Wearable embroidered muscle activity sensing device for the human upper leg

Within the last decade, running has become one of the most popular physical activities in the world. Although the benefits of running are numerous, there is a risk of Running Related Injuries (RRIs) of the lower extremities. Electromyography (EMG) techniques have previously been used to study causes of RRIs, but the complexity of this technology limits its use to a laboratory setting. As running is primarily an outdoors activity, this lack of technology acts as a barrier to the study of RRIs in natural environments. This study presents a minimally invasive wearable muscle sensing device consisting of jogging leggings with embroidered surface EMG (sEMG) electrodes capable of recording muscle activity data of the quadriceps group. To test the use of the device, a proof of concept study consisting of N = 2 runners performing a set of 5 km running trials is presented in which the effect of running surfaces on muscle fatigue, a potential cause of RRIs, is evaluated. Results show that muscle fatigue can be analysed from the sEMG data obtained through the wearable device, and that running on soft surfaces (such as sand) may increase the likelihood of suffering from RRIs.

Abstract P2-05-07: Comparison of the Xpert breast cancer stratifier mRNA assay with central ER, PR, HER2, and Ki67 immunohistochemistry (IHC) for rapid biomarker analysis in developing countries

Breast cancer care in the developing world is limited by access to quality ER and HER2 IHC diagnostic assays needed to justify hormone and HER2 therapeutics. Shipping pathology specimens to a central testing site often out of country delays therapy and is costly. The Xpert Breast Cancer Stratifier assay makes quantitative measurements of ESR1, PGR, ERBB2, and MKi67 mRNAs from FFPE specimens in <2 hours on an easy-to-use automated diagnostic platform, the GeneXpert (GX). 10,000 GX machines are currently in use in 182 countries offering the possibility of a point-of-care solution. We compared concordance in tumor samples between IHC and mRNA intending to challenge the limits of the GX mRNA assay.

83 breast tumor samples were chosen including those with low cellularity, small volume disease, unusual subtypes, ER- tumors with surrounding benign epithelium, and low level HER2+ tumors. mRNA, IHC and FISH assays were performed. Slides were tested following macrodissection of invasive carcinoma and as non-macrodissected whole sections. GX measurements for Ki67 were compared with mitotic rate as an alternative to Ki67 IHC.

Overall percent agreement following macrodissection was 95% for ER, 89% for HER2, 76% for PR, and 80% for Ki67 (>20% positive cut), and using whole section, 99% for ER, 80% for PR, 92% for HER2, and 73% for Ki67. Concordance was 92% for both macrodissection and whole section using mitotic rate to assess proliferation. Ignoring HER2 2+ calls which represented low level amplified tumors by FISH, the concordance rates were 95% for macrodissection and 99% for whole section. Discordance when testing long-term stored 4μm sections was resolved in a number of cases by using a fresh cut from the FFPE block. Half the ER discrepancies were in very small volume tumors ≤25mm2 and 75% were classified as ER-ve by IHC, and positive by Stratifier. 80% of ER IHC- cases were appropriately identified as ER- by the Stratifier in the presence of benign breast epithelium. HER2+ DCIS adjacent to HER2- invasive tumor resulted in a discrepant HER2 mRNA result even with macrodissection. No ER or HER2 discrepancies occurred in low cellularity tumors (≤30% cellularity) nor in lobular and mucinous subtypes.

In a study intended to challenge an mRNA breast biomarker assay, concordance between mRNA results and IHC was high for ER and HER2, the two most important prognostic markers needed for therapeutic decision making. Use of whole sections rather than tumor macrodissection did not decrease concordance. Discrepant ER cases were more prevalent when analyzing low volumes of tumor and in this setting were seen in ER IHC- tumors surrounded by ER+ normal epithelium, or with weak IHC expression, highlighting predictable limitations of the assay. Concordance was better between Ki67 mRNA and mitotic rate than with IHC. Re-test data suggested that a fresh cut of the FFPE block yields the best results by GX, perhaps due to mRNA degradation in stored 4μm sections. The Xpert Breast Cancer Stratifier may provide a rapid, cost-effective solution to the problem of obtaining accurate diagnostic results at the point-of-care in low resource settings, and deserves further evaluation in developing countries.

Citation Format: Brock JE, Milner DA, Ho K, Natalie W, Victor C, Annaliza R, Teresa B, Kathryn G-F, Edwin LW, Jodi W, Wendy W, Michael B. Comparison of the Xpert breast cancer stratifier mRNA assay with central ER, PR, HER2, and Ki67 immunohistochemistry (IHC) for rapid biomarker analysis in developing countries [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P2-05-07.

