Characterization and phenotypic control of the cytochrome content of Escherichia coli.

1. Electron-transport particles derived from Escherichia coli grown aerobically contain three b-type cytochromes with mid-point oxidation-reduction potentials at pH7 of +260mV, +80mV and -50mV, with n=1 for each. The variation of these values with pH was determined. 2. E. coli develops a different set of b-type cytochromes when grown anaerobically on glycerol with fumarate or nitrate as terminal electron acceptor. Electron-transport particles of fumarate-grown cells contain b-type cytochromes with mid-point potentials at pH7 of +140mV and +250mV (n=1). These two cytochromes are also present in cells grown with nitrate as terminal acceptor, where an additional cytochrome b with a mid-point potential of +10mV (n=1) is developed. 3. The wavelengths of the alpha-absorption-band maxima of the b-type cytochromes at 77K were: (a) for aerobically grown cells, cytochrome b (E(m7) +260mV), 556nm and 563nm, cytochrome b (E(m7) +80mV), 556nm and cytochrome b (E(m7)-50mV), 558nm; (b) for anaerobically grown cells, cytochrome b (E(m7) +250mV), 558nm, cytochrome b (E(m7) +40mV), 555nm and cytochrome b (E(m7) +10mV), 556nm. 4. Cytochrome d was found to have a mid-point potential at pH7 of +280mV (n=1). 5. Cytochrome a(1) was resolved as two components of equal magnitude with mid-point potentials of +260mV and +160mV (n=1). 6. Redox titrations performed in the presence of CO showed that one of the b-type cytochromes in the aerobically grown cultures was reduced, even at the upper limits of our range of electrode potentials (above +400mV). Cytochrome d was also not oxidizable in the presence of CO. Neither of the cytochromes a(1) was affected by the presence of CO.


Abnormal ribosome assembly in a mutant of Escherichia coli.

The mutant strain, 15--28, of Escherichia coli accumulates ribonucleoprotein ('47S') particles that were previously shown [Markey, Sims & Wild (1976) Biochem. J. 158, 451--456] to be an unusual intermediate in the assembly of 50S ribosomal subunits...


Effect of estrogen on natural killer cells.

Treatment of mice with sustained high levels of betarestradiol leads to a reduction in natural killer cell activity and genetic resistance to bone marrow transplantation. The loss of natural killing does not seem to result from either humoral or immune suppression. Natural killer cells are thought to depend on the bone marrow, and it is notable that estrogens reduce natural killing at approximately the same time that they produce a loss of ma-row due to osteoproliferation. Similarly, mice with congenital osteopetrosis are deficient in natural killing. However, changes in natural killing during and after treatment with estrogen do not correspond directly to changes in marrow volume. Estrogens are known to exacerbate spontaneous autoimmunity in NZB/NZW mice. The relationship between this  effect and the effect of estrogen on natural killing is not clear. When natural killing is lowered in NZB/NZW mice by the in vivo administration of 89Sr, autoimmunity is reduced.


Sex differences in response to hepatitis B virus. III. Responses to HBV and sex of donor and recipient in kidney and bone marrow transplantation.

We proposed the hypothesis that there is an antigen on the hepatitis B virus (HBV) that cross-reacts with a male associated antigen to explain four observations: 1) sex differences in the responses to HBV infection, 2) sex differences in the prevalence of chronic liver diseases associated with hepatitis B, 3) the association of parental responses to HBV with the sex ratio (at birth) of their offspring, and 4) the relation of kidney graft survival with the combination of anti-HBs in the recipients and the sex of the organ donor. Patients with aplastic anemia treated with bone marrow transplantation from HLA identical sibling donors were studied to further test this hypothesis and the results provide additional support. Cross reactivity of HBsAg with H-Y antigen, however, has not been demonstrated.


Endocarditis caused by Salmonella enteritidis.

A case of endocarditis caused by Salmonella enteritidis is reported in a 20-year-old African woman. This is only the fourth published case. The development of this rare infection in the patient reported here probably resulted from a reduction in immunity caused by pregnancy and a past splenectomy.


Randomised multicentre trial of early mobilisation after uncomplicated myocardial infarction.

In a multicentre trial 742 patients in 13 hospitals in Wales were randomly allocated on the fifth day after uncomplicated myocardial infarction to be mobilised on the fifth or the tenth day. The trial shows no difference in first year mortality, nor in morbidity assessed after a median period of 13 months. Follow-up after one year suggests an unexplained lower mortality during the second and third years in the late mobilisation group.


Postoperative serum cholinesterase activity following successful renal transplantation.

For 6 months after renal transplant serum cholinesterase concentrations were measured in 10 patients. The value decreased in the first 15 days after operation, but was normal thereafter. Liver function tests were normal throughout the study; the cholinesterase changes were independent of immunosuppressive therapy.


Glycopyrrolate as a premedicant: comparison with atropine.

A double-blind comparison of glycopyrrolate with atropine as the anticholinergic component of premedication was made in 200 patients undergoing minor or intermediate surgical procedures. Glycopyrrolate was associated with a smaller increase in heart rate, but there was no difference between the drugs in respect of cardiac arrhythmia, change in arterial pressure, control of secretions in the upper respiratory tract, frequency of nausea and vomiting after operation or subjective well-being of the patients.


Prevention of diazepam-induced thrombophlebitis with cremophor as a solvent.

In 104 patients undergoing anaesthesia of short duration, two different solvents, propylene glycol and cremophor, were compared in a double-blind trial. Diazepam 10 mg in a coded solution was injected into a superficial vein of the hand using a small-gauge needle. The vein was examined after 14 days. The frequency of thrombophlebitis with propylene glycol was 62.2% and with cremophor 3.4% (P less than 0.001). The frequency of pain on injection was also in favour of the new solvent (P less than 0.001). The possibility of anaphylactic reactions accredited to cremophor, however, restricts the use of the new injection.


The aspirin-ibuprofen interaction in rheumatoid arthritis.

1 This was a double-blind crossover trial of ibuprofen and soluble aspirin against each drug alone and against placebo in patients with rheumatoid arthritis. Two dosage regimes were tested. 2 A weak clinical additive effect was demonstrated between soluble aspirin and ibuprofen in patients with rheumatoid arthritis using moderate (1600 mg ibuprofen and 3.6 g aspirin daily) but not low (800 mg ibuprofen and 2.4 g aspirin daily) dosages of both drugs. 3 A significant correlation between clinical efficacy and serum ibuprofen but not salicylate level was found in the single drug periods of the trial. 4 No consistent effect of ibuprofen administration on serum salicylate levels was found. 5 Concurrent salicylate administration produced significant lowering of serum ibuprofen levels without affecting elimination half-lives of the drug.


Immunotherapy using BCG during remission induction and as the sole form of maintenance in acute myeloid leukaemia.

Thirty-two adults with acute myeloid leukaemia (AML) were randomized to receive, from the time of diagnosis, either chemotherapy alone (C group) or chemotherapy plus Bacille Calmette-Guérin vaccine (BCG) (C+I group). After remission induction and consolidation, chemotherapy was stopped in both groups but BCG was continued in the C+I group. The overall survival of the C+I group was significantly increased (P less than 0.05). There was no significant increase in the duration of first remission in the C+I group (0.05 less than P less than 0.1) nor in the time from first relapse to death (0.05 less than P less than 0.1). There was no significant difference in the incidence of first or second remissions, and the time taken to enter remission did not differ significantly between the two groups. Comparison with the results of other trials suggests that the use of maintenance chemotherapy in addition to immunotherapy produces longer remissions. Five patients in the C group developed leukaemic central-nervous-system (CSN) involvement, in comparison with none in the C+I group. CNS relapse did not produce a significant decrease in remission length (P greater than 0.1) but reduction in survival after CNS relapse was highly significant (P = 0.001). These results suggest that administration of BCG from an early stage in the treatment of AML may protect the CNS against leukaemic infiltration and therefore serve as a simple, innocuous form of CNS prophylaxis.


Studies on fibronectin in the skin. I. Indirect immunofluorescence studies in normal human skin.

Fibronectin is a glycoprotein mediating contact between cellular elements and collagen. As judged by indirect immunofluorescence studies fibronectin is abundantly present in normal human skin. It is located in the dermo-epidermal junction area, in the papillary and reticular dermis, about epidermal appendages (pilosebaceous units and eccrine sweat glands) and in the vascular and neural structures.


Juvenile dermatitis herpetiformis: an immunoelectron microscopic study.

Three children with persistent maculopapular and urticarial lesions and vesicles at the predilection sites of dermatitis herpetiformis (DH) were shown to exhibit typical granular, papillary IgA and C3 deposits in the tips of the dermal papillae, as demonstrated by direct immunofluorescence. By immunoelectron microscopy, the IgA deposits were associated with the microfibrils of the elastic fibres as has been described in DH of the adult. C3 deposits were scattered throughout the papillary dermis. Despite the similarity of the clinical appearance, history with regard to gluten sensitive enteropathy (GSE) varied in these three cases. In one child, the skin lesions appeared following faults in the gluten free diet on which he was kept for coeliac disease. Another child developed the skin lesions during a gluten free diet which was not strictly followed; no recurrences of gastrointestinal symptoms accompanied the eruption of DH. In the third case, no evidence for GSE in patient's history or in jejunal biopsies was present at the time of onset of DH.


Corticosteroids, aurothioglucose and soybean trypsin inhibitor do not prevent pemphigus antibody-induced acantholysis in vitro.

Hydrocortisone, triamcinolone acetonide, aurothioglucose and soybean trypsin inhibitor were added to normal human skin explants cultured with IgG from pemphigus serum to determine if acantholysis could be prevented. At the therapeutic concentrations used none of these compounds prevented binding of the autoantibody to the epidermal target cells, and none prevented acantholysis. These experiments support the concepts that the pemphigus antibody alone is responsible for producing the acantholytic lesions of pemphigus, that the therapeutic effectiveness of steroids and gold salts is probably due to their ability to reduce serum autoantibody titres and that pemphigus acantholysis is probably not caused by a serine proteinase.


Immunofluorescence studies on eosinophilic granulocytes.

Immunofluorescence techniques were used to find out whether immunoglobulins (Ig) and complement (C3) determinants are present on the membrane of eosinophilic granulocytes in atopic patients and in patients with an allergic contact dermatitis. Normal healthy individuals served as controls. The studies were performed with eosinophilic granulocytes in suspension and in thin cell layers. The demonstration of the presence of cytoplasmic Ig and C3 in eosinophilic granulocytes was carried out in skin specimens taken 20-30 min after injection of the antigen and in specimens taken from positive patch tests 48 h after application of the antigen. No immunoglobulins or C3 determinants could be demonstrated on the membrane of eosinophilic granulocytes in the patients or the healthy controls, when the suspension methods were used. However, in thin cell layers and in skin sections the eosinophilic granulocytes showed a positive fluorescence of the cytoplasm after having been exposed to various conjugates and a FITC solution. It is concluded that the commonly used immunofluorescence techniques tend to give non-specific staining results, most likely due to reactivity of the FITC marker of the conjugates with basic proteins present in the cytoplasm of the eosinophilic granulocyte.


