Levels of different cytokines in women and men with asymptomatic genital infection caused by Chlamydia

INTRODUCTION

Immune response to genital Chlamydia trachomatis infection is involved in both immunity and pathology. The cytokine profile during infection has been implicated in the disease outcome, either resolution or severe sequelae.

METHODOLOGY

In total, 3900 patients were analyzed for presence of genital infections caused by Chlamydia using molecular assays. Interleukins (IL) IL-10, IL-17, IL-6, IL-2 and chemokine IP-10 were estimated by ELISA in urine, cervical swabs and semen samples. Statistical analysis was performed using the T student test.

RESULTS

A total of 47 out of 3900 samples (1.2%) were found to be positive for Chlamydia trachomatis based on the Real Time (RT) PCR results. Statistical analysis revealed that the differences between Chlamydia trachomatis positive and negative samples regarding levels of cytokines were not significant.

CONCLUSIONS

Our results demonstrated that no significant difference in cytokine concentrations exists in Chlamydia trachomatis infected patients when compared to healthy controls. In further study, we aim to test on a greater number of positive samples a greater number of cytokines involved in the immune response to Chlamydia trachomatis infections.

In vitro activity of hybrid lavender essential oils against multidrug resistant strains of Pseudomonas aeruginosa

INTRODUCTION

Lavender is an evergreen shrub native to Northern Africa and other mountainous Mediterranean regions. It grows throughout Southern Europe, the United States, and Australia. Lavender essential oil has been used since ancient times and is known for its anti-inflammatory, antidepressant, antiseptic, antifungal and antimicrobial properties.

METHODOLOGY

in this study, the antimicrobial activity of two Lavender essential oils (Lavanda sumian and Lavanda grosso) against 16 multidrug-resistant P. aeruginosa strains from clinical ocular samples taken from migrant patients has been investigated. The in vitro cytotoxic activity on human Wong-Kilbourne derivative (WKD) conjunctiva cells from healthy patients and nitric oxide synthase (NOS) activity on murine macrophage (J774.1A) were also evaluated.

RESULTS

L. sumian showed lower antimicrobial activity when compared to L. grosso. Both lavender oils tested had no cytotoxic effect at very low concentrations, mostly L. grosso. The essential oils extracted from L. sumian and L. grosso significantly reduced NOS in a cell model.

CONCLUSION

Increase in drug resistance and lack of new antibiotics may encourage the development of natural antimicrobial treatments.

Change in Caco-2 cells following treatment with various lavender essential oils

Lavender is an aromatic evergreen shrub diffused in the Mediterranean basin appreciated since antiquity. The genus Lavandula is part of Lamiaceae family and includes more than 20 species, among which true lavender (L. vera D.C. or L. angustifolia Miller.) and spike lavender (L. latifolia Medikus); there are also numerous hybrids known as lavandins (L. hybrida Rev.). L. vera, spike lavender and several hybrids are the most intensely used breeding species for the production of essential oils. Lavender and lavandin essential oils have been applied in food, pharmaceutical and other agro industries as biological products. In their chemical composition, terpenes linalool and linalyl acetate along with terpenoids such as 1,8-cineole are mostly responsible for biological and therapeutic activities. This study evaluates cytotoxic activity of essential oils derived from four lavender species on human epithelial colorectal adenocarcinoma cells. Analysis of pre- and post-treatment cell morphology has been performed using scanning electron microscope.

Tuberculosis in Sardinia: An investigation into the relationship between natives and immigrants

OBJECTIVE/BACKGROUND

Tuberculosis (TB) has had a recrudescence in the last few decades in Italy as a result of many factors, among which migration from countries where TB is endemic is one of them. In Sardinia, a major island of Italy, there was no knowledge of the mechanisms of transmission of TB in the immigrant subpopulation and the impact it may have on the native subpopulation and on the community as a whole. Therefore, a molecular epidemiological study was carried out to get a clearer picture of the number and genetic features of Mycobacterium tuberculosis strains isolated from immigrants and from natives in Sardinia.

METHODS

Two groups of clinical isolates of M. tuberculosis, one collected from immigrants and the other one from Sardinians, were analyzed in this study. The genotyping was executed through the variable number tandem repeat-mycobacterial interspersed repetitive units technique and a first-line antimycobacterial drug-susceptibility test was also carried out.

