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Biomedical subjects

L Zhou

Publications and source records attributed to L Zhou.

At least 217 records · Page 12Linked to original sources
PubMed2000

[The analysis of the changes of tongue shape and position, hyoid position in Class II, division 1 malocclusion treated with functional appliances (FR-I)].

OBJECTIVE: The objective of this study is to analyze the changes of tongue shape and position, hyoid position with FR-I therapy in class II, division 1 malocclusion. METHODS: 12 patients with class II, division 1 malocclusion treated with FR-I appliance(8 male, 4 female, average 11 years old) were chosen. The acceptable standard of this experiment was an horizontal growth pattern with normal maxilla, retracted mandible and short lower facial height. The average period of treatment was about 8 months. The assessment was made from a lateral cephalogram taken in habitual occlusion before and after treatment. The shapes and sizes of tongue can be measured from the occlusal films with template. These seven lines from six angles of 30 degrees which can be marked in millimeter. Fig 2 showed the reference points and lines: Is1 (the incisal margin of the lower incisors), Mc (the tip of the distobuccal cusp of the lower fist molar), V(the most caudal point on the shadow of the soft palate or its projection onto the reference line). Is1 connected Mc by a straight line extended to V to form the reference lines. After the lines were constructed, the middle point between Is1 and V was called O, and a perpendicular line was constructed from it to the palate contour. The baseline of the template was coincided with the constructed reference line, and the vertical line intersected the reference line at O. The template was placed over the constructed lines, and the exact measurements of the root, the dorsum and the tip of tongue were taken. This was done along the seven constructed lines, and the measurement gived a relative size of the tongue(e.g. the size related to the oral cavity). RESULTS: After treatment, the shape of tongue changed as a result of the increase of oral cavity. There was a tendency that the position of the tongue shifted forwarded and the tip of tongue lied further forward. At the same time, the position of hyoid moved forward in a horizontal dimension and downward in a vertical dimension. CONCLUSION: It confirms that the therapeutic mechanism of FR-I is to induce an anterior shift of mandible and lead to a forward position of tongue, hyoid and cervical soft tissue, which modify the saggital relationship of jaws. The shape of tongue changes due to the increase of oral cavity.

Child↗
PubMed2000

[Effects of ultrasonography on evaluating the status of cervical lymphatic metastasis in patients with oral squamous cell carcinoma].

OBJECTIVE: To investigate effects of ultrasonography on evaluating the status of cervical lymphatic metastasis in patients with oral squamous cell carcinoma (OSCC). METHODS: Nineteen OSCC patients with the diagnosis confirmed by biopsy of primary focus were included in this study. All the patients were hospitalized in the department of stomatology, Beijing Medical University during June, 1995 and June, 1996, among them there were 13 men and 6 women. The ages were ranged from 31 to 71 years old, with the average of 54.4 years old. The primary focus of 13 cases were in tongue, 3 cases in cheek, 2 cases in gum, and 1 case in the conjunction of gum, mouth floor and tongue respectively. All the patients were examined by ultrasonography prior to operation, and operated with the procedures of excision of primary focus and radical neck dissection. The length, width, Vmax and Vmin and Resistance Index (RI = (Vmax-Vmin)/Vmax) of blood flow of cervical lymphatic nodes were measured with acuson 128 xp/10 color Doppler flow imaging scanner with a 7.5 MHz probe. The total of 34 cervical lymphatic nodes were examined by the scanner. L/W ratios in all nodes, RI and Vmax in 16 nodes were obtained respectively. All results were divided into two groups, metastases and non-metastases groups based on the pathological findings for further statistic analysis. Student t test was employed in the study. RESULTS: The average L/W ratios, the average Vmax and the average RI were 1.95 and 2.17, 0.24 and 0.14, and 0.80 and 0.56 in metastases and non-metastases groups respectively. There was a significant difference between RI in two groups, but no statistical differences were revealed in L/W ratios and Vmax, despite the great difference in the average Vmax in the two groups. When RI > or = 0.65 and Vmax > or = 0.20 m/s were regarded as the criterion for positive diagnosis, the accuracy rate, the sensibility and the specificity was 91.2%, 90%, and 91.7% respectively in making diagnosis of OSCC. CONCLUSION: The status of cervical lymphatic metastases in OSCC patients could be evaluated accurately by the color Doppler flow imaging scanner, which might be helpful in making accurately diagnosis of OSCC, selecting the appropriate operation procedure of neck dissection leading to increased survival ratio and improved quality of life for the patients.

