Shortened duration of action of 1-deamino-8-D-arginine vasopressin (DDAVP) in patients with diabetes insipidus requiring high doses of peroral antidiuretic drugs.

The antidiuretic effects of graded intravenous and intranasal doses of a new vasopressin analogue (DDAVP) were investigated in two groups of patients with pituitary diabetes insipidus. In the first group, three patients with a high requirement of maintenance doses of peroral anti-diuretic drugs were included; and in the second group, ten patients with a normal (usual) requirement were included. Comparing the antidiuretic responses during 24-hour collection periods, DDAVP, on a microgram basis, was less effective in the "high peroral-dose requirement" patients. The duration of action of single intravenous doses (0.04-24 micrograms) of DDAVP was significantly shortened in the "high peroral-dose requirement" group. However, comparing the peak responses induced by increasing doses of DDAVP in the two groups, there was no demonstrable diminution in the anti-diuretic ability of DDAVP in the "high peroral-dose requirement" patients. Although the possibility of a smaller remnant reserve of ADH was also considered, shortened duration of action ot DDAVP suggests more probably enhanced metabolic breakdown of vasopressin in "high peroral-dose requirement" patients.


The pathogenesis of parvovirus-induced cerebellar hypoplasia in the Syrian hamster, Mesocricetus auratus. Fluorescent antibody, foliation, cytoarchitectonic, Golgi and electron microscopic studies.

Cerebellar histogenesis was studied in hamsters infected at birth with a parvovirus, rat virus strain PRE 308. Cerebellar granule cell precursors in these animals were selectively infected and lysed in the external germinal layer before their migration to form the internal granular layer. The effects of the absence of granule cells on cerebellar development and especially on the development of the Purkinje cells and their dendrites was analyzed using fluorescent antibody. Golgi, conventional paraffin, and electron microscopic methods. This study represents the first Golgi and ultrastructural study of the pathogenesis of rat virus infections in the cerebellum. The destruction of the granule cell precursors resulted in a dysplastic cerebellar hypoplasia with total disruption of normal cerebellar stratification and cytoarchitectonics. The Purkinje cells developed misshapen, progressively disoriented dendritic stems lacking tertiary dendrites and studded with numerous spines, devoid of afferent synaptic contacts (naked spines) and encased by glial processes. These developmental studies, together with the mouse mutant studies, demonstrated that the spines of the Purkinje cells were elaborated in the absence of both tertiary dendrites and afferent parallel fiber contacts. Such data suggested that spine formation, once triggered, was intrinsically programmed rather than being dependent on the development of parallel fiber contacts. Despite the loss of a major interneuronal component and disintegration of normal cytoarchitectonic relationships, synapses in the cerebellar cortex developed normally as long as both the pre- and post-synaptic elements were present. Thus synaptic specificity is maintained in the face of gross disruption of cytoarchitectonic relationships. If either the pre- or post-synaptic portion of a contact was absent, then glial processes isolated the persisting element or aberrant contacts formed. In addition to glial encasement of naked spines, there were dendrodendritic articulations between Purkinje cell dendrites, some of which were joined by septate, plaque-like junctions. Aberrant synaptic contacts between mossy and climbing fiber glomeruli and the smooth surface of the Purkinje cell somata were found rarely. In addition to these contacts which also occur in the hypoplastic cerebella produced by other methods, previously undescribed non-synaptic spine-articulations between Purkinje cell dendrites were seen. The role played by granule cells and their axons in Purkinje cell development appeared to be two-fold. First, the development of the orderly array of parallel fibers in the normal animal played a role in orienting and flattening the dendritic trees of Purkinje cells. Second, the formation of tertiary dendritic branches appeared to depend primarily upon the presence of an external germinal layer throughout this stage of Purkinje cell development. By contrast, dendritic spines developed and persisted in the absence of granule cells.


Isolation of sialic acid from casein and reclamation of residual casein.

Crystalline sialic acid was isolated in 50 to 60% yields from a commercial grade of dry isoelectric casein by Warren's hydrolysis procedure. One part of casein was heated at 80 C/60 min in ten parts of .18 N sulfuric acid (pH 1.5). A crude sialic acid preparation (7.8%) was obtained from the hydrolysate after addition of calcium hydroxide to remove protein at pH 4.6 and sulfate as calcium sulfate at pH 7.0 followed by concentration and lyophilization of the soluble material. Highly purified sialic acid (95%) was obtained by chromatography on Dowex-1 X 8 with a gradient of 0 to 2 M sodium acetate. The sialic acid positive fraction was passed through Duolite C20H followed by lyophilization. Slow evaporation of a concentrated solution of this material produced typical crystals of N-acetylneuraminic acid. The study also included an examination of the properties of the residual sialic acid-free casein. Electrophoretic patterns, solubility properties, rennet sensitivity, and viscous character revealed that the residual casein was remarkably similar to intact casein. However, the calcium sensitivity of this modified protein was increased in the presence of .1 M calcium chloride.


Effect of intravenous L-isoleucine infusion upon concentration of free isoleucine in milk.

The growth of Streptococcus agalactiae in milk is inhibited by elevated free isoleucine. Free amino acid concentrations in both plasma and milk from three lactating dairy cows were studied after intravenous infusions of L-isoleucine at 62, 300, 380, and 840 mumol/kg of body weight. Free isoleucine was lower in milk than in plasma. The concentration of free isoleucine in plasma increased after infusions of isoleucine at the three higher amounts. The highest concentration of free isoleucine in milk measured was 1.5 mumol/100 ml of skin milk. This was observed after infusion of isoleucine for 12 h at 380 mumol/kg of body weight. Free isoleucine in both plasma and milk dropped to the preinfusion concentrations a short time after the isoleucine infusions were stopped. When relatively large quantities of isoleucine were infused into the blood of cows, free isoleucine in blood increased as much as twofold. The source of free isoleucine in milk appeared to be free isoleucine in plasma, but isoleucine in milk only reached concentrations that would give about 50% of the growth inhibition of S. agalactiae obtainable with isoleucine in vitro. It would be difficult to elevate free isoleucine in milk by dietary manipulation sufficiently to inhibit S. agalactiae.


Direct bonding applied to space maintenance.

Based on the conditions of this study, the following conclusions were reached: A success rate of 70 percent seems to justify further investigation into direct bonded space maintainers. A space maintainer directly bonded to the buccal surfaces seems to be efficient in maintaining single tooth spaces. Primary-to-primary appliances were more successful than the primary-to-permanent appliances, which suggests that incomplete first permanent molar eruption and a posterior location affect appliance durability.


In vitro retentive strength of fixed bridges constructed with acrylic pontics and an ultraviolet-light-polymerized resin.

The in vitro retentive strength of 24 test bridges was studied. The bridges were maxillary canine to central incisor spans, and an acrylic pontic replaced the lateral incisors. The pontic was retained by a resin polymerized with ultraviolet light. The mean forces necessary to dislodge the pontic bonded to natural teeth in the three-unit bridges were determined to be 41.5 lb for a force applied toward the incisal edge and 55.8 lb for a force applied toward the gingival ridge. A promising clinical application of this technique is suggested.


A brief review of some properties of alpha-methylnorepinephrine.

The research literature can be confusing because of the vast number of nonproprietary names used by various authors for a specific drug. An attempt is made here to clarify the ambiguity regarding the stereoisomer, (-) erythro-alpha-methylnorepinephrine. This agent is used in dentistry as a vasoconstrictor (Neo-Cobefrin) and although its pharmacologic activilty is weaker than that of (-) norepinephrine, it appears that this agent can have significant pharmacologic effects at higher doses. Effects reported have consisted of decreased or increased blood pressure because of the activation of beta receptors or alpha receptors, respectively.


Clinical evaluation of the phase contrast microscope as a motivational aid in oral hygiene.

In a pilot study, phase contrast microscope and plane microscope demonstrations of plaque were compared in two controlled groups to evaluate their relative effect on long-term motivation toward good oral hygiene. Plaque and calculus scores were used as indexes. During a seven-month period, the group using the phase contrast microscope showed statistically significant imporvement in plaque scores compared with the group using the plane microscope. However, the difference in actual plaque amounts between groups was of a small magnitude and cannot be considered clinically significant. Both groups showed significant statistical improvement in plaque scores at seven months as compared with pretests socres. This maintained plaquereduction at seven months was of a magnitude that could be clinically significant.


Treatment of ragweed hay fever with an intranasal spray containing fluinsolide, a new synthetic corticosteroid.

Flunisolide, a new synthetic fluorinated corticosteroid, was administered as a nasal spray via a squeeze bottle to patients with ragweed hay fever for 4 wk during the hay fever season. Fifty-one patients, paired on the basis of similar skin sensitivity to intradermal ragweed (greater than or equal to 10-1 PNU/ml), were randomly assigned in a double-blind manner either an aerosol-containing flunisolide dissolved in vehicle (a mixture of polyethylene glycol and propylene glycol) or vehicle alone. Flunisolide was sprayed as a 0.025% solution two times in each nostril twice a day. Forty-eight patients completed the study. Three patients dropped out for reasons unrelated to flunisolide usage. On the basis of physician interviews and daily symptom dairy scores, patients receiving flunisolide showed significant improvement of hay fever symptoms when compared to their counterparts receiving vehicle. No systemic steroid side effects were observed. Morning plasma cortisol levels measured prio to and after 3 wk of flunisolide therapy showed no significant difference between the treatment groups. Adverse local effects were minor and were noted less frequently with flunisolide than with vehicle. Flunisolide's topical efficacy and lack of adrenal suppression provide distinct advantages over other steroid preparations available in the United States for treatment of seasonal allergic rhinitis.


Diet therapy in the U.S. in the past 200 years. A Bicentennial study.

