The effect of amifostine on bacterial translocation after radiation induced acute enteritis.

PURPOSE: To investigate the effects of amifostine on bacterial translocation and overgrowth in colonic flora after acute radiation enteritis in a rat model. METHODS: Thirty-two female Wistar albino rats were divided into four groups: Group-1 (n=8): only normal saline was administered intraperitoneally. Group-2 (n=8): first serum saline was administered intraperitoneally and 30 minutes later 20 Gy radiation was applied to abdominopelvic region. Group-3 (n=8): only amifostine 200 ml/kg was administered intraperitoneally and radiation was not applied. Group-4 (n=8): first amifostine 200 ml/kg was administered intraperitoneally and 30 minutes later 20 Gy radiation was applied to abdominopelvic region. On the 5th day after radiation, samples of mesenteric lymph tissues and cecal contents were taken by laparotomy for microbiological culture. RESULTS: Intraperitoneal amifostine administration significantly decreased the bacterial overgrowth related to radiation in colon but did not significantly decrease the bacterial translocation. CONCLUSION: Although not providing a full protection on the damaged mucosal barrier, amifostine significantly decreased the bacterial overgrowth in the cecal content after high dose radiation. There is a need to find out appropriate amifostine dose under different radiation applications avoiding bacterial translocation in gastrointestinal system.

The effect of amifostine on bacterial translocation after radiation induced acute enteritis

ABSTRACT PURPOSE: To investigate the effects of amifostine on bacterial translocation and overgrowth in colonic flora after acute radiation enteritis in a rat model. METHODS: Thirty-two female Wistar albino rats were divided into four groups: Group-1 (n=8): only normal saline was administered intraperitoneally. Group-2 (n=8): first serum saline was administered intraperitoneally and 30 minutes later 20 Gy radiation was applied to abdominopelvic region. Group-3 (n=8): only amifostine 200 ml/kg was administered intraperitoneally and radiation was not applied. Group-4 (n=8): first amifostine 200 ml/kg was administered intraperitoneally and 30 minutes later 20 Gy radiation was applied to abdominopelvic region. On the 5th day after radiation, samples of mesenteric lymph tissues and cecal contents were taken by laparotomy for microbiological culture. RESULTS: Intraperitoneal amifostine administration significantly decreased the bacterial overgrowth related to radiation in colon but did not significantly decrease the bacterial translocation. CONCLUSİON: Although not providing a full protection on the damaged mucosal barrier, amifostine significantly decreased the bacterial overgrowth in the cecal content after high dose radiation. There is a need to find out appropriate amifostine dose under different radiation applications avoiding bacterial translocation in gastrointestinal system.

Severe Acute Pancreatitis: Gut Barrier Failure, Systemic Inflammatory Response, Acute Lung Injury, and the Role of the Mesenteric Lymph.

BACKGROUND: Severe acute pancreatitis (AP) often leads to distant organ dysfunction with a high morbidity and mortality rate. The most common and earliest organ to fail is the lungs, but the exact pathophysiological mechanisms underlying the disease are still unclear. No successful targeted therapy exists, and treatment is limited to organ supportive care. It is believed that the gut is involved in the development of distant organ failure, as severe AP is associated with changes in the microcirculation, gut permeability/motility, bacterial translocation, and activation of the gut-associated lymphoid tissue (GALT). Experimental evidence implicates the mesenteric lymph as a primary route for these toxic factors to gain access to the systemic circulation. This literature overview was made to survey these mechanisms and the potential of surgical interventions on the thoracic duct as a means of therapy. METHODS: Review of the pertinent English-language literature. RESULTS: In experimental studies, interruption of mesenteric lymphatic flow has preventive qualities for acute lung injury (ALI) in the setting of critical illness with various etiologies. Experimentally, diversion of mesenteric lymph is able to prevent ALI if done before its development, whereas a later intervention partially reduces the lung damage. Few studies have investigated surgical approaches to the thoracic duct in human beings under these circumstances, and the ones that have been performed are of low quality and have conflicting results. It seems likely that the intervention would need to be performed prior to the development of ALI to obtain maximum benefits, which complicates its application clinically, because prediction of ALI cannot today be done with high precision. CONCLUSION: Studies are ongoing to identify the factors carried in mesenteric lymph that may cause end-organ failure (e.g., ALI) and, once recognized, might allow the development of novel targeted agents that would modify the disease course.

