Sequential dual-site High-Definition transcranial Direct Current Stimulation (HD-tDCS) treatment in chronic subjective tinnitus: study protocol of a double-blind, randomized, placebo-controlled trial.

BACKGROUND: Chronic tinnitus is a highly prevalent symptom, with many patients reporting considerable effects of tinnitus on quality of life. No clear evidence-based treatment options are currently available. While counseling-based methods are valuable in some cases, they are not sufficiently effective for all tinnitus patients. Neuromodulation techniques such as high-definition transcranial direct current stimulation (HD-tDCS) are proposed to have positive effects on tinnitus severity but, to date, these effects have not been proven conclusively. The proposed trial will investigate the hypothesis that chronic tinnitus patients receiving HD-tDCS will report a positive effect on the impact of tinnitus on daily life, as compared to patients receiving sham stimulation. METHODS: This study proposes a randomized, double-blind, placebo-controlled trial with parallel group design. A total of 100 chronic tinnitus patients will be randomly allocated to an experimental group or a sham group, with allocation stratified according to gender and tinnitus severity. Patient and researcher will be blinded to the patient's allocation. Patients will undergo six sessions of sequential dual-site HD-tDCS of the left temporal area and the right dorsolateral prefrontal cortex. Evaluations will take place at baseline, immediately following treatment, and at three and six months after the start of the therapy. The primary outcome measure is the change in Tinnitus Functional Index (TFI) score. Secondary outcome measures include audiological measurements, cortical auditory evoked potentials, the Repeatable Battery for the Assessment of Neuropsychological Status adjusted for hearing-impaired individuals (RBANS-H), and supplementary questionnaires probing tinnitus severity and additional symptoms. By use of a linear regression model, the effects of HD-tDCS compared to sham stimulation will be assessed. DISCUSSION: The objective of this study is to evaluate whether HD-tDCS can reduce the impact of tinnitus on daily life in chronic tinnitus patients. To date, published trials on the effects of HD-tDCS on tinnitus suffer from a lack of standardization and few randomized controlled trials exist. The proposed study will be the first adequately powered trial to investigate the effects of sequential dual-site HD-tDCS on tinnitus severity. TRIAL REGISTRATION: ClinicalTrials.gov, NCT03754127 . Registered on 22 November 2018.

In vitro 'time-to-kill' assay to assess the cidal activity dynamics of current reference drugs against Leishmania donovani and Leishmania infantum.

OBJECTIVES: Despite a continued search for novel antileishmanial drugs, treatment options remain restricted to a few standard drugs, e.g. antimonials, miltefosine, amphotericin B and paromomycin. Although these drugs have now been used for several decades, their mechanism of action still remains partly hypothetical and their dynamics of cidal action and time-to-kill are still poorly documented. METHODS: An in vitro time-to-kill assay on intracellular amastigotes of the laboratory reference strains Leishmania donovani (MHOM/ET/67/L82) and Leishmania infantum [MHOM/MA(BE)/67/ITMAP263] evaluated the cidal action dynamics of the listed reference drugs at three different concentrations: at IC50, 2 × IC50 and the near cytotoxic dose level (CC90: determined on MRC-5 cells). This assay focused on identifying the minimal exposure time needed to completely eliminate viable intracellular amastigotes, using the standard microscopic Giemsa assay and the promastigote back-transformation assay. RESULTS: While 100% reduction was microscopically apparent for most drugs, the promastigote back-transformation assay clearly demonstrated a concentration- and time-dependent cidal mechanism. The time-to-kill at 2 × IC50 was ≥240 h for pentavalent antimony (77 µg eq./mL), 96 h for trivalent antimony (44 µg eq./mL), 168 to >240 h for miltefosine (10 µM), 168 h for paromomycin (100 µM) and >240 h for amphotericin B (2 µM). No differences were noted between both Leishmania species. CONCLUSIONS: Evaluation of the concentration- and time-dependent cidal activity using the promastigote back-transformation assay revealed striking differences in efficacy of the different antileishmanial reference drugs. This assay should allow in-depth pharmacodynamic evaluation of novel drug leads in comparison with the existing antileishmanial drug repertoire.

