Training the next generation of pharmacometric modelers: a multisector perspective

The current demand for pharmacometricians outmatches the supply provided by academic institutions and considerable investments are made to develop the competencies of these scientists on-the-job. Even with the observed increase in academic programs related to pharmacometrics, this need is unlikely to change in the foreseeable future, as the demand and scope of pharmacometrics applications keep expanding. Further, the field of pharmacometrics is changing. The field largely started when Lewis Sheiner and Stuart Beal published their seminal papers on population pharmacokinetics in the late 1970's and early 1980's and has continued to grow in impact and use since its inception. Physiological-based pharmacokinetics and systems pharmacology have grown rapidly in scope and impact in the last decade and machine learning is just on the horizon. While all these methodologies are categorized as pharmacometrics, no one person can be an expert in everything. So how do you train future pharmacometricians? Leading experts in academia, industry, contract research organizations, clinical medicine, and regulatory gave their opinions on how to best train future pharmacometricians. Their opinions were collected and synthesized to create some general recommendations.

Causal chemoprophylactic activity of cabamiquine against Plasmodium falciparum in a controlled human malaria infection: a randomised, double-blind, placebo-controlled study in the Netherlands

BACKGROUND

Cabamiquine is a novel antimalarial that inhibits Plasmodium falciparum translation elongation factor 2. We investigated the causal chemoprophylactic activity and dose-exposure-response relationship of single oral doses of cabamiquine following the direct venous inoculation (DVI) of P falciparum sporozoites in malaria-naive, healthy volunteers.

METHODS

This was a phase 1b, randomised, double-blind, placebo-controlled, adaptive, dose-finding, single-centre study performed in Leiden, Netherlands. Malaria-naive, healthy adults aged 18-45 years were divided into five cohorts and randomly assigned (3:1) to receive cabamiquine or placebo. Randomisation was done by an independent statistician using codes in a permuted block schedule with a block size of four. Participants, investigators, and study personnel were masked to treatment allocation. A single, oral dose regimen of cabamiquine (200, 100, 80, 60, or 30 mg) or matching placebo was administered either at 2 h (early liver-stage) or 96 h (late liver-stage) after DVI. The primary endpoints based on a per-protocol analysis set were the number of participants who developed parasitaemia within 28 days of DVI, time to parasitaemia, number of participants with documented parasite blood-stage growth, clinical symptoms of malaria, and exposure-efficacy modelling. The impact of cabamiquine on liver stages was evaluated indirectly by the appearance of parasitaemia in the blood. The Clopper-Pearson CI (nominal 95%) was used to express the protection rate. The secondary outcomes were safety and tolerability, assessed in those who had received DVI and were administered one dose of the study intervention. The trial was prospectively registered on ClinicalTrials.gov (NCT04250363).

FINDINGS

Between Feb 17, 2020 and April 29, 2021, 39 healthy participants were enrolled (early liver-stage: 30 mg [n=3], 60 mg [n=6], 80 mg [n=6], 100 mg [n=3], 200 mg [n=3], pooled placebo [n=6]; late liver-stage: 60 mg [n=3], 100 mg [n=3], 200 mg [n=3], pooled placebo [n=3]). A dose-dependent causal chemoprophylactic effect was observed, with four (67%) of six participants in the 60 mg, five (83%) of six participants in the 80 mg, and all three participants in the 100 and 200 mg cabamiquine dose groups protected from parasitaemia up to study day 28, whereas all participants in the pooled placebo and 30 mg cabamiquine dose group developed parasitaemia. A single, oral dose of 100 mg cabamiquine or higher provided 100% protection against parasitaemia when administered during early or late liver-stage malaria. The median time to parasitaemia in those with early liver-stage malaria was prolonged to 15, 22, and 24 days for the 30, 60, and 80 mg dose of cabamiquine, respectively, compared with 10 days for the pooled placebo. All participants with positive parasitaemia showed documented blood-stage parasite growth, apart from one participant in the pooled placebo group and one participant in the 30 mg cabamiquine group. Most participants did not exhibit any malaria symptoms in both the early and late liver-stage groups, and those reported were mild in severity. A positive dose-exposure-efficacy relationship was established across exposure metrics. The median maximum concentration time was 1-6 h, with a secondary peak observed between 6 h and 12 h in all cabamiquine dose groups (early liver-stage). All cabamiquine doses were safe and well tolerated. Overall, 26 (96%) of 27 participants in the early liver-stage group and ten (83·3%) of 12 participants in the late liver-stage group reported at least one treatment-emergent adverse event (TEAE) with cabamiquine or placebo. Most TEAEs were of mild severity, transient, and resolved without sequelae. The most frequently reported cabamiquine-related TEAE was headache. No dose-related trends were observed in the incidence, severity, or causality of TEAEs.

INTERPRETATION

The results from this study show that cabamiquine has a dose-dependent causal chemoprophylactic activity. Together with previously demonstrated activity against the blood stages combined with a half-life of more than 150 h, these results indicate that cabamiquine could be developed as a single-dose monthly regimen for malaria prevention.

FUNDING

The healthcare business of Merck KGaA, Darmstadt, Germany.

Translation of liver stage activity of M5717, a Plasmodium elongation factor 2 inhibitor: from bench to bedside

Background

Targeting the asymptomatic liver stage of Plasmodium infection through chemoprevention could become a key intervention to reduce malaria-associated incidence and mortality.

Methods

M5717, a Plasmodium elongation factor 2 inhibitor, was assessed in vitro and in vivo with readily accessible Plasmodium berghei parasites. In an animal refinement, reduction, replacement approach, the in vitro IC₉₉ value was used to feed a Population Pharmacokinetics modelling and simulation approach to determine meaningful effective doses for a subsequent Plasmodium sporozoite-induced volunteer infection study.

Results

Doses of 100 and 200 mg would provide exposures exceeding IC₉₉ in 96 and 100% of the simulated population, respectively.

Conclusions

This approach has the potential to accelerate the search for new anti-malarials, to reduce the number of healthy volunteers needed in a clinical study and decrease and refine the animal use in the preclinical phase.

Graphical Abstract

Pharmacokinetics and exposure-efficacy relationships of omalizumab in patients with nasal polyps

The anti-immunoglobulin E (IgE) antibody, omalizumab (Xolair), is approved in the United States for the treatment of allergic asthma and chronic spontaneous urticaria, and has recently been studied for the treatment of nasal polyposis following completion of the two replicate phase 3 studies (POLYP 1 and POLYP 2). The dosing of omalizumab used in the phase 3 studies is based on a combination of patients' pre-treatment IgE level and body weight, similar to the approach used in allergic asthma. The objectives of the current analyses were to evaluate whether the pharmacokinetics (PK) of omalizumab and its pharmacodynamic (PD) effect on free and total IgE level in chronic rhinosinusitis with nasal polyps (CRSwNP) are consistent with those in allergic asthma via population PK/PD modeling and simulation, and to graphically explore exposure-response relationships and free IgE-response relationships in CRSwNP. Omalizumab PK and PD effect of total and free IgE in CRSwNP are generally consistent with those in asthma. Observed post-treatment free IgE suppressions were generally within the target range of the baseline IgE- and body weight-based omalizumab dosing table, with 74.2% and 93.0% of patients achieving a serum free IgE level below 25 ng/mL and 50 ng/mL, respectively at Week 24. Exposure-response analyses indicated that there was no clear correlation between omalizumab or free IgE concentration and key efficacy endpoints within the POLYP studies. Overall, these results indicate that the body weight and IgE-based dosing regimen of omalizumab was appropriate for use in CRSwNP patients.

