Clinical value of deep learning image reconstruction on the diagnosis of pulmonary nodule for ultra-low-dose chest CT imaging.

PURPOSE: To compare the image quality and pulmonary nodule detectability between deep learning image reconstruction (DLIR) and adaptive statistical iterative reconstruction-Veo (ASIR-V) in ultra-low-dose CT (ULD-CT). METHODS: 142 participants required lung examination who underwent simultaneously ULD-CT (UL-A, 0.57 ± 0.04 mSv or UL-B, 0.33 ± 0.03 mSv), and standard CT (SDCT, 4.32 ± 0.33 mSv) plain scans were included in this prospective study. SDCT was the reference standard using ASIR-V at 50% strength (50%ASIR-V). ULD-CT was reconstructed with 50%ASIR-V, DLIR at medium and high strength (DLIR-M, DLIR-H). The noise, signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), and subjective scores were measured. The presence and accuracy of nodules were analyzed using a combination of a deep learning-based nodule evaluation system and a radiologist. RESULTS: A total of 710 nodules were detected by SDCT, including 358 nodules in UL-A and 352 nodules in UL-B. DLIR-H exhibited superior noise, SNR, and CNR performance, and achieved comparable or even higher subjective scores compared to 50%ASIR-V in ULD-CT. Nodules sensitivity detection of 50%ASIR-V, DLIR-M, and DLIR-H in ULD-CT were identical (96.90%). In multivariate analysis, body mass index (BMI), nodule diameter, and type were independent predictors for the sensitivity of nodule detection (p<.001). DLIR-H provided a lower absolute percent error (APE) in volume (3.10% ± 95.11% vs 8.29% ± 99.14%) compared to 50%ASIR-V of ULD-CT (P<.001). CONCLUSIONS: ULD-CT scanning has a high sensitivity for detecting pulmonary nodules. Compared with ASIR-V, DLIR can significantly reduce image noise, and improve image quality, and accuracy of the nodule measurement in ULD-CT.

Reducing temperature sensitivity of gas measurement using chirped-modulated photoacoustic spectroscopy.

Resonance frequency drift caused by a change in temperature greatly limits the application of high-Q resonators with high temperature sensitivity in photoacoustic (PA) gas detection systems. In this work, a chirp-wavelength combined modulation method was designed by incorporating a real-time frequency scanning in wavelength-modulated PA spectroscopy to reduce the influence of temperature changes on measurement. Theoretical analysis shows that the chirp rate depends on the precision requirements and the cutoff frequency of the cascaded low-pass filter. Trace acetylene measurement experiment at varying temperature verified that the proposed method can significantly reduce the temperature sensitivity within a preset temperature range. Thus, this method can effectively reduce the temperature sensitivity of a high-Q resonator for improving the measurement accuracy and detection limit in trace gas detection.

Prognostic value of the platelet-to-lymphocyte ratio for outcomes of stroke: a systematic review and meta-analysis.

OBJECTIVE: The current study aimed to conduct a systematic literature search and pool data from individual studies to assess the relationship between platelet-lymphocyte ratio (PLR) and functional outcomes and mortality in stroke patients. MATERIALS AND METHODS: The databases of PubMed, Embase and Google Scholar were searched for relevant studies up to 21st August 2021. Odds ratios (OR) with 95% confidence intervals (CI) were calculated for the association between PLR and poor functional outcomes and mortality. RESULTS: Sixteen studies were included in the systematic review and nine in the meta-analysis. On analysis of eight studies, we noted no statistically significant relationship between PLR and poor functional outcomes in patients with stroke (OR: 1.00 95% CI: 1.00, 1.00 I2=80% p=0.30). Data on mortality was reported by just two studies. Pooled analysis indicated no statistical relationship between PLR and mortality in patients with stroke (OR: 1.49 95% CI: 0.56, 3.98 I2=76% p=0.43). Descriptive analysis of the remaining studies demonstrated conflicting results for the relationship between PLR and early neurological deterioration (END) and functional outcomes. CONCLUSIONS: Our results indicate that PLR may not be a useful prognostic marker to predict functional outcomes after AIS. Evidence on the predictive power of PLR for mortality and END after stroke is scarce and contrasting. There is a need for further studies assessing the role of PLR in predicting outcomes of stroke patients while taking into account important confounders like baseline stroke severity and treatment modality.

