Biomedical subjects

S Zhou

Publications and source records attributed to S Zhou.

At least 127 records · Page 7Linked to original sources

PubMed2001

[X-ray changes of temporomandibular joints after indirect trauma].

OBJECTIVE: The aim of this study is to investigate the structural changes of goat's temporomandibular joints (TMJs) after indirect trauma. METHODS: The trauma to the goat's TMJ achieved under an impact to the right and left mandibular angles using a self-made device. These goats were killed after 2 hours, 7 days, 1 month and 3 months. The goat's TMJs were examined using tomography before being killed, and also checked by using a histological method. The normal temporomandibular joints were treated as the control. RESULTS: 1. The X-ray tomograms: In the early post-trauma stage, the articular cavities were dimmed, and the joint spaces were decreased; the articular surfaces were not smooth, and the structures of TMJ were not clean. Moreover, the stations of the condyle were moved from middle of the fossa to the posterior fossa in the later stage. 2. The histological examination: The condyles exhibited eroded surfaces with osteophytes, the discs were thinned or perforated, and the temporal surfaces were thick-end and the linings were separated. CONCLUSION: The indirect trauma on TMJs of goats can cause the TMJ internal derangement and the osteoarthrosis of TMJs. The X-ray tomography is a very useful method in the long-term monitoring of bone changes in TMJs after trauma.

Animals↗

PubMed2001

[MRI manifestation of temporomandibular joints after indirect trauma].

OBJECTIVE: The objective of this study is to investigate the structure changes in temporomandibular joints (TMJs) of goats after indirect trauma. METHODS: The trauma of TMJs of goats achieved under an impact to the right and left mandibular angles with a self-made device. These goats were killed after 2 hours, 7 days, 1 month and 3 months. The TMJs of goats were examined using MRI before killed and checked by histological method, the normal temporomandibular joints were treated as the control. RESULTS: The results of MRI: in the early post-trauma stage, the condylar articular surface was partially lost, and the discs were displaced and ruptured. Further, the hemathrosis of the TMJ and the decreased joint spaces were also observed in the eroded, eburnous surface of the condyle and the deformed disc. In the later stage, the surfaces of condyles were eroded and eburnated, and the discs were deformed. CONCLUSION: The indirect trauma on the TMJs of goats can cause TMJ internal derangement and TMJ osteroarthrosis. MRI cab be used to investigate both hard and soft tissue injuries of the temporomandibular joint, and is appreciated in understanding the pathogenesis of indirect trauma on the TMJ.

Animals↗

PubMed2001

[Study on maxillofacial impact injury associated with brain injury].

OBJECTIVE: The purpose was to study the mechanism and the characteristics of brain damage associated with maxillofacial injury under the impacting load of middle face. METHODS: Eighteen rabbits were subjected to impacting on left middle face with pneumatic impact device, which were horizontally located on the ground. The impact velocities respectively were 4.77 m/s +/- 0.53 m/s (group A), 9.16 m/s +/- 0.65 m/s (group B) and 13.95 m/s +/- 0.67 m/s (group C). The acceleration of head and stress of encephalic was monitored during the impact period. The pathological characteristics of correlative tissues were examined in detail 6 hours after impacting. The contents of LPO, SOD and NO in blood and water in brain were measured at the same time. RESULTS: The contents of LPO and SOD in blood significantly increased along with the increasing of impact velocity (P < 0.05). The same pattern was observed in the changing of water content of brain (P < 0.05). But the contents of NO in blood reduced when the impact velocity increased (P < 0.05). The animals of group A showed single fracture of middle face bone, while Group B showed multiple fractures of middle face bone. Group C represented severe maxillofacial injury associated with brain damage. The pathological damage of brain became more serious along with the increase of impact velocity. The peak value of head acceleration and encephalic stress of group C were higher than that of group A and group B (P < 0.05). CONCLUSION: The responses of head acceleration and encephalic stress resulting from middle face impacting might play a key role in brain injury associated with maxillofacial injury.

Animals↗

PubMed2001

[Application of video laryngoscope in diagnosis and treatment of laryngeal diseases].

