Venous system mapping of the digits and the hand: An anatomical study and potential surgical applications.

Background: Venous anatomy of the digits and the hand is poorly reported in the literature compared to arterial anatomy. While knowledge of the venous anatomy is crucial to ensure safe skin incisions, skin flap design, or blood return restoration for digital replantations, data in anatomical and clinical textbooks are rather limited. The purpose of this anatomical study was to describe the venous anatomy of the digits and the hand. Method: Our series reports descriptive results from 10 non-embalmed hand dissections from 5 different corpses. Hands were previously co-injected by arteries followed by veins with a different colored latex before being dissected under optical magnification (x4). Each anatomical specimen was photographed before being analyzed. Results: Each injection revealed both arterial and venous vascular systems. Latex injections were a useful technique to show the dorsal, volar superficial, and deep venous system. There was a constant and reliable topographic vascular anatomy of the superficial venous system of the digits and hand. However, we could not observe a high density of dorsal superficial venous valves as previously reported. Conclusion: The knowledge of the arrangement of the venous system of the digits and the hand should help the surgeon when performing surgical procedures in the hand. The surgeon should take into consideration this venous anatomy when performing skin incisions, skin flaps, or replantation procedures which would preserve the normal venous physiology as much as possible.

Anatomy of the axillary arch: from its incidence in human to an embryologic and a phylogenetic explanation of its origins.

INTRODUCTION: Typically, the axillary arch is defined as a fleshy slip running from latissimus dorsi to the anterior aspect of the humerus. Phylogeny seems to give the most relevant and plausible explanation of this anatomical variant as a remnant of the panniculus carnosus. However, authors are not unanimous about its origin. We report herein the incidence of axillary arch in a series of 40 human female dissections and present an embryologic and a comparative study in three domestic mammals. MATERIALS AND METHODS: Forty formalin-preserved Caucasian human female cadavers, one rat (Rattus norvegicus), one rabbit (Oryctolagus cuniculus) and one pig (Sus scrofa domesticus) cadavers were dissected bilaterally. A comparative, analytical and a descriptive studies of serial human embryological sections were carried out. RESULTS: We found an incidence of axillary arch of 2.5% (n = 1 subject of 40) in Humans. We found a panniculus carnosus inserted on the anterior aspect of the humerus only in the rat and the rabbit but not in the pig. The development of the latissimus dorsi takes place between Carnegie stage 16-23, but the embryological study failed to explain the genesis of the axillary arch variation. However, comparative anatomy argues in favour of a panniculus carnosus origin of the axillary arch. CONCLUSIONS: With an incidence of 2.5% of cases, the axillary arch is a relatively frequent variant that should be known by clinician and especially surgeons. Moreover, while embryology seems to fail to explain the genesis of this variation, comparative study gives additional arguments which suggest a possible origin from the panniculus carnosus.

Predictive factors of success at the French National Ranking Examination (NRE): a retrospective study of the student performance from a French medical school.

BACKGROUND: The national ranking examination (NRE) marks the end of the second cycle (6th university year) of French medical studies and ranks students allowing them to choose their specialty and city of residency. We studied the potential predictive factors of success at the 2015 NRE by students attending a French School of Medicine. METHODS: From March 2016 to March 2017, a retrospective study of factors associated with the 2015 NRE success was conducted and enrolled 242 students who attended their sixth year at the school of medicine of Reims. Demographic and academic data collected by a home-made survey was studied using univariate and then multivariate analysis by generalized linear regression with a threshold of p <  0.05 deemed significant. RESULTS: The factors independently associated with a better ranking at the NRE were the motivation for the preparation of the NRE (gain of 3327 ± 527 places, p <  0.0001); to have participated in the NRE white test organized by la Revue du Praticien in November 2014 (gain of 869 ± 426 places, p <  0.04), to have participated in the NRE white test organized by la conférence Hippocrate in March 2015 (+ 613 places ±297, p <  0.04). The factors independently associated with poor NRE ranking were repeating the first year (loss of 1410 places ±286, p <  0.0001), repeating a year during university course (loss of 1092 places ±385, p <  0.005), attendance of hospital internships in 6th year (loss of 706 places ±298, p <  0.02). CONCLUSIONS: The student motivation and their white tests completion were significantly associated with success at the NRE. Conversely, repeating a university year during their course and attendance of 6th year hospital internships were associated with a lower ranking.

Anatomical variations of the subscapular pedicle and its terminal branches: an anatomical study and a reappraisal in the light of current surgical approaches.

