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Local gene delivery represents a promising therapeutic approach for diseases of the intestine. However, the gastrointestinal tract poses significant challenges to successful gene delivery. Cyclodextrins (CDs) have been extensively investigated as non-viral vectors. Here, we assessed the suitability of an amphiphilic cationic CD for intestinal gene transfer, with particular focus on extracellular barriers. Stability and transfection efficiency of CD·DNA complexes were assessed post incubation in simulated gastric and intestinal fluids, bile salts and mucin, or with intestinal enzymes to represent extracellular barriers to intestinal gene delivery. Stability was determined by gel electrophoresis and transfection was measured by luciferase expression in intestinal epithelial cells (Caco-2). Transfection efficiency of CD·DNA complexes was enhanced after incubation in bile salts but was reduced after incubation in gastric and intestinal fluids and mucin. CD·DNA complexes were stable after incubation with pancreatic enzymes and with a model lower intestinal enzyme. Furthermore, the CD protected pDNA from degradation by DNase. In summary, physiologically relevant in vitro models were established and used to quantify the barriers posed by the intestinal extracellular environment to gene delivery. This systematic assessment identified the advantages and limitations of the CD vector and facilitated the proposal of formulation strategies to overcome these barriers.

Considerable research is focused on the development of non-viral vectors for gene and RNA interference therapies, with significant advancements in this field over the past number of years. Cationic lipids and polymers have been extensively investigated for these purposes, but there still remains a need for alternative vectors. Cyclodextrins (CDs) are cyclic oligosaccharides derived from starch and are well characterised pharmaceutical excipients. They offer many advantages as potential non-viral vectors for gene and siRNA delivery, in particular the ease with which they can be chemically modified and their limited toxicity. In recent years, there has been a surge in the number of publications concerning CDs in this field. In this paper, we will review the two main approaches to the use of CDs for gene and siRNA delivery. In the first instance, CDs are used as a scaffold, to which various chemical groups can be grafted, yielding monodisperse functionalised CDs which can self-assemble in the presence of oligonucleotides. CDs are particularly amenable to chemical modification and this approach enables specific and precise design of CD vectors for targeting to various cell and tissue types. In the second approach, CDs can be included as a component of a delivery system, for example, as part of a polymer backbone, appended to a dendrimeric vector, or in polyrotaxane systems. Here, the inclusion of CDs facilitates post-modification of the vector through the formation of inclusion complexes with adamantane and, in some instances, reduces toxicity of the vector. Lastly, we will consider the development of in vivo CD vectors for therapeutic use and other novel applications including siRNA delivery in neurons and the CNS.

Inflammatory bowel disease (IBD) is a chronic relapsing inflammation of the gastrointestinal tract. The cytokine TNF-alpha (TNF-α) plays a pivotal role in mediating this inflammatory response. RNA interference (RNAi) holds great promise for the specific and selective silencing of aberrantly expressed genes, such as TNF-α in IBD. The aim of this study was to investigate the efficacy of an amphiphilic cationic cyclodextrin (CD) vector for effective TNF-α siRNA delivery to macrophage cells and to mice with induced acute-colitis. The stability of CD.siRNA was examined by gel electrophoresis in biorelevant media reflecting colonic fluids. RAW264.7 cells were transfected with CD.TNF-α siRNA, stimulated with lipopolysaccharide (LPS) and TNF-α and IL-6 responses were measured by PCR and ELISA. Female C57BL/6 mice were exposed to dextran sodium sulphate (DSS) and treated by intrarectal administration with either CD.siRNA TNF-α or a control solution. In vitro, siRNA in CD nanocomplexes remained intact and stable in both fed and fasted simulated colonic fluids. RAW264.7 cells transfected with CD.TNF-α siRNA and stimulated with LPS displayed a significant reduction in both gene and protein levels of TNF-α and IL-6. CD.TNF-α siRNA-treated mice revealed a mild amelioration in clinical signs of colitis, but significant reductions in total colon weight and colonic mRNA expression of TNF-α and IL-6 compared to DSS-control mice were detected. This data indicates the clinical potential of a local CD-based TNF-α siRNA delivery system for the treatment of IBD.

