Research trends of Janus Kinase inhibitors: a bibliometric and visualized study from 2012 to 2023

OBJECTIVE

Janus Kinase (JAK) inhibitors have been extensively evaluated for their potential in the management of various diseases. Despite previous research on this topic, there is a lack of bibliometric analysis that summarizes research trends on JAK inhibitors. This study aims to provide a comprehensive overview of the top 100 most frequently cited studies on JAK inhibitors over the last ten years.

MATERIALS AND METHODS

The Web of Science database was used to screen and extract relevant studies on JAK inhibitors. The top 100 studies most cited within the JAK inhibitor-related research were identified and evaluated, and various data such as the year of publication, study focus and keywords, author information, and number of citations were extracted and analyzed for further examination.

RESULTS

In the top 100 most cited studies of JAK inhibitors, more than 70% of studies focused on the role of JAK inhibitors in disease treatments, with 42% of these studies focused on using JAK inhibitors as treatment for autoimmune diseases and 19 of them focused on the treatment of neoplasms. Time trend analysis revealed that the keywords "tofacitinib", "atopic dermatitis", and "rheumatoid arthritis" were widely mentioned in 2016, while new trends emerged in 2018, with "ruxolitinib" and "baricitinib" being more commonly mentioned.

CONCLUSIONS

The top 100 most frequently cited studies on JAK inhibitors focused primarily on the safety and efficacy of these inhibitors in the management of various diseases, particularly inflammatory diseases and neoplasms. The results can serve as a valuable reference for rheumatologists and immunologists interested in the development of JAK inhibitors and expanding future research fields.

Randomized trial of oral versus enteral feeding for patients with postoperative pancreatic fistula after pancreatoduodenectomy

BACKGROUND

Whether continued oral feeding may have a negative impact on healing of postoperative pancreatic fistula (POPF) is unclear. The aim was to test the hypothesis that oral feeding is non-inferior to enteral feeding in closure of POPF after pancreatoduodenectomy, and to clarify the effects of oral feeding on the duration and grade of POPF.

METHODS

This multicentre, non-inferiority randomized trial of oral or enteral feeding of patients with POPF after pancreatoduodenectomy recruited patients between August 2013 and September 2016. The primary efficacy outcome was the 30-day fistula closure rate. The prespecified non-inferiority margin was 15 per cent. Other efficacy outcomes included grade of fistula, and hospital stay and costs.

RESULTS

A total of 114 patients were included, and received oral (57) or enteral (57) feeding. The two groups were balanced in baseline characteristics and no patient was lost to follow-up. In intention-to-treat analysis, oral feeding was non-inferior to enteral feeding in terms of 30-day fistula closure rate (88 versus 89 per cent respectively; difference -1·8 per cent, lower limit of 95 per cent c.i. -14·4 per cent; P = 0·020 for non-inferiority). Compared with enteral feeding, oral feeding significantly reduced hospital costs and duration of stay. No significant differences were noted in the number of patients whose POPF evolved into grade B/C, or other outcomes.

CONCLUSION

Oral feeding in patients with POPF after pancreatoduodenectomy did not increase the duration or grade of POPF, and was associated with reduced duration of stay and hospital costs. Registration number: NCT01755260 (http://www.clinicaltrials.gov).

Ca2+ movement and cytotoxicity induced by the pyrethroid pesticide bifenthrin in human prostate cancer cells

Bifenthrin, a commonly used pyrethroid pesticide, evokes various toxicological effects in different models. However, the effect of bifenthrin on cytosolic-free Ca2+ level ([Ca2+] i) and cytotoxicity in human prostate cancer cells is unclear. This study examined whether bifenthrin altered Ca2+ homeostasis and cell viability in PC3 human prostate cancer cells. [Ca2+] i in suspended cells were measured using the fluorescent Ca2+-sensitive dye fura-2. Cell viability was examined by 4-[3-[4-lodophenyl]-2-4(4-nitrophenyl)-2H-5-tetrazolio-1,3-benzene disulfonate] water soluble tetrazolium-1 assay. Bifenthrin (100–400 μM) concentration-dependently induced [Ca2+] i rises. Ca2+ removal reduced the signal by approximately 30%. In Ca2+-free medium, treatment with the endoplasmic reticulum Ca2+ pump inhibitor 2,5-di-tert-butylhydroquinone (BHQ) abolished bifenthrin-evoked [Ca2+] i rises. Conversely, treatment with bifenthrin abolished BHQ-evoked [Ca2+] i rises. Inhibition of phospholipase C (PLC) with U73122 significantly inhibited bifenthrin-induced [Ca2+] i rises. Mn2+ has been shown to enter cells through similar mechanisms as Ca2+ but quenches fura-2 fluorescence at all excitation wavelengths. Bifenthrin (400 μM)-induced Mn2+ influx implicates that Ca2+ entry occurred. Bifenthrin-induced Ca2+ entry was inhibited by 30% by protein kinase C (PKC) activator (phorbol 12-myristate 13 acetate) and inhibitor (GF109203X) and three inhibitors of store-operated Ca2+ channels: nifedipine, econazole, and SKF96365. Bifenthrin at 175–275 μM decreased cell viability, which was not reversed by pretreatment with the Ca2+ chelator 1,2-bis(2-aminophenoxy) ethane- N, N, N′, N′-tetra acetic acid-acetoxymethyl ester. Together, in PC3 cells, bifenthrin-induced [Ca2+] i rises by evoking PLC-dependent Ca2+ release from the endoplasmic reticulum and Ca2+ entry via PKC-sensitive store-operated Ca2+ entry. Bifenthrin also caused Ca2+-independent cell death.

Horizontal root fractures in posterior teeth without dental trauma: tooth/root distribution and clinical characteristics

AIM

To describe the clinical characteristics and radiographic findings of horizontal root fractures (HRF) in posterior teeth without a history of dental trauma.

METHODOLOGY

A total 24 patients and 31 HRF cases in 28 posterior teeth were collected from 2006 to 2015. Clinical examinations and radiographic imaging were evaluated. Value of confidence intervals of the proportions was calculated for data presentation.

RESULTS

The number of males (54%) was similar to females (46%). The patients were predominantly between 50 and 70 years of age (75%). Most HRF cases were found in nonendodontically treated teeth (79%), without crown and bridge restorations (82%), and maxillary molars (54%). Many roots of maxillary molars had developed HRF, and the probability was nearly equal. Fractured teeth usually presented with periodontal and apical bone loss, and most patients (92%) were diagnosed with full mouth chronic periodontitis. Tooth wear was another common clinical feature amongst these patients.