Although diet therapy is a concept of the twentieth century, its foundations were laid by such men as Sanctorius in the sixteenth century, Lavoisier in the eighteenth century, and Beaumont in the nineteenth century, whose detailed notes reflected amazingly accurate observations. With the advent of scientific medicine, research provided the knowledge on which diet therapy was built. Data on food composition, which began to be available around the turn of the century, was important to the therapeutic dietitian, and, at mid-century, formed the basis for the development of the first Exchange Lists (only revised this year). Diets early in the century involved rigid routines, in contrast with the trend today to consider the individual. World War I marked the emergence of the trained dietitian and changes in diet therapy, as knowledge of the biologic sciences and the practice of medium expanded. Research on metabolism led to control of hemoglobin and the red cell anemias, while growing knowledge of the role of pancreatic secretions in metabolism made near-normal lives possible for those with diabetes. The dietitian today finds herself in the position of interpreter of scientific findings, developing meal patterns which not only correct poor food habits but are acceptable to patients. More recently, she has been concerned with problems in modification of fat intake in the interest of possible prevention of cardiovascular disease. Obesity and its prevention remain problems. The practice of diet therapy is subject to vogues, as is science, but the challenge to the dietitian remains: that of serving each patient through the best possible use of her education, skill, and sensitivity.


Dietary fiber--in historical perspective.

Epidemiologic reports have linked how intakes of dietary fiber with numerous diseases and abnormal conditions. They range from diverticulitis to coronary thrombosis, from simple constipation to possible carcinoma of the colon. The supposed etiology underlying these and other conditions is discussed in terms of the properties of cellulose, lignin, and hemicelluloses, including pectin, which collectively make up dietary fiber. Other major organic components of plant foods, apart from fiber, protein, fat, sugars and starches, are considered briefly. The desirability of improved nomenclature is emphasized. Urgently needed is a thorough study of the biochemistry and metabolism, using experimental animals, of dietary fiber in foods. Only when this is done can there be a good understanding of the mechanisms involved and a realization of the possibilities suggested by the epidemiologic studies.


Ascorbic acid and fractures in children with myelomeningocele.

Ascorbic acid intake of sixty-seven patients with myelomeningocele, ages one through eight years, was evaluated in two groups, fracture and non-fracture, to compare their intake of ascorbic acid from food-plus-supplement, food-only, and supplement-only with the recommended allowances. Intake from food-plus-supplement exceeded the allowance for 90 per cent of the fracture and 83 per cent of the non-fractured patients. Intake from food-only exceeded the recommended allowance in 79 per cent of the fracture and 75 per cent of the non-fracture subjects. All supplementations exceeded 100 per cent of the recommended allowance. There was no significant difference in the ascorbic acid intakes of fracture and non-fracture patients. Since there was no apparent correlation between fractures and ascorbic acid intake, we do not recommend ascorbic acid supplementation to prevent fractures. If such high levels are suggested, the potentially harmful effects of excessive ascorbic acid in growing children must be carefully considered.


Some factors that may alter consumption of animal products. A review.

Trends in consumption of animal products are discussed, including reasons for changes. Although consumption of some products has increased--notably that of broilers and beef--for other products, it has declined, i.e., total dairy products and eggs. Evidence shows that consumers desire a lower fat content in both meat and dairy products, although, in the case of meat, minimal levels are necessary for palatability. Overall, it is suggested that consumers are concerned with nutritional quality and are influenced by health-related concerns. The use of vegetable proteins as extenders and substitutes for animal proteins is reviewed, with the conclusion that they will continue to influence consumption of animal products.


Plasma protein immunocytochemistry and polysaccharide cytochemistry at the surface of alveolar and endothelial cells in the rat lung.

Ultrastructural immunocytochemistry of plasma proteins and cytochemistry of polysaccharides with ruthenium red and concanavalin A were combined with different types of fixation with or without prior vascular or airway washing, to study the surface of capillary endothelial and alveolar epithelial cells of the blood-air barrier in the rat lung. The endothelial and epithelial cell surface layers were found to have two components: a moveable part belonging to the cellular microenvironement made of plasma proteins and a deeper glucidic or anionic fixed part bound to the plasma membranes (cell coat).


[Simultaneous study of the placental, myometrial and cervical circulations (indium 113 and anemometric thermometry). 3). Double blind study of the action of intravenous ritodrine during normal pregnancy].

The authors measure the changes in placental and myometrial blood flow using an isotope technique with Indium 113. They calculate an index of the variation in placental blood flow (I.V. D.P.) and an index of variation of myomoetfrial blood flow (I.V.D.M.) after injecting Ritodrine or a placebo between the 28th and the 36th week of pregnancy. This study was carried out in 26 normal women. At the same time using Brotanek's technique changes in the cervical blood flow were registered. No change in the placental, myometrial or cervical blood flows were noted while Ritodrine was being transfused intravenously.


[High risk factors of breast cancer].

The authors analyse the various high-risk factors for breast cancer which have been described by many authors and their relative importance and intricacies. Some of these factors are concerned with the age of the patient, some with the time the periods started, some with the time the menopause occured and whether this was natural or artificial.


Salmonella in the American cockroach: evaluation of vector potential through dosed feeding experiments.

Restrained American cockroaches, Periplaneta americana L., were fed graded doses of Salmonella typhimurium ranging from 1-6 X 10(3) to 2-0 X 10(6), and their faeces assayed daily for the pathogen. Only 4 specimens out of 117 demonstrated multiplication of salmonellas, which was unrelated to size of input. When data of persistence regardless of actual numbers were expressed as percentage Salmonella-positive faecal-days, and these transformed to probits, a graph of percentage-positive faecal-days versus log dose allowed a calculation of the CD 50, or contaminative dose required for 50% of the faecal-days to be infective. The CD 50 for this cockroach species was 1-4 X 10(6) Salmonella.


Effect of various milk feeds on numbers of Escherichia coli and Bidifobacterium in the stools of new-born infants.

Escherichia coli was found in a similar proportion of stool specimens from infants who were breast-fed and from others fed on three different artificial-milk preparations. When E. coli was present its mean colony count in the stools of breast-fed infants was within the range of the mean counts for infants receiving the artificial -milk feeds. There was no consistent relation between high counts of bifidobacteria (Lactobacillus bifidus) and low counts of E. coli. This suggests that measures aimed at implanting or stimulating the growth of bifidobacteria in the large intestine of artificially fed infants may not greatly influence the E. coli population therein. The results are discussed in relation to the protection of artifically fed infants from E. coli enteritis.


A modified haemagglutination inhibition test for rubella antibodies, using standardized, freeze-dried reagents. Report of a comparative multi-centre trial.

A modified haemagglutination inhibition test for rubella antibodies, using standardized freeze-dried reagents, was developed and compared with haemagglutination inhibition tests using fresh erythrocytes. This comparison was made in collaboration with six European laboratories. A total of 4205 serum samples were tested. The results show that: (1) Sensitivity and reliability of the modified test are good; (2) the modified test can be performed in polystyrene microtitration plates.


Modified Vi tests in the screening of typhoid carriers.

Two tests for the estimation of Vi antibody in sera were studied and their validity in the screening of typhoid carriers was assessed. One was a modified Vi haemagglutination test in which Vi-coated glutaraldehyde-fixed erythrocytes were used as the antigen and Vi antibody resistant to treatment with 2-mercaptoethanol was titrated. The other was a fluorescent Vi antibody test in which acetone-fixed bacterial Vi cells were used as the antigen and the total Vi antibody was titrated. In both tests, the antigens used were stable so that standardization of the tests would not be difficult. The modified Vi haemagglutination test was found equally sensitive but more specific in giving less false positives than the conventional Vi haemagglutination test. The fluorescent Vi antibody test was however found superior to both tests not only in giving less false positives but also in detecting more typhoid carriers.


Comparison of cotton swab versus algiante swab sampling method in the bacteriological examination of broiler chickens.

Comparison of bacterial counts of poultry carcass skin by the cotton swab and alginate swab methods showed no differences between the two sampling methods in total counts and Enterobacteriaceae counts. Also no differences were found in Salmonella isolations.


Appearance of functional lymphocytes in fetal liver.

During ontogeny of the mouse, cells bearing surface Ig first appear at approximately 16 days of gestation. To characterize B cell differentiation during embryogenesis further, we have measured several functional activities of B cells and their precursors. B cell function was measured in two assays, response to sheep red blood cells in a transplantation assay, and response in vitro to a B cell mitogen. By both assays, B function is first detectable at 16 days, the same time that Ig-positive cells appear. The immediate precursors of B cells, PB cells,3 can also be measured by a transplantation assay. This activity is first detectable in fetal liver at 13 days. The yolk sac at 13 days does not contain significant PB activity even though both fetal liver and yolk sac contain pluripotent stem cells, spleen colony-forming units, at that time. Tese data are consistent with the hypothesis that the development of B lymphocytes occurrs early in ontogeny and that the fetal liver may provide the inductive stimulus for B cell maturation.


Perturbation of lymphocyte circulation in experimental murine leprosy. I. Description of the defect.

Infection of Lewis rats with Mycobacterium lepraemurium is characterized by granulomatous pathology primarily involving the paracortical areas of lymph nodes and periarteriolar lymphocyte sheaths of the splenic white pulp. Intravenous infusion of radiolabeled thoracic duct lymphocytes (TDL)2 from normal syngeneic donors failed to produce a significant increase of cell output and radioactivity in the thoracic duct lymph of infected rats as compared with a marked increase in matched control recipients. Conversely, the migration of TDL from infected donor rats was normal in uninfected control rats that had been infused with serum from infected donors. The onset of the lymphocyte traffic disturbance takes place between 2 and 6 weeks after inoculation of viable M. lepraemurium. However, inoculation of heat-killed organisms produces little perturbation of lymphocyte circulation. Thus, the abnormal circulation of TDL in rats with active infection appears to be secondary to granulomatous pathology in lymphoid organs that disturbs cell traffic through these organs.


Perturbation of lymphocyte circulation in experimental murine leprosy. II. Nature of the defect.

Intravenous infusion of radiolabeled thoracic duct lymphocytes (TDL)2 from normal syngeneic donors to rats experimentally infected with Mycobacterium lepraemurium fails to produce a significant increase of cell output and radioactivity within the thoracic duct lymph. Conversely, ther is a marked increase in cell counts and radioactivity in the thoracic duct lymph of control recipients. Splenectomy of infected rats prior to the infusion significantly increased the ouptut of cells and radioactivity from the TD of these rats although it was not restored to normal. Serial quantitation of radioactivity in lymphoid organs of infected rats after infusion of 51Cr-labeled TDL revealed significantly increased uptake by the spleen as compared with the spleens of controls. Thus, the spleen of infected rats was a major trap for recirculating TDL. TDL were also trapped to a lesser extent by the lymph nodes and liver of infected rats. The circulation of TDL was not disturbed significantly in control rats with massive splenomegaly and red pulp hyperactivity induced by i.p. injection of methyl cellulose. Since murine leprosy preferentially involves the periarteriolar lymphocyte sheaths of the splenic white pulp and paracortical area of lymph nodes, it is suggested that the disturbance of lymphocyte circulation is secondary to pathology within these areas.


