Potentially inappropriate medications among older patients with Parkinson's disease: a cross-sectional analysis of a national health insurance database in China

BACKGROUND

With the rapid aging trend of China's population, the issue of drug rational use in older adults has become more and more prominent. Parkinson's disease (PD) is the one of the most common age-related neurodegenerative disorders. Pharmaceutical treatment plays a cardinal role in alleviating motor and non-motor symptoms to improve the quality of life of patients with PD. Patients with PD have complex medical needs yet little is known about the use of potentially inappropriate medications (PIM) among them in China. We quantify the prevalence of PIM use and identify its predictors among older persons with PD in China.

METHODS

We conducted a cross-sectional analysis using a national representative database of all medical insurance beneficiaries across China, extracting records of ambulatory visits of older adults with PD between 2015 and 2017. Beneficiaries aged 65 and above were eligible for inclusion. The prevalence of patients exposed to overall PIMs and PIMs related to motor and cognitive impairment was calculated based on Beers Criteria 2015 version. Potential predictors of PIM concerning patients' characteristics were estimated using multivariate logistic regression.

RESULTS

A total of 14,452 older adults with PD were included. In total, 8,356 (57.8%) patients received at least one PIM; 2,464 (17.1%) patients received at least one motor-impairing PIM and 6,201 (42.9%) patients received at least one cognition-impairing PIM. The prevalence of overall PIM use was higher in patients of older age group (54.7% [65-74] vs. 59.5% [75-84; OR, 1.22; 95% CI, 1.14-1.31] vs.65.5% [≥ 85; OR, 1.58; 95% CI, 1.38-1.80) and females (61.4% [female] vs. 55.0% [males; OR, 0.77; 95% CI, 0.72-0.82).

CONCLUSIONS

Prescribing PIMs for older adults with PD was common in China, especially for females and older age groups, yet younger patients were more inclined to be prescribed with motor or cognition-impaired PIMs. Our findings represent a clear target awaiting multidimensional efforts to promote the rational prescribing of medications for this vulnerable population.

Appropriate use of antibiotics for acute respiratory infections at primary healthcare facilities in China: a nationwide cross-sectional study from 2017 to 2019

Background

The appropriateness of antibiotic use for acute respiratory infections (ARIs) in Chinese primary healthcare facilities (PHFs) remained uncertain. We aimed to evaluate to what degree antibiotic prescribing for ARIs were aligned with guideline recommendations in primary settings across China.

Methods

We collected outpatient prescriptions from 262 Chinese PHFs in 27 cities of six provinces between 2017 and 2019. The appropriate antibiotic prescribing was defined as prescribing antibiotic classes that were recommended by Chinese clinical guidelines, if patients were prescribed antibiotics. We evaluated the magnitude of antibiotics prescribed for acute upper respiratory infections (AURIs), acute bronchitis, and community-acquired pneumonia (CAP) and their appropriateness.

Findings

Overall, 55.1% (87,684/159,150), 66.8% (30,836/46,153), and 68.5% (4615/6733) of outpatients with AURIs, acute bronchitis, and CAP treated at PHFs in China were prescribed with antibiotics. Of all antibiotic prescriptions, only 20.0% (17,542/87,684), 18.6% (5724/30,836) and 69.6% (3211/4615) used antibiotic classes that were recommended by the guidelines for AURIs, acute bronchitis, and CAP, respectively. Patients residing in the Chinese central region (17.0%, 15.4%, 69.3% for AURIs, acute bronchitis, and CAP, respectively) were less likely to be prescribed with antibiotics that were appropriately selected.

Interpretation

Unnecessary antibiotics were widely prescribed for patients with AURIs or acute bronchitis and most patients with ARIs did not receive guideline-recommended antibiotic classes in Chinese PHFs. Interventions to promote evidence-based treatment and the appropriate use of antibiotics are urgently needed at the primary level across China.

Funding

This work was supported by the National Natural Science Foundation of China [grant number 72074007, 81973294].

Correlation between clinical trial endpoints of marketed cancer drugs and reimbursement decisions in China

Objective

This study aimed to assess whether different clinical trial endpoints in pivotal trials of cancer drugs were associated with reimbursement decisions in China.

Materials and methods

Cancer drugs marketed before June 30^th, 2021 with publicly available technical review reports for application of drug registration on Center for Drug Evaluation (CDE) website were reviewed. The trial design characteristics and relevant clinical outcomes [e.g., overall survival (OS), progression-free survival (PFS) and objective response rate (ORR)] were extracted from the technical review reports, while the reimbursement decisions were reviewed from National Healthcare Security Administration (NHSA) website. The differences in trial characteristics and clinical outcomes between drugs with positive reimbursement decisions and negative ones were compared by hypothesis test (Pearson's chi-squared test, Fisher's exact test, independent samples t-test and Mann-Whitney U test). The correlation between different clinical trial endpoints and reimbursement decisions was analyzed by multivariate logistic regression.

