Immunohistochemical Expression of Programmed Death Ligand- 1 (PD-L1) in Colorectal Carcinoma; A Cross-sectional Study.

Background & Objective: Colorectal carcinoma (CRC) is one of the most common cancers worldwide. The interaction of programmed cell death receptor 1 (PD-1) and programmed death ligand 1 (PD-L1) plays an important role by inhibiting the immune mechanism by which cancer cells escape antitumor immunity. Immunotherapy using checkpoint inhibitors is a growing treatment modality in many cancers; one such is anti-PD1/PD-L1. The present study aimed to study the immunohistochemical (IHC) expression of PD-L1 in CRC and its association with various known clinicopathological parameters. Methods: This study was a 2-year prospective study and included 34 colectomy specimens diagnosed as colorectal adenocarcinoma. The expression of PD-L1 was evaluated on tumoral cells and tumor-infiltrating immune cells (TIICs) and was correlated with various clinicopathological parameters. Results: Immunohistochemical expression of PD-L1 on tumoral cells and tumor microenvironment in CRC revealed positivity in 17.65% of cases each. The PD-L1 expression on tumoral cells was associated with lymphovascular invasion (LVI) and perineural invasion (PNI) with P- values of 0.012 and 0.005, respectively, while PD-L1 expression on TIICs was associated with tumor budding with a P-value of 0.022. Conclusion: IHC expression of PD-L1 on tumoral cells and immune cells may be associated with some known poor prognostic factors. Since anti-PD1/PD-L1 is used for targeted therapy, it may be beneficial and economically feasible to evaluate PD-L1 in CRC and establish its role as a prognostic factor.

Peripheral blood smear - An expeditious test in the preliminary diagnosis of bone marrow embolism in a case of multiple fractures: A case report.

ABSTRACT: Bone marrow embolism is known to occur after fractures of long bones such as the femur and pelvis. We report a case of multiple fractures in a 32-year-old female patient, demonstrating bone marrow elements in the peripheral blood as early as 2 hours after trauma. This is the first case being reported with an ante-mortem demonstration of circulating marrow emboli in the peripheral blood, while the previously reported cases have demonstrated the emboli in post-mortem examination. A careful correlation of the clinical history of trauma, hematology auto-analyzer results, and the presence of bone marrow particles and fat globules in peripheral blood helped in arriving at the diagnosis of fat embolism in our case irrefutably.

Association of Postoperative Hyperamylasemia With Clinically Relevant Postoperative Pancreatic Fistula in Pancreatoduodenectomy.

Background In this study, we aimed to determine the association between postoperative hyperamylasemia (POH) and clinically relevant postoperative pancreatic fistula (CR-POPF) after pancreatoduodenectomy (PD). Methodology A prospective observational study of 140 consecutive PDs between March 2020 and March 2022 was conducted. POH was defined as an elevation in serum pancreatic amylase levels above the institutional upper limit of normal on postoperative day (POD) 1 (>100 U/L). CR-POPF was defined as the International Study Group of Pancreatic Surgery Grade B or C POPF. The primary outcome was the rate of CR-POPF in the study population. The trial was prospectively registered with Clinicaltrials.gov (NCT04514198). Results In our study, 93 (66.42%) patients had POH (serum amylase >100 U/L). CR-POPF developed in 48 (34.28%) patients: 40 type B and 8 type C. CR-POPF rate was 43.01% (40/93) in patients with POH compared to 17.02% (8/47) in patients without POH (p = 0.0022). Patients with POH had a mean serum amylase of 422.7 ± 358.21 U/L on POD1 compared to 47.2 ± 20.19 U/L in those without POH (p < 0.001). Serum amylase >100 U/L on POD1 was strongly associated with developing CR-POPF (odds ratio = 3.71; 95% confidence interval = 1.31-10.37) on logistic regression, with a sensitivity and specificity of 83.3% and 42.4%, respectively. Blood loss >350 mL, pancreatic duct size <3 mm, and elevated POD1 serum amylase >100 U/L were predictive of CR-POPF on multivariate analysis (p < 0.001). Conclusions An elevated serum amylase on POD1 may help identify patients at risk for developing POPF following PD.

