Retrospective Analysis of the First Collection versus the Second Collection in Severe Oligo-asthenoteratozoospermia Cases in Self-Intracytoplasmic Sperm Injection Patients

Background:

It is well established that high-quality semen can lead to an improved fertilisation rate. Ejaculatory abstinence (EA) certainly can influence sperm quality such as volume, count, motility and morphology. However, very few studies have addressed the influence of EA on intracytoplasmic sperm injection (ICSI) outcome and especially in males with severe oligo-asthenoteratozoospermia (OAT) syndrome.

Aim:

This study was undertaken with the purpose of evaluating the advantage of shorter abstinence period (1-h sequential ejaculation) in males with severe OAT syndrome on total usable embryo rate and thereby emphasising the potential application of consecutive ejaculate.

Study Setting and Design:

This retrospective cohort study consisted of all the infertile couples undergoing ICSI cycle with the indicated seminal characteristics who had consulted the tertiary care hospital between January 2021 and July 2021.

Materials & Methods:

All couples in the study had idiopathic male infertility. Retrospectively, two groups were analysed, i.e., Group A with 56 subjects in which first semen sample was used for ICSI cycle and another Group B with 41 subjects in which second semen sample collected within a shorter abstinence period of 1 h was used.

Statistical Analysis:

The data were descriptively analysed using GraphPad Prism (vs. 9.2). Unpaired t-test and analysis of variance test were used to determine the significance. P < 0.05 was considered statistically significant.

Results:

The age of female subjects in Group A was 29.9 ± 3.5 years while it was 29.4 ± 3.4 years in Group B. Similarly, the age of male subjects was 32.2 ± 3.6 years and 31.9 ± 4.1 years in Group A and Group B, respectively, with no statistical differences in any gender between the groups (P > 0.05). Apart from initial progressive motility (P = 0.004), none of the parameters such as total volume, total sperm count and morphology were significantly different (P > 0.05) between Group A and samples of Group B. Similarly, parameters such as volume (P = 0.006) and post-wash motility (P < 0.001) were significantly different between Group A and samples of Group B. However, there was no significant difference in sperm count and morphology (P > 0.05). Grade 1 embryos on day 3 were 345 (62.8%) in Group A and 170 (54.3%) in Group B. Overall, the total usable embryos in Group A and Group B were 222 (40.4%) and 148 (47.3%), respectively (P > 0.05).

Conclusion:

With regard to compromised sperm parameters, our findings do suggest that the second ejaculate is quite relevant to ‘in vitro’ reproductive treatments and a simple request for a second consecutive ejaculate (shorter abstinence period of 1 h) could provide the same results in terms of fertilisation. We observed the increased chances of usable embryos in the second ejaculate group.

Abstract 1750: Combination of ZEN-3694 with CDK4/6 inhibitors reverses resistance in ER-positive breast cancer

CDK4/6 inhibitors have been shown to significantly prolong progression-free survival in patients with advanced hormone receptor (HR)-positive, HER2-negative breast cancer. In spite of the great successes with the currents lines of therapies, the patients still acquire resistance over time and, the development of additional novel therapeutic strategies is needed.

The bromodomain and extra-terminal domain (BET) proteins are key epigenetic regulators that interact with acetylated lysine (AcLys) residues of histones or transcription factors, leading to the regulation of gene transcription. BET proteins have also been shown to be directly involved in the transcription of the estrogen receptor (ER) mRNA as well as cell cycle and therefore, BET inhibitors can potentially offer new strategies in the treatment of CDK4/6i- resistant and endocrine resistant ER+ breast cancer.

ZEN-3694 is an orally bioavailable small molecule inhibitor of BET proteins currently being evaluated in Phase 1/2 clinical trials in metastatic castration-resistant prostate cancer (NCT02711956) and triple negative breast cancer (NCT03901469). We have shown previously that ZEN-3694 inhibits proliferation and induces apoptosis in ER+ cell lines. To assess the effects of ZEN-3694 in the combination with CDK4/6 inhibitors as a potential therapy in a CDK4/6i resistant population, we have developed a panel of ER+ cell lines resistant to palbociclib or abemaciclib by continuous stepwise exposure to increasing concentrations of CDK4/6 inhibitors. These cell lines have demonstrated cross-resistance to all three CDK4/6 inhibitors. Here, we describe that the combination treatment of ZEN-3694 with CDK4/6 inhibitors potently inhibits proliferation and induces apoptosis in all CDK4/6i resistant cell lines. The resistance to both palbociclib and abemaciclib was associated with the strong upregulation of CDK6 and CCND1protein levels in MCF7 which is consistent with their clinical mechanism of resistance. ZEN-3694 showed efficacy in all CDK4/6i-resistant models leading to downregulation of ER and CDK6 protein levels. Furthermore, our RNAseq data revealed several potential pathways involved in CDK4/6i resistance, including upregulation of cell cycle pathway and decrease of interferon signaling and demonstrated that the mechanisms of resistance to abemaciclib and palbociclib are similar but not identical. Additionally, we elucidated the mechanism of action of ZEN-3694 and in combinations with CDK4/6 inhibitors alleviating these resistance mechanisms. The pathway analysis demonstrated that the combination of ZEN-3694 with CDK4/6 inhibitors led to the strong downregulation of multiple pathways including cell cycle regulation, signaling by Rho family GTPases, STAT3, IL6 and other pathways. We conclude that ZEN-3694 has therapeutic potential in a combination with CDK4/6 inhibitors in ER+ breast cancer patients that developed resistance to endocrine therapies and/or CDK4/6 inhibitors.