RESULTS

Thirty-six clinical isolates from immigrants and 25 from Sardinians were analyzed. Variable number tandem repeat-mycobacterial interspersed repetitive units technique showed that all of them belonged to different strains and there was a quite high allelic diversity among them. Moreover, data collected allowed the finding of, with a good approximation, the phylogenetic relations among the strains isolated and the best-known phylogenetic groups.

CONCLUSION

The study pointed out that since every strain is different, there was no TB transmission in any of the subpopulations and between immigrants and natives. This showed that the presence of immigrants was not a risk factor for contracting TB in the community.

Bacterial agents as a cause of infertility in humans

Infertility is a problem affecting almost 15% of couples. There are many causes for this condition, among which urogenital bacterial infections seem to play an important role. Many studies have explained the mechanisms by which bacteria cause infertility both in men and women. Therefore we undertook this study to evaluate the presence of genito-urinary infections in infertile couples who sought counselling to investigate their condition. Microbiological analysis was performed on semen and vaginal/cervical samples of both partners of each couple. The percentage of individuals affected by a urogenital bacterial infection was between 14 and 20%. More significantly, most of the species isolated both in men and women have been described in the literature as potential causes of infertility.

Chemical composition, cytotoxicity, antimicrobial and antifungal activity of several essential oils

Essential oils (EOs) are known and used for their biological, antibacterial, antifungal and antioxidant properties. Numerous studies have shown that EOs exhibit a large spectrum of biological activities in vitro. The incidence of drug-resistant pathogens and the toxicity of antibiotics have drawn attention to the antimicrobial activity of natural products, encouraging the development of alternative treatments. The aim of this study was to analyse the phytochemical and the cytotoxic characteristic of 36 EOs; we then evaluated the antimicrobial activity of the less-toxic EOs on Gram-positive, Gram-negative and fungi strains. The results showed low cytotoxicity in seven EOs and good activity against Gram-negative and Candida spp. strains. Based on our results, EOs could be proposed as a novel group of therapeutic agents. Further experiments are necessary to confirm their pharmacological effectiveness, and to determine potential toxic effects and the mechanism of their activity in in vivo models.

Essential oils in ocular pathology: an experimental study

INTRODUCTION

The antimicrobial activity of essential oils (EOs) has been known for ages; in particular, the EOs of Melaleuca alternifolia, Thymus vulgaris, Mentha piperita, and Rosmarinus officinalis have been used for the treatment of fungal and bacterial infections.

METHODOLOGY

This study focused on the in vitro cytotoxicity to normal human conjunctiva cells and antimicrobial activity of 20 EOs.

RESULTS

The oils tested showed no cytotoxic effect at very low concentrations. Rosmarinus officinalis, Melaleuca alternifolia, and Thymus vulgaris L. red thyme geraniol sel oils had good antimicrobial activity against Gram-positive and Gram-negative strains.

CONCLUSIONS

The results of this study are of great interest and may have a major impact on public health, providing useful tips to optimize the therapeutic use of some natural drugs.

Fear but not fright: re-evaluating traumatic experience attenuates anxiety-like behaviors after fear conditioning

Fear allows organisms to cope with dangerous situations and remembering these situations has an adaptive role preserving individuals from injury and death. However, recalling traumatic memories can induce re-experiencing the trauma, thus resulting in a maladaptive fear. A failure to properly regulate fear responses has been associated with anxiety disorders, like Posttraumatic Stress Disorder (PTSD). Thus, re-establishing the capability to regulate fear has an important role for its adaptive and clinical relevance. Strategies aimed at erasing fear memories have been proposed, although there are limits about their efficiency in treating anxiety disorders. To re-establish fear regulation, here we propose a new approach, based on the re-evaluation of the aversive value of traumatic experience. Mice were submitted to a contextual-fear-conditioning paradigm in which a neutral context was paired with an intense electric footshock. Three weeks after acquisition, conditioned mice were treated with a less intense footshock (pain threshold). The effectiveness of this procedure in reducing fear expression was assessed in terms of behavioral outcomes related to PTSD (e.g., hyper-reactivity to a neutral tone, anxiety levels in a plus maze task, social avoidance, and learning deficits in a spatial water maze) and of amygdala activity by evaluating c-fos expression. Furthermore, a possible role of lateral orbitofrontal cortex (lOFC) in mediating the behavioral effects induced by the re-evaluation procedure was investigated. We observed that this treatment: (i) significantly mitigates the abnormal behavioral outcomes induced by trauma; (ii) persistently attenuates fear expression without erasing contextual memory; (iii) prevents fear reinstatement; (iv) reduces amygdala activity; and (v) requires an intact lOFC to be effective. These results suggest that an effective strategy to treat pathological anxiety should address cognitive re-evaluation of the traumatic experience mediated by lOFC.