[Current status of hyperkalemia in dialysis patients in China].

Objective: To investigate the prevalence and associated factors of hyperkalemia in dialysis patients. Methods: Patients underwent hemodialysis (HD) and peritoneal dialysis (PD) from multi-center databases were recruited from January 2017 to December 2019, and those aged ≥18 years and with dialysis duration ≥3 months were included to analyze the prevalence and related factors of hyperkalemia. Results: A total of 12 364 patients were enrolled in the study, and 6 836 cases were men. The average age of the patients was (51±15) years. Among these patients, 4 230 cases underwent HD while 8 134 received PD. Hyperkalemia was detected in 20.7% (2 554/12 364) of the patients while hypokalemia was found in 17.0%(2 102/12 364) of the patients. Multivariate logistic regression showed that HD (OR=2.25, 95%CI: 1.54-3.30), diabetes mellitus (DM) (OR=1.65, 95%CI: 1.17-2.32), high body mass index (BMI) (OR=1.06, 95%CI: 1.03-1.09), high levels of serum albumin (OR=1.04, 95%CI: 1.01-1.07) and phosphorus (OR=3.12, 95%CI: 2.44-4.00), low levels of serum bicarbonate (OR=0.89, 95%CI: 0.87-0.92), triglycerides (OR=0.76, 95%CI: 0.68-0.85) and creatinine (OR=0.95, 95%CI: 0.90-0.99), usage of angiotensin converting enzyme inhibitor/Angiotensin Ⅱ receptor antagonist (ACEI/ARB, OR=1.38, 95%CI: 1.11-1.72) and beta-blocker (OR=1.32, 95%CI: 1.07-1.64) were associated with hyperkalemia. Conclusions: Hyperkalemia occurred in 20.7% of the dialysis patients. HD, DM, high BMI, high levels of serum albumin and phosphorus, low levels of serum bicarbonate, triglycerides and creatinine, use of ACEI/ARB were associated with hyperkalemia.

The association between vitamin D receptor FokI gene polymorphism and osteoporosis in postmenopausal women: a meta-analysis.

OBJECTIVE: This study aimed to quantitatively summarize the evidence for vitamin D receptor (VDR) FokI gene polymorphism and osteoporosis risk in Caucasian and Asian postmenopausal women. MATERIALS AND METHODS: The PubMed, EMBASE, Weipu, CNKI, and Wanfang databases were searched for eligible studies. Case-control studies containing available genotype frequencies for F/f were chosen, and the odds ratio (OR) with 95% confidence interval (CI) was used to assess the strength of this association. RESULTS: In total, 3349 osteoporosis cases and 3202 controls were identified in our meta-analysis. In the stratified analysis, a significant association was observed between VDR FokI gene polymorphism and postmenopausal osteoporosis susceptibility in Asian subjects (additive model: OR = 1.529, 95% CI 1.053-2.219, p = 0.026; dominant model: OR 2.711, 95% CI 1.693-4.342 p < 0.001; co-dominant model: ff vs. FF, OR 2.796, 95% CI 1.439-5.433 p = 0.002), and we failed to find any significant relationship in Caucasian populations. CONCLUSION: The present meta-analysis suggests that the VDR FokI genotype is associated with increased risk of osteoporosis in Asian women but not in Caucasian women. To draw comprehensive and true conclusions, further prospective studies with larger numbers of participants worldwide are needed to examine associations between VDR FokI polymorphism and osteoporosis.

Intermittent occupancy combined with ventilation: An efficient strategy for the reduction of airborne transmission indoors.

