Large Number Of Blood Samples Research Articles

Semi-automated high-performance liquid chromatographic determination of cyclosporine A in whole blood using one-step sample purification and column-switching

A highly sensitive and semi-automated high-performance liquid chromatographic method, utilizing acetonitrile protein precipitation and column-switching, is described for the determination of cyclosporine A in whole blood. Following a rapid manual acetonitrile treatment of the blood samples, the supernatant is loaded automatically onto a 5-μm high-speed protein separation column without any further clean-up operations. The fraction containing cyclosporine A is switched to a 3-μm C 18 reversed-phase high-speed column by a microprocessor-controlled column-switching unit for final separation and detection by absorption at 214 nm. Minimal sample handling and efficient separation resulted in a high recovery (75 ± 3%) of cyclosporine A from blood and a detection limit as low as 2 μg/l with a highly reproducible and linear response up to 2500 μg/1 using 0.5 ml of sample. A separation cycle including regeneration of the first column is finished in 15 min, and this system was used continuously for ca. 1000 blood samples from heart, liver, kidney, pancreas and bone marrow recipients without change in separation parameters or material replacement. The method described allows accurate and very fast daily routine monitoring of cyclosporine A in large numbers of blood samples from transplant recipients.

Control of haemoglobin switching by a developmental clock?

The pattern of haemoglobin production changes at the embryonic, fetal and postnatal stages of human development, reflecting the expression of different globin genes in both the alpha-like and beta-like gene clusters. Recent studies have identified alterations in the state of DNA methylation and sensitivity to nuclease digestion associated with developmental expression of the globin genes in red blood cell precursors, but the mechanism initiating these changes remains unknown. Despite the screening of large numbers of blood samples from newborn infants, no mutants have been found which affect the timing of these changes (with one possible exception involving a chromosomal translocation), thus necessitating alternative approaches to analysing the cellular basis for the timing of haemoglobin switching. Although many mechanisms are possible, the initiation of the switch from fetal to adult haemoglobin could be regulated essentially either by a developmental clock inherent to haematopoietic stem cells or by an inductive environment, and in an attempt to distinguish between these possibilities, we have transplanted sheep fetal haematopoietic tissue into adult animals. Although previous experiments of this type produced conflicting results, the accumulated results presented here demonstrate that the pattern of haemoglobin production after transplantation is determined largely by the gestational age of the fetal donor cells.

A modified capillary test using 4% ficin.

A capillary technique is described for economical Rh-phenotyping of large numbers of blood samples using diluted antisera and 4% ficin solution. This system is no more time consuming that conventional tube techniques, since enzyme premodification of the cells is not required.

A Simple Gas Chromatographic Method for Routine 1-Tetrahydrocannabinol Analyses of Blood and Brain

A rapid, sensitive, and specific method Is presented for the quantification of A'-tetrahydrecannabinol In 1 ml of whole blood or in 0.5 g of brain tissue. The method is particularly suitable for routine toxicological analyses of large numbers of blood samples and may be done with most gas chromategraphs equipped with alkali thermionic or alkali flame ionization detectors. The cannabinoids are detected as their dlethyl phosphate esters, and detection limits are approximately 0.5 ng/ml of blood and 10 ng/g of brain.

Comparative studies of the ethynyl estrogens used in oral contraceptives: III. Effect on plasma gonadotropins

