Impairment of the human phagocyte oxidative responses caused by Leishmania lipophosphoglycan (LPG): in vitro studies

Lipophosphoglycan (LPG), a surface glycoconjugate of Leishmania promastigotes, has been reported as playing an active role in protecting the parasite within phagolysosomes, by an impairment of monocyte oxidative responses. In this study the effect of LPG on the oxidative burst of human peripheral monocytes, eosinophils and neutrophils was evaluated. Our results demonstrated that either superoxide anion (O2-) or hydrogen peroxide (H2O2) release by LPG-pretreated cells was diminished, emphasizing the ability of this glycoconjugate to impair the oxidative activity of all phagocytes.

Immunological changes produced in rats by prenatal exposure to carbon monoxide

Wistar female rats were exposed to relatively mild concentrations of carbon monoxide (CO) (75 and 150 p.p.m.) from day 0 to day 20 of pregnancy. The results show that splenic macrophage phagocytosis of Candida albicans was significantly decreased in 15 and 21 day old male rats exposed to CO (150 p.p.m.) during pregnancy. Moreover, splenic macrophage killing was significantly reduced in 15 day old male pups prenatally exposed to 75 and 150 ppm of CO. Prenatal CO (150 p.p.m.) significantly decreased splenic macrophage O2- release in both 15 and 21 day old pups. CO-induced alterations in the immune system were not observed in 60 day old rats. These findings indicate that gestational exposure to relatively mild concentrations of CO induces in rat offspring reversible immunological changes characterized by an altered splenic macrophage function.

Effectiveness of thymostimulin and study of lymphocyte-dependent antibacterial activity in children with recurrent respiratory infections

Recurrent respiratory infections (RRI) consist of more relapsing acute respiratory infections than the ones expected for the age [> 6 acute respiratory tract infections (RTI) per year if age is > 3 years, and > 8 acute RTI per year if age is < 3 years]. Concerning the pathogenesis of RRI, several investigations report the important role of environmental factors, early socialization and immunological dysfunctions, such as lymphocyte subpopulations alterations, IgG subclass deficiency and phagocytosis and/or opsonization deficit during acute infections. In this framework, we have studied the lymphocyte-dependent antibacterial activity (ABA) among 121 children affected by RRI. Results show a statistically significant alteration of this function in 38 children (31.4%): 19 of them exhibited an absent ABA (group 1), while in the others same function was reduced (group 2). A bovine thymic extract, thymostimulin, was administered to both groups by intramuscular injections (1 mg/kg) for a 3 month cycle. At the end of therapy we observed a statistical significant rise of ABA only in group 1 and among children aged > 3 years. Among the same patients, 33 children (86.8%) improved in terms of reduction of clinical score and better results were seen among children aged > 3 years. These data emphasize the beneficial role of thymostimulin in RRI-affected children, suggesting a transient immaturity of the immune system as one of the possible pathogenetic factor.

In vivo effects of alprazolam and lorazepam on the immune response in patients with migraine without aura

Over the past few years, the immunomodulating role of benzodiazepines (BDZ) has been reported in literature. In particular, diazepam is an inhibitory BDZ with regard to its effects on the phagocytic and metabolic activities of polymorphonuclear cells (PMN) and monocytes, while triazolobenzodiazepines (alprazolam and triazolam) upregulate normal human peripheral blood T lymphocyte function. On these grounds, the administration of alprazolam (1 mg/per day for 1 month) in 13 patients with migraine without aura (MWA) and of lorazepam (2 mg/per day for 1 month) in 10 matched MWA subjects has been evaluated in terms of immune response. Results show that before administration of BDZ in both groups of patients phagocytosis and killing of PMN and monocytes were profoundly depressed and the same was true for the lymphocyte-dependent antibacterial activity. After one month treatment lorazepam further decreased lymphocyte function without modifying phagocytic capabilities. On the contrary, alprazolam increased PMN phagocytosis and killing and monocyte phagocytosis without modifying antibacterial activity values. Taken together, these results further support the existence of different classes of BDZ in terms of their immunomodulating capacities. Moreover, alprazolam seems to be a more appropriate BDZ for treating immunocompromised patients, even including MWA patients.