Citation Format: Olesya A. Kharenko, Reena G. Patel, Cyrus Calosing, Edward H. van der Horst. Combination of ZEN-3694 with CDK4/6 inhibitors reverses resistance in ER-positive breast cancer [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 1750.

Abstract 1282: Overcoming resistance to inhibitors of CDK4/6 and BET in estrogen receptor-positive breast cancer

Three inhibitors of CDK4/6 kinases have been recently approved for use in combination with endocrine therapy. These inhibitors considerably increase the progression-free survival of patients with advanced Estrogen receptor (ER)-positive breast cancer in first-line treatment. As the resistance to CDK4/6 inhibitors is currently a major problem faced in pre-clinical and clinical drug development, the identification of novel treatment combinations and predictive markers is of high importance. BET proteins, specifically BRD2/4, have important roles in cell cycle regulation and proliferation. Thus, BET inhibitors (BETi)have the potential to overcome some pathways of resistance, especially for those mediated by upregulation of specific transcription factors.

We have investigated the response to BET inhibition in patient-derived xenographs (PDXs) from patients with advanced ER+ breast cancer ex vivo and in vivo. Specifically, 14 breast cancer PDXs (10 ER+/HER2- and 4 ER+/HER2+) that were resistant to CDK4/6i in vivo were treated with ZEN-3694, a selective BET inhibitor currently in clinical development. Nine of the PDXs were sensitive to BET inhibition in monotherapy (65%). The non-responder PDXs showed an improved response when they were treated with ZEN-3694 in combination with fulvestrant (a selective ER degrader) or with a CDK4/6 inhibitor (ribociclib or abemaciclib). RNA-seq and computational analyses comparing responder versus non-responder PDXs revealed 493 differential expressed genes for responders, and 252 for non-responders. From those, 142 genes were differentially expressed in both conditions (untreated and treated). Furthermore, phosphorylation of BRD4 was observed in the ZEN-3694 non-responder PDX group, a mechanism of resistance previously observed in triple-negative breast cancer cell lines. This phosphorylation was abrogated by adding a CDK4/6 inhibitor. In the PDXs, resistance to single agent CDK4/6 and BET inhibitors might be overcome using a combination of both inhibitors. Finally, the molecular mechanism involved in phosphorylation of BRD4 was characterized in a MCF-7 cell line resistant to CDK4/6 inhibitors. Our results show that CDK2 could be one of the kinases involved in the phosphorylation of BRD4.

Conclusion: BET inhibition has an impact in advanced ER+ breast cancer cells, either used alone or in combination with endocrine therapy and CDK4/6 inhibitors. Detection of phosphorylated BRD4 (as a mechanism of resistance to BETi) has high potential for use as a biomarker for selecting patients who could benefit from a combined treatment of BET and CDK4/6 inhibitors.

Citation Format: Marc Cosín, Tian Tian, Winona Oliveros, Olesya A. Kharenko, Edward H. van der Horst, Reena G. Patel, Cyrus Calosing, Eric Campeau, Ravi Jahagirdar, Sanjay Lakhotia, Marta Melé, Marta Palafox, Joaquín Arribas, Mafalda Oliveira, Cristina Saura, Violeta Serra, Sandra Peiro. Overcoming resistance to inhibitors of CDK4/6 and BET in estrogen receptor-positive breast cancer [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 1282.

A kinetic study and the glass-reinforced composites of a liquid diglycidyl ether of bisphenol-P epoxy resin

The curing reaction of liquid epoxy resin based on l,l'-bis(4-hydroxyphenyl) cyclopentane with different amines, in the presence or absence of a fortifier, has been studied by differential scanning calorimetry (DSC). The glass-fibre-reinforced composites of liquid diglycidyl ether of bisphenol-P (DGEBP) were prepared using different amines as curing agent with/without fortifier and evaluated for their physical properties (such as density,% resin content and% void content) and mechanical properties (such as flexural strength, interlaminar shear strength and shore-D hardness). The laminates were also evaluated for their chemical resistance and electrical properties. It was found that using an epoxy fortifier (PGEHA) reduces the mechanical properties of the DGEBP-curing agent system.

Studies on the Properties of Glass-Reinforced Polyurethane Composites and Thick Films

Thick films and glass-reinforced composites of the totuene 2,4-diisocyanate-based urethane derivative of the acrylated diglycidylether of bisphenol-A were prepared using various amines such as hexamethylene diamine (HMDA), 4,4'-methylene bis(2-chloroaniline) (MOCA), benzidine (Bz) and diaminodiphenylmethane (DDM) as curing agents. The characterization of these laminates and thick films included mechanical properties, dielectric properties and chemical resistance properties. It was observed that neat resin casts and laminates behaved as very good insulating materials and showed good resistance towards chemicals.

Data on gene and protein expression changes induced by apabetalone (RVX-208) in ex vivo treated human whole blood and primary hepatocytes

Apabetalone (RVX-208) inhibits the interaction between epigenetic regulators known as bromodomain and extraterminal (BET) proteins and acetyl-lysine marks on histone tails. Data presented here supports the manuscript published in Atherosclerosis “RVX-208, a BET-inhibitor for Treating Atherosclerotic Cardiovascular Disease, Raises ApoA-I/HDL and Represses Pathways that Contribute to Cardiovascular Disease” (Gilham et al., 2016) [1]. It shows that RVX-208 and a comparator BET inhibitor (BETi) JQ1 increase mRNA expression and production of apolipoprotein A-I (ApoA-I), the main protein component of high density lipoproteins, in primary human and African green monkey hepatocytes. In addition, reported here are gene expression changes from a microarray-based analysis of human whole blood and of primary human hepatocytes treated with RVX-208.

