Asymptomatic Healthy Individuals Research Articles

Fecal Carriage of Escherichia coli from Pediatric Patients with Diarrhea and Asymptomatic Healthy Individuals.

Fecal Carriage of Escherichia coli from Pediatric Patients with Diarrhea and Asymptomatic Healthy Individuals.

Asymptomatic HLA-A*02:01–Restricted Epitopes from Herpes Simplex Virus Glycoprotein B Preferentially Recall Polyfunctional CD8+ T Cells from Seropositive Asymptomatic Individuals and Protect HLA Transgenic Mice against Ocular Herpes

Evidence from C57BL/6 mice suggests that CD8(+) T cells, specific to the immunodominant HSV-1 glycoprotein B (gB) H-2(b)-restricted epitope (gB498-505), protect against ocular herpes infection and disease. However, the possible role of CD8(+) T cells, specific to HLA-restricted gB epitopes, in protective immunity seen in HSV-1-seropositive asymptomatic (ASYMP) healthy individuals (who have never had clinical herpes) remains to be determined. In this study, we used multiple prediction algorithms to identify 10 potential HLA-A*02:01-restricted CD8(+) T cell epitopes from the HSV-1 gB amino acid sequence. Six of these epitopes exhibited high-affinity binding to HLA-A*02:01 molecules. In 10 sequentially studied HLA-A*02:01-positive, HSV-1-seropositive ASYMP individuals, the most frequent, robust, and polyfunctional CD8(+) T cell responses, as assessed by a combination of tetramer, IFN-γ-ELISPOT, CFSE proliferation, CD107a/b cytotoxic degranulation, and multiplex cytokine assays, were directed mainly against epitopes gB342-350 and gB561-569. In contrast, in 10 HLA-A*02:01-positive, HSV-1-seropositive symptomatic (SYMP) individuals (with a history of numerous episodes of recurrent clinical herpes disease) frequent, but less robust, CD8(+) T cell responses were directed mainly against nonoverlapping epitopes (gB183-191 and gB441-449). ASYMP individuals had a significantly higher proportion of HSV-gB-specific CD8(+) T cells expressing CD107a/b degranulation marker and producing effector cytokines IL-2, IFN-γ, and TNF-α than did SYMP individuals. Moreover, immunization of a novel herpes-susceptible HLA-A*02:01 transgenic mouse model with ASYMP epitopes, but not with SYMP epitopes, induced strong CD8(+) T cell-dependent protective immunity against ocular herpes infection and disease. These findings should guide the development of a safe and effective T cell-based herpes vaccine.

White Matter Hyperintensities on 1.5 and 3 Tesla Brain MRI in Healthy Individuals

Background : White matter hyperintensities (WMH) on T2-weighted magnetic resonance imaging (MRI) are frequent incidental findings in brains of asymptomatic healthy individuals (HI). The morphological and spatial distribution of these WMH between standard 1.5T scanners and increasingly available 3T scanners in a large population of HI in clinical routine settings has not been investigated. Objectives: To investigate the effect of changing from a 1.5T to a 3T MRI scanner on the number, volume and spatial distribution of WMH on brain MRI in a population of clinically HI. Materials and Methods: Fifty-three (53) HI were examined using T2 weighted sequences on both 1.5T and 3T within one week in a random order. The WMH were outlined semi-automatically by two blinded operators. Number and volume of WMH were calculated. Spatial lesion distribution was assessed using WMH probability maps (WMHPM). Paired-wise analysis examined the proportion of WMH not found on 1.5T and/or 3T. A posteriori unblinded analysis was conducted to examine the non-overlapping identifications of WMH between the 1.5T and 3T. Results : For paired-wise WMH analysis, 3T showed significantly higher WMH number and individual volume compared to 1.5 T ( p <0.001). Logistic regression analysis showed that likelihood of missing WMH on 1.5T was significantly higher for smaller WMH. WMHPM revealed spatial WMH differences on 3T compared to 1.5T, with WMH more pronounced in the occipital regions with higher field strength. Conclusion: This study showed that use of higher magnetic field strength identified more WMH in healthy subjects with respect to both morphological and spatial characteristics. These WMH do not necessarily represent pathology; however, these findings should be taken into account in lesion segmentation on a 3T MRI and might suggest the use of universally accepted guidelines for lesions’ segmentation on higher magnetic field, especially when it is executed by different operators and/or centers.

