More Evidence of the Link of Interleukin-6 and Interleukin-10 with Critical COVID-19: A Report in Mexican Patients

Background: According to the World Health Organization, Mexico presents one of the highest mortality rates due to coronavirus disease 2019 (COVID-19). The "cytokine storm" phenomenon has been proposed as a pathological hallmark of severe COVID-19. Objective: To determine the association of serum cytokine levels with COVID-19 severity. Methods: We studied the cytokines IL-2, IL-4, IL-6, IL-10, TNF-α, and the IFN-γ serum levels through flow cytometry in 56 COVID-19 patients (24 critical and 32 non-critical) from Northwest Mexico. Results: We observed a significant increase in the IL-6 and the IL-10 levels in the sera of critical patients. These cytokines were also associated with mechanical ventilation necessity and death, IL-6 showing AUC values above 0.7 for both variables; and correlated with Na+, creatinine, and platelet levels. On the other hand, no association was found between IL-2, IL-4, TNF-α, and IFN-γ with tested variables. Conclusion: Our results corroborate previous observations regarding IL-6 and IL-10 involvement in the severity of COVID-19.     

From the Cover: Plastic debris in the open ocean

There is a rising concern regarding the accumulation of floating plastic debris in the open ocean. However, the magnitude and the fate of this pollution are still open questions. Using data from the Malaspina 2010 circumnavigation, regional surveys, and previously published reports, we show a worldwide distribution of plastic on the surface of the open ocean, mostly accumulating in the convergence zones of each of the five subtropical gyres with comparable density. However, the global load of plastic on the open ocean surface was estimated to be on the order of tens of thousands of tons, far less than expected. Our observations of the size distribution of floating plastic debris point at important size-selective sinks removing millimeter-sized fragments of floating plastic on a large scale. This sink may involve a combination of fast nano-fragmentation of the microplastic into particles of microns or smaller, their transference to the ocean interior by food webs and ballasting processes, and processes yet to be discovered. Resolving the fate of the missing plastic debris is of fundamental importance to determine the nature and significance of the impacts of plastic pollution in the ocean.The current period of human history has been referred as the Plastic Age (1). The light weight and durability of plastic materials make them suitable for a very wide range of products. However, the intense consumption and rapid disposal of plastic products is leading to a visible accumulation of plastic debris (2). Plastic pollution reaches the most remote areas of the planet, including the surface waters of the open ocean. Indeed, high concentrations of floating plastic debris have been reported in central areas of the North Atlantic (3) and Pacific Oceans (4, 5), but oceanic circulation models suggest possible accumulation regions in all five subtropical ocean gyres (6, 7). The models predict that these large-scale vortices act as conveyor belts, collecting the floating plastic debris released from the continents and accumulating it into central convergence zones.Plastic pollution found on the ocean surface is dominated by particles smaller than 1 cm in diameter (8), commonly referred to as microplastics. Exposure of plastic objects on the surface waters to solar radiation results in their photodegradation, embrittlement, and fragmentation by wave action (9). However, plastic fragments are considered to be quite stable and highly durable, potentially lasting hundreds to thousands of years (2). Persistent nano-scale particles may be generated during the weathering of plastic debris, although their abundance has not been quantified in ocean waters (9).As the size of the plastic fragments declines, they can be ingested by a wider range of organisms. Plastic ingestion has been documented from small fish to large mammals (10–12). The most evident effects of plastic ingestion are mechanical [e.g., gastrointestinal obstruction in seabirds (13)], but plastic fragments contain contaminants added during plastic manufacture or acquired from seawater through sorption processes [e.g., hydrophobic chemicals (14, 15)]. Recent studies provide evidence that these contaminants can accumulate in the receiving organisms during digestion (14).Our awareness of the significance of plastic pollution in the ocean is relatively recent, and basic questions remain unresolved. Indeed, the quantity of plastic floating in the ocean and its final destination are still unknown (16). Historical time series of surface plastic concentration in fixed ocean regions show no significant increasing trend since the 1980s, despite an increase in production and disposal (3, 16, 17). These studies suggest that surface waters are not the final destination for buoyant plastic debris in the ocean. Nano-fragmentation, predation, biofouling, or shore deposition have been proposed as possible mechanisms of removal from the surface (3, 9, 16).On the basis of samples collected on a circumnavigation cruise (Malaspina 2010 expedition), on five regional cruises, and available data from recent studies (3–5, 17–19), we aim to provide a first-order approximation of the load of plastic debris in surface waters of the open ocean. We also examine the size distribution of floating plastic debris collected along the circumnavigation to provide insight into the nature of possible losses of floating plastic from the open ocean surface.     

