[Hydroxyapatite for experimental laryngotracheal reconstruction]

OBJECTIVE

The porous hydroxyapatite (HA) tubiform prosthesis was employed for reconstruction of large circumferential defect of the larynx and cervical trachea. The biocompatibility, bioactivity and biofunctionality of the HA prosthesis were evaluated, and the feasibility for laryngotracheal reconstruction was discussed.

METHODS

Twelve healthy canines were used to establish the experimental models, a large portion of cricoid cartilage and upper ten-ring segment of cervical trachea were resected and substituted with a corresponding 5 cm HA prosthesis by end-to-end anastomosis. Six months later, the eight survival canines were sacrificed and the HA prostheses with surrounding tissues were removed. They were observed in decalcified sections by optical microscopy and scanning electron microscopy.

RESULTS

Two canines died in the immediate postoperative period with unknown reason and another two deaths were attributed to obstruction caused by the complete dislocation of the HA prostheses owing to rupture of the sutures within three weeks after operation. Eight canines survived up to six months. The implanted HA prostheses were tolerated in all cases without any rejection and dislocation or shift. An excellent airway was obtained and no signs of dyspnea and suffocation were found though there were hypergranulation and scar formation occurred at the site of anastomosis. Morphologic examination revealed that collagen fibers, new vessels and plenty of cells penetrated deeply into the pores of HA, and occupying the outer two third of HA wall. HA prostheses were surrounded by connective tissues and anchored firmly to the neighboring tissues, including the ends of the cricoid and tracheal cartilage by ingrowths of cartilaginous tissue into the macropores of the HA. However, the luminal surface of HA prosthesis was not covered at all section levels by respiratory mucosa.

CONCLUSIONS

The implantation of the porous HA tubiform prosthesis can maintain the normal respiratory function of the experimental canines, but the proliferating granulation and scar formation at the anastomotic site are questions still remained to be solved. To cover the inner surface of HA with the epithelial mucosa and then reduce the morbidity caused by scar and hypergranulation, some forms of allografts such as pedicled flaps and jejunal autografts will be deserved.

[Experimental study on polyaspartic acid inhibition of gentamicin-induced generation of reactive oxygen species in guinea pig cochlea]

OBJECTIVE

To observe the polyaspartic acid(PAA) inhibition of gentamicin-induced reactive oxygen species generation in cochlea of guinea pig and to investigate the protective mechanism of polyaspartic acid on gentamicin ototoxicity.

METHODS

Eighty-eight guinea pigs were divided randomly into four groups (GM, PAA + GM, PAA, and Saline). Gentamicin-induced reactive oxygen species (ROS) formation in cochlear tissue was detected directly with electron paramagnetic resonance (EPR) spectrometry at 1st, 5th and 10th day after administration of the drugs. At the same time, ABRs of guinea pigs were recorded and ultrastructural changes of lysosomes in the cochlear hair cells were observed with transmission electron microscopy.

RESULTS

1. At 1st day after administration of PAA and GM, there was some increase in EPR spectrometry in group GM and PAA + GM, There was no significant difference of ABR thresholds and ultrastructural changes of lysosomes in the cochlear hair cells among four groups(P > 0.05). 2. At 5th day, there was significant increase in of EPR spectrometry in group I (37.74 +/- 4.10, P < 0.01). At 10th day after administration of PAA and GM, there was no significant difference in EPR spectrometry among four groups (P > 0.05). In GM group, ultrastructural changes of lysosomes beneath cuticular plate of cochlear hair cells were more significant at 10th day than those at 5th day, including the increased number and volume of lysosome. In group GM, the longer the gentamicin administrated, the more significant increase in ABR thresholds had been noted.

CONCLUSION

PAA significantly inhibits gentamicin-induced reactive oxygen species generation in cochlea of guinea pig, which showed that PAA has protective effect on gentamicin-ototoxicity and -phospholipidosis in guinea pigs.

[Evaluation of clinical application of intravascular ultrasound image]

OBJECTIVE

To prospectively evaluate the clinical applications of intravascular ultrasound (IVUS).

