Unmethylated Insulin DNA Is Elevated After Total Pancreatectomy With Islet Autotransplantation: Assessment of a Novel Beta Cell Marker.

Beta cell death may occur both after islet isolation and during infusion back into recipients undergoing total pancreatectomy with islet autotransplantation (TPIAT) for chronic pancreatitis. We measured the novel beta cell death marker unmethylated insulin (INS) DNA in TPIAT recipients before and immediately after islet infusion (n = 21) and again 90 days after TPIAT, concurrent with metabolic functional assessments (n = 25). As expected, INS DNA decreased after pancreatectomy (p = 0.0002). All TPIAT recipients had an elevated unmethylated INS DNA ratio in the first hours following islet infusion. In four samples (three patients), INS DNA was also assessed immediately after islet isolation and again before islet infusion to assess the impact of the isolation process: Unmethylated and methylated INS DNA fractions both increased over this interval, suggesting death of beta cells and exocrine tissue before islet infusion. Higher glucose excursion with mixed-meal tolerance testing was associated with persistently elevated INS DNA at day 90. In conclusion, we observed universal early elevations in the beta cell death marker INS DNA after TPIAT, with pronounced elevations in the islet supernatant before infusion, likely reflecting beta cell death induced by islet isolation. Persistent posttransplant elevation of INS DNA predicted greater hyperglycemia at 90 days.

Sitagliptin Treatment After Total Pancreatectomy With Islet Autotransplantation: A Randomized, Placebo-Controlled Study.

Insulin independence after total pancreatectomy and islet autotransplant (TPIAT) for chronic pancreatitis is limited by a high rate of postprocedure beta cell apoptosis. Endogenous glucagon-like peptide-1 and glucose-dependent insulinotropic peptide, which are increased by dipeptidyl peptidase 4 inhibitor therapy (sitagliptin) may protect against beta cell apoptosis. To determine the effect of sitagliptin after TPIAT, 83 adult TPIAT recipients were randomized to receive sitagliptin (n = 54) or placebo (n = 29) for 12 months after TPIAT. At 12 and 18 months after TPIAT, participants were assessed for insulin independence; metabolic testing was performed with mixed meal tolerance testing and frequent sample intravenous glucose tolerance testing. Insulin independence did not differ between the sitagliptin and placebo groups at 12 months (42% vs. 45%, p = 0.82) or 18 months (36% vs. 44%, p = 0.48). At 12 months, insulin dose was 9.0 (standard error 1.7) units/day and 7.9 (2.2) units/day in the sitagliptin and placebo groups, respectively (p = 0.67) and at 18 months 10.3 (1.9) and 7.1 (2.6) units/day, respectively (p = 0.32). Hemoglobin A1c levels and insulin secretory measures were similar in the two groups, as were adverse events. In conclusion, sitagliptin could be safely administered but did not improve metabolic outcomes after TPIAT.

Successful Application of Closed-Loop Artificial Pancreas Therapy After Islet Autotransplantation.

Total pancreatectomy with islet autotransplantation (TPIAT) may relieve the pain of chronic pancreatitis while avoiding postsurgical diabetes. Minimizing hyperglycemia after TPIAT limits beta cell apoptosis during islet engraftment. Closed-loop (CL) therapy combining an insulin pump with a continuous glucose monitor (CGM) has not been investigated previously in islet transplant recipients. Our objective was to determine the feasibility and efficacy of CL therapy to maintain glucose profiles close to normoglycemia following TPIAT. Fourteen adult subjects (36% male; aged 35.9 ± 11.4 years) were randomized to subcutaneous insulin via CL pump (n = 7) or multiple daily injections with blinded CGM (n = 7) for 72 h at transition from intravenous to subcutaneous insulin. Mean serum glucose values were significantly lower in the CL pump group than in the control group (111 ± 4 vs. 130 ± 13 mg/dL; p = 0.003) without increased risk of hypoglycemia (percentage of time <70 mg/dL: CL pump 1.9%, control 4.8%; p = 0.46). Results from this pilot study suggest that CL therapy is superior to conventional therapy in maintaining euglycemia without increased hypoglycemia. This technology shows significant promise to safely maintain euglycemic targets during the period of islet engraftment following islet transplantation.

