-
[
Biotechniques,
2017]
Nematodes transmit environmental information, such as temperature or food availability, across generations. Amber Dance looks at how this is possible.
-
[
Nucleus,
2019]
During meiosis, homologous chromosomes undergo a dramatic movement in order to correctly align. This is a critical meiotic event but the molecular properties of this 'chromosomal dance' still remainunclear. We identified DEB-1 - an orthologue of mammalian vinculin - as a new component of the mechanistic modules responsible for attaching the chromosomes to the nuclear envelope as apart of the LINC complex. In early meiotic nuclei of C. elegans, DEB-1 is localized to the nuclear periphery and alongside the synaptonemal complex of paired homologues. Upon DEB-1 depletion, chromosomes attached to SUN-1 foci remain highly motile until late pachytene. Although the initiation of homologue pairing started normally, irregularities in the formation of the synaptonemal complex occur, and these results in meiotic defects such as increased number of univalents at diakinesis and high embryonic lethality. Our data identify DEB-1 as a new player regulating chromosome dynamics and pairing during meiotic prophase I.
-
[
Ann Trop Med Parasitol,
2007]
Although ultrasonography has allowed 'nests' of live adult worms and dilated lymphatics to be detected in the early stages of infection with Wuchereria bancrofti, previous attempts to locate such adult-worm nests in brugian filariasis have been unsuccessful. In this study, the successful location of live adult Brugia malayi parasites, in the lymphatics of the axilla, thigh, epitrochlear region and/or popliteal fossa of children aged 3-15 years, is described for the first time. The 'filarial dance sign' (FDS), which indicates the presence of live adult worms, was observed in six children with microfilaraemia and in eight children who, though amicrofilaraemic, either had experienced an episode of lymphoedema (one) or were only positive for antifilarial IgG4 antibodies (seven). In bancroftian infection, the adult-worm nests have mostly been seen in asymptomatic but microfilaraemic subjects. The suspected worm nests, 18 in the 14 children, were all confirmed using colour-power and pulse-wave Doppler examinations. The worm nests were distinctly smaller and the wriggling movements were less rapid and less conspicuous than those seen in bancroftian filariasis. The importance of these findings in the management and control of lymphatic filariasis is discussed.
-
[
Ann Trop Med Parasitol,
2000]
Adult worms of Wuchereria bancrofti, or rather their characteristic movements (the 'filarial dance'), can now be detected in the scrotal lymphatics of microfilaraemic males, using ultrasonography. This ability has been used to delineate the lymphatic pathology of bancroftian filariasis, guide the surgical removal of the adult worms and, most importantly, assess the macrofilaricidal effects of antifilarial drugs. In the present study, the first report of the use of ultrasonography in brugian filariasis, 22 men (aged 18-62 years) with 60-2972 (median = 370) Brugia malayi microfilariae/ml blood were subjected to ultrasonography using a linear, 7.5-MHz probe. In addition, four other men (aged 19-35 years), with W. bancrofti microfilaraemia [28-524 (median = 234) microfilariae/ml], were similarly examined. Adult worms were not detectable in any of the patients with B. malayi parasitaemia but were detected in the scrotal lymphatics of two of the four individuals with W. bancrofti infection. The reasons for the failure to detect adult B. malayi and the limitations of ultrasound as a screening tool are examined. The results highlight the differences between the two species that cause most lymphatic filariasis and the need for rapid development of tools that can be used for the control of brugian lymphatic filariasis.
-
[
J Commun Dis,
2009]
Brugian filariasis prevalent mostly in South-East Asian countries including India contributes to a small but significant proportion of the socioeconomic burden due to lymphatic filariasis. Along with bancroftian filariasis, brugian filariasis has been targeted for elimination globally. The lack of a reliable daytime diagnostic test has been seen as an important barrier to the successful implementation and monitoring of elimination programmes in brugia endemic areas. We evaluated an anti-BmRI-IgG4 antibody test namely, 'Brugia Rapid' in a large study meant to understand the clinical and pathological manifestations of brugian filariasis in children. We found the test superior to traditional night blood screening for microfilaraemia. Although an antibody detection test, we found it to be a reliable indicator of brugian infection. Among the 100 children studied extensively, 94% of the microfilaraemics, 86% of those showing filarial dance sign indicating presence of, live adult worms and 78% having abnormal lymphatics on lymphoscintigraphy were IgG4 positive. Coupled with its advantages like ease of use any time of the day, high sensitivity and specificity, this test may be the ideal tool to assist programme managers in their efforts to eliminate lymphatic filariasis where brugian infections are found.
