Regulatory mechanism of miR-29 over TGF-ß1 and COL1 in scar cells.

OBJECTIVE: To study the regulatory mechanism of miR-29 over TGF-ß1 and COL1 in scar cells. PATIENTS AND METHODS: 5 clinical cases of hypertrophic scar (HS) skin and adjacent normal skin tissues were separated into fibroblast for primary culture and subculture before being observed morphologically and standard HE staining under an ordinary optical microscope. RT-PCR method was applied to test the expression level of miR-29, TGF-ß1, and COL1 mRNA. ELISA method was applied to test the expression level of extracellular matrix COL1, fibronectin (FN) and α-SMA. The miR-29 overexpression vector was built and transfected in vitro. RT-PCR method was applied to test related genes and ELISA method was applied to test the expression level of the extracellular matrix. RESULTS: The color of karyon and cytoplasm of normal fibroblast were both light red, with little ECM. The color of karyon of scar fibroblast was blue. The cytoplasm was red of different degrees, with relatively much ECM, in deep blue color. Compared with that in the normal fibroblast group, the miR-29 mRNA in fibroblast in the scar group significantly decreased (p<0.05). The TGF-ß1 and COL1 mRNA significantly increased (p<0.05). The COL1, FN and α-SMA level were significantly higher (p<0.05) than that in the normal group. These mRNAs levels in miR-29 overexpression group were lower than scar group but higher than the normal group. CONCLUSIONS: The expression of miR-29 which regulates the expression of TGF-ß1 and COL1 and increases the level of ECM significantly decreases in scar cells. This one suggests a mechanism of the formation of the scars through TGF-ß1 and COL1.

Prediction of urinary and fecal nitrogen excretion by beef cattle.

An analysis of predicting urinary and fecal N excretion from beef cattle was conducted using a data set summarizing 49 published studies representing 180 treatment means for 869 animals. Variables included in the data set were initial BW (kg), DMI (kg/d), dietary CP content (% of DM), N intake (g/d), apparent total tract N digestibility (%), and urinary and fecal N excretion (g/d). Correlation analysis examined relationships between animal and dietary variables and N excretion. A mixed model regression analysis was used to develop equations to predict N excretion in urine and feces and the proportion of urinary N in total N excretion as a function of various animal and dietary variables. Of the single animal and dietary variables, N intake was the best predictor of N excretion in urine and feces, whereas apparent total tract N digestibility was best to predict the proportion of urinary N in total N excretion. Low prediction errors and evaluation of the equations using cross-validation indicated the prediction equations were accurate and robust. Urinary and fecal N excretion can be accurately and precisely predicted by N intake, whereas the proportion of urinary N in total N excretion was best predicted solely using apparent total tract N digestibility.

Immunological studies of homosexual men with immunodeficiency and Kaposi's sarcoma.

Acquired immunodeficiency and Kaposi's sarcoma are epidemic among homosexual men in the United States. We have identified three clinically distinct disease syndromes in homosexually active men: a syndrome of severe cellular immunodeficiency including infection with Pneumocystis carinii and other opportunistic pathogens, a syndrome of chronic benign lymphadenopathy without severe opportunistic infections, and Kaposi's sarcoma. All 46 patients which we have studied with these three disease syndromes shared a common immune abnormality, that being a reduction in the circulating T-lymphocyte subpopulation bearing the Leu-3/OKT-4 antigen. The second major T-lymphocyte subpopulation, which bears the Leu-2/OKT-8 antigen, was numerically normal in all the disease syndromes, but increased as a percentage of all circulating lymphocytes. These abnormalities resulted in an inversion of the normal ratio of these two lymphocyte subpopulations. A similar, but less pronounced imbalance in circulating T-lymphocyte subpopulations was observed in a group of healthy homosexual men. The immune deficiency in these patients was most evident in the T-cell component of the immune system. Percentages of B cells, circulating immunoglobulin levels, and natural killer (NK) and antibody-dependent cell-mediated cytoxic (ADCC) functions were normal. Proliferative responses to antigen and mitogen were typically decreased in patients with the acquired immunodeficiency syndrome and some Kaposi's sarcoma patients, but not those with the prolonged lymphadenopathy syndrome or a control group of healthy homosexual men. Possible causes or factors contributing to the immunodeficiency and interrelationships among the three disease manifestations are discussed.