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Biomedical subjects

G J Hauser

Publications and source records attributed to G J Hauser.

At least 37 records · Page 2Linked to original sources

Circulating endotoxin and tumor necrosis factor during pediatric cardiac surgery.

OBJECTIVES: To study the hypothesis that endotoxin and tumor necrosis factor-alpha (TNF) are released into the circulation during the perioperative period in children undergoing open-heart surgery, and to assess the possible role of these factors in postoperative morbidity. DESIGN: Prospective study. SETTING: Operating room and ICU of a children's hospital. PATIENTS: Twenty-four consecutive patients undergoing open-heart surgery for repair of congenital heart disease. METHODS: Endotoxin and TNF concentrations were measured in blood samples withdrawn from patients at predetermined time points in the perioperative period. These concentrations were also measured in samples from all fluids and drugs administered to patients. Clinical variables were measured throughout the perioperative period, and the Pediatric Risk of Mortality score was calculated daily. RESULTS: All of the preoperative control samples were negative for endotoxin and TNF. Endotoxin or TNF was detected in the blood of 21 (88%) of 24 patients during or after surgery. Endotoxin (ranging in concentrations from 0.32 to 438 pg/mL) was detected in the blood of 16 (67%) of the 24 patients. The majority of the samples positive for endotoxin were withdrawn during cardiopulmonary bypass and were associated with positive samples from the pump, from cardiotomy suction specimens, and from autotransfused blood. Blood cultures of all patients, except one, were negative for bacterial growth. TNF (ranging in concentrations from 3 to 132 U/mL) was detected in the blood of nine (37%) of the 24 patients. Patients positive for TNF had significantly (p less than .05) lower mean central venous pressures at 20 hrs after surgery and higher mean heart rates postoperatively compared with patients negative for TNF. No differences in other indicators of perioperative morbidity and intraoperative conditions were found, when the groups positive for endotoxin or TNF were compared with the groups negative for endotoxin or TNF, respectively. CONCLUSIONS: Endotoxin and TNF are released into the circulation during and after pediatric open-heart surgery. TNF release may be related to some of the hemodynamic changes observed after open-heart surgery.

Child↗

Immune dysfunction in children after corrective surgery for congenital heart disease.

OBJECTIVE: To study the effect of open- and closed-heart surgery on the immune status of infants and children. DESIGN: Prospective study. Data collected before anesthesia and surgery and 2 and 24 hrs after surgery. SETTING: Operating room and pediatric ICU in a children's hospital. PATIENTS: Children undergoing surgery for correction of congenital heart disease (age 3 months to 12 yrs). A total of 31 patients were studied (open-heart surgery, n = 25; closed-heart surgery, n = 6). MEASUREMENTS AND MAIN RESULTS: Increased neutrophil counts and lymphopenia were observed after both open- and closed-heart surgery. Serum levels of the complement components C3 and C4 were depressed after open-heart surgery, but not after closed procedures. The percentage of T3+ and T4+ lymphocytes, proliferative responses of the lymphocytes and serum immunoglobulin (Ig)G and IgM were decreased from preoperative levels after open-heart surgery. The percentage of T8+ lymphocytes and serum IgA levels did not change. Intraoperative variables and postoperative severity of illness (Pediatric Risk of Mortality score) did not correlate with immune suppression. CONCLUSIONS: The immune system is affected after pediatric cardiac surgery, particularly after open-heart surgery.

Cardiac Surgical Procedures↗

Manipulation of oxygen radical-scavenging capacity in mice alters host sensitivity to tumor necrosis factor toxicity but does not interfere with its antitumor efficacy.

The role of oxygen free radicals in the toxicity and antitumor effect of tumor necrosis factor was investigated in vivo. Treatment of non-tumor-bearing mice and mice bearing methylcholanthrene-induced sarcomas with bovine CuZn superoxide dismutase or recombinant human CuZn superoxide dismutase afforded significant protection to these mice from a subsequent challenge with recombinant human tumor necrosis factor (rhTNF). Pretreatment with superoxide dismutase increased survival rates, at 48 h after rhTNF injection, in non-tumor-bearing mice from 22 to 65% and in tumor-bearing mice from 25 to 79%. Protection from rhTNF toxicity was not associated with any reduction in the therapeutic efficacy of rhTNF against methylcholanthrene-induced sarcomas in either s.c. or visceral sites (e.g., cure rates in mice bearing s.c. tumors which were treated with rhTNF without or with superoxide dismutase pretreatment were 18 and 39%, respectively). Furthermore, the administration of L-buthionine-S,R-sulfoximine, an inhibitor of glutathione synthesis, to mice bearing s.c. tumors resulted in increased rhTNF toxicity but no improvement in therapeutic efficacy. Tumor necrosis factor toxicity is mediated by the release of oxygen free radicals, probably from activated neutrophils, but its antitumor effect in methylcholanthrene-induced sarcomas is not dependent on their generation.

