Gut Microbiota-Derived Trimethylamine N-Oxide Contributes to Abdominal Aortic Aneurysm Through Inflammatory and Apoptotic Mechanisms

BACKGROUND

Large-scale human and mechanistic mouse studies indicate a strong relationship between the microbiome-dependent metabolite trimethylamine N-oxide (TMAO) and several cardiometabolic diseases. This study aims to investigate the role of TMAO in the pathogenesis of abdominal aortic aneurysm (AAA) and target its parent microbes as a potential pharmacological intervention.

METHODS

TMAO and choline metabolites were examined in plasma samples, with associated clinical data, from 2 independent patient cohorts (N=2129 total). Mice were fed a high-choline diet and underwent 2 murine AAA models, angiotensin II infusion in low-density lipoprotein receptor-deficient (Ldlr-/-) mice or topical porcine pancreatic elastase in C57BL/6J mice. Gut microbial production of TMAO was inhibited through broad-spectrum antibiotics, targeted inhibition of the gut microbial choline TMA lyase (CutC/D) with fluoromethylcholine, or the use of mice genetically deficient in flavin monooxygenase 3 (Fmo3-/-). Finally, RNA sequencing of in vitro human vascular smooth muscle cells and in vivo mouse aortas was used to investigate how TMAO affects AAA.

RESULTS

Elevated TMAO was associated with increased AAA incidence and growth in both patient cohorts studied. Dietary choline supplementation augmented plasma TMAO and aortic diameter in both mouse models of AAA, which was suppressed with poorly absorbed oral broad-spectrum antibiotics. Treatment with fluoromethylcholine ablated TMAO production, attenuated choline-augmented aneurysm initiation, and halted progression of an established aneurysm model. In addition, Fmo3-/- mice had reduced plasma TMAO and aortic diameters and were protected from AAA rupture compared with wild-type mice. RNA sequencing and functional analyses revealed choline supplementation in mice or TMAO treatment of human vascular smooth muscle cells-augmented gene pathways associated with the endoplasmic reticulum stress response, specifically the endoplasmic reticulum stress kinase PERK.

CONCLUSIONS

These results define a role for gut microbiota-generated TMAO in AAA formation through upregulation of endoplasmic reticulum stress-related pathways in the aortic wall. In addition, inhibition of microbiome-derived TMAO may serve as a novel therapeutic approach for AAA treatment where none currently exist.

Abstract 127: Aspirin Resistant Biomechanical Platelet Activation In Fibromuscular Dysplasia: Novel Mechanisms Of Platelet Activation & Stroke

Background: Fibromuscular dysplasia (FMD) is a non-atherosclerotic, non-inflammatory disorder characterized by abnormal arterial morphology and turbulent blood flow. In regions of disturbed blood flow, circulating platelets may become activated. Cerebrovascular FMD is common and increases the risk of stroke in affected patients. Most FMD patients are treated with antiplatelet agents, however these medications target biochemical and not biomechanical pathways of platelet activation.

Methods: Thrombotic outcomes were determined by multivariate regression analysis of 105,887 patients with FMD. Platelets were isolated from humans and activation was assessed by FACS and aggregometry following exposure to ex vivo steady laminar and disturbed flow (SF and DF, respectively) conditions using a cone and flow system. Single-cell phenotyping of control and FMD platelets with transcriptomics (RNAseq) and proteomics were performed. Cellular bioenergetics were evaluated by real-time metabolic analyses.

Results: In patients with FMD, long-term aspirin therapy is paradoxically an independent risk factor for acute ischemic stroke (OR 1.64, 95% CI 1.29-1.94) but seems to protect against acute hemorrhagic stroke (OR 0.47, 95% CI 0.24-0.89). FMD platelet activation and aggregation were hyporeactive to biochemical agonists, but hyperreactive to ex vivo mechanical, disturbed blood flow conditions compared to age/gender-matched controls. FMD platelet activation in DF was attenuated by the mechanosensitive channel inhibitor, GsMTx4. Principle component analyses of RNAseq and proteomics identified markedly different platelet phenotypes with key differences in mitochondrial function/fission. Platelet imaging and metabolic analyses revealed abnormal mitochondrial architecture and respiration in FMD.

Conclusions: FMD platelets display a divergent, dysregulated platelet phenotype with attenuated biochemical but augmented biomechanical activation. DF exposure of platelets in irregularly shaped arteries in FMD may alter the platelet phenotype and metabolic function. Therapeutics targeting biomechanical pathways of platelet activation may provide a superior mechanism for stroke prevention without unintended bleeding consequences.

Impact of incidental parathyroidectomy and mediastinal-recurrent cellular and lymph-node dissection on parathyroid function after total thyroidectomy

OBJECTIVES

To determine the impact of incidental parathyroidectomy and mediastinal-recurrent cellular and lymph-node dissection on parathyroid function after total thyroidectomy.

MATERIAL AND METHODS

A single-center retrospective study was conducted for a 5-year period in a university hospital center, including 605 patients undergoing total thyroidectomy, 52 of whom had mediastinal-recurrent cellular and lymph-node dissection.

