[The Tübingen immediate implant in clinical studies]. 95 Tuebinger immediate implants--four different types--were clinically tested. The longest time of observation was 2 1/2 years. Of the type which so far has been shown to be the best (54 implants), one was lost. The quota of losses was higher in the other types. Preservation depends on the shape of the implant head and particularly on the size  of the lacuna. Best results were achieved by the 54 implants with a lacuna radius of 100 micron. Smaller lacunae increase the failure rate.


[The sulcus fluid flow rate (SFFR) in Tübingen immediate implants made from aluminum oxide ceramics]. Determination of sulcus fluid flowrate was used to gain an insight into the peri-implantar tissue-reactive behaviour in response to Tuebinger immediate implants. The evaluation of 570 measurements on 36 implants and corresponding control teeth showed no difference between natural teeth and healthy gum and implant. Mobility influences the SFFR even in implants.


Absorption, biotransformation, and storage of halothane. Current knowledge of the quantitative aspects of biotransformation of halothane and the fate of its metabolites are reviewed. Absorbed quantities of the inhalation anesthetic average 12.7 and 18 g during 1 and 2 hr, respectively, of anesthesia. Reported fractions of halothane recovered as urinary metabolites range from 10 to 25%. An analysis of reports of bromide ion accumulation in plasma during and following anesthesia suggests that metabolism of halothane continues for 20-40 hr after exposure and that 22-24% of absorbed halothane is metabolized following 8 hr of anesthesia. Half-times for excretion of trifluoroacetic acid (TFA), a principal urinary metabolite of halothane, tend to confirm that biotransformation proceeds for 2 to 3 days following exposure. Other urinary metabolites which occur in small amounts include a dehydrofluorinated metabolite of halothane conjugated with L-cysteine and N-trifluoroacetyl-n-ethanolamine, both of which are evidence of the occurrence of reactive intermediates during the metabolism of halothane. Support for free radical formation has come from in vivo and in vitro demonstrations of stimulation of lipoperoxidation of polyenoic fatty acids by halothane. Irreversible binding of halothane metabolites to microsomal proteins and phospholipids has been shown to depend on the microsomal P-450 cytochrome system. Irreversible binding is increased by microsomal enzyme induction and by anaerobic conditions. Hypoxia increases irreversible binding to phospholipids, augments the release of inorganic fluoride and is followed by centrilobular hepatic necrosis. It is concluded that one-fourth to one-half of halothane undergoes biotransformation in man. One fraction is excreted as trifluoroacetic acid, chloride and bromide. A second fraction is irreversibly bound to hepatic proteins and lipids. Under anaerobic conditions fluoride is released, binding to phospholipids is increased, and hepatic necrosis may occur.


Detection of mutagenic activity in the urines of anesthesiologists: a preliminary report. While halothane was without mutagenic activity in the Salmonella mutagenicity assay, even in the presence of microsomal fractions, the urines of anesthesiologists induced mutations of the base-substitution type.


Toxicity of chloroprene, 1,3-dichlorobutene-2, and 1,4-dichlorobutene-2. A review of the toxicity of 1,3-dichlorobutene-2 (1,3-DCB), 1,4-dichlorobutene-2 (1,4-dcb), and 2-chlorobutadiene, 1,3 (beta-chloroprene) was undertaken with an emphasis on assessing the hazards of these materials in the industrial situation. 1,3-DCB is a by-product of beta-chloroprene from the acetylene route, with 1,4-DCB is an intermediate in the production of beta-chloroprene from the butadiene route, the production route used in the U.S. Presented in the review is a summary of the acute toxicity including mutagen testing, skin, eye, and inhalation testing of these compounds. In addition, subacute inhalation testing, embryotoxicity, teratogenicity, and carcinogenicity are also reviewed where the information is available.


Biodehalogenation.

Biodehalogenation. Haloorganic biocides are widely employed as soil fumigants to combat the destructive action of plant parasitic nematodes and fungi. These substances are dehalogenated by soil organisms, principally species of Pseudomonas and Flavobacteria, to nontoxic metabolities. The paths of metabolism of a vareity of simply alkyl halides are described with emphasis upon the biodehalogenation step.


Metabolism and mutagenicity of halogenated olefins--a comparison of structure and activity. Chlorinated ethylenes are metabolized in mammals, as a first step, to epoxides. The fate of these electrophilic intermediates may be reaction with nucleophiles (alkylation), hydrolysis, or intramolecular rearrangement. The latter reaction has been studied in the whole series of chlorinated epoxiethanes. The rearrangement products found were: acyl chlorides (tetrachloro-, trichloro-, and 1,1-dichloroethylenes), or chlorinated aldehydes (1,2-dichloroethylenes, cis- and trans-, vinyl chloride). The metabolities found in vivo are identical with, or further derivatives of these rearrangment products, with one important exception: trichloroethylene. With this compound, in vivo rearrangement yields chloral exclusively. The mechanism of the different rearrangement has been identified as a Lewis acid catalysis. All chlorinated ethylenes have been investigated in a tissue-mediated mutagenicity testing system. The prominent molecular feature of those with mutagenic effects (trichloro-, 1,1-dichloro-, and monochloroethylene) is unsymmetric chlorine substitution which renders the epoxides unstable, whereas symmetric substitution confers relative stability and nonmutagenic property.


Mutagenicity of halogenated alkanes and their derivatives. The ability of a series of haloalkanes, haloethanols and haloacetaldehydes to induce mutations in Salmonella typhrimurium and preferentially to inhibit the growth of DNA polymerase-deficient E. coli (pol A(+)/pol A(-)) was investigated. For the haloalkanes investigated, the order of reactivities towards the E. coli pol A(+)/pol A(-), was: 1,1,2,2-tetrabromoethane > 1,1-dibromoethane > 1,1,2,2-tetrachlorethane > 1,2-dibromoethane = 1,5 dibromopentane > 1,2-dibromo-2-methylpropane > 1-bromo-2-chloroethane > 1,2-dichloroethane. In the standard Salmonella mutagenicity assay the order of these substances was 1,2-dibromoethane = 1,5-dibromopentane > 1,2-dibromo-2-methylpropane >/= 1-bromo-2-chloroethane > 1,1,2,2-tetrachloroethane = 1,1-dibromoethane > 1,2-dichloroethane. 1,1,2,2-Tetrabromoethane was negative in the standard assay but strongly mutagenic when tested in suspension. It would appear that the discrepancy between the two procedures is due to the fact that bactericidal mutagens cannot be scored reliably in the standard Salmonella assay. The order of reactivity of 2-haloethanols in E. coli pol. A(+)/pol A(-), was 2-iodo > 2-bromo-> 2-chloroethanol. In the Salmonella assay the order was 2-bromo-> 2 iodo- >2-chloro-ethanol. 2-Fluoroethanol and ethanol were devoid of activity in both assays. For the 2-haloacetaldehydes the reactivities in the E. coli system were 2-bromoethylacetate > 2-bromoacetaldehyde = acetaldehyde > 2-chloroacetaldehyde while in the Salmonella system the order was 2-bromoethylacetate > 2-chloroacetaldehyde. Acetaldehyde had minimal activity, while 2-bromoacetaldehyde was without activity but strongly bactericidal.


Some studies on equine strains of Escherichia coli. A detailed study was made of 194 equine strains of E. coli, involving biochemical and serological characters. In these, the equine strains closely resembled E. coli from other sources, and shared antigenic characters with strains isolated from different animal species.


Late effects of air pollution with special reference to lung cancer. The Department of Environmental Hygiene of the National Swedish Environment Protection Board and of the Karolinska Institute have prepared an extensive review on health effects of air pollution, to be used by the Swedish Parliamentary Committee on Energy and the Environment. This report forms the basis for one part of the review, that on late effects. Much of the work on the review, is the result of a team effort involving researchers from numerous organizations.


Fluorescence energy-transfer studies on the pyruvate dehydrogenase complex isolated from Azotobacter vinelandii. Fluorescence energy transfer has been employed to estimate the minimum distance between each of the active sites of the 4 component enzymes of the pyruvate dehydrogenase multienzyme complex from Azotobacter vinelandii. No energy transfer was seen between thiochrome diphosphate, bound to the pyruvate decarboxylase active site, and the FAD of the lipoamide dehydrogenase active site. Likewise, several fluorescent sulfhydryl labels, which were specifically bound to the lipoyl moiety of lipoyl transacetylase, showed no energy transfer to either the flavin or thiochrome diphosphate. These observations suggest that all the active centers of the complex are quite far apart (greater than or equal to 40 nm), at least during some stages of catalysis. These results do not preclude the possibility that the distances change during catalysis. Several of the fluorescent probes used possessed multiple fluorescent lifetimes, as shown by determination of lifetime averages by both phase and modulation measurements on a phase fluorimeter. These lifetimes are shown to result from multiple factors, not necessarily related to multiple protein conformations.


Replication of M-13 DNA in plasmolysed Escherichia coli cells. Structure of a replicative intermediate with restricted binding of intercalating dyes. DNA molecules with restricted binding of intercalating dyes are observed as replicative intermediates during the replication of bacteriophage M-13 duplex DNA in a cellular system in vitro prepared by plasmolysis of M-13-am5-infected Escherichia coli cells. Restriction of dye binding is abolished by heating the DNA to 80 degrees C, but can be recovered by slow cooling of the heat-treated DNA. Radioactive pulse-label incorporated by these molecules is found exclusively in elongated viral strands of more than one genome length. In the electron microscope this DNA fraction is seen to contain a significant number of duplex DNA rings with two single-stranded tails protruding from the same region of the ring. It is proposed that these structures arise by branch migration during the isolation of replicating molecules containing only one single-stranded tail. The topological constraint in these molecules is most likely caused by base-pairing between partially complementary regions of the two single-stranded tails.


Valylation of the two RNA components of turnip-yellow mosaic virus and specificity of the tRNA aminoacylation reaction. A comparative study of the aminoacylation of the two RNA components of turnip yellow mosaic virus, of yeast tRNAVal, tRNAfMet and of tRNAPhe by purified yeast valyl-tRNA synthetase is reported. Aminoacylations were performed in the presence of pure yeast tRNA nucleotidyltransferase, since 85% of the viral RNA molecules lacked the 3'-adenosine. We find that aminoacylation of the viral RNAs, like tRNA aminoacylation, reflects an equilibrium between the acylation and deacylation reactions. The kinetic parameters of TYM virus RNA valylation resemble the values found for tRNAVal valylation; in particular, there is a strong affinity between the viral RNA and valyl-tRNA synthetase and the rate constant for TYM virus RNA valylation is only slightly lower than that for tRNAVal. This result contrasts with the reduced rates observed in tRNA mischarging, and suggests that the viral RNA could be easily aminoacylated in vivo. Considering the fact that the 3'-terminal sequence of TYM virus RNA has only a few points of resemblance to a tRNA sequence, we propose that there are some structural motifs found in both tRNAVal and TYM virus RNA which are brought in a similar spatial arrangement recognized by valyl-tRNA synthetase.


