Effectiveness and Safety of Dorsal Root Ganglion Stimulation for the Treatment of Chronic Pain: A Pooled Analysis.

INTRODUCTION: Since it became available in the mid-2010s, dorsal root ganglion (DRG) stimulation has become part of the armamentarium to treat chronic pain. To date, one randomized controlled trial, and several studies of moderate sample size and various etiologies have been published on this topic. We conducted a pooled analysis to investigate the generalizability of individual studies and to identify differences in outcome between chronic pain etiologic subgroups and/or pain location. MATERIALS AND METHODS: One prospective, randomized comparative trial and six prospective, single-arm, observational studies were identified that met pre-defined acceptance criteria. Pain scores and patient-reported outcome (PRO) measures were weighted by study sample sizes and pooled. Safety data are reported in aggregate form. RESULTS: Our analysis included 217 patients with a permanent implant at 12-month follow-up. Analysis of pooled data showed an overall weighted mean pain score of 3.4, with 63% of patients reporting ≥50% pain relief. Effectiveness sub-analyses in CRPS-I, causalgia, and back pain resulted in a mean reduction in pain intensity of 4.9, 4.6, and 3.9 points, respectively. Our pooled analysis showed a pain score for primary affected region ranging from 1.7 (groin) to 3.0 (buttocks) and responder rates of 80% for foot and groin, 75% for leg, and 70% for back. A substantial improvement in all PROs was observed at 12 months. The most commonly reported procedural or device complications were pain at the IPG pocket site, lead fracture, lead migration, and infection. CONCLUSIONS: DRG stimulation is an effective and safe therapy for various etiologies of chronic pain.

Noninvasive measurement of intracranial pressure via the pulsatility index on transcranial Doppler sonography: Is improvement possible?

PURPOSE: We hypothesized that using hemodynamic variables could improve the prediction of intracranial pressure (ICP) from the middle cerebral artery pulsatility index (PI) measured with transcranial Doppler sonography. METHODS: In this prospective study, 39 patients with traumatic brain injury were routinely examined with transcranial Doppler sonography, and the middle cerebral artery PI was calculated. A multivariate model including hematocrit, mean arterial blood pressure, heart rate, and arterial CO2 pressure (PaCO2 ) was evaluated. RESULTS: Thirty-nine comatose patients (16 women and 23 men; age range 18-73 years; median 44 years) were included, and 234 data pairs (consisting of ICP and corresponding PI values) were analyzed. ICP ranged from -3 mmHg to +52 mmHg, and PI from 0.6 to 2.85. We found a significant but weak correlation between PI and the square root of ICP (R(2) between 0.29 and 0.34, p < 0.0001). A slightly stronger correlation was detected when hemodynamic variables were incorporated (R(2) between 0.37 and 0.43). Of these variables, mean arterial blood pressure had the most significant influence. CONCLUSIONS: In this study, PI was not a sufficiently strong predictor of ICP to be used in clinical practice. Its reliability did not improve even when hemodynamic variables were considered. Therefore, we recommend abandoning the use of PI for the noninvasive measurement of ICP in clinical practice.

Experimental comparison of the measurement accuracy of the Licox(®) and Raumedic (®) Neurovent-PTO brain tissue oxygen monitors.

BACKGROUND: Only a few experimental reports are available on the direct comparison of Licox(®) and Raumedic(®)-Neurovent-PTO brain tissue oxygen pressure (P(br)O(2)) monitors. We compared the two systems regarding their measurement properties under experimental in vitro and in vivo conditions. MATERIALS AND METHODS: Eight Licox(®) and Raumedic(®) Neurovent-PTO(®) sensors were tested for 10 min at 37°C, atmospheric pressure, at an oxygen content of 0% and 100% before and after the in vivo test. The same probes were implanted in German landrace pigs, which underwent hepatectomy. The mean P(br)O(2) values were recorded every minute. An O(2) challenge with inhalation of 100% O(2) for 10 min was performed 2 h post-abdominal surgery. RESULTS: At 0% O(2) content values varied from 0.2 to 7 mmHg, at 100% O(2) content from 130 to 165 mmHg. No difference between probes was found. In vivo tests: Raumedic® showed higher P(br)O(2) values (mean +6.3 mmHg, p < 0.0001) compared with Licox®. During O(2) challenge, both probes responded similarly; however, Raumedic(®) had a 10% higher response amplitude (p < 0.005). After explantation there was again no difference between the two sensors. CONCLUSION: Raumedic(®) sensors measured higher P(br)O(2) values. There was no significant difference regarding overall measurement of in vitro accuracy between the two probes, which proved to be robust when used consecutively for longer periods and in different environments.

