The hypercalcemic effect of parathyroid hormone and skeletal cyclic AMP. The effects of parathyroid hormone (PTH) on bone mineral mobilization are thought to involve the second messenger cyclic AMP. Intravenous administration of 10 U PTH induced rapid and marked accumulation of cyclic AMP in calvaria and plasma of thyroparathyroidectomized rats. The changes in cyclic AMP concentrations were not sustained, but returned to near-baseline values before the rise in plasma calcium concentration was manifest. Changes in the plasma levels of calcium and cyclic AMP in response to PTH infusion were demonstrated in thyroparathyroidectomized rats who were nephrectomized as well. In a series of experiments to clarify the association of cyclic AMP accumulation and calcium mobilization, it was found that small doses of PTH induced significant elevation of plasma calcium without stimulating an accumulation of cyclic AMP in calvaria, or plasma. Furthermore, in intact rats plasma calcium levels were elevated by endogenous PTH, provoked by EGTA induced hypocalcemia, without any demonstrable change of cyclic AMP metabolism in the skeletal tissue. At a higher dose of PTH, the magnitude of the integrated change of cyclic AMP metabolism in the skeletal tissue was well correlated to the amount of calcium mobilized. These observations indicate a coupling between enhanced production of cyclic AMP and calcium mobilization in the action of PTH on bone. They also suggest that either a minute change in cyclic AMP accumulation, which can not be detected due to a high basal level of this nucleotide in the tissue, or a change in metabolism of cyclic AMP in some particular cell compartment is an early event in PTH-induced calcium mobilization.


Changes of endocrine properties of a transplantable, multihormonal, pituitary tumor (MtT-F4) after hypophysectomy of host rats. The transplantable rat pituitary tumor MtT-F4 failed to grow in rats hypophysectomized at the time of transplantation, but did grow in thyroxine-treated hypophysectomized rats. In the latter rats, the tumor did not stimulate the adrenals to the same extent as in control rats. When the tumor did not stimulate the adrenals to the same extent as in control rats. When the tumor cells were isolated and incubated in vitro, those from hypophysectomized thyroxine-treated rats released much less ACTH into the incubation medium than the tumor cells from control rats. They also released significantly less growth hormone than tumor cells from intact, intact thyroxine-treated, and thyroidectomized thyroxine-treated rats. Prolactin release by the isolated tumor cells in vitro was the same in all groups studied. The results suggest that the hypophysectomy and thyroxine treatment of the host rat might selectively influence the production of hormones by the MtT-F4 transplantable rat pituitary tumor.


Effect of lithium on catecholamine-induced antidiuresis and cyclic AMP in dog kidneys. Patients treated with lithium salt have an inability to concentrate urine, possible due to the inhibition of the antidiuretic effect of vasopressin. Since beta adrenergic stimulation also induces antidiuresis, a possible effect of lithium on the catecholamine-induced antidiuresis was investigated in dog kidneys. The urinary concentrating ability induced by the iv injection of isoproterenol 0.1 mug/kg was markedly inhibited in the lithium-treated animals (plasma lithium 1.13 plus or minus 0.10 mM). The increase of cyclic AMP concentration by 1 muM isoproterenol was also significantly less in the renal medullary slices obtained from the lithium-treated animals than in those obtained from the control animals. These findings suggest that the inability to concentrate urine in the patients treated with lithium salt is probably due to the inhibition of the antidiuretic effect of catecholamine as well as that of vasopressin; and the inhibitory mechanism of lithium on the catecholamine-induced antidiuresis is possibly through the inhibition of the catecholamine-dependent cycle AMP system in renal medulla.


3H-estradiol distribution in female, androgenized female, and male rats at 100 and 200 days of age. Tissue distribution of radioactivity was studied 48 h after gonadectomy and 1 h after iv injection of 3H-estradiol (1 mug/kg body wt) in 100- and 200-day-old normal female rats, female rats androgenized with 30, 100 or 1250 mug testosterone propionate (TP) at 5 days of age, and male rats. Receptor-mediated uptake of estradiol, as shown by diethylstilbestrol (DES) competition, was highest in preoptic area-anterior hypothalamus (POA-AH) and median eminence-basal hypothalamus (ME-BH), but also occurred in dorsal hypothalamus, pre-hypothalamic area, amygdala and septum in all groups. At 100 days of age there were no differences in brain radioactivity levels between females and androgenized females or males. At 200 days of age radioactivity levels in POA-AH and ME-BH tended to be lower in androgenized female and male rats than in normal females. Also, radioactivity levels in the amygdala were lower in the 1250 mug TP-treated females than in normal females. When expressed per unit fresh weight, uptake in the anterior pituitary tended to be lower in androgenized rats at 100 days of age and was higher in males at 200 days of age than in normal females, but did not differ among any of the groups when expressed as uptake per organ. Thus, the well-known differences among these groups in neural regulation of gonadotropin secretion and sex behavior were not correlated with consistent differences in specific estradiol binding by hypothalamic or other brain areas or pituitary. The uterus took up less estradiol in androgenized females than in control females at both ages. Estradiol receptor activity was demonstrated in kidney of all animals and in seminal vesicles. At both ages radioactivity levels in the toluene and ethanol extracts of lever and kidney were strikingly higher in males than in the female groups. Reviewing the data, it appears that despite some evidence of differences between groups, males, females and androgenized females all have relatively similar limited-capacity, estradiol-uptake systems in brain and pituitary, as measured under the conditions of the present study.


Inhibition by iodide of the activation of the thyroid cyclic 3',5'-AMP system. The action of iodide on the cyclic AMP system of dog thyroid slices has been studied. Iodide inhibits the enhancement of cyclic AMP accumulation in the presence of TSH. Such an effect is also observed in horse, beef and sheep thyroid slices, but not in dog kidney slices stimulated by parathyroid hormone or in rat parotid slices stimulated by isoproterenol. The effect in dog thyroid slices is suppressed by 1mM NaClO4, 1mM methimazole and 1mM propylthiouracil. Similar data have been obtained for prostaglandin E1 stimulation. Effects of thyrotropin mediated by cyclic AMP, i.e., activation of iodothyronine secretion, 1-14C-glucose oxidation, and lactate formation, were also inhibited by iodide but not by iodide and methimazole. Similar activations when caused by dbcAMP were not inhibited by iodide. The data suggest a model in which an intracellular agent resulting from the oxidation of iodide acts on the thyroid cyclic AMP system.


A short method for the isolation of somatotrophs from the rat pituitary gland. Application of a density gradient centrifugation procedure for the isolation of somatotrophs from dispersed rat anterior pituitary cells is described. Two sequential discontinuous gradients of bovine serum albumin are used to enrich the somatotroph population from a frequency of 38% in the initial cell suspension to a final purity of 85%. The isolated somatotrophs retain both histochemical and ultrastructural integrity throughout the isolation procedure. The isolated somatotrophs also release immunoassayable growth hormone when incubated with 6 mM dibutyryl 3',5'-cyclic AMP. The method offers the advantages of being both simple and short.


Stimulation of the uptake of alpha-aminoisobutyric acid in rat thymocytes by L-triiodothyronine: a comparison with insulin and dibutyryl cyclic AMP. L-Triiodothyronine in vitro increased the uptake of the non-metabolizable amino acid, alpha-aminoisobutyrate, into isolated rat thymocytes. This effect was evident at extracellular free hormone concentrations of 10-7 to 5 times 10-8M and was due to a marked inhibition of amino acid efflux. In contrast, insulin and dibutyryl cyclic AMP, which also increased uptake in these cells, acted to stimulate amino acid influx. When L-triiodothyronine was added to maximally effective concentrations of either insulin or dibutyryl cyclic AMP, the resultant effect was the sum of the effect of each hormone added individually. These studies extended previous observations which indicate that thyroid hormones stimulate the cellular uptake of amino acids, and they provide a convenient system for the study of thyroid hormone action in vitro.


The conformation of adenosine diphosphoribose and 8-bromoadenosine diphosphoribose when bound to liver alcohol dehydrogenase. 8-Bromo-adenosine diphosphoribose (br8 ADP-Rib) and nicotinamide 8-bromoadenine dinucleotide (Nbr8AD+) which are analogues of the coenzyme NAD+, were prepared and their liver alcohol dehydrogenase complexes studied by crystallographic methods. Nbr8AD+ is active in alcohol dehydrogenase complexes studied by crystallographic methods. Nbr8AD+ is active in hydrogen transport and br8ADP-Rib is a coenzyme competitive inhibitor for the enzymes liver alcohol dehydrogenase and yeast alcohol dehydrogenase. X-ray data were obtained for the complex between liver alcohol dehydrogenase and br8ADP-Rib to 0.45 nm resolution and for the liver alcohol dehydrogenase-adenosine diphosphoribose complex to 0.29-nm resolution. The conformations of these analogues were determined from the X-ray data. It was found that ADP-Rib had a conformation very similar to the corresponding part of NAD+, when NAD+ is bound to lactate and malate dehydrogenase. br8ADP-Rib had the same anti conformation of the adenine ring with respect to the ribose as ADP-Rib and NAD+, in contrast to the syn conformation found in 8-bromo-adenosine. The overcrowding at the 8-position is relieved in br8ADP-Rib by having the ribose in the 2' endo condormation instead of the usual 3' endo as in ADP-Rib and NAD+.


Effects of fasting on the control of fatty-acid synthesis in hepatoma 7777 and host liver. Role of long-chain fatty acyl-CoA,, the mitochondrial citrate transporter and pyruvate dehydrogenase activity. The effects of fasting on the rate of fatty acid synthesis, the properties of the mitochondrial citrate transporter and on pyruvate dehydrogenase activity were investigated in "poorly-differentiated" tmorris hepatoma 7777 and in host liver preparations. The properties of the citrate transporter from hepatoma mitochondria were similar to those of host liver mitochondria, with the exception that the Km for the liver mitochondrial citrate transporter was 248 plus or minus 20 mu M while that in hepatoma mitochondria was less than 75 mu M. The acid-insoluble CoA content was 180 plus or minus 20 pmol/mg protein in the hepatoma and remained essentially unchanged in the fasted state, while the acid-insoluble CoA levels in livers from fed rats was 720 plus or minus 80 pmol/mg protein and were increased to 1050 plus or minus 50 pmol/mg protein during fasting. After a 36-h fast, the rate of lipogenesis and the percentage of pyruvate dehydrogenase present in the active form were each decreased by approximately 80% in host liver preparations. In contrast, the rate of lipogenesis by hepatoma slices did not decrease during fasting, and essentially all pyruvate dehydrogenase present was in the active form of hepatomas obtained from either fed or fasted animals. Implications concerning the identification of possible regulatory sites in the control of lipogenesis were discussed in relation to the above observations.


