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Carbon-14-labeled 5-hydroxytryptamine (5HT) was administered intraportally to normal and cirrhotic rats, and urine and bile were collected periodically for periods up to 6, and occasionally up to 10 hr. 14C-labeled 5HT metabolites were separated with the use of two-dimensional paper chromatography, and the radioactivity of nine metabolites of 5HT was measured. Cirrhotic rats excreted 14C metabolites into urine in less quantity than did normal rats. In addition, the biliary excretion of 14C-labeled 5HT metabolites was markedly depressed in cirrhotic rats. The preferential occurrence of glucuronide conjugates was demonstrated in both the urine and bile of cirrhotic animals. 14C-labeled 5-hydroxytryptophol conjugates decreased and relabeled 5HT conjugates increased in cirrhotic rats. In normal animals, at least one-third of the 14C-labeled 5HT metabolites excreted into the bile go through the enterohepatic circulation, and a significant proportion of these can be found again in bile after intrajejunal administration of prelabeled bile.

The excretion of methylmalonate and succinate in the urine of rats was studied during deficiency of vitamin B12 induced by feeding a diet deficient in vitamin B12. If the diet was given already to the pregnant rats and continued to the offspring for 7 weeks the excretion of methylmalonate by the litters increased 50—100 fold as compared with the corresponding controls. If the diet was started later, only a slight increase in the excretion of methylmalonate was found. When normal rats were fed 1 g of sodium propionate per day for 2 days there was a slight increase in the excretion of methylmalonate and a marked increase in the excretion of succinate. Methylmalonate and succinate were isolated and determined by silicic acid column and thin layer chromatography and by paper chromatography.

Most strains of Azotobacter , vinelandii form extracellular polysaccharides under different cultural conditions. They are found as capsules or in the form of slime dissolved in the medium. Experiments concerning the chemical composition of such polysaccharides have been described by Kaufman (1960) , Kaufman and Repaske (1963) , and Cohen and Johnstone, 1963 , Cohen and Johnstone, 1964 . Depending on the strain, glucose and rhamnose, glucose and hexuronic acids or glucose with rhamnose, sialic acid, galacturonic acid, mannuronolactone and o-acetyl groups were identified as constituents. The following experiments describe for the first time 2-keto-3-deoxygalactonic acid as a glycosidically bound component of a polysaccharide.

DETERMINATIONS of α-ketoglutaric acid and pyruvic acid in blood, cerebrospinal fluid and urine have been carried out using 2,4-dinitrophenylhydrazone method.1 The keto-acid hydrazones were separated, either by paper electrophoresis or by paper chromatography.

Publisher Summary This chapter focuses on primary structure of soybean leghemoglobin. Leghemoglobin is the only hemoglobin-like protein found in the plant kingdom. Leghemoglobin can be resolved by electrophoresis and ion exchange chromatography on DEAE cellulose into two main components of molecular weight about 17,000, each containing one heme group per molecule. The hydrolysis of the apoprotein by trypsin, chymotrypsin, and thermolysin, purification of the peptide fragments on Dowex and Dowex or by high-voltage electrophoresis and determination of the amino-acid sequences of these peptides have been described. The most striking feature of Lb a is the complete absence of sulfur-containing amino acids. Another characteristic is that it contains only one pair of histidine residues, which is the minimum number expected if they are assumed to be the heme-binding residues identical to those found in vertebrate hemoglobins. Leghemoglobin differs from vertebrate hemoglobins by having no basic center. The polypeptide chains of hemoglobin and myoglobin usually have one heme-binding histidine residue in the middle, in contrast to cytochrome c .

The protein fractions of the middle ear secretions of 22 patients with true serous otitis were studied electrophoretically and immunoelectrophoretically. The total protein of the secretion varied from 0.4 to 10.5g/100cc, mean 4.5g/100cc. The electrophoretic protein pattern of the secretion was mostly similar to that of the serum. The relative albumin content seemed to be a little lower and that of gamma globulin a little higher than in serum. A very small amount or no γM immunoglobulin was present in the secretion, while γA was clearly demonstrable in little more than half of the cases.

Isoenzyme von Serumesterasen wurden zuerst mit Zelluloseazetat und dann mit einem Gradientgel von Polyakrylamid mit zweidimensionaler Elektrophorese bei der Ratte untersucht. Ein neues Band, das eine starke Albuminesteraseaktivitat aufweist und unempfindlich gegen 10−3 M Physostigmin ist, wurde somit gefunden. Von 17 Esterasebandern waren 7 empfindlich auf Physostigmin, und 3 wurden auch durch Iso-OMPA gehemmt, wahrend 284-C-51 gar keinen Effekt zeigte.

