The basic-helix-loop-helix-PAS orphan MOP3 forms transcriptionally active complexes with circadian and hypoxia factors

We report that MOP3 is a general dimerization partner for a subset of the basic-helix-loop-helix (bHLH)-PER-ARNT-SIM (PAS) superfamily of transcriptional regulators. We demonstrated that MOP3 interacts with MOP4, CLOCK, hypoxia-inducible factor 1alpha (HIF1alpha), and HIF2alpha. A DNA selection protocol revealed that the MOP3-MOP4 heterodimer bound a CACGTGA-containing DNA element. Transient transfection experiments demonstrated that the MOP3-MOP4 and MOP3-CLOCK complexes bound this element in COS-1 cells and drove transcription from a linked luciferase reporter gene. We also deduced the high-affinity DNA binding sites for MOP3-HIF1alpha complex (TACGTGA) and used transient transfection experiments to demonstrate that the MOP3-HIF1alpha and MOP3-HIF2alpha heterodimers bound this element, drove transcription, and responded to cellular hypoxia. Finally, we found that MOP3 mRNA expression overlaps in a number of tissues with each of its four potential partner molecules in vivo.

Gold nanoparticles as novel agents for cancer therapy

Gold nanoparticles are emerging as promising agents for cancer therapy and are being investigated as drug carriers, photothermal agents, contrast agents and radiosensitisers. This review introduces the field of nanotechnology with a focus on recent gold nanoparticle research which has led to early-phase clinical trials. In particular, the pre-clinical evidence for gold nanoparticles as sensitisers with ionising radiation in vitro and in vivo at kilovoltage and megavoltage energies is discussed.

Incidence and preventability of adverse drug events in nursing homes

PURPOSE

Adverse drug events, especially those that may have been preventable, are among the most serious concerns about medication use in nursing homes. We studied the incidence and preventability of adverse drug events and potential adverse drug events in nursing homes.

METHODS

We performed a cohort study of all long-term care residents of 18 community-based nursing homes in Massachusetts during a 12-month observation period. Potential drug-related incidents were detected by stimulated self-report by nursing home staff and by periodic review of the records of nursing home residents by trained nurse and pharmacist investigators. Each incident was classified by 2 independent physician-reviewers, using a structured implicit review process, by whether or not it constituted an adverse drug event or potential adverse drug event (those that may have caused harm, but did not because of chance or because they were detected), by the severity of the event (significant, serious, life-threatening, or fatal), and by whether it was preventable. Examples of significant events included nonurticarial rashes, falls without associated fracture, hemorrhage not requiring transfusion or hospitalization, and oversedation; examples of serious events included urticaria, falls with fracture, hemorrhage requiring transfusion or hospitalization, and delirium.

RESULTS

During 28,839 nursing home resident-months of observation in the 18 participating nursing homes, 546 adverse drug events (1.89 per 100 resident-months) and 188 potential adverse drug events (0.65 per 100 resident-months) were identified. Of the adverse drug events, 1 was fatal, 31 (6%) were life-threatening, 206 (38%) were serious, and 308 (56%) were significant. Overall, 51% of the adverse drug events were judged to be preventable, including 171 (72%) of the 238 fatal, life-threatening, or serious events and 105 (34%) of the 308 significant events (P < 0.001). Errors resulting in preventable adverse drug events occurred most often at the stages of ordering and monitoring; errors in transcription, dispensing, and administration were less commonly identified. Psychoactive medications (antipsychotics, antidepressants, and sedatives/hypnotics) and anticoagulants were the most common medications associated with preventable adverse drug events. Neuropsychiatric events were the most common types of preventable adverse drug events.

CONCLUSIONS

Adverse drug events are common and often preventable in nursing homes. More serious adverse drug events are more likely to be preventable. Prevention strategies should target the ordering and monitoring stages of pharmaceutical care.