Mandibular mesial root canal morphology using micro‐computed tomography in a Brazilian population

To assess the root canal system morphology of mandibular molars by means of micro‐computed tomography, one hundred and four mandibular first molars were investigated and the following were evaluated: Vertucci's classification, the presence of lateral canals and the number of apical foramina. Mesial root canal surface area and volume were obtained by the CTAn and CTvol software. The type of root canal isthmi was classified applying the Hsu & Kim and Fan criteria. The most frequent root canal configuration was Vertucci type IV (46.2%). Lateral canals were observed in all root canal thirds and the average number of apical foramina was 3.15 ± 1.77. Regarding the presence of isthmus, Types I and II were the most prevalent, according to Hsu & Kim and Fan et al. criteria, respectively. Mesial root canals of mandibular molars showed high morphology variability.     

Sex Work Regulation and Sexually Transmitted Infections in Tijuana,Mexico

While reducing the transmission of sexually transmitted infections is a common argument for regulating sex work, relatively little empirical evidence is available regarding the effectiveness of these policies. We investigate the effects of highly publicized sex work regulations introduced in 2005 in Tijuana, Mexico on the incidence of trichomoniasis. State‐level, annual data for the 1995–2012 period are employed that include the incidence rates of trichomoniasis by age group and predictor variables. We find that the regulations led to a decrease in the incidence rate of trichomoniasis. Specifically, while our estimates are somewhat noisy, the all‐ages incidence rate in the 2005–2012 period is roughly 37% lower than what is predicted by our synthetic control estimates and corresponds to approximately 800 fewer reported cases of trichomoniasis per year. We find that the decreases are especially pronounced for 15–24 and 25–44 age cohorts. Copyright © 2016 John Wiley & Sons, Ltd.     

Sinus grafting with autogenous platelet-rich plasma and bovine hydroxyapatite. A histomorphometric study in minipigs

In this study, bovine hydroxyapatite (HA) alone or in combination with activated platelet-rich plasma (PRP) was examined for its usefulness for single-stage sinus grafting in minipigs. In 12 adult minipigs, Schneider's membrane of 24 sinuses was elevated bilaterally through an extra-oral approach. The material was divided into two groups of 12 sinuses. In one of these groups, the space between Schneider's membrane and the sinus wall was grafted with activated autogenous PRP and HA (PRP side). In the other, HA alone was used for grafting (control side). At the same time two dental implants with a machined surface were inserted into the grafting material through the facial sinus wall. Four animals of each group were sacrificed at 3, 6 and 12 weeks, and undecalcified thin-cut and ground sections (Donath 1988) stained with toluidine blue were prepared. In the facial sinus wall, fewer bone-to-implant contacts were present on the PRP side at 3 and 6 weeks than on the control side. At 12 weeks, the PRP side had caught up with the control side. In grafted bone, contacts on the PRP side were more extensive than on the control side at 3 weeks, had dropped below control side levels at 6 weeks and surpassed these at 12 weeks. This study showed that PRP has a differential effect on osseointegration in grafted bone and local host bone. Combined with HA it was not demonstrably superior to HA alone.     

Functional interaction between mutations in the granulocyte colony-stimulating factor receptor in severe congenital neutropenia

Most severe congenital neutropenia (SCN) cases possess constitutive neutrophil elastase mutations; a smaller cohort has acquired mutations truncating the granulocyte colony-stimulating factor receptor (G-CSF-R). We have described a case with constitutive extracellular G-CSF-R mutation hyporesponsive to ligand. Here we report two independent acquired G-CSF-R truncation mutations and a novel constitutive neutrophil elastase mutation in this patient. Co-expression of a truncated receptor chain restored STAT5 signalling responses of the extracellular G-CSF-R mutant, while constitutively-active STAT5 enhanced its proliferative capacity. These data add to our knowledge of SCN and further highlight the importance of STAT5 in mediating proliferative responses to G-CSF.     