1. In 5 cats ligthly anesthetized with chloralose-urethane all chemoreceptor response was abolished by cutting the vagosympathetic trunks including depressor nerves and by embolization of the carotid bodies by lycopodium powder. By means of a pressurized bottle attached to the femoral arteries mean arterial pressure was regulated to three different levels (160, 120 and 80 Torr consecutively) and was kept constant at each of these levels. Transients and steady state values of ventilation were recorded during this stepwise change of blood pressure. The effect on ventilation of severing sinus nerves at constant blood pressure was observed. After severing sinus nerves recording of the effect of blood pressure changes on ventilation was repeated. 2. In this preparation (chemoreceptors denervated, carotid pressoreceptors intact) severing sinus nerves is followed by a diminution of ventilation in the same order of magnitude as described in the preceding papers, even if blood pressure is kept constant. 3. Following stepwise diminution of mean arterial pressure in the chemodenervated cat, ventilation returns to its initial value after a transient increase. This confirms the conclusion of the preceding paper that during steady state no tonic influence of pressoreceptors on ventilation can be observed. 4. The transient increase of ventilation following diminution of blood pressure is less pronounced, but not abolished, after severing the sinus nerves. It is therefore considered to be only partly due to the release of an inhibition by pressoreceptor impulses. The remaining effect must be due to other causes, possibly transient change of cerebral circulation. 5. From this evidence and that from the preceding papers it must be concluded that the steady state decrease of ventilation observed after severing sinus nerves in cats inhaling gas mixtures containing 35 or 99% O2 can not be attributed either to chemoreceptor drive by O2 deficiency or to blood pressure effects on chemo—or pressoreceptors. Effects of CO2 or H+ on chemoreceptors can be excluded as well since in the experiments of this paper all chemoreceptor drive is abolished. It must therefore be concluded that an unknown respiratory drive is depending upon the integrity of the sinus nerves.

Es wurde der Einflus von Losungsmittel, Impragnierung, pH-Wert, Menge der aufgetropften Substanz, Temperatur u. a. auf die chromatographische Lipid-Trennung auf Glasfaser-Papier untersucht. Abschliesend wird die Methode auf naturliche Lipid-Gemische angewendet. Chromatographic Separation of Lipids on Paper from the Glass Fibres The author has studied the effect of solvents, impregnation, pH-value, the quantity of substance taken for separation and the temperature etc. on the chromatographic analysis of lipids on paper made out of glass fibres. The method has been then applied for the separation of mixtures of natural lipids.

This is the third in a series of four papers in which we present the numerical simulations of the application of the voltage clamp technique to excitable cells. In this paper we discuss the problem of voltage clamping a region of a cylindrical cell using microelectrodes for current injection and voltage recording. A recently developed technique (Llinas et al., 1974) of internal application of oil drops to electrically insulate a short length of the postsynaptic region of the squid giant synapse is evaluated by simulation of the voltage clamp of an excitable cylindrical cell of finite length with variable placement of the current and voltage electrodes. Our results show that ENa can be determined quite accurately with feasible oil gap lengths but that the determination of the reversal potential for the synaptic conductance, ES, can be considerably in error. The error in the determination of ES dependp, and especially the membrane resistance at the time the synaptic conductance occurs. It is shown that the application of tetraethylammonium chloride to block the active potassium conductance very significantly reduces the error in the determination of ES. In addition we discuss the effects of cable length and electrode position on the apparent amplitude and time course of the syn aptic conductance change. These results are particularly relevant to the application of the voltage clamp technique to cells with nonsomatic synapses. The method of simulation presented here provides a tool for evaluation of voltage clamp analysis of synaptic transmission for any cell with known membrane parameters and geometry.

