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The aim of this study was to evaluate the seroprevalence of B. burgdorferi and A. phagocytophila in populations of workers from 4 Italian regions, known to be exposed to tick bites. A total of 712 serum samples collected were divided as follows: 387 samples were obtained from workers at risk for tick bites and 325 from individuals that were not considered to be at risk of ticks bites and served as the control group. Antibodies against B. burgdorferi were found in 29 (7.5%) of the 387 risk workers and in 4 (1.2%) of the 325 control group. Antibodies reactive with the HGE agent were found in 22 (5.7%) of the 387 risk workers and in 3 (0.9%) of the 325 control group. Antibodies to both B. burgdorferi and A. phagocytophila were found in 1.6% of the forestry workers confirming the possibility of coinfection or concurrent infection. The present finding show significant differences between seroprevalence of the risk workers and that of the people with no risk for tick exposure.

From the experiments carried out in this study on mice kept on a 17.5% alcoholic diet (ethanol) for more than 90 days, a clear-out decrease was found in all the protective responses studied. In fact, the data show: (a) increased mortality with increased number of circulating bacteria; (b) diminished adherence and migrational capacity of polymorphonuclear leukocytes; (c) diminished phagocytosis index; (d) reduced release of cytokines from lymphocytes and monocytes; and (e) diminished response of lymphocytes to polyclonal stimuli (concanavalin A, lipopolysaccharide).

We have investigated the effect that lipopolysaccharide extracted from Chlamydia trachomatis has on human spermatozoa. A lipopolysaccharide of 0.1 microgram ml-1 caused a spermatozoa mortality rate of 65 +/- 4% evaluated by eosin exclusion test. The toxic activity occurred rapidly even after brief incubation times, reaching the maximum (100% mortality) within 60 min.

SUMMARY: The sensitizing effect and the local and general toxicity related to membrane components of the archaeobacterium Sulfolobus solfataricus was studied. Cell envelope fragments were biologically active but this activity was lost upon separation of the lipid and protein components. The envelope fragments exerted lethal effects on mice sensitized with D-galactosamine that were prevented by pretreatment with anti-TNF-α serum. This lethal activity occurred in both LPS-responder (BALB/cByJ) and LPS-nonresponder (C3H/HeJ) mouse strains. In addition, Sulfolobus envelope fragments tested in rabbits caused a local Shwartzman reaction, and showed pyrogenic activity. In vitro, the envelope fragments that act on spleen lymphocytes of the LPS-responder (BALB/cByJ) and LPS-nonresponder (C3H/HeJ) mice caused an uptake of [3H]thymidine similar to that caused by concanavalin A. A similar toxic activity to that exerted by eubacteria is therefore exerted by this non-pathogenic archaeobacterium despite the difference in surface chemistry.

In this study, we kept BALB/c mice on a hyperlipidic diet for 120 days and then assessed the predisposition to apoptosis and the appearance of heat shock protein (Hsp) on splenic lymphocytes. By immunoblot analysis, bands corresponding to Hsp 60 and Hsp 70 in cells from mice kept on a saturated fatty acid diet showed a greater expression already after 1 month while two other bands, which correspond to Hsp 25 and Hsp 27, were slightly present after 1 month of treatment. In cells from mice kept on a diet rich in unsaturated fatty acid, there was a marked expression of Hsp 25 and Hsp 27 after only 30 days of treatment, which was maintained constant for up to 4 months; while for bands corresponding to Hsp 60 and Hsp 70, a significant minor signal was only detectable after 2–4 months from the beginning of the treatment. Splenic lymphocytes from animals kept on a lipidic diet containing saturated fatty acids were more susceptible to death by apoptosis, while cells of animals treated with unsaturated fatty acid were shown to be more resistant.

Although Chlamydia trachomatis causes symptomatic infection in the lower genital tract of approximately 50% of men, its role in the upper genital tract is less well known. Moreover, for a number of reasons, mostly based on methodological aspects, the impact of chlamydia on semen quality is controversial. Overall, in-vivo studies of C trachomatis in men have provided conflicting evidence as to whether it is associated with reduced fertility. By contrast, in-vitro studies show that co-incubation of spermatozoa with chlamydia causes a significant decline in numbers of motile sperm and results in premature sperm death. Since evidence suggests that chlamydial lipopolysaccharide is the principal factor leading to sperm apoptosis, a new line of inquiry would be to measure the levels of lipopolysaccharide in semen and relate these to parameters of semen quality, including that of sperm function. If these new lines of inquiry are proven, this could lead to potentially novel approaches in the treatment of infertile men.

