Interferon-gamma levels in serum and bronchoalveolar lavage fluid of mice infected with Bordetella pertussis

The adherence of Bordetella pertussis to respiratory cilia and its survival in neutrophils and macrophages is crucial to the pathogenesis of whooping cough. To investigate the role of endogenous interferon (IFN)-gamma in acute infection, levels of IFN-gamma in bronchoalveolar lavage (BAL) fluid of mice infected intranasally with B. pertussis were determined. Since pertussis toxin is released during infection by B. pertussis either locally or systemically, serum levels of IFN-gamma in mice injected intravenously with pertussis toxin were also determined. A persistent and significant increase of IFN-gamma levels with concomitant peripheral blood lymphocytosis was observed after 5 and 10 days. The results of this study showed an early but transitory production of endogenous IFN-gamma in BAL fluid of mice infected with B. pertussis.

Analysis of T-lymphocyte subsets after phytohemagglutinin stimulation in normal and type 1 diabetic mothers and their infants

PROBLEM

Our aim was to investigate the immunological status of diabetic pregnancy, which is an overlap of diabetic immunity abnormalities and the immunological modifications normally occurring during pregnancy.

METHOD

We studied lymphocyte subpopulations and lymphokine production, after 96 h of phytohemagglutinin (PHA) stimulation, from normal and Type I diabetic pregnant women at delivery time and from the respective cord blood.

RESULTS

Peripheral blood mononuclear cells (PBMC) from both normal and Type I diabetic mothers showed an increase in CD8+ and a decrease in CD4+ cells compared to the respective cord blood mononuclear cells (CBMC). Moreover, Type I PBMC showed a lower number of "activated" CD3+ DR+ cells and a higher number of CD8+ CD25+ cells with respect to normal women, which may reflect the dysregulatory pattern due to the autoimmune condition. Type I CBMC showed a big increase in the number of CD4+ Leu8+ cells, a cell subpopulation characterized by inhibitory activity. Finally, as regards lymphokine release in culture supernatants, type I diabetes seemed to be associated with an over-production of IL1 and IL6, although the latter increase is less evident in CBMC cultures.

CONCLUSIONS

The present study shows that diabetic pregnancy is associated with major alterations of cell-mediated immunity leading to a state of immunodepression. Moreover, our study suggests that the maternal immunological status influences fetal immunity, as demonstrated by the increase in the number of regulatory cells and by the altered pattern of lymphokine production (IL1 and IL6) by lymphocytes derived from diabetic CBMC. The latter phenomenon perfectly mirrors maternal PBMC characteristics.

No independent association between HSP70 gene polymorphism and IDDM

A role for heat shock proteins (HSPs) in autoimmunity has recently been suggested by several authors. Autoantibodies against HSPs have been associated with such autoimmune diseases as systemic lupus erythematosus, polymyositis, and the NOD mouse model of diabetes. Moreover, genes for the major 70,000-M(r) HSP (HSP70) are located within the MHC. To investigate a potential association of an HSP70-2 gene polymorphism with insulin-dependent diabetes mellitus (IDDM), we analyzed restriction-fragment-length polymorphism (RFLP) of this gene in 29 families with one or more member affected by IDDM. With the enzyme PstI, as reported previously, two HSP70-2 alleles of 8.5- and 9.0-kb were found. The 8.5-kb allele was found more frequently on diabetic haplotypes compared with control haplotypes (41 of 66 [62%] vs. 20 of 46 [43%], P = 0.03). This association was due to the conservation of alleles on extended haplotypes we previously reported to be associated with diabetes on initial analysis of families. Twenty-three of 26 diabetic DR3 haplotypes and 3 of 3 normal DR3 haplotypes and all instances of [HLA-B8, SC01, DR3] and [HLA-B18, F1C30, DR3] had the 8.5-kb allele, whereas 0 of 9 normal DR2 haplotypes and 0 of 2 diabetic DR2 haplotypes had the 8.5-kb allele (P = 8 x 10(-7) DR3 vs. DR2 haplotypes). The alleles were equally distributed among DR4 haplotypes.(ABSTRACT TRUNCATED AT 250 WORDS)

An AIDS model with distributed incubation and variable infectiousness: applications to i.v. drug users in Latium, Italy

An AIDS model with distributed incubation and variable infectiousness is considered and simulated via a second-order numerical method. The method is applied to the HIV epidemic among IV drug users in the Latium region of Italy, using available data on the length of the incubation period before the onset of AIDS, on the infectivity of infected individuals during that period, and on the demography of drug users. The contact rate is adjusted to match the actual number of AIDS cases. The sensitivity of the model to uncertainties in the parameters is finally investigated, by performing several simulations.