METHODS

Four hundred and thirty seven patients with coronary artery disease (CAD) or suspect CAD were imaged with CAD and IVUS, including (1) assessment IVUS in 135 cases with normal coronary angiography (CAG) (2) comparison IVUS with CAG pre and after angioplasty in 52 patients with CAD (3) assessment of detecting calcification lesions with CAG and IVUS in 150 patients (4) predicting the cardiac events after stent implantation guided by IVUS (n = 47) and CAG (N = 53).

RESULTS

IVUS may detect coronary atherosclerosis lesions with normal by CAG. CAG overestimated effect of angioplasty. IVUS was more accurate to determine effect and complications of PTCA compared with CAG. IVUS interpreted the mechanism of vessel dilatation in PTCA. The cardiac events after stent implantation were significantly reduced after IVUS examination as compared with CAG.

CONCLUSIONS

IVUS represents a radically different approach to vascular anatomy. Unlike angiography, which displays the coronary artery as a silhouette of the contrast-filled lumen, IVUS generates a cross-sectional tomographic image of the lumen and vessel wall. IVUS plays an important role as a guidance in cardiac intervention.

Regional glucose metabolic increases in left auditory cortex in tinnitus patients: a preliminary study with positron emission tomography

OBJECTIVE

To investigate the relationship between tinnitus and glucose metabolism in auditory cortex and whether positron emission tomography (PET) can be an objective tool in measuring tinnitus.

METHODS

Eleven right-handed patients with severe tinnitus and ten right-handed control subjects participated in the 18F-FDG/PET study. Analysis with regions of interests was used to calculate asymmetry indices according to the formula: [(L-R) x 100/[(L + R) divided by 2]].

RESULTS

Glucose metabolism in the auditory cortex of tinnitus patients was asymmetric between the left and right auditory cortices, with that of the left being much higher than that of the right. The asymmetry indices of tinnitus patients was significantly higher than that of the control group (unpaired t test, P < 0.001). This revealed that the increased metabolic activity was present in the predominant left hemisphere with a significant focus on the superior and transverse temporal gyri (Brodmann areas 41 and 42, respectively corresponding to primary and secondary auditory cortex), and the results were independent of the subjective localization of the tinnitus sensation.

CONCLUSION

It is suggested that the increased metabolism in the left auditory cortex is related to the tinnitus sensation. PET is capable of providing objective evidence for tinnitus and may be used as a potential tool in measuring tinnitus.

[The characteristic unit discharges related to epilepsy recorded synchronously from dual hippocampi induced by tetanization of the right dorsal hippocampus in rats]

AIM

To study the characteristics of unit discharges related to epilepsy of hippocampal neuron in both hemispheres in intact rats.

METHODS

44 pairs of cells were extracellularly recorded with dual glass microelectrodes from bilateral hippocampi before or after administration of repetitive tetani (0.4 - 0.6 mA, 2 s, 60 Hz) to the right dorsal hippocampus. Repeated tetani were used about ten times at 5 or 10 min intervals to ensure full expression of afterdischarges without the tissue being in postictal refractory period.

RESULTS

Primary or secondary unit afterdischarges of hippocampal neurons were evoked by tetani. They were characterized by bilateral asymmetry, moveability and interconversion between two hemispheres, which were observed in temporal lobe epileptic humans. In addition facilitatory or inhibitory, modulating or demodulating effect of tetani on spontaneous unit discharges depended on the basic firing rates or patterns of hippocampal cells before stimulation. Rhythmic cell bursting of the hippocampus was demodulated to tonic firing by Scopolamine (0.05 mg/kg, i.p.). Tetanus-induced inhibition of hippocampal unit discharges was observed after administration of scopolamine.

CONCLUSION

Abnormal electrophysiological activity of bilateral hippocampi neurons evoked by tetanus may be the pathophysiological bases for dual hemispherical sclerosis and atrophy in temporal lobe epilepsy.

[Effects of intestinal endotoxemia on the development of cirrhosis in rats]

OBJECTIVE

To explore the effect of endotoxin on the development of cirrhosis.

