Simultaneous colorectal and minor hepatic resections are safe and should be performed for most patients with SCRLM. Due to increased risk of severe morbidity, caution should be exercised before performing simultaneous colorectal and major hepatic resections.

In vivo somatosensory stimuli evoked the release of substance P from primary afferent neurons that terminate in the spinal cord and stimulated endocytosis of substance P receptors in rat spinal cord neurons. The distal dendrites that showed substance P receptor internalization underwent morphological reorganization, changing from a tubular structure to one characterized by swollen varicosities connected by thin segments. This internalization and dendritic structural reorganization provided a specific image of neurons activated by substance P. Thus receptor internalization can drive reversible structural changes in central nervous system neurons in vivo. Both of these processes may be involved in neuronal plasticity.

Studies on cultured cells have shown that agonists induce several types of G protein-coupled receptors to undergo internalization. We have investigated this phenomenon in rat striatum, using substance P (SP)-induced internalization of the SP receptor (SPR) as our model system. Within 1 min of a unilateral striatal injection of SP in the anesthetized rat, nearly 60%o of the SPR-immunoreactive neurons within the injection zone display massive internalization of the SPR-i.e., 20-200 SPR+ endosomes per cell body. Within the dendrites the SPR undergoes a striking translocation from the plasma membrane to endosomes, and these dendrites also undergo a morphological reorganization, changing from a structure of rather uniform diameter to one characterized by large, swollen varicosities connected by thin fibers. In both cell bodies and dendrites the number of SPR+ endosomes returns to baseline within 60 min of SP injection. The number of neurons displaying substantial endosomal SPR internalization is dependent on the concentration of injected SP, and the SP-induced SPR internalization is inhibited by the nonpeptide neurokinin 1 receptor antagonist RP-67,580. These data demonstrate that in the central nervous system in vivo, SP induces a rapid and widespread SPR internalization in the cell bodies and dendrites and a structural reorganization of the dendrites. These results suggest that many of the observations that have been made on the internalization and recycling of G protein-coupled receptors in in vitro transfected cell systems are applicable to similar events that occur in the mammalian central nervous system in vivo.GTP-binding regulatory protein-coupled (G protein-coupled) receptors are a large family of receptors that is widely distributed in the mammalian central nervous system (CNS). This family includes the adrenergic, dopaminergic, and all known peptidergic receptors. Although these receptors exhibit substantial diversity in the ligands with which they interact and the types of neurons and glia that express them, receptors in this family share several common structural and functional features (1, 2). All members of this family contain seven transmembrane domains and activate second-messenger systems via G proteins. Functionally, the majority of receptors in this family undergo desensitization after receptor signaling. Studies on cultured cells transfected with cDNA encoding G protein-coupled receptors indicate that after binding, several types of G protein-coupled receptors undergo phosphorylation, endosomal internalization, dissociation from the ligand in the endosome, dephosphorylation, and finally receptor recycling to the plasma membrane (3-7). Whether G proteincoupled receptors undergo a similar sequence of events in vivo is not known.Substance P (SP) belongs to the tachykinin neuropeptide family which also includes neurokinin A and neurokinin B, and all tachykinins are characterized by the C-terminal sequence -Phe-Xaa-Gly-Leu-Met-NH2 (8). In the CNS, SP is widely distributed and is present in h...

Combined bowel preparation with mechanical cleansing and oral antibiotics results in a significantly lower incidence of incisional surgical site infection, anastomotic leakage, and hospital readmission when compared to no preoperative bowel preparation.