Search PubMed⌕ Search

Biomedical subjects

C Li

Publications and source records attributed to C Li.

At least 901 records · Page 50Linked to original sources
PubMed1996

In vitro release and permeation of oxytocin from a mucoadhesive buccal patch.

A biocompatible, mucoadhesive patch was evaluated for potential use in the delivery of peptides. The model peptide oxytocin was incorporated into the polymeric patch matrix and the diffusion of oxytocin across excised rabbit buccal epithelium was studied following patch application. Penetration of oxytocin across excised mucosa from an applied patch did not exhibit a characteristic lag time for diffusion, with the steady-state flux of oxytocin being 0.062 +/- 0.019 microgram/cm2/hr. However, when finite-dose diffusion studies were conducted to quantitate transport of oxytocin across rabbit buccal mucosa, the mean apparent permeability coefficient (P), diffusion coefficient (D), partition coefficient (K), and lag time (tlag) were (1.94 +/- 0.74) x 10(-7) cm/sec, (9.20 +/- 1.65) x 10(-8) cm2/sec, 0.13 +/- 0.05 and 1.86 +/- 0.31 hr, respectively. The release of oxytocin from the mucoadhesive buccal patches in vitro proceeded very rapidly during the first 2 hr, with 72% of the amount initially incorporated into the patches released at 24 hr. The disappearance rate of intact, parent oxytocin when an oxytocin solution was placed in direct contact with the serosal and mucosal sides of freshly excised rabbit buccal mucosa was 0.74 +/- 0.34 microgram/cm2/hr and 3.38 +/- 1.07 micrograms/cm2/hr, respectively. Thus, the buccal patch evaluated in these studies appears to be suitable for transmucosal delivery of peptides.

Adhesives↗
PubMed1996

[Studies on Cnidium fruits by stereological method and computer image analysis].

The fruits, pollen grains, vascular bundles, stomata and endosperm cells of 4 Cnidium species were studied and determined by stereological method and computer image analysis technique. Statistical data were presented. In the volume of fruit and the area of vascular bundle, Cnidium dahuricum is the biggest, then C. salinum, C. japonicum and C. monnieri successively. In the volume of pollen grain,C. salinum is the biggest, followed by C. dahuricum, C. japonicum and C. monnieri in succession. In the volume of endosperm cell, C. dahuricum is also the biggest, and then C. japonicum, C. salinum and C. monnieri in order.

Fruit↗
PubMed1996

Histological and electron-microscopic observations on the mucosa of pediculate gastric wall graft transplanted to the intestines in Wistar rats.

OBJECTIVE: To study the machanism of the development of intestinal metaplasia through the transplantation of a flap of gastric wall with vascular pedicle to the intestines. METHODS: The pedicled gastric wall flaps of Wistar rats were transplanted to their duodenum, jejunum and colon respectively. After the operation the rats were killed at the 3th, 6th, 9th and 12th month respectively, and histological change of the gastric grafts was observed with optical and electron microscopy. RESULTS: Intestinal metaplasia was found in all the gastric grafts transplanted to the intestines and the alkaline phosphatase positive intestinal metaplasia was seen in the gastric graft mucosa transplanted to the duodenum and jejunum. CONCLUSIONS: The formation of intestinal metaplasia in the gastric mucosa may be related to a change of the microenvironment around the tissues, and gastric mucosa may differentiate into intestinal mucosa by the increase of pH value. The possible mechanism of the development of intestinal metaplasia was discussed.

Anastomosis, Surgical↗
PubMed1996

[Immune and biochemical analysis of protein of homogenates of three different kinds of skin].

The amount and constitution of protein, its ultraviolet photo-absorption ability, and esterase in homogenates of human cadaveric and guinea pig skin (each consisted of newborn, fresh adult and stored adult skin) were assayed by using ultraviolet spectrophotometer, polyacrylamide gel electrophoresis and sodium dodecyl sulphate polyacrylamide gel electrophoresis. Our experiment shows that immune and biochemical analysis of protein of three different skin groups are different. The biochemical components of cadaveric and guinea pig skin protein and esterase in newborn skin group are lowest. The changes in adult skin stored at -196 degrees C are less obvious as compared with that in fresh adult skin.

Animals↗
PubMed1996

[Chemical constituents of Coleus carnosifolius Dunn].

Four compounds were isolated from Coleus carnosifolius. They were identified as betulic acid, betulin, oleanic acid and beta-sitosterol by spectral analysis and comparison with authentic samples.

Drugs, Chinese Herbal↗
PubMed1996

Bernard-Soulier syndrome with severe bleeding: absent platelet glycoprotein Ib alpha due to a homozygous one-base deletion.

