3D-patterned inverse-designed mid-infrared metaoptics

Modern imaging systems can be enhanced in efficiency, compactness, and application through the introduction of multilayer nanopatterned structures for manipulation of light based on its fundamental properties. High transmission multispectral imaging is elusive due to the commonplace use of filter arrays which discard most of the incident light. Further, given the challenges of miniaturizing optical systems, most cameras do not leverage the wealth of information in polarization and spatial degrees of freedom. Optical metamaterials can respond to these electromagnetic properties but have been explored primarily in single-layer geometries, limiting their performance and multifunctional capacity. Here we use advanced two-photon lithography to realize multilayer scattering structures that achieve highly nontrivial optical transformations intended to process light just before it reaches a focal plane array. Computationally optimized multispectral and polarimetric sorting devices are fabricated with submicron feature sizes and experimentally validated in the mid-infrared. A final structure shown in simulation redirects light based on its angular momentum. These devices demonstrate that with precise 3-dimensional nanopatterning, one can directly modify the scattering properties of a sensor array to create advanced imaging systems.

Uptake of Pb and the Formation of Mixed (Ba,Pb)SO4 Monolayers on Barite During Cyclic Exposure to Lead-Containing Sulfuric Acid

Barite (BaSO₄) is a common additive in lead-acid batteries, where it acts as a nucleating agent to promote the reversible formation and dissolution of PbSO₄ during battery cycling. However, little is known about the molecular-scale mechanisms that control the nucleation and cyclic evolution of PbSO₄ over a battery's lifetime. In this study, we explore the responses of a barite (001) surface to cycles of high and low lead concentrations in 100 mM sulfuric acid solution using in situ atomic force microscopy and high-resolution X-ray reflectivity. We find that PbSO₄ epitaxial films readily nucleate on the barite surface, even from solutions that are undersaturated relative to bulk PbSO₄. Despite this, barite (001) proves to be an ineffective nucleator of bulk PbSO₄, as multilayer growth is suppressed even in highly supersaturated solutions. Instead, we find evidence that Pb²⁺ ions can directly exchange with Ba²⁺ to create mixed (Ba,Pb)SO₄ surfaces. These chemically mixed surfaces do not host PbSO₄ monolayers as readily as pristine barite, and the original reactivity is not regained until a fresh surface is re-established by aggressive etching. Our results can be partly explained by traditional models of thin-film growth, which predict a Stranski-Krastanov (S-K) growth mode, where monolayer films are stabilized by a reduction in surface energy, but multilayer growth is inhibited by epitaxial strain. Complementary density functional theory calculations confirm the basic energetic terms of the model but also show evidence for thickness-dependent energetics that are more complex than would be predicted from traditional models. The experimental results are better understood by extending the model to consider the formation of mixed surfaces and films, which have reduced strain and interfacial energies relative to pure films while also being stabilized by entropy of mixing. These insights into nonstoichiometric heteroepitaxy will enable better predictions of how barite affects PbSO₄ nucleation in battery environments.

Humidified rapid-insufflation ventilatory exchange is a means of oxygenation during rigid bronchoscopy: A case series

Humidified rapid-insufflation ventilatory exchange (HRIVE) is an option for maintenance of oxygenation. This technique allows for oxygenation while the patient is apnoeic due to continuous positive airway pressure and gas exchange through flow-dependent dead space flushing. There is no study about the usage of HRIVE during rigid bronchoscopy. This retrospective study looked at rigid bronchoscopy cases utilizing HRIVE. Data points assessing adequacy of oxygenation and ventilation were recorded at time points: oxygen saturation (SpO2), partial pressure of oxygen (PaO2) and partial pressure of carbon dioxide (PaCO2). Our nine cases had an average baseline SpO2 of 99.26%, 95.56% at 10 min into HRIVE and 95.27% at the end of HRIVE. The average baseline PaO2 was 309.01 mmHg, 124.99 mmHg at 10 min into HRIVE and 128.17 mmHg at the end of HRIVE. The average baseline PaCO2 was 43.26 mmHg, 68.76 mmHg at 10 min into HRIVE and 75.52 mmHg at the end of HRIVE. The average pre-HRIVE end-tidal CO2 (ETCO2) was 38.56 mmHg and the average post-HRIVE ETCO2 was 61.22 mmHg. The average baseline pH was 7.36, 7.22 at 10 min into HRIVE and 7.19 at the end of HRIVE. In this small cohort study, HRIVE was able to maintain adequate oxygenation via the rigid bronchoscope in a select group of patients. Hypercapnia and respiratory acidosis did result after 10 min, which may predispose certain patient populations to complications. HRIVE potentially offers an additional option of oxygenation via the rigid bronchoscope.

Dual-Salt Electrolytes to Effectively Reduce Impedance Rise of High-Nickel Lithium-Ion Batteries

Simply mixing several lithium salts in one electrolyte to obtain blended salt electrolytes has been demonstrated as a promising strategy to formulate advanced electrolytes for lithium metal batteries (LMBs) and lithium-ion batteries (LIBs). In this study, we report the use of dual-salt electrolytes containing lithium hexafluorophosphate (LiPF₆) and lithium difluorophosphate (LiDFP) in ethylene carbonate/ethyl methyl carbonate (EC/EMC) mixture and tested them in layered high-nickel LIB cells. LiNi_0.94Co_0.06O₂ was synthesized through a coprecipitation method and was used as a representative high-nickel cathode for the U.S. DOE realizing next-generation cathode (RNGC) deep dive program. The ionic conductivity of dual-salt electrolytes can be maintained by controlling the amount of LiDFP. Techniques including ¹H Nuclear Magnetic Resonance (NMR), X-ray photoelectron spectroscopy (XPS), inductively coupled plasma-mass spectrometry (ICP-MS), and differential voltage analysis (DVA) were used to understand the improved performance. The multifaceted benefits of using the dual-salt electrolytes include (1) reduced transesterification, (2) formation of a stable cathode electrolyte interface, and (3) mitigation of cathode degradation at high voltages, especially stabilization of oxide particles during the H2 ↔ H3 transformation.

Clinical Outcome of Kidney Transplant Patients on the Allograft Function, Loss, Effects of HLA-DQB1-DSA+, and Graft Survival

INTRODUCTION

Matching for HLA-DQB1 molecules and anti-DQ donor-specific antibodies (DSAs) has been less studied to allocate transplants from deceased donors in developed countries. The aim of this study was to evaluate the clinical outcome of 519 kidney transplant recipients on the allograft function, loss, and survival and with emphasis on effects of HLA-DQB1-DSA⁺ at minimum of 10 years' follow-up.

METHODS

Five hundred nineteen kidney transplant patients were allocated into 3 groups (G) by immunologic profiles, namely, G1 (SPI-SAB HLA-DQ negative [DQ^-]), G2 (SPI-SAB HLA-DQ positive DSA negative [DQ⁺/DSA^-]), and G3 (SPI-SAB HLA-DQ DSA positive [DQ⁺ DSA⁺]), and the outcomes were reported until 10 years after transplantation.