Studies on the epidemiology of child infections in the Bari area (south Italy). VII. Epidemiology of Epstein-Barr virus infections

Serological patterns against Epstein-Barr virus (EBV) specific antigens were determined in 3732 healthy babies and children aged 0-10 years living in the Bari area (South Italy). IgG antibodies against EBV capsid antigen (VCA) were found in 2713 subjects (72.7%). Seropositivity rates, high in the first semester of life (83.8%), declined between 6 and 12 months (65.6%) and even further between 1 and 2 years (43.8%). After 2 years the frequency of positive children rose progressively reaching steady levels between 5 and 7 years (80.2%) and between 8 and 10 years (81.9%). IgA antibodies against VCA, IgG anti-early viral antigen (EA) and IgG against virus-associated nuclear antigens (EBNA) were found in 17.9%, 15.9% and 25.7% of the subjects tested, respectively. IgM anti-VCA were found only in 35 (0.9%) children, but 818 (21.9%) exhibited antibody patterns suggestive of a recent infection: IgG anti-VCA > or = 1:160 alone or in association with IgA anti-VCA or IgG anti-EA or both. These results suggest that in this area the primary infection by EBV occur early in life, with immunity to EBV acquired primarily after 4 years.

Relationship between respiratory burst and adhesiveness capacity in elderly polymorphonuclear cells

Polymorphonuclear cell (PMN) activation was assessed in 30 aged donors, in terms of either adherence to different substrates or superoxide anion (O2-) generation by adhering and suspended cells in response to several agonists. Results showed that PMN in suspension from elderly individuals displayed a phorbol 12-myristate 13-acetate (PMA)-triggered O2- responsiveness which overlapped that seen in the younger counterpart, while a significant decrease of respiratory burst was observed in the presence of formyl-methionyl-leucine-phenylalanine (FMLP). Moreover, in spite of a normal nylon fiber adhesiveness, aged individuals exhibited a reduced PMN adherence to foetal calf serum (FCS)-coated plastic surfaces by using either PMA or FMLP as stimulant. However, elderly adhering cells produced higher amounts of O2- than homologous neutrophils in suspension. Cell pretreatment with anti-CD11b, anti-CD11c and anti-CD18 antibodies led to a further inhibition of PMN adhesion to FCS-coated plates. By contrast, under the same experimental conditions, O2- generation from adhering cells was reduced by using anti-CD18 antibody only. Altogether, these findings provide additional evidence for an imbalance of PMN-mediated functions in the elderly.

Triazolobenzodiazepines exert immunopotentiating activities on normal human peripheral blood lymphocytes

Previous studies have demonstrated that benzodiazepines (BDZ) (e.g. diazepam) inhibit immune responsiveness. Since these drugs are largely used in psychiatric patients it is of great importance to verify the existence of different types of BDZ, which are not suppressive for the immune system. In this framework, our results indicate that alprazolam and triazolam, two triazolo-BDZ, do not modify in vitro phagocytosis and killing exerted by normal human polimorphonuclear cells and monocytes. On the contrary, they significantly enhance T lymphocyte-dependent antibacterial activity in normal donors. These data support the concept that triazolo-BDZ and, in particular, alprazolam may represent more appropriate drugs for the treatment of psychiatric patients (e.g. patients with phobic disorders and/or migraine) who display immunodeficits.

[Isoproterenol causes changes in the mitochondrial energy metabolism in the rat heart]

In this paper we report observations on kinetic and structural characteristics of mitochondrial ATP synthase of rat-heart after subcutaneous injection of isoproterenol. The results obtained indicate: a decrease of respiratory rate either in absence (state 4) or in presence (state 3) of oxidative phosphorylation; decrease of respiratory control ratio; decrease of ATP hydrolase activity in sonic submitochondrial particles; decrease of relative content of the catalytic subunit F1 with respect to the membrane sector F0. The data obtained are in favour of the hypothesis that isoproterenol causes structural and functional alterations of mitochondrial ATP synthase.