Antifungal, anti-biofilm and adhesion activity of the essential oil of Myrtus communis L. against Candida species

Candida species belong to the normal microbiota of the oral cavity, gastrointestinal tract and vagina. The increasing incidence of drug-resistant pathogens and the toxicity of the antifungal compounds have drawn the attention towards the antimicrobial activity of natural products, an inexpensive alternative. The aim of this work was to evaluate the adhesion activity, the biofilm formation and the action of the Myrtus communis L. essential oil (EO) on the biofilm formation towards three species isolated from clinical samples: Candida albicans, Candida parapsilosis and Candida tropicalis. Furthermore, we evaluated the antimycotic activity of the EO towards the three species, and the results were compared with the minimum inhibitory concentration of six antimycotics. The activity of the EO against C. albicans and C. parapsilosis was better than that obtained against C. tropicalis; moreover, the strains used in the assay were adhesive and biofilm producer, and the effect of myrtle EO on the biofilm formation yielded encouraging results.

Tis21 is required for adult neurogenesis in the subventricular zone and for olfactory behavior regulating cyclins, BMP4, Hes1/5 and Ids

Bone morphogenic proteins (BMPs) and the Notch pathway regulate quiescence and self-renewal of stem cells of the subventricular zone (SVZ), an adult neurogenic niche. Here we analyze the role at the intersection of these pathways of Tis21 (Btg2/PC3), a gene regulating proliferation and differentiation of adult SVZ stem and progenitor cells. In Tis21-null SVZ and cultured neurospheres, we observed a strong decrease in the expression of BMP4 and its effectors Smad1/8, while the Notch anti-neural mediators Hes1/5 and the basic helix-loop-helix (bHLH) inhibitors Id1-3 increased. Consistently, expression of the proneural bHLH gene NeuroD1 decreased. Moreover, cyclins D1/2, A2, and E were strongly up-regulated. Thus, in the SVZ Tis21 activates the BMP pathway and inhibits the Notch pathway and the cell cycle. Correspondingly, the Tis21-null SVZ stem cells greatly increased; nonetheless, the proliferating neuroblasts diminished, whereas the post-mitotic neuroblasts paradoxically accumulated in SVZ, failing to migrate along the rostral migratory stream to the olfactory bulb. The ability, however, of neuroblasts to migrate from SVZ explants was not affected, suggesting that Tis21-null neuroblasts do not migrate to the olfactory bulb because of a defect in terminal differentiation. Notably, BMP4 addition or Id3 silencing rescued the defective differentiation observed in Tis21-null neurospheres, indicating that they mediate the Tis21 pro-differentiative action. The reduced number of granule neurons in the Tis21-null olfactory bulb led to a defect in olfactory detection threshold, without effect on olfactory memory, also suggesting that within olfactory circuits new granule neurons play a primary role in odor sensitivity rather than in memory.

Clinical considerations on Buruli ulcer employing two molecular tests for the detection of Mycobacterium ulcerans in 100 skin biopsies

OBJECTIVES

Buruli ulcer (BU) is an infected cutaneous lesion, the etiological agent of which is Mycobacterium ulcerans. Diagnosis is confirmed by the identification of acid-fast bacilli and culture. In clinically suspicious forms with negative bacteriological or Ziehl-Neelsen (ZN) findings, molecular tests are used. This study compared the concordance of nested polymerase chain reaction (PCR) (targeting IS2404) and PCR (targeting IS2606) in different clinical situations.

METHODS

A total of 57 samples were sourced from 39 BU patients. Control samples (n = 43) were obtained from non-BU ulcers in 38 patients. Samples were divided into two pieces and submitted to, respectively, histological examination and ZN staining, and PCR. Subsamples submitted to PCR were divided and submitted to nested PCR IS2404 and PCR IS2606, respectively.

