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Biomedical subjects

C U Tuazon

Publications and source records attributed to C U Tuazon.

At least 73 records · Page 4Linked to original sources
PubMed1982

Evidence for the secretion of soluble peptidoglycans by clinical isolates of Staphylococcus aureus.

Four isolates of Staphylococcus aureus from patients with endocarditis and bacteremia were capable of secreting high-molecular-weight soluble peptidoglycans when grown in a minimal cell wall medium containing penicillin G. Vancomycin was not able to substitute for penicillin G in triggering this secretion. Secretion reflected de novo synthesis of soluble peptidoglycan and was strongly dependent on time of incubation (30 to 60 min), and number of bacteria (2 X 10(8) to 5 X 10(8) colony-forming units per ml), but not on penicillin G concentration (10 to 250 micrograms/ml). The incorporation of alanine into the peptidoglycans secreted in vitro by these isolates incubated in the presence of penicillin G under optimal conditions was variable. The least incorporation of alanine into peptidoglycan occurred with an isolate from a patient treated with nafcillin who had no detectable antipeptidoglycan titer.

Alanine↗
PubMed1982

Teichoic acid antibodies in osteomyelitis and septic arthritis caused by Staphylococcus aureus.

Counterimmunoelectrophoresis and gel-diffusion techniques were used to study the development of teichoic acid antibodies in eighteen patients with osteomyelitis and seven patients with septic arthritis caused by Staphylococcus aureus. Nine of eleven patients with acute osteomyelitis and three of seven with chronic osteomyelitis had a positive response to tests for teichoic acid antibody. However, only two of seven patients with septic arthritis generated a positive teichoic-acid antibody response. In two patients the test was extremely valuable in the diagnosis and management of osteomyelitis. Antibody detection appears to be a sensitive test for detecting staphylococcal osteomyelitis, especially the acute variety. It does not appear to be a reliable test for septic arthritis. It is also useful for the detection of antibody in patients who had received prior antibiotic therapy, yet have persistent foci of infection. The presence of the teichoic acid antibody, as well as its titer, is of diagnostic value in patients with serious infections caused by Staphylococcus aureus. The detection and quantification of teichoic acid antibodies is of great value for the early diagnosis of patients with acute osteomyelitis caused by Staphylococcus aureus and for assessing the clinical response of such patients.

Acute Disease↗
PubMed1981

Clinical efficacy of cefoxitin in the treatment of head and neck infections.

Cefoxitin sodium, a new cephamycin antibiotic, is active against many aerobic and anaerobic bacteria. Four patients with infections of the head and neck (otitis externa with cellulitis, parotiditis, tracheitis, and facial cellulitis), who had failed to respond to initial antibiotic regimens, responded satisfactorily to cefoxitin therapy. No adverse effects were noted in any of these patients. Results of this report suggest cefoxitin is a safe and well-tolerated antibiotic that is efficacious in the treatment of head and neck bacterial infections that are sensitive to this drug.

Adult↗
PubMed1981

Antibody levels to bacterial peptidoglycan in human sera during the time course of endocarditis and bacteremic infections caused by Staphylococcus aureus.

Sera from patients with endocarditis and bacteremia due to Staphylococcus aureus were compared for peptidoglycan-binding capacity with those from normal blood donors. Those patients treated with beta-lactam antibiotics had higher antigen-binding levels than normal donors and patients treated exclusively with vancomycin (P less than 0.01). The factor responsible for this activity was purified by affinity chromatography from a normal donor and shown to be an immunoglobulin. Specificity studies indicated that the immunodominant determinant was a peptide sequence found in peptidoglycan precursors. Since soluble peptidoglycan molecules having the precursor peptide sequence are known to be secreted by some gram-positive bacteria like Micrococcus luteus when grown in the presence of beta-lactam antibiotics, these soluble molecules may constitute the "natural" immunogen. Such a hypothesis is consistent with the study of the peptidoglycan-binding capacities in the sera of these patients during the course of treatment. For most of the responding patients studied (four of four with bacteremia and seven of nine with endocarditis), a significant increase in peptidoglycan-binding capacity was observed in sera taken 1 to 5 weeks after the initiation of beta-lactam antibiotic therapy (compared with the initial serum studied). No such increase in the peptidoglycan-binding capacity over a similar time span was noted in the sera of people not receiving beta-lactam antibiotics (none of seven).