Animals↗

Prospective evaluation of a nonradiographic device for determination of endotracheal tube position in children.

A new noninvasive, nonradiographic endotracheal tube (ETT) position detection system (ETT-PDS) for guidance of ETT positioning was evaluated in pediatric ICU patients. The system includes an ETT with a metallic element embedded at a defined distance from the ETT tip, and a portable locator instrument which detects transcutaneously the position of the metallic element. The contribution of ETT-PDS to accuracy of ETT positioning after intubation and before chest radiographs was evaluated in 92 critically ill children. The ETT malposition rates observed on the postintubation chest radiographs were 39.1% after positioning guided by clinical assessment alone, and 19.6% after positioning guided by clinical assessment plus the ETT-PDS (p less than 0.5). This reduction in malnutrition rate could not be demonstrated when the ETT-PDS was used to guide routine ETT positioning performed before morning chest radiographs.

Critical Care↗

Efficacy of chest radiography in pediatric intensive care.

We prospectively evaluated the efficacy and clinical usefulness of bedside chest radiography in a pediatric intensive-care unit. Seven hundred ninety-five radiographs were evaluated in 126 patients over a 10-week period. Eighty-one percent of all radiographs showed one or more cardiopulmonary abnormalities, and 25% of routine radiographs had findings that altered management of patients. Nineteen percent of radiographs, including 17% of routine radiographs, showed a malpositioned tube or catheter. Thirty-five percent of endotracheal tubes shown on postintubation radiographs and 41% of central venous catheters shown on post-catheter placement radiographs were malpositioned. Forty-five percent of radiographs with a previous reading showed a significant interval change. Radiographs in patients 1 year old or younger showed more cardiopulmonary abnormalities (p less than .04), tube or catheter malpositions (p less than .03), and significant interval changes (p less than .03), and they elicited more changes in clinical management (p less than .01) than did radiographs in patients over 1 year old. The frequency of management changes dictated by radiographs increased with increasing amounts of respiratory support (p less than .01). Our data indicate that bedside radiography in the pediatric intensive-care setting has a high efficacy and clinical utility.

Adolescent↗

Immobilization hypercalcemia: unusual presentation with seizures.

Immobilization hypercalcemia usually causes mild neurologic symptoms. Seizures are a rare complication, appearing weeks after the appearance of other symptoms of hypercalcemia. We report here the case of a 10-year-old boy who developed generalized seizures early in the course of the syndrome. In this child, early diagnosis and therapy probably prevented the more complicated course described in previous cases. We wish to draw attention to this potentially life-threatening complication of immobilization.

Child↗

Routine chest radiographs in pediatric intensive care: a prospective study.

The clinical value of routine chest radiographs was prospectively evaluated in a pediatric intensive care unit. Physicians were asked to predict findings of clinical impact in 353 routine morning chest radiographs performed in 101 patients after examining the patients. In 81 instances (23%), the clinical impact of the chest radiographs was incorrectly predicted and significant alterations in management would have potentially been missed had the chest radiographs not been available. These 81 chest radiographs included 72 unpredicted radiographic changes of clinical significance, and nine chest radiographs in which a significant radiographic change was incorrectly predicted. Thirty five (43.2%) of these 81 chest radiographs had unpredicted pulmonary findings and 46 (56.8%) showed unpredicted appliance malpositions. Incorrect predictions were significantly associated with radiographs from patients who were younger, intubated, mechanically ventilated, and had indwelling central venous catheters. Level of training of the predicting physicians did not affect prediction accuracy. In analysis of 43 routine postintubation chest radiographs and 39 routine postcentral venous catheter placement chest radiographs, appliance malpositions were disclosed in 34.9% and 43.6%, respectively. Routine daily and post-appliance placement chest radiographs have significant clinical value in the pediatric intensive care unit.

Adolescent↗

Immune dysfunction in the critically ill infant and child.

Factors contributing to the high prevalence of immunodeficiency in the PICU population include conditions that lead to frequent requirement of intensive care, suppression of immunity secondary to an acute insult, and iatrogenic measures. The immunodeficiency observed in the critically ill correlates well with their susceptibility to infection and explains the high prevalence of nosocomial sepsis in the PICU--a major cause of morbidity and mortality in critically ill children. Dysactivation of the immune system during an acute insult, with the subsequent release of humoral mediators from activated immune cells, leads to tissue injury and may be involved in the pathogenesis of ARDS, DIC, capillary leak syndrome, and to the development of multiple organ system failure. Suggested approaches to correct the immunodeficiency in the critically ill include reconstitutional immunotherapy, mediator-inhibiting drugs, and mediator removal by plasma exchange. Intensivists should be aware of the phenomenon of immunodeficiency in the critically ill, be accordingly aggressive in diagnosing and treating infections, and avoid, as much as possible, measures that further suppress immunity.