Is P(br)O (2) pressure reactivity index (ORx) dependent on the type of oxygen probe? An in vivo study.

OBJECTIVE: To evaluate if ORx is dependent on the type of brain tissue O(2) (P(br)O(2)) probe in an in vivo setting. METHODS: In eight German landrace pigs two types of probes were implanted simultaneously in the same cerebral hemisphere. All pigs underwent hepatectomy and received neuromonitoring until death. A LICOX(®) probe CCI.S, representing a Clarke type electrode, was compared with a Raumedic Neurovent PTO, representing an optode. Data were sampled at 50 Hz. Average values were calculated every 30 s. Cerebral perfusion pressure (CPP) was averaged over 30 s. ORx was calculated for each probe. To increase the signal to noise ratio of the ORx, the ORx values, which had been assessed every minute, were averaged over 1 h. RESULTS: The overall measurement time was 145.1 h (8,703 data pairs). Despite a mean difference of 6.2 mmHg (p < 0.0001) in the measured values of P(br)O(2), the mean ORx(licox) was 0.139, mean ORx(raumedic) 0.146 (p = 0.2098). Correlation coefficient of ORx values assessed every minute and every hour was 0.52 and 0.58 respectively. CONCLUSION: Despite this significant difference in absolute values of P(br)O(2) the derived mean ORx values were not different. Similar to the established Licox system, the Raumedic system seems to enable a valid ORx recording.

Correlation of the intracranial pressure to the central venous pressure in the late phase of acute liver failure in a porcine model.

Volume loading is a common method used to ensure adequate circulation. However, in the late phase of acute liver failure complications that often lead to death are cerebral swelling and brainstem edema, which are considered to result from increasing intracranial pressure (ICP). In former studies cerebral venous pressure (CVP) and ICP were reported to be independent entities. Acute liver failure was induced in 25 German land race pigs by acetaminophen intoxication. CVP and ICP were measured continuously. Hydroxyethyl starch solution and noradrenalin were administered to stabilize the circulation at a mean arterial pressure above 60mmHg. There is an increasing correlation in quantity and quality between the CVP and ICP in the last 24 h before exitus. Beginning with a slope of 0.24 (ICP against CVP) and a low correlation coefficient of 0.08. 24h before exitus, this situation remained stable until 16 h to exitus (m = 0.22, r = 0.1). The correlation increased from 16 to 8 h prior to exitus to a slope of m = 0.5 and a correlation of r = 0.3 and remained until exitus. In late acute liver failure it seems therefore clinically reasonable to keep circulation within an adequate range by the use of noradrenalin and to avoid fluid overload.

The values of cerebrovascular pressure reactivity and brain tissue oxygen pressure reactivity in experimental anhepatic liver failure.

