Neonatal mouse immunity against group B streptococcal infection by maternal vaccination with recombinant anti-idiotypes

We investigated whether immunization with recombinant anti-idiotypic antibody fragments mimicking the conformation of the capsular antigen can protect against infection by group B streptococcus, an important neonatal pathogen. Single-chain fragment-variable anti-idiotypes competed with the type III carbohydrate for binding to type-specific antibodies and elicited, in mice, the production of protective immunoglobulins reacting against the type III polysaccharide. Moreover, maternal immunization with soluble or phage-displayed fragments protected neonatal mice against streptococcal infection. These data indicate that recombinant anti-idiotypic antibodies may be useful in developing protein images of relevant carbohydrate epitopes and, ultimately, in preventing infections by encapsulated bacteria.

Evaluation of the information processing and mood effects of a transdermal nicotine patch

The purpose of this study was to determine whether a transdermal nicotine patch will produce the same effects on performance and mood as cigarette smoking. The nicotine patch improved attentional processing and produced some improvements in memory. It produced the calming effects of smoking and induced feelings of happiness which were increased with smoking. These effects were obtained 6 h after application of the patch, showing that acute tolerance for these behavioural effects had not developed completely, if at all, after exposure to nicotine, although it is still possible that tolerance might occur with longer exposure.

Soluble antigens from group B streptococci induce cytokine production in human blood cultures

Group B streptococcal antigens stimulated tumor necrosis factor alpha (TNF-alpha), interleukin-1 (IL-1), and IL-6 production in human blood cultures in a concentration- and time-dependent fashion. The minimal concentrations of type-specific polysaccharides, lipoteichoic acid, and group-specific polysaccharide required to produce these effects were, respectively, 0.01, 1, and 10 microg/ml. Cell separation experiments indicated that monocytes were the cell type mainly responsible for cytokine production. Time course studies indicated that TNF-alpha was released before the other cytokines. TNF-alpha, however, did not appear to directly induce IL-1beta, as shown by blockade experiments with anti-TNF-alpha antibodies. IL-6 levels were moderately but significantly decreased by anti-TNF-alpha. These data indicate that several products from group B streptococci are able to directly stimulate human monocytes to release TNF-alpha, IL-1beta, and IL-6. These findings may be clinically relevant, since proinflammatory cytokines can mediate pathophysiologic changes during sepsis.

Role of interleukin 12 in experimental neonatal sepsis caused by group B streptococci

Cytokines are suspected to play an important role in systemic infections by group B streptococci (GBS), an important cause of neonatal sepsis. This work was undertaken to determine if interleukin 12 (IL-12) is produced in mouse pups infected with GBS and has a role in this sepsis model. IL-12 elevations were measured by both an enzyme-linked immunosorbent assay and a bioassay in plasma samples obtained from 12 to 72 h after GBS challenge. Pretreatment with neutralizing anti-IL-12 antibodies significantly increased lethality and blood CFU (P < 0.05). Conversely, either prophylactically or therapeutically administered recombinant IL-12 (rIL-12) significantly improved survival time and decreased blood CFU. Since these beneficial effects were associated with increased spleen gamma interferon (IFN-gamma) production, we examined whether the latter cytokine mediated the observed rIL-12 effects. Pretreatment with neutralizing anti-IFN-gamma monoclonal antibodies significantly counteracted the beneficial effects of rIL-12 on lethality. Our data indicate that rIL-12 is a possible candidate for treatment of GBS sepsis and that its activities in this model are at least partially mediated by IFN-gamma.

Endotoxin-induced lethality in neonatal mice is counteracted by interleukin-10 (IL-10) and exacerbated by anti-IL-10

The lethal effects occurring in neonatal (<24-h-old) BALB/c mice after challenge with 25 mg of lipopolysaccharide (LPS) per kg of body weight were significantly counteracted by pretreatment with recombinant interleukin-10 (rIL-10; 25 or 50 ng/mouse). Concordantly, blockage of endogenous IL-10 with the SXC1 monoclonal antibody increased LPS-induced mortality. Both IL-10 and SXC1 modulated the release of tumor necrosis factor alpha (TNF-alpha) so that, relative to controls, peak TNF-alpha values after LPS challenge were decreased by rIL-10 and increased by anti-IL-10.

