Biochemical effects of copper nanomaterials in human hepatocellular carcinoma (HepG2) cells

In dose-response and structure-activity studies, human hepatic HepG2 cells were exposed for 3 days to nano Cu, nano CuO or CuCl2 (ions) at doses between 0.1 and 30 ug/ml (approximately the no observable adverse effect level to a high degree of cytotoxicity). Various biochemical parameters were then evaluated to study cytotoxicity, cell growth, hepatic function, and oxidative stress. With nano Cu and nano CuO, few indications of cytotoxicity were observed between 0.1 and 3 ug/ml. In respect to dose, lactate dehydrogenase and aspartate transaminase were the most sensitive cytotoxicity parameters. The next most responsive parameters were alanine aminotransferase, glutathione reductase, glucose 6-phosphate dehydrogenase, and protein concentration. The medium responsive parameters were superoxide dismutase, gamma glutamyltranspeptidase, total bilirubin, and microalbumin. The parameters glutathione peroxidase, glutathione reductase, and protein were all altered by nano Cu and nano CuO but not by CuCl2 exposures. Our chief observations were (1) significant decreases in glucose 6-phosphate dehydrogenase and glutathione reductase was observed at doses below the doses that show high cytotoxicity, (2) even high cytotoxicity did not induce large changes in some study parameters (e.g., alkaline phosphatase, catalase, microalbumin, total bilirubin, thioredoxin reductase, and triglycerides), (3) even though many significant biochemical effects happen only at doses showing varying degrees of cytotoxicity, it was not clear that cytotoxicity alone caused all of the observed significant biochemical effects, and (4) the decreased glucose 6-phosphate dehydrogenase and glutathione reductase support the view that oxidative stress is a main toxicity pathway of CuCl2 and Cu-containing nanomaterials.

Outcomes for circulatory death and brainstem death pancreas transplantation with or without use of normothermic regional perfusion

Simultaneous pancreas and kidney transplantation is the optimum treatment for patients with type 1 diabetes and renal failure, providing survival benefit over deceased donor kidney transplant alone. Here the authors demonstrate that utilization of donation after circulatory death pancreases is a safe approach to expanding the donor pool with equivalent results to donation after brainstem death transplantation. They also demonstrate that pancreas transplantation after normothermic regional perfusion is feasible, but it will require ongoing prospective study to ensure that the benefits seen for liver transplantation do not come at the expense of pancreas transplant outcomes.

Biochemical Effects of Silver Nanomaterials in Human Hepatocellular Carcinoma (HepG2) Cells

In dose-response and structure-activity studies, human hepatic HepG2 cells were exposed to between 0.01 and 300 ug/ml of different silver nanomaterials and AgNO₃ for 3 days. Treatment chemicals included a custom synthesized rod shaped nano Ag, a glutathione capped nano Ag, polyvinylpyrrolidone (PVP) capped nano Ag (75 nm) from Nanocomposix and AgNO₃. Various biochemical parameters were then evaluated to study cytotoxicity, cell growth, hepatic function and oxidative stress. Few indications of cytotoxicity were observed between 0.1 ug/ml and 6 ug/ml of any nano Ag. At 10 ug/ml and above, Ag containing nanomaterials caused a moderate to severe degree of cytotoxicity in HepG2 cells. Lactate dehydrogenase and aspartate transaminase activity alterations were the most sensitive cytotoxicity parameters. Some biochemical parameters were altered by exposures to both nano Ag and AgNO₃ (statistically significant increases in alkaline phosphatase, gamma glutamyltranspeptidase, glutathione peroxidase and triglycerides; in contrast both glutathione reductase and HepG2 protein concentration were both decreased). Three parameters were significantly altered by nano Ag but not by AgNO₃ (decreases in glucose 6-phosphate dehydrogenase and thioredoxin reductase and increases in catalase). Cytotoxicity per se did not appear to fully explain the patterns of biological responses observed. Some of the observations with the three nano Ag (increases in alkaline phosphatase, catalase, gamma glutamyltranspeptidase, as well as decreases in glucose 6-phosphate dehydrogenase and glutathione reductase) are in the same direction as HepG2 responses to other nanomaterials composed of TiO₂, CeO₂, SiO₂, CuO and Cu. Therefore, these biochemical responses may be due to micropinocytosis of nanomaterials, membrane damage, oxidative stress and/or cytotoxicity. Decreased G6PDH (by all three nano Ag forms) and GRD activity (only nano Ag R did not cause decreases) support and are consistent with the oxidative stress theory of Ag nanomaterial action.