ENDPOINTS

The main endpoint was intraoperative number of parathyroid glands as predictor of parathyroid hormone (PTH) level and postoperative hypocalcemia. The secondary endpoint was the correlation between associated mediastinal-recurrent cellular and lymph-node dissection and incidental parathyroidectomy and its impact on PTH level and calcemia in the immediate postoperative period and at 1 month.

RESULTS

161 patients (26.61%) showed hypocalcemia in the immediate postoperative period and 12 (1.98%) at 1 month. Mediastinal-recurrent cellular and lymph-node dissection increased incidental parathyroidectomy risk 4.6-fold. Mediastinal-recurrent cellular and lymph-node dissection was associated with a statistically "suggestive" decrease in day-1 calcemia (P=0.03), and no significant decrease at 1 month (P=0.52). Incidental parathyroidectomy (6.7% of cases with parathyroidectomy versus 1.3% without) did not significantly increase the rate of early hypocalcemia (P=0.28), but was associated with a "suggestive" worsening at 1 month (P=0.02).

CONCLUSION

Hypocalcemia after total thyroidectomy is a complex, probably multifactorial issue. Systematic parathyroid gland identification is not recommended due to the increased risk of gland lesion, mainly by devascularization. Incidental parathyroidectomy may induce hypocalcemia at 1 month postoperatively (statistically "suggestive" association).

Head and neck squamous cell carcinoma and metachronous second primaries

OBJECTIVES

To assess the rate of second (or more) primaries after treatment for head and neck squamous cell carcinoma (HNSCC), and survival compared to patients with a single head and neck cancer.

MATERIAL AND METHOD

A single-center retrospective study was performed in a University Hospital Center in 541 patients between 2002 and 2010.

RESULTS

One hundred and forty-one patients (26.06%) presented 172 metachronous cancers. Overall 5-year survival was 20.3% with and 38.1% without metachronous cancer. Median and mean survival were respectively 21.9 and 51 months in patients with a single cancer, versus 13.9 and 26.5 months in case of metachronous cancer. Specific survival was comparable to overall survival. All-cause and specific survival were significantly poorer in metachronous cancer (P=0.001; log-rank α=0.05).

CONCLUSION

At least a quarter of HNSCC patients go on to develop a metachronous second primary. These are of poor prognosis, whatever their location.

Sertoli Cells Induce Systemic Donor-Specific Tolerance in Xenogenic Transplantation Model

Cell therapy is a potentially powerful tool in the treatment of many grave disorders including leukemia, immune deficiencies, autoimmune diseases, and diabetes. However, finding matched donors is challenging and recipients may suffer from the severe complications of systemic immune suppression. Sertoli cells, when cotransplanted with both allo- and xenograft tissues, promote graft acceptance in the absence of systemic immunosuppression. How Sertoli cells do this is not, as yet, clearly defined. We have examined the ability of Sertoli cells to produce systemic immune tolerance. For this purpose, Sertoli cells were injected into an otherwise normal C57/BL6 mouse host via the lateral tail vein. No other immunosuppressive protocols were applied. Six to 8 weeks posttransplantation, blood was collected for analysis of cytokine levels. Tolerance to donor cells was determined by mixed lymphocytic culture, and production of T-cell-dependent antibody was determined by an in vitro anti-sheep red blood cell plaque-forming assay. Results showed a marked modulation of immune cytokines in the transplanted mouse host and donor-specific transplantation tolerance was achieved. Tolerant mouse lymphocytes maintained a competent humoral antibody response. Additionally, C57/BL6 mice transplanted with rat Sertoli cells tolerated rat skin grafts significantly longer than control non-Sertoli cell transplanted mice. We conclude that systemic administration of rat Sertoli cells across xenogenic barrier induces transplantation tolerance without altering systemic immune competence. These data suggest that Sertoli cells may be used as a novel and potentially powerful tool in cell transplantation therapy.

Supplementation of arachidonic acid rich oil in European sea bass juveniles (Dicentrarchus labrax) diets: Effects on leucocytes and plasma fatty acid profiles, selected immune parameters and circulating prostaglandins levels

The main objective of this study was to assess the effects of graded levels of dietary arachidonic acid (ARA), supplemented from alternative sources, on fatty acid composition of plasma and head kidney leucocytes of European sea bass (Dicentrarchus labrax). For that purpose, sea bass juveniles were fed four diets containing graded levels of ARA as follows: 0.5% (ARA0.5), 1% (ARA1), 2% (ARA2) and 4% (ARA4) during 60 days. At the end of the feeding trial fatty acid profiles of plasma and head kidney leucocytes were analyzed. Besides, plasma prostaglandins levels, head kidney leucocytes respiratory burst activity; peroxidase activity and phagocytic index were assayed. Reducing dietary ARA levels below 1% markedly reduced European sea bass growth performance. However, fish fed diet ARA0.5 tried to compensate this dietary ARA deficiency by a selective deposition of ARA on plasma and head kidney leucocytes, reaching similar levels to those fish fed diet ARA1 after 60 days of feeding. Nevertheless, head kidney phagocytic capacity was reduced as dietary ARA content in relation not only to variations on membrane composition but also to changes on fish basal prostaglandins levels. Results obtained demonstrated the importance to supply the necessary quantity n-6 LC-PUFA, and not only n-3 LC-PUFA levels, in European sea bass diets, in relation to not only growth performance but also immune system function.

