Assessment of humoral and cell-mediated immunity against Bordetella pertussis in adolescent, adult, and senior subjects in Italy.

Humoral and cell-mediated immunity (CMI) against B. pertussis was assessed in a sample of adolescent, adult and senior subjects distributed in five different geographical areas in Italy. Most (99.1%) subjects had IgG anti-pertussis toxin (PT) antibodies exceeding the minimum detection level [> or = 2 ELISA units (EU)/ml]. There were no significant differences between the genders; 6.2% samples recorded titres > or = 100 EU/ml. CMI was positive [stimulation index (SI) > or = 5] against PT in 39.0% of all samples. This study suggests that B. pertussis continues to circulate in age groups that have been previously considered to be uninvolved in the circulation of this pathogen and that adolescent and adult pertussis boosters may be of value in these populations. Nevertheless, over the last 10 years, large increases in vaccination coverage rates have contributed to reduce the spread of the aetiological agent, especially in the immunized population.

In situ hybridization analysis of preprotachykinin-A mRNA levels in young and old rats.

Preprotachykinin-A (PPT-A) mRNA levels in discrete rat brain regions were examined. Analysis of silver grains revealed a 19.2% and 31.5% statistically significant decrease in PPT-A mRNA in the dorsal and ventral caudate putamen (d-CPu and v-CPu), respectively, a 30% lower expression of PPT-A mRNA in the bed nucleus of the stria terminalis (BNST), a 33.7% decrease in PPT-A mRNA in the habenula (Hb), and a 30% decrease of PPT-A mRNA levels in the posterodorsal part of the medial amygdala (MePD). Results show that aging of the CNS is associated with widespread changes in tachykinin gene expression, suggesting that alterations in the tachykinergic system may have implications in the physiopathology of the elderly.

Evidence of increased carriage of Corynebacterium spp. in healthy individuals with low antibody titres against diphtheria toxoid.

This study evaluated whether a correlation exists between carriage of corynebacteria and the lack of immunity to diphtheria toxoid. Samples of both nasal and pharyngeal secretions were taken from 500 apparently healthy subjects of both sexes and of all ages and inoculated onto Tinsdale's medium. A serum sample was also taken for ELISA test to determine the titre of diphtheria toxin antibodies. None of the subjects carried Corynebacterium diphtheriae. Ninety-three strains of Corynebacterium spp. were isolated from 93 subjects and 86 of these were classified to species or group level by biochemical tests. C. xerosis was the most common (25.8%) followed by C. pseudodiphthericum (16.1%), C. jeikeium and C. striatum (both 10.8%), and C. urealyticum (9.7%). Three other species accounted for approximately 20% of strains and seven were unclassified as biochemically atypical corynebacteria. Non-protective antibodies to diphtheria toxin were found in 80 of the 93 subjects and a strong statistical association was demonstrated between carriage of corynebacteria and non-protective levels of anti-toxin antibodies. The remaining 13 subjects had protective levels of antitoxin antibodies. In contrast, only 45 of the 407 non-colonized subjects had non-protective antitoxin titres. The prevalence of carriage increased with age among males as did the percentage of non-protected subjects. The prevalence of female carriers of corynebacteria was significantly lower. Serum samples from 12 subjects with different antibody titres to diphtheria toxoid reacted to varying degrees with whole-cell lysates of a number of species of corynebacteria. The results suggest that a causal relationship may exist between nasopharyngeal carriage of corynebacteria and a low anti-diphtheria toxin immune response.

A randomized, controlled study of thymosin-alpha1 therapy in patients with anti-HBe, HBV-DNA-positive chronic hepatitis B.

No consistently effective therapy is yet available for the treatment of chronic HBsAg, anti-HBe, HBV-DNA-positive hepatitis. A multicenter trial has shown that the response rates are not significantly different when patients with anti-HBe-positive hepatitis are treated with six-month course of thymosin-alpha1 or of interferon-alpha. However, since among these patients, interferon's real efficacy is still debated, with sustained biochemical response achieved in only a few of the treated patients, we conducted this controlled study to investigate the safety and efficacy of thymosin-alpha1 as compared with no treatment. Forty-four chronic hepatitis B virus (HBV) carriers, who were anti-HBe- and HBV-DNA-positive, were randomized, with stratification for the presence of cirrhosis at baseline liver biopsy, to receive either thymosin-alpha1 at a dose of 900 microg/m2 twice a week for six months or no treatment. At entry, both groups of patients were comparable for sex, age, liver histology, ALT, IgM anti-HBc, and HBV-DNA levels. Forty-two patients were followed-up for 20 months (median; range 12-32 months) after completion of therapy: one dropped out, and one developed hepatocellular carcinoma at six months. Thymosin-alpha1 treatment had no side effects. Six months after the end of the therapy, HBV-DNA was negative and ALT had normalized in 14% of treated cases and in 4.5% of control group, while IgM anti-HBc was negative (<0.200) in 14% of the treated patients and in 4.5% of the controls. Among the treated patients, the median ALT levels stayed significantly lower compared to the pretreatment values during the treatment period and six months of follow-up. During the first year, there were six flares of hepatitis in the control group and five among the treated patients (P = NS), yielding a per year average of 0.3 and 0.23 flares per patient, respectively. Among the treated patients, median IgM anti-HBc levels were low with respect to baseline values 4-10 months after treatment started. None became HBsAg negative. In conclusion, these results indicate that, in anti-HBe, HBV-DNA-positive chronic hepatitis B, thymosin-alpha1 therapy alone does not increase the response rate, but may contribute to reduce the immune-mediated liver cell necrosis as indirectly assessed by ALT and IgM anti-HBc levels.