Decreased Basal and Postprandial Plasma Serotonin Levels in Patients With Functional Dyspepsia

Patients with diarrhea-predominant irritable bowel syndrome (IBS) have been found to have increased postprandial levels of serotonin (5-HT). Functional dyspepsia (FD) and IBS have been proposed to have common methods of pathogenesis, but little is known about the role of 5-HT in FD. We measured postprandial levels of 5-HT in 54 patients with FD (based on Rome III criteria) and 28 asymptomatic healthy individuals (controls). Patients with gastroesophageal reflux disease and IBS as their predominant symptom were excluded. After an overnight fast, the subjects drank a liquid meal (Ensure; 1.06 kcal/mL at 30 mL/min) and underwent a (13)C-octanoic acid breath test to measure gastric emptying times. Blood samples were collected at 0, 30, 60, 90, and 120 minutes after the liquid meal for the 5-HT assay. Thirty-five patients with FD (65%) had postprandial distress syndrome, and 6 (11%) had a combination of postprandial distress syndrome and epigastric pain syndrome. There were no differences in rates of gastric emptying between patients with FD (103.6 ± 19.4 minutes) and controls (83.1 ± 4.0 minutes; P = .30). However, patients with FD had lower caloric intake (823.40 ± 44.1 kcal) than controls (1021 ± 68.2 kcal; P = .026). Patients with FD also had lower basal (P = .03) and postprandial plasma levels of serotonin at 30 minutes (P = .04), 60 minutes (P = .01), 90 minutes (P = .02), and 120 minutes (P = .002) than controls, as well as area under the curve values over the 120-minute time period (P = .005). Repeated-measures analysis of variance correlated 5-HT level with FD (P < .001). In contrast to patients with diarrhea-predominant IBS, those with FD have decreased basal and postprandial plasma levels of 5-HT. These findings indicate that the pathogenic mechanism of FD differs from that of diarrhea-predominant IBS, and that strategies to alter 5-HT levels or activity might be developed to treat patients with FD.

Helicobacter pylori infection

Helicobacter pylori infection is one of the most common chronic bacterial infections among humans worldwide. However, there is no information on the epidemiology of H. pylori infection in Al Madinah, Saudi Arabia. This study was conducted to determine the seroprevalence of H. pylori in asymptomatic healthy individuals and the possible relationship between H. pylori infection and sociodemographic, lifestyle, and environmental factors in this region. A hospital-based cross-sectional study was conducted on a consecutive sample of asymptomatic healthy individuals. A pilot-tested interview format was used as the research tool. Venous blood was collected from individuals and sera were separated. The enzyme-linked immunosorbent assay was used to determine H. pylori IgG antibody levels in all serum samples. A total of 456 samples were collected. H. pylori antibodies were found in 129 (28.3%) individuals. Seroprevalence of 16.9% was found in individuals younger than 20 years of age, which gradually increased with age and reached 36.8% by the age of 50. After controlling for the confounding factors, significant independent predictors of seropositive state were: rural residence [odds ratio (OR)=2.5, 95% confidence interval (CI)=1.3, 4.7], crowded housing (OR=1.6, 95% CI=1.1, 2.6), low socioeconomic status (OR=3.3, 95% CI=1.6, 8.8), using tanks for drinking water supply (OR=2.2, 95% CI=1.2, 7.4), active smoking (OR=5.6, 95% CI=3.2, 9.8), alcohol drinking (OR=2.3, 95% CI=1.5, 6.2), eating raw vegetables (OR=3.2, 95% CI=1.4, 7.1), eating spicy food (OR=2.1, 95% CI=1.3, 3.5), and presence of asthmatic/atopic symptoms (OR=2.5, 95% CI=1.3, 5.9). No associations were found between infection and age, gender, source of sewage disposal, eating fruits, or family history of upper gastrointestinal symptoms. Infection with H. pylori is declining among healthy individuals of Al Madinah, Saudi Arabia. Infection is acquired at an early age and reaches up to 36.9% as age advances. The risk of H. pylori seropositivity was related to socioeconomic, lifestyle, and environmental factors. A nationwide epidemiological study is warranted to determine the seroprevalence of H. pylori in Saudi Arabia.