Proposed thresholds for pancreatic tissue volume for safe intraportal islet autotransplantation after total pancreatectomy.

The simple question of how much tissue volume (TV) is really safe to infuse in total pancreatectomy-islet autotransplantation (TP-IAT) for chronic pancreatitis (CP) precipitated this analysis. We examined a large cohort of CP patients (n = 233) to determine major risk factors for elevated portal pressure (PP) during islet infusion, using bivariate and multivariate regression modeling. Rates of bleeding requiring operative intervention and portal venous thrombosis (PVT) were evaluated. The total TV per kilogram body weight infused intraportally was the best independent predictor of change in PP (ΔPP) (p < 0.0001; R(2) = 0.566). Rates of bleeding and PVT were 7.73% and 3.43%, respectively. Both TV/kg and ΔPP are associated with increased complication rates, although ΔPP appears to be more directly relevant. Receiver operating characteristic analysis identified an increased risk of PVT above a suggested cut-point of 26 cmH2O (area under the curve = 0.759), which was also dependent on age. This ΔPP threshold was more likely to be exceeded in cases where the total TV was >0.25 cm(3)/kg. Based on this analysis, we have recommended targeting a TV of <0.25 cm(3)/kg during islet manufacturing and to halt intraportal infusion, at least temporarily, if the ΔPP exceeds 25 cmH2O. These models can be used to guide islet manufacturing and clinical decision making to minimize risks in TP-IAT recipients.

Metabolic assessment prior to total pancreatectomy and islet autotransplant: utility, limitations and potential.

Islet autotransplant (IAT) may ameliorate postsurgical diabetes following total pancreatectomy (TP), but outcomes are dependent upon islet mass, which is unknown prior to pancreatectomy. We evaluated whether preoperative metabolic testing could predict islet isolation outcomes and thus improve assessment of TPIAT candidates. We examined the relationship between measures from frequent sample IV glucose tolerance tests (FSIVGTT) and mixed meal tolerance tests (MMTT) and islet mass in 60 adult patients, with multivariate logistic regression modeling to identify predictors of islet mass ≥2500 IEQ/kg. The acute C-peptide response to glucose (ACRglu) and disposition index from FSIVGTT correlated modestly with the islet equivalents per kilogram body weight (IEQ/kg). Fasting and MMTT glucose levels and HbA1c correlated inversely with IEQ/kg (r values -0.33 to -0.40, p ≤ 0.05). In multivariate logistic regression modeling, normal fasting glucose (<100 mg/dL) and stimulated C-peptide on MMTT ≥4 ng/mL were associated with greater odds of receiving an islet mass ≥2500 IEQ/kg (OR 0.93 for fasting glucose, CI 0.87-1.0; OR 7.9 for C-peptide, CI 1.75-35.6). In conclusion, parameters obtained from FSIVGTT correlate modestly with islet isolation outcomes. Stimulated C-peptide ≥4 ng/mL on MMTT conveyed eight times the odds of receiving ≥2500 IEQ/kg, a threshold associated with reasonable metabolic control postoperatively.

Increased platelet:RBC ratios are associated with improved survival after massive transfusion.

