A protease and a lipoprotein jointly modulate the conserved ExoR-ExoS-ChvI signaling pathway critical in Sinorhizobium meliloti for symbiosis with legume hosts.

Sinorhizobium meliloti is a model alpha-proteobacterium for investigating microbe-host interactions, in particular nitrogen-fixing rhizobium-legume symbioses. Successful infection requires complex coordination between compatible host and endosymbiont, including bacterial production of succinoglycan, also known as exopolysaccharide-I (EPS-I). In S. meliloti EPS-I production is controlled by the conserved ExoS-ChvI two-component system. Periplasmic ExoR associates with the ExoS histidine kinase and negatively regulates ChvI-dependent expression of exo genes, necessary for EPS-I synthesis. We show that two extracytoplasmic proteins, LppA (a lipoprotein) and JspA (a lipoprotein and a metalloprotease), jointly influence EPS-I synthesis by modulating the ExoR-ExoS-ChvI pathway and expression of genes in the ChvI regulon. Deletions of jspA and lppA led to lower EPS-I production and competitive disadvantage during host colonization, for both S. meliloti with Medicago sativa and S. medicae with M. truncatula. Overexpression of jspA reduced steady-state levels of ExoR, suggesting that the JspA protease participates in ExoR degradation. This reduction in ExoR levels is dependent on LppA and can be replicated with ExoR, JspA, and LppA expressed exogenously in Caulobacter crescentus and Escherichia coli. Akin to signaling pathways that sense extracytoplasmic stress in other bacteria, JspA and LppA may monitor periplasmic conditions during interaction with the plant host to adjust accordingly expression of genes that contribute to efficient symbiosis. The molecular mechanisms underlying host colonization in our model system may have parallels in related alpha-proteobacteria.

Pfizer-BioNTech vaccine induces the production of cross-reactive antibodies against Trypanosoma cruzi proteins: A preliminary study.

OBJECTIVE: To evaluate the presence of cross-reactivity by anti-severe acute respiratory syndrome coronavirus 2 antibodies induced by the Pfizer-BioNTech vaccine against Trypanosoma cruzi proteins in a screening test. METHODS: Forty-three serum samples were obtained from personnel at the Hospital General Naval de Alta Especialidad in Mexico City who received one or two doses of the vaccine and were tested for T. cruzi infection using four tests: two 'in house' enzyme-linked immunosorbent assays (ELISAs), a commercial ELISA diagnostic kit and an immunoblot test. RESULTS: IgG antibodies against the T. cruzi proteins were present in the serum of unvaccinated subjects and subjects who had received one or two doses of the vaccine. The positivity of the samples against T. cruzi was ruled out by means of a Western Blot assay, where all samples were negative for T. cruzi. CONCLUSION: The data suggest that people convalescing from coronavirus disease 2019 and those who received the Pfizer-BioNTech vaccine exhibit cross-reactive antibodies against T. cruzi antigens in ELISA assays.

Colostrum IgA1 antibodies recognize antigens from Helicobacter pylori and prevent cytoskeletal changesin human epithelial cells.

Helicobacter pylori is a Gram-negative bacterium found on the luminal surface of the gastric mucosa in at least 50% of the world's human population. The protective effect of breastfeeding against H. pylori infection has been extensively reported; however, the mechanisms behind this protection remain poorly understood. Human IgA from colostrum has reactivity against H. pylori antigens. Despite that IgA1 and IgA2 display structural and functional differences, their reactivity against H. pylori had not been previously determined. We attested titers and reactivity of human colostrum-IgA subclasses by ELISA, immunoblot, and flow cytometry. Colostrum samples from healthy mothers had higher titers of IgA; and IgA1 mostly recognized H. pylori antigens. Moreover, we found a correlation between IgA1 reactivity and their neutralizing effect determined by inhibition of cytoskeletal changes in AGS cells infected with H. pylori. In conclusion, colostrum-IgA reduces H. pylori infection of epithelial gastric cells, suggesting an important role in preventing the bacteria establishment during the first months of life. As a whole, these results suggest that IgA1 from human colostrum provides protection that may help in the development of the mucosal immune system of newborn children.