CONCLUSIONS

HRF in posterior teeth without dental trauma occurred mainly in patients aged between 50 and 70, in nonendodontically treated teeth, teeth with attrition but without crown and bridge restorations, maxillary molars and with periodontal and periapical bony destruction. Periodontal condition, occlusal wear and patients' age at diagnosis were the possible related factors. HRF in posterior teeth without dental trauma is a diagnostic challenge and even misdiagnosed. A thorough clinical examination, radiographic analysis and recognition of the clinical characteristics are helpful in the early diagnosis and treatment of HRF.

Cubic three-dimensional hybrid silica solids for nuclear hyperpolarization

Porous network architecture of hybrid silicas containing TEMPO radicals along their pores is key for increased hyperpolarization performances.

Hyperpolarization of metabolites by dissolution dynamic nuclear polarization (D-DNP) for MRI applications often requires fast and efficient removal of the radicals (polarizing agents). Ordered mesoporous SBA-15 silica materials containing homogeneously dispersed radicals, referred to as HYperPolarizing SOlids (HYPSOs), enable high polarization – P(¹H) = 50% at 1.2 K – and straightforward separation of the polarizing HYPSO material from the hyperpolarized solution by filtration. However, the one-dimensional tubular pores of SBA-15 type materials are not ideal for nuclear spin diffusion, which may limit efficient polarization. Here, we develop a generation of hyperpolarizing solids based on a SBA-16 structure with a network of pores interconnected in three dimensions, which allows a significant increase of polarization, i.e. P(¹H) = 63% at 1.2 K. This result illustrates how one can improve materials by combining a control of the incorporation of radicals with a better design of the porous network structures.

Chronic obstructive pulmonary disease and allied conditions is a strong independent risk factor for osteoporosis and pathologic fractures: a population-based cohort study

BACKGROUND

Chronic obstructive pulmonary disease and allied conditions (COPD) is frequently associated with various comorbidities. This study examined the association between osteoporosis and pathologic fractures in a sample of patients with COPD.

METHODS

In this cohort study, claims data from the National Health Insurance Research Database of Taiwan were used to evaluate the risk between COPD and osteoporosis. Using data from the Longitudinal Health Insurance Database 2000, we conducted a retrospective cohort study by investigating patients aged 20 years and older who were newly diagnosed with COPD and comparing them with controls without COPD during 2000-2010. In addition, we used univariable and multivariable Cox proportional hazards regression models to measure the association between COPD and the risk of osteoporosis.

RESULTS

Our results revealed that COPD was significantly associated with a high risk of osteoporosis, regardless of whether the patients with COPD were corticosteroid users and irrespective of age and sex. After adjustment for covariates, the COPD patients exhibited a 1.54-fold higher risk of developing osteoporosis (hazard ratio 1.54, 95% confidence interval 1.44-1.64). COPD was a stronger risk factor for osteoporosis in men. Moreover, patients with severe COPD had a higher risk of osteoporosis or pathologic fractures.

CONCLUSION

This study revealed that COPD, which shares the characteristics of inflammatory diseases, is associated with a higher risk of osteoporosis after adjustment for comorbidities.

Providing instrumental social support is more beneficial to reduce mortality risk among the elderly with low educational level in Taiwan: a 12-year follow-up national longitudinal study

BACKGROUND

To evaluate whether the effects of providing or receiving social support are more beneficial to reduce mortality risk among the elderly with different educational levels.

METHODS

In this long-term prospective cohort study, data were retrieved from the Taiwan Longitudinal Study on Aging. This study was initiated from 1996 until 2007. The complete data from 1492 males and 1177 females aged ≥67 years were retrieved. Participants received financial, instrumental, and emotional support, and they actively provided instrumental and emotional support to others and involved in social engagement. Education attainment was divided into two levels: high and low. The low education level included illiterate and elementary school. The high education level included junior high school to senior high school and above college. Cox regression analysis was used to examine the association between providing or receiving social support on mortality with different educational levels.

RESULTS

The average age of the participants in 1996 was 73.0 (IQR=8.0) years, and the median survival following years (1996-2007) of participants was 10.3 (IQR=6.7) years. Most participants were low educational level including illiterate (39.3%) and elementary school (41.2%). Participants with high educational level tend to be younger and more male significantly. On the contrary, participants with low educational level tend to have significant more poor income, more depression, more cognition impairment, more with IADL and ADL disability than high educational level. Most participants received instrumental support from others (95.5%) and also provided emotional support to others (97.7%). Providing instrumental support can reduce 17% of mortality risk among the elderly with a low level of education after adjusting several covariates [Hazard ratio (HR) = 0.83; 95% confidence interval (CI) = 0.70-0.99; p = 0.036].

CONCLUSIONS

Providing instrumental social support to others confer benefits to the giver and prolong life expectancy among the elderly with low educational levels.

Association between psoriasis and asthma: a population-based retrospective cohort analysis

BACKGROUND

Both psoriasis and asthma are chronic immune-mediated inflammatory diseases.

OBJECTIVES

To evaluate the risk of developing asthma in patients with psoriasis compared with controls.

METHODS

This cohort study was conducted using data from the Taiwan National Health Insurance Research Database. Patients with psoriasis (n = 10,288) and matched comparison patients without psoriasis (n = 41,152) were evaluated. A Cox proportional hazard regression analysis was used to determine the risk of asthma in patients with and without psoriasis.

RESULTS

The risk of asthma was 1·38-fold higher [95% confidence interval (CI) 1·23-1·54] in the cohort with psoriasis than in the reference cohort, after adjusting for age, sex and comorbidities. The incidence of asthma in men and women with psoriasis exhibited nonsignificant differences. Among all patients aged > 50 years, psoriasis was associated with a higher risk of asthma compared with not having psoriasis [adjusted hazard ratio (HR) 1·49; 95% CI 1·18-1·88 (in patients aged 50-64 years); adjusted HR 1·63; 95% CI 1·34-1·99 (in patients aged > 65 years)].

CONCLUSIONS

Our results indicate that patients with psoriasis are associated with a increased risk of developing asthma.