Anti-Bacterial Agents↗
PubMed1981

Isolated lymphadenitis caused by Candida albicans in a patient with acute leukemia.

Lymphadenitis caused by Candida developed in a patient with acute leukemia but there was no other evidence of disseminated infection. He was successfully treated intravenously with only 800 mg of amphotericin B. The presentation of disseminated candidiasis in immunocompromised hosts is discussed. The unusual finding in this case of Candida infection apparently confined to a lymph node was interpreted as a stage of fungal invasion more limited than the widely disseminated disease. The concept of a locally invasive but nondisseminated Candida infection was the basis for giving this patient a low dose of amphotericin B.

Acute Disease↗
PubMed1981

Variability in the degree of opsonization and phagocytosis of strains of Staphylococcus aureus isolated from patients with disseminated intravascular coagulation.

Patients with septicemia due to Staphylococcus aureus occasionally manifest DIC. We studied the ability of organisms isolated from 30 patients with S. aureus (5 with DIC) to be opsonized and phagocytosed by normal human PMNs in the presence of normal human serum chelated with MgEGTA as a possible measure of alternative complement pathway activation. By this assay, nine S. aureus strains were found to be opsonized at 50% level or greater. Five of those organisms were isolated from the five patients who had clinical and laboratory manifestations of DIC, three of whom died. Patients from whom the other four activating strains were isolated were more seriously ill (by a method of grading clinical severity of disease) than the remaining 21 patients. Four of the nine patients from whom activating strains were isolated died compared to only four of the other 21 patients. The accelerated phagocytosis of staphylococcal strains from patients with DIC after incubation in MgEGTA-chelated serum suggests that surface factors on these strains interacted with serum factors differently than did strains from patients not developing DIC. However, all (except one) staphylococcal strains, from patients both with and without DIC, depleted hemolytic complement activity in MgEGTA-chelated serum; therefore a direct relationship between activation of the alternative complement pathway and opsonization seems not to exist. Thus strains of S. aureus capable of being opsonized by PMNs in human serum chelated with MgEGTA were associated with more severe infections often associated with DIC.

Disseminated Intravascular Coagulation↗
PubMed1980

Disseminated Trichosporon infection. Occurrence in an immunosuppressed patient with chronic active hepatitis.

A 62-year-old woman with chronic active hepatitis receiving immunosuppressive drugs was initially admitted with sepsis secondary to an intra-abdominal abscess caused by Klebsiella pneumoniae. She had a stormy course despite adequate antimicrobial therapy. Her postoperative course was further complicated by a fungal infection. Blood, urine, and sputum cultures were positive for Trichosporon. Antifungal therapy was given but her condition deteriorated and she died. At autopsy, a disseminated fungal infection was found. Diagnosis and management of such infections in the immunosuppressed host are difficult.

Azathioprine↗
PubMed1980

Antimicrobial activity of street heroin.

Street heroin and injection paraphernalia have been implicated as sources of bacteria causing infections in drug abusers [1]. Staphylococcus aureus, Pseudomonas aeruginosa, and Bacillus cereus are common etiologic agents. In a previous study of the microbiology of street heroin and injection paraphernalia, Bacillus species was the predominant isolate [2]. We did not find S. aureus, but one study reported isolates of identical phage type from heroin powder and from an infected patient [3]. To reconcile the results of our recent investigation among drug abusers with panophthalmitis, we theorized that the drug mixture might have an antibacterial effect. Of the samples of street heroin tested, all except one were bactericidal against S. aureus. The single sample with no heroin content was not bactericidal against one isolate of S. aureus and was the only sample that exhibited some degree of inhibitory and bactericidal activity against P. aeruginosa. All samples were bactericidal against the two isolates of B. cereus tested. Quinine exhibited bactericidal activity against S. aureus and B. cereus but was ineffective against P. aeruginosa. Our findings indicate that most samples of street heroin have antibacterial effects against S. aureus and B. cereus but no activity against P. aeruginosa. Such activity may be due to the quinine content of the mixture. The apparent lack of recovery of S. aureus from street heroin may be partially explained by this phenomenon.