Twenty-one-day treatment cycles of ethynylestradiol or mestranol at dosages of 50 to 100 μg per day were administered to 191 normal volunteer women for six cycles, followed by six cycles of this estrogen treatment combined with 2.5 mg. of norethindrone acetate, 2 mg. of megestrol acetate, or 0.5 mg. of norgestrel. The drugs were prepared to insure uniform bioavailability. Plasma FSH and LH were determined by radioimmunoasay during the last week of medication intake in each cycle. In another study, a large number of blood samples were obtained at various times during the menstrual cycle from women using IUD's (as a control population) and from women who had been taking oral contraceptives regularly for 5 to 12 years. With the various estrogen treatments, the median FSH level showed no change at any estrogen dose at the end of the first cycle. From the second cycle on, a stable, dose-related fall was obtained with the 80 or 100 μg per day doses. The addition of any of the three progestins caused a prompt, stable, further fall in FSH level. By contrast, the median LH level rose in the first cycle with all estrogen regimens, and then fell progressively in a dose-related fashion in cycles 2 to 6. The addition of a progestational agent also caused a further prompt and stable fall in LH during cycles 7 to 12. Except for a minimal indication of greater LH suppression by ethynylestradiol as compared to mestranol at 50 μg per day, all other indices and dosages showed ethynylestradiol and mestranol to be essentially equipotent under these experimental conditions. Long-term administration of oral contraceptives produced a comparable degree of gonadotropin suppression. There was a suggestion of slightly less FSH suppression with agents using 50 to 75 μg per day of estrogen than from those with 100 μg per day. Both in normal controls (IUD cycles) and in cycles under chronic treatment with oral contraceptives, pulses of both FSH and LH were seen with some frequency, at times distant from the “periovulatory” period. The significance and origin of these random FSH and LH pulses is unknown.

The occurrence of haemoglobin-J (Tongariki) and of thalassaemia on Karkar Island and the Papua New Guinea mainland.

The known α-chain variant Hb-J (Tongariki) was found to occur at relatively high frequency in several villages on the island of Karkar, about 15 km from the New Guinea mainland. The same variant was also found in an adjacent coastal region of the mainland, but not in a large number of blood samples collected in the Central Highlands. This is the third Pacific location in which Hb-J (Tongariki) has been found, and this variant may be a useful genetic marker for the study of Melanesian populations. Hb-J (Tongariki) is a ‘high-level ’ α-chain variant; its mean proportion in heterozygotes is 41 %. Three homozygotes were found in which Hb-J (Tongariki) and Hb-J 2 (α J 2 δ 2 ) were the sole major and minor constituents respectively. These findings are of interest in relation to current studies on the possible duplication of the human α-chain gene locus.

Determination of 17-oxosteroid sulphates in human plasma

A quick method is described for the determination of total 17-oxosteroid sulphates in human plasma. This method is suitable for the screening of large numbers of blood samples. The resolution of the plasma extracts in thin-layer chromatography is illustrated. Results obtained in healthy individuals and cancer patients are given.

Comparison of acid-base status values calculated electronically and determined according to the Singer-Hastings nomogram

Abstract 1. 1. In analyses of the acid-base status by the Astrup equipment the p CO 2 , total CO 2 , standard bicarbonate and actual bicarbonate values are commonly determined graphically using the Singer-Hastings curve nomogram. 2. 2. A method is described to determine the data of the acid-base status arithmetically . By this it becomes possible to use an electronic computer for calculating. 3. 3. This method is recommended: 1. for the calculation of a large quantity of values, 2. when no urgent therapy depends on early results. 4. 4. The electronically calculated values are comparable with those determined from the nomogram. The differences for the single parameters are at the utmost between 0.8 and 2.4% of the normal data for adults; so they lie within the limits of accuracy for the values determined by nomogram. 5. 5. The use of an electronic computer saves time when handling large numbers of blood samples; it involves less sources of error. 6. 6. The calculated data may be evaluated statistically by the computer and may be transmitted to punched cards or tabulated mechanically without additional time loss.

In vivo Intestinal Absorption of L-Alanine in Irradiated Rabbits

The effects of ionizing radiation (60Co) on intestinal absorption of L-alanine were studied by means of an in vivo technique permitting measurement of radioactivity in a large number of blood samples taken from the portal and femoral veins of albino rabbits following duodenal injection of 20 µCi of L-alanine-14C. The experiments were carried out 4 days after irradiation. The curves so obtained show a very rapid rise and fall of activity in the portal vein under all three experimental conditions (control, 300 r, and 600 r). Absorption was practically completed 50 minutes after the injection of this amino acid. Absorption trends were similar and no significant difference was observed between those of irradiated and unirradiated animals. At the doses used, histological examination 4 days after irradiation showed slight effects on the absorbing cells of the intestine.

