The Scope of Medicare Reimbursement for New Medical Devices: Impact on Device Availability and the Standard of Care

Evolving standards of care motivated by advances in medical technology alter the characteristics and costs of delivered health care. Faced with shifting reimbursement demands, the Health Care Financing Administration (HCFA) has promulgated regulations setting forth criteria and procedures for making coverage decisions about health care technology and setting prospective payment limits for health care services including those related to new technology. The effects of such regulations extend beyond the Medicare program due to the tendency of other health insurers to mirror HCFA coverage, the impact of Medicare payments on cross-subsidization and other effects of Medicare reimbursement decisions on the demand for and supply of health care. The principle statutory authority for rules limiting coverage of health care technology is Section 1862(a)( 1) of the Social Security Amendments of 1965 (codified in 42 U.S.C. § 1395y(a)( 1)) which provides that no Medicare payment shall be made for items or services, including medical devices, "which are not reasonable and necessary for the diagnosis or treatment of illness or injury or to improve the functioning of a malformed body member." In 1989 HCFA proposed a rule describing criteria and procedures for health care technology Medicare coverage decisions. The rule defines a reasonable and necessary service as one which is safe and effective, cost-effective, appropriate, and not experimental or investigational. A provision of the rule categorizes a medical device that has not been approved by the FDA as experimental or investigational and hence not reimbursible under the reasonable and necessary standard. In this paper I will (1) consider the legal force and implications of the provision excluding Medicare coverage of all unapproved medical devices, (2) discuss HCFA's recent efforts to investigate billing for investigational cardiac devices, (3) consider the impact of reimbursement for investigational device on device availability and (4) consider ways to reconcile prudent control of health care expenditures with expeditious promotion of high standards of health care

Modulated contrast and associated diffracted intensity of GaPySb1-y layers grown using organometallic vapor phase epitaxy

Journal ArticleWe have investigated the modulated structures and its associated diffracted diff_x000B_use intensity, of organometallic vapor phase epitaxially grown GaPSb (001) layers by using transmission electron microscopy (TEM) and transmission electron diff_x000B_raction (TED). The TEM results reveal the co-existence of a _x000C_fine-scale modulated contrast and a _x000C_fine-scale speckled contrast. In addition, a _x000C_fine needle-like contrast is observed. The [001] TED results show lines of [110]-oriented diff_x000B_use intensity diffuse streaks passing through the fundamental reflections, satellite spots at 1/4g[220] positions, and a [010]-oriented diff_x000B_use intensity with spacing of 1/6g[040]. Simulations using the Valence Force Field model were performed to understand the origin of the di_x000B_ffracted features. The observed distributions of di_x000B_ffuse intensity are shown to be partially consistent with random disorder. Furthermore, the [110]-oriented diff_x000B_use lines are attributed to a static displacement of the sites of the mixed sublattices

Effects of V/III ratio on ordering and antiphase boundaries in GaInP layers

Journal ArticleTransmission electron microscope (TEM) and transmission electron diffraction (TED) studies have been performed to investigate the effects of V/III ratio on ordering and antiphase boundaries (APBs) in organometallic vapor phase epitaxial Ga0.5In0.5P layers grown onto (001) GaAs vicinal substrates at 670 °C. TED and TEM examination showed that the degree of order is higher in the layer grown using a V/III ratio of 160 than in the layer grown using a V/III ratio of 40. TEM results showed that the higher V/III ratio could be used to suppress APBs. In addition, the growth of order-induced heterostructures, where the V/III ratio is increased abruptly during growth, could be used to block the propagation of APBs. Mechanisms are proposed to explain these phenomena

Critical Exponents of the Four-State Potts Model

The critical exponents of the four-state Potts model are directly derived from the exact expressions for the latent heat, the spontaneous magnetization, and the correlation length at the transition temperature of the model.Comment: LaTex, 7 page

A_4 flavour symmetry breaking scheme for understanding quark and neutrino mixing angles

We propose a spontaneous A_4 flavour symmetry breaking scheme to understand the observed pattern of quark and neutrino mixing. The fermion mass eigenvalues are arbitrary, but the mixing angles are constrained in such a way that the overall patterns are explained while also leaving sufficient freedom to fit the detailed features of the observed values, including CP violating phases. The scheme realises the proposal of Low and Volkas to generate zero quark mixing and tribimaximal neutrino mixing at tree-level, with deviations from both arising from small corrections after spontaneous A_4 breaking. In the neutrino sector, the breaking is A_4 --> Z_2, while in the quark and charged-lepton sectors it is A_4 --> Z_3 = C_3. The full theory has A_4 completely broken, but the two different unbroken subgroups in the two sectors force the dominant mixing patterns to be as stated above. Radiative effects within each sector are shown to deviate neutrino mixing from tribimaximal, while maintaining zero quark mixing. Interactions between the two sectors -- "cross-talk" -- induce nonzero quark mixing, and additional deviation from tribimaximal neutrino mixing. We discuss the vacuum alignment challenge the scenario faces, and suggest three generic ways to approach the problem. We follow up one of those ways by sketching how an explicit model realising the symmetry breaking structure may be constructed.Comment: 14 pages, no figures; v3: Section 5 rewritten to correct an error; new section added to the appendix; added references; v4: minor change to appendix C, version to be published by JHE