Outcomes and infectious etiologies of febrile neutropenia in non-immunocompromised children who present in an emergency department

There are no unified protocols governing the management of healthy children with febrile neutropenia in the emergency department (ED). Conservative management is the norm, with admission and empirical broad-spectrum antibiotics prescribed, although viral infections are considered the most frequent etiology. The aim of this study was to describe the clinical outcomes and identified etiologies of unsuspected neutropenia in febrile immunocompetent children assessed in the ED. This was a retrospective study: well-appearing healthy children <18 years old with febrile moderate [absolute neutrophil count (ANC) 500-999 neutrophils ×10(9)/l] or severe (ANC <500 neutrophils ×10(9)/l) neutropenia diagnosed in ED between 2005 and 2013 were included. Patients newly diagnosed with hematologic or oncologic disease were excluded. We included 190 patients: 158 (83.2 %) with moderate and 32(16.8 %) with severe neutropenia. One hundred and one (53.2 %) were admitted; 48(47.5 %) with broad-spectrum antibiotics. The median length of stay was 3 days (IQR 3-5) and the median duration of neutropenia was 6 days (IQR 3-12). An infectious agent was identified in 23(12.1 %); 21 (91.3 %) were viruses. Four (2.1 %) children had a serious bacterial infection (SBI): urinary tract infection and lobar pneumonia (two cases each). All blood cultures performed (144; 75.8 %) were negative. Over the 1-year follow-up, one or several blood tests were performed on 167 patients (87.9 %); two (1.2 %) were diagnosed with autoimmune chronic neutropenia. Previously healthy children with moderate or severe febrile neutropenia have a low risk of SBI and a favorable clinical outcome. Less aggressive management could be carried out in most of them. Although chronic hematological diseases are infrequently diagnosed, serial ANC are necessary to detect them.

Epidemiological study of Clostridium difficile infection in critical patients admitted to the Intensive Care Unit

Data on the epidemiology of infections caused by Clostridium difficile (CDI) in critically ill patients are scarce and center on studies with a limited time framework and/or epidemic outbreaks.

OBJECTIVE

To describe the characteristics and risk factors of critically ill patients admitted to the ICU with CDI, as well as the treatments used for the control of such infections.

MATERIAL AND METHODS

A retrospective study was made of patients included in the ENVIN-ICU registry with CDI in 2012. Patients were followed up to 72 h after discharge from the ICU. A case report form was used to record the following data: demographic variables, risk factors related to CDI, treatment and outcome. Infections were classified as community-acquired, nosocomial out-ICU and nosocomial in-ICU, according to the day on which Clostridium difficile isolates were obtained. Infection rates as episodes per 10,000 days of ICU stay are presented. The global in-ICU and hospital mortality rates were calculated.

RESULTS

Sixty-eight episodes of CDI in 33 out of a total of 173 ICUs participating in the registry were recorded (19.1%) (2.1 episodes per 10,000 days of ICU stay). Forty-five patients were men (66.2%), with a mean (SD) age of 63.4 (16.4) years, a mean APACHE II score on ICU admission of 19.9 (7.4), and an underlying medical condition in 44 (64.7%). Sixty-two patients (91.2%) presented more than 3 liquid depositions/day, 40 (58.8%) in association with severe sepsis or septic shock. Community-acquired infection occurred in 13 patients (19.1%), nosocomial out-ICU infection in 13 (19.1%), and in-ICU infection in 42 (61.8%). Risk factors included age>64 years in 39 cases (57.4%), previous hospital admission (3 months) in 32 (45.6%), use of antimicrobials (previous 7 days) in 57 (83.8%), enteral nutrition in 23 (33.8%), and the use of H2 inhibitors in 39 (57.4%). Initial combined treatment was administered to 18 patients (26.5%). Metronidazole was used in 60 (88.2%) and vancomycin in 31 (45.6%). The in-ICU mortality rate was 25.0% (n=17), with a hospital mortality 27.9% (n=19).

CONCLUSIONS

The rate of ICD in ICU patients is low, the infection affects severely ill patients, and is associated with high mortality. The presence of CDI is a marker of poor prognosis.

