Morphological and biochemical differentiation in RSV transformed chick embryo myoblasts. Chick embryo myoblasts have been transformed with a temperature sensitive mutant of Rous Sarcoma virus (RSV ts68). At permissive temperature (36 degrees C) it is shown that transformed myoblasts have lost their ability to form myotubes as well as to express the biochemical markers of myogenic differentiation. Upon a shift to the non-permissive temperature (41 degrees C), the normal program of differentiation is restored; myotubes are formed which express muscle specific proteins.


Importance of apolipoproteins in lipid metabolism. Lipids, which serve as a source of energy and are an important constituent of cell membrane structure, are readily stored in the body. By definition they are insoluble in water. Specific proteins called apolipoproteins interact with lipids to form soluble lipid-protein complexes called lipoproteins. It is in this form that the major lipids--cholesterol, triglyceride and phospholipid--circulate in plasma. Unesterified fatty acids, another major lipid group, are bound to albumin in the circulation. The plasma lipoproteins are complex macromolecules composed of lipids, apolipoproteins and carbohydrates. The relative proportions of these components differ markedly between lipoprotein classes. Hyperlipidemia is a term used for increased concentrations of plasma cholesterol and/or triglycerides. Any one plasma lipid is present in several types of lipoproteins. Thus, hyperlipidemia implies the presence of hyperlipoproteinemia. The latter has important therapeutic implications. Most of the recent attempts at classification have been directed at the lipoprotein level of plasma lipid organization. Decreased concentrations of lipids in plasma can be achieved by altering the rates of metabolism of lipoproteins. Decrease in lipoprotein synthesis, increased catabolism or impaired release from cells into the blood stream may all result in a decrease of plasma lipids. Drugs which affect one or more of these factors are used to treat hyperlipoproteinemia. In order to elucidate the mechanism of action of hypolipidemic drugs it is necessary to understand the lipoprotein defect at the molecular level. This requires a more detailed knowledge of lipoprotein metabolism than is presently available for most of the hyperlipoproteinemias. This paper will review some of the generally accepted properties of the plasma lipoproteins, describe some difficulties which hamper the understanding of lipoprotein metabolism, and identify possible mechanisms by which drugs may affect lipoprotein metabolism.


Cytochrome P-450 distribution in rat liver and the effect of sodium phenobarbitone administration. A microspectrophotometric method for assaying cytochrome P-450 in fresh 24 micrometer unfixed cryostat sections of rat liver has been developed. When used to assay this cytochrome in sections of microsomal preparations it has yielded results equivalent to those obtained by the conventional spectrophotometric assay of the same preparations. Random measurements made throughout sections of liver have given mean values for cytochrome P-450 concentrations which are twice those measured in microsomes prepared from the livers of the same animals (not corrected for the yield in the homogenate). Measurements of the cytochrome P-450 content of liver cells by the microspectrophotometric method show that in liver from male Wistar rats, cells nearer to the central veins contain up to twice as much cytochrome P-450 as those nearer to the portal tract (mean cell concentrations of 26.4 (+/-4.4) mumol/l and 17.5 (+/-3.0) mumol/l respectively). In the livers from similar rats, killed at the same time, but which has received 1 mg/ml sodium phenobarbitone in their drinking water for one week, the cells near the central vein contained up to five times as much cytochrome P-450 as those near the portal tract (mean cell concentrations of 77.3 (+/-25.0) mumol/l and 28.3 (+/-9.6) mumol/l respectively). The results show a selective increase in cytochrome P-450 content by the cells in the centrilobular region after treatment with sodium phenobarbitone and a smaller increase by some of the cells in the periportal region.


The association between mutagenicity and adduct formation of 1,2,7,8-diepoxyoctane and 1,2,5,6-diepoxycyclooctane. The mutagenicity of 1,2,5,6-diepoxycyclooctane (DECO) and 1,2,7,8-diepoxyoctane (DEO) was investigated using diploid Chinese hamster lung cells. 6-thioguanine (6-TG) resistance was used as the marker for mutagenicity testing: DEO was found to be genetically active; DECO, on the contrary, totally inactive. DEO readily formed adducts with radiolabeled nucleotides, while DECO failed to do so, as demonstrated through thin-layer chromatography (TLC) and the shift of the ultraviolet absorption maximum in DEO/nucleotide mixtures. The difference between the two compounds in chemical and genetic activities was attributed to their molecular conformations and the resulting differential flexibilities and adduct-forming abilities. Association between mutagenicity and adduct formation was conclusive.


[Evidence for a Na+/NH4+ exchange in the gill of trout adapted to sea water: adrenergic control]. A Na+/NH4+ exchange similar to that characterizing the fish gill in fresh water was shown to function in the trout adapted to sea water with the help of the head perfusion technique. This exchange stimulated by adrenaline through beta adrenoreceptors and inhibited by amiloride added to the external medium.


[Use of Cowan strain I of Staphylococcus aureus for radio-immunological determination of retrovirus proteins]. The use of Staphylococcus aureus for the radio-immunoassay of C-type virus polypeptides provided very specific results and proved to present several advantages over the classical methods of precipitation of immune complexes.


Effects of substrates on tissue metabolic changes in the isolated rat heart during underperfusion and on release of lactate dehydrogenase and arrhythmias during reperfusion. In Langendorff-perfused rat hearts, the perfusion pressure was reduced from 100 cm H2O to 20 cm H2O for 30 minutes to produce a model of global ischemia with a residual oxygen uptake. The release of lactate dehydrogenase (LDH) and the occurrence of ventricular arrhythmias during reperfusion were dependent on the substrate. Glucose-perfused hearts had the highest rates of glycolytic ATP production (2.5 mumol/g per min) during ischemia with normal contents of tissue cyclic adenosine 3',5'-monophosphate (cAMP) and, during reperfusion, the release of LDH was lowest and severe ventricular arrhythmias did not occur. In pyruvate-perfused hearts, glycolysis was inhibited during ischemia, the rate of production of glycolytic ATP was only 0.5 mumol/g per min. and tissue cAMP doubled; during reperfusion, LDH release was 14-fold higher and ventricular arrhythmias were more severe. Total tissue contents of ATP and phosphocreatine were similar in glucose- and in pyruvate-perfused hearts. In hearts perfused with acetate, there was virtually no glycolytic ATP synthesized during the last 5 minutes of ischemia and cAMP increased further. Acetate-  and palmitate-perfused hearts showed greatest release of LDH and had severest arrhythmias during reperfusion, suggesting that it was the metabolic and not the detergent effects of palmitate that were operating. Lipolysis was not a major factor in the cause of reperfusion LDH release. A role of glycolytic ATP in the maintenance of membrane integrity is postulated.


Multi-laboratory comparison of three heparin-Mn2+ precipitation procedures for estimating cholesterol in high-density lipoprotein. Plasma high-density lipoprotein is commonly estimated by measuring the cholesterol remaining in plasma supernatant solutions after other lipoproteins, which contain apolipoprotein B, are precipitated with heparin and Mn2+. The method (method I) now in use by the Lipid Research Clinics, in which Mn2+ is at 46 mmol/liter final concentration, is reasonably accurate, but precipitation and sedimentation of lipoproteins other than high-density lipoproteins is often incomplete. We evaluated two modifications of method I. In method II, the Mn2+ concentration was doubled; the second modification (method III) included the increased Mn2+ concentration in a combined heparin Mn2+ reagent, decreased sample volume (2 ml), and a shorter incubation time (10 min at room temperature). The percentages of samples with turbid supernates (i.e., incomplete sedimentation) by methods I, II, and III were 9, 3, and 2%, respectively. Among non-turbid supernates, the percentages of samples containing measurable apolipoprotein B (incomplete precipitation) were 79, 19, and 16%, respectively. We conclude that method III is the most convenient and accurate of the three procedures.


Heparin--Mn2+ quantitation of high-density-lipoprotein cholesterol: an ultrafiltration procedure for lipemic samples. We describe a modified heparin--Mn2+ procedure for high-density-lipoprotein cholesterol quantitation, especially in lipemic samples. High-density-lipoproteins may be estimated as cholesterol remaining in plasma supernates after precipitation of other lipoproteins by heparin and Mn2+ treatment. However, in lipemic samples or those from non-fasting individuals, the lower density of the precipitated chylomicrons, very-low-, and low-density-lipoproteins frequently prevents their sedimentation by the usual low-speed centrifugation, and high-density-lipoprotein cholesterol thus is overestimated in the resulting turbid supernates. Sedimentation is improved by a twofold increase in Mn2+ concentration to 92 mmol/liter. The procedure reported here produced clear supernates in more than 95% of samples tested. Any remaining turbid supernates can be cleared by a simple, convenient ultrafiltration technique. The filtration removed essentially all of the very-low- and low-density-lipoproteins without removing appreciable amounts of high-density-lipoproteins.


Cholesterol in high-density lipoprotein: use of Mg2+/dextran sulfate in its enzymic measurement. We describe a method for measuring high-density lipoprotein cholesterol. MgCl2 and dextran sulfate are used to precipitate all low-density and very-low-density lipoproteins. The supernate contains only high-density lipoproteins, the cholesterol concentration of which is estimated by an enzymic method, with a discrete analyzer (Abbott Bichromatic Analyzer). Concentration and instrument response are linearly related to 50 mg/liter. The precision of the method is excellent in the range of clinical interest (100 to 1000 mg of cholesterol per liter). The precision and efficiency of the precipitation are shown at various concentrations of high-density lipoprotein cholesterol. The method was compared to that of two laboratories in the Cooperative Lipoprotein Phenotyping Study group by testing a number of split samples, and agreement was good.


Biochemical properties of tartrate-resistant acid phosphatase in serum of adults and children. Spectrophotometry of total acid phosphatase activity in children's sera showed an average value of 22.4 +/- 2.9 and 7.4 +/- 0.8 U/liter, for the hydrolysis of p-nitrophenyl phosphate and alpha-naphthyl phosphate, respectively. Analyses of "band 5b", after electrophoresis on acrylamide gel, gave even higher values. The values for children's sera were much higher than those for sera from adults. The multiplicity of acid phosphatases in sera of children and adults was studied by electrophoresis on acrylamide gel and by chromatography on CM-Sepharose. Both methods showed the major acid phosphatase in children's sera to be an acid pyrophosphatase, band 5b. Its catalytic properties are indistinguishable from the enzyme previously isolated from the spleen of leukemic reticuloendotheliosis.


Enzymic determination of cholesterol in serum lipoproteins separated by electrophoresis. We describe a reliable, straightforward procedure for measuring the cholesterol content of serum lipoproteins separated by electrophoresis on cellulose acetate. The lipoprotein fractions are made visible by use of an enzymic reagent and then quantitated by densitometry. Standard electrophoresis equipment is used and the procedure requires just over 1 h for completion. All major fractions except chylomicrons are detected readily. Accuracy and precision agree favorably with results reported for generally accepted methods. Concentration and color development are linearly related to cholesterol concentrations up to 1.5 g/liter in a given lipoprotein fraction. We recommend this method for use in assessing high-density lipoprotein cholesterol and as an aid in lipoprotein phenotyping.


