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Biomedical subjects

C C Patrick

Publications and source records attributed to C C Patrick.

At least 19 recordsLinked to original sources
PubMed1999

Stability and sterility of a recombinant factor VIII concentrate prepared for continuous infusion administration.

Minipumps may facilitate cost-effective and convenient continuous infusion (CI) therapy for severe hemophilia A. This study evaluated the in vitro sterility, ability to support bacterial growth, and specific activity stability of a recombinant factor VIII (FVIII; Bioclate, Centeon) delivered by simulated CI at a variety of temperatures and after the addition of heparin or antibiotic. Closed system CIs of Bioclate (89.5 IU/ml) with and without heparin were sampled and cultured over a 6 day period. Bioclate (53.7 IU/ml) with and without heparin or vancomycin was inoculated with 102-105 CFU/ml of S. aureus, S. epidermidis, Escherichia coli, E. cloacae, or Y. enterocolitica and assessed by quantitative culture after 1 and 3 days. The stability of Bioclate (50, 100, and 250 IU/ml) at three temperatures (21 degrees C, 37 degrees C, and 39 degrees C) with and without heparin or vancomycin was tested over a period of 28 days. FVIII activity was measured in triplicate by a chromogenic assay (Coamatic Factor VIII, Chromogenix) and purity evaluated by Western blot. No bacterial growth was detected during CI of FVIII for up to 6 days. Following bacterial inoculation, there was rapid growth (>3 log increase) of all tested bacterial species except S. aureus which only displayed a 1 log expansion at 3 days. The addition of heparin containing 9.45 microg/U benzyl alcohol had no effect on bacterial growth. The addition of vancomycin caused a modest suppression of S. aureus growth but not of E. coli. Diluent alone did not support bacterial growth. Neither concentration, increased temperature, nor the addition of heparin or vancomycin had a significant effect on FVIII activity stability. Samples retained >75% baseline activity for between 3 and 7 days, except the infusion of Bioclate 50 IU/ml plus heparin maintained at 21 degrees C which remained stable for 28 days. Western blot analysis supported the activity assay findings. Standard and concentrated preparations of Bioclate are suitable for CI when delivered by the MiniMed 404-SP minipump. Because of the observed nutritive capability of this FVIII concentrate for sustaining bacterial growth, any contamination could result in systemic infection.

Bacteria↗
PubMed1999

Adenovirus infection after pediatric bone marrow transplantation.

Retrospective analysis of 206 patients undergoing 215 consecutive bone marrow transplants (BMT) at St Jude Children's Research Hospital between November 1990 and December 1994 identified 6% (seven male, six female) with adenovirus infection. The affected patients had a median age of 7.9 years (range 3-24 years) at time of transplantation. Although transplants were performed for hematologic malignancies, solid tumors or nonmalignant conditions, only patients with hematologic malignancies had adenoviral infections. Adenovirus was first detected at a median of 54 days (range -4 to +333) after BMT. Adenovirus developed in eight of 69 (11.6%) patients receiving grafts from matched unrelated or mismatched related donors, in four of 52 (7.7%) receiving grafts from HLA-matched siblings, and in one of 93 (1.1%) receiving autografts. The most common manifestation of adenovirus infection was hemorrhagic cystitis, followed by gastroenteritis, pneumonitis and liver failure. The incidence of adenovirus infection in pediatric BMT patients at our institution is similar to that reported in adult patients. Using univariate analysis, use of total body irradiation and type of bone marrow graft were significant risk factors for adenovirus infection. Only use of total body irradiation remained as a factor on multiple logistic regression analysis.

Adenoviridae Infections↗
PubMed1999

Fungal susceptibility testing.

The utility of antifungal susceptibility testing has not been broadly determined. Thus, susceptibility testing of fungal isolates is not recommended on a routine basis. For instance, susceptibilty testing may be considered for some Candida species and for patients with Pseudallescheria boydii infections. Testing of yeasts for susceptiblity to azoles is of particular value due to their variability in response to these agents. It may also be important to test the susceptibility of new fungal organisms not previously identified or known to cause human disease because in these situations there are no clinical reports of efficacy to guide the choice of antifungal therapy.

Antifungal Agents↗
PubMed1998

Hepatitis G Virus.

Explore the source record for details and available documents.

Flaviviridae↗
PubMed1997

The role of esophagoscopy in diagnosis and management of esophagitis in children with cancer.

Esophagitis is a common complication in patients treated for cancer; however, difficulty in determining its etiology on the basis of noninvasive clinical information limits the implementation of specific therapies. We reviewed our experience with esophagoscopy and biopsy as an aid in the diagnosis and management of esophagitis in children with cancer. Of eleven episodes of esophagitis evaluated by esophagoscopy with biopsy, four (36%) had an infectious etiology (two with Candida, one with Herpes simplex virus, and one with viridans streptococci). The absolute neutrophil count, presence of oropharyngeal colonization, and appearance of the esophagus at esophagoscopy were not predictive of the etiology of esophagitis. Esophagoscopy with biopsy affected the management of 4 (36%) patients. We believe this procedure to be a valuable aid in managing esophagitis in children with cancer by providing objective data not otherwise available to the clinician.