Photochemotherapy (PUVA) of psoriasis using 3-carbethoxypsoralen, a non-carcinogenic compound in mice.

The carcinogenic risk of photochemotherapy (PUVA) with bi-functional furocoumarins such as 8-methoxypsoralen (8-MOP) which form cross-links in cellular DNA has initiated a search for active but less hazardous psoralens. A new compound, 3-carbethoxypsoralen (3-CPs), studied in the yeast Saccharomyces cerevisiae (eukaryote), has been shown to be very photoactive on DNA and to form only mono-additions to DNA. These lesions appear to be more easily repaired than the cross-links induced by 8-MOP. 3-CPs produces less nuclear genetic events such as nuclear mutations and mitotic crossovers, but more cytoplasmic 'petite' mutations (damage to mitochondrial DNA) than 8-MOP. In mice it was demonstrated that after local or intra-peritoneal administration, in contrast to 8-MOP, 3-CPs is non-toxic, non-erythematogenic, and non-carcinogenic. A study of ten psoriatic patients had shown that local applications of 3-CPs plus UV-A exhibit about the same therapeutic activity for the clearing of psoriatic lesions as local treatment with 8-MOP plus UV-A, but without any localized hyperpigmentation.


Lesions induced by trauma in pemphigoid.

Three patients are described with pemphigoid (two with typical adult type and one with juvenile pemphigoid) in whom bullous lesions had clearly been induced by the trauma of scratching. In two patients this phenomenon occurred during the first few weeks of systemic corticosteroid treatment at a time when other lesions were resolving or had completely healed. Although lesions induced by trauma are not usually of great clinical importance, epidermolysis bullosa acquisita may represent a variant of pemphigoid in which trauma-induced lesions predominate. Induction of pemphigoid lesions by trauma may prove a useful method of studying early immunopathological events.


Myeloproliferative disorders terminating in acute micromegakaryoblastic leukaemia.

Two cases of myeloproliferative disorder--one of myelofibrosis with agnogenic myeloid metaplasia and one of chronic granulocytic leukaemia terminating in acute micromegakaryoblastic leukaemia--are presented. The clinical course is described, and results are reported of morphological, cytometric, cytochemical and cytogenetic studies, as well as cell culture of blood cells in soft agar and in fluid medium.


Bacterial contamination of cotton as an indicator of respiratory effects among card room workers.

The influence of the bacterial contamination of cotton dust on the development of pulmonary symptoms has been investigated. The pulmonary function of card room workers in 23 US cotton mills was tested before and after the Monday working shift. A significant relation was found between the delta FEV1.0 decrement and the vertical elutriator dust level in the different mills. An improved correlation was obtained when the number of Gram-negative bacteria cultured from the bale cotton used in the different mills was employed in the exposure description. The results support earlier epidemiological and experimental studies, which demonstrate the importance of the Gram-negative bacteria in the development of pulmonary symptoms among workers in cotton mills.


Questions of supply and demand in dynamic psychotherapy.

Out-patient psychotherapy resources are severely limited in the face of a considerable mental health problem in the community. A review is made of the literature pertinent to the attempt to estimate the number of patients who receive, or might benefit from receiving, dynamic psychotherapy in the National Health Service. Among the many variables involved, problems of definition and the interests and opinions of general practitioners and hospital psychiatrists are prominent. Implications for the planning of psychotherapy training and service programmes are discussed.


Acute polyhydramnios--a complication of monozygous twin pregnancy.

Eight patients with acute polyhydramnios were encountered in 31 103 pregnancies, an incidence of 1 in 3888. All patients with acute polyhydramnios had monozygous twin pregnancies and 14 of the 16 infants were normal. The condition occurred in the second trimester and usually ended in premature delivery within a few days. The perinatal mortality was 100 per cent and accounted for 14.9 per cent of the perinatal mortality in twins.


An unusual organism causing orbital cellulitis.

Bacterial orbital cellulitis is a feared complication of paranasal sinus infection. Staphylococcus and Streptococcus species are the commoner pathogens involved in these cases. However, anaerobic bacteria and unusual Gram-negative organisms should be suspected as well. We treated a case of bacterial orbital cellulitis due to foci of infected paranasal sinuses caused by Eikenella corrodens, a Gram-negative rod. The patient was managed with intensive antibiotic coverage and surgical intervention.


Double-blind clinical trial of topical steroids in anterior uveitis.

We present the results of a double-blind trial comparing the efficacy of betamethasone phosphate 0.1%, clobetasone butyrate 0.1%, and placebo in the treatment of acute unilateral nongranulomatous uveitis. The 2 steroids were equally comparable in improvement of the patients' symptoms, though betamethasone phosphate was significantly more effective than clobetasone butyrate in improving the ocular signs of uveitis. However, clobetasone butyrate had significantly less effect on raising intraocular pressure in known steroid responders and ocular hypertensives than did dexamethasone. The use of a bolometer as an objective measure in uveitis was significant only in the more severe cases of uveitis. In comparing the placebo group of patients with those on topical steroids, the former group, though improving, appeared to lag behind by approximately one week. Four cases on placebo, however, had to be withdrawn because of worsening of the condition. Mild cases of anterior uveitis would probably resolve without using topical steroids.


Keratoconus, keratoplasty thickness, and endothelial morphology.

A group of successful keratonic grafts (51 eyes) up to 10 years from operation were examined to establish a relationship between graft thickness and acuity. Best acuity occurred in the grafts of normal corneal thickness. No grafts were thinner than normal; thus no tendency to keratonic thinning occurred. No relationship between age of graft and thickness was determined. Endothelial cell studies in vivo of a small number of grafts showed that cell counts a third of normal coexisted with normal acuity and corneal thickness.


Changes in surface charge density on liposomes induced by Escherichia coli endotoxin.

Changes in surface charge density of liposomes induced by E. coli endotoxin were studied by microelectrophoresis. Endotoxin altered the surface charge of phosphatidylcholine liposomes from neutral to negative. The negative charge of the endotoxin-phosphatidylcholine complex was neutralized electrostatically by binding with Ca2+ (2 mM). Phosphatidylcholine liposomes were made positive by addition of the positively charged detergent, hexadecyltrimethylammonium chloride. Endotoxin made the positively charged liposomes less charged. On the other hand, phosphatidylserine liposomes which were negatively charged became less charged in the presence of high concentration of endotoxin (8 mg/ml). The endotoxin effect on phosphatidylserine liposomes was abolished by EDTA (1 mM) but potentiated by CaCl2 (0.1--2 mM). These results indicate that endotoxin interacts with liposomes both hydrophobically and electrostatically.


A method for the synthesis of oligonucleotide by single addition of 2'-O-(o-nitrobenzyl)nucleoside 5'-diphosphates using polynucleotide phosphorylase.

Two hexanucleotides A-U-G-U-G-A and C-A-A-U-U-G were synthesized from the chemically synthesized trimers C-A-A and A-U-G by addition of 2'-O-(o-nitrobenzyl)nucleoside diphosphates using polynucleotide phosphorylase isolated from either Escherichia coli or Micrococcus luteus. In each reaction the preference of the enzyme was tested. The o-nitrobenzyl group was removed after addition of the mononucleotide and the deblocked product was isolated by chromatography on DEAE-Sephadex in high yields.


Steady-state kinetics and the inactivation by 2,3-butanedione of the energy-independent transhydrogenase of Escherichia coli cell membranes.

Kinetic measurements indicate that the energy-independent transhydrogenation of 3-acetylpyridine-NAD+ by NADPH in membranes of Escherichia coli follows a rapid equilibrium random bireactant mechanism. Each substrate, although reacting preferentially with its own binding site, is able to interact with the binding site of the other substrate to cause inhibition of enzyme activity. 5'-AMP (and ADP) and 2'-AMP interact with the NAD+- and NADP+-binding sites, respectively. Phenylglyoxal and 2,3-butanedione in borate buffer inhibit transhydrogenase activity presumably by reacting with arginyl residues. Protection against inhibition by 2,3-butanedione is afforded by NADP+, NAD+, and high concentrations of NADPH and NADH. Low concentrations of NADPH and NADH increase the rate of inhibition by 2,3-butanedione. Similar effects are observed for the inactivation of the transhydrogenase by tryptic digestion in the presence of these coenzymes. It is concluded that there are at least two conformations of the active site of the transhydrogenase which differ in the extent to which arginyl residues are accessible to exogenous agents such as trypsin and 2,3-butanedione. One conformation is induced by low concentrations of NADH and NADPH. Under these conditions the coenzymes could be reacting at the active site or at an allosteric site. The stimulation of transhydrogenase activity by low concentrations of the NADH is consistent with the latter possibility.


The functional identity of the active centres of transketolase.

Direct determination of the number of catalytically active molecules of the coenzyme in holotransketolase (sedoheptulose-7-phosphate:D-glyceraldehyde-3-phosphate glycoaldehydetransferase, EC 2.2.1.1) has corroborated our previous data indicating that in the native enzyme there are two active centres. They have been provided to be functionally identical. It has been shown that the decrease in the specific activity of transketolase during its storage is due to inactivation of one of the active centres, having a lower affinity for the coenzyme. The second active centre retains thereby its full catalytic activity.


Characterization of sterol-ester synthetase in Saccharomyces cerevisiae.

Cell-free extracts of Saccharomyces cerevisiae grown under aerobic as well as semi-anaerobic conditions were found to catalyze the synthesis of fatty acid ester of sterol from cholesterol, fatty acid, ATP and CoA, or from cholesterol and fatty acyl-CoA. This result indicates that the enzyme involved in the formation of the ester is acyl-CoA:sterol O-acyltransferase (EC 2.3.1.26). The enzyme had a broad substrate specificity for sterols and acyl-CoAs. The enzyme levels in the cells grown under aerobic and semi-anaerobic conditions were almost equal. The enzyme was located in the microsomal fraction of the aerobically grown cells.


Prostaglandin thromboxane, and 12-hydroxy-5,8,10,14-eicosatetraenoic acid production by ionophore-stimulated rat serosal mast cells.

Production of several metabolites of arachidonic acid by purified rat serosal mast cells in response to stimulation with the ionophore A23187 was assessed by stable isotope dilution assay using gas chromatography-mass spectrometry. Compounds quantified were prostaglandins D2, E2, F2 alpha, 6-keto-F1 alpha, thromboxane B2, and 12-hydroxy-5,8,10,14-eicosatetraenoic acid. Mast cells incubated at 37 degrees C for 30 min without ionophore produced measurable quantities of all metabolites assayed. 4 microM A23187 resulted in substantial increased synthesis of all metabolites compared to control cells. Of the metabolites quantified, prostaglandin D2 and prostacyclin were the major products derived from arachidonic acid in ionophore-stimulated rat mast cells.