Osteoclast activity around loaded and unloaded implants: a histological study in the beagle dog

The mechanisms of bone loss around dental implants are poorly understood. The osteoclast is the most important bone-resorbing cell. Humoral factors seem able to stimulate the differentiation of osteoclasts from mononuclear phagocytes. Bacterial lipopolysaccharides seem to be directly involved in inflammatory bone loss by stimulation of the survival and fusion of preosteoclasts. Excessive load seems to be able to cause bone loss. The aim of this paper was to evaluate the presence and number of osteoclasts in peri-implant bone in control (unloaded) and test (loaded) implants in order to determine if loading per se could be a contributing factor in peri-implant bone resorption. Forty-eight implants were inserted in the mandibles of 4 beagle dogs. After 3 months, a prosthetic superstructure was inserted on 24 implants, whereas in 24 implants only the healing screws were positioned. Twenty-four implants (12 test and 12 control) were retrieved at 6 months, and 24 implants (12 test and 12 control) were retrieved at 12 months. All implants were osseointegrated. The number of osteoclasts found in the crestal bone in the first 3 mm from the implant surface was evaluated. The mean number of osteoclasts were the following: control implants (6 months), 5.66 +/- 0.81; control implants (12 months), 2.55 +/- 1.05; test implants (6 months), 5.25 +/- 1.55; and test implants (12 months), 2.5 +/- 1.0. No statistically significant differences were observed between the control and test implants. According to our data, loading does not seem to have a relevant importance on the osteoclast activation in peri-implant bone.     

Periodontal disease in HIV-positive individuals: association of periodontal indices with stages of HIV disease

BACKGROUND: Periodontal disease has been previously associated with human immunodeficiency virus (HIV) infection, and HIV infection has been considered a modifier of periodontal disease. The aim of this study was to report the prevalence and severity of periodontal disease in a population of HIV-positive individuals and to investigate the association between clinical periodontal indices and the stage of HIV disease, as expressed by CD4 cell counts. METHODS: Thirty-nine male HIV-positive patients were recruited and a medical history was taken. To evaluate periodontal disease, probing depth (PD), attachment level loss (AL), bleeding index (BI), and modified gingival index (MGI) were recorded. Associations between the above indices and CD4 counts were examined. RESULTS: Immunocompromised patients (with CD4 cell counts < 200 cells/microl) showed significantly lower BI and fewer sites with PD and AL > 4 mm compared to patients with CD4 cell counts > 200 cells/microl. When patients with CD4 counts < 500 cells/microl were considered alone, a correlation was observed between CD4 cell counts and BI (r2 = 0.1617, P = 0.0463), MGI (r2 = 0.2123, P = 0.0204), and number of sites with AL > 4 mm (r2 = 0.1469, P = 0.056). CONCLUSIONS: Severely immunocompromised HIV-positive patients showed less severe gingival inflammation than expected. Patients with CD4 cell counts > 500 cells/microl showed no association between CD4 cell count and periodontal indices.     

Fungal infections associated with HIV infection

Oral candidiasis is perhaps the commonest infection seen in HIV disease. The aim of this workshop was to provide a sketch of the multifarious aspects of the disease from a global perspective. To this end the panellists addressed issues such as the virulence of Candida , emergence of antifungal resistance, management of candidiasis and other exotic, oral mycotic diseases. An all-pervasive theme was the dramatic differences in the management of fungal infections consequential to the availability (or the lack) of anti-HIV drugs in the developed and the developing world. Further, the social stigmata associated with the HIV disease in many developing regions in Africa and Asia appears to modify the therapeutic strategies. Additionally, the lesser-known regional variations in the disease manifestations and therapeutic approaches were stark. Further work is direly needed to address these issues.