Thalamo-cortical projections for recruiting responses and spindling-like responses in the parietal cortex. 1. The thalamic neurones sending their axons to the parietal association cortex (middle suprasylvian gyrus) and receiving monosynaptic excitation from the cerebellar (interpositus or lateral) nucleus were recorded with microelectrodes extracellularly and intracellularly around the anterior ventral (VA) nucleus of the thalamus in cats. Such thalamic neurones are known to carry exclusively the impulses responsible for superficial thalamo-cortical (T-C) responses in the parietal cortex, being called superficial T-C neurones (see Sasaki et al., 1972a, b). 2. Repetitive (6--9/sec) stimulation of the centrum medianum-parafascicular complex (CM) or the intralaminar nuclei (IL) of the thalamus elicited grouped spike discharges of the neurone in synchronization with the recruiting responses in the parietal cortex. The grouped discharges usually preceded the respective cortical responses by several milliseconds. Numbers of the spikes in the grouped discharges increased and decreased as the recruiting responses waxed and waned on the repetitive stimulation. 3. The superficial T-C neurones also showed similar grouped discharges in synchronization with spindling-like, surface-negative cortical responses which occurred spontaneously or were evoked by single thalamic stimulation. 4. It was concluded that the superficial T-C neurons can convey impulses for recruiting responses and spindling-like responses from the thalamus directly to the cerebral cortex. They are supposed to constitute the final T-C pathway of the neuronal circuits of the recruiting system, i.e., non-specific T-C projection system.


Hormonal regulation of hepatic P-enolpyruvate carboxykinase (GTP) during development. Hepatic gluconeogenesis in the rat does not begin until birth. The enzyme P-enolpyruvate carboxykinase appears initially at birth and is the final enzyme in the gluconeogenic sequence to develop. The appearance of this enzyme in the cytosol of rat liver is caused by the stimulation of enzyme synthesis, probably due directly to an increase in the hepatic concentration of cAMP. Enzyme degradation does not begin until 36 hours after birth. Studies with fetal rats in utero have shown that dibutyryl cAMP or glucagon will stimulate P-enolpyruvate carboxykinase synthesis and that this effect can be blocked by insulin. Insulin is known to depress the synthesis of P-enolpyruvate carboxykinase in adult rat liver and in Reuber H-35 liver cells in culture. The glucocorticoids are without effect on the synthesis of the enzyme in fetal rat liver. Work by Girard et al. (J. Clin. Invest. 52: 3190, 1973) has established that the molar ratio of insulin to glucagon drops from 10 immediately after birth, to 1 after one hour. This is due to both a rise in glucagon and a fall in insulin concentrations at birth. These studies, together with our work on the synthesis of P-enolpyruvate carboxykinase, indicate that the sharp drop in the concentration of insulin may relieve the normal inhibition of enzyme synthesis. This would allow the initial stimulation of enzyme synthesis by the glucagon-mediated rise in the concentration of CAMP.


Impaired hormonal regulation of enzyme activity during aging. A general feature of all aging populations is the progressively impaired ability to adapt to changes in the surrounding environment. Biochemical expressions of adaptive response include modifications in the rates of enzyme synthesis and degradation, as well as alterations in physiological activity. Therefore, the effects of aging on enzyme adaptation were surveyed in an attempt to explore fundamental biochemical mechanisms in the deterioration of responsiveness. The ability to stimulate adaptive increases in the activity of a large number of enzymes is impared during aging in a variety of tissues from several different species. The impaired capability for liver enzyme adaptation in a rigorously controlled colony of aging male Sprague-Dawley rats probably reflects alterations in hormonal control mechanisms. The present article reviews and evaluates our interest in understanding the effects of aging on regulation of liver enzyme activity by the hormones, insulin and corticosterone. Specific areas currently under investigation include: (1) the regulation of their concentrations in blood; (2) the integrity of their receptor systems in liver; and (3) effectiveness of the endogenous hormone pools fromthe viewpoints fothe availability of physiological antagonists and the potential for alterations in molecular structure.


Age-related changes in glucocorticoid binding by rat splenic leukocytes: possible cause of altered adaptive responsiveness. Splenic leukocytes of senescent rats (24-26 mo) exhibit a 60% reduction in cortisol-induced inhibition of 3-H-uridine uptake when compared to mature adult animals (12-14 mo). The degree of inhibition is directly proportional to cortisol dosage up to 2 X 10-6 M. Specific binding of physiological (nanomolar) concentrations of 3-H-cortisol by leukocytic cytosol macromolecules is reduced by over 40% in the older animals. Moreover, Scatchard analyses reveal 60% fewer specific glucocorticoid binding sites in the cytosols of cells from the senescent rats. Such analyses were performed in vitro at 0 C to eliminate metabolism of steroids. In addition, 3-H-dexamethasone was used instead of 3-H-cortisol to eliminate binding to plasma (or serum) transcortin. Inhibition of 3-H-uridine uptake requires specific glucocorticoid binding. The degree of inhibition at varying glucocorticoid dosages is proportional to the amount of specific binding to cytoplasmic macromolecules. Thus, age-related reduction in specific glucocorticoid binding sites may be at least partially responsible for altered responsiveness of splenic leukocytes to these hormones.


Impotence in patients with chronic renal failure on dialysis: its frequency and etiology. Fourteen patients with chronic renal failure and on a hemodialysis program underwent neurologic, psychiatric, and endocrine studies to determine the frequency and etiology of impotence in uremics. The data suggest that impotence is more frequent in the chronic dialysis group than in the general population. All seven of the impotent men were found to have prolonged nerve conduct on velocity and absent bulbocavernosus reflexes. Several of the impotent men also had clinical depression and low plasma testosterone levels. Neuropathy may be a significant factor in the pathogenesis of impotence in the uremic, but the importance of both psychiatric and endocrine influences must be strongly considered.


Cell membrane changes in chronically diabetic rats. We have examined the effect of chronic diabetes mellitus upon cell membrane composition and turnover in streptozotocin-treated rats and control animals maintained for four to eight weeks. Liver plasma membranes, prepared from diabetic animals, showed enhanced activities of alkaline phosphatase and glucose-6-phosphatase and depressed 5'-nucleotidase when compared with controls. Studies of the nonprotein constituents of liver plasma membranes and red cell "ghosts" showed similar changes in both tissues: sialic acid and cholesterol content were reduced in the membranes of diabetic animals, while phospholipids (total and individual classes) and neutral sugars were unchanged. To look for changes in relative turnover rates of individual membrane proteins, we combined a double-label in-vivo technic using [3H] and [14C] leucine with polyacrylamide gel separation of membrane proteins. No significant differences were observed between control and diabetic animals. In chronically diabetic animals, cell membranes may show significant changes in overall composition with no significant changes in the rate of protein turnover.


Intravenous pentagastrin as a partial agonist of gastric secretion in man: evidence in favor of the existence of hormonal inhibitory sites. The gastric secretory response to prompt intravenous injection of pentagastrin was investigated in 3 normal subjects and 3 patients with duodenal ulcer. The highest responses to pentagastrin and histamine were correlated. Intravenous pentagastrin in a dose of 0,5 mug per kg could thus achieve the same extent of discrimination between individuals with a 10-fold economy in dosage over subcutaneous pentagastrin. Sensitivity to pentagastrin, expressed in the D50, was higher in patients with duodenal ulcer. Unexpectedly, the highest response to intravenous pentagastrin was only 40% of the peak response to subcutaneous histamine. Accordingly, intravenous pentagastrin acted as a partial agonist with an efficacy of about 0.4. The effect of prompt injection of pentagastrin contrasted with the effect of slow intravenous infusion of pentagastrin, as well as with the effects of gastrin-17 given by either prompt injection or slow infusion. A model is proposed to account for these and related findings in other species. The secretory receptor for gastrin and its analogues is viewed as consisting of two sites: a high affinity stimulatory site and a low affinity inhibitory site. Partial agonism after prompt intravenous injection would result from blood and tissue transients which are successively too high (partially inhibitory) and low (stimulatory). The disparate effects of analogues and the differences between species would be determined by the relative affinities of the two sites. The overflow of stimulant into inhibitory sites would account for the reversal of response at high doses observed in numerous studies.


In vitro interactions of gastrointestinal hormones on cyclic adenosine 3':5'-monophosphate levels and amylase output in the rat pancreas. Four-fold increases in cyclic AMP levels were observed 5 to 10 min after rat pancreatic fragments were incubated with 10-7 M secretin or 10-6 M vasoactive intestinal polypeptide (VIP), in addition to 10 mM theophylline. From dose-response curves it appears that, on a molar basis, the potency of secretin was 20 times higher than that of VIP. It is concluded that cyclic AMP is probably the intracellular messenger of both secretin and VIP in centroacinar cells. Pancreozymin, caerulein, and the C-terminal octapeptide of pancreozymin inhibited the production of cyclic AMP observed with secretin of VIP, suggesting that the first three peptides were acting at a binding site different from the agonists, but coupled with the same adenylate cyclase. In acinar cells, secretin was able to exert slight ecbolic effects, and was also able to potentiate the effect of maximal concentrations of pancreozymin, caerulein, or the C-terminal octapeptide of pancreozymin. There was no simple correlation between amylase output and cyclic AMP levels, and copious amylase secretion was elicited even at control levels of cyclic AMP. Glucagon was neither an agonist nor an antagonist of any of the other polypeptides tested.


Relationship of serum alpha-fetoprotein to the severity and duration of illness in patients with viral hepatitis. Using a radioimmunoassay which detect concentrations of alpha-fetoprotein as low as 5 ng per ml, 38% of 176 patients with viral hepatitis compared with health volunteers and patients with chronic diseases not affecting the liver. When separated into two groups based on histological classification of liver biopsy specimens, differences in the degree and frequency of increased serum alpha-fetoprotein were related to the severity of the hepatic lesion. Of 75 patients with the lesion of viral subacute hepatic necrosis, in which zones of necrosis bridge adjacent portal triads or central veins, 52% had increased values, and 12% had levels ranging from 500 to 3300 ng per ml. In contrast, only 28% of the 101 patients without bridging necrosis had increased values, and none had levels that exceeded 500 ng per ml. In the patients with subacute hepatic necrosis, comparison of alpha-fetoprotein concentrations with the duration of illness indicated that the protein rose to peak levels in serum as the SGOT was declining. This was confirmed by serial observations in 10 patients. Thus, the increase of alpha-fetoprotein in the sera of patients with severe hepatitis occurs as liver necrosis is subsiding. Due to other known features of alpha-fetoprotein, it is intriguing to speculate that the increase in serum levels of this protein in viral hepatitis reflects hepatic regeneration after parenchymal damage.


The hidden faces of alcoholism.

The hidden faces of alcoholism. In view of the fact that 70 percent of Americans drink regularly, it is important to keep in mind that alcohol is a potent pharmacologic agent that can cause a variety of emotional and physical signs and symptoms. Physician awareness is the name of the game. Better health for patients is the reward.


