Rapid artefact removal and H&E-stained tissue segmentation.

We present an innovative method for rapidly segmenting haematoxylin and eosin (H&E)-stained tissue in whole-slide images (WSIs) that eliminates a wide range of undesirable artefacts such as pen marks and scanning artefacts. Our method involves taking a single-channel representation of a low-magnification RGB overview of the WSI in which the pixel values are bimodally distributed such that H&E-stained tissue is easily distinguished from both background and a wide variety of artefacts. We demonstrate our method on 30 WSIs prepared from a wide range of institutions and WSI digital scanners, each containing substantial artefacts, and compare it to segmentations provided by Otsu thresholding and Histolab tissue segmentation and pen filtering tools. We found that our method segmented the tissue and fully removed all artefacts in 29 out of 30 WSIs, whereas Otsu thresholding failed to remove any artefacts, and the Histolab pen filtering tools only partially removed the pen marks. The beauty of our approach lies in its simplicity: manipulating RGB colour space and using Otsu thresholding allows for the segmentation of H&E-stained tissue and the rapid removal of artefacts without the need for machine learning or parameter tuning.

Ultrasonic enhancement of battery diffusion.

It has been demonstrated that sonic energy can be harnessed to enhance convection in Galvanic cells during cyclic voltammetry; however, the practical value of this approach is limited due to the lack of open volumes for convection patterns to develop in most batteries. This study evaluates the ability of ultrasonic waves to enhance diffusion in membrane separators commonly used in sandwich-architecture batteries. Studies include the measuring of open-circuit performance curves to interpret performances in terms of reductions in concentration overpotentials. The use of a 40 kHz sonicator bath can consistently increase the voltage of the battery and reduce overpotential losses up to 30%. This work demonstrates and quantifies battery enhancement due to enhanced diffusion made possible with ultrasonic energy.

Assessment and evaluation of contact as a risk factor for tuberculosis in rural Africa.

SETTING: A rural district in Malawi. OBJECTIVE: To determine the effect of inaccurate recall on estimates of the proportion of tuberculosis (TB) cases attributable to contact with identifiable prior cases. DESIGN: Case-control study of laboratory-confirmed TB cases and community controls, comparing family, household and area contacts identified from a database of TB cases with those named at interview. Estimation of prior contact as a risk factor for TB and identified factors associated with being a named contact. RESULTS: Ninety-five per cent of named contacts were known TB cases. The proportion of total identified contacts who were named at interview was 75%, and was similar for cases and controls. Cases were twice as likely as controls to identify prior contacts. Adding database information did not affect odds ratios, but increased the proportion of TB cases attributable to prior contact. Smear-positive, male and human immunodeficiency virus (HIV) negative TB patients were more likely to be named by subsequent cases. Identifiable recent contact with known smear-positive cases accounted for 12.5% of the TB burden. CONCLUSIONS: Reporting of putative source contacts showed little evidence of recall bias and gave estimates of the relative risk of TB associated with identifiable contact. The lower likelihood of HIV-positive cases being named as contacts may reflect reduced infectiousness.

Ascertainment of childhood vaccination histories in northern Malawi.

OBJECTIVE: To assess factors related to recorded vaccine uptake, which may confound the evaluation of vaccine impact. METHODS: Analysis of documented vaccination histories of children under 5 years and demographic and socio-economic characteristics collected by a demographic surveillance system in Karonga District, Malawi. Associations between deviations from the standard vaccination schedule and characteristics that are likely to be associated with increased mortality were determined by multivariate logistic regression. RESULTS: Approximately 78% of children aged 6-23 months had a vaccination document, declining to <50% by 5 years of age. Living closer to an under-5 clinic, having a better educated father, and both parents being alive were associated with having a vaccination document. For a small percentage of children, vaccination records were incomplete and/or faulty. Vaccination uptake was high overall, but delayed among children living further from the nearest under-5 clinic or from poorer socio-economic backgrounds. Approximately 9% of children had received their last dose of DPT with or after measles vaccine. These children were from relatively less educated parents, and were more likely to have been born outside the health services. CONCLUSIONS: Though overall coverage in this community was high and variation in coverage according to child or parental characteristics small, there was strong evidence of more timely coverage among children from better socio-economic conditions and among those who lived closer to health facilities. These factors are likely to be strong confounders in the association of vaccinations with mortality, and may offer an alternative explanation for the non-specific mortality impact of vaccines described by other studies.

The influence of previous exposure to environmental mycobacteria on the interferon-gamma response to bacille Calmette-Guérin vaccination in southern England and northern Malawi.