Critical and honest conversations: the evidence behind the "Choosing Wisely" campaign recommendations by the American Society of Nephrology

Estimates suggest that one third of United States health care spending results from overuse or misuse of tests, procedures, and therapies. The American Board of Internal Medicine Foundation, in partnership with Consumer Reports, initiated the "Choosing Wisely" campaign to identify areas in patient care and resource use most open to improvement. Nine subspecialty organizations joined the campaign; each organization identified five tests, procedures, or therapies that are overused, are misused, or could potentially lead to harm or unnecessary health care spending. Each of the American Society of Nephrology's (ASN's) 10 advisory groups submitted recommendations for inclusion. The ASN Quality and Patient Safety Task Force selected five recommendations based on relevance and importance to individuals with kidney disease.Recommendations selected were: (1) Do not perform routine cancer screening for dialysis patients with limited life expectancies without signs or symptoms; (2) do not administer erythropoiesis-stimulating agents to CKD patients with hemoglobin levels ≥10 g/dl without symptoms of anemia; (3) avoid nonsteroidal anti-inflammatory drugs in individuals with hypertension, heart failure, or CKD of all causes, including diabetes; (4) do not place peripherally inserted central catheters in stage 3-5 CKD patients without consulting nephrology; (5) do not initiate chronic dialysis without ensuring a shared decision-making process between patients, their families, and their physicians.These five recommendations and supporting evidence give providers information to facilitate prudent care decisions and empower patients to actively participate in critical, honest conversations about their care, potentially reducing unnecessary health care spending and preventing harm.

Breeding patterns of the JE vector Culex gelidus and its insect predators in rice cultivation areas of northern peninsular Malaysia

Japanese encephalitis (JE) virus activity is an important cause of viral encephalitis in Southeast Asia. In Malaysia, JEV activity has been first detected in Culex gelidus in 1976. Since then, no study has fully addressed the seasonal dynamics of this mosquito. As irrigated rice production expands, the incidence of JEV vectors, particularly Cx. gelidus is expected to increase. We surveyed Penang Island to determine the breeding patterns of Cx. gelidus and their potential insect predators, in relation to habitat/niche and rice growing period. Six rice fields proper (RFP) and related drainage canals (DC) were visited through three cultivation cycles (CCs) over 17 months. Weekly visits were performed to each of the 36 sites and mosquito larvae and aquatic insects were sampled from RFP and DCs using dippers. Culex gelidus was abundant in RFP and almost absent in DCs. Its densities usually were high during the first and 3rd CC and when the RFs were in Fp, Pp and Gp. In DCs, the mosquito was abundant during Mp, e.g., 2nd CC. Predators, especially those belonging to the families Corixidae, Coenagrionidae and Dytiscidae, were more present in RFP. Predator numbers usually were high during the first CC; in some cases predator abundance peaked during other CCs, e.g., corixids and dysticids. In RFP, neither corixids nor coenagrionids showed any positive correlation with densities of Cx. gelidus. However, dytiscids' population peaked when the mosquito densities were on the rise. These observations suggest that Cx. gelidus is active during the period of rice cultivation. Operational vector control through bio-control or with insecticides near the end of the rice cultivation season in RFP may prove beneficial in reducing the density of Cx. gelidus, but also the amount of bio-agent or insecticide applied on riceland.

Clobazam as an add-on in the management of refractory epilepsy

BACKGROUND

Epilepsy effects approximately 1% of the population, with up to 30% of patients continuing to have seizures despite antiepileptic drug treatment.

OBJECTIVES

To assess the efficacy and tolerability of clobazam when used as an add-on therapy for patients with refractory partial onset or generalised onset seizures.

SEARCH STRATEGY

We searched the following on 22nd March 2007: (a) The Cochrane Epilepsy Group Specialised Register; (b) The Cochrane Central Register of Controlled Trials (CENTRAL); (c) MEDLINE; (d) EMBASE; (e) Database of Abstracts of Reviews of Effectiveness (DARE); (f) American College of Physicians Journals; (g) BIOSIS.

SELECTION CRITERIA

Randomised trials of add-on clobazam, with adequate methods of allocation concealment, recruiting patients with drug refractory partial or generalised onset seizures, with a minimum treatment period of eight weeks.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected trials for inclusion and extracted relevant data. The following outcomes were assessed: 50% or greater reduction in seizures; seizure freedom; treatment withdrawal and adverse effects.

MAIN RESULTS

Four cross-over studies, representing 196 participants, were included. However, due to significant methodological heterogeneity and differences in outcome measures it was not possible to summarise data in a meta-analysis. Only two of the studies reported a 50% or greater seizure reduction compared to placebo; 57.7% and 52.4%. Side effects were only described in two of the studies, reportedly present in 36% and 85% of patients.