A study of unwinding of DNA and shielding of the DNA grooves by RNA polymerase by using methylation with dimethylsulphate. The dimethylsulphate method has been used to study the complexes of RNA polymerase (Escherichia coli) with DNA of T7 phage, poly[d(A--T)] and fragments of calf thymus DNA protected against DNase digestion by RNA polymerase. The binding of RNA polymerase to DNA significantly increases the formation of 1-methyl-adenine produced by methylation of the single-stranded DNA region, diminishes by about 10% the formation of 3-methyl-adenine by methylation within the minor groove and does not affect the formation of 7-methyl-guanine by methylation within the major DNA groove. The presence of nascent RNA decreases the formation of 1-methyl-adenine in DNA of the complex by about 30%. The initiation of RNA synthesis or RNA synthesis itself does not influence the methylation of the major groove but shielding of the minor groove increases by about twice as much. These results suggest that RNA polymerase, upon binding, breaks Watson-Crick base-pairing in a DNA region of about 15-base-pairs long, that nascent RNA forms a duplex with DNA of about 10-base-pairs long; and that the enzyme weakly interacts with DNA along its grooves and preferentially makes contacts with the minor groove.


Interaction between penicillin and the DD-carboxypeptidase of the unstable L-form of Proteus mirabilis strain 19. Binding of penicillin to the DD-carboxypeptidase of the unstable spheroplast L-form of Proteus mirabilis results in the rapid formation of a modified enzyme-inhibitor complex which in turn undergoes rapid decay into reactivated enzyme and an antibiotically inactive penicillin degradation product. Major antibiotic metabolites recovered from such interactions were benzylpenicilloic acid and phenoxymethylpenicilloic acid from benzylpenicillin and phenoxymethylpenicillin, respectively, suggesting a second enzymic function of the DD-carboxypeptidase as a penicillinase of low efficiency. Statistical analyses made with the help of a linear regression program show that the enzyme interacts with the substrate UDP-N-acetylmuramoyl-L-alanyl-D-gamma-glutamyl-(L)-meso-2,6-diaminopimelyl-(L)-D-alanyl-D-alanine and either benzympenicillin or carbenicillin in a non-competitive manner.


Anion binding to yeast phosphoglycerate kinase. The single thiol of yeast phosphoglycerate kinase was labelled with the chromophoric sulfhydryl reagent, 2-chloromercuri-4-nitrophenol. Sequential additions of individual anions to this modified enzyme brought about a decrease in absorbance at 410 nm that reflected the degree of saturation of the enzyme with anion. The binding curves were analyzed to determine the dissociation constants of a number of anions with charges varying from--1 to--4.1. A linear relationship was found between the charge of the anion and the negative logarithm of the dissociation constant for the labelled enzyme-anion complex. The highly charged anions, such as ATP, bound more tightly than did anions with less charge, such as Cl-. The average number of binding sites for those anions for which accurate results could be obtained was 1.06 mol per 47000 g of enzyme. Several lines of evidence suggested that titration of the active center was not being monitored. Anions bound to phosphoglycerate kinase decreased the rate of reaction between the enzyme thiol and 5,5'-dithiobis(2-nitrobenzoic acid). The relationship between the degree of saturation of the anion binding site and the reaction rate constant was used to calculate the dissociation constant between anion and enzyme. Dissociation constants determined in this manner were in good agreement with those determined by titration of the enzyme-mercurial complex.


Alteration of the intracellular concentration of aminoacyl-tRNA synthetases and isoaccepting tRNAs during amino-acid limited growth in Escherichia coli. Growth of Escherichia coli AB 2271 under threonine or isoleucine deficiency leads to a depression of the threonyl-tRNA synthetase and isoleucyl-tRNA synthetase respectively. During this amino-acid-limited growth the concentrations of isoaccepting fractions of the cognate tRNA species were changed, as demonstrated by their altered reversed-phase-5 chromatograms. But, in addition, the profiles of the isoacceptors of all other tRNA species investigated, i.e. of tRNAsLeu, tRNAsSer and tRNAsArg were also altered. This means that, if there is a correlation between regulation of the level of an aminoacyl-tRNA synthetase and its cognate isoaccepting tRNAs, it is superimposed by the effect of amino acid limitation upon the concentration of all isoaccepting tRNAs. So far drastic changes in profiles of isoaccepting tRNAs have only been observed under unbalanced growth in relaxed cells or during treatment with antibiotics. Here we demonstrate that similar heavy alterations in patterns of isoaccepting tRNAs occur in a proven stringent E. coli strain growing exponentially under amino acid limitation. Thus the observed changes in the profiles of isoaccepting tRNAs during amino acid limitation signal a meaningful biological function of those newly or increasingly occurring isoaccepting tRNAs. During the growth under amino acid limitation the total acceptor activity of eight investigated tRNA species, however, stayed unchanged, except that under threonine-limited growth the total amount of tRNAIle was reduced to about half and that of tRNAGlu increased; both tRNA species of these isoacceptors are known [30,31] as spacers between ribosomal RNAs.


Methionyl-tRNA synthetase from Escherichia coli. Absence of interaction between the metal ion and the purine ring of ATP in the L-methionine activation site. Enhancement of the nuclear relaxation rates by manganese has been used to derive manganese--purine-ring distances in the activation site of methionyl-tRNA synthetase. This is possible with the help of an abortive complex between the enzyme, methionine, adenosine, pyrophosphate and manganese which simulates an intermediate species of the activation reaction. It is found that the distances between the manganese ion and the purine ring are too high (greater than 0.8 nm) to allow interaction between them. Thus, metal-purine interaction is involved neither in the catalytic mechanism nor in the stabilization of abortive synergistic complexes [S. Blanquet, G. Fayat and J. P. Waller (1975) J. Mol. Biol. 94, 1-15].


Cerulenin-induced changes in the lipopolysaccharide content and phospholipid composition of Proteus mirabilis. Inhibition of Proteus mirabilis growth by cerulenin, a specific inhibitor of fatty acid biosynthesis, was reversed by exogenously supplied fatty acid mixtures containing oleic acid and palmitic or pentadecanoic acids. The growth rate of the cells treated with cerulenin in the presence of the fatty acid mixtures was slower, however, than that of untreated cells, and their lipopolysaccharide content was decreased by 30-50%, resulting in an increased sensitivity of the organisms to rifamycin and vancomycin. Polyacrylamide gel electrophoresis of the lipopolysaccharide fraction from cerulenin-treated cells revealed that of the two P. mirabilis lipopolysaccharide types, the relative amount of the higher molecular weight lipopolysaccharide was reduced from 50% to 30% of the total lipopolysaccharide. Fatty acid analysis of the phospholipid and lipopolysaccharide fractions from cells grown with cerulenin, pentadecanoate, and oleate revealed that over 60% of the native even-numbered fatty acids of the phospholipid fraction was substituted by the odd-numbered fatty acid, while no incorporation of either the pentadecanoate or oleate could be demonstrated in the lipid A moiety of the lipopolysaccharide. The only change in the lipid A observed was an increase in the content of 3-hydroxymyristic acid accompanied by a decrease in the nonhydroxylated fatty acids, supporting the highly conserved nature of this molecule.


The interaction of daunomycin with polydeoxynucleotides. The ability of daunomycin to bind to various DNA polymers has been sutided by thermal denaturation, spectrophotometric analysis and inhibition of the polymerisation reactions catalysed by Escherichia coli DNA polymerase I and rat liver DNA polymerase alpha. The quantitative binding measurements revealed that the antibiotic binds tightly to all synthetic polydeoxynucleotides studied. The results demonstrated that daunomycin can bind with equal affinity to dG . dC or dA . dT basepaired sequences. However, the number of binding sites per nucleotide for poly(dA) . poly(dT) is significantly lower than that found for poly(dA-dT) . poly(dA-dT), thus indicating an appreciable preference of the drug for the alternating copolymer. The inactivation of the template properties of the synthetic DNA polymers in the DNA polymerase system is consistent with their daunomycin binding ability. However, a lack of correlation was observed between the drug binding ability of different DNA polymers and the binding-induced stabilisation of the double helix to heat denaturation.


The steady-state kinetics of yeast phosphoglycerate kinase. Anomalous kinetic plots and the effects of salts on activity. 1. A re-investigation of the kinetics of yeast phosphoglycerate kinase in the direction of 1,3-bisphosphoglycerate formation has been carried out, covering a 1000-fold range in substrate concentrations. A variety of improved spectrophotometric and fluorimetric assay procedures have been used. 2. Kinetic plots proved to be non-linear for each variable substrate. A variety of checks have been carried out to show that this is not due to artifacts in the assay procedures or heterogeneity of the enzyme preparation. 3. The effects of a variety of salts on the activity of the enzyme have been examined. Most salts, especially those with multivalent anions, can cause activation of the enzyme, but inhibit at high concentration. 4. The salt effect is shown to be principally due to anions rather than cations, and not to ionic strength changes. Sulphate, as one of the most effective anions has been used in most comparisons. 5. Salt activation is steepest when the substrate concentrations are low; maximum activation has been about 5-fold with 0.2 mM MgATP and 0.2 mM 3-phosphoglycerate. Inhibition at the higher salt concentrations is strongest at the same substrate concentrations as when activation is steepest, indicating a link between the two effects. 6. The presence of 20 mM or more Na2SO4 converted non-linear kinetic plots to linear ones. A study of the kinetics in the presence of 40 mM Na2SO4 was interpreted in terms of a random sequential binding mechanism, with sulphate acting as a competitive inhibitor. 7. Possible explanations for these anomalous results are discussed in terms of several mechanisms which have been shown to apply in other systems.


X-ray and neutron small-angle scattering studies of the complex between protein S1 and the 30-S ribosomal subunit. X-ray neutron solution scattering experiments have been done to investigate the influence of the binding of ribosomal protein S1 on the conformation of the 30-S ribosomal subunit of Escherichia coli. The following conclusions were made. 1. The alterations (if any) in conformation of the non-S1 parts of the 30-S subunit induced by S1 binding are too small to be detected (less than 0.1 nm change in radius of gyration). 2. The center of gravity of protein S1 bound to the 30-S subunit is quite far from the center of gravity of the particle (approximately 7.5 nm).


