The association of GNB5 with Alzheimer disease revealed by genomic analysis restricted to variants impacting gene function

Disease-associated variants identified from genome-wide association studies (GWASs) frequently map to non-coding areas of the genome such as introns and intergenic regions. An exclusive reliance on gene-agnostic methods of genomic investigation could limit the identification of relevant genes associated with polygenic diseases such as Alzheimer disease (AD). To overcome such potential restriction, we developed a gene-constrained analytical method that considers only moderate- and high-risk variants that affect gene coding sequences. We report here the application of this approach to publicly available datasets containing 181,388 individuals without and with AD and the resulting identification of 660 genes potentially linked to the higher AD prevalence among Africans/African Americans. By integration with transcriptome analysis of 23 brain regions from 2,728 AD case-control samples, we concentrated on nine genes that potentially enhance the risk of AD: AACS, GNB5, GNS, HIPK3, MED13, SHC2, SLC22A5, VPS35, and ZNF398. GNB5, the fifth member of the heterotrimeric G protein beta family encoding Gβ5, is primarily expressed in neurons and is essential for normal neuronal development in mouse brain. Homozygous or compound heterozygous loss of function of GNB5 in humans has previously been associated with a syndrome of developmental delay, cognitive impairment, and cardiac arrhythmia. In validation experiments, we confirmed that Gnb5 heterozygosity enhanced the formation of both amyloid plaques and neurofibrillary tangles in the brains of AD model mice. These results suggest that gene-constrained analysis can complement the power of GWASs in the identification of AD-associated genes and may be more broadly applicable to other polygenic diseases.

RIT1 regulation of CNS lipids RIT1 deficiency Alters cerebral lipid metabolism and reduces white matter tract oligodendrocytes and conduction velocities

Oligodendrocytes (OLs) generate lipid-rich myelin membranes that wrap axons to enable efficient transmission of electrical impulses. Using a RIT1 knockout mouse model and in situ high-resolution matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI) coupled with MS-based lipidomic analysis to determine the contribution of RIT1 to lipid homeostasis. Here, we report that RIT1 loss is associated with altered lipid levels in the central nervous system (CNS), including myelin-associated lipids within the corpus callosum (CC). Perturbed lipid metabolism was correlated with reduced numbers of OLs, but increased numbers of GFAP+ glia, in the CC, but not in grey matter. This was accompanied by reduced myelin protein expression and axonal conduction deficits. Behavioral analyses revealed significant changes in voluntary locomotor activity and anxiety-like behavior in RIT1KO mice. Together, these data reveal an unexpected role for RIT1 in the regulation of cerebral lipid metabolism, which coincide with altered white matter tract oligodendrocyte levels, reduced axonal conduction velocity, and behavioral abnormalities in the CNS.

Specific regulation of mechanical nociception by Gβ5 involves GABA-B receptors

Mechanical, thermal, and chemical pain sensation is conveyed by primary nociceptors, a subset of sensory afferent neurons. The intracellular regulation of the primary nociceptive signal is an area of active study. We report here the discovery of a Gβ5-dependent regulatory pathway within mechanical nociceptors that restrains anti-nociceptive input from metabotropic GABA-B receptors. In mice with conditional knockout (cKO) of Gnb5 targeted to peripheral sensory neurons, we demonstrate the impairment of mechanical, thermal, and chemical nociception. We further report the specific loss of mechanical nociception in Rgs7-Cre+/-; Gnb5fl/fl mice but not in Rgs9-Cre+/-; Gnb5fl/fl mice, suggesting that Gβ5 might specifically regulate mechanical pain in Rgs7+ cells. Additionally, Gβ5-dependent and Rgs7-associated mechanical nociception is dependent upon GABA-B receptor signaling since both were abolished by treatment with a GABA-B receptor antagonist and since cKO of Gβ5 from sensory cells or from Rgs7+ cells potentiated the analgesic effects of GABA-B agonists. Following activation by the Mrgprd agonist β-alanine, enhanced sensitivity to inhibition by baclofen was observed in primary cultures of Rgs7+ sensory neurons harvested from Rgs7-Cre+/-; Gnb5fl/fl mice. Taken together, these results suggest that the targeted inhibition of Gβ5 function in Rgs7+ sensory neurons might provide specific relief for mechanical allodynia, including that contributing to chronic neuropathic pain, without reliance on exogenous opioids.

Identification of plant beneficial Bacillus spp. for Resilient agricultural ecosystem

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The plant beneficial microbes from rhizosphere soils in cauliflower fields were characterized for plants beneficial attributes such as phosphorus solubilization, siderophore, chitinase and protease activity, and indole acetic acid type of growth regulator.

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The antagonistic behavior of these isolates against fusarium oxysporum and sclerotinia sclerotiorum revealed their potential in combating the biotic stresses.