BACKGROUND: We investigated in a porcine model of anhepatic acute liver failure (ALF), the value of two parameters describing cerebrovascular autoregulatory capacity, pressure reactivity index (PRx) and brain tissue oxygen pressure reactivity (ORx), regarding their power to predict the development of intracranial hypertension. METHODS: In six pigs, hepatectomy was performed. Only one animal was sham operated. All animals received neuromonitoring including arterial blood pressure, intracranial pressure (ICP), and brain tissue partial oxygen pressure (P(br)O(2)). The average time of neuromonitoring was 31.0 h. Cerebral perfusion pressures (CPP), cerebrovascular pressure reactivity index (PRx) and brain tissue oxygen reactivity index (ORx) were calculated. RESULTS: Perioperative disturbance of AR improved within 4 h after surgery. From 6 to 16 h post hepatectomy, ICP did slowly increase by 4 mmHg from baseline; CPP remained stable around 40 mmHg. PRx and ORx, however, indicated in this period a progressive loss of AR, reflected in a decrease of P(br)O(2) despite unchanged CPP. Beyond 16 h, ICP rose quickly. At CPP levels below 35 mmHg, P(br)O(2) fell to ischemic levels. CONCLUSIONS: The loss of cerebrovascular autoregulatory capacity, indicated by a rise of PRx and ORx precedes the final crisis of uncontrollable intracranial hypertension in this animal model by hours. During this phase cerebral blood flow, as reflected in tissue oxygenation, deteriorates despite unchanged CPP. Monitoring of AR during ALF therefore seems to carry the power to identify a risk for development of critical CBF and intracranial hypertension.

Influence of Spinal Cord Stimulation on Insulin Sensitivity in Chronic Pain Patients.

BACKGROUND AND OBJECTIVE: This prospective, sham-controlled, randomized, cross-over study (NCT03637075), was designed to test the hypothesis that spinal cord stimulation (SCS) for the treatment of pain can also improve glucose metabolism and insulin sensitivity when compared to sham stimulation. METHODS: Ten non-diabetic participants (5 females, mean age 48.8 years) who had an SCS system implanted for the treatment of chronic neuropathic pain were studied. Whilst applying a hyperinsulinemic-euglycemic clamp, sham-stimulation and tonic stimulation were performed for 45 min (n=4) or 60 min (n=6) in each case randomly. The insulin sensitivity index and pain levels were determined. A second investigation, BurstDR stimulation was also conducted and the result was compared to that of sham stimulation (cross-over design). RESULTS: The insulin sensitivity improved significantly under the tonic stimulation when compared to the sham stimulation (p=0.037). BurstDR stimulation independently did not lead to a significantly improved insulin sensitivity compared to that after sham stimulation (p=0.16). We also examined the pain during the test and found no significant difference between sham and tonic stimulation (p=0.687). CONCLUSION: The results of this study show that tonic stimulation used for the treatment of pain could also improve glucose metabolism and insulin sensitivity. Further investigations are required to investigate the clinical relevance of the role of glucose metabolism in diabetic chronic pain participants and its underlying mechanisms.

A simple dummy liver assist device prolongs anhepatic survival in a porcine model of total hepatectomy by slight hypothermia.

BACKGROUND: Advances in intensive care support such as therapeutic hypothermia or new liver assist devices have been the mainstay of treatment attempting to bridge the gap from acute liver failure to liver transplantation, but the efficacy of the available devices in reducing mortality has been questioned. To address this issue, the present animal study was aimed to analyze the pure clinical effects of a simple extracorporeal dummy device in an anhepatic porcine model of acute liver failure. METHODS: Total hepatectomy was performed in ten female pigs followed by standardized intensive care support until death. Five animals (dummy group, n = 5) underwent additional cyclic connection to an extracorporeal dummy device which consisted of a plasma separation unit. The separated undetoxified plasma was completely returned to the pigs circulation without any plasma substitution or exchange in contrast to animals receiving intensive care support alone (control group, n = 5). All physiological parameters such as vital and ventilation parameters were monitored electronically; laboratory values and endotoxin levels were measured every 8 hours. RESULTS: Survival of the dummy device group was 74 ± 6 hours in contrast to 53 ± 5 hours of the control group which was statistically significant (p < 0.05). Body temperature 24 hours after hepatectomy was significantly lower (36.5 ± 0.5°C vs. 38.2 ± 0.7°C) in the dummy device group. Significant lower values were measured for blood lactate (1.9 ± 0.2 vs. 2.5 ± 0.5 mM/L) from 16 hours, creatinine (1.5 ± 0.2 vs. 2.0 ± 0.3 mg/dL) from 40 hours and ammonia (273 ± 122 vs. 1345 ± 700 µg/dL) from 48 hours after hepatectomy until death. A significant rise of endotoxin levels indicated the onset of sepsis at time of death in 60% (3/5) of the dummy device group animals surviving beyond 60 hours from hepatectomy. CONCLUSIONS: Episodes of slight hypothermia induced by cyclic connection to the extracorporeal dummy device produced a significant survival benefit of more than 20 hours through organ protection and hemodynamic stabilisation. Animal studies which focus on a survival benefit generated by liver assist devices should especially address the aspect of slight transient hypothermia by extracorporeal cooling.

