Space flight effects on the hemopoietic function of bone marrow of the rat.

The 22-d orbital flight of rats onboard the Cosmos-605 biosatellite was followed by inhibition of erythroblastosis, alteration in the morphology of megakaryocytes, and stimulation of myelopoiesis. These changes returned to normal 27 d postflight. The colony-forming capacity and pattern of differentiation of hemopoietic stem cells of bone marrow of flight rats remained undisturbed.


[Foil-mounted sections of entire lungs (Gough-sections). Technic and diagnostic significance (author's transl)].

The diagnostic significance of sectioning of entire lungs (Gough-sections) was investigated by application of different staining methods. The stained sections were mounted on transparent cellophan-foils. Macroscopic and microscopic results are satisfactory after staining for iron and neutral fat and after application of particular enzymatic reactions. This method is especially recommended in topographic problems.


[Effect of nicotine in pigs (author's transl)].

18 pigs in which venous catheters were positioned for long-term use were injected with nicotine in physiological saline: group 1: 1 mg without anaesthesia; group 2: 1 mg/animal, Hypnodil-anaesthesia; group 3: 0.0143 mg/kg body weight, Hypnodil-anaesthesia. The dose of 1 mg is corresponding to that amount of nicotine contained in the main smoke of a commercially used cigarette. The dose of 0.143 mg/kg body weight is calculated per 1 kg body weight assuming that a man of 70 kg body weight resorbes the total amount of nicotine (1 mg) after maximum inhalation. Application of 1 mg induced the following alterations: sino-auricular block, AV-block of first and second degree, asystolia up to 2 seconds, short decrease in blood pressure and bradycardia as well as flattening and/or inversion and biphasic reaction of T. A longer lasting increase in blood pressure was observed in non-anaesthesized animals. Animals treated with 0.0143 mg/kg body weight showed AV-block of first degree with subsequent extrasystoles. Blood pressure, heart rate and T-wave showed no alterations. Decisive for the induction and extent of acute disturbances seems to be the dose of nicotine. Therefore, a decrease of the nicotine content seems to be indicated toward a "less harmful cigarette".


Biochemical adaptations for flight in the insect.

1. Flight by insects is characterized by the most intense respiration known in biology and also the most controlled. Thus insect flight muscle may be the tissue of choice for the study of biochemical adaptation in the control of catabolism and biological oxidations, and many of the results obtained with insects have a significance and a relevance that transcend the boundaries between classes. In insects, such as the blowfly, flight is distinguished additionally by high wingbeat frequencies and an asynchronous type of excitation-contraction coupling. In spite of this intense muscular work, metabolic processes are not limited by the availability of oxygen. Also of importance is the morphological organization of the flight muscle and mitochondria, which have evolved ultrastructurally and biochemically into an effective catabolic machine. 2. In the fly, carbohydrate, principally glycogen, is the sole metabolic fuel; fats are not used in flight and enzymes concerned with fatty acid utilization are virtually lacking. Glycogenolysis does not lead to lactic acid; instead, the end products of glycolysis are pyruvate and alpha-glycerophosphate. The alpha-glycerophosphate cycle provides a mechanism not only for the reoxidation of glycolytically produced NADH but also for the stoicheiometric formation from each molecule of hexose equivalent of two molecules of pyruvate, which are then available for oxidation via the tricarboxylate cycle. The absence of dicarboxylate and tricarboxylate carriers from the mitochondria ensures that tricarboxylate-cycle intermediates do not exit from the mitochondrion but that pyruvate is oxidized to completion. On initiation of flight, mitochondrial oxidation of pyruvate is impeded by the lack of tricarboxylate-cycle intermediates for the generation of oxaloacetate. This is circumvented by the oxidation of proline. 3. The controls on metabolism in flight muscle, i.e. (1) glycogenolysis at phosphorylase and phosphorylase kinase, (2) glycolysis at phosphofructokinase, (3) alpha-glycerophosphate dehydrogenase, (4) proline dehydrogenase and (5) tricarboxylate cycle at isocitrate dehydrogenase, are effected by the phosphate potential and/or Ca2+. It is suggested that the metabolic changes, such as those seen in the rest-to-flight transition, are achieved by the concerted actions of these effectors at the different loci.


Metabolic consequences of submersion asphyxia in mammals and birds.

On submersion, the cardiovascular system of naturally diving animals is virtually transformed into a heart-brain-lung preparation as the result of intense and highly selective neurogenic vasoconstriction. A supply of oxygen from the circulating blood cells to the heart and the brain is thereby secured. Peripheral tissues, e.g. muscles and kidneys, have to depend on local stores of oxygen, i.e. myoglobin, or, when these are exhausted, on anaerobic metabolism. In spite of such physiological adjustments, however, arterial pO2 will inevitably decrease throughout the underwater episode. In prolonged dives values lower than 10mmHg can be observed. Moreover, the ischaemia in the peripheral tissues will, in some animals, e.g. arctic seals and whales, result in a profound decrease in the temperature of tissues such as the skin. The aim of the present report is to review some of the more important biochemical mechanisms that allow diving mammals and birds to cope with the above-mentioned combined asphyxic and temperature stresses for prolonged periods. Some of the osmotic problems arising from the rapid wash-out of acidic metabolic end products from the previously ischaemic tissues on emergence are also discussed.


Adaptations with respect to salinity.

Amino acids contribute up to about 50% of the intracellular osmotic pressure of aquatic invertebrates. Since their concentration varies according to the salinity of the medium (high in sea water, low in fresh water) euryhaline invertebrates are good models for studying the mechanisms involved in the control of amino acid metabolism. During hyperosmotic stress CO2 production and O2 consumption decrease whereas the reverse is true when the animal is submitted to a hypo-osmotic stress. Nitrogen excretion (as NH3) increases in media of low salinity and the concentration of cyclic AMP increases during hyperosmotic stress. Moreover, blood proteins and haemocyanin are more concentrated in individuals adapted to media of low salinity. To explain the situation, three main mechanisms can be considered: (a) hydrolysis and synthesis of blood proteins; (b) transport of amino acids across the cell membrane; (c) control of the turnover rate of some amino acids. Results obtained on whole animals as well as on isolated tissues indicate that some amino acids are released from the cells and carried via the haemolymph to the posterior pairs of gills where they are oxidized (mechanisms b) or to an organ (hepatopancreas ?) Where they are used for blood protein synthesis (mechanism a). The use of labelled substrates demonstrates that the turnover rate of amino acids is controlled by the salinity of the environment (mechanism c). It is suggested that inorganic ions trigger the metabolic response by directing reducing equivalents toward oxygen or 2-oxo acids through control of the catalytic activity of dehydrogenases.


Design of metabolic and enzymic machinery to fit lifestyle and environment.

Biochemical theory, spectacular as its growth has been in the last half-century, finds its experimental basis in a remarkably few organisms. The rat, the ox, the pig, the hen plus a few micro-organisms consitute the primary source of biochemistry's experimental material, while, by contrast, modern systematics estimates a bewildering and often overlooked diversity of over 10(6) animal species. As a result of this highly limited 'sampling' of nature, classical biochemistry has supplied an equally limited insight into how far biochemical mechanisms can be extended or adapted for (1) allowing an organism's exploitation of its environment and (2) accommodating environmental change. The situation has improved in more recent years, so that it is now possible to decipher at least the broad strategic outlines of biochemical adaptation to the environment. This essay focuses particular attention on the influence of O2 availability on muscle metabolic organization and control. By drawing examples of muscle metabolism spanning a range from obligate-anaerobic to obligate-aerobic organization, it is possible to demonstrate that certain kinds of metabolic features are highly conserved, whereas others are changed time and time again, in different combinations and permutations. The latter properties constitute the 'raw material' for adapting metabolism to specific O2 regimes, and include (1) the kinds and amounts of enzymes present in muscle, (2) the fine regulatory circuitry allowing for controlled transition from low to high work loads and (3) compensation mechanisms for the adjustment of enzyme reactions with respect to such external parameters as temperature, pressure, salinity and so forth. Within the inescapable limitations of phylogenetic origins and the time available for responding to specific environmental conditions, adequate adaptations of the fundamental design of muscle metabolism have evolved to exploit environments differing greatly in O2 availability and to accommodate a wide range of muscle functions.


Temperature: a "shaping force' in protein evolution.

1. Comparisons of homologous enzymes from species adapted to widely different temperatures reveal that ligand-binding affinities are rigorously conserved. This is interpreted to mean that a critical relationship between ligand-binding ability and intracellular ligand concentrations must be maintained for proper enzymic regulation. 2. The catalytic efficiencies of enzyme homologues differ in temperature-compensatory manners. Activation free energies are proportional to adaptation temperature and, consequently, low-temperature-adapted enzymes have the highest substrate turnover numbers. 3. Temperature compensatory adjustments in catalytic efficiency may be achieved by altering the number of weak bonds that form or break during a catalytic conformational change. Support for this hypothesis comes from the finding that activation enthalpy and activation entropy values co-vary in a regular manner and by magnitudes consistent with different amounts of weak-bond formation/rupture during catalytic activation in differnt enzyme homologues. 4. Adaptive adjustments in ligand-binding energetics may also involve utilization of the energy changes that occur during conformational changes. This mechanism would permit enzymes with identical binding-site chemistries to display adaptively different ligand affinities. 5. The greater heat-stabilities of enzymes from warm-adapted species may cause these enzymes to be less efficient catalysts than cold-adapted heat-labile enzymes. Heat-stable enzymes may have to break more weak bonds during a catalytic conformational change than do cold-adapted enzymes. The requirements for thermal stability and high catalytic efficiency thus appear to force an adaptational 'compromise'.


Halofenate in the treatment of type II hyperlipoproteinemia. Double blind comparison with clofibrate.

A double-blind study comparing halofenate, a new lipid-lowering investigation drug, with an established drug, clofibrate, was conducted on 33 clinic patients with Type II hyperlipoproteinemia for a period of 48-96 weeks. All but 10 patients had some type of symptomatic major vascular disease. With respect to serum cholesterol levels, a comparable proportion (56-59%) of patients in each group responded to the respective treatment but the magnitude of lowering was substantially less for the halofenate responders (12% mean decrease versus 25%). Type IIa patients in both groups were more likely than Type IIb patients to have a favorable cholesterol-lowering response. Weight gain of 5% or greater was prejudicial to cholesterol lowering. In the case of serum triglycerides, the proportion of patients responding to clofibrate treatment was somewhat greater (87% versus 57% for halofenate) but the mean magnitude of lowering (27-34%) was comparable for responders in the two groups. Weight gain did not influence appreciably the triglyceride-lowering effect. Elevated concentrations of triglyceride (Type IIb) in the control period favored a triglyceride lowering response by clofibrate but was only a moderate influence on the response to halofenate.


