Is there seasonal periodicity in the prevalence of Helicobacter pylori?

The objective of the present study was to evaluate seasonal periodicity in the prevalence of Helicobacter pylori. A prospective study was performed on 1076 consecutive patients who were investigated in our hospital over a 3-year span because of epigastric complaints. Our findings indicate a significant accumulation of positive Helicobacter pylori tests in October. Gastric acidity, gender, and age did not influence Helicobacter pylori infection significantly. There was no significant correlation between potential seasonal influence on the diagnosis of ulcer disease and the seasonal fluctuation of Helicobacter pylori infection. The seasonality was confirmed by cosinor analysis for the absolute frequencies of H. pylori infections and also for the number of cases positive for H. pylori per number of presenting patients per month. A seasonal concept of a sensitivity threshold for positive Helicobacter pylori testing is introduced, taking into account such factors as immune system, nutrition, and medication status.     

Is colorectal cancer a more aggressive disease in young patients? A population-based study from the Czech Republic

IntroductionThe incidence of colorectal cancer in young patients is increasing. The goal of this study was to investigate whether clinicopathological features and survival differed between young, middle-aged and elderly patients.MethodsThe Czech National Cancer Registry was searched to identify all cases of colorectal cancer between 1982 and 2014. Three subgroups of patients were created: young patients, defined as being between 18 and 40 years of age, middle-aged patients, defined as being between 41 and 74 years of age, and elderly patients, defined as being over the age of 75 years.ResultsA total of 192,241 patients diagnosed with colorectal cancer between the years 1982 and 2014 were included in the study. Out of these, 3,287 patients (1.7%) were between 18 and 40 years of age, 134,139 patients (69.8%) were between 41 and 74 years of age and 54,815 patients (28.5%) were 75 years of age or older. The young patients had a higher incidence of mucinous adenocarcinoma and signet ring cell carcinoma, more advanced disease and more rectal tumours than elderly patients. Nonetheless, young patients received treatment more frequently and had better cancer-specific survival than the older patients.ConclusionThe better prognosis in young patients is presumably due to their better physiological reserve and lower incidence of comorbidities. Efforts should be made in younger patients to diagnose early and treat aggressively.     

Is bigger always better? A critical appraisal of the use of volumetric analysis in the study of the hippocampus

A well-developed spatial memory is important for many animals, but appears especially important for scatter-hoarding species. Consequently, the scatter-hoarding system provides an excellent paradigm in which to study the integrative aspects of memory use within an ecological and evolutionary framework. One of the main tenets of this paradigm is that selection for enhanced spatial memory for cache locations should specialize the brain areas involved in memory. One such brain area is the hippocampus (Hp). Many studies have examined this adaptive specialization hypothesis, typically relating spatial memory to Hp volume. However, it is unclear how the volume of the Hp is related to its function for spatial memory. Thus, the goal of this article is to evaluate volume as a main measurement of the degree of morphological and physiological adaptation of the Hp as it relates to memory. We will briefly review the evidence for the specialization of memory in food-hoarding animals and discuss the philosophy behind volume as the main currency. We will then examine the problems associated with this approach, attempting to understand the advantages and limitations of using volume and discuss alternatives that might yield more specific hypotheses. Overall, there is strong evidence that the Hp is involved in the specialization of spatial memory in scatter-hoarding animals. However, volume may be only a coarse proxy for more relevant and subtle changes in the structure of the brain underlying changes in behaviour. To better understand the nature of this brain/memory relationship, we suggest focusing on more specific and relevant features of the Hp, such as the number or size of neurons, variation in connectivity depending on dendritic and axonal arborization and the number of synapses. These should generate more specific hypotheses derived from a solid theoretical background and should provide a better understanding of both neural mechanisms of memory and their evolution.     