Laboratory standardizatin in an international study: the Kaunas--Rotterdam intervention study (KRIS). Laboratory results obtained in different laboratories over lengthy periods of time usually are difficult to compare. In cooperative long-term studies where such results must be pooled, thorough standardization of methods is vital. We describe a program in which comparable plasma cholesterol and glucose analyses have been obtained, by simple methods. In the Netherlands and the Soviet Union in close collaboration with the Center for Disease Control, Atlanta, Ga., U.S.A. The two laboratories produced glucose values (direct o-toluidine reaction) within 2% of the target reference values and cholesterol results (direct Liebermann-Burchard reaction) with a consistent 6-8% positive bias over the reference method values. Intralaboratory precision was subject to preset acceptance limits. The use of common control materials, exchange of patient samples, and on-site comparison of all details of laboratory procedures are vital tools in standardization efforts. A laboratory protocol that included quality requirements and rejection criteria was developed and proved to be indispensable. The experience gained should be useful in standardizing inter-laboratory results in similar studies.


Marked hyperamylasemia associated with carcinoma of the lung. We present a case of marked hyperamylasemia associated with undifferentiated small cell carcinoma of the lung. The serum alpha-amylase had an electrophoretic mobility similar to that of salivary gland enzyme (s-type), and that in tissue extracts from the lung tumor and metastatic skin nodules showed similar migration. No evidence of a salivary or pancreatic cause of hyperamylasemia was found at autopsy, and macroamylasemia was excluded. We suggest that the strikingly increased serum alpha-amylase activity was a result of ectopic production of this enzyme by tumor. We compare results for this case to other published reports.


Formation of vitamin D metabolites from 3H- and 14C-radiolabelled vitamin D-3 in chronic liver diseases. Four of the eight patients studied were vitamin D replete and 4 vitamin D depleted as judged by serum 25-hydroxy vitamin D (25-OHD) concentration. Three of the 4 vitamin D depleted patients (including 2 with histological osteomalacia) formed radioactive 1,25-dihydroxycholecalciferol. One of the four vitamin D replete patients formed 1,25-dihydroxycholecalciferol but all formed 24,25-dihydroxycholecalciferol. This study suggests that patients with liver disease form dihydroxy vitamin D metabolites in an appropriate manner.


Selective precipitation of very low density lipoproteins from fasting sera by heparin and manganese ions. Complete and discrete precipitation of very low density lipoproteins (VLDL) from fasting sera required heating at 40 degrees C for 60 min in the presence of 0.05 M manganous ions and heparin in a concentration dependent upon the VLDL content. The minimum polyanion concentration, employed with VLDL contents less than 1.0 g/l, was 85 mg/l; an increment of 5 mg/l was required for each 1.0 g/l increase in VLDL content. The products isolated by this procedure had electrophoretic, immunochemical and ultracentrifugal characteristics skin to those of native VLDL and were slightly contaminated with albumin. The reaction conditions did not affect adversely the subsequent precipitation of low density lipoproteins.


Prenatal diagnosis of Gaucher's and Niemann-Pick diseases. Assays of glucocerebrosidase and sphingomyelinase in tissue cultures using natural substrates. Prenatal diagnosis has been successfully achieved by enzyme assays in cultured amniocytes in three high risk pregnancies for Gaucher's disease and three for Niemann-Pick disease type A. [14C]Stearic acid glucocerebroside and [3H]-dihydrosphingomyelin were used as substrates for glucocerebrosidase and sphingomyelinase activity measurements, respectively. Values for the above two enzyme levels in cultured amniotic fluid cells of normal controls and in the pregnancies at risk are presented. The diagnosis made in utero in one fetus affected with Niemann-Pick disease was subsequently confirmed following abortion (at 19 weeks gestation), by the specific biochemical and pathological features of various organs of the afflicted fetus (to be published). Confirmation of diagnoses made in utero for heterozygous and healthy fetuses was obtained by post-partum examination of glucocerebrosidase and spingomyelinase activity levels in leukocytes of the appropriate infants.


Urinary cyclic nucleotides in adult male cystic fibrosis patients. Urinary adenosine 3':5' (cyclic) monophosphate and guanosine 3':5' (cyclic)-monophosphate excretion are significantly elevated in adult male cystic fibrosis patients compared to normal men when values are expressed in ways which consider the smaller size of the cystic fibrosis subjects of the same age. Cystic fibrosis patients excreted 3.22 +/- 1.16 nmol adenosine 3':5' (cyclic)monophosphate/g creatinine per 24 h vs. 1.97 +/- 0.43 for normal men (p less than 0.02); and cystic fibrosis patients excreted 0.50 +/- 0.16 nmol guanosine 3':k' (cyclic)monophosphate/g creatinine per 24 h vs. 0.30 +/- 0.07 for normal men (p less than 0.05). Subjects were all adults who had completed linear growth and sexual development, thus eliminating any possible effects of slower maturation of cystic fibrosis patients, and all subjects were male, thus avoiding the fluctuation of urinary cyclic nucleotides with the menstrual cycle, problems which had complicated interpretation of previous studies.


Modification of lymphocyte responsiveness in vitro by lambda carrageenan compared with colloidal silica and depletion of surface adherent cells. The effects of the immunosuppressive sulphated polygalactan lambda carrageenan on in vitro models of allograft immunity were compared with the effects of removing macrophages (surface adherent and/or phagocytic cells) by established methods. Carrageenan depressed the primary mixed lymphocyte reactions, but not to the same extent as the removal of macrophages. 2-Mercaptoethanol restored the response. Secondary mixed lymphocyte reactions and responses to phytohaemaglutinin were depressed by carrageenan but not by the removal of macrophages, and in these systems 2-mercaptoethanol failed to restore the responses of carrageenan-treated cultures. In contrast, cell-mediated cytolysis by presensitized lymphocytes was not affected by carrageenan or by colloidal silica. Carrageenan depressed cell-mediated cytolysis only if it was present during the sensitization of the effector cells. We conclude that carrageenan can have two dose-related effects in vitro: one on the macrophage and one on the responding lymphocyte.


99MTc-metyhlene diphosphonate concentration in soft tissue malignant fibrous histiocytoma. Four cases of non-calcifying soft tissue malignant fibrous histiocytoma are presented which showed concentration of 99mTc-methylene diphosphonate. Angiography was performed in one of the patients and it featured hypervascularity, tumor staining and early draining veins indicative of arteriovenous shunting. As with other extraskeletal non-calcifying entities which exhibit enhanced uptake of 99mTc-phosphate complex, the mechanism of concentration is largely conjectural. Malignant fibrous histiocytoma can be added to the expanding list of conditions which may portray in avidity for 99mTc-phosphate complex.


Hexoprenaline: beta-adrenoreceptor selectivity in isolated tissues from the guinea-pig. 1. A catecholamine beta-adrenoreceptor agonist, hexoprenaline, was examined in vitro on five guinea-pig tissues and its potency relative to isoprenaline (as 100) obtained. 2. Hexoprenaline clearly delineated between those tissues classified as containing beta2-adrenoreceptors (trachea, hind limb blood vessels and uterus; relative potencies 219, 110 and 76 respectively) and those classified as containing beta1-adrenoreceptors (atria and ileum; relative potencies 3.3 and 1.0 respectively). 3. Hexoprenaline differed from some previously studied noncatecholamine beta-adrenoreceptor agonists in being only two-fold less potent, relative to isoprenaline, as a vasodilator in perfused hind limb than as a tracheal relaxant.


Spine deformities and cystic fibrosis.

Spine deformities and cystic fibrosis. Patients with cystic fibrosis have an increased risk for developing kyphosis and scoliosis. The risk for both kyphosis and scoliosis increases with age. The severity of kyphosis did not appear greater in the older age groups. Patients with retarded bone age may be more likely to have a significant spinal deformity. The presence of spine deformity does not correlate with the severity of pulmonary involvement, height, weight, serum protein and albumin in patients with cystic fibrosis.


Cutaneous manifestations of pancreatic diseases. An awareness of the cutaneous signs of diseases of the pancreas is extremely valuable. They alert the astute examiner to several life-threatening problems that result from both benign and malignant islet cell tumors, adenocarcinomas of the pancreas, and pancreatic endocrine and inflammatory diseases. Many of the cutaneous manifestations of pancreatic disease are discussed in detail, with emphasis on both the clinical presentation and pathogenesis.


Porphyria cutanea tarda. A rare cutaneous manifestation of hepatic tumors. Porphyria cutanea tarda (PCT), the most common form of porphyria, may be one of the rare cutaneous manifestations of hepatic tumors, benign, malignant, or metastatic. The liver damage associated with PCT may predispose to the development of hepatocellular carcinoma. Our experience and a review of the literature suggest that in patients with PCT in whom the usual precipitating factors are absent, or in patients with PCT of long duration and an unexplained exacerbation, liver scan is indicated to rule out the presence of a hepatic tumor.


Bactericidal action of ascorbic acid on Psuedomonas aeruginosa: alteration of cell surface as a possible mechanism. Neutralised ascorbic acid is found to exert a strong bactericidal action on Pseudomonas aeruginosa suspended in isotonic phosphate buffer at pH 7.1. Both the bactericidal and bacteriostatic action of ascorbic acid are antagonised by magnesium ions. In the absence of complex formation between magnesium and ascorbic acid it is concluded that ascorbic acid acts by competing with the magnesium binding sites in the cell wall, cell membrane or ribosomes. Using the chequer-board titration method the synergistic action of ascorbic acid and erythromycin is determined; such a potentiation of erythromycin is also adversely affected by magnesium ions. P. aeruginosa cells, washed and suspended in isotonic phosphate buffer containing ascorbic acid, became increasingly susceptible to the action of polymyxin, erythromycin, chloramphenicol, neomycin and tetracycline. It is suggested that ascorbic acid alters the cell surface to render it increasingly permeable to these antibiotics.