OBJECTIVE: To investigate the value of video laryngoscope in diagnosis of laryngeal diseases. To study the effect of video laryngoscope in treatment of laryngeal diseases. METHOD: Pentax VNL-1530T and Olympus BF-240T video laryngoscope were used in diagnosis of 3628 cases of laryngeal diseases and in treatment of 1221 cases of laryngeal diseases. RESULT: 3628 cases were examined by video laryngoscope, and correct diagnosis was made. 768 cases of vocal cord polyp and 249 cases of vocal cord node were excised, 113 cases of foreign bodies in hypopharynx or larynx were removed. 91 cases of other laryngeal diseases were treated under video laryngoscope. CONCLUSION: Video laryngoscope is a new excellent instrument in diagnosis and treatment of laryngeal disease.

Adolescent↗

PubMed2001

[Superoxide dismutase and cytokines in otitis media with effusion].

OBJECTIVE: To study the role of superoxide dismutase (SOD) and cytokines in the pathogenesis of secretory otitis media(SOM). METHOD: The content of SOD, interleukin-6(IL-6), interleukin-8(IL-8) and tumor necrosis factor alpha (TNF-alpha) in blood plasma and middle ear effusion (MEE) were measured in 64 (90 ears) patients respectively. RESULT: SOD, IL-6, IL-8 and TNF-alpha were found in 88.9%, 86.8%, 81.5% and 74.6% of MEI respectively. SOD, IL-6, IL-8 and TNF-alpha of blood plasma in SOM group were higher than those in normal control group (P < 0.05). The concentration of SOD, IL-6, IL-8 and TNF-alpha MEE was remarkably higher than that in blood plasma (P < 0.01). It revealed that the shorter the course, the higher the concentration of IL-6 or IL-8 in MEE (P < 0.01, or P < 0.05), and the longer the course, the higher the concentration of SOD or TNF-alpha in MEE (P < 0.01, P < 0.05). IL-6 and IL-8 concentration of MEE in serous fluid group was remarkably higher than those in the mucous fluid group (P < 0.01, P < 0.05), and the concentration of SOD and TNF-alpha of MEE in the mucous fluid group was higher than that in the serous fluid group (P < 0.01, P < 0.05). SOD Level of MEE was positively correlated with TNF-alpha (r = 0.587, P < 0.01). CONCLUSION: SOD, IL-6, IL-8 and TNF-alpha might be important mediators in MEE secretion in SOM. IL-6 and IL-8 might participate in the defensive reaction of organism during the early stages of SOM. SOD and TNF-alpha might be closely related to the persistence of SOM, and might be mediators of mucin secretion in SOM.

Adolescent↗

PubMed2001

[Experimental studies on antitumor effect by the new recombinant tumour necrosis factor and cyclophosphamide in nude mice bearing laryngeal carcinoma].

OBJECTIVE: We aimed at finding ideal biological treatment and regime for laryngeal carcinoma. METHOD: Nude mice model bearing laryngeal carcinoma were established using laryngeal carcinoma cell line (HEP-2). New recombinant human tumor necrosis factor (NrhTNF-alpha) and cyclophosphamide were administered locally or systemically, single or in combination. The microstructural and ultra-micro-structural changes of carcinoma after administration of NrhTNF-alpha were observed under light and electron microscopes. RESULT: 1. After treatment, the tumor showed hemorrhage, necrosis, regression, the survival time was prolonged. 2. More significant antitumor effect was observed when locally administered NrhTNF-alpha than intravenously administered of NrhTNF-alpha. 3. There is a notable synergistic antitumor effect by the combination use of NrhTNF-alpha and cyclophosphamide. 4. Microscopy showed that cell changes mostly took place in plasma especially in mitochondria and endoplasmic neticula. The mitochondria were highly bloated. Besides, some nuclei were condensed and fragmented resulted in cell death. CONCLUSION: These studies provide experimental basis for biological treatment of laryngeal carcinoma.

Administration, Topical↗

PubMed2001

[Study on the coagulation state of laryngeal cancer patients before and after operation].

OBJECTIVE: To explore the coagulation state of laryngeal cancer patients before and after operation. METHOD: The eight parameters of coagulant system of 46 laryngeal cancer patients were examined before operation, 1 day and 10 days after operation, and compared with control group. RESULT: The result suggests, anticoagulant activity decreased and fibrinolytic activity increased in laryngeal cancer patients before operation. Laryngectomy trauma may worsen the abnormality. With the incision of tumors and recovery from operation trauma, anticoagulant activity and fibrinolytic activity of the patients gradually returned to normal level. CONCLUSION: Coagulation disorders in laryngeal cancer patients had existed in a way. With operation trauma, it may worsen the abnormality. So anticoagulant and fibrinolytic systems of these patients should be taken seriously to prevent thrombosis and bleeding.