Neonatal hypersusceptibility to endotoxin correlates with increased tumor necrosis factor production in mice

Septic shock is a major cause of mortality in neonates. The hypothesis was tested that neonatal age is associated with altered sensitivity to shock-inducing bacterial products or proinflammatory cytokines (or both). Mice of different ages were inoculated with various doses of lipopolysaccharide (LPS), superantigenic staphylococcal enterotoxin B (SEB), or recombinant tumor necrosis factor-alpha (rTNF-alpha), alone or in combination with the sensitizing agent D-galactosamine. Neonatal mice were markedly more susceptible to LPS-induced lethality but more resistant to SEB than were adults (P < .05). Mice of different ages did not differ, however, in their sensitivity to lethal activities of rTNF-alpha. Neonatal susceptibility to LPS and SEB correlated directly with plasma TNF-alpha but not IFN-gamma levels, which was confirmed by TNF-alpha and IFN-gamma blockade experiments. These data document marked age-related differences in the pathophysiology of septic shock and suggest that IFN-gamma is not an obligatory mediator of either LPS- or SEB-induced lethality in neonates.

Prevention of endotoxin-induced lethality in neonatal mice by interleukin-13

Interleukin(IL)-13, a cytokine produced by T helper 2 (Th2) cells, is a powerful inhibitor of macrophage functions, including surface expression of CD14 and production of IL-1 and tumor necrosis factor (TNF)-alpha. We tested the effects of recombinant mouse(m)IL-13 in a neonatal mouse model of endotoxin shock; this is a macrophage-dependent condition, which is a model of neonatal sepsis in humans. mIL-13 (0.5 microgram/mouse) dramatically reduced the lethal effects of lipopolysaccharide (LPS) if administered either 24 or 4 h prior to or concomitantly with LPS challenge. This action might be mediated by multiple modulatory activities of IL-13 on LPS-induced cytokine secretion since, relative to control animals, the mice treated with mIL-13 had eight times lower peak blood levels of TNF. The IL-1 beta levels were also decreased, whereas increased levels of IL-6 and IL-10 were observed at several time points after LPS challenge.

Porins of Pseudomonas aeruginosa induce release of tumor necrosis factor alpha and interleukin-6 by human leukocytes

The aim of this study was to examine the ability of Pseudomonas aeruginosa components to induce release of cytokines from human leukocytes. Human whole-blood cultures were incubated with several concentrations of purified P. aeruginosa products, including porins, exomucopolysaccharide, lipopolysaccharide, and toxin A. Supernatants were assayed for tumor necrosis factor alpha (TNF-alpha) and interleukin-6 (IL-6) activities. All of the P. aeruginosa components except toxin A were able to stimulate the release of both cytokines. On a weight basis, porins were as effective as lipopolysaccharide and significantly more effective than exomucopolysaccharide in inducing IL-6 release (P < 0.05). Moreover, porins were more potent than either exomucopolysaccharide or lipopolysaccharide in inducing TNF-alpha release (P < 0.05). Further experiments using isolated leukocytes suggested that monocytes were the cell population predominantly responsible for the production of both cytokines. These data indicate that P. aeruginosa porins are able to induce significant cytokine production. These components may be responsible for the chronically overactive inflammatory response associated with persistent lung infection in cystic fibrosis patients.

Interleukin 6 in neonates with early and late onset infection

OBJECTIVE

To assess the utility of determining interleukin 6 (IL-6) concentrations for diagnosing early (< or = 48 h of life) and late onset infection in a neonatal intensive care setting.

METHODS

We measured serum IL-6 values in five groups of neonates on both postnatal Days 1 and 2 (early sampling): Group 1, patients with clinical and microbiologic evidence of early onset infection; Group 2, patients with negative body fluid cultures but strong evidence of infection (clinical septicemia); Group 3, patients without clinical and microbiologic evidence of infection; Group 4, patients in whom infection could be neither confirmed nor excluded; and Group 5, healthy neonates with a normal postnatal course. We also measured IL-6 values in older neonates who during their hospital stay developed systemic infection (late sampling). Three controls matched for duration of hospital stay and birth date were chosen for each patient.