BACKGROUND: Several recent military and civilian trauma studies demonstrate that improved outcomes are associated with early and increased use of plasma-based resuscitation strategies. However, outcomes associated with platelet transfusions are poorly characterized. We hypothesized that increased platelet:red blood cells (RBC) ratios would decrease hemorrhagic death and improve survival after massive transfusion (MT). METHODS: A transfusion database of patients transported from the scene to 22 Level I Trauma Centers over 12 months in 2005 to 2006 was reviewed. MT was defined as receiving ≥ 10 RBC units within 24 hours of admission. To mitigate survival bias, 25 patients who died within 60 minutes of arrival were excluded from analysis. Six random donor platelet units were considered equal to a single apheresis platelet unit. Admission and outcome data associated with the low (>1:20), medium (1:2), and high (1:1) platelet:RBC ratios were examined. These groups were based on the median value of the tertiles for the ratio of platelets:RBC units. RESULTS: Two thousand three hundred twelve patients received at least one unit of blood and 643 received an MT. Admission vital signs, INR, temperature, pH, Glasgow Coma Scale, Injury Severity Score, and age were similar between platelet ratio groups. The average admission platelet counts were lower in the patients who received the high platelet:RBC ratio versus the low ratio (192 vs. 216, p = 0.03). Patients who received MT were severely injured, with a mean (± standard deviation) Injury Severity Score of 33 ± 16 and received 22 ± 15 RBCs and 11 ± 14 platelets within 24 hours of injury. Increased platelet ratios were associated with improved survival at 24 hours and 30 days (p < 0.001 for both). Truncal hemorrhage as a cause of death was decreased (low: 67%, medium: 60%, high: 47%, p = 0.04). Multiple organ failure mortality was increased (low: 7%, medium: 16%, high: 27%, p = 0.003), but overall 30-day survival was improved (low: 52%, medium: 57%, high: 70%) in the high ratio group (medium vs. high: p = 0.008; low vs. high: p = 0.007). CONCLUSION: Similar to recently published military data, transfusion of platelet:RBC ratios of 1:1 was associated with improved early and late survival, decreased hemorrhagic death and a concomitant increase in multiple organ failure-related mortality. Based on this large retrospective study, increased and early use of platelets may be justified, pending the results of prospective randomized transfusion data.

Human islet isolation for autologous transplantation: comparison of yield and function using SERVA/Nordmark versus Roche enzymes.

Islet autotransplantation (IAT) is used to preserve as much insulin-secretory capacity as possible in patients undergoing total pancreatectomy for painful chronic pancreatitis. The enzyme used to dissociate the pancreas is a critical determinant of islet yield, which is correlated with posttransplant function. Here, we present our experience with IAT procedures to compare islet product data using the new enzyme SERVA/Nordmark (SN group; n = 46) with the standard enzyme Liberase-HI (LH group; n = 40). Total islet yields (mean +/- standard deviation; 216,417 +/- 79,278 islet equivalent [IEQ] in the LH group; 227,958 +/- 58,544 IEQ in the SN group; p = 0.67) were similar. However, the percentage of embedded islets is higher in the SN group compared to the LH group. Significant differences were found in pancreas digestion time, dilution time, and digested pancreas weight between the two groups. Multivariate linear regression analysis showed the two groups differed in portal venous pressure changes. The incidence of graft function and insulin independence was not different between the two groups. The SN and LH enzymes are associated with similar outcomes for IAT. Further optimization of the collagenase/neutral protease ratio is necessary to reduce the number of embedded islets obtained when using the SN enzyme.

Changes in vasopressin use and outcomes in surgical intensive care unit patients with septic shock.

INTRODUCTION: This study compares recent vasopressin use and outcomes to our early practice when vasopressin was introduced for septic shock. METHODS: Charts of Surgical Intensive Care Unit (SICU) patients receiving vasopressin for septic shock in 2005-2006 (05-06 cohort,) were retrospectively reviewed. Demographics, APACHE II, hemodynamic variables, and vasoactive drug data were compared to a similar 1999-2000 cohort (99-00 cohort). Statistical analysis included general linear model, Chi-square, t-test, and Cox-regression (p < 0.05 considered significant). RESULTS: Thirty-one SICU patients in the 05-06 cohort and twenty patients in the 99-00 cohort met study criteria. Age, weight, gender, intensive care length of stay and vasopressin treatment duration were similar in the two groups. APACHE II (23 +/- 7 versus 34 +/- 9), baseline vasopressin dose (2.2 +/- 1.4 units/hour versus 5.3 +/- 6.7 units/hour), and SICU survival rate (45% versus 15%) significantly changed between the two time periods (p < 0.01). The mean arterial pressure increased significantly from baseline at all measured time points in both groups (p < 0.05). Vasopressin and dopamine doses were significantly lower in the 05-06 cohort versus the 99-00 cohort (p < 0.05). By Cox regression analysis the survival function adjusted for APACHE II was significantly different between groups. CONCLUSIONS: Vasopressin is recently used at lower doses and in less severe septic shock. Patients recently treated with vasopressin have a higher SICU survival rate than the survival rate when vasopressin was first introduced for septic shock.

