The efficacy of immune checkpoint inhibitors in elderly patients: a meta-analysis and meta-regression

Background

Immune checkpoint inhibitor (ICI) therapy has improved patient survival in advanced cancers; however, the efficacy of ICIs in elderly patients is still elusive. This study assessed the efficacy of ICIs in elderly patients with advanced cancer in terms of overall survival (OS) and progression-free survival (PFS).

Materials and methods

We carried out a systematic review and identified 30 head-to-head phase II/III randomized controlled trials that compared immunotherapy with the standard of care in advanced solid tumor patients. The data on patients younger or over 65 years of age were indexed from PubMed-Medline, Embase, and Scopus and obtained for meta-analysis. The subgroup analyses were stratified by primary tumor type, line of treatment, or type of immunotherapy, and a meta-regression analysis was carried out after adjusting for all other variables.

Results

The study included 17 476 patients, comprising 58% (10 119) younger (<65 years old) and 42% (7357) elderly (≥65 years old) patients. The hazard ratio (HR) for OS was 0.77 [95% confidence interval (CI) 0.70-0.85] and 0.77 (95% CI 0.70-0.85) in the younger and elderly groups, respectively, suggesting similar efficacies of ICIs in these two age groups. The subgroup analyses revealed no significant relationship between age and treatment outcomes, except for the PFS benefit in younger patients with melanoma than in elderly patients (HR 0.44 in younger patients versus 0.65 in elderly patients, P = 0.04). These results were further supported by meta-regression analysis, which showed no statistically significant difference in OS (P = 0.954) and PFS (P = 0.555) between the two age groups.

Conclusions

The findings suggest that age-associated impairments of the immune system did not affect the efficacy of ICIs in elderly patients compared to younger patients. Therefore, the choice of ICIs for elderly patients can be considered, regardless of chronological age.

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We evaluated the efficacy of ICI in 17 476 patients, comprising 58% younger and 42% elderly patients.

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Meta-analysis resulted in the comparable efficacy of ICI between younger and older age groups.

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Further, meta-regression analysis showed no significant difference in OS and PFS.

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Our study suggests that chronological age does not lead to immunosenescence in response to ICI in immune-oncology.

Silver nanoparticles induce Egr-1-dependent psoriasin expression via the ERK and p38 pathways

BACKGROUND

Silver nanoparticles (Ag-NPs) can prevent bacterial infection and improve cutaneous wound healing owing to their antimicrobial activity. However, the mechanism of their antimicrobial activity is poorly understood.

AIM

To determine the mechanistic relationship between Ag-NP treatment and expression of psoriasin.

METHODS

Human epidermal keratinocytes, neonatal (HEKn) were used. Psoriasin mRNA expression was measured by reverse transcription PCR and real-time PCR. Western blotting was performed to verify expression of early growth response-1 (Egr-1) and psoriasin, and phosphorylation of mitogen-activated protein kinase (MAPK). Psoriasin promoter activity by Egr-1 was detected by a luciferase assay.

RESULTS

Treatment of HEKn with Ag-NPs induced psoriasin mRNA and protein expression. Upregulation of psoriasin promoter activity was also observed in the luciferase assay. Ag-NPs increased Egr-1 expression, promoter activity and nuclear translocation in HEKn. Psoriasin luciferase activity was increased in HEKn transfected with Egr-1 pcDNA 3.1. Ag-NPs activated MAPK pathways including the extracellular signal-regulated kinase (ERK), p38, and c-Jun-N-terminal kinase (JNK) pathways. The upregulation of Egr-1 expression by Ag-NP stimulation was inhibited by ERK and p38 inhibitors, but not by a JNK inhibitor. Psoriasin expression was reduced in Egr-1 small interfering RNA-transfected HEKn.

CONCLUSIONS

Ag-NP treatment induces upregulation of psoriasin expression through Egr-1 expression. We suggest that the ERK and p38 pathways are involved in Egr-1-dependent psoriasin expression.

Ceramic molar crown reproducibility by digital workflow manufacturing: An in vitro study

PURPOSE

This in vitro study aimed to analyze and compare the reproducibility of zirconia and lithium disilicate crowns manufactured by digital workflow.

MATERIALS AND METHODS

A typodont model with a prepped upper first molar was set in a phantom head, and a digital impression was obtained with a video intraoral scanner (CEREC Omnicam; Sirona GmbH), from which a single crown was designed and manufactured with CAD/CAM into a zirconia crown and lithium disilicate crown (n=12). Reproducibility of each crown was quantitatively retrieved by superimposing the digitized data of the crown in 3D inspection software, and differences were graphically mapped in color. Areas with large differences were analyzed with digital microscopy. Mean quadratic deviations (RMS) quantitatively obtained from each ceramic group were statistically analyzed with Student's t-test (α=.05).

RESULTS

The RMS value of lithium disilicate crown was 29.2 (4.1) µm and 17.6 (5.5) µm on the outer and inner surfaces, respectively, whereas these values were 18.6 (2.0) µm and 20.6 (5.1) µm for the zirconia crown. Reproducibility of zirconia and lithium disilicate crowns had a statistically significant difference only on the outer surface (P<.001). The outer surface of lithium disilicate crown showed over-contouring on the buccal surface and under-contouring on the inner occlusal surface. The outer surface of zirconia crown showed both over- and under-contouring on the buccal surface, and the inner surface showed under-contouring in the marginal areas.

CONCLUSION

Restoration manufacturing by digital workflow will enhance the reproducibility of zirconia single crowns more than that of lithium disilicate single crowns.

Evaluation of marginal and internal gaps of Ni-Cr and Co-Cr alloy copings manufactured by microstereolithography

PURPOSE

The purpose of this study was to evaluate the marginal and internal gaps of Ni-Cr and Co-Cr copings, fabricated using the dental µ-SLA system.

MATERIALS AND METHODS

Ten study dies were made using a two-step silicone impression with a dental stone (type IV) from the master die of a tooth. Ni-Cr (NC group) and Co-Cr (CC group) alloy copings were designed using a dental scanner, CAD software, resin coping, and casting process. In addition, 10 Ni-Cr alloy copings were manufactured using the lost-wax technique (LW group). The marginal and internal gaps in the 3 groups were measured using a digital microscope (160 ×) with the silicone replica technique, and the obtained data were analyzed using the non-parametric Kruskal-Wallis H test. Post-hoc comparisons were performed using Bonferroni-corrected Mann-Whitney U tests (α=.05).

