Biomedical subjects

H Yu

Publications and source records attributed to H Yu.

At least 253 records · Page 14Linked to original sources

PubMed2000

Evidence for a dose-response effect between p53 (but not p21WAF1/Cip1) protein concentrations, survival, and responsiveness in patients with epithelial ovarian cancer treated with platinum-based chemotherapy.

The prognostic values of p53 and of its downstream mediator p21WAF1/Cip1 in patients receiving adjuvant chemotherapy for epithelial ovarian cancer have not been clearly established. Tumor extracts from a series of 120 patients treated postsurgically with cisplatin or carboplatin alone or together with other chemotherapeutics for primary ovarian carcinoma were assayed both for p53 protein by an immunofluorometric assay developed by us and for p21 protein by a commercially available immunoassay. Relative risks (RRs) for cancer relapse and death after 24 months of follow-up were determined by multivariate Cox regression analysis. Disease-free (DFS) and overall survival (OS) probabilities were also examined by the Kaplan-Meier method and log-rank tests. All other procedures were similarly nonparametric and based on two-sided tests of significance. Concentrations of p53 were elevated in patients with advanced stage disease (P = 0.02) or poorly differentiated (P = 0.03), suboptimally debulked tumors (P = 0.02), as well as in patients who failed to respond to chemotherapy (P = 0.03), as assessed by computed tomography scanning, serum CA125 determination, and second-look laparotomy. Statistically significant associations between concentrations of p53 and p21 were not found, nor were relationships demonstrated between concentrations of p21 and other clinicopathological variables or treatment response. Univariate analysis showed that p53 concentrations above the median indicated significantly higher risks for relapse (P = 0.04) and death (P < 0.01) and showed trends for increasing risks for relapse (P = 0.04) and death (P < 0.01) when p53 was considered as a four-level categorical variable. Multivariate analyses adjusted for age, stage, grade, and residual tumor size confirmed these observations (RR = 1.50; P = 0.05 for DFS and RR = 1.92; P = 0.03 for OS) for median-dichotomized p53, but the trends were of borderline significance (P = 0.09 for DFS and P = 0.07 for OS). In contrast, p21 positivity was not a significant predictor of favorable outcome in univariate survival analysis, and use of a three-level variable combining positivity or negativity status for both p53 and p21 did not yield greater separation of patients into risk groups (P = 0.07 for DFS and P = 0.06 for OS) than the use of p53 alone. Assessment of p53 expression may be an independent indicator of poor prognosis in ovarian cancer patients treated with adjuvant chemotherapy. The prognostic value of p21 expression, however, could not be demonstrated in our series of ovarian cancer patients.

Adult↗

PubMed2000

The molecular basis for the aberrant production of plasminogen activator inhibitor type 2 in THP-1 monocytes.

Plasminogen activator inhibitor type 2 (PAI-2) is a urokinase inhibitor that is expressed primarily in monocytes. THP-1 monocytes, however. contain a unique defect in the production of PAI-2 in that the PAI-2 transcript is truncated and the expressed protein inactive (1). Here we describe the basis of this mutation in THP-1 cells. Southern blot analysis of THP-1-derived genomic DNA indicated that there were no obvious deletions in the structure of the PAI-2 gene. However, assessment of the THP-1-derived PAI-2 transcript by RT-PCR indicated that only exons seven and eight of the normal PAI-2 mRNA could be detected. Cloning of the 5' region of the PAI-2 mRNA by 5-'RACE indicated that the PAI-2 cDNA derived from THP-1 cells is approximately 1329 bp long and contains 180 bp of sequence derived from intron 5. followed by sequences corresponding to exons seven and eight of the normal PAI-2 mRNA. The presence of the intron five fragment in endogenous THP-1 derived PAI-2 mRNA was confirmed by Northern blotting. The absence of any wild-type PAI-2 mRNA in these cells suggests that one copy of the PAI-2 allele has been deleted. The remaining allele producing the truncated mRNA appears to have undergone a translocation event and contains a mutation that has disrupted the splicing of the PAI-2 primary transcript.

Cloning, Molecular↗

PubMed2000

ABT-702 (4-amino-5-(3-bromophenyl)-7-(6-morpholinopyridin-3-yl)pyrido[2, 3-d]pyrimidine), a novel orally effective adenosine kinase inhibitor with analgesic and anti-inflammatory properties: I. In vitro characterization and acute antinociceptive effects in the mouse.