Effective Michelson interference observed in fiber-optical analogue of Hawking radiation.

We experimentally observe the stimulated analogue of Hawking radiation produced in a photonic-crystal fiber, with a pulsed pump and a continuous-wave probe. In particular, we propose and demonstrate an innovative method to boost the efficiency and probe the coherence characteristics of the analogue Hawking effect relying on a double pump pulse with a controlled temporal delay. We show that the emitted analogue Hawking radiation corresponds to the coherently-added, interfering Hawking signals resulting from the probe interacting with each pump pulse. We introduce a simple effective Michelson interference model, and demonstrate excellent agreement between our experimental data and the predictions derived from this model. Importantly, while naively increasing the pump power in an attempt to boost the Hawking-radiation generation efficiency results in the distortion of the output signal, we show that at the maxima of the observed Hawking-signal interference pattern, the signal can be increased by a factor of >3 (up to 4 under ideal experimental conditions). This approach could be extended to the use of sequences of m pulses, resulting in a Hawking-signal enhancement of m2.

Experimental Study of the Validity of Entangled Two-Photon Absorption Measurements in Organic Compounds.

Entangled two-photon absorption (ETPA) has recently become a topic of lively debate, mainly due to the apparent inconsistencies in the experimentally reported ETPA cross sections of organic molecules obtained by a number of groups. In this work, we provide a thorough experimental study of ETPA in the organic molecules Rhodamine B (RhB) and zinc tetraphenylporphirin (ZnTPP). Our contribution is 3-fold: first, we reproduce previous results from other groups; second, we on the one hand determine the effects of different temporal correlations─introduced as a controllable temporal delay between the signal and idler photons to be absorbed─on the strength of the ETPA signal, and on the other hand, we introduce two concurrent and equivalent detection systems with and without the sample in place as a useful experimental check; third, we introduce, and apply to our data, a novel method to quantify the ETPA rate based on taking into account the full photon-pair behavior rather than focusing on singles or coincidence counts independently. Through this experimental setup we find that, surprisingly, the purported ETPA signal is not suppressed for a temporal delay much greater than the characteristic photon-pair temporal correlation time. While our results reproduce the previous findings from other authors, our full analysis indicates that the signal observed is not actually due to ETPA but simply to linear losses. Interestingly, for higher RhB concentrations, we find a two-photon signal that, contrary to expectations, likewise does not correspond to ETPA.

An Overview on Irreversible Port-Hamiltonian Systems.

A comprehensive overview of the irreversible port-Hamiltonian system's formulation for finite and infinite dimensional systems defined on 1D spatial domains is provided in a unified manner. The irreversible port-Hamiltonian system formulation shows the extension of classical port-Hamiltonian system formulations to cope with irreversible thermodynamic systems for finite and infinite dimensional systems. This is achieved by including, in an explicit manner, the coupling between irreversible mechanical and thermal phenomena with the thermal domain as an energy-preserving and entropy-increasing operator. Similarly to Hamiltonian systems, this operator is skew-symmetric, guaranteeing energy conservation. To distinguish from Hamiltonian systems, the operator depends on co-state variables and is, hence, a nonlinear-function in the gradient of the total energy. This is what allows encoding the second law as a structural property of irreversible port-Hamiltonian systems. The formalism encompasses coupled thermo-mechanical systems and purely reversible or conservative systems as a particular case. This appears clearly when splitting the state space such that the entropy coordinate is separated from other state variables. Several examples have been used to illustrate the formalism, both for finite and infinite dimensional systems, and a discussion on ongoing and future studies is provided.

Modelling cost-effectiveness of syphilis detection strategies in prisoners: exploratory exercise in a Chilean male prison.

