Biomedical subjects
Publications and source records attributed to B Yang.
78 subjects were presented with an hypothetical situation in which they were considering committing suicide after being, afflicted with cancer. Their decision to commit suicide was affected by the anticipated pain from the chemotherapy and by the probability of survival, suggesting that suicide can be a national choice.
OBJECTIVE: To clarify some biological behaviors of Plasmodium vivax including the periodical infectivity of gametocytes for mosquitoes, the prepatent period, the incubation period, the relapse patterns and their relationship. METHODS: Laboratory reared Anopheles sinensis were fed through fetal membrane on blood from patients naturally infected with vivax malaria. After feeding at different hours, the engorged mosquitoes kept in the insectarium were dissected 5-7 days later. The percentage of mosquitoes infected and the mean number of oocysts per gut were taken as criteria of the viability of the gametocytes. The healthy volunteers artificially infected by mosquito bite or quantitative inoculation of sporozoites were treated with 1.5 g chloroquine base alone before and after the first and subsequent onset of fever to detect the natural course of disease in human body. RESULTS: The infection in mosquitoes can readily be divided into upward, peak, downward and non-infective period. The infectivity reached a peak at interschizogony period and fell to low level at the time when schizogony occurred. The short incubation period was frequently observed in persons bitten by 10 infected mosquitoes or 10 000 sporozoites inoculated and the long incubation period was constantly recorded in cases receiving 100 sporozoites. When one mosquito was allowed to feed on volunteers or 1 000 sporozoites were injected, the incubation period may be short or prolonged. CONCLUSIONS: The 48-hour cycle in the infectivity of gametocyte for mosquitoes was demonstrated and the peak of oocyst production preceded the peak of parasitaemia by 1 to 3 days. Prompt radical treatment is extra important. Since the incubation period is variable depending on the number of sporozoites inoculated and the tropical versus temperate zone malaria is not all-inclusive, the classification of tertian malaria might be reconsidered.
OBJECTIVE: To evaluate the therapeutic effects of automated lamellar keratoplasty combined with excimer laser keratectomy (ALK-E) for the correction of high myopia. METHODS: With the automated corneal shaper and Keracor 116 excimer laser, ALK-E was performed on 47 eyes of 40 cases with myopia of -8.00 to -30.00 diopters (mean, -14.55D +/- 5.14D) and the highest astigmatism 7.00D. Postoperatively, all patients have been followed up for at least 3 months. RESULTS: The refractive status and visual acuity tend to be stable about 1 month postoperatively. For myopes below -15.00D, the mean refraction was -1.33D +/- 1.05D at 3 months, and 66.7% achieved their preoperative best corrected visual acuity. For myopes over -15.00D, the mean refraction was -2.42D +/- 1.84D at 3 months and 52.9% achieved their preoperative best corrected visual acuity. CONCLUSIONS: The early therapeutic results of ALK-E for treatment of high myopia are very promising. However, the operative techniques, parameters and remote therapeutic results remain to be further studied.
Muscarinic receptors are believed to play an important role in modulation of ciliary action in respiratory system. We studied the in vitro effect of methacholine, a beta-methyl ester of acetylcholine, on the ciliary beat frequency (CBF). Adenoid explants were cultured in Minimum Essential Medium Eagle (MEM). CBF was determined using microphotometry. Methacholine (10(-6) M) increased CBF a maximum of 10.34 +/- 0.42% (p < 0.001). The non-selective muscarinic antagonist atropine (10(-6) M) significantly inhibited the ciliostimulatory effects of methacholine (p < 0.001). To characterize the muscarinic receptor subtypes in nasal mucosa, the selective M1-, M2- and M3-muscarinic antagonists pirenzepine dihydrochloride (PZ), gallamine triethiodide (gallamine), and 4-diphenylacetoxy-N-methylpiperidine methiodide (4-DAMP) were used prior to addition of methacholine, PZ and 4-DAMP, at concentrations of 10(-6) to 10(-8) M, significantly inhibited the ciliostimulatory effects of methacholine (p < 0.0001). There was no significant inhibition of methacholine-induced ciliostimulation by gallamine (p > 0.3). Our study showed that ciliostimulation by methacholine in human upper airway mucosa involves M1- and M3- muscarinic receptor subtypes, but not the M2-receptor subtype. The identification of the muscarinic receptor subtypes and intracellular signalling mechanisms involved in CBF modulation will permit the selection appropriate of pharmacological agents for treating the cholinergic symptoms of rhinitis.
