Molecular characterization of the human macrophage mannose receptor: demonstration of multiple carbohydrate recognition-like domains and phagocytosis of yeasts in Cos-1 cells

The macrophage mannose receptor is an integral membrane protein expressed on the surface of tissue macrophages. After ligation of mannose-rich glycoconjugates or pathogens, the receptor mediates endocytosis and phagocytosis of the bound ligands by macrophages. The cDNA-derived primary structure of the mannose receptor predicts a cysteine-rich NH2-terminal domain, followed by a fibronectin type II region. The remainder of the ectodomain is comprised of eight carbohydrate recognition-like domains, followed by a transmembrane region, and a cytoplasmic tail. Transfection of the mannose receptor cDNA into Cos-I cells is necessary for receptor-mediated endocytosis of mannose-rich glycoconjugate as well as phagocytosis of yeasts. Deletion of the cytoplasmic tail results in a mutant receptor that is able to bind but not ingest the ligated pathogens, suggesting that the signal for phagocytosis is contained in the cytoplasmic tail.

Biochemical measurement in cord blood as an indicator of neonatal maturity

Neonates were categorized by gestational scoring (G. Score) using physical and neurological signs, into two groups: TERM and preterm (PRE) using a score corresponding to approximately 38 weeks of gestation as the dividing point. Cord blood concentrations of alphafetoprotein (AFP), fetal hemoglobin (HGF), prealbumin (PALB), creatinine (CRE), and pseudocholinesterase (PC) were determined. The CRE, AFP, and HGF were divided by birthweight in grams (WT) to give three additional markers: CRE/WT, AFP/WT and HGF/WT. Strong Pearsonian correlations between CRE/WT, AFP/WT, and HGF/WT, and G. Scores in the PRE group were obtained. Histograms of AFP/WT and HGF/WT values gave non-Gaussian distributions and resulted in the clear separation of a group of extremely premature infants from the rest of the population. The plots also revealed substantial separation between the TERM and PRE groups. The CRE/WT was predominantly Gaussian, with separation of a group of neonates including the six very preterm infants. It is concluded that CRE/WT, AFP/WT, and HGF/WT have the greatest potential as maturity markers, while PC and PALB have little if any potential.

Detection of individual fluorescently labeled reovirions in living cells

Reovirus serotype 1 (Lang) can be conjugated with rhodamine B or fluorescein isothiocyanate in a way that preserves viral infectivity. We have used epifluorescence microscopy to detect individual virions bound to the surface of cells and to follow in real time the early stages of reovirus infection in living cells. Following uptake of the virus into endocytic vesicles, the movement of these vesicles can be observed readily. The vesicle movement is inhibited by nocodazole or colchicine, consistent with previous findings that the movement of intracellular vesicles is often microtubule-based.

Critical care nurses' attitudes toward, concerns about, and knowledge of the acquired immunodeficiency syndrome

Two samples of critical care nurses (from a secular teaching hospital and a religious-affiliated community hospital, respectively) were compared on their attitudes, concerns, and knowledge regarding the acquired immunodeficiency syndrome (AIDS). Nurses from the teaching hospital had significantly (p = 0.003) more favorable attitudes toward patients with AIDS than did the community hospital nurses. Modal response in each group for perceived risk of acquiring AIDS from patients was 1 chance in 10,000. If given a choice, a sizable percentage in both the teaching (45%) and the community hospital (65%) groups would refuse to care for patients with AIDS. Those indicating preference for refusing showed significantly higher levels of concern and significantly less favorable attitudes than the others. Knowledge about AIDS was high, with means in each group exceeding 14 out of 16 possible points. Implications for nursing practice are discussed.

