Subjective stress assessment: a new, simple method to determine pilot workload.

Charged with the preparation of an expert opinion concerning psychophysical workload on pilots, the Aviation Psychology Branch of the GAF/IAM studied the "Subjective Stress Assessment" in which 217 Army, Air Force and Navy pilots filled in a standardized questionnaire. This questionnaire included 170 items to force the pilots into rating their on- and off-duty life; the answers of these people (117 jet, 41 multiple-prop, 14 single-engine, and 45 helicopter pilots) were evaluated quantitatively and qualitatively. It may be said--with all reservations towards subjectivity of pilots' opinions---that the pilots' image certainly requires some corrections, in particular as it relates to the ideal and material assessment of the activities of the separate groups of jet, helicopter, and prop pilots. It was the purpose of the study to show that the evaluation of pilots' workload by means of subjective interviews is a valuable method, aside from the assessment of difficulty of tasks by experts, aside from registration and evaluation of certain physiological parameters, and aside from the application of the Second-Task-Method-Registration.


Aeromedical considerations for flight operations from high-elevation airfields.

High-elevation airfields are available to commercial and military aviation. Rapid ascent to locations at high elevations may result in symptoms of altitude sickness in aircrew, support personnel, and passengers. In the United States there are 302 airfields at altitudes in excess of 1,524 m (5,000 ft); in other areas of the world, field elevations can exceed 4,267 m. The symptom complex which may occur at altitude is reviewed and recommendations are offered to prevent, ameliorate, or manage the symptoms.


Any nurse can prevent dehumanization by the CCU experience.

This presentation deals with the Air Force Nurse as a movice assigned to a CCU area and her contributions to patient care as a member of the Air Force Health Care Team. The novice nurse's contributions to the patients care lie in her ability to manage expected behavioral responses to the CCU experience even with a basic working knowledge of normal sinus rhythm and CPR procedure. The expected responses to the CCU expereince discussed are: anxiety, denial, depression, and aggressive sexual behavior. These usual behavioral responses have, at times, been referred to as "a disease of medical progress" or the so-called "intensive care syndrome". The nurse is in a key position to observe the patient's behavioral responses since she spends most of the time with the patient. When these behavioral patterns are considered as part of a normal patterns of adaptation, the nurse can utilize these for effective management of the patient's hospitalization experience as well as an indicator to the patient standpoint in his process of adaptation. It would be wise to mention that the detailed manifestations and primary causes of these behavioral responses should be part of the nurse's working knowledge and can be easily referred to in recent texts on coronary care nursing. The presentation progresses to specific discussion on nursing intervention of the behavioral responses. In summary, the Air Force novice nurse to a CCU area can be an equally contributory member on the Health Care Team if not compelled to place an exaggerated amount of attention on equipment, but focus more on the patient, leaving more technical learning until she becomes more aware of the unit administration and has the opportunity to attend a coronary training course.


Intellegence among persons with Turner's syndrome.

Wechsler intelligence scale IQ distributions from a representative sample of 67 persons with Turner's syndrome are compared with distributions from a control sample of subjects individually matched for age, race, education, and other social characteristics. Among the probands, there is no increased incidence of either severe or moderate retardation, intelligence is similar regardless of karyotype or somatic stigmata, and the characteristic cognitive deficit is similar among both children and young adults.


Light intensity and phototaxis in the house fly: photonegativity in a yellow-eyed mutant.

Y-tube tests of phototactic behavior of house flies (Musca domestica L.) involving wild-type, yellow-eyed, and hybrid individuals were conducted under low (8 ft-candles, 86.1 lux) and high (1600 ft-candles, 17,222.8 lux) light intensities. The Y-tube design utilized either a clear or a dark stem leading to the branches where the photochoice was made. No significant differences were found in the responses of the wild-type and hybrid lines to either light intensity or Y-tube design. Significant differences were recorded for the yellow-eyed individuals only under high light intensities, whereas their behavior under low light conditions was indistinguishable from that of the wild phenotypes. Yellow-eyed flies showed a 68.6% photopositive response when tested in dark-stemmed Y-tubes under 1600 ft-candles intensity as compared to the 86.0% and 83.3% photopositive responses of the wild and hybrid lines, respectively. However, the yellow-eyed flies tested in the clear-stemmed Y-tubes under 1600 ft-candles showed only a 28.7% photopositive response--a clear reversal toward photonegativity. Light-dark adaptation of the highly sensitive yellow-pigmented eye while in the stem of the Y-tube is responsible for this switch toward photonegative behavior.


Causal analysis of academic performance.

Maximum likelihood methods are presented to test for the relations between causes and effects in linear path diagrams, without assuming that estimates of causes are free of error. Causal analysis is illustrated by published data of the Equal Educational Opportunity Survey, which show that American schools do not significantly modify socioeconomic differences in academic performance and that little of the observed racial difference in academic performance is causal. For two races differing by 15 IQ points, the differential if social class were randomized would be only about 3 points. The principle is stressed that a racial effect in a causal system may be environmental and that its etiology can be studied only by analysis of family resemblance in hybrid populations.


Specific anosmia in the laboratory mouse.

As an approach to a general theory of olfaction, different specific anosmia phenotypes characterized by different profiles of odorant sensitivities have been proposed for humans. In the present experiments, male inbred mice were tested for relative odorant sensitivity using a conditioned aversion technique and odors classified as primary or complex for humans. C57BL/6J and C57BL/10J mice appeared to be less sensitive to the primary odorant isovaleric acid than were males of seven other inbred strains (A/J, AKR/J, BALB/cJ,C3HeB/FeJ, DBA/2J, SJL/J, and SWR/J). In comparisons of C57BL/6J and AKR/J strains, the relative insensitivity of C57 to isovaleric acid did not generalize to the musklike primary odor of pentadecalactone or to the complex odor of amyl acetate. The C57BL/6J genotype may provide an animal model of a specific anosmia as characterized among humans.


Behavioral differences among isogenic strains of Drosophila mercatorum.

Mating propensity in eight all-female laboratory lines was measured. The lines are completely isogenic, but each has a different past history. In all cases, mating propensity was significantly lower than in the bisexual controls; in some cases, mating speed was less by a factor of 10. Three of the four lines deriving from the same wild strain are not only different from the parent strain but also different from each other. A highly significant difference exists between two strains recently obtained by selection for parthenogenesis from the same natural population. One strain appears to produce a substance which reduces mating propensity of control females if females from the two strains are reared together in the same vial. As none of the strains was behaviorally selected prior to testing, these behaviors appear to be incidental accompaniments of the very powerful isogenizing effect of the genetic system in these parthenogenetic strains. Indeed, the data show that partial isolation from sexual reproduction can arise wholly by chance. This may have some relevance to theories of species origin which are accompanied by a strong initial founder effect.


Quantitative analysis of orb web patterns in four species of spiders.

The orb webs of the four species Araneus pima (species nova), Araneus diadematus (Clerck), Argiope aurantia (Lucas), and Neoscona domiciliorum (Hentz) built under controlled laboratory conditions were compared and evaluated quantitatively at two different points in the life cycle in regard to size, regularity, shape, and fine structure. Orb webs of two species from one genus can be distinguished, but are more alike than webs from different genera. Mature spiders built highly specific webs, a fact which may play a role in species isolation during courtship. In adults, web measures correlated in size with the spiders' taxon; young spiders' web size measurements corresponded rather to their body weight or leg length. A web's regularity seemed to be closely related to age. Adult and young spiders built oval-shaped webs with eccentric hubs. Mesh width was correlated with leg length at both age levels. Web data support the likelihood of a monophyletic evolution of the four species.


Multivariate and behavior genetic analysis of avoidance of complex visual stimuli and activity in recombinant inbred strains of mice.

Sixty-six mice of 11 genetic stocks (the Bailey recombinant inbred strains CXBD, CXBE, CXBG, CXBH, CXBI, CXBJ, CXBK; their progenitor strains, BALB/cBy and C57BL/6By: and the reciprocal hybrids, B6CF and CB6F) were tested in a two-compartment apparatus and in a shuttlebox, with five measures taken relating to activity and to approaches to novel and complex stimuli. A factor analysis of these measures revealed two factors, the first involving behavior relating to novel stimuli and the second relating to locomotor activity. In a second experiment, 132 mice of the same strains were tested on four of the measures used previously. On the two measures which had high loadings on the first factor and very low loadings on the second, it was possible to determine a strain distribution pattern (SDP), with the same SDP being found for both measures. When confirmed by testing mice from two congenic histocompatibility strains H(w54) and H(w80), we were able to determine that avoidance of novel/complex stimuli (neophobia) is controlled by a gene or genes at chromosomal segments H-24c and H-1b. It was also found that a polygenic model is consistent with behavior measured by the second (activity) factor.


Assortative marriage for cognitive abilities.

One hundred and twenty-three spouse pairs gathered as part of a family study of the genetics of special abilities were examined on a battery of ability tests. Four principal components were interpreted after rotation: Spatial, Verbal, Perceptual Speed, and Memory. In addition, the first factor from a common factor analysis (unrotated) was taken as an estimate of g. Assortive marriage was measured by the spouse correlations on the test and factor scores. Three multiple regression models were designed to determine whether phenotypic convergence during marriage occurs and whether resemblance between spouses in cognitive ability is related to fertility. The following independent variables were partialed out in the models: (1) sex and age; (2) sex, age, and length of marriage; and (3) sex, age, and number of children. Model 1 (age and sex) accounted for part of the correlation between spouses on the spatial tests, the verbal tests and the spatial and general factors. The perceptual speed and memory tests and factors were largely unaffected by partialing out the independent variables. No evidence of phenotypic convergence over years of marriage or of a relationship between fertility and resemblance in abilities was found.


[Clinico-experimental testing for anti-inflammatory activity of external corticosteroids].

