X-ray data collection from mineral crystals by means of a position-sensitive detector: Advantages and disadvantages

In order to check for the accuracy of X-ray diffracted data collected with an area-detector diffractometer (FAST-Nonius), we have carried out several data collections on a good-quality pyrope crystal (space group 1a3d; a = 11.479 \uc5) under different experimental settings and compared the results with those obtained with the same crystal mounted on a conventional Philips PW1100 diffractometer. Several parameters have been tested (detector gain, crystal-to-detector distance, frame width, integration time per image, beam intensity, shoebox size and re-measuring of overflow reflections), and four critical features of the system have been identified: the low thermal stability of the detector, its narrow dynamic range, the importance of the detector-to-crystal distance and the integration of the diffracted intensities. We are now able to select the best experimental settings in order to obtain a refinement from FAST diffraction data good as that from Philips data, in terms of Rsym, Robs and standard deviation of the refined parameters

Current management of pulmonary arterial hypertension.

Pulmonary arterial hypertension (PAH) is a vascular disease of unknown aetiology, characterised by an abnormal thickening of the arterial wall that is responsible for an increase in pulmonary vascular resistance. The haemodynamic consequence of PAH is an increased afterload for the right ventricle and, eventually, right heart failure. When untreated, PAH has a grim prognosis with a median survival of about 2 to 4 years from diagnosis. In the last 10 years new orally administered compounds have demonstrated clinical efficacy in controlled trials using various surrogate endpoints to survival. Although the disease remains without cure until now, the available phase III trials have allowed evidence-based recommendations for the medical management of these patients to be established. It appears, however, that none of the compounds from the three main therapeutic classes, endothelin receptor antagonists, agents acting on the nitric oxide-cyclic guanosine monophosphate pathway (including phosphodiesterase type 5 inhibitors and guanylate cyclase stimulator), and prostanoid receptor agonists are able alone to control disease progression in every patient. Therefore combination therapy with two or three drugs may be necessary in a significant number of patients in order to maintain patients in, or bring them to, a low risk profile. Several recent studies have now validated this approach for specific double or triple drug regimens. It remains, however, unclear whether an upfront combination is preferable to a sequential step-up approach based on clinical response. In addition, some specific combination therapies have failed to demonstrate superiority to single drug alone in randomised controlled trials. Besides PAH-specific treatment, the place of nonspecific pharmaceutical and nonpharmaceutical treatment has been also recently clarified

Money and power in household management: experiences of Black South African women

The aim of this thesis was to explore the experiences of black, married, working, South African women in relation to financial decision-making processes within private households from a working-woman’s perspective. The focus was on married women in middle and senior management positions in their workplaces. Following a literature review to accumulate empirical evidence from similar studies in the areas of Economics, Sociology, Psychology, Feminism and Economic Psychology, eight, individual, semi-structured interviews were conducted with black South African women in managerial positions to establish the women’s understanding of the meaning of money, concepts and practices of sharing of monetary resources between husband and wife in the household, the allocation of money as a resource in the household, control of money between husband and wife in the household, and decision-making processes between husband and wives. The key findings of the study were: · The diverse construction of the meaning of money. Women’s views on money had an impact on how they viewed their roles in household financial management and decision-making. · The absence of equal sharing of money and the existence of breadwinning/caregiver ideologies. Three patterns of money management were identified. Joint pooling, where equality of sharing, control and decision-making was greatest, was associated with higher income levels and availability of personal spending money. The female whole wage system, with minimal control and joint decision-making, was associated only with women with high-level income and minimal personal spending money. The independent managed system was associated with completely separate money management, unequal sharing of money, increased power, inequality in decision-making, and increased personal spending money by the breadwinner. · The pattern of financial allocation adopted had an influence on control and decision-making in the household. In all the systems of financial allocation adopted, women indicated that their partners had a final say in the financial decision-making processes. The study highlights some policy implications of inequality in financial decision-making. Due to the fact that household based analysis assumes that financial decision-making is shared equally in the households, women and children will most of the time lose out when this is not the case. It was therefore recommended that a deeper understanding of household decision-making may help the policy makers and researchers alike to focus on women in a more effective way, for example, by designing empowering programmes that will assist women to be involved in the financial planning and decision making in their households.Dissertation (MA (Research Psychology))--University of Pretoria, 2005.Psychologyunrestricte

Circulating calprotectin levels four months after severe and non-severe COVID-19.