Cross-reactions between 2, 4-dinitrophenyl and menadione (vitamin K3) and the general problem of antibody specificity.

Early and late antisera to 2, 4-dinitrophenyl (DNP) and to menadione (K3)4 were compared for reactivity with diverse DNP and K3 ligands. Late antisera were generally more reactive (higher affinity) than early antibodies. Nevertheless, the early antibodies had higher affinity for homologous ligands than late antibodies had for heterologous ligands; the exception, a small (ca. 5%) and possibly heteroclitic subset from late anti-DNP sera, had higher affinity for K3-butyrate than for DNP-lysine. Early antisera appeared to be more specific than late antisera by one criterion (the precipitin reaction), but less specific by a more fundamental criterion (KO/KX, the ratio of intrinsic affinities for homologous and cross-reacting ligands). By several methods (precipitation, binding to heterologous immunoadsorbants) 25 to 75% of the antibodies in both anti-DNP and anti-K3 sera were cross-reactive; even more cross-reactivity was evident by equilibrium dialysis, where it appeared that virtually all anti-DNP antibodies can bind K3 and that virtually all anti-K3 can bind DNP. This extreme level of cross-reaction is not as "strange" as was once thought, it seems unwarranted to regard this cross-reaction as support for the view that antibodies in general are multispecific.


Demonstration of human nephritogenic tubular antigen in the serum and organs by radioimmunoassay.

Nephritogenic tubular epithelial antigen (Tub-Ag), which had been found in immune complexes deposited along the glomerular capillary walls of some patients with idiopathic membranous glomerulonephritis, was solubilized from renal tubuli of humans by Pronase digestion. Soluble Tub-Ag was then purified by gel filtration and ion exchange chromatography on DEAE-Sephadex. Three DEAE fractions, designated as 0.07 M, 0.13M, and 0.23 M fractions, raised antibodies in rabbits and fluoresceinated antibodies against any of these fractions reacted exclusively with luminal layer of proximal tubular epithelia. Among three fluoresceinated antibodies, however, only the one directed to 0.07 M fraction bound with immune complexes which were deposited along the glomerular capilary walls of the patients with Tub-Ag (DEAE 0.07 M fraction) was physicochemically homogenous with a S20 value of 8.2. Utilizing 125I-labeled Tub-Ag, a sensitive and quantitave radioimmunoassay of Tub-Ag was developed. Tub-Ag was demonstrated to occur naturally in serum and urine, as well as in all the organs tested including kidney, intestine, liver, spleen, stomach, heart, and lung. Tub-Ag was detected even in the sera of anephric patients on maintenance hemodialysis (60.8 +/- 7.8 radioimmunoassay units/ml), although at slightly lower levels than in those of normal individuals (69.9 +/- 10.6 units/ml). The size of serum Tub-Ag was identical to that of molecules bearing Tub-Ag activity solubilized by Pronase from all the organs tested, indicating that circulating Tub-Ag was maintained mainly by organs other than kidneys.


Comparison of the pyrogenicity, Limulus activity mitogenicity and complement reactivity of several bacterial endotoxins and related compounds.

The correlation of mitogenicity, complement activation, pyrogenicity and Limulus amebocyte lysate (LAL) gelation induced by 17 bacterial endotoxins (LPS), modified endotoxins, related compounds, and other B cell mitogens was examined. With the use of these compounds, a significant correlation was found between pyrogenicity and mitogenicity (r = 0.85, p is less than 0.0005), pyrogenicity and LAL reactivity (r = 0.84, p is less than 0.0005), and mitogenicity and LAL reactivity (r = 0.72, p is less than 0.0025). In contrast, complement activation by these compounds did not correlate with mitogenicity, pyrogenicity or LAL reactivity (r = 0.09, p is greater than 0.4; r = -0.17, p is greater than 0.3; r = 0.17, p is greater than 0.3, respectively). These results suggest that a specific chemical configuration may induce mitogenicity, pyrogenicity, and LAL reactivity which differs from that responsible for complement activation.


In vitro responses of CBA/N mice: spleen cells of mice with an X-linked defect that precludes immune responses to several thymus-independent antigens can respond to TNP-lipopolysaccharide.

Spleen cells from CBA/N mice with an X-linked B cell defect were examined for their ability to form antibody in vitro after stimulation with the T-independent antigen TNP-LPS. In contradistinction to their failure to respond to some conventional T-independent antigens such as type III pneumococcal polysaccharide or DNP-AECM-Ficoll, spleen cells from (CBA/N X DBA/2)F1 male mice were able to make a specific anti-TNP PFC response after culture with TNP-LPS. Their response differed from that of phenotypically normal (CBA/N X DBA/2)F1 female littermate spleen cells in that more TNP-LPS was required to elicit the peak anti-TNP response and the anti-TNP antibody secreted by F1 male cells was of lower avidity than that of F1 female cells. The polyclonal antibody response to unsubstituted LPS did not differ substantially between normal and defective B cells. Tnymus-derived cells were not required for the TNP-LPS response by either F1 male or female cells. We conclude that CBA/NB cells can respond to certain T-independent antigens that are able either to induce a very strong activating signal upon ligand-surface receptor interaction and/or to stimulate immature B cells (with a characteristic high surfact immunoglobulin profile) which fail to respond to antigens like DNP-AECM-Ficoll.


Antibody quantitation using an immunoadsorbent and the unlabeled antibody enzyme method.

Measurement of specific immunoadsorbent-bound antibodies has been accomplished by the unlabeled antibody enzyme method (Sternberger et al., 1970). Sepharose-4B containing specific antigen (or ligand) is treated with diluted specific immune serum (primary serum), such as 1 ml of serum diluted 6000-20,000 fold. followed by antiserum against immunoglobulin G (IgG) of the primary serum and then by peroxidase-antiperoxidase (antigen-antibody) complex (PAP) derived from the same species as the primary serum. Radiolabeled primary antibody and anti-IgG have confirmed the stoichiometry of the reaction. The immunoabsorbent binds the antibody of interest quantitatively and to equal extent after 15 min or 48 h. The enzymatic activity of the PAP complex followed a direct linear relationship to its concentration indicating the stability of binding in the PAP complex. A direct relation between the enzymatic activity measured when both the primary antiserum and the anti-IgG are used allows for quantitation of the antibody level of the primary serum.


Density gradient electrophoresis of mouse spleen lymphocytes: separation of T and B cell fractions.

Preparative electrophoresis in an isotonic Ficoll--sucrose density gradient has been employed for the separation of mouse (C57Bl/6J) spleen lymphocyte subpopulations. The separated cells were pooled into six fractions according to their relative position (Rp) within the total cell distribution. In general, the high mobility cells were identified as T lymphocytes. These cells exhibited immunofluorescence upon reaction with fluorescein isothiocyanate-conjugated mouse anti-theta globulin and responded in vitro to phytohemagglutinin stimulation. The low mobility cells were activated in vitro by E. coli lipopolysaccharide and showed immunofluorescence upon reaction with fluorescein isothiocyanate-conjugated anti-mouse Ig which is typical of mouse B lymphocytes. Both T and B cells were completely isolated from each other in certain fractions of very high and very low mobility, respectively. Overlapping of the two distributions was observed in the intermediate mobility fractions. The method which utilizes an inexpensive commercially available apparatus should be useful for the preparation of other lymphocyte subpopulations differing in surface charge.


The use of immunoprecipitation to study the synthesis and cleavage processing of viral proteins.

Several factors have been considered in developing an immunoprecipitation procedure which minimizes the background of non-immunospecifically precipitated protein. The procedure evolved utilizes the technique of direct immunoprecipitation (specific antibody plus sufficient unlabeled antigen to form a precipitable complex). High speed centrifugation of the cell extract immediately prior to immunoprecipitation and the use of test tubes coated with silicone greatly reduced background precipitation.


Passive hemagglutination procedure for group A streptococcal polysaccharide.

A passive hemagglutination procedure for detection of antibody to group A beta-hemolytic streptococcus polysaccharide is described. The polysaccharide was conjugated to human gamma globulin and the complex adsorbed onto stabilized human erythrocytes. Antigen coated cells were used to measure antibody levels in normal human sera and in rabbit antisera.


The significance of 125I as a tracer for lymphocytes, liver cells and erythrocytes after iodination by the lactoperoxidase-H2O2 technique.

Human erythrocytes, porcine and rat liver cells, porcine spleen lymphocytes and cultured human lymphoma cells (266 Bl) have been labelled with 125I by the lactoperoxidase-H2O2 method. Large amounts of radioactivity were released when the iodinated cells were incubated in different buffers, and the rate of the release varied considerably between the different cells. Incubation at a higher temperature increased the release rate, while metabolic inhibitors such as iodoacetamide, trasylol or sodium azide did not. When collagenase was used during the preparation of spleen lymphocytes, the rate of the radioactivity release was decreased about 50%. Several findings indicated that the released radioactivity originated from free iodide. When the labelled lymphocytes were treated with a nonionic detergent, Nonidet P-40, 90% of the total radioactivity was solubilized. Only 10-15% of the radioactivity was stably bound in macromolecular material. The remaining part, corresponding to the amount of radioactivity released during incubation, was shown to be free iodide. It is concluded that the significance of the 125I-label in living cells has to be studied in each case at the specific experimental conditions used. After the unspecifically trapped iodide is released--normally after about 2 h--the label is considered to be useful for studies with intact cells.


Measurement of chemotaxis of human polymorphonuclear leukocytes in filters by counting the number of cells in a single plane and comparison with leading front method.

A method is described for measuring the chemotactic response in filters of human neutrophils by counting the number of cells in a single plane at a constant distance below the top of the filters. This method gives results that are similar to those obtained by counting the total number of cells that have migrated into the filters. The results obtained by this method are compared with the leading front method. Under most conditions the results are similar whether obtained by the leading front or cell number methods except that counting the number of cells is often more sensitive. In the presence of p-nitrophenyl 4-chlorobutylphosphonate, however, the chemotactic response appeared to be inhibited as determined by counting the number of cells stimulated to migrate but enhanced as measured by the leading front method.


