Studies on the hyperplasia ('regeneration') of the rat liver following partial hepatectomy. Changes in lipid peroxidation and general biochemical aspects

Using the experimental model of partial hepatectomy in the rat, we have examined the relationship between cell division and lipid peroxidation activity. In rats entrained to a regime of 12 h light/12 h dark and with a fixed 8 h feeding period in the dark phase, partial hepatectomy is followed by a rapid regeneration of liver mass with cycles of synchronized cell division at 24 h intervals. The latter phenomenon is indicated in this study by pulses of thymidine kinase activity having maxima at 24 h, 48 h and 72 h after partial hepatectomy. Microsomes prepared from regenerating livers show changes in lipid peroxidation activity (induced by NADPH/ADP/iron or by ascorbate/iron), which is significantly decreased relative to that in microsomes from sham-operated controls, again at 24 h, 48 h and 72 h after the operation. This phenomenon has been investigated with regard to possible underlying changes in the content of microsomal fatty acids, the microsomal enzymes NADPH:cytochrome c reductase and cytochrome P-450, and the physiological microsomal antioxidant alpha-tocopherol. The cycles of decreased lipid peroxidation activity are apparently due, at least in part, to changes in microsomal alpha-tocopherol content that are closely associated in time with thymidine kinase activity

New imaging markers for preconceptional and first-trimester utero-placental vascularization

Introduction: The availability of imaging makers of early placental circulation development is limited. This study aims to develop a reliable and accurate method to assess preconceptional and early first-trimester utero-placental vascular volumes using three-dimensional power Doppler ultrasound (3D PD US) on two different Virtual Reality (VR) systems. Methods: 3D PD US images of the uterine and placental vasculature were obtained in 35 women, either preconceptionally (n=5), or during pregnancy at 7 (n=10), 9 (n=10) or 11 (n=10) weeks of gestation. Preconceptional uterine vascular volume (UVV), and first-trimester placental vascular volume (PVV) and embryonic vascular volume (EVV) were measured by two observers on two VR systems, i.e., a Barco I-Space and VR desktop. Intra- and inter-observer agreement and intersystem agreement were assessed by intra-class correlation coefficients (ICC) and absolute and relative differences. Results: Uterine- , fetal- and placental vascular volume measurements showed good to excellent intra- and inter-observer agreement and inter-system reproducibility with most ICC above 0.80 and relative differences of less than 20% preconceptionally and almost throughout the entire gestational age range. Inter-observer agreement of PVV at 11 weeks gestation was suboptimal (ICC 0.69, relative difference 50.1%). Discussion: Preconceptional and first-trimester 3D PD US utero-placental and fetal vascular volume measurements using VR are feasible and reliable. Longitudinal cohort studies with repeated measurements are needed to further validate these this and assess their value as new imaging markers for placental vascular development and ultimately for the prediction of placenta-related pregnancy complications.This research was funded by the Department of Obstetrics and Gynecology of the Erasmus MC, University Medical Centre, Rotterdam, The Netherlands

Clearing the Backlog: Trichiasis Surgeon Retention and Productivity in Northern Ethiopia

Blindness from trachoma is caused by the abrasive effect of trichiasis (in-turned eyelashes). Surgery is performed to correct this anatomical abnormality, and prevent blindness. Despite the progress made in many regions in controlling the active/infectious stages of this disease, the global prevalence of trichiasis remains about the same. Current surgical activity is barely keeping abreast of incident trichiasis; this is undermining all the other efforts to control trachoma. We examine staff retention and productivity in Amhara Region, Ethiopia, where many hundreds of health care workers have been trained to perform the surgery. We found that the majority of people trained to do the surgery are now not in a position to do so. Amongst the sub-set that is still active within the programme, surgical productivity is low, with most surgery performed during “outreach campaigns” Insufficient surgical instruments and consumables were frequent problems. Strengthened health-systems management can overcome many of the problems that are holding back the delivery of an effective trichiasis surgical service

Searching for faces differs from categorization: Evidence from scenes and eye movements

This study examined whether the detection of frontal, ¾ and profile face views differs from their categorization as faces. Experiment 1 compared three tasks that required observers to determine the presence or absence of a face but varied in the extent to which they had to search for faces in simple displays and small or large scenes to make this decision. Performance was equivalent for all face views in simple displays and small scenes, but was notably slower for profile views when this required the search for faces in extended scene displays. This search effect was confirmed in Experiment 2, which compared observers’ eye movements with their response times to faces in visual scenes. These results demonstrate that the categorization of faces at fixation is dissociable from the detection of faces in space. Consequently, we suggest that face detection should be studied with extended visual displays, such as natural scenes

Profound and Sustained Reduction in Chlamydia trachomatis in The Gambia: A Five-Year Longitudinal Study of Trachoma Endemic Communities

Trachoma is the most common infectious cause of blindness worldwide. Mass antibiotic treatment with azithromycin is used to control ocular Chlamydia trachomatis infection. There is uncertainty over how frequently and for how long treatment is needed, particularly in low prevalence settings. This study examines the effect of a single round of treatment on clinical disease and infection in a cluster of trachoma endemic Gambian villages over a five-year period. These villages had good water supplies and sanitation improved part way through the study. We found treatment was followed by a marked decline in infection prevalence (by PCR) to less than 1%. The decline in prevalence of active disease in children was less marked. Several villages had a prevalence of active trachoma in 1 to 9 year old children of greater than 10% during the follow-up period, mostly in the absence of detectable infection. The implication of this study is that a single, high coverage mass treatment may be sufficient to control C. trachomatis infection in a low prevalence setting, particularly when combined with environmental measures to limit transmission. However, relying on clinical signs to guide treatment decisions is likely to lead to significant amounts of over treatment where current guidelines are implemented

