Beam power scale-up in micro-electromechanical systems based multi-beam ion accelerators

We report on the development of multi-beam radio frequency (RF) linear ion accelerators that are formed from stacks of low cost wafers and describe the status of beam power scale-up using an array of 112 beams. The total argon ion current extracted from the 112-beamlet extraction column was 0.5 mA. The measured energy gain in each RF gap reached as high as 7.25 keV. We present a path toward using this technology to achieve ion currents >1 mA and ion energies >100 keV for applications in material processing.

New biomarker for lung cancer - focus on circSETD3

In order to explore the mechanism of gefitinib-acquired resistance in lung cancer, a new biomarker has been developed for early clinical diagnosis and intervention; human NSCLC (Non-Small Cell Lung Cancer) cell lines H292 (denoted as H292S) and PC9 (denoted as PC9S) were used to establish gefitinib-resistant NSCLC cell lines H292 and PC9 models. CCK-8 (Cell Counting Kit-8) method was used to test the drug resistance of the cells. circRNAs (circular RNAs) that were differentially expressed before and after resistance were screened by RNA sequencing technology. The effects of circSETD3 overexpression and interference on the sensitivity of gefitinib was observed to analyze the nuclear localization of circSETD3 and verify the interaction between circSETD3-miR-520h-ABCG2. The results showed that the most significant change in differential expression of human NSCLC cell lines before and after drug resistance was hsa_circ_0000567, that is, circSETD3, which is mainly present in the cytoplasm. In H292S and PC9S, compared with the negative control group, the cell proliferation ability of the overexpression group was significantly increased, and the apoptosis ability was significantly decreased. In H292R and PC9R, compared with the negative control group, the proliferation ability of the interference group was significantly decreased, and the apoptosis ability was significantly increased. Overexpression of circSETD3 to H292S and PC9S, the expression of ABCG2 increased significantly. Also, the expression of ABCG2 decreased significantly after transfection with miR-520h mimics. H292R and PC9R interfered with circSETD3, the expression of ABCG2 decreased significantly. Moreover, the expression of ABCG2 increased significantly after transfection with miR-520h inhibitor. In conclusion, circSETD3 can be used as a novel biomarker for lung cancer. It relieves miR-520h degradation of the transporter ABCG2 by down-regulating the miR-520h expression, causing gefitinib to be pumped out of the cell.

Gut-derived acetate promotes B10 cells with antiinflammatory effects

Autoimmune diseases are characterized by a breakdown of immune tolerance partly due to environmental factors. The short-chain fatty acid acetate, derived mostly from gut microbial fermentation of dietary fiber, promotes antiinflammatory Tregs and protects mice from type 1 diabetes, colitis, and allergies. Here, we show that the effects of acetate extend to another important immune subset involved in tolerance, the IL-10-producing regulatory B cells (B10 cells). Acetate directly promoted B10 cell differentiation from mouse B1a cells both in vivo and in vitro. These effects were linked to metabolic changes through the increased production of acetyl-coenzyme A, which fueled the TCA cycle and promoted posttranslational lysine acetylation. Acetate also promoted B10 cells from human blood cells through similar mechanisms. Finally, we identified that dietary fiber supplementation in healthy individuals was associated with increased blood-derived B10 cells. Direct delivery of acetate or indirect delivery via diets or bacteria that produce acetate might be a promising approach to restore B10 cells in noncommunicable diseases.

[Effect of different support angles on the fitness of removable partial denture framework fabricated using selective laser melting technique]

Objective: To evaluate the fitness of bilateral free-end dentition defect removable partial denture framework fabricated by selective laser melting (SLM) technique with different support angles. Methods: After the control group has been set to eliminate the system error, and according to the standard model of bilateral mandibular posterior teeth loss, eighteen titanium alloy removable partial denture frameworks fabricated by SLM technology were divided into 3 groups with support angles of 0° (horizontal group), 45°(45° group) and 90° (vertical group). Plaster cast with duplicated structure of tissue surface of the removable partial denture (RPD) framework was obtained. A three-dimensional scanner was used to scan original and duplicated plaster casts. The gaps between framework and the model in different parts were analyzed using Geomagic Qualify software to evaluate the fitness of the framework with visual method. Results: The framework fits on the plaster model completely, and its tissue surface fitted on the plaster model well. The deviation between frameworks and plaster casts was calculated as follow: the total deviations of the horizontal, 45°, and vertical group were (0.146±0.017), (0.182±0.015) and (0.185±0.022) mm respectively. The mean deviation of the horizontal group was significantly less than those of the 45° group and the vertical group (P<0.05). Moreover, there was no significant difference in the total deviation between the 45° group and the vertical group. The total deviation of occlusal rest of the horizontal group was significantly less than that of the 45° group (P<0.05). However, no significant difference was detected in the deviation of occlusal rest among the vertical group, the horizontal group, and the 45° group (P>0.05). There was no significant difference in the deviation of occlusal rest among the vertical group, the horizontal group, and the 45° group. The deviation of clasp of the horizontal group was significantly smaller than those of the 45° group and the vertical group (P<0.05). Whereas, there was no significant difference in the deviation of clasp between the 45° group and the 90° group (P>0.05). No significant difference was found in the deviation of lingual bar among the three groups (P>0.05). Conclusions: Among the three kinds of bilateral free-end dentition defect RPD framework fabricated by SLM in different support angles, horizontal printing was proved to reach the minimal deviation, even though the fitness of all three kinds of frameworks can fullfil clinical requirements according to previous studies.

Gemcitabine and cisplatin for treatment of lung cancer in vitro and vivo

OBJECTIVE

To evaluate the antitumor activity of gemcitabine (GEM), cisplatin (DDP) as well as the combination of these two agents in lung cancer cells and mice.