AUTHORS' CONCLUSIONS

Clobazam as an add-on treatment may reduce seizure frequency and may be most effective in partial onset seizures. However, it is not clear who will best benefit and over what time-frame. A large scale, randomised controlled trial conducted over a greater period of time, incorporating subgroups with differing seizure types, is required to inform clinical practice.

Postprocedural Aspiration Test to Predict Adequacy of Dialysis Following Tunneled Catheter Placement

The objective of the study was to determine if a timed aspiration technique with a 20-ml syringe can be used to predict adequacy of blood flow in tunneled dialysis catheters. Sixteen patients referred for de novo placement or manipulation of failing tunneled hemodialysis catheters had the time it takes to fill a 20-ml syringe with the plunger fully withdrawn measured to the nearest tenth of a second. These measurements were correlated with flow rates recorded in dialysis just prior to (if failed catheter) and in the following dialysis session with adequacy determined as at least 300 ml/min. Syringe-filling time (22 catheters in 16 patients) was plotted against adequacy of dialysis. The mean time to fill a 20-ml syringe was 2.2 sec, with a range of 1.0-4.7 sec. The mean time to fill syringes for catheters with adequate dialysis was 1.7 +/- 0.5 sec, and for inadequate catheters, it was 2.8 +/- 0.8 sec. These differences are statistically significant (p < 0.001). Using a filling time of greater than or equal to 2 sec as a threshold gives the highest sensitivity (100%) for predicting inadequate dialysis while maintaining high specificity (75%). To achieve a specificity of 100%, a 3-sec cutoff would be necessary, but would lead to a sensitivity of only 20%. A simple and objective aspiration technique can be performed at the time of tunneled dialysis catheter placement/manipulation to reasonably predict adequacy of subsequent dialysis.

Drug Insight: safety of intravenous iron supplementation with sodium ferric gluconate complex

Intravenous iron is necessary for optimal management of anemia in patients receiving hemodialysis and is utilized in the majority of these patients in the US. The availability of nondextran formulations of intravenous iron has significantly improved the safety of its use. The nondextran iron formulation sodium ferric gluconate complex (SFGC) has been extensively studied in the hemodialysis population, with two large phase IV trials documenting its safety. SFGC is efficacious and, at recommended doses, is associated with a low incidence of adverse events. There have been few comparative studies of the nondextran intravenous iron preparations; however, they are known to have different pharmacokinetic characteristics. There is also evidence to indicate that these compounds differ in terms of their cytotoxic and proinflammatory properties, and their propensity to induce oxidative stress. This paper reviews the current literature on the safety of SFGC and examines the emerging safety issues surrounding the use of intravenous iron.

Time-dependent associations between iron and mortality in hemodialysis patients

The independent association between the indices of iron stores or administered intravenous iron, both of which vary over time, and survival in patients who are on maintenance hemodialysis (MHD) is not clear. It was hypothesized that the observed associations between moderately high levels of three iron markers (serum ferritin, iron, and iron saturation ratio) or administered intravenous iron and all-cause and cardiovascular death is due to the time-varying confounding effect of malnutrition-inflammation-cachexia syndrome (MICS). Time-dependent Cox regression models were examined using prospectively collected data of the 2-yr (July 2001 to June 2003) historical cohort of 58,058 MHD patients from virtually all DaVita dialysis clinics in the United States. After time-dependent and multivariate adjustment for case mix, administered intravenous iron and erythropoietin doses, and available surrogates of MICS, serum ferritin levels between 200 and 1200 ng/ml (reference 100 to 199 ng/ml), serum iron levels between 60 and 120 microg/ml (reference 50 to 59 microg/ml), and iron saturation ratio between 30 and 50% (reference 45 to 50%) were associated with the lowest all-cause and cardiovascular death risks. Compared with those who did not receive intravenous iron, administered intravenous iron up to 400 mg/mo was associated with improved survival, whereas doses >400 mg/mo tended to be associated with higher death rates. The association between serum ferritin levels >800 ng/ml and mortality in MHD patients seems to be due mostly to the confounding effects of MICS. For ascertaining whether the observed associations between moderate doses of administered intravenous iron and improved survival are causal or due to selection bias by indication, clinical trials are warranted.

Sodium ferric gluconate complex in haemodialysis patients: a prospective evaluation of long-term safety

BACKGROUND

A previous single dose placebo-controlled double-blinded trial showed an extremely low (0.4%) intolerance rate of sodium ferric gluconate complex (SFGC) in SFGC-naive haemodialysis patients. No large prospective trials have assessed the safety of SFGC during repeated exposure in the outpatient haemodialysis setting.

