A low-dose thrombolytic infusion protocol for safe and successful treatment of left ventricular assist device thrombosis: a case series

Background

Pump thrombosis is a serious complication of continuous-flow left ventricular assist device (CF-LVAD) therapy. In this study, we aim to report a novel protocol of an intermittent, low-dose, and slow infusion of tissue plasminogen activator (alteplase).

Case summary

We treated seven LVAD pump thrombosis events (HeartMate® II and HeartWare) in four patients with a median age of 52 years (31-63), and all were female. The protocol was applied from January 2015 to December 2018, and it consisted of an intermittent, low-dose, and slow infusion of systemic thrombolytic therapy in the intensive care unit. This therapy resulted in successful resolution of pump thrombosis in six out of seven events. Bleeding complication occurred in one patient, which included a ruptured haemorrhagic ovarian cyst and a small cerebellar intra-parenchymal haemorrhage. All patients were discharged home in a stable condition, except one patient who died during hospitalization because of severe sepsis, pump thrombosis with subsequent pump exchange, and multi-organ failure.

Discussion

A low-dose, prolonged, and systemic thrombolytic infusion protocol is an effective and relatively safe treatment that can lead to a sustained resolution of pump thrombosis with low bleeding complications and failure rates.

The Quality of Coronary Artery Bypass Grafting Videos on YouTube

Objective  YouTube (YouTube LLC, San Bruno, California, United States), one of the most accessed sites on the internet, has become a widespread source of healthcare information for patients. Videos about coronary artery bypass grafts (CABG) have accrued tens of millions of views on the platform, yet their educational quality is unknown. This study investigates the educational landscape of videos regarding CABG procedures on YouTube. Methods YouTube was queried for "Coronary Artery Bypass Graft Surgery" and "Coronary Artery Bypass Graft Procedure". After applying exclusion criteria, 73 videos were assessed. Two independent reviewers rated the material with the Global Quality Scale (GQS) (5 = high quality, 0 = low quality) to judge educational value. A ratio of view count to days since upload was applied to assess video popularity. Source, modality, and date of upload were recorded for each video as well. Results An average GQS score of 2.94 was found, indicating poor educational quality of the 73 YouTube videos on CABG procedures. Videos uploaded by physicians (56/73; 76.7%) had a significantly higher average GQS score than those uploaded by non-physicians (p<0.001). When content was grouped by delivery method, physician-led presentations (24/73 or 32.9%) produced the highest average GQS score of 3.35; conversely, patient-friendly delivery methods (18/73 or 24.7%) yielded the lowest average GQS score of 2.36 (p<0.001). Neither the view ratio nor the days since upload significantly correlated with the educational quality of the video. Conclusion Although CABG videos are readily available on YouTube, they often contain considerable biases and misleading information. With online sources for healthcare education now commonplace, physicians must be aware of the vast quantities of low-quality videos patients often encounter when weighing different treatment options. Further analysis of CABG videos on YouTube may allow physicians to ameliorate this gap by producing videos that are not only high quality but highly viewed on the platform.

Resection of a giant thoracic solitary fibrous tumor treated with preoperative arterial coiling followed by a double-level thoracotomy

Solitary fibrous tumor (SFT) are rare pleura neoplasms often localized to middle or inferior hemithorax. A middle-aged woman presents to the emergency department following a motor vehicle accident, the computed tomography scan revealed a giant tumor occupying the entire left pleural cavity with a complete collapse of the left lung and substantial right deviation of heart and mediastinum. Using preoperative arterial coiling followed by a double-level thoracotomy we successfully resected the giant tumor. The SFT weighed ~10 lbs. At 2-month follow-up visit patient reports mild discomfort during strenuous movement/heavy lifting but denies any shortness of breath.

