Search

1. Rhnull human erythrocytes lack all of the antigens of the Rh and LW blood group systems and have abnormal shape and an increased osmotic fragility. In this paper two murine monoclonal antibodies raised against intact human erythrocytes were used to investigate further the abnormalities in these cells. BRIC 125 reacts weakly with Rhnull erythrocytes and BRIC 69 does not react at all. The results showed that BRIC 125 reacts with a component of Mr 47,000-52,000 which has a substantial content of N-glycans. In contrast, BRIC 69 reacted with a band of Mr 31,000 together with a very diffuse band of Mr 35,000-52,000. Treatment of BRIC 69 immunoprecipitates with endoglycosidase F/peptidyl-N-glycosidase F resulted in the loss of both BRIC 69 reactive components and the appearance of a new band of Mr similar to that of the Rh(D) polypeptide. 2. BRIC 125 had a broad reactivity with cells in peripheral blood, whereas the reactivity of BRIC 69 was confined to erythrocytes. BRIC 125, but not BRIC 69, reacted with human kidney tissue and bound to endothelium in peritubular capillaries, arteries and veins as well as the epithelial tissue of distal tubules. BRIC 125 stained haemopoietic cells, foetal hepatocytes and megakaryocytes in foetal liver and sinusoidal cells, hepatocytes and portal tracts in adult liver. In contrast, BRIC 69 reactivity was confined to haemopoietic cells in foetal liver. The BRIC 125 epitope has a wide tissue distribution, suggesting the occurrence of a related group of polypeptides which have a general functional role on cell surfaces. 3. Rhnull erythrocytes are deficient in at least four different membrane polypeptides.

Pastures of Sarasota stargrass, Callie Bermuda grass and Bigalta limpograss were evaluated in comparison with the currently recommended forage cultivar in South Florida, Ona stargrass, by year-long grazing with yearling steers. Pastures, 2 ha in size, were divided into four .5 ha units and rotationally grazed at initial stocking rates of five 200 kg steers/2-ha pasture. A “put-and-take” stocking system was used to adjust animal numbers beyond the initial stocking rate to maintain relatively uniform levels of standing forage. Differences in individual animal performance were not obtained among grasses over a 3-yr period. However, carrying capacity during the warm season differed (P<.01) with 975, 969, 829 and 739 animal days of grazing for Sarasota, Ona, Callie and Bigalta, respectively, during this 230-d period. Beef production of 619, 607, 513 and 532 kg/ha on pastures of Sarasota, Ona, Callie and Bigalta, respectively, differed only at the P=.18 level, but this is probably of economic importance. Average daily gain was closely correlated (r=.419 for Bigalta to r=.577 for Ona with P<.0001 for each of the four grasses) with forage in vitro organic matter digestibility (IVOMD). However, equations involving forage IVOMD and forage quantity did not account for much more of the variation in animal performance than did IVOMD alone.

Angus (A), Brahman (B), and Charolais (C) cattle were straightbred and reciprocally crossed in all possible 2-breed combinations. An average of 91 progeny were produced in each of the nine subclasses. The traits studied included weaning age, condition score, 205-day weight and weaning weight.Overall least squares means for calf age at weaning, condition score, 205-day weight and weaning weight were 222 days, 9.6, 194 kg and 207 kg, respectively.Breed of sire effects were significant (P<.01) for all traits. Weaning age was similar for calves sired by Angus and Charolais bulls (225 vs227 days) and lowest for those sired by Brahman (215 days). Condition scores were highest for calves sired by Angus (9.9) and Charolais (9.6) bulls and lowest for Brahman (9.4) sired calves. Average weaning and 205-day weights were highest for Charolais sires with calves by Brahman and Angus sires being similar. Breed of dam effects were significant (P<.01) for all traits except conditions score of calves. Angus dams weaned the oldest calves, 230 days, compared with 220 and 218 days respectively, for Charolais and Brahman dams. Weaning and 205-day calf weights were highest for Charolais dams with Brahman dams next in order and Angus dams lowest.Significant (P<.01) breed of sire × breed of dam interactions occurred for condition score, 205-day weight, and weaning weight of calves. Crossbred progeny excelled purebreds for all production traits (P<.01), averaging 9.8 vs9.2; 199 kg vs185 kg; 211 kg vs198 kg, respectively for condition score, 205-day weight, and weaning weight. Heterosis levels for reciprocal AB, BC and AC crossbred progeny, respectively, were 9.8, 5.5 and 5.3% for condition score; 13.1, 7.0 and 2.8% for 205-day weight; and 12.2, 7.1 and 2.1% for weaning weight.