RESULTS

The proportion of rejection episodes was higher in G3 (25.0% and 26.32%, respectively) than in G1 (8.63% and 6.82%, respectively) and G2 (10.0% and 0%, respectively; P = .047 and P = .014, respectively). In G3, 3 patients lost their grafts by antibody-mediated rejection. Patients who received kidneys from deceased donors (G3) showed worse graft survival rates than those from G1 donors (P = .001). Patients from G3 had a 2.18-fold higher risk of graft loss than patients from G1 (P = .028).

CONCLUSION

Allograft function was worse in G3 than in G2 or G1, and graft losses were more frequent by T-cell-mediated rejection in G1, and graft losses by antibody-mediated rejection were similar in G1 and G3 due to HLA class I (A1, 11 and B 8, 52) and HLA class II by DR7 and DQ 2, 5, 9 DSA, respectively. Allograft survival decreased in patients with HLA-DQB1 DSA. The risk of graft loss was 1.75-fold that in patients who received transplants from living donors.

Imaging from the visible to the longwave infrared wavelengths via an inverse-designed flat lens

It is generally assumed that correcting chromatic aberrations in imaging requires multiple optical elements. Here, we show that by allowing the phase in the image plane to be a free parameter, it is possible to correct chromatic variation of focal length over an extremely large bandwidth, from the visible (Vis) to the longwave infrared (LWIR) wavelengths using a single diffractive surface, i.e., a flat lens. Specifically, we designed, fabricated and characterized a flat, multi-level diffractive lens (MDL) with a thickness of ≤ 10µm, diameter of ∼1mm, and focal length of 18mm, which was constant over the operating bandwidth of λ=0.45µm (blue) to 15µm (LWIR). We experimentally characterized the point-spread functions, aberrations and imaging performance of cameras comprised of this MDL and appropriate image sensors for λ=0.45μm to 11μm. We further show using simulations that such extreme achromatic MDLs can be achieved even at high numerical apertures (NA=0.81). By drastically increasing the operating bandwidth and eliminating several refractive lenses, our approach enables thinner, lighter and simpler imaging systems.

Quantification of BERT Diagnosis Generalizability Across Medical Specialties Using Semantic Dataset Distance

Deep learning models in healthcare may fail to generalize on data from unseen corpora. Additionally, no quantitative metric exists to tell how existing models will perform on new data. Previous studies demonstrated that NLP models of medical notes generalize variably between institutions, but ignored other levels of healthcare organization. We measured SciBERT diagnosis sentiment classifier generalizability between medical specialties using EHR sentences from MIMIC-III. Models trained on one specialty performed better on internal test sets than mixed or external test sets (mean AUCs 0.92, 0.87, and 0.83, respectively; p = 0.016). When models are trained on more specialties, they have better test performances (p < 1e-4). Model performance on new corpora is directly correlated to the similarity between train and test sentence content (p < 1e-4). Future studies should assess additional axes of generalization to ensure deep learning models fulfil their intended purpose across institutions, specialties, and practices.

Strain-driven surface reconstruction and cation segregation in layered Li(Ni1-x-yMnxCoy)O2 (NMC) cathode materials

The composition, structure and phase transformations occurring on cathode surfaces greatly affect the performance of Li-ion batteries. Li-Ion diffusion and surface-electrolyte interaction are two major phenomena that impact the capacity and cell impedance. The effects of surface reconstruction (SR) of cathode materials on the performance of Li-ion batteries are of current interest. However, the origin and evolution of the SR are still not well understood. In this work, density functional theory (DFT) calculations are used to investigate the processes taking place during surface segregation and reconstruction. Facet dependent segregation was found in Li(Ni_1-x-yMn_xCo_y)O₂ (NMC) cathodes. Specifically, Co tends to segregate to the (104) surface of the primary particles within the transition metal layer, while Ni ions tend to segregate to the (012) surface in the Li layer, forming a SR. Experimental evidence shows the SR to be epitaxial with the bulk of the as-synthesized material, and the new SR phase is pinned to the NMC unit cell leading to a strained SR. Here, we show that strain can stabilize a spinel structure of the SR layers. Understanding the effects of surface strain opens a new avenue for the design of cathode materials with enhanced surface properties.

RARβ acts as both an upstream regulator and downstream effector of miR-22, which epigenetically regulates NUR77 to induce apoptosis of colon cancer cells

This study investigates the mechanism and consequences of microRNA-22 ( miR-22) induction. Our data revealed for the first time that retinoic acid (RA) and histone deacetylase (HDAC) inhibitors, including short-chain fatty acids and suberanilohydroxamic acid (SAHA), could individually or in combination induce miR-22. This induction was mediated via RA receptor β (RARβ) binding to a direct repeat 5 (DR5) motif. In addition, we uncovered HDAC1 as a novel miR-22 target. In an miR-22-dependent manner, HDAC inhibitors and RA reduced HDAC1, HDAC4, and sirtuin 1 (SIRT1), which were involved in chromatin remodeling of the RARβ and nerve growth factor IB ( NUR77). Thus, HDAC inhibitors and RA-induced miR-22 resulted in simultaneous induction of cytoplasmic RARβ and NUR77, leading to apoptosis of colon cancer cells. In mice, miR-22 and its inducers inhibited the growth of xenograft colon cancer. Moreover, tumor size reduction was accompanied by elevated miR-22, NUR77, and RARβ and by reduced HDACs. In human colon polyps and adenocarcinomas, miR-22 and RARβ were consistently reduced, which was associated with elevated HDAC1, HDAC4, and SIRT1 in colon adenocarcinomas. Results from this study revealed a novel anticancer mechanism of RARβ via miR-22 induction to epigenetically regulate itself and NUR77, providing a promising cancer treatment modality using miR-22 and its inducers.-Hu, Y., French, S. W., Chau, T., Liu, H.-X., Sheng, L., Wei, F., Stondell, J., Garcia, J. C., Du, Y., Bowlus, C. L., Wan, Y.-J. Y. RARβ acts as both an upstream regulator and downstream effector of miR-22, which epigenetically regulates NUR77 to induce apoptosis of colon cancer cells.

From Coating to Dopant: How the Transition Metal Composition Affects Alumina Coatings on Ni-Rich Cathodes

Surface alumina coatings have been shown to be an effective way to improve the stability and cyclability of cathode materials. However, a detailed understanding of the relationship between the surface coatings and the bulk layered oxides is needed to better define the critical cathode-electrolyte interface. In this paper, we systematically studied the effect of the composition of Ni-rich LiNi_xMn_yCo_1-x-yO₂ (NMC) on the surface alumina coatings. Changing cathode composition from LiNi_0.5Mn_0.3Co_0.2O₂ (NMC532) to LiNi_0.6Mn_0.2Co_0.2O₂ (NMC622) and LiNi_0.8Mn_0.1Co_0.1O₂ (NMC811) was found to facilitate the diffusion of surface alumina into the bulk after high-temperature annealing. By use of a variety of spectroscopic techniques, Al was seen to have a high bulk compatibility with higher Ni/Co content, and low bulk compatibility was associated with Mn in the transition metal layer. It was also noted that the cathode composition affected the observed morphology and surface chemistry of the coated material, which has an effect on electrochemical cycling. The presence of a high surface Li concentration and strong alumina diffusion into the bulk led to a smoother surface coating on NMC811 with no excess alumina aggregated on the surface. Structural characterization of pristine NMC particles also suggests surface Co segregation, which may act to mediate the diffusion of the Al from the surface to the bulk. The diffusion of Al into the bulk was found to be detrimental to the protection function of surface coatings leading to poor overall cyclability, indicating the importance of compatibility between surface coatings and bulk oxides on the electrochemical performance of coated cathode materials. These results are important in developing a better coating method for synthesis of next-generation cathode materials for lithium-ion batteries.