Adult↗
PubMed2000

[The preliminary analysis on the changes of the oral functional space in Class II division 1 malocclusion after triggered by functional appliance].

OBJECTIVE: The purpose of this paper is to study the area changes of the oral functional space in the patients with Angle's Class II division 1 malocclusion after triggered by FR-I functional appliances. METHODS: Twenty patients with Angle's Class II division 1 malocclusion were selected, and the patients were selected by the standards of an horizontal growth pattern with normal maxilla, retracted mandible and short lower facial height. All patients were triggered by FR-I functional appliances and achieved the Angle's Class I occlusion after treatments. The average periods of the treatments were about 9 months. The assessments were made from the lateral cephalograms taken in centric occlusion before and after treatments. The upper and behind borders of the oral functional space are hard palate and soft palate, the forward border is the lingual side of upper and lower incisors, the lower border is the line between apex of lower incisor and lower first molar. The graphics from the lateral cephalogram were painted and input into the computer by scaner, which were measured by special software. Self-controls of individuals before and after treatments were used in statistic analysis. RESULTS: The paired-samples t test confirmed the oral functional space was enlarged after triggered by FR-I functional appliance, which was induced by obviously increased mandibular body and ramus, anterior lower facial height and posterior facial height. At the same time, the angle of Y axis increased and the upper incisor inclined lingually, but the inclining angle of lower incisor was not obvious. CONCLUSION: Enlarged oral functional space facilitates the development of the maxilla, mandible and alveolar bones and consummates the functions of oral and jaw system. This study aids the design and application of FR-I functional appliance.

Adolescent↗
PubMed2000

[The design, functions and clinic applications of lip bumper].

OBJECTIVE: This paper introduced the principle of design, methods of fabrication, indications and functions of lip bumper, and advocated the application of lip bumper in orthodontic clinic. METHODS: Two typical cases treated with lip bumper were introduced. Some notices and experiences of applying lip bumpers were summed up. RESULTS: There were following functions of lip bumper: as a space maintainer, Fränkel effect, headgear effect, post-maxillary expansion retention, derotation of molars, and combined using with headgear. CONCLUSION: The advantages of lip bumper are inclusions of a wide range of indication, wearing for 24 hours per day, easily fabricating and prefabricating, comfortable and hidden for patients.

Child↗
PubMed2000

[The effects of the plasty of the cavity of auricular concha in the post-mastoidectomy].

OBJECTIVE: The purpose of this study was to compare the results of mastoidectomy with the plasty of the cavity of auricular concha and the counterpart of mastoidectomy without it at after for 2-6 years followup. METHOD: A retrospective analysis of 320 cholesteatoma cases, surgically treated at the department of otorhinolaryngology-head and neck surgery, Renji hospital affiliated to Shanghai No. 2 Medical University, over a 9-year period, is reported. RESULT: A satisfactory results from the follow-up implicated that this procedure was important for epithelization of the mastoid cavity and the attaining of dry ear after mastoidectomy. CONCLUSION: The plasty of the cavity of auricular concha has an emphasized role in the post-mastoidectomy and is clinically worthy to be applicated.

Adolescent↗
PubMed2000

[Hemangioendothelioma of larynx].

OBJECTIVE: To study the biological behaviour and treatment of larynx hemangioendothelioma. METHOD: One case of larynx hemangioendothelioma was reported and the relative literatures were reviewed. RESULT: The common symptoms of the disease include hoarseness and larynx obstruction caused by the enlargement of the tumor. The biological behaviour of the larynx hemangioendothelioma is low-grade malignant and recurred, between the benign hemangiomas and malignant angiosarcomas. CONCLUSION: The treatment of the hemangioendotheliomas is enlarged removal of the tumor by Majer-Piquet' operation. Chemotherapy and radiation are not valuable.

