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Biomedical subjects

K H Rhodes

Publications and source records attributed to K H Rhodes.

At least 19 recordsLinked to original sources
PubMed1996

Yield of positive blood cultures in pediatric oncology patients by a new method of blood culture collection.

BACKGROUND: The optimal number of blood cultures and the volume of blood for pediatric blood cultures have not been defined. In 1990 such criteria were established at our institution. We retrospectively reviewed records of all pediatric oncology patients who were admitted for febrile episodes in 1989 and in 1991 and 1992 to determine whether there was an increase in the detection of bacteremia and fungemia. METHODS: Blood was drawn via venipuncture and central intravascular catheters and inoculated into the designated blood culture bottles. Each patient had a minimum of two separate blood draws, i.e. two separate cultures; the volume was determined by the patient's weight. In all cases < 1% of the patient's blood volume was drawn per culture. Patients' records were reviewed regarding type of malignancy, chemotherapy and neutropenia. RESULTS: The rate of bacteremic patients increased from 12% (13 of 113) in 1989 to 22% (27 of 123) in 1991. This increase continued through 1992 with 23% (27 of 118) of patients having positive blood cultures. Gram-positive bacteria predominated throughout the study period. CONCLUSIONS: Although factors such as more aggressive chemotherapy or a different spectrum of malignant diseases may contribute to the statistically significant increase in identification of bacteremic patients, a standardized method of blood culture collection is merited. The consistent volumes of blood per culture and the minimum of two cultures per febrile episode follow the principles of blood culture collection established for adults. The same principles should apply to pediatric patients.

Adolescent↗
PubMed1992

Antibiotic therapy for severe infections in infants and children.

In infants and children, the absorption, distribution, metabolism, and excretion of drugs may differ considerably in comparison with these factors in adults; consequently, differences exist in therapeutic efficacy and toxicity of various antibiotic agents. Because of known toxicity, certain drugs--such as chloramphenicol in high doses, the sulfonamides, and tetracycline--should not be used in neonates. Antibiotic therapy should be modified in neonates because of biologic immaturity of organs important for the termination of drug action. Because of poor conjugation, inactivation, or excretion, the serum concentrations of many antibiotics may be higher and more prolonged in neonates than in older infants; thus, lower doses and longer intervals between administration may be necessary. In this article, we suggest dosages of antimicrobial agents for severe infections in children, older infants, and neonates. Included in the discussion are the cephalosporins, especially the third-generation cephalosporins that have assumed an important role in empiric treatment of bacterial meningitis in pediatric patients because of their ability to penetrate the central nervous system and their effectiveness against beta-lactamase-positive and negative strains of Haemophilus influenzae type b, Streptococcus pneumoniae, Neisseria meningitidis, and many gram-negative bacteria in the Enterobacteriaceae group. In patients with congenital or acquired immunodeficiencies, antifungal, antiviral, or anti-Pneumocystis agents are often added to the antimicrobial regimen for severe infections. We review the agents available for such treatment in children, the drugs used for childhood tuberculosis, and certain new antibiotics (aztreonam, ticarcillin-clavulanate, ciprofloxacin, and imipenem-cilastatin) that have proved useful in select cases but whose precise role in pediatric practice will necessitate additional clinical experience.

Anti-Bacterial Agents↗
PubMed1992

Musculoskeletal and soft tissue Aeromonas infection: an environmental disease.

During a 4-year period from November 1985 to November 1989, Aeromonas was isolated from wounds and soft tissues with clinical evidence of infection in 28 patients at our institution. Of the 28 patients, 23 (82%) had sustained an acute open or penetrating injury, more than half of which (13 of the 23) were water-related trauma. One patient had Aeromonas osteomyelitis. Five patients had no history of trauma, and three of these five had an underlying chronic disease. Treatment included débridement and antimicrobial agents. Susceptibility testing on 25 isolates from 23 patients showed uniform resistance to ampicillin and considerable resistance to cefazolin sodium (68%), but all isolates were sensitive to gentamicin sulfate, cefuroxime sodium, and the third-generation cephalosporins.

Academic Medical Centers↗
PubMed1991

Defective T-lymphocyte signal transduction and function in leukocyte adhesion deficiency.

The lymphocyte function-associated antigen-1 (LFA-1) molecule is a cell surface heterodimeric protein that directly mediates cellular adhesion. However, it remains unclear whether LFA-1 molecules are also involved in transmembrane signaling and in the subsequent regulation of cellular functions. Previous attempts to evaluate this issue have been hampered by (1) the ubiquitous expression of LFA-1 on normal lymphoid cells, (2) the limited availability of assays for cellular activation that are not affected by cellular adhesion, and (3) the difficulties in interpreting studies where anti-LFA-1 mAbs are used to alternatively block or stimulate this antigen. In order to avoid these pitfalls, we first isolated and cloned T lymphocytes from a patient with leukocyte adhesion deficiency (LAD), an inherited disorder in which the defective expression of leukocyte integrins results in the production of LFA-1- T lymphocytes. Different T-cell lines from this patient and from normal individuals were then stimulated through their T-cell antigen receptor complex and were then tested for three aspects of cellular activation: (1) transmembrane signaling (i.e., phosphoinositide turnover), (2) lymphokine secretion (i.e., release of lymphotoxin), and (3) their capacity to mediate cellular cytotoxicity (using murine anti-CD3-producing hybridoma cells as targets). Using assay systems that did not involve LFA-1-mediated adhesion to antigen-presenting cells or target cells, the T-cell lines from the LAD patient were found to be intrinsically defective in all three of these parameters of T cell activation.(ABSTRACT TRUNCATED AT 250 WORDS)

Cell Adhesion↗
PubMed1990

Infection after farm machine-related injuries in children and adolescents.

