A Phase 1a Study to Evaluate Safety, Tolerability, Pharmacokinetics, and Pharmacodynamics of RO7303509, an Anti-TGFβ3 Antibody, in Healthy Volunteers

INTRODUCTION

Transforming growth factor beta (TGFβ) cytokines (TGFβ1, TGFβ2, and TGFβ3) play critical roles in tissue fibrosis. However, treatment with systemic pan-TGFβ inhibitors have demonstrated unacceptable toxicities. In this study, we evaluated the safety, tolerability, pharmacokinetics, and pharmacodynamics of RO7303509, a high-affinity, TGFβ3-specific, humanized immunoglobulin G1 monoclonal antibody, in healthy adult volunteers (HVs).

METHODS

This phase 1a, randomized, double-blind trial included six cohorts for evaluation, with each cohort receiving single doses of placebo or RO7303509, administered intravenously (IV; 50 mg, 150 mg, 240 mg) or subcutaneously (SC; 240 mg, 675 mg, 1200 mg). The frequency and severity of adverse events (AEs) and RO7303509 serum concentrations were monitored throughout the study. We also measured serum periostin and cartilage oligomeric matrix protein (COMP) by immunoassay and developed a population pharmacokinetics model to characterize RO7303509 serum concentrations.

RESULTS

The study enrolled 49 HVs, with a median age of 39 (range 18-73) years. Ten (27.8%) RO7303509-treated subjects reported 24 AEs, and six (30.8%) placebo-treated subjects reported six AEs. The most frequent AEs related to the study drug were injection site reactions and infusion-related reactions. Maximum serum concentrations (Cmax) and area under the concentration-time curve from time 0 to infinity (AUC0-inf) values for RO7303509 appeared to increase dose-proportionally across all doses tested. Serum concentrations across cohorts were best characterized by a two-compartment model plus a depot compartment with first-order SC absorption kinetics. No subjects tested positive for anti-drug antibodies (ADAs) at baseline; one subject (2.8%; 50 mg IV) tested positive for ADAs at a single time point (day 15). No clear pharmacodynamic effects were observed for periostin or COMP upon TGFβ3 inhibition.

CONCLUSION

RO7303509 was well tolerated at single SC doses up to 1200 mg in HVs with favorable pharmacokinetic data that appeared to increase dose-proportionally. TGFβ3-specific inhibition may be suitable for development as a chronic antifibrotic therapy.

TRIAL REGISTRATION

ISRCTN13175485.

Comparative Pharmacokinetics and Safety Assessment of 1st- and 2nd-Generation Zinpentraxin Alfa Drug Products in Healthy Volunteers: A Randomized Crossover Study

Zinpentraxin alfa is a recombinant form of the human pentraxin-2 that was studied in idiopathic pulmonary fibrosis (IPF). To improve the purity and yield of the drug material, a 2nd-generation drug product was developed. To characterize and compare the pharmacokinetic (PK) properties of the 1st- and 2nd-generation zinpentraxin alfa, PK studies were conducted in healthy volunteers (HVs). In a phase 1 randomized, double-blind, 2-sequence crossover, sequential 2-stage study (ISRCTN59409907), single intravenous (IV) doses of 1st- and 2nd-generation zinpentraxin alfa at 10 mg/kg were studied with a blinded interim analysis (IA) at the end of stage 1. Bioequivalence (BE) was achieved for the maximum observed plasma concentration (Cmax), but the overall exposure was higher for the 2nd- compared to the 1st-generation zinpentraxin alfa. The study was stopped after stage 1 as the gating criteria were met based on the result of the blinded IA. Safety profiles were similar for the 1st- and 2nd-generation drug products, and antidrug antibody (ADA) was not observed in this study.

Applications of Advanced Natural Language Processing for Clinical Pharmacology

Natural language processing (NLP) is a branch of artificial intelligence, which combines computational linguistics, machine learning, and deep learning models to process human language. Although there is a surge in NLP usage across various industries in recent years, NLP has not been widely evaluated and utilized to support drug development. To demonstrate how advanced NLP can expedite the extraction and analyses of information to help address clinical pharmacology questions, inform clinical trial designs, and support drug development, three use cases are described in this article: (1) dose optimization strategy in oncology, (2) common covariates on pharmacokinetic (PK) parameters in oncology, and (3) physiologically-based PK (PBPK) analyses for regulatory review and product label. The NLP workflow includes (1) preparation of source files, (2) NLP model building, and (3) automation of data extraction. The Clinical Pharmacology and Biopharmaceutics Summary Basis of Approval (SBA) documents, US package inserts (USPI), and approval letters from the US Food and Drug Administration (FDA) were used as our source data. As demonstrated in the three example use cases, advanced NLP can expedite the extraction and analyses of large amounts of information from regulatory review documents to help address important clinical pharmacology questions. Although this has not been adopted widely, integrating advanced NLP into the clinical pharmacology workflow can increase efficiency in extracting impactful information to advance drug development.

Modeling Alzheimer's disease progression utilizing clinical trial and ADNI data to predict longitudinal trajectory of CDR-SB

There is strong interest in developing predictive models to better understand individual heterogeneity and disease progression in Alzheimer's disease (AD). We have built upon previous longitudinal AD progression models, using a nonlinear, mixed-effect modeling approach to predict Clinical Dementia Rating Scale - Sum of Boxes (CDR-SB) progression. Data from the Alzheimer's Disease Neuroimaging Initiative (observational study) and placebo arms from four interventional trials (N = 1093) were used for model building. The placebo arms from two additional interventional trials (N = 805) were used for external model validation. In this modeling framework, CDR-SB progression over the disease trajectory timescale was obtained for each participant by estimating disease onset time (DOT). Disease progression following DOT was described by both global progression rate (RATE) and individual progression rate (α). Baseline Mini-Mental State Examination and CDR-SB scores described the interindividual variabilities in DOT and α well. This model successfully predicted outcomes in the external validation datasets, supporting its suitability for prospective prediction and use in design of future trials. By predicting individual participants' disease progression trajectories using baseline characteristics and comparing these against the observed responses to new agents, the model can help assess treatment effects and support decision making for future trials.

Idiopathic pulmonary fibrosis therapy development: a clinical pharmacology perspective

Drug development for idiopathic pulmonary fibrosis (IPF) has been challenging due to poorly understood disease etiology, unpredictable disease progression, highly heterogeneous patient populations, and a lack of robust pharmacodynamic biomarkers. Moreover, because lung biopsy is invasive and dangerous, making the extent of fibrosis as a direct longitudinal measurement of IPF disease progression unfeasible, most clinical trials studying IPF can only assess progression of fibrosis indirectly through surrogate measures. This review discusses current state-of-art practices, identifies knowledge gaps, and brainstorms development opportunities for preclinical to clinical translation, clinical populations, pharmacodynamic endpoints, and dose optimization strategies. This article highlights clinical pharmacology perspectives in leveraging real-world data as well as modeling and simulation, special population considerations, and patient-centric approaches for designing future studies.

Extension of the Alternative IV Dosing Regimens of Atezolizumab into Combination Settings through Modeling and Simulation

Atezolizumab is approved as an intravenous infusion for use as a single agent and in combination with other therapies in a number of indications.1 The objectives of this publication are to characterize atezolizumab pharmacokinetics (PK) across indications with available clinical data from one Phase I and eight Phase III studies, to determine the exposure-response (ER) relationships in the combination settings across a variety of tumor types, and to provide the clinical safety to support the extension of the 840 mg q2w, 1200 mg q3w, and 1680 mg q4w IV dosing regimens across various indications in the combination settings. Across all clinical studies, atezolizumab PK remained in the dose linear range and were similar across tumor types when used in combination therapy or as a monotherapy. In the combination studies, efficacy was independent of exposures tested and there was no significant increase in adverse events with increasing atezolizumab exposure (flat ER). The safety profile of atezolizumab in the individual combination studies was generally consistent with the established safety profile of atezolizumab, the combination partners, and the disease under study. The similar atezolizumab PK across monotherapy and combination therapy setting as well as the flat ER in new tumor types and combination therapies support the use of the three atezolizumab dosing regimens to be used interchangeably in the combination setting. Atezolizumab is now approved with three interchangeable dosing regimens of 840 mg q2w, 1200 mg q3w, and 1680 mg q4w for single-agent and combination therapy use in the US and EU. This article is protected by copyright. All rights reserved.