Induction of nutritional mutants of Micrococcus glutamicus and their amino acid accumulation. Micrococcus glutamicus ATCC 13032, a glutamic acid-producing organism, was treated with 0.2M ethylmethane sulfonate, the auxotrophs isolated showing varied patterns of extracellular amino acids. Eighty auxotrophic strains were obtained, out of which 31 excreted 1.0-4.0 mg threonine per ml and all the auxotrophs required biotin for growth and production of the amino acid. Eleven auxotrophs produced 1.5 to 3.0 mg alanine per ml and these auxotrophs required amino acids for their growth. Other auxotrophs lost their excretion capacity in subsequent fermentation trials. Further mutation of the biotin-requiring auxotroph Micrococcus glutamicus EM with gamma rays resulted in the isolation of 89 auxotrophic strains, out of which 28 excreted threonine (up to 5.0 mg per ml) higher than the parent auxotroph. Exposure to X-rays yielded 97 auxotrophs, out of these 35 producing 1.0-3.0 mg methionine per ml and requiring biotin for growth and production of the amino acid. Other auxotrophs produced alanine (0.5 to 2.0 mg per ml) and threonine (2.0 to 3.3 mg per ml). Irradiation with gamma rays favoured the development of threonine producing auxotrophs while X-rays favoured methionine-producing auxotrophs.


Effect of cyclic nucleotides on DNA synthesis in mouse lymphoid cells. The effect of eight cyclic purine and cyclic pyrimidine nucleotides on DNA synthesis on mouse lymphoid cells was investigated. Two out of eight compounds tested, namely 2', 3'-cyclic guanosine monophosphate (2', 3'-cGMP) as well as 3', 5'-cyclic guanosine monophosphate (3', 5'-cGMP), stimulate thymidine incorporation in all types of lymphocytes tested. The stimulatory activity of the cyclic guanosine nucleotides as well as the effects of lectins could be antagonized by 3', 5'-cyclic adenosine monophosphate (3', 5'-cAMP). 2', 3'-cGMP seems to stimulate preferentially mature T-cells while 3', 5'-cGMP preferentially acts on B-cells.


The antagonistic action of cyclic GMP and cyclic AMP on proliferation of B and T lymphocytes. The effect of c-AMP, c-GMP and both substances together on (3H)-thymidine incorporation into nuclear DNA was investigated using spleen cells of normal and athymic nude mice. c-GMP induces DNA synthesis in both normal and nude spleen cell populations. c-AMP inhibited the stimulatory activity of c-GMP as well as the phytohaemagglutinin (PHA) and lipopolysaccharide (LPS) response of spleen cells. The inhibitory activity of c-AMP on the PHA and LPS responses can be reversed by c-GMP. The possible role of cyclic nucleotides in the regulation of cell proliferation and of the immune response is discussed.


Stimulation of human lymphocytes by Herpes simplex virus antigens. Lymphocytes from individuals with laboratory evidence of prior infection with herpes simplex virus (HSV) type 1 or type 2 demonstrated transformation (av antigens. Higher stimulation indexes were obtained when lymphocytes were incubated with the homologous as compared with the heterologous antigen. Higher mean lymphocyte stimulation indexes were also demonstrated in seropositive as compared with seronegative individuals. Lymphocytes from children with HSV-1 stomatitis usually became responsive to HSV-1 antigen within 2 to 6 weeks after the onset of illness. Lymphocytes from infants with neonatal HSV-2 infection were stimulated by HSV-2 antigen.


Characterization of an in vitro persistent-state measles virus infection: species characterization and interference in the BGM/MV cell line. Serological methods of mixed agglutination and indirect immunofluorescence showed the BGM/MV cell line to possess monkey antigens. As a means of further characterizing the species constitution of the BGM/MV cell line, the species specificity of viral-induced interferon from these cells, as well as the response of these cells to exogenous interferons, was determined. Low titers of spontaneously elaborated interferon capable of protecting monkey but not mouse cells were detected in BGM/MV culture fluids. Interferon induced by Newcastle disease virus infection of BGM/MV cells was capable of conferring an antiviral state on monkey and, to a lesser extent, on mouse cells. Exogenous interferons of both homologous (BGM/MV) and heterologous sources failed to confer an antiviral state on BGM/MV cells. BGM/MV cells were found to be partially refractive to superinfection with measles virus but freely replicated mumps and vesicular stomatitis virus.


Antibody response to Epstein-Barr virus in infectious mononucleosis. Altogether 171 serum specimens from 58 patients with heterophil antibody-positive infectious monomucleosis were studied for antibody response to Epstein-Barr virus (EBV). The sera were tested for fluorescent immunoglobulin G (IgG) and IgM gel-precipitating (GP) and complement-fixing (CF) antibodies to EBV. All 58 patients had IgG and IgM antibodies to EBV. Both IgG and IgM antibodies developed rapidly; the IgM antibodies disappeared within 8 to 10 weeks, whereas the IgG antibodies remained at an almost constant level. The development of IgG antibodies was so rapid that a fourfold or greater rise in titers was noted only in 22% of the patients. Both GP and CF antibodies to EBV (crude P3HR-1 Burkitt cell antigen) developed slowly; the mean titers kept rising for more than 12 weeks. The micro GP technique seemed to be more sensitive than the CF method, because 86% of the patients with infectious mononucleosis had GP antibodies compared with 72% having CF antibodies. In patients with infectious mononucleosis, a seroconversion or significant rise in GP antibodies was noted in 57%, whereas only 19% had a similar change in CF antibodies. The most promising of these antibody assays in the diagnosis of recent infections was the EBV-specific IgM antibody technique, which enables one to make the diagnosis on the basis of only one serum specimen. In cases where the acute-phase serum specimen is missing, the diagnosis can be made later by using the GP and CF techniques.


Virus susceptibility of mouse hemopoietic cells in vitro: inhibition of granulocyte-macrophage precursor cells by Newcastle disease virus. Normal mouse bone marrow cells were exposed to encephalomyocarditis virus (EMC), reovirus type 3 (REO3), influenza virus (FLU), and Newcastle disease virus (NDV) then assayed for granulocyte-macrophage precursor cells by the technique of colony formation in agar. Exposure to EMC, REO3, and FLU caused a slight but variable loss of colony-forming potential, whereas exposure to NDV caused a very marked loss. NDV acted directly on the cells, not indirectly through release of colony-inhibiting factors or destruction of colony-stimulating factor. Experiments with NDV inactivated by heat, ether, or ultraviolet irradiation indicated that colony inhibition was associated with fully infective virus, even though some of the inactivated preparations had retained full hemagglutinin, neuraminidase, or hemolytic activity.


Escherichia coli enterotoxin: stimulation of adenylate cyclase in broken-cell preparations. The enterotoxin from cell-free filtrates of the enteropathogenic Escherichia coli strain P-263 was found to stimulate adenylate cyclase activity in broken-cell preparations from myocardial tissue. Particulate and detergent-solubilized fractions from cat heart were incubated with enterotoxin and assayed for adenylate cyclase activity. Adenylate cyclase activity was stimulated by enterotoxin; the extent of stimulation was proportional to the concentration of enterotoxin. The data demonstrate that stimulation of enterotoxin-sensitive adenylate cyclase in this system provides a sensitive in vitro assay, either as an accurate measure of enterotoxin concentration or as an assay for antitoxic titers in sera. A parallel comparison showed that stimulation of fluid production in rabbit intestinal loops by enterotoxin was less sensitive.


Naturally occurring persistent feline oncornavirus infections in the absence of disease. Healthy feline leukemia virus (FeLV)-infected cats from leukemia cluster environments were followed for up to 23 months for development of disease and evidence of alteration in the hemogram. The incidence of disease development in FeLV-postive cats was more than fivefold higher than the incidence for FeLV-negative cats. Ten cases of leukemia developed in 69 infected cats, whereas one case of leukemia occurred in 59 uninfected cats. The incidence for development of diseases other than leukemia was 30.4 percent for FeLV-infected cats as opposed to 6.8 per cent for uninfected cats. This could be a result of the immunosuppressive effects of FeLV. Felv-infected cats had no evidence of subclinical anemia. Mean packed cell volumes and total leukocyte counts were about the same for infected and uninfected animals. The only variation seen in healthy FeLV-infected cats was a decreased mean lymphocyte count. The difference between mean lymphocyte count for FeLV-infected and uninfected animals was significant at the 0.999 level. These findings suggest that the incubation period for feline leukemia may be very prolonged under natural conditions and that an increased susceptibility to unrelated infectious diseases exists during this period. This increased susceptibility was apparently not associated with anemia or depressed total leukocyte counts.


Genital herpesvirus hominis infection in mice. I. Development of an experimental model. Pregnant female mice, after intravaginal inoculation with Herpesvirus hominis (HVH) type 2, developed vaginitis on days 5 to 7 after virus challenge, followed by hunching and hind limb paralysis on days 7 to 9  and death from encephalitis on days 9 to 11. After initial replication in the mucous membranes of the genital tract, virus spread to the spinal cord and ascended to involve the brain. Viremia or replication of H. hominis type 2 in the liver or spleen was not detected. Virus was cleared from vaginal secretions by days 8 to 10 after infection. Pregnant mice were more susceptible to the infection than nonpregnant mice. This experimental infection in female mice provides a model for genital herpesvirus infection and for herpesvirus infection and for herpesvirus encephalitis in which one can evaluate potentially promising antiviral chemotherapeutic agents.


Response of irradiated mice to live-virus (TC-83) immunization. Studies were conducted to determine the effects of sublethal, acute, total-body irradiation (600 R) on the immune response of mice to a replicating antigen. Irradiation was performed at varying times (0 to 21 days) prior to immunization with attenuated Venezuelan equine encephalomyelitis virus, TC-83. Development of protective immunity was studied by inoculating subgroups of irradiated mice with virulent Venezuelan equine encephalomyelitis virus on days 1 through 28 after immunization. Irradiation failed to affect the overt clinical response of mice inoculated with the attenuated strain, but antibody responses and the onset of protective immunity was delayed, particularly in mice irradiated 2 h to 3 days prior to vaccination. Immunity afforded by TC-83 developed more rapidly as the interval between irradiation and vaccination increased: when this interval was 14 or more days, the temporal course of immune response in irradiated mice was similar to that of nonirradiated vaccines. Persistence of TC-83 viremia was greatly prolonged in irradiated mice through the irradiation recovery period and probably provided the antigenic stimulus responsible for delayed development of effective immunity.