Bernard-Soulier syndrome is a rare congenital platelet disorder that affects a surface membrane adhesion receptor, glycoprotein (GP) Ib-V-IX. Both the genetic defects and the bleeding diatheses associated with the syndrome are heterogeneous due, in part, to the complexity of the involved receptor which consists of four different members, GPs: Ib alpha-Mr 143 K (contains the von Willebrand factor-binding site), Ib beta-Mr 22 K, V-Mr 83 K and IX-Mr 20 K. We studied a kindred that includes a 40 year-old man with severe Bernard-Soulier syndrome: life-threatening gastrointestinal bleeding, thrombocytopenia, giant platelets and absent ristocetin-dependent platelet aggregation. By Southern blotting, PCR amplification/sequencing, hetero-duplex analysis, and allele-specific oligonucleotide hybridization, the Ib-V-IX genes were analyzed, and the molecular genetic defect was defined as a one-base deletion in the GPIb alpha gene, involving an adenine of codon 19. The mutation, K19R, homozygous in the propositus and heterozygous in the available unaffected relatives, leads to a frame shift in codons 19-21 and a premature stop codon after codon 21. No functional GPIb alpha can be produced from the mutant allele, implying that the platelets of the affected patient lack all GPIb alpha. Within the spectrum of Bernard-Soulier syndrome, this patient's disorder exemplifies a severe or "classic" extreme; an "experiment of Nature" that illustrates the effect of a complete deficiency of the ligand-binding chain (GPIb alpha) of the GPIb-V-IX receptor.

Adult↗
PubMed1996

Antitumor activity of thevetoside in vitro.

OBJECTIVE: To study the effects of thevetoside (TS), a cardiac glycoside, and an inhibitor of Na+, K(+)-ATPase, on tumor cells cultured in vitro. METHODS: The cytotoxic effects of TS on tumor cells were determined by trypan blue dye exclusion, neutral red vital staining and clonogenic assay. The time-effect relationship and growth inhibition of tumor cells by TS were assayed with trypan blue exclusion method. RESULTS: TS at low doses (0.005-0.1 mg.L-1), with dose dependence, was able to kill SMMC-7721, SGC-7901 and HeLa cells. IC50 values for SMMC-7721, SGC-7901 and HeLa cells were 0.007, 0.011 and 0.018 mg.L-1 by trypan blue dye exclusion test and 0.016, 0.055 and 0.078 mg.L-1 by neutral red vital staining test. TS inhibited the clonal forming rate of SMMC-7721 and SGC-7901 significantly with IC50 values of 0.021 and 0.036 mg.L-1, respectively. Only when the cells were continuously treated with TS for more than 8 hours, the drug-induced cell lethality could be displayed and strengthened quickly. The growth of tumor cells was notably inhibited after they were exposed to 0.1 microgram/ml of TS for 12 hours. All the experimental results of antitumor activity in vitro showed that SMMC-7721 was most sensitive to TS among the three kinds of tumor cells. CONCLUSIONS: TS has cytotoxic action on tumor cells cultured in vitro and this lethal effect must have an action process, in which tumor cells are not dead but suffer from deadly injury and lost the capability of unlimited proliferation.

Adenocarcinoma↗
PubMed1996

[Dynamic assay of oleanolic acid in Aralia taibaiensis Z. Z. Wang et H. C. Zheng].

The dynamic assay on oleanolic acid (OA) in Aralia taibaiensis shows that the plant has a higher OA level. The level in root cortex is 4.74%-10.81% and peak stages are mid-May to late June and late August to mid-September the level in stem barks is 3.59%-12.06% and peak period is between mid-May and late July, the level in leaves increases throughout the life time ranging from 2.41% to 6.66% and peak level is 6.66% around mid-September.

Drugs, Chinese Herbal↗
PubMed1996

[Restoration of external auditory canal by filling mastoid cavity with carbon pellet].

To prevent infection of an open mastoid cavity after mastoidectomy and improve hearing, the external auditory canal had been maintained on 72 cases (73 ears) by filling mastoid cavity with carbon pellet. The average duration of dry ear after operation was 25 days with a dry ear rate being 98.6%. No phenomenon of rejection and falling out appeared within 1-7 years follow-up. Carbon pellet has advantages of chemical stability, nontoxicity, good histocompatability, anti-fatigue characteristic in body fluid, and anti-corrosive effect against acid, base and salt.

Adolescent↗
PubMed1996

[Epidemiological survey of Graves' disease on a hundred thousand people in Daging area].

OBJECTIVE: To study the incidence of Graves' disease and associated factors. METHODS: A total of 100123 people aged 15-79 in Daqing region were surveyed epidemiologically. The investigations were conducted for an average two years. RESULTS: 301 patients with Graves' disease were newly diagnosed, 74 of them (1.6/1000) were males and 227 (4.1/1000) females. The total incidence was 3.0/1000. The incidence had significant differences between ages and occupations. Investigations of 18 associated factors for Graves' disease by using the Logistic multivariate regression analysis showed the following pathological factors, virus history, psychological stimulation, food, drugs, family history, education, distributions, etc. CONCLUSION: This study may provide the theoretical evidence for prevention and treatment of Grave's disease.