A PEGylated dendritic nanoparticulate carrier of fluorouracil

The present study was aimed at developing and exploring the use of uncoated and PEGylated newer PAMAM dendrimers for delivery of anti-cancer drug 5-fluorouracil. For this study, successive Michael addition and exhaustive amidation reactions were used to synthesize 4.0 G PAMAM dendrimers, using ethylenediamine as core and methylmethacrylate as propagating agent. The dendrimer was PEGylated using N-hydroxysuccinimide-activated carboxymethyl MPEG-5000. IR and NMR data proved the synthesis. Various physicochemical parameters, SEM, TEM, lambda(max) values, hemolytic toxicity, drug entrapment, drug release and blood-level studies of both PEGylated and non-PEGylated systems were determined and compared. The PEGylation of the systems was found to have increased their drug-loading capacity, reduced their drug release rate and hemolytic toxicity. TEM study revealed surface properties of the systems. Stability studies had shown its stability at room temperature in dark. The systems were found suitable for prolonged delivery of an anti-cancer drug by in vitro and blood-level studies in albino rats, without producing any significant hematological disturbances. PEGylation has been found to be suitable for modification of PAMAM dendrimers for reduction of drug leakage and hemolytic toxicity. This, in turn, could improve drug-loading capacity and stabilize such systems in body. The study suggests use of such PEGylated dendrimeric systems as nanoparticulate depot type of system for drug administration.

Erythrocyte membrane lipid peroxidation and glycosylated hemoglobin in diabetes

Erythrocytes of diabetic patients have abnormal membrane properties. We examined in vivo membrane lipid peroxidation in erythrocytes of diabetic subjects and its possible relationship with hyperglycemia. Lipid peroxidation was assessed in fresh, untreated erythrocytes by quantitating thiobarbituric acid reactivity and an adduct of phospholipids and malonyldialdehyde (MDA), an end product of lipid peroxidation, with thin-layer chromatography of lipid extract of diabetic erythrocytes. There was a significantly increased membrane lipid peroxidation in diabetic erythrocytes compared with nondiabetic erythrocytes. The degree of membrane lipid peroxidative damage in erythrocytes was significantly correlated with the level of glycosylated hemoglobin, an index of mean glucose level for the preceding 3-4 mo. This suggests that peroxidation of membrane lipids and accumulation of MDA occurs in erythrocytes of diabetic patients.

Discovery of fifth serotype of dengue virus (DENV-5): A new public health dilemma in dengue control

Dengue fever is a re-emerging public health problem with two-fifths of the world population being at risk of infection. Till now, dengue fever was believed to be caused by four different serotypes. The fifth variant DENV-5 has been isolated in October 2013. This serotype follows the sylvatic cycle unlike the other four serotypes which follow the human cycle. The likely cause of emergence of the new serotype could be genetic recombination, natural selection and genetic bottlenecks. There is no indication of the presence of DENV-5 in India. Recent clinical trials with the promising Chimerivax tetravalent vaccine suffered a setback. Discovery of DENV-5 and more such sylvatic strains in future may further impede the Dengue Vaccine Initiative. Integrated Vector Management holds the key to sustainable dengue control. Further epidemiological and ecological studies are needed to detect additional sylvatic dengue strains.

Induction of hepatic antioxidants in freshwater catfish (Channa punctatus Bloch) is a biomarker of paper mill effluent exposure

Enzymatic and non-enzymatic antioxidants serve as an important biological defense against environmental oxidative stress. Information on antioxidant defense in fish is meager despite that fish are constantly exposed to a myriad of environmental stress including the oxidants. This study, therefore, assesses the activities of antioxidant enzymes viz., glutathione peroxidase, catalase and glutathione S-transferase and the non-enzymatic antioxidants viz., glutathione and metallothionein in various tissues of freshwater fish Channa punctatus (Bloch), in response to short-term and long-term exposures to paper mill effluent. The fish were exposed to the effluent at a concentration of 1.0% (v/v) for 15, 30, 60 and 90 days. The exposure caused a time-dependent increase in glutathione level (P < 0.001), activities of glutathione peroxidase (P < 0.05 to P < 0.001), glutathione S-transferase (P < 0.001) and a marginal initial decrease in catalase activity in the liver (P < 0.01 to P < 0.001). Metallothionein was induced in liver after 60 days of exposure. Two isoforms of metallothionein were detected. Catalase activity also increased 60 days afterwards. Antioxidant pattern was different in gill and kidney showing that liver was more resistant to oxidative damage as compared to gills and kidney. Our results demonstrate a pollutant-induced adaptive response in fish. In addition, levels of enzymatic and non-enzymatic tissue antioxidants may serve as surrogate markers of exposure to oxidant pollutants in fish.