The use of synthetic pesticides and chemicals to continuously increase agricultural productivity is causing severe damage to our ecosystem. Therefore, there is need to enhance our understanding about the factors which can contribute to soil processes and play key role in developing sustainable agricultural ecosystem. In this context, the bacteria from cauliflower rhizosphere were isolated and characterized for different plants beneficial attributes. The relationship of soil bacteria and its elemental composition was examined using canonical correspondence analysis. The elemental composition analysis of soil samples revealed presence of Mg, Al, Si, P, K, Ca, Fe and their oxides. In addition, the isolates were found positive for phosphorus solubilization, siderophore, chitinase and protease activity, and indole acetic acid type of growth regulator. The direct confrontation assay revealed antagonistic behavior of these isolates against Fusarium oxysporum and Sclerotinia sclerotiorum. The promising isolates were identified and affiliated to closely related species of genus Bacillus in phylogenetic relationship. The canonical correspondence analysis revealed distribution of elements and their relationship with the identified species in particular area. The characteristics of these isolates revealed their potential in alleviating the biotic and abiotic stresses and hence enhancing crops yield without the usage of synthetic fertilizers and pesticides. The present study is first of its kind and will open new avenues to explore microbial community structure across different farmlands soils to develop resilience agricultural ecosystem.

Easy and cost-efficient method for tumour localization in patients with breast cancer undergoing neoadjuvant chemotherapy followed by breast conservation therapy

This article describes placement of a radio-opaque clip for tumour localization to facilitate resection in patients undergoing neoadjuvant chemotherapy followed by breast conservation therapy. Use of a radio-opaque marker made of stainless steel K-wire and use of a Trucut® needle with a blunt stylet for wire placement in the breast tumour bed is a safe, indigenous, and cost-effective method for tumour localization.

Prevalence of TEM, SHV, and CTX-M Beta-Lactamase genes in the urinary isolates of a tertiary care hospital

Introduction:

Extended-spectrum beta-lactamases (ESBLs) are the major cause of resistance to beta-lactam antibiotics such as penicillins, cephalosporins, and monobactams. They are derived from the narrow-spectrum beta-lactamases (TEM-1, TEM-2, or SHV-1) by mutations that alter the amino acid configuration around the enzyme active site.

Aim:

To determine the prevalence of ESBL (bla_TEM, bla_CTX-M, and bla_SHV) genes among the members of Enterobacteriaceae.

Methodology:

The present prospective study was carried out from January 2015 to June 2015 in the Department of Microbiology and Molecular Medicine of a Teaching Tertiary Care Hospital. A total of 526 urine samples were studied. Seventy-eight isolates were subjected to polymerase chain reaction for detection of ESBL genes.

Results:

In our study, ESBL genes were detected among 18 (45%) phenotypically confirmed ESBL producers and 20 (52.5%) phenotypically confirmed non-ESBL producers. The gene that predominated was bla_TEM (48.7%), followed by bla_CTX-M (7.6%) and bla_SHV (5.1%).

Conclusion:

Definitive identification of ESBL genes is only possible by molecular detection methods. Phenotypic tests need to be evaluated periodically as their performance may change with the introduction of new enzymes.

Relationship of Imported Fire Ant (Hymenoptera: Formicidae) Integument Coloration to Cuticular Hydrocarbon and Venom Alkaloid Profiles

Red imported fire ant (Solenopsis invicta Buren; RIFA) and black imported fire ant (Solenopsis richteri Forel (Hymenoptera: Formicidae); BIFA) are considered distinct species with introgression via a reproductively functional hybrid (HIFA). The RIFA and BIFA common names are based on relative coloration. Due to human color perception variation, using color to identify RIFA, BIFA or HIFA is challenging. Fire ant identification traditionally involves molecular or chemical techniques, but a colorimetric test could allow rapid and low-cost identification. In this study, ant integument coloration was measured by spectrophotometer, and color attributes were compared to a combined gas chromatography (GC) index derived from cuticular hydrocarbon and venom alkaloid indices. Significant Pearson Correlation coefficients were found for colony GC index versus color attributes red to green (a*), blue to yellow (b*), chroma (C*), and hue (h*), but not lightness (L*). The RIFA colonies were distinct from BIFA for four of five color attributes and plots of the a*b* and C*h* horizontal axis of the L*a*b* and L*C*h* color spaces. Color attributes for HIFA indices were not distinct from BIFA and RIFA parental species, but HIFA a*b* and C*h* plots were distinct from RIFA and a*b* plots from BIFA. Color attributes a*, b*, and C* increased and h* decreased with GC index in a sinusoidal pattern. In conclusion, most RIFA and BIFA color attributes were distinct and a*b* and C*h* color axes plots had potential to distinguish HIFA from parental species, but coloration of HIFA indices was variable and complicated identifications among HIFA phenotypes, RIFA and BIFA.

Molecular and Genetic Characterization of Natural Variants of HIV-1 Nef Gene from North India and its Functional Implication in Down-Regulation of MHC-I and CD-4

BACKGROUND

HIV-1 Nef is an important accessory protein with multiple effector functions. Genetic studies of the HIV-1 Nef gene show extensive genetic diversity and the functional studies have been carried out mostly with Nef derived from regions dominated by subtype B (North America & Europe).

OBJECTIVE

This study was carried out to characterize genetic variations of the Nef gene from HIV-1 infected individuals from North India and to find out their functional implications.

