A multidisciplinary evaluation of suspected, non-confirmed cases of COVID-19 including chest CT, as compared to World Health Organization recommendations.

AIM: To report an audit of the evaluation of suspected, unconfirmed cases of COVID-19 including chest computed tomography (CT), as compared to World Health Organization recommendations. METHODS: A clinical audit was undertaken examining the evaluation of patients with suspected COVID-19 with negative SARS-CoV-2 reverse transcriptase polymerase chain reaction (RT-PCR) results, with comparison to WHO recommendations. A retrospective chart review was undertaken for 90 patients examining investigations, in particular CT, used to clarify the diagnosis. RESULTS: Ninety patients underwent additional investigation. Seventy-five per cent adherence to WHO recommendations was observed. Fifty-two men (57.78%) and 38 (42.22%) women were investigated, with a median age of 69 years (range 20-96 years). Seventy-nine chest CT examinations demonstrated positive, indeterminate, and negative rates for COVID-19 of 3.79%, 24.1%, and 72.15% respectively. Three patients had discordant swab results with initially negative and subsequently positive results for SARS-CoV-2, resulting in false-negative rates of 5.1% for those retested. Combining discordant RT-PCR swab results, positive radiology, and patients treated as COVID-19-positive due to indeterminate radiology and highly consistent symptoms, resulted in a false-negative rate for initial SARS-CoV-2 RT-PCR swabs of 16.67%. CONCLUSION: Seventy-five per cent compliance with relevant WHO guidance and a false-negative rate for initial swabs of 16.67% was demonstrated. Further evidence is needed to fully determine the utility of chest CT in the diagnosis of COVID-19 in the context of initial false-negative RT-PCR results.

Declining incidence of keratinocyte carcinoma in organ transplant recipients.

BACKGROUND: All organ transplant populations are predisposed to increased rates of keratinocyte carcinoma (KC). Since this increased risk was first appreciated, immunosuppressive regimens have changed and organ transplant recipients (OTRs) have been aggressively screened for KC. There is a perception that these measures have impacted on KC incidence but there is a paucity of population-based studies on post-transplant rates of basal cell carcinoma (BCC). OBJECTIVES: To identify trends in incidence rates for KC following solid organ transplantation over the past two decades. METHODS: This nationwide, population-based study included all solid OTRs transplanted between 1994 and 2014. Patient data were matched to national cancer registry data to determine the standardized incidence ratio (SIR) of KC in solid OTRs compared with the general population. RESULTS: In total 3580 solid OTRs were included. The total follow-up time was 28 407 person-years (median follow-up 7·11 years). The overall SIRs for squamous cell carcinoma (SCC) and BCC were 19·7 and 7·0, respectively. Our study documents a progressive fall in the SIRs for SCC and BCC from peak SIRs (95% confidence intervals) in 1994-1996 of 26·4 (21·5-32·4) and 9·1 (7·4-11·3) to 6·3 (2·3-16·7) and 3·2 (1·4-7·1) in 2012-2014, respectively. The ratio of SCC to BCC has remained at 3 to 1 over the last two decades. CONCLUSIONS: Our study is the first to demonstrate a significant reduction over the past two decades in the incidences of both SCC and BCC following solid organ transplantation. The SCC-to-BCC ratio was maintained, demonstrating that both are reducing equally. This trend coincided with temporal changes in immunosuppressive protocols and the introduction of skin cancer prevention programmes. What's already known about this topic? Prior studies have shown that the risk of cutaneous squamous cell carcinoma (SCC) has declined over recent decades following solid organ transplantation. It is not known whether the risk of basal cell carcinoma (BCC) has reduced in line with this. What does this study add? Our study documents a progressive fall in the risk of SCC and BCC following solid organ transplantation over the last two decades. The SCC-to-BCC ratio was maintained, demonstrating that both are reducing equally. The trends observed in our study coincided with temporal changes in immunosuppressive protocols and the introduction of cancer prevention programmes, suggesting that these factors have positively impacted on the risk of keratinocyte carcinoma in this cohort.

Acute Respiratory Failure Post Single Lung Transplantation: An Unusual Cause.

Vascular complications of pulmonary vessels post-transplant are rare but are associated with high morbidity and mortality. We describe the first published case of surgical management of pulmonary vein stenosis complicated by early thrombosis post single lung transplantation. This report describes early diagnostic techniques and subsequent management options in such patients where pulmonary vascular complications are a potential.

