scholarly journals Increased glycine absorption rate associated with acute bacterial infections in man

1973 ◽  
Vol 29 (3) ◽  
pp. 377-386 ◽  
Author(s):  
G. C. Cook
Keyword(s):  
Bacterial Infections ◽  
Absorption Rate ◽  
Reference Group ◽  
Normal Subjects ◽  
Double Lumen Tube ◽  
Present Observation ◽  
Chronic Infections ◽  
Jejunal Segment ◽  
Acute Bacterial Infections

1. Glycine absorption rate from a 300 mm jejunal segment was determined in vivo in four Zambian African subjects with acute, and four with chronic, respiratory infections. Glycine solutions (100, 150 and 250 mmol/l) were perfused, by means of a double-lumen tube technique. The results were compared with those for four relatively normal Zambian African subjects (‘reference’ group) previously studied. The group with acute-infections had a significantly higher mean absorption rate than the reference or chronic-infection group.2. Glycine absorption results from a 100 mmol/l glycine solution in an additional twenty-four Zambian African subjects have also been analysed. When results for the thirty-six subjects were combined, those with acute bacterial infections had a significantly higher mean absorption rate than the normal subjects or those with chronic infections. For the twenty-one normal subjects there was a significant positive correlation between the individual absorption rates and serum total globulin and γ-globulin concentrations.3. It seems likely that the rapid catabolism of protein associated with infection is counteracted by an increase in amino acid absorption rate. In subjects on a low-protein diet that mechanism would be limited. The deterioration in nutritional status during infections in developing countries could therefore be partly explained by the present observation.

scholarly journals Jejunal absorption rates of glucose, glycine and glycylglycine in Zambian African adults with malnutrition

1974 ◽  
Vol 32 (3) ◽  
pp. 503-513 ◽  
Author(s):  
G. C. Cook
Keyword(s):  
Bacterial Infections ◽  
Absorption Rate ◽  
Clinical Evidence ◽  
Gastrointestinal Disease ◽  
Systemic Infection ◽  
Abdominal Tuberculosis ◽  
Double Lumen Tube ◽  
Albumin Concentration ◽  
Control Subjects

1. Absorption rates of glucose (from a 200 mM solution), glycine (from a 100 mM solution), and glycylglycine (from a 50 mM solution) have been estimated in six Zambian African adults with clinical evidence of malnutrition. A double-lumen tube technique was used to determine absorption rates from a 300 mm section of jejunum in vivo.2. Two of the subjects had ileal tuberculosis and Kaposi's sarcoma respectively. A third probably had abdominal tuberculosis. Three of them had pellagra. Mean serum albumin concentration was 24 (14–43) g/l. Absorption rates have been compared with those in Zambian Africans (control subjects), previously studied, who had no clinical evidence of malnutrition, systemic infection or of gastrointestinal disease.3. Mean glucose, glycine and glycylglycine absorption rates in the malnourished subjects were not significantly different from those in the control subjects. Mean net water absorption rate from the glucose solution was similar in the malnourished subjects and controls; during the glycine and glycylglycine perfusions the mean net absorption rate was, however, significantly lower in the malnourished subjects (P < 0.01 and P < 0.05 respectively); mean net water transfer during the glycine perfusions was towards the jejunal lumen in the malnourished subjects. One subject with pellagra had an abnormal excretion of D-xylose after a 25 g oral load; all other tests were normal.4. It seems probable that malnutrition must be very severe, with jejunal mucosal abnormalities, before absorption rates of glucose, glycine and glycylglycine are significantly altered. The present study does not support the view that subclinical malnutrition is important in producing malabsorption of dietary components in Zambian African subjects. Systemic bacterial infections, and raised serum γ-globulin and immunoglobulin IgG concentrations have previously been associated with an impairment of glucose absorption rate in Zambian African subjects; those factors seem much more likely than subclinical malnutrition to be relevant, in the context of absorption, in the pathogenesis of overt malnutrition.

scholarly journals Independent jejunal mechanisms for glycine and glycylglycine transfer in man in vivo

