Should cholangiography be part of the management of every patient with percutaneous cholecystostomy?

INTRODUCTION: Percutaneous cholecystostomy (PCC) is a well-established treatment in patients with high surgical risk and those who failed conservative treatment. However, the role of cholangiography in the management of PCC patients is not clear. In our medical center, cholangiography is routinely performed before discharging patient with PCC. We aimed to evaluate the utility of this test and its effect on the patient's management. METHODS: The study included all patients managed with PCC between 2015 to 2017. The patients were divided to those with positive findings and those with no findings. The two groups were compered in demographical and clinical parameters. RESULTS: 119 patients underwent PCC during the study period. Indication for PCC were comorbidities in 73% and failure of conservative treatment in 27%. Cholangiography was performed in 95 patients. Third of the patients had positive findings in their cholangiography. 13 patients had CBD stones, 14 had obstruction of gallbladder and 6 had bile leak. All positive findings required changed in management. CONCLUSION: PCC is a safe procedure. Cholangiography, should be performed in every patient who was managed by PCC since it might change the management in third of the cases.

Interaction of cytotoxic T lymphocytes and guinea pig ventricular myocytes. Pharmacological modulation by blocking K+ currents in cytotoxic T lymphocytes.

Infiltrating cytotoxic T lymphocytes (CTLs) are important immune effectors that damage the myocardium during heart transplant rejection as well as in cardiomyopathy and Chagas' heart disease. We have previously shown that in an in vitro model of murine-derived peritoneal exudate CTL (PEL)-guinea pig ventricular myocyte interaction, PEL induced in conjugated myocytes reduction of resting membrane potential and action potential (AP) amplitude, shortening of AP duration, delayed afterdepolarizations (DADs), and myocyte contracture and destruction. Since these findings indicated that cytotoxicity was largely caused by [Ca2+]i overload, in the present study we tested the hypothesis that blocking the L-type Ca2+ current (ICa,L) in the myocyte will eliminate the trigger for Ca2+ release from intracellular stores and will reduce [Ca2+]i overload and subsequent myocyte deterioration. CoCl2 (3 mmol/L) prevented PEL-induced AP changes, induction of DADs, and myocyte destruction. Since verapamil (2 mumol/L) was ineffective, indicating that the CoCl2 protection was not due to block of ICa,L, we tested whether the different action of these Ca2+ channel blockers was due to their differential effect on the PEL's K+ current (IK), previously shown to participate in lymphocyte activation and cytotoxicity. In agreement with their protective efficacy, CoCl2 but not verapamil blocked IK in PELs, suggesting that this is the mechanism for the protection provided by CoCl2. To support this notion, we tested the effect of the scorpion-derived peptide margatoxin (10 nmol/L), a specific K+ channel blocker in lymphocytes, on PEL-myocyte interaction and on PEL's IK; margatoxin prevented PEL-induced cytotoxicity and also blocked IK in PEL. Based on these findings, an alternative modality for attenuating CTL-induced lymphocytotoxicity is proposed.

Lytic reaction of in vivo primed peritoneal exudate CTL. Induction of high-conductance single channels in the target cell membrane.

CTL, primary effectors in immune responses, deliver a "lethal hit" signal to target cells, causing their destruction. The precise membrane events associated with the lethal hit remain elusive. We investigated the signal(s) mediating destruction of tumor target cells (EL4) by perforin-deficient peritoneal exudate CTL (PEL). We utilized patch clamp techniques to record electrophysiological events associated with the cytolytic interaction of PEL and EL4 in isolated conjugates. PEL-EL4 interaction resulted in induction in EL4 cells, of single channels (followed by EL4 destruction), with a mean conductance of 437 pS and a reversal potential of -1.0 mV, suggestive of nonselective pathways. Similar channels were induced in EL4 cells conjugated with perforin-rich PEL blasts (PEB), by perforin, postnuclear extract from PEL (pnPEL) and from other cytotoxic lymphocytes, but not from noncytolytic lymphocytes. As similar channels were induced by pnPEL in EL4 membrane patches, we propose that these channels result from a direct effect of PEL-derived channel-forming substance(s) on the target cell's membrane. Importantly, postnuclear extracts from perforin-devoid cytotoxic PEL-hybridomas induced similar channels, suggesting the presence of a nonperforin, channel-forming activity in PEL and PEL-hybridomas. Based on the present study, we conclude that the delivery of the lethal hit by cytolytic PEL and PEL-hybridoma is associated with induction in the target cell of high-conductance channels, which most likely mediate its destruction. We propose that these channels are related to the Fas pathway of lymphocytotoxicity.

Diverse firing properties of single motor units in the inner and outer portions of the guinea pig anterior digastric muscle.

Microwire recordings from the histochemically heterogeneous inner compartment of the guinea pig anterior digastric muscle (ADG) revealed tonic firing of single motor units, which were spontaneously active and could also be recruited following orofacial afferent stimulation and during rhythmic jaw movements (RJM). As units with tonic firing were not observed in the homogeneously fast-twitch outer ADG, the tonic units were classified as slow-twitch motor units. Irregular patterns of motor-unit firing at variable frequencies were observed after orofacial stimulation and during RJM in the outer and inner compartments. The irregular firing pattern of units in the fast-twitch outer compartment was characterized by shorter and less variable bursts than that of units in the heterogeneous inner compartment. A phasic, centrally driven firing pattern was observed during RJM in outer and inner ADG units. The firing frequency of some of these units was modulated during the rhythmical bursts. It is suggested that, as in limb muscles, functionally specialized ADG motor units are recruited in an orderly sequence, starting with spontaneously active, slow-twitch units in the inner compartment, continuing with fast-twitch units recruited upon enhancement of the synaptic drive (as in the case of orofacial stimulation), and ending with massive, rhythmical recruitment of slow- and fast-twitch units during RJM.