Insulin autoimmunity: the rate limiting factor in pre-type I diabetes

Type I diabetes is preceded by a series of autoantibodies including recently recognized subtypes of cytoplasmic islet cell antibodies (ICA) which we have termed 'restricted' and 'non-restricted'. Amongst the autoantibodies detected in prediabetics the antibodies to insulin are unique in that their levels correlate with the rate of progression to type I diabetes. The levels of insulin autoantibodies appear to be stably regulated prior to the appearance of ICA and the highest levels are associated with expression of DR4. The above studies have led to the hypothesis that an immune response to insulin is an early and central feature of anti-islet autoimmunity and that such as immune response when associated with loss of tolerance to other islet antigens (e.g. ICA) is pathogenic.

Prognostically significant heterogeneity of cytoplasmic islet cell antibodies in relatives of patients with type I diabetes

A significant proportion of relatives of patients with insulin-dependent (type I) diabetes with high titers of cytoplasmic islet cell autoantibodies (ICAs) do not progress to overt diabetes with up to 8 yr of follow-up. This may reflect that follow-up of such relatives has not been long enough to observe diabetes, that despite expression of identical ICAs, some relatives will not progress to diabetes; or that there is heterogeneity in what is identified as ICA. We identified a subset of ICA that was restricted in its species (not reacting with mouse islets) and cell-type reactivity within islets (beta-cell specific). Only one of eight relatives whose sera had the restricted pattern of reactivity progressed to overt diabetes, and on sequential evaluation, all but the one relative who progressed to diabetes have maintained normal first-phase insulin secretion to intravenous glucose. In contrast, by life-table analysis, 70% of relatives expressing nonrestricted ICA became diabetic within 5 yr of follow-up (1 of 8 vs. 16 of 25 diabetic at last follow-up, P less than 0.02). Moreover, preliminary data suggest a significant association of the human leukocyte antigen DQB1*0602 allele of DR2 haplotypes with the restricted ICA pattern (4 of 5 DQB1*0602 restricted vs. 0 nonrestricted ICA, P = 0.006). We propose that expression of a genetically determined restricted ICA pattern confers a markedly lower risk for progression to diabetes.(ABSTRACT TRUNCATED AT 250 WORDS)

Contact matrices for multipopulation epidemic models: how to build a consistent matrix close to data

In models of the dynamics of sexually transmitted diseases between and within N interacting populations, it is necessary to specify the matrix of contacts between populations. Mixing matrices have to satisfy a consistency condition that generally will not be satisfied by empirically obtained matrices. The problem of inferring a mixing matrix from data is phrased here as the problem of finding a matrix in a prescribed set that minimizes an opportune distance from the matrix of data. Two different distances that attempt to measure relative errors are suggested. When no constraints are posed on the activity rates of the populations, the author shows that the minimum distance from data is attained at Knox's (1986) matrix. When activity rates are to be preserved, the minimum cannot be found explicitly for N greater than 2. An algorithm proposed by Arcà, Perucci, Spadea, and Rossi (1990) is then investigated, and shown always to converge to a consistent matrix. Through several examples, it is shown that this limiting matrix does not minimize distance from data, but is generally close to the minimum. Finally, the author simulated the collection of data with sampling errors and possible bias and evaluated the performance of this algorithm in approximating the 'true' contact matrix starting from the simulated 'data' matrix.