The Efficacy of Bronchial Thermoplasty for Severe Persistent Asthma: The First National Experience.

There is an unmet need for new therapies in severe persistent asthma. Bronchial thermoplasty is a bronchoscopic procedure which employs radiofrequency energy to reduce airway smooth muscle and has been demonstrated to improve symptomatic control in severe persistent asthma in other populations. Seven patients have completed bronchial thermoplasty at a tertiary referral centre in Ireland. Asthma Control Test scores and data on hospitalisations, exacerbations, maintenance corticosteroid requirements, rescue bronchodilator use and peak expiratory flow rate (PEFR) were compared one year before and one year post treatment. Significant improvements were demonstrated in mean Asthma Control Test scores, from 8.9 to 14.7 (p = 0.036). Trends towards improvement were seen in mean hospitalisations (respective values for total in 12 month period 5.0, 0.9; p = 0.059) and PEFR (181.4 l/min, 280 l/min respectively; p = 0.059). These data support the use of bronchial thermoplasty in severe persistent asthma in the Irish population.

First bilateral lobar lung transplant in Ireland: advanced operative strategies in lung transplantation.

Lobar lung transplantation is an option that provides the possibility of transplantation of small size recipients with size-mismatch donor lungs by surgically reducing the size of donor lungs. We report our first experience of bilateral lobar lung transplantation of big donor lungs, in a small size urgently listed recipient, after size reduction. A 24 years old girl with end stage cystic fibrosis received the bilateral lobar lung transplant. She made very good recovery postoperatively and was discharged home two weeks following surgery.

The efficacy and safety of bronchial thermoplasty in severe persistent asthma on extended follow-up.

BACKGROUND: Asthma is a common condition and there remains a subset of patients who are poorly controlled on maximal therapy. Bronchial thermoplasty (BT) is a bronchoscopic therapy using radiofrequency energy to reduce airway smooth muscle, which has been shown to improve asthma control although further evidence regarding long-term efficacy and safety is required. AIM: We aimed to demonstrate safety and efficacy of BT on extended follow-up. Our initial experience with this group was previously reported in 2016, where patients were shown to have a significant improvement in asthma control test (ACT) scores 1-year post-treatment. DESIGN: We carried out a retrospective observational study of seven patients who underwent BT between 2012 and 2013 in an Irish severe asthma centre. The primary endpoint was change in ACT scores from baseline to present. METHODS: Seven patients underwent BT at a tertiary referral centre in Ireland. ACT scores and data on hospital admissions, exacerbations, maintenance corticosteroid requirements, rescue bronchodilator use and forced expiratory volume for 1 s (FEV1) prior to the procedure and on extended follow-up were collected. Mean follow-up was 49.42 months. RESULTS: A trend towards improvement was seen in median hospitalisations (respective values for median over 12 months 3, 1 P = 0.059) and ACT scores, from 9 to 13 (P = 0.249). Mean FEV1 was 1.68 l prior to treatment and 1.46 l 4 years post-treatment (P = 0.237). There was no mortality among the group. CONCLUSIONS: These data support the safety of BT and suggest extended efficacy.

Renal transplantation outcomes following heart and heart-lung transplantation.

BACKGROUND: Chronic kidney disease is a frequent complication following heart and combined heart-lung transplantation. The aim of this study was to analyse the outcome of a subsequent renal transplant in heart, lung and heart-lung transplantation recipients. METHODS: All heart, lung and heart-lung transplant recipients who received a subsequent renal transplant over a 27-year period in a national heart and lung transplant centre were included in this study. RESULTS: A total of 18 patients who had previously undergone heart (n = 6), lung (n = 7) and heart-lung (n = 5) transplantation received a renal transplant. The mean duration to development of end-stage kidney disease (ESKD) was 115 ± 45.9 months. The most common contributor to ESKD was calcineurin inhibitor nephrotoxicity. The 5-year patient survival and graft survival rates were 91.7 and 85.6%, respectively. The median creatinine level at the most recent follow-up was 123 µmol/L, IQR 90.8-147.5. CONCLUSIONS: The overall outcome of renal transplantation following previous non-renal solid organ transplantation is excellent considering the medical complexity and co-morbidities of this patient population. Renal transplantation represents an important treatment option for ESKD in non-renal solid organ transplant recipients.

The first 20 years of heart transplantation in Ireland.

