Mandelic acid was produced from racemic mandelonitrile by Akcaligenes faecalis ATCC 8750. Ammonium acetate or L-glutamic acid as the carbon source and n-butyronitrile as the inducer in the culture medium were effective for bacterial growth and the induction of R-(-)-mandelic acid-producing activity. The R-(-)-mandelic acid formed from mandelonitrile by resting cells was present in a 100% enantiomeric excess. A. faecalis ATCC 8750 has an R-enantioselective nitrilase for mandelonitrile and an amidase for mandelamide. As R-(-)-mandelic acid was produced from racemic mandelonitrile in a yield of 91%, whereas no S-mandelonitrile was left, the S-mandelonitrile remaining in the reaction is spontaneously racemized because of the chemical equilibrium and is used as the substrate. Consequently, almost all the mandelonitrile is consumed and converted to R-(-)-mandelic acid. R-(-)-Mandelic acid was also produced when benzaldehyde plus HCN was used as the substrate.

String-shaped reconstituted smooth muscle (SM) fibers were prepared in rectangular wells by thermal gelation of a mixed solution of collagen and cultured SM cells derived from guinea pig stomach. The cells in the fiber exhibited an elongated spindle shape and were aligned along the long axis. The fiber contracted in response to KCl (140 mM), norepinephrine (NE; 10(-7) M), epinephrine (10(-7) M), phenylephrine (10(-6) M), serotonin (10(-6) M), and histamine (10(-5) M), but not acetylcholine (10(-5) M). Phentolamine (10(-7) M) produced a parallel rightward shift of the NE dose-response curve. Moreover, NE-induced contraction was partially inhibited by nifedipine and completely abolished by the intracellular Ca(2+) chelator 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid acetoxymethyl ester, the myosin light chain kinase inhibitor ML-9, the Rho kinase inhibitor Y-27632, and papaverine. A [(3)H]quinuclidinyl benzilate binding study revealed that the loss of response to acetylcholine was due to the loss of muscarinic receptor expression during culture. The expression of contractile proteins in the fibers was similar to that in cultured SM cells. These results suggest that, although the fiber is not a model for fully differentiated SM, contractile mechanisms are maintained.

To characterize the functional differentiation of neural stem cells into smooth muscle cells, multipotent stem cells in the central nervous system (CNS) were isolated from rat embryonic day 14 (E14) cortex and cultured by neurosphere formation in serum‐free medium in the presence of 10 ng ml−1 of basic fibroblast growth factor. Differentiation was induced by the addition of 10 % fetal bovine serum to low‐density cultures (2.5 × 103 cells cm−2). Immunological analyses and reverse transcriptase‐polymerase chain reaction indicated that the differentiated cells expressed smooth‐muscle‐specific marker proteins such as SM‐1, SM‐2, and SMemb myosin heavy chains, SM‐22, basic calponin and α‐smooth‐muscle actin, but not the astrocyte marker glial fibrillary acidic protein. To examine whether smooth‐muscle‐like cells that are differentiated from CNS stem cells possess the characteristics of contractile smooth muscle, we prepared reconstituted collagen gel fibres and measured their contractile tension. The reconstituted fibres were prepared by thermal gelation of collagen and the differentiated cells. The fibres contracted in response to treatment with KCl (80 mm), ACh (100 μm), endothelin‐1 (10 nm), endothelin‐2 (10 nm), and prostaglandin F2α (100 μm). ACh‐induced contraction was partially inhibited by the L‐type voltage‐dependent Ca2+ channel inhibitor nifedipine and by the intracellular Ca2+ chelator 1,2‐bis (2‐aminophenoxy) ethane‐N,N,N’,N'‐tetraacetic acid acetoxymethyl ester, the myosin light chain kinase inhibitor ML‐9, the Rho kinase inhibitor Y‐27632, dibutyryl cAMP and 8‐bromo‐cGMP. These results suggest that CNS stem cells give rise to smooth muscle cells in vitro that have an identical contractile function to smooth muscle in vivo.

Previous work has implicated the cytokine leukemia inhibitory factor (LIF) in cutaneous inflammation, although results have differed as to whether LIF is pro- or anti-inflammatory in this setting. We examined edema, inflammatory cell infiltration, and cytokine responses following CFA injection in the adult mouse footpad. Inflammatory cell infiltration and edema are significantly enhanced when CFA is injected in LIF knockout mice as compared with injection of wild-type littermates. Moreover, local injection of an adenoviral vector encoding LIF suppresses both measures of inflammation. In contrast, injection of an adenoviral vector encoding β-galactosidase has no discernable effect on inflammation. In addition, comparison of the CFA responses in LIF knockout vs wild-type skin reveals that LIF is an important regulator of IL-1β, IL-6, IL-7, IL-2Rα, and IFN-γ in cutaneous inflammation. These and our previous data indicate that both endogenous and exogenous LIF are anti-inflammatory in the CFA model and that LIF is a key regulator of the cytokine cascade. The results also indicate that adenoviral gene delivery can be an effective therapeutic approach in this paradigm.

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