Results

There were 112 cancer drug indications included in this study. Among these indications, 76 received a positive reimbursement decision, and the most common primary endpoints of them were PFS (42.1%) and ORR (30.3%). Taking PFS (OR = 7.333) and ORR (OR = 5.271) as the primary endpoints were more likely to receive a positive reimbursement decision compared with OS (P = 0.003). The proportion of drugs marketed with phase I (75.0%) and phase II (85.7%) clinical trials receiving positive reimbursement decisions are significantly higher than those marketed with phase III clinical trials (61.3%, P = 0.043). The magnitude of clinical benefit only had subtle influences (P_{risk benefit - OS} = 0.627, P_{risk benefit - PFS} = 0.087, P_{survival benefit - OS} = 0.545, P_{survival benefit - PFS} = 0.189) on the drug reimbursement decisions, however, the drug prices and clinical needs also made a difference on that.

Conclusion

This study found that, in Chinese drug price negotiations from 2017 to 2021, policymakers have focused more on meeting clinical needs and filling therapeutical gaps in National Reimbursement Drug List (NRDL), while requirements for the selection of primary endpoints, clinical trial phases, and clinical benefits have been reduced. In the future, emphasis should be put on the use of surrogate endpoints and clinical benefits.

Turbostratic Boron-Carbon-Nitrogen and Boron Nitride by Flash Joule Heating

Turbostratic layers in 2D materials have an interlayer misalignment. The lack of alignment expands the intrinsic interlayer distances and weakens the optical and electronic interactions between adjacent layers. This introduces properties distinct from those structures with well-aligned lattices and strong coupling interactions. However, direct and rapid synthesis of turbostratic materials remains a challenge owing to their thermodynamically metastable properties. Here, a flash Joule heating (FJH) method to achieve bulk synthesis of boron-carbon-nitrogen ternary compounds with turbostratic structures by a kinetically controlled ultrafast cooling process that takes place within milliseconds (10³  to 10⁴ K s^-1 ) is reported. Theoretical calculations support the existence of turbostratic structures and provide estimates of the energy barriers with respect to conversion into the corresponding well-aligned counterparts. When using non-carbon conductive additives, a direct synthesis of boron nitride is possible. The turbostratic nature facilitates mechanical exfoliation and more stable dispersions. Accordingly, the addition of flash products to a poly(vinyl alcohol) nanocomposite film coating a copper surface greatly improves the copper's resistance to corrosion in 0.5 m sulfuric acid or 3.5 wt% saline solution. FJH allows the use of bulk materials as reactants and provides a rapid approach to large quantities of the hitherto hard-to-access turbostratic materials.

Porphyrin-based donor-acceptor COFs as efficient and reusable photocatalysts for PET-RAFT polymerization under broad spectrum excitation

Covalent organic frameworks (COFs) are crystalline and porous organic materials attractive for photocatalysis applications due to their structural versatility and tunable optical and electronic properties. The use of photocatalysts (PCs) for polymerizations enables the preparation of well-defined polymeric materials under mild reaction conditions. Herein, we report two porphyrin-based donor-acceptor COFs that are effective heterogeneous PCs for photoinduced electron transfer-reversible addition-fragmentation chain transfer (PET-RAFT). Using density functional theory (DFT) calculations, we designed porphyrin COFs with strong donor-acceptor characteristics and delocalized conduction bands. The COFs were effective PCs for PET-RAFT, successfully polymerizing a variety of monomers in both organic and aqueous media using visible light (λ max from 460 to 635 nm) to produce polymers with tunable molecular weights (MWs), low molecular weight dispersity, and good chain-end fidelity. The heterogeneous COF PCs could also be reused for PET-RAFT polymerization at least 5 times without losing photocatalytic performance. This work demonstrates porphyrin-based COFs that are effective catalysts for photo-RDRP and establishes design principles for the development of highly active COF PCs for a variety of applications.

Effect of monensin on milk fatty acid profile in dairy cows and on the use of fatty acids for early diagnosis of elevated blood plasma concentrations of nonesterified fatty acids and hyperketonemia