Triaglycerol metabolism in Saccharomyces cerevisiae. Relation to phospholipid synthesis.

The acylglycerol content of Saccharomyces cerevisiae has been examined during cellular growth. The cells maintained a constant amount of phospholipid and diacylglycerol throughout growth. Triacylglycerol content fell in the early exponential phase of growth and then increased sharply upon entry of the culture into the stationary growth phase. Pulse-chase experiments with [1-14C]oleic acid and [2-3H]- and [1-14C]glycerol indicated that the triacylglycerol molecule was utilized for phospholipid synthesis in early exponential phase probably through a diacylglycerol intermediate. A substantial turnover of phospholipid during growth was also apparent. No role for the triacylglycerol could be found in regulating the fatty acid species of the phospholipid nor in the storage of fatty acid for energy metabolism.


Factors affecting the electrophoretic mobility of the major outer membrane proteins of Escherichia coli in polyacrylamide gels.

The outer membrane proteins of Escherichia coli can be resolved by polyacrylamide gel electrophoresis in the presence of anionic detergents. Factors such as the choice of detergent and buffer system and the presence of urea in the separation gel are all shown to affect the charge and/or the configuration of the detergent-protein complexes and will affect the relative migration of these complexes to different extents. The procedures described in this paper may be of use in the determination of the relatedness of the proteins from the same or different strains. In addition, detailed examinations of the effects of these different parameters and the effect of changes in acrylamide concentrations may be useful in the detection of unusual characteristics which may indicate the presence of posttranslational modification.


9-Aminoacridine- and tetraethylammonium-induced reduction of the potassium permeability in pancreatic B-cells. Effects on insulin release and electrical properties.

The effects of 9-aminoacridine and tetraethylammonium on insulin release and rubidium efflux from perifused rat islets were investigated and correlated with their effects on the electrical properties of mouse B cells studied with microelectrode techniques. 9-Aminoacridine (0.05--1 mmol/l) and tetraethylammonium (2--40 mmol/l) produced a dose-dependent, reversible potentiation of glucose-stimulated insulin release. This effect was rapid, affected both phases of secretion and was maximum in the presence of 6 mmol/l glucose, but no longer significant at 20 mmol/l glucose. It was unaltered by atropine or propanolol, and abolished by mannoheptulose or omission of extracellular calcium. 9-Aminoacridine, but not tetraethylammonium, also induced insulin release in the absence of glucose stimulation. Neither drug modified glucose metabolism in islet cells and only 9-aminoacridine increased 45Ca2+ uptake. In the presence of 0, 3 or 6 mmol/l glucose, but no longer at 20 mmol/l glucose, 9-aminoacridine and tetraethylammonium reduced the rate of 86Rb+ efflux from the islets. Both drugs also slightly reduced 86Rb+ uptake by islet cells. In the presence of 11 mmol/l glucose, 9-aminoacridine reduced the amplitude and the duration of the polarization phases between the bursts of electrical activity; concomitantly these periods of spike activity were markedly prolonged. At lower glucose concentrations (3 or 7 mmol/l), 9-aminoacridine progressively depolarized B cells and induced electrical activity in otherwise silent cells. Tetraethylammonium also suppressed the repolarization phases between the bursts of spikes in the presence of a stimulating concentration of glucose. At low glucose, tetraethylammonium produced only a limited and not maintained depolarization. These results show that a reduction of the potassium permeability in pancreatic B cells potentiates the insulin-releasing effect of glucose and may even stimulate secretion. They also suggest that the initial depolarizing effect of glucose is due to a reduction of the potassium permeability, whereas the repolarization at the end of each burst of electrical activity is mediated, at least in part, by an increase in the potassium permeability of B cells.


Studies on the role of beta-cell metabolism in the insulinotropic effect of alpha-ketoisocaproic acid.

alpha-Ketoisocaproic acid has been shown to be a potent insulin secretagogue but the mechanism has not been elucidated. To define the role of beta-cell metabolism in the insulinotropic activity of alpha-ketoisocaproic acid the utilization of glucose and the oxidation of alpha-ketoisocaproic and isovaleric acid by incubated islets of obese hyperglycemic mice were measured. Glucose metabolism was never enhanced by alpha-ketoisocaproic acid. The same 14CO2 amounts were released from the non-secretagogue [1-14C]isovaleric acid (10 mM) or from alpha-keto[2-14C]isocaproic acid (5--20 mM). Pyruvate (20 mM) did not inhibit alpha-ketoisocaproic acid-induced insulin secretion in spite of reduction of decarboxylation of alpha-ketoisocaproic acid by more than 40%. The results indicate that stimulated insulin release in response to alpha-ketoisocaproic acid is not mediated by an indirect increase in glucose metabolism and further suggest that isovaleryl-CoA and following CoA-esters in alpha-ketoisocaproic acid degradation are not likely recognized as signals. The possibility, however, remains that enhanced intramitochondrial production of reducing equivalents elicits insulin secretion.


[Kinetics of the aspartate-aminotransferase reaction catalyzed by free and immobilized cells of E. coli].

The kinetics of the aspartate-aminotransferase reaction were studied, using free and immobilized cells of E. coli, strain 85 as an enzyme source. It was shown that the reaction is limited by mass transport of the reagents through the bacterial cell membrane even at high concentrations of the substrates in the surrounding solution. The polyacrylamide gel-incorporated cells of E. coli, strain 85 catalyze the aspartate-aminotransferase reaction more effectively as compared to free or destroyed cells. In the latter case the reaction is characterized by the following kinetic parameters: the effective values of the stationary rate of the product accumulation and its stationary efflux from the cell are equal to (15,37 +/- 0.4) . 10(-6) mole/s/mg of protein and (3,01 +/- 0,8) . 10(-20) mole/s per 1 cell. respectively. The steady-state constant for glutamate synthesis from aspartic acid is equal to 0,22--0,23.


[Histones from Trypanosoma lewisi nuclei].

A preparation of total histones has been isolated for the first time from the purified fractions of T. lewisi cell nuclei and characterized in terms of its chemical composition and RNA-polymerase activity. A special attention during the isolation procedure was given to the repression of proteolytic degradation of the histones. The amount of protein in the chromatin is equivalent to that of DNA. The amino acid composition and heterogeneity of the protein during polyacrylamide gel electrophoresis in an acid system and in the presence of sodium dodecyl sulfate are typical for histones. Using two-dimensional electrophoresis, differential staining of electrophoregrams and ion-exchange chromatography on CM-cellulose the total preparation has been found to be made up of five fractions: two -- arginine-rich (one of them identical to histone H4, the other being similar to histone H3 from calf thymus); two -- moderately lysine-rich fractions, slightly differing in their properties from histones H2A and H2B from calf thymus, and one specific fraction with mol. weight of 16 000 and an extremely high positive charge. The above methods in combination with specific extraction have been used to demonstrate the absence of a typical lysine histone in the preparation, which is correlated with the absence of typical methaphase chromosomes during mitosis in T. lewisi.


[Synthesis of beta, beta'-subunits of RNA-polymerase in E. coli cells starved for an essential amino acid].

The differential rate of RNA-polymerase beta,beta'-subunits synthesis in E. coli rel+ and rel- cells starved for an essential amino acid, i. e. leucine, is decreased. Inhibition of the rpo BC genes expression proceeds faster in the rel A strain. Guanosine tetraphosphate within the concentration range of 0,2--0,6 mM specifically inhibits lambda drifd18 DNA directed beta,beta'-subunits synthesis in vitro. rpo BC genes are believed to be subject to a weak "stringent control".


[Conformational rearrangements of bacteriophage T4 lysozyme during its binding to the inhibitor].

The structural changes of bacteriophage T4 lysozyme during its binding to the inhibitor, i. e. disaccharide-tetrapeptide N-acetylglucosaminyl-N-acetylmuraminyl - L - alanyl-gamma-D-glutaminyl - mesodiaminopimelyl-D-alanine) isolated from Escherichia coli cell wall have been studied. During the inhibitor binding to the protein the degree of helicity decreases by approximately 14% as was shown using the circular dichroism technique. The changes in optical properties of tryptophane, tyrosine and phenylalanine residues detected by UV difference and fluorescence spectroscopy have been observed. Based on the experimental data and a comparison of spatial organization of phage T4 lysozyme and chicken egg-white lysozyme made it possible to develop a structural model of phage T4 lysozyme functioning. This model may account for the differences in specificity of action of bacteriophage T4 and chicken egg-white lysozymes and allows to establish the role of the "extra" part of phage lysozyme. According to the model, at the first stage of binding the peptide part of the substrate comes in contact with the "upper" (with respect to the cleft) part of the protein molecule (residues 106--116 and 135--140). This results in rearrangement of the molecule, with opening of the cleft at the second stage. This makes possible the access of the polysaccharide part of the substrate of the active site and a subsequent hydrolysis of the beta (1 leads to 4) glycoside bond.


[Isolation of ribosomes with intact rRNA from yeasts].

A simple procedure for isolation of yeast ribosomes with intact rRNA has been developed. Ribosomal rRNA is not degraded after incubation in buffers used for study of protein biosynthesis, for ribosomal disassembly and for their storage.


Terminal deoxynucleotidyl transferase as a hematopoietic cell marker.

Terminal deoxynucleotidyl transferase (TdT) is an intracellular protein characteristic of certain primitive lymphocytes in normal thymus and bone marrow. It can be detected by enzyme assay or immunocytochemical staining. High levels of enzyme and increased numbers of TdT+ cells are found in some lymphoblastic leukemias and lymphomas. Analysis for TdT thus provides a useful adjunct in the differential diagnosis of leukemia.


Leukemia-associated antigens in ALL.

A cytotoxic common ALL antiserum (CALLA) specific for leukemic cells of most patients with non-T-cel- acute lymphoblastic leukemia (ALL) and of some patients with chronic myelogenous leukemia (CML) in blast crisis has been reproducibly prepared using cell lines for absorption. CALLA reacts with leukemic cells of 110 of 134 patients (82%) with non-T-cell ALL; 1 of 71 (1%) patients with acute myelogenous leukemia (AML); 2 of 7 patients (29%) with chronic myelogenous leukemia in blast crisis; 7 of 92 patients (8%) with other hematologic malignancies; and with the leukemic cell lines Laz 221 and NALM-1. It does not react with the normal hematopoietic cells, B- or T-cell lines, or cells from 26 patients with T-cell ALL that were tested. CALLA reactivity and periodic acid Schiff (PAS) staining correlate poorly, with CALLA reacting with cells from 86% (64 of 74) of patients with PAS-positive and 76% (29 of 38) of those with PAS-negative non-T-cell ALL. In these patients, CALLA reacts with cells from 89% of those under age 12 (78 of 88); 74% of those aged 12--20 (20 of 27); and 58% of those over 20 (11 of 19). Using only CALLA and antisera specific for Ia-like and T-cell antigens, we can now distinguish most cases of ALL from AML and other hematologic malignancies.