Population Pharmacokinetics of Ipatasertib and Its Metabolite in Cancer Patients

Ipatasertib is a selective AKT kinase inhibitor currently in development for the treatment of several solid tumors, including breast and prostate cancers. This study was undertaken to characterize pharmacokinetic profiles of ipatasertib and its metabolite M1 (G-037720) and to understand the sources of variability. Population pharmacokinetic models of ipatasertib and M1 were developed separately using data from 342 individuals with cancer from 5 phase 1 and 2 studies. The final population pharmacokinetic models for ipatasertib and M1 were 3-compartmental, with first-order elimination and sequential zero- and first-order absorption. Ipatasertib bioavailability and M1 formation increased after multiple dosing, resulting in an increase in exposure beyond that expected from accumulation alone. Covariate effects of ipatasertib include decreased oral clearance with increasing age and with coadministration of abiraterone, as well as decreased bioavailability with increasing weight. For ages 37 and 80 years, steady-state area under the curve (AUC_ss ) was predicted to be 81% and 109%, respectively, of the typical population value (64 years). For body weight of 49 and 111 kg, AUC_ss was predicted to be 132% and 78%, respectively, of the typical population value (75 kg). The small magnitude of change in ipatasertib exposure is not likely to be clinically relevant. For M1, the peripheral distribution volume and intercompartmental clearance increased with increasing weight. Coadministration of abiraterone was estimated to increase M1 exposure by 61% at steady state. Mild and moderate renal impairment, mild hepatic impairment, and race were not identified as significant covariates in the final models for ipatasertib and M1.

Selection of the Recommended Phase 2 Dose for Bintrafusp Alfa, a Bifunctional Fusion Protein Targeting TGF-β and PD-L1

Bintrafusp alfa, a first‐in‐class bifunctional fusion protein composed of the extracellular domain of the TGF‐βRII receptor (TGF‐β “trap”) fused to a human IgG1‐blocking PD‐L1, showed a manageable safety profile and clinical activity in phase I studies in patients with heavily pretreated advanced solid tumors. The recommended phase 2 dose (RP2D) was selected based on integration of modeling, simulations, and all available data. A 1,200‐mg every 2 weeks (q2w) dose was predicted to maintain serum trough concentration (C_trough) that inhibits all targets of bintrafusp alfa in circulation in > 95% of patients, and a 2,400‐mg every 3 weeks (q3w) dose was predicted to have similar C_trough. A trend toward an association between exposure and efficacy variables and a relatively stronger inverse association between clearance and efficacy variables were observed. Exposure was either weakly or not correlated with probability of adverse events. The selected intravenous RP2D of bintrafusp alfa is 1,200 mg q2w or 2,400 mg q3w.

Population Pharmacokinetics and Pharmacodynamics of the Calcimimetic Etelcalcetide in Chronic Kidney Disease and Secondary Hyperparathyroidism Receiving Hemodialysis

Etelcalcetide is a novel calcimimetic in development for the treatment of secondary hyperparathyroidism (SHPT). A population pharmacokinetic/pharmacodynamic (PK/PD) model was developed relating etelcalcetide exposures to markers of efficacy (parathyroid hormone [PTH]) and safety (calcium) using data from three clinical studies. The semimechanistic model was developed that included allosteric activation pharmacology and understanding of calcium homeostasis. The temporal profiles for all biomarkers were well described by the model. The cooperativity constant was 4.94, confirming allosteric activation mechanism. Subjects with more severe disease (higher PTH baseline) were predicted to experience less pronounced reduction in PTH (percentage change from baseline), but more reduction in calcium (Ca; percentage change from baseline). There was no evidence that dose adjustment by any covariate was needed. Model‐based simulations provided quantitative support to several elements of dosing, such as starting dose, monitoring, and titration timing for registration trials.

Viral Load and Neuropsychological Functioning in HIV Seropositive Individuals:A Preliminary Descriptive Study

We have theorized a direct relationship between viral burden and deleterious effects on the central nervous systems. It was hypothesized that HIV+ individuals would manifest poorer neuropsychological functioning after increased viral load. To address this, we compared viral burden to neuropsychological performance in subjects who participated in ACTG 116-118. Plasma samples and neuropsychological assessments completed at the same time were available for 64 observations on 21 subjects. Subjects who had a viral peak of over 1000 TCID per ml were classified as high viral load, those who did not as low viral load. Mean performances of the high viral load subjects were poorer, even though baseline performances were slightly poorer in the low viral load group. Mean post-viral peak performances were poorer than pre-viral peak performances. Declines in neuropsychological performance were found significantly more often in the high viral load group. These findings support the viral load hypothesis.

Investigating surface topology and cyclic-RGD peptide functionalization on vascular endothelialization

The advantages of endothelialization of a stent surface in comparison with the bare metal and drug-eluting stents used today include reduced late-stent restenosis and in-stent thrombosis. In this article, we study the effect of surface topology and functionalization of tantalum (Ta) with cyclic-(arginine-glycine-aspartic acid-d-phenylalanine-lysine) (cRGDfK) on the attachment, spreading, and growth of vascular endothelial cells. Self-assembled nanodimpling on Ta surfaces was performed using a one-step electropolishing technique. Next, cRGDfK was covalently bonded onto the surface using silane chemistry. Our results suggest that nanotexturing alone was sufficient to enhance cell spreading, but the combination of a nanodimpled surfaces along with the cRGDfK peptide may produce a better endothelialization coating on the surface in terms of higher cell density, better cell spreading, and more cell-cell interactions, when compared to using cRGDfK peptide functionalization alone or nanotexturing alone. We believe that future research should look into how to implement both modifications (topographic and chemical modifications) to optimize the stent surface for endothelialization.

Identification of the Transmembrane Glucose Regulated Protein 78 as a Biomarker for the Brain Cancer Glioblastoma Multiforme by Gene Expression and Proteomic Studies

The prognosis of patients with Glioblastoma Multiforme (GBM), the most malignant adult glial brain tumor, remains poor in spite of advances in treatment procedures, including surgical resection, irradiation and chemotherapy. Genetic heterogeneity of GBM warrants extensive studies to gain a thorough understanding of the biology of this tumor. While there have been several studies of global transcript profiling of glioma with the identification of gene signatures for diagnosis and disease management, translation into clinics is yet to happen. In the present study, we report a novel proteomic approach by using two-dimensional difference gel electrophoresis (2D-DIGE) followed by spot picking and analysis of proteins/peptides by Mass Spectrometry. We report Glucose Regulated Protein 78 (GRP78) as a differentially expressed protein in the GBM cell line compared to human normal Astrocyte cells.

In addition to proteomic studies, we performed microarray analysis which further confirmed up regulation of GRP78 in GBM cells compared to human normal Astrocyte cells.