It is important that efficient measures to reduce the airborne transmission of respiratory infectious diseases (including COVID-19) should be formulated as soon as possible to ensure a safe easing of lockdown. Ventilation has been widely recognized as an efficient engineering control measure for airborne transmission. Room ventilation with an increased supply of clean outdoor air could dilute the expiratory airborne aerosols to a lower concentration level. However, sufficient increase is beyond the capacity of most of the existing mechanical ventilation systems that were designed to be energy efficient under non-pandemic conditions. We propose an improved control strategy based on source control, which would be achieved by implementing intermittent breaks in room occupancy, specifically that all occupants should leave the room periodically and the room occupancy time should be reduced as much as possible. Under the assumption of good mixing of clean outdoor supply air with room air, the evolution of the concentration in the room of aerosols exhaled by infected person(s) is predicted. The risk of airborne cross-infection is then evaluated by calculating the time-averaged intake fraction. The effectiveness of the strategy is demonstrated for a case study of a typical classroom. This strategy, together with other control measures such as continuous supply of maximum clean air, distancing, face-to-back layout of workstations and reducing activities that increase aerosol generation (e.g., loudly talking and singing), is applicable in classrooms, offices, meeting rooms, conference rooms, etc.

Airborne spread of expiratory droplet nuclei between the occupants of indoor environments: A review.

This article reviews past studies of airborne transmission between occupants in indoor environments, focusing on the spread of expiratory droplet nuclei from mouth/nose to mouth/nose for non-specific diseases. Special attention is paid to summarizing what is known about the influential factors, the inappropriate simplifications of the thermofluid boundary conditions of thermal manikins, the challenges facing the available experimental techniques, and the limitations of available evaluation methods. Secondary issues are highlighted, and some new ways to improve our understanding of airborne transmission indoors are provided. The characteristics of airborne spread of expiratory droplet nuclei between occupants, which are influenced correlatively by both environmental and personal factors, were widely revealed under steady-state conditions. Owing to the different boundary conditions used, some inconsistent findings on specific influential factors have been published. The available instrumentation was too slow to provide accurate concentration profiles for time-dependent evaluations of events with obvious time characteristics, while computational fluid dynamics (CFD) studies were mainly performed in the framework of inherently steady Reynolds-averaged Navier-Stokes modeling. Future research needs in 3 areas are identified: the importance of the direction of indoor airflow patterns, the dynamics of airborne transmission, and the application of CFD simulations.

[microRNA targeted to chronic myeloid leukemia Bcr-Abl oncogene screen using deacetylase inhibitor].

Objective: microRNA targeted to chronic myeloid leukemia Bcr-Abl oncogene were screened using the deacetylase inhibitor suberoylanilide hydroxamic acid (SAHA). Methods: The proliferation inhibition effect of SAHA on chronic myeloid leukemia K562 cell was detected by MTS method, and the optimal concentration of SAHA reaction was determined. Western blot was used to detect the level of PARP protein, and making sure whether SAHA induced apoptosis of K562 cell. Effect of SAHA on Bcr-Abl Gene Transcription in K562 Cells was determined by Fluorescence Quantitative PCR. The online software Target Scan and real-time fluorescence quantitative PCR was used to screen Bcr-Abl-targeted microRNA. The viability of K562 cells and Bcr-Abl transcription levels were detected by MTS method and quantitative PCR respectively after selected microRNA were transfected into K562 cell. Results: SAHA significantly inhibited the proliferation of K562 cells and induced apoptosis, meanwhile SAHA significantly down-regulated the transcriptional level of Bcr-Abl gene. After treatment of K562 cells with SAHA, two microRNA, miR-192 and miR-6816, which could target Bcr-Abl, were screened by Target Scan and quantitative PCR. Additionally, SAHA induced the miRNAs to up-regulate 14.5 and 5.2 times, respectively. Transfection of miR-192 and miR-6816 to K562 cells significantly inhibited K562 cell viability and down-regulated the transcriptional level of Bcr-Abl gene. Conclusion: Acetylation inhibitor SAHA promoted the expression of miR-192 and miR-6816 in K562 cells by acetylation regulation, miR-192 and miR-6816 further down-regulated the transcription of Bcr-Abl gene, thereby inhibiting K562 cell proliferation and induced apoptosis.