METHODS

The unique representative variants were sub-cloned in a eukaryotic expression vector and further characterized with respect to their ability to downregulate cell surface expression of CD4 and MHC-1 molecules.

RESULTS

The phylogenetic analysis of Nef variants revealed sequence similarity with either consensus subtype B or B/C recombinants. Boot scan analysis of some of our variants showed homology to B/C recombinant and some to wild type Nef B. Extensive variations were observed in most of the variants. The dN/dS ratio revealed 80% purifying selection and 20% diversifying selection implying the importance of mutations in Nef variants. Intracellular stability of Nef variants differed greatly when compared with wild type Nef B and C. There were some variants that possessed mutations in the functional domains of Nef and responsible for its differential CD4 and MHC-1 downregulation activity.

CONCLUSION

We observed enhanced biological activities in some of the variants, perhaps arising from amino acid substitutions in their functional domains. The CD4 and MHC-1 down-regulation activity of Nef is likely to confer immense survival advantage allowing the most rare genotype in a population to become the most abundant after a single selection event.

Gqα/G11α deficiency in dorsomedial hypothalamus leads to obesity resulting from decreased energy expenditure and impaired sympathetic nerve activity

The G-protein subunits G_qα and G₁₁α (G_q/11α) couple receptors to phospholipase C, leading to increased intracellular calcium. In this study we investigated the consequences of G_q/₁₁α deficiency in the dorsomedial hypothalamus (DMH), a critical site for the control of energy homeostasis. Mice with DMH-specific deletion of G_q/11α (DMHGq/11KO) were generated by stereotaxic injection of adeno-associated virus (AAV)-Cre-green fluorescent protein (GFP) into the DMH of G_qα^flox/flox:G₁₁α^-/- mice. Compared with control mice that received DMH injection of AAV-GFP, DMHGq/11KO mice developed obesity associated with reduced energy expenditure without significant changes in food intake or physical activity. DMHGq/11KO mice showed no defects in the ability of the melanocortin agonist melanotan II to acutely stimulate energy expenditure or to inhibit food intake. At room temperature (22°C), DMHGq/11KO mice showed reduced sympathetic nervous system activity in brown adipose tissue (BAT) and heart, accompanied with decreased basal BAT uncoupling protein 1 (Ucp1) gene expression and lower heart rates. These mice were cold intolerant when acutely exposed to cold (6°C for 5 h) and had decreased cold-stimulated BAT Ucp1 gene expression. DMHGq/11KO mice also failed to adapt to gradually declining ambient temperatures and to develop adipocyte browning in inguinal white adipose tissue although their BAT Ucp1 was proportionally stimulated. Consistent with impaired cold-induced thermogenesis, the onset of obesity in DMHGq/11KO mice was significantly delayed when housed under thermoneutral conditions (30°C). Thus our results show that G_qα and G₁₁α in the DMH are required for the control of energy homeostasis by stimulating energy expenditure and thermoregulation.NEW & NOTEWORTHY This paper demonstrates that signaling within the dorsomedial hypothalamus via the G proteins G_qα and G₁₁α, which couple cell surface receptors to the stimulation of phospholipase C, is critical for regulation of energy expenditure, thermoregulation by brown adipose tissue and the induction of white adipose tissue browning.

Increased tracheostomy rates in head and neck cancer surgery during the COVID-19 pandemic

Surgical practice during the coronavirus disease 2019 (COVID-19) pandemic has changed significantly, without supporting data. With increasing experience, a dichotomy of practice is emerging, challenging existing consensus guidelines. One such practice is elective tracheostomy. Here, we share our initial experience of head and neck cancer surgery in a COVID-19 tertiary care centre, emphasizing the evolved protocol of perioperative care when compared to pre-COVID-19 times. This was a prospective study of 21 patients with head and neck cancers undergoing surgery during the COVID-19 pandemic, compared to 193 historical controls. Changes in anaesthesia, surgery, and operating room practices were evaluated. A strict protocol was followed. One patient tested positive for COVID-19 preoperatively. There was a significant increase in pre-induction tracheostomies (28.6% vs 6.7%, P = 0.005), median hospital stay (10 vs 7 days, P = 0.001), and postponements of surgery (57.1% vs 27.5%, P = 0.01), along with a significant decrease in flap reconstructions (33.3% vs 59.6%, P = 0.03). There was no mortality and no difference in postoperative morbidity. No healthcare personnel became symptomatic for COVID-19 during this period. Tracheostomy is safe during the COVID-19 pandemic and rates have increased. Despite increased rescheduling of surgeries and longer hospital stays, definitive cancer care surgery has not been deferred and maximum patient and healthcare worker safety has been ensured.

AB0713 PERIODONTAL DISEASES AND ITS ASSOCIATION WITH ANKYLOSING SPONDYLITIS/SPA: A SYSTEMATIC REVIEW

Background:

A close association between periodontal disease and Ankylosing spondylitis (AS) has long been specualted. Both diseases are characterized by dysregulation of the host inflammatory response, leading to further destruction of soft and hard connective tissue with there being evidence of increased levels of TNF-α and various interleukins in both patients of AS and periodontitis.

Objectives:

The aim of this systematic review was to appraise the available literature exploring the relationship between AS and periodontal disease.

