Social Determinants of Health and Patients' Technology Acceptance of Telehealth During the COVID-19 Pandemic: Pilot Survey

BACKGROUND

Telehealth has been widely adopted by patients during the COVID-19 pandemic. Many social determinants of health influence the adoption.

OBJECTIVE

This pilot study aimed to understand the social determinants of patients' adoption of telehealth in the context of the pandemic.

METHODS

A survey methodology was used to capture data from 215 participants using Amazon Mechanical Turk. The study was guided by the technology acceptance model and the social determinants of health framework. The questionnaire included technology acceptance model variables (eg, perceived usefulness [PU] and perceived ease of use [PEOU]), social determinants (eg, access to health care, socioeconomic status, education, and health literacy), and demographic information (eg, age, sex, race, and ethnicity). A series of ordinary least squares regressions were conducted to analyze the data using SPSS Statistics (IBM Corp).

RESULTS

The results showed that social determinant factors-safe neighborhood and built environment (P=.01) and economic stability (P=.05)-are predictors of the PEOU of telehealth adoption at a statistically significant or marginally statistically significant level. Furthermore, a moderated mediation model (PROCESS model 85) was used to analyze the effects of COVID-19 on the neighborhood, built environment, and economic stability. PEOU and PU significantly positively affected users' intention to use technology for both variables.

CONCLUSIONS

This study draws attention to 2 research frameworks that address unequal access to health technologies. It also adds empirical evidence to telehealth research on the adoption of patient technology. Finally, regarding practical implications, this study will provide government agencies, health care organizations, and health care companies with a better perspective of patients' digital health use. This will further guide them in designing better technology by considering factors such as social determinants of health.

Cascading Crises: Society in the Age of COVID-19

The tsunami of change triggered by the COVID-19 pandemic has transformed society in a series of cascading crises. Unlike disasters that are more temporarily and spatially bounded, the pandemic has continued to expand across time and space for over a year, leaving an unusually broad range of second-order and third-order harms in its wake. Globally, the unusual conditions of the pandemic-unlike other crises-have impacted almost every facet of our lives. The pandemic has deepened existing inequalities and created new vulnerabilities related to social isolation, incarceration, involuntary exclusion from the labor market, diminished economic opportunity, life-and-death risk in the workplace, and a host of emergent digital, emotional, and economic divides. In tandem, many less advantaged individuals and groups have suffered disproportionate hardship related to the pandemic in the form of fear and anxiety, exposure to misinformation, and the effects of the politicization of the crisis. Many of these phenomena will have a long tail that we are only beginning to understand. Nonetheless, the research also offers evidence of resilience on several fronts including nimble organizational response, emergent communication practices, spontaneous solidarity, and the power of hope. While we do not know what the post COVID-19 world will look like, the scholarship here tells us that the virus has not exhausted society's adaptive potential.

Acute Treatment of Migraine: What has Changed in Pharmacotherapies?

Background

Migraine is the most prevalent neurological disorder and the leading cause of disability in individuals under 50 years of age. Two types of migraine therapies have been defined: acute therapy (abortive or symptomatic treatment), the purpose of which is to interrupt migraine attacks, and preventive treatment (prophylactic treatment), the purpose of which is to reduce the frequency and severity of migraine attacks.

Objective

This paper reviews research advances in new agents for acute therapy of migraine.

Material and Methods

This review provides an overview of emerging new drugs for acute treatment of migraine based on clinical evidence and summarizes the milestones of different stages of clinical development.

Results

Two new formulations of sumatriptan, DFN-11 (3 mg doses of subcutaneous sumatriptan) and DFN-02 (a nasal spray of sumatriptan 10 mg and a permeation-enhancing excipient), have been developed, and both of them showed a fast-onset action with efficacy for acute treatment of migraine with fewer adverse events. New drug discovery programs shifted the focus to the development of ditans, a group of antimigraine drugs targeting 5-HT_1F receptors. Only lasmiditan has progressed to phase III clinical trials and was finally approved by the Food and Drug Administration (FDA) for acute migraine treatment. The other target for acute therapy is CGRP receptor antagonists, namely, gepants. Ubrogepant and rimegepant demonstrated statistically significant efficacy, and both were recently approved by the FDA. These 5-HT_1F receptor agonists and CGRP receptor antagonists did not cause vasoconstriction, offering advantages over the current mainstay of specific acute migraine treatment.

Conclusions

Overall, these new agents have expanded the available acute therapies for migraine treatment and will likely change the strategy with which we treat patients with migraine in the future.

