Efficacy of metered-dose inhaler administration of albuterol in intubated infants

STUDY OBJECTIVE

To compare the safety and efficacy of metered-dose inhaler (MDI) albuterol to nebulized (NEB) albuterol administration.

DESIGN

A randomized, triple-blinded, crossover study.

SETTING

A pediatric ICU in a tertiary care children's hospital.

PATIENTS

Eleven intubated infants with bronchiolitis.

INTERVENTIONS

Subjects received four puffs of MDI albuterol (360 microg) and 3 mL of NEB saline solution placebo or 0.3 mL of NEB albuterol (1.5 mg) and MDI saline solution placebo. Each set of albuterol and saline solution placebo was administered after direct attachment of delivery device to the endotracheal tube and bag-valve system. Subjects received the opposite sequence 4 h after the initial sequence. The second sequence was given first the next day, and the first sequence was administered 4 h later.

MEASUREMENTS AND RESULTS

Respiratory system compliance and resistance were measured at baseline and 30 min, 1 h, 2 h, and 4 h after each set of placebo and albuterol. There was an appreciable improvement in compliance and resistance for up to 2 h following both methods of administration. However, the degree of improvement was not significantly different (p>0.05) between the two methods. Neither method caused a significant change in resistance when measured at 4 h after albuterol/placebo administration. No evidence of toxicity was detected.

CONCLUSIONS

MDI-administered albuterol is as safe and efficacious as nebulized-administered albuterol in intubated infants with bronchiolitis. Generalizability of these results is limited by differences in drug delivery with different brands of nebulizers and spacers and sites of attachment.

Standardization of an opsonophagocytic assay for the measurement of functional antibody activity against Streptococcus pneumoniae using differentiated HL-60 cells

Host protection against pneumococcal disease i primarily mediated by phagocytosis. We developed and standardized an opsonophagocytic assay using HL-60 cells (human promyelocytic leukemia cells). Fifty-five serum samples were analyzed for the presence of functional antibody against seven pneumococcal serogroups or serotypes (4, 6B, 9V, 14, 18C, 19F, and 23F) by using differentiated HL-60 cells (granulocytes) and peripheral blood leukocytes (PBLs). Six of the 55 serum samples were from unvaccinated adult volunteers, 31 serum samples were from adults who received one dose of the 14-valent or the 23-valent polysaccharide vaccine, and 18 serum samples were from 16-month-old infants who received four doses of an investigational 7-valent polysaccharide-protein conjugate vaccine. The results of an opsonophagocytic assay with HL-60 cells correlated highly with those of an assay with PBLs as effector cells (median r for seven serotypes = 0.87: P < 0.01). Opsonophagocytic titers were compared with the immunoglobulin G antibody concentrations determined by enzyme-linked immunosorbent assay (ELISA). The r values for serogroups or serotypes 4, 6B, 9V, 14, 18C, 19F, and 23F were 0.61, 0.60, 0.67 0.90, 0.61, 0.39, and 0.57, respectively, when HL-60 cells were used as effector cells and 0.56, 0.47, 0.61, 0.90, 0.71, 0.31, and 0.62, respectively, when PBLs were used. The assay requires small amounts of serum (40 microliters per serotype), making this test suitable for assaying infant sera. Culturable cells aid in assay standardization and likely reduce donor-to-donor variability. This standardized assay, in combination with the standardized ELISA, can be used to evaluate current and developing pneumococcal vaccines, in which functional opsonophagocytic antibody activity may correlate with protection against pneumococcal disease.

Cardiovascular risk factors in homeless adults

Homelessness is a growing problem in the United States, with population numbers ranging from 300,000 to several million. This article reviews five studies that focused on identification and assessment of cardiovascular risk factors in the homeless population. A case study presents the successful outcome of a homeless male with several risk factors. Assessment and intervention by a nurse practitioner led to his re-entry into the domiciled population. Implications for clinical practice and recommendations for further research are discussed.