RESULTS

Of the 57 BU biopsies, positive results were obtained by nested PCR in 18 (31.6%) and by IS2606 PCR in 37 (64.9%) cases. Sequencing of the positive samples confirmed the specificity of amplicons in all nested PCR samples and in 26 of 37 (70.2%) samples positive to IS2606. Hence, nested PCR was more specific (100% vs. 93%) and less sensitive (32% vs. 46%) than IS2606 PCR. In the BU samples, nested PCR was negative in 15 instances, and IS2606 PCR was negative in 11 instances in which ZN histology had been positive (false negatives). Both PCRs were positive in six ZN-negative smears.

CONCLUSIONS

We considered 57 samples from 39 BU patients in various clinical stages and at different times after the beginning of therapy. These provided positive results in 18 cases with IS2404 nested PCR and in 37 cases with PCR IS2606; only 26 of the latter remained positive subsequent to sequencing. Hence, even if IS2404 PCR is considered more specific, in subjects who appear to fail to respond to therapy, it is advisable to also carry out IS2606 PCR. A possible interpretation of the discordance between the two techniques due to unavoidable technical errors as well as to different sensitivity of the two tests at M. ulcerans DNA low concentration (i.e. in recent infection and in well-treated cases) is discussed.

Identification of non-tuberculous mycobacteria from clinical samples

Non-tuberculous mycobacterial infections cause morbidity worldwide. NTM are considered opportunistic pathogens, and several species have been associated with human disease which has typically pulmonary, skin and soft tissue, lymphatic or disseminated presentation. This study evaluated the distribution of non-tuberculous mycobacteria in Sardinia. Mycobacterium avium, Mycobacterium gordonae and Mycobacterium xenopi were frequently found. Our results agreed with literature data both for the frequent isolation of M. avium, M. xenopi and M. gordonae, and the symptoms and radiological evidence of the patients analysed.

Molecular identification of Mycobacterium avium subspecies paratuberculosis in oral biopsies of Crohn's disease patients

Oral lesions may be found in patients with Crohn’s disease (CD), in a percentage up to 20%. The aim of this study was to investigate a possible relationship between Mycobacterium avium subsp. paratuberculosis (MAP) and oral lesions in CD patients. 23 oral biopsies were examined performing IS900 Nested PCR; 9 of them were positive: 8 from CD patients and 1 from a control. Our purpose is to go on with this study, amplifying the number of subjects examined and testing subjects with oral lesions related to diseases other than CD to verify the specific association between MAP and oral lesions in CD patients.

Tuberculin skin test and QuantiFERON in children

Until some time ago, the tuberculin skin test was the only available screening test for the diagnosis of tubercular infection. Now the new interferon-? release assay QuantiFERON-TB Gold shows promise of greater accuracy in the detection of Mycobacterium tuberculosis-infected subjects. The aim of our study was to evaluate the use of QuantiFERONTB Gold in children and to verify its agreement with the tuberculin skin test. A total of 27 children had a positive tuberculin skin test, 76 subjects were negative and the remaining 2 had a dubious Mantoux test. A positive QuantiFERONTB Gold result was obtained in 21 children while in 84 it was negative. No statistically significant difference was detected between the two assays, which showed a concordance of 90.57%. Our results demonstrated a good concordance between the tuberculin skin test and the interferon-? release assay, though the QuantiFERON-TB may have several advantages over the Mantoux test.

Antimycotic activity of Myrtus communis L. towards Candida spp. from clinical isolates

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Btg1 is Required to Maintain the Pool of Stem and Progenitor Cells of the Dentate Gyrus and Subventricular Zone

Btg1 belongs to a family of cell cycle inhibitory genes. We observed that Btg1 is highly expressed in adult neurogenic niches, i.e., the dentate gyrus and subventricular zone (SVZ). Thus, we generated Btg1 knockout mice to analyze the role of Btg1 in the process of generation of adult new neurons. Ablation of Btg1 causes a transient increase of the proliferating dentate gyrus stem and progenitor cells at post-natal day 7; however, at 2 months of age the number of these proliferating cells, as well as of mature neurons, greatly decreases compared to wild-type controls. Remarkably, adult dentate gyrus stem and progenitor cells of Btg1-null mice exit the cell cycle after completing the S phase, express p53 and p21 at high levels and undergo apoptosis within 5 days. In the SVZ of adult (two-month-old) Btg1-null mice we observed an equivalent decrease, associated to apoptosis, of stem cells, neuroblasts, and neurons; furthermore, neurospheres derived from SVZ stem cells showed an age-dependent decrease of the self-renewal and expansion capacity. We conclude that ablation of Btg1 reduces the pool of dividing adult stem and progenitor cells in the dentate gyrus and SVZ by decreasing their proliferative capacity and inducing apoptosis, probably reflecting impairment of the control of the cell cycle transition from G1 to S phase. As a result, the ability of Btg1-null mice to discriminate among overlapping contextual memories was affected. Btg1 appears, therefore, to be required for maintaining adult stem and progenitor cells quiescence and self-renewal.