Infection played an important role in prolonging hospitalization and increasing morbidity in 68 children injured in farm settings. Predominantly gram-negative enteric organisms, group D streptococci, and anaerobic organisms were isolated in cultures of specimens obtained from wounds. Infection was more often associated with severe injuries of the large bones of the extremities than in amputation injuries of the digits and crush or roll-over injuries when the skin barrier was intact. The occurrence of infection in farm injuries was associated with prolonged hospitalization for parenteral antibiotic therapy, multiple surgical débridements with a need for general anesthesia, and permanent disability (decreased range of motion and loss of limbs and digits). Early aggressive surgical débridement and antimicrobial therapy guided by isolation and sensitivity testing of the major organisms are required because of polymicrobial invasion of vascularly compromised tissue.

Accidents, Occupational↗
PubMed1990

Cutaneous manifestations of canine and feline endocrinopathies.

Endocrinopathies in domestic animals exhibit a variety of metabolic abnormalities. Cutaneous manifestations of these disorders are more limited and are primarily characterized as a bilaterally symmetric nonpruritic alopecia. Subtle changes in skin texture, thickness, fragility, etc. may, in some cases, aid in establishing a diagnostic plan.

Animals↗
PubMed1987

Antibiotic therapy for severe infections in infants and children.

In infants and children, drug absorption, distribution, metabolism, and excretion may differ considerably from these factors in adults; thus, differences also exist in therapeutic efficacy and toxicity of various antibiotics. Because of known toxicity, certain drugs--such as chloramphenicol in high doses, the sulfonamides, and tetracycline--should not be used in neonates. Antibiotic therapy should be modified in neonates because of biologic immaturity of organs important for the termination of drug action. Because of poor conjugation, inactivation, or excretion, the serum concentrations of many antibiotics may be higher and more prolonged in neonates than in older infants. Thus, the dosages of many antibiotics must be lower and the intervals between administration must be longer. The appearance of strains of ampicillin-resistant Haemophilus influenzae, the slow development of resistance to chloramphenicol among gram-negative and gram-positive bacteria, and the development of improved analytic methods to measure chloramphenicol have all resulted in the use of this drug in select cases of serious infection in children beyond the neonatal age. Third-generation cephalosporins have an important role in empiric treatment of pediatric bacterial meningitis because of their ability to penetrate the central nervous system and their effectiveness against ampicillin- or chloramphenicol-resistant Haemophilus strains and against many gram-negative bacteria in the Enterobacteriaceae group.

Anti-Bacterial Agents↗
PubMed1982

Pediatric endocarditis.

Infective endocarditis is a rare disease in the general pediatric population. Nonetheless, children with congenital heart disease have a substantial lifetime risk for development of endocarditis, and recent advances in the management of these children should increase the number of patients who survive infancy and early childhood. During the 30-year period from 1950 through 1979, 50 cases of endocarditis in children were diagnosed at the Mayo Clinic. Of these 50 patients, 37 had congenital heart disease, and 8 were diagnosed as having endocarditis within 3 months after having undergone a cardiac surgical procedure. Nineteen patients died of the disease or its complications. The most common organism isolated at Staphylococcus aureus (19 patients), followed by viridans streptococci (14 patients). Children younger than 10 years of age experienced a particularly high mortality, as did patients of all ages with S. aureus infection. Any unexplained fever in a child with congenital heart disease deserves close investigation; if endocarditis is suspected, early empiric antibiotic therapy is indicated after appropriate culture specimens have been obtained. Moreover, localized bacterial infections in children at risk must be treated aggressively to prevent metastatic spread to the heart.

Adolescent↗
PubMed1980

Infectious mononucleosis complicated by severe Mycoplasma pneumoniae infection.

A 14-year-old girl with infectious mononucleosis and secondary immunosuppression had severe dyspnea and cough, spiking fever, rales, and diffuse bilateral pulmonary infiltrates. The pulmonary disease progressed rapidly, necessitating empiric trials of antimicrobial agents. Mycoplasma pneumoniae was isolated from a lung biopsy specimen, transtracheal aspirate, and expectorated sputum, but the relatively long period required to isolate the organism delayed the microbiologic diagnosis. Serologic study of acute and convalescent serum samples confirmed the M pneumoniae infection. Clinical improvement was gradual, and the immunosuppression was transient. The patient's illness appeared to represent microbial synergism, with severe M pneumoniae infection complicating transient immunosuppression induced by infectious mononucleosis.

Adolescent↗
PubMed1980

Nosocomical Rhizopus infection (zygomycosis) in children.

Three children with the rare occurrence of zygomycosis are descibed: two had involvement of a solitary lesion of gangrenous cellulitis on the buttocks, and th third was a neonate with gastric performation and a gangrenous appendicitis. All three patients were compromised hosts (two with leukemia and one a premature infant with respiratory distress syndrome). All three patients appeared to have acquired the same organism. Rhizopus oryzae, from the same fomites, elastic bondages (Elastoplast). The Center for Disease Control has received several other reports of zygomycosis traceable to the same material. Alll three of our patients were cured of their infections. Early diagnosis and a combined surgical and chemotherapeutic approach appear to prevent death from zygomycosis.

Amphotericin B↗
PubMed1980

Etiology and outcome in 42 children with acute nonbacterial meningoencephalitis.

In a prospective study of 42 cases of childhood meningoencephalitis occurring in 1974 and 1975, a diagnosis of an infectious agent was made in 30 (71%). California virus infections were most common; they were serious illnesses but had few sequelae. Benign illnesses with enteroviruses were also common. Miscellaneous and unknown agents accounted for the most seriously ill patients and for both deaths. Persistent neurologic deficits were unusual. Headaches, malaise, and changes in behavior were common but transient.

Acute Disease↗