Detection of Yersinia enterocolitica in food: an overview.

Yersinia enterocolitica is a gastrointestinal pathogen which causes yersiniosis, an illness characterized by diarrhea, ileitis, and mesenteric lymphadenitis. Y. enterocolitica is transmitted via the feco-oral route by the consumption of contaminated food or water. Several phenotypic and genotypic methods have been developed to reliably detect Y. enterocolitica in food. However, the source of infection of many recently reported foodborne outbreaks remains obscure. The detection of this pathogen in food is a challenging task, since it shares similarities with other enteric bacteria. The presence of other microorganisms in the food samples makes it even more difficult to identify this slow-growing pathogen. Therefore, the present-day emphasis is on the development of sensitive, easily automated methods suitable for in-situ detection, allowing quick and cost-effective characterization of food samples. This review summarizes and compares the currently available cultural, immunological, and molecular methods, particularly in relation to their specific merits or demerits when implemented for the detection of Y. enterocolitica in food.

FTO expression is regulated by availability of essential amino acids.

Genome-wide association studies have revealed that single nucleotide polymorphisms in fat mass and obesity-associated transcript (FTO) are robustly associated with body mass index and obesity. Expression of Fto in the hypothalamic arcuate nucleus is bidirectionally regulated as a function of nutritional status; decreasing following a 48-h fast and increasing after 10-week exposure to a high-fat diet. Here, we utilize an in vitro approach to determine which nutrients could regulate FTO levels at a cellular level. Using mouse and human cell lines, we find that FTO levels are not influenced by serum starvation. We demonstrate, however, that both glucose and total amino-acid deprivation regulates FTO expression. In particular, we have found that FTO mRNA and protein levels are dramatically downregulated by total amino-acid deprivation in mouse hypothalamic N46 cells, mouse embryonic fibroblasts and in human HEK293 cells. The drop rate of Fto mRNA is faster than its rate of natural degradation, pointing to regulation at the transcriptional level, which is reversible upon amino-acid replacement. Strikingly, this downregulation was seen only with essential amino-acid deficiency and not nonessential amino acids. These data suggest that FTO might have a role in the sensing of essential amino-acid availability.

Early amino-acid administration improves preterm infant weight.

OBJECTIVE: Premature infants, especially those born less than 1500 g, often exhibit slow overall growth after birth and lack of early nutritional support may be an important element. We tested the hypothesis that early administration of amino acids (within the first few hours of life) to infants born at less than 1500 g would be associated with fewer infants that were less than the 10th percentile at 36 weeks post-conceptual age than infants that received amino acids after the first 24 h of life. STUDY DESIGN: A prospective intervention of early amino-acid (EAA) supplementation, began before 24 h of life, in preterm infants, <1500 g, was compared to a retrospective cohort of preterm infants receiving late amino-acid (LAA) supplementation, began after 24 h of life. The primary outcome variable was the proportion of infants at less than the 10th percentile at 36 weeks post-conceptual age. RESULT: Fewer infants fell below the 10th percentile (P<0.001) in the EAA group. Furthermore, infants in the EAA groups had significantly greater weight gains than did the LAA group (P<0.003) after adjusting for gestational age and time from birth to discharge. In addition, shorter duration of parenteral nutrition was associated with EAA supplementation (P<0.001). CONCLUSION: A prospective strategy of EAA in preterm infants <1500 g was associated with an improved weight gain, suggesting that nutrition that included amino acids may be critical during the first 24 h of life.

Multilocus variable number tandem repeat analysis as a tool to discern genetic relationships among strains of Yersinia enterocolitica biovar 1A.

AIMS: To identify variable number tandem repeat (VNTR)-containing loci, and to use multilocus VNTR (MLVA) to discern genetic relationships among strains of Yersinia enterocolitica biovar 1A isolated from diverse sources. METHODS AND RESULTS: The whole genome sequence of Y. enterocolitica 8081 was analysed and eight VNTR loci with repeat sizes between 4 and 9 bp, and each containing more than four repeat copies were selected for MLVA typing of 88 strains of Y. enterocolitica. Of these, four loci were polymorphic and generated 26 MLVA genotypes among 81 strains of Y. enterocolitica biovar 1A. MLVA was found to be quite discriminatory (DI = 0.87). Cluster analysis and population modelling using minimum spanning tree (MST) clearly clustered Y. enterocolitica biovar 1A into two major groups. CONCLUSIONS: The MLVA is easy to perform and can be used to discern clonal relationship among strains of Y. enterocolitica. Also the phylogenetic relationships obtained with MLVA genotypes were in good agreement with those established by other typing methods. SIGNIFICANCE AND IMPACT OF THE STUDY: The MLVA method reported is relatively more discriminatory than the other genotyping methods and has the potential to be used as an epidemiological tool for the study of strains of Y. enterocolitica biovar 1A.

