bluuebunny/crossref_metadata_2025 huggingface dataset:
Medium range real atomic structure of face-centred icosahedral Ho9Mg26Zn65
Authors: Brühne Stefan , Sterzel Roland , Uhrig Eckhard , Gross Christoph , Assmus Wolf
Published: May 2004

A complementary approach to solve quasi crystalline atomic structures in 3-dimensional (3D) real space is presented: The atomic pair distribution function (PDF) of face centred icosahedral Ho9Mg26Zn65 [a(6D) = 2 × 5.18(3) Å] has been obtained from in-house powder X-ray diffraction data (MoKα

1). For the first time, full profile PDF refinements of a quasicrystal were performed: Starting with rational approximant models, derived from 1/1- and 2/1-Al—Mg—Zn, its local and medium range structure was refined (r < 27 Å; R = 12.9%) using the PDF data. 85% of all atoms show Frank-Kasper (FK) type coordinations. The basic structural unit is the 3-shell, 104-atom Bergman cluster (d ≈ 15 Å) comprising a void at its center. The clusters are interconnected sharing common edges and hexagonal faces of the 3rd shells. The remaining space is filled by some glue atoms (9% of all atoms), yielding an almost tetrahedrally close packed structure. All Ho atoms are surrounded by 16 neighbours (FK-polyhedron “P”). Most of them (89%) are situated in the 2nd shell and form a Ho8 cube (edge length 5.4 Å); they are completed by 12 Mg atoms to a pentagon dodecahedron. Cubes in neighbouring clusters are tilted with respect to each other; their superposition generates diffraction symmetry 2/m3̅5̅. The remaining Ho atoms act as glue atoms. As a result and as can be expected for real matter, local atomic coordinations in quasicrystals are similar when compared to common crystalline intermetallic compounds. From our results, the long range quasiperiodic structure of icosahedral Mg—Zn—RE (RE = Y and some rare earths) is anticipated to be a canonical cell tiling (CCT, after Henely) decorated with Bergman clusters.
Revised Tl(I)–O bond valence parameters and the structures of thallous dichromate and thallous uranyl phosphate hydrate
Authors: Locock Andrew J. , Burns Peter C.
Published: May 2004

Thallium(I) has a 6s
2 non-bonding pair of valence-shell electrons, and shows a wide range of coordination environments and mean bond distances to oxygen. Conventional bond valence parameters with B = 0.37 Å are not suitable for modelling the soft acid – hard base Tl(I)—O interactions. Revised bond valence parameters have been derived for these bonds using structural data taken from the Inorganic Crystal Structure Database and the Cambridge Structural Database for 130 Tl(I)—On polyhedra. Both bond valence parameters, R
0 and B, were refined by minimizing the sum of the squared differences between the formal oxidation state and the experimental bond valence sums of the polyhedra. The recommended values for Tl(I)—O bonds are R
0 = 1.927 Å, B = 0.50 Å, and for the assembled set of Tl—O poly hedra yield an average sum of 0.99 νu with a standard deviation of 0.12 νu. The effects of the revised Tl—O bond valence parameters upon structures containing different types of polyhedra of higher bond valence are examined with respect to the crystal structures of thallous di chromate and thallous uranyl phosphate hydrate. Crystallographic data – Tl2Cr2O7: triclinic, P1̅, a = 7.3150(15) Å, b = 7.4006(15) Å, c = 7.6673(16) Å, α = 109.941(4)°, β = 90.458(4)°, γ = 108.067(4)°, R1 = 5.9%; Tl2(UO2)[(UO2)(PO4)]4(H2O)2: monoclinic, Cm, a = 12.9798(9) Å, b = 15.1639(11) Å, c = 9.3384(6) Å, β = 132.310(1)°, R1 = 3.6%.
Crystal structure determination of Ga3(H3O)H8(PO4)6 · 6 H2O from X-ray powder diffraction data
Authors: Ivashkevich Ludmila S. , Lyakhov Alexander S. , Selevich Anatoly F. , Lesnikovich Anatoly I.
Published: May 2004

The crystal structure of the gallium hydrogen phosphate hydrate, Ga3(H3O)H8(PO4)6 · 6 H2O, has been determined from X-ray powder diffraction data. The structure is trigonal, space group P31c (No. 159), with unit cell dimensions a = 9.0227(1) Å, c = 16.6389(3) Å, V = 1173.08(3) Å3, Z = 2, and D
x = 2.59 g/cm3. The structure was solved by direct methods using EXPO program and refined by FULLPROF package to R
Bragg value of 8.6%. Positions of hydrogen atoms were not defined. There are three unique gallium atoms in the crystal structure, having octahedral oxygen coordination. GaO6 octahedra are linked together via the corners of PO4 tetrahedra to form a three-dimensional network with channels running along the c axis. There are two types of water molecules in the crystal, which essentially differ in their atomic environment. Oxonium cations, lying on crystallographic threefold axis, are surrounded by oxygen atoms of the phosphate groups and water molecules.
Local mean chromium–oxygen distances in Cr3+-centered octahedra of natural grossular-uvarovite garnet solid solutions from electronic absorption spectra
Authors: Langer Klaus , Platonov Alexej N. , Matsyuk Stanislav S.
Published: May 2004

The crystal field parameter 10Dq[cm⁻¹]of octahedral chromium obtained as the energy of the4A2g→4T2gband of Cr3+in the electronic absorption spectra, EAS, of a series of 13 natural grossular-uvarovite garnets with compositions close to the binary join Ca3(Al1–xCrx)2Si3O12, depend on the chromium fraction xCrof the solid solutions as

10Dq[cm⁻¹]= (–515.51 ·xCr) + 16579 (r= 0.984)

The 10Dq[cm⁻¹]-values were evaluated in terms of local mean octahedral distances,R̅(Cr–O), [Å]localwith the result that

R̅(Cr–O)local= 0.01262 ·xCr+ 1.9812 (r= 0.982) (a)

Equation (a) is in very good agreement with mean 〈Al/Cr—O〉; distances of “individual” octahedraR̅icalculated for the case XCr(individual)= 1.00 from the distance relations obtained in X-ray structure refinements of low symmetry chromian garnets (Wildner and Andrut, 2001). The proves again, that the EAS-method to derive local 3dN-ion–oxygen distances is reliable.

