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Biomedical subjects

C Song

Publications and source records attributed to C Song.

At least 127 records · Page 7Linked to original sources

[The changes of hemodynamics in ocular trauma and treatment with compound anisodine].

OBJECTIVE: To study the changes of hemodynamics in human ocular trauma and treatment with compound anisodine. METHODS: 34 cases with ocular trauma were examined by rheoophthalmography (ROG) and Doppler ultrasonography (DUSG). RESULTS: It appeared that the wave amplitudes of ROG were lower in both injured and contralateral eyes, which indicated the ocular blood flow was reduced. The speed of systolic blood flow in ophthalmic artery (OA), the value of systolic peak frequency (PK) in internal carotid artery (ICA) and common carotid artery (CCA) in DUSG were increased, indicating that there were certain degrees of blood vessel spasm in OA, ICA and CCA. CONCLUSION: Ocular trauma not only directly impairs the vasomotor function of injured eyes but also affects the vasomotor function of contralateral eyes and the function of the autonomic nervous system or cerebral cortex by consensual reaction. The treatment by compound anisodine may effectively relieve and restore the above changes and improve the visual function. ROG and DUSG are sensitive and objective to estimate the changes of hemodynamics and evaluate the therapeutic effect in ocular trauma.

Adolescent↗

[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↗

[Nucleotide sequence of HLA-DQA1 promoter region (QAP) in a lung cancer patient].

The HLA-DQA1 allele and nucleotide sequence of HLA-DQA1 promoter region (QAP) in a patient with IDDM complicated lung cancer have been identified by PCR/SSCP, PCR/SSCP and PCR/sequencing. The results showed that: (1) All of the lung cancer patient and his family members carried HLA-DQA1* 0301/0501 alleles. (2) a single base substitution G-->A at position -155 and deletion CAA at position -161 to -163 occurred in the patient. These results suggest that the mutation of HLA-DQA1 promoter region may modulate HLA-DQA1 gene expression by trans-acting factors binding to variant cis-acting elements and may be responsible for pathogenesis of lung cancer.

Alleles↗

[An experimental study on compound anisodine III for softening scar of mouse skin after burn].

OBJECTIVE: The aim of this study was to investigate the mechanism of compound anisodine (CA) III which can rapidly soften the cicatrized tissue in clinical practice. METHODS: 2 mol/L NaOH was applied onto the back of 36 mice for one minute to induce deep grade skin burn injury. After 1 week local cicatrization occurred. The mice were randomly divided into 3 groups: 1 ml saline was used in group I as control, hyaluronidase 150 U dissolved in 1 ml 2% procaine was used in group II and 0.005% CA 0.1 ml in 2% procaine 1 ml with hyaluronidase 150 U was used in group III. Subcutaneous injection once every other day for two weeks was the method of drug administration in all the 3 groups and then all the rats were euthanized. The burned skin was sectioned for HE and modified Masson's stains. RESULTS: Histopathology revealed there were epidermis proliferation, keratinization and fibrosis with disorderly arranged collagenous fibers invading into muscles and a large amount of inflammatory cells infiltrating the lesion in groups I and II. However, the skin was nearly normal in group III. CONCLUSIONS: CA III can inhibit the epidermic and collagenous proliferation, improve the tissue blood supply and have antiinflammatory effect to prevent scar formation and promote epidermic repair in the skin.

Animals↗

Behavioral, neurochemical, and immunological responses to CRF administration. Is CRF a mediator of stress?

The effect of subacute intracerebroventricular (icv 0.1, 0.5, and 1.0 microgram) administration of corticotropin-releasing factor (CRF) for 5 days on behavior, neurotransmitter concentrations, and immune functions was studied in rats. The results showed that CRF administration produced a dose-dependent increase in locomotor activity in the "open field" test compared with controls; rearing scores were also significantly increased. In the elevated plus maze apparatus, rats given 1.0 microgram CRF spent considerably less time on the open arms when compared with controls. Following 0.5 and 1.0 microgram of CRF infusion, the concentrations of noradrenaline (NA), dopamine (DA) and 5-hydroxy indole acetic acid (5-HIAA) were significantly increased in the hypothalamus. There was no significant change in the concentrations of neurotransmitters in the other brain regions. CRF administration also produced a dose-dependent increase in the levels of corticosterone in the serum. The immunological results clearly showed that subacute icv CRF administration caused a reduction of lymphocyte proliferation, a decrease in the percentage of lymphocytes, and an increase in neutrophil percentage in the differential white blood cell (WBC) count, a decrease in neutrophil phagocytosis, and elevated leucocyte adhesiveness/aggregation (LAA) compared with control animals. These results suggest that icv subacute administration of CRF has anxiogenic effects, increases biogenic amine concentrations in the hypothalamus, and changes in some aspects of immune functions that may reflect the stress-inducing properties of the peptide. These effects are time and dose dependent.