Risk factors for adverse drug events among nursing home residents

BACKGROUND

In a prospective study of nursing home residents, we found adverse drug events (ADEs) to be common, serious, and often preventable. To direct prevention efforts at high-risk residents, information is needed on resident-level risk factors.

METHODS

Case-control study nested within a prospective study of ADEs among residents in 18 nursing homes. For each ADE, we randomly selected a control from the same home. Data were abstracted from medical records on functional status, medical conditions, and medication use.

RESULTS

Adverse drug events were identified in 410 nursing home residents. Independent risk factors included being a new resident (odds ratio [OR], 2.8; 95% confidence interval [CI], 1.5-5.2) and taking anti-infective medications (OR, 4.0; CI, 2.5-6.2), antipsychotics (OR, 3.2; CI, 2.1-4.9), or antidepressants (OR, 1.5; CI, 1.1-2.3). The number of regularly scheduled medications was associated with increased risk of ADEs; the OR associated with taking 5 to 6 medications was 2.0 (CI, 1.2-3.2); 7 to 8 medications, 2.8 (CI, 1.7-4.7); and 9 or more, 3.3 (CI, 1.9-5.6). Taking supplements or nutrients was associated with lower risk (OR, 0.42; CI, 0.27-0.63). Preventable ADEs occurred in 226 residents. Independent risk factors included taking opioid medications (OR, 6.6; CI, 2.3-19.3), antipsychotics (OR, 4.0; CI, 2.2-7.3), anti-infectives (OR, 3.0; CI, 1.6-5.8), antiepileptics (OR, 2.2; CI, 1.1-4.5), or antidepressants (OR, 2.0; CI, 1.1-3.5). Scores of 5 or higher on the Charlson Comorbidity Index were associated with increased risk of ADEs (OR, 2.6; CI, 1.1-6.0). The number of regularly scheduled medications was also a risk factor: the OR for 7 to 8 medications was 3.2 (CI, 1.4-6.9) and for 9 or more, 2.9 (CI, 1.3-6.8). Residents taking nutrients or supplements were at lower risk (OR, 0.27; CI, 0.14-0.50).

CONCLUSIONS

It is possible to identify nursing home residents at high risk of having an ADE. Particular attention should be directed at new residents, those with multiple medical conditions, those taking multiple medications, and those taking psychoactive medications, opioids, or anti-infective drugs.

Isolation and characterization of PBP, a protein that interacts with peroxisome proliferator-activated receptor

In an attempt to identify cofactors that could possibly influence the transcriptional activity of peroxisome proliferator-activated receptors (PPARs), we used a yeast two-hybrid system with Gal4-PPARgamma as bait to screen a mouse liver cDNA library and have identified steroid receptor coactivator-1 (SRC-1) as a PPAR transcriptional coactivator. We now report the isolation of a cDNA encoding a 165-kDa PPARgamma-binding protein, designated PBP which also serves as a coactivator. PBP also binds to PPARalpha, RARalpha, RXR, and TRbeta1, and this binding is increased in the presence of specific ligands. Deletion of the last 12 amino acids from the carboxyl terminus of PPARgamma results in the abolition of interaction between PBP and PPARgamma. PBP modestly increased the transcriptional activity of PPARgamma, and a truncated form of PBP (amino acids 487-735) acted as a dominant-negative repressor, suggesting that PBP is a genuine coactivator for PPAR. In addition, PBP contains two LXXLL signature motifs considered necessary and sufficient for the binding of several coactivators to nuclear receptors. In situ hybridization and Northern analysis showed that PBP is expressed in many tissues of adult mice, including the germinal epithelium of testis, where it appeared most abundant, and during ontogeny, suggesting a possible role for this cofactor in cellular proliferation and differentiation.