MATERIALS AND METHODS

The cell viability was evaluated by the CCK-8 assay. Cell apoptosis was measured by flow cytometry assay and Hoechst staining. The protein expression of VEGF, VEGFR2, Ang II, AT1R, and ACE2 was examined by Western blotting. The effect of GEM and DDP on tumor growth and survival time was also measured in lung cancer mice in vivo.

RESULTS

The results revealed that alone or combined administration of GEM and DDP could inhibit the growth, induce apoptosis and apoptotic body formation of A549 cells compared with control cells, with the most significance detected in a combination of GEM and DDP administration. It is indicated that combined administration of GEM and DDP could delay the progress of tumor formation in nude mice. The cell apoptosis- and angiogenesis-related proteins expressions were decreased both in A549 cells and lung cancer mice.

CONCLUSIONS

GEM plus DDP can be an option for patients with lung cancer treatment. However, further prospective evaluation and randomized trials are to provide more accurate information through clinical trials.

A diabetes scorecard does not improve HbA(1c), blood pressure, lipids, aspirin usage, exercise and diabetes knowledge over 9 months: a randomized controlled trial

AIMS

To test (1) whether a diabetes scorecard can improve glycaemic control, blood pressure control, LDL cholesterol, aspirin usage and exercise; (2) if the scorecard will motivate and/or educate patients to improve their scores for subsequent visits; and (3) whether the scorecard will improve rates of clinical inertia.

METHODS

Five physicians enrolled 103 patients ≥ 40 years old with uncontrolled Type 2 diabetes [HbA(1c) ≥ 64 mmol/mol (8.0%)] to randomly receive either a diabetes scorecard or not during four clinical visits over a 9-month period. The population was predominantly urban with a disproportionately higher percentage of black people than the general population. Our scorecard assigned points to six clinical variables, with a perfect total score of 100 points corresponding to meeting all targets. The primary outcomes were total scores and HbA(1c) in the scorecard and control groups at 9 months.

RESULTS

There were no significant differences between the control and scorecard groups at visits 1 and 4 in total score, HbA(1c) , blood pressure, LDL cholesterol, aspirin usage, exercise or knowledge about diabetic targets. By visit 4 both the control and scorecard groups had statistically significant improvements with their mean total score (9 and 7 points, respectively), HbA(1c) [-9 mmol/mol (-0.8%) and -15 mmol/mol (-1.4%), respectively] and aspirin usage (33% increase and 16% increase, respectively). Rates of clinical inertia were low throughout the study.

CONCLUSIONS

A diabetes scorecard did not improve glycaemic control, blood pressure control, LDL cholesterol, aspirin usage, exercise or diabetic knowledge in an urban population with uncontrolled Type 2 diabetes.

Downregulation of autophagy by Bcl-2 promotes MCF7 breast cancer cell growth independent of its inhibition of apoptosis

The anti-apoptotic Bcl-2 protein, which confers oncogenic transformation and drug resistance in most human cancers, including breast cancer, has recently been shown to effectively counteract autophagy by directly targeting Beclin1, an essential autophagy mediator and tumor suppressor. However, it remains unknown whether autophagy inhibition contributes to Bcl-2-mediated oncogenesis. Here, by using a loss-of-function mutagenesis study, we show that Bcl-2-mediated antagonism of autophagy has a critical role in enhancing the tumorigenic properties of MCF7 breast cancer cells independent of its anti-apoptosis activity. A Bcl-2 mutant defective in apoptosis inhibition but competent for autophagy suppression promotes MCF7 breast cancer cell growth in vitro and in vivo as efficiently as wild-type Bcl-2. The growth-promoting activity of this Bcl-2 mutant is strongly correlated with its suppression of Beclin1-dependent autophagy, leading to sustained p62 expression and increased DNA damage in xenograft tumors, which may directly contribute to tumorigenesis. Thus, the anti-autophagic property of Bcl-2 is a key feature of Bcl-2-mediated oncogenesis and may in some contexts, serve as an attractive target for breast and other cancer therapies.

COPD in Chinese nonsmokers

Little is known about chronic obstructive pulmonary disease (COPD) in Chinese nonsmokers. The present study aimed to investigate the profiles of COPD among nonsmokers based on the Chinese Epidemiological Survey of COPD (CESCOPD). In the CESCOPD, 20,245 subjects aged 40 yrs or older were interviewed with questionnaires and spirometry tests. Subjects with a post-bronchodilator forced expiratory volume in one second (FEV(1))/forced vital capacity (FVC) ratio of <0.70 were identified as having COPD. Data of 12,471 nonsmokers and 1,024 smoking COPD patients were analysed in the current study. The overall prevalence of COPD among nonsmokers was 5.2% (95% confidence interval 4.8-5.6). Being male, of advanced age, lower body mass index (BMI) and lower educational level, having exposure to environmental tobacco smoke, coal and/or biomass smoke, poor ventilation in the kitchen, a family history of respiratory disease and recurrent childhood cough were all independently associated with a higher risk of having COPD among nonsmokers. Nonsmokers with respiratory symptoms without airflow limitation showed a somewhat different pattern of risk factors. Nonsmokers with COPD were less likely to present with chronic productive coughs and lower BMI, while more likely to have received a physician diagnosis of asthma and respiratory diseases in childhood, than smokers with COPD. Chronic obstructive pulmonary disease is prevalent among Chinese nonsmokers, and nonsmoking chronic obstructive pulmonary disease may have different profiles from smoking chronic obstructive pulmonary disease.

[Neurological manifestations of isolated sphenoiditis]

OBJECTIVE

To review the neurological manifestations of isolated sphenoiditis.

METHODS

The symptoms, signs, imaging data, diagnoses and outcomes of 14 cases with sphenoiditis hospitalized in Peking Union Hospital June 1995-January 2001 were analyzed retrospectively.