METHODS

Chronic haemodialysis patients completing the single-dose trial of SFGC were eligible to participate in this prospective, multicentre, open-label, long-term evaluation of SFGC, designed to record adverse events occurring up to 72 h post-dose. Patients received as many as 20 ampules (1250 mg total) of SFGC at an investigator-determined dose and rate over a 9 month evaluation period.

RESULTS

Among 1412 enrolled patients at 54 centres, 1321 received 13,151 infusions of SFGC. Most doses (94.8%) were < or =125 mg and the majority were given over 10 min. Infusion rates ranged from <5 to 125 mg/min. There were no life-threatening events. Fifty-one patients (3.9%) experienced an adverse event, possibly related to SFGC. Of these, one experienced a serious event (hypotension). Five patients (0.4%) experienced an event that precluded SFGC readministration: pruritus (three), vasodilatation (one) and loss of taste (one). Among 372 patients (28.2%) receiving angiotensin-converting enzyme inhibitor (ACEI) therapy, adverse events were neither more common nor more severe than in the other patients.

CONCLUSIONS

Repeated doses of SFGC are very well tolerated in haemodialysis patients. No life-threatening events were observed in over 13,000 doses administered. Administration of SFGC to patients using ACEI is safe and does not increase the incidence or severity of adverse events to SFGC.

Chronic use of sodium ferric gluconate complex in hemodialysis patients: safety of higher-dose (> or =250 mg) administration

BACKGROUND

Almost all hemodialysis (HD) patients require intravenous iron therapy to correct their anemia and maintain their iron stores. Sodium ferric gluconate complex (SFGC) is approved by the Food and Drug Administration (FDA) for treatment of iron deficiency anemia in HD patients at individual doses up to 125 mg over 10 minutes (12.5 mg/min) and has been shown to have a superior safety profile compared with iron-dextran. Higher individual doses of SFGC would permit more rapid repletion of iron stores and greater flexibility in maintenance iron therapy as well as simplify treatment of peritoneal dialysis patients and chronic kidney disease patients.

METHODS

The authors reviewed the safety and tolerability of higher-dose SFGC infusions (> or =250 mg) in 144 HD patients who were previously tolerant to a single 125-mg dose of SFGC. These 144 patients received a total of 590 doses of > or =250 mg of SFGC; 571 doses were 250 mg SFGC, and most of these were infused over 1 hour, an infusion rate of 4.17 mg/min. The other 19 doses were 312.5 mg (n = 1), 375 mg (n = 14), and 500 mg (n = 4). Infusion rates varied from 1.22 mg/min to 25.0 mg/min.

RESULTS

Only one patient was considered intolerant to higher-dosing SFGC after having pruritus after a second 250-mg dose of SFGC. Three patients had nonserious events that did not preclude further dosing of SFGC.

CONCLUSION

Administration of 250 mg SFGC over 1 hour is safe and well tolerated. Individual doses of 375 mg and 500 mg SFGC also were well tolerated, but further research and experience are needed to confirm the safety and tolerance of these doses.

Sodium ferric gluconate complex in hemodialysis patients. II. Adverse reactions in iron dextran-sensitive and dextran-tolerant patients

BACKGROUND

Iron dextran administration is associated with a high incidence of adverse reactions including anaphylaxis and death. Although dextran, rather than iron, is believed to be the cause of these reactions, it is not known whether iron dextran-sensitive patients can be safely administered another form of parenteral iron, sodium ferric gluconate in sucrose (SFGC).

METHODS

In a 69 center, prospective, double-blind, controlled trial of safety and tolerability of SFGC, the rate of reactions to SFGC and placebo in 144 iron dextran-sensitive patients was compared with 2194 patients who were previously tolerant to iron dextran preparations. Serum tryptase levels, a marker of mast cell degranulation, also were measured.

RESULTS

Among 143 iron dextran-sensitive patients exposed to SFGC, three (2.1%) were intolerant. All three had suspected allergic events to SFGC, including one patient with a serious reaction (0.7%). One dextran-sensitive patient (0.7%) had a suspected allergic reaction after placebo. In contrast, among 2194 iron dextran-tolerant patients, reactions to SFGC were significantly less common, with SFGC intolerance seen in seven patients (0.3%; P = 0.020), including five (0.2%) who had suspected allergic events (P = 0.010), but none who had serious events (0.0%; P = 0.061). Two iron dextran-tolerant patients (0.09%) had allergic-like reactions following placebo injections. Two of the three suspected allergic events in the iron dextran-sensitive group were confirmed as mast cell dependent by a 100% increase in serum tryptase, while there were no confirmed allergic events in the iron dextran-tolerant group. Long-term exposure to SFGC in iron dextran-sensitive patients resulted in intolerance in only one additional patient and no serious adverse events.