Evidence of a drug-specific impact of experimentally selected paromomycin and miltefosine resistance on parasite fitness in Leishmania infantum.

OBJECTIVES: Although miltefosine and paromomycin were only recently introduced to treat visceral leishmaniasis, increasing numbers of miltefosine treatment failures and occasional primary resistance to both drugs have been reported. Understanding alterations in parasite behaviour linked to drug resistance is essential to assess the propensity for emergence and spread of resistant strains, particularly since a positive effect on fitness has been reported for antimony-resistant parasites. This laboratory study compared the fitness of a drug-susceptible parent WT clinical Leishmania infantum isolate (MHOM/FR/96/LEM3323) and derived miltefosine and paromomycin drug-resistant lines that were experimentally selected at the intracellular amastigote level. METHODS: Parasite fitness of WT, paromomycin-resistant and miltefosine-resistant strains, in vitro and in vivo parasite growth, metacyclogenesis, infectivity and macrophage stress responses were comparatively evaluated. RESULTS: No significant differences in promastigote fitness were noted between the WT and paromomycin-resistant strain, while clear benefits could be demonstrated for paromomycin-resistant amastigotes in terms of enhanced in vitro and in vivo growth potential and intracellular stress response. The miltefosine-resistant phenotype showed incomplete promastigote metacyclogenesis, decreased intracellular growth and weakened stress response, revealing a reduced fitness compared with WT parent parasites. CONCLUSIONS: The rapid selection and fitness advantages of paromomycin-resistant amastigotes endorse the current use of paromomycin in combination therapy. Although a reduced fitness of miltefosine-resistant strains may explain the difficulty of miltefosine resistance selection in vitro, the growing number of miltefosine treatment failures in the field still requires further exploratory research.

Nutrition Screening Tool for Every Preschooler (NutriSTEP): validation and test-retest reliability of a parent-administered questionnaire assessing nutrition risk of preschoolers.

OBJECTIVES: Study 1: To establish the validity of scores on Nutrition Screening Tool for Every Preschooler (NutriSTEP), a community-based parent-administered screening tool for assessing nutrition risk, by comparing scores to an expert rating. Study 2: To demonstrate test-retest reliability of NutriSTEP. SUBJECTS/METHODS: Study 1: Parents of 269 preschoolers (of 294 parents recruited from the community), completed the NutriSTEP questionnaire; a registered dietitian (RD) assessed the nutritional status (based on medical and nutritional history, 3 days of dietary recall and anthropometric measurements) of these preschoolers and rated their nutritional risk (1 (low) to 10 (high risk)). Receiver operating characteristic (ROC) curves were used to establish validity and determine appropriate cut points based on sensitivity and specificity. Study 2: Parents of 140 preschoolers (of 161 recruited) completed NutriSTEP on two occasions. Intraclass correlation (ICC) and kappa were used to assess reliability. RESULTS: Study 1: Scores on NutriSTEP and the RD rating were correlated (r=0.48, P=0.01). Area under the ROC curve for the high risk RD rating (score 8+) and the moderate risk rating (score 5+) were 81.5 and 73.8%, respectively. A moderate risk cut point of >20 and high risk cut point of >25 were identified for the NutriSTEP scores. Study 2: The NutriSTEP score was reliable between administrations (ICC=0.89, F=16.7, P<0.001). Most items on the questionnaire had adequate (kappa>0.5) or excellent (kappa>0.75) agreement. CONCLUSIONS: The NutriSTEP questionnaire is both valid and reliable for determining nutritional risk in preschoolers.

Youth alcohol and other drug use in the United States and Australia: a cross-national comparison of three state-wide samples.

