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Biomedical subjects

L G Rubin

Publications and source records attributed to L G Rubin.

At least 55 records · Page 3Linked to original sources
PubMed1989

An infant rat model of bacteremia with Brazilian purpuric fever isolates of Hemophilus influenzae biogroup aegyptius. Brazilian Purpuric Fever Study Group.

Brazilian purpuric fever (BPF) is a newly recognized fulminant pediatric infection caused by bacteremia with Hemophilus influenzae biogroup aegyptius (Hae). Following intraperitoneal inoculation, each of five disease isolates caused bacteremia more frequently than control, conjunctival isolates of Hae in complement-depleted 6-d-old rats. Sustained but self-limited bacteremia was observed in normal infant rats after inoculation with a disease strain. These rats developed meningitis and had depressed hemoglobin concentration and platelet counts. Pathologic examination showed meningitis and contiguous otitis. Pretreatment of infant rats with immune adult rat serum raised against disease isolates protected rats from bacteremia. Normal adult rat serum or immune rat serum against control strains failed to protect infant rats. Thus, strains of Hae isolated from patients with BPF are more virulent than control strains. Antibody against antigens unique to disease isolates protects infant rats from bacteremia.

Animals↗
PubMed1989

Eyelid swelling and erythema as the only signs of subperiosteal abscess.

On clinical grounds it is usually easy to distinguish between preseptal cellulitis, a cutaneous infection not threatening to vision, and orbital cellulitis, a potentially vision threatening infection of the orbital tissues generally arising from paranasal sinusitis. We recently cared for two patients with a clinical diagnosis of preseptal cellulitis who had CT scan evidence of subperiosteal abscess. Antibiotic therapy alone resulted in clinical resolution in each case.

Abscess↗
PubMed1989

Immunization of children with sickle cell disease with Haemophilus influenzae type b polysaccharide vaccine.

There are limited data concerning safety and immunogenicity of Haemophilus influenzae type b polysaccharide vaccine in children with sickle cell disease. Ninety-eight patients with sickle cell disease (65 with SS phenotype, 23 with SC phenotype, and 10 with S beta-thalassemia) 1.5 to 20 years of age were given 25 micrograms of vaccine subcutaneously. The vaccine was well tolerated; mild side effects were observed in 6 of 98 (6.1%) children. In addition, one patient with a recent vasoocclusive crisis was hospitalized because of fever and vasoocclusive crisis 8 hours after vaccination. Prevaccination anticapsular antibody concentrations (by radioimmunoassay) were less than 0.15 microgram/mL in 7 of 11 children 18 to 24 months of age (geometric mean 0.17 microgram/mL), in 10 of 25 children 2 to 5 years of age (geometric mean 0.36 microgram/mL), and in 3 of 50 patients 6 to 20 years of age (geometric mean 1.03 microgram/mL). Inadequate response (1- to 2-month postvaccination antibody level less than 1 microgram/mL) was found in 3 of 5 children 18 to 24 months of age (geometric mean 1.74 microgram/mL), in 8 of 21 children 2 to 5 years of age (geometric mean 2.20 micrograms/mL), and in 2 of 49 patients 6 to 20 years of age (geometric mean 18.03 micrograms/mL). Six months after vaccination, greater than 1 microgram/mL of antibody was present in the 2 children 6 to 20 years of age with inadequate response but not in the 7 children 2 to 5 years of age with inadequate response.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1988

Infection rates of Broviac-Hickman catheters and implantable venous devices.

We retrospectively identified and prospectively followed up 62 patients with 78 venous-access catheters over a 30-month period (15773 catheter-days) to compare infectious complications of Broviac-Hickman catheters (n = 33) and totally implantable. venous devices (n = 45) in pediatric oncology patients. Demographic data and characteristics of catheter use were comparable for both groups. Significantly associated with the risk of a catheter-associated infection were (1) the percentage of time the patient was neutropenic and (2) a patient age of younger than 2 years. In the Broviac-Hickman catheter group, 14 catheter-associated infections occurred in 27% of patients using catheters for an infection rate of 0.21/100 catheter-days. In the implantable venous device group, 13 infections occurred in 24% of patients using catheters for an infection rate of 0.14/100 catheter-days. The relative risk of infection from Broviac-Hickman catheters compared with implantable venous devices was 1.5, which was not significant (95% confidence interval, 0.7 to 3.2). Thus, the incidence of infectious complications was comparable for both catheter types.