The EuroPrevall birth cohort study on food allergy: baseline characteristics of 12,000 newborns and their families from nine European countries

It is unclear why some children develop food allergy. The EuroPrevall birth cohort was established to examine regional differences in the prevalence and risk factors of food allergy in European children using gold-standard diagnostic criteria. The aim of this report was to describe pre-, post-natal and environmental characteristics among the participating countries. In nine countries across four major European climatic regions, mothers and their newborns were enrolled from October 2005 through February 2010. Using standardized questionnaires, we assessed allergic diseases and self-reported food hypersensitivity of parents and siblings, nutrition during pregnancy, nutritional supplements, medications, mode of delivery, socio-demographic data and home environmental exposures. A total of 12,049 babies and their families were recruited. Self-reported adverse reactions to food ever were considerably more common in mothers from Germany (30%), Iceland, United Kingdom, and the Netherlands (all 20-22%) compared with those from Italy (11%), Lithuania, Greece, Poland, and Spain (all 5-8%). Prevalence estimates of parental asthma, allergic rhinitis and eczema were highest in north-west (Iceland, UK), followed by west (Germany, the Netherlands), south (Greece, Italy, Spain) and lowest in central and east Europe (Poland, Lithuania). Over 17% of Spanish and Greek children were exposed to tobacco smoke in utero compared with only 8-11% in other countries. Caesarean section rate was highest in Greece (44%) and lowest in Spain (<3%). We found country-specific differences in antibiotic use, pet ownership, type of flooring and baby's mattress. In the EuroPrevall birth cohort study, the largest study using gold-standard diagnostic criteria for food allergy in children worldwide, we found considerable country-specific baseline differences regarding a wide range of factors that are hypothesized to play a role in the development of food allergy including allergic family history, obstetrical practices, pre- and post-natal environmental exposures.

Diagnostic tools assessing airway remodelling in asthma

Asthma is an inflammatory disease of the lower airways characterised by the presence of airway inflammation, reversible airflow obstruction and airway hyperresponsiveness and alterations on the normal structure of the airways, known as remodelling. Remodelling is characterised by the presence of metaplasia of mucous glands, thickening of the lamina reticularis, increased angiogenesis, subepithelial fibrosis and smooth muscle hypertrophy/hyperplasia. Several techniques are being optimised at present to achieve a suitable diagnosis for remodelling. Diagnostic tools could be divided into two groups, namely invasive and non-invasive methods. Invasive techniques bring us information about bronchial structural alterations, obtaining this information directly from pathological tissue, and permit measure histological modification placed in bronchi layers as well as inflammatory and fibrotic cell infiltration. Non-invasive techniques were developed to reduce invasive methods disadvantages and measure airway remodelling-related markers such as cytokines, inflammatory mediators and others. An exhaustive review of diagnostic tools used to analyse airway remodelling in asthma, including the most useful and usually employed methods, as well as the principal advantages and disadvantages of each of them, bring us concrete and summarised information about all techniques used to evaluate alterations on the structure of the airways. A deep knowledge of these diagnostic tools will make an early diagnosis of airway remodelling possible and, probably, early diagnosis will play an important role in the near future of asthma.

Heterogeneous trend in smoking prevalence by sex and age group following the implementation of a national smoke-free law

OBJECTIVE

Given the limited evidence available about the effects of clean indoor air laws on smoking behaviour in the general population, the impact of national smoke-free workplace, bar and restaurant legislation, implemented on 1 January 2006, on smoking prevalence in Spain was assessed in this study.

METHODS

Population-based trend analysis using estimates for 27 periods from the beginning of 2000 to the end of 2008-three periods per year. To calculate the period per cent change in smoking prevalence, the permutation test for joinpoint regression to detect significant changes was used.

RESULTS

In men and women aged 15-24 years, the prevalence of smoking declined between the first period in 2000 and the third period in 2008, whereas in women aged 45-64 years, it increased by 1.7% per period. A declining trend was detected up to the first period in 2006 in men and women aged 25-44 years and in men aged 45-64 years, but between the beginning of 2006 and the end of 2008 the prevalence of smoking increased by 1.2%, 0.7% and 2.0% per period in men aged 25-44 years, in women aged 25-44 years and in men aged 45-64 years, respectively.

CONCLUSIONS

3 years after a national smoke-free law was implemented, the trend in smoking prevalence in some population groups was unchanged; however, in others, the declining trend of previous years was reversed. The similarity of these findings to those observed in other countries suggests that clean indoor air laws, although effective in reducing exposure to second-hand smoke, may not achieve the secondary objective of reducing the prevalence of smoking in the population.

The effect of a partially hydrolysed formula based on rice protein in the treatment of infants with cow's milk protein allergy

Infants diagnosed with allergy to cow's milk protein (CMP) are fed extensively hydrolysed cow's milk formulas, modified soy formulas or even amino acid-based formulas. Hydrolysed rice protein infant formulas have become available and have been shown to be well tolerated by these infants. A prospective open, randomized clinical study to compare the clinical tolerance of a new hydrolysed rice protein formula (HRPF) with an extensively hydrolysed CMP formula (EHF) in the feeding of infants with IgE-mediated cow's milk allergy. Ninety-two infants (46 boys and 46 girls, mean age 4.3 months, range 1.1-10.1 months) diagnosed with IgE-mediated cow's milk allergy were enrolled in the study. Clinical tolerance to the formula products was tested. Clinical evaluation included skin prick tests with whole cow's milk, soya and rice as well as antigens of CMP (beta-lactoglobulin, alpha-lactalbumin, casein and bovine seroalbumin), HRPF and EHF and specific IgE determinations to CMP using CAP technology. Patients were randomized to receive either an EHF based on CMP or a new HRPF. Follow-up was at 3, 6, 12, 18 and 24 months. Growth parameters were measured at each visit. One infant showed immediate allergic reaction to EHF, but no reaction was shown by any infant in the HRPF group. The number of infants who did not become tolerant to CMP during the study was not statistically different between the two groups. Measurement of IgE levels of infants allergic to CMP during the study showed no significant differences between the two formula groups. Growth parameters were in the normal range and similar between groups. In this study, the HRPF was well tolerated by infants with moderate to severe symptoms of IgE-mediated CMP allergy. Children receiving this formula showed similar growth and development of clinical tolerance to those receiving an EHF. In accordance with current guidelines, this HRPF was tolerated by more than 90% of children with CMP allergy and therefore could provide an adequate and safe alternative to CMP-hydrolysed formulas for these infants.