Experimental Demonstration of >230° Phase Modulation in Gate-Tunable Graphene-Gold Reconfigurable Mid-Infrared Metasurfaces

Metasurfaces offer significant potential to control far-field light propagation through the engineering of the amplitude, polarization, and phase at an interface. We report here the phase modulation of an electronically reconfigurable metasurface and demonstrate its utility for mid-infrared beam steering. Using a gate-tunable graphene-gold resonator geometry, we demonstrate highly tunable reflected phase at multiple wavelengths and show up to 237° phase modulation range at an operating wavelength of 8.50 μm. We observe a smooth monotonic modulation of phase with applied voltage from 0° to 206° at a wavelength of 8.70 μm. Based on these experimental data, we demonstrate with antenna array calculations an average beam steering efficiency of 23% for reflected light for angles up to 30° for this range of phases, confirming the suitability of this geometry for reconfigurable mid-infrared beam steering devices. By incorporating all nonidealities of the device into the antenna array calculations including absorption losses which could be mitigated, 1% absolute efficiency is achievable up to 30°.

A Natural Interface for Remote Operation of Underwater Robots

Human-machine interfaces play a crucial role in intervention robotic systems operated in hazardous environments, such as deep sea conditions. This article introduces a user interface abstraction layer to enhance reconfigurability. It also describes a VR-based interface that utilizes immersive technologies to reduce user faults and mental fatigue. The goal is to show the user only the most relevant information about the current mission.

Feasibility of an endoscopic approach to the axillary nerve and the nerve to the long head of the triceps brachii with the help of the Da Vinci Robot

Surgery to transfer the axillary nerve and the nerve of the long head of the triceps presents two obstacles: 1) the access portals are not standardized and 2) the nerves are for their larger part approached through large incisions. The goal of this study was to explore the feasibility of an endoscopic microsurgical approach. The posterior aspect of a cadaver shoulder was approached through three communicating mini-incisions. The Da Vinci robot camera was installed on a central trocart, and the instrument arms on the adjacent trocarts. A gas insufflation distended the soft tissues up to the lateral axillary space. The branches of the axillary nerve and the nerve to the long head of the triceps brachii muscle were identified. The dissection of the axillary nerve trunk and its branches was easy. The posterior humeral circumflex veins and artery were dissected as well without any difficulty. Finding the nerve to the long head of the triceps brachii was found to be more challenging because of its deeper location. Robots properties allow performing conventional microsurgery: elimination of the physiologic tremor and multiplication of the movements. They also facilitate the endoscopic approach of the peripheral nerves, as seen in our results on the terminal branches of the axillary nerve and the nerve to the long head of the triceps brachii.

Identification and virulence of Chryseobacterium indologenes isolated from diseased yellow perch (Perca flavescens)

AIM

To identify pathogen of diseased yellow perch and determine their virulence.

METHODS AND RESULTS

Fifteen Gram-negative bacterial isolates were recovered from the skin lesions of diseased yellow perch (Perca flavescens). Based on API 20NE test, ten isolates were found to share 67.2-99.9% homologies with Chryseobactertium indologenes. Based on fatty acid methyl ester analysis, 13 isolates were found to share similarities with C. indologenes and other species of Chryseobacterium. Based on sequencing results of partial 16S rRNA gene, 13 isolates shared 99% identities (e value = 2e-50) with the 16S rRNA sequence of C. indologenes (GenBank HQ259684). Based on the 16S-23S rRNA intergenic spacer region (ISR) sequence, the 13 isolates shared 88% identity (e value = 1e-165) with the 16S-23S ISR sequence of C. indologenes (GenBank EU014570). T-coffee multiple sequence alignment revealed that the partial 16S rRNA or the 16S-23S ISR sequence of the 13 isolates shared 100% identity with each other. When healthy yellow perch were exposed to the 15 isolates by bath immersion (c. 6 × 10(7) CFU ml(-1) for 1 h), only C. indologenes isolates killed 10-20% of fish, whereas other isolates were avirulent. When yellow perch were exposed to C. indologenes by intraperitoneal injection, mortality was dose dependent, with LD(50) and LD(95) values of 1.5 × 10(8) and 3.2 × 10(8) CFU per fish, respectively.

CONCLUSIONS

Chryseobactertium indologenes could be pathogenic to yellow perch.

SIGNIFICANCE AND IMPACT OF THE STUDY

This is the first report on the isolation of C. indologenes from diseased yellow perch. Virulence studies suggested that C. indologenes could become pathogenic to yellow perch.

A sensitive crude oil bioassay indicates that oil spills potentially induce a change of major nitrifying prokaryotes from the archaea to the bacteria

The sensitivity of nitrifiers to crude oil released by the BP Deepwater Horizon oil spill in Gulf of Mexico was examined using characterized ammonia-oxidizing bacteria and archaea to develop a bioassay and to gain further insight into the ecological response of these two groups of microorganisms to marine oil spills. Inhibition of nitrite production was observed among all the tested ammonia-oxidizing organisms at 100 ppb crude oil. Nitrosopumilus maritimus, a cultured representative of the abundant Marine Group I Archaea, showed 20% inhibition at 1 ppb, a much greater degree of sensitivity to petroleum than the tested ammonia-oxidizing and heterotrophic bacteria. The differing susceptibility may have ecological significance since a shift to bacterial dominance in response to an oil spill could potentially persist and alter trophic interactions influenced by availability of different nitrogen species.

Crystal engineering using functionalized adamantane

We performed a first-principles investigation on the structural, electronic and optical properties of crystals made of chemically functionalized adamantane molecules. Several molecular building blocks, formed by boron and nitrogen substitutional functionalizations, were considered to build zinc blende and wurtzite crystals, and the resulting structures presented large bulk moduli and cohesive energies, wide and direct bandgaps, and low dielectric constants (low-κ materials). Those properties provide stability for such structures up to room temperature, superior to those of typical molecular crystals. This indicates a possible road map for crystal engineering using functionalized diamondoids, with potential applications ranging from space filling between conducting wires in nanodevices to nano-electromechanical systems.

