Simultaneous Heart-kidney Transplant With Planned Delayed Implantation of the Kidney Graft After Ex Vivo Perfusion

BACKGROUND

Simultaneous heart-kidney transplant (SHK) is an established option for patients with severe heart failure and chronic kidney disease. Recent studies in simultaneous liver-kidney transplantation demonstrate favorable outcomes achieved by delaying implantation of the kidney for over 24 h. This report describes a case series of consecutive patients listed for SHK who had planned delayed implantation of the kidney graft.

METHODS

This case series represents a retrospective analysis of SHK patients extracted from the transplant database at a single center.

RESULTS

There were 7 patients who underwent SHK during the study period. In all cases, kidney grafts were maintained on hypothermic ex vivo pulsatile perfusion for delayed implantation (mean cold ischemia 53 h [range, 31-69]). The first 5 patients had 100% 1-y heart and kidney graft survival with good function. Patient 6 was unstable on extracorporeal membrane oxygenation post-heart transplant. The kidney was implanted at 69 h, and the patient died soon thereafter. Patient 7 was also unstable on extracorporeal membrane oxygenation after heart transplant. The decision was made to implant the kidney into a backup kidney recipient. The heart transplant recipient subsequently died several days later, whereas the kidney was successfully transplanted in the alternate candidate.

CONCLUSIONS

This case series highlights the potential utility of delayed kidney implantation in SHK patients. SHK with delayed renal transplant may provide an improved physiologic environment for renal transplant, which may result in improved early renal graft function. Delayed kidney transplant also provides the opportunity to transplant the kidney graft into an alternate candidate.

Trousseau Syndrome in a 25-Year-Old Woman with Occult Colon Malignancy, Lynch Syndrome, and Chronic Thromboembolic Pulmonary Hypertension

We present a rare case of thrombosis associated with an occult colon malignancy (Trousseau syndrome) in a 25-year-old woman who also presented with previously unidentified Lynch syndrome and acute-on-chronic thromboembolic pulmonary hypertension. Staged treatment included bilateral pulmonary endarterectomy under deep hypothermic circulatory arrest, followed 11 days later by laparoscopic subtotal colectomy and creation of a primary anastomosis. The patient tolerated both procedures well and recovered normal functional status. Final pathologic analysis of the resected colon mass revealed a pT3N0, stage IIA adenocarcinoma; no adjuvant therapy was administered. At her one-year follow-up visit, the patient was cancer-free, remained on lifelong apixaban anticoagulation, and was undergoing routine monitoring and genetic counseling. This case highlights the need for multidisciplinary management of a patient with severe chronic thromboembolic pulmonary hypertension and a concomitant malignancy.

Intracellular Ca2+ Dysregulation in Coronary Smooth Muscle Is Similar in Coronary Disease of Humans and Ossabaw Miniature Swine

Intracellular free Ca2+ ([Ca2+]i) dysregulation occurs in coronary smooth muscle (CSM) in atherosclerotic coronary artery disease (CAD) of metabolic syndrome (MetS) swine. Our goal was to determine how CAD severity, arterial structure, and MetS risk factors associate with [Ca2+]i dysregulation in human CAD compared to changes in Ossabaw miniature swine. CSM cells were dispersed from coronary arteries of explanted hearts from transplant recipients and from lean and MetS swine with CAD. CSM [Ca2+]i elicited by Ca2+ influx and sarcoplasmic reticulum (SR) Ca2+ release and sequestration was measured with fura-2. Increased [Ca2+]i signaling was associated with advanced age and a greater media area in human CAD. Decreased [Ca2+]i signaling was associated with a greater number of risk factors and a higher plaque burden in human and swine CAD. Similar [Ca2+]i dysregulation exhibited in human and Ossabaw swine CSM provides strong evidence for the translational relevance of this large animal model.

Nursing Documentation Variation Across Different Medical Facilities Within an Integrated Healthcare System

The purpose of this study was to demonstrate nursing documentation variation based on electronic health record design and its relationship with different levels of care by reviewing how various flowsheet measures, within the same electronic health record across an integrated healthcare system, are documented in different types of medical facilities. Flowsheet data with information on patients who were admitted to academic medical centers, community hospitals, and rehabilitation centers were used to calculate the frequency of flowsheet entries documented. We then compared the distinct flowsheet measures documented in five flowsheet templates across the different facilities. We observed that each type of healthcare facility appeared to have distinct clinical care foci and flowsheet measures documented differed within the same template based on facility type. Designing flowsheets tailored to study settings can meet the needs of end users and increase documentation efficiency by reducing time spent on unrelated flowsheet measures. Furthermore, this process can save nurses time for direct patient care.

