Cardiac Safety Assessment of Lazertinib: Findings From Patients With EGFR Mutation-Positive Advanced NSCLC and Preclinical Studies

Introduction

Lazertinib is a potent, irreversible, brain-penetrant, mutant-selective, and wild-type–sparing third-generation EGFR tyrosine kinase inhibitor (TKI), creating a wide therapeutic index. Cardiovascular adverse events (AEs), including QT prolongation, decreased left ventricular ejection fraction (LVEF), and heart failure, have emerged as potential AEs with certain EGFR TKI therapies.

Methods

Cardiac safety of lazertinib was evaluated in TKI-tolerant adults with EGFR mutation-positive locally advanced or metastatic NSCLC receiving lazertinib (20–320 mg/d). QT intervals corrected with Fridericia’s formula (QTcF) prolongation, time-matched concentration-QTcF relationship, change of LVEF, and cardiac failure-associated AEs were evaluated. The clinical findings were supplemented by the following three preclinical studies: an in vitro hERG inhibition assay, an ex vivo isolated perfused rabbit heart study, and an in vivo telemetry-instrumented beagle dog study.

Results

Preclinical evaluation revealed little to no physiological effect on the basis of electrocardiogram, electrophysiological, proarrhythmic, and hemodynamic parameters. Clinical evaluation of 181 patients revealed no clinically relevant QTcF prolongation by centralized electrocardiogram in any patient and at any dose level. The predicted magnitude of QTcF value increase at maximum steady-state plasma concentration for the therapeutic dose of lazertinib (240 mg/d) was 2.2 msec (upper bound of the two-sided 90% confidence interval: 3.6 msec). No patient had clinically relevant LVEF decrease (i.e., minimum postbaseline LVEF value of <50% and a maximum decrease in LVEF value from baseline of ≥10 percentage points). Cardiac failure-associated AE occurred in one patient (grade 2 decreased LVEF) and resolved without any dose modifications.

Conclusions

Our first-in-human study, together with preclinical data, indicates that lazertinib is not associated with increased cardiac risk.

Craniofacial features affecting mandibular asymmetries in skeletal Class II patients

OBJECTIVES

The aim of this study was to evaluate the characteristics affecting different intensities of mandibular asymmetry in skeletal Class II adults using three-dimensional images. This study is clinically relevant since it allows professionals to evaluate the morphological components related to these deformities and more carefully obtain correct diagnosis and treatment plan for such patients.

METHODS

Cone-beam computed tomography data of 120 Class II patients (40 with relative symmetry, 40 with moderate asymmetry, and 40 with severe asymmetry) were imported to SimPlant Ortho Pro^® 2.0 software (Dental Materialise, Leuven, Belgium). Three reference planes were established and linear measurements were performed from specific landmarks to these planes, comparing the deviated side and the contralateral side in each group, as well as the differences between groups. The correlation between midline mandibular asymmetry and other variables was also evaluated. Statistical analyses considered a significance level of 5%.

RESULTS

Comparing the values obtained on the deviated side and on the contralateral side, there were significant differences for patients with moderate asymmetry and severe asymmetry. However, differences were seen more often in severe mandibular asymmetries. In those patients, there was a significant correlation of the gnathion deviation with lower dental midline deviation, difference in the lateral gonion positions, difference in the mandibular rami heights, and difference in the jugale vertical displacements.

CONCLUSIONS

For skeletal Class II patients with mandibular asymmetry, some craniofacial features are related to chin deviation and require proper evaluation, including the bilateral differences in the ramus height, mandibular body length, transverse and vertical positioning of the gonion and jugale points.

Deformation mechanisms to ameliorate the mechanical properties of novel TRIP/TWIP Co-Cr-Mo-(Cu) ultrafine eutectic alloys

In the present study, the microstructural evolution and the modulation of the mechanical properties have been investigated for a Co-Cr-Mo (CCM) ternary eutectic alloy by addition of a small amount of copper (0.5 and 1 at.%). The microstructural observations reveal a distinct dissimilarity in the eutectic structure such as a broken lamellar structure and a well-aligned lamellar structure and an increasing volume fraction of Co lamellae as increasing amount of copper addition. This microstructural evolution leads to improved plasticity from 1% to 10% without the typical tradeoff between the overall strength and compressive plasticity. Moreover, investigation of the fractured samples indicates that the CCMCu alloy exhibits higher plastic deformability and combinatorial mechanisms for improved plastic behavior. The improved plasticity of CCMCu alloys originates from several deformation mechanisms; i) slip, ii) deformation twinning, iii) strain-induced transformation and iv) shear banding. These results reveal that the mechanical properties of eutectic alloys in the Co-Cr-Mo system can be ameliorated by micro-alloying such as Cu addition.

DBC2/RhoBTB2 functions as a tumor suppressor protein via Musashi-2 ubiquitination in breast cancer

The gene encoding ‘deleted in breast cancer 2' (DBC2), also referred to as RHOBTB2 (Rho-related BTB domain-containing protein 2), is classified as a tumor suppressor gene. DBC2 is a substrate-specific adaptor protein for a novel class of Cullin-3 (CUL3)-based E3 ubiquitin ligases; however, it is unclear if the substrate adaptor function of DBC2 is required for its tumor suppressor activity. Furthermore, the key substrates of DBC2-mediated ubiquitination have yet to be identified. In the present study, we established a genome-wide human cDNA library-based in vitro ubiquitination target screening assay and identified Musashi-2 (MSI2) as a novel ubiquitination target protein of DBC2. MSI2 directly interacted with DBC2, and this interaction promoted MSI2 polyubiquitination and proteasomal degradation in breast cancer cells. Overexpression and knockdown experiments demonstrated that DBC2 suppressed MSI2-associated oncogenic functions and induced apoptosis. Immunohistochemistry analysis of a breast cancer tissue microarray revealed that DBC2 and MSI2 protein levels are inversely correlated in both normal breast tissues and breast cancer tissues. Taken together, these findings provide evidence that DBC2 suppresses tumorigenesis in breast cancer by ubiquitinating MSI2.

Characteristics of pyrexia in BRAFV600E/K metastatic melanoma patients treated with combined dabrafenib and trametinib in a phase I/II clinical trial

BACKGROUND

Pyrexia is a frequent adverse event with combined dabrafenib and trametinib therapy (CombiDT), but little is known of its clinical associations, etiology, or appropriate management.

PATIENTS AND METHODS

All patients on the BRF133220 phase I/II trial of CombiDT treated at the standard dose (150/2) were included for assessment of pyrexia (n = 201). BRAF and MEK inhibitor-naïve patients (n = 117) were included for efficacy analyses. Pyrexia was defined as temperature ≥38°C (≥100.4(°)F) or related symptoms.

RESULTS

Fifty-nine percent of patients developed pyrexia during treatment, 24% of which had pyrexia symptoms without a recorded elevation in body temperature. Pyrexia was grade 2+ in 60% of pyrexia patients. Median time to onset of first pyrexia was 19 days, with a median duration of 9 days. Pyrexia patients had a median of two pyrexia events, but 21% had three or more events. Various pyrexia management approaches were conducted in this study. A trend was observed between dabrafenib and hydroxy-dabrafenib exposure and pyrexia. No baseline clinical characteristics predicted pyrexia, and pyrexia was not statistically significantly associated with treatment outcome.

CONCLUSIONS

Pyrexia is a frequent and recurrent toxicity with CombiDT treatment. No baseline features predict pyrexia, and it is not associated with clinical outcome. Dabrafenib and metabolite exposure may contribute to the etiology of pyrexia. The optimal secondary prophylaxis for pyrexia is best studied in a prospective trial.