Influence of lunar phases on suicide: the end of a myth? A population-based study

The hypothesis of lunar influence on suicide remains widespread, despite the fact that little scientific evidence to substantiate it. We conducted a population-based study to assess the influence of the lunar phases on suicides according to age, sex, and chosen method. The study included all suicides in Middle Franconia between 1998 and 2003. From a population-based sample of 3351 events, the files of 3054 suicides (1949 males and 1105 females) were complete for the study variables. Data were categorized by lunar phase, sex, age, and chosen method—“violent” vs. “non-violent” acts. No significant relationship was detected between the full, absent, and moon's interphases and suicide incidence. Nevertheless, there was a weak association between the absent moon and choice of a non-violent suicide method in men aged less than the median of 40.2 yrs. There was no evidence of a relationship between suicide and lunar phase. Some explanations for this phenomenon are discussed.     

Is the prevalence of Taenia taeniaeformis in Microtus arvalis dependent on population density?

Populations of common voles Microtus arvalis were studied as hosts of the tapeworm Taenia taeniaeformis during a 14-yr survey. They were monitored in spring, summer, and autumn in a pastoral ecosystem in eastern France. A total of 7,574 voles were sampled during 2 multiannual population fluctuations. A third fluctuation was sampled during the increase phase only. Overall prevalence was lowest in summer (0.6%), increased by 3 times in autumn (1.5%) and a further 5 times in spring (7.8%). Analysis of prevalence, based on 7,384 voles, by multiple logistic regression revealed that extrinsic factors such as season and intrinsic factors such as host age and host density have a combined effect. In the longer term, host age and host density were positively associated with prevalence in summer. Host density was strongly associated with autumn prevalence. There was no association between the fluctuation phase and prevalence. The study shows that a long timescale (here a multiannual survey) is necessary to demonstrate the positive effect of host density on the prevalence of this indirectly transmitted parasite. The demonstration of this relationship depends on the rodents being intermediate rather than definitive hosts.     

Is urbanization scrambling the genetic structure of human populations? A case study

Recent population expansion and increased migration linked to urbanization are assumed to be eroding the genetic structure of human populations. We investigated change in population structure over three generations by analysing both demographic and mitochondrial DNA (mtDNA) data from a random sample of 2351 men from 22 Iranian populations. Potential changes in genetic diversity (theta) and genetic distance (F(ST)) over the last three generations were analysed by assigning mtDNA sequences to populations based on the individual's place of birth or that of their mother or grandmother. Despite the fact that several areas included cities of over one million inhabitants, we detected no change in genetic diversity, and only a small decrease in population structure, except in the capital city (Tehran), which was characterized by massive immigration, increased theta and a large decrease in F(ST) over time. Our results suggest that recent erosion of human population structure might not be as important as previously thought, except in some large conurbations, and this clearly has important implications for future sampling strategies.     

Is the Natura 2000 network sufficient for conservation of butterfly diversity? A case study in Slovenia

Slovenia has one of the most extensive Natura 2000 networks in Europe with 259 SAC’s covering 31.4% of the country. To determine how well does the current network cover the areas of high butterfly diversity and/or aggregation of the butterfly species of conservation concern, the data from the recent survey for a distribution atlas were used. Altogether 99,423 records of 173 species collated after 1979 were used. The data distribution is slightly biased towards SAC’s, with 44.8% of localities within them, most likely due to sparsely sampled urban areas and intensive farmland areas which are found only outside SAC’s. The diversity and distribution of red listed species was evaluated at a 5 × 5 km grid square level. Additionally the importance of the size of the SAC’s was compared to their butterfly species diversity. In general the high diversity areas also hold the largest aggregation of red listed species with core areas concentrated in SW Slovenia. The SAC’s cover majority of areas with high diversity and the distribution of all but one threatened butterfly species. That species is Colias myrmidone, which is now considered extinct in Slovenia with no records after 1993. The most prominent areas with high conservation value in Slovenia not included in the SAC’s network are the Koro?ka region, Gori?ka Brda region, lower Sava River valley and Slovenske Gorice region. The butterfly diversity in small SAC’s is relatively high with increases in size only gradually increasing the species numbers, thus emphasizing the importance and conservation value of small SAC’s for sustaining high butterfly diversity in Slovenia.     