Management of impalpable testes: indications for abdominal exploration

Various approaches to the management of the impalpable testis in cases of cryptorchidism have been advocated. The authors' experience over the past 13 years was reviewed to try to determine an optimal approach. Of 1,305 patients with undescended testicles seen between February 1982 and December 1995, 157 boys (12.03%) had impalpable testes with 17 having bilateral impalpable testes for a total of 174 impalpable testes. A hernia sac was present in 155 impalpable testes with a testicle present in all cases. No hernia sac was found in 19 impalpable testes, five of which had no testicle present. This was confirmed by either open exploration or laparoscopy. One hundred forty-eight boys underwent groin exploration as initial treatment, 13 of these had bilateral impalpable testes. In addition to the five absent testicles with no hernia sac, one patient with a hernia sac and no testicle evident benefited from subsequent laparoscopy to identify an intraabdominal testicle. All other patients underwent routine orchidopexy or orchidectomy (one case with grossly malformed testicle). Nine boys underwent laparoscopy as initial treatment, four of these had bilateral impalpable testes. Two abnormal testicles were found and removed. Groin exploration and subsequent orchidopexy was definitive treatment in all other cases. The association of a hernia sac with an impalpable undescended testicle is very significant (P < .00001 Fisher's Exact test). The absence of a sac therefore may reflect an alternate diagnosis. When no sac is found with a testicle in the groin, this may represent an ectopic testicle. When no sac is found with no testicle, this may represent a vanishing testicle. From this experience the authors conclude that groin exploration should be the initial approach to impalpable testes. The presence of a hernia sac with an absent testicle demands further exploration; the absence of a hernia sac with an absent testicle suggests a vanishing testicle and may need no further exploration.

Team-based participation in the hiring process

In most health care settings today, effective patient service results from medical staff members working together as a high performance team. These teams evolve through the process of hiring employees who combine the necessary technical skills, knowledge, and abilities (SKAs) to perform the job and whose interpersonal attributes will add value to services provided by the team. This article promotes the concept that those who are in the best position to determine whether a job candidate will become a productive team member are, in most cases, the team members themselves. Discussion includes types of teams and degree of member involvement. For those health care professionals interested in using greater team-based participation in employment matters, specific advantages and realistic challenges are provided.

Determination of albuterol in plasma after aerosol inhalation by gas chromatography-mass spectrometry with selected-ion monitoring

Albuterol is a beta2-adrenergic agonist commonly used as a bronchodilator for the treatment of patients with asthma. We have developed an assay to determine plasma levels as low as 50 pg/ml of albuterol by gas chromatography-mass spectrometry (GC-MS). This assay utilizes isotopically labeled albuterol ([13C]albuterol) as an internal standard. In this assay albuterol and the internal standard are recovered from 1 ml of plasma using solid-phase extraction. The samples are then derivatized to trimethylsilyl ethers using N,O-bis(trimethylsilyl)trifluoro-acetamide with 1% trimethylchlorosilane. The samples are then analyzed by GC-MS with selected-ion monitoring (SIM) for the ions m/z 369.15 and 370.15. The method has been validated for a concentration range of 50-10000 pg/ml in plasma.

Cytotoxicity and apoptosis in human renal allografts: identification, distribution, and quantitation of cells with a cytotoxic granule protein GMP-17 (TIA-1) and cells with fragmented nuclear DNA