Mechanically stable tuning fork sensor with high quality factor for the atomic force microscope

A quartz tuning fork was used instead of cantilever as a force sensor for the atomic force microscope. A tungsten tip was made by electrochemical etching from a wire of 50 µm diameter. In order to have mechanical stability of the tuning fork, it was attached on an alumina plate. The tungsten tip was attached on the inside end of a prong of a tuning fork. The phase shift was used as a feedback signal to control the distance between the tip and sample, and the amplitude was kept constant using a lock-in amplifier and a homemade automatic gain controller. Due to the mechanical stability, the sensor shows a high quality factor (∼10(3)), and the image quality obtained with this sensor was equivalent to that of the cantilever-based AFM.

Relationship between early postoperative C-reactive protein elevation and long-term postoperative major adverse cardiovascular and cerebral events in patients undergoing off-pump coronary artery bypass graft surgery: a retrospective study

BACKGROUND

Inflammation plays a key role in the pathogenesis of vascular occlusive diseases, such as myocardial infarction and stroke. Additionally, these conditions are predicted by C-reactive protein (CRP), a general inflammation marker. We hypothesized that the inflammation induced by surgery itself augments vascular occlusive disease. We retrospectively evaluated the relationship between postoperative CRP elevation and postoperative major adverse cardiovascular and cerebral events (MACCE) in patients undergoing off-pump coronary artery bypass surgery (OPCAB).

METHODS

The electronic medical records of 1046 patients who underwent OPCAB were reviewed retrospectively. The relationship between postoperative serum CRP and long-term postoperative MACCE (median follow-up 28 months) was investigated.

RESULTS

Patients were divided into quartiles according to maximum postoperative CRP levels (<18, 18-22, 22-27, ≥27 mg dl(-1)). The adjusted hazard ratios (HRs) were 2.15, 2.45, and 2.81, respectively (P=0.004), compared with the lowest quartile (<18 mg dl(-1)). In the multivariate analysis, the postoperative CRP quartile (HR 2.81; P=0.004), postoperative non-use of statins (HR 1.86; P=0.003), and postoperative maximum troponin I (HR 1.02; P<0.001) independently predicted postoperative MACCE, while preoperative CRP did not (P=0.203). Several parameters were correlated with postoperative maximum CRP level: body temperature (P=0.001) and heart rate (P<0.001) at the end of surgery; intraoperative last lactate (P<0.001) and base excess (P<0.001); and red blood cell transfusion (P=0.019).

CONCLUSIONS

Postoperative CRP elevation was associated with long-term postoperative MACCE in OPCAB patients. This was mitigated by postoperative statin medication. Furthermore, postoperative CRP elevation was associated with intraoperative parameters reflecting hypoperfusion and inflammation.

Melanoma patients in a phase I clinic: molecular aberrations, targeted therapy and outcomes

BACKGROUND

The purpose of the study was to assess the outcome of patients with advanced melanoma treated with matched molecularly targeted therapy.

PATIENTS AND METHODS

We reviewed 160 consecutive patients with metastatic melanoma treated in the phase I program (N = 35 protocols). Treatment was considered to be 'matched' (N = 84) if at least one drug in the regimen was known to inhibit the functional activity of at least one of the patient's mutations.

RESULTS

Of 160 patients, 134 (83.7%) had adequate tissue for molecular analysis; 69% (110 of 160) had ≥1 mutation: 61.2% (82 of 134), BRAF; 20.7% (23 of 111), NRAS; 2.6% (2 of 77), KIT; 2.3% (1 of 44), KRAS; 20% (1 of 5), GNAQ; 11.1% (1 of 9), P53 and 2.6% (1 of 39), coexisting mutations in BRAF and PIK3CA. Eighty-four patients (52.4%) were treated with matched-targeted agents, most of whom had BRAF mutations (N = 74). Twenty-six percent of patients (41 of 160) achieved a complete or partial remission (CR/PR) [40% (34 of 84)) on a matched phase I protocol versus 9.2% (7 of 76) for those on a non-matched study (P ≤ 0.0001)]. The median progression-free survival (PFS) (95% CI) was longer for patients treated on a matched phase I trial than on their prior first standard treatment [5.27 (4.10, 6.44) versus 3.10 (1.92, 4.28) months, P = 0.023], but not on non-matched phase I treatment. Multivariable analysis showed that matched therapy was an independent predictor of higher CR/PR rates, prolonged PFS and survival.

CONCLUSIONS

For melanoma patients, especially those with BRAF mutations, administering molecularly matched agents can be associated with better outcomes, including longer PFS compared with their first-line systemic therapy.

Graphite patterning in a controlled gas environment

Although a number of methods using scanning probe lithography to pattern graphene have already been introduced, the fabrication of real devices still faces limitations. We report graphite patterning using scanning probe lithography with control of the gas environment. Patterning processes using scanning probe lithography of graphite or graphene are normally performed in air because water molecules forming the meniscus between the tip and the sample mediate the etching reaction. This water meniscus, however, may prevent uniform patterning due to its strong surface tension or large contact angle on surfaces. To investigate this side effect of water, our experiment was performed in a chamber where the gas environment was controlled with methyl alcohol, oxygen or isopropanol gases. We found that methyl alcohol facilitates graphite etching, and a line width as narrow as 3 nm was achieved as methyl alcohol also contains an oxygen atom which gives rise to the required oxidation. Due to its low surface tension and highly adsorptive behavior, methyl alcohol has advantages for a narrow line width and high speed etching conditions.

Phase 3 study of docosahexaenoic acid-paclitaxel versus dacarbazine in patients with metastatic malignant melanoma

BACKGROUND

Docosahexaenoic acid-paclitaxel (DHA-paclitaxel, Taxoprexin(®)) is made by covalently conjugating the essential fatty acid DHA to the paclitaxel molecule. Preclinical studies of DHA-paclitaxel have demonstrated increased activity relative to paclitaxel and the potential for an improved therapeutic ratio. In the present study, the efficacy and toxicity profiles of DHA-paclitaxel were compared with those of dacarbazine.

METHODS

In this study, 393 chemonaive patients with metastatic melanoma were randomly assigned to receive either DHA-paclitaxel at a starting dose of 900 mg/m(2) IV on day 1 every 3 weeks or dacarbazine at a starting dose of 1000 mg/m(2) IV on day 1 every 3 weeks. The primary end point of the study was the comparison of overall survival (OS).

RESULTS

No significant difference in OS was noted between patients in the DHA-paclitaxel and dacarbazine arms. Similarly, there were no significant differences in response rate, duration of response, time to progression, and time to treatment failure between the two drugs. Safety results of the two drugs were as predicted from prior studies. Myelosuppression was more common with DHA-paclitaxel.

CONCLUSIONS

DHA-paclitaxel was not superior to dacarbazine. We conclude that further studies with the drug on an every 3-week schedule in melanoma are not warranted.

Application of scanning probe lithography to graphite patterning

We applied the scanning probe lithographic technique to a graphite patterning in air and analyzed the patterned sample with the lateral force microscopy and Raman spectroscopy. The local electric field generated from a tip caused either etching or oxidization depending on the electric field intensity in air. We have found that the frictional force between the tip and local oxidized graphite surface was increased remarkably from lateral force analysis. Also, it was found that the graphene layer was peeled from the graphite surface in the etching process, which could be a potential tool as a top-down nano-fabrication process for the graphene nano device without contamination.

Tailored lay health worker intervention improves breast cancer screening outcomes in non-adherent Korean-American women

Despite rapidly increasing incidence rates of breast cancer, recent immigrants such as Korean-American (KA) women report disproportionately lower utilization of screening tests compared with other ethnic groups. Early screening of breast cancer for this population may be greatly facilitated by indigenous lay health workers (LHWs). We conducted an intervention trial with a 6-month follow-up. Trained LHWs recruited 100 KA women 40 years of age or older who had not had a mammogram during the past 2 years. Ninety-three completed follow-up questionnaires. A 120-min, in-class education combined with LHW follow-up counseling and navigation assistance through the health care system was provided. Rates of breast cancer screening behaviors significantly increased at 6 months (P < 0.001); changes between pre- and post-intervention were 31.9% for mammography, 23% for clinical breast examination and 36.2% for breast self-examination. Modesty toward screening significantly decreased over time, but we did not find any significant differences in breast cancer knowledge and beliefs before and after the intervention. Results support the efficacy of this neighborhood-based, culturally sensitive intervention. Further research should seek to replicate these findings and to incorporate more self-care skills such as health literacy when designing an intervention program for linguistically and culturally isolated immigrant women.