BACKGROUND Calprotectin is an inflammatory marker mainly released by activated neutrophils that is increased in acute severe COVID-19. After initial recovery, some patients have persistent respiratory impairment with reduced diffusion capacity of the lungs for carbon monoxide (DLCO) months after infection. Underlying causes of this persistent impairment are unclear. We aimed to investigate the correlation between circulating calprotectin, persistent lung functional impairment and intensive care unit (ICU) stay after COVID-19 in two university hospital centres in Switzerland. METHODS Calprotectin levels were measured in serum from 124 patients (50% male) from the Bern cohort (post-ICU and non-ICU patients) and 68 (76% male) from the Lausanne cohort (only post-ICU patients) four months after COVID-19. Calprotectin was correlated with clinical parameters. Multivariate linear regression (MLR) was performed to evaluate the independent association of calprotectin in different models. RESULTS Overall, we found that post-ICU patients, compared to non-ICU, were significantly older (age 59.4 ± 13.6 (Bern), 60.5 ± 12.0 (Lausanne) vs. 48.8 ± 13.4 years) and more obese (BMI 28.6 ± 4.5 and 29.1 ± 5.3 vs. 25.2 ± 6.0 kg/m2, respectively). 48% of patients from Lausanne and 44% of the post-ICU Bern cohort had arterial hypertension as a pre-existing comorbidity vs. only 10% in non-ICU patients. Four months after COVID-19 infection, DLCO was lower in post-ICU patients (75.96 ± 19.05% predicted Bern, 71.11 ± 18.50% Lausanne) compared to non-ICU (97.79 ± 21.70% predicted, p < 0.01). The post-ICU cohort in Lausanne had similar calprotectin levels when compared to the cohort in Bern (Bern 2.74 ± 1.15 µg/ml, Lausanne 2.49 ± 1.13 µg/ml vs. non-ICU 1.86 ± 1.02 µg/ml; p-value < 0.01). Calprotectin correlated negatively with DLCO (r= -0.290, p < 0.001) and the forced vital capacity (FVC) (r= -0.311, p < 0.001). CONCLUSIONS Serum calprotectin is elevated in post-ICU patients in two independent cohorts and higher compared to non-ICU patients four months after COVID-19. In addition, there is a negative correlation between calprotectin levels and DLCO or FVC. The relationship between inflammation and lung functional impairment needs further investigations. TRIAL REGISTRATION NCT04581135

Frailty assessment for COVID-19 follow-up: a prospective cohort study.

BACKGROUND The Clinical Frailty Scale (CFS) is increasingly used for clinical decision making in acute care but little is known about frailty after COVID-19. OBJECTIVES To investigate frailty and the CFS for post-COVID-19 follow-up. METHODS This prospective multicentre cohort study included COVID-19 survivors aged ≥50 years presenting for a follow-up visit ≥3 months after the acute illness. Nine centres retrospectively collected pre-COVID-19 CFS and prospectively CFS at follow-up. Three centres completed the Frailty Index (FI), the short physical performance battery (SPPB), 30 s sit-to-stand test and handgrip strength measurements. Mixed effect logistic regression models accounting for repeated measurements and potential confounders were used to investigate factors associated with post-COVID-19 CFS. Criterion and construct validity were determined by correlating the CFS to other concurrently assessed frailty measurements and measures of respiratory impairment, respectively. RESULTS Of the 288 participants 65% were men, mean (SD) age was 65.1 (9) years. Median (IQR) CFS at follow-up was 3 (2-3), 21% were vulnerable or frail (CFS ≥4). The CFS was responsive to change, correlated with the FI (r=0.69, p<0.001), the SPPB score (r=-0.48, p<0.001) (criterion validity) and with the St George's Respiratory Questionnaire score (r=0.59, p<0.001), forced vital capacity %-predicted (r=-0.25, p<0.001), 6 min walk distance (r=-0.39, p<0.001) and modified Medical Research Council (mMRC) (r=0.59, p<0.001). Dyspnoea was significantly associated with a higher odds for vulnerability/frailty (per one mMRC adjusted OR 2.01 (95% CI 1.13 to 3.58), p=0.02). CONCLUSIONS The CFS significantly increases with COVID-19, and dyspnoea is an important risk factor for post-COVID-19 frailty and should be addressed thoroughly

Case Report: Stepwise Anti-Inflammatory and Anti-SARS-CoV-2 Effects Following Convalescent Plasma Therapy With Full Clinical Recovery.

In these times of COVID-19 pandemic, concern has been raised about the potential effects of SARS-CoV-2 infection on immunocompromised patients, particularly on those receiving B-cell depleting agents and having therefore a severely depressed humoral response. Convalescent plasma can be a therapeutic option for these patients. Understanding the underlying mechanisms of convalescent plasma is crucial to optimize such therapeutic approach. Here, we describe a COVID-19 patient who was deeply immunosuppressed following rituximab (anti-CD20 monoclonal antibody) and concomitant chemotherapy for chronic lymphoid leukemia. His long-term severe T and B cell lymphopenia allowed to evaluate the treatment effects of convalescent plasma. Therapeutic outcome was monitored at the clinical, biological and radiological level. Moreover, anti-SARS-CoV-2 antibody titers (IgM, IgG and IgA) and neutralizing activity were assessed over time before and after plasma transfusions, alongside to SARS-CoV-2 RNA quantification and virus isolation from the upper respiratory tract. Already after the first cycle of plasma transfusion, the patient experienced rapid improvement of pneumonia, inflammation and blood cell counts, which may be related to the immunomodulatory properties of plasma. Subsequently, the cumulative increase in anti-SARS-CoV-2 neutralizing antibodies due to the three additional plasma transfusions was associated with progressive and finally complete viral clearance, resulting in full clinical recovery. In this case-report, administration of convalescent plasma revealed a stepwise effect with an initial and rapid anti-inflammatory activity followed by the progressive SARS-CoV-2 clearance. These data have potential implications for a more extended use of convalescent plasma and future monoclonal antibodies in the treatment of immunosuppressed COVID-19 patients