Feasibility of a Computer Role-Playing Game to Promote Empathy in Nursing Students: The Role of Immersiveness and Perspective

Empathy is considered a cornerstone of high-quality health care and a required element of nursing education. Although computer role-playing games (CRPGs) are a promising tool to promote clinical empathy, little is known about how and why it is effective at improving empathy. The goal of the current study is to investigate the feasibility and effectiveness of a CRPG on nursing students' empathy with a focus on immersiveness and perspective. Results from a 2 × 2 (virtual reality [VR] vs. non-VR × patient's family's perspective vs. health care provider's perspective) between-subjects experiment (N = 69) showed that playing the game in VR (vs. non-VR) led to greater spatial presence and empathy. Moreover, playing from the health care provider's (vs. patient's family's) perspective elicited greater empathy. A moderated mediation effect was found, suggesting that users' attention allocation significantly mediated the effect of immersiveness on empathy in the patient's family's perspective condition. These findings show the feasibility of using a role-playing game for nursing education. Both theoretical and practical implications involving empathy training were discussed, along with suggestions for further research.

Exergaming Executive Functions: An Immersive Virtual Reality-Based Cognitive Training for Adults Aged 50 and Older

Prior research suggests that both exergaming and virtual reality (VR)-based training programs could improve executive functions in older adults. However, few studies investigated whether combining exergaming with VR would be more effective. This study seeks to (a) investigate whether playing exergames in an immersive virtual environment (IVE) would yield differential outcomes in selected executive functions, including inhibition, task switching, and working, and (b) examine the role of feeling of presence as a potential mediator between immersive exergaming and cognitive improvement in specific domains. Thirty-three participants over 50 years of age (mean age = 62) participated in a 4-week training program and were randomly assigned into an IVE and non-IVE to play an exergame (Fruit Ninja) for eight sessions within 4 weeks. The results revealed a significant effect of the IVE on the Stroop Test and Trail Making Test after the 4-week training. Furthermore, the impacts of the IVE exergaming on these two tasks were mediated by the feeling of presence. These findings suggested that the immersive experience of exergaming would elicit the feeling of presence, which later contributes to improved cognitive performances in inhibition and task switching. For the theoretical implications, this study extends previous research by showing that (a) feeling of presence could contribute to older adults' cognitive improvement, and (b) the impacts of immersive exergame training on executive functions vary across individual domains. Additionally, this study provides practical implications such that the design of exergames could emphasize the game features requiring mental simulation, which can serve as a novel strategy for preventing cognitive decline in midlife and old age.

Augmented Versus Virtual Reality in Education: An Exploratory Study Examining Science Knowledge Retention When Using Augmented Reality/Virtual Reality Mobile Applications

The propagation of augmented reality (AR) and virtual reality (VR) applications that leverage smartphone technology has increased along with the ubiquity of smartphone adoption. Although AR and VR technologies have been widely utilized in the educational domain, there remains a dearth of empirical research examining the differences in educational impact across AR and VR technologies. The purpose of our exploratory study was to address this gap in the literature by comparing AR and VR technologies with regard to their impact on learning outcomes, such as retention of science information. Specifically, we use a two-condition (AR vs. VR) between-subjects' design to test college students' science-knowledge retention in response to both auditory and visual information presented on a Samsung S4 smartphone app. Our results (N = 109) suggest that VR is more immersive and engaging through the mechanism of spatial presence. However, AR seems to be a more effective medium for conveying auditory information through the pathway of spatial presence, possibly because of increased cognitive demands associated with immersive experiences. Thus, an important implication for design is that educational content should be integrated into visual modalities when the experience will be consumed in VR, but into auditory modalities when it will be consumed in AR.

The Physical-Digital Divide: Exploring the Social Gap Between Digital Natives and Physical Natives

Older adults are the most digitally divided demographic group. The present study explores how older adults perceive the physical use of information and communication technologies (ICTs), particularly across generations and contexts. Data for the present study come from nine focus groups. Seniors acknowledge that ICTs help them connect with geographically distant social ties, but that they lead to feelings of disconnection with geographically close social ties. We label this phenomenon the "physical-digital divide," which exists when a group feels ostracized or offended when those around them engage with ICTs while they themselves are not or cannot engage with ICTs. Younger generations are often referred to as "digital natives" and older generations as "digital immigrants." A more apt label for older adults may be "physical natives," as their preferred method of communication involves physical face-to-face interactions and traditional codes of etiquette. Suggestions are made for reducing the physical-digital divide.