This work examined the effects of precalving administration of continuous-release monensin capsule on postcalving milk fatty acid (FA) profile and on the accuracy of FA as a biomarker in the early identification of cows with elevated blood plasma nonesterified fatty acids (NEFA) and β-hydroxybutyrate (BHB) concentrations. Approximately 3 wk before expected calving, 203 multiparous Estonian Holstein cows were randomly divided into control (CO; n = 116) and experimental (MO; n = 87) groups, and a continuous-release capsule of monensin was administered to the MO cows. Blood samples were taken daily in the first 4 d postpartum, then on the sixth or seventh day in milk, twice in the second week, and thenceforth once per week until the end of the sixth week. Milk samples were taken once from 4 to 7 d in milk, twice in the second week, and thenceforth once per week. Blood samples were analyzed for NEFA and BHB, and milk was analyzed for FA concentrations. Cows with postpartum BHB concentrations ≥1.2 mmol/L at least once during the 6 wk were classified as hyperketonemic (HYK), and cows with NEFA concentrations ≥1.0 mmol/L as having elevated concentration of NEFA (NEFA_H). The ability of FA to predict NEFA_H and HYK cows was studied with logistic regression and receiver operating characteristic curve analysis and the identification accuracy was estimated by area under the receiver operating characteristic curve. For these analyses, we used FA measured on the ninth day after calving. Monensin administration affected FA mobilization and metabolism of the animals as blood NEFA were lower in the MO group on wk 1 and wk 3, and BHB values were considerably lower from wk 1 to wk 4 compared with the CO group. The FA dynamics were generally similar for MO and CO groups. Monensin administration resulted in higher concentrations of C15:0, C16:0, iso C17:0, anteiso C15:0, anteiso C17:0, total trans monounsaturated FA, and C18:2 cis-9,trans-11, and lower proportions of C18:0, C18:1 cis-9, and most of the iso FA. The identification accuracy of NEFA_H and HYK cows was higher in the CO compared with the MO group and for the identification of HYK compared with NEFA_H cows (0.75-0.77 vs. 0.78-0.80 in the CO group, and 0.61-0.66 vs. 0.68-0.75 in the MO group for NEFA_H vs. HYK, respectively). For all FA, the threshold values to identify NEFA_H and HYK cows were different in the CO and MO groups. Results suggest that specific threshold values for the identification of NEFA_H and HYK cows could be applicable only within similar feeding conditions and rumen environment.

Body condition and insulin resistance interactions with periparturient gene expression in adipose tissue and lipid metabolism in dairy cows

Adipose tissue plays an important role in a cow's ability to adapt to the metabolic demands of lactation, because of its central involvement in energy metabolism and immunity. High adiposity and adipose tissue resistance to insulin are associated with excessive lipid mobilization. We hypothesized that the response to a glucose challenge differs between cows of different body condition 21 d before and after calving and that the responses are explainable by gene expression in subcutaneous adipose tissue (SAT). In addition, we aimed to investigate insulin resistance with gene expression in SAT and lipid mobilization around parturition. Multiparous Holstein cows were grouped according to body conditions score (BCS) 4 wk before calving, as follows: BCS ≤ 3.0 = thin (T, n = 14); BCS 3.25 to 3.5 = optimal (O, n = 14); BCS ≥ 3.75 = over-conditioned (OC, n = 14). We collected SAT on d -21 and d 21 relative to calving. A reverse-transcriptase quantitative (RT-q)PCR was used to measure gene expression related to lipid metabolism. One hour after the collection of adipose tissue, an intravenous glucose tolerance test was carried out, with administration of 0.15 g of glucose per kg of body weight (with a 40% glucose solution). Once weekly from the first week before calving to the third week after calving, a blood sample was taken. The transition to lactation was associated with intensified release of energy stored in adipose tissue, a decrease in the lipogenic genes lipoprotein lipase (LPL) and diacylglycerol O-acyltransferase 2 (DGAT2), and an increase in the lipolytic gene hormone-sensitive lipase (LIPE). On d -21, compared with T cows, OC cows had lower mRNA abundance of LPL and DGAT2, and the latency of fatty acid response after glucose infusion was also longer (8.5 vs. 23.3 min) in OC cows. Cows with higher insulin area under the curve on d -21 had concurrently lower LPL and DGAT2 gene expression and greater concentration of fatty acids on d -7, d 7, and d 14. In conclusion, high adiposity prepartum lowers the whole-body lipid metabolism response to insulin and causes reduced expression of lipogenic genes in SAT 3 weeks before calving. In addition, more pronounced insulin release after glucose infusion on d -21 is related to higher lipid mobilization around calving, indicating an insulin-resistant state, and is associated with lower expression of lipogenic genes in SAT.

Adipose tissue insulin receptor and glucose transporter 4 expression, and blood glucose and insulin responses during glucose tolerance tests in transition Holstein cows with different body condition

