Interactions of total bone marrow cells with increasing quantities of macroporous calcium phosphate ceramic granules.

The biological properties of synthetic calcium phosphate bioceramics have made them the third choice of material for bone reconstructive surgery, after autologous bone and allografts. Nevertheless, bioceramics lack the osteogenic properties that would allow them to repair large bone defects. One strategy in bone tissue engineering consists of associating a synthetic scaffold with osteogenic cells. Mesenchymal stem cells (MSC) are usually isolated from bone marrow cultured for several weeks and seeded on to a small quantity of bioceramic. We have studied the association of total bone marrow cells, harvested from femurs of rats, with increasing amounts of calcium phosphate ceramic granules (50-250 mg). A cell viability test indicated that a little quantity of bioceramics granules (50 mg) was less detrimental for culturing 1 million nucleated cells from the whole bone marrow population. Cell morphology, viability, adhesion and differentiation were studied after different culture periods. Among the heterogeneous population of bone marrow cells, only a limited amount of cells attached and differentiated on the bioceramics. To explain the influence of the amount of synthetic scaffold on cell viability, media calcium concentrations were measured. Low cell viability could be explained by calcium phosphate precipitation leading to a decrease in calcium concentrations observed with relatively large amounts of scaffold. This study showed that the chemical stability of the ceramic plays a critical role in the viability of bone marrow cells.

Quality control of antibiotics before the implementation of an STD program in Northern Myanmar.

BACKGROUND: The ready availability of poor-quality drugs in developing countries leads to treatment failure and, consequently, excess mortality and morbidity. Moreover, the widespread availability of substandard drugs plays a key role in increasing the resistance to antimicrobial drugs.GOAL As a prerequisite to the establishment of a sexually transmitted disease (STD) control program, this study aimed to evaluate the quality of antibiotics recommended for treatment of STDs that were locally available in the capital of a province of Northern Myanmar. STUDY DESIGN: In addition to the hospital pharmacy, we selected at random 5 of the 41 drug sellers and 5 of the 40 general practitioners who sell antibiotics in the city of Myitkyina. Twenty-one marketing products corresponding to nine different antibiotics used for STD treatment were purchased (benzathine benzylpenicillin, benzylpenicillin, ceftriaxone, chlortetracycline, ciprofloxacin, clotrimazole, co-trimoxazole, doxycycline, and erythromycin). Drugs were sent to France, where they were analyzed according to the WHO guidelines. Drugs were considered to be standard if their dosage remained in the 10% range of the expected value. RESULTS: Among the 21 different specialty products, only three displayed the official "registered" label. Three drugs were expired and the expiration date was not available for six others. One product did not contain the active drug declared (chlortetracycline; Lombisin, Unicorn, China) and did not show any in vitro activity against bacteria. Seven of 21 products (33%) did not contain the stated dosage (1, more than stated dosage; 6, less than stated dosage). The highest deficit observed was 48% in two products (co-trimoxazole, Yong Fong, Myanmar; benzylpenicillin, China [city and manufacturer unknown]). The dosage was not available for five drugs. As a result, only 8 of 21 products (38%) did not contain the stated dosage of active drug. CONCLUSION: These findings suggest that public health policies based on national treatment guidelines should rigorously include the monitoring of quality control of available antimicrobial products. In the absence of such measures, specific treatment strategies are likely to fail and to generate drug resistance.