RESULTS

The mean (±standard deviation) values of the marginal, chamfer, axial wall, and occlusal gaps in the 3 groups were as follows: 81.5±73.8, 98.1±76.1, 87.1±44.8, and 146.8±78.7 µm in the LW group; 76.8±48.0, 141.7±57.1, 80.7±47.5, and 194.69±63.8 µm in the NC group; and 124.2±52.0, 199.5±71.0, 67.1±37.6, and 244.5±58.9 µm in the CC group.

CONCLUSION

The marginal gap in the LW and NC groups were clinically acceptable. Further improvement is needed for CC group to be used clinical practice.

Evaluation of accuracy and repeatability using CBCT and a dental scanner by means of 3D software

OBJECTIVE

The objective of the present study was to compare and evaluate the accuracy of three-dimensional (3D) image data acquired from cone beam computed tomography (CBCT) and a dental scanner using 3D software.

MATERIALS AND METHODS

After selecting the full-arch forms of the maxilla and mandible as the master cast, the master cast was scanned via a high-precision optical scanner for use as master model data. The model was scanned 12 times each using CBCT and a dental scanner. Scanned data were superimposed onto the master cast data for evaluation of accuracy and repeatability.

RESULTS

Although significant differences in both accuracy and repeatability were seen between CBCT and dental scanner (P < 0.05), repeatability of the maxillary arch showed little difference, with CBCT and scanner having values of 17 ± 2 µm and 22 ± 5 µm, respectively. Meanwhile, repeatability of the mandibular arch with CBCT and scanner was 15 ± 0 µm and 19 ± 3 µm, respectively. Since good repeatability was shown, this demonstrated that data can be stably acquired.

CONCLUSIONS

The present study demonstrated the feasibility of using a dental scanner to create a digital model as a substitute for a plaster model for use in orthodontic diagnosis and device fabrication.

Trueness of milled prostheses according to number of ball-end mill burs

STATEMENT OF PROBLEM

Making a computer-aided design/computer-aided manufacturing (CAD/CAM) prosthesis with a milling machine often requires 2 (2- and 1-mm diameter) or 3 (2-, 1-, and 0.6-mm diameter) burs; however, using 3 burs can reduce time effectiveness and increase cost. Studies evaluating the trueness of prostheses made with 2 and 3 burs are lacking.

PURPOSE

The purpose of this in vitro study was to evaluate the 3-dimensional trueness of crown prostheses made using 2 and 3 ball-end mill burs in the milling process.

MATERIAL AND METHODS

The abutment die of the maxillary right first molar for ceramic crowns was designed with computer-aided design software. After the crown prosthesis design was completed, polyurethane blocks were milled using 2 and 3 burs with a 5-axis milling machine. The outer and inner surfaces of the milled crown prostheses were scanned with a dental scanner. The inner part was separated into a marginal part and an internal part using 3-dimensional evaluation software. The 3-dimensional trueness of the prostheses milled with 2 or 3 burs was compared.

RESULTS

No significant differences in trueness were found for the inner or internal parts of the prosthesis (P>.05). However, the outer and marginal parts of the prosthesis did show significant differences in trueness (P<.05).

CONCLUSIONS

Milling the marginal part of the inner prosthesis was better with 2 burs, whereas milling the outer part was better with 3 burs.

Speckle statistics and transverse coherence of an x-ray laser with fluctuations in its active medium

It is shown that the statistics of the intensity distribution in the output beam of a collisional X-ray laser, analysed in terms of the degree of freedom or equivalently the number of the coherence modes in the beam cross-section, has non-Gaussian character. The non-Gaussian character seems to be caused by the small-scale plasma/medium fluctuations. It was assumed that these overlap the modal structure imposed by the geometry of the medium and considered as equivalent to a large-scale inhomogeneity. Thus, the fluctuations decide about the character of the output beam transverse coherence. It is also shown that the relevant to this model compound statistics of the intensity fluctuations in the output beam is well described by the m-m-distribution, a specific form of the K-distribution. The deviation from the Gaussian statistics was confirmed by the field correlation function at the laser exit plane, retrieved from the experimental data.

Interaction of hydrogen with ZnO: surface adsorption versus bulk diffusion

The interaction of hydrogen (H) and a ZnO(0001)-O surface has been investigated using a temperature programmed desorption (TPD) technique. When the surface is exposed to atomic hydrogen below 400 K, hydrogen is adsorbed on the surface. As the hydrogen exposure increases, bulk diffusion of hydrogen takes place. The existence of surface and bulk hydrogen has been confirmed using X-ray photoelectron spectroscopy (XPS). When the ZnO surface dosed with hydrogen is heated, surface hydrogen is desorbed at 432 K and bulk hydrogen is evolved at ∼539 K. Diffusion of hydrogen into the ZnO bulk is an activated process, and the activation energy is estimated to be 0.19 eV.

Role of the precursor in a triple-pulse pumping scheme of a nickel-like silver soft-x-ray laser in the grazing-incidence-pumping geometry

Soft x-ray lasers pumped in the grazing incidence geometry show strongly reduced energetic needs but hardly changed conversion efficiency between the pump energy and the output short-wavelength radiation. Numerical analysis presented in the paper concerns with performance of a Ni-like Ag soft-x-ray laser pumped by a triple-pulse structure in the grazing incidence geometry as a function of the puming conditions. It was found that a weak precursor preceding the main preforming and heating pulses by a few nanoseconds is crucial for the energy deposition. Its presence enables in different arrangements a reasonable reduction in the pump energy and relaxation of the steep density gradients as well as a control over partition of the deposited energy. As a consequence, it was concluded that a well energetically balanced three- or multipulse composition seems to be a reasonable way to achieve performance improvement.

Ion spectrometer composed of time-of-flight and Thomson parabola spectrometers for simultaneous characterization of laser-driven ions

An ion spectrometer, composed of a time-of-flight spectrometer (TOFS) and a Thomson parabola spectrometer (TPS), has been developed to measure energy spectra and to analyze species of laser-driven ions. Two spectrometers can be operated simultaneously, thereby facilitate to compare the independently measured data and to combine advantages of each spectrometer. Real-time and shot-to-shot characterizations have been possible with the TOFS, and species of ions can be analyzed with the TPS. The two spectrometers show very good agreement of maximum proton energy even for a single laser shot. The composite ion spectrometer can provide two complementary spectra measured by TOFS with a large solid angle and TPS with a small one for the same ion source, which are useful to estimate precise total ion number and to investigate fine structure of energy spectrum at high energy depending on the detection position and solid angle. Advantage and comparison to other online measurement system, such as the TPS equipped with microchannel plate, are discussed in terms of overlay of ion species, high-repetition rate operation, detection solid angle, and detector characteristics of imaging plate.