In vivo administration of propranolol decreases exaggerated amounts of serum TNF-alpha in patients with migraine without aura. Possible mechanism of action

Patients with migraine without aura (MWA) display elevated amounts of Tumor Necrosis Factor (TNF)-alpha in their sera. In this study in 18 patients with MWA the in vivo effect of propranolol, a beta blocker agent, was evaluated with regard to the TNF serum levels before and after treatment. Results show that in 9 out 11 patients exaggerated serum concentrations of TNF reverted to normality after three months of therapy. Some hypotheses on the mechanisms of action of propranolol in terms of modulation of the immune response are formulated.

Neurological damage mediated by cytokines

Our results suggest that CKs, in particular Interleukin-1 and Tumor Necrosis Factor (TNF)-alpha, are involved in the pathogenesis of some neurological disorders and HIV infection. Infact, we observed an exaggerated spontaneous release of TNF-alpha in patients with migraine without aura. Furthermore, in a broad spectrum of patients with HIV-infection we have also found increased amounts of serum TNF-alfa and IL-1. Interestingly, a strict correlation between plasma lipopolysaccharide (LPS) and IL-1 or TNF-alpha levels seems to exist in both group of patients, thus indicating that LPS could account for the production of CKs in the course of the above diseases.

Interleukin-1 beta and beta-endorphin circadian rhythms are inversely related in normal and stress-altered sleep

Normal sleep is associated to physiological nocturnal rises in Interleukin 1 beta (IL 1 beta) secretion. The 24 h pattern of IL 1 beta, beta-Endorphin (beta-EPH), ACTH and cortisol (F) production was evaluated in four male healthy volunteers. Two subjects were unable to sleep, due to the stress of the experiment; in these cases, no detectable plasma IL 1 beta secretion, both diurnal and nocturnal, was present, beta-EPH plasma levels were significantly higher (p < 0.01) than in the subjects who slept regularly and, in one case, increased F plasma levels were also reported. A strong negative correlation between IL 1 beta and beta-EPH plasma levels was present in all the cases. In conclusion, stress-induced sleep alterations might deeply affect both diurnal and nocturnal IL 1 beta plasma secretion, probably due to the hypothalamus-pituitary-adrenal axis (HPAA) activation, and beta-EPH might be the reliable marker of the stress-induced HPAA activation level.

Tumour necrosis factor (TNF-alpha) and neurological disorders in HIV infection

Tumour necrosis factor (TNF-alpha) concentrations were determined in the CSF from 42 HIV-infected patients, with or without CNS involvement. In addition, 14 subjects with various neurological disorders but without HIV antibodies were included as controls. Raised CSF concentrations of TNF-alpha (greater than 40 ng/l) were detected both in patients with AIDS dementia complex (ADC) (6/9) and with CNS opportunistic infections (10/19) and, less commonly, in HIV infected subjects without CNS diseases (2/14) and in anti-HIV negative controls (1/14). The highest CSF concentrations of TNF-alpha (greater than 100 ng/l), however, were found in seven out of eight patients with cryptococcal meningitis. Although a role for TNF-alpha in demyelinating lesions associated with ADC has been suggested, our results indicate that a clear elevation of TNF-alpha in the CSF from HIV positive patients mostly occurs in acute inflammatory disorders, such as cryptococcal meningitis.

Cerebrospinal fluid myelin basic protein as predictive marker of demyelination in AIDS dementia complex

Myelin basic protein (MBP) was measured in cerebrospinal fluid (CSF) of patients with acquired immunodeficiency syndrome (AIDS) dementia complex (ADC) in order to investigate the degree of white matter destruction. Results show that increased CSF levels of MBP were detected in all patients with severe ADC (10/10) and, less often, in subjects with mild (2/7) or moderate dementia (7/16). No evidence of MBP-elevated concentration was observed in 14 human immunodeficiency virus (HIV)-seropositive subjects without neurological disorders and in nine HIV-seronegative controls. Our findings suggest that the measurement of CSF MBP concentration may represent a predictive marker of myelin injury and neurologic damage during the course of ADC.