Antihypertensive drug treatment and susceptibility to SARS-CoV-2 infection in human PSC-derived cardiomyocytes and primary endothelial cells

The pathogenicity of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) has been attributed to its ability to enter through the membrane-bound angiotensin-converting enzyme 2 (ACE2) receptor. Therefore, it has been heavily speculated that angiotensin-converting enzyme inhibitor (ACEI) or angiotensin receptor blocker (ARB) therapy may modulate SARS-CoV-2 infection. In this study, exposure of human pluripotent stem cell-derived cardiomyocytes (hPSC-CMs) and human endothelial cells (hECs) to SARS-CoV-2 identified significant differences in protein coding genes involved in immunity, viral response, and cardiomyocyte/endothelial structure. Specifically, transcriptome changes were identified in the tumor necrosis factor (TNF), interferon α/β, and mitogen-activated protein kinase (MAPK) (hPSC-CMs) as well as nuclear factor kappa-B (NF-κB) (hECs) signaling pathways. However, pre-treatment of hPSC-CMs or hECs with two widely prescribed antihypertensive medications, losartan and lisinopril, did not affect the susceptibility of either cell type to SARS-CoV-2 infection. These findings demonstrate the toxic effects of SARS-CoV-2 in hPSC-CMs/hECs and, taken together with newly emerging multicenter trials, suggest that antihypertensive drug treatment alone does not alter SARS-CoV-2 infection.

Paradoxical effects of cigarette smoke and COPD on SARS-CoV-2 infection and disease

BACKGROUND

How cigarette smoke (CS) and chronic obstructive pulmonary disease (COPD) affect severe acute respiratory syndrome coronavirus 2 (SARS-CoV2) infection and severity is controversial. We investigated the effects of COPD and CS on the expression of SARS-CoV-2 entry receptor ACE2 in vivo in COPD patients and controls and in CS-exposed mice, and the effects of CS on SARS-CoV-2 infection in human bronchial epithelial cells in vitro.

METHODS

We quantified: (1) pulmonary ACE2 protein levels by immunostaining and ELISA, and both ACE2 and/or TMPRSS2 mRNA levels by RT-qPCR in two independent human cohorts; and (2) pulmonary ACE2 protein levels by immunostaining and ELISA in C57BL/6 WT mice exposed to air or CS for up to 6 months. The effects of CS exposure on SARS-CoV-2 infection were evaluated after in vitro infection of Calu-3 cells and differentiated human bronchial epithelial cells (HBECs), respectively.

RESULTS

ACE2 protein and mRNA levels were decreased in peripheral airways from COPD patients versus controls but similar in central airways. Mice exposed to CS had decreased ACE2 protein levels in their bronchial and alveolar epithelia versus air-exposed mice. CS treatment decreased viral replication in Calu-3 cells, as determined by immunofluorescence staining for replicative double-stranded RNA (dsRNA) and western blot for viral N protein. Acute CS exposure decreased in vitro SARS-CoV-2 replication in HBECs, as determined by plaque assay and RT-qPCR.

CONCLUSIONS

ACE2 levels were decreased in both bronchial and alveolar epithelial cells from COPD patients versus controls, and from CS-exposed versus air-exposed mice. CS-pre-exposure potently inhibited SARS-CoV-2 replication in vitro. These findings urge to investigate further the controversial effects of CS and COPD on SARS-CoV-2 infection.

Paradoxical effects of cigarette smoke and COPD on SARS-CoV2 infection and disease

Introduction

How cigarette smoke (CS) and chronic obstructive pulmonary disease (COPD) affect severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and severity is controversial. We investigated the protein and mRNA expression of SARS-CoV-2 entry receptor ACE2 and proteinase TMPRSS2 in lungs from COPD patients and controls, and lung tissue from mice exposed acutely and chronically to CS. Also, we investigated the effects of CS exposure on SARS-CoV-2 infection in human bronchial epithelial cells.

Methods

In Cohort 1, ACE2-positive cells were quantified by immunostaining in FFPE sections from both central and peripheral airways. In Cohort 2, we quantified pulmonary ACE2 protein levels by immunostaining and ELISA, and both ACE2 and TMPRSS2 mRNA levels by RT-qPCR. In C57BL/6 WT mice exposed to air or CS for up to 6 months, pulmonary ACE2 protein levels were quantified by triple immunofluorescence staining and ELISA. The effects of CS exposure on SARS-CoV-2 infection were evaluated after 72hr in vitro infection of Calu-3 cells. After SARS-CoV-2 infection, the cells were fixed for IF staining with dsRNA-specific J2 monoclonal Ab, and cell lysates were harvested for WB of viral nucleocapsid (N) protein. Supernatants (SN) and cytoplasmic lysates were obtained to measure ACE2 levels by ELISA.