Biofabrication of a shape-stable auricular structure for the reconstruction of ear deformities

Bioengineering of the human auricle remains a significant challenge, where the complex and unique shape, the generation of high-quality neocartilage, and shape preservation are key factors. Future regenerative medicine–based approaches for auricular cartilage reconstruction will benefit from a smart combination of various strategies. Our approach to fabrication of an ear-shaped construct uses hybrid bioprinting techniques, a recently identified progenitor cell population, previously validated biomaterials, and a smart scaffold design. Specifically, we generated a 3D-printed polycaprolactone (PCL) scaffold via fused deposition modeling, photocrosslinked a human auricular cartilage progenitor cell–laden gelatin methacryloyl (gelMA) hydrogel within the scaffold, and cultured the bioengineered structure in vitro in chondrogenic media for 30 days. Our results show that the fabrication process maintains the viability and chondrogenic phenotype of the cells, that the compressive properties of the combined PCL and gelMA hybrid auricular constructs are similar to native auricular cartilage, and that biofabricated hybrid auricular structures exhibit excellent shape fidelity compared with the 3D digital model along with deposition of cartilage-like matrix in both peripheral and central areas of the auricular structure. Our strategy affords an anatomically enhanced auricular structure with appropriate mechanical properties, ensures adequate preservation of the auricular shape during a dynamic in vitro culture period, and enables chondrogenically potent progenitor cells to produce abundant cartilage-like matrix throughout the auricular construct. The combination of smart scaffold design with 3D bioprinting and cartilage progenitor cells holds promise for the development of clinically translatable regenerative medicine strategies for auricular reconstruction.

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First application of human auricular cartilage progenitor cells for bioprinting.

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Dual-printing of hybrid ear-shaped constructs with excellent shape fidelity over time.

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Strategy and design ensured adequate deposition of cartilage-like matrix throughout large auricular constructs.

Development and validation of early warning score system: A systematic literature review

OBJECTIVES

This review aims to: 1) evaluate the quality of model reporting, 2) provide an overview of methodology for developing and validating Early Warning Score Systems (EWSs) for adult patients in acute care settings, and 3) highlight the strengths and limitations of the methodologies, as well as identify future directions for EWS derivation and validation studies.

METHODOLOGY

A systematic search was conducted in PubMed, Cochrane Library, and CINAHL. Only peer reviewed articles and clinical guidelines regarding developing and validating EWSs for adult patients in acute care settings were included. 615 articles were extracted and reviewed by five of the authors. Selected studies were evaluated based on the Transparent Reporting of a multivariable prediction model for Individual Prognosis Or Diagnosis (TRIPOD) checklist. The studies were analyzed according to their study design, predictor selection, outcome measurement, methodology of modeling, and validation strategy.

RESULTS

A total of 29 articles were included in the final analysis. Twenty-six articles reported on the development and validation of a new EWS, while three reported on validation and model modification. Only eight studies met more than 75% of the items in the TRIPOD checklist. Three major techniques were utilized among the studies to inform their predictive algorithms: 1) clinical-consensus models (n = 6), 2) regression models (n = 15), and 3) tree models (n = 5). The number of predictors included in the EWSs varied from 3 to 72 with a median of seven. Twenty-eight models included vital signs, while 11 included lab data. Pulse oximetry, mental status, and other variables extracted from electronic health records (EHRs) were among other frequently used predictors. In-hospital mortality, unplanned transfer to the intensive care unit (ICU), and cardiac arrest were commonly used clinical outcomes. Twenty-eight studies conducted a form of model validation either within the study or against other widely-used EWSs. Only three studies validated their model using an external database separate from the derived database.

CONCLUSION

This literature review demonstrates that the characteristics of the cohort, predictors, and outcome selection, as well as the metrics for model validation, vary greatly across EWS studies. There is no consensus on the optimal strategy for developing such algorithms since data-driven models with acceptable predictive accuracy are often site-specific. A standardized checklist for clinical prediction model reporting exists, but few studies have included reporting aligned with it in their publications. Data-driven models are subjected to biases in the use of EHR data, thus it is particularly important to provide detailed study protocols and acknowledge, leverage, or reduce potential biases of the data used for EWS development to improve transparency and generalizability.

Mining clinical phrases from nursing notes to discover risk factors of patient deterioration

OBJECTIVE

Early identification and treatment of patient deterioration is crucial to improving clinical outcomes. To act, hospital rapid response (RR) teams often rely on nurses' clinical judgement typically documented narratively in the electronic health record (EHR). We developed a data-driven, unsupervised method to discover potential risk factors of RR events from nursing notes.

METHODS

We applied multiple natural language processing methods, including language modelling, word embeddings, and two phrase mining methods (TextRank and NC-Value), to identify quality phrases that represent clinical entities from unannotated nursing notes. TextRank was used to determine the important word-sequences in each note. NC-Value was then used to globally rank the locally-important sequences across the whole corpus. We evaluated our method both on its accuracy compared to human judgement and on the ability of the mined phrases to predict a clinical outcome, RR event hazard.

RESULTS

When applied to 61,740 hospital encounters with 1,067 RR events and 778,955 notes, our method achieved an average precision of 0.590 to 0.764 (when excluding numeric tokens). Time-dependent covariates Cox model using the phrases achieved a concordance index of 0.739. Clustering the phrases revealed clinical concepts significantly associated with RR event hazard.

DISCUSSION

Our findings demonstrate that our minimal-annotation, unsurprised method can rapidly mine quality phrases from a large amount of nursing notes, and these identified phrases are useful for downstream tasks, such as clinical outcome predication and risk factor identification.

Identifying nurses' concern concepts about patient deterioration using a standard nursing terminology

OBJECTIVES

Nurse concerns documented in nursing notes are important predictors of patient risk of deterioration. Using a standard nursing terminology and inputs from subject-matter experts (SMEs), we aimed to identify and define nurse concern concepts and terms about patient deterioration, which can be used to support subsequent automated tasks, such as natural language processing and risk predication.