Although youth drug and alcohol harm minimization policies in Australia are often contrasted with the abstinence and zero tolerance policies adopted in the United States, there has been little research directly comparing youth substance use behaviour in the two countries. Three state representative samples in Victoria, Australia (n = 7898) and in the US states of Oregon (n = 15,224) and Maine (n = 16,245) completed a common cross-sectional student survey. Rates of alcohol use (lifetime alcohol use, recent use in the past 30 days), alcohol use exceeding recommended consumption limits (binge drinking: five or more drinks in a session), other licit drug use (tobacco use), and norm-violating substance use (substance use at school, use in the past 30 days of marijuana or other illicit drug use) were compared for males and females at ages 12-17. Rates were lower (odds ratios 0.5-0.8) for youth in Maine and Oregon compared to Victoria for lifetime and recent alcohol use, binge drinking and daily cigarette smoking. However, rates of recent marijuana use and recent use of other illicit drugs were higher in Maine and Oregon, as were reports of being drunk or high at school. In contradiction of harm minimization objectives, Victoria, relative to the US states of Oregon and Maine, demonstrated higher rates of alcohol use exceeding recommended consumption limits and daily tobacco use. However, findings suggested that aspects of norm-violating substance use (substance use at school, marijuana use and other illicit drug use) were higher in the US states compared to Victoria.

What predicts adolescent violence in better-off neighborhoods?

Predictors of repeated violent delinquency across ages 13-19 were investigated in a longitudinal sample of 420 urban adolescent males living in high- compared to low-socioeconomic status (SES) neighborhoods. Adolescents in high-SES neighborhoods were significantly less likely than their counterparts in low-SES neighborhoods to engage in serious and violent delinquency. Results indicated that risk factors for later repeated violence among adolescents in high-SES neighborhoods, such as physical aggression, may be biologically based, whereas risk factors for later violence among adolescents in low-SES neighborhoods, such as poor parent-adolescent communication and early intercourse, appeared to be context-dependent. Having positive attitudes toward problem behavior and delinquent peers increased risk for later violence regardless of neighborhood SES type. Theoretical and practical implications of the findings are discussed.

Diphenylhydantoin is not genotoxic in a battery of short-term cytogenetic assays.

5,5-Diphenylhydantoin (DPH) is an antiepileptic drug associated with an increase in malformations in infants born to women taking DPH during pregnancy. Positive and negative results have been reported by various investigators for in vivo and in vitro chromosome aberration (CAB) assays, in vivo and in vitro sister chromatid exchange (SCE) assays, and in vivo micronucleus tests (MNT). In this laboratory, DPH was tested in an in vitro CAB assay using Chinese hamster ovary cells with and without an S-9 activation system, an in vivo SCE assay in female CD-1 mice, an in vivo MNT, using both male and female CD-1 mice, and a transplacental micronucleus test. The results from this comprehensive battery of cytogenetic tests were uniformly negative and support a conclusion that the known teratogen, DPH, is not clastogenic.

Expulsion of demecolcine-induced micronuclei from mouse bone marrow polychromatic erythrocytes.

The mouse micronucleus test is a valuable tool for evaluating in vivo chromosome damage produced by test articles in polychromatic erythrocytes of bone marrow. Compounds that are clastogens, such as cyclophosphamide, induce micronuclei that are smaller than those induced by compounds that are spindle poisons, such as demecolcine. In vitro studies have previously shown that the frequency of mitomycin C- and vincristine-induced micronuclei in mouse L-929 cells was reduced due to micronuclear extrusion following treatment with cytochalasin B. The current study shows that micronuclei are also expelled in vivo, that expulsion is dependent upon micronuclear size, and that observation of these extruded micronuclei is dependent upon the method of sample preparation.

The evaluation of a multiple dosing protocol for the mouse bone-marrow micronucleus assay using benzidine and 2,6-xylidine.

Male ICR mice were treated with 1, 2 or 3 daily doses of either benzidine or 2,6-xylidine. Groups of 5 animals were sacrificed 24 h after the last dose and the bone marrow examined for micronuclei. Benzidine was given at dose levels of 40 and 200 mg/kg and 2,6-xylidine was given at dose levels of 75 and 375 mg/kg. These doses represent 10 and 50% of the respective median lethal doses. Benzidine produced a significant (p less than 0.001) dose related increase in the incidence of micronucleated polychromatic erythrocytes (MPE), while 2,6-xylidine had no effect on the frequency of micronucleated cells. Statistical analyses of the data indicated that the incidence of MPE was independent of the number of doses administered prior to bone marrow harvest.