1973 ◽  
Vol 30 (1) ◽  
pp. 13-19 ◽  
Author(s):  
G. C. Cook
Keyword(s):  
Absorption Rate ◽  
Clinical Evidence ◽  
Double Lumen Tube ◽  
Transport Mechanisms ◽  
Perfusion System ◽  
Double Lumen ◽  
Lumen Tube ◽  
Jejunal Segment ◽  
Rate Of Absorption

1. Rates of absorption of glycine and glycylglycine from a 300 mm jejunal segment were compared in vivo when those compounds were given alone or together to six Zambian African subjects who had no clinical evidence of malnutrition or of gastro-intestinal disease. Solutions containing (A) glycine (100 mmol/1), (B) glycine (100 mmol/l)+glycylglycine (50 mmol/l), and (C) glycylglycine (50 mmol/l) were infused into the upper jejunum by means of a double-lumen tube perfusion system.2. Rate of absorption of glycine was significantly higher from the glycylglycine solution (C) than from the glycine solution (A). Glycine absorption rate from solution B (glycine+glycylglycine) was very similar to the sum of absorption rates of glycine from solutions A and C in each subject. Luminal disappearance rate of glycylglycine from solutions C and B were very similar; however, the rate was significantly greater than the total glycine absorption rate from solution C and indicates back-diffusion of glycine into the lumen after glycylglycine hydrolysis.3. The results are interpreted as indicating that the transport mechanisms for glycine and glycylglycine in man are partly, and possibly wholly, separate.

Comparison of Intestinal Absorption Rates of Glycine and Glycylglycine in Man and the Effect of Glucose in the Perfusing Fluid

1972 ◽  
Vol 43 (3) ◽  
pp. 443-453 ◽  
Author(s):  
G. C. Cook
Keyword(s):  
Absorption Rate ◽  
Kinetic Curve ◽  
Glucose Absorption ◽  
Double Lumen Tube ◽  
Jejunal Segment ◽  
The Mean ◽  
The Difference ◽  
Mean Glucose ◽  
Effect Of Glucose

1. Using a double-lumen tube perfusion system the rates of glycine, glycylglycine, and glycylglycine and glucose absorption from a 30-cm jejunal segment have been studied in vivo in a group of relatively normal Zambian African subjects. 2. To determine the kinetic curve for glycine absorption, four subjects were given consecutive perfusions of 50, 100 and 150 mm-glycine. 3. Six other subjects had consecutive perfusions of (1) a 100 mm-glycine and (2) a 50 mm-glycylglycine solution. Five of the six had a higher absorption rate of glycine from the glycylglycine solution. When data from a further six similar subjects in another study are included, the mean rate of glycine absorption is significantly greater from the glycylglycine compared with the glycine solution (P < 0·001). 4. A further six subjects were given consecutive perfusions of (1) 50 mm-glycylglycine, (2) 50 mm-glycylglycine and 200 mm-glucose, and (3) 200 mm-glucose. The absorption rate of glycine from glycylglycine was lower in all subjects when glucose was present in the perfusing fluid (P < 0·01). Although the mean glucose absorption rate was lower when glycylglycine was present in the perfusing fluid, the difference was not significant.

scholarly journals Visualizing the In Vivo Dynamics of Anti-Leishmania Immunity: Discoveries and Challenges

2021 ◽  
Vol 12 ◽  
Author(s):  
Romaniya Zayats ◽  
Jude E. Uzonna ◽  
Thomas T. Murooka
Keyword(s):  
Intravital Microscopy ◽  
Bacterial Infections ◽  
Immune Cell ◽  
Parasitic Infections ◽  
Chronic Infections ◽  
Cell Dynamics ◽  
Host Immune Responses ◽  
Immunological Research ◽  
Primary Focus

Intravital microscopy, such as 2-photon microscopy, is now a mainstay in immunological research to visually characterize immune cell dynamics during homeostasis and pathogen infections. This approach has been especially beneficial in describing the complex process of host immune responses to parasitic infections in vivo, such as Leishmania. Human-parasite co-evolution has endowed parasites with multiple strategies to subvert host immunity in order to establish chronic infections and ensure human-to-human transmission. While much focus has been placed on viral and bacterial infections, intravital microscopy studies during parasitic infections have been comparatively sparse. In this review, we will discuss how in vivo microscopy has provided important insights into the generation of innate and adaptive immunity in various organs during parasitic infections, with a primary focus on Leishmania. We highlight how microscopy-based approaches may be key to providing mechanistic insights into Leishmania persistence in vivo and to devise strategies for better parasite control.