Effects of PCA and DMAE on the namatode Caenorhabditis briggsae. Concentration of 6.8 mM DMAE did not retard age pigment accumulation in Caenorhabditis briggsae. However, when the nematodes were exposed to 6.8 mM PCA + 6.8 mM DMAE combined, the accumulation of age pigment was significantly retarded. A combination of 3.4 mM DMAE + 3.4 mM PCA had no effect on age pigment. It is concluded from this study that PCA and DMAE act in concert to produce the observed effect on age pigment. In respect to this parameter neither molecule was effective alone. The results indicate that the effect of centrophenoxine on age pigment might be enhanced by retarding the hydrolysis of centrophenoxine. The accumulation of electron dense aggregates, thought to be aggregates of cross-linked molecules, was reduced by 6.8 PCA + 6.8 DMAE. It is suggested that centrophenoxine be tested for its ability to remove random, unwanted cross-linkages in higher animals.


Red cell delivery and the function of the marrow-blood barrier: a review. The last step in mammalian erythropoiesis consists of nuclear elimination and delivery of the non-nucleated red cell (reticulocyte) into the circulation. This is accomplished by migration of reticulocytes through the wall of the vascular sinuses which forms an anatomical barrier between the hemopoietic compartment and the circulation. This barrier is instrumental in a complicated mechanism to ensure orderly traffic of new cells in response to the requirement of the organism. Thus, it exerts a control over which cells will migrate into the vascular lumen and when they will do so. Defective red cells and nucleated red cells are prevented from migration; even normal reticulocytes may be temporarily held back if their presence in the circulation would exceed the requirement of the body. Little is known about how this barrier operates to control the red cell delivery. Literature relevant to this subject has been reviewed and an attempt is made to formulate some basic questions in this area.


Cortical projections of the anterior thalamic nuclei in the cat. Unilateral stereotaxic lesions were made in the anterior thalamic nuclei of the cat, and the ensuing terminal degeneration traced to the medial cortex by the methods of Nauta-Gygax and Fink-Heimer. The anterodorsal nucleus projects to the retrosplenial, postsubicular and presubicular areas. These projections appear to be organized in the dorsoventral direction. The posterior portion of the retrosplenial area receives no fibers from the anterodorsal nucleus. Fibers from this nucleus are distributed largely in layer I and in layer III and the deep portion of layer II of the posterior limbic cortex. The anteroventral nucleus sends fibers to the cingular area and parts of the retrosplenial, postsubicular and presubicular areas. These projections appear to be organized in a topical manner mediolaterally. When the lesion involves the parvocellular part of the nucleus, degeneration spreads to the lower lip, bank and fundus of the splenial sulcus. There appears to be an anteroposterior organization in the cortical projections of the anteroventral nucleus. Fibers from the anteroventral nucleus are distributed most profusely in layers IV and III and in the superficial portion of layer I of the posterior limbic cortex. The anteromedial nucleus sends fine fibers to the anterior limbic region and to the cingular, retrosplenial, postsubicular and presubicular areas. The cortical projections of the anteromedial nucleus appear to be topographically organized in the dorsoventral direction. Fibers from the anteromedial nucleus are distributed largely in cortical layers V and VI of the anterior and posterior limbic regions.


Thermogenic mechanisms and their control. The alterations in properties of mitochondria and of plasma membrane of brown adipose tissue and skeletal muscle of cold-acclimated rats are reviewed in order to bring out any adaptive changes which are related to the mechanism of nonshivering thermogenesis, and thus to the enhanced calorigenic action of catecholamines known to exist in these animals. Since prevention of the morphological changes in the mitochondria by treatment of the animals with oxytetracycline during acclimation to cold also prevents the development of the enhanced calorigenic response to the catecholamines it is concluded that the changes noted are either a cause of the development of the increased capacity for nonshivering thermogenesis during acclimation to cold or are secondary to the operation of nonshivering thermogenesis.


Hormonal thermogenesis of "non-norepinephrine" type. Physiological significance and mechanisms controlling thermogenesis due to substances other than norepinephrine (NE) are considered. Epinephrine (E) induces a strong calorigenic effect, which is potentiated by cold adaptation to the level observed after application of NE. Thermogenesis due to E is located to a great extent in visceral organs. Cold acclimation increases the component of epinephrine thermogenesis located in the brown adipose tissue and non-visceral organs, predominantly. Although E and NE act on the same thermogenic effector, their effect is realized via different regulatory sites. Steroid hormones are not necessary for inducing cold resistance and thermogenesis due to NE. The permissive role of steroids and other substances in inducing changes in enzyme activity and synthesis during various cold stress is discussed.


Nutritionally-induced alterations in thyroid hormone metabolism and thermogenesis. Serum 3,5,3'-triiodothyronine (T3) is increased by overnutrition and decreased by starvation. The production rate of T3 was increased by overfeeding (82%), but T4 production did not change. Feeding a weight maintenance diet with high CHO mimiced serum T3 and rT3 changes of overfeeding, substitution of CHO by FAT those of starvation. VO2 increased during overfeeding and in T4 equilibrated volunteers supplemented with 40 microgram T3 daily for 2 weeks. No weight change occurred in the latter subjects. Yet no decrease in VO2 was found when serum T3 was reduced by the administration of iopanoic acid. VO2 decreased during starvation in normal and hypothyroid rats, and in hypothyroid animals replaced with T4 or T3.


Hypothalamic thermosensitivity in mammals. Hypothalamic thermosensitivities of 21 species of mammals ranging in body size from 15 g to 34 Kg are surveyed. It is concluded that hypothalamic thermosensitivity as measured by the proportionality constant relating rate of metabolic heat production to hypothalamic temperature at a thermoneutral ambient temperature is inversely related to body size according to the relationship alphaMHP = -1.46 Wt-.37.


Hibernation as a model for studies on thermogenesis and its control. Mammalian hibernation is characterized by the alternation of prolonged periods of hypothermia and spontaneous arousals with a temporary return to euthermia. Of special interest to the physiology of effectors of thermogenesis are the following points: a) In the second part of the arousal process, the metabolic rate reaches 6 to 8 times BMR, with a body temperature about 10 degrees C lower. Enzymatic adaptations provide for the maintenance of normal reaction rates and regulatory potentials at low temperatures, but how very high thermogenetic rates can be achieved still remains largely unexplained. b) Entrance into hibernation involves a resetting of the hypothalamic thermostat to a lower level, but this is probably not the only intervening regulation. Evidence is presented in favor of a control of thermogenesis at the effector level, in terms both of baseline levels and of loop gains. One likely control factor is acid-base state, which can be changed rapidly and reversibly by ventilation and is characterized by a strong acidosis in hibernation.


Thresholds for Na+ and Ca++ effects on thermoregulation. The evidence for threshold concentrations of Na+ and Ca++ that alter body temperature when introduced into (a) the hypothalamus and cerebral ventricles, and (b) intravenously and by oral ingestion is examined. For hypothamic and ventricular perfusion the threshold for any increase in core temperature (Tc) at rest with excess Na+ is about 10 mM, while there is a linear relationship between the level of excess Ca++ and the decrease in Tc, with a correlation co-efficient of 0.85. With intravenous and oral ingestion the resting threshold plasma concentration for an excess Na+ effect is about 5 mEq/1 per 0.1 degrees C rise in Tc, and the excess Ca++ level is about 1 mEq/1 per 0.1 degrees C decrease in Tc. With exercise, there is a dose-dependent attenuation of the rise in core temperature that is also about 0.1 degrees C per mM excess Ca++.


The identification of the component in the inner membrane of brown adipose tissue mitochondria responsible for regulating energy dissipation. The proton conductance of the inner membrane of hamster brown adipose tissue mitochondria can be regulated in vitro by exogenous purine nucleotides, which bind to a component on the outer face of the inner membrane. This unique mechanism has been proposed to represent the molecular site of non-shivering thermogenesis in this tissue. Using a photo-affinity analogue of ATP, we have identified the nucleotide binding component as a protein of 32,000 daltons.


Clinical studies with d-Trp 6-luteinizing hormone-releasing hormone in anovulatory women. Nine anovulatory patients with hypothalamic-pituitary dysfunction were treated with d-Trp6-luteinizing hormone-releasing hormone, an analog with far greater gonadotropin-releasing activity than luteinizing hormone-releasing hormone. Four of eight patients, who were formerly unsuccessfully treated with clomiphene, human chorionic gonadotropin, and human menopausal gonadotropin, ovulated after treatment with the peptide alone or with peptide preceded by clomiphene, and three became pregnant. The ninth patient, who had amenorrhea and anovulation due to excessive loss of weight caused by anorexia nervosa, also ovulated after treatment with the analog. These results demonstrate the effectiveness of this potent analog for induction of ovulation and pregnancy and point favorably toward clinical applications.


Effect of clomiphene citrate on plasma levels of immunoreactive luteinizing hormone-releasing hormone, gonadotropin, and testosterone in normal subjects and in patients with idiopathic oligospermia. The effect of clomiphene citrate on plasma immunoreactive luteinizing hormone-releasing hormone (LH-RH), gonadotropin, and testosterone levels was investigated in 10 patients with idiopathic oligospermia and in 10 normal volunteers. A daily 100-mg dose of clomiphene citrate induced a marked, significant increase in plasma immunoreactive LH-RH levels, followed by significant increments in gonadotropin and testosterone values. No significant differences were detected in LH-RH, gonadotropin, and testosterone levels between controls and patients with oligospermia either under basal conditions or during clomiphene treatment.


[Modulation of the pituitary response to LH-RH by synthetic sex steroids (author's transl)]. This study was planned in order to investigate the response of the pituitary gonadotropin secretion to the luteinizing hormone-releasing hormone (LH-RH) in each menstrual phase (early follicular, late follicular, luteal) of women with regular menstrual cycles, and the effect of synthetic sex steroids on the response of the pituitary to LH-RH, as compared with the response in the late follicular phase. A dose of 200microgram of LH-RH was administered intramuscularly in the early follicular, and luteal phase of regular menstrual cycles. Three groups of 35 normal women administered 3 kinds of sex steroids were also examined on the 8th to 10th day after medication, except for a long-term administration group of norethindrone. The first group was a mestranol group with two subgroups given a daily administration of 20microgram and 40microgram. The second was a norethindrone group, in which one was a short-term group given a daily administration of 5mg, and another was a long-term group given a daily administration of 10mg to 20mg for more than 150 days. The third was a chlormadinone acetate group given a daily administration of 2mg. Blood samples were obtained before the injection of LH-RH at 15, 30, 60, 90, 120, 180 minutes and 24 hours after the injection. Their sera were separated and frozen at -20 degrees C until assayed. Serum LH and FSH concentrations in each experimental group were used as the standard preparation and expressed as mIU/ml of serum. The results were as follows: 1) Serum LH and FSH responsiveness to LH-RH in women with regular menstrual cycles were greater with regard to late folicular, luteal and early follicular phases, respectively, except for a percent increase of serum LH. 2) The serum LH level in response to the LH-RH injection in the early follicular and luteal phases of the cycle showed a biphasic pattern of elevation characterized by the first pool, releasable LH;  and the second pool, newly synthesized and stored LH in the pituitary. The biphasic pattern of serum FSH was not confirmed in this experiment. 3) Sham disappearance of biphasic pattern of serum LH release in the late follicular phase was attributed to a shifting of LH form the 2nd pool to the 1st pool due to an increase of the endogenous estrogen. 4) The capacity of the pituitary FSH synthesis and storage showed a slight increase in the late follicular phase, which was supposed to be enhanced by estrogen. 5) The serum LH peak in the mestranol group was observed at 120 minutes after the LH-RH injection, which was significantly elevated in the group given a daily administration of 40microgram, as compared with the control group. The LH concentration occupied in a definite volume tended to be reduced in the first pool after the LH-RH injection in the mestranol group and didnt change in the second pool after the injection, as compared with the control group...


