Making personalized medicine a reality: the challenges of a modern translational research biopsy-driven program in an academic setting: the Segal Cancer Center experience

The success of personalized medicine in the oncology clinic is very dependent on the results from a translational research effort to identify individual and host molecular biomarkers to enable proper selection of anti-cancer therapy. For this to happen, it is necessary to obtain timely access to high-quality biological samples of both host and tumor tissues and biological fluids. At the Segal Cancer Center, we have initiated several prospective sample collections based on research-driven breast biopsies in different contexts, including primary and metastatic breast lesions in patients receiving specific treatments. We here describe some of the challenges involved in such a translational research program and our experience in setting up biopsy-driven research protocols, highlighting the human aspects of conducting these complex enterprises.     

Human ESCs predisposition to karyotypic instability: Is a matter of culture adaptation or differential vulnerability among hESC lines due to inherent properties?

Background  

The use of human embryonic stem cells (hESCs) in research is increasing and hESCs hold the promise for many biological, clinical and toxicological studies. Human ESCs are expected to be chromosomally stable since karyotypic changes represent a pitfall for potential future applications. Recently, several studies have analysed the genomic stability of several hESC lines maintained after prolonged in vitro culture but controversial data has been reported. Here, we prompted to compare the chromosomal stability of three hESC lines maintained in the same laboratory using identical culture conditions and passaging methods.     

Effect of α2B-Adrenoceptor Polymorphism on Peripheral Vasoconstriction in Healthy Volunteers

Background: Alpha-2B adrenoceptor is the vasoconstrictive subtype in the mouse. Human [alpha]2B-AR deletion (D) allele has been associated with loss of short-term agonist-promoted receptor desensitization, which may lead to increased vasoconstriction on [alpha]2 activation. The goal of this study was to test the hypothesis that [alpha]2B-adrenoceptor activation induces enhanced vasoconstriction in carriers of the DD genotype, compared with carriers of the insertion/insertion (II) genotype.

Methods: The authors administered increasing doses of dexmedetomidine (targeting plasma concentrations of 0.15, 0.3, 0.6, and 1.2 ng/ml) to 16 healthy young volunteers (8 carrying the [alpha]2B DD genotype, 8 carrying the II genotype) in whom sympatholytic effects of the drug were attenuated by general anesthesia. Measurements were made of finger blood volume (an indicator of vasoconstriction) by photoplethysmographic determination of light transmitted through a finger, finger blood flow by venous occlusion plethysmography, and hemodynamic variables.

Results: All concentration of dexmedetomidine increased light transmitted through the finger (vasoconstriction) and systolic blood pressure and decreased heart rate in both groups (P < 0.001 for all). Dexmedetomidine reduced finger arterial inflow only in the DD group (P < 0.001). Dexmedetomidine had no effect on finger venous outflow or venous capacitance. There were no significant differences between the II and DD groups in any of the variables.     

Can postgraduate courses in Maternal-Fetal Medicine change clinical attitude?

OBJECTIVE: To investigate the effect of structured didactic lectures by leaders in the field of Maternal-Fetal Medicine on reported clinical decision-making. METHODS: An interactive survey of obstetric management was performed as part of a postgraduate course at the 2004 Annual Meeting of the Society for Maternal-Fetal Medicine. Seven controversial topics were addressed, including tocolytic therapy, progesterone supplementation for the prevention of preterm birth, screening for inherited thrombophilia, cervical cerclage for a shortened cervix, the management of preterm premature rupture of membranes, magnesium sulfate seizure prophylaxis, and dexamethasone therapy for hemolysis, elevated liver enzymes, and low platelets (HELLP) syndrome. The survey was carried out before and after a series of structured didactic lectures, thereby allowing for analysis of the effect of the lectures on reported clinical decision-making. RESULTS: A total of 298 obstetric care providers attended the postgraduate course. By report, the majority of attendees were Maternal-Fetal Medicine specialists (60.7%), less than 10 years out from specialty training (56.3%), and practicing in a university-based setting (52.9%). An average of 233 practitioners (range 157-298) answered each question. Comparison of responses to the survey given before and after the lectures demonstrated significant differences, especially in the areas of tocolytic therapy and inherited thrombophilias. CONCLUSIONS: Postgraduate lectures by leaders in the field of Maternal-Fetal Medicine have significant immediate impact on reported clinical decision-making.     