RESULTS

The chief complaints of this group included headache (12 cases), visual loss and/or diplopia (7 cases), blood in nasal discharge (3 cases), purulent nasal discharge (2 cases), exophthalmoptosis (1 case), fixation of eyeball (1 case), and pharyngodynia (1 case). Six patients presented deficits of the second and/or third, fourth, and sixth cranial nerves; one patient had hemiplegia and aphasia; no more presentation of nervous system was found in all patients. Only five patients showed signs of posterior sinusitis in rhinologic examination. CT and/or MRI revealed isolated sphenoiditis (11 cases) and sphenoiditis with posterior ethmoiditis (3 cases). The complications of this group were intracranial infection involving frontal, temporal, and parietal lobes and brainstem (1 case), aneurysm of cavernous carotid artery (1 case), nasal cerebrospinal fluid leakage (1 case), optic neuritis (5 eyes), abducent paralysis (2 cases), orbital cellulitis (1 case) and orbital apex syndrome (1 case). All of the patients underwent endoscopic sphenoid surgery. 13 patients were free of headache after surgery. One patient died because of hernia of brain.

CONCLUSION

Headache can be the first or unique symptom of isolated sphenoiditis. Isolated sphenoiditis should be considered in diagnosis and differential diagnosis of headache. CT and MRI are the best tools in diagnosis of isolated sphenoiditis.

[Study of pharyngo-cutaneous fistula after total laryngectomy]

OBJECTIVE

To explore the factors which lead to pharyngo-cutaneous fistula after total laryngectomy.

METHOD

A retrospective study of 125 patients who underwent total laryngectomy during a 16-year period was carried out.

RESULT

The rate of post-laryngectomy pharyngo-cutaneous fistula is 16.0% (20/125), it appears reduced tendency. With single-factor analysis, the factors effect on the rate of post-laryngectomy pharyngo-cutaneous fistula include clinical tumor stage, tumor types, pre-operative radiotherapy dose, intraoperative blood transfusion, operative duration. With all variable logistic model analysis, the factors effect on the rate of pharyngo-cutaneous fistula are clinical tumor stage and pre-operative radiotherapy dose, but pre-operative radiotherapy is very possible to be a risk factor (P = 0.0566). With logistic model stepwise regression analysis, the factors effect on the rate of pharyngo-cutaneous fistula are clinical tumor stage and operative duration.

CONCLUSION

Pharyngo-cutaneous fistula appears easily in patients with T3, T4 tumor, and have pre-operative radiotherapy, especially have large dose preradiotherapy. For these high risk patients, the duration of operation should be as short as possible to reduce the rate of post-laryngectomy pharyngo-cutaneous fistula.

IFN-alpha1a gene is the major variant in the North American population

Thirteen interferon (IFN)-alpha functional genes have been reported. A number of these genes have allelic members (variants). In the case of IFN-alpha1, two variants, IFN-alpha1a and IFN-alpha1b, are known. The variants differ from each other by one base change in the coding region, leading to a single change in amino acid sequence and the presence of a restriction site. We have developed oligonucleotide primers for amplification of IFN-alpha1 gene(s) using polymerase chain reaction (PCR). Genomic DNA, obtained from over 23,000 normal healthy individuals and from four human cell lines, were used as templates in PCR to amplify the IFN-alpha1 gene sequences. The resulting PCR products were analyzed by restriction endonuclease digestion and DNA sequencing to identify the presence of variant sequences. The results show that IFN-alpha1a is predominant in the genomic DNA of the population examined. Among the cell lines studied, IFN-alpha1a is the only variant found in U-937 and Namalwa cells, whereas KG-1 cells have only IFN-alpha1b, and EB-3 cells have both IFN-alpha1a and IFN-alpha1b in the genome.

[Alteration of free radical generation in pulmonary tissue after quick decompression]

The purpose of this experiment was to evaluate decompression-induced pulmonary injury by means of measurement of ascorbate free radical (Vc-.) alteration in pulmonary tissue of the rats which experienced rapid decompression. 29 male S-D rats were divided into 4 groups: A was executed at 45 min post-decompression; B was control for A; C was executed at 90 min; D was ontrol for C. Group A and group C were to compress up to 0.5 MPa(air) and stay for 60 min, then were decompressed smoothly to normbaric in 1 min. The 0.05 M N-tert-butyl-alpha-phenylnitrone (PBN) was given at 20 min after completion of decompression (groups A and B) or at 65 min (groups C and D). At 25 min after PBN injection the animals were killed by cutting arteria coeliaca, and 0.75 g pulmonary tissues were taken. These tissues were homogenized for electron paramagnetic resonance (EPR) assay. The results demonstrated that the ascorbate free radical (Vc-.) signals were obtained at all samples. The intensity of signals measured in group C rose markedly (P < 0.05) and that in group A was close to control's. So it can be concluded that rapid decompression would increase the generation of free radical in lung.

[Olfactory evoked potentials produced by electrical stimulation of the olfactory mucosa]

OBJECTIVE

To develop an objective olfactometric method.

METHODS

Electrically evoked olfactory potentials were recorded in 20 rabbits with 0.2-4.0 mA electrical stimulations. The stimulating electrodes were placed on the olfactory and respiratory regions of the nasal mucosa. Recording electrode was placed on the scalp near the olfactory bulb.

RESULTS

Electrically evoked olfactory potentials composed of triphasic negative-positive-negative peaks, named N1, P1, N2 respectively, were detected on the olfactory region. The latencies of N1, P1, N2 were 16.27 ms, 25.36 ms, 49.75 ms respectively in cribriform plate. No electrically evoked potentials were detected on the respiratory mucosa, nor did on the olfactory mucosa after olfactory neurectomy.

CONCLUSION

Steady and clear electrically evoked olfactory potentials which originated from olfactory neurosystem were detected on olfactory mucosa in rabbits.

[Vestibular potentials evoked by electrical stimulation]

OBJECTIVE

To identify the evoked potentials (VsEPs) by electrical stimulation were from vestibule.