A "CLEAN CASE" OF SYSTEMIC INJURY: MESENTERIC LYMPH AFTER HEMORRHAGIC SHOCK ELICITS A STERILE INFLAMMATORY RESPONSE.

Postinjury multiple organ failure results from an inappropriate overwhelming immune response to injury. During trauma and hemorrhagic shock (T/HS), mesenteric ischemia causes gut mucosal breakdown with disruption of the intestinal barrier. It has been proposed that this releases the gut microbiota systemically via postshock mesenteric lymph (PSML), engendering infectious complications. Despite extensive investigation, no clear evidence has been presented for gut bacterial translocation after resuscitation from T/HS. However, such previous studies were limited by available technologies. More sensitive methods, such as quantitative polymerase chain reaction, have since emerged for detection of bacterial presence and danger-associated molecular patterns (DAMPs). Quantitative polymerase chain reaction was applied to PSML derived from a rat model of T/HS. No bacterial presence was detected in a series of 12 samples, whereas multiple lymph samples showed the presence of DAMPs after T/HS. Thus, we confirmed that bacterial translocation does not exist in PSML after resuscitation from T/HS-associated mesenteric ischemia. However, T/HS does increase the presence of mitochondrial DAMPs in PSML. These results support our current position that PSML elaborates remote organ injury by multiple inflammatory mechanisms, including lipid-mediated proinflammatory stimuli, and by contribution from gut-derived DAMPs.

Lymphatic fluid for the detection of Mycobacterium avium subsp. paratuberculosis in cows by PCR, compared to fecal sampling and detection of antibodies in blood and milk.

Johne's disease (JD), caused by Mycobacterium avium subsp. paratuberculosis (MAP), can cause considerable economic losses in affected herds. Early diagnosis of JD is hampered by the chronic nature of the disease with a slow subclincal progression. The aim of the present study was to challenge the hypothesis that lymphatic fluid is of diagnostic value in the early stages of the disease. Lymphatic fluid from 122 animals was collected and tested for MAP by nested PCR for IS900 and compared to the results of testing for MAP in feces (culture), blood and milk (ELISA) in 110 of these samples. MAP was detected by PCR in 27.1% of the lymph samples. Agreement between the tests was poor: 6.9% of the lymph positive cows were also positive in all other tests applied, and 69.0% had negative results in fecal culture, blood and milk ELISA. Resampling of 25 cows after 8 to 12 and 16 to 20 months revealed 20.0% lymph positive animals at the first, 5.5% at the second and 27.8% at the third sampling, respectively. Only one cow showed positive lymph-PCR results at more than one sampling date. Lymph-positive cows had a 7.2 times greater likelihood of being culled within 8 to 12 months after sampling, compared to negative cows, mainly due to other health issues than JD. It can be concluded, that lymphatic fluid might be promising for the detection of early MAP-infection in cows, but further studies to elucidate the potential of this diagnostic approach are needed.

Intravenous infusion of mesenteric lymph from severe intraperitoneal infection rats causes lung injury in healthy rats.

AIM: To investigate whether mesenteric lymph from rats with severe intraperitoneal infection (SII) induces lung injury in healthy rats. METHODS: Twenty adult male specific pathogen-free Wistar rats were divided into two groups. Animals in the SII group received intraperitoneal injection of Escherichia coli (E. coli) at a dose of 0.3 mL/100 g. Control rats underwent the same procedure, but were injected with normal saline rather than E. coli. We ligated and drained the mesenteric lymphatic vessels and collected the mesenteric lymph. Mesenteric lymph collected from SII or control rats was infused intravenously into male healthy rats at a rate of 1 mL/h for 4 h. At the end of the infusion, all rats were sacrificed. Lungs were removed and examined histologically, and wet-to-dry weight (W/D) ratio and myeloperoxidase (MPO) activity were determined. Enzyme-linked immunosorbent assay (ELISA) was performed to determine the levels of the proinflammatory cytokines tumor necrosis factor (TNF)-α and interleukin (IL)-6. We performed Western blot to investigate the activation of Toll-like receptor (TLR)-4, and nuclear factor (NF)-κB p65. RESULTS: Compared with the control infusion group, there were obvious pathological changes in the SII group. The W/D ratio was significantly increased in the SII compared to control infusion group (5.86 ± 0.06 vs 5.37 ± 0.06, P < 0.01). MPO activity significantly increased in the SII infusion rats with a mean level of 0.86 ± 0.02 U/g compared to 0.18 ± 0.05 U/g in the control group (P < 0.01). The concentrations of TNF-α and IL-6 were significantly increased in the SII infusion group. The concentration of TNF-α was significantly increased in the SII infusion rats compared to control infusion rats (2104.46 ± 245.91 vs 1475.13 ± 137.82 pg/mL, P < 0.01). The concentration of IL-6 was significantly increased in the SII infusion rats with a mean level of 50.56 ± 2.85 pg/mL compared to 43.29 ± 2.02 pg/mL (P < 0.01). The expression levels of TLR-4 (7496.68 ± 376.43 vs 4589.02 ± 233.16, P < 0.01) and NF-κB (8722.19 ± 323.96 vs 6498.91 ± 338.76, P < 0.01) were significantly increased in the SII infusion group compared to the control infusion group. The infusion of SII lymph, but not control lymph, caused lung injury. CONCLUSION: The results indicate that SII lymph is sufficient to induce acute lung injury.

