Metabolism of arachidonic acid by rat adrenal glomerulosa cells: synthesis of hydroxyeicosatetraenoic acids and epoxyeicosatrienoic acids.

Metabolites of arachidonic acid have been implicated in the regulation of aldosterone release. To form a basis for further investigations in this area, the present study has isolated and identified the metabolites formed from exogenous arachidonic acid by adrenal zona glomerulosa cells and characterized the effects of several inhibitors on the synthesis of these eicosanoids. Rat adrenal glomerulosa cells metabolized exogenous [14C]arachidonic acid to products comigrating with the prostaglandins (PGs), hydroxyeicosatatraenoic acids (HETEs) and epoxyeicosatrienoic acids (EETs). The metabolites were found in the cells and the incubation media; however, none of the metabolites were found esterified to cellular lipids. The major metabolites were identified as 6-keto PGF1 alpha, PGE2, PGF2 alpha, PGD2, 12(S)-HETE, 15(S)-HETE, 14,15-EET, 11,12-EET, 8,9-EET, and 5,6-EET. The identities of the HETEs and EETs were confirmed by gas chromatography/mass spectrometry. There was no evidence for the synthesis of leukotrienes. The cyclooxygenase inhibitor, indomethacin, the lipoxygenase inhibitors, nordihydroguaiaretic acid, baicalein and AA861, and the combined cyclooxygenase/lipoxygenase inhibitors, BW755C and eicosatetrayenoic acid, inhibited the formation of the [14C]PGs, the [14C]HETEs, and the [14C]EETs. Metyrapone and clotrimazole, inhibitors of cytochrome P450, increased the synthesis of [14C]PGs and [14C]HETEs and reduced the synthesis of [14C] EETs. Superoxide dismutase did not alter arachidonic acid metabolism. In contrast, arachidonic acid metabolism was increased in cells pretreated with catalase. These data indicate that adrenal glomerulosa cells metabolize exogenous arachidonic acid to a number of oxygenated metabolites including PGs, HETEs, and EETs. From studies with inhibitors, the EETs appear to be synthesized by a cytochrome P450 epoxygenase and the HETEs by lipoxygenases.

Cytomegalovirus infections: occupational risk for health professionals.

Health care personnel are becoming increasingly aware of potential hazards associated with caring for patients with contagious diseases. The cytomegalovirus is of special concern, because infection with this virus in a pregnant female employee could be associated with significant neurologic injury in her fetus. Nosocomial transmission from patient to health care worker has not been documented. A review of cytomegalovirus excretion in hospitalized patients and prospective evaluations of primary infection in hospital personnel do not support frequent occurrence of cytomegalovirus infection despite ample opportunity for exposure. Adherence to proper isolation techniques should be adequate to prevent nosocomial transmission of the cytomegalovirus.

Survival and disinfection of parainfluenza viruses on environmental surfaces.

Three dilutions of each of three parainfluenza strains were placed on nonabsorptive (stainless steel, laminated plastic, skin) and absorptive (hospital gown, facial tissue, laboratory coat) surfaces to assess persistence of virus recovery at 0, 0.5, 1, 2, 4, 6, 8, and 10 hours. Virus persisted longest on stainless steel. Additionally, the ability to recover virus was enhanced by increasing the initial concentration of virus in the initial inoculum. Drying of the inoculum on surfaces reduced but did not immediately eliminate the ability to recover virus. Cleaning the contaminated surface with a number of commonly available disinfectant or antiseptic agents reduced or eliminated virus with only short exposure times. It is likely that removal of contaminated material by vigorous cleaning was as important as the actual disinfecting substance. In general, all three strains of parainfluenza virus responded similarly. Persistence of all three strains of parainfluenza virus for up to 10 hours on nonabsorptive surfaces and up to 4 hours on absorptive surfaces suggests a need to consider fomites a possible source of transmission of the parainfluenza viruses inside and outside the hospital.

Factors associated with cytomegalovirus excretion in hospitalized children.

