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Biomedical subjects

D C Hohn

Publications and source records attributed to D C Hohn.

8 recordsLinked to original sources
PubMed1977

Antimicrobial systems of the surgical wound. I. A comparison of oxidative metabolism and microbicidal capacity of phagocytes from wounds and from peripheral blood.

Oxygen consumption glucose oxidation via the hexose monophosphate shunt, and superoxide production by resting and stimulated leukocytes derived from rabbit blood and from experimental rabbit wounds five to seventeen days old were measured and compared. In vitro killing of staphylococci by blood and wound leukocytes was also measured. In all of these studies there were no significant functional differences between blood and wound cells. The data presented suggest that under the same in vitro conditions, blood and wound leukocytes are functionally equivalent, that tissue mobilization does not cause alteration of wound leukocytes, and that aging of the wound does not impair the microbicidal capacity of wound leukocytes.

Animals↗
PubMed1977

Antimicrobial systems of the surgical wound. II. Detection of antimicrobial protein in cell-free wound fluid.

Human wound fluid contains heat-stable proteins with moderate antibacterial activity against Staphylococcus aureus and Escherichia coli, and different heat-labile proteins with antibacterial activity against E coli. Blood serum also contains heat-labile antibacterial substances, but little heat-stable activity against Staphylococcus aureus. Both blood serum and wound fluid have bacteriostatic activity against S epidermidis, and early growth of Streptococcus fecalis occurs in serum and wound fluids. The concentration or activity of antimicrobial proteins increases during the first week in the fresh wound and then decreases as the wound matures.

Blood Bactericidal Activity↗
PubMed1977

Leukocyte phagocytic function and dysfunction.

Although some species of bacteria are killed in vitro by humoral factors in cell-free serum, the in vivo experience with leukopenic patients illustrates the critical role played by phagocytic leukocytes in host resistance to infection. Effective ingestion and killing of micro-organisms requires the sequential and integrated function of the elements of the phagocytic system. Each step in the phagocytic process is also a potential crack in the armor of host defense, and an increasing number of clinically significant disorders of phagocytic function are being recognized and described (5). The phagocytic leukocytes are equipped with a variety of intracellular microbicidal mechanisms which provide a degree of overkill capacity and allow these cells to meet the challenges posed by the many and varied microbial transfressors. Undoubtedly, other phagocytic disorders will be discovered and other important aspects of the intraleukocyte killing mechanisms will be elucidated. For instance, little is known about the function of leukocytes within the relatively hypoxic environment of injured tissue where so many bacterial infections begin. As our understanding of phagocytic function develops, new ways may be found to augment host resistance by preservation or stimulation of the phagocytes.

Animals↗
PubMed1975

NADPH oxidase deficiency in X-linked chronic granulomatous disease.

We measured the cyanide-insensitive pyridine nucleotide oxidase activity of fractionated resting and phagocytic neutrophils from 11 normal donors, 1 patient with hereditary deficiency of myeloperoxidase, and 7 patients with X-linked chronic granulomatous disease (CGD). When measured under optimal conditions (at pH 5.5 and in the presence of 0.5 mM Mn++), NADPH oxidase activity increased fourfold with phagocytosis and was six-fold higher than with NADH. Phagocytic neutrophils from patients with CGD were markedly deficient in NADPH oxidase activity.

Adolescent↗