The prognostic significance of glutamic acid decarboxylase antibodies in patients with chronic pancreatitis undergoing total pancreatectomy with islet autotransplantation.

AIM: Islet autotransplantation (IAT) is considered a 'non-immune' model of islet transplant, with no risk for autoimmune-mediated beta cell loss, but we have previously observed de novo type 1 diabetes in one total pancreatectomy with islet autotransplantation (TPIAT) recipient. We aimed to investigate the clinical significance of glutamic acid decarboxylase antibodies (GADA), as a sensitive marker for autoimmune diabetes mellitus (DM), in patients with chronic pancreatitis undergoing TPIAT. METHODS: We identified 9 patients undergoing TPIAT with elevated GADA pre-TPIAT (8 non-diabetic and 1 with C-peptide positive DM), otherwise demographically similar to GADA negative TPIAT recipients (n=341). Metabolic and clinical measures related to islet cell function were recorded both before and after TPIAT. RESULTS: None of the 9 TPIAT patients achieved insulin independence after surgery, vs. 33% of GADA negative patients (n=318 with 1-yr follow-up). The two patients with the highest titters of GADA (>250 IU/mL) both experienced islet graft failure, despite normoglycaemia pre-TPIAT and high islet mass transplanted (5276 and 9378 IEQ per kg), with elevated HbA1c levels post-TPIAT (8.3%, 9.6%). The remaining 7 seven were insulin dependent with partial graft function and HbA1c levels <7%. CONCLUSION: Insulin dependence was more frequent in 9 patients with elevated GADA prior to TPIAT than in GADA negative TPIAT recipients, with graft failure in 2 cases. We speculate that beta-cell autoimmunity may occur in a small subset of TPIAT recipients and that beta cell antibody testing prior to TPIAT may be warranted to identify individuals at higher risk for insulin dependence.

The effects of intraoperative administration of OKT3 during renal transplantation.

The use of the monoclonal antibody OKT3 for induction immunosuppression in renal transplantation is increasing--however, the safety of intraoperative administration continues to be questioned because of first-dose effects. The current study was designed to examine the effects of intraoperative administration of OKT3 on the cardiovascular and pulmonary systems in 161 consecutive renal transplant recipients. Patients receiving OKT3 intraoperatively during renal transplant (99 cadaver recipients) were compared with 62 patients not administered the drug (31 cadaver, 25 living-related-donor, 6 living-nonrelated donor). Intraoperative airway pressure (highest, average), O2 saturation (SaO2), temperature, blood pressure changes, cardiac rhythm, and bronchospasm were compared in these two groups. Significant physiologic changes noted in the group receiving OKT3 included increased temperature (both intraoperative and postoperative), decreased SaO2 (postoperative), and increased FiO2 (postoperative). Despite these differences, no clinically significant changes were noted in the group receiving OKT3. OKT3 induction given at the time of surgery was associated with a significantly increased one- and three-year graft function. This study demonstrates that first-dose administration of OKT3 intraoperatively during renal transplantation is safe and effective.

Near-infrared spectroscopy measurement of regional tissue oxyhemoglobin saturation during hemorrhagic shock.

Adequate resuscitation of patients from shock states depends on restoration of oxygen delivery (DO2) to tissues. Direct measurement of systemic DO2 during shock states requires invasive techniques such as pulmonary artery catheterization. These experiments were performed to examine the ability of near-infrared spectroscopy (NIRS), to measure regional tissue oxygenation in a large-animal model of hemorrhagic shock, and to compare these measures to global measures of oxygen delivery. Splenectomized female pigs (n = 11) were anesthetized, instrumented, and monitored. NIRS probes were placed on the leg, in the stomach via nasogastric tube, and on the liver during laparotomy. Hemorrhagic shock was induced by phlebotomy of 28% of blood volume. After 1 hour, resuscitation was with shed blood and crystalloid until cardiac output plateaued. Measurements of physiologic parameters, blood gases, lactate, intramucosal pH, and NIRS values for regional tissue hemoglobin oxygen saturation (StO2), and cytochrome a,a3 redox state were recorded at intervals throughout the experiment. Tissue oxygenation as measured by oxyhemoglobin saturation and cytochrome a,a3 redox (NIRS) correlated with measures of systemic DO2 throughout the experiment. The liver probe demonstrated blunted changes in tissue oxygenation suggesting relatively protected circulation. Intramucosal pH did not correlate well with DO2. Regional tissue oxygenation as measured by NIRS shows excellent correlation with global oxygen delivery. NIRS may allow estimation of systemic oxygen delivery using rapid non-invasive techniques.