Pleural fluids obtained from 26 patients with tuberculous pleurisy (T-group), 11 with parapneumonic pleurisy (B-group) and 21 with malignant pleurisy (M-group) were tested for their biologic parameters and cytokine concentrations. 1) The average age of T-group was over 10 years lower than that of M-group with a statistically significant difference. 2) The average CRP value of B-group and the positivity on PPD skin test of T-group were higher than those of the other groups, respectively. 3) Yellowish pleural fluids were mainly observed in T- and B-group, while bloody pleural fluids were mostly seen in M-group with a statistically significant difference. The average total protein amount and adenosine deaminase value in pleural fluid significantly increased in T-group. The percentage of polymorphonuclear leukocytes showed a significant increase in B-group, while lymphocytes significantly increased in T-group with a statistically significant difference. 4) Although no significant difference in concentrations of IL-1 beta, IL-2, IFN-gamma and TNF-alpha in serum was noticed among the three groups, the average concentrations of IFN-gamma and TNF-alpha in pleural fluid in T-group were significantly higher than those in the other groups. 5) TNF-alpha-mRNA of mononuclear cells in pleural fluid was strongly expressed in 3 out of 11 patients of T-group, while no expression was observed in 6 patients of M-group. In conclusion, the measurement of concentrations of two kinds of cytokines in pleural fluid, IFN-gamma and TNF-alpha, may be clinically useful for the differential diagnosis of tuberculous pleurisy from parapneumonic pleurisy and malignant pleurisy.
The relative ratios of vessel lumen area/total area (EA/TA), vessel wall area/total area (MA/TA) and vessel wall thickness/vessel external diameter (WD/TD) of intra-acinar arteries were studied with image analysor in 35 rats of experimental pulmonary artery hypertension and outcomes of treatment. All the rats were divided into control group (R0), hypertension group (R1) and treated groups (R2), (R3) and (R4). The results showed relative ratios of EA/TA decreased significantly in the palmonary artery hypertension group in comparison with the control and treated groups, while the values of WA/TA and WD/TD increased significantly. The results may be valuable for morphological quantitative study, diagnosis of pulmonary artery hypertension and prediction of the disease prognosis.
OBJECTIVE: To study the regulative effects of rhIL-1 beta or rhTNF-alpha on the expression of intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) on human mesangial cells (HMC). METHODS: At the 4th, 8th, 16th and 32nd hours after stimulation by rhIL-1 beta (25 ng/ml) or rhTNF alpha (100 ng/ml), the mRNA expression of ICAM-1 and VCAM-1 on HMC was determined with Northern blot, and their protein expression was also tested with cell ELISA analysis. RESULTS: mRNA and protein of both ICAM-1 and VCAM-1 were only basically expressed on HMC at very low levels in the control groups without stimulation. After stimulation by rhIL-1 beta or rhTNF alpha, however, their expression was markedly upregulated. The maximal mRNA expression level of ICAM-1 stimulated by rhTNF alpha was present at the 8th hour, but in the remaining groups the maximal mRNA expression levels of ICAM-1 or VCAM-1 were all present at the 4th hour. Compared with control groups, ICAM-1 protein expression was significantly increased from the 4th hour after rhIL-1 beta stimulation (P < 0.05), but in the remaining groups ICAM-1 or VCAM-1 protein expression was significantly raised from the 8th hour after stimulation (P < 0.001). CONCLUSION: These results suggest that upregulated expression of ICAM-1 and VCAM-1 by inflammatory cytokines IL-1 beta and TNF alpha may play a pathogenic role in glomerulonephritis.