Animals↗

Requirement of a 3'-terminal stem-loop in in vitro transcription by an RNA-dependent RNA polymerase.

Partially purified RNA-dependent RNA polymerase (RdRp) isolated from plants infected with turnip crinkle virus (TCV) is capable of template-dependent synthesis of TCV-associated RNAs. To determine the cis-sequences required for the synthesis of TCV satellite (sat-) RNA C (-) strands in vitro, templates containing interior deletions were subjected to transcription using RdRp-active fractions. Results indicated that the promoter for (-)-strand synthesis was contained within the 3'-terminal 29 bases of the (+)-strand. Structural probing by enzymatic digestion and chemical modification revealed the presence of a hairpin structure within this terminal region. Compensatory exchanges of four bases in the lower stem or alterations in the sequence and size of the loop region did not affect in vitro transcription, implying that the primary sequence in the loop and lower part of the stem is not important for interaction with the viral RdRp. However, single mutations in the base of the stem or double mutations in the upper stem strongly reduced template activity in vitro, suggesting that the stability of the hairpin is an important functional consideration. Relocation of the 3'-terminal 37 bases containing this stem-loop to inactive template RNA rendered the resultant hybrid RNA competent for in vitro transcription by RdRp activity, suggesting that the promoter for (-)-strand synthesis in vitro is completely contained within the 3'-terminal region.

Base Sequence↗

[Rapid determination of the value-determining components in sausage products by near-infrared transmission spectroscopy].

A rapid method for the simultaneous determination of water, fat, crude protein, connective-tissue-protein and connective-tissue-protein free meat protein in sausage products with the help of near-infrared transmission spectroscopy (NIT) is presented. The calibrations for the each constituent were achieved with the chemometric method "partial least squares" (PLS) and validated with the added samples. Correlation coefficients between the reference methods and NIT were > or = 0.95 for water, fat, crude protein and connective-tissue-protein frei meat protein, and > or = 0.86 for connective-tissue-protein. The precision of NIT was comparable with the reference methods.

Animals↗

Rat brain cannabinoid receptors are N-linked glycosylated proteins.

To study the N-linked glycosylation properties of the CB1 receptor, rat brain membranes were treated with exo- and endoglycosidases. For visualizing CB1 receptors, an antipeptide antibody was raised against the N-terminal 14 amino acids and used to specifically detect the protein by Western blotting. We found that the apparent molecular weight of mature CB1 receptors was 64 kDa. Treatment of membranes with endoglycosidase F shifted the 64 kDa band to the 59 kDa and 53 kDa bands. The latter is consistent with the calculated molecular weight of deglycosylated CB1 receptors. Treatment of membranes with endoglycosidase H and alpha-mannosidase partially shifted the 64 kDa band to 53 kDa band, indicating a portion of the oligosaccharides was of the high mannose type. These data confirmed that the CB1 receptors in brain are N-linked glycoproteins with heterogeneous carbohydrate composition. Among three potential N-linked glycosylation sites on the N-terminus of the CB1 receptor, only two sites are actually glycosylated.

Animals↗

Superantigenic exotoxin production by isolates of Staphylococcus aureus from the Kawasaki syndrome patients and age-matched control children.