Pharmacometric analyses of alectinib to facilitate approval of the optimal dose for the first-line treatment of anaplastic lymphoma kinase-positive non-small cell lung cancer

Alectinib is an anaplastic lymphoma kinase (ALK) inhibitor approved for treatment of ALK‐positive non‐small cell lung cancer. Population pharmacokinetic (PK) models were developed for alectinib and its major active metabolite M4 using phase I/II PK data in crizotinib‐failed patients (N = 138). The PK profiles were best described by two separate models with similar structure for both entities: open one‐compartment models with sequential zero/first‐order input and first‐order elimination rate. Body weight with fixed allometric scaling factor on clearance and volume of both entities was the only significant covariate. Bayesian feedback analyses of the PK data collected from Japanese and global treatment‐naïve patients in phase III studies (N = 334) confirmed the body weight effect. Landmark Cox proportional hazards analyses of progression‐free survival in treatment‐naïve patients identified the average molar concentrations of both entities alectinib and M4 during the first 6 weeks of treatment as a significant covariate, with an optimal response achieved for concentrations above 1040 nmol/L. With 600 mg twice daily (b.i.d.), 92% of global patients are above this threshold concentration, compared with only 43% of patients with 300 mg b.i.d. In Japan, where the body weight distribution is lower, the approved 300 mg b.i.d. dose brings about 70% of Japanese patients above this threshold. Logistic regression analyses found no significant relationship between the combined alectinib–M4 molar concentration and first occurrence of adverse events. These pharmacometric results were used to expedite and facilitate regulatory approvals of 600 mg b.i.d. for first‐line ALK‐positive NSCLC in the United States and European Union in 2017 and in China in 2018.

Subcutaneous dosing regimens of tocilizumab in children with systemic or polyarticular juvenile idiopathic arthritis

Objectives

To determine s.c. tocilizumab (s.c.-TCZ) dosing regimens for systemic JIA (sJIA) and polyarticular JIA (pJIA).

Methods

In two 52-week phase 1 b trials, s.c.-TCZ (162 mg/dose) was administered to sJIA patients every week or every 2 weeks (every 10 days before interim analysis) and to pJIA patients every 2 weeks or every 3 weeks with body weight ≥30 kg or <30 kg, respectively. Primary end points were pharmacokinetics, pharmacodynamics and safety; efficacy was exploratory. Comparisons were made to data from phase 3 trials with i.v. tocilizumab (i.v.-TCZ) in sJIA and pJIA.

Results

Study participants were 51 sJIA patients and 52 pJIA patients aged 1–17 years who received s.c.-TCZ. Steady-state minimum TCZ concentration (C_trough) >5th percentile of that achieved with i.v.-TCZ was achieved by 49 (96%) sJIA and 52 (100%) pJIA patients. In both populations, pharmacodynamic markers of disease were similar between body weight groups. Improvements in Juvenile Arthritis DAS-71 were comparable between s.c.-TCZ and i.v.-TCZ. By week 52, 53% of sJIA patients and 31% of pJIA patients achieved clinical remission on treatment. Safety was consistent with that of i.v.-TCZ except for injection site reactions, reported by 41.2% and 28.8% of sJIA and pJIA patients, respectively. Infections were reported in 78.4% and 69.2% of patients, respectively. Two sJIA patients died; both deaths were considered to be related to TCZ.

Conclusion

s.c.-TCZ provides exposure and risk/benefit profiles similar to those of i.v.-TCZ. S.c. administration provides an alternative administration route that is more convenient for patients and caregivers and that has potential for in-home use.

Trial registration

ClinicalTrials.gov, http://clinicaltrials.gov, NCT01904292 and NCT01904279

Personalized Cancer Vaccines: Clinical Landscape, Challenges, and Opportunities

Tremendous innovation is underway among a rapidly expanding repertoire of promising personalized immune-based treatments. Therapeutic cancer vaccines (TCVs) are attractive systemic immunotherapies that activate and expand antigen-specific CD8⁺ and CD4⁺ T cells to enhance anti-tumor immunity. Our review highlights key issues impacting TCVs in clinical practice and reports on progress in development. We review the mechanism of action, immune-monitoring, dosing strategies, combinations, obstacles, and regulation of cancer vaccines. Most trials of personalized TCVs are ongoing and represent diverse platforms with predominantly early investigations of mRNA, DNA, or peptide-based targeting strategies against neoantigens in solid tumors, with many in combination immunotherapies. Multiple delivery systems, routes of administration, and dosing strategies are used. Intravenous or intramuscular administration is common, including delivery by lipid nanoparticles. Absorption and biodistribution impact antigen uptake, expression, and presentation, affecting the strength, speed, and duration of immune response. The emerging trials illustrate the complexity of developing this class of innovative immunotherapies. Methodical testing of the multiple potential factors influencing immune responses, as well as refined quantitative methodologies to facilitate optimal dosing strategies, could help resolve uncertainty of therapeutic approaches. To increase the likelihood of success in bringing these medicines to patients, several unique development challenges must be overcome.

Alectinib exposure-response (ER) in ALK-inhibitor naïve ALK-positive NSCLC patients: Pooled analysis across phase III studies

e20575

Background: Alectinib superiority to crizotinib has been demonstrated in ALK-inhibitor naïve ALK-positive NSCLC patients (pts) in Phase III studies conducted in Japanese (J-ALEX; JapicCTI-132316) pts receiving alectinib 300 mg BID and global (ALEX; NCT02075840) and Asian (ALESIA; NCT02838420) pts receiving alectinib 600mg BID. ER analyses are undertaken to confirm the appropriate alectinib dosing regimen for the global population. Methods: A previous population PK analysis (Hsu et al, ASCO 2016) assessed PK of alectinib and major metabolite, M4, to identify factors influencing PK variability. ER analyses across the 3 Phase III studies investigated the relationship between alectinib and progression-free survival (PFS) by a Cox proportional hazards (CPH) analysis. PK simulations for alectinib 300 mg and 600 mg BID doses were conducted to determine the proportion of pts falling above and below an identified optimal PK threshold for PFS. ER for key safety events were investigated for alectinib 600 mg BID using logistic regression. Results: Alectinib PK is influenced only by body weight and not by race/ethnicity. CPH analysis demonstrated a statistically significant relationship between alectinib exposure and PFS across the 3 Phase III studies, with an improved PFS above an identified optimal PK threshold (Table). PK simulations indicate 49% and 7% of global alectinib treated patients would fall below the optimal PK threshold for 300 and 600mg BID, respectively. Alectinib 600mg BID ensures a distribution of exposures that maximize the PFS benefit while lower alectinib doses/exposures could result in reduced efficacy. Baseline tumor size (BSIZ) was shown to negatively impact PFS with larger BSIZ seen in global pts. No significant exposure-safety relationships were identified for alectinib 600mg BID. Conclusions: Alectinib 600mg BID is the most appropriate dose in the global ALK-inhibitor naïve population. Clinical trial information: NCT02075840; JapicCTI-132316; NCT02838420. [Table: see text]

Exposure-response analysis of alectinib in crizotinib-resistant ALK-positive non-small cell lung cancer

PURPOSE

Alectinib is a selective and potent anaplastic lymphoma kinase (ALK) inhibitor that is active in the central nervous system (CNS). Alectinib demonstrated robust efficacy in a pooled analysis of two single-arm, open-label phase II studies (NP28673, NCT01801111; NP28761, NCT01871805) in crizotinib-resistant ALK-positive non-small-cell lung cancer (NSCLC): median overall survival (OS) 29.1 months (95% confidence interval [CI]: 21.3-39.0) for alectinib 600 mg twice daily (BID). We investigated exposure-response relationships from final pooled phase II OS and safety data to assess alectinib dose selection.