Effect of gonadotropin treatment on estrus, ovulation, and litter size in weaned and anestrous sows

In the first of 2 experiments, we evaluated the effects on anestrous sows of pretreatment with FSH to stimulate the growth of small follicles, followed by eCG to stimulate the growth of medium follicles, estrus, and ovulation. In Exp. 2, we examined the effect of sows receiving 400 IU of eCG plus 200 IU of hCG (PG 600, Intervet/Schering Plough Animal Health, Boxmeer, the Netherlands) at weaning and then different doses and timing of supplemental hCG. In Exp. 1, a total of 87 multiparous Hypor sows deemed anestrus 7 d after weaning were assigned to intramuscular (i.m.) injection of 1) PG 600, 2) eCG (600 IU), 3) pretreatment with 87.5 IU of FSH on d 7 and 8 plus eCG on d 9, or were 4) noninjected controls. Sows had daily boar contact for 15 d after weaning for estrus detection. Blood samples were obtained on d 9 and 19 and assayed for progesterone to determine ovulation status. The weaning-to-estrus interval, number of sows in estrus and ovulating, farrowing rate, and litter size were not different (P > 0.1) in treated groups compared with controls. In Exp. 2, a total of 247 Hypor sows were assigned at weaning by parity (1 and 2 or > or = 3) to receive 1) an i.m. injection of PG 600, 2) PG 600 supplemented with 100 IU of hCG injected either concurrently or after 24 h, 3) 200 IU of hCG after 24 h, or 4) no injection (controls). Sows were exposed to boars daily for 7 d. After treatment of parity 1 and 2 sows, all gonadotropin-treated groups had an increased (P < 0.05) number of sows in estrus compared with the control group; weaning-to-estrus interval, farrowing rates, and litter size were unaffected (P > 0.1). After treatment of parity > or = 3 sows, there was no treatment effect on the estrous response and weaning-to-estrus interval; compared with control and PG 600-treated sows, farrowing rate was decreased (P < 0.05) for sows receiving 200 IU of hCG after 24 h. There was no effect (P > 0.1) of treatment on litter size. We conclude that gonadotropins can be used to increase estrus response in weaned sows, but that hCG treatment subsequent to PG 600 may be detrimental to sow fertility in parity > or = 3 sows.

Thawing boar semen in the presence of seminal plasma: Effects on sperm quality and fertility

Causes of poor fertility after insemination of frozen-thawed (FT) sperm include reduced sperm viability at thawing and a shorter longevity of surviving sperm in the female genital tract due to sub-lethal damage. The present studies examined the effect of incubating thawed boar sperm in seminal plasma (SP) on sperm membrane integrity (viability), and motility in vitro (experiment 1), and fertility in vivo (experiment 2). For experiment 1, FT sperm from five individual boars and a sperm pool from these boars were thawed and incubated for 4 h in media containing 0%, 10%, or 50% autologous seminal plasma (individual boars) or pooled seminal plasma (sperm pool). At approximately 10 min (0 h) and again at 1 h, 2 h, 3 h, and 4 h, sperm populations were examined for percentage sperm viability and percent sperm motility. Each variable progressively decreased during the incubation period. Incubation in 50% SP increased percentages of live sperm (P < 0.0001) and percent sperm motility (P < 0.01) at all time points compared to incubation in either 0% or 10% SP. For experiment 2, multiparous Large white x Landrace sows (n = 82) each received 900 IU eCG at weaning and 750 IU hCG 80 h later to control time of ovulation. Sows were assigned on the basis of parity to be inseminated with pooled semen with or without SP from the boars used in experiment 1. Sows received 3 x 10(9) live fresh-extended sperm (n = 30) or FT sperm thawed in 80 mL BTS extender (n = 26) or 3 x 10(9) live FT sperm thawed in 80 mL BTS containing 50% SP (FT-SP; n = 26). Sows were inseminated at 36 h, and 42 h after hCG injection. Compared to sows receiving fresh semen, the pregnancy rate of FT inseminated sows tended (P = 0.06) to be lower with the FT-SP group being intermediate. Farrowing rates were not different (83.3%, 69.2%, and 65.4% for fresh, FT, and FT-SP, respectively). Inseminations with FT sperm were associated with a reduction in litter size (P < 0.05), which was not evident in the FT-SP group. Taken together, these data confirm an adverse effect of inseminating FT sperm on sperm quality and sow fertility but suggest that thawing FT sperm in 50% SP may partially alleviate these adverse effects.

Magnitude and complexity of rectal mucosa HIV-1-specific CD8+ T-cell responses during chronic infection reflect clinical status

Background

The intestinal mucosa displays robust virus replication and pronounced CD4+ T-cell loss during acute human immunodeficiency virus type 1 (HIV-1) infection. The ability of HIV-specific CD8+ T-cells to modulate disease course has prompted intensive study, yet the significance of virus-specific CD8+ T-cells in mucosal sites remains unclear.

Methods and Findings

We evaluated five distinct effector functions of HIVgag-specific CD8+ T-cells in rectal mucosa and blood, individually and in combination, in relationship to clinical status and antiretroviral therapy (ART). In subjects not on ART, the percentage of rectal Gag-specific CD8+ T-cells capable of 3, 4 or 5 simultaneous effector functions was significantly related to blood CD4 count and inversely related to plasma viral load (PVL) (p<0.05). Polyfunctional rectal CD8+ T-cells expressed higher levels of MIP-1β and CD107a on a per cell basis than mono- or bifunctional cells. The production of TNFα, IFN-γ, and CD107a by Gag-specific rectal CD8+ T-cells each correlated inversely (p<0.05) with PVL, and MIP-1β expression revealed a similar trend. CD107a and IFN-γ production were positively related to blood CD4 count (p<0.05), with MIP-1β showing a similar trend. IL-2 production by rectal CD8+ T-cells was highly variable and generally low, and showed no relationship to viral load or blood CD4 count.

Conclusions

The polyfunctionality of rectal Gag-specific CD8+ T-cells appears to be related to blood CD4 count and inversely related to PVL. The extent to which these associations reflect causality remains to be determined; nevertheless, our data suggest a potentially important role for mucosal T-cells in limiting virus replication during chronic infection.

Effect of insemination-ovulation interval and addition of seminal plasma on sow fertility to insemination of cryopreserved sperm

In swine, the use of frozen-thawed (FT) sperm for artificial insemination (AI) is limited because of poor sow fertility, possibly associated with a post-thaw capacitation-like status resulting in fewer fully viable sperm. Sow fertility to AI with FT sperm may improve with deeper deposition of sperm within the female tract, insemination very close to ovulation, or reversal of cryocapacitation by seminal plasma (SP). We performed two experiments to examine these suggestions. In experiment 1, 122 multiparous Yorkshire sows received 600 IU equine chorionic gonadotrophin at weaning and 5 mg pLH 80 h later to control time of ovulation. The predicted time of ovulation (PTO) was 38 h after pLH injection. Thereafter, sows were assigned on the basis of parity to a single AI of FT sperm at 2 h before PTO, or at 12 h before PTO, or FT sperm supplemented with 10% SP at 12 h before PTO. Control sows received fresh semen at 12 h before PTO. All semen doses were adjusted to 3 x 10(9) live cells and deposited into the cervix. Experiment 2 employed 99 multiparous crossbred sows and repeated the treatments of experiment 1 except that all FT inseminations were intrauterine. In both experiments, farrowing rates were lower (p < 0.01) following FT inseminations with no effect of time of insemination or of supplemental SP. In experiment 1, litter size was smaller following FT insemination (p < 0.05), but no effect on litter size was evident in experiment 2. Supplemental SP had no effect on litter size in either experiment. The lack of effect of either SP or timing of FT insemination on sow fertility suggests that the non-lethal sperm cryoinjury affecting fertility involves more than just cryocapacitation.

