Diltiazem restores IL-2, IL-3, IL-6, and IFN-gamma synthesis and decreases host susceptibility to sepsis following hemorrhage

Various beneficial effects of calcium channel blockers on cell and organ function following endotoxic shock, organ ischemia, and reperfusion have been reported; however, it is not known whether these agents have any salutary or deleterious effects on immune responses after low-flow conditions. Therefore, the aim of this study was to determine (a) the effect of hemorrhage on lymphocyte IL-2, IL-3, IL-6, and IFN-gamma synthesis, and (b) whether diltiazem has any salutary or adverse effects on these parameters when administered following hemorrhage and resuscitation. To study this, C3H/HeN mice were bled to a mean blood pressure of 35 mm Hg, maintained at that level for 60 min, and resuscitated with shed blood plus twice that volume of Ringer's lactate. Immediately following resuscitation mice received either diltiazem (2400, 800, or 400 micrograms/kg body wt), or an equivalent volume of saline. The mice were sacrificed 24 hr later, splenic lymphocytes were obtained, and their capacity to produce lymphokines was assessed. The results indicated that in the vehicle-treated animals, hemorrhage significantly decreased (P less than 0.05) IL-2, IL-3, IL-6, and IFN-gamma synthesis by 82 +/- 19%, 64 +/- 28%, 71 +/- 11%, and 86 +/- 14%, respectively. However, diltiazem (400 but not 2400 micrograms/kg) treatment after hemorrhage restored lymphocyte capacity to produce IL-2, IL-3, IL-6, and IFN-gamma (P less than 0.05). Additional groups of animals were subjected to sepsis by cecal ligation and puncture 3 days following hemorrhage.(ABSTRACT TRUNCATED AT 250 WORDS)     

Chloroquine attenuates hemorrhagic shock-induced immunosuppression and decreases susceptibility to sepsis.

Hemorrhagic shock causes a severe suppression of cellular immunity and an increased susceptibility to sepsis that may be due to increased release of prostaglandin E2 by macrophages. Since chloroquine inhibits the secretion of prostaglandin E2 by macrophages in vitro, the effects of chloroquine administration in vivo following hemorrhagic shock on macrophage prostaglandin E2 secretion and on depressed cellular immunity were examined. Inbred C3H/HeN male mice, aged 6 to 8 weeks, were bled to a mean blood pressure of 35 mm Hg, which was maintained for 60 minutes, and adequately, resuscitated. Mice then received intramuscular injections of either saline (vehicle) or chloroquine (10 mg/kg of body weight). Prostaglandin E2 in macrophage supernatants (radioimmunoassay) concanavalin A-dependent splenocyte proliferation, and interleukin 2 in splenocyte supernatants (CTLL 20 interleukin 2-dependent proliferation) were determined 2 or 24 hours later. Hemorrhage caused a significant decrease of splenocyte proliferation (47%) and interleukin 2 release (49%) at 24 hours, while prostaglandin E2 secretion from macrophages was elevated at 2 hours. Chloroquine treatment attenuated depression of splenocyte functions and reduced prostaglandin E2 release. Furthermore, chloroquine treatment decreased the mortality of septic mice after hemorrhage to levels comparable with those of sham-operated mice. Thus, chloroquine may be a useful adjunct in the clinical setting for the treatment of shock-induced immunodepression and increased susceptibility to sepsis following hemorrhage.     

Interferon-gamma attenuates hemorrhage-induced suppression of macrophage and splenocyte functions and decreases susceptibility to sepsis.