Posttreatment occlusal variability among angle Class I nonextraction patients

OBJECTIVE

To test the hypothesis that variability among posttreatment Angle Class I, nonextraction patients is not related to patient and treatment factors.

MATERIALS AND METHODS

One hundred thirty-eight subjects were randomly selected from the archives of the Department of Orthodontics, St Louis University. Patient factors evaluated included age, sex, mandibular plane angle, and ANB angle; treatment factors included active treatment time and supervising orthodontist. Objective Grading System (OGS) scores for six of the criteria (excluding interproximal contacts and root angulations) and the anterior Bolton ratio were measured on the posttreatment study casts.

RESULTS

The partial mean overall OGS score was 24.9 +/- 8.0. Occlusal contact was the most important component contributing to the overall score, followed by alignment. Variation in the OGS scores was explained by sex, pretreatment mandibular plane and ANB angles, the posttreatment anterior Bolton ratio, and treatment duration. The partial overall OGS scores increased by approximately one point for every 4 degrees increase in the mandibular plane angle and nearly one point for every 3 additional months of treatment. Approximately 16% and 15% of the variation in alignment and buccolingual inclination, respectively, was due to the treating orthodontist.

CONCLUSIONS

Posttreatment occlusal variability among Class I nonextraction patients can be partially explained by patient- and treatment-related factors.

Evaluation of the training of Korean community health workers for chronic disease management

The use of community health workers (CHWs) or lay health advisors has been increasingly popular as an effective means of secondary prevention for cardiovascular health in hard-to-reach, underserved populations. Yet, published evaluations of the CHW training programs are rare. The purpose of this article is to report the results of an evaluation of a CHW training program for hypertension and diabetes management for Korean-American seniors. Forty-eight hours of training was developed and delivered to 12 Korean CHWs. Evaluation of the training program involved CHW surveys, trainer observation and debriefing and CHW focus groups. Testing of CHW knowledge showed that all CHWs met the minimum required knowledge level of 70%. Independent ratings by two trainer observations revealed that the overall CHW performance was satisfactory. Both CHW ratings and focus group data indicated that the training program met their expectation (average 9.3 on a 10-point scale) and was successful in empowering them to assume their role as a 'health initiator', 'health advertising agent' or 'health role model'. While this course is judged to be effective in general, future research is warranted to determine whether CHW provision of care and support will affect health outcomes in the target population.

Chronic myelomonocytic leukaemia after platinum-based therapy for non-small cell lung cancer: case report and review of the literature

Chronic myelomonocytic leukaemia (CMML) is a preleukaemic condition with myeloproliferative features, and classified as a part of myelodysplastic syndrome (MDS). Other than alkylating agents and topoisomerase II inhibitors, there is less evidence that chemotherapeutic drugs are associated with therapy-related CMML, acute leukaemia or MDS. We present a patient who developed CMML within 2 years of platinum-based chemotherapy for a metastatic non-small cell lung cancer. He received a cumulative dose of 240 mg/m(2) of cisplatin, and 1123 mg/m(2) of carboplatin before developing CMML. The cytogenetic study revealed trisomy 8. This is the first reported case that links platinum-based therapy with development of CMML with trisomy 8. Although the relationship between platinum therapy and the development of CMML is difficult to assess due to combinational nature of therapy in most cases, physicians should consider the possibility of CMML in patients with symptoms or signs suggestive of haematologic malignancy after platinum therapy.

Analysis of dense-medium light scattering with applications to corneal tissue: experiments and Monte Carlo simulations

Dense-medium scattering is explored in the context of providing a quantitative measurement of turbidity, with specific application to corneal haze. A multiple-wavelength scattering technique is proposed to make use of two-color scattering response ratios, thereby providing a means for data normalization. A combination of measurements and simulations are reported to assess this technique, including light-scattering experiments for a range of polystyrene suspensions. Monte Carlo (MC) simulations were performed using a multiple-scattering algorithm based on full Mie scattering theory. The simulations were in excellent agreement with the polystyrene suspension experiments, thereby validating the MC model. The MC model was then used to simulate multiwavelength scattering in a corneal tissue model. Overall, the proposed multiwavelength scattering technique appears to be a feasible approach to quantify dense-medium scattering such as the manifestation of corneal haze, although more complex modeling of keratocyte scattering, and animal studies, are necessary.

Plasma and urinary vascular endothelial growth factor and diabetic nephropathy in Type 2 diabetes mellitus

AIMS

Vascular endothelial growth factor (VEGF) has been implicated in the pathogenesis of diabetes mellitus. We determined whether alterations of plasma and urinary VEGF levels are related to diabetic nephropathy in Type 2 diabetic patients.

METHODS

One hundred and seven patients and 47 healthy controls were studied. Study subjects were divided into four groups using urinary albumin-to-creatinine ratio (ACR): a non-diabetic healthy control group (n = 47), a normoalbuminuric diabetic group (n = 37), a microalbuminuric diabetic group (n = 37) and an overt proteinuric diabetic group (n = 33). VEGF levels were measured by enzyme-linked immunosorbent assay.

RESULTS

(i) Urinary VEGF concentrations were significantly higher in the diabetic groups, even at the normoalbuminuric stage (log VEGF/Cr, normoalbuminuria; 4.33 +/- 1.06 vs. control; 3.53 +/- 0.79, P = 0.009). Urinary VEGF excretions increased as diabetic nephropathy advanced. (ii) Plasma and urinary VEGF levels were higher in hypertensive diabetic patients than in the normotensive individuals with diabetes. (iii) In those with diabetes, plasma VEGF levels were found to be positively correlated with plasma urea (r = 0.398, P = 0.039) and urinary ACR (r = 0.251, P = 0.044), and urinary VEGF to be positively correlated with urinary ACR (r = 0.645, P < 0.001), and creatinine (r = 0.336, P = 0.009), and to be negatively correlated with serum albumin (r = -0.557, P < 0.001). Urinary VEGF and serum creatinine were independently correlated with urinary ACR.

CONCLUSIONS

Urinary excretion of VEGF increased during the earlier stage of diabetic nephropathy and was significantly correlated with urinary albumin excretion. This suggests that urinary VEGF might be used as a sensitive marker of diabetic nephropathy and for predicting disease progression.

Plasma and urinary vascular endothelial growth factor and diabetic nephropathy in Type 2 diabetes mellitus

AIMS

Vascular endothelial growth factor (VEGF) has been implicated in the pathogenesis of diabetes mellitus. We determined whether alterations of plasma and urinary VEGF levels are related to diabetic nephropathy in Type 2 diabetic patients.

METHODS

One hundred and seven patients and 47 healthy controls were studied. Study subjects were divided into four groups using urinary albumin-to-creatinine ratio (ACR): a non-diabetic healthy control group (n = 47), a normoalbuminuric diabetic group (n = 37), a microalbuminuric diabetic group (n = 37) and an overt proteinuric diabetic group (n = 33). VEGF levels were measured by enzyme-linked immunosorbent assay.