Tuberculosis patients are characterized by a low-IFN-γ/high-TNF-α response to methylated HBHA produced in M. smegmatis

Whole blood from Mycobacterium tuberculosis-infected subjects was stimulated with heparin-binding hemagglutinin (HBHA). Tuberculosis (TB) patients showed an HBHA-specific T-cell response characterized by low-IFN-γ/high-TNF-α secretion, while asymptomatic subjects with latent infection (LTBI) and TB patients under therapy showed a pattern with high IFN-γ/low TNF-α. These results underscore the usefulness of HBHA in helping to distinguish LTBI subjects versus TB patients.

Interaction between Mycobacterium tuberculosis, Mycobacterium bovis, Mycobacterium avium subspecies paratuberculosis with the enteric glia and microglial cells

Background

We investigated the interaction of Mycobacterium avium subspecies paratuberculosis, M. bovis and M. tuberculosis and different glial cells (enteric glial and microglial cells) in order to evaluate the infecting ability of these microorganisms and the effects produced on these cells, such as the evaluation of cytokines expression.

Results

Our experiments demonstrated the adhesion of M. paratuberculosis to the enteroglial cells and the induction of IL-1A and IL-6 expression; M. tuberculosis and M. bovis showed a good adhesive capability to the enteric cell line with the expression of the following cytokines: IL-1A and IL-1B, TNF-α, G-CSF and GM-CSF; M. bovis induced the expression of IL-6 too.

The experiment performed with the microglial cells confirmed the results obtained with the enteroglial cells after the infection with M. tuberculosis and M. bovis, whereas M. paratuberculosis stimulated the production of IL-1A and IL-1B.

Conclusion

Enteroglial and microglial cells, could be the target of pathogenic mycobacteria and, even if present in different locations (Enteric Nervous System and Central Nervous System), show to have similar mechanism of immunomodulation.

Preliminary data of different methods for the indirect diagnosis of Mycobacterium bovis infection

We compared the response induced by QuantiFERON-TB Gold antigens to that obtained with the Intradermal Comparative Tuberculin Test and BOVIGAM assay. Our results showed that the QuantiFERON-TB Gold technique used in humans could also be applied for the diagnosis of TB infection in cattle.

Usefulness of the QuantiFERON-TB-Gold in tube in a population at risk of bovine tubercular infection

The effectiveness of the QuantiFERON-TB-Gold in tube was compared with PPD to detect tuberculosis infection in the staff of cattle-farms, as a consequence of an outbreak of bovine tuberculosis in livestock. The data revealed the advantage of the immunological test for the specific detection of subjects infected by Mycobacterium tuberculosis complex.

Mycobacterium avium subspecies paratuberculosis infection in cases of irritable bowel syndrome and comparison with Crohn's disease and Johne's disease: common neural and immune pathogenicities

Mycobacterium avium subsp. paratuberculosis causes Johne's disease, a systemic infection and chronic inflammation of the intestine that affects many species, including primates. Infection is widespread in livestock, and human populations are exposed. Johne's disease is associated with immune dysregulation, with involvement of the enteric nervous system overlapping with features of irritable bowel syndrome in humans. The present study was designed to look for an association between Mycobacterium avium subsp. paratuberculosis infection and irritable bowel syndrome. Mucosal biopsy specimens from the ileum and the ascending and descending colon were obtained from patients with irritable bowel syndrome attending the University of Sassari, Sassari, Sardinia, Italy. Crohn's disease and healthy control groups were also included. Mycobacterium avium subsp. paratuberculosis was detected by IS900 PCR with amplicon sequencing. Data on the potential risk factors for human exposure to these pathogens and on isolates from Sardinian dairy sheep were also obtained. Mycobacterium avium subsp. paratuberculosis was detected in 15 of 20 (75%) patients with irritable bowel syndrome, 3 of 20 (15%) healthy controls, and 20 of 23 (87%) people with Crohn's disease (P = 0.0003 for irritable bowel syndrome patients versus healthy controls and P = 0.0000 for Crohn's disease patients versus healthy controls). One subject in each group had a conserved single-nucleotide polymorphism at position 247 of IS900 that was also found in isolates from seven of eight dairy sheep. There was a significant association (P = 0.0018) between Mycobacterium avium subsp. paratuberculosis infection and the consumption of hand-made cheese. Mycobacterium avium subsp. paratuberculosis is a candidate pathogen in the causation of a proportion of cases of irritable bowel syndrome as well as in Crohn's disease.