Risk factors for pelvic organ prolapse

OBJECTIVES

To evaluate the risk factors for pelvic organ prolapse (POP) and to determine the relationship between these risk factors and stage or other components of POP.

METHODS

244 patients with primary POP and 314 women without POP were included. Age, parity, smoking, body mass index (BMI), menopause, and hormone replacement therapy (HRT) were investigated.

RESULT

Independent risk factors for POP included age over 70, parity higher than 3, and menopause. Age, parity, menopause, and HRT were significantly associated with stage of POP. Genital hiatus (GH) and perineal body (PB) showed a significant positive and negative correlation with age and parity, respectively. Menopause and HRT were also associated with them.

CONCLUSION

Age, parity and menopause are possible risk factors of POP and associated with the lengths of GH and PB in POP women. Further, these risk factors and HRT are significantly correlated with the severity of the disease.

Post-marketing surveillance study of the efficacy and safety of vardenafil among patients with erectile dysfunction in primary care

To evaluate the safety and efficacy of vardenafil in primary care, we undertook a post-marketing surveillance study in 384 men with erectile dysfunction (ED), enrolled by 22 family physicians in Korea, from July 2004 to August 2005. Of the 384 patients enrolled, 343 (89.3%) returned for efficacy assessment and safety evaluation. Among the latter, 279 patients (81.3%) reported that their erectile function improved, 292 (92.1%) showed enhanced IIEF (International Index of Erectile Function)-5 scores and 265 (77.9%) responded that they were 'very satisfied' or 'satisfied' with vardenafil treatment. The most frequent reason for patient satisfaction with vardenafil was erectile potency (62.4%), followed by safety (42.4%), rapid onset (35.3%), adequate duration of efficacy (28.5%) and easy administration (25.9%). A total of 23 adverse events were observed in 18 patients, with the most frequent being hot flushes (3.2%), followed by headache (1.2%), nasal congestion (0.6%), color vision disturbance (0.3%), dizziness (0.3%), dry mouth (0.3%), dyspepsia (0.3%), nausea (0.3%) and diarrhea (0.3%). Only one patient discontinued vardenafil as a direct result of an adverse event. These results suggest that vardenafil prescribed by primary care physicians improved erectile function and was well tolerated by patients with ED.

Increased telomerase activity and human telomerase reverse transcriptase mRNA expression in the endometrium of patients with endometriosis

BACKGROUND

Endometriosis is considered a frequent, benign disease with the ability to undergo neoplastic processes. The aim of this study was to evaluate the limitless replication potential of the endometrium in patients with endometriosis by examining human telomerase reverse transcriptase (hTERT) mRNA expression and telomerase activity.

METHODS

Endometrium samples from 30 endometriosis patients and 30 patients without endometriosis were obtained via endometrial biopsy. The expression of hTERT mRNA was determined by real-time RT-PCR assay, and telomerase activity was measured by telomerase repeat amplification protocol (TRAP) assay.

RESULTS

The mean normalized hTERT (N hTERT) mRNA level was significantly higher in the endometriosis than in the control group (P = 0.013). The mean hTERT mRNA levels during the proliferative phase and during the secretory phase were higher in the endometriosis group than in the control group, although the difference was only significant for the secretory phase (P = 0.036). We found a prominent difference in endometrial telomerase activity between moderate-to-severe endometriosis and the control group (P = 0.048). The levels of hTERT mRNA and telomerase activity increased as the disease became more severe (P = 0.038, P = 0.016).

CONCLUSIONS

This study showed the overexpression of hTERT mRNA and telomerase activity in the endometrium of endometriosis patients. These finding suggest that replication potential of endometrial cells may have an important role in the pathogenesis of endometriosis.

Synergistic antinociception between zaprinast and morphine in the spinal cord of rats on the formalin test

BACKGROUND AND OBJECTIVE

The cyclic guanosine monophosphate level, which causes an antinociception, is increased in cells as a direct result of phosphodiesterase inhibition. This study used a nociceptive test to examine the nature of the pharmacological interaction between intrathecal zaprinast, a phosphodiesterase inhibitor, and morphine.

METHODS

Catheters were inserted into the intrathecal space through an incision in the atlantooccipital membrane of male Sprague-Dawley rats. As a nociceptive model, 50 microL of a 5% formalin solution was injected into the hind paw. After observing the effect of zaprinast (37, 111, 369 nmol) and morphine (1, 4, 10, 40 nmol) alone, the interactions of their combination were examined by an isobolographic analysis.

RESULTS

Intrathecal zaprinast (P < 0.05) and morphine (P < 0.05) dose-dependently suppressed the flinching observed during phase 1 and phase 2 in the formalin test. The ED50 values (95% confidence intervals) of zaprinast and morphine in phase 1 were 161.9 (87.9-298.3) and 11.6 nmol (4.8-27.9 nmol), respectively. The phase 2 ED50 values (95% confidence intervals) of zaprinast and morphine were 229.9 (142.5-370.9) and 3.9 nmol (1.9-7.6 nmol), respectively. Isobolographic analysis revealed a synergistic interaction after intrathecal delivery a zaprinast-morphine mixture in both phases. The ED50 values of (95% confidence intervals) zaprinast in the combination of zaprinast with morphine in phase 1 and phase 2 were 14.2 (4.9-40.6) and 10.4 nmol (3-35.9 nmol), respectively.

CONCLUSIONS

Intrathecal zaprinast and morphine are effective against acute pain and facilitated pain state. Zaprinast interacts synergistically with morphine.

Phosphodiesterase: overview of protein structures, potential therapeutic applications and recent progress in drug development

Phosphodiesterases (PDEs) are essential regulators of cyclic nucleotide signaling with diverse physiological functions. Because of their great market potential and therapeutic importance, PDE inhibitors became recognized as important therapeutic agents in the treatment of various diseases. Currently, there are seven PDE inhibitors on the market, and the pharmacological and safety evaluations of many drug candidates are in progress. Three-dimensional (3D) structures of catalytic domains of PDE 1, -3, -4, -5 and -9 in the presence of their inhibitors are now available, and can be utilized for rational drug design. Recent advances in molecular pharmacology of PDE isoenzymes resulted in identification of new potential applications of PDE inhibitors in various therapeutic areas, including dementia, depression and schizophrenia. This review will describe the latest advances in PDE research on 3D structural studies, the potential of therapeutic applications and the development of drug candidates.