Resuscitation room blood alcohol concentrations: one-year cohort study.

OBJECTIVE: To clarify the relationship between presenting clinical condition and blood alcohol concentration (BAC) among adult patients admitted to a resuscitation room (RR) of an emergency department (ED) in order to help guide clinical practice. METHOD: Single-site prospective cohort study of all patients admitted to the RR of an inner-city hospital over a one-year period. The study sample comprised all those aged 16 years and over from whom a blood sample was taken, with BAC (results not known to ED staff), pathology by International Classification of Diseases (ICD) version 10 coding, injury severity score for trauma, return visit to hospital and mortality during the subsequent 6-month period, being recorded. RESULTS: 291 (15%) of 1908 presentations had a positive BAC (ie, BAC >10 mg/100 ml) ranging from 11 to 574 mg/100 ml, of which almost 40% were over 240 mg/100 ml (ICD-10 code Y90.8). In addition to collapse from alcohol/drugs, almost half of those presenting following self-harm or assault had a positive BAC. Those with a positive BAC had a higher rate of ED re-attendance in the following 6 months. 10% of all presentations were due to trauma. CONCLUSION: The following five presentations to the RR are associated with a positive BAC: collapse from alcohol/drugs, self-harm, trauma, gastrointestinal bleeding (ICD-10 code K92.2) and non-cardiac chest pain (ICD-10 code R07). Patients with a positive BAC demonstrate a very wide range of pathology, some with severe levels of misuse. This highlights the opportunity for prompt feedback when sober, to ensure all is done to encourage patients to contemplate change in order to reduce re-attendance.

Nutrient sensing in the mTOR/S6K1 signalling pathway.

Nutrient overload induces constitutive S6K1 (S6 kinase 1) activation, which leads to insulin resistance by suppressing insulin-induced class I PI3K (phosphoinositide 3-kinase) signalling [Um, Frigerio, Watanabe, Picard, Joaquin, Sticker, Fumagalli, Allegrini, Kozma, Auwerx and Thomas (2004) Nature 431, 200-205]. This finding gave rise to the question of the mechanism by which nutrients, such as AAs (amino acids), enter the mTOR (mammalian target of rapamycin)/S6K1 signalling pathway. Counter to the prevailing view, our recent studies have shown that the AA input into the mTOR/S6K1 signalling pathway is not mediated by the tumour suppressor TSC1 (tuberous sclerosis complex 1)/TSC2 or its target, the proto-oncogene Rheb (Ras homologue enriched in brain). Instead, we found that the AA input was mediated by class 3 PI3K, or hVps34 (human vacuolar protein sorting 34). In brief, ectopic expression of hVps34 drives S6K1 activation, but only in the presence of AAs, and this effect is blocked by small interfering RNAs directed against hVps34. Moreover, stimulation of cells with AAs increases hVps34 activity, as indicated by the production of PI3P (phosphatidylinositol 3-phosphate). PI3P mediates the recruitment of proteins containing FYVE (Fab1p, YOTB, Vac1p and EEA1) or PX (Phox homology) domains to endosomal membranes, with PI3P-rich micro-domains acting as signalling platforms. Additional evidence indicating hVps34 as the mediator of AA input to S6K1 came from experiments in which S6K1 activation was attenuated by ectopic expression of a cDNA containing two FYVE domains, which bind to PI3P, preventing binding of proteins containing either FYVE or PX domains [Nobukuni, Joaquin, Roccio, Dann, Kim, Gulati, Byfield, Backer, Natt, Bos, Zwartkruis and Thomas (2005) Proc. Natl. Acad. Sci. U.S.A. 102, 14238-14243].

Indentation modulus of the alveolar process in dogs.