Influence of arginine on the growth, arginine metabolism and amino acid consumption profiles of Streptococcus thermophilus T1C2 in controlled pH batch fermentations.

AIMS: The aim of this study was to elucidate the effect of arginine on the growth, arginine metabolism and amino acid consumption profiles of Streptococcus thermophilus T1C2. METHODS AND RESULTS: The growth kinetics, intracellular pH, extracellular osmotic pressure, expression of key genes in the arginine metabolism pathway and amino acid consumption profiles were analysed in chemically defined medium with different initial arginine concentrations. The results showed that arginine stimulated the growth of Strep. thermophilus T1C2 under low intracellular pH and high extracellular osmotic pressure. The expression of key genes in the arginine degradation pathway indicated that arginine relieved the drop in the intracellular pH by consuming protons and generating NH3 . Additionally, the results showed that arginine degradation did not occur via the arginine deiminase pathway but through the arginine decarboxylase-urease pathway. Furthermore, the utilization efficiency of amino acids was improved in the presence of arginine. CONCLUSIONS: Arginine improved the growth of Strep. thermophilus due to protecting Strep. thermophilus against intracellular acid stress, which was revealed at the transcriptional level of key genes. This study showed that the acid resistance of Strep. thermophilus was achieved through the arginine decarboxylase-urease pathway. SIGNIFICANCE AND IMPACT OF THE STUDY: The arginine-stimulated growth of Strep. thermophilus improved the utilization efficiency of amino acids and reduced nitrogen waste, which could be useful for the optimization of cultivation media.

Evaluation of autochthonous micrococcus strains as starter cultures for the production of Kedong sufu.

AIMS: The technological properties of 22 micrococcus strains from traditional fermented Kedong sufu were evaluated in order to develop autochthonous starter cultures. METHODS AND RESULTS: The proteolytic, autolytic and lipolytic activity, salt tolerance, production and degradation of the biogenic amines of six Micrococcus luteus, nine Kocuria kristinae and seven Kocuria rosea were evaluated. The results indicated that these micrococcus strains exhibited a certain technological diversity, and the results also indicated the best properties to be used in mixed starter cultures. Based on the above findings, two sets of autochthonous starters were formulated. Considering the physicochemical properties and sensory characteristics of sufu, the maturation period of sufu was shortened by 30 days. The profiles of free amino acids and peptides partly revealed the mechanism of sensory quality and shorter ripening time of sufu manufactured using autochthonous mixed starters. Compared to back-slopping fermentation, sufu manufactured with selected autochthonous starter cultures exhibited lower levels of total biogenic amines. CONCLUSIONS: The selected strains could be used as starter to avoid the accumulation of high concentrations of biogenic amines while also maintaining typical sensory characteristics and preserving the autochthonous strains of the traditional Kedong sufu. The maturation times of Kedong sufu were shortened by 30 days with application of the autochthonous starter. SIGNIFICANCE AND IMPACT OF THE STUDY: Autochthonous mixed starters can reduce the generation of biogenic amines, speed up the sufu maturation process and preserve typical sensory quality. Furthermore, the rotation of two sets of mixed starter cultures can effectively resist phage attack during the production of sufu.

Large eddy simulation of wind-induced interunit dispersion around multistory buildings.

