Biomedical subjects
Publications and source records attributed to K R Ratzan.
Bacterial endocarditis due to Lactococcus garvieae is extremely unusual, and may actually be underreported due to its morphologic and biochemical similarities with enterococci. Only three cases have been reported in the medical literature, and all involved prosthetic valves. We report a case of native valve bacterial endocarditis caused by L. garvieae.
Explore the source record for details and available documents.
Sepsis due to Pseudomonas aeruginosa continues to be an important source of morbidity and mortality in hospitalized patients. Early recognition of this condition is of paramount importance in choosing specific therapy at the earliest possible moment. We present three cases in which P aeruginosa bacteremia was manifested by subcutaneous nodules. Although such lesions have been reported before, we place new emphasis on the uniqueness of this lesion to P aeruginosa, the feasibility of visualizing the organism and culturing it from biopsies of the lesions, and the possibility of choosing appropriate therapy early through recognition.
A 20-year-old woman developed severe shortness of breath 4 h after a cesarean section. Chest roentgenogram showed a pleural effusion and tension pneumothorax; insertion of a chest tube drained liquid stool. At surgery she was found to have a left diaphragmatic defect with herniation, strangulation, and perforation of the transverse colon into the pleural cavity.
We have reported a case of chronic osteomyelitis due to an unusual anaerobic organism, Clostridium clostridiiforme, a gram-positive rod that often stains gram-negative and that is frequently resistant to such drugs as cefoxitin and clindamycin. Clostridia other than those similar to C perfringens are generally not considered invasive pathogens, but our case and several similar ones show that they can be.
We have reported the case of a 54-year-old man with recurrent painful migratory subcutaneous nodules associated with marked blood eosinophilia and an eosinophilic pleural effusion. The entire syndrome was subsequently determined to be due to cutaneous myiasis caused by the larvae of Hypoderma lineatum, the cattle botfly. Infestation by this or other dipterous fly larvae should be among the parasitic diseases considered in the differential diagnosis of any patient with similar symptoms.
Neisseria flavescens is a rare cause of human disease. This is the first reported case of endocarditis caused by N. flavescens. The organism produced beta-lactamase, and penicillin therapy failed to cure the infection. Therapy with cefotaxime, to which the organism was highly sensitive, led to a complete and uneventful recovery.
Viral meningitis is part of the aseptic meningitis syndrome but must be distinguished from bacterial meningitis on the basis of a careful examination of the CSF and sound clinical judgment. Enteroviruses probably account for the bulk of cases of aseptic meningitis that occur in the United States and which are reported to the Centers for Disease Control each year. The seasonal pattern in the incidence of aseptic meningitis is largely due to the seasonal variation of enteroviral infections. Early on, the CSF in patients with viral meningitis frequently contains a predominance of polymorphonuclear leukocytes and may even have a low glucose level. The presence of neutrophils in the initial CSF sample is especially common in patients with enteroviral infections. A CSF glucose level lower than 50 per cent of a simultaneously drawn blood glucose determination is not uncommon in patients with viral meningitis due to mumps, LCM, and herpes simplex. In a patient with a predominance of polymorphonuclear leukocytes in the initial CSF specimen and in whom a viral infection is suspected, antibiotics may be withheld if a spinal tap is repeated within 12 hours. A shift from polymorphonuclear leukocytes to mononuclear cells makes viral meningitis the likely diagnosis. Both herpes simplex and varicella-zoster may infect the meninges by means of spread from cervical and dorsal root ganglia in a retrograde fashion much the way they spread in an antegrade fashion to the skin. HSV-2 is more likely to cause the clinical syndrome of viral meningitis, while HSV-1 is more likely to cause a meningoencephalitis with serious brain dysfunction. The identification of a specific viral agent in body fluids, especially the CSF, in a patient with aseptic meningitis is of more than academic interest, since it can shorten duration of hospital stay and eliminate unnecessary antimicrobial therapy. The diagnosis of enteroviral infections depends upon the isolation of a virus from CSF, stool, or throat plus a fourfold antibody response in the serum to the viral isolate. The 60-odd serotypes of enterovirus, each with different antigenic determinants, preclude serologic testing alone as a useful diagnostic test to identify the patient infected with coxsackievirus or echovirus. For infections, due to herpes simplex, varicella-zoster, LCM, and arboviruses, a serologic test alone can be useful.(ABSTRACT TRUNCATED AT 400 WORDS)
Forty-eight patients who underwent elective hip or knee surgery were randomly divided into two groups. A total of 22 patients received a single 1-g preoperative bolus of cefoxitin, and 26 patients received a single 1-g preoperative dose of cephalothin. At various time intervals, serum and bone samples were taken during the operative procedure. Our data indicated that whereas serum levels of cefoxitin and cephalothin were maintained for at least 2h at levels capable of inhibiting most gram-positive cocci and many gram-negative rods, bone levels of cefoxitin rather rapid decay over a 2-h period. Moreover, in only 58% of the entire cephalothin-treated group were bone levels detectable and then only at a concentration that would inhibited gram-positive cocci. No significant morbidity was observed in either treatment group.
