Hydrogen sensor based on metallic photonic crystal slabs.

We present a hydrogen sensor based on metallic photonic crystal slabs. Tungsten trioxide (WO(3)) is used as a waveguide layer below an array of gold nanowires. Hydrogen exposure influences the optical properties of this photonic crystal arrangement by gasochromic mechanisms, where the photonic crystal geometry leads to sharp spectral resonances. Measurements reveal a change of the transmission depending on the hydrogen concentration. Theoretical limits for the detection range and sensitivity of this approach are discussed.

Correlation effects in disordered metallic photonic crystal slabs.

We analyze the influence of correlations on the optical properties of disordered metallic photonic crystal slabs experimentally and theoretically. Different disorder models with different nearest-neighbor correlations are considered. We present a theory that allows us to quantitatively calculate the optical properties of the different samples. We find that different kinds of correlations produce characteristic spectral features such as peak reduction and inhomogeneous broadening. These features are caused by reduced excitation efficiencies and the excitation of multiple resonances.

The relationship of disease severity, health beliefs and medication adherence among HIV patients.

The objective was to investigate the relationship of disease severity, health beliefs and medication adherence among HIV/AIDS patients. A survey was administered to 72 patients in three different stages of HIV/AIDS (CDC clinical categories A, B, C). Multivariate analyses revealed that there were no significant differences in patients' perceptions of the severity of HIV/AIDS or perceptions of the benefits and barriers for the treatment across three disease stages. However, the most severely ill patients (in stage C) perceived a higher risk of complications if they did not take their medicine as prescribed compared to asymptomatic patients (stage A) (p = 0.01). Also, patients in stages B and C were more adherent to their medications compared to patients in stage A (p = 0.007). Finally, perceived susceptibility-inaction was positively related to medication adherence (p = 0.005) and difficulty in following doctors' instructions was negatively related to patients' medication adherence (p = 0.009). In conclusion, patients' illness experiences are associated with their beliefs about the chances of developing complications if they do not adhere to their medications. Patients who have experienced more complications perceive a stronger relationship between medication non-adherence and AIDS-related complications, and are also more adherent to their medication regimen when compared to patients with no prior complications.

Congruence of three self-report measures of medication adherence among HIV patients.

OBJECTIVE: To evaluate the accordance between three measures of self-reported medication adherence. METHODS: A survey was administered to HIV patients. The three adherence measures included a four-item Morisky-type scale (Measure1) and two measures defining adherence as the percentage of doses taken as prescribed during the past two days (Measure2) or past two weeks (Measure3). RESULTS: For Measure1, 29.2% of the patients were categorized as high adherence and 61.5% as medium adherence. For Measure2 and Measure3, the mean scores were 93.6% and 96.5%, respectively. Using 90% as cutoff values, 78.5% and 95.4% of the patients were classified as adherent by Measure2 and Measure3, respectively (kappa = 0.30; p = 0.001). When 80% was used, 90.8% of the patients were classified as adherent for Measure2 and 96.9% for Measure3 (kappa = 0.48; p < 0.001). When using 90% and 80% as cutoff values to categorize Measure2 and Measure3 as three levels, there was no agreement between Measure1 and the other two measures. The accordance of Measure2 and Measure3 was significant albeit not high (kappa = 0.31; p < 0.001). CONCLUSIONS: The accordance between a Morisky-type adherence scale and measures of missed doses is unsatisfactory. However, "missed-dose" measures using two-day or two-week time periods yield fairly similar results. Researchers should be cautious when comparing adherence rates between studies that use different methods for assessing adherence.

Rapid method for the solid-phase extraction and GC-MS analysis of flunitrazepam and its major metabolites in urine.

Recently, flunitrazepam (Rohypnol) has become an increasingly popular drug of abuse among young adults, who take it for its euphoric effects. In other cases, the drug has been used by rapists for its sedative and hypnotic effects that can induce a catatonialike trance and memory loss in potential victims; as a result, it has been nicknamed the "date-rape drug". For these reasons, the Drug Enforcement Administration recently considered adding the drug (a.k.a. "Roofies") to the same category as heroin and LSD. A selective and sensitive technique has been developed for extracting, detecting, and identifying flunitrazepam and its two major metabolites (7-aminoflunitrazepam and N-desmethylflunitrazepam) in human urine. Using a solid-phase extraction cartridge containing a "mixed-mode" bonded silica gel (Bond Elut Certify), flunitrazepam and its metabolites were selectively isolated from other urine components and quantitated and identified by gas chromatography-tandem mass spectrometry with a benchtop ion mass spectrometer. The extraction method is rapid, reproducible, and precise, and it has a broad linear working range. The overall extraction efficiency was found to be more than 90% for the parent drug as well as the two major metabolites.

