Asthma pharmacotherapy and utilization by children in 3 managed care organizations. The Pediatric Asthma Care Patient Outcomes Research Team

BACKGROUND: Asthma is the most common chronic disease among children and the most frequent cause of hospitalization. Appropriate pharmacotherapy is a cornerstone of published national guidelines for the care of children with asthma. OBJECTIVE: The goal was to compare the baseline pharmacotherapy and health care utilization from 1996 to 1997 in children with asthma at managed care organizations (MCOs). METHODS: A common protocol was used to extract the study sample from 3 MCOs with automated claims and pharmacy databases. Children were selected if they were 3 to 15 years old as of June 1997 with 1 or more encounters (outpatient, emergency department visit, hospitalization) with an asthma diagnosis in the previous year. RESULTS: Of the 13,352 children studied, less than 40% were given controllers during the 12-month interval, with ranges of 15% to 77% by level of bronchodilator use, 31% to 44% by age, and 38% to 42% by MCO. Among children given 6 or more bronchodilators, controller dispensing ranged from 73% to 89% among the 3 MCOs. Variability was most evident for inhaled corticosteroids, for which dispensing ranged from 51% to 70%. Rates of asthma hospitalization and emergency department visits also differed among the MCOs, ranging from 21 to 37 per 1000 person-years and 37 to 142 per 1000 person-years, respectively. CONCLUSION: Five years after dissemination of national guidelines for care, the pattern of asthma therapy does not reflect guideline recommendations. Variation among health care organizations with respect to asthma therapy and utilization of health services exists. In addition, controller medications may not be used by all children who could benefit from them.     

Sister chromatid exchange: Variation by age,sex, smoking,and breast cancer status

Variation in sister chromatid exchange (SCE) frequency in lymphocytes of 125 persons was compared using a multivariate general linear model. The study was performed to determine whether SCE frequency differs with respect to age, sex, smoking, and breast cancer status. Study subjects were divided into: members of two branches of families having an excess of cancer (primarily breast) including a brother and sister in one family who developed nonbreast malignancies within 1 yr of the study; women in both families successfully treated for breast cancer (all at least 5 yr posttreatment); and women from the general population with confirmed breast cancer.Controls consisted of spouses who married into the high-risk kindreds, hospital personnel, and others (primarily tradesmen without history of occupational exposure). Results show that: (1) Women with active breast cancer have a significantly higher mean SCE frequency than control women or women greater than 5 yr posttreatment for breast cancer; (2) Cigarette smokers show a significantly higher number of SCEs than was observed in nonsmokers; (3) The increase in SCE level in smokers is dose-related to exposure as measured by cumulative pack-years; (4) SCE values in both high-risk families are not significantly different from controls; (5) Neither the age nor sex of the individual affects SCE frequency; and (6) The observed distribution of exchanges agrees with that expected based on the proportion of the genome represented by each chromosome group.     

Needle biopsy of renal allografts: comparison of two techniques

Two techniques for renal allograft biopsy were retrospectively evaluated to compare relative safety and efficacy. After ultrasound (US) localization of the kidney and biopsy with a hand-held 14-gauge cutting needle, an adequate specimen was obtained in 74 of 77 cases (96%). Major complications occurred in six of these 77 cases (8%). One hundred four biopsies were performed by using a smaller 18-gauge cutting needle with a spring-loaded biopsy "gun" and real-time US guidance. With this newer technique, specimens adequate for diagnosis were obtained in 99 biopsies (95%). There was a single major complication with this technique (1%). The 18-gauge needle with real-time US guidance yields comparably adequate specimens with a lower frequency of complications.     

Determinants of improved outcome in small-cell lung cancer: an analysis of the 2,580-patient Southwest Oncology Group data base

