Experimental study of the potential hazards of surgical smoke from powered instruments

BACKGROUND

Many surgical instruments have been replaced with powered devices in open gastrointestinal and laparoscopic surgery. The production of smoke as a result of vaporization of surgical tissue is inevitable, and exposure to surgical smoke is a long-standing concern. These vapours are potentially hazardous to patients and surgical teams. The present research was designed to compare various surgical devices to determine whether viable cells exist in their surgical smoke.

METHODS

The search for viable cells in surgical smoke was conducted using both in vitro and in vivo experiments. Various cancers were cauterized with electrocautery, radiofrequency ablation and ultrasonic scalpels, and the resulting surgical smoke was aspirated with Transwell(®) membrane; viable cells were sought in the surgical smoke. In an in vivo experiment, samples of SCC7 were cauterized with an ultrasonic scalpel and the sediment from the rinsed Transwell(®) membrane liquid after centrifugation was injected subcutaneously into the lower back of mice.

RESULTS

Viable cells were found only in the smoke from ultrasonic scalpels (in all 25 samples taken 5 cm from the cautery; 2 of 25 samples at 10 cm). Viable cells in the surgical smoke from ultrasonic scalpels implanted in mice grew in 16 of 40 injection sites. Histological and biochemical analyses revealed that these cancer cells were identical to the cancer cells cauterized by the ultrasonic scalpel.

CONCLUSION

Viable tumour cells are produced in the surgical smoke from tumour dissection by ultrasonic scalpel. Surgical relevance Surgical smoke is a byproduct of dissection using a number of powered devices. Hazards to operating room personnel and patients are unclear. This study has shown that use of an ultrasonic dissection device can produce smoke that contains viable tumour cells. Although the model is somewhat artificial, a theoretical risk exists, and measures to evacuate surgical smoke efficiently are important.

Increased metabolic rate and insulin sensitivity in male mice lacking the carcino-embryonic antigen-related cell adhesion molecule 2

AIMS/HYPOTHESIS

The carcino-embryonic antigen-related cell adhesion molecule (CEACAM)2 is produced in many feeding control centres in the brain, but not in peripheral insulin-targeted tissues. Global Ceacam2 null mutation causes insulin resistance and obesity resulting from hyperphagia and hypometabolism in female Ceacam2 homozygous null mutant mice (Cc2 [also known as Ceacam2](-/-)) mice. Because male mice are not obese, the current study examined their metabolic phenotype.

METHODS

The phenotype of male Cc2(-/-) mice was characterised by body fat composition, indirect calorimetry, hyperinsulinaemic-euglycaemic clamp analysis and direct recording of sympathetic nerve activity.

RESULTS

Despite hyperphagia, total fat mass was reduced, owing to the hypermetabolic state in male Cc2(-/-) mice. In contrast to females, male mice also exhibited insulin sensitivity with elevated β-oxidation in skeletal muscle, which is likely to offset the effects of increased food intake. Males and females had increased brown adipogenesis. However, only males had increased activation of sympathetic tone regulation of adipose tissue and increased spontaneous activity. The mechanisms underlying sexual dimorphism in energy balance with the loss of Ceacam2 remain unknown.

CONCLUSIONS/INTERPRETATION

These studies identified a novel role for CEACAM2 in the regulation of metabolic rate and insulin sensitivity via effects on brown adipogenesis, sympathetic nervous outflow to brown adipose tissue, spontaneous activity and energy expenditure in skeletal muscle.

Development of functional human immune system with the transplantations of human fetal liver/thymus tissues and expanded hematopoietic stem cells in RAG2-/-gamma(c)-/- MICE

BACKGROUND

There is an increasing need for suitable animal models for the study of the human immune system and disease. The purpose of this study was to develop a practical in vivo model of human immune cell repopulation using ex vivo expanded human fetal liver-derived CD34(+) hematopoietic stem cells and subrenally coimplanted fetal liver/thymus tissues.

METHODS

Freshly isolated fetal liver-derived CD34(+) hematopoietic stem cells were frozen until injected and ex vivo expanded with various cytokines for 7 days. After fetal liver/thymus tissues were subrenally coimplanted into preirradiated Rag2(-/-)gamma(c)(-/-) mice, frozen and ex vivo expanded CD34(+) cells were injected intravenously. The peripheral blood of the mice was monitored for the detection of human cell engraftment using flow cytometry. Then we confirmed human T-cell function by in vitro function assays.