In the central nervous system, cytokine-activated microglia play a crucial role in host defence against Toxoplasma gondii infections. In this study, the effect of recombinant tumor necrosis factor (rTNF)-alpha and prolactin (PRL) on T. gondii infection in microglia was examined. Pretreatment of microglia with rTNF-alpha and PRL induced toxoplasmastatic activity, the intracellular killing of T. gondii and the release of interleukin (IL)-1 beta IL-3 and IL-6: 50% of the intracellular killing was abrogated by anti-ICAM-1 monoclonal antibodies, whereas more than 54 or 87% of toxoplasmastatic activity was reversed by anti-IL-3 or IL-6 monoclonal antibodies. In addition, the treatment of microglia with either rIL-3 or rIL-6, in the absence or presence of rTNF-alpha significantly limited T. gondii replication. Inasmuch as either NMA or S-M-ITU affected cytokine-activated toxoplasmastatic activity during the infection phase, the NO-dependent pathway itself appears not to be directly involved in the parasitostatic activity. These findings suggest that TNF-alpha and PRL up-regulate the expression of ICAM-1 and the production of endogenous IL-6 and IL-3 by microglia, which could induce anti-parasitic functions against T. gondii infection in the brain.

The production of hsp and apoptosis of leukocytes in the peripheral blood of animals naturally infected with Brucella spp or treated with the vaccine Brucella abortus 19 have been investigated in this study. Cytokines able to induce phagocytic activity in macrophages of non treated healthy animals were found in the supernatant of bovine leukocytes cultivated in vitro. A long-lasting antibody response against hsp 60 kDa and 27 kDa, which lasts a long time, is induced in naturally infected animals, while in animals vaccinated with B. abortus 19 we detected an antibody response against hsp 60 and 70 kDa which is much shorter, disappearing in two months. During the early phase of infection, lymphocytes and monocytes of naturally infected animals show a delay of apoptosis in vitro compared to the same cells coming from healthy controls and vaccinated animals.

Cytokine-activated human vein endothelial cells (HUVEC) may play an important role in resistance to Toxoplasma gondii infection. In this study, it was investigated the role of rTNF-alpha and GH in the induction of antitoxoplasmal activities in HUVEC. Co-treatment of HUVEC with rTNF-alpha plus GH induced both toxoplasmastatic activity and the intracellular killing of T. gondii (p0.01 each vs untreated cells). Thus, these functions were inhibited by both neutralizing antibodies to IL-6 and GM-CSF (but not to IL-3) suggesting that these cytokines participate in the inhibitory process. Consistent with this hypothesis, the treatment of HUVEC with rIL-6 or rGM-CSF in the presence of rTNF-alpha, limited T. gondii multiplication in a dose-dependent manner (p0.01 each vs untreated cells). In order to elucidate the inhibitory mechanism of HUVEC, it was assessed by L-arginine analogs (e.g., NG-monomethyl-arginine) whether NO2 molecules originating from HUVEC were directly or indirectly involved in the rTNF-alpha/GH-dependent induction of toxoplasmastatic activity. A good correlation was found between toxoplasmastatic activity and NO2 release during the activation phase, before infection of the HUVEC with T. gondii, but no correlation was found between the parasitostatic activity and NO2 release during the infection phase. These data indicate that NO2- itself does not directly affect toxoplasmastatic activity. Besides, the reduction of intracellular killing by monoclonal antibodies to ICAM-1 suggest that this adhesin plays a role in controlling T. gondii entry into cells.

SUMMARY An experimental model of immunological deficiency obtained by treating mice for 6 months with serum of human blood drawn from different healthy individuals has been studied. The results show that an alteration of a circulating lymphocyte population with alterations of the ratio CD4+/CD8+ appeared in mice stimulated for a long period with immunogens. Mice treated for 2–4 months showed an increase in B lymphocytes and a decrease in the total number of T lymphocytes, with a decrease in CD4+ lymphocytes and an increase in CD8+ lymphocytes. After 4 months, the CD8+ lymphocyte population started to decrease, with a ratio of CD4+/CD8+ reaching almost 1. In animals treated for 2–3 months, the mean survival time (MST) following experimental infection with Salmonella typhimurium presented a decrease to 5 days, and after 5–6 months of treatment presented a decrease to 3-2-5 days. The bacteraemia was modified in comparison with controls. Prolonged exposure to antigens also induced lymphocyte apoptosis: cells of animals treated for 4–6 months presented increased levels of apoptosis with a percentage that reached 30–35%. A semiquantitative evaluation of the level of heat shock protein (hsp) in splenic lymphocytes showed an increase in the presence of hsp60 and hsp70 in the first 3 months of treatment, which then remained constant for up to 6 months.

