Publications by authors named "Kshama Mehta"

Background And Objective: Starting dialysis is a life-changing transition for people living with kidney disease. People feel overwhelmed with diet changes, medications and surgical interventions, and often experience high levels of anxiety, depression and hospital admissions. The objective of this study was to explore and describe the experiences and perspectives of people starting dialysis.

View Article and Find Full Text PDF

Background And Objectives: IgA nephropathy is the most common primary glomerular disease in the world. Marked by mesangial inflammation and proliferation, it generally leads to progressive kidney fibrosis. As the Janus kinase signal transducer and activator of transcription pathway has been implicated as an important mediator of diabetic kidney disease and FSGS, detailed investigation of this pathway in IgA nephropathy was undertaken to establish the basis for targeting this pathway across glomerular diseases.

View Article and Find Full Text PDF

Focal segmental glomerular sclerosis (FSGS) is a devastating disease with limited treatment options and poor prognosis. Activated JAK-STAT signaling has been implicated in other kidney diseases. Since new technologies allow us to better evaluate changes in systemic and renal JAK-STAT activity as it relates to kidney function, we examined this in 106 patients with biopsy-proven FSGS compared to 47 healthy control individuals.

View Article and Find Full Text PDF

IgA nephropathy frequently leads to progressive CKD. Although interest surrounds use of immunosuppressive agents added to standard therapy, several recent studies have questioned efficacy of these agents. Depleting antibody-producing B cells potentially offers a new therapy.

View Article and Find Full Text PDF

Background: A recent classification of membranoproliferative glomerulonephritis (MPGN) utilizes the presence of immunoglobulin and complements to simplify diagnosis and point towards disease etiology. Here, we evaluate a historic cohort of patients with idiopathic MPGN using the new classification system and correlate it with clinical outcome.

Methods: We identified 281 patients diagnosed with MPGN at Stanford from 2000 to 2012.

View Article and Find Full Text PDF

Unlabelled: Acquired tamoxifen resistance develops in the majority of hormone-responsive breast cancers and frequently involves overexpression of the PI3K/AKT axis. Here, breast cancer cells with elevated endogenous AKT or overexpression of activated AKT exhibited tamoxifen-stimulated cell proliferation and enhanced cell motility. To gain mechanistic insight on AKT-induced endocrine resistance, gene expression profiling was performed to determine the transcripts that are differentially expressed post-tamoxifen therapy under conditions of AKT overexpression.

View Article and Find Full Text PDF

Background And Objectives: Adrenocorticotropic hormone (ACTH) has shown efficacy as primary and secondary therapy for nephrotic syndrome due to membranous nephropathy. The data on using ACTH to treat idiopathic FSGS are limited. This report describes our experience using ACTH for nephrotic syndrome due to idiopathic FSGS in the United States.

View Article and Find Full Text PDF

Background: Transforming growth factor beta (TGFβ) is upregulated in chronic inflammation, where it plays a key role in wound healing and promoting fibrosis. However, little is known about the peripheral effects of TGFβ on nociception.

Methods: We tested the in vitro effects of TGFβ1 on the excitability of dorsal root ganglia (DRG) neurons and the function of potassium (K) channels.

View Article and Find Full Text PDF

We have previously shown that pancreatic sensory neurons in rats with chronic pancreatitis (CP) display increased excitability associated with a decrease in transient inactivating potassium currents (I(A)), thus accounting in part for the hyperalgesia associated with this condition. Because of its well known role in somatic hyperalgesia, we hypothesized a role for the nerve growth factor (NGF) in driving these changes. CP was induced by intraductal injection of trinitrobenzene sulfonic acid (TNBS) in rats.

View Article and Find Full Text PDF

Background: Natural orifice translumenal endoscopic surgery (NOTES) and laparoendoscopic single-port surgery (LESS) are emerging approaches to abdominal surgery that have been advocated as potentially causing fewer physiologic derangements and less pain. This study aimed to compare these procedures in a novel rat model by assessing peritoneal inflammation, gastric motility, and nociception in response to peritoneoscopy performed via NOTES and LESS.

Methods: Adult male rats underwent peritoneoscopy via either transgastric NOTES or LESS using the same type of endoscope and were allowed to recover for 2 to 4 h.

View Article and Find Full Text PDF

Aims: A disturbance of the brain-gut axis is a prominent feature in functional bowel disorders (such as irritable bowel syndrome and functional dyspepsia) and psychological abnormalities are often implicated in their pathogenesis. We hypothesized that psychological morbidity in these conditions may result from gastrointestinal problems, rather than causing them.

Methods: Functional dyspepsia was induced by neonatal gastric irritation in male rats.

View Article and Find Full Text PDF

Objectives: We examined the role of brain-derived neurotrophic factor (BDNF) in the pathogenesis of pain in an experimental model of chronic pancreatitis (CP).

Methods: Pancreatitis was induced by retrograde infusion of trinitrobenzene sulfonic acid into the pancreatic duct of adult rats. Twenty-one days after injection, BDNF expression was examined in pancreas-specific dorsal root ganglia (DRGs) by immunohistochemistry, and protein levels were quantified from DRGs and spinal cord extracts.