Antibody production in organ culture by bursae of mature chickens and the development of immunological compentence. Antibody responsiveness of bursal lymphocytes was studied in vitro. Organ culture of bursal tissue in the presence of antigen, either sheep erythrocytes or bovine serum albumin, results in significant numbers of plaque-forming cells (PFC) compared to controls. The response in organ culture is age-dependent in that only bursae from chickens at least three weeks of age contained significantly increased numbers of secreting cells. Prolonged culture of normally unresponsive bursae from newly hatched birds results in a PFC response to antigen, suggesting that in vitro maturation occurs.


Increased clonogenic (CFU-C, PFU-C) populations from bone marrow and spleen of nude mice. Clonogenic populations from bone marrow and spleen of nude mice and their normal littermates were enumerated in vitro using a methylcellulose supported culture system. This technique allows for the simultaneous quantitation of progenitors of granulocyte-monocyte pathways (colony forming units in culture, CFU-C) and for progenitors of "mesenchymal" elements (plaque-forming units in culture or PFU-C). These populations were distinguished in culture by their growth, characteristics and morphology. CFU-C gave rise to suspended colonies of granulocyte-monocyte composition while PFU-C formed surface-adherent colonies of mesenchymal morphological features (fibroblastic and reticuloendothelial morphology). Significant elevations in the relative and absolute numbers of CFU-C and PFU-C were observed in the bone marrow and spleen of 6 wk old nu/nu mice relative to heterozygous littermates. The results are discussed in terms of non-T cells components involved in cell-medited immunity against neoplastic development.


A single dose study comparing the analgesic effects of diflunisal, acetylsalicylic acid, and placebo in pain following meniscectomy. A single dose experiment was used to evaluate the analgesic effect of diflunisal, a new salicylic acid derivative. Three dose levels of diflunisal (125 mg, 250 mg, and 500 mg) were compared to one dose level of acetylsalicylic acid (ASA) (600 mg) and placebo. The maximal analgesis induced by 500 mg diflunisal was comparable to that of 600 mg ASA. The onset of action was slightly more rapid with ASA but the duration of the analgesic effect was far longer for diflunisal, extending beyond 8 hours after administration. Diflunisal is a promising drug for the treatment of post-operative pain because of its long-lasting effect.


Loxapine in neurotic anxiety: some modifiers of treatment response. The authors describe a double-blind trial of six weeks duration which was designed to compare the anxiolytic properties of chlordiazepoxide, loxapine and placebo in a total of 135 anxious neurotic out-patients.


A comparison of the efficacy and acceptability of two formulations of injectable serenace in the treatment of states of excitement. Seranace was tested in its two formulations of dextrose and saline base and the results confirm no significant differences between the two preparations, either in their efficacy and acceptability or in the control of presenting symptoms.


A comparative clinical trial of mianserin (Norval) and amitriptyline in the treatment of depression in general practice. A double-blind controlled comparative trial of mianserin (Norval) and amitriptyline was conducted in general practice. Fifty-one patients were treated with amitriptyline and fifty-five with mianserin. The dosage for the first week was 25 mg t.d.s. for amitriptyline and 10 mg t.d.s. for mianserin, increasing to 50 mg t.d.s. and 20 mg t.d.s. respectively for the subsequent three weeks. Both drugs proved equally effective in relieving the symptoms of primary depression but mianserin showed a reduced incidence of side-effects which was statistically significant.


Treatment of nausea and vomiting related to anti-cancerous multiple combination chemotherapy: results of two controlled studies. Two controlled double-blind studies were carried out successively on a cancerous out-patient population receiving multiple combination chemotherapy at successive treatment courses to show the anti-emetic efficiency of metopimazine compared to a placebo. The patient was taken as his own control and the treatment order was randomly selected. The first trial--consisting of sixty-seven patients, showed a weak statistically significant difference (0.05 less than p less than 0.10) between metopimazine at doses of 30 mg/day or 15 mg/day and a placebo. The second trial--comparing a higher dose of metopimazine (45 mg/day) among one hundred and sixteen patients, showed a highly statistically significant therapeutic advantage over a placebo (0.001 less than p less than 0.01).


A multicentric clinical trial comparing Otocerol with Cerumol as cerumenolytics. Fifteen general practitioners conducted a randomized, double-blind comparative trial of two cerumenolytics, namely, Otocerol and Cerumol. A total of 106 patients were entered into the study (fifty-three in each group). Otocerol was shown to be marginally better than Cerumol in all parameters evaluated.


Heterogeneity in diabetes mellitus--update, 1978. Evidence for further genetic heterogeneity within juvenile-onset insulin-dependent diabetes mellitus. The concept that idiopathic diabetes mellitus is a genetically heterogeneous group of disorders has been established by twin and HLA studied that have permitted the separation of juvenile-onset and maturity-onset diabetes. The extent of the heterogeneity within the juvenile-onset and maturity-onset types is still in question. On the basis of recent immunologic and metabolic studies we believe that further heterogeneity can be demonstrated within the juvenile-onset diabetic group. We wish to hypothesize that there are at least two distinct forms of juvenile-onset diabetes, one associated with HLA B8 and the other with BW15. The B8 type is characterized by autoimmunity, microangiopathy, and a stronger association with the HLA D locus. The BW15 type is characterized by antibody response to exogenous insulin and a stronger association with the HLA C locus. Greater understanding of the pathogenesis, natural history, and genetics of diabetes mellitus will result as the full extent of genetic heterogeneity is elucidated.


Lysosomes in normal pancreatic beta cells. Lysosomes and their relationships with surrounding organelles were studied in pancreatic B-cells of normal Wistar rats by electron microscopy and cytochemical localization of acid phosphatase (AcPase) and arylsulphatase. Several forms of lysosomes were distinguished and shown to interact frequently with the secretory granules. Two different digestive processes were recognized. During crinophagy, lysosomes directly fuse with secretory granules while, during autophagy, a cytoplasmic area containing secretory granules and/or other organelles is circumscribed before the enzymatic digestion. In addition, lysosomes may transport arylsulphatase into secretory granules apparently not involved in a destructive process. Such a process could also account, at least in part, for the presence of AcPase in a certain number of mature and immature secretory granules.


The effect of residual insulin secretion on exocrine pancreatic function in juvenile-onset diabetes mellitus. Residual beta cell function was studied in 18 juvenile-onset diabetics by measuring serum C-peptide immunoreactivity (CPR) fasting, and after IV injection of glucagon (1 mg). This was compared with the exocrine pancreatic response to an IV infusion of secretin and cholecystokinin-pancreozymin. Outputs of pancreatic bicarbonate, amylase and trypsin were measured. Exocrine secretory pancreatic function was decreased in 14 patients. Fasting and maximal CPR showed that 9 patients had residual insulin secretion. For these 'CPR-secretors' there was a strong correlation between CPR and output of bicarbonate (r = 0.87, p less than 0.005) and amylase (r = 0.7, p less than 0.05), but not with trypsin. These results suggest the existence of an endocrine-exocrine relationship in the pancreas.


Islet activating protein (IAP) derived from the culture supernatant fluid of Bordetella pertussis: effect on spontaneous diabetic rats. The early phase of insulin secretion to an oral glucose load was blunted in spontaneous diabetic rats. The blunted insulin secretion was associated with markedly impaired glucose tolerance. A single injection of the islet activating protein (IAP), a protein derived from the culture medium of Bordetella pertussis, into the spontaneous diabetic rats normalised glucose tolerance. The increase in insulin response to glucose was an important contributing factor to the improvement of glucose tolerance. This curative effect of the IAP on the diabetic state was of long duration; glucose tolerance remained virtually normal over a period of one month in the diabetic rats. Perfusion of the isolated pancreas of the diabetic rats pretreated with IAP showed an increase in insulin response to glucose and loss of suppression of glucagon secretion by noradrenaline.


Glucose stimulated proinsulin biosynthesis rates of turn off after cessation of the stimulus. Proinsulin biosynthesis was stimulated progressively to a plateau level at 45 min by 5.5 mmol/1 glucose. The rate of biosynthesis promptly decreased following cessation of either 15 or 60 min exposure to this concentration of glucose. Actinomycin D had no effect on the rate of decline. In contrast, exposure to 20 mmol/1 glucose caused a prolonged increase in proinsulin biosynthesis which was still apparent at 75 min. After removal of the stimulus there was an initial decrease in the rate of proinsulin biosynthesis followed by persistently elevated rates. When proinsulin biosynthesis was stimulated by 20 mmol/1 glucose in the presence of actinomycin D, there was a rapid switch off of biosynthesis and no persistent effect. Thus, two controls for regulation of proinsulin biosynthesis can be characterised: a prompt, rapidly reversible stimulation in response to low or high glucose concentrations and a persistent stimulation in response to high glucose concentrations. These two effects may represent the translational and transcriptional effects of glucose respectively.


[Effects of the association of Ca-antagonists with nitroderivatives or betablocking drugs in effort angina pectoris (author's transl)]. The effects of the association of calcium antagonists (CAI) with a nitroderivate and a betablocker were studied by means of exercise tests in 8 patients with stable effort angina pectoris. According the statistical model of a latin square 4 x 4, the first 4 patients were tested with the following treatments: placebo, oral; nifedipine (N) 10 mg, oral; N + isosorbide dinitrate (ISDN) 10 mg oral; N + propranolol (Pr) 40 mg, oral. In the second square verapamil 80 mg oral represented the CAI treatment. Compared to placebo, all the treatments produced a significant increase of exercise duration and total work performed before angina. In both the squares the improvement observed after CAI + ISDN was significantly higher than after administration of CAI alone. In both the squares the association of CAI + Pr determined a little, non significant improvement of exercise duration in respect to CAI alone. EKG positivity was delayed by Pr more than angina appearance: hpwever, also this effect was not significant when compared with administration of CAI alone. By the analysis of the changes of heart rate, maximal arterial pressure, ejection time and triple product at the same level of work, a relevant inhibition of myocardial contractility with the adopted doses of CAI can be excluded; the effect of these drugs seems to be due mainly to a decrease of arterial pressure, and, when associated to ISDN, to decreases of arterial pressure and ejection time.