Biaxial stress and optoelectronic properties of Al-doped ZnO thin films deposited on flexible substrates by radio frequency magnetron sputtering

Transparent conductive Al-doped ZnO (AZO) thin films were deposited on polyethylene terephthalate (PET) and polycarbonate (PC) substrates using radio frequency (RF) magnetron sputtering. The biaxial stress was measured with a double beam shadow moiré interferometer, and x-ray diffraction (XRD) was used to investigate the crystal orientation of ZnO. The substrate temperature was varied from room temperature to 150°C in steps of 25°C. The experimental results showed that the residual and shearing stresses increased with the increase in substrate temperature. The residual stress can be separated into principle and shearing stresses by Mohr's circle rule, and the shearing stress (tensile stress) was different from the compressive stress of the residual stress. However, the optimal substrate temperatures for PET and PC were 75°C and 100°C, and the shearing stresses were 424.82 and 543.68 MPa, respectively. AZO/PET and AZO/PC thin films cracked at substrate temperatures of 75°C and 100°C, respectively. AZO/PET thin film at a substrate temperature of 100°C had a resistivity low to the order of 10^-3  Ω-cm.

Rapid Mass Spectrometry Imaging to Assess the Biochemical Profile of Pituitary Tissue for Potential Intraoperative Usage

Pituitary adenomas are relatively common intracranial neoplasms that are frequently treated with surgical resection. Rapid visualization of pituitary tissue remains a challenge as current techniques either produce little to no information on hormone-secreting function or are too slow to practically aid in intraoperative or even perioperative decision-making. Matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI MSI) represents a powerful method by which molecular maps of tissue samples can be created, yielding a two-dimensional representation of the expression patterns of small molecules and proteins from biologic samples. In this chapter, we review the use of MALDI MSI, its application to the characterization of the pituitary gland, and its potential applications for guiding the management of pituitary adenomas.

Thorn-like ZnO/CNT composites via the hydrothermal method with different seed layer

This paper studies the preparation of a zinc oxide (ZnO) seed layer deposited onto carbon nanotubes (CNTs) via RF sputtering, and the growth of ZnO/CNT composite via the hydrothermal method. The ZnO "thorns" have been successfully deposited on CNT "stems." The research focuses on the ZnO seed layer with different sputtering times and annealing processes. A scanning electron microscopy (SEM) investigation showed that the length and amount of ZnO thorns decreased with increased sputtering time of the seed layer. The x-ray diffraction (XRD) results showed that the ZnO crystalline structures improved after the seed layer, annealing at peaks of (100), (002), and (101). The results of Raman spectra showed that the ZnO seed layer deposited onto the CNTs, and the annealing, caused damage to the CNTs, reducing the IG/ID ratio from 0.9 to 0.5. Furthermore, the highest UV emission of thorn-like ZnO/CNTs occurred at a peak of 380 nm with seed layer deposition time of 2 min, after annealing.

Electrochromic and optical properties of tungsten oxide films deposited with DC sputtering by introducing hydrogen

Research was undertaken to investigate the electrochromic and optical properties of tungsten oxide (WO3) films deposited by introducing hydrogen with a direct current (DC) and pulsed DC sputtering. The results show that WO3 films have optimum electrochromic properties at a hydrogen flow of 4 and 3 sccm for DC and pulsed DC, respectively. In the Raman spectra, the peak intensity increased with the increase of hydrogen flow at both 770  cm1 and 950  cm(-1) peaks, which resulted in bonds of W(6+)-O and W(6+)=O, respectively. Simultaneously, the transmittance (ΔT550  nm) variations were 65.6% and 64.4%, and the average transmittance (ΔT400-500  nm) variations were 56.7% and 56.4% for DC and pulsed DC, respectively. The bleached/colored ability of the cyclic voltammograms (CVs) was DC>pulsed DC, and the resistances of AC impedance were pulsed DC>DC.

miR-499A>G rs3746444 and miR-146aG>C expression and hepatocellular carcinoma risk in the Chinese population

We conducted a case-control study of a possible association of miR-499A>G rs3746444 and miR-146aG>C rs2910164 with risk of hepatocellular carcinoma. Samples from 172 hepatocellular carcinoma patients and 185 cancer-free controls were collected from October 2008 to December 2011. PCR-RFLP analysis was performed to determine the polymorphisms in each individual. The MAFs of miR-146aG>C and miR-499A>G in controls were similar to that known from the SNP database, and frequencies of genotypes in controls were in line with Hardy-Weinberg equilibrium. We found that miR-499 AG was significantly associated with decreased risk for hepatocellular carcinoma when compared with miR-499 AA genotype (adjusted odds ration = 0.74, 95% confidence interval = 0.24-0.96). However, subjects carrying miR-146a GG had a non-significant 0.62-fold decreased risk of hepatocellular carcinoma. We did not find a significant association of miR-146aG>C rs2910164 and miR-499A>G rs3746444 polymorphisms with hepatocellular carcinoma risk in the Chinese population. Further investigations are warranted to clarify the relationship between miRNA polymorphisms and susceptibility to hepatocellular carcinoma risk in various ethnic populations.