Defense mechanisms against infectious bovine rhinotracheitis virus: inhibition of virus infection by murine macrophages. An in vitro method is described to measure the inhibitory activity of murine peritoneal exudate cells against viral plaque formation by a bovine herpes-virus-infectious bovin'e rhinotracheitis virus. Microtiter plates containing 96 bovine kidney cell monolayers were infected with a range of virus concentration and peritoneal exudate cells were subsequently added. When a sufficient number of cells was added, viral plaques were not detectable and free infectious virus did not occur in the culture fluids. The inhibitory cell type adhered to glass and was presumably a macrohage. Although inhibitory of viral plaques was presumably a macrophage. Although inhibition of viral plaques was complete and free virus could not be detected, virus was not eliminated from the monolayers since on removal of cells, the degree of virus cytopathology and yield of virus after a further 48 h of incubation was the same as in 48-h infected control monolayers. The significance of peritoneal exudate-cells-induced virus suppression as a model to understand herpesvirus latency is briefly discussed.?Author


Analysis of unidirectional fluxes of sodium during diarrhea induced by Clostridium perfringens enterotoxin in the rat terminal ileum. Net intestinal transport of sodium in vivo, in control and enterotoxin (Clostridium perfringens)-treated rats, was resolved into two unidirectional fluxes, influx from and efflux into the lumen of the terminal ileum. In rats treated with the toxin, sodium influx remained similar to control values even during fluid and electrolyte loss to the lumen. Net loss of sodium was shown to be due to nearly a twofold increase in sodium efflux to the lumen in toxin-treated animals. There was only slight histopathological damage to the mucosa, especially noticeable at the tips of villi.


Adenovirus-transformed cells restrict Herpes simplex virus replication. A cell line that normally supports the replication of herpes simplex virus types 1 and 2 became resistant to these viruses after transformation by simian adenovirus 7. Kinetic studies of the mechanism of resistance demonstrated that both herpesviruses were able to attach to the transformed cells and express some early genomic functions, as demonstrated by the presence of low levels of viral thymidine kinase. However, isopycnic centrifugation studies of the abortive system failed to detect viral deoxyribonucleic acid synthesis, whereas indirect immunofluorescent studies of viral proteins revealed that less than 10 per cent of the cells contained these viral macromolecules at any given time. Collectively the data suggest that after transformation by simian adenovirus 7 these cells are altered so as to render them resistant or incapable of supporting the growth of herpes simplex virus types 1 and 2. The results further suggest that the block occurs after viral absorption and prior to viral deoxyribonucleic acid synthesis.


Enterotoxin formation by different toxigenic types of Clostridium perfringens. Sixty-nine strains of Clostridium perfringens of different toxigenic types were investigated for enterotoxin production. Enterotoxin was definitively detected only in strains of types A and C. This is the first report where enterotoxin production has been demonstrated in a toxigenic type other than type A. The exterotoxin-positive type C strains were isolated from cases of enteritis necroticans ("pig bel+) in New Guinea. The major enterotoxin from type C showed a reaction of complete identity with enterotoxin from type A in immunodiffusion using anti-enterotoxin serum prepared against the latter; it induced erythema when injected intradermally into depilated guinea pigs and caused fluid accumulation in the rabbit ileal loop.  The results indicate that the major enterotoxin from type C was serologically and biologically similar to enterotoxin from type A. In some C was serologically and biologically similar to enterotoxin from type A. In some type C strains, an enterotoxin was detected that showed a reaction of partial serological identity. Spore coat proteins were extracted from 14-strains by alkaline dithiothreitol, and the extracts were assayed for enterotoxin-like spore protein. Enterotoxin could be extracted from type A and type C spores, and all positive strains showed a reaction of complete identity in immunodiffusion with enterotoxin obtained from cell extracts of type A. Disc immunoelectrophoresis demonstrated that two distinct components that reacted serologically with anti-enterotoxin serum were present in both the cell extract and in extracted spore protein from one type C strain. These distinct components differed in molecular weight.


Effect of immunosuppression on the genetic resistance of A2G mice to neurovirulent influenza virus. A2G mice are genetically resistant to lethal infection with neurotropic and pneumotropic influenza viruses. A possible immunological explanation for this resistance was sought by assessing the effect of cyclophosphamide and X irradiation immunosuppression on the infection of A2G mice with lethal doses of neurovirulent virus. Immunosuppressed A2G mice survived lethal infection enen though rendered unable to produce specific antiviral antibody or to generate cell-mediated delayed-type hypersensitivity responses. Measurement of infectious virus replication and detailed observation of the infection by immunofluorescence microscopy show that immunosuppression does not potentiate or allow spread of the virus in A2G brains. Interferon levels were essentially the same in normal and immunosuppressed A2G brains but were 3 to 5 times lower than in the brains of susceptible mice dying of the infection. The results strongly suggest that the genetic resistance of A2G mice to the acute lethal effects of neurovirulent influenza virus infection does not depend on the induction of primary immune mechanisms as we currently understand them. Other possible explanations for this resistance are considered.


Effect of Mycoplasma pneumoniae on poliovirus replication. Results are presented which indicate that different species of mycoplasma may have varying effects on the replication of different viral types.


Immunological comparison of various human pregnancy-associated plasma proteins. Direct immunodiffusion comparison with specific antisera demonstrated that all of the four pregnancy-associated plasma proteins (PAPPs) described in our laboratory are distinct from the pregnancy zone protein (von Schoultz); alpha2-pregnoglobulin (Berne); pregnancy-associated alpha2-glycoprotein (SP3) (Bohn); new serum alpha2-macroglobulin (Stimson); PAG (Horne); pregnancy-associated alpha2-globulin (Kasukawa); Pal (McLaren), and Xh protein (Dunston). All the latter proved to be immunologically idnetical to each other, and apparently represent the same protein described under different names. It was confirmed that none of the PAPPs is immunochemically related to placental alkaline phosphatase. PAPP-A, PAPP-C, and the pregnancy zone protein, but not HPL (PAPP-D), showed a decreased anodic mobility when treated with neuraminidase; their reactivities with antibody were essentially unaffected by the ezyme, however. Certain detergents had no effect on the immunological reactivities of the PAPPs and the pregnancy zone protein in whole plasma, while butanol and desoxycholate partially, and urea, SDS and cetylpyridinium largely inactivated them.


Further studies on the inheritance of responsiveness to pertussis HSF in mice. Inheritance of responsiveness to histamine-sensitizing factor of pertussis bacilli (HSF) was investigated in (C3H/HeJ times C57BL/6J)F1 hybrids, backcross progeny of this hybrid to C57BJ/6J parent (C3H/HeJ times DBA/2J)F1 hybrids, and in backcross progeny of this hybrid to DBA/2J parent. It was found that transmission is not by virtue of a single autosomal dominant gene, as has been postulated. Rather, inheritance of responsiveness to HSF is far more complex, probably involving polygenic transmission.


The action of ionizing radiation on protein: radical formation in L-histidine crystals. Radicals produced at temperatures between 77 K and 300 K by X-irradiation of L-histidine.2HC1 crystals have been analysed by electron spin resonance spectroscopy. The results are compared with previous findings with L-histidine and L-histidine.HC1.H2O crystals. In these three crystals we have identified three main species, which, depending on the molecular environment, are stabilized at different temperatures and produced in different concentrations. These findings are discussed in connection with the observations made on irradiated aqueous solutions of amino acids. It is concluded that our results corroborate the mechanism for the action of ionizing radiation on dry protein proposed by Platzman and Franck (1958),


Sensitivity of glucose 6-phosphatase activity to glutaraldehyde. The effect of glutaraldehyde fixation on glucose 6-phosphatase activity in mouse liver was investigated. After transparenchymal perfusion with 2% glutaraldehyde for 1.5 minutes, the activity of the recovered enzyme was higher than those reported for acid phosphatase and aryl sulfatase activities after fixation under similar condition, and an abundant deposition of reaction product was observed in hepatocytes. Subsequent immersion in the same fixative solution for 30 minutes after 4 degrees C resulted in only a slight decrease in the activity. However, the activity was almost completely destroyed after 3 hours of immersion fixation at 4 degrees C following the perfusion. Therefore, the enzyme can be said to be aldehyde-sensitive when a long fixation time is used, but not aldehyde-sensitive during a short fixation time.


Isolation of a metabolite capable of differentially supporting the growth of nicotinamide adenine dinucleotide auxotrophs of Escherichia coli. A compound, isolated from the culture fluid of a nadC auxotroph of Escherichia coli grown in a minimal medium, supports the growth of both a nadA and a nadB mutant. This metabolite exhibits an ultraviolet light absorption spectrum and a mass spectrum, different from quinolinic acid. This compound may be the precursor of quinolinic acid, an intermediate in the biosynthesis of nicotinamide adenosine dinucleotide.


Isolation and characterization of catabolite-resistant mutants in the D-serine deaminase system of Escherichia coli K-12. Two classes of D-serine deaminase (Dsdase)-specific secondary mutants of Escherichia coli K-12 were isolated from a Dsdase low constitutive nonhyperinducible mutant as types which could grow in the presence of both D-serine and glucose. These strains contain cis dominant, nonsuppressible mutations in the dsdO (operator-initiator) region. In the first class of mutants (e.g., FB4010), Dsdase synthesis is completely insensitive to catabolite repression, and synthesis occurs at a high constitutive rate in the absence of cyclic adenosine 5'-monophosphate. In the second class (e.g., FB4005), Dsdase synthesis is partially insensitive to catabolite repression, and catabolite repression is reversed by the addition of cyclic adenosine 5'-monophosphate. Dsdase synthesis in strain FB4005 is partially independent of the cyclic adenosine 5'-monophosphate binding protein, as constitutive synthesis is reduced only 65% (relative to the cap+ strain) in strains unable to synthesize the cyclic adenosine 5'-monophosphate binding protein. Surprisingly, the constitutive rate of Dsdase synthesis is fourfold higher in all mutants of both classes than in the parent, indicating a close interrelationship between the sites of response to induction and catabolite repression.


Effect of tsl mutations in decreasing radiation sensitivity of a recA- strain of Escherichia coli K-12. It has been shown previously that the radiation sensitivity of lexA- strains of Escherichia coli K-12 can be suppressed by thermosensitive mutations (designated tsl) that are closely linked to the lexA locus and are thought to be intragenic suppressors of lexA mutations (Mount et al., 1973). When a recA mutation is crossed into a suppressed tsl- strain, the extreme radiation sensitivity usually conferred by a recA mutation is decreased, but there is no detectable change in genetic recombination deficiency. Increased resistance to UV in the tsl-reA-strains depends upon ability to synthesize active uvrA+ product.


Isolation of a catabolite repression mutant of yeast as a revertant of a strain that is maltose negative in the respiratory-deficient state. A character originating from Saccharomyces cerevisiae 1403-7A is described which interferes with maltose growth in the respiratory-deficient state. This character is inherited in an apparently non-Mendelian way, but at present no statement can be made concerning the localization of this character on a plasmid or the involvement of multiple genes. As a revertant of this character, a flaky mutant was isolated, showing a heavy flocculation during growth on liquid medium and resistance to catabolite repression for maltase, alpha-methyl-glucosidase, invertase, and succinate dehydrogenase. In wild-type cells, repression (caused by growth on 2% glucose) and derepression (caused by growth on 2% galactose) can be correlated with a lower and a higher level of cyclic 3',5'-adenosine monophosphate (cAMP), respectively. In cells of flaky mutant, growth on these carbon sources results in the same levels of cAMP as observed for the wild type. Consequently, in this mutant derepression in the presence of 2% glucose is not reflected in a higher level of cAMP.