Hemangioendothelioma↗
PubMed2000

[Production and some properties of a thermophilic protease from Bacillus stearothermophilus WF146].

The factors affecting Bacillus stearothermophilus WF146 for thermophilic protease producing have been investigated, more than 600 units of enzyme in 1 mL of fermented culture could be achieved under suitable condition. The protease had a molecular weight around 34 kD estimated by SDS-PAGE, and functioned optimally at pH 8.0 and 80 degrees C, respectively. In addition, the enzyme exhibited high temperature tolerance and was stable at a wide range of pH, and Ca2+ played a key role for the stability of the enzyme. While the protease activity of the enzyme was strongly inhibited by PMSF, DFP and IAA, and was not affected by DTT.

Endopeptidases↗
PubMed2000

[Isolation and identification of myxobacteria].

This paper reported that the authors isolated large numbers of myxobacteria from more than 100 samples collected in many places of China. More than 400 pure strains were obtained. These strains belonged to 10 genera of Myxococcales. The most frequent genera isolated were Myxococcus, Sorangium, Corallococcus, and Cystobacter. Melittangium was seldom isolated. No Chondromyces and Haploangium were found.

Cellulose↗
PubMed2000

[A practical compression algorithm of the X ray images].

The application of a lossless compressioin algorithm, based on the R, G, B value of pixel, to a X ray analyzing system is introduced through some medical examples of the X Ray image. The realization of the algorithm is completely presented, based on the design and the description of the characteristics, the R, G, B value of the pixed and the lossless compression methods of the X ray images.

Algorithms↗
PubMed2000

[Effects on fiber regeneration following facial nerve transection treated with NOS antagonist].

OBJECTIVE: To elucidate the role of nitric oxide synthase antagonist, N-Nitro-L-Arginine Methyl Ester (L-NAME) in the regeneration of facial nerve following facial nerve transection. METHOD: The facial nerves of 40 guinea pigs were exposed and a segment of the nerve at 3 mm length were excided. The two ends of the transected nerve were sutured and enveloped in a silicone tubule to form a regeneration chamber. L-NAME and saline were respectively injected into the regeneration chambers just after transection. The experiments were observed quantificational by the means of axon and myelin staining under light microscope. RESULT: The findings in the work indicate that inhibition of NOS with L-NAME substantially better myelinated facial nerve regeneration than that associated with administration of saline. CONCLUSION: L-NAME improve the regeneration of myelinated fibers. The mechanism seems to be related to the blockade of NO's neurotoxicity.

Animals↗
PubMed2000

[Sequence analyzing and genotyping of the gene encoding glutamate rich protein of geographically different Plasmodium falciparum isolates obtained from different malaria endemic areas].

OBJECTIVE: To sequence a gene encoding GLURP and identify the genotypes of geographically different Plasmodium falciparum isolates from Yunnan and Hainan Provinces, China. METHODS: The gene of R2 repeat region of GLURP was amplified by the nested polymerase chain reaction and cloned into T-vector. The nucleotide sequence of the GLURP gene was determined using automatic sequencer (dideoxy chain termination method), and analyzed by DNA Star software. RESULTS: At least 7 different GLURP genotypes ranging from 600 bp to 1,500 bp were found in different P. falciparum isolates from Yunnan and Hainan Provinces. R2 region of GLURP gene consisted of several repeat units, each was composed of 19-20 residues which were shown to be highly conserved. The GLURP gene was also size polymorphic due to differences in the number of repeat units, whereas the repeat sequence was conserved. Sequence analysis showed that DNA sequences and deduced amino acid sequences were highly homologous among the geographically dispersed isolates or various isolates from the same geographical region. No obvious differences were found in the GLURP gene sequences among geographically different isolates. CONCLUSION: The GLURP gene of geographically different P. falciparum isolates is highly conserved and size polymorphic, being useful in searching for malaria vaccine candidate antigen and developing a genotyping method for malaria research.