Patients' perceptions of the benefits of pharmaceutical care.

OBJECTIVE: To investigate patients' perceptions of the benefits of regular participation in pharmaceutical care services. DESIGN: Written survey of a convenience sample. SETTING: Pharmacist-run anticoagulation clinic in a Veterans Administration Medical Center. PATIENTS: 154 patients who had regularly scheduled appointments in the clinic. INTERVENTIONS: Patients were asked to complete a written survey. The survey was read to those who had trouble reading it. MAIN OUTCOME MEASURES: Patients' perceptions about the benefit of services provided in the clinic and the relationship between those services and reduced risks of medication-related problems. RESULTS: All components of anticoagulant-related pharmaceutical care were rated as at least fairly beneficial. Monitoring of warfarin blood levels and information on the appropriate use of warfarin were rated highest. The perceived benefits of the pharmaceutical care components were associated with patients' perceptions of the extent to which pharmaceutical care reduced their risk of experiencing blood clots or warfarin-related problems. Patients also perceived that their risk of developing blood clots or bleeding problems would be higher if they did not regularly visit the anticoagulation clinic. CONCLUSION: Patients' perceptions of the benefits of pharmaceutical care were associated with the perceived threat reduction capacity of the pharmacist's services. Pharmaceutical care providers may be able to enhance patient participation in their services by educating patients on the risks of medication-related problems and how frequent monitoring of key clinical indicators may help reduce those risks.

Evaluation of patient's Health-Related Quality of Life using a modified and shortened version of the Living With Asthma Questionnaire (ms-LWAQ) and the medical outcomes study, Short-Form 36 (SF-36).

OBJECTIVE: The specific objectives of this study were to: 1) study the effect of moderate-to-severe asthma on patient's Health-Related Quality of Life (HRQoL) as measured by the Medical Outcomes Study 36-item Short-Form Health Survey (SF-36) and 2) evaluate the construct validity of a modified and shortened version of the Living With Asthma Questionnaire (ms-LWAQ) using the SF-36 as a concomitant measure of HRQoL. METHODS: Cross-sectional, telephone or mail surveys of asthmatic patients enrolled in two central Florida managed care organizations. RESULTS: All subscales of the SF-36 and four subscales of the ms-LWAQ demonstrated adequate reliability in this population (Cronbach alpha > 0.72). The subscales of the SF-36 most affected by patient's asthma were: general health perceptions, vitality and physical role functioning. These three subscales were correlated with four subscales of the ms-LWAQ: consequences, seriousness, affect and leisure. Six of the eight SF-36 subscales and all of the ms-LWAQ subscales were associated with patient's emergency department and hospital utilization. CONCLUSION: The ms-LWAQ and SF-36 are valid as useful measures of asthma patient's HRQoL in this cross-sectional study. Severity of disease, as measured by health care utilization, was significantly associated with HRQoL.

State pharmacy regulators' opinions on regulating pharmaceutical care outcomes.

OBJECTIVE: To examine the opinions of state pharmacy regulators regarding responsibility for the outcomes of drug therapy, and approaches that might be taken to regulate for pharmaceutical care outcomes. DESIGN: Surveys were sent to the executive secretaries of state pharmacy boards. The executive secretaries were encouraged to seek input from other board staff and board members in formulating a response. Reminder postcards were sent to all subjects 1 week after the initial mailing. MEASURES: The survey instrument was divided into three sections. The first section identified 10 approaches that state boards could use to regulate for outcomes and asked subjects to indicate the utility of each. The second and third sections asked the subjects to determine the extent to which pharmacies and pharmacists, respectively, should be responsible for outcomes potentially related to pharmaceutical care. RESULTS: Forty-one usable surveys were returned. All approaches to regulation were viewed as potentially useful, and scores for three approaches indicated that they would be consistently helpful for effective regulation of pharmaceutical care outcomes. The pharmacy was viewed as solely responsible for poor outcomes related to systems deficiencies, a lack of self-assessment, inadequate references, equipment, and technician support. Pharmacists were assigned greatest responsibility for outcomes related to prescription filling, and less responsibility for outcomes related to patient care. However, there was considerable variation in responses to many of the items, reflecting the diverse opinions of pharmacy regulators on these issues. CONCLUSIONS: While pharmacy regulators appear open to some outcomes-oriented approaches to regulation, there is no clear consensus on responsibility for pharmaceutical care outcomes.