Control of expression of the pyr genes in Salmonella typhimurium: effects of variations in uridine and cytidine nucleotide pools. The differential rate of synthesis of five of the pyrimidine biosynthetic enzymes coded for by pyrB-F, and the endogenous concentrations of the individual pyrimidine nucleotides were determined in specially constructed mutants of Salmonella typhimurium. In the mutants employed the different pyrimidine nucleotide pools may be manipulated individually during exponential growth. The results obtained indicate the following. (i) The expression of pyrB, pyrE, and pyrF is controlled by a uridine nucleotide in a noncoordinate manner. (ii) The expression of pyrC and pyrD is regulated predominantly by a cytidine nucleotide. Under all conditions investigated, their expression seems to be coordinated, even though the genes are not contiguous on the chromosome. (iii) The low-molecular-weight effectors involved in controlling the expression of the pyr genes are neither uridine 5'-monophosphate nor cytidine 5'-monophosphate, but rather the corresponding di- or triphosphates.


Regulatory factors affecting alpha-amylase production in bacillus licheniformis. Possible factors regulating alpha-mylase synthesis in wild-type Bacillus licheniformis and in mutants producing elevated levels of the enzyme were studied in terms of catabolite repression, apparent temperature-sensitive repression, induction, and culture age. The synthesis of alpha-amylase in the parent strain occurred long after the culture reached the stationary phase of growth as a result of de novo protein synthesis, occurred only at high temperature around 50 C and not below 45 C, appeared to be induced in the presence of oligosaccharides with some linkage of alpha-1,4-, beta-1,4, beta-1,6-glucosyl glucose, or alpha-1,6-galactosyl glucose, and was repressed by the addition of exogenous glucose or low-molecular-weight metabolites. The addition of cyclic adenosine 3',5'-monophosphate stimulated alpha-amylase accumulation in growing cultures of the parent strain, but neither shortened the long lap period prior to the start of alpha-amylase synthesis nor mitigated the repressive effect of glucose. Mutant strains derived from the parent strain showed variation in the pattern of alpha-amylase synthesis, and some of them such as F-12s and F-14 produced alpha-amylase constitutively and without sensitivity to catabolite repression or transient repression from the moment of cell growth. These results are discussed in relation to possible regulatory mechanisms that might account for the observed characteristics of alpha-amylase synthesis in this facultative thermophilic microorganism.


Kinectics of beta-galactosidase synthesis in Escherichia coli at 5 C. The defect in protein synthesis that is observed in Escherichia coli after transfer to low temperature was studied. For the enzyme beta-galactosidase, the elongation reactions of transcription and translation can take place slowly but normally at 5 C. The time necessary to complete the coupled synthesis of the beta-galactosidase messenger ribonucleic acid and polypeptide chain was found to be about 80 min at 5 C. From this result and from the known length of the beta-galactosidase monomer, it is possible to calculate that at 5 C one amino acid is added to the growing polypeptide chain every 4 s. The initiation of transcription of the beta-galactosidase messenger is inhibited after transfer to 5 C. This fact alone, however, cannot account for all of the phenomena observed at 5 C, because a given amount of messenger yields less enzyme at 5 C than it does at 37 C. Furthermore, in cells induced for short periods at 37 C, the capacity to synthesize beta-galactosidase after transfer to 5 C was found to accumulate linearily with the square of the time of induction. Two alternative models could account for these data. If all ribosomes that initiate translation at 37 C yield complete beta-galactosidase polypeptide chains at 5 C, then an inhibition of translation initiation after transfer to 5 C must be invoked to explain the results. If, on the other hand, a substantial portion of the ribosomes that initiate translation at 37 C do not yield complete beta-galactosidase polypeptides at 5 C, then intracistronic polarity could account for the data, and there is no need to invoke an inhibition of translation initiation at 5 C.


6-Phosphogluconate dehydratase deficiency in pleiotropic carbohydrate-negative mutant strains of Pseudomonas aeruginosa. Mutants of Pseudomonas aeruginosa, strain PAO, have been isolated that are unable to grow on mannitol, glucose, gluconate, or 2-ketogluconate, cut that exhibit wild-type growth on pyruvate, lactate, citrate, succinate, or acetate. Although some of these mutants were also unable to grow on glycerol, the mutations formed a single linkage group by quantitative transductional analysis with phage F116 on glucose minimal agar medium. Cell extracts of all mutant strains were either lacking or severely deficient in 6-phosphogluconate dehydratase activity. Glu+ transductants derived from mutant strains that retained the wild-type ability for growth at the expense of glycerol also regained the ability to grow on all C-6 compounds. Although a role for the pentose phosphate pathway in the catabolism of C6 substrates was not found, a functional Entner-Doudoroff pathway appears to be essential for the catabolism of mannitol, glucose, gluconate, and 2-ketogluconate.


Biosynthesis of branched-chain amino acids in yeast: effect of carbon source on leucine biosynthetic enzymes. The three enzymes in the leucine biosynthetic pathway of yeast do not exhibit coordinate repression and derepression in response to the carbon source available in the culture medium. Growth in an acetate medium results in derepression of the first enzyme in the pathway, alpha-isopropylmalate synthase, and repression of the second two enzymes, alpha-isopropylmalate isomerase and beta-isopropylmalate dehydrogenase, relative to the levels found in glucose-grown cells. The role of endogenous leucine pools as a mediator of these differences was investigated. The leucine pools did not differ significantly between acetate-grown and glucose-grown cells. However, an elevated endogenous leucine pool, caused by exogenous leucine in the growth medium, did decrease the rate of decay of alpha-isopropylmalate synthase activity observed when acetate-grown cells were shifted to glucose. Evidence is provided suggesting that an elevated endogenous leucine pool may increase the in vivo stability of alpha-isopropylmalate synthase under several different conditions. Studies on the kinetics of alpha-isopropylmalate synthase decay in vivo and sensitivity to leucine inhibition indicate that there are two classes of the enzyme in acetate-grown yeast cells.


Regulation of dihydrodipicolinate synthase and aspartate kinase in Bacillus subtilis. The regulation of dihydrodipicolinate synthase (EC 4.2.1.52) and aspartate kinase (EC 2.7.2.4) was studied in Bacillus subtilis 168. Starvation for lysine gave depression of one aspartate kinase isoenzyme but not of dihydrodipicolinate synthase. Strains resistant to growth inhibition by the lysine analogue thiosine exhibited constitutively derepressed synthesis of one aspartate kinase isoenzyme but had normal levels of dihydrodipicolinate synthase. The data provide strong evidence that lysine is not the signal for derepression of dihydrodipicolinate synthase. Nevertheless, dihydrodipicolinate synthase specific activity increased during sporulation, and it is suggested that this increase may result, in part, from resistance to proteolysis of that enzyme.


Coenzyme interaction with horse liver alcohol dehydrogenase. Evidence for allosteric coenzyme binding sites from thermodynamic equilibrium studies. The techniques of fluorescence enhancement, fluorescence quenching, fluorescence polarization, and equilibrium dialysis are utilized to study the binding properties of coenzyme to horse liver alcohol dehydrogenase. Polarization of fluorescence and equilibrium dialysis show that NADH binds to alcohol dehydrogenase with a stoichiometry of 6 mol per mol of enzyme, in contrast to the value of 2 determined from fluorescence enhancement measurements. NAD+ also binds with a stoichiometry of six as was determined by equilibrium dialysis. The two NADH sites which bind coenzyme more tightly and which are revealed by fluorescence enhancement measurements are designated the catalytic sites. Binding of coenzyme to the four ancillary sites does not alter the quantum yield of NADH but results in a 20% contribution to quenching of enzyme's tryptophan fluorescence. From the emission anisotropy of bound NADH of 24.0% for the additional sites and 28.1% for the catalytic sites and their relative fluorescence lifetimes at the same wavelengths of excitation and emmision, we conclude that the nicotinamide ring of NADH bound to the additional sites exhibits a freedom of motion independent of the macromolecule, while that bound to the catalytic sites is more rigidly held. Polarization of fluorescence yields negative intrinsic free energies of 9.2 and 7.5 Cal M-1 for NADH interaction with the catalytic and additional sites, respectively. Although these values are 1.3 to 2.0 Cal higher than those determined by fluorescence quenching and equilibrium dialysis, the mean Hill coefficient of 1.76 plus or minus 0.06, the titration span of 2.4 logarithmic units and coupling free energies (in magnitude and sign) are the same for all these techniques. The above difference in the intrinsic free energies are attributed largely to the different modes of interaction of excited and unexcited NADH molecules with alcohol dehydrogenase.


A study of the cytoplasmic receptors for glucocorticoids in intestine of pre- and postweanling rats. Glucocorticoids cause both enzymic and morphologic changes in the rat intestine during the time of weaning. To obtain information regarding the mechanism of these actions, we examined the cytoplasmic fraction of intestines from 18-day-old rats for the presence of specific glucocorticoid-binding proteins which are characteristics of target tissues. Incubation of slices of intestine with [3H]dexamethasone in a physiological medium at 2 degrees showed the presence of a cytoplasmic binding macromolecule with high specificity for steroids having glucocorticoid activity. The binding reaction was saturable (concentration of binding sites equals 0.24 pmol per mg of protein) and of high affinity (dissociation constant equals 9.3 nM). Binding was reversible on addition of nonlabeled dexamethasone (t 1/2 equals 5.2 hours), indicating that the usual assay procedure measured both corticosterone-filled and unoccupied binding sites. Sucrose density gradient centrifugation showed that the receptor-dexamethasone complex from intestinal cytosol sedimented at the same rate as that from liver (8.2 S). The receptor-dexamethasone complex was stable at 2 degrees for at least 24 hours in intestinal slices, but in isolated cytosol fractions there was considerable loss of binding even in the presence of high concentrations of [3H]dexamethasone. Furthermore, mixing experiments showed that the presence of cytosol from intestinal mucosa (but not from the muscle layers) caused a dissociation of dexamethasone from receptors of liver cytosol. This suggested the presence of some interfering factor in isolated mucosal cytosol and meant that quantitative studies had to be confined to intact slices. Although the reasons for the instability of steroid-receptor complexes in the presence of isolated intestinal cytosol are not understood, the instability is believed to be associated with homogenization and, therefore, is believed to have no physiological significance. Finally, the ontogenesis of cytoplasmic glucocorticoid receptors in intestinal slices was examined and the pattern compared with that in liver and lung. Receptor activity was present in intestine from late fetal life through adulthood, but concentrations were significantly higher during the first two postnatal weeks than at all other times. By contrast, receptor activity detected in cytosol prepared from rat lung was high around the time of birth, while that in liver rose steadily during the first postnatal week and remained at high levels. Thus specific receptors for glucocorticoids are present in the rat intestine during periods of both responsiveness and unresponsiveness. This suggests that although corticosteroids exert their effects through the cytoplasmic receptors, this early event in glucocorticoid action may not be a controlling step for changes in responsiveness during development.