METHODS

Group consensus meetings with nurse SMEs were held to identify nursing concerns by grading Clinical Care Classification (CCC) system concepts based on clinical knowledge. Next, a fundamental lexicon was built placing selected CCC concepts into a framework of entities and seed terms to extend CCC granularity.

RESULTS

A total of 29 CCC concepts were selected as reflecting nurse concerns. From these, 111 entities and 586 seed terms were generated into a fundamental lexicon. Nursing concern concepts differed across settings (intensive care units versus non-intensive care units) and unit types (medicine versus surgery units).

CONCLUSIONS

The CCC concepts were useful for representing nursing concern as they encompass a nursing-centric conceptual framework and are practical in lexicon construction. It enabled the codification of nursing concerns for deteriorating patients at a standardized conceptual level. The boundary of selected CCC concepts and lexicons were determined by the SMEs. The fundamental lexicon offers more granular terms that can be identified and processed in an automated fashion.

Unsupervised Machine Learning of Topics Documented by Nurses about Hospitalized Patients Prior to a Rapid-Response Event

BACKGROUND

In the hospital setting, it is crucial to identify patients at risk for deterioration before it fully develops, so providers can respond rapidly to reverse the deterioration. Rapid response (RR) activation criteria include a subjective component ("worried about the patient") that is often documented in nurses' notes and is hard to capture and quantify, hindering active screening for deteriorating patients.

OBJECTIVES

We used unsupervised machine learning to automatically discover RR event risk/protective factors from unstructured nursing notes.

METHODS

In this retrospective cohort study, we obtained nursing notes of hospitalized, nonintensive care unit patients, documented from 2015 through 2018 from Partners HealthCare databases. We applied topic modeling to those notes to reveal topics (clusters of associated words) documented by nurses. Two nursing experts named each topic with a representative Systematized Nomenclature of Medicine-Clinical Terms (SNOMED CT) concept. We used the concepts along with vital signs and demographics in a time-dependent covariates extended Cox model to identify risk/protective factors for RR event risk.

RESULTS

From a total of 776,849 notes of 45,299 patients, we generated 95 stable topics, of which 80 were mapped to 72 distinct SNOMED CT concepts. Compared with a model containing only demographics and vital signs, the latent topics improved the model's predictive ability from a concordance index of 0.657 to 0.720. Thirty topics were found significantly associated with RR event risk at a 0.05 level, and 11 remained significant after Bonferroni correction of the significance level to 6.94E-04, including physical examination (hazard ratio [HR] = 1.07, 95% confidence interval [CI], 1.03-1.12), informing doctor (HR = 1.05, 95% CI, 1.03-1.08), and seizure precautions (HR = 1.08, 95% CI, 1.04-1.12).

CONCLUSION

Unsupervised machine learning methods can automatically reveal interpretable and informative signals from free-text and may support early identification of patients at risk for RR events.

The Cardiovascular effects of chocolate

The antioxidants as polyphenols, especially flavanols present in cocoa, exert a favorable effect on endothelium vasodilation, modulate inflammatory markers, and decrease platelet aggregation, lipid oxidation and insulin resistance. Recent nutritional intervention trials and molecular studies demonstrate that consumption of cocoa, particularly rich in flavanols, is beneficial to promote cardiovascular health. This review describes the cardiovascular effects of chocolate.

Thrombosis of the Right Internal Jugular Vein is Not a Contraindication to Ambulatory Veno-Venous Extracorporeal Membrane Oxygenation with a Bicaval Dual-Lumen, Single Cannula System

Background: Veno-venous extracorporeal membrane oxygenation (VV-ECMO) is an ever-emerging method of managing respiratory failure in patients who are refractory to conventional mechanical ventilatory support. An increasingly common method of cannulation involves placement of a bicaval dual-lumen, single cannula via the right internal jugular (IJ) vein. Thrombus in this vein has been considered a contraindication for cannula placement. Case report: A 45-year-old Hispanic male presented with bleomycin-induced respiratory failure resulting in acute respiratory distress syndrome (ARDS). Ambulatory VV-ECMO support was initiated, and during surgical cannula placement an occlusive thrombus was noted in the right IJ vein. A tract was dilated and the cannula was placed without any thromboembolic complications.Conclusion: This case demonstrates that cannulation for ambulatory VV-ECMO in the setting of an occlusive IJ thrombus can be safe and feasible.

Predictive equations for lung volumes from computed tomography for size matching in pulmonary transplantation

OBJECTIVE

Size matching for lung transplantation is widely accomplished using height comparisons between donors and recipients. This gross approximation allows for wide variation in lung size and, potentially, size mismatch. Three-dimensional computed tomography (3D-CT) volumetry comparisons could offer more accurate size matching. Although recipient CT scans are universally available, donor CT scans are rarely performed. Therefore, predicted donor lung volumes could be used for comparison to measured recipient lung volumes, but no such predictive equations exist. We aimed to use 3D-CT volumetry measurements from a normal patient population to generate equations for predicted total lung volume (pTLV), predicted right lung volume (pRLV), and predicted left lung volume (pLLV), for size-matching purposes.

METHODS

Chest CT scans of 400 normal patients were retrospectively evaluated. 3D-CT volumetry was performed to measure total lung volume, right lung volume, and left lung volume of each patient, and predictive equations were generated. The fitted model was tested in a separate group of 100 patients. The model was externally validated by comparison of total lung volume with total lung capacity from pulmonary function tests in a subset of those patients.

