Antithrombin III prevents deleterious effects of remote ischemia-reperfusion injury on healing of colonic anastomoses

BACKGROUND: Antithrombin III is known as the most important natural inhibitor of thrombin activity and has been shown to attenuate local harmful effects of ischemia-reperfusion injury in many organs. In recent animal studies, delaying effect of remote organ ischemia-reperfusion injury on healing of intestinal anastomoses has been demonstrated. In this study, we investigated whether antithrombin III reduces deleterious systemic effects of ischemia-reperfusion injury on healing of colonic anastomoses in rats. METHODS: Anastomosis of the left colon was performed in 24 rats that were divided into three groups: sham operated control (group I, n = 8), 30 minutes of intestinal ischemia-reperfusion by superior mesenteric artery occlusion (group II, n = 8), antithrombin III treated group (250 U/kg before and after the ischemia-reperfusion, group III, n = 8). On postoperative day 6, all animals were sacrificed, and bursting pressure and tissue hydroxyproline content of the anastomoses were assessed and compared. RESULTS: On postoperative day 6 the mean bursting pressures were 149.6 +/- 4.8, 69.8 +/- 13.5, and 121.8 +/- 8.7 mm Hg for groups I, II, and III, respectively (P = 0.000). Mean tissue hydroxyproline concentration values were 389.5 +/- 29.6, 263.1 +/- 10.0, and 376.0 +/- 33.8 microg/mg for groups I, II, III respectively (P = 0.005). CONCLUSIONS: This study showed that, antithrombin III treatment significantly prevented the delaying effect of remote organ ischemia-reperfusion injury on anastomotic healing in the colon. Further clinical studies are needed to clarify whether antithrombin may be a useful therapeutic agent to increase the safety of the anastomosis during particular operations where remote organ ischemia-reperfusion injury takes place.     

Value of duplex Doppler ultrasonography in renal colic

OBJECTIVES: The aim of our study was to determine the value of duplex Doppler ultrasonography (DDU) in the patients' evolution with renal colic. The study of the resistive index (RI), difference of the RI (ARI) associated with a DDU intravesical recording (ureteral jets) were compared with renographic findings in renal colic. PATIENTS AND METHODS: Between October 1998 and January 2001 we studied 377 cases with suspected renal colic by intravenous pyelography (IVP), grey-scale ultrasonography and DDU with determination of the RI, the difference between the RI of ipsilateral and contralateral kidneys (ARI) and the amplitude (maximum length of the intravesical ureteral jet), velocity and frequency of the urine bolus. We considered normal values RI < or = 0.70 and ARI < or = 0.06. VP was used as a referee investigation and the ureteral intravesical jets were determined in standard conditions. All patients came to the hospital between 4 and 12 h after the onset of the renal colic. RESULTS: We found four series of patients: 1, acute (complete) obstructed kidney (IVP nonfunctional) and dilatation at normal grey-scale, with normal contralateral kidney (n = 153). In this series we found RI > 0.70 in 87%, RI > 0.06 in 90% and absent ureteral intravesical jet of the obstructed kidney site in 89%; 2, acute (complete) obstructed kidney (IVP nonfunctional) without abnormalities at normal grey-scale, with normal contralateral kidney (n = 57). In this series we found RI > or = 0.70 in 73.5%, deltaRI > 0.06 in 82.5% of patients, absent or asymmetric ureteral intravesical jet in 80.7% of cases; 3, incomplete obstructed kidney (IVP with various degree of ureterohydronephrosis) with normal contralateral kidney (n = 96). In this series we found RI > or = 0.70 in 58.3% and deltaRI > 0.06 in 64.5% of patients, asymmetric ureteral intravesical jets in 74% of cases; 4, normal both kidneys normal IVP) were found in 71 cases (18.8%). In this series we found RI < 0.70 in 80.2%, deltaRI < or = 0.06 in 89% of cases, normal ureteral intravesical jets in 93% of cases. The mean RI was 0.76 (0.05) in 306 obstructed kidneys, significantly higher than the mean RI of 0.62 (0.05) in 448 normal kidneys (P < 0.001). The ARI in patients with obstruction was significantly higher than in patients with normal both kidneys, at 0.08 (0.05) and -0.001 (0.03), respectively (P < 0.001). The RI was sensitive in 75.5% and specific in 92.5% and ARI was sensitive in 80.7% and specific in 95.7% (versus IVP, considered the referee value). The presence of the intravesical ureteral jets of the renal colic side, associated with the values of RI (RI < or = 0.70) and deltaRI (deltaRI < or = 0.06), was followed by spontaneous passage of the stones in 71% of cases. CONCLUSIONS: Renal DDU and consecutively, intravesical evaluation of ureteral jets could detect acute renal obstruction and, as a functional investigation, could have a predictive value regarding the ureteral stones passage. It could replace the IVP, being a sensitive and highly specific test.     