We report a large study of the effect of BCG vaccination on the in vitro 6-day whole blood interferon-gamma (IFN-gamma) response to antigens from eight species of mycobacteria among schoolchildren in south-eastern England, where bacille Calmette-Guérin (BCG) vaccination is highly protective against pulmonary tuberculosis, and among young adults in northern Malawi, where BCG vaccination is not protective. In the UK children, BCG induced an appreciable increase in IFN-gamma response to antigens from most species of mycobacteria. The degree of change was linked to the relatedness of the species to Mycobacterium bovis BCG, and provides further evidence of the cross-reactivity of mycobacterial species in priming of the immune system. IFN-gamma responses to purified protein derivatives (PPDs) from M. tuberculosis and environmental mycobacteria were more prevalent in the Malawian than the UK group prior to vaccination; BCG vaccination increased the prevalence of responses to these PPDs in the UK group to a level similar to that in Malawi. There was no evidence that the vaccine-induced change in IFN-gamma response was dependent upon the magnitude of the initial response of the individual to environmental mycobacteria in the United Kingdom or in Malawi. These observations should assist the development and interpretation of human clinical trials of new vaccines against M. tuberculosis in areas of both low and high exposure to environmental mycobacteria.

Side population/ABCG2-positive cells represent a heterogeneous group of haemopoietic cells: implications for the use of adult stem cells in transplantation and plasticity protocols.

Murine side population (SP) cells may have an increased ability to engraft lethally irradiated mice and lack CD34 expression. Strategies using CD34 as a primary marker of haemopoietic stem cells may therefore result in the exclusion of a primitive stem cell population. The molecular basis for the murine SP phenotype has been attributed to the multidrug-resistance transporter ABCG2. This study aimed to investigate ABCG2 expression from a variety of human sources and investigate the relationship between ABCG2 expression, the SP phenotype, and expression of markers such as CD34 and CD133. SP cells were observed in different haemopoietic sources, but a significant increase in the number of SP cells was observed in PB following granulocyte colony-stimulating factor mobilisation. No direct correlation between the frequency of SP cells and the expression of ABCG2 was observed. SP cells were identified in both lineage-positive and lineage-negative population and ABCG2 expression was enriched in lineage-negative SP cells. Lineage-negative SP cells were devoid of CD34 expression but enriched for CD133. Subsequent analysis revealed that ABCG2 and CD133 are coexpressed. Together, these data suggest that the ABCG2 transporter is neither required nor responsible for the SP phenotpye in many human blood cells.

Interferon-gamma and skin test responses of schoolchildren in southeast England to purified protein derivatives from Mycobacterium tuberculosis and other species of mycobacteria.

The immune responses of schoolchildren in southeast England to Mycobacterium tuberculosis and other species of mycobacteria were studied prior to vaccination with bacille Calmette-Guérin (BCG). Data are presented for tuberculin (Heaf) skin test and interferon-gamma (IFN-gamma) responses to M. tuberculosis purified protein derivative (PPD), and IFN-gamma responses to PPDs from eight other environmental mycobacteria, measured in 424 schoolchildren (13-15 years of age). Responses to M. tuberculosis PPD were detected in 27% of schoolchildren by in vitro IFN-gamma response and in 20% by the Heaf test. IFN-gamma responses were more prevalent to PPDs from species of mycobacteria other than M. tuberculosis, predominantly those of the MAIS complex and M. marinum (45-60% responders). Heaf test and IFN-gamma responses were associated (P<0.001) for M. tuberculosis, MAIS and M. marinum. These findings have implications for appropriate implementation of vaccination against tuberculosis.

Structure of the extracellular domains of the human interleukin-6 receptor alpha -chain.

Dysregulated production of IL-6 and its receptor (IL-6R) are implicated in the pathogenesis of multiple myeloma, autoimmune diseases and prostate cancer. The IL-6R complex comprises two molecules each of IL-6, IL-6R, and the signaling molecule, gp130. Here, we report the x-ray structure (2.4 A) of the IL-6R ectodomains. The N-terminal strand of the Ig-like domain (D(1)) is disulfide-bonded to domain D(2), and domains D(2) and D(3), the cytokine-binding domain, are structurally similar to known cytokine-binding domains. The head-to-tail packing of two closely associated IL-6R molecules observed in the crystal may be representative of the configuration of the physiological dimer of IL-6R and provides new insight into the architecture of the IL-6R complex.

Polymorphisms in the Il12b gene affect structure and expression of IL-12 in NOD and other autoimmune-prone mouse strains.