GRP78 has long been recognized as a molecular chaperone in the endoplasmic reticulum (ER) and can be induced by the ER stress response. Besides its location in the ER, GRP78 has been found in cell plasma membrane, cytoplasm, mitochondria, nucleus and other cellular secretions. GRP78 is implicated in tumor cell proliferation, apoptosis resistance, immune escape, metastasis and angiogenesis, and its elevated expression usually correlates with a variety of tumor micro environmental stresses, including hypoxia, glucose deprivation, lactic acidosis and inflammatory response. GRP78 protein acts as a centrally located sensor of stress, which senses and facilitates the adaptation to the tumor microenvironment.

Our findings showed differential expression of this gene in brain cancer GBM and thus confirm similarities in findings in existing transcriptional and translational studies. Thus, these findings could be of further importance for diagnostic, therapeutic and prognostic approaches for dealing with this highly malignant cancer.

Single-dose pharmacokinetics and tolerability of oral delta-9- tetrahydrocannabinol in patients with amyotrophic lateral sclerosis

BACKGROUND

Cannabinoids exert neuroprotective and symptomatic effects in amyotrophic lateral sclerosis (ALS). We assessed the pharmacokinetics (PK) and tolerability of delta-9-tetrahydrocannabinol (THC) in ALS patients.

METHODS

Nine patients received THC single oral doses of 5mg and 10mg, separated by a wash-out period of two weeks. Blood samples for the determination of THC, 11-nor-9-carboxy-THC (THC-COOH) and hydroxy-THC (THC-OH) were taken up to 8 hours after intake. Adverse events were assessed by visual analogue scales (VAS). Plasma concentrations of the active metabolite THC-OH were submitted to sequential pharmacokinetic-pharmacodynamic population modeling on individual heart rate as a proxy for THC's cardiovasculatory effects.

RESULTS

Drowsiness, euphoria, orthostasis, sleepiness, vertigo and weakness were significantly more frequent in patients receiving 10mg compared to 5 mg THC. A marked interindividual variability was found for the absorption of oral THC (84%) and elimination of THC-COOH (45%). PK data did not support any clinically relevant deviation from linear PK in the investigated range of concentrations. Plasma concentrations of THC-OH were positively correlated with the individual heart rate. An E(max-model) was successfully fitted to individual heart rate, with a THC-OH plasma concentration of 3.2 x 10(-4) μmol/L for EC(50) and an E(max) of 93 bpm for heart rate.

CONCLUSIONS

The higher 10mg dose of THC was dose-limiting in patients with ALS. High interindividual PK variability requires individuell titration of THC for potential therapeutic use in patients with ALS.

Clinical experience with an antimicrobial hydrogel dressing on recalcitrant wounds

OBJECTIVE

To assess the performance of a newly-introduced, iodine-based antimicrobial wound dressing (Iodozyme) within normal clinical practice.

METHOD

51 case records were collected from 30 wound care locations in England. Reporting clinicians used Iodozyme on one or more difficult wounds of their own choice (of various aetiologies) from their current case loads. Basic patient-specific data were collected, relating to both their own and their patients' experience with the product over a 6-week period of treatment (or less, if healing was achieved earlier). In every case, the wound continued to be treated in accordance with local 'best practice', in accordance with the manufacturer's instructions and by the same clinician. Each wound was assessed in terms of size, condition (margins and wound bed), exudate (type and amount), comfort/pain, overall satisfaction (by patient and clinician) and healing status (in terms of healed, improved, static or deteriorated). In addition, clinicians were asked to use their own local criteria and parameters where possible, with general guidance as and when it was needed.

RESULTS

The mean duration of all wounds was 25.8 months (median 13 and range 1-312). Nine patients had a wound of less than six months' duration, and 17 had one of two years' or more duration. Within the 6-week study period, 6 wounds healed fully, 37 were judged to have improved, 7 remained static and 1 deteriorated. Overall, the majority of clinicians and patients were 'satisfied' or 'very satisfied' with product performance and 77% of clinicians concluded that the dressing was 'better' or 'much better' than other dressings they had previously used on similar wounds.

CONCLUSION

While we cannot generalise from this study, the encouraging clinical results and positive patient and clinician feedback lead us to believe that Iodozyme is a dressing worthy of consideration when treating chronic wounds. These encouraging preliminary findings are now to be followed up with a randomised control trial.

Phylogeny and growth strategy as predictors of differences in cobalt concentrations between plant species

Analyses reported here quantify the contribution of plant phylogeny and plant growth strategy to soil-to-plant transfer of Co. Estimated relative mean (ERM) Co concentrations in shoots of 241 species of flowering plant were derived using a residual maximum likelihood (REML) analysis. There were significant differences in, and a loge-normal frequency distribution of, ERM Co concentrations between species. A significant percentage of interspecies variance could be assigned to taxonomic categories above the species, (Family and above 21.5%; Order and above 12.22%). Time-series analysis of ERM Co concentrations ordered in the species-sequence of the Angiosperm Phylogeny Group (APG II (2003)) revealed significant autocorrelation with an increase from Commelinid Monocot to Asterid Eudicot and a pronounced peak in the Core Eudicots. ERM Co concentrations categorized by plant growth strategy sensu Grime (2001) showed an increase toward stress-tolerant strategies. Plant species are not, therefore, independent units of Co concentration--factors derived from higher levels of biological organization exert significant effects. These effects can provide the basis of new techniques for selecting plant species for biotechnologies and for predicting the exposure of organisms to Co. They show that plant phylogeny and growth strategy might help refine predictions of soil-to-plant transfer of a variety of pollutants, and suggest research that might link molecular and higher level processes in contaminated soil-plant systems.

275. The endocrine disruptor, bisphenol A, alters gene expression in the hypothalamus of the ram lamb but does not alter LH secretion

Bisphenol A (BPA) is an endocrine disruptor, which has both oestrogenic and anti-oestrogenic actions. It has profound effects on development, especially of sex organs but also on the brain. The actions on the brain are poorly understood and little is known about males. Most work has been conducted in fish & rodents, but the lifespan of domestic ruminants means that BPA may accumulate in tissues over many years. This study tested the hypothesis that treatment of ram lambs with BPA would alter LH secretion as well as gene activity in various hypothalamic regions. Ram lambs were treated from 1 month old with thrice weekly injections (im) of BPA (3.5 mg/kg) or vehicle (n = 10/group) for 80days. Weekly bodyweights and jugular blood samples were collected and on day 79, blood samples were taken every 15 min for 8 h for LH RIA. The sheep were killed, body & testicular weights collected and the hypothalamus dissected into anterior, dorsal and ventral blocks, then frozen in liquid nitrogen. Bodyweight (Cont. 26.0 ± 0.5 kg v. BPA 25.2 ± 0.7 kg) and paired testicular weight (Cont. 31.6 ± 1.2 g v. BPA 29.3 ± 1.4 g) did not significantly differ (P > 0.05). LH secretion also did not differ, in either mean LH concentrations (Cont 0.31 ± 0.14 v. BPA 0.29 ± 0.12ng/mL) or pulses/8 h (Cont 1.8 ± 0.4 v. BPA 2.0 ± 0.4). Total RNA was extracted from the basal hypothalamus (ventral block) and RNA from 2 treated and 2 control animals was hybridised on 44K Agilent bovine microarrays. Preliminary analysis suggests 118 probes were differentially expressed. Gene ontology analysis of these differentially expressed probes revealed involvement in a broad range of biological processes and cellular components. This study suggests that gene array analysis is a suitable tool with which to study BPA actions in the sheep hypothalamus. Future work will expand this pilot microarray study to include all animals and all hypothalamic regions.

