bluuebunny/crossref_metadata_2025_split huggingface dataset:
MEASUREMENT OF BLOOD FLOW WITH FREELY DIFFUSIBLE INDICATORS AS INERT GASES, ANTIPYRINE, LABELLED WATER AND RUBIDIUM
Authors: Lassen Niels A. , Larsen Ole Andrée 
Published: October 2009

ABSTRACT
Indicators which freely cross the capillary wall can be used for measurement of tissue blood flow in many different ways. Basically one can distinguish two categories of methods, viz. the ones where the indicator enters the tissue via the inflowing blood and the ones where the indicator is deposited locally in the tissue. The most important methods are briefly described with special emphasis on the theory of blood flow measurement.
PERFUSION OF THE RAT ANTERIOR PITUITARY VIA A CANNULATED PORTAL VESSEL1
Authors: Porter John C. , Mical Renon S. , Ondo Jerome G. , Kamberi Ibrahim A. 
Published: October 2009

ABSTRACT
A procedure is described for exposing parapharyngeally the hypothalamic-hypophysial complex, enabling one to cannulate a pituitary stalk portal vessel, and thereby perfuse the anterior pituitary. When a crude hypothalamic extract is infused into the anterior pituitary via a cannulated portal vessel, LH and FSH release are markedly stimulated, whereas prolactin release is inhibited. The infusion of a cerebrocortical tissue extract has no effect on the release of LH, FSH, or prolactin, showing that the infusion per se does not affect the release of these hormones. The responses of the perfused anterior pituitary to hypothalamic extract are related to the concentration of the extract in the infusate.
IDENTIFICATION OF MAMMALIAN CHROMOSOMES
Authors: Caspersson Torbjörn , Zech Lore 
Published: October 2009

ABSTRACT
Quantitative cytochemistry in the form of microspectrophotometry can be of help in chromosome recognition. In most mammals, among them man, the sensitivity of these methods is, however, not sufficiently high. Fluorometric techniques permit the application of twice as high microscope resolution and many times higher sensitivity in quantitative work, when dealing with substances with suitable fluorescence.
A technique, working with fluorescence microscopy and fluorometry has been developed for the identification of mammalian chromosomes. For instance, in man all 22 autosome pairs and the X- and Y-chromosomes can be recognized. The technique also considerably improves the possibilities of observing and identifying chromosome aberrations of different kinds. The fluorescence of the Y-chromosome can be observed also in interphase nuclei and can thus be of use in the determination of genetic sex.
A considerable number of DNA-reacting fluorescent agents have been tested. The best results have been obtained with quinacrine and quinacrine mustard.
Sorting of chromosomes can in most cases be done visually after photography. More detailed information can be obtained by microfluorometry. Computerized analysis of the fluorescence patterns of the human chromosomes has shown a great statistical significance of the shape of these patterns. This has also led to efforts towards automated sorting of chromosomes.
Several other techniques have recently been developed for chromosome banding, some giving patterns closely resembling the quinacrine patterns. The methods have been applied to many problems of medical genetical interest. They have also been used for analysis of the karyotypes of several other mammals and of somatic cell hybrids. Work on some plant material indicates that some types of heterochromatic regions have characteristic fluorescence properties.
RIBONUCLEOPROTEIN PARTICLES CONTAINING mRNA and pre-mRNA
Authors: Samarina O. P. , Lukanidin E. M. , Georgiev G. P. 
Published: October 2009

ABSTRACT
This paper is a review of the data concerning the nature, structural organization, properties and biological significance of the particles, containing mRNA and pre-mRNA (precursor of mRNA), i. e., (1) nuclear pre-mRNA-containing particles (2) free cytoplasmic mRNP (ribonucleoproteins), or informosomes (3) polysome-bound mRNP. Some new data on the comparison of nuclear and cytoplasmic particles, the nature of poly A-containing structures, involvement of informofers in Adenovirusspecific RNA transfer are presented. The general scheme of mRNA transport from nucleus to cytoplasm is discussed.
THE RELATION OF PROTEIN SYNTHESIS REGULATION AND RNA METABOLISM
Authors: Penman Sheldon , Goldstein Elliott , Reichman Marsha , Singer Robert 
Published: October 2009