Methods:

We searched Medline & Embase databases (from their inception till October 2019) using appropriate combinations of following search items with limits ‘(English, Human)’; Ankylosing spondylitis, spondyloarthritis, spondyloarthropathies, spondyloarthritides, spinal disease, musculoskeletal disease, Rheumatic disease AND periodontitis, periodontal disease, periodontoses, parodontoses, chronic periodontitis, gum disease, gingivitis, oral health, dental health, plaque index, bleeding on probing, probing pocket depth, clinical attachment loss. This search was supplemented by the manual search of bibliographies of articles selected and conferences proceedings of EULAR. Only be reviews, observational study of cross-sectional, cohort or case control type on adult patients with AS were selected. Data was extracted from a predesigned proforma. A close association between periodontal disease and Ankylosing spondylitis (AS) has long been specualted. Both diseases are characterized by dysregulation of the host inflammatory response, leading to further destruction of soft and hard connective tissue with there being evidence of increased levels of TNF-α and various interleukins in both patients of AS and periodontitis.

Results:

A total number of 984 articles were identified and 12 were selcted for detailed appraisal (Figure 1, PRISMA flow chart). They were all case control studies. The prevalence of periodontitis ranged from 38% to 88% in patients with AS whereas in the control group from 26% to 71 % in controls. Out of 12 studies, two showed significant changes in Plaque Index (PI), two studies showed altered Pocket Probing Depth (PPD), three showed significant increased in Clinical Attachment Loss (CAL) and increased Bleeding On Probing (BOP) was seen in 2 studies. In 7 studies, periodontitis was seen in a significant number of patients with AS (P<0.05). All studies reported that the prevalence of periodontal disease in AS patients was higher as compared to non-AS patients.

Conclusion:

Our systematic review found an association between AS and periodontal disease. Patients with AS show higher prevalence of periodontitis and a poor oral hygiene as compared to healthy controls. At practice level, this systematic review underscores the need for a collaboration between dentists and rheumatologist.

Disclosure of Interests:

None declared

Development of R7BP inhibitors through cross-linking coupled mass spectrometry and integrated modeling

Protein-protein interaction (PPI) networks are known to be valuable targets for therapeutic intervention; yet the development of PPI modulators as next-generation drugs to target specific vertices, edges, and hubs has been impeded by the lack of structural information of many of the proteins and complexes involved. Building on recent advancements in cross-linking mass spectrometry (XL-MS), we describe an effective approach to obtain relevant structural data on R7BP, a master regulator of itch sensation, and its interfaces with other proteins in its network. This approach integrates XL-MS with a variety of modeling techniques to successfully develop antibody inhibitors of the R7BP and RGS7/Gβ5 duplex interaction. Binding and inhibitory efficiency are studied by surface plasmon resonance spectroscopy and through an R7BP-derived dominant negative construct. This approach may have broader applications as a tool to facilitate the development of PPI modulators in the absence of crystal structures or when structural information is limited.

Worker Size, Geographical Distribution, and Introgressive Hybridization of Invasive Solenopsis invicta and Solenopsis richteri (Hymenoptera: Formicidae) in Tennessee

Worker size and geographical distribution of red imported fire ants (Solenopsis invicta Buren), black imported fire ants (Solenopsis richteri Forel), and their hybrid (S. invicta × S. richteri) (Hymenoptera: Formicidae) were evaluated from colonies sampled across Tennessee. The fire ant species and hybrid status were determined using cuticular hydrocarbon and venom alkaloid indices obtained from gas chromatography and mass spectrometry. Hybrids were the most common fire ant throughout Tennessee. With the exception of a few isolated S. invicta samples, only hybrids were found in east Tennessee, and hybrids predominated in middle Tennessee. In west Tennessee, mixed populations of S. richteri and hybrids were found. Hybrids were more common in west Tennessee than a survey performed a decade earlier. No statistical differences were detected in the average inter-colonial worker size of S. richteri and hybrids. Likewise, average worker size was not related to geographic location in Tennessee. The similarity in average worker size among hybrid colonies with a wide range of cuticular hydrocarbon and venom alkaloid values suggests introgression was not impacting ant size in colonies sampled throughout Tennessee.

Huntington's disease: the coming of age

Huntington's disease (HD) is caused due to an abnormal expansion of polyglutamine repeats in the first exon of huntingtin gene. The mutation in huntingtin causes abnormalities in the functioning of protein, leading to deleterious effects ultimately to the demise of specific neuronal cells.The disease is inherited in an autosomal dominant manner and leads to a plethora of neuropsychiatric behaviour and neuronal cell death mainly in striatal and cortical regions of the brain, eventually leading to death of the individual. The discovery of the mutant gene led to a surge in molecular diagnostics of the disease and in making different transgenic models in different organisms to understand the function of wild-type and mutant proteins. Despite difficult challenges, there has been a significant increase in understanding the functioning of the protein in normal and other gain-of-function interactions in mutant form. However, there have been no significant improvements in treatments of the patients suffering from this ailment and most of the treatment is still symptomatic. HD warrants more attention towards better understanding and treatment as more advancement in molecular diagnostics and therapeutic interventions are available. Several different transgenic models are available in different organisms, ranging from fruit flies to primate monkeys, for studies on understanding the pathogenicity of the mutant gene. It is the right time to assess the advancement in the field and try new strategies for neuroprotection using key pathways as target. The present review highlights the key ingredients of pathology in the HD and discusses important studies for drug trials and future goals for therapeutic interventions.