Spontaneous release of interferon as a predictor of clinical evolution in HIV-positive subjects

In order to establish a correlation with disease progression we prospectively evaluated ten clinical and immunologic parameters in 102 consecutive HIV-positive subjects. The eight immunologic variables were: in vitro spontaneous interferon release by peripheral blood monocytic cells, alpha- and gamma-interferon production induced by Newcastle Disease Virus and PHA, Multitest Mérieux score, PHA- and CON-A-induced lymphocyte transformation, absolute number of CD4+ cells and CD4/CD8 ratio, respectively. The two baseline clinical variables were risk factor and disease presentation. Generalized Wilcoxon analysis indicated a significant correlation of one clinical (disease presentation at entry) and three immunologic variables (spontaneous interferon release, CD4+ cell number, Multitest Mérieux) with disease progression. Baseline spontaneous release of alpha, acid-labile interferon showed the best correlation with disease progression, and appeared to be significantly associated with CD4+ cell loss. Spontaneous release of acid-labile alpha interferon by mononuclear cells in vitro could be highly predictive of disease evolution in HIV-Ab positive, AIDS-free subjects.

[The treatment of bacterial infections of the lower respiratory tract in childhood. An open comparative study of sulbactam/ampicillin vs. ceftazidime]

Sixty children suffering from lower respiratory tract infections have been included into this study, respectively 30 (18 M + 12 F) in the sulbactam/ampicillin (S/A) group and 30 (20 M + 10 F) in the ceftazidime (CFT) group. Average age was 42.9 months +/- 34.4 in S/A group (range 6-120) and 48.7 +/- 42.1 (range 6-144) in CFT group. Both groups were similar as to sex, age, type and duration of the infection. Posology was 150 mg/kg/die for S/A and 50 mg/kg/die for CFT. The duration of treatment was 7.2 days +/- 2.2 (range 5-12) for S/A group and 6.4 days +/- 1.6 (range 5-12) for CFT group. At the end of the therapy clinical recovery has been obtained in all cases. A rapid defervescence and remission of symptoms at an identical rate has been recorded in both treatment groups. General and local tolerability was excellent in both treatment groups.

Effects of recombinant human interleukin-1 beta on accumulation of inflammatory peritoneal macrophages in mice treated with pertussis toxin

In this study we report that treatment with recombinant human interleukin-1 beta (rIL-1 beta) (10 U per mouse, intraperitoneally) significantly increased the number of inflammatory macrophages in the peritoneal cavity of mice treated with pertussis toxin (PT) (1 micrograms per mouse, intravenously). The administration of rIL-1 beta in a single intraperitoneal dose (10 U per mouse) 1 or 2 days before challenge with PT did not prevent the decrease in the number of inflammatory macrophages in the peritoneal cavity of mice. On the other hand, the simultaneous administration of rIL-1 beta and PT, as well as the administration of rIL-1 beta 24 h after injection of PT, significantly counteracted the inhibitory effect of PT on inflammatory peritoneal macrophages.

Serum reactivity against RINm5F purified membrane antigens (ICMA) in newly diagnosed diabetic subjects

A simple and rapid enzyme-linked immunosorbent assay (ELISA) for the detection of islet cell membrane antibodies (ICMA) in the sera of IDDM has been recently established. This new method has been made possible by using affinity purified islet cell membrane antigens from a monoclonal insulin secreting cell line obtained from a transplantable rat insulinoma (RINm5F). One hundred and thirty-three sera of newly diagnosed diabetic patients (duration of symptoms of less than 3 months) were tested, and ICMA positivity was found in 21% of patients. In the same group we found 64% ICA positive subjects, but no correlation has been found between ICA and ICMA. Therefore these two auto-antibodies should be considered as expression of different steps of the autoimmune beta-cell damage. In this light ICMA could represent a very early marker of autoimmune process and it could be useful to recognize, among risk subjects, those who are developing IDDM.