A spatially-organized multicellular innate immune response in lymph nodes limits systemic pathogen spread.

The lymphatic network that transports interstitial fluid and antigens to lymph nodes constitutes a conduit system that can be hijacked by invading pathogens to achieve systemic spread unless dissemination is blocked in the lymph node itself. Here, we show that a network of diverse lymphoid cells (natural killer cells, γδ T cells, natural killer T cells, and innate-like CD8+ T cells) are spatially prepositioned close to lymphatic sinus-lining sentinel macrophages where they can rapidly and efficiently receive inflammasome-generated IL-18 and additional cytokine signals from the pathogen-sensing phagocytes. This leads to rapid IFNγ secretion by the strategically positioned innate lymphocytes, fostering antimicrobial resistance in the macrophage population. Interference with this innate immune response loop allows systemic spread of lymph-borne bacteria. These findings extend our understanding of the functional significance of cellular positioning and local intercellular communication within lymph nodes while emphasizing the role of these organs as highly active locations of innate host defense.

Vaccination-induced syphilis and the Hübner malpractice litigation.

This article examines smallpox vaccination in the 19th century as background for a notorious medical malpractice case that occupied Bavarian courts from April 1853 until May 1854. Dr. Georg Hübner, the defendant, was accused of having initiated a small epidemic of syphilis by using the lymph of a syphilitic infant to vaccinate 13 infants. The litigation and its published contemporaneous discussion demonstrate conflicts in the understanding of syphilis, the hazards of having to make a purely clinical diagnosis, the effect of obsolete legal wording in medical litigation, and the attitude of leading physicians to a guilty colleague. This case ultimately led to efforts to make arm-to-arm smallpox vaccination safer, and by 1898 to abandon the technique in favor of bovine sources that were sterilized and stabilized by various methods.

The collection of lymphatic fluid from the bovine udder and its use for the detection of Mycobacterium avium subsp. paratuberculosis in the cow.

The objective of the current study was to evaluate the feasibility of lymph collection from the bovine udder and to investigate if the lymphatic fluid might be of diagnostic value in cows infected with Mycobacterium avium subsp. paratuberculosis (MAP), the etiologic agent of paratuberculosis. Lymph fluid collection was attempted from 58 cows, and the reactions of the cows as well as the level of difficulty of the procedure were recorded in 56 animals. Lymph samples (51 in total) were tested for the presence of MAP by nested polymerase chain reaction. Collection of the lymphatic fluid caused no or mild signs of discomfort in 94.6% of the cows; in 51.8% of cows, lymphatic fluid was attained on the first attempt, while sample collection was unsuccessful in 12.1%. Mycobacterium avium subsp. paratuberculosis was detected in 43.1% of all lymph samples. The bacterium was present in 66.7% of cows with clinical Johne's disease, in 42.8% of asymptomatic cows with a positive or suspicious enzyme-linked immunosorbent assay (ELISA) result in blood, and in 38.7% of cows with a negative ELISA result in blood. The present study shows that the procedure was well tolerated by most cows and can easily be performed on farm. The current report of the isolation of MAP from lymph fluid suggests that the present approach could be used for the early detection of Johne's disease in cattle.

Potential role of the intestinal microbiota of the mother in neonatal immune education.