Cenetic and immunological aspects of litter size in the mouse.

The effects of antigenic differences between mother and fetus on implantation number and on post-implantation mortality were studied. No evidence was found to support the hypothesis that these two measurements were affected by such antigenic differences or by prior immunization of the mother to paternal antigens.


Lamellar ichthyosis: long-term graft studies on congenitally athymic nude mice.

Whole-skin grafts from a patient with lamellar ichthyosis were maintained on athymic nude mice for periods of 6 weeks to 4 months with excellent preservation of all gross and histologic features of the disease. In recombinant grafts composed of lamellar ichthyosis epidermis and normal dermis grown for periods up to 87 days on nude mice, the abnormal epidermis retained all the features of lamellar ichthyosis. Similar results were found in recombinants of lamellar ichthyosis epidermis and dermis. In recombinant grafts of normal epidermis and lamellar ichthyosis dermis, the epidermis remained normal and did not become ichthyotic. These observations support the hypothesis that the defective gene in lamellar ichthyosis acts directly on the epidermis as opposed to acting indirectly through a systemic abnormality or through an effect on neighboring dermis.


Ultraviolet-induced dna repair synthesis in lymphocytes from patients with actinic keratosis.

Actinic keratosis is an epidermal cancer in situ. Extensive exposure to sunlight is considered as a contributing factor to the etiology of this tumor. Ultraviolet (UV) light of solar radiation induces structural damage in DNA, which may give rise to mutations and transformed cells if the damage is not repaired. Repair of UV-induced DNA lesions is an essential property of human cells. The conditions so far reported to have defective DNA repair are all associated with an increased incidence of malignancy. Do patients with actinic keratosis also exhibit a reduced capacity to repair UV-induced DNA lesions? DNA repair synthesis in peripheral leukocytes was studied in 10 patients with actinic keratosis and 10 healthy subjects of corresponding age. After irradiation with various doses of UV light the leukocytes were incubated for 2 hr with [3H]thymidine in the presence of hydroxyurea. A dose-response relationship for the UV-induced DNA repair synthesis was established for each individual. The average repair capacity in the patients with actinic keratosis was about 30% below that of the controls. The difference is statistically significant (p less than 0.02). Reduced DNA repair synthesis may therefore be an important factor in the etiology of actinic keratosis.


Rubidium release: a rapid and sensitive assay for amphotericin B.

A new assay for amphotericin B has been devised with use of the release of a radioactive potassium analogue (86rubidium; 86Rb) from Candida parapsilosis. The 86Rb-release assay is rapid, highly sensitive, and reproducible. Amphotericin B levels of 0.06-2.0 mug/ml can be measured in serum, whereas as little as 0.015 mug of amphotericin B/ml can be detected in spinal fluid. The greater sensitivity of the assay in spinal fluid as compared with that in serum may be the result of binding of the amphotericin molecules by serum components, thus decreasing the amount of amphotericin free to interact with the fungal membrane.


beta-Lactamases and resistance to penicillins and cephalosporins in Serratia marcescens.

Strains of Serratia marcescens fall into one of two groups with respect to their resistance to  to beta-lactum antibiotics. Most strains are highly resistant to cephalosporins but are significantly more susceptible to ampicillin and carbenicillin, whereas other strains are highly resistant to both penicillins and cephalosporins. Strains in the former category produce small amounts of an inducible cephalosporinase, which appears to be chromosomally mediated. Strains in the latter class also elaborate large amounts of a noninducible penicillinase-cephalosporinase, which is plasmidmediated. Ability to produce this type of enzyme can be transferred to Klebsiella pneumoniae or Escherichia coli and may be lost spontaneously or after exposure of S. marcescens to "curing" agents.


The eosinophil stimulation promoter test in murine and human Trichinella spiralis infection.

A test for the lymphokine eosinophil stimulation promoter (ESP) has been adapted to the study of Trichinella spiralis infections in mice and has been used as an aid in the diagnosis of trichinosis in a patient. With use of soluble antigen extracted from T. spiralis larvae and peritoneal exudate cells rich in eosinophils obtained from mice with trichinosis of four weeks' duration, a dose-response curve was constructed and analyzed. The soluble larval antigens greatly enhanced the migration of eosinophils from the mice with trichinosis but had no effect on the eosinophils from mice with schistosomiasis, nor did soluble schistosome egg antigens have any effect on the cells from mice with trichinosis. On two occasions peripheral white blood cells from a patient with presumed T. spiralis infection gave strongly positive results in ESP tests on stimulation with soluble larval antigen, but the cells did not respond significantly to soluble schistosome egg antigen; the result in the ESP test was positive before the patient's serum produced a weakly positive agglutination response.


Nocardial infections in the United States, 1972-1974.

A survey of members of the Infectious Diseases Society of America indicated that nocardial infections are not rare. Probably between 500 and 1,000 cases are recognized in the United States each year, of which 85% are serious pulmonary or systemic infections. Although nocardial infections are usually opportunistic infections in the compromised host, at least 15% of the infections in this series occurred in patients without a definable predisposing condition. Nocardial infections occurred in a random geographic distribution within this country, with affected males outnumbering females by 3:1. Most patients were between the ages of 21 and 50 years; however, the age range was broad. The number and variety of infections caused by Nocardia species other than Nocardia species other than Nocardia asteroides have been underestimated. Between 8.6% and 18.8% of pulmonary-systemic infections in this series were caused by species of Nocardia other than N. asteroides.


Effect of culture media on the antifungal activity of miconazole and amphotericin B methyl ester.

The capacity of four culture media to obfuscate the antifungal activity of miconazole and amphotericin B methyl ester was evaluated qualitatively by examination of five isolates each of Candida albicans, Candida tropicalis, Candida parapsilosis, Torulopsis glabrata, and Cryptococcus neoformans, and quantitatively by determination of the absolute minimal inhibitory concentrations for a strain of C. albicans. Miconazole, like the predecessor imidazole (clotrimazole), was antagonized by two complex, undefined media (Sabouraud's glucose and brain-heart infusion agars) but not by either of two synthetic formulations (synthetic amino acid medium, fungal and modified yeast-nitrogen base). The antifungal activity of amphotericin B methyl ester, like that of the parent compound amphotericin B, was not materially affected by the culture medium used for testing. When added separately to synthetic amino acid medium (fungal), neither purines nor pyrimidines antagonized miconazole. Ether extraction of Sabouraud's glucose agar failed to diminish the antagonism of this medium for miconazole.


Specific and Nonspecific immunity to Serratia marcescens infection.

By specific active or passive immunization, mice were protected against lethal infection with Serratia marcescens. Animals that were immunized against organisms of the challenge strain O serotype survived, whereas animals that were immunized against other serratia O serotypes did not survive. Protective sera (from convalescent partients or immunized rabbits) contained a specific complement-independent opsonin. These sera also contained passive hemagglutinating and bacterial agglutinating antibodies in high titer. The protective and complement-independent opsonizing antibodies were associated with IgG fractions of the serum, while the agglutinating antibodies were primarily associated with the IgM. Mice also survived infection with Serratia after immunization against the Re595 Salmonella minnesota mutant. However, complement-independent opsonizing antibody was not demonstrated in these cross-protective sera.


Resistance to chloramphenicol and ampicillin of Salmonella typhimurium in Ontario, Canada.

Combined resistance to chloramphenicol and ampicillin in Salmonella typhimurium is appearing in Canada. Five cases of this type of infection have been noted. The isolates are resistant to streptomycin, sulfonamides, and tetracycline, in addition to ampicillin and and chloramphenicol; four isolates are also resistant to kanamycin. In each isolate the determinant for chloramphenicol resistance is linked to a conjugative plasmid. Four of the chloramphenicol plasmids appear to be related in resistance pattern, level of antibiotic resistance mediated, and temperature sensitivity of mating ability. The same four plasmids are associated in the primary isolates of Salmonella with three different kinds of genetic units mediating resistance to ampicillin. In only one of the five strains are the genes for chloramphenicol and ampicillin resistance linked in the same plasmid.


Variation in urease activity of endemic hospital strains of Proteus rettgeri and Providencia stuartii.

Both urease-positive and urease-negative Proteeae isolated from cross-infected patients in the same hospitals and, in three cases, from the same patients were examined for their biochemical reactions and somatic (O-) antigens. All isolates gave the same reactions in 17 biochemical tests and possessed O-antigens characteristic of Providenic O-type strains 4 or 17. Study of the isolates indicated that endemic strains are capable of undergoing variation in urease activity. In the current classification urease-positive and urease-negative strains are classified as Proteus rettgeri and Providencia stuartii, respectively. The observed variation in urease activity of nosocomial isolates of Proteeae suggests that taxonomy should be modified so that all such strains would be accommodated in a single group.


Comparative efficacy of neuraminidase-specific and conventional influenza virus vaccines in induction of antibody to neuraminidase in humans.

Groups of college students received either conventional A/England/42/72 (H3N2) vaccine (X-37), an antigenic hybrid (Heq1N2) vaccine (X-38) containing the same neuraminidase (and thus effectively neuraminidase-monospecific), or a placebo injection. The vaccines contained 798 and 643 chick cell-agglutinating units per dose, respectively, and equivalent immunogenic units of N2 as defined in antigenic extinction tests in rabbits. All subjects had antibody to N2 before immunization, and mean initial titers were comparable in both vaccine groups. Homotypic hemagglutination-inhibition response to vaccine hemagglutinin was slightly more frequent (77%) but of lower magnitude in the students vaccinated with X-38 than in those vaccinated with X-37. Significant antibody response to N2 was observed in 25% of those vaccinated with X-37 and in 69% of those vaccinated with X-38. Mean antibody response to N2 was twofold greater in those vaccinated with X-38. Heterotypic hemagglutination-inhibition was seen in 56% of those receiving X-38 vaccine. In preliminary plaque-inhibition titrations this heterotypic antibody did not have neuralizing activity. Testing of antibody response to N2 with earlier neuraminidase antigens demonstrated "original antigenic sin" from earlier priming. The superiority of the "neuraminidase-specific" X-38 (Heq1N2) vaccine as an immunogen for antibody to neuraminidase may reflect different processing of N2 when it is associated with a hemagglutinin to which the study population has not been previously exposed.