Hospital employees, especially pregnant women, have expressed concern over exposure to patients excreting cytomegalovirus (CMV). However, the vast majority of CMV excreters are asymptomatic and are not identified while hospitalized. As part of a 2-year, longitudinal study of nosocomial transmission of CMV in a children's hospital, the prevalence rates of CMV excretion by patients in different areas of the hospital were determined. The average prevalence rates were neonatal intensive care unit, 5.7%; intermediate care nurseries, 4%; premature nursery, 6.3%; normal newborn nursery, 3%; hematology-oncology, 3.7%; pediatric intensive care unit, 3.6%; general pediatric ward, 6%; and a chronic care unit, 16%. During this 2-year study, 315 patients admitted to the chronic care unit were investigated to determine which clinical factors might help predict children likely to excrete CMV. With the use of multiple logistic regression analysis of variables, prior excretion of CMV, multiple hospital admissions, female sex, and Hispanic ethnic background were correlated with excretion. Although not identified as significant factors, a history of premature, bronchopulmonary dysplasia and positive results of CMV serologic studies were more commonly associated with excretion. CMV excretion occurred in all areas within a children's hospital, and certain factors were associated with excretion, but it is unlikely that this information could adequately identify "safe" patients or safe areas within a hospital. This study reinforces the need to follow proper precautions with all patients.

Method of blood processing affects the prevalence of cytomegalovirus excretion in newborn nurseries.

The potential risk of exposure by hospital personnel and noninfected patients to patients excreting the cytomegalovirus (CMV) may be increased in areas of high prevalence of CMV excretion, such as the neonatal nursery. These personnel are particularly sensitized to the adverse effects of intrauterine CMV infection because they frequently care for the severely affected congenitally infected infants. Multiple transfusions with conventionally processed blood have been associated with high excretion rates in sick preterm neonates. During a 4-year period, four separate methods of blood preparation were used. Two of these methods (CMV-seronegative blood and frozen deglycerolized red blood cells) have been previously shown to be effective in reducing posttransfusion CMV infection. We were able to show that excretion rates in neonates were significantly lower when CMV-seronegative blood and frozen deglycerolized red blood cells were used than when conventionally processed blood and saline-washed red blood cells were used. In areas where posttransfusion CMV infection has been identified as a problem, the increased expense of specially processed blood can be justified, not only to reduce transfusion-associated disease but also to minimize exposure of the hospital staff and noninfected patients to patients excreting CMV.

Diagnostic studies of nosocomial diarrhea in children: assessing their use and value.

During a 17-month period (01/11/85-05/31/86) 225 cases of nosocomial diarrhea were identified in a children's hospital. Diarrhea was considered to be nosocomial if it began at least 72 hours after the patient's hospital admission or within 3 days after discharge. One or more routine diagnostic studies for identification of a pathogen were performed in 195 (87%) cases. The most commonly performed test was the bacterial stool culture. None of these samples yielded a bacterial pathogen. The only pathogens detected by routine laboratory studies were rotavirus (61/137 [45%] samples were positive for rotavirus by ELISA) and Clostridium difficile (9/54 [17%] positive for toxin). Of the patients whose tests were positive for rotavirus 56 were younger than 2 years of age, and all were identified in the winter and spring. When multiple stool samples were tested by the diagnostic laboratory, rotavirus was identified in an additional 14 patients whose initial stool samples were negative for rotavirus. All patients whose tests were positive for C. difficile toxin had received antibiotics within the previous 3 months. Ova/parasites were not detected in 53 of the tested stools. We also identified enteric adenovirus in six patients. Viruses were identified in 95 (42%) of the 225 cases of nosocomial gastroenteritis. Nosocomial diarrhea is common in a children's hospital. Rotavirus is the most commonly identified pathogen. Rotavirus testing is valuable in children with nosocomial diarrhea who are younger than 2 years of age, especially in the winter and spring. Multiple samples may be necessary to identify rotavirus. C. difficile toxin assay should be considered for patients who are receiving or who have received antibiotics.(ABSTRACT TRUNCATED AT 250 WORDS)

Nosocomial infection rates in US children's hospitals' neonatal and pediatric intensive care units.