A Survey of Brucellosis in White-Tailed Deer in Missouri

Previous studies of brucellosis (also known as Bang's disease and contagious abortion) in big-game animals have revealed its occurrence in bison (Creech, 1930; Rush, 1932; Tunnicliff and Marsh, 1935), in elk (Allred, 1947; Lee and Turner, 1937; Murie, 1951; Rush, op. cit.; Tunnicliff and Marsh, op. cit.), in moose (Fenstermacher and Olsen, 1942; Jellison, Fishel and Cheatum, 1953), and in whitetailed deer (Bolin, Goldsby, Rheault and Eveleth, 1949). The few mule deer and pronghorn antelope tested were not infected with brucellosis (Bolin and Eveleth, 1951; Ryff, 1951). Only in bison has a high incidence of brucellosis been reported (Tunnicliff and Marsh, op. cit.), and only in elk has the disease been reported to have had a deleterious effect on herd productivity (Murie, op. cit.). Brucellosis appears to be rare in white-tailed deer. Blood sera from 436 white-tailed deer from North Dakota were tested by Bolin, Goldsby, Rheault and Eveleth (op. cit.). Only one animal was found to be infected. They also report the detection of one brucellosisinfected deer among four tested by a private veterinarian in North Dakota. In a later study (Bolin and Eveleth, op. cit.), blood sera from 70 more whitetails were tested and found negative for brucellosis. Fenstermacher, Olsen and Pomeroy (1943) tested blood sera of six Minnesota whitetails for brucellosis and tularemia, with negative results. Recent work in Ohio (Edgington, 1951) revealed no brucellosis in the 210 deer tested there. Whitlock (1949) found no brucellosis in whitetails in Michigan. While the results of these surveys were reassuring, the possibly serious effects brucellosis might have on deer herd productivity, and the potential danger of spreading the disease, if it was present, to domestic livestock, made it important that we ascertain whether our deer were infected with brucellosis. Recent increases in the size of both the deer and cattle herds in Missouri made the problem an immediate one. Blood samples have been collected from white-tailed deer (Odocoileus virginianus) killed during the past four deer seasons (1950-1953) in Missouri. Samples were collected by Conservation Commission biologists from deer brought to deer-checking stations by hunters. Nearly all deer are eviscerated when brought to checking stations, so blood can be obtained only from the visceral cavity of freshlyeviscerated deer. No attempt was made to collect blood from deer whose visceral cavities were obviously contaminated with intestinal contents, urine or water, and in many cases no blood was available. In spite of adverse conditions, a large number of blood samples was collected each year, and, although most samples showed some degree of hemolysis, nearly all were in satisfactory condition for testing. During the four-year study, blood samples were collected from 1,019 deer, killed in 17 counties, mainly in southern and east-central Missouri. A total of 996 samples yielded sufficient sera in adequate condition to test. These samples were collected from 352 adult males, 234 adult females, 153 fawns, and 257 deer of unknown age, about half of which were females. All blood samples were delivered to the State and Federal Cooperative Bang's Testing Laboratory in Jefferson City, Missouri, where they were centrifuged and the sera tested for brucellosis. Deer serum was tested exactly as cow serum is, using the standard plate agglutination test, with Bureau of Animal Industry Brucella abortus antigen. In 1950, 1951, and 1952, all sera were tested first at a dilution of 1 to 50. Where clear-cut negative results were not obtained, sera were centrifuged a second time and tested at dilutions of 1:50, 1:100, 1:200 and 1:400. In 1953 sera were tested first at a 1:42 dilution. If further testing was indicated, sera were again centrifuged and tests were set up at dilutions of 1:50, 1:100 and 1:200.

Blood Technics for Chickens

AN ATOMIC Energy Project undertaken at this Laboratory involved numerous blood determinations made over a two-year period and, prelininary to the actual work, a comparative study of technics suitable for avian blood was made. The technics selected have been applied to over 2,500 blood samples and have given results which appear to be reliable. During the period when work was in progress, inquires were received con-concerning the technics which had been selected and the development of modifications which had been found useful. In order to make this information generally available, a report covering the following subjects has been prepared: (1) description of a unit tray for handling large numbers of blood samples, (2) determination of avian hemoglobin, (3) accuracy of hemoglobin pipettes, (4) hematocrit with the Van Allen pipettes, (5) composition of the buffy coat, (6) a shaker for red blood cell pipettes, (7) variability in samples of Wright’s stain, …