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We examined the effect of a nitric oxide (NO) quencher, stroma-free human hemoglobin A ( ${\rm HbA}_{0}$; 0.01, 0.05, 0.1, 0.2 g/kg), on the blood flow measured using the Doppler flow technique, tumor oxygen pressure ( $p{\rm O}_{2}$) and the diameter of the arterioles using R3230Ac mammary adenocarcinoma as the tumor model. In female Fischer 344 rats with 1-cm-diameter tumors implanted in the lateral aspect of the left quadriceps, intravenous infusion of 0.1 and 0.2 g/kg ${\rm HbA}_{0}$ decreased both central tumor and peripheral tumor blood flow by 20-30% (P < 0.05). Tumor $p{\rm O}_{2}$ decreased 28% with 0.2 g/kg ${\rm HbA}_{0}$, from 15 mm Hg (baseline) to 11 mm Hg at 10 min (P = 0.02). Although 0.2 g/kg ${\rm HbA}_{0}$ increased blood flow 55% in the left quadriceps muscle proximal to the implanted tumor (P < 0.05), ${\rm HbA}_{0}$ had little effect on blood flow in right quadriceps muscle with no tumor implanted, and increased right quadriceps $p{\rm O}_{2}$, from 21 mm Hg (baseline) to 23 mm Hg at...

A study of trends in maternal mortality from 1963 to 1992 in North Carolina shows that during the period 1973-1977, when legal abortion first became available, the maternal mortality ratio (maternal deaths per 100,000 live births) for deaths related to induced abortion was almost 85% lower than the ratio during the previous five-year period. The decrease in abortion-related mortality had a substantial impact on the overall maternal mortality ratio during this period, accounting for about 46% of the total decline in maternal deaths. After 1977, the maternal mortality ratio for induced abortion declined to less than one death per 100,000 live births, while the mortality ratio for all other obstetric causes leveled off at about 10 deaths per 100,000 live births.

Several herbicides were evaluated for control of honey mesquite (Prosopis glandulosa Torr.) and huisache [Acacia farnesiana (L.) Willd.] using a tractor-mounted carpeted roller. Foliar sprays of picloram + 2,4,5-T at 0.28 + 0.28 and 0.56 + 0.56 kg/ha were included for comparison. When applied by carpeted roller, picloram at 60 g/L killed about 40% of the honey mesquite plants whereas 120 g/L killed 63 to 83% of the plants after 2 years. Clopyralid at 60 or 120 g/L killed 65% or more of the plants. Mixtures of picloram + clopyralid (1:1) at 30 + 30 g/L killed 53 to 73%, whereas 60 + 60 g/L killed 93 to 98% of the honey mesquite. Clopralid + triclopyr (1:1) 30 + 30 g/L killed 48 to 58% of the plants, while 60 + 60 g/L killed 80 to 95%. Picloram + 2,4,5-T (1:1) applied by the carpeted roller was usually more effective than foliar sprays of picloram + 2,4,5-T. For huisache, picloram, clopyralid, or picloram + clopyalid at a total of 60 or 120 g/L killed 60% or more of the plants after 1 year. Picloram + clopyralid at 60 + 60 g/ L applied in 1983 and 1984 killed 92% or more of the huisache. Picloram + 2,4,5-T at 60 + 60 g/L killed 73 to 83%, but foliar sprays of picloram + 2,4,5-T were sometimes ineffective. Glyphosate, dicamba, triclopyr and 2,4,5-T applied alone reduced the canopy of honey mesquite and huisache but usually killed few plants. Honey mesquite was controlled from spring applications, whereas, summer and fall treatments controlled huisacbe.

Herbicides were applied by a truck-mounted sprayer and airplane to stands of mixed brush in East Texas. Mixtures of 2,4,5-T + picloram gave the best brush control. Picloram was the best individual chemical but failed to kill white ash (Fraxinus americana L.), saw greenbriar (Smilax bona-nox L.) and redbay (Persea borbonia (L.) Spreng.) Picoloram only partially controlled American holly (Ilex opaca Ait.), blackgum (Nyssa sylvatica Marsh.), flowering dogwood (Cornus florida L.), red maple (Acer rubrum L.), oaks (Quercus spp.), and yaupon (flex vomitoria Ait.). Dicamba, isocil, bromacil, and mixtures of 2,4,5-T had intermediate activity. Paraquat and diquat were least effective for killing woody species. Dense grass stands occurred within 2 years after treatment where the brush had been controlled.