METHODS

A semi-parametric Cox proportional hazards model analyzed relationships between individual median observed steady-state trough concentrations (Ctrough,ss) for combined exposure of alectinib and its major metabolite (M4), baseline covariates (demographics and disease characteristics) and OS. Univariate logistic regression analysis analyzed relationships between Ctrough,ss and incidence of adverse events (AEs: serious and Grade ≥ 3).

RESULTS

Overall, 92% of patients (n = 207/225) had Ctrough,ss data and were included in the analysis. No statistically significant relationship was found between Ctrough,ss and OS following alectinib treatment. The only baseline covariates that statistically influenced OS were baseline tumor size and prior crizotinib treatment duration. Larger baseline tumor size and shorter prior crizotinib treatment were both associated with shorter OS. Logistic regression confirmed no significant relationship between Ctrough,ss and AEs.

CONCLUSION

Alectinib 600 mg BID provides systemic exposures at plateau of response for OS while maintaining a well-tolerated safety profile. This analysis confirms alectinib 600 mg BID as the recommended global dose for patients with crizotinib-resistant ALK-positive NSCLC.

Population pharmacokinetics (popPK) and exposure-response (ER) analyses bridge J-ALEX to the global population with an alectinib (ALC) 600mg bid dosing regimen

e20616

Background: J-ALEX showed superiority of ALC 300mg BID vs crizotinib (CRIZ) in Japanese ALK inhibitor naïve ALK-positive NSCLC patients (pts). PopPK and ER analyses were used to bridge J-ALEX data to the global population to confirm the appropriateness of ALC 600mg BID dose, used in global trials. Methods: The previous popPK analysis (Hsu et al, ASCO 2016) was updated to include PK data from J-ALEX and the ongoing global ALEX study to confirm any significant covariates influencing PK of ALC and major metabolite, M4, using Bayesian feedback analysis. ER analyses from J-ALEX (n=96) investigated the relationship between ALC and progression-free survival (PFS) by a Cox proportional hazards (CPH) analysis and key safety events using logistic regression. Results: The popPK models previously developed for pts who have progressed on, or are intolerant to CRIZ were able to adequately predict ALC and M4 PK in J-ALEX and ALEX. Body weight remained the only significant covariate influencing ALC and M4 PK. Administration of ALC 600mg BID in the global population ensures that ALC and M4 exposures across the body weight range are not inferior to those seen in Japanese pts receiving ALC 300mg BID, while lower doses would result in lower exposures. CPH analysis demonstrated a statistically significant relationship between ALC exposure and PFS in J-ALEX such that one third of pts in J-ALEX may benefit from a higher exposure of ALC (Table). ALC 600mg BID ensures the distribution of achieved exposures maximize the expected PFS benefit while lower ALC exposures could result in reduced efficacy. No significant exposure-safety relationships were identified in J-ALEX consistent with previous analyses conducted following ALC 600mg BID. Conclusions: ALC 600mg BID is the appropriate dose in the global ALK inhibitor naïve population. Clinical trial information: JapicCTI-132316. [Table: see text]

Pharmacokinetic and Pharmacodynamic Analysis of Subcutaneous Tocilizumab in Patients With Rheumatoid Arthritis From 2 Randomized, Controlled Trials: SUMMACTA and BREVACTA

Tocilizumab is a humanized anti-interleukin-6 receptor antibody for treating rheumatoid arthritis. Pharmacokinetic/pharmacodynamic analysis was performed on the 24-week double-blind parts of 2 randomized, controlled trials: SUMMACTA and BREVACTA. SUMMACTA compared subcutaneous tocilizumab 162 mg every week to intravenous tocilizumab 8 mg/kg every 4 weeks, whereas BREVACTA evaluated 162 mg subcutaneous tocilizumab every 2 weeks versus placebo. In addition to noncompartmental analysis, a 2-compartment population pharmacokinetic model, with first-order absorption (for subcutaneous) and linear and Michaelis-Menten elimination was used. Mean observed steady-state predose tocilizumab concentrations in week 24 were 40 and 7.4 μg/mL for subcutaneous every-week and every-2-week dosing, respectively, and 18 μg/mL for intravenous dosing. In the population PK model, body weight was an important covariate affecting clearance and volume of distribution. Mean ± SD population-predicted predose concentration for patients ≥100 kg was 23.0 ± 13.5 μg/mL for subcutaneous tocilizumab every week and 1.0 ± 1.6 μg/mL for every 2 weeks. Efficacy was lowest with subcutaneous every-2-week dosing in patients > 100 kg, reflecting lower exposure. The subcutaneous every-2-week regimen is not recommended for these patients. Pharmacodynamic responses were comparable for the every-week subcutaneous and every-4-week intravenous regimens and less pronounced with the every-2-week subcutaneous regimen. No trend was observed for increased adverse events with increasing tocilizumab exposure. The results of this analysis are consistent with the noninferiority of efficacy of the every-week subcutaneous regimen to the every-4-week intravenous regimen and the superiority of the every-2-week subcutaneous regimen to placebo. These results support the label recommendations for subcutaneous dosing of tocilizumab in rheumatoid arthritis patients.

Risk-benefit assessment of oral phosphodiesterase type 5 inhibitors for treatment of erectile dysfunction: a multiple criteria decision analysis

BACKGROUND

Erectile dysfunction (ED) is a common male sexual disorder worldwide. Three oral phosphodiesterase type 5 inhibitors (PDE5Is) - sildenafil, tadalafil and vardenafil - are available for treatment of ED. This study quantitatively evaluated the therapeutic efficacy and safety of these medications to assist treatment decision making.

METHODS

We used multiple criteria decision analysis (MCDA) to assess the totality of risk-benefit of PDE5Is. We created two models: (i) the overall model included 'overall improvement in erections' and 'any adverse events' and (ii) the detailed model included 'erectile function domain', 'ability for sexual intercourse', 'duration of erection last', 'serious adverse events', 'headache', 'flushing' and 'dyspepsia'. We calculated a synthetic utility for each drug accounting for all of its benefits and risks.

RESULTS

Considering the overall risk-benefit, vardenafil had the highest synthetic utility among three medications; in the order of synthetic utilities: vardenafil (0.568), tadalafil (0.478) and sildenafil (0.437). However, when specific risk and benefit criteria were assessed, tadalafil had the highest synthetic utility (0.602) according to the conjoint evaluation (synthetic utility for vardenafil is 0.491 and sildenafil is 0.442, respectively). The sensitivity analysis based on the uncertainties of weight on risks of any adverse events (including serious adverse events and headache) suggested our results were robust.

CONCLUSIONS

This study provides a useful approach that comprehensively and systematically assesses and compares the risk-benefit of several treatment alternatives. Our study not only rank treatment alternatives by synthetic utilities based on the risk-benefit balance but also compare specific risk and benefit criteria between these medicines. Our results provide valuable evidence that can guide clinicians and patients in making treatment decisions.

Viral gene transfer to developing mouse salivary glands

Branching morphogenesis is essential for the formation of salivary glands, kidneys, lungs, and many other organs during development, but the mechanisms underlying this process are not adequately understood. Microarray and other gene expression methods have been powerful approaches for identifying candidate genes that potentially regulate branching morphogenesis. However, functional validation of the proposed roles for these genes has been severely hampered by the absence of efficient techniques to genetically manipulate cells within embryonic organs. Using ex vivo cultured embryonic mouse submandibular glands (SMGs) as models to study branching morphogenesis, we have identified new vectors for viral gene transfer with high efficiency and cell-type specificity to developing SMGs. We screened adenovirus, lentivirus, and 11 types of adeno-associated viruses (AAV) for their ability to transduce embryonic day 12 or 13 SMGs. We identified two AAV types, AAV2 and bovine AAV (BAAV), that are selective in targeting expression differentially to SMG epithelial and mesenchymal cell populations, respectively. Transduction of SMG epithelia with self-complementary (sc) AAV2 expressing fibroblast growth factor 7 (Fgf7) supported gland survival and enhanced SMG branching morphogenesis. Our findings represent, to our knowledge, the first successful selective gene targeting to epithelial vs. mesenchymal cells in an organ undergoing branching morphogenesis.