Understanding the Structural Arrangement of Islets in Chronic Pancreatitis.

Islet transplantation has become an established method for the treatment of insulin-deficient diabetes such as type 1 and type 3C (pancreatogenic). An effective transplantation necessitates a thorough understanding of the islet architecture and related functions to improve engraftment outcomes. However, in chronic pancreatitis (CP), the structural and related functional information is inadequate. Hence, the present study is aimed to understand the cytoarchitecture of endocrine cells and their functional implications in CP with and without diabetes. Herein, a set of human pancreatic tissue specimens (normal, n=5 and CP, n=20) was collected and processed for islet isolation. Furthermore, immunohistochemistry was used to assess the vascular densities, cell mass, organization, and cell-cell interactions. The glucose-stimulated insulin release results revealed that in chronic pancreatitis without diabetes mellitus altered (CPNDA), at basal glucose concentration the insulin secretion was increased by 24.2%, whereas at high glucose concentration the insulin levels were reduced by 77.4%. The impaired insulin secretion may be caused by alterations in the cellular architecture of islets during CP progression, particularly in chronic pancreatitis with diabetes mellitus and CPNDA conditions. Based on the results, a deeper comprehension of islet architecture would be needed to enhance successful transplantation in CP patients: (J Histochem Cytochem XX.XXX-XXX, XXXX).

Re-intervention rates and symptom-free survival at 1 year after endoscopic versus surgical management of strictures in Crohn's disease: A propensity matched analysis of a prospective inflammatory bowel disease cohort.

BACKGROUND AND AIM: Resection for Crohn's disease (CD) related strictures is definitive but carries risk of morbidity, recurrence, and short bowel syndrome. On the contrary, the durability of endotherapy (ET) for CD-related strictures is questionable. Prospective comparative studies are limited. We aimed to prospectively compare the outcomes of ET in CD strictures with a case-matched surgical therapy (ST) cohort. METHODS: Patients undergoing ET or resection for primary CD strictures (symptomatic, non-traversable, < 5 cm length, n ≤ 3) between January 2021 and March 2022 in a high-volume tertiary center were compared with regard to recurrent symptoms, escalation of therapy, re-intervention, and re-operation based on propensity matched analysis. RESULTS: Fifty-nine patients [49% ET, 57.6% male, median (years): 34 (15-74)] had ≥ 12 months of follow up. Before propensity matching, cumulative re-intervention rate was significantly higher with ET [34.5% (10/29) vs 3.3% (1/30) ST, P = 0.002]. Recurrent symptoms (34.5% vs 26.7%, P = 0.42), escalation of medical therapy (27.5% vs 23.3%, P = 0.64), and re-operation (7.4% vs 3.1%, P = 0.55) were comparable. In propensity matched analysis adjusted for demographics, disease, and stricture characteristics [n = 42, 21 each, 62% male, median (years): 32 (15-60)], cumulative probability of re-intervention rates was higher in ET (28.6% vs 4.8%, P = 0.042). The cumulative probability of recurrent symptoms (ET: 33.3% vs surgery 33.3%, P = 0.93), therapy escalation (ET: 23.8% vs surgery 28.6%, P = 0.75), and re-operation (ET: 9.5% vs surgery 4.8%, P = 0.57) was similar. CONCLUSIONS: ET for CD strictures require higher re-interventions compared with resection although re-operation could be avoided in the majority with comparable symptom free survival at 1 year.

Lesser prevalence of polyps/WNT-dysregulation and concomitant upregulation of gamma-catenin/MYC point to alternate pathways in colorectal cancer in India.