Amino Acid Sequence↗
PubMed2000

[Analysis of Amomun villosum species and some adulterants of zingiberaceae by RAPD].

Different Amomum villosum Lour. species and some their adulterants of Zingiberaceae were researched using RAPD. The PCR indicates favourable differentiation of the reaction. The Amomum villosum Lour. species have the similar DNA fingerprints while it is obviously differ from adulterants. There are 12.17 percent of primers which appear polymorphism. We can identify different species according to these dissimilarity. We also construct the tree of the molecular evolution through NJ software, the hereditary distance of the graph shows different relationships between Amomum villosum Lour. species and their adulterants. The result created by software is analogous the traditional methods.

Amomum↗
PubMed2000

[Experimental study on decoctum Agrimonia pilosa Ledeb-induced apoptosis in HL-60 cells in vitro].

In this study, MTT assay, cell morphology and flow cytometry were used to explore Agrimonia pilosa Ledeb on HL-60 cells in vitro. The data suggested that Agrimonia pilosa Ledeb had the effects of growth inhibition in HL-60 cells. After treated with decoctum Agrimonia pilosa Ledeb, cells underwent apoptosis with typical morphological feature. DNA histograms by flow cytometric analysis displayed distinct apoptotic peak.

Agrimonia↗
PubMed2000

[Ocular axial length and refractive changes in pediatric pseudophakia].

PURPOSE: To evaluate the ocular axial length and refractive changes that occured in children who had cataract extraction with intraocular lens implantation and to investigate the factors that influenced the pseudophakic refraction. METHODS: A review of 12 eyes in 10 children (mean age 7.16 years, range 3.83 to 10.16 years) who had cataract extraction with intraocular lens implantation was undertaken. Patients were followed for an average of 35.8 months. The preoperative and the last postoperative axial length and corneal curvature (K readings) in both operated and unoperated eyes were measured. The distance from the vertex of the cornea to the anterior vertex of intraocular lens (AVpc) was measured in the final follw-up. The initial (in two weeks) and the last refractive status of pseudophakia were examined. Overall age at surgery averaged 7.16 years (range 3.83 to 10.16 years), with followed up of 35.8 months. RESULTS: In the 12 operated eyes, the mean axial growth was 0.39 mm, whereas in the other eight unoperated eyes it was 0.66 mm. Though the axial length of both eyes increased significantly after surgery (P < 0.05), there was no significant difference in the postoperative increase of axial length between the two groups(P > 0.05). In K readings, there was no significant difference between the operated and unoperated eyes before surgery and in the last follow-up respectively. There was no significant difference between the preoperation and the last follow-up in the operated and the unoperated eyes respectively. The average calculated AVpc (AVpc2) was 4.66 30 mm, but the average objective AVpc (AVpc1) measured with ultrasonic biometry was 3.83 mm. The average difference between them was 0.8320 mm and was significant (P < 0.01). According to SRK formula, using preoperative and the last postoperative axial length and corneal curvature to predict refractive changes, the myopic shift was -1.53 D, but the average objective refractive difference between the last and initial examination after surgery was -3.86 D. The average difference between the predicted and actual postoperative refractive changes was significant (P < 0.05). CONCLUSION: Our study suggests that there may be no effect on ocular growth in children (3 to 10 years) followed cataract extraction and intraocular lens implantation. Increasing of axial length and moving forward of intraocular lens induced by complication may result in myopic shift in pseudophakia of children. Slightly undercorrected eyes with intraocular lens in children after cataract extraction will gradually move to emmetropia or moderate myopia in adulthood.

Adolescent↗
PubMed2000

[The disposing techniques of evoked potentials].