Competing Timescales Lead to Oscillations in Shear-Thickening Suspensions

Competing timescales generate novelty. Here, we show that a coupling between the timescales imposed by instrument inertia and the formation of interparticle frictional contacts in shear-thickening suspensions leads to highly asymmetric shear-rate oscillations. Experiments tuning the presence of oscillations by varying the two timescales support our model. The observed oscillations give access to a shear-jamming portion of the flow curve that is forbidden in conventional rheometry. Moreover, the oscillation frequency allows us to quantify an intrinsic relaxation time for particle contacts. The coupling of fast contact network dynamics to a slower system variable should be generic to many other areas of dense suspension flow, with instrument inertia providing a paradigmatic example.

Constraint-Based Approach to Granular Dispersion Rheology

We present a phenomenological model for granular suspension rheology in which particle interactions enter as constraints to relative particle motion. By considering constraints that are formed and released by stress respectively, we derive a range of experimental flow curves in a single treatment and predict singularities in viscosity and yield stress consistent with literature data. Fundamentally, we offer a generic description of suspension flow that is independent of bespoke microphysics.

Automated vocal analysis of naturalistic recordings from children with autism, language delay, and typical development

For generations the study of vocal development and its role in language has been conducted laboriously, with human transcribers and analysts coding and taking measurements from small recorded samples. Our research illustrates a method to obtain measures of early speech development through automated analysis of massive quantities of day-long audio recordings collected naturalistically in children's homes. A primary goal is to provide insights into the development of infant control over infrastructural characteristics of speech through large-scale statistical analysis of strategically selected acoustic parameters. In pursuit of this goal we have discovered that the first automated approach we implemented is not only able to track children's development on acoustic parameters known to play key roles in speech, but also is able to differentiate vocalizations from typically developing children and children with autism or language delay. The method is totally automated, with no human intervention, allowing efficient sampling and analysis at unprecedented scales. The work shows the potential to fundamentally enhance research in vocal development and to add a fully objective measure to the battery used to detect speech-related disorders in early childhood. Thus, automated analysis should soon be able to contribute to screening and diagnosis procedures for early disorders, and more generally, the findings suggest fundamental methods for the study of language in natural environments.

SMAD4 mutations found in unselected HHT patients

BACKGROUND

Hereditary haemorrhagic telangiectasia (HHT) is an autosomal dominant disease exhibiting multifocal vascular telangiectases and arteriovenous malformations. The majority of cases are caused by mutations in either the endoglin (ENG) or activin receptor-like kinase 1 (ALK1, ACVRL1) genes; both members of the transforming growth factor (TGF)-beta pathway. Mutations in SMAD4, another TGF-beta pathway member, are seen in patients with the combined syndrome of juvenile polyposis (JP) and HHT (JP-HHT).

METHODS

We sought to determine if HHT patients without any apparent history of JP, who were undergoing routine diagnostic testing, would have mutations in SMAD4. We tested 30 unrelated HHT patients, all of whom had been referred for DNA based testing for HHT and were found to be negative for mutations in ENG and ALK1.

RESULTS

Three of these people harboured mutations in SMAD4, a rate of 10% (3/30). The SMAD4 mutations were similar to those found in other patients with the JP-HHT syndrome.

CONCLUSIONS

The identification of SMAD4 mutations in HHT patients without prior diagnosis of JP has significant and immediate clinical implications, as these people are likely to be at risk of having JP-HHT with the associated increased risk of gastrointestinal cancer. We propose that routine DNA based testing for HHT should include SMAD4 for samples in which mutations in neither ENG nor ALK1 are identified. HHT patients with SMAD4 mutations should be screened for colonic and gastric polyps associated with JP.