In earlier papers the hypothesis was suggested—based upon investigations in blood doners, seniles, and athletes of 40 years of age and older—that individuals with blood group O are altogether a little more “fit” than those with group A [6–8]. The present paper summarizes additional evidence in patients of 75 years of age and older of the Surgical Clinic, in athletes and in soldiers on active service as well as those on universal conscription. The distribution in these groups compared with 694 healthy inhabitants of Sud-Niedersachsen (Control I: A: 44,8%; B: 10,2%; O:39,3%; AB:5,6%) and 81985 persons of Germany (Control II: A: 43,84%; B: 12,34%; O: 38,75%; AB: 5,05%). For statistical evaluation the method of Woolf is used. The results are described in Table 1 and 2. Our hypothesis of the “little more fitness” of blood group O is based on the following facts: 1. Many diseases are more frequent in individuals with blood group A than in individuals with blood group O. 2. The blood group O is predominant among blood doners (n=2000; A: 43,8%; B: 8,3%; O: 43,0%; AB: 4,9%). 3. In healthy seniles of 75 years of age and older the blood group O predominates, too (n=346; A: 34,7%; B: 12,7%; O: 49,1%; AB: 3,5%). 4. In 614 patients of 75 years of age and older in the Surgical Clinic blood group A predominates (A: 48,2%; B: 10,8%; O: 35,3%; AB: 5,8%). The reason for the predominance of blood group A in this sample is the presence, among other diseases, of 201 patients with different malignant neoplasms, 63 with fractures of the femoral neck, and 57 patients with adenoma of the prostate. 5. In a sample of active athletes of 40 years and older was found a predominance of blood group O (n=340; A: 39,4%; B: 11,6%; O: 46,8%; AB: 4,4%). 6. The blood group O also predominates in soldiers on active service (n=484; A: 37,4%; B: 11,6%; O: 45,2%; AB: 5,8%). In conclusion it seems to be likely that under presentday conditions of life selection favours O-individuals.

Since the first detailed description of basophilic granules in nerve cells by Nissl in 1895, there has been constant discussion concerning the chemical structure and the function of this densely staining granular substance, and important new findings have been published in the last ten years. The first part of this paper reviews, therefore, the progress made on the chemistry and electronmicroscopical structure of the Nissl body, followed by a detailed description of the electronmicroscopical structure of interneuronal connexions, the synapses. The last section of the paper is dedicated to the structure and function of the neuroglia, work which has been accumulated since the author published his monograph in 1955. This section also discusses the construction of cerebral capillaries, the problems of intercellular space and the blood-brain barrier.

This paper is a summary describing the results of recording absorption spectra and absorption changes after irradiation of isolated frog and crucian carp retinae mounted in a transparent chamber inside the sample compartment of a spectrophotometer. Detailed descriptions of the experiments will be given in three separate/papers in preparation.

The discovery and characterization of a vibration response in a black lipid bilayer membrane is the topic of this paper. An electrical vibration response is obtained when the membrane is under voltage clamp and a weaker, but significant, response is obtained under current clamp. The effect arises from an induced variation in the membrane capacitance. It is further shown that the capacitance variation arises from a change in the membrane area as the membrane undergoes drumhead vibration. Possible physiological significance in mechanoreception is discussed.

The idea that certain drugs and neurotransmitters produce their effects by combining with specific receptors was first clearly expressed by Langley (1905) on the basis of the selective and localized effect of nicotine on striated muscle fibres. In 1914, Langley published a paper in which the antagonism between ‘curari’ and nicotine was analysed and measured as the ratio by which the nicotine concentration had to be increased in order to produce a standard response in the presence of tubocurarine. It was clear that Langley had in mind the idea of competition between nicotine and curare for the receptor sites and it was surprising that he did not formulatethe theory quantitatively, particularly since Hill, working in Langley's laboratory in 1909, published a mathematical analysis of the action of nicotine on frog muscle giving kinetic and equilibrium equations based on the law of mass action, which could easily have been extended to give an account of competitive antagonism. Barger & Dale (1910) did not favour the idea of specific receptors for sympathomimetic amines.

The O-trimethylsilyl (TMS) quinoxalinols are very useful derivatives for the gas chromatography of α-keto acids because of their high stability and the absence of stereoisomerism and because of the presence of specific, common and abundant fragments in electron impact mass spectra, which allows the low-level detection of whole groups of keto acids by single-ion detection. In this paper, the chromatographic properties of eleven O-TMS-quinoxalinols on OV-1, OV-17 and Dexsil 300 are reported in terms of methylene units. Also by use of methylene units, the chromatographic isotope effect is analyzed in detail for nine perdeutero-TMS derivatives. The effect is explained by the diminished interaction of the deuterated compounds with the unlabelled liquid phase.

Summary The sexual reproduction of the heterothallic Mucoraceae is initiated and controlled by several sex-hormones. In the following paper experiments on the characterisation of Progamones , a special group of sex-hormones, are described. Progamones are substances of relatively high molecular weight which are secreted into the substrate when they induce the production of gamones in isolated (+) or (-) mycelia. According to our experiments the progamones of Mucor mucedo and Blakeslea trispora can be considered effectors which activate the information for gamone synthesis that exists in the genome of the fungi in a repressed state. The effect on progamones on isolated (+) or (-) mycelia is inhibited by actinomycins.