Adult↗

PubMed2001

[Research of drug resistance and detection of methicillin-resistant Staphylococcus aureus in chronic maxillary sinusitis].

OBJECTIVE: To investigate the detection method of methicillin-resistant staphylococcus aureus (MRSA) in chronic maxillary sinusitis and the situation of drug resistance to some common antibiotics. METHOD: Using multiplex polymerase chain reaction technique to detect the drug resistant gene (mecA) of MRSA and specific gene (femA) of staphylococcus aureus at the same time. Drug resistant tests were performed with disk diffusion (K-B) method. RESULT: femA is a specific gene of staphylococcus aureus, the detective ratio of mecA in MRSA is 96.2% (51/53). Vancomycin is the only antibiotic which is sensitive to MRSA, while others are not. CONCLUSION: MRSA can be rapidly and specifically identified with multiplex PCR. There are drug resistance to many antibiotic drugs for MRSA.

Adolescent↗

PubMed2001

[Survey on the microbial pollution of pure water in water dispenser and its disinfection].

The counts of bacteria, total coliforms and fungi of pure water in the water dispensers were detected and the regular pattern of bacterial reproduction in water were studied after the dispensers and water were disinfected. The results showed the bacterial pollution in the water dispensers was serious and the bacteria counts increased with the time of using dispensers lasted. The disinfectant could killed effectively the bacteria in the water sources but it could not control the new bacteria polluted and reproduced while the water dispensers were in use. It was suggested that the bacteria polluted from air should be prevented by taking effective methods and selecting appropriate organic materials for making dispensers.

Escherichia coli↗

PubMed2001

A study on the preservation of fresh amniotic membrane.

OBJECTIVE: To establish the standard preservation methods of fresh amniotic membrane for clinical use. METHODS: Human placentas were collected aseptically from selective caesarean sections in normal women in time. Amniotic or placental membrane were peeled and preserved in N. S, P. B. S or DMEM at 4 degrees C or cultured in DMEM at 37 degrees C, 5% CO2. Trypan-blue staining, light and electronic microscopy were observed every six hours after preservation. RESULTS: Seventy percent of amniotic epithelial cells survived after preservation in N.S for 6 hours, PBS 12 hours, DMEM 24 hours and 1 week in tissue culture. The amount of living epithelial cells maintained in placental membrane preservation was less than that in amniotic membrane preservation at the same time (t-test, P < 0.01). No collagen degeneration was found during preservation. CONCLUSION: Preservative solution and time will affect the maintenance time of fresh amniotic membrane greatly. Fresh amniotic membrane should be preserved within 6 hours in N. S, 12 hours in P. B. S, 24 hours in DMEM at 4 degrees C and 1 week in tissue culture for clinical use.

Adult↗

PubMed2001

[Detection of hepatitis C virus from hepatocellular carcinoma and its relationship to hepatocarcinogenesis].

OBJECTIVE: To get an insight of the relationship between hepatitis C Virus (HCV) infection and hepatocellular carcinoma (HCC). METHODS: A molecular pathology research was performed. Liver specimens from 19 HCC cases with HCV infection only were detected for HCV antigen (HCAg) and HCV RNA with monoclonal antibody (McAb) against HCV NS3 antigen by means of immuno-histochemistry staining and in situ hybridization using Dig-labeled full-length HCV cDNA Probe. RESULTS: In 17 of 19 (89.5%) cases, positive expression of the antigen was observed; 11 of 19 (57.9%) cases were positive for HCV RNA. The viral antigen was expressed in cytoplasm and nucleus of para-cancerous hepatocytes and in cancer cells too, while the distribution of HCV RNA was only seen in cytoplasm of hepatocyte. CONCLUSION: These results strongly support the relationship between HCV infection and the occurrence of HCC. The nucleic distribution of HCAg suggests a possible interaction between HCAg and the host genome, which may lead to hepatocarcinogenosis.

Aged↗

PubMed2001

[Investigation on the value of applying interventional radiologic treatment in the management of advanced gynecological malignancies].