RESULTS

(i) Urinary VEGF concentrations were significantly higher in the diabetic groups, even at the normoalbuminuric stage (log VEGF/Cr, normoalbuminuria; 4.33 +/- 1.06 vs. control; 3.53 +/- 0.79, P = 0.009). Urinary VEGF excretions increased as diabetic nephropathy advanced. (ii) Plasma and urinary VEGF levels were higher in hypertensive diabetic patients than in the normotensive individuals with diabetes. (iii) In those with diabetes, plasma VEGF levels were found to be positively correlated with plasma urea (r = 0.398, P = 0.039) and urinary ACR (r = 0.251, P = 0.044), and urinary VEGF to be positively correlated with urinary ACR (r = 0.645, P < 0.001), and creatinine (r = 0.336, P = 0.009), and to be negatively correlated with serum albumin (r = -0.557, P < 0.001). Urinary VEGF and serum creatinine were independently correlated with urinary ACR.

CONCLUSIONS

Urinary excretion of VEGF increased during the earlier stage of diabetic nephropathy and was significantly correlated with urinary albumin excretion. This suggests that urinary VEGF might be used as a sensitive marker of diabetic nephropathy and for predicting disease progression.

Relation between insulin resistance and hematological parameters in elderly Koreans-Southwest Seoul (SWS) Study

In this study, we investigated the relation between insulin resistance and hematological parameters in elderly Koreans. This study included 1314 non-diabetic subjects over the age of 60, selected from a cross-sectional study, which was conducted in 1999 in Seoul, Korea. We measured fasting and post-load 2 h plasma glucose, insulin levels, lipid profiles, anthropometric measures, and hematological parameters. The degree of insulin resistance was assessed using the homeostasis model assessment (HOMA). We found a correlation between insulin resistance and hemoglobin concentrations in non-smoking men (r=0.20, P=0.0186). In non-smoking women, insulin resistance correlated with hemoglobin (r=0.10, P=0.0017) and with white blood cell (WBC) count (r=0.15, P=0.001). Hemoglobin concentrations and WBC counts were also associated with other components of the insulin resistance syndrome such as body mass index, blood pressure, lipid profiles and fasting plasma insulin levels (surrogate for insulin resistance). Furthermore, the group in the upper quartile for insulin resistance showed higher hemoglobin concentrations and WBC counts than the lower quartile, independent of smoking status and serum iron concentrations. Using HOMA-IR as a dependent variable in a multiple regression analysis, age, body mass index (BMI), waist-to-hip ratio (WHR), systolic blood pressure, HDL cholesterol, triglyceride, WBC count, hemoglobin, hematocrit and serum TIBC were significant. Our results provide support for a relation between insulin resistance/hyperinsulinemia and hematological parameters such as hemoglobin concentrations and WBC counts in elderly Koreans. This suggests that increased erythropoiesis and subclinical inflammation could be part of the metabolic syndrome in elderly Koreans.

Selective inhibitors of the osteoblast proteasome stimulate bone formation in vivo and in vitro

We have found that the ubiquitin-proteasome pathway exerts exquisite control of osteoblast differentiation and bone formation in vitro and in vivo in rodents. Structurally different inhibitors that bind to specific catalytic beta subunits of the 20S proteasome stimulated bone formation in bone organ cultures in concentrations as low as 10 nM. When administered systemically to mice, the proteasome inhibitors epoxomicin and proteasome inhibitor-1 increased bone volume and bone formation rates over 70% after only 5 days of treatment. Since the ubiquitin-proteasome pathway has been shown to modulate expression of the Drosophila homologue of the bone morphogenetic protein-2 and -4 (BMP-2 and BMP-4) genes, we examined the effects of noggin, an endogenous inhibitor of BMP-2 and BMP-4 on bone formation stimulated by these compounds and found that it was abrogated. These compounds increased BMP-2 but not BMP-4 or BMP-6 mRNA expression in osteoblastic cells, suggesting that BMP-2 was responsible for the observed bone formation that was inhibited by noggin. We show proteasome inhibitors regulate BMP-2 gene expression at least in part through inhibiting the proteolytic processing of Gli3 protein. Our results suggest that the ubiquitin-proteasome machinery regulates osteoblast differentiation and bone formation and that inhibition of specific components of this system may be useful therapeutically in common diseases of bone loss.

Factor analysis of the metabolic syndrome among elderly Koreans--the South-west Seoul Study

AIMS

To examine the relationship between the components of the metabolic syndrome and to explore whether insulin resistance unifies the clustering of components of the metabolic syndrome among urban elderly Koreans using exploratory factor analysis.

METHODS

We included 1314 non-diabetic subjects over the age of 60 years, selected from a cross-sectional study, which was conducted in 1999 in Seoul, Korea. Factor analysis was carried out using the principle components analysis with Varimax orthogonal rotation of the components of the metabolic syndrome.

RESULTS

We found four major factors of cardiovascular disease risk variables in our study subjects. Impaired glucose tolerance, dyslipidaemia, hypertension and obesity aggregated as the major domain. Obesity and dyslipidaemia variables were closely related and loaded on the same factor. However, hypertension was not linked closely with other factors of the metabolic syndrome.

CONCLUSIONS

Insulin resistance is not the only contributor to the metabolic syndrome among urban elderly Koreans. Although the components of the metabolic syndrome were closely related, the finding of more than one factor suggests that more than one pathophysiological mechanism underlies full expression of the metabolic syndrome among elderly Koreans.

General pharmacological properties of YJA20379-8, a new H+/K(+)-ATPase inhibitor with anti-ulcer activities

The general pharmacological properties of YJA20379-8 (3-butyryl-4-[(R)-1-methylbenzylamino]-8-ethoxy-1,7-naphthyridine, CAS 187654-40-6), a new H+/K(+)-ATPase inhibitor with anti-ulcer activities, were investigated in mice, rats and guinea pigs. YJA20379-8 at oral doses of 25, 50 and 100 mg/kg did not affect the locomotor activity, hexobarbital hypnosis and motor coordination in mice. The drug did not have analgesic action and anticonvulsant action at the doses of 100 mg/kg p.o. The respiration and blood pressure were not affected at 10 mg/kg i.v. in rats. YJA20379-8 at 2 x 10(-4) g/ml did neither produce any contraction nor relaxation of isolated organs, such as guinea pig ileum, rat fundus, rat uterus and guinea pig vas deferens, and the drug antagonized the contractile responses to several spasmogens, such as acetylcholine, histamine, serotonin, L-phenylephrine, oxytocin and BaCl2. The drug up to 100 mg/kg p.o. did not affect pupil size and the intestinal propulsion of mice. And it did not show an anticarrageenan action at 100 mg/kg. In this general pharmacology study, hypothermic effect in mice, retardation in gastric emptying in rats, decreases in urine excretion in rats at oral doses of 50 and 100 mg/kg of YJA20379-8 and the spasmolytic activity could be found. However, no other effects were exhibited at a high oral dose of 100 mg/kg in animals in this study.

Prevalence and factors associated with high blood pressure in Korean Americans

This study, conducted from October 1998 to February 1999, included a cross-sectional epidemiological survey administered to Korean Americans (KAs) living in Maryland (N = 761). One third (32%) of participants had high blood pressure (HPB: SBP > or = 140 mm Hg and/or DBP > or = 90 mm Hg or were on hypertension medication). HBP was more common among males (35%) than females (30%) and those who were aged 50 years or older (53%) compared to those who were less than 50 years old (12%). The prevalence of HBP in Maryland KAs was found to be much higher than in other Americans (24%) and in their counterparts in Korea (22% overall: 29% in males, 11% in females). Only 40% of the hypertensive KAs were taking HBP medication, and 74% of those did not have controlled HBPs. Further, multivariate logistic analyses were conducted to estimate the relative biobehavioral risk factors related to hypertension. Several significant risk factors were identified, including family history of HBP, gender, level of education, level of acculturation, regular exercise, and being overweight. Findings from this study indicate that culturally relevant approaches to prevention and treatment of HBP are urgently needed to address the HBP problem in Korean Americans.