Bacillus cereus↗
PubMed1980

Pulmonary emboli 5 days postinjury presenting as fever of unknown origin.

A patient who fell on his right leg from a scaffold presented with fever of unknown etiology. Complete workup to rule out infectious causes for his fever was nonrevealing. Because of a history of transient episodes of dyspnea, lung scan was performed which was compatible with pulmonary emboli. Response to heparin therapy was dramatic. Thus, in patients with history of trauma and are bedridden for a long period of time who present with fever one should have a high index of suspicion for pulmonary emboli.

Adult↗
PubMed1980

Cytotoxic lymphocytes and antibody-dependent complement-mediated cytotoxicity induced by administration of influenza vaccine.

Recently defined aspects of cellular and humoral antiviral immunity were evaluated in 10 young adults given influenza vaccines containing A/USSR/77 (H1N1) antigens. Cytotoxic lymphocytes were measured by using cryopreserved lymphocytes as effector cells and syngeneic, virus-infected lymphocytes as target cells. An assay previously developed in this laboratory was adapted for the measurement of antibody-dependent, complement-mediated cytotoxicity. Antiviral cytotoxic lymphocyte responses were detected in 5 of 10 volunteers between 3 and 10 days after the initial vaccination. These responses were found both in individuals who were previously primed and in individuals who were not primed to influenza A/USSR/77 antigens. The complement-mediated lysis assay was found to be more sensitive than the hemagglutination inhibition test and probably detected antibodies to both subtype-specific and cross-reactive antigenic determinants. These responses to influenza antigens are similar to those obtained in studies of murine influenza which indicate that cytotoxic lymphocytes and antibody-dependent, complement-mediated cytotoxicity have a role in the early response to acute infection.

Adult↗
PubMed1980

Mucormycosis in transplant patients.

Cutaneous mucormycosis in a renal transplant recipient resulted in gangrenous cellulitis of the neck at an internal jugular cannula site. This nosocomial process was due to a histologically confirmed infection, and cultures revealed Mucor sp. The patient died despite surgical debridement and amphotericin B therapy. Cutaneous mucormycosis is a relatively rare entity with only 12 cases previously reported. In renal transplant patients only nine cases of renal transplant patients only nine cases of mucormycosis have been reported and only one was cutaneous. Also, this case reported is the second originating at an intravenous cannula site; the first recorded patient was diabetic.

Amphotericin B↗
PubMed1980

Carriage rate of Staphylococcus aureus among patients receiving allergy injections.

The relative frequency of positive cultures for Staphylococcus aureus was studied among healthy young patients undergoing desensitization for allergies to determine whether the administration of repeated injections under aseptic conditions had any effect on the carriage rate of S. aureus. Three groups of patients were considered: group I, 11 patients receiving injections for the first time; group II, 20 patients already receiving injections; and group III, 20 control patients who did not receive any injections. Skin, nose and throat cultures were obtained once every two weeks for four months. Among group I patients the rate increased from 18% to 55% following the first injection, after which it fell to a 30-35% level. A rate of 25-35% was found in group II patients as compared to 15-20% in group III. Skin carriage of Staphylococcus aureus was found only among group I and group II patients. No local or systemic staphylococcal infections were found during the course of the study. The initial increase in carriage rate of staphylococcus among the healthy young adults in group I is unexplained. Thus, the results of this study further support our initial theory than regular use of needles alone increases the carriage rate of S. aureus, even under strict aseptic conditions.

Adult↗
PubMed1979

Serious infections from Bacillus sp.

Serious infections caused by organisms of the genus Bacillus developed in seven patients. Five drug abusers had either endocarditis or osteomyelitis, one leukemic patient had necrotizing fasciitis, and one patient had a ventriculoatrial shunt infection with recurrent bacteremia. All patients recovered. Experience with these cases reemphasizes the importance of not dismissing Bacillus organisms as culture contaminants, especially when isolated from blood, body fluids, or closed-space infections.

Adolescent↗