Colorectal cancer (CRC) is known to follow adenoma carcinoma sequence (ACS) in majority of the tumors and the driver variants and associated pathways are well delineated. However, most of the published data are from the west and information in other ethnicities is sparse. We therefore comprehensively evaluated the CRC tumors from Indian ethnicity for the prevalence of ACS. In this cohort study, clinical data of 100,497 patients who attended hospital between 2013 and 2018 were accessed. Tumors from patients (n = 130) with CRC who were treated primarily by surgery were included. DNA and RNA were isolated to assess variants (direct sequencing) and WNT-pathway dysregulation in genes related to ACS. Global gene expression was generated and analyzed on microarrays (Affymetrix; N = 10) and next generation sequencing platforms (Illumina; N = 25). Gene expression at mRNA (qRT-PCR) and protein level (IHC) of JUP/CTNNB1/MYC were assessed. Correlation between expression of JUP and MYC was evaluated by Karl Pearson's correlation coefficient. The prevalence of polyps was 16.75%, while 18.26% variants in APC/CTNNB1, 20.00% in KRAS, and 18.33% WNT dysregulation were noted. Interestingly, 29/60 (48.33%) tumors showed only MYC upregulation with normal APC/CTNNB1 expression. Global gene expression and validation in an independent tumor cohort confirmed concomitant upregulation of JUP (gamma-catenin) & MYC (r = 0.71; p = 0.001) at mRNA and protein in sizeable number of tumors (45/96; 46.88%). Our study provides evidence for limited prevalence of ACS in the Indian ethnicity. Preventive colonoscopies for early identification and management of CRC may not be an effective strategy in this ethnicity.

Imaging of a Pelvic Mass: Uterine.

The most common origin of a non-uterine pelvic mass is from the ovary. Ultrasound is the initial imaging modality of choice, additional imaging with computed tomography (CT) and/or magnetic resonance imaging (MRI) is performed in selected cases. Adnexal masses are also encountered as incidental findings during ultrasound, CT or MRI. Many of the adnexal masses that are surgically removed are benign. For optimal outcome and cost effective management, noninvasive risk stratification of such adnexal masses is necessary when discovered incidentally or when identified in a patient with a clinically detected pelvic mass. The American College of Radiology Ovarian-Adnexal Reporting Data System is a pattern-based scoring system for adnexal masses imaged with ultrasound and MRI, which assists clinicians to guide in the appropriate management based on evidence-based risk categories. Non-ovarian and non-uterine pelvic masses include fallopian tube abnormalities, paraovarian cysts, peritoneal inclusion cysts, and rare causes include masses that arise from the gastrointestinal tract or the sacrum. To distinguish non-ovarian masses from an ovarian tumor, a critical step is to identify a normal appearing ovary separate from the pelvic mass. This may be challenging in the post-menopausal woman with an atrophic ovary. MRI is a useful adjunctive modality in such cases. Extraovarian masses typically displace pelvic side wall vasculature medially, compress, encase or medially displace the ureters.

Acute Pelvic Pain: Role of Imaging in the Diagnosis and Management.

Acute pelvic pain is defined as a new symptom that has been present for less than 3 months. It is a common symptom seen in 15%-24% of women and is the indication for 20% of laparoscopies and 2%-10% of outpatient gynecologic visits. The pregnancy status and correlation of the physical symptoms with clinical findings are important. Ultrasound is the imaging modality of choice, not only to diagnose gynecological causes, but also bowel or urinary tract related causes of pelvic pain. When an ultrasound scan is inconclusive, a computed tomography scan is the preferred means of additional imaging and is particularly useful in gastrointestinal and urogenital causes of pelvic pain. Gynecological causes of acute pelvic pain include uterine, tubal, or ovarian pathology; non-gynecological causes include bowel diseases, such as appendicitis and diverticulitis; urogenital causes such as ureteral, bladder stones, and urinary tract infection as well as vascular causes. Ultrasound imaging alone may provide a definitive diagnosis in underlying conditions that require prompt medical or surgical intervention in gynecological conditions, such as ovarian torsion, ectopic pregnancy, and non-gynecological condition, such as in acute appendicitis.

Post-Menopausal Bleeding: Role of Imaging.