Mutagenicity evaluation of HC Blue No. 1 and HC Blue No. 2, I. Effect on the induction of micronuclei in mouse bone marrow cells.

Two hair-dye chemicals, HC Blue No. 1 and HC Blue No. 2, were assessed for the ability to produce chromosome breakage and/or spindle malformation in vivo by evaluating the capacity of these compounds to induce micronuclei in polychromatic erythrocytes of mouse bone marrow. Initial studies were conducted in ICR male and female mice given a single intraperitoneal dose of 1000, 500 or 250 mg/kg body weight and examined for micronucleus induction 24 or 48 h later. Activity was observed in female mice given 1000 mg/kg of HC Blue No. 1 at the 24-h harvest time. A questionable response was noted with HC Blue No. 2 in males at the 1000 mg/kg, 24-h time point. No activity was observed in either sex at the 48-h harvest time. In a second set of studies, mice from two strains, ICR and CD-1, were administered a single intraperitoneal dose of 1000 mg/kg of each chemical and the bone marrow was extracted 24 h later. In these experiments, HC Blue No. 1 again produced a statistically significant elevation of micronuclei in female ICR mice. No significant effect was observed in CD-1 mice of either sex. HC Blue No. 2 did not produce any significant elevation of micronuclei in either sex of ICR or CD-1 mice.

Water content effects on photosynthetic response of Sphagnum mosses from the foothills of the Philip Smith Mountains, Alaska.

In tussock tundra areas of the foothills north of the Brooks Range, Alaska, up to two-thirds of annual precipitation may occur during intermittent summer thunderstorms. The seasonal pattern in capitulum water content of Sphagnum spp. depends on the frequency and duration of these precipitation events, on the microtopography of the habitat including depth of thaw, and on morphological characteristics of the individual species. The response of net photosynthesis to varying water content in Sphagnum squarrosum and S. angustifolium growing under willow canopies in a tussock tundra area near the Dalton Highway on the North Slope of Alaska was examined in the field. After a period in June required to develop photosynthetic capability, capitula water content was essentially optimal for photosynthesis in the range from 6 to 10 g H2O/g DW. Above this range, the rate of CO2 uptake was reduced, presumably due to limitations on CO2 diffusion to the photosynthetically active sites. At water contents below the optimum, net photosynthesis fell rapidly until reaching compensation at approximately 1 g H2O/g DW. Dependent on changes in weather conditions, average water content of Sphagnum samples collected in the field occasionally fell below 5 g H2O/g DW. During a particularly dry period, water content of individual Sphagnum hummocks fell below 1 g H2O/g DW, indicating that water stress does limit Sphagnum photosynthetic production in this habitat.

Irradiance and temperature effects on photosynthesis of tussock tundra Sphagnum mosses from the foothills of the Philip Smith Mountains, Alaska.

Photosynthetic characteristics of three species of Sphagnum common in the foothills of the Brooks Range on the North Slope of Alaska were investigated. Generally, light-saturated rates of net photosynthesis decreased in the order S. squarrosum, S. angustifolium, and S. warnstorfii when plants were grown under common growth chamber conditions. For field-grown S. angustifolium, average light compensation point at 10°C was 37 µmol m-2s-1 photosynthetic photon flux density (PPFD), and light saturation occurred between 250 and 500 µmol m-2 s-1. At 20°C, compensation point increased to 127 µmol m-2s-1 and the PPFD required for light saturation increased to approximately 500 µmol m-2s-1, while maximum rates of CO2 uptake increased only slightly. Light response curves of chamber-grown plants exhibited substantially lower compensation points and higher light-saturated rates of CO2 assimilation than field-grown material, due perhaps to a higher percentage of green, photosynthetically competent tissue. All three species exhibited broad responses to temperature, with optima near 20°C, and maintained at least 75% of maximum assimilation between approx. 13° and 30°C. Rates at 5°C were approx. 50% of maximum. Studies of the microclimate of Sphagnum at the field research site suggest that CO2 uptake should occur at near light-saturated rates during the day in open tussock tundra but that PPFD may often be limiting under Salix and Betula canopies in a water track drainage. Simulations using a simple model provided a seasonal estimate of 0.78 g dry weight (DW) of S. angustifolium produced from each initial g of photosynthetic tissue under willow canopies, assuming no water limitations. Although the simulation model suggests that production would be 66% higher in open tussock tundra, S. angustifolium is rarely found in this potentially more stressful habitat. To explain the relative abundance of Sphagnum in shaded water track areas as compared to open tussock tundra, we postulate that the vascular plant canopies provide protection from adverse effects of high temperatures, excess irradiance and reduced water availability. Under conditions of normal water availability, removal of the vascular plant cover did not affect the tissue water content of S. squarrosum, but resulted in a strong decrease in photosynthetic capacity, accompanied by chlorophyll bleaching. These results suggest that photoinhibition may limit production under certain conditions.