RESULTS

Age, gender, height, and race were independent predictors of lung volume. In the test group, there were strong linear correlations between predicted and actual lung volumes measured by 3D-CT volumetry for pTLV (r = 0.72), pRLV (r = 0.72), and pLLV (r = 0.69). A strong linear correlation was also observed when comparing pTLV and total lung capacity (r = 0.82).

CONCLUSIONS

We successfully created a predictive model for pTLV, pRLV, and pLLV. These may serve as reference standards and predict donor lung volume for size matching in lung transplantation.

Venovenous extracorporeal membrane oxygenation as a bridge to lung transplantation: successful transplantation after 155 days of support

We present a case of a woman with acute respiratory distress syndrome and irrecoverable lung function that was successfully bridged to lung transplantation after 155 consecutive days of venovenous extracorporeal membrane oxygenation.

Prevention and treatment of Clostridium perfringens epsilon toxin intoxication in mice with a neutralizing monoclonal antibody (c4D7) produced in Nicotiana benthamiana

Epsilon toxin (ETX), produced by Clostridium perfringens types B and D, is among the most lethal toxins known. ETX is a potential bioterrorism threat that was listed as a Category B agent by the U.S. Centers for Disease Control until 2012 and it still remains a toxin of interest for several government agencies. We produced a monoclonal antibody (MAb) against ETX (ETX MAb c4D7) in Nicotiana benthamiana and characterized its preventive and therapeutic efficacy in mice. The ETX preparation used was highly lethal for mice (LD50 = 1.6 μg/kg) and resulted in a mean time from inoculation to death of 18 and 180 min when administered intravenously or intraperitoneally, respectively. High lethal challenge resulted in dramatic increases of a variety of pro-inflammatory cytokines in serum, while lower, but still lethal doses, did not elicit such responses. ETX MAb c4D7 was highly effective prophylactically (ED50 = 0.3 mg/kg; ED100 = 0.8 mg/kg) and also provided protection when delivered 15-30 min post-ETX intoxication. These data suggest that ETX MAb c4D7 may have use as a pre- and post-exposure treatment for ETX intoxication.

Comparative neuropathology of ovine enterotoxemia produced by Clostridium perfringens type D wild-type strain CN1020 and its genetically modified derivatives

Clostridium perfringens type D causes enterotoxemia in sheep and goats. The disease is mediated by epsilon toxin (ETX), which affects the cerebrovascular endothelium, increasing vascular permeability and leading to cerebral edema. In the present study, we compared the distribution and severity of the cerebrovascular changes induced in lambs by C. perfringens type D strain CN1020, its isogenic etx null mutant, and the ETX-producing complemented mutant. We also applied histochemical and immunohistochemical markers to further characterize the brain lesions induced by ETX. Both ETX-producing strains induced extensive cerebrovascular damage that did not differ significantly between each other in nature, neuroanatomic distribution, or severity. By contrast, lambs inoculated with the etx mutant or sterile, nontoxic culture medium did not develop detectable brain lesions, confirming that the neuropathologic effects observed in these infections are dependent on ETX production. Lambs treated with the wild-type and complemented strains showed perivascular and mural vascular edema, as well as serum albumin extravasation, particularly severe in the cerebral white matter, midbrain, medulla oblongata, and cerebellum. Brains of animals inoculated with the ETX-producing strains showed decreased expression of glial fibrillary acidic protein and increased expression of aquaporin-4 in the end-feet processes of the astrocytes around blood vessels. Early axonal injury was demonstrated with anti-amyloid precursor protein immunohistochemistry. Perivascular accumulation of macrophages/microglia with intracytoplasmic albumin globules was also observed in these animals. This study demonstrates that ETX is responsible for the major cerebrovascular changes in C. perfringens type D-induced disease.

Long-Term Outcomes following Alemtuzumab Induction in Lung Transplantation

Objectives: Alemtuzumab is a commonly used induction agent for solid-organ transplantation. Its use in lung transplantation with reduced immunosuppressive regimens, however, has yet to be well characterized.Methods: From November 2006 to March 2008, 20 consecutive lung transplantation patients received alemtuzumab induction with a reduced maintenance immunosuppression regimen. Twenty consecutive case-controls who underwent transplantation between 2005 and 2006 were treated with a standard immunosuppression regimen without induction. Outcome variables were patient survival, acute rejection, infection, and bronchiolitis obliterans syndrome.Results: Mean follow-up time was 1400 days in the alemtuzumab group and 1210 days in the control group. Double lung transplantation was performed in 21 patients (12 in the alemtuzumab group and 9 in the control group). There was no difference in survival between the alemtuzumab (n = 10) and control (n = 10) groups. There was also not a significant difference in time-adjusted death based on Kaplan-Meier analysis. The mean number of any grade of rejection event per patient was not significantly different (alemtuzumab 2.3 ± 2.7 vs. control 3.2 ± 2.35; P = .22). There was a trend toward the reduced incidence of infection requiring intravenous antibiotics per patient (alemtuzumab 2.4 vs. control 3.8; P = .08). The incidence of bronchiolitis obliterans syndrome was similar in both groups (alemtuzumab 55% vs. control 70%; P = .25).Conclusions: Alemtuzumab induction with reduced immunosuppression offers a comparable 5-year survival and rejection rate compared to standard-dose immunosuppression regimen.