Morphological Variations of Hippocampal Formation in Epilepsy

Researchers at Hospital Sao Paulo and other centers in Brazil compared the hippocampal formation (HF) morphology of healthy asymptomatic individuals (n=30) with that of patients with mesial temporal lobe epilepsy and hippocampal sclerosis (MTLE-HS)(n=68), of patients with malformations of cortical development (MCD)(n=34), and of patients with morphological HF variations without other structural signs (pure MVHF)(n=12).

A systematic evaluation of methods to optimize culture-based recovery of Clostridium difficile from stool specimens

With the increasing prevalence of Clostridium difficile infection among hospitalized patients, a clear understanding of C. difficile epidemiology is needed to evaluate current prevention policies, and to create new and effective policies. To determine the epidemiology of C. difficile, the most sensitive methods for detection of C. difficile are required. The purpose of this study was to systematically assess multiple methods to determine the most sensitive method to recover C. difficile from stool and rectal swabs. Stool samples from healthy asymptomatic individuals that were collected and confirmed to be culture negative for C. difficile were spiked with known concentrations of C. difficile ranging from 104 CFU of C. difficile per ml of stool to 10 CFU per ml. Two sets of experiments (A and B) were performed and each involved multiple combinations of untreated and treated stool/rectal swab specimens and selective and non-selective broth and agar. Overall, recovery of C. difficile was increased with the use of an initial broth enrichment followed by plating to solid medium. The most sensitive method of C. difficile detection for both stools and swab specimens was heat shock prior to inoculation of cycloserine-cefoxitin mannitol broth with taurocholate lysozyme cysteine (CCMB, Anaerobe Systems, Morgan Hill, CA) followed by isolation from pre-reduced TSA II with 5% sheep blood (BAP, BBL BD and Co., Sparks, MD). Identifying the most sensitive method of recovery will allow for further study of asymptomatic C. difficile carriers and their role in the epidemiology of C. difficile.

Hyperuricaemia elevates circulating CCL2 levels and primes monocyte trafficking in subjects with inter-critical gout

To investigate the effect of hyperuricaemia on serum chemokine (C-C motif) ligand 2 (CCL2) levels and blood monocytes in people with gout. Whole blood was collected from subjects with a history of acute or chronic gout but not currently experiencing an attack of gout, subjects with asymptomatic hyperuricaemia and healthy individuals with normouricaemia. Serum concentrations of CCL2 were measured by bead array and levels of CD14(+)/CD11b(+) blood monocytes determined by flow cytometry. Subjects with gout and asymptomatic hyperuricaemia had higher serum levels of CCL2 and showed an increase in the percentage of circulating CD14(+) monocytes compared with subjects with normouricaemia. Hyperuricaemia causes elevated serum CCL2 levels and increased monocyte recruitment that may be driven by soluble uric acid-induced CCL2 production. Hyperuricaemia may initiate subclinical priming of circulating blood monocytes for adhesion and trafficking during a gout attack.

Foot Type Biomechanics Part 2: Are structure and anthropometrics related to function?

BackgroundMany foot pathologies are associated with specific foot types. If foot structure and function are related, measurement of either could assist with differential diagnosis of pedal pathologies. HypothesisBiomechanical measures of foot structure and function are related in asymptomatic healthy individuals. MethodsSixty-one healthy subjects’ left feet were stratified into cavus (n=12), rectus (n=27) and planus (n=22) foot types. Foot structure was assessed by malleolar valgus index, arch height index, and arch height flexibility. Anthropometrics (height and weight), age, and walking speed were measured. Foot function was assessed by center of pressure excursion index, peak plantar pressure, maximum force, and gait pattern parameters. Foot structure and anthropometric variables were entered into stepwise linear regression models to identify predictors of function. ResultsMeasures of foot structure and anthropometrics explained 10–37% of the model variance (adjusted R2) for gait pattern parameters. When walking speed was included, the adjusted R2 increased to 45–77% but foot structure was no longer a factor. Foot structure and anthropometrics predicted 7–47% of the model variance for plantar pressure and 16–64% for maximum force parameters. All multivariate models were significant (p<0.05), supporting acceptance of the hypothesis. Discussion and conclusionFoot structure and function are related in asymptomatic healthy individuals. The structural parameters employed are basic measurements that do not require ionizing radiation and could be used in a clinical setting. Further research is needed to identify additional predictive parameters (plantar soft tissue characteristics, skeletal alignment, and neuromuscular control) and to include individuals with pathology.