The biliary tract excretion of cefamandole, cefazolin, and cephalothin was measured in eight patients with T-tubes inserted into their common ducts after ductal exploration for biliary tract stones. Each patient received 1.0 g intravenously of each cephalosporin on 3 separate days; T-tube bile and serum were collected at selected time intervals thereafter. In seven patients, bile and urine were collected for 6 h after the administration of each drug. Mean peak levels of cefamandole, cefazolin, and cephalothin in bile were 352, 46, and 12 mug/ml, respectively. The respective mean peak serum levels were 55.0, 92.8, and 32.4 mug/ml. Despite the fact that peak serum levels of cefazolin were 1.5 times those of cefamandole, levels in bile of cefamandole were about 8 times those of cefazolin. Over a 6-h period, almost three times as much cefamandole was excreted into bile as was cefazolin. Therefore, in those patients with biliary tract sepsis, in whom a cephalosporin is indicated for therapy, cefamandole appears to be the drug of choice.
Sodium cyanate, a drug that prevents sickling of hemoglobin S by virtue of its irreversible carbamylation of the N-terminal amino group of valine, was studied for its effect upon the function of normal human polymorphonuclear luekocytes. In concentrations of 500 and 100 mug/ml, sodium cyanate was found to inhibit killing by neutrophils of Staphylococcus epidermidis and Eschierichia coli but not of Streptococcus faecalis. Viability of cells and phagocytosis were not affected by cyanate; however, production of [14-C] carbon dioxide from [1-14-C] glucose and the iodination of 125-I during phagocytosis were significantly impaired. Cyanate is thought to inbibit the bacterixidal activity of neutrophils by interfering with the oxidative metabolism of gluxose via the hexose monophosphate shunt (theraby decreasing production of H-2-O-2) and by inbibiting iodination of ingested bacteria (either by competing with iodide as the oxidizable cofactor or by inhibiting myeloperoxidase). Since these effects of cyanate were all reversible by washing the nurtrophils free of the drug, it is unlikely that they are due to amino carbamylation.
A patient had bilateral deep brachial vein thrombophlebitis in which Vibrio fetus was recovered from six blood cultures of the six drawn. Fever and phlebitis continued with treatment with intravenous doses of heparin and oxacillin but rapidly improved with treatment change of oxacillin to clindamycin. In vitro antibiotic disk susceptibility testing confirmed resistance to oxacillin and susceptibility to clindamycin. Vibrio fetus infection is associated with the vascular endothelium in this and previously reported cases
The biliary tract excretion of three cephalosporins, cefazolin, cephaloridine, and cephalothin, was compared in patients with biliary tract disease. In the absence of obstruction, mean antibiotic levels in bile from gall bladder and common duct in patients undergoing cholecystectomy were highest for cefazolin (17 and 31 mug/ml, respectively) than either cephaloridine (7 and 9 mug/ml) or cephalothin (1 and 4 mug/ml). Biliary tract levels generally paralleled serum levels. In no patient with cystic duct obstruction were any of the cephalosporins detectable in appreciable amounts in gall bladder bile. In patients with T-tube drainage given each of the three different cephalosporins on separate days, concentrations of cefazolin in bile were many-fold higher than either cephaloridine or cephalothin. Peak levels of cefazolin in T-tube bile averaged 51 mug/ml after intravenous and 26 mug/ml after intramuscular administration, whereas mean peak levels of cephalothin and cephaloridine were only 6 and 16 mug/ml, respectively. Here, too, T-tube levels reflected serum concentrations and obstruction to biliary flow impaired excretion of each of the drugs.
Explore the source record for details and available documents.
Macrophages from mice infected with facultative intracellular organisms such as Listeria monocytogenes and BCG have been shown to resist infection by antigenically unrelated intracellular bacterial parasites. This study compares phagocytosis, bacterial growth inhibition, and oxidation of glucose by macrophages from normal mice, mice infected with listeria or BCG, or mice immunized with killed listeria in incomplete Freund's adjuvant. Macrophages from listeria- and BCG-infected mice ingested more listeria; 67 and 57%, respectively, had three or more cell-associated bacteria versus 22% of controls (P < 0.001). Peritoneal macrophages from listeria- and BCG-infected animals significantly (P < 0.001 covariance analysis) inhibited growth of listeria in suspension, whereas control macrophages had no such inhibitory effect. The rate of oxidation of glucose-1-(14)C was higher in macrophages from listeria- and BCG-infected mice than from either uninfected animals or those immunized with killed listeria. During phagocytosis of killed or live bacteria, or latex particles, the rate of glucose oxidation was increased (P < 0.01). These data suggest that the cellular immunity after infection by an intracellular organism is associated with an increase in metabolic activity of macrophages, namely, an increase in the rate of glucose oxidation resulting in enhancement of phagocytosis and killing.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.