Off-pump coronary artery bypass may decrease the patency of saphenous vein grafts

BACKGROUND

There is concern that a hypercoagulable status is caused after coronary artery bypass grafting without cardiopulmonary bypass (off-pump coronary artery bypass grafting, or OPCAB) and may potentially endanger the patency of the anastomosis. The aims of this study were: (1) to compare 1-year graft patency after OPCAB with that of conventional coronary artery bypass grafting (CABG) and that of on-pump beating CABG; and (2) to demonstrate any differences in patency of various conduits among the three groups.

METHODS

We analyzed the results of 122 consecutive OPCAB cases (group 1) compared with those of 65 consecutive conventional CABG cases (group II) and those of 19 consecutive on-pump beating CABG cases (group III). In group I, coronary angiography (CAG) was performed immediately postoperatively and 1 year after surgery. In groups II and III, CAG was performed 1 year after surgery. Graft patency was graded as grade A (excellent), grade B (fair), or grade O (occluded).

RESULTS

The average number of distal anastomoses in groups I, II, and III were 3.1 +/- 1.1, 3.7 +/- 0.9, and 3.6 +/- 0.9, respectively. In group I, postoperative CAG was performed in 92% of patients (112/122) before discharge. The patency rate (grade A + B) was 96.4% (162/168) for arterial grafts, and 85.6% (160/187) for saphenous vein grafts (SVG). One-year follow-up CAG was performed in 74% of patients (90/122). The patency rate was 97.8% (132/135) for arterial grafts and 67.9% (106/156) for SVG. In group II, 1-year follow-up CAG was performed in 65% of patients (42/65). The patency rate (grade A + B) was 93.5% (43/46) for arterial grafts and 88.3% (98/111) for SVG. In group III, 1-year follow-up CAG was performed in 89% of patients (17/19). The patency rate (grade A + B) was 100% (19/19) for arterial grafts and 86.8% (33/38) for SVG.

CONCLUSIONS

Our results demonstrate that the patency rate ot SVG after OPCAB was significantly lower than that of arterial grafts in the early postoperative CAG (p < 0.001), and was also significantly lower than those of SVG of group II (p < 0.001) and group III (p < 0.01) in the postoperative 1-year CAG, although there was no significant difference in 1-year patency of arterial grafts among the three groups. Our data suggest that a specific perioperative anticoagulant therapy may be advisable in patients undergoing OPCAB with SVG.

Histological and neurotrophic changes triggered by varying models of bladder inflammation

PURPOSE

We determined whether bladder inflammation causes elevated expression of nerve growth factor by bladder parenchymal cells, leading to alterations in neurons innervating the bladder. To answer this question biochemical, histological and neuronal size data were obtained in rats following various experimental models of bladder inflammation.

MATERIALS AND METHODS

Chemical (2.5% formalin), immune (lipopolysaccharide 2 x 104 cfu/ml.) and mechanical (chromic catgut) inflammation was evaluated at various times and compared to control bladders. Hematoxylin and eosin, and Giemsa staining was done to characterize inflammation and quantify mast cells in the bladder. Nerve growth factor protein and messenger RNA were assayed in the bladder and major pelvic ganglion using 2-site enzyme-linked immunosorbent assay and reverse transcriptase-polymerase chain reaction, respectively. Retrograde axonal tracing was done to size bladder neurons in the major pelvic and dorsal root ganglia.

RESULTS

All forms of inflammation increased bladder weight and produced diffuse hyperplasia, intramural edema, acute and chronic inflammatory cells, infiltration and mastocytosis. Generally bladder inflammation resulted in a 50% increase in nerve growth factor and 52% to 58% enlargement of peripheral neurons.

CONCLUSIONS

Inflammation results in altered nerve growth factor content of the bladder, and morphological changes in sensory and motor neurons innervating the bladder. Such neuroplasticity may be a possible explanation for the association of bladder inflammation with long-term symptoms and pain after inflammation subsides.

Protacs: chimeric molecules that target proteins to the Skp1-Cullin-F box complex for ubiquitination and degradation

The intracellular levels of many proteins are regulated by ubiquitin-dependent proteolysis. One of the best-characterized enzymes that catalyzes the attachment of ubiquitin to proteins is a ubiquitin ligase complex, Skp1-Cullin-F box complex containing Hrt1 (SCF). We sought to artificially target a protein to the SCF complex for ubiquitination and degradation. To this end, we tested methionine aminopeptidase-2 (MetAP-2), which covalently binds the angiogenesis inhibitor ovalicin. A chimeric compound, protein-targeting chimeric molecule 1 (Protac-1), was synthesized to recruit MetAP-2 to SCF. One domain of Protac-1 contains the I kappa B alpha phosphopeptide that is recognized by the F-box protein beta-TRCP, whereas the other domain is composed of ovalicin. We show that MetAP-2 can be tethered to SCF(beta-TRCP), ubiquitinated, and degraded in a Protac-1-dependent manner. In the future, this approach may be useful for conditional inactivation of proteins, and for targeting disease-causing proteins for destruction.

FLASH coordinates NF-kappa B activity via TRAF2

FLASH is a protein recently shown to interact with the death effector domain of caspase-8 and is likely to be a component of the death-inducing signaling complex in receptor-mediated apoptosis. Here we show that antisense oligonucleotide-induced inhibition of FLASH expression abolished TNF-alpha-induced activation of NF-kappaB in HEK293 cells, as determined by luciferase reporter gene expression driven by a NF-kappaB responsive promoter. Conversely, overexpression of FLASH dose-dependently activated NF-kappaB, an effect suppressed by dominant negative mutants of TRAF2, NIK, and IKKalpha, and partially by those of TRAF5 and TRAF6. TRAF2 was co-immunoprecipitated with FLASH from the cell extracts of HEK293 cells or HeLa cells stably expressing exogenous FLASH (HeLa/HA-FLASH). Furthermore, serial deletion mapping demonstrated that a domain spanning the residues 856-1191 of FLASH activated NF-kappaB as efficiently as the full-length and could directly bind to TRAF2 in vitro and in the transfected cells. Taken together, these results suggest that FLASH coordinates downstream NF-kappaB activity via a TRAF2-dependent pathway in the TNF-alpha signaling.

The ubiquitin-proteasome pathway and proteasome inhibitors

The ubiquitin-proteasome pathway has emerged as a central player in the regulation of several diverse cellular processes. Here, we describe the important components of this complex biochemical machinery as well as several important cellular substrates targeted by this pathway and examples of human diseases resulting from defects in various components of the ubiquitin-proteasome pathway. In addition, this review covers the chemistry of synthetic and natural proteasome inhibitors, emphasizing their mode of actions toward the 20S proteasome. Given the importance of proteasome-mediated protein degradation in various intracellular processes, inhibitors of this pathway will continue to serve as both molecular probes of major cellular networks as well as potential therapeutic agents for various human diseases.

Intraaortic balloon pump therapy facilitates posterior vessel off-pump coronary artery bypass grafting in high-risk patients

BACKGROUND

Displacement of the heart to expose posterior vessels during coronary artery bypass grafting (CABG) without cardiopulmonary bypass (off-pump CABG, or OPCAB) may impair cardiac function. We used the intraaortic balloon pump (IABP) preoperatively to reduce operative risk and to facilitate posterior vessel OPCAB in high-risk patients with left main coronary artery disease (> 75% stenosis), intractable resting angina, postinfarction angina, left ventricular dysfunction (ejection fraction < 35%), or unstable angina.

METHODS

One hundred and forty-two consecutive patients who underwent multivessel OPCAB including posterior vessel revascularization were studied prospectively. The patients were divided into group I (n = 57), which received preoperative or intraoperative IABP, and group II (n = 85), which did not receive IABP. In group I, there were 34 patients with left main coronary artery disease, 24 patients with intractable resting angina, 8 patients with left ventricular dysfunction, 5 patients with postinfarction angina, and 40 patients with unstable angina. Seven patients received intraoperative IABP support owing to hemodynamic instability during OPCAB.