Comparative study of the degradation of real textile effluents by photocatalytic reactions involving UV/TiO2/H2O2 and UV/Fe2+/H2O2 systems

This work investigated the treatability of real textile effluents using several systems involving advanced oxidation processes (AOPs) such as UV/H2O2, UV/TiO2, UV/TiO2/H2O2, and UV/Fe2+/H2O2. The efficiency of each technique was evaluated according to the reduction levels observed in the UV absorbance of the effluents, COD, and organic nitrogen reduction, as well as mineralization as indicated by the formation of ammonium, nitrate, and sulfate ions. The results indicate the association of TiO2 and H2O2 as the most efficient treatment for removing organic pollutants from textile effluents. In spite of their efficiency, Fenton reactions based treatment proved to be slower and exhibited more complicated kinetics than the ones using TiO2, which are pseudo-first-order reactions. Decolorization was fast and effective in all the experiments despite the fact that only H2O2 was used.

Effect of sperm numbers and time of insemination relative to ovulation on sow fertility

We examined the effect of inseminating mixed parity sows (n=231) once with fewer sperm at different times relative to ovulation. Lactation length was 19 days and sows received an IM injection of 600 IU equine chorionic gonadotrophin (eCG) 12 h before weaning. At 80 h after eCG injection, sows received an IM injection of 5 mg porcine luteinizing hormone (pLH). Predicted time of ovulation (PTO) was 38 h after pLH injection. Sows were assigned by parity to receive a single transcervical artificial insemination (AI) at either 6 or 24 h before PTO with semen doses containing either 2.5 or 1.25x10(9) sperm. A positive control group of sows (n=49) was subject to conventional AI 24 and 6 h before PTO. Detection of estrus was performed in the presence of a boar and only sows exhibiting estrous behavior at the assigned time of AI were included in the study. Farrowing rate for sows receiving 2.5x10(9) sperm at 6 h before PTO was greater than that for sows receiving 1.25x10(9) sperm at 24 h before PTO (85% versus 61%, P<0.05). All other groups were intermediate. There was no effect of time of AI or sperm numbers on subsequent litter size. These data indicate that single insemination of fewer sperm may compromise sow fertility, even when performed transcervically, if not appropriately timed relative to ovulation.

Multifunctional human immunodeficiency virus (HIV) gag-specific CD8+ T-cell responses in rectal mucosa and peripheral blood mononuclear cells during chronic HIV type 1 infection

The intestinal tract is a lymphocyte-rich site that undergoes severe depletion of memory CD4(+) T cells within days of simian immunodeficiency virus or human immunodeficiency virus type 1 (HIV-1) infection. An ensuing influx of virus-specific CD8(+) T cells, which persist throughout the chronic phase of infection, has also been documented in the gastrointestinal tract. However, little is known of the functionality of these effector cells or their relationship to the disease course. In this study, we measured CD8(+) T-cell responses to HIV-1 peptides in paired rectal and blood samples from chronically infected patients. In both blood and rectum, there was an immunodominant CD8(+) T-cell response to HIV Gag compared to Pol and Env (P < 0.01). In contrast, cytomegalovirus pp65 peptides elicited gamma interferon (IFN-gamma) secretion strongly in peripheral blood mononuclear cells (PBMC) but weakly in rectal CD8(+) T cells (P = 0.015). Upon stimulation with HIV peptides, CD8(+) T cells from both sites were capable of mounting complex responses including degranulation (CD107 expression) and IFN-gamma and tumor necrosis factor alpha (TNF-alpha) production. In rectal tissue, CD107 release was frequently coupled with production of IFN-gamma or TNF-alpha. In patients not on antiretroviral therapy, the magnitude of Gag-specific responses, as a percentage of CD8(+) T cells, was greater in the rectal mucosa than in PBMC (P = 0.054); however, the breakdown of responding cells into specific functional categories was similar in both sites. These findings demonstrate that rectal CD8(+) T cells are capable of robust and varied HIV-1-specific responses and therefore likely play an active role in eliminating infected cells during chronic infection.

Autologous stem-cell transplantation in diffuse large B-cell non-Hodgkin's lymphoma not achieving complete response after induction chemotherapy: the GEL/TAMO experience

BACKGROUND

Here we evaluate the results of high-dose chemotherapy and autologous stem-cell transplantation (HDC/ASCT) in 114 patients included in the GEL/TAMO registry between January 1990 and December 1999 with diffuse large B-cell lymphoma who failed to achieve complete remission (CR) with front-line conventional chemotherapy.

PATIENTS AND METHODS

Sixty-eight per cent had a partial response (PR) and 32% failed to respond to front-line therapy. At transplant, 35% were chemoresistant and 29% had two to three adjusted International Prognostic Index (a-IPI) risk factors.

RESULTS

After HDC/ASCT, 57 (54%) of 105 patients evaluable for response achieved a CR, 16 (15%) a PR and 32 (30%) failed. Nine patients were not assessed for response because of early death due to toxicity. With a median follow-up of 29 months for alive patients, the survival at 5 years is 43%, with a disease-free survival for complete responders of 63%. The lethal toxicity was 8%. Multivariate analysis revealed a-IPI and chemoresistance to be predicting factors.

CONCLUSIONS

Our results show that one-third of patients who do not obtain a CR to front-line chemotherapy may be cured of their disease with HDC/ASCT. However, most chemoresistant patients pretransplant failed this therapy. For this population, as well as for those who presented with adverse factors of the a-IPI, pretransplant novel therapeutic modalities need to be tested.

Clinical evaluation of SyvekPatch in patients undergoing interventional, EPS and diagnostic cardiac catheterization procedures

BACKGROUND

The SyvekPatch (Marine Polymer Technologies, Danvers, Massachusetts) has received Food and Drug Association market clearance for the rapid control of bleeding from vascular access sites and percutaneous catheters. A clinical evaluation was designed to determine the efficacy and safety of this vascular closure device in 1,000 consecutive patients after routine diagnostic and interventional procedures.

METHODS

During a 3-month period, a total of 364 interventional patients (stenting, 55%; PTCA, 30%; EPS, 15%) and 636 diagnostic patients (left heart catheterization, 77%; right/left heart catheterization, 23%) were treated. Catheter sheaths ranged in size from 4 12 French (Fr). Antiplatelet therapy was employed in 35% of the interventional procedures. In approximately 20% of the cases, same-side repuncture occurred within 2 3 days.

RESULTS

The use of the SyvekPatch on a total of 1,000 consecutive patients resulted in the rapid control of bleeding with only 1 major complication (0.1%; pseudoaneurysm) and few minor complications (1.3%). The pseudoaneurysm was most likely caused by the aberrant location of the sheath. All minor complications were either small hematomas (< 2.5 cm; rate, 0.75%) or slight oozing from the puncture site (rate, 0.6%). Outcomes measured included clinical effectiveness, ability to maintain the femoral access site for future interventions, major complication rates (access-site related hematoma that required blood transfusion or an extended hospital stay, pseudoaneurysm, arteriovenous fistula, arterial or venous thrombosis, and infection), patient comfort and operational efficiency.