BACKGROUND: The first Irish heart transplant was performed on the 10th of September 1985. Over the next 20 years, 229 transplants were performed in 228 recipients. AIMS: To evaluate the success of the first generation of cardiac transplantation in Ireland. METHODS: Analysis of clinical outcomes and survival statistics for patients undergoing heart transplantation in Ireland and comparison with international standards. RESULTS: There has been a steady improvement in transplant outcome over this time and survival figures for recipients between 2000 and 2004 show a hospital, 1-year and 5-year survival rate of 85.7%, 84.1% and 76.8% respectively. Thirty-eight of the 99 heart transplants performed between 1985 and 1994 are still alive more than 10 years later and the longest survivor is now 19 years post transplantation. CONCLUSIONS: The results compare favourably with international figures. Heart transplantation offers excellent longterm survival and quality of life but remains challenged by a shortage of suitable donor organs.

Osteosarcoma cytosol factor promotes parathyroid hormone stimulation of adenylate cyclase independent of GTP.

The adenylate cyclase (ATP pyrophosphate-lyase (cyclizing), EC 4.6.1.1)-stimulating factor from rat osteosarcoma cytosol was purified 600-fold by ion-exchange chromatography. The factor has an apparent Mr of 20000, is cold-labile, but retains activity at -20 degrees C in 10% glycerol. The factor enhanced parathyroid hormone stimulation of adenylate cyclase and restored hormone responsiveness to membranes washed with 0.5 M NaCl. These 'GTP-like' effects were not inhibited by 100 microM GDP-beta-S, which completely abolished the GTP enhancement of both basal and hormone-stimulated adenylate cyclase. Adenylate cyclase activity in the presence of the stimulating factor was linear with time, and showed hyperbolic dependence on factor concentration. The factor also linearized (in double reciprocal plots) the downward-concave Mg2+-dependence of adenylate cyclase, increasing the apparent affinity of the enzyme for Mg2+. The presence of the factor in two clonal osteosarcoma cell lines correlated with parathyroid hormone-stimulatable adenylate cyclase. Factor stimulation was absent while GTP stimulation was retained in the hormone-nonresponsive clone. Factor and hormone sensitivity were restored by in vivo passage. This factor thus may represent a guanyl nucleotide-independent path for cellular regulation of hormone response.

cAMP, not Ca2+/calmodulin, regulates the phosphorylation of acetylcholine receptor in Torpedo californica electroplax.

The regulation of the phosphorylation of the acetylcholine receptor in electroplax membranes from Torpedo californica and of purified acetylcholine receptor was investigated. The phosphorylation of the membrane-bound acetylcholine receptor was not stimulated by Ca2+/calmodulin, nor was it inhibited by EGTA, but it was stimulated by the catalytic subunit of cAMP-dependent protein kinase, and was blocked by the protein inhibitor of cAMP-dependent protein kinase. Purified acetylcholine receptor was not phosphorylated by Ca2+/calmodulin-dependent protein kinase activity in electroplax membranes, nor by partially purified Ca2+/calmodulin-dependent protein kinases from soluble or particulate fractions from the electroplax. Of the four acetylcholine receptor subunits, termed alpha, beta, gamma and delta, only the gamma- and delta-subunits were phosphorylated by the cAMP-dependent protein kinase (+ cAMP), or by its purified catalytic subunits.

Chronic dosing with aminoguanidine and novel advanced glycosylation end product-formation inhibitors ameliorates cross-linking of tail tendon collagen in STZ-induced diabetic rats.

