[Repair of the facial nerve defects with non-nerve materials].
Explore the source record for details and available documents.
Animals↗
Biomedical subjects
Z Tao
Publications and source records attributed to Z Tao.
[Oculocardiac reflex in senile cataract operation].
OBJECTIVE: To determine the incidence of the oculocardiac reflex and to identify which steps in the process in senile cataract operation are more important in eliciting the reflex. METHODS: Dynamic electrocardiogram was recorded with a 24 hour Holter's monitoring at the time of following steps: preoperation, retrobulbar anesthesia, softening of eyeball, superior rectus suture, corneoscleral incision, delivery of the nucleus and posterior chamber lens implantation. Oculocardiac reflex was defined as at least a 10% decrease in heart rate below relative baseline. RESULTS: 14 times of oculocardiac reflex occurred in 10 of 30 patients (33.3%). All maneuvers except for superior rectus fixation triggered the reflex in our group. In addition, premature beat was noted in 5 patients. CONCLUSION: Our patients indicate that cataract extraction may result in abnormalities in both heart rate and rhythm. The definition of the oculocardiac reflex may be too conservative and requires redefinition.
Aged↗
[Transmission electron microscopic study on eosinophil degranulation in nasal mucosa in allergic rhinitis].
To observe the ultrastructure of eosinophil (EOS) degranulation in nasal mucosa in allergic rhinitis, nasal mucosa biopsies from patients with perennial allergic rhinitis (PAR, n = 13) pollinosis (PS, n = 9) subjects and normal controls (n = 3) were processed and the ultrastructure changes of EOS degranulation were examined under transmission electron microscope and routine histopathological observation. The ultrastructure of EOS degranulation in nasal mucosa collected from PAR and PS patients in their remission period differed from that in their attacking period, though there was no distinct differences in the distribution patterns of EOS. Increased cell membrane projections, eminent cytoplasm vacuolization, inconsistent density of granules with its crystalloid being lost, plus tissue edema and damage of collagen fibers in adjacent areas of degranulating EOS were among the most important ultrastructural changes of EOS in attacking period. The interrelations of EOS, mast cells (MC) and T-lymphocytes play important roles in the pathogenesis of allergic rhinitis.
Adult↗
Changes in tachykinin--ergic nerve terminal densities in rat nasal mucosa during hypersensitivity.
OBJECTIVE: To further carry out a quantitative immunohistochemical study on neuropeptides (NPs) participation in perennial allergic rhinitis (PAR) in nasal mucosa. METHODS: By using light microscopy (routine hematoxylin and eosin staining, Wright's staining and 1% toluidine blue staining) and scanning as well as transmission electron microscopy, an exhaustive immunohistochemical and morphometric study was made on the changes of substance P (SP), neuropeptide A (NKA) and neuropeptide B (NKB) in the nasal mucosa of a toluene-2,4-iso-cyanate (TDI)-induced PAR model of rat. RESULTS: The results showed that the densities of all three peptidergic terminals were significantly increased (P < 0.01) in experimental group (115.72 +/- 28.43 for SP, 39.23 +/- 10.34 for NKA and 37.24 +/- 11.22 for NKB, respectively) as compared with those in control group (49.65 +/- 11.23 for SP, 12.44 +/- 6.21 for NKA and 13.31 +/- 7.60 for NKB, respectively). Increased staining, thickening of peptidergic terminals and enlargement of varicosities were found. Mast cell infiltration in nasal mucosa was in parallel with increase of peptidergic terminals. CONCLUSION: All results support the hypothesis that NP is a newly-recognized but potentially important factor in the pathogenesis of PAR.
Animals↗
Detection of c-myc gene expression in nasopharyngeal carcinoma by nonradioactive in situ hybridization and immunohistochemistry.