[Objectives]: Achieving targeted delivery of gene medicines is desirable to maximise activity. Here, galactosylated amphiphilic cyclodextrins (CDs) are examined in terms of their ability to transfect asialoglycoprotein receptor-bearing HepG2 cells. [Methods]: Cationic amphiphilic CDs were synthesised as well as amphiphilic CDs bearing galactose-targeting ligands with different linker lengths. Binding of galactosylated CDs to a galactose-specific lectin was examined by surface plasmon resonance. CDs were formulated with and without the helper lipid DOPE and complexed with plasmid DNA. Transfection was evaluated by luciferase assay. Intracellular trafficking was assessed by confocal microscopy. [Key findings]: Binding of targeted CDs to a galactose-specific lectin was achieved. Binding decreased with linker length between the galactosyl group and the CD core. Contrary to the lectin binding results, transfection levels increased with an increase in linker length from 7 atoms to 15. Compared to non-targeted formulations, a significant increase in transfection was observed only in the presence of the helper lipid DOPE. Confocal microscopy revealed that DOPE caused a pronounced effect on cellular distribution. [Conclusions]: The galactose-targeting ligand induced substantial increases in transfection over non-targeted formulations when DOPE was included, indicating the potential for targeted gene delivery using CD-based delivery systems. © 2012 Royal Pharmaceutical Society.

The future of nucleic acid-based therapeutics is dependent on achieving successful delivery. Recently, there has been an increasing interest in delivery via the gastrointestinal tract. Gene therapy via this route has many advantages, including non-invasive access and the versatility to treat local diseases, such as inflammatory bowel disease, as well as systemic diseases, such as haemophilia. However, the intestine presents several distinct barriers and, therefore, the design of robust non-viral delivery systems is key to future success. Several non-viral delivery strategies have provided evidence of activity in vivo. To facilitate the design of more efficient and safe gene medicines, more physiologically relevant models, at both the in vitro and in vivo levels, are essential.

We have developed a simple method of predicting aortic valve prosthesis size from supravalvular aortic cineangiograms, taken in the 30 degree right anterior oblique projection, during routine diagnostic cardiac catheterization. Measurements made on the aortogram were corrected to true size by means of a 1 cm2 grid reference plate filmed at the conclusion of the catheterization. This method was utilized prospectively to predict the anulus size in 26 patients undergoing aortic valve replacement alone or as part of a more extensive cardiac procedure. The catheterization prediction of anulus size was perfectly predictive of the prosthesis size used in eight of 26 (31%) cases, within 1 mm of the prosthesis size used in 20 of 26 (77%), and within one prosthesis size in all 26 (100%) cases. Comparing the measured anulus diameter to the actual prosthesis diameter yielded r = 0.93. When both systolic and diastolic frames were available for analysis, the diastolic frame was more accurately predictive than the systolic frame (diastolic r = 0.93; systolic r = 0.88), although both yielded acceptable results. Utilization of this method has significantly altered operative plans in four patients with a small anulus. Such preoperative assessment should allow improved matching of patient and valve prosthesis and thereby yield improved long-term results in aortic valve replacement.

Right ventricular failure is an infrequent but potentially lethal complication of cardiac surgical procedures. We have successfully treated a patient with right ventricular failure with the use of a right ventricular assist pump (RVAP). This patient had aortic stenosis and coronary artery disease involving the circumflex and right coronary arteries. He also had chronic obstructive pulmonary disease with mild pulmonary hypertension (mean pulmonary artery pressure of 26 mm Hg) and evidence of mild right ventricular failure (right ventricular pressure of 40/14 mm Hg). Gated radionuclide angiography, performed preoperatively, showed that the right ventricle had normal wall motion. Right ventricular failure prevented discontinuation of cardiopulmonary bypass despite use of an intra-aortic balloon pump. The right atrial pressure was 20 mm Hg with a left atrial pressure of 8 to 10 mm Hg. Bypass was readily discontinued following implantation of the RVAP. Recovery of the patient's right ventricle was evaluated with serial determinations of right ventricular work. The RVAP was removed on the fifth postoperative day and the patient made a complete recovery. Postoperatively, gated radionuclide angiography demonstrated moderate recovery of right ventricular function. We suspect that the perioperative right ventricular failure was a result of unsatisfactory myocardial protection due to total occlusion of the proximal right coronary artery, which resulted in a maldistribution of the cardioplegic solution. This case demonstrates that right ventricular function can be restored following circulatory support with a mechanical assist device.