Recovery of an epitope recognized by a novel monoclonal antibody from airway lavage during experimental induction of chronic bronchitis

Prolonged exposure of dogs to high concentrations of SO2 gas results in a syndrome with many of the characteristics of human chronic bronchitis, including cough and chronic mucous hypersecretion as well as airway obstruction. We developed and used a novel monoclonal antibody, GB-4B, raised against epithelial glycoprotein isolated from human hypersecretory mucus to probe airway lavage samples from dogs before and during prolonged exposure to SO2 gas. There were relatively low mean titers of the epitope recognized by GB-4B in airway lavage fluid as evidenced by enzyme-linked immunosorbent assay before exposure to SO2 gas. After 25 to 50 wk of SO2 exposure, the dogs showed a significant increase in pulmonary resistance and there was a significant increase in the titer of the epitope in the airway lavage fluid. Using the same antibody immunohistochemical analysis of airway tissues from SO2-exposed dogs revealed patchy staining of the mucous glands and airway secretory cells and dense staining along the airway surface; airway tissue from control dogs and one SO2-exposed dog whose lavage fluid did not contain the epitope showed little or no staining. These data demonstrate that similar mucin epitopes appear in airway lavage fluid under hypersecretory conditions in both animals and humans. The epitope may have utility as a marker of chronic mucous hypersecretion.

The role of gap junctions in patterning of the chick limb bud

The role of gap junctional communication during patterning of the chick limb has been investigated. Affinity-purified antibodies raised against rat liver gap junctional proteins were used to block communication between limb mesenchyme cells. Co-injection of the antibodies and Lucifer yellow into mesenchyme cultures demonstrated that communication was inhibited almost immediately. When antibodies were loaded into mesenchyme tissue by DMSO permeabilization, [3H]nucleotide transfer was prevented for at least 16 h. Polarizing region tissue from the posterior limb bud margin causes digit duplications when grafted to the anterior margin. Quail polarizing region cells were loaded with gap junction antibody and grafted into chick wing buds. The antibody had no effect on growth or survival of the grafted cells. As very few polarizing region cells are required to initiate duplications, the number of polarizing region cells in the grafts was reduced by diluting 1:9 with anterior mesenchyme tissue. When either polarizing region or anterior mesenchyme tissue in the graft was loaded separately with antibody, there was little effect on respecification of the digit pattern. However, loading both tissues in the graft caused a significant decrease in duplications. This indicates that a major role of gap junctions in limb patterning may be to enable polarizing region cells to communicate directly with adjacent anterior mesenchyme. A role for gap junctional communication between anterior mesenchyme cells cannot be excluded. The results are discussed in relation to the role of retinoic acid as a putative morphogen.

Spontaneous pneumopericardium in an otherwise healthy full-term newborn

Neonatal pneumopericardium is usually a complication of mechanical ventilation in premature infants with respiratory distress syndrome. We report a full-term neonate who developed pneumopericardium after forceps delivery and mild asphyxia. The child was never ventilated and had no signs of parenchymal lung disease. The pneumopericardium resolved spontaneously. Although drainage of pneumopericardium is usually recommended, this may not always be necessary when there are no signs of cardiac tamponade.

Liquid-chromatographic monitoring of cytosine arabinoside and its metabolite, uracil arabinoside, in serum

This is a "high-performance" liquid-chromatographic method for quantifying the antileukemic drug cytosine arabinoside (cytarabine; 1-beta-D-arabinofuranosylcytosine; Ara-C), with a structural analog, 5-methylcytidine, as the internal standard. We used a C18 reversed-phase column and ammonium acetate (0.5 mol/L, pH 6.5) as the mobile phase, monitoring the column effluent at 280 nm. Tetrahydrouridine was present in the sample-collection tubes to inhibit conversion of cytosine arabinoside to uracil arabinoside. The standard curve is linear to 100 mg/L. Analytical recovery is 98%. Coefficients of variation for within-run and between-run imprecision were 2.0% and 4.3% at 20 mg/L and 2.7% and 2.7% at 80 mg/L, respectively. Assay sensitivity was limited by the amount of endogenous material in each patient's serum, making assay of a pre-infusion sample necessary for accurate calculations. In a trial patient population, the assay was shown to have potential for the detection of toxic concentrations in patients receiving high doses of Ara-C.