Standardized intensive care unit management in an anhepatic pig model: new standards for analyzing liver support systems.

INTRODUCTION: Several anhepatic pig models were developed in the past. Most models suffer from short anhepatic survival times due to insufficient postoperative intensive care unit (ICU) management. The aim of this study was to analyze anhepatic survival time under standardized intensive care therapy in a pig model. METHODS: Eight pigs underwent total hepatectomy after Y-graft interposition between the infrahepatic vena cava and the portal vein to the suprahepatic vena cava. An intracranial probe was inserted for intracranial pressure (ICP) monitoring. Animals received pressure-controlled ventilation under deep narcosis. Vital parameters were continuously recorded. Urinary output, blood gas analysis, haemoglobin, hematocrit, serum electrolytes, lactate, and glucose were monitored hourly, and creatinine, prothrombin time, international normalised ratio, and serum albumin were monitored every 8 hours. Sodium chloride solution 0.9%, hydroxyethyl starch 6%, fresh frozen plasma, and erythrocyte units were used for volume substitution, and norepinephrine was used to prevent severe hypotension. Serum electrolytes and acid-base balance were corrected as required. Antibiotic prophylaxis with ceftriaxon was given daily, as well as furosemide, to maintain diuresis. RESULTS: Postoperative survival was 100% after 24 hours, with a maximum survival of 73 (mean, 58 ± 4) hours. Haemodynamic parameters such as heart rate, mean arterial pressure, and pulse oximetry remained stable during surgical procedures and following anhepatic status due to ICU therapy until escalating at time of death. Deteriorating pulmonary function could be stabilized by increasing oxygen concentration, positive end-expiratory pressure, and maximal airway pressure. Furosemide was used to maintain diuresis until renal failure occurred. ICP started at 15-17 mmHg and increased continuously up to levels of 41-43 mmHg at time of death. All animals died as a result of multiple-organ failure. CONCLUSIONS: Using standardized intensive care management after total hepatectomy, we were able to prolong anhepatic survival over 58 hours without the use of liver support systems. The survival benefit of liver support systems in previous animal studies should be reevaluated against our model.

Extracellular brain ammonia levels in association with arterial ammonia, intracranial pressure and the use of albumin dialysis devices in pigs with acute liver failure.

In acute liver failure (ALF) hyperammonemia plays a mayor role in the pathogenesis of hepatic encephalopathy (HE) but does not always correlate with the severity of mental deterioration and intracranial pressure (ICP). The aim of our study was to evaluate the association with extracellular brain ammonia, ICP and the therapeutical impact of two albumin dialysis devices. ALF was induced by complete hepatectomy in 13 pigs. All pigs were monitored and treated under intensive care conditions until death. Arterial blood and cerebral microdialysis samples were collected and ICP data recorded. Additionally in 5 pigs, standard albumin dialysis and in 3 animals an albumin dialysis prototype was initiated as a tool. Arterial ammonia increased straight after hepatectomy, while extracellular brain ammonia remained on a moderate level 10 h post ALF initiation. After 16 h the brain ammonia reached arterial ammonia levels before plateauing at 1,200 microM, though the arterial ammonia continued to rise. The ICP correlated with the brain ammonia levels. No impact of the different dialysis therapies on neither blood nor brain ammonia levels was observed. In ALF the extracellular brain ammonia revealed a delayed increase compared to arterial ammonia. It correlated strongly with the ICP and could serve as a sensitive marker for HE development. Albumin dialysis did not affect blood or brain ammonia levels.