[1,2,3]Triazolo[4,5-h]quinolones. A new class of potent antitubercular agents against multidrug resistant Mycobacterium tuberculosis strains

In this preliminary study we report the activity of 3-methyl-9-substituted-6-oxo-6,9-dihydro-3H-[1,2,3]-triazolo[4,5-h]quinolone-carboxylic acids and their esters as a new class of antiinfective agents against MDR Mycobacterium tuberculosis. In antitubercular screening against H37Rv and 11 clinically isolated strains of M. tuberculosis several derivatives (1o,3a,c,i,j,p) showed MIC(90) in the range 0.5-3.2 microg/mL. 3c showed no cytotoxicity and proved to be the most potent derivative exhibiting MIC(90)=0.5 microg/mL against all M. tuberculosis strains and infected human macrophages (J774-A1) tested.

In vitro efficacy of Linezolid on clinical strains of Mycobacterium tuberculosis and other mycobacteria

Linezolid, an oxazolidinone that acts by inhibiting protein synthesis, was evaluated in strains of tuberculosis and non-tubercular mycobacteria resistant to one or more drugs isolated in northern Sardinia. The in vitro activity of Linezolid (Pfizer) was assessed on different isolates of Mycobacterium spp. from clinical samples by the Proportional Method. Linezolid demonstrated an excellent activity against the 24 strains of M. tuberculosis and against M. gordonae, M. marinum, M. aurum, M. phlei, and M. avium, with MIC values ranging from 0.5 to 2 microg/ml. Linezolid can be used in combination with the standard antitubercular medications, or as an effective therapeutic alternative in infections caused by M. tuberculosis or by other species of non-tubercular mycobacteria.

Immunogenicity and cytoadherence of recombinant heparin binding haemagglutinin (HBHA) of Mycobacterium avium subsp. paratuberculosis: functional promiscuity or a role in virulence?

Mycobacterium avium subsp. paratuberculosis (MAP) is the causative agent of Johne's Disease, a chronic granulomatous enteritis of ruminants. Recently, an association of MAP bacilli with Crohn's disease in humans has been proposed. Due to genetic similarities and serological cross-reactivity of the M. avium complex with other mycobacteria, functional analysis of species-specific proteins may allow new insights into the pathogenesis of mycobacterial diseases. We report production and molecular characterization of the recombinant HBHA from the MAP complex bacilli. The HBHA was expressed in Escherichia coli and Mycobacterium smegmatis using efficient expression vector systems. The recombinant HBHA was found to be immunogenic and therefore induced antibody responses in cattle against the MAP bacilli with a possible cross reactivity with M. bovis infection. The MAP complex HBHA was thus found to be a target of the host humoral responses in Johne's disease. The recombinant HBHA protein was also found to be adherent to the Caco2 cell lines in-vitro, a significant observation to understand possible virulence mechanisms. Since M. tuberculosis HBHA was earlier shown to be involved in dissemination of the tubercle bacilli, the immunogenicity and cytoadherent nature of this MAP protein possibly suggests functional promiscuity.

Detection and Isolation of Mycobacterium avium subspecies paratuberculosis from intestinal mucosal biopsies of patients with and without Crohn's disease in Sardinia

OBJECTIVES

Sardinia is an island community of 1.6 million people. There are also about 3.5 million sheep and one hundred thousand cattle in which Johne's disease and Mycobacterium avium subspecies paratuberculosis infection are endemic. The present study was designed to determine what proportion of people in Sardinia attending for ileocolonoscopy with or without Crohn's disease were infected with this pathogen.