The use and limitation of labeled staphylococcal protein A for study of antineutrophil antibodies.

Antineutrophil antibodies can be detected following their attachment to neutrophils by employing labeled staphylococcal protein A (SPA). Radiolabeled SPA provides a sensitive means for identifying the presence of IgG restricted to subclasses IgG1, IgG2, and IgG4 that will specifically bind to neutrophils and that are found in the serum of patients with isoimmune and autoimmune neutropenia. However, SPA bound to the Fc region of IgG does not interfere with the attachment of IgG to the Fc domain of the neutrophil. Fluorescein-labeled SPA, in turn is useful in monitoring the functional consequences of antibody attachment to the surface of polymorphonuclear leukocytes (PMN). Both heterologous and isoimmune antisera induced lateral movement of surface antigens into polar-capped pseudopodia. The formation of such pseudopodia may facilitate leukoagglutination and the subsequent removal of sensitized cells from the circulation.


Evidence for the conversion of angiotensin I to angiotensin II by the coronary microcirculation.

Cardiac tissue from hamster neonates was transplanted into the hamster cheek pouch. After vascularization of the transplanted tissue the vessels were tested for their ability to convert angiotensin I (AI) to angiotensin II (AII). AI caused vasoconstriction of the coronary vessels which was reduced significantly by converting enzyme inhibitor and the AII antagonist (Sar1-Ala8) angiotensin II. It was concluded that the vessels of transplanted cardiac allografts convert AI to AII in a manner similar to that observed in the whole heart indicating that this procedure provides a good model for studying the microcirculation of the heart.


Pathophysiology of acute mountain sickness and high altitude pulmonary oedema: an hypothesis.

We review the evidence that acute mountain sickness (AMS) and high altitude pulmonary oedema (HAPO) occur together more often than is realized. We hypothesize that AMS and HAPO have a common pathophysiological basis: both are due to increased pressure and flow in the microcirculation, causing oedema in the brain and oedema in the lungs.


Submarine escape breathing air. A review and analysis of animal and human experiments by the Royal Navy.

The contribution of the Royal Navy to the development of modern submarine escape by free ascent, breathing air, from 1945 to the present time, is described. Much of the work is unpublished. Experiments in which goats were exposed to simulated escape pressure profiles while breathing air from 90 m to 300 m are described. The gradual testing of human subjects during such escape profiles is also reported up to real escapes by subjects from submarines lying at 180 m. Thus escapes are now feasible from almost anywhere on the continental shelf. Possible techniques of even deeper escape, i.e. hyperoxygenated air breathing, oxygen breathing, propulsion + retropulsion of the escaper, drogues + pressure retaining (2 atm abs) escape suits are briefly considered. The figures illustrate the Royal Navy series of animal and human, simulated and real escapes. Table I gives full details on human testing. Tables containing details of all goat exposures can be obtained from author.


Diagnostic and prognostic value of intracardiac electrophysiological studies. Ten years of experience.

Ten years ago a clinical method of recording the electrical activity of the His bundle in man with transvenously inserted electrodes was described. His bundle recording has permitted the breakdown of the P-R interval into three conduction intervals, i.e., intraatrial (P-A), A-V nodal (A-H), and His-Purkinje system (H-V). His bundle studies have demonstrated our inability to accurately predict from the surface electrocardiogram the exact location of most A-V blocks. First- and second-degree A-V block can occur in the atrium, A-V node or His-Purkinje system, and third-degree A-V block in the A-V node or His-Purkinje system. However, Mobitz type II block almost always occurs below the A-V node. Intraventricular conduction defects, especially of the so-called bifascicular block, have a high incidence of H-V time prolongation, indicating additional disease of the third fascicle or the main His bundle. The prognostic value of a prolonged H-V time in patients with and without chronic conduction defects remains controversial, with some agreement that patients with unexplained syncope or dizziness, normal sinus rhythm and 1:1 conduction, who show prolonged H-V times, should probably be paced permanently. No long-term studies exist regarding the value of the H-V time in predicting death or A-V block in patients with conduction defects secondary to acute myocardial infarction, congenital heart disease or after cardiac surgery. Electrophysiological studies have been extremely useful in the diagnosis and management of patients with accessory pathways and in the evaluation of ventricular and supraventricular arrhythmias. The most valuable test in diagnosing sinus node dysfunction is the sinus node recovery time. A clearly abnormal test in a patient with unexplained syncope or dizziness predicts an almost one hundred per cent relief of symptoms with permanent pacing.


A clinical trial of a new low osmolality contrast medium. Sodium and meglumine ioxaglate (Hexabrix) compared with meglumine iothalamate (Conray) for carotid arteriography.

The discomfort of cerebral arteriography is due mainly to the osmolality of the contrast medium injection. A new low osmolality contrast medium--Hexabrix (32% iodine)--sodium and meglumine salts of ioxaglic acid was compared with Conray 280 (28% iodine)--meglumine iothalamate for carotid arteriography in 33 conscious patients. 30 patients preferred the ioxaglate solution which caused significantly less sensation of heat. Three patients could not distinguish between the two media. No patient preferred iothalamate. Ioxaglic acid is a newly synthesized mono-acid dimer. Its salts produce the same osmolality as non-ionics (e.g. metrizamide), and one third of the osmolality of currently used mono-valent salts (e.g. meglumine iothalamate) in solutions of the same iodine content. Low osmolality contrast media have significant clinical advantages and will probably become the media of choice for arteriography and venography.


Morphometry of the human lung: the state of the art after two decades.

This paper reviews the development of the methods for estimating morphometric parameters describing the human lung. The original work was done by light microscopy, but physiologically relevant data depend on studying the delicate structure of alveoli and capillaries by electron microscopy. Methodological improvements of recent years permitted this approach. This yielded estimates of alveolar surface which are by 80% larger than the original data; the reasons are explained by the gain in resolution. On the basis of these data, and by accounting for additional experimental information on the functional availability of gas exchanging surfaces, estimates of pulmonary diffusing capacity (DL) in the range of 90--190 ml O2 . min-1 . mmHg-1 are obtained, which compare reasonably well with physiological estimates of DL obtained under conditions of work.


Pulmonary hypertension, "plexogenic pulmonary arteriopathy" and the appetite depressant drug aminorex: post or propter?

An epidemic of chronic pulmonary hypertension of vascular origin (CPHVO) has occurred in Austria, the Federal Republic of Germany, and Switzerland. The epidemic started in 1967 and reached its peak in 1968 and 1969. Since 1972, the prevalence of patients with CPHVO among individuals investigated by cardiac catheterization is again as low as in the pre-epidemic years. In Bern the prevalence of CPHVO during the peak of the epidemic was 20 times higher than during the 12-year period preceding the epidemic. The clinical, physical, electrocardiographic, radiologic, haemodynamic and respiratory findings of the patients observed in Bern (n = 102) are summarized. There has been a mortality between 12 and 20% at the time of the epidemic. Most patients observed for the first time during the epidemic have remained severely disabled over the years. A minute fraction seems to have recovered. There is a close geographic as well as temporal relation of the epidemic to the marketing and intake of the appetite depressing drug aminorex fumarate (Menocil). Acute administration of aminorex leads to a transient rise of the pulmonary artery pressure and vascular resistance in a number of animal species. It has not been possible to produce sustained precapillary pulmonary hypertension and chronic cor pulmonale vasculare under the conditions of chronic administration of the drug in the species tested. Morphologic examination of lung biopsy and autopsy material of patients who have died from CPHVO after the intake of aminorex reveals the presence of "plexogenic pulmonary arteriopathy". The vascular lesions are identical with those observed in pulmonary hypertension due to large congenital left-to-right shunts. In balancing the pros and cons, it appears that the arguments in favour of a cause-effect relationship between aminorex and pulmonary hypertension, which are derived from epidemiological evidence, outweigh the results of "negative" animal experiments. A "propter" in the title of this paper, therefore, seems to be more appropriate than a post".


A comparative randomized trial of heparin versus streptokinase in the treatment of acute proximal venous thrombosis: an interim report of a prospective trial.

A controlled, prospective study comparing streptokinase and heparin treatment has been completed in 51 patients presenting with acute proximal venous thrombosis of less than 8 days' clinical duration. Patients were studied by means of pre-treatment, post-treatment, 3- and 12-monthly phlebography and pulmonary perfusion scanning and were followed up at 3-monthly intervals. Of the 26 patients randomized to receive streptokinase, therapy was stopped in 3 because of complications. Phlebography 5 days after starting treatment showed 80--100 per cent lysis in 17 of the 23 patients who completed the course of streptokinase. Two patients later developed partial rethrombosis. One patient developed an asymptomatic pulmonary embolus during treatment. During follow-up (mean 19 months) only 1 of the 17 patients with 80--100 per cent lysis developed postphlebitic symptoms, 3 patients died of unrelated causes and 1 patient was lost to follow-up. In patients randomized to heparin therapy no significant lysis was achieved in any of the 25 patients and only 2 of these patients were found to have asymptomatic legs on follow-up. Two patients in this group died and autopsy confirmed massive pulmonary embolus during treatment. These data suggest that streptokinase is superior to heparin in the treatment of acute proximal venous thrombosis of less than 1 week's clinical duration especially if the thrombus is largely non-occlusive. It must be stressed that in order to avoid the bleeding complications of thrombolytic therapy, streptokinase must not be used within 10 days of major surgery, or even longer after vascular, neurosurgical or eye operations.


Prospective trials of minor surgical procedures and high-fibre diet for haemorrhoids.

Two hundred and sixteen consecutive patients seen for the first time with symptomatic haemorrhoids entered trials of conservative and minor surgical treatment. They were divided into two groups according to their pretreatment maximal anal pressure. Patients with pressures of 100 cm H2O (73.7 mm Hg) or more (108 patients) were treated by anal dilatation (37), sphincterotomy (34), or high-fibre diet (37). Four and 12 months later anal dilatation had produced significantly better results than sphincterotomy or diet. Furthermore, anal dilatation was the only treatment associated with a significant reduction in anal pressure at four and 12 months. Patients with pressures under 100 cm H2O (108 patients) were treated by rubber-band ligation (35), cryosurgery (36), or diet (37). Four and 12 months later significantly more patients were improved by rubber-band ligation than by cryosurgery or diet. These results suggest that haemorrhoids in patients with excessive activity of the internal anal sphincter are best treated by anal dilatation and that in all other patients rubber-band ligation is the treatment of choice.


Cultivation of Treponema pallidum in subcutaneous chambers implanted in golden hamsters.