R̅(Cr–O)local=ƒ(xCr) and the correspondingR̅i-function deviate strongly from the Vegard line of the crystal averaged functionR̅(Cr–O)average=ƒ(xCr), the “virtual crystal model”. This indicates significant structural relaxation around Cr3+[6]in the garnet solid solutions studied. The relaxation coefficient calculated from the data,∊limxCr→0= 0.82, is closer to∊= 1.0 for full relaxation,i.e.the “hard sphere model”, than to∊= 0.0 for absent relaxation in the “virtual crystal” model. This is proposedly related to the uptake of strain around octahedral chromium, in the large (CaO8) polyhedra interconnected with the octahedra of the grossular-uvarovite garnets.
Structural variation and crystal chemistry of LiMe3+Si2O6 clinopyroxenes Me3+ = Al, Ga, Cr, V, Fe, Sc and In
Authors: Redhammer Günther J. , Roth Georg
Published: May 2004

A total of 32 synthetic end-member and solid-solution compounds of the LiM3+Si2O6 (Li = M2 site, M3+ = M1 site = Al, Ga, V, Fe, Sc and In) clinopyroxene series have been investigated by single-crystal X-ray diffraction. Except LiCrSi2O6, all compounds show C2/c symmetry at 295 K. LiCrSi2O6 has space group P21/c but transforms to the high temperature C2/c structure at 335 K. The variations of structural parameters in the LiMe3+Si2O6 clinopyroxenes are dominated by the Me3+ site. The average M1—O bond length is linearly correlated with the ionic radius of the M1 cation. Octahedra reflect the increasing size of the M1 cations by steadily increasing bond and edge lengths, the variations however are not uniform. With increasing size of the M1 cation, octahedra deviate from ideal octahedral geometry. Octahedral edges, shared with other structural units, are distinctly hampered in expansion with increasing size of the M1 cation. The increasing size of the M1 octahedral chain is compensated by changing the kinking of the tetrahedral chain and by alterations of bond and edge lengths as well as the bond angles within the tetrahedron. Three different mechanisms of adapting of the structural building units with increasing M3+ cationic radius can be identified: (i) expansion of the tetrahedral chain by stretching (ii) transition form “O” to “S” chain conformation after full expansion and (iii) finally a limit of expansion in a direction. We stress that cations larger than In3+ cannot be substituted at the M1 site because of too large geometrical differences between octahedral and tetrahedral chains.
Propylene Glycol‐Associated Renal Toxicity from Lorazepam Infusion
Authors: Yaucher Ndidi E. , Fish Jeffrey T. , Smith Heidi W. , Wells Jeffrey A.
Published: May 2004

Objectives. Using data from patients who developed elevations in serum creatinine concentrations while receiving continuous‐infusion lorazepam, we sought to determine the correlations between the magnitude of serum creatinine concentration rise and each of the following variables: serum propylene glycol level, cumulative lorazepam dose, and duration of lorazepam administration. An additional objective was to identify clinical markers for propylene glycol toxicity.

Design. Retrospective chart review.

Setting. Medical‐surgical intensive care unit and burn unit at a university hospital.

Patients. Eight patients who developed elevations in serum creatinine concentrations while receiving continuous‐infusion lorazepam (range 2–28 mg/hr).

Measurements and Main Results. The mean cumulative dose of lorazepam was 4305 mg (range 1200–10,920 mg), and the mean propylene glycol level determined at the time of peak serum creatinine concentration was 1103 μg/ml (range 186–3450 μg/ml). Serum creatinine concentrations increased in all eight patients during lorazepam infusion and decreased in seven within 3 days after stopping infusion. A weak‐to‐moderate correlation existed between the magnitude of the rise in serum creatinine concentration and propylene glycol level (r=0.53). A weak‐to‐moderate correlation also was identified between cumulative lorazepam dose and magnitude of serum creatinine concentration rise (r=0.43), and a strong‐to‐moderate correlation was found between duration of lorazepam infusion and magnitude of serum creatinine concentration rise (r=0.60). Propylene glycol levels were strongly correlated with both serum osmolality and osmol gap.

Conclusion. The patients' increased serum creatinine concentrations are likely to have resulted from exposure to propylene glycol as a result of lorazepam infusion. Serum osmolality and osmol gap may be useful markers for propylene glycol toxicity.
Outcomes of Dual–Protease Inhibitor Salvage Therapy in Human Immunodeficiency Virus–Infected Patients Referred to a Telephone Consultation Service
Authors: Lim Michael L. , Dong Betty J. , Hart Stacey L.
Published: May 2004

Objective. To determine the clinical outcomes of dual‐protease inhibitor salvage therapy in heavily experienced patients after their providers consulted the National HIV Telephone Consultation Service (Warmline, 800–933–3413).