Errol Mendus Edwards

<h3>Background:</h3> Tennis elbow (TE) is a painful condition affecting the common extensor origin at the lateral humeral epicondyle. Colour Doppler examination has shown increased blood flow at this site and...

The study of hepatitis B surface antigen and anti-HCV in HIV infected patients

Methods The study group included 106 HIV positive patients with history of heterosexual contact and the control group included 30 asymptomatic healthy individuals. The sera of patients were tested for HBsAg and antiHCV using third generation ELISA kits. The samples positive for first kit were retested for confirmation of results. The sera of control group were simultaneously screened for HIV, HBsAg, and anti-HCV by ELISA method.

Minimum repetitions for stable measures of visual dependency using the dot version of the computer-based Rod-Frame test

Visual dependency is a condition where spatial orientation is mainly dependent on visual information. It can be affected in conditions such as vestibular disorders, brain injuries and neck pain including whiplash. Visual dependency can be assessed with a computer-based, dot version, Rod-Frame test (C-RFTdot) by measuring the deviation of a rod (comprised of two dots) from the true vertical within tilted frames at 18° in both clockwise and anticlockwise directions. However, the number of test repetitions differs between studies. The purpose of this study was to investigate the minimum number of repetitions to obtain stable C-RFTdot outcomes. Thirty-one asymptomatic subjects were recruited. With a frame tilt of 18° (clockwise and anticlockwise), the rod was pre-set at 20° in both clockwise and anticlockwise directions. The rod could be rotated, using a mouse, to a minimum of 0.01°. The clockwise and anticlockwise deviations from the true vertical were positive values and negative values, respectively. A session consisted of two measures of deviations of pre-set rod conditions in each frame. Their signed values were averaged for analysis. Eight sessions were conducted. The differences between the mean values of N−1 and N repetitions (2 ≦ N ≦ 8) were measured. Differences were similar across repetitions and the standard deviations tended to decline over repetitions. Intraclass correlation coefficients (ICC) for five and more repetitions became >0.8 in each frame condition. Hence, five was considered the minimum number of testing so that the C-RFTdot can give consistent measures of deviation from the vertical in asymptomatic healthy individuals.

Immunodominant “Asymptomatic” Herpes Simplex Virus 1 and 2 Protein Antigens Identified by Probing Whole-ORFome Microarrays with Serum Antibodies from Seropositive Asymptomatic versus Symptomatic Individuals