In the present study, we analyzed human renal allografts using immunohistochemical techniques to determine the site, identity, and frequency of (a) cytotoxic and apoptotic cells, as identified by staining for GMP-17 (TIA-1), a component of cytotoxic granules; and (b) DNA fragmentation in situ, as detected by the TUNEL method. In acute cellular rejection (n = 15), GMP-17+ mononuclear cells accounted for 29% +/- 12% of the infiltrating cells in the interstitium (341 +/- 164/mm2) and were significantly more concentrated in tubulitis lesions, where they amounted to 65% +/- 14% of the mononuclear cells (96 +/- 61/mm2) (p < 0.01 versus interstitium). GMP-17+ mononuclear cells were also found in sites of endothelialitis. An estimated 80% of the GMP-17+ lymphocytes expressed CD8, and 10% to 20% expressed either CD4 or the macrophage marker CD14. The latter finding led us to analyze normal peripheral blood monocytes by flow cytometry, all of which were found to contain GMP-17. NK cells and neutrophils, which are known to express GMP-17, were detected only rarely in allografts. Specimens with cyclosporine A toxicity (n = 7) or acute tubular necrosis (n = 13) showed fewer GMP-17+ cells in the interstitium (22 +/- 46/mm2 and 62 +/- 50/mm2, respectively) and tubules (2 +/- 6/mm2 and 10 +/- 10/mm2, respectively) (all p < 0.01 versus rejection). These differences were due largely to less intense mononuclear cell infiltration. In cyclosporine A toxicity, however, the percentages of GMP-17+ mononuclear cells within tubules and the interstitium were significantly lower than in rejection (p = 0.02), whereas in acute tubular necrosis significantly lower percentages were found in the tubules (p = 0.04) but not in the interstitium. Native kidneys with end-stage diabetic nephropathy (n = 5) had very low proportions of GMP-17+ cells in interstitial infiltrates (7% +/- 6%) and in tubules (11% +/- 15%), although the infiltrates were focally intense (517 +/- 355/mm2). TUNEL+ cells were found in acute cellular rejection, predominantly in areas with intense mononuclear infiltrates and also within lesions of tubulitis and endothelialitis. Although some TUNEL+ cells were intrinsic renal cells, most appeared to be infiltrating mononuclear cells, and we were able to detect CD3 in some. In areas of intense cellular infiltration, the percentages of TUNEL+ cells (range, 0.5% to 4.2%) were comparable to those seen in the rat thymus, indicating a high level of apoptosis. Overall, in the allograft samples, the numbers of GMP-17+ cells and TUNEL+ cells were significantly correlated (r = 0.79; p < 0.01). These data provide new evidence that T cell (and possibly macrophage)-mediated cytotoxicity plays an important role in acute renal allograft rejection, particularly in the case of tubular injury, and furthermore suggest that apoptosis may be a mechanism not only for graft cell destruction, but also for elimination of activated T cells in the infiltrate.

Life and death in the cytoplasm: messages from the 3' end

The cytoplasmic life of an mRNA revolves around the regulation of its localization, translation and stability. Interactions between the two ends of the mRNA may integrate translation and mRNA turnover. Regulatory elements in the region between the termination codon and poly(A) tail - the 3' untranslated region - have been identified in a wide variety of systems, as have been some of the key players with which these elements interact.

Proteins phosphorylated during stress-induced apoptosis are common targets for autoantibody production in patients with systemic lupus erythematosus

Proteins cleaved by interleukin-1 beta converting enzyme family proteases during apoptosis are common targets for autoantibody production in patients with systemic lupus erythematosus (SLE). We have tested the possibility that proteins phosphorylated in cells undergoing apoptosis are also targets for autoantibody production in patients with autoimmune disease. Sera from 9/12 patients containing antinuclear antibodies (10/12 meeting diagnostic criteria for SLE or a lupus overlap syndrome), precipitated new phosphoproteins from lysates derived from Jurkat T cells treated with apoptotic stimuli (i.e., Fas-ligation, gamma irradiation, ultraviolet irradiation), but not with an activation (i.e., CD3-ligation) stimulus. Sera derived from individual patients precipitated different combinations of seven distinct serine-phosphorylated proteins. None of these phosphoproteins were included in precipitates prepared using sera from patients with diseases that are not associated with autoantibody production or using serum from rheumatoid arthritis patients. Protein phosphorylation precedes, or is coincident with, the induction of DNA fragmentation, and is not observed when apoptosis is inhibited by overexpression of bcl-2. Serum from four patients precipitated a serine/threonine kinase from apoptotic cell lysates that phosphorylates proteins of 23-, 34-, and 46-kD in in vitro kinase assays. Our results suggest that proteins phosphorylated during apoptosis may be preferred targets for autoantibody production in patients with SLE.