Arrhythmias in two patients with left ventricular bypass transplants.

Two patients who underwent left ventricular bypass transplants are described. Both patients sustained postoperative rhythm disturbances of their own hearts during sinus rhythm of the donor hearts. Illustrative examples of atrial flutter, ventricular flutter, ventricular fibrillation, blocked atrial extrasystoles, and double ventricular parasystole in the recipient hearts are presented. The patients tolerated all these arrhythmias well during uninterrupted sinus rhythm in the donor heart. The problems in interpretation of arrhythmias in the presence of two hearts are discussed.


Comparison of 12-lead and computer-analysed 3 orthogonal lead electocardiogram in coronary artery disease.

The computer-analysed 3 orthogonal lead system ("3-lead ECG") provides a rapid and consistent interpretation of the electrocardiogram. In 102 patients undergoing selective coronary arteriography, the ability of such a system to predict the presence of absence of coronary artery disease and the site of myocardial ischaemia was compared with that of the conventional scalar electrocardiogram interpreted by cardiologists ("12-lead ECG"). Each system predicted the site of myocardial ischaemia with equal accuracy. The 3-lead ECG was a more sensitive index (3-lead ECG sensitivity=77%; 12-lead ECG sensitivity=70%) but less specific (3-lead ECG specificity=74%; 12-lead ECG specificity=78%). In coronary artery disease, the predictive "index of merit" for the 3-lead ECG was 0-51, compared with 0-48 for the 12-lead ECG. These results provide further justification for the routine use of the 3 orthogonal lead electrocardiogram.


Effect of indomethacin in asthma: evidence against a role for prostaglandins in its pathogenesis.

1. A clinical trial of the effects of indomethacin (200 mg daily) failed to show any objective evidence of improvement in six patients. 2. The same dose failed to inhibit exercise and antigen challenge induced bronchoconstriction, and this was considered to be evidence against the hypothesis that prostaglandins act as chemical mediatros in the pathogenesis of asthma.


Pralidoxime mesylate absorption and heart rate response to atropine sulphate following intramuscular administration of solution mixtures.

1. The oxime pralidoxime mesylate (P2S) and atropine sulphate, alone and mixed, have been administered intramuscularly to forty-four human subjects. Doses of 750 mg and 500 mg P2S and 2.0 mg atropine sulphate were used. 2. The presence of P2S had no significant influence, as judged by effect on heart rate, on the absorption of atropine although there was a tendency for atropine to exert its effects more rapidly when administered mixed with P2S. 3. No significant difference in the rate of uptake of P2S as judged by plasma levels following injection, between a combined (plus atropines) and single (P2S alone) intramuscular injection was found.


The use of isoniazid as a marker to monitor the self-administration of medicaments.

1. Isoniazid was used as a marker to monitor the regularity of drug self-administration in a trial of chemoprophylaxis against natural influenza infection. Two hundred and sixty-two volunteers were treated for five weeks with a synthetic isoquinoline compound (U.K. 2371) or a matching placebo. 2. Five marker tablets containing isoniazid (150 mg) were incorporated into each regimen and their ingestion monitored by testing for acetylisoniazid in the urine. 3. Positive evidence of marker tablet consumption was obtained on 75% of the occasions on which urine samples were requested. The results obtained among the volunteers from each treatment group who returned urine specimens as requested (92%) indicated that they had swallowed at least 81% of their prescribed tablets. 4. The findings of the study suggest that when used in this way isoniazid is a very suitable compound for use on a few occasions for monitoring the self-administration of drugs in clinical trials.


Preliminary assessment of flutiorex, a new anorectic drug, in man.

1 The effects of +/--flutiorex, a new anorectic agent, on food intake, the sympathetic nervous system and the central nervous system were compared to those of fenfluramine and a placebo in a double-blind trial involving six healthy volunteers. 2. Flutiorex exerts a singificant anorectic effect and was shown to be approximately twice as potent as fenfluramine in this regard. 3 Flutiorex induces a definite alpha-adrenergic sympathomimetic stimulation as was shown by a rise in systolic blood pressure and the development of marked mydriasis. 4 Flutiorex is a central nervous system stimulant producing an increase in critical flicker frequency. It does not, however, influence psychomotor coordination as reflected in the pursuit rotor test. 5 Serial determinations of blood and urine levels of flutiorex and its deethylated metabolite, norflutiorex, showed that flutiorex is rapidly absorbed and deethylated, accumulates in large quantities in the tissues and, like its metabolite, is excreted in the urine in very small quantities. Blood levels of norflutiorex appear to remain elevated longer than those fo flutiorex.


Comparison of salmefamol and salbutamol in patients with chronic airways obstruction.

1 Inhaled salmefamol, in doses of 100 mug and 200 mug has been compared with inhaled salbutamol, in a dose of 200 mug, and with placebo in patients with airways obstruction. 2 Both salmefamol and salbutamol are potent bronchodilators with a signficantly superior action over placebo at all times up to 8 h after treatment. 3 The mean peak percentage increases in FEV produced by the three active preparations were similar. The decline from peak values was significantly slower with salmefamol than with salbutamol. Neither drug produced tachycardia.


Plasma concentration of phenylbutazone and its therapeutic effect-studies in patients with rheumatoid arthritis.

1 Phenylbutazone in doses of 50, 100, 200 and 300 mg/day has been given for four periods of 3 weeks to seven patients with rheumatoid arthritis. The trial was double-blind and the order of administration of doses was arranged to eliminate order and carry-over effects. 2 Before the trial and at the end of each period, the patient's responses were assessed by measurement of the duration of morning stiffness, the pain score, paracetamol tablet count, grip strength, digital joint size and articular index. 3 The plasma phenybutazone concentration was measured by gas-liquid chromatography and was also predicted by prior measurement of the phenazone half-life. 4. Compared with the pretreatment period, phenylbutazone had a significant therapeutic effect, as judged by morning stiffness, pain score and articular index, in a dose of 50 mg/day, but no statistically significant differences in effect were seen between the various doses of phenylbutazone. 5 There were no significant coorelations between the plasma concentration of phenylbutazone and any of the clinical assessments. 6 The plasma phenylbutazone concentration agreed closely with that predicted at doses of 50 and 100 mg, but at higher doses the plasma concentration was significantly lower than predicted (P less than 0.05). This may have been due to saturation of the protein binding sites at these doses.


Blood pressure responses to noradrenaline and dopamine infusions in Parkinson's disease and the Shy-Drager syndrome.

Studies of pulse rate and blood pressure responses to graded intravenous infusions of noradrenaline and dopamine were performed on five patients with Parkinson's disease, five with the Shy-Drager syndrome and seven healthy subject. Cardiovascular reflex responses to standing and to the Valsalva manoeuvre were found to be preserved in all patients with Parkinson's disease but to be grossly defective or absent in all with the Shy-Drager syndrome. Each subject received separate intravenous infusions of L-noradrenaline and dopamine, delivered at increasing rates, until a 30% rise in systolic blood pressure was achieved. Heart rate decreased during pressor responses to noradrenaline in control subjects and patients with Parkinson's disease, but increased in those with the Shy-Drager syndrome. Heart rate increased during pressor responses to dopamine in all subjects. Compared to control subjects supersensitivity to noradrenaline was observed both in patients with Parkinson's disease and, to a greater extent, in those with the Shy-Drager syndrome. Subsensitivity to dopamine was observed in patients with Parkinson's disease, but supersensitivity in those with the Shy-Drager syndrome.


The effect of nisoxetine (Lilly compound 94939), a potential antidepressant, on biogenic amine uptake in man.

Preclinical studies with nisoxetine (Compound 94939) (3-[o-Methoxyphenoxy]-N-methyl-3-phenylpropylamine HCl) had shown it to have antidepressant properties and to be almost devoid of anticholinergic activity and depressant effects on cardiac conduction (in contrast to the commonly used tricyclic antidepressants from which nisoxetine significantly differs in structure). Placebo and nisoxetine (10-20 mg b.d. for 7 days) were administered to normal volunteers in a single-bind crossover study. Adverse side effects were minimal. There were no significant changes in heart rate or blood pressure seen when no other drugs were given. The effect of nisoxetine on uptake of biogenic amines was utilized to study its mechanism of action. The transient rise in blood pressure seen after an intravenous bolus of tyramine decreased by one-half to two-thirds while the rise in blood pressure upon continuous noradrenaline infusion was enhanced some two-to eight-fold. Both effects occurred after on dose and were greater with larger doses and chronic administration. In vitro, nisoxetine inhibits 5-HT uptake into platelets. However, platelets harvested from subjects receiving chronic nisoxetine administration did accumulate 5-HT. Plasma concentration of nisoxetine in these individuals was shown to be lower than that needed to block 5-HT uptake. We concluded that nisoxetine, in safe doses, specifically increased the sensitivity of noradrenaline and decreased tyramine responsiveness, presumably by blocking uptake at the axonal membrane. In contrast, in these clinical doses it had virtually no effect on 5-HT uptake into platelets.


Determination of the optimum dose of subcutaneous salbutamol in asthmatic patients.

Saline and salbutamol (250 mug, 500 mug, 750 mug, and 1000 mug) injections were administered under double-blind conditions to seven chronic stable asthmatic patients. The response on the respiratory system (FEV1, FVC) and cardiovascular system (pulse rate, blood pressure and ECG) was monitored for 3 hours. Increasing the dose of salbutamol increased the peak and weighted average effects of FEV1 and pulse rate. The optimum dose, a titration of desired increases in FEV1 and undesirable increases in pulse rate, is 500 mug but doses up to 1000 mug may be administered if necessary.


Comparison of propranolol and practolol in the management of hyperthyroidism.

Twenty-one hyperthyroid patients participated in an 8-week double-blind crossover trial of propranolol and practolol, and the effecte of these drugs on the clinical and metabolic features of the disease were studied. Propranolol was marginally more effective than practolol, as measured by the hyperthyroid diagnostic index and anxiety scale. Propranolol produced a significant reduction in the serum concentration ratio of tri-iodothyronine to thyroxine, compatible with partial inhibition of peripheral deiodination of thyroxine. Adverse reactions occurred more frequently with propranolol than with practolol. In veiw of the efficacy of practoloo, further trials in hyperthyroid patients of newer beta1-adrenoceptor antagonists, preferably without partial agonist activity, are indicated.


Lithium and the antidiuretic hormone.