Prevalence of diphtheria toxin antibodies in human sera from a cross-section of the Italian population.

A polycentric study was carried out between 1993 and 1995 in order to evaluate diphtheria immunity on a representative sample of population from different areas of Italy. To determine diphtheria antitoxin, sera from 5187 apparently healthy subjects, divided according to sex and age groups, were titrated using an ELISA indirect method. A basic protective titre of diphtheria antitoxin (> 0.01 IU ml-1) was found in 4080 (78.6%) subjects. No statistically significant differences between males and females were observed. Our findings show that the proportion of susceptibles increases with age and a high proportion of adults no longer has diphtheria antitoxin at protective levels since toxigenic C. diphtheriae circulation is presently lacking in Italy.

In situ hybridization analysis of preprotachykinin-A mRNA levels in young and old rats.

The present study examined the effects of ageing on preprotachykinin-A (PPT-A) mRNA levels in discrete regions of the rat brain. Semiquantitative analysis of silver grains revealed a 16% statistically significant decrease in PPT-A mRNA in the shell of the nucleus accumbens (AcbSh), a 27.6% statistically significant lower level of PPT-A mRNA in the olfactory tubercle (Tu), a 19.2% and 31. 5% statistically significant decrease in PPT-A mRNA in the dorsal and ventral caudate-putamen (d-CPu) (v-CPu), respectively, a 30% statistically significant lower expression of PPT-A mRNA in the bed nucleus of the stria terminalis (BNST), a 33.7% statistically significant decrease in PPT-A mRNA in the habenula (Hb) and a 30% statistically significant decrease of PPT-A mRNA levels in the postero-dorsal part of the medial amygdala (MePD). No changes in PPT-A mRNA levels were found in the nucleus accumbens, core (AcbC), in the islands of Calleja (Icj), and in the medial preoptic area (mPOA). These results show that ageing of the central nervous system (CNS) is associated with widespread changes in tachykinin gene expression, suggesting that alteration in the tachykinergic system may have implications in the physio-pathology of the elderly.

Immunity to diphtheria in Siena.

The aim of this study, carried out in 1993, was to evaluate diphtheria immunity in Siena. Diphtheria antitoxin levels were measured by means of the immunoenzymatic test (ELISA) in serum samples of 602 apparently healthy subjects (239 males and 363 females) of all ages residing in Siena. According to widely used criteria, 6% of the total population were susceptible to diphtheria (antibody levels < 0.01 IU/ml), 71% had basic protection (0.01-0.09 IU/ml) and 23% were fully protected (> or = 0.1 IU/ml). The results suggested that a high proportion of young population had a protective level of immunity against diphtheria, that susceptibility increased with age and a smaller proportion of males (2.9%) than females (8.3%) were unprotected; this difference was statistically significant. Our results suggest that it may be useful to revaccinate adults with low levels of diphtheria toxoid so that the percentage that remains unprotected does not put the community at risk of an outbreak of diphtheria.

A randomized controlled trial of thymosin-alpha1 versus interferon alfa treatment in patients with hepatitis B e antigen antibody--and hepatitis B virus DNA--positive chronic hepatitis B.