ABSTRACT
The mechanism for regulating protein synthesis in mammalian cells appears to be fundamentally different from that in bacteria. The protein synthesis system of bacteria is largely regulated by the supply of a short-lived messenger RNA and thus is controlled at the level of transcription. In contrast, the messenger RNA of mammalian cells is very long-lived and thus does not appear to vary in amount in response to different demands for protein synthesis. There appears to be a fundamental control system operating at the level of the initiation of translation.
The lifetime of messenger RNA in growing HeLa cells is measured directly. There are two components. Forty per cent of the messenger RNA has a half-life of approximately 7 h, while the remaining 60 % has a half-life of from 21 to 24 h. The decay of messenger RNA in actinomycin is somewhat more rapid, but still much slower than the decay of protein synthesis in the presence of the drug. The failure of protein synthesis, caused by actinomycin, appears due to an inhibition of the factor necessary for ribosome association with messenger RNA.
Cells can respond to depressed rates of protein synthesis by producing a factor which promotes the association of ribosomes with messenger RNA. This is demonstrated by inhibiting the initiation of translation at elevated temperatures. The cell response, which corrects the lesion, is inhibited by actinomycin but not by cycloheximide. Incubation in cycloheximide alone apparently induces the factor and makes cellular protein synthesis resistant to high temperature.
The production of a factor stimulating initiation is demonstrated in vitro. Prior incubation of cells in cycloheximide leads to greatly enhanced rates of initiation in extracts obtained from those cells. Since the cell response is inhibited by actinomycin but induced by cycloheximide, it is concluded that the factor promoting initiation may be RNA.
MITOCHONDRIAL PROTEIN SYNTHESIS IN HeLa CELLS
Authors: Attardi Giuseppe , Costantino Paolo , England James , Lederman Muriel , Ojala Deanna , Storrie Brian 
Published: October 2009

ABSTRACT
HeLa cell mitochondrial polysomes, estimated to consist of two to seven 60S monomers, exhibit an unusual resistance to RNase and EDTA, possibly related to the strongly hydrophobic nature of their polypeptide products which makes the nascent chains particularly "sticky". Mitochondria-specific ribosomal and 4S RNA are coded for by mitochondrial DNA (mit-DNA): there is one gene for each ribosomal RNA (rRNA) species and nine genes for 4S RNA on the heavy (H) mit-DNA strand, and three 4S RNA genes on the light (L) strand. The existence of messenger RNA (mRNA) transcribed from mit-DNA is strongly suggested by the occurrence in mitochondria of poly(A) stretches, 60 to 80 residues long, most of which are covalently linked to RNA molecules coded for by mit-DNA. Mitochondrial poly(A) is not a transcription product of mit-DNA.
The in vivo and in vitro products of mitochondrial protein synthesis exhibit by polyacrylamide gel electrophoresis a group of not well resolved components in the molecular weight range from 12 000 to 25 000 daltons, and another group, more abundant, in the range from 40 000 to 55 000 daltons. A strong constraint appears to exist in the pattern of amino acid utilization by HeLa cell mitochondria, with a very low level, if any, of incorporation of the charged polar amino acids, and a predominant utilization of the most hydrophobic ones.
Block of mitochondrial protein synthesis by chloramphenicol for up to four generations of cell growth has no effect on mitochondrial growth and replication, on the rate of mitochondrial nucleic acid synthesis, and on the formation of a functional protein synthesizing apparatus; however, mitochondrial protein synthesis is required for the formation of a functional cytochrome c oxidase.
No significant differences in the rate of mitochondrial protein synthesis per unit of cell mass, nor in the size distribution of the protein products, were found in HeLa cells in different phases of the cell cycle.
OESTROGEN INDUCED SYNTHESIS OF A PROTEIN IN AVIAN LIVER
Authors: Talwar G. P. , Jailkhani B. L. , Narayanan P. R. , Narasimhan Chitra 
Published: October 2009