The effect of lithium on the urine concentrating response to antidiuretic hormone (ADH) and the excretion of ADH has been studied in rats and man. The maximum urine osmolarity following 18 h dehydration and Pitressin (5 u) was decreased in three out of four patients during lithium treatment compared to their response to the same test in the absence of lithium. In a fifth patient, tested only during lithium treatment, the urine remained hypotonic to plasma throughout this test. Lithium increased the excretion of ADH in non-polyuric patients from 9-22 mu/24 h in the absence of lithium to 36-202 mu/24 - during lithium treatment. In four patients with lithium-induced polyuria, a diuretic acting on the distal tubules, clorexolone, reduced the polyuria. Lithium increased urine volume and the excretion of ADH in four rats receiving lithium in their diet. The response to exogenous ADH was decreased during lithium administration.


How double blind is double blind? And does it matter?

In an apparently double blind crossover study, two experienced measurement technicians were able to identify many of the treatment periods. They most often correctly identified aspirin, a drug with prominent effects and side effects. It is argued that in many circumstances it is better to use a blind observer who is not concerned with the giving of treatment or the collection of side effects.


A comparison of slow release with conventional oxprenolol: plasma concentrations and clinical effects.

1 Plasma concentrations of oxprenolol have been compared in six healthy volunteers after 80 and 160 mg doses of a new slow release (SR) oxprenolol preparation, after an 80 ng dose of conventional oxprenolol (CO), and after the second of two 80 mg doses of conventional oxprenolol given 12 h apart. Basal pulse rates and blood pressures, and pulse rates before and after a standard exercise test have been compared after the four active treatments and after a placebo. 2 Peak plasma concentrations of oxprenolol attained after 160 mg of the slow release preparation were similar to the peak concentrations after the single 80 mg dose of conventional oxprenolol. Higher concentrations, however, persisted for much longer after the slow release preparations than after the conventional preparations. 3 Neither oxprenolol formulation had any effect on resting pulse rate or blood pressure in normotensive volunteers. 4 Comparison with placebo showed that the single dose of the conventional oxprenolol produced a significant reduction in exercise induced tachycardia for 8 h whereas the high dose of the slow release preparation produced a similar reduction which lasted for at least 14 hours.


The pharmacodynamics of single doses of prorenoate potasssium and spironolactone in fludrocortisone treated normal subjects.

1 The pharmacodynamic profile of single oral doses of prorenoate potassium (40 mg) and spironolactone (100 mg), as judged by reversal of the effects of fludrocostisone on the urinary electrolyte composition, was compared to that of placebo in a double-blind crossover study in six healthy subjects. 2 Both drugs showed evidence of significant activity in all periods between 2-16 h after treatment, and the time course of their activity was very similar. 3 In the total 24 h period after treatment both drugs significantly increased sodium excretion, the Na/K ratio and the log 10 Na/K ratio over placebo values, and urine potassium concentration was significantly reduced. Changes in urine volume and in potassium excretion were not significant. 4 The responses to prorenoate potassium (40 mg) were not significantly different from those to spironolactone 100 mg), and were very similar as judged by the urine log 10 Na/K ratio, indicating that the two drugs were approximately equiactive at these doses. 5 Reductions in urinary potassium excretion, when expressed in relation to the amount of sodium excreted, were significantly larger after prorenoate potassium than after spironolactone, confirming a qualitative difference in the pharmacological activity of the two drugs which has been reported previously.


Pharmacokinetics of indoramin in man.

1 The fate of oral and intravenous indoramin has been studied after single doses in man using the 14C labelled drug. Plasma concentrations of indoramin have been determined during chronic oral antihypertensive therapy employing a stable isotope dilution assay. 2 Following singleoral dosing the drug is well absorbed and extensively metabolised. Faecal excretion in 72 h accounts for 46% of the administered radioactivity of which approximately 4% is associated with indoramin. Less than 2% of the radioactivity in urine is accountable as the concentration of total metabolites. Peak plasma levels both of drug and metabolites occur 1-2 h after dosing, the maximal lowering of blood pressure occurring at this time. 3 The clearance of indoramin, determined after intravenous administration is of the same order as liver blood flow. In the isolated perfused rat liver, the extraction ratio is 0.98.


The effect on blood pressure of beta-adrenoceptor blocking drugs administered once daily and their duration of action when therapy is ceased.

The control of blood pressure achieved was similar whether pindolol or propranolol was given once or three times daily. When the drugs were ceased the antihypertensive effect lasted for longer than 24 h. There was no rebound hypertension. The full effect of the drug on blood pressure was seen within 24 h of its recommencement. Changes in blood pressure, pulse rate, and plasma renin activity occurred but these were not considered to be causally related. The response of plasma renin activity to posture was ablated when the patients were receiving beta-adrenoceptor blocking drugs.


Hydrallazine or phentolamine as adjuncts to beta-adrenoceptor blockade/thiazide therapy in hypertension.

Ten patients not maximally controlled on an oxprenolo/cyclopenthiazide regimen for moderately severe hypertension were treated in a double blind crossover trial with either hydrallazine (75-150 mg/day) or phentolamine (60-120 mg/day) or placebo in addition to their other therapy. Additional phentolamine therapy did not lower blood pressure significantly when compared with placebo. Additional hydrallazine (75-150 mg/day) produced an approximate 10 mm, Hg fall in diastolic blood pressure, but no significant fall in systolic blood pressure. Pulse rates did not alter with the addition of hydrallazine or phentolamine. In patients who fail to attain optimal blood pressure response to beta-adrenoceptor blocking drugs it is suggested that the addition of hydrallazine is a useful measure.


A trial of brolitene in the treatment of spasticity.

A new anti-spasticity agent, brolitene, has been assessed in patients with spasticity of spinal or cerebral origin. Twenty-seven patients were entered in a double-blind cross-over trial lasting 6 weeks, using a fixed dose of six tablets (1200 mg brolitene) per day. Clinical assessment failed to show any therapeutic effect in the seventeen patients completing the trial, except in one with multiple sclerosis. Ten patients had to be withdrawn from the trial, six while being treated with the active agent.


Effect of amantadine on drug-induced parkisonism: relationship between plasma levels and effect.

Amantadine, administered at a dose of 200 mg/day, antagonized the extapyramidal symptomatology induced by neuroleptic drugs in fifteen psychiatric patients. Steady-state levels were reached within 4-7 days of treatment. Individual plasma levels ranged from 200-900 ng/ml. Apparent plasma half-lives varied from 10-28.5 h with an apparent VD of 200-400 litres. A significant relationship was found between the plasma levels of amantadine and the effects on the extrapyramidal symptomatology. The data suggest a direct effect of amantadine on dopaminergic receptors.


Induction of resistance or enhancement to a transplantable murine plasmacytoma by transfer of non-immune leucocytes.

Newborn mice have a lower spontaneous resistance to the growth of a syngeneic plasmacytoma (MOPC-460) as compared to adult mice. The transfer of different leucocyte populations from non-immunized adult donors to newborn mice influence in a dual way the resistance to MOPC-460 growth, depending on the number of cells transferred. The transfer of a low number of neutrophils, thymus or spleen cells enhances the MOPC-460 takes. Higher numbers of neutrophils, thymus or bone marrow cells induce an effective protenction. By contrast, macrophages over a dose of 1 X 10(4) constantly produce a reduction of tumour growth.


Transformation of epithelioma adenoides cysticum into multiple rodent ulcers: fact or fallacy. A historical vignette.

This historical study has examined the persistent controversy about the propensity of epithelioma adenoides cysticum (EAC) to transform into multiple rodent ulcers, by reviewing cases reported through the years that seemed to support the idea. After focusing on the biological behaviour and natural history of the tumours and comparing them with our present knowledge of the behaviour of EAC, we believe that these cases were incorrectly diagnosed. Rather than EAC, they were probably examples of the naevoid basal cell carcinoma syndrome. The latter syndrome was actually established by the recognition that patients who have multiple rodent ulcers that appear early in life and behave aggressively usually have a constellation of associated developmental defects and that the tumours sould be classified as genetically determined basal cell carcinomas and not as EAC.


Lysosomal hydrolases of the epidermis. 6. Changes in disease.

The activities of 14 acid hydrolases have been measured in normal and diseased human epidermis. Our findings were as follows: (i) Increased hydrolase activity was common in lesions; the clinically uninvolved skin of patients, however, invariably showed normal values. (2) The pattern of change was independent of the nature of the didease, the arylsulphatases and beta-glucosidase usually showing the greatest elevations. (3) The magnitude of the changes differed from disease to disease, being most marked in the lesions of psoriasis. (4) Ichthyosiform erythroderma was exceptional in showing elevated levels of the galactosidases and cathepsins B1 and D. We suggest that (with the exception of ichthyosiform erythroderma) the abnormalities which we have observed may be related to the proliferative rate of the epidermis.


Alternative pathway complement activation:a possible mechanism inducing skin lesions in benign gonococcal spesis.

In order to elucidate the pathogenesis of the skin lesions in 'benign gonococcal sepsis' direct immunofluorescence of an early macular lesion and routine histopathology of a mature papulopustular lesion in a patient with septic gonococcal dermatitis have been performed. Histopathology of the mature skin lesion revelaed a pattenr of 'allergic vasculitis'. Direct immunofluorescence showed exclusively deposits of C3 around and within the capillaries and in the basement membrane zone. No specific IgG, IgM, IgA or C4 deposits could be demonstrated. This, together with serological findings and reports from the literature, suggests an important pathogenetic function for complement, activated through the alternative pathway by means of gonococcal endotoxic lipopolysaccharide, in the pathogenesis of the skin lesions in benign gonococcal sepsis.


A double-blind trial of clomocycline in the treatment of persistent palmoplantar pustulosis.

Sixty patients with persistent palmoplantar pustulosis (PPP) were treated with clomocycline (Megaclor) in a double-blind, cross-over trial in an attempt to establish whether the condition responds to tetracycline. Each patient received 3 months each of clomocycline and placebo in random order. Forty patients completed the trial. Twenty-two failed to respond to either treatment, fifteen improved on clomocycline, two improved on placebo and one placebo and one improbed on both treatments. These results are highly significant (P = 0-003) and suggest that clomocycline may suppress pustulation in some patients. The twenty-two 'non-responders' were compared with the eighteen 'responders' for sex, age, length of history and associated psoriasis but no significant differences were found. Difficulties in assessment and the possiblity of improvement deing due to spontaneous remission are discussed. Further follow-up of both groups suggested that clomocycline used over long periods favourably influenced the course of the disease in the 'responder' group.


Co-operative double-blind trial of an antibiotic/corticoid combination in impetiginized atopic dermatitis.