Adenosine (ADO) is an inhibitory neuromodulator that can increase nociceptive thresholds in response to noxious stimulation. Inhibition of the ADO-metabolizing enzyme adenosine kinase (AK) increases extracellular ADO concentrations at sites of tissue trauma and AK inhibitors may have therapeutic potential as analgesic and anti-inflammatory agents. ABT-702 is a novel and potent (IC(50) = 1. 7 nM) non-nucleoside AK inhibitor that has several orders of magnitude selectivity over other sites of ADO interaction (A(1), A(2A), A(3) receptors, ADO transporter, and ADO deaminase). ABT-702 was 1300- to 7700-fold selective for AK compared with a number of other neurotransmitter and peptide receptors, ion channel proteins, neurotransmitter/nucleoside reuptake sites, and enzymes, including cycloxygenases-1 and -2. ABT-702 was equipotent (IC(50) = 1.5 +/- 0. 3 nM) in inhibiting native human AK (placenta), two human recombinant isoforms (AK(long) and AK(short)), and AK from monkey, dog, rat, and mouse brain. Kinetic studies revealed that AK inhibition by ABT-702 was competitive with respect to ADO and noncompetitive with respect to MgATP(2-). AK inhibition by ABT-702 was demonstrated to be reversible after 4 h of dialysis. ABT-702 is orally active and fully efficacious in reducing acute somatic nociception (ED(50) = 8 micromol/kg i.p.; 65 micromol/kg p.o.) in the mouse hot-plate assay. ABT-702 also dose dependently reduced nociception in the phenyl-p-quinone-induced abdominal constriction assay. The antinociceptive effects of ABT-702 in the hot-plate assay were blocked by the nonselective ADO receptor antagonist theophylline, and by the A(1)-selective antagonist cyclopentyltheophylline (10 mg/kg i.p.), but not by a peripherally selective ADO receptor antagonist 8-(p-sulfophenyl)-theophylline (50 mg/kg i.p.), by the A(2A)-selective antagonist 3, 7-dimethyl-1-propargylxanthine (1 mg/kg i.p.) or the opioid antagonist naloxone (5 mg/kg i.p.). Thus, ABT-702 is a novel and potent non-nucleoside AK inhibitor that effectively reduces acute thermal nociception in the mouse by a nonopioid, non-nonsteroidal anti-inflammatory drug, ADO A(1) receptor-mediated mechanism.

Adenosine Kinase↗

PubMed2000

Allozyme diversity and population genetic structure of Pinus densata Master in northwestern Yunnan, China.

We investigated the levels and patterns of genetic diversity of Pinus densata Master in Yunnan. Horizontal starch-gel electrophoresis was performed on macrogametophytes collected from nine populations in northwestern Yunnan, China. Compared with other gymnosperm species, P. densata has higher mean values for all measures of genetic diversity. Allozyme polymorphism (0.99 criterion) was 97.0% and 71.4% at the species and population levels, respectively. The average number of alleles per locus was 3.1 and 2.0 at the species and population levels. Mean expected heterozygosity was substantially higher in P. densata than average values investigated for other gymnosperms both at the population (Hep = 0.174 +/- 0.031) and at the species (Hes = 0.190) levels. Of the total genetic variation, less than 12% was partitioned among populations (GST = 0.112). Our allozyme survey supports the suggestion that the observed higher diversity in P. densata may be attributed partly to its hybrid origin between two genetically distinct species, P. yunnanensis and P. tabulaeformis. In addition, we suggest that introgression would give rise to the increase in genetic diversity occurring in P. densata.

Alleles↗

PubMed2000

[Measure of vibration protection effect of driver's corset and analysis of its biomechanical effect].

The purpose of this study was to evaluate the vibration protection and biomechanical effect of driver's corset. The frequencies of vertfical and horizontal vibrations were measured at low back of driver. The vehicle driven was ISUZU truck (loading capacity 8 tons). Vibration of the driver's lumbar back was measured real time with wear corset and without wear corset when the truck loaded with 6 tons was driven at the spead of ten, thirty and sixty kilometers an hour on the asphalt road. The results showed: 1. Vibration frequencies at driver's low back was under 10 Hz. It is a low frequency vibration. 2. The value of vertical vibration was higher than the value of horizontal (back and forth) vibration. 3. The vibration value of wear corset was higher than un-wear corset. These indicate the driver's corset is effective for protecting lumbar spine by means of change in the biomechanical characteristics and the resonace requencies of lumbar spine. So the driver's corset is one of the good methods for preventing the back pain of drivers.