RESULTS

On postnatal Day 1 IL-6 values were elevated in all four patient groups compared with those in healthy neonates (P < 0.05 by analysis of variance (ANOVA)). There were no significant differences found among patient groups. On postnatal Day 2 IL-6 concentrations were persistently elevated in Groups 1 and 2 compared with values from those in Group 3, Group 4 and healthy controls (P < 0.01). At this time no significant differences in IL-6 values were found between uninfected symptomatic patients (Group 3), patients with uncertain findings (Group 4) and healthy controls. IL-6 concentrations were significantly higher in patients with late onset infection at presentation than in the patient controls (P < 0.0001) and returned to low values in those who recovered from infection.

CONCLUSIONS

There are differences in the serum concentrations of IL-6 that can be helpful in detecting early and late onset infection in preterm and term neonates. During the first 48 h of life serial IL-6 determinations are necessary so as not to overdiagnose infection in a neonatal intensive care setting.

[Non-Hodgkin's lymphoma of the spleen and hepatitis C. Report of a clinical case]

We report a clinical case of a patient affected by splenic non-Hodgkin lymphoma and virus C hepatitis. It seems that this kind of association is original because as far as we know the association between non-Hodgkin lymphoma and HCV did not include non-Hodgkin lymphoma involving the spleen. Indeed, in our patient, there was an increase of CD/57 lymphocytes. In our opinion this could be interesting in the disorders of the immune system associated with lymphoma.

Tumor necrosis factor-inducing activities of Cryptococcus neoformans components

Cryptococcus neoformans-induced tumor necrosis factor alpha (TNF-alpha) production may lead to increased human immunodeficiency virus replication in patients with AIDS. In order to identify cryptococcal components that are predominantly responsible for stimulating TNF production, various concentrations of glucuronoxylomannan (GXM), galactoxylomannan (GalXM), mannoproteins (MP), and alpha(1-3) [corrected] glucan were added to whole-blood cultures. All of the cryptococcal components tested, as well as whole heat-killed cryptococci, were capable of inducing TNF-alpha release in a dose-dependent manner. MP were significantly more potent than any of the other cryptococcal components tested or heat-killed cryptococci in stimulating TNF-alpha production (P < 0.05). GXM, in contrast, was significantly less potent in this activity than either GalXM or MP (P < 0.05). As little as 0.5 microg of MP per ml was sufficient to produce moderate but significant elevations of TNF-alpha release. Maximal MP-induced TNF-alpha levels were similar to those induced by Salmonella enteritidis lipopolysaccharide, our positive control. Further experiments using isolated leukocytes suggested that monocytes were the cell population mainly responsible for TNF-alpha production, although the participation of other cell types could not be excluded. The presence of complement-sufficient plasma was a necessary requirement for TNF-alpha induction by GXM, GalXM, and low doses of MP. High MP concentrations (100 microg/ml) were also capable of stimulating TNF-alpha production in the absence of plasma. These data indicate that soluble products released by C. neoformans are capable of inducing TNF-alpha secretion in human leukocytes. This may be clinically relevant, since high concentrations of such products are frequently found in the body fluids of AIDS patients infected with C. neoformans.

[Rendu-Osler-Weber disease. Report of a clinical case]

Rendu-Osler-Weber disease is an hereditary disorder characterized by cutaneo-mucous telangiectasis and vascular abnormalities in several organs. Bleeding, especially epistaxis, represents the most important clinical feature. Pulmonary arteriovenous fistulae can cause hypoxaemia, haemoptysis, polycythaemia and clubbing. Diagnosis is based on family and personal history, teleangiectasis, laboratory (haemochrome, fibrinogen, PT, PTT) and instrumental findings (endoscopy and/or roentgen). Therapy depends on symptoms. Embolization of pulmonary arteriovenous fistulae and laser treatment of intestinal vascular abnormalities have been successful. Danazol treatment yielded controversial results. We report the case of a patient admitted for arterial hypertension and recurrent epistaxis. Rendu-Osler-Weber disease diagnosis was made based on positivity at family and personal history, clinical examination, laboratory and instrumental findings. In conclusion we underline the pivotal role of anamnesis and clinical examination in the differential diagnosis of hereditary bleeding disorders and emphasize the importance of early diagnosis for the correct therapeutic approach.