Post-menopausal bleeding (PMB) accounts for 5% of gynecologic office visits and is the presenting symptom in 90% of women with endometrial cancer, which requires prompt evaluation. The most common etiology of PMB is vaginal or endometrial atrophy and endometrial polyps, while endometrial hyperplasia and carcinoma account for less than 10% of PMB. Transvaginal ultrasonography measurement of an endometrial thickness (EMT) less than or equal to 4 mm has a 99% negative predictive value for endometrial carcinoma. Endometrial sampling is required if EMT >4 mm or persistent bleeding occurs. Further evaluation can be accomplished with saline infusion sonography, magnetic resonance imaging, and hysteroscopy.

Abnormal Uterine Bleeding in Reproductive Age Women: Role of Imaging in the Diagnosis and Management.

Abnormal uterine bleeding (AUB) is defined by the International Federation of Gynecology and Obstetrics as bleeding from the uterine corpus that is abnormal in regularity, volume, frequency, or duration and occurs in the absence of pregnancy. AUB is a common condition that affects about a third of women in their lifetime. Abnormal bleeding in duration, quantity, or timing consists of 2 categories, predictable cyclical heavy menstrual bleeding (HMB) and irregular non-cyclical intermenstrual bleeding (IMB). The most common causes of HMB include fibroids and adenomyosis and IMB is commonly caused by ovulatory dysfunction such as in polycystic ovaries, endometrial polyp, or an IUD. A pelvic ultrasound is the initial and often only imaging modality needed in the imaging evaluation of abnormal uterine bleeding and can accurately identify the common causes of abnormal uterine bleeding in the reproductive age group.

Wide field block face imaging using deep ultraviolet induced autofluorescence of the human brain.

BACKGROUND: Imaging large volume human brains at cellular resolution involve histological methods that cause structural changes. A reference point prior to sectioning is needed to quantify these changes and is achieved by serial block face imaging (BFI) methods that have been applied to small volume tissue (∼1 cm3). NEW METHOD: We have developed a BFI uniquely designed for large volume tissues (∼1300 cm3) with a very large field of view (20 × 20 cm) at a resolution of 70 µm/pixel under deep ultraviolet (UV-C) illumination which highlights key features. RESULTS: The UV-C imaging ensures high contrast imaging of the brain tissue and highlights salient features of the brain. The system is designed to provide uniform and stable illumination across the entire surface area of the tissue and to work at low temperatures, which are required during cryosectioning. Most importantly, it has been designed to maintain its optical focus over the large depth of tissue and over long periods of time, without readjustments. The BFI was installed within a cryomacrotome, and was used to image a large cryoblock of an adult human cerebellum and brainstem (∼6 cm depth resulting in 2995 serial images) with precise optical focus and no loss during continuous serial acquisition. COMPARISON WITH EXISTING METHOD(S): The deep UV-C induced BFI highlights several large fibre tracts within the brain including the cerebellar peduncles, and the corticospinal tract providing important advantage over white light BFI. CONCLUSIONS: The 3D reconstructed serial BFI images can assist in the registration and alignment of the microscopic high-resolution histological tissue sections.

Chemogenetic Enhancement of cAMP Signaling Renders Hippocampal Synaptic Plasticity Resilient to the Impact of Acute Sleep Deprivation.

Sleep facilitates memory storage and even brief periods of sleep loss lead to impairments in memory, particularly memories that are hippocampus dependent. In previous studies, we have shown that the deficit in memory seen after sleep loss is accompanied by deficits in synaptic plasticity. Our previous work has also found that sleep deprivation (SD) is associated with reduced levels of cyclic adenosine monophosphate (cAMP) in the hippocampus and that the reduction of cAMP mediates the diminished memory observed in sleep-deprived animals. Based on these findings, we hypothesized that cAMP acts as a mediator for not only the cognitive deficits caused by sleep deprivation, but also the observed deficits in synaptic plasticity. In this study, we expressed the heterologous Drosophila melanogaster Gαs-protein-coupled octopamine receptor (DmOctß1R) in mouse hippocampal neurons. This receptor is selectively activated by the systemically injected ligand (octopamine), thus allowing us to increase cAMP levels in hippocampal neurons during a 5-h sleep deprivation period. Our results show that chemogenetic enhancement of cAMP during the period of sleep deprivation prevents deficits in a persistent form of long-term potentiation (LTP) that is induced at the Schaffer collateral synapses in the hippocampal CA1 region. We also found that elevating cAMP levels in either the first or second half of sleep deprivation successfully prevented LTP deficits. These findings reveal that cAMP-dependent signaling pathways are key mediators of sleep deprivation at the synaptic level. Targeting these pathways could be useful in designing strategies to prevent the impact of sleep loss.