Solubility of tail tendon collagen from normal, streptozotocin-induced diabetic Lewis rats, and diabetic animals treated with aminoguanidine and two novel advanced glycosylation end products (AGE)-formation inhibitors was investigated by limited pepsin digestion under acidic conditions. Assays were conducted using tail tendon collagen from Lewis rats obtained from two different vendors, Harlan and Charles River Laboratories. Collagen solubility was assessed by following the kinetics of pepsin digestion. The data revealed that the rate of digestion for diabetic animals is markedly slow relative to that of normals. More strikingly, the kinetics of the diabetic animals showed the feature of a lag in digestion regardless of the animal source. Experiments designed to optimize the difference in solubility between normal and diabetic animals demonstrated that Charles River animals exhibit a greater window of solubility than the Harlan animals. More importantly, a pronounced effect of aminoguanidine, an AGE-formation inhibitor, was observed in Charles River animals, but not in the Harlan animals, presumably because of the larger window of solubility between the normal and the diabetic animals in the former. These data indicated that the Charles River Lewis rats are an animal model that demonstrates greater efficacy in this assay. Analysis of in vivo screens designed to test efficacy of aminoguanidine and two novel AGE-formation inhibitors, ALT 462 and ALT 486, demonstrated that monitoring an in vivo dose response is highly dependent on the enzyme concentration as well as the time of digestion, and that 1.5 h of digestion and 10 microg/ml pepsin (5 pg pepsin/mg collagen) appeared optimal. Under these conditions, a 29% normalization of solubility was observed with aminoguanidine at 100 mg/kg body wt, whereas a similar normalization was observed at 10 mg/kg body wt for both ALT 462 and ALT 486. Thus, on a molar basis, ALT 462 and ALT 486 are at least 20 times more potent than aminoguanidine. This is the first demonstration of dose-dependent efficacy for AGE-formation inhibitors in animal models, and as such, this assay provides a method with which to assess the in vivo efficacy of other such inhibitors.

Heart transplant candidates: factors influencing waiting list mortality.

Cardiac transplantation is a successful treatment for end-stage heart disease. However the number of potential candidates is significantly greater then number of suitable organ donors. We reviewed the characteristics of new transplant candidates presenting for assessment for cardiac transplantation to the Irish Heart & Lung Transplant programme over a one year period. Of 44 patients referred for assessment, 24 (54.5%) were listed for cardiac transplantation. Six have died while awaiting transplantation, seven have been transplanted and eleven remain on the active transplant list. The six month survival rate on the transplant waiting list is 74%. Although the Irish system of organ donation has traditionally provided high organ donation rates in comparison with other countries, the demand for suitable heart donors exceeds supply. Newer methods of promoting and facilitating organ donation may prove beneficial in improving the number of donations and addressing the long waiting time for cardiac transplantation.

The effect of 1,25-dihydroxyvitamin D3 on the cytoskeleton of rat calvaria and rat osteosarcoma (ROS 17/2.8) osteoblastic cells.

1,25-dihydroxyvitamin D3 produces pronounced shape changes in fetal rat calvaria and osteosarcoma-derived (ROS 17/2.8) osteoblastic cells, characterized by retracting processes and cell rounding followed by aggregation of cells. The 1,25(OH)2D3 effect on ROS 17/2.8 morphology was determined morphometrically on scanning electron micrographs. The hormone effect was found to be dose dependent between 10(-12) and 10(-9) M. The shape changes appeared 12 h after hormone (10(-10) M) addition and were present in 80% of the ROS 17/2.8 cells and in 50% of the calvaria cells at 72 h. Cycloheximide at 1 microM, inhibited the hormone-dependent change in morphology. The 1,25(OH)2D3 effects were partially mimicked by 10(-8) M 25(OH)D3 but not by 10(-10) M 25(OH)D3 or 10(-11)-10(-8) M 24,25(OH)2D3. 1,25-dihydroxyvitamin D3 also increased cell proliferation twofold at 14 days in serum-free medium. 1,25(OH)2D3 treatment produced changes in microfilament organization, visualized with rhodamine-conjugated phalloidin. Microfilaments were localized at the terminal attachment points and in the perinuclear region, and few if any, were seen in the retracting processes themselves. Estimation of cytoskeletal actin and myosin by gel electrophoresis of Triton X-100 nonextractable proteins showed a 30% reduction in these proteins in the hormone-treated cells. Microtubules visualized by indirect immunofluorescence showed no major changes in organization. Both colchicine and cytochalasin D altered the hormone-induced shape change, suggesting that both microfilaments and microtubules were required for this process. Thus, 1,25(OH)2D3 had pronounced effects on cell shape in osteoblastic cells, probably via de novo protein synthesis. These changes lead to rearrangement of the cytoskeleton, primarily the microfilaments.

The effect of dexamethasone on parathyroid hormone stimulation of adenylate cyclase in ROS 17/2.8 cells.