The multinational birth cohort of EuroPrevall: background, aims and methods

BACKGROUND/AIM

The true prevalence and risk factors of food allergies in children are not known because estimates were based predominantly on subjective assessments and skin or serum tests of allergic sensitization to food. The diagnostic gold standard, a double-blind placebo-controlled food provocation test, was not performed consistently to confirm suspected allergic reactions in previous population studies in children. This protocol describes the specific aims and diagnostic protocol of a birth cohort study examining prevalence patterns and influential factors of confirmed food allergies in European children from different regions.

METHODS

Within the collaborative translational research project EuroPrevall, we started a multi-center birth cohort study, recruiting a total of over 12 000 newborns in nine countries across Europe in 2005-2009. In addition to three telephone interviews during the first 30 months, parents were asked to immediately inform the centers about possible allergic reactions to food at any time during the follow-up period.

RESULTS

All children with suspected food allergy symptoms were clinically evaluated including double-blind placebo-controlled food challenge tests. We assessed sensitization to different food allergens by measurements of specific serum immunoglobulin E and skin prick tests, collect blood, saliva or buccal swabs for genetic tests, breast milk for measurement of food proteins/cytokines, and evaluate quality-of-life and economic burden of families with food allergic children.

CONCLUSIONS

This birth cohort provides unique data on prevalence, risk factors, quality-of-life, and costs of food allergies in Europe, leading to the development of more informed and integrated preventative and treatment strategies for children with food allergies.

TGFB1 gene polymorphisms: their relevance in the susceptibility to Helicobacter pylori-related diseases

Recent studies have revealed elevated expression of transforming growth factor beta1 (TGF-beta1) in gastric mucosa of patients with gastric cancer (GC) and those undergoing ulcer repair. As production of TGF-beta1 is genetically regulated, we aimed to assess whether functional polymorphisms of the TGFB1 gene are involved in susceptibility to and clinical characteristics of Helicobacter pylori-related diseases. DNA from 142 unrelated Spanish patients with GC, 200 with peptic ulcer and 342 healthy controls was typed for the MspA1I T+869C, and the Sau96I G+915C polymorphisms of the TGFB1 gene using polymerase chain reaction and RFLP analysis. H. pylori infection and CagA/VacA antibody status were determined by Western blot in patients and controls. H. pylori infection (odds ratio (OR): 11.44; 95% confidence interval (CI): 4.45-29.42; P<0.001) and non-steroidal anti-inflammatory drugs (OR: 5.07; 95% CI: 2.53-10.16; P<0.001) were identified as independent risks factors for duodenal ulcer (DU), whereas the TGFB1+869(*)C/C genotype was associated with reduced risk of developing the disease (OR: 0.32; 95% CI=0.15-0.68; P=0.003). Our results show that the TGFB1 T+869C gene polymorphism is involved in the susceptibility to DU and provide further evidence that host genetic factors play a key role in the pathogenesis of H. pylori-related diseases.

Anisakis simplex allergy after eating chicken meat

BACKGROUND

Allergic reactions to food can be produced by contaminants that induce sensitization. Among these, Anisakis simplex can cause seafood infestation, and allergic symptoms (urticaria-angioedema, anaphylaxis, and asthma) can follow the eating or handling of affected fish. Although seafood is the principal source of human infections by this parasite, we have found allergic symptoms in 8 patients previously diagnosed as having A simplex sensitization after they ate chicken meat. Chicken feed usually has a high proportion of fishmeal, which might possibly be contaminated by this nematode.

OBJECTIVE

The aim of our study was to determine whether parasite proteins present in chicken meat could be responsible for the symptoms reported by these subjects.

METHODS

We carried out in vivo tests (prick, bronchial challenge, and double-blind placebo-controlled challenge with meat chicken) in these 8 patients. We performed immunoblotting using the sera from the 8 patients and controls in order to detect A simplex sensitization. We also investigated the presence of A simplex proteins in sera from chickens fed with fishmeal and in other sera from chickens fed only with cereals. We excluded sensitization to other chicken nematodes by serologic methods.

RESULTS

All 8 patients presented positive prick and challenges to A simplex. When we used serum from chickens fed with fishmeal as the antigen in blotting, patients 3, 4, 5, 6, 7, and 8 recognized a band of 16 kd, also obtained when using pools of fish-shellfish and A simplex larva. No detection was observed with sera from chickens fed with only cereals.