β-1,4-Galactosyltransferase III suppresses extravillous trophoblast invasion through modifying β1-integrin glycosylation

INTRODUCTION

Glycosylation controls diverse protein functions and regulates various cellular phenotypes. Trophoblast invasion is essential for normal placental development. However, the role of glycosylation in human placenta throughout pregnancy is still unclear. The β-1,4-galactosyltransferase III (B4GALT3) has been found to regulate cancer cell invasion. We therefore investigated the expression of B4GALT3 in placenta and its roles in trophoblast.

METHODS

B4GALT3 protein expression was examined by quantitative Western blotting analysis in human placentas. For identification of B4GALT3-positive cells in normal human placenta, immunohistochemistry and immunofluorescence methods were used. To investigate effects of B4GALT3 on extravillous trophoblast (EVT)-like cell and primary EVT cells, we analyzed cell growth, adhesion, migration, and invasion in mock and B4GALT3-transfected cell.

RESULTS

B4GALT3 expression significantly increased in third trimester human placenta. Immunostaining revealed that B4GALT3 expressed in placental villous cytotrophoblast, syncytiotrophoblast, and a subpopulation of EVT cells throughout pregnancy. Interestingly, we found increases in the expression level and percentage of B4GALT3-positive cells in third trimester EVT, but not in syncytiotrophoblasts and cytotrophoblasts of placental villi. Overexpression of B4GALT3 in HTR8/SVneo cells and primary trophoblast cells significantly suppressed cell migration. In addition, B4GALT3 suppressed cell invasion, and enhanced cell adhesion to laminin in HTR8/SVneo cells. Notably, we found that B4GALT3 modified glycans on β1-integrin, suppressed focal adhesion kinase (FAK) signaling, and enhanced β1-integrin degradation.

DISCUSSION

We propose that B4GALT3-mediated glycosylation change not only enhances β1-integrin binding to laminin, but also attenuates β1-integrin stability. Our findings suggest that B4GALT3 is a critical regulator for suppressing EVT invasion in the late stages of pregnancy.

The association between chronic obstructive pulmonary disease and Parkinson's disease: a nationwide population-based retrospective cohort study

OBJECTIVE

Previous research has shown that patients with chronic obstructive pulmonary disease (COPD) tend to have a higher risk for cognitive impairment and dementia, a neurodegenerative disorder. The goal of this study was to examine what relationship, if any, exists between COPD and Parkinson's disease (PD), which is also a neurodegenerative disorder.

METHOD

Our study analyzed medical data from the population of Taiwan from 1998 to 2008, with a follow-up period extending to the end of 2010. We identified patients with COPD by the Taiwan National Health Insurance Research Database (NHIRD). We selected a comparison cohort from the general population that was random frequency-matched by age (in 5-year increments), sex and index year, and further analyzed the risk of PD using Cox's regression model, including sex, age and comorbidities.

RESULTS

The study enrolled 20 728 COPD patients (71.1% male, mean age = 68.2 years) and 41 147 controls. The risk of developing PD was 1.37 times greater in patients with COPD compared with patients without COPD after adjusting for age, sex and comorbidities. A significantly increased risk of PD was also found in patients with COPD who had any comorbidity other than diabetes.

CONCLUSION

This nationwide retrospective cohort study demonstrates that PD risk is significantly increased in patients with COPD compared with those of the general population.

The association between chronic obstructive pulmonary disease and dementia: a population-based retrospective cohort study

BACKGROUND AND PURPOSE

Chronic obstructive pulmonary disease (COPD) is frequently associated with various comorbidities. However, the proportion of COPD patients with dementia has not been adequately examined. This retrospective cohort study investigated the association between COPD and dementia by using a nationwide population-based database in Taiwan.

METHODS

Data were retrieved from the Taiwanese National Health Insurance Research Database and analyzed using multivariate Cox proportional hazards regression models to assess the effects of COPD on the risk of dementia after adjusting for demographic characteristics and comorbidities.

RESULTS

The COPD cohort exhibited a higher prevalence of diabetes, hypertension, coronary artery disease, head injury and depression at baseline than did the non-COPD cohort (P < 0.0001). After adjusting for covariates, the COPD patients exhibited a 1.27-fold higher risk of developing dementia (hazard ratio 1.27, 95% confidence interval 1.20-1.36). The incidence rate was higher in patients with frequent acute exacerbations than in the non-COPD patients regardless of whether a hospital admission or emergency room visit was required (hazard ratio 196.8 vs. 41.7, 95% confidence intervals 145.9-265.5 and 22.3-78.0).

CONCLUSION

This study shows that COPD is associated with a subsequent higher risk of dementia after adjusting for comorbidities. Specifically, the association between COPD and dementia is greater in patients with more frequent acute exacerbation events of COPD.

DNA translocation through short nanofluidic channels under asymmetric pulsed electric field

Investigation of single molecule DNA dynamics in confined environments has led to important applications in DNA analysis, separation, and sequencing. Here, we studied the electrophoretic transport of DNA molecules through nanochannels shorter than the DNA contour length and calculated the associated translocation time curves. We found that the longer T4 DNA molecules required a longer time to traverse a fixed length nanochannel than shorter λ DNA molecules and that the translocation time decreased with increasing electric field which agreed with theoretical predictions. We applied this knowledge to design an asymmetric electric pulse and demonstrate the different responses of λ and T4 DNA to the pulses. We used Brownian dynamics simulations to corroborate our experimental results on DNA translocation behaviour. This work contributes to the fundamental understanding of polymer transport through nanochannels and may help in designing better separation techniques in the future.

Expression of GALNT2 in human extravillous trophoblasts and its suppressive role in trophoblast invasion

Extravillus trophoblast (EVT) invasion plays a critical role in placental development. Integrins bind to extracellular matrix (ECM) proteins to mediate EVT cell adhesion, migration, and invasion. Changes in O-glycans on β1-integrin have been found to regulate cancer cell behavior. We hypothesize that O-glycosyltransferases can regulate EVT invasion through modulating the glycosylation and function of β1-integrin. Here, we found that the GALNT1 and GALNT2 mRNA were highly expressed in HTR8/SVneo and first trimester EVT cells. Immunohistochemstry and immunofluorescence staining showed that GALNT2 was expressed in subpopulations of EVT cells in deciduas, but not in syncytiotrophoblasts and cytotrophoblasts of placental villi. The percentage of GALNT2-positive EVT cells increased with gestational ages. Overexpression of GALNT2 in HTR8/SVneo cells significantly enhanced cell-collagen IV adhesion, but suppressed cell migration and invasion. Notably, we found that GALNT2 increased the expression of Tn antigen (GalNAc-Ser/Thr) on β1-integrin as revealed by Vicia Villosa agglutinin (VVA) binding. Furthermore, GALNT2 suppressed the phosphorylation of focal adhesion kinase (FAK), a crucial downstream signaling molecule of β1-integrin. Our findings suggest that GALNT2 is a critical initiating enzyme of O-glycosylation for regulating EVT invasion.