We analyzed the 2,580-patient Southwest Oncology Group (SWOG) small-cell lung cancer data base from 1976 to 1988 in order to (1) determine the prognostic value of favorable demographic and tumor-related factors and therapy programs using Cox multivariate analyses in limited- and extensive-stage disease (LD, ED), and (2) define patient subgroups with significantly different survivals using recursive partitioning and amalgamation (RPA) analysis to refine the current two-stage system. Cox multivariate models were applied to 1,363 patients in six LD trials: good performance status, female sex, age less than 70 years, white race, and normal lactate dehydrogenase (LDH) were significant favorable independent predictors. Concurrent chemoradiotherapy was also a strong independent predictor of survival. For 1,217 patients in four ED trials, a normal LDH, treatment with an intensive multidrug regimen, and a single metastatic lesion were favorable independent variables in the Cox model. RPA analysis of 1,137 patients in recent LD and ED trials resulted in a regression tree in which the most important prognostic split was LD versus ED. Normal or abnormal LDH, absence or presence of a pleural effusion, and age less than 70 or greater than or equal to 70 years were important in LD, but only LDH was significant in ED. The terminal nodes of the regression tree were amalgamated to form four distinct prognostic subgroups with median survivals of 19.0, 12.5, 10.5, and 6.3 months (P less than .0001). The best survival occurred for younger patients with "true" LD: no effusion and normal LDH. The two intermediate patient subgroups had either LD or ED but still lived significantly longer than those patients with true ED (elevated LDH). This analysis suggests that although several factors were independent prognostic variables in LD in the Cox models, a smaller number of variables can be used to form important prognostic subgroups through RPA. The LDH emerged as a highly significant factor, but performance status and sex did not. A refinement of the current staging system should be made if our results can be confirmed with a combined-group data base analysis.     

Antibodies to CD18 influence neutrophil migration through extracellular matrix

Mac-1 (CD11b/CD18) is known to be involved in neutrophil (PMN) adhesion to endothelial cells and extracellular matrix. Although antibodies to CD 18 are being tested for therapy in humans, their role in PMN migration through the extracellular matrix is unknown. We used direct visualization to quantify PMN motility through reconstituted, three-dimensional gels of collagen type I. Gels were prepared with different concentrations of collagen (ranging from 0.1 to 1.0 mg/mL) and PMN migration was examined in the presence and absence of antibodies to CD18 (anti-CD18), with and without stimulation by N-formyl peptides. In low-concentration gels (<0.6 mg/mL), anti-CD18 had a significant influence on PMN migration, increasing motility in unstimulated PMN by 90% at 0.3 mg/mL collagen, and decreasing motility in N-formyl-methionyl-leucyl-phenylalanine (fMLP)-stimulated PMN by 70% at 0.4 mg/mL collagen. But antiCD18 had no effect on the rate of cell migration through high-concentration collagen gels (>0.6 mg/mL). PMN migration through collagen gels is CD18-dependent but only under conditions of high hydration, suggesting that CD18-mediated effects (e.g., adhesion to gel fibers) are only important when the fiber density is relatively low. Anti-CD18 inhibited, but did not eliminate, the adhesion of fMLP-stimulated PMN to the surface of collagen gels, suggesting that cells use multiple mechanisms for gaining traction within the gel. Because of the multiple modes of interaction between motile cells and the deformable fiber matrix, blockade of one component, such as CD18, can enhance the rate of cell migration under one set of conditions, and inhibit under another.     

Priming of neutrophil [Ca2+]i signaling and oxidative burst by human fracture fluids

BACKGROUND: Patients with major fracture/soft-tissue injuries are at risk for adult respiratory distress syndrome after secondary infection. Fracture fluids (FF) are rich in neutrophil (PMN) -specific chemokines such as interleukin-8. PMN respond to both interleukin-8 and bacterial stimuli with calcium ([Ca2+]i) fluxes, which can initiate respiratory burst (RB). We hypothesize that small amounts of FF entering the circulation could exaggerate PMN [Ca2+]i and RB responses, potentially increasing the risk of adult respiratory distress syndrome. METHODS: FF were obtained from 10 patients at open fixation of the femur 2 to 5 days postinjury. Volunteer PMN were isolated and loaded with fura dye. PMN were preincubated either in 30% autologous plasma (AP)/70% buffer, or in 5% FF/25% AP/70% buffer. Cells were resuspended in buffer with 1,2,3-dihydrorhodamine and stimulated with low-dose n-formyl-methionyl-leucyl-phenylalanine (fMLP). [Ca2+]i was assayed by fura fluorescence at 505 nm after excitation at 340/380 nm. RB was assessed by 1,2,3-dihydrorhodamine fluorescence at 530 nm after 488 nm excitation. RESULTS: PMN basal [Ca2+]i was higher after FF incubation than AP incubation (94+/-12 vs. 61+/-9 nmol/L, p = 0.0002). Peak [Ca2+]i response to fMLP was 475+/-47 nmol/L after FF but only 356+/-22 nmol/L after AP (p = 0.01). Two hundred seconds after fMLP, [Ca2+]i remained higher after FF (172+/-17 vs. 145+/-9 nmol/L, p = 0.04). Basal RB was slightly higher after FF than AP (13.4+/-0.3 vs. 11.3+/-0.3 units, p = 0.051) as was the maximal rate of extracellular oxidant release (1.10+/-0.17 vs. 0.76+/-0.16 units/s, p = 0.004) and total oxidant production (42.5+/-0.8 vs. 31.7+/-0.8 units, p = 0.006). CONCLUSION: Small amounts of FF in plasma can exaggerate PMN [Ca2+]i flux and RB responses to subsequent bacterial stimuli. These findings are consistent with the hypothesis that release of FF into the circulation primes PMN and, thus, may predispose to adult respiratory distress syndrome. Such PMN priming events might have important implications for both the operative and medical management of patients with major fractures.     

