Analyses prognostic factors relevant to sudden sensorineural hearing loss / 中华耳鼻咽喉头颈外科杂志

<p><b>OBJECTIVE</b>To investigate the prognostic factors relevant to sudden sensorineural hearing loss.</p><p><b>METHODS</b>The internationally accepted standardized clinical research methods, unified design, and unified program were adopted to conduct the prospective clinical multi-center study. The sudden deafness patients between 18 to 65 years old, with the course of this disorder less than two weeks, and without any medical treatments were collected, and then, divided into four types according to the hearing curve: type A, acute sensorineural hearing loss in low tone frequencies; type B, acute sensorineural hearing loss in high tone frequencies; type C, acute sensorineural hearing loss in all frequencies; and type D, total deafness. The factors, in terms of age, gender, type of initial audiogram, time delay before the first visit, and severity of hearing loss, were included in the analyses.</p><p><b>RESULTS</b>A total of 1 024 cases with single side sudden deafness were collected in the study from 33 hospitals in China from August 2007 to October 2011, inclusive of for 492 males (48.05%) and 532 females (51.95%). The average age was (41.2 ± 12.8) years old. There were 553 cases (54.00%) in left ear, and 471 cases (46.00%) in right ear. The curative effects of different types were shown as follows: the type in low tone frequencies had the highest rate of 90.73%, the type in all frequencies was 82.59%; the type of total deafness was 70.29%; and the type in high tone frequencies had the lowest rate of 65.96%. It had significant difference of the effective rate between different types (χ(2) = 231.58, P = 0.000). Age, time delay before first visit, and severity of initial hearing loss were significantly correlated with hearing improvement.</p><p><b>CONCLUSIONS</b>Initial audiogram of SSNHL might predict hearing recovery. The young in age and a short time delay before starting treatment are positive prognostic factors for hearing recovery in SSNHL. The initial severity of hearing loss is negative prognostic factor of hearing recovery.</p>

The replacement therapy of rPTH(1-84) in established rat model of hypothyroidism / 中华耳鼻咽喉头颈外科杂志

<p><b>OBJECTIVE</b>To investigate the replacement therapy of rPTH(1-84) (recombinant human parathyroid hormone (1-84)) to hypothyroidism in established rat model.</p><p><b>METHOD</b>Rat model of hypothyroidism was established by resecting parathyroids. A total of 30 rats with removal of parathyroids were divided into 6 groups randomly, 5 in each group, and applied respectively with saline injection (negative control group), calcitriol treatment (positive control group) and quadripartite PTH administration with dose of 20, 40, 80 and 160 µg/kg (experimental groups). Saline and rPTH(1-84) were injected subcutaneously daily. Calcitriol was gavaged once a day. Sham-operation was conducted in 5 rats of negative control group. To verify the authenticity of the rat model with hypothyroidism, the serum was insolated centrifugally from rat blood that was obtained from angular vein at specific time to measure calcium and phosphorus concentration. Urine in 12 hours was collected by metabolic cages and the calcium concentration was measured. After 10-week drug treatment, the experiment was terminated and bilateral femoral bone and L2-5 lumbar vertebra were removed from rats. Bone mineral density (BMD)of bilateral femoral bone and lumbar vertebra was analyzed by dual X-ray absorptiometry (DXA). The concentration of bone alkaline phosphatase (BALP) in serum was determined by radioimmunoassay.</p><p><b>RESULT</b>The rat model with hypothyroidism was obtained by excising parathyroid gland and was verified by monitoring calcium and phosphorus concentration subsequently. Administration of rPTH(1-84) in the dose of 80 or 160 µg/kg made serum calcium and phosphorus back to normal levels, with no significant difference between the doses (P>0.05). The BMD in each group of rats with rPTH(1-84) administration was increased significantly (P<0.05). The levels of urinary calcium and serum BALP in rats of maximum rPTH(1-84) injection group (160 µg/kg) were higher than those of normal control group (P<0.05). The rats treated with calcitriol had normal calcium levels and showed the increase of BMD and phosphorus concentration compared with normal control group (P<0.05). The amount of urinary calcium also exceeded the other groups (P<0.05), but no with significant difference in BMD of bilateral femoral bone and lumbar vertebra between negative control group and normal control group (P>0.05).</p><p><b>CONCLUSION</b>Calcium and phosphorus return to normal level by administration of rPTH(1-84) in the dose of 80 µg/kg or 160 µg/kg, with increase in BMD. Calcitriol can return the level of calcium to normal and increase BMD, but can not correspondingly decrease the phosphorus concentration and increase the excretion of calcium in urine.</p>