A hundred years of the hepatotrophic controversy. Venous blood returning from the splanchnic viscera has liver-supporting (hepatotrophic) qualities not found to the same degree in other kinds of arterial or venous blood. The effects of portal blood have been noted in animals with two livers (or a differential portal blood supply to different regions of one liver) to include hypertrophy, glycogen storage, hyperplasia, capacity for regeneration, increase of several synthetic functions, and maintenance of normal structure. The main splanchnic venous hepatotrophic factors are endogenous hormones of which the single most important is insulin. Thus, the foregoing portal hepatotrophic effects are largely eliminated with the diabetes produced by alloxan or total pancreatectomy. The injury of portacaval shunt is caused by the diversion of the hormones around the liver. Accordingly, the atrophy, injury to the organelles, and loss of the capacity for cell renewal is minimized if insulin is infused into the portally deprived liver. In these and other experiments, exogenous glucagon alone or the addition of glucagon to insulin has had no effect, but this may be because of the masking presence of gut glucagon and other hormonal or non-hormonal substances in our models. At present, the effects on the liver of exogenous insulin, glucagon, epidermal growth factor, and numerous other hormones are being determined by their intraportal infusion into eviscerated dogs in which other endogenous splanchnic factors have been eliminated.


Amino acid transport in isolated hepatocytes: effect of glucagon. Amino acid transport was studied in freshly isolated adult rat hepatocytes using non-metabolizable alpha-amino-1-[14C] isobutyric acid and 1-aminocyclopentane-1-[14C] carboxylic acid. In the presence of sodium, hepatocytes concentrated alpha-aminoisobutyric acid; this concentrative component of the transport had properties similar  to transport system A. The sodium-independent transport of aminocyclopentane carboxylic acid had properties similar to transport system L (facilitated diffusion). Glucagon stimulated the influx of alpha-aminoisobutyric acid into hepatocytes. The glucagon effect (a) occurred rapidly, but its full expression required two hours of exposure of the cells to hormone; (b) involved new protein (and possibly RNA) synthesis; and (c) occurred at low concentrations of glucagon (50% effect with 0.4 nm). Glucagon stimulated only system A. Cyclic AMP also stimulated the transport of alpha-aminoisobutyric acid. Freshly isolated hepatocytes appear conveniently suited to the investigation of various aspects of the regulation of liver amino acid transport in normal and pathophysiological states.


Portacaval shunt for glycogen storage disease and hyperlipidaemia. Complete portacaval shunt was used to treat 10 patients with glycogen storage disease. A favourable effect was noted on body growth and a number of metabolic abnormalities. More recently, continous night feedings with an intermittently placed gastric tube or through a gastrostomy has been shown to be helpful either before or after portacaval shunts. Such alimentation techniques may eliminate the need for shunts in some patients and be of adjuvant benefit in others. Portacaval shunt was also used for three children who had homozygous Type II hyperlipidaemia. Substantial reductions in serum cholesterol concentration were observed, as well as resorption of xanthomas. Reversal of some cardiovascular lesions has been documented. The benefits of portacaval shunt in these disorders is probably due to the change in the hormone climate of the liver and the whole organism brought about by diversion of the hormone-rich splanchnic venous blood around the liver.


Entamoeba histolytica and Homo sapiens.

Entamoeba histolytica and Homo sapiens. Blind acceptance of the dicta of the great has led to much confusion as to the relationship between amoeba and man. A review of the mistakes of the past may lead to a better appreciation of the present, and higher hopes for the future. An hypothesis is presented.


Effects of FSH on cyclic nucleotide accumulation in testes of rats of various ages. The accumulation of cyclic AMP in rat testis in response to FSH is much greater in immature rat compared to adult. Addition of 3-isobutyl-1-methylxanthine (MIX), a potent in vitro inhibitor of cyclic nucleotide phosphodiesterase activity, potentiates the effects of FSH but does not restore the cyclic AMP response of adult rat to that of immature rat testis. The apparent substrate affinities for cyclic AMP and cyclic GMP hydrolysis are similar in immature and mature testis. Developmental changes in cyclic AMP and cyclic GMP phosphodiesterase specific activities fail to account for the reduced responsiveness of adult testis to FSH. These results suggest a defect in synthetic rather than hydrolytic mechanisms in FSH-responsive cells.


Is cyclic AMP the regulator of hepatic ornithine decarboxylase activity? The role of cyclic AMP in the regulation of hepatic ornithine decarboxylase (ODC) activity in the rat was studied in the whole animal and in the perfused organ. Dibutyryl cyclic AMP or butyrate given to intact rats increased ODC activity; this increase was abolished by hypophysectomy 1 h prior to administering ether compound. Administration of 1 mg 1-methyl-3-isobutylxanthine (MIX) to intact rats increased ODC activity within 4 hours whereas hypophysectomy 1 h before treatment prevented this increase. No change in hepatic cyclic AMP content was seen in either intact or hypophysectomized rats following MIX. Perfusion with 0.5 mM dibutyryl cyclic AMP decreased ODC activity in isolated livers whereas perfusion with 0.5 mM 8-bromocyclic GMP produced a small increase in ODC activity. These data suggest that the effect of dibutyryl cyclic AMP in intact animals may be a property of the butyrate and that this action as well as the action of MIX may be mediated through the permissive effect of pituitary and/or adrenal hormones. The normal hepatocyte does not increase its ornithine decarboxylase activity after direct exposure to dibutyryl cyclic AMP.


Effects of thyrotropin and thyroid hormones in vivo on thyroid responsiveness to thyrotropin in vitro. The thyroid gland of rats fed propylthiouracil is known to be unresponsive in vitro to thyrotropin; to investigate further the underlying mechanism groups of rats were variously treated with propylthiouracil and thyroid hormone or subjected to hypophysectomy. In vitro responsiveness of the thyroids was tested by measuring an increase in the concentration of c AMP when thyrotropin or prostaglandin E1 was added to the medium. Results showed that responsiveness to thyrotropin partially returned with rats fed prophylthiouracil and hypophysectomized 5, but not 2, days before death; hypophysectomy of normal rats led to increased in vitro responsiveness to thyrotropin and this was partially reversed by injections of thyrotropin for a week before death. Administration of thyroid hormone had little effect in these investigations and in vitro responsiveness to prostaglanding E1 was not consistently influenced by any of the in vivo regimens. From this experience we conclude that, at least as studied in vitro, circulating thyrotropin has a significant role in modulating responsiveness of the thyroid to thyrotropin.


Role of cyclic nucleotides in modulating ovarian hCG action. The role of cyclic nucleotides in mediating hormonally responsive adenylate cyclase and cAMP-dependent protein kinase was examined in vivo and in vitro when pseudopregnant rats were injected with hCG. Intracellular ovarian levels of cAMP increased, as expected, but no change in cGMP concentrations was observed. However, both cGMP and cAMP activated ovarian CDPK holoenzyme in vitro but cGMP had a lower affinity. The subunits of hCG were without effect. Even though cGMP and cAMP dissociate partially purified ovarian CDPK holoenzyme in vitro, the receptor sites of the regulatory subunit of CDPK would appear to be relatively specific for cAMP. Moreover, cGMP probably does not mediate hCG action in vivo.


Study of follitropin receptors in testis using a homologous system. Binding of porcine follitropin to plasma membranes from immature porcine testis and correlation with adenylate cyclase stimulation. The properties of follitropin receptors in immature porcine testis were determined using highly purified porcine follitropin. 1. The characteristics of follitropin binding to a subcellular fraction rich in plasma membranes were studied using a 125I-labelled follitropin with high specific activity (75-100 Ci/g) and high binding activity. The binding is dependent on time, temperature and pH. It is specific to follitropin as demonstrated by the very low binding activity of the follitropin alpha and beta subunits and of the other glycoprotein hormones. Scatchard analysis of binding data indicated an equilibrium association constant of 2 x 10(10) M-1 and a concentration of high affinity binding sites of 500 fmol/mg membrane proteins. 2. A sensitive radio-ligand receptor assay was developed. Fifty percent inhibition of binding was obtained with as little as 2 ng of porcine follitropin. Ovine and bovine follitropins and pregnant mare serum gonadotropin gave binding inhibition curves parallel to that given by porcine follitropin. With equine and human follitropin, significantly different slopes were recorded. 3. Kinetics of dissociation of labelled follitropin from its testis receptors showed the presence of at least two compartments with fast and slow dissociation rate constants. The ratio between the sizes of the slow and fast compartments appeared dependent upon preincubation time. 4. A temporal correlation was observed between binding of follitropin to testis receptors and activation of membrane bound adenylate cyclase.


Calcium as modulator of the hormonal-receptors-biological-response coupling system. Effects of Ca2+ ions on the insulin activated 2-deoxyglucose transport in rat fat cells. Activation of 2-deoxyglucose transport in isolated rat fat cells by insulin is dependent upon the presence of Ca2+ in the external medium. When calcium concentration is kept below 100 micron, insulin acts like a partial agonist, giving only half of the maximal activation obtained normally with a millimolar concentration of this ion. Oxytocin, whose insulin-like action on adipocytes activates glucose oxidation by these cells, was found to be unable to affect the rate of 2-deoxyglucose transport. This, together with previous observations, suggests that calcium ions play a role in the mechanism of insulin action possibly by binding selectively to membrane sites involved in the transmission of the hormonal message to the glucose carrier. Oxytocin seems to trigger only intracellular glucose metabolism and it appears that there is an absolute requirement for calcium ions in the activation of a still unknown membrane signal.


Cyclic AMP-binding proteins: inverse relationship with estrogen-receptors in hormone-dependent mammary tumor regression. Dimethylbenzanthracene-induced rat carcinomas possess activities binding cyclic adenosine 3':5'-monophosphate (cAMP) and estrogen. When dimethylbenzanthracene-induced tumors regress after ovariectomy of the host, a change in the specific binding of cAMP and estrogen occurs in the tumors. Six days after ovariectomy, cAMP binding increases 5-fold in the nuclei and 2-fold in the cytosol of tumors, while nuclear and cytoplasmic estrogen binding decreases by 80% and 50%, respectively. These changes in activities binding cAMP and estrogen are detectable within 1 day after ovariectomy and the changes are reversed when resumption of tumor growth is induced by the injection of 17beta-estradiol. When dimethylbenzanthracene-induced tumors fail to regress after ovariectomy, the change in activities binding cAMP and estrogen does not occur. Significant increases in the cAMP level as well as in adenylate cyclase and cAMP-phosphodiesterase activities are also found in the regressing tumors. Concomitant with the increase of cAMP-binding activity is an increase in histone kinase activity in the regressing tumor. These data suggest the involvement of cAMP in the growth control of a hormone-dependent mammary rumor.


Effects of steroid hormones on the level of corticotropin messenger RNA activity in cultured mouse-pituitary-tumor cells. Studies have been made with the mouse pituitary tumor cell line AtT-20 in culture to determine whether or not the suppression of pituitary corticotropin messenger RNA activity observed upon the administration of glucocorticoids to adrenalectomized rats is due to a direct action of these steroid hormones on the pituitary. The levels of corticotropin messenger RNA activity in AtT-20 cells treated with various steroid hormones were measured with the use of the cell-free protein-synthesizing system derived from wheat germ. The addition of dexamethasone to culture medium reduced the level of corticotropin messenger RNA activity to 30-40% of that in untreated cells. Corticosterone and cortisol exhibited a suppressive effect to a lesser extent. In contrast, nonglucocorticoids such as testosterone and 17beta-estradiol were essentially ineffective. These results indicate that at least part of the glucocorticoid action is exerted directly on the pituitary to suppress corticotropin messenger RNA activity.


