Responses to weight loss treatment among obese individuals with and without BED: a matched-study meta-analysis

The moderating influence of binge eating status on obese individuals' responses to weight loss treatment was evaluated with a meta-analysis of 36 tests of weight loss treatment (n=792) that were matched to control key background variables. After controlling for pre-treatment weight, treatment produced more weight loss in samples of obese non-BED compared with obese BED participants. Weight loss treatment produced large posttreatment reductions in depression in both obese BED and non-BED samples. The results indicate that BED status moderated post-treatment weight loss among people in weight treatment programs. Obese BED (average weight loss=1.3 kg) samples lost negligible weight compared to obese non-BED (average weight loss=10.5 kg) samples. BED status did not moderate psychological responses to treatment: both BED and non-BED samples experienced large post-treatment reductions in depression. The clinical implications of these findings are discussed.

A nationwide survey of financing health-related services for special education students

The Individuals with Disability Education Act (IDEA) requires state educational systems to provide school-based, health related services (RS). This survey determined the financing arrangements used by states for health-related services for school-aged children with disabilities. A survey was sent to directors of special education, Medicaid, and public health departments in each of the 50 states. Financial patterns for RS were sought at the state level for children ages 3-21 with disabilities for the 1993-1994 school year, the most recent year for which complete financial data were available. Univariate analyses probed the relationship between systems' variables and the extent of Medicaid usage by local education agencies. Respondents reported that schools tapped traditional health resources to supplement educational dollars in paying for related services in schools. Medicaid was by far the most common source with 29 states reporting established mechanisms for recouping Medicaid dollars and 10 states reporting phase-in activities. Seventeen states reported that departments of public health played some role in administration, training, and demonstrations, but only six states provided specific dollars for related services through the department. Use of private insurance was reported sporadically with only one state indicating a specific state-level program. Correlates of increased Medicaid usage were presence of interagency agreements (IAAs) (OR 11.1, p = 0.002), having specific personnel for school-based medical assistance (OR 17.7, p = 0.001), and utilizing school nursing services as a Medicaid optional service (OR 4.2, p = 0.048).

Parallel evolution of glucosinolate biosynthesis inferred from congruent nuclear and plastid gene phylogenies

The phytochemical system of mustard-oil glucosides (glucosinolates) accompanied by the hydrolytic enzyme myrosinase (beta-thioglucosidase), the latter usually compartmented in special myrosin cells, characterizes plants in 16 families of angiosperms. Traditional classifications place these taxa in many separate orders and thus imply multiple convergences in the origin of this chemical defense system. DNA sequencing of the chloroplast rbcL gene for representatives of all 16 families and several putative relatives, with phylogenetic analyses by parsimony and maximum likelihood methods, demonstrated instead a single major clade of mustard-oil plants and one phylogenetic outlier. In a further independent test, DNA sequencing of the nuclear 18S ribosomal RNA gene for all these exemplars has yielded the same result, a major mustard-oil clade of 15 families (Akaniaceae, Bataceae, Brassicaceae, Bretschneideraceae, Capparaceae, Caricaceae, Gyrostemonaceae, Koeberliniaceae, Limnanthaceae, Moringaceae, Pentadiplandraceae, Resedaceae, Salvadoraceae, Tovariaceae, and Tropaeolaceae) and one outlier, the genus Drypetes, traditionally placed in Euphorbiaceae. Concatenating the two gene sequences (for a total of 3254 nucleotides) in a data set for 33 taxa, we obtain robust support for this finding of parallel origins of glucosinolate biosynthesis. From likely cyanogenic ancestors, the "mustard oil bomb" was invented twice.