Population pharmacokinetics and pharmacodynamics of paclitaxel and carboplatin in ovarian cancer patients: a study by the European organization for research and treatment of cancer-pharmacology and molecular mechanisms group and new drug development group

PURPOSE

Paclitaxel and carboplatin are frequently used in advanced ovarian cancer following cytoreductive surgery. Threshold models have been used to predict paclitaxel pharmacokinetic-pharmacodynamics, whereas the time above paclitaxel plasma concentration of 0.05 to 0.2 micromol/L (t(C > 0.05-0.2)) predicts neutropenia. The objective of this study was to build a population pharmacokinetic-pharmacodynamic model of paclitaxel/carboplatin in ovarian cancer patients.

EXPERIMENTAL DESIGN

One hundred thirty-nine ovarian cancer patients received paclitaxel (175 mg/m(2)) over 3 h followed by carboplatin area under the concentration-time curve 5 mg/mL*min over 30 min. Plasma concentration-time data were measured, and data were processed using nonlinear mixed-effect modeling. Semiphysiologic models with linear or sigmoidal maximum response and threshold models were adapted to the data.

RESULTS

One hundred five patients had complete pharmacokinetic and toxicity data. In 34 patients with measurable disease, objective response rate was 76%. Neutrophil and thrombocyte counts were adequately described by an inhibitory linear response model. Paclitaxel t(C > 0.05) was significantly higher in patients with a complete (91.8 h) or partial (76.3 h) response compared with patients with progressive disease (31.5 h; P = 0.02 and 0.05, respectively). Patients with paclitaxel t(C > 0.05) > 61.4 h (mean value) had a longer time to disease progression compared with patients with paclitaxel t(C > 0.05) < 61.4 h (89.0 versus 61.9 weeks; P = 0.05). Paclitaxel t(C > 0.05) was a good predictor for severe neutropenia (P = 0.01), whereas carboplatin exposure (C(max) and area under the concentration-time curve) was the best predictor for thrombocytopenia (P < 10(-4)).

CONCLUSIONS

In this group of patients, paclitaxel t(C > 0.05) is a good predictive marker for severe neutropenia and clinical outcome, whereas carboplatin exposure is a good predictive marker for thrombocytopenia.

A-272651, a nonpeptidic blocker of large-conductance Ca2+-activated K+ channels, modulates bladder smooth muscle contractility and neuronal action potentials

BACKGROUND AND PURPOSE

The large-conductance Ca(2+)-activated K(+) channel (BK(Ca), K(Ca)1.1) links membrane excitability with intracellular Ca(2+) signaling and plays important roles in smooth muscle contraction, neuronal firing, and neuroendocrine secretion. This study reports the characterization of a novel BK(Ca) channel blocker, 2,4-dimethoxy-N-naphthalen-2-yl-benzamide (A-272651).

EXPERIMENTAL APPROACH

(86)Rb(+) efflux in HEK-293 cells expressing BK(Ca) was measured. Effects of A-272651 on BK(Ca) alpha- and BK(Ca) alphabeta1-mediated currents were evaluated by patch-clamp. Effects on contractility were assessed using low-frequency electrical field stimulated pig detrusor and spontaneously contracting guinea pig detrusor. Effects of A-272651 on neuronal activity were determined in rat small diameter dorsal root ganglia (DRG).

KEY RESULTS

A-272651 (10 microM) inhibited (86)Rb(+) efflux evoked by NS-1608 in HEK-293 cells expressing BK(Ca) currents. A-272651 concentration-dependently inhibited BK(Ca) currents with IC(50) values of 4.59 microM (Hill coefficient 1.04, measured at +40 mV), and 2.82 microM (Hill coefficient 0.89), respectively, for BK(Ca) alpha and BK(Ca) alphabeta1-mediated currents. Like iberiotoxin, A-272651 enhanced field stimulated twitch responses in pig detrusor and spontaneous contractions in guinea pig detrusor with EC(50) values of 4.05+/-0.05 and 37.95+/-0.12 microM, respectively. In capsaicin-sensitive DRG neurons, application of A-272651 increased action potential firing and prolonged action potential duration.

CONCLUSIONS AND IMPLICATIONS

These data demonstrate that A-272651 modulates smooth muscle contractility and neuronal firing properties. Unlike previously reported peptide BK(Ca) blockers, A-272651 represents one of the first small molecule BK(Ca) channel blockers that could serve as a useful tool for further characterization of BK(Ca) channels in physiological and pathological states.

Population pharmacokinetics of rifapentine and its primary desacetyl metabolite in South African tuberculosis patients

This study was designed to describe the population pharmacokinetics of rifapentine (RFP) and 25-desacetyl RFP in a South African pulmonary tuberculosis patient population. Special reference was made to studying the influence of previous exposure to rifampin (RIF) and the variability in pharmacokinetic parameters between patients and between occasions and the influence of different covariates. Patients were included in the study if they had been receiving first-line antimycobacterial therapy (rifampin, isoniazid, pyrazinamide, and ethambutol) for not less than 4 weeks and not more than 6 weeks and were divided into three RFP dosage groups based on weight: 600 mg, <45 kg; 750 mg, 46 to 55 kg; and 900 mg, >55 kg. Participants received a single oral dose of RFP together with concomitant antimycobacterial agents, excluding RIF, on study days 1 and 5 after they ingested a soup-based meal. The RFP and 25-desacetyl RFP concentration-time data were analyzed by nonlinear mixed-effect modeling using NONMEM. The pharmacokinetics of the parent drug were modeled separately, and the individual pharmacokinetic parameters were used as inputs for the 25-desacetyl RFP pharmacokinetic model. A one-compartment disposition model was found to best describe the data for both the parent and the metabolite, and the metabolite was assumed to be formed only from the central compartment of the parent drug. Prior treatment with RIF did not alter the pharmacokinetics of RFP but appeared to increase the excretion of 25-desacetyl RFP in a nonlinear fashion. The RFP oral clearance and volume of distribution were found to increase by 0.049 liter/h and 0.691 liter, respectively, with a 1-kg increase from the median weight of 50 kg. The oral clearance of 25-desacetyl RFP was found to be 35% lower in female patients. The model developed here describes the population pharmacokinetics of RFP and its primary metabolite in tuberculosis patients and includes the effects of prior administration with RIF and covariate factors.