Salt responsive physiological, photosynthetic and biochemical attributes at early seedling stage for screening soybean genotypes

Salt stress affects all the stages of plant growth however seed germination and early seedling growth phases are more sensitive and can be used for screening of crop germplasm. In this study, we aimed to find the most effective indicators of salt tolerance for screening ten genotypes of soybean (SL-295, Gujosoya-2, PS-1042, PK-1029, ADT-1, RKS-18, KDS-344, MAUS-47, Bragg and PK-416). The principal component analysis (PCA) resulted in the formation of three different clusters, salt sensitive (SL-295, Gujosoya-2, PS-1042 and ADT-1), salt tolerant (MAUS-47, Bragg and PK-416) and moderately tolerant/sensitive (RKS-18, PK-1029 and KDS-344) suggesting that there was considerable genetic variability for salt tolerance in the soybean genotypes. Subsequently, genotypes contrasting in salt tolerance were analyzed for their physiological traits, photosynthetic efficiency and mitochondrial respiration at seedling and early germination stages under different salt (NaCl) treatments. It was found that salt mediated increase in AOX-respiration, root and shoot K+/Na+ ratio, improved leaf area and water use efficiency were the key determinants of salinity tolerance, which could modulate the net photosynthesis (carbon assimilation) and growth parameters (carbon allocation). The results suggest that these biomarkers could be can be useful for screening soybean genotypes for salt tolerance.

Optimization of genome editing through CRISPR-Cas9 engineering

CRISPR (Clustered Regularly-Interspaced Short Palindromic Repeats)-Cas9 (CRISPR associated protein 9) has rapidly become the most promising genome editing tool with great potential to revolutionize medicine. Through guidance of a 20 nucleotide RNA (gRNA), CRISPR-Cas9 finds and cuts target protospacer DNA precisely 3 base pairs upstream of a PAM (Protospacer Adjacent Motif). The broken DNA ends are repaired by either NHEJ (Non-Homologous End Joining) resulting in small indels, or by HDR (Homology Directed Repair) for precise gene or nucleotide replacement. Theoretically, CRISPR-Cas9 could be used to modify any genomic sequences, thereby providing a simple, easy, and cost effective means of genome wide gene editing. However, the off-target activity of CRISPR-Cas9 that cuts DNA sites with imperfect matches with gRNA have been of significant concern because clinical applications require 100% accuracy. Additionally, CRISPR-Cas9 has unpredictable efficiency among different DNA target sites and the PAM requirements greatly restrict its genome editing frequency. A large number of efforts have been made to address these impeding issues, but much more is needed to fully realize the medical potential of CRISPR-Cas9. In this article, we summarize the existing problems and current advances of the CRISPR-Cas9 technology and provide perspectives for the ultimate perfection of Cas9-mediated genome editing.

Macroscopic technique for the evaluation of oral tongue tumour thickness: a reliable intraoperative method

There is no reliable method to assess tumour thickness preoperatively or intraoperatively in cases of oral tongue squamous cell carcinoma (SCC). The purpose of this study was to evaluate the efficacy of a macroscopic technique to measure tumour thickness. This was a prospective study of 51 consecutive patients with T1/T2 primary SCC of the oral tongue. All patients underwent primary resection with ipsilateral neck dissection. Thickness measurements were obtained using Vernier calipers on the fresh specimen. The technique was correlated with the microscopic evaluation statistically using (1) Pearson's correlation coefficient, (2) intra-class correlation, and (3) Bland-Altman plot with 95% confidence intervals. On comparing the macroscopic technique to the microscopic evaluation, Pearson's correlation (r) was 0.915 (P<0.001). The inter-rater reliability using the intra-class correlation coefficient was 0.955. The Bland-Altman plot to test the agreement between the techniques showed the average difference between macroscopic thickness and microscopic thickness (bias) to be -0.421, with 95% limits of agreement of -3.166 and 2.82. There was a significant correlation and agreement between the macroscopic and microscopic measures of tumour thickness. The macroscopic technique could be used as a reliable tool to measure tumour thickness intraoperatively, prior to neck dissection.

Abstract P5-03-03: Designing a novel platinum chemotherapeutic (IO-125) for treatment of breast cancer

Triple-negative breast cancer (TNBC) is an aggressive form of cancer occurring in 15-20% of breast cancer patients, with most patients relapsing on currently approved therapy. Recent studies have shown activity of platinum chemotherapy in this class of patients. IO-125 is a novel platinum (II) chemotherapeutic agent with an unique coordination environment. In this study, we investigated the anti-tumor activity of IO-125 in pre-clinical models of TNBC.