Glucose uptake in tissues is mediated by insulin receptor (INSR) and glucose transporter 4 (GLUT4). The aim of this study was to examine the effect of body condition during the dry period on adipose tissue mRNA and protein expression of INSR and GLUT4, and on the dynamics of glucose and insulin following the i.v. glucose tolerance test in Holstein cows 21 d before (d -21) and after (d 21) calving. Cows were grouped as body condition score (BCS) ≤3.0 (thin, T; n = 14), BCS = 3.25 to 3.5 (optimal, O; n = 14), and BCS ≥3.75 (overconditioned, OC; n = 14). Blood was analyzed for glucose, insulin, fatty acids, and β-hydroxybutyrate concentrations. Adipose tissue was analyzed for INSR and GLUT4 mRNA and protein concentrations. During the glucose tolerance test 0.15 g/kg of body weight glucose was infused; blood was collected at -5, 5, 10, 20, 30, 40, 50, and 60 min, and analyzed for glucose and insulin. On d -21 the area under the curve (AUC) of glucose was smallest in group T (1,512 ± 33.9 mg/dL × min) and largest in group OC (1,783 ± 33.9 mg/dL × min), and different between all groups. Basal insulin on d -21 was lowest in group T (13.9 ± 2.32 µU/mL), which was different from group OC (24.9 ± 2.32 µU/mL. On d -21 the smallest AUC 5-60 of insulin in group T (5,308 ± 1,214 µU/mL × min) differed from the largest AUC in group OC (10,867 ± 1,215 µU/mL × min). Time to reach basal concentration of insulin in group OC (113 ± 14.1 min) was longer compared with group T (45 ± 14.1). The INSR mRNA abundance on d 21 was higher compared with d -21 in groups T (d -21: 3.3 ± 0.44; d 21: 5.9 ± 0.44) and O (d -21: 3.7 ± 0.45; d 21: 4.7 ± 0.45). The extent of INSR protein expression on d -21 was highest in group T (7.3 ± 0.74 ng/mL), differing from group O (4.6 ± 0.73 ng/mL), which had the lowest expression. The amount of GLUT4 protein on d -21 was lowest in group OC (1.2 ± 0.14 ng/mL), different from group O (1.8 ± 0.14 ng/mL), which had the highest amount, and from group T (1.5 ± 0.14 ng/mL). From d -21 to 21, a decrease occurred in the GLUT4 protein levels in both groups T (d -21: 1.5 ± 0.14 ng/mL; d 21: 0.8 ± 0.14 ng/mL) and O (d -21: 1.8 ± 0.14 ng/mL; d 21: 0.8 ± 0.14 ng/mL). These results demonstrate that in obese cows adipose tissue insulin resistance develops prepartum and is related to reduced GLUT4 protein synthesis. Regarding glucose metabolism, body condition did not affect adipose tissue insulin resistance postpartum.

Breathomics--exhaled volatile organic compound analysis to detect hepatic encephalopathy: a pilot study

The current diagnostic challenge with diagnosing hepatic encephalopathy (HE) is identifying those with minimal HE as opposed to the more clinically apparent covert/overt HE. Rifaximin, is an effective therapy but earlier identification and treatment of HE could prevent liver disease progression and hospitalization. Our pilot study aimed to analyse breath samples of patients with different HE grades, and controls, using a portable electronic (e) nose. 42 patients were enrolled; 22 with HE and 20 controls. Bedside breath samples were captured and analysed using an uvFAIMS machine (portable e-nose). West Haven criteria applied and MELD scores calculated. We classify HE patients from controls with a sensitivity and specificity of 0.88 (0.73-0.95) and 0.68 (0.51-0.81) respectively, AUROC 0.84 (0.75-0.93). Minimal HE was distinguishable from covert/overt HE with sensitivity of 0.79 and specificity of 0.5, AUROC 0.71 (0.57-0.84). This pilot study has highlighted the potential of breathomics to identify VOCs signatures in HE patients for diagnostic purposes. Importantly this was performed utilizing a non-invasive, portable bedside device and holds potential for future early HE diagnosis.

Targeting type Iγ phosphatidylinositol phosphate kinase inhibits breast cancer metastasis

Most deaths from breast cancer are caused by metastasis, a complex behavior of cancer cells involving migration, invasion, survival, and microenvironment manipulation. Type Iγ phosphatidylinositol phosphate kinase (PIPKIγ) regulates focal adhesion assembly, and its phosphorylation at Y639 is critical for cell migration induced by EGF. However, the role of this lipid kinase in tumor metastasis remains unclear. Here we report that PIPKIγ is vital for breast cancer metastasis. Y639 of PIPKIγ can be phosphorylated by stimulation of EGF and hepatocyte growth factor (HGF), two promoting factors for breast cancer progression. Histological analysis revealed elevated Y639-phosphorylation of PIPKIγ in invasive ductal carcinoma lesions and suggested a positive correlation with tumor grade. Orthotopically transplanted, PIPKIγ-depleted breast cancer cells showed substantially reduced growth and metastasis, as well as suppressed expression of multiple genes related to cell migration and microenvironment manipulation. Re-expression of wild-type PIPKIγ in PIPKIγ-depleted cells restored tumor growth and metastasis, reinforcing the importance of PIPKIγ in breast cancer progression. Y639-to-F or a kinase-dead mutant of PIPKIγ could not recover the diminished metastasis in PIPKIγ-depleted cancer cells, suggesting that Y639 phosphorylation and lipid kinase activity are both required for development of metastasis. Further analysis with in vitro assays indicated that depleting PIPKIγ inhibited cell proliferation, MMP9 secretion, and cell migration and invasion, lending molecular mechanisms for the eliminated cancer progression. These results suggest that PIPKIγ, downstream of EGF and/or HGF receptor, participates in breast cancer progression from multiple aspects and deserves further studies to explore its potential as a therapeutic target.