Abstract LB-207: Preclinical characterization of ZEN-3694, a novel BET bromodomain inhibitor entering phase I studies for metastatic castration-resistant prostate cancer (mCRPC)

Metastatic castration resistant prostate cancer (mCRPC) is a major unmet medical need due to its widespread occurrence and incurable status. Current standard of care for advanced prostate cancer is androgen-deprivation therapy (ADT), and upon failure, patients are administered secondary ADT with androgen receptor (AR) antagonists such as enzalutamide and abiraterone. While most patients display an initial response to these agents, eventually all become resistant via various mechanisms that often result in constitutive AR signaling including mutations of the AR, and the generation of AR splice variants that bypass the ligand binding domain. Other mechanisms of resistance to AR antagonists include up-regulation of the glucocorticoid receptor (GR), and partial to complete loss of AR signaling through neuroendocrine differentiation. Recent evidence suggests that BET bromodomain inhibitors (BETi) could be efficacious in AR-signaling positive or negative mCRPC that are resistant to current therapies.

ZEN-3694 is an orally bioavailable, potent BETi that selectively binds to both bromodomains of the BET proteins. In vitro, ZEN-3694 has demonstrated strong activity against several prostate cancer cell lines with submicromolar potency, including AR positive and AR negative, neuroendocrine, and enzalutamide resistant cell lines. In VCaP AR-positive prostate cancer cells, ZEN-3694 inhibited proliferation synergistically with enzalutamide, resulting in potent up-regulation of the CDKN1C/KIP2 tumor suppressor gene. In 22Rv1 cells displaying constitutive AR signaling through the AR-V7 splice variant, ZEN-3694 inhibited AR signaling, and in an in vitro LNCaP model of acquired resistance to enzalutamide characterized by GR up-regulation, ZEN-3694 decreased levels of GR in a dose-dependent manner. Furthermore, in the PC3 AR-null cell line, the expression of a subset of NF-KB-dependent genes reported to be involved in mCRPC bone metastasis was found to be inhibited by ZEN-3694. In vivo, using multiple prostate cancer cell line xenografts such as 22Rv1, and VCaP, ZEN-3694 showed efficacy in inhibiting tumor progression at well-tolerated doses, and modulating target gene expression. ZEN-3694 also inhibited progression of a patient-derived xenograft (PDX) LuCaP 35CR that is resistant to enzalutamide.

In summary, our results indicate that ZEN-3694 demonstrates potent activity in advanced metastatic prostate cancer targeting multiple mechanisms of enzalutamide resistance in CRPC, including AR-V7 signaling and GR up-regulation in different preclinical models. This together supports the clinical development of ZEN-3694 as a single agent, and in combination with enzalutamide in mCRPC patients that have failed first line ADT. We are implementing a robust translational medicine program in the phase 1 study to measure target engagement and explore mechanisms of enzalutamide resistance and sensitivity to ZEN-3694 in patients.

Citation Format: Sarah Attwell, Ravi Jahagirdar, Karen Norek, Cyrus Calosing, Laura Tsujikawa, Olesya A. Kharenko, Reena G. Patel, Emily M. Gesner, Eva Corey, Holly M. Nguyen, Sanjay Lakhotia, Henrik C. Hansen, Eric Campeau. Preclinical characterization of ZEN-3694, a novel BET bromodomain inhibitor entering phase I studies for metastatic castration-resistant prostate cancer (mCRPC). [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr LB-207.

RVX-297- a novel BD2 selective inhibitor of BET bromodomains

Bromodomains are epigenetic readers that specifically bind to the acetyl lysine residues of histones and transcription factors. Small molecule BET bromodomain inhibitors can disrupt this interaction which leads to potential modulation of several disease states. Here we describe the binding properties of a novel BET inhibitor RVX-297 that is structurally related to the clinical compound RVX-208, currently undergoing phase III clinical trials for the treatment of cardiovascular diseases, but is distinctly different in its biological and pharmacokinetic profiles. We report that RVX-297 preferentially binds to the BD2 domains of the BET bromodomain and Extra Terminal (BET) family of protein. We demonstrate the differential binding modes of RVX-297 in BD1 and BD2 domains of BRD4 and BRD2 using X-ray crystallography, and describe the structural differences driving the BD2 selective binding of RVX-297. The isothermal titration calorimetry (ITC) data illustrate the related differential thermodynamics of binding of RVX-297 to single as well as dual BET bromodomains.

RVX-208, a BET-inhibitor for treating atherosclerotic cardiovascular disease, raises ApoA-I/HDL and represses pathways that contribute to cardiovascular disease

High density lipoproteins (HDL), through activity of the main protein component apolipoprotein A-I (ApoA-I), can reduce the risk of cardiovascular disease (CVD) by removing excess cholesterol from atherosclerotic plaque. In this study, we demonstrate that the bromodomain and extraterminal domain (BET) inhibitor RVX-208 increases ApoA-I gene transcription and protein production in human and primate primary hepatocytes. Accordingly, RVX-208 also significantly increases levels of ApoA-I, HDL-associated cholesterol, and HDL particle number in patients who received the compound in recently completed phase 2b trials SUSTAIN and ASSURE. Moreover, a post-hoc analysis showed lower instances of major adverse cardiac events in patients receiving RVX-208. To understand the effects of RVX-208 on biological processes underlying cardiovascular risk, we performed microarray analyses of human primary hepatocytes and whole blood treated ex vivo. Overall, data showed that RVX-208 raises ApoA-I/HDL and represses pro-inflammatory, pro-atherosclerotic and pro-thrombotic pathways that can contribute to CVD risk.