RESULTS

There was no operative mortality in group I and 1 death in group II. The average number of distal anastomoses was not different between group I and group II (3.4 +/- 0.9 versus 3.5 +/- 0.9, p = not significant). There were no significant differences in the number of posterior vessel anastomoses per patient. There were no differences in ventilator support time, length of stay in the intensive care unit, hospital stay, and morbidity between the two groups. There was one IABP-related complication in group I.

CONCLUSIONS

IABP therapy facilitates posterior vessel OPCAB in high-risk patients, and surgical results are comparable with those in lower-risk patients.

Recent advances in the management of squamous cell carcinoma of the head and neck

Therapeutic outcomes of the currently used chemotherapeutic agents for recurrent or advanced head and neck squamous cell carcinoma, such as methotrexate or a combination of 5-fluorouracil and cisplatin, are far beyond satisfaction. New chemotherapeutic agents, such as taxanes, paclitaxel and docetaxel, are among the most active drugs for head and neck cancer and a number of multidrug regimens containing a taxane and cisplatin have produced equivalent or higher response rates than conventional regimens. In addition, early clinical trials of novel molecular-targeted agents, such as epidermal growth factor receptors, tyrosine kinase inhibitors and gene targeted therapy, have shown encouraging results. Further clinical trials will be needed to optimally combine the biologic agents with chemotherapy and assess their effects on long-term control of cancer.

Cardiovascular disease risk factors in Korean American elderly

An in-depth cardiovascular risk factor assessment was carried out in a sample of 205 Korean American elderly in Maryland, consisting of 75 males and 130 females aged 60 to 89 years (mean age = 69.9 +/- 6.5 years). Six risk factors were assessed in each participant: high blood pressure, current smoking, high blood cholesterol, overweight, sedentary lifestyle, and diabetes. The findings of this cross-sectional study suggested that high blood pressure was the leading cardiovascular disease risk factor among Korean American elderly (71%), followed by high blood cholesterol (53%), overweight (43%), sedentary life style (24%), diabetes (18%), and smoking (7%). Two thirds of the sample had multiple cardiovascular disease risk factors. The pattern of prevalence and risk factors that was observed was consistent with the distribution of multiple risk factors in that the combination of high blood pressure, high blood cholesterol, and overweight was most common in Korean American elderly (62%). These findings indicate that culturally relevant and salient strategies are needed to reduce multiple risk factors in this population.

Postprandial hypertriglyceridemia impairs endothelial function by enhanced oxidant stress

AIMS

it appears that hypertriglyceridemia (HTG) is a risk factor of atherosclerosis as demonstrated by recent studies. In this study, we analyzed the effects of acute HTG on endothelial function and oxidative stress, which are important mechanisms in the pathogenesis of atherosclerosis.

METHODS AND RESULTS

in a high fat meal group (n = 11), serum triglycerides and PMA-activated leukocyte O(2)(-)* production were significantly (P < 0.005) increased from 146 +/- 69 mg/dl and 4.09 +/- 0.93 nmol/10(6) cells/min preprandially to 198 +/- 88 mg/dl and 5.49 +/- 1.19 nmol/10(6) cells/min, respectively, 2 h after eating a high-fat meal. The flow-mediated endothelium-dependent brachial artery dilation (FMD; high-resolution ultrasound) was decreased from 13.7 +/- 3.3% preprandially to 8.2 +/- 3.7%, 2 h after eating a high-fat meal (P < 0.005). However, following a low-fat meal (n = 9), there were no significant changes in triglycerides, leukocyte O(2)(-)* production and FMD. Changes of serum triglycerides were correlated negatively (r = -0.650, P < 0.005) with changes of FMD, but were correlated positively (r = 0.798, P < 0.001) with changes of leukocyte O(2)(-)* production, which - in turn - were correlated negatively (r = -0.784, P < 0.001) with changes of FMD in all study subjects (mean age: 56 years, n = 20).

CONCLUSIONS

this study suggests that acute HTG causes endothelial dysfunction via enhanced oxidant stress and this may pave the way for the development of atherosclerosis under chronic conditions.

Modifications of the Cox-Maze III procedure

BACKGROUND

The extended operative time needed for surgery with complicated atrial incisions may preclude application of the Cox-Maze III procedure (CM-III) as a concomitant operation. And after the CM-III, left atrial (LA) contraction has been reported to recover in reduced magnitude compared with right atrial (RA) contraction.

METHODS

To decrease operative time, we have modified the CM-III (modification I) by: obliterating the LA appendage instead of excising it; cryoablating the bridge between the LA appendage and margin of the pulmonary vein encircling incision; extending the lateral incision of RA onto the RA appendage without excising it, and extending the incision more inferiorly toward the inferior vena cava; and omitting the T-incision of RA. We compared the clinical results of the conventional CM-III (group 1, n = 18) with those of the modified CM-III group (group 2, n = 23) performed in patients with rheumatic mitral valve (MV) disease. To enlarge the contractile area of the LA, we modified the CM-III to encircle the right and left pulmonary veins separately (modification II), and compared the LA contractilities of the conventional CM-III (group A, n = 15) with those of the second modification (group B, n = 9).

RESULTS

Modification I: Mean aortic cross-clamp (ACC) times (135 +/- 29 versus 104 +/- 18 minutes, p < 0.005) and cardiopulmonary bypass (CPB) times (240 +/- 33 versus 185 +/- 42 minutes, p < 0.001) were significantly decreased in group 2 compared with those in group 1. In group 1, sinus rhythm was restored in 16 patients (88.9%). RA contractility was demonstrated in 100% of patients with sinus rhythm (16 of 16) and LA contractility in 75% (12 of 16) in the latest follow-up echocardiography. In group 2, sinus rhythm was restored in 21 patients (91.3%). RA contractility was demonstrated in 100% of patients with sinus rhythm (21 of 22) and LA contractility in 76.2% (16 of 21). Modification II: Mean ACC times were increased in group B compared with group A (133 +/- 32 versus 172 +/- 39 minutes, p = 0.02). The A velocities at LA contraction and the ratio of atrial contraction to peak early diastolic filling velocity (A/E ratio) of the trans-mitral flow were 0.14 +/- 0.20 m/sec and 0.23 +/- 0.11 in group A, and 0.58 +/- 0.33 m/sec and 0.47 +/- 0.19 in group B, respectively, both showing a significant increase in group B compared with group A (p < 0.05).

CONCLUSIONS

Our first modification of the CM-III showed comparable sinus conversion rates and incidence of atrial contractility restoration with significantly shorter ACC and CPB times than the conventional CM-III. The second modification of the CM-III significantly increased the LA contractility when compared with the conventional CM-III, although the second modification required a longer ACC time.

Transplacental transfer and age-related levels of serum IgG antibodies to the capsular polysaccharides of Streptococcus pneumoniae types 14 and 19 in Korea

Little is known about the prevalence of naturally acquired IgG antibodies to the capsular polysaccharides of Streptococcus pneumoniae (pneumococcal IgG) in Korea. In the present study, we investigated transplacental transfer and age-related levels of pneumococcal IgG to provide background seroepidemiologic data for S. pneumoniae in Korea. One hundred thirty eight sera were assayed by ELISA for IgG to pneumococcal polysaccharide capsular serotypes 14 and 19, the predominant serotypes for under 15 yr of age in Korea. The subjects were divided into 7 subgroups according to age. The cord/maternal geometric mean titer of pneumococcal were 4.47+/-5.88/5.21 +/- 5.88 for serotype 14, and 4.68 +/- 5.55/6.55 +/- 6.92 for serotype 1 9 (mean +/- standard deviation, microg/mL). After birth, the geometric mean titers of pneumococcal IgG for serotypes 14 and 19 expressed in microg/mL were 1.18+/-2.12 and 1.41+/-2.17 in the 0-6 months group, 0.27+/-0.19 and 0.69+/-0.93 in 7-12 months, 0.21+/-0.22 and 0.64+/-1.32 in 1-2 yr, 0.69+/-0.78 and 2.65+/-2.46 in 3-6 yr, 2.52+/-2.72 and 8.29+/-4.24 in 7-10 yr, respectively. In conclusion, reduced transplacental transfer and very low serum concentrations of pneumococcal IgG may contribute to the susceptibility of neonates, infants, and young children to S. pneumoniae infection.

