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Biomedical subjects

W Lippert

Publications and source records attributed to W Lippert.

At least 19 recordsLinked to original sources
PubMed1989

Polymorphonuclear leucocyte motility in patients with severe burns.

Chemotaxis, chemokinesis and cellular orientation were measured for unstimulated and 10(-7) n-formyl methionyl leucyl phenylalanine (F-met-leu-phe) stimulated polymorphonuclear leucocytes (PMNS) of nine patients with recent 10-80 per cent burns using a computer-assisted image analysis technique. The technique records PMN movement, as viewed with a phase-contrast microscope on videotapes, and then uses computer programs to calculate the speed and direction of up to 50 PMNS over a 5-min period. Orientation was determined visually. Cellular adherence was also measured by attachment methods. PMNS from burn patients were slower (av. speed 16.8 microns/min), responded less well to F-met-leu-phe (av. speed 20.9 microns/min, av. McCutcheon index 0.32), were less often oriented towards the chemoattractant (av. 39 per cent) and were more adherent (av. 50 per cent) than control cells (av. speed 21.8 microns/min; av. speed F-met-leu-phe 32.2 microns/min; McCutcheon index 0.61; oriented 59 per cent adherent; 16 per cent). Thus PMNS from burn patients orient less well, are significantly slower and have less directionality in response to a chemoattractant, and are more adherent suggesting activation.

Adolescent↗
PubMed1987

A computer-assisted image-analysis system for analyzing polymorphonuclear leukocyte chemotaxis in patients with diabetes mellitus.

A computer-assisted image-analysis system that precisely tracks the cell movements of up to 50 polymorphonuclear leukocytes (PMNLs) was developed and used to quantitatively measure cellular chemokinesis and chemotaxis in normal individuals and in diabetic patients with hyperglycemia. The PMNLs were tested in Zigmond chambers with or without a gradient of 10(-7) M n-formylmethionylleucylphenylalanine (f-Met-Leu-Phe). Cellular movement was recorded on videotape by using a videocamera mounted on the microscope. The videotapes were analyzed by computer programs to calculate the speed and direction of each PMNL at 10-sec intervals. Average rates of chemokinesis were 19.6 microns/min without and 25.3 microns/min with f-Met-Leu-Phe. McCutcheon indices, which measure chemotaxis, were 0.01 without and 0.48 with f-Met-Leu-Phe. Similar values were observed in diabetic patients after fasting (average glucose, 217 mg/100 ml) and 2 hr after glucose challenge (average glucose, 309 mg/100 ml). These values demonstrate that PMNLs from diabetic patients with hyperglycemia move at normal rates and respond appropriately to f-Met-Leu-Phe.

Adolescent↗
PubMed1986

A quantitative method for the analysis of cell shape and locomotion.

A rapid, semiautomated system to quantitate and analyze leukocyte shape and locomotion was developed. Video images of moving leukocytes were obtained using a Vidicon camera mounted on a Nikon phase microscope. The video signal was either inputted directly, or indirectly via a video cassette recorder, to a Datacube video analog-digital, digital-analog converter. A Digital Equipment Corporation LSI 11/23 computer using the RT-11/TSX-Plus operating system and computer programs written in FORTRAN and MARCO assembly language permitted image segmentation, image display, and calculation of position, speed, direction of movement and orientation of each leukocyte at 10 s intervals. These data were stored on a winchester disk for subsequent evaluation of the leukocyte orientation, speed and direction of movement using statistical and graphical methods. The reproducibility of measurements made with the video system was tested by comparison with manual measurements; a correlation coefficient of 0.998 was obtained for the two methods. Rates of chemokinesis were then determined for unstimulated and chemokinetically stimulated polymorphonuclear leukocytes (PMNs) and found to average 12.8 micron/min and 18.1 micron/min, respectively. The high speed, ease of data analysis, and potential for multiparameter evaluation makes this system useful for directly evaluating leukocyte locomotion.

Cell Movement↗
PubMed1985

Cellular acid phosphatase activity: correlation of cytochemical and biochemical measurements.