BACKGROUND: Syphilis, together with other sexually transmitted infections, remains a global public health problem that is far from controlled. People deprived of liberty are a vulnerable population. Control activities in prisons rely mostly on passive case detection, despite the existence of affordable alternatives that would allow switching to active case-finding strategies. Our objective was to develop a mathematical modelling framework for cost-effectiveness evaluation, from a health system perspective, of different approaches using rapid tests for the detection of syphilis in inmates' populations and to explore the results based on a Chilean male prison population. METHODS: A compartmental model was developed to characterize the transmission dynamics of syphilis inside a prison with the ongoing strategy (passive case detection, with VRDL + FTA-ABS), considering the entrance and exit of inmates over a 40 year period. The model allows simulation of the implementation of a reverse algorithm for the current situation (rapid test + VDRL), different screening strategies (entry point, massive periodically; both with rapid test + VDRL) and treatment of detected cases. The parameters for the exploratory exercise were obtained from systematic searches of indexed and grey literature and field work (EQ-5D questionnaire application and key actors interviews). Probabilistic sensitivity analysis was conducted to account for uncertainty in relevant parameters. RESULTS: The proposed framework allows the evaluation of different detection strategies. In this study, all the strategies were cost-effective in the baseline scenario when considering an ICER threshold of 1 Chilean GDP per capita (US$15,000). The strategies most likely to be cost-effective (over 80% probability) were: current situation with reverse algorithm, entry point screening and mass screening every two years; the latter was the most effective, achieving the lowest prevalence (0.7% and 1.7% over the period versus the 3% prevalence in the current situation). CONCLUSIONS: Mathematical modelling that considers the performance of different tests and detection strategies could be a useful tool for decision making. The exploratory results show the efficiency of adopting both the use of the rapid tests and performing active case detection to significantly reduce the burden of syphilis in Chilean prisons in the near future.

CD38 Correlates with an Immunosuppressive Treg Phenotype in Lupus-Prone Mice.

CD38 is a transmembrane glycoprotein expressed by T-cells. It has been reported that patients with systemic lupus erythematosus (SLE) showed increased CD38+CD25+ T-cells correlating with immune activation and clinical signs. Contrariwise, CD38 deficiency in murine models has shown enhanced autoimmunity development. Recent studies have suggested that CD38+ regulatory T-cells are more suppressive than CD38- regulatory T-cells. Thus, we have suggested that CD38 overexpression in SLE patients could play a role in regulating immune activation cells instead of enhancing it. This study found a correlation between CD38 with FoxP3 expression and immunosuppressive molecules (CD69, IL-10, CTLA-4, and PD-1) in T-cells from lupus-prone mice (B6.MRL-Faslpr/J). Additionally, B6.MRL-Faslpr/J mice showed a decreased proportion of CD38+ Treg cells regarding wild-type mice (WT). Furthermore, Regulatory T-Cells (Treg cells) from CD38-/- mice showed impairment in expressing immunosuppressive molecules and proliferation after stimulation through the T-cell receptor (TCR). Finally, we demonstrated an increased ratio of IFN-γ/IL-10 secretion in CD38-/- splenocytes stimulated with anti-CD3 compared with the WT. Altogether, our data suggest that CD38 represents an element in maintaining activated and proliferative Treg cells. Consequently, CD38 could have a crucial role in immune tolerance, preventing SLE development through Treg cells.

Frontline Nurse Feedback During the Development of a System to Track Cleaning of Portable Medical Equipment.

As part of the development and testing of an innovative technology for tracking disinfection of portable medical equipment, end-user feedback was obtained during an initial trial on two acute care hospital units. The disinfection tracking device was installed on the computers-on-wheels and vital signs machines. Each device had the capability of detecting a cleaning event, reporting the event to an online database, and displaying the time since last cleaning event on a visual display. End-user feedback regarding functionality, usefulness of information provided, and impact on workflow was obtained by survey and facilitated group discussions. Seventeen frontline nurses completed the anonymous survey, and 22 participated in the facilitated group discussions. End users found the system functionally easy to use and the information about time since last cleaning useful and reported minimum disruption of workflow. Functionality of the system was confirmed by consistency between recorded and self-reported cleaning patterns. Managers found the data on cleaning of portable medical equipment helpful in validating compliance with hospital equipment cleaning policy. Frontline staff expressed appreciation for technology that helps them and improves outcomes but also discussed concerns about the potential for technology that creates extra work and disruption in the busy frontline nursing care delivery environment. Nurses were appreciative of opportunities to provide feedback and input into efforts to develop and introduce technology. Recorded cleaning events coincided with self-reported equipment cleaning patterns and illustrated that the device efficiently collects information deemed useful by the end user.