-
[
Sci Rep,
2018]
Filariasis is a global health problem targeted for elimination. Curative drugs (macrofilaricides) are required to accelerate elimination. Candidate macrofilaricides require testing in preclinical models of filariasis. The incidence of infection failures and high intra-group variation means that large group sizes are required for drug testing. Further, a lack of accurate, quantitative adult biomarkers results in protracted timeframes or multiple groups for endpoint analyses. Here we evaluate intra-vital ultrasonography (USG) to identify B. malayi in the peritonea of gerbils and CB.17 SCID mice and assess prognostic value in determining drug efficacy. USG operators, blinded to infection status, could detect intra-peritoneal filarial dance sign (ipFDS) with 100% specificity and sensitivity, when >5 B. malayi worms were present in SCID mice. USG ipFDS was predictive of macrofilaricidal activity in randomized, blinded studies comparing flubendazole, albendazole and vehicle-treated SCID mice. Semi-quantification of ipFDS could predict worm burden >10 with 87-100% accuracy in SCID mice or gerbils. We estimate that pre-assessment of worm burden by USG could reduce intra-group variation, obviate the need for surgical implantations in gerbils, and reduce total SCID mouse use by 40%. Thus, implementation of USG may reduce animal use, refine endpoints and negate invasive techniques for assessing anti-filarial drug efficacy.
-
[
Filaria J,
2005]
BACKGROUND: Ultrasonography (USG) is known to be a suitable tool for diagnosis in lymphatic filariasis as the adult filarial nematode Wuchereria bancrofti in scrotal lymphatic vessels of infected men can be detected by the characteristic pattern of movement, the Filaria Dance Sign. In onchocerciasis, moving adult worms have not yet been demonstrated by USG. In addition the verification of drug effects on living adult Onchocerca volvulus filariae in trials is hampered by the lack of tools for longitudinal observation of alterations induced by potentially macrofilaricidal drugs in vivo. The present study was carried out to determine the frequency of detection of moving adult filariae of O. volvulus by USG. METHODS: In an endemic region for onchocerciasis in Ghana, 61 patients infected with onchocerciasis were recruited by palpation and onchocercomas examined by USG using an ultrasound system equipped with a 7.5 - 10 MHz linear transducer. Onchocercomas were recorded on videotape and evaluated with regard to location, number and size, as well as to movements of adult filariae. RESULTS: In the 61 patients 303 onchocercomas were found by palpation and 401 onchocercomas were detected by USG. In 18 out of 61 patients (29.5%), altogether 22 nodules with moving adult O. volvulus filariae were detected and are presented in animated ultrasound images as mp-4 videos. CONCLUSION: Ultrasonographical examinations of onchocercomas where living adult filariae can be displayed may serve as a new tool for the longitudinal observation in vivo of patients with onchocerciasis undergoing treatment and as an adjunct to histological evaluation.
-
[
Ann Trop Med Parasitol,
2007]
As the more obvious clinical manifestations of the disease are very uncommon in children, lymphatic filariasis has been considered to be primarily a disease of adults. In many recent reports, however, there is evidence indicating not only that filarial infection is commonly acquired in childhood but also that many infected children already have irreversible damage to their lymphatics. The preliminary results of a cross-sectional study on the patterns of Brugia-attributable pathology in 7934 children (aged 3-15 years) who live in an area of India with endemic B. malayi infection confirm these trends. The children were screened for microfilaraemia, evidence of filarial disease, and the presence of antifilarial IgG(4) antibodies. One hundred children who were microfilaraemic but asymptomatic (32), with filarial disease or an history of such disease or microfilaraemia (29) or amicrofilaraemic and asymptomatic but seropositive for antifilarial IgG(4) (39) were investigated further. They were given detailed clinical examinations, their levels of microfilaraemia were evaluated (by counting microfilariae filtered out of blood samples), their lymphatics were explored by Doppler sonography, and their limbs were checked by lymphoscintigraphy. The 'filarial dance sign', which indicates the presence of live adult worms, was detected by sonography in 14 children (apparently the first time this sign has been observed in brugian filariasis). Lymphoscintigraphy revealed dilated lymphatic channels in the limbs of 80 of the children. At the end of the study, each of the 100 hospitalized children was treated with a single combined dose of diethylcarbamazine and albendazole; the aim is to follow-up the treated children every 6 months for 3 years. Even these preliminary results have important implications for filariasis-control programmes and emphasise the need for disability-alleviation efforts among children as well as adults.