Although it is known that interferon-gamma synthesis and macrophage functions are depressed after hemorrhage, it remains to be determined whether systemic administration of interferon-gamma has any effect on hemorrhage-induced depression of macrophage and splenocyte functions. To study this, C3H/HEN mice were bled to a mean blood pressure of 35 mm Hg, maintained for 60 minutes, and followed by adequate fluid resuscitation. The mice then received either 1000 units interferon-gamma or saline solution (vehicle). Peritoneal (pM phi) and splenic (sM phi) macrophages and splenocytes were isolated 24 hours later. PM phi antigen presentation was measured by coculturing pM phi with the D10.G4.1 cell clone. Major histocompatibility complex class II (Ia) antigen expression was determined by direct immunofluorescence. Cytokine release by pM phi, sM phi, and splenocytes was assessed with specific bioassays. For survival studies, mice were subjected to sepsis 3 days after hemorrhage. Treatment with interferon-gamma restored (p less than or equal to 0.05) hemorrhage-induced suppression of pM phi antigen presentation capacity and Ia antigen expression and increased (p less than or equal to 0.05) interleukin-1 and tumor necrosis factor release by pM phi and sM phi, as well as splenocyte proliferation (p less than or equal to 0.05). Interferon-gamma also decreased (p less than or equal to 0.007) the susceptibility to sepsis after hemorrhage. Thus interferon-gamma represents a potent agent for treating hemorrhagic shock-induced immunosuppression and for increasing the ability of the host defense system to combat bacterial infections after hemorrhage.     

Enhanced susceptibility to sepsis after simple hemorrhage. Depression of Fc and C3b receptor-mediated phagocytosis

To determine whether phagocytosis mediated by Fc receptors and/or receptors for the third component of complement (C3b) are altered after hemorrhage, C3H/HeN mice were subjected to nonlethal hemorrhage and then adequately resuscitated. Twelve hours after the hemorrhagic episode, a significant decrease in both Fc (-55.2%) and C3b (-46.6%) receptor-positive peritoneal macrophages was observed compared with controls. At 24 hours the extent of the depression, while still marked, was only -22.5% and -17.4% for Fc and C3b receptors, respectively. By day 3 after hemorrhage, no differences could be observed for either of these receptors. The capacity of macrophages from mice after hemorrhage to elaborate interleukin 1 or tumor necrosis factor-alpha showed no increase over that of the sham controls, and serum levels of endotoxin were not elevated 2 or 24 hours after hemorrhage. Moreover, endotoxin-tolerant C3H/HeJ mice also exhibited depression of both receptors after hemorrhage. Thus, the inability of the host macrophages to clear opsonized infectious agents after hemorrhage may be due in part to the loss of Fc and C3b receptors on macrophages.     

Catastrophic sepsis and hemorrhage following transrectal ultrasound guided prostate biopsies

We report 2 cases of catastrophic complications following routine transrectal ultrasound guided prostate biopsy. The first patient incurred near-fatal septic shock due to multi-resistant Escherichia coli. Due to the severity of his shock, he developed bilateral leg gangrene requiring amputations. The second patient incurred significant hemorrhage eventually requiring an emergent general anesthesia and surgical management to control hemorrhage after other measures failed. While rare events, these reports emphasize the caution needed for physicians who routinely order prostate biopsies.     

Crystalloid resuscitation restores but does not maintain cardiac output following severe hemorrhage

Although Ringer's lactate (RL) is routinely used for resuscitation, it is not known whether this fluid alone restores and maintains the depressed cardiac output (CO) following severe hemorrhage. To study this, a fiberoptic catheter was inserted to the level of the aortic arch in rats. Following indocyanine green (0.05 mg) administration, CO was measured using an in vivo hemoreflectometer (IVH). The rats were then bled to and maintained at a mean arterial pressure (MAP) of 40 mmHg until 40% of the shed blood volume was returned in the form of RL. They were resuscitated with 2, 3, or 4 times (X) the volume of the shed blood with RL and CO recorded at various intervals thereafter. The results indicate that CO decreased significantly during hemorrhage and remained depressed following resuscitation with 2 or 3X RL. CO was normal immediately after resuscitation with 4X RL, but it was not sustained and decreased significantly 0.5 to 8 hr postresuscitation. This was not due to the decreased hematocrit since acute hemodilution did not decrease CO. These results indicate that: (1) the progressive changes in CO following hemorrhage and resuscitation can be measured in rats by using IVH; (2) resuscitation with 4X RL restores total peripheral resistance to normal, but does not maintain CO, suggesting that pharmacological support may be needed under such conditions; (3) the lack of maintenance of CO following resuscitation may play an important role in the development of multiple organ failure after severe hemorrhage.     