OBJECTIVE: To investigate the c-myc gene expression in nasopharyngeal carcinoma (NPC) at mRNA and protein levels, and to evaluate the relationship between the degree of expression and the clinicopathological data. METHODS: The expression of c-myc specific mRNA and protein was detected using in situ hybridization with digoxigenin-labeled probe and immunohistochemistry in 12 cases of normal nasopharyngeal epithelium (NE) and 48 cases of NPC. The intensity of staining for each sample was assessed as negative, weak, moderate and intense. Statistical analyses were performed using the Chi square test and the rank sum test. RESULTS: For normal NE 41.7% (5/12) had weak (4/12) or moderate (1/12) staining for c-myc protein and 41.7% (5/12) had weak staining for c-myc mRNA. In contrast, 89.6% (43/48) of NPC showed some degree of c-myc protein positive and 87.5% (42/48) showed some degree of c-myc mRNA positive. In most samples, the expression of c-myc protein was consistent with that of c-myc mRNA. C-myc protein and mRNA expression levels in NPC were significantly higher than those in normal NE, and correlated with early recurrence, but they were not significantly related to patient's age, sex, EBVCA-IgA titre, disease stage, lymph node status and metastasis. CONCLUSIONS: C-myc gene over-expression may be involved in the pathogenesis and early recurrence of NPC. Further studies are needed to substantiate the preliminary findings.
Gene Expression↗
[Carotid body tumor (report of 4 cases)].
Four cases of carotid body tumor are reported, and the diagnosis and treatment are also discussed. We consider that color Doppler flow image and carotid angiography, especially digital subtraction angiography, are of great value to the diagnosis of carotid body tumor. In addition, the collateral cerebral cross-flow was promoted preoperatively with the use of compressing exercises of the carotid artery, and controlled by transcranial Doppler. This means to provide the basis for choosing the operative opportunity and for managing the carotid artery. The operative method was dependent on preoperative color Doppler flow image, carotid angiography, and relationship between the tumor and the carotid artery during operation.
Adult↗
[Tumours of the nose and sinuses presented as nasal polyp].
Twelve cases of tumours of the nose and sinuses misdiagnosed at the first time as nasal polyp are reported. Of them, 4 were benign and 8 malignant. The endoscopic technique is helpful to differential diagnosis of benign or malignant lesions and polyps in these areas.
Adult↗
[The spontaneous otitis media in rickety rats].
This paper is aimed to study the incidence and hearing impairment of spontaneous otitis media in rickety rats during a longterm vitamin D deficient breeding. Thirty Sprague-Dawley rats ranged from 20 to 25-day-old were used, and vitamin D deficient rickets models were established. Another thirty rats were used as the normal control. It was found that both normal and rickety rats had the possibilities of suffering from otitis media (mainly exudative) during the two-month-breeding. The incidence of otitis media in normal rats was 5% (3 from 60 ears), while that in the rickety ones was 16.67% (10 from 60 ears). It is believed that a rickety sufferer may be in higher danger of having otitis media than the normal one.
Action Potentials↗
[A preliminary study on p53 gene expression and infection of human papilloma virus in laryngeal squamous cell carcinoma].
Using immunohistochemical techniques with p53 monoclonal antibody DO-7 and polymerase chain reaction with type specific primers, we detected the expression of p53 of laryngeal and hypopharyngeal squamous cell carcinoma (L-HSCC) in 42 patients, tissues around tumor in 25 patients, human papilloma virus (HPV) 16/18 DNA in paraffinembedded carcinoma tissues from 13 patients with laryngeal squamous cell carcinoma (LSCC). The results showed that overexpression of p53 was detected in 54.8% (23/42) of L-GSCC and 20% (5/25) of hyperlasia epithelia, respectively. There was no correlation of p53 overexpression with clinical stages and histological grading of tumors (P > 0.05). HPV16 DNA encoding E6 protein was detected in 23.1% (3/13) LSCC tissues by PCR. The results suggest that overexpression of p53 and HPV infection are not only associated with pathogenesis of this kind of cancer but also cooperated during carcinogenesis.
Aged↗
Inhibition of rat parotid gland growth response induced by chronic isoproterenol following treatment with quinolone antibiotics.