The coordination environment in IO-125 facilitates supramolecular assembly and releases diaminocyclohexane (DACH)-platinum in a sustained pH-dependent manner. In vitro cell viability studies using an array of breast cancer cell lines shows IO-125 exerts increased potency compared to carboplatin or oxaliplatin. The maximum tolerated (platinum-equivalent) dose (MTD) of IO-125 in mice was 8-fold higher than the MTD (platinum-equivalent) dose of oxaliplatin. The biodistribution and pharmacokinetic profile of IO-125 in plasma and tumor revealed preferential tumor accumulation, significantly increased area-under-the-curve (AUC), a reduction in clearance (CL) and a longer terminal half-life (42 hours) in comparison to oxaliplatin (18 hours). In addition, DNA-Pt adduct formation in tumors was significantly higher for IO-125. When administered at their respective MTDs, IO-125 led to sustained regression of the tumor in a 4T1 syngeneic breast cancer model. Based on these observations, we conclude that IO-125 may emerge as a novel therapeutic against triple negative breast cancer.

Citation Format: Sengupta A, Roy M, Sarkar A, Mylavarapu S, Modi S, Gupta N, B H, Hossain S, Ansari A, Pandey M, Yadav Y, Sengupta S. Designing a novel platinum chemotherapeutic (IO-125) for treatment of breast cancer. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P5-03-03.

G(q/11)α and G(s)α mediate distinct physiological responses to central melanocortins

Activation of brain melanocortin 4 receptors (MC4Rs) leads to reduced food intake, increased energy expenditure, increased insulin sensitivity, and reduced linear growth. MC4R effects on energy expenditure and glucose metabolism are primarily mediated by the G protein G(s)α in brain regions outside of the paraventricular nucleus of the hypothalamus (PVN). However, the G protein(s) that is involved in MC4R-mediated suppression of food intake and linear growth, which are believed to be regulated primarily though action in the PVN, is unknown. Here, we show that PVN-specific loss of G(q)α and G11α, which stimulate PLC, leads to severe hyperphagic obesity, increased linear growth, and inactivation of the hypothalamic-pituitary-adrenal axis, without affecting energy expenditure or glucose metabolism. Moreover, we demonstrate that the ability of an MC4R agonist delivered to PVN to inhibit food intake is lost in mice lacking G(q/11)α in the PVN but not in animals deficient for G(s)α. The blood pressure response to the same MC4R agonist was only lost in animals lacking G(s)α specifically in the PVN. Together, our results exemplify how different physiological effects of GPCRs may be mediated by different G proteins and identify a pathway for appetite regulation that could be selectively targeted by G(q/11)α-biased MC4R agonists as a potential treatment for obesity.

Homology and enzymatic requirements of microhomology-dependent alternative end joining

Nonhomologous DNA end joining (NHEJ) is one of the major double-strand break (DSB) repair pathways in higher eukaryotes. Recently, it has been shown that alternative NHEJ (A-NHEJ) occurs in the absence of classical NHEJ and is implicated in chromosomal translocations leading to cancer. In the present study, we have developed a novel biochemical assay system utilizing DSBs flanked by varying lengths of microhomology to study microhomology-mediated alternative end joining (MMEJ). We show that MMEJ can operate in normal cells, when microhomology is present, irrespective of occurrence of robust classical NHEJ. Length of the microhomology determines the efficiency of MMEJ, 5 nt being obligatory. Using this biochemical approach, we show that products obtained are due to MMEJ, which is dependent on MRE11, NBS1, LIGASE III, XRCC1, FEN1 and PARP1. Thus, we define the enzymatic machinery and microhomology requirements of alternative NHEJ using a well-defined biochemical system.

SLC6A4 markers modulate platelet 5-HT level and specific behaviors of autism: a study from an Indian population

Presence of platelet hyperserotonemia and effective amelioration of behavioral dysfunctions by selective serotonin reuptake inhibitors (SSRI) in autism spectrum disorders (ASD) indicate that irregularities in serotonin (5-HT) reuptake and its homeostasis could be the basis of behavioral impairments in ASD patients. SLC6A4, the gene encoding serotonin transporter (SERT) is considered as a potential susceptibility gene for ASD, since it is a quantitative trait locus for blood 5-HT levels. Three functional polymorphisms, 5-HTTLPR, STin2 and 3'UTR-SNP of SLC6A4 are extensively studied for possible association with the disorder, with inconclusive outcome. In the present study, we investigated association of these polymorphisms with platelet 5-HT content and symptoms severity as revealed by childhood autism rating scale in ASD children from an Indian population. Higher 5-HT level observed in ASD was highly significant in children with heterozygous and homozygous genotypes comprising of minor alleles of the markers. Quantitative transmission disequilibrium test demonstrated significant genetic effect of STin2 allele as well as STin2/3'UTR-SNP and 5-HTTLPR/3'UTR-SNP haplotypes on 5-HT levels, but no direct association with overall CARS score and ASD phenotype. Significant genetic effect of the markers on specific behavioral phenotypes was observed for various sub-phenotypes of CARS in quantitative trait analysis. Even though the 5-HT level was not associated with severity of behavioral CARS score, a significant negative relationship was observed for 5-HT levels and level and consistency of intellectual response and general impression in ASD children. Population-based study revealed higher distribution of the haplotype 10/G of STin2/3'UTR-SNP in male controls, suggesting protective effect of this haplotype in male cases. Overall results of the study suggest that SLC6A4 markers have specific genetic effect on individual ASD behavioral attributes, might be through the modulation of 5-HT content.