This paper is to bring forward the new disposing techniques of evoked potentials which include four aspect techniques of the averaging, the recording, digital sampling and filters about the averaging, evoked potential amplitude, evoked potential latency, evoked potential recording, and evoked potential generations. The technique of the averaging including signal filtering and a periodic averaging, can enhance EP dedection. The commercial EP machines also plot changes in latency between serial EP studies in order to detect trends in peak latency. The modern digital EP recording device consists of sensory stimator, recording amplifiers with analog filters, an analog-to-digital converter, a digital signal averager, and a display and storage system. A sample-and-hold function is one of the recent developments which used EP collectors that provide simultaneous recording with multiple channels employing different time and voltage scales and sampling rates. The EP data may be further processed following A-D conversion by digital filters.

Electroretinography↗
PubMed2000

[Relationship between tissue inhibitors of metalloproteinase and metastasis and prognosis in breast cancer].

OBJECTIVE: To investigate the clinical significance of tissue inhibitors of metalloproteinase (TIMP) -3 and TIMP-4 in human breast cancer. METHODS: The levels of TIMP-3 and TIMP-4 mRNA in paraffin-embedded breast carcinoma specimens from 70 patients with primary invasive breast cancer who had undergone radical mastectomy from January of 1984 to December of 1985 were assessed by in situ hybridization assay. Intratumoral microvessel density (MVD) and vascular endothelial growth factor (VEGF) expression were detected by the standard streptavidin biotin peroxides method. RESULTS: Both TIMP-3 and TIMP-4 mRNA expressions were higher in patients with axillary lymph node metastasis than in those without metastasis (P < 0.01), and patients with higher expression of any of these two genes had a better prognosis than those with lower expression (P < 0.01). We introduced lymph node status, TNM staging, MVD and VEGF expression, plus TIMP-3 and TIMP-4 to the Cox's proportional hazards regression model for significant analysis, and found that the TIMP-3, TNM staging and MVD play an important role in prognosis of this group. CONCLUSIONS: TIMP-3 and TIMP-4 are correlated with metastasis in breast cancer, and TIMP-3 demonstrates an independent prognostic factor for the patients. These results provide a valuable clue for developing new, practical prognosticators in breast cancer patients.

Breast Neoplasms↗
PubMed1999

Studies on treatment of acute promyelocytic leukemia with arsenic trioxide: remission induction, follow-up, and molecular monitoring in 11 newly diagnosed and 47 relapsed acute promyelocytic leukemia patients.

Fifty-eight acute promyelocytic leukemia (APL) patients (11 newly diagnosed and 47 relapsed) were studied for arsenic trioxide (As2O3) treatment. Clinical complete remission (CR) was obtained in 8 of 11 (72.7%) newly diagnosed cases. However, As2O3 treatment resulted in hepatic toxicity in 7 cases including 2 deaths, in contrast to the mild liver dysfunction in one third of the relapsed patients. Forty of forty-seven (85.1%) relapsed patients achieved CR. Two of three nonresponders showed clonal evolution at relapse, with disappearance of t(15;17) and PML-RARalpha fusion gene in 1 and shift to a dominant AML-1-ETO population in another, suggesting a correlation between PML-RARalpha expression and therapeutic response. In a follow-up of 33 relapsed cases over 7 to 48 months, the estimated disease-free survival (DFS) rates for 1 and 2 years were 63.6% and 41.6%, respectively, and the actual median DFS was 17 months. Patients with white blood cell (WBC) count below 10 x 10(9)/L at relapse had better survival than those with WBC count over 10 x 10(9)/L (P =.038). The duration of As2O3-induced CR was related to postremission therapy, because there was only 2 of 11 relapses in patients treated with As2O3 combined with chemotherapy, compared with 12 of 18 relapses with As2O3 alone (P =.01). Reverse transcription polymerase chain reaction (RT-PCR) analysis in both newly diagnosed and relapsed groups showed long-term use of As2O3 could lead to a molecular remission in some patients. We thus recommend that ATRA be used as first choice for remission induction in newly diagnosed APL cases, whereas As2O3 can be either used as a rescue for relapsed cases or included into multidrug consolidation/maintenance clinical trials.

Adult↗