Cardiovascular changes in children with mucopolysaccharide disorders

The aims of this study were to evaluate cardiac involvement, assess risk factors and mortality, and define the outcome of cardiac abnormalities with age in the different types of mucopolysaccharidoses (MPS). The echocardiograms of 99 patients with MPS, aged 1-24 y (median age 10.3 y) were reviewed between 1978 and 2000. Mitral regurgitation (MR) was detected in 29 patients (29%). MR was more frequent in types IH [n = 11 (38%)], II [n = 10 (24%)] and III [n = 4 (20%)]. Sixteen patients (16%) developed aortic regurgitation (AR), seen mostly in types II [n = 9 (56%)] and IV [n = 4 (24%)]. AR and/or MR was detected in 37 patients and 8 had both abnormalities of borderline significance (odds ratio 2.95, 95% confidence interval 1.0-8.85, p = 0.05). Of 99 patients, 47 had a normal study on their first echocardiogram, whereas only 7 had a normal study on subsequent echocardiograms. Fifty-four (54%) had a single echocardiogram. Of these, 27 (50%) were abnormal and 27 normal. Forty-five patients had more than one echocardiogram, of which 25 (56%) were abnormal and 20 normal. In 13/20 (65%) a cardiac abnormality developed on a subsequent echocardiogram which was statistically significant (p = 0.002). Overall mitral and aortic valve abnormalities showed a positive association with age. Univariate analysis of risk factors showed that increasing age, MPS I and ejection fraction were significant risk factors for death. However, left ventricular hypertrophy, mitral valve abnormalities and type II MPS were not significant risk factors for death, with borderline significance for aortic valve abnormalities.

CONCLUSION

This study demonstrates the evaluation of ventricular function, which is a significant risk factor for death, along with increasing age and MPS I, and outlines the borderline significance of aortic valve abnormalities, which has not been mentioned in previous studies. It also shows that mitral valve lesions, commonly seen in MPS, were not a significant risk factor for death. The results emphasize the importance of performing serial echocardiograms in patients with MPS to assess ventricular function and the progression of cardiac abnormalities with age.

N-methyl-D-aspartate receptors regulate a group of transiently expressed genes in the developing brain

Mammalian brain development requires the transmission of electrical signals between neurons via the N-methyl-d-aspartate (NMDA) class of glutamate receptors. However, little is known about how NMDA receptors carry out this role. Here we report the first genes shown to be regulated by physiological levels of NMDA receptor function in developing neurons in vivo: NMDA receptor-regulated gene 1 (NARG1), NARG2, and NARG3. These genes share several striking regulatory features. All three are expressed at high levels in the neonatal brain in regions of neuronal proliferation and migration, are dramatically down-regulated during early postnatal development, and are down-regulated by NMDA receptor function. NARG2 and NARG3 appear to be novel, while NARG1 is the mammalian homologue of a yeast N-terminal acetyltransferase that regulates entry into the G(o) phase of the cell cycle. The results suggest that highly specific NMDA receptor-dependent regulation of gene expression plays an important role in the transition from proliferation of neuronal precursors to differentiation of neurons.

Pulmonary sarcoidosis: presentation as bilateral spontaneous hydropneumothorax and pulmonary infiltrates

Pulmonary manifestations in sarcoidosis vary, ranging from asymptomatic chest radiographic abnormalities to progressive destruction of lung parenchyma with respiratory insufficiency. We describe a case of sarcoidosis in a patient with bilateral hydropneumothorax, parenchyma infiltrates, and respiratory insufficiency. Hydropneumothorax is extremely rare, and to our knowledge only two cases have been reported.

Percutaneous transtracheal jet ventilation: a safe, quick, and temporary way to provide oxygenation and ventilation when conventional methods are unsuccessful

INTRODUCTION

Percutaneous transtracheal jet ventilation (PTJV) with a large-bore angiocath that is inserted through the cricothyroid membrane can provide immediate oxygenation from a high-pressure (50 lb per square inch) oxygen wall outlet, as well as ventilation by means of manual triggering. The objective of this retrospective study is to highlight the potential benefit of PTJV as a temporary lifesaving procedure during difficult situations when oral endotracheal intubation is unsuccessful and bag-valve-mask ventilation is ineffective for oxygenation during acute respiratory failure.

METHODS

The medical records of 29 consecutive patients who required emergent PTJV within the past 4 years were reviewed. PTJV was required because the pulse O(2) saturation could not be maintained at > 90% with bag-mask-valve ventilation and because the airway could not be secured quickly with direct laryngoscopy.

RESULTS

The cricothyroid membrane was cannulated successfully in 23 patients. In these patients, pulse O(2) saturation was raised to > 90% and was maintained with PTJV until the airway was secured. All but 3 of the 23 patients were subsequently intubated orally. In one patient, PTJV maintained adequate gas exchange until an emergent tracheostomy was performed. In two patients, airway exchange catheters were inserted into the trachea due to a small glottic aperture. The endotracheal tube was slid over the catheter. In 6 of the 29 patients, there was difficulty inserting a catheter through the cricothyroid membrane or there was inability to insufflate the oxygen with a jet ventilator. There were no immediate fatalities from the use of PTJV.