Results

In both human cohorts, ACE2 protein and mRNA levels were decreased in peripheral airways from COPD patients versus both smoker and NS controls, but similar in central airways. TMPRSS2 levels were similar across groups. Mice exposed to CS had decreased ACE2 protein levels in their bronchial and alveolar epithelia versus air-exposed mice exposed to 3 and 6 months of CS. In Calu3 cells in vitro, CS-treatment abrogated infection to levels below the limit of detection. Similar results were seen with WB for viral N protein, showing peak viral protein synthesis at 72hr.

Conclusions

ACE2 levels were decreased in both bronchial and alveolar epithelial cells from uninfected COPD patients versus controls, and from CS-exposed versus air-exposed mice. CS-pre-treatment did not affect ACE2 levels but potently inhibited SARS-CoV-2 replication in this in vitro model. These findings urge to further investigate the controversial effects of CS and COPD on SARS-CoV2 infection.

Cardiac Regeneration in the Human Left Ventricle After CorMatrix Implantation

CorMatrix is an organic extracellular matrix (ECM) derived from porcine small intestine submucosa and is used for pericardial closure and cardiac tissue repair. During explantation of a HeartMate II (Thoratec Corp, Pleasanton, CA) left ventricular assist device (LVAD) because of infection, CorMatrix was used to repair the left ventricular apex and aorta. Three months later, a HeartWare HVAD (HeartWare International, Inc, Framingham, MA) was implanted for recurrent heart failure. Excised apical CorMatrix samples showed cardiac tissue remodeling with viable cardiomyoblasts similar to native myocardium. Excised CorMatrix from the aorta showed organization of collagen and elastin similar to native aortic tissue.

Bileaflet Foldoplasty in Barlow’s Disease

Mitral valve repair is a feasible and preferable option for the treatment of Barlow's disease. Complex valve repair techniques, in contrast, often lead to increased cross-clamp times and low cardiac output syndrome. A simple, fast, and reproducible foldoplasty technique to reduce anterior and posterior mitral leaflet heights may improve coaptation and reduce mitral regurgitation. Accordingly, herein are described minimally invasive, successful trans-septal and robotic approaches for a bileaflet foldoplasty technique in two patients with Barlow's disease.

A modified Park's stitch to correct aortic insufficiency for bioprosthetic valve at time of left ventricular assist device implant: a case report

Background

Aortic valve insufficiency (AI) at the time of left ventricular assist device (LVAD) insertion needs to be corrected, however there is little known about how to manage bioprosthetic valvular AI.

Case presentation

A 55-year-old female with dilated cardiomyopathy who previously had a bioprosthetic aortic valve replacement needed a LVAD as a bridge to transplant. Her left ventricular ejection fraction was 10% and had mild to moderate transvalvular AI. She underwent a HeartWare HVAD insertion along with aortic valvular coaptation stitch repair (Park's stitch) to the bioprosthetic valve.

Conclusion

Her AI improved to trivial with minimal ejection through the bioprosthetic valve. She was transplanted 6 months following the surgery. A Park's stitch to the bioprosthetic aortic valve with more than mild AI might be a good option for bridge to transplant patient.

Analysis of pulmonary non-tuberculous mycobacterial infections after lung transplantation

PURPOSE

Non-tuberculous mycobacteria (NTM) are important pathogens in lung transplant recipients. This study describes the spectrum of NTM respiratory tract infections and examines the association of NTM infections with lung transplant complications.

