Allele-Specific PCR Method Based on pncA and oxyR Sequences for Distinguishing Mycobacterium bovis from Mycobacterium tuberculosis: Intraspecific M. bovis pncA Sequence Polymorphism

An allele-specific amplification method based on two genetic polymorphisms to differentiate Mycobacterium tuberculosis from Mycobacterium bovis was tested. Based on the differences found at position 169 in the pncA genes from M. tuberculosis and M. bovis, a PCR system which was able to differentiate most of the 237 M. tuberculosis complex isolates tested in one of the two species was developed. All 121 M. tuberculosis strains showed the expected base (cytosine) at position 169. Most of the M. bovis isolates had a guanine at the cited position. Nevertheless, 18 of the 116 M. bovis isolates, all of them goat isolates, showed the pncA polymorphism specific to M. tuberculosis. These results suggest that goat M. bovis may be the nicotinamidase-missing link at the origin of the M. tuberculosis species. Based on the polymorphism found at position 285 in the oxyR gene, the same system was used to differentiate M. tuberculosis from M. bovis. In this case, DNAs from all 121 M. tuberculosis isolates had the expected base (guanine) at this position. In addition, all 116 M. bovis isolates, including those from goats, showed the identical polymorphism (adenine). The oxyR allele-specific amplification method can differentiate M. bovis from M. tuberculosis, is rapid (results can be obtained in less than 3 h), and is easy to perform.     

Schistosomiasis: an unusual cause of tubal infertility

A case report of a Nigerian woman having an unusual cause oftubal infertility is presented. On histological examinationof the Fallopian tube, ova of Schistosoma haematobium enclosingliving miracidia were found in the smooth muscle layer of theFallopian tube and its mesosalpinx. Mechanisms of tubal involvementare analysed. The case indicates the need to consider schisto-somiasisas a possible aetiological factor in patients with tubal infertilitycoming from areas where the disease is endemic.     

Haplotype analysis of the BRCA2 9254delATCAT recurrent mutation in breast/ovarian cancer families from Spain

A frame-shift 9254del5 mutation was independently identified in 12 families, eleven of them with Spanish ancestors, in a BRCA2 screening performed in 841 breast and/or ovarian cancer families and in 339 women with breast cancer diagnosed before the age of 40 at different centers in France and Spain. We sought to analyze in detail the haplotype and founder effects of the 9254del5 and to estimate the time of origin of the mutation. Eight polymorphic microsatellite markers and two BRCA2 polymorphisms were used for the haplotype analyses. The markers were located flanking the BRCA2 gene spanning a region of 6.1 cM. Our results suggest that these families shared a common ancestry with BRCA2 9254del5, which is a founder mutation originating in the Northeast Spanish, with an estimated age of 92 (95% CI 56-141) generations.     

Inflammatory Responses in Blood Samples of Human Immunodeficiency Virus-Infected Patients with Pulmonary Infections

We analyzed the characteristics of the inflammatory response occurring in blood during pulmonary infections in human immunodeficiency virus (HIV)-infected patients. A prospective study of consecutive hospital admissions of HIV-infected patients with new-onset radiologic pulmonary infiltrates was carried out in a tertiary university hospital from April 1998 to May 2001. Plasma cyclic AMP receptor protein (CRP), interleukin 1β (IL-1β), IL-6, IL-8, IL-10, and tumor necrosis factor alpha (TNF-α) levels were determined at the time of admission and 4, 5, and 6 days later. Patients were included in a protocol addressed to study etiology and outcome of disease. A total of 249 episodes of infection were included, with the main diagnoses being bacterial pneumonia (BP) (118 episodes), Pneumocystis carinii pneumonia (PCP) (41 episodes), and mycobacteriosis (36 episodes). For these three patient groups, at the time of admission the median CRP and cytokine levels were as follows: CRP, 10.2, 3.8 and 5 mg/dl, respectively (P = 0.0001); IL-8, 19, 3, and 2.9 pg/ml (P = 0.045); and TNF-α, 46.4, 44, and 75 pg/ml, respectively (P = 0.029). There were no significant differences in levels of IL-1β, IL-6, or IL-10 among the patient groups. A total of 23 patients died. At the time of admission, HIV-infected patients with BP had higher plasma CRP and IL-8 levels than did PCP and mycobacteriosis patients. TNF-α levels were higher in patients with mycobacteriosis. An elevated IL-8 level (>61 pg/ml) at the time of admission was an independent factor associated with higher mortality (odds ratio, 12; 95% confidence interval, 1.2 to 235.5).     

Peanut-induced anaphylaxis in children and adolescents: Data from the European Anaphylaxis Registry

Background

Peanut allergy has a rising prevalence in high-income countries, affecting 0.5%–1.4% of children. This study aimed to better understand peanut anaphylaxis in comparison to anaphylaxis to other food triggers in European children and adolescents.

Methods

Data was sourced from the European Anaphylaxis Registry via an online questionnaire, after in-depth review of food-induced anaphylaxis cases in a tertiary paediatric allergy centre.

