Subpopulation targeting of pyruvate dehydrogenase and GLUT1 decouples metabolic heterogeneity during collective cancer cell invasion.

Phenotypic heterogeneity exists within collectively invading packs of tumor cells, suggesting that cellular subtypes cooperate to drive invasion and metastasis. Here, we take a chemical biology approach to probe cell:cell cooperation within the collective invasion pack. These data reveal metabolic heterogeneity within invasive chains, in which leader cells preferentially utilize mitochondrial respiration and trailing follower cells rely on elevated glucose uptake. We define a pyruvate dehydrogenase (PDH) dependency in leader cells that can be therapeutically exploited with the mitochondria-targeting compound alexidine dihydrochloride. In contrast, follower cells highly express glucose transporter 1 (GLUT1), which sustains an elevated level of glucose uptake required to maintain proliferation. Co-targeting of both leader and follower cells with PDH and GLUT1 inhibitors, respectively, inhibits cell growth and collective invasion. Taken together, our work reveals metabolic heterogeneity within the lung cancer collective invasion pack and provides rationale for co-targeting PDH and GLUT1 to inhibit collective invasion.

Rapidly expanding nuclear arsenals in Pakistan and India portend regional and global catastrophe.

Pakistan and India may have 400 to 500 nuclear weapons by 2025 with yields from tested 12- to 45-kt values to a few hundred kilotons. If India uses 100 strategic weapons to attack urban centers and Pakistan uses 150, fatalities could reach 50 to 125 million people, and nuclear-ignited fires could release 16 to 36 Tg of black carbon in smoke, depending on yield. The smoke will rise into the upper troposphere, be self-lofted into the stratosphere, and spread globally within weeks. Surface sunlight will decline by 20 to 35%, cooling the global surface by 2° to 5°C and reducing precipitation by 15 to 30%, with larger regional impacts. Recovery takes more than 10 years. Net primary productivity declines 15 to 30% on land and 5 to 15% in oceans threatening mass starvation and additional worldwide collateral fatalities.

Development and Usability Assessment of a Connected Resistance Exercise Band Application for Strength-Monitoring.

Resistance exercise bands are a core component of any physical activity strengthening program. Strength training can mitigate the development of sarcopenia, the loss of muscle mass or strength and function with aging. Yet, the adherence of such behavioral exercise strategies in a home-based setting are fraught with issues of monitoring and compliance. Our group developed a Bluetooth-enabled resistance exercise band capable of transmitting data to an open-source platform. In this work, we developed an application to capture this information in real-time, and conducted three usability studies in two mixed-aged groups of participants (n=6 each) and a group of older adults with obesity participating in a weight-loss intervention (n=20). The system was favorable, acceptable and provided iterative information that could assist in future deployment on ubiquitous platforms. Our formative work provides the foundation to deliver home-based monitoring interventions in a high-risk, older adult population.

Relation of coronary artery stenosis and pressure gradient to exercise-induced ischemia before and after coronary angioplasty.

The purpose of this investigation was to evaluate the relation of coronary artery stenosis and associated pressure gradient to the magnitude of exercise-induced left ventricular dysfunction in patients with single vessel coronary artery disease. The percent stenosis and minimal cross-sectional area were measured before and after percutaneous transluminal coronary angioplasty and compared with radionuclide measurements of left ventricular function before and after angioplasty in 41 patients with proximal left anterior descending coronary artery lesions, providing 82 points of comparison. The gradient could be measured for 75 comparisons. Forty stenoses less than 50% were associated with a mean left ventricular exercise ejection fraction of 0.66 +/- 0.08 (mean +/- SD), 25 stenoses from 50 to 75% with a mean ejection fraction of 0.59 +/- 0.12 and 17 stenoses greater than 75% with a mean ejection fraction of 0.49 +/- 0.08. Thirty-five stenoses with a gradient less than 20 mm Hg were associated with a mean ejection fraction of 0.65 +/- 0.09, 24 with a gradient from 20 to 50 mm Hg with a mean ejection fraction of 0.58 +/- 0.13 and 16 with a gradient greater than 50 mm Hg with a mean ejection fraction of 0.53 +/- 0.10. These data document a relation between the magnitude of coronary artery stenosis and associated gradient to exercise-induced left ventricular dysfunction in homogeneous patient groups. However, discordance of these variables occurs commonly in individual patients.