CONCLUSION

Based on the subsequent insertion of an endotracheal tube into the trachea, there were two important benefits in the patients who underwent PTJV successfully. First, PTJV provided effective oxygenation, while allowing adequate time for upper airway visualization and possible suctioning of oropharyngeal secretions. Second, tracheal intubation was subsequently easier, possibly because the high tracheal pressure from the gas insufflation opened the collapsed glottis, making visualization of the glottic aperture better. PTJV is safe and quick in providing immediate oxygenation, and therefore should be considered as an alternative to insistent, multiple intubation attempts, when neither bag-mask-valve ventilation nor endotracheal intubation is feasible in providing adequate gas exchange.

Transcatheter closure of a mid-muscular ventricular septal defect with an amplatzer VSD occluder device

A 5 year old girl with a haemodynamically significant mid-muscular ventricular septal defect (VSD) had successful transcatheter closure using the Amplatzer VSD occluder. This device passes through a small diameter sheath and can be easily retrieved or repositioned. These properties may make it a suitable device for closure of large mid-muscular defects in small children.

Near fatal acute respiratory distress syndrome in a patient with human ehrlichiosis

Human ehrlichiosis is not a common cause of acute respiratory distress syndrome (ARDS). Physicians should be aware of this life-threatening but treatable entity. Progression to ARDS may be related to delay in diagnosis and treatment. Fever, leukopenia, thrombocytopenia, and a history of tick exposure in an endemic area during the spring and summer months should alert the physician to the possibility of human ehrlichiosis, since a definitive diagnosis requires serologic testing that may take weeks to confirm. We describe a case of ARDS resulting from human ehrlichiosis. A unique feature in our case was that despite the early use of doxycycline, the patient had near fatal ARDS that responded dramatically to high doses of steroids.

Clinical presentation, radiographic findings, and diagnostic methods of pulmonary blastomycosis: a review of 100 consecutive cases

BACKGROUND

We sought to determine the relationship among radiographic findings, clinical presentation, and diagnostic testing of pulmonary blastomycosis.

METHODS

We reviewed the medical records of 100 consecutive patients with pulmonary blastomycosis.

RESULTS

Air-space infiltrates were the usual radiographic finding of pulmonary blastomycosis. Mass-like infiltrates were associated more with chronic than acute presentations. Air-space and mass-like infiltrate were predominately involved in the upper lobes. Sputum analysis made the initial diagnosis of blastomycosis most often. Acute and chronic presentations were not different between immunosuppressed patients and the remainder of the patients. In addition, infiltrates on chest radiographs in immunosuppressed patients were similar to the other patients.

CONCLUSIONS

In an endemic area, pulmonary blastomycosis should be considered for any pulmonary infiltrate, especially in the upper lobes. Sputum analysis in most cases aids in the diagnosis, but bronchoscopy and/or tissue biopsy should be considered if the suspicion of blastomycosis is high and sputum analysis is inconclusive, negative, or not possible. Follow-up with chest radiographs after antifungal therapy is reasonable until complete resolution or fibrotic changes in patients with pulmonary blastomycosis.

Respiratory muscle performance, pulmonary mechanics, and gas exchange between the BiPAP S/T-D system and the Servo Ventilator 900C with bilevel positive airway pressure ventilation following gradual pressure support weaning

STUDY OBJECTIVE

Our objective was to compare respiratory muscle performance, pulmonary mechanics, and gas exchange between the BiPAP S/T-D ventilation system (Respironics Inc; Murrysville, PA) and the Servo Ventilator 900C (Siemens-Elma AB; Sweden) with similar inspiratory and expiratory airway pressure in patients who are recovering from acute respiratory failure.

STUDY DESIGN

A prospective, randomized, clinical trial.

SETTING

Medical ICU.

PATIENTS AND METHODS

We studied 27 medical patients on mechanical ventilators following gradual pressure support weaning. Each patient breathed while in the following equivalent modes: (a) an inspiratory pressure preset (pressure support mode) of 5 cm H2O with an external positive end-expiratory pressure (PEEP) of 5 cm H2O on the Servo Ventilator 900C and (b) an inspiratory pressure preset of 10 cm H2O with an expiratory pressure preset of 5 cm H2O on the BiPAP S/T-D. Using the CP-100 pulmonary monitor, we compared the total work of breathing (WOB), the pressure-time index (PTP), and other pulmonary mechanics and gas exchange parameters between the two modes.

RESULTS

The WOB injoules per liter (mean +/- SE) (0.76+/-0.08 vs 0.73+/-0.08, p = 0.70), the WOB in joules per minute (8.62+/-1.06 vs 8.11+/-0.96, p = 0.60), and the PTP in cm H2O/s/min (187+/-18 vs 167+/-18, p = 0.21) between the BiPAP S/T-D and the Servo Ventilator 900C were not statistically different. There were statistically significant differences between the two ventilators in auto-PEEP (1.34+/-0.37 vs 0.88+/-0.30 cm H2O, p = 0.03), duty cycle (0.44+/-0.01 vs 0.37+/-0.01, p < 0.001), and expiratory airway resistance (11.81+/-1.53 vs 8.75+/-1.22 cm H2O/L/s, p < 0.001), but not in respiratory rate (27.48+/-1.54 vs 28.06+/-1.61 breaths/min, p = 0.40) or in minute ventilation (10.43+/-0.59 vs 10.27+/-0.37 L/min, p = 0.66). There was a statistically significant difference in the ratio of Pa(O2) to the fraction of inspired oxygen (F(IO2)) (333+/-21 vs 300+/-22, p < 0.03) but not in Pa(CO2) (48+/-2 vs 47+/-2 mm Hg, p = 0.59) between the BiPAP S/T-D and the Servo Ventilator 900C.