Results

3514 cases of food anaphylaxis were reported between July 2007 - March 2018, 56% in patients younger than 18 years. Peanut anaphylaxis was recorded in 459 children and adolescents (85% of all peanut anaphylaxis cases). Previous reactions (42% vs. 38%; p = .001), asthma comorbidity (47% vs. 35%; p < .001), relevant cofactors (29% vs. 22%; p = .004) and biphasic reactions (10% vs. 4%; p = .001) were more commonly reported in peanut anaphylaxis. Most cases were labelled as severe anaphylaxis (Ring&Messmer grade III 65% vs. 56% and grade IV 1.1% vs. 0.9%; p = .001). Self-administration of intramuscular adrenaline was low (17% vs. 15%), professional adrenaline administration was higher in non-peanut food anaphylaxis (34% vs. 26%; p = .003). Hospitalization was higher for peanut anaphylaxis (67% vs. 54%; p = .004).

Conclusions

The European Anaphylaxis Registry data confirmed peanut as one of the major causes of severe, potentially life-threatening allergic reactions in European children, with some characteristic features e.g., presence of asthma comorbidity and increased rate of biphasic reactions. Usage of intramuscular adrenaline as first-line treatment is low and needs to be improved. The Registry, designed as the largest database on anaphylaxis, allows continuous assessment of this condition.

     

Patterns of reactivity to lipid transfer proteins of plant foods and Artemisia pollen: an in vivo study

BACKGROUND: Lipid transfer proteins (LTPs) are major allergens of Rosaceae fruits in the Mediterranean area. IgE-cross-reactivity has been demonstrated in vitro among LTPs from peach, apple, chestnut and Artemisia pollen. The aim of this study was to evaluate the reactivity to LTPs from peach, apple, chestnut and Artemisia pollen by means of skin prick tests (SPTs). METHODS: Forty-seven patients allergic to peach (peach group), 20 patients sensitized to Artemisia pollen with no food allergies (Artemisia group), and 12 control subjects were skin tested with fresh peach, as well as with whole extracts and purified LTPs of peach, apple, chestnut and Artemisia pollen. RESULTS: The rates of positive SPTs for peach, apple, chestnut and Artemisia LTPs were, respectively, 91, 77, 23, and 36% in the peach group, and 30, 5, 15 and 40% in the Artemisia group. No response was observed in the control subjects. SPTs with peach LTP strongly correlated with SPTs conducted with fresh peach. In the peach group, the most frequent pattern of reactivity to LTPs was the combination peach-apple (45%), followed by peach-apple-Artemisia-chestnut (21%). Significant correlations were found between peach and apple LTPs, and between Artemisia and chestnut LTPs. Positive SPTs to chestnut LTP were only observed in patients with positive SPTs to Artemisia LTP. All the patients with positive case histories to chestnut reacted to chestnut LTP. CONCLUSIONS: LTPs are plant panallergens with different patterns of cross-reactivity. They are major allergens of Rosaceae fruits and seem to be involved in allergic reactions to unrelated foodstuffs such as chestnut, probably through sensitization to the cross-reactive Artemisia LTP. Rosaceae LTPs could be useful tools for in vivo diagnosis of Rosaceae fruit allergy.     

Expansions and contractions of the FMR1 CGG repeat in 5,508 transmissions of normal,intermediate, and premutation alleles

Instability of the FMR1 repeat, commonly observed in transmissions of premutation alleles (55–200 repeats), is influenced by the size of the repeat, its internal structure and the sex of the transmitting parent. We assessed these three factors in unstable transmissions of 14/3,335 normal (~5 to 44 repeats), 54/293 intermediate (45–54 repeats), and 1561/1,880 premutation alleles. While most unstable transmissions led to expansions, contractions to smaller repeats were observed in all size classes. For normal alleles, instability was more frequent in paternal transmissions and in alleles with long 3′ uninterrupted repeat lengths. For premutation alleles, contractions also occurred more often in paternal than maternal transmissions and the frequency of paternal contractions increased linearly with repeat size. All paternal premutation allele contractions were transmitted as premutation alleles, but maternal premutation allele contractions were transmitted as premutation, intermediate, or normal alleles. The eight losses of AGG interruptions in the FMR1 repeat occurred exclusively in contractions of maternal premutation alleles. We propose a refined model of FMR1 repeat progression from normal to premutation size and suggest that most normal alleles without AGG interruptions are derived from contractions of maternal premutation alleles.     

Profilin-mediated food-induced allergic reactions are associated with oral epithelial remodeling

1. Download high-res image (218KB)
2. Download full-size image

     

Effect of using the flow or the volume signals on the measurement of nonapneic respiratory events

STUDY OBJECTIVES: To assess whether the measurement of breathing reduction during obstructive sleep events depends on using the flow or the volume signals recorded with a pneumotachograph. DESIGN: Prospective observational study. SETTING: Sleep laboratory in a University Hospital. PATIENTS OR PARTICIPANTS: Data from 10 male patients with sleep apnea (54 +/- 11 years, apnea-hypopnea index: 43 +/- 21 events/hour, body mass index: 30 +/- 2 kg/m2). INTERVENTIONS: Slow modification of continuous positive airway pressure was performed during full-polysomnography continuous positive airway pressure titration. MEASUREMENTS AND RESULTS: Air flow was measured by a pneumotachograph, and volume was computed by numerical integration. Obstructive events of different magnitude were selected. In 500 breathing cycles analyzed, the reduction in tidal volume was greater than the reduction in the flow amplitude: mean difference of 0.091 (i.e., 9.1% amplitude) and limits of agreement of 0.095 and -0.277 (i.e., 9.5% and -27.7% amplitude). In 14% of the cycles, the reduction in flow was < 50%, whereas the reduction in volume was > 50%, resulting in discordant event classification. CONCLUSIONS: The quantification of breathing reduction depends on whether the flow or the volume signal is used to assess breathing during sleep.