Use of denaturing HPLC to map human and murine genes and to validate single-nucleotide polymorphisms.

Linkage mapping has been extensively applied in the murine and human genomes. It remains a powerful approach to mapping genes and identifying genetic variants. As genome efforts identify large numbers of single-nucleotide polymorphisms, it will be critical to validate these polymorphisms and confirm their gene assignment and chromosomal location. The presence of pseudogenes can confuse such efforts. We have used denaturing HPLC to identify polymorphisms in human genes and to genotype individuals in selected CEPH pedigrees. The same approach has been applied to the mapping of murine genes in interspecies backcross animals. This strategy is rapid, accurate and superior in several respects to other technologies.

An improved method of intralamellar keratoplasty in rats.

Intralamellar keratoplasty in inbred rats is a valuable method for the investigation of corneal allograft rejection. Present methods of intralamellar corneal grafting are tedious and time-consuming. In addition, induction of neovascularization, a prerequisite to inducing graft rejection, is variable. In an effort to overcome these problems, the authors have developed an improved method of intralamellar keratoplasty. Intralamellar pockets are formed by introducing a 30-g needle into the corneal stroma near the limbus. Approximately 10-25 microliters of lipopolysaccharide (LPS) (100 micrograms/ml) is injected into the stroma, forming a stromal bleb. This bleb is incised to form a pocket, resulting in the leakage of the injected liquid. The intralamellar pocket formation is completed by dissecting any remaining stromal fibers in the area of former bleb. Once the pocket has been formed, grafts of corneal tissue are inserted, and the incision is closed. This method of keratoplasty has the following advantages over previously reported methods: (1) It is more rapid and less tedious because the formation of the corneal bleb protects the anterior chamber from being invaded during the corneal incision; (2) It leads to a reproducible induction of neovascularization in every cornea so treated; (3) It results in a higher frequency of allograft rejection.

Comparison of cardiac function in surgically corrected and congenitally corrected transposition of the great arteries.

The capacity of the anatomic right ventricle to sustain normal function against systemic pressure long after atrial baffle procedures in patients with complete transposition of the great arteries remains unknown. Pulmonary and systemic ventricular function was measured by first-pass radionuclide studies in 11 children 7 +/- 3 years (+/- standard deviation) after baffle procedures. For comparison, similar measurements were made in eight patients with isolated congenitally corrected transposition of the great arteries and in 10 children in a control group. Exercise increased heart rate and cardiac index to similar levels in all three groups. Ventricular volumes were greater than control volumes in both groups with congenital heart disease. Exercise increased pulmonary ventricular ejection fraction in the control and congenitally corrected groups, but not in the surgically corrected group. Systemic ventricular ejection fraction increased during exercise in the control group, but remained unchanged in both transposition groups. These results show that cardiac index during exercise is maintained in patients after baffle procedures for complete transposition of the great arteries. However, pulmonary and systemic ventricular ejection fractions fail to increase with exercise, and ventricular volumes are markedly greater than normal.

Physiological rationale for a bidirectional cavopulmonary shunt. A versatile complement to the Fontan principle.

