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Biomedical subjects

C C John

Publications and source records attributed to C C John.

9 recordsLinked to original sources
PubMed2000

Spinal epidural abscesses in children: a 15-year experience and review of the literature.

We reviewed medical records and laboratory and diagnostic evaluations for 8 pediatric patients with spinal epidural abscesses who were treated during the last 15 years at our institution. Staphylococcus aureus was isolated from 5 of 8 epidural abscesses, including 2 abscesses with methicillin-resistant S. aureus. Unusual isolates were group B Streptococcus in a patient with chronic vesicouretral reflux associated with the posterior urethral valves and Aspergillus flavus in a patient with acute myelogenous leukemia. An analysis incorporating our results and a review of the English-language literature about abscesses in children and adults revealed differences related to age. Abscesses in children were more posterior in epidural location, had greater spinal column extension, and were associated with more favorable clinical outcomes than were abscesses in adults. Magnetic resonance imaging is the diagnostic procedure of choice; however, radionuclide bone scans should be considered for associated distant osteomyelitis in children. Prompt diagnosis and combined medical and surgical treatment remain the cornerstones for the prevention of adverse outcomes.

Adolescent↗
PubMed2000

Cytokine responses to Plasmodium falciparum liver-stage antigen 1 vary in rainy and dry seasons in highland Kenya.

Seasonal epidemics of malaria occur in highland areas of western Kenya where transmission intensity varies according to rainfall. This study describes the seasonal changes in cytokine responses to Plasmodium falciparum liver-stage antigen 1 (LSA-1) by children (< or =17 years old) and adults (> or =18 years old) living in such a highland area. Fourteen- to 24-mer peptides corresponding to the N- and C-terminal nonrepeat regions of LSA-1 stimulated production of interleukin-5 (IL-5), interleukin-10 (IL-10), gamma interferon (IFN-gamma), and tumor necrosis factor alpha (TNF-alpha) by peripheral blood mononuclear cells (PBMC) from 17 to 73% of individuals in both age groups in both seasons. IL-10 and TNF-alpha responses were more frequent during the high-transmission, rainy season than during the low-transmission, dry season (73 and 67% versus 17 and 25% response rates, respectively). In contrast, there was no seasonal change in the proportion of LSA-1-driven IFN-gamma and IL-5 responses. Children produced less IFN-gamma than adults, but IL-5, IL-10, and TNF-alpha levels were similar for both age groups. Depletion of CD8(+) cells from PBMC decreased IFN-gamma but increased IL-10 production. Individuals with LSA-1-stimulated IL-10 responses in the dry season were less likely to become reinfected in the subsequent rainy season than those without IL-10 responses (25% versus 49%; P = 0.083). These data support the notion that maintenance of LSA-1-driven IL-10 and TNF-alpha responses requires repeated and sustained exposure to liver-stage P. falciparum. In contrast, IFN-gamma responses increase slowly with age but persist once acquired. CD8(+) T cells are the major source of IFN-gamma but may suppress production or secretion of IL-10.

Adolescent↗
PubMed1999

Increased levels of soluble interleukin-4 receptor in the sera of patients with visceral leishmaniasis.

Kenyan subjects with visceral leishmaniasis were examined for evidence of increased production of soluble interleukin-4 receptor (sIL-4R). Soluble IL-4R regulates the bioactivity of IL-4, a cytokine important in mediating progressive forms of leishmaniasis. Persons with visceral leishmaniasis sustained 8- to 10-fold more circulating sIL-4R compared with Papua New Guinea residents with documented filariasis or uninfected Kenyan and North American subjects. Soluble IL-2R concentrations were elevated nonspecifically in both visceral leishmaniasis and filariasis patients. These findings are significant given that IL-4 induces sIL-4R in mice, and treatment with recombinant sIL-4R cures progressive murine leishmaniasis dependent on IL-4 bioactivity. Further studies are indicated to determine whether the immunologic detection of IL-4 produced in human visceral leishmaniasis is obscured because of sequestration by soluble receptor and whether the production of sIL-4R is relevant to the pathogenesis of visceral leishmaniasis.

Animals↗
PubMed1994

Flogging trolls.

Explore the source record for details and available documents.

Internship and Residency↗
PubMed1994

Treatment failure with use of a third-generation cephalosporin for penicillin-resistant pneumococcal meningitis: case report and review.

Recent reports have documented the increasing number of pneumococcal isolates that are relatively or completely resistant to penicillin and other antibiotics. This report documents a case in which third-generation cephalosporin failed in the treatment of pneumococcal meningitis and reviews the clinical and microbiological features of the seven similar cases reported to date. In all eight cases, the pneumococci were penicillin resistant. Taken together, these cases suggest that (1) children with intermediately penicillin-resistant pneumococcal meningitis (MIC, 0.1-1.0 micrograms/mL) who are treated with cefotaxime or ceftriaxone should be observed carefully for treatment failure and (2) children with highly penicillin-resistant pneumococcal meningitis (MIC, > or = 2.0 micrograms/mL) are best treated with vancomycin and rifampin until the MICs of cefotaxime and ceftriaxone for the pneumococcus are known.

Cefotaxime↗