Medical Specialties Commons^™

Obesity And Other Predictors Of Absenteeism In Philadelphia School Children., Elizabeth B Rappaport, Constantine Daskalakis, Jocelyn Andrel

Department of Family & Community Medicine Faculty Papers

BACKGROUND: Limited data indicate that obese children are absent from school more than their normal-weight peers. We analyzed administrative data from a large urban school district to investigate the association of obesity and student sociodemographic characteristics with absenteeism.

METHODS: We analyzed 291,040 records, representing 165,056 unique students (grades 1-12). Obesity status was classified according to Centers for Disease Control and Prevention age- and sex-specific percentiles for body mass index (BMI) and analyses were based on negative binomial regression.

RESULTS: Overall rates of overweight and obesity were 17% and 20%, respectively, and the estimated absence rate was 17 absences per 180 …

Transfection Of Human Platelets With Short Interfering Rna., Wei Hong, Altaf A Kondkar, Srikanth Nagalla, Wolfgang Bergmeier, Ying Jin, Jay Herman, Paul Bray

Cardeza Foundation for Hematologic Research

Platelets contain mRNAs and are capable of translating mRNA into protein, and it has been previously demonstrated that platelets increase their levels of integrin β3 overtime while in blood bank storage conditions. We are unaware of prior attempts to introduce nucleic acids into platelets. Considering the potential clinical and research utility of manipulating platelet gene expression, we tested whether small interfering RNAs (siRNAs) could be transfected into normal human platelets. Multiple conditions were tested, including lipofectamine versus electroporation, different amounts of siRNA, the effect of different buffers and the presence of plasma during transfection, and the time for optimal siRNA …

Surgical Management Of Complete Atrioventricular Septal Defect: Associations With Surgical Technique, Age, And Trisomy 21., Andrew M. Atz, John A. Hawkins, Minmin Lu, Meryl S. Cohen, Steven D. Colan, James Jaggers, Ronald V. Lacro, Brian W. Mccrindle, Renee Margossian, Ralph S. Mosca, Lynn A. Sleeper, L Luann Minich, Pediatric Heart Network Investigators, Girish S. Shirali

Manuscripts, Articles, Book Chapters and Other Papers

OBJECTIVES: We sought to evaluate the contemporary results after repair of a complete atrioventricular septal defect and to determine the factors associated with suboptimal outcomes.

METHODS: The demographic, procedural, and outcome data were obtained within 1 and 6 months after repair of a complete atrioventricular septal defect in 120 children in a multicenter observational study from June 2004 to 2006.

RESULTS: The median age at surgery was 3.7 months (range, 9 days to 1.1 years). The type of surgical repair was a single patch (18%), double patch (72%), and a single atrial septal defect patch with primary ventricular septal defect …

Femoroacetabular Impingement: Saving The Joint, Ronald Huang, Javad Parvizi

Department of Orthopaedic Surgery Faculty Papers

Many factors have been linked to the development of osteoarthritis (OA) of the hip, but often, cases are still considered “idiopathic.” Femoroacetabular impingement (FAI) has been suggested as a possible etiologic factor for the otherwise “idiopathic” cases. It is theorized that the subtle morphologic abnormalities seen at the head-neck junction and acetabulum in FAI may lead to labral tears, chondral damage, and subsequent progression of OA. Prevalence of FAI has been suggested to be as high as 14% in the general population. It often presents in young active patients that subject their hip joint to repetitive micro trauma associated with …

Preliminary Report--Near Total Laryngectomy For Scc Larynx, Asif Arain, Shehzad Ghaffar

Section of Otolaryngology, Head & Neck Surgery

A retrospective analysis was performed on patients subjected to near-total laryngectomy at Aga Khan University Hospital Karachi from September 2006 and May 2010, to evaluate the functional outcome of Near Total Laryngectomy and its effect on disease control. In all of these advanced stage laryngeal-hypopharyngeal squamous cancer patients, the disease was limited to one side of the larynx-hypopharynx. Four patients were staged as T3 and rest were T4; near total laryngectomy was done in all 07 patients. Post operative adjuvant radiotherapy was given to 06 patients. All of these patients are on regular oral diet and maintaining their body weight. …

Evaluation Of The Use Of Patient-Focused Simulation For Student Assessment In A Surgery Clerkship., Gerald A Isenberg, Katherine W Berg, Judith A Veloski, Dale D Berg, J J. Veloski, Charles Yeo

Department of Surgery Faculty Papers

BACKGROUND: The purpose of this study was to evaluate the use of simulated patients in conjunction with anatomic and tissue task-training models to assess skills.