Effect of phenethyl isothiocyanate on Ca2+ movement and viability in MDCK canine renal tubular cells

The effect of the natural compound phenethyl isothiocyanate (PEITC) on cytosolic Ca2+ concentrations ([Ca2+]i) and viability in MDCK renal cells is unknown. This study explored whether PEITC changed [Ca2+]i in MDCK cells using the Ca2+-sensitive fluorescent dye fura-2. PEITC at 200–700 μM increased [Ca2+]i in a concentration-dependent manner. The signal was reduced by removing extracellular Ca2+. PEITC-induced Ca2+ influx was inhibited by nifedipine, econazole, SK&F 96365 and protein kinase C modulators. In Ca2+-free medium, treatment with the endoplasmic reticulum Ca2+ pump inhibitor thapsigargin (TG) or 2,5-di- tert-butylhydroquinone (BHQ) inhibited PEITC-induced rise in [Ca2+]i. Incubation with PEITC also inhibited TG or BHQ-induced rise in [Ca2+]i. Inhibition of phospholipase C with U73122 abolished PEITC-induced rise in [Ca2+]i. At 15–75 μM, PEITC decreased viability. The cytotoxic effect of PEITC was enhanced by chelating cytosolic Ca2+ with 1,2-bis(2-aminophenoxy)ethane- N, N, N′, N′-tetraacetic acid/acetoxymethyl ester. Annexin V-FITC data suggest that 20 and 50 μM PEITC induced apoptosis. At 10 and 15 μM, PEITC did not increase reactive oxygen species (ROS) production. Together, in renal tubular cells, PEITC-induced rise in [Ca2+]i by inducing phospholipase C-dependent Ca2+ release from endoplasmic reticulum and Ca2+ entry via store-operated Ca2+ channels. PEITC induced apoptosis in a concentration-dependent, ROS/Ca2+-independent manner.

An unusual presentation of catatonia in a patient with schizoaffective disorder

Catatonia is currently a diagnosis that is made clinically; however, due to the varied clinical presentations of catatonia, underdiagnosis is common. We describe an unusual presentation of catatonia in a female patient with schizoaffective disorder. She was successfully treated, albeit with a significant delay. Among an extensive series of laboratory tests and treatment trials, serum levels of D-dimer were elevated during the illness and relieved with recovery.

Neuroendoscopic management of intraventricular germinoma at the foramen of Monro: case report and review of the literature

BACKGROUND

Intraventricular tumors account for approximately 3% of adult brain tumors and 16% of childhood and adolescent brain tumors. Half of the intraventricular tumors in adults and one quarter of those in children are found in the lateral ventricles. Ependymoma, astrocytoma, oligodendroglioma, choroid plexus papilloma, meningioma and subependymal giant cell astrocytoma are the common tumors encountered at this particular site. A germinoma at this site is rare. Microsurgery of intraventricular tumors can be challenging and is performed with potential functional and cognitive complications.

CASE REPORT

A 25-year-old female harboring an intraventricular tumor at the foramen of Monro with resultant obstructive hydrocephalus underwent a right intraventricular endoscopic resection of the tumor by means of frameless neuronavigation guidance and temporary external ventricular drainage. Histology showed the tumor to be a germinoma. The post-operative imaging showed that there was some residual tumor tissue in the fornix. Concerned with possibility of cerebrospinal fluid seeding, we administered postoperative adjuvant craniospinal irradiation. The patient was discharged with a Glascow outcome scale score of 5 and at last the 6-month follow-up there was no evidence of recurrence.

CONCLUSION

This report suggests that in selected cases endoscopic resection of an intraventricular tumor under frameless neuronavigation guidance is feasible and safe. The target can be precisely located and procedure-related adverse events can be minimized.

Methylcobalamin, but not methylprednisolone or pleiotrophin, accelerates the recovery of rat biceps after ulnar to musculocutaneous nerve transfer

Using ulnar nerve as donor and musculocutaneous nerve as recipient we recently demonstrated that end-to-end neurorrhaphy in young adult male Wistar rats resulted in good recovery following protracted survival. Here we explored whether anti-inflammatory drug- methylprednisolone, regeneration/myelination-enhancing agent- methylcobalamin and neurite growth-enhancing and angiogenic factor- pleiotrophin accelerated its recovery. Methylprednisolone suppressed the perineuronal microglial reaction and periaxonal ED-1 expression while pleiotrophin increased the blood vessel density and nerve fiber densities in the reconnected nerve as expected. Neither methylprednisolone nor methylcobalamin altered the expression of growth associated protein 43 in the neurons examined suggesting that they did not interfere with axonal regeneration attempt. Surprisingly methylcobalamin enhanced the recovery of compound muscle action potentials and motor end plate innervation and the performance on sticker removal grooming test and augmented the diameters and myelin thicknesses of regenerated axons dramatically while enhancing S-100 expression in Schwann cells; remarkable recovery was achieved 1 month following neurorrhaphy. Simultaneous methylcobalamin and pleiotrophin treatment resulted in quick and persistent supernumerary reinnervation but failed to enhance the recovery over that of the former alone. Methylprednisolone transiently suppressed the enumeration of regrowing axons. In conclusion, methylcobalamin may be preferred over methylprednisolone to facilitate the recovery of peripheral nerves following end-to-end neurorrhaphy. The long-term effect of this treatment however remains to be clarified.

