John P. Manos

Depression of immunologic surveillance by pump-oxygenation perfusion

Abstract A depression in serum bactericidal capacity and immunoprotein factors (complement and immunoglobulins) essential to the integrity of host surveillance mechanisms has been demonstrated in patients who have had corrective cardiac surgery employing standard nonmembrane pump oxygenation. It is inferred that these adverse effects on protein and possibly cellular factors in the blood are attributable to cardiopulmonary bypass, and are mediated in part through the interface protein denaturation that occurs in the blood oxygenator. Although a causal relationship has not been established definitely, there is evidence to suggest that cardiopulmonary bypass produces changes that underlie the diverse pathophysiologic states, including susceptibility to infection, abnormal bleeding, and deranged organ function, which contribute so significantly to the morbidity and mortality of open heart surgery.

Is the sutureless cataract incision a valve for bacterial inoculation

Abstract Many cataract surgeons perform sutureless surgery to decrease operating time, postoperative astigmatism, and healing time. Anecdotal case reports of postoperative endophthalmitis after sutureless surgery prompted our investigation of this type of wound closure and its possible relationship to an increased incidence of infection. This in vitro study addressed the question: Is sutureless more likely than sutured cataract surgery to provide a route for inoculation of microbial organisms into the eye? Twenty‐eight human eyes obtained postmortem were randomly divided into 14 pairs and successively incubated for 90, 150, 210, and 270 minutes each in a suspension of Staphylococcus epidermidis in physiologic media. Cultured aqueous aspirates yielded no significant differences between sutured and unsutured eyes in colony counts at any time interval. This suggests that both sutured and unsutured wounds resist bacterial ingrowth equally and that a properly constructed unsutured wound is not a significant valve for bacterial inoculation in an eye pressurized to physiological conditions.

Identification of gram-negative bacilli using the Autobac IDX.

The Autobac IDX is a new system for the rapid identification of clinically significant members of the Enterobacteriaceae and Aeromonas, Acinetobacter, Alcaligenes, Flavobacterium, Moraxella, and Pseudomonas species. The use of 18 differentially inhibitory compounds such as dyes and antibiotics along with a computerized algorithm based on a multivariate analysis provides the basis for the identification of 30 different groups of gram-negative bacilli. Required preliminary tests include observations on the presence or absence of swarming on a sheep blood agar plate and noting the following: growth, lactose fermentation, and bile precipitation from a MacConkey plate. Spot indole and spot oxidase tests must be performed as well. Identification by the Autobac IDX System takes 3-6 hr after completion of the preliminary tests. From a total of 403 isolates tested, the Autobac system agreed with the MicroID AND N/F systems on 382 identifications (94.8%). Four isolates, two Acinetobacter anitratus, one Serratia marcescens and one Moraxella osloensis could not be identified by IDX. Additional testing was required on 35 (8.7%) of the isolates.

RAPID REMOVAL OF TISSUE CULTURE MONOLAYERS BY COLLODION FOR SUBSEQUENT STAINING.

Removing cultures from roller tubes before staining eliminates the destaining which often occurs when the cells are first stained and then removed by embedding in collodion. The cells are fixed in situ, dehydrated, and covered with collodion (Merks flexible) for 10 min. The collodion is poured off, the fluid residue lining the tube allowed to dry for 10 min, and the tube is filled with tap water. The collodion cast containing the cells is loosened and removed, cut into strips, placed on slides and blotted into firm contact. The collodion is then dehydrated and dissolved with absolute alcohol followed by a 1:1 mixture of alcohol and ether. The slides can then be rehydrated and stained by conventional methods.

Direct susceptibility testing on positive blood cultures using Autobac I

Abstract Direct susceptibility tests on 243 on positive blood cultures were performed using a rapid Autobac I procedure and the standard Autobac I procedure. After examining 1762 disc comparisons there was an overall agreement between the two techniques of 95%. A total of 1.5% very major, 1.4% major and 1.8% minor discrepancies occured.