Algorithm for total face and multiorgan procurement from a brain-dead donor

Procurement of a facial vascularized composite allograft (VCA) should allow concurrent procurement of all solid organs and ensure their integrity. Because full facial procurement is time-intensive, "simultaneous-start" procurement could entail VCA ischemia over 12 h. We procured a total face osteomyocutaneous VCA from a brain-dead donor. Bedside tracheostomy and facial mask impression were performed preoperative day 1. Solid organ recovery included heart, lungs, liver, kidneys, and pancreas. Facial dissection time was 12 h over 15 h to diminish ischemia while awaiting recipient preparation. Solid organ recovery began at 13.5 h, during midfacial osteotomies, and concluded immediately after facial explantation. Facial thoracic and abdominal teams worked concurrently. Estimated blood loss was 1300 mL, requiring five units of pRBC and two units FFP. Urine output, MAP, pH and PaO2 remained normal. All organs had good postoperative function. We propose an algorithm that allows "face first, concurrent completion" recovery of a complex facial VCA by planning multiple pathways to expedient recovery of vital organs in the event of clinical instability. Beginning the recipient operation earlier may reduce waiting time due to extensive recipient scarring causing difficult dissection.

The effect of Clostridium perfringens type C strain CN3685 and its isogenic beta toxin null mutant in goats

Clostridium perfringens type C is an important cause of enteritis and/or enterocolitis in several animal species, including pigs, sheep, goats, horses and humans. The disease is a classic enterotoxemia and the enteric lesions and associated systemic effects are thought to be caused primarily by beta toxin (CPB), one of two typing toxins produced by C. perfringens type C. This has been demonstrated recently by fulfilling molecular Koch's postulates in rabbits and mice. We present here an experimental study to fulfill these postulates in goats, a natural host of C. perfringens type C disease. Nine healthy male or female Anglo Nubian goat kids were inoculated with the virulent C. perfringens type C wild-type strain CN3685, an isogenic CPB null mutant or a strain where the cpb null mutation had been reversed. Three goats inoculated with the wild-type strain presented abdominal pain, hemorrhagic diarrhea, necrotizing enterocolitis, pulmonary edema, hydropericardium and death within 24h of inoculation. Two goats inoculated with the CPB null mutant and two goats inoculated with sterile culture media (negative controls) remained clinically healthy during 24h after inoculation and no gross or histological abnormalities were observed in the tissues of any of them. Reversal of the null mutation to partially restore CPB production also increased virulence; 2 goats inoculated with this reversed mutant presented clinical and pathological changes similar to those observed in goats inoculated with the wild-type strain, except that spontaneous death was not observed. These results indicate that CPB is required for C. perfringens type C to induce disease in goats, supporting a key role for this toxin in natural C. perfringens type C disease pathogenesis.

Ambulatory veno-venous extracorporeal membrane oxygenation: innovation and pitfalls

OBJECTIVE

End-stage lung disease and severe acute lung injury are complex entities that remain challenges to manage. Therapies include early institution of mechanical ventilation with positive end-expiratory pressure, permissive hypercapnia, pulmonary vasodilators, and complex fluid regimens. Veno-venous extracorporeal membrane oxygenation is an available treatment option for these patients but, in its conventional form, can be associated with significant complications. We present our early experience with an attempt to optimize extracorporeal membrane oxygenation, emphasizing reduced adjunctive mechanical ventilatory support and aggressive rehabilitation, with a goal of ambulation. This strategy has been enabled by the introduction of a dual-lumen draw and return cannula placed via the internal jugular vein.

METHODS

The first 10 patients (mean age of 45.3 years, 8 male) treated with this strategy between January 1, 2009, and October 1, 2009, were retrospectively reviewed. The ambulatory extracorporeal membrane oxygenation strategy was initiated with an aim of minimal mechanical ventilation and aggressive rehabilitation. The patients were intended to be weaned from all respiratory support or bridged to transplantation.

RESULTS

The mean duration of extracorporeal membrane oxygenation was 20 (9-59) days, with average mean blood flows of 3.5 (1.6-4.9) L/min, and levels of CO(2) removal and O(2) transfer of 228 (54-570) mL/min and 127 (36-529) mL/min, respectively. Six of 10 patients were weaned from respiratory support (N = 4) or underwent transplantation (N = 2) and survived to discharge from the hospital. The remaining 4 patients died of sepsis (N = 3) and withdrawal of care after renal failure (N = 1). Four of the 6 surviving patients were extubated and ambulatory while still on extracorporeal membrane oxygenation. During that time, 3 of the 4 patients exercised at the bedside, with the remaining patient able to undergo full cardiopulmonary rehabilitation, including treadmill walking.

CONCLUSIONS

Improvements in the durability of membrane blood oxygenators and pumps have prompted renewed consideration of extracorporeal membrane oxygenation in patients with severe lung disease. This report describes an attempt to augment extracorporeal membrane oxygenation with the goal of ambulation by minimizing mechanical ventilatory support and using aggressive in-and-out-of-bed rehabilitation.