METHODS

Data from 208 recipients transplanted from November 1990 to November 2005 were analyzed. Follow-up data were available to November 2010. Lung infection was defined by bronchoalveolar lavage, sputum, or blood cultures in the appropriate clinical setting. All identified NTM respiratory tract infections were tabulated. The cohort of patients with NTM lung infections (NTM+) were compared to the cohort without infection (NTM-). Univariate and multivariate analysis was performed to determine characteristics associated with NTM infection. Survival analyses for overall survival and development of bronchiolitis obliterans syndrome (BOS) were also performed.

RESULTS

In total, 52 isolates of NTM lung infection were identified in 30 patients. The isolates included Mycobacterium abscessus (46%), Mycobacterium avium complex (MAC) (36%), Mycobacterium gordonae (9%), Mycobacterium chelonae (7%), and Mycobacterium fortuitum (2%), with multiple NTM isolates seen on 3 different occasions. The overall incidence was 14%, whereas cumulative incidences at 1, 3, and 5 years after lung transplantation were 11%, 15%, and 20%, respectively. Comparisons between the NTM+ and NTM- cohorts revealed that NTM+ patients were more likely to be African-American and have cytomegalovirus mismatch. Although no difference was seen in survival, the NTM+ cohort was more likely to develop BOS (80% vs. 58%, P = 0.02). NTM+ infection, however, was not independently associated with development of BOS by multivariate analysis.

CONCLUSION

With nearly 20 years of follow-up, 14% of lung recipients develop NTM respiratory tract infections, with M. abscessus and MAC more commonly identified. M. gordonae was considered responsible for nearly 10% of NTM infections. Although survival of patients with NTM infections is similar, a striking difference in BOS rates is present in the NTM+ and NTM- groups.

Case Report: Disparate flow in HeartMate II patient with extensive left ventricle repair

This case study reports the operative management of a 63-year-old male patient following implantation of the HeartMate II (HMII) left ventricular assist device (LVAD), with a non-compliant left ventricle (LV) and a reduced right ventricular (RV) end-diastolic volume. Intraoperatively, the patient had a thin, fragile LV wall with laminated clot; a ventricular septal defect was encountered during removal of the clot. Along with an aortic valve repair, the LV and the septum were reconstructed with multiple bovine pericardium patches, thus, moderately reducing the RV and LV stroke volume. A difference in cardiac output via a Swan-Ganz catheter (approximately 1.5 l/min) was observed as opposed to the HMII's estimated flow. The result was later replicated and verified ITALIC! in vitrovia the Donovan Mock Circulation System (DMCS), where about 2 l/min lower flow on the HMII system was observed. In conclusion, the HMII flow rate displayed can be inaccurate and should only be used for trending.

Production and assessment of decellularized pig and human lung scaffolds

The authors have previously shown that acellular (AC) trachea-lung scaffolds can (1) be produced from natural rat lungs, (2) retain critical components of the extracellular matrix (ECM) such as collagen-1 and elastin, and (3) be used to produce lung tissue after recellularization with murine embryonic stem cells. The aim of this study was to produce large (porcine or human) AC lung scaffolds to determine the feasibility of producing scaffolds with potential clinical applicability. We report here the first attempt to produce AC pig or human trachea-lung scaffold. Using a combination of freezing and sodium dodecyl sulfate washes, pig trachea-lungs and human trachea-lungs were decellularized. Once decellularization was complete we evaluated the structural integrity of the AC lung scaffolds using bronchoscopy, multiphoton microscopy (MPM), assessment of the ECM utilizing immunocytochemistry and evaluation of mechanics through the use of pulmonary function tests (PFTs). Immunocytochemistry indicated that there was loss of collagen type IV and laminin in the AC lung scaffold, but retention of collagen-1, elastin, and fibronectin in some regions. MPM scoring was also used to examine the AC lung scaffold ECM structure and to evaluate the amount of collagen I in normal and AC lung. MPM was used to examine the physical arrangement of collagen-1 and elastin in the pleura, distal lung, lung borders, and trachea or bronchi. MPM and bronchoscopy of trachea and lung tissues showed that no cells or cell debris remained in the AC scaffolds. PFT measurements of the trachea-lungs showed no relevant differences in peak pressure, dynamic or static compliance, and a nonrestricted flow pattern in AC compared to normal lungs. Although there were changes in content of collagen I and elastin this did not affect the mechanics of lung function as evidenced by normal PFT values. When repopulated with a variety of stem or adult cells including human adult primary alveolar epithelial type II cells both pig and human AC scaffolds supported cell attachment and cell viability. Examination of scaffolds produced using a variety of detergents indicated that detergent choice influenced human immune response in terms of T cell activation and chemokine production.

