P21-activated kinase 1 (Pak1) signaling influences therapeutic outcome in pancreatic cancer.

BACKGROUND: Therapeutic resistance to gemcitabine in pancreatic ductal adenocarcinoma (PDAC) is attributed to various cellular mechanisms and signaling molecules that influence as a single factor or in combination. DESIGN: In this study, utilizing in vitro p21-activated kinase 1 (Pak1) overexpression and knockdown cell line models along with in vivo athymic mouse tumor xenograft models and clinical samples, we demonstrate that Pak1 is a crucial signaling kinase in gemcitabine resistance. RESULTS: Pak1 kindles resistance via modulation of epithelial-mesenchymal transition and activation of pancreatic stellate cells. Our results from gemcitabine-resistant and -sensitive cell line models showed that elevated Pak1 kinase activity is required to confer gemcitabine resistance. This was substantiated by elevated levels of phosphorylated Pak1 and ribonucleotide reductase M1 levels in the majority of human PDAC tumors when compared with normal. Delineation of the signaling pathway revealed that Pak1 confers resistance to gemcitabine by preventing DNA damage, inhibiting apoptosis and regulating survival signals via NF-κB. Furthermore, we found that Pak1 is an upstream interacting substrate of transforming growth factor ß-activated kinase 1-a molecule implicated in gemcitabine resistance. Molecular mechanistic studies revealed that gemcitabine docks with the active site of Pak1; furthermore, gemcitabine treatment induces Pak1 kinase activity both in vivo and in cell-free system. Finally, results from athymic mouse tumor models illustrated that Pak1 inhibition by IPA-3 enhances the cytotoxicity of gemcitabine and brings about pancreatic tumor regression. CONCLUSION: To our knowledge, this is the first study illustrating the mechanistic role of Pak1 in causing gemcitabine resistance via multiple signaling crosstalks, and hence Pak1-specific inhibitors will prove to be a better adjuvant with existing chemotherapy modality for PDAC.

Role of multidetector abdominal CT in the evaluation of abnormalities in polyarteritis nodosa.

AIM: To identify arterial and end-organ abnormalities on abdominal computed tomography (CT) in patients with polyarteritis nodosa (PAN). MATERIALS AND METHODS: A prospective study comprising 27 consecutive patients with PAN was conducted from 2007 to 2013. Departmental ethics committee approval was obtained. All patients underwent contrast-enhanced CT comprising an arterial and a portal venous phase. Images were assessed for arterial irregularity, aneurysms, stenosis, and occlusion. End-organ changes, including infarcts, haematoma, and bowel involvement, were also recorded. RESULTS: A positive CT was recorded in 15 patients including eight females. The mean age was 32 years. The most common abnormalities were aneurysms seen in 12 patients. The renal artery was the most common site of aneurysms (n=9). The hepatic (n=3), superior mesenteric (n=3) and splenic arteries (n=1) were also involved. Contour irregularity was noted in four patients involving the hepatic, splenic, and superior mesenteric arteries. Stenosis/occlusion was also noted in seven patients. The most common end-organ abnormality was infarct (n=9), followed by bowel wall thickening (n=3), and perinephric haematoma (n=2). CONCLUSION: A combination of arterial and end-organ abnormalities on abdominal CT enables an accurate diagnosis of PAN in occult cases and may obviate the need for angiography and, sometimes, biopsy.

Comparison of outcomes of infants with giant omphaloceles over two decades.

BACKGROUND: The purpose of this study was to compare the outcomes of infants with giant omphalocele (GO) born in two different epochs over two decades at a single institution. Specifically, it examined whether the utilization of selective pulmonary vasodilators and extracorporeal membrane oxygenator (ECMO) in the management of pulmonary hypertension in the second epoch were associated with improved outcomes. METHODS: The medical records of all patients diagnosed with GO at a large children's hospital from January 1, 1996 to December 31, 2016 were reviewed and divided into two epochs. Patients were classified as having an isolated GO or GO with minor or major associated anomalies. GO was defined as a defect more than or equal to 5 cm in size and/or liver in the sac. RESULTS: During the study period, 59 infants with GO were identified. The duration of invasive mechanical ventilation was significantly shorter among the survivors from the second epoch (p = 0.03), with none greater than seven days. There were no significant differences in the outcomes of survival to NICU discharge and length of stay (LOS) between infants in the two epochs. CONCLUSIONS: Infants with GO who required invasive mechanical ventilation for more than seven days did not survive in the second epoch. Survival did not improve with use of selective pulmonary vasodilators and ECMO. This information could be shared with families during prenatal and postnatal counselling to facilitate informed decision making regarding goals of care.