While antibiotics are broadly used in dental and medical therapy, little attention has been directed towards the potential toxic side effects of antibiotics on tissue regeneration. Here we examined the effect of a quinolone antibiotic, pefloxacin (Rhone Poulenc) on rat parotid gland responses to chronic isoproterenol treatment. Groups of rats received injections of isoproterenol to induce glandular growth, saline (controls), pefloxacin, or isoproterenol and pefloxacin in combination. Parotid gland weight decreased significantly after pefloxacin treatment for 7 days as well as inhibiting glandular enlargement provoked by isoproterenol. The same trend was observed for the rates of DNA synthesis, with the incorporation of [3H]-thymidine in isoproterenol/pefloxacin-treated rats reduced to 49% of isoproterenol treatment alone levels. Saline-treated animals were 42% of the rate of [3H]-thymidine incorporation into DNA observed in isoproterenol treated rats. While isoproterenol treatment increased steady-state mRNA levels for fos, jun, myc, src, c-erbB-2, ras and topo II, inclusion of pefloxacin with the isoproterenol regimen blocked these increases. Pefloxacin treatment by itself did not alter proto-oncogene mRNA levels in the parotid gland. Glandular amylase activity was decreased in the pefloxacin treated group, while the combination of isoproterenol with pefloxacin did not decrease glandular amylase levels to the extent of that observed with beta-agonist treatment alone. In acute experiments, pefloxacin significantly decreased the volume of saliva secreted by the parotid gland. These results suggest that quinolone-based antibiotics disturb the secretory function of the parotid gland and can inhibit cell proliferation and regeneration.
Adrenergic beta-Agonists↗
Radiative seesaw mechanism at the weak scale.
Explore the source record for details and available documents.
Journal Article↗
Marked alteration of proteoglycan metabolism in cholesterol-enriched human arterial smooth muscle cells.
To elucidate the correlation between vascular cholesterol metabolism and proteoglycan (PrGl) biosynthesis, we investigated PrGl synthesis in human aortic smooth muscle cells (SMCs) after cholesterol enrichment with cationized low-density lipoproteins (LDL). Compared with normal SMCs, total PrGl synthesis by cholesterol-enriched cells decreased 2.4-fold (11874 +/- 530 d.p.m. per 10(5) cells compared with 4890 +/- 385 d.p.m. per 10(5) cells). This was the net result of a 6.9-fold reduction in medium PrGl (11000 +/- 490 d.p.m. per 10(5) cells compared with 1580 +/- 246 d.p.m. per 10(5) cells) and a 3.8-fold increase in cellular PrGl over controls (874 +/- 27 d.p.m. per 10(5) cells compared with 3310 +/- 193 d.p.m. per 10(5) cells). Prior incubation of SMCs with native LDL had no effect on PrGl synthesis by these cells. The decrease in PrGl synthesis in cholesterol-enriched cells correlated with a 90% and 20% reduction in the steady-state level of mRNA for biglycan and decorin respectively, and a virtual elimination of the steady-state level of mRNA for versican over controls. Despite the down-regulation of PrGl synthesis, cholesterol-loaded cells produced a 2-fold increase in a PrGl subfraction with high affinity for LDL. Compared with the corresponding PrGl subfraction from normal cells, that from the cholesterol-enriched cells exhibited increased charge density and a higher molecular mass and contained relatively larger proportions of chondroitin 6-sulphate and dermatan sulphate. These results show that PrGl metabolism is dramatically altered in cholesterol-enriched human SMCs.
Biglycan↗
Bis(31/31') ([CYS(31), Trp(32), Nva(34)] NPY-(31-36)): a specific NPY Y-1 receptor antagonist.
Explore the source record for details and available documents.
Animals↗
Adaptation of chondrocytes to low oxygen tension: relationship between hypoxia and cellular metabolism.