One hundred eighteen patients with lung cancer were retrospectively analyzed to determine whether postoperative radiotherapy (RT) improves survival. Patterns of treatment failure and three year NED (no evidence of disease) survival rates were assessed according to extent of tumor spread, histology, and treatment method. Patients with hilar or mediastinal node metastases were at higher risk of local failure compared to those with negative nodes. Postoperative RT reduced local recurrence and improved 3 year survival among patients with positive nodes. However, postoperative RT did not improve survival among those with negative nodes. Our data indicated that patients with positive hilar or mediastinal nodes may require postoperative RT to improve survival.

If the original electrode is damaged during pacemaker replacement for battery depletion, the operation becomes substantially more involved and hazardous. By drilling a hole in the back of the electrode connector housing and inserting an Allen wrench into the drill hole, an impacted electrode hub can be pushed free without placing stress on the electrode components. This technique is recommended whenever an electrode hub cannot be easily removed from a pacemaker during a replacement operation, as traction on the electrode not infrequently results in gross or occult damage to the Silastic sheath or conductive elements.

Reports of low pericardial-fluid complement levels in systemic lupus erythematosus and rheumatoid arthritis have been difficult to interpret, as few data are available to describe complement concentrations in patients without pericardial disease. The authors therefore determined normal values under standardized conditions of collection, storage, and assay. The normal ranges for pericardial-fluid C3, C4, and total hemolytic complement were 35-127 mg/dl, 6.3-23 mg/dl, and 1.9-9.1 CH50 units, respectively. Storage at -20 C resulted in a 50% reduction in values. Hence, storage at -70 C is recommended. As the level of pericardial-fluid total hemolytic complement is normally low, caution is needed in interpreting its apparent reduction in various immunologic diseases.

Creatine phosphate (CP) and ATP concentrations of left ventricular biopsies are being frequently used to determine the energy balance of the heart. The validity of these measurements depends upon preventing significant loss of ATP and CP prior to freezing the specimen. We have designed this study to determine if the time interval between cutting the biopsy and submerging it in cold isopentane has a significant effect upon the resulting concentrations of ATP and CP. These biopsies were taken on dogs on cardiopulmonary bypass. We used a biopsy drill which was modified to allow us to vary and time the interval between cutting and submersion of the biopsy in isopentane. We found that the concentration of creatine phosphate in the myocardium at completion of the cut was 12.7 μmole/g wet weight and that the loss of creatine phosphate was 5.5% per second before cooling. The corresponding concentration of ATP was 6.8 μmole/g wet weight and the loss was 2% per second. The correlation coefficient for the semilog regression analysis for CP was 0.72 ( F = 95.3; P = 0.0001) and for ATP was 0.47 ( F = 24.6; P = 0.0001). The loss of high-energy phosphates is significant when there is a delay between cutting and freezing of the specimen. We recommend that myocardial biopsies be frozen as quickly as possible and are developing a drill to accomplish this.

The management of a patient with avulsion of the innominate artery from the aortic arch associated with a longitudinal tear on the posterior aspect of the trachea is discussed. It is obviously important to make both diagnoses preoperatively to determine priorities in the surgical management. If the airway injury can be managed by tracheal intubation, then it is recommended that the vascular injury be repaired first. If there is a persistent air leak with respiratory distress, then it is necessary to repair the tracheal injury before performing the vascular procedure. In some patients it may be appropriate to treat the tracheal injury nonoperatively.

The case of a 25-year-old man who had periosteal osteogenic sarcoma with intravascular metastases in unusual locations is reported. The patient presented with acute renal failure, unilateral pulmonary edema, functional mitral stenosis, and low cardiac output. After successful surgical removal of a left atrial metastasis with subsequent improvement in cardiac output, renal function improved only transiently and urinary output varied markedly. At autopsy, metastatic osteogenic sarcoma was discovered within the lumen of the abdominal aorta obstructing both renal arteries. The case is the first report of a neoplasm metastatic to the aorta causing intermittent bilateral renal arterial obstruction; it illustrates the diagnostic difficulties presented by intravascular metastatic disease.