Nucleotide sequence of the restriction fragment Hind-F-EcoRI1 of simian-virus-40 DNA (part of the VP1 gene). The nucleotide sequence of the simian virus 40 (SV40) genome region between the cleavage sites for restriction endonucleases EcoRI (map position 0) and HindII (map position 0.05) has been determined mainly by the partial chemical DNA degradation procedure of Maxam and Gilbert. This fragment represents 5.3% of the genome of SV40 and is located in the late region, internally in the VP1 gene. The message strand shows only one open reading frame for translation into protein, which connects to the one for the preceding fragment. On this basis part of the amino acid sequence of the VP1 protein is presented.


Complete nucleotide sequence of the simian-virus 40 Hind-G fragment and localisation of the carboxyl terminus of the VP1 protein. The restriction fragment Hind-G represents 7.0% of the simian virus 40 (SV40) genome. The information present in fragment Hind-G is expressed as part of the major, late 16-S messenger RNA. The complete nucleotide sequence of the fragment Hind-G has now been determined by application of the procedure of Maxam and Gilbert [Proc. Natl Acad. Sci. U.S.A. (1977) 74, 560-564]. It contains 369 nucleotide base pairs. On the basis of the termination code words in the strand with the same polarity as the late mRNA, two illegitimate reading frames can be defined. Therefore the third, open frame must code for the carboxyl terminal part of the VP1 protein. It terminates within fragment Hind-G with a TGA signal. This stop codon is followed by a non-translated region of the mRNA of about 83 nucleotides. The latter contains the sequence A-A-U-A-A-A, common to all other eukaryotic mRNA molecules so far studied. The Hind-G fragment also contains sequences which presumably play a role in the synthesis, processing and/or expression of early mRNA; these aspects are discussed in the following paper.


Cytochrome c from Schizosaccharomyces pombe. 1. Purification, spectral properties, and amino-acid composition. Cytochrome c from the fission yeast Schizosaccharomyces pombe has been purified. Its chromatographic and spectral properties are reported and compared to those of iso-1-cytochrome c from baker's yeast; the amino-acid composition is described. Schiz. pombe cytochrome c has a much lower affinity for Amberlite IRP64 than Sacch. cerevisiae iso-1-cytochrome c. Its alpha absorption band splits into three maxima (calpha1, calpha2, and calpha3) at -190 degrees C; this is unusual in yeasts, as shown by the low-temperature whole-cell absorption spectra which were examined in various yeast genera, species, and strains. A minor component can be separated by Amberlite chromatography. It exhibits the same low-temperature splitting of the alpha absorption band as the main fraction and it has a similar amino-acid composition with a notable exception: it is an unmethylated form of the cytochrome.


Cytochrome c from Schizosaccharomyces pombe. 2. Amino-acid sequence. The amino acid sequence of Schizosaccharomyces pombe cytochrome c has been established by automatic degradation of the protein and by manual degradation of fragments obtained by cyanogen bromide cleavage and chymotryptic digestion. The chymotryptic peptides were aligned by homology with other known cytochrome c sequences. The protein is 108 residues long, with a four-residue amino-terminal tail. It has only one methionine residue and differs from other fungal cytochromes c in lacking the one-residue deletion at the C-terminal end. After a cyanogen bromide step, an unexpected cleavage of the peptide chain before a cysteine residue was observed. This is ascribed to formation of a dehydroalanyl residue during an incomplete S-carboxymethylation of the apoprotein, and subsequent cleavage under acidic conditions. Experimental evidence is presented in favour of the proposed mechanisms.


Covalent binding of an NAD analogue to liver alcohol dehydrogenase resulting in an enzyme-coenzyme complex not requiring exogenous coenzyme for activity. 1. The NAD analogue, N6-[N-(6-aminohexyl)carbamoylmethyl]-NAD, was covalently bound to horse liver alcohol dehydrogenase in a carbodiimide-mediated reaction and in such a way that it was active with the very same enzyme molecule to which it was coupled. 2. The degree of substitution, i.e. the number of NAD analogues per enzyme subunit, could be varied (0.3-1.6). In one preparation 1.6 coenzyme molecules were bound per subunit; the alcohol dehydrogenase activity of this preparation was 40% of the activity obtained after addition of free NAD in excess. 3. It was calculated that every fourth active site of this preparation was provided with a covalently bound functioning coenzyme analogue, and that this analogue had a cycling rate of about 40 000 cycles/h in a coupled substrate assay. 4. The presence of the covalently bound coenzyme made the active sites difficult to inhibit with a competitive inhibitor. For example, 10 mM AMP inhibited the activity of the preparation by 50% whereas a reference system containing native alcohol dehydrogenase was inhibited by 80% in spite of the fact that the reference system contained about 20 000 times as high a concentration of coenzyme.


Binding of microtubule proteins to DNA: specificity of the interaction. Tubulin is detected among the DNA-binding proteins when an extract from fibroblasts is chromatographed on DNA-cellulose. Further purification of the colchicine-binding activity shows that purified tubulin from fibroblasts does not bind to DNA. Depolymerized brain microtubule proteins show a high affinity for DNA. The fraction bound is composed of tubulin and microtubule-associated proteins. Experiments with fractionated microtubule proteins indicate that tubulin-free microtubule associated proteins bind to DNA, while tubulin free of microtubule-associated proteins does not. Microtubule-associated proteins bind better to eukaryotic than to phage DNA suggesting a specificity of the interaction.


Localization of the oxytocin receptor in the plasma membrane of rat myometrium. The distribution of [3H]oxytocin binding sites among various subcellular fractions of rat myometrium paralleled the distribution of 5'-nucleotidase, a plasma membrane marker enzyme, but not of NADPH-cytochrome c reductase or succinate-cytochrome c reductase, which are endoplasmic reticulum and mitochondrial marker enzymes respectively. [3H]Oxytocin binding to the most enriched plasma membrane fraction showed the degree of selectivity with respect to hormone analogues that is expected for the oxytocin receptor. The binding of oxytocin to this fraction showed an apparent Kd of 1.98 X 10(-9) M and a capacity of 1.28 pmol mg-1. It is concluded that the oxytocin receptor is located on the plasma membrane of the smooth muscle cells of the rat uterus.


Neurological complications in patients with malignant tumors of the nasopharynx. Of 150 new cases of nasopharyngeal carcinoma diagnosed in Israel during a 9-year period (nationwide study 1960--1968), 74 patients developed neurological complications. In 92% of the cases, neurologic deficits were confined exclusively to cranial nerves. The majority of these patients presented general symptoms of disease such as neck masses, head and facial pain, or nasal and aural disorders. In 23 patients (34%), the initial presentation was of neurologic disability. The most frequently affected nerves were the abducens and the trigeminal. In the fully developed clinical picture, ocular and trigeminal lesions predominated. 5-year survival in patients with cranial nerve involvement was 21% as compared to 55% in those without such lesions. Survival was not influenced by delayed diagnosis.


Role of B cells in the expression of genetic resistance to growth of Rous sarcoma in the chicken. Resistance to the development of progressively growing tumors induced by Rous sarcoma virus is a dominant trait controlled by a gene linked to the major histocompatibility complex (MHC). The effect of bursectomy (Bx) on the expression of this trait was studied in two inbred lines of chickens homozygous for different MHC alleles, and which differ with respect to the gene controlling resistance to Rous tumors. The results show that Bx alters the expression of the trait, since genetically resistant birds were rendered highly susceptible to progressive tumor growth. The bursa of Fabricius thus makes an important contribution to resistance. The results do not indicate whether genetic resistance is mediated exclusively by B cells or by another bursa-dependent population.


Conditions for maximal synthesis of cyclic AMP by mouse macrophages in response to beta-adrenergic stimulation. The synthesis of cyclic AMP by mouse peritoneal macrophages in response to stimulation by isoproterenol was studied as a function of drug concentration, incubation time and cell density. Cyclic AMP levels of macrophages increased 3 to 3.5 times over the control level 20 sec after the addition of 10(-3) M isoproterenol. Under these conditions the dose response could be followed down to an isoproterenol concentration of 10(-6) to 10(-7) M. When cell suspensions were inactivated as early as 1 sec after the addition of the drug, the increase in cyclic AMP was much greater (153 vs. 25 pmol/10(7) cells). Macrophage suspensions of high cell density were less responsive than those of low cell density. In the absence of any inhibitor of phosphodiesterase, the stimulatory effect of isoproterenol was always of short duration. The maximum effect of beta-adrenergic stimulation probably occurs in less than 1 sec at a cell density less than 2 x 10(6) cells/ml. The beta-blocking drug Visken abolished the observed effects.


Shedding of anti-IgM from antibody-coated human lymphoma lines: differences between Epstein-Barr virus-negative lines and their virus-converted sublines. In vitro converted, Epstein-Barr (EBV) genome-carrying cell lines showed a reduced ability to shed surface-bound antibodies, compared to their EBV-free parental B lymphoma lines. On the other hand, antibody degradation was higher with EBV-positive cells. Analysis of antibody-coated single cells revealed that cells which failed to redistribute or cap their ligand-bound surface components at 37 degrees C, were also capable of shedding bound antibody. This suggests that capping and shedding are essentially independent phenomena, although both may be influenced by the same virally induced change in the lateral mobility of membrane constituents.


The protective effect of phentolamine against cardiac arrhythmias in the rat. Norepinephrine was given by continuous infusion at a rate of 80 microgram/kg/min for 2 min. Norepinephrine caused the appearance of cardiac arrhythmias, primarily ventricular extrasystoles. The prior administration of phentolamine, even in a dose which did not antagonize the pressor effect of norephinephrine, prevented extrasystole production by norepinephrine. Tolazoline and yohimbine, in doses which did not affect the vasopressor action of norepinephrine, also suppressed extrasystole production. It is concluded that the antiarrhythmic effect of phentolamine, does not require antagonism of alpha-adrenoceptors of the type found in the vasculature, but may involve effects on a different type of alpha-adrenoceptors in the heart.


The plasma cyclic AMP response to catecholamines as potentiated by phentolamine in rats. Norepinephrine failed to increase plasma cyclic AMP when injected alone into fasted rats, in contrast with sharp increases elicited by isoproterenol, epinephrine or tyramine. In rats pretreated with 6-hydroxydopamine or cocain, however, there was significant increase in plasma cyclic AMP after norepinephrine injection, suggesting that the rapid neuronal catecholamine uptake was at least partly responsible for the lack of norepinephrine action. Phentolamine was very effective in enhancing the epinephrine-, norepinephrine- or tyramine-induced increase in plasma cyclic AMP but without effect on the isoproterenol-induced increase. Blockade of postsynaptic alpha-adrenoceptors, rather than of presynaptic receptors, is likely to be involved in the phentolamine potentiation, since it was even observed in rats treated with 6-hydroxydopamine or cocaine. A discussion is presented regarding the mechanism by which cyclic AMP generation is influenced by the alpha- and beta-adrenoceptor interaction on effector cell membranes.