METHODS: Faculty reviewed the objectives of the clerkship to identify skills to be acquired. Three cases were developed related to rectal examination, suturing, and inserting intravenous lines and nasogastric tubes. Student scores were based on their ability to gather data from simulated patients and perform procedures on simulation models.

RESULTS: A total of 670 students were assessed between 2006 and 2009. Alpha reliability coefficients were .97 for Communication/Interpersonal Skills, .71 for Procedures, and .58 for …

Chemical Cardiomyopathies: The Negative Effects Of Medications And Nonprescribed Drugs On The Heart., Vincent M Figueredo

Division of Cardiology Faculty Papers

The heart is a target of injury for many chemical compounds, both medically prescribed and not medically prescribed. Pathophysiologic mechanisms underlying the development of chemical-induced cardiomyopathies vary depending on the inciting agent, including direct toxic effects, neurohormonal activation, altered calcium homeostasis, and oxidative stress. Numerous chemicals and drugs are implicated in cardiomyopathy. This article discusses examples of medication and nonprescribed drug-induced cardiomyopathies and reviews their pathophysiologic mechanisms.

Endothelial Differentiation Of Adipose-Derived Stem Cells From Elderly Patients With Cardiovascular Disease., Ping Zhang, Neil Moudgill, Eric Hager, Nicolas Tarola, Christopher Dimatteo, Stephen Mcilhenny, Thomas Tulenko, Paul J Dimuzio

Department of Surgery Faculty Papers

Adipose-derived stem cells (ASCs) possess significant therapeutic potential for tissue engineering and regeneration. This study investigates the endothelial differentiation and functional capacity of ASCs isolated from elderly patients. Isolation of ASCs from 53 patients (50-89 years) revealed that advanced age or comorbidity did not negatively impact stem cell harvest; rather, higher numbers were observed in older donors (>70 years) than in younger. ASCs cultured in endothelial growth medium-2 for up to 3 weeks formed cords upon Matrigel and demonstrated acetylated-low-density lipoprotein and lectin uptake. Further stimulation with vascular endothelial growth factor and shear stress upregulated endothelial cell-specific markers (CD31, …

Aua Guideline For The Diagnosis And Treatment Of Interstitial Cystitis/Bladder Pain Syndrome, Philip M Hanno, David Allen Burks, J Quentin Clemens, Roger R Dmochowski, Deborah Erickson, Mary Pat Fitzgerald, John B Forrest, Barbara Gordon, Mikel Gray, Robert Dale Mayer, Diane Newman, Leroy Nyberg, Christopher K Payne, Ursula Wesselmann, Martha M Faraday

Faculty, Staff and Student Publications

PURPOSE: To provide a clinical framework for the diagnosis and treatment of interstitial cystitis/bladder pain syndrome.

MATERIALS AND METHODS: A systematic review of the literature using the MEDLINE® database (search dates 1/1/83-7/22/09) was conducted to identify peer reviewed publications relevant to the diagnosis and treatment of interstitial cystitis/bladder pain syndrome. Insufficient evidence-based data were retrieved regarding diagnosis and, therefore, this portion of the Guideline is based on Clinical Principles and Expert Opinion statements. The review yielded an evidence base of 86 treatment articles after application of inclusion/exclusion criteria. These publications were used to create the majority of the treatment portion …

Acute Effects Of A Selective Cannabinoid-2 Receptor Agonist On Neuroinflammation In A Model Of Traumatic Brain Injury., Melanie B Elliott, Ronald F Tuma, Peter S Amenta, Mary F Barbe, Jack I Jallo

Department of Neurosurgery Faculty Papers

Proposed therapeutic strategies for attenuating secondary traumatic brain injury (TBI) include modulation of acute neuroimmune responses. The goal of this study was to examine the acute effects of cannabinoid-2 receptor (CB(2)R) modulation on behavioral deficits, cerebral edema, perivascular substance P, and macrophage/microglial activation in a murine model of TBI. Thirty male C57BL/6 mice underwent sham surgery, or cortical contusion impact injury (CCI). CCI mice received vehicle or the CB(2)R agonist 0-1966 at 1 and 24 h after injury. Performance on the rotarod, forelimb cylinder, and open-field tests were evaluated before and at 48 h after sham or CCI surgery. Cerebral …

