Parenchymal involvement on CT pulmonary angiography in SARS-CoV-2 Alpha variant infection and correlation of COVID-19 CT severity score with clinical disease severity and short-term prognosis in a UK cohort

AIM

To determine if there is a difference in radiological, biochemical, or clinical severity between patients infected with Alpha-variant SARS-CoV-2 compared with those infected with pre-existing strains, and to determine if the computed tomography (CT) severity score (CTSS) for COVID-19 pneumonitis correlates with clinical severity and can prognosticate outcomes.

MATERIALS AND METHODS

Blinded CTSS scoring was applied to 137 hospital patients who had undergone both CT pulmonary angiography (CTPA) and whole-genome sequencing of SARS-CoV-2 within 14 days of CTPA between 1/12/20–5/1/21.

RESULTS

There was no evidence of a difference in imaging severity on CTPA, viral load, clinical parameters of severity, or outcomes between Alpha and preceding variants. CTSS on CTPA strongly correlates with clinical and biochemical severity at the time of CTPA, and with patient outcomes. Classifying CTSS into a binary value of “high” and “low”, with a cut-off score of 14, patients with a high score have a significantly increased risk of deterioration, as defined by subsequent admission to critical care or death (multivariate hazard ratio [HR] 2.76, p<0.001), and hospital length of stay (17.4 versus 7.9 days, p<0.0001).

CONCLUSION

There was no evidence of a difference in radiological severity of Alpha variant infection compared with pre-existing strains. High CTSS applied to CTPA is associated with increased risk of COVID-19 severity and poorer clinical outcomes and may be of use particularly in settings where CT is not performed for diagnosis of COVID-19 but rather is used following clinical deterioration.

Assessing the safety of del Nido cardioplegia solution in adult congenital cases

PURPOSE

del Nido cardioplegia solution (CPS) has been successfully used for myocardial protection in the pediatric population. We propose this solution can be used safely in adult congenital patients. The proposed benefit of this solution is the avoidance of the need for repetitive interruption of the operation to administer multiple doses of standard cardioplegia.

METHODS

As part of a quality improvement initiative, 47 consecutive adult patients (mean age 40.9 years, range 18-71) undergoing congenital heart surgery were given del Nido CPS. Cardiac function was assessed pre- and post-operatively by echocardiography (ECHO). Inotrope use, troponin levels and restoration of cardiac rhythm were also evaluated.

RESULTS

The average duration of the longest ischemic time was 52.5 minutes ± 15.57 minutes. In patients receiving a single dose (40%, n=19) of CPS, the average ischemic time was 49.8 minutes ± 18.8 minutes. No patients demonstrated any ventricular electrical activity while the aorta was cross-clamped. Post-operative ECHO showed that 94% (n=44) had no change in ejection fraction from the pre-operative ECHO. Patients requiring inotropic support at the time of leaving the operating room (OR) was 43% (n=20). The percentage of patients requiring inotropic support twenty-four hours post-operatively was 17% (n=8). Spontaneous restoration of cardiac rhythm (without the need for defibrillation) after cross-clamp removal occurred in 91% (n=43) of patients. The average troponin T level post-op was 1.86 ± 2.9 µg/L.

CONCLUSIONS

del Nido CPS can be used for myocardial protection during adult congenital cardiac surgery without any apparent adverse effects. In addition, we were able to change our re-dosing protocol to 45 minutes with del Nido CPS compared to 20 minutes with our adult 4:1 blood CPS.

Carboxyhemoglobinemia in a pediatric cardiopulmonary bypass patient derived from a contaminated unit of allogenic blood

A 4.3 kg, three-month-old patient, diagnosed with a perimembranous ventricular septal defect, presented for cardiac surgery. Upon initiation of cardiopulmonary bypass (CPB), the patient developed carboxyhemoglobinemia (11.1%). Potential sources for the unexpected acquired carboxyhemoglobinemia were sought quickly. Testing of residual blood from the unit of packed red blood cells (PRBCs) used to prime the CPB circuit revealed a carboxyhemoglobin (COHb) of 15.1 %. A decrease in cerebral oximetry (rSO2) on CPB was initially felt to be a result of the elevated COHb levels. When ventilation of the oxygenator with 100% oxygen (O2) failed to decrease COHb levels, a partial exchange transfusion was performed with reduction in COHb to 7.1%. The operation was completed successfully and the patient’s COHb levels returned to normal within 75 minutes.

Post case analysis of events and data collected during the case revealed a broader differential for explaining the compromised patient’s O2 delivery than the transient acquired carboxyhemoglobinemia. A partial obstruction of the superior vena cava could have triggered the drop in rSO2 on CPB.