Spinal meningeal diverticula in spontaneous intracranial hypotension: analysis of prevalence and myelographic appearance

BACKGROUND AND PURPOSE

Spinal meningeal diverticula have been implicated in the pathogenesis of spontaneous intracranial hypotension and have been proposed as both diagnostic features of and therapeutic targets for the condition. We compared the prevalence and myelographic appearance of spinal diverticula in patients with SIH and healthy controls.

MATERIALS AND METHODS

Patients satisfying the ICHD-2 criteria for SIH were retrospectively identified. CT myelograms of 19 patients with SIH were compared with CT myelograms of 18 control patients. Images were reviewed by 2 blinded neuroradiologists. The prevalence, morphology (round versus multilobulated), size, and location (cervical, upper thoracic, lower thoracic, or lumbar) of spinal meningeal diverticula were analyzed.

RESULTS

There was no difference in the proportion of patients with diverticula in the SIH group compared with the control group (68% versus 44%, P = .14) or in the mean number of diverticula per patient (6.3 versus 2.2, P = .099). No difference was seen in the morphology (P = .95) or size (P = .71) of diverticula between groups. There was a difference between groups that just reached statistical significance (P = .050) in the location of the diverticula along the spinal axis, but substantial overlap was seen between groups for all spinal locations.

CONCLUSIONS

Despite the well-established association between spinal meningeal diverticula and SIH, we found no difference in the prevalence or myelographic appearance of diverticula in patients with SIH compared with controls. Further investigation into the role of diverticula in the diagnosis and treatment of SIH is necessary.

Measurement of residual stress for ITO/PET substrates by the double beam shadow moiré interferometer

This study constructed a measurement system that can quickly and accurately analyze the residual stress of flexible electronics. A double beam shadow moiré interferometer was set up to measure and evaluate the residual stress of tin-doped indium oxide films on a polyethylene terephthalate substrate. However, this system required only two symmetrical fringes to evaluate the residual stress of transparent conductive oxide films on flexible substrate. Applying the grating translation techniques to the double beam shadow moiré interferometer greatly improved the measurement resolution and accuracy, and the relative error was reduced to 1.2%.

Effect of Ag underlayer on microstructures and perpendicular magnetic properties of CoPt nanocomposite thin films

CoPt/Ag films were prepared by magnetron sputtering on glass substrates and subsequent annealing. The dependence of degree of ordering and magnetic properties on Ag film thickness and annealing conditions were investigated. It was found that the Ag underlayer played a dominant role in inducing the (001) texture of the CoPt film after annealing. CoPt films with a thickness about 20 nm and Ag underlayers with a thickness about 70 nm are easy to obtain a large degree of ordering and a perpendicular magnetic anisotropy after annealing at 700 degrees C for 30 min. CoPt/Ag films with out-of-plane coercivity (Hc (perpendicular)) in the range of 13.5-14.0 kOe and a out-of-plane squareness (S(perpendicular)) of 0.97 were obtained after annealing at 700 degrees C for 30 min. Ag underlayer is beneficial to enhance the Hc(perpendicular)and S(perpendicular) of CoPt film significantly. The degree of ordering and perpendicular magnetic properties of the CoPt films which deposited on Ag underlayer are larger than those of the single layer CoPt films.

Selection of a synthetic glycan oligomer from a library of DNA-templated fragments against DC-SIGN and inhibition of HIV gp120 binding to dendritic cells

We report the synthesis of a nucleic acid-encoded carbohydrate library, its combinatorial self-assembly into 37,485 pairs and a screen against DC-SIGN leading to the identification of consensus ligand motifs. A prototypical example from the selected pairs was shown to have enhanced binding. A dendrimer incorporating the selected motifs inhibited gp120's binding to dendritic cells with higher efficiency than mannan.

Multi-enzyme one-pot strategy for the synthesis of sialyl Lewis X-containing PSGL-1 glycopeptide

An enzymatic one-pot three-step glycosylation strategy was developed for the synthesis of sLex moiety of truncated PSGL-1 glycopeptide with and without sulfation. The method provided an efficient way to afford complex glycopeptides in a semi-preparative scale without further complicated and time-consuming purification process in each glycosylation step.

