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Biomedical subjects

R W Steele

Publications and source records attributed to R W Steele.

At least 91 records · Page 5Linked to original sources
PubMed1986

Age-dependent variation of lymphocyte function in the postoperative child.

Circulating lymphocyte profiles and reactivity normally vary with age. Operation results in depression of both lymphocyte counts and blastogenesis but the relationship of age to these alterations has not been previously evaluated in the pediatric surgical patient. This report analyzes the relationship of age to lymphocyte alteration in the postoperative child. Thirty-five healthy children (age range 1 mo to 12 yr), admitted for elective herniorrhaphy, underwent perioperative lymphocyte assay. Anesthesia consisted of halothane and NO2, and operative time averaged 54 minutes. Three milliliters of heparinized whole blood was obtained at induction of anesthesia and at 2 hours postoperatively. Lymphocytes were separated by Histopaque gradient and assayed for absolute count, total T-cells, and total B-cells. Lymphocyte reactivity was determined by 3H-Thymidine incorporation during incubation with the mitogens phytohemagglutinin (PHA), pokeweed (PWM), and/or concanavalin A (Con A) and results expressed as the logarithm of scintillation counts per minute. Differences in preoperative and postoperative values were analyzed for significance by paired T-test. The same differences were evaluated for relationship to age by regression analysis. Operation resulted in significant decreases in all lymphocyte counts (absolute, T- and B-cells), and the operative-induced alteration in both absolute and total B-cell counts were significantly correlated with age (P less than .03, P less than .007, respectively). Similarly, operation resulted in significant depression of lymphocyte reactivity and alteration in B-cell response (PWM) was significantly correlated with age (P less than .008). In all instances of significant correlation, lymphocyte alterations were inversely related to age.(ABSTRACT TRUNCATED AT 250 WORDS)

Aging↗
PubMed1986

Leukocyte survival in cerebrospinal fluid.

Delays in the laboratory examination of cerebrospinal fluid are commonly encountered in clinical medicine. The present studies were designed to evaluate changes in cerebrospinal fluid leukocyte counts relative to time elapsed before analysis. Neutrophil counts decreased most rapidly, being 68 +/- 10% (standard error of the mean) and 50 +/- 12% of initial values at 1 and 2 h, respectively. Lymphocyte and monocyte numbers were not significantly altered until 3 h.

Cell Survival↗
PubMed1986

Selective IgA deficiency.

Selective IgA deficiency is the most common form of immunodeficiency. Certain select populations, including allergic individuals, patients with autoimmune and gastrointestinal tract disease and patients with recurrent upper respiratory tract illnesses, have an increased incidence of this disorder. These patients have the unique ability to form various antibodies and auto-antibodies including anti-IgA antibodies. Failure of terminal differentiation of the B lymphocyte is the primary defect in IgA deficiency. Treatment should be directed toward the underlying disease associated with this immune disorder. These patients should be advised of the consequences of improperly administered blood or blood products.

Antibodies, Anti-Idiotypic↗
PubMed1985

Timentin therapy for bone, joint, and deep soft tissue infections in children.

Timentin, a combination of clavulanic acid (0.1 g) and ticarcillin (3.0 g), has proved effective in vitro against bacterial pathogens that produce beta-lactamases. The usual etiologic bacteria of osteochondritis of the foot (Pseudomonas species) and osteomyelitis/septic arthritis (Staphylococcus aureus) are commonly resistant to penicillins. To date, we have used Timentin to treat 30 children with bone, joint, and deep soft tissue infections. Timentin was administered intravenously at an average dosage of 207 mg/kg per day for mild to moderate infection and 310 mg/kg per day for bone and joint infections with systemic signs (sepsis). The lower dose was used in 24 patients and the other six patients, who had signs of sepsis, received the higher dose. All patients received Timentin intravenously over 30 minutes every four to six hours for a minimum of five days (mean 6.6 +/- 2.6 days, range five to 14 days). The mean time to defervescence and/or reduction in clinical symptoms was 1.6 +/- 1.3 days (range zero to four days). Osteochondritis due to P. aeruginosa was diagnosed in six patients, and septic bursitis, osteomyelitis, or septic arthritis due to S. aureus (13 patients) or Staphylococcus species and group A streptococci (four patients) was diagnosed in 17 patients. All isolates were susceptible to Timentin in vitro by disk-diffusion analysis. All patients showed a response to therapy with Timentin, with or without surgical intervention. All patients had clinical and microbiologic cures; no adverse reactions or side effects were observed. There have been no clinical or microbiologic relapses to date. Timentin may prove to be useful in specific bone and joint infections in children.

