Pumps, perfusion

Lung perfusion. Mice are anaesthetized as above, abdomen opened, and the heart exposed. The right ventricle is cut and punctured in the direction of the right atrium with a blunt needle connected to the peristaltic pump. Perfusion is carried out as before, and the abdominal aorta is cut to allow the flow through. After blood clearing and tissue digestion, lungs are removed and placed in a sterile petri dish. 

Figure 1. Diagram of a perfused heart in the NMR spectrometer with accessory instrumentation. (A) Arrangement of perfusate bath, peristaltic pump, perfusate flow lines with normal (110 cm) and ischemic overflows, pressure transducer with oscilloscope, and pacing stimulator. The vacuum line is for perfusate removal. (B) Expanded view of the perfused heart in the NMR sample tube. The perfusate cannula is positioned in the aorta above the aortic valve. Isovo-lumic left ventricular pressure was measured with a fluid-filled balloon and the hearts were paced with electrodes sewn on the surface of the right ventricle. From Hollis et al. (1978).

Cytochemical Analysis of Na/K Pump Function in Langendorff-perfused Isolated Hearts Effect of Glutathione... 

Shock refers to conditions manifested by hemodynamic alterations (e.g., hypotension, tachycardia, low cardiac output [CO], and oliguria) caused by intravascular volume deficit (hypovolemic shock), myocardial pump failure (cardiogenic shock), or peripheral vasodilation (septic, anaphylactic, or neurogenic shock). The underlying problem in these situations is inadequate tissue perfusion resulting from circulatory failure. 

Preparation of Hepatocytes. In general, the harvesting of hepatocytes from the liver or fiver specimen is performed by tissue perfusion using a peristaltic pump with two... 

In vivo microdialysis is based on the principle of dialysis, the process whereby concentration gradients drive the movement of small molecules and water through a semipermeable membrane. In vivo microdialysis involves the insertion of a small semipermeable membrane into a specific region of a living animal, such as the brain. The assembly that contains this semipermeable membrane is called a probe, which is composed of an inlet and an outlet compartment surrounded by a semipermeable membrane (see O Figure 9-1). Using a microinfusion pump set at a low flow rate (0.2-3 /rL/min), an aqueous solution known as the perfusate is pumped into the inlet compartment of the microdialysis probe. Ideally, the... 

In our laboratory, Xenopus oocytes are placed into a small-volume bath ( 0.5 mL) through which there is a constant flow of perfusion buffer supplied with a gravity-flow drip system (see Figure 14-1). A peristaltic pump (e.g., Minipuls 3, Gilson, Middleton, WI) drives the constant flow of buffer from a reservoir to a... 

The system used by Stevens et al. [79] consisted of an air-lift reactor with an external lamella settler. They did not need to pump the cell suspension through the settler, since free flow convection was achieved by cooling the cell suspension (20 °C) before entering the sedimentation device. As also found by other authors, they could achieve selective retention of viable cells by varying the perfusion rate. 

Himmelfarb et al. [80] introduced spin-filters as a cell retention device for high cell density perfusion cultivations of mammalian cells in suspension. Spin-filters are cylinders with a porous wall, which are placed inside stirred tank bioreactors, either mounted on the impeller shaft or driven by an independent motor (Fig. 5). Perfusate is pumped out from inside the spin-filter at the same... 

The cardiac output or flow of blood normally is so rapid that the distribution of a drug or poison throughout the body is complete within a short period of time. An entire 6 liter supply of blood is pumped through the body at the rate of about once per minute. Some organs and tissues are more highly perfused with blood than others, such as the brain, heart, liver, and kidneys. Adipose (fat) tissue is not as richly endowed. Should a person be in shock or have suffered a myocardial infarction (heart attack), however, the cardiac output can be sharply diminished and a route of drug administration normally used may be circumvented because of poor... 

Dopamine (Intropin) [Vasopressor/Adrenergic] Uses Shortterm use in cardiac decompensation secondary to X contractility when no hypovolemia is present T organ perfusion (at low dose) Action Renal dose 2-5 mcg/kg/min Inotropic dose 5-10 mcg/kg/min Pressor dose >10 mcg/kg/min Dose Adults Peds. 5-20 mcg/kg/min by cont inf, start at 5 and T by 5 mcg/kg/min to 20 mcg/kg/min max to effect (mix 400 mg in 250 mL D5W to make 1600 mcg/mL) (see Table 1-3) Caution [C, ] Contra Pheochromocytoma (adrenal gland tumor), VF, sulfite sensitivity Disp Inj 40, 80, 160 mg/mL, premixed 0.8, 1.6, 3.2 mg/mL SE Tach, vasoconstriction, X BP, HA, N/V, dyspnea Notes >10 mcg/kg/min 1 renal perfusion Interactions T Effects W/ a-blockers, diuretics, ergot alkaloids, MAOIs, BBs, anesthetics, phenytoin 1 effects W/ guanetliidine EMS Correct hypovolemia before use use microdrip set or inf pump check soln- discolored... 

Figure 6.2. Schematic drawing of the microdialysis probe used to sample the concentration of dopamine, DOPAC, 5HIAA and HVA in the extracellular space in rat brains. The fluid is delivered by a pump and passes via the vertical inlet and the inner cannula down to a 3.0 0.5 mm part of the probe, where a semipermeable membrane surrounds the inner cannula (stippled lines). The dialysis process occurs when the fluid passes between the inner cannula and the dialysis membrane. The perfusion medium flows inside the outer cannula to the horizontal outlet and is collected in 20 min (40 pi)...

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