Biomedical subjects
Publications and source records attributed to Y Xu.
From Pyrrosia gralla four compounds were isolated and identified stigmasterol(I), ursolic acid (II), mangiferin(III) and sucrose(IV) by physical and chemical means. Compounds I and II were obtained from Pyrrosia for the first time.
OBJECTIVE: To patlern the clinical ruptures of injured arteries. METHODS: Traumatic methods and microsurgery were employed. RESULTS: Experimental model of pseudoaneurysm was made in 72 femoral arteries of 54 Japanese white rabbits, with a successful rate of 95.8%. Using these models, the process and the mechanism for the formation of pseudoaneurysm were studied. The effects of color Doppler's ultrasonic image, CT, MRI and arterial angiography in the diagnosis of pseudoaneurysm were evaluated. CONCLUSION: The indicators for clinical signs of the rupture hemorrhage of pseudoaneurysm were put forward. The methods for balloon dilation to block the blood supply of the carrier artery and control the hemorrhage of operation were set up.
OBJECTIVE: To evaluate the value of the preoperative T staging of laryngeal cancer by MRI. METHODS: The MRI data of 59 cases of laryngeal cancer were retrospectively staged, and compared with the findings of laryngoscopy and postsurgical pathologic staging. RESULTS: The accuracy of staging in each T stage of laryngeal cancer was: T1:95% (20/21), T2:88% (15/17), T3:85% (11/13) T4:100% (8/8) by MRI, vs T1:91% (19/21), T2:88% (15/17), T3:47% (8/13), T4:13% (1/8) by laryngoscopy. The total accuracy of MRI vs laryngoscopy was 92% (54/59) vs 73%(43/59). P < 0.01. CONCLUSION: MRI can correctly depict the invasion of the preepiglottic space (PES), paraglottic space (PGS) and cartilage by laryngeal cancer and can greatly improve the accuracy of preoperative staging. It was considered that MRI of great importance in determining appropriate therapy for laryngeal cancer.
OBJECTIVE: To investigate the biomechanical aspects of etiology, pathology, clinical manifestation, diagnosis and surgical treatment of the lumbar spinal stenosis. METHODS: A series of biomechanical methods, such as three-dimensional finite element models, three-dimensional kinematic measurement, cadeveric evaluation, and imaging assessment was applied to correlate lumbar biomechanics and lumbar spinal stenosis. Surgery of lumbar spinal stenosis has been improved. RESULTS: The stresses significantly concentrate on the posterolateral part of the annulus fibrosus of disc, the posterior surface of vertebral body, the pedicle, the interarticularis and the facet joints. This trend is intensified by disc degeneration and lumbar backward extension. Posterior element resection has a definite effect upon the biomechanical behavior of lumbar vertebrae. The improved operations proved satisfactory. CONCLUSION: Stress concentration in the lumbar vertebrae is of importance to the etiology of degenerative lumbar spinal stenosis, and disc degeneration is the initial key of this process. Then these will be aggravated by backward extension. Functional radiography and myelography are of assistance to the diagnosis of the lumbar spinal stenosis. For the surgical treatment of the lumbar spinal stenosis, destruction of the posterior element should be avoid as far as possible based upon the thorough decompression. Maintaining the lumbar spine in flexion by fusion after decompression has been proved a useful method. When developmental spinal stenosis is combined with disc herniation, discectomy through laminotomy is recommend for decompression.
OBJECTIVE: To evaluate the effect of dietary fiber on intestinal structure and barrier function of 5-fluorouracil (5-Fu) challenged rat. METHOD: Thirty Wistar rats were divided randomly into three groups (10 each group): Chow, enteric nutrition (EN), and EN + Fiber group. Both EN and EN + Fiber group were isonitrogenic and isocaloric. The rats kept their diet respectively for 8 days. 5-Fu was injected intraperitoneally on day 4 postoperatively. Intestinal permeability (L/M) was measured respectively on day 3 and day 7. On day 8, the bacterial translation, wet weight and mucous thickness of both small intestine and colon and the villus height of small intestine were measured. The rats were weighted before and after experiment respectively. RESULT: The body weight loss of the EN + Fiber group (-3.1 +/- 3.4 g) was less than that of the EN group (-6.6 +/- 5.2 g) (P < 0.05), whereas the Chow group gained body weight (4.9 +/- 4.3 g) (P < 0.01 when compared with EN and EN + Fiber group). The parameters of intestinal structures of the EN + Fiber group was superior to the EN group (P < 0.05). The L/M of both EN + Fiber (from 0.0265 +/- 0.0073 to 0.0274 +/- 0.0068) and the Chow group (from 0.0268 +/- 0.0039 to 0.0281 +/- 0.0044) was unchanged (P > 0.05 for both) after 5-Fu challenged, whereas that of the EN group increased (from 0.0289 +/- 0.0070 to 0.0331 +/- 0.0084) (P < 0.01). The incidence of bacterial translocation to MLN of both EN + Fiber group and the Chow group (20%) was lower than that of the EN group (70%) (P < 0.05). CONCLUSION: The dietary fiber protects the intestinal structure and barrier function of 5-Fu challenged rats.