The use of a systemic prime/mucosal boost strategy with an equine influenza ISCOM vaccine to induce protective immunity in horses

In horses, natural infection confers long lasting protective immunity characterised by mucosal IgA and humoral IgGa and IgGb responses. In order to investigate the potential of locally administered vaccine to induce a protective IgA response, responses generated by vaccination with an immunostimulating complex (ISCOM)-based vaccine for equine influenza (EQUIP F) containing A/eq/Newmarket/77 (H7N7), A/eq/Borlänge/91 (H3N8) and A/eq/Kentucky/98 (H3N8) using a systemic prime/mucosal boost strategy were studied. Seven ponies in the vaccine group received EQUIP F vaccine intranasally 6 weeks after an initial intramuscular immunisation. Following intranasal boosting a transient increase in virus-specific IgA was detected in nasal wash secretions. Aerosol challenge with the A/eq/Newmarket/1/93 reference strain 4 weeks after the intranasal booster resulted in clinical signs of infection and viral shedding in seven of seven influenza-naive control animals whereas the seven vaccinated ponies had statistically significantly reduced clinical signs and duration of virus excretion. Furthermore, following this challenge, significantly enhanced levels of virus-specific IgA were detected in the nasal washes from vaccinated ponies compared with the unvaccinated control animals. These data indicate that the intranasal administration of EQUIP F vaccine primes the mucosal system for an enhanced IgA response following exposure to live influenza virus.

Immune responses and protective efficacy in ponies immunised with an equine influenza ISCOM vaccine containing an 'American lineage' H3N8 virus

Protective responses generated by vaccination with an immuno-stimulating complex (ISCOM)-based vaccine for equine influenza (EQUIP F), containing a new 'American lineage' H3N8 virus, were studied. Seven ponies in the vaccine group received two intramuscular injections of EQUIP F given 6 weeks apart. Aerosol challenge with an A/eq/Newmarket/1/93 reference strain 4 weeks after booster vaccination resulted in clinical signs of infection and viral shedding in 7 influenza-naive control animals whereas the vaccinated ponies were significantly protected from both clinical signs and virus excretion. Influenza virus-specific IgG responses in serum following immunisation with the ISCOM vaccine were predominantly of the IgGa and IgGb sub-isotypes, a pattern similar to that generated by equine influenza virus infection. However, in contrast to the response following infection, virus-specific antibody responses in nasal washes following immunisation were characterised by the presence of IgG but not IgA.These results demonstrated that an ISCOM-based vaccine containing A/eq/Kentucky/98 provides strong protective immunity against challenge with an 'American lineage' H3N8 reference virus.

Investigation of antibiotic and antibacterial agent cross-resistance in target bacteria from homes of antibacterial product users and nonusers

AIM

To describe the relationship between antibiotic and antibacterial resistance in environmental and clinical bacteria from home environments across geographical locations, relative to the use or nonuse of antibacterial products, with a focus on target organisms recognized as potential human pathogens.

METHODS AND RESULTS

In a randomized study, environmental and clinical samples were collected from the homes of antibacterial product users (n=30) and nonusers (n=30) for the isolation of target bacteria for antibiotic and antibacterial testing in three geographical areas (in USA and UK). Isolates were tested for antibiotic susceptibility, with selected antibiotic-resistant and antibiotic-susceptible isolates tested against four common antibacterial agents (triclosan, para-chloro-meta-xylenol, pine oil and quaternary ammonium compound). Prequalified users and nonusers at each location were randomly selected after meeting exclusionary criteria. Of 1238 isolates, more target bacteria were recovered from nonuser than user homes. Of Staphylococcus aureus isolates (n=33), none showed resistance to oxacillin or vancomycin; for Enterococcus sp. (n=149), none were resistant to ampicillin or vancomycin; and for Klebsiella pneumoniae (n=54)and Escherichia coli (n=24), none were resistant to third generation cephalosporins. Antibiotic resistance to one or more of the standard test panel drugs for Gram-positive and Gram-negative target bacteria was comparable between nonuser and user homes for both environmental and clinical isolates [e.g. resistance of environmental coagulase-negative (CN) Staphylococcus sp. was 73.8% (124/168) from nonuser homes and 73.0% (111/152) from user homes, and Enterobacteriaceae other than E. coli, 75.9% (186/245) from nonuser homes compared with 78.0% from user homes]. Of 524 Gram-negatives tested against preferred/alternative drugs, 97.1% (509/524) were susceptible to all antibiotics, across both groups. Isolates of S. aureus, Enterococcus sp. and CN Staphylococcus sp. susceptible to all preferred treatment drugs showed comparable antibacterial minimum inhibitory concentration (MIC) results between nonuser and user home isolates. For Gram-positives resistant to one or more preferred drugs, greatest resistance to antibacterial active ingredients was found in the nonuser group. For Gram-negatives, the antibacterial MIC data were comparable for isolates that were fully susceptible and resistant to one or more preferred/alternative treatment antibiotics.

CONCLUSIONS

The results showed a lack of antibiotic and antibacterial agent cross-resistance in target bacteria from the homes of antibacterial product users and nonusers, as well as increased prevalence of potential pathogens in nonuser homes.

SIGNIFICANCE AND IMPACT OF THE STUDY

It refutes widely publicized, yet unsupported, hypotheses that use of antibacterial products facilitates the development of antibiotic resistance in bacteria from the home environment.

Implementation of an Algorithm for Modeling Disulfide Bond Patterns Using Mass Spectrometry

The paper describes the implementation of a software system based on the Fenyö disulfide bond assignment algorithm. The system allows an investigator to enter data derived from mass spectrum peak assignments, a target protein sequence and other experimental conditions. The output of the system is the set of disulfide bonding pattern models that are consistent with the experimental evidence. The software and code are available through a public web site, which also has a functioning, publicly accessible version of the disulfide bond modeler. This implementation was tested as part of a project to check homology-based assignments disulfide bonding patterns of human integrins.

Potent inhibition of NFAT activation and T cell cytokine production by novel low molecular weight pyrazole compounds

NFAT (nuclear factor of activated T cell) proteins are expressed in most immune system cells and regulate the transcription of cytokine genes critical for the immune response. The activity of NFAT proteins is tightly regulated by the Ca(2+)/calmodulin-dependent protein phosphatase 2B/calcineurin (CaN). Dephosphorylation of NFAT by CaN is required for NFAT nuclear localization. Current immunosuppressive drugs such as cyclosporin A and FK506 block CaN activity thus inhibiting nuclear translocation of NFAT and consequent cytokine gene transcription. The inhibition of CaN in cells outside of the immune system may contribute to the toxicities associated with cyclosporin A therapy. In a search for safer immunosuppressive drugs, we identified a series of 3,5-bistrifluoromethyl pyrazole (BTP) derivatives that block Th1 and Th2 cytokine gene transcription. The BTP compounds block the activation-dependent nuclear localization of NFAT as determined by electrophoretic mobility shift assays. Confocal microscopy of cells expressing fluorescent-tagged NFAT confirmed that the BTP compounds block calcium-induced movement of NFAT from the cytosol to the nucleus. Inhibition of NFAT was selective because the BTP compounds did not affect the activation of NF-kappaB and AP-1 transcription factors. Treatment of intact T cells with the BTP compounds prior to calcium ionophore-induced activation of CaN caused NFAT to remain in a highly phosphorylated state. However, the BTP compounds did not directly inhibit the dephosphorylation of NFAT by CaN in vitro, nor did the drugs block the dephosphorylation of other CaN substrates including the type II regulatory subunit of protein kinase A and the transcription factor Elk-1. The data suggest that the BTP compounds cause NFAT to be maintained in the cytosol in a phosphorylated state and block the nuclear import of NFAT and, hence, NFAT-dependent cytokine gene transcription by a mechanism other than direct inhibition of CaN phosphatase activity. The novel inhibitors described herein will be useful in better defining the cellular regulation of NFAT activation and may lead to identification of new therapeutic targets for the treatment of autoimmune disease and transplant rejection.