[Clinical onset of brain metastasis: ictus. Report of a case]

We present a clinical case in which a patient with a brain metastasis had a clinical onset simulating a stroke. Computerized tomography showed a lesion which was diagnosed as ischaemic, whereas magnetic resonance imaging showed an expansive lesion surrounded by an aedematous region of probable neoplastic nature. Indeed histology confirmed the neoplastic origin of the lesion. This kind of presentation is very uncommon but when an hypodense area is detected on CT scan one should always think to this occurrence. Neuroradiology is often necessary for a correct diagnosis. CT scan might usefully be integrated by MRI to distinguish between stroke and brain neoplasty.

Role of gamma interferon in a neonatal mouse model of group B streptococcal disease

The aim of this study was to assess the role of gamma interferon (IFN-gamma) in a neonatal mouse model of group B streptococcal (GBS) sepsis. IFN-gamma was produced by spleen cells at 24, 48, and 72 h after GBS challenge. Treatment with anti-IFN-gamma at 6 h before challenge totally abrogated the IFN-gamma response but did not affect survival. Subcutaneous administration of recombinant IFN-gamma (2,500 IU per pup) at 18 h after challenge resulted in increased survival time and reduced blood colony counts at 48 and 72 h. In vitro preincubation of neonatal whole blood with IFN-gamma before the addition of GBS resulted in significant restriction of bacterial growth. These data indicate that administration of recombinant IFN-gamma can partially restore impaired host defenses against GBS in neonatal mice. This cytokine may be useful for the treatment of neonatal infections.

Interleukin-10 protects neonatal mice from lethal group B streptococcal infection

We investigated the role of interleukin-10 (IL-10) in a neonatal mouse model of lethal group B streptococci (GBS) sepsis. Plasma IL-10 levels significantly increased at 24 and 48 h after GBS inoculation. Neutralization of IL-10 with specific antibodies had no effect on lethality. Administration of recombinant IL-10 at 20 or 4 h before challenge, but not at later times, resulted in decreased tumor necrosis factor alpha levels and improved survival. IL-10 could be potentially useful for the treatment of GBS sepsis.

Improved survival and antagonistic effect of sodium fusidate on tumor necrosis factor alpha in a neonatal mouse model of endotoxin shock

Unlike the antibiotics erythromycin and penicillin G, sodium fusidate (fusidin) pretreatment (80 mg/kg of body weight) increased the survival rate of neonatal BALB/c mice challenged with Salmonella enteritidis lipopolysaccharide. Fusidin also significantly reduced the plasma tumor necrosis factor alpha levels. Hence, fusidin may prove useful in the management of bacterial sepsis in humans.

Immunobiological activities of mould products: functional impairment of human monocytes exposed to aflatoxin B1

In order to elucidate the effects upon the human immune system of aflatoxin B1 produced by the food-contaminating mould Aspergillus flavus, phagocytosis, microbicidal activity, superoxide production and intrinsic antiviral activity were studied in monocytes exposed to aflatoxin B1 for different times at concentrations ranging from 0.1 to 1 pg/ml. Phagocytosis and microbicidal activity were significantly impaired (p < 0.05) by aflatoxin B1 at doses as low as 0.1 pg/ml. However, pretreatment of monocytes with aflatoxin B1 did not modify intrinsic antiviral activity or superoxide production. These results confirmed data obtained from animals fed with mycotoxin-contaminated foods. The potential danger to human health of exposure to mycotoxins demonstrates the necessity for careful microbiological control of food.