Near-infrared and nuclear magnetic resonance spectroscopic assessment of tissue energetics in an isolated, perfused canine hind limb model of dysoxia.

This controlled laboratory study examined the efficacy of near-infrared spectroscopy (NIRS) and 31P-nuclear magnetic resonance (NMR) spectroscopy in measuring regional tissue oxygenation in a isolated, perfused hind limb model of tissue dysoxia. Isolated hind limb perfusion was carried out in 20 mongrel dogs and oxygen delivery was varied by manipulating either hemoglobin concentration, oxygen saturation, or flow. Hind limbs from anesthetized mongrel dogs (n = 20) were separated and isolated perfusion performed. NIRS probes for recording relative O2 saturation of tissue hemoglobin (HbO2) and cytochrome a,a3 and NMR probes for measuring 31P-high energy phosphates were placed over the limb. Measurements of physiologic parameters, blood gases, lactate, NIRS values for HbO2 and cytochrome a,a3 redox state, and 31P-phosphate levels were recorded at set intervals throughout the experiment. Measures of tissue oxygen consumption (VO2) correlated with tissue oxygenation as measured by HbO2 and cytochrome a,a3 redox state (NIRS), as well as by 31P-high energy phosphate levels (NMR) throughout the experiment. Delivery-dependent tissue oxygenation was detected at a higher DO2 by NIRS than by VO2 or NMR. Tissue oxygenation as measured by NIRS and NMR shows excellent correlation with oxygen delivery in an isolated, perfused model of shock. NIRS may allow early detection of tissue dysoxia using rapid non-invasive techniques.

Morphine directs T cells toward T(H2) differentiation.

BACKGROUND: Failure of cell-mediated immunity is thought to increase the morbidity and mortality rates after trauma and major surgical procedures and to be the result, in part, of a redirection of CD4(+) T cells toward T(H2) differentiation. We tested the hypothesis that morphine treatment after injury promotes T(H2) differentiation of precursor T cells through the mu-opioid receptor. METHODS: Human peripheral blood mononuclear cells (PBMCs) or splenocytes from either wild type or mu-opioid receptor knock-out mice were treated in vitro with either vehicle or morphine and then stimulated with anti-CD3/anti-CD28. The supernatant was assayed for T(H1) (interleukin-2 [IL-2], interferon gamma [IFN gamma]) and T(H2) (IL-4, IL-5) cytokines (enzyme-linked immunosorbent assay). Morphine regulation of IL-4 transcription was investigated in PBMCs (IL-4 messenger RNA, nuclear factor of activated T-cells) and Jurkat T cells transfected with a murine IL-4 promoter-luciferase construct. Morphine-induced nuclear factor of activated T-cell (NFAT) binding was assayed with the electromobility shift assay in Jurkat T cells. RESULTS: Morphine treatment of PBMCs decreases IL-2 and IFN gamma and increases IL-4 and IL-5 as a function of morphine concentration. Morphine treatment in wild type splenocytes inhibited IFN gamma and stimulated IL-4 protein synthesis. Changes in cytokine synthesis were abolished in mu-opioid receptor knockout mice. Morphine treatment increases IL-4 messenger RNA accumulation in PBMCs and increases IL-4 promoter activity in Jurkat T cells. Morphine increases NFAT nuclear protein binding to an NFAT DNA response element. CONCLUSIONS: We conclude that morphine treatment promotes T(H2) differentiation through a mu-opioid receptor mechanism and that morphine treatment increases IL-4 transcription, in part, through an NFAT mechanism.

Third-generation cephalosporins and vancomycin as risk factors for postoperative vancomycin-resistant enterococcus infection.