Activation of transcription by guanosine 5'-diphosphate,3'-diphosphate, transfer ribonucleic acid, and novel protein from Escherichia coli. A protein factor TFms) that is required for ppGpp to stimulate RNA synthesis has been purified from an eluate of crude ribosomes. TFms also has the capacity to stimulate RNA synthesis without ppGpp present. Under standard conditions the action TFms and ppGpp requires uncharged tRNA. TFms and ppGpp act at inhibition to promote the formation of rifampicin-resistant or polytrI)-resistant preinitiation complexes. In the presence of rifampicin or poly(rI), tRNA is no longer required. With lambdah80dlacPs DNA as template, ppGpp together with TFms stimulated gal RNA synthesis to a much greater extent than total RNA synthesis. The stimulation of both lac and gel RNA synthesis was increased in the presence of cyclic AMP receptor and cyclic AMP.


A persistent active state of the adenylate cyclase system produced by the combined actions of isoproterenol and guanylyl imidodiphosphate in frog erythrocyte membranes. Isoproterenol plus guanylyl imidodiphosphate (Gpp(NH)p) activate frog erythrocyte adenylate cyclase to a level much higher than the sum of the activities produced by the catecholamine and the synthetic nucleotide tested separately. Propranolol, the beta-receptor blocking agent,  failed to inhibit activity when added after the enzyme system had been preincubated with both isoproterenol and Gpp(NH)p. However, if propranolol was added after only one of the two components had been added, it inhibited the effect of isoproterenol. Production of the propranolol-resistant state by treatment with isoproterenol and Gpp(NH)p did not require the presence of the productive substrate (MgATP). The activated propranolol-resistant state persisted following various treatments of the enzyme preparation including extensive washings of the membranes; considerable activity was retained even after sonication or treatment with the detergent Lubrol-PX, treatments which caused inactivation of the native enzyme. Extensive dilution of the membranes following pretreatment with isoproterenol and Gpp(NH)p did not significantly reduce to the activity of the enzyme. Readdition of isoproterenol after dilution caused some inhibition of adenylate cyclase activity, indicating apparently that the beta-receptor has not become inaccessible. In contrast, preincubation with isoproterenol alone failed to render the enzyme system refractive to propranolol, and dilution readily reduced the activity to negligibly low values. Preincubation with Gpp(NH)p alone also produced a persistent active state but the activity was much lower than that obtained throught the combined action of isoproterenol and Gpp(NH)p. The findings suggest that the hormone may be required only to facilitate the initial interaction of the enzyme with Gpp(NH)p. The differences, in this respect, between Gpp(NH)p and the more labile natural nucleotide, GTP, are discussed.


Pyridoxal phosphate-dependent conformational states of glycogen phosphorylase as probed by interconverting enzymes. The interaction between pyridoxal 5'-phosphate and the convertible serine of glycogen phosphorylase has been investigated by using: specific interconverting enzymes, phosphorylase kinase and phosphorylase phosphatase; effectors, glucose and glucose 6-phosphate; and a protein kinase and trypsin. Both phosphorylase kinase and phosphorylase phosphatase utilized the native protein while having little influence on the apoprotein. Removal of a peptide containing the critical serine residue gave phosphorylase b' from which the pyridoxal 5'-phosphate in phosphorylase has an important effect on enzymic interconversion.


The plane of cleavage in human ferrihemoglobin. I. Ultraviolet difference spectroscopy. X-ray diffraction studies have shown that hemoglobin has two predominant interfaces in the tetramer at which dissociation to dimers could occur. These interfaces have been designed as alpha1-beta1 and alpha1-beta2. There are 2 tyrosyl residues and 1 tryptophanyl residue in the alpha1-beta2- interface but only 1 tyrosyl residue in the alpha1-beta1 interface exposed to the solvent are perturbed. The ultraviolet difference spectrum between ferrihemoglobin dissociated in 1 M NaClO4 and undissociated hemoglobin revealed two negative peaks, one at 292.5 nm and another at 285 nm. This difference spectrum is due to tyrosyl and tryptophanyl residues which reside on the plane of cleavage and were exposed to 1 M NaClO4 upon dissociation. Hence, dissociation must have occurred along the alpha1-beta2 interface to yield alpha1 beta1 dimers. The deltaF degrees value extrapolated to zero salt concentration calculated on the basis of difference spectroscopy and sedimentation velocity experiments is 8.6 plus or minus 0.7 kcal per mol at pH 7.1 (K equals 4.5 times 10-7.


Stimulation of active uptake of nucleosides and amino acids by cyclic adenosine 3' :5'-monophosphate in the yeast Schizosaccharomyces pombe. In conditions of glucose starvation, the maximum velocity of the mediated transport of nonmetabolized and metabolized amino acids, uridine, adenosine, and sucrose across the plasma membrane is stimulated by a factor of two by the addition of 1 mM adenosine 3':5'-monophosphate to Schizosaccharomyces pombe 972h- wild strain, to the glucose-super-repressed and derepressed mutants COB5 and COB6, and to Saccharomyces cerevisiae strain IL 216-IA. The mediated uptake of 2-D-deoxyglucose and the apparently nonmediated uptake of guanosine are not stimulated by the cyclic nucleotide. N6,O2'-Dibutyryl adenosine 3':5'-monophosphate is also efficient, whereas theophylline, guanosine 3':5'-monophosphate, 5'-AMP, ATP, and adenosine are ineffective. The cellular ATP content of glycerol-grown S. pombe COB5 is about 10 nmol per mg of protein and is not decreased by further incubation in the starvation medium. The addition of 100 mM glucose markedly enhances transport without any increase of the cellular ATP content. The addition of antimycin A or Dio-9 decreases markedly both cellular ATP content and transport. The addition of 2.5 mM glucose to antimycin A-containing medium restores both transport is not necessarily of mitochondrial origin. The uptake of 2-D-deoxyglucose is unaffected by the respiratory inhibitors. Stimulation of uptake by cyclic adenosine 3':5'-monophosphate occurs only in glucose-deprived cells. The addition of 10 mM glucose elicits the disappearance of the stimulation and prevents the 30% decrease of the cellular adenosine 3':5'-monophosphate content produced by glucose starvation. Adenosine 3':5'-'monophosphate does not enhance the steady state ATP level but requires cellular ATP produced either by endogenous respiration or, in the absence of respiration blocked by antimycin A, by further addition of 2.5 mM glucose. Stimulation of active uptake by adenosine 3':5'-monophosphate does not require protein synthesis because the addition of cycloheximide or anisomycin does not prevent the stimulation of L-leucine uptake. In the absence of respiration, Dio-9, and ATPase inhibitor, suppresses instantaneously the cellular ejection of protons as well as the uptake of uridine and amino acids. It abolishes also the adenosine 3':5'-monophosphate-stimulated transport. In the presence of antimycin A, specific mitochondrial ATPase inhibitors such as venruricidin A do not inhibit metabolite uptakes and their stimulation by adenosine 3':5'-monophosphate. These results suggest that in these conditions, the target of Dio-9 is not the mitochondrial ATPase but a plasma membrane proton-translocating function generating an electrochemical gradient required for active transport. That adenosine 3':5'-monophosphate enhances the Dio-9-sensitive proton extrusion supports the view that the cyclic nucleotide might modulate the plasma membrane ATPase.


The mechanism of stabilization of the structure of nuclease-T by binding of ligands. The rate of unfolding of Nuclease-T at pH 8,20 degrees was determined as a function of concentration of the ligands deoxythymidine 3',5'-diphosphate (pdTp) and Ca2+ on the basis of the rate of exchange between free fragment, Nuclease-T(50-149) and labeled fragment, Nuclease-T-(50-149) incorporated in the structure of nuclease-T (Taniuchi, H. (1973) J. Biol. Chem. 248, 5164-5174). The rate constant of unfolding of unliganded Nuclease-T' was 4.6 times 10-4s-1. Those of Nuclease-T' bound with pdTp, with Ca2+, and with both pdtp and Ca2+ were 9.0 times 10-5, 1.6 times 10-4, and 2.2 times 10-5s-1, respectively. The association constants of pdTp and Ca2+ with Nuclease-T' were found to be 1.0 times 10-4 and 2.0 times 10-2 m-1, respectively. Those of pdTp with Nuclease-T' plus Ca2+ and of Ca2+ with  Nuclease-T'  plus pdTp were 4 times 10-5 and 1.4 times 10-4M-1, respectively. The calculation of free energy change on the basis of the association constants shows that the magnitude of negative free energy change involved in the binding of either of the two ligands increases by approximately 2 kcal when the other ligand is already bound. There is a correlation between the free energy change and the specifically coupled with the cooperative interacions operating throught the three-dimensional structure resulting in strengthening of the interactions throughtout the structure, including those with the ligands, without a large change in conformation.


The generation of O2-by the interaction of the hemolytic agent, phenylhydrazine, with human hemoglobin. Phenylhydrazine reacts with adult oxy- or methemoglobin in the presence of molecular oxygen to generate O2-. The mechanism of the reaction apparently differs in each case. The generation of O2- is monitored by following the reduction of ferricytochrome c or the oxidation of epinephrine.


Hapten-sandwich labeling. II. Immunospecific attachment of cell surface markers suitable for scanning electron microscopy. A hapten-sandwich procedure has been used for immunospecific labeling of cell surface antigens with markers visible by scanning electron microscopy. Antihapten antibody was used to link hapten-modified tobacco mosaic virus, bushy stunt virus, or hemocyanin to hapten-modified human erythrocytes. The antihapten antibody bridge was also used to link the hapten-virus marker to hapten-modified antibodies against mammary tumor virus on mouse mammary tumor cells, or against immunoglobulin receptors on mouse splenic lymphocytes. In all cases, labeling was highly specific. With this technique, it is possible to (a) compare morphological features of cells bearing differing cell surface antigens, and (b) examine the arrangement of specific antigenic sites on a cell surface or their distribution relative to membrane structures such as microvilli.