Mucosal dendritic cells are at the heart of decision-making processes that dictate immune reactivity to intestinal microbes. They ensure tolerance to commensal bacteria and a vigorous immune response to pathogens. It has recently been demonstrated that the former involves a limited migration of bacterially loaded dendritic cells from the Peyer's patches to the mesenteric lymph nodes. During lactation, cells from gut-associated lymphoid tissue travel to the breast via the lymphatics and peripheral blood. Here, we show that human peripheral blood mononuclear cells and breast milk cells contain bacteria and their genetic material during lactation. Furthermore, we show an increased bacterial translocation from the mouse gut during pregnancy and lactation and the presence of bacterially loaded dendritic cells in lactating breast tissue. Our observations show bacterial translocation as a unique physiological event, which is increased during pregnancy and lactation. They suggest endogenous transport of intestinally derived bacterial components within dendritic cells destined for the lactating mammary gland. They also suggest neonatal immune imprinting by milk cells containing commensal-associated molecular patterns.

Influences of intestinal ligation on bacterial translocation and inflammatory response in rats with hemorrhagic shock: implications for damage control surgery.

Damage Control Surgery (DCS) treatment of rapid intestinal ligation to control the bowel spillage in severe abdominal trauma induces acute intestinal loop obstruction. The purpose of this study was to investigate the effects of intestinal ligation on bacterial translocation (BT) and inflammatory reaction under the condition of acute hemorrhagic shock and its probable pathophysiology. Escherichia coli TG1 labeled with green fluorescent protein was used to track BT by gavage to rats. Group Shock rats were subjected to hemorrhagic shock for 30 minutes. Group Shock+Ligation (Shock+L) rats were subjected to hemorrhagic shock and following intestinal ligation. We found that hemorrhagic shock alone or in combination with intestinal ligation caused not only morphological damage to ileal mucosa, but also induced BT and promoted release of TNF-alpha, IL-6, and IL-10 in serum and lymph. Ileal mucosa injuries and BT were significantly aggravated and cytokine levels in serum and lymph were significantly elevated in group Shock+L compared with group Shock. The positive proportions of bacterial culture and cytokine levels were significantly elevated in lymph compared with these in blood in both groups. By fluorescence microscope and XbaI restriction digestion analysis, we elucidated that the bacteria isolated from extraintestinal organs were the same bacteria we gavaged to the rats. We first confirmed that DCS treatment of rapid intestinal ligation under the condition of acute hemorrhagic shock leads to aggravated intestinal mucosa barrier injury and BT and elevated inflammatory response. The intestinal BT and immunoinflammatory factors may act through or mainly through lymph route.

Systemic translocation of Salmonella enterica serovar Dublin in cattle occurs predominantly via efferent lymphatics in a cell-free niche and requires type III secretion system 1 (T3SS-1) but not T3SS-2.

Salmonella enterica is an important diarrheal pathogen, and infections may involve severe systemic sequelae depending on serovar- and host-specific factors. The molecular mechanisms underlying translocation of host-restricted and -specific serovars of S. enterica from the intestines to distal organs are ill defined. By surgical cannulation of lymph and blood vessels draining the distal ileum in cattle, S. enterica serovar Dublin was observed to translocate predominantly via mesenteric lymph nodes to efferent lymphatics in a manner that correlates with systemic virulence, since the fowl typhoid-associated serovar Gallinarum translocated at a significantly lower level. While both S. enterica serovars Dublin and Gallinarum were intracellular while in the intestinal mucosa and associated with major histocompatibility complex class II-positive cells, the bacteria were predominantly extracellular within efferent lymph. Screening of a library of signature-tagged serovar Dublin mutants following oral inoculation of calves defined the role of 36 virulence-associated loci in enteric and systemic phases of infection. The number and proportion of tagged clones reaching the liver and spleen early after oral infection were identical to the values in efferent lymph, implying that this may be a relevant mode of dissemination. Coinfection studies confirmed that lymphatic translocation requires the function of type III secretion system 1 (T3SS-1) but, remarkably, not T3SS-2. This is the first description of the mode and genetics of systemic translocation of serovar Dublin in its natural host.

The effectiveness of long-acting penicillin (penidur) in preventing recurrences of dermatolymphangioadenitis(DLA) and controlling skin, deep tissues, and lymph bacterial flora in patients with "filarial" lymphedema.