Cancer survival in the northwestern of São Paulo State,Brazil: A population-based study

BackgroundPopulation-based cancer registry (PBCR) data provide crucial information for evaluating the effectiveness of cancer services and reflect prospects for cure by estimating population-based cancer survival. This study provides long-term trends in survival among patients diagnosed with cancer in the Barretos region (São Paulo State, Brazil).MethodsIn this population-based study, we estimated the one- and five-year age-standardized net survival rates of 13,246 patients diagnosed with 24 different cancer types in Barretos region between 2000 and 2018. The results were presented by sex, time since diagnosis, disease stage, and period of diagnosis.ResultsMarked differences in the one- and five-year age-standardized net survival rates were observed across the cancer sites. Pancreatic cancer had the lowest 5-year net survival (5.5 %, 95 %CI: 2.9–9.4) followed by oesophageal cancer (5.6 %, 95 %CI: 3.0–9.4), while prostate cancer ranked the best (92.1 %, 95 %CI: 87.8–94.9), followed by thyroid cancer (87.4 %, 95 %CI: 69.9–95.1) and female breast cancer (78.3 %, 95 %CI: 74.5–81.6). The survival rates differed substantially according to sex and clinical stage. Comparing the first (2000–2005) and last (2012–2018) periods, cancer survival improved, especially for thyroid, leukemia, and pharyngeal cancers, with differences of 34.4 %, 29.0 %, and 28.7 %, respectively.ConclusionTo our knowledge, this is the first study to evaluate long-term cancer survival in the Barretos region, showing an overall improvement over the last two decades. Survival varied by site, indicating the need for multiple cancer control actions in the future with a lower burden of cancer.     

Is the sheep a suitable model to study the mechanical alterations of disc degeneration in humans? A probabilistic finite element model study

Intervertebral disc degeneration is one major source of low back pain, which because of its complex multifactorial nature renders the treatment challenging and thus necessitates extensive research. Experimental animal models have proven valuable in improving our understanding of degenerative processes and potentially promising therapies. Currently, the sheep is the most frequently used large animal in vivo model in intervertebral disc research. However, despite its undoubted value for investigations of the complex biological and cellular aspects, to date, it is unclear whether the sheep is also suited to study the mechanical aspects of disc degeneration in humans.A parametric finite element (FE) model of the L4–5 spinal motion segment was developed. Using this model, the geometry and the material properties of both the human and the ovine spinal segment as well as different appearances of disc degeneration can be depicted. Under pure and combined loads, it was investigated whether degenerative changes to both the human and the ovine model equivalent caused the same mechanical response.Different patterns of degeneration resulted in large variations in the ranges of motion, intradiscal pressure, ligament and facet loads. In the human, but not in the ovine model, all these results differed significantly between different degrees of degeneration.This FE model study highlighted possible differences in the mechanical response to disc degeneration between human and ovine intervertebral discs and indicates the necessity of further, more detailed, investigations.     

Is beauty in the eye of the beholder?

Theories of beauty were evaluated by requiring subjects to “evolve” a beautiful female face using a Genetic Algorithm. In this procedure, a computer program generated a small population of faces (first generation of phenotypes) from a set of random binary strings (genotypes). Genotypes specified the shapes and soft tissue anthropometrics of facial features. Each of the first generation of faces was rated by a subject (relative fitness measure) for beauty. The fittest genotypes then bred in proportion to their fitness, with crossover and mutation of the binary strings, to produce offspring which were again rated by the subject. This process continued until the most beautiful face, for that subject, was evolved. Forty Caucasian subjects (20 M, 20 F) were required to evolve their idealized beautiful female face using this procedure. The features and soft tissue anthropometrics of their final composites were compared to population norms. Also, the final composites, and different faces generated from the same data base, were rated for beauty by independent judges. The results support the conclusion that the concept of facial beauty is the result of sexual selection, and a beautiful female face has features and proportions indicative on high fertility.     

Is Beauty in the Face of the Beholder?