CO−NO and CO−O2 Interactions on Cu(100) between 25 and 200 K Studied with Infrared Reflection Absorption Spectroscopy

Infrared reflection absorption spectroscopy (IRAS) has been used to study CO-NO and CO-O(2) interactions on Cu(100) between 25 and 200 K. A strong repulsive interaction between CO and NO on Cu(100) at 25 K causes tilting of the CO molecules away from the surface normal and a blue-shift of the CO vibrational frequency. Upon warming and decomposition of the NO, the CO molecules return to a bonding position normal to the surface plane. The vibrational frequency of CO blue-shifts from 2087 to 2136 cm(-1) upon coadsorption with N and O atoms formed from NO decomposition. On the other hand, the interaction of CO with O(2) at 27 K on Cu(100) in the submonolayer regime induces a red-shift of the CO vibrational frequency. Atomic oxygen, formed on Cu(100) by dissociation of O(2) at 95 K, induces a blue-shift of the vibrational frequency of coadsorbed CO to 2116 cm(-1). The CO vibrational frequency shifts to 2091 cm(-1) when the surface is annealed to 140 K, implying a change in the adsorption geometry of the oxygen atoms on Cu(100).

Level walking and ambulatory capacity in persons with incomplete spinal cord injury: relationship with muscle strength

STUDY DESIGN

Prospective analysis of relationships.

OBJECTIVES

(1) To quantify the relationship between individual lower extremity muscle strength and functional walking measures and (2) to determine whether a multiple regression model incorporating lower extremity muscle strength could predict the performance of functional walking measures in persons with incomplete spinal cord injury (ISCI) living in the community.

SETTING

Tertiary rehabilitation center, Vancouver, Canada.

METHODS

In all, 22 subjects with ISCI participated. The relationship between functional walking measures (gait speed, 6-min-walk distance, and ambulatory capacity) and muscle strength (manual tests of hip flexors/extensors/abductors, knee flexors/extensors, ankle dorsiflexors/plantarflexors, and great toe extensors) were measured by Pearson's correlation and regression procedures.

RESULTS

For both the more and less affected sides, hip flexors, hip extensors, and hip abductors produced the highest correlations with the three functional measures. The less affected hip flexor strength explained more than 50% of the variance in gait speed and 6-min-walk distance while the less affected hip extensor strength explained up to 64% of the variance in ambulatory capacity. For all three functional measures, the strength of the less affected limb was more important than that of the more affected limb.

CONCLUSIONS

Lower extremity muscle strength, in particular that of hip flexors, hip extensors, and hip abductors, is an important determinant of functional walking performance.

Survey of nitrate and nitrite contents of vegetables grown in Korea

A scientific basis for the evaluation of the risk to public health arising from excessive dietary intake of nitrate in Korea is provided. The nitrate () and nitrite () contents of various vegetables (Chinese cabbage, radish, lettuce, spinach, soybean sprouts, onion, pumpkin, green onion, cucumber, potato, carrot, garlic, green pepper, cabbage and Allium tuberosum Roth known as Crown daisy) are reported. Six hundred samples of 15 vegetables cultivated during different seasons were analysed for nitrate and nitrite by ion chromatography and ultraviolet spectrophotometry, respectively. No significant variance in nitrate levels was found for most vegetables cultivated during the summer and winter harvests. The mean nitrates level was higher in A. tuberosum Roth (5150 mg kg(-1)) and spinach (4259 mg kg(-1)), intermediate in radish (1878 mg kg(-1)) and Chinese cabbage (1740 mg kg(-1)), and lower in onion (23 mg kg(-1)), soybean sprouts (56 mg kg(-1)) and green pepper (76 mg kg(-1)) compared with those in other vegetables. The average nitrite contents in various vegetables were about 0.6 mg kg(-1), and the values were not significantly different among most vegetables. It was observed that nitrate contents in vegetables varied depending on the type of vegetables and were similar to those in vegetables grown in other countries. From the results of our studies and other information from foreign sources, it can be concluded that it is not necessary to establish limits of nitrates contents of vegetables cultivated in Korea due to the co-presence of beneficial elements such as ascorbic acid and alpha-tocopherol which are known to inhibit the formation of nitrosamine.

Reconsideration of intermittent synchronization in coupled chaotic pendula

We reinvestigate the intermittent synchronization phenomenon of coupled chaotic pendula that has recently been a controversy. We propose a simple numerical scheme by which one can easily determine whether the observed synchronization is a numerical artifact of computer analysis or not. By using this scheme, for certain coupling strength regime, we find that the average time taken for synchronization linearly depends on the precision of calculations. According to Longa et al.'s criterion for synchronization, this implies that the observed synchronization is genuine.

Potential of adenoviral p53 gene therapy and irradiation for the treatment of malignant gliomas

We investigated the combined effects of p53 gene transfer and irradiation and its still unclear interaction mechanism in human gliomas. Four human glioma cell lines expressing mutant type p53 (U373 and A172) and wild-type p53 (D54MG and EFC-2) were transfected by adenoviral vectors bearing p53 gene at 50 multiplicity of infection. Two days after transfection, cells were irradiated (3, 6, and 9 Gy). The cytotoxicity was evaluated by clonogenic assay. The quantitative analysis of apoptosis and cell cycle analysis were performed using flow cytometry. Irradiation combined with adenoviral p53 transfection significantly increased cytotoxicity, which was additive in cell lines with wild-type p53 and more than additive in cell lines with mutant p53. The combination of two modalities increased the apoptotic population by 14% in A172 cells and 20% in D54 MG cells, which were the sum of apoptosis from each modality. Adenoviral p53 transfection increased the G1 phase fraction and concomitant decrease of radioresistant S phase fraction in A172 and D54MG cells. Our study demonstrated that p53 gene transfer combined with irradiation increased absolute cytotoxicity in human glioma cells used in this experiment. The interaction mechanism for increased cytotoxicity involved, in part, increased apoptosis and change of cell cycle profile.

Expression of telomerase activity in cholesteatoma otitis media

Telomerase maintains the length of telomeres in immortal cells and is also often associated with cell proliferation. Cholesteatoma epithelium is characterized by a dysregulation with hyperproliferative growth. The study evaluated the telomerase activity in cholesteatoma and normal retro-auricular skin to discover the relationship between telomerase expression and clinical findings. Twenty-two samples of cholesteatoma and 15 samples of retro-auricular skin were obtained from patients undergoing middle-ear surgery. The telomerase activity was detected by the telomerase repeat amplification protocol (TRAP) assay method. Seventeen of the 22 (77.3 per cent) cholesteatoma cases expressed telomerase activity, whereas none of the 15 retro-auricular normal skin (0 per cent) detected telomerase activity. There was no significant difference between telomerase expressions and clinical findings, including hearing level, duration of disease, and the degree of extension (p>0.05). The high expression of telomerase in cholesteatoma suggests that the activation of telomerase may be related to the proliferative nature of cholesteatoma.