Arthritis, Infectious↗
PubMed1985

Intravenous immune globulin for hypogammaglobulinemia: a comparison of opsonizing capacity in recipient sera.

Twelve severely hypogammaglobulinemic patients received infusions of alkylated immune globulin and two other native nonalkylated products. Administration was separated by an interval of 3 weeks. Serum was obtained prior to and at 24 hr and 3 weeks after each infusion for measurement of total IgG, specific and opsonizing antibodies. The latter was accomplished against Streptococcus pneumoniae types 5, 12F and 14 and zymosan using chemiluminescence methodology. Changes in total IgG concentrations were comparable for the three products. Prior to enrollment, IgG levels averaged 115 +/- 72 mg/dl, increasing to 779 +/- 399 at 24 hr postinfusion, and were 337 +/- 200 after 3 weeks. No differences among the products were seen in their ability to produce antibodies against Herpes simplex virus types 1 and 2, rubella, toxoplasma, cytomegalovirus, or tetanus. However, differences in opsonizing antibody were observed between alkylated and native IgG preparations. Peak chemiluminescence responses of neutrophils following opsonization of S. pneumoniae with native immune globulin were significantly higher than with alkylated IgG, indicating greater functional capacity. These studies suggest that native immune serum globulin provides a greater potential for augmenting host defense mechanisms against pneumococcal infection in hypogammaglobulinemic patients.

Adolescent↗
PubMed1985

A prospective randomized comparison of cefotaxime vs ampicillin and chloramphenicol for bacterial meningitis in children.

Fifty children with bacterial meningitis were prospectively randomized to receive cefotaxime (50 mg/kg/dose every 6 hours) or ampicillin and chloramphenicol in standard doses. Twenty-three patients received cefotaxime and 27 received standard therapy. Bacterial isolates included: Haemophilus influenzae (29), Streptococcus pneumoniae (eight), Neisseria meningitidis (eight), group B streptococci (three), and Salmonella enteritidis (two). Ten (34%) of the H. influenzae isolates were resistant to ampicillin, nine on the basis of beta-lactamase production. All strains were susceptible to cefotaxime. Clinical cure rates for the cefotaxime (100%) and standard therapy (96%) groups were similar; survival without detectable sequelae was similar, at 78% and 77%, respectively. The duration of therapy, 11.1 +/- 2.4 days (range 10 to 21 days) vs 11.9 +/- 3.9 days (range 10 to 21 days), and days to defervescence, 4.7 +/- 2.6 days (range 1 to 14 days) vs 5.6 +/- 2.9 days (range 2 to 17 days), were similar in the cefotaxime and standard therapy groups, respectively. No adverse drug reactions or side effects were noted in either group. Cefotaxime was found to be as safe and effective as standard therapy for the treatment of bacterial meningitis in children.

Adolescent↗
PubMed1985

Phagocytosis of type III group B streptococci by neonatal monocytes: enhancement by fibronectin and gammaglobulin.

The potential of fibronectin to enhance phagocytosis of type III group B streptococci by cultured neonatal monocytes was evaluated. Fibronectin had significantly less effect on phagocytosis compared with type-specific antibody to group B streptococci; fibronectin increased the cell association of organisms to a level comparable to that of adult pooled serum and significantly more than that of serum-free controls. Microbicidal activity suggested that this cell association consisted of attachment but not ingestion, and electron micrographs showed the extracellular location of these organisms. In contrast, the effect of fibronectin on type III group B streptococci preopsonized with intravenous gammaglobulin revealed significantly greater numbers of cell-associated organisms than did addition of type-specific antibody to group B streptococci, pooled adult serum plus fibronectin, or serum-free controls. Phagocytosis was similar when assessed by microbicidal activity compared with the cultures with added type-specific antibody and significantly greater when compared with those with added pooled serum, and results were confirmed by electron microscopy. Therefore, fibronectin together with intravenous gammaglobulin enhanced ingestion of type III group B streptococci by neonatal monocytes.