Concentrations of spermidine and spermine in fifteen different tissues of male and female rats aged three months were determined, using amido black as the quantitative reagent, after paper electrophoretic separation of the amines. The changes in the concentrations of these polyamines in relation to age were followed by determinations from six tissues of newborn rats and of male rats aged 1, 3 and 9 months. At the age of three months the largest amounts of the polyamines were found in the liver and the thymus, 900 to 1600 mμmoles of spermidine and 700 to 900 mμmoles of spermine per g wet weight. No great sex differences were observed. In most tissues the molar concentration of spermidine was higher than that of spermine. The spermidine content in every tissue studied decreased with increasing age, the fall being most marked during the first month of life. The spermine content as a rule increased somewhat during the first month and then remained nearly constant or decreased slightly. Consequently, the molar ratio spermidine/spermine was highest immediately after birth, decreasing in the liver, for instance, from 4.52 to 0.84 during 9 months. In the brain, in contrast to the other tissues investigated, it increased from 1.31 to 2.08 during the first 9 months.

This paper reports further observations on microbodies in bean rust sporelings suggesting that the organelles correspond to glyoxysomes in higher plants. However, cytochemical tests for catalase (DAB-technique) gave negative results.

The first part of this paper concerns the influence of nitration; the proposed 64 per cent NO3H/36 per cent AcOH mixture is considered to be the best, particularly with native cellulose of high degree of polymerization ( DP w = 4700 ); nitration to 13·9–14 per cent N is regularly found for a time of contact of 1·5 hr at 2° with the nitration mixture. The weight average mol. wt., the degree of substitution and the polydispersity obtained by GPC in THF have been determined. In the second part of this work, the enzymic degradation by a cellulasic extract of Basidiomycete is followed during 0–48 hr periods on different types of celluloses. After nitration, the residual cellulose is characterized by its mol. wt. and polydispersity. The rate of enzymic modification is discussed and related to the structure of the substrates.

SYNOPSIS The principal measuring methods employed in morphometry, generally known as stereology, allow information on volumes, surface areas, numbers of structures, and many other dimensions to be derived from simple counting operations. Until relatively recently these techniques have found only limited application in biology, although they have been used for many years in the inorganic sciences. With the development of reliable quantitative methods in physiology and biochemistry, however, stereologic techniques are becoming increasingly important and a number of interesting methods have been developed which are both rapid and simple. In this paper a number of practical techniques are presented which have proved useful in light and electron microscopy.

Summary. 1 Valsalva's experiment was carried out on 25 healthy subjects of whom 13 were smokers and 12 non-smokers before and after smoking of 1–3 cigarettes. In twelve of these subjects control experiments without smoking between two successive Valsalva experiments were carried out. 2 Smoking did not as a rule alter the resting heart rate in non-smokers, but increased it on an average for 16 beats/min. in smokers. 3 The total increase or decrease in heart rate during and after the strain was used as a measure of reactivity. It varied in different subjects, some showing no increase in heart rate at all. Occasionally the type of response obtained in a certain subject could be altered. The smoking tends to decrease the reactivity when effective. A significant correlation between heart rate response and alteration in the height of the P and T waves was found. No correlation between P-Q time and reactivity seemed to exist. 4 The mean electrical axis (and changes caused by strain and by smoking) was calculated with the help of the Dieuaide's chart. The strain tends to deflect the axis rightwards. Smoking did not as a rule affect the mean direction of the electrical field. In 5 instances, however, a leftward shift in the axis was noted. There was no correlation between the size of the heart rate reaction and the rightward deflection of the axis during the strain. 5 Certain special electrocardiogratphic findings will be treated in a separate paper.