This double-blind study of an antibiotic coritcosteroid combination, the antibiotic alone and the corticosteroid alone, compared their clinical and microbiological effect in infected atopic dermatitis. Combination therapy reduced the mean scores for infection, inflammation and overall severity to a greater extent than the antibiotic or corticosteroid alone. The clinical and microbiological date are discussed in terms of relevance to clinical use.


Practical applications of the Quantimet 720, an image analysing computer, in the field of investigative dermatology.

Image analysing computers can perform quantitative measurements of epidermal thickness, sebaceous gland volume, and labelling indices of epidermis easily, rapidly and automatically. All these parameters are extremely important in investigative dermatology and this paper describes how they are measured using the Quantimet 720.


The lines of Blaschko: a review and reconsideration: Observations of the cause of certain unusual linear conditions of the skin.

Blaschko's lines are the pattern assumed by many different naevoid and acquired skin diseases on the human skin and mucosae. They were described and drawn by Blaschko 75 years ago. These lines are to be distinguished from other linear patterns such as Voight's lines, Langer's lines, and the lines of innervation of the spinal nerves. They do not follow any known nervous, vascular or lymphatic structures in the skin. The epidermis and its appendageal structures, the melanocytes, the vascular system, and the fatty hypoderm, all, separately or in combination, may be involved in the morphological manifestations which follow Blaschko's lines. Many of the naevoid skin conditions are lifelong (e.g. linear sebaceous naevus, unilateral naevoid telangiectasia); many of the acquired skin diseases (e.g. lichen striatus, linear psoriasis) are of relatively short duration (e.g. 1-2 years). The cause of the distribution pattern is unknown. It is possibly a form of human 'mosaicism' where certain specific cells or groups of cells react differently from other cells due to chromosomal abnormalities. The embryological explanation of Blaschko's lines is not at all clear. Other markers in addition to the skin findings are needed to determine the time  and the nature of the change responsible for these lines. The main purpose of this article is to introduce the concept of Blaschko's lines into the medical, paramedical, and general biological fields of science. In this way, it is hoped that some inter-reaction can occur between those who regularly see Blaschko's lines and those who regularly see and study other chromosomal and embryological abnormalities.


Blast crisis of chronic myeloid leukaemia (CML). II. Cell surface marker analysis of "lymphoid" and myeloid cases.

Fourteen cases of philadelphia chromosome (Ph1) positive chronic myeloid leukaemia in blast transformation have been investigated using cell surface markers. Morphologically eight cases were lymphoid and the remainder myeloid in appearance. All cases were negative with surface markers for thymocytes and T and B lymphocytes. Five of the lymphoid cases reacted with an antiserum specific for acute lymphoid leukaemia )ALL) of non-T non-B type and were also weakly reactive with a lymphocyte reactive antiserum. A sixth patient, whose blast cells were anti-ALL negative (ALL-) at presentation, subsequently developed central nervous system leukaemia with anti-ALL positive (ALL+) blast cells in the CSF. In all cases the leukaemic blast cells showed greatly diminished expression of cholera toxin receptors when compared to granulocytic cells from the chronic phase of CML. This parallels weak or negligible expression of the cholera toxin receptor in ALL and AML. These results suggest that the blastic phase of CML may involve different cellular derivatives of a pluripotential stem cell in which the primary malignant/genetic changes reside. The blast crisis of CML can therefore be heterogeneous with respect to cellular expression and in a significant proportion of patients involves a cell which is by membrane markers and morphological criteria indistinguishable from that seen in the common form of ALL. In these cases the Philadelphia chromosome may be the only distinguishing cellular characteristic.


Effects of terbutaline on myometrial activity, uterine blood flow, and lower abdominal pain in women with primary dysmenorrhoea.

The effects of the selective beta2-receptor stimulator terbutaline (0-25 to 0-5 mg given intravenously) on myometrial activity, local uterine blood flow, and lower abdominal pain were examined during the first day of menstruation in 11 women with severe primary dysmenorrhoea. All had maximum intrauterine pressures between 200 and 350 mm Hg. During uterine contractions of high amplitude or long duration, the local endometrial blood flow decreased markedly, and the patients experienced the most intense pain. Terbutaline inhibited the myometrial activity, increased the blood flow, and relieved the pain.


Serum prolactin and the suppression of lactation.

Bromocriptine (2 bromo-alpha-ergocryptine), stilboestrol, clomiphene citrate, testosterone propionate and a placebo were given to 75 postpartum women for the suppression of puerperal lactation. An additional 15 women who breast-fed their babies served as a control group. Blood samples were taken for the determination of serum prolactin levels by a specific homologous double antibody radioimmunoassay. Concurrently, the clinical effectiveness of the various treatments was assessed. High levels of prolactin were found at the time of delivery. Bromocriptine effectively reduced serum prolactin and prevented lactation; stilboestrol increased serum prolactin and partially suppressed lactation; clomiphene citrate and testosterone propionate both lowered serum prolactin levels and partially suppressed lactation. The placebo showed almost no effect on serum prolactin. It appeared that bromocriptine was the drug of choice in the suppression of puerperal lactation.


Quantitative determination of the number of secondary and tertiary structure base pairs in transfer RNA in solution.

Resonances in the low-field (11-15 ppm) nuclear magnetic resonance spectrum (NMR) of tRNA molecules arise from secondary and tertiary structure base pairs (1 resonance for each base pair) as well as tertiary structure hydrogen bonds. An accurate method for integrating the low-field spectra has been developed and applied to seven different tRNA. In the presence of high levels of magnesium (10 mM free magnesium) the number of resonances (base pairs) per molecule is typically 3-4 more than the number predicted by the cloverleaf model. These results confirm our recent proposal that, under proper conditions, most tRNA exhibit 3-4 tertiary structure interactions in solution, which are also observed in x-ray diffraction studies of yeast tRNAPhe. In addition to common resonances in the 11-15 ppm region, there are common resonances at 10.5 and 9.5 ppm. A critique of methods used to integrate the low-field spectra is given and possible sources of error are indicated. The discrepancy between our present results and previous studies, which indicated that the number of base pairs per molecule was close to the number predicted by the cloverleaf model, can be attributed partly to differences in magnesium concentration and partly to inaccuracies inherent in the integration methods used.


Physical characterization of a ribosomal nucleoprotein complex.

The complex between ribosomal protein L24 and its RNA binding site (that region of the 23S RNA which the protein protects from ribonuclease digestion) has been studied by various physicochemical methods. The RNA is composed of two fragments of about 160 and 140 nucleotides which interact with each other to form the L24 binding site. Circular dichroism spectroscopy suggests that the two interacting fragments have a unique region of secondary structure which is not present in either of the two components alone; hence there are important structural interactions between regions of the RNA which are separated in the primary sequence. Addition of the L24 protein to the RNA site promotes a structural change associated with base unstacking, but with little or no change in the hydrogen-bonded base pairing. Heat activation is not required for complex formation. Thermal denaturation studies reveal a broad featureless transition and the amount of hypochromic change indicates that the RNA site contains less secondary structure than other RNAs such as tRNA and total rRNA. Temperature-jump relaxation measurements on the mechanism of unfolding of the RNA show a concerted melting of the entire secondary and tertiary structure, which is altered upon addition of the protein. A structrual basis for this RNA-protein complex is discussed.


Changes in rotational motion of a cell-bound fluorophore caused by colicin E1: a study by fluorescence polarization and differential polarized phase fluorometry.

The stationary fluorescence polarization and the differential phase delay of the polarized components of the fluorescence of 1-phenylnaphthylamine in Escherichia coli suspensions were measured before and after addition of colicin E1. Both sets of measurements register an increase in the rotational relaxation time of the fluorescent probe when colicin is present. These increases are absent in an E. coli mutant tolerant to colicin E1. The physical interpretation of the changes demands separate estimation of the fraction f2 of the emitting fluorophores that change their properties upon colicin addition and of the rotational relaxation time p2 of this fraction, following the colicin-induced changes. By themselves, the steady state polarizaiton observations permit only the conclusion that f2 must be in the range of 1-0.06 and the change in p2/pi between 1.5 and a value larger than 10. Combination of the data of stationary polarization with those of differential phase fluorometry results in an important reduction in the uncertainty:f2 must be in the range 1-0.33 and the change in p2/pi in the range 1.5-2.5.


Equilibrium measurements of the interactions of guanine nucleotides with Escherichia coli elongation factor G and the ribosome.

The interactions among Escherichia coli elongation factor G (EF-G), guanine nucleotides, ribosomes, and fusidic acid were investigated by a number of physical techniques. Equilibrium dialysis studies demonstrated the existence of a binary EF-G-GDP complex. This complex forms with a stoichiometry of ca 1:1 and an apparent Ka of 2.5 X 10(5) M-1. While no evidence was obtained for the formation of a ribosome-GDP complex, in the presence of ribosomes, the apparent Ka for guanosine diphosphate (GDP) increased 40-fold over that for binding to EF-G alone. Although the apparent Ka increased, the stoichiometry remained ca. 1 mol of GDP/mol of EF-G. An upper limit of 1.3 X 10(7) M-1 was calculated for the Ka for binding of ribosomes to the EF-G-GDP complex. Fusidic acid had no effect on the apparent Ka's for either the EF-G-GDP or EF-G-beta, gamma-methyleneguanosine triphosphate (GMP-P(CH2)P)=ribosome complexes, but markedly increased the Ka for GDP in the EF-G-GDP-ribosome complex without altering the stoichiometry. The apparent Ka for GDP was shown to be dependent upon the fusidic acid concentration. In addition, the rate of GDP exchange into the quaternary EF-G-GDP-ribosome-fusidic acid complex was inversely related to the fusidic acid concentration. All of the data obtained in these studies suggest that the formation and dissociation of complexes involving EF-G and guanine nucleotides is ordered. GDP is the first component to bind to EF-G, followed by the ribosome, and, finally, fusidic acid. This conclusion is consistent with the kinetic mechanism for the hydrolysis of GTP by EF-G and the ribosome proposed in the preceding paper of this issue (Rohrbach and Bodley (1976b). In addition to these binding studies, guanine nucleotides have also been shown to protect EF-G against both limited trypsinolysis and chemical modification by N-ethylmaleimide. These observations offer additional evidence for the existence of a guanine nucleotide binding site on EF-G.


A carbon-13 nuclear magnetic resonance study of hyperactive and hypoactive derivatives of luteinizing hormone-releasing hormone: des-Gly-NH210-[DLeu6]LH-RH ethylamide and des-Gly-NH210-[L-Leu6]LH-RH ethylamide.