Cells, Cultured↗
PubMed1985

Response to pneumococcal vaccine in renal allograft recipients.

Pneumococcal vaccine, 14-valent, was administered to 75 stable adult renal transplant patients on maintenance immunosuppression. 32 had undergone splenectomy prior to transplantation and 43 had not. Functional opsonizing antibody was measured by chemiluminescence methodology for types 12F and 14, contained in the vaccine, and for type 5, a control strain. Serum was examined prior to and at 1 and 6 months after vaccine injection. 33, 71, and 35% of transplant patients had preexisting antibody to types 5, 12F, and 14, respectively, as compared to 58, 87, and 68% of controls. No differences were observed in nonsplenectomized versus splenectomized patients. Following immunization, 59 and 76% of antibody-negative patients converted to positive for pneumococcus type 12F and 14. These included 70 and 70% for nonsplenectomized patients as compared to 50 and 84% for those splenectomized. Vaccination did not result in the production of opsonizing antibody for the related type 5 pneumococcus. Pneumococcal vaccine generates functional antibody and is safe in renal transplant patients.

Adult↗
PubMed1985

Psychologic modulation of the human immune response to varicella zoster.

Psychoimmunology, the interrelationship between the brain/mind/psyche and the immune system, is now an established area of scientific research. Based on prior investigations we hypothesized that an experienced meditator could affect her delayed hypersensitivity reaction by a psychological process. A single-case study design was employed in which the subject was skin tested weekly with varicella zoster skin test reagent. After baseline immunologic studies, she was able, as hypothesized, to significantly reduce both the induration of her delayed hypersensitivity skin test reaction and in vitro lymphocyte stimulation to varicella zoster. Then, as predicted, she was able to allow her reaction to return to baseline. As a confirmation of what is to our knowledge this previously undescribed phenomenon, she was able to reproduce the entire sequence nine months later. It appears that this subject can intentionally modulate her immune response by a psychologic mechanism.

Antigens, Viral↗
PubMed1985

The inhibition of norepinephrine release in nasal mucosa by acetylcholine.

Tritiated norepinephrine was incorporated into isolated dog nasal mucosa. Electrical stimulation of this mucosa induced a release of the tritiated norepinephrine. Acetylcholine inhibited this release in a dose-related manner. The inhibition is prevented by atropine. This data provides further evidence for the existence of presynaptic, inhibitory, muscarinic receptors on the sympathetic nerve terminals in nasal blood vessels.

Acetylcholine↗
PubMed1985

Recurrent bacterial meningitis: coronal thin-section cranial computed tomography to delineate anatomic defects.

Three patients with histories of recurrent bacterial meningitis were previously examined with skull and sinus radiographs, routine cranial computed tomography, intrathecal radioisotope tracer studies, and immunologic evaluation. None of these studies were diagnostic. Pneumococcal vaccine and prophylactic penicillin therapy were ineffective in preventing recurrent episodes in two cases. Thin-section (2-mm) direct coronal computed cranial tomography demonstrated anatomic defects in all three patients. The use of metrizamide cisternography was not necessary to diagnose the defects. All patients had basiethmoidal encephaloceles which were repaired surgically. Direct coronal computed tomography offers a relatively easy noninvasive method for delineating anatomic abnormalities in patients with recurrent meningitis.

Child↗
PubMed1984

Ceftriaxone therapy of meningitis and serious infections.

Thirty pediatric and young adult patients with bacterial meningitis were treated with ceftriaxone or "standard therapy" in a comparative trial; 41 other patients with severe bacterial infections were treated with ceftriaxone in an open protocol. Meningitis and brain abscesses were treated successfully with 50 mg/kg of ceftriaxone every 12 hours. In children, other infections were treated with 25 to 37.5 mg/kg of ceftriaxone every 12 hours. Young adults with pneumonia received 1 g of the antibiotic every 12 hours, whereas those with soft tissue infections were treated every 24 hours. All patients responded to therapy, and in all but one was the infectious process sterilized. No significant toxicity was observed. Ceftriaxone appears to be an excellent single agent for the treatment of most severe bacterial infections in pediatric and young adult patients and need not be administered more frequently than once every 12 hours.

