[Analyses of audiological examination in children without auditory brainstem response].

Objective: To investigate residual hearing of children severe and profound sensorineural deafness in whom wave V was not found in auditory brainstem response(ABR) testing, and to emphasize the importance of objective audiological tests. Methods: Two hundred and fifty-two children who were admitted to the Second Affiliated Hospital of Zhengzhou University between January 2015 and April 2018, with an average age of 20 months from 72 days to 4 years, received a full battery of objective audiological tests consisting of distortion product otoacoustic emission(DPOAEs), tympanometry, auditory brainstem responses(ABRs), 40 Hz auditory event related potential(40 HzAERP) and auditory steady-state response(ASSRs).There were 159 males(318 ears) and 93 females(186 ears). Residual hearing obtained by 40 HzAERP、ASSR of 252 children with sensorineural deafness was studied in relation to the absence of wave V in click ABR. SPSS 16.0 software was used to analyze the data. Results: Four hundred and forty-four ears of 504 ears have residual hearing of different degrees at different frequencies(88.1%),60 ears (11.9%) were found in whom responses was not found in 40 HzAERP、ASSR testing; Seventy-two ears(14.3%) in 38 patients were tested cochlear microphonic potentials (CMs). Conclusion: In children hearing evaluations,a full battery of objective audiological tests could better investigate residual hearing; The CMs were tested could provide the Audiotery Neuropathy diagnosis in infants with OAEs and ABR absent.

[Clinical analysis of 54 patients with non-syndromic enlarged vestibular aqueduct].

Objective:To further recognize the clinical characteristics of non-syndromic enlarged vestibular aqueduct through the retrospective analysis of cases, with the purpose of providing references for clinical diagnosis and treatment. Method:Collect 54 cases of non-syndromic enlarged vestibular aqueduct, and analyze their clinical characteristics after history taking, physical examination, audiometry and imaging examination. Measure the biggest width of midpoint between internal and external of vestibular aqueduct on temporal bone thin-section CT, and analyze the relationship between the pipe width and sides of ear, types of hearing loss and degree of hearing loss through t test. Result:All 54 patients with non-syndromic enlarged vestibular aqueduct had bilateral ear involvement. There were 42 cases with prelingual deafness, 12 cases with postlingual deafness, and there were 38 ears with severe deafness, 70 ears with profound deafness. Ninety-six ears of hearing loss showed sensorineural deafness, and 12 ears manifested mixed deafness. The biggest width of midpoint between internal and external of vestibular aqueduct spread over 1.60-3.90 mm, and the average was 2.60 mm. There were no significant differences in data between left and right sides, degree of hearing loss and type of hearing loss. Conclusion:Non-syndromic enlarged vestibular aqueduct mainly manifests serious sensorineural deafness, and the diagnosis depends on imaging examination. There is no difference in the degree of expanding between left and right ear, and the extent of enlargement is not related to the type and the severity of hearing loss.

Rapid detection of anabolic steroids in urine by protein arrays.

The purpose of this study was to develop a rapid and sensitive method utilizing the state-of-the-art protein arrays technique to detect urinary anabolic steroids (ASs) in athletes. Three experiments were designed to investigate the feasibility of the protein arrays for ASs testing. Firstly, androgen receptor (AR) and estrogen receptor (ER) protein arrays were prepared on polysaccharide-coated slides to investigate whether they can bind to ASs (affinity tests). Secondly, in comparison to adrenergic receptor (the receptor of beta-blockers) and opioid receptor (the receptor of narcotic analgesics) arrays, AR and ER protein arrays were used to test whether they can determine the ASs positive urine sample specifically (specific binding tests). At last protein arrays were used to estimate qualitatively the ASs in positive urine samples (qualitative tests). From the results of the affinity tests the shape of the dose-dependence curve suggested a positive cooperative binding of ASs with the protein arrays. The AR and ER protein arrays showed affinities for fluorescence labelled testosterone and estradiol that were similar to those of literatures (0.65 vs. 0.89 nM, 5.96 vs. 10.3 nM, respectively). Based on the data, the sensitivity of testing can reach 0.1 nM that was much better than the World Anti-Doping Code (WADA) standard. Specific binding tests showed that the prohibited substance in positive urine samples belonged to the anabolic estrogenic inhibitor of ASs. From the results of qualitative tests, we could estimate that there were anabolic androgenic steroids in the positive urine samples and their concentration was lower than 50 microM Methyltestosterone. The total time of the test process for ASs in urine needed less than 1 h. In summary, the present study showed that the protein arrays method provided a highly sensitive and rapid alternative to screen urine samples for the detection of the misuse of ASs in athletes and was suitable for testing in both weekly training sessions as well as large-scale competition events.

