determine the UVR radiation intensity of sunlight. The sunlight intensity was measured during
the 3 weeks before and 3 weeks after 22nd June in the Northern Hemisphere. The latitudes range
from 20° to 45.7°, north latitude. The altitudes are located between the sea level and the height of
3300m. Results: Conclusions 1) The higher the altitude is the greater increase in UVR intensity
per 1000m. At different latitudes at sea level, there is a 1% or 1~2% UVR intensity. 2) We
developed two formulas which we can be used to calculate the UVR intensity of any region
whose location is between 20°and 45.7° north latitude and is below an elevation of 500m. UVR
intensity also can be calculated at any height at 36° north latitude in China.
135.
CLINICAL STUDY OF THE OSCILLATORY POTENTIALS IN DIABETIC RETINOPATHY
AT HIGH ALTITUDE. Zhao Li
1
. Department of Ophthalmology, Qinghai Red Cross Hospital
Xining China
1
.
To investigate at high altitude the sensitivity index of oscillatory potentials (oPs) in diabetic
retinopathy (DR) with early diagnoses, to provide functional and morphological information for
current diabetic retinopathy classification. Methods: 62 diabetic patients, of which, 115 eyes were
examined using fundus ophthalmoscpoe. The eyes were divided into 3 groups, with no visible
changes, simple and proliferate DR. 30 subjects comprised a control group. The Ops was tested
under International Society for Clinical Electrophysiology of Vision protocol. Results: The
summed amplitude of Ops and its wavelets reduced gradually with the development of diabetic
retinopathy. There were differences in the summed amplitude of Ops and amplitude of Op2 in the
group with no visible changes compared to simple DR. There were differences in the amplitude
of Op1 and Ops in the control group, the group with no visible changes from simple and
proliferate DR .There were different in the amplitude of Op2 and summed amplitude of in
proliferate DR from group no visible changes, simple DR and the control group. Conclusions:
The summed amplitude of Ops and the amplitude of Op2 reduced in pre-clinical stage are
sensitive and objective index of early diagnosis of DR. The summed amplitude of Ops is
associated with the development of diabetic retinopathy severity level.
136.
HYPOBARIC HYPOXIA INHIBITS SPERMATOGENESIS IN RATS. Weigong Liao
1
, Yuqi
Gao
1
, Mingchun Cai
1
, Jian Chen
1
, Yi Wu
1
. Department of Pathophysiology and High Altitude
Physiology, Third Military Medical University, Chong
1
.
Objective: This study examined the effects of hypobaric hypoxia on the spermatogenesis in
rats. Methods: Adult male Wistar rats were divided into four groups: control group raised at sea
level; 5d, 15d and 30d hypoxic groups raised in a hypobaric chamber stimulating 5000m altitude
for 5 days, 15days and 30days respectively. Flow cytometry was used to detect the DNA content
of rat spermatogenic cells. The germ cells apoptosis was assayed by using TUNEL method. The
spermatogenesis was evaluated by morphology. Results: Five to thirty days hypobaric hypoxia
exposure significantly reduced the tetraploid cell populations (approximately 28%) compared
with control group (P<0.01). After being exposed to hypoxia for 30d, the ratio of haploid and
diploid cell populations was reduced by 25% compared with control (P<0.05); Proliferation index
of 15d (52.3±2.1%) and 30d hypoxic groups (50.7±1.3%) were significantly lower than that of
the control group (62.2±1.5%)(P<0.05). The apoptosis of spermatogonia and spermatocytes
increased after being exposed to hypoxia for 5d, 15d and 30d. The testicular interstitial edema,
occasional necrosis and degenerative changes in testicular germ cells were found in hypoxic rats.
Conclusion: Hypobaric hypoxia inhibits the spermatogenesis in testis, by decreasing the tetraploid
spermatogenic cells (primary spermatocyte). The apoptosis of primary spermatocytes and
spermatogonia, occurred under hypoxic conditions, may contribute to the loss of tetraploid cell
populations. (By grant of NSFC 39730190 and 30393131)
137.
FOOD CHOICES FOCUSING ON CARBOHYDRATE AND FAT CONSUMPTION AT FIVE
ALTITUDES ON A CLIMBING EXPEDITION TO MOUNT EVEREST. Julie Ann Lickteig
1
,