One mechanism of bone adaptation is alteration in tissue level material properties. We hypothesized that alteration in the indentation modulus of the alveolar process is an adaptive response to the localized mechanical environment. Forty-eight specimens representing anterior and posterior regions of the maxilla and mandible were obtained from 6 mature male beagle dogs. The indentation properties of the alveolar bone proper and more distant osteonal cortical bone were estimated. The bone types were further divided into 3 regions (coronal, middle, and apical), with 27 indents being made in each region of tooth-supporting bone. There was a significant difference (p < 0.001) in the indentation moduli of the jaws (maxilla/mandible), location (anterior/posterior), and bone type (alveolar bone proper vs. cortical bone). However, statistical interactions exist which preclude the simple interpretation of results. The distribution of relative stiffness provides a better understanding of bone adaptations in the alveolar process.

Vitamin B12 deficiency: a clinical and electrophysiological profile.

OBJECTIVE: The present study was conducted to evaluate the clinical and electrophysiological profile of vitamin B12 deficiency syndrome and whether a correlation exists between the disease process and the various electrophysiological parameters. METHODS: 40 patients with vitamin B12 deficiency neurological syndromes with low serum vitamin B12 and high homocysteine levels were subjected to a detailed motor and sensory nerve conduction studies and pattern reversal VER (P100), SSEP (P37) after stimulation of the posterior tibial nerve and median nerve (N 20) were obtained bilaterally. MR cervical spine was done in all the patients and MR brain in those who presented with neuro-psychiatric symptoms. The patients were followed up at three months, six months and one year after treatment. RESULTS: On the basis of clinico-electrophysiological profile, 31 patients had myeloneuropathy, 5 isolated myelopathy, 4 isolated neuropathy. Four of the patients with myeloneuropathy, had concomitant dementia. MR imaging revealed abnormality in 12.5% of cases. Prolongation of P37 latency was observed in 39 (97.5%) patients, N 20 latency in 22 (55%), and P100 latency in 19 (47.5%) patients. Peripheral neuropathy was seen in 18 patients; optic neuropathy in 8; and combination of peripheral and optic neuropathy in 9 patients. The peripheral neuropathy was axonal in 19, and demyelinating in 6 patients. There was a significant correlation of the duration of the disease with N 20 latency (P < 0.04). Serum vitamin B12 level correlated well with the latencies of P37 (P < 0.005) and sural SNAP (P < 0.006). On treatment, normalization of P100, MRI signal, N 20 and partial recovery of P37 latencies was seen at 6 months, 9 months and one year respectively. CONCLUSION: Differential recovery of central and peripheral syndromes was seen. This correlated with the underlying demyelinating and axonal processes, which was well reflected by the electrophysiological studies, and has an important bearing on the outcome.

Stroke: a rare presentation of cardiac hydatidosis.

A 13-year-old boy presented with acute stroke leading to right-sided hemiparesis. A contrast CT scan of the brain showed a hemorrhagic infarct in the left basal ganglia region with surrounding edema. Echocardiography showed a hydatid cyst in the right atrial chamber extending into the left atrium. A single hepatic hydatid was also seen.

Gastric adenocarcinoma with a yolk sac component: a case report and review of the literature.

Gastric yolk sac tumors (YST) are very rare and are mainly reported in elderly people. We present a case of a 36-year-old man with a poorly differentiated gastric cancer showing a mixture of adenocarcinoma and yolk sac tumor that metastasized to Virchow's node. Both biopsies, Virchow's node and gastric tumor, contained areas of adenocarcinoma and yolk sac tumor that stained strongly positive for alpha fetoprotein (AFP) by the immunohistochemistry method. A high level of serum AFP (38,200 ng/mL) was also noted in this case. The response to chemotherapy in this case of mixed gastric yolk sac tumor and adenocarcinoma was not as favorable as would be expected in a pure primary germ cell tumor.

Ultrastructural changes in the chick thymus following unilateral vagotomy.

