Unusual presentation of peritonitis with persistent clear aspirate: a case report

<p>Abstract</p> <p>Introduction</p> <p>Peritonitis is the most frequent complication of peritoneal dialysis. Diagnosis of peritonitis includes symptoms and signs of peritonitis with a cloudy aspirate of more than 100 WBC/ml, as well as positive cultures. Although sterile peritonitis has been reported in the literature, to the best of our knowledge this is the first report of an unusual presentation of peritonitis without any white blood cells in the peritoneal aspirate despite multiple positive peritoneal cultures.</p> <p>Case presentation</p> <p>An 82-year-old Caucasian man who had been on continuous cycling peritoneal dialysis for 12 years was admitted to our hospital with general malaise, loss of appetite, weight loss and somnolence. He did not describe abdominal pain or fever. Even though his peritoneal fluid was consistently negative for leukocytes and clear, he had peritonitis with different organisms consecutively.</p> <p>Conclusions</p> <p>Our case report shows that any patient on peritoneal dialysis presenting with evidence of infection (fever, peripheral leukocytosis) without an obvious cause should have aspirate cultures done even if the aspirate is clear and abdominal pain is absent. Our case report may change the initial work-up and management of these patients. We believe this report is of interest to general medicine and emergency room physicians as well as nephrologists.</p

The Genomic Signature of Crop-Wild Introgression in Maize

The evolutionary significance of hybridization and subsequent introgression has long been appreciated, but evaluation of the genome-wide effects of these phenomena has only recently become possible. Crop-wild study systems represent ideal opportunities to examine evolution through hybridization. For example, maize and the conspecific wild teosinte Zea mays ssp. mexicana, (hereafter, mexicana) are known to hybridize in the fields of highland Mexico. Despite widespread evidence of gene flow, maize and mexicana maintain distinct morphologies and have done so in sympatry for thousands of years. Neither the genomic extent nor the evolutionary importance of introgression between these taxa is understood. In this study we assessed patterns of genome-wide introgression based on 39,029 single nucleotide polymorphisms genotyped in 189 individuals from nine sympatric maize-mexicana populations and reference allopatric populations. While portions of the maize and mexicana genomes were particularly resistant to introgression (notably near known cross-incompatibility and domestication loci), we detected widespread evidence for introgression in both directions of gene flow. Through further characterization of these regions and preliminary growth chamber experiments, we found evidence suggestive of the incorporation of adaptive mexicana alleles into maize during its expansion to the highlands of central Mexico. In contrast, very little evidence was found for adaptive introgression from maize to mexicana. The methods we have applied here can be replicated widely, and such analyses have the potential to greatly informing our understanding of evolution through introgressive hybridization. Crop species, due to their exceptional genomic resources and frequent histories of spread into sympatry with relatives, should be particularly influential in these studies

Environmental variables, habitat discontinuity and life history shaping the genetic structure of Pomatoschistus marmoratus

Coastal lagoons are semi-isolated ecosystems exposed to wide fluctuations of environmental conditions and showing habitat fragmentation. These features may play an important role in separating species into different populations, even at small spatial scales. In this study, we evaluate the concordance between mitochondrial (previous published data) and nuclear data analyzing the genetic variability of Pomatoschistus marmoratus in five localities, inside and outside the Mar Menor coastal lagoon (SE Spain) using eight microsatellites. High genetic diversity and similar levels of allele richness were observed across all loci and localities, although significant genic and genotypic differentiation was found between populations inside and outside the lagoon. In contrast to the FST values obtained from previous mitochondrial DNA analyses (control region), the microsatellite data exhibited significant differentiation among samples inside the Mar Menor and between lagoonal and marine samples. This pattern was corroborated using Cavalli-Sforza genetic distances. The habitat fragmentation inside the coastal lagoon and among lagoon and marine localities could be acting as a barrier to gene flow and contributing to the observed genetic structure. Our results from generalized additive models point a significant link between extreme lagoonal environmental conditions (mainly maximum salinity) and P. marmoratus genetic composition. Thereby, these environmental features could be also acting on genetic structure of coastal lagoon populations of P. marmoratus favoring their genetic divergence. The mating strategy of P. marmoratus could be also influencing our results obtained from mitochondrial and nuclear DNA. Therefore, a special consideration must be done in the selection of the DNA markers depending on the reproductive strategy of the species

Regular Strength and Sprint Training Counteracts Bone Aging: A 10-Year Follow-Up in Male Masters Athletes