Previous studies regarding interunit dispersion used Reynolds-averaged Navier-Stokes (RANS) models and thus obtained only mean dispersion routes and re-entry ratios. Given that the envelope flow around a building is highly fluctuating, mean values could be insufficient to describe interunit dispersion. This study investigates the wind-induced interunit dispersion around multistory buildings using the large eddy simulation (LES) method. This is the first time interunit dispersion has been investigated transiently using a LES model. The quality of the selected LES model is seriously assured through both experimental validation and sensitivity analyses. Two aspects are paid special attention: (i) comparison of dispersion routes with those provided by previous RANS simulations and (ii) comparison of timescales with those of natural ventilation and the survival times of pathogens. The LES results reveal larger dispersion scopes than the RANS results. Such larger scopes could be caused by the fluctuating and stochastic nature of envelope flows, which, however, is canceled out by the inherent Reynolds-averaged treatment of RANS models. The timescales of interunit dispersion are comparable with those of natural ventilation. They are much shorter than the survival time of most pathogens under ordinary physical environments, indicating that interunit dispersion is a valid route for disease transmission.

From street canyon microclimate to indoor environmental quality in naturally ventilated urban buildings: Issues and possibilities for improvement.

Many buildings in urban areas are more or less naturally ventilated. A good understanding of the current status and issues of indoor environmental quality (IEQ) in naturally ventilated urban buildings and the association with urban microclimate is fundamental for improving their IEQ. This paper reviews past studies on (a) the microclimate in urban street canyons, (b) the potential influence of such microclimate on IEQ of nearby naturally ventilated buildings, and (c) the real-life IEQ status in these buildings. The review focuses mainly on studies conducted by on-site measurements. The microclimate in urban street canyons is characterized by low wind speed, high surface temperature difference, high pollutant concentration, and high noise level. Insufficient ventilation rates and excessive penetration of outdoor pollutants are two key risks involved in naturally ventilated urban buildings. Existing knowledge suggests that reasonable urban planning and careful building envelope design are the primary methods to ensure acceptable IEQ and maximize the utilization of natural ventilation. However, quantitative studies of both microclimate in street canyons and IEQ in buildings are still highly insufficient in many aspects, which make cross comparison and influencing factors analysis currently impossible. Based on the limitations of previous studies and the current issues of naturally ventilated urban buildings, suggestions are made for future studies to better understand and improve IEQ in naturally ventilated urban buildings.

Suppression of RNA interference on expression of c-myc of SKOV3 ovarian carcinoma cell line.

AIM: To investigate suppression of RNA interference (RNAi) on expression of c-myc of SKOV3 ovarian carcinoma cell line. MATERIALS AND METHODS: The c-myc -siRNA was designed and synthesized, then transfected to SKOV3 ovarian carcinoma cell lines. The cell lines were divided into four groups, including the blank control group, the siRNA transfection group, the mock transfection group and the negative control group. The expression level of c-myc mRNA and protein were detected by RT-PCR and Western blotting, respectively. The growth and proliferation of SKOV3 ovarian carcinoma cell lines were observed with CCK-8 assay. RESULTS: After transfected with c-myc -siRNA, the expression level of c-myc mRNA and protein were down-regulated, the growth and proliferation of SKOV3 ovarian carcinoma cell line were inhibited in the siRNA transfection group. There were significant differences between the siRNA transfection group and the blank control group (p < 0.05). The silencing efficiency was 77.78%, the protein suppression rate was 67.78%, and the inhibition ratio was 56.35% by CCK-8 assay in siRNA transfection group. CONCLUSIONS: The down-regulation of c-myc expression of SKOV3 ovarian carcinoma cell line by c-myc -siRNA can lead to the suppression of cancer cell proliferation. The small interfering RNAs technique can inhibit the proliferation of carcinoma cell by oncogene silencing.

Numerical investigation of wind-induced airflow and interunit dispersion characteristics in multistory residential buildings.