Preinduction incentive spirometry versus deep breathing to improve apnea tolerance during induction of anesthesia in patients of abdominal sepsis: A randomized trial

BACKGROUND

Abdominal sepsis is associated with varied degree of hypoxemia and atelactasis in the lung and can enhance the onset of desaturation of arterial blood during apnea.

AIMS

This study looked at methods to improve safety margin of apnea during induction of anesthesia in these high-risk patients.

SETTINGS AND DESIGN

It was a randomized, single blind study on adult patients presenting for emergency laparotomy due to peritonitis in a university teaching hospital setting.

MATERIALS AND METHODS

In group 1 (IS) (n = 32), three sessions of incentive spirometry (IS) were performed within one hour before induction of anesthesia. In group 2 (DB) (n = 34), patients were subjected to deep breathing sessions in a similar manner. All patients received preoxygenation (100%) by mask for 3 min, followed by rapid-sequence induction of anesthesia using fentanyl, thiopental, and suxamethonium and endotracheal intubation. Patients were subjected to a period of apnea by keeping the end of the endotracheal tube open to air till they developed 95% hemoglobin saturation (SpO 2) by pulse oxymetry. Positive pressure ventilation was resumed at the end. We observed for hemodynamic changes, apnea time, and SpO 2 (100%) recovery time on resuming ventilation. Arterial blood gas samples were taken before intervention, after IS or DB, after preoxygenation, and at the end of apnea.

STATISTICAL ANALYSIS USED

One-way analysis of variance (ANOVA), X 2 test, Kaplan-Meier graph, and log-rank tests were applied to compare the two study groups.

RESULTS

Oxygenation level in group 1 (265 ± 76.7 mmHg) patients was significantly (P < 0.001) higher than in group 2 (221 ± 61.8 mmHg)at the end of preoxygenation. The apnea time (median: lower bound - upper bound Confidence Interval apnea time) (272:240-279 s) in group 1 (IS) patients was significantly higher P < 0.05) than in group 2 (180:163-209 s) patients. Saturation recovery time (35:34-46 s) in group 1 (IS) patients was also quicker than in group 2 patients (48:44-58 s).

CONCLUSIONS

IS in the preoperative period is superior to deep breathing sessions for improving apnea tolerance during induction of anesthesia in abdominal sepsis patients.

Improving the specificity and efficacy of CRISPR/CAS9 and gRNA through target specific DNA reporter

Genomic engineering by the guide RNA (gRNA)-directed CRISPR/CAS9 is rapidly becoming a method of choice for various biological systems. However, pressing concerns remain regarding its off-target activities and wide variations in efficacies. While next generation sequencing (NGS) has been primarily used to evaluate the efficacies and off-target activities of gRNAs, it only detects the imperfectly repaired double strand DNA breaks (DSB) by the error-prone non-homologous end joining (NHEJ) mechanism and may not faithfully represent the DSB activities because the efficiency of NHEJ-mediated repair varies depending on the local chromatin environment. Here we describe a reporter system for unbiased detection and comparison of DSB activities that promises to improve the chance of success in genomic engineering and to facilitate large-scale screening of CAS9 activities and gRNA libraries. Additionally, we demonstrated that the tolerances to mismatches between a gRNA and the corresponding target DNA can occur at any position of the gRNA, and depend on both specific gRNA sequences and CAS9 constructs used.

Biological behavior and disease pattern of carcinoma gallbladder shown on 64-slice CT scanner: a hospital-based retrospective observational study and our experience

PURPOSE

The aim of this diagnostic observational study was to assess the spread and biological behavior of gallbladder cancer using 64-slice computerized tomography (CT) scanner in this particular geographic belt (eastern Uttar Pradesh, western Bihar, and northern Madhya Pradesh provinces of North India). Indians are ethnically and culturally different from their Western counterparts among whom the incidence of this disease is comparatively low.

SUBJECTS AND METHODS

After systemic examination, all patients (87) were subjected to ultrasonographic examination. All cases were histopathologically proven. Confirmed cases were subjected to volumetric CT examination of abdomen and pelvis, plain, post contrast and delayed phase.

RESULTS

Majority of the cases were adenocarcinoma. There was female preponderance with majority belonging to fifth and sixth decades. Commonest presentation was diffuse, irregular, enhancing wall thickening in 49.4%. Majority had invasion of liver parenchyma (74.7%). Cholelithiasis was seen in 48.3% cases. Invasion of biliary radicals was high (13.8-18.4%). Eleven cases had invasion of portal vein and tumor thrombus, with hepatic artery invasion in one case. In two cases, both hepatic artery and portal vein invasion was seen. Portal and peripancreatic nodal metastasis was seen in 58.5%. Distant metastasis was reported.

CONCLUSION

Few studies involving the Indian population have attempted to use multi-row detector CT to define the biological behavior of carcinoma gallbladder. The opinion whether the pathology is operable or non-operable can reasonably be given. This large-scale, single-center study gives insight about the epidemiology and biological behavior of carcinoma gallbladder.

