Screening Echocardiography Identifies Risk Factors for Pulmonary Hypertension at Discharge in Premature Infants with Bronchopulmonary Dysplasia.

HYPOTHESIS: Premature infants with bronchopulmonary dysplasia (BPD) are at increased risk of secondary pulmonary hypertension (BPD-PH). Prior studies yielded mixed results on the utility of echocardiographic screening at 36 weeks post-menstrual age (PMA). We present our experience using echocardiographic screening at the time of BPD diagnosis to identify infants at highest risk of BPD-PH at discharge. MATERIALS AND METHODS: Retrospective cohort analysis of clinical/ demographic data and screening echocardiograms in patients with BPD. Discharge echocardiograms identified infants with or without BPD-PH at discharge. 36 weeks PMA screening echocardiograms and clinical data were then reviewed to identify which factors were associated with increased odds of BPD-PH at discharge. Associations between echocardiographic findings were evaluated with 2- and 3-variable models to predict increased risk of BPD-PH at discharge. RESULTS: In our cohort of 64 infants with severe BPD, BPD-PH was present in 22/64 (34%) infants at discharge. There were no clinical differences at time of 36 weeks PMA screening evaluation (mean PMA 36.6 ± 2.9 weeks). PH at screening was poorly predictive of PH at discharge as PH at screening resolved in 49% of patients. However, having an ASD, RV dilation, hypertrophy, or reduced function on screening, especially in combination, were associated with BPD-PH at discharge. CONCLUSION: In our cohort of premature infants with BPD, 36 weeks PMA screening echocardiogram identified patients at increased risk for BPD-PH at discharge when ASD, RVH, or impaired RV function were present. Larger prospective studies are indicated to validate these findings.

Implications of paper vs stainless steel biological indicator substrates for formaldehyde gas decontamination.

AIMS: This study was undertaken to determine the effectiveness of biological indicators currently being employed during formaldehyde decontamination. Data suggest that detectable amounts of formaldehyde are absorbed into the paper strips contained in currently used biological indicators. Absorbed formaldehyde has the potential to inhibit the growth of indicator spores, thus leading to false negative results. Indicators composed of either stainless steel carriers or paper strips were investigated to determine whether stainless steel carriers can be used as an alternative to paper strip indicators. METHODS AND RESULTS: Biological indicators were exposed to formaldehyde gas and were tested for the presence of formaldehyde and any possible inhibition of spore growth. Absorbed formaldehyde was detected in the paper strip carriers while no formaldehyde was detected from any of the stainless steel carriers. Exposed paper strips were found to inhibit growth of up to 1 × 10(6) spores while the stainless steel carriers did not inhibit the growth of spores. CONCLUSIONS: During decontamination, biological indicators composed of paper spore strips absorb formaldehyde and inhibit growth of any surviving spores. Stainless steel carriers do not absorb formaldehyde and are an ideal alternative substrate for biological indicators. SIGNIFICANCE AND IMPACT OF THE STUDY: The popular paper strip biological indicator can lead to false negative results during decontamination and is unsuitable for validating formaldehyde decontamination.

Endobronchial stenting in the management of large airway pathology.

Endobronchial interventions including the deployment of endobronchial stents have a clear role in the management of central airway problems. The use of endobronchial stents has rapidly increased since the first airway stent was developed in the 1960s and with the subsequent manufacture of improved silicone and metallic stents. They provide effective relief for symptoms of intrinsic and extrinsic airway obstruction secondary to a wide range of pathologies including lung cancer, lymphoma, thyroid carcinoma and benign disease such as tracheal strictures and tracheobronchomalacia. Endobronchial stents can also seal defects within the airway including malignant broncho-oesophageal fistulae and posterior wall tracheal tears. They can be placed safely under conscious sedation at flexible bronchoscopy or under general anaesthetic at rigid bronchoscopy. Rigid bronchoscopy under general anaesthesia provided by a multidisciplinary team is safe with few contraindications. Complications of endobronchial stents include infection, granulation tissue formation and metallic stent fracture sometimes requiring removal, although serious life-threatening complications are very rare. Increasing numbers of patients are being referred to specialist centres for airway intervention. This article reviews the history of endobronchial stents, the different stents available, and the indications, outcomes and complications involved in deploying endobronchial stents.