Dynamic mini-computer graphics analysis of long-term electrocardiographic tape recordings.

The full graphic capabilities of a minicomputer have been applied to rapid and versatile analysis of long-term electrocardiographic tape recordings. Interfaced to a standard Avionics tape analyzer, the system's multiple display options provide a powerful tool for arrhythmia detection in a reasonable amount of time. Detection accuracy of the system compares very favorably with previously published figures for computer EKG monitoring. Quantitation of arrhythmic beats is an integral feature of the tape scanning. A method for analog display of randomly selectable EKG complexes is also described.


On differences between the preovulatory luteinizing hormone surges of 4- and 5-day cyclic rats.

Preovulatory LH surges were studied in rats with ovarian cycles of 4 days (4d-rats) and 5 days (5d-rats). In 5d-rats the maximal peak height was about twice that observed in 4d-rats, whereas in 4d-rats peaks occurred about 1-5 h later than in 5d-rats and were much less consistently timed. From experiments in which LH releasing hormone (LH-RH) was infused into pentobarbitone-blocked pro-oestrous rats, it was concluded that (a) differences between the two types of preovulatory LH surges originate within the central nervous system, and (b) pro-oestrous LH-RH secretion may not be restricted to the period in which increased LH levels in blood were found, but may exceed this period for a considerable time.


Immunoreactive luteinizing hormone releasing factor in pituitary stalk blood from female rats: sex steroid modulation of response to electrical stimulation of preoptic area or median eminence.

The effects of sex steroid hormones on the responsiveness of the neural mechanism responsible for the secretion of LH-RF have been examined in the female rat. Responsiveness was determined at pro-oestrus by measuring the increments in immunoreactive LH-RF of pituitary stalk blood produced by electrical stimulation of the medial preoptic area or median eminence. Ovariectomy on the morning of dioestrus reduced the LH-RF response to preoptic stimulation while oestradiol benzoate (OB) or testosterone propionate (TP) administered immediately after ovariectomy significantly augmented the response. The facilitatory effect of TP was possibly due to its conversion to an aromatized derivative since 5alpha-dihydrotestosterone monobenzoate was ineffective. Progesterone did not facilitate preoptic responsiveness, and, when administered to animals ovariectomized at 12.00 h of pro-oestrus, reduced the LH-RF response at 18.00 h the same day. Stimulation of the median eminence produced a significantly greater increment in LH-RF than stimulation of the preoptic area. The facilitatory action of OB on the LH-RF response was less marked for median eminence compared with preoptic stimulation. The administration of ICI 46474 at 17.00 h of dioestrus did not reduce preoptic responsiveness on the morning of the next day, suggesting that this compound does not act as an 'antioestrogen' at the level of the preoptic area.


Secretion of luteinizing hormone caused by continuous infusions of luteinizing hormone releasing hormone in the long-term ovariectomized rat: effect of oestrogen pretreatment.

Continuous infusions of luteinizing hormone releasing hormone (LH-RH) into phenobarbitone-treated long-term ovariectomized rats, resulted in patterns of LH secretion which were determined by the blood LH-RH concentration. Infusions of 52 ng LH-RH/h caused steadily increasing ple maintained for the rest of the experiment (9h). A similar course of plasma LH concentration was observed as a result of infusions of 104 ng LH-RH/h, though in this case LH concentrations reached higher levels than those induced by infusion of 52 ng LH-RH/h. Higher rates of LH-RH infusion (208 and 416 ng/h), however, induced clear-cut LH peaks, which reached their maximal plasma values after 2-3 h of infusion and then declined again until, at the end of the experiment, they were only slightly higher than the LH levels induced by infusions of 52 ng LH-RH/h. A similar series of LH-RH infusions given to ovariectomized rats pretreated with oestradiol benzoate during 3 days (the rats were injected daily with 7 mug steroid), produced a highly augmented response of the pituitary gland, but all LH-RH concentrations infused induced rather sharp LH peaks, reaching their maximum after 2-3 h of infusion. After 5 h of infusion the descending parts of all these peaks appeared to converge. In both control and oestradiol benzoate-pretreated rats there appeared to be a linear relationship between the logarithm of the blood LH-RH concentration and the maximal plasma LH values on one hand, and the amount of LH secreted during the first 5 h of infusion on the other. Furthermore, it appeared that the longer the period of oestrogen action, the more the response of the pituitary gland to a certain dose of LH-RH was enhanced.


The interrelationship between progesterone and luteinizing hormone during the ovulation cycle of the hen (Gallus domesticus).

The existence of a circadian rhythm in the sensitivity of the hypothalamus of the laying hen to stimulation by progesterone was investigated by injecting 0.5 mg progesterone subcutaneously during the proposed period of maximum insensitivity. Following this treatment increases in plasma concentrations of both LH and progesterone were observed which were comparable to the spontaneous preovulatory rises in the plasma levels of the hormones. The ability of either progesterone or luteinizing hormone releasing hormone (LH-RH) to induce premature ovulation varied according to the stage of follicular development. Neither hormone was more than 28% effective when injected within 6.5 h of the previous ovulation, whereas both hormones were 100% effective approximately 27 h after the terminal ovulation of a clutch sequence. Failure to ovulate in response to LH-RH given 6.5 h after ovulation was associated with a lack of progesterone secretion. Both LH and progesterone were secreted when ovulation was induced by injections of either LH-RH or progesterone, and LH was secreted in response to progesterone given 6.5 h after ovulation. These results demonstrate that progesterone stimulates the secretion of LH and LH stimulates the secretion of progesterone. The precise physiological role of these two hormones, however, was not established.


A simplified procedure for preparing myogenic cells for culture.

A procedure involving mechanical agitation referred to as vortexing is compared to a trypsin procedure for obtaining myogenic cells for culture. The vortex procedure appears to be at least as useful as the trypsin procedure and has several advantages including speed, the elimination of chemical disruptive agent, elimination of collagen coating of culture dishes and earlier onset of fusion.


Antibodies reacting with cytoplasm of subthalamic and caudate nuclei neurons in chorea and acute rheumatic fever.

46% of sera from 30 children with rheumatic chorea showed IgG antibody reacting with neuronal cytoplasm of human caudate and subthalamic nuclei. The antibody was also detected in 14% of 50 children with active rheumatic carditis. 55 normal control sera, as well as 148 sera from a broad variety of other disease states showed a low prevalence (1.8-4.0%) of positive reactions. In rheumatic chorea the presence of anti-neuronal antibody appeared to correlate with severity and duration of clinical attacks. Antibody reacting with neuronal cytoplasm was completely removed by absorption with Group A streptococcal membranes or with isolated human neurons from caudate nucleus. Partial absorption of antibody was also recorded using Group A cell wall preparations but not with Group A carbohydrate. No absorption of positive reactions was seen with streptococcal Group D membranes or cell walls. In rheumatic chorea, anti-neuronal antibody appeared to represent cross-reaction with antigens shared by Group A streptococcal membranes.


Specific elimination of cytotoxic effector cells. I. Adsorptive behavior of effectors and their precursors and spleen cell monolayers.

Monolayers formed of normal mouse spleen cells attached to polystyrene coated with poly-L-lysine were tested for their ability to bind specifically antigen-reactive cells in normal or primed mouse spleen. 88 to greater than 98% of the activity of cytotoxic populations was removed by a single adsorption. However, normal spleen cells or spleen cells previously primed in vitro could not be depleted of their capacity to be sensitized, even when adsorption effectively removed all residual cytotoxic activity from the same previously primed population. In fact, exposure to an immunoadsorbent augmented the ultimate cytotoxicity generated in a nonspecific fashion. This augmentation was especially dramatic in the case of a previously primed population and may have reflected the removal of a nonspecific suppressor. If antigen-reactive precursors cannot be removed  efficiently by adsorption, other approaches to the generation of tolerant lymphoid populations, such as specific suppression of precursor differentiation must be sought.


The formation of a dissociable plasmid cointegrate from the Flac factor and the resident plasmid of Salmonella typhimurium LT2.

The Flac factor showed unstable maintenance in Salmonella typhimurium dnaC MP10LT2. The properties of a more stable lac+ derivate (SD-1) are described. SD-1 was ts and carried the fi+ property and the ability to transfer the lac+ character. It contained a large plasmid of molecular weight about 129 X 10(6) DALTONS. The properties of SD-1 and its derivatives suggested that the large plasmid was a cointegate of Flac and the MP10lt2 plasmid. Lac+ transfer was efficient from SD-1 to M799 MP10LT2 and one lac+ exconjugant contained the intact cointegrate. The cointegrate was not successfully transferred to strains lacking MP10LT2. It dissociated into apparently unaltered Flac and MP10LT2 plasmids, but the deletion of small parts of one or both plasmids during cointegrate formation could not be ruled out. Cointegrate dissociation was more marked in M799 than in SD-1 especially during growth in glucose-Casamino acids minimal medium. In the presence of R1drd19, the cointegrate (like the MP10LT2 plasmid) was stable maintained in the dnaC strain; maintenance of Flac was, however, unstable. It seems likely that replication of the cointegrate was controlled by the MP10LT2 plasmid constitutent.


The interaction of amphotericin B methyl ester with protoplasts of Candida albicans.

The interaction of amphotericin B methyl ester (AME) with protoplasts of Candida albicans was measured indirectly by following the incorporation of [U-14C]phenylalanine into the acid-insoluble material. The inhibitory effects of AME at the minimum inhibitory concentration were prevented by the addition of 85 mM-KCl and 45 mM-MgCl2, as shown by Liras & Lampen (1974) for Saccharomyces cerevisiae. In C. albicans, pretreatment of the yeast before anti-biotic addition was unnecessary. KCl and MgCl2 did not prevent AME from binding to the protoplast membrane. This interaction was reversed by incubating the protoplasts in the presence of the protecting salts.


Isolation of rough mutants of Klebsiella aerogenes and their synthesis of polysaccharides.

Two mutants which lacked both capsular and lipopolysaccharide O-antigen polysaccharides were isolated from Klebsiella aerogenes serotype 2 by phage selection; these were designated rough mutants. The polysaccharide fractions solubilized by partial acid hydrolysis of the lipopolysaccharide from both the wild type and mutants were chromatographed on Sephadex G-50. Analysis of the fractions obtained confirmed that the rough mutants lacked the galactan portion of the molecule, which is analogous to the Salmonella O-antigen polysaccharide. Membranes prepared from wild-type K. aerogenes, from a non-mucoid strain (lacking capsule only), and from one of the rough mutants were used in incubation mixtures to compare the biosynthesis of polysaccharides by these organisms. The incorporation of sugar nucleotides into both lipid intermediates and polymer was followed. Results show that the transferases were apparently present in all membranes, while the polymerases were absent in both the non-mucoid and rough mutants.