-
[
MicroPubl Biol,
2019]
One barrier to communication at large face-to-face meetings, especially those focusing on scientific or technical topics, is a rapid way to understand what a person knows and thinks about before initiating a conversation. We have devised and reduced to practice an effective way to accomplish this task, the wearable microPoster.
In our experience, we observed that at most scientific meetings, especially once the number of participants passed 100, it is difficult to get productive conversations started with strangers. Thus, conversations tend to initiate among people that already know one another. This tends to exclude newer participants and those who do not have formal speaking slots. The difficulty increases at informal aspects of meetings: coffee breaks, lines for meals, social events, outdoor events in which a prominent speaker might have different clothes and sunglasses and is thus rendered unknown.
Poster sessions have long provided a venue for rapid communication and finding participants. These are usually the most productive parts of meetings. Our thinking evolved from jokes about sandwich board posters, in which one walks around with large posters on the front and back, to shirts with printed information. The advent of printed cloth posters provides a practical solution in which a microPoster is cut from the larger poster (ideally cloth), or printed on one or more sheets of standard paper, which are then taped together. A microPoster comprises your name, affiliation (with appropriate granularity determined by the meeting), and a graphical abstract. The goal is to identify yourself in a much more informative way than a nametag.
One convenient way to present the microPoster is pinned on your back like a bib number (e.g., as in marathons or dances). We carried out a pilot with ten microPosters at a meeting of 1500 people (Figure 1), and found them to be effective at attracting useful conversation.
The addition of a machine readable QR code (e.g., Salt, 2019) is a possible useful addition but we note that the expense in time, money and carbon footprint of a face-to-face meeting is better spent on face-to-face conversations.
-
Pennington PR, Heistad RM, Nyarko JNK, Barnes JR, Bolanos MAC, Parsons MP, Knudsen KJ, De Carvalho CE, Leary SC, Mousseau DD, Buttigieg J, Maley JM, Quartey MO
[
Sci Rep,
2021]
The pool of -Amyloid (A) length variants detected in preclinical and clinical Alzheimer disease (AD) samples suggests a diversity of roles for A peptides. We examined how a naturally occurring variant, e.g. A(1-38), interacts with the AD-related variant, A(1-42), and the predominant physiological variant, A(1-40). Atomic force microscopy, Thioflavin T fluorescence, circular dichroism, dynamic light scattering, and surface plasmon resonance reveal that A(1-38) interacts differently with A(1-40) and A(1-42) and, in general, A(1-38) interferes with the conversion of A(1-42) to a -sheet-rich aggregate. Functionally, A(1-38) reverses the negative impact of A(1-42) on long-term potentiation in acute hippocampal slices and on membrane conductance in primary neurons, and mitigates an A(1-42) phenotype in Caenorhabditis elegans. A(1-38) also reverses any loss of MTT conversion induced by A(1-40) and A(1-42) in HT-22 hippocampal neurons and APOE 4-positive human fibroblasts, although the combination of A(1-38) and A(1-42) inhibits MTT conversion in APOE 4-negative fibroblasts. A greater ratio of soluble A(1-42)/A(1-38) [and A(1-42)/A(1-40)] in autopsied brain extracts correlates with an earlier age-at-death in males (but not females) with a diagnosis of AD. These results suggest that A(1-38) is capable of physically counteracting, potentially in a sex-dependent manner, the neuropathological effects of the AD-relevant A(1-42).