The effect of the psychological status of breast cancer patients on the short-term clinical outcome after mastectomy

PURPOSE: to analyze the effect of anxiety and depression on the postoperative complications and length of hospitalization of patients with breast cancer. Beck's Depression Inventory (BDI) and Hospital Anxiety and Depression Scale (HADS) were filled out by the patients pre-operatively. Patients were asked to rate their pain by the visual analogue scale (VAS) after surgery. Age, seroma volume, day of drain withdrawal, complications, and pathological stages were noted. The median age of 49 patients with the diagnosis of breast cancer was 51 (36-80). There was a significant correlation between the pain score and Beck, HADS, HADS (anxiety) and HADS (depression) (8 hours ; p = 0.021, 0.001, 0.004, 0.005 and 24 hours ; p = 0.005, 0.012, 0.006, 0.120). The mean HADS depression score in those patients with complications was 9.1 +/- 4.2 and that of patients with no complications was 6.6 +/- 3.1 (p = 0.047). The mean hospital stay of patients with a normal HADS score (< 19) was 2.9 +/- 1.1 days, whilst that of patients with an abnormal HADS score was 3.8 +/- 1.2 days (p = 0.016). Patients with abnormal HADS anxiety and abnormal HADS (total) scores had an earlier stage of breast cancer (p = 0.077, p = 0.063). The psychological status of breast cancer patients effects their postoperative recovery period and it is easy to diagnose these patients by some brief questionnaires.     

Long-term results of endoscopic treatment of vesicoureteral reflux with the sub-ureteric injection of calcium hydroxyapatite

Aim To review our long-term results of the sub-ureteric injection of calcium hydroxyapatite in the endoscopic management of vesicoureteral reflux (VUR) in children. Materials and methods A sub-ureteric injection of calcium hydroxyapatite was given to 14 children (23 ureteral units) affected by VUR grades I–V. All children were followed-up with monthly urine cultures, and a renal ultrasound was done on the postoperative 4th week, while the first voiding cysto-urethrogram (VCUG) control was performed on postoperative week 12. The children were followed-up with yearly renal ultrasound and monthly urine cultures, thereafter. Data from the patients’ charts were retrospectively analyzed regarding the outcome of the procedures. Results Mean follow-up time was 52 months (47–60 months). VUR was cured in 47.4% of cases after a single injection. After the second injection the global success rate was 52.1%. Ureteroneocystostomy was performed on seven refluxing ureters of five children unresponsive to sub-ureteric injection therapy. One patient underwent nephroureterectomy because of a non-functioning kidney secondary to ureteral obstruction due to migration of material at the 23rd month postoperatively. Conclusion Although favorable short-term success rates have been reported with the sub-ureteric injection of calcium hydroxyapatite without any side effects, our long-term results showed a low success rate, with the only reported serious morbidity.     

Calpeptin provides functional neuroprotection to rat retinal ganglion cells following Ca2+ influx

Apoptosis of retinal ganglion cells (RGCs) impairs vision in glaucoma patients. RGCs are also degenerated in multiple sclerosis (MS), resulting in loss of visual perception in MS patients. We examined the involvement of calpain and caspase cascades in apoptosis of the rat retinal ganglion cell line RGC-5 following 24 h of exposure to 250 nM ionomycin (IMN) or 300 units/ml interferon-gamma (IFN-gamma) and then evaluated functional neuroprotection with 2 microM calpeptin (CP, a calpain-specific inhibitor). Morphological and biochemical features of apoptosis were detected in RGC-5 cells following exposure to IMN or IFN-gamma. Fura-2 assay determined significant increases in intracellular free [Ca2+] following exposure to IMN or IFN-gamma. Pretreatment with CP for 1 h prevented Ca2+ influx, proteolytic activities, and apoptosis in RGC-5 cells. Western blot analyses showed an increase in activities of calpain and caspase-12, upregulation of Bax:Bcl-2 ratio, release of cytochrome c from mitochondria, and increase in caspase-9 and caspase-3 activities during apoptosis. Increased caspase-3 activity was also confirmed by a colorimetric assay. Activation of caspase-8 and cleavage of Bid to tBid in RGC-5 cells following exposure to IFN-gamma indicated co-operation between extrinsic and intrinsic pathways of apoptosis. Patch-clamp recordings showed that pretreatment with CP attenuated apoptosis and maintained normal whole-cell membrane potential, indicating functional neuroprotection. Taken together, our results demonstrated that Ca2+ overload could be responsible for activation of calpain and caspase cascades leading to apoptotic death of RGC-5 cells and CP provided functional neuroprotection.     