METHODS

The cirrhosis model with intestinal endotoxemia was made by oral intake of 0.03% thioacetamide for four months to observe the effect of endotoxin on the hepatic collagen contents in both thioacetamide and thioacetamide + lipopolysaccharide groups and to detect the contents of tumor necrosis factor-alpha (TNF-alpha), endothelin-1 (ET-1), nitric oxide (NO), and malondialdehyde (MDA) in the plasma and the hepatic homogenate.

RESULTS

The contents of TNF-alpha, ET-1, NO, and MDA in the plasma and the hepatic homogenate and the content of collagen in the hepatic tissue in the two groups were higher than those in the normal control group.

CONCLUSIONS

Endotoxin can accelerate liver fibrosis and the formation of cirrhosis.

Cholinergic agonists increase intracellular calcium concentration in guinea pig vestibular hair cells

OBJECTIVE

To better understand the cholinergic receptors in vestibular hair cells (VHC) and their subtypes, and to investigate the effects of cholinergic agonists on intracellular calcium concentration ([Ca2+]i) in guinea pig VHCs.

METHODS

VHCs were isolated from guinea pig crista ampullaris by enzymatic and mechanical methods. The effect of cholinergic agonists on [Ca2+]i was examined using laser scanning confocal microscopy and the Ca2+ sensitive dye Fluo-3.

RESULTS

The results showed that the addition of acetylcholine (ACh) and carbachol (CCh), muscamic and nicotinic agonists, induced [Ca2+]i increases in all the VHCs, whereas acetylcholine bromide (ACh-Br), a nicotinic agonist, induced the [Ca2+]i increase in only a small percentage of VHCs. The ACh or CCh-induced Ca2+ response could be partially suppressed by atropine. In the presence of 0.1 mmol/L atropine, the amplitudes of ACh or CCh-induced [Ca2+]i responses became significantly smaller than those in atropine free medium (P < 0.01).

CONCLUSIONS

The results suggest the existence of cholinergic receptors in guinea pig VHCs. It is the muscamic agonists rather than nicontic receptors that dominate [Ca2+]i variation. Atropine can suppress muscamic agonist-induced Ca2+ responses.

[Analysis and separation of chromium(III) oligomers by ion chromatography]

A method of analyzing chromium(III) oligomers in aqueous solution by means of TSK-Gel ion exchange analytical column and diode array detector was developed. The effects of determination conditions, elution and ionic strength on analysis were investigated carefully and the analytical condition was optimized. The samples were separated for 10 min by using TSK-Gel SP-5PW(75 mm x 7.5 mm i.d., 10 microns) as column, 3 mol/L NaClO4-0.03 mol/L HClO4 as mobile phase, and detected at the wavelength of 200 nm. The method was simple, rapid and repeatable. This method was also used to determine the concentration of each fraction under various conditions of preparing chromium(III) oligomers and rendering the optimized preparation parameters.

Characteristic behavioral seizures and abnormal signal asymmetry of magnetic resonance imaging in an electrogenic rat model of chronic epilepsy

Chronic tetani (60 Hz, 2 s, 0.4~0.6 mA) were administered to the dorsal hippocampus (DHPC) or the medial temporal lobe neocortex (MTNC) of rats, to study the role of the entorhinal cortex (EC)-hippocampal loop in temporal lobe epileptogenesis. This was repeated once a day for 7 or 10 days. Magnification of hyper-intensity was induced by tetanization of the HPC or the MTNC, as detected by contralateral T(2) weighed magnetic resonance imaging (T(2)-WI). The effects were associated with an enlarged volume of the lateral ventricle (LV), which was verified histologically. T(2)-WI hper-intensities, contralateral to the tetanized hemispheres, were observed with high frequency primary wet dog shakes (WEDS) in the DHPC-stimulated rats and with low frequency WEDS in the MTNC-stimulated rats. It seems likely that the same neural mechanisms are shared by chronic tetanization of the right HPC and the righ MTNC, involving the closed EC-HPC loop. Poor correlation between contralateral T(2)-WI hper-intensities and light primary behavioral seizures in the MTNC-stimulated rats might be attributed to a controlled information flow into or out of this loop because of potential EC gating. In addition, asymmetric T(2)-WI hyper-intensities in the LV area reflected a hemispheric dependence, contralateral to the electrogenic focus in our model of rat epilepsy.