METHODS

The stimulating electrode was set on the round window of guinea pig. Constant current shocks of 0.05 ms (0.25-1.2 mA) were used to evoke VsEPs by means of vertex-pinna skin electrodes.

RESULTS

These potentials were short latencies of (0.973 +/- 0.086) ms, (1.618 +/- 0.176) ms and (2.416 +/- 0.274) ms respectively, which reflected true potentials and were not from electrical stimulus artefacts. It was pure vestibular origin. As being masked with a continuous white noise (120 dB SPL) or removed ipsilateral auditory nerve, and even after facial neurectomy, waves were still existing, but disapeared after selective vestibular neurectomy. The twitching responses in the facial region had never been detected during the whole test. These potentials were bioelectric responses in the vestibular sensory pathway, characterized by threshold saturation, adaptability of excitation, dependent on intact vestibular nerve.

CONCLUSIONS

We have set up animal model of recording VsEPs evoked by electrical stimulation on the round window of guinea pigs.

[Audiologic analysis of a family with nonsyndromic genetic progressive sensorineural hearing loss]

OBJECTIVE

To analyze the audiological data collected from a large six-generation family with nonsyndromic genetic progressive sensorineural hearing loss.

METHODS

There were 104 members in the family who could provide the hearing data, in which 46 individuals had hearing impairment. The pure tone threshold in 56 individuals and ABR in 49 individuals were analyzed. The pedigree of 104 family members with 6 branches was made.

RESULTS

Hearing impairment was found in the second decade. The hearing thresholds of high and mid frequencies were deteriorated up to 110 dB HL in the fourth decade. The hearing loss started from high frequencies and quickly expended to mid and low frequencies. The regression analysis of pure tone thresholds of 4 kHz and 8 kHz in 6 cases with ages from 10 to 20 years were carried out. The regression coefficients, or the annual threshold increases were 15.96 dB and 15.34 dB per year, respectively. ABR results showed that the hearing loss was caused by cochlear impairment. The pedigree of family indicated high or complete penetrance.

CONCLUSION

The medical history and audiological analysis of the family members showed that this hearing impairment was nonsyndromic autosomal dominant progressive sensorineural hearing loss. The hearing impairment and onset age in this family were different from those families with 13 loci related autosomal dominant nonsyndromic sensorineural hearing loss reported previously. The genetic linkage study showed that it could not link to these regions and other two regions reported recently in Internet.

Suppressing effect of substance P receptor antagonist on sound evoked potentials recorded from the guinea pig cochlea

OBJECTIVE

To investigate the regulation of SP in the cochlea function.

METHODS

Ten adult guinea pigs were used as experimental animals. The perilymph space of the guinea pigs cochlea was perfused with artificial perilymph solution containing 1 microgram/microliter SP receptor antagonist (D-Arg1, D-Pro2, D-Trp7,9, Leu11)-SP (1-11) at a rate of 2.5 microliters/min for 10 min while monitoring cochlear potentials evoked by 4 kHz tone burst.

RESULTS

The perfusion of SP antagonist resulted in a suppression of the compound action potential of the auditory nerve (CAP, N1-P1), a prolongation of the N1 latency at threshold and suprathreshold levels, an elevation of the CAP threshold.

CONCLUSIONS

These results suggest that SP might play a role as a transmitter or modulator in the cochlear function.

[Pharyngoscopic observation during sleep in patients with obstructive sleep apnea syndrome]

OBJECTIVE

To analyse collapse sites of pharynx and their anatomical causes during sleep in patients with obstructive sleep apnea syndrome(OSAS), and compared with the results of Muller's maneuver.

METHODS

The pharynges in 43 sleeping patients with OSAS were examined endoscopically. The area changes at each segment(velo-, oro- and hypopharynges) were calculated during the episodes of apnea. A site having greater than 75% narrowing of airway lumen was defined as a narrowing or obstructive site.

RESULTS

1. All patients had obstruction at velopharynx during asleep. Airway collapses at multiple sites in 79% of cases(28% at velo- and oropharynx; 21% at velo- and hypopharynges; and 30% at velo-, oro- and hypopharynges). 2. At each segment the anatomical factors causing obstruction were variable among patients. The common abnormalities were posterior displacement of soft palate or uvula, enlarged tonsil, thicken or posterior displacement of tongue base, collapse of pharyngeal wall, redundant mucosa or lateral bands of pharynx etc. 3. The positivity of pharyngeal obstruction was higher in this study as compared with of Muller's maneuver the latter was taken place while the patient was awaken. Comparison of the positive rate of the narrowing sites determined between sleep observation and Muller's maneuver in same patients: at velopharynx(100% vs 91%), at oropharynx (58% vs 42%) and at hyperpharynx (51% vs 28%).

CONCLUSION

Multiple obstructions in the pharynx are common. Examination of the pharynx during asleep may be more accurate then while the patient was awaken.

[The normal value and clinical applications of the blink reflex]

OBJECTIVE

To study the normal value and clinical applications of blink reflex.

METHODS

Using the clinical electrodiagnostic techniques, the orbital nerve was stimulated to elicit the blink reflex.

RESULTS

In 20(40 sides) normal subjects, two components (R1 and R2) had been documented. The latencies were about 10.1 ms for R1, 30.4 ms and 30.7 ms separately for R2 and R2'. In 30 patients with trigeminal and facial nerve diseases and acoustic neuromas, the latencies on the affected sides were apparently longer or the reflex disappeared (P < 0.01).

CONCLUSION

This study indicates that the simple, harmless electrodiagnostic measurements are of value in the initial investigation of trigeminal and facial nerve diseases and acoustic neuroma.

[The diagnosis and treatment of cerebrospinal fluid rhinorrhea]

OBJECTIVE

To summarize our experience in managing cerebrospinal fluid(CSF) rhinorrhea.

METHODS

Twenty-nine cases with cerebrospinal fluid rhinorrhea from 1982 to March of 1997 were reviewed. The duration of CSF rhinorrhea varied from 3 months to 23 years. The ages of the patients ranged from 7 to 72 years.