The regulation of diaminopimelate decarboxylase activity in Escherichia coli strain w.

Activity of diaminopimelate decarboxylase in Escherichia coli strain W, growing in an aerated fermenter, was only slightly (14%) repressed by 2 mM-lysine when approximately equimolar diaminopimelate was present in the medium. Lysine alone caused 78% repression. Diaminopimelate did not interfere with uptake of lysine by growing organisms. Organisms grown in medium containing diaminopimelate, without lysine, had a decarboxylase activity 24% higher than organisms from minimal medium. The extent of repression by pyridoxine (56% when added to minimal medium) was decreased (to 31%) when diaminopimelate was also present in the medium. A diaminopimelate-requiring mutant, with limited ability to take up diaminopimelate, formed almost three times less diaminopimelate decarboxylase than did a diaminopimelate-requiring second-stage mutant that had an increased rate of transport of this amino acid. The internal concentration of diaminopimelate thus probably regulates the activity of the decarboxylase by induction. Lysine might not directly repress the enzyme but might give an apparent repression by restricting the biosynthesis of diaminopimelate. This restriction is probably not caused only by inhibition or repression of aspartokinase. Lysine and threonine together, though not singly, almost completely inhibited aspartokinase in vitro but caused less apparent repression of diaminopimelate decarboxylase than did lysine alone. Lysine plus diaminopimelate strongly repressed the lysine-sensitive aspartokinase (85%) without much affecting diaminopimelate decarboxylase formation, and pyridoxine repressed the decarboxylase without affecting aspartokinase.


Derivation and properties of Proteus mirabilis systems for high frequency transduction of streptomycin--sulphonamide and streptomycin-sulphonamide--kanamycin resistances.

Properties of two transducing systems with phages capable of high frequency transduction (HFT) of streptomycin and sulphonamide resistance markers of the V group plasmid R905, and of these markers plus the kanamycin resistance marker derived from a previously described HFT phage 5006MHFTak, are described. Transducing particles of the former phage, named 5006MHFTsus, were detected using the replica-plate technique in an ultraviolet-induced lysate of Proteus mirabilis strain PM5006 transduced to streptomycin and sulphonamide resistance by phage 5006M grown on PM5006 carrying R905. Phage 5006MHFTsusk was also detected by the replica-plate technique in ultraviolet-induced lysates of of phage 5006MHFTsus transductants retransduced to ampicillin and kanamycin resistance by phage 5006MHFTak. Both phages were serologically identical to the parent phage 5006M. Ultraviolet-induced lysates transduced their markers to PM5006 at frequencies of about 5 X 10(-2)/plaque-forming unit adsorbed for both the phages. With phage 5006MHFTsusk, this frequency was increased about 10-fold by simultaneous infection of recipients with homologous non-transducing phage, while phage 5006MHFTsus transductions only underwent a twofold increase. Transductants took about 60 min to express complete resistance to 50 mug streptomycin/ml, and resistance to 1600 mug sulphadiazine/ml was complete within 120 min after phage adsorption. Phage 5006MHFTsusk was slightly more resistant to ultraviolet inaction of its transducing potential and reasons are given for the belief that transductants of both phages are heterogenote-like. Both phage lysates were also capable of generalized transduction and, like previously described HFT phages, lysates transduced the leucine marker at increased frequencies. Using previously described extra- and intra-species phages hosts, it was found that the phages could transduce in single infection and were defective in the lysogenic conversion function as well as in a maturation step. Possible modes of formation of the HFT particles are discussed9


The detection of viruses by enzyme-linked immunosorbent assay (ELISA).

The use of enzyme-linked antibodies for the detection of two morphologically different plant viruses is described. The technique is extremely sensitive, enabling assay of the viruses at concentrations as low as 10 to 100 ng/ml both in purified preparations and in crude plant extracts.


A provisional classification of cytoplasmic polyhedrosis viruses based on the sizes of the RNA genome segments.

The RNA genome segments of thirty-three isolates of cytoplasmic polyhedrosis viruses (CPVs) were examined by polyacrylamide gel electrophoresis. Major differences were observed in the gel profiles of the RNA segments from many of the viruses; differences which were reinforced by polyacrylamide gel electrophoresis of the virus structural proteins. As a result of these studies, a provisional classification scheme for CPVs is proposed, where viruses with similar RNA gel profiles are included within the same 'type', while isolates differing in the molecular weights of most, or all of the RNA segments are assigned to different types. Using this system, eleven distinct CPV types were recognized. All eleven CPV types, like reoviruses, probably contain ten segments of RNA with a toatl mol. wt. of approx. 15 X 10(6).


Impact of the seclusion room experience.

The seclusion room is a repository of intense feeling and strongly held opinion for members of psychiatric inpatient units. Patients, nurses, and doctors often find themselves in intrapsychic and/or interpersonal conflict over its use and misuse. Perhaps because of general discomfort, relatively little is known about what a patient actually experiences while secluded. In this report, we utilized an unexpected source of information on the meaning of the seclusion room experience for our patients: their art productions. The observations are based upon our therapeutic and research experience with acutely schizophrenic patients hospitalized on an NIMH clinical research unit located in NIH's Clinical Center. On this unit, pharmacotherapy was not used during investigation periods and, in keeping with the unit's treatment philosophy, was used sparingly or not at all during noninvestigative periods. As a result, the seclusion room was used frequently for severe management problems. Systematic collection of art productions was a routine part of the research protocol. Patients attended three individual art therapy sessions: during drug-free periods 2 to 3 weeks after admission, 2 to 3 weeks before discharge, and at follow-up 1 year after admission. The patient was asked to use pastels to draw the following pictures: a free picture (patient's choice), a self-portrait, a picture of his/her psychiatric illness, a picture of any hallucination experienced, and a picture of any delusion experienced. After completing each picture, the patient was encouraged to discuss it. Sixty-two patients were evaluated with this methodology. Particulary noteworthy is the fact that in no instance was a patient requested to draw a picture about a seclusion room experience. Nevertheless, over one third of the patients did so, underscoring the prominence of the experience for them. Furthermore, these pictures did not emerge from a large array of patient art, but from only threee art sessions per patient. The nature of the pictures fell into the following patterns: a) pleasurable hallucinations occurring while in seclusion; b) frightening delusions connected with the experience of seclusion; c) strong nondelusional feelings about being in seclusion (often the picture of the psychiatric illness was a representation of the seclusion room experience); d) special focus on the staff member in attendance outside the seclusion room door. The implications of these graphic expressions are discussed, with particular emphasis on the impact of the seclusion room experience for the patient.


Histochemical fluorescence studies of brain monoamines in goldthioglucose-treated rabbits.

Fluorescence histochemical experiment of brain monoamines and chemical analysis of brain 5-hydroxytryptamine (5-HT) in goldthioglucose (GTG)-treated rabbits were performed. The fluorescence of brain catecholamines (CA) and 5-HT were strengthened in intensity until first week after treatment and reduced from second week. Body weight in GTG-treated rabbits showed decreasing tendency in the period when monoamine fluorescence was strengthened and increased when monoamine fluorescence was lowered in intensity. Content of brain 5-HT second day after treatment showed an increasing tendency in the cortex. In comparison with EEG findings by Matsumura, it is speculated that there is correspondence between slow wave in EEG and increased fluorescence of brain monoamines and between spiky and decreased fluorescence.


Serotonin, noradrenaline, dopamine metabolites in transcendental meditation-technique.

The highly significant increase of 5-HIAA (5-hydroxyindole-3-acetic acid) in Transcendental Meditation technique suggests systemic serotonin as "rest and fulfillment hormone" of deactivation-relaxation. Furthermore 5-HT (5-hydroxytryptamine, serotonin) is considered to be the EC-cell (enterochromaffine-cell) hormone requested by Fujita and Kobayashi and its role for EEG synchronisation via area postrema chemoreceptor as anti arousal agent is being discussed. The significant decrease of the catecholamine metabolite VMA (vanillic-mandelic acid) in meditators, that is associated with a reciprocal increase of 5-HIAA supports as a feedback necessity the "rest and fulfillment response" versus "fight and flight". As the adreno medullary tissue serves for hormonal reinforcement of orthosympathetic activity, the Enterochromaffine Cell System (having taken the form of distinct organs in some species as octopus and discoglossus) is suggested to serve via serotonin for humoral reinforcement of parasympathetic activity in deep relaxation.


Human brain in tissue culture. Part. 5. Identification of glial cells by immunofluorescence.

Glial fibrillary acidic (GFA) protein was demonstrated by immunofluorescence in both primary and long-term cultures of adult human brain cells explanted from normal, neoplastic and non-neoplastic CNS diseases, and in mouse brain cells subcultivated in vitro. GFA protein was present in the cytoplasm of at least 4 distinct cell types and persisted throughout the finite lifetime of brain cell cultures.


Progressive muscular dystrophy. Functional improvement after a renal allograft.

From his first years a child showed signs of a primary and rapidly developing muscular dystrophy. The diagnosis was established by an increased serum CK level and by electromyography and muscle biopsies. Afterwards this child developed a severe renal deficiency which needed binephrectomy and the graft of a normal kidney. During the few months just after the graft, the disability increased and the patient could not stand upright by himself. Later on, he gradually became able to walk on his own and without bracing. He could climb stairs and stand up from the floor. The CK activity returned to normal. At present, 4 years after the graft (the patient is 16 years), the improvement of his functional abilities is constant, although the CK activity has increased again. In this article we give evidence that this patient suffers from a primary muscular dystrophy. We discuss the type of dystrophy concerned. We believe that it is the graft of a normal kidney which was responsible for the improvement observed, and not the physiotherapy or the drugs administered after the graft.


Two separate membrane-bound antigens on human glioma cells in tissue culture detected with sera from glioma patients by immunofluorescence.