Clinical trials of the anti-inflammatory activity of corticosteroids for external use The influence on skin temperature of 4 corticoid-containing formulations and 3 steroid-free bases was tested in 9 subjects in whom no pathological skin changes were present but who were known to be sensitive to metal ions (chromium and nickel). The effect of the preparations on the healthy skin (vasoconstrictive effect) after a duration of action of 2 and 6 h was compared with the effect on skin sites treated subsequently with the contact allergens for a period of 24 h. In the procedure used the trial preparations were allowed to act for 2 and 6 h under occlusive dressing, or for 4 and 8 h, the dressing being removed for 2 h in each case. The allergization produced an increase in temperature at the skin surface which was influenced in various ways by the trial preparations. Whereas no statistically significant differences in the effect of the individual steroid topicals were found the healthy skin, in the evaluatin of the overall anti-inflammatory effect on the pathological skin processes, some distinct differences in effect were found. On comparing the results the following lowing order was obtained for the overall anti-inflammatory effect: 1. Fluprednylidene acetate 0.1% score 4.5, 2. Difluocortolone-valerate 0.1% score 8.5, 3. Fluocortolone trimethylacetate 0.25% + fluocortolone caproate 0.25% score 12, 4. Desoxymethasone 0.1% score 15, The steroid-free bases tested simultaneously did not exhibit clear effects on the temperature in the normal or inflamed skin. The results of the test procedure described are reproducible and can be evaluated by statistical method; the method thus seems appropriate for comparative studies of steroid-containing topicals. The special value in the procedure is the possibility of testing the effect of the preparations directly in a standardised inflammation model which is directly related to use in patients with inflammatory skin diseases, and of establishing in this way in which preparations the anti-inflammatory effect obtained exceeds the general effect common to all steroids.


[Urea : properties, effects, use].

If urea, a physiologic substance, is applied locally, it has a favorable effect on the skin, it keeps the horny layer moist. However, high concentrations might impair the functions of the skin, for urea penetrates easily into the skin, exerts mucolytic and keratolytic effects, changes the keratin structure, and promotes just like dimethylsulfoxide, the permeation and the resorption of active ingredients. Moreover, urea causes a thinning of the epidermis by influencing the epidermal prolifertion. The properties of urea are of considerable interest in dermatotherapy. However, high concentrations of urea should only be applied for long periods of time, and on large surfaces of the skin, for instance in the treatment of dry skin, in the form of cosmetics, under medical supervision.


[Industrial medicine aspects of lesions due to vinyl chloride].

The VC-disease is another example of the constant threat working people are exposed to. A resonable collaboation of all competent bodies will allow to minimize the hazards or to remove them, and thus to "humanize" the working conditions. The VC-disease should be recognized as an occupational disease, the maximal concentration of VC at the working place should be standardized. New chemical products of considerable economic importance such as VC should be examined carefully before being commercialized.


Clinical factors promoting the development of allergic contact dermatitis.

Some clinically recognized factors promoting allergic contact dermatitis include the colour and structure of the skin, disorders affecting blood-vessels, the microclimate, friction and implantation. A survey is given according to the areas of the body which are influenced more or less by one of these factors. The area around an ulcer is especially easily sensitized by many applied chemicals. The part played by the microclimate in sensitization mainly depends on the amount of sweat and the hyperhydration of the skin. Some recent publications concerning friction and implantation are reviewed.


Polymorphism of esterase 11 in Mus musculus, a further esterase locus on chromosome 8.

A further esterase, esterase 11, which exhibits a polymorphism detectable by electrophoresis, has been observed in the house mouse, Mus musculus. In 15 inbred strains and two outbred strains, the ES-11A phenotype has been found, composed of two bands of enzyme activity of greater anodal electrophoretic mobility than the two bands of the ES-11B phenotype found in one inbred strain, one wild stock, and 101 wild mice. In F1 hybrids (IS/Cam X C57BL/Gr), the phenotype shown corresponds to a mixture of the two parental phenotypes. In backcrosses, ES-11 segregates as an autosomal gene, designated Es-11, closely linked to Es-2 and Es-5 on chromosome 8.


Esterases of laboratory-reared and field-collected cotton boll weevils, Anthonomus grandis Boh.: polymorphism of adult esterases and formal genetics of esterase II.

The esterases of the cotton boll weevil were separated by polyacrylamide gel electrophoresis into four major regions. These were named Est I-IV in order of migration from anode to origin. Polymorphism was observed in all regions. The Est II region was shown to consist of no more than two bands (fast and slow). The inheritance of the fast and slow bands of Est II was demonstrated to be controlled by codominant autosomal alleles. Analysis of the gene frequency of the Est II region showed that one field population was consistent with the Hardy-Weinberg law (P = 0.995), while a second field population was not at equilibrium (P less than 0.001).


Adenine phosphoribosyltransferase: a simple spectrophotometric assay and the incidence of mutation in the normal population.

The significance of partial deficiency of erythrocyte adenine phosphoribosyltransferase (APRT), reported in a number of subjects with gout, has been investigated by studying its incidence in 700 normal blood donors. Three clearly deficient subjects were found, an incidence not significantly different from that in patients with abnormalities of urate metabolism. A new assay method for APRT is described in which an erythrocyte lysate is incubated with adenine and phosphoribosylpyrophosphate (PRPP) for a given time; both hemoglobin and adenine nucleotide (AMP) are then precipitated with lanthanum phosphate; the change in absorbance of adenine at 260 nm reflects the extent of its conversion to AMP by APRT.


Nuclear and cytoplasmic genome relationships in the genus Avena: analysis by isoelectric focusing of ribulose biphosphate carboxylase subunits.

Comparisons of the isoelectric points of small and large subunits of ribulose biphosphate carboxylase extracted from a number of diploid, tetraploid, and hexaploid Avena species have been used to obtain information on the nuclear and cytoplasmic genome relationships within the genus. All species tested had small subunits with similar isoelectric points, so their analysis provided no information of taxonomic value. Three types of large subunits could be distinguished by this method, and the distribution of each among the available species provides strong evidence against the involvement of a C genome diploid (such as A. ventricosa) as the maternal parent in the formation of either tetraploid or hexaploid species. One type of large subunit was confined to the perennial tetraploid, A. macrostachya, and its position in the genus and possible origin are discussed. The value of this approach in studying genome relationships within the genus Avena and related genera is assessed.


Control of anthocyanin synthesis by the C locus in maize.

Alleles at the C locus in maize include C, one of the complementary genes required for anthocyanin pigmentation in the aleurone tissue of the mature kernel; C-I, dominant inhibitor of pigmentation; and c, recessive colorless. The recessive colorless alleles can be differentiated into two distinct forms: c-p (p for positive), conditional colored, develops pigment in the light during germination; c-n (n for negative), colorless, fails to develop pigment at any time. Four-point linkage data support the differentiation of c-p (in the alleles derived from either W22 or K55 inbreds) from c-n. Light and germination conditions are both required for anthocyanin synthesis in c-p tissue, but light "induction" and germination "induction" are two separable events inasmuch as the light stimulus can be stored. The ratio between the two major pigments, cyanidin and pelargonidin, is lowered in c-p tissue relative to that in dominant colored (C) tissue for the W22 allele and background but not for the K55 allele and background. Segregation tests reveal that the difference in the cyanidin-to-pelargonidin ratio in the C and the c-p tissue of W22 background is associated with the C locus. Several properties of the C locus, including anomalous allelic functions, stage- and properties of the C locus, including anomalous allelic functions, stage- and condition-dependent anthocyanin synthesis controlled by its multiple allelic series, and tissue-specific function, suggest that C may be a regulatory locus in the control of anthocyanin synthesis in aleurone tissue.


Alcohol dehydrogenase polymorphism in Apis mellifera.

A polymorphic system of ADH isozymes is described in the honeybee Apis mellifera. Three and six different electrophoretic patterns were found, respectively, in drone and worker pupae analysis. The data indicate that the ADH isozymes are controlled by three alleles, Adh-1(1), Adh-1(2), and Adh-1(3). The frequency of the Adh-1 alleles is different in two analyzed subspecies, Apis mellifera adansonii (African bees) and Apis mellifera ligustica (Italian bees). In the African bees, the frequencies are 0.256 and 0.697 for Adh-1(1) and Adh-1(2), respectively. In the Italian bees, these values are shown to be 0.902 and 0.098, respectively. The allele Adh-1(3) was not detected in the Italian bee population. The effect of NAD on the resolution of this system was investigated, and only one region of ADH activity was obtained in drone pupae analysis when NAD was used in the gels. However, two different regions of activity were observed in the same samples, in the absence of the coenzyme. ADH activity was not detected in young larvae, but it increased to a maximum in prepupal and white-eyed pupal phases. It then declined progressively to total absence in the emerging bees.


Genetic control and racial variation of beta-glucosidase isozymes in maize (Zea mays L.)

beta-Glucosidase (beta-D-glucoside glucohydrolase, E.C. 3.2.1.21, beta-Glu) isozyme variants were studied in a large number of inbred lines, crosses, and races of maize (Zea mays L.). The pattern of Mendelian inheritance demonstrated for beta-GLU variants indicated that they are under nuclear gene control. Twenty-two allelic forms at a single locus were identified in the materials studied by starch gel electrophoresis. Genetic data indicate that beta-GLU in maize is functionally a dimer. Variation of beta-GLU isozymes in 51 racial collections of maize from Mexico showed little correlation with morphological or geographical data. In 39 collections from Central America, variation patterns appeared to have some association with altitude.


Argininosuccinate synthetase activity in cultured human lymphocytes.

The activity of argininosuccinate synthetase (E.C. 6.3.4.5), a urea cycle enzyme, was measured in cultured human lymphocytes using a new radioactive assay. Control cells had a maximum specific activity of 15.7 +/- 8.7 nmoles per hour per milligram of protein and an apparent Km for citrulline of 2 X 10(-4) M, whereas cells derived from a patient with citrullinemia had no detectable activity. A nutritional variant, selected out of the citrullinemic lymphocyte population by ability to grow in citrulline, had a maximum specific activity of 10.7 +/- 3.8 nmoles/hr/mg and an apparent Km for citrulline of 2 X 10(-2) M. These measurements confirm the observation that citrullinemia is associated with a defect in argininosuccinate synthetase activity and provide further evidence that citrullinemia is expressed in cultured lymphocytes. The emergence of a nutritional variant with a partial defect in argininosuccinate synthetase enzyme suggests that this citrullinemic patient has a heterogeneous population of cells, some totally defective and others only partially defective in argininosuccinate synthetase. The new activity assay is described in detail.


Regulation of mammalian protein synthesis in vivo. Stimulated protein synthesis in liver in vivo after cycloheximide treatment.

Protein synthesis in rat liver in vivo was measured between 0 and 72 h after administration of a non-lethal dose of cycloheximide. There was a period of inhibition of [3H]leucine incorporation into both intra- and extra-cellular proteins at 2 h after administration of the drug, which was followed by a recovery phase in which amino acid incorporation varied significantly among the various proteins evaluated. At 12 h there was a marked stimulation of incorporation into nascent polypeptides released from polyribosomes and plasma fibrinogen, but incorporation into ribosomal proteins as well as albumin was still inhibited. Between 12 and 48 h, nascent-polypeptide synthesis remained elevated, but ribosomal-protein synthesis recovered slowly from the inhibition to normal rates only, and plasma-albumin synthesis increased slowly to above control values up to 48 h before returning to normal. A differential pattern of incorporation was also observed for incorporation into free and membrane-bound polyribosomes.