Candida Colonization Index in Patients Admitted to an ICU

Multiple-site colonization with Candida spp. is commonly recognized as a risk factor for invasive fungal infection in critically ill patients. We carried out a study to determine the relationship between Candida colonization and invasive infection in neurological patients admitted to an ICU. At admission (T0) and every three days for two weeks, different samples (pharynx swab, tracheal secretions, stomach contents, etc.) were collected for mycological surveillance. Candida mannan antigen and Candida anti-mannan antibodies were assayed. The Colonization Index (CI) and Corrected Colonization Index were calculated for each time point. Of all patients 70% was already colonized by Candida spp. at T0 and six of them had CI ≥ 0.5. Three patients developed candidemia; they had CI ≥ 0.5 before infection. Positive values of Candida mannan antigen and anti-mannan antibodies were found only in the patients with candidemia. The sensitivity and specificity of the Candida mannan test were 66.6% and 100%, respectively, while the sensitivity and specificity of the anti-mannan antibody test were 100%. In accordance with other authors, we find the surveillance cultures are useful to monitor the Candida colonization in ICU patients. In addition, the sequential observation of anti-mannan antibodies could contribute to early diagnosis of candidiasis more than Candida mannan antigen in immunocompetent patients

Pulmonary Recovery 12 Months after Non-Severe and Severe COVID-19: The Prospective Swiss COVID-19 Lung Study.

BACKGROUND Lung function impairment persists in some patients for months after acute coronavirus disease 2019 (COVID-19). Long-term lung function, radiological features, and their association remain to be clarified. OBJECTIVES We aimed to prospectively investigate lung function and radiological abnormalities over 12 months after severe and non-severe COVID-19. METHODS 584 patients were included in the Swiss COVID-19 lung study. We assessed lung function at 3, 6, and 12 months after acute COVID-19 and compared chest computed tomography (CT) imaging to lung functional abnormalities. RESULTS At 12 months, diffusion capacity for carbon monoxide (DLCOcorr) was lower after severe COVID-19 compared to non-severe COVID-19 (74.9% vs. 85.2% predicted, p < 0.001). Similarly, minimal oxygen saturation on 6-min walk test and total lung capacity were lower after severe COVID-19 (89.6% vs. 92.2%, p = 0.004, respectively, 88.2% vs. 95.1% predicted, p = 0.011). The difference for forced vital capacity (91.6% vs. 96.3% predicted, p = 0.082) was not statistically significant. Between 3 and 12 months, lung function improved in both groups and differences in DLCO between non-severe and severe COVID-19 patients decreased. In patients with chest CT scans at 12 months, we observed a correlation between radiological abnormalities and reduced lung function. While the overall extent of radiological abnormalities diminished over time, the frequency of mosaic attenuation and curvilinear patterns increased. CONCLUSIONS In this prospective cohort study, patients who had severe COVID-19 had diminished lung function over the first year compared to those after non-severe COVID-19, albeit with a greater extent of recovery in the severe disease group

Comparison of two protective lung ventilatory regimes on oxygenation during one-lung ventilation: a randomized controlled trial

<p>Abstract</p> <p>Background</p> <p>The efficacy of protective ventilation in acute lung injury has validated its use in the operating room for patients undergoing thoracic surgery with one-lung ventilation (OLV). The purpose of this study was to investigate the effects of two different modes of ventilation using low tidal volumes: pressure controlled ventilation (PCV) vs. volume controlled ventilation (VCV) on oxygenation and airway pressures during OLV.</p> <p>Methods</p> <p>We studied 41 patients scheduled for thoracoscopy surgery. After initial two-lung ventilation with VCV patients were randomly assigned to one of two groups. In one group OLV was started with VCV (tidal volume 6 mL/kg, PEEP 5) and after 30 minutes ventilation was switched to PCV (inspiratory pressure to provide a tidal volume of 6 mL/kg, PEEP 5) for the same time period. In the second group, ventilation modes were performed in reverse order. Airway pressures and blood gases were obtained at the end of each ventilatory mode.</p> <p>Results</p> <p>PaO₂, PaCO₂and alveolar-arterial oxygen difference did not differ between PCV and VCV. Peak airway pressure was significantly lower in PCV compared with VCV (19.9 ± 3.8 cmH₂O vs 23.1 ± 4.3 cmH₂O; p < 0.001) without any significant differences in mean and plateau pressures.</p> <p>Conclusions</p> <p>In patients with good preoperative pulmonary function undergoing thoracoscopy surgery, the use of a protective lung ventilation strategy with VCV or PCV does not affect the oxygenation. PCV was associated with lower peak airway pressures.</p