Vaccination against Babesia bovis: T cells from protected and unprotected animals show different cytokine profiles

Vaccination of cattle against the haemoprotozoun parasite, Babesia bovis, with the recombinant antigen 11C5 resulted in 9 of 15 cattle being protected against challenge infection. The cellular immune responses of protected and unprotected cattle were compared in order to identify differences in response. No differences were observed in the pattern of change in various blood leukocyte populations throughout challenge infection. FACScan analysis revealed an increase in the proportion of cells bearing the CD2 marker in both protected and unprotected cattle over the course of infection. There were no observable differences in the frequency of various cell-surface markers between the unprotected and protected cattle. During the period of patent parasitaemia, in vitro cultures of peripheral blood mononuclear cells (PBMC) from protected cattle produced significantly more TNF- (P < 0.05) than cultures from unprotected cattle. TNF- concentrations remained at pre-challenge levels until day 10, when levels in the unvaccinated control and vaccinated/unprotected animals dropped. By peak parasitaemia, TNF- production in vitro was siguificantly greater (P < 0.05) in cultures of PBMCs from protected cattle. Interferon production showed an initial peak at day 5 in all cattle, followed by a decrease and a second peak at days 10–13 in protected cattle only, which coincided with resolution of the infection.     

Endotoxin Induces Severe Inflammatory Reactions with Necrosis at Sites Primed with Delayed-Type Hypersensitivity Reactions in Guinea Pigs

Guinea pigs immunized with Freund's complete adjuvant received challenge injection of the purified protein derivative of Mycobacterium tuberculosis in the flanks and the corneas to prepare delayed-type hypersensitivity (DTH) reactions. The animals were injected subcutaneously with lipopolysaccharide (LPS) or a synthetic lipid A (LA-15-PP). At the skin site primed with DTH reaction, increased swelling and hemorrhagic reaction followed by a definite necrotic reaction occurred. Severe corneal reactions were also observed in the animals. These findings indicate that bacterial endotoxin modulates DTH reactions and induces severe inflammatory reactions.     

Chemical induction of interleukin-8, a proinflammatory chemokine,in human epidermal keratinocyte cultures and its relation to cytogenetic toxicity

Tumor promoters, proinflammatory cytokines, endotoxins, and protein synthesis inhibitors can modulate cell cycle kinetics of various cell types, stimulate production of reactive oxygen species, and induce keratinocytes to produce interleukin-8 (IL-8), a potent chemotactant for polymorphonuclear neutrophils and T lymphocytes. The aim of this study was to determine whether perturbations of cytogenetic responses correlated with the induction of IL-8 expression. Cultures of primary human keratinocytes were grown in serum-free medium with 5 mol/L bromodeoxyuridine to label DNA and exposed either to phorbol-13-myristate-12-acetate (PMA) (0.0001–100 ng/ml), cycloheximice (CHX) (0.01–50 g), lipopolysaccharide (0.1–100 g/ml), tumor necrosis factor- (TNF) (3.13–50 ng/ml), or interleukin-1 (IL-1) (1–182 pg/ml). Metaphase chromosome preparations were stained by a fluorescence-plus-Giemsa technique to differentiate sister chromatids. For IL-8 production, keratinocytes were grown to 70% confluency and then exposed to chemicals for 24 h. Immunoreactive IL-8 was quantitated from the supernatants by ELISA. With the exception of benzo(a)pyrene used as a positive control, none of the agents induced sister chromatid exchanges. However, PMA and TNF induced IL-8 production that coincided with significant cell cycle inhibition. IL-1 had no effect on cytogenetic endpoints, yet stimulated a 6.3-fold increase in IL-8. CHX inhibited cell cycle progression and mitotic activity at concentrations that were 200 times lower than required for IL-8 induction; however, puromycin (0.31–10 g/ml), another protein synthesis inhibitor, did not induce IL-8. At all concentrations tested, TNF reduced the mitotic index by 45%, slowed cell cycle progression by 3.5 h, and induced a flat, albeit large, IL-8 response at concentrations 12.5 ng/ml. These agent-specific response patterns suggest that induction of IL-8 production is not always the inevitable result of cell cycle perturbations or genetic damage.Abbreviations B(a)P benzo(a)pyrene - BrdU 5-bromo-2-deoxyuridine - CHX cycloheximide - ICAM intercellular adhesion molecules - IL-1 interleukin-1 - IL-8 interleukin-8 - KGM keratinocyte growth medium - LPS lipopolysaccharide - PKC protein kinase C - PMA phorbol-13-myristate-12-acetate - PMN polymorphonuclear neutrophil - ROS reactive oxygen species - SCE sister chromatid exchange - TNF tumor necrosis factor      