The place of continuous external negative pressure (CNP) in the management of respiratory distress syndrome of the new born. This work has been carried out on 28 cases of respiratory distress syndrome (R.D.S.), 17 cases of mild and moderate severity were treated by oxygen therapy, excess humidity, and correction of acid-base balance with 100% recovery within an average time of 72 hrs., while 11 cases of severe R.D.S. needed continuous negative external pressure (C.N.P.) in addition to routine management. The use of C.N.P. in spontaneously breathing infants reduced the need for high ambient oxygen, raised PaO2", shortened the duration of therapy; average time of recovery was 48 hrs. In addition, C.N.P. reduced the need for excessive alkali therapy and assisted ventilation. So, in addition to routine therapy, C.N.P. is recommended as an additional line of management of severe cases of R.D.S., i.e. cases that cannot maintain an arterial oxygen of 60 mmHg. at 60% ambient oxygen or above; or cases with frequent apnoeic attacks.


Clinical study on gastric secretion with special reference to pepsin secretion. The stimulating effect of AOC-tetragastrin, caerulein, Histalog and secretin on human gastric acid and pepsin secretion was studied in gastric ulcer patients. The pattern of gastric acid and pepsin secretion after the administration of caerulein was closely resembled to that of gastrin. Slight increase of pepsin secretion after gastrin or caerulein could be based on "wash-out" action caused by the increase of acid secretion after the stimulants. Stimulating effect on gastric pepsin secretion of histalog and secretin would be independent of gastric acid secretion.


Inhibition of gastric secretion by intraduodenal hypertonic glucose in patients with duodenal ulcer. Intraduodenal instillation of hypertonic glucose significantly inhibited tetragastrin-induced gastric acid and pepsin outputs in man. The secretory volume of gastric juice was markedly decreased, whereas, acid concentration remained unchanged. Pepsin concentration, on the contrary, was reduced significantly. The degree of inhibition of pepsin output, therefore, was greater than that of acid output. No significant difference in the extent of inhibition of acid or pepsin output was observed between control subjects and patients with duodenal ulcer.


Experimental colitis in rabbits.

Experimental colitis in rabbits. Experimental colitis was induced in rabbits either by immunizing the antigens which possess the cross-reacting antigenicity with colonic mucosa, and by infusing intravenously their own lymphocytes sensitized with E. coli 014 endotoxin which may contain a high concentration of common antigen (Kunin antigen). The hemorrhagic inflammatory changes were developed in the colon as follows; (1) three of fifteen rabbits immunized with rat colon, (2) one of three rabbits with their own E. coli, (3) six of fifteen rabbits with E. coli 014 and, (4) five of eight rabbits by infusing their own lymphocytes sensitized with E. coli 014 endotoxin. It was suggested that the cross-reacting antigenicity with the colonic mucosa and the sensitized lymphocytes implicate in the pathogenesis of chronic ulcerative colitis.


Double blind study of milk lactose intolerance. One hundred and fifty subjects were studied in a double blind fashion to determine the relationship between lactose malabsorption and milk lactose intolerance. Each participant received 250 ml of a different type of milk on 3 consecutive days. Milk A contained no lactose, milk B had 12.5 g, and milk C contained 37.5 g of lactose. After the experiment was completed each subject was classified with a lactose tolerance test as having "sufficient" or "insufficient" lactase activity. Milk A produced no gastrointestinal symptoms in either sufficient or in insufficient persons. Milk B produced symptoms in 3.8% of sufficient and 37.1% of insufficient individuals, and Milk C induced symptoms in 7.6% of sufficient and 83.5% of insufficient subjects. These differences are very highly significant (P less than 0.0001). It is concluded that lactose-intolerant subjects are indeed milk-intolerant and that the frequency with which symptoms occur in persons with lactose malabsorption increases in direct relation to the lactose content of the milk.


Carcinoma arising in a congenitally dilated biliary tract. Report of a case and review of the literature. A case of carcinoma arising in a congenitally dilated biliary tract is reported. Forty-seven cases in which congenital dilatation of the biliary tract was associated with carcinoma were found in the world literature and analyzed. The association of carcinoma with congenital biliary ductal dilatation was found to be higher than previously recognized. Carcinoma may arise in any cystic portion, extrahepatic or intrahepatic. If technically safe and feasible, primary excision of the choledochal cyst is advisable, to prevent the risk of later malignant change in the unexcised cyst.


Genetics of gastrointestinal polyposis.

Genetics of gastrointestinal polyposis. This review deals with the types of gastrointestinal polyposis in which genetic factors play an essential part, namely, the hamartomatous lesions of Peutz-Jeghers syndrome and multiple juvenile polyposis and the neoplastic tumors of familial polyposis coli and multiple adenomas. The mode of inheritance, associated lesions, malignancy potential, and possible interrelationships between the various types of polyposis are discussed. The knowledge that the lesions are inherited should enable other family members to be investigated and treated at an early stage, a matter of considerable importance in the prevention of cancer when there is an associated risk of gastrointestinal carcinoma.


[Determination of microelements in placenta I. Commun.: spectrophotometric determination of copper content of human placentas (author's transl)]. The copper content of human placenta determined by means of the Bathocuproinemethod lies at 1,21 +/- 0,18 ppm in the fresh and 7,06 +/- 1,04 ppm in the dried material. Furthermore an improved generally applicable method for decomposition of biological materials that prevents the volatilization of trace elements is described.


Gene duplication in Saccharomyces cerevisiae. Five independent duplications of the acid-phosphatase (aphtase) structural gene (acp1) were recovered from chemostat populations of S. cerevisiae that were subject to selection for in vivo hyper-aphtase activity. Two of the duplications arose spontaneously. Three of them were induced by UV. All five of the duplication events involved the transpositioning of the aphtase structural gene, acp1, and all known genes distal to acp1 on the right arm of chromosome II, to the terminus of an arm of other unknown chromosomes. One of the five duplicated regions of the right arm of chromosome II was found to be transmitted mitotically and meiotically with very high fidelity. The other four duplicated regions of the right arm of chromosome II were found to be unstable, being lost at a rate of about 2% per mitosis. However, selection for increased fidelity of mitotic transmission was effective in one of these strains. No tandem duplications of the aphtase structural gene were found.


[Mechanism of the mutagenic action of the decay of incorporated phosphorus-32]. The experimental material concerning that physico-chemical consequences of 32P decay in the molecular structure of DNA, their reparation mechanism as well, and resulting mutagenic effects have been analysed. The reparation of the single-strand break of the DNA chain does not cause the changes of microdeletion and microinsertion type but instead of the changes observed are of the nucleic bases conversion type. It is concluded that the mutations caused by the decay of 32P incorporated appear as a result of errors in the selection of nucleic bases during the reparative replication of the non-conservative type.


[Specific mutagenic effectiveness of 1,4-bis-diazoacetylbutane in relation to individual genes]. A selective effect of 1,4-bis-diazoacetylbutane (DAB) with respect to individual genes is observed when studying its mutagenic action on bacterial strains. Escherichia coli and Salmonella typhimurium. The frequency of mutations to thr+ exceeded in three orders the background of spontaneous variability for this marker. No induced mutations to trp+ and his+ leu+, which might be the result of transition, transversions, suppressor mutations and frame shift mutations, were detected. Mutagenic effect of DAB is due to the functioning of the gene uvr+. Several hypotheses are proposed on possible mechanism of the specific effect of DAB with respect to individual genes.


[Possible interaction mechanisms of allele and nonallele genes on the translation level]. Data on mechanisms of the formation of hybrid (heteropolymeric) isozymes are surveyed. Hybrid isozymes are considered to be the result of the interaction of allelic and some non-allelic genes at the translation level. Evidence is provided indicating that the formation of hybrid isozymes is closely related to the translation process of those mRNAs that synthesize allelic genes. It is suggested that the stage necessary for the formation of hybrid isozymes is compartmentalization (joint location) in the cytoplasm of the mRNAs that are synthesized by allelic genes. This suggestion helps to clarify many experimental data on the mechanisms of the formation of hybrid isozymes in various animal and plant species. One of the conclusions derived from this suggestion is that the compartmentalization of mRNAs of allelic genes creates conditions for an equal-probability quantitative manifestation of allelic genes in the phenotype prior to post-translation.


[Preferred secondary attachment site of prophage phi80 on Escherichia coli K-12 chromosome]. The integration frequency of phage att80 immlambdac1857 into the chromosome of a mutant strain H47 Escherichia coli K-12 deleted for the normal prophage insertion site is found to be about 20-fold decreased as compared with its integration into the wild type strain. The most of the resulting lysogens contain the prophage at the secondary attachment site of the mutant bacterial chromosome which is preferentially utilized for prophage insertion. This attachment site (att80-II) is located close to his-genes on the chromosome of H47 strain. Prophage curing procedure of such abnormal lysogens results in the appearance of rare auxotrophic heat-resistant survivors with the His- phenotype. In some cases the prophage insertion can induce an inversion of a neighbouring genetic region. Such lysogens contain the purC gene near prophage located at the att80-II site, and after curing they segregate the heat-resistant His- and Pur- colonies.


[Mutations of resistance to 2,6-diaminopurine and 6-methylpurine that affect adenine phosphoribosyltransferase in Escherichia coli K-12]. Independently obtained mutations (apt) of resistance to DAP (2,6-diaminopurine) and MP (6-methylpurine), that affect adenine phosphoribosyltransferase (APRT) in Escherichia coli, are different in their effect on the conversion of several substrates of APRT, such as DAP, MP, MAP (6-methylaminopurine) and adenine, to their nucleotide derivatives. Most of mutants were resistant to DAP and MP, unable to utilize MAP (as purine source) and differed in their ability to uptake adenine from the medium. Among the mutants capable to utilize adenine the following types are found: (1) resistant to DAP and MP, but capable of utilizing MAP, and (2) resistant to DAP, capable of utilizing MAP, but sensitive to MP. The gene apt encoding APRT is located between genes proC and purE; the frequency of cotransduction between proC and several apt mutations is found to be 1.7--2% and purE-apt--to be 5--10.8%. Mutations apt block up the ability of purine-dependent (pur) bacteria lacking purine nucleoside phosphorylase (pup) to use purine ribonucleosides as purine sources. The degree of that blocking depends on the ability of apt mutants to convert adenine to AMP via APRT. These observations confirm our previous data, that the ability of pur pup mutants to use purine ribonucleosides depends on the activity of APRT.