RESULTS

The causes of CSF leak were spontaneous in 18 cases, traumatic in 6 (1 had two accidents and got two different leaking sites) and iatrogenic in 5 cases. Twenty-two cases underwent surgical repair. Overall closure rate was 81.8%. The causes, symptoms and signs, sites of leakage and surgical techniques were analyzed. The classification, diagnosis and treatment of CSF rhinorrhea were discussed.

CONCLUSION

Transnasal extracranial repair undertaken by otorhinolaryngologist got better closure rate(93.8%) in this group. Transnasal endoscopic repair could afford excellent view, facilitate precise tissue graft placement and get better closure rate.

[The diagnosis of non-pituitary space-occupied lesions in sphenoidal sinus and sellar area]

OBJECTIVE

To improve the diagnostic accuracy of non-pituitary lesions in sphenoidal sinus and sellar area.

METHODS

Twenty-four cases with non-pituitary lesions in sphenoidal sinus and sellar area were analyzed. Eighteen cases were benign, including 7 sphenoidal sinus cyst, 6 craniopharyngioma, 2 chordoma, 1 nasal polyp extending into the sella, 1 neuronoma in sella, and 1 pinealoma. Six cases were malignant, including 2 malignant neuroendocrinoma in sphenoidal sinus, 1 adenoidocystic carcinoma, 1 sphenoidal sinus low differentiated carcinoma, 1 nasopharyngeal carcinoma extending into sella, 1 lung cancer metastasis to sphenoidal sinus. Clinical presentation, examination, imaging study, diagnosis and treatment were discussed.

RESULTS

Among 24 cases, 18 had headache, 17 had visual symptoms. In all cases the space-occupied lesions in sphenoidal sinus and sellar area were verified by CT scan.

CONCLUSIONS

1. Headache at different levels was the commonest symptom for benign and malignant lesions. The visual loss was another common symptom. It is important to realize the relationship between visual symptom and space-occupied lesions in sphenoidal sinus and sellar area; 2. Imaging study is very important for the diagnosis of the lesions in sphenoidal sinus and sellar area; 3. It is helpful to do needle-aspirating biopsy under endoscopy to confirm the pathologic diagnosis. The benign lesions were operated on, and malignant lesions were treated by combined operation and radiation.

[The effection of obstructing OCB with strychnine on the guinea pig's DPOAE]

The strychnine was used to obstruct the oliver cochlear bundle (OCB) in order to explore the effect of the efferent system on distortion product otoacoustic emission (DPOAE) of guinea pig. The result showed that the DPOAE were not changed after strychnine were administrated. It is concluded that the efferent pulses of the CNS does not affect on DPOAE in silent circumstance.

A new allele of interferon-alpha17 gene encoding IFN-alpha17b is the major variant in human population

Thirteen interferon (IFN)-alpha functional genes have been reported. Among these, a number of genes have allelic members (variants). In the case of IFN-alpha17, five variants, IFN-alpha17a, IFN-alpha17b, IFN-alpha17c, IFN-alpha17d, and IFN-alphaT, are known. The variants differ from each other by base changes in the coding region, leading to differences in amino acid sequences. We have developed oligonucleotide primers for amplification of IFN-alpha17 gene(s) using polymerase chain reaction (PCR). Genomic DNA, obtained from over 28,000 normal healthy individuals and from four cell lines, were used as templates in PCR to amplify the IFN-alpha17 gene sequences. The resulting PCR products were analyzed by restriction endonuclease digestion and DNA sequencing to identify the presence of variant sequences. The results show that a new variant of IFN-alpha17 is abundantly present (approximately 70%) along with another variant, possibly IFN-alpha17c (approximately 30%), in the genomic DNA of the population examined. This new variant, the protein product of which is identical to IFN-alpha17b, differs from the gene for IFN-alpha17b by a point mutation. We have named it IFN-alpha17b', which is the only variant found in U-937, KG-1, and EB-3 cell lines. Namalwa cells have IFN-alpha17b' and, possibly, IFN-alpha17c in equal proportions.

[Distortion product otoacoustic emissions in normally hearing young humans]

OBJECTIVE

To investigate the basic properties of distortion product otoacoustic emissions (DPOAE) in normally hearing subjects of China.

METHODS

DPOAE "audiogram" (DP-gram) and input/output functions (I/O functions) were recorded from 24 normally hearing young humans with Celesta-503 cochlear emissions analyzer.

RESULTS

The prevalence of DPOAE was 100% ranging in frequency from 500 to 8,000 Hz, with respect to the geometric means of f1 and f2 stimuli. The mean DP-gram had two peaks at about 1,000 Hz and 6,000 Hz and a dip at about 3,000 Hz. The higher amplitude of DPOAE was recorded at about 3,000 Hz when using unequal primary-tone levels (L1 > L2). The mean thresholds of DPOAE were between 25 and 40 dB SPL. The thresholds of DPOAE decreased with increasing primary-tone frequencies. The I/O slopes were higher at about peak freqencies than at other frequencies. For all the results of DPOAE in left and right ears, there were no apparent differences by statistics.

CONCLUSIONS

By systematical studies of the properties of DPOAE in normally hearing ears of Chinese subjects, this paper provides basic reference data for clinical application of DPOAE.