Early administration of an immunomodulator and induction of remission in insulin-dependent diabetes mellitus

A clinical trial was undertaken to determine whether intensive thymopentin administration enhances remission of insulin-dependent diabetes (IDDM) during the first year after diagnosis. Dosage with insulin was minimized with target control of blood glucose levels less than or equal to 7.8 mmol/l before meals. Remission was defined as a prolonged period after IDDM onset (not less than 3 months) characterized by a non-insulin-receiving (NIR) state in which target metabolic control was reached without administration of insulin and with a valid C-peptide response, evaluated after standard breakfast. Sixteen IDDM patients aged 12-31 years, recruited within 2 weeks of initiation of insulin therapy and within 5 weeks of onset of symptoms, were treated with intravenous (i.v.) thymopoietin32-36 pentapeptide (Thy) (1 mg/kg/body weight) for 7 days and twice per week for up to 3 months. A control IDDM group without initial significant differences in metabolic control parameters was also studied. No difference was observed between the two IDDM groups regarding the after-diagnosis normalization curve of HbA1c; mean daily glycemic level rates and ICA titer decreased during the observation. A reduction in anti-insulin antibodies (AIA) in Thy-treated patients was observed in comparison to conventionally treated IDDM starting from 6 months and reaching a reduction peak at 1 year (P less than or equal to 0.02). As regards the NIR remission rate, it was significantly more accelerated in Thy-treated patients, reaching 43% at 6 months and 57% at 1 year vs 12% and 6.7% respectively in the control IDDM group (P range less than or equal to 0.05-0.02).(ABSTRACT TRUNCATED AT 250 WORDS)

The influence of high dose intravenous immunoglobulins on immunological and metabolic pattern in newly diagnosed type I diabetic patients

In autoimmune disease the functional deficiency of T suppressor cells, also described in Type I diabetes, may be restored through immunoglobulin (Ig) infusion, which increases antigen phagocytosis, NK activity, cell clones and antibody anti-idiotype responses. Sixteen Type I diabetic patients were studied: eight were treated soon after the initial correction of disease-onset glycemic deterioration with intensive intravenous (i.v.) 7S Ig treatment (0.4 g/kg/BW) for 1 week and once per week for 6 months, whilst the remaining patients constituted the control group. All patients were evaluated during the study for metabolic and immunological parameters. A reduction in insulin requirement compared to conventionally treated patients was observed at the third (0.17 +/- 0.06 vs 0.44 +/- 0.08 IU/kg/BW; P less than 0.02) and at the sixth month of therapy (0.19 +/- 0.07 vs 0.54 +/- 0.07 IU/kg/BW; P less than 0.005). Two patients ceased to require insulin therapy within the BW; P less than 0.005). Two patients ceased to require insulin therapy within the first month, showing a prolonged restoration of B-cell function. Serum C-peptide values were also significantly higher in the Ig-treated group compared to the control group after 3 and 6 months. As regards immunological parameters, patients showed a decrease in insulin antibody levels and a reduction in TAC+ cells. Intravenous Ig therapy seems able to affect positively the first phases of metabolic and immunological deterioration of Type I diabetes.

Effects of ofloxacin on cell-mediated immune response and lymphokine production

The effects of orally administered ofloxacin on functional parameters of cell-mediated immunity were investigated in 15 patients with respiratory or urinary tract infections. Mononuclear leucocytes were obtained before administering the drug, 1 h after the first dose, and five days later. The cells were stimulated with lectins, tetanus toxoid and Newcastle Disease virus in order to assess mitogen- and antigen-induced lymphocyte proliferation and production of gamma-interferon, interleukin-2 and alpha-interferon. An increase in proliferative response to pokeweed mitogen and a slight but significant decrease in alpha-interferon production were observed, while other parameters remained unaffected by treatment.

Chemotactic activity of pertussis toxin on murine lymphocytes. Its potential role on lymphocyte accumulation in the lung

The effects of pertussis toxin on lymphocyte migration were studied in vitro. In this study pertussis toxin significantly stimulated lymphocyte migration at concentrations of 0.1 and 1 microgram ml-1 using a microchamber and the leading-front method. Checkerboard analysis demonstrated that pertussis toxin causes directed migration of lymphocytes (chemotaxis). Heat-treatment pertussis toxin abolished its capacity to cause this migration. When murine lymphocytes were preincubated with different concentrations of pertussis toxin, an inhibition of chemotaxis at the dosages of 0.1 and 1 microgram ml-1 was observed. On the other hand, lymphocytes derived from mice treated with pertussis toxin were not inhibited after subsequent exposure to pertussis toxin in vitro. Since lymphocyte accumulation in the lungs of mice treated with pertussis toxin has been well demonstrated, the results of our study could suggest a chemotactic activity of pertussis toxin in determining accumulation of lymphocytes in this organ.