[Multicentricity in renal adenocarcinoma: its incidence and the therapeutic implications]. / Multicentricidad en el adenocarcinoma renal: incidencia e implicaciones terapéuticas.

Unsuspected multicentricity in single Renal Adenocarcinoma (RAC) together with the prospects of incomplete neoplasia removal are the 2 major disadvantages for the acceptance of traditional renal surgery in birenal carriers of medium size, low grade single RAC. This paper is a retrospective review of our series of RAC patients who underwent radical nephrectomy between January 1986 and October 1994 with the following purpose: 1) To evaluate our incidence of unsuspected multicentricity. 2) To evaluate the characteristics of such multicentricity. 3) To evaluate, in the assumption that traditional surgery had been indicated for patients with small size RAC, in how many patients tumoral resection would have been incomplete due to existence of satellite tumoral nodes in the preserved renal parenchyma. Of 110 patients undergoing radical nephrectomy, 11.8% (13/110) had unsuspected multicentricity. In 10 patients there was multiple satellite nodes with size ranging from 0.3 to 3 cm. We conclude that there is not relationship between multicentricity and size or stage of primary tumour and that, by applying strict criteria (size, location, well defined tumoral wall and form of presentation) to select the patients who can be candidates to traditional renal surgery, the probability to perform it in patients with multicentric RAC would be considerably reduced.

The behaviour of liposarcoma in tissue culture. A specific growth pattern.

There have been few studies of liposarcoma in tissue culture. We report a study of 27 cases of liposarcoma including examples of all subtypes in tissue culture. All the cases showed a uniform growth pattern of glass adherence by polygonal cells with short processes distributed in a random fashion. The cytoplasm of these cells became progressively loaded with glycogen followed by lipid droplets. These lipid droplets tended to fuse progressively to form a single or dominant vacuole. At the same time, the cells tended to adopt a rounded shape. This pattern of growth, which was seen in all subtypes of liposarcoma with minimal variation, is different from that shown by other soft tissue tumours and is similar to the growth of embryonal fat in tissue culture.

Effects of inhibitors of ornithine decarboxylase on the differentiation of mouse neuroblastoma cells.

(R, S)-alpha-Fluoromethylornithine (alpha-FMO), a catalytic irreversible inhibitor of ornithine decarboxylase (L-ornithine carboxy-lyase, EC 4.1.1.17), induced the differentiation of N2a mouse neuroblastoma cells. The effect of alpha-FMO was concentration dependent; approximately 50% of the cell population exhibited neurite outgrowth in the presence of 1 mM alpha-FMO, while higher concentrations caused severe growth inhibition and cell death. The effect of 1 mM alpha-FMO on neuroblastoma differentiation was potentiated greatly by 0.1 to 0.2 mM N6,O2'-dibutyryl adenosine cyclic 3':5'-monophosphate (Bt2cAMP) causing more than 90% of the cell population to differentiate morphologically with thick and long processes; 0.1 to 0.2 mM Bt2cAMP, by itself, had no effect on cell growth and did not induce neurite outgrowth. The effect of alpha-FMO, either by itself or in combination with 0.1 to 0.2 mM Bt2cAMP, on the morphological differentiation of mouse neuroblastoma cells was reversed by the addition of exogenous putrescine or spermidine. The morphological differentiation of mouse neuroblastoma cells induced by 1 mM alpha-FMO plus 0.2 mM Bt2cAMP was accompanied by increases of the regulatory subunit of the type I cAMP-binding protein and acetylcholinesterase activity. These results indicate that the modulation of cellular polyamine contents may be important in neuroblastoma cell differentiation.