Antiproliferative effects of D-polymannuronic sulfate on rat vascular smooth muscle cells and its related mechanisms.

AIM: To investigate the inhibitory effects of D-polymannuronic sulfate (DPS) on the proliferation of rat vascular smooth muscle cells (VSMC) induced by angiotensin II (Ang II) and its related mechanisms. METHODS: The effects of DPS on Ang II-induced proliferation of VSMC were evaluated by MTT assay. The intracellular free Ca2+ concentrations, protein contents, and cell cycle were analyzed by flow cytometry. RESULTS: DPS 0.001 - 100 mg/L blocked the cell cycle at the G0/G1-->S transit and prevented the cells from entering into the G2/M phase, and its inhibitory effects on an increase in intracellular free Ca2+ concentrations and the protein synthesis of VSMC were also observed. Also, the suppressing actions of DPS on intracellular Ca2+ were completely blocked by L-NAME, a nitric oxide synthase inhibitor, indicating that the counteracting effects on a rise in intracellular free Ca2+ contents by DPS might be mediated by participation of NO. CONCLUSION: DPS exerted an inhibitory effect on Ang II-induced proliferation of VSMC and its related mechanisms were considered to be related to its inhibition on the increment of intracellular Ca2+ concentrations, which subsequently suppressed the synthesis of DNA and protein of VSMC.

[Inhibitory effects of D-polymannuronic sulfate on proliferation of rat vascular smooth muscle cells and its related mechanisms of action in vitro].

AIM: To investigate the inhibitory effects of D-polymannuronic sulfate (DPS) on the proliferation of rat vascular smooth muscle cells (VSMC) induced by basic fibroblast growth factor (bFGF) or interleukin-1 (IL-1) and its related mechanisms. METHODS: Rat aortic smooth muscle cells pretreated with DPS in concentrations ranging from 0.001 microgram.mL-1 up to 100 micrograms.mL-1 were incubated at 37 degrees C for 24 h, followed by addition of bFGF (50 ng.mL-1) or IL-1 (50 U.mL-1) for another 24 h. The effects of DPS on the proliferation of VSMC were evaluated by MTT assays. VSMC were pretreated with DPS in concentrations ranging from 0.001 microgram.mL-1 up to 1 microgram.mL-1, followed by addition of L-NAME (0.1 microgram.mL-1) or bFGF (50 ng.mL-1) for 24 h. Supernatant nitric oxide (NO) was determined with NO assay kit, while supernatant angiotensin II (Ang II) and endothelin-1 (ET-1) were measured by radioimmunoassay. RESULTS: DPS exerted antiproliferative effects at concentrations ranging from 0.01 microgram.mL-1 to 10 micrograms.mL-1, and its maximal effect was observed at the concentration of 1 microgram.mL-1. Also, the suppressing actions of DPS on the proliferation of VSMC were diminished by increasing the concentrations of bFGF or IL-1. Furthermore, DPS increased NO synthesis and decreased Ang II and ET-1 contents released from VSMC in a concentration-dependent manner. CONCLUSION: DPS afforded the antiproliferative effects on bFGF- or IL-1-treated VSMC and its underlying mechanisms were associated with enhancement of NO synthesis and decrement of Ang II and ET-1 production/release in vitro.

Antihypertensive effects of D-polymannuronic sulfate and its related mechanisms in renovascular hypertensive rats.