ABSTRACT
Oestrogens have a dual role. In organisms exposed to the hormone for the first time, they act as differentiating agents directing the division and recruitment of precursor cells to those competent to make hormone dependent products. Data are given for the induction of the synthesis of an egg yolk protein, phosvitin, in immature pullets and roosters. The hormone is also required for the expression of the differentiated function in the committed cells.
The paper also reviews briefly the salient features of the action of oestradiol in the ovariectomized rat uterus. The hormone is recognized by "receptor" proteins present in the cytoplasm. The hormone-receptor complex migrates rapidly to the nucleus. A derepression of RNA synthesis is observed as an early event.
METABOLISM OF SYNTHETIC STEROIDS BY ANIMALS AND MAN
Authors: Fotherby K. 
Published: October 2009

ABSTRACT
The metabolism of naturally occurring oestrogens in humans is outlined and compared with that in other species and with the metabolism of synthetic oestrogens. There is a close similarity in humans between the metabolism of the naturally occurring oestrogens and that of ethynyl-oestradiol with the exception that the latter is less extensively metabolised than the former. With the exception of the baboon, the metabolism of oestrone and oestradiol appears to differ significantly in other species from that of the human. Our knowledge of the metabolism of oestrone and oestradiol and the synthetic oestrogens in the baboon is still meagre and much more information is required before one can ascertain to what extent metabolism in this species can serve as a model for that in humans.
Little information is available concerning the metabolism of synthetic progestogens in species other than man and rabbits. There are many similarities between these two species both in the metabolism of progesterone and of synthetic progestogens related both to 19-nortestosterone and to 17α-hydroxyprogesterone. Insufficient information is available to know how far these similarities extend.
Little is known about the in vitro metabolism of either the synthetic oestrogens or synthetic progestogens. Such information as is available does not suggest that in vitro metabolic studies, with their well-known limitations, are likely to be helpful.
MONITORING SIDE EFFECTS OF CONTRACEPTIVES
Authors: Hill Austin Bradford 
Published: October 2009

ABSTRACT
The problems of identifying and assessing the frequency of adverse reactions to contraceptives are discussed. The ways and means of solving them are critically reviewed, e. g. by clinical trial, by prospective and retrospective inquiry, by monitoring.
Evidence that oral contraceptives can cause thromboembolic diseases is set out. It is based upon five retrospective inquiries conducted in different ways, different places and with reactions of differing severity but nevertheless giving concordant results. The amount of oestrogen in the formulation has been shown to increase the risk. Association has also been shown between oral contraception and cerebral thrombosis and, probably, coronary thrombosis and with hypertension. The actual incidence of all these adverse reactions is difficult to measure accurately but is undoubtedly small with the lower oestrogen formulations.
Retrospective studies have shown no increased neoplasia of the breast or cervix in women using oral contraception. Firm conclusions must await the passage of more years of use.
With other forms of contraception good evidence on the incidence of adverse reactions is generally scanty.
With all forms of contraception there is a need for more monitoring and for carefully conducted investigations arising from it. Observations over more parts of the world and in differing populations are required.
SPECIAL REQUIREMENTS FOR TOXICITY TESTING OF ORAL COMPOUNDS ADMINISTERED CONTINUOUSLY OR CYCLICALLY
Authors: Overbeek G. A. , Hornstra H. W. , van Julsingha E. B. , Mumford J. P. , Zayed I. 
Published: October 2009

ABSTRACT
The authors feel that several reasons exist for considering contraceptives as a special class of drugs, which therefore require special safety studies. Apart from the usual short and long term studies, particular attention should be paid to the reversibility of the induced infertility, and to its possible consequences for subsequent offspring. A possible risk of damage to the foetus is partially outweighed by the low risk of pregnancy during the treatment periods with oral contraceptives. The procedures used in the Organon laboratories are briefly described. Principles on which we base the choice of dose levels and the duration of the various studies are discussed. The paucity of available data from toxicity studies in animals has prevented the presentation of a summary allowing an appraisal of the predictive value of the current methods in toxicology. Nevertheless, a few examples are given which demonstrate the need for more predictive methods. The present lack of knowledge on side effects in humans after prolonged treatment with oral contraceptives has created a feeling of uneasiness. This in its turn has resulted in some excessive regulatory requirements for very long term animal studies. In our opinion, the predictive value of these studies is extremely low because of the inadequacy of the available animal models.
More value can be attached to the monitoring of side effects in humans and efforts in this direction should be increased. The Organon system of monitoring the side effects of its marketed preparations is briefly described. It is not considered feasible to standardize regulatory toxicity requirements for the time being, which should not prevent us from aiming at reasonable, more generally accepted methods of study.
ENZYME INHIBITION BY ANTIBODIES
Authors: Arnon Ruth 
Published: October 2009