CONCLUSIONS

Patients with a history of iron dextran sensitivity had approximately sevenfold higher rates of reaction to both placebo and SFGC compared to iron dextran tolerant patients. However, logistic regression analysis, performed to account for the higher reaction rate to placebo, suggests that this increased reactivity was not drug-specific nor immunologically mediated, but represented host idiosyncrasy. These results support the conclusions that reactions to SFGC can be attributed to pseudoallergy, and that SFGC is not a true allergen.

Development of an HCV infection risk stratification algorithm for patients on chronic hemodialysis

OBJECTIVE

The prevalence of hepatitis C virus (HCV) in patients on chronic hemodialysis (HD) is near 9%. Transaminases, which are lower in HD patients, are not effective in screening for HCV. Our aim was to design an HCV risk stratification strategy incorporating lowered aminotransferase levels and other clinical parameters.

METHODS

Patient serum from 168 consecutive HD patients was analyzed for AST, ALT, ferritin, and hepatitis C antibody. Sensitivity, specificity, positive predictive value, and negative predictive value were calculated for lower transaminase values. Multivariate classification and regression tree analysis was used to determine the best combination of variables to predict risk for HCV infection.

RESULTS

Median AST and ALT levels were higher in anti-HCV Ab(+) patients (p < 0.05). Applying a lower cutoff value for ALT of 16 IU/L resulted in a sensitivity of 61.1%, a specificity of 66.7%, a positive predictive value of 33.9%, and a negative predictive value of 86.0% for detection of HCV infection. Multivariate classification and regression tree analysis derived an algorithm using patient age, months on HD, and AST, resulting in a 97.2% sensitivity and a 51.9% specificity for the detection of HCV(+) HD patients.

CONCLUSIONS

A lower normal cutoff value of 18 IU/L for AST and 16 IU/L for ALT increased sensitivity and specificity for the detection of HCV infection in HD patients. An algorithm combining lower transaminases with clinical parameters improved both sensitivity and specificity in HCV detection. Prospective confirmation of this algorithm would allow more selective HCV enzyme immunoassay and polymerase chain reaction testing in dialysis units.

Sodium ferric gluconate complex in hemodialysis patients: adverse reactions compared to placebo and iron dextran

BACKGROUND

Parenteral iron is often required by hemodialysis patients to maintain adequate iron stores. Until recently, the only available form of intravenous iron was iron dextran, which is associated with significant adverse reactions, including anaphylaxis and death. Sodium ferric gluconate complex (SFGC) was recently approved for use in the U.S. under FDA's priority drug review. This Phase IV study was designed to evaluate the safety of a single dose of intravenous SFGC as compared to placebo and a historical iron dextran control.

METHODS

This multicenter, crossover, randomized, double blind, placebo-controlled prospective comparative study was performed in hemodialysis patients requiring at least 125 mg of elemental iron. The historical control was obtained from a meta-analysis of four publications examining outcomes in patients exposed to iron dextran. SFGC naïve patients were administered SFGC without a test dose, undiluted, at a rate of 125 mg over 10 minutes, and compared to placebo comprising bacteriostatic saline.

RESULTS

A total of 2534 patients were enrolled. The incidence of drug intolerance (an adverse event precluding re-exposure) was significantly less [0.44%, confidence interval (CI) 0.21 to 0.71%] after SFGC as compared to the iron dextran control (2.47%, CI 1.87 to 3.07%, P < 0.0001), but higher than after placebo (0.1%, P = 0.02). There was no difference found between SFGC and placebo in serious adverse events. A single life-threatening event occurred after SFGC (0.04%, CI 0.00 to 0.22%), which was significantly less than following iron dextran (0.61%, CI 0.36 to 0.86%), P = 0.0001.

CONCLUSION

SFGC is well tolerated when given by intravenous push without a test dose. SFGC has a significantly lower incidence of drug intolerance and life-threatening events as compared to previous studies using iron dextran. The routine use of iron dextran in hemodialysis patients should be discontinued.