Design. Observational survey study.

Setting. Consultation service for United States health care providers.

Patients. Thirty‐one human immunodeficiency virus (HIV)‐infected patients who had received previous treatment with at least two protease inhibitor‐or nonnucleoside reverse transcriptase inhibitor‐based regimens and had a viral load of at least 1000 copies/ml.

Intervention. Patients whose providers consulted Warmline regarding antiretroviral salvage regimens were identified through a review of telephone calls from January‐July 2001. Virologic and immunologic outcomes were determined for patients who had received a regimen containing either ritonavir and indinavir or ritonavir and amprenavir.

Measurements and Main Results. Primary outcomes were percentages of patients with a viral load less than 500 copies/ml at 3 and 6 months and changes in log10 viral load and CD4+ cell count at 3 and 6 months compared with baseline values. By using intent‐to‐treat analysis, a viral load less than 500 copies/ml was achieved in 35% of the 31 patients at 3 months and in 32% of them at 6 months. By using as‐treated analysis, this outcome was achieved in 48% of 23 patients who continued therapy at 3 months and in 59% of 17 patients who continued therapy at 6 months. At 3 months (23 patients) and 6 months (17 patients), respectively, changes in viral load were −1.7 log10 copies/ml (p<0.001) and −1.4 log10copies/ml (p<0.001), and changes in CD4+ cell count were +99 cells/mm3 (p<0.001) and +95 mm3 (p=0.012), compared with baseline.

Conclusion. Significant improvements in virologic and immunologic markers occurred in patients heavily experienced with antiretroviral therapy after starting dual‐protease inhibitor treatment regimens. Salvage therapy guided by Warmline consultation appears to be beneficial for this patient population with limited treatment options.
Essential Tremor: Diagnosis and Treatment
Authors: Chen Jack J. , Swope David M.
Published: May 2004

Essential tremor is a common movement disorder in adults that interferes with the performance of functional and social activities. Differentiation of essential tremor from other tremor syndromes is important in order to provide appropriate patient education and therapy. The mainstays of pharmaco‐therapy are propranolol and primidone; however, in selected patients, agents such as alcohol, benzodiazepines, botulinum toxin, and gabapentin may provide symptomatic benefits. Advances in surgical interventions, such as stereotactic thalamotomy and thalamic deep brain stimulation, offer patients an alternative treatment modality when pharmacotherapy is inadequate. A treatment algorithm is provided to guide clinicians in the management of patients with essential tremor.
Pancreatitis Associated with Atypical Antipsychotics: From the Food and Drug Administration's MedWatch Surveillance System and Published Reports
Authors: Koller Elizabeth A. , Cross James T. , Doraiswamy P. Murali , Malozowski Saul N.
Published: May 2004

Study Objective. To investigate the relative numbers and clinical characteristics of pancreatitis in patients treated with the atypical antipsychotic agents, clozapine, olanzapine, and risperidone, versus the conventional neuroleptic, haloperidol.

Design. Pharmacovigilance study of pooled, spontaneously reported adverse events.

Setting. Government‐affiliated drug evaluation center.

Patients. One hundred ninety‐two patients who developed pancreatitis during treatment with one or more antipsychotic agents.

Intervention. Patients were identified with the Food and Drug Administration's MedWatch surveillance program and a MEDLINE search.

Measurements and Main Results. Most cases of pancreatitis occurred within 6 months after the start of therapy with one or more antipsychotic agents. Of the reports of pancreatitis occurring in conjunction with these drugs, 40%, 33%, 16%, and 12% were in patients receiving treatment with clozapine, olanzapine, risperidone, and haloperidol, respectively. In 50% of the patients receiving haloperidol, an atypical antipsychotic was listed as a concomitant drug. Valproate was administered concomitantly in 23% of patients. Hyperglycemia and acidosis, although uncommon, developed with all the drugs except haloperidol. Twenty‐two patients died. In contrast to patients who developed pancreatitis while receiving an atypical antipsychotic, those who developed the disease while receiving haloperidol were women and tended to be older.

Conclusion. The number of reports involving the three atypical antipsychotic agents and the relative paucity of reports involving haloperidol, despite its more extensive patient exposure, suggest that atypical antipsychotics may precipitate pancreatitis. However, the risk may not be the same with all agents; pancreatitis was reported most frequently with clozapine, followed by olanzapine, and then risperidone. The temporal relationship of the onset of pancreatitis with the start of drug therapy further supports a cause‐and‐effect relationship.
Impact of a Collaborative Care Model on Depression in a Primary Care Setting: A Randomized Controlled Trial
Authors: Finley Patrick R. , Rens Heidi R. , Pont Joan T. , Gess Susan L. , Louie Clifton , Bull Scott A. , Lee Janelle Y. , Bero Lisa A.
Published: May 2004

To measure the effects of a collaborative care model that emphasized the role of clinical pharmacists in providing drug therapy management and treatment follow‐up to patients with depression, we conducted a randomized controlled trial at a staff model health maintenance organization. We compared the outcomes of subjects treated in this collaborative care model (75 patients, intervention group) with subjects receiving usual care (50 patients, control group). After 6 months, the intervention group demonstrated a significantly higher drug adherence rate than that of the control group (67% vs 48%, odds ratio 2.17, 95% confidence interval 1.04–4.51, p=0.038). Patient satisfaction was significantly greater among members randomly assigned to pharmacists' services than among controls, and provider satisfaction surveys revealed high approval rates as well. Changes in resource utilization were favorable for the intervention group, but differences from the control group did not achieve statistical significance. Clinical improvement was noted in both groups, but the difference was not significant. Clinical pharmacists had a favorable effect on multiple aspects of patient care. Future studies of this model in other health care settings appear warranted.
Vancomycin‐Induced Thrombocytopenia: A Case Proven with Rechallenge
Authors: Marraffa Jeanna , Guharoy Roy , Duggan David , Rose Frederick , Nazeer Syed
Published: May 2004