Further characterization of embryonic tendon fibroblasts and the use of immunoferritin techniques to study collagen biosynthesis. Morphological studies were carried out on fibroblasts from chick embryo tendons, cells which have been used in a number of recent studies on collagen biosynthesis. The cells were relatively rich in endoplasmic reticulum and contained a well-developed Golgi complex comprised of small vesicles, stacked membranes, and large vacuoles. Techniques were then devised for preparing cell fragments which were penetrated by ferritin-antibody conjuates but which retained the essential morphological features of the cells. Finally, the new procedures were employed to develop further information as to how collagen is synthesized. As reported elsewhere, preliminary studies with ferritin-labeled antibodies showed that prolyl hydroxylase was found in the endoplasmic reticulum of freshly isolated fibroblasts and that procollagen is found in both the cisternae of the endoplasmic reticulum and the large Golgi vacuoles. In the experiments described here, the cells were manipulated so that amino acids continued to be incorporated into polypeptide chains but assembly of the molecule was not completed because hydroxylation of prolyl and lysyl residues was prevented. The results indicated that these manipulations produced no change in the distribution of prolyl hydroxylase. Examination of the cells with ferritin conjugated to antibodies which reacted with protocollagen, the unhydroxylated form of procollagen, demonstrated that protocollagen was retained in the cisternae of the endoplasmic reticulum during inhibition of the prolyl and lysyl hydroxylases. Assays for prolyl hydroxylase with an immunologic technique demonstrated that although the enzyme is found within the endoplasmic reticulum, it is not secreted along with procollagen. The observations provided further evidence for a special role for prolyl hydroxylase in the control of collagen biosynthesis.


Detection by means of cell fusion of macromolecular synthesis involved in the reconstruction of the nuclear envelope in mitosis. Using the cultured Chinese hamster cell line Don, G1 or S or a mixture of late-S/G2 cells were prepared by release from metaphase arrest. Metaphase (M) cells were also obtained by mitotic arrest of log-phase cultures with Colcemid and held in metaphase; such M cells remained untreated with any other compound and were termed standard M cells. When interphase (I) cells were fused at pH 8.0 and 37 degrees C with standard cells in the presence of Colcemid by means of UV-inactivated Sendai virus, binucleate interphase-metaphase (I-M) cells were obtained. In a given I-M cell there occurred within 30 min after fusion either prophasing of the I nucleus or formation of a nuclear envelope (NE) around the chromosomes. About 20%  of early G1 cells, 35% of cells at the G1/S boundary, 50% of S cells, and 70% of late S/G2 cells could induce NE formation. If, before fusion, cycloheximide (CHE), an inhibitor of protein synthesis, was present during release from M arrest, the cells entered G1 but not S. About 20% of such early G1 cells, like the untreated early G1 cells, had the capacity to induce NE formation during subsequent fusion. If the cells were blocked in S with 5 mM thymidine (TdR), At least 80% of these cells could induce NE formation during subsequent fusion, but in the presence of both TdR and CHE only 35% could do so. It appeared, therefore, that protein synthesis in interphase was required for NE formation. Experiments with actinomycin D indicated that RNA synthesis was also necessary for acquisition of NE-inducing capacity. About 35% of G1 cells from confluent monolayers had the NE-inducing capacity, but prolonged exposure to CHE reduced their number to 8% . Removal of CHE restored the ability while the cells still remained in G1. This result indicated that continuing protein synthesis in the G1 cell was needed for NE formation subsequent to fusion. The fact that macromolecular synthesis must occur in the I cell before fusion if NE formation was to occur in the fused I-M cell lends further support to evidence adduced earlier that this phenomenon is a normal mitotic event. Prophasing of the I nucleus in I-M cells did not appear to be dependent on macromolecular synthesis in the I cell; earlier results from this laboratory showed, however, that protein synthesis in the prior G2 period of the M cell of the I-M pair was required for prophasing.


Cell surface changes and Rous sarcoma virus gene expression in synchronized cells. We have investigated whether cell surface changes associated with growth control and malignant transformation are linked to the cell cycle. Chicken embryo cells synchronized by double thymidine block were examined for cell-cycle-dependent alterations in membrane function (measured by transport of 2-deoxyglucose, uridine, thymidine, and mannitol), in cell surface morphology (examined by scanning electron microscopy), and in the ability of tumor virus gene expression to induce a transformation-specific change in membrane function. We reach the following conclusions: (a) The high rate of 2-deoxyglucose transport seen in transformed cells and the low rates of 2-deoxyglucose and uridine transport characteristic of density-inhibited cells do not occur in normal growing cells as they traverse the cell cycle. (b) Although there are cell cycle-dependent changes in surface morphology, they are not reflected in corresponding changes in membrane function. (c) Tumor virus gene expression can alter cell membrane function at any stage in the cell cycle and without progression through the cell cycle.


Externally disposed plasma membrane proteins. I. Enzymatic iodination of mouse L cells. The enzymatic iodination technique has been utilized in a study of the externally disposed membrane proteins of the mouse L cell. Iodination of cells in suspension results in lactoperoxidase-specific iodide incorporation with no loss of cell viability under the conditions employed, less than 3% lipid labeling, and more than 90% of the labeled species identifiable as monoiodotyrosine. 90% of the incorporated label is localized to the cell surface by electron microscope autoradiography, with 5-10% in the centrosphere region and postulated to represent pinocytic vesicles. Sodium dodecylsulfate-polyacrylamide gels of solubilized L-cell proteins reveals five to six labeled peaks ranging from 50,000 to 200,000 daltons. Increased resolution by use of gradient slab gels reveals 15-20 radioactive bands. Over 60% of the label resides in approximately nine polypeptides of 80,000 to 150,000 daltons. Various controls indicate that the labeling pattern reflects endogenous membrane proteins, not serum components. The incorporated 125-I, cholesterol, and one plasma membrane enzyme marker, alkaline phosphodiesterase I, are purified in parallel when plasma membranes are isolated from intact, iodinated L cells. The labeled components present in a plasma membrane-rich fraction from iodinated cells are identical to those of the total cell, with a 10- to 20-fold enrichment in specific activity of each radioactive peak in the membrane.


Externally disposed plasma membrane proteins. II. Metabolic fate of iodinated polypeptides of mouse L cells. The fate of the L-cell plasma membrane proteins labeled by enzymatic iodination was studied. The disappearance of label from growing cells exhibits a biphasic behavior, with 5-20% lost rapidly (t1/2 similar to 2 h) and 80-90% lost relatively slowly (t1/2 similar to 25-33 h). The loss is temperature dependent and serum independent, and is accompanied by the appearance of 51% (125-I)monoiodotyrosine (MIT) in the medium by 47 h. A variable amount (1-14%) of acid-insoluble label can be recovered in the medium over 47 h. Sodium dodecyl sulfate (SDS)-polyacrylamide gel labeling patterns from cells cultured up to 48 h after iodination reveal no change in the relative distribution of radioactivity, indicating similar rates of degradation for most of the labeled membrane proteins. The fate of the labeled membrane proteins was studied at various times after phagocytosis of nondigestible polystyrene particles. Iodinated L cells phagocytose sufficient 1.1 mum latex beads in 60 min to interiorize 15-30% of the total cell surface area. Electron microscope autoradiography confirmed that labeled membrane is internalized during phagocytosis. The latex-containing phagocytic vacuoles are isolated by flotation in a discontinuous sucrose gradient. 15-30% of the total incorporated label and a comparable percentage of alkaline phosphodiesterase I activity (PDase, a plasma membrane enzyme marker) are recovered in the phagocytic vacuole fraction. Lysosomal enzyme activities are found in the latex vacuole fraction, indicating formation of phagolysosomes. SDS gel analyses reveal that all of the radioactive proteins initially present on the intact cell's surface are interiorized to the same relative extent. Incorporated label and PDase activity disappear much more rapidly from the phagolysosomes than from the whole cell. In the phagolysosomal compartment, greater than 70% of the TCA-precipitable labeled proteins and all of the PDase activity are lost rapidly (t1/2 equals 1-2 h) but similar 30% of the labeled proteins in this compartment are degraded with a 17-20 h half-life. The slowly degraded label is due to specific long-lived polypeptides, of 85,000 and 8,000-15,000 daltons, which remain in the phagolysosomal membrane up to 40 h after phagocytosis.


Gas-liquid chromatography of carotenoids and other terpenoids. The retention behaviour of over seventy terpenoids on three silicone polymer liquid phases under both isothermal and temperature-programmed conditions is reported. Terpenoids with conjugated unsaturation (e.g., carotenoids) were hydrogenated prior to analysis in order to prevent thermal decomposition. Analyses of the acetates and TMS ethers of both the natural hydroxycarotenoids and their perhydroderivatives are also reported. In addition, a system is described for the routine analysis of terpenols, including those whose pyrophosphates are intermediates in sterol and carotenoid biosynthesis.


Blood testosterone values in patients with congenital virilizing adrenal hyperplasia. To evaluate the usefulness of blood testosterone (T) in monitoring the effects of therapy in congenital virilizing adrenal hyperplasia due to 21- or 11- hydroxylation defect (CVAH), T levels were measured on 45 occasions in 13 patients with CVAH; 32 urinary 17-ketosteroid levels and 31 preganetriol values were available for comparison. Bone age levels, growth data, and medication are listed to help assess the clinical state of the patient at the time of each T determination. Blood T values were above normal for age and sex in untreated patients with CVAH and declined with glucocorticoid suppression. A blood T value of 20 ng/100 ml appeared to distinguish between well-controlled cases and those with inadequate steroid suppression. Serial measurement of blood T in girls and in prepubertal boys with CVAH provides assistance in evaluating chemical control of the disease, particularly when accurate 24-h urine collections cannot be obtained for 17-ketosteroid and pregnanetriol assessments.


Interaction of delta-5-androstene-3beta, 17beta-diol with estradiol and dihydrotestosterone receptors in human myometrial and mammary cancer tissue. Specific receptor binding of estradiol (E-2) and dihydrotestosterone  (DHT) was studied in human myometrial tissue and in human mammary cancer tissue. The inhibition of binding for E-2 and DHT by E-2, testosterone (T), DHT, dehydroepiandosterone (DHEA), dehydroepiandrosterone-sulfate (DHEA-S), androstendione (A) and 5-androstene-3beta, 17beta-diol (Adiol) was tested with the use of dextran-coated charcoal separation of bound and free E-2, respectively, and DHT. The percentage of binding inhibition was calculated with reference to the inhibition obtained with nafoxidine in a molar concentration ratio of 1,000 for E-2 binding, respectively, with cyproterone acetate in a molar concentration ratio of 10,000 for DHT binding. In 15 samples of myometrium tested, receptors were found for both E-2 and DHT. From 19 samples of mammary carcinoma tissue one showed no binding activity, three samples did bind E-2 only, five samples DHT only, and ten samples showed binding of both steroids. A 50% inhibition of E-2 binding, in myometrial as well as in tumor tissue, required a molar concentration ratio of 40 for Adiol, of more than 2,000 for DHEA. No significant inhibiting activity could be found for A up to a molar concentration ratio of 10,000 and for DHEA-S up to 40,000. With regard to DHT binding, Adiol is more active than E-2 and less active than T. Of the substances tested Adiol is therefore the only one which exerts a significant inhibiting influence at a molar ratio not far beyond the physiological range. This signifies that Adiol might interfere at the receptor level in the estrogenic stimulation of mammary cancer cells.