Comparison of the effect of different immunological adjuvants on the antibody and T-cell response to immunization with MUC1-KLH and GD3-KLH conjugate cancer vaccines.

While the importance of immunological adjuvants for optimal induction of antibody and T-cell responses against tumor antigens is clear, the relevant potency of different adjuvants is not clear. We have screened 19 different immunological adjuvants with KLH conjugate vaccines containing the two human cancer antigens (MUC1 peptide and GD3 ganglioside) in the mouse. ELISA assays for IgM and IgG antibody responses as well as proliferation and cytokine release (IFN-gamma and IL-4) for T-cell responses were performed. Six adjuvants stood out as being especially effective for induction of IgM and IgG antibodies against both MUC1 and GD3: QS-21, TiterMax, MoGM-CSF, MPL/DETOX and CpG ODN. Of these QS-21, MPL/DETOX and MoGM-CSF were uniformly effective at inducing potent proliferation and potent IFN-gamma and IL-4 responses against KLH while TiterMax and CpG ODN generated potent IFN-gamma responses but less potent proliferation or IL-4 release. Overall, as in our previous experience, QS-21 was the most effective adjuvant. There was no clear evidence for induction of T-cell immunity against either GD3 or MUC1 with any of the adjuvants. There was a strong correlation between the antibodies induced against MUC1 and GD3 with different immunological adjuvants and the strength of the IFN-gamma release against KLH. This suggests that the primary role of adjuvants in the context of these conjugate vaccines may be induction of higher levels of T-cell immunity against KLH, which then leads to higher levels antibody against the conjugated antigens.     

Proceedings of the Symposium ‘Angiotensin AT1 Receptors: From Molecular Physiology to Therapeutics’: PHYSIOLOGICAL ACTIONS OF ANGIOTENSIN II MEDIATED BY AT1 AND AT2 RECEPTORS IN THE BRAIN

• 1 Autoradiographic binding studies have shown that the AT₁ receptor is the predominant angiotensin II (AngII) receptor subtype in the central nervous system (CNS). Major sites of AT₁ receptors are the lamina terminalis, hypothalamic paraventricular nucleus, the lateral parabrachial nucleus, rostral and caudal ventrolateral medulla, nucleus of the solitary tract and the intermediolateral cell column of the thoraco-lumbar spinal cord.
• 2 While there are differences between species, AT₂ receptors are found mainly in the cerebellum, inferior olive and locus coeruleus of the rat.
• 3 Circulating AngII acts on AT₁ receptors in the subfornical organ and organum vasculosum of the lamina terminalis (OVLT) to stimulate neurons that may have a role in initiating water drinking.
• 4 Centrally administered AngII may act on AT₁ receptors in the median preoptic nucleus and elsewhere to induce drinking, sodium appetite, a sympathetic vasoconstrictor response and vasopressin secretion.
• 5 Recent evidence shows that centrally administered AT₁ antagonists inhibit dipsogenic, natriuretic, pressor and vasopressin secretory responses to intracerebroventricular infusion of hypertonic saline. This suggests that an angiotensinergic neural pathway has a role in osmoregulatory responses.
• 6 Central angiotensinergic pathways which include neural inputs to the rostral ventrolateral medulla may use AT₁ receptors and play a role in the function of sympathetic pathways maintaining arterial pressure.