Depression of cellular immunity after multiple trauma in the absence of sepsis

We have previously reported that severe burn injury was regularly accompanied by impaired lymphocyte responses to T cell mitogens, circulating suppressor lymphocytes, and serum factors suppressive of lymphocyte activation. However, in burned patients it was difficult to determine whether these manifestations of suppressed immunity were predictive of, or the result of, sepsis which was ubiquitous in this population. In an attempt to clarify this issue, we have studied 31 patients with multiple trauma (without burns) mean age, 31 years; average injury severity score, 22; range, 9-56; in whom sepsis was less common. Patients were tested for lymphocyte response to the T cell mitogens PHA and Con A, the percentage of circulating putative suppressor (OKT8) and helper (OKT4) T cells using monoclonal antibodies, circulating suppressor cell activity as revealed by functional assays, and serum suppression of lymphocyte activation. Patients were compared with ten normal volunteers (mean age, 32) studied simultaneously. Significant suppression (greater than 50% compared with controls) in lymphocyte responses to mitogens 1 to 5 days after injury was seen in 12 patients, was accompanied by a shift in the ratio of helper (OKT4) to suppressor (OKT8) T cells (patients, 0.96:1; normals, 1.82:1; p less than 0.01), and was followed by the appearance of significant (greater than 50%) serum suppressive activity in six of the 12 patients. Circulating suppressor cell activity as revealed by functional assays was also seen early after injury in three of 12 patients.(ABSTRACT TRUNCATED AT 250 WORDS)     

Left ventricular mechanical unloading restores Beta-2-adrenergic receptor mRNA expression and decreases susceptibility to ischemia and reperfusion in the failing heart

OBJECTIVES: Left ventricular (LV) mechanical unloading is known to reduce the hemodynamic demands of failing LV, resulting in improved myocyte contractility. This study was designed to examine effects of LV unloading on beta-adrenergic receptor (BAR) expression and ischemic susceptibility to ischemia reperfusion. METHODS: Five groups were studied: group 1 [unloading myocardial infarction (MI), n = 6], MI hearts 2 weeks after coronary ligation subjected to LV unloading by heterotopic heart transplantation for 2 weeks; group 2 (2-week MI, n = 6), MI hearts left for 2 weeks without unloading; group 3 (4-week MI, n = 6), MI hearts left for 4 weeks without unloading; group 4 (control, n = 6), normal (non-MI) hearts as a control with no interventions, and group 5 (unloading control, n = 5), normal (non-MI) hearts subjected to LV unloading for 2 weeks. Then, all hearts were isolated and subjected to 20 min of global ischemia and 60 min of reperfusion on Langendorff apparatus. LV pressures and coronary flow were measured throughout the experiment. Either total BAR density or beta(2)-adrenergic receptor (B2AR) mRNA expression in the noninfarcted myocardium was determined by radioligand binding assays or real-time quantitative RT-PCR, respectively. RESULTS: LV unloading improved postischemic functional recovery (unloading MI vs. 2-week MI vs. 4-week MI: 74 +/- 6 vs. 54 +/- 5 vs. 51 +/- 4%; p < 0.05 vs. unloading MI). LV unloading restored B2AR mRNA expression (unloading MI vs. 2-week MI vs. 4-week MI: 4.78 +/- 0.21 vs. 2.80 +/- 0.19 vs. 2.24 +/- 0.17 x 10(7) copy/microg total RNA; p < 0.05 vs. unloading MI). CONCLUSION: LV mechanical unloading restored B2AR mRNA expression and improved postischemic functional recovery.     