The effect of tetracycline on developing bones was explored in organotypic tissue culture. Such culture conditions proved to be suitable for certain experiments dealing with the “teratogenic” effect of drugs, and the first part of the paper examines the possibilities, limitations and fallacies of this technique. Embryonic mouse bones cultivated in vitro show rapid incorporation of tetracycline, and after 30 minutes of cultivation a definite fluorescence is seen. The drug is incorporated at least into two fractions: one which is rapidly released after the withdrawal of tetracycline and one which remains in the calcium-containing zones of the bone. Tetracycline in concentrations of the order of 5 μg/ml completely inhibits the elongation of the calcified zone of the bone rudiments and the increase of their total calcium. However, experiments with labeled calcium still show an incorporation in the presence of tetracycline although no cumulative uptake is seen. The results thus indicate the existence of a rapidly incorporated calcium fraction which is independent of tetracycline. The inhibition of calcification is reversible up to some five days of treatment, whereafter a transfer to normal medium does not lead to a recovery, and the mineralization seems to be irreversibly blocked. It is concluded that the results speak in favor of the theory of a direct action of tetracycline on the formations of the bone salts, rather than interference with enzymatic activity dependent on divalent cations.

This paper describes a procedure which optimizes the fitting of a `model' of a protein to an electron density map. The technique seeks to minimize ∫ (Qo−Qm)2dv where Qo is the observed electron density and Qm is a density associated with a model in terms of which the observed densities are interpreted. Qm consists of a Gaussian density centred on each atomic centre, and a floating background level. Interactions due to overlapping densities of neighbouring atoms are allowed for and the model is normally treated as a flexible chain so that bond lengths are conserved during movement. Alternatively, the atoms may be allowed to move independently. Site occupations and atomic radii are also refinable. The calculation is organized in terms of a `molten zone' of up to ten residues, which moves along the chain one residue at a time, linear or non-linear constraints being applied to preserve chain continuity at each end of the zone. Provision is made for the zone to become active or inactive in predetermined regions of the molecule. A difference map (Qo−Qm) is available at the end of the calculation, as is a molecular listing with revised coordinates and dihedral and inter-bond angles. Inter-bond angles may be treated either as constants or as variables, and if variable may be made elastically stiffer than dihedral angles. The procedure is well suited to maps of 2 to 3 A resolution, but is not limited to this range. It has produced convergent shifts exceeding 1.5 A in a map of 2 A resolution, and, except for shifts exceeding 1 A, convergence is essentially complete in one pass. The procedure has, so far, been applied to four proteins.

The present paper reports the isolation of an obligate phototrophic bacterium which belongs to the Rhodospirillum fulvum-group on the basis of its colour, morphology, nutritional requirements and strictly anaerobic nature. p-Aminobenzoic acid was shown to be the only growth factor required.

This paper presents methods for incorporating crystallographic symmetry properties into complex Fourier transforms in a form particularly well suited for use with the Cooley-Tukey fast Fourier transform algorithm. The crystallographic transforms are expressed in terms of a small number of one-dimensional special cases. The algebra presented here has been used to write computer programs for both Fourier syntheses and Fourier inversions. Even for some quite large problems (7000 structure factors and 149000 grid points in the asymmetric unit) the rate-limiting step is output of the answers.

The concentrations of aspartic acid in various regions of the brain of European ground squirrels (Cilellus citellus), sacrificed at different stages of the hibernating cycle, have been estimated by means of two dimensional paper chromatography. On the basis of experimental results obtained the following conclusions have been derived:1. Similar concentrations of aspartic acid where found in different cortical and subcortical areas of the ground squirrel brain.2. In hibernation at rectal temperatures of 5° C, an important decrease of aspartic acid was found in all the regions studied.3. Inversely, arousal from hibernation was associated with an increase of aspartic acid levels, atteining at 35° C the control values in a majority of investigated regions.The possible explanations and significance of the results obtained have been briefly discussed.

This paper is a condensation of our knowledge on the eyes of the Araneae with respect to anatomy and ontogeny. After the addition of new observations, generalizations are allowed at the present state of our knowledge. On the basis of the structure of the eyes a change in a part of the system of the Araneae has to be proposed.

In this paper we extend the simulation of the voltage clamp of a single nerve fiber to a bundle of axons. These simulations included not only the description of the voltage clamp circuit and a single unidimensional cable to represent the preparation in the "node" region of a double sucrose gap used previously but also a series resistance and a shunt pathway. The output of the voltage control amplifier is applied across the membrane plus the series resistance, producing a voltage drop across the series resistance due to the current generated by the membrane in response to a depolarizing voltage step. Since the membrane current has an inward and an outward phase, voltage drops of opposite sign are produced across the series resistance. During the transient current and at all points along an axon, the potential deviation produced by the series resistance is opposite to the deviation produced by the longitudinal gradient. Only at a command potential equal to the sodium equilibrium potential, the membrane potential transiently matches the command potential. For the attempted voltage clamp of an axon, values of series resistance larger than 50 omega-cm2 allowed propagated action potentials in the membrane. In spite of the presence of propagated action potentials at the calbe membrane, the recorded current does not show "notches" and it has a phase of inward current and a phase of outward current. It is concluded that, in a multicellular preparation with series resistance, the recording of a square voltage pulse does not indicate voltage control of the transmembrane potential. The presence of a shunt pathway produces inaccurate values of current density. Neither series or shunt resistance produce "notches" in the current records.