Possible role of dentate gyrus in greneration of rat temporal lobe epilepsy induced by electrical stimulation

Possible role of the dentate gyrus (DG) and the hippocampus (HPC) in temporal lobe epileptogensis was investigated in an electrogenic model of rat epilepsy. Chronic tetani (60 Hz, 0.4-0.6 mA. 2 s) were administered once daily for 7 days to the right dorsal hippocampus (DHPC) or the right DG. Animal behavior was observed and depth electro-graphic seizures and T(2)-weighted magnetic resonance images (T(2)-WI) were measured. Results indicated that the frequency of primary wet dog shakes (WEDS) in the DG-stimulated rats was much lower than that in the DHPC-stimulated rats (P<0.05). The mean maximal wave-amplitude in DG electrographs was also much lower than that in HPC electrographs (P<0.05). The oscillations proportion of DHPC electrographs increased after DHPC-tetanization (from 2/9 up to 7/9 rats). T(2)-WI hyperintensity in the lateral ventricle area was detected only in the DHPC-tetanized rats, not in the DG-tetanized rats (P<0.05). These results suggest that the DG acts as a filtering site in the entorhinal cortex-HPC neuronal circuitry and its dysfunction causes damage to the HPC and the generation of temporal lobe epilepsy.

Authentication of Chinese crude drug, Gecko, by allele-specific diagnostic PCR

Based on the sequences of the mitochondrial 12S rRNA gene fragment of 17 samples from Gekkonidae, Salamandridae, Agamidae and Hynobiidae, respectively, a pair of allele-specific primers was designed for differentiating the Chinese medicinal material Gecko from its adulterants by PCR. The results of amplification with the primers indicate that amplicons from the templates of Gekko gecko were clearly revealed by agarose gel electrophoresis, whereas no evident amplicons were found from other species. The primers were employed to identify crude drug samples from different sources. Among a total of 9 samples, 3 were diagnosed as genuine Gecko. This result is consistent with morphological identification and DNA sequence analyses.

[Multiple factors analysis of intraoperative bleeding and recurrence of juvenile nasopharyngeal angiofibromas]

OBJECTIVE

To study the effect of surgical treatment of juvenile nasopharyngeal angiofibromas and the factors influencing intra-operative bleeding and recurrence.

METHODS

Thirty-four patients with juvenile nasopharyngeal angiofibromas treated surgically in Chinese PLA General Hospital between 1986 and 1999 were studied retrospectively. The relationship between surgical treatment, intraoperative bleeding, recurrence and age, duration, staging, preoperative treatment, times of previous operation, operative approaches was statistically analyzed.

RESULTS

The tumors were totally resected in 30 patients, and five patients(16.7%) recurred during a mean follow-up of 77 months. The mean recurrence time after operation was 3.2 months (1-6 months). The amount of intraoperative bleeding correlated well with the age, duration, staging, preoperative treatment, and surgical approaches (P < 0.05), but not with times of previous operation (P > 0.05). Recurrence was not correlated with the age, duration, preoperative treatment and surgical approaches (P > 0.05), but correlated with staging (P < 0.05).

CONCLUSION

The factors significantly influencing the intraoperative bleeding were the age, duration and staging. Recurrence was correlated with the tumor stages, incomplete resection or the exceedingly malignant activity of the tumor. Radiotherapy, with a dose of 30Gy, is an adjuvant therapy for incompletely resected, or residual tumors.

[Polycystic ovaraian syndrome and hyperinsulinemia]

OBJECTIVE

To identify the relationship between polycystic ovarian syndrome and hyperinsulinemia.

METHODS

Age, body height, body weight, serum estradiol, progesterone, testosterone, follicle stimulating hormone (FSH), luteinizing hormone (LH), prolactin (PRL), triiodothyronine (T3), tetraiodothyronine (T4), insulin, oral glucose tolerance test (OGTT), and cortisol were measured in 28 patients with polycystic ovarian syndrome (PCOS).