Regulation of human chorionic gonadotropin (hCG) secretion by serum and dibutyryl cyclic AMP in malignant trophoblast cells in vitro. Human chorionic gonadotropin (hCG) secretion was studied in human malignant trophoblast cells (Jar line) in continuous culture. Radioimmunoassayable hCG in the cells and in the daily culture fluid was increased for at least 3 days by 10% newborn calf serum and by 1 mN N-6, 0-2'-dibutyryl cyclic adenosine 3', 5'-monophosphoric acid (dbcAMP) plus 1 mM theorphylline. Incubation of the cells in the presence of serum, dbcAMP and theorphylline resulted in additive stimulation of hCG secretion after 1 day. After 2 or 3 days, a supra-additive stimulation was observed, which was prevented by Actinomycin D. When cells were preincubated for 2 days in the absence of serum but with dbcAMP plus theorphylline, subsequent addition of serum resulted in supra-additive stimulation of hCG secretion within a single day; the continued presence of dbcAMP plus theophylline was not necessary for this stimulation by serum. These findings suggested that dbcAMP activates a slow process requiring RNA synthesis, resulting in increased hCG secretion. Serum appears to protect the hCG synthesizing system from degradation.


Immunochemical heterogeneity of calcitonin in plasma. Calcitonin was measured in the plasma of 13 patients with medullary throid carcinoma and one patient with a calcitonin-producing islet cell carcinoma of the pancreas. The hormone was measured by the simultaneous application of two calcitonin antisera which had differing specificity. Calcitonin measurements were also made of gel filtration (Bio Gel P30) fractions of plasma samples. Although the two antisera were of comparable sensitivity for the measurement of human calcitonin standards, they reacted differently with the calcitonin in the plasma samples. One antiserum (LD-1) gave consistently higher estimations of hormone concentration in the plasma of patients with medullary thyroid carcinoma than the other (LD-26). By contrast, the concentration of calcitonin from the islet cell carcinoma of the pancreas was higher in the LD-26 assay. Multiple gel filtration peaks of immunoreactive calcitonin activity were present in both thyroidal and nonthyroidal calcitonin. Furthermore, the two different antisera identified differing immunochemical peaks of calcitonin activity for agiven plasma sample. These findings demonstrate the presence of immunochemical heterogeneity in plasma calcitonin and suggest the presence of immunological differences between thyroidal and nonthyroidal calcitonin.


Effects of glucocorticoids on pituitary hormonal responses to hypoglycemia. Inhibition of prolactin release. The characteristics of pituitary hormonal responses to insulin-induced hypoglycemia were investigated in 16 normal men. In all subjects, levels of blood sugar fell below 35 mg/100 ml. A statistically significant increase in mean plasma levels of prolactin, ACTH, cortisol and growth hormone was observed. Prolactin levels increased in all subjects but one; individual peak values were 1.4 minus 8.4 times greater than base levels. The kinetics of prolactin, GH and ACTH responses were similar; in particular, the onset of release (25 min) of prolactin, GH and ACTH was similar. After dexamethasone administration, insulin tolerance tests wererepeated in a number of subjects using adequate amounts of insulin to achieve hypoglycemia equivalent to that obtained in the control experiments. The administration of 1 mg of dexamethasone the evening before the test suppressed basal levels of ACTH and cortisol and the ACTH-but not the cortisol-response to hypoglycemia. Both basal levels of prolactin and prolactin response to hypoglycemia were significantly lowered but growth hormone response was not modified by administration of 1 mg of dexamethasone. The administration of larger doses of dexamethasone (1 mg every 6 h for 2 days) almost completely suppressed basal levels of ACTH, cortisol and prolactin, as well as the hypoglycemia-induced release of these hormones. In contrast, the growth hormone response to hypoglycemia was only partially inhibited. These findings demonstrate that both basal secretion and hypoglycemia-induced release of prolactin, ACTH, cortisol and growth hormone are suppressible by glucocorticoids.


Free cortisol index: a rapid and simple estimation of free cortisol in human plasma. A rapid and simple method for the estimation of free (nonprotein-bound) cortisol in human plasma is described. Total plasma cortisol (F) was determined by a competitive protein binding assay. An estimate of the saturation of Corticosteroid Binding Globulin was obtained by the use of "charcoal cortisol uptake" (CFU). "Charcoal cortisol uptake ratio" (CFUR) was defined as the ratio of the CFU of the unknown plasma to that of a reference serum pool. Free cortisol index (FFI) was calculated as (total plasma F) times (CFUR). Percent free cortisol and free cortisol concentration (FF) was determined by equilibrium dialysis at 37 C. 169 plasma samples with an F range of 0.8-61.2 mug/100 ml from 18 normal, 10 ACTH-stimulated, 17 estrogen-treated and 12 pregnant subjects were analyzed. A highly significant correlation between FFI and FF was found (r = 0.952). Inter-assay coefficients of variation were 7% for total plasma F and 3.5% for CFU. The method allows the rapid processing of large numbers of samples and can be performed on 0.2 ml of plasma.


Growth hormone release after synthetic 1-24 ACTH: effects of estrogen and sex. Recent reports have demonstrated that growth hormone (GH) is inconsistently released after intravenous administration of synthetic 1-24 ACTH. This study was designed to evaluate the role of estrogens in mediating this response. 250 mug of synthetic 1-24 ACTH were administered to 8 men in 12 studies and 6 women in 11 studies. None of the men exhibited a rise in GH after 1-24 ACTH, while the women exhibited a significant increase. Pretreatment of 5 of these men with 100 mug of ethinyl estradiol daily for 3 days did not alter GH response from the initial studies. Pretreatment with 10 mg of diethylstilbesterol daily for 3 days, however, resulted in a rise in GH which was similar to the female group. It is concluded that the variable GH responses to synthetic 1-24 ACTH may be in part due to prevailing concentrations of sex steroids and their effect on the hypothalamic-pituitary GH release mechanism.


Antagonism of the antibacterial action of some penicillins by other penicillins and cephalosporins. There are many examples of two penicillins acting synergistically, usually by one competitively inhibiting beta-lactamase, thus protecting the other from inactivation. There are few reports on penicillins antagonizing each other. Eight strains of three genera (Proteus, Escherichia, Pseudomonas) isolated at Boston City Hospital or Institut Pasteur, Paris, showed antagonism of carbenicillin or ampicillin by cephaloridine, cloxacillin, or 6-aminopenicillanic acid. Broth dilution tests showed that with seven of the eight strains the minimum inhibiting concentration (MIC) of the more active antibiotic was increased by 800-6,400% by low concentrations (often one-tenth the MIC) of the antagonist, whereas higher concentrations of "antagonist" were not as antagonistic, This suggested that two or more receptor sites of action for penicillins were present; the antagonist thus blocks the antibacterial action at the more sensitive site but acts additively with the antagonized antibiotic at the less sensitive site. The possibility that the mechanism of antagonism was induction of inactivating enzymes (beta-lactamase, penicillin acylase) was studied in two strains(one Escherichia coli and one Proteus rettgeri), and two antagonists were studied in detail. With E. coli cephaloridine was a poorer inducer of beta-lactamase than were the antagonized antibiotic and 6-aminopenicillanic acid. From these organisms, the good inducers of a beta-lactamase that acted on benzylpenicillin did not induce enzymes that inactivated carbenicillin. Thus, the mechanism of antagonism was not due to beta-lactamase induction.


Prevention of gram-negative bacillary pneumonia using polymyxin aerosol as prophylaxis. II. Effect on the incidence of pneumonia in seriously ill patients. All 744 patients admitted to a Respiratory-Surgical Intensive Care Unit (RSICU) were included in a prospective study of the effects of a polymyxin (2.5 mg/kg body wt/day in six divided doses) or a placebo aerosol sprayed into the posterior pharynx and tracheal tube (if present), during 11 alternating 2-mo treatment cycles. The incidence of upper airway colonization in the RSICU with Pseudomonas aeruginosa was 1.6% during the polymyxin treatment cycles (total 374 patients) and 9.7% during the placebo cycles (370 patients) (X2 equals 23.2, P less than 0.01). 3 patients in the RSICU acquired Pseudomonas pneumonia, as defined by independent "blinded" assessors, during the polymyxin cycles while 17 acquired a Pseudomonas pneumonia during the placebo cycles (X2 equals 10.2, P less than 0.01). The overall mortality was similar in both placebo and polymyxin-treated groups (12.2 vs. 12.0%). Systemic antibiotic usage was similar in the different cycles; 49% of patients in the placebo and 53% in the polymyxin-treated groups received systemic antibiotics while in the RSICU.


Collagen in the human lung. Quantitation of rates of synthesis and partial characterization of composition. The presence of collagen in lung is fundamental in normal lung structure and function. Methods have been developed to examine human fetal and adult lung collagen with respect to its composition and synthesis. The second trimester fetal lung has a large number of cells per unit lung mass (36.6 plus or minus 2.7 mug DNA/mg dry wt) and relatively small amounts of collagen (17.0 plus or minus 5.3 mug collagen/mg dry wt). The number of cells per unit lung mass in the adult lung (11.1 plus or minus 3.4 mug DNA/mg dry wt) is 30% of the number of cells in the fetal lung, but the adult has 11 times more collagen (196 plus or minus 25 mug collagen/mg dry wt). The composition of fetal lung collagen can be partially characterized by extraction with salt at neutral pH, acetic acid, or guanidine. The extracted chains, representing 10% of the total lung collagen, chromatograph as alpha1 and alpha2 chains, each with a mol wt of 100,000 and an animo acid composition characteristic for collagen but not specific for lung. Short-term explant cultures of fetal and adult lung synthesize alpha chains which can be isolated by ion-exchange chromatography. These chains, representing 30-40% of the total collagen synthesized by the explants, coelectrophorese with extracted collagen chains on acrylamide gels: they are destroyed by clostridial collagenase and they have a mol wt of 100,000. Although the composition of the collagen synthesized by these explants can be only partially characterized, the rate of synthesis of both collagen and noncollagen protein can be quantitated. In fetal lung, 4.0 plus or minus 1.2% of the amino acids incorporated into protein per hour are incorporated into collagen. In normal adult lung, this percentage (4.2 plus or minus 0.9%) is remarkably similar. These values are almost identical to the relative rate of collagen synthesis in rabbit lung in the same age range. This technology should be applicable to answer specific questions regarding collagen synthesis and degradation in human lung disease.


Treatment and control of neonatal diarrhea in calves. Treatment and control of acute neonatal diarrhea in calves are outlined and discussed. The difficulty in making a definitive etiological diagnosis makes effective treatment and control also difficult and largely empirical. Physiological events in calves with diarrhea are known, and fluid therapy is directed toward treating dehydration and acidosis. Whether affected calves should receive antibacterial agents orally is an open question. Principles of control of diarrhea in calves are outlined and discussed.