Molecular pharmacology of aromatase and its regulation by endogenous and exogenous agents

Aromatase (estrogen synthase) is the cytochrome P450 enzyme complex that converts C19 androgens to C18 estrogens. Aromatase activity has been demonstrated in breast tissue in vitro, and expression of aromatase is highest in or near breast tumor sites. Thus, local regulation of aromatase by both endogenous factors as well as exogenous medicinal agents will influence the levels of estrogen available for breast cancer growth. The prostaglandin E2 (PGE2) increases intracellular cAMP levels and stimulates estrogen biosynthesis, and our recent studies have shown a strong linear association between CYP19 expression and the sum of COX-1 and COX-2 expression in breast cancer specimens. PGE2 can bind to four receptor subtypes, EP1-EP4, which are coupled to different intracellular signaling pathways. In primary human breast stromal cell cultures, aromatase activity was significantly induced by PGE2, dexamethasone, and agonists for the EP1 and EP2 receptor subtypes. An EP1 antagonist, SC-19220, inhibited the induction of enzyme activity by PGE2 or 17-phenyltrinor-PGE2, an EP1 agonist. Sulprostone, an EP3 agonist, did not alter aromatase activity levels. Investigations are also underway on the regulation of aromatase by exogenous medicinal agents. Selective steroidal and nonsteroidal agents are effective in inhibiting breast tissue aromatase. The benzopyranone ring system is a molecular scaffold of considerable interest, and this scaffold is found in certain flavonoid natural products that have weak aromatase inhibitory activity. Our novel synthetic route for benzopyranones utilizes readily available salicylic acids and terminal alkynes as starting materials. The synthesis of flavones with diversity on the benzopyranone moiety and at the C-2 position occurs with good to excellent yields using these reaction conditions, resulting in an initial benzopyranone library of thirty compounds exhibiting enhanced and differential aromatase inhibition. Current medicinal chemistry efforts focus on diversifying the benzopyranone scaffold and utilizing combinatorial chemistry approaches to construct small benzopyranone libraries as potential aromatase inhibitors.

Diagnostic and therapeutic dilemmas in the management of pediatric-onset bipolar disorder

Although the diagnosis of pediatric-onset bipolar disorder is controversial, an increasing literature of systematic research has challenged the traditional view that this disorder is a rare condition. This article summarizes research regarding the atypical presentation of pediatric bipolar disorder and its overlap with attention-deficit/hyperactivity disorder and other comorbid conditions, as well as family-genetic and treatment data. When structured interview data were examined, cases of pediatric mania constituted 16% of referrals to our outpatient clinic. Presentation is atypical by adult standards and includes irritability, chronicity, and mixed state. Family-genetic and treatment data help to establish diagnostic validity. Pediatric bipolar disorder is not a rare condition. Treatment requires a combined pharmacotherapy approach to address issues of comorbidity. Atypical antipsychotic medications have provided promising treatment results, but additional controlled clinical trials are needed.

Expressed emotion and attributions in the relatives of bipolar patients: an analysis of problem-solving interactions

Among the relatives of schizophrenic and depressed patients, high expressed emotion (EE) attitudes are associated with "controllability attributions" about the causes of patients' symptoms and problem behaviors. However, previous studies have judged EE attitudes and causal attributions from the same assessment measure, the Camberwell Family Interview (CFI; C. E. Vaughn & J. P. Leff, 1976). The authors examined causal attributions among relatives of 47 bipolar patients, as spontaneously expressed to patients in family problem-solving interactions during a postillness period. Relatives rated high EE during the patients' acute episode (based on the CFI) were more likely than relatives rated low EE to spontaneously attribute patients' symptoms and negative behaviors to personal and controllable factors during the postillness interactional assessment. Thus, the EE-attribution linkage extends to the relatives of bipolar patients evaluated during a family interaction task.

Expressed emotion and attributions in the relatives of bipolar patients: an analysis of problem-solving interactions

Among the relatives of schizophrenic and depressed patients, high expressed emotion (EE) attitudes are associated with "controllability attributions" about the causes of patients' symptoms and problem behaviors. However, previous studies have judged EE attitudes and causal attributions from the same assessment measure, the Camberwell Family Interview (CFI; C. E. Vaughn & J. P. Leff, 1976). The authors examined causal attributions among relatives of 47 bipolar patients, as spontaneously expressed to patients in family problem-solving interactions during a postillness period. Relatives rated high EE during the patients' acute episode (based on the CFI) were more likely than relatives rated low EE to spontaneously attribute patients' symptoms and negative behaviors to personal and controllable factors during the postillness interactional assessment. Thus, the EE-attribution linkage extends to the relatives of bipolar patients evaluated during a family interaction task.