The Global Burden of Trachoma: A Review

Trachoma is the commonest infectious cause of blindness worldwide. Recurrent infection of the ocular surface by Chlamydia trachomatis, the causative agent, leads to inturning of the eyelashes (trichiasis) and blinding corneal opacification. Trachoma is endemic in more than 50 countries. It is currently estimated that there are about 1.3 million people blind from the disease and a further 8.2 million have trichiasis. Several estimates for the burden of disease from trachoma have been made, giving quite variable results. The variation is partly because different prevalence data have been used and partly because different sequelae have been included. The most recent estimate from the WHO placed it at around 1.3 million Disability-Adjusted Life Years (DALYs). A key issue in producing a reliable estimate of the global burden of trachoma is the limited amount of reliable survey data from endemic regions

A gene-based SNP resource and linkage map for the copepod Tigriopus californicus

<p>Abstract</p> <p>Background</p> <p>As yet, few genomic resources have been developed in crustaceans. This lack is particularly evident in Copepoda, given the extraordinary numerical abundance, and taxonomic and ecological diversity of this group. <it>Tigriopus californicus </it>is ideally suited to serve as a genetic model copepod and has been the subject of extensive work in environmental stress and reproductive isolation. Accordingly, we set out to develop a broadly-useful panel of genetic markers and to construct a linkage map dense enough for quantitative trait locus detection in an interval mapping framework for <it>T. californicus--</it>a first for copepods.</p> <p>Results</p> <p>One hundred and ninety Single Nucleotide Polymorphisms (SNPs) were used to genotype our mapping population of 250 F₂larvae. We were able to construct a linkage map with an average intermarker distance of 1.8 cM, and a maximum intermarker distance of 10.3 cM. All markers were assembled into linkage groups, and the 12 linkage groups corresponded to the 12 known chromosomes of <it>T. californicus</it>. We estimate a total genome size of 401.0 cM, and a total coverage of 73.7%. Seventy five percent of the mapped markers were detected in 9 additional populations of <it>T. californicus</it>. Of available model arthropod genomes, we were able to show more colocalized pairs of homologues between <it>T. californicus </it>and the honeybee <it>Apis mellifera</it>, than expected by chance, suggesting preserved macrosynteny between Hymenoptera and Copepoda.</p> <p>Conclusions</p> <p>Our study provides an abundance of linked markers spanning all chromosomes. Many of these markers are also found in multiple populations of <it>T. californicus</it>, and in two other species in the genus. The genomic resource we have developed will enable mapping throughout the geographical range of this species and in closely related species. This linkage map will facilitate genome sequencing, mapping and assembly in an ecologically and taxonomically interesting group for which genomic resources are currently under development.</p

Surgery versus epilation for the treatment of minor trichiasis in Ethiopia: a randomised controlled noninferiority trial.

Trachomatous trichiasis can cause corneal damage and visual impairment. WHO recommends surgery for all cases. However, in many regions surgical provision is inadequate and patients frequently decline. Self-epilation is common and was associated with comparable outcomes to surgery in nonrandomised studies for minor trichiasis (<six lashes touching eye). This trial investigated whether epilation is noninferior to surgery for managing minor trichiasis

Successful myomectomy during pregnancy : A case report

BACKGROUND: The medical literature has reported an increase in myomectomy during caesarean section in the past decade. However, myomectomy performed during pregnancy remains a rarity. The management of uterine fibroids during pregnancy is usually expectant and surgical removal is generally delayed until after delivery. We present a case of a large, symptomatic uterine fibroid diagnosed during pregnancy which was successfully managed by antepartum myomectomy. CASE PRESENTATION: A 30 year old woman presented with a one year history of abdominal swelling, amenorrhea and severe epigastric discomfort of 19 weeks duration. The abdomen was grossly distended and tense. A sonographic diagnosis of ovarian tumor in pregnancy was made. Laparotomy revealed a 32 cm degenerating subserosal uterine fibroid co-existing with an intrauterine pregnancy. Myomectomy was successfully performed. The subsequent antenatal period was uneventful with a spontaneous vaginal delivery of a female baby at 38 weeks. CONCLUSION: This report supports other studies and case series that have demonstrated the safety of myomectomy during pregnancy in selected circumstances

Elimination of Active Trachoma after Two Topical Mass Treatments with Azithromycin 1.5% Eye Drops

Trachoma is the leading cause of infectious blindness worldwide, accounting for 1.3 million cases of blindness. Although it has disappeared in many regions of the world, trachoma is still endemic in Africa, Eastern Mediterranean, Latin America, Asia, and Australia. The WHO has currently set a target of 2020 for controlling trachoma to a low enough level that resulting blindness will not be a major public health concern. Topical tetracycline was for a long time the recommended treatment for active trachoma, but compliance to the regimen is extremely poor. Azithromycin has properties that make it an ideal treatment for Chlamydia trachomatis: high efficacy, intracellular accumulation, and a long tissue half-life. There is now a new mass treatment of trachoma by azithromycin 1.5% eye drops which is as effective as the oral route. In the test health district of Kolofata, Cameroon, the prevalence of trachoma among children dramatically decreased from 31% to less than 5% after 2 treatments. A third treatment was performed in January 2010. An epidemiological surveillance is implemented to see if this removal will be permanent. It also avoids misuse of oral azithromycin and the eye drops are directly treating the site of the infection