Elliot Goldstein

Pulmonary Alveolar Macrophage DEFENDER AGAINST BACTERIAL INFECTION OF THE LUNG

The rate of ingestion of inhaled bacteria by pulmonary alveolar macrophages is an important determinant of host defense. This parameter was investigated by infecting rats with finely dispersed aerosols bearing Staphylococcus aureus in high concentrations (about 10(s) bacteria/ft(3)/min). These aerosols deposited more than 10(6) bacteria/murine lung. At 0, 2(1/2), and 5 h after infection, bacterial clearance rates were measured in the left lung, and the intracellular or extracellular location of 100 bacteria was determined histologically in the right lung (perfused in situ). The clearance rates at 2(1/2) and 5 h were 44.5% and 76.9%, respectively. The percentages of intracellular bacteria were: 0 h, 54.8%; 2(1/2) h, 87.1%: 5 h, 91.9%. When rats were exposed for 4 h to 2.5 ppm of ozone (O(3)), bacterial clearance did not occur - 15.3%, although 78.7% of the bacteria were intracellular. Clumps of more than 10 bacteria-usually intracellular-were also present. These experiments demonstrate that phagocytic ingestion is an exceedingly rapid process, that in this experimental model the inactivation of inhaled staphylococci results almost entirely from phagocytosis, and that ozone-induced reductions in bacterial clearance are due to severe impairment of intrapulmonary killing mechanisms and minor impairment of bacterial ingestion.

Effect of Nitrogen Dioxide on Pulmonary Bacterial Defense Mechanisms

Effect of nitrogen dioxide on antibacterial activity in vivo was investigated by simultaneously determining physical removal and bactericidal activity rates of murine lung. Mice were exposed to various concentrations of nitrogen dioxide for 17 hours prior to or 4 hours after infection with aerosols of Staphylococcus aureus labeled with radioactive phosphorus (32P). Animals infected and then exposed to levels of nitrogen dioxide above 7.0 ppm showed a progressive decrease in percent pulmonary bactericidal activity which could not be accounted for by physical removal of bacteria. Exposure to levels of nitrogen dioxide of 2.3 ppm or greater for 17 hours prior to staphylococcal infection caused decreases in bactericidal activity. The finding that murine resistance to infection is diminished at exposure levels only slightly above ambient (2.3 ppm) suggests that human populations may incur a similar risk.

Ozone and nitrogen dioxide exposure: murine pulmonary defense mechanisms.

Since ozone and nitrogen dioxide impair pulmonary resistance to infection by inhibiting the function of the alveolar macrophage, we investigated the effect of combinations of these gases to determine if they interacted biologically in a synergetic, indifferent, or antagonistic manner. Mice were exposed to atmospheres of ozone and nitrogen dioxide for 17 hours prior to, or four hours after, infection with aerosols of Staphylococcus aureus labeled with radioactive phosphorus (32P). Animals infected and then exposed to various oxidant combinations manifested bactericidal dysfunction only when the level of one of the pollutants approximated its individual threshold value. Similar results were obtained when mice were exposed to pollutants for 17 hours before infection. Hence, the pulmonary consequence of exposure to ozone and nitrogen dioxide is equivalent to the injury that would be expected from each individual oxidant.

Successful Treatment of Gram-Negative Bacillary Meningitis with Moxalactam

Meningitis caused by enteric gram-negative bacilli is relatively uncommon but is very difficult to treat despite susceptibility in vitro to many antimicrobics. A major problem appears to be poor entry of many drugs into the central nervous system. Moxalactam is an investigational cephalosporin that attains concentrations in the cerebrospinal fluid that are 15% to 30% of contemporaneous serum concentrations; moreover, it is quite active against many of the enteric gram-negative bacilli. We used moxalactam to treat meningitis caused by Enterobacter cloacae, Klebsiella pneumoniae, and Escherichia coli in four adults and one child, giving up to 100 mg/kg body weight per day by intravenous injection. The concentrations of moxalactam in serum, lumbar, and ventricular cerebrospinal fluid exceeded the minimal lethal concentrations of all causative bacteria. The patients were cured. In this small series, moxalactam, when administered intravenously as the sole agent of therapy, was effective in the treatment of meningitis caused by susceptible gram-negative bacilli.

A charge coupled device-based image cytophotometry system for quantitative histochemistry and cytochemistry.

A rapid, semiautomated cytophotometry system for quantitative histochemistry and cytochemistry was constructed. The system consists of a Fairchild charge coupled device (CCD) image camera, a Zeiss Universal microscope, a Datacube analog to digital converter, and a digital Equipment Corporation LSI 11/23 computer operating under RT-11. Computer programs were written in FORTRAN and the MACRO assembly language for the acquisition of data from the CCD device. These data were then used for image segmentation, image display, and calculation of total optical density, perimeter, cell area, and several shape features. The reproducibility of measurement made with the CCD-based cytophotometry system was tested by repeated measurements. The coefficient of variation was estimated to be 1.7% for total optical density and 0.9% for cell area. The CCD-based cytophotometry system was further evaluated by comparing results with measurements made on the same cells with a scanning stage cytophotometer using the HIDACSYS computer programs. Correlation coefficients of 0.96 for total optical density and 0.91 for cell area were obtained between the two systems. We conclude that the high-speed, dimensional stability, small size, and linearity of the CCD-based cytophotometry system will make it useful for quantitative histochemistry and cytochemistry.