Liquid-chromatographic monitoring of cytosine arabinoside and its metabolite, uracil arabinoside, in serum

This is a "high-performance" liquid-chromatographic method for quantifying the antileukemic drug cytosine arabinoside (cytarabine; 1-beta-D-arabinofuranosylcytosine; Ara-C), with a structural analog, 5-methylcytidine, as the internal standard. We used a C18 reversed-phase column and ammonium acetate (0.5 mol/L, pH 6.5) as the mobile phase, monitoring the column effluent at 280 nm. Tetrahydrouridine was present in the sample-collection tubes to inhibit conversion of cytosine arabinoside to uracil arabinoside. The standard curve is linear to 100 mg/L. Analytical recovery is 98%. Coefficients of variation for within-run and between-run imprecision were 2.0% and 4.3% at 20 mg/L and 2.7% and 2.7% at 80 mg/L, respectively. Assay sensitivity was limited by the amount of endogenous material in each patient's serum, making assay of a pre-infusion sample necessary for accurate calculations. In a trial patient population, the assay was shown to have potential for the detection of toxic concentrations in patients receiving high doses of Ara-C.

Interference of common household chemicals in immunoassay methods for drugs of abuse

I report how some adulterants affect results for drugs of abuse in urine as measured by Roche RIA, Syva emit d.a.u., and Abbott TDx fpia (fluorescence polarization immunoassay) for the following drugs: amphetamines, barbiturates, benzodiazepines, cannabinoids, cocaine, opiates, and phencyclidine (PCP). Sodium chloride interfered negatively with all of these drugs when assayed by emit and caused a slight decrease in measured benzodiazepine concentration by fpia. Drug concentrations were also decreased by added H2O2 (emit: benzodiazepine), Joy detergent (emit: cannabinoid, benzodiazepines, PCP), NaHCO3 (emit: opiate; fpia: PCP), or NaClO [corrected] (emit, RIA, fpia: amphetamines, opiates, PCP; emit, fpia: cannabinoid; emit: benzodiazepines). False-positive results were caused by H2O2 (fpia: benzodiazepines) and Joy (RIA, fpia: benzodiazepine, cannabinoid; fpia: barbiturate, amphetamine). Sodium bicarbonate causes a suspiciously high pH in the urine, NaClO [corrected] an apparently low pH (using pH paper).

Interference of common household chemicals in immunoassay methods for drugs of abuse

I report how some adulterants affect results for drugs of abuse in urine as measured by Roche RIA, Syva emit d.a.u., and Abbott TDx fpia (fluorescence polarization immunoassay) for the following drugs: amphetamines, barbiturates, benzodiazepines, cannabinoids, cocaine, opiates, and phencyclidine (PCP). Sodium chloride interfered negatively with all of these drugs when assayed by emit and caused a slight decrease in measured benzodiazepine concentration by fpia. Drug concentrations were also decreased by added H2O2 (emit: benzodiazepine), Joy detergent (emit: cannabinoid, benzodiazepines, PCP), NaHCO3 (emit: opiate; fpia: PCP), or NaClO [corrected] (emit, RIA, fpia: amphetamines, opiates, PCP; emit, fpia: cannabinoid; emit: benzodiazepines). False-positive results were caused by H2O2 (fpia: benzodiazepines) and Joy (RIA, fpia: benzodiazepine, cannabinoid; fpia: barbiturate, amphetamine). Sodium bicarbonate causes a suspiciously high pH in the urine, NaClO [corrected] an apparently low pH (using pH paper).