Liposomes consisting of dicetyl-phosphate, cholesterol, lecithin and stearic or myristic or oleic acid, exert a protective effect for mice against experimental infection by Salmonella typhimurium, and delay both the onset and mortality B16 melanoma in these animals. Liposomes labelled with 3H-myristic acid were used as probes in the spleen and liver. We found that the treatment schedule rather than route of administration of liposomes, is important. The results show that in order to induce protection, preventive treatment must start at least three days before. Longer treatments do not increase the degree of protection, and treatments started at the same time as, or following experimental infection or tumor transplantation, have no effect.

Rabbits immunized for 6 months with different amounts of sterile human serum showed weight loss and a decrease in leukocytes. The lymphocyte population reacting to ConA contained autoreactive cells capable of causing 51Cr release from labeled cells from a culture consisting of splenic and peripheral lymphocytic cells from the same animal.

Female mice were maintained on a lipid-rich diet. After 33 days, the mice showed a decrease in the cell population bearing MHC class II molecules, and in the production of interleukin-1 (IL-1). After 60 days, we reported a further decrease of the cell population with MHC class II molecules and the secretion IL-1.

Adherence, metabolic burst and chemotaxis of polymorphonuclear neutrophils (PMNs) were examined in 15 children before and seven days after measles-mumps-rubella vaccine administration. In all children, PMN functions were significantly reduced on the seventh day. Adherence, metabolic burst and chemotaxis tested in three subjects one month after vaccination had returned to normal values. Only two children presented transient hyperpyrexia. We conclude that measles-mumps-rubella vaccine administration suppresses PMN functions without clinical consequences. This is probably because attenuated strains of vaccine viruses do not replicate in lymphoid tissues as extensively as do wild-type strains.

Studies were carried out on the ability of protein A (PA) and of muramic acid (MA) from S. aureus to induce the release of cytokines both from monocytes and lymphocytes in vitro. Results show that protein A induces the greatest activity, compared to the activity already known for the theicoic acid (TA) and for muramyl dipeptide (MDP). At concentration of 10 micrograms/ml; PA induces roughly +180% release of TNF with respect to controls, while release of IL-1 alpha is about 500% control values, and is higher than those obtained when cells are treated with TA and MDP; IL-6 release is higher than that stimulated by Con A, used as standard challenge. At PA concentrations of 5 micrograms/ml, IL-4 release is about five times higher than that induced by Con A. Release of IFN-gamma showed similar dose-dependent stimulations. Muramic acid (MA) is particularly active in inducing the release of cytokines from target cells, inducing TNF release of about +75% with respect to the controls. This increase is less than that obtained with PA. Also IL-4 and IFN-gamma are released by PA in quantities higher than those induced by TA and MDP. Our results lead us to believe that during infections by Gram-positive bacteria, their surface components are able to induce a series of chain reactions ranging from the inflammatory to the immunologic responses which are also conditioned by release of cytokines.

The effect of SV-IV, one of the major proteins secreted from the rat seminal vesicle epithelium, on phagocytosis and chemotaxis of human polymorphonuclear leukocytes (PMNs) has been studied. Various cytological, biochemical, metabolic, and physical correlates of both biological activities have been found to be markedly reduced by the presence in the medium of micromolar concentrations of protein SV-IV. Moreover, the Scatchard analysis of the labeled SV-IV binding to PMN cell surface has demonstrated that such binding is specific. The binding sites contain only saturable components, completely displaceable by unlabeled SV-IV. The number of the specific sites has been calculated to be 87,000/cell, with a Kd of 1.72 x 10-7 M. The molecular mechanism of the inhibitory effect is discussed along with the possible biological and clinical implications of the experimental findings.

The adherence of polymorphonuclear neutrophils was examined in 16 children affected by enteritis, pneumonia, hepatitis and infectious mononucleosis. The results were compared with those obtained in 30 healthy adult volunteers and in 15 healthy children of the same age. Adhesiveness was significantly higher in adults than in healthy children, and significantly higher in healthy children than in children with viral infection. In 7 patients tested one month after regression of the disorder, PMN adhesiveness had returned to normal.