Quantitative microscopy: I. A computer-assisted approach to the study of polymorphonuclear leukocyte (PMN) chemotaxis.

A computer‐assisted approach has been designed to analyze and quantitate polymorphonuclear leukocyte (PMN) Chemotaxis. This approach involves a rapid, objective, and semiautomated (user‐directed) image‐analysis system that is video‐ and microscope‐based. The entire system consists of a microvideo set‐up that is put on line with a Digital DEC‐LSI‐11/73 microcomputer, interfaced with a Datacube analog‐digital/digital‐analog converter. Video signals of PMN movement are digitized by the system at a resolution of 240 pixels vertically by 320 pixels horizontally (at 256 gray levels) and stored in a 76,800‐byte frame buffer. The digitized data are stored for later use or utilized immediately for image segmentation, image display, movement, and morphometric computations for each PMN in a maximum phase field (at 645 × high dry) of 50 PMNs at 10‐second intervals. The digitized data are used for computation of cell perimeter, surface area, optical density, contour‐ratio, position, speed, and direction of locomotion with the utilization of micro‐image‐analysis programs written in FORTRAN and MACRO assembly language, with the computer operating under RT‐11/TSX +. The reliability, objectivity, and reproducibility of measurements made with this quantitative approach have been tested by comparing with manual‐tracing measurements of PMN movement. A correlation factor of 0.99 has been obtained. However, the quantitative‐microscopic approach is much faster, more objective, less tedious, and much easier to operate than the conventional manual‐tracing method.

Influence of Ozone on Pulmonary Defense Mechanisms of Silicotic Mice

Respiratory illnesses are consequences of exposure to atmospheric pollutants. Whether or not anatomic damage due to pneumoconiosis increases susceptibility to infection following exposure to pollutants is unknown. Silicosis was induced in mice by intratracheal infection of 10 mg of silica. Seventy days later, silicotic and latex-injected controls were infected with aerosols of Staphylococcus aureus labelled with phosphorus 32, and then exposed for four hours either to ozone (0.4 to 1.6 ppm) or air containing 21% oxygen. Following this, murine pulmonary bactericidal activity rates were determined. An equivalently progressive decrease in pulmonary bactericidal activity occurred with exposure to increasing ozone concentrations for silicotic and control mice. Silicosis, itself, did not inhibit bactericidal activity, since the silicotic and control mice which were exposed to the oxygen had normal bactericidal activity, it is concluded that anatomic abnormalities due to silicosis do not enhance ozone-induced in...

Reactivation of tritonated models of human polymorphonuclear leukocytes (PMNs): a computer-assisted analysis.

The orientation (chemotaxis) and locomotion (chemokinesis) of human polymorphonuclear leukocytes (PMNs) are generated by an internal movement mechanism that involves active cytoplasmic movement; they are influenced by external environmental and ionic conditions. We have studied the degree to which the orientation and movement mechanisms of PMNs are self‐contained within the cell and the degree to which they are under membrane control.

INCREASED LEUKOCYTE ALKALINE PHOSPHATASE IN SICK NEONATES

Alkaline phosphatase (LAP) and myeloperoxidase (MPO) were evaluated in polymorphonuclear leukocytes (PMNs) from neonates using a computer-assisted cytospectrophotometer. This method allowed quantitative enzyme determinations within each PMN. Population distributions were determined for 100 individual cells. Of the 10 infants studied, 8 were ill, 3 with congenital pneumonia and 5 without proven infection, and 2 were well pre-term infants. PMNs were obtained from all during the first week of life and from 5 during the third week, as well. The 8 ill infants showed a broad distribution of LAP activity in their PMNs in the first week of life, with 75.4±25.2% ([xmacr ;[plusmn;S.D.) of PMNs having LAP activity greater than the 95th percentile of our adult controls. By the third week of life, the percent of PMNs had significantly diminished to 35.6±33.9% ([xmacr ;[plusmn;S.D.) (p < .05). The 2 well pre-term infants in the first week of life had only 7±4% ([xmacr ;[plusmn;S.D.) of PMNs with activity greater than the 95th percentile for adult controls. The distribution of MPO activity did not differ from adult controls in any infant.In summary, we found increased PMN LAP activity in the first week of life in sick neonates with and without infection as compared with adults and well neonates. Decreasing LAP activity in the third week of life corresponded with clinical improvement. Thus, differences in intracellular LAP activity appear to be due to pathologic rather than maturational processes.