Biomedical subjects

Z Li

Publications and source records attributed to Z Li.

At least 1,009 records · Page 56Linked to original sources

PubMed1998

[Long-term follow-up study of postoperative revascularization in childhood moyamoya disease: results of 226 cases].

OBJECTIVE: To study the long-term results of 226 patients with moyamoya disease ased below 15 years and to report the modified method of extra-intracranial arterial anastomosis and encephalo-myo-arterio-syn-anastomosis, etc. METHOD: The mean follow-up period was 15.5 years (range 8 - 19 years). The results were obtained from the pre- and postoperative cerebral angiographic examination, MRI, CT, cerebrovascular Doppler ultrasonography, Glasgow Outcome Scale (GOS), intelligence quotient (IQ) as classified by Taft and neurological symptoms. RESULT: Of the 226 patients with childhood moyamoya disease, 64 (28%) recovered in completely, 69 (31%) in improved markedly, and 46 (20%) improved slightly. 43 patients (19%) had no changes and 4 (2%) died. The effective rate of the operation was 79%. CONCLUSION: The modified direct anastomosis and encephalo-myo-arterio-synagiosis played a role in this improvement by increasing CBF after the operation. A significant correlation is found between the postoperative effect and the stages of preoperative angiograms.

Adolescent↗

PubMed1998

[Surgical treatment of infective endocarditis].

OBJECTIVE: To summarize the experience of surgical treatment of infective endocarditis in 28 patients. METHOD: Open heart surgery under cardiopulmonary bypass was performed in all patients: valve replacement (24), VSD repair and tricuspid annuloplasty (3), and Bentall (1) 17 mechanical and 7 homograft valves were placed. RESULT: Two died in hospital, 4 died from infection, 1 had periprosthetic leakage and incompetence respectively. 22 survivors showed improved heart function. CONCLUSION: Combined medication and surgical treatment is superior to antibiotic treatment in long-term survival and convalescence. Infective reccurrence, reinfection and advanced heart failure are major risk factors after operation.

Adolescent↗

PubMed1998

[Corneal topographic analysis after excimer laser photorefractive keratectomy].

OBJECTIVE: To analyze the changes in corneal topography after excimer laser photorefractive keratectomy (PRK). METHODS: The topographic changes of 122 eyes (62 patients) and 96 eyes (49 patients) on which PRK was performed were reviewed after 3 and 6 months of follow-up respectively. RESULTS: The central island pattern had a relationship with the loss of best corrected visual acuity of more than one line in early postoperative period. On subsequent follow-up, the central island pattern tended to become to other patterns (semicircular, keyhole and uniform) and the central corneal power decreased, allowing the visual acuity to improve gradually. The simulated K (Sim K) regression index was a useful indication of the changes in the corneal stroma. Sim K was related to the degree of refractive error. The greater the refractive error, the lower the Sim K. CONCLUSION: Corneal topography is a useful tool in the analysis of corneal changes in PRK.

Corneal Topography↗

PubMed1998

[Rotated-chipping phacoemulsification in front of capsule].

OBJECTIVE: The study was designed to investigate the clinical effects of rotated-chipping phacoemulsification in front of capsule. METHODS: Phacoemulsification using rotated-chipping technique in front of capsule with intraocular lens implantation was performed with medium energy and high vacuum on 50 eyes. RESULTS: Rotated-chipping technique was successfully completed in 46 of 50 eyes (92%), unsuccessful cases were related to shallow anterior chamber and incomplete hydrodissection. CONCLUSION: These results suggest that rotated-chipping phacoemulsification be used for cataracts with various sclerotic nuclei and it is valuable to be applied extensively.

Aged↗

PubMed1998

[An ultrasound biomicroscopic study on changes of the structure of ocular anterior segment after topical application of cycloplegia].