ABSTRACT
The interest in the inhibition of enzymes by their specific antibodies stems mainly from the fact that these systems can serve as suitable models in the study of neutralization of biologically active molecules in general. The interaction of enzymes with their specific antibodies generally leads to a reduction in their enzymatic activity. The mechanism of this inhibition is rarely a direct combination of the antibodies with the catalytic site, but is rather due to steric hindrance, namely, barring the access to the active site. In several systems the mechanism of the antibody effect is by conformational changes which it induces on the enzyme. In these cases, the interaction with the antibody may result either in inhibition or in enhancement of the enzymatic activity. In every instance, however, the effect of the antibody is dependent on its narrow specificity, namely, on the regions of the enzyme to which it is directed. The extent of inhibition or enhancement is, therefore, a reflection of the nature and distribution of the various antigenic determinants on the enzyme molecule.
Antibodies specific exclusively to defined regions of an enzyme molecule can be prepared. This has been performed for both lysozyme and staphylococcal nuclease by two procedures: a) Selective separation of the relevant antibodies from the anti-enzyme serum by an immunoadsorbent containing a particular immunologically active fragment of the enzyme, b) The use of an isolated antigenic fragment of the enzyme, or a conjugate of it, for immunization. The antibodies thus prepared, specific toward a unique defined region of the lysozyme molecule (residues 60–83, denoted "loop") recognize the structural conformation of the fragment and are reactive with the intact enzyme molecule. Furthermore, a chemically synthesized loop-like derivative was proved immunologically identical with the natural fragment, and when forming a part of a completely synthetic conjugate, elicited conformation-specific antibodies, reactive with native lysozyme.
These findings are relevant to the topic of an immunological approach to fertility control from two different viewpoints: In the first place they are informative regarding the specific inhibition by antibodies of sperm enzymes which partake in the fertilization process. Secondly, they encourage the synthetic approach for induction of an immune response toward hormones which are crucial in fertilization or implantation.
THE USE OF ANTIBODIES DEVELOPED BY INFERTILE WOMEN TO IDENTIFY RELEVANT ANTIGENS
Authors: Jones Warren R. 
Published: October 2009

ABSTRACT
In the first half of this century several studies demonstrated that temporary infertility may be induced by immunizing women with semen. Isolated examples of acute hypersensitivity reactions to sexual intercourse provide dramatic evidence that natural isoimmunization to semen occurs in man. The afferent immunological pathway in this process can be influenced by adjuvant effects of genital tract infection. This may be important in assessing the significance of antisperm antibodies in infertile women.
In immunological studies of female infertility, the 3 most commonly used tests for humoral antisperm activity are microagglutination, macroagglutination and immobilization (complement dependent cytotoxicity). The sperm microagglutination test detects both antibody and non-antibody activity. The macroagglutination and immobilization tests both detect antibodies but to date the latter has provided the more meaningful results in infertile women.
A prospective study of reproductive patterns in infertility patients indicated a lower subsequent fertility rate and a markedly higher abortion rate in women with antisperm antibodies compared to those without them. However, the association of antisperm antibodies with continuing infertility only reached a statistically significant level in women with a past history of unexplained infertility of at least 3 years' duration. Occlusion (condom) therapy in patients with antisperm antibodies has proved unsuccessful when compared with the natural reproductive patterns in untreated patients.
Immunofluorescence studies are described and correlated with results of other tests for antisperm antibodies in serum and cervical mucus. The results of these and of other studies of naturally occurring antibodies in infertile women have identified antigens of actual or potential relevance to infertility and fertility control. These include (i) intrinsic spermatozoal antigens, (ii) seminal plasma antigens, (iii) blood group antigens, (iv) histocompatibility antigens and (v) nucleoprotein antigens.
VI. EFFECTS OF THE ANTI-ANDROGEN TSAA-291 AND ITS RELATED COMPOUNDS ON THE IN VITRO FORMATION OF 5α-DHT-RECEPTOR COMPLEX IN THE CYTOSOL OF RAT VENTRAL PROSTATES
Authors: Sudo Katsuichiro , Yoshida Keiji , Nakayama Ryo 
Published: October 2009