Herpes simplex virus 1 (HSV-1) and HSV-2 are medically significant pathogens. The development of an effective HSV vaccine remains a global public health priority. HSV-1 and HSV-2 immunodominant "asymptomatic" antigens (ID-A-Ags), which are strongly recognized by B and T cells from seropositive healthy asymptomatic individuals, may be critical to be included in an effective immunotherapeutic HSV vaccine. In contrast, immunodominant "symptomatic" antigens (ID-S-Ags) may exacerbate herpetic disease and therefore must be excluded from any HSV vaccine. In the present study, proteome microarrays of 88 HSV-1 and 84 HSV-2 open reading frames(ORFs) (ORFomes) were constructed and probed with sera from 32 HSV-1-, 6 HSV-2-, and 5 HSV-1/HSV-2-seropositive individuals and 47 seronegative healthy individuals (negative controls). The proteins detected in both HSV-1 and HSV-2 proteome microarrays were further classified according to their recognition by sera from HSV-seropositive clinically defined symptomatic (n = 10) and asymptomatic (n = 10) individuals. We found that (i) serum antibodies recognized an average of 6 ORFs per seropositive individual; (ii) the antibody responses to HSV antigens were diverse among HSV-1- and HSV-2-seropositive individuals; (iii) panels of 21 and 30 immunodominant antigens (ID-Ags) were identified from the HSV-1 and HSV-2 ORFomes, respectively, as being highly and frequently recognized by serum antibodies from seropositive individuals; and (iv) interestingly, four HSV-1 and HSV-2 cross-reactive asymptomatic ID-A-Ags, US4, US11, UL30, and UL42, were strongly and frequently recognized by sera from 10 of 10 asymptomatic patients but not by sera from 10 of 10 symptomatic patients (P < 0.001). In contrast, sera from symptomatic patients preferentially recognized the US10 ID-S-Ag (P < 0.001). We have identified previously unreported immunodominant HSV antigens, among which were 4 ID-A-Ags and 1 ID-S-Ag. These newly identified ID-A-Ags could lead to the development of an efficient "asymptomatic" vaccine against ocular, orofacial, and genital herpes.

Correlation of HLA B27 subtypes with clinical features of ankylosing spondylitis

The aim of the present study was to identify the B*27 subtypes associated with ankylosing spondylitis (AS) in our population and correlate them with clinical features of AS. Whole blood samples were collected from 81 HLA-B27 positive AS patients and 29 controls (asymptomatic healthy unrelated individuals) positive for HLA-B27. Clinical details of the patients were recorded which included history of inflammatory back pain, sacroiliitis, spine involvement, enthesitis, peripheral arthritis and uveitis. HLA-B27 subtypes were detected using commercially available techniques. Fisher's exact test was used for statistical analysis. The subtypes observed in AS patients were B*2705 (67.9%, 55/81), B*2704 (28.4%, 23/81), B*2707 (2/81) and B*2702 (1/81). Subtypes in the controls were B*2705 (62.07%, 18/29), B*2707 (27.59%, 8/29) and B*2704 (10.34%, 3/29). Uveitis was observed more in B*2704-positive AS patients (34.78%, 8/23) compared to B*2705-positive AS patients (16.36%, 9/55). However, the difference was not statistically significant (P = 0.130). No major differences were found between B*2705 and B*2704 for other clinical features. B*2705 was the main subtype observed in both patient and control groups. Frequency of B*2704 was more in AS patients compared to controls. Occurrence of AS-associated uveitis was more often in B*2704-positive AS patients compared to B*2705-positive ones.

Role of vitamin D levels and vitamin D receptor polymorphisms in relation to coronary artery disease

Assessment of association between plasma vitamin D levels, vitamin D receptor (VDR) gene polymorphisms, and coronary artery disease (CAD) in a predisposed Asian Indian cohort. Patients with angiographically proven CAD having age at onset less than 60 years for men and less than 65 years for women were recruited in the Indian Atherosclerosis Research Study and treated as cases (N=287), whereas asymptomatic healthy matched individuals were enrolled from the population, who showed normal electrocardiogram and acted as controls (N=241). Plasma [vitamin D (25-hydroxy vitamin D)] levels were measured by enzyme-linked immunosorbent assay, and five haplotype-tagging single nucleotide polymorphisms were genotyped by ABI Taqman assays. Mean vitamin D levels were significantly lower in patients with CAD (10.59 ng/ml) than in controls (11.82 ng/ml) (P=0.036). Vitamin D showed protective association against CAD (odds ratio: 0.54, 95% confidence interval: 0.34-0.84, P=0.007) after adjusting for conventional risk factors. Patients in the first vitamin D quartile showed 2.54 times greater risk for CAD than those in the fourth quartile. There was no significant association of VDR single nucleotide polymorphisms/haplotypes with either vitamin D or CAD. Vitamin D levels were significantly lower in vegetarians than in nonvegetarians (P=0.048) and showed inverse association with body weight (P=0.054), triglyceride (P=0.031), and body mass index (P=0.020). Low vitamin D level was associated with an enhanced risk for incident CAD. VDR genotypes did not show any association with either vitamin D levels or CAD.

