Perfusion vessels

Figure 13. Calorimetric curves from experiments with 50 mg of human skeletal muscle using different calorimetric techniques. A, Static ampoule used as reaction vessel. B, Perfusion vessel without stirring. C and D, Perfusion vessels with stirring. In all cases the measurement temperature was 37 °C but in experiments A, B, and C sample preparation and storage (1 hour) was at 4 °C. In experiment D the sample was prepared and stored at 37 °C. Adapted from Fagher et al. (1986).

For those interested in cloning reference should be made to Chapter 7. A small scale perfusion vessel is considered in 3.4.3. For many biochemical studies involving incubation of cells with radioisotopes in the presence of drugs, anti-metabolites, hormones etc. small numbers of cells are required and these may conveniently be grown on the bottoms of glass scintillation vials or in the wells of a 6 or 24 well TC plate or even in the wells of a microtitre plate (see Table 3.1). This last method enables 96 replicate cultures to be handled simultaneously but the maximum volume that each well will hold is 0.25 ml. 

A small scale perfusion vessel is available as a sterile pack from Sterilin Ltd. (Appendix 3) for microcinematography. The chamber volume is only 0.4 ml but it may be attached to a heated microscope... 

Treatment planning requires a multi-disciplinary team with clear leadership and accountability to ensure that the screening, diagnostic and treatment procedures are conducted in a seamless fashion. The essential steps include (1) calculation of target liver mass to be infused and tumor burden (2) visceral angiography to map out tumor-perfusing vessels and embolize collaterals (3) assessment of pulmonary shunt (4) determination of the optimal therapeutic dose (5) room preparation (6) radiation monitoring and safety procedures (6) calculation of residual activity and efficiency of delivery. 

Begley, C.M. and Kleis, S.J. The fluid dynamic and shear environment in the NASA/JSC rotating wall perfused-vessel bioreactor. Biotechnol. Bioeng., 70, 32, 2000. 

For studies of anchored cells, modifications need to be made in many cases. For instance, cultures on tenterframes [35] have been inserted into the lOO-cm batch vessel of a Calvet calorimeter [3] and glass plates with cell monolayers on them have been stacked in the ampoules of a Thermometric BAM instrument [36]. In one recent case [37], the stirrer blades of a Thermometric perfusion vessel were modified to act as monolayer plates. It would seem preferable these days to attach the cells to beads that are suspended in a stirred ampoule (see for instance Reference [38]). 

Preliminaiy data for a stirred Thermometric perfusion vessel indicate the same necessity [41]. A 1-cm aliquot of triacetin mixture in a 3-cm sealed glass ampoule had a thermal volume of 0.998 cm. This compared favourably with the previous results obtained elsewhere [40]. A perfusion vessel with the same spacial volume of the calibrant stirred at 30 rev min had a thermal volume of 0.81 cm but at 90 rev min it was 0.99 cm. ... 

Figure 12. Schematic representation of some parts of the calorimetric equipment (a) Simple cylindrical calorimetric vessel (b) a type of perfusion vessel and (c) another type of perfusion vessel with a simplified picture of the perfusion vessel inserted in the measurement position (c,), a section through the sample compartment (C2), and the sample cage (Cj) (Reproduced from Reference [73] with permission).

As stated earlier (Section 3.1.1)), it has always been a calorimetric problem to study the metabolism of cells adherent to a substratum. The obvious solution these days is to use beads in a bioreactor-type vessel. An early application of such a technique was the use of solid Cytodex 1 microcarriers (Pharmacia) to measure the heat production of anchorage-dependent green monkey kidney (Vero) cells [38] in a Thermometric stirred perfusion vessel [95]. As seen in Figure 39, the heat production was proportional to the number of cells assessed by counting in a Biirker chamber the number of nuclei released from cells and stained with a hypotonic solution of citrate containing crystal violet [38]. In recent years, different kinds of microcarriers have been manufactured that are optimised for specific cell types. 

Johansson, R, and I. Wadso (1999). An isothermal microcalorimetric titration/ perfusion vessel equipped with electrodes and spectrophotometer . Thermochimica Acta 342(1-2) 19-29. 

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