Lack of proteasome active site allostery as revealed by subunit-specific inhibitors

The chymotrypsin-like (CT-L) activity of the proteasome is downregulated by substrates of the peptidyl-glutamyl peptide hydrolyzing (PGPH) activity. To investigate the nature of such interactions, we synthesized selective alpha',beta'-epoxyketone inhibitors of the PGPH activity. In cellular proliferation and protein degradation assays, these inhibitors revealed that selective PGPH inhibition was insufficient to inhibit protein degradation, indicating that the CT-L and PGPH sites function independently. We also demonstrated that CT-L inhibition by a PGPH substrate does not require the occupancy of the PGPH site or hydrolysis of the PGPH substrate. Thus, these results support a model in which a substrate of one subunit regulates the activity of another via binding to a noncatalytic site(s) rather than through binding to an active site.

Expression of thymidylate synthase in gastric cancer patients treated with 5-fluorouracil and doxorubicin-based adjuvant chemotherapy after curative resection

We evaluated the expression of thymidylate synthase (TS) in locally advanced gastric cancer patients treated with adjuvant chemotherapy after curative resection and investigated the association between TS expression and clinicopathologic characteristics including prognosis of the patients. TS expression was evaluated by immunohistochemical staining using TS106 monoclonal antibody in 103 locally advanced gastric cancer patients (stage IB-IV) who underwent 5-fluorouracil (5-FU) and doxorubicin-based adjuvant chemotherapy after curative resection. 65 patients (63%) had primary tumours with high TS expression (> or = 25% of tumour cells positive), and 38 patients (37%) demonstrated low TS expression (< 25% of tumour cells positive or no staining). High TS expression was associated with male gender (P = 0.002), poorly differentiated histology (P = 0.015), and mixed type in Lauren's classification (P = 0.027). There were no statistically significant differences in 4-year disease-free survival (60.0% vs. 57.2%, P = 0.548) and overall survival (59.6% vs. 59.3%, P = 0.792) between high-TS group and low-TS group. In conclusion, although high TS expression was associated with poorly differentiated histology and mixed type in Lauren's classification, it did not predict poor disease-free and overall survival in gastric cancer patients treated with 5-FU and doxorubicin-based adjuvant chemotherapy after curative resection. Further prospective studies including the evaluation of other biological markers associated with the resistance to 5-FU and doxorubicin are necessary.

Intracranial cerebral artery disease as a risk factor for central nervous system complications of coronary artery bypass graft surgery

BACKGROUND AND PURPOSE

Although extracranial carotid artery disease (ECAD) is accepted as a risk factor for central nervous system (CNS) complications after coronary artery bypass graft (CABG) surgery, it remains to be clarified whether intracranial cerebral artery disease (ICAD) may also increase the risk. We conducted a prospective study to elucidate the relation between ICAD and CNS complications after CABG surgery.

METHODS

We prospectively studied 201 patients undergoing nonemergency isolated CABG surgery during a 39-month period (from March 1995 to June 1998). Each patient was evaluated before surgery with neurological examination, transcranial Doppler, and carotid duplex ultrasonography. Magnetic resonance angiography was used to determine the presence and severity of ECAD and ICAD in patients with abnormal findings on clinical examination, carotid duplex ultrasonography, or transcranial Doppler. Patients were followed after surgery and evaluated for the development of CNS complications. Association between CNS complications and their potential predictors was analyzed.

RESULTS

One hundred nine patients (54.2%) were found to have ECAD and/or ICAD. ECAD alone was found in 48 patients (23.9%), ICAD alone in 33 (16.4%), and both ECAD and ICAD in 28 (13.9%). Fifty-one patients (25.4%) had single or multiple CNS complications: 23 (11.4%) had delirium; 18 (9.0%) had hypoxic-metabolic encephalopathy; 7 (3.5%) had stroke; and 7 (3. 5%) had seizure. In multivariate analysis, ICAD was found to have an independent association with the development of CNS complications (prevalence OR, 2.28; 95% CI, 1.04 to 5.01) after controlling for covariates including age, occurrence of intraoperative events, and reoperation. The joint effect of ECAD and ICAD was also statistically significant and stronger than ICAD alone (prevalence OR, 3.87; 95% CI, 1.80 to 6.52).

CONCLUSIONS

Our results suggest that ICAD may be an independent risk factor for CNS complications after CABG surgery. These results support pre-CABG evaluation of the intracranial arteries for the risk assessment of CABG surgery, at least in black and Asian patients, in whom there may be a higher prevalence of intracranial arterial stenosis.

Two cases of orbital infarction syndrome

Orbital infarction syndrome is defined as ischemia of all intraorbital and intraocular structures. It is a rare disease caused by rich anastomotic vascularization of the orbit. It can occur secondary to different conditions, such as, acute perfusion failure, systemic vasculitis, orbital cellulitis and vasculitis. It results in orbital and ocular pain, total ophthalmoplegia, anterior and posterior segment ischemia, and acute blindness. We report here upon two cases of orbital infarction with similar presentations but with different causes, namely, mucormycosis and as a postoperative complication of intracranial aneurysm, discuss the possible mechanisms of orbital infarction, and present a review of the literature on the topic. The prompt recognition of clinical pictures and rapid diagnosis is essential for the early treatment of orbital infarction, since its progression is very rapid and it can be even fatal.

Scanning electron microscopic analysis of arterial line filters used in cardiopulmonary bypass

The clinical value of arterial line filters is still a controversial issue. Proponents of arterial line filtration argue that filters remove particulate matter and undissolved gas from circulation while opponents argue the absence of conclusive clinical data. We conducted scanning electron microscope (SEM) studies of arterial line filters used clinically in the cardiopulmonary bypass circuits during adult cardiac surgery and analyzed the types and characteristics of materials entrapped in the arterial line filters. Twelve arterial line filters were obtained during routine hypothermic cardiopulmonary bypass in 12 adult cardiac patients. The arterial line filter was a screen type with a pore size of 40 microm (Baxter Health Care Corporation, Bentley Division, Irvine, CA, U.S.A. ). After opening the housing, the woven polyester strands were examined with SEM. All segments examined (120 segments, each 2.5 x 2. 5 cm) contained no embolic particles larger in their cross-sectional area than the pore size of the filter (40 microm). The origins of embolic particulates were mostly from environmental foreign bodies. This may suggest a possible need for more aggressive filtration of smaller particulates than is generally carried out at the present time.

Cadmium induces caspase-mediated cell death: suppression by Bcl-2

Apoptosis is a process of active cell death and is characterized by activation of caspases, DNA fragmentation, and biochemical and morphological changes. To better understand apoptosis, we have characterized the dose- and time-dependent toxic effects of cadmium in Rat-1 fibroblasts. Staining of cells with phosphatidylserine (PS)-annexin V, Hoechst 33258 or Rhodamine 123 and Tunel assays showed that incubating cells with 10 microM cadmium induced a form of cell death exhibiting typical characteristics of apoptosis, including cell shrinkage, externalization of PS, loss of mitochondria membrane potential, nuclear condensation and DNA fragmentation. Expression of Bcl-2 or CrmA each suppressed cadmium-induced cell death although Bcl-2 was somewhat more effective than CrmA. In vitro assay of caspase activity carried out using poly(ADP-ribose) polymerase (PARP) as a substrate as well as intracellular caspase assays using a fluorigenic caspase-3 substrate confirmed that caspase-3 is activated in Rat-1 cells undergoing cadmium-induced apoptosis. Both Asp-Glu-Val-Asp-aldehyde (DEVD-cho) and Tyr-Val-Ala-Asp-chloromethylketone (YVAD-cmk), selective inhibitors of caspase-3 and caspase-1, respectively, suppressed significantly cadmium-induced cell death. However, the nonselective caspase inhibitor, z-Val-Ala-Asp-floromethylketone (zVAD-fmk), was the most efficacious agent, almost completely blocking cadmium-induced cell death. Taken together, these results demonstrate that as in other forms of apoptosis, caspases play a central role in cadmium-induced cell death.