Estimation of genetic parameters and variance components for growth traits in Romosinuano cattle in the Colombian humid tropics

(Co)variance components and genetic parameters were estimated for body weights of a Romosinuano herd located in Sinú Valley, Cordoba, Colombia. Restricted maximum likelihood methods were used with a univariate animal model for birth weight, weaning weight (270 days), 16-month weight (480 days), weaning daily gain, and post-weaning daily gain. Models included random animal direct and maternal genetic effects, maternal permanent environmental effect (c2), and sex-year-month of birth and age of dam, as fixed effects. Estimates of direct effect for birth weight, weaning weight, 480-day weight, weaning daily gain, and post-weaning daily gain were: 0.25 +/- 0.0001, 0.34 +/- 0.063, 0.33 +/- 0.066, 0.32 +/- 0.062, and 0.17 +/- 0.052, respectively. Estimates of direct maternal genetic effects were low and ranged from 0.06 +/- 0.003 for birth weight to 0.20 +/- 0.054 for weaning daily gain. The genetic correlations between direct and maternal genetic effects were negative and low for 480-day weight (-0.05 +/- 0.219) and showed values of -0.37 +/- 0.007, -0.34 +/- 0.133, -0.33 +/- 0.135, and -0.38 +/- 0.232 for birth, weaning weight, weaning, and post-weaning daily gain, respectively. Permanent environmental maternal effects were not significant; the highest values were found for weaning weight, and weaning daily gain (0.086 +/- 0.031 and 0.078 +/- 0.031, respectively). We conclude that direct and maternal effects should be included in a selection program for all of these traits, and also that selection of weaning weights would be the most productive way to improve performance in Romosinuano cattle.

Utility of Biopsy in Kidney Transplants With Delayed Graft Function and Acute Dysfunction

Renal biopsy is currently the gold standard to assess the causes of renal allograft dysfunction. In the present study, we prospectively assessed the role of the renal allograft biopsy in the diagnosis and treatment of renal allograft dysfunction. Seven hundred and fifteen biopsies were performed in 399 patients. The anatomopathological results in group 1 (delayed graft function) were: 60.4% acute tubular necrosis, 17.6% acute rejection, 4.3% calcineurin inhibitor toxicity, and 17.7% other diagnoses; in group 2 (acute graft dysfunction): 42.3% acute rejection, 22% acute tubular necrosis, 8.4% calcineurin inhibitor toxicity, and 27.3% other diagnoses. Among patients with delayed graft function, 42.2% of biopsies led to a change in the treatment. In 60.5%, the biopsy of patients with acute dysfunction led to a change in the patient management. In our series, the result of the biopsy disagreed with the clinical diagnosis in 39.6% and 57.7% of cases, respectively. These results demonstrated that renal graft biopsy remains an indispensable tool for the accurate management of kidney transplant patients.

Midwave-infrared snapshot imaging spectrometer

We report results from a demonstration of a midwave-infrared, nonscanning, high-speed imaging spectrometer capable of simultaneously recording spatial and spectral data from a rapidly varying target scene. We demonstrated high-speed spectral imaging by collecting spectral and spatial snapshots of blackbody targets and combustion products. The instrument is based on computed tomography concepts and operates in a midwave-infrared band of 3.0-5.0 mum. We record raw images at a frame rate of 60 frames/s, using a 512 x 512 InSb focal-plane array. Reconstructed object cube estimates were sampled at 46 x 46 x 21 (x, y, lambda) elements, or 0.1-mum spectral sampling. Reconstructions of several objects are presented.

Mixed-expectation image-reconstruction technique

An iterative method of reconstructing degraded images is developed from consideration of a mixed-noise imaging situation. Both photon noise in the image itself and postdetection Gaussian noise are combined by use of the standard maximum-likelihood method to produce a mixed-expectation reconstruction technique that demonstrates good performance in the presence of both noise sources. The new algorithm is evaluated through computer simulations.

High-speed spectral imager for imaging transient fluorescence phenomena

We describe fluorescence spectral imaging results with the microscope computed-tomography imaging spectrometer (muCTIS). This imaging spectrometer is capable of recording spatial and spectral data simultaneously. Consequently, muCTIS can be used to image dynamic phenomena. The results presented consist of proof-of-concept imaging results with static targets composed of 6-mum fluorescing microspheres. Image data were collected with integration times of 16 ms, comparable with video-frame-rate integration times. Conversion of raw data acquired by the muCTIS to spatial and spectral data requires postprocessing. The emission spectra were sampled at 10-nm intervals between 420 and 710 nm. The smallest spatial sampling interval presented is 1.7 mum.

Multimodality therapy for malignant pleural mesothelioma

Mesothelioma is a rare disease for which neither single modality nor bimodality therapy improves survival. For this reason, from 1980 to 1995, we used trimodality therapy in an attempt to improve survival in selected patients at Brigham and Women's Hospital and Dana-Farber Cancer Institute. One hundred twenty patients underwent trimodality treatment involving extrapleural pneumonectomy followed by combination chemoradiotherapy. Twenty-seven women and 93 men (mean age, 56 years) were evaluable for response and treatment-related morbidity. The operative mortality rate was 5%, and 22% of patients experienced major morbidity. Cell type and nodal status were significant prognostic variables. The respective 2- and 5-year survival rates were 45% and 22% overall, 70% and 37% for patients with epithelial cell type, 20% and 0% for patients with sarcomatous or mixed-histologic-type tumors, and 74% and 39% for patients who were node-negative with epithelial histologic type. Positive resection margins impacted survival only in the case of full-thickness, transdiaphragmatic invasion. A revised staging system stratified survival with median intervals of 22, 17, and 11 months for stages I, II, and III disease, respectively (p=0.04). Thus, extrapleural pneumonectomy with adjuvant therapy is appropriate and effective treatment for patients with stage I disease according to the revised staging system.

