Anti-interleukin-6 antibodies attenuate inflammation in a rat meningitis model.

OBJECTIVES: Interleukin-6 (IL-6) is elevated in the cerebrospinal fluid (CSF) of humans and animals with bacterial meningitis. This study's hypothesis was that anti-IL-6 antibodies will attenuate meningeal inflammation in a rat model of bacterial meningitis. METHODS: 14 male Sprague-Dawley rats were inoculated intracisternally (IC) with 0.1 mL of heat-killed pneumococci. At one hour post-inoculation, the rats received intraperitoneal doses of either 1.0 mL phosphate-buffered saline (PBS treatment group, n = 7) or 70 microg anti-IL-6 antibodies in 1.0 mL PBS (anti-IL-6 antibody treatment group, n = 7). Nine rats (normal group, n = 9) had no inoculation, and four rats (surgical sham group, n = 4) had IC inoculations of saline. At six hours post-inoculation, all the animals had CSF removed via IC tap. The CSF protein and white blood cell (WBC) count measures were compared using a t-test. RESULTS: Mean CSF WBC for the anti-IL-6 treatment group was 2,458/microL, versus the PBS controls' mean of 9,697/microL (p = 0.007). Mean CSF protein for the anti-IL-6 group was 180 mg/dL, versus 296 mg/dL for the controls (p = 0.032). The surgical sham and normal animals had normal CSF WBC and protein values. CONCLUSIONS: In this rat meningitis model, systemic treatment with anti-IL-6 antibodies after the induction of meningitis suppressed both CSF WBC count and CSF protein level, two important indices of meningeal inflammation.

Transient synovitis: lack of serologic evidence for acute parvovirus B-19 or human herpesvirus-6 infection.

We evaluated children with transient synovitis for serologic evidence of infection with parvovirus B-19 (PVB-19) and human herpesvirus-6 (HHV-6) by using a prospective patient series in an urban children's hospital emergency department (ED). There were 20 children enrolled, aged 15 months to 6 years, diagnosed with transient synovitis. Clinical data were collected, and acute PVB-19 and HHV-6 immunoglobulin G (IgG) and IgM serologic titers were measured on all patients. Ten patients returned in 4-6 weeks for convalescent titers. The mean age was 4.1 years. Prodromal symptoms within a week of presentation were noted in 50% of patients, most commonly fever (25%) and upper respiratory infection (20%). Mean sedimentation rate was 11 mm/h (range, 2-22 mm/h), and mean peripheral white blood count was 11,000/microl (range, 6-21,000/ microl). No patient had increased acute or convalescent IgM titers for either PVB-19 or HHV-6, and no patient who returned for follow-up had an increase in serum IgG titers for either virus. A majority of patients (80%) had increased acute HHV-6 IgG titers, reflecting prior immunity to this virus. In conclusion, there is no evidence in this series that acute infection with PVB- 19 or HHV-6 causes or precedes transient synovitis.

Use of sodium polystyrene sulfonate for reduction of plasma lithium concentrations after chronic lithium dosing in mice.

OBJECTIVES: Previous studies have shown that oral sodium polystyrene sulfonate lowers plasma lithium concentrations after acutely administered oral doses of lithium chloride. However, a significant proportion of lithium overdose cases resulting in morbidity and mortality are those in which exposure to lithium is chronic. This study was designed to determine whether multiple oral doses of sodium polystyrene sulfonate are effective in reducing plasma lithium concentrations after chronic dosing. DESIGN: Placebo-controlled animal study. INTERVENTIONS: One hundred thirty mice were given 75 mM lithium chloride in their drinking water for a period of 14 days. At the end of that period, half of the animals were given orogastric sodium polystyrene sulfonate at 5 g/kg/dose 0, 60, 120, 180, and 360 minutes after the cessation of lithium chloride; the remaining half received orogastric water at equivalent times. Subgroups of each group were sacrificed at 90, 150, 330, 480, 1440, and 2880 minutes after lithium chloride cessation and plasma analyzed for lithium content. Lithium concentrations were compared by analysis of variance and single degree of freedom contrasts. Significance was set at an alpha level of 0.05. RESULTS: Lithium concentration was lower overall in the animals treated with sodium polystyrene sulfonate (p < .0001) and specifically at 150, 330, and 480 minutes after lithium chloride cessation (p < .05). CONCLUSIONS: Repetitive oral doses of sodium polystyrene sulfonate effectively lowered plasma lithium concentrations. Further study may ultimately define a role for the use of sodium polystyrene sulfonate in the treatment of patients with chronic lithium toxicity.