OBJECTIVE: To observe the changes of ocular anterior segment and the relation between the intraocular pressure (IOP) and these changes after the topical application of cycloplegia using ultrasound biomicroscope (UBM), especially to observe the changes of ciliary body thickness and ciliary body-lens distance. METHODS: The quantitative measurement of UBM and the measurement of IOP had been done in 48 normal eyes before and after the topical use of 2% homatropine solution. The results were statistically analyzed. RESULTS: In the parameter reflecting the change of the anterior chamber angle after using 2% homatropine, the trabecular iris angle decreased, the angle open distance 250 decreased, the iris thickness 1 increased, the anterior chamber became deeper and the iris-lens contact distance became shorter, and all these differences were statistically significant (P < 0.05). In the parameter reflecting the changes of ciliary body, the ciliary body thickness and the ciliary process thickness decreased, the scleral ciliary body angle increased, the iris-zonule distance decreased and the ciliary body-lens distance increased, and all these differences were significant statistically (P < 0.05). The IOP increased from 2.35 +/- 0.46 kPa to 2.43 +/- 0.47 kPa after the topical use of 2% homatropine, but the differences were not statistically significant (P > 0.05). CONCLUSIONS: After the topical application of cycloplegia, the anterior chamber becomes deeper, the anterior chamber angle becomes narrower, the ciliary body becomes thinner and moves backward and the ciliary body-lens distance increases. By using UBM the structure of ocular anterior segment in its moving state can be observed and these structures can be measured quantitatively. The ultrasound biomicroscopic imaging has its advantages in the morphological study of ocular anterior segment.

Adult↗

PubMed1998

[Studies of mechanism of malignant glaucoma using ultrasound biomicroscope].

OBJECTIVE: To study the mechanism of malignant glaucoma using ultrasound biomicroscope (UBM) combined with general A scan and to observe the conditions of cilio-lens block in living eyes at the realtime when malignant glaucoma is occurring. METHODS: 31 eyes from 27 patients with malignant glaucoma were evaluated and 54 normal eyes and 72 eyes of primary angle-closure glaucoma were studied as the controls. RESULTS: Of the 31 eyes, close attachments between the ciliary body and the lens were found in 18 eyes (58.1%) and slits between them were found in 13 eyes (41.9%) during the onset of malignant glaucoma. Ciliary body thickness increased significantly (P < 0.05). Fluid in the supraciliary space was found in 11 eyes. CONCLUSIONS: The mechanism of malignant glaucoma is associated with the abnormal relationship among anterior vitreous, ciliary process and lens periphery. Fluid in the supraciliary space makes the ciliary process closer to the lens periphery. It is one of the factors causing cilio-lens block. The ultrasound biomicroscopic image is a new better practicable method to diagnose malignant glaucoma during its onset compared with other methods at present used in the clinical work. It is much more valuable to differentiate the pupillary block glaucoma from malignant glaucoma by using ultrasound biomicroscopy.

Adult↗

PubMed1998

[A study on lens epithelial cell ultrastructure in rhesus monkey cataract].

OBJECTIVE: To investigate the ultrastructure of lens epithelial cells of normal eyes and cataractous eyes in rhesus monkeys. METHODS: Anterior capsules were taken from 4 normal lenses and 4 cataractous lenses of rhesus monkey eyes, and the samples were observed under transmission electron microscope. RESULTS: The ultrastructure of the cataractous lens epithelial cells changed obviously. Mitochondria with disappearance of crista were swollen, and vacuolar. Hollow cell with a single large vacuole in the cytoplasm could be seen. The cytoplasm presented dissolution. Cells were swollen and damaged, even cell membrane disruption could be seen. Karyopyknosis, nuclear deformity, disappearance of perinuclear cistern and nuclear pores could be found. The heterochromatin was concentrated and aggregated at the nuclear periphery. CONCLUSIONS: The ultrastructural changes of the lens epithelial cells in monkey cataractous lens are similar to that in human cataractous lens. Rhesus monkey cataract may be a suitable experimental model to investigate the formation of human cataract.

Animals↗

PubMed1998

[Studies of mechanism of primary angle closure glaucoma using ultrasound biomicroscope].

OBJECTIVE: To investigate the mechanism of primary angle closure glaucoma (PACG) especially the role of the changes of ciliary body using ultrasound biomicroscope (UBM) combined with general A scan. METHOD: 99 eyes with PACG, including 50 eyes with acute and 49 eyes with chronic PACG, were evaluated and 58 normal eyes were in the control group. RESULTS: Compared with the normal eyes the PACG eyes had their anatomic features. They had a smaller corneal diameter, shorter axial length, shallower anterior chamber, thicker lens, more relative anterior location of lens, swelling of ciliary process and anterior rotation of ciliary body. All these differences were significant statistically (P < 0.05). Compared with the chronic PACG eyes the acute PACG eyes had a shallower anterior chamber and a more anteriorly situated lens position. The differences were significant statistically (P < 0.01). Compared with the normal eyes the acute PACG eyes had a shorter ciliary body - lens distance and the difference was significant (P < 0.05); the chronic PACG eyes also had a shorter ciliary body-lens distance, but the difference was not significant (P > 0.05). CONCLUSIONS: The PACG eyes have their anatomic features. Among these factors the pupillary block caused by the anterior displacement of lens and the narrow angle induced consequently are the common mechanism. The swelling ciliary process, the positional changes of the ciliary body and age-related thicker lens are possibly the initial causes causing the forward movement of lens, and the pupillary block plays a more important role in the pathogenesis of acute PACG.

