Biomedical subjects

Na Zhou

Publications and source records attributed to Na Zhou.

16 recordsLinked to original sources

PubMed2026

The first near telomere-to-telomere genome assembly of Panulirus homarus homarus.

The scalloped spiny lobster (Panulirus homarus homarus) is an economically important decapod crustacean with high aquaculture potential. Several chromosome-level genomes of this species have been reported. But the lobster or even entire shrimps did not have the telomere-to-telomere assembly until now. Therefore, we present the first near telomere-to-telomere genome assembly of P. h. homarus generated by using pure Oxford Nanopore Technologies ultra-long (ONT) reads and Hi-C sequencing. The final assembly anchored to 73 chromosomes with a contig N50 of 41.1 Mb. 73 chromosomes contain entire 146 telomeres, of which 51 chromosomes have no gaps. A total of 38,396 protein-coding genes were predicted. BUSCO analysis showed a completeness score of 99.8%, indicating a high degree of assembly completeness. This high-quality genomic dataset provides a valuable resource for comparative genomics, evolutionary studies, and genome-assisted breeding of spiny lobsters.

Animals↗

PubMed2006

Structure of the MTIP-MyoA complex, a key component of the malaria parasite invasion motor.

The causative agents of malaria have developed a sophisticated machinery for entering multiple cell types in the human and insect hosts. In this machinery, a critical interaction occurs between the unusual myosin motor MyoA and the MyoA-tail Interacting Protein (MTIP). Here we present one crystal structure that shows three different conformations of Plasmodium MTIP, one of these in complex with the MyoA-tail, which reveal major conformational changes in the C-terminal domain of MTIP upon binding the MyoA-tail helix, thereby creating several hydrophobic pockets in MTIP that are the recipients of key hydrophobic side chains of MyoA. Because we also show that the MyoA helix is able to block parasite growth, this provides avenues for designing antimalarials.

Amino Acid Sequence↗

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↗

PubMed2006

[Audio-vestibular function in patients with benign paroxysmal positional vertigo].

OBJECTIVE: To investigate the audio-vestibular function and the possible mechanism of benign paroxysmal positional vertigo (BPPV) and to raise the therapeutic strategy. METHODS: Patients with BPPV were tested with pure tone audiometry, high frequency ABR audiometry, bithermal caloric test and vestibular evoked myogenic potential test (VEMP). The positive rate of these otologic function test were analyzed. RESULTS: Primary BPPV comprised 82 percent (70/86) of patients with BPPV. Among all of the patients, the results of pure tone audiometry were abnormal in 52 percent (45/86) of the cases. High frequency auditory brainstem response (ABR) was abnormal in 60 percent (30/50) of cases. Vestibular evoked myogenic potential (VEMP) was abnormal in 34 percent (11/32) of cases who had this examination. And bithermal caloric test were abnormal in 28 percent (20/72) of cases. In the abnormal cases, 67 percent (12/18) of cases were ipsilateral with BPPV. The majority of the BPPV with abnormal results of bithermal caloric test (89%, 16/18) belong to posterior semicircular canal BPPV. CONCLUSIONS: The incidence of primary BPPV was higher than that of secondary BPPV. The abnormality in superior labyrinth was much more correlated with the occurrence of BPPV. The inner ear ischemia might be a factor in the morbidity of BPPV, especially for the primary BPPV.

Adolescent↗

PubMed2006

[Neurootological manifestation of migrainous vertigo].

OBJECTIVE: To analyzed the characteristics of migrainous vertigo (MV), a kind of paroxysmal vertigo, in order to demonstrate the extent of damage and dysfunction in MV and to judge whether MV is peripheral or central vertigo. METHODS: Twenty-two cases of acute (5 cases) or subacute (17 cases) MV were examined with oto-neurological tests, spontaneous nystagmus, positional nystagmus and auditory tests. RESULTS: There were 6 males and 16 females. Among those patients, 15 had migraine, 17 motion sickness, 15 family history of migraine or motion sickness, 1 visual aura, 7 motion intolerance (vertigo from head movement and body movement), 4 photophobia, 6 phonophobia and 5 vertigo from insomnia and emotion. There were likely to have vertigo in menstrual period in 2 cases. The duration of vertigo lasted from minutes to days. For pure-tone audiometric, 9 were normal which from mild to moderate hearing loss. Three cases had abnormal high frequency ABR bilaterally and 10 abnormal unilaterally. Subjective visual vertical were normal in all of the cases. Vestibular evoked myogenic potentials were abnormal in 14 cases (13 had low amplitude and 1 had longer latency of P13 wave). Bithermal caloric test was abnormal in 3 cases and 11 had abnormal ocular movement (9 with low gain of optokinetic nystagmus, 1 with overshoot in saccade and 1 with vertical nystagmus after head shaking), in which 10 had abnormal high frequency ABR and 1 was normal. CONCLUSIONS: MV could be peripheral or central vertigo and MV should be included in the differentiation of peripheral and central vertigo.

