Richard A. Saladino

Intranasal Immunization with Killed Unencapsulated Whole Cells Prevents Colonization and Invasive Disease by Capsulated Pneumococci

ABSTRACT A whole-cell killed unencapsulated pneumococcal vaccine given by the intranasal route with cholera toxin as an adjuvant was tested in two animal models. This vaccination was highly effective in preventing nasopharyngeal colonization with an encapsulated serotype 6B strain in mice and also conferred protection against illness and death in rats inoculated intrathoracically with a highly encapsulated serotype 3 strain. When the serotype 3 challenge strain was incubated in the sera of immunized rats, it was no longer virulent in an infant-rat sepsis model, indicating that the intranasal immunization elicited protective systemic antibodies. These studies suggest that killed whole-cell unencapsulated pneumococci given intranasally with an adjuvant may provide multitypic protection against capsulated pneumococci.

Heterotrimeric G proteins physically associated with the lipopolysaccharide receptor CD14 modulate both in vivo and in vitro responses to lipopolysaccharide.

Septic shock induced by lipopolysaccharide (LPS) triggering of cytokine production from monocytes/macrophages is a major cause of morbidity and mortality. The major monocyte/macrophage LPS receptor is the glycosylphosphatidylinositol (GPI)-anchored glycoprotein CD14. Here we demonstrate that CD14 coimmunoprecipitates with Gi/Go heterotrimeric G proteins. Furthermore, we demonstrate that heterotrimeric G proteins specifically regulate CD14-mediated, LPS-induced mitogen-activated protein kinase (MAPK) activation and cytokine production in normal human monocytes and cultured cells. We report here that a G protein binding peptide protects rats from LPS-induced mortality, suggesting a functional linkage between a GPI-anchored receptor and the intracellular signaling molecules with which it is physically associated.

The role of heparin in the prevention of extremity and digit necrosis in meningococcal purpura fulminans.

In order to gather data regarding the utility of heparin therapy in limiting digit and extremity necrosis resulting from meningococcal purpura fulminans in children, we reviewed the charts of 24 pediatric patients with PF associated with meningococcal disease. Our study population was comprised of the 13 patients who survived more than 2 days. Clinical and outcome data were compared between the group of patients who received therapeutic heparin treatment in the initial 72 hours (≥50 units/kg bolus followed by an infusion, three patients) and the group who did not (10 patients). Demographic and initial clinical and laboratory findings were similar between groups (P > 0.15). When the two groups were compared for dermatologic and orthopedic sequelae, the mean number of digits (6.3 vs. 11.1; P = 0.35) and extremities (1.7 vs. 3.0; P = 0.17) with necrosis was less in those patients who received therapeutic doses of heparin, although the differences were not statistically significant. When only those patients on whom diffuse purpura were noted on admission were compared, these differences were greater. This small, retrospective series suggests that heparin therapy may limit digit and extremity necrosis when used early and in therapeutic doses in meningococcal purpura fulminans. Therefore, a larger, prospective controlled trial is warranted.

Pediatric facial fractures: demographics, injury patterns, and associated injuries in 772 consecutive patients.

Background: Pediatric craniofacial fractures are anatomically distinct from their adult counterparts and must be managed with respect for future growth and development. These injuries must be approached as entities fundamentally different from adult craniofacial fractures. Here, the authors aim to provide context for practitioners managing pediatric facial fractures by augmenting presently available demographic, diagnostic, and treatment data. Methods: This is a retrospective review of demographics, diagnosis, and treatment of patients under 18 years of age presenting to the emergency department of a pediatric level I trauma center between 2000 and 2005 with facial fractures. Patients were included regardless of treating specialty, treatment modality, or inpatient status. Results: A total of 772 consecutive patients met inclusion criteria. A significant majority (p < 0.001) of patients (68.9 percent) were male; older children were significantly more likely to sustain a facial fracture (p < 0.001). Fracture pattern, level of care, and cause of injury varied by age; 55.6 percent of patients had severe associated injuries. Male subjects, older patients, and patients of lower socioeconomic status were significantly more likely to sustain facial fractures secondary to violence (p ⩽ 0.001). Conclusions: Pediatric facial fractures may be associated with severe concomitant injuries. Injury patterns are significantly correlated with socioeconomic metrics. CLINICAL QUESTION/LEVEL OF EVIDENCE: Risk, IV.