[Reparation of the damages induced by UV light in salmonellae]. The survival of Salmonella typhimurium wild type strains after UV-irradiation is studied. It is demonstrated that many of these are more sensitive to UV-irradiation than Escherichia coli of the wild type. Alkaline sucrose density gradient centrifugation has demonstrated a deficiency of these strains in normal excision repair of UV-damaged DNA. This deficiency is not a feature of Salmonella genus, because a strain is found of the same resistance and reparation ability as E. coli wild type strain.


Immunocytochemical study of the interaction of soybean trypsin inhibitor with rat intestinal mucosa. To investigate further the cause of the pancreatic enlargment induced by orally ingested soybean trypsin inhibitor (STI), antibodies raised against STI and purified by affinity chromatography were used to localise dietary STI in the rat gut by fluorescent immunocytochemical methods. This technique permitted the clear intracellular demonstration of STI in the ileal mucosa of suckling rats. However, in adult rats no entry of STI into mucosal cells of the small intestine could be demonstrated, it being confined to the luminal surface of the mucosa. Although the passage of STI into and across the adult intestinal mucosa could not be excluded through the use of this technique, the results are consistent with an intraluminal mode of action of STI as suggested by Green and Lyman (1972)--namely, that the pancreatic enlargement caused in sensitive species results from the inhibition of trypsin (which acts as the physiological inhibitor of the mucosal secretion of pancreotrophic hormones), thus resulting in the uninhibited secretion of these hormones.


Inhibition by somatostatin (growth-hormone release-inhibiting hormone, GH-RIH) of gastric acid and pepsin and G-cell release of gastrin. Somatostatin (cyclic growth-hormone release-inhibiting hormone--GH-RIH) was infused into dogs with gastric fistulae. Somatostatin inhibited gastric acid response to four gastric stimulants--insulin, food, histamine, and pentagastrin. Histamine- and pentagastrin-stimulated pepsins were inhibited similarly to inhibition of acid. Somatostatin inhibited the gastrin response to insulin and food.


Social work in health care: past and future. Historically, social work in hospitals has been subordinate to the medical profession. After tracing its development, the author suggests ways in which hospital-based social work can effectively play a role in the area of policymaking as the equal of other professions in shaping health care decisions and practices.


Effect of oxygen supply on growth of Klebsiella aerogenes in a multistage tower fermentor. The effect of the rate of oxygen supply on biomass growth, consumption of carbon source formation of metabolic by-products, biomass yeilds referred to C-source and oxygen, respiration rate and the respiratory quotient was studied in a multistage tower fermentor with an interstage backflow, i.e. with a continuous reinoculation of the preceding stages. Experiments were done with Klebsiella aerogenes CCM 2318 in a synthetic glucose medium with constant glucose concentration in the feed, at pH 7.0. temperature 30 degrees C, and dilution rates 0.6 and 0.178 h-1 (referred to one stage). Different behavior of the culture was found at different dilution rates both with oxygen and under oxygen limitation. As compared with the chemostat system, the regime with an interstage backflow exhibited differences in respiration rate and CO2 formation; this attests to a considerably different physiological state of the cells.


Apparent half-lives of sugar transport proteins in Saccharomyces cerevisiae. Using incubation in the presence of 0.4 mM cycloheximide the half-lives of the principal membrane transport proteins in baker's yeast were found to be: more than 24 h for the constitutive glucose carrier, 2.2 h for the inducible galactose carrier, 1.2 h for the inducible maltose carrier and 0.8 h for the inducible alpha-methyl-D-glucoside carrier. The distinct nature of the two last-named carriers was thus supported. De-induction of the galactose carrier was enhanced in the presence of glucose plus cycloheximide but not of either substance alone. Chloramphenicol suppressed all effects of cycloheximide. In contrast to the enzymes of galactose metabolism, the induction of the glactose carrier was not under the control of a mitochondrial factor and took place in a rho-mutant. The system induced by maltose but not the one induced by alpha-methyl-D-glucoside was de-induced rapidly by the intervention of a cytoplasm-synthesized protein.


[An intraperitoneally positioned IUD--mistaken for a Spieghel hernia]. A 40-year-old woman presented with the typical signs and symptoms of a Spigelian hernia. Upon operation, an inflammatory conglomerate tumor in the lower omentum was found, containing a copper T. As there were no signs of perforation it is to be discussed whether the IUCD migrated through the right Fallopian tube or penetrated through the uterine wall without leaving a scar.


Immunohistological studies on the distribution of cytochrome b3 reductase in rat liver microsomes. The distribution of cytochrome b5 reductase in rat liver microsomes purified by density gradient centrifugation was studied using anti-cytochrome b5 reductase/anti-ferritin hybrid antibodies labeled with ferritin. Electron micrographs show that the outer surface and the polar cap of tangential sections of essentially all vesicles derived from endoplasmic reticulum are specifically marked with a few ferritin grains which are not localized in large patches but arranged randomly. This finding was correlated with morphometrical and biochemical measurements. The results, supporting our earlier investigations, suggest that cytochrome b5 reductase may be clustered at the most in very small assemblies consisting of a few molecules which, in turn, are statistically uniformly distributed over the total membrane system.


Localization of kallikrein in porcine pancreas and submandibular gland as revealed by the indirect immunofluorescence technique. The glandular kininogenase kallikrein is known to occur in many mammalian organs and glands but direct histochemical localization has been achieved in only a few cases. We have now been able to localize porcine kallikrein in the acinar cells of the pancreas and in the striated and collecting duct cells of the submandibular gland. Incubation of frozen and fixed sections with one of the crossreacting antibodies, anti-pancreatic, anti-submandibular or anti-urinary kallikrein IgG resulted in the same immunofluorescence pattern. There was evidence of a specific fluorescence neither in the acinar cells, nor in the interstitial tissue or blood cells of the submandibular gland nor in the islets of Langerhans, the interlobular ducts or blood vessels of the pancreas. From all data now available about glandular kallikreins, it seems that the kallikreins in these organs are very similar.


Barriers to the delivery of mental health services: the New York City experience. The author discusses some of the barriers encountered in attempting to transform New York City's fragmented mental health services into a comprehensive, nondiscriminatory, and accessible system. Among the barriers he identifies are the belief that more money alone will solve the problem; the uneven distribution of funds among the boroughs of the city and the resistance of existing agencies to redistribution; and the way in which reimbursement patterns shape the kinds of services provided. He believes the single most effective stimulus to the development of an integrated system of care would be a requirement that eligibility for reimbursement under Medicaid be based on a facility's participation in a comprehensive system of care. He emphasizes the need to remove social, rehabilitation, and other services from under the mental health umbrella and to obtain other sources of funding for them; the need for local governance of services; and the need to provide work opportunities for the more seriously disabled.


Ohio congressman has keen grasp of health care issues. A hospital trustee himself, Rep. Willis Gradison Jr. (R-OH) believes that mandatory cost controls would weaken the financial capacity of hospitals, greatly reduce their access to the capital market, and ultimately lead to hospitals' ap,lying to the federal government for direct aid in order to operate. It does not make sense, he says, to put cost controls on hospitals and not on other segments of the economy.


[Bronchopulmonary defense mechanisms (author's transl)]. Bronchopulmonary defense system protects the organism effectively against various inhaled material. This system, including mechanical, biochemical and immunological mechanisms, is reviewed.


Risk factors in early-onset neonatal group b streptococcal infections. Newborn infants with "early-onset" disease due to group B beta hemolytic streptococcus were studied over a 40-month period. Clinical presentations included asymptomatic bacteremia, mild transient illness, respiratory distress, meningitis, and overwhelming sepsis. Chronologically, 18 were ill at birth; 10 became ill after a symptom-free period; and four were asymptomatic. Sixty-six percent of the cases weighted less than 2500 grams, and 56% were born to mothers whose amniotic membranes were ruptured for over 20 hours. All 15 of the deaths occurred in low birth weight infants who were criticially ill from birth. A review of 128 consecutive deliveries of infants weighing under 2000 grams revealed 28 cases with prolonged ruptured membranes, and three of these 28 infants developed group B streptococcal infection. The infant of the colonized gravid woman in premature labor or with prolonged ruptured membranes is clearly at risk, and these results suggest that the management of "early-onset" disease should begin prior to delivery.


Antihypertensive effect of N-amidino-2-(2,6-dichlorophenyl) acetamide hydrochloride. A double-blind cross-over trial versus clonidine. Sixteen patients with essential hypertension were treated with N-Amidino-2-(2,6-dichlorophenyl) acetamide hydrochloride (BS 100--141) and clonidine for five weeks each in a double-blind cross-over trial. Dosage ranged from 2 to 6 mg BS 100--141 and from 0.3 to 0.9 mg clonidine daily in two or three divided doses. Both compounds caused a significant and comparable fall in blood pressure. Patients whose blood pressure was not reduced to normal levels by 2 to 3 mg BS 100--141 daily did not respond better to an increase in the dose. Dry mouth and constipation occurred about equally frequently with both agents, but sedation and orthostatic circulatory effects were considerably more frequent with clonidine. Rebound hypertension likewise occurred in five patients following clonidine withdrawal as opposed to no patient after BS 100-141.


Long-term follow-up study of gastric cancer patients treated with surgery and adjuvant chemotherapy with mitomycin C. A group of 496 cases was used in a controlled trial to study the possible value of mitomycin C as an adjuvant to curative surgery for gastric cancer. Patients assigned to receive the drug were given mitomycin C, 0.8 mg/kg body weight intravenously, twice a week for 5 weeks immediately after surgery. The control group was treated with surgery alone. Sixty-six patients were excluded from the study because of non-curative surgery. There was no over-all difference in survival and cancer death rates at 5 and 10 years between treated and control groups. However, a survival rate 18.6% higher at 5 years was observed in the subset of patients who had moderately advanced lymphatic metastases, and a survival rate 26.4% higher at 5 years was observed in the subset of patients who had involved serosa. The difference in cancer death rate was 14.5 and 24.0% in each subset, respectively. These significant differences persisted at 10 years. The effect of chemotherapy seemed to result from the successful inhibition of peritoneal dissemination and local recurrence. An adverse effect was observed in patients in the early stages cancer. These results suggest that mitomycin C could be useful as an adjuvant to curative surgery for moderately advanced stages of gastric cancer.