Probable Phaeoacremonium parasiticum as a cause of cavitary native lung nodules after single lung transplantation

Lung nodules after lung transplantation most often represent infection or post-transplant lymphoproliferative disorder in the allograft. Conversely, native lung nodules in single lung transplant recipients are more likely to be bronchogenic carcinoma. We present a patient who developed native lung cavitary nodules. Although malignancy was anticipated, evaluation revealed probable Phaeoacremonium parasiticum infection. Phaeoacremonium parasiticum is a dematiaceous fungus first described as a cause of soft tissue infection in a renal transplant patient. Lung nodules have not been previously described and this is the first case, to our knowledge, of P. parasiticum identified after lung transplantation.

Rapid detection and differentiation of Campylobacter jejuni, Campylobacter coli, and Campylobacter lari in food, using multiplex real-time PCR

A multiplex real-time PCR assay based on four differently labeled TaqMan probes for detection and differentiation of the thermophilic Campylobacter species C. jejuni, C. coli, and C. lari was established and validated in food products. This assay combines two previously published PCR assays for C. jejuni and C. coli with a newly developed detection assay for C. lari and an internal amplification control system. The selectivity of the method was determined by analyzing 70 Campylobacter strains and 43 strains of other bacteria. The sensitivity was 50 fg of C. jejuni and C. lari DNA and 500 fg of C. coli DNA per PCR. It was possible to detect 1 to 10 CFU/25 g of food before preenrichment of all three species. More than 400 samples of various foods (poultry, seafood, and meat) were analyzed after 48 h of preenrichment parallel to the conventional diagnostic method of culture and biochemical identification. Using the established real-time PCR assay, 55.4% of the samples were recognized as positive for thermophilic Campylobacter species, whereas with the conventional method only 40.3% of the samples were positive. The real-time PCR assay also detected contaminations with two different Campylobacter species in 32.6% of the analyzed poultry samples, a finding of epidemiological interest. Compared with the original PCR method, which was established for the differentiation of bacterial isolates of C. jejuni and C. coli, this new method also detects and distinguishes C. lari, was validated as an analytical tool for food analysis, and provides reliable and extensive results within 2 days.

Infective coronary aneurysms: a complication of percutaneous coronary intervention

We present the case of a patient who developed infective coronary artery aneurysms after percutaneous coronary artery intervention. We describe the patient's clinical presentation, diagnosis, and treatment, and we review the pertinent medical literature.

Posterior sternoclavicular epiphyseal fracture-dislocation with delayed diagnosis

Posterior sternoclavicular joint dislocations and epiphyseal fractures are relatively rare injuries. We present a case report of a 16-year-old male who presented with a 10-day delay in diagnosis. The medial clavicular fragment was widely displaced and rested against the cervical vertebral body. Despite the degree of displacement, the patient had very few symptoms, and the diagnosis was not appreciated in the emergency department and became apparent at 10-day clinic follow-up. Treatment consisted of attempts at closed reduction, which were not successful. Open reduction was performed and the repair done with strong sutures. At 1-year follow-up the patient is doing well without any symptoms. A literature review consisting of anatomy, ossification patterns, classification systems, diagnosis and associated symptoms, imaging recommendations, treatment recommendations, outcomes, and complications is included.

Disseminated Acanthamoebiasis after Lung Transplantation

Protozoan infections in organ transplant recipients are rare. We report a fatal case of disseminated acanthamoebiasis in a bilateral lung transplant recipient that presented with cutaneous lesions, respiratory failure, and seizures. Acanthamoeba infection may be identified in transplant recipients with exposure to water who develop non-healing cutaneous ulcers with granulomatous inflammation. Cutaneous lesions are the initial manifestation of infection and a harbinger of dissemination. Early institution of combination anti-microbial therapy is therefore necessary for effective treatment and prevention of lethal spread to the central nervous system.