Cardiac Catheterization↗
PubMed1988

Anticapsular antibody requirements for protection against experimental Haemophilus influenzae type b bacteremia after splenectomy.

Although asplenic individuals are at higher risk for infection with encapsulated bacteria, it is not known whether they require a higher concentration of anticapsular antibody than normal individuals do for protection against invasive disease caused by Haemophilus influenzae type b. At 21 days of age, rats were passively immunized with human hyperimmune serum globulin against H. influenzae b polysaccharide (or saline) after recovery from splenectomy or a sham operation. Starting at 18 h after immunization, rats received three intranasal inoculations of 10(7) CFU of H. influenzae b over the next 24 h. Of sham-operated rats given 0.75 or 3.0 micrograms of anticapsular antibody, 91 or 96%, respectively, were protected from bacteremia, whereas only 59 and 67% of similarly treated asplenic rats were protected (P less than 0.004, control versus asplenic rats). A 12-microgram antibody dose resulted in the complete protection of both groups. The magnitude of bacteria was significantly higher in the asplenic group at each dose of antibody. Thus, asplenic hosts may require a higher concentration of anticapsular antibody than normal individuals do for protection against invasive H. influenzae b disease.

Animals↗
PubMed1988

Clinical laboratory challenges in the recognition of Leuconostoc spp.

Vancomycin-resistant Streptococcus salivarius-like bacteria were isolated from the blood and gastrostomy tube of a 6-month-old child during vancomycin therapy for Staphylococcus epidermidis central venous catheter-associated bacteremia. The isolates produced D-(-)-lactate and ethanol from glucose, hydrolyzed esculin, and produced no ammonia from arginine, thus fulfilling the major criteria as Leuconostoc spp. The enzymatic profile of the bacteria suggested that they were not lactobacilli or streptococci. Resistance to vancomycin and penicillin tolerance were noted. The formula fed through the gastrostomy tube was suspected as the vehicle that transmitted the organism to the patient. Penicillin and tobramycin therapy was used successfully.

Catheterization, Central Venous↗
PubMed1988

Plasma fibronectin concentrations in breast fed and formula fed neonates.

Plasma fibronectin concentration was measured in neonates of 2 to 5 days of age. Although breast fed and formula fed infants were similar in demographic characteristics, the mean (SD) plasma concentration of fibronectin in 26 breast fed infants, 237 (117) mg/l, was significantly higher than in 27 formula fed infants (171 (91) mg/l). Fibronectin was detected in five colostrum specimens (mean concentration 13.4 mg/l). Similar bands were detected after gel electrophoresis of purified adult plasma fibronectin and whole plasma from breast fed and formula fed neonates after staining or immunoblotting. Fibronectin isolated from breast milk also appeared similar to purified plasma fibronectin. It is possible, although unlikely, that fibronectin is absorbed intact from ingested colostrum. Alternatively, a factor(s) might be present in colostrum that contributes to the regulation of plasma fibronectin concentration.

Bottle Feeding↗
PubMed1987

Varicella zoster immunoglobulin after postnatal exposure to varicella: survey of experts.

A questionnaire based on a hypothetical 6-day-old infant exposed to a sibling with varicella was mailed to 316 Pediatric Infectious Diseases Society members to determine their recommendations for administration of varicella zoster immunoglobulin (VZIG). Of the 137 faculty members who responded 20% would recommend VZIG for the infant described (13% were undecided). When further information including a negative maternal history for varicella, prematurity or maternal varicella infection occurring 1 week after delivery was considered, the numbers who recommended VZIG (43, 46 and 52%, respectively) rose significantly (P less than 0.01). Twenty-two physicians had knowledge of a severe case of varicella following postnatal exposure. Only 33% of faculty members surveyed feel there are no indications for VZIG in infants exposed after 48 hours of age.

Centers for Disease Control and Prevention, U.S.↗
PubMed1987

Occult bacteremia with nontypeable Haemophilus influenzae.

A 2-year-old boy had occult bacteremia with nontypeable Haemophilus influenzae 6 weeks after receiving H. influenzae type b polysaccharide vaccine. Evaluation of his host defense was normal. As determined by outer membrane protein electrophoresis and Southern hybridization analysis, this strain was not related to type b strains. Its virulence in rats was similar to that of another nontypeable strain and less than that of a type b strain.