Hemoglobin F: relationship to maturity measures in the neonate

The maturity of organ functioning is a key to predicting neonatal prognosis, particularly in preterm babies, and laboratory tests have the potential for providing better information than external exams. This approach was examined utilizing the fetal protein, HGB F. While HGB F itself does not correlate well with current measures of maturity, HGB F/WT was found to correlate very strongly, in a linear relationship with the gestational score (G. Score) obtained from a physical and neurological assessment of the neonate. This relationship was not affected by sex or race in our population. A cut-off value for HGB F/WT of 0.025 was chosen as the difference between mature and immature neonates and the value of the test using that cut-off was determined. Infants were classified as preterm or term based upon G. Score and gestational age (from the mother's last menstrual period) and were further classified depending upon whether the HGB F/WT value indicated a mature or premature infant. Utilizing predictive theory, the test was found to have a predictive value of 0.914 with an overall test efficiency of 0.967. These results indicate that this measurement has potential as a maturity marker in neonates.

Patterns of junctional communication during development of the early amphibian embryo

Cell-cell communication through gap junctions was examined in Xenopus laevis embryos between the 16-cell and early blastula stages using Lucifer Yellow, Fluorescein, lead EDTA and dicyanoargentate as probes of junctional permeability. Injections were made into cells whose position was identified with respect to the primary cleavage axis and the grey crescent. FITC dextrans revealed cytoplasmic bridges between the injected cell and its sister only. In the animal pole at the 16-cell stage at the future dorsal side of the embryo, Lucifer Yellow was frequently and extensively transferred between cells through gap junctions. At the future ventral side gap junctional transfer of Lucifer Yellow was significantly less frequent and less extensive. The asymmetry of transfer between future dorsal and ventral sides of the animal pole was more marked at the 32-cell stage. In the vegetal pole also at the 32-cell stage, a dorsoventral difference in junctional permeability to Lucifer Yellow was observed. At the 64-cell stage the transfer of Lucifer Yellow was relatively frequent between cells lying in the same radial segment in the animal pole; transfer into cells outside each segment was infrequent, except at the grey crescent. At the 128-cell stage, Lucifer transfer between future dorsal or future ventral cells in the equatorial region was infrequent. A high incidence of transfer was restored at the future dorsal side at the 256-cell stage. At the 32-cell stage, fluorescein was infrequently transferred between animal pole cells although lead EDTA moved from cell to cell with high, comparable frequency in future dorsal and ventral regions. Dicyanoargentate always transferred extensively, both at the 32- and 64-cell stages. Treatment of embryos with methylamine raised intracellular pH by 0.15 units, increased the electrical conductance of the gap junction and produced a 10-fold increase in the frequency of Lucifer Yellow transfer through gap junctions in future ventral regions of the animal pole at the 32-cell stage.

Comparison of Abbott TDx fluorescence polarization immunoassay, Sandoz radioimmunoassay, and high-performance liquid chromatography methods for the assay of serum cyclosporine

We have had the opportunity to compare the new FPIA method for the measurement of serum Cs to established assays. The technique used a precipitation step prior to the fluorescence polarization measurement. We compared serum HPLC and RIA to the FPIA procedure. The within run coefficients of variation were 7.2%, 9.5%, and 4%, respectively. Between run CVs were 8.0%, 12.2%, and 3.8%. The correlation coefficient for HPLC and both of the immunoassays was less than 70%, showing the influence of the different specificities of the techniques. Medical centers that have based patient care on the HPLC assay that measures only parent drug will have difficulty using an immunoassay that measures a combination of parent and metabolites. There was a good correlation (R2 = 0.93) between the two immunoassays indicating that those currently using the serum RIA for monitoring could, through careful correlation studies in their patient population, use the FPIA technique. The regression equation was as follows: serum FPIA = 1.27 serum RIA + 1.9. This indicates the higher bias of the FPIA measurements. The advantages of the FPIA assay are that 20 assays could be done in less than one hour. This is in contrast to the longer turnaround time of the standard Sandoz RIA procedure. The technical competence required to perform the assay is less than that needed to perform the current RIA procedure. The assay can be recommended for replacement of the serum RIA; however, a correlation of levels with clinical experience is necessary in view of the difference in values between RIA and FPIA.