The effects of hyperphenylalaninaemia on the concentrations of aminoacyl-transfer ribonucleic acid in vivo. A mechanism for the inhibition of neural protein synthesis by phenylalanine.

An acute administration of phenylalanine to neonatal animals has been reported to result in large decreases in the intracellular concentrations of several essential amino acids in neural tissue, as well as an inhibition of neural protein synthesis. The present report evaluates the effects of the loss of amino acids on the concentrations of aminoacyl-tRNA in vivo, with the view that an alteration in the concentrations of specific aminoacyl-tRNA molecules could be the rate-limiting step in brain protein metabolism during hyperphenylalaninaemia. tRNA was isolated from saline- and phenylalanine-injected mice 30-45 min after injection, by using a procedure designed to maintain the concentrations of aminoacyl-tRNA present in vivo. Periodate oxidation of the non-acylated tRNA and aminoacylation with radioactively labelled amino acids was used to determine the proportion of tRNA that was present in vivo as aminoacyl-tRNA. Although decreases in the intracellular concentrations of alanine, lysine and leucine were observed after phenylalanine administration, the concentrations of alanyl-tRNA, lysyl-tRNA and leucyl-tRNA actually increased by 15%. Although tryptophan has been suggested to be rate-limiting during hyperphenylalaninaemia, the proportion of tryptophan tRNA that was acylated was maximal in both normal and hyperphenylalaninaemic animals. This unexpected increase in aminoacyl-tRNA concentration is discussed as perhaps a secondary effect resulting from the phenylalanine-induced inhibition of protein synthesis. In contrast, the proportion of methionine tRNA that was acylated in vivo after phenylalanine administration was demonstrated to be decreased by approx. 17%. When the isoaccepting species of methionine tRNA were separated by reverse-phase column chromatography, three species were separated, one of which was demonstrated to be the initiator species, tRNAfMet, by the selective aminoacylation and formylation with Escherichia coli enzymes. After the administration of phenylalanine, the acylation of each of the three methionine tRNA species was decreased, with the initiator species being lowered by 10%. This effect on aminoacylation of tRNAfMet may be the primary step by which phenylalanine affects neural protein synthesis, and this is consistent with previous reports that re-initiation may be inhibited during hyperphenylalaninaemia.


Steroid glucuronyltransferases of rat liver. Properties of oestrone and testosterone glucuronyltransferases and the effect of ovariectomy, castration and administration of steroids on the enzymes.

1. Microsomal preparations from rat liver, kidney and intestine were tested for UDP-glucuronyltransferase activity by using oestrone, oestradiol-17 beta, oestriol, testosterone, cortisol, cortisone, corticosterone, aldosterone, tetrahydrocortisol and tetrahydrocortisone as substrates. The microsomal preparation from the liver glucuronidated oestrone, oestradiol-17 beta and testosterone. 2. The specific activity of the enzyme was significantly higher in livers from female rats than in those from male rats. 3. Testosterone was actively glucuronidated by both sexes. Cortisol, cortisone, corticosterone, aldosterone, tetrahydrocortisol and tetrahydrocortisone were not glucuronidated by any of the three tissues. 4. The non-ionic detergent Lubrol WX activates liver microsomal UDP-glucuronyltransferase 2-3-fold with oestrone and testosterone as substrates. 5. Oestrone glucuronyltransferase was inhibited by oestradiol-17 beta, predominantly competitively and by testosterone non-competitively. Bilirubin was a non-competitive inhibitor of oestrone glucuronidation. p-Nitrophenol had no effect. 6. Oestrone glucuronyltransferase could not be stimulated by either acute or prolonged treatment of animals with phenobarbital, whereas a single dose of 3-methylcholanthrene led to a moderate stimulation. 7. Ovariectomy leads to a 56% decrease in oestrone glucuronyltransferase activity; administration of oestradiol-17 beta induces the enzyme to normal activity after 12 days, and after 15 days the activity is twice the control value. Actinomycin D and cycloheximide block the oestradiol-17 beta-induced increase in enzyme activity. 8. Castration has no effect on the activity of testosterone glucuronyltransferase, nor does administration of testosterone influence enzyme activity. The results provide strong evidence for the existence of multiple steroid glucuronyltransferases in the liver of the rat.


Effect of acetoacetate on glucose metabolism in the soleus and extensor digitorum longus muscles of the rat.

1. The effect of acetoacetate on glucose metabolism was compared in the soleus, a slow-twitch red muscle, and the extensor digitorum longus, a muscle composed of 50% fast-twitch red and 50% white fibres. 2. When incubated for 2h in a medium containing 5 mM-glucose and 0.1 unit of insulin/ml, rates of glucose uptake, lactate release and glucose oxidation in the soleus were 19.6, 18.6 and 1.47 micronmol/h per g respectively. Acetoacetate (1.7 mM) diminished all three rates by 25-50%; however, it increased glucose conversion into glycogen. In addition, it caused increases in tissue glucose, glucose 6-phosphate and fructose 6-phosphate, suggesting inhibition of phosphofructokinase. The concentrations of citrate, an inhibitor of phosphofructokinase, and of malate were also increased. 3. Rates of glucose uptake and lactate release in the extensor digitorum longus were 50-80% of those in the soleus. Acetoacetate caused moderate increases in tissue glucose 6-phosphate and possibly citrate, but it did not decrease glucose uptake or lactate release. 4. The rate of glycolysis in the soleus was approximately five times that previously observed in the perfused rat hindquarter, a muscle preparation in which acetoacetate inhibits glucose oxidation, but does not alter glucose uptake or glycolysis. A similar rate of glycolysis was observed when the soleus was incubated with a glucose-free medium. Under these conditions, tissue malate and the lactate/pyruvate ratio in the medium were decreased, and acetoacetate did not decrease lactate release or increase tissue citrate or glucose 6-phosphate. An intermediate rate of glycolysis, which was not decreased by acetoacetate, was observed when the soleus was incubated with glucose, but not insulin. 5. The data suggest that acetoacetate glucose inhibits uptake and glycolysis in red muscle under conditions that resemble mild to moderate exercise. They also suggest that the accumulation of citrate in these circumstances is linked to the rate of glycolysis, possibly through the generation of cytosolic NADH and malate formation.


The mechanism of adenosine triphosphate depletion in the liver after a load of fructose. A kinetic study of liver adenylate deaminase.

1. The hepatic concentration of several nucleotides and metabolites was measured during the first few minutes after an intravenous load of fructose to mice. The first changes, observed at 30s, were a decrease in the concentration of Pi and a simultaneous accumulation of fructose 1-phosphate. The decrease in the concentrations of ATP and GTP proceeded more slowly. An increase in the concentration of IMP was detected only after 1 min and could therefore not be considered to be the cause of the accumulation of fructose 1-phosphate. 2. To explain the temporary burst of adenine nucleotide breakdown that occurs after a load of fructose, the kinetics of AMP deaminase (EC 3.5.4.6) from rat liver were reinvestigated at physiological (0.2 mM) concentration of substrate. For this purpose, a new radiochemical-assay procedure was developed. At 0.2mM-AMP a low activity could be measured, which was more than 90% inhibited by 5mM-Pi. ATP (3MM) increased the enzyme activity over 200-fold. Pi alone did not influence the ATP-activated enzyme, but 0.5mM-GTP caused a 60% inhibition. The combined effect of both inhibitors at their physiological concentrations reached 95%. 3. It is proposed that the rapid degradation of adenine nucleotides that occurs after a load of fructose is caused by a decrease in the concentration of both inhibitors, Pi and GTP, soon counteracted by the decrease in the concentration of ATP. 4. Some of the kinetic parameters of liver AMP deaminase were computed in terms of the concerted transition theory of Monod, Wyman & Changeux (1965) (J. Mol. Biol. 12, 88-118).


Metabolism of glucose, fructose and lactate in vivo in chronically cannulated foetuses and in suckling lambs.

1. Chronically cannulated sheep foetuses and suckling lambs were injected with 14C-labelled glucose, fructose or lactate, and sequential blood samples taken under conditions of minimal stress and without anaesthesia. 2. Gluconeogenesis from lactate was not detectable in foetal sheep, but the pathway was active in suckling lambs. 3. Fructose utilization rates were low in foetal sheep, with no measurable conversion into glucose or lactate. 4. The high rates of irreversible loss of both glucose and lactate in the foetus were decreased in suckling lambs. Radioactivity from labelled glucose entered both the lactate and fructose pools in foetal sheep, and entered the lactate pool in suckling lambs. 5. A model is proposed in which carbon flow between glucose, fructose and lactate has been quantified in foetal sheep.


Rates of glucose utilization and glucogenesis in rats in the basal state induced by halothane anaesthesia.

1. Rates and rate coefficients of glucose utilization and replacement were determined with [5-3H]- and [U-14C]-glucose in rats starved for 24h, either conscious or under halothane anaesthesia, in a thermoneutral environment. Plasma insulin concentrations were also measured. 2. Halothane anaesthesia decreased the turnover rate by 20%, which was similar to previously reported decreases in metabolic rates caused by natural sleep. 3. Fractional recycling of glucose carbon was little affected by halothane. 4. Comparison of values in one rat with those in another, among both conscious rats and those under halothane anaesthesia, showed that rate coefficients were inversely correlated with plasma glucose concentrations. 5. These findings indicated that halothane, in the concentration used (1.25%, v/v), had little specific effect on glucose metabolism. 6. Although equilibrium plasma glucose concentrations in different rats under halothane were widely different (4-8 mmol/l) the rates of utilization were very similar (2.5-3.1 micronmol/min per 100 g), indicating that these rates were determined by the production of glucose from gluconeogenic precursors released by basal metabolism, the rate of which is necessarily similar in different rats. 7. Among rats under halothane anaesthesia plasma insulin concentrations were negatively correlated with rate coefficients, showing that the differences between rate coefficients were mostly accounted for by differences between rats in tissue sensitivities to insulin. Thus in each 24h-starved rat, sleeping or resting, the main regulators of the plasma glucose concentrations were the rate of supply of gluconeogenic substrates from energy metabolism and the intrinsic sensitivity of the tissues to insulin. 8. We found that a commonly used deionization method of purifying glucose for determination of its specific radioactivity was inadequate.