Interferon-γ Mediated Pathways And Mitogen Stimulated Proliferation During And After An Acute Infection

Pteridines ◽  
2018 ◽  
Vol 29 (1) ◽  
pp. 70-79
Author(s):  
Miriam Knoll ◽  
Dietmar Fuchs ◽  
Guenter Weiss ◽  
Rosa Bellmann-Weiler ◽  
Bojana Kovrlija ◽  
...  
Keyword(s):  
Immune System ◽  
Immune Cells ◽  
Bacterial Infections ◽  
Acute Infection ◽  
Interferon Γ ◽  
Immune System Activation ◽  
System Activation ◽  
Acute Bacterial Infections

AbstractBackground: Interferon-γ (IFN- γ) regulates the degradation of tryptophan to kynurenine via induction of indoleamine- 2,3-dioxygenase (IDO). Local tryptophan depletion and accumulation of toxic metabolites might impair the proliferative capacity of lymphocytes. The aim of this study was to assess the actual status of immune system activation of patients with bacterial infection in the acute phase and during convalescence in vivo and in vitro. Parameters of systemic immune system activation were evaluated for associations with proliferative responsiveness of immune cells, and compared with healthy controls. Methods: 24 patients with various acute bacterial infections were included in the group of acutely ill patients. Sixteen patients participated in a follow-up examination after convalescence. The control group consisted of 6 healthy people. To assess the status of immune system activation in vivo, inflammation parameters C-reactive protein and differential blood counts were determined. Neopterin concentrations were measured by enzyme-linked immunosorbent assay (ELISA). Tryptophan and kynurenine measurements were performed with high pressure liquid chromatography (HPLC). Peripheral blood mononuclear cells (PBMCs) were isolated from the patients’ blood and stimulated with concanavalin A (Con A), phytohemagglutinin (PHA) and pokeweed mitogen (PWM) in vitro proliferation rates were evaluated by ³H-thymidine incorporation and neopterin production and tryptophan degradation were determined in supernatants of mitogen stimulated PBMCs. Results: Patients with acute bacterial infections showed reduced tryptophan and elevated neopterin concentrations, which did not normalize after convalescence period. Higher plasma neopterin values and increased IDO-activity were associated with reduced proliferative responses in vitro after stimulation with PHA. Associations were observed during acute infection as well as convalescence. Conclusions: Results of this study show that increased immune system activation in vivo is associated with impaired proliferative responsiveness of immune cells in vitro in acute bacterial infections as well as during convalescence.

scholarly journals The origin of extracellular DNA in bacterial biofilm infectionsin vivo

2019 ◽  
Author(s):  
Maria Alhede ◽  
Morten Alhede ◽  
Klaus Qvortrup ◽  
Kasper Nørskov Kragh ◽  
Peter Østrup Jensen ◽  
...  
Keyword(s):  
Bacterial Infections ◽  
White Blood Cells ◽  
Treatment Strategies ◽  
Bacterial Biofilm ◽  
Extracellular Dna ◽  
Confocal Scanning Laser Microscopy ◽  
Chronic Infections ◽  
Bacterial Aggregates