Follow-up of the donor blood confirmed the donor had previously undiagnosed carboxyhemoglobinemia as a result of chronic carbon monoxide exposure from a faulty vehicle exhaust system.

A clinical evaluation of the Dideco Kids D100 neonatal oxygenatora

In August 2006, Duke University Perfusion Services had the opportunity to be the first institution in the United States to clinically evaluate the Dideco D100 Neonatal Oxygenator. The device was used on six pediatric patients to facilitate correction or palliation of their cardiac defects, which included two arterial switch operations, two truncus arteriosus repairs, one stage 1 Norwood and one repair of total anomalous pulmonary venous return. The average patient weight was 3.1 kg. The average cardiopulmonary bypass(CPB) time was 135 minutes and the average cross-clamp time was 61 minutes. Arterial and venous blood gasses were drawn and used to calculate oxygen transfer. The average oxygen transfer was 14.8 ± 10.3 ml/O2/min. The Dideco D100 Oxygenator is the first oxygenation device designed specifically for neonates. The Dideco D100 is a microporous hollow-fiber device. It has a static priming volume of 31 ml and a maximum rated flow of 700 ml/min. The integral hard-shell venous reservoir has a minimum operating level of 10 ml and a reservoir capacity of 500 ml. For this evaluation, the Dideco Kids D100 Neonatal Oxygenator performed adequately on patients weighing up to 5 kg. This device provides an excellent first step towards offering very small children appropriate circuitry without having to sacrifice safety or performance.

Monoclonal antibodies recognizing CD5, CD10 and CD23 in formalin-fixed, paraffin-embedded tissue: production and assessment of their value in the diagnosis of small B-cell lymphoma

AIMS

Assessment of the expression of antigens CD5, CD10 and CD23 can be of value in the differential diagnosis of small B-cell lymphoma. Correct subclassification is important since optimal treatment regimes differ between the subtypes. The aim of this study was to generate monoclonal antibodies recognizing these antigens in paraffin-embedded tissue and to assess their efficacy using a panel of cases of small B-cell lymphoma of various subtypes.

METHODS AND RESULTS

For each antibody synthetic recombinant protein and conventional murine hybridoma technology was employed. Monoclonal antibodies effective in formalin-fixed, paraffin-embedded tissue were successfully generated, designated NCL-CD5-4C7, NCL-CD10-270 and NCL-CD23-1B12, respectively. A series of 58 cases of small B-cell lymphoma including examples of each subtype (lymphocytic, follicle centre cell, mantle cell, marginal zone and lymphoplasmacytoid) was assembled and immunostaining for the respective antigens carried out using the monoclonal antibodies produced. Our results indicate that the antibodies are specific for their respective antigens and give the predicted phenotypic profile in the small B-cell lymphoma subtypes.

CONCLUSIONS

These novel monoclonal antibodies may be of value in routine diagnostic practice.

Mini-circuit cardiopulmonary bypass with vacuum assisted venous drainage: feasibility of an asanguineous prime in the neonate

Conventional cardiopulmonary bypass (CPB) in neonates results in increased transfusion requirements and hemodilution. There has been little advancement in CPB for the neonatal population. There is evidence that increased priming volumes and blood product transfusion enhances inflammatory response to CPB and increases myocardial and pulmonary dysfunction. We have devised a miniaturized CPB circuit that utilizes vacuum-assisted venous drainage (VAVD) in an effort to decrease priming volume and avoid transfusion requirements. The purpose of this study was to evaluate the safety and efficacy of this miniaturized CPB system and determine the feasibility of an asanguineous prime. Ten 1-week-old piglets were randomized to five mini- and five conventional CPB pump circuits. Subjects were supported with CPB at 100 ml/kg/min, cooled to 28 degrees C, exposed to 10 min aortic crossclamp with cardioplegic arrest, rewarmed to 37 degrees C, weaned from bypass, and subjected to modified-ultrafiltration (MUF) for approximately 10 min. This method was chosen to simulate a situation with all the elements of clinical CPB. Blood transfusion trigger was a hematocrit <15 on CPB. Serum samples were obtained pre-CPB, at 15 min of CPB onset, immediately post-CPB completion, and immediately post-MUF. Indices of hemolysis (SGOT, LDH), production of inflammatory mediators (interleukin (IL)-8, tumor necrosis factor-alpha (TNFalpha)), and physiologic parameters of inflammation were measured. The overall blood requirement was significantly less in the mini-circuit compared to conventional CPB (47.0+/-5.8 ml vs 314.2+/-31.6 ml; p < 0.0001). The only significant blood requirement in the mini-circuit was to replace the volume removed for samples. During the study, mean arterial pressure (MAP) (p = 0.004), static pulmonary compliance (p = 0.04), platelets (p = 0.0003), and white blood cells (p = 0.003) significantly decreased across the groups. Lung water content (p = 0.02), TNFalpha levels (p = 0.05), and SGOT (p = 0.009) increased significantly during the study, across the groups. Among all parameters tested, except for blood requirement and hematocrit post-CPB, there were no significant differences between the two circuits. VAVD makes asanguineous prime in neonates feasible. When used in this study to miniaturize a conventional-CPB circuit, VAVD with a reconfigured neonatal CPB console and circuit resulted in no detrimental effects, and allowed for markedly decreased priming volumes and blood transfusion requirements.