Sera from patients with malignant and benign gliomas, as well as sera from healthy donors, were tested by indirect immunofluorescence to detect antibodies against antigens on the membrane of glioblastoma, astrocytoma, reactive perimetastatic glia, normal glia and fibroblasts in tissue culture. Sera from glioblastoma patients reacted with glioblastoma, astrocytoma and reactive glial cells; they were negative on normal glia and on fibroblasts, whereas sera from astrocytoma patients were unreactive. Sera from control patients were positive in 7 out of 15 cases, although some differences were noted in the pattern of reaction. Absorption with astrocytoma powder, with glioblastoma and reactive glial cells indicated that all the positive cell lines expressed an astrocytoma-associated antigen "A", while only glioblastoma lines and reactive glial line shared a supplementary antigen "G". Neither of these 2 antigens seemed to  be present in significant amount in normal brain, since the positive reactions could not be abolished by absorption with normal brain powder. The relationship between these 2 antigens and the process of increasing malignancy in gliomas is briefly discussed.


Double-blind evaluation of intradiscal chymopapain for herniated lumbar discs. Early results.

The authors report 66 patients with signs, symptoms, and a myelographic abnormality of herniated lumbar disc, who were not responsive to conservative treatment. The discs were injected at random with either chymopapain or a placebo. Neither patient nor surgeon knew which agent was used until after the results had been tabulated. Unless early laminectomy was necessary for intractable pain, all patients were followed for 2 months or more. There was no statistically significant difference in incidence or quality of improvement between the two groups: chymopapain was successful in 58% while placebo was successful in 49% (p = 0.15). Early results from this study indicate that most, if not all, of the putative effectiveness of chemonucleolysis probably derives from a placebo effect.


Pyruvic acid as an etching agent.

Phosphoric acid at different concentrations has been extensively used as an etching agent to improve bonding of dental materials to enamel surfaces. Recently attention has been drawn to the possible use of polyfunctional organic acids as conditioning agents. The object of this investigation was to determine the optimal concentration of pyruvic acid as an etching agent. A commercial composite resin with an intermediary bonding system supplied with 37% H3PO4 as an etching agent was used as the control system. In addition, a comparative study was carried out to evaluate 37% H3PO4, 20% lactic acid and the optimal concentration of pyruvic acid as conditioning solutions. Etching enamel surfaces with 10% pyruvic acid resulted in the optimal tensile bond strength of the resin to etched enamel surfaces. The use of 10% pyruvic acid did not adversely affect the bond strength of the resin system when compared to enamel surfaces etched with 37% H3PO4 for the same time period. Significantly lower tensile bond strengths were recorded on enamel surfaces etched with 20% lactic acid. The rate and depth of etching obtained with 37% H3PO4 can be considerably reduced by using 10% pyruvic acid as the conditioning agent.


The use of root abutments in the support of complete dentures.

A clinical study of the use of root abutments as an aid to the support of complete dentures is presented. This technique offers a realistic alternative for patients who are reluctant to face the loss of their remaining natural teeth and the wearing of complete dentures. The abutments enhance the support and stability of the dentures and appear to slow the rate of alveolar resorption. The clinical procedures are straightforward and can be readily applied in general dental practice.


The long term bonding of a polymeric fissure sealant to stannous fluoride treated enamel.

A report is presented of extended studies of tensile bond strength of Nuva Seal to fluoride-treated enamel 1 week, 3 months and 9 months after application. The differences in strength were not statistically significant. The use of stannous fluoride as the topical agent did not lead to any marked evidence of enamel staining.


Marginal leakage with different composite restorative materials in vitro. Effect of cavity design.

In this preliminary study the degree of marginal leakage was assessed for different cavity designs using both ultra violet-curing and self-curing composite restorative materials and sealants. Butt joint restorations placed in etched and sealant primed cavities failed to prevent leakage. Both saucer-shaped and funnel-shaped cavities and cavities with rounded margins were able to prevent leakage when the restorations were bonded to etched and sealant primed peripheral enamel. Further, less than 1 mm of gingival enamel available for bonding seemed to be sufficient in most instances to prevent leakage.


Stress distribution within circumferential clasp arms.

An analysis of stress distributions within circumferential clasp arms with various tapers, was undertaken in an effort to (1) determine the area of maximum stress concentration in both tapered and non-tapered clasps, and (2) to compare this point of maximum stress concentration with the area of frequent clasp breakage. The non-tapered clasp showed better distribution of stresses than the tapered clasps. The less favourable stress concentrations could result in eventual failure of the clasp when coupled with other factors such as porosities. The maximum shear stresses in the non-tapered clasp also were lower than those in the tapered clasps. As the taper of the clasp became more accentuated, the magnitude of the stresses increased and shifted towards the tip of the clasp. The maximum tensile stress calculated in a replica of a chromium-cobalt-nickel clasp was in the order of 34 MN/m2 which is well below the ultimate tensile strength of the alloy. This observation leads to the proposal that failure of clasps is a function not only of design but also of other variables, such as porosities, surface irregularities, and fatigue.


The linear model: a statistical tool applied to psychophysical research in dental prosthetics.

The construction of a linear model is described, and its function in analysing variations in the perception of comfortable mandibular occlusal positions is explained. In principle, the model combines analyses of variance and regression in a number of simple computer operations. Data from a clinical study were used to demonstrate the analytical capacity of a specific model, designed to estimate the effect of factors, which were supposed to influence the perception of comfortable mandibular positions.


The cross sectional area of diaphragmatic muscle fibres in emphysema, measured by an automated image analysis system.

The cross-sectional area of diaphragmatic muscle fibres was measured using a Quantimet 720 image analysis system in 18 patients with emphysema and six control non-emphysematous patients. The technique proved to be an accurate method of measuring muscle fibre area and much more rapid than the previously described methods. The mean cross-sectional area of the muscle fibres in the emphysematous group was 1069-5 mum2 and this was significantly greater than the mean of the control group which was 851-0 mum2. In the emphysematous group nine patients who died from chronic airways obstruction had a larger mean muscle fibre area than the nine patients with non-fatal respiratory disease. The emphysematous patients showed a marked increase in the number of very large muscle fibres (2000-2200 mum2) in the diaphrahm and also an increased variation in size from fibre to fibre. The increase in muscle fibre size showed a positive correlation with ventricular weight but not with the amount of emphysema in the lungs. It would appear that although the excursion of the diaphragm is reduced in emphysema the muscle fibres do not atrophy but in fact undergo work hypertrophy. This is presumably due to the horizontal shortening of the muscle fibres, when the diaphragm is working at a poor mechanical advantage, because it cannot descend normally in emphysematous patients.


An ultrastructural analysis of lympho-reticular cell interactions in primary cultures of human non-lymphoid neoplasms and lymphomas.

The morphology and interactions of lymphoreticular cells in cultures of human tumour tissue was studied by transmission and surface scanning electron microscopy. Macrophages are very common in non-lymphoid neoplasms and vary considerably in shape and surface morphology, with features of mature stimulated cells. Lymphocytes adhere to macrophages more often  than to tumour cells. Close contact between macrophages and tumour cells also occurs, but there is no evidence that the infiltrating macrophages or lymphocytes have an overt cytotoxic effect under these cultural conditions. A variety of interactions are seen in cultures of Hodgkin's lymphoma, lymphosarcoma and reticulum cell sarcoma. The only cultural characteristics that may be specific for lymphoma tissue are large intravacuolar collections of lymphocytes within macrophages or giant cells and the rare close spatial relationship between lymphocytes and degenerate macrophages, the latter particularly in Hodgkin's lymphoma. These observations demonstrate the disturbed cellular interrelationships that exist in lymphoma tissue.


Canine leptospirosis: an immunopathological study of interstitial nephritis due to Leptospira canicola.

In an attempt to define the pathogenetic mechanisms involved in acute interstitial nephritis due to Leptospira canicola the kidneys of 14 dogs were subjected to histological immunofluorescence and elution studies. Leptospiral antigen was found in three sites within the kidney; as discrete organisms in the proximal tubules, as granular deposits in the cytoplasm of macrophages and in large extracellular clumps in the interstitium. Deposits of IgG were also detected in the latter site and in plasma cells found in the surrounding cellular infiltrate. Anti-leptospiral antibody, mainly of the IgG class, was detected in renal eluates using both agglutination-lysis and indirect immunofluorescence. From these findings it was considered that the cellular infiltrates found in the kidneys of dogs suffering from acute leptospiral nephritis have two main functions; firstly, the local production of anti-leptospiral antibody and, secondly, phagocytosis.


Pathology of the cervical spine in rheumatoid arthritis: a controlled study of 44 spines.

Cervical spines (with occiputs) of 44 patients with rheumatoid arthritis (RA) were compared with 44 control spines from patients without RA, matched for sex and age. There were six severe and seven slight atlanto-axial dislocations (both horizontal and vertical, two of which had been treated surgically) in the RA group and none in the control group. Ankylosis, synchondrosis, syndesmosis, bone erosions, and redness of synovial tissue in the atlanto-axial, atlanto-occipital and cervical intervertebral joints were more frequent in the RA group than in the control spines. The lesions permitting the best discrimination between the RA and control groups were used to calculate an overall score for the whole cervical spine. Sixteen of the 44 RA patients scored higher than the highest control value; only nine scored lower than the median control score. A higher score than the average value found for the RA spines was obtained by the male patients, the patients with seropositivity or subcutaneous nodules, the patients treated with corticosteroids, the patients who died in the Department of Rheumatology, and those whose death was related to the RA itself or to the treatment given.


Skin lesions, angioedema, eosinophilia, and hypocomplementemia.

A six-year-old girl with recurrent urticaria and angioedema, vasculitis, and probable renal disease exhibited marked blood eosinophilia, increased levels of serum IgE, circulating Clq precipitins, and hypocomplementemia with evidence of activation of complement by the classic pathway. Biopsies of skin and muscle revealed heavy infiltrations of the vessel walls with eosinophils. Immunofluorescence studies revealed deposition of IgM, IgE, and C3 in the vessel walls. Exacerbations of the disease were associated with an increase in the eosinophil count and a decrease in the serum levels of C4 and C3. Remission was achieved with corticosteroid therapy. This patient has many features in common with the syndrome of skin lesions, angioedema, and hypocomplementemia recently described in adults.


Parathyroid function in uremic children during periods of renal insufficiency, hemodialysis, and transplantation.