Nesidioblastosis in the adult surgical management

Nesidioblastosis is an exceedingly rare occurrence in the adult and, when it appears, it is usually part of a MEA1 syndrome. We present a case of nesidioblastosis in a young woman, with no concurrent endocrine pathology, while we discuss in detail the diagnostic and therapeutic problems posed by this condition. The selected treatment was sub-total pancreatectomy (70-80%) and the histopathologic and immunohistochemical tests of the surgical specimen showed: "Diffuse Nesidioblastosis". The histopathologic and immuno-histochemical features of the resected pancreas are analysed in detail.

Extrapleural pneumonectomy in the multimodality therapy of malignant pleural mesothelioma. Results in 120 consecutive patients

OBJECTIVE

The authors examine the feasibility and efficacy of trimodality therapy in the treatment of malignant pleural mesothelioma and identify prognostic factors.

BACKGROUND

Mesothelioma is a rare, uniformly fatal disease that has increased in incidence in recent decades. Single and bimodality therapies do not improve survival.

METHODS

From 1980 to 1995, 120 patients underwent treatment for pathologically confirmed malignant mesothelioma at Brigham and Women's Hospital and Dana-Farber Cancer Institute (Boston, MA). Initial patient evaluation was performed by a multimodality team. Patients meeting selection criteria and with resectable disease identified by computed tomography scan or magnetic resonance imaging underwent extrapleural pneumonectomy followed by combination chemotherapy and radiotherapy.

RESULTS

The cohort included 27 women and 93 men with a mean age of 56 years. Operative mortality rate was 5.0%, with a major morbidity rate of 22%. Overall survival rates were 45% at 2 years and 22% at 5 years. Two and 5-year survival rates were 65% and 27%, respectively, for patients with epithelial cell type, and 20% and 0%, respectively, for patients with sarcomatous or mixed histology tumors. Nodal involvement was a significant negative prognostic factor. Patients who were node negative with epithelial histology had 2- and 5-year survival rates of 74% and 39%, respectively. Involvement of margins at time of resection did not affect survival, except in the case of full-thickness, transdiaphragmatic invasion. Classification on the basis of a revised staging system stratified median survivals, which were 22, 17, and 11 months for stages I, II, and III, respectively (p = 0.04).

CONCLUSIONS

Extrapleural pneumonectomy with adjuvant therapy is appropriate treatment for selected patients with malignant mesothelioma selected using a revised staging system.

Elbow anchylosis due to postburn heterotopic ossification

In a retrospective study performed on 2280 patients that had had major thermal injuries, six patients experienced elbow anchylosis due to heterotopic ossification (two of them bilaterally). In every patient the ossification was localized at the posterior-medial aspect of the elbow. The treatment of this complication consisted of resection of the bone mass and transposition of the ulnar nerve. Mobilization was begun early, and rehabilitation was kept up for at least 4 months. The results obtained have been evaluated following the criteria of Merle d'Aubigné and Cañadell, who consider a very good result a gain of more than 60% in the arch of flexion-extension of the elbow; good, between 40% and 60%; fair between 20% and 40%; and poor, a gain of less than 20%. In five of the patients (six elbows), the result was very good with an average gain of 73.6% (minimum, 61.5%, maximum, 84.6%). In one patient the result was poor with gain of less than 20%. The incidence of this complication, its treatment, and the results obtained are analyzed.

[Pheochromocytoma]

The authors present the case of a 51 year old woman with severe arterial hypertension with parixisms, without medical control. The clinical, laboratory and imagiological investigation showed a pheochromocytoma at the right adrenal gland. The patient was submitted to surgery with success. Specific aspects of differential diagnosis are discussed and a review of the more relevant features of clinical diagnosis, pre-operative preparation and surgical technique are presented.

[Intraoperative echography in biliary tract surgery. A comparative study of intraoperative echography/cholangiography in the detection of calculi in the common bile duct]

We report 3 years of experience with operative ultrasonography on 200 patients who underwent cholecystectomy for biliary lithiasis. Intraoperative ultrasonography and intraoperative cholangiography were performed on all of these patients and compared with the operative findings. The diagnostic accuracy of sonography was 98% and that of cholangiography 96% in the whole patient group. The predictive value of a positive ultrasonography was 92.5% while that of a positive cholangiogram was lower at 81.5%. In 32 patients who underwent surgical exploration of the common duct the use of these two intraoperative screening tests together led to a positive common duct exploration in 75% of the patients. Overall morbidity in this series was 4.8% against 12.8% (common duct exploration) and retained stones following duct exploration were present in 1 patient in intra-hepatic situation. The overall mortality rate of the entire patient group was 0%. Operative ultrasonography of the biliary tract as a screening procedure is a reliable method, a possible substitute for operative cholangiography, but perhaps in reality both methods are complementary.

