Amelioration of radiation-induced hematopoietic syndrome by an antioxidant chlorophyllin through increased stem cell activity and modulation of hematopoiesis

Hematopoietic stem cells and progenitor cells (HSPC) are low in abundance and exhibit high radiosensitivity and their ability to divide dramatically decreases following exposure to ionizing radiation. Our earlier studies have shown antiapoptotic, immune-stimulatory, and antioxidant effects of chlorophyllin, a constituent of the over the counter drug derifil. Here we describe the beneficial effects of chlorophyllin against radiation-induced hematopoietic syndrome. Chlorophyllin administration significantly enhanced the abundance of HSPC in vivo. It induced a transient cell cycle arrest in lineage-negative cells in the bone marrow. However, the chlorophyllin-treated mice exposed to whole body irradiation (WBI) had a significantly higher proportion of actively dividing HSPC in the bone marrow as compared to only WBI-exposed mice. It significantly increased the number of colony forming units (CFUs) by bone marrow cells in vitro and spleen CFUs in irradiated mice in vivo. Pharmacokinetic study showed that chlorophyllin had a serum half-life of 141.8 min in mice. Chlorophyllin upregulated antiapoptotic genes and antioxidant machinery via activation of prosurvival transcription factors Nrf-2 and NF-κB and increased the survival and recovery of bone marrow cells in mice exposed to WBI. Chlorophyllin stimulated granulocyte production in bone marrow and increased the abundance of peripheral blood neutrophils by enhancing serum levels of granulocyte-colony stimulation factor (GCSF). Most importantly, prophylactic treatment of mice with chlorophyllin significantly abrogated radiation-induced mortality. Chlorophyllin mitigates radiation-induced hematopoietic syndrome by increasing the abundance of hematopoietic stem cells, enhancing granulopoiesis, and stimulating prosurvival pathways in bone marrow cells and lymphocytes.

19. Prevalence of diagnostic discordance: A retrospective analysis of autopsy findings and clinical diagnoses

The prevalence of medical error in health care systems has compromised the quality of health care delivery. The research on medical errors in hospitalized population has consistently revealed high rates of misdiagnosis. Autopsy examination has been an established tool for quality assurance programs. The objective of this study was to determine the discrepancy rates between clinical and autopsy findings in patients admitted to various hospitals (Royal University hospital, RUH; St. Paul’s hospital, SPH; Saskatoon city hospital, SCH) of Saskatoon Health Region. A retrospective record review of the medical and autopsy charts was carried out for all the deceased adult in-patients admitted during the years 2002, 2003, and 2004. All autopsies were carried out either in the morgue of RUH or at SPH hospital. A total of 3416 in-patient deaths were registered during the study period. Autopsies were performed on 206 of the deceased resulting in an autopsy rate of 6%. In accordance with selection criteria, 158 cases were included for this study. The mean age of subjects was 66.6 ± 15.2 years with a range of 16 – 94 years. The total concordance rate in this study between clinical and autopsy diagnoses was 75.3%. The discordance rate was 20.9% and in 3.8% of the study population a conclusive clinical or autopsy diagnoses was not finalized. The concordance and discordance rate between clinical diagnoses and autopsy findings when compared between the patients of two hospitals (RUH and SPH) were not significantly different. These results suggest that despite the technical advances in medical and diagnostic modalities, there still persists a significant discordance in clinical and autopsy diagnoses. Our study confirms the wide prevalence of diagnostic discrepancies in the health care system and emphasizes the value of autopsy as an effective quality improvement and educational tool with a strong impact on quality management. Roosen J, Frans E, Wilmer A, Knockaert DC, Bobbaers H. Comparison of premortem clinical diagnoses in critically ill patients and subsequent autopsy findings. Mayo Clin Proc 2000; 75:562-67. Sonderegger-Iseli K, Burger S, Muntwyler J, Salomon F. Diagnostic errors in three medical eras: a necropsy study. Lancet 2000; 10355:2027-31. Kalra J. Medical Error: An Introduction to Concepts. Clinical Biochemistry 2004;37:1043-51.