Adolescent↗

PubMed2006

[Clinical significance of vibration-induced nystagmus in patients with unilateral peripheral vestibular disorders].

OBJECTIVE: To clarify the clinical significance of vibration-induced nystagmus (VIN) and to calculate the sensitivity and the specificity of the vibration test. METHODS: One hundred and twelve patients with unilateral peripheral vestibular disorders and 30 normal subjects were enrolled into this study. However, patients with spontaneous nystagmus were excluded. Vibratory stimuli (approximately 92Hz) were presented to the mastoids and the forehead. Patients and normal subjects also underwent head shaking testing and caloric testing. RESULTS: Of the 112 patients, 91 (81%) showed VIN which were mainly horizontal. VIN was more frequently evoked on the mastoids than on the forehead. In the majority of patients (76 cases), the direction of VIN was toward the healthy side, whereas patients with Meniere's disease (15 cases), showed nystagmus toward the affected side. None of 30 normal subjects showed VIN. Whereas, HSN was found in 70 (63%) patients and 9 (30%) in normal subjects. Of 112 patients, 10 showed a canal paresis (CP) value of caloric test less than 25% ,while 32 with a CP value between 25% and 40%, 48 with a CP value between 40% and 70%, and 22 with a CP value more than 70%. It is notable that with increasing canal paresis value on caloric testing, VIN was more likely to be evoked. CONCLUSIONS: VIN testing is a simple, non-invasive and well-tolerated clinical test that indicates unilateral peripheral vestibular dysfunction. VIN testing had greater sensitivity and the specificity than HSN testing in the diagnosis of unilateral peripheral vestibular disorders.

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↗

PubMed2005

[Cross-check of caloric test and head shaking nystagmus].

OBJECTIVE: To investigate the manifestation of head shaking nystagmus (HSN) and the relationship between HSN and vestibular bithermal test while cross-checking the HSN and vestibular bithermal test. METHODS: One hundred and twenty-four patients were examined by HSN and vestibular bithermal test. The latency and duration of HSN were observed and the dynamic changes of HSN were also investigated. The results of bithermal test were clarified by the values of canal paresis (CP). RESULTS: There were 3 types of HSN, including 41 monophasic HSN, 11 biphasic HSN and 7 perverted HSN. The latency of monophasic HSN was (2.75 +/- 1.41) ms and the duration of it was (32.16 +/- 20.30) ms; as for the biphasic HSN, the first phase had no latency and the duration was (12.33 +/- 4.42) ms which was shorter than that of the second phase (57.00 +/- 17.19) ms (P < 0.01) and the latency of second phase was (57.00 +/- 17.19) ms. The value of canal paresis in the patients without HSN was lower than that in the patients with HSN. CONCLUSIONS: The existence of HSN was dependent on the loss of the function horizontal canal and also on the stage of vestibular compensation. The variation of duration of HSN among individuals was great. In the acute stage of unilateral vestibular function loss, there appeared to be prominent HSN, and the direction of HSN is the same as that of spontaneous nystagmus. With the development of vestibular compensation, biphasic nystagmus would appear instead of monophasic HSN and the direction of first phase represent the direction of un-lesioned side. After compensation, HSN would not be elicited. However,when HSN existed, it suggested that the value of CP should exceed 25%. Perverted nystagmus pointed to central abnormality.

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↗

PubMed2004

[Characteristics of the response of vestibular evoked myogenic potentials to different stimulus modes].