Identification of a 60-kilodalton stress-related protein, p60, which interacts with hsp90 and hsp70.

Immunoaffinity purification of hsp90 from chick oviduct cytosol reveals two major proteins, hsp70 and a 60-kDa protein (p60), copurifying with hsp90. A similar result is obtained when hsp90 is immunoaffinity purified from chick liver and brain cytosols, avian fibroblasts, and rabbit reticulocyte lysate. This p60 is the same protein previously identified in certain assembly complexes of chick progesterone receptor generated in a cell-free reconstitution system. Tryptic and cyanogen bromide peptide fragments were generated from gel-purified p60, and partial N-terminal sequences were determined from eight peptides. The sequences show a striking similarity to the sequence of a 63-kDa human protein (IEF SSP 3521) whose abundance is increased in MRC-5 fibroblasts following simian virus 40 transformation. A monoclonal antibody was prepared against avian p60; Western immunoblot analysis showed that p60 was present in each of eight chick tissues examined and in each of the human, rat, rabbit, and Xenopus tissues tested. Immunoaffinity purifications from both chick oviduct cytosol and rabbit reticulocyte lysate using anti-p60 and anti-hsp70 monoclonal antibodies confirm that there is a relatively abundant complex in these extracts containing hsp90, hsp70, and p60. This complex appears to comprise an important functional unit in the assembly of progesterone receptor complexes. However, judging from the abundance and widespread occurrence of this multiprotein complex, hsp90, hsp70, and p60 probably function interactively in other systems as well.

ABRF ESRG 2005 study: identification of seven modified amino acids by Edman sequencing.

Identification of modified amino acids can be a challenging part for Edman degradation sequence analysis, largely because they are not included among the commonly used phenylthiohydantion amino acid standards. Yet many can have unique retention times and can be assigned by an experienced researcher or through the use of a guide showing their typical chromatography characteristics. The Edman Sequencing Research Group (ESRG) 2005 study is a continuation of the 2004 study, in which the participating laboratories were provided a synthetic peptide and asked to identify the modified amino acids present in the sequence. The study sample provided an opportunity to sequence a peptide containing a variety of modified amino acids and note their retention times relative to the common amino acids. It also allowed the ESRG to compile the chromatographic properties and intensities from multiple instruments and tabulate an average elution position for these modified amino acids on commonly used instruments. Participating laboratories were given 2000 pmoles of a synthetic peptide, 18 amino acids long, containing the following modified amino acids: dimethyl- and trimethyl-lysine, 3-methyl-histidine, N-carbamyl-lysine, cystine, N-methyl-alanine, and isoaspartic acid. The modified amino acids were interspersed with standard amino acids to help in the assessment of initial and repetitive yields. In addition to filling in an assignment sheet, which included retention times and peak areas, participants were asked to provide specific details about the parameters used for the sequencing run. References for some of the modified amino acid elution characteristics were provided and the participants had the option of viewing a list of the modified amino acids present in the peptide at the ESRG Web site. The ABRF ESRG 2005 sample is the seventeenth in a series of studies designed to aid laboratories in evaluating their abilities to obtain and interpret amino acid sequence data.

Tracheal stenosis diagnosed on pulmonary ventilation/perfusion scan.

A 68-year-old woman, who had undergone coronary artery bypass surgery 5 months previously, was presented with cough, breathlessness and an elevated D-dimer. She was initially thought to have suffered a pulmonary embolus. A ventilation/perfusion scan demonstrated tracheal stenosis, which required dilation and endobronchial stent deployment. Tracheal stenosis is a well-recognised complication of endotracheal intubation; however, the onset of symptoms is often insidious and the diagnosis delayed.

Androgens affect the processing of secretory protein precursors in the guinea pig seminal vesicle. II. Identification of conserved sites for protein processing.

