Biomedical subjects

Suzhen Zhang

Publications and source records attributed to Suzhen Zhang.

7 recordsLinked to original sources

PubMed2006

[Diagnosis of delayed endolymphatic hydrops].

OBJECTIVE: To investigate the diagnostic methods and significance of several tests for delayed endolymphatic hydrops (DEH). METHOD: Fifteen patients with delayed endolymphatic hydrops were tested with pure tone threshold, ECochG, bithermal caloric test and vestibular evoked myogenic potentials test to detect the lesioned side and the extent of hydrops. RESULT: All of the 15 patients had sensorineural hearing loss to the medium-severe extent at least. Ten were the ipsilateral type, four contralateral type and one bilateral type. Five cases had abnormal horizontal semicircular canal (HSCC) hydrops and saccular hydrops; six cases had abnormal HSCC function and normal saccular function; two cases had abnormal saccular function and normal HSCC function. The seven abnormal VEMP took the forms of loss of p13-n23, elongation of the latency of p13 or depressed amplitude cases with of p13-n23. CONCLUSION: ECochG, bithermal caloric test and VEMP may play a major role in the diagnosis of delayed endolymphatic hydrops and they should be utilized as the routine tests.

Adolescent↗

PubMed2006

[Significance of some otologic function tests in diagnosis of Meniere's disease].

OBJECTIVE: To investigate the significance of vestibular function battery and electrocochleogram on diagnosis of Meniere's disease. METHOD: Patients with Meniere's disease were given pure tone hearing threshold test, auditory brainstem responses (ABR), electrocochleogram (ECoG), vestibular bithermal caloric test and vestibular evoked myogenic potentials (VEMP) test. RESULT: (1) As for the bithermal caloric test, the percentage of the abnormal canal paresis (CP) at three durations, i.e. , 0 to approximately 5 years, 6 to approximately 10 years and over 11 years were 56.9%, 75.9% and 61.6% respectively. The total positive rate was 50.0%. CP and duration of Meniere's disease had low correlation (P < 0.05). (2) The percentage of the abnormal VEMP at three durations, i.e., 0-5 years,6-10 years and over 11 years were 57.4%, 60% and 57.1% respectively. The total positive rate was 58.0%. The duration of Meniere 's disease with normal and abnormal VEMP had no significant difference( P >0.05). (3) The percentage of the abnormal ECoG at three durations, i.e., 0-5 years, 6-10 years and over 11 years were 72.1%, 73.3% and 81.3% (49/68,22/30 and 13/16) respectively. The total positive rate was 76.9%. The duration of Meniere's disease with normal and abnormal ECoG had no significant difference (P >0.05). CONCLUSION: Diagnosis of Meniere's disease is mainly based on the medical history. If it could combine with ECoG, bithermal caloric test and VEMP, the diagnosis would be earlier and more accurate.

Adolescent↗

PubMed2006

[Complementation of head shaking nystagmus and bithermal caloric test].

OBJECTIVE: To investigate the complementary relation between head shaking nystagmus (HSN) and bithermal caloric test. METHOD: All of the 60 patients with vertigo were tested with bithermal caloric test, HSN and audiological tests. RESULT: There were 19 patients with normal CP and HSN, in which 8 had shared the same direction (towards the uninjured side) and 11 indicated opposite direction(HSN towards the lesioned side). Ten patients had normal CP with no HSN. Eight patients had abnormal CP and no HSN. In 23 patients with abnormal CP and HSN, HSN in 19 patients had opposite direction against that of CP and HSN in 4 patients had the same direction with that of CP (towards the lesioned side). CONCLUSION: HSN and bithermal caloric test had the complementary effects and it is helpful to interpret the vestibular function more accurately if they are applied together.

Adolescent↗

PubMed2005

[The significance of the interaural latency difference of VEMP].