Opposing forces influence assortative mating so that one seeks a similar mate while at the same time avoiding inbreeding with close relatives. Thus, mate choice may be a balancing of phenotypic similarity and dissimilarity between partners. In the present study, we assessed the role of resemblance to Self’s facial traits in judgments of physical attractiveness. Participants chose the most attractive face image of their romantic partner among several variants, where the faces were morphed so as to include only 22% of another face. Participants distinctly preferred a “Self-based morph” (i.e., their partner’s face with a small amount of Self’s face blended into it) to other morphed images. The Self-based morph was also preferred to the morph of their partner’s face blended with the partner’s same-sex “prototype”, although the latter face was (“objectively”) judged more attractive by other individuals. When ranking morphs differing in level of amalgamation (i.e., 11% vs. 22% vs. 33%) of another face, the 22% was chosen consistently as the preferred morph and, in particular, when Self was blended in the partner’s face. A forced-choice signal-detection paradigm showed that the effect of self-resemblance operated at an unconscious level, since the same participants were unable to detect the presence of their own faces in the above morphs. We concluded that individuals, if given the opportunity, seek to promote “positive assortment” for Self’s phenotype, especially when the level of similarity approaches an optimal point that is similar to Self without causing a conscious acknowledgment of the similarity.     

A seasonal periodicity in relapses of multiple sclerosis? A single-center,population-based,preliminary study conducted in Bologna,Italy

Background  

Temporal, i.e., 24-hour, weekly, and seasonal patterns in the occurrence of acute cardiovascular and cerebrovascular events are well documented; however, little is known about temporal, especially seasonal, variation in multiple sclerosis (MS) and its relapses. This study investigated, by means of a validated chronobiological method, whether severe relapses of MS, ones requiring medical specialty consultation, display seasonal differences, and whether they are linked with seasonal differences in local meteorological variables.     

Do treatment protocols improve end results? A study of survival of patients with multiple myeloma in Finland.

OBJECTIVE--To determine whether patients with multiple myeloma treated in three consecutive clinical trials of chemotherapy of the Finnish Leukaemia Group during 1979-85 had a more favourable prognosis than both patients treated in the trial area before the trials and those treated in the rest of Finland. DESIGN--Comparison of the time trend in survival of patients living in the trial area with that of patients living in the rest of Finland. SETTING--Trial area covered 17 of the 21 main hospital districts in Finland (serving more than two thirds of patients with multiple myeloma). PATIENTS--663 Men and 690 women in the trial area and 318 men and 307 women in the reference area aged under 71 in whom multiple myeloma was diagnosed during 1959-85. In the trial area the disease was diagnosed in 455 men and 493 women in 1959-78 and in 208 men and 197 women in 1979-85; in the reference area it was diagnosed in 234 men and 227 women in 1959-78 and in 84 men and 80 women in 1979-85. MAIN OUTCOME MEASURES--Five year cumulative relative survival rates during 1959-85, annual relative survival rates in the first seven years of follow up during 1979-85, and fitted annual relative survival rates in the first five years of follow up during 1959-85. RESULTS--During the first two years of follow up the annual relative survival rates did not differ between the two areas, but in the next five years of follow up patients in the trial area did better than those in the reference area. For cases diagnosed in 1979-85 the difference in the five year cumulative relative survival rates between patients in the trial area and those in the reference area was 10%, those in the trial area doing better. Generalised proportional hazards regression analysis of the first five years of follow up showed that the patients in the trial area had a survival advantage over those in the reference area. The model with the best fit included year of follow up, time of diagnosis, the joint effect of year of follow up and time of diagnosis, and the joint effect of area and time of diagnosis. CONCLUSION--The patients in the trial area benefited from the clinical trials, which suggests that the use of a treatment protocol improves the end results of treatment. In other words, the results favour a systematic treatment schedule in preference to a schedule determined by the free choice of a clinician.     

Is the cost of herbicide resistance expressed in the breakdown of the relationships between characters? A case study using synthetic-auxin-resistant Arabidopsis thaliana mutants

A mutation endowing herbicide resistance is often found to induce a parallel morphological or fitness penalty. To test whether such 'cost' of resistance to herbicides is expressed through lower resource acquisition, changes in resource allocation, or both, is of ecological significance. Here, we analysed 12 morphological traits in 900 plants covering three herbicide resistance mutations at genes AUX1 , AXR1 and AXR2 in the model species Arabidopsis thaliana . Comparing these 2,4-D herbicide-resistant homozygous (RR) and heterozygous (RS) plants to homozygous susceptible (SS) plants, this analysis estimates the dominance level of the resistance allele on morphology. We also demonstrated that the herbicide resistance cost was primarily expressed as a change in resource acquisition (62.1-94% of the analysed traits). Although AUX1 , AXR1 and AXR2 genes act in the same metabolic pathway of auxin response, each resistance factor was found to have its own unique signature in the way the cost was expressed. Furthermore, no link was observed between the absolute fitness penalty and the respective modifications of resource acquisition and/or resource allocation in the resistant plants. These results and their implications for herbicide resistance spread and establishment are discussed.     

