Acute hemiplegia associated with HIV infection.

An acute hemiplegia secondary to a large cerebral infarct is described in a 16-month-old infant with congenitally-acquired human immunodeficiency virus infection. Serial imaging studies during the next year documented improvement in his hemiplegia and a static underlying human immunodeficiency virus encephalopathy. Acquired immunodeficiency syndrome should be included in the differential diagnosis of children with acute hemiplegia.

Reaction of fungal products with amebocyte lysates of the Japanese horseshoe crab, Tachypleus tridentatus.

A commercially available endotoxin assay (CS-TAL) employing a chromogenic peptide and an amebocyte lysate from the Japanese horseshoe crab, Tachypleus tridentatus, gave a positive result with aqueous extracts of all 15 strains of Candida albicans and 1 strain each of Candida tropicalis, Cryptococcus neoformans, and a Mucor species that we tested. Purified glucans prepared from the Candida strains gave the same results. Reconstruction experiments showed that the positive results were not due to contaminating endotoxin. By contrast, assays employing amebocyte lysates of the American horseshoe crab, Limulus polyphemus, were inconsistent. Japanese workers have presented evidence that glucans activate the Tachypleus amebocyte lysate system by acting on an enzyme different from that on which endotoxin acts. Using a Tachypleus lysate preparation (Endospecy; Seikagaku Kogyo, Tokyo, Japan) from which this enzyme was excluded, we demonstrated a 5- to 10-fold drop in reactivity to the aqueous Candida extracts and glucans, whereas reactivity to endotoxin was unchanged. Normal human plasma was shown to decrease the effect of fungal extracts on CS-TAL. This inhibition was completely removed by heating the plasma. Our results suggest that Tachypleus systems may be of use clinically in distinguishing bacterial from fungal infections.

Endotoxin levels in immunocompromised children with fever.

Febrile episodes for which no cause can be found are common in immunocompromised children. We postulated that circulating endotoxin, a known pyrogen, might be responsible for some of these episodes in the absence of documented infection. Plasma endotoxin levels were assayed using a recently developed Limulus amebocyte lysate assay enhanced in sensitivity and objectivity by the addition of a chromogenic substrate. Eighty-seven plasma endotoxin determinations were made in 36 immunocompromised children with fever. Convalescent endotoxin levels and levels in normal children were also obtained. It was concluded that a plasma endotoxin level of 35 pg (0.10 EU)/ml constitutes the upper limit of normal in children. Five children (14%) had elevated endotoxin levels in the course of the febrile episodes, in the absence of bacteremia or clinically diagnosed infection. In each case, the levels returned to normal during convalescence. It is concluded that endotoxemia is a possible cause or contributing cause of unexplained fever in immunocompromised children.

Demonstration of differences between strains of Staphylococcus aureus by peptidoglycan fingerprinting.

Lysis of peptidoglycans of Staphylococcus aureus yields products that exhibit strain-specific patterns on analysis by thin-layer chromatography and polyacrylamide gel electrophoresis. The patterns are demonstrated when products of the endogenous autolysins are examined and are enhanced and/or altered by the use of exogenous murolytic enzymes. These fingerprinting techniques were applied to the study of 55 strains of S. aureus. Twenty-six strains were from patients in five localized hospital outbreaks, and 29 were obtained randomly from individual patients. With only two exceptions all strains from a given outbreak had an identical murolytic pattern, whereas the random strains showed variable patterns. Peptidoglycan fingerprinting may be an adjunct tool for the hospital epidemiologist and may also be valuable for the study of certain biologic aspects of interstrain differences.

Quantitative blood cultures in the evaluation of septicemia in children with Broviac catheters.

We applied quantitative methods of analysis to all blood cultures drawn during the course of treatment in 28 children with Broviac catheters in a central vein. Thirty febrile episodes in 14 of these patients were evaluated. Samples of blood obtained from a peripheral vein and through the central catheter were cultured quantitatively on agar plates and nonquantitatively in standard broth media. Catheters were judged to be a source of septicemia nine times in seven children. In all nine positive catheter samples, the concentration of pathogens was 10 times as great as that observed in the peripheral venous sample. The blood drawn through the Broviac catheter contained greater than or equal to 2000 colony-forming units per milliliter in six cases. Quantitative cultures in two patients with septicemia not attributable to the catheter yielded low colony counts in the catheter sample. Cultures of blood samples drawn through the catheter when a child was well were not helpful in predicting subsequent septicemia. The technique of inoculating blood directly onto agar plates is easily performed and superior to standard broth cultures, because it detected pathogens within 16 hours and identified infections with multiple organisms.

A double-blind controlled trial of anti-Pseudomonas chemotherapy of acute respiratory exacerbations in patients with cystic fibrosis.

A double-blind controlled trail of anti-Pseudomonas chemotherapy was carried out in 24 exacerbations of pulmonary disease in patients with cystic fibrosis. Fifteen exacerbations were treated with oxacillin plus sisomicin and carbenicillin (treatment group); nine were treated with oxacillin alone (control group). The planned length of treatment was 14 days. The difference between the failure rate in the treatment group (3/15) and the control group (7/9) was statistically significant (P less than 0.015). The difference in improvement of forced expiratory volume in 1 second was also significant (P less than 0.025). At the end of the study, Pseudomonas aeruginosa was still present in the sputum of all nine patients in the control group, but was not isolated from six of the 15 patients in the treatment group. The data suggest a beneficial role for anti-Pseudomonas chemotherapy in the treatment of acute pulmonary exacerbations in patients with cystic fibrosis.