Chronic pseudoaneurysm and coarctation of the aorta: a rare delayed complication of trauma

We report an unusual case of pseudoaneurysm and coarctation of the descending thoracic aorta after trauma. The coarctation of aorta resulted in hypertension, severe left ventricular dysfunction, and symptoms of congestive heart failure. Surgical bypass resulted in control of blood pressure and improvement of heart failure symptoms. The mechanism of aortic injury leading to the development of this rare combination is discussed.

Contained myocardial rupture: a variant linking complete and incomplete rupture

Myocardial rupture is an uncommon complication of myocardial infarction, often with devastating haemodynamic consequences. Although rupture is usually fatal, when patients do survive, the majority present with a pseudoaneurysm in which the rupture is sealed by a haematoma on the epicardial surface of the heart. Cases in which all myocardial layers are dissected except the epicardium or visceral pericardium have been included under this subheading. The authors describe such a case and suggest the pathological description of a "contained myocardial rupture". This link between complete and incomplete myocardial rupture may allow a more conservative management approach to be pursued.

Toward Ambulatory Arteriovenous CO2 Removal: Initial Studies and Prototype Development

Extracorporeal arteriovenous carbon dioxide removal (AVCO2R) using percutaneous cannulae and a low resistance gas exchanger achieves near total CO2 removal, allowing lung rest and potentially improving survival. AVCO2R, redesigned to allow ambulation, has potential as treatment for severe chronic obstructive pulmonary disease or rehabilitation before lung transplant. The purposes of this study were to 1) determine the optimal ambulatory access for AVCO2 removal and 2) develop a prototype Ambulatory-AVCO2R gas exchanger. Initially, reinforced Gore-Tex 6 mm (two) and 8 mm (four) grafts were anastomosed to sheep carotid arteries and jugular veins as a loop in parallel to the cranial circulation to determine blood flow capabilities. Blood flow was 100-150 ml/min with a 14 gauge dialysis needle, and transected 6 mm Gore-Tex grafts achieved 500-900 ml blood flow, whereas transected 8 mm grafts achieved up to 2000 ml/min flow. The polytetrafluoroethylene (PTFE) loops were then connected to our newly developed ultra low resistance pumpless gas exchanger for ambulatory AVCO2R. The average pressure gradient across the prototype Ambulatory-AVCO2R gas exchangers (n = 5) was 2.8 +/- 0.8 mm Hg, and mean CO2 removal was 104.8 +/- 14.0 ml/min, with an average blood flow of 900 ml/min. We conclude that an 8 mm Gore-Tex reinforced graft arteriovenous loop supplies ample blood flow for our new ultra low resistance Ambulatory-AVCO2R to achieve near total CO2 removal.

Perioperative care of the lung transplant patient

Improvements in the perioperative management of lung transplant recipients have produced a 90% survival in the first 30 days following surgery. Detailed attention to donor organ procurement and preservation of the allograft are important in ensuring an early successful outcome. Early antibacterial administration based on donor or pretransplant cultures and antiviral therapy in CMV-negative recipients assist in avoiding early infectious complications. Development of hypoxemia or hemodynamic instability in the perioperative period requires a rapid, systematic evaluation with attention to mechanical, immunologic, or infectious causes. Nonpulmonary complications are not infrequent in lung transplant recipients.

Postischemic recovery of contractile function is impaired in SOD2(+/-) but not SOD1(+/-) mouse hearts

BACKGROUND

Reactive oxygen species (ROS) contribute to myocardial stunning. Superoxide dismutase (SOD) is a major defense mechanism against ROS. The purpose of this study was to evaluate the contributions of cytosolic (SOD1) and mitochondrial (SOD2) isoforms to protect against myocardial stunning.

