The pathogenesis of the low pleural fluid pH in esophageal rupture.

To determine the possible mechanisms responsible for the low pH pleural effusion associated with esophageal rupture we evaluated the following possibilities: (1) gastric acid reflux, (2) bacterial metabolism, and (3) leukocyte metabolism. Neither elimination of gastric hydrogen ion contribution by distal esophageal ligation nor elimination of bacteria with antibiotics prevented the progressive fall in pleural fluid pH after esophageal rupture. Only elimination of polymorphonuclear leukocytes from the pleural space by rendering animals leukopenic with nitrogen mustard, prevented a low pH effusion after esophageal rupture. It appears that pleural fluid leukocyte metabolism is primarily responsible for the low pH effusion associated with esophageal rupture.

Rheumatoid pleurisy. observations on the development of low pleural fluid pH and glucose level.

A patient with rheumatoid pleurisy provided the opportunity to observe the time course of development of the low glucose level and low pH characteristic of these pleural effusions. During six days, the effusion evolved from one with a normal glucose value and pH to one with a glucose value of 20 mg/dL and a pH of 6.78. The mechanisms responsible for these phenomena probably are (1) a selective block to glucose transport from blood to pleural fluid, (2) enhanced glucose use by rheumatoid pleura, and (3) an efflux block to the end products of pleural space glucose metabolism. Once the low glucose value-low pH rheumatoid effusion develops, it seems not to revert to an effusion with a normal glucose level and pH.

A model of immune complex-mediated pleuropulmonary injury; evidence of deposition of circulating immune complexes in the lung.

Severe acute, diffuse lung inflammation was induced in rabbits immunized to bovine serum albumin (BSA) and subsequently challenged with BSA intrapleurally. Evidence suggesting involvement of circulating immune complexes in the pathogenesis of lung injury in these rabbits include 1) positive lung immunofluorescence, 2) a fall in serum hemolytic complement, 3) diffuse bilateral involvement despite unilateral antigen challenge, and 4) absence of these findings in control rabbits. Further investigation with this model may provide insight into the processes involved in the deposition of immune complexes in the lung and the mechanisms of lung injury provoked by immune complex deposition.

The diagnostic value of pleural fluid pH.

One hundred eighty-three patients had simultaneous blood and pleural fluid pH determinations. Thirty-six effusions were transudates, and 147 were exudates. In 46 effusions, the pleural fluid pH was less than 7.30; all 46 were exudates. A pleural fluid pH less than 7.30 was associated with the following six diagnoses: (1) empyema; (2) malignancy; (3) collagen vascular disease; (4) tuberculosis; (5) esophageal rupture; and (6) hemothorax. The results of pleural fluid pH determination are immediately available, narrow the differential diagnosis of the exudate, and may expedite patient management. The pH of pleural fluid should be measured whenever a diagnostic thoracocentesis is performed.

Exercise-induced anaphylactic reaction to shellfish.

The syndrome of immediate type I food hypersensitivity, mediated by tissue-bound IgE antibody and mast cell histamine release, is well recorded in the medical literature. This case study represents a previously undescribed late food hypersensitivity, induced only by strenuous exercise. Identification of this new syndrome illustrates classical epidemiologic analysis, improves medical advice for the allergic and athletically inclined, and raises new questions in the areas of allergy and immunology.

Pulmonary lymphangitic carcinomatosis from the cervix. Diagnosis by transbronchial biopsy.

A diagnosis of pulmonary lymphangitic spread of cervical cancer was established by transbronchial biopsy in a 58-year-old woman requiring mechanical ventilation. Confirmation of the clinical diagnosis allowed supportive therapy in this terminal stage of cancer. To our knowledge, this report is the first to describe this result from cervical carcinoma and to establish the diagnosis of lymphangitic carcinomatosis by transbronchial biopsy.

A measles outbreak in a New England community. Perspectives.

Between May 30 and June 29, 1974, 28 cases of measles occurred in schoolchildren in a residential New England community. The index patient probably contracted the disease on a school field trip 11 days before the onset of her illness. Of the other 27 cases, 15 had received live measles vaccine before age 1, and ten had no history of vaccination or disease. Four documented vaccine failures did occur in children vaccinated after age 1, but this was not an unusual number compared with the total number of vaccinees evaluated during the investigation. Control measures for susceptible persons including vaccination or modifying doses of immune serum globulin for exposure occurring more than 24 hours earlier. No additional cases of measles were reported for one month after the epidemic.

Hepatitis type A in an oral surgeon: a prospective study of contacts.

No acute cases of clinical or anicteric hepatitis were in observed in 75% of 161 patients who had been exposed to hepatitis A by an oral surgeon during the contagious period. Three cases of liver dysfunction of indeterminate cause did occur, although at least two could be attributed to multiple abuses of drugs 3-5 and not to exposure to hepatitis. The fact that hepatitis A did not spread in this instance suggests that oral surgeons who are ill with acute hepatitis A do not necessarily transmit the disease to their patients. Epidemiologic investigations of similar situations will undoubtedly augment this preliminary data.

Inhibition of digoxin absorption by neomycin.

The effect of the administration of the antibiotic neomycin sulfate on the absorption of digoxin was assessed in crossover studies in normal human volunteers. Doses of neomycin (1 and 3 g) markedly depressed serum digoxin concentrations, the areas under the serum concentration-time curves, and cumulative 6-day urinary digoxin excretion after the oral ingestion of 0.5 mg of the cardiac glycoside in tablet form. Neomycin also prolonged the mean time at which peak serum digoxin levels were attained by 1.7 to 3 hr. The inhibition of digoxin absorption was also seen: (1) when the antibiotic was given 3 or 6 hr before the cardiac glycoside, (2) with digoxin tablets of varying dissolution rate, (3) when digoxin or neomycin solutions were used instead of tablets, and (4) in a patient who had had a total gastrectomy. When neomycin was administered with maintenance doses of digoxin, steady state serum digoxin concentrations were significantly reduced. When neomycin was given after a 9-day period of digitalization, the terminal serum digoxin half-life was not significantly shortened. Single doses of neomycin did not interfere with the extent of absorption of d-xylose. In vitro, neomycin did not affect the movement of digoxin across dialysis membranes, nor did it precipitate digoxin out of human bile or intestinal fluid. Neomycin thus clearly depresses the rate and extent of digoxin absorption in man. The mechanism of this effect remains to be established.

Transfusion malaria as a consequence of the 1974 war between Turkey and Greece--two cases.

Two cases of transfusion induced Plasmodium malariae malaria that occurred in August and September 1974 in New York City were direct results of the outbreak of war between Turkey and Greece on the island of Cyprus in July 1974. The cases could be traced to two Greek immigrants with latent infection (one being the longest ever recorded) who independently donated blood after solicitation for people in need living in the country of their ancestors. In view of current rules for donor acceptability, attention should be directed domestically towards careful surveillance for an increased occurrence of transfusion malaria.