Do long-term results justify decompressive craniectomy after severe traumatic brain injury?

OBJECT: A decompressive craniectomy can be a life-saving procedure to relieve critically increased intracranial pressure. The survival of a patient is important as well as the subsequent and long-term quality of life. In this paper the authors' goal was to investigate whether long-term clinical results justify the use of a decompressive craniectomy. METHODS: Thirty-three patients (20 males and 13 females) with a mean age of 36.3 years (range 13-60 years) with severe traumatic brain injury (Grades III and IV) and subsequent massive brain swelling were examined. For postoperative assessment the Barthel Index was used. A surgical intervention was based on the following criteria: 1) The intracranial pressure could not be controlled by conservative treatment and constantly exceeded 30 mm Hg (cerebral perfusion pressure<50 mm Hg). 2) Transcranial Doppler ultrasonography revealed only a systolic flow pattern or systolic peaks. 3) There were no other major injuries. 4) The patient was not older than 60 years. RESULTS: One-fifth of all patients died and one-fifth remained in a vegetative state. Mild deficits were seen in 6 of 33 patients. A full rehabilitation (Barthel Index 90-100) was achieved in 13 patients (39.4%). Five patients could resume their former occupation, and another 4 had to change jobs. CONCLUSIONS: Age remains to be one of the most important exclusion factors. Decompressive craniectomy provided good clinical results in nearly 40% of patients who were otherwise most likely to die. Therefore, long-term results justify the use of decompressive craniectomy in this case series.

Dorsal Root Ganglion Stimulation (DRGS) for the Treatment of Chronic Neuropathic Pain: A Single-Center Study with Long-Term Prospective Results in 62 Cases.

BACKGROUND: Dorsal root ganglion stimulation (DRGS) treats discrete, localized areas of neuropathic pain. But there are no long-term results available so far. OBJECTIVES: We studied the long-term outcome of DRGS used in the treatment of chronic neuropathic pain. STUDY DESIGN: A prospective, longitudinal single center investigation. SETTING: Academic medical center in Germany. METHODS: Patients (age >18 years) with chronic neuropathic pain in the hands, back, legs, knees and feet were prospectively examined. After a successful test-trial (duration of 3-14 days, pain decrease > 50%), a permanent generator was implanted. The patients were re-examined after 1 year, 2 years and 3 years. We used the Visual Analogue Scale (VAS), the Pain Disability Index (PDI), the Pain Catastrophizing Scale (PCS), the Brief Pain Inventory (BPI), and, the Beck Depression Inventory (BDI) for our assessments. RESULTS: We included 62 consecutive patients (27 females, 35 males, mean age 56.8 years, with an age range from 28 to 82 years, 62/51 to permanent conversion) during the time period from March 2012 until March 2016. Fifty-one patients had a successful test-trial and a generator was implanted subsequently. Results after 3 years: the VAS dropped from Mdn = 8 to Mdn = 4 (P = 0.0001). The PDI decreased from Mdn = 45 to Mdn = 23 (P = 0.003). The PCS decreased from Mdn = 34 to Mdn = 21 (P = 0.001). The BPI dropped from Mdn = 73 to Mdn = 30 (P = 0.003). The BDI decreased from Mdn = 36 to Mdn = 21 (P = 0.010). Fourteen patients showed complications (27.4%). LIMITATIONS: This study is limited by the small number of patients in the single groups of the different pain locations. CONCLUSION: DRGS may be an effective long-term method of treating discrete, localized areas of chronic neuropathic pain. We would recommend DRGS for the treatment of chronic neuropathic pain in such areas. KEY WORDS: Knee pain, foot pain, hand pain, groin pain, neuromodulation, dorsal root ganglion stimulation, chronic neuropathic pain, paresthesia mapping.

Pathophysiological central nervous system changes in a porcine model of acetaminophen-induced acute liver failure.