Electroconvulsive shock reduces inositol trisphosphate receptor1 mRNA in rat brain

We studied the expression pattern of the inositol 1,4,5-trisphosphate receptor1 (InsP3R1) mRNA after a single electroconvulsive shock (ECS) in the rat brain by in situ hybridization. The expression was significantly decreased in the dentate gyrus and the CA1 area of the hippocampal formation 3 to 24 h after ECS. While the downregulation of InsP3R1 by accelerated protein degradation has been reported, our results indicate that the downregulation of InsP3R1 occurs at the mRNA level. This finding, along with our previous report on the InsP3 3-kinase(A), suggests that ECS regulates the phosphoinositide mediated signaling, which might be related to the therapeutic mechanism of ECS.

Phase synchronization in coupled Nd:YAG lasers

We investigate experimentally the transition to phase synchronization in coupled Nd:YAG lasers. As the coupling strength increases, the phase difference of two chaotic laser outputs develops from nonsynchronous to a phase-synchronous state via +/-2pi phase jumps. We analyze this transition.

Mechanism of synchronization in a random dynamical system

The mechanism of synchronization in the random Zaslavsky map is investigated. From the error dynamics of two particles, the structure of phase space was analyzed, and a transcritical bifurcation between a saddle and a stable fixed point was found. We have verified the structure of on-off intermittency in terms of a biased random walk. Furthermore, for the generalized case of the ensemble of particles, a modified definition of the size of a snapshot attractor was exploited to establish the link with a random walk. As a result, the structure of on-off intermittency in the ensemble of particles was explicitly revealed near the transition.

Induction of apoptosis in p53-deficient human hepatoma cell line by wild-type p53 gene transduction: inhibition by antioxidant

We investigated the role of wild-type (wt)-p53 as an inducer of apoptotic cell death in human hepatoma cell lines. Following the retrovirus-mediated transduction of the wt-p53 gene, Hep3B cells lacking the endogenous p53 expression began to die through apoptosis in 4 h. They showed a maximal apoptotic death at 12 h, whereas HepG2 cells expressing endogenous p53 did not. However, the transduction of the wt-p53 gene elicited growth suppression of both Hep3B and HepG2 cells. P21(WAF1/CIP1), a p53-inducible cell cycle inhibitor, was induced, not only in Hep3B cells undergoing apoptosis, but also in HepG2 cells. The kinetics of the p21(WAF1/CIP1) induction, DNA fragmentation, and growth suppression of the Hep3B cells showed that DNA fragmentation and growth suppression progressed rapidly following p21(WAF1/CIP1) accumulation. N-acetyl-cysteine or glutathione, potent antioxidants, strongly inhibited the DNA fragmentation, but did not reduce the elevated level of p21(WAF1/CIP1). These findings suggested that p21(WAF1/CIP1) was not a critical mediator for the execution of p53-mediated apoptosis, although it contributed to the growth inhibition of cells undergoing apoptosis. Furthermore, p53-mediated apoptosis could be repressed by antioxidants.

Bisubstrate ketone analogues as serotonin N-acetyltransferase inhibitors

Serotonin N-acetyltransferase, also called the melatonin rhythm enzyme, is thought to play an important regulatory role in circadian rhythm in animals and people. A series of analogues were synthesized in which indole and coenzyme A were linked via ketone tethers as designed inhibitors of this enzyme. These compounds were tested against purified serotonin N-acetyltransferase. The parent ketone compound was found to be as potent as an amide linked compound studied previously, suggesting that there are no key hydrogen bonds to the nitrogen atom of the corresponding substrate necessary for tight inhibition. Reduction of the parent ketone afforded the diastereomeric carbinol mixture which showed reduced inhibitory potency, arguing against tetrahedral analogue mimicry as an important inhibitory theme. Several conformationally constrained ketone analogues were synthesized and investigated, and the results indicated that directing the orientation of the two substrates within the bisubstrate system could be used to maximize enzyme inhibition.

Reciprocal expressions of cyclin E and cyclin D1 in hepatocellular carcinoma

Deregulation of the cell cycle by overexpression of G1 cyclins, cyclin E and cyclin D1 genes, has been demonstrated to be a prerequisite for the development of human cancer. Recently, cyclin E is proposed to be sufficient for the progression of the G1 cell cycle without cyclin D1. Here we show that the proposed model system was specifically present in human hepatocellular carcinoma (HCC) unlike other human cancers. Of 31 HCC tissues analyzed, 21 (67.7%) exhibited an overexpression of cyclin E protein. In contrast to cyclin E gene expression, cyclin D1 expression was strongly downregulated in 19 (61.2%) HCCs. Interestingly, 65% of HCC tissues with overexpression of the cyclin E gene exhibited downregulation of cyclin D1, suggesting reciprocal deregulation of these cyclins in the G1 progression of the cell cycle. Southern blot analysis proved the amplification of cyclin E gene in HCC with a high level of overexpression. The present findings suggest that the reciprocal deregulation of cyclin E lacking cyclin D1 expression might play a role in G1 progression and the development of HCC.

Generation of fusion genes carrying drug resistance, green fluorescent protein, and herpes simplex virus thymidine kinase genes in a single cistron

We generated new fusion genes carrying positive- and negative-selection markers, and a reporter gene in a single reading frame. The new genes were constructed by sequentially linking the coding sequences of drug-resistance genes (hygro, or puro), a green fluorescence protein (GFP) gene (gfp), and the thymidine kinase gene (tk). The new synthetic genes (hygro/gfp/tk and puro/ gfp/tk) were inserted into retroviral vectors to test their usefulness as selective markers and reporters. The genes were functional in a positive selection in the presence of hygromycin (hygro/gfp/tk) or puromycin (puro/gfp/ tk). In addition, cells expressing the new fusion genes were clearly identifiable by their green fluorescence emitted from GFP. At the same time, these cells were sensitive to a gancyclovir treatment, allowing efficient removal of the transduced cells. The presently described synthetic genes will be valuable tools in both gene therapy and basic gene transfer studies, where positive selection of the transduced cells, monitoring gene expression, and negative selection of the transduced cells are simultaneously required.