CONCLUSION

The strong safety and efficacy profile of the SyvekPatch has made a significant impact in our cardiac catheterization lab. Unlike existing vascular closure devices, the SyvekPatch was used following a diagnostic procedure even when a future interventional procedure was scheduled. The effectiveness of the SyvekPatch was not altered by anticoagulation or antiplatelet therapy. The patients and clinical staff were extremely satisfied with the use of the SyvekPatch .

Abscesses in Crohn's disease: outcome of medical versus surgical treatment

GOALS

To compare the long-term outcome of medical, percutaneous, and surgical treatment of abdominal and pelvic abscesses complicating Crohn's disease.

STUDY

All patients with Crohn's disease and an abdominal abscess treated at one institution during a 10-year period were retrospectively identified. We reviewed hospital and outpatient records and contacted patients for telephone interviews. Outcome measures included abscess recurrence, subsequent surgery for Crohn's disease, and medications used at the time of most recent follow-up.

RESULTS

Fifty-one subjects were identified, with a mean follow-up of 3.75 years. Fewer patients developed recurrent abscesses after initial surgical drainage and bowel resection (12%) than patients treated with medical therapy only or percutaneous drainage (56%) (p = 0.016). One half of the patients treated nonoperatively ultimately required surgery, whereas only 12% of those treated with initial surgery required reoperation during the follow-up period (p = 0.010). Most failures of nonoperative therapy occurred within 3 months. Medication use was similar between the treatment groups at the time of most recent follow-up.

CONCLUSIONS

In this series, surgical management of abscesses in Crohn's disease was more effective than medical treatment or percutaneous drainage for prevention of abscess recurrence. However, nonoperative therapy prevented subsequent surgery in half of the patients and may be a reasonable treatment option for some patients.

Antioxidant properties of alpha-crystallin

alpha-Crystallin is a major chaperone lens protein to which has been ascribed antioxidant functions. In the present work we have evaluated the antioxidant and free radical scavenging properties of bovine alpha-crystallin in a series of in vitro models: zimosan-induced, luminol-enhanced chemiluminescence response of polymorphonuclear leukocytes, the autoxidation of brain homogenate, bleaching of 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid)-derived radical cations, trapping of peroxyl radicals, and reactivity toward hypochloric acid. In all these systems, the reactivity of alpha-crystallin is higher than or similar to that of bovine serum albumin. It is concluded that, given the high concentrations of ol-crystallin in the lenses, its capacity to interact with free radicals and to remove hypochlorous acid could contribute to the maintenance of the lens functionality.

Phase II trial of uracil/tegafur (UFT) plus leucovorin in patients with advanced hepatocellular carcinoma

Although UFT 300 mg/m2/day and leucovorin 90 mg/day administered orally in divided doses administered every 8 hours for 28 days repeated every 35 days could be administered safely to patients with advanced hepatomas and good performance status, this combination and schedule has limited activity in treating advanced hepatoma.

BACKGROUND/PURPOSE

Biochemical modulation of 5-fluorouracil has yielded higher response rates in hepatoma when compared to treatment with 5-fluorouracil as a single agent, although the impact on survival has been negligible. This study was conducted to determine the activity and evaluate the toxicity of uracil and tegafur in a 4:1 molar concentration ratio (UFT; Bristol-Myers Squibb, Wallingford, CT) plus oral calcium leucovorin in the treatment of patients with advanced hepatocellular carcinoma (hepatoma).

PATIENTS AND METHODS

Sixteen patients with advanced measurable hepatocellular carcinoma were enrolled onto the trial. All patients had a Karnofski performance status > or = 60%, platelet count > or = 75,000/micro L, total bilirubin < or = 2.0 x institutional upper limit of normal but otherwise normal liver and kidney function profile and bidimensionally measurable disease by CT or ultrasound examination. None of these patients received prior cytotoxic chemotherapy or radiation therapy for advanced disease. Fourteen patients received 300 mg/m2/d UFT plus 90 mg/d leucovorin administered orally in divided daily doses every 8 hours for 28 days repeated every 35 days. Two patients registered for the trial but did not receive study medication. Objective tumor response, the primary purpose of this trial, was evaluated after two courses of therapy. Other end-points included toxicity, time to progression, and overall survival.

RESULTS

Fourteen patients were evaluable for response and toxicity, respectively. No complete or partial responders were observed in this trial. Three patients had stable disease lasting 17 to 22 weeks. Toxicity was mild with severe (grade 3 or 4) liver pain, diarrhea, anorexia/nausea, fatigue, dyspnea, hyperbilirubinemia, anemia, and edema seen in 3 (21%), 2 (14%), 3 (21%), 2 (14%), 1 (7%), 1 (7%), 1 (7%) and 1 (7%) patients, respectively. The most frequent grade I and 2 toxic effects included fever of unknown origin, dyspnea, nausea, vomiting and diarrhea.

CONCLUSION

UFT 300 mg/m2/d plus oral leucovorin 90 mg/d administered for 28 days did not demonstrate antitumor activity against advanced hepatomas. Further treatment using this regimen is not recommended for this disease.

Phase II trial of 150-minute weekly infusion of gemcitabine in advanced colorectal cancer: minimal activity in colorectal cancer

Metastatic colorectal cancer is very common in the Western hemisphere and current treatment modalities are not effective. In this study a prolonged (150-minute) infusion of gemcitabine at a constant dose rate of 10 mg/m2/min administered weekly for 3 consecutive weeks repeated every 4 weeks revealed a response rate of 4% (90% CI < 1%-18%). There were no complete responses. Treatment with gemcitabine produced moderate to severe toxicity as grade 3-4 neutropenia requiring dose modification was seen in 40% of patients treated. When used in this dose and schedule, gemcitabine does not appear to be effective for patients with metastatic colorectal cancer.

Phase II trial of uracil/tegafur (UFT) plus leucovorin in patients with advanced pancreatic carcinoma: a University of Chicago phase II consortium study

BACKGROUND/OBJECTIVES

Uracil and tegafur in a 4:1 molar concentration ratio (UFT; Bristol-Myers Squibb, Wallingford, CT) has broad anti-tumor activity for cancers arising from the gastrointestinal tract. However, there are no published data regarding the efficacy of leucovorin-modulated UFT in patients with pancreatic cancer. The objective of this trial was to determine the activity and evaluate the toxicity of UFT plus oral calcium leucovorin in patients with advanced pancreatic adenocarcinoma.

PATIENTS AND METHODS

Fourteen patients with advanced measurable adenocarcinoma of the pancreas were enrolled onto the trial. Patients received 300 mg/m2/d UFT plus 90 mg/d leucovorin administered orally in divided doses every eight hours for 28 days repeated every 35 days. Objective tumor response was evaluated after two courses of therapy.

