REVIEW | doi:10.20944/preprints202007.0079.v1
Subject: Medicine & Pharmacology, Other Keywords: animal models; experimental models; SARS-CoV-2; COVID-19; rhesus macaque; monkey; hamster; ferrets; transgenic mice
Online: 5 July 2020 (15:07:53 CEST)
Background: The use of animal models for biomedical research provides us with a convenient and feasible route to establish causal relationships by recapitulating the temporal sequence of events in a controlled environment with a potential to manipulate the variables at multiple levels including genetic, protein, physiological or environmental. Objectives: The current review was conducted to gain insights into various animal models for the SARS-CoV-2 virus. Material and Methods: A literature review (PUBMED, PUBMED Central, PMC, Google Scholar, Google search engine) following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines performed in early April 2020 revealed 9 articles of interest. Search terms included covid 19, covid-19, novel corona virus, SARS-CoV-2, animal models, experimental models, laboratory models & covid 19 animal models. Two independent reviewers extracted the data; the third reviewer was involved in case of discrepancy. Results: SARS-CoV-2 shares an identical receptor binding domain with the SARS-CoV virus and has a superior binding affinity to the host ACE2. Based on this, the role of rhesus macaques, golden Syrian hamsters, transgenic hACE2 mice and ferrets as animal models have been studied. All four animals are susceptible to infection with SARS-CoV-2 with variable clinical presentation but universal recovery. The respiratory tract is primarily involved in all four models. Involvement of intestines was also seen in at least one study in each animal. Transfer to naïve animals in close contact has been documented in case of hamsters and ferrets. Seroconversion was documented in all although the role of convalescent sera was tested in hamsters only, with positive results though. Air-borne transmission was documented in ferrets and the possibility of feco-oral transmission was suggested for hamsters. The possibilities of recurrence and re-infection were ruled out by experiments upon the rhesus macaques. The fulfilment of Koch’s postulates has been highlighted. Discussion: The various studies available on animal models have been able to establish models of infection and transmission that recapitulate different aspects of disease in humans. However, the response between different animals and the same animal in different experiments is not completely coherent. Some of them do not manifest the disease clinically while others behave differently at molecular and immunological levels. Moreover, the physiology of these animals is not identical to human beings and the findings may not be extrapolated to human beings in an ‘as-is’ manner. Conclusions: The review acknowledges the achievements made by these experiments in a short span of time and highlighted the urgent need for a deeper dive in search of a quintessential animal model which can be studied for efficacy and safety of newer drugs and vaccines before a make-shift from the petri-dish to the human body can be contemplated.
Subject: Medicine & Pharmacology, General Medical Research Keywords: COVID-19; SARS-CoV-2; coronavirus; severe acute respiratory syndrome coronavirus
Online: 5 July 2020 (10:16:43 CEST)
Background: The information on the difference in clinical characteristics between severe and non-severe cases is limited in some countries including Iran. The objective of this case series is to compare the clinical characteristics, radiologic features, and laboratory findings between COVID-19 severe cases who received the intensive care unit (ICU) care with non-severe cases who did not receive ICU care. Methods: In this retrospective cohort study, 186 laboratory-confirmed patients with COVID-19 diagnosed from 1 March 2020 to 30 March 2020 were investigated. Results: This study population included 186 hospitalized patients with confirmed COVID-19. The median age was 47 years, and 88 (47.31%) were female. Of these patients, 48 were admitted and transferred to ICU. Of 186 patients, 44.62% had medical comorbidities including hypertension and diabetes. The most common clinical manifestation were shortness of breath 86.56%, myalgia 74.19%, and headache. Higher neutrophil counts, CRP, and LDH as well as the lower levels of lymphocytes were the most important laboratory finding among COVID-19 patients. As of April 15, 2020, 33 were still hospitalized. A total of 116 patients (62.70 %) had been discharged, and 36 patients (19.94 %) had died. Of the 48 patients admitted to the ICU, 33.33% have died. Conclusion: In the present study, shortness of breath was the most common clinical symptom, and the mortality rate in patients admitted to the ICU was about 33%, indicating that about one-third of patients with severe illness who admitted to the ICU section died.