The visible wall of a main bronchus: a new radiological sign of pneumomediastinum.

A new sign of pneumomediastinum (mediastinal emphysema), namely a visible wall of a main bronchus as seen in the mediastinum on frontal radiographs of the chest, is described. This sign was present in eight out of 20 random cases of pneumomediastinum in adolescents and adults.

Nuclear magnetic resonance imaging. Experience with the first 100 cases at Tygerberg Hospital.

Facilities for magnetic resonance imaging (MRI) have been available in South Africa since November 1985. This article summarizes our experience with this new imaging modality, illustrates normal anatomical features and pathological conditions in sagittal, coronal and axial planes, and compares MRI with computed tomography scans of the same regions.

[Chronic splenic abscess : a case report]. / Chroniese miltabses; 'n Gevalbespreking.

A 16-year-old girl had had a splenic abscess for approximately 20 months with minimal symptoms and signs. Progressive elevation of the left hemidiaphragm could be traced on chest radiographs from 20 months before admission, and was shown on ultrasonography, radionuclide scintigraphy and computed tomography to be secondary to massive splenomegaly. The presence of splenic abscesses was confirmed by laparotomy and she was cured by splenectomy. The nonspecific clinical presentation and potential high mortality of this condition are stressed, and the role of diagnostic aids is discussed. Ultrasonography is a good screening procedure in terms of cost and speed, but splenic scintigraphy is more sensitive. Computed tomography is the most sensitive and specific non-invasive procedure for the diagnosis of splenic abscesses.

Interstitial lung disease. Part I. A multidisciplinary approach to the diagnosis and assessment of disease activity.

The value of alveolar lavage as an investigative technique was determined in patients with interstitial lung disease. Alveolar cytology was related to defined histopathological degrees of disease activity found in transbronchial biopsy specimens. The degree of disease activity as assessed by these two techniques was compared with radiological evaluation. Adequate specimens of lung tissue for histopathological evaluation were obtained by transbronchial biopsy in 95% of the subjects during the first procedure and diagnostic histopathological changes were found in 60% of the patients. In the evaluation of disease activity, the lymphocyte-macrophage (L-M) ratio and, to a lesser extent, the total alveolar cell counts correlated well with graded histopathological changes of activity. A graded radiological evaluation of activity was accurate in 14 out of 17 patients, but in 3, extreme cellular disease ws not recognized. Alveolar cytological examination can be employed as a supplement to the biopsy technique for increased accuracy in the initial and follow-up evaluation of active interstitial lung disease. An approach combining transbronchial biopsy, alveolar lavage and radiography, provides a safe and accurate alternative to openlung biopsy in most patients for determining the aetiology and degree of activity of interstitial lung disease.

[Approaches to the analysis of radiographs of the lungs]. / Benadering van interpretasie van röntgenfoto's van die longe.

Different approaches to the analysis of radiographs of the lungs are briefly discussed. A systematic routine is proposed, outlined and briefly motivated. It is emphasized that radiological findings must be correlated with clinical findings if meaningful conclusions are to be drawn.

The radiological features of primary pulmonary tuberculosis.

A very brief review is given of the pathology of primary pulmonary tuberculosis. Numerous characteristic, but not pathognomonic, radiological appearances of primary pulmonary tuberculosis are briefly described and some of them are illustrated. The final diagnosis, however, depends on correlating the radiological picture with the clinical picture and special investigations.