AbstractExtracellular DNA (eDNA) plays an important role in both the aggregation of bacteria and in the interaction of the resulting biofilms with polymorphonuclear leukocytes (PMNs) during an inflammatory response. Here, transmission electron and confocal scanning laser microscopy were used to examine the interaction between biofilms ofPseudomonas aeruginosaand PMNs in a murine implant model and in lung tissue from chronically infected cystic fibrosis patients. PNA FISH, DNA staining, labeling of PMN DNA with a thymidine analogue, and immunohistochemistry were applied to localize bacteria, eDNA, PMN-derived eDNA, PMN-derived histone H3 (H3), neutrophil elastase (NE), and citrullinated H3 (citH3). Host-derived eDNA was observed surrounding bacterial aggregates but not within the biofilms. H3 localized to the lining of biofilms while NE was found throughout biofilms. CitH3, a marker for neutrophil extracellular traps (NETs) was detected only sporadically indicating that most host-derived eDNAin vivowas not a result of NETosis. Together these observations show that, in thesein vivobiofilm infections withP. aeruginosa, the majority of eDNA is found external to the biofilm and derives from the host.Author summaryThe role of extracellular DNA (eDNA) has been describedin vitroto play a major role in biofilm formation and antibiotic tolerance, but never for biofilm infectionsin vivo.Two important characteristics of human chronic bacterial infections are aggregated bacteria and white blood cells (WBC). Bacteria use eDNA to stabilize biofilms and WBC use eDNA to trap bacteria. Given the importance of eDNA for both bacteria and WBC we show here for the first time that bacterial biofilms do not co-localize with either bacterial or WBC-derived eDNA during chronic infections. Ourin vivofindings show eDNA is located outside biofilms as opposed to incorporated within the biofilm as commonly observedin vitro.We believe that understanding the interplay between biofilms and WBC during chronic infection is essential if we are to elucidate the mechanisms underlying persistent infection and ascertain why WBC fail to eradicate bacteria; this will enable us to develop new treatment strategies.

scholarly journals Entropically driven aggregation of bacteria by host polymers promotes antibiotic tolerance inPseudomonas aeruginosa

2018 ◽  
Vol 115 (42) ◽  
pp. 10780-10785 ◽  
Author(s):  
Patrick R. Secor ◽  
Lia A. Michaels ◽  
Anina Ratjen ◽  
Laura K. Jennings ◽  
Pradeep K. Singh
Keyword(s):  
Biofilm Formation ◽  
Chronic Infection ◽  
Bacterial Infections ◽  
Genotoxic Stress ◽  
Antibiotic Tolerance ◽  
Key Factors ◽  
Chronic Infections ◽  
New Therapeutic Approaches ◽  
Bacterial Aggregation

Bacteria causing chronic infections are generally observed living in cell aggregates suspended in polymer-rich host secretions, and bacterial phenotypes induced by aggregated growth may be key factors in chronic infection pathogenesis. Bacterial aggregation is commonly thought of as a consequence of biofilm formation; however the mechanisms producing aggregation in vivo remain unclear. Here we show that polymers that are abundant at chronic infection sites cause bacteria to aggregate by the depletion aggregation mechanism, which does not require biofilm formation functions. Depletion aggregation is mediated by entropic forces between uncharged or like-charged polymers and particles (e.g., bacteria). Our experiments also indicate that depletion aggregation of bacteria induces marked antibiotic tolerance that was dependent on the SOS response, a stress response activated by genotoxic stress. These findings raise the possibility that targeting conditions that promote depletion aggregation or mechanisms of depletion-mediated tolerance could lead to new therapeutic approaches to combat chronic bacterial infections.

scholarly journals STUDIES ON THE PATHOGENESIS OF FEVER

1964 ◽  
Vol 119 (5) ◽  
pp. 715-726 ◽  
Author(s):  
Richard D. Berlin ◽  
W. Barry Wood
Keyword(s):  
Bacterial Infections ◽  
The Other ◽  
Release Mechanism ◽  
Polymorphonuclear Leucocytes ◽  
Endogenous Pyrogen ◽  
Release Process ◽  
Polystyrene Beads ◽  
Other Hand ◽  
Acute Bacterial Infections