RESULTS

After fetal liver/thymus tissues were coimplanted into the irradiated Rag2(-/-)gamma(c)(-/-) mice, with frozen and ex vivo expanded CD34(+) hematopoietic stem cells, human cell engraftments were determined using hCD45 and multilineage markers. The cultured cells with the cytokine combination of stem cell factor, thrombopoietin, Flk2/Flk3 ligand (FL), and interleukin-3 showed stable and long-term engraftment compared to other combinations. The ex vivo expanded human fetal liver-derived CD34(+) hematopoietic stem cells, under our culture conditions, accomplished a large volume of expanded cells that were sustained, demonstrating self-renewal of the evaluated markers, which may have indicated long- term repopulation activity.

CONCLUSION

The results of this study demonstrated a practical mouse model of expanded human immune cells especially T cells in Rag2(-/-)gamma(c)(-/-) mice.

Induction of growth hormone release by Pueraria thunbergiana BENTH

Puerariae Radix (PR), Puerariae Flos (PF), and Puerariae Surculus (PS) as well as their constituents were tested for induction of rat growth hormone (rGH) release by both rat pituitary cell culture and in vivo experimentation in order to develop them to novel drugs. Through a calibration curve of the rGH released by addition of rat growth hormone-releasing hormone (rGHRH) to rat pituitary cells, the 70 % ethanol extracts of PR and PS increased rGH release by about 1.6 and 1.7 times as high, respectively, as the control group (264.6 +/- 13.6 pM). However, each puerarin type as a representative constituent of PR in Korea Pharmacopeia (KP) and tectorigenin and an important ingredient of PF were twice as effective as in the control group. The acid hydrolysate of Puerariae Surculus (HPS) increased rGH release concentration-dependently, and its EC (50) was approximately 10.4 microg/ml. The T (max) value for rGH after injection of 20 microg/kg of rGHRH was 10 - 30 min, while the C (max) value was increased by approximately 12-fold compared to the control group (198.2 +/- 25.0 pM) and the AUC (0 - 45) was increased to 10 times the level of the control group (10,840.9 +/- 845.5 min. pM). On the other hand, T (max) for the HPS was 60 min, while C (max) was increased approximately to 5.8 fold compared to control (244.1 +/- 36.4 pM). C (max) for puerarin was 1,028.6 +/- 502.7 pM, that is, approximately 5.2 times as high as the control level. However, tectorigenin (20 microg/kg) was of no statistical significance. Therefore, we suggest that the HPS and puerarin act either on GH secretagogue receptors or on GHRH receptor of somatotrophin as possible agonists or an inhibitor on somatostatin receptor to release rGH, respectively.

Hydrothermal synthesis and magnetic behavior of a novel layered coordination polymer generated from manganese(II) adipate

A novel, two-dimensional organic/inorganic coordinate polymers, Mn2(H2O)[O2C(CH2)4CO2]2, was synthesized as single crystals by the hydrothermal reaction of MnCl2 with adipic acid in the presence of base and characterized by single-crystal X-ray diffraction, infrared spectroscopy, thermal analysis, and SQUID magnetic measurement. It crystallized in the monoclinic space group C2/c(No. 15), with a = 21.671(2) A, b = 7.6023(7) A, c = 9.1452(9) A, beta = 108.849(7) A, Z = 4. The title compound presents a structure constituted by the stacking along [100] of MnO6 layers interleaved with adipate ions. The novel feature of the anionic layer is that it contains close-packed trans alkyl chains residing in an extended framework. Magnetization measurement shows this compound is antiferromagnetic below 15 K.

Epstein-Barr virus-associated lymphoproliferative skin lesion with recurrent necrotic papulovesicles of the face

A 24-year-old man showed recurrent necrotic papulovesicles of the face. The cutaneous lesions started with erythema, followed by vesicles, necrosis, and crusting, and leaving depressed scars. Light avoidance did not prevent the development of the lesions. Histologic examination revealed lymphoproliferative lesions confined to the skin. Latent Epstein-Barr virus (EBV) infection was detected in the lymphoid cells from the skin lesions by in situ hybridization. A moderate to high dosage of corticosteroids suppressed the development of new skin lesions, but relapses occurred when these systemic corticosteroids were tapered.

Development of a new moving-actuator type electromechanical total artificial heart

A new type of electromechanical total artificial heart based on a moving-actuator mechanism was developed to decrease the total pump size and to improve the fitting characteristic of the pump to atrial remnants and arterial vessels. The blood pump consists of three major parts: right and left blood sacs and a moving pump actuator between two sacs. The total weight is 810 g and the volume of the pump is 770 ml. The actuator rolls back and forth on a circular track, producing alternating blood ejection. The pump performance was evaluated in mock circulation and animal implant experiments. The pump was implanted for 100 h in a calf (approximately 100 kg) with a stable hemodynamic state until accidental (electrical short circuit) death.