Adult↗

PubMed1998

[Reconstructive lacrimal gland with free submandibular gland transfer for management of xerophthalmia].

OBJECTIVE: In order to seek more efficient surgical method to treat total xerophthalmia. METHOD: Microvascular submandibular gland transfer was used to reconstruct lacrimal gland for management of the dry eye. 5 cases (6 eyes) with total xerophthalmia were operated with this method. RESULTS: All the patients were followed up for 1 - 30 months. The results were satisfactory, the submandibular salivary gland relieved the dryness and improved visual acuities with negligible side effect. CONCLUSION: Microvascular submandibular gland transfer is potentially the best surgical solution to total xerophthalmia.

Adolescent↗

PubMed1998

[A research on clinical values of corneal topography and keratometer in measuring astigmatism].

OBJECTIVE: To compare the accuracy of corneal topography, keratometer and cycloplegic retinoscopy in measuring astigmatism for refractive surgery. METHODS: Three hundred and sixty eyes with ametropia were randomly selected. The results of corneal topography, that of keratometer and cycloplegic retinoscopy in measuring astigmatism before refractive surgery were compared, and the measuring results of corneal topography and that of keratometer for 72 eyes after photorefractive keratectomy (PRK) and 95 eyes after laser in situ keratomileusis (LASIK) were also compared. RESULTS: No significant difference was found in axes of astigmatism among the three groups. As for diopters of astigmatism, there was no significant difference between the group of corneal topography (DeltaSim K) and the group of keratometer (DeltaK), but we found significant difference between the group of cycloplegic retinoscopy and the other two groups before and after refractive surgery. Significant difference was also found between DeltaSimK and DeltaK after PRK and LASIK. CONCLUSIONS: Our investigation demonstrates that before refractive surgery the keratometer has a similar clinical value as that of corneal topography, and the DeltaSim K value is related to the graphic pattern of corneal topography. However, keratometer is limited in measuring mild changes in corneal curvature after refractive surgery, while the astigmatism expressed by DeltaSim K in corneal topography is more accurate.

Adolescent↗

PubMed1998

[Research and development of the surface EMG detection and analysis system].

To meet the requirement of developing myoelectric controller for a man-machine systems, a surface electromyography (EMG) detection and analysis system is discussed in this paper. This system consists of two parts--data acquisition hardware and signal processing software. In the surface EMG acquisition system both wire and wireless TELEMG are available. In the surface EMG processing system various methods are integrated such as the methods in time domain, the methods for frequency analysis, and also including some newly developed methods, e.g., wavelet transform and fractal analysis. This system provides a useful platform for research and development of the myoelectric controller that is widely used in rehabilitation engineering products.

Electromyography↗

PubMed1998

[Triterpenes and steroidal compounds from Momordica dioica].

Three triterpenes and two steroidal compounds were isolated from the dry root of Momordica dioica. Their structures were elucidated by spectral analyses (MS, IR, 1HNMR, 13CNMR and DEPT) and chemical methods. These compounds are alpha-spinasterol octadecanonate(I), alpha-spinasterol-3-O-beta-D-glucopyranoside(II), 3-O-beta-D-glucuronopyranosyl gypsogenin(III), 3-O-beta-D-glucopyranosyl gypsogenin(IV) and 3-O-beta-D-glucopyranosyl hederagenin(V). Constituent III is a new compound. The CHCl3 extract of Momordica dioica roots and five isolated constituents showed anticancer activity in pharmacologic testing on cancer cell(L1210). The growth inhibitory index(%) of compound II was shown to be 50%, at the dose of 4 micrograms.ml-1.

Animals↗

PubMed1998

[SurveilLance on filariasis after its basic elimination in Hunan Province].