Curative effect of combined lamivudine, adefovir dipivoxil, and stem cell transplantation on decompensated hepatitis B cirrhosis

This study assessed the clinical efficacy of lamivudine and adefovir dipivoxil combined with autologous bone marrow stem cell transplantation as treatment for patients with hepatitis B and decompensated liver cirrhosis. In total, 77 patients with hepatitis B and decompensated liver cirrhosis were randomly divided into two groups. Under general symptomatic and supportive treatment, the patients in group A (37 cases) were treated with lamivudine and adefovir dipivoxil, whereas those in group B (40 cases) were treated with autologous bone marrow stem cell transplantation in combination with lamivudine and adefovir dipivoxil. After 4 weeks of treatment, the liver function indicators and clinical signs and symptoms of the patients in group B improved more significantly than those of patients in group A. Lamivudine and adefovir dipivoxil in combination with autologous bone marrow stem cell transplantation effectively prevented hepatitis B virus infection and bone marrow stem cell damage. This combination treatment facilitates the differentiation of bone marrow stem cells into normal liver cells to restore liver structure and improve liver function, thereby improving the quality of life of patients.

Alterations in milk and blood metabolomes during the first months of lactation in dairy cows

The molecular composition of milk is influenced by various genetic and environmental factors. Time is one important factor, and the fact that certain milk components change over the course of lactation is widely accepted. Untargeted global metabolomics is an approach to study hundreds of low molecular weight compounds simultaneously. In this study, mass spectrometry-based global metabolomics was used to follow the course of changes in milk (n=133) and blood plasma (n=133) during the early stage of lactation. Little correlation was found between the molecular composition of blood plasma and milk. Blood showed a higher dependence on animal individuality than did milk, in which common evolutions in time resolved. Citrate and lactose had the greatest effect on these changes; however, the most significant changes in milk during the first months of lactation were associated with phosphorylated saccharide levels, whereas the most significant changes in blood plasma were associated with levels of polyunsaturated fatty acids containing phosphatidylcholine. In conclusion, a new systemic approach was used to search for minor metabolites whose concentrations were significantly altered in milk and blood during the first months of lactation.

Field trial on the relationship of blood metabolites and body condition score with the recurrence of luteal activity in Estonian Holstein cows

Associations of body condition scores and blood metabolites, measured before calving and at different periods during early lactation, with recurrence of luteal activity were investigated in a 250-head commercial dairy farm during a 4-year period (1999-2002). The study was conducted on 48 dairy cows (60 lactations) with average 305-day milk yield of 8149 kg per cow. Blood samples taken 1-14 days before calving and 1-14, 28-42 and 63-77 days after calving were analysed for aspartate aminotransferase, glucose, ketone bodies, triglycerides, non-esterified fatty acids and cholesterol. Milk progesterone (P(4)) profiles (samples collected twice a week, P(4) levels measured in whole milk by enzyme immunoassay) were used to evaluate the interval from calving to first luteal response, P(4) >5 ng/ml, and the interval from calving to first normal cycle. The MIXED procedure of the sas system was used to study the association of investigated parameters. A higher concentration of ketone bodies before calving was associated with shorter interval to recurrence of first normal cycle (P = 0.007) and tended to be related to shorter interval from calving to first luteal response (P = 0.071). A lower prepartum aminotransferase activity showed a tendency to be associated with shorter interval from calving to first luteal response (P = 0.084). Results suggest metabolic status up to 2 weeks prepartum to be related to the resumption of postpartum luteal activity in Estonian Holstein dairy cows.

Phosphatidylinositol-4,5 bisphosphate produced by PIP5KIgamma regulates gelsolin, actin assembly, and adhesion strength of N-cadherin junctions

Phosphoinositides regulate several actin-binding proteins but their role at intercellular adhesions has not been defined. We found that phosphatidylinositol 4,5-bisphosphate (PI(4,5)P2) was generated at sites of N-cadherin-mediated intercellular adhesion and was a critical regulator of intercellular adhesion strength. Immunostaining for PI(4,5)P2 or transfection with GFP-PH-PLCdelta showed that PI(4,5)P2 was enriched at sites of N-cadherin adhesions and this enrichment required activated Rac1. Isoform-specific immunostaining for type I phosphatidylinositol 4-phosphate 5 kinase (PIP5KI) showed that PIP5KIgamma was spatially associated with N-cadherin-Fc beads. Association of PIP5KIgamma with N-cadherin adhesions was in part dependent on the activation of RhoA. Transfection with catalytically inactive PIP5KIgamma blocked the enrichment of PI(4,5)P2 around beads. Catalytically inactive PIP5KIgamma or a cell-permeant peptide that mimics and competes for the PI(4,5)P2-binding region of the actin-binding protein gelsolin inhibited incorporation of actin monomers in response to N-cadherin ligation and reduced intercellular adhesion strength by more than twofold. Gelsolin null fibroblasts transfected with a gelsolin severing mutant containing an intact PI(4,5)P2 binding region, demonstrated intercellular adhesion strength similar to wild-type transfected controls. We conclude that PIP5KIgamma-mediated generation of PI(4,5)P2 at sites of N-cadherin contacts regulates intercellular adhesion strength, an effect due in part to PI(4,5)P2-mediated regulation of gelsolin.