Comparison of the effects of isoproterenol administered into the hippocampus, frontal cortex, or amygdala on behavior of rats maintained by differential reinforcement of low response rate

RATIONALE

Central administration of isoproterenol, a non-selective beta adrenergic agonist, produces behavioral changes in animal models sensitive to antidepressants. However, it is not clear which brain regions mediate these effects.

OBJECTIVES

To investigate the antidepressant-like effects of site-specific administration of isoproterenol and the involvement of beta adrenergic receptor subtypes.

METHODS

The effects of isoproterenol, which was administered into the lateral ventricle, hippocampus, frontal cortex, or amygdala, were determined in rats under a differential-reinforcement-of-low-rate (DRL) 72-s schedule. The effects of beta adrenergic antagonists on the actions of isoproterenol also were determined.

RESULTS

When injected bilaterally into the hippocampus, isoproterenol (1-30 microg/side) decreased response rate and increased reinforcement rate in a dose-dependent manner. The minimum dose of isoproterenol required for changing DRL behavior was 6 microg (i.e., 3 microg bilaterally), compared to 10 microg for intracerebroventricular and 60 microg (30 microg bilaterally) for administration into the frontal cortex or amygdala. These effects of isoproterenol were blocked by the beta adrenergic antagonist propranolol. In addition, the effects of isoproterenol injected intrahippocampally also were antagonized dose-dependently by the beta-1 selective antagonist betaxolol and the beta-2 selective antagonist ICI 118,551. The relative potency of these antagonists for blocking the effects of isoproterenol suggested predominant mediation by beta-1 adrenergic receptors.

CONCLUSIONS

The hippocampus is an important site involved in mediating the antidepressant-like effect of isoproterenol. This suggests a key, although not exclusive, role for this site in the pathophysiology of depression and its pharmacotherapy.

Age- and gender-related differences in maximum shortening velocity of skeletal muscle fibers

OBJECTIVE

To determine age- and gender-related differences in maximum unloaded shortening velocity (Vo) of Type I and IIA single muscle fibers. Muscle fibers must have a broad range of contractile velocities to generate the full range of power required for varied activities.

DESIGN

Percutaneous needle biopsies of the vastus lateralis were obtained from 31 healthy subjects (n = 7 young men [YM], n = 7 young women [YW], n = 12 older men [OM], n = 12 older women [OW]). The slack test was used to determine Vo of individual fibers; 916 muscle fibers were chemically skinned. Fiber type was determined by myosin heavy chain isoform identification.

RESULTS

Among men, Vo (fiber lengths/sec) was reduced with age in Type IIA fibers (OM vs. YM: 1.78 vs. 2.14; P < 0.05) but unchanged in Type I fibers. Among women, Vo was reduced with age in Type I fibers (OW vs. YW: 0.70 vs. 0.75; P < 0.05) but not IIA. OW had a lower Vo than did OM in both fiber types (Type I: OW = 0.70, OM = 0.77; Type IIA: OW = 1.51, OM = 1.78; P < 0.05). YW did not differ from YM.

CONCLUSIONS

Both age and gender affect Vo. Age- and gender-related differences in Vo may partially explain the impairments in muscle function that occur with aging and the greater impairment in muscle function observed in OW compared with that observed in OM.

Human visual function in the North Carolina clinical study on possible estuary-associated syndrome

The U.S. Environmental Protection Agency assisted the North Carolina Department of Health and Human Services in conducting a study to investigate the potential for an association between fish kills in the North Carolina estuary system and the risk for persistent health effects. Impetus for the study was recent evidence suggesting that estuarine dinoflagellates, including members of the toxic Pfiesteria complex (TPC), P. piscicida and P. schumwayae, may release a toxin(s) that kills fish and adversely affects human health. This report describes one component of the study in which visual system function was assessed. Participants working primarily in estuaries inhabited by TPC or in off-shore waters thought not to contain TPC were studied. The potentially exposed estuary (n = 22) and unexposed offshore (n = 20) workers were matched for age, gender, and education. Visual acuity did not differ significantly between the cohorts, but visual contrast sensitivity (VCS), an indicator of visual pattern-detection ability for stimuli of various sizes, was significantly reduced by about 30% in the estuary relative to the offshore cohort. A further analysis that excluded participants having a history possibly predictive of neuropsychological impairment showed a similar VCS reduction. Additional analyses indicated that differences between the cohorts in age, education, smoking, alcohol consumption, and total time spent on any water did not account for the difference in VCS. Exploratory analyses suggested a possible association between the magnitude of VCS reduction and hours spent in contact with a fish kill. The profile of VCS deficit across stimulus sizes resembled that seen in organic solvent-exposed workers, but an assessment of occupational solvent, and other neurotoxicant, exposures did not indicate differences between the cohorts. These results suggest that factor(s) associated with the North Carolina estuaries, including the possibility of exposure to TPC toxin(s), may impair visual system function.

Estuary-associated syndrome in North Carolina: an occupational prevalence study

Atlantic coast estuaries recently have experienced fish kills and fish with lesions attributed to Pfiesteria piscicida and related dinoflagellates. Human health effects have been reported from laboratory exposure and from a 1997 Maryland fish kill. North Carolina has recorded Pfiesteria-related fish kill events over the past decade, but human health effects from environmental exposure have not been systematically investigated or documented here. At the request of the state health agency, comprehensive examinations were conducted in a cross-sectional prevalence study of watermen working where Pfiesteria exposure may occur: waters where diseased or stressed fish were reported from June to September 1997, and where Pfiesteria had been identified in the past. Controls worked on unaffected waterways. The study was conducted 3 months after the last documented Pfiesteria-related fish kill. The goal was to document any persistent health effects from recent or remote contact with fish kills, fish with lesions, or affected waterways, using the 1997 U.S. Centers for Disease Control and Prevention case description for estuary-associated syndrome (EAS). Examinations included comprehensive medical, occupational, and environmental history, general medical, dermatologic, and neurologic examinations, vision testing, and neuropsychologic evaluations. Seventeen of 22 watermen working in affected waters and 11 of 21 in unaffected waters reported exposure to a fish kill or to fish with lesions. We found no pattern of abnormalities on medical, neurologic, neuropsychologic, or NES-2 evaluation. By history, one subject in each group met the EAS criteria, neither of whom had significant neuropsychological impairment when examined. Watermen from affected waterways had a significant reduction in visual contrast sensitivity (VCS) at the midspatial frequencies, but we did not identify a specific factor or exposure associated with this reduction. The cohorts did not differ in reported occupational exposure to solvents (qualitative) or to other neurotoxicants; however, exposure history was not sufficiently detailed to measure or control for solvent exposure. This small prevalence study in watermen, conducted 3 months after the last documented fish kill related to Pfiesteria, did not identify an increased risk of estuary-associated syndrome in those working on affected waterways. A significant difference between the estuary and ocean watermen was found on VCS, which could not be attributed to any specific factor or exposure. VCS may be affected by chemicals, drugs, alcohol, and several developmental and degenerative conditions; it has not been validated as being affected by known exposure to dinoflagellate secretions. VCS should be considered for inclusion in further studies, together with documentation or quantification of its potential confounders, to assess whether it has utility in relationship to dinoflagellate exposure.