The kinetics of potassium exchange in cells of Staphylococcus aureus with 42 K + as a tracer in the extracellular potassium phase, was investigated. In phosphate buffer and KCl, in the absence of glucose, results showed that equilibration of distribution of external specific radioactivity and internal specific radioactivity was not achieved because the cells continuously lose potassium. In the presence of glucose, however, results showed no loss of potassium from the cells, and the potassium phase in the cells remained stationary, so that an equilibrium between intracellular and extracellular specific radioactivity was achieved. Sodium azide and dinitrophenol, added in both the absence and presence of glucose, did not have any effect on exchange as compared with controls. If, however, DL -glyceraldehyde was added in the experiments in the presence of glucose, no utilization of the carbon source, and the same behaviour for the cells as in the absence of glucose, was observed. Incubation temperature has a marked effect: potassium-exchange rate is greatly decreased at a temperature of 4°. Increasing concentrations of potassium in the suspension medium did not affect the exchange rate for concentrations higher than 3–4 mequiv potassium per 1.

The effect of SV-IV, one of the major proteins secreted from the rat seminal vesicle epithelium, on phagocytosis and chemotaxis of human polymorphonuclear leukocytes (PMNs) has been studied. Various cytological, biochemical, metabolic, and physical co¬relates of both biological activities have been found to be markedly reduced by the presence in the medium of micromolar concentrations of protein SV-IV. Moreover, the Scatchard analysis of the labeled SV-IV binding to PMN cell surface has demonstrated that such binding is specific. The binding sites contain only saturable components, completely displaceable by unlabeled SV-IV. The number of the specific sites has been calculated to be 87,000/cell, with a Kd of 1.72 x 10-7 M. The molecular mechanism of the inhibitory effect is discussed along with the possible biological and clinical implications of the experimental findings.

Nine new cytotoxic steroidal glycosides 1-9 have been isolated from the starfish Fromia monilis collected off New Caledonia. Structures of these compounds, which include four mono- (1-4), two di- (5, 6), and three tri-glycosides (7-9), were elucidated through spectral interpretation. Monilosides G [7], H [8], and 1 [9] are the first tri-glycosides to be found among the group of glycosides of polyhydroxilated steroids from starfishes.

In aerobiosi lad-l-gliceraldeide a notevoli concentrazioni ha una lievissima azione inibente sulla ossidazione del glucosio e sulla incorporazione di leucina-C14. In condizioni di anaerobiosi invece lad-l-gliceraldeide in concentrazioni medie inibisce notevolmente sia la glicolisi che la incorporazione di leucina-C14.

It was shown that bacteria of mucosae of higher organisms, mostly have specific receptors for chemical complementary structures of cell surface. On the other hand it is known already that vaginal flora changes during ovulation and afterwards, some infections begin and reveal during some periods of the ovulatory cycle. Therefore, it was studied the adherence of saprophytic and pathogenic bacteria to vaginal cell in different phases of the ovulatory cycle. It was shown that, during the cycle, the bacterial adherence changes because of environment modifications, caused by secretion under hormonal control.

Female mice were maintained on lipid diet for 20 days. The nonspecific and immunological defense capability was determined by in vitro and in vivo methods. It was found that mice held mostly on a lipid diet demonstrate an all-round lowered response. Following 20 days of lipid diet the splenocytes exhibit: (1) an inversed lipid-protein ratio; (2) an inability to respond to sheep erythrocytes; (3) a reduction in [3H] thymidine incorporation in splenocytes stimulated with lipopolysaccharide (LPS) or with concanavalin A; (4) a reduction in the number of cells bearing surface immunoglobulins in splenocytes stimulated with LPS; (5) an inhibition of phagocytosis and intracellular killing in macrophages; (6) a lowering in granulocyte chemotaxis and adherence capacity; (7) a higher mortality to LPS after loading with galactosamine; and (8) a lowered complement activity even following LPS activation.

Cytoplasmic membrane of E. coli is degraded within 20 min following infection with Bdellovibrio. 50% of cellular 42-K is lost during the first 10 min. The cytoplasmic membrane, 20 min after infection, centrifugated on a sucrose gradient produces a wide band containing the main enzyme activities (succinic dehydrogenase and lactic dehydrogenase) bound to the membrane. The incorporation into Bdellovibrio of labelled host cell constituents during intracellular growth has been studied at successive intervals during the development cycle in diluted nutrient broth (about 3 hrs). The cells were broken in a Sorvall-Ribi cell fractionator and the Bdellovibrios separated by centrifugation on sucrose gradient. Polysaccharides, proteins and lipids of Bdellovibrio derive from the utilization of components of the host cells and not from the utilization of the components present in the medium. The incorporation of precursors into polysaccharides and proteins shows the same exponential pattern.