Treponema pallidum was successfully grown in subcutaneous chambers in golden hamsters. Abnormally long forms of T. pallidum were found in these chambers. The cause of this abnormality may possibly be due to their being coated with antibody which could inhibit cell division or render the organism avirulent or both. T. pallidum was successfully passaged between hamsters but with a possible diminution in virulence.


Double-blind trial of amoxycillin and ampicillin plus probenecid in the treatment of gonorrhoea in men.

In a double-blind study amoxycillin 3 g or ampicillin 3 g plus probenecid 1 g were randomly administered as a single oral dose to 160 men with uncomplicated gonococcal urethritis. The cure rate for each drug group was 98.6%. Tolerance to oral medication was good and no evidence of allergy or toxicity to either drug was shown. No case of post-gonococcal urethritis was observed over a 14-day follow-up period. Thus, both drug regimens proved very effective in treating uncomplicated gonococcal urethritis in men.


Double-blind comparison of a single dose and a five-day course of metronidazole in the treatment of trichomoniasis.

Although there have been reports of the results of treating trichomoniasis with metronidazole 2 g in a single dose, no randomised double-blind comparison of this treatment with a multiple-dose regimen has been reported. In such a comparison, 96 women were treated with metronidazole 2 g in a single dose and 96 women with metronidazole 400 mg twice daily for five days. Forty-eight of 52 women followed for 14 days after the single dose were cured, as were 61 of 66 women followed for 14 days after the start of the five-day regimen. These results compare favourably with previous reports. Side effects were trivial, and we recommend the single 2-g dose, for it is effective, economical, and can be given under supervision in the clinic.


Epidemiological investigation of patients with vulvovaginal candidosis. Application of a resistogram method for strain differentiation of Candida albicans.

The resistogram method was applied to 420 isolates of Candida albicans obtained from 30 selected patients undergoing treatment for vulvovaginitis. Of these, 16 patients each harboured a particular strain of C. albicans which persisted in the mouth or intestinal tract or both. In three of these patients, this strain persisted in the genital tract, and, in eight patients, it later recolonised the genital tract. Fourteen patients harboured more than one strain of C. albicans: one failed to respond to treatment and continued to harbour the same strain in the genital tract; in five the original strain later recolonised the genital tract and a second strain remained confined to the mouth or intestinal tract or both; and in three a second strain, present in the intestinal tract, later colonised the genital tract. Each of the male partners of seven patients harboured a strain of C. albicans that was identical to the strain, or to one of the strains, that had been isolated from his female partner.


Effect of simultaneous oral and vaginal treatment on the rate of cure and relapse in vaginal candidosis.

One hundred patients with vulvovaginal candidosis were entered in a double-blind trial to compare the effect of six days' local treatment with clotrimazole with that of the same treatment plus 10 days' oral treatment with nystatin. No significant differences were detected in the rate of cure or relapse between the treatment groups. The cure rate was lowest and the relapse rate highest in patients in whom vaginal candidosis had last been diagnosed during the preceding 12 months.


A trial of isolating a tumor-like form of pulmonary cavities infected with aspergilli. II. Intra- and postoperative, morphologic and serologic data.

In ten specimens of resected pulmonary tissue, a little known and underscribed form of aspergillosis called tumor-like blocked pulmonary cavity with liquid content infected with aspergilli was observed. This designation was based on the finding in the specimens of tumor-like cavitary structures with blocked bronchus and contents from which abundant growth of aspergillus fumigatus was invariably obtained in cultures. Nine of the ten specimens were bronchiectasis, and one was a bronchogenic cyst. The scant literature was review, emphasizing features characteristic of this form of mycetoma and differences from the typical and frequently encountered form of ordinary pulmonary aspergilloma. The serologic response and its long duration were attributed to biological properties of aspergilli in this form caused by inaccessibility of oxygen and by occlusion of the bronchial lumen.


A proximal system for positive end-expiratory pressure (PEEP) and continuous positive airway pressure (CPAP).

A proximal positive end-expiratory pressure (PEEP) and continuous positive airway pressure (CPAP) system was constructed by the simple addition of a venturi T-piece proximal to the exhalation limb of a breathing circuit. The level of PEEP or CPAP was determined by the amount of flow powering the venturi. This system can provide positive pressure in excess of 40 cm H2O without the need for check valves, dump valves or additional nebuliers and flowmeters.


Contagious equine metritis: a review.

Contagious equine metritis is a highly contagious genital infection of mares, spread venereally, and was first described in 1977. Although most contagious equine metritis outbreaks involved Thoroughbreds, infection in other breeds has also occurred. The disease has been reported in Europe, Australia and the United States. In Canada, contagious equine metritis has been designated a reportable disease under the Animal Disease and Protection Act. Contagious equine metritis is characterized by an endometritis and infertility and infected mares show no signs of systemic infection. Clinical signs have not been observed in stallions. An asymptomatic carrier state exists in both mares and stallions.Infected mares respond clinically to the topical and parenteral administration of antibacterial drugs. However, a proportion of mares remain carriers of the contagious equine metritis organism. Treatment of stallions is successful. Haemophilus equigenitalis has been proposed as the species name of the Gram-negative, microaerophilic coccobacillus. Sample collection and laboratory methods for the diagnosis of contagious equine metritis are described.


Inhibitory effects of a new oral gold compound on HeLa cells.

Auranofin (AF), a recently introduced oral antirheumatic coordinated gold compound, was investigated for its antitumor potential. Due to certain similarities with the antitumor-coordinated compound, cis-Diamminedichloroplatinum II, we studied the effects of AF on cell proliferation. These studies included assessing DNA, RNA, and protein synthesis as measured by incorporation of 3H-thymidine, 3H-uridine, and 3H-leucine, respectively, into HeLa cells. AF was shown to exert a dose-dependent inhibition on DNA synthesis and to inhibit 3H-thymidine uptake more rapidly and persistently than 3H-uridine or 3H-leucine uptake at a gold concentration of 75--100 micrograms/dl. These three parameters were inhibited with a 24-hour exposure to 100 micrograms/dl. The inhibition of 3H-thymidine uptake in HeLa pretreated for 6 hours with 50 or 100 micrograms/dl of gold was found to be irreversible. No change in tracer uptake was observed in the acid-soluble pool or in the uptake of 3H-2-deoxy-D-glucose in these cells. Furthermore, HeLa cells demonstrated marked reductions in viability and oxygen uptake after exposure to AF. Dose-dependent surface morphological changes, e.g., blebbing, pitting, were noted in these cells after a brief treatment period. These results suggest this coordinated gold compount exerts a significant inhibitory effect on essential biological processes and functions.


Refractory anemia with excess of blast cells: prognostic factors and effect of treatment with androgens or cytosine arabinoside. Results of a prospective trial in 58 patients. Cooperative Group for the Study of Aplastic and Refractory Anemias.

The results of a prospective study of 58 patients with refractory anemia and partial blastic infiltration of the bone marrow lead to the following conclusions. The median survival (12 months from diagnosis) is shorter and the rate of acute leukemia as cause of death (60%) higher than in other retrospective series. This group of patients, however, appears to be a "continuum" of preleukemic states with more or less rapid evolution, so that the exclusion of the most severe cases appears unjustified. Based on the degree of bone marrow blastosis, and also on the degree of blood cytopenias, the anomalies of 59 Fe incorporation kinetics and the bone marrow stem-cell cultures, it is possible to derive a plausible prognosis for individual patients, which could aid the choice of therapy. Androgen therapy does not accelerate leukemic evolution, but does not improve the bone marrow insufficiency. Cytosine-arabinoside at low dosage exhibited no toxicity, but did not delay the appearance of overt leukemia.


Non-Hodgkin's lymphoma in children: a progress report on the original patients treated with the LSA2-L2 protocol.

This report is a follow-up of the initial group of 39 children with non-Hodgkin's lymphoma treated with the LSA2-L2 protocol as previously reported in Cancer (37:123--134, 1976). The disease-free actuarial survival is 73%. All surviving patients are off therapy and have shown no evidence of recurrence with a median observation time of 70+ months. Their survival times range from 56+ to 88+ months from diagnosis. An analysis of successes and failures is discussed and modifications in the role of radiation therapy and surgery in the multidisciplinary management of children with non-Hodgkin's lymphoma are advocated. The results in the present series indicate that the LSA2-L2 protocol has substantially improved the prognosis for children with non-Hodgkin's lymphoma. We have concluded that age, sex, primary site (perhaps with the exception of primary skeletal), and histology are not of prognostic significance. The amount of bulky widespread disease at initial presentation, early and aggressive therapy, and the achievement of a complete remission status within 1--2 months from onset of therapy are the most important prognostic factors.


Adriamycin, BCNU, ftorafur chemotherapy of pancreatic and biliary tract cancer.

Twenty-six evaluable patients with disseminated or locally unresectable pancreatic or biliary tract carcinoma received Ftorafur (4 g/m2 iv day 1 and 22 and 2 g/m2 iv day 4 and 26), Adriamycin (60 mg/m1 IV day 1 and 45 mg/m2 iv day 22) and BCNU (150 MG/M2 IV DAY 1) combination chemotherapy (FAB) repeated at 6--8 week intervals. Two (29%) complete and one (14%) partial remissions were observed in 7 patients with biliary carcinoma while 5 of 19 (26%) patients with pancreatic carcinoma achieved partial remissions. Median survival for responding patients was approximately 11 months (range 7--16+) with median survivals of about 6 months (p less than 0.05 and about 3 months (p less than 0.05) for patients with stable and progressive disease. Major drug toxicity was myelosuppression with median lowest granulocyte counts of 1,000/microliters and platelet counts of 88,000/microliters. Approximately 25% of patients required antibiotic therapy for fever of unknown origin or documented infections. Other tolerable drug toxicities included nausea, vomiting and mucositis. The FAB regimen appears quite promising in biliary tract cancer and has efficacy in pancreatic carcinoma that warrants further clinical trials. Because of myelotoxicity observed with this regimen we now recommend a BCNU starting dose of 100 mg/m2 instead of 150 mg/m2.


Post-therapeutic acute leukemia.

This study reports 35 cases of posttherapeutic acute leukemia and reviews the literature on this subject. These AL's are characterized by a high incidence of anemia, in particular refractory anemia, preceding the hematological disorder by several months, by the frequent finding of myelofibrosis, by the essentially granulocytic nature of the AL, and by the low rate of remission and the, in general, extremely short sruvival of a few months. These leukemias may develop following continuous chemotherapy with an alkylating agent, radiotherapy of various extent, or most commonly following intensive treatment with extensive irradiation and polychemotherapy as in the management of Hodgkin's disease. In view of these therapeutic hazards, the present objectives are the modification of alkylating agent therapy by the use of other drugs and sequential administration, and a reduction in the dose and field of irradiation and the duration of polychemotherapy, as in Hodgkin's disease; all present protocols are orientated in this direction.