In a rare case of vancomycin‐induced thrombocytopenia, a 50‐year‐old man with culture‐negative subacute bacterial endocarditis underwent mitral valve replacement surgery and was treated with vancomycin. His platelet count dropped from 346 times 103/mm3 to 13 times 103/mm3 on postoperative day 4, and a differential diagnosis of heparin‐ versus drug‐induced thrombocytopenia was considered. Antiheparin antibodies were detected in the patient's serum on day 5. He showed no signs of bleeding. His platelet count remained below 5 times 103/mm3 despite two platelet transfusions on day 5. A hemorrhagic pericardial effusion with tamponade developed, requiring drainage. A trial with intravenous immunoglobulin led to fever and chills, and the infusion was not completed. Vancomycin was changed to clindamycin on day 9, and methylprednisolone therapy was started on day 11. On day 12, the patient's clinical condition improved, and his platelet count increased from 3 times 103/mm3 to 32 times 103/mm3 with no bleeding. On day 18, his platelet count was 424 times 103/ mm3, and he was scheduled for discharge with vancomycin therapy for a total of 6 weeks. He received a single dose of intravenous vancomycin 1 g at the hospital; his platelet count dropped to 160 times 103/mm3 1 hour after the infusion and to 58 times 103/mm3 12 hours later. Vancomycin was discontinued and clindamycin and prednisone were restarted. On day 20, the patient's platelet count increased to 105 times 103/mm3 and he was discharged with warfarin, prednisone, and clindamycin therapy. We suspect that our patient's thrombocytopenia was due to vancomycin.
Acute Renal Failure Secondary to Angiotensin II Receptor Blockade in a Patient with Bilateral Renal Artery Stenosis
Authors: Wargo Kurt A. , Chong Kenneth , Chan Evelyn C. Y.
Published: May 2004

A 54‐year‐old man with diabetes mellitus, peripheral vascular disease, and hypertension was admitted to the hospital for an acute exacerbation of chronic heart failure. Therapy with intravenous furosemide and oral losartan 100 mg twice/day was begun. Ten days later, the patient's blood urea nitrogen and serum creatinine levels rose and peaked at 110 and 6.0 mg/dl, respectively. His serum potassium level increased to 5.7 mg/dl, urine output dropped to 400 ml over 24 hours, and mental status changes occurred. Magnetic resonance angiography revealed bilateral renal artery stenosis. After losartan was discontinued and hemodialysis was performed for 3 consecutive days, the patient's renal function returned to his baseline level. Reports in the medical literature reinforce the importance of recognizing that angiotensin‐converting enzyme inhibitors should be used with caution in patients with bilateral renal artery stenosis. However, the literature is not as definitive about using of angiotensin II receptor blockers (ARBs) in these patients. Our patient's experience suggests that ARBs should be used with caution in patients with bilateral renal artery stenosis. Clinicians should be aware that renal failure might occur when using ARBs in these patients.
Comparison of Neural Network, Bayesian, and Multiple Stepwise Regression‐Based Limited Sampling Models to Estimate Area Under the Curve
Authors: Ng Chee M.
Published: May 2004

This study compared limited sampling methods (LSM) of estimating area under the plasma concentration versus time curve (AUC) based on a Bayesian regularized neural network, the Bayesian approach, and multiple forward stepwise regression models from selected concentration‐time points. Plasma concentration versus time data sets with a linear two‐compartmental pharmacokinetic model were simulated. A limited sampling method based on the forward stepwise regression model was developed and validated. Plasma concentration‐time points selected by the stepwise regression model were used for neural network and Bayesian evaluation. In addition, 55 plasma concentration‐time profiles from two clinical studies were used to develop and compare the predicted AUClast for the three approaches. From simulated data sets, mean prediction errors for AUClast estimation were 0.00, −5.32, and −6.06 for the neural network, Bayesian approach, and forward stepwise regression LSM, respectively. Mean square errors were 581, 588, and 618, respectively. For clinical data set, model mean prediction errors were 0.00, 3.51, and 3.87, respectively. Model mean square errors were 30.6, 109, and 76, respectively. For both simulated and clinical data sets, the neural network approach to estimate AUClast from selected time points was numerically more precise and significantly less biased than the other two methods.
Assessment of Factors Influencing Blood Pressure Control in a Managed Care Population
Authors: Romain Tanya M. , Patel Rosalie P. , Heaberlin Andrea M. , Zarowitz Barbara J.
Published: May 2004