The carbon-13 (13C) nuclear magnetic resonance (NMR) behavior of the hyperactive analogue of luteinizing-hormone-releasing hormone (LH-RH), des-Gly-NH2(10)-[D-Leu6]LH-RH ethylamide, has been studied. The spectra are compared with those of the hypoactive des-Gly-NH2(10)-[L-Leu6]LH-RH ethylamide. Spin-lattice relaxation times (T1) of 13C at natural abundance have been obtained for both peptides at 25 and 68 MHz in aqueous solution and used as monitors of flexibility at each carbon atom in the peptide backbone and side chains. The [D-Leu6]-and [L-Leu6]-sub-stituted analogues show equal degrees of freedom within the peptide backbone and side chains. Substitution of the glycine amide moiety in position 10 by an ethylamide group causes an increase in flexibility of the backbone at that position. The increase in flexibility is not transmitted to the adjacent prolyl residue. The C-terminal peptide link at position 10 is proposed to restrict the flexibility of the prolyl residue in position 9, thus maintaining the motional characteristics of the LH-RH peptide backbone in the des-Gly-NH2(10)-[Leu6]LH-RH ethylamide analogues. There were no significant differences in the 13C chemical shifts or T1 values between the hypoactive and hyperactive analogues in aqueous solution which would explain the differences in biological activity. Interaction between receptor and hormone may thus be required to induce, or select, the biologically active conformation of the hormone.


Cooperative and noncooperative binding of pyridoxal 5'-phosphate to tryptophan synthase from Escherichia coli.

An improved purification procedure for the beta2 subunit of tryptophan synthase from from Escherichia coli has led to an essentially pure and stable preparation with a specific enzymatic activity that is 30% higher than the previously reported maximum value. Sedimentation analysis shows that the apo-beta2 subunit is monodisperse and dimeric down to a concentration of 0.02 mg of protein/ml. The binding of pyridoxal 5'-phosphate (pyridoxal-P) to the apo-beta2 subunit and to the alpha2-apo-beta2 complex was studied by equilibrium dialysis and spectroscopic titration. Both the beta2 subunit and the alpha2beta2 complex bind 2 mol of pyridoxal-P with no unspecific binding observable at higher concentrations of pyridoxal-P. The binding of pyridoxal-P to the apo-beta2 subunit is cooperative (Hill coefficient nH = 1.7). The data have been fitted to the Adair equation, yielding the apparent microscopic dissociation constants for the complexes with one and two bound ligand molecules. They differ by a factor of 38, suggesting that the apo- and holo-beta2 subunits have distinct conformations. The binding of pyridoxal-P to the alpha2-apo-beta2 complex is noncooperative with a value of the dissociation constant intermediate between the two values of the beta2 subunit. This finding suggests that the alpha subunit may stabilize a third conformational state of the beta2 subunit.


Nuclear magnetic resonance relaxation time studies on the manganese(II) ion complex with succinyl coenzyme A synthetase from Escherichia coli.

Nuclear magnetic resonance, as well as electron paramagnetic resonance, experiments were carried out in a study of the Mn(II) ion complex with phosphorylated succinyl-CoA synthetase. For high specific activity enzyme samples, there are 3.5 +/- 0.7 metal ion binding sites per enzyme molecule with indistinguishable dissociation constants (KD = 6.9 X 10(-4) M). However, for enzyme samples with a lower specific activity yet equivalent purity, there are 1.6 strong metal ion binding sites (KD = 6.6 X 10(-4) M) and 2.0 weak metal ion binding sites (KD = 4.0 X 10(-3) M), a result that is easily reconciled with the alpha2beta2 subunit structure of the enzyme. Water proton relaxation rate measurements indicate that each strongly bound Mn(II) ion is coordinated to three water molecules. The present results strongly suggest that the existence of nearly 4 high-affinity metal binding sites per enzyme molecule is related to the integrity or configuration of that portion of the molecule which interacts with substrates.


An elastic protein from the cortical layer of the sea-urchin egg.

An elastic protein was isolated from the cortical layer of the fertilized eggs of two species of sea-urchin. Young's modulus of the fiber of the sea-urchin protein was approximately 1-10(7) dyne/cm2. The amino acid compositions of the elastic protein from the two species of sea-urchin eggs were very similar to that of connectin, elastic protein from vertebrate skeletal muscle. The fluorescent antibody against muscle connectin stained the cortical layer of the sea-urchin egg. It appears that the elastic protein is responsible for the elasticity of the egg cortex.


Escherichia coli DNA polymerases II and III: activation by magnesium or by manganous ions.

Escherichia coli DNA polymerases II and III have been extensively studied in vitro when activated with Mg2+. The Mn2+-activated polymerization reactions are considered here, and shown to differ from the Mg2+-activated reactions. The Mn2+-activated DNA polymerase II reaction requires K+ or spermidine, and the effects of monovalent cation and polyamine are additive. In contrast, the Mg2+-activated reaction does not require, but is stimulated by, K+ or spermidine, in a non-additive manner. Under optimal conditions, DNA polymerase II is activated better with Mn2+ than it is with Mg2+, suggesting a physiological role for the Mn2+-activated enzyme. The observed preference for Mn2+ over Mg2+ in reaction kinetics and at high DNA template concentrations suggest that Mg2+ may preferentially activate the associated exonuclease activity. At 29 degrees C, the Mn2+-activated DNA polymerase III reaction is stimulated by K+ and inhibited by ethanol or phosphatidylethanolamine. In contrast, the latter compounds and Triton X-100 increase the initial rate of the Mg2+-activated reaction, whereas K+ inhibits this reaction at all concentrations. The K+ inhibition is reduced at low Mg concentrations when Mn2+ is also present. After stimulating the initial reaction rate, ethanol causes a rapid decrease in the rate of the Mg2+-activated reaction during incubation at 20 degrees C. At 27 degrees C, all surface-active compounds inhibit the Mg2+-activated reaction. Preincubation of the enzyme at 30 degrees C or below with DNA template and divalent cation increases the initial reaction rate, suggesting that formation of an enzyme-divalent cation-DNA template complex occurs as the first step in DNA polymerase III catalysis. The apparent Km at 21 degrees C for gapped calf thymus DNA was 25 muM with Mn2+ and 125 muM with Mg2+ for DNA polymerase III, and 18 muM at 30 degrees C for DNA polymerase II with either Mn2+ or Mg2+. Reactions with poly[d(A-T)] were enhanced by Mn2+ relative to Mg2+, and activity with poly(rA)-poly(dT) was Mn2+ dependent for both enzymes.


DNA repair and recovery in Escherichia coli after psoralen and angelicin photosensitization.

The correlation between DNA repair and recovery of biological functions was studied using three wild type strains of Escherichia coli and two skinphotosensitizing furocoumarins, psoralen and angelicin, which are well known specific reagents of the pyrimidine bases of DNA. In addition to mono-adducts psoralen is able to form a high number of inter-strand cross-links, while angelicin forms only mono-adducts. Both of these damages were repaired, in a short time, in the following way: at first DNA was cut into small pieces that were then rejoined into molecules of normal size, free from cross-links, while the furocoumarin residue was split from DNA almost quantitatively. Recovery of biological functions was studied performing photosensitization experiments in such a manner that the same amounts of psoralen or of angelicin were linked to bacterial DNA. DNA synthesis, tested just after the damage, was inhibited in a similar extent by both drugs. The same bacteria, however, showed a very different colony-forming capacity; angelicin was much less effective than psoralen with a D37 dose about 2.7 times higher. A similar picture was obtained studying DNA synthesis at different times after photosensitization: in the bacteria damaged by angelicin it was restored while no recovery was observed in cells photosensitized by psoralen. These results suggest that both mono-adducts and cross-links can be chemically repaired more or less in a quantitative measure, but that repair of cross-links in much less effective on cell recovery; this behaviour is very probably connected with the different repair mechanisms of mono-adducts and of cross-links.


Ribosomal subunit entry into polysomes in yeast.

The kinetics of entry of newly synthesized 40 S and 60 S ribosomal subunits into yeast polysomes is described. The entry times for 40 S and 60 S subunits were found to be 3 and 8 min, respectively. The kinetics of entry of 40 S subunits into large polysomes is found to be different from the kinetics of entry of 60 S subunits into large polysomes.


Addition by ATP: RNA adenylyltransferase from Escherichia coli of 3'-linked oligo(A) to bacteriophage Qbeta RNA and its effect on RNA replication.

An oligo(A) or poly(A) segment was added in a stepwise fashion to the 3'-end of bacteriophage Qbeta-RNA with the aid of ATP : RNA adenylyltransferase from Escherichia coli. Nearly all RNA molecules, present in the reaction mixture, could be polyadenylated. For tail lengths not exceeding 200 nucleotide residues, the physical properties of Qbeta-RNA-poly(A) were found to be only slightly different from those of the original RNA. The polyadenylated RNA was purifed by affinity chromatography. The properties of Qbeta-RNA with oligo(A) tails of different average lengths were investigated in the in vitro replication reaction. Almost complete abolishment of template activity, even by short oligo(A) stretches, was found. Furthermore, polyadenylated Qbeta-RNA inhibited the normal replication reaction of Qbeta-RNA by removal of host factor HFI, in the same way as does free poly(A).


Mutational change of membrane architecture. Mutants of Escherichia coli K12 missing major proteins of the outer cell envelope membrane.

Mutants of Escherichia coli have been analyzed which miss two of the major proteins of the outer cell envelope membrane. The two proteins I and II, normally are present at high concentrations (about 10(5) copies per cell). In such mutants, as compared with wild type, the phospholipid-to-protein ratio in the outer membrane has increased by a factor of 2.3 causing a considerable difference in density between wild type and mutant membranes. The concentrations of two other major components of the outer membrane, lipopolysaccharide and Braun's lipoprotein, did not change. The protein-deficient mutants do not exhibit gross functional defects in vitro. An increased sensitivity to EDTA and a slight such increase to dodecyl sulfate (but not to deoxycholate or Triton X-100) was observed, loss of so-called periplasmic enzymes was not found, and other differences to wild type are marginal. The mutants can grow with normal morphology. It is not possible, however, to prepare "ghosts" (particles of size and shape of the cell without murein, surrounded by a derivative of the outer membrane, and possessing the major proteins of this membrane) from them. This fact confirms our earlier suggestion that the proteins in question are required for the shape maintenance phenomenon in ghosts, and the mutants reject the speculation that these proteins are involved in the expression of the genetic information specifying cellular shape. Freeze-fracturing showed that in mutant cells, and in sharp contrast to wild type, the far predominant fracture plane is within the outer membrane. The concentration of the well known densely packed particles at the outer, concave leaflet of this fracture plane is greatly reduced. It was not possible, however, to clearly establish that one or the other protein is part of these particles because these ultrastructural differences were not apparent in mutants missing either one of the proteins only. The biochemical and ultrastructural data allow the conclusion that the loss of two major proteins and the concomitant increase of phospholipid concentration has changed the architecture of the outer membrane from a highly oriented structure, with a large fraction of protein-protein interaction, to one predominantly exhibiting planar lipid bilayer characteristics. E. coli thus can assemble rather different outer membranes, a fact excluding that outer membrane formation constitutes a highly ordered or strictly sequential assembly-line process.