CONCLUSION

We provide evidence, based on in vivo and in vitro tests, that subjects highly sensitized to A simplex can detect the presence of Anisakis species allergens in chicken meat.

Quantitative real-time reverse transcription: polymerase chain reaction of prostate-specific antigen (PSA) for detection of circulating prostatic cells in patients with clinically localized prostate cancer

OBJECTIVE

To evaluate the clinical utility of using the real-time reverse transcriptase-polymerase chain reaction (RT-PCR) to quantify prostate-specific antigen (PSA) mRNA in peripheral blood samples from patients with prostate cancer as a predictor of extraprostatic extension of the disease and to assess any correlations with known predictive markers of this condition.

METHODS

Immediately before radical prostatectomy, peripheral blood samples were taken from 42 men with clinically localized prostate cancer and analysed for PSA and 18S ribosomal (endogenous control) genes using real-time RT-PCR (with gene expression assays and the comparative CT-cycle threshold-method for quantifying). A total of 30 healthy male blood donors aged <50 y was taken as a control group. The relationships between PSA mRNA values, pathological and clinical features were analysed. PSA mRNA value, PSA level and biopsy Gleason score were then compared as predictors of extraprostatic extension.

RESULTS

PSA gene expression was 3.73 times significantly higher in patients with clinically localized prostate cancer than in healthy men (P<0.05). There was no relationship between PSA real-time RT-PCR values and pathological stage pT2 or pT3 (P=0.5), and no association between PSA mRNA value and serum PSA level (P=0.9) or the Gleason score of the preoperative biopsy (P=0.9).

CONCLUSION

There was no significant advantage in using the real-time RT-PCR assay of PSA mRNA before surgery to stage prostate cancer and to discriminate between organ-confined and extraprostatic extension.

Incremento de la diferencia en la supervivencia según la renta per cápita en España en los últimos años del siglo XX

OBJECTIVE

To estimate probability of survival in Spain from 1975 to 1995 according to income per capita quintiles.

METHODS

The 50 provinces in Spain were ordered by income per capita in 1975, 1981, 1985, 1990 and 1995. For each quintile and year we estimated the probability of surviving 75 years from birth and the probability of survival in several age intervals in men and women. Probability was estimated by percentages. Subsequently, we calculated differences in the probability of survival between the highest and the lowest income per capita quintiles.

RESULTS

Differences in the probability of surviving from birth to the age of 75 years increased from 1.3 in 1975 to 3.1 in 1995 in women, whereas in men the increase was from 0.1 in 1975 to 3.7 in 1995.

CONCLUSIONS

In Spain, as in other developed countries, socioeconomic differences in premature mortality increased in the latter decades of the twentieth century.

IgE-binding and cross-reactivity of a new 41 kDa allergen of codfish

BACKGROUND

A 41-kDa IgE-reactive protein (p41) was purified from raw cod extract. This protein is homologous to an aldehyde phosphate dehydrogenase (APDH). The present study aims to evaluate the IgE-binding and the cross-reactivity of this protein in 13 patients allergic to codfish.

METHODS

IgE binding of sera from 13 patients allergic to codfish was tested by Sepharose RIA and by Western blot.

RESULTS

Among the 13 patients, only 4 had specific IgE to APDH detected by APDH-Sepharose RIA. The two patients who had the highest level of specific IgE to human APDH also had a class 5-6 CAP-RAST IgE level to codfish, but two other patients with a class 5 had a negative APDH-Sepharose IgE-RIA. Relative content of APDH was higher in extracts of commercial nonfrozen fish, compared to pre rigor mortis, post rigor mortis and frozen commercial codfish. A high homology of codfish APDH was found with the corresponding human enzyme. A significant inhibition of APDH-Sepharose by human and, to a lesser extent, by rabbit APDH was observed. Western blot of APDH codfish extract showed two bands at 41 and 36 kDa, respectively.

CONCLUSIONS

We have characterized a new allergen from codfish, which had a high level of homology in different species. The p41 relative content of extracts from nonfrozen codfish was higher than in the other samples assessed.

Allergy after ingestion or inhalation of cereals involves similar allergens in different ages

BACKGROUND

Cereals are among the major foods that account for food hypersensitivity reactions. Salt-soluble proteins appear to be the most important allergens contributing to the asthmatic response. In contrast, very limited information is available regarding cereal allergens responsible for allergic reactions after ingestion of cereal proteins.

OBJECTIVE

The aim of this study was to evaluate the allergenic reactivity of ingested and inhaled cereal allergens in different ages, in order to investigate if the response to different allergens would depend on the sensitization route.

METHODS

We included 66 patients in three groups. Group 1: 40 children aged 3 to 6 months who suffered from diarrhoea, vomiting, eczema or weight loss after the introduction of cereal formula in their diet and in which a possibility of coeliac disease was discarded. Group 2: 18 adults with food allergy due to cereals tested by prick tests, specific IgE and food challenge. Group 3: eight patients previously diagnosed as having baker's asthma. Sera pool samples were collected from each group of patients and IgE immunoblotting was performed.