METHODS

Mycobacterium avium subspecies paratuberculosis was detected by IS900 PCR on DNA extracts of fresh intestinal mucosal biopsies as well as by isolation in culture using supplemented MGIT media followed by PCR with amplicon sequencing.

RESULTS

Twenty five patients (83.3%) with Crohn's disease and 3 control patients (10.3%) were IS900 PCR positive (p = 0.000001; Odds ratio 43.3). Mycobacterium avium subspecies paratuberculosis grew in cultures from 19 Crohn's patients (63.3%) and from 3 control patients (10.3%) (p = 0.00001; Odds ratio 14.9). All patients positive by culture had previously been positive by PCR. Mycobacterium avium subspecies paratuberculosis first appeared in the liquid cultures in a Ziehl Neelsen (ZN) staining negative form and partially reverted through a rhodamine-auramine positive staining form to the classical ZN positive form. This resulted in a stable mixed culture of all 3 forms illustrating the phenotypic versatility of these complex chronic enteric pathogens.

CONCLUSIONS

Mycobacterium avium subspecies paratuberculosis was detected in the majority of Sardinian Crohn's disease patients. The finding of the organism colonizing a proportion of people without Crohn's disease is consistent with what occurs in other conditions caused by a primary bacterial pathogen in susceptible hosts.

[Improvement of short-term prognosis in patients with refractory heart failure]

BACKGROUND

Prognosis of patients with severe heart failure is poor, despite improved results in medical therapy. Heart transplantation is the only treatment possible in end-stage heart failure. The aim of this study was to evaluate the variation in prognosis over the past six years in the patients admitted to Intensive Care Unit for heart failure in spite of optimal oral therapy. STUDY POPULATION AND METHOD: Between January 1990 and December 1995, 133 patients with heart failure were admitted to the Intensive Care Unit, despite the fact that they were on optimal oral therapy. All patients were in New York Heart Association (NYHA) functional class III to IV and required intravenous administration of sympathomimetic amines, in addition to standard heart failure treatment procedures. Cumulative survival at six months of patients observed between 1990-1992 (group A) was compared with the survival rate of patients observed from 1993 to 1995 (group B).

RESULTS

Clinical and haemodynamic parameters were similar in groups A and B, but ACE-inhibitors were used more frequently in group B (75 vs 31% respectively, p < 0.05). During the follow-up period, heart transplantation was indicated in a similar percentage of patients (A 53% vs B 58%). However, mortality on the waiting list (58% group A vs 21% group B; p < 0.05) and the percentage of patients who underwent heart transplantation (41% group A vs 78% group B; p < 0.05) differed. Moreover, all patients in group A and 50% of group B were operated on as "status one" patients. The total six-month mortality rate decreased from 69% before 1992 to 48% thereafter (p < 0.05).

CONCLUSION

The short-term prognosis of patients with refractory heart failure improved over time. In the latter period, ACE-inhibitors were used more frequently and the number of heart transplantations was greater. Nevertheless, our results do not allow us to identify the causes of the improved survival rate.

[Indications for heart transplant: retrospective evaluation of criteria for selection of candidates]

INTRODUCTION

Heart transplantation (HT) is a largerly accepted therapy for patients with refractory congestive heart failure. However, lack of donors imposes a rigorous choice among candidates for transplantation. Aim of this study was to identify retrospectively determinants for the selection of recipients.

METHODS

Between december 1985 and december 1993 500 patients were listed for HT at the Department of Cardiovascular Surgery of the Padua University. Among United Network for Organ Sharing (UNOS) status II patients, 42 transplanted (group I) and 38 died waiting for a donor (group II) were chosen. The following parameters were collected at the time of insertion into the waiting list: sex, blood group, diagnosis, age, body surface area, natriemia, renal function, hepatic function, presence of ventricular arrhythmias, use of ACE-inhibitors, cardiac index, mean pulmonary pressure, mean wedge pressure, mean arterial pressure, central venous pressure, pulmonary arteriolar resistances, left ventricular ejection fraction. Also the time on waiting list until a final event (transplantation or death) was considered.