Metabolic correlates of myocardial stunning and the effect of cardiopulmonary bypass

In order to study the metabolic consequences of myocardial stunning, repeated coronary occlusions were performed in dogs. The production of CO2, adenosine triphosphate (ATP), phosphocreatine (PCr), and inorganic phosphate (Pi) by myocardial cells was assessed, along with extracellular and intracellular pH. Our results indicate that regional coronary artery occlusion reduces the ability of the myocardium to produce H+ and CO2 and to replenish ATP post ischemia. These alterations, then, represent the hallmark of metabolic viability during periods of ischemic insult. Decreases in PCr and Pi were completely eliminated during reperfusion and, therefore, are ot reflective of myocardial stunning. When normothermic cardiopulmonary bypass (CPB) is instituted and the coronary artery is occluded three times with reperfusion between each occlusion, alterations in myocardial H+ and high energy phosphates are identical to those observed using only repetitive coronary occlusion. Systemic hypothermia during CPB does not protect against myocardial stunning; however, it is anticipated that interventions that prevent the reduction in H+ and ATP levels may overcome the effects of myocardial stunning that occur during cardiac surgery.

Management and epidemiologic analyses of an outbreak due to methicillin-resistant Staphylococcus aureus

PURPOSE

Following implementation of special measures to control a nosocomial outbreak of methicillin-resistant Staphylococcus aureus (MRSA), we used immunoblot typing in conjunction with antimicrobial susceptibility testing to investigate the epidemiology of this event and to determine whether this outbreak represented the failure of infection control measures to limit the spread of previously endemic MRSA strains or the introduction of a new strain of MRSA.

MATERIALS AND METHODS

Isolates of MRSA recovered from hospitalized patients were initially categorized on the basis of antimicrobial susceptibility results. Organisms susceptible to ciprofloxacin and/or trimethoprim/sulfamethoxazole were recovered from patients at a relatively constant rate prior to December 1988 and were categorized as endemic isolates. Subsequently, there was an outbreak due to organisms resistant to both of these antibiotics; these were therefore categorized as outbreak isolates. Isolates were later characterized by immunoblot typing. Prior to this analysis, isolates were given code numbers so that clinical and epidemiologic data as well as resistance patterns were not known until this testing was complete.

RESULTS

Between January 1986 and November 1988, an average of 3.9 patients per month acquired nosocomial MRSA in the Sepulveda Veterans Administration Medical Center. In contrast, from December 1988 to October 1989, 369 MRSA isolates were collected from 125 patients (an average of 11.4 patients per month). Prior to December 1988, all tested nosocomial isolates of MRSA were susceptible to ciprofloxacin and/or to trimethoprim/sulfamethoxazole. In contrast, the outbreak was due to spread of MRSA isolates resistant to these antibiotics. Immunoblot typing of 204 isolates from 98 individuals identified five distinct immunoblot types of which types B and C were by far the most common. Type B was highly associated with outbreak isolates, whereas type C was associated with endemic isolates (p less than 0.001). All sequential isolates from single patients that belonged to different susceptibility categories demonstrated discordant immunoblot types. In contrast, concordant immunoblot types were observed for 25 of 27 sequential isolates that displayed minor variations in antimicrobial resistance. The institution of more stringent infection control measures was followed by the return of nosocomial MRSA acquisition rates to pre-outbreak levels. Although novobiocin and trimethoprim/sulfamethoxazole were extensively used to treat patients harboring outbreak and endemic isolates, respectively, in no instance was the initial MRSA isolate from any patient resistant to novobiocin and only 6% of initial endemic isolates displayed trimethoprim/sulfamethoxazole resistance. A modest, significant increase in the resistance of endemic isolates to various other antimicrobial agents was noted however.

CONCLUSION

Immunoblot analyses provided strong, corroborative evidence that at least two separate strains of MRSA were present during the outbreak and that a newly introduced strain with a distinctive antimicrobial resistance pattern was primarily responsible for the rapid spread of MRSA during the outbreak. The observation that previously effective infection control measures failed to prevent the nosocomial spread of a newly introduced community-acquired MRSA strain suggests that a single set of control measures may not be equally efficacious against all strains of MRSA. In this regard, previously reported variations in resistance to topical antimicrobials and/or antiseptics, and differences in virulence factors such as colonization potential, invasiveness, and survival on fomites, may warrant further study. Control of the outbreak strain of MRSA in our institution did occur after the implementation of more strenuous isolation procedures.(ABSTRACT TRUNCATED)

Extrinsic silicon photodetector characterization

A gallium doped silicon (Si:Ga) extrinsic photoconductive detector was tested for sensitivity and quickness of response. The developmental goal for this detector material was high speed operation without compromised detectivity (D*). The high speed, p-type infrared photoconductor, with photoconductive gain less than unity, was tested at 10.5 microm to determine an experimental value for the detectivity-bandwidth product of D*f* = 3.69 x 10(18)cm-Hz(3/2)/W. Subsequently a theoretical model taking into account the optical absorption profile and majority-carrier-transport processes within the detector was developed. It agreed with experimental data and corroborated the theory.

An accurate method to obtain urine for culture in men with external catheters

Results of urine cultures from 26 male nursing home patients wearing external catheters, collected by a simple standardized technique, were compared with culture results from the same patients obtained by sterile in-and-out catheterization. The culture results were the same in 22 (85%) of the matched specimens, and specimens collected by the standardized technique were 100% sensitive and 94% specific in detecting significant growth of pathogenic organisms. In contrast, 13 (57%) of 23 specimens collected from patients with external catheters by the nursing home staff using their routine technique yielded three or more organisms and were considered contaminated. These results suggest that it is possible to obtain a urine specimen that reflects bladder urine in the vast majority of patients with external catheters, and thus potentially avoid the need for in-and-out catheterization when diagnosing and planning treatment for urinary tract infections in this population.