Titration of subcutaneously administered eprinomectin against mature and immature nematodes in cattle

Eprinomectin has been approved for use as a topically applied endectocide for beef and dairy cattle. To determine if eprinomectin has utility as an injectable anthelmintic, it was titrated at 0.05, 0.1, and 0.2 mg/kg s.c. against adult (Trial 1) and at 0.05, 0.1, 0.14, and 0.2 mg/kg s.c. against immature (Trial 2) stages of lung and gastrointestinal nematodes in cattle. In Trial 1, every dose of subcutaneously delivered eprinomectin showed maximal or near-maximal (> or = 99%) efficacy against Haemonchus placei, Ostertagia ostertagi, Trichostrongylus axei, T colubriformis, Cooperia punctata, Nematodirus helvetianus, Oesophagostomum radiatum, and Dictyocaulus viviparus. Adult C. oncophora was the only exception. However, even against this species, the lowest dose of 0.05 mg/kg showed 93% efficacy, and the efficacious dose necessary to kill 95% (ED95) of adults was 0.056 mg/kg. In Trial 2, every dose of subcutaneously delivered eprinomectin showed maximal or near-maximal (> or = 99%) efficacy against the immature stages of all of the above species of endoparasites. As a result, ED95 values could not be calculated. Consequently, the exquisite potency against endoparasites through parenteral administration suggests that eprinomectin may also have potential utility as an injectable product for cattle.

SdiA of Salmonella enterica is a LuxR homolog that detects mixed microbial communities

Proteins of the LuxR family detect the presence of N-acylhomoserine lactones (AHLs) and regulate transcription accordingly. When AHLs are synthesized by the same species that detects them, the system allows a bacterium to measure the population density of its own species, a phenomenon known as quorum sensing. The sdiA genes of Escherichia coli and Salmonella enterica serovar Typhimurium are predicted to encode LuxR homologs. However, these species do not appear to synthesize AHLs or any other molecule detected by SdiA. It has previously been demonstrated that overexpression of sdiA results in the activation of the ftsQAZ locus in E. coli and four other loci in Salmonella serovar Typhimurium. Here we report that transcriptional fusions to these five loci fall into two classes. The first class requires overexpression of sdiA for activation. The second class responds to sdiA expressed from its natural position in the chromosome if the appropriate AHLs are added to the culture. The only member of the second class is a series of Prck-luxCDABE fusions in Salmonella serovar Typhimurium. SdiA responds with highest sensitivity to AHLs that have a keto modification at the third carbon and an acyl chain length of 6 or 8 (half-maximal response between 1 and 5 nM). Growth of Salmonella in proximity to species known to synthesize these AHLs results in sdiA-dependent activation of the Prck-luxCDABE fusions. SdiA appears to be the first AHL receptor discovered that detects signals emanating exclusively from other species.

Comparison of ivermectin, doramectin, selamectin, and eleven intermediates in a nematode larval development assay

Chemical substitutions at pharmacologically relevant sites such as C-5, C-13, C-22,23, and C-25 were examined in ivermectin, doramectin, selamectin, and a series of 11 other intermediates using a larval development assay with Haemonchus contortus. A range of activities spanning 5 orders of magnitude were manifest with small changes in the substituents to the 14 avermectins. Within this compound series, there was no major potency advantage or disadvantage to a disaccharide over a monosaccharide substituent at C-13. Ivermectin and doramectin were each fully effective at a concentration of 0.001 microg/ml, and both were similar to their respective monosaccharide homologs. Specific patterns emerged among the analogs with substituents at C-5. Analogs possessing hydroxyl groups at C-5 were superior in activity by several orders of magnitude over those with oxo substituents. Replacement of the oxo with an oxime (NOH) restored activity to some degree but did not restore it to the level of those possessing the hydroxyl substituent. Consequently, ivermectin and doramectin that possess hydroxyl moieties at C-5 were superior against H. contortus to those like selamectin that have oxime substituents. There was no advantage for analogs with a single or double bond at C-22,23 within the cyclohexyl series, and these analogs had equivalent activity as those with a single bond at C-22,23 in the sec-butyl/isopropyl series. However, there was superior activity for the analog series that possessed the combination of a double-bond at C-22,23 and a sec-butyl/isopropyl substituent at C-25. As a result, the most potent compound in this test was not any of the 3 commercialized avermectins but was a monosaccharide with a double bond at C-22,23, an hydroxyl at C-5, and a sec-butyl/isopropyl moiety at C-25.