Song as an indicator of parasitism in the sedge warbler

We studied female choice and reproductive success in a marked population of sedge warblers Acrocephalus schoenobaenus, from 1995 to 1996. Three genera of parasitic blood protozoans, namely Haemoproteus sp. Trypanosoma sp. Plasmodium sp., were identified from blood samples taken from all breeding adults. Relatively high prevalence values of 19.5% in 1995 and 37.5% in 1996 were associated with increased levels of white blood cells relative to the number of red blood cells. Compared with nonparasitized males, parasitized males had significantly lower repertoire sizes in both years of the study; in one year, they also spent less time in song flights and weighed less. They also provisioned their broods at a lower rate. Parasitized females produced the same clutch size as nonparasitized females, although their broods were smaller at 7 days old. We suggest that haematozoan infections may reduce the expression of sexually selected song traits. Furthermore, such infections may influence the standard of parental care provided by males, although further research is needed to determine whether this is mediated through genetic resistance to parasitism or the effects of parasitism upon immediate body condition. Copyright 1999 The Association for the Study of Animal Behaviour.

A multicentre, double-blind, amitriptyline-controlled study of mirtazapine in patients with major depression

BACKGROUND

the efficacy and tolerability of the new antidepressant mirtazapine were evaluated in a multicentre, randomized, double-blind, amitriptyline-controlled, 5 week clinical study.

METHOD

156 patients with a DSM-III diagnosis of major depressive episode and 21-item Hamilton Psychiatric Rating Scale for Depression (HPRSD) score ≥ 18, were randomized to treatment with either mirtazapine 20-60 mg/day or amitriptyline 75-225 mg/day.

RESULTS

mirtazapine and amitriptyline were equally effective in reducing depressive symptoms, as assessed by the 17-item HPRSD and MADRS scales. Mirtazapine was better tolerated than amitriptyline, with fewer drop-outs due to adverse events and lower incidences of adverse events both at the beginning and at the end of the trial.

CONCLUSION

this study shows that mirtazapine is as effective as amitriptyline in treating major depression, while at the same time better tolerated.

A survey of psychiatric patients' views of outpatient clinic facilities

Psychiatric services have been slow to solicit the views of their patients about quality. This study asked attenders at an outpatient clinic at a large psychiatric teaching hospital about their opinions on the referral process, waiting time, access, waiting within the clinic, consultations, and overall satisfaction. Response rates were 86% and 70% for the two parts of an interviewer-administered, structured questionnaire. A range of criticisms and concerns were identified, some of which have since been addressed by practical measures. Overall satisfaction was related to the quality of communication within the consultation and to the length of waiting time from referral to appointment. The study confirms the practicality of consumer studies in a psychiatric setting.

Clinical and experimental aspects of viral myocarditis

Picornaviruses are frequently implicated as the etiological agents of acute myocarditis. This association is based historically on serological evidence of rising antibody titers to specific pathogens and more recently on identification of viral genomic material in endocardial biopsy specimens through in situ hybridization. Only rarely is infectious virus isolated from either the patient or the heart during periods of maximum myocardial inflammation and injury. Thus, despite a probable viral etiology, much interest centers on the role of the immune system in cardiac damage and the likelihood that the infection triggers an autoimmune response to heart-specific antigens. Heart-reactive antibodies and T cells are found in most myocarditis patients, and immunosuppressive therapy has proven beneficial in many, though not all, cases. Furthermore, murine models of coxsackievirus group B type 3-induced myocarditis also demonstrate that virus infection initiates autoimmunity and that these autoimmune effectors are predominately responsible for tissue injury. How virus-host interactions overcome presumed self-tolerance to heart antigens is discussed, and evidence supporting various theories of virus-initiated autoimmunity and disease pathogenesis are delineated.