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Biomedical subjects

Patrick K Y Goon

Publications and source records attributed to Patrick K Y Goon.

9 recordsLinked to original sources

Temporal and venepuncture-related decline in circulating endothelial cell capture from mixed venous blood.

BACKGROUND: The quantification of circulating endothelial cells (CECs) in whole blood has evolved as a novel method for the assessment of endothelial function, although major methodological issues remain. We hypothesized that there is a temporal decline in CEC counts in static venesected blood and that venepuncture itself may lead to increased CEC detachment. METHODS: CEC isolation was performed using the immunobead method. For the temporal decline experiment, we included 52 patients presenting with acute coronary syndrome (ACS). We performed CEC counts immediately and at 4 and 24 h later. For the venepuncture decline experiment, we studied 40 patients with stable cardiovascular disease (CVD). CEC counts were determined from the first 4 mL of aspirated venous blood and compared with counts obtained from a subsequent 4 mL sample of blood after at least 7.5 mL of blood had been collected. RESULTS: Among the ACS patients there was a significant temporal decline in CEC counts in static venous blood over a 24 h period (p = 0.013). Among the patients with stable CVD, the median CEC counts obtained from the initial 4 mL of aspirated venous blood were significantly higher (by 32%) than that obtained from the later 4 mL of aspirated venous blood (p = 0.041). CONCLUSIONS: We demonstrated a significant temporal fall in CEC numbers in static venous blood over 24 h following venesection. Furthermore, we have shown that CEC counts are higher in the initial aspirated blood compared with that aspirated from the same needle subsequently. These data would have implications for how CEC determination is undertaken by researchers in studies related to ACS or CVD.

Adult↗

Detection and quantification of mature circulating endothelial cells using flow cytometry and immunomagnetic beads: a methodological comparison.

Mature circulating endothelial cells (CECs) are novel cellular markers of endothelial damage/dysfunction. The two main techniques of CEC enumeration are flow cytometry (FC) and immunomagnetic bead (IB) isolation. Both quantify CECs accurately, but a direct comparison of both methods has not been reported. We sought to assess the agreement between the two methods in two patient populations, and a group of healthy subjects, with emphasis given to methodological issues. We included 34 patients with acute coronary syndrome (ACS), 60 patients with primary breast cancer (PBC) and 30 healthy controls (HC). We quantified CECs using the IB method [CD146 and FITCUlex europaeus lectin-1] and FC [CD45, CD34 and CD146]. Bland-Altman plots suggested reasonable agreement (<5% of events >2 standard deviations from the mean) between FC and the IB methods for CEC quantification in whole blood in the two disease groups (ACS and PBC), but not among the HCs. There were no statistically significant differences in CEC levels by the two methods amongst all three patient groups. There is reasonable agreement between the FC and the IB methods for mature CEC quantification in whole blood, especially amongst disease groups. The agreement between the two methods appears to weaken in healthy controls, and at lower and higher absolute CEC counts.

Adult↗

Intraoperative findings of cancer in delayed breast reconstruction: a dilemma?

Recurrence of breast cancer discovered at the time of reconstruction is rare. However, with increasing numbers of delayed postmastectomy reconstructions being performed, this scenario may become more common. There are no guidelines on how to manage this dilemma. There are two main issues: the effect on the patient and the effect on the reconstruction itself. The authors present two cases and discuss the factors involved in this difficult decision, along with their recommendations.

Breast Neoplasms↗

Circulating endothelial cells in malignant disease.

Cancer is a disease largely dependent on neoangiogenesis. Cancer neoangiogenesis is often disordered and abnormal, with evidence of coexisting vascular endothelial dysfunction. A novel method of assessing vascular endothelial function in cancer is via the quantification of circulating endothelial cells (CEC). Unusual in healthy individuals, their presence in elevated numbers often indicates substantial vascular endothelial perturbation. Another interesting cell type is the endothelial progenitor cell (EPC), whose numbers increase in the presence of vascular damage. Recent research suggests that EPCs have an important role in tumor vasculogenesis. Another marker being investigated in the context of vascular dysfunction and coagulopathy is the endothelial microparticle (EMP). Thus, CECs, EPCs and EMPs may represent potentially novel methods for evaluating the vascular status of cancer patients. This review will summarize the current position of CECs, EPCs and EMPs in cell biology terms, with particular emphasis on their relationship to malignant disease.

Apoptosis↗

The gold standard for decortication of rhinophyma: combined erbium-YAG/CO2 laser.

Rhinophyma is a benign condition of the nose that often is severely disfiguring and occasionally causes functional problems. A considerable proportion of the patients, with rhinophyma are elderly with chronic medical problems. Electrocautery, heated scalpel, carbon dioxide (CO(2)) laser, argon laser, Weck blade, dermabrasion, cryotherapy, radiotherapy, full-thickness excision, skin graft, flap reconstruction, and cold scalpel have been used either alone or in combination. All these techniques have disadvantages that are resolved by using the combined erbium:yttrium-aluminum-garnet (YAG)/CO(2) laser. The authors present their technique and the results from decortication of rhinophyma using a combined erbium:YAG/CO(2) laser. The technique requires only local anesthesia with a vasoconstrictor. The combination of an efficient vaporization tool consisting of the erbium:YAG laser and the CO(2) coagulation laser provides a nearly bloodless field for accurate sculpting of the nose and produces cosmetically pleasing results.

Carbon Dioxide↗