Ashok Singh

Publications (2)7.09 Total impact

• Source

  Available from: tswj.com

  Article: Type B lactic acidosis secondary to malignancy: case report, review of published cases, insights into pathogenesis, and prospects for therapy.

  Juan P Ruiz, Ashok K Singh, Peter Hart
  [show abstract] [hide abstract]
  ABSTRACT: Most of the information about type B lactic acidosis associated with cancer is derived from case reports and there are no randomized controlled trials to compare different therapeutic modalities. Previous reviews of cases only refer to hematologic malignancies. We present a patient with non-Hodgkin's lymphoma who developed type B lactic acidosis. We performed a search of the PUBMED database using the MESH terms "neoplasms" AND "acidosis, lactic", limited to the English language, and written between the years 2000 and 2010. A total of 31 cases were retrieved. These cases were identified and reviewed. The possible pathophysiologic mechanisms and treatment options are discussed. Type B lactic acidosis is most commonly seen in patients with lymphoma or leukemia. Although formal prospective trials are lacking, type B lactic acidosis in patients with cancer seems to be a marker of poor prognosis regardless of the treatment offered and may be invariably fatal. Future research should focus on potential therapy based on the pathogenic mechanisms that lead to type B lactic acidosis in cancer patients.
  TheScientificWorldJOURNAL 01/2011; 11:1316-24. · 1.66 Impact Factor
• Article: Decreased urinary peptide excretion in patients with renal disease.

  Ashok Singh, Krishnamurthy P Gudehithlu, Gigi Le, Natalia O Litbarg, Viorica Khalili, Jane Vernik, Peter Hart, Jose A L Arruda, George Dunea
  [show abstract] [hide abstract]
  ABSTRACT: Normal urine contains low-molecular-weight peptides or protein fragments that have been poorly studied, primarily because of the technical difficulty of measuring peptides in the presence of proteins. We studied these substances in healthy subjects and patients with renal disease and varying degrees of proteinuria to understand the factors that determine their excretion. We estimated these substances as the difference between results using the Lowry method (which detects both proteins and peptides) and those obtained using the dye-binding Bradford (Biorad) method (Biorad Laboratories Inc, Hercules, CA; which detects only proteins). We validated this 2-assay approach to measure peptide levels by showing that such proteins as immunoglobulin G, albumin, and lysozyme were measured equally by the Lowry and Biorad methods, whereas degraded proteins were recognized by the Lowry method only, but not by the Biorad method. We found that healthy subjects excreted less than 200 mg of protein, but 3 to 4 g of peptides/g creatinine; thus, peptides constituted approximately 95% of total protein material excreted in urine. Patients with renal disease and proteinuria had a progressive decrease in peptide excretion, ranging from 3 to 0 g/g creatinine. Twenty-five percent of nephrotic patients (18 of 72 patients) excreted very small amounts of peptides in urine (0% to 10% of total protein material). We found that healthy persons excrete substantial amounts of peptides in urine, and this excretion decreases in the presence of proteinuric renal disease. It is possible that these peptides in urine arise from the tubular degradation of filtered proteins and exocytosis of protein fragments toward the urinary side, a process that becomes increasingly impaired as proteinuria increases.
  American Journal of Kidney Diseases 01/2005; 44(6):1031-8. · 5.43 Impact Factor