Tuning the conformation properties of a peptide by glycosylation and phosphorylation

We have deployed the alpha-helical hairpin peptide (alpha-helix/turn/alpha-helix) and used it as a model system to explore how glycosylation and phosphorylation might affect the conformational properties of the peptide. The native conformations of the modified peptides in buffer solution have been compared with that of the wild-type peptide by nuclear magnetic resonance spectroscopy. Circular dichroism spectroscopy was used to probe the effects of an O-linked beta-GlcNAc and a phosphate group on the overall folding stability of the peptide. Finally, the rate of fibrillogenesis was used to infer the effects of these chemical modifications on the alpha-to-beta transition as well as the rate of nucleation of amyloidogenesis.

N-Trifluoroacetyl Sialyl Phosphite Donors for the Synthesis of α(2 → 9) Oligosialic Acids

[reaction: see text] A new method for the synthesis of alpha(2 --> 9) oligosialic acids is developed using phosphite sialyl donors that are protected with a C-5 N-trifluoroacetyl (NHTFA) substituent. Compared with conventional donors, these donors gave a higher degree of alpha-anomeric selectivity during glycosidic bond formation and better yields during iterative sialylation in the synthesis of oligosialic acids.

Liquid-phase combinatorial synthesis of aminobenzimidazoles

Liquid-phase synthesis of 2-arylaminobenzimidazoles using soluble polymer support strategy is first described. The key step to benzimidazole skeleton is achieved in the presence of diisopropylcarbodimide (DICDI) and isothiocyanates. A mechanism study for one-pot cyclodesulfurization is also investigated on the support. A wide range of benzimidazole derivatives is synthesized in excellent yield and purity just by simple wash and precipitation.

Modulation of nitric oxide bioavailability by erythrocytes

Nitric oxide (NO) activates soluble guanylyl cyclase in smooth muscle cells to induce vasodilation in the vasculature. However, as hemoglobin (Hb) is an effective scavenger of NO and is present in high concentrations inside the red blood cell (RBC), the bioavailability of NO would be too low to elicit soluble guanylyl cyclase activation in the presence of blood. Therefore, NO bioactivity must be preserved. Here we present evidence suggesting that the RBC participates in the preservation of NO bioactivity by reducing NO influx. The NO uptake by RBCs was increased and decreased by altering the degree of band 3 binding to the cytoskeleton. Methemoglobin and denatured hemoglobin binding to the RBC membrane or cytoskeleton also were shown to contribute to reducing the NO uptake rate of the RBC. These alterations in NO uptake by the RBC, hence the NO bioavailability, were determined to correlate with the vasodilation of isolated blood vessels. Our observations suggest that RBC membrane and cytoskeleton associated NO-inert proteins provide a barrier for NO diffusion and thus account for the reduction in the NO uptake rate of RBCs.

Evidence for inhibition of low density lipoprotein oxidation and cholesterol accumulation by apolipoprotein H (beta2-glycoprotein I)

Low density lipoprotein (LDL) oxidation and lipid accumulation are thought to enhance the progression of atherosclerosis. Apolipoprotein H (apoH) has been implicated in the development of human atherosclerosis. However, the roles of apoH in the oxidative modification of LDL and cellular accumulation of lipid constituents remained uncharacterized. In this study, the level of plasma apoH was found to be significantly associated with the oxidative susceptibility of LDL in human subjects. Plasma levels of apoH were positively correlated with the lag time but negatively correlated with LDL oxidation rate in conjugated diene formation. By using a J774 A.1 macrophage culture system, we found that apoH could not only inhibit the formation of conjugated diene and thiobarbituric acid-reactive substances, but also reduce the electrophoretic mobility of oxidized LDL. Furthermore, apoH decreased cellular accumulation of cholesterol via a reduction in cholesterol influx and an increase in cholesterol efflux. This is the first demonstration that apoH appears to have "antioxidant"-like effects on LDL oxidation. The results also suggest that apoH can inhibit the translocation of cholesterol from extracellular pools to macrophages, suggesting that apoH may play an important role in the prevention of atherosclerosis.

Erythrocyte consumption of nitric oxide: competition experiment and model analysis

It is generally believed that the erythrocyte membrane is highly permeable to nitric oxide (NO). To prevent NO from freely entering and being scavenged by the red blood cell (RBC), it has been suggested that NO consumption is limited by the mass transfer resistance of the diffusion layer adjacent to the erythrocyte membrane. Recently, we (Vaughn et al. (2000). J. Biol. Chem. 275, 2342) presented an experimental technique that overcomes experimental diffusional limitations and showed that RBCs also possess a mechanism to slow nitric oxide uptake. Here, we present a mathematical analysis of this technique by modeling the NO uptake of a single cell. We obtain additional data (n = 33, total) by use of the competition experiment and, through application of the model, show that either the RBC membrane permeability to NO or the intracellular reaction rate between NO and hemoglobin (Hb) is at least 2000-fold lower than previously thought. As a result, RBCs react with NO at a rate three orders of magnitude slower than free oxyHb. This phenomena may play an important role in NO bioavailability.

