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Biomedical subjects

R F Jacobs

Publications and source records attributed to R F Jacobs.

At least 37 records · Page 2Linked to original sources
PubMed1997

Human monocytic ehrlichiosis in children.

BACKGROUND: Much of what is known about human monocytic ehrlichiosis (HME) is based upon studies with adult patients. PURPOSE: To review our experience with HME to better understand the epidemiology, clinical manifestations, and outcome of this disease in children. METHODS: Demographic, clinical, and laboratory data were gathered after review of the medical records of patients identified with HME. RESULTS: Twelve patients with an median age of 7.4 years (range, 7 months to 13.7 years) were identified with HME; 10 were white, 7 were male, and 10 were from hometowns of <800 people. Eight patients presented from May through July, and 8 had a history of tick bites. Symptoms demonstrated by the patients during their illness included fever (100%), rash (67%), myalgias (58%), and vomiting, diarrhea, and headache (25%). On presentation, patients demonstrated thrombocytopenia (92%), elevated liver function tests (91%), lymphopenia (75%), hyponatremia (67%), leukopenia (58%), and anemia (42%) on the initial laboratory examination. Four patients presented in shock and 3 required blood pressure support and mechanical ventilation for a median of 10 days (8 to 37 days). These complicated patients required longer hospitalization (19.5 days vs 5. 5 days) and attained higher blood urea nitrogen levels (42.5 mg/dL vs 10 mg/dL) than the patients not presenting with shock. Morbidity associated with HME patients included a decrease in cognitive and neurologic performance. CONCLUSIONS: More information and long-term follow-up is required to understand the full spectrum of disease and morbidity associated with HME in children.

Administration, Oral↗
PubMed1996

Blastomycosis in children.

Infections due to Blastomyces dermatitidis are not commonly encountered in children and adolescents. Knowledge of the diagnosis and treatment of this disease is largely based upon experience with adult patients. We recently reviewed our experience with blastomycosis to evaluate the difficulties in diagnosis and treatment of this disease in the pediatric population. Ten patients with blastomycosis were identified during our review, and five had pulmonary disease alone. Of these five patients, four required open-lung biopsy for diagnosis, even though three had previously undergone bronchoalveolar lavage. The response to treatment with the oral azole antifungal agents (ketoconazole, fluconazole, and itraconazole) was limited, and the agent with the greatest success remains amphotericin B. Until more data are available, amphotericin B should be used for complicated and life-threatening cases of blastomycosis. If oral azole agents are used for non-life-threatening cases, patients should be followed closely, and if clinical deterioration occurs or serum levels of medications are not adequate, then amphotericin B should be substituted for the oral azole agent.

Adolescent↗
PubMed1996

Application of the polymerase chain reaction to the diagnosis and management of neonatal herpes simplex virus disease. National Institute of Allergy and Infectious Diseases Collaborative Antiviral Study Group.

Cerebrospinal fluid (CSF) specimens from 77 neonates with herpes simplex virus (HSV) disease were evaluated retrospectively by polymerase chain reaction (PCR). Samples were collected from 202 infants enrolled in a National Institute of Allergy and Infectious Diseases Collaborative Antiviral Study Group trial that compared vidarabine with acyclovir for the treatment of neonatal HSV infection. HSV DNA was detected in the CSF of 26 (76%) of 34 infants with CNS disease, in 13 (93%) of 14 infants with disseminated infection, and in 7 (24%) of 29 with skin, eye, or mouth (SEM) involvement. One of the 7 PCR-positive SEM patients subsequently developed severe neurologic impairment. Eighteen (95%) of 19 infants with positive CSF PCR results after the completion of 10 days of antiviral therapy experienced significant morbidity or mortality. Application of PCR to neonatal HSV disease may provide additional information on which clinical decisions may be based, although its diagnostic utility outside the research setting is unproven.

Brain↗
PubMed1996

Relationship of MICs to efficacy of cefotaxime in treatment of Streptococcus pneumoniae infections.