Mycobacterium leprae found in epidermal cells by electron microscopy. Leprosy bacilli were found in a keratinocyte of the epidermis by the electron microscopic observation of the ultrathin section of a leproma. The possibility of discharge of leprosy bacilli from the skin should be considered even if the lepromatous patient does not have any ulceration.


Children with terminal illness: a selected review. This brief review consdiers the psychiatric aspect of a child's dying from terminal illness. Much of the literature is largely theoretical, illustrated by case histories and clinical observations. Only recently has research been published based on empirical analyses of grief reactions in the child. There is no corresponding empirical research on the grief reactions of parents and siblings, or of the medical staff that cares for the terminally ill child. A review in this area points out the need for more integration of theoretical, clinical, and empirical work, including all aspects of a dying child's environment.


The influence of early deprivation on regressive behavior in the hospital: a clinical case conference. The purpose of this case report is to describe the evolution of a psychosocial plan of management for an "uncooperative" patient on the inpatient nephrology unit at The New York Hospital. The edited transcript of the weekly multidisciplinary Psychosocial Conference on this unit is presented in order to detail this evolution. The conference was attended by nurses, social workers, psychiatrists, a psychology intern and the patient's primary physician, who all had input into formulating the plan and joint responsibility in effecting it. A brief discussion follows the transcript.


Causes and consequences of circulatory changes in renal transplants. I. Angiographic studies. Selective angiography post mortem and in vivo, respectively, has been performed in canine kidneys (isolated, autografted or left in situ) for the study of the renovascular changes caused by different perfusates and by reperfusion. The results indicate that inadequate heparinization, the composition of the perfusate, imperfect surgical techniques and even restoration of circulation to the kidney itself, may produce roentgenologically demonstrable renovascular damage the causes and consequences of which are unrelated to those of the closely studied and adequately interpreted phenomena of graft rejection.


An exaggerated augmentation of renal calcium excretion after oral glucose ingestion in patients with renal hypercalciuria. The calciuric response to an oral glucose load (100 g) was determined in 16 patients with calcium oxalate urolithiasis (seven with renal hypercalciuria and nine with absorptive hypercalciuria) and seven normal subjects. The rates of renal calcium excretion increased significantly after glucose ingestion in all three groups. The calciuric response in patients with absorptive hypercalciuria and intestinal hyperabsorption of calcium was indistinguishable from that of normal subjects. However, the calcium excretions were significantly higher during 1 hr preceding and 3 hr after glucose ingestion in patients with renal hypercalciuria (with presumed "renal leak" of calcium) than in normal subjects. The increment in the calcium excretion rate was also higher in patients with renal hyperacalciuria, particularly during the 2nd hour of glucose ingestion. The results provide a further support for the concept of different etiologies of renal and absorptive hypercalciurias.


Recurrent aneurysmal bone cysts in children. Discussion on the treatment of three cases. Three children presented with recurrence of aneurysmal bone cyst. In two of these patients the lesion was localized in the superior metaphyses of the tibia and humerus respectively. Total resection was performed followed by the introduction of autoplastic transplants of cortical and spongy bone. In the third case prosthetic substitution of the upper fourth of the ulna was preferred. Healing was obtained in all cases. The indications, operative technique and the final results are discussed.


[The vinyl-chloride disease].

[The vinyl-chloride disease]. Workers engaged in the PVC-production, who were long-term exposed to the gaseous base vinyl chloride exhibit a complex pattern of damages. Changes of the skin, vascular and bone system, as well as thrombocytopenia, liver fibrosis with portal hypertension, disturbances of the porphyrin metabolism and alterations of the central nervous system were observed. Moreover vinyl chloride is oncogenic and may cause angiosarcoma of the liver. By directed occupational medicine supervision, improvement of the production conditions and introduction of new processing techniques health risks at the workplace could be eliminated to a far extend.


[Immunoelectron microscopy in dermatology]. The principle of immunoelectronmicroscopic studies using horseradish perpoxidase is described. This method, especially the peroxidase-antiperoxidase multistep technique, reveals more details about the exact localization of immunophenomena in different dermatological diseases. The results of immunological investigations performed on the ultra-structural level in bullous diseases, lupus erythermatosus, vasculitis, and psoriasis are summarized and compared with the immunofluorescent and classical electromicroscopic findings.


Cardiovascular effects of positive end-expiratory pressure in dogs. Our purpose was to reexamine the relationship of the fall in cardiac output and blood pressure which occurs during positive end-expiratory pressure (PEEP) to changes in transmural right atrial and left atrial filling pressures. Closed-chest dogs, half with pulmonary edema, were studied during spontaneous breathing and inspiratory positive-pressure breathing (IPPB) with 0-15 cmH2O PEEP. Mean esophageal pressure accurately reflected changes in pericardial pressure and was used to estimate extracardiac pressure. We found that cardiac output fell approximately 50% and blood pressure fell 20% during 15 cmH2OPEEP in spite of well maintained transmural right atrial and left atrial (or pulmonary artery wedge) pressures suggesting a primary or reflex depression of atrial or ventricular function.


Fluid leaks from extra-alveolar vessels in living dog lungs. Edema transudation from extra-alveolar vessels was investigated in anesthetized, open-chested dogs. Fluid accumulation at different alveolar and extra-alveolar vascular pressures was assessed by continuous lung weighing and microscopy. The left (experimental) lung was distended with 6% CO2 and air while normal arterial blood gases were maintained by separately ventilating the right lung. Extra-alveolar vessels were isolated by compressing alveolar vessels with alveolar pressures high enough to stop blood flow. Weight increased steadily (edemogenesis) when pulmonary arterial and/or pulmonary venous pressure was 1 cmH2O below this pressure. Because some alveolar vessels at the lung base could have remained open and leaked, extra-alveolar vessels were also separated from alveolar vessels by glass bead embolization sufficient to stop perfusion. Lung weight gains followed selective pulmonary arterial or venous pressure elevations. Electron microscopy demonstrated edema in experimental lobes which was not present in control lobes with undistended extra-alveolar vessels at the same alveolar pressure. Thus pulmonary edema can be caused by fluid leaking from extra-alveolar vessels.


Chloramphenicol for oral treatment of canine urinary tract infections. Chloramphenicol was administered orally for 7 to 14 days to 83 dogs with urinary tract infections. The daily dosage of 99 mg/kg (45 mg/lb) was divided into 3 equal parts and administered at 8-hour intervals. Response to treatment (negative urine culture after treatment) varied from 84% (11 to 13) for infections caused by Staphylococcus aureus to 51% (24 of 47) for those caused by Escherichia coli; 82% (14 of 17) of the infections caused by Streptococcus spp and 63% (7 of 11) of those caused by Proteus mirabilis responded to treatment. These 4 species comprised 88% of the bacteria isolated from the dogs.


Esophageal deviation in four English Bulldogs. Regurgitation, vomiting, and aspiration pneumonia in 4 young male English Bulldogs were attributed to esophageal deviation that was demonstrated by esophageal radiography. A genetic relationship among these dogs was not determined. Exploratory thoractomy, performed in 2 dogs, demonstrated an apparent compression of the esophagus by the left subclavian artery and brachiocephalic artery at the level of the 2nd and 3rd intercostal spaces. This apparent compression correlated with the roentgen location of esophageal deviation. Surgical redirection of the left subclavian artery resulted in immediate and long-lasting remission of clinical signs.


Scanning electron microscopy of skin window cells of normal subjects. With critical-point dried specimens, skin window cells of normal subjects showed a wealth of surface detail with no evidence of underlying nucleus or organells. Cells interpreted as neutrophils were characterized by delicate curved surface folds and variable numbers of fine filopodia; macrophages were larger and usually covered with tightly-packed clusters of knob-like microvilli, their periphery showing many filopodia and broader projections. Some macrophage filopodia took origin from the free surface of the cell and extended outwards to be attached to the coverslip for part of their extent, giving a 'fly-leg' appearance. Filopodial communications between cells were also present. With slow-dried preparations, the cells were flattened and a putative nuclear profile was evident. In these preparations quantitative analysis was made of various cell parameters comparing neutrophils and macrophages. The significance of these features has been discussed in relation to the in vivo inflammatory response as revealed by cell contact with a glass surface. The technique might be useful for studying haematogenous cells in certain disease states.


Kinetic studies of ampicillin action on Escherichia coli and their spheroplasts. Kinetic studies of ampicillin action were made on exponentially growing Escherichia coli and on E. coli-spheroplasts using a range of inhibitory and subinhibitory concentrations of ampicillin. For each concentration, the value (ko--ka) representing the difference in generation rates of ampicillin-free culture (ko) and the generation rate of the culture with ampicillin (ka) was calculated and plotted against ampicillin concentration. A straight line relation was obtained with E. coli cells, its intersection with the abscissa, where (ko--ka) = o, give the concentration of ampicillin which exerts no inhibitory action on the cells (0.25 microgram/ml). When ka was plotted against ampicillin concentration, the relation was also linear. Its intersection with the abscissa gives the minimum lethal concentration of ampicillin on the bacterial cells (1.05 microgram/ml). With E. coli-spheroplasts such plots were non-linear which means that a different order of reaction was involved. This difference is probably due to a different mechanism of ampicillin action as revealed by the electroscanning microscopy.


Plasmid cointegrates of Flac and lambda prophage. Fifteen cointegrates of the plasmid Flac and prophage lambda that had suffered no detectable change in plasmid phenotype were isolated and characterized. The locations of the prophage insertions were determined by genetic analysis of deletion mutants obtained from each cointegrate as survivors of growth at 42 degrees C. In 11 cointegrates, the prophage was inserted between traI and lac, although probably in more than one location; in 3 others, it was on one side or the other of lac; and in 1 it was between lac and pif. Deletions covering all or part of the transfer region, as well as of lac and of pif, were obtained in the course of this analysis. Deletion mutants that had lost all known transfer genes were also oriT, but they retained the capacity to recircularize after transfer. Attempts were made to isolate lambda transducing phages for nearby plasmid genes from the cointegrates, and lambdaptraGD, lambdaptraD, lambdaptraI, and lambdadtraDI phages were obtained.


Identification of a biochemically unique DNA-membrane interaction involving the Escherichia coli origin of replication. DNA-membrane complexes have been obtained from Escherichia coli by using a freeze-thaw lysis procedure that avoids lysozyme and detergents. Complexes made in this manner and containing DNA near the origin of replication are uniquely sensitive to ionic strength, Pronase, and trypsin. There is approximately one such complex per chromosomal origin. The sensitivities suggest that origin-specific binding is mediated by a protein. By using these unique characteristics to distinguish origin-specific complexes from the majority of DNA-membrane binding sites, it was found that the origin-specific binding persists after termination of chromosomal replication.