Effect of thimerosal on Ca2+ movement and viability in human oral cancer cells

The effect of thimerosal on cytosolic free Ca2+ concentrations ([Ca2+]i ) in human oral cancer cells (OC2) is unclear. This study explored whether thimerosal changed basal [Ca2+]i levels in suspended OC2 cells using fura-2. Thimerosal at concentrations between 1and 50 μM increased [Ca2+]i in a concentration-dependent manner. The Ca2+ signal was reduced partly by removing extracellular Ca 2+. Thimerosal-induced Ca2+ influx was not blocked by L-type Ca2+ entry inhibitors and protein kinase C modulators (phorbol 12-myristate 13-acetate [PMA] and GF109203X). In Ca2+-free medium, 50 μM thimerosal failed to induce a [Ca2+]i rise after pretreatment with thapsigargin (an endoplasmic reticulum Ca2+ pump inhibitor). Inhibition of phospholipase C with U73122 did not change thimerosal-induced [Ca2+]i rises. At concentrations between 5 and 10 μM, thimerosal killed cells in a concentration-dependent manner. The cytotoxic effect of 8 μM thimerosal was potentiated by prechelating cytosolic Ca2+ with the Ca2+ chelator 1,2-bis(2-aminophenoxy)ethane-N,N,N′,N′-tetraacetate/acetomethyl (BAPTA/ AM). Flow cytometry data suggested that 1—7 μM thimerosal-induced apoptosis in a concentration-dependent manner. Collectively, in OC2 cells, thimerosal-induced [Ca2+]i rises by causing phospholipase C-independent Ca2+ release from the endoplasmic reticulum and Ca2+ influx through non—L-type Ca2+ channels. Thimerosal killed cells in a concentration-dependent manner through apoptosis.

Novel modeling concept for evaluating the effects of cadmium and copper on heterotrophic growth and lysis rates in activated sludge process

A new modeling concept to evaluate the effects of cadmium and copper on heterotrophic growth rate constant (mu(H)) and lysis rate constant (b(H)) in activated sludge was introduced. The oxygen uptake rate (OUR) was employed to measure the constants. The results indicated that the mu(H) value decreased from 4.52 to 3.26 d(-1) or by 28% when 0.7 mg L(-1) of cadmium was added. Contrarily the b(H) value increased from 0.31 to 0.35 d(-1) or by 11%. When adding 0.7 mg L(-1) of copper, the mu(H) value decreased to 2.80 d(-1) or by 38%. The b(H) value increased to 0.42 d(-1) or by 35%. After regression, the inhibitory effect was in a good agreement with non-competitive inhibition kinetic. The inhibition coefficient values for cadmium and copper were 1.82 and 1.21 mg L(-1), respectively. The relation between the b(H) values and heavy metal concentrations agreed with exponential type well. The heavy metal would enhance b(H) value. Using these data, a new kinetic model was established and used to simulate the degree of inhibition. It was evident that not only the inhibitory effect on mu(H) but also that the enhancement effect on b(H) should be considered when heavy metal presented.

Interaction of polybrominated diphenyl ethers (PBDEs) with anaerobic mixed bacterial cultures isolated from river sediment

The degradation of flame retardant polybrominated diphenyl ethers (PBDE), including tetra-brominated diphenyl ether (BDE-47), penta-brominated diphenyl ether (BDE-99 and -100), and hexa-brominated diphenyl ether (BDE-153 and -154), by anaerobic bacterial mixed cultures isolated from river sediment was investigated. The effects of PBDEs on changes of anaerobic bacterial community in sediment culture were also studied. Sediments were collected from Er-Jen River and Nan-Kan River basins, which were both heavily polluted rivers in Taiwan, and bacteria from the sediment samples were enriched before the experiment was conducted. Into the anaerobic bacterial mixed cultures, 0.1 microg/mL of PBDEs was added followed by incubation under 30 degrees C for 70 days. Residues of PBDE were determined by gas chromatography with electron capture detector (GC-ECD), and the changes of bacterial community were analyzed by denaturing gradient gel electrophoresis (DGGE). Less than 20% of PBDEs were degraded after 70 days of incubation in all samples except for BDE-47 from the Nan-Kan River sediment. In that culture, BDE-47 was found to have notably degraded. In particular, after 42 days of incubation; BDE-47 was degraded, suddenly and sharply, to a negligible level on Day 70, and the result was confirmed by a repeated experiment. An interesting result was that although BDE-47 was degraded fast in the Nan-Kan River sediment, the bacterial communities did not shift significantly as we had speculated at Day 70. From UPGMA dendrograms, PBDEs changed the composition of bacterial communities, and the extents varied with the variety of PBDE congeners. By the amendment with BDE-153 or -154, bacterial communities would be changed immediately and irreversibly throughout the rest of the incubation period. No significant difference in degradation of PBDEs was observed between sediment bacteria from Er-Jen River and Nan-Kan River. However, the results verified the persistence of PBDEs in the environment.

Catastrophic gastrointestinal manifestations of post-transplant lymphoproliferative disorder

Post-transplant lymphoproliferative disorder is a rare complication after bone marrow transplantation and frequently involves gastrointestinal tract, but the endoscopic characteristics and catastrophic clinical manifestations in adults have not been discussed in detail. We report a 35-year-old allogeneic bone marrow transplantation recipient who presented with recurrent gastrointestinal bleeding. Ulcerative nodular lesions were noted in stomach, duodenum and ileum on endoscopy but were not biopsied because of thrombocytopenia. Obstruction and perforation of small intestine occurred 5 months after bone marrow transplantation and was managed with surgery. Histopathology revealed the diagnosis of Epstein-Barr virus related post-transplant lymphoproliferative disorder. Rituximab was given after operation but repeated intestinal perforation supervened and resulted in mortality. The characteristic endoscopic and radiographic features are presented. Recognition of these characteristic endoscopic and radiographic findings with histological confirmation is crucial in making early diagnosis, and prompt treatment may prevent gastrointestinal complications and mortality.

Analysis of heart donation for cardiac transplantation at the National Taiwan University Hospital: Fifteen-year cases review

The demand for organ transplantation is disparate to the supply of organ donors. The organ shortage is a limitation for transplantation. This study analyzed the status of heart donors at the National Taiwan University Hospital (NTUH) from July 1987 through November 2001 using registry records. One hundred ninety-four total heart donors yielded about 25 donors per year in the late era (years of 1995-2001). The majority of heart donors were men (78.4%) of O blood type (46.9%) with a mean age of 29.8 (SD = 11.9) years. Though head injury was the main source of heart donors (78.4%), cerebrovascular accident patients have increased (15%) since 1995. However, the number of donors from head injury decreased in the year of 1997, when Taiwan passed a law to force motorcycle drivers to wear safety helmets. The average interval from brain death to donation was 75.4 (SD = 71.2) hours. One hundred fifty-six (80.4%) of the 194 donor hearts came from outside hospitals. However, the majority of heart transplantations (166 cases, 85.6%) were done at the NTUH. Implementing a program for a smooth donation and organ procurement processes should provide better donor management in cardiac transplantation.