Animals↗
PubMed1987

Pneumococcal and Haemophilus influenzae type b antigen detection in children at risk for occult bacteremia.

We prospectively evaluated pneumococcal and Haemophilus influenzae type b antigen detection in serum and urine of young (3 to 30 months of age) febrile (temperature greater than or equal to 39 degrees C) children at risk for occult bacteremia. Patients with septic shock, meningitis, or epiglottitis were excluded. Of 576 patients, 16 had pneumococcal bacteremia (final diagnoses: primary bacteremia, nine; otitis media, four; pneumonia, two; unknown, one), and five had H influenzae b bacteremia (final diagnoses: primary bacteremia, two; cellulitis, two; arthritis, one). Latex agglutination was positive in all five patients with H influenzae b bacteremia (positive in three of three urine specimens, three of four sera tested) but only one of 16 patients with pneumococcal bacteremia (positive in one of seven urine samples, zero of 13 sera tested). Both assays had specificities of greater than 95%. Nonspecific agglutination occurred in 7% of specimens tested. Enzyme immunoassay for pneumococcal antigen, although more sensitive than latex agglutination, failed to detect antigen in ten sera and three urine specimens from patients with pneumococcal bacteremia. Thus, neither latex agglutination nor enzyme immunoassay was sufficiently sensitive for detection of occult pneumococcal bacteremia. Latex agglutination for H influenzae b holds promise as a sensitive and specific test for rapid diagnosis of occult bacteremia due to H influenzae b.

Agglutination Tests↗
PubMed1986

Prognosis of herpes zoster in healthy children.

Previous investigators have suggested that herpes zoster may be the presenting sign of a malignancy. However, no data have been available concerning the prognosis of herpes zoster in normal children. To assess outcome and prognosis for healthy children with a diagnosis of herpes zoster, we collected and reviewed 22 cases of herpes zoster from 90 pediatric practices in our community. In all cases, the illness was of short duration and resolved completely. Patients were followed up by their pediatricians for a mean of 4.2 years, and in no case did malignancy manifest subsequent to the zoster infection. We conclude that herpes zoster is a relatively benign infection in children and, given the period of follow-up, the onset of zoster does not appear to herald the occurrence of malignancy in this population.

Adolescent↗
PubMed1986

Contribution of lipopolysaccharide to pathogenicity of Haemophilus influenzae: comparative virulence of genetically-related strains in rats.

The elaboration of type b capsule plays an important role in determining virulence of Haemophilus influenzae but the contribution of lipopolysaccharide to pathogenicity of this organism remains undefined. Using DNA from a virulent type b H. influenzae donor strain and a capsule-deficient recipient (Rd:01), we constructed capsular transformants having lipopolysaccharide characteristics either similar to (strain Rd/b+:01), or different from (strain Rd/b+:02), the recipient strain. These two type b transformants had similar type b capsule and outer membrane proteins. Comparative virulence studies in rats showed that strain Rd/b+:02 was more virulent than Rd/b+01 as assessed by magnitude of bacteraemia, incidence of meningitis and mortality. Similarly, strain Rd/b-:02 exhibited greater pathogenicity in C3-depleted rats than its genetically-related strain Rd:01. We conclude that lipopolysaccharide composition plays a significant role in mediating the potential of H. influenzae to cause invasive infections. In addition, the findings suggest that there is linkage of virulence genes involved in lipopolysaccharide and capsule expression.

Animals↗
PubMed1986

Comparison of in vivo and in vitro multiplication rates of Haemophilus influenzae type b.

A model of invasive Haemophilus influenzae type b disease in rats was used to compare the net in vivo and in vitro multiplication rates of this bacterium. In both the blood of rats and in vitro cultures (fresh rat blood or enriched broth) there was an exponential increase in the number of CFU per milliliter with calculated net mean generation times as follows: sham-operated rats, 82 +/- 39 min (n = 5); asplenic rats, 34 +/- 5 min (n = 13); broth, 26 +/- 4 min (n = 12); rat blood, 24 +/- 1 min (n = 14). Thus, in vivo multiplication of H. influenzae type b can be extremely efficient.

Animals↗