BACKGROUND: Few data are available on nosocomial infections (NIs) in US children's hospitals' neonatal or pediatric intensive care units. The Pediatric Prevention Network (PPN) was established to improve characterization of NIs in pediatric patients and to develop and test interventions to decrease NI. METHODS: Fifty participating children's hospitals were surveyed in 1998 to determine NI surveillance methods used and neonatal intensive care unit (NICU) and pediatric intensive care unit (PICU) 1997 NI rates. Data were collected on standardized forms and entered and analyzed by using SPSS for Windows. RESULTS: Forty-three (86%) children's hospitals returned a completed questionnaire. All reported conducting NICU and PICU NI surveillance (range, 2-12; median, 12 months). Nineteen children's hospitals provided NICU NI rate data in one or more formats suitable for comparison. Denominators used for NICU NI rate calculations varied: 17 reported overall NI by patient-days; 19 reported bloodstream infection (BSI) by central venous catheter (CVC)-days, and 8 reported BSI by patient-days. Sixteen (16) children's hospitals reported NICU BSI data stratified by CVC-days and birth-weight cohort, and ventilator-associated pneumonia (VAP) by birth weight cohort was reported by 12. Twenty-four children's hospitals reported PICU NI rate data in one or more formats suitable for comparison. Denominators used for PICU NI rate calculations also varied: 20 reported overall NI rates by patient-days; 23 reported BSI rates by CVC-days, and 10 reported BSI rates by patient-days; 24 reported VAP by ventilator-days; and 15 reported urinary tract infections (UTIs) by urinary catheter-days. Median overall NI rates per 1000 patient days were 8.9 in NICUs and 13.9 in PICUs. Median NICU NI device-associated rates by birth weight (>2500 g, 1501-2500 g, 1001-1500 g, and

Treatment of human immunodeficiency virus infection and its associated complications in children.

Providing care to human immunodeficiency virus (HIV)-infected children requires a comprehensive, multidisciplinary approach. This review will address the current status of supportive care, treatment of HIV-associated complications and specific antiretroviral therapy. HIV affects multiple locations in the body resulting in a myriad of possible complications. These include opportunistic infections and malignancies secondary to immunodeficiency and central nervous system or other specific organ-related disease secondary to direct HIV involvement. Recent scientific advances have markedly enhanced the quantity and quality of life of HIV-infected children. Prophylaxis of Pneumocystis carinii pneumonia is the single most important therapeutic advance for the HIV-infected patient. Other advances for the treatment and prevention of HIV-related infections should similarly improve survival and reduce hospital stays. Antiretroviral therapy is relatively new. The currently available nucleoside reverse transcriptase inhibitors have proven efficacy. The role of single agents or combinations is being established. However, this group of antivirals has limitations that make alternate approaches essential. Augmentation of the patient's immune response will likely be a key to any future successful treatment regimen.

Management of infections in children with cancer.

Infectious complications remain a frequent cause of morbidity and mortality in children with cancer, especially in those who are granulocytopenic. Physicians caring for these children must approach each new febrile episode as if it were life threatening. Questions concerning the present illness must be comprehensive. The physical examination should be done in a compulsive manner because the more obvious signs of inflammation are often absent because of granulocytopenia. Immediate initiation of broad-spectrum intravenous antibiotic coverage is required once the appropriate specimens for diagnostic microbiology studies have been obtained. Because these patients may exhibit either dramatic or, more often, only subtle clinical findings, they must be monitored closely and have a complete physical examination at least daily. The laboratory studies frequently determine the etiology of the fever. Therapy can then be modified, based upon the particular pathogen isolated or the type of infection identified. Because bacterial infections are responsible for most infectious febrile episodes in the granulocytopenic child with cancer, appropriate antibiotic therapy usually is curative. However, some patients remain febrile and granulocytopenic without explanation. These patients frequently have a fungal infection and respond to amphotericin B therapy. Our present armamentarium of antimicrobial agents against the common pathogens encountered in cancer patients, except for cytomegalovirus, is adequate. Future advances in therapy of infections in children with cancer will probably be in the area of immunotherapy. This would include both passive administration of products to strengthen a debilitated immune system, together with active immunization with the aim to prevent infectious complications. Prevention of infection in the cancer population may be one of the keys to producing longer remissions and prolonged overall survival, by enabling pediatric oncologists to administer more intensive induction chemotherapy.