Investigating the role of microtubules on pro-invasive factor secretion and intracellular organisation in cells with extra centrosomes

The presence of extra centrosomes can drive aneuploidy and invasiveness, thus contributing to tumorigenesis. We previously showed that cells with extra centrosomes induce extra centrosomes-associated secretory pathway (ECASP) that leads to pro-invasive factor secretion, such as IL-8, and drives paracrine invasion. The exact mechanism of how the presence of supernumerary centrosomes promotes ECASP is unclear, but it requires reactive oxygen species (ROS) generated by p22phox-dependent NADPH oxidases(s) (NOXs) and microtubules. Furthermore, we recently observed that cells with amplified centrosomes exhibit higher nuclear deformability and these cells are capable of migrating through small pores faster than cells with a normal number of centrosomes. Therefore, these phenotypes induced by centrosome amplification may facilitate the metastatic potential of cancer cells. In this work, I investigated the mechanism of how centrosome amplification drives these processes. I found that centrosome amplification increases microtubule modifications (PTMs), in particular acetylation. The increased levels of acetylated tubulin are known to enhance kinesin-1 motility and promote the periphery-directed trafficking of proteins, which may be important for secretion. Thus, I examined whether IL-8, one of the key pro-invasive factors, was affected by acetylated tubulin. When acetylated tubulin was depleted in cells with extra centrosomes, however, the secretion of IL-8 was not affected. This suggests that alternative mechanisms exist. Lastly, I examined alterations in the intracellular organisation that may promote nuclear deformation and allows extra centrosomes to migrate faster. Vimentin intermediate filament is known to act as a protective cage around the nucleus and resists nuclear deformation while migrating through small interstitial spaces. Strikingly, the vimentin intermediate filament, which is known to be transported by kinesin-1, was displaced away from the nucleus upon centrosome amplification induction. This implies that the loss of the vimentin cage around the nucleus may be responsible for increased nuclear deformation and allow cells to squeeze through small pores faster. Along with vimentin, extra centrosomes induced a global change in the intracellular organisation where various organelles: centrosomes, Golgi, mitochondria, and endosomes are displaced towards the cell periphery. Depletion of the acetylated tubulin prevented the displacement of vimentin intermediate filaments, centrosomes, and mitochondria. Conversely, increasing tubulin acetylation by H2O2 treatment was sufficient to drive the displacement of the same organelles. This work demonstrates that changes in the intracellular organisation, in particular vimentin intermediate filament, may promote the migratory speed of cells with amplified centrosomes

High-performance Si microwire photovoltaics

Crystalline Si wires, grown by the vapor–liquid–solid (VLS) process, have emerged as promising candidate materials for lowcost, thin-film photovoltaics. Here, we demonstrate VLS-grown Si microwires that have suitable electrical properties for high-performance photovoltaic applications, including long minority-carrier diffusion lengths (L_n » 30 µm) and low surface recombination velocities (S « 70 cm·s^(-1)). Single-wire radial p–n junction solar cells were fabricated with amorphous silicon and silicon nitride surface coatings, achieving up to 9.0% apparent photovoltaic efficiency, and exhibiting up to ~600 mV open-circuit voltage with over 80% fill factor. Projective single-wire measurements and optoelectronic simulations suggest that large-area Si wire-array solar cells have the potential to exceed 17% energy-conversion efficiency, offering a promising route toward cost-effective crystalline Si photovoltaics

Regulation of Apoptosis during Environmental Skin Tumor Initiation

Skin cancer is more prevalent than any other cancer in the United States. Nonmelanoma skin cancers are the more common forms of skin cancer that affect individuals. The development of squamous cell carcinoma, the second most common type of skin cancer, can be stimulated by exposure of environmental carcinogens, such as chemical toxicants or UVB. It is developed by three distinct stages: initiation, promotion, and progression. During the initiation, the fate of DNA-damaged skin cells is determined by the homeostatic regulation of pro-apoptotic and antiapoptotic signaling pathways. The imbalance or disruption of either signaling will lead to the survival of initiated cells, resulting in the development of skin cancer. In this chapter, we will discuss signaling pathways that regulate apoptosis and the impact of their dysfunction during skin tumor initiation

Regulation of Apoptosis during Environmental Skin Tumor Initiation

Skin cancer is more prevalent than any other cancer in the United States. Nonmelanoma skin cancers are the more common forms of skin cancer that affect individuals. The development of squamous cell carcinoma, the second most common type of skin cancer, can be stimulated by exposure of environmental carcinogens, such as chemical toxicants or UVB. It is developed by three distinct stages: initiation, promotion, and progression. During the initiation, the fate of DNA-damaged skin cells is determined by the homeostatic regulation of pro-apoptotic and antiapoptotic signaling pathways. The imbalance or disruption of either signaling will lead to the survival of initiated cells, resulting in the development of skin cancer. In this chapter, we will discuss signaling pathways that regulate apoptosis and the impact of their dysfunction during skin tumor initiation