-treated with laser coagulation with complete resolution. The treatment was carried out as an outpatient procedure under local anaesthesia. There were no complications. The results of this initial study suggest that Nd:YAG laser irradiation coagulation is effective treatment for keloid scarring.

Sequence-specific DNA cleavage by Fe2+-mediated fenton reactions has possible biological implications

Preferential cleavage sites have been determined for Fe2+/H2O2-mediated oxidations of DNA. In 50 mM H2O2, preferential cleavages occurred at the nucleoside 5' to each of the dG moieties in the sequence RGGG, a sequence found in a majority of telomere repeats. Within a plasmid containing a (TTAGGG)81 human telomere insert, 7-fold more strand breakage occurred in the restriction fragment with the insert than in a similar-sized control fragment. This result implies that telomeric DNA could protect coding DNA from oxidative damage and might also link oxidative damage and iron load to telomere shortening and aging. In micromolar H2O2, preferential cleavage occurred at the thymidine within the sequence RTGR, a sequence frequently found to be required in promoters for normal responses of many procaryotic and eucaryotic genes to iron or oxygen stress. Computer modeling of the interaction of Fe2+ with RTGR in B-DNA suggests that due to steric hindrance with the thymine methyl, Fe2+ associates in a specific manner with the thymine flipped out from the base stack so as to allow an octahedrally-oriented coordination of the Fe2+ with the three purine N7 residues. Fe2+-dependent changes in NMR spectra of duplex oligonucleotides containing ATGA versus those containing AUGA or A5mCGA were consistent with this model.