RESULTS

We found an important sensitization to cereal in the 40 children. The most important allergens were wheat followed by barley and rye. Among the adults with cereal allergy, sensitization to other allergens was common, especially to Lolium perenne (rye grass) pollen. Immunoblotting showed similar allergenic detection in the three groups.

CONCLUSION

Clinically significant reactivity to cereal may be observed in early life. Inhalation and ingestion routes causing cereal allergy seem to involve similar allergens. The diet control was more effective in children. The possibility of cereal allergy after the introduction of cereal formula during the lactation period should not be underestimated.

The effect of inoculum size and sublethal injury on the ability of Listeria monocytogenes to initiate growth under suboptimal conditions

AIMS

To investigate the effect of inoculum size and physiological state on the ability of Listeria monocytogenes cells to initiate growth under suboptimal conditions of salt concentration and pH.

METHODS AND RESULTS

Cell suspensions were serially diluted in media of different salt concentration or pH and replicate inocula distributed into 96-well microplates. The proportion of wells showing growth at each dilution level was determined after incubation for 6 weeks for each set of conditions. Growth occurred from single cells up to a concentration of 1.2 mol l-1 NaCl; above this threshold, the inoculum size needed to initiate growth became progressively larger. A similar effect was seen with decreasing pH but only very close to the growth/no growth boundary. The threshold for inoculum-dependent growth was lower in exponential phase cells than in stationary phase ones and sublethal injury greatly decreased the probability of growth from small inocula.

CONCLUSIONS

The growth/no growth boundary for L. monocytogenes is not an absolute cut-off point but represents a region where the probability of growth rapidly decreases as conditions become more extreme. We interpret the requirement for a critical inoculum size for growth as being due to death of a proportion of cells in the inoculum rather than to co-operative population effects.

SIGNIFICANCE AND IMPACT OF THE STUDY

Physiological heterogeneity within the cell population and inoculum size will affect the risk of L. monocytogenes growing in food.

Variation in resistance to high hydrostatic pressure and rpoS heterogeneity in natural isolates of Escherichia coli O157:H7

Several natural isolates of Escherichia coli O157:H7 have previously been shown to exhibit stationary-phase-dependent variation in their resistance to inactivation by high hydrostatic pressure. In this report we demonstrate that loss of the stationary-phase-inducible sigma factor RpoS resulted in decreased resistance to pressure in E. coli O157:H7 and in a commensal strain. Furthermore, variation in the RpoS activity of the natural isolates of O157:H7 correlated with the pressure resistance of those strains. Heterogeneity was noted in the rpoS alleles of the natural isolates that may explain the differences in RpoS activity. These results are consistent with a role for rpoS in mediating resistance to high hydrostatic pressure in E. coli O157:H7.

Inactivation and injury of pressure-resistant strains of Escherichia coli O157 and Listeria monocytogenes in fruit juices

AIMS

To investigate methods for inactivating a pressure-resistant strain of Escherichia coli O157 in fruit juices.

METHODS AND RESULTS

Cells of a pressure-resistant strain of E. coli O157 (C9490) were exposed to pressures of between, 0.1 and 500 MPa for 5 min in orange, apple or tomato juice. Treatment at 500 MPa achieved an immediate reduction of 5 log units in apple juice (pH 3.5) and tomato juice (pH 4.1), but only about a 1-2 log10 reduction in orange juice (pH 3.8). The greater level of inactivation in tomato juice than in orange juice of lower pH was due to the presence of low levels (0.7%) of salt in the tomato juice. With the type-strain of E. coli (ATCC 11775) and Listeria monocytogenes NCTC 11994, similar levels of inactivation were achieved at pressures 200 MPa lower. Following storage of pressure-treated orange juice at 4 degrees C for 24 h or 25 degrees C for 3 h, the level of inactivation of E. coli O157 strain C9490 increased to 4.4 or > 7 log10 units, respectively.

CONCLUSION

Treatment at 500 MPa may be insufficient to achieve a '5D' reduction in counts of pressure-resistant strains of E. coli, but subsequent death during storage substantially increases process lethality.

SIGNIFICANCE AND IMPACT OF THE STUDY

Commercially-practicable pressure processes can be used to inactivate even the most pressure-and acid-resistant strains of E. coli O157, provided that processing and subsequent storage conditions are carefully optimized.

Metabolism and growth of juveniles of Litopenaeus vannamei: effect of salinity and dietary carbohydrate levels