PURPOSE: While anatomical variations of the subscapular vessels are frequently encountered during axillary dissection, little is found in the literature. The aim of this cadaveric study was to define arterial and venous anatomical variations and frequencies of the subscapular vascular pedicle and its terminal/afferent vessels in women. METHODS: We performed 80 dissections of the axillary region on forty female formalin-embalmed cadavers. Each anatomical arrangement was photographed and recorded on a scheme before analysis. RESULTS: We propose a new classification of the subscapular pedicle variations. We observed three types of subscapular arterial variation. The type Ia was the most frequent arrangement (71% of our dissections), the type Ib was observed in 11% and the type II in 18% of cases. We observed four types of subscapular venous variation. The type Ia was observed in 63% of cases, the type Ib in 14%, the type II in 14% and the type III in 10% of cases. CONCLUSIONS: This knowledge of the anatomical variation arrangement and frequencies of the subscapular vascular pedicle will assist the surgeon when dissecting the axillary region for malignant or reconstructive procedures.

Scan and Learn: Quick Response Code Enabled Museum for Mobile Learning of Anatomy and Pathology.

In the past, medical museums played a significant role in anatomy and pathology training. The attraction of medical museums has declined recently due to the emergence of information technology and innovative medical curricula. An innovative mobile learning platform has been developed using quick response (QR) codes for the museum specimens at the Lee Kong Chain School of Medicine, Singapore. High-quality images of the potted specimens were captured and combined into an album and a video using Adobe Acrobat Pro 9 and Windows Movie Maker, respectively. Subsequently, QR codes were generated linking to PDF documents with annotations, pathology, and clinical history concerning the specimens. Quick response codes were piloted in gastrointestinal teaching module for Year 2 medical students. Survey responses were obtained from students to verify the efficacy of QR as a learning tool. The majority of students either agreed or strongly agreed that it was easy to access the information about the specimen with QR codes (4.47 ± 0.84), while 96% of students agreed that they are able to correlate the specimen with the annotated images (4.56 ± 0.56). The majority of students (78%) agreed that QR codes are useful for their learning (4.22 ± 0.87), while 75% of students felt QR codes motivate them to visit Anatomy Resource Centre. Most of the students agreed that QR codes are useful for revision of materials (4.13 ± 1.07) and independent learning (4.38 ± 0.87). These findings suggest that QR codes are not only effective for students learning but also enhance their exploration experience with the museum specimens.

Evaluation by medical students of the educational value of multi-material and multi-colored three-dimensional printed models of the upper limb for anatomical education.

For centuries, cadaveric material has been the cornerstone of anatomical education. For reasons of changes in curriculum emphasis, cost, availability, expertise, and ethical concerns, several medical schools have replaced wet cadaveric specimens with plastinated prosections, plastic models, imaging, and digital models. Discussions about the qualities and limitations of these alternative teaching resources are on-going. We hypothesize that three-dimensional printed (3DP) models can replace or indeed enhance existing resources for anatomical education. A novel multi-colored and multi-material 3DP model of the upper limb was developed based on a plastinated upper limb prosection, capturing muscles, nerves, arteries and bones with a spatial resolution of ∼1 mm. This study aims to examine the educational value of the 3DP model from the learner's point of view. Students (n = 15) compared the developed 3DP models with the plastinated prosections, and provided their views on their learning experience using 3DP models using a survey and focus group discussion. Anatomical features in 3DP models were rated as accurate by all students. Several positive aspects of 3DP models were highlighted, such as the color coding by tissue type, flexibility and that less care was needed in the handling and examination of the specimen than plastinated specimens which facilitated the appreciation of relations between the anatomical structures. However, students reported that anatomical features in 3DP models are less realistic compared to the plastinated specimens. Multi-colored, multi-material 3DP models are a valuable resource for anatomical education and an excellent adjunct to wet cadaveric or plastinated prosections. Anat Sci Educ 11: 54-64. © 2017 American Association of Anatomists.