Compared with the buoyancy-dominated upward spread, the interunit dispersion of pollutants in wind-dominated conditions is expected to be more complex and multiple. The aim of this study is to investigate the wind-induced airflow and interunit pollutant dispersion in typical multistory residential buildings using computational fluid dynamics. The mathematical model used is the nonstandard k-ε model incorporated with a two-layer near-wall modification, which is validated against experiments of previous investigators. Using tracer gas technique, the reentry of exhaust air from each distinct unit to other units on the same building, under different practical conditions, is quantified, and then, the possible dispersion routes are revealed. The units on the floor immediately below the source on the windward side, and vertically above it on the leeward side, where the reentry ratios are up to 4.8% and 14.9%, respectively, should be included on the high-infection list. It is also found that the presence of balconies results in a more turbulent near-wall flow field, which in turn significantly changes the reentry characteristics. Comparison of the dispersion characteristics of the slab-like building and the more complicated building in cross (#) floorplan concludes that distinctive infectious control measures should be implemented in these two types of buildings.

Pressure losses across multiple fittings in ventilation ducts.

The accurate prediction of pressure losses across in-duct fittings is of significance in relation to the accurate sizing and good energy efficiency of air-delivery systems. Current design guides provide design methods and data for the prediction of pressure losses only for a single and isolated fitting. This study presents an investigation of pressure losses across multiple interactive in-duct fittings in a ventilation duct. A laboratory measurement of pressure losses across one fitting and multiple fittings in a ventilation duct is carried out. The pressure loss across multiple interactive fittings is lower than that across multiple similar individual fittings, while the percentage decrease is dependent on the configuration and combination of the fittings. This implies that the pressure loss across multiple closely mounted fittings calculated by summing the pressure losses across individual fittings, as provided in the ASHRAE handbook and the CIBSE guide, is overpredicted. The numerical prediction of the pressure losses across multiple fittings using the large-eddy simulation (LES) model shows good agreement with the measured data, suggesting that this model is a useful tool in ductwork design and can help to save experimental resources and improve experimental accuracy and reliability.

The role of hepatic liver X receptor α- and sterol regulatory element binding protein-1c-mediated lipid disorder in the pathogenesis of non-alcoholic steatohepatitis in rats.

Liver X receptor α (LXRα) and sterol regulatory element binding protein-1c (SREBP-1c) were studied in rats with non-alcoholic steatohepatitis (NASH) induced by a high-fat diet. Forty 5-week-old rats were fed either a high-fat diet (n = 30) or a normal diet (n = 10) for 9, 13 or 17 weeks. The mRNA and protein levels for LXRα and SREBP-1c were measured at each time point, as was fatty acid synthase (FAS) activity and the serum levels of free fatty acid (FFA) and triglyceride (TG). The mRNA and protein levels for LXRα and SREBP-1c, FAS activity and serum levels of FFA and TG all significantly increased from week 9 in the high-fat diet rats versus controls. In conclusion, a high-fat diet upregulates LXRα which, in turn, upregulates SREBP-1c, increasing the activity of FAS and FFA and accumulation of TG in hepatocytes. Thus, LXRα and SREBP-1c contribute to the development of NASH.

The association of metabolic syndrome with reflux esophagitis: a case-control study.

BACKGROUND: Obesity has been associated with reflux esophagitis. However, the association of metabolic syndrome with reflux esophagitis remains unknown. METHODS: A case-control study of 372 subjects undergoing upper endoscopy during health checkups was conducted (182 patients with reflux esophagitis vs 190 age and gender-matched controls). We further measured their height, weight, waist circumference, hip circumference, blood pressure, triglyceride, high-density lipoprotein, and fasting blood glucose. Multivariable linear regression analysis was used to identify the independent risk factors associated with the presence of reflux esophagitis. KEY RESULTS: Reflux esophagitis cases showed higher mean waist circumference (81.37 ± 0.68 vs 79.36 ± 0.70, P < 0.05), waist hip ratio (0.86 ± 0.01 vs 0.84 ± 0.01, P < 0.05) and fasting blood glucose (5.59 ± 0.10 vs 5.32 ± 0.08, P < 0.05) than those in controls. When adjusted for gender and age, multivariate analysis demonstrated that there was a positive dose-response relationship between reflux esophagitis and waist hip ratio (men: OR 3.41, 95% CI 1.52-7.62, women: OR 3.37, 95% CI 1.61-7.06), triglyceride (OR 2.07, 95% CI 1.12-3.82), fasting blood glucose (OR 1.81, 95% CI 1.12-2.94), and metabolic syndrome (OR 2.01, 95% CI 1.15-3.50), there was an inverse dose-response relationship between reflux esophagitis and high-density lipoprotein for men (OR 0.36, 95% CI 0.15-0.85). CONCLUSIONS & INFERENCES: High waist hip ratio, triglyceride, fasting blood glucose, and metabolic syndrome were associated with increased risk factors for reflux esophagitis while high high-density lipoprotein for men correlated with a reduced risk of reflux esophagitis.