Based on monoecious, diploid plant species, a model is constructed to determine genetic relationship within the seed production of an open-pollinated population, characterized by its rates of self-fertilization, population density and mode of pollen dispersal. Genetic relationship is measured by the coefficient of inbreeding of a seed produced by a mother plant located at a specified place, or by the coefficient of kinship between two seeds, produced from the same mother plant or produced from two different mother plants separated by a certain distance. The influence of the single parameters on these coefficients is demonstrated by some typical examples, which show that dimensionality of the habitat (one- or two-dimensional), as well as, range and type of pollen dispersal, has little influence on the relationship between seed produced from the same mother plant and, on the other hand, emphasize the important role of the rate of self-fertilization and population density. Some remarks on how to apply Wright's concept of neighbourhood to continuous plant populations close this paper.

1. The present paper deals with the chemolithotrophic growth of a Gram-positive hydrogen bacterium strain 11/x which shows the characteristic features of some coryneform bacteria. 2. Like other hydrogen bacteria, the strain 11/x is a facultative chemolithotroph and grows on many organic substrates faster than in a mineral medium under an atmosphere of knallgas+CO2. Fully induced, autotrophically grown cells, subcultured mixotrophically on fructose show additive growth. 3. Cell-free extracts of autotrophically grown cells are able to reduce methylene blue, dichlorophenolindophenol, phenazine methosulphate, menadione, and FMN with hydrogen. Conditions for direct NAD(P) reduction could not be found. 4. Hydrogenase is formed under autotrophic as well as mixotrophic conditions. In the latter case the rate of hydrogenase formation is diminished depending on the organic substrate. Heterotrophically grown cells do not have any detectable hydrogenase activity. For the induction of hydrogenase in those cells a nitrogen source is a prerequisite. 5. The formation of ribulose-1,5-diphosphate carboxylase and phosphoribulokinase seems to be regulated in a way similar to that of hydrogenase: the enzymes could only be detected in autotrophically and mixotrophically grown cells but not in those grown heterotrophically.

Organ cultures of various embryonic tissues and of both benign and malignant tumors have been successfully used in various investigations. The basic aim of this technique is to maintain the architecture, differentiation, and growth of the tissue as similar as possible to the in vivo situation. One of the best-known methods is the Trowell-type organ culture system, in which tissue explants are grown on small pieces of lens paper placed on a grid of steel mesh (Trowell, 1954). Although this type of organ culture system allows growth of the fragment as a whole, it does not permit outgrowth of the cells at the periphery of the primary explant. This weakness is partly overcome in three-dimensional matrix culture systems, which permit both maintenance of primary explants and replication of cells with reproduction of original tissue structures within the pores of the supporting matrix.

Summary In this paper we have summarized the effects of acute lethal injury on the cell. Such injuries are defined as injuries that result in cell death within a relatively short period of time usually minutes or hours. Following death; the cell undergoes necrosis. Ultrastructural and biochemical methods are needed to study pathophysiology. The cell passes through a series of stages numbered 1 through 7. Stages 1 through 4 are reversible while 5 through 7 are irreversible. Injuries resulting in acute cell death and necrosis include direct damage to the cell membrane, for example by antibody and complement or non-penetrating mercurials or interference with mitochondrial energy supply as in ischemia. More complex injuries such as chemical toxicity in vivo probably act through these means. A hypothesis of progression through the stages and the reversibility is discussed.

This paper summarizes the own investigations in ABO blood groups in 2427 propositi with congenital heart diseases. The complete material as well as the several types valvular aortic stenosis (n=242); coarctation of the aorta (n=127); pulmonary valvular stenosis (n=211); patent ductus arteriosus (n=325); atrial septal defect (n=296); ventricular septal defect (n=612); Fallot's tetralogy (n=316) are compared with the distribution of ABO blood groups in a sample of healthy inhabitants of Sud-Niedersachsen (n=694, control I) and 81985 persons of Germany (control II). For statistical evaluation the method of Woolf is used. The relative incidence are not significant in the different proofs that means there are no statistical correlations between ABO blood groups and congenital heart disease.