Improved myeloperoxidase assay for quantitation of neutrophil influx in a rat model of endotoxin-induced uveitis.

Previously described models of endotoxin-induced uveitis quantify neutrophil influx into the eye using biochemical or direct cell count methods that result in an underestimation of ocular leukocyte accumulation following the inflammatory stimulus. We have optimized the rat model of endotoxin-induced uveitis by first overcoming interference in the biochemical assay of myeloperoxidase due to endogenous ocular reductants and cellular constituents containing free thiol functional groups. This was accomplished by simultaneously 1) extensively diluting soluble, interfering substances and 2) blocking tissue sulfhydril functional groups during tissue homogenization. Uveitis was induced in rats by subplantar injection of endotoxin. Twenty-four hours later, eyes were enucleated, homogenized, fractionated, and myeloperoxidase activity of neutrophils sedimenting with the membranous pellet was extracted. Previously published extraction procedures yielded only 40% of total assayable myeloperoxidase activity. Optimal recovery of myeloperoxidase activity (>twofold increase) was achieved only with two sequential extractions using 50 mM phosphate buffer (pH 7.4) containing 10 mM N-ethylmaleimide, and subsequent solubilization of myeloperoxidase activity by extraction with 0.5% hexadecyltrimethylammonium bromide in 50 mM phosphate buffer (pH 6.0). This modified extraction procedure and optimized myeloperoxidase assay conditions (300 microM hydrogen peroxide and 1.5 mM o-dianisidine) were then used to enhance the uveitis model. Maximum ocular neutrophil accumulation was observed at endotoxin doses of 100-200 microg. Total ocular neutrophil infiltrations ranged from 250,000 to 800,000 cells/globe. This leukocyte influx was inhibited dose-dependently by topical ocular administration of dexamethasone, with half-maximal inhibition observed at a concentration of 0.01%, w/v. Further validated by the correlation of biochemical results with histological evaluation, the refined methodology described in this report has application in assessing the ophthalmic therapeutic potential of antiinflammatory agents.

Periorbital cellulitis secondary to Conidiobolus incongruus.

A previously healthy, 18-month-old girl developed edema and erythema around her left eye 1 week after getting sand in that eye. The patient did not respond to oral or intravenous antibiotics. A mass developed around the eye, and biopsy revealed Conidiobolus incongruus. The patient failed to respond to amphotericin B 1 mg/kg, and susceptibility tests indicated multiantifungal resistance. A combination of antifungal therapy, hyperbaric oxygen, and surgery was required for successful treatment. Three months after treatment the child was disease free. There is no definitive therapy for Conidiobolus incongruus infections, although various drugs have been administered with some success. When susceptibility tests determine multidrug resistance, radical resection with antifungal chemotherapy and hyperbaric oxygen may be necessary as well as lifesaving.

Nepafenac, a unique nonsteroidal prodrug with potential utility in the treatment of trauma-induced ocular inflammation: I. Assessment of anti-inflammatory efficacy.

Nepafenac, the amide analog of 2-amino-3-benzoylbenzeneacetic acid (amfenac), was examined in preclinical models for its potential utility as a topical ocular anti-inflammatory agent. Diclofenac was selected as the reference compound. In contrast to diclofenac (IC50 = 0.12 microM), nepafenac exhibited only weak COX-1 inhibitory activity (IC50 = 64.3 microM). However, amfenac was a potent inhibitor of both COX-1 (IC50 = 0.25 microM) and COX-2 activity (IC50 = 0.15 microM). Ex vivo, a single topical ocular dose of nepafenac (0.1%) inhibited prostaglandin synthesis in the iris/ciliary body (85-95%) and the retina/choroid (55%). These levels of inhibition were sustained for 6 h in the iris/ciliary body and 4 h in the retina/choroid. Diclofenac (0.1%) suppressed iris/ciliary body prostaglandin synthesis (100%) for only 20 min, with 75% recovery observed within 6 h following topical dosing. Diclofenac's inhibition of prostaglandin synthesis in the retina/choroid was minimal. Nepafenac's inhibitory efficacy and longer duration of action was confirmed in a trauma-induced rabbit model of acute ocular inflammation monitoring protein or PGE2 accumulation in aqueous humor. Results warrant further assessment of nepafenac's topical ocular efficacy in the treatment of postoperative ocular pain, inflammation, and posterior segment edema.