Respiratory muscle reserve in rats during heavy exercise

The extent to which the respiratory pump muscles limit maximal aerobic capacity in quadrupeds is not entirely clear. To examine the effect of reduced respiratory muscle reserve on aerobic capacity, whole body peak oxygen consumption (VO2 peak) was measured in healthy Sprague-Dawley rats before and after Sham, unilateral, or bilateral hemidiaphragm denervation (Dnv) surgery. VO2 peak was determined by using a graded treadmill running test. Hemidiaphragm paralysis was verified after testing by recording the absence of electromyographic activity during inspiration. Before surgery, VO2 peak averaged 86, 87, and 92 ml . kg-1 . min-1 for the Sham, unilateral, and bilateral Dnv groups, respectively. Two weeks after surgery, there was no significant change in VO2 peak for either the Sham or unilateral Dnv group. However, VO2 peak decreased approximately 19% in the bilateral Dnv group 2 wk after surgery. These findings strongly suggest that the pulmonary system in rats is designed such that during heavy exercise, the remaining respiratory pump muscles are able to compensate for the loss of one hemidiaphragm, but not of both.

Pediatric guidelines: help or hindrance?

Guidelines are an increasingly prominent part of the practice of pediatrics. Aiming from studies of variability in care, they are widely used as a mechanism to assess and improve quality. Rigorous methods of guideline development differentiate current guidelines from past consensus efforts. The American Academy of Pediatrics has been active in developing and publishing guidelines for common problems, including asthma, hyperbilirubinemia, febrile seizures, gastroenteritis, and, together with the Agency for Health Care Policy and Research and others, otitis media with effusion. Although strategies for how to use guidelines to improve care are increasingly well designed, whether these guidelines will indeed change practice or improve outcomes has yet to be determined.

Comparison of the coated-vesicle and synaptic-vesicle vacuolar (H+)-ATPases

The V-ATPases are a novel class of ATP-dependent proton pumps responsible for acidification of intracellular compartments in eukaryotic cells. They play an important role in receptor-mediated endocytosis, intracellular membrane traffic, macromolecular processing and degradation and coupled transport, as well as functioning in the plasma membrane of certain specialized cell types. The V-ATPases are multisubunit complexes that are organized into a peripheral V1 complex responsible for ATP hydrolysis and an integral V0 domain responsible for proton translocation. Regulation of vacuolar acidification is critical to its role in membrane traffic and other cellular processes. We are currently investigating several mechanisms of regulation of vacuolar acidification, including disulfide bond formation between cysteine residues located at the catalytic site, control of assembly of the peripheral and integral domains, and differential targeting of V-ATPases to different intracellular destinations using their interaction with organelle-specific adaptin complexes.

Failure of granulocyte-macrophage colony-stimulating factor to reduce febrile neutropenia in children with recurrent solid tumors treated with ifosfamide, carboplatin, and etoposide chemotherapy

Ifosfamide, carboplatin, and etoposide (ICE) chemotherapy has promising activity against various solid tumors but produces significant myelotoxicity that might be ameliorated by hematopoietic growth factors. Twelve patients with relapsed solid tumors were treated with ICE chemotherapy. Carboplatin was given on day 1 at a targeted area under the concentration-time curve (AUC) of 8 mg/mL x min (adjusted for each patient's glomerular filtration rate), followed by ifosfamide 2 g/m2 and etoposide 100 mg/m2 on days 2 through 4. Granulocyte-macrophage colony-stimulating factor (GM-CSF), 1,000 micrograms/m2/day, was started 24 hours after each course and given for 17 days or until the absolute neutrophil count (ANC) reached 10 x 10(9)/L. Myelotoxicity and responses in these patients were compared to those of eight patients who received the same therapy without GM-CSF. Patients received a median of three courses (range, 1-8). All 20 patients developed grade 4 neutropenia and grade 3 or 4 thrombocytopenia. The median duration of neutropenia was significantly shorter in patients who received GM-CSF (16.75 vs. 10 days, P = 0.005). However, the two groups did not differ in the proportion of courses associated with hospitalization for febrile neutropenia, the duration of hospitalization, or the median duration of thrombocytopenia. There were two complete, four partial, and three objective responses in the 12 patients treated with ICE plus GM-CSF, and two partial and three objective responses in the 8 patients treated with ICE only. GM-CSF did not reduce the occurrence of febrile neutropenia or the duration of thrombocytopenia associated with ICE chemotherapy. Studies of other hematopoietic growth factors in conjunction with this promising combination are merited.