The PTPN22 allele encoding an R620W variant interferes with the removal of developing autoreactive B cells in humans

Protein tyrosine phosphatase nonreceptor type 22 (PTPN22) gene polymorphisms are associated with many autoimmune diseases. The major risk allele encodes an R620W amino acid change that alters B cell receptor (BCR) signaling involved in the regulation of central B cell tolerance. To assess whether this PTPN22 risk allele affects the removal of developing autoreactive B cells, we tested by ELISA the reactivity of recombinant antibodies isolated from single B cells from asymptomatic healthy individuals carrying one or two PTPN22 risk allele(s) encoding the PTPN22 R620W variant. We found that new emigrant/transitional and mature naive B cells from carriers of this PTPN22 risk allele contained high frequencies of autoreactive clones compared with those from non-carriers, revealing defective central and peripheral B cell tolerance checkpoints. Hence, a single PTPN22 risk allele has a dominant effect on altering autoreactive B cell counterselection before any onset of autoimmunity. In addition, gene array experiments analyzing mature naive B cells displaying PTPN22 risk allele(s) revealed that the association strength of PTPN22 for autoimmunity may be due not only to the impaired removal of autoreactive B cells but also to the upregulation of genes such as CD40, TRAF1, and IRF5, which encode proteins that promote B cell activation and have been identified as susceptibility genes associated with autoimmune diseases. These data demonstrate that early B cell tolerance defects in autoimmunity can result from specific polymorphisms and precede the onset of disease.

Immune response in symptomatic and asymptomatic neurocysticercosis

Innate immune system is crucial in the pathogenesis of neurocysticercosis (NCC) and helminth glycans can induce anti-inflammatory milieu via toll-like receptor 4 (TLR4) dependent mechanisms. The association of TLR4 and cytokines is yet to be explored in NCC. Therefore, the present study detected the serum levels of cytokines and soluble intercellular adhesion molecule (sICAM)-1 in asymptomatic and symptomatic NCC and their association with TLR4 expression. Sixty eight patients with NCC (asymptomatic, 36 and symptomatic, 32), and age and gender matched 37 healthy controls were enrolled to determine the levels of different pro- and anti-inflammatory cytokines, sICAM-1 in the serum by ELISA and expression of TLR4 in peripheral blood mononuclear cells (PBMCs) by flow cytometry. In asymptomatic NCC cases, the levels of IL-10 and IL-4 were significantly elevated compared to healthy controls and symptomatic NCC patients whereas the levels of IFN-γ, TNF-α, IL-17, IL-23 and sICAM-1 were higher in symptomatic NCC patients compared to healthy controls and asymptomatic NCC individuals. Frequency of TLR4 expressing PBMCs and CD14 positive cells were significantly higher in both groups of NCC. Although the number of TLR4 expressing cells was almost similar in both asymptomatic and symptomatic groups, the median fluorescence intensity was significantly higher in symptomatic group indicating that higher levels of TLR4 expression in symptomatic patients correlated with enhanced pro-inflammatory cytokine production.

Right ventricular mechanical dispersion is related to malignant arrhythmias: a study of patients with arrhythmogenic right ventricular cardiomyopathy and subclinical right ventricular dysfunction