The original Fontan procedure included a classic superior vena cava-to-right pulmonary artery (Glenn) shunt. Subsequent experience demonstrated that this anastomosis was not essential and was an unnecessary commitment of the larger right pulmonary circulation to the smaller blood volume of the superior vena caval return. With application of the Fontan principle to more complex cardiac malformations, there has been a reconsideration of possible benefits of a cavopulmonary shunt in selected patients. A modified shunt from the divided end of the superior vena cava to the side of the undivided right pulmonary artery utilized in 21 patients is described. This shunt is designed to allow bidirectional pulmonary arterial distribution of both superior vena caval inflow and right atrial outflow after completion of the Fontan procedure. Twelve patients had the bidirectional shunt performed prior to a Fontan operation; five of these had a subsequent atriopulmonary connection and seven await operation. Eight patients had construction of this shunt at the time of their Fontan procedure. One patient had a bidirectional shunt constructed following atriopulmonary anastomosis to help relieve right atrial outflow obstruction. Two patients with univentricular heart undergoing simultaneous Fontan procedure and a bidirectional shunt died while in the hospital. The remaining 19 patients have been followed up for 2 months to 9 years with one late sudden death at 9 years. There have been no bidirectional cavopulmonary shunt failures, stenoses, kinks, or recognized pulmonary arteriovenous malformations. Postoperatively, eight patients had assessment of pulmonary distribution of shunt blood flow by angiography. Seven of these patients were also evaluated by radionuclide angiography. Superior vena caval blood flow via the bidirectional cavopulmonary shunt tended to be greater to the right lung, but bilateral pulmonary flow was documented in all but one patient. After Fontan operation, six of seven patients tested also demonstrated bilateral distribution of atriopulmonary flow. We concluded from our experience that this modified shunt provides excellent relief of cyanosis, allows bidirectional pulmonary distribution of both superior vena caval return and also the right atrial blood flow after atriopulmonary connection, and may be done before, with, or after a Fontan procedure and is compatible with all currently recommended modifications. Perioperative hemodynamic adjustments to the Fontan procedure may be improved by reducing atrial volume, and this may also be of potential benefit in the long-term adaptation to Fontan physiology by minimizing atrial distention.

Noninvasive assessment of exercise cardiac function before and after pectus excavatum repair.

Surgical correction of pectus excavatum frequently results in subjective improvement of exercise tolerance. Whether or not cardiac function improves after repair remains controversial and has primarily been limited to isolated case reports. The purpose of this investigation was to assess changes in cardiac function during rest and exercise associated with the surgical correction of this deformity. First-pass radionuclide studies during upright rest and bicycle exercise were performed on 13 patients before and at least 6 months after pectus excavatum repair. Operation did not change left ventricular ejection fraction or cardiac index at rest or during exercise. However, the left ventricular end-diastolic volume index and stroke volume index increased at rest after surgical correction. The estimated resting right ventricular end-diastolic volume also increased markedly after operation and was associated with a decrease in right ventricular ejection fraction. These data show no limitation in exercise cardiac function that could be relieved by pectus repair. However, the increase in right and left ventricular volume after operation suggests that some cardiac compression is relieved by operative repair.

Noninvasive determination of exercise cardiac function following Fontan operation.

The purpose of this investigation was to define mechanisms which increase cardiac output during exercise in patients without a functioning right ventricle. Radionuclide studies were performed at rest and during upright bicycle exercise on 16 patients following Fontan procedures and compared to studies in 10 normal children. The mean cardiac index of patients following Fontan procedures was 5.2 +/- 2.0 L/min/m2 (standard deviation) at rest and increased to 9.4 +/- 3.5 L/min/m2 during exercise (p less than 0.0001). Exercise values were similar to those observed in normal children. The mechanisms utilized to achieve high cardiac output following Fontan procedures included an increase in heart rate. Mean systemic ventricular ejection fractions were significantly less than in normal children. The resting ventricular end-diastolic volume and stroke volume indices were above normal and remained constant during exercise to high heart rates. These data clearly document that a large exercise cardiac output can be achieved by patients without a functioning right ventricle.

Pediatric and adult thoracic trauma: age-related impact on presentation and outcome.