Adolescent↗
PubMed1997

Viridans streptococcal isolates from patients with septic shock induce tumor necrosis factor-alpha production by murine macrophages.

Viridans streptococci are an important cause of bacteremia and septic shock in neutropenic patients, especially patients receiving chemotherapeutic agents that induce severe mucositis. The mechanisms by which viridans streptococci cause septic shock are unclear. We hypothesized that septic shock due to viridans streptococci is attributable to host cytokine production. Three clinical isolates of viridans streptococci were evaluated for their ability to induce production of tumor necrosis factor-alpha (TNF-alpha) by RAW 264.7 murine macrophages. These three strains of viridans streptococci induced TNF-alpha in a dose-dependent fashion, and the kinetics of TNF-alpha induction were similar to those observed with a clinical isolate of Escherichia coli.

Animals↗
PubMed1997

Use of fluoroquinolones as prophylactic agents in patients with neutropenia.

BACKGROUND: The use of fluorinated quinolone antibiotics to selectively decontaminate the gastrointestinal tract is a reasonable alternative to prevent infection in neutropenic patients. The fluoroquinolones represent ideal antibiotics with which to achieve the principles of selective decontamination by allowing colonization of anaerobes to inhibit the adherence, colonization and proliferation of potentially pathogenic aerobic flora. OBJECTIVE: This report describes the prophylactic use of fluoroquinolones in neutropenic patients. RESULTS: The majority of studies of fluoroquinolone prophylaxis in neutropenic patients have shown a reduction in documented Gram-negative bacterial infections. However, Gram-positive infections, particularly those with viridans streptococci, present a major impediment to the use of single agent prophylaxis with a quinolone. CONCLUSION: Prophylaxis with fluoroquinolones in neutropenic patients was found to be advantageous, but it must be balanced against the risk of Gram-positive infections and the potential for antibiotic resistance.

Anti-Infective Agents↗
PubMed1996

Lipoteichoic acid from viridans streptococci induces the production of tumor necrosis factor and nitric oxide by murine macrophages.

Bacterial endotoxin or lipopolysaccharide is the major proinflammatory component of gram-negative bacteria, but the components of gram-positive bacteria that trigger the inflammatory cascade are poorly understood. Lipoteichoic acid (LTA) purified from 2 strains of viridans streptococci induced the accumulation of tumor necrosis factor (TNF) mRNA and protein by the murine macrophage cell line RAW 264.7 in a dose- and time-dependent manner. Furthermore, in the presence of recombinant interferon-gamma, LTA from both strains of viridans streptococci provoked the accumulation of inducible nitric oxide (NO) synthase mRNA and the production of NO. Together these observations indicate that LTA can trigger macrophage activation and the production of TNF and NO and suggest that LTA may be an important determinant of the host inflammatory response to gram-positive infection.

Animals↗
PubMed1995

Diagnostic utility of thoracentesis for neutropenic children with cancer.

Thoracentesis is a procedure often performed in children with pleural effusions to assist in diagnosis and management. Its safety and utility for immunocompromised patients with neutropenia (absolute neutrophil count, <1,500 polymorphonuclear leukocytes and band forms per microL) is unclear. We reviewed our experience over a 10-year period to evaluate the role of thoracentesis for neutropenic children with cancer who had pulmonary effusions of presumed infectious etiology. Twenty-two patients were identified, and 18 had absolute neutrophil counts of < or = 500/microL. Empirical antibiotics had been administered to 95% of these patients and antifungal agents to 72%. Two patients' cultures were positive for fungal organisms: Aspergillus terreus in one case and Candida albicans in the other. Both of these patients had been receiving antifungal therapy. Therapy was altered for these two patients plus one additional patient in whose pleural fluid tumor cells were unexpectedly found. Eight of the remaining 19 patients underwent another diagnostic procedure, yielding five additional diagnoses. In conclusion, thoracentesis is safe and should be considered as a diagnostic test for febrile neutropenic patients with pulmonary effusions of presumed infectious etiology, although more invasive tests may be warranted.

Adolescent↗
PubMed1995

Sequence and analysis of the rpoB gene of Mycobacterium smegmatis.

The rpoB gene encodes the beta subunit of the DNA-dependent RNA polymerase of bacteria. Mutations in defined areas result in resistance to rifampin. Mycobacterium smegmatis is naturally resistant to rifampin, but analysis of the rpoB gene revealed no identifiable rifampin resistance mutations. Another mechanism of resistance may be present.

Amino Acid Sequence↗
PubMed1995

Comparative virulence of Staphylococcus epidermidis isolates in a murine catheter model.