Glucose turnover in the post-absorptive rat and the effects of halothane anaesthesia.

1. Rates and rate coefficients of glucose utilization and replacement in post-absorptive rats, either conscious or under halothane anaesthesia, were determined in a thermoneutral environment by using [5-3H]- and [U-14C]glucose. Label was not injected into rats under halothane until about 0.5h after anaesthesia was initiated. 2. Comparison with the results for 24h-starved rats in the preceding paper [Heath et al. (1977) Biochem. J. 162, 643-651] showed that insulin concentrations were considerably higher but rate coefficients for glucose utilization were little altered in post-absorptive rats. Sensitivity to insulin was thus considerably increased by a 24h period of starvation in the rat. 3. Fractional recycling of glucose carbon in post-absorptive rats was under one-half of that in starved rats, reflecting the larger contribution of liver glycogenolysis to glucose production in the former. 4. In post-absorptive rats halothane decreased the mean rate of glucose utilization by about 17%. This decrease was associated with an increase in mean plasma insulin concentration, showing that halothane decreased sensitivity to insulin. 5. Recycling was slightly increased by halothane, indicating that the contribution of liver glycogen to the total glucogenic rate was decreased, probably because liver glycogen concentration were about 40% lower throughout the rate determinations in halothane. 6. Comparison of our results with earlier work shows that during and shortly after induction of halothane anaesthesia glucose turnover must have been greatly increased whereas from about 0.5h after induction it was decreased.


Binding of bile acids by 100 000g supernatants from rat liver.

1. The binding of glycocholic acid, chenodeoxycholic acid and lithocholic acid to rat liver 1000 000g supernatants was studied by equilibrium dialysis. 2. The binding characteristics of the bile acids suggest that the binding components are involved in bile acid transport. 3. When mixtures of [14C]lithocholic acid and liver supernatants were eluted from columns of Sephadex G-75, a prominent peak of [14C]lithocholic acid appeared with proteins of mol.wt. approx. 40000. A second, smaller, peak of [14C]lithocholic acid was eluted with proteins of mol.wt. approx. 100000. 4. The inclusion of cholic acid, glycocholic acid or chenodeoxycholic acid in the eluting buffer decreased the amount of [14C]lithocholic acid that was eluted with the higher-molecular-weight component.


Evolution of enzyme catalytic power. Characteristics of optimal catalysis evaluated for the simplest plausible kinetic model.

1. Evolutionary changes in the structure of an enzyme that provide an increase in its K(m) value are considered. Provided that K(m) increases as a result of increases in the forward rate constants of the catalysis relative to the reverse rate constants, the enzyme catalyses the conversion of a fixed concentration of its substrate more rapidly when its structure provides that K(m)>[S] than when K(m)<[S]. 2. Catalytic efficiency of enzymes is discussed in terms of the simplest plausible model, the Haldane [(1930) Enzymes, Longmans, London] reversible three-step model: [Formula: see text] The rate equation for the forward reaction of this model (formation of P) may be written in the simple form: [Formula: see text] K(eq.) is the equilibrium constant (=[P](eq.)/[S](eq.)), and k(cat.)=V/[E](T), where [E](T) is the total enzyme concentration. 3. To assess the effectiveness of an enzyme, it is necessary only to determine the extent to which the constraints of a particular kinetic mechanism permit v(2) (v when K(m)>>[S]) to approach v(d) (the diffusion-limited rate). 4. The value of the optimal rate of catalysis (v(opt.), the maximal value of v(2)) is dictated by the equilibrium constant for the reaction, K(eq.); v(2)=v(d)/a, where [Formula: see text] when k(+1) is assumed equal to k(-3), and v(opt.)=v(d)/a(min.). When K(eq.)>/=1, it is necessary that k(+2)>>k(-1) for a to take its minimum value, a(min.); when K(eq.)<<1, it is necessary only that k(+2)>>K(eq.).k(-1), i.e. a can equal a(min.) even if k(+2)<k(-1). When K(eq.)>>1, v(opt.)=v(d); when K(eq.)=1, v(opt.)=v(d)/2, and when K(eq.)<<1, v(opt.)=K(eq.).v(d). 5. The analysis, together with predicted effects of evolutionary pressure, suggests that in practice the rates of the fastest enzyme-catalysed freely reversible reactions might be expected to be lower than the value of k(+1)[E](T)[S] by about an order of magnitude, particularly if K(eq.)<1. 6. The existing literature suggests that, in general, appropriate values of K(m) have evolved for the provision of high rates of catalysis but that many values of k(cat.) are not large enough to provide optimal rates of catalysis unless the value of k(+1)in vivo is lower than its value in free solution.


Analysis of nucleosomal deoxyribonucleic acid in a higher plant.

Comparisons of nuclease digestions of chromatin in nuclei from rye embryos and rat liver show that their nucleosomal DNA is similar, i.e. DNA subunits consist of 200 base-pair repeats with 140 base-pair cores of identical substructure. The identical nucleosome structure is present in nuclei from cells of rye embryos that have been non-viable (i.e. dead) for more than 7 years. These findings indicate a high degree of stability of the DNA-histone complex and are consistent with conservation of the nucleosomal structure of chromatin during evolution.


The proteoglycan content and the axial periodicity of collagen in tendon.

The glycosaminoglycan content and the axial periodicity of collagen was determined in various regions of the rabbit flexor digitorum profundus tendon. This tendon, which passes from the calf to the toes round the inner side of the ankle, contains a thickened sesamoid-like pad where it is subjected to friction and pressure. Other regions of the tendon are subject only to longitudinal tension. In tensional areas the axial periodicity of collagen was of the order of 62 nm and the tissue contained less than 0.2% proteoglycan on a dry weight basis. In the sesamoid-like region, however, the axial periodicity was a significant 13-15% less, and the proteoglycan constituted about 3.5% of the dry weight. Also, in the tensional areas the predominant glycosaminoglycan was dermatan sulphate, whereas in the sesamoid the predominant glycosaminoglycan was chondroitin sulphate. The possible interrelationships between collagen axial peroidicity and proteoglycan content in this tissue are discussed.


The interaction of chromophoric nucleotides with subfragment 1 of myosin.

The interaction of a series of chromophoric nucleotides derived from 6-mercapto-9-beta-ribofuranosylpurine (thioinosine, thiol) and 2-amino-6-mercapto-9-beta-ribofuranosyl-purine (thioguanosine, thioG) with myosin subfragment 1 isolated from rabbit skeletal muscle was investigated kinetically and spectroscopically. The Mg2+-dependent hydrolyses of thioITP and thioGTP are catalysed by subfragment 1 and probably proceed by a similar mechanism as for ATP hydrolysis, although with different rate constants. For example, the binary thioGDP-protein complex only comprises 8% of the steady-state intermediate of the thioGTPase at 5 degrees C and pH 6.5. Long-lived analogues of intermediates of the thioGTPase were generated by using thioGTP(gammaS) [thioguanosine 5'-(3-thio)-triphosphate], thioGMP-P(NH)P (5'-thioguanylylimidodiphosphate) and thioGDP. The near-u.v. spectra of the thioguanosine nucleotides bound to subfragment 1 were measured and showed that in all cases the purine ring is bound to the protein in a hydrophobic environment, although the pK of the purine thiol group only increases by 0.2-0.3. ThioGTP caused glycerinated rabbit psoas muscle to contract, but in contrast with thioITP was not able to relax muscle. The applications of these chromophoric nucleotides for investigating the mechanism of muscle contraction and other biological systems, particularly those involving guanosine nucleotide regulation, are discussed.


A novel system for the two-dimensional electrophoresis of membrane proteins.

Membrane proteins were resolved in two dimensions by a novel technique that uses discontinuous electrophoresis in both directions. After electrophoresis in the first direction in chloral hydrate, the membrane proteins were further resolved by a novel system that used organic-base dodecyl sulphates to stack and then resolve them. This latter system has several advantages over conventional electrophoresis in sodium dodecyl sulphate, notably that it avoids the production of artifacts generated by other systems.


A glycopeptide isolated from human gastric juice.

A glycopeptide containing 69% carbohydrate was isolated from human gastric juice. The complex was found to be homogeneous and to have mol.wt. 9600. The glycopeptide consisted of a protein core to which were linked, by O-glycosidic linkages to threonine and N-glycosidic linkages, carbohydrate side chains composed of N-acetylgalactosamine, N-acetylglucosamine, galactose, mannose, fucose and sialic acid, in the proportions 2:10:7:4:12:1.


Presence of 3-O-methyl-l-xylose in the lipopolysaccharide of Pseudomonas maltophilia N.C.T.C. 10257.

3-O-Methyl-L-xylose was isolated from whole cells of Pseudomonas maltophilia N.C.T.C. 10257. The sugar is a component of lipopolysaccharide from which a polysaccharide also containing L-rhamnose and L-xylose was released by mild acid hydrolysis. 3-O-Methyl-L-xylose was absent from five other strains of Ps. maltophilia and one strain of Pseudomonas geniculata.


Kinetic studies on the enzymes conjugating bile acids with taurine and glycine in bovine liver.

Synthesis of glyco- or tauro-cholate from choloyl-CoA and the respective amino acid is shown to be catalysed by the soluble fraction of liver cells. Kinetic evidence supports the conclusion that there are separate enzymes for the synthesis of glycocholate and taurocholate. The kinetic parameters of these enzymes were determined.


The preparation and characterization of bile pigments.

Brief reduction of bilirubin with dilute sodium amalgam was shown to give chromogens containing both vinyl and ethylidene beta-substituents. Acid-catalysed rearrangement of these chromogens with bilirubin or mesobilirubin and subsequent dehydrogenation gave a range of new violins containing unconjugated ethylidene and vinyl substitutents. Rearrangements between mesobilirubinogen, bilirubin and mesobilirubin gave dihydrobiliviolins, mesobiliviolins, biliverdins, dihydrobiliverdins and mesobiliverdins of the IIIalpha, IXalpha and XIIIalpha series. In this way 30 compounds were prepared, purified by t.l.c. as dimethyl esters, and characterized by n.m.r., mass and electronic spectroscopy, and by chemical interconversion and degradation.


Stereochemical considerations for constructing alpha-helical protein bundles with particular application to membrane proteins.

The stereochemical constraints originally used to construct two- and three-stranded alpha-helical coiled-coils were generalized for aggregates of alpha-helices containing from 4 to 14 alpha-helices in tubular bundles. Certain features of bacteriorhodopsin show excellent correlations with these stereochemical constraints.


Measurement of 1-aspartamido-beta-N-acetylglucosamine amidohydrolase activity in human tissues.