Molecular analysis for new kinase mutations in imatinib resistant gastrointestinal stromal tumor patients

4155

Background: Gastrointestinal stromal tumors (GISTs) are characterized by expression of activated mutation of KIT or platelet-derived growth factor receptor alpha (PDGFRA). Imatinib had now been widespread used for treatment of unresectable or metastatic GISTs. However, most patients developed resistant to imatinib in a period of 1∼2 years. We have recently found the resistance to imatinib in GIST might be related to additional mutations in the kinase domain and we intend to identify the secondary mutation in imatinib resistant GISTs in Taiwanese patients. Patients and Methods: From April 2001 to November 2005, 20 advanced GIST patients were treated in Taipei MMH. Within 32 months, 10 patients with initial near-complete response to imatinib developed disease progression and resistant to imatinib. Nine harbored mutations in KIT exon 11, and one harbored mutation in KIT exon 9 before imatinib treatment. Five patients expired and the other (residual) five patients received excision or biopsy of progression lesions. Genomic DNA extracted from paraffin-embedded specimens from alive patients, were analyzed by sequencing for KIT (exon 9, 11, 13, 17) and PDGFRA (exon 10, 12 14, 18) gene mutation. Results: Molecular analysis revealed two patients harbored KIT exon 13 mutation Val654Ala substitution in their progression lesion. The other three patients harbored KIT exon 17 mutation Asn822Lys substitution. Conclusion: The novel missense mutation of KIT exon 17 N822K has never been reported before. The finding of an association between new mutation and disease progression is very impressive. The relationship between secondary mutation in these kinases and clinical response to imatinib will require further investigation.

No significant financial relationships to disclose.

Direct binding of beta-arrestins to two distinct intracellular domains of the delta opioid receptor

beta-Arrestins regulate opioid receptor-mediated signal transduction and play an important role in opiate-induced analgesia and tolerance/dependence. This study was carried out to measure the direct interaction between beta-arrestins and opioid receptor. Immunoprecipitation experiments demonstrated that beta-arrestin 1 physically interacts with delta opioid receptor (DOR) co-expressed in human embryonic kidney 293 cells in an agonist-enhanced manner and truncation of the carboxyl terminus of DOR partially impairs the interaction. In vitro data from glutathione-S-transferase pull-down assay showed that the carboxyl terminus (CT) and the third intracellular loop (I3L) of DOR are both capable of and either domain is sufficient for binding to beta-arrestin 1 and 2. Surface plasmon resonance determination further revealed that binding of CT and I3L of DOR to beta-arrestin is additive, suggesting these two domains bind at distinctly different sites on beta-arrestin without considerable spatial hindrance. This study demonstrated for the first time the direct binding of beta-arrestins to the two distinct domains, the carboxyl terminus and the third intracellular loop, of DOR.

Identification of a human brain-specific isoform of mammalian STE20-like kinase 3 that is regulated by cAMP-dependent protein kinase

A novel isoform of mammalian STE20-like kinase 3 (MST3) with a different 5' coding region from MST3, termed MST3b, was identified by searching through expressed sequence tag data base and obtained by rapid amplification of cDNA 5'-ends. MST3b was assigned to the long arm of human chromosome 13, D13S159-D13S280, by use of the National Center for Biotechnology Information sequence-tagged sites data base. Reverse transcription-polymerase chain reaction and Northern blot analysis with a probe derived from 5' distinct sequence of MST3b revealed that the expression of MST3b mRNA is restricted to the brain, in contrast to ubiquitous distribution of MST3 transcript. Western analysis confirmed the brain-specific expression of MST3b protein. In situ hybridization of rat brain sections with a MST3b-specific probe indicated that MST3b is widely expressed in different brain regions, with especially high expression in hippocampus and cerebral cortex. When expressed in human embryonic kidney 293 (HEK293) cells, MST3b effectively phosphorylated myelin basic protein, as well as undergoing autophosphorylation. Interestingly, expression of MST3, but not MST3b, in HEK293 cells was able to activate the endogenous p42/44 mitogen-activated protein kinase (MAPK) up to 4-fold, whereas neither isoform activated p38 MAPK under the same conditions. Further experiments demonstrated that MST3b, but not MST3, was effectively phosphorylated by activation of cyclic AMP-dependent protein kinase (PKA) in both in vivo and in vitro assays. The mutation of Thr-18 into Ala in MST3b (T18A), a putative PKA phosphorylation site that is absent in MST3, abolished its phosphorylation by PKA. Consequently, expression of the T18A mutant in HEK293 cells led to partial activation of p42/44 MAPK, indicating that MST3b is under the regulation of PKA. Taken together, our data provide evidence that the two isoforms of STE20-like kinase 3 are differentially distributed and regulated.

Five-transmembrane domains appear sufficient for a G protein-coupled receptor: functional five-transmembrane domain chemokine receptors

The putative seven-transmembrane (TM) domains have been the structural hallmark for the superfamily of heterotrimeric G protein-coupled receptors (GPCRs) that regulate a variety of cellular functions by mediating a large number of extracellular signals. Five-TM GPCR mutants of chemokine receptor CCR5 and CXCR4, the N-terminal segment of which connected directly to TM3 as a result of a deletion of TM1-2 and the first intracellular and extracellular loops, have been obtained in this study. Laser confocal microscopy and flow cytometry analysis revealed that these five-TM mutant GPCRs were expressed stably on the cell surface after transfection into human embryonic kidney 293 cells. The five-TM CCR5 and CXCR4 functioned as normal chemokine receptors in mediating chemokine-stimulated chemotaxis, Ca2+ influx, and activation of pertussis toxin-sensitive G proteins. Like the wild-type GPCRs, the five-TM mutant receptors also underwent agonist-dependent internalization and desensitization and were subjected to regulation by GPCR kinases and arrestins. Our study indicates that five-TM domains, at least in the case of CCR5 and CXCR4, appear to meet the minimum structural requirements for a functional GPCR and suggests possible existence of functional five-TM GPCRs in nature during evolution.