OBJECTIVE: To investigate ocular toxic effect of azone at low concentrations in rabbits to determine whether this penetration enhancer has any value for ocular use. METHODS: 0.3%, 0.6%, 0.9% concentrations of azone in an ocular emulsion vehicle were studied. Rabbits in three experimental groups received topical 30 microl of 0.3%, 0.6%, 0.9% azone respectively three times daily for 4 weeks. Rabbits in control group 1 received 30 microl of vehicle without azone as negative control and rabbits in control group 2 received nothing as normal control. Clinical and histopathological examinations of rabbit cornea endothelial cells were made by slit-lamp biomicroscopy, light microscopy and scanning electron microscopy. RESULTS: No clinical and histopathological evidence of ocular toxicity occurred in all treated and control eyes. The concentration of azone used in this study was 3-9 times higher than that (at 0.1%) at which corneal penetration of hydrophilic compounds can be enhanced enormously. CONCLUSION: Azone has value for incorporation into ocular formulations to increase therapeutic action of many hydrophilic drugs.
OBJECTIVE: Homoharringtonine (HHT), a Chinese herbal drug, was used in the form of liposome or solution as an adjunct to glaucoma filtration surgery in rabbits to determine its effect in preventing closure of sclerostomy. METHODS: Forty rabbits that underwent a standard posterior-lip sclerectomy in both eyes were divided into 5 post-operative groups. Group 1 received subconjunctival HHT liposomes (0.025%). Group 2 received subconjunctival blank liposomes and served as control. Group 3 and 5 received subconjunctival HHT solution at low (0.025%) and high (0.1%) doses respectively. Group 4 received subconjunctival normal saline and served as control. Intraocular pressure, interval between operation and bleb failure, rate of scleral fistula occlusion and ocular toxicity were determined in each group. RESULTS: Subconjunctival treatment with HHT solution at a high dose transiently prolongs the survival of filtration surgery, but the subconjunctival use with HHT liposomes or HHT solution at a low dose does not significantly prolong the survival of filtration surgery in rabbits. Significant corneal haze and corneal neovascularization resulted from using HHT at a high dose. CONCLUSIONS: The success rate of rabbit filtration surgery can not be markedly increased by the postoperative use of HHT liposomes or its low dose solution. When the high dosage of HHT solution is used, transient elevation of the success rate can be obtained, however the side-effect is also significantly increased.
Bis-trichloromethyl sulfone(BTS) given p.o. to male Sprague-Dawley rats at a dose of 10 mg.kg-1.d-1, 6 days a week for 8 weeks(or 30 mg.kg-1.d-1 for 4 weeks), was found to lead to infertility. The density and, in particular, the motility of the spermatozoa in the cauda epididymidis were significantly lower than those of the controls (P < 0.001). The body weight, the sex behavior, the blood testosterone level and the histology of important organs were not significantly different from those of the control rats. Fertility started to recover 4 weeks after cessation of medication and was entirely recovered 2 more weeks later in rats having received BTS for 8 weeks at the dose of 30 mg.kg-1.d-1. In vitro study showed that BTS at a concentration of 0.31 mg.ml-1 would make rat spermatozoa immobile within 20 seconds. These results indicate that BTS has both antifertility effect in male rats and direct inhibitory effect on rat spermatozoa. We conclude that nontoxic doses of BTS can induce reversible infertility in male rats.
Three new compounds were isolated from the aerial part of Epimedium koreanum Nakai. On the basis of spectroscopic and chemical evidences, they were elucidated as 3-O-beta-D-glucopyranosyl(1-->3)-alpha-L-(4-acetyl) rhamnopyranoside-anhydroicaritin-7-O-beta-D-glucopyranoside, 2-(p-hydroxyphenoxy)-5, 7-dihydroxy-6-prenylchromone, and 7-hydroxy-3, 4, 6-trimethoxy-9, 10-dihydrophenanthrene-2-O-beta-D-glucopyranoside.