CONCLUSIONS

Despite differences in initiating and maintaining the inspiratory and expiratory phases, in breathing circuits, and in ventilator circuits between the two ventilators, the performance of the BiPAP S/T-D is equally efficacious to that of a conventional mechanical ventilator in supporting respiratory muscles. Thus, the BiPAP S/T-D is safe and effective when used in mechanically ventilated patients recovering from acute respiratory failure who do not require total ventilatory support.

Pneumopericardium associated with face-mask continuous positive airway pressure

This is an uncommon case of a patient who developed pneumopericardium while being treated with face-mask continuous positive airway pressure (CPAP) for hypoxic respiratory failure following a coronary artery bypass graft surgery. A pneumopericardium detected by chest radiograph resolved completely after discontinuation of face-mask CPAP. Possible mechanisms that may have been involved in this unusual complication are reviewed.

Transcatheter occlusion of the patent ductus arteriosus with Cook detachable coils

OBJECTIVE

To report initial experience with a new occlusion device for native and residual patent ductus arteriosus.

DESIGN

Descriptive study of consecutive non-randomised patients undergoing a new method of patent ductus arteriosus closure with detachable coils.

SETTING

Tertiary centres for paediatric cardiology.

PATIENTS

71 consecutive patients, aged 1.2-22 years, with a patent ductus arteriosus (PDA) underwent elective transcatheter closure. 45 had native PDAs (group A) with a minimum diameter of 1.0 mm-5.0 mm (median 2.0 mm). A further 26 had undergone one or more previous occlusion attempts (group B).

INTERVENTIONS

A total of 133 detachable (Cook) spring coils were successfully implanted in 70 patients. The procedure was performed transvenously in 51 patients, retrograde arterially in 13, and by both routes in a further 6 patients. One 5 mm coil migrated but was successfully retrieved.

MAIN OUTCOME MEASURES

In group A colour flow Doppler echocardiography showed that complete occlusion was achieved in 40/45 (89%) at 24 hours, 41/45 (91%) at 1 month, and 44/45 (98%) by 6 months post procedure. Occlusion rates in residual PDAs were 22/25 (88%) occluded at 24 hours, 23/25 (92%) at 1 month, and 24/25 (96%) at 6 months follow up.

CONCLUSIONS

Transcatheter occlusion using detachable (Cook) spring coils is a safe and effective alternative to presently available devices. The delivery system allows full retrieval of the coil until a satisfactory position is obtained.

Oral anticoagulation in paediatric patients: dose requirements and complications

The lack of oral anticoagulant guidelines specific to paediatric practice has led to the adoption of adult regimens, often without scientific evidence of efficacy or safety. A two year prospective study of anticoagulant control was carried out in 45 children aged 9 months to 18 years, the majority of whom were receiving primary prophylactic anticoagulation. The main indication was congenital heart disease, either with (n = 8) or without (n = 34) mechanical valve prosthesis. During a follow up period of 602 patient months the average interval between visits was three weeks. Target international normalised ratios (INRs) were achieved on 62% and 39% of visits for children with low target INR (2.0-3.0) and high target INR (3.0-4.0) respectively. However warfarin dose was altered on only 22% of visits. Warfarin doses required to achieve a stable INR of 2.0-3.0 in 33 children were strongly correlated with weight [dose (mg/d) = 0.07 x weight (kg) + 0.54] but independently influenced by age. No thrombotic complications were recorded, and haemorrhagic events were infrequent (2.1% of visits) and, with one exception, minor. Safe outpatient oral anticoagulation is feasible in children, whose warfarin requirements appear moderately predictable and whose control is no more erratic than that of adults.

Strategies for maximizing your chances for weaning success. Limitations--and advantages--of common predictive indices

Using indices to predict weaning outcome can avoid premature extubation and unnecessary prolongation of ventilatory support. Unfortunately, none of the indices is consistently able to predict outcome. The key to successful weaning is to assess respiratory function repeatedly with several indices, not just one. The patient should be able to sustain spontaneous breathing for at least 24 hours on minimal partial ventilatory support (a pressure support or a continuous positive airway pressure of 5 cm H2O or a T piece, for example). Indices of maximal inspiratory pressure; work of breathing; and rapid, shallow breathing are useful in evaluating a patient's respiratory muscle performance; airway occlusion pressure is helpful as well when increased neuromuscular drive is a problem.

Unilateral hyperlucency with left lower lobe mass in a patient with bronchial asthma

Mucoepidermoid tumors are rare bronchial adenomas whose clinical presentation can mimic that of bronchial asthma. Bronchial adenoma should be included in the differential diagnosis of a patient with a persistent radiographic abnormality and clinical features of bronchial asthma. We present an adolescent female with a history suggestive of bronchial asthma and a persistent left lower lobe atelectasis, who later was found to have a low-grade mucoepidermoid tumor.

Insulin receptor monoclonal antibodies that mimic insulin action without activating tyrosine kinase

HTC rat hepatoma cells were transfected with human insulin receptor cDNA to a level of 40,000 receptors/cell. In these cells, as well as in nontransfected cells, insulin stimulated the uptake of alpha-aminoisobutyric acid. Two monoclonal antibodies directed against the human insulin receptor alpha subunit, like insulin, stimulated amino acid uptake in transfected HTC cells, but not in nontransfected HTC cells. The antibodies, in contrast to insulin, failed to stimulate insulin receptor tyrosine kinase activity, both in intact transfected cells and in cell free extracts prepared from them. These data suggest, therefore, that activation of insulin receptor tyrosine kinase may not be an obligatory step in all of the transmembrane signaling mechanisms of the insulin receptor.