Kinase cascades regulating entry into apoptosis

All cells are constantly exposed to conflicting environment cues that signal cell survival or cell death. Survival signals are delivered by autocrine or paracrine factors that actively suppress a default death pathway. In addition to survival factor withdrawal, cell death can be triggered by environmental stresses such as heat, UV light, and hyperosmolarity or by dedicated death receptors (e.g., FAS/APO-1 and tumor necrosis factor [TNF] receptors) that are counterparts of growth factor or survival receptors at the cell surface. One of the ways that cells integrate conflicting exogenous stimuli is by phosphorylation (or dephosphorylation) of cellular constituents by interacting cascades of serine/threonine and tyrosine protein kinases (and phosphatases). Survival factors (e.g., growth factors and mitogens) activate receptor tyrosine kinases and selected mitogen-activated, cyclin-dependent, lipid-activated, nucleic acid-dependent, and cyclic AMP-dependent kinases to promote cell survival and proliferation, whereas environmental stress (or death factors such as FAS/APO-1 ligand and TNF-alpha) activates different members of these kinase families to inhibit cell growth and, under some circumstances, promote apoptotic cell death. Because individual kinase cascades can interact with one another, they are able to integrate conflicting exogenous stimuli and provide a link between cell surface receptors and the biochemical pathways leading to cell proliferation or cell death.

Health, Society and Alcohol

The European Conference, Health, Society and Alcohol held in Paris, 12-14 December 1995, was a meeting point between science and policy. Science informed the policy process. As a tool for policy implementation, the Conference adopted the European Charter on Alcohol, a set of ethical principles and strategies for action. Of a number of important issues that frame policy, three deserve mention. First, market forces, as opposed to health and social policy decisions are increasingly influencing the policy debate. Second, existing policy options to reduce alcohol-related harm are unlikely to lead to an increased risk of coronary heart disease among older age groups. And third, policy developments and changes in drinking patterns in countries of southern Europe are an important driving force in European policy on alcohol.

Charcot spine as a late complication of traumatic spinal cord injury

Charcot spine, also known as neuropathic spinal arthropathy, is a late complication of traumatic spinal cord injury that can produce pain and further disability. We report five cases of Charcot spine occurring in patients with previous traumatic spinal cord injury that we have identified at our institution from 1985 to 1994. All patients had complete paraplegia with levels of neurologic injury ranging from T7 to T12. Common presenting symptoms included back pain, loss of spasticity, change in bladder function, and audible noises with motion. The diagnosis of Charcot spine was made from 6 to 31 years after original spinal cord injury. In four cases where a surgical fusion had been performed, the Charcot joint developed within two spinal segments below the caudal end of the fusion. Radiological studies, especially plain films and computed tomography, were helpful in making the diagnoses. Immobilization of the affected joint is an essential element of treatment. Surgical repair and stabilization were performed in four patients and has been recommended to the other patient. Early diagnosis and proper treatment is important in preventing the progression of this disorder.

Advances in the molecular genetic analysis of the flax-flax rust interaction

The L6 and M rust-resistance genes, representing two of the five rust-resistance gene loci in flax (Linum usitatissimum), have been cloned. The molecular data are fully consistent with earlier genetic data: the L locus is a single gene with multiple alleles expressing different rust resistance specificities, and the M locus is complex, containing an array of about 15 similar genes. Thus, while L6 and M resistance genes have 86% nucleotide identity, their locus structure is very different. These genes encode products belonging to the nucleotide binding site-leucine-rich repeat class of disease-resistance proteins. Analysis of alleles from the L locus and chimeric genes is providing evidence suggesting that important specificity determinants occur in the C-terminal half of the proteins, the region containing the leucine-rich repeats. The isolation and characterization of the rust (Melampsora lini) avirulence genes that correspond to the cloned rust-resistance genes is one of the major challenges remaining to the understanding of this system.

