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Biomedical subjects

T Z Yang

Publications and source records attributed to T Z Yang.

6 recordsLinked to original sources
PubMed2001

In vitro and in vivo study of two types of long-circulating solid lipid nanoparticles containing paclitaxel.

Paclitaxel (Taxol), a diterpenoid isolated from Taxus brevifolia, is effective against several murine tumors, and is one of the most exciting anticancer molecules currently available. Due to its low solubility in water, it is clinically administered with polyethoxylated castor oil (Cremophor EL), which causes serious side effects. Inclusion of paclitaxel in solid lipid nanoparticles (SLNs) has proved to be a good approach to eliminate the need for Cremophor EL and improve the drug's antitumor efficacy. This paper describes the development of two types of long-circulating SLNs as colloidal carriers for paclitaxel. SLNs are constituted mainly of bioacceptable and biodegradable lipids. In vitro release kinetics showed that the release was very slow, the release of paclitaxel from F68-SLN is linear, and the release of paclitaxel from Brij78-SLN followed the Weibull equation. Pharmacokinetics was evaluated in KM mice after injection of paclitaxel formulated in Cremophor EL or in Brij78-SLN and F68-SLN. Encapsulation of paclitaxel in both SLNs produced marked differences compared with the free drug pharmacokinetics. F68-SLN and Brij78-SLN are long-circulating (t 1/2 beta, 10.06 and 4.88 h, respectively) compared with paclitaxel injection (t 1/2 beta, 1.36 h).

Animals↗
PubMed2001

[Research on a new side-chain liquid crystalline polysiloxane as stationary phase for capillary column gas chromatography].

A new stationary phase, side-chain liquid crystalline polysiloxane, was obtained and used in capillary column gas chromatography. Two kinds of side-chain polysiloxane, PSI5 and PSI6, were characterized by polarized light microscopy (POM), differential scanning calorimetry (DSC) and X-ray diffraction and proved to be smectic phase Sc. Two fused-silica capillary columns (0.25 mm i.d.) were coated with 5 g/L solutions of PSI5 and PSI6 in dichloromethane by the static method, named column 15 and column 16. Numbers of theoretical plate were 1,598/m-2,423/m (I5) and 3,191/m-4,235/m (I6) for anthracene at 200 degrees C-240 degrees C. These columns showed wide operation temperature range (I5: 50 degrees C-200 degrees C; I6: 100 degrees C-260 degrees C), outstanding thermostability and weak polarity. These columns exhibited unique selectivity for many organic compounds, especially positional isomers. For example, the mixtures of anthracene, phenanthrene and fluorene were well separated on column I5 and I6; dimethyl benzene isomers were well separated on column I5, but they were not separated on column I6; dimethyl phenol isomers were well separated on column I5, but they were not wholly separated on column I6. The different selectivities of these columns are mainly due to the different chemical structures.

Calorimetry, Differential Scanning↗
PubMed2000

[Alien chromosomal identification in VE161 wheat].

VE161 wheat which has the function of promotting homoeologous pairing is a male sterile substitution line or a fertile addition line with one pair of alien chromosomes from Agropyron elongatum. The alien chromosome in VE161 wheat was detected by means of techniques of total genomic DNA in situ hybridization, RFLP and double-ditelo chromosomal analysis. The results from in situ hybridization confirmed that the alien chromosome was derived from Agropyron elongatum. The RFLP analysis showed that it belongs to fourth homoeologous group, and the results from double-ditelo chromosomal analysis gave evidence that 4B chromosome was replaced in the substitution line, so it can be concluded that, in VE161 wheat, the alien chromosome would be 4E and the replaced wheat chromosome would be 4B in the substitution line. The reason for the replaced chromosome identified as 7B in a earlier study might be due to the rearrangement occurred in the genome of wheat.

Chromosomes↗
PubMed1994

[Detection of uterine scar defect during pregnancy by ultrasonics].

B type ultrasonography was used to observe the formation of lower uterine segment in 71 primigravide and the status of lower uterine segment scar in 31 multiparae with previous cesarean section (CS), from the 33 to 41 gestational week. Results showed that the lower uterine segments was formed in all 102 cases after the 33rd week. Compared with the primigravide, the lower uterine segment in the CS group was longer, thinner and not as wide after the 37th gestational week. Defective scars of the lower uterine segment were found in 7 cases of the CS group and 2 of them were diagnosed as threatened dehiscence owing to the fetal sac protruding from the scar site. Condition of all these cases were confirmed during operation. The present study suggested that B ultrasonic scar can be a helpful and noninvasive method for detecting scar defect in the lower uterine segment following CS.

Cicatrix↗
PubMed1985

The efferent projections from the reticular formation and the locus coeruleus studied by anterograde and retrograde axonal transport in the rat.

Following injections of [3H]leucine into the formatio reticularis gigantocellularis (Rgc), reticularis pontis caudalis (Rpc), reticularis pontis oralis (Rpo), reticularis mesencephali (Rmes), or the locus coeruleus (LC) of the rat, autoradiographic study revealed prominent reticuloreticular projections from all areas and secondary projections onto cranial nerve motor nuclei from most areas within the brain stem. Common long descending projections extended the full length of the spinal cord terminating in the ventromedial ventral horn and intermediate zone and more sparsely in the base of the dorsal horn and (particularly from Rgc) the region of the motoneurons. Common long ascending projections extended into the forebrain via Forel's tegmental fascicles. A dorsal branch of fibers innervated the intralaminar and midline nuclei of the thalamus. The major fiber system continued forward through Forel's fields and ascended into the pallidum from Rpo, Rmes, and LC and into the neostriatum from Rmes and LC. Fascicles from all areas also ascended in the medial forebrain bundle through the lateral hypothalamus to the lateral preoptic area, substantia innominata, and nuclei of the diagonal band. From Rpo, Rmes, and LC, fibers continued forward to reach the cerebral cortex, where the innervation was sparse and discrete from Rpo and Rmes but moderate and ubiquitous from LC. Retrograde transport of true blue and/or nuclear yellow revealed inverse gradients along the brain stem longitudinal axis of interdigitated cells respectively projecting caudally into the spinal cord (with the greatest number of cells in Rgc, Rpc, and Rpo) and rostrally into the diencephalon (with the greatest number of cells in Rmes and LC), with very few cells projecting both to the spinal cord and the diencephalon. From the basal forebrain, a large number of reticular and LC cells were retrogradely labelled, whereas from the frontal cortex, a much smaller number of reticular cells was labelled. These results document the widespread efferent projections from the reticular formation and overlapping, yet more extensive, projections from the LC.

Amidines↗