Minimally invasive spine surgery: an animal model for endoscopic approach to the anterior cervical and upper thoracic spine

BACKGROUND: Minimally invasive video-assisted techniques are currently used for thoracic and lumbar spine surgery with the aim of reducing the morbidity. Recently, an endoscopic approach has been used for endocrine neck surgery, with reduced pain and improved cosmetic results. PURPOSE: To develop an animal model for an endoscopic neck approach to the anterior cervical and upper thoracic spine. METHODS: Five pigs were used. A combination of one 5- and two 3-mm laparoscopic instruments was used to dissect the spine, and dedicated instrumentation was then used to perform discectomies. Carbon dioxide was insufflated at 10 mm Hg. Dissection was carried out upward and downward on the anterior aspect of the spine; discectomy was performed at various levels and evaluated at autopsy. RESULTS: All pigs tolerated the procedure well. Visibility of the cervical spine was excellent, and exposure from C1 to T3 was obtained. For discectomy, an additional 10-mm trocar was inserted, and discectomy of C3-C4 and C4-C5 was performed. Proper location and adequacy were confirmed at autopsy. CONCLUSION: The endoscopic neck approach allows exposure of the entire cervical spine and the upper thoracic spine in the porcine model. This approach has the potential to reduce the morbidity associated with the open cervical approach and provides a wider view and exposure than conventional open surgery. The availability of the porcine model allows the acquisition of the necessary technical skills before introducing this advanced procedure in humans.     

Flow Visualization of Three-Dimensionality Inside the 12 cc Penn State Pulsatile Pediatric Ventricular Assist Device

In order to aid the ongoing concern of limited organ availability for pediatric heart transplants, Penn State has continued development of a pulsatile Pediatric Ventricular Assist Device (PVAD). Initial studies of the PVAD observed an increase in thrombus formation due to differences in flow field physics when compared to adult sized devices, which included a higher degree of three-dimensionality. This unique flow field brings into question the use of 2D planar particle image velocimetry (PIV) as a flow visualization technique, however the small size and high curvature of the PVAD make other tools such as stereoscopic PIV impractical. In order to test the reliability of the 2D results, we perform a pseudo-3D PIV study using planes both parallel and normal to the diaphragm employing a mock circulatory loop containing a viscoelastic fluid that mimics 40% hematocrit blood. We find that while the third component of velocity is extremely helpful to a physical understanding of the flow, particularly of the diastolic jet and the development of a desired rotational pattern, the flow data taken parallel to the diaphragm is sufficient to describe the wall shear rates, a critical aspect to the study of thrombosis and design of such pumps.     

Treatment outcome and survival in participants of phase I oncology trials carried out from 2003 to 2006 at Institut Gustave Roussy.

BACKGROUND: The oncology community usually perceives phase I oncology trials as associated with poor or limited benefits and substantial risks. There is scarce data concerning outcome and survival of patients enrolled in current phase I oncology trials. PATIENTS AND METHODS: We reviewed all phase I oncology trials conducted by investigators from the Adult Phase I Unit at Institut Gustave Roussy from 2003 to 2006. We report data concerning patient demographics, treatment outcome, toxicity, survival and type of care after trial exit. RESULTS: We analyzed 10 trials involving 180 participants. The overall response rate was 7.2%. Disease control (objective response plus stable disease) was achieved in 48.2% of patients. The rate of toxic death was 0.5%. In all, 38% of patients had at least one episode of grade 3 or 4 toxic events. The median progression-free survival and the median overall survival (OS) were 2.3 and 8.7 months, respectively. On multivariate analysis, a time between diagnosis of disease and inclusion in the phase I trial > or =24 months and evidence of disease control were statistically significant predictors of improved OS. CONCLUSION: Current phase I oncology trials are safe and are associated with clinical benefit in a substantial proportion of patients.     

Ethnic ancestry and increased paternal age are risk factors for breast cancer before the age of 40 years.