Human Anatomy in ancient Indian sculptures of Gandhara art illustrating the fasting Buddha

The present article intends to report the surface anatomical features in the three fasting Buddha sculptures and also tries to understand the anatomical knowledge of these ancient Indian sculptors by observing the digital images of the sculptures of the Gandhara art depicting the fasting Buddha. Close examination of the colour 2D digital photographs of the fasting Buddha which are available freely at Google Cultural Institute, the British Museum and the Metropolitan Museum web portals. Our observations demonstrate that the bones and joints of the thoracic cage, pectoral girdle, the extremities, particularly the upper limb, the skull and the pelvis were distinctly shown in the sculptures. Muscles of the neck (sternocleidomastoid, trapezius), shoulder (deltoid), thoracic cage (pectoralis major), limbs (arm and forearm), and anterior abdominal wall were clearly carved into the sculptures. The trachea was correctly placed in the neck. The boundaries of the axilla, and triangles of the neck were also clearly seen. Our observations demonstrate that ancient Indian artists of the Gandhara region had a basic knowledge of human anatomy, especially surface anatomy and musculoskeletal features. They also possessed knowledge of the approximate size and position of the bones, joints and muscles, including their approximate origin and insertion points. However, certain errors of anatomical knowledge including an extra number of ribs and a segmented sternum were noticed. Further, they also seemed to have some basic ideas about the physiological changes that occur during starving, as it is evident in the Buddha sculptures, which are skinny and emaciated

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Determining the best recipient vessel site for autologous microsurgical breast reconstruction with DIEP flaps: An anatomical study.

INTRODUCTION: The deep inferior epigastric perforator (DIEP) flap is a reliable and reproducible technique for autologous microsurgical breast reconstruction. Several recipient vessels sites for microvascular anastomosis have been described such as the internal thoracic vessels, the thoracodorsal vessels, and the circumflex scapular vessels. Nonetheless, the choice of the recipient site depends mainly on individual operator's experience and preferences, and currently the best recipient vessel site is under debate. This anatomical observational study aimed to determine whether anatomy could address this dilemma by determining the best vessel diameter to match the donor with these three recipient sites. METHODS: Our series reports 80 dissections of the three anatomical regions of interest. Forty formalin-preserved female cadavers were dissected bilaterally. Internal vessels diameter measurements were recorded with a vascular gauge ranging from 1.0 to 5.0 mm with successive half-millimeter graduations. RESULTS: The median diameter of the deep inferior epigastric (DIEA), internal thoracic (ITA), circumflex scapular (CSA), and thoracodorsal arteries (TDA) were: 2.0, 2.5, 2.5, and 1.5 mm, respectively. The median diameter of the deep inferior epigastric, internal thoracic, circumflex scapular, and thoracodorsal veins were: 3.0, 3.0, 3.0, and 2.5 mm, respectively. At the individual level, the perfect match between DIEA and ITA was significantly more frequent than between DIEA and TDA (p = 0.002), and it was more frequent between DIEA and CSA than between DIEA and TDA (p = 0.009). CONCLUSIONS: This study supports the use of the internal thoracic pedicle as the first recipient vessel choice, which should be considered, at least anatomically, as the best one with the closest diameter matching with the donor pedicle.

Anatomy, radiology, and practical procedure education for foundation doctors in England: A National Observational Study.

There are concerns regarding the anatomy knowledge amongst medical school graduates and foundation doctors. Clinical procedures performed without relevant anatomical knowledge could result in serious harm to patients. The aim of this quantitative study was to assess education provision in the domains of anatomy, radiology and practical procedures for foundation year doctors during their first two years of training (FY1, FY2). A national survey of acute hospital trusts in England was conducted. Each trust completed a proforma relating to education provision for foundation year doctors between 6/8/2014 and 4/8/2015. A total of 95/161 (59%) acute hospital trusts in England responded. The mean number of teaching hours/year was 55.6±19.0 for FY1 and 57.3±30.4 hours/year for FY2. Anatomy education was provided in eight trusts with a mean of 2.3±1.0 hours/year for FY1 and 2.7±2.0 hours/year for FY2. The mean provision of practical procedure education was 2.2±1.3 hours/year for FY1 and 2.7±4.4 hours/year for FY2. The mean provision of radiology education was 10.5±18.7 hours/year for FY1 and 7.8±14.2 hours/year for FY2. Reasons for the lack of teaching included: lack of time, facilities, teaching staff, financial resources and absence of specific educational domains in the foundation curriculum. Medical education provision for foundation doctors is highly variable. There are wide discrepancies in postgraduate anatomy education, procedural skill training and radiology education between hospital trusts. Clin. Anat. 29:982-990, 2016. © 2016 Wiley Periodicals, Inc.