Liquid-phase parallel synthesis of ureas

An efficient and general liquid-phase method has been developed for the synthesis of a piperazine containing urea library. Reactions of the polymer bound carbamoyl chloride with primary or secondary amines afford ureas at ambient temperature. Desired compounds are liberated from the polymer support under mild conditions in high yields and high purity by simple precipitation and washings.

Age-associated changes in interferon-gamma and interleukin-4 secretion by purified human CD4+ and CD8+ T cells

Aging is associated with a decline in immune function. Interferon-gamma (IFN-gamma) and interleukin-4 (IL-4), two important immune deviation-related cytokines, are mainly produced by type 1 and type 2 T cells, respectively. To investigate the age-associated changes in the secretion of these two cytokines, 20 elderly and 20 young subjects fulfilling the SENIEUR protocol were enrolled. The ratios of CD4+ to CD8+ T cells were not different between the two age groups. The CD4+ and CD8+ T cells were purified by a magnetic cell sorting system, and then activated by concurrent anti-CD3 and anti-CD28 stimulation. The released cytokines were determined by ELISA. Both the CD4+ and the CD8+ T cells of the elderly individuals secreted a significantly larger amount of IFN-gamma after activation. Profound IL-4 production by CD8+ T cells was observed in the older subjects compared with that of the young subjects. These data suggested that age-associated decrease in immunity may be related to an imbalance in the secretion of immune deviation cytokines. The number of IL-4-secreting CD8+ T cells (T cytotoxic 2) rose significantly in the older individuals. Our design also provided a useful way to differentiate the T cell subsets secreting the same cytokine, such as IFN-gamma-producing T helper 1 and T cytotoxic 1 cells.

Erythrocytes possess an intrinsic barrier to nitric oxide consumption

It has been reported that free hemoglobin (Hb) reacts with NO at an extremely high rate (K(Hb) approximately 10(7) M(-1) s(-1)) and that the red blood cell (RBC) membrane is highly permeable to NO. RBCs, however, react with NO 500-1000 times slower. This reduction of NO reaction rate by RBCs has been attributed to the extracellular diffusion limitation. To test whether additional limitations are also important, we designed a competition test, which allows the extracellular diffusion limitation to be distinguished from transmembrane or intracellular resistance. This test exploited the competition between free Hb and RBCs for NO generated in a homogenous phase by an NO donor. If the extracellular diffusion resistance is negligible, then the results would follow a kinetic model that assumes homogenous reaction without extracellular diffusion limitation. In this case, the measured effective reaction rate constant, K(RBC), would remain invariant of the hematocrit, extracellular-free Hb concentration, and NO donor concentration. Results show that the K(RBC) approaches a constant only when the hematocrit is greater than 10%, suggesting that at higher hematocrit, the extracellular diffusion resistance is negligible. Under such a condition, the NO consumption by RBCs is still 500-1000 times slower than that by free Hb. This result suggests that intrinsic RBC factors, such as transmembrane diffusion limitation or intracellular mechanisms, exist to reduce the NO consumption by RBCs.

Intravascular flow decreases erythrocyte consumption of nitric oxide

Nitric oxide (NO) produced by the endothelium diffuses both into the lumen and to the smooth muscle cells according to the concentration gradient in each direction. The extremely high reaction rate between NO and hemoglobin (Hb), k(Hb)= 3-5 x 10(7) M(-1).s(-1), suggests that most of the NO produced would be consumed by Hb in the red blood cells (RBCs), which then would block the biological effect of NO. Therefore, specific mechanisms must exist under physiological conditions to reduce the NO consumption by RBCs, in which the Hb concentration is very high (24 mM heme). By using isolated microvessels as a bioassay, here we show that physiological concentrations of RBCs in the presence of intravascular flow does not inhibit NO-mediated vessel dilation, suggesting that RBCs under this condition are not an NO scavenger. On the other hand, RBCs (50% hematocrit) without intravascular flow reduce NO-mediated dilation to serotonin by 30%. In contrast, free Hb (10 microM) completely inhibits NO-mediated dilation with or without intravascular flow. The effect of flow on NO consumption by RBCs may be attributed to the formation of an RBC-free zone near the vessel wall, which is caused by hydrodynamic forces on particles. Intravascular flow does not affect the reaction rate between NO and free Hb in the lumen, because the latter forms a homogeneous solution and is not subject to the hydrodynamic separation. However, intravascular flow only partially contributes to the reduced consumption of NO by RBCs, because without the flow, the NO consumption by RBCs is already about 3 orders of magnitude slower than free Hb.