Salivary gland gene expression atlas identifies a new regulator of branching morphogenesis

During organ development, local changes in gene expression govern morphogenesis and cell fate. We have generated a microanatomical atlas of epithelial gene expression of embryonic salivary glands. The mouse submandibular salivary gland first appears as a single mass of epithelial cells surrounded by mesenchyme, and it undergoes rapid branching morphogenesis to form a complex secretory organ with acini connected to an extensive ductal system. Using laser capture microdissection, we collected samples from 14 distinct epithelial locations at embryonic days 12.5, 13.5, 14, and 15, and characterized their gene expression by microarray analysis. These microarray results were evaluated by qPCR of biological replicates and by comparisons of the gene expression dataset with published expression data. Using this gene expression atlas to search for novel regulators of branching morphogenesis, we found a substantial reduction in mRNA levels of GSK3β at the base of forming clefts. This unexpected finding was confirmed by immunostaining, and inhibition of GSK3β activity enhanced salivary gland branching. This first microanatomical expression atlas of a developing gland characterizes changes in local gene expression during salivary gland development and differentiation, which should facilitate the identification of key genes involved in tissue morphogenesis.

Dynamics of salivary gland morphogenesis

Salivary glands form during embryonic development by a complex process that creates compact, highly organized secretory organs with functions essential for oral health. The architecture of these glands is generated by branching morphogenesis, revealed by recent research to involve unexpectedly dynamic cell motility and novel regulatory pathways. Numerous growth factors, extracellular matrix molecules, gene regulatory pathways, and mechanical forces contribute to salivary gland morphogenesis, but local gene regulation and morphological changes appear to play particularly notable roles. Here we review these recent advances and their potential application to salivary gland tissue engineering.

Abundantly expressed hepatic genes and their differential expression in liver of prelaying and laying geese

Geese have a short egg-laying period and a low egg production rate. To induce and maintain egg laying, genes related to generating hepatic lipid for yolk deposition should be adequately expressed. Liver mRNA from 6 laying geese was extracted and used for construction of a full-length enriched cDNA library. About 2,400 clones containing gene sequences were determined and National Center for Biotechnology Information Gallus gallus Gene Index databases were used to compare and analyze these sequences. Ten highly expressed genes were selected to determine the differential expression between laying and prelay goose liver. Tissue distribution data showed that very low density apolipoprotein II, liver type fatty acid binding protein, vitellogenin I, and vitellogenin II transcripts were specifically expressed in the liver of laying geese. Ovoinhibitor, preproalbumin, alpha-2-hs-glycoprotein, and vitamin D binding protein mRNA were highly expressed in the liver and to a lesser extent in other tissues. Ovotransferrin mRNA was expressed in liver, ovary, oviduct, shell gland, brain, and adipose tissues. The concentration of transthyretin mRNA was high in the liver and brain. The mRNA concentrations of liver type fatty acid binding protein, alpha-2-hs-glycoprotein, and transthyretin in the livers of laying and prelay geese were not different. The concentrations of hepatic ovotransferrin, ovoinhibitor, preproalbumin, very low density apolipoprotein II, vitellogenin I, vitellogenin II, and vitamin D binding protein mRNA were higher in the liver of laying geese than in prelay geese, suggesting that these genes may be involved in laying function or lipid metabolism related to egg formation.

Heparin-induced thrombocytopenia associated with intra-tumour haemorrhage in cavernous sinus after cardiac myxoma surgery

Heparin-induced thrombocytopenia (HIT) is a life-threatening disorder that is associated with heparin exposure. The incidence of HIT in patients undergoing cardiac surgery is relatively rare. We present a case of intratumor haemorrhage in the cavernous sinus 1 week after cardiac surgery. The pathogenesis may be venous thrombosis and haemorrhagic infarct caused by HIT following cardiopulmonary bypass surgery. This is a rare case and has not been reported previously.

The differential expression of hepatic genes between prelaying and laying geese

Suppression subtractive hybridization was used to detect differential expression of genes in the livers of laying and prelaying geese. Liver tissues from prelaying and laying geese were dissected for mRNA extraction. The cDNA, reverse transcribed from liver mRNA of prelaying geese, was subtracted from the cDNA generated from the laying geese (forward subtraction). Five hundred seventy-six clones with possible differentially expressed gene fragments were observed by forward subtraction hybridization. After differential screening using the reverse and forward subtraction cDNA, 164 clones were subjected to gene sequence determination and further analysis. Using Northern analysis, 5 known and 8 unknown genes were shown to be highly expressed in the livers of laying geese compared with prelaying geese. Vitellogenin I, apoVLDL-II, ethanolamine kinase, G-protein gamma-5 subunit, and leucyl-tRNA synthase were highly expressed in the livers of laying geese compared with that from the prelaying geese (P<0.05). The expression of these known genes suggests that their function in the liver of laying geese is primarily involved in lipid and lipoprotein metabolism. Several of these differentially expressed genes were found to be responsive to estrogen stimulation, confirming the involvement of these genes in the egg-laying function of the goose.

Development of the activities of pancreatic and caecal enzymes in White Roman goslings

1. This study was to investigate the development of the activities of pancreatic and caecal enzymes in White Roman goslings from hatching to 28 d of age. 2. A total of 80 1-d-old goslings were used. At hatching, 3 and 7 d of age, 16 goslings (8 males and 8 females) were used. At 11, 14, 21 and 28 d of age, 8 goslings, 4 males and 4 females were selected. The activities of amylase, lipase, trypsin and chymotrypsin in each segment of the small intestine (duodenum, jejunum, ileum) and their contents and the activity of cellulase in the caecal contents were measured. 3. The specific activity (SA) of amylase in the duodenal mucosa and contents increased significantly both from 11 to 14 and 14 to 21 d of age and declined after 28 d of age. In the jejunum and ileum, there was a significant peak in the SA of amylase in the mucosa in goslings from 7 to 21 d of age. On average, the SA of lipase of mucosa and content in the small intestine was initially low but gradually increased from 14 to 21 and from 21 to 28 d of age. 4. The SA of trypsin in the contents of the duodenum and the jejunum increased both from 7 to 11 and 11 to 14 d of age and there was high activity in the ileal contents from 14 to 21 d of age. From 3 to 14 d of age, the SA of chymotrypsin in the duodenal mucosa significantly increased and peaked. There was a significant peak at 11 d of age in the SA of chymotrypsin in the duodenal or jejunal contents and in the ileal contents at 7 d. The SA of cellulase in the caecal contents increased linearly with age, reaching a plateau at 28 d of age. 5. The rate of activity development varied from hatching to 28 d of age. However, the mean SA of amylase and lipase of intestinal contents reached a peak at 21 d, trypsin and chymotrypsin at 11 d and cellulase at 28 d of age, respectively. The quantitative changes in SA of cellulase, amylase, lipase, trypsin and chymotrypsin increased by about 4-, 3-, 5-, 2- and 3-fold, respectively, in the intestinal content of goslings. Thus, development of proteases in the intestine of goslings peaked more rapidly than amylase, lipase and cellulase during the first 4 weeks.

The Expression of Pituitary Gland Genes in Laying Geese

The purpose of this study was to detect differential expression of genes in the pituitary gland in laying geese by suppression subtractive hybridization (SSH). Pituitary glands from prelaying and laying geese were dissected for mRNA extraction. The cDNA from pituitary glands of prelaying geese was subtracted from the cDNA from the pituitary glands of laying geese (forward subtraction); the reverse subtraction was also performed. We screened 384 clones with possible differentially expressed gene fragments by differential screening. Sixty-five clones from the differential screening results were subjected to gene sequencing and further analysis. We found that at least 19 genes were highly expressed in the pituitary glands of laying geese compared with prelaying geese. Among these, 6 genes (including 4 novel genes) were confirmed by virtual Northern analysis. We found that prolactin and visinin-like protein were highly expressed in the pituitary glands of laying geese compared with prelaying geese (P < 0.05). Further investigation is needed to demonstrate specific functions of the novel genes discovered in the current study.