Dermatolymphangioadenitis (DLA) is a common and serious complication of so-called "filarial" and bacterial non-filarial lymphedema of the limb, affecting skin, lymphatics and lymph nodes. In our previous studies, we demonstrated that more than 60% of patients revealed presence of bacterial isolates in deep tissues, tissue fluid and lymph from the lymphedematous limbs. The question remained open whether elimination or suppression of bacteria dwelling in lymphedematous tissues by administration of low doses of penicillin for long time periods would prevent recurrence of DLA attacks. In this study, we retrospectively evaluated a self/community-selected group of patients with lymphedema of the lower limbs with respect to the efficacy of long-acting penicillin in preventing episodes of DLA. There were no microfilariae or anti-filarial antibodies detected in the investigated group. The questions we asked were: (a) how effective is the benzathine penicillin in preventing recurrences of DLA attacks and (b) how does its long-term administration influence the bacterial spectrum of leg skin, deep tissues, lymph and lymph nodes and sensitivity to antibiotics. Two randomly selected groups of patients, receiving and not receiving penicillin during the same period of time, were compared. Evidently lower recurrence rate of DLA was observed in the treated group (p < 0.002). There was increased prevalence of cocci and gram-positive bacilli with a concomitant decrease of gram-negative bacilli on the foot and calf skin surface. Simultaneously, decreased prevalence of gram-positive cocci and gram-negative bacilli isolates in limb deep tissues and lymph was seen. No resistance to penicillin and other tested antibiotics developed in isolates from the skin surface, deep tissues and lymph. We conclude that long-lasting penicillin is effective in preventing recurrent DLA attacks.

Effects of recombinant human growth hormone on intestinal translocation of bacteria and endotoxin in rats with obstructive jaundice.

BACKGROUND: Extrahepatic biliary obstruction promotes intestinal translocation of bacteria and endotoxin and this process is an important cause of morbidity and mortality in patients with jaundice. This study was undertaken to investigate the effect and mechanism of recombinant human growth hormone(rhGH) and to alleviate intestinal translocation of bacteria and endotoxin in murine obstructive jaundice. METHODS: A group of 42 Wistar rats were divided into 3 groups:sham operation(SO), bile duct ligation (BDL), and BDL and rhGH treatment(rhGH). By the end of the experiment, on day 7, the animals were killed, and their liver function and serum endotoxin were measured, bacterial cultures of the liver, kidney and mesenchymal lymph were made. Terminal ileum mucosa was observed under an electron microscope. RESULTS: Liver function was improved more significantly in the rhGH group than in the BDL group. The value of endotoxin in the rhGH group was 0.38+/-0.03 EU/ml, significantly lower than that in the BDL group(0.65+/-0.04 EU/ml, P < 0.01), and similar to that in the SO group (0.30+/-0.02 EU/ml, P > 0.05). The rate of bacteria translocation in the liver, kidney and mesenteric lymph was much higher in the BDL group than in other two groups. The rate of bacteria translocation in mesenteric lymph was 64.29%, significantly higher than that in the SO group and the rhGH group (P < 0.05). There was no significant difference in bacteria translocation rate between the SO group and the rhGH group (P > 0.05). Under an electron microscope, ileum mucosa epithelial cells in the BDL group were necrotic, and organelle were markedly metamorphic. In the rhGH group, ultrastructural changes were less evident or similar to those in the SO group. CONCLUSION: rhGH has significant protective effects on intestinal mucosa barrier in obstructive jaundice, and reduces intestinal translocation of bacteria and endotoxin.

Intestinal bacterial overgrowth induces the production of biologically active intestinal lymph.