L-Asparagine auxotrophs of Saccharomyces cerevisiae: genetic and phenotypic characterization. L-Asparagine auxotrophy in Saccharomyces cerevisiae is the result of mutation in each of two unlinked cistrons, ASN1 and ASN2. Mutation in only one of these cistrons yields growth indistinguishable from that of wild-type cells under a variety of nutritional stresses. Relatively high concentrations of L-asparagine are required to permit maximal growth of the auxotrophs, and the amino acid requirement cannot be satisfied by a variety of other amino acids that serve as nitrogen sources for cell growth. Although reversion of the mutations can occur, haploid populations of cells containing only low frequencies of prototrophs can be maintained easily. In diploid cells heteroallelic for certain combinations of alleles of the two genes, mitotic recombination gives rise to prototrophic cells that accumulate to high frequency in populations of the cells.


Isolation and characterization of Saccharomyces cerevisiae mutants deficient in S-adenosylmethionine decarboxylase, spermidine, and spermine. Four mutants were isolated from Saccharomyces cerevisiae that are deficient in S-adenosylmethionine decarboxylase (spe2). All four mutants are chromosomal and fall into a single complementation group tightly linked to arg1. Since one of the mutants contained a temperature-sensitive activity, this complementation group defines the structural gene. Mutants totally lacking enzymic activity did not contain spermidine or spermine and had a greatly increased doubling time when grown in the absence of these two polyamines. Addition of 10(-6) M spermidine or 10(-5) M spermine, but not putrescine or cadaverine, restored the doubling time to that of the wild type. Diploids formed from a cross of two mutants completely deficient in spermidine and spermine were unable to sporulate in the absence of added spermidine or spermine. We obtained evidence that arg1 was not located on any of the 17 known chromosomes, and therefore we postulate that arg1 and spe2 are located on a new 18th chromosome.


Polyamine auxotrophs of Saccharomyces cerevisiae. Strains of yeast have been constructed that are unable to synthesize ornithine and are thereby deficient in polyamine biosynthesis. These strains were used to develop a protocol for isolation of mutants blocked directly in polyamine synthesis. There were seven mutants isolated that lack ornithine decarboxylase activity; these strains exhibited greatly decreased pool levels of putrescine, spermidine, and spermine when grown in the absence of polyamines. Three of the mutants lack S-adenosylmethionine decarboxylase activity; polyamine limitation of a representative mutant resulted in an accumulation of putrescine and a decrease in spermidine and spermine. When the mutants were cultured in the absence of polyamines, a continuously declining growth rate was observed.


Ribosomal DNA magnification in Saccharomyces cerevisiae. Strains monosomic for chromosome I of Saccharomyces cerevisiae contain 25 to 35% fewer rRNA genes than do normal diploid strains. When these strains are repeatedly subcultured, colonies are isolated that have magnified their number of rRNA genes to the diploid amount while remaining monosomic for chromosome I. We have determined the amount of DNA complementary to rRNA in viable haploid spores derived from a magnified monosomic strain. Some of these haploids contained 24 to 48% more rRNA genes than a normal euploid strain. These extra genes may be responsible for the increased number of rRNA genes in the strain monosomic for chromosome I. Genetic analysis of the haploids containing extra rRNA genes suggested that these genes are linked to chromosomal DNA and are heterozygous. They were not closely linked to any centromere and were not located on chromosome I. Furthermore, all the DNA complementary to rRNA in one of these haploid strains with magnified rRNA genes sedimented at a chromosomal molecular weight, consistent with chromosomal linkage. In addition, several new mutations mapping on chromosome I were used to show that ribosomal DNA magnification was not due to a chromosome I duplication.


Ribonucleoprotein particle appearing during sporulation in yeast. During sporulation of Saccharomyces cerevisiae, most strains accumulate an unmethylated 20S RNA. Contrary to previous reports, this sporulation 20S RNA is distinct from the short-lived methylated 20S RNA precursor of 18S rRNA. This RNA species was found in a cytoplasmic 32S ribonucleoprotein particle consisting of one single-stranded 20S RNA molecule and 18 to 20 identical protein subunits of molecular weight 23,000. The ribonucleoprotein particle was resistant to ribonuclease digestion, although purified 20S RNA was ribonuclease sensitive. Both the RNA and the protein of the 32S ribonucleoprotein particle were only synthesized under conditions that induce sporulation. The accumulation of 20S RNA depended on continued protein synthesis but was actinomycin D insensitive, despite a high guanine-plus-cytosine content. Synthesis of 20S RNA stopped when cells were removed from sporulation conditions and placed in growth medium.


New cytoplasmic genetic element that controls 20S RNA synthesis during sporulation in yeast. Under conditions that induce meiosis and sporulation in Saccharomyces cerevisiae, most strains accumulate a 20S RNA, amounting to as much as 15% of the newly synthesized RNA. The ability of cells to accumulate this new RNA species depends on a dominant genetic element that is cytoplasmically inherited, but is distinct from the other cytoplasmic elements that have been previously identified. The ability to synthesize 20S RNA does not depend on mitochondrial DNA, 2-micron DNA, the translational suppressor psi, the genetic element carrying URE3, or double-stranded killer RNA. However, all 20S- strains examined were also nonkillers, although many nonkiller strains were 20S+. This work also shows that 20S RNA accumulating is not essential for sporulation even though it is induced only by conditions that initiate sporulation. Furthermore, strains that are unable to complete meiosis are still capable of producing 20S RNA when placed under the nitrogen starvation conditions that promote sporulation.


Escherichia coli mutants deficient in the production of alkaline phosphatase isozymes. Escherichia coli K-12 mutants showing an altered isozyme pattern of alkaline phosphatase were isolated. Whereas wild-type strains synthesized all three isozymes in a synthetic medium supplemented with Casamino Acids or arginine but synthesized only isozyme 3 in a medium without supplement, the mutant strains synthesized isozyme 1 and a small amount (if any) of isozyme 2, but no isozyme 3, under all growth conditions. The mutation responsible for the altered isozyme pattern, designated iap, was mapped by P1 transduction in the interval between cysC and srl (at about 58.5 min on the E. coli genetic map). It was cotransducible with cysC and srl at frequencies of 0.54 and 0.08, respectively. The order of the genes in this region was srl-iap-cysC-argA-thyA-lysA. Three more independent mutations were also mapped in the same locus. We purified isozymes 1' and 3' from iap and iap+ strains and analyzed the sequences of four amino acids from the amino terminus of each polypeptide. They were Arg-Thr-Pro-Glu (or Gln) in isozyme 1' and Thr-Pro-Glu (or gln)-Met in isozyme 3', which were identical with those of corresponding isozymes produced by the wild-type phoA+ strain (P.M. Kelley, P.A. Neumann, K. Schriefer, F. Cancedda, M.J. Schlesinger, and R.A. Bradshaw, Biochemistry 12:3499-3503, 1973; M.J. Schlesinger, W. Bloch, and P.M. Kelley, p. 333-342, in Isozymes, Academic Press Inc., 1975). These results indicate that the different mobilities of isozymes 1, 2, and 3 are determined by the presence or absence of amino-terminal arginine residues in polypeptides.


Characterization of two types of yeast ribosomal DNA genes. The intragenic organization of ribosomal DNA from a diploid strain of Saccharomyces cerevisiae was analyzed by using recombinant DNA molecules constructed in vitro. Restriction analysis of the yeast ribosomal DNA with the EcoRI restriction enzyme indicated that eight restriction fragments were present in the ribosomal DNA of this strain: X' (1.87 X 10(6) daltons), A (1.77 X 10(6) daltons), B (1.48 X 10(6) daltons), C (1.22 X 10(6) daltons), D (0.39 X 10(6) daltons), E (0.36 X 10(6) daltons), F (0.22 X 10(6) daltons), and G (0.17 X 10(6) daltons). These fragments were distributed between two different types of ribosomal DNA genes, which had the restriction maps: (formula: see text) in which the underlined region shows the repeating unit. The diploid yeast strain contained approximately equal amounts of each of these two types of genes. The analysis of the recombinant DNA molecules also indicated that the yeast ribosomal genes are homogeneous and extensively clustered.


Location of the 5.8S rRNA gene of Saccharomyces cerevisiae. Direct DNA sequence analysis of Saccharomyces cerevisiae ribosomal DNA cloned in an Escherichia coli plasmid revealed part of the structural gene for 5.8S rRNA at one end of a 700-base-pair EcoRI fragment. Taken with the previously established EcoRI restriction map of the ribosomal repeat unit, this sequence establishes that the yeast 5.8S RNA segment is located between the 18S and 28S segments in the 42S rRNA precursor and in the DNA which codes for it.


Cell growth and length distribution in Escherichia coli. The length growth rate of an exponentially growing population of Escherichia coli B/r was calculated from the population length and birth length distributions. Cell elongation took place at a constant rate that doubled at a certain length. This change in rate was responsible for a sudden drop in the frequency of classes of cells longer than that length. Asymmetry in cell partition was able to generate cells both shorter and longer than the expected twofold range, but did not greatly modify the length distribution in between.


Tryptophan biosynthesis in Saccharomyces cerevisiae: control of the flux through the pathway. Enzyme derepression and feedback inhibition of the first enzyme are the regulatory mechanisms demonstrated for the tryptophan pathway in Saccharomyces cerevisiae. The relative contributions of the two mechanisms to the control of the flux through the pathway in vivo were analyzed by (i) measuring feedback inhibition of anthranilate synthase in vivo, (ii) determining the effect of regulatory mutations on the level of the tryptophan pool and the flux through the pathway, and (iii) varying the gene dose of individual enzymes of the pathway at the tetraploid level. We conclude that the flux through the pathway is adjusted to the rate of protein synthesis by means of feedback inhibition of the first enzyme by the end product, tryptophan. The synthesis of the tryptophan enzymes could not be repressed below a basal level by tryptophan supplementation of the media. The enzymes are present in excess. Increasing or lowering the concentration of individual enzymes had no noticeable influencing on the overall flux to tryptophan. The uninhibited capacity of the pathway could be observed both upon relieving feedback inhibition by tryptophan limitation and in feedback-insensitive mutants. It exceeded the rate of consumption of the amino acid on minimal medium by a factor of three. Tryptophan limitation caused derepression of four of the five tryptophan enzymes and, as a consequence, led to a further increase in the capacity of the pathway. However, because of the large reserve capacity of the "repressed" pathway, tryptophan limitation could not be imposed on wild-type cells without resorting to the use of analogs. Our results, therefore, suggest that derepression does not serve as an instrument for the specific regulation of the flux through the tryptophan pathway.