L-carnitine deficiency in AIDS patients

OBJECTIVE

To evaluate carnitine (3-hydroxy-4-N-trimethyl-ammoniobutanoate) deficiency in AIDS patients by measuring serum total, free and short-chain carnitine concentrations.

DESIGN

We conducted an open study.

SETTING

All patients were seen at the Infectious Diseases Clinic, Università 'La Sapienza', Rome, Italy.

PATIENTS, PARTICIPANTS

Twenty-nine AIDS patients, aged 27-41 years, with a previous history of drug use; and 14 healthy age- and sex-matched controls were studied.

INTERVENTIONS

Study subjects were administered 500-800 mg zidovudine daily for 2 to 28 months (8 +/- 6 months).

MAIN OUTCOME MEASURES

Carnitine deficiency was suspected in study participants prior to data collection because of previously reported cardiac symptoms, muscle weakness, hypometabolism and/or cachexia.

RESULTS

A marked decrease in total and free carnitine was observed in 21 (72%) subjects. Nine of these patients also had low levels of short-chain carnitine.

CONCLUSIONS

AIDS patients may become carnitine-depleted and therefore at risk for alterations in fatty-acid oxidation and energy supply.

Enhancement of polymorphonuclear cell phagocytosis by lipid A-activated monocytes via cell-to-cell contact. A possible role for membrane-associated cytokines

Previous findings have shown that lipopolysaccharide (LPS)-activated human monocytes express cytokines (CKs) on their membrane. Furthermore, those associated to membrane products such as tumor necrosis factor (TNF)-alpha and interleukin (IL)-1 have been demonstrated to exert many biological activities. In this paper, evidence is provided that human polymorphonuclear cells (PMN) exhibited an increased phagocytic capacity following incubation with either lipid A (LA)-activated autologous monocytes or supernatants recovered from LA-stimulated mononuclear cell cultures. In order to investigate the possible role of monocyte membrane-associated TNF-alpha, IL-1 alpha and IL-1 beta in the modulation of PMN activity, in a separate series of experiments LA-activated monocytes or LA-activated supernatants were pretreated with anti-recombinant human (Rhu) TNF alpha, anti-Rhu IL-1 alpha and anti-Rhu IL-1 beta monoclonal antibodies (MoAbs), respectively. Such an approach gave rise to an abrogation of monocyte-mediated triggering effect on PMN functional capacity. Taken together, these data suggest that activated monocytes can upregulate PMN phagocytosis by a cell-to-cell contact mechanism, likely related to membrane-associated CKs.

Effect of Bifidobacterium bifidum and Lactobacillus acidophilus on gut mucosa and peripheral blood B lymphocytes

In 15 elderly individuals lyophilized Bifidobacterium bifidum (BB) and Lactobacillus acidophilus (LA) (Infloran) were administered in capsules (two capsules 4 times per day) for 28 days, while in 10 elderly controls placebo were given the same posology and for an equal period of time. The effects of this treatment on the immune system both at the periphery or the intestinal level were investigated. Results show that BB and LA significantly reduced the colonic inflammatory infiltration, without altering T, B and Leu7 + cell percentage. At the same time, a significant increase of B cell frequency in the peripheral blood was noted, in comparison to controls. The overall results suggest that the regular administration of BB and LA leads to a modulation of the immunological and inflammatory response in elderly subjects.

Thymostimulin administration modulates polymorph metabolic pathway in patients with chronic obstructive pulmonary disease

Several studies outline the imbalance of phagocyte functions in chronic obstructive pulmonary disease (COPD). In this regard, here, we have assessed either monocyte- and polymorphonuclear cell (PMN)-mediated chemotactic, phagocytic and killing capacities or PMN-triggered metabolic pathway in a group of COPD patients before and at different times after thymostimulin administration. Before therapy, an increase of O2-generation and a decrease of myeloperoxidase release were found in these individuals when compared to controls. Moreover, a reduction of either PMN-mediated chemotaxis and killing or monocyte chemotactic capacities was observed. By contrast, no differences were seen in terms of beta-glucuronidase release, monocyte-mediated killing and PMN or monocyte phagocytic function. During a one-year monitoring following immunotherapy, O2- production and myeloperoxidase activity fell within normal values, while phagocyte functional capacities were unaffected by such a treatment. Furthermore, COPD subjects exhibited a significant improvement of their clinical status as assessed during a one-year followup. All together, these findings suggest a potential role for thymostimulin in the treatment of COPD patients.