OBJECTIVE: We have previously documented that gut-derived lymph from rats subjected to trauma plus hemorrhagic shock (T/HS) is injurious to vascular endothelial cells and activates neutrophils (PMNs), two key events in postshock organ injury. Because T/HS leads to gut injury, intestinal bacterial overgrowth, and the loss of gut barrier function, the relative role of gut injury as opposed to intestinal bacterial overgrowth per se in the pathogenesis of biologically active intestinal lymph is unclear. We therefore studied whether mesenteric lymph can injure endothelial cells and/or active PMNs in an intestinal bacterial overgrowth model where there is no gut injury (monoassociation). METHODS: Bacterial overgrowth was established in male rats by treating the animals with 4 days of oral antibiotics followed by administration of a nonpathogenic, streptomycin-resistant strain of Escherichia coli C25. Mesenteric lymph was then collected from rats with normal flora and from E. coli C25 monoassociated rats. Its effects were tested on human umbilical vein endothelial cells (HUVECs) and human PMNs. As an additional control, lymph was collected from antibiotic-decontaminated rats that received antibiotics but were not colonized with E. coli C25. RESULTS: As compared with medium, normal flora intestinal lymph, antibiotic-decontaminated lymph, or portal plasma from the monoassociated rats, mesenteric lymph from the monoassociated rats killed HUVECs and increased the permeability of a HUVEC monolayer. In contrast to the effects on HUVECs, lymph from the monoassociated rats did not increase PMN CD11b expression or prime PMNs for an augmented respiratory burst, as compared with lymph from the rats with normal flora or from antibiotic-decontaminated rats. The effects of lymph from the monoassociated rats was not caused by bacteria, because these lymph samples were sterile. CONCLUSION: These results indicate that disruption of the normal intestinal microflora resulting in bacterial overgrowth with enteric bacilli may participate in the production of mesenteric lymph that is injurious to endothelial cells in shock, but this mechanism does not appear to be significantly involved in the activation of PMNs.

T and B cell repertoire in gastric lymph follicles in children with Helicobacter pylori infection.

Helicobacter pylori infection has been implicated in the development of gastrointestinal malignancy in adults and children. The histopathological processes that lead to such development are unknown. We compared the immune cell repertoire of mucosal lymph follicles in children with H. pylori infection to B cell type mucosal associated lymphoid tissue (MALT)-lymphoma of adults. The B and T cell populations residing within the lymph follicles and/or within B cell type MALT lymphoma were characteriZed by an immunohistochemical technique, utilizing B and T cell markers including: CD3, CD4, CD8 (T cells); CD20, CD40, GD74, BLA36, CD80, CD86 (B cells). Stain intensity was compared between the samples. T cell repertoire was observed within the lymph follicles, but not in the B cell MALT-lymphoma specimens. No significant difference was observed between the staining of CD40, CD74, CD8, and BLA36. The B cell markers, CD80 and CD86, were found within the centrocytic zone of the lymph follicle. In the B cell repertoire, no significant difference was observed between the lymph follicles of children with H. pylori infection and the adult MALT-lymphoma specimens except in CD20. B and T cells were in close anatomical proximity, enabling them to interact and exchange immunological information.

Bacteriological studies of blood, tissue fluid, lymph and lymph nodes in patients with acute dermatolymphangioadenitis (DLA) in course of 'filarial' lymphedema.

Filarial lymphedema is complicated by frequent episodes of dermatolymphangioadenitis (DLA). Severe systemic symptoms during attacks of DLA resemble those of septicemia. The question we asked was whether bacterial isolates can be found in the peripheral blood of patients during the episodes of DLA. Out of 100 patients referred to us with 'filarial' lymphedema 14 displayed acute and five subacute symptoms of DLA. All were on admission blood microfilariae negative but had a positive test in the past. Blood bacterial isolates were found in nine cases, four acute (21%) and five subacute (26%). In 10 acute cases blood cultures were found negative. Six blood isolates belonged to Bacilli, four to Cocci and one was Sarcina. To identify the sites of origin of bacterial dissemination, swabs taken from the calf skin biopsy wounds and tissue fluid, lymph and lymph node specimens were cultured. Swabs from the calf skin biopsy wound contained isolates in nine (47%) cases. They were Bacilli in nine, Cocci in three, Acinetobacter and Erwinia in two cases. Tissue fluid was collected from 10 patients and contained Bacilli in four (40%) and Staphylococci in three (30%). Lymph was drained in four patients and contained isolates in all samples (100%). They were Staphylococcus epidermis, xylosus and aureus, Acinetobacter, Bacillus subtilis and Sarcina. Three lymph nodes were biopsied and contained Staphylococcus chromogenes, xylosus, Enterococcus and Bacillus cereus. In six cases the same phenotypically defined species of bacteria were found in blood and limb tissues or fluids. In the 'control' group of patients with lymphedema without acute or subacute changes all blood cultures were negative. Interestingly, swabs from biopsy wound of these patients contained isolates in 80%, tissue fluid in 68%, lymph in 70% and lymph nodes in 58% of cases. In healthy controls, tissue fluid did not contain bacteria, and lymph isolates were found only in 12% of cases. This study demonstrates that patients with acute episodes of DLA reveal bacteremia in a high percentage of cases. Diversity of blood and tissue bacterial isolates in these patients points to a breakdown of the skin immune barrier in lymphedema and subsequently indiscriminate bacterial colonization of deep tissues and spread to an blood circulation.