ATP-MgCl2 restores the depressed hepatocellular function and hepatic blood flow following hemorrhage and resuscitation

Although ATP-MgCl2 produces a myriad of beneficial effects following organ ischemia and simple hemorrhagic shock in animal models which involved heparinization and/or blood resuscitation, it is not known whether ATP-MgCl2 has any salutary effect on the depressed active hepatocellular function (AHF) and hepatic microvascular blood flow (HMBF) in a nonheparinized model of trauma and severe hemorrhage in the absence of blood resuscitation. To determine this, rats underwent a midline laparotomy (i.e., trauma induced) and were bled to and maintained at a mean arterial pressure of 40 mm Hg until 40% of the maximum shed blood volume was returned in the form of Ringer's lactate (RL). The animals were then resuscitated with four times the volume of shed blood with RL. ATP-MgCl2, 50 mumoles/kg body weight (BW) each or an equivalent volume of normal saline, was infused intravenously for 95 min during and following crystalloid resuscitation. At 1.5 and 4 hr after resuscitation, AHF (Vmax, maximal velocity of indocyanine green clearance; Km, efficiency of the active transport process) was determined without blood sampling by using an in vivo indocyanine green clearance technique. HMBF was measured with laser Doppler flowmetry. Results indicate that Vmax, Km, and HMBF decreased significantly at 1.5-4 hr after hemorrhage and resuscitation. ATP-MgCl2 infusion restored the depressed Vmax, Km, and HMBF and prevented the occurrence of hepatic edema. The restoration of AHF with ATP-MgCl2 treatment may be due to its direct salutary effect on the active indocyanine green transport process and/or due to improvement in hepatic microcirculation.(ABSTRACT TRUNCATED AT 250 WORDS)     

Dehydroepiandrosterone restores hepatocellular function and prevents liver damage in estrogen-deficient females following trauma and hemorrhage

INTRODUCTION: Recent studies have shown that administration of the sex steroid dehydroepiandrosterone (DHEA) in males following trauma-hemorrhagic shock has salutary effects on the depressed cardiovascular and immunological functions under those conditions. Since the effects of sex steroids are gender specific, we examined whether administration of DHEA has any beneficial effects on hepatocellular function in female rats with low estrogen levels following trauma-hemorrhage. METHODS: Ovariectomy was performed in female Sprague-Dawley rats 14 days prior to the experiments. The animals then underwent a 5-cm midline laparotomy and were subjected to hemorrhagic shock (40 mm Hg for 90 min). This was followed by fluid resuscitation (Ringer's lactate over 60 min) and administration of DHEA (30 mg/kg BW) or vehicle subcutaneously at the end of resuscitation. At 24 h after resuscitation hepatocellular function, i.e., clearance of indocyanine green (ICG), and hepatocyte damage (serum alanine aminotransferase) were measured. Plasma levels of DHEA and 17beta-estradiol were also assayed. RESULTS: Vehicle-treated rats had significantly reduced hepatocellular function, increased ALT activity, and decreased levels of 17beta-estradiol following trauma-hemorrhage compared to sham-operated animals (P < 0.05, ANOVA and Student-Newman-Keuls test). In animals receiving DHEA following trauma-hemorrhage, hepatocellular function and ALT activity were similar to those of shams. However, administration of DHEA did not influence the plasma levels of 17beta-estradiol. CONCLUSIONS: Administration of DHEA following trauma-hemorrhage restored hepatocellular function and reduced hepatic damage that was observed in ovariectomized female rats under such conditions. This salutary effect of DHEA did not appear to be due to elevated levels of plasma 17beta-estradiol. We therefore propose that DHEA should be considered a novel, safe, and useful adjunct in the treatment of trauma-induced hepatocellular dysfunction in ovariectomized and postmenopausal females.     