Action of antitumoral platinum complexes on in vitro platelet functions

This report presents a comparison of the effects of cis- and trans-diamminedichloroplatinum complexes on in vitro platelet functions. Pretreatment of platelets with cis-platinum (cisplatin) induced a slow, dose-dependent (0.1-0.45 mM), increase in the cytosolic Ca2+ concentration, pleckstrin (47 kDa) phosphorylation and serotonin secretion, as well as a slight shape modification with emission of a few pseudopodia. All these effects were remarkably increased in platelets exposed to trans-platinum (transplatin). The rise in cytosolic Ca2+ concentration and serotonin secretion evoked by stimulation of platelets with thrombin were not significantly influenced by cellular exposure to cis-platinum, whereas they were enhanced and inhibited, respectively, by exposure to trans-platinum. Trans-platinum also inhibited thrombin-promoted platelet aggregation to a greater extent than the cis-isomer. While the viscosity of platelet rich-plasma tended to decrease in the presence of cis-platinum, it tended to increase in the presence of trans-platinum. Taken together, these results indicate that the effects on platelet functions of the efficacious antitumor complex cis-platinum is rather different from that of the inactive complex trans-platinum. Therefore, the in vitro tests of platelet functions employed in this study might provide an index of antitumor drug toxicity and serve as a preliminary indicator of therapeutic efficacy.

[Preoperative nasal continuous positive airway pressure treatment as substitute for protective tracheostomy in severe obstructive sleep apnea syndrome]

OBJECTIVE

Preoperative nasal continuous positive airway pressure(NCPAP) treatment was used as a substitute for protective tracheostomy before UPPP surgery in 42 patients with severe obstructive sleep apnea syndrome(OSAS) from 1994 to 1996.

METHODS

Fifty-two patients operated on three years before this period served as control group. All cases were diagnosed as severe OSAS by polysomnography (PSC).

RESULTS

There were no statistical difference in main parameters between two groups. Seven cases in the control group underwent protective tracheostomy whose apnea and hypopnea index(AHI) was 28.4-83.5 and lowest saturation oxygen (SaO2) were 7%-32%. One patient underwent emergency tracheostomy due to life-threatening situation during uvulopalatopharyngoplasty (UPPP). There were 9 similarly severe cases who did not undergo protective tracheostomy in NCPAP treatment group. All patients underwent preoperative 5-20 day NCPAP treatment in treatment group. The average positive pressure was 1.16 kPa(11.85 cmH2O). There were significant difference in main parameters between the two groups. The AHI, SaO2 and sleep structure were evidently improved. UPPP was safely performed without protective tracheostomy and any complications in all patients with NCPAP treatment.

CONCLUSION

This result implys that NCPAP treatment could be used as a substitute for protective tracheostomy before UPPP in severe OSAS.

[Effect of monaural cochlear ablation on cell areas of ventral cochlear nucleus neurons in neonatal and adult guinea pigs]

The changes of the cross-sectional areas of anteroventral cochlear nucleus (AVCN) and posteroventral cochlear nucleus (PVCN) were studied in neonatal and adult guinea pigs after monaural cochlear ablation with computer imaging analysis system. The cross-sectional areas of neurons in AVCN and PVCN were not significantly changed after 24 h of monaural cochlear ablation in neonatal guinea pigs. But the cell areas of AVCN neurons of ablated side were respectively reduced by 20.93%, 25.70% and 28.72% compared to non-ablated side in 4 d, 7 d, 60 d after cochlear ablation, the cell areas of PVCN neurons were reduced by 17.58%, 20.30% and 38.55% respectively. The area reduction of AVCN and PVCN neurons of ablated side in 60 d group with monaural cochlear ablation were 51.00% and 32.75% relative to normal control group. Our results showed that cochlear ablation could results in rapid cell area reduction of VCN neurons in guinea pigs. Our investigation implied that it is important to stimulate the auditory nerve early in the patients with hearing loss.

[Employing deconvolution method for correcting scatter in radiography]

It is well known that the scattered-radiation (SR) results in degradation of the images contrast in digital X-ray radiograph. The main reason affecting radiographic image quality is the SR arising from interaction of the photons with object being radiographed and veiling glare from detector system in the II-TV chai imaging system. With the aim of improving the image quality, we employed the Gaussian function to approximate the scattered point spread function (PSF) and determined the fraction of SR, rho and the parameter, sigma experimentally on an individual system; then we built an inverse filter to process the digital chest X-ray images, which were acquired with the same system and transformed in 2-D Fourier tansform operation. The images processed were corrected by using a variable weihting factor and the resulting images are shown in this paper. The method provides a useful way for solving the problem of correction of the SR in digital X-ray images.

A disease-related rheumatoid factor autoantibody is not tolerized in a normal mouse: implications for the origins of autoantibodies in autoimmune disease

We have analyzed B cell tolerance in a rheumatoid factor (RF) transgenic mouse model. The model is based on AM14, a hybridoma, originally isolated from an autoimmune MRL/lpr mouse that has an affinity and specificity typical of disease-related RFs from this strain. AM14 binds to immunoglobulin (Ig)G2a of the "a" allotype (IgG2aa) and not to IgG2ab. Thus, by crossing the transgenes onto an IgHa (BALB/c) background or to a congenic IgHb (CB.17) background, we could study the RF-expressing B cells when they were self-specific (IgHa) or when they were not self-specific (IgHb). These features make the AM14 model unique in focusing on a true autoantibody specificity while at the same time allowing comparison of autoreactive and nonautoreactive transgenic B cells, as was possible in model autoantibody systems such as anti-hen egg lysozyme. Studies showed that AM14 RF B cells can make primary immune responses and do not downregulate sIgM, indicating that the presence of self-antigen does not induce anergy of these cells. In fact, IgHa AM14 transgenic mice have higher serum levels of transgene-encoded RF than their IgHb counterparts, suggesting that self-antigen-specific activation occurs even in the normal mouse background. Since AM14 B cells made primary responses, we had the opportunity to test for potential blocks to self-reactive cells entering the memory compartment. We did not find evidence of this, as AM14 B cells made secondary immune responses as well. These data demonstrate that a precursor of a disease-specific autoantibody can be present in the preimmune repertoire and functional even to the point of memory cell development of normal mice. Therefore, immunoregulatory mechanisms that normally prevent autoantibody production must exert their effects later in B cell development or through T cell tolerance. Conversely, the data suggest that it is not necessary to break central tolerance, even in an autoimmune mouse, to generate pathologic, disease-associated autoantibodies.