Interactions Between Diet Quality and Interleukin-6 Genotypes Are Associated With Metabolic and Renal Function Parameters in Mexican Patients With Type 2 Diabetes Mellitus.

OBJECTIVE: The aim of this study was to evaluate the interaction between diet quality and interleukin (IL)-6 genotypes and its association with metabolic and renal function parameters in Mexican patients with type 2 diabetes mellitus (T2DM). DESIGN AND METHODS: Using an analytical cross-sectional design, 219 patients with T2DM (92 men; age 62 ± 10 years) were evaluated for selected metabolic and renal function parameters. Diet quality according to the Healthy Eating Index was evaluated and classified as good diet or poor diet in all patients. IL-6 serum concentrations and genotypes and haplotypes for IL6-597G > A (rs180097), -572G > C (rs180096), and -174G > C (rs180095) polymorphisms were determined. RESULTS: Eighty-two percent of patients reported having a poor diet. Carriers of alleles -572C and -174C showed higher high-density lipoprotein cholesterol levels (44 ± 12 vs. 40 ± 9 mg/dL; P = .01) and lower total cholesterol levels (184 ± 33 vs. 197 ± 42 mg/dL; P = .03) than did those homozygous for G/G. Neither IL6 genotypes nor haplotypes were significantly associated with serum concentrations of IL-6. Some significant interactions between IL6 genotypes/haplotypes and diet quality were associated with body mass index, waist circumference, high-density lipoprotein cholesterol levels, and estimated glomerular filtration rate. CONCLUSIONS: Interactions between diet quality and IL6 genotypes/haplotypes were associated with the main metabolic and renal function parameters in Mexican patients with T2DM. It will be important to consider genetic profiles in designing dietary portfolios and nutritional interventions for the management of such patients.

Prevalence of ß-Lactam Drug-Resistance Genes in Escherichia coli Contaminating Ready-to-Eat Lettuce.

Thirty-four Escherichia coli isolates from 91 ready-to-eat lettuce packages, obtained from local supermarkets in Northern California, were genotyped by multilocus sequence typing, tested for susceptibility to antimicrobial agents, and screened for ß-lactamase genes. We found 15 distinct sequence types (STs). Six of these genotypes (ST1198, ST2625, ST2432, ST2819, ST4600, and ST5143) have been reported as pathogens found in human samples. Twenty-six (76%) E. coli isolates were resistant to ampicillin, 17 (50%) to ampicillin/sulbactam, 8 (23%) to cefoxitin, and 7 (20%) to cefuroxime. blaCTX-M was the most prevalent ß-lactamase gene, identified in eight (23%) isolates. We identified a class A broad-spectrum ß-lactamase SED-1 gene, blaSED, reported by others in Citrobacter sedlakii isolated from bile of a patient. This study found that fresh lettuce carries ß-lactam drug-resistant E. coli, which might serve as a reservoir for drug-resistance genes that could potentially be transmitted to pathogens that cause human infections.

Regulatory IFN-γ-producing killer dendritic cells are enhanced in B6.MLR-Faslpr /J lupus-prone mice.

A novel cell population denominated IFN-γ-producing killer dendritic cells (IKDCs) have been recently described. These cells are lymphocytes lacking B- or T- receptors, but they can be identified by the presence of B220+ CD38+ CD49b+ and low CD11c, among other cell surface markers. The main characteristics of IKDCs are the production of IFN-γ and the ability to spontaneously kill tumor cells. We found that this population increases in B6.MLR-Faslpr /J mice. Interestingly, IKDCs increase with age and are more abundant in mice older than 6 months onward. To analyze whether these cells have any role in the induction of the lupus-like phenotype in the B6.MLR-Faslpr /J mice, IKDCs were purified and transferred into 6-month-old B6.MRL-Faslpr /J mice, then the presence of anti-nuclear antibodies (ANAS) and anti-dsDNA antibodies were analyzed 2 and 4 months after the transfer. The results showed a reduction in the levels of these autoantibodies and increased survival of these mice, indicating that these cells may have a regulatory function. In vitro assays demonstrated that IKDCs reduced the proliferation of both autoreactive B and T cells, suggesting that these may be the mechanisms used by these cells to ameliorate the lupus-like phenotype in the B6.MRL-Faslpr /J mice.