"CoachPod": evaluation of an anatomy teaching podcast originally intended for learning anatomy on the move

Warwick Medical School (WMS) has no dissection facilities; students travelled by coach to the nearest medical school. The "CoachPod" is a series of podcasts designed to prepare students for dissection whilst travelling to dissection lab classes. Each podcast was filmed a week prior to each session and uploaded to the WMS website for students in the 2007 cohort (n=203). Evaluation was performed using a questionnaire with tickbox, Likert scale and free text questions. Overall response rate averaged 28%. Sixty-five percent watched the CoachPod on a computer, 34% watched it on an MP4 player, 55% viewed it at home, 31% viewed it on the coach, 26% watched each episode more than once, 83% perceived it as beneficial in aiding preparation, 51% felt the Coach was an appropriate learning environment, 90% felt they were of an appropriate length and that the anatomy was presented clearly, 89% believed the recordings were of adequate quality, 84% valued their tutors being in them, 92% enjoyed watching them, and 98% would value continued production. Suggestions for improvement were mostly on technical matters. CoachPod is considered a valuable dissection preparation tool, although it is mainly used at home and not on the move. Just-in-time preparation allowed subsequent incorporation of feedback

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The importance of ingested soils in supplying fluorine and lead to sheep grazing contaminated pastures in the Peak District mining area of Derbyshire, UK.

For sheep grazing pastures in areas of mineralisation and former metalliferous mining activity, an excessive intake of potentially harmful elements (PHEs) such as fluorine (F) and lead (Pb) can result in clinical and subclinical toxicity. The prime aim of our work was to calculate the intakes of both of these PHEs by sheep grazing pastures in the mineralised/mined Peak District area of Derbyshire. The bi-monthly sampling of topsoils (0-15 cm depth) and the faeces of sheep from fields at seven farms was undertaken for a 1-year period. These samples were analysed for titanium that allowed the rates of soil ingestion (and hence also herbage ingestion since we assume that the sheep have an overall diet of 1 kg dry matter (DM)/day) to be determined. Our findings were then combined with previously published soil and soil-free pasture herbage F and Pb concentrations determined from the seven farms to calculate the intakes of both PHEs. The results show seasonal variations of soil ingestion at the seven farms ranging from <0.1 to 20.1 % of the DM intake (median=3 %), with the highest rates of ingestion being associated with the winter-spring (i.e. December-April) period. Our calculations show that at some farms, sheep can be exposed to dietary concentrations in excess of recommended guidelines potentially throughout the whole year, though livestock movement to less-contaminated pastures would lessen any toxic impact. Because the soil concentrations are greater than those associated with soil-free pasture herbage, ingested soils are the main dietary source of Pb and (especially) F to sheep. However, subjecting freshly sampled topsoils to sequential extraction procedures undertaken in the laboratory indicates that the majority of Pb and (especially) F may not be readily soluble in the ovine digestion system, so reducing the quantities of both PHEs available for absorption.

Human geophagia, calabash chalk and undongo: mineral element nutritional implications.

The prime aim of our work is to report and comment on the bioaccessible concentrations - i.e., the soluble content of chemical elements in the gastrointestinal environment that is available for absorption - of a number of essential mineral nutrients and potentially harmful elements (PHEs) associated with the deliberate ingestion of African geophagical materials, namely Calabash chalk and Undongo. The pseudo-total concentrations of 13 mineral nutrients/PHEs were quantified following a nitric-perchloric acid digestion of nine different Calabash chalk samples, and bioaccessible contents of eight of these chemical elements were determined in simulated saliva/gastric and intestinal solutions obtained via use of the Fed ORganic Estimation human Simulation Test (FOREhST) in vitro procedure. The Calabash chalk pseudo-total content of the chemical elements is often below what may be regarded as average for soils/shales, and no concentration is excessively high. The in vitro leachate solutions had concentrations that were often lower than those of the blanks used in our experimental procedure, indicative of effective adsorption: lead, a PHE about which concern has been previously raised in connection with the consumption of Calabash chalk, was one such chemical element where this was evident. However, some concentrations in the leachate solutions are suggestive that Calabash chalk can be a source of chemical elements to humans in bioaccessible form, although generally the materials appear to be only a modest supplier: this applies even to iron, a mineral nutrient that has often been linked to the benefits of geophagia in previous academic literature. Our investigations indicate that at the reported rates of ingestion, Calabash chalk on the whole is not an important source of mineral nutrients or PHEs to humans. Similarly, although Undongo contains elevated pseudo-total concentrations of chromium and nickel, this soil is not a significant source to humans for any of the bioaccessible elements investigated.

Singapore's anatomical future: quo vadis?