RESULTS

Fourteen patients were evaluable for response and toxicity. No objective responses were seen. The median (range) time to progression and survival were 14 (1.6-37), and 15 (1.9-62) weeks, respectively. Toxicity was mild with severe (grade 3 or 4) hyperbilirubinemia, pain, diarrhea, transaminitis, venous thrombus, weakness, renal failure, confusion, and edema/ascites seen in three (21%), one (7%), two (14%), one (7%), one (7%), one (7%), one (7%), one (7%), and two (14%) patients, respectively.

CONCLUSION

In the 14 patients evaluable, UFT 300 mg/m2/d plus oral leucovorin 90 mg/d administered for 28 days did not demonstrate anti-tumor activity against advanced pancreatic adenocarcinoma; however, this oral regimen was well tolerated and devoid of neutropenia, significant oral mucositis or diarrhea.

The diagnostic and predictive value of ascites nitric oxide levels in patients with spontaneous bacterial peritonitis

Nitric oxide (NO) is a messenger molecule involved in pathogen suppression. Cirrhosis is characterized by an increased risk for infections, including spontaneous bacterial peritonitis (SBP). The role of NO in the infections that develop in cirrhosis has not been clearly established. The aim of this study was to investigate the utility of measuring ascites NO in the diagnosis of SBP and/or in determining the predisposition of cirrhotic patients to develop this infection. Nitric oxide metabolites (nitrites + nitrates [NOx]) were measured by chemiluminescence in 105 ascites samples obtained from 87 cirrhotic patients and in 87 simultaneously obtained serum samples. Ascites NO levels were not significantly different among ascites from patients with SBP (n = 39; median, 48 micromol/L), patients with sterile ascites (n = 54; median, 42 micromol/L), and samples obtained after patients with SBP had been treated (n = 12; median, 62 micromol/L). No differences in ascites NO levels were observed between culture-positive and culture-negative peritonitis. Among 50 patients with sterile ascites on initial paracentesis, 7 patients developed peritonitis during follow-up; no differences in baseline NO levels were observed between patients who developed peritonitis (median, 46 micromol/L) and those who did not (median, 41 micromol/L). Among patients with SBP, mortality was significantly higher in those with NO levels >60 micromol/L. A very significant direct correlation was found between ascites and serum NO levels (r2 = .86). In conclusion, ascites NO levels in cirrhotic patients are not useful either to diagnose or to determine predisposition to SBP. Rather, ascites NO levels reflect serum levels, are higher in cirrhotic patients with more severe liver disease, and may be a useful prognostic marker.

Phase II and pharmacodynamic studies of pyrazine diazohydroxide (NSC 361456) in patients with advanced renal and colorectal cancer

Pyrazine diazohydroxide (PZDH) is a novel antitumor agent that forms DNA adducts via the reactive pyrazine diazonium ion. In a recent Phase I study of PZDH, we identified a recommended Phase II dose of 100 mg/m2/day x 5, given as a 5-min i.v. bolus with the cycles repeated every 42 days (N. J. Vogelzang, et al, Cancer Res., 54: 114-119, 1994). There was a moderate negative correlation between serum chloride concentration and logarithm platelet nadir, suggesting the hypothesis that PZDH is activated in an acidic environment, leading to more toxicity in acidotic patients. Therefore, the University of Chicago Phase II cooperative network conducted two Phase II studies of PZDH in renal cancer (15 patients, 2 with liver metastases) and in 5-fluorouracil-refractory colorectal cancer (14 patients, 13 with liver metastases) to determine efficacy in each disease and to correlate safety and tolerance of the drug with PZDH pharmacokinetics/pharmacodynamics and with arterial blood gas measurements. There were no responses seen in either tumor type. The primary toxicity of PZDH was myelosuppression with neutropenia (absolute neutrophil count, < 1000/microl) and thrombocytopenia (<50,000 cells/microl), seen in 41 and 24% of all cycles, respectively. Other grade 3 and 4 toxicities were rare. Pharmacodynamic analysis revealed no significant correlation between plasma levels at 5, 60, and 120 min; WBCs; absolute neutrophil and platelet count nadirs; and initial serum chloride or blood pH levels. The colorectal patients experienced significantly more thrombocytopenia than did the renal cancer patients (median platelet nadir after cycle 1 was 151 x 10(3)/microl for renal patients versus 76 x 10(3)/microl for colon patients; P = 0.04), suggesting either that prior 5-fluorouracil and leucovorin reduced bone marrow reserve or that colorectal patients with liver metastases experienced more PZDH toxicity. Regression analyses revealed a possible relationship (P = 0.06) between serum pH and thrombocytopenia (i.e., for each increase of 0.03 in pH, there was a 34% increase in the platelet nadir), but there was no relationship between serum chloride and thrombocytopenia. Curiously, an increase in alkaline phosphatase was associated with an increase in the platelet nadir (P = 0.02). If PZDH continues to be developed as an antineoplastic agent, further studies of these relationships are suggested.

Aprotinin effects related to oxidative stress in cardiosurgery with mechanical cardiorespiratory support (CMCS)

There is evidence to support a relationship between oxidative stress and protease release in "ischemia-reperfusion damage." We have proposed that aprotinin may exert an antioxidant effect. A double blind clinical trial was performed with a control (G-1) and treated (G-2) groups, both submitted to CMCS. Blood samples were taken 5 times. Biochemical indicators were measured spectrophotometrically. Aprotinin was supplied by Bayer. Malonildialdehyde levels were greater in G-1 (7.2 +/- 3.6 nmoles/ml) than in G-2 (4 +/- 1.65) at the time of reperfusion. Phospholipase A2 exhibited a tendency of higher activity in G-1 than in G-2. Uric acid levels were higher in G-2 (431 +/- 274 mumoles/1) than in G-1 (224 +/- 188) at 5 minutes after aortic clamping, and catalase activity was greater in G-2 (294 +/- 55 KU/1) than in G-1 (118 +/- 47) at time of reperfusion. Low cardiac output was 10% in G-2 and 30% in G-1. Arrythmias appeared in 30% of G-2 and in 60% of G-1. These results suggest an antioxidant effect of aprotinin under ischemia-reperfusion conditions.

Use of cyanoacrylate tissue adhesive in small-incision cataract surgery

BACKGROUND AND OBJECTIVE

A controlled clinical study was performed on three different groups of patients.

PATIENTS AND METHODS

Each patient had a 6.5 mm-wide scleral tunnel with phacoemulsification. Sealing of the incision was done either without suture, with an anchor suture, or with tissue adhesive (cyanoacrylate). The authors observed whatever induced astigmatism was present during the 1st and 12th weeks of the postoperative period.

RESULTS

In the immediate postoperative period, astigmatism was significantly less (P < .01) in the groups of patients with suture and tissue adhesive than in the unsutured group. The results after 12 weeks were similar for the three groups (P > .05), with no complications observed as a result of the use of cyanoacrylate.

CONCLUSION

Cyanoacrylate seems to be a promising innovation in scleral tunnel surgery for cataracts. It is an effective, a quick, and a safe alternative to sutures.