Family-focused treatment of bipolar disorder: 1-year effects of a psychoeducational program in conjunction with pharmacotherapy

BACKGROUND

Few studies have examined the combined effects of psychosocial treatment and pharmacotherapy for bipolar disorder. This study used a randomized, controlled design to examine a 9-month, manual-based program of family-focused psychoeducational treatment (FFT).

METHODS

Bipolar patients (N = 101) were recruited shortly after an illness episode and randomly assigned to 21 sessions of FFT (n = 31) or to a comparison treatment involving two family education sessions and follow-up crisis management (CM; n = 70). Both treatments were delivered over 9 months; patients were simultaneously maintained on mood stabilizing medications. Patients were evaluated every 3 months for 1 year as to relapse status, symptom severity, and medication compliance.

RESULTS

Patients assigned to FFT had fewer relapses and longer delays before relapses during the study year than did patients in CM. Patients in FFT also showed greater improvements in depressive (but not manic) symptoms. The most dramatic improvements were among FFT patients whose families were high in expressed emotion. The efficacy of FFT could not be explained by differences among patients in medication regimes or compliance.

CONCLUSIONS

Family-focused psychoeducational treatment appears to be an efficacious adjunct to pharmacotherapy for bipolar disorder. Future studies should evaluate family treatment against other forms of psychotherapy matched in amount of therapist-patient contact.

Ginkgo biloba extract: mechanisms and clinical indications

OBJECTIVE

Ginkgo biloba may have a role in treating impairments in memory, cognitive speed, activities of daily living (ADL), edema, inflammation, and free-radical toxicity associated with traumatic brain injury (TBI), Alzheimer's dementia, stroke, vasoocclusive disorders, and aging. The purpose of this review is to provide a synthesis of the mechanisms of action, clinical indications, and safety of Ginkgo biloba extract.

DATA SOURCES

Empirical studies, reviews, chapters, and conference proceedings were identified in the following databases: Medline, the Research Council for Complementary Medicine based on the British Library database, and Psychlnfo. Ginkgo biloba, EGb 761, Tanakan, Tebonin, Rokan, and LI 1370 were the principal index terms.

STUDY SELECTION AND DATA EXTRACTION

Controlled clinical studies with both positive and negative findings are included, in addition to animals studies illustrating mechanisms of activity.

DATA SYNTHESIS

Ginkgo has shown activity centrally and peripherally, affecting electrochemical, physiologic, neurologic, and vascular systems in animals and humans with few adverse side effects or drug interactions. Ginkgo shows promise in patients with dementia, normal aging, and cerebrovascular-related disorders. Clinical indications include memory, information processing, and ADL.

CONCLUSIONS

Ginkgo shows promise in treating some of the neurologic sequelae associated with Alzheimer's disease, TBI, stroke, normal aging, edema, tinnitus, and macular degeneration. Mechanisms of action may include antioxidant, neurotransmitter/receptor modulatory, and antiplatelet activating factor properties. While safe, caution is advised when recommending ginkgo to patients taking anticoagulants. Future studies should examine dose effects, component activity, mechanisms, and clinical applications.

Bipolar disorder and family communication: effects of a psychoeducational treatment program

Family psychoeducational programs are efficacious adjuncts to pharmacotherapy for patients with schizophrenic and bipolar disorders, but little is known about what these programs change about families. The authors assessed changes in face-to-face interactional behavior over 1 year among families of bipolar patients who received a 9-month family-focused psychoeducational therapy (FFT; n = 22) or crisis management with naturalistic follow-up (CMNF; n = 22), both administered with maintenance pharmacotherapy. Members of families who received FFT showed more positive nonverbal interactional behavior during a 1-year posttreatment problem-solving assessment than families who received CMNF, although no corresponding decreases were seen in negative interactional behaviors. The positive effect of family treatment on patients' symptom trajectories over 1 year was partially mediated by increases in patients' positive nonverbal interactional behaviors during this same interval.

