Polymorphonuclear leukocyte-mediated, antibody-dependent, cellular cytotoxicity against tumor cells: dependence on oxygen and the respiratory burst.

Experiments were done to determine 1) whether the respiratory burst of superoxide anion (O2-) production in polymorphonuclear leukocytes (PMN) is triggered during antibody-dependent killing of tumor cells and 2) whether O2- production is essential for cytotoxicity. Three parameters of the respiratory burst (1-14C-glucose oxidation, oxygen consumption, and O2- release) were increased 2.5- to 7.3-fold during killing of antibody-primed tumor cells by human PMN. Added catalase and superoxide dismutase did not inhibit lysis, possibly because these enzymes were unable to diffuse into the inter-plasma-membrane space between killer and target cells. Evidence for an O2- requirement for cytotoxicity was the fact that concentrations of amobarbital or phenylbutazone sufficient to inhibit the cyanide-insensitive respiration of PMN also inhibited cytotoxicity. Also, hypoxic conditions inhibited cytotoxicity from 29 to 73%. The requirement for oxygen was most likely related to O2- generation and not mitochondrial respiration since cyanide and azide, which inhibit mitochondrial respiration, increased cytotoxicity.     

An analysis of canine size and jaw shape in some Old and New World non-human primates

An analysis of the relationship between the height of canine teeth, the length of the jaw and the height of the jaw joint above the occlusal plane was undertaken in catarrhine primates and some cebids. An inverse relationship was found in males between the angle
the jaw must be opened to clear the canine teeth and the height of the jaw joint above the occlusal plane, divided by the length of the lower jaw. A theoretical model is presented which can account for this phenomenon and which presumes selection pressure for alignment of the canine teeth when in use. In females, the angle the jaw must be opened to clear
the canine teeth was in most cases very small though in certain species elongated canines
were found.     

Innervation of the cultured fetal rat pancreas

Summary The fetal rat pancreas, explanted at 18 days of gestation and cultured up to ten days, contains numerous acetylcholinesterase-positive neurons. These nerves usually appear in small ganglia although single nerve cells are encountered. The axons of these intrapancreatic nerves appear to terminate only in the islet tissue and not on any exocrine components of the expiant. It is concluded that the fetal rat pancreas contains an islet-specific group of cholinergic neurons.We gratefully acknowledge the skilled technical assistance of Dan Whitehead and the secretarial assistance of Mary Pat Brady     

Alkaloids of Papaver bracteatum: 14-β-hydroxycodeinone, 14-β-hydroxycodeine and N-methylcorydaldine

Three new alkaloids have been identified from Papaver bracteatum, 14-β-hydroxycodeinone, 14-β-hydroxycodeine and N-methylcorydaldine. The presence of alpinigenine was also confirmed.     

Non-B hepatitis in Melbourne: a serological study of hepatitis A virus infection.

A study was performed to establish the value of immune adherence haemagglutination tests for antibody to hepatitis A virus in the diagnosis of non-B hepatitis. Infection with hepatitis A virus was confirmed in 14 out of 16 patients from six families and seven out of nine patients in whom the source of infection was unknown. One additional patient, who had had two episodes of jaundice, was shown to have had an attack of hepatitis A followed by an attack of hepatitis B. In patients with acute hepatitis A antibody detectable by immune adherence haemagglutination becomes detectable three or four weeks after the onset of symptoms and reaches peak levels about five weeks later.     

Induction of programmed cell death (apoptosis) in mature lymphocytes

The apoptosis of human peripheral blood lymphocytes was analyzed by the breakdown of DNA into oligonucleosome-sized fragments. The mature lymphocytes were rendered sensitive to apoptosis by either the omission of fetal bovine serum in the culture medium or the addition of polymyxin B. In the first case it was counteracted by phorbol myristate acetate. The possible involvement of protein kinase C in cell survival is pointed out.     

Stable inheritance of shuttle vectors based on plasmid pIM13 in a mutant strain of Clostridium acetobutylicum.

New shuttle vectors for Clostridium acetobutylicum were constructed, using as replicons the Gram-positive plasmid pIM13, and derivatives of the Gram-negative plasmid pBR322, including pUC19. These vectors transformed C. acetobutylicum at a high frequency (up to 10(6) transformants per microgram DNA) by PEG-mediated protoplast transformation. A mutant host strain, NI-4082, was isolated on the basis of its ability to maintain plasmid pIM13 stably in the absence of selection pressure. The shuttle vectors showed no segregational or structural instability in this mutant strain. Moreover, the results suggested a relationship between segregational instability and the multimerization of pIM13 in C. acetobutylicum. The host/vector system described possessed all the properties required for efficient gene cloning in this species.     

