Normal Median Values Research Articles

ATYPICAL PRECIPITATION MEASURES: COMPARISONS ALONG AN ENVIRONMENTAL GRADIENT, CENTRAL UNITED STATES

Similarities and differences among 11 precipitation measures from 11 central U.S. sites are described. Sites are arrayed along transects that cross a longitudinal environment gradient. Nine derived (precipitation days, hours, events, duration, traces to precipitation hours, four intensity ratios) and two measured (precipitation amounts, trace occurrence) variables are used. Hourly values for 10 growing seasons comprise the data. Measures are compared under normal, wet, and dry conditions. Inclusion of trace occurrences on comparisons is noted. Normal condition median values decrease westward; significant similarities exist among stations for all variables; trace inclusion raises median precipitation days and event numbers at western stations. Under dry conditions, medians are lower for all variables but overall sample characteristics are similar to normal conditions; trace data inclusion decreases contrasts with normal conditions; trace data inclusion (exclusion) increase (decreases) twofold between wet a...

Congenital malformation syndromes and elevation of amniotic fluid alpha-fetoprotein.

Fetal malformations may introduce complications of maternal pregnancy. A polyhydramnios represents one such complication during pregnancy. We want to report five abnormal pregnancies which were marked by acute polyhydramnios and/or premature labor due to an amniotic band syndrome associated with cerebral herniation in two cases, malignant oral teratoma in one case, bilateral cystic hygromas associated with generalized fetal hydrops in one case, and multiple internal malformations in one case alpha-fetoprotein (AFP) values between the 25th and 34th week of gestation were elevated 3.5 to 44 times the normal median value. Since all fetuses showed severe malformations incompatible with life our observations indicate the necessity to determine AFP in cases of acute polyhydramnios independent of the week of gestation. Conversely, elevated AFP levels in amniotic fluid obtained during prenatal diagnosis in the 16th week of gestation may also suggest rare fetal malformations outlined above.

The ultrasound diagnosis of hydatidiform mole and coexistent fetus associated with elevated maternal serum alpha feto protein

A 36-year-old primigravida was seen in the antenatal clinic. At this stage gestation was ten weeks by dates but the uterus was slightly larger on examination. Four weeks later the patient was found to be hypertensive (BP 180/120) and had experienced persistent vomiting for two weeks. On ultrasound scan a large placenta containing vesicles was demonstrated, and, lying low down in the uterus, a viable fetus of approximately 15 weeks gestation was visible. The maternal serum α feto protein level (AFP) at this stage was 164 μg/1 (normal median value at 15 weeks 31 μg/1 Median × 2.5 78 μg/1. Liverpool University). In view of these findings the patient was admitted for termination. Post mortem revealed a 15-week fetus with a large spina bifida defect. The placenta showed hydropic changes consistent with hydatidiform mole.

Further studies on the total-energy hypothesis

Previous studies have established that in the chinchilla, the “critical level” for a 220-min continuous exposure to 700–2800-Hz noise is 105 dB SPL, in the sense that such an exposure produces neither significant permanent threshold shift (PTS) nor an increase in missing hair cells (MHC) over the normal median value of 50 to 100. However, 108 dB produced an MHC count of over 400, and 111 dB generated not only a 700-MHC count but also a 10-dB PTS at 2 kHz. Finally, 114 dB produced 1500 MHC and a 30-dB PTS at 2 kHz. Breaking the 114-dB exposure down to 22 10-mix exposures administered twice weekly for 11 weeks reduced the MHC count to just over 300, with negligible PTS at 2 kHz, implying a reduction in “effective exposure level” of about 7 dB. Two more related exposures are reported here. A continuous 2200-min (1.5-day) exposure at 102 dB SPL produced 950 MHC and l0 dB of PTS. which are values that would be predicted on the basis of the total-energy concept—i.e., equivalent to 112 dB for 220 min. On the other hand, a 440-min exposure at 114 dB SPL using a pattern of 30 s on, 30 s off (cumulative exposure 220 min), also produced essentially the same effect as 112 dB for 220 min (800 MHC, 20 dB of PTS). The results thus affirm the validity of the total-energy principle in assessing single uninterrupted exposures to noise, as in acoustic trauma, but also indicate that rest periods. even short ones, reduce the permanent effect of repeated exposures. [Work supported by NIH grant NS 12125.]