The guinea pig seminal vesicle epithelium is an androgen-dependent tissue that synthesizes and secretes four major secretory proteins (SVP-1, SVP-2, SVP-3, and SVP-4). Sequencing of near full-length cDNA clones corresponding to the two most abundant mRNAs produced by the seminal vesicle reveals that all four secretory proteins are cleaved from two secretory protein precursors. Amino acid sequences from purified SVP-2 match the central region of the predicted amino acid sequences from the smaller cDNA clone, GP2 (581 nucleotides). Similar analysis demonstrates that the predicted amino acid sequence from the longer cDNA clone, GP1 (1368 nucleotides), codes for the related proteins SVP-3 and SVP-4 as well as SVP-1. The 43.2 kilodalton polyprotein precursor coded by GP1 contains two different sets of 24 amino acid tandemly repeated sequences. The two secretory protein precursors have extensive regions of peptide sequence homology, particularly in regions where protein processing must occur to produce the mature secretory proteins. Analysis of the predicted secondary structure of the two precursor polypeptides revealed a strong correlation between structural features and sites of protein processing.

Use of tracheal stenting in the palliation of anaplastic thyroid carcinoma: tertiary centre experience.

BACKGROUND: Anaplastic thyroid carcinoma is rare but carries a poor prognosis. Anaplastic thyroid carcinoma leads to tracheal compression, airway compromise and eventually death. Airway compromise, a particularly distressing symptom, can be palliated with tracheal stenting. METHOD: A retrospective case note analysis was conducted of patients diagnosed with anaplastic thyroid carcinoma between July 2003 and July 2013. RESULTS: Twelve patients with anaplastic thyroid carcinoma were identified. Four patients underwent palliative tracheal stenting. Three patients had no dyspnoea at the time of stenting. Two stented patients subsequently developed dyspnoea secondary to stent migration; this was managed successfully with stent exchange. The other stented patient remained asymptomatic with regards to dyspnoea. All non-stented patients died with or from airway compromise. CONCLUSION: Tracheal stenting is a relatively safe and effective method for palliation of distressing airway symptoms in patients with anaplastic thyroid carcinoma. Early prophylactic tracheal stenting in anaplastic thyroid carcinoma may be an effective option to prevent development of airway compromise as the disease progresses.

The antigenic structure of the human glycoprotein hormone alpha-subunit: II. Cross-species comparisons.

Eight monoclonal antibodies, specific for the glycoprotein hormone alpha-subunit, were raised against human free alpha-subunit, human FSH, or human CG. All of these antihuman monoclonal antibodies were tested for cross-reactivity with alpha-subunits derived from bovine, porcine, equine, bull frog, sea turtle, turkey, and ostrich glycoprotein hormones. All showed cross-reactivity with affinities ranging from 10(-4) to 10(-8) depending upon the antibody and the species of alpha-subunit. Cyanogen bromide fragments of bovine and equine alpha, when tested with selected antibodies indicated that antigenic determinants could be localized in two regions: alpha 9-33 and alpha 76-92. Comparison of amino acid sequences, and relative potencies, suggest that major antigenic determinants involve residues 21, 22, and 23 (F-F-S in human alpha) and 76-85 (G-G-F-K-V-E-N-H-T-A in human alpha). As part of this study the N-terminal amino acid sequences of bull frog, sea turtle, turkey, and ostrich alpha-subunits were determined and reported for the first time.

Hemoglobin Old Dominion/Burton-upon-Trent, beta 143 (H21) His-->Tyr, codon 143 CAC-->TAC--a variant with altered oxygen affinity that compromises measurement of glycated hemoglobin in diabetes mellitus: structure, function, and DNA sequence.