Effect of antihistamines and chlorpromazine on the calcium-induced hyperpolarization of the Amphiuma red cell membrane.

1. It has previously been demonstrated that an increase in extracellular Ca2+ conce-tratio- induces a trandient increase in K+ permeability and associated hyperpolarization of the red cell membrane of the giant salamander, Amphiuma meand. This phenomenon is analogous to the Ca2+-induced KCl loss observed in ATP-depleted human red cells and red cell ghosts. 2. Histamine, which enhances the Ca2+-induced K+ loss from depleted human red cells, is without effect on this Ca2+-induced hyperpolarization of Amphiuma red cells. 3. Promethazine (10 muM) and mepyramine (1 mM), which inhibit the Ca2+-induced K+ loss in depleted human red cells, also block the Ca2+-related hyperpolarization of Amphiuma erythrocytes. 4. Chlorpromazine (25 muM), despite being a weak antihistamine, is equally effective in blocking the Ca2+-induced hyperpolarization of Amphiuma red cells. 5. Ionophore A23187 causes a large and sustained Ca2+/K+-dependent hyperpolarization even in the presence of normal (1.8 mM) concentrations of Ca2+. This hyperpolarization is relatively insensitive to chlorpromazine and promethazine. 6. The inhibition of the Ca2+-induced hyperpolarization of the Amphiuma red cell membrane by chlorpromazine and promethazine may berelated to their properties as local anaesthetics.


Nitrate, fumarate, and oxygen as electron acceptors for a late step in microbial heme synthesis.

Nitrate can serve as anaerobic electron acceptor for the oxidation of protoporphyrinogen to protoporphyrin in cell-free extracts of Escherichia coli grown anaerobically in the presence of nitrate. Two kinds of experiments indicated this: anaerobic protoporphyrin formation from protoporphyrinogen, followed spectrophotometrically, was markedly stimulated by addition of nitrate; and anaerobic protoheme formation from protoporphyrinogen, determined by extraction procedures, was markedly stimulated by addition of nitrate. In contrast, anaerobic protoheme formation from protoporphyrin was not dependent upon addition of nitrate. This was the first demonstration of the ability of nitrate to serve as electron acceptor for this late step of heme synthesis. Previous studies with mammalian and yeast mitochondria had indicated an obligatory requirement for molecular oxygen at this step. In confirmation of our previous preliminary report, fumarate was also shown to be an electron acceptor for anaerobic protoporphyrinogen oxidation in extracts of E. coli grown anaerobically on fumarate. For the first time, anaerobic protoheme formation from protoporphyrinogen, but not from protoporphyrin, was shown to be dependent upon the addition of fumarate. The importance of these findings is 2-fold. First, they establish that enzymatic protoporphyrinogen oxidation can occur in the absence of molecular oxygen, in contrast to previous observations using mammalian and yeast mitochondria. Secondly, these findings help explain the ability of some facultative and anaerobic bacteria to form very large amounts of heme compounds, such as cytochrome pigments, when grown anaerobically in the presence of nitrate or fumarate. In fact, denitrifying bacteria are known to form more cytochromes when grown anaerobically than during aerobic growth. An unexpected finding was that extracts of another bacterium, Staphylococcus epidermidis, exhibited very little ability to oxidize protoporphyrinogen to protoporphyrin as compared to E. coli extracts. This finding suggests some fundamental differences in these two organisms in this key step in heme synthesis. It is known that these two facultative organisms also differ in that E. coli synthesizes cytochrome during both aerobic and anaerobic growth, while Staphylococcus only synthesizes cytochromes when grown aerobically.


Some properties of yeast mitochondria prepared by a rapid mechanical procedure.

A method is described for preparing yeast mitochondria rapidly (within one hour) by using the MSK Bronwill Cell homogenizer. Yeast mitochondria obtained by the method exhibit relatively good respiratory controls and ADP/O ratios. The method is convenient for small or large amounts of yeast cells (from 5 to a hundred grams, wet weight) and gave a yield of 3 to 5 mg protein/g wet weight of yeast mitochondria.


[Interaction of dansyl-dipeptidyl-tRNA with E. coli ribosomes].

Dansyl-dipeptidyl-tRNA is found to bind with ribosomes in the presence of polyU much more efficiently than AcPhe-tRNA. 30-80% OF introduced danysl-dipeptidyl-tRNA is in a complex with ribosomes and reacts with puromycin in the presence of 5 mM Mg2+. A significant binding of dansyl-dipeptidyl-tRNA both for acceptor and donor ribosome regions is observed in the presence of 10 mMg2+, unlike AcPhe-tRNA, which is capable of the binding only at 20 mM Mg2+. A peptide transfer from dansyl-dipeptidyl-tRNA on puromycin takes place at 10 mM Mg2+ in the absence of template, while AcPhe-tRNA efficiently interacts with puromycin only at 20 mM Mg2+. The data obtained suggest that the increase of hydrophobity of a peptide residue in peptidyl-tRNA increases its binding in peptidyl transferase of ribosomes.


X-ray small-angle studies of the pyruvate dehydrogenase core complex from Escherichia coli K-12. I. Overall structure of the core complex.

The pyruvate dehydrogenase core complex from E. coli K-12, defined as the multienzyme complex which can be obtained with a unique polypeptide chain composition, has been investigated in solution with the X-ray small-angle technique. The molecular mass of the core complex of 3.78-10(6) daltons verifies the ratio of polypeptide chains of 16:16:16 of the three enzyme components, pyruvate dehydrogenase, dihydrolipoamide transacetylase, and dihydrolipoamide dehydrogenase, present in the complex. In connection with the values obtained for the radius of gyration (156.5A), volume (1.07(7) A3) and amount of solvent associated with the complex (1.03 g/g) a loose packing of subunits in the complex has to be assumed. The maximum diameter of the core complex of 433 A, as determined from the correlation function, corroborates the large extension of the complex. The comparison of experimental and theoretical scattering curves reveals a relatively isometric overall shape of the core complex.


X-ray small-angle studies of the pyruvate dehydrogenase core complex from Escherichia coli K-12. II. Subunit structure of the core complex.

The interpretation of X-ray small-angle data of the pyruvate dehydrogenase core complex from E. coli K-12 reveals the fine structure of the complex. Specific inner surface (7.07-10(-2 A-1), inner surface (7.60 - 10(5) A2), MEAN TRANSVERSAL LENGTH (56.6 A), coherence length (123.5 A), structural factor (1.1), and coherence area (3.27 - 10(4) A2) have been determined as further structural parameters characterizing the colloidal distribution of matter. Fouier transformations of scattered intensity and of structural amplitude have been carried out and show the existence of slightly disturbed spherical symmetry of the complex built up from subunits. The mean diameter of the three different subunit components of about 78 A was determined from the correlation function or from the distance distribution. The number of subunits in the complex was ascertained to be 40. The radial excess electron density distribution shows the arrangement of the core complex from a "core" (formed by the transacetylase components) with a small hole inside and a "shell" (formed by the pyruvate dehydrogenase and dihydrolipoamide dehydrogenase components). Although not representing a unique solution, a lot of model calculations indicate how the complex is arranged from subunits. At each edge of a cubic centre, the edge formed by two chains of transacetylase, two chains of pyruvate dehydrogenase and two chains of dihydrolipoamide dehydrogenase components are arranged according to the best fit. Far-reaching conformity between experimental results and model was established.


Metabolism of branched medium chain length fatty acid. II--beta-oxidation of sodium dipropylacetate in rats.

Catabolic intermediates of sodium dipropylacetate, an anticonvulsant drug, in the urine extracts of the drug-treated rats were examined by the aid of gas chromatography mass spectrometry. Eleven drug-specific peaks were estimated as unmetabolized sodium dipropylacetate, succinic acid, 2-n-propyl-3-hydroxypentanoic acid, 2-n-propyl-4-hydroxypentanoic acid, 2-n-propyl-3-oxopentanoic acid, 2-n-propyl-5-hydroxypentanoic acid, adipic acid, 2-n-propylglutaric acid, dipropylacetic acid glucuronide, propionic acid and 3-heptanone. Administration of sodium dipropylacetate with isoleucine to rats resulted in the disappearance of 2-n-propyl-3-oxopentanoic acid and a considerable decrease in 2-n-propyl-3-hydroxypentanoic acid. These data indicated that beta-oxidation was involved in the metabolism of sodium dipropylacetate as well as glucuronide conjugation and omega oxidation.


Glycogen storage diseases.

Each of 12 types of glycogen storage disease (GSD O-XI) is delineated by clinical, biochemical and histologic features that allow its identification in future patients. GSD II occurs in 2 forms that are not both encountered in the same family. GSD IIa is the infantile fatal form with cardiomegaly, increased cardiac glycogen concentration and cardiac failure; GSD IIb is the adult form with clinically normal heart and normal cardiac glycogen concentration. Nonetheless, the heart muscle of both forms is equally deficient in acid alpha-glucosidase activity, and this raises questions as to the latter's role in the pathophysiology of GSD II. The appearance of hepatocytes in GSD IIa becomes normal after the administration of alpha-glucosidase. Using electron microscopy of uncultured amniotic fluid cells, the prenatal diagnosis of GSD IIa is feasible within one day after the amniocentesis. GSD VI and IX are instances of benign hepatomegaly except when GSD IX and III occur in the same child; one such patient died suddenly at home. There are 2 modes of inheritance in GSD IX: one (GSD IXa) is autosomal recessive, the other one (GSD IXb) is X-linked recessive. In either form the Km of the remaining liver phosphorylase kinase is normal. Both forms of GSD IX have the normal blood sugar response to glucagon, whereas GSD VI does not. Equally, the glucagon tolerance curve is flat in GSD XI although in vitro activity of glycolytic enzymes is normal. The in vivo administration of glucagon in GSD XI is followed by the normal increase of both urinary 3'5'-AMP and hepatic phosphorylase activity. GSD V may have increased activity of muscle phosphorylase kinase. Deficiencies of debrancher, liver phosphorylase and liver phosphorylase kinase can occur singly or in combination. Before any novel treatment of GSD is initiated, one should obtain tissue for the biochemical determination of the exact type of GSD. This is so because the clinical signs may not indicate the type with the necessary precision, and because some types are compatible with normal life and thus may not require therapy, especially if the latter is unproved and potentially dangerous.