Magnetic Resonance Spectroscopy In Focal Brain Lesions, Muhammad Shahbaz Alam, Zafar Sajjad, Saima Hafeez, Waseem Akhter

Department of Radiology

OBJECTIVE: To describe the spectrum of Magnetic Resonance spectroscopy in focal brain lesions and determine its diagnostic accuracy using histopathology as gold standard in differentiating neoplastic and non-neoplastic focal brain lesions.

METHODS: The study was conducted in Department of Radiology, Aga Khan University Hospital, Karachi from Dec 2006 till Jan 2009. Fifty three patients found to have focal brain lesions on magnetic resonance imaging (MRI) were included in the study. Magnetic Resonance spectroscopy (MRS) was performed in these focal lesions. These lesions were deemed neoplastic and non-neoplastic on MR Spectrum findings. Correlation of all these findings was done with histopathology …

What Are The Emerging Therapeutic Alternatives To Warfarin In Stroke Patients? How Would The Results Of Re-Ly Benefit Pakistanis, Maria Khan, Emmon Raza, Ayeesha Kamran Kamal

Section of Neurology

No abstract provided.

Ct Scanning Is Sufficient To Clear The Cervical Spine Of Elderly Falls Less Than 5 Feet., Douglas Lehman Md, Rovinder S. Sandhu Md, Leslie Baga Bsn, Farheen Hussain Ms, John J. Hong Md

Administration & Leadership

No abstract provided.

Religious Experiences Shrink Part Of The Brain, Andrew Newberg, M.D.

Marcus Institute of Integrative Health Faculty Papers

A study links life-changing religious experiences, like being born again, with atrophy in the hippocampus.

The article, “Religious factors and hippocampal atrophy in late life,” by Amy Owen and colleagues at Duke University represents an important advance in our growing understanding of the relationship between the brain and religion. The study showed greater atrophy in the hippocampus in individuals who identify with specific religious groups as well as those with no religious affiliation. It is a surprising result, given that many prior studies have shown religion to have potentially beneficial effects on brain function, anxiety, and depression.

Renin-Angiotensin-Aldosterone Genotype Influences Ventricular Remodeling In Infants With Single Ventricle., Seema Mital, Wendy K. Chung, Steven D. Colan, Lynn A. Sleeper, Cedric Manlhiot, Cammon B. Arrington, James F. Cnota, Eric M. Graham, Michael E. Mitchell, Elizabeth Goldmuntz, Jennifer S. Li, Jami C. Levine, Teresa M. Lee, Renee Margossian, Daphne T. Hsu, Pediatric Heart Network Investigators, Girish S. Shirali

Manuscripts, Articles, Book Chapters and Other Papers

Background: We investigated the effect of polymorphisms in the renin-angiotensin-aldosterone system (RAAS) genes on ventricular remodeling, growth, renal function, and response to enalapril in infants with single ventricle.

Methods and results: Single ventricle infants enrolled in a randomized trial of enalapril were genotyped for polymorphisms in 5 genes: angiotensinogen, angiotensin-converting enzyme, angiotensin II type 1 receptor, aldosterone synthase, and chymase. Alleles associated with renin-angiotensin-aldosterone system upregulation were classified as risk alleles. Ventricular mass, volume, somatic growth, renal function using estimated glomerular filtration rate, and response to enalapril were compared between patients with ≥2 homozygous risk genotypes (high risk), and those …

Diagnostic Accuracy Of Fine Needle Aspiration Cytology In Parotid Lesions, Naeem Sultan Ali, Shabbir Akhtar, Montasir Junaid, Sohail Awan, Kanwal Aftab

Section of Otolaryngology, Head & Neck Surgery

Objective:Histopathology of parotid gland tumors is extremely varied and complex due to heterogeneous cellular composition. Preoperative diagnostic tools include fine needle aspiration cytology, the role of which remains controversial. The aim of this paper is to evaluate the usefulness and accuracy of fine needle aspiration cytology (FNAC) in the diagnosis of parotid gland tumors.