RESULTS

Sxiteen patients (57.1% of total) had hyperinsulinemia. Among them one patient was found diabetic. No difference was noted in age, height, body weight, body mass index, serum estradiol, progesterone, testosterone, FSH, LH, PRL, T3, T4, cortisol, and glucose of OGTT between hyperinsulinemia and non-hyperinsulinemia patients. However the LH/FSH ratio (2.4 +/- 1.5) in hyperinsulinemia patients was significantly higher than 1.2 +/- 0.6 in non-hyperinsulinemia patients (P = 0.0125). In addition, the results showed that the fasting serum insulin, insulin after OGTT, the insulin/glucose ratio at 30, 120 minutes, 180 minutes, the area under curve of and the insulin, insulin resistant index (IRI) were higher in hyperinsulinemia pateints than in non-hyperinsulinemia patients respectively. Furthermore, the fasting insulin level, insulin/glucose ratio were found to be negatively related to insulin sensitivity index and positively related with beta-cell functioning index.

CONCLUSION

Hyperinsulinemia and insulin resistance accompany with some of the PCOS patients in China. Further investigations will be necessary to clarify the relevant mechanisms.

Color and power Doppler twinkling artifacts from urinary stones: clinical observations and phantom studies

OBJECTIVE

The purpose of this study was to determine whether color and power Doppler twinkling artifacts could be considered an additional diagnostic sonographic feature of urinary stones.

SUBJECTS AND METHODS

A prospective study was performed in 32 patients with 20 renal stones and 16 ureteral stones to assess how often urinary stones show twinkling artifacts on Doppler sonography. Gray-scale images and color, power, and spectral Doppler images were obtained in all patients. All sonographic examinations were performed with a 3.5- or 5-MHz curvilinear phased array probe. The images were then analyzed for the presence, appearance, and intensity of the artifacts. Phantom experiments were performed with various kinds of urinary stones with high-megahertz linear phased array probes. The effects on the artifacts of the composition of the stones, of the Doppler velocity scale, and of the focal zone were investigated.

RESULTS

Thirty (83%) of 36 urinary stones showed color and power Doppler twinkling artifacts, which appeared as a rapidly changing color complex seen persistently behind stones like a comet's tail. Twenty-two of 30 stones with the twinkling artifacts showed strong intensity artifacts. Spectra with saturated amplitude were obtained from all 30 stones showing color Doppler artifacts. In phantom experiments, the artifacts originated from all stones. The velocity range did not affect the artifacts, whereas focal zone did.

CONCLUSION

Color Doppler twinkling artifacts from urinary stones occur frequently and may be considered an additional sonographic feature of urinary stones. The observation of these artifacts may be helpful in determining the presence of urinary stones.

[The mechanism of percutaneous transluminal balloon angioplasty as assessed by intracoronary ultrasound]

OBJECTIVE

To elucidate the mechanism of coronary balloon angioplasty intracoronary ultrasound imaging.

METHOD

Intracoronary ultrasound imaging was performed in 68 coronary arteries of 52 patients. Ultrasound images obtained at the treatment site before and after balloon angioplasty were analyzed quantitatively for cross-sectional lumen area, area enclosed by internal elastic lamina (IELA) and plaque area. Qualitative analysis included assessment of presence of dissection, plaque composition and plaque topography.

RESULTS

The internal elastic lamina area was significantly enlarged after balloon angioplasty [(6.67 +/- 1.45) mm(2) vs (8.14 +/- 1.13) mm(2), P < 0.05]. The difference between IELA before and after balloon angioplasty DeltaIELA was different among different plaques (fatty plaque 1.84 mm(2), fibrous plaque 1.52 mm(2), calcified plaque 0.40 mm(2), mixed plaque 1.23 mm(2)). 85% of the lesions had dissection in some degree after PTCA. Severe dissections occurred mostly in calcified lesions.

CONCLUSION

The improvement in lumen dimensions after coronary balloon angioplasty is a result of both vessel stretch, as demonstrated by a larger internal elastic lamina area at the treated site, and dissection. Calcified lesions will have less vessel stretch and severer dissection after balloon angioplasty.

[Expression and significance of TGF-beta 1 in nasal polyps]

OBJECTIVE

To study the expression and significance of transforming growth factor-beta 1(TGF-beta 1) in nasal polyps.