Effects of isradipine on renal hemodynamics in renal transplant patients treated with cyclosporine

Cyclosporine A is the mainstay of modern immunosuppressant therapy in human organ transplants. However, its use has been associated with nephrotoxicity and hypertension that may be hemodynamically mediated. This study was undertaken to see if the calcium channel blocker, isradipine, could improve renal hemodynamics by decreasing renal vascular resistance and to determine its effects on cyclosporine pharmacokinetics. Eighteen hypertensive renal transplant recipients (3 to 60 months post transplant) were enrolled. Antihypertensive medications were stopped. Patients were placed on isradipine and followed for 8 weeks. Blood pressure, creatinine clearance, cyclosporine trough levels, and renal plasma flow using p-aminohippurate clearance, were measured pre- and at 8 weeks of therapy. Only one patient did not complete renal plasma flow measurement. Systolic and diastolic blood pressures dropped significantly (p < 0.001) from baseline to 8 weeks with isradipine. Sbp decreased from 166 +/- 18 to 142 +/- 14 mmHg and Dbp decreased from 97 +/- 8 to 82 +/- 10 mmHg (mean +/- 1 SD). Renal vascular resistance, calculated from mean arterial pressure and renal blood flow, decreased significantly (p < 0.002) from 0.57 +/- 0.21 to 0.41 +/- 0.12 mmHg/ml/min (mean +/- 1 SD). Isradipine appeared to have no significant effect on cyclosporine trough levels, creatinine clearance, or renal plasma flow. This study shows a role for isradipine use in renal transplant recipients on cyclosporine. Renal vasoconstriction caused by cyclosporine may be partially prevented with isradipine therapy. Furthermore, isradipine is effective in the treatment of hypertension in renal transplant recipients without affecting cyclosporine levels.

A 6-month study of low-dose recombinant human erythropoietin alone and in combination with androgens for the treatment of anemia in chronic hemodialysis patients

Two previous short-term studies (12 weeks and up to 16 weeks) that used androgens to supplement recombinant human erythropoietin (rHuEPO) for the treatment of the anemia associated with end-stage renal disease showed divergent results. Both studies were limited by their brief duration, since the hematopoietic effect of androgens does not peak until 5 months. Therefore, we conducted a 6-month, prospective, randomized trial comparing low-dose rHuEPO alone and in combination with androgens for the treatment of the anemia of end-stage renal failure. Nineteen anemic chronic hemodialysis patients were randomized into two groups. Group A (n = 10) received 1,500 U rHuEPO intravenously three times a week for 26 weeks. Group B (n = 9) received the same dose of rHuEPO plus nandrolone decanoate 100 mg intramuscularly weekly. Baseline transferrin saturation, serum ferritin, intact serum parathyroid hormone, plasma aluminum, and hematocrit levels were not significantly different between the groups. At study completion, both groups showed a significant increase in mean hematocrit compared with baseline (group A: 24.8% +/- 1.4% to 28.3% +/- 2.8%, P = 0.003; group B: 25.1% +/- 1.5% to 33.2% +/- 4.5%, P = 0.001). The increase in hematocrit in the rHuEPO plus androgen-treated group was statistically greater than in the rHuEPO-alone group (8.2% +/- 4.4% v 3.5% +/- 2.8%; P = 0.012). With the exception of mild discomfort at the injection site, there were no significant side effects from nandrolone. We conclude that the combination of low-dose rHuEPO and nandrolone decanoate is effective treatment for the anemia of end-stage renal failure.

Plasma leptin is partly cleared by the kidney and is elevated in hemodialysis patients

Leptin, the gene product of the ob gene, is important in the control of appetite in rodents and may have an important role in humans. The clearance of leptin from the circulation is unknown. As the leptin receptor is present in the kidney, we evaluated the role of the kidney in removing circulating leptin in humans. We measured leptin in aortic and renal vein plasma in 8 patients with intact renal function and 6 patients with impaired renal function who were undergoing elective cardiac catheterization. Renal blood flow was measured in all patients to calculate net mass balance across the kidney. In patients with intact renal function there is net renal uptake of 12% of circulating leptin, whereas in patients with renal insufficiency there is no renal uptake of leptin. In a separate cohort of 36 patients with end-stage renal failure on hemodialysis, peripheral leptin levels factored for body mass index was increased by > fourfold as compared to a group of healthy controls (N = 338). In addition, plasma leptin is not cleared by hemodialysis with a modified cellulose membrane. Additional studies are required to evaluate the role of leptin in mediating the anorexia of uremia.

Audit of waste collected over one week from ten dental practices. A pilot study

An audit of the waste practices of ten general dental surgeries identified problems that have occurred due to the lack of specific dental guidelines or codes of practice in this area. Occupational health and safety requirements for types and locations of sharps containers, and lack of consensus on what constitutes a sharp, were identified as areas needing attention. Cross-infection control items, such as gloves, masks, single-use cups, and protective coverings, were found to constitute up to 91 per cent of total waste. When infectious waste was reclassified by the audit team as 'that waste which was visibly blood stained,' a reduction in waste in this category was made, during the audit, at each practice. The practice of disposing of radiographic fixer and developer into the sewerage system occurred in three out of the ten practices, even though the Australian Dental Association Inc. has discouraged this practice.