Direct observation of OAM correlations from spatially entangled bi-photon states.

We present spatially-resolved observations of orbital angular momentum (OAM) conservation, via a Laguerre-Gauss (LG) basis decomposition, of spatially-entangled photon pairs produced in type-I collinear spontaneous parametric downconversion (SPDC). These results were obtained with a novel detection system for OAM-entangled photon pairs that combines a projective measurement for the signal photon to a specific value of the azimuthal index ls, with a spatially-resolved measurement for the idler photon using an intensified charge coupled (ICCD) camera. In combination with far-field diffraction of the idler photon through a triangular aperture, we are able to obtain: i) the spatial structure of the heralded idler photon, as governed by the user-selected topological charge of the signal photon; ii) the OAM spectrum; and iii) the topological charge (both magnitude and sign) for the heralded idler photon.

Frequency and Risk Factors of Kidney Alterations in Children and Adolescents who Are Overweight and Obese in a Primary Health-care Setting.

OBJECTIVE: Obesity is clearly associated to kidney disease in adult population; however, there is scarce evidence in children and adolescents. The aim was to compare frequency of renal damage according to the presence of overweight-obesity in children and adolescents, as well as to compare nutritional and biochemical risk factors, according to the presence of kidney alterations. METHODS: Cross-sectional study; 172 children and adolescents, 6-16 years old, without malnutrition, diabetes mellitus, hypertension and independent comorbid conditions associated to obesity or kidney disease, as well as transitory causes of microalbuminuria (MA) from a Primary Health-Care Unit were included. Clinical, biochemical, anthropometric and dietetic evaluations were measured in all subjects; subsequently they were classified as normal weight, overweight and obesity groups according to sex- and age-adjusted body mass index (BMI). Glomerular filtration rate (GFR, estimated by Schwartz equation) and albuminuria (albumin/creatinine ratio) were determined. Presence of kidney alterations was measured as decreased GFR (<90 mL/min/1.73m2), hyperfiltration (>170 mL/min/1.73m2) and MA (30-300 mg/g). RESULTS: Compared with controls, subjects with overweight-obesity had significantly (P<.05) abdominal obesity (0 vs 69%), hypertension (19 vs 26%), hypertriglyceridemia (11 vs 47%), high low-density lipoprotein cholesterol (2 vs 8%) and low high-density lipoprotein cholesterol (HDL-cholesterol; 2 vs 28%), hyperuricemia (11 vs 28%) and hyperinsulinemia (8 vs 70%). Hyperfiltration and MA were present in 5 and 4 subjects with overweight/obesity, respectively, whereas decreased GFR was present in only 1 subject with obesity. Normal weight subjects had no kidney alterations. In multivariate analysis, kidney alterations were significantly predicted by higher BMI and lower HDL-cholesterol. CONCLUSIONS: Kidney alterations were observed only in subjects with overweight (3.6%) and obesity (9.9%), who additionally, displayed cardiometabolic and kidney disease risk factors more frequently than normal weight subjects.

Prevalence of Pica in Patients on Dialysis and its Association With Nutritional Status.