OBJECTIVE: To examine use of third-generation cephalosporins (3GCs) alone and in association with vancomycin hydrochloride as a risk factor for vancomycin-resistant enterococcus (VRE) infection in surgical patients. DESIGN: Case-control retrospective study analyzing antibiotic use in the 30 days preceding culture of VRE or vancomycin-sensitive enterococcus from an infected site. SETTING: A large tertiary care teaching hospital. PATIENTS: Surgical inpatients with VRE infections between September 3, 1993, and January 29, 1997, were matched with patients with vancomycin-sensitive enterococcus infections. Matches were based on surgical procedure, initial infection site, and immunosuppression. Matches were found for 32 of 50 surgical patients with VRE. Twenty matched pairs of patients were recipients of solid organ transplants. MAIN OUTCOME MEASURES: Multivariate logistic regression analysis was done to examine 3GCs and vancomycin as risk factors for VRE infection. Univariate analysis of use of other antibiotic agents and demographic data was also performed. RESULTS: Multivariate analysis showed significant differences in the use of 3GCs both alone and concurrently with vancomycin. Univariate analysis also showed higher use of metronidazole, concurrent vancomycin and metronidazole, concurrent vancomycin and ceftazidime, and all antibiotics combined in patients with VRE infections. CONCLUSIONS: This matched control study showed that use of 3GCs, alone (P=.05) or concurrently with vancomycin (P=.05), was a risk factor for VRE infection in surgical patients. Judicious administration of third-generation antibiotics is warranted in surgical patients with other risk factors for VRE.

Six years of surgical wound infection surveillance at a tertiary care center: review of the microbiologic and epidemiological aspects of 20,007 wounds.

HYPOTHESES: (1) Antibiotic restriction policies result in alteration of microbiologic features of surgical site infections (SSIs) and (2) reported SSI rates are underestimated when postdischarge surveillance is not included in SSI surveillance efforts. DESIGN: Retrospective analysis of prospectively collected SSI surveillance data. PATIENTS AND METHODS: We compared initial microbial isolates from SSIs between (1) January 1, 1993, and December 31, 1995, and (2) January; 1, 1996, and December 31, 1998. Antibiotic restriction policies were implemented at Fairview-University Medical Center, Minneapolis, Minn, on March 1, 1995. For the combined periods (January 1, 1993, to December 31, 1998), we determined SSI rates for 20007 operations according to the extent of bacterial contamination at surgery (wound class). Then, we analyzed SSI rates for 10559 of these operations (selected based on availability of Anesthesia Society of America score and type of procedure) using the surgical wound risk index (wound class, Anesthesia Society of America score, and length of operation). We categorized SSI rates by 17 procedures for comparison with SSI rates reported by 286 hospitals that contributed data confidentially and voluntarily to the National Nosocomial Infections Surveillance System in 1998. We compared SSI rates with and without postdischarge surveillance. RESULTS: Coagulase-negative staphylococcus and group D enterococcus were the 2 most frequent isolates before and after antibiotic restriction policies were implemented. Candida albicans isolates decreased from 7.9% (1993-1995) to 6.5% (1996-1998; P=.46). Methicillin-resistant Staphylococcus aureus (1.8% of isolates) and vancomycin-resistant enterococcus (2.4% of isolates) organisms were first identified between 1996 and 1998. Our SSI rates were 2.6% for class I wounds, 3.6% for class II wounds, and 10.5% for class III/IV wounds; 53.9% of SSIs were identified after hospital discharge. CONCLUSIONS: Antibiotic restriction policies did not alter the microbial spectrum of SSIs during the observation period. Reporting SSI rates in the absence of postdischarge surveillance dramatically underestimates actual SSI rates, especially in tertiary care hospitals that provide care for large populations of elderly and immunosuppressed patients.

Evaluation of the effect of culture matrices on induction of CYP3A isoforms in cultured porcine hepatocytes.

