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Related Concept Videos

Pneumonia I: Introduction01:29

Pneumonia I: Introduction

Pneumonia is an infection of the lower respiratory tract that leads to inflammation of the lung parenchyma, often resulting in the accumulation of inflammatory exudate in the alveoli and airways. Unlike the watery, low-protein fluid exudate in pulmonary edema, the exudate in this case is a thick fluid rich in immune cells, proteins, and debris produced during infection and inflammation.This impairs gas exchange and can lead to consolidation of lung tissue. The infection may be caused by a...
Pneumonia I: Introduction01:30

Pneumonia I: Introduction

Pneumonia is an acute respiratory infection that targets the lungs, specifically the alveoli. These tiny air sacs, essential for oxygen exchange, become engorged with pus and fluid, severely hindering breathing, decreasing oxygen absorption, and causing significant pain and discomfort during respiration.
Risk Factors
Various factors influence the likelihood of developing pneumonia. Age plays a crucial role, with infants, children under two, and individuals over 65 at increased risk due to their...
Pneumothorax-I01:26

Pneumothorax-I

A pneumothorax is a condition where air builds up in the space between the lung and the chest wall, causing the lung to collapse. This condition arises when air enters the space between the parietal and visceral pleura, disrupting the negative pressure essential for lung inflation. This can lead to a partial or complete collapse of the lung.
Pneumothorax can be even further classified as spontaneous, traumatic, and tension pneumothorax.
Pneumonia III: Complications and Assessment01:30

Pneumonia III: Complications and Assessment

Pneumonia poses the potential for numerous complications that warrant consideration. These complications include the following:
Pneumonia II: Pathophysiology01:29

Pneumonia II: Pathophysiology

The pathophysiology of pneumonia involves the following steps:
Atypical Pneumonia01:14

Atypical Pneumonia

Atypical pneumonia, often caused by Mycoplasma pneumoniae, is a form of pulmonary infection that differs from the classical presentation of bacterial pneumonia in both its cause and clinical symptoms. Mycoplasma pneumoniae is a pleomorphic bacterium notable for its lack of a rigid cell wall. This structural characteristic imparts resistance to beta-lactam antibiotics and significantly influences the bacterium’s behavior within the human host.Other pathogens responsible for the disease include...

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Following in Real Time the Impact of Pneumococcal Virulence Factors in an Acute Mouse Pneumonia Model Using Bioluminescent Bacteria
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Following in Real Time the Impact of Pneumococcal Virulence Factors in an Acute Mouse Pneumonia Model Using Bioluminescent Bacteria

Published on: February 23, 2014

PNEUMOCOCCUS HEMOTOXIN.

R Cole1

  • 1Hospital of The Rockefeller Institute for Medical Research.

The Journal of Experimental Medicine
|October 30, 2009
PubMed
Summary
This summary is machine-generated.

Pneumococcal bacterial bodies contain a preformed hemolytic endotoxin that damages red blood cells. This potent toxin exhibits antigenic properties and can be neutralized by cholesterol.

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Following in Real Time the Impact of Pneumococcal Virulence Factors in an Acute Mouse Pneumonia Model Using Bioluminescent Bacteria
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Area of Science:

  • Microbiology
  • Immunology
  • Toxicology

Background:

  • Pneumococci are a significant bacterial pathogen.
  • Understanding bacterial components is crucial for developing targeted therapies.
  • The hemolytic activity of bacterial extracts has been previously observed.

Purpose of the Study:

  • To characterize the hemolytic substance derived from pneumococcal bodies.
  • To investigate the properties and potential endotoxic nature of this substance.
  • To explore its antigenic capabilities and interactions with host immune components.

Main Methods:

  • Extraction of pneumococcal bodies using sodium cholate, autolysis, or physical disruption.
  • Assaying hemolytic activity against various red blood corpuscles (rabbit, sheep, guinea pig, human).
  • Testing the stability of the hemolytic substance (filtration, trypsin digestion) and its inhibition by cholesterol.
  • Evaluating antigenic properties by injecting the substance into rabbits and sheep and assessing serum inhibitory capacity.

Main Results:

  • Pneumococcal extracts demonstrated potent hemolytic activity against multiple red blood cell types.
  • The hemolytic substance was found to be labile, sensitive to filtration and trypsin, and inhibited by cholesterol.
  • Injected animals developed serum antibodies capable of inhibiting the hemolytic action, indicating antigenic properties.

Conclusions:

  • Pneumococcal bodies contain a preformed, hemolytic endotoxin.
  • This endotoxin is responsible for the observed red blood cell lysis.
  • The endotoxin possesses significant antigenic properties, eliciting an immune response.