General pharmacological properties of YJA20379-2, a new antiulcer agent

The general pharmacological properties of YJA20379-2 2-dimethylamino-4,5-dihydrothiazolo[4,5:3,4]pyridol[1,2-a]++ +benzoimidazole, a novel proton pump inhibitor with antiulcer activities were investigated in mice, rats, guinea pigs and rabbits. YJA20379-2 at oral doses of 50, 100 and 200 mg/kg did not affect the general behaviour, hexobarbital hypnosis and motor coordination in mice. The drug did not have analgesic or anticonvulsant action at 200 mg/kg. Locomotor activity and body temperature were not influenced at 100 mg/kg. At a concentration up to 2 x 10(-4) g/ml, YJA20379-2 did not produce any contraction or relaxation of isolated preparations, such as the rat fundus, the guinea pig ileum and the rat uterus, and did not antagonize the contractile response to several spasmogens, such as histamine, acetylcholine, serotonin and oxytocin. At dosages up to 200mg/kg p.o. YJA20379-2 did not affect the pupil size of mice. Intestinal propulsion of mice was not affected up to 200 mg/kg p.o. and the drug did not affect urinary excretion at 100 mg/kg p.o. These results indicate that at dosages up to 100 mg/kg p.o. YJA20379 was found not to affect this pharmacological profile. However, at 200 mg/kg the drug lowered body temperature and showed decreases in locomotor activity and urine volume.

Proteasome inhibition by the natural products epoxomicin and dihydroeponemycin: insights into specificity and potency

While two structurally related epoxyketone-containing antitumor natural products, epoxomicin and eponemycin, share the proteasome as a common intracellular target, they differ in their antiproliferative activity, proteasome subunit binding specificity, and rates of proteasome inhibition. As a first step towards understanding such differences and developing novel proteasome subunit-specific inhibitors, we report here the synthesis and characterization of epoxomicin/dihydroeponemycin chimerae.

Biochemical and pharmacological characteristics of a newly synthesized H+/K+-ATPase inhibitor, YJA20379-8, 3-butyryl-4-[R-1-methylbenzylamino]-8-ethoxy-1,7-naphthyridine, in pigs and rats

We have investigated the effect of the newly synthesized proton-pump inhibitor YJA20379-8, 3-butyryl-4-[R-1-methylbenzylamino]-8-ethoxy-1,7-naphthyridine, on gastric mucosal proton pump (H+/K+-ATPase) activity, gastric acid secretion and gastric lesions in experimental animals. In lyophilized pig gastric microsomes, YJA20379-8 was shown to inhibit H+/K+-ATPase activity; the inhibitory effect was not affected by pH, the IC50 (dose resulting in 50% inhibition) being 28.0 microM and 30.0 microM at pH 6.4 and pH 7.4, respectively. The effect was fully reversed by dilution and subsequent washing of the incubation mixtures of H+/K+-ATPase and YJA20379-8, suggesting the reversible nature of the enzyme inhibition. In pylorus-ligated rats, YJA20379-8 administered by different routes (intraduodenal, subcutaneous, intravenous or oral) resulted in dose-dependent suppression of basal gastric acid secretion. The duration of antisecretory action of 30 mg kg(-1) YJA20379-8 given intraduodenally was very brief (less than 7 h). Pretreatment with YJA20379-8 also dose-dependently prevented gastric lesions induced by absolute ethanol and water-immersion stress in rats. These results suggest that YJA20379-8 might exert its antiulcer activity partly by reversible suppression of acid secretion and partly by protecting the gastric mucosa against ulcerative stimuli.

General pharmacological properties of YJA 20379-1, a novel proton pump inhibitor with antiulcer activities

The general pharmacological properties of YJA 20379-1 (2-amino-4,5-dihydro-8-phenylimidazo[2,1-b]thiazolo[4,5-g]benzo thi azole), a novel proton pump inhibitor with antiulcer activities, were investigated in mice, rats, guinea pig and rabbits. YJA 20379-1 at oral doses of 50, 100 and 200 mg/kg did not affect the general behaviour, hexobarbital hypnosis, motor coordination and body temperature in mice. The drug does not have analgesic and anticonvulsant action at 200 mg/kg p.o. The locomotor activity was not affected at 100 mg/kg p.o., but at 200 mg/kg, the activity was suppressed. YJA 20379-1 (at 2 x 10(-4) g/ml) did neither produce any contraction nor relaxation of isolated organs such as rat fundus, rat uterus, guinea pig ileum and guinea pig vas deferens, and the drug did not antagonize the contractile response to several spasmogens, such as histamine, acetylcholine, serotonin and oxytocin, and the drug up to 200 mg/kg p.o. did not affect pupil size of mice. The intestinal propulsion in mice was not affected up to 200 mg/kg p.o. The gastric emptying in rats was not affected at 100 mg/kg p.o., even if retardation in gastric emptying occurred at 200 mg/kg. YJA 20379-1 did not show anti-inflammatory action nor did it affect urinary excretion up to 200 mg/kg p.o. From these results, it is suggested that YJA 20379-1 at the high dose of 100 mg/kg p.o. may not exert any adverse effects.

The Cox-Maze III procedure for atrial fibrillation associated with rheumatic mitral valve disease

BACKGROUND

The surgical results of the Cox-Maze III procedure (CM-III) for atrial fibrillation (AF) associated with rheumatic mitral valve (MV) disease are not as good as the results from surgery for AF alone.

METHODS

To assess the efficacy and safety of the CM-III in AF associated with rheumatic MV disease, we retrospectively analyzed 75 patients who underwent the CM-III combined with a rheumatic MV procedure between April 1994 and December 1997. Fourteen cases were reoperations because of prosthetic valve failure.

RESULTS

Mean aortic cross-clamp (ACC) times and cardiopulmonary bypass (CPB) times were 151+/-43 and 251+/-73 min, respectively. Concomitant procedures were mitral valve replacement (MVR) in 25 patients, MVR and aortic valve replacement (AVR) in 14 patients, MV repair in 10 patients, MVR and tricuspid annuloplasty (TAP) in 6 patients, MVR and AV repair in 3 patients, MVR and coronary artery bypass grafting (CABG) in 2 patients, MVR and AVR and CABG in 1 patient, redo-MVR in 8 patients, redo-MVR and TAP in 4 patients, and redo-MVR and redo-AVR in 2 patients. There were two in-hospital mortalities (2 of 75, 2.7%). Seventy-three survivors were followed for a mean duration of 30+/-13 months (12-56 months). Normal sinus rhythm was restored in 90.4% (66 of 73). Three patients remained in AF and 2 patients were in junctional rhythm. Permanent pacemakers were implanted in 2 patients due to sick sinus syndrome. Right atrial (RA) contractility was demonstrable in 100% (66 of 66) and left atrial (LA) contractility in 62.1% (41 of 66) of the patients in the latest follow-up echocardiography. RA and LA contractilities were restored a mean 69+/-93 and 126+/-136 days after the operation, respectively. LA contractility was restored significantly later at a lower rate than RA contractility in rheumatic MV disease. There were no differences in ACC time, CPB time, incidence of postoperative bleeding complications, and sinus conversion rates between non-redo and redo cases in spite of the significantly longer duration of preoperative AF in redo cases (p<0.05).

CONCLUSIONS

The CM-III for AF associated with rheumatic MV disease demonstrated a high sinus conversion rate with acceptable operative risk even in cases of reoperation.