Enzymatic assay for measurement of zidovudine triphosphate in peripheral blood mononuclear cells

In this report, we describe a new method to measure intracellular zidovudine triphosphate (ZDV-TP) levels in peripheral blood mononuclear cells (PBMCs) from patients treated with ZDV by utilizing inhibition of human immunodeficiency virus type 1 reverse transcriptase activity by ZDV-TP. Intracellular levels of ZDV-TP were determined with our enzymatic assay in PBMCs isolated from the blood of healthy individuals incubated with different concentrations of labeled ZDV and were validated by high-performance liquid chromatography separation and liquid scintillation counting of the radioactive ZDV-TP. These methods gave virtually identical results over a range of ZDV-TP concentrations from 150 to 900 fmol. ZDV-TP recoveries were over 90%, and the limit of quantitation of ZDV-TP by this method was 20 to 50 fmol. To demonstrate the utility of the method, plasma ZDV and intracellular ZDV-TP concentrations were measured at serial time points over 6 h in 12 human immunodeficiency virus-infected volunteers following a single 100- or 500-mg oral dose of ZDV. Systemic oral clearance rates were similar to those in previous studies with adults but were highly variable (range, 0.86 to 2.75 liters/h/kg of body weight). The area under the plasma concentration versus time curve increased significantly (P < 0.0005) with the dose from a median value of 1.2 mg.h/liter at the lower dose to 4.2 mg.h/liter at the higher dose. Median intracellular ZDV-TP levels ranged from 5 to 57 and 42 to 92 fmol/10(6) cells in volunteers administered 100 and 500 mg of ZDV, respectively. Intracellular ZDV-TP levels rose to a plateau value by 2 h and remained consistent to 6 h. Although the higher dose and higher areas under the curve yielded consistently higher intracellular ZDV-TP levels, systemic pharmacokinetics explains only a modest proportion of the variability in cellular pharmacokinetic. The ZDV-TP bioassay should prove useful in further studies of ZDV metabolism in patient-derived PBMCs at the doses of ZDV currently administered.

Phase I study of escalating targeted doses of carboplatin combined with ifosfamide and etoposide in children with relapsed solid tumors

PURPOSE

The tolerance of escalating targeted doses of carboplatin combined with ifosfamide (IFOS)/etoposide (VP-16) (ICE) was assessed in children with recurrent solid tumors.

PATIENTS AND METHODS

To reduce interpatient variability in carboplatin systemic exposure, 45 children were treated with doses individualized to a target area under the serum concentration versus time curve (AUC) based on renal function, using technetium 99-diethyl-enetriamine pentaacetic acid (99mTc-DTPA) clearance to estimate glomerular filtration rate (GFR). Cohorts of at least three patients received carboplatin at an initial target AUC of 2 mg/mL x min, with escalations of 1 mg/mL x min in subsequent cohorts. Courses consisted of carboplatin on day 1 followed by IFOS 2 g/m2 plus VP-16 100 mg/m2 on days 2 and 3. Patients received at least two courses, with a maximum of eight courses possible in the absence of progressive disease. When only moderate toxicity occurred after escalation to 5 mg/mL x min, a third dose of IFOS plus VP-16 was added. After three patients were treated at this level, carboplatin escalation proceeded.

RESULTS

Neutropenia and thrombocytopenia were the dominant toxicities in the 43 assessable patients. At the target AUC of 8 mg/mL x min, 13 of 20 cycles were associated with febrile neutropenia. For phase II trials, we recommend a carboplatin target AUC of 6 mg/mL x min with three doses of IFOS and VP-16 for patients with prior craniospinal irradiation or high-dose cisplatin (CDDP)/VP-16, or 7 mg/mL x min for patients without such histories. There were two complete responses (CRs), 13 partial responses (PRs), and 17 objective responses (ORs).

CONCLUSION

The ICE regimen shows promising activity in pediatric solid tumors. The clear relationship between hematologic toxicity and carboplatin systemic exposure supports the use of targeted dosing in further trials of ICE chemotherapy.