Interleukin (Il)-12 is a heterodimeric cytokine composed of 35 and 40 kD chains that plays a key role in the induction of Th1 cells, a T cell subset involved in many autoimmune diseases. We report here the cDNA sequence encoding the IL-12 p40 subunit from the autoimmune-prone non-obese diabetic (NOD) mouse, which spontaneously develops type 1 diabetes. Compared with the C57BL/6 sequence, there are two base changes that lead to amino acid replacements. Other autoimmune-prone strains, but not the diabetes-resistant NOR strain, share the same allele as NOD. We found both trans- and cis- allele-dependent effects on levels of basal and induced IL-12p40 expression. Furthermore, we show that one of these changes results in a structural change in the p40 molecule, as evidenced by the failure of a monoclonal antibody to bind NOD IL-12. These findings have implications for the predisposition to autoimmune responses in NOD and other autoimmune-prone mouse strains.

Experimental inoculation of domestic cats (Felis domesticus) with Sarcocystis neurona or S. neurona-like merozoites.

Sarcocystis neurona is the parasite most commonly associated with equine protozoal myeloencephalitis (EPM). Recently, cats (Felis domesticus) have been demonstrated to be an experimental intermediate host in the life cycle of S. neurona. This study was performed to determine if cats experimentally inoculated with culture-derived S. neurona merozoites develop tissue sarcocysts infectious to opossums (Didelphis virginiana), the definitive host of S. neurona. Four cats were inoculated with S. neurona or S. neurona-like merozoites and all developed antibodies reacting to S. neurona merozoite antigens, but tissue sarcocysts were detected in only two cats. Muscle tissues from the experimentally inoculated cats with and without detectable sarcocysts were fed to laboratory-reared opossums. Sporocysts were detected in gastrointestinal (GI) scrapings of one opossum fed experimentally infected feline tissues. The study results suggest that cats can develop tissue cysts following inoculation with culture-derived Sarcocystis sp. merozoites in which the particular isolate was originally derived from a naturally infected cat with tissue sarcocysts. This is in contrast to cats which did not develop tissue cysts when inoculated with S. neurona merozoites originally derived from a horse with EPM. These results indicate present biological differences between the culture-derived merozoites of two Sarcocystis isolates, Sn-UCD 1 and Sn-Mucat 2.

Lymphatic filariasis in the Karonga district of northern Malawi: a prevalence survey.

In Malawi, two main foci of lymphatic filariasis (LF) are known to exist: one in the south, in the Shire valley, and the other in the north, along the Songwe River, on the border with Tanzania. There have been no formal surveys in the Songwe area since the 1960s but an opportunity arose in 2000-2001 to map LF in this area, in the context of a leprosy survey that formed part of the follow-up of a large leprosy and tuberculosis vaccine trial. Overall 687 immunochromatographic (ICT) tests were carried out. Wuchereria bancrofti antigenaemia was found in > 25% of adults in each of the 12 villages sampled (four in the Songwe area and eight in the rest of the Karonga district), with village prevalences varying from 28%-58%. Of the 685 adult male residents of the Songwe area who were each given full-body clinical examinations, 80 (11.7%) were identified as cases of hydrocele. Lymphoedema was found in seven (1.0%) of these adult males and in 29 (3.7%) of the 769 adult female residents of the Songwe area who were also examined. Microfilariae were detected in 33 (30.8%) of the 107 thick smears of night-blood samples that were made from individuals with positive ICT cards. The W. bancrofti infection focus in Karonga district is therefore wider than was previously known. This has important implications for the implementation and eventual impact of LF-control activities in this area.

Sarcocystis neurona reacting antibodies in Missouri feral domestic cats (Felis domesticus) and their role as an intermediate host.

Sarcocystis neurona is the parasite associated with equine protozoal myeloencephalitis (EPM). Recently, cats (Felis domesticus) have been implicated as a potential intermediate host in the life cycle of S. neurona. This study was initiated to determine whether cats have antibodies that react to S. neurona antigens similar to antibodies from horses with EPM, and to evaluate the role of cats as intermediate hosts in the parasite's life cycle. Nine feral cats were used for analysis. Only one had antibodies reacting to S. neurona antigens. Muscle tissue from this cat, with detectable sarcocysts in the tongue, was fed to an opossum (Didelphis virginiana). The opossum shed sporocysts, which were then fed to gamma-interferon receptor knockout mice. Histopathology, immunohistochemistry, parasite isolation and molecular analysis were used to examine the pathology and associated parasites in the mice. The study suggests that the domestic cat can serve as an intermediate host to S. neurona or a S. neurona-like organsim.