Several bioartificial liver devices have been developed as temporary therapy for patients suffering from fulminant hepatic failure. Some of these devices contain porcine hepatocytes entrapped in collagen matrices. In order to improve the function of these BAL devices, there exists a need to optimize metabolic function of cultured hepatocytes. The goal of these investigations was to evaluate the effect of altering culture conditions on rifampin-mediated induction of CYP3A isoforms in cultured porcine hepatocytes. Midazolam metabolism was compared in porcine hepatocytes cultured in a monolayer configuration on collagen gels, in a sandwich configuration between collagen gels and a Matrigel overlay, and in spheroidal cultures. The effect of culture conditions was evaluated, by measuring CYP3A-mediated metabolism of midazolam and by immunoblotting to detect CYP3A proteins, in control cultures and in rifampin-treated cultures. Results obtained by normalizing the metabolism rate data to cell numbers (based on DNA content) present at the end of the culture experiment, showed that there was no difference between the different culture conditions tested. Our results suggest that culturing porcine hepatocytes as spheroids or in a sandwich configuration between collagen and Matrigel, offers no advantage in terms of CYP3A-mediated metabolic function on a per cell basis compared to culturing on collagen gels.

The future. Monitoring cellular energetics.

Current monitoring of critically ill patients uses measurement of global parameters such as oxygen consumption and lactate levels. With development of new monitoring technologies, it may be possible to monitor patients on an organ or tissue level, allowing manipulation of specific organ or tissue perfusion. Potentially useful techniques for monitoring tissue energetics in the future include NIR and NMR spectroscopy. However, both of these techniques are currently limited in their usefulness due to technical factors; NIR by its inability to monitor "silent" metabolically active organs and NMR by its cost, size, and interference of magnetic fields with electronic equipment. Both of these techniques may be useful for identification of dysoxia or oxygen-limited mitochondrial turnover. Experimental evidence suggests that organs in the septic state are more sensitive to dysoxia. Implications for the care of the patient with sepsis include possible decreased tolerance to factors leading to dysoxia, such as hypoxemia, hemodilution, or ischemia.

Splenic abscess 10 years after splenic trauma: a case report.

Splenic abscess is an uncommon complication of splenic trauma. Splenic abscess presents within several months of the trauma. We report a case of a splenic abscess 10 years after trauma and review the current understanding of splenic abscesses.

Traumatic hemorrhage of occult pheochromocytoma: a case report and review of the literature.

Pheochromocytoma usually presents with gradual onset and mild to moderate symptoms, but may present acutely with severe symptoms. Hemorrhage into pheochromocytoma is a rare cause of acute presentation that is often devastating to patients. We describe the case of a 34-year-old woman with hemorrhage into a previously undiscovered pheochromocytoma following a fall on a patch of ice. This is the first reported case of hemorrhagic pheochromocytoma associated with traumatic injury. Despite removal of the tumor within 18 hours of presentation, the patient suffered severe complications of massive catecholamine excess, including shock, cardiomyopathy, and adult respiratory distress syndrome. Animal studies have shown that early treatment with alpha blockers can prevent some, if not all of these complications. Proper management of hemorrhagic pheochromocytoma should include a high index of suspicion with early diagnosis and treatment with alpha blockers and surgical resection of the tumor when the patient is stable enough to tolerate the procedure.

Wound-induced calcium waves in alveolar type II cells.

Alveolar type II epithelial (ATII) cells repopulate the alveolus after acute lung injury. We hypothesized that injury would initiate signals in nearby survivors. When rat ATII monolayers were wounded, elevations in intracellular free Ca2+ concentration ([Ca2+]i) began at the edge of the wound and propagated outward as a wave for at least 300 microns. The [Ca2+]i wave was due to both influx of extracellular Ca2+ and release of intracellular Ca2+ stores. Reducing Ca2+ influx with brief treatments of ethylene glycol-bis(beta-aminoethyl ether)-N,N,N',N'-tetraacetic acid or Gd3+ reduced both the amplitude and the apparent speed. Draining intracellular Ca2+ stores by pretreatment with cyclopiazonic acid eliminated the [Ca2+]i wave. Therefore, the [Ca2+]i wave depended critically on intracellular Ca2+ stores. [Ca2+]i elevations propagated over a break in the monolayer, suggesting that extracellular pathways were involved. Furthermore, extracellular factors from injured cells elevated [Ca2+]i in uninjured cultures. We conclude that wounding produces a [Ca2+]i wave in surviving cells and part of this response is mediated by soluble factors released into the extracellular space during injury.