A fermentation-inhibition test for the measurement of growth-inhibiting anti-body to acid-producing mycoplasmas was performed in microtitre plastic plates. M. pneumoniae, M. fermentans and the ...Negroni agent were selected for study. Antibody could be titrated since specific antiserum inhibited mycoplasma growth and the concomitant production of acid, thus preventing a change in colour of phenol red which was incorporated in the growth medium. It was essential to use unheated horse serum as a component of the growth medium. The inhibitory effect of specific antiserum was much decreased when the horse serum was heat-inacti-vated, indicating the need for a heat-labile accessory factor. The additional use of unheated guinea-pig serum was essential for demonstrating the growth-inhibiting effect of specific antiserum on the Negroni agent. The test was reproducible, specific and sensitive. Sixteen-fold or greater antibody rises were demonstrated in paired sera from volunteers infected with M. pneumoniae. Tests with ninety-five random adult sera showed that 22% had antibody to M. pneumoniae at a titre of 1/5 or more and 13–5% had antibody to M. fermentans.
Peripheral edema, hypoproteinemia, and increased fluid requirements are characteristically seen with sepsis. Our purpose was to determine whether the soft tissue edema is caused by a direct vascular ...injury from sepsis or is secondary to hypoproteinemia. We determined the effect of endotoxin on peripheral (soft tissue) microvascular integrity using lymph flow (QL) and lymph/plasma (L/P) protein ratio to reflect fluid flux and increased permeability. Response was compared with that seen in the lung. Fourteen unanesthetized sheep were given intravenous E. coli endotoxin 2 micrograms/kg. Vascular pressures and cardiac output (CO) were maintained constant with the necessary fluid infusion. Lung QL increased two- to fourfold in all animals with lymph being protein-rich, indicating increased permeability. Peripheral QL increased transiently in response to an initial increase in vascular pressure returning rapidly to baseline except in those animals (N = 5) demonstrating hypoproteinemia where QL remained increased by 50 to 75%. The increased QL was totally explained by the degree of protein depletion, with no evidence of increased permeability. To assure an adequate endotoxin exposure to the peripheral microvessels, endotoxin (2 micrograms/kg) was also directly injected into the tissue drained by the soft tissue lymphatic. We noted a characteristic endotoxin pulmonary hypertension phase but, again, no increase in peripheral microvascular permeability was found. We conclude that endotoxemia does not alter peripheral microvascular permeability if tissue perfusion is maintained, while the lung is clearly a target organ. Hypoproteinemia may be responsible for the early edema in soft tissues with sepsis.
Our purpose was to determine whether peripheral soft tissues produce and release prostanoids in response to local sepsis, and whether this mediator release can produce pulmonary dysfunction. ...Escherichia coli endotoxin (2 micrograms/kg in 100 mL of saline) was injected below the hide of the flank in seven unanesthetized sheep. In three additional sheep, ibuprofen (12.5 mg/kg of body weight) was injected with the endotoxin. Thromboxane B2 and 6-keto-PGF1 alpha (prostacyclin) levels were measured in tissue lymph draining the flank, lung lymph, pulmonary artery (Ppa), and aortic plasma. One hour after endotoxin administration, mean PaO2 decreased from 90 to 74 mm Hg and Ppa increased from 22 to 35 mm Hg. Lung lymph flow (QL) increased only 50% with QL being protein poor. No increase in lung or peripheral soft-tissue vascular permeability was noted. Tissue lymph (TxB2) increased from 220 +/- 114 to greater than 10,000 pg/mL with levels in Ppa plasma increasing from 300 +/- 128 to 595 +/- 124 pg/mL and aortic plasma from 270 +/- 141 to 410 +/- 104 pg/mL. Lung lymph TxB2 paralleled aortic values. Peak levels of 6-keto-PGF1 alpha in systemic lymph exceeded 2,000 pg/mL while levels in lung lymph remained relatively constant. The pulmonary injury and the increase in TxB2 was prevented by ibuprofen. We conclude that the response of soft tissue to local endotoxin is to release thromboxane in quantities sufficient to raise plasma levels and to produce hypoxia and pulmonary hypertension. The lung dysfunction is not produced by an increase in lung water or vascular permeability.
Local injection of endotoxin into soft tissues of the flank results in hypoxia and pulmonary hypertension. Our purpose was to determine whether this was caused by tissue prostanoid production or ...production by the lung as is seen with endotoxemia. Twenty-six sheep were prepared with lung and flank tissue lymph fistulae. Thirteen sheep were given 2 micrograms/kg Escherichia coli endotoxin into the flank soft tissue, six of which were pretreated with ibuprofen, 12.5 mg/kg. Thirteen sheep were given intravenous endotoxin, 2 micrograms/kg, with six pretreated with ibuprofen. An early hypertensive phase was noted with both insults characterized by pulmonary hypertension, hypoxia, and increased lung lymph flow (QL). With subcutaneous tissue endotoxin, there was a significant increase in tissue lymph TxB2 and 6-keto-PGF1 alpha when compared to lung lymph and increased values in venous plasma compared to arterial plasma, indicating tissue to be the source. With intravenous endotoxin, lung lymph and aortic plasma levels were significantly higher than tissue lymph and venous plasma, respectively. The hypoxia, hypertension and increased prostanoids were prevented using ibuprofen. An increased lung permeability phase was noted with intravenous endotoxin but not with tissue endotoxin. As expected, this phase was not inhibited with ibuprofen and, therefore, not prostanoid-induced.
The lung is very susceptible to sepsis or endotoxin injury in the trauma patient. We studied the effect of an episode of hemorrhagic shock and resuscitation on the prostaglandin-induced pulmonary ...hypertension and leukocyte-induced increased permeability phase of endotoxin lung injury. Eight unanesthetized sheep with chronic lung lymph fistula were bled 50% of blood volume for 2 hr, then resuscitated. Thromboxane, TxA2, levels increased from 0.1 to 0.6 ng/ml during shock, while blood white cell count decreased. Both parameters returned to baseline while lung lymph flow increased twofold during resuscitation with lymph being protein-poor, indicating no increase in permeability. Lung water was not increased but some pulmonary leukostasis was evident histologically after resuscitation. We then studied the effect of this process on all immediate endotoxin insult. Seven unanesthetized sheep were given 0.7 microgram/kg E. coli endotoxin alone, and again after shock and resuscitation, in paired studies performed 3 days apart. There was no difference in either the early pulmonary hypertension or the later increased permeability phase of endotoxin lung injury when comparing the paired studies, as measured by lymph flow and protein flux. Hemorrhagic shock, despite producing a transient increase in thromboxane and pulmonary leukocyte sequestration, does not accentuate the lung injury of endotoxin if the shock state is adequately resuscitated.
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