In endochondral bone, the growth cartilage is the site of rapid growth. Since the vascular supply to the cartilage is limited, it is widely assumed that cells of the cartilage are hypoxic and that limitations in the oxygen supply regulate the energetic state of the maturing cells. In this report, we evaluate the effects of oxygen tension on chondrocyte energy metabolism, thiol status, and expression of transcription elements, HIF and AP-1. Imposition of an hypoxic environment on cultured chondrocytes caused a proportional increase in glucose utilization and elevated levels of lactate synthesis. Although we observed a statistical increase in the activities of phosphofructokinase, pyruvate kinase, lactate dehydrogenase, and creatine kinase after exposure to lowered oxygen concentrations, the effect was small. The cultured cells exhibited a decreased utilization of glutamine, possibly due to down regulation of mitochondrial function and inhibition of oxidative deamination. With respect to total energy generation, we noted that these cells are quite capable of maintaining the energy charge of the cell at low oxygen tensions. Indeed, no changes in the absolute quantity of adenine nucleotides or the energy charge ratio was observed. Hypoxia caused a decrease in the glutathione content of cultured chondrocytes and a concomitant rise in cell and medium cysteine levels. It is likely that the fall in cell glutathione level is due to decreased synthesis of the tripeptide under reduced oxygen stress and the limited supply of glutamate. The observed rise in cellular and medium cysteine levels probably reflects an increase in the rate of degradation of glutathione and a decrease in synthesis of the peptide. To explore how cells transduce these metabolic effects, gel retardation assays were used to study chondrocyte HIF and AP-1 binding activities. Chondrocyte nuclear preparations bound an HIF-oligonucleotide; however, at low oxygen tensions, no increase in HIF binding was observed. In addition, we found that AP-1 binding activities in chondrocytes exposed to low oxygen tensions was elevated, although the response was lower than that exhibited by fibroblasts exposed to the same range of oxygen concentrations. We compared these results to HIF and AP-1 binding by cells in the growth plate. There was strong HIF and AP-1 binding throughout the plate, but no evidence of selective binding to any one zone. The results of the study lend strong support to the view that chondrocytes are very well adapted to low oxygen tensions; thus, under hypoxic conditions, there is a high level of expression of both HIF and AP-1, and energy conservation appears to be near-maximum.
Adenine Nucleotides↗
Synthesis, structure, and antagonistic properties of des-Asn29[D-Trp28,32]NPY(27-36).
We have previously reported that [D-Trp32]NPY and its centrally truncated analogues such as des-AA7-24[D-Trp5,32,Aoc6]NPY can competitively antagonize NPY effects on rat hypothalamus and Y1 (SK-N-MC AND HEL) cells, respectively. In continuation of this work, we performed structure-activity studies with C-terminal decapeptide sequence keeping D-Trp at position 32 to develop lower molecular weight Y1-selective antagonists. This study led to the development of des-Asn29[D-Trp28,32]NPY(27-36), which bound to both Y1 (SK-N-MC, Ki > or = 10 microM) and Y2 (SK-N-BE2, Ki = 1.01 +/- 0.03 microM) receptors. This peptide did not exhibit any agonist activity at Y1 receptors, and exhibited comparable potencies in antagonizing the effects of NPY on the synthesis of cAMP and mobilization of [Ca2+]i in HEL cells. However, in SK-N-MC cells, it was more potent in antagonizing the mobilization of [Ca2+]i than inhibition of cAMP synthesis. Substitution of Nva for Gln34 to increase the hydrophobicity without altering the carbon skeleton substantially increased Y1 affinity (Ki = 0.33 +/- 0.15 microM) and imparted Y1 selectivity (Ki for Y2 affinity = 3.16 +/- 0.50). Moreover, this peptide exhibited good antagonistic potency in HEL cells. 2D NMR studies of des-Asn29[D-Trp28,32]NPY(27-36) revealed the existence of a fairly stable loop-like structure between residues 27 and 32 and a less stable one between residues 32 and 36. The increased Y1 affinity of des-Asn29[D-Trp28,32,Nva34]NPY(27-36) may be due to the stabilization of the 32-36 loop by Nva34. It appears therefore that stabilization of the loop structures in these peptides should result in the development of more potent Y1 receptor antagonists. Our investigations also suggest that HEL cells express a homogeneous population of NPY Y1 receptors whereas SK-N-MC cells express high- and low-affinity Y1 receptors coupled to Ca2+ and cAMP, respectively.