The activity of 1-aspartamido-beta-N-acetylglucosamine amidohydrolase (aspartylglucosylaminase, EC 3.5.1.26) was measured in normal and diseased human liver, brain and kidney. Organs from patients with aspartylglucosaminuria show very little activity. Crude homogenates of human organs show a reaction catalysed by a complex enzyme system. With homogenate, the formation of product was linear with time up to about 6 h. Reaction times longer than 6-7h resulted in a decrease in the total concentration of product. This phenomenon was not found with the partially purified enzyme fraction. Linearity of the enzyme activity with different protein concentrations was found, independent of the incubation time. Longer incubation of the crude homogenate resulted in the utilization of the product, N-acetylglucosamine. This phenomenon was not observed with the partially purified enzyme fraction. This amidase from human organs differs from that obtained from other sources and apparently represents a rather complex enzyme system.


The influence of lysosomes on glycogen metabolism.

Lysosome-rich fractions were isolated from rat liver homogenates. In some fractions the lysosomes were separated from the contaminating mitchondria by the use of discontinuous Ficoll/sucrose gradients. Some glycogen was associated with lysosome fractions. This glycogen was of very large molecular size and of a quite different molecular-weight distribution from that isolated from the cytosol. It is suggested that appreciably more than 10% of cellular glycogen is located within the lysosome.


The molecular size and shape of liver glycogen.

The molecular-weight distribution of liver glycogen has been established from the analysis of sedimentation rates of fractions separated on sucrose density gradients and from the direct measurement of the diffusion coefficients of these fractions by laser-intensity-fluctuation spectroscopy. Hydrodynamic studies indicated that all fractions of glycogen of mol.wt.exceeding 25x10(6) had about 1.1 g of water per g of polysaccharide associated with them. The hydration and hydrodynamic behaviour of all fractions of mol.wt. exceeding 25x10(6) was similar, whereas smaller fractions behaved anomalously, indicating a substantially different overall structure.


The structure and enzymic activities of the C1r and C1s subcomponents of C1, the first component of human serum complement.

The subcomponents C1r and C1s and their activated forms C-1r and C-1s were each found to have mol.wts. in dissociating solvents of about 83000. The amino acid compositions of each were similar, but there were significant differences in the monosaccharide analyses of subcomponents C1r and C1s, whether activated or not. Subcomponents C1r and C1s have only one polypeptide chain, but subcomponents C-1r and C-1s each contain two peptide chains of approx. mol.wts. 56000 ("a" chain) and 27000 ("b" chain). The amino acid analyses of the "a" chains from each activated subcomponent are similar, as are those of the "b" chains. The N-terminal amino acid sequence of 29 residues of the C-1s "a" chain was determined, but the C-1r "a" chain has blocked N-terminal amino acid. The 20 N-terminal residues of both "b" chains are similar, but not identical, and both show obvious homology with other serine proteinases. The difference in polysaccharide content of the subcomponents C-1r and C-1s is most marked in the 'b' chains. When tested on synthetic amino acid esters, subcomponent C-1r hydrolysed both lysine and tyrosine ester bonds, but subcomponent C-1r did not hydrolyse any amino acid esters tested nor any protein substrate except subcomponent C1s. The lysine esterase activity of subcomponent C1s provides a rapid and sensitive assay of the subcomponent.


Chemical and physical characterization of a phosphoprotein, Protein C, from human saliva and comparison with a related protein A.

The isolation of a highly purified phosphoprotein, previously named protein C, from human parotid saliva is described. A chemical and physical characterization of protein C was undertaken and the properties of protein C were compared with those of a related protein A. The content of glycine, proline and dicarboxylicamino acids accounts for 83% of the total resideus of protein C and it contains 2.0 mol of P/mol of protein, most likely as phosphoserine. The protein also contains 1.2% glucose, but no hexosamine. The N-terminus is blocked and the proposed C-terminal sequence is -Ser(Gly, Pro)Gln. The molecular weight determined from ultracentrifugation is 16300. Circular dichroism and nuclear magnetic resonance fail to demonstrate the presence of polyproline structure, and there are no conformational changes under a variety of conditions. With specific antisera to protein C the protein can be detected in submandibular as well as in parotid saliva, but there is only reaction of partial identity of proteins A and C. It is proposed that at least part of the difference between proteins A and C is due to the presence of an additional length of peptide at the C-terminus of protein C.


A serological investigation into the acidic alpha-D-mannosidase in normal Angus cattle and in a calf with mannosidosis.

Antiserum was raised in a rabbit against bovine kidney acidic alpha-mannosidase that had been purified 570-fold by affinity chromatography on concanavalin A--Sepharose and Sepharose 4B-xi-aminohexanoylmannosylamine. The antiserum precipitated the acidic but not the neutral alpha-mannosidase in normal calf tissues. Human acidic alpha-mannosidase cross-reacted partially with the antiserum, emphasizing the close structural resemblance between the enzyme in the two species. The residual acidic alpha-mannosidase in the tissues of a calf with mannosidosis was also precipitated by the antiserum, the same volume of antiserum being required to precipitate a unit of alpha-mannosidase activity from the normal and pathological tissues. The concentration of cross-reacting material detected by antibody-consumption experiments in the organs of the calf with mannosidosis appeared to be proportional to the concentration of the residual acidic alpha-mannosidase. It is suggested that the residual acidic alpha-mannosidase in mannosidosis accounts for the cross-reacting material detected and that it is unlikely that enzymically inactive but cross-reacting material is present. The residual acidic alpha-mannosidase could be a decreased concentration of the normal gene product or an altered enzyme with a decreased specific enzymic activity and a correspondingly decreased antigenicity.


Oxidation--reduction potentials of turkey liver xanthine dehydrogenase and the origins of oxidase and dehydrogenase behaviour in molybdenum-containing hydroxylases.

Redox potentials for the various centres in the enzyme xanthine dehydrogenase (EC 1.2.1.37) from turkey liver determined by potentiometric titration in the presence of mediator dyes, with low-temperature electron-paramagnetic-resonance spectroscopy. Values at 25 degrees C in pyrophosphate buffer, pH 8.2, are: Mo(VI)/Mo(V)(Rapid),-350 +/- 20mV; Mo(V) (Rapid)/Mo(IV), -362 +/- 20mV; Fe-S Iox./Fe-S Ired., -295 +/- 15mV; Fe-S IIox./Fe-S IIred., -292 +/- 15mV; FAD/FADH,-359+-20mV; FADH/FADH2, -366 +/- 20mV. This value of the FADH/FADH2 potential, which is 130mV lower than the corresponding one for milk xanthine oxidase [Cammack, Barber & Bray (1976) Biochem. J. 157, 469-478], accounts for many of the differences between the two enzymes. When allowance is made for some interference by desulpho enzyme, then differences in the enzymes' behaviour in titration with xanthine [Barber, Bray, Lowe & Coughlan (1976) Biochem. J. 153, 297-307] are accounted for by the potentials. Increases in the molybdenum potentials of the enzymes caused by the binding of uric acid are discussed. Though the potential of uric acid/xanthine (-440mV) is favourable for full reduction of the dehydrogenase, nevertheless, during turnover, for kinetic reasons, only FADH and very little FADH2 is produced from it. Since only FADH2 is expected to react with O2, lack of oxidase activity by the dehydrogenase is explained. Reactivity of the two enzymes with NAD+ as electron acceptor is discussed in relation to the potentials.


Characterization of two triacylglycerol lipase activities in pig post-heparin plasma.

Two triacylglycerol lipase activities were characterized after partial purification from pig post-heparin plasma. These two lipase activities were eluted sequentially with a NaCl gradient from columns containing Sepharose with covalently linked heparin. The first lipase activity, which was eluted at 0.75M-NaCl, was not inhibited at 28 degrees C in the presence of 1M-NaCl and was not further activated by plasma apolipoproteins. The absence of this lipase activity from post-heparin plasma from hepatectomized pigs indicates that the liver plays a role in the synthesis of this enzyme. A second lipase activity, which was eluted at 1.2M-NaCl, was inhibited when assayed in the presence of 1.0M-NaCl and was activated 14-fold by an apolipoprotein isolated from human very-low-density lipoprotein. The characteristics are identical with those of lipoprotein lipase purified from pig adipose tissue.


The action of proteolytic enzymes on the glycoprotein from pig gastric mucus.

A glycoprotein of mol.wt. 2x10(6) was isolated in homogeneous form from pig gastric mucus by isopycnic centrifugation in CsCl but without enzymic digestion or reductive cleavage of disulphide bonds. Digestion of the purified glycoprotein with trypsin, pepsin or Pronase resulted in the formation of glycoprotein subunits, of mol.wt. 5.2x10(5)-5.8x10(5), one-quarter that of the undigested glycoprotein. The glycoprotein subunits were isolated by gel filtration and shown to contain all the carbohydrate present in the undigested glycoprotein, but 18.6-25.6% of the total amino acids originally present were lost on digestion. The relative amount of threonine, serine and proline had increased from 41% (w/w) in the undigested glycoprotein to 61-67% of the total amino acids in the glycoprotein subunits after digestion. The results support the previously proposed structure for the glycoprotein, namely that of four subunits joined by disulphide bridges. These results show the presence of two distinct regions in the glycoprotein molecule, one rich in threonine, serine and proline, which is glycosylated and resistant to proteolyis, whereas the other, with an amino acid composition more characteristic of a globular protein, is not glycosylated and is susceptible to proteolysis. In addition, the region that is susceptible to proteolysis contains the disulphide bridges which join the glycoprotein subunits together to form the gastric glycoprotein.


A simple method for purification of epoxide hydratase from rat liver.

Rat liver epoxide hydratase was purified 460-fold to homogeneity by detergent solubilization and ion-exchange chromatography. The enzyme obtained in high yield (36%) exhibited a specific activity of 479nmol of styrene glycol formed/min per mg of protein, with styrene oxide as substrate. Only one polypeptide-staining band, mol.wt. 49500, was visible after sodium dodecyl sulphate/polyacrylamide-gel electrophoresis.


Phosphorylation of synaptic-membrane proteins from ox cerebral cortex in vitro. Preparation of fractions enriched in phosphorylated proteins by using extraction with detergents and urea, and gel filtration.