BACKGROUND: Critical care management of patients suffering from acute liver failure (ALF) continues to be challenging. Animal models studying the pathophysiological central nervous system alterations during the course of ALF provide an opportunity to improve diagnostic and therapeutic strategies. The aim of this study was to analyse the course of cerebral oxygenation in addition to conventional neuromonitoring during the course of acetaminophen-induced ALF. METHODS: ALF was induced by intrajejunal acetaminophen administration in 20 German landrace pigs. All animals underwent invasive hemodynamic and neuromonitoring and were maintained under standardized intensive care support. Neuromonitoring consisted of continuous intraparenchymatous recording of intracranial pressure and brain partial oxygen pressure. Hemodynamic and ventilation parameters were continuously recorded; laboratory parameters were analysed every eight hours. Mean values were compared using the Wilcoxon test. RESULTS: Acute liver failure occurred in all intoxicated animals after 23±2h, resulting in death due to ALF after further 15±2h. Continuous neuromonitoring was performed in all animals during the whole experiment without observing signs of intracranial haemorrhage. Two hours after manifestation of ALF an increase in brain tissue oxygen (PtiO2) was observed. Brain oxygenation stayed stable until nine hours before death. Intracranial pressure (ICP) remained basically at a plateau level until manifestation of ALF. In the following ten hours a linear and slow increase was observed until five hours before death, followed by a fast and continuous rise in ICP to a final level of 35±1mmHg. Cerebral perfusion pressure (CPP) began to decrease 25h prior to exitus, further decreasing to 18±2mmHg at the end of the experiment. A strong negative linear correlation was found between PtiO2 and ICP (R=0.97). Arterial partial pressure of oxygen (PaO2) below 100mmHg was associated with lower PtiO2 levels. Changes in arterial partial pressure of carbon dioxide (PaC02) did not influence PtiO2 values. Hemoglobin values below 7g/dl were associated with lower PtiO2 values. CONCLUSIONS: The results of our experiments demonstrate that ICP and PtiO2 measurements indicate impending damage well before serious complications occur and their use should be considered in order to protect endangered brain function in the presence of acetaminophen-induced ALF.

Porcine model characterizing various parameters assessing the outcome after acetaminophen intoxication induced acute liver failure.

AIM: To investigate the changes of hemodynamic and laboratory parameters during the course of acute liver failure following acetaminophen overdose. METHODS: Eight pigs underwent a midline laparotomy following jejunal catheter placement for further acetaminophen intoxication and positioning of a portal vein Doppler flow-probe. Acute liver failure was realized by intrajejunal acetaminophen administration in six animals, two animals were sham operated. All animals were invasively monitored and received standardized intensive care support throughout the study. Portal blood flow, hemodynamic and ventilation parameters were continuously recorded. Laboratory parameters were analysed every eight hours. Liver biopsies were sampled every 24 h following intoxication and upon autopsy. RESULTS: Acute liver failure (ALF) occurred after 28 ± 5 h resulted in multiple organ failure and death despite maximal support after further 21 ± 1 h (study end). Portal blood flow (baseline 1100 ± 156 mL/min) increased to a maximum flow of 1873 ± 175 mL/min at manifestation of ALF, which was significantly elevated (P < 0.01). Immediately after peaking, portal flow declined rapidly to 283 ± 135 mL/min at study end. Thrombocyte values (baseline 307 × 103/µL ± 34 × 103/µL) of intoxicated animals declined slowly to values of 145 × 103/µL ± 46 × 103/µL when liver failure occurred. Subsequent appearance of severe thrombocytopenia in liver failure resulted in values of 11 × 103/µL ± 3 × 103/µL preceding fatality within few hours which was significant (P > 0.01). CONCLUSION: Declining portal blood flow and subsequent severe thrombocytopenia after acetaminophen intoxication precede fatality in a porcine acute liver failure model.

Acute liver failure after amanitin poisoning: a porcine model to detect prognostic markers for liver regeneration.