Genetic analysis of precore/core and partial pol genes in an unprecedented outbreak of fulminant hepatitis B in India.

We investigated an unprecedented outbreak of fulminant hepatitis B virus (HBV) that occurred in Modasa, Gujarat (India) in 2009. Genomic analysis of all fulminant hepatic failure cases confirmed exclusive predominance of subgenotype D1. A1762T, G1764A basal core promoter (BCP) mutations, insertion of isoleucine after nt 1843, stop codon mutation G1896A, G1862T transversion plus seven other mutations in the core gene caused inhibition of HBeAg expression implicating them as circulating precore/BCP mutant virus. Two rare mutations at amino acids 89 (Ile→Ala) and 119 (Leu→Ser) in addition to other mutations in the polymerase (pol) gene may have caused some alteration in either of four pol gene domains to affect encapsidation of pregenomic RNA to enhance pathogenicity. Sequence similarity among patients' sequences suggested an involvement of a single hepatitis B mutant strain/source to corroborate the finding of gross and continued usage of HBV mutant-contaminated syringes/needles by a physician which resulted in this unprecedented outbreak of fulminant hepatitis B. The fulminant exacerbation of the disease might be attributed to mutations in the BCP/precore/core and pol genes that may have occurred due to selection pressure during rapid spread/mutation of the virus.

Haemorrhage control beyond Advanced Trauma Life Support (ATLS) protocol in life threatening maxillofacial trauma - experience from a level â trauma centre.

Maxillofacial injuries are usually not life-threatening and do not get priority over other associated injuries. However, some maxillofacial injuries with active oral or nasal bleeding need immediate management due to threatened airway and blood loss. In the case of major active vascular bleeding, measures such as local pressure, anterior nasal packing, posterior nasal packing, and balloon tamponade are ineffective. In these cases, angiography and transcatheter arterial embolisation (TAE) are used to treat life-threatening haemorrhage caused by maxillofacial trauma. We analysed the medical records of 39 patients with severe maxillofacial trauma and life-threatening haemorrhage that was a result of intractable oral or nasal bleeding. These patients were considered for TAE from January 2010 to December 2019. A total of 1668 patients was admitted, out of which 39 (2.3%) had severe maxillofacial injuries with life-threatening oral or nasal bleeding and underwent TAE. Out of a total of 39 patients, 38 were male and one female. Ages ranged from 16 to 65 years. Road traffic injury was the most common cause of injury (79.5%), Lefort I and II were the most common facial fractures, and traumatic brain injury was the most common associated injury. Embolisation and bleeding control were done successfully in all 39 patients with no procedure-related complications. A total of 17 deaths during the study period were due to severe traumatic brain injuries or haemorrhagic shock.

A rare case of life-threatening penetrating oropharyngeal trauma caused by toothbrush in a child.

We present a case of 10 year-old boy with oropharyngeal injury caused by a toothbrush which penetrated the parapharyngeal space. Initial examination revealed broken end of the toothbrush in oral cavity with the head of the toothbrush having bristles, beyond the soft palate. Tongue and palate were lacerated and there were blood and oral secretions in the oral cavity. Patient was having bradycardia. Computed tomography (CT) scan showed the toothbrush head near the carotid artery, the carotid being laterally displaced. The foreign body was surgically removed without any intraoperative or postoperative complications.

Modified functionally generated path technique to develop occlusal scheme in single complete denture.

Single maxillary denture often represents vigorous challenge to the practicing dentists. The difficulty arises when the maxillary dentures are set to fit the occlusion of natural mandibular teeth. The functionally generated pathway technique registers occlusal pathways of the posterior teeth in functional wax and is described as the "three-dimensional static expression consists of dynamic tooth movement." The current article represents a technique for a patient who was rehabilitated with a maxillary complete denture, and a harmonious occlusion was achieved between the complete denture and the mandibular natural dentition. Functional maxillary denture is therefore in medical dentistry the successful culmination of human's high practice and represents the golden goal sought by every dental practitioner and expected by every denture patient.