AIM: To explore the fluctuation pattern of prevalence and to detect the residual infection in Hunan Province where filariasis had been basically eliminated since 1986. METHODS: Longitudinal surveillance and cross-sectional surveillance were extensively carried out by using parasitological, entomological and serological methods in areas previously endemic for filariasis. RESULTS: In 55 counties, cross-sectional surveillance on filariasis had been executed for 11-19 years. The results showed that microfilaria cases had not been found for 4 years, and filaria larvae had failed to be detected from mosquito vectors for 12 years. Serological surveillance in the population revealed that the mean positive rate of IFAT had dropped from 13.15% in 1987 to 1.06% in 1996, the latter rate being similar to that of the nonendemic area. 6 longitudinal surveillance spots in 5 counties (cities) had been observed for 10-17 years. Annual quantitative blood examination of 11 microfilariemia cases showed that 10 cases became negative in 1-10 years, and the remaining 1 case remained positive at the 14th year. A. sinensis were dissected with no filaria larvae found in 2 surveillance spots of malayan filariasis. Culex quinquefasciatus were dissected with filaria larvae found only in the first to third year, the natural infection rates were 0.38%-1.98% in 4 surveillance spots of bancroftian filariasis. CONCLUSION: Since the basic elimination of filariasis in Hunan Province in 1986, the number of residual microfilariemia cases decreased year after year, suggesting that the transmission of filariasis has been interrupted.

Animals↗

PubMed1998

[Relationship between root rot on Panax notoginseng Burk. F. H. Chen and its environmental conditions].

OBJECTIVE: To probe into the relationship between root rot on Panax notoginseng and its environmental conditions for integrate control of the disease. METHOD: Field observation and analysis on the planting plots were conducted regularly. RESULTS: Root rot on P. notoginseng occurs extensively in Wenshan Prefecture, with two peaks of incidence per year. The first peak appears in March-April; and the second July-August. Air temperatures around 20 degrees C and relative humidities of higher than 95% are favorable for the disease to occur and spread. The root rot is severe when the light transmitting rate in the shade shed is too high(> 30%). The disease is severer in land of continuous cropping than in land of rotational cropping and land of new cropping. The severity of the rot increases with the years of continuous cropping. The art of field management also influences the occurring and spreading of the disease. CONCLUSION: The occurring and spreading of P. notoginseng root rot are closely related to its environmental conditions.

Drugs, Chinese Herbal↗

PubMed1998

[Study on immobilized cells for producing alpha-amylase by using polyving alcohol as the carrier(II): The effect of fermentating conditions on the ability producing alpha-amylase of the cells immobilized with polyving alcohol as the corrier and continuous fermentation of the immobilized cells in CSTR].

The effects of fermentating conditions on the ability of immobilized cells with PVA as carrier for producing alpha-amylase were studied. The continuous fermentation with the immobilized cells were tested in continuous flow stirred tank reactor (CSTR). The results showed that the adaptability of the immobilized Bacillus substilis to pH increased after immobilization. In CSTR, the immobilized cells can be fermentated continuously for 360 hrs and the activity of alpha-amylase can be kept on the level of about 170 u/ml.

Bacillus↗

PubMed1998

[Studies on microbial factor on color change of Dunhuang mural. I. Classification of microbes on color-changed mural and property of some typical species].

Microbial strains were isolated from 51 typical color changed samples of mural in 6 grottos of Dunhuang Mogao Gretto. After identification, it is proved that belong to 6 genera of bacteria and 5 genera of mould. Bacillus, Alcaligenes and Penicillium were dominant species in all of them. In the imitative experiment, it is found that Cladosporium sp., A. niger and two strains of bacteria have a great effect on the color change of red pigment of mural and aging of sizing agent.

Bacteria↗

PubMed1998

[Studies on control of root rot on Panax notoginseng].

Chemical Control tests of pot, plot and field for Panax notoginseng root rot were conducted during 1995-1996. The results indicated that the chemical control is a effect measure to control rapidly occurring and spreading of Panax notoginseng root rot. It was the best treatment to coordinate use of bactericide and fungicide, obviously better than alone or mixed use of fungicide and also better than alone use of bactericide. In the pot and plot tests, the best coordinate treatment was the treatment of 10% phenazine plus 70% dexon plus 50% bavistin and plus water (1:1:500), the control effect was 70%; in the field test, the control effect of over 70% was also get with the treatment of 10% phenazine plus 70% dexon and plus small soil (1 Kg:1 Kg:150 Kg) per mu.

Benzenesulfonates↗

PubMed1998

[The immune activity of polysacharide of chuanniuxi].

It reported the immune activity of polysacharide of Chuanniuxi to mouce's RES, PFC, lymphocyte transformation and NK Cell. The results show that the polysacharide can improve the activity of RES, PFC and NK Cell, but can't increace the lymphocgte stimulation index.

Amaranthaceae↗