Cross-sectional and interventional studies suggest that high-intensity strength and impact-type training provide a powerful osteogenic stimulus even in old age. However, longitudinal evidence on the ability of high-intensity training to attenuate age-related bone deterioration is currently lacking. This follow-up study assessed the role of continued strength and sprint training on bone aging in 40- to 85-year-old male sprinters (n = 69) with a long-term training background. Peripheral quantitative computed tomography (pQCT)-derived bone structural, strength, and densitometric parameters of the distal tibia and tibia midshaft were assessed at baseline and 10 years later. The groups of well-trained (actively competing, sprint training including strength training ≥2 times/week; n = 36) and less-trained (<2 times/week, no strength training, switched to endurance training; n = 33) athletes were formed according to self-reports at follow-up. Longitudinal changes in bone traits in the two groups were examined using linear mixed models. Over the 10-year period, group-by-time interactions were found for distal tibia total bone mineral content (BMC), trabecular volumetric bone mineral density (vBMD), and compressive strength index, and for mid-tibia cortical cross-sectional area, medullary area, total BMC, and BMC at the anterior and posterior sites (polar mass distribution analysis) (p < 0.05). These interactions reflected maintained (distal tibia) or improved (mid-tibia) bone properties in the well-trained and decreased bone properties in the less-trained athletes over the 10-year period. Depending on the bone variable, the difference in change in favor of the well-trained group ranged from 2% to 5%. The greatest differences were found in distal tibia trabecular vBMD and mid-tibia posterior BMC, which remained significant (p < 0.05) after adjustment for multiple testing. In conclusion, our longitudinal findings indicate that continued strength and sprint training is associated with maintained or even improved tibial properties in middle-aged and older male sprint athletes, suggesting that regular, intensive exercise counteracts bone aging. © 2021 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research

The genomes of two key bumblebee species with primitive eusocial organization

Background: The shift from solitary to social behavior is one of the major evolutionary transitions. Primitively eusocial bumblebees are uniquely placed to illuminate the evolution of highly eusocial insect societies. Bumblebees are also invaluable natural and agricultural pollinators, and there is widespread concern over recent population declines in some species. High-quality genomic data will inform key aspects of bumblebee biology, including susceptibility to implicated population viability threats. Results: We report the high quality draft genome sequences of Bombus terrestris and Bombus impatiens, two ecologically dominant bumblebees and widely utilized study species. Comparing these new genomes to those of the highly eusocial honeybee Apis mellifera and other Hymenoptera, we identify deeply conserved similarities, as well as novelties key to the biology of these organisms. Some honeybee genome features thought to underpin advanced eusociality are also present in bumblebees, indicating an earlier evolution in the bee lineage. Xenobiotic detoxification and immune genes are similarly depauperate in bumblebees and honeybees, and multiple categories of genes linked to social organization, including development and behavior, show high conservation. Key differences identified include a bias in bumblebee chemoreception towards gustation from olfaction, and striking differences in microRNAs, potentially responsible for gene regulation underlying social and other traits. Conclusions: These two bumblebee genomes provide a foundation for post-genomic research on these key pollinators and insect societies. Overall, gene repertoires suggest that the route to advanced eusociality in bees was mediated by many small changes in many genes and processes, and not by notable expansion or depauperation

Pharmaceutical services for endemic situations in the Brazilian Amazon: organization of services and prescribing practices for Plasmodium vivax and Plasmodium falciparum non-complicated malaria in high-risk municipalities

<p>Abstract</p> <p>Background</p> <p>In spite of the fact that pharmaceutical services are an essential component of all malaria programmes, quality of these services has been little explored in the literature. This study presents the first results of the application of an evaluation model of pharmaceutical services in high-risk municipalities of the Amazon region, focusing on indicators regarding organization of services and prescribing according to national guidelines.</p> <p>Methods</p> <p>A theoretical framework of pharmaceutical services for non-complicated malaria was built based on the Rapid Evaluation Method (WHO). The framework included organization of services and prescribing, among other activities. The study was carried out in 15 primary health facilities in six high-risk municipalities of the Brazilian Amazon. Malaria individuals ≥ 15 years old were approached and data was collected using specific instruments. Data was checked by independent reviewers and fed to a data bank through double-entry. Descriptive variables were analyzed.</p> <p>Results</p> <p>A copy of the official treatment guideline was found in 80% of the facilities; 67% presented an environment for receiving and prescribing patients. Re-supply of stocks followed a different timeline; no facilities adhered to forecasting methods for stock management. No shortages or expired anti-malarials were observed, but overstock was a common finding. On 86.7% of facilities, the average of good storage practices was 48%. Time between diagnosis and treatment was zero days. Of 601 patients interviewed, 453 were diagnosed for <it>Plasmodium vivax</it>; of these, 99.3% received indications for the first-line scheme. Different therapeutic schemes were given to <it>Plasmodium falciparum </it>patients. Twenty-eight (4.6%) out of 601 were prescribed regimens not listed in the national guideline. Only 5.7% individuals received a prescription or a written instruction of any kind.</p> <p>Conclusions</p> <p>The results show that while diagnostic procedure is well established and functioning in the Brazilian malaria programme, prescribing is still an activity that is actually not performed. The absence of physicians and poor integration between malaria services and primary health services make for the lack of a prescription or written instruction for malaria patients throughout the Brazilian Amazon. This fact may lead to a great number of problems in rational use and in adherence to medication.</p