We attempted to determine the percentage of patients meeting Health Plan Employer Data Information Set (HEDIS) criteria for blood pressure control (≤ 140/90 mm Hg), to identify factors contributing to differences in blood pressure control among those who met HEDIS criteria and those who did not, and to assess compliance with blood pressure management recommendations established by the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC‐VI) for diabetes mellitus and myocardial infarction. In this retrospective analysis, we randomly selected 502 patient records from three primary care clinics in southeast Michigan. All patients were commercial members of one health maintenance organization, 74% of whom met HEDIS criteria for blood pressure control. These patients took fewer blood pressure drugs throughout the year (p=0.023) and had lower antihypertensive drug costs than those who did not achieve HEDIS blood pressure goals (p=0.016). According to JNC‐VI criteria, 46% of diabetic patients were at their blood pressure goal of below 130/85 mm Hg and 71.6% were managed with angiotensin‐converting enzyme inhibitors or angiotensin receptor blockers. Eighty‐five percent of patients were taking β‐blockers after myocardial infarction. The percentage of patients achieving target blood pressure exceeded the national average and was associated with few antihypertensive drugs and low drug cost. Effective and appropriate management of blood pressure in people with diabetes remains a challenge.
Linezolid Clearance During Continuous Venovenous Hemodiafiltration: A Case Report
Authors: Kraft Michael D. , Pasko Deborah A. , DePestel Daryl D. , Ellis Jessica J. , Peloquin Charles A. , Mueller Bruce A.
Published: May 2004

Objective. To determine the linezolid clearance and serum concentrations in a critically ill man receiving continuous venovenous hemodiafiltration (CVVHDF).

Methods. Intravenous linezolid 600 mg every 12 hours was administered to a critically ill, 85‐year‐old man with anuria who was receiving CVVHDF at a dialysate flow rate of 2000 ml/hour and a mean ultrafiltrate production rate of 775 ml/hour. Samples of blood and spent dialysate and ultrafiltrate were obtained at the time of linezolid peaks and troughs, and linezolid concentrations were determined.

Results. The CVVHDF yielded a mean linezolid clearance of 36.5 ml/minute and an elimination half‐life of 7.5 hours. The linezolid saturation coefficient ranged from 0.77–0.81. Administration of intravenous linezolid 600 mg every 12 hours yielded suitable serum trough concentrations.

Conclusion. Administration of intravenous linezolid 600 mg every 12 hours maintained therapeutic serum trough concentrations in this critically ill patient receiving CVVHDF.
Capecitabine‐Induced Pancreatitis
Authors: Jones Kellie L. , Valero Vicente
Published: May 2004

A 47‐year‐old woman with metastatic breast cancer developed acute pancreatitis while receiving capecitabine. She had been receiving capecitabine 2000 mg/m2/day; however, when the dosage was increased to 2500 mg/m2/day (the maximum dosage approved by the Food and Drug Administration) she experienced abdominal pain and cramping. These symptoms were followed by nausea and vomiting, palmar‐plantar erythrodysesthesia (hand‐foot syndrome), and mucositis, resulting in admission to the hospital. Laboratory tests for liver function showed elevated levels of alkaline phosphatase and lactate dehydrogenase. The patient's lipase and amylase levels were also elevated, but an abdominal ultrasound was normal. After bowel rest and intravenous hydration, the patient's liver function tests and lipase and amylase levels returned to normal. Many chemotherapeutic agents have been documented to cause pancreatitis; however, we found no previously described reports of capecitabine‐induced pancreatitis. Clinicians should be aware of this potential adverse effect, particularly in patients with preexisting risk factors for pancreatitis who are prescribed capecitabine.
Estimating the Cost of the Medicare Pharmacist Services Coverage Act of 2001
Authors: Poole Virginia H. , Moran Donald W. , Webb C. Edwin
Published: May 2004

Background. In recent years considerable attention has focused on pharmacists' professional evolution toward patient care‐oriented practice. The Pharmacist Provider Coalition (PPC), established in 2000, seeks recognition and payment for pharmacists' patient care services. Concerted effort by the PPC on this issue resulted in the introduction of the Medicare Pharmacist Services Coverage Act of 2001, which would have amended Title XVIII of the Social Security Act to create new types of covered services under Medicare and recognize pharmacist practitioners as providers. However, the legislation was not passed by the 107th Congress.

Study Objectives. The PPC engaged The Moran Company to measure the potential net cost to the United States government of the Medicare Pharmacist Services Coverage Act of 2001, and to perform this measurement in a manner that is consistent with the cost‐projection methods used by the Congressional Budget Office (CBO).

Design. The model is anchored to the 10‐year projection of revenues and spending within the federal government developed annually by the CBO. It examines the anticipated magnitude and cost of patient care services with respect to chronic disease and pharmaceutical therapy management, in both facility and nonfacility settings.

Results. The methodology yields a final cost estimate of $427 million in 2004, the first year of implementation, and a 10‐year estimate of $13 billion.

Conclusions. Recognition of pharmacists as providers of selected drug therapy management services under Medicare will have a considerable financial impact. It is instructive, however, to view the 10‐year cost estimate of $13 billion for pharmaceutical therapy management in light of the CBO's projected $1.5 trillion estimate, over the same time frame, for drug spending among the Medicare population.
Effects of Amphotericin B and Caspofungin on Histamine Expression
Authors: Cleary John D. , Schwartz Michael , Rogers P. David , de Mestral Jacqueline , Chapman Stanley W.
Published: May 2004

Study Objective. To determine the effects of amphotericin B deoxycholate and caspofungin on the release of histamine from human peripheral blood cells, mononuclear cells, and mast cells.

Design. In vitro cell culture experiments.

Setting. University medical center.

Material. Cultured human mononuclear (THP‐1) and mast (HMC‐1) cells from five healthy volunteers.