Lateralization and prognostic value of proton magnetic resonance spectroscopy in patients with intractable temporal lobe epilepsy

BACKGROUND

The aims of this prospective study were to investigate the stability of hippocampal metabolite ratios obtained by proton magnetic resonance spectroscopy (MRS), to evaluate the ability of MRS to determine the pre-surgical lateralization of seizure focus, and to assess the relationship between MRS results and postoperative outcomes in patients with intractable temporal lobe epilepsy.

METHODS

Within- and between-acquisition variations were evaluated in 30 control subjects, using the chemical-shift imaging technique. The most stable metabolite ratio was then applied for pre-surgical evaluation of 14 patients with intractable temporal lobe epilepsy.

RESULTS

The ratio between N-acetylaspartate (NAA) and choline-containing compounds (Cho) plus creatine-phosphocreatine (Cr), i.e., NAA/(Cho+Cr), had an overall smaller percentage change between measurements (13%-28%) than did the other ratios: NAA/Cho (18%-37%), NAA/Cr (11%-60%), and Cho/Cr (19%-51%). With a mean follow-up period of 27 months (range, 12-55 months) after an anterior temporal lobectomy, 10 patients were in Engel s class I (71%), 2 were in class II (14%), and 2 were in class III (14%). Lateralization by MRS was consistent with the operation side in 11 (79%) patients, including class I in 8 patients, class II in 1 patient, and class III in 2 patients. Ranges of reduced NAA/(Cho+Cr) values were similar between patients with different post-surgical outcomes: 0.26-0.47 for class I, 0.40-0.45 for class II, and 0.34-0.40 for class III (p=0.651).

CONCLUSIONS

Proton MRS may be helpful in pre-surgical lateralization of the seizure focus in patients with intractable temporal lobe epilepsy; however, it cannot provide prognostic information about postoperative seizure control.

Hyperbaric oxygen treatment decreases post-ischemic neurotrophin-3 mRNA down-regulation in the rat hippocampus

The therapeutic effect of hyperbaric oxygen (HBO) on ischemic injury was investigated using in situ hybridization to detect the mRNA expression of neurotrophin-3 (NT-3), which is thought to play a crucial role in protecting against neuronal death induced by brain ischemia. The rats under investigation were subjected to 10 min transient forebrain ischemia, and subsequently exposed to HBO (100% oxygen, 2.5 atm absolute) for 2 h. Levels of NT-3 mRNA in the CA1, CA2 and CA3 regions, and the dentate gyrus of the hippocampus were measured after various reperfusion periods. Neuronal death in the hippocampal CA1 region was also measured by Nissl staining, seven days post ischemia. The results demonstrated that HBO treatment significantly reduced the ischemia-induced down-regulation of the NT-3 mRNA level at 4 h post ischemia, and significantly increased cell survival 7 days after reperfusion. The findings suggest that an HBO treatment maintaining the NT-3 mRNA level in the hippocampus can be beneficial to the ischemic brain within a certain time frame.

Inadvertent hypothermia causes pulseless electrical activity in a patient during cervical spine surgery--a case report

Recent studies have shown that hypothermia triples the incidence of major cardiac events. We present a happening in which a 71-year-old patient developed pulseless electrical activity (PEA) while he was undergoing cervical laminectomy for spinal stenosis in the sitting position. Thromboembolism or venous air embolism and acute myocardial infarction were respectively excluded by transesophageal echocardiography and cardiac enzymes analysis to be the causes of the cardiac event. The abnormal finding that stood out was low nasopharyngeal temperature (31 degrees C) during the procedure, which was thought to contribute to the development of the PEA episode.

Influence of sleep deprivation coupled with administration of melatonin on the ultrastructure of rat pineal gland

The effects of sleep deprivation with or without melatonin treatment on the pineal morphology in rats were studied. Five days after sleep deprivation and using electron microscopy, many of the pinealocytes exhibited structural alterations including dilation of the cisternae of the rough/smooth endoplasmic reticulum, Golgi saccules and mitochondria, and an increase in the numbers of lipid droplets, vacuoles and dense-core vesicles. These features were considered as morphological evidence of increased synthesis or secretion by the pineal gland. In addition, numerous membranous profiles, considered to be degraded cellular organelles, were observed in some pinealocytes and sympathetic nerve terminals. It is suggested that the occurrence of degenerating organelles had resulted from the deleterious effect of sleep deprivation. This may be attributed to an overload of secretory activity of the pineal gland during stress elicited by the long-term sleep deprivation, leading to functional exhaustion and irreversible damage of the oxidation-related organelles. In sleep-deprived rats receiving a single injection of melatonin (10 mg/kg) for 5 consecutive days, the above features indicative of pinealocytic activation were attenuated. In fact, all signs of degeneration of cellular organelles were rarely found. These results suggest that the pineal gland is itself a target for exogenously administered melatonin. Thus, melatonin when administered systemically may be used as a potential neuroprotective drug against neuronal damage induced by sleep deprivation.

Combined conventional and jet ventilation in airway management in tracheal tumor

Tumors on the carina are uncommon, and their anesthetic management can present a considerable challenge. The principle anesthetic consideration is ventilation and oxygenation in the face of an open airway. A 60-year-old man patient suffered a carinal tumor, which occupied 70% of the both main bronchi and bled spontaneously while coughing. Surgical resection and reconstruction were done. The carinal surgical approach was a right posterolateral thoracotomy, and the patient was placed in the left decubitus position. Because we could not insert the jet catheter past the mass, high frequency jet ventilation to ventilate the dependent lung could not be applied. Our choice was differential lung ventilation with a combination of conventional and high frequency jet ventilation modes to preserve oxygenation during tumor excision and tracheal reconstruction. An episode of desaturation was successfully treated during removal of tumor. The postoperative course was uneventful. The patient was sent to the intensive care unit after surgery and discharged on the 11th day. He received further combined chemotherapy and radiotherapy during his next admission. Fiberoptic examination on the 5 months later no evidence of recurrence. In summary, we described our airway management on carinal tumor excision, especially the tumor was so large that dependent lung jet ventilation could not employ.

Hemodynamic responses of thiopental and propofol in different-aged patients during endotracheal intubation

BACKGROUND

Thiopental and propofol are 2 popularly used anesthetic induction agents that have different pharmacological and pharmacokinetic actions. It is not clear how the hemodynamic responses differ in different-aged patients using these 2 drugs for anesthetic induction. The aim of this study was to investigate the hemodynamic responses to propofol and thiopental of different-aged patients during endotracheal intubation.

METHODS

Sixty patients, 20 to 83 years old, were included in this study. Patients were randomly divided into 6 groups according to age and different inductive anesthetics. Non-invasive blood pressure (NIBP) monitoring was performed every minute before anesthesia, during anesthetic induction with 5 mg.kg-1 thiopental or 2 mg.kg-1 propofol intravenously, and after intubation.

RESULTS

Propofol induction produced a smaller mean arterial pressure increase immediately after intubation than did thiopental induction in adult and elderly groups (101.0 +/- 18.5 and 104.0 +/- 21.1 mmHg in the propofol groups vs. 138.3 +/- 17.1 and 138.9 +/- 16.1 mmHg in the thiopental groups at 1 minute after intubation, p < 0.001 and p = 0.001, respectively). Differences in heart rate between propofol and thiopental groups were found in young and adult groups (85.1 +/- 9.2 and 81.7 +/- 10.9 in the propofol groups vs. 94.5 +/- 9.9 and 95.0 +/- 14.0 beats per minute in the thiopental groups at 1 minute after intubation, p = 0.041 and p = 0.029, respectively).

CONCLUSION

Propofol induction produced more stable hemodynamics after intubation in adult and elderly patients than did thiopental induction. Therefore, it is safer to use propofol for induction and intubation in adult and elderly patients.