[Role of area postrema on DOCA-salt induced hypertension in rat]

OBJECTIVE

To determine the effect of area postrema AP on DOCA-salt induced hypertension in rat, with emphasis on renal hemodynamics.

METHOD

Blood pressure, salt and water balances and renal hemodynamics were observed in AP ablated and sham-operated rats treated with DOCA-salt.

RESULTS

In AP intact (API) rats, after one week of DOCA-salt treatment BP began elevating to statistical significance at the end of the second week (MAP 15.9 +/- 0.7 vs. 13.5 +/- 0.5 kPa), followed by a plateau period from the third to fifth week. In AP ablated (APX) rats, BP raised during the first week of DOCA-salt treatment. However, the elevation gradually disappeared and BP returned to baseline at the fifth week. Sodium balance study showed that DOCA-salt treatment induced significant sodium retention in API rat, while the sodium metabolism remained stable in APX group except in the first week. Basal renal hemodynamic parameters (GFR, RPF, UNaV, UV) were not changed at neither the beginning nor the end of the study. However, a small dose of hypertonic saline (7% NaCl 0.3 ml) injection caused a brisk rising of these four parameters in APX but not API group.

CONCLUSION

AP plays an important role in normal salt and water metabolism and might be involved in pathogenesis of DOCA-salt hypertension through regulation for renal hemodynamics and body fluid homeostasis.

[The analysis of abnormal auditory brainstem responses]

The abnormal auditory brainstem responses (ABR) of 56 cases who had different retrocochlear disorders were analysed. These disease included acoustic neuroma, glioma, cholesteatoma, astrocytoma, meningoma in cerebellopontile angle (CPA), chromaffin tumor of jugular foramen, intracranial metastatic tumor, demyelinating disease, multiple cranial nerve paralysis, hepatolenticular degeneration, other CPA tumors, expansion or stenosis of internal auditory meatus (IAM), and so on. The ABR features were varied in these diseases, even in same disease. In general, the wave latencies and interwave periods prolonged in the disorders which occupied place in CPA, the differentiation of wave was not clear and/or the wave was not well repeated in the disorders which spreaded all over the brain. The cause of abnormal ABRin which CT and/or MRI were normal was also analysed. The ABR detection is a sensitive indication in retrocochlear lesions.

Determination of platinum in human blood using inductively coupled plasma atomic emission spectrometry with an ultrasonic nebulizer

A rapid and accurate method for the determination of platinum in human plasma by using inductively coupled plasma atomic emission spectrometry with an ultrasonic nebulizer is proposed. The emission lines at 214.423 and 265.945 nm were investigated showing that the 214.423 nm line is the most sensitive and reliable for measuring platinum concentrations of as little as 20 micrograms l-1 (ppb) in biological materials. Microwave digestion for mineralizing human blood sample matrices was used and the possible influence of the concentration of HNO3 on platinum emission lines was investigated. Finally, the platinum concentration was determined in whole human blood, in platelets and in other blood components. Two equivalent methods for the isolation of protein from the platelet-poor plasma were investigated. The proposed method offers relative simplicity of sample pre-treatment and lends itself to various routine biological studies.

[An experimental study of middle ear implantable hearing device]

The partially middle ear implantable hearing device was designed and tested in 7 cats with conductive hearing loss and 5 cats with mixed hearing loss. It was composed of sound processor, connector and ossicular vibrator. The ossicular vibrator was made from piezoelectric ceramic bimorph which was constructed in the form of flat chip 6mm in length, 1mm in width and 0.5mm in thickness. The incus of cat was removed and the lip attachment of the vibrator was attached to the head of the stapes. The base of the vibrator was fixed to the bone wall of bulla with medical glue. The average values of the response threshold of ABR evoked by click via this vibrator got reduction of 37dB and 39dB respectively in conductive hearing loss group and mixed hearing loss group. The gain curve of hearing was flat in the range from 0.5 to 8kHz frequencies. The ABRs evoked by click via ossicular vibrator was similar to that recorded preoperatively in the wave shape. This result indicates that this device is a highly efficient sound conducting divice to inner ear.

Interferon-alpha 2 variants in the human genome

Variants of human leukocyte interferon alpha 2 (IFN-alpha 2a, alpha 2b, and alpha 2c) differ from each other by changes in their coding regions at nucleotide positions 137 and 170. As a result of these nucleotide variations, the DNA sequences of the three variants can be distinguished by selective restriction enzyme analysis. Human genomic DNA obtained from over 28,000 normal healthy individuals was used as templates in the polymerase chain reaction (PCR) to amplify the human IFN-alpha 2 gene sequence. The resulting PCR products were analyzed with restriction nucleases to identify the specific IFN-alpha 2 variant sequences present in the genomic DNA of the population examined. The results show that IFN-alpha 2b was detected as the predominant species and IFN-alpha 2c as a very minor species (< 0.1%). The IFN-alpha 2a gene was not detected in this population.

The role of B cells in lpr/lpr-induced autoimmunity

The primary roles of T cells and B cells in the initiation of systemic autoimmunity are unclear. To investigate the role of B cells, we crossed the "Jh knockout" mutation onto the autoimmune lpr/lpr background. Animals homozygous for both traits were obtained. As expected, these animals lack B cells. These animals also show no signs of autoimmune kidney destruction nor vasculitis, in spite of carrying the lpr/lpr mutation. In contrast, lpr/lpr littermates that had B cells had severe nephritis and vasculitis, as well as autoantibodies. These results demonstrate a primary role for B cells and/or (auto)antibodies in initiating several types of autoimmune-mediated tissue destruction. The implications of this finding for models and therapy of autoimmunity are discussed.