An MRI study of temporal lobe structures in men with bipolar disorder or schizophrenia

BACKGROUND

Hippocampal atrophy has been described in postmortem and magnetic resonance imaging studies of schizophrenia. The specificity of this finding to schizophrenia remains to be determined. The neuropathology of bipolar disorder is understudied, and temporal lobe structures have only recently been evaluated.

METHODS

Twenty-four bipolar, 20 schizophrenic, and 18 normal comparison subjects were evaluated using magnetic resonance brain imaging. Image data were acquired using a three-dimensional spoiled GRASS sequence, and brain images were reformatted in three planes. Temporal lobe structures including the amygdala, hippocampus, parahippocampus, and total temporal lobe were measured to obtain volumes for each structure in the three subject groups. Severity of symptoms in both patient groups was assessed at the time the magnetic resonance images were obtained.

RESULTS

Hippocampal volumes were significantly smaller in the schizophrenic group than in both bipolar and normal comparison subjects. Further, amygdala volumes were significantly larger in the bipolar group than in both schizophrenic and normal comparison subjects.

CONCLUSIONS

The results suggest differences in affected limbic structures in patients with schizophrenia and bipolar disorder. These specific neuroanatomic abnormalities may shed light on the underlying pathophysiology and presentation of the two disorders.

Effects of morphine and tramadol on somatic and visceral sensory function and gastrointestinal motility after abdominal surgery

BACKGROUND

Chronic nociceptive input induces sensitization and changes in regulatory reflexes in animal models. In humans, postoperative somatic and visceral sensitization and the secondary effects on reflex gut motility are unclear.

METHODS

Somatic and visceral sensation and gastrointestinal motility were evaluated after abdominal hysterectomies in 50 patients who were randomized to receive double-blinded postoperative 48-h infusions of morphine or tramadol. Pain scores, rectal distension, skin electric sensation and pain tolerance thresholds, and gastrointestinal transit were assessed before and after operation, during and after analgesic infusions.

RESULTS

Pain intensity scores decreased similarly with morphine and tramadol infusions (total doses, 66.8+/-20 mg and 732.4+/-152 mg [mean +/- SD], respectively). Skin pain tolerance thresholds in the incisional dermatome remained similar with morphine and tramadol throughout the study. During morphine infusions, pain tolerance thresholds on the shoulder increased (P<0.05) and then decreased after discontinuation on day 4 (P<0.02) compared with before operation. Rectal distension pain tolerance pressure thresholds increased after operation during morphine infusions (P<0.05). Similar but nonsignificant trends occurred with tramadol. Orocecal and colonic transit times increased after operation with both morphine and tramadol (P<0.005), but gastric emptying was prolonged only with morphine (P = 0.03). AU motility and sensory parameters had returned to preoperative levels by 1 month after operation.

CONCLUSIONS

Pain control was equally effective with morphine and tramadol infusions. No somatic or visceral sensitization was evident during morphine and tramadol infusions, but pain tolerance thresholds as markers of antinociception were increased more during morphine infusions. The significant sensitization seen only after morphine discontinuation may be due to convergent visceral input. Gut motility was prolonged significantly by visceral surgery itself and also by morphine.

Elevated lipid levels in Vietnam veterans with chronic posttraumatic stress disorder

BACKGROUND

Elevated cholesterol levels have been reported in panic disorder and anger attacks, but not major depression. No data have been reported in posttraumatic stress disorder (PTSD).

METHODS

Seventy-three male Vietnam veterans with chronic (PTSD) had serum lipid screening upon entry to a 90-day inpatient program.

RESULTS

Elevated cholesterol, low-density lipoprotein, triglycerides, and reduced high-density lipoprotein, were frequent in Vietnam veterans with chronic PTSD and are significant risk factors for coronary artery disease.

CONCLUSIONS

Routine lipid screening may be warranted in this at-risk population. Altered lipid levels may result from activation of the noradrenergic system.

Lack of correlation of symptoms with specialist-assessed long-term asthma severity

STUDY OBJECTIVES

To validate three indicators of asthma severity as defined in the National Asthma Education Program (NAEP) guidelines (ie, frequency of symptoms, degree of airflow obstruction, and frequency of use of oral glucocorticoids), alone and in combination, against severity as assessed by pulmonary specialists provided with 24-month medical chart data.

DESIGN

Cross-sectional comparison of questionnaire and clinical-based markers of asthma severity with physician-assessed severity based on chart review. The pulmonologists did not have access to the results of the baseline evaluations when making their severity assessments.

SETTING AND PARTICIPANTS

Study participants were 193 asthmatic members (age range, 6 to 55 years) of a large health maintenance organization who underwent a baseline evaluation as part of a separate longitudinal study. This evaluation consisted of spirometry, skin prick testing, and a survey that included questions on symptoms and medication use. The participants in the ancillary study were selected, based on their baseline evaluation, to reflect a broad range of asthma severity.

RESULTS

Based on the chart review, 86 of the study subjects (45%) had mild disease, 90 (45%) had moderate disease, and 17 (9%) had severe disease. This physician-assessed severity correlated highly (p < or = 0.013) with NAEP-based indices of severity based on oral glucocorticoid use (never, infrequently for attacks, frequently for attacks, and daily use) and on spirometry (FEV1 > 80% predicted, 60 to 80% predicted, and <60% predicted). It did not, however, correlate with current asthma symptoms (< or = once/week, 2 to 6 times/week, daily) (p=0.87). A composite severity score based on spirometry and the glucocorticoid use data still provided an overall agreement of 63%, with a weighted kappa of 0.40.

CONCLUSIONS

While current symptoms are the most important concern of patients with asthma, they reflect the current level of asthma control more than underlying disease severity. Investigators must therefore use caution when comparing groups of patients for whom severity categorization is based largely on symptomatology. This observation, that symptoms alone do not reflect disease severity, becomes even more important as health-care delivery moves closer to protocols/practice guidelines and "best treatment" programs that rely heavily on symptoms to guide subsequent treatment decisions.