Abnormal ventilatory responses in patients with Prader-Willi syndrome

Abnormal ventilatory control in patients with Prader-Willi syndrome when awake and sleeping include abnormal responses to hyperoxia, hypoxia and hypercarbia. Lindgren et al., report similar results regarding response to hypoxia; however, they have demonstrated significant minute ventilation and carbon dioxide responses in their patients treated with growth hormone irrespective of body mass index. It is possible that the explanation for the abnormal respiratory control in this syndrome is located in central rather than peripheral structures. The hypothalamus stands out as the possible location that links their abnormal ventilatory control with the other features. Further investigations to correlate this finding are warranted. Received: 20 April 1999 / Accepted: 21 April 1999     

Two cases of intoxication with new synthetic opioid,U-47700

Background: Novel substances often referred to as “designer drugs” have emerged as drugs of abuse, and recognition of these is difficult as routine blood and urine screening tests do not detect these agents. U-47700 is a synthetic selective μ-opioid agonist that can be bought online for as little as $40 per gram. We report two patients presenting after insufflation of U-47700, with subsequent confirmation of this substance in urine samples.

Case details: A 26-year-old man and 24-year-old woman insufflated a substance they believed to be “synthetic cocaine.” The man was found down with cyanosis and agonal respirations. He was intubated and taken to hospital where he recovered well with supportive care. The woman presented with anxiety, tremors and drowsiness and was admitted for observation. Urine samples from both patients were analyzed using GC/MS/MS and LC/QToF, and U-47700 was isolated in both cases. No other opioids were detected.

Discussion: These cases are concerning because U-47700 is a relatively new agent that is easy to obtain over the internet and has the potential to cause significant morbidity and mortality.     

Retroviral transduction of hematopoietic cells differentiated from human embryonic stem cell-derived CD45(neg)PFV hemogenic precursors.

Human embryonic stem cells (hESCs) provide a unique opportunity to study molecular mechanisms that regulate specification of the hematopoietic lineage in the human. Exploitation of this model using transgenic strategies depends on the ability to target cells of the hematopoietic lineage effectively and establish stable transgene expression. Here, a recently defined subpopulation of endothelial-like precursors derived from hESCs that is exclusively responsible for hematopoietic cell fate (CD45(neg)PFV) is shown to express GALVR-1 receptor and be efficiently transduced with GALV-pseudotyped retrovirus. Retroviral transduction, measured by enhanced green fluorescent protein, of hESC-derived CD45(+) cells differentiated from isolated CD45(neg)PFV precursors was 26.5 +/- 13% with 5.6 +/- 4% of these cells coexpressing CD34. An average of 17.5% of clonogenic hematopoietic progenitors derived from CD45(neg)PFV precursors expressed the retroviral transgene. Addition of serum to cultures after retroviral exposure supported transgene expression in resulting hematopoietic cells derived from hemogenic CD45(neg)PFV precursors. Our study represents the first report to demonstrate that retroviral transduction systems, similar to those used currently in clinical gene therapy protocols, are capable of efficient transduction of hematopoietic progenitors derived from hESCs.     

MRI for pelvic floor dysfunction: can the strain phase be eliminated?

Purpose

The purpose of the study was to determine if the strain phase of an MR defecography (MRD) protocol is redundant and can be eliminated without a loss of diagnostic information.

Materials and methods

Institutional review board approval was obtained and the requirement for informed consent was waived. A retrospective single-center review of 80 MRD examinations (68 female, 12 male, mean age 55 years old) was conducted. Two radiologists blinded to patient information evaluated in consensus the strain and evacuation phases separately and in a random order. Each phase was assessed for the presence and degree of posterior compartment descent, cystocele, urethral hypermobility, uterovaginal prolapse, rectocele, rectal intussusception, and enterocele. The degree of pelvic floor descent was compared using a paired t test and McNemar’s test was used to compare the proportion of abnormal findings.

Results

The evacuation phase identified all abnormalities identified on the strain phase and also identified both additional and more pronounced abnormalities, including an additional 34 cystoceles, 20 cases of urethral hypermobility, 13 uterovaginal prolapses, 36 rectoceles, 5 rectal intussusceptions, and 6 enteroceles (all p < 0.02). The mean posterior compartment descent was 24.1 mm greater on the evacuation phase than the strain phase (p < 0.0001).

Conclusion

The strain phase is redundant and we propose that it can be eliminated from a routine MRD protocol. This will help streamline the examination, simplify patient instructions, and reduce both imaging and reporting time.