In June 1993, the National Committee for Clinical Laboratory Standards (NCCLS) recommended stringent new interpretive guidelines for antibiotics indicated for Streptococcus pneumoniae meningitis. To assess the predictive values of the recommended breakpoints, retrospective data were collected from patients who had S. pneumoniae infections and were treated with cefotaxime monotherapy. Susceptibilities based on the NCCLS interpretative categories were compared with clinical and bacteriologic outcomes. In 76 evaluable patients, the most common infections were bacteremia-septicemia (n = 49), meningitis (n = 37), and lower respiratory tract infection (n = 14). Under the NCCLS breakpoints proposed in 1993, 55 isolates would have been classed as susceptible to cefotaxime (MIC, < or = 0.25 microgram/ml), 18 would have been classed as intermediate (MIC, 0.5 to 1.0 microgram/ml), and 2 would have been classed as resistant (MIC, > or = 2 micrograms/ml). Of 75 cefotaxime-treated patients for whom cefotaxime MICs were recorded, 73 were clinically cured or improved (37 of 37 with meningitis and 36 of 38 with other infections). One case of bacteremia and one case of bone-and-joint infection were scored as therapeutic failures because initial monotherapy had to be modified because of an adverse drug reaction. Excluding these patients, there were 18 patients infected with S. pneumoniae that would have been classed as not fully susceptible (i.e., MICs > or = 0.5 microgram/ml); all of these patients were cured or improved. The results of this analysis demonstrate that successful treatment with cefotaxime did not correlate well with the guidelines for the susceptibility of pneumococcal isolates to either penicillin or cefotaxime established by the 1993 NCCLS breakpoint recommendations. Because of this study and other similar findings, the NCCLS adopted more clinically relevant guidelines in 1994.

Aged↗
PubMed1996

Community-acquired fungal pneumonia in children.

Pediatric fungal pulmonary infections are being seen with increasing frequency. The dimorphic fungi Histoplasma capsulatum. Blastomyces dermatitidis, Coccidioides immitis, and Cryptococcus neoformans frequently cause infections that are asymptomatic. However, patients may suffer pneumonia and disseminated disease. Diagnosis can be made definitively by isolation of the causative organism, but serology or skin testing is often necessary when this is not successful. Severe or life threatening infections are treated with amphotericin B. Recently, new oral azole antifungals are being used more frequently for mild to moderate disease with good success.

Antifungal Agents↗
PubMed1996

Tularemia.

Explore the source record for details and available documents.

Adolescent↗
PubMed1995

Sequential, single-dose pharmacokinetic evaluation of meropenem in hospitalized infants and children.

Meropenem is a new carbapenem antibiotic which possesses a broad spectrum of antibacterial activity against many of the pathogens responsible for pediatric bacterial infections. In order to define meropenem dosing guidelines for children, an escalating, single-dose, pharmacokinetic study at 10, 20, and 40 mg/kg of body weight was performed. A total of 73 infants and children in four age groups were enrolled in the study: 2 to 5 months, 6 to 23 months, 2 to 5 years, and 6 to 12 years. The first patients enrolled were those in the oldest age group, who received the lowest dose. Subsequent enrollment was determined by decreasing age and increasing dose. Complete studies were performed on 63 patients. No age- or dose-dependent effects on pharmacokinetic parameter estimates were noted. Mean pharmacokinetic parameter estimates were as follows: half-life, 1.13 +/- 0.15 h; volume of distribution at steady state, 0.43 +/- 0.06 liters/kg; mean residence time, 1.57 +/- 0.11 h; clearance, 5.63 +/- 0.75 ml/min/kg; and renal clearance, 2.53 +/- 0.50 ml/min/liters kg. Approximately 55% of the administered dose was recovered as unchanged drug in the urine during the 12 h after dosing. No significant side effects were reported in any patients. By using the derived pharmacokinetic parameter estimates, a dose of 20 mg/kg given every 8 h will maintain plasma meropenem concentrations above the MIC that inhibits 90% of strains tested for virtually all potentially susceptible bacterial pathogens.

Aging↗
PubMed1995

A recent measles outbreak in Arkansas.

On a worldwide level, measles is a common infection, especially in developing countries. In the United States, however, the disease has become very uncommon secondary to the widespread use of immunizations. Because of this, many physicians have not had measles themselves, nor have they treated patients for the infection. This relative rarity may delay diagnosis and the institution of appropriate infection control measures, thus resulting in increased numbers of exposed persons. Until measles is eradicated, measures to ensure appropriate immunization and control outbreaks are essential. A recent small outbreak in Arkansas is reported here along with a review of the disease and the measures to control outbreaks.

Adult↗
PubMed1994

Effective short-course treatment of acute group A beta-hemolytic streptococcal tonsillopharyngitis. Ten days of penicillin V vs 5 days or 10 days of cefpodoxime therapy in children.