Properties and connections of cat fastigiospinal neurons. 1. Neurons in the cat fastigial nucleus that project to the upper cervical spinal segments (fastigiospinal neurons) were fired by antidromic stimulation of the contralateral spinal cord. Dye ejection from the recording electrode was used to show that most neurons were in the rostral half of the fastigial nucleus. 2. Fastigiospinal neurons can be excited and/or inhibited by stimulation of forelimb and hindlimb nerves and by stimulation of the vestibular nerve. These inputs converge on many neurons. 3. Antidromic microstimulation was used to trace fastigiospinal axons to the vicinity of motor nuclei in in C2-C3. 4. The rostral fastigial nucleus was stimulated in preparations with the medial longitudinal fasciculus transected by a wide lesion that impinged on the medial reticular formation in the caudal medulla, to eliminate some potential axon reflexes. Short-latency EPSPs were recorded in some trapezius and biventer-cervicis motoneurons. In many cases there was little or no occlusion between these EPSPs and others evoked by stimulation of the vestibular nerve ipsilateral to the motoneurons. 5. Movement of the stimulating electrode and placement of this electrode lateral to the fastigial nucleus show that the zone from which low threshold EPSPs can be evoked is localized. 6. Latency measurements and lack of temporal facilitation with double shocks suggest that the EPSPs are monosynaptic. The evidence suggests that they are caused by fastigiospinal fibers terminating on motoneurons.


Changes in latency and duration of neural responding following developmental auditory deprivation. The initial latency of spikes evoked by click stimulation and the duration over which spiking occurred were observed in the inferior colliculi of rats. One ear of these animals had been deprived of early auditory stimulation by ligation of the external meatus. Clicks presented to the normally experienced ears evoked spikes in the opposite colliculus with latencies that depended on the characteristic frequency of the unit. Low-frequency (less than 5 kHz) units had latencies from 6-10 msec. Latencies declined to 3-4 msec for high frequency (greater than 20 kHz) units. After an ear had been deprived of sound from 10 days after birth, response latencies of units in the opposite colliculus with characteristic frequencies below about 10 kHz were comparable to controls, but most units above 10 kHz had latencies 2-3 times control latencies. Spike activity evoked in these units did not continue as long as that for most comparable control units. Ears sound deprived for an equal period from 60 days after birth also had changes in latencies and response durations, but these were much less than in the developmentally deprived. Latencies of gross potentials at the auditory nerve were not affected by early deprivation, indicating a central origin for the latency changes.


Retinal afferents form Gray-type-I and type-II synapses in the suprachiasmatic nucleus (rat). The synapses of optic nerve afferents in the suprachiasmatic nucleus (SCN) usually form Gray type I (asymmetrical) synapses, but about 13% show clear-cut Gray type II ( symmetrical) active zones. Some presynaptic elements form a Gray type I--active zone with one dendrite and a Gray type II-active zone with another postsynaptic element at the same time. It is discussed whether this variabilility is related to a simultaneous excitatory and inhibitory action, to a variable activity or efficiency of the synapses or to various stages of maturation.


Evidence for the nonhydrophobic interaction of aromatic, nitrogen-containing compounds with the coenzyme binding site of a NAD-linked D-lactate dehydrogenase. Quantitative structure activity relationships suggest that the binding of quinoline and phenanthroline analogs to D-lactate dehydrogenase from the barnacle, Balanus nubilus Darwin, does not involve primarily hydrophobic effects. This phenomenon appears to exist also for other lactate dehydrogenases.


Chlorpromazine causes vesicle population changes in the monoaminergic synapse of the rat caudate nucleus. The population of monoaminergic synaptic vesicles in the rat caudate nucleus remained unchanged or slightly decreased 3 h after chlorpromazine (CP) administration, and clearly increased after 24 h. The diameter of synaptic vesicles became smaller when the vesicles increased. These findings suggest that CP causes presynaptic blocking in part of its actions and leads to a condition in which neural transmission is inactive. In the control animals, population of the vesicles tended to fluctuate following the circadian rhythm.


cAMP in spermatozoa taken from different segments of rat epididymis. Experimental evidence conclusively indicates that the epididymis is under endocrine control and plays an active role in the process of spermatic maturation.


Adenylate kinase from Rhodospirillum rubrum. A partial purification and some properties of adenylate kinase from the photosynthetic bacterium Rhodospirillum rubrum are described.


Chemical synthesis of a hexadecapeptide segment of ubiquitin that activates adenylate cyclase and induces lymphocytes to differentiate. A hexadecapeptide corresponding to positions 59--74 of ubiquitin was synthesized and purified. The peptide was characterized by its mobility in TLC and electrophoresis, amino acid sequence and composition, and molar rotation. The peptide possessed approximately 40% activity compared with native ubiquitin in each of 3 biological assays in vitro: a) thymocyte induction, b) B cell induction and c) elevation of intracellular cyclic AMP levels in sarcoma 180 cells.


Inhibition of liver fructose 1,6-bisphosphatase activity by Zn2+: reversal by imidazole pyruvate. Imidazole pyruvate was found to be a very potent natural chelating agent in reversing the inhibition of liver fructose 1,6-bisphosphatase activity by Zn2+. This metabolite may play a physiological role in gluconeogenesis.


A promoting action of cyclic GMP on contractions of guinea-pig vas deferens. The effect of dbc-GMP has been studied in ductus deferens of the guinea-pig. The nucleotide potentiated the contractions induced by electrical field stimulation and by adrenergic agonists. The site of action was probably in the smooth muscle cell, since the release of excitatory transmittor was not influenced.


Phosphoinositide content in the erythrocyte membrane of rats with spontaneous and renal hypertension. The increase of the content of triphosphoinositide in the erythrocyte membrane in rats with spontaneous and renal hypertension and decrease of phosphatidylinositol at spontaneous hypertension were revealed.


Criteria for the appearance of post-tetanic potentiation of transmission at central synapses in Helix aspersa. Long-lasting potentiation of inhibitory post-synaptic potentials occurs at 2 identifiable synapses in Helix brain. It appears only after tetanic stimulation and after a minimum of 20 impulses. Its amplitude and duration depends on the number of stimuli.


Behavioural effects of naloxone in rats. Naloxone in rats induces a behavioural syndrome closely resembling that induced by intraliquorally injected ACTH peptides. This effect is probably due to a displacement of the ACTH peptides from other receptors (e.g. opiate receptors).


Hepatoma induction in the rat by the subcutaneous administration of powdered 3'-methyl-p-dimethylaminoazobenzene. A relatively safe and simple procedure was developed for the induction of hepatomas in the rat by the s.c. administration of powdered 3'-methyl-p-dimethylaminoazobenzene.


Effects of chronic treatment with ACTH on the intracellular levels of cyclic-AMP and cyclic-GMP in the rat adrenal cortex. The effects of chronic ACTH treatment on the increase in the intracellular concentration of cyclic-AMP and cyclic-GMP acutely elicited by ACTH in the rat adrenal cortex were investigated. The results are consistent with the hypothesis that chronic ACTH treatment stimulates a) the de novo synthesis of adenylate- and guanylate-cyclase or b) the synthesis of new specific membrane receptors for ACTH.


[Effect of cyclic adenosine monophosphate and guanosine monophosphate on the aggregation and nucleotide metabolism of the blood platelets]. Cyclic adenosine- and guanidine-monophosphates (c-AMP and c-GMP) in final concentration of 1.5 mM were found to bring down the aggregation capacity of the rabbit's blood platelets, this being attended by accumulation of AMP. The content of nucleoside triphosphates and nucleoside-diphosphates of the adenyl series in thrombocytes was influenced by the cyclic mononucleotides in different ways, viz. c-AMP increased the level of ATP and forced down that of ADP, while c-GMP, on the contrary, reduced an ATP-concentration and raised the ADP level.


[Change in the electron paramagnetic resonance signal at g 2.0057 in the tissues of white mice with nitrite hypoxia]. The EPR signal intensity at g 2.0057 was measured in tissues of albino mice subjected to the action of sodium nitrite. An increased signal in the blood and a decreased one in the liver and spleen were registered, this being accounted for by redistribution of ascorbic acid in the organism due to the action of nitrite.


Threonyl-tRNA synthetase from yeast: aminoacylation of tRNA on its non-accepting 3'-terminal hydroxyl group and its behaviour in enzyme-catalyzed deacylation. Methods have been developed by which tRNA Thr may be aminoacylated at the normally non-accepting 3'-terminal ribose OH. Two of the methods utilize the mischarging ability of the synthetases under special conditions of low salt concentration and presence of organic solvents. The third method demonstrates for the first time that for some synthetases the 2',3' specificity may be manipulated by use of similar special conditions. In the case of threonyl-tRNA synthetase, Thr-tRNAThr-C-C-A(3'd) has been synthesised by this method. The behaviour of threonyl esters of tRNAThr-C-C-A, tRNAThr-C-C-A(2'd) and tRNA Thr-C-C-A-(3'd) in the free enzyme-catalyzed deacylation has been studied and the results indicate that the cis diol functional group is necessary for this hydrolysis. The position on the terminal ribose from which the amino acid is removed in this reaction remains to be identified.


Prognosis in primary amenorrhea.

Prognosis in primary amenorrhea. A retrospective review of 62 patients with primary amenorrhea indicates that thoughtful clinical evaluation combined with dynamic hypothalamic-pituitary testing can usually determine the etiology and prognosis. A careful history, consideration of chronologic age/bone age/height relationships, and assay of serum gonadotropins distinguished all patients with medical diseases, ovarian failure, hypogonadotropic hypogonadism, and polycystic ovaries. Luteinizing hormone-releasing hormone (LH-RH) stimulation, sometimes combined with clomiphene therapy and estrogen provocation tests, assisted with prognostic and pathophysiologic evaluation, although patient management rarely changed. An age-inappropriate LH-RH test result was helpful in identifying patients with abnormal maturational patterns.