Methods:

We retrospectively reviewed charts of 129 Patients who underwent parotidectomy for parotid lesions at Aga Khan University Hospital from 2002 to 2010. We compared the results of preoperative FNAC with final histopathological diagnosis.

Results:

Concordance with histological results was observed in 86%, specificity was …

Primary School Vision Screening Involving Teachers In Nampula, Mozambique, Aoife Phelan, Lisa O'Donoghue, Kathryn Saunders, Stephen Thompson, Vivien Ocampo, Kevin Naidoo, James Loughman

Conference Papers

Purpose: There is no plan for a national child eye care programme or existing human resource infrastructure to address the immediate challenge of child eye health in Mozambique.This study aims to design, implement and evaluate a school based pediatric vision screening service, to identify those in need of eye care services, among Mozambique’s 11,561,000 children.

Methods: Primary School Screening took place in three schools in Nampula, Mozambique in September 2010 and March 2011. The children’s vision was screened by an optometry student, optometrist or teacher with Log MAR ETDRS letters at 4 Meters. Ophthalmoscopy was performed on all children by …

Patient Discomfort Associated With The Use Of Intra-Arterial Iodinated Contrast Media: A Meta-Analysis Of Comparative Randomized Controlled Trials, Peter A. Mccullough, Patrizio Capasso

Radiology Faculty Publications

BACKGROUND: Discomfort characterized by pain and warmth are common adverse effects associated with the use of intra-arterial iodinated contrast media (CM). The objective of this review was to pool patient-reported outcomes available from head-to-head randomized controlled trials (RCTs) and to compare the discomfort rates associated with iso-osmolar contrast media (IOCM; i.e., iodixanol) to those reported with various low-osmolar contrast media (LOCM).

METHODS: A review of the literature published between 1990 and 2009 available through Medline, Medline Preprints, Embase, Biological Abstracts, BioBase, Cab Abstracts, International Pharmaceutical Abstracts, Life Sciences Collection, Inside Conferences, Energy Database, Engineering Index and Technology Collection was performed …

Oral Ingestion Of Hexavalent Chromium Through Drinking Water And Cancer Mortality In An Industrial Area Of Greece - An Ecological Study, Athena Linos, Athanassios Petralias, Costas A. Christophi, Eleni Christoforidou, Paraskevi Kouroutou, Melina Stoltidis, Afroditi Veloudaki, Evangelia Tzala, Konstantinos C. Makris, Margaret R. Karagas

Dartmouth Scholarship

Background: Hexavalent chromium is a known carcinogen when inhaled, but its carcinogenic potential when orally ingested remains controversial. Water contaminated with hexavalent chromium is a worldwide problem, making this a question of significant public health importance.

Methods: We conducted an ecological mortality study within the Oinofita region of Greece, where water has been contaminated with hexavalent chromium. We calculated gender, age, and period standardized mortality ratios (SMRs) for all deaths, cancer deaths, and specific cancer types of Oinofita residents over an 11-year period (1999 - 2009), using the greater prefecture of Voiotia as the standard population.

Results: A total of …

Effects Of Walnut Consumption As Part Of Heart Healthy Diet On Atherogenic Lipoprotein Subclasses, Kimberly L. Dulaney, Md, John M. Morgan, Md, David M. Capuzzi, Md

The Medicine Forum

Nutritional therapy is fundamental in the treatment of
cardiovascular disease. Studies that utilized a low-fat diet
supplemented with 64 grams/day of walnuts have shown
a significant reduction in serum levels of total and LDL
cholesterol, and triglycerides. This study was designed to
see if lipoprotein subclasses varied in patients eating a
low-fat walnut supplemented diet.

Rheumatoid Arthritis-Associated Polymorphisms Are Not Protective Against Alzheimer's Disease, Christopher R. Simmons, Fanggeng Zou, Steven G Younkin, Steven Estus

Sanders-Brown Center on Aging Faculty Publications

BACKGROUND: Rheumatoid arthritis (RA) and Alzheimer's disease (AD) are inversely associated. To test the hypothesis that genetic elements associated with increased RA risk are associated with decreased AD risk, we evaluated RA genetic risk factors recently identified in genome-wide association studies (GWAS) for their association with AD in a two-stage, case-control analysis.