Methods for comparing results of cellular acid phosphatase activities obtained by quantitative cytospectrophotometry with those obtained by biochemical analysis are needed to express the cytospectrophotometric data in biochemical units. Since naturally occurring cells have differing amounts of acid phosphatase, enzyme activity was measured cytochemically and biochemically in polymorphonuclear leukocytes and peritoneal and alveolar macrophages from male rats to determine if these measurements permitted construction of a line correlating the two parameters. Cellular acid phosphatase activity, as measured cytospectrophotometrically and biochemically, increased proportionately with polymorphonuclear leukocytes having the lowest activities and alveolar macrophages the highest. These values when subjected to linear regression analysis fixed a line with a correlation coefficient of 0.95 demonstrating that cytochemical and biochemical activities of acid phosphatase activity can be correlated using naturally occurring cells.

Acid Phosphatase↗
PubMed1982

Group B streptococcal lung infection in neonatal rabbits.

The interaction of alveolar macrophages (AMs) and group B streptococci (GBS) was investigated in 1 and 2-day-old rabbits following infection in an exposure chamber containing 10(7) streptococci per cubic foot of air. The % of streptococci within AMs was similar at 0 and 4 h (36 and 65%) after infection for the two groups of rabbits. Twenty-four h after infection, the 2-day-old rabbits had a significantly higher % of ingested GBS (86 versus 68%). Sixty % of inspired GBS were inactivated by the older rabbits within 4 h after infection. This clearance persisted in the younger rabbits until 48 h (mean negative clearance of -17, -276, and -79% at 4, 24, and 48 h) before their numbers were reduced by inflammation. Sixty of 78 1-day-old rabbits had inflammatory responses between 24 and 72 h versus only 5 of 50 older rabbits. At 24 h after infection, AMs of 1-day-old rabbits contained significantly increased numbers of intracellular GBS microcolonies (17/20) than did AMs from 2-day-old rabbits (5/19). These observations suggest that the enhanced susceptibility to GBS infection in the immediate postnatal period is caused at least in part by ineffective intracellular killing by AMs.

Age Factors↗
PubMed1978

Effect of ozone on lysosomal enzymes of alveolar macrophages engaged in phagocytosis and killing of inhaled Staphylococcus aureus.

The role of lysosomal enzymes in the inactivation of inhaled bacteria by alveolar macrophages was studied in rats infected with aerosols of Staphylococcus aureus and then exposed for 5 hr to 2.5 ppm of ozone to determine whether pollutant-induced defects in phagocytic killing were associated with reduction in enzyme activity. Rates of bacterial ingestion and the activities of cellular acid phosphatase and beta-glucuronidase were measured simultaneously in in situ perfused right lungs by sequential staining of frozen sections for enzyme and bacteria. Quantitative measurements of enzyme activity within macrophages without ingested bacteria were made with a computer-controlled cytospectrophotometry system. Exposure to ozone resulted in diminished rates of bacterial clearance and ingestion, large increases in numbers of intra- and extracellular staphylococcal microcolonies, and an absence of enzyme activity for macrophages containing bacterial microcolonies. Enzyme activity was unimpaired in macrophages without ingested bacteria. These results, in which absence of enzyme activity occurred only in macrophages subjected to the dual insults of ozone exposure and ingested bacteria, prove a relationship between impairment in bactericidal capacity and cellular activities of lysosomal enzymes.

Acid Phosphatase↗
PubMed1978

Effect of protein A on the antistaphylococcal defence mechanisms of the murine lung.

The importance of IgG attached to protein A in the initial reaction of inspired Staphylococcus aureus and alveolar macrophages was studied by infecting unimmunized mice with aerosols of S. aureus strains 566 and Wood 46 with high and low protein A content. At 2, 4, and 8 hr after infection, the presence of IgG attached to S. aureus and rates of staphylococcal ingestion and killing by macrophages were determined. IgG was detected by staining of sections of the right lung with fluorescein-labeled goat antibody to mouse IgG. For S. aureus strain 566, 25%--40% of the total number of bacteria, as determined in equivalently sized subjacent sections stained by the Brown and Brenn tissue gram stain, contained attached IgG. A few S. aureus strain Wood 46 were surrounded by dimly fluorescing complexes. Since rates of bacterial ingestion and killing were similar for both strains in this in vivo model of infection, IgG binding to protein A does not affect the bactericidal capacity of alveolar macrophages.

Animals↗
PubMed1978

Lung response to congenitally athymic (nude), heterozygous, and Swiss Webster mice to aerogenic and intranasal infection by Nocardia asteroides.