Cytokine production after intravenous or peritoneal gram-negative bacterial challenge in mice. Comparative protective efficacy of antibodies to tumor necrosis factor-alpha and to lipopolysaccharide.

The production of TNF-alpha, IL-1, and IL-6 was measured in mice after bolus i.v. Escherichia coli O111 LPS injections and during bacteremia induced either by bolus i.v. or by i.p. challenges of live E. coli O111. High but transient TNF-alpha peaks were observed after bolus i.v. LPS or bacterial challenges. In contrast, the levels during lethal peritonitis increased progressively to values 50- to 100-fold lower than the peak values observed after i.v. injections, and remained sustained until death. Whereas after i.v. challenge with 1000 LD50 of LPS, anti-TNF-alpha antibody fully protected mice from death and reduced serum IL-1 and IL-6 levels, anti-TNF-alpha antibody did not improve the survival of mice nor reduced serum IL-1 and IL-6 levels after i.p. bacterial challenge. In contrast to anti-TNF-alpha antibodies, anti-LPS antibodies were protective in the peritonitis model. Protection was accompanied by a striking reduction of bacterial numbers and of TNF-alpha, IL-1, and IL-6 levels in the serum, but the levels of these cytokines were only marginally affected in the peritoneal lavage fluid. This latter observation demonstrates that the local peritoneal cytokines did not diffuse readily into the circulation, thus suggesting that at least part of the circulating cytokines are produced systemically. In conclusion, the striking differences between cytokine profiles as well as the divergent efficacy of anti-TNF-alpha antibody after i.v. bolus and after i.p. challenges suggest that TNF-alpha may not be as important in the pathogenesis of lethal peritonitis than after lethal acute bacteremia.     

Auxin-induced H+-pump stimulation does not depend on the presence of epidermal cells in corn coleoptiles

Cell-wall acidification and electrical reactions (depolarization and hyperpolarization) are typical auxin responses in maize (Zea mays L.) coleoptiles. In an attempt to test the role of the outer epidermis in these responses, they have been measured and compared in intact and peeled coleoptile fragments. To exclude interactions between parenchymal and epidermal cells, the coleoptile pieces were completely stripped of their outer epidermis. This preparation was monitored by means of a scanning electron microscope. When externally applied indole-3-acetic acid was tested, we found that neither cell-wall acidification nor the electrical membrane responses depended on the presence of intact epidermal cells.Abbreviations IAA Indole-3-acetic acid - MES 2-[N morpholino-ethane-sulfonic acid - TRIS 2-Amino-2-hydroxymethyl-1,3-propanediol We thank Kuki Kaethner for her excellent technical assistance. This work was supported by the Hessische Graduiertenförderung and the Deutsche Forschungsgemeinschaft.     

Relationships between take-all,soil conduciveness to the disease,populations of fluorescent pseudomonads and nitrogen fertilizers

Take-all of wheat, caused by Gaeumannomyces graminis var tritici (Ggt), is reduced by ammoniacal fertilizers as compared to nitrate sources. This influence of nitrogen on the disease is only observed on nodal roots at flowering. But soil conduciveness to take-all, as measured in a soil bioassay, is modified earlier. Forty days after nitrogen application at early tillering, the NH₄-treated soil became less conducive than the NO₃-treated one. When nitrogen applications are done at sowing and at tillering, differences in disease propagation between the two soils are enhanced. Results from four years of experimentation show that when the level of natural soil inoculum is high, disease severity is reduced by ammonium, showing an effect on the parasitic phase of Ggt. At a low level of natural inoculum the effect of the source of nitrogen is mainly observed on the percent of infected plants, indicating that the saprophytic and preparasitic phases are affected. Rhizospheric bacterial populations increase from sowing to tillering, but differences on take-all conduciveness after tillering are not correlated with differences in the amounts of aerobic bacteria or fluorescent pseudomonads isolated from soils treated with different sources of nitrogen. Qualitative changes in fluorescent Pseudomonas spp. populations, like in vitro antagonism, are more likely to explain differences in soil conduciveness to take-all than are quantitative changes in this group. Nevertheless, the introduction of Ggt in a cropped soil leads to a greater increase in fluorescent pseudomonads populations than in total aerobic bacteria.The delay between reducing soil conduciveness and reducing disease in the field with ammonium nitrogen fertilization, the qualitative change of fluorescent pseudomonads populations and the role of necroses in rhizobacteria multiplication, provide information leading to our representation of a dynamic model based on the differentiation of the wheat root system into seminal and nodal roots.