Animals↗
Alterations in the level of phosphotyrosine signal transduction constituents in human parotid tumors.
Human parotid tumors were evaluated for the activation of the phosphotyrosine signaling pathway by Western blot, enzyme activity assay, and reverse transcriptase-polymerase chain reaction. Warthin's tumor and mucoepidermoid carcinomas had the greatest level of tyrosine phosphorylated proteins identified in plasma membrane fractions. These tumors, along with pleomorphic adenocarcinoma, showed high levels of membrane expression of the tyrosine kinase receptor, c-erbB-2, and phosphatidylinositol-3-kinase. Expression of the epidermal growth factor receptor was confined to normal tissue. The level of mRNA for c-erb was elevated only in mucoepidermoid carcinomas. Messenger RNA levels for ras were unchanged from control levels in all tumors, while the level of src mRNA was higher in the tumor samples than the normal parotid tissue. The activities of several signal transduction kinases, including protein kinase A and C were elevated in tumor tissue (7.7- to 18.9- and 0.4- to 3.7-fold higher, respectively), relative to surrounding normal tissue. While the level of glandular amylase was reduced (22%-0% of normal levels) in the tumor tissue, epidermal growth factor (EGF) and transforming growth factor-alpha (TGFalpha) content was dramatically higher in the neoplastic tissue (10- to 170-fold and 4.6- to 6.0-fold, respectively). These results suggest that with the presence of elevated levels of EGF, TGFalpha, and the oncoprotein receptor c-erbB-2 in the membrane of parotid tumors, cell proliferation and activation of the phosphotyrosine signal transduction pathway may involve autocrine stimulation through the expression of high levels of growth factor and receptor in the same tissue.
Base Sequence↗
[Study on distributions of somatostatin in rat nasal mucosa and trigeminal ganglion].
To explore the regulatory mechanism of the release of neuropeptides in nasal mucosa, the distributions of somatostatin (SOM) and SOMmRNA-immunoreactivities (IR) in cryostat sections of rat nasal mucosa and trigeminal ganglion (TG) cells were investigated using immunohistochemistry (ABC technique) and in situ hybridization histochemistry. The recombinant PSP65 plasmid (400 SOMcDNA) in vitro worked as a plate for the preparation of SOMmRNA single strand (cRNA) probe, which was labelled with digoxigenin. The results showed that neither of these two substances reacted positively in nasal mucosa but positive SOM-IR and SOMmRNA-IR signals were definitely seen in TG cells. In contrast with SOM immunohistochemistry, SOMmRNA-IR positive granules tended to be located in the cytoplasm of TG cells, with a clearer background and a higher resolution rate. The significance of SOMmRNA in TG cells was briefly discussed. It was concluded that SOMmRNA in TG cells might be involved in the regulation of the release of neuropeptides in nasal mucosa.
Animals↗
[Electro-acupuncture effects on experimental spinal cord injury of the cat as evaluated by acid phosphatase detection].
The spinal cords of adult cats were injured at about L1 level by using Allen's method and the animals were divided randomly into 2 groups: a) electro-acupuncture treatment group and b) control group. The acid phosphatase (ACP) was detected at 3 and 7 days after spinal cord injury. The more ACP positive labelings were found in the treatment group than in the control group at both 3 (P < 0.05) and 7 days (P < 0.01) after injury. The results suggested that electro-acupuncture could increase the concentration of ACP of the injured spinal cord and the increased ACP concentration could make worse to the injured spinal cord at early time and improve regeneration during recovery period.
Acid Phosphatase↗