View Article and Find Full Text PDF

Background & Aims: The pathogenesis of pain in chronic pancreatitis (CP) is poorly understood and treatment remains difficult. We hypothesized that nerve growth factor (NGF) plays a key role in this process via its effects on the transient receptor potential vanilloid 1, TRPV1.

Methods: CP was induced by intraductal injection of trinitrobenzene sulfonic acid in rats.

View Article and Find Full Text PDF

Studies of embryonic stem cells (ESCs) reveal that these cell lines can be derived from differing stages of embryonic development. We analyzed common changes in the expression of microRNAs (miRNAs) and mRNAs in 9 different human ESC (hESC) lines during early commitment and further examined the expression of key ESCenriched miRNAs in earlier developmental states in several species. We show that several previously defined hESC-enriched miRNA groups (the miR-302, -17, and -515 families, and the miR-371-373 cluster) and several other hESC-enriched miRNAs are down-regulated rapidly in response to differentiation.

View Article and Find Full Text PDF

Differences between individual DNA sequences provide the basis for human genetic variability. Forms of genetic variation include single-nucleotide polymorphisms, insertions/duplications, deletions, and inversions/translocations. The genome of human embryonic stem cells (hESCs) has been characterized mainly by karyotyping and comparative genomic hybridization (CGH), techniques whose relatively low resolution at 2-10 megabases (Mb) cannot accurately determine most copy number variability, which is estimated to involve 10%-20% of the genome.

View Article and Find Full Text PDF

Background: Fibrates are a unique hypolipidemic drugs that lower plasma triglyceride and cholesterol levels through their action as peroxisome proliferator-activated receptor alpha (PPARalpha) agonists. The activation of PPARalpha leads to a cascade of events that result in the pharmacological (hypolipidemic) and adverse (carcinogenic) effects in rodent liver.

Results: To understand the molecular mechanisms responsible for the pleiotropic effects of PPARalpha agonists, we treated mouse primary hepatocytes with three PPARalpha agonists (bezafibrate, fenofibrate, and WY-14,643) at multiple concentrations (0, 10, 30, and 100 microM) for 24 hours.

View Article and Find Full Text PDF

Regional DNA hypermethylation and global DNA hypomethylation are 2 epigenetic alterations associated with colorectal cancers. However, their correlation with microsatellite instability (MSI) and chromosomal instability (CIN) in colorectal cancer, and their relationship with chromatin conformation and histone modification are not clear. In this study, we analyzed regional and global methylation in 16 cell lines and 64 primary colorectal cancers.

View Article and Find Full Text PDF

Purpose: Bladder carcinogenesis is believed to follow alternative pathways of disease progression driven by an accumulation of genetic alterations. The purpose of this study was to evaluate associations between measures of genomic instability and bladder cancer clinical phenotype.

Experimental Design: Genome-wide copy number profiles were obtained for 98 bladder tumors of diverse stages (29 pT(a), 14 pT1, 55 pT(2-4)) and grades (21 low-grade and 8 high-grade superficial tumors) by array-based comparative genomic hybridization (CGH).

View Article and Find Full Text PDF

Models of bladder tumor progression have suggested that genetic alterations may determine both phenotype and clinical course. We have applied expression microarray analysis to a divergent set of bladder tumors to further elucidate the course of disease progression and to classify tumors into more homogeneous and clinically relevant subgroups. cDNA microarrays containing 10,368 human gene elements were used to characterize the global gene expression patterns in 80 bladder tumors, 9 bladder cancer cell lines, and 3 normal bladder samples.

View Article and Find Full Text PDF

Purpose: Although liver resection is the primary curative therapy for patients with colorectal hepatic metastases, most patients have a recurrence. Identification of molecular markers that predict patients at highest risk for recurrence may help to target further therapy.

Experimental Design: Array-based comparative genomic hybridization was used to investigate the association of DNA copy number alterations with outcome in patients with colorectal liver metastasis resected with curative intent.

View Article and Find Full Text PDF

Array-based comparative genomic hybridization (CGH) allows for the simultaneous examination of thousands of genomic loci at 1-2 Mb resolution. Copy number alterations detected by array-based CGH can aid in the identification and localization of cancer causing genes. Here we report the results of array-based CGH in a set of 125 primary colorectal tumors hybridized onto an array consisting of 2463 bacterial artificial chromosome clones.

View Article and Find Full Text PDF

Human pituitary adenomas are the most common intracranial neoplasm. Typically monoclonal in origin, a somatic mutation is a prerequisite event in tumor development. To identify underlying pathogenetic mechanisms in tumor formation, we compared the difference in gene expression between normal human pituitary tissue and clinically nonfunctioning pituitary adenomas by cDNA-representational difference analysis.

View Article and Find Full Text PDF

Tumor suppressor p53 induces the cellular response to DNA damage mainly by regulating expression of its downstream target genes. The human securin is an anaphase inhibitor, preventing premature chromosome separation through inhibition of separase activity. It is also known as the product of the human pituitary tumor-transforming gene, pttg, a proto-oncogene.

View Article and Find Full Text PDF