Occupational dermatitis in shoemakers

In an epidemiological study of occupational dermatitis in 5 different shoe factories, 246 workers were interviewed, examined and patch tested using standard and occupational patch test series. The prevalence of occupational contact dermatitis was 14.6% (36/246): 8.1% (20/246) irritant contact dermatitis (OICD) and 6.5% (16/246) allergic contact dermatitis (OACD). Among the latter, the most common occupational allergens were p-tert-butylphenol-formaldehyde resin and mercaptobenzothiazole. 6% (15/246) presented with hyperkeratosis of the fingertips, while 3.2% (8/246) reported pruritus sine materia (PSM) present only during working hours. 2 workers presented with vitiligo-like leukodermic patches on the backs of their hands and on their forearms. Some jobs were more frequently associated with skin complaints. In the assembly department, OACD was most frequent (11.4%), attributed to contact with adhesives and, to a lesser degree, with rubber and leather. OICD caused by contact with the solvents contained in adhesives and varnishes was most frequent in the assembly and trimming departments (17.1% and 15.6%, respectively). PSM, probably caused by the dust present in the working environment was reported by 33.3% of the workers in the sole-cutting and scraping departments. Hyperkeratosis of the fingertips, as a reaction to the continuous trauma of leather on the skin, was observed most frequently (41.6%) in the sole-cutting department.

'Normolipidemic' tendinous and tuberous xanthomatosis

BACKGROUND

Multiple tendinous and tuberous xanthomas are characteristically associated with hyperlipidemic states. However, normolipidemic tendinous and tuberous xanthomas have been reported in the literature, with normal levels of cholesterol, cholestanol and plant sterols.

OBJECTIVE AND METHOD

To delineate the disorder and to suggest its likely origin, a case of apparently normolipidemic severe tuberous and tendinous xanthomatosis was studied. Several lipoprotein and lipid analyses, clinical tests and histological studies were performed over a period of 5 years in the propositus and his family.

RESULTS

At the first lipid analysis, no quantitative or qualitative alterations of the lipoprotein fractions or of the apoproteins AI, B, CII, CIII, E were detected in the propositus and xanthomatosis was classified as normolipidemic. During the follow-up, the patient showed a nonconstant hypertriglyceridemia and/or hypercholesterolemia associated with the presence of small and dense VLDL and LDL. An increase in apo-B was observed. There was an unusual quantity of conjugated dienes of arachidonic acid in the plasma and in the LDLs of the patient, present only in small traces in the control population. The family study and the long follow-up of the lipid analysis of the propositus were compatible with the diagnosis of familial combined hyperlipidemia.

CONCLUSION

Our data highlight the importance of a critical review of studies regarding normolipidemic xanthomatosis, since only after an extensive follow-up and sequential analyses of lipoprotein fractions is it possible to exclude the presence of time variables and complex lipoprotein abnormalities.

Survival after AIDS among Italian haemophiliacs with HIV infection. The Italian Group on Congenital Coagulopathies

OBJECTIVES

To estimate survival trends for persons with haemophilia and HIV/AIDS.

DESIGN AND METHODS

Survival analysis conducted among the cohort of HIV-positive haemophiliacs with AIDS at the Italian Haemophilia Registry. Kaplan-Meier method was used to estimate survival times, stratifying for demographic and clinical covariates. Cox proportional hazards model was applied in order to identify factors independently associated with survival.

RESULTS

Median survival from the first AIDS diagnosis to death was estimated to be 17.0 months for 176 individuals with AIDS. Median survival after AIDS diagnosis increased from 12.0 months in December 1983-December 1988 to 17.0 months in January 1989-May 1990 and to 25.0 months in June 1990-December 1991. Median survival times were significantly (P < 0.001) lower for individuals diagnosed with non-infective AIDS indicator diseases (lymphoma, AIDS-associated neurological disease, Kaposi's sarcoma, wasting syndrome: 4.0 months), in comparison with haemophiliacs diagnosed with Pneumocystis carinii pneumonia (PCP; 18.0 months) or other infections (35.0 months). Antiretroviral treatment after AIDS diagnosis was associated with a longer survival than that estimated for individuals with no treatment after AIDS; the same was true for PCP prophylaxis. Younger age at HIV seroconversion and at AIDS diagnosis were associated with a longer survival. Multivariate analysis showed that factors independently associated with survival were type of AIDS indicator disease and antiretroviral administration after AIDS diagnosis.

CONCLUSIONS

This study indicates an increasing survival from AIDS diagnosis to death over time, also as a result of the introduction of antiretroviral therapy. Survival trends are similar to those reported among homosexual men and intravenous drug users with AIDS, suggesting a similar access to the health-care system for individuals with AIDS. Survival studies may improve our understanding of the natural history of HIV infection and may indicate the impact of preventive measures.