It is generally accepted that the thymus and the bursa of Fabricius are principal organs of the chicken’s lymphoid system and immune potential. While neonatal thymectomy influences delayed hypersensitivity responses (Warner et al., 1962; Jankovic and Isvaneski, 1963; Jankovic et al., 1965), the extirpation of the bursa at hatching affects antibody production (Click et al., 1956; Mueller et al., 1960). Evidence forthcoming from several laboratories (Szenberg and Warner, 1962; Jankovic and Isvaneski, 1963; Cooper et al., 1965), suggested a dissociation of thymus-dependent and bursa-dependent lymphoid tissue. Correspondingly, the population of small lymphocytes of the splenic white pulp is influenced by the thymus, whereas the number of plasmacellular elements and germinal centers is governed by the functioning of the bursa. In a previous paper (Jankovic et al., 1966), we pointed out the immunological function of the tonsilla caecalis (Basslinger, 1858). The present communication provides data on the correlation between the bursa of Fabricius and the germinal centers in the caecal tonsil and Peyer’s patches.

IN a vast literature on learning and retention there are, surprisingly, no data concerning effects of experimentally controlled hibernation. In contrast, experiments to investigate the effects of hypothermia are increasing. Andjus et al.1 have shown that retention is unimpaired after hypothermia even in animals cooled to near 0° C. On the other hand, initial learning, investigated after recovery from hypothermia, has been most frequently found to be significantly impaired in subjects whose body temperature has been lowered to 0°–5° C, but unaffected in subjects cooled to 13°–32° C1. In general, the longer the time between recovering from hypothermia and the beginning of learning, the smaller was the impairment observed (paper presented by N. Mrosovsky to the third International Symposium on Natural Mammalian Hibernation in Toronto in 1965).

SUMMARY This paper contains a discussion of some recent results obtained with respect to the transmission of inductive information and detectable material from the inductor to the responding ectoderm during primary induction. It may be concluded that the inductive stimulus is capable of operating over a certain distance without cytoplasmic contact. The mechanism of this transmission is unknown, but the findings from various experiments have shown that a transfer of materials from the inductor to the ectoderm does occur during the process of induction. The transmission of inductive information is time-dependent, and this is due, at least in part, to delayed release of the active compounds from the inductor tissue. On the other hand, the reactivity of the responding tissue changes with time, and the type of differentiation initiated by an inductive stimulus is dependent upon the time of its application. Thus different factors have always to be considered when the results obtained from such induction experiments are being interpreted: the amount and the quality of different active components, their release by the inductor tissue, and finally the selective changes in the competence of the responding ectodermal cells.

During investigations of the structural and functional changes of aging chloroplasts in vitro a very interesting phenomenon showed up. At a definite time after plastid isolation their rate of photosynthetic electron transport under saturating conditions differed for blue and red actinic light (Fig. 1). This transient phenomenon, termed the redblue effect, was investigated in more detail (HARNISCHFEGER & GAFFRON 1969, 1970, HARNISCHFEGER 1970) and the scheme of Figure 2 was brought forward as the most likely explanation. It stated that the macroscopic structural changes of aging chloroplasts in vitro have a profound influence on the microscopic properties of pigment arrangement and energy transfer. As accessory and collector pigments become detached from the photosynthetic reaction center due to distortions of the underlying membrane structure, the light energy they collect cannot be utilized any more and promotes destructive side reactions. It was postulated that this leads to reduction of electron transport activity under conditions where normally enzymes and not pigments constitute the limiting factor. The purpose of this paper is to report on the nature of these side reactions.

The present paper summarizes the own investigations in Rh(D)-system in several diseases: Tuberculosis, sarcoidosis, adenoma of the prostate, carcinoma of the prostate, malignant melanoma, acute leukaemia, chromic leukaemia, benign and malignant osteoma, fracture of the femoral neck, cleft lip and cleft palate, dental caries, psoriasis vulgaris, cholelithiasis, nephrolithiasis, pylorospasm, exogeneous allergic asthma, atopic asthma, allergic rhinitis, pollinosis (hay fever), and congenital heart diseases (patent ductus arteriosus Botalli, atrial septal defect, ventricular septal defect, valvular aortic stenosis, coarctation of the aorta, pulmonary valvular stenosis, Fallot's tetralogy). The blood group distribution in these diseases is compared with a sample of healthy inhabitants of Sud-Niedersachsen. For statistical evaluation the method of Woolf is used. The relative incidence of Rh/rh is not statistically significant in most diseases. A significant prevalence of rh has been found only in allergic rhinits (relative incidence Rh/rh 0,467, ϰ2, p∼0,0004) and in pollinosis (relative incidence Rh/rh 0,489, ϰ2, p∼0,002). It seems to be possible that the gene for the rhesus factor is important in the multifactorial system in both diseases.