Bipolar disorder and family communication: effects of a psychoeducational treatment program

Family psychoeducational programs are efficacious adjuncts to pharmacotherapy for patients with schizophrenic and bipolar disorders, but little is known about what these programs change about families. The authors assessed changes in face-to-face interactional behavior over 1 year among families of bipolar patients who received a 9-month family-focused psychoeducational therapy (FFT; n = 22) or crisis management with naturalistic follow-up (CMNF; n = 22), both administered with maintenance pharmacotherapy. Members of families who received FFT showed more positive nonverbal interactional behavior during a 1-year posttreatment problem-solving assessment than families who received CMNF, although no corresponding decreases were seen in negative interactional behaviors. The positive effect of family treatment on patients' symptom trajectories over 1 year was partially mediated by increases in patients' positive nonverbal interactional behaviors during this same interval.

Effect of a single bolus of intracoronary basic fibroblast growth factor on perfusion in an ischemic porcine model

Basic fibroblast growth factor (bFGF) has been shown to induce angiogenesis in various animal models, but the methods of administration used experimentally are not clinically feasible. The objective of this study was to determine whether a single intracoronary bolus injection of bFGF would improve coronary perfusion in a porcine ischemic model that mimics clinical chronic ischemia. A copper coil studded with gold was delivered into the proximal right coronary artery of juvenile Yorkshire pigs and deployed by interventional techniques. After a four-week interval for stenosis maturation, bFGF (100 micrograms) was administered by bolus injection into the left coronary artery in five animals, and vehicle alone was administered in four animals. Angiogenesis and change in right coronary perfusion area were assessed two weeks later by angiography, myocardial contrast echocardiography and immunohistochemistry. The right coronary perfusion area increased significantly after treatment in all but one of the animals that received bFGF but not in any of the controls. Intimal hyperplasia was not induced by bFGF. Capillary density determined histochemically was not different in the two groups. In conclusion, in a porcine ischemic model, bFGF administered by a single bolus intracoronary injection into the contralateral artery improved antegrade perfusion into the ischemic territory although without histological evidence of angiogenesis. This preliminary work merits further investigation.

Comparison of the hospital cost of primary and revision total hip arthroplasty after cost containment

This study compared the hospital cost of primary and revision total hip arthroplasty (THA) after the introduction of cost-containment programs (clinical pathway, hip implant standardization, and competitive bid purchasing of hip implants). Hospital financial records for 290 primary and 85 revision THAs performed from October 1993 through September 1995 were analyzed. A cost-accounting system provided actual hospital cost data for each procedure. Accurate calculation of hospital income or loss was determined. Average hospital length of stay was 4.9 days for primary THA and 5.9 days for revision THA. Average hospital cost was $11,104 for primary THA and $14,935 for revision THA. Average net income (hospital revenue hospital expense) for primary THA was $2486. Average loss from revision THA was $401. The payer mix included commercial insurance, Blue Cross/Blue Shield, managed care, Medicare, Medicaid, and workmen's compensation. For primary THA, all payers were profitable except Medicaid and selected managed care contracts. For revision THA, profit was achieved with payment from commercial insurance only. Despite the introduction of cost-containment programs, revision THA did not achieve profitability at our institution.

Comparison of the hospital cost of primary and revision total knee arthroplasty after cost containment

Revision total knee arthroplasty (TKA) consumes more time, more work, and more supplies than primary TKA. This study compared the hospital cost of primary and revision TKA after the introduction of cost-containment programs (implant standardization, clinical pathway, and competitive bid implant purchasing) at our hospital. Hospital financial records of 207 primary unilateral TKA operations and 32 revision TKA operations performed from October 1993 through September 1995 were analyzed. A cost-accounting system provided actual hospital cost data for each procedure. Accurate calculation of hospital income or loss was determined for all 239 procedures. The average hospital length of stay was 4.7 days for primary unilateral TKA and 5.1 days for revision TKA. There were 26 three-component revision operations and 6 one- or two-component revision operations. The average hospital cost was $10,421 for primary TKA and $11,906 for revision TKA. The average net hospital income (hospital revenue - hospital expense) was $3211 for primary TKA and $1853 for revision TKA. The payer mix included indemnity insurance, Medicare, Medicaid, managed care, and workmen's compensation. All payers were profitable except for Medicaid and selected managed care contracts for both primary and revision TKA. As a result of cost-containment programs, revision TKA can be profitable at our institution.