Cardiac rhabdomyomata in tuberous sclerosis: their course and diagnostic value

Echocardiography was performed in 60 people with tuberous sclerosis to ascertain the prevalence and course of cardiac rhabdomyomata at different ages. Twenty five (58%) of 43 children had tumours, but only three (18%) of 17 adults. The tumours tended to remain the same size through childhood. Only three infants were included but evidence from this and some published case reports suggest that the tumours tend to regress in early infancy and again in adolescence. The prevalence of tumours in young infants with tuberous sclerosis is likely to be considerably above 50%. As other signs of tuberous sclerosis are usually absent at this age echocardiography may afford the most useful diagnostic test in early infancy.

Localization of the insulin-binding site to the cysteine-rich region of the insulin receptor alpha-subunit

Affinity-purified insulin receptor was photoaffinity labeled with a cleavable radioactive insulin photoprobe. Exhaustive digestion of the labeled alpha-subunit with endoproteinase Glu-C produced a major radioactive fragment of 23 kDa as a part of the putative insulin-binding domain. This fragment could contain either residues 205-316 or 518-633 of the alpha-subunit. Rat hepatoma cells and Chinese hamster ovary cells were transfected with cDNA encoding a human insulin receptor mutant with a deletion of the cysteine-rich region spanning amino acid residues 124-319. Insulin binding by these cells was not increased in spite of high numbers of the mutant insulin receptors being expressed. A panel of monoclonal antibodies which was specific for the receptor alpha-subunit and inhibited insulin binding immunoprecipitated the photolabeled 23-kDa receptor fragment but not the receptor mutant. A synthetic peptide containing residues 243-251 was specifically bound by agarose-insulin beads. We therefore suggest that the 23-kDa fragment contains residues 205-316, and that insulin binding occurs, in part, in the cysteine-rich region of the alpha-subunit.

Anomalous drainage of inferior vena cava to left atrium in association with total anomalous pulmonary venous drainage

Images

Unilateral absence or extreme hypoplasia of pulmonary veins

Images

The ECG in aortic stenosis. Value of TAVF and QV6

Fifty patients with a mean age of 9.2 years (range, 1.2 to 17.5 years) had cardiac catheterization performed under standardized conditions plus a scalar ECG the previous day. Twenty different direct measurements and 25 derived measurements from the ECG were correlated with the resting peak systolic gradient across the aortic valve. Some of the best correlations were with the measured TAVF, TV6, QV6, and the sum of SV1 + RV6 with r values between .33 and .59. Another group of different patients with isolated aortic stenosis were studied with measurements of the important ECG segments. The r value of this "test" series was similar to that of the original group, so the groups were pooled. The best three-term regression equation involved TAVF, QV6, and the sum (SV1 + RV6), with r = .636. A scoring system was also devised to predict severity. If the TAVF is 0.1 mV or less or the TV6 is 0.3 mV or less or if there is no Q in V6, the gradient may be high. In our series, the ECG estimation of resting peak systolic gradient across the aortic valve in aortic stenosis was enhanced by the inclusion of TAVF and QV6 in the regression equation, as well as SV1 + RV6.

Right ventricular volume determinations in 18 patients with pulmonary atresia and intact ventricular septum. Analysis of factors influencing right ventricular growth

Right ventricular growth was assessed angiocardiographically in 18 patients with pulmonary atresia, intact ventricular septum, and hypoplastic and hypertensive right ventricle. A variety of surgical procedures were performed. In only 12 patients (66.7%) was right ventricular-pulmonary artery continuity achieved (group 1). Nine of these 12 patients persisted with systemic or suprasystemic right ventricular pressures. Among the six patients in whom right ventricular-pulmonary artery continuity was not achieved (group 2), all maintained suprasystemic right ventricular pressures. Right ventricular growth was assessed in groups 1 and 2. The patients were also subdivided according to the qualitative degree of tricuspid regurgitation as determined angiocardiographically on right ventricular cineangiocardiograms at the preoperative catheter study. Right ventricular growth to normal levels as evidenced by change in right ventricular end-diastolic volume was rarely observed in group 2 patients. Among the four patients with severe tricuspid regurgitation and a large tricuspid valve, right ventricular growth to normal levels was achieved whether they were in group 1 or group 2. Right ventricular growth is thus predicated on numerous morphologic factors in these patients. However, reconstitution of right ventricular-pulmonary artery continuity and a nonobstructive tricuspid valve are probably two of the more important factors.

Congenital absence of the pulmonary valve associated with imperforate membrane type of tricuspid atresia, right ventricular tensor apparatus and intact ventricular septum: a curious developmental complex

We have presented the unique clinical and morphological features of 3 patients with an imperforate tricuspid valve and right ventricular tensor apparatus. Thus, despite valve tissue and apparatus, there was not a perforate atrioventricular connection. This most uncommon type of tricuspid atresia' was associated in all 3 cases with a congenitally absent pulmonary valve, an underdeveloped right ventricle, and a curious distortion of the ventricular septum. Indeed, 2 of these patients demonstrated severe disproportionate ventricular septal thickening, although histopathologic examination did not substantiate those features usually associated with a hypertrophic cardiomyopathy. Rather, microscopic examination revealed a sinusoidal malformation consisting of normal myocardial cells separated by branching ethothelial-lined channels which communicated with the right ventricular cavity. In addition, gross examination of these 3 specimens revealed an abnormally persistent right venous valve in 2, which subdivided the right atrium. Finally, these cases provide further evidence that the term 'tricuspid atresia' oversimplifies the observed morphological features.