Fatal hypoglycemia after cytotoxic chemotherapy: a report of two cases and a review of the literature.

Two cases, one of leukemia and one of a trophoblastic testicular teratoma, are described in which hypoglycemia occurred as a terminal event. The rarity of this association with these types of malignancy, together with possible mechanism, is discussed in a brief review of the literature.


Angiosarcoma following therapeutic irradiation.

This paper reports a case of angiosarcoma of the terminal ileum in a 66-year-old female. This angiosarcoma developed 8 years after postoperative irradiation for ovarian carcinoma. This case appears to be the sixth case of angiosarcoma arising at the site of therapeutic irradiation thus far reported in the literature. The fact that the angiosarcomas in these cases developed in anatomic sites, which are unusual for angiosarcomas in general, suggests that there is a cause-and-effect relationship between irradiation and angiosarcoma. Apart from the direct carcinogenic effect of irradiation, prolonged stimulation for tissue repair resulting from tissue damage secondary to irradiation-induced vascular changes may also play an etiologic role in the development of angiosarcomas in these cases.


Thorotrast-associated sarcoma of bone: A case report and review of the literature.

An osteosarcoma developed near the right lesser trochanter of a 55-year-old woman. The neoplasm fulfilled the generally accepted criteria for a Thorotrast related malignancy. Strengthening this relationship was the occurrence of the tumor in an unusual location and uncommon age group. Thorium was confirmed both in the tumor and in bone marrow histiocytes by its characteristic x-ray spectrum. Including this case only twelve Thorotrast-associated neoplasms of bone have been reported. The mean latency period after Thorotrast administration was 26 years. Regression analysis revealed that latency period and Thorotrast dose are inversely related. All tumors were reported to be sarcomas. Six osteosarcomas, one fibrosarcoma, one chondrosarcoma, and one undifferentiated sarcoma were proven histologically. All patients, for whom follow-up was given, had died of the tumor. The reasons behind the low frequency of reported Thorotrast-associated bone malignancies may be the low concentration of 232Th and radioactive daughters in bone, long latency period or the general lack of knowledge concerning the possible relationship between Thorotrast and bone tumors. Statistical association between Thorotrast injection and bone sarcoma is shown. The criteria for the diagnosis of Thorotrastosis are discussed as well as the long term deleterious effects. The distribution of Thorotrast within the body is discussed as well as the associated radiographic changes.


Immunohistochemical study of the medullary thyroid carcinoma with reference to C-thyroglobulin reaction of tumor cells.

Twelve cases of medullary thyroid carcinoma were investigated ty the immunoperoxidase method using anti-calcitonin, anti-C-thyroglobulin (C-Tg, C cell-immunoreactive thyroglobulin) and anti-19S thyroglobulin antisera. Tumor cells as well as normal C cells revealed distinct immunoreaction for C-Tg besides for calcitonin. In contrast to normal C cells, the tumor cells were stained more intensely by anti-Ctg antiserum than by anti-calcitonin antiserum. Furthermore, there occurred several tumors or some areas of tumors which showed strong response to anti-C-Tg antiserum but weak or no response to anti-calcitonin antiserum. Thus, medullary carcinoma cells synthesized far greater amounts of C-Tg than calcitonin. The small follicles were occasionally observed mingled in typical cell solid masses. They stored colloid-like materials which were intensely immunoreactive to C-Tg but nonreactive to calcitonin. The specific immunoreaction patterns to anti-C-Tg and anti-calcitonin antisera were also obtained on the ground materials of the amyloid. On the histogenesis of amyloids of medullary carcinoma, the C-Tg could be the presursor of the fibrillar protein of amyloids and the component of the fibrillar protein also closely related to calcitonin.


C-cell disease of the thyroid gland in multiple endocrine neoplasia, type 2b.

Multiple endocrine neoplasia, type 2b (MEN 2b) is a disorder characterized by C-cell disease of the thyroid gland (medullary carcinoma or C-cell hyperplasia, or both), pheochromocytoma, ganglioneuromatosis, and skeletal and connective tissue abnormalities. The medullary thyroid carcinoma (MTC) is bilateral and multicentric; it metastasizes locally and distally, often before the disease is recognized. Histologically proven C-cell disease was present in 89 of the 107 patients (83%) reported with the condition, including 17 Mayo Clinic patients (average age at diagnosis, 19.2 years). Nineteen of the 107 patients (18%) died of MTC (average age at death, 25.3 years); 9 (8%) succumbed to pheochromocytoma, 7 of these also having metastatic MTC; 13 12%) died of other or unknown causes, but 2 of these had disseminated MTC as well; 29 (27%) survive with metastatic MTC; an additional 21 (20%) are alive, but concentrations of plasma immunoreactive calcitonin (iCT) have not been measured; 6 more (6%), 5 of whom had thyroidectomy before the age of 12 years, are alive with normal plasma concentrations of iCT; and the remaining 10 (9%) have been lost to follow-up. Survival of patients with MEN 2b after operation was reduced when compared with that of a control population -- 80% versus 99% at 5 years and 50% versus 98% at 10 years. The only effective treatment for MTC is total thyroidectomy before metastasis occurs. "Cure" of MTC in patients with MEN 2b has generally been obtained in those having total thyroidectomy before age 12. Therefore, in young patients suspected of having MEN 2b, we recommend prompt evaluation of C-cell function by measurement of stimulated concentrations of iCT and treatment by total thyroidectomy if results are abnormal.


Follicular (nodular) lymphoma in childhood: a rare clinical-pathological entity. Report of eight cases from four cancer centers.

Eight cases of follicular lymphoma (FL) were found amount 318 children with non-Hodgkin's lymphoma seen in two decades in four large institutions (overall incidence: 2.5%). The children's ages ranged from 3 to 13 years (median 8). Four patients presented with localized peripheral lymphadenopathy, two with tumors of the digestive tract, two with disseminated disease. Five were tentatively classified as stage I or II and 3 as stage IV. The existence of other diseases responsible for lymphadenopathy could satisfactorily be exclued. All patients are alive after follow-up periods of 1 to 14 years from diagnosis (median 4). Morphologically, 5 lymphomas were mixed and 3 histiocytic. The growth pattern was "expansile" in the younger patients (3 to 9 years), and "infiltrative," as in the adult disease, in the three older children (11 to 13 years). The histiocytic cytology correlated with stage IV disease. FL in children appears to be different from both its adult counterpart and the diffuse childhood lymphomas. Differences with the former include the absence of tumors of poorly differentiated lymphocytic type, the higher frequency of stage I-II disease and the better prognosis. This last feature, as well as the higher frequency of peripheral node involvement and the absence of leukemic conversion or CNS disease, differentiates the follicular from the diffuse childhood lymphomas.


Hypercalcemia complicating childhood malignancies: a report of seven cases with some pathophysiological considerations.

A group of seven children with different malignant processes presenting with hypercalcemia was studied. Bone destruction, diffuse metabolic abnormalities, abnormal acid-base homeostasis and recurrent hypercalcemia characterized these patients. A different mechanism leading to the production of hypercalcemia and/or bone destruction by cancer cells is considered. The results of this report suggest that parathyroid hormone production (P.T.H.) by the parathyroid glands is normal and that ectopic secretion of PTH or PTH-like material is negligible in these cases.


Acute myeloblastic leukemia developing in patients with mediastinal lymphoblastic lymphoma.

Of three patients with mediastinal malignant lymphoma, lymphoblastic type, at the time of diagnosis one also had acute myeloblastic leukemia (AML), and the other two had blood and bone marrow findings indicative of acute lymphoblastic leukemia (ALL). The latter two patients developed the hematologic picture of AML less than eight months later. In all cases, AML was confirmed by cytochemical studies of peripheral blood and bone marrow cells. Autopsy of two of the patients revealed only AML. The myeloid nature of the proliferative cells was demonstrated with the naphthol-ASD-chloroacetate stain (NCA) on postmortem tissue sections. This study further supports the hypothesis of a common origin of neoplastic lymphoid and myeloid cells from pluripotent bone marrow stem cells.


The reduced mutagenicity of aflatoxin B1 due to hydroxylation: observations on five Salmonella typhimurium tester strains.

The mutagenicity of aflatoxin M1 relative to that of aflatoxin B1, the parent compound, was studied in 5 Ames' tester strains of Salmonella typhimurium (TA 98, TA 100, TA 1535, TA 1537, TA 1538). Aflatoxins B1 and M1 are both highly mutagenic in microsome-mediated system in TA 100. The prediction of the relative carcinogenicity of aflatoxin M1 to aflatoxin B1 posed by the mutation of TA 100 is probably more authentic than by TA 98.


Formation of mutagens in cooked foods. I. Beef.

Mutagens detectable by Salmonella typhimurium TA98, after activation by liver S-9 fraction, are formed when meat is cooked by frying, broiling and boiling. High levels of mutagenic activity are formed rapidly when frying, or more slowly during broiling. Formation of mutagens in boiled beef stock requires several days under reflux, but shows a strong concentration dependence. Time curves suggest that a period exists during which mutagens are not readily formed; however, after this period mutagen production is rapid. Hamburgers from commercial franchises were frequently mutagenically active.


Mutagenic activity of gastric juice.

Gastric juice samples from patients of a rural area of the Colombian Andes at high risk to gastric cancer were tested for mutagenesis with Salmonella typhimurium strains TA100 and TA1538. Direct mutagenic effect was found in samples with detectable amounts of nitrite. This effect was not accountable by nitrite alone. Nitrite-negative samples from the same area and samples from the low-risk area of Cali were negative using the same mutagenesis assay.


Fractionation of a mutagenic principle from broiled fish by high-pressure liquid chromatography.

A mutagenic principle present in the basic fraction of broiled sardines cooked in the ordinary way was fractionated by high-pressure liquid chromatography using a reversed-phase column. Results indicated that the major mutagenic principle is not identical with any of the mutagens previously isolated from amino acid pyrolysis products, and that a new, unidentified mutagen exists in broiled sardines.


Mutagenicity of metabolites of carcinogenic aminoazo dyes.

The mutagenicity of 8 azo dyes and 6 p-phenylenediamine derivatives, which comprised the metabolites of carcinogenic 4-aminoazobenzene derivatives, was studied on Salmonella typhimurium TA98 and TA100. 4'-Hydroxy-N-methyl-4-aminoazobenzene and its O-sulfate and O-glucuronide, and 3-hydroxy-4-aminoazobenzene were mutagenic on TA98 in the presence of S-9 mix. p-Phenylenediamine and its o-methoxyl derivative were definitely mutagenic on TA98 with the addition of S-9 mix. All metabolites tested were non-mutagenic on TA100, although the mother azo dyes were mutagenic both on TA98 and TA100 in the presence of S-9 mix. These results rule out a possibility that the mutagenicity, at least on TA100 microbes, of carcinogenic 4-aminoazobenzene derivatives may be mediated by any of the ring-hydroxyl or azo reduction metabolites and their conjugates produced from the azo dyes by incubation with S-9 mix.