Chronic renal disease: new therapies to delay kidney replacement

Several factors promote the progression of renal disease, including glomerular hypertension and hypertrophy, molecular factors such as cytokines and growth hormones, proteinuria, acidosis, and hyperlipidemia. Regardless of the underlying etiology, many patients with chronic renal insufficiency will ultimately require kidney replacement therapy. Your goal is to delay the progression of renal failure, mainly through aggressive control of blood pressure. Other possible interventions include protein restriction, bicarbonate therapy, and lipid-lowering drugs.

Evaluation of multileaf collimator design for a photon beam

Various aspects of multileaf collimator (MLC) design are examined relative to clinical requirements. The characteristics studied included: (a) irregular field edge definition or "effective" penumbra, (b) optimum field coverage for the multileaf portion of the field, and (c) leaf velocity. A film dosimetry technique was developed to measure the rapid 2-dimensional change in dose at an edge defined by a multileaf collimator with the segments staggered. The method applies a correction factor which allows for the changing ratio of scattered to primary photons at the field edge so that the energy dependence of the film is corrected. Stepped lead alloy blocks were irradiated with 6 MV photons to obtain films simulating a double-focused multileaf collimator, and the results were compared to films of fields shaped with standard divergent blocks. The effect of the shape of the leaf face (the end of the leaf) on penumbra was also studied. Proper shaping of the leaf ends may eliminate the need to exactly match beam divergence so that the mechanical of the collimator system is simplified. Leaves having several different end shapes and moving horizontally to intercept a vertical beam were compared to the divergent design where a straight face moves along an arc. The measurements showed that the "effective" penumbra (measured as the distance from the 80 to 20% isodose lines) for the multileaf collimator is a function of the angle between the direction of leaf motion and the edge defined by the leaves. In addition, all leaf end shapes showed some increase in penumbra compared to standard divergent blocking and also had increasing penumbra width as they moved over or back from the field center line. A total of 459 treatment fields and six disease sites were examined to determine the percentage of fields potentially shaped by multileaf segments of specified length. This study showed 93% of the fields had lengths of 30 cm or less and 99% had widths of 25 cm or less. A study conducted to determine the required leaf velocity to shape various target volume configurations during complete rotation (at 1 RPM) showed that a leaf speed of at least 1.5 cm/sec at isocenter is needed for dynamic conformal treatment.

Speed of information-processing and structural limitations by mentally retarded and dual-diagnosed retarded-schizophrenic persons

Three experiments were conducted in an investigation of information-processing capabilities of mentally retarded adults, nonretarded children (mental age control), and nonretarded adults (chronological age control). In all experiments, one of two target stimuli was presented to the center and to the right or left of central fixation. Subjects were required to detect the presence of a stimulus in a yes-no forced-choice paradigm (Experiment 1), identify which of the two targets had been presented in a forced-choice discrimination paradigm (Experiment 2), or distinguish between the targets in a forced-choice discrimination task when the target was preceded by, presented stimultaneously with, or followed by a patterned noninformational masking stimulus. The findings support the theory of a structural defect in mentally retarded persons that results in slow information-processing.

Anthelmintic activity of mebendazole against induced and naturally occurring helminth infections in cats

A formulation of mebendazole was used to determine the optimal dosage level against induced and/or naturally occurring infections of Toxocara cati, Ancylostoma tubaeforme, and Taenia taeniaeformis in cats. Amounts of 11 mg/kg of body weight/day or 22 mg/kg/day were given for 2, 3, or 4 days. Feces were collected for 7 days and were examined for expelled parasites. Cats were necropsied to recover retained parasites. A regimen of 22 mg/kg/day for 3 days was determined to be optimal with efficacies of 100%, 99%, and 50% against T cati, A tubaeforme, and Taenia taeniaeformis, respectively.

Comparative anthelmintic efficacy of two schedules of mebendazole treatment in dogs

Two schedules of anthelmintic oral treatment, using mebendazole powder, were compared in 73 dogs naturally infected with common helminth intestinal parasites. Mebendazole powder was administered to 26 dogs at doses of 22 mg/kg once daily for 3 days and was compared with the same dose given only daily for 5 days into 23 dogs. The 24 other dogs were kept as controls and received a placebo treatment for 5 days. Efficacy results for the 3-day treatment schedule of mebendazole were as follows: Toxocara canis, 100%; Uncinaria stenocephala, 100%; Ancylostoma caninum, 99.4%; Trichuris vulpis, 100%; and Taenia pisiformis, 93.9%. Mebendazole powder given on the 5-day treatment schedule was 100% efficacious against the foregoing parasites. Anthelmintic efficacy against Dipylidium caninum was not detected in either schedule of treatment.