Expression of ARNT, ARNT2, HIF1 alpha, HIF2 alpha and Ah receptor mRNAs in the developing mouse

The basic helix-loop-helix-PAS (bHLH-PAS) protein ARNT is a dimeric partner of the Ah receptor (AHR) and hypoxia inducible factor 1 alpha(HIF1 alpha). These dimers mediate biological responses to xenobiotic exposure and low oxygen tension. The recent cloning of ARNT and HIF1(homologues (ARNT2 and HIF2 alpha) indicates that at least six distinct bHLH-PAS heterodimeric combinations can occur in response to a number of environmental stimuli. In an effort to understand the biological relevance of this combinatorial complexity, we characterized their relative expression at a number of developmental time points by parallel in situ hybridization of adjacent tissue sections. Our results reveal that in general there is limited redundancy in the expression of these six transcription factors and that each of these bHLH-PAS members displays a unique pattern of developmental expression emerging as early as embryonic day 9.5.

Microsatellite evolution--evidence for directionality and variation in rate between species

Microsatellite DNA sequences are rapidly becoming the dominant source of nuclear genetic markers for a wide range of applications, from genome mapping to forensic testing to population studies. If misinterpretation is to be avoided, it is vital that we understand fully the way in which microsatellite sequences evolve. We have therefore compared allele length distributions for 42 microsatellites in humans with their homologues in a range of related primates. We find a highly significant trend for the loci to be longer in humans, showing that microsatellites can evolve directionally and at different rates in closely related species.

Diagnostic criteria for Takayasu arteritis

Diagnosis of Takayasu arteritis (TA) is often delayed because of a non-specific clinical presentation. Ishikawa's criteria (1988) has been widely used for the diagnosis of this disease. Few modifications have been proposed in Ishikawa's criteria for the diagnosis of TA. The proposed modifications include: (a) removal of the obligatory criteria of age less than 40 years; (b) inclusion of characteristic signs and symptoms as a major criteria; (c) removal of age in defining hypertension; (d) deletion of the absence of aorto-iliac lesion, in defining abdominal aortic lesion; and (e) an addition of coronary artery lesion in absence of risk factors. The criteria proposed consists of three major criteria including left and right mid subclavian artery lesions and characteristic signs and symptoms of at least one month duration and ten minor criteria-a high erythrocyte sedimentation rate, carotid artery tenderness, hypertension, aortic regurgitation or annuloaortic ectasia, pulmonary artery lesion, left mid common carotid lesion, distal brachiocephalic trunk lesion, descending thoracic aorta lesion, abdominal aorta lesion and coronary artery lesion. Presence of two major or one major and two minor criteria or four minor criteria suggests a high probability of TA. When applied to 106 Indian patients of angiographically proven TA and 20 control subjects, it had a sensitivity of 92.5% and specificity of 95% that was higher than that of Ishikawa's criteria (sensitivity 60.4%, specificity 95%) and American college of Rheumatology criteria (sensitivity 77.4%, specificity 95%). Similarly, this criteria had a 96% sensitivity and 96% specificity in 79 Japanese patients of TA and 79 control subjects. Adoption of these criteria is expected to prevent the possibility of an under diagnosis of TA.

A precision measurement of the mass of the top quark

The standard model of particle physics contains parameters--such as particle masses--whose origins are still unknown and which cannot be predicted, but whose values are constrained through their interactions. In particular, the masses of the top quark (M(t)) and W boson (M(W)) constrain the mass of the long-hypothesized, but thus far not observed, Higgs boson. A precise measurement of M(t) can therefore indicate where to look for the Higgs, and indeed whether the hypothesis of a standard model Higgs is consistent with experimental data. As top quarks are produced in pairs and decay in only about 10(-24) s into various final states, reconstructing their masses from their decay products is very challenging. Here we report a technique that extracts more information from each top-quark event and yields a greatly improved precision (of +/- 5.3 GeV/c2) when compared to previous measurements. When our new result is combined with our published measurement in a complementary decay mode and with the only other measurements available, the new world average for M(t) becomes 178.0 +/- 4.3 GeV/c2. As a result, the most likely Higgs mass increases from the experimentally excluded value of 96 to 117 GeV/c2, which is beyond current experimental sensitivity. The upper limit on the Higgs mass at the 95% confidence level is raised from 219 to 251 GeV/c2.