Acquired Immunodeficiency Syndrome↗

Control of a Serratia marcescens outbreak in a maternity hospital.

During the period between October 1984 and January 1985, an outbreak of Serratia marcescens took place in the Serlin Maternity Hospital in Tel-Aviv. Four major and six minor infections were noted in newborn and preterm infants. An additional group of 24 neonates were asymptomatic carriers of S. marcescens. Extensive control measures were undertaken, including closing the SCBU to further admissions and the opening of a new SCBU. Other measures included maintaining babies in cohort groups, strict handwashing, and use of gloves and gowns. There was also intensified encouragement of breast feeding and thorough cleansing and disinfection of the SCBU and nurseries. After 3 months, the outbreak was controlled. No identified source for the outbreak was detected. We feel that the extensive measures employed were responsible for controlling the outbreak within a relatively short time.

Bacteriological Techniques↗

Immunocompetence in pregnancy: production of interleukin-2 by peripheral blood lymphocytes.

Pregnancy is a natural allograft and the mechanisms for its non-rejection are obscure. Depression of maternal cellular immunity was suggested as a possible explanation. Interleukin-2(IL-2) is a lymphokine release from OKT4+ lymphocyte. This factor has a crucial role in the proliferation and differentiation of T cell subsets, and controls functions associated with immune rejection mechanisms. We therefore examined the ability of lymphocytes from women in the 3 trimesters of pregnancy to produce IL-2 in culture. Mononuclear cells were cultured with PHA for 48 h. The IL-2-containing supernatant was added to and supported the proliferation of an IL-2 dependent T cell line. Proliferation of this line indicated the IL-2 content of the added supernatant. Using this assay, IL-2 production in all 3 trimesters of pregnancy was adequate and comparable to that of lymphocytes from non-pregnant women. These results suggest that the proposed defect in cellular immunity during pregnancy is not mediated by an inability of the lymphocytes to produce IL-2.

Adult↗

Peculiar odours in newborns and maternal prenatal ingestion of spicy food.

A peculiar odour in an infant may raise the possibility of several important syndromes. Four cases of newborn infants with peculiar smells are described. In two, the sharp odour was identified as cumin, one smelled of fenu-greek and one of curry. All these babies were born to mothers who ingested spicy food prior to delivery. In one case, the foul smelling amniotic fluid led to a spurious suspicion of amniotitis.

Condiments↗

Interleukin-2 production by cord blood lymphocytes stimulated with mitogen and in the mixed leukocyte culture.

We examined the ability of cord blood lymphocytes to produce interleukin-2 (T cell growth factor) in response to phytohemagglutinin and in the mixed leukocyte culture. Interleukin-2 production was measured by the proliferative response of an interleukin-2-dependent mouse T cell line to the addition of supernatant obtained from cord blood lymphocyte cultures. Using these assays we have shown that cord blood lymphocytes have a normal ability to produce interleukin-2 in both PHA-stimulated cultures and in the mixed leukocyte culture. The normal production of interleukin-2 by cord blood cells indicates, that newborn T lymphocytes are mature, and that a dissociation exists between their normal ability to produce interleukin-2 and their ability to produce other lymphokines, which was reported to be impaired. The reported deficiency of HLA-DR antigen expression on newborn monocytes does not seem to interfere with the production of interleukin-2 in the mixed leukocyte culture.

Fetal Blood↗

Effect of alpha-methyldopa excreted in human milk on the breast-fed infant.

A nursing infant whose mother took alpha-methyldopa (alpha-MD) was followed for 3 months. Analysis of maternal serum and milk as well as the infant's serum and urine for alpha-MD revealed that the drug was excreted into maternal milk, absorbed by the infant and excreted in her urine, but no adverse clinical effects were noted during the follow-up period. alpha-MD is excreted in human milk in concentrations that probably do not harm the breast-fed infant.

Adult↗

Interleukin-2 production and response to exogenous interleukin-2 in a patient with the acquired immune deficiency syndrome (AIDS).

The ability of lymphocytes from a patient suffering from the acquired immune deficiency syndrome (AIDS) to produce interleukin-2 (IL-2) was found to be comparable to that of his healthy sex partner and to that of a normal control. Addition of exogenous IL-2 to lymphocyte cultures did not improve the poor mitogen response to phytohaemagglutinin in this patient. Our data suggest that the underlying defect in this AIDS patient is due to an IL-2 receptor defect.

Acquired Immunodeficiency Syndrome↗