1. Phagocytosis promotes the release of endogenous pyrogen from polymorphonuclear leucocytes. 2. The release of pyrogen, though initiated by the phagocytic event, is not synchronous with it. 3. The postphagocytic release mechanism is not inhibited by sodium fluoride and, therefore, appears not to require continued production of energy by the cell. 4. The release process, on the other hand, is inhibited by arsenite, suggesting the participation of one or more sulfhydryl-dependent enzymes in the over-all reaction. 5. Particle for particle, the ingestion of heat-killed rough pneumococci causes the release of approximately 100 times as much pyrogen as the ingestion of polystyrene beads of the same size. 6. The pyrogen release mechanism of polymorphonuclear leucocytes separated directly from blood, unlike that of granulocytes in acute inflammatory exudates, is not readily activated by incubation of the cells in K-free saline. Despite this difference, both blood and exudate leucocytes following phagocytosis release large amounts of pyrogen, even in the presence of K+. The fact that the postphagocytic reaction is uninhibited by the concentrations of K+ which are present in plasma and extracellular fluids, suggests that this mechanism of pyrogen release may well operate in vivo. 7. As might be expected from the foregoing observations, the intravenous injection of a sufficiently large number of heat-killed pneumococci causes fever in the intact host. Intravenously injected polystyrene beads, on the other hand, are significantly less pyrogenic. Evidence is presented to support the conclusion that the fever in both instances is caused by pyrogen released from the circulating leucocytes which have phagocyted the injected particles. 8. The possible relationships of these findings to the pathogenesis of fevers caused by acute bacterial infections are discussed.

scholarly journals CHANGES PRODUCED IN MOUSE PLASMA PROTEINS BY ACUTE BACTERIAL INFECTIONS

1961 ◽  
Vol 114 (3) ◽  
pp. 311-325 ◽  
Author(s):  
Curtis A. Williams ◽  
Courtney T. Wemyss
Keyword(s):  
Plasma Proteins ◽  
Bacterial Infections ◽  
Acute Infection ◽  
Laboratory Animals ◽  
Striking Increase ◽  
Acute Infections ◽  
Hospital Patients ◽  
Acute Bacterial Infections

The immunoelectrophoretic patterns of plasma proteins from mice are altered significantly by acute infections. Some proteins are dissociated into two or more components, some showed striking increase in plasma concentration, others are depleted, and certain ones appear which are undetectable in normal samples. ß1-C dissociated into two electrophoretic components under a variety of conditions in addition to infections. Endotoxins and killed organisms in vivo, and specific precipitate absorption, heat and aging in vitro produced this change. Endotoxins injected into mice also induced a rise in haptoglobin though not as sharply or predictably as acute infection. Preliminary results with samples from hospital patients with acute diseases are discussed. It was concluded that study of experimental diseases in laboratory animals by these techniques could provide a fruitful basis for the investigation of the plasma protein changes in similar human diseases.

scholarly journals Evaluation of Biofilm Formation and Anti-biofilm Properties of Peganum Harmala and Crocus Sativus in Shigella Flexneri Clinical Isolates

2019 ◽  
Vol 13 (1) ◽  
pp. 297-300
Author(s):  
Mahsa Jalili ◽  
Mansour Amraei ◽  
Nourkhoda Sadeghifard ◽  
Sobhan Ghafourian
Keyword(s):  
Biofilm Formation ◽  
Bacterial Infections ◽  
Shigella Flexneri ◽  
Herbal Medicines ◽  
Clinical Isolates ◽  
Crocus Sativus ◽  
Peganum Harmala ◽  
Chronic Infections ◽  
Traditional Use

Background: Biofilm formation causes many serious problems in the treatment of bacterial infections. In addition, chronic infections due to biofilm formation can pose a huge burden to the health care systems. Also, many bacteria are biofilm producers as an important strategy for pathogenicity. Furthermore, the traditional use of herbal medicines such as Peganum harmala and Crocus sativus in Iran is interesting. Objective: The purpose of the current study was to investigate the biofilm formation in Shigella flexneri clinical isolates and to evaluate the anti-biofilm properties of P. harmala and C. sativus on Shigella flexneri clinical isolates. Methods: For the study purpose, Thirty S.flexneri clinical isolates were collected from Ahvaz, Iran. Then, the collected bacteria were subjected to biofilm formation assay. Afterward, P. harmala and C. sativus were applied as an anti-biofilm formation in S. flexneri. Results & Conclusion: Our results demonstrated that a significant number of samples were identified as strong biofilm producers. Then, P. harmala and C . sativus in a concentration of 30μg/ml and 60μg/ml were able to eradicate a strong biofilm formation in S. flexneri, respectively. In addition, it seems that more extensive studies and in vivo research should be done to confirm their properties.

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