Human NK cells adapt their immune response towards increasing multiplicities of infection of <Emphasis Type="Italic">Aspergillus fumigatus</Emphasis>

Background

The saprophytic fungus Aspergillus fumigatus reproduces by generation of conidia, which are spread by airflow throughout nature. Since humans are inhaling certain amounts of spores every day, the (innate) immune system is constantly challenged. Even though macrophages and neutrophils carry the main burden, also NK cells are regarded to contribute to the antifungal immune response. While NK cells reveal a low frequency, expression and release of immunomodulatory molecules seem to be a natural way of their involvement.

Results

In this study we show, that NK cells secrete chemokines such as CCL3/MIP-1α, CCL4/MIP-1β and CCL5/RANTES early on after stimulation with Aspergillus fumigatus and, in addition, adjust the concentration of chemokines released to the multiplicity of infection of Aspergillus fumigatus.

Conclusions

These results further corroborate the relevance of NK cells within the antifungal immune response, which is regarded to be more and more important in the development and outcome of invasive aspergillosis in immunocompromised patients after hematopoietic stem cell transplantation. Additionally, the correlation between the multiplicity of infection and the expression and release of chemokines shown here may be useful in further studies for the quantification and/or surveillance of the NK cell involvement in antifungal immune responses.

     

Defining electronic-prescribing and infusion-related medication errors in paediatric intensive care – a Delphi study

Background

The use of health information technology (HIT) to improve patient safety is widely advocated by governmental and safety agencies. Electronic-prescribing and smart-pump technology are examples of HIT medication error reduction strategies. The introduction of new errors on HIT implementation is, however, also recognised. To determine the impact of HIT interventions, clear medication error definitions are required. This study aims to achieve consensus on defining as medication errors a range of either technology-generated, or previously unaddressed infusion-related scenarios, common in the paediatric intensive care setting.

Methods

This study was conducted in a 23-bed paediatric intensive care unit (PICU) of an Irish tertiary paediatric hospital. A modified Delphi technique was employed: previously undefined medication-incidents were identified by retrospective review of voluntary incident reports and clinical pharmacist interventions; a multidisciplinary expert panel scored each incident using a 9-point Likert scale over a number of iterative rounds; levels of agreement were assessed to produce a list of medication errors. Differences in scoring between healthcare professionals were assessed.

Results

Seventeen potential errors or ‘scenarios’ requiring consensus were identified, 13 of which related to technology recently implemented into the PICU. These were presented to a panel of 37 participants, comprising of doctors, nurses and pharmacists. Consensus was reached to define as errors all reported smart-pump scenarios (n =?6) and those pertaining to the pre-electronic process of prescribing weight-based paediatric infusions (n =?4). Of 7 electronic-prescribing scenarios, 4 were defined as errors, 2 were deemed not to be and consensus could not be achieved for the last. Some differences in scoring between healthcare professionals were found, but were only significant (p <?0.05) for two and three scenarios in consensus rounds 1 and 2 respectively.

Conclusion

The list of medication errors produced using the Delphi technique highlights the diversity of previously undefined medication errors in PICU. The increased complexity of electronic-prescribing processes is evident from the difficulty in achieving consensus on those scenarios. Reducing ambiguity in defining medication errors should assist future research on the impact of HIT medication safety initiatives in critical care. The increasing use of HIT and associated new errors will necessitate further similar studies.

     

Effects of streptozotocin-induced diabetes on leg muscle contractile properties and motor neuron morphology in rats

Skeletal muscle fiber subtypes are differentially sensitive to diabetes-related pathology; For example, fast-twitch muscles exhibit severe decreases in contraction force while slow-twitch muscles demonstrate prolonged half-relaxation time. However, such alterations have only been examined after a relatively short period following diabetes onset, with no information available regarding muscle damage caused by longer disease periods (>20 weeks). This study examined alterations in the contractile properties of the medial gastrocnemius (fast-twitch) and soleus (slow-twitch) muscles, as well as morphological changes in their motor neurons 12 and 22 weeks after diabetes onset. Adult male Wistar rats were divided into diabetic (12- or 22-week post-streptozotocin injection) and age-matched control groups. Electrically evoked maximum twitch and tetanic tension were recorded from leg muscles. Additionally, motor neuron number and cell body size were examined. At 12 weeks after diabetes onset, decreases in twitch force were observed predominantly in medial gastrocnemius muscles, while soleus muscles exhibited prolonged half-relaxation time. However, these differences became ambiguous at 22 weeks, with decreased twitch force and prolonged half-relaxation time observed in both muscles. On the other hand, reduction in soleus motor neurons was observed 12 weeks after diabetes onset, while medial gastrocnemius motor neurons were diminished at 22 weeks. These data indicate that experimental diabetes induces differential damage to medial gastrocnemius and soleus muscles as well as motor neurons. These diabetes-induced differences may partly underlie the differential deficits observed in gastrocnemius and soleus.     