OBJECTIVE: To investigate the value of applying interventional radiologic treatment (IRT) in the management of advanced gynecological malignancy. METHODS: Twenty-four historically confirmed advanced gynecological malignancy patients from September 1997 to June 1998 were included. After receiving internal iliac arterial infusion chemotherapy with Seldinger, the patients' tumor tissues were pathologically studied at different times. The tumor size was measured by ultrasonography two weeks after IRT. RESULTS: Before internal iliac arterial infusion chemotherapy, internal iliac arteriography showed that uterus artery was thickened and tortuous, the new vessels appeared and the tumors were stained. In some cases, the image of blood vessel-lake and arteriovenous shunt were seen in tumor tissues. Twenty-four hours after internal iliac arterial infusion chemotherapy, focal necrosis was observed in tumor cells, seventy-two hours after, the necrosis became more thorough. In regard to the tumor size, two patients were CR, nineteen patients were PR, and two patients were NC. Only one patient failed to respond to IRT. Chemotherapy side effects were slight. Patients' WBC returned normal within two weeks after chemotherapy. No complication happened. CONCLUSION: 1. Internal iliac arteriography has practical significance in assessing the tumor size and evaluating the therapeutic effects; 2. the internal iliac arterial infusion chemotherapy can reduce the tumor size, which prepares the patient in a better condition for operation. The most appropriate time for operation is two weeks after internal iliac arterial infusion chemotherapy. Even for the patient who is not suitable for operation, the reduction of the tumor size still can enhance the therapeutic effects of radiotherapy. 3. IRT is easy to perform, effective and with few slight side effects and complication. It is an effective way to save the patient's life.

Adult↗

PubMed2001

[Analysis of alloy tool steel using X-ray fluorescence spectrometer].

This report briefly introduces the analysis of Mn, Cr, V, W, Ti, Nb, Co, Zr, Ni, Mo, S, P, Si and Cu in alloy tool steel with X-ray florescence spectrometer. After being polished with grinding well and being cleaned with ethly alcohol, the test samples can be directly measured, and the results agree well with the standard values of the laboratory standards. The precision of the method (RSD) is in the range of 0.13%-9.56% (n = 8) for all elements except W, Ti, Nb and Zr. The method can be applied to many kinds of steel, such as chrome vanadium steel, manganese steel, die steel, middle-low alloy steel, tool steel. The measure instrument should be rectified with two or three standard samples which the quantity contained is suitable. The standard samples include 1Cr18Ni9Ti, C17Ni2, 25CrMo1V, 30CrMnSiA, 3CrW8V, Gx-8, Cr12MoV, chrome vanadium steel, manganese-boron steel, middle-low alloy steel and other kinds of steel. If there is not conditions to make work curves for all kinds steel separately, sometimes we don't know what kind of steel for one complex sample, the more real way will be to make an overall work curves which contains more kinds of steel as far as possible.

English Abstract↗

PubMed2000

Abeta amyloid fibrils possess a core structure highly resistant to hydrogen exchange.

We describe here experiments designed to characterize the secondary structure of amyloid fibrils of the Alzheimer's amyloid plaque peptide Abeta, using hydrogen-deuterium exchange measurements evaluated by mass spectrometry. The results show that approximately 50% of the amide protons of the polypeptide backbone of Abeta(1-40) resist exchange in aqueous, neutral pH buffer even after more than 1, 000 h of incubation at room temperature. We attribute this extensive, strong protection to H-bonding by residues in core regions of beta-sheet structure within the fibril. The backbone amide hydrogens exchange at variable rates, suggesting different degrees of protection within the fibril. These data suggest that it is unlikely that the entire Abeta sequence is involved in H-bonded secondary structure within the amyloid fibril. Future studies using the methods described here should reveal further details of Abeta fibril structure and assembly. These methods also should be amenable to studies of other amyloid fibrils and protein aggregates.

Amino Acid Sequence↗

PubMed2000

Permeability of antisense oligonucleotide through porcine buccal mucosa.

Antisense oligonucleotides (AONs) that can modulate malfunctioning genes have a great potential to become future therapeutic agents. In this study, we investigated the feasibility of buccal delivery of AONs using ISIS 3082 as a model compound. An isocratic HPLC method was developed to quantify ISIS 3082. The permeability coefficient of this AON at 37 degrees C, determined by using side-by-side diffusion cells, was 1.05x10(-9) (cm/s). The flux of ISIS 3082 across buccal mucosa was dependent upon its concentration in the donor chamber. The permeation of ISIS 3082 was increased when 100 mM of sodium glycocholate was used as a permeation enhancer. The potential of delivering AONs via buccal route with the aid of permeation enhancers is explored in this study.