OBJECTIVE: Pica could be strongly implicated in nutritional status of patients on dialysis; however, very scarce data are currently available. The objective of this study was to evaluate the prevalence of pica and its association with nutritional status in dialysis patients. DESIGN AND METHODS: This is a cross-sectional study in a tertiary care teaching hospital. Four-hundred patients on dialysis, without previous pica diagnosis or transplant, pregnancy, mental illness, or infection, were included in the study. Pica, according to the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, was classified as no pica, ice pica, or hard pica. Dialysis Malnutrition Score, 24-hour dietary recall, and biochemical measurements were obtained from patients. As part of statistical analysis, point prevalence and 95% confidence interval of pica were calculated. Comparisons between groups were performed by means of analysis of variance, Kruskal-Wallis test, χ2, or Fisher exact tests, as appropriate. A multivariate analysis was performed by multinomial logistic regression. RESULTS: Prevalence of pica was 42% (ice pica, 46%; soil, 29%; two substances, 14%; red brick, 5%; paper, 3%; soap, 2%; and cattle pasture, 1%). Comparing patients with pica (hard pica and ice pica) versus no pica, subjects with pica were of younger age (25 ± 7, 27 ± 9, 30 ± 11 years, respectively), were more frequently educated <9 years (57%, 46%, 30%, respectively), and had longer dialysis duration (36 ± 19, 32 ± 18, 27 ± 16 months, respectively). Patients with pica achieved the recommended calorie and macronutrients intake target less frequently than those without pica (40-64% vs. 66-77%, P <.05). Malnutrition was present in 74% of the whole sample: (1) 67% in no pica group, (2) 80% in ice pica group, and (3) 89% in hard pica group (P = .001). In the multivariate analysis (R2, 0.27; P < .0001), malnutrition, C-reactive protein, and lower educational level significantly predicted both ice and hard pica. CONCLUSIONS: A worse nutritional status was observed in patients with pica, who additionally were younger, had lower educational level, longer dialysis duration, and worse macronutrient intake routine than patients without pica. Malnutrition, C-reactive protein, and lower educational level significantly predicted both ice and hard pica.

Giant hepatobiliary cystadenoma: clinic-pathological findings.

Hepatic mucinous cystic neoplasms represent a challenging pathology due to their very low frequency, insidious presentation and unclear demography due to the limited cases reported to date. Surgical treatment is mandatory when possible to prevent recurrence and malignant transformation. The case presented herein has a peculiarity, mainly an increased level of CA 19-9 which has not been previously reported.

IscR is essential for yersinia pseudotuberculosis type III secretion and virulence.

Type III secretion systems (T3SS) are essential for virulence in dozens of pathogens, but are not required for growth outside the host. Therefore, the T3SS of many bacterial species are under tight regulatory control. To increase our understanding of the molecular mechanisms behind T3SS regulation, we performed a transposon screen to identify genes important for T3SS function in the food-borne pathogen Yersinia pseudotuberculosis. We identified two unique transposon insertions in YPTB2860, a gene that displays 79% identity with the E. coli iron-sulfur cluster regulator, IscR. A Y. pseudotuberculosis iscR in-frame deletion mutant (ΔiscR) was deficient in secretion of Ysc T3SS effector proteins and in targeting macrophages through the T3SS. To determine the mechanism behind IscR control of the Ysc T3SS, we carried out transcriptome and bioinformatic analysis to identify Y. pseudotuberculosis genes regulated by IscR. We discovered a putative IscR binding motif upstream of the Y. pseudotuberculosis yscW-lcrF operon. As LcrF controls transcription of a number of critical T3SS genes in Yersinia, we hypothesized that Yersinia IscR may control the Ysc T3SS through LcrF. Indeed, purified IscR bound to the identified yscW-lcrF promoter motif and mRNA levels of lcrF and 24 other T3SS genes were reduced in Y. pseudotuberculosis in the absence of IscR. Importantly, mice orally infected with the Y. pseudotuberculosis ΔiscR mutant displayed decreased bacterial burden in Peyer's patches, mesenteric lymph nodes, spleens, and livers, indicating an essential role for IscR in Y. pseudotuberculosis virulence. This study presents the first characterization of Yersinia IscR and provides evidence that IscR is critical for virulence and type III secretion through direct regulation of the T3SS master regulator, LcrF.

CD38 expression in early B-cell precursors contributes to extracellular signal-regulated kinase-mediated apoptosis.

