Jl Menchaca-Diaz

Microcirculatory evaluation in sepsis: a difficult task.

Microcirculatory dysfunction plays a pivotal role in the pathogenesis of severe sepsis and septic shock; hence, microcirculation blood flow monitoring has gained increasing attention. However, microcirculatory imaging is still investigational in human sepsis and has not yet been incorporated into routine clinical practice for several reasons, including the difficult interpretation of microcirculation imaging data, difficulty to draw a parallel between sublingual microcirculation imaging and organ microcirculation dysfunction, as well as the absence of microvessel dysfunction parameters defining sequential microcirculatory changes from the early to late stages of the disease, which could aid in the context of therapeutic approaches and of prognostic parameters. The purpose of this review was to bridge the experimental abdominal organ microvascular derangement kinetics and clinical aspects of microcirculatory findings in the early phase of severe sepsis/septic shock.

Typical and atypical enteropathogenic Escherichia coli bacterial translocation associated with tissue hypoperfusion in rats

Although enteropathogenic Escherichia coli (EPEC) are well-recognized diarrheal agents, their ability to translocate and cause extraintestinal alterations is not known. We investigated whether a typical EPEC (tEPEC) and an atypical EPEC (aEPEC) strain translocate and cause microcirculation injury under conditions of intestinal bacterial overgrowth. Bacterial translocation (BT) was induced in female Wistar-EPM rats (200-250 g) by oroduodenal catheterization and inoculation of 10 mL 10(10) colony forming unit (CFU)/mL, with the bacteria being confined between the duodenum and ileum with ligatures. After 2 h, mesenteric lymph nodes (MLN), liver and spleen were cultured for translocated bacteria and BT-related microcirculation changes were monitored in mesenteric and abdominal organs by intravital microscopy and laser Doppler flow, respectively. tEPEC (N = 11) and aEPEC (N = 11) were recovered from MLN (100%), spleen (36.4 and 45.5%), and liver (45.5 and 72.7%) of the animals, respectively. Recovery of the positive control E. coli R-6 (N = 6) was 100% for all compartments. Bacteria were not recovered from extraintestinal sites of controls inoculated with non-pathogenic E. coli strains HB101 (N = 6) and HS (N = 10), or saline. Mesenteric microcirculation injuries were detected with both EPEC strains, but only aEPEC was similar to E. coli R-6 with regard to systemic tissue hypoperfusion. In conclusion, overgrowth of certain aEPEC strains may lead to BT and impairment of the microcirculation in systemic organs.

Kinetic study of gut and systemic tissue perfusion following one challenge of bacterial translocation

The pathogenesis of sepsis and multiple organ failure has been associated with bacterial translocation (BT). In a previous study we observed intestinal and systemic tissue hypoperfusion 2 hours after a BT process. In this study we examined the perfusion kinetics a longer period after one unique challenge of BT.

Sepsis provokes host's microbiota overgrowth of commensal Gram-negative bacteria and subsequent induction of bacterial translocation in rats

The literature has shown the participation of intestinal microbiota in the genesis of primary infections as well as of sepsis. In this study we examine the role of sepsis on the microbiota by examining the most frequently recovered Gram-negative bacteria (G-).

Which is the worst factor in the sepsis aggravation: translocated bacterial amount or the gut-associated lymphoid tissue activation?

The intestinal hypothesis of sepsis has been attributed to bacterial translocation (BT), and the aggravation of sepsis is related to the increased vascular permeability state that potentates the BT index. In this study we examined the BT index during sepsis with or without mesenteric lymph exclusion.

Influence of bacterial translocation in the genesis of the microcirculation: hypoperfusion in sepsis.

Increasing evidence suggests that bacterial translocation (BT) has been implicated in the pathogenesis of sepsis and multiple organ failure. In this study we examined the role of the mesenteric lymph during the BT process on the intestinal and systemic tissue perfusion in association with nonlethal sepsis.

Comparison between intravital microscopy and laser Doppler microcirculation monitoring methods in experimental sepsis: preliminary results

Sepsis (S) produces regional perfusion abnormalities by causing vasodilatation and blood flow redistribution, and this process mostly affects the mesenteric circulation. In addition, gut mucosal hypoperfusion can perpetuate the inflammatory process and contributes to the multiple organ failure. Thus, following experimental sepsis induction we examined gut blood flow by intravital microscopy and the gut tissue perfusion by laser Doppler, in order to detect the onset of the intestinal microcirculation changes at the acute phase of sepsis.

Can bacterial translocation be a beneficial event

Infection is a major concern in intestinal transplant recipients. Bacterial migration to extraintestinal sites is a central component of the gut hypothesis of sepsis. However, some studies have cited the beneficial effects of bacterial translocation (BT) on the host acquired immune system. We evaluated the role of previous BT on a subsequent BT challenge, examined the BT index in organs as well as changes in white blood cell (WBC) count in mesenteric lymph and blood for correlation with outcomes. Wistar rats (n = 60) were divided into a BT group (n = 20), which underwent inoculation of 10 mL of 10(10) CFU/mL Escherichia coli R-6 confined to the small intestine as opposed to a BT1-14 group (n = 20), which underwent the BT procedure on days 1 and 14 or a S1-BT14 group (n = 20) that received 10 mL of saline on day 1 and the BT procedure on day 14. Half of the animals were killed 2 hours following the BT procedure. Samples from different compartments were collected for culture. Mesenteric lymph and peripheral blood were examined for WBC counts. The other half of the hosts was subjected to outcome evaluation concerning weight gain and mortality. Animals undergoing double BT showed a significantly lower index of bacterial recovery (liver, spleen, and blood) compared with those having a single BT (P < .05). The WBC count of mesenteric lymph cells after double BT was similar to naïve animals, but significantly lower than the single BT group (P < .05). The outcome was unchanged among double BT versus other groups. A previous BT challenge was efficient to generate a host-defense mechanism against a second BT episode induced by intestinal overgrowth with the same bacterial strain.

The gut mesenteric lymph during bacterial translocation carries factor(s) related to mortality in sepsis

Experimental and clinical studies have shown that bacterial translocation (BT) has been implicated in the pathogenesis of sepsis and multiple organ dysfunction syndrome (MODS). In this study we examined the role of the intestinal lymph during the BT process on the clinical outcome in a pre-established sepsis state.

Iron-deficiency anemia increases intestinal bacterial translocation in rats

Bacterial translocation has been related as the main causal event in the genesis of the systemic infection. Particularly in pediatric patients, worse prognosis of systemic infection has been related to malnourishment, impaired immune response and other debilitating diseases. In this study we therefore decided to examine the effect of iron-deficiency anemia in bacterial translocation (BT).