It has recently been shown that thymosin-alpha1(T-alpha1), a synthetic polypeptide of thymic origin, is able to promote disease remission and inhibition of hepatitis B virus (HBV) replication in patients affected by hepatitis B e antigen (HBeAg)-positive chronic active hepatitis. We evaluated the efficacy and safety of T-alpha1 treatment in patients with hepatitis B e antibody (anti-HBe) and HBV-DNA-positive chronic hepatitis. Thirty-three patients were randomly assigned to receive either T-alpha1 900 microg/m2 body surface area twice weekly (17 patients) or 5 MU of interferon alfa (IFN-alpha) three times weekly (16 patients) for 6 months. At baseline, both groups were comparable concerning age, sex, liver histology, and alanine transaminase (ALT) levels. At the end of treatment, complete response (defined as ALT normalization and HBV-DNA loss) occurred in 5 of 17 (29.4%) in the T-alpha1 group and in 7 of 16 (43.8%) in the IFN-alpha group (P = not significant). After a follow-up period of 6 months, a complete response was observed in 7 of 17 (41.2%) in the T-alpha1 group and in 4 of 16 (25%) in the IFN-alpha group (P = n.s.). Compared with the results observed in a group of 15 patients never treated with IFN-alpha and followed for 12 months, the rate of complete response was significantly higher in the IFN-alpha group at the end of therapy (1 of 15 vs. 7 of 16, respectively; P < .05) and in the T-alpha1 group at the end of follow-up (1 of 15 vs. 7 of 17, respectively; P < .05). Unlike IFN-alpha, T-alpha1 was well tolerated by all patients. The only side effect, reported by some, was local discomfort at injection sites. The results of this trial suggest that T-alpha1 is able to reduce HBV replication in patients affected by anti-HBe-positive chronic hepatitis. Furthermore, compared with IFN-alpha, T-alpha1 is better tolerated and seems to induce a gradual and more sustained ALT normalization and HBV-DNA loss. In conclusion, T-alpha1 appears to be a safe and effective alternative treatment for anti-HBe-positive chronic hepatitis. The benefit of this agent in producing long-term inhibition of HBV replication must be confirmed by future trials.

Detection of specific antibodies in immune complexes of farmer's lung patients.

The authors examined 23 precipitin-positive symptomatic patients with Farmer's Lung(FL) and compared them to different groups of exposed asymptomatic precipitin-positive(EAPP) and precipitin- negative(EAPN) farmers. The sera were tested using several techniques (i.e., immunodiffusion and ELISA for specific antibodies; polyethylene glycol [PEG] for circulating immune complexes [CIC]) in an attempt to find an in vitro test correlated with the disease which could also provide an insight into the pathogenic mechanisms of Farmer's Lung. Circulating immune complexes formed by IgG were significantly higher in Farmer's Lung patients than in EAPP subjects. In polyethlyene glycol precipitates from Farmer's Lung patients, specific antibodies found by ELISA correlated well with serum positivity, but they were not found in EAPP subjects. The possibility that the circulating immune complexes found were Ig aggregates was ruled out, as was the possibility that the antibodies found in the polyethylene glycol precipitate were also due to an unspecific link. The authors suggest that the circulating immune complexes of Farmer's Lung patients contain specific specific antibodies and that since their composition is different in EAPP subjects, these circulating immune complexes may play a role in the pathogenesis of the disease.

Evaluation of in vitro efficacy of the disinfectant Virkon.

A study was conducted on a new acid peroxygen system based disinfectant (Virkon), in order to assess its in vitro efficacy. The chemical was tested on different bacteria (Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli), spores (Bacillus subtilis) and on the Hepatitis B surface antigen (HBsAg), and compared in its activity with phenol and glutaraldehyde (calculation of the 'phenol coefficient' and the 'glutaraldehyde coefficient'). The constancy of speed of disinfection, the coefficient of concentration, the minimal inhibitory concentration (MIC) were also determined, and the destruction of the HBsAg antigenic activity was studied using an ELISA kit. The sporicidal efficacy of Virkon was assessed by cultivating spores in agar nutrient after contact with different dilutions of the disinfectant. The results of the tests showed that Virkon has a high concentration coefficient (mean value of k: 0.374/min) and a wide range of action. The low MIC demonstrates how little concentrations of Virkon can inactivate all studied bacteria. The disinfectant was also able to destroy the hepatitis B surface antigen, and it demonstrated good activity against spores, especially if used in physiologic solution. These characteristics, coupled with the absence of initiation or toxic effects on animals showed by other studies, make wide fields of application for the new disinfectant foreseeable.

Removal of heme from preparations of human chorionic somatomammotropin.

The operations involved in the extraction of chorionic somatomammotropin from human placentas cause hemolysis of blood which is present in placental tissue and contamination of crude extract with large amounts of hematic pigments. Most of the pigments are removed by the purification procedure. The portion of purified hCS with high heme content was subjected to treatments with acid acetone and neutral butanone on the basis of procedures generally used for the separation of heme and protein portions in hemoproteins. Both treatments resulted in the removal of heme from hCS; the treatment using butanone was more efficient than the one using acetone. After treatment with both organic solvents, the immunological activity measured with radial immunodiffusion was entirely retained while binding activity on rat ventral prostate particles was slightly decreased.

Effect of the purification procedure on capacity of human chorionic somatomammotropin to bind rat ventral prostate particles.

The purification process can cause alterations in the structure and thus in the activity of the product undergoing purification. In the case of human chorionic somatomammotropin (hCS), a protein hormone of placental origin, the possible effects of purification are unknown, even though it is prepared under mild conditions. hCS is able to displace labelled ovine prolactin from rat ventral prostate membranes and we have measured this activity in a crude and in a purified preparation of the hormone. At the same weight level, both the crude and the purified hormone are equally active.