Omapatrilat versus lisinopril: efficacy and neurohormonal profile in salt-sensitive hypertensive patients

Omapatrilat, a vasopeptidase inhibitor, simultaneously inhibits neutral endopeptidase and ACE. The efficacy and hormonal profile of omapatrilat and lisinopril were compared in salt-sensitive hypertensive patients. On enrollment, antihypertensive medications were withdrawn, and patients received a single-blind placebo. On day 15, salt-sensitivity determinations were made. Salt-sensitive hypertensive patients returned within 5 to 10 days for baseline evaluations of ambulatory diastolic blood pressure, ambulatory systolic blood pressure, and atrial natriuretic peptide. Salt-sensitive hypertensive patients were randomized to receive double-blind omapatrilat (n=28) or lisinopril (n=33) at initial doses of 10 mg for 1 week, increasing to 40 and 20 mg, respectively, for an additional 3 weeks. Ambulatory blood pressure and urinary atrial natriuretic peptide were assessed at study termination. Both omapatrilat and lisinopril significantly reduced mean 24-hour ambulatory diastolic and systolic blood pressures; however, omapatrilat produced significantly greater reductions in mean 24-hour ambulatory diastolic blood pressure (P=0.008), ambulatory systolic blood pressure (P=0.004), and ambulatory mean arterial pressure (P=0.005) compared with values from lisinopril. Both drugs potently inhibited ACE over 24 hours. Omapatrilat significantly (P<0.001) increased urinary excretion of atrial natriuretic peptide over 0- to 24-hour (3.8-fold) and 12- to 24-hour (2-fold) intervals; lisinopril produced no change. Omapatrilat significantly (P<0.001) increased urinary excretion of cGMP over the 0- to 24- and 4- to 8-hour intervals compared with that from lisinopril. Neither drug had a diuretic, natriuretic, or kaliuretic effect. In conclusion, in salt-sensitive hypertensive patients, omapatrilat demonstrated the hormonal profile of a vasopeptidase inhibitor and lowered ambulatory diastolic and systolic blood pressures more than lisinopril.

The cardiovascular actions of omapatrilat in spontaneously hypertensive rats

Omapatrilat is a newly developed vasopeptidase inhibitor that inhibits both angiotensin-converting enzyme (ACE) and neutral endopeptidase and has potent antihypertensive efficacy. However, the specific effect of omapatrilat on cardiac function and left ventricular hypertrophy with hypertension remains controversial. Therefore, we investigated the effect of omapatrilat on blood pressure, cardiac hypertrophy, and cardiac function in spontaneously hypertensive rats (SHR). Studies were performed in SHR that received vehicle (n = 9), omapatrilat (n = 10), or fosinopril (ACE inhibitor, n = 7) by daily gavage for 56 days. Systolic blood pressure (SBP) and mean blood pressure (MBP) were measured by tail plethysmography. Left ventricular fractional shortening and left ventricular mass were measured by echocardiography at day 56. Omapatrilat and fosinopril significantly decreased SBP and MBP from day 1 through day 56, and omapatrilat markedly reduced SBP and MBP compared with fosinopril from day 21 to day 56. Although both omapatrilat and fosinopril decreased left ventricular mass and left ventricular mass-to-body weight ratio with increased LV fractional shortening, omapatrilat had a more potent effect on the reduction of left ventricular mass and improvement of cardiac function. This study shows that in SHR, omapatrilat mediated a potent and stable antihypertensive effect and a reduction in left ventricular mass with improvement of cardiac function, compared with ACE inhibition alone.

Pharmacodynamics and pharmacokinetics of omapatrilat in heart failure

The purpose of this study was to determine the pharmacodynamics and pharmacokinetics of omapatrilat, administered orally (25 mg) or intravenously (10 mg) in 19 New York Heart Association class II and class III congestive heart failure (CHF) patients versus 17 healthy controls matched for age, race, gender, and weight. The plasma concentrations of atrial natriuretic peptide (ANP) increased by approximately 20% and 30% in CHF and control subjects, respectively, at 4 hours after intravenous or oral omapatrilat administration. Similar elevation in the cyclic guanosine monophosphate concentration (25% to 35%) and ANP urinary excretion (21 ng/24 h to 22 ng/24 h) was seen in all treatment groups after omapatrilat administration. Angiotensin-converting enzyme activity was > 90% inhibited at 4 hours after dosing and remained approximately 60% to 70% inhibited at 24 hours after dosing. The levels of endothelin-1 and endothelin-2 remained unchanged after oral or intravenous administration of omapatrilat. The maximal reduction in seated blood pressure compared with baseline was similarfor CHF and control subjects. Clinical pharmacokinetic parameters were similar in both groups after intravenous dosing, but maximum concentration and area under the concentration-time curve were elevated in CHF patients compared with controls after oral dosing. Omapatrilat was well tolerated; differences in systemic exposure and metabolism between CHF patients and controls did not appear to be clinically significant.

Omapatrilat: neurohormonal and pharmacodynamic profile when administered with furosemide

Pharmacodynamic effects of combination therapy with omapatrilat and furosemide were evaluated. Two groups of 13 healthy subjects each received furosemide 20 mg dailyfor 15 days coadministered with either placebo on days 6 to 15 or omapatrilat 10 mg on days 6 to 10 and 25 mg on days 11 to 15. In the omapatrilat group, urinary excretion of atrial natriuretic peptide increased, and greater blood pressure reductions were seen compared with placebo. Concomitant omapatrilat treatment did not affect the acute diuresis, natriuresis, and kaliuresis observed with chronic administration of furosemide. Neither effective renal plasma flow nor glomerularfiltration rate changed in either treatment group. No clinically significant safety issues were observed. Daily coadministration of omapatrilat 10 or 25 mg with furosemide 20 mg does not affect the pharmacodynamics offurosemide at steady state.