RESULTS

Comparing the two groups the diagnosis of dilated cardiomyopathy (59.4% group I vs 36.8% group II; p = 0.04) and ejection fraction (26.4 +/- 9.1% group I vs 22.2 +/- 8.0% group II; p = 0.03) were the only variables statistically different. Multivaried analysis evidenced some parameters as independent predictors for HT. In detail, being listed for HT for more than 6 months lowered the probability to receive a heart to 0.34, while waiting for more than 12 months increased it to 2.64. Mean arterial pressure higher than 75 mmHg increased the probability for HT to 2.87, while an increase in mean pulmonary pressure of 5 mmHg lowered the probability to 0.80. An increase in the cardiac index of 0.5 l/m1/m2 lowered the probability to 0.61. A blood group other than 0 increased the possibility to 3.60, the basal surface area higher than 1.78 m2 lowered it to 0.306 and an ejection fraction higher than 22% increased it to 3.94.

CONCLUSIONS

We can conclude that parameters which predict the outcome of patients listed for HT were not only size matching, blood group and waiting time, but also ejection fraction, arterial pressure and diagnosis.

[Anaphylactoid reaction during administration of tissue plasminogen activator (t-PA)]

The use of tissue plasminogen activator (t-PA) in the management of acute myocardial infarction, as effective thrombolytic agent, is well established. Thrombolytic therapy, limiting the extent of myocardial necrosis, reduces the infarct-related morbidity and mortality and improves the prognosis in patients with acute myocardial infarction. Thrombolytic agents present various side effects. Allergic reactions may occur with both streptokinase (ST) (or with anistreplase, the equimolecular mixture of streptokinase and human plasminogen); and t-PA. The incidence of allergic reactions associated with the use of t-PA is much lower if compared with other thrombolytic agents. Since t-PA is structurally identical to endogenous t-PA, its administration should not cause anaphylactic reactions. The purpose of this case presentation is to describe the occurrence of an anaphylactoid reaction during infusion of t-PA in a 63 year-old man, admitted to the Cardiac Care Unit (C.C.U.) with diagnosis of acute myocardial infarction.

Effect of amiloride on inotropic and toxic actions of ouabain in guinea-pig left atria

The effect of amiloride on the positive inotropic and toxic effects of ouabain in guinea-pig left atria has been studied. In atria driven at 1 Hz, amiloride (0.3 and 0.5 mM) decreased the EC50 but did not affect the maximal tension developed by ouabain. At 0.1 Hz, amiloride did not change either the EC50 or the maximal tension developed by ouabain. Ouabain toxicity (onset of arrhythmias) was not changed by amiloride at either frequency of stimulation. Therefore, amiloride did not antagonize either the positive inotropic or the toxic effect of ouabain. The positive inotropic effect of amiloride has been ascribed to the inhibition of the Na+/Ca2+ exchanger. Since amiloride inhibits also the Na+/H+ exchanger, 5-(N-ethyl-N-isopropyl)amiloride (EIPA), an amiloride derivative which selectively inhibits the Na+/H+ exchange, has been tested to evaluate the role of the Na+/H+ exchange in the amiloride-ouabain interaction. EIPA increased the EC50 values of ouabain and decreased the maximal developed tension by the glycoside in atria driven at 0.1 and 1 Hz, but did not antagonize the toxic response (arrhythmias) of atria to ouabain. It is suggested that the inhibition of Ca2+ exit through the Na+/Ca2+ exchange by amiloride and ouabain may explain the observation that the positive inotropic effects of amiloride and ouabain are additive.

[Positive inotropic effect of amiloride and inhibition of Na+/Ca2+ exchange: dependence on temperature]

Na+/Ca2+ exchange plays a fundamental role in the regulation of intracellular Ca2+ levels and thus myocardial contractility. The influence of temperature variations on Na+/Ca2+ exchange activity in bovine heart sarcolemmal vesicles has been studied. Furthermore, the temperature dependence of positive inotropic response induced by amiloride, an inhibitor of Na+/Ca2+ exchange activity, has been investigated in isolated guinea-pig left atria driven at 1 Hz. Our results indicate that cooling from 37 degrees to 20 degrees C inhibits Na+/Ca2+ exchange activity in sarcolemmal vesicles, whereas does not change the extent of Na+/Ca2+ exchange inhibition by amiloride. In addition, the positive inotropic effect induced by amiloride in guinea-pig left atria decreases and eventually disappears when temperature is progressively reduced from 35 degrees to 23 degrees C. A possible relationship between the decrease in Na+/Ca2+ exchange activity induced by cooling and the temperature dependence of positive inotropic effect of amiloride is discussed.