Automobile Driving↗

PubMed2000

[Determination of fructose-1,6-diphosphate with aldolase-DNPH by the colorimetric method].

This paper presents a modified method of enzymatic assay for Fructose-1,6-diphosphate(FDP). FDP is split to dihydroxyacetone phosphate (DAP) and glyceraldehyde-3-phosphate (GAP) by the action of aldolase. DAP is hydrolyzed at room temperature to free triose. Under alkaline conditions, the free triose is reacted with 2,4-dinitrophenylhydrazine (DNPH), yielding a 2,4-dinitrophenylhydrazine derivative which dissolve in alkali forming a purple color mixture, with maximum absorption at 540.nm. It is proportional to the contents of FDP. Because the method depends on the colorimetric determination of triose formed from fructose-1,6-diphosphate only by aldolase, glycerophosphate dehydrogenase/triosephosphate isomerase (GDH/TIM) and reduced nicotinamide adenine dinucleotide (NADH) which usually applied in multienzymatic method, are omitted in the modified method. The method is specific, convenient and accuracy for the determination of FDP.

Colorimetry↗

PubMed2000

Immunolocalization of uterine luminal fluid protein (ULF-250) in rat uterus.

OBJECTIVE: To access the production of a novel uterine luminal fluid 250 kD protein (ULF-250) during the various phases of the estrous cycle in relation to estrogen concentration, and to validate that the production and secretion of ULF-250 are regulated by estradiol and progesterone. METHODS: An immunohistochemical method was used to localize ULF-250 in rat uteri during each phase of the estrous cycle, and in uteri of ovariectomized rats treated with estradiol and progesterone. RESULTS: Positive immunostaining of ULF-250 occurred in the epithelial cells of the uterus at all phases of the estrous cycle; whereas the stroma was immunonegative. During the proestrus phase of the cycle, the glandular epithelial cells and glandular luminal content were stained strongly. During the estrus phase of the cycle, intense staining occurred in the glandular and uterine luminal epithelial cells, including the luminal content of the glands. In the metestrus phase of the cycle, only uterine epithelial cells were stained; during the diestrus phase, intense staining of the secreted contents of the uterine cavity and the glandular lumen occurred. The distribution of ULF-250 in the uteri of ovariectomized female rats treated with estradiol alone and estradiol plus progesterone were examined. In both groups, intense staining of the glandular luminal epithelial cells of the uterine endometrium occurred; in the estradiol-treated animals, only the luminal contents were stained. The present findings suggest that progesterone inhibits the secretion of ULF-250 that is stimulated by estradiol. CONCLUSIONS: ULF-250 is produced by the glandular and luminal epithelial cells of the uterine endometrium and fluctuates with the phases of the estrous cycle. Its production is stimulated by estradiol and its secretion is regulated by progesterone.

Animals↗

PubMed2000

[The imbalance of Th1/Th2 cytokine expression in peripheral blood mononuclear cell from asthmatic patients and the effect of erythromycin on these cytokines].

OBJECTIVE: To observe the state of Th1/Th2 cytokine expression in peripheral blood mononuclear cells (PBMCs) from asthmatic patients and the effect of erythromycin (Ery) on it. METHODS: 23 asthmatic patients and 10 healthy volunteers were included. The mRNA expression for Th1/Th2 cytokines in PBMC before and after the culture with Ery were detected by RT-PCR, considering IL-2 and IFN-gamma as Th1 cytokines, and IL-4, IL-6, IL-10 as Th2 ones. RESULTS: The positive rate of mRNA expression for Th2-derived IL-4, IL-6, IL-10 in the study group were 18/23, 19/23 and 10/23 respectively, and those for IFN-gamma and IL-2 produced by Th1 cells were 1/23 and 13/23, respectively. In the control group, the positive rate for IL-4, IL-6, IL-10 were 0/10, 2/10 and 1/10, respectively, and those for IL-2 and IFN-gamma were both 1/10. Comparing with the control group, the positive rate of mRNA expression for IL-4 and IL-6 in PBMC from asthmatic patients were significantly higher (P = 0.00003, 0.001 respectively). After the culture with Ery for 48 h, the positive rate for IL-4 expression in the study group decreased from 18/23 to 5/23 (P = 0.0006), and IL-6 from 19/23 to 9/23 (P = 0.006). The positive rate for IFN-gamma expression was elevated while IL-2 decreased(But both had no statistical significance). There was no difference observed before and after the culture with Ery in the control group. CONCLUSIONS: There is a predominant expression of Th2-type cytokines in PBMC from asthmatic patients. Ery can down-regulate the mRNA expression for IL-4 and IL-6 in asthmatic patients, and might convert the imbalance of Th1/Th2 cytokine expression in asthmatic patients.