Pneumopericardium after bronchoscopic carbon dioxide laser surgery--a case report

A female baby sustained pneumopericardium after bronchoscopic CO2 laser surgery for tracheal stenosis. Perioperative pneumopericardium though rare is a life-threatening condition in babies. The symptoms are usually not specific such as hypotension, bradycardia, muffled heart sound, cardiovascular collapse, etc. The causes and clinical findings of pneumopericardium were reviewed, as are the radiographic features so as to differentiate the condition from pneumomediastinum. Early recognition of pneumopericardium is important, because emergent pericardiocentesis may be required if there is clinical evidence of cardiac tamponade.

A confidence-set approach for finding tightly linked genomic regions

As more studies adopt the approach of whole-genome screening, geneticists are faced with the challenge of having to interpret results from traditional approaches that were not designed for genome-scan data. Frequently, two-point analysis by the LOD method is performed to search for signals of linkage throughout the genome, for each of hundreds or even thousands of markers. This practice has raised the question of how to adjust the significance level for the fact that multiple tests are being performed. Various recommendations have been made, but no consensus has emerged. In this article, we propose a new method, the confidence-set approach, that circumvents the need to correct for the level of significance according to the number of markers tested. In the search for the gene location of a monogenic disorder, multiplicity adjustment is not needed in order to maintain the desired level of confidence. For complex diseases involving multiple genes, one needs only to adjust the level of significance according to the number of disease genes--a much smaller number than the number of markers in a genome screen-to ensure a predetermined genomewide confidence level. Furthermore, our formulation of the tests enables us to localize disease genes to small genomic regions, an extremely desirable feature that the traditional LOD method lacks. Our simulation study shows that, for sib-pair data, even when the coverage probability of the confidence set is chosen to be as high as 99%, our approach is able to implicate only the markers that are closely linked to the disease genes.

Effects of heparin immobilization on the surface characteristics of a biological tissue fixed with a naturally occurring crosslinking agent (genipin): an in vitro study

Heparinized biomaterials have been used to manufacture blood-contacting prostheses. The present study was intended to characterize the surface properties of a genipin-fixed biological tissue immobilized with heparin using the methods of ionic binding (the /h-i tissue) or covalent binding via multi-point attachment (the /h-m tissue) or end-point attachment (the /h-e tissue). The surface characteristics of test tissues evaluated were water contact angle, surface tension, protein adsorption, platelet adhesion, and cellular compatibility. Nonheparinized and the glutaraldehyde-fixed counterparts were used as controls. It was found that immobilization of heparin on the glutaraldehyde- and genipin-fixed tissues increased their hydrophilicity and surface tension and suppressed their mole ratio of adsorbed fibrinogen to adsorbed albumin and the amount of platelets adhered. Among the heparinized tissues, the /h-m tissue was more hydrophobic and had a higher mole ratio of adsorbed fibrinogen to adsorbed albumin and a greater amount of platelets adhered than the /h-i and /h-e tissues. In general, the surface characteristics of the /h-i tissue were comparable to the /h-e tissue. However, it is known that the ionically immobilized heparin may be displaced from the surface by an ion-exchange mechanism when exposed to blood. There were no significant differences in hydrophilicity, surface tension, the mole ratio of adsorbed fibrinogen to adsorbed albumin, and the amount of platelet adhesion between the glutaraldehyde- and genipin-fixed tissues in comparison with their respective counterparts. However, the cellular compatibility of the genipin-fixed tissues with or without heparinization was significantly superior to its glutaraldehyde-fixed counterparts.

Anterior mediastinal tumour identified by intraoperative transesophageal echocardiography

PURPOSE

To report a child with anterior mediastinal tumour misdiagnosed as pericardial effusion who had been sent to the operating theatre for drainage. After induction of general anesthesia she developed cardio-respiratory collapse. The diagnosis was made with the aid of transesophageal echocardiography (TEE).

CLINICAL FEATURES

A 14-yr-old girl suffered from cough and intermittent fever for one month before admission. Four days before admission, she became orthopneic and was admitted to the intensive care unit. Precordial echocardiography showed an anterior and posterior echolucent space between the pericardium and epicardium that was thought to be a pericardial effusion. She was sent to the operating room for emergency drainage. After induction of general anesthesia, breath sounds were not heard on the left side of the chest. The patient developed increasing hypoxemia and hypotension despite cardiocentesis. A TEE determined that an anterior mediastinal mass was the cause of her hypoxemia and hypotension. The tumour was debulked and the patient made an uneventful postoperative recovery.

CONCLUSION

In this case, the correct diagnosis of an anterior mediastinal mass was made with TEE. The place of TEE may be indicated in patients with unexplained hypoxemia and hypotension.

Different astroglial reaction between the vagal dorsal motor nucleus and nucleus ambiguus following vagal-hypoglossal nerve anastomosis in cats

The dorsal motor nucleus of the vagus (DMV) and nucleus ambiguus (NA) were both traced with horseradish peroxidase (HRP) retrograde labelling technique after vagal-hypoglossal nerve anastomosis (VHA). By light microscopy, reinnervation of the new target, viz. tongue skeletal musculature, by DMV and NA was established at 22 days postoperation (dpo) as shown by the neuronal labelling with HRP. Ultrastructurally, signs of retrograde degeneration occurred in some DMV and NA neurons between 3 and 25 days after VHA. The incidence of darkened dendrites, an early sign of dendritic loss, was more common in the DMV compared to the NA. Accompanying the neuronal alteration were drastic astrocytic reactions in the DMV, but not in the NA. Between 3 and 7 dpo, the astrocytes in the DMV showed extensively hypertrophied processes and by 22 dpo, the somata and dendrites of HRP-labelled DMV neurons, but not NA's, appeared to be delineated by the increased lamellar astrocytic processes. Such a feature was sustained throughout the remaining postoperative intervals up to 500 dpo. It is concluded that the DMV motoneurons being autonomic in nature are probably not conducive to the newly acquired target organ. Hence, the insulation of the regenerating DMV motoneurons by the astroglial ensheathment would be vital in the neuronal remodelling and reconstruction of the vagal-hypoglossal pathway.

Anesthesia of CO2 laser surgery in a patient with Hunter syndrome: case report

Hunter syndrome (mucopolysaccharidosis, type II; MPS II) is one of a heterogeneous group of recessively inherited mucopolysaccharide storage diseases. Patients with mucopolysaccharidosis show progressive involvement and derangement of many organs, especially upper airway anomalies, which are the major cause of perioperative death. In recent years, a CO2 laser is often applied to upper airway lesions. A 16-year-old patient suffering from Hunter syndrome was scheduled for CO2 laser surgery because of sleep apnea and respiratory stridor. Otolaryngological examination revealed bulging of the bilateral false cord with stenosis of the glottis. We adopted sevoflurane mask induction and high-frequency jet ventilation to overcome the perioperative airway problems. The anesthetic course was uneventful, and the patient was discharged 2 days after the operation.

F wave monitoring during surgery for adult tethered cord syndrome--a case report

We would like to report our first attempt in intraoperative study of F wave response electromyography (EMG) to monitor the spinal motor function during a spinal surgery for excision of a giant lumbosacral lipoma.

Coronary artery calcium evaluation by electron beam computed tomography and its relation to new cardiovascular events

Electron beam computed tomography is widely used to screen for coronary artery calcium (CAC). We evaluated the relation of CAC to future cardiovascular disease events in 926 asymptomatic persons (735 men and 191 women, mean age 54 years) who underwent a baseline electron beam computed tomographic scan. All subjects included in this report returned a follow-up questionnaire 2 to 4 years (mean 3.3) after scanning, inquiring about myocardial infarction, stroke, and revascularizations. Sixty percent of men and 40% of women had a positive scan at baseline. Twenty-eight cardiovascular events occurred and were confirmed by blinded medical record review. The presence of CAC (a total calcium score of >0) and increasing score quartiles were related to the occurrence of new myocardial infarction (p <0.05), revascularizations (p <0.001), and total cardiovascular events (p <0.001). Those with scores at or above the median (score of 5) had a relative risk of 4.5 (p <0.01) for new events. From Cox regression models, adjusted for age, gender, and coronary risk factors, the relative risks for those with scores of 81 to 270 and -271 (compared with 0) for cardiovascular events were 4.5 (p <0.05) and 8.8 (p <0.001), respectively. These data support previous reports showing CAC to be a modest predictor of future cardiovascular events.

