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Biomedical subjects

M Lu

Publications and source records attributed to M Lu.

363 records · Page 21Linked to original sources

Blood lead levels in children in south central Los Angeles.

We retrospectively reviewed 3 679 pediatric records from King/Drew Medical Center, south central Los Angeles, between 1991 and 1994. Blood lead levels of children were followed to age 18 y. Patients were not referred specifically for lead poisoning. The sample was primarily Latino. Geometric mean blood lead peaked at 6.7 micrograms/dl (0.32 mumol/l) between 2 and 3 y of age. There was a downward secular trend and a seasonal trend. Males had higher lead levels than females. Children who lived in several zipcode areas, in which the lowest family incomes were reported, had higher lead levels. More Latino children had higher lead levels than African American children. Latino children (i.e., 20.2%) who were 1-5 y of age had blood lead levels that were > or = 10 micrograms/dl. Young Latino children in this zone of Los Angeles may be at increased risk for lead exposure.

Adolescent↗

Proteasome inhibitor and lymphocyte function: partial inhibition of cell-mediated cytotoxicity and implication that the lymphocyte proteasome may contain multiple chymotryptic domains.

The multicatalytic proteinase complex or proteasome possesses at least 4 distinct proteolytic activities. We have previously reported that the chymotrypsin-like activity of the rat natural killer cell proteasome may play a role in natural killer (NK) cell-mediated cytotoxicity or IL-2 activated NK (A-NK) cell-mediated cytotoxicity. Using a series of novel, Cephalon, Inc, synthetic proteasome inhibitors (CEP-1508, CEP-1612 and CEP-3117) which have been reported to be specific for the chymotrypsin-like activity of the proteasome, we have further investigated the possible role of the proteasome, with emphasis on the chymotryptic activity components, in cell-mediated cytotoxicity. We now report that these compounds can inhibit the rat NK proteasome in a dose dependent manner. Nevertheless, there is only a 50% inhibition of A-NK cell-mediated cytotoxicity. These results confirm and extend our previous results that the proteasome contributes, at least in part, to cell-mediated cytotoxicity. However, as anticipated, since multiple molecular pathways contribute to cell-mediated cytotoxicity, the proteasome contributes only partially to NK cell-mediated cytolytic reactivity. The exact role of the proteasome in NK cell-mediated killing, and whether single or multiple chymotryptic domains function directly or indirectly, remains to be fully determined.

Animals↗

Intratumoral injection of boiling carboplatin (BCBP) solution for treatment of liver cancer in the animal model.

BACKGROUND/AIMS: To develop a new modality of local hyperthermal chemotherapy for liver cancer. METHODOLOGY: Carboplatin solutions of various concentrations were heated at 60 degrees C, 80 degrees C and 100 degrees C, and carboplatin content, pH value and ultraviolet absorption spectrum were assayed before and after heating. By establishing BALB/c murine model of subcutaneous transplant liver cancer, intratumoral injection of boiling carboplatin solution (group A), 45 degrees C carboplatin solution (group B), room-temperature carboplatin solution (group C), boiling distilled-water (group D) and room-temperature distilled-water (control group) was carried out, and tumor growth curve, tumor regression rate and pathohistological features following treatment were evaluated. RESULTS: Carboplatin content remained stable, ultraviolet absorption spectrum presented no remarkable changes and pH value showed a slight decline after being heated for up to 20 min. Following treatment, all 16 tumors in group A were completely regressed up to day 21. In groups B, C and control group, no tumors became fully regressed and a size of 1.98 +/- 1.11 cm2, 1.50 +/- 0.58 cm2 and 4.83 +/- 0.37 cm2 was presented on day 21, respectively. In group D, though all tumors grossly disappeared during the early post-treatment days, 12 out of 16 recurred on day 21. The tumor regression rate in group A was significantly lower as compared with that of groups B, C, D and control group (all P < 0.01). Histological examination revealed massive necrosis with some degenerated tumor cells at the tumor margin in groups A and D, and only focal necrosis with more viable tumor cells at the center and margin in groups B and C on post-treatment day 1 and 3. Twenty-one days after injection, all tumors in group A presented complete necrosis and were partly replaced by fibrotic tissue. Except for 4 regressed tumors in group D which had the same histological features as those in group A, all other tumors in groups B, C, D and control group presented the same histological features as those untreated. CONCLUSIONS: Carboplatin solution remained stable at boiling status. Intratumoral injection of boiling carboplatin solution could completely devitalize liver cancer tissue via synergistic effects of direct tumoricidal role of heat and the heat-enhanced tumoricidal role of carboplatin.

Animals↗