Among coagulase-negative staphylococci, Staphylococcus epidermidis is the species most commonly implicated in catheter-related infections. Whether some staphylococcal organisms are inherently more virulent than others, or whether their ability to infect relates more to the sheer numbers of organisms at the catheter site, remains unclear. We therefore compared eight S. epidermidis isolates and two other coagulase-negative staphylococci using a murine model that allowed us to quantify catheter colonization and abscess formation in the same animal. The organisms were isolated from different clinically relevant settings and were classified according to their slime phenotype. The ability to evoke abscesses or colonize catheters in half of the animals (ID50) was assessed. ID50 inoculum titers (log10 data +/- SD) ranged widely, from 8.5 +/- 0.3 to 10.2 +/- 0.2 for abscess formation (p < 0.005) and from 7.5 +/- 0.5 to 10.3 +/- 1.0 for catheter colonization (p < 0.005). ID50 values by statistical criteria suggested variability among organisms in the ability to induce abscess formation. High slime production correlated with both parameters, but not with the clinical source of the isolate. Our findings demonstrate impressive heterogeneity in the ability of a representative group of S. epidermidis isolates to colonize catheters and to evoke abscess formation and implicate slime productivity as a major virulence factor. The murine model used permitted simultaneous analysis of multiple factors involved in pathogenesis and should be useful in establishing the basis of S. epidermidis pathogenicity.

Abscess↗
PubMed1994

Pseudomonas aeruginosa bacteremia in immunocompromised children: analysis of factors associated with a poor outcome.

We identified 98 children and adolescents with cancer who were treated for Pseudomonas aeruginosa bacteremia over a 27-year period. The most common underlying disease was leukemia (lymphoblastic in 63 cases and myeloblastic in 17); in addition, 12 episodes were associated with solid tumors and 6 with other diagnoses. There were 29.5 episodes of P. aeruginosa bacteremia/1,000 cases of acute lymphoblastic leukemia, with a mortality of 27%, and 29.8 episodes/1,000 cases of acute myeloblastic leukemia, with a mortality of 24%; patients with solid tumors had an incidence of 5.0/1,000 cases and a mortality of 58% (P = .01 for mortality in leukemia vs. mortality in solid tumors, logistic regression analysis). Mortality was lower among children who developed bacteremia during remission therapy or induction therapy than among children who were being treated for relapse (P = .001). The majority (78%) of the 76 evaluated cases developed during periods when the absolute neutrophil count (ANC) was < 0.1 x 10(9)/L; mortality was higher among patients with such counts than among those with higher ANCs (36% vs. 14%, P = .04). Logistic regression analysis showed that perineal skin lesions were associated with higher mortality than were lesions at other sites of skin involvement (54% vs. 23%, P = .04).

Adolescent↗
PubMed1994

Monoclonal antibodies against a 97-kilodalton antigen from Aspergillus flavus.

We prepared a panel of five monoclonal antibodies (MAbs) directed against Aspergillus flavus that all reacted against one 97-kDa antigen by western blot (immunoblot). Flow cytometry demonstrated that these antibodies bound (in increasing degrees) to all morphologic stages of A. flavus growth: conidia, swollen conidia, and hyphae. Cross-reactivity among species was examined by enzyme-linked immunosorbent assay of fungal culture filtrates. Four MAbs reacted with 10 of 11 A. flavus isolates, and the fifth one reacted with 9 of them. One MAb also reacted with A. fumigatus, two reacted with A. niger, A. wentii, and A. nidulans, and all five reacted with A. ochraceus. None reacted with A. terreus, A. glaucus, A. versicolor, or a Penicillium species. Each MAb bound to A. flavus hyphae in formalin-fixed paraffin sections of a muscle biopsy from a confirmed human case of invasive aspergillosis. In summary, these MAbs identified a 97-kDa antigen found on A. flavus that is both surface bound and an exoantigen. Either the same or a cross-reacting antigen is present in A. fumigatus and other Aspergillus species.

Animals↗
PubMed1993

Variation in phenotypic expression of the Opa outer membrane protein and lipooligosaccharide of Neisseria meningitidis serogroup C causing periorbital cellulitis and bacteremia.

Expression of the Opa outer membrane protein varies widely among isolates of Neisseria meningitidis; the clinical significance of this variation is unclear. A sialic-acid acceptor is present in the lipooligosaccharide of some strains of Neisseria and has been shown to render Neisseria gonorrhoeae serum-resistant. We report the case of a patient who had an unusual clinical manifestation of infection due to N. meningitidis serogroup C, periorbital cellulitis with concomitant bacteremia. Clinical isolates from the blood and aspirate of the periorbital cellulitis were identical except for the phenotypic expression of the Opa outer membrane protein in the isolate from the periorbital cellulitis and in the lipooligosaccharide phenotype of the sialic-acid acceptor as defined by monoclonal antibodies. We discuss the laboratory and clinical implications of these findings.

Antigens, Bacterial↗
PubMed1993

Cunninghamella infections: review and report of two cases of Cunninghamella pneumonia in immunocompromised children.

Infections caused by Cunninghamella bertholletiae are being identified with increasing frequency in immunocompromised patients. We have treated two children with cancer for pulmonary infections caused by this rare fungus. Cunninghamella infection is found in a variety of populations of patients, including both children and adults undergoing chemotherapy. Clinical signs and symptoms are indistinguishable from those of other forms of zygomycosis. Outcome is poor: only three of 17 patients with such infection (including one of the two children described herein) have survived. Treatment involves aggressive surgical excision and administration of amphotericin B.

Child↗