A systematic determination method for 10 drugs of abuse, morphine, codeine, 6-monoacetylmorphine, heroin, levorphanol, pethidine, ethylmorphine, anadol, pentazocine and ethamivan, using high performance liquid chromatography is described. Separation of the 10 drugs was achieved on a 25 cm x 4.6 mm ID, 10 microns Zorbax C8 column, using methanol--0.05 mol.L-1 KH2PO4--diethyl amine (27:73:0.5, pH 4) as mobile phase. Codeine was used as the interal standard. Calibration graphs were linear over the concentration range of 10-200 micrograms.ml-1 and regression equations showed correlation coefficients of greater than 0.999. Precision (RSD) were found to be better than 3% for each compound. Precision and linearity of the method are satisfactory for clinical toxicological applications. The extraction procedure yielded cleaner extracts. The recovery rates from urine were all above 87% without interference. This method is rapid, sensitive and specific.
Two adult rhesus monkeys were chosen for the experimental study of maxillary expansion with magnetic force. The duration of experiment was 70 days. The following methods were applied: 1. measuring the width between the two canines and the width between the two first molars on the casts, 2. taking occlusal radiographs for the observation of premaxillary and midpalatal sutures. 3. observing the histological sections under the microscope. The results showed the width of 3 to 3 and the width of 6 to 6 significantly increased, associating with the adaptation of periodontal tissues to the action of magnetic force.
This paper reported the morphological and histological characteristics of Diequiao Shihu(the crude drug of Dendrobium denneanum Kerr), with linedrawings, and compared the TLC diagram with Jichai Shihu (the crude drug of Dendrobium nobile Lindl.).
In this paper, the chromosome number, karyotype and chromosome volume of Iris lactea ssp. chinensis were reported. The normal diploid was 2n = 32. Karyotype formula was based on Levan's publication in 1964, k (2n) = 32 = 22 m + 8 sm + 2T. According to the method of Kuo SR, the species chromosome based on the relative length was 2n = 32 = 6L + 4 M2 + 18 M1 + 4 S which belong to "2A" type according to the Stebbins' karyotype classification. The AS.K% was 62.5% from Arano's method. The total volume of chromosome groups was 34.95 micron 3.
Pearl and nacre of mollusk shell (Hyriopsis cumingii) were studied with high resolution Fourier transformation infrared spectroscopy (FTIR) and X-ray diffraction (XRD). The results of X-ray diffraction indicate that the samples are still aragonite after thermal treatment at 160 degrees C for 5hr, however, the significant variations of peak position and band width of FTIR spectra reveal the interaction between organic matrix and inorganic crystal in biomineralized materials. The variations of spectra were studied by a curve-fitting algorithm and the band related to the interaction is revealed.
The characteristic infrared spectra of alpha,alpha'-dioxoketene cyclic N,N-acetals have been studied and the changing rules with the change of chemical structure have been discussed.
In this paper, the ultraviolet spectra of alpha,alpha'-dioxoketene cyclic S,S-acetals (N,N-acetals) have been studied and their changing characters with the change of chemical structure have been indicated.
Series of cancer tissues and corresponding normal tissues of gastrointestinal tract (stomach, colon, esophagus) were studied by FTIR technique and the results showed the analogy of the spectra for the cancer tissues, while the spectra of normal tissues can be classified into three kinds. The secondary structures of protein were obtained by using deconvolution and curve-fitting techniques with Amide I bands and the results showed that the contents of alpha -helix and beta-sheet are different between the normal and cancer tissues.
Actinonin, an antibiotic and CD13/aminopeptidase N (APN) inhibitor, has been shown to be cytotoxic to tumor cell lines in vitro. We investigated the antiproliferative effects of actinonin on human and murine leukemia and lymphoma cells. Actinonin inhibited growth of NB4 and HL60 human cell lines and AKR mouse leukemia cells in vitro with an IC50 of about 2-5 micrograms/ml. The inhibitory effect on CD13-positive cells was not blocked by pretreatment with the anti-CD13/APN monoclonal antibody F23, which binds with high affinity to the active site of CD13/APN and blocks its enzymatic activity. Moreover, F23 alone was not inhibitory to CD13-positive cells. Furthermore, a similar inhibitory IC50 of actinonin was seen in the CD13-negative cell lines RAJI and DAUDI human lymphoma. These data suggest that the inhibitory effect of actinonin is not mediated by inhibition of CD13/APN. Cell cycle analysis showed that actinonin induces a G1 arrest in HL60 and NB4 cells; apoptosis was observed in 20-35% of the cells as measured by intracellular flow cytometry. To assess whether these effects could be seen in vivo, the effect of actinonin on the syngeneic AKR mouse leukemia model was evaluated. Actinonin showed dose-dependent antitumor effects on AKR leukemia in vivo, resulting in a survival advantage. In conclusion, apoptosis, growth inhibition, and therapeutic effects in vivo are induced by actinonin and are not likely to be mediated by CD13/APN.