Polysaccharides for Colon Targeted Drug Delivery

Colon targeted drug delivery has the potential to deliver bioactive agents for the treatment of a variety of colonic diseases and to deliver proteins and peptides to the colon for their systemic absorption. Various strategies, currently available to target the release of drugs to colon, include formation of prodrug, coating of pH-sensitive polymers, use of colon-specific biodegradable polymers, timed released systems, osmotic systems, and pressure controlled drug delivery systems. Among the different approaches to achieve targeted drug release to the colon, the use of polymers especially biodegradable by colonic bacteria holds great promise. Polysaccharidases are bacterial enzymes that are available in sufficient quantity to be exploited in colon targeting of drugs. Based on this approach, various polysaccharides have been investigated for colon-specific drug release. These polysaccharides include pectin, guar gum, amylose, inulin, dextran, chitosan, and chondroitin sulphate. This family of natural polymers has an appeal to drug delivery as it is comprised of polymers with a large number of derivatizable groups, a wide range of molecular weights, varying chemical compositions, and, for the most part, low toxicity and biodegradability yet high stability. The most favorable property of these materials is their approval as pharmaceutical excipients.

Percutaneous treatment of liver abscesses: needle aspiration versus catheter drainage

OBJECTIVE

This study was designed to determine and compare the efficacy of sonographically guided percutaneous needle aspiration and percutaneous catheter drainage in the treatment of liver abscesses.

SUBJECTS AND METHODS

In a randomized study, 50 patients (38 males and 12 females; age range, 2-72 years; average age, 35 years) with liver abscesses (amebic, 20; pyogenic, 11; indeterminate, 19) underwent either percutaneous needle aspiration (n = 25) or catheter drainage (n = 25) along with appropriate antimicrobial therapy. In patients assigned to the needle aspiration group, an 18-gauge needle was used to aspirate the abscess cavity. Repeated aspiration was attempted only once in each patient not responding to the first aspiration; nonresponse to the second aspiration was considered failure of treatment, and these patients were given catheter drainage (however, these patients were not included in the catheter drainage group). For catheter drainage, 8- to 12-French catheters were introduced into the abscess cavity using the Seldinger technique. In patients with multiple abscesses (seven in aspiration group and five in catheter group), all the abscesses except those smaller than 3 cm were subjected to percutaneous treatment. Patients were followed up to assess the outcome of the percutaneous treatment, length of hospital stay, and development of any complications. Sonography was performed every third day during hospitalization. After discharge of the patient, periodic clinical and sonographic examinations were done until total resolution of abscesses was achieved.

RESULTS

Although percutaneous needle aspiration was successful in only 15 (60%) of the 25 patients after one (n = 11) or two (n = 4) aspirations, catheter drainage was curative in all 25 patients (100%) (p < .05). Among the successfully treated patients, the average time for clinical improvement and the mean hospital stay were similar in the two treatment groups. Although the average time needed for a 50% reduction in the size of the abscess cavity was significantly (p < .05) greater in the aspiration group than in the catheter group (11 days versus 5 days), the average time taken for total resolution of abscess was the same (15 weeks) in both groups. No major complications were encountered. No relapse was documented on clinical and sonographic examination during follow-up, which ranged from 8 to 37 weeks.

CONCLUSION

Our results show that percutaneous catheter drainage is more effective than needle aspiration in the treatment of liver abscesses. Needle aspiration, if limited to two attempts, has a high failure rate.

UK Consensus on Normal Tissue Dose Constraints for Stereotactic Radiotherapy

Six UK studies investigating stereotactic ablative radiotherapy (SABR) are currently open. Many of these involve the treatment of oligometastatic disease at different locations in the body. Members of all the trial management groups collaborated to generate a consensus document on appropriate organ at risk dose constraints. Values from existing but older reviews were updated using data from current studies. It is hoped that this unified approach will facilitate standardised implementation of SABR across the UK and will allow meaningful toxicity comparisons between SABR studies and internationally.