OBJECTIVE: To determine the nature and characteristics of a unique hemoglobin variant that causes a spurious increase in glycated hemoglobin (HbA1c). MATERIAL AND METHODS: Blood specimens from four unrelated persons with this hemoglobin variant were examined by conventional laboratory methods, including electrophoresis, high-performance ion-exchange chromatography, and isoelectric focusing; by amino acid sequence analysis, polymerase chain reaction-based DNA sequence analysis, and electrospray ionization mass spectrometry, to establish the molecular structure; and by studies of oxygen affinity under varied conditions, to define the functional characteristics of the hemoglobin variant. RESULTS: The unique hemoglobin variant observed in these four cases is due to the mutation CAC-->TAC, at beta-globin gene codon 143, corresponding to beta 143 (H21) His-->Tyr. This amino acid substitution affects an important 2,3-diphosphoglycerate binding site and slightly increases the oxygen affinity of the hemoglobin variant. CONCLUSION: A hitherto unrecognized hemoglobin variant, encountered in four unrelated persons of Irish or Scots-Irish ancestry, hemoglobin Old Dominion/Burton-upon-Trent, beta 143 (H21) His-->Tyr, has now been characterized at the molecular, structural, and functional levels. Although it is associated with a slight increase in oxygen affinity, it is without hematologic effect, and its only clinical significance is that it coelutes with HbA1c on ion-exchange chromatography and thereby causes a spurious increase in HbA1c and compromises the use of this analyte to monitor the treatment of diabetes mellitus.

Nocardia asteroides abscess after heart transplantation.

We describe a patient who developed a primary, thigh adductor-muscle abscess caused by Nocardia asteroides 3 years after orthotopic cardiac transplantation. Nocardia was diagnosed by microbiologic culture and responded fully to a prolonged course of cotrimoxazole. The patient remains free of local or systemic disease at 2 years follow-up.

Bacterial endocarditis: a rare complication following orthotopic cardiac transplantation.

We describe a 46-year-old man who developed infective endocarditis, meningitis, sternal abscess, and infective cerebral emboli after cardiac transplantation. Staphylococcus aureus was the infective organism. We successfully managed the patient with flucloxacillin and fusidic acid to treat infection, and with prostacyclin for systemic embolization.

Spinal osteomyelitis and diskitis: a rare complication following orthotopic heart transplantation.

We describe a 55-year-old man who developed spinal osteomyelitis and diskitis 14 months after orthotopic heart transplantation. The infective organism was Staphylococcus aureus and the patient was successfully treated with flucloxacillin and fusidic acid.

Transbronchial biopsy in heart and lung transplantation: clinicopathologic correlations.

BACKGROUND AND METHODS: We reviewed and correlated the histologic and clinical records for the 1027 transbronchial biopsies performed, as clinically indicated, in 313 heart and lung transplant recipients in the Harefield Transplant Unit from 1988 through 1991. Three pieces of lower lobe or radiologically abnormal lung were routinely sent for histologic diagnosis. Clinical diagnoses of rejection and infection were based on symptomatologic, radiologic, and bacteriologic findings and response to appropriate therapy. Standard histopathologic technology and diagnostic criteria were used, including the Working Formulation for the standardization of nomenclature in the diagnosis of heart and lung rejection grading. RESULTS: Rejection was the most common finding (22.2%) and showed good clinicopathologic correlation. With unequivocal histologic features of rejection (Working Formulation grade A1 or above), specificity (clinical agreement with biopsy diagnosis) was 93.1% and sensitivity (clinical rejection confirmed by transbronchial biopsy) was 61%. Sensitivity increased to 77% if unsatisfactory specimens were excluded. Possible/probable rejection only was reported in 83 specimens; there were technically unsatisfactory, showed only minimal perivascular infiltrates, or had infiltrates limited to one vessel; 71% of these did have clinical rejection. Infection, excluding opportunistic, was reported in 18.5% of biopsy specimens; specificity was 70.5% and sensitivity 51.3% (both rising by 9%), with unsatisfactory specimens excluded. Histologic features of both rejection and infection were seen in 47 transbronchial biopsy specimens (4.7%). Where both components appeared definite specificity was 66.7%, but where either had been doubtful the clinical diagnosis was most often rejection. Sensitivity was also 66.7%. Cytomegalovirus inclusions were identified in 12.1% of biopsy specimens, with specificity of 91% and sensitivity of 83.5%. Sensitivity (88%) and specificity (100%) were both high for the 17 cases with pneumocystis infections. Sensitivity for the 25 transbronchial biopsy specimens from fungal infections was only 20%. Sensitivity was also poor (27.7%) in obliterative bronchiolitis, although specificity was 75%. Almost a third of transbronchial biopsy specimens from patients with obliterative bronchiolitis were unsatisfactory. Pneumonitis was the only change noted in 68 biopsy specimens. Most correlated with clinical status, but 26.5% were from patients with active rejection. Nonspecific changes or no significant pathologic condition was seen in 278 transbronchial biopsy specimens; over a third of these were from patients with clinical rejection (17.7%) or infection (18%) and 6.5% were from obliterative bronchiolitis cases. Excluding 78 technically unsatisfactory specimens reduced the proportion of false negative findings in rejection and infection by 6% and 4%, respectively. CONCLUSIONS: We found that transbronchial biopsies consisting of three adequate pieces of lung parenchyma correlated well with clinical rejections and infections other than fungal but was of limited value in confirming a diagnosis of obliterative bronchiolitis or fungal infection.