Oral bioavailability and disposition of [14C]omapatrilat in healthy subjects

The objective of this study was to determine the absolute oral bioavailability and disposition of omapatrilat. This single-dose, randomized, crossover study of 20 mg intravenous and 50 mg oral [14C]omapatrilat was conducted in 12 healthy male subjects to determine the disposition and oral bioavailability of omapatrilat, an orally active vasopeptidase inhibitor. Blood samples were collected up to 120 hours, and the excreta were collected over 168 hours postdose. Plasma concentrations of omapatrilat were determined by a validated LC/MS/MS procedure. Radioactivity in blood, plasma, urine, and feces was determined by liquid scintillation counting. Urinary excretion of radioactivity averaged 80% and 64% of intravenous and oral doses, respectively; < 1% of oral dose was excreted unchanged in urine. The absolute oral bioavailability of omapatrilat averaged 31%. Total body clearance of omapatrilat (80 L/h) exceeded liver plasma flow. Apparent steady-state volume of distribution of omapatrilat (21 L/kg) was extremely high compared with total body water. Omapatrilat undergoes substantial presystemic first-pass metabolism after oral administration. Omapatrilat is eliminated primarily by metabolism, and its metabolites are eliminated primarily in urine. Extrahepatic organs may be involved in the elimination of omapatrilat. Plasma concentrations of omapatrilat exhibit a prolonged terminal elimination phase, which represents elimination from a deep compartment.

Cell autonomous apoptosis defects in acid sphingomyelinase knockout fibroblasts

A body of evidence suggests that stress-induced sphingomyelin hydrolysis to the second messenger ceramide initiates apoptosis in some cells. Although studies using lymphoblasts from Niemann-Pick disease patients or acid sphingomyelinase (ASMase)-deficient mice have provided genetic support for this hypothesis, these models have not been universally accepted as definitive. Here, we show that mouse embryonic fibroblasts (MEFs) prepared from asmase mice manifest cell autonomous defects in apoptosis in response to several stresses. In particular, asmase(-/-) MEFs failed to generate ceramide and were totally resistant to radiation-induced apoptosis but remained sensitive to staurosporine, which did not induce ceramide. asmase(-/-) MEFs were also partially resistant to tumor necrosis factor alpha/ actinomycin D and serum withdrawal. Thus, resistance to apoptosis in asmase(-/-) MEFs was not global but rather stress type specific. Most importantly, the sensitivity to stress could be restored in the asmase(-/-) MEFs by administration of natural ceramide. Overcoming apoptosis resistance by natural ceramide is evidence that it is the lack of ceramide, not ASMase, that determines apoptosis sensitivity. The ability to rescue the apoptotic phenotype without reversing the genotype by the product of the enzymatic deficiency provides proof that ceramide is obligate for apoptosis induction in response to some stresses.

Weight-correction formula for maternal serum screening for Down syndrome in Taiwan

BACKGROUND AND PURPOSE

This study examined the relationship between maternal weight and serum marker concentrations (alpha-fetoprotein [AFP] and human chorionic gonadotropin [hCG]) to develop a weight-correction formula for second-trimester Down syndrome screening in Taiwan.

METHODS

We conducted a prospective observational study based on data from 18, 016 pregnant Taiwanese women who participated in a second-trimester Down syndrome screening program at Taiwan Adventist Hospital. The relationship between maternal weight and the multiple of median (MoM) concentrations of serum markers was analyzed using two methods; one involved all the observational data (all point method), while the other involved only the median concentrations at various gestational ages (median regression method). In each method, several statistical approaches were used, including simple-linear, reciprocal, quadratic, and log-transformation linear regression.

RESULTS

The correlation between maternal body weight and serum marker concentrations using the all point regression method was very poor, while the median regression method achieved a good fit. The reciprocal regression analysis had the best fit between AFP MoM concentration and maternal weight, while the best fit between hCG MoM concentration and maternal weight was achieved with quadratic regression analysis.

CONCLUSION

The present study has developed a race-specific weight-correction formula for Taiwanese women. This formula is expected to be helpful in second-trimester Down syndrome screening programs in Taiwan.

Quantitative structure-activity relationships for the pre-steady-state inhibition of cholesterol esterase by 4-nitrophenyl-N-substituted carbamates

4-Nitrophenyl-N-substituted carbamates (1-6) are the pseudo-substrate inhibitors of porcine pancreatic cholesterol esterase. Thus, the first step of the inhibition (Ki step) is the formation of the enzyme inhibitor tetrahedral adduct and the second step of the inhibition (kc) is the formation of the carbamyl enzyme. The formation of the enzyme inhibitor tetrahedral adduct is further divided into two steps, the formation of the enzyme-inhibitor complex with the dissociation constant, KS, at the first step and the formation of the enzyme-inhibitor tetrahedral adduct from the complex at the second step. The two-step mechanism for the formation of the enzyme-inhibitor tetrahedral adduct is confirmed by the pre-steady-state kinetics. The results of quantitative structure-activity relationships for the pre-steady-state inhibitions of cholesterol esterase by carbamates 1-6 indicate that values of -logKs and logk2/k-2 are correlated with the Taft substituent constant, sigma*, and the rho* values from these correlations are -0.33 and 0.1, respectively. The negative rho* value for the -logKS-sigma*-correlation indicates that the first step of the two-step formation of the enzyme-inhibitor tetrahedral adduct (KS step) is the formation of the positive enzyme inhibitor complex. The positive rho* value for the logk2/k-2 -sigma*-correlation indicates that the enzyme inhibitor tetrahedral adduct is more negative than the enzyme inhibitor complex. Finally, the two-step mechanism for the formation of the enzyme inhibitor tetrahedral adduct is proposed according to these results. Thus, the partially positive charge is developed at nitrogen of carbamates 1-6 in the enzyme-inhibitor complex probably due to the hydrogen bonding between the lone pair of nitrogen of carbamates 1-6 and the amide hydrogen of the oxyanion hole of the enzyme. The second step of the two-step formation of the enzyme-inhibitor tetrahedral adduct is the nucleophilic attack of the serine of the enzyme to the carbonyl group of carbamates 1-6 in the enzyme-inhibitor complex and develops the negative-charged oxygen in the adduct.

Binary/ternary combined effects of vitamin K3 with other antitumor agents in nasopharyngeal carcinoma CG1 cells

Nasopharyngeal carcinoma (NPC) is a prevalent cancer in Taiwan. To improve the treatment of NPC, we have extensively searched for effective combination chemotherapies. Our previous studies indicated that vitamin K3 (VK3) inhibits the growth of NPC CG1 cells in vitro. In this study, we further studied the binary/ternary combined effects of VK3 with other anticancer drugs against NPC cells. The antitumor effects of different VK3 combinations against CG1 cells were determined by using MTT assay, and the combined effects were evaluated by a taibologram, a modified isobolographic method being developed in our laboratory for the analyses of binary/ternary combinations of anticancer agents. Binary combinations of VK3 with doxorubicin (DOX), vinblastine (VBL), or 5-fluorouracil (5-FU) result in synergistic effects. For three-drug combinations, a remarkable synergy was found in the combination of VK3, VBL, and 5-FU. These in vitro results will provide useful information not only for further mechanistic studies and but also for future clinical trials of VK3-based cancer chemotherapy of NPC.