Structure of human beta-glucuronidase reveals candidate lysosomal targeting and active-site motifs

The X-ray structure of the homotetrameric lysosomal acid hydrolase, human beta-glucuronidase (332,000 Mr), has been determined at 2.6 A resolution. The tetramer has approximate dihedral symmetry and each promoter consists of three structural domains with topologies similar to a jelly roll barrel, an immunoglobulin constant domain and a TIM barrel respectively. Residues 179-204 form a beta-hairpin motif similar to the putative lysosomal targeting motif of cathepsin D, supporting the view that lysosomal targeting has a structural basis. The active site of the enzyme is formed from a large cleft at the interface of two monomers. Residues Glu 451 and Glu 540 are proposed to be important for catalysis. The structure establishes a framework for understanding mutations that lead to the human genetic disease mucopolysaccharidosis VII, and for using the enzyme in anti-cancer therapy.

Late results of the Royal Free Hospital prospective controlled trial of prednisolone therapy in hepatitis B surface antigen negative chronic active hepatitis

A long-term follow-up of at least 10 years or until death of 44 patients taking part in a controlled prospective trial of prednisolone therapy in hepatitis B antigen negative chronic active hepatitis (lupoid hepatitis) has been performed at the Royal Free Hospital, London. Patients presenting between 1963 and 1967 were randomly allocated into control and treatment groups. Ten year life table survival curves showed a significantly improved survival in the treatment group where 63% of patients were alive at 10 years compared with only 27% in the control group (log rank test, P = 0.03). The median survival in the treatment group was 12.2 years compared with 3.3 years in the control group. The mean duration of treatment was 4.5 years. Age, presence of antinuclear factor, cirrhosis, or level of serum transaminases at presentation did not appear to affect survival. Male patients if untreated had a poorer prognosis than females (P = 0.02). The natural history of chronic active hepatitis appeared from clinical, biochemical, and histological findings to be from an active hepatitis or cirrhosis to inactive macronodular cirrhosis. Prednisolone therapy significantly improved survival by reducing mortality in the early active phase of the disease.

Desmoplastic malignant melanoma and its variants. A study of 45 cases

Forty-five tumors exhibiting the histological features of desmoplastic malignant melanoma or its variant, neurotropic melanoma, were found among approximately 4,500 soft-tissue tumors referred in consultation from Australia and New Zealand. All patients were Caucasians. Tumors fell into three groups: (a) desmoplastic melanoma with an atypical intra-epidermal melanocytic component (classical desmoplastic melanoma) (12 cases); (b) desmoplastic melanoma without an atypical intra-epidermal melanocytic component (de novo desmoplastic melanoma) (21 cases); (c) predominantly nerve-centered superficial malignant tumors with or without an atypical intra-epidermal melanocytic component (12 cases). Three of the nerve-centered tumors were associated with pigmentary abnormalities in the overlying skin. The patients' ages ranged from 42 to 91 years, with a peak in the seventh decade; 31 patients were male and 14 were female. Lesions were located in the head and neck (35 cases), shoulder and arm (four), back and chest (three), abdomen (one), thigh (one), and leg (one). Three tumors arose in irradiated areas, and one occurred on the face of a radiotherapist. Melanin was found in only four tumors, but the S-100 protein stain was positive in 19 tumors and negative in three. Follow-up details of 42 patients were available. In follow-up times from 4 months to 15 years (mean, 4.6 years), 15 patients (36%) had died of the disease or were terminally ill; 24 (57%) were alive with no apparent residual tumor; and three (7%) had died of other causes. Twenty-three patients (55%) developed one or more local recurrences; 17 (40%) developed distant spread, including extension into the cranial cavity along nerves; and 14 (33%) had both local recurrence and distal spread. Nine (82%) of 11 patients with nerve-centered tumors died or were terminally ill. The usual treatment was surgical. Most uncontrolled recurrences were resistant to chemotherapy and radiotherapy; however, two patients responded well, one to chemotherapy and one to radiotherapy. Our observation support Reed and Leonard's metaplastic explanation for the varied differentiation seen in desmoplastic melanomas.