Reduced gap junctional communication is associated with the lethal condition characteristic of DDK mouse eggs fertilized by foreign sperm

Communication through gap junctions was examined in 8-cell zygotes generated by fertilization of eggs of the DDK inbred strain of mice with spermatozoa of the C3H strain. These zygotes spontaneously begin to extrude cells at the late 16-cell stage and 95% die by the blastocyst stage. The transfer of Lucifer Yellow between cells of DDK/C3H zygotes that had not yet begun to express the defect was significantly slower than in DDK/DDK controls or in controls from other strains. Treatment with the weak base methylamine, to raise intracellular pH, speeded the transfer of Lucifer in all strains; transfer between cells of DDK/C3H zygotes became as fast as that between cells of control zygotes. DDK/C3H zygotes cultured in methylamine either from the 4- to 8-cell stage to the early 16-cell stage (19h) or from the early to the late 16-cell stage (6 h) showed significant rescue to the blastocyst stage. Once spontaneous decompaction of cells from DDK/C3H zygotes had begun (the late 16-cell stage onwards) methylamine treatment was no longer able to bring about rescue. We conclude that zygotes developed from eggs of the DDK strain fertilized by foreign spermatozoa are characterized physiologically by defective gap junctional communication. Improving gap junctional communication is sufficient to allow many zygotes to maintain the compacted state, suggesting a link between compaction and communication through gap junctions.

Functional gap junctions are not required for muscle gene activation by induction in Xenopus embryos

Muscle gene expression is known to be induced in animal pole cells of a Xenopus blastula after 2-3 h of close contact with vegetal pole cells. We tested whether this induction requires functional gap junctions between vegetal and animal portions of an animal-vegetal conjugate. Muscle gene transcription was assayed with a muscle-specific actin gene probe and the presence or absence of communication through gap junctions was determined electrophysiologically. Antibodies to gap junction protein were shown to block gap junction communication for the whole of the induction time, but did not prevent successful induction of muscle gene activation. The outcome was the same whether communication between inducing vegetal cells and responding animal cells was blocked by introducing antibodies into vegetal cells alone or into animal cells alone. We conclude that gap junctions are not required for this example of embryonic induction.

Drug use in the neonate: interrelationships of pharmacokinetics, toxicity, and biochemical maturity

With advances in technology, increasing numbers of premature and very ill neonates are surviving and being referred for treatment to neonatal intensive-care units. A major feature of the treatment they receive is therapy with drugs. However, because of relatively limited information available in the area of neonatal pharmacokinetics, the few drugs that currently can be monitored directly, and the lack of an effective mechanism for measuring the biochemical and functional maturity of the neonate, especially as it relates to drug clearance, therapy of neonates with drugs is certainly more hazardous and possibly less effective than in adult patients. Toxic reactions of neonates to drug therapy can usually be related to the unique pharmacokinetic processes seen in this group, particularly to the maturity of clearance mechanisms. This is the basis for a link between maturity and drug efficacy or toxicity. In this usage, maturity refers to the functional capacity of organs and biochemical pathways. Of particular concern in this regard is kidney function and the activity of drug-metabolizing enzyme systems. Because direct assessment of these functions in the neonate is difficult, other types of maturity markers that can be easily measured and which relate to drug clearance need to be identified. Such markers could serve as a guide to the physician who is planning drug therapy for a neonatal patient. Several studies looking for a gestational age marker have provided some indication that biochemical maturity markers do exist and simply await discovery, thus affording an integration of pharmacokinetics and pathophysiology to achieve a more rational and effective therapeutic approach.