The disciplines of anatomy and surgery are not dichotomous since one is dependent on the other. Traditionally, surgeons predominantly taught gross and clinical anatomy. In this review, we examine the context of how human anatomy is taught nowadays. In essence, we discovered that there are certain discernable trends consistently observable between the American and British systems. In Singapore, the British Russell Group first influenced its education landscape but now more so by the American Ivy League. Singapore now has three medical schools all offering differing anatomy curricula, which serves as an opportune time for it to consider if there is a best approach given that the practice of surgery is also evolving in parallel. This review discusses the various pedagogies and issues involved, and will serve as a forum and stimulus for discussion. By tweaking the curriculum correctly and the lessons learnt, future doctors and surgeons in training will receive a better anatomical education, not just in Singapore but the world in general. Key recommendations include the use of body painting, clay, plasticine to facilitate the learning of anatomy, and the implementation of a body donation program. Furthermore, strategic mergers with key stakeholders will also ensure the survival of the discipline.

A novel technique for teaching the brachial plexus.

BACKGROUND: The brachial plexus has posed problems for both students and teachers throughout generations of medical education. The anatomy is intricate, and traditional pictorial representations can be difficult to understand and learn. Few innovative teaching methods have been reported. CONTEXT: The basic anatomy of the brachial plexus is core knowledge required by medical students to aid clinical examination and diagnosis. A more detailed understanding is necessary for a variety of specialists, including surgeons, anaesthetists and radiologists. INNOVATION: Here, we present a novel, cheap and interactive method of teaching the brachial plexus. Using coloured pipe cleaners, teachers and students can construct three-dimensional models using different colours to denote the origin and outflow of each nerve. The three-dimensional nature of the model also allows for a better understanding of certain intricacies of the plexus. Students may use these models as adjuncts for self study, didactic lectures and tutorials. IMPLICATIONS: Compared with traditional textbooks and whiteboards, the pipe-cleaner model was preferred by medical students, and provided a higher level of student satisfaction. This was demonstrated and analysed using student feedback forms. Our model could be incorporated into current curricula to provide an effective and enjoyable way of rapidly teaching a difficult concept. Other such novel methods for teaching complex anatomical principles should be encouraged and explored.

Surgery in early Jewish history.

The Hebrew writings in early history are dedicated primarily to the explanations and elucidations of Jewish law. In the context of such laws, several medical and anatomical references are made that provide some clues to the medical practices of the day. In particular, this article serves to compile references made to surgical interventions within these texts. Particular attention is paid to the possible use of anesthetics, the environment and equipment utilized in surgery, as well as the indication of knowledge of infection and hygienic practices. An understanding of human morphology was necessary for many of these surgical practices.

A three-year prospective longitudinal cohort study of medical students' attitudes toward anatomy teaching and their career aspirations.

Today's medical students are faced with numerous learning needs. Continuously developing curricula have reduced time for basic science subjects such as anatomy. This study aimed to determine the students' views on the relevance of anatomy teaching, anatomical knowledge, and the effect these have on their career choices. A Likert scale questionnaire was distributed to second year medical students [response rate 91% (n = 292/320)]. The same questionnaire was subsequently distributed to the cohort three years later when they were final year students [response rate 37% (n = 146/392)]. Students in both the cohorts of study agreed strongly that clinically correlated anatomical teaching was relevant to clinical practice (92% and 86% of second and final year respondents, respectively) and helped them during their clinical placements (73% and 92%, respectively). Only 28% of the second year and 31% of the final year students agreed that their anatomy teaching prepared them to interpret clinical images (P = 0.269). Only 14% of the final year students felt confident in their knowledge of anatomy. Of the final year students, 30% felt that they had enough opportunity to scrub in the operating room. Nearly half of those students who would consider surgery as a career (19%) think that they will eventually become surgeons (11%). This data suggests that modern anatomy curriculum should focus on clinical correlations and clinical image interpretation. Students would value more opportunities to participate in surgeries. Vertical integration of anatomy teaching throughout the full medical course may be useful.

The anatomy of anatomy: a review for its modernization.