ABSTRACT
Inhibitory effect of a synthetic steroidal anti-androgen TSAA-291 (16β-ethyl-17β-hydroxy-4-oestren-3-one) on the in vitro formation of 5α-dihydrotestosterone(5α-DHT)-receptor complex was examined. An aliquot of the cytosol from rat ventral prostates was incubated with [3H]5α-DHT in the presence of various amounts of the anti-androgen. By means of dextran-coated charcoal assay and sucrose density-gradient centrifugation analysis, TSAA-291 was demonstrated to inhibit directly, in a competitive manner, the binding of 5α-DHT to a component analogous in its properties to the cytosol androgen receptor. Further, displacing study using a variety of TSAA-291 analogues was undertaken to examine which of the functional groups of TSAA-291 is important for the affinity to the 5α-DHT binding component, and elucidated that 3-hydroxy or 5α-dihydro derivatives of TSAA-291 and others having axial methyl group at C-10 were less potent competitors for [3H]5α-DHT binding than TSAA-291. Furthermore, using other steroids including androgens and anti-androgens, considerable knowledge was obtained about structural requirements for a steroid molecule to displace the bound [3H] 5α-DHT, and this displacing activity of the steroids was discussed in terms of their anti-androgenic activity.
The history of anabolic steroids and a review of clinical experience with anabolic steroids
Authors: Kopera H. 
Published: October 2009

Metabolism is the term employed to embrace the various physical and chemical processes occurring within the tissues upon which the growth and heat production of the body depend and from which the energy for muscular activity, for the maintenance of vital activity and for the maintenance of vital functions is derived (Best & Taylor 1950). The destructive processes by which complex substances are converted by living cells into more simple compounds are called catabolism. Anabolism denotes the constructive processes by which simple substances are converted by living cells into more complex compounds, especially into living matter.
Catabolism and anabolism are part of all metabolic processes, the carbohydrate, fat and protein metabolism. The term anabolic refers only to substances that exert an anabolic effect on protein metabolism and are unlikely to cause adverse androgenic effects. They shift the equilibrium between protein synthesis and degradation in the body as a whole in the direction of synthesis, either by promoting protein synthesis or reducing its breakdown. The protein anabolic effect of anabolic steroids is not restricted to single organs but is the result of stimulated biosynthesis of cellular protein in the whole organism.
Diabetes and Coronary Heart Disease
Authors: Pyörälä Kalevi 
Published: October 2009

Abstract. Clinically manifest coronary heart disease (CHD) is not uncommon in diabetics with insulin-dependent type of the disease below the age of 40, particularly when the duration of diabetes is long.
Clinically manifest CHD is very common in diabetics with maturity-onset, non-insulin-dependent type of the disease, and in this type of diabetes the frequency of CHD shows little or no relation to the duration of diabetes.
Premenopausal female diabetics have a clinically manifest CHD almost as often as male diabetics of the same age - a situation in sharp contrast to that in non-diabetics with large excess of CHD in males.
The incidence of all manifestations of CHD (sudden and non-sudden CHD death, non-fatal myocardial infarction, »silent« myocardial infarction, and angina pectoris) is increased in diabetics as compared to non-diabetics, but the excess of CHD mortality in diabetics is especially marked, being 3 to 4 times higher than in non-diabetics.
The incidence of congestive heart failure is markedly increased in diabetics and this is in part independent of increased occurrence of CHD and hypertension among diabetics. Subclinical abnormalities of left ventricular function are common in diabetics and these abnormalities appear to show some relationship to the metabolic control of diabetes and in insulin-dependent diabetics also to the presence of microangiopathy.
Diabetes is associated with changes in general CHD risk factors to atherogenic direction. These changes include abnormalities in the levels and composition of plasma lipids and lipoproteins and increased frequency of hypertension.
The impact of general risk factors on CHD risk appears to be similar in diabetics and non-diabetics. The major part of the excess CHD in diabetics, however, is not explained by the effect of diabetes on general cardiovascular risk factors, but is due to an independent effect of diabetes itself through mechanisms which are far from solved.