Is proline the quintessential sentinel of plants? A case study of postharvest flower senescence in Dianthus chinensis L.

The present investigation primarily focussed on evaluating the efficacy of exogenous proline on the flower longevity of Dianthus chinensis L. Floral buds were harvested at the paint brush stage (i.e., a day prior to anthesis) and divided into 6 sets, with one set of buds (i.e., control) held in distilled water and rest of the 5 sets were supplemented with various concentrations of proline, viz., 10 mM, 20 mM, 30 mM, 40 mM and 50 mM. The application of proline at 40 mM concentration proved out to be most effective in improving the longevity of the flowers by about 4 days as compared to the control. The ameliorated longevity coincided with enhanced floral diameter, fresh mass, dry mass and water content. The flowers with delayed senescence also maintained higher soluble proteins, sugars and phenols. The results suggest that exogenous proline effectively alleviates oxidative stress in the petal tissue, as evident by a relatively lower maloendialdehyde content, which is manifested in the form of reduced lipid peroxidation (LPO). Reduced LPO was commensurate with increased membrane stability, quantified by membrane stability index. Moreover, the flowers with improved longevity exhibited a decline in lipoxygenase activity and significant augmentation of antioxidant enzymes superoxide dismutase, catalase and ascorbate peroxidase.     

Is neoadjuvant chemotherapy for pT2 bladder cancer associated with a survival benefit in a population-based analysis?

BackgroundPatients with organ confined muscle-invasive bladder cancer (MIBC) who are candidates for radical cystectomy (RC) should receive neoadjuvant chemotherapy (CHT). However, the most contemporary CHT use rates indicate low adherence to these guidelines. We tested contemporary neoadjuvant CHT rates and associated cancer-specific mortality (CSM) and overall mortality (OM) in pT2N0 MIBC patients treated with RC.Materials and methodsWithin the SEER database (2004–2015), we identified patients with pT2N0 MIBC patients who underwent RC. CHT administration rates were evaluated using estimated annual percentage changes (EAPCs) analyses. After inverse probability of treatment weighting (IPTW), Kaplan–Meier (KM) analyses and Cox regression models (CRMs) were used to test the effect of CHT vs no CHT on survival. Landmark analyses tested for immortal time bias.ResultsOf 3978 RC patients, 38.2% of patients received CHT. Between 2004 and 2015, CHT rates increased from 15.9% to 66.2% (EAPC: +14.2%; p < 0.001). IPTW-adjusted KM showed 10-year CSM-free survival rates of 78.9% for CHT vs 76.7% for no CHT patients (p = 0.6). Similarly, IPTW-adjusted KM showed 10-year OM-free survival rates of 54.6% for CHT vs 57.9% for no CHT patients (p = 0.8). In IPTW-adjusted MCRMs, CHT was not significantly associated with lower CSM (HR 0.97, CI 0.82–1.14; p = 0.7) or OM (HR 1.02, CI 0.90–1.16; p = 0.7). Virtually the same CSM and OM rates were recorded after landmark analyses.ConclusionsCHT use in pT2N0 MIBC RC patients sharply increased over the study span. However, neoadjuvant CHT was not associated with better survival in this patient group.     

Is the prevalence and shedding concentrations of E. coli O157 in beef cattle in Scotland seasonal?

The prevalence of Escherichia coli O157 in Scottish beef cattle at abattoir was found to be greater during the cooler months [11.2% (95% CI, 8.4-13.9%)] compared to the warmer months [7.5% (95% CI, 5.4-9.6%)]; the reverse of seasonality of human infections. However, high shedding beef cattle (excreting 10(-4) g(-1)) appear to shed greater concentrations of E. coli O157 in the warmer months which may partly explain increased human infection seasonality at this time.