Glucose derived carbon nanosphere (CSP) conjugated TTK21, an activator of the histone acetyltransferases CBP/p300, ameliorates amyloid-beta 1-42 induced deficits in plasticity and associativity in hippocampal CA1 pyramidal neurons.

The master epigenetic regulator lysine acetyltransferase (KAT) p300/CBP plays a pivotal role in neuroplasticity and cognitive functions. Recent evidence has shown that in several neurodegenerative diseases, including Alzheimer's disease (AD), the expression level and function of p300/CBP are severely compromised, leading to altered gene expression causing pathological conditions. Here, we show that p300/CBP activation by a small-molecule TTK21, conjugated to carbon nanosphere (CSP) ameliorates Aß-impaired long-term potentiation (LTP) induced by high-frequency stimulation, theta burst stimulation, and synaptic tagging/capture (STC). This functional rescue was correlated with CSP-TTK21-induced changes in transcription and translation. Mechanistically, we observed that the expression of a large number of synaptic plasticity- and memory-related genes was rescued, presumably by the restoration of p300/CBP mediated acetylation. Collectively, these results suggest that small-molecule activators of p300/CBP could be a potential therapeutic molecule for neurodegenerative diseases like AD.

Endoplasmic reticulum chaperone genes encode effectors of long-term memory.

The mechanisms underlying memory loss associated with Alzheimer's disease and related dementias (ADRD) remain unclear, and no effective treatments exist. Fundamental studies have shown that a set of transcriptional regulatory proteins of the nuclear receptor 4a (Nr4a) family serve as molecular switches for long-term memory. Here, we show that Nr4a proteins regulate the transcription of genes encoding chaperones that localize to the endoplasmic reticulum (ER). These chaperones fold and traffic plasticity-related proteins to the cell surface during long-lasting forms of synaptic plasticity and memory. Dysregulation of Nr4a transcription factors and ER chaperones is linked to ADRD, and overexpressing Nr4a1 or the chaperone Hspa5 ameliorates long-term memory deficits in a tau-based mouse model of ADRD, pointing toward innovative therapeutic approaches for treating memory loss. Our findings establish a unique molecular concept underlying long-term memory and provide insights into the mechanistic basis of cognitive deficits in dementia.

Mice Lacking the cAMP Effector Protein POPDC1 Show Enhanced Hippocampal Synaptic Plasticity.

Extensive research has uncovered diverse forms of synaptic plasticity and an array of molecular signaling mechanisms that act as positive or negative regulators. Specifically, cyclic 3',5'-cyclic adenosine monophosphate (cAMP)-dependent signaling pathways are crucially implicated in long-lasting synaptic plasticity. In this study, we examine the role of Popeye domain-containing protein 1 (POPDC1) (or blood vessel epicardial substance (BVES)), a cAMP effector protein, in modulating hippocampal synaptic plasticity. Unlike other cAMP effectors, such as protein kinase A (PKA) and exchange factor directly activated by cAMP, POPDC1 is membrane-bound and the sequence of the cAMP-binding cassette differs from canonical cAMP-binding domains, suggesting that POPDC1 may have an unique role in cAMP-mediated signaling. Our results show that Popdc1 is widely expressed in various brain regions including the hippocampus. Acute hippocampal slices from Popdc1 knockout (KO) mice exhibit PKA-dependent enhancement in CA1 long-term potentiation (LTP) in response to weaker stimulation paradigms, which in slices from wild-type mice induce only transient LTP. Loss of POPDC1, while not affecting basal transmission or input-specificity of LTP, results in altered response during high-frequency stimulation. Popdc1 KO mice also show enhanced forskolin-induced potentiation. Overall, these findings reveal POPDC1 as a novel negative regulator of hippocampal synaptic plasticity and, together with recent evidence for its interaction with phosphodiesterases (PDEs), suggest that POPDC1 is involved in modulating activity-dependent local cAMP-PKA-PDE signaling.