Enhancement of lithium elimination by multiple-dose sodium polystyrene sulfonate.

OBJECTIVE: To determine whether multiple doses of sodium polystyrene sulfonate (SPS) enhance the elimination of IV-administered lithium (Li). METHODS: The study was a placebo-controlled, investigator-unblinded, murine trial of multiple doses of SPS on serum Li concentrations. Seventy-five male CD-1 mice were given IV pretreatment with LiCl (125 mg/ kg) followed by gavage treatments with SPS (5 g/kg/dose) 20, 40, 90, 150, and 210 minutes after LiCl (experimental group) or deionized water at equivalent times (control group). Subgroups of each treatment group were sacrificed at 1, 2, 4, and 6 hours after LiCl administration and blood was collected for Li analysis. RESULTS: Statistical analyses indicated that the SPS group had lower serum Li concentrations overall than did the control animals. This difference was apparent at the 2-, 4-, and 6-hour time points. CONCLUSION: In this murine model, repetitive doses of orogastric SPS enhanced the elimination of parenterally administered Li.

Sodium polystyrene sulfonate treatment for lithium toxicity: effects on serum potassium concentrations.

OBJECTIVE: To examine the effects of sodium polystyrene sulfonate (SPS) on serum potassium (K) concentrations in mice pretreated with parenteral lithium (Li). METHODS: A placebo-controlled murine model trial of SPS therapy following IV Li was performed. Sixty male CD-1 mice weighing 18-22 g were administered either IV LiCl (125 mg/kg) or a control solution (normal saline). Half of the mice in each of these groups were then given orogastric water 20, 40, 90, 150, and 210 minutes after LiCl or normal saline; the other half received SPS (5 g/kg/dose) at equivalent times. Subgroups of each of these four groups were sacrificed at one, two, and six hours after pretreatment and the serum was analyzed for K concentration. Serum K concentrations for the various groups were compared with analysis of variance and Newman-Keuls tests for the comparison of multiple means. RESULTS: A statistically significant reduction of serum K concentrations occurred in the animals that received SPS treatment following either IV saline or LiCl solutions. The degree of K reduction that resulted from the combination of LiCl and SPS treatment (35% reduction at six hours, compared with the placebo-treated controls) was larger than that which resulted from either IV Li with oral water (15% reduction) or IV saline with oral SPS (20% reduction). CONCLUSIONS: These findings suggest that development of hypokalemia may represent a potential limitation in the use of SPS in the treatment for Li toxicity.

Use of urinary gram stain for detection of urinary tract infection in infants.

STUDY OBJECTIVE: To determine whether Gram stain of urine is more sensitive than urinalysis in detecting urinary tract infection in infants. DESIGN: Prospective series. SETTING: Urban teaching hospital emergency department. PARTICIPANTS: Two hundred seven infants 6 months old or less, from whom a catheterized or suprapubically aspirated urine specimen was obtained for culture. INTERVENTIONS: Urinary Gram stain, culture, and urinalysis were performed. With culture results as the validating standard, the Gram stain sensitivity, specificity, and predictive values were compared with urinalysis, including leukocyte esterase, nitrite, pyuria, and bacteriuria. RESULTS: The prevalence of positive cultures was 8.7% (18 of 207). Gram stain had higher sensitivity than overall urinalysis (94% versus 67%, P < .05), higher specificity (92% versus 79%, P < .05), and higher positive predictive value (53% versus 23%, P < .05). CONCLUSION: Urinary Gram stain appears to be more reliable than urinalysis in detecting urinary tract infection in young infants.