Potentiation of antitumor effects of tumor necrosis factor α and interferon γ by macrophage-colony-stimulating factor in a MmB16 melanoma model in mice

The efficacy of systemic infusion of recombinant human macrophage-colony-stimulating factor (M-CSF) in combination with local treatment with human recombinant tumor necrosis factor (TNF) and mouse recombinant interferon (IFN) was studied in vivo on a subclone of B16 melanoma (MmB16) in mice. Short-term intravenous administration of M-CSF at a dose of 10⁶ units daily had no antitumor effect in vivo. Similarly, local treatment of tumor with TNF (5 g daily) did not produce any therapeutic effect. However, simultaneous administration of the same dose of TNF with IFN (1000 units daily) resulted in a synergistic effects manifested by the retardation of tumor growth. Addition of systemic infusion of M-CSF to the local therapy with TNF and IFN induced further augmentation of antitumor efficacy and delayed progression of MmB16 melanoma. The strengthened antitumor effect of combination therapy including M-CSF, TNF and IFN was most probably due to the increased release of monocytes from the bone marrow, their recruitment into the site of tumor growth and subsequent local stimulation of their antitumor activity.     

In vitro autoradiographic localization of [I]-angiotensin II binding sites in the rat and dog kidney

Light microscopic autoradiographic techniques have been utilized to demonstrate specific regions of the rat and dog kidney where angiotensin II receptors exist. Slide mounted tissue sections were labeled with [¹²⁵I]-angiotensin II using conditions which provided for highly specific binding. These angiotensin II binding sites were localized to several distinct renal structures. In the renal cortex, angiotensin II binding sites were found concentrated in all parts of the glomeruli including the vascular components, the macula densa and the juxtaglomerular apparatus. Angiotensin II binding in the medulla was more diffusely associated with the vasa recta, and to a lesser extent, the thick ascending segment of the loop of Henle. Binding sites specific for angiotensin II were also found in the smooth muscle laminae of the ureter. Scatchard analysis of the binding kinetics allowed the demonstration of two subpopulations of binding sites which differ slightly in their affinities for [¹²⁵I]-angiotensin II. These subpopulations appear to be associated with distinct components of the renal structure.     

Biological activities of chemically synthesized analogues of the nonreducing sugar moiety of lipid A

Adriamycin-Fe3+ complex catalyzes the formation of hydroxyl radical from hydrogen peroxide but the DNA-adriamycin-iron ternary complex is much more effective. 11-Deoxyadriamycin, which shows no spectral evidence of complex formation with iron, was ineffective. The generation of hydroxyl radical by adriamycin-Fe3+ complex in the presence of DNA correlates with its ability to cleave DNA. Hydroxyl radicals are thus implicated as the reactive oxygen species involved in the DNA damage caused by the adriamycin-Fe3+ complex.     