Animals↗

PubMed2000

Identification and characterization of two neuromedin U receptors differentially expressed in peripheral tissues and the central nervous system.

Two structurally related, G-protein-coupled receptors were identified as receptors for the neuropeptide, neuromedin U. This peptide is found in highest levels in the gut and genitourinary system where it potently contracts smooth muscle but is also expressed in the spinal cord and discrete regions of the brain. Binding sites for neuromedin U have been characterized in rat uterus, however, little is known about the activity of this peptide in the regions of the central nervous system where it is expressed. The receptors characterized in this report are activated by neuromedin U at nanomolar potency in heterologous expression systems and bind radiolabeled neuromedin U with high affinity. Localization of the receptor RNA by quantitative reverse transcription-polymerase chain reaction in a variety of human tissues shows distinct expression patterns for the two receptors. NMU1 is expressed predominantly in peripheral tissues, whereas NMU2 is more highly expressed in the central nervous system. Identification of neuromedin U receptor subtypes will greatly aid in the determination of the physiological roles of this peptide.

Amino Acid Sequence↗

PubMed2000

X-ray crystal structure of rabbit N-acetylglucosaminyltransferase I: catalytic mechanism and a new protein superfamily.

N:-acetylglucosaminyltransferase I (GnT I) serves as the gateway from oligomannose to hybrid and complex N:-glycans and plays a critical role in mammalian development and possibly all metazoans. We have determined the X-ray crystal structure of the catalytic fragment of GnT I in the absence and presence of bound UDP-GlcNAc/Mn(2+) at 1.5 and 1.8 A resolution, respectively. The structures identify residues critical for substrate binding and catalysis and provide evidence for similarity, at the mechanistic level, to the deglycosylation step of retaining beta-glycosidases. The structuring of a 13 residue loop, resulting from UDP-GlcNAc/Mn(2+) binding, provides an explanation for the ordered sequential 'Bi Bi' kinetics shown by GnT I. Analysis reveals a domain shared with Bacillus subtilis glycosyltransferase SpsA, bovine beta-1,4-galactosyl transferase 1 and Escherichia coli N:-acetylglucosamine-1-phosphate uridyltransferase. The low sequence identity, conserved fold and related functional features shown by this domain define a superfamily whose members probably share a common ancestor. Sequence analysis and protein threading show that the domain is represented in proteins from several glycosyltransferase families.

Amino Acid Sequence↗

PubMed2000

Metabolic response of Platynota stultana pupae to controlled atmospheres and its relation to insect mortality response.

The metabolic responses of Platynota stultana pupae to reduced O(2), elevated CO(2), and their combinations were investigated using microcalorimetry, and mortality of pupae under elevated CO(2) atmospheres was correlated with metabolic responses. The metabolic heat rate decreased slightly with decreasing O(2) concentration until a critical O(2) concentration (P(c)) below which the heat rate decreased rapidly. The P(c) increased with temperature. The percentage decreases of metabolic heat rate were comparable to the percentage decreases of O(2) consumption rate (RO(2)) at 10, 8, 6, and 4% O(2), but were smaller at 2 and 1% O(2). The metabolic heat rate decreased rapidly at 20% CO(2) relative to 0% CO(2), with little to no further decrease between 20 and 79% CO(2). The percentage decreases of RO(2) under 20 and 79% CO(2) at 20 degrees C were comparable to the percentage decreases of metabolic heat rates. The additive effects of subatmospheric O(2) and elevated CO(2) levels on reducing metabolic heat rate were generally fully realized at combinations of </=5% CO(2) and >/=4% O(2), but became increasingly overlapped as the O(2) concentration decreased and the CO(2) concentration increased. The high susceptibility of pupae to elevated CO(2) at high temperature was correlated with high metabolic heat rate. The metabolic responses of pupae to reduced O(2) concentrations included metabolic arrest and anaerobic metabolism. The net effect of elevated CO(2) on the pupal respiratory metabolism was similar to that of reduced O(2); however, mechanisms other than the decrease of metabolism were also contributing to the toxicity of CO(2).

Journal Article↗