In vivo antitumor effect of herpes simplex virus thymidine kinase gene therapy in rat hepatocellular carcinoma: feasibility of adenovirus-mediated intra-arterial gene delivery

Transfer of the herpes simplex virus-thymidine kinase gene, followed by the administration of ganciclovir (HSV-tk/GCV), has been a major approach for cancer gene therapy. We investigated the antitumor effect of the HSV-tk/GCV strategy with the rat orthotopic hepatocellular carcinoma (HCC) model and the tumor-selective gene delivery by an adenovirus-mediated gene transfer through the hepatic artery. The complete antitumor effect was demonstrated, after the treatment with GCV in rat HCC established by the implantation of HSV-tk transferred rat HCC cells. The in vivo bystander effect was also observed. The marked infiltration of CD4+ and CD8+ T lymphocytes, macrophages and NK cells were found in the tumor area. After the injection of adenovirus carrying the LacZ gene into the hepatic artery, the selective expression of transgene in the tumor cell was achieved. These findings indicate that the HSV-tk/GCV strategy, using an adenoviral vector, could be a promising avenue for the treatment of hepatocellular carcinoma.

Two-dimensional type-I intermittency

The general structure of two-dimensional intermittency is discussed. The structure of channel and the trajectory in the return map are compared with those of one-dimensional intermittency and the scaling relations are obtained according to the trajectory. We illustrate the temporal behavior and scaling relations in a coupled map. The numerical results agree well with the theoretical predication of <l> approximately equal 1/sqrt[epsilon].

Growth-inhibitory effect of adenovirus-mediated p53 gene transfer on medulloblastoma cell line, Daoy, harboring mutant p53

To improve the survival rate, gene therapy, such as the replacement of inactivated tumor suppressor genes, has become a new investigational adjuvant treatment modality for human malignancies. We investigated the effect of adenovirus(Ad)-mediated transfer of wildtype p53 tumor suppressor gene on the medulloblastoma cell line, Daoy, which harbors mutant-type p53 gene. At 50 multiplicity of infection (moi), immunohistochemical staining with p53 monoclonal antibody showed positive staining in all cells 2 days after Ad-CMV-p53 infection. The high expression of wild-type p53 protein was detected in Ad-CMV-p53-infected cells, and expression of wild-type p53 protein peaked on day 2 after the infection. The growth of Ad-CMV-p53-infected cells was greatly suppressed in vitro, and the Ad-CMV-p53 treatment significantly reduced the tumor mass in vivo. The mean weight of Ad-CMV- infected tumors was only 16% of those which were mock infected, and 25% of those which were Ad-CMV-beta-gal infected. On microscopic examination, Ad-CMV-p53-infected tumors showed numerous apoptotic bodies. This Ad-CMV-p53 gene transfer showed high transduction efficacy and expression, resulting in significant growth inhibition of Daoy harboring mutant type p53.

Adenovirus expressing p27(Kip1) induces growth arrest of lung cancer cell lines and suppresses the growth of established lung cancer xenografts

p27(Kip1) (p27) is a member of the universal cyclin-dependent kinase inhibitor (CDKI) family and a putative tumor suppressor gene. In several tumors including lung cancer, decreased expression of p27 is associated with poor prognosis. These observations suggest a potential role for p27 as a new gene therapy target. In this study, we constructed adenovirus expressing human p27 (ad-p27) and investigated its antitumor effects on human lung cancer cell lines. Upon transduction of several human lung cancer cells with ad-p27, a high level of p27 expression, with a decrease in cdk2 and an increase in cyclin E were observed. These changes resulted in G1/S arrest. Transduction of human lung cancer cell lines with ad-p27 showed in vitro growth inhibition and a marked suppression of colony formation upon soft agar clonogenic assay. Direct intratumoral injection of ad-p27 induced the growth suppression of established lung tumors in nude mice. From these observations, gene therapy using ad-p27 seems to offer a potential basis for the development of new cancer gene therapy modality and a useful tool to investigate the mechanisms of cell cycle control.

Growth inhibitory effect on glioma cells of adenovirus-mediated p16/INK4a gene transfer in vitro and in vivo

The tumour suppressor gene p16/INK4a encodes a specific inhibitor of the cyclin D-dependent kinases CDK4 and CDK6. p16/INK4a prevents the association of CDK4 with cyclin D1, and subsequently inhibits phosphorylation of retinoblastoma tumour suppressor protein (pRb), thus preventing exit from the G1 phase. In human cancers, the estimated frequency of genetic alteration involving the p16/INK4a locus is believed to be second only to alteration of p53. A high frequency (greater than 50%) of homozygous p16/INK4a gene deletion has been demonstrated in glioblastoma tissues and p16/INK4a is altered in 80% of glioma cell lines. Therefore, restoration of p16/INK4a would suppress cell proliferation and induce cell growth arrest. We showed here that restoration of p16/INK4a expression in p16 negative U87MG, U251MG and partially deleted U373MG by Ad-CMV-p16/INK4a induced growth suppression in vitro and in vivo. Expression of p16 transferred by Ad-CMV-p16/INK4a in glioma cells was highly efficient and maintained for more than seven days. In addition, we found that the endogenous status of p16 and Rb might affect the expression of exogenous p16/INK4a gene and inhibitory effect of cell proliferation. Even though, there were several factors affecting the efficiency of Ad-CMV-p16/INK4 gene transfer, our results suggest that Ad-CMV-p16 gene therapy strategy is potentially useful and warrants further clinical investigation for the treatment of gliomas.

Phase synchronization with type-II intermittency in chaotic oscillators

We study the phase synchronization (PS) with type-II intermittency showing +/-2pi irregular phase jumping behavior before the PS transition occurs in a system of two coupled hyperchaotic Rossler oscillators. The behavior is understood as a stochastic hopping of an overdamped particle in a potential which has 2pi-periodic minima. We characterize it as type-II intermittency with external noise through the return map analysis. In epsilon(t)<epsilon<epsilon(c) (where epsilon(t) is the bifurcation point of type-II intermittency and epsilon(c) is the PS transition point in coupling strength parameter space), the average length of the time interval between two successive jumps follows <l> approximately exp(|epsilon(t)-epsilon|(2)), which agrees well with the scaling law obtained from the Fokker-Planck equation.

Characteristic relations of type-I intermittency in the presence of noise

Near the point of tangent bifurcation, the scaling properties of the laminar length of type-I intermittency are investigated in the presence of noise. Based on analytic and numerical studies, we show that the scaling relation of the laminar length is dramatically deformed from 1/sqrt[epsilon] for epsilon>0 to exp(1/D)|epsilon|(3/2) for epsilon<0 as epsilon passes the bifurcation point (epsilon=0). The results explain why two coupled Rossler oscillators exhibit deformation of the scaling relation of the synchronous length in the nearly synchronous regime.