Pilot feasibility study to detect mesenchymal stem cell biomarkers of bronchopulmonary dysplasia in the tracheal aspirate fluid of preterm infants.

OBJECTIVE: This study aimed to detect novel mesenchymal stem cell peptides/biomarkers of bronchopulmonary dysplasia (BPD) in the tracheal aspirate fluid (TAF) of preterm infants. STUDY DESIGN: Participants included infants less than 32 weeks' gestational age or birth weight under 1500 grams who required endotracheal intubation and mechanical ventilation within first 24 hours of life. TAF sample collection was performed at the time of the first clinically indicated routine suctioning. Standardization curves for human levels of osteopontin (Opn), macrophage colony stimulating factor 1 (Csf1), transforming growth factor beta 1 (TGF-ß1), and secretory immunoglobulin A (sIgA) were generated for 15 enrolled participants. RESULTS: We demonstrated that stem cell biomarkers are secreted into the TAF of preterm infants and their concentrations can be easily measured during the first week of life. CONCLUSIONS: Further studies are warranted to determine a causal relationship between these biomarkers and BPD development and severity.

Practical consensus recommendations regarding the management of HER2 neu positive metastatic breast cancer.

Metastatic breast cancer (MBC) is cancer that has spread from the breast to another part of the body or has come back in another distant location. Treatment options for MBC depend on several factors, including where the cancer has spread, the patient's overall health, and the levels of hormone receptors and HER2 in the tumour. Over-expression of HER2 is generally considered to be a negative prognostic feature because it accompanies an increase in breast cancer mortality. However, the development of agents that specifically target HER2 has improved the management of patients with these tumours.[7],[8],[9],[10] This expert group used data from published literature, practical experience and opinion of a large group of academic oncologists to arrive at these practical consensus recommendations in regards with the use of these agents and the management of HER2 positive MBC for the benefit of community oncologists.

Practical consensus recommendations on ovarian suppression in early breast cancer (adjuvant).

Substantial survival benefits exist for patients with early-stage breast cancer who undergo treatment with single-modality ovarian suppression, but its value is uncertain. Expert oncologist discussed to determine whether additional benefits exist with ovarian suppression plus multiple adjuvant therapy which provides a new treatment option that reduces the risk of recurrence in early breast cancer. This expert group used data from published literature, practical experience and opinion of a large group of academic oncologists to arrive at this practical consensus recommendations for the benefit of community oncologists.

Neutropenic enterocolitis.

We report a case of neutropenic enterocolitis diagnosed on computerized tomography abdomen in a 56-year-old man having high-grade non-Hodgkin's lymphoma. After appropriate management, the patient recovered completely.

Risk factor profiling and study of atherosclerotic coronary plaque burden and morphology with coronary computed tomography angiography in coronary artery disease among young Indians.

BACKGROUND: With a decade earlier manifestation of coronary artery disease (CAD) and paucity of data characterizing coronary plaque with coronary computed tomography angiography (CTA) among CAD patients in India, the study aimed to analyze patient characteristics and coronary plaque burden and morphology in young Indian patients with CAD. METHODS: Serial coronary CTA was performed in 96 CAD patients. Among 60 patients ≤40years, risk factor and coronary plaque analysis done using a 256- slice CT in 33 patients with acute coronary syndrome (ACS) was compared with 27 patients with chronic stable angina (CSA). Univariate and multivariate analysis was performed, for factors predicting ACS as an outcome among young CAD patients. In addition, quantitative and morphologic plaque characteristics were compared among those ≤40years and >40years. RESULTS: Among 60 subjects ≤40years of age, 77% had dyslipidemia, 70% high lipoprotein(a), 53.33% elevated hs-CRP and 73.33% raised homocysteine. hs-CRP (9.33 vs. 3.33, p value=0.01) and serum triglycerides (178.67 vs. 141.42, p value=0.03) were markedly raised in patients with ACS. Statistically significant number of patients in the ACS group had positive remodelling (ACS, 69.7% vs. CSA, 14.8%; p value<0.001), low attenuation plaque (ACS, 63.6% vs. CSA, 11.1%; p value<0.001), spotty calcification (ACS, 36.4% vs. CSA, 3.7%; p=0.002) and non-calcified plaque (ACS, 69.7% vs. CSA, 11.1%; p<0.001). On multivariate analysis, only lipoprotein (a) >30mg/dL and composite vulnerability score maintained a predictive value for ACS in patients ≤40years. Statistically significant number of patients in the younger age group had higher mean total plaque volume (66.17±41.31mm3 vs. 44.94±49.07mm3; p=0.03), remodelling index (1.5±0.27 vs. 1.08±0.38; p=0.0001). Comparing culprit lesion characteristics of ACS patients in the two age groups, positive remodelling (95.8% vs. 70.5%, p=0.02), spotty calcification (50% vs. 11.7%, p=0.01) and non-calcified plaque (95.8% vs. 70.5%, p=0.02) were significantly more frequent in patients ≤40years. CONCLUSION: ACS in young Indians is characterized by a higher prevalence of both conventional and newer risk factors. In addition, culprit lesions in young ACS patients are more frequently characterized by coronary plaques with high risk morphological features. This may have implications in terms of preventive strategies to identify this high-risk group.