Drug use in the neonate: interrelationships of pharmacokinetics, toxicity, and biochemical maturity

With advances in technology, increasing numbers of premature and very ill neonates are surviving and being referred for treatment to neonatal intensive-care units. A major feature of the treatment they receive is therapy with drugs. However, because of relatively limited information available in the area of neonatal pharmacokinetics, the few drugs that currently can be monitored directly, and the lack of an effective mechanism for measuring the biochemical and functional maturity of the neonate, especially as it relates to drug clearance, therapy of neonates with drugs is certainly more hazardous and possibly less effective than in adult patients. Toxic reactions of neonates to drug therapy can usually be related to the unique pharmacokinetic processes seen in this group, particularly to the maturity of clearance mechanisms. This is the basis for a link between maturity and drug efficacy or toxicity. In this usage, maturity refers to the functional capacity of organs and biochemical pathways. Of particular concern in this regard is kidney function and the activity of drug-metabolizing enzyme systems. Because direct assessment of these functions in the neonate is difficult, other types of maturity markers that can be easily measured and which relate to drug clearance need to be identified. Such markers could serve as a guide to the physician who is planning drug therapy for a neonatal patient. Several studies looking for a gestational age marker have provided some indication that biochemical maturity markers do exist and simply await discovery, thus affording an integration of pharmacokinetics and pathophysiology to achieve a more rational and effective therapeutic approach.

Toxic hepatic failure in newborn foals

Eight foals, 2 to 5 days of age, with similar clinical signs and laboratory and pathologic findings, died from hepatic failure. The predominant clinical signs were depression and icterus. Abnormally high values were found for plasma ammonia content, aromatic-to-branch-chain amino acid ratio, total serum bilirubin content, gamma glutamyl transferase activity, alkaline phosphatase activity, and PCV; partial thromboplastin time and prothrombin time were prolonged. Some foals had high sorbitol dehydrogenase activity. These laboratory findings were suggestive of subacute hepatic disease and failure. Predominant pathologic findings were limited to the liver and brain. The livers were less than half the expected size for 2- to 5-day-old foals, had prominent bile ductule proliferation, hepatic cell necrosis, and mild periportal fibrosis. These findings suggested both prenatal and postnatal diseases caused by exposure to a hepatoxin. The predominant lesion in the brain was the presence of Alzheimer type II astrocytes, which are characteristic of hepatoencephalopathy. Although the periportal fibrosis was suggestive of in utero exposure to a toxin, epidemiologic information suggested that the hepatic failure more likely resulted from oral inoculation of a microorganism culture product at birth. The same disease was reproduced in 2 newborn foals by feeding this product.

Equine anhidrosis: a review of pathophysiologic mechanisms

Anhidrosis is loss of the ability to sweat. The problem is seen in horses kept in a hot humid climate, and it may cause severe impairment of thermoregulation in the equine athlete. British Thoroughbreds imported to her tropical colonies are the earliest recorded cases, and since then the syndrome has come to be described as one of Thoroughbreds, usually performance athletes, undergoing acclimatization to heat and humidity. A recent epidemiologic study of cases in Florida has shown, however, that many different breeds, and long time inhabitants of a hot climate, may be affected. Equine sweat glands are of the apocrine type, and sweating is stimulated by direct local release of epinephrine from adrenergic nerve endings and by circulating epinephrine. Lack of sweating could be due to a number of possible flaws in a sequence from central nervous stimulation through sweat stimulation and secretion to delivery of sweat to the skin surface. The most likely possibilities are inadequate sweat gland response due to habituation of receptors to a high circulating level of epinephrine and occlusion of the sweat ducts by keratin plugs. Hormonal or metabolic imbalance may play a role both in the onset and secondary signs associated with anhidrosis.

Treatment of lactic acidosis

Severe lactic acidosis is often associated with poor prognosis. Recognition and correction of the underlying process is the major step in the treatment of this serious condition. Intravenous administration of sodium bicarbonate has been the mainstay in the treatment of lactic acidosis. Aggressive use of this therapeutic modality, however, can lead to serious complications and should therefore be considered with caution. Peritoneal dialysis and hemodialysis provide large amounts of alkali without causing the hypernatremia or hypervolemia commonly associated with bicarbonate infusion. Peritoneal dialysis with bicarbonate-based dialysate, in particular, appears to be an ideal means of delivering physiologic buffer. Administration of methylene blue was initially thought to increase lactate metabolism by altering the cellular oxidative state. Its subsequent clinical use, however, showed little efficacy. Sodium nitroprusside has been advocated for the treatment of some forms of lactic acidosis as a method of alleviating regional hypoperfusion. Insulin therapy has been found to be quite useful in the treatment of phenformin-associated lactic acidosis and is recommended in this setting. Since dichloroacetate activates pyruvate dehydrogenase and enhances lactate metabolism, it may be a useful adjunct in the treatment of lactic acidosis.