The ultrastructure of the thymus in the chick (Gallus domesticus) was studied after unilateral vagotomy at survival times of 3, 7 and 10 days. Ultrastructural changes in the ipsilateral thymus were observed in axon boutons as well as in myoid and cystic cells in the medulla, especially those situated near the corticomedullary junction. Structural changes in axon boutons ranged from granular degeneration of the axonal cytoskeleton to vacuolation of the axoplasm. Myelin figures of different sizes and configurations and clumping of small agranular vesicles were commonly observed in the axon terminals. Degeneration of myoid cells appeared to peak at 7 days post-vagotomy. Changes ranged from oedematous appearance and intense vacuolation of the peripheral cytoplasm to disorganisation and clumping of myofibrils. In some myoid cells the sarcomeres showed granular degeneration at the I-bands and in others, the myofibrils were completely degenerated such that amorphous material and partially degenerated organelles filled the entire cell. The majority of cystic cells at 3 days post-vagotomy showed a uniform increase in electron density. Numerous electron dense bodies, some displaying concentric lamellation, were observed throughout the expanse of the cytoplasm. At 7 days post-vagotomy, the cytoplasm of some cells gave a "moth-eaten" appearance. Dying cystic cells were encountered at 10 days after vagotomy. Degeneration in the myoid and cystic cells suggests that these cellular components may be the putative targets of the vagal fibres in the chick thymus. The changes in these cells reflect a disturbance in the cell metabolism presumably brought about by the removal of vagal influence.

Comparative efficacy and tolerability of nimesulide and piroxicam in osteoarthritis with specific reference to chondroprotection: a double blind randomised study.

The aim of the study was to assess the efficacy, tolerability and chondroprotection afforded by nimesulide, a selective cyclooxygenase-2 inhibitor and piroxicam in a randomised, double blind, controlled clinical trial in 90 patients suffering from osteoarthritis of the knee joint. A significant improvement in the osteoarthritis severity index at 2 weeks (p < 0.01) and an improvement in physicians assessment of global arthritic condition at 4 weeks (p < 0.01) was seen with both the treatments. A significant decrease in articular index of joint tenderness (p < 0.05) at 8 weeks and in self assessment of handicap at 4 weeks (p < 0.05), in comparison to baseline, was observed only in patients receiving nimesulide. Rescue therapy was required by a greater percentage of patients being administered piroxicam. Functional capacity improved in 64% of the patients on nimesulide and 74.5% of the patients receiving piroxicam. Adverse effects were observed in 6 patients on nimesulide and 9 patients receiving piroxicam. No significant difference was found in any of the efficacy and tolerability parameters between the two treatment groups. Magnetic resonance imaging evaluation of the knee joint of 10 patients showed no significant change in the articular cartilage and associated joint structures after 6 months of therapy with both the treatments. The results show that nimesulide and piroxicam are comparable in efficacy and tolerability in patients suffering from osteoarthritis.

Effect of whole-body vibration on the low back. A study of tractor-driving farmers in north India.

STUDY DESIGN: A retrospective cohort study of tractor-driving farmers (study group) and non-tractor-driving farmers (control group) matched for age, gender, generic/ethnic group, land-holding, and work routines. OBJECTIVES: To determine, using magnetic resonance imaging and clinical investigations, the effect of whole-body vibrations on the back in tractor-driving farmers. SUMMARY OF BACKGROUND DATA: Low back pain and pathologic changes in the lower backs of tractor drivers have been reported. However, no study with a control group matched for work-related risk factors has been reported. METHODS: Fifty tractor-driving farmers were compared with 50 non-tractor-driving farmers matched for age, gender, ethnic group, land-holding, and work routine. Both groups were interviewed for details of work routine, assets held, family profile, and vibration exposure to assess the influence of these parameters on signs and symptoms of backache. Magnetic resonance imaging was done to assess the effect of exposure on whole-body vibration and degenerative changes in the back. Vibration measurements also were done on tractors to observe the actual severity of the vibrations. RESULTS: Regular work-related backache was more common among tractor-driving farmers (40%) than among non-tractor-driving farmers (18%, P = 0.015). Anthropometric evaluation showed abdominal girth and weight to be significantly higher in tractor-driving farmers (P = 0.006 and 0.046, respectively), whereas while height and arm span were similar between the two groups. Clinical examination for evidence of disc or facet degeneration showed no difference between the two groups. Evaluation of magnetic resonance images of tractor-driving farmers and non-tractor-driving farmers by an orthopedic surgeon, radiologist, and neurosurgeon showed degenerative changes to be similar between the two groups (P > 0.050). CONCLUSIONS: Tractor-driving farmers report backache more often than non-tractor-driving farmers, but no significant objective differences on clinical or magnetic resonance imaging evaluation were found between the two groups.