Dysfunction of Mesenchymal Stem Cells Isolated from Metabolic Syndrome and Type 2 Diabetic Patients as Result of Oxidative Stress and Autophagy may Limit Their Potential Therapeutic Use

Mesenchymal stem cells (MSC) have become a promising tool for therapeutic intervention. Their unique features, including self-renewal, multipotency and immunomodulatory properties draw the worldwide attention of researchers and physicians with respect to their application in disease treatment. However, the environment (so-called niche) from which MSCs are isolated may determine their usefulness. Many studies indicated the involvement of MSCs in ageing and disease. In this review, we have focused on how type 2 diabetes (T2D) and metabolic syndrome (MS) affect MSC properties, and thus limit their therapeutic potential. Herein, we mainly focus on apoptosis, autophagy and mitochondria deterioration processes that indirectly affect MSC fate. Based on the data presented, special attention should be paid when considering autologous MSC therapy in T2D or MS treatments, as their therapeutic potential may be restricted.     

Sex Differences in HIV Infection

Purpose of Review

This review will outline the multilevel effects of biological sex on HIV acquisition, pathogenesis, treatment response, and prospects for cure. Potential mechanisms will be discussed along with future research directions.

Recent Findings

HIV acquisition risk is modified by sex hormones and the vaginal microbiome, with the latter acting through both inflammation and local metabolism of pre-exposure prophylaxis drugs. Female sex associates with enhanced risk for non-AIDS morbidities including cardiovascular and cerebrovascular disease, suggesting different inflammatory profiles in men and women. Data from research on HIV cure points to sex differences in viral reservoir dynamics and a direct role for sex hormones in latency maintenance.

Summary

Biological sex remains an important variable in determining the risk of HIV infection and subsequent viral pathogenesis, and emerging data suggest sex differences relevant to curative interventions. Recruitment of women in HIV clinical research is a pathway to both optimize care for women and to identify novel therapeutics for use in both men and women.

     

Genetic Cluster Analysis for HIV Prevention

Purpose of Review

This review summarizes the use of genetic similarity clusters to understand HIV transmission and inform prevention efforts.

Recent Findings

Recent emphases include the development of real-time cluster identification in order to interrupt transmission chains, the use of clusters to estimate rates of transmission along the HIV care cascade, and the extension of cluster analyses to understand transmission in the generalized epidemics of sub-Saharan Africa. Importantly, this recent empirical work has been accompanied by theoretical work that elucidates the processes that underlie HIV genetic similarity clusters; multiple studies suggest that clusters are not necessarily enriched with individuals with high transmission rates, but rather can reflect variation in sampling times within a population, with individuals sampled early in infection more likely to cluster.

Summary

Analyses of genetic similarity clusters have great promise to inform HIV epidemiology and prevention. Future emphases should include the collection of additional sequence data from underrepresented populations, such as those in sub-Saharan Africa, and further development and evaluation of clustering methods.

     

Treatment of Hepatitis C during Pregnancy-Weighing the Risks and Benefits in Contrast to HIV

Purpose of Review

Increasing hepatitis C virus (HCV) cases over the past decade have raised concerns about subsequent increased cases in infants due to mother to child transmission (MTCT). Many are reminded of the early days of HIV and the rationale for using antiretroviral agents during pregnancy.

Recent Findings

Direct-acting antivirals (DAAs) that are highly potent, all-oral, short-duration regimens that cure HCV have led many to consider what it would entail to use DAAs for pregnant women. Considering HIV and Hepatitis B virus (HBV) as two infections with MTCT to draw lessons from, DAA use to interrupt HCV MTCT comes with risks, costs, and many potential benefits.

Summary

When considering how to effectively curb the current epidemic of HCV in the US population, using DAAs to treat pregnant women with HCV offers potential benefits to the mother immediately, to the pair in the short-term and to the child, family, and society over a lifetime.