Cef1p is a component of the Prp19p-associated complex and essential for pre-mRNA splicing

The Prp19p protein of the budding yeast Saccharomyces cerevisiae is an essential splicing factor and is associated with the spliceosome during the splicing reaction. We have previously shown that Prp19p is not tightly associated with small nuclear ribonucleoprotein particles but is associated with a protein complex consisting of at least eight protein components. By sequencing components of the affinity-purified complex, we have identified Cef1p as a component of the Prp19p-associated complex, Ntc85p. Cef1p could directly interact with Prp19p and was required for pre-mRNA splicing both in vivo and in vitro. The c-Myb DNA binding motif at the amino terminus of Cef1p was required for cellular growth but not for interaction of Cef1p with Prp19p or Cef1p self-interaction. We have identified a small region of 30 amino acid residues near the carboxyl terminus required for both cell viability and protein-protein interactions. Cef1p was associated with the spliceosome in the same manner as Prp19p, i.e. concomitant with or immediately after dissociation of U4. The anti-Cef1p antibody inhibited binding to the spliceosome of Cef1p, Prp19p, and at least three other components of the Prp19p-associated complex, suggesting that the Prp19p-associated complex is likely associated with the spliceosome and functions as an integral complex.

Preoperative ultrasound study in predicting lymph node metastasis for endometrial cancer patients

OBJECTIVE

The objective of this study was to evaluate the efficacy of preoperative ultrasound (US) findings such as tumor size, status of myometrial invasion, and intratumoral "resistance index" (RI) in predicting lymph node metastasis in endometrial carcinoma patients.

METHODS

Forty-two patients with endometrial cancer were enrolled. All patients underwent total abdominal hysterectomy, pelvic lymph node dissection or sampling, and para-aortic lymph node sampling. Two-dimensional and color Doppler US were performed before surgery to measure tumor size, depth of myometrial invasion, and intratumoral arterial RI. Formalin-fixed, paraffin-embedded pathologic slides from surgical specimens were reviewed by a senior pathologist to evaluate histologic type and grade, depth of myometrial invasion, cervical involvement, lymph-vascular emboli, and status of lymph node metastasis.

RESULTS

There were 12 patients with pelvic and/or para-aortic lymph node metastases and 30 patients without nodal metastases. Patients with tumors larger than 2.5 cm by US (11/12 vs 14/30, P = 0.008), more than half myometrial invasion by US (9/12 vs 5/30, P < 0.001), and intratumoral RI values less than 0.4 by US (12/12 vs 4/30, P < 0.001) had a significantly higher incidence of nodal metastases as compared with patients with tumors smaller than 2.5 cm, no or superficial myometrial invasion, and RI values higher than 0.4, respectively. Multiple regression analysis showed that only intratumoral RI values less than 0.4 were significantly correlated with nodal metastasis (P < 0.001, r2 = 0. 650). We used the intratumoral RI value as the parameter to evaluate nodal metastasis in endometrial cancer patients. Twelve of sixteen patients with intratumoral RI values <0.4 had a high incidence of nodal metastases. None of the 26 patients with intratumoral RI values >0.4 had nodal metastases.

CONCLUSIONS

Preoperative ultrasound features can offer important information for predicting lymph node metastasis in endometrial cancer patients. Patients with tumors with intratumoral RI values less than 0.4 should be highly suspected of having lymph node metastases and further management such as pelvic lymph node dissection or postoperative pelvic radiotherapy would be needed for these patients.

Clinical application of intratumoral blood flow study in patients with endometrial carcinoma

BACKGROUND

The objective of this study was to evaluate the correlation between intratumoral blood flow as assessed by color Doppler ultrasound with stage, tumor grade, depth of invasion, and lymph node metastasis in endometrial carcinoma and determine its clinical usefulness.

METHODS

Sixty-six patients with endometrial carcinoma were enrolled. All patients received surgical treatment. Transvaginal color Doppler ultrasound was performed before surgery to detect the arterial blood flow signals within the tumors and the lowest resistance index (RI) was recorded. Formalin fixed, paraffin embedded pathology slides were reviewed by a senior pathologist to evaluate the histologic grading, tumor size, depth of myometrial invasion, and presence of lymph node metastasis.