Effects of glucose-insulin-potassium infusion on the angina response during treadmill exercise.

The effects of glucose-insulin-potassium (GIK) and placebo normal saline (S) infusion on treadmill-walking time to angina, ST depression, heart rate (HR), systolic blood pressure (SBP), rate pressure product (RPP), blood glucose (G), lactate (L) and free fatty acids (FFA) were studied in 14 non diabetic patients with exertional angina. For the whole group, the post-GIK walking time to angina (393 +/- 33 sec, mean +/- SEM) was greater than the values during control GIK (319 +/- 20 sec, p less than 0.02) and post-S infusion (334 +/- sec, p less than 0.05), but circulatory and ST responses were similar in post-GIK and post-S studies. 7 of the 14 patients experienced significantly greater improvement in exercise tolerance following GIK (467 +/- 39 sec) in comparison to control GIK (313 +/- 29 sec, p less than 0.001) and post-S infusion (334 +/- 32 sec, p less than 0.005) and exercised to a higher HR, SBP and RPP after GIK than after S infusion. At the onset of angina these patients had similar ST-segment depression before and after GIK but when ST segments were assessed after GIK at the same exercise duration when angina had occurred during the control and post-S studies, there was significantly less ST depression (p less than 0.01). Of the remaining 7 patients exercise tolerance following GIK deteriorated in 3, remained unchanged in 2 and increased by 12 and 48 sec in 2 patients in comparison to post-S values. Comparison of post-GUK and post-S values for G, L and FFA for the whole group showed significantly lower resting values of FFA and post-exercise values of G following GIK infusion. The differences in clinical and circulatory responses between patients who improved and those who did not improve following GIK were not related to the angiographically determined severity of coronary artery disease or to GIK-induced metabolic changes. Results suggest that some patients with angina pectoris do benefit  from GIK infusion but the response in a given patient to this therapeutic modality is unpredictable.


Effects of training and of verapamil on exercise capacity in patients recovering from myocardial infarction. A double-blind study.

Physical training causes an increase of aerobic capacity in normal and cardiac patients. The influences of training plus placebo and training plus verapamil have been studied in a double-blind randomized trial on 40 patients recovering from actue myocardial infarction. The two groups were comparable as to clinical characteristics, initial work capacity, and amount of stress tolerated during the training sessions. The training produced a significant increase of total work capacity and maximum VO2, in both groups; the difference between the means of the two groups was not significant. The variation of heart rate, rate pressure product at different work loads and cardiac volume after training were significantly lower in the verapamil group. The anginal threshold did not change in the placebo group and showed a trend to increase in patients treated with verapamil. These results suggest that carefully observed rehabilitation markedly improves the physical capacity of the patients after acute myocardial infarction. Such improvement is enhanced by treatment with verapamil.


Cellular organization of the lateral and postinfundibular regions of the median eminence in the rat.

The structural organization of the rostral, lateral and postinfundibular regions of the median eminence (ME) of 5-day cyclic diestrous rats was studied with light and electron microscopic methods. The ependymal cells lining (i) the floor of the infundibular recess (IR) at rostral levels, (ii) the lateral extensions of the IR, and (iii) the floor of the premammillary recess appear to represent the same type of tanycyte ependyma (beta 1 tanycytes). In the entire width of the rostral and postinfundibular palisade regions, as well as in the lateral palisade region of the preinfundibular ME, the processes of the beta 1 tanycytes form a continuous cuff. This cuff separates the nerve endings from the blood vessels and the pars tuberalis. At this level, synaptoid contacts between neurosecretory axons and the ependymal cuff can be observed. The ultrastructural characteristics of the beta 1 tanycytes are described and their ependymal endings tentatively classified into three types. In the lateral regions of the ME, the Golgi study revealed the presence of two fiber systems: (i) one possessing a latero-medial trajectory and distributed in the subependymal region; (ii) the other formed by a loose longitudinal tract originating from neurons of the arcuate nucleus. Some functional implications of the cellular organization of the rat ME are discussed.


Simultaneous localization of steroid and peptide hormones in rat pituitary by combined thaw-mount autoradiography and immunohistochemistry: localization of dihydrotestosterone in gonadotropes, thyrotropes and pituicytes.

The immunocharacteristics of androgen target cells in the anterior pituitary of male rats are assessed by a combined thaw-mount autoradiography and immunoperoxidase staining method permitting the simultaneous identification of steroid-hormone target cells and protein or polypeptide hormone-producing cells in the same preparation. After injection of 3H-dihydrotestosterone, nuclear concentration of radioactivity is observed in cells of the anterior lobe, in "ectopic" cells in the intermediate and posterior lobes as well as in certain pituicytes. The radioactively labeled cells in the anterior lobe are identified immuno-histochemically as gonadotropes and thyrotropes with the use of antiserum to ovine LH or its subunit beta-LH and bovine beta-TSH. The results suggest genomic effects of androgen on gonadotropes and thyrotropes as well as pituicytes.


Immunohistochemical localization of a gastrin-like peptide in the brain of an amphibian, Xenopus laevis Daud.

The indirect immunofluorescence technique was used to demonstrate a substance reacting with gastrin antisera in the brain of Xenopus laevis. Immunoreactive material was found in two sites: (1) In the caudal hypothalamus more precisely in the nucleus infundibularis ventralis, (NIV) of the pars ventralis of the tuber cinereum, (PVTC). The fluorescent axons of the reactive parikarya of the NIV give rise to two symmetrical tracts which run rostro-ventrally and join, in the infundibular floor, the preoptico-hypophysial tract, where they form an uneven median tract coursing caudally and running along the medio-tuberal area before entering the external zone of the median eminence. (2) In the anterior preoptic area (APOA), where numerous nerve fibers and endings form a dense network near the preoptic recess. The exact origin of these terminals has not yet been determined. Control of immunohistochemical specificity shows that the labeling by gastrin antisera is suppressed by gastrin (2--17), but also by cholecystokinin (CCK) and pentagastrin (Peptavlon). These results indicate that the immunoreactive substance revealed belongs to the gastrin group and has an antigenic determinant composed of the amino acid sequence or a protion thereof common to gastrin, CCK and Peptavlon (Trp-Met-Asp-Phe). It should be emphasized that, in the brain of Xenopus laevis, both gastrin-immunoreactive sites correspond to the sites of uptake of steroid hormones (Kelley et al., 1975; Morrell et al., 1975).


Pancreatic endocrine cells of Barbus conchonius (Teleostei, Cyprinidae), and their relation to the enteroendocrine cells.

The pancreatic endocrine cells of Barbus conchonius are concentrated in a large (principal) islet, located near the gall bladder, and in a number of smaller islets. Five types of endocrine cells can be distinguished in there pancreatic islets: B cells, A1 (or D cells), 2 types of A2 cells (A2r cells with round granules; and A2fl cells with flocculent granules) and a scarce 5th cell type. The hormones produced by B and A2fl cells are probably insulin and glucagon respectively. The A2r cell contains granules with the same diameter as the granules of the enteroendocrine type III cell of the gut. Both cell types may resemble the enteroglucagon-producing EG cell of mammals. The function of the A1 cells, which are frequently found without secretory granules, and of the 5th cell type, will be discussed. The pancreastic islets of B. conchonius are strongly innervated, which suggests thatpresence of a direct nervous control system. Some intermediate or mixed cells containing exocrine and endocrine A2r granules are found continguous with the principal islet. The origin of pancreatic endocrine cells is also the subject of discussion.


A precursor to a minor species of yeast tRNASer contains an intervening sequence.

Certain tRNAs in S. cerevisiae (tRNATyr and tRNAPhe) arise via precursor molecules which are mature at the 5' and 3' termini but contain intervening sequences adjacent to the anticodon (Knapp et al., 1978; O'Farrell et al., 1978). In addition to these molecules, precursors to several other tRNAs accumulate in a temperature-sensitive mutant (ts136) at the nonpermissive temperature. We have analyzed one of these species and shown that it is a precursor to a minor species of tRNASer. This precursor is also mature at both termini and contains an intervening sequence of 19 nucleotides adjacent to the hypermodified A residue 3' to the anticodon. The sequence can be arranged in a secondary structure in which the anticodon stem is extended by additional base-pairing, and contains the sites of excision and ligation within two looped regions. Support for this structure was provided by analysis of the products of limited digestion with RNAase T1. recently Piper (1978) reported the isolation of a minor species of tRNASer which decodes UCG. He found this species to be structurally heterogeneous and determined that the less abundant form corresponds to the tRNA which is altered in the recessive lethal SUP-RL1 amber suppressor. Our data now suggest that the more abundant form may be restricted to reading UCA in vivo; thus mutation of the minor species would result in complete loss of UCG-decoding ability and explain the recessive lethality of SUP-RL1. We have shown that the precursor which accumulates in ts136 corresponds exclusively to this minor tRNASerUCG species. Our results suggest that this may be the only gene for tRNASer in yeast which contains an intervening sequence.


Splicing of yeast tRNA precursors: a two-stage reaction.

Soluble extracts of S. cerevisiae splice tRNA precursors which contain intervening sequences. The reaction goes to completion and requires ATP for the production of mature sequence tRNA. In the absence of ATP, half-tRNA molecules accumulate. Similar half-tRNA molecules appear as kinetic intermediates and accumulate if splicing is inhibited with pure, mature tRNA. Half-tRNA molecules have been purified. These half-tRNAs are efficiently ligated in an ATP-dependent reaction that is inhibited by added mature tRNA. The product of ligation is the expected mature sequence tRNA. The excised intervening sequence has also been identified. These results suggest an enzymatic mechanism for splicing which involves two independent steps.


Splicing of yeast tRNA precursors: structure of the reaction intermediates.

The intermediates of the yeast tRNA splicing reaction have been characterized. The intervening sequence is excised as an unique linear molecule. It has 5'-hydroxyl and 3'-phosphate termini. Correspondingly, the half-tRNA molecules are shown to have a 3'-phosphate terminus on the 5' half and 5'-hydroxyl terminus on the 3' half. These isolated halves have been shown to be active in the ligation step of tRNA splicing. Removal of the 3'-phosphate from the 5' half eliminates the ability of the 5' half to participate in ligation.


Assembly of the mitochondrial membrane system: sequences of yeast mitochondrial valine and an unusual threonine tRNA gene.

The mitochondrial DNA segments of two independently isolated rho- clones of S. cerevisiae carrying a genetic marker for a threonine tRNA have been characterized by restriction endonuclease analysis and DNA sequencing. The DNA sequences of the two segments have been used to deduce the primary and secondary structures of the tRNA. The threonine tRNA is unusual in having a leucine anticodon (3'-GAU-5'). Despite the anomalous anticodon, the tRNA is proposed to function in mitochondrial protein synthesis. One of the rho- clones contains an additional coding sequence that has been identified as a valine tRNA genes have been located on the wild-type physical map and determined to be transcribed from two different strands.