Synaptic-membrane fragments from ox cerebral cortex contain basal and cyclic AMP-stimulated protein kinase(s) that transfer 32P from [gamma-32P]ATP to hydroxyl groups of serine and threonine residues in membrane-protein substrates. In the present work, labelled membrane fragments were partitioned into soluble and insoluble fractions with Triton X-100, Nonidet P. 40, sodium deoxycholate and urea, and the distribution of 32P-labelled protein in the fractions was determined by polyacrylamide-gel electrophoresis and radioautography. A high percentage of phosphorylated protein sustrates remained insoluble, including those whose phosphorylation was most highly stimulated by cyclic AMP. Whole membrane fragments and samples prepared by detergent extraction were fractionated on Sepharose 6B columns in the presence of low concentrations of sodium dodecyl sulphate and pooled fractions were analysed by polyacrylamide-gel electrophoresis and radioautography. Phosphorylated proteins were fractionated on the basis of their molecular weight, but homogeneous protein was not obtained. The results are discussed in relation to the techniques used and the results obtained in other laboratories.


The role of the imidazolyl nitrogen atoms of histidine-12 in ribonuclease S.

S-peptide (residues 1--14) analogues in which the active histidine-12 residue is replaced by Npi-methyl-L-histidine, Ntau-methyl-L-histidine and beta-(pyrid-3-yl)-L-alanine were synthesized and tested for their capacity to bind to S-protein and to activate it. The results show that both imidazolyl nitrogen atoms are required for optimal catalytic functioning, Ntau being essential to the catalytic reaction itself, Npi playing a role in keeping the imidazole ring in the correct position.


Different reactivities of free and bound amino groups in deoxy-and liganded haemoglobin.

The technique of competitive double-labelling [H. Kaplan, K.J. Stevenson & B.S. Hartley, (1971) Biochem. J. 124, 289-299; L.P. Visentin & H. Kaplan (1975) Biochemistry 14, 463-468] was used to determine the reactivity of some amino groups towards acetic anhydride in deoxy-and liganded haemoglobin. Only those amino groups known to form salt bridges in deoxy-but not in liganded haemoglobin (i.e. the alpha-amino group of valine-1 alpha and the xi-amino group of lysine-40 alpha and lysine-127 alpha [M. F. Perutz (1970) Nature (London) 228, 726-739]) and different reactivities in the two structures.


Protein chromatography on adsorbents with hydrophobic and ionic groups. Purification of human erythrocyte glycophorin.

Human erythrocyte glycophorin was purified rapidly by (a) chromatography of a Triton X-100 extract of erythrocyte 'ghosts' on N-(3-carboxypropionyl)aminodecyl-Sepharose in buffers containing Triton X-100 or sodium dodecyl sulphate, or (b) chromatography of whole 'ghosts', solubilized in sodium dodecyl sulphate, on dodecyl-Sepharose, in buffers containing sodium dodecyl sulphate. The products contained 85-95% glycophorin (electrophoretic band PAS-1) and the major contaminants were glycoproteins PAS-2 (possibly a subunit of glycophorin) and PAS-3.


Increased frequency of HLA-Cw3 and HLA-Dw4 in rheumatoid arthritis.

Thirty-nine patients with rheumatoid arthritis were HLA typed for the full range of A and B locus specificities and for Cw3 and Dw4. HLA-Dw4 was significantly more frequent in patients (36%) than in controls (13%). The frequency of Cw3 was also increased, probably because this allele is in linkage disequilibrium with Dw4.


Pulmonary function in scleroderma.

Pulmonary function tests were performed in 45 patients with scleroderma. Thirteen patients (29%) were found to have restrictive disease, 12 patients (27%) were found to have obstructive disease, and 19 patients (42%) had small airway disease (SAD). Smoking did not seem to be a factor underlying either obstructive or small airway disease in these patients. A low diffusing capacity was most common in patients with restrictive disease and rarely the only abnormality in pulmonary function. SAD was usually found in patients who had normal chest radiographs and no pulmonary symptoms and was often the only abnormality. SAD is therefore an early and sensitive indicator of pulmonary involvement in scleroderma.


Brown's syndrome. An unusual manifestation of rheumatoid arthritis.

Two patients presented with an ocular complication of rheumatoid arthritis that was extraocular in location. Clinical manifestations include vertical diplopia, an intermittent nature, a clicking sensation, and apparent inferior oblique palsy. A stenosing tenovaginitis of the superior oblique tendon and its sheath is the probable underlying pathologic mechanism.


Surface ultrastructure of rheumatoid articular cartilage.

Six rheumatoid articular cartilage specimens, which appeared grossly normal and were shown to be free of pannus when examined under the light microscope, were examined electron microscopically. For comparison, normal-appearing cartilage specimens from 2 patients with meniscus injury and 2 with degenerative joint disease (DJD) were also examined. In all cases the normal-appearing joint surface of rheumatoid cartilage was abnormal. Amorphous-appearing material was present to a depth varying between 6 and 25 micron. Some of this material had the appearance of fibrin deposited at the cartilage surface, but much appeared to represent breakdown products of the cartilage matrix, i.e. degraded collagen and proteoglycan. DJD cartilage did not show similar changes. The findings suggest that the surface of rheumatoid articular cartilage, even when grossly normal in appearance, is degraded by enzymes either present in the synovial fluid or released by polymorphonuclear cells in close contact with the cartilage surface.


Hip joint restoration in juvenile rheumatoid arthritis.

Six children with long-standing juvenile rheumatoid arthritis and radiographic evidence of severe hip joint damage were found 6 months to 5 years afterward to have radiographic evidence of significant hip joint space widening and remodeling of articular surfaces. The disease activity had decreased and hip joint function had improved in all children. Each child had received various antiinflammatory drugs, but no specific medication could be implicated in the improvement. Evidence from animal studies suggests that intensive physical therapy with emphasis on continued weight bearing may have been important in promoting healing in these children. It appears that restoration of severely damaged hip joints in JRA can occur when the disease activity is controlled. Restoration may be favored by a child's greater potential for bone remodeling and by vigorous physical therapy with emphasis upon continued ambulation.


Relation between HLA-B27 and clinical features in patients with yersinia arthritis.

A study of 74 yersinia arthritis patients implied that the clinical picture of the disease may be modified by genetic background associated with the histocompatibility antigen B27 (HLA-B27). Sixty-six percent of patients were B27 positive. Joint symptoms were somewhat more severe in B27+ patients. Iritis, conjunctivitis, carditis, signs of urologic inflammation, and complete Reiter's triad occurred only in the B27 + group, whereas erythema nodosum was more common in B27 - group. Several B27 + patients also had "B27 + rheumatic diseases," such as ankylosing spondylitis or Reiter's disease, in their history.


Plant thorn synovitis.

Five children with an inflammatory monarthritis due to penetration of the joint by plant thorns are presented. The clinical presentation was that of a transient acute synovitis followed by a relatively asymptomatic period, and later by chronic arthritis often after the thorn injury was forgotten. Histopathology demonstrated a granulomatous synovitis. Polarized light microscopy facilitated identification of the plant tissue within the synovium. Conservative medical therapy was ineffective, but surgical excision of the affected synovium resulted in normal joint function. The differential diagnosis of monarthritis in children in extensive, and awareness of this condition is necessary to elicit a comprehensive history and to avoid delay in treatment.


Thoracic duct drainage in SLE with cutaneous vasculitis. A case report.

A 25-year-old woman had systemic lupus erythematosus manifested primarily by severe cutaneous vasculitis that was unresponsive to oral prednisone and azathioprine. She was treated with thoracic duct drainage (TDD). Her course was followed by serial photographs, skin biopsies, and serum immunoglobulin, antinuclear antibody, and complement levels. After 1 week of drainage there was obvious clinical improvement. During the remainder of her drainage, the vasculitis continued to improve. It was possible to taper oral corticosteroids and to discontinue azathioprine during TDD without any clinical or laboratory evidence of exacerbation. The patient had no recurrence of vasculitis 22 weeks after the termination of TDD.


Mechanisms underlying the suppression of adjuvant-induced arthritis by 6-mercaptopurine.

Daily oral administration of 6-mercaptopurine suppressed the development of the secondary (immune) lesions of adjuvant arthritis in a dose-related manner. The degrees of arthritis suppression corresponded closely to suppressions of concurrent development of the humoral and the cellular immune response to El4 cells. A short course of therapy during the sensitization period (day - 1 to day 5 when the day of adjuvant injection is designated as day 0) appeared to be almost as effective as continued daily dosing (day - 1 to day 15). The drug did not influence the development of the primary (nonimmune) lesions of adjuvant arthritis at all dosage levels investigated. Chronic pretreatment with 10 mg/kg/day PO for 17 days had no effect on the development of carrageenin-induced acute inflammation in the rat. The suppression of adjuvant arthritis by 6-mercaptopurine, unlike suppression by cyclophosphamide, appears to result primarily from its suppressive action on the immune response.


The public health implications of ethnomedical practices.

The public health implications of ethnomedical practices are extensive. In particular, there is the need to research the cultural and social behaviour patterns relevant to health care in order to utilise aspects of ethnomedical practices within a comprehensive health care system. To exploit the positive aspects of the ethnomedical practices successfully, health education for the consumers (the population) and the producers (the health workers) must be developed. Because of the limited resources of most developing countries and as a part of the movement away from "industrialized medicine", a large number of health auxiliary workers, including ethnomedical practitioners, need to be trained and deployed to develop and maintain this new health care system.


The teaspoon dose.

A teaspoon dose (5 ml) is not necessarily a paediatric dose, since the amount of a drug in 5 ml of a preparation may not be the same as that in a tablet. Suggestions for standardizing the quantities of medicine in liquid form are given and the 'Ten Commandments' for safe prescribing for infants and children are stated.


Acute coronary insufficiency. Review of 46 patients.

Forty-six patients admitted with acute coronary insufficiency are reviewed. All were investigated by coronary angiography; 4 had normal coronary arteries and are included in this study; the remainder had a distribution of coronary artery disease similar to other angina patients. The clinical and angiographic findings, management, and subsequent course of the other 42 patients are presented. Fourteen patients (33%) in whom rest pain persisted after 48 hours underwent emergency coronary angiography, with 3 deaths; of the surviving 11 who had acute saphenous vein bypass grafting, 2 died at operation and 3 had perioperative myocardial infarctions. Seventeen patients (41%) who initially improved required surgery within 6 months because of symptoms. Eleven patients (26%) were not operated on. It is concluded that acute coronary insufficiency is best managed initially by intensive medical therapy but a high proportion will require surgery later because of disabling angina. Early investigation and surgery are associated with a high mortality and incidence of myocardial infarction. Survivors of surgery are symptomatically improved and there is a low incidence of late infarction and death.


Serum myoglobin level as diagnostic test in patients with acute myocardial infarction.