CD38 is a 45,000 molecular weight transmembrane protein that is expressed in immature and mature lymphocytes. However, the expression and function of CD38 during B-cell differentiation in mice is poorly understood. Here, we report that CD38 is expressed from the earliest stages of B-cell development. Pre-pro-B, pro-B, pre-B and immature B cells from murine bone marrow all stained positive for CD38. Interestingly, CD38 expression increases with B-cell maturation. To assess the role of CD38 during B-cell maturation, CD38-deficient mice were analysed. CD38(-/-) mice showed a significant increase in both the frequency of B-lineage cells and the absolute numbers of pre-pro-B cells in bone marrow; however, no other differences were observed at later stages. CD38 cross-linking in Ba/F3 cells promoted apoptosis and marked extracellular signal-regulated kinase (ERK) phosphorylation, and these effects were reduced by treatment with the mitogen-activated protein kinase/ERK kinase inhibitor PD98059, and similar effects were observed in B-cell precursors from bone marrow. These data demonstrate that B-cell precursors in mouse bone marrow express functional CD38 and implicate the early ligation of CD38 in the ERK-associated regulation of the B-lineage differentiation pathway.

Prevalence of pre-diabetes in young Mexican adults in primary health care.

BACKGROUND: Pre-diabetes in young people is frequently unrecognized or not treated on time, with the consequent loss of opportunity for diabetes prevention. In Mexico, there is scarce information about the prevalence of pre-diabetes in young adults. OBJECTIVE: To determine the prevalence and risk factors for pre-diabetes in young Mexican adults in primary health care. METHODS: In a cross-sectional study, 288 subjects, aged 18-30 years, from a primary care unit were included. Pre-diabetes was diagnosed (according to the criteria of the American Diabetes Association) as impaired fasting glucose (8-12 hours fasting plasma glucose level: 100-125 mg/dl) or impaired glucose tolerance (140-199 mg/dl after a 2-hour oral glucose tolerance test). RESULTS: Prevalence of pre-diabetes was 14.6% [95% confidence interval (CI): 10.7-19.2], whereas that of diabetes was 2.4% (95% CI: 1.0-4.9). A high proportion of patients had history of obesity, diabetes, hypertension and consumption of tobacco and alcohol. Pre-diabetic patients were older than normoglycaemics (pre-diabetic patients: 26±4 years versus normoglycaemic subjects: 24±3 years, P = 0.003) and had higher body mass index (BMI; pre-diabetic patients: 29.4±6.8 kg/m(2) versus normoglycaemic subjects: 26.8±5.8 kg/m(2); P = 0.009), particularly in the case of men (pre-diabetic men: 29.3±7.0 kg/m(2) versus normoglycaemic men: 26.4±5.1 kg/m(2); P = 0.03). Although waist circumference showed a trend to be higher among pre-diabetics, no significant differences were found according to gender (among males: pre-diabetics: 99.5±18.8 cm versus normoglycaemics: 93.3±14.4 cm, P = 0.09; among females: pre-diabetics: 91.5±13.8 cm versus normoglycaemics: 85.8±15.9 cm, P = 0.16). Only age and BMI were significantly associated with the presence of pre-diabetes. CONCLUSIONS: Almost 15% of these young adults had pre-diabetes. Many modifiable and non-modifiable risk factors were present in these patients, but only age and a higher BMI were independent variables significantly associated with pre-diabetes. Timely interventions in primary health care are needed to prevent or delay the progression to diabetes.

Classical to quantum transfer of optical vortices.

We show that an optical vortex beam, implemented classically, can be transferred to the transverse amplitude of a heralded single photon. For this purpose we have relied on the process of spontaneous parametric downconversion (SPDC) for the generation of signal and idler photon pairs, using a pump in the form of a Bessel-Gauss (BG) beam with orbital angular momentum (specifically, with topological charge l = 1 and l = 2). We have designed our source so that it operates within the short SPDC crystal regime for which, the amplitude and phase of the pump may be transferred to a heralded single photon. In order to verify the vortex nature of our heralded single photon, we have shown that the conditional angular spectrum and the transverse intensity at the single-photon level match similar measurements carried out for the pump. In addition, we have shown that when our heralded single photon is diffracted through a triangular aperture, the far-field single-photon transverse intensity exhibits the expected triangular arrangement of intensity lobes associated with the presence of orbital angular momentum.