We used intrapleural instillation of quinacrine hydrochloride in 20 patients (Group A) with recurrent spontaneous pneumothorax (one bilateral) and compared their clinical course with 19 patients who underwent thoracotomy and scarification or pleurectomy (Group B) and 63 patients treated by tube thoracostomy alone (Group C). In Group A, there was one complication of treatment, a pneumothorax immediately following tube removal, which necessitated repeat tube thoracostomy, and there was one late ipsilateral recurrence 2 years after treatment. These 20 patients with 21 recurrent spontaneous pneumothoraces treated with intrapleurally administered quinacrine have been followed for from 6 months to more than 4 years with only one late recurrence on the treated side. Eight patients in Group B had postoperative complications: 2 patients who had had pleurectomy required reoperation for postoperative bleeding; lobar pneumonia developed in 3; 1 had lack of total expansion of the lung; an intrathoracic hematoma developed in 1; and an ipsilateral pneumothorax necessitating tube thoracostomy developed in 1. In Group C, the rate of recurrence of pneumothorax was 23% during the first year following treatment. Intrapleural instillation of quinacrine is a simple, low-risk, reliable, and effective treatment for recurrent spontaneous pneumothorax, and is equally as effective as thoracotomy and scarification.

The effectiveness of a cardioplegic solution is dependent on maintaining adequate myocardial perfusion as the heart is cooled. Due to dissimilar rheological properties of blood (BC) and crystalloid (CC) cardioplegic solutions, differences in coronary vascular resistance (CVR) would be expected to develop during postarrest, hypothermic perfusion. To characterize rheologic differences between hypothermic BC and CC, we measured the viscosity of both solutions at 5°C intervals from 30 to 10°C with a Brookfield concentric cylinder viscometer. To evaluate hypothermic changes in CVR, we measured myocardial temperature, perfusion pressure, and perfusate flow during the injection of BC at 10°C in five dogs and CC at 10°C in five dogs. CVR was calculated from simultaneous, postarrest pressure and flow measurements taken at 5°C intervals from 30 to 15°C. The viscosity of BC increased from 1.72 ± 0.25 cP at 30°C to 2.67 cP at 10°C, while the viscosity of CC increased from 0.94 ± 0.02 to 1.44 ± 0.02 cP over the same temperature range. For BC, CVR increased from 0.134 ± 0.035 mm Hg·ml −1 ·min at 30°C to 0.199 ± 0.069 mm Hg·ml −1 ·min at 15°C, while CVR for CC increased from 0.0972 ± 0.024 to 0.111 ± 0.020 Hg·ml −1 ·min at 15°C. Two-way analysis of variance demonstrated that viscosity ( F = 48.5, P = 0.0001) and CVR ( F = 5.82, P = 0.042) were greater for BC than CC. Decreasing temperature resulted in significant differences in viscosity ( F = 347.3, P = 0.0001) and CVR ( F = 11.45, P = 0.0001) for the cardioplegic solutions. We have demonstrated that myocardial cooling results in a more pronounced increase in CVR for BC than for CC which can, in part, be attributed to differences in viscosity. As a consequence, BC will require a perfusion pressure higher than that of CC to maintain coronary flow with decreasing myocardial temperature.

Hetastarch, a synthetic colloid osmotic plasma volume expander, was employed in a prime for cardiopulmonary bypass in 37 patients undergoing myocardial revascularization. Comparison of laboratory values to those of 42 patients undergoing myocardial revascularization using an albumin-containing prime showed lower postoperative platelet counts (p less than 0.02) with hetastarch. There were no differences in chest tube drainage, blood use, plasma hemoglobin, fibrinogen levels, of coagulation times. The hetastarch prime cost $119.50 per patient, whereas the albumin-containing prime cost $321.35 per patient.

The authors look at the use of pacemakers in three groups of patients: one with previously implanted cardiac pacemakers, one requiring temporary pacing systems for reasons related to their heart, and one in whom indications exist for permanent pacemaker implantation, but because of a surgical emergency, cannot have a permanent unit implanted before the noncardiac operation.

Right ventricular failure following cardiac surgery must be rapidly diagnosed and treated to minimize injury to the heart. Switching from aortic to pulmonary artery perfusion during cardiopulmonary bypass is a method of rapidly testing the adequacy of right ventricular function and supporting the ventricle if necessary. A centrifugal pump has been used for long-term support for two cases managed in this manner.