OSCE as a Summative Assessment Tool for Undergraduate Students of Surgery-Our Experience.

Traditional examination has inherent deficiencies. Objective Structured Clinical Examination (OSCE) is considered as a method of assessment that may overcome many such deficits. OSCE is being increasingly used worldwide in various medical specialities for formative and summative assessment. Although it is being used in various disciplines in our country as well, its use in the stream of general surgery is scarce. We report our experience of assessment of undergraduate students appearing in their pre-professional examination in the subject of general surgery by conducting OSCE. In our experience, OSCE was considered a better assessment tool as compared to the traditional method of examination by both faculty and students and is acceptable to students and faculty alike. Conducting OSCE is feasible for assessment of students of general surgery.

Presence of fucolipid antigens with mono- and dimeric X determinant (Lex) in the circulating immune complexes of patients with adenocarcinoma.

A series of fucosylated glycosphingolipids with the Lewisx (Lex) determinant (Gal beta 1----4[Fuc alpha 1----3]GlcNAc) have been shown to accumulate in human adenocarcinomas. Lex glycolipids were eluted from Protein A-silica columns over which plasma from patients with adenocarcinoma had previously been perfused. The fact that Protein A has strong affinity for IgG and IgG-immune complexes suggested that the Lex antigens isolated from Protein A eluates were complexed with IgG. Lewisx antigen eluted from Protein A columns banded in the immune complex-enriched region (below IgG) of neutral sucrose density gradients. A modified Raji cell assay and an anticomplement C1q enzyme-linked immunosorbent assay were also used for measurement of Lex antigen associated with C3- and C1q-CIC, respectively. Following affinity purification of Lex-IgG complexes and subsequent dissociation of these immune complexes, human antibodies were isolated which reacted with purified glycosphingolipids containing Lex. Levels of Lex-IgG complexes were found to be 2- to 5-fold higher in eluates of Protein A-silica columns perfused with plasma from adenocarcinoma patients compared to eluates from columns perfused with plasma from healthy individuals and patients with other cancers. These assays may prove to be of diagnostic and/or prognostic significance in adenocarcinoma.

Characterization of an eye prosthesis using monopoly syrup.

The eye is a vital organ and an important component of facial expression. Loss of an eye has a crippling effect on the psychology of the patient. Maxillofacial prostheses restore and replace stomatognathic and associated facial structures with artificial substitutes. The objectives of eye prosthesis is to improve the patient esthetics, restore and maintain the health of the remaining associated structures, consequently provide physical and mental well-being. The primary purpose of an ocular prosthesis is to maintain the volume of eye socket and create the illusion of a healthy eye and surrounding tissue. A custom ocular prosthesis is a good option when reconstruction is done by plastic surgery, and osseointegrated implants are either not possible or not desired. A case of a custom-made ocular acrylic prosthesis is presented with acceptable fit, good retention, and esthetics.

Threonine 209 phosphorylation on RUNX3 by Pak1 is a molecular switch for its dualistic functions.