We evaluated if right ventricular (RV) mechanical dispersion by strain was related to ventricular arrhythmias (VT/VF) in patients with arrhythmogenic right ventricular cardiomyopathy (ARVC) and if mechanical dispersion was increased in so far asymptomatic mutation carriers. We included 69 patients, 42 had symptomatic ARVC and 27 were mutation positive asymptomatic family members. Forty healthy individuals served as controls. Myocardial strain was assessed in 6 RV and 16 left ventricular (LV) segments. Contraction duration (CD) in 6 RV and 16 LV segments were measured as the time from onset R on electrocardiogram to maximum myocardial shortening in each segment. The standard deviation of CD was defined as mechanical dispersion. Mechanical dispersion was more pronounced in ARVC patients with arrhythmias compared with asymptomatic mutation carriers and healthy individuals in RV [52(41,63) vs. 35(23,47) vs. 13(9,19)ms, P < 0.001]. Mechanical dispersion was more pronounced in asymptomatic mutation carriers compared with healthy individuals (P < 0.001). Right ventricular mechanical dispersion predicted VT/VF in a multivariate logistic regression analysis [odds ratio (OR), 1.66 (95% confidence interval (CI) 1.06-2.58), P < 0.03]. Right ventricular and LV function by strain were reduced in symptomatic ARVC patients and correlated significantly (R = 0.81, P < 0.001). Right ventricular and LV strain were reduced in asymptomatic mutation carriers compared with healthy individuals (P < 0.001). Right ventricular mechanical dispersion was pronounced in patients with ARVC with VT/VF. Right ventricular mechanical dispersion was present in asymptomatic mutation carriers and may be helpful in risk stratification. Right ventricular and LV function correlated in ARVC patients implying that ARVC is a biventricular disease.

Effect of age on the biomechanical and microcirculatory properties of the skin in healthy individuals and during venous ulceration.

Background:With aging there is alteration of elastic properties of the skin and skin-blood flow.Aim:The purpose of this study was to compare age-related changes in selected biomechanical parameters of the skin (skin hardness, skin extensibility, relaxation time constant, τ) and subcutaneous microcirculatory quality (SMQ) in individuals with and without venous diseases.Materials and Methods:Two groups were studied: the first group was of asymptomatic healthy individuals and the second group included patients with chronic venous insufficiency (CVI) and venous ulceration, without edema. Both groups were subdivided to three age categories (21-40, 41-60 and 61-90 years old). Skin hardness was measured by durometer, extensibility and τ were measured using extensometer and SQM was assessed via postural vasoconstrictive response (LDF).Results:Results showed that skin hardness, extensibility, and τ-values were increased, whereas LDF was decreased in the older groups as compared with younger groups. These changes are attributed to alterations in the skin structure and reduced capillaries density networks. Similar behavior was found in the biomechanical and microcirculatory changes in patients with venous ulceration and CVI, but these changes were more increased further in older patients with venous ulceration as compared with older patients with CVI and that can be attribute to more intense response against tissue injury.Conclusions:Since aging elevated skin hardness and extensibility, but lowered vasoconstrictive response in individuals, with and without, venous diseases, we conclude that aging process is likely to cause an accumulation of damaged skin tissues and that could induce an apparent antigen-driven response that altered skin structure and the subsequent biomechanical properties obtained in this study.

Sequence Analysis of East Asian cagA of Helicobacter pylori Isolated from Asymptomatic Healthy Japanese and Thai Individuals

CagA, especially East Asian type, is one of the most important virulence factors of Helicobacter pylori, which is believed to contribute to the gastric cancer development. There is extreme sequence heterogeneity on 3' region of cagA gene, demonstrated by the sequence analysis of cagA of H. pylori strains isolated from gastric disease patients. However, whether such heterogeneity of the cagA gene sequence is related to the pathogenicity of H. pylori in the gastric cancer development is not certain. Therefore, in this study, the 3' region of cagA sequences isolated from asymptomatic healthy individuals in Japan and Thailand, which show high and low gastric cancer prevalence, respectively, were analyzed and compared with those from patients with gastric cancer. The CagA sequences analysis in 21 and 12 H. pylori DNA samples obtained from Japanese and Thai individuals, respectively, by the molecular phylogenetic method showed that the sequences were more conserved in the Thai individuals (concordance rates among Thai sequences, 93.9-100%) than in the Japanese individuals (concordance rates among Japanese sequences, 82.8-100%) as shown by unrooted neighbor-joining (N-J) consensus trees constructed with the sequence between Asn869 and Ala967 in CagA. CagA sequences in gastric cancer patients were obtained from published data; analysis of these sequences revealed that CagA sequences from almost all Thai individuals were concentrated in one branch. In contrast, CagA sequences from Japanese individuals were uniformly distributed throughout the N-J consensus tree. These results suggest that the difference in the CagA sequences between asymptomatic healthy Japanese and Thai individuals may be linked to the incidence of gastric cancer in Japan and Thailand.