OBJECTIVE: Vestibular evoked myogenic potential (VEMP) has been utilized in clinic to test the function of saccule. In the present study, 3 stimulus modes were applied to 21 normal adults and intended to draw in a clinical test protocol. METHODS: The normal latency and amplitude of VEMPs of 21 normal subjects were recorded and the ratio of bilateral amplitudes and asymmetry were calculated. RESULTS: The response to binaural clicks were similar to the response of the monaural clicks. The interindividual variation in amplitude were large, but the latency varied little. CONCLUSIONS: VEMPs is a stable myogenic potentials. Monaural and binaural clicks stimulus can be used in clinical practice. The latter is appropriate for normal hearing subjects. Amplitude measurement is probable to evaluate the asymmetry of bilateral saccular function and may reveal saccule lesion.

Acoustic Stimulation↗

PubMed2004

[Inferior vestibular nerve impairment in auditory neuropathy].

OBJECTIVE: To investigate if auditory neuropathy have inferior vestibular nerve (IVN) lesion and to explore the relation between AN and the IVN lesion by vestibular evoked myogenic potentials (VEMPs). METHODS: VEMPs were observed in 13 patients with auditory neuropathy. And the relation among the duration, hearing threshold of lower frequency and speech discrimination score with VEMPs were observed. RESULTS: Fifty-four percent patients in auditory neuropathy had abnormal VEMPs. They took the form of lower amplitude and no response. The statistical analysis showed that the abnormality of VEMPs had no correlation with lower frequency hearing loss, the duration and speech discrimination score. CONCLUSIONS: The IVN dysfunction may coexist with auditory neuropathy, having lesion in the IVN. However, there was no significant relation between the severity of AN and VEMPs, which meant that AN and inferior vestibular neuropathy had their independence to some extent.

Adolescent↗

PubMed2003

Evolution of OTP-independent larval skeleton patterning in the direct-developing sea urchin, Heliocidaris erythrogramma.

Heliocidaris erythrogramma is a direct-developing sea urchin that has evolved a modified ontogeny, a reduced larval skeleton, and accelerated development of the adult skeleton. The Orthopedia gene (Otp) encodes a homeodomain transcription factor crucial in patterning the larval skeleton of indirect-developing sea urchins. We compare the role of Otp in larvae of the indirect-developing sea urchin Heliocidaris tuberculata and its direct-developing congener H. erythrogramma. Otp is a single-copy gene with an identical protein sequence in these species. Expression of Otp is initiated by the late gastrula, initially in two cells of the oral ectoderm in H. tuberculata. These cells are restricted to oral ectoderm and exhibit left-right symmetry. There are about 266 copies of Otp mRNA per Otp- expressing cell in H. tuberculata. We tested OTP function in H. tuberculata and H. erythrogramma embryos by microinjection of Otp mRNA. Mis-expression of Otp mRNA in H. tuberculata radialized the embryos and caused defects during larval skeletogenesis. Mis-expression of Otp mRNA in H. erythrogramma embryos did not affect skeleton formation. This is consistent with the observation by in situ hybridization of no concentration of Otp transcript in any particular cells or region of the H. erythrogramma larva, and measurement of a level of less than one copy of endogenous Otp mRNA per cell in H. erythrogramma. OTP plays an important role in patterning the larval skeleton of H. tuberculata, but this role apparently has been lost in the evolution of the H. erythrogramma larva, and replaced by a new patterning mechanism.

Animals↗

PubMed2003

[Phanerogenetic retrocochlear low frequency hearing loss].

OBJECTIVE: To study the pathogenisis of retrocochlear low frequency hearing loss. METHODS: Clinical and audiologic findings [auditory brainstem response (ABR), evoked otoacoustic emission (EOAE), et al] of 29 cases with retrocochlear low frequency hearing loss were studied. RESULTS: The head injury, acoustic neuroma, peripheral neurophathy, hereditary hear loss, multiple sclerosis and brainstem disease can cause retrocochlear low frequency hearing loss. The typical clinical manifestations of retrocochlear low frequency hearing loss were normal EOAE which cannot be suppressed by contralateral white noise, but with abnormal ABR as well as with no acoustic reflex and -SP/AP > 0.44. CONCLUSIONS: The results suggest that phanerogenetic retrocochlear low frequency hearing loss should be a syndrome rather than a disease called "auditory neuropathy". The main lesions of the disease are brainstem, cochlear nuclei and auditory nerve.

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↗