Nerve transfer to the median nerve using parts of the ulnar and radial nerves in the rabbit--effects on motor recovery of the median nerve and donor nerve morbidity

In this study, motor re-innervation of the median nerve by transfer of one-third, one-half, and two-thirds of either the agonistic ulnar nerve or the antagonistic radial nerve was investigated in both extremities of 20 rabbits. Recipient median nerve: Muscle contraction force of the flexor digitorum sublimus muscle after a one-third and a one-half of the ulnar nerve transfer achieved an average of 75 and 97% muscle power respectively as compared to conventional end-to-end neurorrhaphy. Muscle contraction force after one-third or one-half of the radial nerve transfer was significantly lower (36%). Donor nerves: Extensor carpi radialis muscle or flexor carpi ulnaris muscle contraction force 6 months postoperatively demonstrated a significant decrease after a one-half ulnar nerve and a two-thirds ulnar or radial nerve transfer, but not after a one-third transfer of either radial or ulnar nerves. Histologically, the number of axons in the re-innervated median nerve and both donor nerves distal to the coaptation site seemed to follow variable patterns. It was concluded that in the rabbit use of one-third of the agonistic ulnar nerve for re-innervation of the median nerve results in useful motor recovery with negligible donor site morbidity. Clinically, this technique may offer an alternative option for proximal nerve injuries or for free functioning muscle transplantations.

In vitro surface characterization of a biological patch fixed with a naturally occurring crosslinking agent

The study was designed to characterize the surface properties (including water contact angle, surface tension, protein adsorption, platelet adhesion, and cellular compatibility) of a biological patch fixed with genipin, a naturally occurring crosslinking agent. Fresh and glutaraldehyde-fixed counterparts were used as controls. It was found that both glutaraldehyde and genipin are effective crosslinking agents for biological tissue fixation. Fixation of biological tissue with glutaraldehyde or genipin significantly increased its hydrophilicity and surface tension and reduced its mol ratio of adsorbed fibrinogen to adsorbed albumin as well as the amount of adhered platelet. There were no significant differences in hydrophilicity, surface tension, the mole ratio of adsorbed fibrinogen to adsorbed albumin, and the amount of platelet adhesion between the glutaraldehyde- and genipin-fixed tissues. However, the cellular compatibilities of fresh and the genipin-fixed tissues were significantly superior to the glutaraldehyde-fixed tissue.

A descriptive analysis of participant characteristics and patterns of substance use in the CSAT methamphetamine treatment project: the first six months

The CSAT Methamphetamine Treatment Project (MTP) is a multisite study with a two-fold purpose: to assess the feasibility and outcomes generated by a technology transfer of the Matrix treatment model for methamphetamine (MA) abuse into several community-based treatment programs, and specifically to compare outcomes of treatment as usual at each site with outcomes of the Matrix model, as implemented in each site. The study comprises seven sites, geographically situated in Hawaii, Northern and Southern California, and Montana. This article presents a demographic description of the cohort, and describes patterns of drug use, abuse, and related problems among the 169 participants recruited in the first six months of the study, from April through September 1999. Specific analyses presented include: demographic composition of the sample with respect to gender, age, ethnicity, education completed, employment status, and income; primary drug used, and mean percent of days using various drugs including MA, alcohol, and marijuana; and percent of sample reporting various routes of drug administration. Mean baseline Addiction Severity Index composite scores are presented that describe medical, employment, alcohol, drug, legal, family/social, and psychiatric status for the sample. Also presented here are comparisons of this preliminary population to other populations reported in the literature. This early subset of MTP participants is similar to other methamphetamine-abusing populations described in the literature in age, years of education, income, and mean years of use. However, because of its multisite structure and the locations of its constituent sites, the MTP population has greater variation in ethnic makeup than do populations from other studies, offering an opportunity to provide useful new information about drug use patterns and treatment responses in populations not previously studied.

Selection of donor nerves--an important factor in end-to-side neurorrhaphy

We have examined the effects of end-to-side neurorrhaphy on peripheral nerve regeneration using the median nerve as recipient nerve and either the antagonistic radial nerve or the agonistic ulnar nerve as donor nerves in rat upper limbs. A perineural window was created in all cases. Motor recovery up to 16 weeks postoperation was tested with the grasping test. No recovery of motor function was evident after end-to-side neurorrhaphy of the median nerve to the antagonistic radial nerve, whereas six of eight rats with end-to-side neurorrhaphy to the agonistic ulnar nerve achieved 367 g +/- 47 g grasping power as compared to 526 g +/- 6 g in end-to-end coapted control animals. No significant difference in flexor digitorum sublimus-motor nerve conduction velocity was found among all three groups. Radial nerve stimulation produced simultaneous contraction of both extensor and flexor muscles of the lower arm that disabled any coordinated movement of the paw. Histology (toluidine blue, acetylcholinesterase-stain) showed multiple regenerated (motor)-axons distal to the coaptation site in the median nerve. Reinnervation of the median nerve solely by the respective donor nerve was demonstrated by a retrograde double labelling technique. These results show that averaged 70% muscle power as compared to end-to-end neurorrhaphy with well coordinated muscle function can be achieved by axonal sprouting through end-to-side neurorrhaphy if an agonistic nerve is used as donor nerve. However, satisfying results are unpredictable. Antagonistic nerves show the ability to induce axonal regeneration, but no useful function can be expected.

Anesthesia with deep hypothermic circulatory arrest for giant basilar aneurysm surgery

The application of deep hypothermic circulatory arrest (DHCA) as an adjutant technique in anesthetic management for surgery of giant and complex cerebral aneurysm has been clinically recognized with piling up experience in many institutes. DHCA provides the advantages such as a bloodless surgical field and protection of the brain, all of which make a precise clipping of the aneurysm possible and thus it lowers the mortality rate which could be extremely high without it. Nevertheless, in application, the disadvantages of this technique includes comparatively inefficient and uneven cooling or rewarming, severe physiological change, cardiac distension and arrhythmia during cardiopulmonary bypass (CPB), hemorrhage from systemic heparinization and brain damage due to inadequate protection, none of which has ever been stressed. Since many giant aneurysms are found inoperable during exploration with application of DHCA, it would change the fate of the patients, and the clinical value of DHCA in such an instance becomes contradictive and disputable. We would like to present our experience in a case who, because of a giant basilar aneurysm, underwent surgical correction under DHCA retrograde cerebral perfusion (RCP) with cerebral function monitoring including electroencephalography (EEG), brainstem auditory evoked potentials (BAEP), thermal diffusion cerebral blood flowmetry, study of the change of extracellular concentration of excitatory amino acid, glutamate and aspartate, and off-line neurochemical analysis with cerebral microdialysis technique.

The evaluation of false negative mammography from malignant and benign breast lesions

Preoperative mammograms from 395 breast cancers and 132 benign breast lesions were enrolled for this study. The false-negative (FN) rate for breast cancers from preoperative reading was 9.6% with 38 breast cancers missed on mammograms. The statistically significant differences occurred between true-positive (TP) and FN cancers for younger age (P<.025), smaller lesion size (P<.001), denser breast (P<.05), deep retroglandular location (P<.001). None of the FN cancers exhibited calcifications. The FN rate for mammography for benign breast lesions from preoperative reading was 18.9% with 25 lesions misdiagnosed. The statistically significant difference between benign TP and FN lesions occurred for central and subareolar location (P<.025). Exploration of possible factors and imaging features in FN mammograms can help reduce the FN rate for mammography.