Anticapsular Polysaccharide Antibodies and Nasopharyngeal Colonization with Streptococcus pneumoniae in Infant Rats

To evaluate the effect of passive immunization with anticapsular antibodies on nasopharyngeal carriage, two models of Streptococcus pneumoniae colonization were developed in infant rats. In a direct inoculation model, 3- to 4-day-old infant rats were intranasally inoculated with 2 x 10(5) cfu of S. pneumoniae type 3 or 6 x 10(3) cfu of S. pneumoniae type 23F. In an intralitter transmission model, 2 infant rats were intranasally inoculated with 10(3) cfu of pneumococcus type 3 or type 19F and placed in a cage containing 10 infant rats. Pretreatment with bacterial polysaccharide immune globulin led to a significant reduction in colonization of contact animals with S. pneumoniae type 3 or 19F in the intralitter transmission model (P < .05). No effect of immune globulin could be demonstrated in the direct inoculation model. These results indicate that systemic anticapsular antibodies conferred significant protection against nasopharyngeal acquisition by intralitter spread of S. pneumoniae type 3 and 19F.

Activated protein C concentrate for the treatment of meningococcal endotoxin shock in rabbits

To evaluate the effects of activated protein C therapy in a rabbit model of meningococcal endotoxin-induced shock, we performed a prospective, blinded, placebo-controlled animal trial. Forty New Zealand White rabbits were challenged with intravenous meningococcal endotoxin (lipooligosaccharide) 100 μg/kg. Ten minutes before endotoxin challenge, animals were administered either activated protein C 1600 μg/mL (n = 20) or an equal volume of saline (n = 20) as an initial bolus. After endotoxin challenge, activated protein C treated animals were administered a continuous infusion of activated protein C 160 μg/kg/h and saline-treated animals were administered an equal volume infusion of saline. Both activated protein C treated and saline control animals demonstrated evidence of shock after endotoxin challenge; mean arterial pressure and serum bicarbonate significantly (p < .01) declined, and heart rate significantly (p < .01) increased from baseline. In activated protein C treated animals, mean plasma activated protein C activity was 5.69 μg/mL (± 3.2) 1 h after challenge, whereas plasma protein C activity was not detected in controls. Mean prothrombin and activated partial thromboplastin times were significantly (p ± .01) prolonged compared with saline-treated controls. Other hematologic and chemical measurements did not differ between groups. Fifteen of 20 (75%) animals treated with activated protein C concentrate survived to 24 h, while 9 of 20 (45%) control animals survived to 24 h (p = .05). Those animals treated with activated protein C had improved survival, which corroborates the findings of early clinical studies in which replacement of protein C improved outcome.

Identifying Neurocognitive Deficits in Adolescents Following Concussion

OBJECTIVES This study of concussed adolescents sought to determine if a computer-based neurocognitive assessment (Immediate Postconcussion Assessment and Cognitive Test [ImPACT]) performed on patients who present to the emergency department (ED) immediately following head injury would correlate with assessments performed 3 to 10 days postinjury and if ED neurocognitive testing would detect differences in concussion severity that clinical grading scales could not. METHODS A prospective cohort sample of patients 11 to 17 years of age presenting to the ED within 12 hours of a head injury were evaluated using two traditional concussion grading scales and neurocognitive testing. ED neurocognitive scores were compared to follow-up scores obtained at least 3 days postinjury. Postconcussive symptoms, outcomes, and complications were assessed via telephone follow-up for all subjects. RESULTS Sixty patients completed phone follow-up. Thirty-six patients (60%) completed follow-up testing a median of 6 days postinjury. Traditional concussion grading did not correlate with neurocognitive deficits detected in the ED or at follow-up. For the neurocognitive domains of verbal memory, processing speed, and reaction time, there was a significant correlation between ED and follow-up scores trending toward clinical improvement. By 2 weeks postinjury, 23 patients (41%) had not returned to normal activity. At 6 weeks, six patients (10%) still had not returned to normal activity. CONCLUSIONS Immediate assessment in the ED can predict neurocognitive deficits seen in follow-up and may be potentially useful to individualize management or test therapeutic interventions. Neurocognitive assessment in the ED detected deficits that clinical grading could not and correlated with deficits at follow-up.