Adult↗

PubMed2000

[The effect of methylenum coeruleum in laparoscope cholecystectomy].

OBJECTIVES: To help the operator correctly judge in operation the cystic gall duct and choledoch, and eliminate the operation wound. METHODS: To divide laparoscope cholecystectomy patients with the same weight at the same period into two groups: development group (589 cases) using methylenum coeruleum and conducting cholecysto-puncture visualization during the operation in which colors of cholecyst, cystic gall duct and choledoch turn blue; comparative group (553 cases) using regular laparoscope cholecystectomy. RESULTS: The two groups differed remarkably in operation time, complication, and transferring rate (P < 0.01). CONCLUSIONS: Methylenum coeruleum development technology in operation is a kind of visualization to help the operator judge in operation Calot triangular anatomy construction correctly, reduce the operation time obviously, and increase the rate of success.

Adult↗

PubMed2000

[Point mutations of N-ras oncogene and abnormal expression of rasp21, p53 proteins in orbital rhabdomyosarcoma].

OBJECTIVE: The point mutations of N-ras oncogene and the abnormal expression of rasp21 and p53 proteins in orbital rhabdomyosarcoma (RMS) were analyzed in order to explore the role of oncogene mutations in the pathogenesis of orbital RMS and its relation to patients' prognosis. METHOD: 21 human orbital RMS tissues were analyzed by dot-blot hybridization and immunohistochemistry using synthetic specific oligonucleotide probes and mutant rasp21, p53 monoclonal antibodies. RESULTS: The second base mutation of codon 12 of the N-ras oncogene was found in 4 patients. The third base mutation of codon 61 was found in 5 patients. The mutant rate was 33.3%. By immunohistochemistry analysis, the overexpression of rasp21 and p53 protein level was found in 42.9% and 76.2% respectively. The prognosis of patients with overexpression of ras p21, p53 was worse than that of normal expression (P < 0.01). CONCLUSION: The mutants of ras and p53 oncogene play important roles in the pathogenesis of orbital RMS, and the abnormal expression of their protein products is related to patients' prognosis.

Adolescent↗

PubMed2000

[The age-related effect of basic fibroblast growth factor on the proliferation of lens epithelial cells].

OBJECTIVE: To detect the age-related effect of basic fibroblast growth factor (bFGF) on the proliferation of human lens epithelial cells (HLECs) in patients with cataract and discuss the mechanism. METHODS: Human lens anterior capsules with attached HLECs were cultured in vitro, treated with 10 microg/L bFGF for 48hr, and then the positive area ratio of proliferating cell nuclear antigen (PCNA) in immunohistochemistry was estimated. Immunohistochemical analysis of bFGF receptor was also carried out. RESULTS: The bFGF could enhance the HLEC proliferation in patients with cataract at various ages. The enhancement of the proliferation and the expression of bFGF receptor protein were negatively correlated to the age of the patients with cataract (P < 0.01). CONCLUSIONS: The basic fibroblast growth factor might play an important role in the formation of posterior capsular opacity (PCO) after cataract surgery. With the decrease in the patient's age, the enhancement of HLEC proliferation is increased, indicating that the fact is related to the high incidence of PCO in children.

Adolescent↗

PubMed2000

[An epidemiological study on the incidence rates of colorectal cancer through different drinking water sources].

OBJECTIVE: In order to identify the association of incidence rates of colorectal cancer and different drinking water sources. METHODS: With the retrospective cohort method, 8 villages or townships in Haining city were randomly selected as the study area where a total 408 cases were collected during 1977 to 1996. The incidence rates according to the drinking water sources were calculated by sex and sites of the cancer. The RR estimates were given to each sex and site by comparing to that in well water source. RESULTS: The incidence rates of colorectal cancer by sequence of the sources were shown as follows drinking water: (male: pool water 126.04/10(5); female: 81.76/10(5)), river water (male: 45.06/10(5); female: 63.43/10(5)), tap water (male: 7.99/10(5); female: 5.17/10(5)) and well water (male: 3.19/10(5); female: 3.06/10(5)). All of them were statistically significance through chi(2) trend tests. Poisson test was used to have found the differences of incidences of colorectal cancer between different drinking water sources (P < 0.01). RR estimates showed that the risk of colorectal cancer with pool or river water sources were 7 times higher than that with well water. CONCLUSION: Study of this kind might uncover the differences which accounted for the associations between the drinking water sources and colorectal cancer.