Estimation of factors from natural and anthropogenic radioactivity present in the surface soil and comparison with DCF values

A study was conducted to evaluate the absorbed rate coefficient of (238)U, (232)Th, (40)K and (137)Cs present in soil. A total of 31 soil samples and the corresponding terrestrial dose rates at 1 m from different locations were taken around the Anushaktinagar region, where the litho-logy is dominated by red soil. A linear regression model was developed for the estimation of these factors. The estimated coefficients (nGy h(-1) Bq(-1) kg(-1)) were 0.454, 0.586, 0.035 and 0.392, respectively. The factors calculated were in good agreement with the literature values.

Cerebellar abnormalities in mice lacking type 3 deiodinase and partial reversal of phenotype by deletion of thyroid hormone receptor α1

Thyroid hormone serves many functions throughout brain development, but the mechanisms that control the timing of its actions in specific brain regions are poorly understood. In the cerebellum, thyroid hormone controls formation of the transient external germinal layer, which contains proliferative granule cell precursors, subsequent granule cell migration, and cerebellar foliation. We report that the thyroid hormone-inactivating type 3 deiodinase (encoded by Dio3) is expressed in the mouse cerebellum at embryonic and neonatal stages, suggesting a need to protect cerebellar tissues from premature stimulation by thyroid hormone. Dio3(-/-) mice displayed reduced foliation, accelerated disappearance of the external germinal layer, and premature expansion of the molecular layer at juvenile ages. Furthermore, Dio3(-/-) mice exhibited locomotor behavioral abnormalities and impaired ability in descending a vertical pole. To ascertain that these phenotypes resulted from inappropriate exposure to thyroid hormone, thyroid hormone receptor α1 (TRα1) was removed from Dio3(-/-) mice, which substantially corrected the cerebellar and behavioral phenotypes. Deletion of TRα1 did not correct the previously reported small thyroid gland or deafness in Dio3(-/-) mice, indicating that Dio3 controls the activation of specific receptor isoforms in different tissues. These findings suggest that type 3 deiodinase constrains the timing of thyroid hormone action during cerebellar development.

The EIF4EBP3 translational repressor is a marker of CDC73 tumor suppressor haploinsufficiency in a parathyroid cancer syndrome

Germline mutation of the tumor suppressor gene CDC73 confers susceptibility to the hyperparathyroidism-jaw tumor syndrome associated with a high risk of parathyroid malignancy. Inactivating CDC73 mutations have also been implicated in sporadic parathyroid cancer, but are rare in sporadic benign parathyroid tumors. The molecular pathways that distinguish malignant from benign parathyroid transformation remain elusive. We previously showed that a hypomorphic allele of hyrax (hyx), the Drosophila homolog of CDC73, rescues the loss-of-ventral-eye phenotype of lobe, encoding the fly homolog of Akt1s1/ PRAS40. We report now an interaction between hyx and Tor, a central regulator of cell growth and autophagy, and show that eukaryotic translation initiation factor 4E-binding protein (EIF4EBP), a translational repressor and effector of mammalian target of rapamycin (mTOR), is a conserved target of hyx/CDC73. Flies heterozygous for Tor and hyx, but not Mnn1, the homolog of the multiple endocrine neoplasia type 1 (MEN1) tumor suppressor associated with benign parathyroid tumors, are starvation resistant with reduced basal levels of Thor/4E-BP. Human peripheral blood cell levels of EIF4EBP3 were reduced in patients with CDC73, but not MEN1, heterozygosity. Chromatin immunoprecipitation demonstrated occupancy of EIF4EBP3 by endogenous parafibromin. These results show that EIF4EBP3 is a peripheral marker of CDC73 function distinct from MEN1-regulated pathways, and suggest a model whereby starvation resistance and/or translational de-repression contributes to parathyroid malignant transformation.

Knockout of G protein β5 impairs brain development and causes multiple neurologic abnormalities in mice

Gβ5 is a divergent member of the signal-transducing G protein β subunit family encoded by GNB5 and expressed principally in brain and neuronal tissue. Among heterotrimeric Gβ isoforms, Gβ5 is unique in its ability to heterodimerize with members of the R7 subfamily of the regulator of G protein signaling proteins that contain G protein-γ like domains. Previous studies employing Gnb5 knockout (KO) mice have shown that Gβ5 is an essential stabilizer of such regulator of G protein signaling proteins and regulates the deactivation of retinal phototransduction and the proper functioning of retinal bipolar cells. However, little is known of the function of Gβ5 in the brain outside the visual system. We show here that mice lacking Gβ5 have a markedly abnormal neurologic phenotype that includes impaired development, tiptoe-walking, motor learning and coordination deficiencies, and hyperactivity. We further show that Gβ5-deficient mice have abnormalities of neuronal development in cerebellum and hippocampus. We find that the expression of both mRNA and protein from multiple neuronal genes is dysregulated in Gnb5 KO mice. Taken together with previous observations from Gnb5 KO mice, our findings suggest a model in which Gβ5 regulates dendritic arborization and/or synapse formation during development, in part by effects on gene expression.