Anti-HIV agent trichosanthin enhances the capabilities of chemokines to stimulate chemotaxis and G protein activation, and this is mediated through interaction of trichosanthin and chemokine receptors

Trichosanthin (TCS), an active protein component isolated from a traditional Chinese medicinal herb Trichosanthes kirilowii, has been shown to inhibit HIV infection and has been applied in clinical treatment of AIDS. The recent development that chemokines and chemokine receptors play important roles in HIV infection led us to investigate the possible functional interaction of TCS with chemokines and their receptors. This study demonstrated that TCS greatly enhanced both RANTES (regulated upon activation, normal T cell expressed and secreted)- and stromal cell-derived factor (SDF)-1 alpha-stimulated chemotaxis (EC50 approximately equal to 1 nM) in leukocytes (THP-1, Jurkat, and peripheral blood lymphocyte cells) and activation of pertussis toxin-sensitive G proteins (EC50 approximately equal to 20 nM). TCS also significantly augmented chemokine-stimulated activation of chemokine receptors CCR5 and CXCR4 as well as CCR1, CCR2B, CCR3, and CCR4 transiently expressed in HEK293 cells. A mutant TCS with 4,000-fold lower ribosome-inactivating activity showed similar augmentation activity as wild-type TCS. Moreover, flow cytometry demonstrated that the specific association of TCS to the cell membranes required the presence of chemokine receptors, and laser confocal microscopy reveals that TCS was colocalized with chemokine receptors on the membranes. The results from TCS-Sepharose pull-down and TCS and chemokine receptor coimmunoprecipitation and cross-linking experiments demonstrated association of TCS with CCR5. Thus, our data clearly demonstrated that TCS synergizes activities of chemokines to stimulate chemotaxis and G protein activation, and the effects of TCS are likely to be mediated through its interaction with chemokine receptors.

Differential neurotoxicity of etorphine-like opiates: lack of correlation with their ability to activate opiate receptors

The present study was undertaken to compare the neurotoxic effects of three etorphine-like opiates (etorphine, dihydroetorphine, and another derivative of oripavine) and heroin with their ability to activate opiate receptors in human neuroblastoma cell line SK-N-SH as well as in two other neuronal cell lines. Neurotoxicity was measured by using [3H]-thymidine incorporation analysis, cell viability measurement and Cytosensor microphysiometry. It was found that, in spite of the very similar molecular structures of these opiates, they displayed significant differences in cytotoxicity, with etorphine and another derivative of oripavine possessing high potency but dihydroetorphine and heroin little effect. However, neurotoxic potency of the opiates was not directly correlated to their ability to activate opioid receptors, as determined by [35S]-guanylyl-5'-O-(gamma-tho)-triphosphate binding assay. These findings provide clear evidence of differential neurotoxicity of etorphine-like opiates, and suggest that the neurotoxicity is not closely related to the molecular configuration required as opioid receptor agonist but is probably associated with the presence of a double bond in the structure.

Differential efficacies of kappa agonists to induce homologous desensitization of human kappa opioid receptor

The efficacies of different K agonists to activate K opioid receptor (kappaOR) and to induce acute homologous desensitization of kappaOR-mediated extracellular acidification response (ECAR) have been investigated using microphysiometry in Chinese hamster ovary (CHO) cells stably expressing kappaOR. Although efficacy of dynorphin A (DA) to stimulate kappaOR-mediated ECAR was comparable to that of U69593, DA displayed a significant higher efficacy to induce desensitization of kappaOR. Moreover, the half life for the recovery of kappaOR responsiveness after DA prechallenge was four times longer than those observed after U69593 or etorphine pretreatment. In contrast, the efficacy of DA to stimulate and desensitize mu opioid receptors (muOR) stably expressed in CHO cells were comparable to those of other mu agonists.

Nociceptin/orphanin FQ stimulates extracellular acidification and desensitization of the response involves protein kinase C

A Chinese hamster ovary (CHO) cell line, CHO-ORL1, stably expressing human opioid receptor-like receptor 1 (ORL1) has been used to determine ORL1-mediated signaling events using microphysiometry. Nociceptin/orphanin FQ (N/OFQ), a specific endogenous agonist of ORL1, induced an increase in extracellular acidification rate (ECAR) in CHO-ORL1 cells. The ECAR response stimulated by N/OFQ was concentration-dependent and pertussis toxin-sensitive. Repeated exposures of the cells to N/OFQ caused desensitization of ORL1. The ECAR response was recovered at the half-life of approximately 12 min after the initial challenge. Pretreatment with inhibitor of cAMP-dependent kinase did not affect desensitization of ORL1. However, specific inhibitors for protein kinase C almost abolished N/OFQ-induced desensitization of extracellular acidification responsiveness, indicating the involvement of protein kinase C in the process.