Hormonal control of mRNA synthesis studied by nucleic acid hybridization. The regulation of protein synthesis by steroids is thought to be due to hormonal effects primarily on mRNA concentration. Experimental evidence to support this conclusion has come largely from the use of DNA probes complementary (cDNA) to mRNA molecules or by translation of the mRNA in vitro. In this review the experimental procedures involved and the application to hormone action of cDNA hybridization will be reviewed. (1) mRNA concentrations can be assayed in tissue RNA samples by hybridization with radiolabelled complementary DNA probes (cDNA). From the rate of hybridization of an mRNA preparation to a cDNA probe it is possible to estimate specific mRNA concentrations and thereby study their hormonal regulation within tissues of subcellular fractions (2) Rates of synthesis of a specific RNA can be measured by hybridization of pulse-labelled RNA with excess cold cDNA as illustrated in studies of the glucocorticoid induction of MMTV RNA. (3) Hormore-induced alterations of mRNA populations as a whole can be investigated. From the kinetics of hybridization of mRNA with its complementary DNA it is possible to estimate the number of different RNA sequences in tissues and to approximate the number of copies of each sequence per cell. Consequently, by comparing mRNA samples isolated from tissues of different hormonal status it is possible to demonstrate specific hormone-inducible mRNA species and, in some cases, identify their translation products.


The effect of epinephrine and dibutyryl cyclic AMP on glucose 1,6-bisphosphate levels and the activities of hexokinase, phosphofructokinase and phosphoglucomutase in the isolated rat diaphragm. Based on previous studies which have revealed that glucose 1,6-bisphosphate (Glc-1,6-P2) is a potent inhibitor of muscle hexokinase and an activator (deinhibitor) of phosphofructokinase and phosphoglucomutase, the effect of epinephrine on the levels of this regulator in rat diaphragm muscle was investigated. It was found that epinephrine caused an increase in diaphragm Glc-1,6-P2 levels, accompanied by a reduction in the activity of hexokinase and an activation (deinhibition) of phosphofructokinase and phosphoglucomutase. N6-2'-O-dibutyryl cyclic AMP was able to mimic all these effects of epinephrine. The concentration of glucose-6-phosphate was not changed by epinephrine, under conditions in which the hormone produced an increase in cyclic AMP and Glc-1,6-P2 levels and the concomitant decrease in hexokinase activity. It was also shown that Glc-1,6-P, in the concentration range found after epinephrine, inhibited the diaphragm hexokinase and deinhibited phosphoglucomutase. These results may suggest a mechanism of epinephrine action by which the activities of hexokinase, phosphoglucomutase and phosphofructokinase, through the action of Glc-1,6-P2, are synchronized with the cyclic AMP-mediated activation of glycogen phosphorylase, to achieve an increase in total glycogenolysis and glycolysis and a concomitant reduction in glucose utilization by the muscle.


Dissociation of specific binding of 25-OH-D3 and resorption in fetal rat bones. Specific binding of 25-OH-D 3 was measured in cytosol prepared from isolated fetal rat bone cells. Binding was significant after 2 h incubation at 0 degrees C and appeared to be approaching a plateau at 4 h. Binding was half-maximal at 1.7 X 10(-10) M 25-OH-D3. 24(R),25-(OH)2D3, which was approximately equipotent with 25-OH-D3 in bone culture, had approximately the same binding activity. 1,25-(OH)2D3, which was 2--3 orders of magnitude more active on resorption, was a much weaker competitor for binding. Vitamin D3, which was inactive in culture, was at least as effective a competitor as 1,25-(OH)2D3. The results suggest that the cytosol site which specifically bind 25-OH-D3 is not the mediator of the bone-resorbing activity.


Regulation of cholesterol metabolism in rat adrenal mitochondria. Addition of cholesterol to rat adrenal mitochondria resulted in a stimulation of pregnenolone synthesis. The slow step of the mitochondrial cholesterol side-chain cleavage reaction could be the interaction of the sterol with cytochrome P-450. The rate of cholesterol binding to this enzyme as observed spectroscopically correlated with the equilibration period (20 min) of the mitochondria and exogenous cholesterol required for maximal rates of pregnenolone synthesis. It is suggested that translocation of cholesterol between different sterol pools occurs within the mitochondria. Potential intracellular effectors that could be of importance in the movement or regulation of mitochondrial cholesterol include bivalent metallic ions, prostaglandins, cyclic nucleotides, polyamines and polylysine. Of the effectors studied, only calcium ions and polylysine markedly stimulated pregnenolone synthesis. These effectors might stimulate steroidogenesis by lateral displacement of cholesterol in the mitochondrial membrane into a compartment easily accessible to the cholesterol side-chain cleavage enzyme complex.


Synthesis and secretion of transferrin by cultured mouse hepatoma cells. The mouse hepatoma cell (Hepa-1) in tissue culture has been shown to synthesize and secrete three electrophoretically distinct transferrins. Each of these forms of transferrin has a molecular weight of 77,000, as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The concentration of each form is indicated by its staining intensity, which is highest in the form with the fastest mobility and lowest in the form with the slowest mobility. The relative rate of transferrin synthesis has been determined in log-phase and stationary-phase cells; the data indicate that the relative rate of synthesis increases twofold in stationary-phase cells. When the incorporation of [3H]leucine into transferrin reaches steady state, the rate of secretion is equal to the rate of synthesis; the rate of secretion also increases twofold in stationary-phase cells. Our studies also show that transferrin synthesis accounts for 0.98% of the total protein synthesis in log-phase cells and for 1.8% in stationary-phase cells. This is the level of synthesis that has been determined by in vivo studies. We conclude that after continuous culture for several years these hepatoma cells have maintained one of the characteristics of the differentiated liver cell, namely, the ability to synthesize and secrete transferrin.


Changes in the cyclic AMP content during growth and development of Acetabularia. The 3',5'-adenosine monophosphate (cyclic-AMP) content of the unicellular alga Acetabularia has been examined at various developmental stages. It has been found that very young algae, less than 10mm in length, have a high cAMP content [more than 7 pmoles per 100 mg wet weight (WW)], but that with the growth of the algae, the cAMP content decreases rapidly, reaching the low level of 0.5--1.0 pmoles per 100mg WW. The cAMP content remains at this level until cap differentiation, after which an increase in cAMP content accompanies cap enlargement. It has been shown that these results are unlikely to be affected by changes in the cAMP content induced by variations in circadian rhythm. Treatment with theophylline (2.10(-3) M), a phosphodieterase inhibitor, results in an increase in the cAMP content and delays growth and cap formation. Experiments on the effects of theophylline upon the circadian rhythm of oxygen evolution have shown that the continuous presence of theophylline in the culture medium does not induce a phase shift in the rhythm. The cAMP content of anucleate Acetabularia shows development stage variations parallel to that of the whole algae.


Concanavalin-mediated attachment to membranes of a cellular slime mould cyclic AMP phosphodiesterase. In the cellular slime mould Dictyostelium, a membrane-bound cyclic AMP phosphodiesterase undergoes a tenfold increase in activity when amoebae reach the aggregation stage of development. Our previous studies had shown that when non-aggregating cells, which produce extracellular and intracellular forms of the enzyme, are treated with the lectin Concanavalin A (Con A), they exhibit prematurely high levels of the membrane bound enzyme. The present results indicate that this effect may be largely due not to the induction of the enzyme by Con A but rather to the binding of the intracellular form of the enzyme to membranes by Con A. This conclusion is based on the findings that: a) the enzyme activity associated with membranes from Con A treated cells can be decreased by treatment with the haptenic sugar alpha-methyl mannoside: b) mambranes from untreated cells having only low membrane-bound phosphodiesterase activity can acquire increased activity after incubation with Con A and intracellular phosphodiesterase; c) the intracellular phosphodiesterase binds to Sepharose-Con A and is eluted with alpha-methyl mannoside. These results raise the possibility that some of the effects attributed to Con A in the literature may not be due directly to Con A but to glycoproteins attached to membranes by Con A.


Method for the preparation of active maturation promoting factor (MPF) from in vitro matured oocytes of Xenopus laevis. A method for the large scale extraction of Maturation Promoting Factor (MPF) from in vitro matured oocytes of Xenopus laevis is described. MPF has been previously described only as a component(s) of hormone-matured cytoplasm within amphibian oocytes (or eggs) which is able to induce the reinitiation of the meiotic process from late diplotene stage until second metaphase arrest, when microinjected into diplotene arrested (fully grown) recipient oocytes. Standard biochemical methods for the extraction and purification of this factor(s) haven been unsuccessful due to its extreme instability and sensitivity to dilution. The procedure is dependent upon the inclusion of sodium fluoride (NaF) in the extraction medium with its effect presumably due to its ability to inhibit phosphorprotein phosphatases. The successful preservation of MPF activity described in this report permits further attempts to be made to isolate and characterize this, to date, elusive cytoplasmic factor, which plays a key role in the complex cellular processes involved in the hormone-dependent differentiation of an oocyte into an egg.


Differential enzyme distribution in lobules of livers from young and old mice and rats. In the livers from young (3-6 month) and old (30 month) C57/BL mice and BN/Bi rats light microscope histochemistry has shown that enzyme activity is not always distributed evenly throughout the lobule. The mitochondrial enzyme succinic dehydrogenase, the plasma membrane enzyme 5'-nucleotidase and the endoplasmic reticulum enzyme glucose-6-phosphatase showed heavier reaction product in the perioportal regions of the lobule compared with the centrilobular regions. Alkaline phosphatase showed an altered distribution pattern with age: in young livers this was uniform throughout the lobule while in old livers there was enhanced peripoertal activity. Electron microscope cytochemistry showed that this was due to increased numbers of bile canaliculi in this region containing reaction product and to the additional presence of reaction product associated with the microvilli lining the space of Disse.


[Biochemical, enzymatic and cultural characteristics and criteria of pathogenicity of staphylocci (study of strains isolated in a hospital environment)]. The Authors have examined the coagulase activity, mannitol fermentation, DNase and phosphatase activity, and production of haemolisins and pigment on 200 strains of Staphylococcus isolated from hospitalized patients affected by various diseases. On the basis of results obtained, they conclude that the evaluation of the pathogenic power of Stah. aureus should be always founded upon a "pattern" of biochemical, enzymatic, cultural and toxinogenetic tests.


Activity of some mitochondrial enzymes in the progeny of rabbits treated with dichlorvos in the gestation period. The activities of cytochrome oxidase (CYO) and succinate dehydrogenase (SDH) in brains of progeny of rabbits treated with dichlorvos (DDVP) 6 mg/kg/day during last ten days of pregnancy were investigated. Biochemical estimation of mitochondrial fraction of the brain tissue and the histochemical studies of fresh cryostat slices were carried out in 1, 8 and 16 day old rabbits. In comparison with control animals the decrease in CYO and SDH activity and the disturbances in "enzymatic maturation" rythm were observed in progeny of rabbits submitted to treatment with DDVP. In neuropil the changes were more pronounced than in pericarium of the nerve cells. In the brain structures which are sensitive to the metabolic disturbances (Ammon horn) SDH activities decreased.