P21 Activated Kinase 1 (Pak1), an oncogenic serine/threonine kinase, is known to have a significant role in the regulation of cytoskeleton and cellular morphology. Runx3 was initially known for its role in tumor suppressor function, but recent studies have reported the oncogenic role of Runx3 in various cancers. However, the mechanism that controls the paradoxical functions of Runx3 still remains unclear. In this study, we show that Runx3 is a physiologically interacting substrate of Pak1. We identified the site of phosphorylation in Runx3 as Threonine 209 by mass spectrometry analysis and site-directed mutagenesis, and further confirmed the same with a site-specific antibody. Results from our functional studies showed that Threonine 209 phosphorylation in Runx3 alters its subcellular localization by protein mislocalization from the nucleus to the cytoplasm and subsequently converses its biological functions. This was further supported by in vivo tumor xenograft studies in nude mouse models which clearly demonstrated that PANC-28 cells transfected with the Runx3-T209E clone showed high tumorigenic potential as compared with other clones. Our results from clinical samples also suggest that Threonine 209 phosphorylation by Pak1 could be a potential therapeutic target and of great clinical relevance with implications for Runx3 inactivation in cancer cells where Runx3 is known to be oncogenic. The findings presented in this study provide evidence of Runx3-Threonine 209 phosphorylation as a molecular switch in dictating the tissue-specific dualistic functions of Runx3 for the first time.

Quantitation of specific antibodies bound to feline leukemia virus in the plasma of pet cats.

A method is described for determining levels of circulating immune complexes (CIC) composed of feline leukemia virus (FeLV) antigens and corresponding antibodies in plasma of persistently-infected pet cats. The procedure is based on the ability of high-titered heterologous anti-FeLV serum to chase cat anti-FeLV IgG from dissociated CIC by successfully competing for binding of free antigen. The eluted cat antibody is then collected and quantitated. In a study of cats in the process of clearing persistent FeLV infections, measured levels of FeLV-specific CIC correlated well with fluctuating levels of free FeLV antigen and antibody. The Raji cell assay for CIC in those cats was of comparatively little value in following the clearance of the virus, presumably because that assay does not distinguish between CIC containing viral and those containing non-viral antigens. The method described can be adapted to studies of specific immune complexes associated with a variety of syndromes, provided that the antigen eliciting the immune response is known.

Transcriptional regulation of fibronectin by p21-activated kinase-1 modulates pancreatic tumorigenesis.

Pancreatic ductal adenocarcinoma (PDAC) is the eighth largest cause of cancer-related mortality across the world, with a median 5-year survival rate of less than 3.5%. This is partly because the molecules and the molecular mechanisms that contribute to PDAC are not well understood. Our goal is to understand the role of p21-activated kinase 1 (Pak1) signaling axis in the progression of PDAC. Pak1, a serine/threonine kinase, is a well-known regulator of cytoskeletal remodeling, cell motility, cell proliferation and cell survival. Recent reports suggest that Pak1 by itself can have an oncogenic role in a wide variety of cancers. In this study, we analyzed the expression of Pak1 in human pancreatic cancer tissues and found that Pak1 levels are significantly upregulated in PDAC samples as compared with adjacent normals. Further, to study the functional role of Pak1 in pancreatic cancer model systems, we developed stable overexpression and lentiviral short hairpin RNA-mediated knockdown (KD) clones of Pak1 and studied the changes in transforming properties of the cells. We also observed that Pak1 KD clones failed to form tumors in nude mice. By adopting a quantitative PCR array-based approach, we identified fibronectin, a component of the extracellular matrix and a mesenchymal marker, as a transcriptional target of Pak1 signaling. The underlying molecular mechanism of Pak1-mediated transformation includes its nuclear import and recruitment to the fibronectin promoter via interaction with nuclear factor-κB (NF-κB)-p65 complex. To our knowledge, this is the first study illustrating Pak1-NF-κB-p65-mediated fibronectin regulation as a potent tumor-promoting mechanism in KRAS intact model.

Neutralizing monoclonal antibodies to the AIDS virus.

The production of neutralizing monoclonal antibodies (MAbs) will permit the exact localization of neutralizing epitopes on the AIDS virus, HIV-1. We describe the properties of seven MAbs to the envelope of the LAV-1 isolate. Five MAbs recognise the central portion of gp110, amino acids 279-472, and four of these are capable of high-titre neutralization of HIV-1, by infection inhibition, syncytial inhibition and vesicular stomatitis virus (VSV) pseudotype neutralization. One of the two MAbs to gp41 inhibits syncytium formation. Neutralization, live cell immunofluorescence and immunoprecipitation of gp110 are type-specific and restricted to HIV-1 isolates closely related to LAV-1.