[Cochlear histopathological changes following chronic extracochlear electrical stimulation in kittens]

Histopathological investigation of the cochlea following chronic extracochlear electrical stimulation was carried out in 5 kittens. The auditory nerves were electrically stimulated with round window or tympanic promontory electrodes for periods of 1276-1526 h using charge-balanced biphasic current pulses at charge densities of 1.27-5.73 microC/cm2. geom. phase. The histopathological changes were examined with a light microscope. The findings were as follow: 1. The fixations of round window and tympanic promontory electrodes were very firm. Six round window membranes became thicker in the area which contacted the electrode. One was pushed into the scala tympani and adhered to the spiral lamina of the hook region. 2. There was some outer hair cell loss, mild inner hair cell loss and disappearance of Corti's organ structures in a small area of lower basal turns. 3. Decrease of spiral ganglion cell density was found over a 2% basilar membrane length in 2 stimulated cochleas. 4. There was no change in normal control cochleas. These results indicate that mild histopathological changes occurred even though chronic electrical stimulation was performed with non-invasive extracochlear electrodes. The mechanism behind these changes should be further investigated.

Effect of chronic electrical stimulation on cochlear nucleus neuron size in normal hearing kittens

Very young cochlear-implant candidates may have undetected islands of residual hearing. Would the maturation of these functioning auditory neurons be affected by chronic cochlear stimulation? This was tested by examining neuron sizes in the cochlear nuclei of young, normal hearing kittens with and without chronic cochlear stimulation. Six animals received bilateral intra- or extracochlear implants and were electrically stimulated unilaterally for periods of 1,000-1,500 hours. After sacrifice, cross-sectional areas of approximately 11,000 neurons somata in the cochlear nuclei were measured with an image-analysis system. There were statistically significant differences between stimulated and unstimulated nuclei, especially the posteroventral cochlear nucleus (PVCN), in individual cats, but the directions of the differences were inconsistent. Overall, there was no significant effect of electrical stimulation on soma size. These results indicate that chronic electrical stimulation of the auditory nerve has no positive or negative trophic effects on otherwise innervated, maturing cochlear nucleus neurons.

[A physiological investigation of chronic electrical stimulation with scala tympani electrodes in kittens]

A physiological investigation of cochlear electrical stimulation was undertaken in six two-month-old kittens. The scala tympani electrodes were implanted and electrically stimulated using biphasic balanced electrical pulses for periods of 1000-1500h in four ears. Four ears received implants for same period but without electrical stimulation. The other two ears served as normal control. The results indicated: 1) Chronic electrical stimulation of the cochlea within electrochemically safe limits did not influence the hearing of kittens and the normal delivery of impulses evoked by acoustic and electrical signals on the auditory brainstem pathway. 2) The wave shapes of EABRs were similar to those of ABRs. The amplitudes of EABRs showed a significant increase following chronic electrical stimulation, resulting in a leftward shift in the input/output function. The absolute latencies and interwave latencies of waves II-III, III-IV and II-IV were significantly shorter than those of ABRs. These results imply that there was no adverse effect of chronic electrical stimulation on the maturing auditory systems of kittens using these electrical parameters and the mechanism of electrical hearing should be further studied.

Cochlear pathology following chronic electrical stimulation of the auditory nerve. I: Normal hearing kittens

The present study examines the histopathological effects of long-term intracochlear electrical stimulation in young normal hearing animals. Eight-week old kittens were implanted with scala tympani electrode arrays and stimulated for periods of up to 1500 h using charge balanced biphasic current pulses at charge densities in the range 21-52 microC cm-2 geom. per phase. Both click and electrically evoked auditory brainstem responses were periodically recorded to monitor the status of the hair cell and spiral ganglion cell populations. In addition, the impedance of the stimulating electrodes was measured daily to monitor their electrical characteristics during chronic implantation. Histopathological examination of the cochleas showed no evidence of stimulus induced damage to cochlear structures when compared with implanted, unstimulated control cochleas. Indeed, there was no statistically significant difference in the ganglion cell density adjacent to the stimulating electrodes when compared with a similar population in implanted control cochleas. In addition, hair cell loss, which was restricted to regions adjacent to the electrode array, was not influenced by the degree of electrical stimulation. These histopathological findings were consistent with the evoked potential recordings. Finally, electrode impedance data correlated well with the degree of tissue growth observed within the scala tympani. The present findings indicate that the young mammalian cochlea is no more susceptible to cochlear pathology following chronic implantation and electrical stimulation than is the adult.

[Influence of moxibustion on TXA2 and PGI2 in plasma of rat infected epidemic hemorrhagic fever virus (EHFV)]

In this paper, the model of rat infected EHFV was made and the influence of moxibustion on TXA2 and PGI2 in its plasma was observed. The results show that the content of TXA2 increased and PGI2 decreased in rat significantly after the abdominal inoculation of EHFV, and the content of TXA2 decreased and PGI2 increased markedly in rat infected EHFV to normal level after treatment with moxibustion, suggesting that the regulative function of moxibustion on TXA2 and PGI2 is one of its nerve-endocrine-immune regulations to the body, and there is an important significance. This study provides an important reference for mechanism exploration of moxibustion preventing and treating EHF.

[Acoustically induced slow vertex potentials of patients with single channel inductive cochlear implant]

Acoustically induced slow vertex potentials (SVP) of 12 patients with single channel inductive cochlear implant were recorded in order to objectively evaluate the effect of this device on rebuilding hearing ability of totally deaf patients. We have found that the shape of SVP in patients was the same as that in healthy person and the average latency of every wave evoked by clicks of maximal comfortable loudness was close to those evoked by 60 and 70 dB nHL clicks in healthy people, but the average dynamic range was only 15 dB, and became smaller when the active electrode was put on the round window membrane. All these objectively prove that the acoustic stimulation elicited by single channel inductive cochlear implant is strong enough to activate the residual spiral ganglion cells and produce auditory sensation in cerebral cortex via the same central pathway as it is in the healthy.