[Possible roles of prostaglandins in the hypothalamus (author's transl)]. The last decade has been the most prolific and stimulating period in the area of prostaglandin (PG) study. Since PGs were found in the hypothalamus and cerebrospinal fluid, and were released from the central nervous system (CNS) spontaneously and in response to chemical or electric stimulation, many investigators have been engaged in studying their effects in the CNS. In fact, PGs have a wide range of pharmacological actions in the CNS. Relatively large doses of PGs have to be given centrally to produce some effects. On the other hand, some types of PGs, when applied centrally in doses of a few ng, stimulate the hypothalamus or the pituitary gland to increase secretion of hypothalamic and anterior and also posterior pituitary hormones. Physiological investigations of PGs have been aided by the use of inhibitors of their synthesis; aspirin, indomethacin etc. These compounds inhibit secretion of the hormones from the hypothalamus as well as the pituitary, suggesting that endogenous PGs exert a functional role for the hormone secretion. To produce fever, PGEs have to act on the preoptic anterior hypothalamus, and aspirin and indomethacin decrease fever produced by pyrogens but not PGEs. Pyrogens produce fever by increasing synthesis and release of PGEs. Hypothalamic PGEs play a role as a central transmitter or modulator in temperature regulation.


[Influence of clonazepam, an anticonvulsant benzodiazepine drug, on the rat brain monoamine containing neurons especially on dopaminergic neurons (author's transl)]. Clonazepam at two doses of 1 mg/kg i.p. significantly decreased 3, 4-dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA) contents in the rat caudatus and cortex but not so in the olfactory tubercle, septum and hypothalamus. The drug decreased dopamine (DA) turnover rate in the caudatus, but did not inhibit tyrosine hydroxylase activity. The drug significantly enhanced stereotyped behavior induced by apomorphine and d-methamphetamine. Clonazepam enhanced apomorphine-induced decrease in striatal HVA, and cortical DOPAC and HVA contents, and d-methamphetamine-induced decrease in cortical DOPAC content. Reserpine pretreatment did not affect apomorphine-induced stereotypy and its enhancement with clonazepam. The drug did not activate adenylate cyclase nor DA-sensitive adenylate cyclase in the striatal homogenates and did not change cyclic AMP content in the caudatus. The drug inhibited phosphodiesterase activity in caudate and cortical homogenates but not in vivo. Clonazepam did not alter ChAc and AChE activities in the caudatus, 6 other cerebral regions and the spinal area. Clonazepam also decreased NE turnover in the caudatus and 5-HIAA contents in the brainstem area. These neurochemical and behavioral effects of clonazepam indicate probable postjunctional DA stimulation in the striatum and cortex of the type not linked with adenylate cyclase and phosphodiesterase but probably due to activation of inhibitory gamma-amino butyric acid (GABA) neurons on the strio-nigral pathway.


Deep tendon reflex in Eaton-Lambert syndrome. The mechanism of absent or decreased deep tendon reflex in Eaton-Lambert syndrome was studied. There was no evidence suggestive of the presence of a neuropathy. On the other hand, a brief (about 10 seconds) maximal voluntary contraction made the absent deep tendon reflexes elicitable, which suggests that the block of neuromuscular transmission in Eaton-Lambert syndrome is responsible for the absent or decreased deep tendon reflex. Such enhancement of the decreased deep tendon reflex in Eaton-Lambert syndrome might be helpful in differentiating neuropathy and Eaton-Lambert syndrome.


Effect of ACTH 4-10 on passive avoidance of rats lacking vasopressin (Brattleboro strain). The hypothesis that the effects of ACTH 4-10 on avoidance are mediated via the release of endogenous vasopressin was investigated. To test this hypothesis, we observed the effect of ACTH 4-10 on the passive avoidance of Brattleboro rats with diabetes insipidus resulting from a total genetic deficiency of vasopressin (DI) and Brattleboro rats without diabetes insipidus (HE). Normal Long-Evans rats (LE) were also included for comparison purposes. The results did not support the hypothesis. ACTH 4-10 did influence the passive avoidance of DI rats; this should not have occurred if the release of endogenous vasopressin is necessary for ACTH 4-10 to influence avoidance.


Synovial sarcoma of the soft palate: report of a case. A case of primary synovial sarcoma of the soft palate is reported in a 19 year old man who was in good health and free of recurrence one year after operation. Radiation therapy was selected and a dose of 7600 rads was given. The presence of hyaluronic acid was investigated using the critical electrolyte concentration method. The tumor was considered histogenetically to be derived from undifferentiated mesenchymal tissue.


An unusual multifocal leiomyosarcoma of the stomach: a light and electron microscopic study. A multifocal leiomyosarcoma of the stomach originating from the muscularis mucosae with lymph node and distant metastases is described in a 66 year old man. The electron microscopic features of a representative tumor mass and a metastasis confirmed the smooth muscle histogenesis. The light microscopic appearance consistently suggested malignant fibrous histocytoma. The pathological features of gasttric leiomyosarcomas are reviewed with special emphasis on the problem of practical diagnosis. This case also indicates that not all sarcomas with storiform features are necessarily histiocytic in origin.


[Rotavirus as a causative agent of infantile gastroenteritis. Diagnosis and epidemiology (author's transl)]. Some years ago it was not possible in spite of intensive bacteriological and virological work on the etiology of acute infantile gastroenteritis to find any agent that may readily be linked to this disease. Since five years now early sporadic reports about virus-like particles have proved worldwide to be correct and in the meantime have substantially been supported by new findings in that these particles are the main causative agent of infantile gastroenteritis. As part of our electron-microscopic studies some morphological characteristics are shown. The physico-chemical as well as structural properties of the new virus apparently justify its classification into the family of the reoviruses. Rotavirus positive stool specimens were found in 46% of the material sent in by paediatric clinics.


Preliminary studies on the diffusion of bovid herpesvirus 2 in experimentally infected calves. This preliminary study on the diffusion of the Bovid herpesvirus 2 (BHV2) in calves inoculated intravenously, allowed to identify the target organs of the virus. In particular, in the first phase of the infection, i.e. post infection day (PID) 2, the virus resulted extensively widespread in the body of the calf, whereas in a subsequent phase, PID6, the virus was recovered only from the skin, the lymph nodes and the nervous system. Finally virus was not recovered in any of the tissues obtained from the calf killed at PID 12. Based on the results it might be speculated that, under the experimental conditions of these tests, the infection of cattle by BHV2 develops through two stages. The first stage would be characterized by a systemic condition in that the virus is present in the whole organism; the second stage which follows, consists in a localized infection, the virus being present only in some districts of the organism (skin, lymph nodes, nervous system) which could be considered as the definitive target sites for virus replication.


[Structure and function of the eosinophil leucocytes (author's transl)]. It is well established that eosinophilia both in tissue and in the circulation is characteristic for many clinical conditions. They include diseases associated with immediate and delayed type hypersensitivity. Under these conditions the eosinophil leukocyte is a prominent participant at sites of inflammatory reactions. Through their enzymes they are able to counteract the mediators of inflammation, such as histamine, the slow reacting substance of anaphylaxis (SRS-A) and the platelet aggregating factor (PAF). In addition, eosinophils exert their sepcific functions during parasitic infection, in which they lead to severe damage of parasites. Eosinophils have also been involved in the process of the replenishment of mediators by dampening the synthesis of mediators in mast cells. Accumulation of eosinophils in tissue or in the circulation is due to chemokinesis and chemotaxis. A great number of eosinophilotactic factors can be generated from cells, such as lymphocytes, basophils, mast cells and polymorphnuclear leukocytes. In addition, several serum components have been shown to exert eosinophilotactic properties. The eosinophilotactic factors differ in molecular weight, chemical structure and their specificty. Eosinophilia is therefore a complex phenomenon: It can be modulated by factors which act on the maturation of the eosinophil, on the production and secretion of eosinophilotactic factors and on the responsiveness of the target cells.


Cell interaction during lymphocyte activation. Adherent cells were separated from stimulated lymphocytes by a layer of agarose to determine the requirement for lymphocyte interaction with adherent cells. The results demonstrated that the presence of plastic adherent cells was obligatory for oxidative activation, but contact of plastic adherent cells with oxidized nonadherent lymphocytes was not. A similar relationship was found to exist between adherent and nonadherent populations during PHA and Con A stimulation. In contrast, the responses of PWM- and ZnCl2-stimulated lymphocytes were not augmented by the presence of adherent cells unless the two populations were in contact.


Relationship between Epstein-Barr virus (EBV)-production and the loss of the EBV receptor/complement receptor complex in a series of sublines derived from the same original Burkitt's lymphoma. Virus production, EBV (P3HR-1 substrain) superinfectability, IdUrd inducibility, EBV receptor and complement (C3) receptor expression were assessed in two independently maintained jijoye lines, the derived P3HR-1 clone that releases a growth inhibitory and cytopathic, non-transforming viral mutant, and in non-producer sublines derived from the P3HR-1 line by the spontaneous cessation of virus production. Both jijoye lines were superinfectable, inducible, and carried EBV and C3 receptors. Virus-producing P3HR-1 cells and recently derived non-producer sublines lacked EBV-receptors and C3 receptors, could not be superinfected, but were IdUrd inducible. Two long-passaged, non-producer sublines of P3HR-1 reexpressed EBV and C3 receptors to an equal degree (different in the two sublines). EBV-superinfectability became partially reestablished in the subline with the higher expression of EBV and C3 receptors. These findings support the hypothesis that the EBV-receptor/C3 receptor negativity of the producer P3HR-1 sublines and their recent non-producer derivatives is due to negative selection by the growth-inhibitory, cytopathic P3HR-1 virus variant. The closely linked disappearance and reappearance of EBV-receptors and complement receptors gives further support to the idea that these two receptors are either identical or closely linked constituents of the cell membrane.


Active immunization against murine radiation-induced leukemia using a sarcoma virus pseudotype. Immunization of C57BL/Ka mice against the radiation leukemia virus (Rad LV) markedly reduced their susceptibility to development of leukemia after X-radiation. The active immunogen used consisted of a sarcoma virus pseudotype of Rad LV which induces regressing sarcomas in young adult mice. These immunized animals were challenged with four weekly 160-rad X-ray exposures. The appearance of lymphomas and leukemias resulting from such irradiation was delayed and their incidence significantly decreased. These results indicate that oncornavirus immunization may be used to reduce the incidence of murine leukemias which are triggered by a physical agent.


