K L Eckert | Search PubMed

PubMed1996

Tissue engineering scaffolds using superstructures.

Here, scaffolds as cell and tissue carriers are approached from an engineering point of view, emphasizing material superstructuring in the design of supports. Superstructure engineering provides optimal spatial and nutritional conditions for cell maintenance by the arrangement of structural elements (e.g. pores or fibres) so as to vary the order of cell to cell contact. This approach is illustrated in the design of several scaffolds: knitted fabrics as three-dimensional superstructures for optimized osteosynthesis implants, a new injectable open porous implant system, an angiopolar non-degradable ceramic cell carrier, and an injectable or microsurgically implantable entangled carrier system. The implications for tissue engineering are discussed.

Anisotropy↗

PubMed1996

A single-sample, subcutaneous gonadotropin-releasing hormone test for central precocious puberty.

OBJECTIVE: We compared a rapid, subcutaneous (SQ), single-sample gonadotropin-releasing hormone (GnRH) stimulation test with the standard multiple-sample, intravenous (IV) GnRH stimulation test used in the evaluation of central precocious puberty (CPP). METHODS: We evaluated 22 patients presenting with evidence of precocious puberty. GnRH (100 microg) was administered subcutaneously in the clinic setting with single serum luteinizing hormone (LH) measured 40 minutes after injection. A standard IV GnRH stimulation test was performed within 2 weeks, with serum LH obtained at 0, 20, 40, and 60 minutes. LH was assayed by immunochemiluminometric assay. RESULTS: The mean peak LH levels after IV and SQ testing were identical. A significant correlation (r = .88) was found between the LH determined by SQ stimulations and the peak LH determined by IV GnRH testing. CPP was diagnosed (LH, >/- 8 IU/L) by both SQ and IV testing in 7 of 22 patients and was excluded by both tests in 14 of 22 patients. A diagnostic discrepancy between peak IV and SQ results was seen in 1 patient. CONCLUSIONS: We conclude that mean GnRH-stimulated LH levels from rapid SQ and standard IV testing are indistinguishable and that individual LH levels by each method are strongly correlated. A rapid SQ GnRH test is a valid tool for laboratory confirmation of CPP.

Age Determination by Skeleton↗