RESULTS: In our Stage 1 analysis of ~800 AD and ~1,200 non-AD individuals, three of seventeen RA-associated SNPs were nominally associated with AD (p < 0.05) with one SNP, rs2837960, retaining significance after correction for multiple testing (p = 0.03). The rs2837960_G (minor) allele, which is associated with increased RA risk, was associated with increased AD risk. Analysis of these three SNPs in a Stage 2 population, consisting of ~1,100 AD and ~2,600 non-AD individuals, did not confirm their association with AD. Analysis of Stage 1 and 2 combined suggested that rs2837960 shows a trend for association with AD. When the Stage 2 population was age-matched for the Stage 1 population, rs2837960 exhibited a non-significant trend with AD. Combined analysis of Stage 1 and the age-matched Stage 2 subset showed a significant association of rs2837960 with AD (p = 0.002, OR 1.24) that retained significance following correction for age, sex and APOE (p = 0.02, OR = 1.20). Rs2837960 is near BACE2, which encodes an aspartic protease capable of processing the AD-associated amyloid precursor protein. Testing for an association between rs2837960 and the expression of BACE2 isoforms in human brain, we observed a trend between rs2837960 and the total expression of BACE2 and the expression of a BACE2 transcript lacking exon 7 (p = 0.07 and 0.10, respectively).

CONCLUSIONS: RA-associated SNPs are generally not associated with AD. Moreover, rs2837960_G is associated with increased risk of both RA and, in individuals less than …

Four Year Experience Of Sarcoma Of Soft Tissues And Bones In A Tertiary Care Hospital And Review Of Literature, Tayyaba Z. Ansari, Nehal Masood, Asra Parekh, Rabab Z. Jafri, Syed N. Niamatullah, Adnan A. Zaidi, Masood Umer

Department of Medicine

Background:

Sarcoma encompasses an uncommon group of cancer and the data is insufficient from Pakistan. We report our four years experience of Sarcoma of soft tissues and bones.

Methods:

This cross sectional study was carried out at Aga Khan University Hospital from 2004 to 2008. The Patients were divided into two groups from the outset i.e. initially diagnosed and relapsed group and separate sub group analysis was conducted.

Results:

Out of 93 newly diagnosed Patients, 58 belonged to bone sarcoma and 35 to soft tissue sarcoma group. While for relapsed Patients, 5 had soft tissue sarcoma and 9 had bone …

Baseline Data For Maine Pediatric And Family Practices From Arra-Funded Hit Ambulatory Practice Survey Data, Kimberley S. Fox Mpa

Population Health & Health Policy

No abstract provided.

Possible Role Of Death Receptor-Mediated Apoptosis By The E3 Ubiquitin Ligases Siah2 And Posh, Perry A. Christian, Michael V. Fiandalo, Steven R. Schwarze

Markey Cancer Center Faculty Publications

BACKGROUND: A functioning ubiquitin proteasome system (UPS) is essential for a number of diverse cellular processes and maintenance of overall cellular homeostasis. The ability of proteasome inhibitors, such as Velcade, to promote extrinsic apoptotic effects illustrates the importance of the ubiquitin proteasome system in the regulation of death receptor signaling. Here, we set out to define the UPS machinery, particularly the E3 ubiquitin ligases, that repress apoptosis through the extrinsic pathway. A cell-based genome-wide E3 ligase siRNA screen was established to monitor caspase-8 activity following the addition of TRAIL.

RESULTS: Data from the high-throughput screen revealed that targeting the RING-finger …

Inhibition Of Phosphorylated C-Met In Rhabdomyosarcoma Cell Lines By A Small Molecule Inhibitor Su11274., Jinxuan Hou, Jixin Dong, Lijun Sun, Liying Geng, J. Wang, Jialin C. Zheng, Yan Li, Julia A. Bridge, Steven H. Hinrichs, Shi-Jian Ding

Journal Articles: Pathology and Microbiology

BACKGROUND: c-Met is a receptor tyrosine kinase (RTK) that is over-expressed in a variety of cancers and involved in cell growth, invasion, metastasis and angiogenesis. In this study, we investigated the role of c-Met in rhabdomyosarcoma (RMS) using its small molecule inhibitor SU11274, which has been hypothesized to be a potential therapeutic target for RMS.