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In order to evaluate the effectiveness of early detection for primary liver cancer (PLC), a randomized, prospective study was performed in Shanghai from 1992 to 1995. The study population was 35 through 55 years of age, with serum evidence of HBV infection or tory of chronic hepatitis. Seventeen thousand nine hundred and twenty individuals were randomly to allocated screening group and control group. In the screening group, every individual was checked up by serum AFP test and ultrasound every 6 months and in the control group, they were unchecked. After a mean time of 1.2 years, 38 patients with PLC in the screening group were detected while 18 patients with PLC occur in the control group. In patients from the screening group, 76.8% were in subclinical stage, 70.6% of them were treated by surgical resection with 1-, 2-year survival rate of 88.1% and 77.5%, respectively. However, in the control group, none of patients was in subclinical stage, none of the tumors resected, and none of patients survived over 1 year. The lead time was estimated to be 0.45 years. The cost for detecting an early stage PLC patient is RMB 12,600 (US$1,500). The study indicates that screening in the high risk population of PLC can detect patients in early stage, increase the resection rate and the survival rate. Screening program for PLC carried out in high risk populations is thus recommended.
The paper deals with the treatment of the pulmonary artery hypertention in rats caused by monocrotaline with garlicin, liqustrazine and berbamine and studies the relationship between the function and structure of pulmonary artery and pulmonary artery hypertension before and after use of hypotensive agents. The results show that there is a close relationship between the function and structure of pulmonary artery and pulmonary hypertension, and the inhibitory effect of garlicin is the strongest among the three herbal medicines. The pathogenesis is also studied.
Angiotensin II (A II) was significantly increased in both acutely and chronically stressed animals as found in brain, heart, blood vessels and adrenal glands. After running a race, the plasma A II contents of sportsmen similar to cortisol increased markedly too. In the chronical stress-hypertensive animals, the contents of circulating A II and tissue A II were increased quite lastingly. It was also found that the high concentration of A II may stimulate the adrenal gland secreting glucosteroid, and increase of tissue A II may be faciliated by the activation of beta adrenergic receptors. On basis of the above finding, we tend to assume that A II is a stress hormone and the renin angiotension system (RAS) is a stress hormone responses system. Morever there exists a close relation between RAS and two classic stress hormone response systems, i.e. the hypothalamus-pituitary-adrenal cortex system and the sympathetic-adrenal medulla system.
OBJECTIVE: To investigate the wound healing of the cornea following 193 mm excimer laser photorefractive keratectomy (PRK) and the effects of corticosteroid on it. METHODS: PRK was performed on both eyes of 6 monkeys. Corticosteroid was given to the right eyes, but not to the left ones. At 4 days, 1 week, 2 weeks, 1 month, 3 months and 6 months, corneal pachymetry was examined and the eyes of one monkey were enucleated and the corneas were stained immunohistochemically for collagen type III, type IV and type VII, fibronectin and laminin. RESULTS: The expression of collagen type Vii recovered to the normal linear patter at 1 month. With corticosteroid, the deposition of collagen type III and fibronectin was markedly reduced and the pachymetry of central cornea was closer to the expected value. CONCLUSION: This study suggests that corticosteroid help to minimize the postoperative myopic regression and corneal haze after PRK.
The contents of 3 active compounds psoralen, isopsoralen and poisonous bakuchiol in 5 differently processed samples of Fructus Psoraleae were analysed by GC. The results indicate that the content of psoralen and isoporalen in the sample processed by the method of "Leigong's theory of processing" are 3-4 times that in the salt-fried sample, while the content of poisonous bakuchiol shows a tendency to decrease.
AIM: To clarify the role of DL111-IT when combined with mifepristone (Mif) on termination of early pregnancy. METHODS: Progesterone receptors (PR) was measured using radioligand assay (RA), and peroxidase-antiperoxidase (PAP) immuno-histochemistry. Decidual cells (DC) were estimated using cell culture and histological examination (HE) (including fetus). RESULTS: DL111-IT 100 mg.kg-1 i.m., Mif 5 mg.kg-1 i.g., DL111-IT 16 mg.kg-1 i.m. + Mif 1.5 mg.kg-1 i.g. and tea seed oil (TSO) 2 mL.kg-1 i.m. on d 7 of pregnancy in rats, DC and fetus of treated groups were found to be degenerated at 24 h after treatment, at 48 h after treatment, PAP labeling index (%) of uterus PR of 4 groups were 22 +/- 4, 18.7 +/- 2.9, 10.3 +/- 1.2, 52 +/- 15, respectively. Rats i.m. DL111-IT 100 mg.kg-1 24 h after treatment, the quantity of PR decreased by 47% vs that of TSO. The affinity of PR with Mif and progesterone did not change. Cultured human DC were exposed to DL111-IT and Mif 0-50 mg.L-1, alone or combinatively, for 24 h. LD50 (mg.L-1) were: DL111-IT 18.1 (15.1-21.4), Mif 25.0 (23.1-26.9), DL111-IT 5.0 plus Mif 3.5 (1.8-6.5) or Mif 5.0 plus DL111-IT 4.6 (1.1-7.3), respectively. CONCLUSION: DL111-IT enhanced action of Mif on DC, reduced quantity of PR, so the 2 drugs had the synergistic action in termination of early pregnancy.
