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H M Li

Publications and source records attributed to H M Li.

50 records · Page 3Linked to original sources
PubMed1991

SP-like immunoreactivity in the primary trigeminal neurons projecting to the nucleus tractus solitarii.

Using the double-labeling method of retrograde transport of HRP combined with PAP immunocytochemistry, the neurons containing SP-like immunoreactivity (SPLI) of the trigeminal nerve projecting to the nucleus tractus solitarii (NTS) were examined. HRP-SP double-labeled neurons in the trigeminal ganglion, mainly small or middle-sized, were found after the NTS or the lingual nerve was injected with HRP followed by SP-immunoreaction. These findings demonstrate that the projection of the trigeminal nerve to the NTS contains SPLI.

Animals↗
PubMed1991

Targeting of proteins to the outer envelope membrane uses a different pathway than transport into chloroplasts.

The chloroplastic envelope is composed of two membranes, inner and outer, each with a distinct set of polypeptides. Like proteins in other chloroplastic compartments, most envelope proteins are synthesized in the cytosol and post-translationally imported into chloroplasts. Considerable knowledge has been obtained concerning protein import proteins. We isolated a cDNA clone from pea that encodes a 14-kilodalton outer envelope membrane protein. The precursor form of this protein does not possess a cleavable transit peptide and its import into isolated chloroplasts does not require either ATP or a thermolysin-sensitive component on the chloroplastic surface. These findings, together with similar observations made with a spinach chloroplastic outer membrane protein, led us to propose that proteins destined for the outer membrane of the chloroplastic envelope follow an import pathway distinct from that followed by proteins destined for other chloroplastic compartments.

Adenosine Triphosphate↗
PubMed1991

Projections from neurons innervating the masseter muscle to the subnucleus oralis of the spinal trigeminal nucleus and adjacent lateral reticular formation in the rat.

The projection from the masseter to the subnucleus oralis of the spinal trigeminal nucleus (Vo) and adjacent parvicellular reticular nucleus (PCRt) was studied with retrograde and transganglionic transport of horseradish peroxidase (HRP) combined with fluorescent double labeling method. The labeled axons and terminals within the medulla showed a specific distribution. The field of labeling formed a continuous band from rostro-laterally to caudo-medially. At the level of caudal Vo the labeling region became the most expanded in the medulla, which occupied dorso-medial Vo (Vodm) and adjacent PCRt about half by half. The ratio of masseter primary afferent neurons in the mesencephalic trigeminal nucleus (Vme) to that in the trigeminal ganglion (TG) was found to be 7.7-8.5:1 following injection of HRP into the masseter nerve. However, the proportion between the Vme and the TG neurons which build up the pathway from the masseter to the Vodm and the adjacent PCRt was 8.7-10:1, revealed by means of fluorescent double labeling when different tracers were applied at the peripheral and central targets.

Animals↗
PubMed1990

Metal-ion-center assembly of ferredoxin and plastocyanin in isolated chloroplasts.

Most chloroplastic proteins are cytosolically synthesized and posttranslationally transported to their proper locations. Two examples of this group of proteins are ferredoxin and plastocyanin, both of which are metal-containing components of the photosynthetic electron-transport chain. The import process for these two proteins includes the insertion of the metal ions to produce the holo forms of the proteins. We show here that in vitro translated precursor proteins of ferredoxin and plastocyanin are synthesized as apo forms and are assembled into their respective holo forms after being imported into isolated chloroplasts. We also provide evidence that only mature-sized proteins are competent to be assembled into holo forms.

Journal Article↗
PubMed1990

Selection of recombinant vaccinia viruses (Tian Tan strain) expressing hepatitis B virus surface antigen by using beta-galactosidase as a marker.

We constructed a plasmid that contains a small piece of DNA with two vaccinia promoters running in opposite directions--a promoter from a late gene encoding an 11 K polypeptide (P11) and a promoter from an early gene encoding 25K (P25). These promoters were isolated from the Tian Tan strain of vaccinia virus and were flanked by the thymidine kinase (TK) sequence of the same virus. Genes encoding the hepatitis B virus surface antigen (HBsAg) and the Escherichia coli beta-galactosidase (LacZ) were inserted downstream of the 11 K and 25 K promoters respectively so that coexpression plasmids were constructed. Recombinant vaccinia viruses were selected directly by picking blue plaques formed under overlaying agarose medium containing X-gal. HBsAg was expressed to high level by these recombinant viruses. These recombinant viruses showed reduced virulence on rabbit skin and induced anti-HBs after intradermal inoculation of rabbits.

Animals↗
PubMedDate not supplied

Monte Carlo simulation of secondary electron and backscattered electron images in scanning electron microscopy for specimen with complex geometric structure.

A new Monte Carlo technique for the simulation of secondary electron (SE) and backscattered electron (BSE) of scanning electron microscopy (SEM) images for an inhomogeneous specimen with a complex geometric structure has been developed. The simulation is based on structure construction modeling with simple geometric structures, as well as on the ray-tracing technique for correction of electron flight-step-length sampling when an electron trajectory crosses the interface of the inhomogeneous structures. This correction is important for the simulation of nanoscale structures of a size comparable with or even less than the electron scattering mean free paths. The physical model for electron transport in solids combines the use of the Mott cross section for electron elastic scattering and a dielectric function approach for electron inelastic scattering, and the cascade SE production is also included.

Journal Article↗