HIV-infected subjects with the E4 allele for APOE have excess dementia and peripheral neuropathy

HIV produces a chronic viral infection of the central nervous system that elicits chronic glial activation and overexpression of glial cytokines that are also implicated in Alzheimer disease (AD) pathogenesis. A genetic risk factor for AD is the E4 isoform for apolipoprotein E (APOE). Here we compare the frequency of neurologic symptoms for subjects with and without the E4 isoform (E4(+)and E4(-), respectively) in an HIV cohort. Compared with E4(-) subjects, twice as many E4(+) subjects were demented (30% compared with 15%) or had peripheral neuropathy (70% compared with 39%) at least once, and they had threefold more symptomatic examinations (13% compared with 3% and 42% compared with 14%, respectively)(P < 0.0001). Thus, neurologic symptoms for HIV-infection and AD are linked through an etiologic risk factor. Long-term survivors of HIV infection with E4 may be at high risk for AD; conversely, gene-viral interactions may speed AD pathogenesis.

LeFort I orbitotomy: a new approach to the inferonasal orbital apex

Numerous approaches to the orbit have been elegantly described in the literature. One area of the orbit that remains difficult to approach with standard techniques is the inferonasal apex. We describe a new surgical procedure we have termed the LeFort I orbitotomy. The technique involves creation of a LeFort I osteotomy to separate the maxilla from the zygoma and nose bilaterally. The posterior inferomedial orbital bone is then removed and the periorbita opened. This approach allows a more direct, less tangential view to this area of the orbit than does a Caldwell-Luc approach. Wider access for tumor manipulation is gained than would be possible with a transnasal endoscopic approach. An illustrative case report is presented.

Cognitive impairment in euthymic bipolar patients with and without prior alcohol dependence. A preliminary study

BACKGROUND

Few studies of the neurocognitive performance of patients with bipolar disorder have been performed while patients are in the euthymic state.

METHODS

Twenty-five euthymic bipolar patients (12 with and 13 without a history of alcohol dependence) were compared with 22 normal control subjects on a neuropsychological test battery assessing a range of cognitive domains. The relationship between subjects' neurocognitive performance and the course-of-illness variables (lifetime episodes and duration of mania, depression, or both), as well as current lithium level, was determined.

RESULTS

The results indicated differences across the groups, with the bipolar patients with and without alcohol dependence performing more poorly than controls on tests of verbal memory. Furthermore, bipolar subjects with a history of alcohol dependence had additional decrements in executive (i.e., frontal lobe) functions when compared with controls. For subjects in the bipolar group, lifetime months of mania and depression were negatively correlated with performance in verbal memory and several executive function measures.

CONCLUSIONS

Our findings support the presence of persistent neurocognitive difficulties in patients with long-standing bipolar disorder who are not in the psychiatrically acute state or who are suffering the effects of alcohol abuse and suggest that there may be an aggregate negative effect of lifetime duration of bipolar illness on memory and frontal or executive systems.

Grief support programs: patients' use of services following the loss of a desired pregnancy and degree of implementation in academic centers

Limited information is available concerning what resources to offer and how to best counsel patients after the loss of a desired pregnancy. The Touching Hearts Program at the University of Iowa offers support for such patients and their families. We reviewed responses to a questionnaire (n=128) sent to families who received support from the program. Data was evaluated using descriptive statistics or Pearson's Chi-square. A p value of <0.05 was considered statistically significant. Sixty-four percent of patients reported visiting with the chaplain, 67% had their baby blessed or baptized, and 80% held a funeral or memorial service. Ninety-two percent of patients were offered private time with their baby, and 87% elected to do so. While 66% of patients felt they had adequate time with their child, 85% indicated they would have appreciated additional opportunities to see their baby. Resources offered by the Touching Hearts Program were highly utilized by patients. Changes in health care may decrease funding for such programs, however, high patient utilization indicates a need for grief support programs at facilities involved in management of abnormal pregnancies. A survey of academic centers showed that the vast majority offer similar programs to their patients.

Epidemiology and aetiological diagnosis of corneal ulceration in Madurai, south India

AIMS/BACKGROUND

To determine the epidemiological characteristics and risk factors predisposing to corneal ulceration in Madurai, south India, and to identify the specific pathogenic organisms responsible for infection.

METHODS

All patients with suspected infectious central corneal ulceration presenting to the ocular microbiology and cornea service at Aravind Eye Hospital, Madurai, from 1 January to 31 March 1994 were evaluated. Sociodemographic data and information pertaining to risk factors were recorded, all patients were examined, and corneal cultures and scrapings were performed.

RESULTS

In the 3 month period 434 patients with central corneal ulceration were evaluated. A history of previous corneal injury was present in 284 patients (65.4%). Cornea cultures were positive in 297 patients (68.4%). Of those individuals with positive cultures 140 (47.1%) had pure bacterial infections, 139 (46.8%) had pure fungal infections, 15 (5.1%) had mixed bacteria and fungi, and three (1.0%) grew pure cultures of Acanthamoeba. The most common bacterial pathogen isolated was Streptococcus pneumoniae, representing 44.3% of all positive bacterial cultures, followed by Pseudomonas spp (14.4%). The most common fungal pathogen isolated was Fusarium spp, representing 47.1% of all positive fungal cultures, followed by Aspergillus spp (16.1%).

CONCLUSIONS

Central corneal ulceration is a common problem in south India and most often occurs after a superficial corneal injury with organic material. Bacterial and fungal infections occur in equal numbers with Streptococcus pneumoniae accounting for the majority of bacterial ulcers and Fusarium spp responsible for most of the fungal infections. These findings have important public health implications for the treatment and prevention of corneal ulceration in the developing world.

Expression of N-acetyl-D-galactosamine associated epitope in synovium: a potential marker of glycoprotein production

OBJECTIVE

To investigate synovial glycoprotein production in situ, a novel monoclonal antibody (Mab), A13D8, was used to evaluate the expression of an epitope containing N-acetyl-D-galactosamine (GalNAc) in normal and pathological synovium.

METHODS

Immunohistological and cytochemical analysis of synovial tissue samples was undertaken with single and double staining techniques using the A13D8 Mab, anti-CD68, vascular cell adhesion molecule-1 (VCAM-1), the hyaluronan associated enzyme uridine diphosphoglucose dehydrogenase (UDPGD), and the anti-Golgi Mab SSN/HR-1992. The specificity of the A13D8 Mab was established through blocking studies using carbohydrate residues, including GalNAc and N-acetylglucosamine (GlcNAc).

RESULTS

A13D8 is expressed intensely in the cytoplasm of normal type B lining cells, which coexpress VCAM-1 and UDPGD, and is not expressed by CD68+ type A lining cells. In the lining layer of RA synovium, there is a negative correlation between A13D8 expression and the level of lymphocytic infiltration in the sublining areas (r = -0.43, p < 0.001). The endothelium of a subset of venules, typically in lymphocyte-rich aggregates, also stains intensely for A13D8. Pretreatment of the Mab with GalNAc completely eliminates the tissue staining, as well as the 110 kDa band seen on immunoblot, whereas pretreatment of A13D8 with GlcNAc and lactose has no effect. Double staining of HEp-2 cells with A13D8 and the anti-Golgi Mab SSN/HR-1992 reveals co-localization of the A13D8 epitope to the Golgi apparatus.

CONCLUSION

Type B synovial lining cells and selected synovial endothelium express GalNAc containing epitope identified by Mab A13D8. Marked reduction in the expression of this epitope in the lining layer of inflamed RA synovium suggests that the synovial production of GalNAc containing glycoproteins, such as mucins, may be altered in this disorder.