Dietitian intervention improves lipid values and saves medication costs in men with combined hyperlipidemia and a history of niacin noncompliance

We asked if medical nutrition therapy (MNT) administered by registered dietitians could lead to beneficial clinical and financial outcomes in men with combined hyperlipidemia (hypercholesterolemia and hypertriglyceridemia). A retrospective chart review was conducted on 73 men with combined hyperlipidemia who were being considered for statin therapy because of a previous history of noncompliance with niacin therapy. Subjects participated in an 8-week dietitian intervention program as a qualifying requirement, before statin therapy. Patient records were reviewed to determine the beginning and ending serum lipid concentrations and the number and length of dietitian sessions. Complete information was available on 43 subjects, aged 60.7 +/- 10.1 years (mean +/- standard deviation). Total dietitian intervention time was 169 +/- 19 minutes in 2.7 +/- 0.6 sessions (range = 2 to 4 sessions) during 6.5 +/- 2.2 weeks of MNT (range = 4 to 8 weeks). MNT lowered levels of total cholesterol 11% (P < .001), low-density lipoprotein cholesterol 9% (P < .001), and triglycerides 22% (P < .0001) and body mass index 2% (P < .0001); MNT raised high-density lipoprotein cholesterol levels 4%. After dietitian intervention, only 15 of 30 eligible patients required antihyperlipidemic medications, which led to an annual cost savings of $27,449.10 or $638.35 per patient. A cost saving of $3.03 in statin therapy was realized for each dollar spent on MNT. We conclude that an average of 3 individualized dietitian visits of 1 hour each over an 8-week period has a beneficial effect in treating patients with combined hyperlipidemia and recommend consideration of MNT as a cost-effective intervention.

Multiple comparison of entropies with application to dinosaur biodiversity

Did the biodiversity of dinosaurs decline, or did it remain more or less constant before their mass extinction 65 million years ago? Sheehan et al. (1991, Science, 835-839) reported that the biodiversity of families of dinosaur species remained more or less constant preceding their extinction, suggesting extinction due to a cataclysmic event such as an asteroid strike. But that claim was based on the incorrect interpretation that a large p value associated with a test of null hypothesis of equality supports that null hypothesis. To assess whether there is a basis for such a claim, we formulate the problem as one of practical equivalence, in analalogy to bioequivalence. We then develop reliable practical equivalence confidence intervals for differences of entropies by applying the bootstrap-t technique to a nearly pivotal quantity. Confidence intervals for changes in the biodiversity of dinosaurs are then computed, allowing the reader to assess whether there is evidence of near constancy of dinosaur biodiversity before extinction.

Evaluation of gelatin hydrogel crosslinked with various crosslinking agents as bioadhesives: in vitro study

Bioadhesives are used for tissue adhesion and hemostasis in surgery. A gelatin-resorcinol mixture crosslinked with formaldehyde (GRF glue) and/or glutaraldehyde (GRG) is used for this purpose. Although the bonding strength of the GRF glue to tissue is satisfactory, concerns about the cytotoxicity of formaldehyde are reported in the literature. It was suggested that the cytotoxicity problem of the GRF glue may be overcome by changing its crosslinking method. The study was therefore undertaken to assess the feasibility of using an epoxy compound (GRE glue), a water-soluble carbodiimide (GAC glue), or genipin (GG glue) to crosslink with a gelatin hydrogel as new bioadhesives. GRF glue and GRG glue were used as controls. The results of our cytotoxicity study suggested that the cellular compatibility of the GAC and GG glues was superior to the GRF, GRG, and GRE glues. The gelation time for the GG glue was relatively longer than the GRF and GRG glues, while no gelation time could be determined for the GAC glue. Additionally, it took approximately 17 h for the GRE glue to become adhesive. The GRF and GRG glues had the greatest bonding strengths to tissue among all test adhesives, while the bonding strengths of the GAC and GG glues were comparable. In contrast, there was almost no bonding strength to tissue for the GRE glue. However, the GRF and GRG glues were less flexible than the GAC and GG glues. Subsequent to the bonding strength measurement, each test adhesive was found to adhere firmly to the tissue surface and underwent cohesive failure during the bond breaking. In conclusion, the GRF and GRG glues may be used as tissue adhesives when their ability to bind tissue rapidly and tightly is required; the GAC and GG glues are preferable when the adhesive action must be accompanied with minimal cytotoxicity and stiffness; and the GRE glue is not suitable for bioadhesion in clinical applications.

Ocular predictors of the onset of juvenile myopia

PURPOSE

The purpose of this study was to identify reliable predictors of the onset of juvenile myopia.

METHODS

The data from 554 children enrolled in the Orinda Longitudinal Study of Myopia (OLSM) as nonmyopes with baseline data from the third grade were evaluated to develop a predictive profile for later onset of juvenile myopia. Myopia was defined as at least -0.75 D of myopia in the vertical and horizontal meridians of the right eye as measured by cycloplegic autorefraction (n = 45 children). Chosen predictors were refractive error and the ocular components: corneal power, Gullstrand crystalline lens power, and axial length. Sensitivity and specificity were calculated. Receiver operating characteristic (ROC) curves were generated to evaluate and compare these predictors singly and combined.

RESULTS

Refractive error, axial length, Gullstrand lens and pod corneal power were all significant predictive factors for the onset of juvenile myopia. The best single predictor of future myopia onset in the right eye was the right eye's cycloplegic autorefraction spherical refractive error value (mean sphere across 10 readings) at baseline. For a cut point of less than +0.75 D hyperopia in the third grade, sensitivity was 86.7% and specificity was 73.3%. The area under the ROC curve for this mean sphere was 0.880. Producing a logistic model combining mean sphere, corneal power, Gullstrand lens power, and axial length results in a slight improvement in predictive ability (area under the ROC curve = 0.893).

CONCLUSIONS

Onset of juvenile myopia can be predicted with moderate accuracy using the mean cycloplegic, spherical refractive error in the third grade. Measurement of other ocular components at this age improves predictive ability, albeit incrementally. Further improvements in the prediction of myopia onset will require the use of longitudinal data in addition to one-time measurement of refractive error and the ocular components.

Proton MR spectroscopy in patients with complex partial seizures: single-voxel spectroscopy versus chemical-shift imaging

BACKGROUND AND PURPOSE

Proton MR spectroscopy has recently been applied to the evaluation of seizures, but few comparisons have been made between different clinical spectroscopic techniques. Our goal was to determine whether there is a significant difference between hippocampal NAA/(Cho+Cr) ratios obtained by single-voxel spectroscopy (SVS) and by chemical-shift imaging (CSI).

METHODS

Twelve healthy adults and eight patients with complex partial seizures were studied on a 1.5-T MR scanner using a proton SVS method. Another 12 healthy adults and 10 patients with complex partial seizures were recruited for a proton CSI study, which was performed on a different 1.5-T MR system. The NAA/(Cho+Cr) ratio was calculated from the integral peak areas by curve fitting. The two-tailed t-test was used for statistical analysis.

RESULTS

The mean value +/- standard deviation of the hippocampal NAA/(Cho+Cr) ratio in healthy control subjects was 0.63 +/- 0.07 by SVS, with 0.62 +/- 0.15 for the anterior hippocampus and 0.65 +/- 0.11 for the posterior hippocampus by CSI. There was no significant difference between the control group data obtained by SVS and those by CSI, nor was there a regional difference in the CSI NAA/(Cho+Cr) ratio in the hippocampus. Relative to the control group, the patients with seizures had a significant decrease in the NAA/(Cho+Cr) ratio in the abnormal hippocampus: -28% by SVS, and -24% in the anterior hippocampus and -18% in the posterior hippocampus by CSI. Proton SVS and CSI detected hippocampal abnormalities, unilateral or bilateral, in all patients of each group.

CONCLUSION

Under similar measurement conditions, proton SVS and CSI provide similar NAA/(Cho+Cr) ratios among healthy control subjects, and they possess comparable ability for detecting hippocampal abnormalities in patients with complex partial seizures.

Interference coatings based on synthesized silicon nitride

Silicon nitrides are synthesized by ion-assisted deposition with only one coating material and a nitrogen-ion-beam source. All the SiN(x) films are amorphous and mechanically strong. A wide range of refractive indices from 3.43 to 1.72 at a wavelength of 1550 nm is obtained. Near-IR antireflection coating and a bandpass filter based on the multilayers of SiN(x) and Si are demonstrated.