Stability and Intra-Individual Variation of Urinary Malondialdehyde and 2-Naphthol / 예방의학회지

OBJECTIVES: Malondialdehyde (MDA), a lipid peroxidation by-product, has been widely used as an indicator of oxidative stress. Urinary 2-naphthol, a urinary PAH metabolite, is used as a marker of ambient particulate exposure and is associated with lung cancer and chronic obstructive pulmonary disease. However, the stability and intra-individual variation associated with urinary MDA and 2-naphthol have not been thoroughly addressed. The objective of this study was to assess the stability and intraindividual variation associated with urinary MDA and 2-naphthol. METHODS: Urine samples were collected from 10 healthy volunteers (mean age 34, range 27~42 years old). Each sample was divided into three aliquots and stored under three different conditions. The levels of urinary MDA and 2-naphthol were analyzed 1) just after sampling, 2) after storage at room temperature (21degrees C) for 16 hours, and 3) after storage in a -20degrees C freezer for 16 hours. In addition, an epidemiological study was conducted in 44 Chinese subjects over a period of 3 weeks. The urinary MDA and 2-naphthol were measured by HPLC three times. RESULTS: There was no difference in the levels of urinary MDA and 2-naphthol between the triplicate measurements (n=10, p=0.84 and p=0.83, respectively). The intra-class correlation coefficients (ICC) for urinary MDA and 2-naphthol were 0.74 and 0.42, respectively. However, the levels of PM2.5 in the air were well correlated with the levels of both MDA and 2-naphthol in the epidemiological study. CONCLUSIONS: These results suggest that urinary MDA and 2-naphthol remain stable under variable storage conditions, even at room temperature for 16 hours, and indicate that these markers can be used in epidemiological studies involving various sample storage conditions. The intra-CC of urinary 2-naphthol and MDA were acceptable for application to epidemiological studies.

Granulocytic sarcoma of breast: an aleukemic presentation.

Granulocytic sarcoma is a rare extramedullary tumor composed of immature myeloid cells. It is usually associated with leukemia or other myeloproliferative disorders but can also occur without overt hematologic diseases. The breast is an uncommon site of presentation and requires a high index of suspicion for diagnosis. We report such a case in a 45-year-old female, who presented with nontender left breast lump of 6 months' duration. A peripheral smear and bone marrow examination at that time was normal. A lumpectomy was done. An H and E diagnosis of lobular carcinoma vs. non-Hodgkin's lymphoma was entertained. Immunostains, however, revealed myeloperoxidase, naphthol AS-D chloroacetate esterase and CD43 positivity, indicating a diagnosis of granulocytic sarcoma. It appears that early initiation of systemic AML-type chemotherapy is beneficial and may delay or avert the development of AML in bone marrow and blood. Eight months later, the patient presented with an orbital mass; bone marrow and peripheral smear involvement by AML.

Hydrolysis of organophosphorus compounds by an esterase isozyme from insecticide resistant pest Helicoverpa armigera.

Esterase activity of resistant and susceptible H. armigera were compared in gels with different substrate such as naphthyl acetate, naphthyl phosphate, paraoxon and monocrotophos. Whole body extract of resistant H. armigera hydrolyzed paraoxon, monocrotophos and naphthyl phosphate in gels. Resistant H. armigera showed high esterase, phosphatase and paraoxon hydrolase activity compared to susceptible ones.