China↗

PubMed2000

[Randomized controlled trial of sequence mass screening program for colorectal cancer].

OBJECTIVE: In order to assess the effectiveness of mass screening program for colorectal cancer, a sequence mass screening program based on RPHA-FOBT and individual quantitative risk assessment model (attributive degree value, AD) was used and evaluated on its effectiveness in a randomized controlled trial. METHODS: The residents of Jiashan county aged 30 years and over were randomized to either screening or control groups in 1989. Participants in screening group were asked to fill in a questionnaire and to submit one paper slide with stool. Participants who tested positive underwent diagnostic evaluations including flexible sigmoidoscopy and colonoscopy. RESULTS: According to the cancer registry of Jiashan, after initial mass screening in 1989, the 8-year cumulative incidence per 1,000 of colorectal cancer in screening and control groups appeared to be 3.95 (95% CI 3.81 - 4.10) and 4.01 (95% CI 3.86 - 4.16) respectively. There was no significant statistical difference between two groups (P > 0.05). Nevertheless, the 8-year cumulative mortality for colorectal cancer in screening group (2.08 per 1,000; 95% CI 1.96 - 2.18) was reduced 14.7% comparing with the control group (2.44 per 1,000; 95% CI 2.33 - 2.55). In particular, the cumulative mortality of rectal cancer was significantly (31.7%) lower than that in control group. Log-rank test showed that survival rate of rectal cancer in screening group was higher than that in controls (log-rank = 9.01, P = 0.0027). CONCLUSIONS: The sequential mass-screening program which based on RPHA-FOBT and ADV might reduce the mortality for colorectal cancer in the Chinese population.

Adult↗

PubMed2000

[Drinking water types, microcystins and colorectal cancer].

OBJECTIVE: To assess the relationship between microcystins (a blue-green algal toxin) in drinking water and colorectal cancer. METHODS: Eight townships were randomly selected as study sites in Haining city of Zhejiang province, China. Four hundred and eight colon and rectum carcinoma cases diagnosed from 1977 to 1996 were identified from cancer registry in the study sites. A retrospective survey on types of drinking water of all 408 cases was conducted. Population data and drinking water sources data were provided by local household registration and local health institution, respectively. Water samples from different sources (well, tap-water, river and pond) were collected and microcystins concentrations were measured by an indirect competitive ELISA method. RESULTS: The incidence rates of colorectal cancer were significantly higher among people drinking river or pond water than those who drank well water or tap-water in both males and females. And comparing with other sources to well water, the relative risks (RR) were much higher for people using river water (7.94) and pond water (7.70). The positive detection rates (> 50 pg/ml) of microcystin in well, tap-water, river and pond water were 0.00%, 0.00%, 36.23% and 17.14% respectively. The highest concentrations of microcystins were 1 083.43 pg/ml (river) and 1 937.94 pg/ml (pond) in the positive samples. Microcystins concentrations in river and pond were significantly higher than the concentrations in well and tap water (P < 0.01). The Spearman rank correlation analysis showed that in the study sites, the microcystins concentrations of river and pond water were positively correlated with the incidence of colorectal cancer (r = 0.881, P < 0.01). CONCLUSION: Drinking surface water (river or pond) is one of the risk factors for colorectal cancer. Microcystins may be associated with incidence of colorectal cancer. It is suggested that further study should be carried out to clarify the relationship between colorectal cancer and microcystin in drinking water.

Bacterial Toxins↗

PubMed2000

[Inhibition of hTR activity for suppression of lung cancer cell proliferation using antisense phosphorothioate oligonucleotides].