Comparison of the pharmacokinetics of fosinoprilat with enalaprilat and lisinopril in patients with congestive heart failure and chronic renal insufficiency

AIMS

To compare the serum pharmacokinetics of fosinoprilat with enalaprilat and lisinopril after 1 and 10 days of dosing with fosinopril, enalapril and lisinopril.

METHODS

Patients with congestive heart failure (CHF, NYHA Class II-IV) and chronic renal insufficiency (creatinine clearance </=30 ml min-1 ) were randomized to receive fosinopril, enalapril or lisinopril in two parallel-group studies. In the first study 24 patients were treated with 10 mg fosinopril (n=12 patients) or 2.5 mg enalapril (n=12) every morning for 10 consecutive days. In the second study 31 patients were treated with 10 mg fosinopril (n=16 patients) or 5 mg lisinopril (n=15) every morning for 10 consecutive days. Samples of blood were collected for determination of pharmacokinetic parameters. The area under the curve (AUC) between the first and last days of treatment and the accumulation index (AI) were the primary outcome measures.

RESULTS

All three angiotensin converting enzyme (ACE) inhibitors exhibited a significant increase in AUC between the first and last days of treatment in both studies. The difference between the AI for fosinoprilat (1.41) and enalaprilat (1.96) was statistically significant (95% CI: 1.05, 1.84). Similarly, the difference between the AI for fosinoprilat (1.21) and lisinopril (2.76) was statistically significant (95% CI: 1.85, 2.69). All three ACE inhibitors completely inhibited serum ACE for 24 h. All treatments were well tolerated.

CONCLUSIONS

Fosinoprilat exhibits significantly less accumulation than enalaprilat or lisinopril in patients with CHF and renal insufficiency, most probably because fosinoprilat is eliminated by both the kidney and liver, and increased hepatic elimination can compensate for reduced renal clearance in patients with kidney dysfunction.

Molecular recognition by acetylcholinesterase at the peripheral anionic site: structure-activity relationships for inhibitions by aryl carbamates

Substituted phenyl-N-butyl carbamates (1-9) are potent irreversible inhibitors of Electrophorus electricus acetylcholinesterase. Carbamates 1-9 act as the peripheral anionic site-directed irreversible inhibitors of acetylcholinesterase by the stop-time assay in the presence of a competitive inhibitor, edrophonium. Linear relationships between the logarithms of the dissociation constant of the enzyme inhibitor adduct (Ki), the inactivation constant of the enzyme-inhibitor adduct (k2), and the bimolecular inhibition constant (k(i)) for the inhibition of Electrophorus electricus acetylcholinesterase by carbamates 1-9 and the Hammett substituent constant (sigma), are observed, and the reaction constants (ps) are -1.36, 0.35 and -1.01, respectively. Therefore, the above reaction may form a positive charged enzyme-inhibitor intermediate at the peripheral anionic site of the enzyme and may follow the irreversible inactivation by a conformational change of the enzyme.

Reversal of radiation resistance in LNCaP cells by targeting apoptosis through ceramide synthase

Cell lines derived from human prostate cancer are regarded as relatively resistant to both radiation-induced clonogenic death and apoptosis. Here we attempted to modulate the response of LNCaP prostate cancer cells to radiation therapy (XRT) by pretreatment with 12-O-tetradecanoylphorbol acetate (TPA), a known apoptogenic agent in LNCaP cells. Using plateau-phase cultures, we investigated the response of these cells to XRT, TPA, and a combination of XRT and TPA. LNCaP irradiation did not result in ceramide generation or apoptosis. However, pretreatment with TPA enabled XRT to generate ceramide via activation of the enzyme ceramide synthase and signal apoptosis. Apoptosis was abrogated by the competitive inhibitor of ceramide synthase, fumonisin B1. Furthermore, when transplanted orthotopically into the prostate of nude mice, LNCaP cells produced tumors that recapitulated the responses of LNCaP cells in vitro. XRT or TPA failed to signal apoptosis in LNCaP tumors, whereas a combination of the two resulted in substantial (20-25%) apoptosis within 24 h. There was an additional benefit associated with this regimen because TPA pretreatment protected the adjacent rectum from radiation-induced apoptosis. This represents the first description of signaling-based therapy designed to overcome one form of radiation resistance expressed preferentially in LNCaP human prostate cancer cells.

Ataxia telangiectasia-mutated gene product inhibits DNA damage-induced apoptosis via ceramide synthase

DNA double-stranded breaks (dsb) activate surveillance systems that identify DNA damage and either initiate repair or signal cell death. Failure of cells to undergo appropriate death in response to DNA damage leads to misrepair, mutations, and neoplastic transformation. Pathways linking DNA dsb to reproductive or apoptotic death are virtually unknown. Here we report that metabolic incorporation of 125I-labeled 5-iodo-2'deoxyuridine, which produces DNA dsb, signaled de novo ceramide synthesis by post-translational activation of ceramide synthase (CS) and apoptosis. CS activation was obligatory, since fumonisin B1, a fungal pathogen that acts as a specific CS inhibitor, abrogated DNA damage-induced death. X-irradiation yielded similar results. Furthermore, inhibition of apoptosis using the peptide caspase inhibitor benzyloxycarbonyl-Val-Ala-Asp fluoromethylketone did not affect CS activation, indicating this event is not a consequence of induction of apoptosis. ATM, the gene mutated in ataxia telangiectasia, is a member of the phosphatidylinositol 3-kinase family that constitutes the DNA damage surveillance/repair system. Epstein-Barr virus-immortalized B cell lines from six ataxia telangiectasia patients with different mutations exhibited radiation-induced CS activation, ceramide generation, and apoptosis, whereas three lines from normal patients failed to manifest these responses. Stable transfection of wild type ATM cDNA reversed these events, whereas antisense inactivation of ataxia telangiectasia-mutated gene product in normal B cells conferred the ataxia telangiectasia phenotype. We propose that one of the functions of ataxia telangiectasia-mutated gene product is to constrain activation of CS, thereby regulating DNA damage-induced apoptosis.