Inflammation-mediated retinal edema in the rabbit is inhibited by topical nepafenac.

The purpose of this study was to evaluate the ability of the nonsteroidal anti-inflammatory drug nepafenac to prevent development of mitogen-induced pan-retinal edema following topical ocular application in the rabbit. Anesthetized Dutch Belted rabbits were injected intravitreally (30 microg/20 microL) with the mitogen concanavalin A to induce posterior segment inflammation and thickening (edema) of the retina. The Heidelberg Retina Tomograph was used to generate edema maps using custom software. Blood-retinal barrier breakdown was assessed by determining the protein concentration in vitreous humor, whereas analysis of PGE2 in vitreous humor was performed by radioimmunoassay. Inhibition of concanavalin A-induced retinal edema was assessed 72 h after initiation of topical treatment with nepafenac (0.1-1.0%, w/v), dexamethasone (0.1%), VOLTAREN (0.1%), or ACULAR (0.5%). Concanavalin A elicited marked increases in vitreal protein and PGE2 synthesis at 72 h postinjection. Retinal thickness was also increased by 32%, concomitant with the inflammatory response. Topical application of 0.5% nepafenac produced 65% reduction in retinal edema which was correlated with 62% inhibition of blood-retinal barrier breakdown. In a subsequent study, 0.5% nepafenac significantly inhibited (46%) blood-retinal barrier breakdown concomitant with near total suppression of PGE2 synthesis (96%). Neither Voltaren nor Acular inhibited accumulation of these markers of inflammation in the vitreous when tested in parallel. This study demonstrates that nepafenac exhibits superior pharmacodynamic properties in the posterior segment following topical ocular dosing, suggesting a unique therapeutic potential for a variety of conditions associated with retinal edema.

Transient loss of prostaglandin synthetic capacity in rabbit iris-ciliary body following anterior chamber paracentesis.

The trauma-induced acute ocular inflammatory response has been characterized by investigating the kinetics of blood-aqueous barrier (BAB) breakdown, prostaglandin (PG) accumulation in the aqueous humor, and cyclooxygenase (PGH synthase) activity of the iris-ciliary body (ICB) following paracentesis in the NZA rabbit. BAB breakdown was assessed by quantifying plasma protein extravasation into the anterior chamber. PGE2 and 6-keto-PGF(1alpha) concentrations in the aqueous humor were quantified by radioimmunoassay. The capacity of ICB tissue homogenates to generate eicosanoids from exogenously supplied [I-14C]-arachidonic acid was assessed radiometrically by HPLC. Paracentesis resulted in a rapid and dramatic increase in aqueous humor PGE2 concentrations. Within 10 minutes, PGE2 concentrations increased 937-fold, from 6.2+/-4.9 pg/ml to maximal concentrations of 5810+/-3829 pg/ml. PG synthesis was followed temporally by an increase in aqueous humor protein, with peak levels (53.1 mg/ml) achieved within 30 minutes post paracentesis. Both PGE2 and protein levels gradually declined to near baseline levels 48 hours after trauma. ICB homogenates from naive animals produced significant amounts of eicosanoids (total PG=2.95 nmol/ 10 min/100 mg tissue). HHT (12 hydroxy-heptadecatrienoic acid) was produced in the greatest quantity, followed by PGE2alpha, PGI2, and TXB2/ PGF2 . Notably, following paracentesis, eicosanoid synthesis by the isolated ICB was observed to diminish abruptly. Formation of all eicosanoids was uniformly reduced by approximately 40% five minutes following paracentesis, with an 81% decrease in synthetic activity at 15 minutes. Eicosanoid synthetic capacity was only restored to baseline 48 hours post paracentesis. These findings suggest that, following ocular trauma, temporal changes occur in ICB PG synthetic activity that may impact on the selection of an optimal dosing paradigm for efficacy testing of topically administered NSAIDs.