Measurements and Main Results. The cultured cells were incubated with increasing concentrations of amphotericin B deoxycholate, diphen‐hydramine, amphotericin B deoxycholate plus diphenhydramine, caspofungin, caspofungin plus diphenhydramine, and the calcium ionophore A23187 for up to 24 hours. Histamine concentrations and histamine N‐methyltransferase activity were determined at various time points throughout exposure. Cell viability was assessed by exclusion of erythrocin B. The A23187 increased histamine concentrations from baseline in peripheral blood and HMC‐1 cells. No change in histamine concentrations was observed in response to amphotericin B deoxycholate, whereas caspofungin induced a significant increase in histamine release in peripheral blood cells and HMC‐1 cells. No change in histamine concentrations was observed in THP‐1 cells in response to any pharmacologic agent tested. Similarly, histamine N‐methyltransferase activity in peripheral blood was not affected by amphotericin B deoxycholate, but was significantly decreased by caspofungin.

Conclusion. Amphotericin B deoxycholate does not affect histamine concentrations or histamine N‐methyltransferase activity in whole blood or HMC‐1 cells, suggesting that the amphotericin B‐induced infusion‐related reaction is not a histamine‐mediated event. Conversely, caspofungin increased histamine concentrations in whole blood and HMC‐1 cells and inhibited histamine N‐methyltransferase activity. These data suggest that infusion‐related reactions associated with caspofungin may be mediated by histamine release secondary to caspofungin.
Effects of Grapefruit Juice on Intestinal P‐glycoprotein: Evaluation Using Digoxin in Humans
Authors: Parker Robert B. , Yates C. Ryan , Soberman Judith E. , Laizure S. Casey
Published: May 2004

Study Objectives. To determine the effects of grapefruit juice on the pharmacokinetics of oral digoxin, a P‐glycoprotein substrate not metabolized by cytochrome P450 3A4, in healthy volunteers, and to assess whether polymorphic multidrug‐resistance‐1 (MDR1) expression contributes to interindividual variability in digoxin disposition.

Design. Prospective, open‐label, unblinded, crossover study.

Setting. University research center.

Subjects. Seven healthy adult volunteers (four men, three women).

Intervention. Each subject received a single oral dose of digoxin 1.0 mg with water or grapefruit juice with at least a 2‐week washout between treatments. During the grapefruit juice phase, juice was administered 3 times/day for 5 days before digoxin administration to maximize any effect on P‐glycoprotein.

Measurements and Main Results. Digoxin pharmacokinetics in the presence and absence of grapefruit juice were compared. The MDR1 exon 26 C3435T genotype was determined by real‐time polymerase chain reaction. Compared with water, grapefruit juice significantly reduced the digoxin absorption rate constant (3.0 ± 2.4 to 1.2 ± 1.0 hr−1, p<0.05) and increased absorption lag time (0.32 ± 0.12 to 0.53 ± 0.34 hr, p<0.05). Grapefruit juice did not affect digoxin maximum concentration (Cmax), area under the curve (AUC), elimination half‐life, or renal clearance. The effect of grapefruit juice on digoxin Cmax (‐45% to +41%) and AUC0–4 (‐29% to +25%) varied substantially among subjects and was inversely correlated with the values during the water phase. Trends toward higher digoxin Cmax, AUC, and absorption rate constant during the water phase were found in CC homozygotes compared with subjects carrying a T allele.

Conclusion. Inhibition of intestinal P‐glycoprotein does not appear to play an important role in drug interactions involving grapefruit juice. Interindividual variability in response to grapefruit juice may be related to the balance of intestinal drug uptake and efflux transport.
Acute Decompensated Heart Failure: A Contemporary Approach to Pharmacotherapeutic Management
Authors: McBride Brian F. , White C. Michael
Published: May 2004

Hospital admissions for acute decompensated heart failure (ADHF) have increased precipitously during the past few decades and are projected to continue to increase in the future. To optimize patient outcomes and reduce the costs associated with this disorder, evidenced‐based pharmacotherapy is essential. Continuous infusions of loop diuretic therapy rather than bolus dosing may enhance efficacy and reduce the extent of diuretic resistance. Nesiritide is a pharmacologically novel preload and afterload reducer but based on clinical trial evidence should be reserved for those unable to take or with resistance to intravenous nitrate therapy. Catecholamine‐ and phosphodiesterase‐based inotropic therapies are efficacious, but the increased risk of arrhythmogenesis and the potential for negative survival effects limit their use. The experimental agent levosimendan is a positive inotropic agent but does not increase myocyte calcium concentrations as do catecholamines or phosphodiesterase inhibitors. Clinical trial evidence demonstrates a positive survival benefit for levosimendan versus dobutamine.
Generalized Gradient Approximation Functionals
Authors: Handy Nicholas C
Published: May 2004

The principle purpose is to explain why density functional theory within the generalized gradient approximation is such a valuable computational tool. The topic is introduced in a straightforward manner, through the Wilson understanding and the contribution of Kohn and Sham. We concentrate on the exchange‐correlation functionals. The importance of the uniform electron gas is stressed, in particular that its exchange hole is always localized.

Exchange functionals are best determined to give Kohn–Sham energies, which are close to the Hartree–Fock energies of atoms, because it is argued that all correlation within atoms is short range or dynamic. The famous Becke functional was determined this way. Likewise, correlation functionals may be determined from the correlation properties of atoms, such as that known as Lee, Yang, and Parr (LYP). Alternatively, exchange‐correlation functionals may be determined mathematically from the properties of the perturbed electron gas, following Perdew. All these functionals are parameter‐free, as far as molecules are concerned. This is a great advantage.