OBJECTIVE: To investigate the significance of the interaural latency (IAL) difference of the latency of VEMP and to raise the sensitivity of the test. METHOD: Vestibular evoked myogenic potentials (VEMP) were tested in 20 healthy subjects; 13 patients with acoustic neuromaor cerebellopontile angle occupying lesions and 1 patient with multiple sclerosis. IAL differences of the wave p13,n23 and p13-n23 (abbreviatd as /delta p13/, /delta n23/ and /delta p13-n23/, respectively) were analysed to determine the normal range and the upper limit of the norm data. Four illustrative cases with the abnormality of the IAL difference were given as examples. RESULT: The upper limit of the IAL of /delta p13/ was 1.13 ms; that of the /delta n23/ was 1.38 ms and that of /delta p13-n23/ was 1.54 ms. The /p13-n23/ latency between the right and left side had no significant difference (P > 0.05). CONCLUSION: /delta p13/, /delta n23/ and /delta p13-n23/, especially /delta p13/ of VEMP can suggest abnormality in the neural pathway and it may be applicable in practice.

Adolescent↗

PubMed2004

[The saccular function in Meniere's disease].

OBJECTIVE: To record and analyze the vestibular evoked myogenic potentials (VEMP) in Meniere's disease. METHOD: VEMP in 15 patients diagnosed as Meniere's disease were investigated and made out different kinds of manifestation of VEMP. The results of VEMP were compared with these caloric test. RESULT: The wave of p13 and n23 appeared 100% in normal subjects, but only appeared 30% in Meniere's disease. There were 3 kinds of manifestation of VEMP-normal response, bilateral no response and lower amplitude in hydrops side. CONCLUSION: Membranous hydrops in Meniere's disease may damage the saccular function and VEMP test may be helpful for diagnosis of Meniere's disease.

Adolescent↗

PubMed2002

Changes in Ca2+-ATPase in a guinea pig endolymphatic hydrops model.

OBJECTIVE: To investigate the localization of Ca(2+)-ATPase (Ca(2+) pump) in the cochlear and its change after endolymphatic hydrops, and to study the relationship between compound action potential (CAP) threshold and the Ca(2+)-ATPase activety. METHODS: The left endolymphatic sac was ablated to induce endolymphatic hydrops in fourteen healthy guinea pigs with normal action potential thresholds measured after a sliver ball electrode placed on the round window. Ca(2+)-ATPase activity was studied cytochemically using a lead citrate reaction in control and hydropic ears. The reaction product was lead phosphate particles as an expression of Ca(2+)-ATPase activity, observed with an eletron microscope. RESULTS: Ca(2+)-ATPase activity is mainly found on the endolymphatic surface of Reis sner's membrane, the stereocilia and cuticular plate of inner and outer hair cells, and along the infolded plasma membrane of strial marginal cells. CAP thresholds of filtered click are increased and Ca(2+)-ATPase activity significantly decreased after endolymphatic hydrops in the mentioned locations. CONCLUSIONS: CAP thresholds are increased and Ca(2+)-ATPase activity are significantly decreased in the cochlea after endolymphatic hydrops. These results suggest that there is a negative correlation between them.

Action Potentials↗

PubMed2002

Adenoviral mediated suicide gene transfer in the treatment of pancreatic cancer.

OBJECTIVE: To determine the efficacy of adenovirus mediated suicide gene transduction combined with prodrug 5-fluorocytosine (5FC) as a therapeutic protocol for pancreatic cancer. METHODS: Cytosine Deaminase(CD) gene was cloned into pAdTrack-CMV-CD, pAdTrack-CMV-CD and pAdEasy-1 were recombined in bacteria. The newly recombined adenovirus (Ad)-CD containing green fluorescent protein (GFP) were packaged and propagated in 293 cells and purified by cesium chloride gradient centrifugation. Human pancreatic carcinoma cell line-Patu8988 was infected with this virus, then 5FC was added. XTT assay was used to estimate relative numbers of viable cells. In vivo model of pancreatic cancer was established by injecting 1.0 x 10(7) Patu8988 cells subcutaneously in Balb/c nude mice. When tumors were palpable, Ad-CD was injected into each tumor and 5FC was administered. RESULTS: Positive clones were selected using endonuclease to digest the recombinants and the concentration of viral liquids containing the CD gene was 2 x 10(11) pfu /ml. Significant cytotoxic activity as shown for 5FC in the CD gene transduced 8988 cell line, while little effect was found in the nontransduced pancreatic carcinoma cells. Antitumor effect was observed in Patu8988 xenograft nude mice with in situ CD gene transduction. CONCLUSIONS: CD gene mediated by adenovirus has high infectivity and may be useful for gene therapy in pancreatic carcinoma. These data demonstrate the use of an enzyme prodrug strategy in experimental pancreatic cancer.

Adenoviridae↗