Serum myoglobin levels were measured in normal subjects and patients by means of a newly developed radioimmunoassay. Myoglobin was identified in all of 135 sera from normal adults and ranged between 6 and 85 ng/ml (mean +/- SE 31 +/- 1.3). Raised myoglobin levels were present in 62 of 64 patients with documented acute myocardial infarction, the mean serum concentration being 528 +/- 76 ng/ml. Serial determinations in 46 patients with acute infarct showed that maximum values usually occurred within 4 hours after admission. In 19 of 42 cases, raised myoglobin levels preceded the rise in creatine kinase (CK) values; in the remaining patients, both serum myoglobin and creatine kinase were increased on admission. Only 2 of an additional 44 patients admitted with chest pain but without subsequent electrocardiographic, enzyme, or technetium-99m stannous pyrophosphate myocardial scintigraphic evidence of acute myocardial infarction had raised myoglobin levels; the mean value for this group was within the normal range (44 +/- 6 ng/ml). Serum myoglobin values also were normal in patients with congestive heart failure without acute myocardial infarction, and in patients after moderate exercise and cardiac catheterisation. Trasient myoglobinaemia appears to be one of the earliest laboratory abnormalities occurring in acute myocardial infarction and, therefore, should prove useful as a diagnostic aid in patients.


Reproducibility of echocardiographic estimates of left ventricular dimensions.

Although echocardiography is ideally suited for repetitive use on a patient for evaluation of left ventricular function, the value of this application is minimised by the uncertainty as to whether changes in left ventricular dimensions observed on a patient at different times or by different observers are real or result from the ultrasonic beam penetrating the left ventricle at different angles. Accordingly, an instrument was designed and constructed in our laboratory to improve the reproducibility of echocardiographic measurements of left ventricular dimensions. The instrument represents an orthogonal reference frame by means of which the spatial orientation of the ultrasonic beam relative to the chest is determined and reproduced in subsequent studies, while the point of entrance of the beam is marked on the chest wall. Using this instrument, left ventricular echograms were initially recorded on a group (I) of 23 subjects with or without heart disease and the study was repeated 8 hours to 49 (mean 7) days later by the same observer and also, in 16 cases, by an independent observer. The average values from 2 to 6 (mean 4) heart cycles were used for the left ventricular end-diastolic dimension (Dd), end-systolic (Ds) dimension, and their difference (delta D). Differences in all three variables between studies were random and statistically insignificant, never exceeding 3-5 mm for Dd or Ds, and 4 mm for deltaD. For comparison, left ventricular internal dimensions were also obtained in a seprate group (II) of 14 subjects by the standard method of using the mitral valve as an internal landmark, without the benefit of this instrument. All 14 subjects had the initial study repeated within 8 hours to 11 (mean 3-8) days later by the same and also by an independent observer. Though in the group as a whole there was no significant difference in left ventricular dimensions between studies, individual variations reached 11 mm for Dd, 9 mm for Ds, and 9 mm for deltaD, and the degree of scatter was significantly larger than in group I. This initial experience indicates that the use of this instrument improves the reproducibility and enhances the reliability of estimates of echocardiographic left ventricular dimensions and function on a patient examined at different times by the same or independent observers.


Primary restrictive cardiomyopathy. Non-tropical endomyocardial fibrosis and hypereosinophilic heart disease.

Eleven patients with a restrictive cardiomyopathy are described. Seven of these had biventricular disease and in them the haemodynamic abnormality resembled that in constrictive pericarditis but the condition was distinguishable because of unequal involvement of the two ventricles, murmurs of atrioventricular valve regurgitation, or characteristic ventricular deformity on angiography. Two of these patients had eosinophilia with the clinical features of Löffer's endocarditis. In 4 patients the disease was apparently confined to the left ventricle; they were investigated on account of atypical chest pain, third heart sound, or abnormal electrocardiogram. Simultaneous measurements of left ventricular pressure and volume throughout diastole were made in 3 patients and showed rapid but abruptly curtailed left ventricular filling. Transvenous endomyocardial biopsy in 2 patients showed fibrous tissue with collagen and irregular elastic fibrils. Surgical biopsy in 3 patients excluded pericardial constriction but was diagnostically unhelpful because of failure to obtain endocardium. Necropsy in one patient showed that the heart had features indistinguishable from tropical endomyocardial fibrosis. It is suggested that the spectrum of ventricular abnormalities in these patients results from endomyocardial fibrosis of varying severity and probably of differing cause. This study has shown that "tropical" endomyocardial fibrosis may occur outside the tropics and suggests that eosinophilia may play a leading role or associated part in the genesis of some cases.


Atresia of the right atrioventricular orifice.

The results are reported of a study of 83 necropsied hearts with atresia of the right atrioventricular orifice. It is emphasised that right atrial or atrioventricular orificial atresia is a better term to describe this anomaly than "tricuspid atresia". Use of the latter term can be confusing when the morphologically tricuspid valve is located beneath the left atrium. It is accepted that the definition employed may include cases in which the mitral valve may be atretic, blocking normal exit from the right atrium, but it is argued that such cases would present clinically as "tricuspid atresia" and therefore are correctly designated as right atrial orificial atresia. The results show that the majority of hearts with right atrial orificial atresia have the ventricular morphology of primitive ventricle, most with, but a few without an outlet chamber. However, in a minority of hearts an imperforate membrane interposes between the right atrium and a formed but hypoplastic right ventricle. In two of the hearts, the imperforate membrane showed features of Ebstein's malformation. The hearts could be further subdivided according to the ventriculoarterial connection. Most had normally connected arteries (66 of 83), and all but 2 also had normal relations between the arteries; in these 2 hearts there was "anatomically corrected malposition". Twelve hearts showed transposition, one had double-outlet outlet chamber, and another persistent truncus arteriosus. The remaining 3 hearts, all without outlet chamber, had by definition a double outlet connection. A segmental approach provides the best way of classifying this anomaly, and an embryological explanation is offered for the variations in anatomy observed.


Total anomalous pulmonary venous drainage in infancy.

Between May 1971 and December 1975, 39 infants had operations for correction of total anomalous pulmonary venous drainage. Fourteen of the 39 patients were under 1 month of age at the time of operation. Twenty-four patients had supracardiac, 7 intracardiac, and 6 infracardiac total anomalous pulmonary venous drainage, and 2 had a mixed type. The overall hospital mortality was 36 per cent. There have been no late deaths. The improvement in survival rate in this series is attributed to: (1) earlier recognition and prompt referral, (2) an aggressive approach to diagnosis involving complete cardiac catheterisation and angiocardiography, (3) vigorous preoperative care, (4) early complete correction including construction of a large anastomosis and enlargement of the left atrium when indicated, and (5) intensive postoperative management paying particular attention to fluid balance and treatment of pulmonary complications. Operative mortality was highest in patients with total anomalous pulmonary venous drainage directly to the superior vena cava, and in those with infradiaphragmatic drainage of whom all had pulmonary venous obstruction. Mortality was not closely related to age, body weight, or severity of pulmonary hypertension.


Two unusual cases of intra-atrial gap.

Two cases are described in which, during investigation of rhythm disturbances, it was shown that, by delivering atrial stimuli of increasing prematurity, a point was reached where the artificial stimulus failed to induce an atrial response. However, with even more premature stimulations, atrial responses were again observed. These observations are best explained by a gap phenomenon in which very early stimuli delivered during the effective refractory period of the atria were delayed long enough in the exit area around the pacing electrode to allow atrial recovery.


Infective endocarditis caused by Streptococcus mutans.

Members of the viridans group of streptococci are the commonest causes of bacterial endocarditis. However, Streptococcus mutans, a member of this group associated with dental caries which might be expected to be commonly associated with endocarditis, has only rarely been reported. This is possibly because of difficulties in isolation and identification. Differing blood culture media may affect the chances of isolation of these organisms, and, though brain-heart infusion, thiol, tryptic soy, and glucose-brain infusion broths have all proved satisfactory, subcultures may require increased CO2 concentrations for growth. Plemorphism in the resultant colonies and in the individual organisms may give rise to a hazardous misinterpretation of this appearance as contamination. Strep. mutans and the similarly penicillin sensitive Strep. bovis may be differentiated from the penicillin resistant enterococci by their lincomycin sensitivity and intolerance of 6-3 per cent sodium chloride. Precise differentiation of streptococci in bacterial endocarditis is of value both epidemiologically and in the management of the disease.


Further studies of the relationship between lymphatic dissemination and lymphnodal metastasis in non-immunogenic murine tumours.

In all 6 different murine tumours of spontaneous origin, a high proportion (22-95%) of the regional lympgh nodes draining small intradermal tumours gave rise to tumours after their isogeneic transplantation as whole nodes. In separate experiments with 4 of these tumours, equivalent tumour-bearing mice had their tumours surgically excised and were observed for the development of regional nodal corresponding frequency of tumour formation by transplanted nodes. After high-dose radiotherapy of intradermal carcinomas, there was a progressive fall in the incidence of positive regional node transplants from 48 to 96 h after irradiation. It is concluded that continual lymphatic dissemination of viable cancer cells is characteristic of malignant tumours, but that there is a relatively small chance of such cells giving rise to nodal metastatic growth. Related studies showed that the ability of a small number of cancer cells to give rise to tumours was very much greater if they were incorporated in a lymph node at transplantation than if they were transplanted directly as a suspension.


Effects of dexamethasone and betamethasone on in vitro cultures from human astrocytoma.

Cultures of human astrocytoma have been derived by collagenase digestion and are presumed, from their aneuploid karyotypes, to be predominantly neoplastic. Early passage cultures in proliferative phase have been cloned in the presence of dexamethasone and betamethasone, both commonly used in management of patients with brain tumours. These steroids raise both the cloning efficiency and the proliferative capacity of cells within each clone. Inhibition was detected only in very high steroid concentrations (25-50 microng/ml). Since these concentrations are unlikely to be attained in vivo it is concluded that anticipated physiological levels of these steroids enhance cell survival at low densities in culture. The significance of this in vivo is discussed.


Effect of ascorbic acid on tumour growth.

The growth of tumours in guinea-pigs was observed for 20 weeks after placing them on various doses of vitamin C. Complete tumour regression occurred in 55% of those animals receiving 0-3 mg/kg/day ascorbic acid, whereas animals given 10 mg/kg/day showed tumour inhibition but no regression. In contrast, tumours in animals maintained on 1 g/kg/day ascorbic acid grew without sign of retardation. When increased amounts of ascorbic acid were restored to the diet of scorbutic tumour-bearing animals, tumours which had not regressed responded with enhanced growth. Likewise, animals previously maintained on 10 mg/kg ascorbic acid responded in turn to the additional vitamin with enhanced tumour growth. In contrast, all tumour-bearing animals maintained on 1 g/kh ascorbic acid died within 3 weeks when this dose was replaced with 0-3 mg/kg.