Molecular characterization and functional expression of opioid receptor-like1 receptor

The opioid receptor-like1 receptor (ORL1), an orphan receptor whose human and murine complementary DNAs, has been characterized recently. ORL1 transcripts are particularly abundant in the central nervous system. We demonstrated that ORL1 expressed in human neuroblastoma SK-N-SH and SH-SY5Y cell lines by radioligand binding assay, reverse transcription polymerase chain reaction (RT-PCR) and Northern analysis in the present study. Stimulation with ORL1 specific agonist, nociceptin/orphanin FQ, increased [35S]GTP gamma S binding to SK-N-SH cell membranes (EC50 = 14 +/- 0.45 nM), and attenuated forskolin-stimulated accumulation of cellular cAMP (EC50 = 0.80 +/- 0.45 nM), indicative that activation of ORL1 activates G proteins and inhibits adenylyl cyclase. Activation of ORL1 receptor was also accessed using CHO:hORL1 cell line by microphysiometer. Treatment of nociceptin/orphanin FQ increased extracellular acidification rate significantly.

The selenium status of dairy cattle in Estonia

The concentration of selenium in soils and crops varies widely in different parts of the world. The selenium status of many countries is unknown, but there is evidence that selenium deficient crops occur in every continent. Surveys in Finland (Oksanen & Sandholm 1970), Norway (Mikkelsen & Aas Hansen 1967), Denmark (Gissel-Nielsen 1975) and Sweden (Lind-berg & Bingefors 1970) were among the first to investigate selenium status and they showed that each of these countries was very deficient. As a result selenium was permitted to be included as a supplement in animal feeds, in Finland from 1969, in Denmark from 1975, and in Norway and Sweden from 1980.

Differential response of the Ras exchange factor, Ras-GRF to tyrosine kinase and G protein mediated signals

Ras-GRF, a guanine-nucleotide exchange factor that activates Ras p21, was tested for its ability to couple to either tyrosine kinase or heterotrimeric G protein signal transduction pathways. Ras-GRF failed to bind the SH2 and SH3 containing adaptor protein Grb2, either in vitro or in vivo. Furthermore, Ras-GRF did not form a stable complex with activated EGF receptor. However, as has been shown previously (Cen et al., 1994), the presence of Ras-GRF in NIH3T3 cells enhanced the activation of Ras induced by serum stimulation. A similar effect was not observed with PDGF stimulation. Moreover, serum stimulation lead to the hyperphosphorylation of Ras-GRF. Both the serum induced super-activation of Ras, and the hyperphosphorylation of Ras-GRF were blocked by pretreatment of cells with the Gi,o inhibitor pertussis toxin, but not by pretreatment with the tyrosine kinase inhibitor genistein. These results suggest that Ras-GRF has the capacity to mediate Ras activation initiated by signals using heterotrimeric G proteins.

Protection against detrimental effects of potyvirus infection in transgenic tobacco plants expressing the papaya ringspot virus coat protein gene

We obtained transgenic tobacco plants expressing the papaya ringspot virus (PRV) coat protein (CP) gene by transformation via Agrobacterium tumefaciens. Expression was effectively monitored by enzyme-linked immunosorbent assays (ELISA) of crude tissue extracts. Subcloned plants derived from eight original Ro transformants were inoculated with potyviruses: tobacco etch (TEV), potato virus Y (PVY), and pepper mottle (PeMV). Plants that accumulated detectable levels of the PRV CP showed significant delay in symptom development and the symptoms were attenuated. Similar results were obtained with inoculated R1 plants. We conclude that the expression of the PRV CP-gene imparts protection against infection by a broad spectrum of potyviruses.

[Carcinoembryonic antigen and immunoglobin in gastric juice in the diagnosis of gastric cancer]

Levels of carcinoembryonic antigen (CEA) and immunoglobin (Ig) in gastric juice of 93 patients with benign and malignant gastric diseases were assayed. The CEA level in gastric cancer patients (55.73 +/- 38.26 ng/ml) was obviously higher than that in peptic ulcer (15.51 +/- 12.09 ng/ml) and superficial gastritis (26.96 +/- 20.17 ng/ml). But no significant difference was found between the CEA levels of gastric cancer and chronic atrophic gastritis (48.66 +/- 31.87 ng/ml). Also, elevated CEA was closely correlated to intestinal metaplasia. The positive rate of Ig was significantly higher in gastric cancer (IgG greater than or equal to 185 ug/ml, IgA greater than or equal to 100 ug/ml) than in benign gastric diseases. Although no correlation is present in the CEA and Ig in gastric juice, the combination of these two methods could improve the diagnostic accuracy. We believe that the two assays are worthy for screening gastric cancer from patients with high risk, and for identifying precancerous lesions.