The prophylactic effects of platelet-leucocyte gel in osteomyelitis: an experimental study in a rabbit model.

Platelet-leucocyte gel (PLG), a new biotechnological blood product, has hitherto been used primarily to treat chronic ulcers and to promote soft-tissue and bone regeneration in a wide range of medical fields. In this study, the antimicrobial efficacy of PLG against Staphylococcus aureus (ATCC 25923) was investigated in a rabbit model of osteomyelitis. Autologous PLG was injected into the tibial canal after inoculation with Staph. aureus. The prophylactic efficacy of PLG was evaluated by microbiological, radiological and histological examination. Animal groups included a treatment group that received systemic cefazolin and a control group that received no treatment. Treatment with PLG or cefazolin significantly reduced radiological and histological severity scores compared to the control group. This result was confirmed by a significant reduction in the infection rate and the number of viable bacteria. Although not comparable to cefazolin, PLG exhibited antimicrobial efficacy in vivo and therefore represents a novel strategy to prevent bone infection in humans.

Antineoplastic mechanism of Octreotide action in human hepatoma.

OBJECTIVES: To investigate whether apoptosis can be induced by Octreotide in human hepatoma cells in vitro and elucidate the antineoplastic mechanism of Octreotide in hepatoma. METHODS: A cultured human hepatoma cell line, BEL-7402, was exposed to Octreotide and apoptosis was evaluated by cytochemical staining (Hochesst 33,258), transmission electron microscopy, agarose gel electrophoresis and flow cytometry (FCM). RESULTS: After exposure to 0.2 microgram/ml Octreotide, apoptosis with nuclear chromatin condensation as well as fragmentation, cell shrinkage and the formation of apoptotic bodies was observed using cytochemical staining and transmission electron microscopy. A DNA ladder in agarose gel electrophoresis was also displayed. FCM showed that the apoptotic cell number rose with an increase in the concentration of Octreotide (0-2 micrograms/ml). There was a positive correlation between Octreotide concentration and apoptotic rate in BEL-7402 cells (r = 0.809, P < 0.05). CONCLUSION: Apoptosis in human hepatoma cells can be induced by Octreotide, which may be related to the mechanism of antineoplastic action of Octreotide in hepatoma.

Manipulation of volumetric patient data in a distributed virtual reality environment.

Due to increases in network speed and bandwidth, distributed exploration of medical data in immersive Virtual Reality (VR) environments is becoming increasingly feasible. The volumetric display of radiological data in such environments presents a unique set of challenges. The shear size and complexity of the datasets involved not only make them difficult to transmit to remote sites, but these datasets also require extensive user interaction in order to make them understandable to the investigator and manageable to the rendering hardware. A sophisticated VR user interface is required in order for the clinician to focus on the aspects of the data that will provide educational and/or diagnostic insight. We will describe a software system of data acquisition, data display, Tele-Immersion, and data manipulation that supports interactive, collaborative investigation of large radiological datasets. The hardware required in this strategy is still at the high-end of the graphics workstation market. Future software ports to Linux and NT, along with the rapid development of PC graphics cards, open the possibility for later work with Linux or NT PCs and PC clusters.