Role of plasmid-coded RNA and ribonuclease III in plasmid DNA replication.

An in vitro replication system has been used to study the control of DNA replication of the relaxed plasmids Col E1 and RSF1030. An RNA transcript approximately 100 nucleotides long is synthesized during the in vitro DNA replication reaction. This RNA is synthesized approximately 450 bp away from the origin of replication. A small insertion in the coding sequence for the RNA made from Col E1 DNA leads to a larger RNA species and simultaneously to an increase in plasmid copy number. Revertants missing the specific insertion show shorter RNA transcripts and wild-type copy number. Although plasmids Col E1 and RSF1030 have no extensive sequence homology, the RNA synthesized during RSF1030 replication has almost the same mobility as the Col E1 RNA on polyacrylamide gels and hybridizes to the Col E1 origin region. Extracts prepared from mutants of Escherichia coli deficient in ribonuclease III do not replicate RSF1030 or Col E1 plasmids in vitro. When supplemented with homogeneous RNAase III, such extracts do support DNA replication on these templates, indicating that RNAase III is required for DNA replication. We propose that the 100 nucleotide RNA species is involved in regulating the initiation of DNA replication of these plasmids, and that RNAase III may be involved in processing this RNA.


Clinical study of hydrazine sulfate in advanced cancer patients.

Twenty-five patients with a variety of solid tumors were treated with hydrazine sulfate. Hydrazine was given orally in the form of 60 mg capsules from one to four times daily. No patient had a 50% reduction of tumor size. Subjective benefit was seen in three patients but it was of brief duration.


Podophyllotoxin derivative VP 16-213.

VP 16-213, a derivative of podophyllotoxin, is currently entering phase-III studies. Its mode of action is incompletely understood, but differs markedly from that of its parent compound. The greatest lethal damage is experienced by cells in the late S and G2 phases. In the L 1210 system the drug shows marked schedule dependency: prolonged administration may be more effective than single bolus administration. As a single agent, VP 16-213 is the most active compound yet tested against small-cell bronchial carcinoma. It may also prove to be a useful agent in patients with other types of lung tumour, testicular teratomas, and some types of leukaemia. No long-term or cumulative toxicity has been reported. Most side effects are predictable and reproducible.


Potential of liposomes as drug-carriers in cancer chemotherapy: a review.

Liposomes are bilayered phospholipid vesicles that have been proposed as vehicles for the selective delivery of cytotoxic drugs into malignant cells. In vitro and in vivo experiments have indicated that the activity of a range of drugs or their active metabolites may be enhanced by encapsulation in liposomes, particularly when used against drug-resistant tumours. Moreover, liposomal entrapment certainly has a marked effect on the tissue distribution and rates of clearance of cytotoxic drugs, and also appears to reduce their toxicity in most cases. However, in both animal and patient studies, the major sites of uptake following IV administration consistently appear as the liver and spleen. Preferential tumour uptake has therefore not yet been achieved, althrough a degree of localization of liposomal labels can be demonstrated in the vicinity of experimental animal tumours in certain circumstances. Liposomes may have a future role in cancer chemotherapy, but much laboratory work remains to be done before clinical application can be considered.


Radioimmunoassay for immunologlobulin G in serum and urine.

We describe a radioimmunoassay for immunoglobulin G (IgG) in serum and urine. Aliquots of diluted samples and 125I-labeled IgG were incubated in antibody-coated tubes at 37 degrees C for 24 h, the supernates were decanted, and the radioactivity in tubes containing the bound fraction was counted. The dose-response curve in the range of 0.4--500 mg/L of urine or 640--40 000 mg/L of serum was linear on logit-log transformation and iterative weighted regression. Assay sensitivity was 10 ng of IgG. Validation studies included testing for precision, accuracy, antibody specificity, and parallelism of the dose-response curves for standard and unknown. In a study of 14 apparently normal individuals, serum IgG = 4.0-10.9 gL, urine IgG = 1.1-4.8 mg/24 h, and IgG clearance = 0.2 X 10(-4) to 4.8 X 10(-4) mL/min. In 20 patients with renal allografts, serum IgG = 15.8-66 g/L, urine IgG - 9.6-626 mg/24 h, and IgG clearance = 9 X 10(-4) to 1.99 X 10(-1) mL/min. IgG values correlated well with severity of renal allograft rejection.


Chemotherapy in the management of invasive bladder cancer. A review.

In this review of the management of invasive carcinoma of the bladder the results of primary and systemic therapies are evaluated in the light of the natural history of the disease. The clinical and pathological causes of treatment failure are assessed in an attempt to identify new approaches that may be used in the future management of patients with bladder cancer. To improve survival in this disease requires different approaches to both the control of local disease and the early control of metastatic disease.


Chronic diphenylhydantoin therapy does not reduce plasma 25-hydroxy-vitamin D.

A randomized controlled study was performed to investigate the effect of 2 years' monitored diphenylhydantoin (DPH) therapy on plasma 25-hydroxyvitamin D (25-OHD) in non-epileptic, non-institutionalized subjects. Mean +/- SEM plasma 25-OHD of 18 DPH-treated subjects at the end of 2 years' drug treatment was 59 +/- 8 nmol/l (23.6 +/- 3.2 ng/ml), which was not decreased compared to that of eighteen control subjects (54 +/- 8 nmol/l, 21.6 +/- 3.2 ng/ml). In addition, mean plasma 25-OHD had not changed 1 month after ceasing DPH. The treated group had a higher mean serum alkaline phosphatase (SAP) during DPH treatment, attributable to hepatic enzyme induction. It is concluded that therapeutic doses of DPH without other anticonvulsants do not have a clinically significant effect on plasma 25-OHD.


Piribedil inhibition of prolactin release induced by mechanical breast emptying in puerperal women.

The effects of a 5 day course of Piribedil, a dopaminergic agonist, on prolactin release evoked by mechanical breast emptying in puerperal women, was investigated. A daily dose of 75 mg. caused a significant decrease in the prolactin response to mechanical breast stimulation. Piribedil also proved clinically useful in inhibiting lactation. The role of dopaminergic mechanisms in the regulation of prolactin release induced by mechanical breast emptying are discussed.


Complement fixation in acute serum sickness: assembly of glomerular-bound C3-convertase.

Complement (C) fixing properties of glomerular immune deposits were studied in vitro in two groups of rabbits with acute serum sickness (ASS). Deposits were studied early in decomplemented (cobra venom factor-treated) rabbits (Group I) and during the evolution of the nephritis in non-decomplemented rabbits (Group II). Following perfusion of kidneys of animals from Group I (which contained no autologous C3) with rabbit serum deficient in factor B (classical pathway) or serum pre-treated with Mg++EGTA (alternative pathway), fixation of C3 was observed in both systems. No C3 deposition was found when EDTA-rabbit serum was used. When kidney sections obtained from serial biopsies and autopsy material from Group II (which contained rabbit C3-C3rb) were incubated with purified factors B and D, followed by either purified human C3 (C3hu) or EDTA-guinea-pig serum (C3gp), fixation of C3hu or C3gp to early C3 deposits was observed. When sections were pre-incubated with heat-inactivated rabbit serum (source of C3b-inactivator), C3 fixation was substantially reduced. Little or no C3 fixation was found after incubation of sections with human or guinea-pig serum depleted of factor D (classical pathway). Thus, in ASS, glomerular complement deposition appears to be predominantly dependent on the activation of the alternative pathway (C3b-feedback) which is progressively lost during the evolution of the nephritis.


A study of the aetiology of gastritis following gastric surgery. I. Immunofluorescent studies of the gastric mucosa.

The gastritis which follows surgical trauma is probably not of autoimmune origin. Although identical with the gastritis of pernicious anaemia (PA) upon routine histological examination, immunofluorescent examination of post-operative gastritis differs in that IgA-containing plasma cells alone are found, in contrast to the predominantly IgG-containing plasma cells in PA.


Studies on guinea-pig macrophage migration inhibitory factor (MIF). II. Purification of MIF after treatment with reducing and denaturing agents.

Treatment of guinea-pig macrophage migration inhibitory factor (MIF) containing culture supernatants with the denaturing agents guanidine hydrochloride (Gu HCl) or urea, in the presence or absence of the reducing agent 2-mercaptoethanol (2-ME), or with sodium dodecyl sulphate (SDS), does not destroy biological activity. Alkylation of reduced MIF preparations results in a considerable decrease or total loss of MIF activity. Treatment of supernatants with the combinations, Gu HCl and 2-ME or urea and 2-ME results in the recovery of MIF activity in association with molecules less than 30,000 in molecular weight (mol. wt). After removal of the agents by dialysis, MIF activity is found associated with molecules larger than 30,000. The reduction in mol. wt is dependent on the presence of 2-ME. When MIF-containing supernatants are treated with urea and SDS and fractionated by preparative polyacrylamide gel electrophoresis (PAGE) in the presence of the same agents, MIF activity is recovered in the mol. wt range of 42,000--80,000. When supernatants are treated with 2-me, in addition to urea and SDS, and preparative PAGE is performed in their presence, MIF activity is found associated with material having a mol. wt of 15,000--18,000. Analytical SDS-PAGE of this fraction reveals two or three closely grouped bands corresponding to the above mol. wt range.


Participation of a histamine-Sepharose-adherent subpopulation of human mononuclear cells in the production of leucocyte migration inhibition factor (LIF) in healthy children.

The separation of mouse splenic T lymphocytes into distinct subpopulations by fractionation on histamine-rabbit serum albumin Sepharose (H-RSAS) columns has been described. The H-RSAS-adherent T cells have been attributed regulatory functions associated with B cell activity, T cell-mediated cytotoxicity and the secretion of mediators such as immuno-interferon. The possibility that H-RSAS-adherent T cells exert a similar regulatory effect on an in vitro parameter of T cell-mediated immunity was investigated by assaying the production of leucocyte migration inhibition factor (LIF) in human blood samples, using the agarose droplet method. Phytohaemagglutinin (PHA) and BCG-purified protein derivative (PPD) were used as stimulants of LIF secretion which was measured as a percentage of inhibition of linear leucocytic migration. In normal individuals a highly significant (P less than 0.001) decrease was demonstrated in the production of LIF by peripheral blood leucocytes depleted of H-RSAS-adherent cells. Migration inhibition dropped from 36 +/- 11.7% to 21.2 +/- 12.9% in eighteen cases tested with PHA and from 29.3 +/- 11.7% to 17.2 +/- 9.8% in twelve cases tested with PPD. These results suggest the existence of a lymphocytic subpopulation involved in LIF production which expresses histamine receptors.