Teamwork improves breast cancer management in the community

The weekly breast cancer conference has clearly improved this community's ability to care for breast cancer patients. The range of issues has been broad. Some of the discussions are related to various aspects of surgical care, pathology issues such as specimen marking and evaluation, the use of prognostic indicators, adjuvant treatment, hormone replacement, bone marrow transplantation, post lumpectomy mammography, etc. The list is endless and expands every week. This conference format is very feasible in a community setting and has ongoing in-depth benefits. Each host hospital designates one person to regularly coordinate preparation of the host hospital's conference. This ensures timely retrieval of all related diagnostic information for review by the radiologist and pathologist. Additionally, the case history is typed and available only on the morning of the conference.

Concomitant chemoradiotherapy, neutron boost, and adjuvant chemotherapy for anaplastic astrocytoma and glioblastoma multiforme

The survival rate for patients with malignant gliomas is poor. We describe the results of a prospective study using concomitant chemoradiotherapy, neutron boost, and adjuvant chemotherapy for patients with malignant gliomas. Forty-two patients with anaplastic astrocytoma (AA) and glioblastoma multiforme (GBM) were treated with postoperative photon radiation 45 Gy/25 fraction (fxs) with concomitant continuous intravenous infusion of 5-fluorouracil at 300 mg/m2/day x 5 days and hydroxyurea 0.5 g orally every 12 hr for 6 days for 5 consecutive weeks, followed by a neutron boost of 450 N cGy/6 fxs delivered twice weekly. Adjuvant chemotherapy with procarbazine, CCNU, and vincristine (PCV) was given up to 1 year or until tumor progression. Thirty-four patients (81%) had GBM and 8 patients (19%) had AA. Sixteen patients (38%) were ineligible for the neutron boost because of large tumors or poor performance status and instead received a photon boost with concomitant chemotherapy for a total dose of 60-65 Gy to the tumor. The overall median survival is 68 weeks at a median follow-up of 203 weeks (range 166-302 weeks for the 11 patients remaining alive); 7/8 patients with AA are alive, 2 of these with progressive disease. For AA the median survival is not reached at a median follow-up of 203 weeks (range 166-302 weeks for the 7 patients alive with AA). Time to tumor progression for the 1 dead patient with AA was 35 weeks and the other 2 patients failed at 171 weeks and 179 weeks following treatment. The median survival for the 34 patients with GBM was 62 weeks; 4/34 patients with GBM are alive at 285, 238, 216, and 206 weeks. Multivariate survival analysis in the 34 patients with GBM revealed age and Karnofsky performance status as important prognostic factors. Extent of surgery and neutrons did not affect survival. Concomitant chemoradiotherapy was well tolerated by all patients. The only toxicities observed were mucositis < or = grade II in 3 patients (7%) and mild myelosuppression in 1 patient (2.4%). Adjuvant PCV was well tolerated. Continuous concomitant chemoradiotherapy was well tolerated by all patients with acceptable side effects. The survival rate for the patients with GBM suggests no significant impact on the prognosis for these patients. Patients with AA did well; however, the patient numbers are small.

The benefit of lateral radiographs in an intensive care unit

The portable anteroposterior (AP) radiograph (CXR) is an essential component of clinical management in the intensive care unit (ICU). In view of the immobility of patients, and overlying tubes, wires, and catheters, lateral (LAT) CXRs are infrequently ordered. We constructed a portable acrylic (Plexiglas) CXR cassette holder and were able to obtain reproducible quality LAT CXRs in the ICU. Of the 72 simultaneously obtained AP and LAT CXRs, 60 were technically acceptable for interpretation. We found an 11 percent incidence of either unexpected conditions or we were able to improve on the AP CXR interpretation. Lateral CXRs should be obtained routinely in the ICU in select patients.

Subclinical ductal carcinoma in situ of the breast. Treatment by local excision and surveillance alone

BACKGROUND

Mammography has led to earlier detection of subclinical ductal carcinoma in situ (DCIS) of the breast either as nonpalpable calcifications or as an incidental finding in a biopsy performed for another reason. Many women in whom DCIS was detected early may not be destined to have an invasive carcinoma. How should subclinical DCIS be treated if that is the case? What is the role of excision and surveillance only as an alternative to mastectomy or irradiation?

METHODS

All patients with DCIS detected as nonpalpable calcifications or as an incidental finding were eligible for this study. Diagnosis was confirmed, and the histologic subtype was determined. Results of postbiopsy mammography confirmed excision of calcifications; wide local reexcision and assessment of margins was also performed in most patients. The maximum diameter of calcifications considered suitable for this treatment was 25 mm.

RESULTS

Between 1978 and 1990, 70 women (72 breasts) were entered into this study (mean follow-up time, 49 months; median follow-up time, 47 months). Of this group, 66% were detected as calcifications and 33% were detected as incidental findings. The recurrence rate was 15.3%. All but one of the patients who experienced a recurrence had the comedo type of DCIS as the initial lesion. Each of the recurrences was of the comedo type. All but one recurrence was at the same site as the primary lesion. None of the patients with DCIS as an incidental finding experienced a recurrence.

CONCLUSIONS

Excision and surveillance is a reasonable alternative to mastectomy or irradiation for selected women with DCIS that presents as nonpalpable calcifications or as an incidental finding.

Amino acid substitutions at tryptophan 388 and tryptophan 412 of the HepG2 (Glut1) glucose transporter inhibit transport activity and targeting to the plasma membrane in Xenopus oocytes

All 6 tryptophan residues in the human HepG2-type glucose transporter (Glut1) were individually altered by site-directed mutagenesis to investigate the role of these residues in transport function. Tryptophan residues in positions 48, 65, 186, 363, 388, and 412 of Glut1 were changed to either a glycine or leucine residue. Mutant mRNAs were synthesized and injected into Xenopus laevis oocytes. Transporter function as assessed by uptake of 2-deoxy-D-[3H]glucose or transport of 3-O-[3H]methylglucose was decreased in the 388 and 412 mutants but was unaltered in all other mutants. The amount of the mutant transporters expressed in total membrane and plasma membrane fractions was measured using Glut1-specific antibodies. Calculation of the intrinsic transport activity of each of the mutants using these data demonstrated that the reduced transport activity of the 412 mutants was caused entirely by a dramatic decrease in the intrinsic activity of the mutant proteins whereas the reduced activity of the 388 mutants was a result of a decreased level of the protein in oocytes, decreased targeting to the plasma membrane, and a modest decrease in the intrinsic activity. Protease/glycosidase mapping of in vitro translation products indicated that the effects of the 388 and 412 point mutations could not be attributed to a disruption in the ability of the mutant proteins to insert properly into the membrane. The ID50 for cytochalasin B inhibition of 2-deoxyglucose uptake was increased from 5 x 10(-7) M for the wild-type Glut1 to 4 x 10(-6) M in the 388 mutants but was unaltered in the 412 mutants. These observations suggest that 1) Trp-412 may comprise part of a hexose binding site or is involved in maintaining a local tertiary structure critical for transport function; 2) Trp-388 is involved in stabilizing the equilibrium binding of cytochalasin B to the transporter. Trp-388 may therefore lie near a substrate binding site and also appears to participate in stabilization of local tertiary structure important for full catalytic activity and efficient targeting to the Xenopus plasma membrane.