Marrow regeneration after mechanical depletion.

The origin of marrow regeneration after mechanical depletion was reinvestigated in mouse chimeras. The results were compatible with the local origin of stem cells from remnants of incompletely removed marrow, but not with their origin from a common precursor of both bone and hemopoietic cell lines. In transplanted femurs depleted by a modified technique of in vivo evacuation of marrow, hemopoietic regeneration failed to occur. The presence of hemopoietic stem cells in the Haversian canals was thus excluded. The demonstration of ample hemopoiesis with minimal bone formation in nondepleted controls in which bone marrow initially became necrotic provided new evidence that osteogenesis was not a prerequisite of hemopoietic regeneration.


Lymphosarcoma cell leukemia: the contribution of cell surface study to diagnosis.

Cell surface immunoglobulin, complement receptor, and spontaneous rosette formation with sheep erythrocytes were investigated in 43 patients with malignant lymphoma, including 13 with lymphosarcoma cell leukemia, and in 59 patients with chronic lymphocytic leukemia. The quantity of immunoglobulin on the lymphocyte surface was estimated from the intensity of fluorescent staining with fluorescein-conjugated anti-immunoglobulin antisera. At least two, and probably three, B cell species could be recognized by cell surface study. Cells from chronic lymphocytic leukemia and diffuse well-differentiated lymphocytic lymphoma had sparse amounts of surface immunoglobulin, while the cells of diffuse poorly differentiated lymphocytic lymphoma had large quantities of this material. Nodular lymphoma probably represented a third B-cell subtype with intermediate amounts of surface immunoglobulin. The lymphocytes of chronic lymphosarcoma cell leukemia exhibited the intense surface staining, which was characteristic of the underlying poorly differentiated lymphocytic lymphoma (diffuse or nodular), and could be readily distinguished from the faint-staining chronic lymphocytic leukemia cells.


A method for the recognition and separation of human blood monocytes on density gradients.

The density distribution of human mononuclear blood leukocytes was studied in order to define the optimal conditions for the separation of monocytes and lymphocytes by isopycnic centrifugation. Under standardized conditions, two populations of cells with partially overlapping, normally distributed densities were consistently found. The cells with the lowest density were recognized as monocytes, using phagocytosis and size distribution analysis as criteria. Since the density of monocytes continuously increased during the centrifugation, optimal separation of monocytes and lymphocytes could only be achieved by limiting the time of centrifugation to 10 min at 2200 g and 4 degrees C. The separation on discontinuous density gradients decreased when the load exceeded 8 X 10(6) mononuclear cells per sq cm. Analysis of the composition of the two cell populations obtained after separation on a three-layer discontinuous gradient revealed that the contamination of the monocytes with lymphocytes was due to the partial overlapping density distributions of both cell types. A small and a large scale method for isolation of monocytes from blood on discontinuous density gradients are presented. Under the described conditions, a preparation of functionally intact monocytes can be obtained which is comparable, both in yield and purity, to those obtained by methods based on surface adherence without the drawbacks of the latter methods.


Evaluation of library service to rural physician associate program students.

Medical students participating in the Rural Physician Associate Program in Minnesota enjoy a unique educational experience, but local library resources are not adequate to support the program. To rectify this deficiency a library service program has been initiated, with the computer-based bibliography and photoduplication the principal service elements. Because of positive evaluation by the students, the service will be continued and expanded.


A randomized controlled trial of vitamin C in the prevention and amelioration of the common cold.

A randomized controlled trial of the effect of 1 g ascorbic acid per day in the prevention of the common cold was conducted on 688 adult women. There is evidence of a small reduction by vitamin C in the mean number of chest colds, but no evidence of any effect on simple colds. The existence of a subgroup of vulnerable women in the community who benefit from vitamin C was considered but further examination of the data gives no support to this conclusion.


Degree of physical handicap, education, and occupation of 51 adults with spina bifida.

51 adults with spina bifida, aged between 18 and 56 years, resident in South Wales, were interviewed in their home. Although only four had obvious hydrocephalus, one-third of them were severely handicapped and a further 40% had moderate handicap. Over half of them had had their secondary education in a normal school, with the remainder having special schooling or home tuition. Seventy per cent of the series was in normal, full-time occupation, including half those severely handicapped. Those in work were largely in managerial/technical, clerical, and light manual occupations. It is concluded that extendance and training, followed by special job placement, would help to integrate them into the community. These patients show that, in the absence of mental retardation, even severe physical handicap is no bar to normal occupation and that paralysis and incontinence alone are probably not valid selection factors for or against 'aggressive' treatment for spina bifida.


Creativity and schizophrenia: an equality of empirical constructs.

The possibility that schizophrenia and creativity are two aspects of the same process is discussed, and parallels between different types of schizophrenia and different factors of creativity are sought. The discussion begins at a theoretical level,but its main thrust is an analysis of the research literature at an empirical level. Similarities are pointed out between tasks used for the purpose of operationally defining the schizophrenic 'deficit' and tasks used to define creativity. Some evidence is found for different subtypes of schizophrenics exhibiting different factors or types of creativity.


A computer-based technique for measurement of renal parenchymal area on intravenous urograms.

Accurate measurement of the renal parenchymal area of intravenous urograms is discribed using a graphic tablet with a pressure-sensitive surfact linked on-line to a computer. The area outlined on the tablet is immediately computed and shown in square centimetres on a television screen and on a data print-out. The renal areas of 22 patients' urograms were studied before the three months after renal stone removal under local hypothermia. Renal function was measured by creatinine clearance. Conventional measurements of renal length, width and area were also performed for comparison. Results confirmed that while overall kidney size was reduced following operation, the parenchymal area and creatinine clearance were unaltered. This computer-based technique is simple to perform, quick and accurate, and provides quantitative information on intravenous urograms.


Liver and gall-bladder imaging with technetium-99m dihydorthioctic acid and technetium-99m pyridoxylidene glutamate-a study in the young pig.

Seventeen scans on ten young pigs were performed after injection of Technetium-99m labelled dihydrothioctic acid (99Tcm-DHT) and Technetium-99m labelled pyridoxylidene glutamate (99Tcm-PG) using a gamma-camera. Sequential images of the liver, gall-bladder and intestine were observed in all healthy animals. 99Tcm-DHT produced the clearer liver images, whereas 99Tcm-PG produced more rapid and intense gall-bladder images. Analysis of hepatic bile in three animals also suggested a more rapid and higher concentration of 99Tcm-PG than 99Tcm-DHT (36% vs. 4% of the injected dose over two hours). Bowel images were not seen in an animal that had undergone exicision of the extrahepatic biliary tract, but scans performed after hepaticojejunostomy demonstrated intestinal transit of isotope. This study shows that the hepatobiliary system can be easily imaged using Technetium-99m labelled compounds which are excreted into bile. These agents may be useful in the diagnosis of obstructive lesions of the extrahepatic biliary tract of adults and infants.


Graded compression for preventing deep venous thrombosis.

The physiological effects of static compression of the leg have recently been reinvestigated. Graded compression extending from the ankle to the upper thigh produces the maximum increase in velocity of femoral vein blood flow and the maximum decrease in clearance times of contrast media and radioisotopes from the deep veins of the calf. This type of compression may be easily produced by a specially designed elastic stocking. Graded compression was used in a controlled clinical trial of 98 patients undergoing major operations to assess its effect on isotopically diagnosed deep vein thrombosis. The incidence of deep vein thrombosis was 49% in the control group and 23% in the treated groups. No complications were caused by the stockings. Carefully designed and correctly applied static compression is a safe and effective method of reducing the incidence of deep vein thrombosis.


Changes in nystagmus on raising body temperature in clinically suspected and proved multiple sclerosis.

Electronystagmography was used to record the appearance or alteration of nystagmus after raising the body temperature by a heat cradle. Nystagmus was increased or provoked in 13 out of 15 patients with clinically proved multiple sclerosis, in eight out of 12 suspected cases, but in no normal controls. No positive results were obtained in 12 patients with other neurological diseases, even when nystagmus was part of the clinical picutre. The technique is simple to use and may have a role in the diagnosis of multiple sclerosis.


Stimulation-dependent depression of readily releasable neurotransmitter pools in brain.

Previously accumulated GABA was released from isolated forebrain synaptosomes with repeated calcium stimulation in elevated-potassium medium. Fractional release (calcium-dependent) in response to a second calcium pulse (90-120 sec later) was depressed to approximately 60% of initial release. Neither initial GABA release nor the subsequent depression of release was affected by variations in the labelling duration. Stimulation-dependent depression of labelled GABA and norepinephrine release was demonstrated from both cerebral cortex and cerebellum synaptosomal preparations. In addition, depression resulted from prior stimulation in the presence of veratridine, A23187 or elevated-potassium. Although release of previously accumulated GABA was depressed by calcium stimulation, the release of GABA accumulated between stimulations was not. Release of this recently accumulated GABA was indistinguishable from the initial release of previously accumulated GABA and larger than the subsequently depressed release from the previously accumulated pools. These data imply (1) that the depressed release resulted from a decrease of available transmitter in pools that support secretion processes, (2) that depressed release did not result from a depression of stimulus-secretion coupling processes, and (3) that transmitter accumulated subsequent to release events is released preferentially to transmitter accumulated prior to the intervening stimulation.


Immunocytochemical localization of glutamate decarboxylase in rat substantia nigra.

L-Glutamate decarboxylase (GAD, EC 4.1.1.15), the enzyme which catalyzes the alpha-decarboxylation of L-glutamate to form gamma-aminobutyric acid (GABA), was localized both light and electron microscopically in rat substantia nigra by an immunoperoxidase method. Large amounts of GAD-positive reaction produce were seen throughout the substantia nigra in light microscopic preparations, and it appeared to be localized in punctate structures that were apposed to dendrites and somata. Electron microscopic studies revealed that most of the axon terminals in the substantia nigra were filled with GAD-positive reaction product and formed both axodendritic and axosomatic synapses. Many dendrites were extensively surrounded by GAD-positive terminals which most commonly formed symmetric synaptic junctions, although some formed asymmetric synpatic junctions. The results of this investigation are consistent with biochemical, pharmacological and physiological data which have indicated that neurons of the neostriatum and globus pallidus exert a GABA-mediated, postsynaptic inhibition upon the neurons of the substantia nigra. These findings provide another example in the vertebrate central nervous system where Golgi I projection neurons are inhibitory and use GABA as their neurotransmitter.