Adolescent↗
PubMed1996

[Expression of thyrotropin receptor gene in autoimmune thyroid disease and the relation to expression of HLA genes].

OBJECTIVE: To investigate the expression of TSH receptor in autoimmune thyroid disease (AITD) and the relation to expression of HLA I and II genes. METHODS: The TSH receptor transcript levels were examined in 10 human thyroid fragments by Northern blot analysis. Graves' disease 7, Hashimoto's disease 2, and 1 healthy thyroid gland. RESULTS: TSH receptor transcript levels were higher in Graves' disease than in Hashimoto's disease and healthy control. CONCLUSION: TSH receptor expression was inversely related to HLA I and II expression and lymphocyte infiltration.

Gene Expression↗
PubMed1996

Transfer of marker genes into hemopoietic progenitor cells.

Ex vivo gene marking of normal and malignant hemopoietic cells allows the cells to be subsequently tracked in vivo. Marking has shown that even when marrow is in remission, it may contain malignant cells that contribute to relapse. These studies have also shown that it is possible to obtain long-term gene expression in human long-lived hemopoietic progenitor cells and T lymphocytes in vivo. Current marker studies use two distinguishable vectors to track two distinctively treated cell populations in a single individual. This modification greatly increases the power of the technique. It is now possible to study the effects of purging on residual malignant cells in marrow, to determine the action of growth-promoting agents (such as cytokines and stroma) on short- and long-term repopulation by transduced marrow, and to discover which phenotypic subsets of hemopoietic progenitor cells have long-term repopulating potential. The information gained will be invaluable for improving therapeutic gene transfer protocols in which marrow-derived cells are the targets.

Bone Marrow Cells↗
PubMed1996

[The changes in firing rates of ventromedial hypothalamic neurons and its modulations by electroacupuncture, arcuate nucleus and locus coeruleus during the immune response].

30 adult SD rats were divided into 3 grous: normal control goup; SRBC immune group (on 5th day after SRBC injection) and MSG(MSG injection at newborn stage) + SRBC group. The changes of the spontaneous firing rates of ventromedial hypothalamus (VMH) neurons and evoked responses by electroacupuncture (EA) and locus coeruleus (LC) stimulation were recorded. The results were as follows: (1) The spontaneous firing rate of VMH neurons was significant increase in the SRBC group. The firing rate in the MSG + SRBC group was higher than that in the control group, and lower than that in the SRBC group. There were statistical differences between them. (2) EA can increase the firing rates in all groups. The effect of EA was the most significant in the SRBC group, and more significant in the MSG + SRBC group. (3) The firing type of most VMH neurons showed first excited then inhibited biphasic response following stimulation LC in the SRBC and the MSG + SRBC groups. EA showed some increase in effect of the excited modulation from LC to VMH in the SRBC group. The results suggest that VMH might be an important neuroendocrinal link in immunoresponse. EA can increase the immune function of SRBC on VMH. LC and beta-endorphine neurons of arcuate nucleus might participate in the EA mediated immunoresponse.

Animals↗
PubMed1996

[Effect of acupuncture combined with peridural anesthesia on SCE and RNA/DNA of lymphocytes].

In the present paper, three anesthetic methods including acupuncture combined with peridural anesthesia of small dose of anesthics used in subtotal gastrectomy are introduced. Changes in SCE (sister chromatid exchange) contents of RNA and DNA and RNA/DNA before, during and after operation are measured in 14 patients. Results suggest that acupuncture combined with peridual anesthesia, acupunctrue anesthesia and peridual anesthesia all have no any effect in inducing mutation, carcinoma and aberration.

Acupuncture Analgesia↗
PubMed1996

[Changes of peripheral blood stem cells of patients with malignant hematopoietic tumor after chemotherapy].

To investigate the most appropriate condition for collecting stem cells during peripheral blood stem cells transplantation (PBSCT), we used colony forming unit-granulocyte, macrophage (CFU-GM) as index to observe the change of PBSC after chemotherapy in 12 patients with malignant hematopoietic tumor. The results showed that it was more suitable to collect PBSC when the number of leucocytes was 2 x 10(9)/L, neutrophils 0.8 x 10(9)/L and platelets 110 x 10(9)/L after chemotherapy for 2 weeks. After chemotherapy, the number of leucocytes were suppressed evidently. On the contrary, a lot of CFU-GM appeared during the recovery phase of peripheral hemogram. At the nadir of peripheral hemogram, the number of leucocytes correlated negatively with the number of CFU-GM (P < 0.05). The longer the time of chemotherapy, the less the CFU-GM that in the same patients. After chemotherapy the CD34+ cells which appeared early might not form CFU-GM, but the CD34+ cells at the recovery phase of peripheral hemogram had the same trend of change with CFU-GM.

Adolescent↗