Substrate composition and sepsis. Effects on immunity

A randomized prospective study was performed to determine the effects of substrate composition on immunity in septic malnourished patients. A balanced substrate formula was administered to 11 patients with sepsis and 11 nonseptic patients. This provided 40 kcal/kg/day and 1 to 1.5 g of protein per kilogram each day with a carbohydrate-nitrogen ratio of 50:1. A 25% dextrose and 4.25% protein solution that provided 50 kcal/kg/day and 1 to 1.5 g of protein per kilogram each day with a carbohydrate-nitrogen ratio of 150:1 was provided to ten patients with sepsis and 11 without. Skin test conversion rates were not affected by substrate composition; however, the absolute lymphocyte count was significantly improved in septic patients who achieved positive nitrogen balance, regardless of the nutritional support regimen used. These findings suggest that substrate composition per se has no effect on immunologic responsiveness.     

Sex-dependent local cellular immunity to alloantigens

A local component of cellular immunity was detected in mice that had been immunized against histocompatibility antigens. The status of this local immunity was determined using a node-onto-kidney (NOK) assay in which lymph nodes draining the site of immunization as well as distant (nondraining) lymph nodes of the immunized mice were grafted onto the kidneys of mice of the immunizing strain. In this assay, the weight gained by each node piece was taken as a measure of its immunological responsiveness. The responsiveness of a draining lymph node was directly compared with that of a distant node after both had been grafted onto the same host kidney. We consistently found that the draining lymph nodes of immunized male mice were more responsive than their distant nodes, whereas the draining lymph nodes of immunized female mice were less responsive than their distant nodes. Male mice were converted to the female pattern of hyporesponsiveness in the draining nodes by performing bilateral orchidectomy, suggesting that the male pattern depends upon the presence of testicular hormones. Additional studies showed there was a significant reduction in the reactivity of uterine draining lymph nodes during both syngeneic and allogeneic pregnancy, raising the possibility that the female pattern of hyporesponsiveness facilitates fetal survival by reducing the maternal immune response to fetal antigens and alloantigens during pregnancy.     

Inhibition of prostaglandin synthesis restores normal hemodynamics in canine hyperdynamic sepsis.

This study investigates the role of prostaglandins (PG) in hyperdynamic sepsis. Thirteen chronically instrumented dogs were rendered septic by implanting in the peritoneal cavity a fibrin clot containing viable Escherichia coli. One day later, cardiac output (CO) increased from 2.80 +/- 0.22 to 3.72 +/- 0.32 l/min (p = 0.011); heart rate (HR) increased from 122 +/- 8 to 147 +/- 6 beats/min (p = 0.005); mean pulmonary artery pressure (PAP) increased from 15 +/- 1 to 19 +/- 1 mmHg (p = 0.003); mean systemic arterial pressure (MAP) decreased from 120 +/- 5 to 107 +/- 7 mmHg; and systemic vascular resistance (SVR) decreased from 44.1 +/- 2.6 to 29.3 +/- 1.9 mmHg/l/min (p less than 0.001). Sixty minutes after intravenous injection of indomethacin (2 mg/kg) or ibuprofen (25 mg/kg), CO decreased to 2.60 +/- 0.21 l/min (p less than 0.001); HR decreased to 118 +/- 5 beats/min (p less than 0.001); PAP decreased to 17 +/- 1 mmHg (p = 0.021); and SVR increased to 43.7 mmHg/l/min (p less than 0.001). In seven control dogs, laparotomy alone did not significantly affect any of these parameters. Infusion of indomethacin caused a slight increase in MAP (106 +/- 4 to 116 +/- 4 mmHg, p = 0.035) but otherwise did not alter hemodynamics. It is concluded that administration of indomethacin or ibuprofen restores normal hemodynamics in a canine model of high-output sepsis, probably by inhibiting PG synthesis.     

Upper gastrointestinal hemorrhage: aggressive management decreases mortality.