Congenitally athymic (nude, Nu/Nu), heterozygous (Nu/+), and Swiss Webster mice were exposed to virulent Nocardia asteroides GUH-2 inhaled from aerosols or administered intranasally. Clearance of the bacteria from the lungs was determined at 6 h and 1, 2, 3 and 7 days after infection. N. asteroides aspirated into the lungs from intranasal administration were killed less rapidly and induced more severe pulmonary infections than did comparable numbers of organisms inhaled from aerosols. Bacterial clearance and histological data indicated that nude mice were significantly more susceptible to nocardial infection than were heterozygous littermates or Swiss Webster mice. From these data we conclude that: (i) pulmonary defenses cope less well with intranasally administered N. asteroides than with aerosolized organisms, (ii) alveolar macrophages alone appear not to be an efficient barrier to nocardial infections, and (iii) T cells are important to pulmonary clearance and prevention of dissemination of N. asteroides from the lung.

Animals↗
PubMed1977

Effect of influenza viral infection on the ingestion and killing of bacteria by alveolar macrophages.

In experimental animals, influenza prediposes the lung to superinfection by reducing the antibacterial efficiency of the alveolar macrophage system. Because such defects may represent abnormalities in ingestion or inactivation of inhaled bacteria, these subcomponents of phagocytosis were tested in mice infected 5 days previously with influenza A virus (NWS or WSN). The mice were exposed to aerosols of Staphylococcus epidermidis and then the rates of bacterial inactivation and percentages of intracellularly located staphylococci were measured. Rates of bacterial inactivation were determined for the left lung by pour-plate enumeration methods. The percentage of ingested bacteria was determined in the in situ perfused right lung by histologically determining the intra- or extracellular location of 100 or more staphylococci. Rates of inactivation of S. epidermidis at 4 hours after bacterial challenge were: control, 90.1 per cent; WSN, 73.0 per cent; NWS, 68.6 per cent, P less than 0.01. The percentage of intracellular staphylococci at 4 hours were: control, 90.9 per cent; WSN, 69.9 per cent; and NWS, 73.8 per cent, P less than 0.01. Microcolonies of proliferating staphylococci were also observed within macrophages of mice infected with each strain of influenza. These experiments demonstrated that in this experimental model, influenzal infection impairs the inactivation of inhaled bacteria by retarding the ingestion of bacteria and by allowing bacteria to proliferate within macrophages.

Animals↗
PubMed1977

Neonatal lung defense mechanisms: a study of the alveolar macrophage system in neonatal rabbits.

Abnormal function of the alveolar macrophage system may explain the enhanced susceptibility to pulmonary infection in human neonates. This hypothesis was investigated by infecting 1- to 14-day-old rabbits with aerosols of Staphylococcus aureus and then measuring in situ rates of bacterial ingestion, inactivation, and destruction in the lapine lung. The inhaled staphylococci were killed within the lungs of 1-day-old rabbits at a significantly slower rate than that for 7- and 14-day-old rabbits (P less than 0.05). Much of this decrease was due to diminished rates of bacterial ingestion by alveolar macrophages of younger animals. Staphylococci were also killed and destroyed less rapidly within these macrophages, but these differences could not be tested for significance.

Animals↗
PubMed1976

Murine pulmonary alveolar macrophages: rates of bacterial ingestion, inactivation, and destruction.

The component processes of phagocytosis (ingestion, inactivation, and destruction of bacteria) were studied in mice by histological and microbiological techniques after aerosol infection with Staphylococcus aureus. Rates of bacterial ingestion and inactivation were (respectively): 0 hr, 37.7% and 0; 1 hr, 64.5% and 45.8%; 2 hr, 75.9% and 67.9%; 4 hr, 82.4% and 84.1%; and 8 hr, 90.7% and 94.8%. Bacterial destruction began 2-4 hr after aerosol infection and affected 80% of the bacteria by 8 hr. Comparison of these processes indicated that bacterial ingestion occurred before inactivation and was 76% complete at 2 hr. Inactivation resulted in death of 84% of the bacteria at 4 hr, and 80% of the bacteria were at least partially destroyed by 8 hr. The mechanism of X-irradiation-induced depression of pulmonary bacterial inactivation was studied in syngeneic mice protected from lethal effects of X-irradiation by chest and pelvic shields or by transplantation of 2 times 10(6) bone marrow cells. Impairments in bacterial inactivation resulted from diminished ingestion of bacteria by macrophages.

Aerosols↗
PubMed1974

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.

Aerosols↗