OBJECTIVE: Telomerase activity was measured in 8 lung tumor cell lines and transfected antisense phosphorothiate oligodeoxynucleotides (anti-PS-ODN) of hTR as therapeutic agents into target cell LTEP-a-2 to investigate the inhibitory effect on telomerase activity and tumor cell growth. METHODS: 1. Telomerase activity assay in 8 human lung tumor cell lines using telomerase PCR ELISA. 2. Synthesized anti-PS-ODNs of hTR and random PS-ODN transfected with Clonfectin into LTEP-a-2 cell lines for 72 hr. 3. Measure telomerase activity by telomerase PCR ELISA, SDH activity by MTT assay and cell growth. RESULTS: Eight cell lines showed positive expression of telomerase activity. Various anti-PS-ODNs could inhibit telomerase activity, SDH activity and cell growth. The inhibition became more marked with the increase of anti-PS-ODNs concentrations. Concentrations of 5 - 40 micromol/L anti-PS-ODNs of hTR specifically reduced the telomerase activity by 25.7% - 84.0%. PS-ODNs of anti-hTR were also able to reduce SDH activity by 19.4% - 74.7% at 5 - 40 micromol/L. The dose of 5 - 40 micromol/L PS-ODNs of anti-hTR had the ability to inhibit cell growth by 14.8% - 72.5%. The results indicate that random sequence of PS-ODN(9) failed to inhibit telomerase, SDH activity and cell growth. A statistically significant difference exists between random PS-ODN and three anti-PS-ODNs (P < 0.01). CONCLUSIONS: Human lung tumor cell lines express high telomerase activity. PS-ODNs of anti-hTR had the ability to inhibit telomerase and reduce LTEP-a-2 cell growth and metabolism.

Adenocarcinoma↗

PubMed2000

[Measuring and analyzing of otoacoustic emission tests of a family with genetic progressive sensorineural hearing loss].

OBJECTIVE: To study the diagnostic significance of otoacoustic emission in patients with genetic progressive sensorineural hearing loss. METHOD: To analyse the cochlear function pure tone audiometry Transient Evoked Otoacoustic Emission (TEOAE) and distortion Products Otoacoustic Emission (DPOAE) were measured in 54 members of a six-generation family with genetic progressive sensorineural hearing loss (108 cases) and 50 normal people. RESULT: The family was autosomal dominant heritage. In the group with pure tone thresholds more than 20 dB HL, the amplitudes of TEOAE descended or disappeared in 84% cases and the amplitudes of DPOAE declined or vanished in 82% cases. In the group with normal pure tone thresholds, the amplitudes of TEOAE descended in 75% cases and the amplitudes at one of the frequencies of DPOAE dropped or disappeared in 64% cases. But the incidence of TEOAE and DPOAE in normal people was 100%. CONCLUSION: OAE had important significance in the diagnosis of genetic hearing loss at early stage.

Adolescent↗

PubMed2000

[Study on production of poly-beta-hydroxybutyrate by recombinant strain VG1(pTU14)].

Cloning and expression of Vitreoscilla hemoglobin gene (vgb) and lambda phage lytic genes (S-RRz) in production of Poly-beta-hydroxybutyrate(PHB) was studied in different Escherichia coli hosts such as E. coliJM105, E. coliJM109 and VG1. In the recombinant strains, VG1(pTU14) was a superior one which simultaneously contained three exogenes including vgb, S-RRz and PHB biosynthesis genes(phbCAB). The experimental results showed that after 82 hours fed-batch cult ure in LBG medium in shaking flask, cell concentration of VG1(pTU14) could reach 25.9 g/L, which was the highest PHB production ever reported, and till 52 h PHB content could be higher than 95%. Additionally, inducible cell lysis was also attained successfully in recombinant VG1(pTU14) accompanying with its high cell density culture. Therefore, VG1(pTU14) is a novel potential strain with promising prospect in industrial production of PHB.

Bacterial Proteins↗

PubMed2000

[Examinations of distortion product otoacoustic emission in hereditary progressive non-syndromic hearing loss].

OBJECTIVE: To evaluate the hearing function in patients with hereditary progressive non-syndromic hearing loss. METHODS: Distortion product otoacoustic emissions (DPOAE) and pure tone audiometry were carried out in 52 individuals from a family with non-syndromic hearing loss and 15 persons with normal hearing. RESULTS: 1. Sensorineural hearing loss (SNHL) was found in 34 individuals of the family. Among these individuals, DPOAE was totally absent in 15 cases (29 ears) with pure tone average > or = 40 dB and low amplitude or absent middle to high frequencies in 12 cases (23 ears) with high frequency hearing loss but pure tone average < or = 35 dB. 2. Among 21 individuals (42 ears) with normal audiograms, DPOAE presented lower amplitude or absent high and middle frequencies in 12 individuals. CONCLUSION: DPOAE can be used in identification of subclinical pathologic alterations in the cochlea. This would be of particular value in early diagnosis and genetic consultation.

Audiometry, Pure-Tone↗