Is intraoperative enteroscopy still relevant in small bowel disorders in the era of capsule endoscopy and device-assisted enteroscopy? Real-world experience from a tertiary care hospital.

BACKGROUND AND AIM: With the advent of video capsule endoscopy (VCE) and device-assisted enteroscopy (DAE), the indication of intraoperative enteroscopy (IOE) has become limited due to reported high morbidity/mortality. Most of the earlier studies on IOE were small/from pre-VCE/DAE era. We aimed to evaluate the impact of IOE in management of small bowel disorders (SBD) in post-VCE/DAE era. METHODS: Patients with SBD undergoing IOE over last 15 years were evaluated retrospectively. Overall diagnostic/therapeutic yield, incremental diagnostic yield over preoperative investigations, and adverse events were noted. We also evaluated the number of cases in which IOE changed the management or guided surgical or endoscopic therapy. Rebleeding and recurrence were evaluated in patients with available follow-up data. RESULTS: A total of 89 patients (59 male, 9-82 years) were included in the study. Overall diagnostic and therapeutic yield were 92.1% and 85.4%, respectively. Common findings of IOE were benign ulcers/strictures (30.1%), vascular lesions (26%), diverticula (15.1%), and tumors (13.7%). A total of 49.4% (44/89), 36% (32/89), and 20.2% (18/89) underwent VCE, DAE, or both, respectively, before IOE. Incremental diagnostic yield over preoperative work-up was 31.5% (28/89), and IOE changed the management in 37.1% (33/89) patients. IOE was used to guide surgery/endotherapy in 39.3% (35/89) patients. Recurrent gastrointestinal bleed occurred in 21.2% (14/66) patients. Morbidity and mortality rates were 20.2% (18/89) and 3.4% (3/89), respectively. CONCLUSIONS: Intraoperative enteroscopy remains an essential technique to evaluate SBD and can detect new and additional lesions even after extensive preoperative evaluation. IOE is useful in guiding therapy in preoperatively identified lesions and can change management in a substantial proportion of patients. Hence, IOE has a definitive role in post-VCE/DAE era in carefully selected patients with SBD.

Selective role of the translin/trax RNase complex in hippocampal synaptic plasticity.

Activity-dependent local protein synthesis is critical for synapse-specific, persistent plasticity. Abnormalities in local protein synthesis have been implicated in psychiatric disorders. We have recently identified the translin/trax microRNA-degrading enzyme as a novel mediator of protein synthesis at activated synapses. Additionally, translin knockout (KO) mice, which lack translin/trax, exhibit some of the behavioral abnormalities found in a mouse model of fragile X syndrome (fragile X mental retardation protein-FMRP-KO mice). Therefore, identifying signaling pathways interacting with translin/trax to support persistent synaptic plasticity is a translationally relevant goal. Here, as a first step to achieve this goal, we have assessed the requirement of translin/trax for multiple hippocampal synaptic plasticity paradigms that rely on distinct molecular mechanisms. We found that mice lacking translin/trax exhibited selective impairment in a form of persistent hippocampal plasticity, which requires postsynaptic protein kinase A (PKA) activity. In contrast, enduring forms of plasticity that are dependent on presynaptic PKA were unaffected. Furthermore, these mice did not display exaggerated metabotropic glutamate receptor-mediated long-term synaptic depression (mGluR-LTD), a hallmark of the FMRP KO mice. On the contrary, translin KO mice exhibited deficits in N-methyl-D-aspartate receptor (NMDAR) dependent LTD, a phenotype not observed in the FMRP knockouts. Taken together, these findings demonstrate that translin/trax mediates long-term synaptic plasticity that is dependent on postsynaptic PKA signaling and suggest that translin/trax and FMRP play distinct roles in hippocampal synaptic plasticity.