To study the risk factors associated with breast cancer in women younger than 40 years, a cohort study (The Jerusalem Perinatal Study) of 42 822 female offspring born in hospitals in West Jerusalem during 1964-1976 was carried out. Hazard ratios of potential parental and perinatal risk factors for early breast cancer were measured. The overall incidence of breast cancer was 5.2/100 000 person-years. The highest incidence was found among Jewish women of West Asian ancestry (8.6/100 000 person-years), specifically those whose maternal grandfathers were born in Iraq, Iran or Afghanistan (9.5/100 000 person-years). Using Cox models we found independent risk factors for early breast cancer to be paternal age (relative risk/year=1.06, 95% confidence interval=1.02-1.10, P=0.005), and ancestry from Iraq/Iran/Afghanistan (relative risk=3.1, 95% confidence interval=1.50-6.52, P=0.002). The study confirms a previously observed effect of advanced paternal age on the occurrence of early breast cancer and identifies a novel population group at increased risk for the disease. The excess risk of early breast cancer associated with ancestry from Iraq, Iran and Afghanistan suggests involvement of genetic determinants, environmental exposures and/or lifestyle factors and mandates further investigation.     

Folate sufficient subjects do not accumulate additional folates during supplementation

In a double-blinded placebo-controlled trial of folic acid supplementation in 82 alcoholic subjects, it was found that whole blood folate levels, determined by a mass spectrometric method, do not increase in subjects whose baseline folate levels are above the third quartile (folate sufficiency). Since a state of folate sufficiency can now be identified, a recommended daily allowance (RDA) for folate can be determined using objective means.     

Differentiating malignant from benign ovarian tumors with transvaginal color flow imaging.

The impedance to blood flow was examined by transvaginal color flow imaging in 53 ovarian masses before exploratory laparotomy. Serum CA 125 levels were measured in all subjects. Thirty-six had benign ovarian tumors and 17 had malignant ovarian tumors confirmed by histopathologic examination. Intratumoral blood vessels, detected in 16 of the malignant tumors, consistently demonstrated low impedance to flow, with a pulsatility index (PI) always below 1. The PI of the intraovarian or intratumoral blood vessels was greater than 1 in 35 of the 36 benign tumors, although 11 had suspicious sonographic findings (P less than .01) and 14 had elevated CA 125 levels (P less than .001). The sensitivity and specificity of the preoperative PI in detecting malignant ovarian tumors were 94 and 97%, respectively. The sensitivity and specificity of preoperative suspicious sonographic findings in detecting malignant ovarian tumors were 94 and 69%, and those of elevated preoperative serum CA 125 levels were 82 and 61%, respectively. Our results suggest that transvaginal color flow imaging may be a useful clinical tool in the preoperative evaluation of ovarian masses.     

A new automated tumor registry and clinical research system and its application to gynecologic oncology patients

Every physician at one time or another wishes that he could quickly recall, group and stratify elements of his past practice and apply that experience toward solving a current problem. In Oncology attempts to use hospital registries for this purpose are often disappointing, as few are computerized and most lack the detail, accuracy, and flexibility to be truly responsive. The development of our current Gynecologic Oncology Tumor registry began in 1982. The final product results from the cooperation of a computer specialist, a registrar, physicians, and nurses. In addition, three independent programs have been incorporated to expand the statistical and reporting functions of the registry. The result is a tumor registry that is the foundation of a clinical research system.     

Effect of hindlimb suspension and clenbuterol treatment on polyamine levels in skeletal muscle

Polyamines are unbiquitous, naturally occurring small aliphatic, polycationic, endogenous compounds. They are involved in many cellular processes and may serve as secondary or tertiary messengers to hormonal regulation. The relationship of polyamines and skeletal muscle mass of adductor longus, extensor digitorum longus, and gastrocnemius under unloading (hindlimb suspension) conditions was investigated. Unloading significantly affected skeletal muscle polyamine levels in a fiber-type-specific fashion. Under loading conditions, clenbuterol treatment increased all polyamine levels, whereas under unloading conditions, only the spermidine levels were consistently increased. Unloading attenuated the anabolic effects of clenbuterol in predominately slow-twitch muscles (adductor longus), but had little impact on clenbuterol's action as a countermeasure in fast- twitch muscles such as the extensor digitorum longus. Spermidine appeared to be the primary polyamine involved in skeletal muscle atrophy/hypertrophy.