Treatment of ROS 17/2.8 osteosarcoma-derived cells with dexamethasone potentiates the PTH stimulation of adenylate cyclase in these cells, yielding a detectable response to as little as 10 pM PTH. Isoproterenol stimulation was also enhanced. The dexamethasone effect is first apparent at 12 h and increases with time of treatment. The apparent EC50 for dexamethasone is 3 nM. Hydrocortisone and corticosterone act similarly to dexamethasone, but require 30-fold higher concentrations. Dexamethasone treatment produces no change in high affinity phosphodiesterase activity. Glucocorticoid-potentiating effects are much more pronounced in whole cells than in broken cells and do not influence forskolin stimulation. Particulate fractions of dexamethasone-treated cells have higher adenylate cyclase specific activity, but are stimulated by guanyl-5'-yl imidodiphosphate to the same extent as control cells. These findings suggest that the glucocorticoids potentiate hormone responsiveness through promotion of hormone receptor-adenylate cyclase coupling by a mechanism dependent on cellular integrity.

Preemptive treatment for the prevention of cytomegalovirus disease: in lung and heart transplant recipients.

BACKGROUND: Rapid quantifiable diagnostic techniques for the diagnosis of cytomegalovirus (CMV) infection may predict patients at risk of CMV pneumonitis and allow preemptive antiviral treatment. METHODS: Using CMV antigenemia as a prospective surveillance technique for CMV infection, we compared the outcome of preemptive treatment (PT) with ganciclovir, 10 mg/kg/day for 21 days directed by "high levels" of CMV antigenemia (PT group, n= 19), with the outcome in a group of historical controls (n=18) treated with ganciclovir when CMV illness occurred. Greater than 50 antigen-positive cells per 2 x 10(5) polymorphonuclear leukocytes was considered to be high-level antigenemia. RESULTS: Nine of the 18 controls developed high-level CMV antigenemia at a median of 33 days (range: 13-65 days) and 5 of the 9 developed CMV disease. Ten of the 19 PT group had high levels of CMV antigenemia detected at a median of 47 days (range: 20-63 days) and were given ganciclovir; none developed CMV disease. There was a significantly lower incidence of CMV disease in the PT group in comparison to controls (0 of 19 vs. 5 of 18: P=0.019). CONCLUSION: We have reduced the incidence of CMV disease using preemptive treatment, and because of a 100% negative predictive value, we omitted unnecessary antiviral prophylaxis for many at-risk patients.

Pulmonary diffusion abnormalities in heart transplant recipients. Relationship to cytomegalovirus infection.

Lung function of patients with heart failure is characterized by a variety of changes proposed as being due to passive congestion, secondary pulmonary fibrosis, and/or recurrent pulmonary emboli. A diffusion impairment thought to be due to cyclosporine has also been noted in patients following heart transplantation. Similar changes of unclear origin have been observed in renal transplant recipients. The objective of this study was to determine the extent to which lung function changes are reversible by cardiac transplantation and relate changes to the status of the recipients lung in the presence of possible vascular, iatrogenic, immune, or infectious injury. We analyzed the data of 22 patients who underwent lung function testing before and after heart transplantation and correlated changes to hemodynamic change, episodes of rejection, concentration of cyclosporine, and cytomegalovirus infection. Despite excellent graft function, the carbon monoxide transfer factor deteriorated to a mean of 57 percent of predicted postoperatively. The fall in diffusion factor did not correlate with episodes of cardiac rejection, cyclosporine levels, or hemodynamic status. In those patients who had serologic evidence of cytomegalovirus infection, the reduction in transfer factor was greater compared to those without infection despite a normal chest radiograph. The effects of cardiopulmonary bypass were unlikely to have been responsible for the abnormalities as lung function was assessed at a mean of 14 months after surgery. In heart transplant recipients, a change in diffusion capacity may represent an additional marker for cytomegalovirus infection and reflect infectious/immune injury late following surgery.

Idiopathic pulmonary fibrosis and cyclosporine: a lesson from single-lung transplantation.

Idiopathic pulmonary fibrosis (IPF) has a poor prognosis and therapeutic options are limited with a 5-year survival of less than 50%. This report includes a case of histologically confirmed IPF in a patient whose native lung showed objective improvement as measured by high-resolution CT while he was receiving cyclosporine-based immunosuppressive therapy after single-lung transplantation.

Pulmonary Langerhans' cell histiocytosis: radiologic resolution following smoking cessation.

We describe two patients with histologically proven pulmonary Langerhans' cell histiocytosis in whom radiologic improvement occurred following smoking cessation. The patients had 23- and 25-pack-year smoking histories, respectively. High-resolution CT revealed multiple small nodules, located predominantly in the upper and middle lung fields. There was a close temporal relationship between smoking cessation and radiologic improvement.