METHOD

Expression of TGF-beta 1 in nasal polyps from 34 patients and middle turbinates from 30 patients with deviation of nasal septum were prospectively studied with immunohistochemistry. Each tissue section was observed under optical microscope.

RESULT

1. The TGF-beta 1 positivity in extracellular matrix and in cells in the stroma was significantly higher in nasal polyps than in middle turbinates (P < 0.01). 2. The distribution and shape of TGF-beta 1 expressing cells in nasal polyps was similar to that of eosinophil, their positivities were significantly correlative (P < 0.05). 3. The positivity of TGF-beta 1 did not correlate with clinical type of nasal polyps (P > 0.05), eosinophil infiltration correlated significantly with clinical type of nasal polyps(P < 0.05).

CONCLUSION

1. The TGF-beta 1 may contribute to some of the pathologic changes observed in nasal polyps, such as thickening of the epithelial basement membrane and stromal fibrosis. 2. Eosinophils in nasal polyps represent a major source of TGF-beta 1. 3. Eosinophils infiltration may play a prominent role in the development and recurrence of nasal polyps.

Inhibition of environmental estrogen-induced proliferation of human breast carcinoma MCF-7 cells by flavonoids

In the present study, we evaluated the individual and combined effects of environmental estrogens and flavonoids on the proliferation of human breast carcinoma MCF-7 cells. These compounds are as follows: (1) pharmaceutical chemicals such as diethylstilbestrol, 17alpha-ethynylestradiol (17ES), tamoxifen, mestranol, and clomiphene, (2) industrial chemicals such as bisphenol A (BisA), 4-octylphenol (OP), 4-nonylphenol (NP), and p,p'-biphenol, and (3) flavonoids such as daidzein (D), genistein (G), quercetin (Q), and luteolin (L). We found that nanomolar concentrations of 17ES, BisA, OP, and NP were sufficient to stimulate the proliferation of MCF-7 cells. Among them, 1 microM BisA exhibited cell proliferation-stimulating activity as strong as 10 nM 17beta-estradiol; and D and G exhibited cell proliferation-stimulating activity at 10 nM. On the other hand, Q and L exhibited cell proliferation-inhibiting activity. We also found that 10 nM flavonoids, such as D, G, Q, and L, were able to inhibit the proliferation-stimulating activity in MCF-7 cells by 1 microM environmental estrogens.

[Application of an image-guidance system in endoscopic sinus surgery]

OBJECTIVE

To evaluate the advantages of image-guidance system in endoscopic sinus surgery.

METHODS

Twenty-eight endoscopic sinus surgery procedures were performed with the help of image-guidance system. There were 11 cases of chronic sinusitis with/or without nasal polyps, 4 juvenile nasopharyngeal angiofibromas, 6 pituitary adenomas, 3 ethmoid ossifying fibromas, 2 nasopharyngeal mixed tumors, 1 nasal leiomyoma, 1 fungal sinusitis, and 1 inverted papilloma.

RESULTS

In all cases, the preoperative operation would take 15-30 minutes, the registration rate was 1.3-2.0, the localization accuracy was within 1 mm. Compared with the traditional endoscopic sinus surgery, the operative time did not differ obviously. No complication occurred.

CONCLUSIONS

The image-guidance system could identify the operative borders and critical anatomical structures together with the corresponding CT data, especially in cases with anatomical variations, unidentified anatomical landmarks, and intranasal or anterior skull base tumors. Endoscopic sinus surgery, combined with the image-guidance system, provided accurate tumor resection while preserving normal tissue. It could increase surgical effectiveness and decrease overall surgical complications. We believe that the image-guidance system is a useful tool for endoscopic sinus surgery.

[The effects of streptomycin on the calcium influx in SGCs during depolarization]

OBJECTIVE

To examine the effect of streptomycin on the calcium influx in spiral ganglion cells (SGCs) during depolarization and the differences among different concentrations of streptomycin and SGCs sources with the aim of exploring the mechanism of acute streptomycin ototoxicity.