ARTICLE | doi:10.20944/preprints202007.0058.v1
Subject: Medicine & Pharmacology, Nutrition Keywords: Rural; Food System; Inequities; Disparities; Food Security
Online: 5 July 2020 (09:13:17 CEST)
We seek to elucidate an aspirational vision for the food system and explore whether the characteristics of such a system inadvertently set unattainable standards for rural, low wealth communities. We apply discourse analysis to the following qualitative datasets: (1) interviews with food experts and advocates, (2) scholarly and grey literature, (3) industry websites, and (4) email exchanges between food advocates. The analysis revealed eight aspirational food system discourses: Production, Distribution, and Infrastructure; Healthy, Organic, Local Food; Behavioral Health and Education; Sustainability; Finance and Investment; Huger Relief; Demand Side Preferences; Romanticized, Community Led Transformations. Study findings reveal that of eight discourses only three encompass the experiences of rural, low wealth residents. This aspirational food system may result in the disempowerment of the needs of rural, low wealth groups; a perpetuation of the failure of groups who will be unable to reach the aspirational food vision; silencing of discourses that might question those that play a role in the inequitable distribution of income while sanctioning discourses that focus on personal or community solutions; and the absence of other policy-based solutions that address issues located within the food system. Further research is needed to inform policies and programs to mitigate food insecurity in rural, low wealth populations.
ARTICLE | doi:10.20944/preprints202007.0050.v1
Subject: Medicine & Pharmacology, Other Keywords: positive deviance; dual-method use; contraception; unintended pregnancy; sexually transmitted infection; HIV/AIDS
Online: 5 July 2020 (07:04:27 CEST)
Dual-method use is the most reliable form of protection against unintended pregnancies and HIV/STIs. Although dual-method use remains uncommon among women in stable relationships, some women do practice it. In this study, we explored the barriers that make dual-method use rare and the behaviors of women who practice dual-method use using a positive deviance framework in Uganda. We screened 150 women using highly effective contraceptives at five health facilities. We identified nine women who practiced dual-method use and 141 women who did not. In a qualitative study, we conducted in-depth interviews with all nine women practicing dual-method use and 10 women randomly selected out of the 141 who did not. We performed a thematic analysis using the positive deviance framework. Regardless of practicing dual-method use or not, women faced perceived barriers against dual-method use, such as partner’s objection, distrust, shyness about introducing condoms into marital relationships, and limited access to condoms. However, women practicing dual-method use had higher levels of risk perception about unintended pregnancies and HIV/STIs. They also engaged in unique behaviors, such as influencing their partners’ condom use by initiating discussions, educating their partners on sexual risks and condom use, and obtaining condoms by themselves. These findings will be useful in developing effective community-led and peer-based interventions promoting dual-method use to reduce the dual burden of unintended pregnancies and HIV/STIs among women in Uganda.
ARTICLE | doi:10.20944/preprints202007.0046.v1
Subject: Medicine & Pharmacology, General Medical Research Keywords: Hantavirus cardiopulmonary syndrome; Hantavirus pulmonary syndrome; extracorporeal membrane oxygenation; transpulmonary thermodilution; high volume hemofiltration; Andes Hantavirus
Online: 5 July 2020 (05:24:11 CEST)
Background: Hantavirus cardiopulmonary syndrome (HCPS) has a high lethality. About two-thirds of the severe cases may be rescued by extracorporeal membrane oxygenation (ECMO). However, about half of the patients supported by ECMO suffer major complications. High volume hemofiltration (HVHF) is a depurative extracorporeal support that provides homeostatic balance allowing hemodynamic stabilization in some critically ill patients. Methods: We implemented HVHF prior to ECMO consideration in the last five severe HCPS patients requiring mechanical ventilation and vasoactive drugs admitted to our intensive care unit. Patients were considered HVHF-responders if ECMO was avoided and nonresponders if ECMO support was needed. Results: The first two patients required ECMO, while the last three did not. Patients had a maximum serum lactate of 8.4 [4.3-14] mMol/L and a lowest cardiac index of 1.76 [1.45-2.9] L/min/m2. Nonresponders were connected later to HVHF, displayed progressive tachycardia and decreasing stroke volume. The opposite was true for HVHF-responders who also received targeted-HVHF compounded by aggressive hyperoncotic albumin, sodium bicarbonate and calcium supplementation plus ultrafiltration to avoid fluid overload. All patients survived, but one of the ECMO patients suffered a vascular complication. Conclusion: HVHF may contribute to support severe HCPS patients avoiding the need for ECMO in some of them. Early connection and targeted-HVHF may increase the chance of success.