Opportunities for control of hospital costs for total joint arthroplasty after initial cost containment

Financial analysis of 391 joint replacement operations performed during 1996 determined that almost 80% of the hospital cost for joint replacement procedures was generated in the operating room, nursing units, recovery room, and pharmacy during the first 48 hours of hospitalization. Attempts to control or reduce the hospital cost of joint replacement operations should focus on these specific areas of opportunity.

Opportunities for control of hospital cost for total knee arthroplasty

The hospital financial records of 120 consecutive patients who underwent unilateral knee replacement surgery at one hospital during 1995 were reviewed to determine opportunities for control of hospital cost for total knee arthroplasty. The average hospital length of stay for these patients was 4.27 days (range, 3-10 days). The average hospital cost was $10,231. All 120 patients were classified under Diagnosis Related Group 209, principle procedure 81.54 primary total knee arthroplasty. Medicare paid for 70% of the patients. All payers were profitable except Medicaid and one managed care organization. When hospital cost for total knee arthroplasty was allocated to hospital service centers, 78% of the cost was attributed to the operating room, nursing units, recovery room, and pharmacy. When hospital cost for total knee arthroplasty was allocated to hospital days, 80% of the hospital cost occurred during the first 48 hours of hospitalization. Hospital reimbursement for total knee arthroplasty is primarily a prospective case price payment system. After initial cost containment efforts reduce the hospital length of stay for total knee arthroplasty to 4 to 6 days, additional control of hospital cost should focus on these areas of opportunity.

Global assessment of relational functioning scale (GARF): II. Reliability and validity in a sample of families of bipolar patients

The companion article by the Group for the Advancement of Psychiatry (GAP) Committee on the Family (see p. 155, this issue) describes the development of the Global Assessment of Relational Functioning (GARF) scale. The present study evaluated the reliability and concurrent validity of a manualized version of the GARF in recently episodic bipolar patients (N = 73) participating with family members in laboratory interaction tasks. The GARF was applied with high reliability by raters with little clinical experience. GARF ratings discriminated between families rated high and low in expressed emotion, with families rated as high in emotional overinvolvement showing the lowest relational functioning scores. GARF scores also correlated with affective negativity scores derived from the interactional task-based affective style and coping style coding systems. However, relational ratings were independent of levels of concurrent symptoms or illness chronicity among individual patients. GARF ratings may inform the treatment plans for patients with psychiatric disorders, but the optimal methods of data collection and rater training must be determined.

Nonverbal interactional behavior in the families of persons with schizophrenic and bipolar disorders

Whereas verbal interactional behaviors have been repeatedly found to distinguish the families of persons with and without major psychiatric disorders, there has been comparatively little examination of the discriminative value of nonverbal interactional behaviors. We developed the Nonverbal Interactional Coding System to measure "affiliative" and "distancing" nonverbal behaviors in 18 schizophrenic and 18 bipolar patients and their parents during 10-minute interactions conducted during a posthospital period. Bipolar patients and their parents displayed affiliative nonverbal behaviors ("illustrator gestures" or "prosocial behaviors") for longer durations than schizophrenic patients and their parents. In contrast, parents of schizophrenic patients displayed distancing nonverbal behaviors (looking away) for longer durations than those of bipolar patients. The nonverbal interactional data added to the statistical strength of patients' and parents' verbal interactional data in distinguishing between these diagnostic groups. Nonverbal interactional behaviors are important variables to consider in interventions aimed at improving the communication skills of families coping with psychiatric disorders.

Battering in a population of adolescent females

The purpose of this study was to assess the prevalence of battering in a population of adolescent females, to gain information regarding the impact of battering on their health, and to test a portion of the Campbell and Humphreys (1984) framework, which states that our patriarchal society and the resulting machismo attitudes toward women are the cause of battering. If the framework is correct, partners who batter would possess characteristics indicative of machismo. The sample for this descriptive study consisted of a convenience sample of 59 females from a shelter for displaced teens. The subjects provided information on themselves and 92 male partners via interviews. Of 59 subjects, 69% had been battered before the age of 18 and 41.5% had been battered during pregnancy. Health care problems were frequent in all the subjects, especially depression and suicidal ideation. The nonbattered and battered subjects as well as their partners were compared with respect to several demographic variables. There was a statistically significant higher rate of reported qualities of machismo among batterers when compared with nonbatterers. Recommendations include suggestions for further research.