We have introduced an inducible wild-type p53 allele into the human SW480 colon cancer cell line, which bears an endogenous mutant p53 allele. The expression of inducible wild-type p53 is under basal repression by the lac repressor and is induced by isopropyl-beta-thiogalactopyranoside. The addition of isopropyl-beta-thiogalactopyranoside induces expression of wild-type p53 transcript and protein at a level no greater than that of the endogenous mutant p53. This level of wild-type p53 induction is sufficient both to induce expression of WAF1/CIP1 and to induce G1 cell cycle arrest. This p53-induced growth arrest is reversible after 6 days of continuous p53 expression, indicating that apoptosis is not induced. These results demonstrate that in a human colon epithelial cell background, wild-type p53 is functionally dominant over this mutant p53 and thus provides a mechanism for the observed inactivation of both copies of the p53 gene in most colon cancers. Moreover, despite the well-documented role of apoptosis in maintaining homeostasis in the nontransformed colon epithelium, these results demonstrate that restoration of wild-type p53 expression is insufficient to trigger apoptosis of transformed colonic cells.
Wild-type p53 is induced by DNA damage. In different cell types, this induction is suggested either to facilitate DNA repair by inducing a cell cycle pause or to potentiate cell death via apoptosis. Wild-type p53 in different cell types has similarly been associated with either enhancement of or increased resistance to the cytotoxicity of many cancer therapeutic agents. We have constructed a colorectal cancer cell line bearing, in addition to endogenous mutant p53 alleles, an exogenous wild-type p53 allele that is under the regulatable control of the lac repressor. Induction of wild-type p53 by isopropyl-beta-thiogalactopyranoside in these cells induces a reversible growth arrest but does not induce cell death. However, we find that the induction of wild-type p53 powerfully potentiates the cytotoxicity of both irradiation and 5-fluorouracil, two agents that are used clinically in the treatment of colorectal cancer. We also find that induction of wild-type p53 potentiates the cytotoxicity of topotecan, a member of the camptothecin family of drugs that also has clinical activity against colon cancer. These findings suggest that the common loss of wild-type p53 in many colorectal cancers may play a role in the clinical resistance of these tumors to anticancer agents. Although some cancer cells may not be directly killed by p53 gene therapy, our findings suggest that genetic alteration of some cancers to induce wild-type p53 may increase their sensitivity to cytotoxic gene therapy.
We have used a "plug and socket" targeting technique to generate a mouse model of beta 0-thalassemia in which both the b1 and b2 adult globin genes have been deleted. Mice homozygous for this deletion (Hbbth-3/Hbbth-3) die perinatally, similar to the most severe form of Cooley anemia in humans. Mice heterozygous for the deletion appear normal, but their hematologic indices show characteristics typical of severe thalassemia, including dramatically decreased hematocrit, hemoglobin, red blood cell counts, mean corpuscular volume, mean corpuscular hemoglobin, and mean corpuscular hemoglobin concentration, as well as dramatically increased reticulocyte counts, serum bilirubin concentrations, and red cell distribution widths. Tissue and organ damage typical of beta-thalassemia, such as bone deformities and splenic enlargement due to increased hematopoiesis, are also seen in the heterozygous animals, as is spontaneous iron overload in the spleen, liver, and kidneys. The mice homozygous for the b1 and b2 deletions should be of great value in developing therapies for the treatment of thalassemias in utero. The heterozygous animals will be useful for studying the pathophysiology of thalassemias and have the potential of generating a model of sickle cell anemia when mated with appropriate transgenic animals.