Truncal or aortic valve stenosis in functionally single arterial trunk. A clinical, hemodynamic and pathologic study of six cases

Stenosis of the semilunar valve in the presence of a functionally single arterial trunk is uncommon. Three patients with truncus arteriosus, two with tetralogy of Fallot and pulmonary atresia and one with pulmonary atresia and intact septum were diagnosed as having stenosis of the truncal or aortic valve on the basis of clinical, echocardiographic, hemodynamic and angiocardiographic findings. Echocardiograms consistently showed multiple diastolic closure lines and abnormal semilunar valves in addition to the aortic override in five patients and hypoplastic right ventricle in the patient with pulmonary atresia and intact septum. Peak systolic gradients between the left ventricle and truncus (or aorta) at cardiac catheterization ranged from 20 to 47 mm Hg. Retrograde aortography confirmed a domed and stenotic semilunar valve. Cyanosis was progressive in the three patients with pulmonary atresia. Two patients had arterial anastomosis, and one had a right ventricle-pulmonary arterial graft in addition to aortic valvotomy. One of the three patients with truncus arteriosus underwent complete repair in addition to truncal valvotomy but he died in the post-operative period. The other two patients with truncus arteriosus died of intractable congestive cardiac failure before surgical intervention. It is suggested that the presence of semilunar valve stenosis in these patients adversely affects the prognosis. The myocardium is already jeopardized as a result of hypoxia in pulmonary atresia and left ventricular diastolic overload in patients with truncus arteriosus. The added burden of semilunar valve stenosis may further compromise the functional status of the myocardium.

Plasma digoxin levels in infants, children and adults, using a radioimmunoassay micromethod

The radioimmunoassay method for estimation of plasma digoxin concentration was modified to use samples of 0.1 ml plasma for use in infants and children. The optimal daily maintenance dose for neonates, infants, and children was found to be between 0.01 and 0.015 mg/kg. Despite high plasma digoxin concentration (3-4 ng/ml) in some infants and children, no evidence of toxicity was found on electrocardiogram. 3 patients with accidental overdose, however, had plasma digoxin levels above 5 ng/ml and 2 of these had atrioventricular block.

Safe amounts of contrast medium for angiocardiography in neonates and infants

The results were analysed of 485 (biplane) cineangiocardiograms performed in 200 consecutive cardiac investigations on neonates (under 4 wk) and infants (4 wk to 1 yr). 10 deaths occurred during or within 24 h of cardiac catheterization, all in patients who were profoundly acidemic because of their hemodynamic disturbance. A total dose of Cardio-Conray at any one investigation of 4-5 ml/kg body weight was satisfactory and without undue risk. Single injections of 1.5-2.0 ml/kg body weight were safe whilst providing optimal diagnostic information. The interval between multiple injections did not appear to affect the risk to the patients.

Results of total correction of the tetralogy of Fallot. Long-term haemodynamic evaluation at rest and during exercise

Postoperative haemodynamic evaluation was performed on 15 patients 7 to 14 years (mean, 11 years) after total intracardiac repair of Fallot's tetralogy. The average age of the patients at the time of postoperative catheterization was 20 years (range 12 to 29) and they were all asymptomatic. Before operation 11 patients were severely cyanosed and disabled and 4 had mild cyanosis with anoxic spells. The cardiac output and right heart pressures were measured at rest and after 5 minutes of submaximal exercise on a bicycle ergometer. It was shown that the degree of residual obstruction of the pulmonary outflow tract was slight and that the right ventricular/pulmonary arterial systolic gradient (RV/PA gradient) exceeded 20 mmHg (2-6 kPa) at rest in only 3 patients. The mean cardiac index at rest was 5-4 l min-1 m-2 which increased to 8-3 l min-1 m-2 during exercise. The response of the cardiac output during exercise was either normal or supranormal in 14 of the 15 patients. In the remaining patient the response was marginally below the normal range. Pulmonary valvular regurgitation was present in 8 patients but there was no detectable difference in the cardiac function of these patients compared with patients with competent pulmonary valves. Six of the patients investigated had also had cardiac catheterizations performed 1 to 4 years after operation. The results of the present study show that remarkably little change has occurred in their haemodynamic status in the intervening years. Though these results are encouraging, further studies are required to determine the eventual outcome of the RV pressure and volume overload.

Transposition of the great arteries. A review of 37 cases after Mustard's operation

Ihenacho, H. N. C., Patel, R. G., Singh, S. P., Astley, R., and Parsons, C. G. (1973).Thorax, 28, 448-452. Transposition of the great arteries. A review of 37 cases after Mustard's operation. Thirty-seven children with transposition of the great arteries have undergone Mustard's operation in Birmingham Children's Hospital from May 1968 to December 1971. Thirtythree of these had simple transposition of the great arteries and four were complicated. All but two had some previous palliative procedures. Ten patients died before discharge from hospital and there were two late deaths, one after three months and the other after eight months. Bleeding, dysrhythmia, and hypotension were common immediate postoperative complications, while recurrent heart failure and persistent atrioventricular block occurred in five and four patients respectively.

Pulmonary artery banding and subsequent repair in ventricular septal defect

Images