Recurrence of hepatitis B after single lung transplantation.

This study describes a patient who developed decompensated liver disease secondary to reactivation of hepatitis B infection 20 months after single lung transplantation following augmentation of immunosuppression to treat allograft rejection. Discussion focuses on the virologic and management issues of this case and reviews the approach taken when considering patients with chronic hepatitis B infection for lung transplantation.

Total lymphoid irradiation as rescue therapy after heart transplantation.

BACKGROUND: Allograft dysfunction develops in a proportion of heart transplant recipients without significant cellular infiltrate in endomyocardial biopsies and with normal coronary arteries at angiography. The mechanisms responsible for this presentation are unclear, and the prognosis is poor. We report encouraging experience with total lymphoid irradiation given in addition to cyclosporine A, cyclophosphamide, and prednisolone therapy in three heart transplant recipients with poor graft function with normal endomyocardial biopsies and coronary angiography. METHODS: Three patients who had severe allograft dysfunction after orthotopic heart transplantation, with normal endomyocardial biopsies and coronary angiography, were successfully treated with total lymphoid irradiation. Biventricular failure developed in each patient despite immunosuppression with cyclosporine A, azathiaprine, oral prednisolone, cyclophosphamide, and intravenous methylprednisolone therapy. Total lymphoid irradiation was given with standard mantle and inverted y fields over 10 treatments to achieve a cumulative dose of 8 Gy. RESULTS: Each patient had a significant improvement in clinical response and in ventricular performance after total lymphoid irradiation, which was well tolerated in each case. The patients remain well at 8, 9, and 12 months after completion of treatment. CONCLUSIONS: Total lymphoid irradiation should be considered as adjunct therapy to conventional immunosuppression for heart transplant recipients with poor graft function in the absence of cellular rejection or coronary artery disease.

Wrapping the anastomosis with omentum or an internal mammary artery pedicle does not improve bronchial healing after single lung transplantation: results of a randomized clinical trial.

Between May 1989 and March 1990, 36 patients undergoing a first single lung transplantation were randomized to three groups. In the omentum group the bronchial anastomosis was wrapped with an omental pedicle. In the internal mammary artery group, the anastomosis was wrapped in a pedicle of tissue surrounding the internal mammary artery. In the no wrap group, no attempt was made to revascularize the anastomosis. No significant differences were found in the indications for transplantation, recipient age, organ ischemic time, or preoperative steroid use in the three groups. There were two early deaths: one in the omentum group as a result of infection and one in the internal mammary artery group as a result of multiorgan failure. During a mean follow-up period of 21 months (range 9 to 32), there were two additional deaths in the no wrap group and four in the omentum group, one of which involved an anastomotic complication. Actuarial survival at 1 year was 75%, 92%, and 80% in the omentum, internal mammary artery, and no wrap groups, respectively (p = 0.25). Granulation tissue at the site of the anastomosis requiring cryotherapy or bronchial dilatation occurred in two patients in the omentum group, three in the internal mammary artery group, and three in the no wrap group. Bronchial stents were required in one patient in the omentum group and one in the internal mammary artery group. Actuarial survival free of anastomotic complications was similar in the three groups. The incidence of bronchial anastomotic complications after single lung transplantation is not affected by wrapping the anastomosis with either omentum or an internal mammary artery pedicle.