Growth inhibitory effect on glioma cells of adenovirus-mediated p16/INK4a gene transfer in vitro and in vivo

The tumour suppressor gene p16/INK4a encodes a specific inhibitor of the cyclin D-dependent kinases CDK4 and CDK6. p16/INK4a prevents the association of CDK4 with cyclin D1, and subsequently inhibits phosphorylation of retinoblastoma tumour suppressor protein (pRb), thus preventing exit from the G1 phase. In human cancers, the estimated frequency of genetic alteration involving the p16/INK4a locus is believed to be second only to alteration of p53. A high frequency (greater than 50%) of homozygous p16/INK4a gene deletion has been demonstrated in glioblastoma tissues and p16/INK4a is altered in 80% of glioma cell lines. Therefore, restoration of p16/INK4a would suppress cell proliferation and induce cell growth arrest. We showed here that restoration of p16/INK4a expression in p16 negative U87MG, U251MG and partially deleted U373MG by Ad-CMV-p16/INK4a induced growth suppression in vitro and in vivo. Expression of p16 transferred by Ad-CMV-p16/INK4a in glioma cells was highly efficient and maintained for more than seven days. In addition, we found that the endogenous status of p16 and Rb might affect the expression of exogenous p16/INK4a gene and inhibitory effect of cell proliferation. Even though, there were several factors affecting the efficiency of Ad-CMV-p16/INK4 gene transfer, our results suggest that Ad-CMV-p16 gene therapy strategy is potentially useful and warrants further clinical investigation for the treatment of gliomas.

Chaotic transition of random dynamical systems and chaos synchronization by common noises

We studied the mechanism behind the connection between the transition to chaos of random dynamical systems and the synchronization of chaotic maps driven by external common noises. Near the chaotic transition, the spatial size of random dynamical systems shows an extreme intermittent behavior. By calculating the scaling exponents, we have found that the origin of this intermittent behavior is on-off intermittency. This led us to conclude that chaotic transitions through on-off intermittency can be regarded as a route for random dynamical systems. To clarify this argument, a two-dimensional random dynamical system and two coupled logistic maps driven by external common noises were analyzed.

Soft-x-ray emission from small-sized Ne clusters heated by intense, femtosecond laser pulses

Soft-x-ray emission from a cryogenically cooled Ne jet irradiated by intense, 25-fs laser pulses was measured. The Ne spectrum started to drastically change in emitting ions from Ne5+ to Ne7+ below the preexpansion temperature of -120 degrees C. The significant change in the spectrum is attributed to the collisional heating of small-sized Ne clusters formed in the cooled jet. The increase of the laser pulse length from 25 fs to 100 fs resulted in further increase of x-ray emission from Ne7+ states.

The inhibition of ERK/MAPK not the activation of JNK/SAPK is primarily required to induce apoptosis in chronic myelogenous leukemic K562 cells

In this study, the downstream signaling of Bcr-Abl tyrosine kinase responsible for apoptosis resistance was investigated. DNA fragmentation, a hallmark of apoptosis, was observed after 2 days of herbimycin A treatment with a peak on 3 day. During the apoptosis induced by the treatment of herbimycin A, stress-activated protein kinase (SAPK) and p38 kinase were activated time- and dose-dependently, while extracellular signal-regulated kinase (ERK) was inhibited. However, apoptosis was induced by the treatment of PD98059, a specific inhibitor of MEK (MAPK or ERK kinase), not by the treatment of sorbitol, a strong activator of SAPK and p38 kinase. Although K562 cells were very resistant to sorbitol-induced apoptosis, DNA fragmentation was induced rapidly in Jurkat, HL-60 and U937 cells after exposure to sorbitol, despite that these apoptosis-sensitive cells have similar or lower activities of JNK/SAPK and p38 kinase compared with K562 cells after treatment of sorbitol. K562 cells had a much higher basal activity of ERK/MAPK than other apoptosis-sensitive cell lines, which were very susceptible to apoptosis induced by low dose of PD98059 compared with K562 cells. In HL-60 cells, sorbitol-induced apoptosis was prevented by the treatment of phorbol myristate 13-acetate (PMA), which activates the ERK/MAPK pathway, and this was blocked by PD98059. From these results, it could be suggested that the inhibition of ERK/MAPK not the activation of JNK/SAPK is primarily required to induce apoptosis in K562 cells.

Incidence and characterization of Listeria monocytogenes from domestic and imported foods in Korea

A total of 1,537 domestic and imported food products were examined for the incidence of Listeria monocytogenes between 1993 and 1997 in Korea. L. monocytogenes was detected using the U.S. Department of Agriculture isolation method. Isolated L. monocytogenes was confirmed by polymerase chain reaction with hly1 and hly2 primers designed from the listeriolysin O. Overall, 122 samples (7.9%) contained L. monocytogenes. The rate of isolation was 4.3% for beef, 19.1% for pork, 30.2% for chicken, 1.2% for shellfish, 4.4% for raw milk, 4.4% for frozen smoked mussels, and 6.1% for ice cream. No L. monocytogenes was found in pasteurized milk, pasteurized processed cheese, saltwater fish, dried seafoods, or ham. The overall incidence was lower than that reported in previous studies from other countries. Most isolates were serotype 1/2b except for chicken, in which serotype 1/2a was predominant. The serotyping results might imply the presence of food or geography-specific L. monocytogenes strains.

A formal asymmetric synthesis of Mugineic acid: an efficient synthetic route through chiral oxazolidinone

A formal asymmetric synthesis of Mugineic acid was accomplished from cis-2-butene-1,4-diol through catalytic Sharpless epoxidation oxidations and coupling reaction.

A novel function of IL-12p40 as a chemotactic molecule for macrophages

IL-12p70 plays a pivotal role in regulating the Th1/Th2 balance in the initial stage of immune responses. In contrast, IL-12p40, which is produced excess over IL-12p70, has been known to down-regulate IL-12p70-mediated responses by acting as an antagonist. To investigate in vivo function of IL-12p40, RH7777 rat hepatoma cells were engineered to inducibly express mouse IL-12p40 under the tight control of doxycycline (dox). In the absence of dox, s.c. injection of these cells into syngeneic rat was shown to generate tumors. However, the induction of IL-12p40 by dox was sufficient for inhibiting tumor formation, as well as for tumor regression. Immunohistochemical analysis showed that macrophages, but not CD4+ T, CD8+ T, and NK cells, were predominantly recruited into tumor sites as early as 3 days after IL-12p40 induction. These results were further supported by the observation that IL-12p40, but not C-terminal deletion mutants by more than 5 amino acids, was able to chemoattract peritoneal macrophages in vitro, suggesting that IL-12p40, when produced in a large excess over IL-12p70 in vivo, can initially amplify the immune responses against tumors by directly recruiting macrophages. Our findings indicate that IL-12p40 may function as an effector molecule as well as an antagonist of IL-12p70.