METHODS AND RESULTS

Isolated hearts from wild-type, heterozygous (+/-) SOD1 and SOD2 knockout mice received 30 minutes of ischemia followed by 60 minutes of reperfusion. After 60 minutes of reperfusion, the heart rate multiplied by the developed pressure (HRxDP) in the wild-type and SOD1(+/-) hearts recovered to 92 +/- 9 and 85 +/- 7 of preischemic baseline values, respectively (P=NS). In contrast, the HRxDP was significantly lower (63 +/- 7%) in the SOD2(+/-) hearts compared with the wild-type hearts. Western blot analysis and enzymatic activity of tissue lysates confirmed reduction of activities of specific SOD isoforms without compensatory increase in the other isoform in the knockout animals studied.

CONCLUSIONS

Postischemic functional recovery is more sensitive to a partial deficiency of SOD2 than a partial deficiency of SOD1. Therefore, modulation of the mitochondrial SOD isoform is a critical determinant in the tolerance of the heart to oxidative stress.

Survival of Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus in the terminal ileum of fistulated Göttingen minipigs

The ability of Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus administered in yogurt to survive the passage through the upper gastrointestinal tract was investigated with Göttingen minipigs that were fitted with ileum T-cannulas. After ingestion of yogurt containing viable microorganisms, ileostomy samples were collected nearly every hour beginning 3 h after food uptake. Living L. delbrueckii subsp. bulgaricus and S. thermophilus were detected in the magnitude of 10(6) to 10(7) per gram of intestinal contents (wet weight) in all animals under investigation. A calculation of the minimum amount of surviving bacteria that had been administered is presented. Total DNA extracted from ileostomy samples was subjected to PCR, which was species specific for L. delbrueckii and S. thermophilus and subspecies specific for L. delbrueckii subsp. bulgaricus. All three bacterial groups could be detected by PCR after yogurt uptake but not after uptake of a semisynthetic diet. One pig apparently had developed an endogenous L. delbrueckii flora. When heat-treated yogurt was administered, L. delbrueckii was detected in all animals. S. thermophilus or L. delbrueckii subsp. bulgaricus was not detected, indicating that heat-inactivated cells and their DNAs had already been digested and their own L. delbrueckii flora had been stimulated for growth.

Identification of lactobacillus delbrueckii and subspecies by hybridization probes and PCR

Three methods addressing two different target sites were compared for identification and differentiation of the subspecies Lactobacillus delbrueckii subsp. bulgaricus and Lactobacillus delbrueckii subsp. lactis/delbrueckii. A PCR method - three primer pairs that enable direct identification of the species and the two subspecies, respectively - was derived from a DNA fragment showing significant similarities to parts of the addAB genes of Bacillus sutbtilis. In addition, two oligonucleotide probes for the two subspecies were designed from that DNA region. Further, two oligonucleotide probes targeting the 16S rDNA were developed for subspecies differentiation by a one base-pair difference following identification of the species. Moreover, these probes were demonstrated to be applicable for in situ hybridization experiments. The results obtained by the different methods were in good agreement.

Sporulation of Penicillium camemberti in submerged batch culture

Sporulation of Penicillium camemberti was studied in submerged batch fermentation. A defined medium was used with glucose and ammonium as C- and N-sources. Temperature was set to 25 degrees C at pH 5.6. Essential for submerged sporulation was the presence of calcium (14 mM) which was adsorbed to the cell walls in all sporulating strains and inhibited mycelial growth. Acetate led to highly branched conidiophores and was the second main factor for efficient sporulation. The chelating properties of citrate were necessary for keeping calcium and phosphate in solution. Fermentation conditions allowed high spore yields after 96 h (1.6 x 10(8) spores/ml). Cyclopiazonic acid, the mycotoxin common for P. camemberti was produced during fermentation. The levels observed (0.5-4 ppm at 96 h) were strain specific and not related to spore yield.

Thrombolysis with resolution of pulmonary hypertension in a heart transplant candidate

We report a patient with idiopathic cardiomyopathy and high pulmonary resistance due to pulmonary emboli of unknown age. Successful thrombolytic therapy returned his pulmonary resistance to normal, allowing orthotopic cardiac transplantation. This case underscores the need to aggressively diagnose and treat pulmonary emboli in potential transplant candidates.