Steroid monosulfate and disulfate fractions were obtained from human bile by chromatography on Sephadex LH-20. The conjugates in these fractions had the mobility of steroid mono-and disulfates, respectively, in liquid — liquid partition chromatography on Celite, thin-layer chromatography and high-voltage paper electrophoresis. After solvolysis, the steroids were fractionated on silicic acid and analyzed by gas-liquid chromatography and gas chromatography — mass spectrometry. Androsterone, dehydroepiandrosterone, pregnenolone, 5α-pregnane-3α, 20α-diol and 5β-pregnane-3α, 20α-diol were found in the monosulfate fraction and 5a-androstane-3a, 17a-diol, 5α-androstane-3α, 17β-diol, androst-5-ene-3β, 17α-diol, androst-5-ene-3β, 17(3-diol, 5α-pregnane-3α, 20α-diol, and pregnane-3α, 20α-diol and pregn-5-ene-3(3,20a-diol in the disulfate fraction of bile steroids.

This paper aims to review the essential information which has accumulated on the mode of action of drugs on the production and utilization of circulating triglycerides. As is natural, main emphasis is paid to the hypolipidemic agents but a brief mention is made also of oral contraceptives as a representative of those drugs which have adverse hyperglyceridemic effects.

Isolated pieces of seminiferous tubules of adult rats were grown in organ culture for up to 8 weeks in Petri dishes on the surface of nutrient agar. The medium consisted of newborn calf serum, Eagle's minimum essential medium, glutamate and antibiotics. This method allowed observation of the contractions of the seminiferous tubules in the culture. Contractility, light and electron microscopic structure and histochemically demonstrable activities of alkaline phosphatase and ATPase of the tubule walls were studied at 1-week intervals. The contractility and alkaline phosphatase activity were maintained in the tubule wall for 3 weeks, and the activity of ATPase was maintained for 5 weeks. The thin filaments of the myoid cells, which are responsible for the contractility, were seen with the electron microscope in tubules cultured for 5 weeks. The organ culture method described in the present paper seems to be valuable for studies concerning the functioning of the myoid cells of the seminiferous tubules and the possibility that this is regulated by hormones.

After treatment with ethyl methanesulphonate (EMS), a chlorophyll mutant of Nicotiana tabacum var. Samsun has been obtained in M 1 . Spontaneous somatic variations are observed as isolated areas in the pallisade cells, both on heterozygous and on homozygous plants for the semi-dominant tl gene. These variations appear either as single (green or clear), or as twin (green and clear) areas. This paper reports on the distribution of green somatic variations only, on the basis of the foliar level. The observations have been carried out on a clone homozygous for the tl gene. A highly significant correlation is evidenced between the frequency of somatic variations per leaf and/or per million of cells on the one hand and the physiological stage of the plant on the other. A consistent decrease in the number of variation, after a certain foliar level, is correlated to the transition of the shoot apex from the vegetative to the flowering stage. Modifications of the intracellular conditions caused by this transition could prevent the event responsible for the occurrence of somatic variations. It is also suggested that this event can only take place at a given stage of cell differentiation.

Serum, parotid and whole saliva from normal and diseased subjects were analysed by paper and immunoelectrophoresis. The patients were divided into groups according to severity of salivary gland disease. It was observed that the electrophoretic pattern of parotid secretion was specific for each group. With mild disease the cathode migrating proteins exhibit a decrease compared to the normal. With advanced disease (Sjogren's syndrome) the anodal proteins increase as the cathodal proteins decrease. An increase in a beta migrating glycoprotein was observed in diseased samples. Immunoelectrophoretic analysis revealed that whole saliva contains at least five proteins similar to serum proteins: albumin, transferrin, IgM, IgA and IgG. Parotid saliva only exhibited two proteins similar to serum proteins: albumin and IgA. Ten immunogenic proteins are present in parotid secretions when tested with antiparotid saliva serum. An increase in parotid albumin-antialbumin reaction was observed to correlate with the extent of clinical disease in each gland even within an individual, in patients with Sjogren's syndrome or possible Sjogren. It is felt that albumin may be involved in salivary gland disease. The results are discussed in relation to the findings of previous investigators.