Strontium-90 is now present in the skeletons of all living persons throughout the world as a result of nuclear detonations. Since this isotope is nonuniformly distributed within the adult skeleton, it is necessary to define this distribution in order to more adequately estimate the resultant radiation hazard as well as to evaluate and compare data from a variety of bones of different individuals. The principal bones from many cadavers were analyzed. While some skeletons were assayed very extensively, the bulk of the investigation centered on rib, vertebrae and long bone shaft. In the case of adults, an aliquot of the total body skeleton was also analyzed in each case. In adults the strontium-90 concentration per gram calcium in vertebrae, rib and long bone shaft is 1.8, 1.1 and 0.5 times skeletal average respectively. In newborns and young children, the distribution is much more uniform although these data are more limited. These findings together with the fact that stable strontium is uniformly distributed throughout the adult skeleton show that the nonuniformity of strontium-90 is a temporal function of changing diet. If radiation damage from strontium-90 is a threshold phenomena, the distribution is of particular importance since the highest local concentration areas will first exceed the threshold. If the damage is nonthreshold in character, the distribution is still of some significance since some areas (e.g. bone marrow) are presumably more susceptible to radiation damage than other areas.

A study was made of the effect of phosphorus applied as fertilizer in the form of super, super+lime, rock, colloidal, triple and basic slag to pangolagrass pastures on the phosphorus, calcium, hemoglobin and hematocrit composition of the blood of grazing cows from 1950 to 1965. The effects of four seasons of the year and age of cattle on these substances were studied.Over-all average phosphorus concentration for the control cows was 4.3, compared to 5.1 mg. per 100 ml. of plasma for the six phosphate treatment groups. September and December were generally higher than those in March and June (P<0.01). Heifers at 1 yr. and cows at 15 to 17 yr. of age had approximately 1 mg. per 100 ml. more (P<0.01) phosphorus in the plasma than intermediate age cows.Calcium was not influenced by the phosphatic treatments. In March the average value of all cows was 9.8 compared to 11.3 mg. per 100 ml. plasma in September (P<0.01). Values for calcium decreased (P<0.01) from 11.0 to 11.5 mg. per 100 ml. plasma up to 6 yrs. of age, to 8.9 to 9.9 during the period of 11 to 17 yr. of age.Hemoglobin values did not vary significantly due to phosphorus fertilizer treatments of the pastures. Twelve grams of hemoglobin per 100 ml. blood was found in March compared to 13.0 gm. during December (P< 0.01). Values of 12.3 to 13.3 gm. per 100 ml. were observed during the first 9 yr. of age, but from 10 through 17 yr. of age values decreased to 11.3 to 12.3 gm. per 100 ml. blood (P<0.05).Average hemacrit values ranged from 48.1 for cows on colloidal to 52.1 for animals in the superphosphate treatment group (P<0.01). Values obtained in June and September were lower (P<0.01) than those in December and March. Hematocrit values for cows 1 to 8 yr. old ranged from 50 to 54% compared to values of 46 to 50 during 9 through 17 yr.of age (P<0.05).

The 6150-Å laser transition in Hg ii generated in a pulsed hollow cathode discharge, has been studied under high resolution. The line shows structure corresponding to the expected shifts from the even isotopes, with a spacing of approximately 26.5 mK (800 Mc/sec) between adjacent components, in rough agreement with earlier results. The fullwidth at half-maximum of each component has been measured as 500 Mc/sec. The wavelength has been compared to that of thorium secondary wavelength standards and it has been determined that the vacuum wavelength of the ^202Hg component is 6151.1650 Å. The possibility of the mercury hollow cathode laser as a laboratory wavelength standard is pointed out.

The number of calves weaned relative to the number of cows exposed to bulls is one of the most important economic traits in beef cattle production. High costs of production make it of the utmost importance to achieve the highest weaning rate possible with the forage resources available. Thus, it is important to assess the productivity of various breed groups in alternative production systems in order to design economical production programs. Little information is available on the comparative reproductive behavior of Brahman, European-origin and crossbred cattle under contolled environmental conditions imposed by nutritional or management regimes.At the time the trial was initiated, information was not available on the comparative reproductive performance of different breed groups. Reliable data on the reproductive rates on native versusimproved pastures in Florida were unavailable. Reports from Florida (Koger et al., 1962; Gonzales-Padilla et al., 1969), Texas (Cartwright et al., 1964) and Louisiana (Turner, Farthing and Robertson, 1968) have indicated heterosis for weaning rate in Brahman-British crossbred cows.