Absence of bradycardic response to apnea and hypoxia in heart transplant recipients with obstructive sleep apnea.

In patients with obstructive sleep apnea, the vagal stimulation caused by inspiration against the upper airway obstruction results in sinus bradycardia during the apnea followed by a reflex tachycardia at apnea termination. We report on five heart transplant recipients with obstructive sleep apnea who demonstrated no change in baseline heart rate in spite of marked hemoglobin oxygen desaturation, presumably on account of parasympathetic denervation of the allograft. Heart transplant recipients with obstructive sleep apnea may be at an increased risk of development of potentially fatal ventricular arrhythmias if the allograft is unable to respond appropriately to hypoxia. Should cardiac parasympathetic reinnervation occur, prospective polysomnography may be a marker for this process in these patients.

Regional variations in endothelin-1 and its receptor subtypes in human coronary vasculature: pathophysiological implications in coronary disease.

Endothelin-1 is a potent vasoconstrictor peptide and mitogen for vascular smooth muscle cells. Increased plasma or tissue levels of endothelin-1 have been described after myocardial infarction and in atherosclerosis, suggesting that this peptide may play a pathophysiological role in various coronary syndromes. Here, we have studied regional variations in ET-1 and its receptors in control and atherosclerotic human coronary vasculature using standard immunohistochemistry and in vitro autoradiography. ET-1 immunoreactivity was associated with luminal endothelial cells and smooth muscle cells at regions of atherosclerosis. ET(A) receptors were present on smooth muscle cells of coronary arteries and on cardiac myocytes. Medial ET(B) receptor binding at the proximal region of coronary arteries was weak, but increased significantly towards distal regions of this vessel (p<0.005 in control and p<0.0005 in ischaemic heart disease). Microvascular endothelial cells in the adventitia of coronary arteries, myocardial microvessels and the endocardial endothelium expressed the ET(B) receptor exclusively. The receptor variations revealed in this study provide supporting evidence that ET-1 is associated with (1) vascular smooth muscle and endothelial cell proliferation, including areas of intimal hyperplasia and regions of neovascularization (2) increased ET-1-induced reactivity of distal portions of the human coronary artery, (3) ET-1-mediated constriction of myocardial microvessels. These results provide new insights into different potential roles for this peptide in healthy and diseased human coronary vasculature.

Myocyte nuclear area as a measure of left ventricular hypertrophy in transplant patients.

Transplanted hearts have been reported to increase in size/weight in the first few months after transplant and to remain stable thereafter. An indirect way of assessing the changes in heart weight is through the changes in the area of the myocyte nucleus (MNA). We studied 20 patients who had undergone orthotopic heart transplantation more than 12 months previously; 10 had become hypertensive, and the remaining 10 were normotensive. Myocardial biopsies taken the first week after transplant and 6, 12, 24, and 52 weeks after transplant were assessed. Myocyte nuclear area was measured in 200 myocytes/biopsy with an image analyzer. Individual measurements showed a wide variation in MNA, with significant overlaps among the different biopsies. Assessment of MNA at one year showed increased MNA in 4 10 patients in the hypertensive group and 5 10 in the normotensive group. The remaining patients showed either no statistically significant changes in MNA or a significant (p < 0.0001) decrease in MNA. The presence of systemic hypertension was not a predictive factor for significant hypertrophy and, in some cases, not even for hypertrophy itself. We conclude that although there is often an increase in MNA of the transplanted heart at one year posttransplant, this increase is not systematic, and isolated morphometric results should be viewed cautiously.