Function of the parathyroid gland was evaluated in children with renal insufficiency prior to and after imitation of hemodialysis, and again following renal transplantation. Serum levels of immunoreactive parathyroid hormone responded appropriately to increases or decreases of serum calcium concentrations in the three groups. Functional and histologic studies in the children with renal insufficiency demonstrated the cause of their elevated circulating levels of iPTH to be diffuse parathyroid hyperplasia. During hemodialysis, the serum concentration of calcium rose and that of iPTH decreased, when the calcium gradient between the dialysate and the blood favored movement of calcium into the body. During treatment with prednisolone (20 mg/kg intravenously) for reversal of renal transplant rejection, the serum concentration of calcium decreased and that of iPTH increased. These observations suggest that autonomy of the parathyroid gland rarely occurs in children with renal insufficiency, and that hemodialysis using a dialysate with a high concentration of calcium might assist in retarding the progression of renal osteodystrophy. Furthermore, if hyperparathyroidism contributes in part to growth failure in children with chronic renal disease, steroid-induced changes in cirulating iPTH following renal transplantation may inhibit growth.


A prolonged nursery epidemic associated with a newly recognized type of group A streptococcus.

During a six-month period 69 infants in a newborn nursery were colonized with group A streptococci. Fifty-one had omphalitis, two infected circumcision wounds, and one each had meningitis, primary peritonitis, and conjunctivitis. Thirteen infants were asymptomatically colonized. Control of the epidemic was difficult. Benzathine penicillin prophylaxis to all infants suppressed active infection but did not eradicate asymptomatic colonization of the umbilical cord. Triple dye treatment of the umbilical cord plus benzathine penicillin prophylaxis eradicated the infection from the nursery. The epidemic streptococcus was a newly recognized ""skin strain,'' provisional type strain 5656-S, not previously known to cause epidemic disease or serious systemic infections.


Bactericidal capacity of monocytes of newborn infants.

The peripheral leukocytes of newborn infants and of adult volunteers were studied after separation of polymorphonuclear and mononuclear cells. Monocytes were identified and quantitated with the aid of histochemical staining. The in vitro killing capacity of PMN and of monocytes was assayed against Staphylococcus aureus and Escherichia coli. The monocytes of both infants and adults were significantly less active than were their PMN, but the bactericidal capacity did not differ appreciably between newborn and adult cells of either type.


Beclomethasone dipropionate in long-term treatment of asthma in children.

Beclomethasone dipropionate was found to be effective in reducing symptoms of asthma in children. There was no measurable influence on pulmonary function. An 18-month follow-up did not show untoward side effects on adrenal function, growth, serum electrolytes, and hepatic and renal functions with a dose of 100 mug three times daily. The treatment predisposes to the colonization with Candida albicans in the oropharynx.


Theophylline pharmacokinetics in premature infants with apnea.

The pharmacokinetics of theophylline were examined in eight low-birth-weight infants (gestation: 26-32 weeks: birth-weight: 887-1,480 gm), who received the drug for treatment of primary apnea. The drug was assayed by high pressure liquid chromatography. The final dosage was 1 to 3 mg/kg/6 hour at 25 to 37 days of age. At the time, theophylline had a prolonged half-life ranging from 13 to 29 hours, a relatively large volume of distribution of 0.65 to 2.86 1/kg, and a small body clearance of 23 to 68 ml/hr/kg. The extremely slow and variable elimination of theophylline must be considered in treatment of apneic infants. The initial dosage regimen suggested is a loading dose of 6 mg/kg and a maintenance dose of 2 mg/kg/ 12 hours, with adjustments made based on monitoring of the serum concentration and on an increased biotransformation capability as maturation occurs.


Cultivation of the erythrocytic stages of Plasmodium berghei in primary bone marrow cells.

Cultures of primary bone marrow cells, obtained from the tibiae and femora of hamsters (HBM), mice (MBM), or rats (RBM) were inoculated with red cells infected with Plasmodium berghei, P. vinckei vinckei, or P. knowlesi. Merozoites, rings, trophozoites, schizonts and a few gametocytes were seen in HBM and MBM cells inoculated with P. berghe-infected red cells. At 1 to 2 or 3 days after inoculation in HBM and MBM, the number of intracellular asexual stages decreased slightly or remained the same, whereas at 3 to 7 or 8 days a 4 to 7-fold increase occurred. Parasites then decreased in number from days 8 to 11 and no parasites were seen on day 12. Intracellular parasites were most numerous at 7 and 8 days in MBM and HBM cultures, respectively. Mice injected with supernatant or cells from control cultures (without cultured cells) or primary cultures inoculated 1 and 2 days earlier with P. berghei- or P. vinckei vinckei-infected red cells always became infected. Mice injected with material from 3-day-old control and experimental cultures usually became infected, and those injected with 4- to 12-day-old cultures never became infected.


Schizont-infected cell enrichment in rodent malaria.

Mouse erythrocytes parasitized with Plasmodium berghei or Plasmodium yoelii were separated by ultracentrifugation using preformed isodensity gradients of the discontinuous type. Three fractions were obtained following centrifugation, the upper of which contained greater than 90% of all schizont-infected cells added to the gradient. The gradient material, Stractan II, is an arabinogalactan polysaccharide and appears to yield results similar to those available using gradients of bovine serum albumin. Cells are not altered morphologically or physiologically (as assessed by infectivity) by the treatment.


Stimulation of resistance in mice to sporozoite-induced Plasmodium berghei malaria by injections of avian exoerythrocytic forms.

Mice received a series of injections of formalin-killed merozoites (FKM) of exoerythrocytic stages of Plasmodium fallax prior to challenge with sporozoites of P. berghei. In one study 4 of 16 FKM-immunized mice never exhibited parasitized erythrocytes after 2 challenges of 10(4) P. berghei sporozoites each, while all control animals died with high parasitemias. FKM-immunized mice were as susceptible as control mice to infections initiated with parasitized erythrocytes. In a second study, 14 of 16 mice immunized via the intravenous (i.v.) or combined intramuscular (i.m.) and i.v. routes were immune to an initial challenge with 10(4) sporozoites, but were susceptible to a second challenge. Three injections of FKM via the i.m. or intraperitoneal routes did not elicit a protective response against sporozoite challenge. Sera harvested from FKM-immunized and control mice prior to challenge produced no visible CSP reaction with P. berghei sporozoites, nor was infectivity of sporozoites altered after incubation in sera, showing that SNA was absent. In additional experiments results were less encouraging. An attempt to repeat the result of the second experiment failed. Each of 5 mice which received the same number of FKM by a similar schedule became infected after sporozoite challenge. In an additional study the immunization schedule was increased from 3 to 7 injections of FKM and 40% of FKM-immunized mice resisted challenge. However, mice which had received FKM prior to sporozoite challenge consistently displayed an increased prepatent period compared with control animals. A department from methods of the more successful studies was necessitated in these later studies in which FKM were harvested from cell cultures maintained for longer periods of time.


A fluidic-controlled, miniature respirator with a new positive airway pressure device.

A simple and miniature respirator was developed providing controlled ventilation and application of a positive airway pressure. The positive airway pressure is achieved by an airflow through a canula into the airways. During expiration the direction of this insufflated air-flow is changed and the dynamic pressure necessary for it manifests itself as a positive airway pressure. Mechanical ventilation functions according to the principle of the Ayre-T-Piece: flow direction and, therefore ventilation, is controlled by occlusion of the expiratory limb. Occlusion is brought about by inflating a balloon. The inflation of the balloon is controlled by fluidic-circuits. They allow setting of frequency, duration of inspiration and pressure limit. As the above mentioned system for creating a positive airway pressure is integrated, mechanical ventilation with PEEP is achieved. Tests on a lung model were performed to establish the variables which influence the amount of positive pressure produced by an air-flow through a canula into a tube. Results indicate that the positive pressure obtained is inversely correlated to the diameter of tube and canula and varies with the angle of inflow (Tab. I, II, Fig. 4). The pressure-rise-velocity depicted in Fig. 5 suggests that sighing is possible in an open system. On an anencephalic newborn pressure-flow-ratios were established (Fig. 6). Pressure-time curves during spontaneous breathing, CPAP assisted breathing and sighing combined with CPAP were recorded in a 3 month old baby (Fig. 7, 8, 9). The discussion states the technical performance of the respirator (frequency 100/min-1/3 min., tidal volume 5-100 ml, controlled ventilation with pressure limitation, application of PEEP) and additional advantages (no apparatus deadspace, disposable i.e. sterile air supply-system, the miniature dimensions 10 x 10 x 5 cm, versatility and simple therefore technically reliable construction).


The effect of folic acid on gingival health.

On days 0 and 30 of a double blind study, two groups of 15 subjects each were evaluated using a plaque index, a gingival index, a gingival exudate flow and fasting plasma folic acid levels. Group I received 2 mg of folic acid twice daily for 30 days while Group II received a placebo. Results of the study seem to indicate that folic acid supplemented to the diet may increase the resistance of the gingiva to local irritants and thus lead to a reduction in inflammation.


Microbial contamination of dental units and ultrasonic scalers.

Microbial contamination of the water system in 12 dental units and nine ultrasonic scalers was investigated. Water samples from ultrasonic scalers, high-speed handpieces and water syringe lines showed microbial concentrations of up to 2.6 million, 3.3 million and 190,000 colony forming units/ml respectively. Flushing the lines for 2 minutes reduced the microbial levels, but complete elimination of all bacteria was not achieved. The infectious potential of contaminated water, to the dentists and patients, particularly the compromised host is discussed.


Synthesis and properties of mesoionic pyrimido[1,2-b-a1pyridazine-2,4-diones and mesoionic pyridazino[2,3-a-a1-s-trizine-2,4-diones: mesoionic analogs structurally related to fervenulin.

Derivatives of two new and unusual classes of heterocycles, possessing structural similarities to the broad spectrum antibiotic fervenulin, were synthesized and examined for in vitro antimicrobial activity. Only three of 17 mesoionic pyrimido[1,2-b]pyridazine-2,4-diones exhibited evidence of antimicrobial activity while seven of eight mesoionic pyridazino[2,3-a]-s-triazine-2,4-diones were active against one or more microorganisms. Susceptibility toward attack by nucleophiles of both mesoionic pyridazino[2,3-a]-s-triazine-2,4-diones and fervenulin was observed.