Population models for diseases with no recovery

An S----I epidemic model with a general shape of density-dependent mortality and incidence rate is studied. The asymptotic behaviour is global convergence to an endemic equilibrium, above a threshold, and to a disease-free equilibrium, below the threshold. The effect of vaccination is then examined.

[Agnathia, microstomia, synotia]

The authors describe a case of plurimalformative syndrome, characterized by agnathia, microstomia, synotia and by cardiac and pulmonary maldevelopment. The case peculiarity consist in the rarity of this malformative occurrence; moreover, the authors underline the occurrence of familiarity with Seckel's Syndrome.

[Inhibition of pancreatic beta-cell secretion during "glucose clamp" in patients with polycystic ovary syndrome]

Insulin-resistance is a well-known feature of polycystic ovary syndrome (PCOS) and the present paper investigates the comparative roles of the peripheral tissues and the pancreatic beta-cells in its pathogenesis. The study was conducted on 5 young women with PCOS, all of normal weight and glucose tolerance in whom the glucose-insulin clamp test had revealed reduced peripheral glucose uptake that was not influenced by other conditions typically associated with insulin-resistance. Beta-cell function was investigated in these patients and 5 healthy controls via the assessment of the efficiency of the insulin/insulin feedback which involved studying the suppression of plasma C peptide during the glucose clamp. The results suggested that the insulin/insulin beta-cell feedback mechanism had retained its efficiency despite proven peripheral insulin-resistance. These data do not therefore support the hypothesis advanced by others that there is some sort of beta-cell insulin resistance parallel to the insulin resistance of the peripheral tissues. On the basis of those results it is rather believed that in PCOS the insulin-resistance is generated peripherally while the insulin/insulin feedback in the beta-cell is unimpaired. This obliges us to rethink the role of the hyperinsulinism encountered in PCOS and suggests that the changed sensitivity of the peripheral tissues to insulin activity may constitute a primary event in the genesis of insulin-resistance. This type of behavior has been demonstrated in the obese and in people with acanthosis nigricans, all with normal glucose tolerance.(ABSTRACT TRUNCATED AT 250 WORDS)

[Inhibition of pancreatic beta-cell secretion during a "glucose-clamp" in subjects with acanthosis nigricans]

It has long been known that acanthosis nigricans is accompanied by insulin resistance. In certain insulin-resistant states, including obesity, a more sluggish response to the insulin/insulin inhibition feedback normally present in pancreatic beta cells has been documented. Some have claimed a sort of beta-cell insulin resistance "parallel" to that of the peripheral tissues. The present study assesses the efficiency of the insulin/insulin feedback in acanthosis nigricans patients, measuring the inhibition of the production of C-peptide (the indicator of beta cell secretion) induced by the administration of exogenous insulin during glucose clamping. This was done in order to compare the roles of the peripheral tissues and the beta cells in producing the insulin resistance typical of acanthosis nigricans. The study using the glucose-insulin clamp technique was conducted on 4 Acanthosis Nigricans patients with normal glucose tolerance and 4 healthy controls, the drop in C-peptide levels after the administration of exogenous insulin being assessed in the course of both steady states. The results showed that the acanthosis nigricans patients retained a beta cell response to the exogenous insulin through their peripheral tissues presented a reduced sensitivity to insulin as revealed by the glucose-insulin clamp. It therefore seems reasonable to attribute the endocrine metabolic alteration found in Acanthosis Nigricans to a peripheral receptor and/or post receptor alteration rather than central alterations in the beta cells that have yet to be demonstrated. It is concluded that in acanthosis nigricans the peripheral insulin resistance is primarily independent phenomenon and not "parallel" to insulin/insulin feedback.