Clinical utilization and complications of sural nerve biopsy

Surgeons frequently perform sural nerve biopsy as part of the work-up of patients with peripheral neuropathy. The indications for the procedure, therapeutic value, and complications associated with the procedure have received little attention in the surgical literature. A retrospective chart review of 60 patients with the suspected diagnosis of peripheral neuropathy undergoing sural nerve biopsy was performed. Vasculitis was suspected in 29 (48%) patients undergoing biopsy. This diagnosis was confirmed in 6 of the 29 patients and resulted in the alteration of therapy in 31% of patients with this suspected diagnosis. In 27 (45%) patients, the etiology of their peripheral neuropathy was unknown. Twelve (44%) patients in this group had sural nerve pathology; however, no change in therapy was required. Ten patients in our series had associated malignant tumors; some of these patients were diagnosed after referral for sural nerve biopsy. Twenty-five (42%) patients remained undiagnosed after biopsy. Nerve conduction studies were performed in 14 (22%) patients. Thirteen patients with abnormal lower extremity nerve conduction studies had 6 normal and 7 abnormal biopsy results. The one patient with a normal study had a normal nerve biopsy result. There were six (10%) patients with wound infections, seven (12%) patients with delayed wound healing, and three (5%) patients with new onset of chronic pain in the distribution of the sural nerve, for an overall complication rate of 27%. There was no correlation between the preoperative use of antibiotics, type of local anesthetic used, or length of nerve excised and complication rate. We conclude that the complication rate after sural nerve biopsy is significant. Strict criteria should be employed in selecting patients for sural nerve biopsy including a careful neurologic history and physical examination, nerve conduction studies, appropriate work-up for vasculitis if suspected, and implementation of a search for malignancy if this is not apparent. If the diagnosis is still in question, then sural nerve biopsy would seem appropriate, especially in patients with suspected vasculitis.

Use of the Symbion biventricular assist device in bridging to transplantation

From 1988 to 1991 13 patients received Symbion biventricular assist devices in attempts to bridge them to cardiac transplantation. All 7 of those who had cardiac transplants survived to hospital discharge. One death occurred 60 days after transplantation because of rejection. All other patients who received transplants are surviving. Implant times in this group varied from 10 to 164 days (mean, 55 days). There were two embolic neurologic events and two significant infections, and 2 of the survivors were dialyzed for reversible renal failure before transplantation. Of those who died on device support, 3 presented on centrifugal pump support. The three other deaths were caused by graft rejection, multiple organ failure, and multiple peripheral emboli. Biventricular assist devices optimally provide cardiac outputs of 4 to 5 L/min, can be quickly inserted often without requiring cardiopulmonary bypass, are easily explanted, and seem best suited for patients weighing less than 80 kg.

Long-term bridge to transplantation with the Symbion acute ventricular assist device system

A 48-year-old man was supported for 164 days with Symbion biventricular assist devices. During that time, his cytotoxic antibody screen fell from 97% positivity to less than 10%, enabling cardiac transplantation. Complications during the implantation included a 3-minute episode of amaurosis fugax, one positive blood culture, and anemia, which responded to decreased frequency of blood drawing. He is now alive 7 months after transplantation.

Successful epicardial pacing in blunt trauma resuscitation

Epicardial pacing wires were used successfully in the resuscitation of a moribund victim of blunt trauma after fluid resuscitation and chemical measures had failed. Application of these wires to treat the bradycardia of shock should be considered in selected patients when standard measures fail.

Effect of electrocautery on wound healing in midline laparotomy incisions

The effect of electrocautery on midline fascial wound healing was studied in 108 Sprague-Dawley rats. Midline wound tensile strength was significantly reduced in fascia incised with the coagulation current compared with the cutting current or scalpel. In addition, tissue necrosis and inflammation as well as adhesion formation between the incision and abdominal viscera were more extensive in animals with incisions made using coagulation current. The results of the study indicate that the use of electrocautery coagulation current is associated with increased tissue damage and a significant reduction in the tensile strength of healing wounds. The contribution of electrocautery to wound complications in patients needs further evaluation.