The effect of lymphatic blockage on the amount of endotoxin in portal circulation, nitric oxide synthesis, and the liver in dogs with peritonitis.

This study was performed to investigate the effect of lymphatic blockage on the amount of endotoxin in portal venous blood, nitric oxide synthesis, the release of aspartate aminotransferase (AST) from the liver, hepatic damage, and survival in an experimental model of dogs with peritonitis. The dogs were divided into a control group (group 1), an unligated thoracic duct peritonitis group (group 2), and a ligated thoracic duct peritonitis group (group 3). Peritoneal fluid and blood from the portal vein and femoral artery were taken for peritoneal culture, endotoxin, and AST assay, respectively, and liver biopsies were performed to assess for hepatic damage and for nitric oxide assay. There was a higher bacteria count in the peritoneal fluid from group 3 than in that from group 2 (P < 0.0001). Bacteria grew in all of the blood cultures from the group 2 animals, but growth was seen only in blood cultures from four of the group 3 animals. The levels of endotoxin, nitrite, and AST levels in group 3 were significantly increased in comparison with those in group 2 (P < 0.0001). Extensive hepatocellular necrosis with hemorrhage was observed in the livers of the group 3 animals, and all of them died within 48 h. The results of this study suggest that the blockage of lymph flow has a negative effect on liver and survival in dogs with peritonitis, and that hepatic damage is directly related to the amount of endotoxin to which the liver is exposed.

The effect on survival of thoracic duct ligation in experimental peritonitis.

BACKGROUND/AIMS: It has been shown that systemic bacteremia and endotoxemia in peritonitis is mainly related to lymphatic transport via the thoracic duct. This study was performed to investigate the effect on mortality of thoracic duct ligation in experimental peritonitis. METHODOLOGY: Thirty dogs were divided into three groups. Groups I, II, and III were control, unligated, and ligated thoracic duct peritonitis groups, respectively. Liver biopsy, blood and peritoneal fluid cultures were taken and survival time was established. RESULTS: Bacteria were determined in peritoneal fluid in all animals in groups II and III. Growing bacteria numbers in group III were two times higher than in group II. While bacterium was grown on blood cultures in all group II animals, growing was determined on blood cultures in only 2 animals in group III. Diffuse necrosis was determined in the liver of 2 animals who died within 72 hours in group II. Another 8 animals had minimal focal necrosis in their livers. Diffuse and progressive necrosis was determined in the liver of all animals in group III. The difference between liver necrosis in group II and group III was found to be statistically significant (p = 0.002). CONCLUSIONS: This experimental study demonstrates that thoracic duct ligation decreases bacteremia rates clearly but that mortality increases significantly.

Thoracic duct in patients with multiple organ failure: no major route of bacterial translocation.

OBJECTIVE: To determine whether translocation of bacteria or endotoxin occurred into the thoracic duct in patients with multiple organ failure (MOF). SUMMARY BACKGROUND DATA: Translocation of bacteria or endotoxin has been proposed as a causative factor for MOF in patients without an infectious focus, although it has rarely been demonstrated in patients at risk for MOF. Most studies have investigated the hematogenic route of translocation, but it has been argued that lymphatic translocation of bacteria or endotoxin by the thoracic duct is the major route of translocation. METHODS: The thoracic duct was drained for 5 days in patients with MOF caused either by generalized fecal peritonitis (n = 4) or by an event without clinical and microbiologic evidence of infection (n = 4). Patients without MOF who were undergoing a transthoracic esophageal resection served as controls. In lymph and blood, concentrations of endotoxin, proinflammatory cytokines, and antiinflammatory cytokines were measured. RESULTS: Endotoxin concentrations in lymph and blood of patients with MOF ranged from 39 to 63 units per liter and were not significantly different from concentrations in patients without MOF. The quantity of endotoxin transported by the thoracic duct in the study group was small. In patients with MOF, low levels of proinflammatory cytokines and high levels of antagonists of these cytokines were found. CONCLUSION: This study provides evidence that translocation (especially of endotoxin) occurs into the thoracic duct. However, these data do not support the concept that the thoracic duct is a major route of bacterial translocation in patients with MOF.