Effect of monoclonal antihuman IgE on recombinant IgE(301-376) inhibition of specific IgE histamine release

To explore the binding domains of rCIgE(301-376) necessary for inhibition of passive transfer of rye grass and Chinese elm IgE to human basophils, we employed monoclonal antibodies known to bind to IgE(301-336), M-272, and to IgE(367-376), M-27. By preincubating M-272, but not M-27, with rCIgE(301-376), passive transfer of specific IgE to basophils was partially inhibited. This implies that M-272 recognizes a binding site on rCIgE(301-376) or sterically interferes with the rCIgE(301-376) high-affinity binding domains on human basophils.

High performance liquid chromatography assay for piroxicam in pharmaceutical products

A high performance liquid chromatographic assay for piroxicam in pharmaceutical preparations is described. The method uses a reversed-phase C18 column with pH 3 aqueous buffer/methanol, 55:45, v/v mobile phase, and is selective for piroxicam in the presence of other "oxicams," synthetic precursors, by-products, degradation products, metabolites, and related compounds. Applications to capsules, tablets, ointments, suppositories, ophthalmic suspensions, and rodent feeds are cited.

Kinetic evaluation of carrier-mediated transport of ouabain and taurocholic acid in isolated rat hepatocytes. Evidence for independent transport systems

Ouabain and taurocholic acid (Tch) share in common the cyclopentanophenanthrene (steroid) nucleus, and both are concentrated in the liver by hepatic sinusoidal carrier-mediated transport processes. Multiple transport systems for Tch uptake have been implicated, and Tch is an effective inhibitor of ouabain uptake. To determine if the ouabain transport system is related to transport of Tch, kinetic studies were conducted to examine the nature of cross-inhibition of ouabain and Tch. Tch was found to inhibit ouabain uptake in a competitive manner, with a Ki approximately ten times less than the Km for ouabain. However, ouabain failed to inhibit total Tch uptake in a competitive manner when added to the system at the same time as the Tch substrate. Preincubation of cells with ouabain resulted in noncompetitive inhibition of sodium-dependent Tch uptake but had no effect on sodium-independent Tch uptake. Ouabain had a weak competitive inhibitory effect on sodium-independent transport of Tch, but the Ki was approximately ten times greater than the Km for ouabain. These results demonstrate that the ouabain transport system is distinct from both the sodium-dependent and sodium-independent transport systems for Tch. Tch apparently binds competitively to the ouabain transport system but is not effectively transported across the cell membrane by this system.

Photoionisation and Auger Electron Emission from the Lithium Molecule: Calculations using Multicentre Numerical Continuum Functions

A numerical method has been used for the generation of molecular continuum wavefunctions at the relaxed Hartree-Fock level associated with the photoionisation of the lithium molecule. Exchange between the continuum electron and the ion core is included, but L coupling is neglected. Cross sections for core and valence shell photoionisation have been calculated from threshold to 6�0 a. u. The results differ significantly in detail from previous multiple scattering calculations. Continuum phase shifts and the asymmetry parameters for the various processes are also reported. The molecular cross section values are compared with atomic cross sections calculated at the relaxed Hartree-Fock level. The Li2 molecular Auger transition rates are also calculated from first principles using the appropriate two-centre continuum functions. The results provide a basis for the reinterpretation of recent experimental findings of photoemission data for the lithium vapour system.

Pixel labeling by supervised probabilistic relaxation

A simple modification to existing probabilistic relaxation procedures is suggested which allows the information contained in initial labels to exert an influence on the direction of relaxation throughout the process. In this manner, the initial labels assume more importance than with conventional algorithms and are used in combination with the outcome of relaxation at each iteration to produce a cooperative estimate of the correct label for a particular object. Pixel labeling examples are presented which show the performance that can be obtained with the modified algorithm. The procedure is readily generalized to allow other data to influence the process.