Radiosensitizing and cytocidal effects on hypoxic cells of RO-07-0582, and repair of x-ray injury, in an experimental mouse tumour.

The delay in regrowth to 10 mm diameter of a transplanted carcinoma in mice was used to estimate the effect of the hypoxic-cell radiosensitizer Ro-07-0582. When 1 mg/g body wt. was given before a single dose of X-rays, a dose-enhancement ratio of 2-0 was found. When the drug was given immediately after irradiation, a large cytotoxic effect was observed, equivalent to an enhancement ratio of 1-3. These results were confirmed by determining the X-ray doses required for the local control of 50% of the tumours at 80 days after irradiation. The capacity of the tumour for repair of sublethal X-ray injury within 24 h was similar to that for several normal tissues.


Growth kinetics of Kaposi's sacroma.

This is a study of cell kinetics in nodular and florid (fungating) Kaposi's sarcomas. One or more tumours from 9 patients were examined at the Uganda Cancer Institute. The very variable clinical doubling time was assessed by direct measurements of tumour diameters, and an average obtained. The mitotic count, rate of entry of cells into mitosis and cell cycle time were measured in biopsy material, and use to estimate the potential doubling time. From the difference between the potential and the actual doubling times, the rate of cell loss and the cell loss factor were calculated. The average actual clinical doubling time was slightly, but not significantly, higher for growing nodular tumours than for florid tumours. Some nodular tumours were similar to those reported in the literature for other human malignacies. Kinetic studies of static and regressing human tumours have not been reported previously. The rate of cell production found in this tumour is lower than the values reported in the literature for other malignancies. The calculated mitotic duration is long, but similar to previously reported values. The cell loss factor is high: in the static tumours it is 1.0, and in the regressing tumours greater than 1.0. In regressing tumours, the rate of cell loss was 30% higher than the rate of cell production. These tumours did not differ histologically from nearly florid tumours which were increasing in size. It is postulated that regression is determined by local vascular or mechanical factors, supplemented possibly by delayed hypersensitivity responses in some patients.


Burkitt's lymphoma in British adults: clinical features and response to chemotherapy.

Eight British adults with tumours histologically and cytochemically identical to African Burkitt's lymphoma are described. In each case there was an acute clinical onset and similar tumour distribution, with involvement of the intra-abdominal organs, bone marrow and central nervous system. Jaw tumours were only present in 3 cases, and were never gross. Four patients presented as acute leukaemia. Combination chemotherapy and cranial irradiation were used to eradicate disease, but complete remissions were obtained in only 3 patients, and survival of over 1 year in only 2. The remainder died with disease present, less than 5 months from diagnosis.


The effect of intracutaneous injections of micronized crystalline suspensions of nandrolone phenyl-propionate in the skin of female hairless hamsters.

Single intracutaneous injections of micronized crystalline suspensions of nandrolone phenylpro-pionate have been shown to induce local thickening of the epidermis of female hairless hamsters, accompanied by a marked increase in sebaceous gland volume over a period of 7 days. It is known that certain materials, when injected intracutaneously, may produce a diffuse inflammatory response in the dermis which in turn causes hyperplasia in the adjacent epidermis. The response observed in the present case, however, is clearly specific to nandrolone phenylpropionate, and cannot be attributed to an inflammatory response of the dermis to intracutaneously injected crystalline material.


The effect of various treatments on the size of sebaceous glands of hairless mice and hairless hamsters.

The effect of castration on the size of sebaceous glands of male hairless mice and male hairless hamsters was studied over a period of 4 weeks. Statistically significant decreases in the size of sebaceous glands were observed. The effects of intracutaneous injections of micronized crystalline suspensions of testosterone, testosterone propionate, testosterone phenylpropionate, testosterone decanoate and nandrolone phenylpropionate on the sebaceous glands of castrated hairless mice, castrated hairless hamsters and intact female hairless hamsters were studied over a period of one week. Highly significant increases in sebaceous gland volume were observed 6-7 days after treatment. The effects of subcutaneous and intracutaneous injections of micronized crystalline suspensions of testosterone on the sebaceous glands of intact male and female hairless hamsters were examined at sites local and distal to the injection. Increases in sebaceous gland volume were limited to local sites in the male but increases were observed locally and distally in the female. There was no difference between subcutaneous and intracutaneous injections.


Maffucci's syndrome: amesenchymal dysplasia and multiple tumour syndrome.

A case of Maffucci's syndrome with cutaneous, bony and neurological complications is reported. The patient had lymphangiomatosis at birth and developed multiple cutaneous haemangiomas and osteochondromas during childhood. She also developed multiple neurological defects, including cranial nerve palsies due to an intracranial osteochondroma. The occurence of mesodermal dysplasias and neoplasias in the Maffucci syndrome is emphasized, and it is suggested that there is a close relationship between this disorder and Ollier's disease (multiple enchondromatosis).


Platelet antibodies in thrombocytopenic patients.

Platelet antibodies either bound to the surface of platelets or free in the serum were sought in patients who had low platelet counts for a variety of reasons. They were detected by finding excess IgG on the surface of washed platelets either directly or after incubation of the serum with normal platelets. The technique used was a modification of that described recently (Dixon et al, 1975) in which the greater the amount of anti-IgG consumed by the reaction with platelets the less the subsequent lysis of sheep red cells coated with IgG. This test could be calibrated by adding known quantities of IgG to the  antisera and thus the amount of bound IgG could be measured. Platelets from normal donors and those with thrombocytopenia due to non-immunological causes such as aplastic anaemia or acute leukaemia were found to have 15-70 ng IgG/10(7) platelets (mean 53 ng). 37 out of 38 thrombocytopenic patients in whom immune destruction of platelets was suspected were found to have excess IgG on their platelets ranging from 70 to 720 ng/10(7) (mean 297 ng, P less than 0.001) and there was a significant inverse correlation between this amount and the platelet count (r = 0.85, P less than 0.001). Antibody in the serum was found in 14 of 22 patients with 'idiopathic' thrombocytopenic purpura (ITP), three of four patients with underlying lymphoma and in all five cases of systemic lupus erythematosus (SLE). Four non-thrombocytopenic patients with autoimmune haemolytic anaemia (AIHA) due to IgG on the red cells were also studied and were shown to have no increase in platelet-bound IgG. Our results confirm the work of Dixon et al (1975) that platelet antibody as excess IgG can be readily detected on the surface of platelets in patients with immune thrombocytopenia. The clinical implications of these findings are discussed.


Platelet antithrombins: role of thrombin binding and the release of platelet fibrinogen.

The nature of platelet antithrombin was elucidated by comparison of thrombin binding and antithrombin activities of intact platelets and by purification of antithrombin from platelet lysates using glycerol osmotic lysis, ethanol precipitation and Sephadex gel filtration techniques. The major portion of the antithrombin and thrombin binding activity of intact platelets is lost after brief sonication. The antithrombin activity in destroyed platelets is found to be due to platelet fibrinogen. Treatment of platelets with PGE1 (100 microng/ml) markedly inhibits (greater than 80%) the release of platelet fibrinogen induced by thrombin. However, the PGE1 treatment produced slight (less than 30%) but significant decrease of antithrombin activity of intact platelets, whereas the binding of thrombin to platelets was not affected by PGE1 treatment. The amounts of thrombin bound to and inactivated by PGE1-treated platelets at the same cell concentration are identical. The above results suggest that platelets contain at least two antithrombin activities. One, which accounts for the major portion of platelet antithrombin is mediated by thrombin binding to platelets. The other, which attributes to a lesser extent to platelet antithrombin activity, is due to the release of platelet fibrinogen. Also, antithrombin is readily demonstrated in a plasma medium indicating physiological significance of platelet antithrombin.


Effects of cephalothin and penicillin G on platelet function in vitro.

High concentrations of cephalothin or penicillin G inhibit a number of the functions of human or rabbit platelets in citrated platelet-rich plasma (PRP) and in suspensions of washed platelets. The reactions shown to be inhibited are: ADP-induced shape change and the primary and secondary phases of aggregation and release induced by ADP or adrenaline in human cirtated PRP; release and aggregation of washed human platelets exposed to collagen, thrombin, vasopressin, or the ionophore A 23,187; aggregation of washed human platelets exposed to phytohaemagglutinin from Phaseolus vulgaris (PHA) or polylysine; release induced by concanavalin A or PHA in suspensions of washed platelets from rabbits; platelet adherence to a collagen-coated surface or to the damaged intimal surface of the rabbit aorta; platelet factor 3 availability; lysis of rabbit platelets by an antiserum directed against them; and clot retraction. Neither antibiotic affected serotonin-induced aggregation; a high concentration of cephalothin slightly inhibited the initial rate of serotonin uptake. Penicilloic acid showed about half the inhibitory effect of penicillin G on ADP-induced aggregation. In citrated human platelet-rich plasma, ampicillin and oxacillin inhibited ADP-induced aggregation to the same extent as similar concentrations of penicillin G; in suspensions of washed platelets, however, ampicillin was less inhibitory than penicillin G or oxacillin. Platelet ultrastructure, assessed by transmission electron microscopy, was not visibly altered. Evidence that the antibiotics become bound to platelets is the finding that platelets incubated with the antibiotics ans resuspended in fresh media showed less response to aggregating agents compared with control platelets. Penicillin G and related antibiotics may be inhibitory because they coat the platelet surface. Their effects on platelet functions are probably responsible for excessive bleeding and increased bleeding times observed in patients and volunteers receiving high doses of these antibiotics.


Ferrokinetics and erythropoiesis in man: red-cell production and destruction in normal and anaemic subjects.

Recent advances in the analysis of plasma 59Fe clearance have produced a unified method for measuring effective and ineffective erythropoiesis (Ricketts et al, 1975). We have used this method to investigate the balance between red-cell production and destruction in normal subjects and in patients with megaloblastic anaemia, iron deficiency anaemia, and refractory hypoplastic anaemia. The results show that the normal marrow can maintain an appropriate red-cell mass by altering red-cell production to match destruction. In the anaemias we have studied there is an increased rate of either intra- or extra-medullary red-cell destruction. The response of the marrow may be limited by iron supply, by defective nuclear maturation or by some intrinsic marrow defect.