Microscope-enlarger for macrophotography of histological sections.

A microscope-enlarger is described which can be used to produce 20 cm by 25 cm negatives of histological sections at magnifications up to 1,000 diameters, without loss of image quality or reduction of resolution. Standard flat-field microscope optics are used, and the apparatus is adjustable for Koehler illumination. Various microscope components (nosepiece, condenser carrier, etc.) are mounted upon carriers which ride upon a rigid vertical track. A 20 cm by 25 cm film holder is placed upon the base of the device, and illumination is controlled by a photographic timer. The microscope-enlarger has been used to produce large format negatives of Nissl-stained sections of the barins of sea lamprey larvae and to trace the course of Golgi-impregnated and cobalt-filled cells. Further uses of the device in autoradiographic and histochemical studies are mentioned.


Modification of rabbit head holder to increase speed and accuracy of stereotaxic surgery.

Modification of a rabbit stereotaxic head holder is described. The changes are designed to reduce the amount of time required to establish the horizontal zero plane and to increase the accuracy of stereotaxic surgery by providing greater instrument stability.


An ultrastructural analysis of protoplast-spheroplast induction in Cryptococcus neoformans.

Protoplasts-spheroplasts of a human isolate of Cryptococcus neoformans were prepared using the gut enzyme of Helix pomatia. The induction process, as studied by transmission electron microscopy, occurred in two stages. Early in the induction process, protoplasts-spheroplasts emerged from whole cells through a break in the cell wall-capsule envelope. Later, a gradual dissolution of the entire cell wall occurred releasing the intact protoplast-spheroplast. A comparison of protoplasts-spheroplasts with normal untreated cells revealed that the degree of cellular vacuolation as well as the resolution of cellular organelles was similar.


Influence of temperature on growth of lipopolysaccharide-deficient (rough) mutants of Salmonella typhimurium and Salmonella minnesota.

Smooth strains of Salmonella typhimurium and S. minnesota, and chemotypes Ra, Rb, and Rc, which are deficient in lipopolysaccharide components of the somatic side chains and outer core region, grow normally on nutrient agar and nutrient broth up to 45 degrees C. However, most mutants with defects in the heptose region of the LPS (chemotypes Rd2 and Re) do not grow on this medium at 42 degrees C or above; a few grow at 42 degrees C but not at 45 degrees C. In liquid medium (nutrient broth, or phosphate minimal medium), growth, measured as turbidity or as colony-forming units, stops 60 to 90 min after shift from 30 to 42 degrees C; DNA and protein synthesis cease at the same time. Growth does not reoccur at 42 degrees C; protein synthesis and growth reinitiate upon shift to 30 or 37 degrees C. Growth cessation does not alter cell morphology in the phase-contrast microscope. Growth of heptose-deficient strains at 42 degrees C in nutrient broth is restored by MgCl2 (0.5 mM), NaCl (50 mM), or sucrose (100 mM). Sensitivity to smooth-specific and rough-specific phages, and analysis of LPS composition, indicate that heptose-deficient mutants grown at temperatures from 30 to 45 degrees C, and in the presence or absence of high salt, do not contain heptose or O-specific sugars in their LPS.


Accelerated detection of lymphocytic choriomeningitis virus in diagnostic specimens.

Lymphocytic choriomeningitis virus could be demonstrated earlier in mice inoculated with clinical specimens if the mice were sacrificed before they appeared sick for examination by the fluorescent antibody technique. In the procedure, the optimal route for inoculation was intracerebral and the best organ tested for staining was the brain.


The respiratory metabolism of Mycobacterium lepraemurium.

The respiratory metabolism of Mycobacterium lepraemurium isolated from Sprague-Dawley rats lepromata using several substrates was investigated. None of the intermediates of the glycolysis cycle as well as of the tricarboxylic acid cycle except succinate was oxidized by purified whole suspensions of M. lepraemurium. Likewise, many sulfur compounds such as cystine, thiourea, thioacetate, thiodiglycol, mercaptoact and some sulfhydryl compounds, e.g., cysteine, dithioerythritol, dithiorthritol, and penicillamine were readily oxidized by murine bacillary suspensions, whereas thioglycolate, thioglucose, and reduced glutathione were oxidized at a slow rate. Succinate was not or was very poorly oxidized by normal cells probably because of impermeability of the cell wall but the addition of succinate to the cell suspensions frozen for 1 min at -40 degrees C considerably enhanced oxygen uptake over the endogenous value. The oxidation of succinate was unaffected by inhibitors rotenone, atabrine, and amytal but was markedly inhibited by thenoyltrifluoroacetone, antimycin A, 2-N-heptyl-4-hydroxyquinoline-N-oxide, and cyanide. The thiol-binding agents, p-hydroxymercuribenzoate and N-ethylmaleimide were also effective inhibitors of succinate oxidation but the process was not affected by uncouplers dinitrophenol, dibromophenol, pentachlorophenol, and carbonyl-cyanide-m-chlorophenylhydrazone. The results indicated that succinate oxidation by M. lepraemurium was mediated by oxidative enzymes involving an electron transport chain with oxygen as the terminal electron acceptor.


Respiratory activity as a determinant of radiation survival response.

Respiration is depressed in irradiated bacteria reaching a minimum level in most strains at 1-3 h after exposure when incubated in growth medium. Since a delay in response is observed, direct action on respiratory enzymes is unlikely. The dosage response of respiration varies widely in the strains studied with Do's from 15 kR for Escherichia coli BS-1 to 1200 kR for Micrococcus radiodurans. All strains exhibit two-component dosage-response curves. Escherichia coli BS-1 uniquely possesses a positive-sloped second component suggesting a major disruption of respiratory control. A relationship exists between the responses of respiration and survival to a 50-kR exposure in the strains studied. When E. coli B/r is grown in 0.4% glucose reaching a pH of 5.3, a condition known to increase radiation survival considerably, a large increase in radioresistance of respiration is found. 2-Mercaptoethylamine (MEA), a radioprotective agent, also produces proportionate radioprotection of respiration and survival. In M. radiodurans protection is afforded to respiration at doses which produce no measurable effect on survival. These facts suggest that respiration is a major factor in influencing cell survival and may be the principal mechanism through which chemical agents modify radiation response.


Surgical treatment of hydatid disease of the liver.

Hydatid disease in southern Ontario is becoming more frequent because of infection in the large immigrant population. Review of 25 cases of hydatid disease of the liver has clarified the clinical features, diagnostic approach and methods of treatment. The commonest presenting symptoms were pain, mass or hepatomegaly, and jaundice. Diagnosis was confirmed, and cysts were localized, by Casoni skin testing, hepatic scanning and angiography. Surgical treatment consisted either of resection, excision or enucleation, and evacuation of the cyst. Two patients were treated by left lateral segmental resection, 6 by either wedge excision of the cyst or enucleation, and 14 by evacuation of cyst contents with or without drainage with the aid of a technique designed to prevent spillage of cyst contents at operation. None of the 14 treated by means of this technique developed recurrent disease, but in 4 of the patients treated by wedge excision or enucleation the cyst contents spilled at operation, resulting in recurrent disease in 2. Controlled cyst evacuation, with tube drainage for infected cavities and those communicating with the biliary tract is the recommended form of treatment in the management of hepatic hydatid disease.


Pilonidal sinus of the umbilicus.

Only 15 cases of pilonidal sinus of the umbilicus have so far been reported. A 16th case is described; it supports the theory of acquired origin of the disease. The case fulfilled the criterion for pilonidal sinus--the 36-year-old man had a hair in the infected umbilical cyst. The cyst and umbilicus were excised. The umbilicus was not reconstructed because of the danger of recurrence. It is recommended that a careful search be carried out for hair in all patients with an infected umbilicus.


Malignant lymphoma of the thyroid gland.

Malignant lymphoma of the thyroid gland is a rare entity; only 200 cases have been reported to date since 1960. Four patients with this disease presented at the Kingston clinic of the Ontario Cancer Treatment and Research Foundation. Those with localized malignant lymphoma, particularly the histiocytic types, responded favourably to resection of as much of the tumour as possible and subsequent local radiation with cobalt-60 telecurietherapy (3000 to 4000 rads in 3 to 4 weeks). The results of local radiation alone after a biopsy in patients with inoperable localized diseases are encouraging; it is possible, but not yet established, that some of these patients are cured. It has been suggested that the tumour is dependent on thyroid-stimulating hormone but conclusive evidence is not yet available.


Early medicine and surgery in Calgary.

The medical history of the Calgary area can be divided into three periods: the early period before the coming of the North West Mounted Police in 1874, the middle period from 1875 to 1905, during which Fort Calgary was built and the first surgeons settled in the West, and the third period from 1905 to the present. George Alexander Kennedy was the first surgeon of the middle period. He encouraged proper sanitation, fresh air, and avoidance of cold, damp and dirt. He recommended special treatment for various systemic diseases, used chloroform in October 1880 and was known to have treated skull fractures, extradural hemorrhages, prostatic obstruction, postabortion hemorrhage, ascites and pleural effusion. Henderson, Brett, Lindsay, Rouleau, Lafferty and Mackid were the other six pioneer surgeons of the middle period. Mackid's son Ludwig took over his father's practice after studying in Europe and the United States. When he died in November 1975 at the age of 93, the last link with the pioneer surgeons of Calgary was broken.


Epidemic shigellosis on a worktrain in Labrador.

An epidemic of shigellosis occurred on a worktrain in western Labrador in October 1974. During the outbreak 62 persons out of a crew of 91 became ill, 11 having recurrent illness; 14 were hospitalized. Epidemiologic analysis with laboratory confirmation implicated unchlorinated and contaminated lake water as the source of the epidemic. Faulty design of water storage tanks perpetuated the use of contaminated water; hence a second wave of illness occurred. The tanks were then thoroughly drained, cleaned and repaired. Many deficiencies in sanitation measures (most of which have since been rectified) were noted at the site of the epidemic as well as at other locations along the railway. Careful sanitation controls are essential in rapidly developing areas of northern Canada.


Extranodal presentation of non-Hodgkin's lymphomas in the testis.

The clinical and pathologic features of six patients, each of whom exhibited a testicular mass as the first sign of a lymphoma, are discussed. All underwent extensive staging procedures. Retroperitoneal lymph nodes and bone were frequent sites of extratesticular involvement early in the disease. Later widespread dissemination to multiple organs occurred in five of six patients. CNS involvement was a prominent feature of advancing disease. One patient was apparently cured by orchiectomy alone. Although the others exhibited partial responses to chemotherapy and radiation, the disease was fatal to all of them within a year of orchiectomy. Early, aggressive systemic treatment of these patients appears necessary.