Effect of isoosmolar volume reduction during hemofiltration on plasma antidiuretic hormone in patients with chronic renal failure

The effect of isoosmolar volume reduction on plasma ADH level was studied in 8 patients with chronic renal failure utilizing hemofiltration technique. Plasma ADH fell significantly (P less than 0.001) after one hour of hemofiltration despite volume reduction which was expected to elevate the ADH level. After two hours of hemofiltration, ADH remained low in 5 patients and increased in 3. Post-hemofiltration mean blood pressure was generally lower in patients whose ADH rose than those whose ADH remained low. The two groups were otherwise comparable with respect to total fluid loss, hemofiltration rate, and fluid removed expressed as percent body weight. It can thus be suggested that in these patients a rise in plasma ADH in response to fluid reduction may require a fall in the arterial blood pressure below a critical level. While the rise in plasma ADH observed with continued fluid removal in some patients can be readily explained, we have no clear explanation for the paradoxical initial fall of ADH in all patients and subsequent maintenance of low levels observed in the majority of patients. This unusual ADH response to isoosmolar volume reduction may represent some unidentified mechanism of ADH regulation in patients with end-stage renal disease.

Hemodialysis studies of antidiuretic hormone

Hemodialyzability of antidiuretic hormone (ADH) was studied in 14 patients undergoing hemodialysis procedure. In addition hemofiltration (dry dialysis) was performed in 8 patients and hemofiltrate samples were collected for ADH assay. The mean values for plasma ADH level in ingoing and outgoing blood were nearly identical. Moreover, no ADH was detectable in the hemofiltrate samples. These findings suggest lack of significant ADH removal by dialysis or hemofiltration.

Comparison of results by three kit methods for assay of serum gastrin

We evaluated and compared Nuclear International, Schwarz/Mann, and Squibb kit methods for measurement of serum gastrin with respect to intra-run precision, analytical recovery of added gastrin, and values obtained for healthy fasting adults and for selected patients. As a result of this study, the Schwarz/Mann kit was chosen for use in our laboratory.

Comparison of results by three kit methods for assay of serum gastrin

We evaluated and compared Nuclear International, Schwarz/Mann, and Squibb kit methods for measurement of serum gastrin with respect to intra-run precision, analytical recovery of added gastrin, and values obtained for healthy fasting adults and for selected patients. As a result of this study, the Schwarz/Mann kit was chosen for use in our laboratory.

Supplementary visual stimuli and rotary pursuit performance

The effect of supplementary visual stimuli on rotary pursuit (RP) performance was evaluated in two experiments. In Exp. I a modified RP display presented target rotation within a visual guiding ring ( VG) to one group of 15 Ss, and a standard unguided RP display ( UG) to another ( n = 45 Ss). Subgroups of 15 Ss each were transferred from UG to VG after 20 trials (6.67 min. of practice) and after 33 trials (11 min. of practice). VG led to poorer performance after 33 trials at 60 rpm. Transfer from UG to VG led to loss in proficiency, early transfer producing a three times greater proficiency loss. Exp. II was conducted with 120 Ss to detemine whether the VG display possessed a distracting effect on a photoelectric RP task performed by 20 Ss each at 60, 70, and 80 rpm and compared with performance by a like number of Ss on task UG. The results confirm that VG produced poorer performance at 60 rpm after 10 min. of practice (30 20-sec. trials) although early VG performance was superior. VG was superior to UG performance at 70 and 80 rpm over all trials. It was concluded that visual stimuli which supplement the optical events of target motion can aid performance initially at 60 rpm and for a longer period at more rapid rates of rotation but probably retard the development of learning this skill.