The cardiovascular effects of porins were evaluated using porins isolated from Salmonella typhimurium SH5014. In dogs porins depress arterial systemic pressure, vasomotor reactivity of norepinephrine and peripheral vagal stimulation. They are capable of modifying the sinocarotidal baroreceptor reactivity. In mice porins increase the cardiotoxic effects of isoprenaline, thyroxine, emetine and of p-nitrophenol. In rats porins increase the arrhythmogenic and lethal effects of BaCl2 and also give rise to renal lesions, probably at the tubular level.

The Authors report the data of a study of lymphocyte subpopulations (T lymphocytes as rosette forming cells, B lymphocytes as surface immunoglobulin bearing cells, Ea cells as active rosette forming cells, EAC cells, with a receptor for complement, and EA cells, with a receptor for Fc fragment) in venous blood of a group of newborn babies including at term and preterm subjects and babies with and without bacterial infections. A group of healthy adults was also examined as control. Main findings were the following: a) in the group of newborn babies with infection the number of lymphocytes/microliter was higher as compared to that of newborn babies without infections and of adult controls; b) the percentage of T lymphocytes was significantly lower in the two groups of newborn but the absolute number was comparable; c) active rosette forming cells behaved as T lymphocytes; d) absolute number of B lymphocytes was significantly higher in newborn babies with infection as compared to newborn babies without infection and adult controls; e) newborn with infections showed also higher absolute number of EA rosette; f) EAC rosette behaved as T lymphocytes and active rosette forming cells. The increase of B lymphocytes in babies with infection is interpreted as an acceleration of the maturation of lymphocyte populations toward the pattern of older ages. The increase of EA rosette forming cells is tentatively interpreted as an increase of K lymphocytes fostered by infection.

A study has been made of the distribution of bacterial flora in the gastro-enteric tract of rats fed on glycidic, protein and lipidic diets and compared with that found in rats given a standard diet. The flora of the gastro-enteric tract was noted in a fraction adhering to the epithelial cells of the mucous membrane and in a fraction present in the contents of the gastro-enteric tract. Changes resulting from the differences in diet are made particularly at the expense of the adhering flora. In groups fed on a glycidic diet there is a clear prevalence of enterococci, enterobacteria, lactobacilli, peptostreptococci and yeasts. In rats fed on a protein diet the quantity and variability fo the flora are less and clostridia predominate. Where rats are given a lipidic diet there is a prevalence of enterobacteria, lactobacilli and peptostreptococci. An extensive and diversified colonization is noted as a further consequence of differences in diet. The results obtained are discussed in relation to certain pathological intestinal conditions and to results reported elsewhere in the literature.

A study was conducted on the granulocytic phagocytosis of bacterial aggregates obtained under ideal environmental conditions. For the strains studied, aggregation was favored by low salt concentrations, low pH and temperatures between 30 degrees C and 40 degrees C. Our results show that the phagocytic capacity of granulocytes depends on the type and size of these aggregates. Those formed by a smaller number of cells are more easily phagocytized than the larger ones.

Granulocytes from diabetic subjects have impaired ability to engulf bacteria; the data obtained suggest that the alterations are correlated with an increase in surface hydrophobicity, as measured by contact angle.

Porins interact with macrophage membranes and inhibit their phagocyting activity. We have tested the porin effect on a biologically relevant membrane-bound enzymic activity, the adenylate cyclase system, which appears to be stimulated both in the presence of Mn2+ and Mg2+ or Mg2+ + Gpp(NH)p. Moreover, for mice macrophages incubated in the presence of porins, there is an increase in the intracellular cAMP content after 5 min of incubation, with a maximum after 15 min of incubation. The results shown suggest that the porin effects on the adenylate cyclase can represent the molecular basis of the porin-dependent inhibition of the macrophages phagocytosis. Our point of view, which proposes a cAMP role in inhibiting the phagocyting activity in macrophages, is supported also by the results of the experiments carried out in the presence of both dibutyryl-cAMP or aminophylline. The phagocyting activity is inhibited in all cases and independently of the bacteria to be phagocyted.

Escherichia coli K12 suspended in different media showed a loss of phospholipids. Mg2+ and Ca2+ 0.01 M prevented phospholipid loss and stabilized Escherichia coli K12 for bactericidal and bacteriolytic assays.

The adherence of bacterial cells to valvular prostheses has been studied. Bacteria were selected on the. basis of their surface features (fimbriae, hydrophobicity and specific receptors). It was found that only strains having fimbriae and high cell surface hydrophobicity adhered to bioprostheses, while they did not adhere to metallic prostheses to any significant extent. Adherence to bioprostheses depended on the exposure time and it was affected by the saline concentration of the suspension medium. Furthermore, different bacterial binding capacity was observed for bioprostheses from different companies.