A multisite case report on the clinical use of sevoflurane in dogs.

The purpose of this report was to evaluate the clinical safety and efficacy of sevoflurane as an inhalant anesthetic in dogs. Subjective and objective data from 196 clinical cases utilizing sevoflurane as the maintenance anesthetic was collected at three sites. After preanesthetic evaluation, the attending anesthesiologist assigned the dogs to one of the following six anesthetic protocols: protocol 1, oxymorphone premedication and thiopental induction; protocol 2, oxymorphone/acetylpromazine premedication and thiopental induction; protocol 3, xylazine/butorphanol premedication and thiopental induction; protocol 4, opioid premedication and propofol induction; protocol 5, optional premedication and mask induction with sevoflurane in oxygen; and protocol 6, optional premedication and optional induction. The average quality of induction, maintenance, and recovery was good to excellent in all protocols. The three most common side effects during maintenance and recovery were hypotension, tachypnea, and apnea. Sevoflurane produces anesthesia in dogs comparable to the other inhalation anesthetics currently used (i.e., halothane and isoflurane) for diagnostic or therapeutic procedures.

Improvement in quality of life for cancer patients treated with epoetin alfa.

Anaemia is a common complication of cancer and cancer therapies, and fatigue is one of the most common symptoms of anaemia, disrupting functional performance and reducing overall quality of life. The positive effects of treating renal patients with recombinant human erythropoietin are well documented. This case report series details the specific effects of fatigue on individual patients with cancer and their way of life, and describes their significant improvement in lifestyle following the reversal of anaemia using recombinant human erythropoietin, epoetin alfa.

Inhaled carbon monoxide concentration during halothane or isoflurane anesthesia in horses.

OBJECTIVE: The purpose of this study was to assess carbon monoxide (CO) exposure during equine anesthesia with either halothane (H) or isoflurane (I) delivered in a circle rebreathing system. STUDY DESIGN: Prospective clinical investigation. ANIMALS: Fifty client-owned horses. METHODS: Horses were randomly assigned for anesthetic maintenance with H (n = 26) or I (n = 24). Two large animal anesthetic machines were used and assigned to a single agent for 2-4 weeks at a time. Machines were disassembled and soda lime changed prior to switching anesthetic agents. Inhalant anesthetic concentration and CO concentration were measured in gas samples obtained from the inspiratory limb of the anesthetic circuit. Values were recorded at 15 minute intervals for 90 minutes. Soda lime status (new or used) and mode of ventilation (spontaneous or mechanical) were also recorded. Data were analyzed using a five-factor ANCOVA with repeated measures. RESULTS: Inspired CO concentration for H and I increased from 1 +/- 3 and 6 +/- 11 ppm at baseline to 54 +/- 33 and 21 +/- 18 ppm at 90 min, respectively (mean +/- sd). H was associated with significantly greater CO concentrations than I at 30 to 90 min, although baseline CO was significantly greater in the I group than the H group. Oxygen flow rates were 9.9 +/- 0.5 L/min at baseline for H and I, and 5.0 +/- 0.4 and 5.0 +/- 0.7 L/min at 90 min for H and I, respectively. There were no significant differences between groups for O2 flow at any time point. Neither mechanical ventilation nor new versus used soda lime affected CO concentration. CONCLUSIONS: Significantly higher concentrations of CO were recorded during the administration of H than I. CLINICAL RELEVANCE: Levels of CO observed during the administration of either H or I for 90 minutes to horses were not clinically significant.

Effects of intramuscular sedative and opioid combinations on tear production in dogs.

The effect of commonly used sedation protocols on tear production rate was evaluated in dogs. Schirmer I tear tests were examined before and after intramuscular injection of acepromazine and oxymorphone (ACE + OXY; n = 7), diazepam and butorphanol (DIA + BUT; n = 8), and xylazine and butorphanol (XYL + BUT; n = 8). Two Schirmer I tear tests were also performed 15-25 min apart in dogs which received no sedative drugs (control; n = 4). Tear production rate decreased to 15 +/- 2, 17 +/- 1, and 6 +/- 1 mm min-1, respectively, while control animals averaged 21 +/- 2 mm min-1 at the same time point. Because XYL + BUT profoundly decreased tear production rate, we evaluated the two drugs separately. While BUT mildly decreased tear production when given alone to dogs (18 +/- 1 mm min-1; n = 5), xylazine had no effect on tear production. Thus it appears that the two agents act synergistically to decrease tear production rate in dogs. Moreover, sterile ocular lubricant or tear replacement should be used during XYL + BUT sedation.