Induction of cytotoxic T lymphocytes with peptides in vitro: identification of candidate T-cell epitopes in hepatitis B virus X antigen

Cytotoxic T lymphocytes (CTL) have been suggested to contribute to viral clearance during hepatitis B virus (HBV) infection. To induce effective CTL against viral infection by peptide vaccination, it is essential to identify the epitope peptides recognized by CTL. Here, 15 peptide sequences that contain HLA-A2.1-restricted CTL binding consensus motif were identified on hepatitis B virus X (HBx) protein and synthesized for further characterization. In the binding assay, 8 of 15 synthetic peptides enhanced the expression of HLA-A2.1 molecules on the surface of T2 cells, a human transport-associated antigen processing-deficient cell line. This result implies that these eight peptides are able to bind to the HLA-A2.1 molecules. These peptides were further tested for their ability to activate CTL from peripheral blood mononuclear cells (PBMCs) isolated from HBV chronic carriers. Five of eight tested peptides activated PBMC-derived T cells, resulting in the lysis of the target T2 cells pulsed with the same peptide. Furthermore, the CTL responses to HBx antigen in HBV chronic carriers were shown to be polyclonal, multispecific, and mediated mainly by CD8+ T cells. In contrast, these responses were not detected in uninfected healthy blood donors. Although the five CTL epitope peptides identified in this study have not been proven to be the naturally processed epitopes in HBV-infected hepatocytes, they could be candidates for peptide-based immunotherapy against HBV infection.

Adjuvant (cisplatin, etoposide, and 5-fluorouracil) chemotherapy after curative resection of gastric adenocarcinomas involving the esophagogastric junction

Gastric adenocarcinomas involving the esophagogastric junction represent a particular therapeutic problem because they lie in the border area between two body cavities: the thorax and the abdomen. The prognosis of gastric adenocarcinomas involving esophagogastric junction is poor because there is widespread lymphatic metastasis, making curative resection difficult. Even in patients with localized disease who are potentially curable, the 5-year survival rate is approximately 20% with curative resection only, somewhat lower than for those with cancer elsewhere in the stomach. The authors conducted a pilot study to evaluate the safety and possible efficacy of adjuvant chemotherapy with cisplatin, etoposide, and 5-fluorouracil (PEF) after curative resection of gastric adenocarcinoma involving esophagogastric junction. Three cycles of adjuvant PEF chemotherapy with cisplatin (20 mg/m2/day intravenously on days 1-5), etoposide (100 mg/m2/day intravenously on days 1, 3, and 5), and 5-fluorouracil (800 mg/m2/day continuous intravenous infusion on days 1-5) were given every 3 weeks after curative resection of gastric adenocarcinoma involving the esophagogastric junction. Between November 1989 and June 1995, a total of 50 patients with postoperative stage II, IIIA, or IIIB disease entered this trial. In 14 of 50 patients (28%), the disease recurred during the follow-up of 4-83 months (median 26 months). Disease-free survival was 4-83+ months (median 48 months), and the actuarial 5-year disease-free survival rate was 48% (95% CI: 41% to 55%). Overall survival was 4-83+ months (median 62 months), and the actuarial 5-year survival rate was 54% (95% CI: 40% to 68%). The prognostic factor analysis showed that the postoperative N stage and the interval between surgery and chemotherapy affected disease-free survival and overall survival. The toxicities of PEF adjuvant chemotherapy were leukopenia, nausea/vomiting, and alopecia, but they were mostly mild and reversible except in one patient who died because of treatment-related sepsis. Adjuvant chemotherapy with three cycles of PEF regimen was well tolerated and seems to be a promising treatment for gastric adenocarcinoma involving the esophagopstric junction, in comparison with previous treatments. To define the efficacy of adjuvant PEF chemotherapy for gastric adenocarcinoma involving esophagogastric junction, prospective randomized trials are warranted.

Intravenous calcitriol regresses myocardial hypertrophy in hemodialysis patients with secondary hyperparathyroidism

To evaluate the response of circulating intact parathyroid hormone (iPTH) on myocardial hypertrophy in hemodialysis (HD) patients with secondary hyperparathyroidism (SHPT), echocardiographic and neurohormonal assessments were performed over a 15-week period in 15 HD patients with SHPT before and after calcitriol treatment and 10 HD control patients with SHPT not receiving calcitriol therapy. We prospectively studied a group of 15 patients with significantly elevated iPTH levels (iPTH >450 pg/mL) receiving calcitriol (2 microg after dialysis twice weekly). Clinical assessment, medication status, and biochemical and hematological measurements were performed once a month. Throughout the study, calcium carbonate levels were modified to maintain serum phosphate levels at less than 6 mg/dL, but body weight, antihypertensive medication, and ultrafiltration dose remained constant. In patients treated with calcitriol, an adequate reduction of iPTH levels was found (1,112 +/- 694 v 741 +/- 644 pg/mL; P < 0.05) without changes in values of serum ionized calcium (iCa++), phosphate, or hematocrit. Blood pressure (BP), cardiac output (CO), and total peripheral resistance (TPR) did not significantly change. After 15 weeks of treatment with calcitriol, M-mode echocardiograms showed pronounced reductions in interventricular wall thickness (13.9 +/- 3.6 v 12.8 +/- 3.10 mm; P = 0.01), left ventricular posterior wall thickness (12.5 +/- 2.4 v 11.3 +/- 1.8 mm; P < 0.05), and left ventricle mass index (LVMi; 178 +/- 73 v 155 +/- 61 g/m2; P < 0.01). However, in control patients, these changes were not found after the treatment period. In addition, sequential measurements of neurohormonal mediator levels in patients receiving calcitriol showed that plasma renin (18.5 +/- 12.7 v 12.3 +/- 11.0 pg/mL; P = 0.007), angiotensin II (AT II; 79.7 +/- 48.6 v 47.2 +/- 45.7 pg/mL; P = 0.001), and atrial natriuretic peptide (ANP; 16.6 +/- 9.7 v 12.2 +/- 4.4 pg/mL; P = 0.03) levels significantly decreased, whereas antidiuretic hormone (ADH), epinephrine, and norepinephrine levels did not change significantly. The percent change in LVMi associated with calcitriol therapy had a strong correlation with the percent change in iPTH (r = 0.52; P < 0.05) and AT II (r = 0.47; P < 0.05) levels. We conclude that the partial correction of SHPT with intravenous calcitriol causes a regression in myocardial hypertrophy without biochemical or hemodynamic changes, such as heart rate, BP, and TPR. The changes in plasma levels of iPTH and, secondarily, plasma levels of neurohormones (especially AT II) after calcitriol therapy may have a key role in attenuating ventricular hypertrophy in SHPT.