Anatomy has historically been a cornerstone in medical education regardless of nation or specialty. Until recently, dissection and didactic lectures were its sole pedagogy. Teaching methodology has been revolutionized with more reliance on models, imaging, simulation, and the Internet to further consolidate and enhance the learning experience. Moreover, modern medical curricula are giving less importance to anatomy education and to the acknowledged value of dissection. Universities have even abandoned dissection completely in favor of user-friendly multimedia, alternative teaching approaches, and newly defined priorities in clinical practice. Anatomy curriculum is undergoing international reformation but the current framework lacks uniformity among institutions. Optimal learning content can be categorized into the following modalities: (1) dissection/prosection, (2) interactive multimedia, (3) procedural anatomy, (4) surface and clinical anatomy, and (5) imaging. The importance of multimodal teaching, with examples suggested in this article, has been widely recognized and assessed. Nevertheless, there are still ongoing limitations in anatomy teaching. Substantial problems consist of diminished allotted dissection time and the number of qualified anatomy instructors, which will eventually deteriorate the quality of education. Alternative resources and strategies are discussed in an attempt to tackle these genuine concerns. The challenges are to reinstate more effective teaching and learning tools while maintaining the beneficial values of orthodox dissection. The UK has a reputable medical education but its quality could be improved by observing international frameworks. The heavy penalty of not concentrating on sufficient anatomy education will inevitably lead to incompetent anatomists and healthcare professionals, leaving patients to face dire repercussions.

An unusual anatomical explanation for contralateral upper extremity weakness after frontal craniotomy.

Contralateral upper extremity weakness following resection of a frontal tumor is not unusual to neurosurgeons. The differential diagnosis is broad and includes postoperative brachial plexopathy, which is usually secondary to malpositioning. We report the first known case of postoperative brachial plexopathy secondary to sialadenitis. A 53-year-old woman who had undergone an uncomplicated right frontal craniotomy for resection of a right frontal metastatic lesion developed left upper extremity weakness as well as extensive left neck edema immediately postoperatively. The edema, tracking along the fascial plane of the neck, caused compression of the upper (more superficial) elements of the brachial plexus and ensuing plexopathy. The cause of the neck edema was found to be sialadenitis of the submandibular gland. With medical treatment, the edema slowly resolved and the patient regained full function of her left upper extremity within weeks. This unusual case represents a new etiology of postoperative brachial plexopathy, illustrates the clinical relevance of the anatomy of the neck fasciae, and broadens the differential diagnosis of contralateral weakness following craniotomy for resection of a brain tumor.

Abnormal kinetics of induction of UV-stimulated recombination in human DNA repair disorders.

Recombination can result in genetic instability, and thus constitutes an important factor in the carcinogenic conversion of mammalian cells. Here we describe the occurrence of UV-stimulated recombination called enhanced recombination (EREC), measured with the use of Herpes Simplex Viruses type 1 mutants. In normal diploid human cells, EREC is induced by UV-C, mitomycin C and ENU, but not by X-ray or MMS. The kinetics of induction of EREC is similar to that of other SOS-like responses such as enhanced reactivation (ER) and enhanced mutagenesis (EM). In contrast to the latter responses, EREC is induced to higher levels and persists for longer periods in DNA repair deficient fibroblasts derived from xeroderma pigmentosum (XP), Cockayne syndrome (CS) and Trichothiodystrophy (TTD) patients. This observation indicates that EREC is a distinct SOS-like response. Apparently, the presence of unrepaired DNA lesions in the host genome is a strongly inducing signal for EREC. On the other hand, in cells derived from patients suffering from Bloom, Werner or Rothmund-Thomson syndrome (RTS) the EREC response is absent. These data indicate that determining EREC is a useful assay to investigate diploid human fibroblasts for abnormalities in UV-stimulated recombination.

Soil ingestion by sheep grazing the metal enriched floodplain soils of mid-Wales.

Floodplain soils within and downstream from the mineralised and mined areas of mid-Wales, are contaminated by metals, especially Pb, because of historical and contemporary fluvial pollution. Rates of soil ingestion by sheep grazing these sites have been quantified to establish the relative importance of the soil-plant-animal and soil-animal pathway of metals. The highest rates of soil ingestion occurred during the winter/spring period. During March, soil ingestion exceeded 30% of the D.M. intake at 2 of the 11 sites investigated. The total daily intake of metals by sheep reflects the degree of soil metal enrichment, and is elevated during the winter/spring period, coincident with the higher rates of soil ingestion and the generally higher pasture herbage metal concentrations. Because the soil-plant transfer of Pb is low, ingested soil is often the major pathway of this metal to sheep. This is especially evident in March and May when on average 80.0 and 82.9%, respectively of the Pb intake was via soil ingestion. At one site in May, 97% of the Pb intake was attributable to ingested soil. Even when soil-plant transfers are not so low, as found for Cu and Zn, ingested soil can occasionally supply greater than 60% of these metals to the animal. However, despite the potential importance of soil ingestion, little is known about the availability to and absorption of soil-borne metals by animals.