METHODS

The SGCs of guinea pig cochlea were isolated using an enzyme-machine method and loaded with 10 mumol/L Fluo-3/AM for 30 min at 37 degrees C. Dissociated SGCs loaded with Fluo-3 were examined with a confocal microscope (ACAS Ultima, USA) using a 20 x objective lens and linear scan mean. The fluorescent images collected every 5-sec for a total of 300 sec were stored in a computer. The fluorescent intensity of the images was analyzed by a software cooperated with the confocal microscope, and a curve of fluorescent intensity changes against time was obtained.

RESULTS

The [Ca2+]i of SGCs was steady under the perfusion with standard extracellular solution. The [Ca2+]i of SGCs increased in 12/14 cells under the perfusion with 150 mmol/L high potassium solution, but increased in only 1/10 cells induced by the high potassium calcium free solution. After treating with 1 mmol/L, 0.1 mmol/L, 0.01 mmol/L streptomycin, the [Ca2+]i of the SGCs perfused with the potassium solution was increased in 0/9, 6/14, 7/13 cells, respectively. After the SGCs were treatment with 0.02 mmol/L streptomycin, the [Ca2+]i of the SGCs perfused with the high potassium solution was increased in 5/10 SGCs from the apical turn and in 0/15 SGCs from the basal turn.

CONCLUSION

Perfusion with high potassium media can result in obviously increased [Ca2+]i of the SGCs, and the increase of the [Ca2+]i in the SGCs may originate from the extracellular calcium influx. The calcium influx can be blocked by streptomycin and such effects depend on streptomycin concentrations and SGCs sources.

[Expression of vascular endothelial growth factor and transforming growth factor-beta 1 in nasal polyps]

OBJECTIVE

To study the expression and significance of vascular endothelial growth factor/vascular permeability factor (VEGF/VPF) and transforming growth factor-beta 1(TGF-beta 1) in nasal polyps.

METHODS

Expression of VEGF/VPF and TGF-beta 1 in nasal polyps from 34 patients and middle turbinates from 30 patients with deviation of nasal septum was prospectively studied with immunohistochemistry. Tissue sections were observed under optical microscope.

RESULTS

(1) The VEGF/VPF positivity in vascular endothelium and in glandular cell was significantly higher in nasal polyps than in middle turbinates (P < 0.01 and P < 0.05, respectively); (2) The TGF-beta 1 positivity in extracellular matrix and in cells in the stroma was significantly higher in nasal polyps than in middle turbinates(P < 0.005); (3) The distribution and shape of TGF-beta 1 expressing cells in nasal polyps were similar to that of eosinophil, their positivities were significantly correlative; (4) The positivity of VEGF/VPF and TGF-beta 1 did not correlate with clinical type in nasal polyps (P > 0.05).

CONCLUSION

(1) The VEGF/VPF may play a key role in the formation of heavy edema of nasal polyps; (2) The TGF-beta 1 may contribute to some of the pathologic changes observed in nasal polyps, such as thickening of the epithelial basement membrane and stromal fibrosis; (3) Eosinophils in nasal polyps represent a major source of TGF-beta 1.

[Effect of p14ARF gene on cell growth of human laryngeal tumor cells and expression of endogenous p53 protein]

OBJECTIVE

To explore the inhibitory effect of p14ARF on the cell growth of laryngeal carcinoma and the expression on endogenous p53.

METHODS

p14ARF cDNA was transferred to the cell line Hep-2 of squamous cell carcinoma of the larynx by gene transfer to study the cell cycles and the expression of endogenous wild type p53 using flow cytometry, polymerase chain reaction(PCR) and Western-Blotting.

RESULTS

Expression of p14ARF significantly affected the Hep-2 cell growth. The clone-forming efficiency of the Hep-2 cells transferred with p14ARF was 57%, compared with empty vector pcDNA3. The number of 48 hours after transfer with p14ARF cDNA at both G0/G1 and G2/M was two fold as the control. The expression of endogenous wild type p53 was significantly enhanced.

CONCLUSION

Expression of p14ARF can up-regulate the expression of endogenous wild type p53 and inhibit the Hep-2 cell growth of human laryngeal squamous cell carcinoma at both G0/G1 and G2/M.

[Herpesviridae and laryngeal neoplasia]

OBJECTIVE

To investigate the relationship between herpesviridae and malignant or benign laryngeal diseases.