Adolescent↗
PubMed1984

The effects of diltiazem on Periplaneta americana.

The effects of the calcium antagonist diltiazem on nerve and muscle in the cockroach Periplaneta americana were examined. Diltiazem was observed to inhibit myogenic and glutamate-induced contractions of the visceral muscle while having either a potentiating, an inhibiting or a biphasic effect against proctolin-induced contractions. Against the isolated nervous system, diltiazem induced an increase in spontaneous discharge activity, followed by nerve block. Injection of diltiazem into cockroaches produced behavioral and toxic effects.

Action Potentials↗
PubMed1984

Surgically induced immunologic alterations in the child.

Surgery is generally believed to be an immunodepressant. This assumption is based, in part, upon studies of compromised patients undergoing major operation. Similar studies in normal adults following elective procedures are contradictory and little information is available regarding the pediatric surgical patient. This paper presents a study of immune function in children undergoing elective operation. Fifty healthy preoperative children (mean age: 20 months) were randomly selected. Ninety-five percent underwent inguinal herniorrhaphy. Operative time averaged 45 minutes (range: 30 to 90 minutes). Anesthesia consisted of Halothane and Nitrous Oxide in all cases. Approximately 2.5 cc of heparinized blood and 0.5 cc of serum were obtained immediately prior to and 2 hours following operation. Half of the children underwent assays of neutrophil function including absolute count, random migration, chemotaxis, phagocytosis, and bacterial killing. Serum was examined for opsonization of Staphylococcus aureus using the chemiluminescence method. The remaining children underwent lymphocytic quantitation including absolute count, total T cells, total B cells, T-helper cells, T-suppressor cells, and T-helper/suppressor ratio. Absolute neutrophil count increased 2.4 times preoperative values (P less than 0.01). There were, however, no significant alterations in neutrophil functional capabilities. Similarly, there was no alteration in serum opsonic capacity. There was a significant decrease in absolute lymphocyte count (6560-4013, P less than 0.01) postoperatively, and T cells, T-helper, T-suppressor, and B cells were all significantly affected (P less than 0.01 to 0.02). There was no change in the T-helper/suppressor ratio.(ABSTRACT TRUNCATED AT 250 WORDS)

Chemotaxis, Leukocyte↗
PubMed1983

Ceftriaxone for the treatment of serious infections.

Ceftriaxone is an investigational cephalosporin with a half-life of five to eight hours. In an uncontrolled study, we evaluated its efficacy and safety in 30 pediatric and 12 young adult patients with serious bacterial infections. This agent was administered to children at a dosage of 50 to 75 mg/kg/day intravenously in two divided doses. Those with CNS infections received 100 mg/kg/day. In adults, the dosage was 1 g either once or twice daily. The diseases we treated included pneumonia (17), sepsis (eight), ventriculoperitoneal shunt infections (three), osteomyelitis (three), brain abscess (two), peritonitis (two), and miscellaneous (seven). Clinical cures were achieved in all cases, although one child with cystic fibrosis and Pseudomonas pneumonia had persistent colonization in his sputum. No serious side effects were observed. Although not the agent of choice for many of these pathogens, ceftriaxone appears to represent an important alternative to therapy.

Bacteria↗
PubMed1983

Bacterial meningitis in older neonates.

During a five-year period, 24 patients' conditions (age range, 2 to 6 weeks) were diagnosed, and they were treated for bacterial meningitis. Organisms recovered from the CSF included group B Streptococcus (n = 6), Escherichia coli (n = 5), Listeria monocytogenes (n = 5), Hemophilus influenzae (n = 4), Streptococcus pneumoniae (n = 2), and group D and group A Streptococcus (one each). Initial antimicrobial therapy must include antibiotics that are effective across this spectrum of potential pathogens. Symptoms and signs were often subtle. Six children (25%) experienced major neurologic residua, including five patients (21%) in whom hydrocephalus developed. Ultrasound examination of the head at the end of therapy was an effective technique for early assessment of neurologic sequelae.

Bacterial Infections↗