Murine Rous-sarcoma-specific immunity detected by leukocyte adherence inhibition: inhibitory effect of normal serum. The standard one-stage lymphocyte adherence inhibition (LAI) assay was used to investigate cellular and humoral immune responses within the murine Rous sarcoma system. Significant specific cellular reactivity to Rous sarcoma antigen extracts was detected when the responder peritoneal exudate cells (PEC) were obtained from mice bearing or immunized against primary or transplanted Rous sarcomas; no cellular reactivity to control methylcholanthrene (MC)-induced tumor antigen extracts was observed. Similarly, specific cell-mediated recognition of MC tumor antigen extract was demonstrated. Initial experiments designed to assess the role of serum components in the LAI assay demonstrated that normal mouse serum of C57BL/10ScSn, B10.D2, or A/WySn origin, either fresh or frozen, obtained from old (over 7 months) or young (under 6 weeks) mice non-specifically abrogated the specific loss of PEC adherence.


Induction of mammary tumors in C57BL/HAAG female mice by a low oncogenic mammary tumor virus. Mammary tumor virus (MuMTV)-negative mouse substrain C57BL/Haag foster-nursed by strain DD becomes a line with a moderately high incidence of mammary tumors occurring in the females at a late age. Electron microscopy revealed B particles in the tumors, providing additional evidence for the propagation and transmission of DD-MuMTV in C57BL/HaagfDD. Since both albino strains DD and RIII originated in Europe, develop pregnancy-dependent mammary tumors, carry black and agouti genes (cc, BB, AA), and therefore may be related, evidence is presented which suggests that the two naturally occurring MuMTVs from DD and RIII may also be related, and that they may share a common origin.


Cadmium induced changes in the liver of langurs (Presbytis entellus-entellus dufresne). 1- Cadmium-induced hepatic disturbances in Langurs have been studied following a single low dose administration of the salt (Cd Cl2 4 mg/kg s.c.). 2-Serum transaminases, choelsterol and liver glycogen levels were elevated. Alkaline phosphatase levels were in normal range. The blood sugar was at a low level. 3- Degranulation, vacuolization and distortion of the liver cells and lobules were conspicuous. 4- In conclusion this study would indicate that increased serum enzyme activity and increased plasma choelsterol levels are a manifestation of tissue damage. It would seem plausible to translate these observations in terms of similar infarcts occurring in man.


Lysis of RSV-transformed Japanese quail cells by a factor from normal quail serum. Normal sera of Japanese quails caused lysis of tumor cells from a Rous sarcoma virus (RSV)-induced quail tumor (QT cells). Other tumor cell lines, including RSV-transformed quail embryo cells and methylcholanthrene-induced quail tumors, were not lysed. This naturally occurring cytolytic factor (NCLF) was sensitive to heating at 56 degrees C, zymosan, and inulin, and it required magnesium but not calcium for the expression of its activity. These results suggested that NCLF activity was mediated by complement activated through an alternative pathway. This possible complement activation occurred in the absence of specific antibodies to the target cells.


The radiolysis of glyceraldehyde-3-phosphate dehydrogenase. The yields in molecules per 100 eV for active-site and sulphydryl loss from glyceraldehyde-3-phosphate dehydrogenase have been determined in nitrous-oxide-saturated, aerated and argon-saturated solutions. Molecular hydrogen peroxide produces a sulphenic acid product, which can be repaired by post-irradiation treatment with dithiothreitol. Comparison of the yields under various conditions showed that in aerated solutions both .OH and .O2-radicals inactivated the enzyme with an efficiency of about 26 per cent. However, the efficiency of .OH in air-free solutions was less, and inactivation by .H and eaq- did not appear to be appreciable. There is a correlation between SH loss and loss of active sites.


[Clinial picture and localization of skin metastasis of visceral carcinomas]. Seven cases with secondary skin carcinomas are described. The primary tumor was located at the tongue, the larynx, the thyroid, the abdomen, the ovaries, the collum uteri and the rectum. From the literature 60 other patients with secundary skin carcinomas and 100 primary carcinomas were evaluated. Clinical evidences for a secundary skin carcinoma are: unusual localization, multiple occurrence and an even surface. It was examined whether the localization of the secundary skin tumor refers to the localization of the primary tumor.


Radionuclide imaging of bowel infarction complicating small bowel intussusception in dogs. Technetium-99m (99mTc)-pyrophosphate was investigated for use as an indicator of intestinal infarction in intussuscepted bowel. Irreducible intussusceptions were created in eight adult mongrel dogs. Technetium-99m-pyrophosphate was then injected intravenously 24 and 48 hrs later for external scanning. In six of the dogs, infarction developed in the intussusception, and each demonstrated increased uptake of 99mTc-pyrophosphate on in vivo scintiscans. The two dogs without infarction showed no increase uptake of the radionuclide. Well-counting and specimen scanning confirmed increased radionuclide in the infarcted intussusceptions. These observations suggest that 99mTc-pyrophosphate is a reliable indicator of the vascular compromise that sometimes occurs with intestinal intussusception.


Heavy-ion radiography: density resolution and specimen radiography. Heavy-ion radiography is performed by the passage of a beam of nuclei accelerated to energies of several hundred MeV/nucleon through an object. The technique of recording transmitted nuclei in a downstream stack of plastic sheets affords excellent resolution of density by recording the nuclei only at their stopping points. Imaging of a phantom--which stimulated tumors of low density contrast in a body part--by conventional radiography, computed tomographic scanning and the heavy-ion technique indicated superior density resolution for heavy-ion imaging at radiation dose. Superior imaging of tumors in pathologic specimens was demonstrated for heavy-ion imaging compared to conventional radiography. Values of stopping power for various tumors and normal tissues were determined by a computer-aided technique. Heavy-ion radiography shows promise for superior imaging of low contrast tumors at relatively low radiation low levels.


Metabolism of cyclohexane carboxylic acid by Alcaligenes strain W1. Thirty-three microorganisms capable of growth with cyclohexane carboxylate as the sole source of carbon were isolated from mud, water, and soil samples from the Aberystwyth area. Preliminary screening and whole-cell oxidation studies suggested that, with one exception, all of the strains metabolized the growth substrate by beta-oxidation of the coenzyme A ester. This single distinctive strain, able to oxidize rapidly trans-4-hydroxycyclohexane carboxylate, 4-ketocyclohexane carboxylate, p-hydroxybenzoate, and protocatechuate when grown with cyclohexane carboxylate, was classified as a strain of Alcaligenes and given the number W1. Enzymes capable of converting cyclohexane carboxylate to p-hydroxybenzoate were induced by growth with the alicyclic acid and included the first unambiguous specimen of a cyclohexane carboxylate hydroxylase. Because it is a very fragile protein, attempts to stabilize the cyclohexane carboxylate hydroxylase so that a purification procedure could be developed have consistently failed. In limited studies with crude cell extracts, we found that hydroxylation occurred at the 4 position, probably yielding the trans isomer of 4-hydroxycyclohexane carboxylate. Simultaneous measurement of oxygen consumption and reduced nicotinamide adenine dinucleotide oxidation, coupled with an assessment of reactant stoichiometry, showed the enzyme to be a mixed-function oxygenase. Mass spectral analysis enabled the conversion of cyclohexane carboxylate to p-hydroxybenzoate by cell extracts to be established unequivocally, and all of our data were consistent with the pathway: cyclohexane carboxylate --> trans-4-hydroxycyclohexane carboxylate --> 4-ketocyclohexane carboxylate --> p-hydroxybenzoate. The further metabolism of p-hydroxybenzoate proceeded by meta fission and by the oxidative branch of the 2-hydroxy-4-carboxymuconic semialde-hyde-cleaving pathway.


Genetic control of galactokinase synthesis in Saccharomyces cerevisiae: evidence for constitutive expression of the positive regulatory gene gal4. Temperature-sensitive (ts) mutants for the gal80 and gal4 genes of Saccharomyces cerevisiae were isolated and characterized. These mutants were classified into two categories; one showed thermolability (TL) and the other showed temperature-sensitive synthesis (TSS) of the respective products. Both the TL and TSS gal80 mutants are constitutive for galactokinase activity at 35 degrees C and, because they are derived from a dominant super-repressible GAL80s mutant, are uninducible at 25 degrees C. Both the TL and TSS gal4 mutants are galactose negative at 35 degrees C and galactose positive at 25 degrees C. None of the ts gal4 mutations affected the thermolability of galactokinase activity in cell extracts. Induction of galactokinase activity was studied with these mutants. The results indicate that the gal80 gene codes for a repressor and the gal4 gene codes for a positive factor indispensable for the expression of the structural genes or their products. However, striking evidence that the expression of the gal4 gene is constitutive and not under the control of gal80 was provided by a kinetic study with the TL gal4 mutant. The TL gal4 mutant pregrown in glycerol nutrient medium at 35 degrees C showed a prolonged lag period (35 min) in the induction of galactokinase activity at 25 degrees C, whereas the same mutant pregrown at 25 degrees C showed the same lag period as those observed in the wild-type strain and a revertant clone derived from the TL gal4 mutant (15 min).


Citrobacter O-antigens: structure of the O-antigenic polysaccharide from Citrobacter sp. 396. The structure of the O-specific polysaccharide moiety of the lipopolysaccharide from Citrobacter 396 was elucidated by composition, methylation, and periodate oxidation studies. The repeating unit consists of four 2-linked mannoses and one 3-linked N-acetylglucosamine. One of the mannose units is substituted at C3 with alpha-glucose, and one is substituted at C3 with alpha-(2-O-acetyl)-abequose. All the mannosyl linkages appear to have the beta-configuration; the N-acetylglucosaminyl linkage has the alpha-configuration. In bacterial agglutination and passive hemagglutination in some Salmonella antisera, Citrobacter 396 as well as its O-antigenic lipopolysaccharide expressed the serological factors 5 and 6. In corroboration of our structural studies, this showed the presence of alpha-(2-O-acetyl)-abequosyl-1,3-mannose (factor 5) and alpha-glucosyl-1,3-mannose (factor 6).


Acquisition of ability to utilize Xylitol: disadvantages of a constitutive catabolic pathway in Escherichia coli. Ribitol+ strains of Escherichia coli acquire the ability to utilize xylitol by mutating to constitutive production of the coordinately controlled ribitol catabolic enzymes ribitol dehydrogenase (RDH) and D-ribulokinase (DRK). Such strains concomitantly acquire toxicity to galacitol and L-arabitol, and to D-arabitol if they are unable to utilize it for growth. Strains selected for resistance to these polyols have DRK structural gene mutations or other mutations that eliminate the constitutive production of DRK, consistent with the view that DRK phosphorylates those polyols to toxic substances. Ribitol+ strains selected for growth on 8 mM xylitol fail to grow on 30 mM xylitol. A product of ribitol and xylitol catabolism represses synthesis of RDH, an enzyme required for growth on xylitol. At 30 mM xylitol, greater than 99% of RDH synthesis is repressed. Strains that grow on 8 mM xylitol can mutate to grow on 30 mM xylitol. Such mutants, relieved of this repression, overproduce RDH, resulting in good growth on the poor substrate, xylitol, but poor growth on the normal substrate, ribitol.