OBJECTIVE: To compare bacteriologic and clinical efficacy and safety of 10 vs 5 days of cefpodoxime proxetil vs 10 days of penicillin V potassium for the treatment of acute group A beta-hemolytic streptococcal tonsillopharyngitis in children. DESIGN: Prospective, randomized, observer-blind, multicenter study. PATIENTS/INTERVENTIONS: Four hundred eighty-four children (age range, 2 to 17 years) with signs and symptoms of acute tonsillopharyngitis were enrolled; 377 had a positive throat culture for group A beta-hemolytic streptococci and were fully evaluable. One hundred twenty-one patients received cefpodoxime once a day for 10 days, 126 received cefpodoxime twice a day for 5 days, and 130 received penicillin V three times a day for 10 days. RESULTS: Cefpodoxime for 10 days vs cefpodoxime for 5 days vs penicillin V for 10 days produced bacteriologic eradication at the end of therapy in 95%, 90%, and 78% of the patients, respectively. The 10- and 5-day cefpodoxime treatment regimens were more efficacious than penicillin V (P = .003 and P = .02, respectively). The cumulative bacteriologic failure rate among assessable patients by the 32- to 38-day posttreatment visit was 20 (17%) of 121 patients who were treated with cefpodoxime for 10 days, 24 (19%) of 125 patients who were treated with cefpodoxime for 5 days, and 45 (35%) of 130 patients who were treated with penicillin V for 10 days (P = .001 and P = .005, respectively). Clinical cure or improvement was observed at the end of therapy in 96%, 94%, and 91% of the patients, respectively (P = not significant). Adverse events were infrequent and similar in all three treatment groups, with minor gastrointestinal side effects predominating. CONCLUSIONS: Five days of treatment with cefpodoxime is as efficacious in bacteriologic eradication and clinical response (cure plus improvement) as 10 days of cefpodoxime therapy, and both cefpodoxime regimens produced superior bacteriologic efficacy compared with a 10-day regimen of penicillin V in the treatment of group A beta-hemolytic streptococcal tonsillopharyngitis in children.

Acute Disease↗
PubMed1994

Streptomycin and alternative agents for the treatment of tularemia: review of the literature.

Because of the recent lack of availability of streptomycin--currently considered the drug of choice for the treatment of tularemia--we reviewed the literature on alternative drugs that have been used for this purpose. In addition, we reviewed data on the in vitro susceptibility of Francisella tularensis to a wide variety of agents. The rate of cure for streptomycin was 97%, with no relapses. For gentamicin and tetracycline, respectively, the rates of cure were 86% and 88%, the rates of relapse were 6% and 12%, and the rates of failure were 8% and 0. The duration of therapy with gentamicin and a delay in its initiation may have affected outcome in severe cases. For chloramphenicol and tobramycin, cure rates were 77% and 50%, respectively; relapse rates were 21% and 0; and failure rates were 2% and 33%, respectively. Treatment with imipenem/cilastatin was successful in one case, and that with ciprofloxacin or norfloxacin was successful in six cases; in contrast, therapy with ceftriaxone was ineffective in eight cases. On the basis of this review, we conclude that gentamicin is an acceptable alternative to streptomycin for the treatment of tularemia.

Francisella tularensis↗
PubMed1994

Treatment of tuberculosis and tuberculosis infection in adults and children. American Thoracic Society and The Centers for Disease Control and Prevention.

Treatment of Tuberculosis. 1. A 6-mo regimen consisting of isoniazid, rifampin, and pyrazinamide given for 2 mo followed by isoniazid and rifampin for 4 mo is the preferred treatment for patients with fully susceptible organisms who adhere to treatment. Ethambutol (or streptomycin in children too young to be monitored for visual acuity) should be included in the initial regimen until the results of drug susceptibility studies are available, unless there is little possibility of drug resistance (i.e., there is less than 4% primary resistance to isoniazid in the community, and the patient has had no previous treatment with antituberculosis medications, is not from a country with a high prevalence of drug resistance, and has no known exposure to a drug-resistant case). This four-drug, 6-mo regimen is effective even when the infecting organism is resistant to INH. This recommendation applies to both HIV-infected and uninfected persons. However, in the presence of HIV infection it is critically important to assess the clinical and bacteriologic response. If there is evidence of a slow or suboptimal response, therapy should be prolonged as judged on a case by case basis. 2. Alternatively, a 9-mo regimen of isoniazid and rifampin is acceptable for persons who cannot or should not take pyrazinamide. Ethambutol (or streptomycin in children too young to be monitored for visual acuity) should also be included until the results of drug susceptibility studies are available, unless there is little possibility of drug resistance (see Section 1 above). If INH resistance is demonstrated, rifampin and ethambutol should be continued for a minimum of 12 mo. 3. Consideration should be given to treating all patients with directly observed therapy (DOT). 4. Multiple-drug-resistant tuberculosis (i.e., resistance to at least isoniazid and rifampin) presents difficult treatment problems. Treatment must be individualized and based on susceptibility studies. In such cases, consultation with an expert in tuberculosis is recommended. 5. Children should be managed in essentially the same ways as adults using appropriately adjusted doses of the drugs. This document addresses specific important differences between the management of adults and children. 6. Extrapulmonary tuberculosis should be managed according to the principles and with the drug regimens outlined for pulmonary tuberculosis, except for children who have miliary tuberculosis, bone/joint tuberculosis, or tuberculous meningitis who should receive a minimum of 12 mo of therapy.(ABSTRACT TRUNCATED AT 400 WORDS)

Adolescent↗
PubMed1994

Intravenous immunoglobulin modulates human mononuclear phagocyte tumor necrosis factor-alpha production in vitro.