Evaluation of cytotoxicity and radiation enhancement using 1.9 nm gold particles: potential application for cancer therapy

High atomic number (Z) materials such as gold preferentially absorb kilovoltage x-rays compared to soft tissue and may be used to achieve local dose enhancement in tumours during treatment with ionizing radiation. Gold nanoparticles have been demonstrated as radiation dose enhancing agents in vivo and in vitro. In the present study, we used multiple endpoints to characterize the cellular cytotoxic response of a range of cell lines to 1.9 nm gold particles and measured dose modifying effects following transient exposure at low concentrations. Gold nanoparticles caused significant levels of cell type specific cytotoxicity, apoptosis and increased oxidative stress. When used as dose modifying agents, dose enhancement factors varied between the cell lines investigated with the highest enhancement being 1.9 in AGO-1522B cells at a nanoparticle concentration of 100 microg ml(-1). This study shows exposure to 1.9 nm gold particles to induce a range of cell line specific responses including decreased clonogenic survival, increased apoptosis and induction of DNA damage which may be mediated through the production of reactive oxygen species. This is the first study involving 1.9 nm nanometre sized particles to report multiple cellular responses which impact on the radiation dose modifying effect. The findings highlight the need for extensive characterization of responses to gold nanoparticles when assessing dose enhancing potential in cancer therapy.

Evidence for membrane lipid peroxidation during the in vivo aging of human erythrocytes

This study has examined the occurrence of lipid peroxidation in in vivo aged human erythrocyte membranes. Erythrocytes of various ages were separated on discontinuous stractan density gradients. Three erythrocyte fractions were analyzed: (I) Light--erythrocytes staying between stractan densities 1.053 and 1.043 g/ml, (II) predensest--erythrocytes staying between stractan densities 1.081 and 1.111, and (III) densest--erythrocytes passing stractan density 1.111. Peroxidative lipid damage of erythrocytes was assessed by measuring lipid extract fluorescence, by lipid thin-layer chromatography for the presence of adduct of phosphatidylserine (PS), phosphatidylethanolamine (PE) and malondialdehyde, and by thiobarbituric acid-reactivity. Fractions I, II and III contained, respectively, 0.2 +/- 0.1 (S.E.), 1.1 +/- 0.1 and 1.5 +/- 0.1 of phospholipid-malondialdehyde adduct (percent of total phospholipids), and relative lipid fluorescence 22.5 +/- 0.8, 29.3 +/- 0.5, and 33.4 +/- 0.8 per ml packed cells, respectively. Thiobarbituric acid-reactivity of erythrocytes in various fractions was similar. Untreated densest erythrocytes contained significantly reduced PS (12.9 +/- 0.5%), in contrast to light erythrocytes (16.1 +/- 0.1%) and increased PC (31.2 +/- 0.3 versus 27.8 +/- 0.8% of the total phospholipid). This study provides evidence for significant lipid peroxidative damage in the erythrocyte membrane during aging in vivo.

Success of monovision in presbyopes: review of the literature and potential applications to refractive surgery

The monovision concept of correcting one eye for distance and the other for near may be utilized in presbyopes undergoing refractive surgery. We have performed a systematic review of published literature to evaluate the factors influencing monovision success, and to determine the visual outcome in patients with monovision. Articles in MEDLINE and published bibliographies reporting monovision prescription for correction of presbyopia were systematically identified and reviewed. Pertinent data were abstracted and, when feasible, statistically analyzed. The mean success rate was 73%. The success in monovision correlated with distance correction on dominant eye, alternating dominance, less than 50 seconds of are stereoacuity reduction, and less than 0.6 prism diopter of distance esophoric shifts. Monovision resulted in significant reduction of binocular contrast sensitivity function at spatial frequencies higher than 4 cycles per degree, and 2-6% reduction in task performance, but resulted in minimal reduction of binocular visual acuity, peripheral vision, visual field width and binocular depth of focus. The published literature indicates that monovision is an effective and reasonable therapeutic modality for correcting presbyopia. Proper patient selection and clinical screening are essential for monovision success.