The in vitro and in vivo ocular pharmacology of olopatadine (AL-4943A), an effective anti-allergic/antihistaminic agent.

Olopatadine (AL-4943A; KW-4679) [(z)-11-[3-(dimethylamino)propylidene]-6, 11-dihydrodibenz[b,e]oxepine-2 acetic acid hydrochloride] is an anti-allergic agent which inhibits mast cell mediator release and possesses histamine H1 receptor antagonist activity. Studies were conducted to characterize the in vitro and in vivo pharmacological profile of this drug relevant to its topical ocular use. AL-4943A inhibits histamine release in a concentration-dependent fashion (IC50 = 559 microM) from human conjunctival mast cell preparations in vitro. Histamine release was not stimulated by AL-4943A at concentrations as high as 10 mM. In contrast, ketotifen stimulated histamine release at concentrations slightly higher than effective inhibitory concentrations. AL-4943A did not display any in vitro cyclooxygenase or 5-lipoxygenase inhibition. Topical ocular application of AL-4943A effectively inhibits antigen- and histamine-stimulated conjunctivitis in guinea pigs. Passive anaphylaxis in guinea pig conjunctiva was attenuated by AL-4943A applied 30 min prior to intravenous or topical ocular antigen challenge (ED50 values 0.0067% and 0.0170%, w/v, respectively). Antihistaminic activity in vivo was demonstrated using a model of histamine-induced vascular permeability in guinea pig conjunctiva. AL-4943A applied topically from 5 min to 24 hrs prior to histamine challenge effectively and concentration-dependently inhibited the vascular permeability response, indicating the compound has an acceptable onset and a long duration of action. Drug concentrations 5-fold greater than those effective against histamine-stimulated conjunctival responses failed to inhibit vascular permeability responses induced with either serotonin or Platelet-Activating-Factor. These data indicate that the anti-histaminic effect observed with AL-4943A is specific. These anti-allergic/antihistaminic activities of AL-4943A observed in preclinical model systems have been confirmed in clinical trials in allergic patients.

Onset of Hemophilus influenzae type-b meningitis during cefaclor therapy for preseptal cellulitis.

Second generation cephalosporins are frequently used for the treatment of bacteremic Hemophilus influenzae type b infections. "Breakthrough" meningitis during cefamandole therapy has documented the need for adequate cerebrospinal fluid penetration by these antibiotics if they are to be used in the therapy of Hemophilus infections. A child with H. influenzae type b preseptal cellulitis is reported who initially responded to treatment with intravenous cefuroxime and oral cefaclor. However, while still receiving cefaclor, the child was readmitted with H. influenzae meningitis. Microtiter broth dilution susceptibility testing performed during the second admission showed the isolate to be relatively resistant to cefuroxime (minimum bactericidal concentration [MBC] = 4 micrograms/ml) and resistant to cefaclor (MBC greater than 16 micrograms/ml). This experience documents the need to monitor the clinical response closely during therapy of H. influenzae bacteremic infections with these second generation cephalosporin treatment regimens. In addition, attention should be paid to minimum inhibitory concentrations of these cephalosporins, since variations in H. influenzae type b susceptibility to these agents may limit their efficacy.

Success inhibitions in neurotic and character-disordered patients.

Freud's initial understanding of "wreckage by success" involved oedipal conflicts. Since that time, preoedipal issues have also been identified as underlying success inhibitions. Work inhibitions in character-disordered patients may be ignored because of our general understanding of how pathological ego and superego functioning interferes in work, as in all areas. However, after significant psychotherapeutic work has been done, the author has often found that such patients have remaining work problems that should be viewed as inhibitions rather than deficits. Separation fears often underlie success inhibitions in more disturbed patients. Careful understanding of work inhibitions in more disturbed patients is crucial, because in many such patients, more freeing of functioning is possible in the work sphere than in intimate relationships. Two cases are presented to illustrate oedipal-level and preoedipal conflicts related to success.