The present study was designed to understand how carbohydrate (CBH) and protein metabolism are related in the penaeid shrimp Litopenaeus vannamei. With this information, we obtained a comprehensive schedule of the protein-carbohydrate metabolism including enzymatic, energetic, and functional aspects. We used salinity to determine its role as a modulator of the protein-carbohydrate metabolism in shrimp. Two experiments were designed. The first experiment evaluated the effect of CBH-salinity combinations in growth and survival, and hemolymph glucose, protein, and ammonia levels, digestive gland glycogen, osmotic pressure, and glutamate dehydrogenase (GDH) of L. vannamei juveniles acclimated during 18 days at a salinity of 15 per thousand and 40 per thousand. The second experiment was done to evaluate the effect of dietary CBH level on pre- and postprandial oxygen consumption, ammonia excretion, and the oxygen-nitrogen ratio (O/N) of juvenile L. vannamei in shrimps acclimated at 40 per thousand salinity. We also evaluated the ability of shrimp to carbohydrate adaptation. We made phosphoenolpyruvate carboxykinase (PECPK) and hexokinase activity measurements after a change in dietary carbohydrate levels at different times during 10 days. The growth rate depended on the combination salinity-dietary CBH-protein level. The maximum growth rate was obtained in shrimps maintained at 15 per thousand salinity and with a diet containing low CBH and high protein. The protein in hemolymph is related to the dietary protein levels; high dietary protein levels produced a high protein concentration in hemolymph. This suggests hemolymph is able to store proteins after a salinity acclimation. Depending on the salinity, the hemolymph proteins could be used as a source of osmotic effectors or as metabolic energy. The O/N values obtained show that shrimp used proteins as a source of energy, mainly when shrimps were fed with low CBH. The role played by postprandial nitrogen excretion (PPNE) in apparent heat increase (AHI) (PPNE/AHI ratio) is lower in shrimps fed diets containing high CBH in comparison with shrimps fed diets containing low CBH levels. These results confirm that the metabolism of L. vannamei juveniles is controlled by dietary protein levels, affecting the processes involved in the mechanical and biochemical transformations of ingested food. A growth depression effect was observed in shrimps fed with low-CBH protein diets and maintained in 40 per thousand salinity. In these shrimps, the hemolymph ammonia concentration (HAC) was significantly higher than that observed in shrimps fed with low CBH and maintained in 15 per thousand salinity. That high HAC level coincided with lower growth rate, which suggests that this level might be toxic for juveniles of L. vannamei. Results obtained for GDH activity showed this enzyme regulated both HAC and hemolymph protein levels, with high values in shrimps fed with low CBH levels and maintained in 40 per thousand salinity, and lower in shrimps fed with high CBH and maintained in 15 per thousand salinity. These differences mean that shrimp with a high-gill GDH activity might waste more energy in oxidation of the excess proteins and amino acids, reducing the energy for growth. It was evident that L. vannamei can convert protein to glycogen by a gluconeogenic pathway, which permitted shrimp to maintain a minimum circulating glucose of 0.34 mg/ml in hemolymph. A high PECPK activity was observed in shrimps fed a diet containing low CBH level indicating that the gluconeogenic pathway is activated, as in vertebrates by low dietary CBH levels. After a change in diet, we observed a change in PEPCK; however, it was lower and seems to depend on the way of adaptation, because it occurred after 6 days when adapting to a high-CBH diet and with little change for the low-CBH diet.

Actinomyces catuli sp. nov., from dogs

An Actinomyces-like bacterium was recovered from two dogs. Based on cellular morphology and biochemical criteria, the unknown bacterium resembled the genus Actinomyces but it did not appear to correspond to any of the currently recognized species of this genus. PAGE analysis of whole-cell proteins confirmed that the strain was phenotypically distinct from all other Actinomyces species and comparative 16S rRNA gene sequencing showed that the bacterium represents an unknown sub-line within the genus. Based on phenotypic and phylogenetic evidence, it is proposed that the bacterium from dogs be classified as a new species of the genus Actinomyces, Actinomyces catuli. The type strain of Actinomyces catuli is CCUG 41709T (= CIP 106507T).

Actinomyces marimammalium sp. nov., from marine mammals

Three strains of a previously undescribed Actinomyces-like bacterium were isolated from samples taken from two dead seals and a porpoise. Biochemical testing and PAGE analysis of whole-cell proteins indicated the strains were phenotypically similar to each other but different from previously described Actinomyces and Arcanobacterium species. Comparative 16S rRNA gene sequencing studies showed the organisms from marine animals were genetically closely related and represent a hitherto unknown subline within the genus Actinomyces (sequence divergence values > 6% with recognized species). Based on phylogenetic and phenotypic evidence it is proposed that the unknown bacterium from the seals and a porpoise should be classified as Actinomyces marimammalium sp. nov. The type strain is CCUG 41710T.

Determination of xanthine oxidoreductase forms: influence of reaction conditions

Xanthine oxidoreductase (XOR) has been implicated in ischaemia-reperfusion injury, and increases in this enzyme have been found in plasma of patients with different illnesses. The catalytic concentrations of the XOR forms found in plasma, using various reaction conditions, greatly differ in the related literature. We studied the effect of the assay conditions on the xanthine oxidation rate catalysed by the XOR forms. Our results demonstrate inhibition of XOR by the reaction products and a time-dependent decrease in the reaction rates of XOR forms. Substrate consumption and inhibition by the products did not account for this decrease. Determination at 60 min incubation leads to catalytic concentrations up to 80% lower for the XOR forms than those obtained at 10 min. We conclude that elimination of the reaction products (NADH, H(2)O(2) and O(2)) from the reaction mixture, and short incubation times, are necessary for accurate measurement of the XOR activities.