In a retrospective study of 630 patients with upper gastrointestinal hemorrhage admitted to the Royal Victoria Hospital between 1963 and 1971, the overall mortality was 12.54%. Mortality increased in patients receiving more than 10 units of blood and in patients over 60 years of age. Mortality decreased in patients in whom the site of hemorrhage was known prior to operation. Early surgery for gastric ulcers and conservative therapy for acute gastric erosions reduced mortality. Therefore in 334 patients admitted to the Royal Victoria Hospital between 1973 and 1976 with upper gastrointestinal hemorrhage, an aggressive approach to diagnosis and management was emphasized. There was a significant decrease in patients with duodenal ulcers, acute gastric erosions, and gastric ulcers who received more than 10 units of blood. There was a significant increase in the use of endoscopy to establish the source of hemorrhage and a significant increase in the use of endoscopy to establish the source of hemorrhage and a significant decrease in the number of patients who did not have a diagnosis prior to operation. There was also a significant increase in early surgery for gastric ulcers. This regimen led to a significant decrease in mortality (6.69% vs. 12.54%). This report demonstrates that early diagnosis and management based on the lesion found reduces mortality from upper gastrointestinal hemorrhage.     

Long peritoneal lavage decreases pancreatic sepsis in acute pancreatitis.

Late infection of devitalized pancreatic and peripancreatic tissue has become the major cause of morbidity in severe acute pancreatitis. Previous experience found that peritoneal lavage for periods of 48 to 96 hours may reduce early systemic complications but did not decrease late pancreatic sepsis. A fortunate observation led to the present study of the influence of a longer period of lavage on late sepsis. Twenty-nine patients receiving primary nonoperative treatment for severe acute pancreatitis (three or more positive prognostic signs) were randomly assigned to short peritoneal lavage (SPL) for 2 days (15 patients) or to long peritoneal lavage (LPL) for 7 days (14 patients). Positive prognostic signs averaged 5 in both groups but the frequency of five or more signs was higher in LPL (71%) than in SPL (47%). Eleven patients in each group had early computed tomographic (CT) scans. Peripancreatic fluid collections were shown more commonly in LPL (82%) than in SPL (54%) patients. Longer lavage dramatically reduced the frequency of both pancreatic sepsis (22% LPL versus 40% SPL) and death from sepsis (0% LPL versus 20% SPL). Among patients with fluid collections on early CT scan, LPL led to a more marked reduction in both pancreatic sepsis (33% LPL versus 83% SPL) and death from sepsis (0% LPL versus 33% SPL). The differences were even more striking among 17 patients with five or more positive prognostic signs. In this group the incidence of pancreatic sepsis was 30% LPL versus 57% SPL and of death from sepsis 0% (LPL) versus 43% (SPL) (p = 0.05). In these patients, overall mortality was also reduced (20% LPL versus 43% SPL). When 20 patients treated by LPL were compared with 91 other patients with three or more positive prognostic signs who were treated without lavage or by lavage for periods of 2 to 4 days, the frequency of death from pancreatic sepsis was reduced from 13% to 5%. In those with five or more signs, the incidence of sepsis was reduced from 40% to 27% (p = 0.03) and of death for sepsis from 30% to 7% (p = 0.08). These findings indicate that lavage of the peritoneal cavity for 7 days may significantly reduce both the frequency and mortality rate of pancreatic sepsis in severe acute pancreatitis.     

Diminished cellular immunity due to impaired nutrition in oesophageal carcinoma.

The nutritional status of 15 Negro patients suffering from unresectable carcinoma of the midthoracic oesophagus was evaluated before and after palliative pulsion intubation. All were shown to be in negative nitrogen balance and to have a compromised non-specific cellular immune response. Correction of protein-calorie malnutrition and the achievement of positive nitrogen balance were associated with an increase in absolute lymphocyte and T lymphocyte numbers and a significant increase in lymphocyte response to PHA. The improvement in immunological reactivity occurred without any attempt at therapeutic reduction in tumour bulk.