Applying cognitive-behavioral psychotherapy to the chronically ill elderly: treatment issues and case illustration

A large percentage of older adults must endure at least one chronic medical illness. Clinically significant depression and anxiety are common among these patients. Specific psychotherapy approaches as well as adaptations required to address the unique issues of this population have not been delineated in the literature. We outline a cognitive-behavioral therapy approach and discuss five treatment issues we have found to be important for this population. These issues include: (1) resolving practical barriers to participation; (2) accepting depression as a separate and reversible problem; (3) limiting excess disability; (4) counteracting the loss of important social roles and autonomy; and (5) challenging the perception of being a "burden." A case study of a chronic obstructive pulmonary disease (COPD) patient with depression is presented and recommendations for future research are suggested.

Contact formation and transfer of mannose BSA gold from macrophages to cocultured fibroblasts

When macrophages were cocultured with fibroblasts many of the cells formed firm contacts. In some of these contacts both cell types were closely apposed and in others they were more clearly separated with numerous pseudopodia extending from macrophages toward the fibroblasts. Many small vesicles similar in structure to caveoli were observed immediately beneath the plasma membrane of some fibroblasts in regions immediately adjacent to areas of contact with macrophages. The membrane integrity of both cell types was always maintained and no connecting cytoplasmic strands were observed between contacting cells. Junctions were freely permeable to ruthenium red and less permeable to the larger cationized ferritin. Gold conjugated to mannose BSA was taken up readily by macrophages but not by fibroblasts. When fibroblasts were cocultured with macrophages that had been labeled with endocytosed gold, increasing amounts were transferred to them. Gold was observed within gaps formed between cocultured cells and within recipient fibroblasts in vesicles anatomically similar to lysosomes. These points of contact thus appear to provide a series of specialized protected clefts into which directed exocytosis of ligands from donor cells can take place and from which endocytosis into recipient cells is facilitated.

A phase II study of combined methotrexate and teniposide infusions prior to reinduction therapy in relapsed childhood acute lymphoblastic leukemia: a Pediatric Oncology Group study

Teniposide (VM-26) can increase intracellular methotrexate (MTX) and its polyglutamate derivatives in vitro and thus has the potential to improve the therapeutic index of regimens containing MTX. In this phase II study, children and adolescents with acute lymphoblastic leukemia (ALL) in first or second marrow relapse were randomly assigned to receive either simultaneous (n = 11) or sequential (n = 12) continuous infusions of MTX and VM-26 prior to reinduction. Infusions of VM-26 were begun 12 hours after completion of MTX infusion in the sequential group. Dosages were individually adjusted to maintain plasma concentration levels of 10 microns for MTX and 15 microns for VM-26; total infusion times were 24 and 72 hours, respectively. Significant toxicity in the first six patients who received the scheduled 72-hour VM-26 infusion (including one drug-related death) prompted a 50% reduction in infusion duration. The reduced dose was associated with similar but more manageable toxicity. Examination of bone marrow aspirates 10 days after therapy was begun showed one complete and two partial marrow remissions; a fourth patient who had an aplastic marrow on day 10 received no further chemotherapy and had a complete remission (CR) documented on day 31. There was no obvious clinical advantage associated with either infusion schedule, although small sample sizes preclude definitive conclusions. The 17% response rate to the MTX/VM-26 therapeutic window in patients with refractory disease suggests the need for further investigation to evaluate alternative schedules and concomitant therapy for this drug combination.

Progress in arrhythmia therapy

Recent developments in classification and treatment of cardiac arrhythmias are reviewed. The advent of portable continuous ambulatory monitoring of electrocardiograms and of invasive catheterization techniques for electrophysiologically testing the heart has facilitated study of mechanisms and treatment of cardiac arrhythmias. A number of antiarrhythmic drugs are also in the final phases of clinical testing; some of these agents have unique properties that will affect therapeutic approaches. These recent studies and new techniques have led to a reassessment of the classification schemes for both arrhythmias and antiarrhythmic agents. The clinical importance of arrhythmias is also now better understood. Occasional supraventricular tachycardias in otherwise apparently healthy people are not associated with increased mortality. Sustained ventricular tachyarrhythmias, especially in patients with coronary-artery disease, are life-threatening and should be treated immediately and aggressively. Beta-adrenergic antagonists have proven valuable in the prevention of sudden death in patients who have had a myocardial infarction. Clinical trials documenting real advances in reducing mortality caused by electrical instability of the heart have been conducted in patients with recent myocardial infarction but are not yet available for most other patient types.