Properties of carnitine transport in rat kidney cortex slices

The properties of carnitine transport were studied in rat kidney cortex slices. Tissue: medium concentration gradients of 7.9 for L-[methyl-¹⁴C]carnitine were attained after 60-min incubation at 37°C in 40 μM substrate. L- and D-carnitine uptake showed saturability. The concentration curves appeared to consist of (1) a high-affinity component, and (2) a lower affinity site. When corrected for the latter components, the estimated K_m for L-carnitine was 90 μM and $\text{V = 22}\text{nmol/min}$ per ml intracellular fluid; for D-carnitine, $\text{K}{}_{\mathrm{<mtext>m</mtext>}}\text{= 166}\text{μM}$ and $\text{V = 15}\text{nmol/min}$ per ml intracellular fluid. The system was stereospecific for L-carnitine. The uptake of L-carnitine was inhibited by (1) D-carnitine, γ-butyrobetaine, and (2) acetyl-L-carnitine. γ-Butyrobetaine and acetyl-L-carnitine were competitive inhibitors of L-carnitine uptake. Carnitine transport was not significantly reduced by choline, betaine, lysine or γ-aminobutyric acid. Carnitine uptake was inhibited by 2,4-dinitrophenol, carbonyl cyanide $\text{m-}\text{chlorophenylhydrazone}$, N₂ atmosphere, KCN, $\text{N-}\text{ethylmaleimide}$, low temperature (4°C) and ouabain. Complete replacement of Na⁺ in the medium by Li⁺ reduced L- and D-carnitine uptake by 75 and 60%, respectively. Complete replacement of K⁺ or Ca²⁺ in the medium also significantly reduces carnitine uptake. Two roles for the carnitine transport system in kidney are proposed: (1) a renal tubule reabsorption system for the steady-state maintenance of plasma carnitine; and (2) maintenance of normal carnitine levels in kidney cells, which is required for fatty acid oxidation.     

Pathogenicity of Macroposthonia xenoplax to Walnut

Preplanting treatment of soil naturally infested with Macroposthonia xenoplax with 1,2-dibromoethane (ethylene dibromide) significantly increased the growth rate of Juglans hindsii seedlings. When seedlings of J. hindsii, J. regia CV "Serf" and J. regia CV Eureka were inoculated with M. xenoplax, their growth was signilicantly less than that of nematode-free controls. This retarded growth rate was accompanied hy feeder root necrosis, longitudinal cracks in the older roots, and distinct lesions in the secondary phloem.     

The treatment of the hepatorenal syndrome with intra-renal administration of prostaglandin E1

Three patients with the hepatorenal syndrome were treated with prostaglandin E₁ administered through a selective renal arterial catheter. Prostaglandin E₁ was given in progressively increasing doses (2 to 100 ng/kg/min) over a 60-minute period. Control plasma prostaglandin E levels were elevated in all three patients, 0.98, 0.91, and 0.83 ng/ml, respectively. At the end of the infusion, plasma prostaglandin E levels had risen to 10.4, 2.63, and 10.3 ng/ml in the three patients respectively. Plasma renin activity increased during the course of the infusion in two of the patients. The plasma aldosterone concentration did not change during the prostaglandin E₁ infusion. Intrarenal prostaglandin E₁ failed to increase urine volume or urinary sodium concentration in three patients with the hepatorenal syndrome.     

Renal function and pituitary hormone release during cerebral osmostimulation and TRH in dogs

The effects of increases in serum osmolality on renal function and plasma levels of radioimmunoassayable prolactin (PRL) and luteinizing hormone (LH) were examined during intracarotid (IC) infusions of hypertonic NaCl in conscious dogs with a sustained water diuresis (SWD). A 10 minute bilateral IC infusion of 45 μmole/kg·min·artery of NaCl during SWD which raised jugular osmolality by 10.1 mOsm/kg, without significantly altering peripheral venous osmolality, produced a significant decrease in free water clearance (C_H2O) at 20 to 40 minutes postinfusion. IC infusions of 0.9% NaCl did not produce an antidiuretic response. No change in heart rate or blood pressure from preinfusion control values occurred during NaCl infusions. Elevations in cerebral osmolality did not result in changes in circulating levels of LH or PRL which qualitatively differed from levels of these hormones recorded during IC infusions of 0.9% NaCl. Although fluctuations in levels of LH occurred during experiments, renal function was not concomitantly affected. The results suggest that a specificity exists in the hormonal response to selective elevations of cerebral osmolality. The administration of TRH 3.8–4.2 μg/kg produced a transient increase in blood pressure and inhibited a water diuresis, the latter possibly as a result of releasing antidiuretic hormone.