METHOD

128 paraffin-embedded laryngeal squamous cell carcinoma and laryngeal epithelium hyperplastic lesions were detected by polymerase chain reaction (PCR) and PCR-ISH for herpesviridae.

RESULT

HSV-1 was detected in 10 cases by PCR, among them 3 were laryngeal squamous cell carcinoma (LSCC), 1 was carcinoma in situ(CIS), 4 were laryngeal polyps and 2 were laryngeal keratosis. Except 1 LSCC and 1 CIS 8 of 10 cases were positive while detected by PCR-ISH. In benign diseases, signals were shown from basal layer to superficial cell; in malignant lesions, the signals were scattered in the diseases.

CONCLUSION

Most of laryngeal diseases were not related to herpesviridae, but HSV-1 may acts as initiator in the development of a few cases.

[A multiple-channel system for synchronous acquisition and analysis of neural electrophysiological signals]

The technique for synchronous electrophysiological recording from multiple single cells has been widely applied, but there is still a shortage of suitable data acquisition and analysis systems to fit electrophysiological equipment made in China or Japan. Recently we have developed an acquisition and analysis system for multiple-channel electrophysiological recording. In this paper, we present the pivotal technique of the system and some examples of applications.

[Effects of acute infrasound exposure on vestibular and auditory functions and the ultrastructural changes of inner ear in the guinea pig]

OBJECTIVE

To define the effects of acute infrasound exposure on vestibular and auditory functions and the ultrastructural changes of inner ear in guinea pigs.

METHODS

The animals involved in the study were exposed to 8 Hz infrasound at 135dB SPL for 90 minutes in a reverberant chamber. The sinusoidal pendular test (SPT), auditory brainstem response (ABR) and distortion product otoacoustic emissions (DPOAE) were respectively detected pre-exposure and at 0(within 2 hrs), 2 and 5 day after exposure. The ultrastructures of the inner ear were observed by scanning electron microscopy.

RESULTS

The slow-phase velocity and the frequency of the vestibular nystagmus elicited by sinusoidal pendular test (SPT) declined slightly following infrasound exposure, but the changes were not significant (P > 0.05). No differences in the ABR thresholds, the latencies and the interval peak latencies of I, III, V waves were found between the normal and the experimental groups, and among experimental groups. The amplitudes of DPOAE at any frequency declined remarkably in all experimental groups. The ultrastructures of the inner ear were damaged to different extent.

CONCLUSION

Infrasound could transiently depress the excitability of the vestibular end-organs, decrease the function of OHC in the organ of Corti and cause damage to the inner ear of guinea pigs.

[Anatomic characteristics of lingual artery and midline glossectomy]

OBJECTIVE

To investigate the relationship between anatomic characteristics of lingual artery and midline glossectomy, for the purpose of increasing operative safety.

METHODS

(1) 16 extraoral dissections of the submandibular region were performed on 8 human cadavers and to observe the origin and distribution of lingual artery. (3) The lingual artery was divided into three segments, and the length and adjacent organs were observed and measured.

RESULTS

The whole length of lingual artery was (92.88 +/- 13.53) mm; At points of foramen cecum of the tongue, 5 mm and 10 mm prior to foramen cecum, 10 mm behind foramen cecum, and at adjacent part between root of the tongue and epiglotic vallecula, the distances between lingual artery and midline of the tongue were separately measured. The distances were (11.00 +/- 4.95) mm, (8.56 +/- 3.51) mm, (7.78 +/- 3.15) mm, (13.00 +/- 3.28) mm, (15.22 +/- 3.11) mm. The distances between lingual artery and the surface of tongue were (21.4 +/- 5.59) mm, (22.11 +/- 6.74) mm, (22.56 +/- 7.81) mm, (16.56 +/- 5.57) mm, (2.56 +/- 0.73) mm respectively.

CONCLUSION

During the midline glossectomy, the lingual artery is easier to be damaged at the position where the root of tongue adjoining epiglottic vallecala. The operation should be done within 10 mm below the surface, 7 mm lateral to the midline, to avoid the damage of lingual artery.