RESULTS

Intratumoral RI correlated well with surgical staging, histologic grading, the depth of myometrial invasion, and the presence of lymph node metastasis. Significantly lower RI was noted in tumors of advanced stage (> than International Federation of Obstetrics and Gynecology [FIGO] Stage I) (0.38 +/- 0.09 vs. 0.54 +/- 0.11; P < 0.001), tumors with higher histologic grade (Grade 3) (0.36 +/- 0.08 vs. 0.53 +/- 0.11; P < 0.001), tumors with deep myometrial invasion (> 50% myometrial thickness) (0.38 +/- 0.07 vs. 0.54 +/- 0.11; P < 0.001), and tumors with lymph node metastasis (0.34 +/- 0.07 vs. 0.52 +/- 0.11; P < 0.001) compared with tumors with Stage I, Grade 1/2 histology, no or superficial myometrial invasion, and absence of lymph node metastasis, respectively.

CONCLUSIONS

Intratumoral blood flow analysis assessed by color Doppler ultrasound correlates well with surgical stage, tumor grade, myometrial invasion, and lymph node metastasis in patients with endometrial carcinoma. Assessment of tumor angiogenesis using color Doppler ultrasound provides useful information for the preoperative prediction regarding stage, histologic grade, depth of myometrial invasion, and presence of lymph node metastasis in patients with endometrial carcinoma. The authors believe routine pelvic lymph node dissection should be performed for those patients whose lowest RI values of intratumoral blood flow are < or = 0.4 because those patients are at very high risk for pelvic lymph node involvement.

Lipopolysaccharide activates endothelial nitric oxide synthase through protein tyrosine kinase

Vascular endothelial cell injury or activation by lipopolysaccharide (LPS) plays an important role in the pathogenesis of endotoxin shock. However, the effect of LPS on NO production from vascular endothelial cells (ECs) is incompletely understood. In this study, bovine coronary venular ECs were treated with LPS and the release of NO and expression of the endothelial NO synthase (ecNOS) were examined. We found that the ecNOS activity is transiently enhanced by LPS within the time scale of about 10 h due to the interplay between two LPS-induced mechanisms. Within the first 10 h of LPS treatment, the specific activity of ecNOS is increased by a post-translational modification mediated through a protein tyrosine kinase cascade. After about 10 h of treatment, however, LPS destabilizes the transcript of ecNOS and thus decreased the expression level and total activity.

Endometrial stromal sarcoma of twenty cases

BACKGROUND

Endometrial stromal sarcoma is a rare neoplasm. We reviewed twenty cases to study the characteristics of this disease.

METHODS

Twenty cases of endometrial stromal sarcoma were treated at our hospital. The clinical stage, treatment and outcome were retrospectively analyzed.

RESULTS

Endometrial stromal sarcoma comprised 4.3% of corpus cancers and 46.4% of uterine sarcomas at our hospital. Seven cases were stage I, one was stage II, ten were stage III, and two were stage IV at the time of diagnosis. Histopathologically, seventeen cases were classified as low-grade sarcoma and three were high-grade sarcoma. Seven patients had recurrence and five of them had already died of disease. Among these recurrent patients, one was stage II and six were stage III. All three patients with high-grade sarcoma and four with low-grade sarcoma had recurrence.

CONCLUSIONS

We think mitotic count is an important prognostic factor in low-grade endometrial stromal sarcoma and high-grade endometrial stromal sarcoma has a poor prognosis even with post-operative adjuvant treatment.

Sonographic characteristics of adenofibroma of the endometrium following tamoxifen therapy for breast cancer: two case reports

Adenofibroma of the endometrium is thought to be a rare benign variant of the mixed mesodermal tumor, and its preoperative diagnosis is difficult. We describe the sonographic characteristics of two cases of adenofibroma of the endometrium. In both cases the patient was receiving prolonged tamoxifen therapy following surgery for breast cancer. Sonographically, this rare disease is observed as an intracavitary mass containing multiple small cysts with low-resistance intratumor blood flow. The unique sonographic findings make the preoperative diagnosis possible.

Functional association of essential splicing factor(s) with PRP19 in a protein complex

We have previously shown that the yeast PRP19 protein is a spliceosomal component, but is not tightly associated with small nuclear RNAs. It appears to associate with the spliceosome concomitant with or just after dissociation of the U4 small nuclear RNA during spliceosome assembly. We have found that PRP19 is associated with a protein complex in the splicing extract and that at least one of the associated components is essential for splicing. Taking advantage of the epitope tagging technique, we have isolated the PRP19-associated complex by affinity chromatography. The isolated complex is functional for complementation for the heat-inactivated prp19 mutant extract, and consists of at least seven polypeptides in addition to PRP19. At least three of these can interact directly with the PRP19 protein. We also show that the PRP19 protein itself is in an oligomeric form, which might be a prerequisite for its interaction with these proteins.