Minimum Protective Serum Concentrations of Pneumococcal Anti-Capsular Antibodies in Infant Rats

Infant rats were passively immunized to determine the protective capacity of pneumococcal anticapsular antibodies. Animal-passaged strains of Streptococcus pneumoniae serotypes 1, 4, 5, 6b, 7f, 9v, 14, 18c, 19f, and 23f were used as challenge inocula (1-1500 cfu) in a model of pulmonary infection that resulted in bacteremia, meningitis, and death. From untreated control animals, histologic sections of lung demonstrated infiltrative pneumonia and lung homogenate cultures grew S. pneumoniae at concentrations of 10(3)-10(8) cfu per gram of lung tissue. A type-specific anti-capsular antibody serum concentration of 0.1-1.15 microg/mL resulted in a statistically significant reduction in mortality compared with the reduction in untreated controls, except for serotype 14, which required 2.32 microg/mL for a significant reduction in mortality. The serum antibody level that provided 50% reduction in mortality ranged from 0.1-3.5 microg/mL for all serotypes.

The spectrum of liver and spleen injuries in children: Failure of the pediatric trauma score and clinical signs to predict isolated injuries

STUDY OBJECTIVES To determine whether potentially life-threatening intra-abdominal injuries occur in the absence of multisystem trauma in children, and to determine the usefulness of physical examination and a pediatric triage score in the assessment of liver and spleen injuries in children. DESIGN Retrospective study. SETTING Admissions to a childrens hospital from October 1982 through September 1989 who were found to have liver or spleen injuries. Seventy-seven patients were identified; 55 were male, 22 were female. Mean age was 9 years and 3 months (+/- 56 months) with a range of 22 months to 20 years, 4 months. Clinical signs were recorded and a Pediatric Trauma Score (PTS) and Injury Severity Score (ISS) were calculated for each patient. MEASUREMENTS AND MAIN RESULTS Fifty-four patients (70%) had a spleen injury, 18 (23%) had a liver injury, and five (7%) had both liver and spleen injuries. Patients were managed without surgery in 63 of 77 cases (82%); two died. Fifty-one of 77 patients (66%) received an ISS of 18 or less; 26 patients (34%) received a score of more than 18. Forty-four of the 51 patients (86%) with an ISS of 18 or less had a normal pulse (120 or less); 48 of the 51 (94%) had a normal systolic blood pressure (90 mm Hg or more). A strong negative correlation (r = -0.80; P = .001) was found between the two scores for children with multiple severe injuries (ISS of more than 18); there was poor correlation (r = -0.04; P greater than .05) between the two scores for isolated liver or spleen injury (ISS of 18 or less). CONCLUSIONS We conclude that liver or spleen damage may be present in children without other injuries and must be considered with a high index of suspicion, and that neither the initial clinical findings nor the PTS reliably predicts liver or spleen injuries in children with focal abdominal injuries.

Failure of prophylactic and therapeutic use of a murine anti-tumor necrosis factor monoclonal antibody in Escherichia coli sepsis in the rabbit.

OBJECTIVE To determine the efficacy of a murine anti-tumor necrosis factor (TNF) monoclonal antibody in the treatment of Escherichia coli peritonitis and sepsis in the rabbit. DESIGN Prospective, paired, randomized, blinded, controlled animal trial. SETTING Animal research laboratory. SUBJECTS Male New Zealand white rabbits. INTERVENTIONS Anesthetized rabbits were cannulated with indwelling femoral arterial and venous catheters. Peritonitis and sepsis were induced by intraperitoneal challenge using live E. coli O18ac bacteria. All animals were treated with gentamicin and ceftriaxone 1 hr after challenge. One group (prophylaxis experiment) consisting of ten rabbit pairs (the prophylaxis group), was treated with either murine anti-TNF monoclonal antibody or an equivalent volume of 5% albumin 3 hrs before E. coli challenge. A second group (therapeutic experiment) of 17 rabbit pairs, the treatment group, was also treated with murine anti-TNF monoclonal antibody or albumin control 1 hr after E. coli challenge. MEASUREMENTS AND MAIN RESULTS All animals were bacteremic 1 hr after challenge. Physiologic measures of sepsis (heart rate, mean arterial pressure, serum bicarbonate, and arterial pH) did not differ between control, prophylaxis, and treatment groups. Peak serum TNF concentration was significantly (p < .01) lower in animals receiving anti-TNF monoclonal antibody, in both the prophylaxis and treatment groups, than in control animals. The survival rate was not improved significantly in either the prophylaxis or treatment group. CONCLUSIONS Prophylactic and therapeutic use of anti-TNF monoclonal antibody in a rabbit model of E. coli peritonitis and sepsis significantly lowers TNF concentrations but does not ameliorate the physiologic effects of sepsis and does not significantly improve survival.