It is argued that such exchange functionals introduce left–right correlation within molecules. This is explained through a study of the exchange hole of

$\hbox{H}_{2}$

at infinite separation, looking at both the Hartree–Fock wave function and the exact wave function, for which the hole is delocalized/localized respectively. This approach to density functional theory introduces a clear separation of left–right and dynamic correlation, which is impossible in quantum chemistry. The remarkable success of the theory is demonstrated with a table of computed binding energies of small molecules.

It is explained why the HOMO eigenvalues of these Kohn–Sham calculations must be close to electronegativities; they will not be approximations to the negative of the ionization potential. There is no error; it all follows from the quantum‐mechanical integer discontinuity. The asymptotic value of the exchange‐correlation potential is nonzero.

Other generalized gradient approximation functionals are more briefly discussed. Hybrid functionals and meta functionals are outside the scope of this review, principally because they do not give local exchange‐correlation potentials.
MSINDO
Authors: Bredow Thomas , Jug Karl
Published: May 2004

The recently developed semiempirical molecular orbital method MSINDO is described. The parametrization for first‐, second‐, and third‐row elements is presented. There is an option for the inclusion of higher multipole terms. Two new features of the program are the cyclic cluster model and molecular dynamics simulations. Relevant applications include structures and growth of silsesquioxanes, simulation of solids and surfaces of ionic compounds, and adsorption and reactions on such surfaces.
Diet, foraging, and use of space in wild golden‐headed lion tamarins
Authors: Raboy Becky E. , Dietz James M.
Published: May 2004

Lion tamarins (Callitrichidae: Leontopithecus) are small frugi‐faunivores that defend large home ranges. We describe results from the first long‐term investigation of wild golden‐headed lion tamarins (L. chrysomelas; GHLTs). We present data about activity budgets, daily activity cycles, diet, daily path length, home range size, home range overlap, and territorial encounters for three groups of GHLTs that were studied for 1.5–2.5 years in Una Biological Reserve, Bahia State, Brazil, an area characterized by aseasonal rainfall. We compare our results to those from other studies of lion tamarins to identify factors that may influence foraging and ranging patterns in this genus. Ripe fruit, nectar, insects, and small vertebrates were the primary components of the GHLT diet, and gums were rarely eaten. Fruit comprised the majority of plant feeding bouts, and the GHLTs ate at least 79 different species of plants from 32 families. The most common foraging sites for animal prey were epiphytic bromeliads. The GHLTs defended large home ranges averaging 123 ha, but showed strong affinities for core areas, spending 50% of their time in approximately 11% of their home range. Encounters with neighboring groups averaged two encounters every 9 days, and they were always aggressive. Data about time budgets and daily activity cycles reveal that the GHLTs spent most of their time foraging for resources or traveling between foraging sites distributed throughout their home ranges. The GHLTs spent much less time consuming exudates compared to lion tamarins in more seasonal environments. Additionally, the GHLTs had much larger home ranges than golden lion tamarins (L. rosalia), and did not engage in territorial encounters as frequently as L. rosalia. GHLT ranging patterns appear to be strongly influenced by resource acquisition and, to a lesser extent, by resource defense. Am. J. Primatol. 63:1‐15, 2004. © 2004 Wiley‐Liss, Inc.
Ovarian cycle phase and same‐sex mating behavior in Japanese macaque females
Authors: O'Neill Ann C. , Fedigan Linda M. , Ziegler Toni E.
Published: May 2004

The relationship of the ovarian cycle phase to same‐sex mounting activity in adult female Japanese macaques (Macaca fuscata) was studied during the 1997/1998 mating season. Fecal samples were collected from eight female subjects two to three times per week and analyzed by enzyme immunoassay for fecal hormone levels. Hormone profiles of estrone (E1) and pregnanediol (PdG) were used to separate ovarian cycles into three phases: follicular, periovulatory, and luteal. Patterns of same‐sex and heterosexual mounting behavior in the females were analyzed for phase variation during conceptive cycles. Same‐sex mounting among female Japanese macaques occurred most frequently during the follicular and periovulatory phases of the cycle, and not at all during the luteal phase, paralleling the pattern found in heterosexual mounting behavior. These findings suggest a link between hormonal fluctuations and patterns of sexual mounting, regardless of whether the partner is of the same or opposite sex. Am. J. Primatol. 63:25–31, 2004. © 2004 Wiley‐Liss, Inc.
Mechanism of Reppe's Nickel‐Catalyzed Ethyne Tetramerization to Cyclooctatetraene: A DFT Study
Authors: Straub Bernd F. , Gollub Caroline
Published: May 2004

In this B3 LYP model study, homoleptic nickel(0) ethyne complexes have been predicted as the catalyst resting state for the title reaction. Ethyne ligand coupling of Ni(C2H2)3 yields monoethyne nickelacyclopentadiene in the rate‐determining step. Ethyne coordination is followed by insertion of an ethyne ligand into the NiC σ bond. A highly strained monoethyne trans‐nickelacycloheptatriene is formed. This trans intermediate is unable to reductively eliminate benzene without prior isomerization to a cis‐structure. Instead, it rapidly collapses to a nickelacyclononatetraene. Ethyne coordination induces reductive elimination to the cyclooctatetraene complex Ni(η2‐C2H2)(η2‐C8H8), followed by facile ligand exchange. Other ethyne coupling pathways have been computed to be less favored. The cyclooctatetraene ligand binds significantly weaker to nickel(0) than ethyne, both for mononuclear, and for dinuclear species. For this reason, CC bond formation steps at Ni2(μ‐cot) fragments have been predicted to feature prohibitively high overall reaction barriers.
Human immunodeficiency virus–related primary central nervous system lymphoma
Authors: Newell Mark E. , Hoy Jennifer F. , Cooper Stephen G. , DeGraaff Bernadette , Grulich Andrew E. , Bryant Melissa , Millar Jeremy L. , Brew Bruce J. , Quinn David I.
Published: May 2004

BACKGROUND

The current study evaluated factors influencing survival in patients diagnosed with human immunodeficiency virus (HIV)‐related primary central nervous system lymphoma (PCNSL), with a focus on the effects of therapeutic radiotherapy (RT) and highly active antiretroviral therapy (HAART).