ARTICLE | doi:10.20944/preprints202007.0045.v1
Subject: Medicine & Pharmacology, Psychiatry & Mental Health Studies Keywords: Chronic hepatitis C; Direct-acting antiviral agents; Hepatitis C virus; Consultation-liaison psychiatry; Depression; Anxiety
Online: 5 July 2020 (05:15:08 CEST)
In chronic hepatitis C (CHC) patients, interferon-based treatments showed toxicity, limited efficacy, and psychiatric manifestations. Direct-acting antiviral (DAA) agents appeared safer, though it remains unclear if they may exacerbate or foster mood symptoms in drug-naïve CHC patients. We evaluated 62 CHC patients’ mental status, before and 12 weeks after DAA therapy, by assessment scales and psychometric instruments. We subdivided patients into two groups, CHC patients with (Group A) or without (Group B) a current and/or past psychiatric history. After DAA treatment, Group A patients showed low anxiety and improved depression, no variation in self-report distress, but worse general health perceptions. No significant difference emerged from coping strategies. Depression and anxiety improved in Group B, and no change emerged from total self-reported distress, except for somatization. Moreover, Group B increased problem-focused strategies for suppression of competing activities, and decreased strategies of instrumental social support. Contrarily, Group B reduced significantly emotion-focused strategies, such as acceptance and mental disengagement, and improved vitality, physical and social role functioning. DAA therapy is safe and free of hepatological and psychiatric side effects in CHC patients, regardless of current and/or past psychiatric history. In particular, patients without a psychiatric history also remarkably improved their quality of life.
REVIEW | doi:10.20944/preprints202007.0041.v1
Subject: Medicine & Pharmacology, Oncology & Oncogenics Keywords: Multiple myeloma; myeloma bone disease; pathophysiology; osteolysis; imaging; zoledronic acid; denosumab; vertebral augmentation; rehabilitation; exercise
Online: 5 July 2020 (04:19:18 CEST)
The lytic bone disease is a hallmark of multiple myeloma, being present in about 80% of patients with newly diagnosed MM, and in more during the disease course. The myeloma associated bone disease (MBD) severely affects the morbidity and quality of life of the patients. MBD defines treatment demanding MM. In recent years, knowledge of the underlying pathophysiology has increased, and novel imaging technologies, medical and non-pharmaceutical treatments have improved. In this review, we highlight the major achievements in understanding, diagnosing and treating MBD. For diagnosing MBD, low-dose whole-body CT is now recommended over conventional skeletal survey, but also more advanced functional imaging modalities, such as diffusion-weighted MRI and PET/CT are increasingly important in the assessment and monitoring of MBD. Bisphosphonates have, for many years, played a key role in management of MBD, but denosumab is now an alternative to bisphosphonates, especially in patients with renal impairment. Radiotherapy is used for uncontrolled pain, for impeding fractures and in treatment of impeding or symptomatic spinal cord compression. Cement augmentation has been shown to reduce pain from vertebral compression fractures. Cautious exercise programs are safe and feasible and may have the potential to improve the status of patients with MM.