Nineteen strains of Staphylococcus aureus were isolated from the throat or the tooth surfaces of 19 cases amongst 127 patients with Kawasaki syndrome (KS) during the acute phases and 11 S. aureus isolates were obtained from five of 17 diseased controls and six healthy controls. The production of exotoxins, particularly superantigenic toxic shock syndrome toxin-1 (TSST-1), coagulase serotype, pigment production, haemolytic activity and tryptophan auxotrophy of these isolates were compared. Among 10 KS S. aureus strains isolated in 1990-1991, five (50%) secreted TSST-1, a higher frequency than two (18%) of 11 control isolates. In contrast, none of the nine KS strains collected in 1984 produced TSST-1. Four of five TSST-1-secreting KS strains produced white or white to golden pigmentation, whereas the two control strains capable of TSST-1 production formed golden colonies. There were no noticeable differences between S. aureus strains from KS patients and control children in the production of staphylococcal exotoxins A-E, coagulase serotype, haemolysis of sheep erythrocytes and tryptophan auxotrophy. The pathological or aetiological role of a new TSST-1-secreting S. aureus clone in patients with KS was not confirmed.

Bacterial Toxins↗

Synthesis of novel products in vitro by an RNA-dependent RNA polymerase.

RNA-dependent RNA polymerase from turnip crinkle virus-infected turnip transcribes both strands of a virus-associated satellite RNA, sat-RNA C (356 bases), in vitro. While both plus- and minus-strand sat-RNA C can direct the synthesis of full-length complementary-strand products, transcription of minus-strand RNA also generates two non-template-sized products, L-RNA and S-RNA (C. Song and A. E. Simon, Proc. Natl. Acad. Sci. USA 91:8792-8796, 1994). Here we report that synthesis of L-RNA and S-RNA results from terminal elongation of the 3' end of the template. L-RNA has a panhandle structure and is composed of minus-strand template covalently linked to newly synthesized RNA complementary to its 5' 190 bases. S-RNA is composed of template covalently linked to its full-length complementary strand. All minus-strand templates tested yielded S-RNA. However, synthesis of L-RNA was affected by deletion of the 3' end of the minus-strand template or several internal regions and base alterations near the 5' end or in an internal sequence immediately upstream from the template-product junction that could potentially form a heteroduplex with the 3' end. Furthermore, mutations that disrupted or restored a stem-loop involved in RNA recombination in vivo affected the level of L-RNA produced in vitro, suggesting that the mechanisms for intramolecular formation of panhandle RNAs and intermolecular RNA recombination involve similar features.

Base Sequence↗

[Effects of prostaglandin E1 (PGE1) on pulmonary hypertension and lung vascular remodeling in a rat monocrotaline model of human pulmonary hypertension].

Prostaglandin E1 (PGE1) has been shown to be a potent pulmonary vasodilator in humans and in many animals. The effects of PGE1 on the development of pulmonary hypertension and on pulmonary vascular remodeling were studied in a rat monocrotaline (MCT) model of human pulmonary hypertension. By 3 weeks after injection, MCT (80 mg/kg S.C.) had resulted in high values of mean pulmonary arterial pressure and of the ratio of right ventricular weight to left ventricle+septum weight (RV/LV+S). PGE1 inhibited the development of pulmonary hypertension (300 micrograms/kg) and right ventricular hypertrophy (300 and 100 micrograms/kg) induced by MCT. Three weeks after the injection, the media walls of pulmonary arteries in lungs from rats given MCT were significantly thicker than those from lungs of control rats. PGE1 (300, 100, and 30 micrograms/kg) resulted in significantly less of this morphologic change, in a dose-dependent manner. These results indicate that PGE1 inhibits the development of pulmonary hypertension associated with lung vascular thickening induced by MCT. PGE1 may be useful for the treatment of pulmonary hypertension in humans.

Alprostadil↗

[An experimental study on the integrated effects of heat-cleaning and detoxifying drugs and fire-purging drugs used in combination].

Heat-cleaning and detoxifying drugs and fire-purging drugs used in combination have been proved able to restore the endotoxin-induced deviant of HCT, blood viscositites, PTT and fibrinolytic activity, and reduce the blood content of both endotoxin and PGE2 in rabbits. In addition, the combination can also decrease the pes swelling percentage in rats as well as evans blue extravasation volume in mice. In practice, however, it should be noted that the bitter and cold qualities of these two kinds of drugs may be harmful to health.

Albumins↗