On the physiological significance of tumor necrosis factor-alpha in the human amniotic fluid

Tumor Necrosis Factor (TNF)-alpha and Interleukin (IL)-1 beta levels have been measured in 16 weeks gestation amniotic fluids and mother's sera. Detectable levels of TNF-alpha were found in amniotic fluids, while IL-1 beta was absent. No cytokines were detected in mother's sera. The possible role of TNF-alpha as growth factor for fetal hematopoietic cells is discussed.

Increased spontaneous release of tumor necrosis factor-alpha/cachectin in headache patients. A possible correlation with plasma endotoxin and hypothalamic-pituitary-adrenal axis

Tumor Necrosis Factor-alpha/cachectin (TNF-alpha/cachectin), Lipopolysaccharide (LPS), ACTH, beta-Endorphin (beta-EPH), and Cortisol (F) levels were determined in 33 Headache patients: 22 patients were affected with Migraine (M) and 11 patients with Chronic Type Tension Headache (CTTH). TNF-alpha/cachectin serum level was detected in 15 out of 22 migraneous patients and in no CTTH patients. Plasma LPS was observed in 11 out of 15 TNF-alpha/cachectin positive migraneous patients (73%) and in 3 out of 11 CTTH patients (27%). A negative correlation was observed between TNF-alpha/cachectin values and either ACTH or beta-EPH. In the group of migraneous patients the presence of serum TNF-alpha/cachectin showed a sensibility of .6 and a specificity of 1. The endocrine and immunological implications concerning these data are discussed.

On the spontaneous adherence of myelin basic protein to T lymphocytes

We have applied a double tagging system in order to study whether purified myelin basic protein is able to adhere to normal human peripheral T lymphocytes without the need to purify cells. Evaluation of myelin basic protein adherence to peripheral blood mononuclear cells was determined with biotinylated myelin basic protein and fluoresceinated avidin, and lymphocyte population was identified by the corresponding phycoerythrinated monoclonal antibody. The observed adherence of myelin basic protein to T lymphocytes was found to depend on protein conformation.

Effects of benzodiazepines on the immune system

Benzodiazepines (BDZ) are psychotropic drugs largely used in patients with affective disorders. As far as their effects on the immune system are concerned, a few studies have been carried out until now. Diazepam is inhibitory in vitro for the phagocytic functions and the antibody synthesis, being its action mediated via specific receptors on immunocompetent cells. On the contrary, alprazolam results to be enhancing for the antibacterial activity exerted by normal human peripheral blood T lymphocytes in vitro. Taken together, these data point out the different role which BDZ play on the immune response.

Role of thymic hormones in neuroimmunomodulation. Their use in patients with phobic disorders

Many evidences support the existence of a bilateral connection between the thymic gland and the hypothalamic-pituitary-adrenal axis (HPAA). In this respect, neurohormones such as the adrenal corticotropin hormone and glucocorticoids cause thymic involution, while the growth hormone and the prolactin upregulate thymic functions. On the other hand, a thymic hormone, the thymosin fraction 5, activates the HPAA, thus closing-up the regulatory loop between immune system and nervous system. In this review, a clinical trial with two thymic hormones (Timostimolina and Thymopentin) in agoraphobic patients with phagocytic dysfunctions is reported. Results obtained indicate that both substances lead to a partial and temporary immunological recovery, since a further depression of phagocytic activities occurs in coincidence with panic attack. The use of alternative immunomodulators in these patients is discussed.

Alprazolam enhances the antibacterial activity exerted by normal human peripheral blood lymphocytes

The effects of two benzodiazepines, diazepam and alprazolam, have been evaluated on the in vitro antibacterial activity exerted by human peripheral blood lymphocytes (PBL). Results demonstrate that diazepam has no influence on this PBL function, while alprazolam is able to enhance this activity in six out of nine normal donors considered. The possible therapeutical implications of these data are discussed.