PURPOSE: Over 90 % of fatal mushroom poisoning occurs after ingestion of amanitin-containing species. This study aimed to investigate markers indicating spontaneous liver regeneration in a porcine acute liver failure (ALF) model after α-amanitin intoxication. METHODS: German landrace pigs received either 0.15 mg/kg (n = 5) α-amanitin intravenously or 0.35 mg/kg (n = 5) intraportally. Pigs were invasively monitored and kept under general anesthesia throughout the experiment. Laboratory parameters were analyzed every 8 h. RESULTS: ALF occurred in all animals (10/10) 41 ± 3 h after intoxication. All pigs receiving 0.35 mg/kg α-amanitin and one pig receiving 0.15 mg/kg α-amanitin died 57 ± 16 h after the primary onset of ALF. Four pigs of the 0.15 mg/kg intoxication group recovered spontaneously from ALF after 56 ± 6 h. Starting at 32 h after intoxication, significantly higher values of albumin and total plasma protein could be measured in surviving animals (p < 0.05). A significant temporary increase in the tumor necrosis factor alpha (TNF-α) plasma concentration was detected 40-80 h after intoxication in recovering animals (p < 0.05). CONCLUSIONS: This porcine model represents a novel tool to analyse multiple aspects of liver regeneration following α-amanitin poisoning to allow early discrimination between a fatal course and survivors. Decreased albumin and total plasma protein concentrations in the early intoxication phase indicated a lethal outcome, while an increase in the TNF-α plasma concentration was identified as the earliest prognostic plasma marker detecting liver regeneration a long time before liver function was biochemically and clinically impaired.

The enterohepatic circulation of amanitin: kinetics and therapeutical implications.

BACKGROUND: Amatoxin poisoning induces a delayed onset of acute liver failure which might be explained by the prolonged persistence of the toxin in the enterohepatic circulation. Aim of the study was to demonstrate amanitin kinetics in the enterohepatic circulation. METHODS: Four pigs underwent α-amanitin intoxication receiving 0.35 mg/kg (n=2) or 0.15 mg/kg (n=2) intraportally. All pigs remained under general anesthesia throughout the observation period of 72 h. Laboratory values and amanitin concentration in systemic and portal plasma, bile and urine samples were measured. RESULTS: Amanitin concentrations measured 5h after intoxication of 219±5ng/mL (0.35 mg/kg) and 64±3 (0.15 mg/kg) in systemic plasma and 201±8ng/mL, 80±13ng/mL in portal plasma declined to baseline levels within 24h. Bile concentrations simultaneously recorded showed 153±28ng/mL and 99±58ng/mL and decreased slightly delayed to baseline within 32 h. No difference between portal and systemic amanitin concentration was detected after 24h. CONCLUSIONS: Amanitin disappeared almost completely from systemic and enterohepatic circulation within 24 h. Systemic detoxification and/or interrupting the enterohepatic circulation at a later date might be poorly effective.

Release of regulators of angiogenesis following Hypocrellin-A and -B photodynamic therapy of human brain tumor cells.

Photodynamic therapy (PDT) is an innovative strategy for the treatment of solid neoplasms of the brain. Aside from inducing cell death in tumor cells, PDT induces endothelial cell death and promotes formation of blood clots; however, exact mechanisms that trigger these phenomena remain largely unknown. We now used Western blotting to analyze secretion of regulators of angiogenesis to the supernatants of one glioma, one macrophage, and one endothelial cell line following Hypocrellin-A and -B photodynamic therapy. We observed induction of proangiogenic VEGF (vascular endothelial growth factor) and of antiangiogenic sFlt-1, angiostatin, p43, allograft inflammatory factor-1, and connective tissue growth factor. Release of thrombospondin-1 was diminished in a glioma cell line supernatant. Endostatin release was induced in glioma cells and reduced in macrophages and endothelial cells. These data show that a wide range of antiangiogenic factors are secreted by brain tumor cells following Hypocrellin photochemotherapy. However, VEGF release is also induced thus suggesting both favorable and deleterious effects on tumor outgrowth.