Effects of the abused inhalant toluene on ethanol-sensitive potassium channels expressed in oocytes

Toluene (methylbenzene) is representative of a class of industrial solvents that are voluntarily inhaled as drugs of abuse. Previous data from this laboratory and others have shown that these compounds alter the function of a variety of ion channels including ligand-gated channels activated by ATP, acetylcholine, GABA, glutamate and serotonin, as well as voltage-dependent sodium and calcium channels. It is less clear what effects toluene may have on potassium channels that act to reduce the excitability of most cells. Previous studies have shown that ethanol potentiates the function of both the large conductance, calcium-activated potassium channel (BK) and specific members of the G-protein-coupled inwardly rectifying potassium channels (GirKs). Since toluene and other abused inhalants share many behavioral effects with ethanol, it was hypothesized that toluene would also enhance the function of these channels. This hypothesis was tested using two-electrode voltage-clamp electrophysiology to measure the activity of BK and GirK potassium channel currents expressed in Xenopus laevis oocytes. As reported previously, ethanol potentiated currents in oocytes expressing either BK or GirK2 channels. In contrast, toluene caused a concentration-dependent inhibition of BK channel currents with 3 mM producing approximately 50% inhibition of control currents. Currents in oocytes injected with GirK2 mRNA were also inhibited by toluene while those expressing GirK1/2 and 1/4 channels were minimally affected. In oocytes co-injected with mRNA for GirK2 and the mGluR1a metabotropic receptor, exposure to glutamate potentiated currents evoked by a high-potassium solution. Toluene inhibited these glutamate-activated currents to approximately the same degree as those induced under basal conditions. The results of these studies show that toluene has effects on BK and GirK channels that are opposite to those of ethanol, suggesting that these channels are unlikely to underlie behaviors that these two drugs of abuse share.     

Glutamate leakage from a compartmentalized intracellular metabolic pool and activation of the lipoxygenase pathway mediate oxidative astrocyte death by reversed glutamate transport

Astrocytes have essential roles for neuron survival and function, so that their demise in neurodegenerative insults, such as ischemia, deserves attention. A major event of the cell death cascade in ischemia is the reversed operation of excitatory amino acid transporters (EAAT), releasing glutamate. Cytotoxicity is conventionally attributed to extracellular glutamate accumulation. We previously reported that mimicking such dysfunction by EAAT substrate inhibitors, whose uptake induces glutamate release by heteroexchange, triggers glutathione (GSH) depletion and oxidative death of differentiated astrocytes in culture. Here we demonstrate that astrocyte death, although correlated with glutamate release, is not resulting from high extracellular glutamate-mediated toxicity. L-glutamate per se was gliotoxic only at concentrations much higher than the maximum reached with the potent EAAT substrate inhibitor L-trans-pyrrolidine-2,4-dicarboxylate (PDC), and toxicity was lower. Moreover, high glutamate concentrations offered protection against PDC. Protection was also provided by L-aspartate, which is both transported by EAAT and metabolized into glutamate, and by inhibiting glutamine synthetase, which uses transported glutamate to synthesize glutamine. Neither D-aspartate, a metabolically inert EAAT substrate, nor compounds that can provide glutamate intracellularly but are not EAAT substrates offered protection. Interestingly, only the compounds providing protection prevented PDC-induced GSH depletion. These data strongly suggest that reversed uptake-mediated astrocyte death results from the leakage of glutamate from a compartmentalized intracellular metabolic pool specifically fuelled by EAAT, crucial for preserving GSH contents. In addition, we provide evidence for a minor contribution of the cystine-glutamate antiporter x(c) (-) but a major role of the 5-lipoxygenase pathway in this death mechanism.