AIM: To investigate the antihypertensive effects of D-polymannuronic sulfate (DPS), a kind of sulfated polysaccharide, and the underlying mechanisms in renovascular hypertensive rats (RHR). METHODS: Used two-kidney one clip (Goldblatt, 2-K 1C) method to produce RHR model. DPS was given i.v. or ig for 5 wk with the initiation of establishment of RHR. Serum nitric oxide (NO) was determined with NO kit; plasma angiotensin II (Ang II) and endothelin-1 (ET-1) were measured by radioimmumoassays. RESULTS: In acute therapeutic experiments, DPS markedly reduced systolic blood pressure (SBP) and diastolic blood pressure (DBP) dose-dependently and decreased heart rate (HR) with reduction in arterial blood pressure. In the prophylactic experiments, DPS prevented the rise in SBP and DBP in a dose-dependent manner. The hypotensive potency of DPS 50 mg/kg is comparable to that of captopril (14 mg/kg). Moreover, DPS elevated serum NO contents and lowered plasma concentrations of Ang II and ET-1. CONCLUSION: The antihypertensive activities of DPS might be involved both in increasing the generation of nitric oxide and in decreasing the production of angiotensin II and endothelin-1 in vivo.

Protective effects of pyridoxal phosphate against glucose deprivation-induced damage in cultured hippocampal neurons.

When hippocampal cultures were deprived of glucose, massive release of lactate dehydrogenase (LDH), an indicator of neuronal death, occurred via NMDA receptor activation. Addition of pyridoxal phosphate (PLP; 1 and 10 microM) inhibited this LDH release in a concentration-dependent manner. Prior exposure to PLP evoked more potent inhibitory effects on LDH release compared with those treated at the onset of glucose deprivation. Furthermore, PLP inhibited the reduction of intracellular content of pyruvate induced by glucose deprivation, which was accompanied by the reversal of intracellular ATP depletion. A noteworthy elevation of extracellular glutamate in response to glucose deprivation was completely reversed by addition of PLP. Aminooxyacetic acid, a potent inhibitor of PLP-dependent enzymes, antagonized the effects of PLP on LDH release, pyruvate production, and ATP formation. These results suggest that PLP protects neurons from glucose deprivation-induced damage by enhancing the formation of energy-yielding products and relieving extracellular load of glutamate. The observed phenomena further indicate that PLP might be used prophylactically against neuronal death induced by metabolic disorders.

Protective effect of ifenprodil against glucose deprivation-induced damage in cultured rat hippocampal neurons.

When hippocampal cultures were deprived of glucose, massive release of lactate dehydrogenase (LDH), an indicator of neuronal death, occurred 24 hr following the onset of hypoglycemic insult via N-methyl-D-aspartate (NMDA)-type glutamate receptor activation. Ifenprodil (0.1 and 1 M) significantly inhibited LDH release, which was antagonized by polyamines. These results suggest that ifenprodil protects neurons from glucose deprivation by antagonizing the effects of glutamate via selective interaction with polyamine modulatory sites on the NMDA receptor complex. The observed phenomenon further indicate that ifenprodil might be used prophylactically against neuronal death induced by excitotoxic disorders.

Effects of vitamin B6 and its related compounds on survival of cultured brain neurons.

The effects of pyridoxine and its derived cofacter, pyridoxal phosphate (PLP) on the survival of primary cultured neurons from fetal rat brain were investigated. Pyridoxine and PLP significantly promoted the neuronal survival of various brain regions in high cell density culture (10(5) cells/cm2), but showed no positive effects on hippocampal neurons in low cell density culture (5 x 10(3) cells/cm2). This neurotrophic effect of PLP was remarkably suppressed by picrotoxin and ifenprodil. Aminooxyacetic acid (AOAA), an inhibitor of PLP dependent enzymes, caused significant neuronal loss by itself, and largely counteracted the neurotrophic effect of PLP. Taken together, we presume that vitamin B6 afforded the survival-promoting activities of cultured neurons by virtue of its crucial coenzymatic actions in the biosynthesis of putative neurotransmitters.

The effects of thiamine and oxythiamine on the survival of cultured brain neurons.

The effects of treatment with thiamine (Vitamin B1) alone or together with its antagonist oxythiamine on the survival of brain neurons in primary culture were investigated. Treatment with thiamine significantly promoted the survival of hippocampal neurons in high cell density culture, but had no effects on the neuronal survival in low cell density culture. In addition, the survival-promoting activity exerted by thiamine was remarkably decreased by the co-application of oxythiamine, although oxythiamine used alone revealed neither a trophic nor toxic effect on the neurons of examined brain regions. The neurotrophic function of thiamine may be due to its coenzymatic role in a biochemical reaction and/or its specific function on neurotransmission and nerve conduction.