Mononuclear phagocytes (MO) secrete tumor necrosis factor-alpha (TNF) in response to inflammatory stimuli, most notably the bacterial product lipopolysaccharide (LPS). Cross-linking of MO Fc receptors also induces TNF release. Immunoglobulin for i.v. use is currently being investigated for the treatment and prophylaxis of neonatal sepsis and for the treatment of various syndromes of autoimmune dysfunction in children and adults. We examined the in vitro effect of immunoglobulin-gamma (IgG) on neonatal (cord blood) monocyte and adult MO TNF production. Kinetic studies were performed on MO incubated with IgG alone and on MO preincubated with IgG and stimulated with interferon-gamma/LPS. Incubation of MO in IgG (1-25 g/L) for 2, 6, and 24 h did not stimulate TNF secretion or production. However, enhanced TNF secretion was detected in MO preincubated in IgG and subsequently stimulated with interferon-gamma/LPS. TNF secretion by cord blood monocytes was increasingly enhanced by preincubation for 6 h with 1, 10, and 25 g/L IgG (2413.1 +/- 1389.4, p < 0.05; 4070.4 +/- 3069.2, p < 0.005; and 6383.7 +/- 2982.2, p < 0.005 versus 1215 +/- 575.9 ng/L, respectively, in cells preincubated in medium alone). Significant enhancement was also detected in cord blood monocytes preincubated in IgG for 2 h. TNF secretion by adult MO was similarly enhanced (6082.0 +/- 1732.8, p < 0.05; 7158.8 +/- 3938.2, p < 0.05; and 7302.7 +/- 3451.4, p < 0.05 versus 3353.2 +/- 2946.7 ng/L for 1, 10, and 25 g/L IgG, respectively, versus preincubation in medium alone). In additional experiments performed with Fc, Fab, and F(ab')2 fragments, only F(ab')2 fragments yielded positive results.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

Single-dose pharmacokinetics and safety of HA-1A, a human IgM anti-lipid-A monoclonal antibody, in pediatric patients with sepsis syndrome.

The pharmacokinetics and safety of HA-1A (Nebacumab), a human IgM monoclonal antibody with specificity for the lipid A region of endotoxin, were evaluated in a multicenter trial of pediatric patients with sepsis syndrome or septic shock. Forty-two patients received a total of 44 infusions of drug, at a dose of 3 mg/kg (maximum 100 mg). The mean age was 7 years 10 months (range, 11 months to 16 years 7 months). The pharmacokinetic behavior of HA-1A during 36 hours was best described by a one-compartment open model. Clearance (6.1 +/- 2.0 ml/kg per hour) and apparent volume of distribution at steady state (0.11 +/- 0.03 L/kg) were larger than values reported previously in adults with sepsis syndrome. Elimination half-life (14.5 +/- 6.8 hours) and plasma concentration after infusion (30.7 +/- 14.5 mg/L) were similar to adults' values. In an additional three patients studied for 72 hours after administration, a biexponential function (i.e., two-compartment open model) best described the pharmacokinetic behavior of HA-1A: clearance (1.5 +/- 1.4 ml/hr per kilogram) and apparent volume of distribution at steady state (0.2 +/- 0.02 L/kg) were different (p < 0.002) from values observed in children's blood samples during 36 hours. Within the pediatric population, no age-related differences in pharmacokinetics could be detected. Drug disposition was unaffected by renal or hepatic dysfunction. Decreased blood pressure was the most frequently reported adverse event; 4 (9%) episodes in 44 infusions were considered possibly related to the study drug. Gram-negative bacteremia was documented in 23 (55%) of 42 patients. The overall mortality rate was 31%. Enterobacter cloacae was the most common pathogen isolated. Haemophilus influenzae type b was isolated from one child with sepsis syndrome. We conclude that infusion of HA-1A in children is associated with a low incidence of side effects. The pharmacokinetic-pharmacodynamic behavior of HA-1A in children requires further study to determine whether developmental differences exist and how these differences might affect drug administration. Efficacy remains to be studied.

Adolescent↗