METHODS

A retrospective chart review of patients with a diagnosis of HIV‐related PCNSL at one of five university hospitals between 1987 and 1998 was performed. Clinical details including antiretroviral agent use, brain imaging scan results, RT use, and survival outcomes were recorded.

RESULTS

One hundred eleven patients with HIV‐related PCNSL were identified. The annual incidence decreased significantly between 1992 and 1995 and between 1996 and 1998 (P= 0.04). The median survival period was 50 days (mean, 109 days; range, 4–991 days), with improved survival for patients diagnosed after 1993. Patients treated with two or more antiretroviral agents had improved survival (P= 0.01), as did patients who received RT (P< 0.0001). For patients who received RT, completion of the prescribed course and treatment to ≥ 30 Gray (Gy) independently predicted a more favorable outcome. RT used in conjunction with antiretroviral therapy involving two or more agents had an additive positive effect on survival. For patients who did not receive RT, poor performance status and encephalopathy predicted a shorter survival duration.

CONCLUSIONS

The results of the current study suggest that HAART and treatment with RT to ≥ 30 Gy improve survival for patients with HIV‐related PCNSL. This combination of therapies may provide a standard of care as the basis for further trials of chemotherapy, novel adjunctive treatment, and quality of life assessment. Cancer 2004. © 2004 American Cancer Society.
Dynamic stability of thin‐walled column under periodic excitation
Authors: Wang Quanfeng , Luo Yi
Published: May 2004

The dynamic stability of variable stiffness thin‐walled column subjected to periodically alternating axial force is analysed in this paper. Here, the variable stiffness means that it changes with periodically alternating axial force as for non‐linear geometry stiffness matrix of thin‐walled column. Damping is not considered at present. A system of second‐order differential equations with period coefficients of the Mathieu type describes the dynamic stability of thin‐walled columns without damping. To solve the problem the finite element method is applied which can greatly reduce the process of simplification. By using MATLAB package, a computer program is developed to calculate the region of dynamic instability without damping corresponding to bending vibration, torsion and warping coupling vibration. The results prove to be more efficient and credible, compared with other calculation methods. Copyright © 2004 John Wiley & Sons, Ltd.
Hydrodynamic limits with shock waves of the Boltzmann equation
Authors: Yu Shi‐Hsien
Published: May 2004

We show that piecewise smooth solutions with shocks of the Euler equations in gas dynamics can be obtained as the zero Knudsen number limit of solutions of the Boltzmann equation for hard sphere collision model. The construction of the Boltzmann solutions is done in two steps. First we introduce a generalized Hilbert expansion with shock layer correction to construct approximations to the solutions of the Boltzmann equations with small Knudsen numbers. We then apply the recently developed macro‐micro decomposition and energy method for Boltzmann shock layers to construct the exact Boltzmann solutions through the stability analysis. © 2004 Wiley Periodicals, Inc.
Effects of Ion‐Carrier Substituents on the Potentiometric‐Response Characteristics in Anion‐Selective Membrane Electrodes Based on Iron Porphyrins
Authors: Shahrokhian Saeed , Seifi Hassan , Bagherzadeh Mojtaba , Mousavi S. Reza
Published: May 2004

The potentiometric response characteristics with respect to salicylate anion of several membrane electrodes based on iron(III) tetraphenylporphyrin chloride (FeTPPCl) and derivatives with electrophilic and nucleophilic substituents, incorporated into plasticized polyvinylchloride (PVC) membranes were investigated. Complexes tetraphenyl porphyrin iron(III) chloride (FeTPPCl; A), tetrakis (4‐methoxyphenyl) porphyrin iron(III) chloride (Fe(TOCH3PP)Cl; B), tetrakis (2,6‐dichlorophenyl) porphyrin iron(III) chloride (Fe(TDClPP)Cl; C), tetrakis (4‐nitrophenyl) porphyrin iron(III) chloride (Fe(TNO2PP)Cl; D), and tetrakis (pentafluorophenyl) porphyrin iron(III) chloride (Fe(TPFPP)Cl; E) were used as anion carriers in the membrane electrodes. The sensitivity, working range, detection limit, response mechanism, and selectivity of the membrane sensor toward interference shows a considerable dependence on the type of carrier substituent and the pH value of the sample solution. Potentiometric investigations in solutions of various pH show that the carrier complex containing fluoro substituents (E), which have very strong electron‐accepting properties and a high ability to form hydrogen bonds, is capable of serving as a positively charged ionophore. Some other ionophores are capable of serving as both charged and neutral carriers under different conditions. The electrodes prepared in this work show super‐Nernstian slopes with respect to salicylate concentration, which tend to a Nernstian response (slope near to −59 mV decade−1) upon an increase of the pH of the test solution. The results of UV/Vis absorption spectroscopy are used for interpretation of the formation of an oxene complex between salicylate and iron porphyrins.