UNLABELLED: To assess the impact of age on presentation and outcome, 2,415 cases involving blunt and penetrating thoracic trauma over an 8-year period were reviewed retrospectively from a single level I trauma center. Of the 2,073 patients alive on arrival, 79 were 12 years of age or less (children), 137 were 13 to 17 years of age (adolescent), 1,742 were 18 to 59 years of age (adults), and 115 were 60 years of age or more (elderly). Chi-square analysis was performed relative to presentation (blunt versus penetrating), need for thoracotomy, and hospital mortality. Although blunt thoracic trauma comprised 64/79 of children (81%) and 90/115 of the elderly (78%), penetrating thoracic trauma was more common for adolescents 79/137 (58%) and adults 1013/1742 (58%) (p < 0.05). There was no significant difference in need for thoracotomy among the four age groups after blunt thoracic trauma. For penetrating trauma, however, there was a significantly higher incidence of thoracotomy in children as compared with the other three age groups (p < 0.05). IN CONCLUSION: (1) Blunt injuries comprised a greater proportion of thoracic trauma in children and the elderly. (2) In this series, children with penetrating thoracic trauma underwent thoracotomy more frequently. (3) Hospital mortality appeared to be increased for the elderly. (4) Analyses of pediatric thoracic trauma must separate children from adolescent age groups.

Ultra-fast track hospital discharge using conventional cardiac surgical techniques.

BACKGROUND: Recent introduction of minimally invasive adult cardiac surgical techniques has emphasized the advantage of early hospital discharge. However, we chose an alternative approach to determine the safety, efficacy, and feasibility of ultra-fast track protocols while retaining both standard surgical exposure (median sternotomy) and conventional cardiac surgical techniques (hypothermia, cardiopulmonary bypass with cardiac arrest, and optimal myocardial protection). METHODS: From September 1995 to January 1998, a total of 258 consecutive patients underwent cardiac procedures by a single surgeon. Acceleration of clinical pathways was used to initiate earlier discharges. Stringent postdischarge follow-up was implemented. Prospectively entered data were then analyzed retrospectively. RESULTS: A variety of isolated as well as combined coronary and valve procedures were performed. Of the 258 patients operated on during this entire study period, a total of 144 patients (56%) were discharged within postoperative days 1 to 4 (ultra-fast track discharge). Over the past 12 months, this incidence increased to 70% (76 of 108 patients). Approximately 50% of these patients were operated on urgently or emergently. To date, there have been no deaths in this ultra-fast track group. There were eight brief readmissions, of which one was for rewiring of a noninfected sternal dehiscence, and the remaining were for cardiac diagnostic studies or a noncardiac problem altogether. CONCLUSIONS: Conventional cardiac operation can allow ultrafast hospital discharges while retaining the advantage of time-tested techniques and providing wider application without requiring new or additional training or equipment.

A rapid sensitive radioimmunoassay for rhodopsin: development and application.

Antisera have been raised against unbleached chromatographically pure bovine rhodopsin. A rapid sensitive radioimmunoassay (RIA) has been developed for rhodopsin, employing [125I]rhodopsin labeled using the Bolton-Hunter reagent. Protein A-bearing Staphylococcus aureus cells are used to precipitate the immune complex. Subpicomolar amounts of rhodopsin can be determined when the RIA is performed in the dark using any of nine different detergents tested. When the RIA is performed using bleached rhodopsin, the results are dependent upon the detergent in which the assay is performed. Bleached rhodopsin is most immunologically similar to unbleached rhodopsin in the mildest detergents and less similar in harsher detergents. One and a half times more bleached rhodopsin is required to compete to the same extent as unbleached rhodopsin when the RIA is performed in digitonin. Results for other detergents are: sucrose monoester, 5.0; CHAPS, 64; sodium cholate, 91; octylglucoside, 250; Triton X-100, 430; Emulphogene, 570; Ammonyx LO approximately 14,000; CTAB, unmeasureable. Other species of rhodopsin were tested as competitive in the RIA. Pig rhodopsin is 1/100th as effective a competitor as bovine rhodopsin, rat 1/200th, and frog 1/800th.

The relationship of alpha1-antitrypsin to inflammatory periodontal disease.

Alpha1-antitrypsin (alpha1-AT) is a serum protease inhibitor with a well established role in bodily defense against destructive inflammatory diseases. alpha1-AT exhibits inheritable genetic polymorphism (Pi types). Certain Pi types have been shown to predispose to emphysema and, in this study, also appear to be related to increased chronic periodontitis susceptibility.