The 1996 Albert Lasker Medical Research Awards. Prevention of systemic infections, especially meningitis, caused by Haemophilus influenzae type b. Impact on public health and implications for other polysaccharide-based vaccines

The development of Haemophilus influenzae type b (Hib) conjugate vaccines has led to the virtual elimination of systemic infections caused by that pathogen, has provided insights into the pathogenesis of and immunity to other capsulated bacteria, and has contributed to the development of new vaccines. Meningitis, a common and serious infection of children, and other infections caused by Hib have been virtually eliminated in countries that have achieved widespread vaccination with Hib conjugates, including the United States, Canada, the United Kingdom, Iceland, Scandinavia, France, and Germany. Hib conjugates have also been shown to be highly effective in developing countries. The principles derived from the use of these vaccines, along with studies of other capsulated pathogens, should allow the rapid inclusion of new polysaccharide-based conjugates into routine vaccination schedules of infants, and should help to realize further reductions in serious systemic infectious diseases.

Structure, tissue distribution and genomic organization of the murine RRM-type RNA binding proteins TIA-1 and TIAR

TIA-1 and TIAR are RNA binding proteins of the RNA recognition motif (RRM)/ribonucleoprotein (RNP) family that have been implicated as effectors of apoptotic cell death. We report the structures of murine TIA-1 and TIAR (mTIA-1 and mTIAR) deduced from cDNA cloning, the mRNA and protein tissue distribution of mTIA-1 and mTIAR, and the exon-intron structures of the mTIA-1 and mTIAR genes. Both mTIA-1 and mTIAR are comprised of three approximately 100 amino acid N-terminal RRM domains and a approximately 90 amino acid C-terminal auxiliary domain. This subfamily of RRM proteins is evolutionarily well conserved; mTIA-1 and mTIAR are 80% similar to each other, and 96 and 99% similar to hTIA-1 and hTIAR, respectively. The overall exon-intron structures of the mTIA-1 and mTIAR genes are also similar to each other, as well as to the human TIA-1 gene structure. While Northern blot analysis reveals that mTIA-1 and mTIAR mRNAs have a broad tissue distribution, mTIA-1 and mTIAR proteins are predominantly expressed in brain, testis and spleen. At least two isoforms of both mTIA-1 and mTIAR are generated by alternative splicing. Murine TIA-1 isoforms including or lacking the exon 5 encoded sequences are expressed at a ratio of approximately 1:1, whereas mTIAR isoforms including or lacking the 5'-end of exon 3 sequences are expressed in a approximately 1:6 ratio. Molecular characterization of murine TIA-1 and TIAR RNA binding proteins provides the basis for a genetic analysis of the functional roles of these proteins during mammalian development.

Psychosocial and family functioning in children with insulin-dependent diabetes at diagnosis and one year later

Examined the initial impact and subsequent adjustment to the diagnosis of insulin-dependent diabetes mellitus (IDDM). Children between 1 and 14 years of age and their families were assessed several weeks after diagnosis and again a year later using standardized measures of child behavior, parental mental health, and family functioning. Immediately after diagnosis, the children and both parents exhibited mild symptoms of psychological distress but these had largely resolved at 12-month follow-up. The impact of IDDM diagnosis on family functioning varied with informant, SES, and the age of the child, with an overall tendency for families to become less flexible over the year. Findings suggest that most children and their parents exhibit satisfactory individual adjustment after a period of initial stress but family functioning is affected in complex ways. Serial follow-up of the cohort is planned to establish whether the current findings are predictive of longer term outcome.

G proteins are required for spatial orientation of early cell cleavages in C. elegans embryos

Heterotrimeric G proteins are signal-transducing molecules activated by seven transmembrane domain receptors. In C. elegans, gpb-1 encodes the sole Gbeta subunit; therefore, its inactivation should affect all heterotrimeric G protein signaling. When maternal but no zygotic gpb-1 protein (GPB-1) is present, development proceeds until the first larval stage, but these larvae show little muscle activity and die soon after hatching. When, however, the maternal contribution of GPB-1 is also reduced, spindle orientations in early cell divisions are randomized. Cell positions in these embryos are consequently abnormal, and the embryos die with the normal number of cells and well-differentiated but abnormally distributed tissues. These results indicate that maternal G proteins are important for orientation of early cell division axes, possibly by coupling a membrane signal to centrosome position.