METHODS: The expression level of phosphorylated c-Met in RMS cell lines (RD, CW9019 and RH30) and tumor tissues was assessed by phospho-RTK array and immunohistochemistry, respectively. The inhibition effects of SU11274 on RMS cells were studied with regard to intracellular signaling, cell proliferation, cell cycle …

Lipid Phosphate Phosphatase 3 Enables Efficient Thymic Egress, Béatrice Bréart, Willy D. Ramos-Perez, Alejandra Mendoza, Abdelghaffar K. Salous, Michael Gobert, Yong Huang, Ralf H. Adams, Juan J. Lafaille, Diana Escalante-Alcalde, Andrew J. Morris, Susan R. Schwab

Gill Heart & Vascular Institute Faculty Publications

The signaling lipid sphingosine-1-phosphate (S1P) stabilizes the vasculature, directs lymphocyte egress from lymphoid organs, and shapes inflammatory responses. However, little is known about how S1P distribution is controlled in vivo, and it is not clear how a ubiquitously made lipid functions as a signal that requires precise spatial and temporal control. We have found that lipid phosphate phosphatase 3 (LPP3) enables efficient export of mature T cells from the thymus into circulation, and several lines of evidence suggest that LPP3 promotes exit by destroying thymic S1P. Although five additional S1P-degrading enzymes are expressed in the thymus, they cannot compensate for …

Nfatc1 Regulation Of Trail Expression In Human Intestinal Cells, Qingding Wang, Yuning Zhou, Heidi L. Weiss, Chi-Wing Chow, B. Mark Evers

Surgery Faculty Publications

TNF-related apoptosis-inducing ligand (TRAIL; Apo2) has been shown to promote intestinal cell differentiation. Nuclear factor of activated T cells (NFAT) participates in the regulation of a variety of cellular processes, including differentiation. Here, we examined the role of NFAT in the regulation of TRAIL in human intestinal cells. Treatment with a combination of phorbol 12-myristate 13-acetate (PMA) plus the calcium ionophore A23187 (Io) increased NFAT activation and TRAIL expression; pretreatment with the calcineurin inhibitor cyclosporine A (CsA), an antagonist of NFAT signaling, diminished NFAT activation and TRAIL induction. In addition, knockdown of NFATc1, NFATc2, NFATc3, and NFATc4 blocked PMA/Io increased …

Multiple Courses Of Stereotactic Re-Irradiation In Recurrent Oligodendroglioma: A Case Report., Shannon Fogh, Charles Glass, David W Andrews, Maria Werner-Wasik

Department of Radiation Oncology Faculty Papers

INTRODUCTION: High grade gliomas are an insidious disease associated with an extremely poor prognosis. The role of re-irradiation for recurrent gliomas is unclear but several retrospective studies have indicated mild toxicity and modest outcomes with this regimen. With subsequent progression, it is unclear what options remain and more radiotherapy is rarely offered for fear of surpassing normal central nervous system tissue tolerance and causing significant side effects without significant benefit.

CASE PRESENTATION: In this report, we describe a 37-year-old Caucasian male initially diagnosed with a grade IV oligodendroglioma, who received multiple courses of re-irradiation and experienced a survival of 10 …

Evaluation Of A Medical And Mental Health Unit Compared With Standard Care For Older People Whose Emergency Admission To An Acute General Hospital Is Complicated By Concurrent ‘Confusion’: A Controlled Clinical Trial. Acronym: Team: Trial Of An Elderly Acute Care Medical And Mental Health Unit, Rowan H. Harwood, Sarah E. Goldberg, Kathy H. Whittamore, Catherine Russell, John Rf Gladman, Rob G. Jones, Davina Porock, Sarah A. Lewis, Lucy E. Bradshaw, Rachel A. Elliot

Publications and Research

Background: Patients with delirium and dementia admitted to general hospitals have poor outcomes, and their carers report poor experiences. We developed an acute geriatric medical ward into a specialist Medical and Mental Health Unit over an eighteen month period. Additional specialist mental health staff were employed, other staff were trained in the ‘person-centred’ dementia care approach, a programme of meaningful activity was devised, the environment adapted to the needs of people with cognitive impairment, and attention given to communication with family carers. We hypothesise that patients managed on this ward will have better outcomes than those receiving standard care, and …

Download The Full Pdf Of Jefferson Surgical Solutions Spring 2011, Volume 6, Number 1

Jefferson Surgical Solutions

No abstract provided.