Cryptic lineage differentiation among Indo-Pacific bottlenose dolphins (Tursiops aduncus) in the northwest Indian Ocean.

Phylogeography can provide insight into the potential for speciation and identify geographic regions and evolutionary processes associated with species richness and evolutionary endemism. In the marine environment, highly mobile species sometimes show structured patterns of diversity, but the processes isolating populations and promoting differentiation are often unclear. The Delphinidae (oceanic dolphins) are a striking case in point and, in particular, bottlenose dolphins (Tursiops spp.). Understanding the radiation of species in this genus is likely to provide broader inference about the processes that determine patterns of biogeography and speciation, because both fine-scale structure over a range of kilometers and relative panmixia over an oceanic range are known for Tursiops populations. In our study, novel Tursiops spp. sequences from the northwest Indian Ocean (including mitogenomes and two nuDNA loci) are included in a worldwide Tursiops spp. phylogeographic analysis. We discover a new 'aduncus' type lineage in the Arabian Sea (off India, Pakistan and Oman) that diverged from the Australasian lineage ∼261 Ka. Effective management of coastal dolphins in the region will need to consider this new lineage as an evolutionarily significant unit. We propose that the establishment of this lineage could have been in response to climate change during the Pleistocene and show data supporting hypotheses for multiple divergence events, including vicariance across the Indo-Pacific barrier and in the northwest Indian Ocean. These data provide valuable transferable inference on the potential mechanisms for population and species differentiation across this geographic range.

Strong population structure in a species manipulated by humans since the Neolithic: the European fallow deer (Dama dama dama).

Species that have been translocated and otherwise manipulated by humans may show patterns of population structure that reflect those interactions. At the same time, natural processes shape populations, including behavioural characteristics like dispersal potential and breeding system. In Europe, a key factor is the geography and history of climate change through the Pleistocene. During glacial maxima throughout that period, species in Europe with temperate distributions were forced south, becoming distributed among the isolated peninsulas represented by Anatolia, Italy and Iberia. Understanding modern patterns of diversity depends on understanding these historical population dynamics. Traditionally, European fallow deer (Dama dama dama) are thought to have been restricted to refugia in Anatolia and possibly Sicily and the Balkans. However, the distribution of this species was also greatly influenced by human-mediated translocations. We focus on fallow deer to better understand the relative influence of these natural and anthropogenic processes. We compared modern fallow deer putative populations across a broad geographic range using microsatellite and mitochondrial DNA loci. The results revealed highly insular populations, depauperate of genetic variation and significantly differentiated from each other. This is consistent with the expectations of drift acting on populations founded by small numbers of individuals, and reflects known founder populations in the north. However, there was also evidence for differentiation among (but not within) physically isolated regions in the south, including Iberia. In those regions we find evidence for a stronger influence from natural processes than may be expected for a species with such strong, known anthropogenic influence.

Ancient and modern DNA track temporal and spatial population dynamics in the European fallow deer since the Eemian interglacial.

Anthropogenic factors have impacted the diversity and evolutionary trajectory of various species. This can be through factors such as pressure on population size or range, habitat fragmentation, or extensive manipulation and translocation. Here we use time-calibrated data to better understand the pattern and processes of evolution in the heavily manipulated European fallow deer (Dama dama). During the Pleistocene, fallow deer had a broad distribution across Europe and were found as far north as Britain during the Eemian interglacial. The last glacial period saw fallow deer retreat to southern refugia and they did not disperse north afterwards. Their recolonisation was mediated by people and, from northern Europe and the British Isles, fallow deer were transported around the world. We use ancient and modern mitochondrial DNA (mtDNA) and mitogenomic data from Eemian Britain to assess the pattern of change in distribution and lineage structure across Europe over time. We find founder effects and mixed lineages in the northern populations, and stability over time for populations in southern Europe. The Eemian sample was most similar to a lineage currently in Italy, suggesting an early establishment of the relevant refuge. We consider the implications for the integration of anthropogenic and natural processes towards a better understanding of the evolution of fallow deer in Europe.

Joint practice guidelines for radionuclide lymphoscintigraphy for sentinel node localization in oral/oropharyngeal squamous cell carcinoma.

Involvement of the cervical lymph nodes is the most important prognostic factor for patients with oral/oropharyngeal squamous cell carcinoma (OSCC), and the decision of whether to electively treat patients with clinically negative necks remains a controversial topic. Sentinel node biopsy (SNB) provides a minimally invasive method for determining the disease status of the cervical node basin, without the need for a formal neck dissection. This technique potentially improves the accuracy of histologic nodal staging and avoids overtreating three-quarters of this patient population, minimizing associated morbidity. The technique has been validated for patients with OSCC, and larger-scale studies are in progress to determine its exact role in the management of this patient population. This document is designed to outline the current best practice guidelines for the provision of SNB in patients with early-stage OSCC, and to provide a framework for the currently evolving recommendations for its use. Preparation of this guideline was carried out by a multidisciplinary surgical/nuclear medicine/pathology expert panel under the joint auspices of the European Association of Nuclear Medicine (EANM) Oncology Committee and the Sentinel European Node Trial (SENT) Committee.

Clinical imaging with indium-111 leukocytes: uptake in bowel infarction.

Leukocytes labeled with indium-111 accumulated in are area of small-bowel infarction, mimicking a paracolic abscess. Evidence of subacute bowel obstruction should alert the nuclear medicine physician to the former possibility.

The "hot patella" sign: is it of any clinical significance? Concise communication.

The presence of the "hot patella" sign was evaluated in a prospective study of 200 consecutive bone scans, and in a review of scans from 148 patients with various metabolic bone disorders and 61 patients with lung carcinoma. The incidence was found to be 31%, 26% and 31% respectively. This sign is an extremely common scan finding and may be seen in association with a wide variety of disorders. It is concluded that this sign cannot be considered to be of diagnostic value.

A quantitative study of leukocyte cohesion: effects of divalent cations and pH.

Leukocyte cell-to-cell adhesion was studied with a cell monolayer technique. The amount of protein retained on the coverslip reflected the number of adhering cells. When polymorphonuclear leukocytes were suspended in a balanced salt solution at neutral pH containing no bivalent cations, they adhered to the glass surface but not to each other. Magnesium or calcium at concentrations above 1 mM caused cell-to-cell adhesion. Stannous and chromate ions had no effect on leukocyte cell-to-cell adhesion. Acid pH also induced leukocyte aggregation. This last effect could be reversed by washing the cells with a balanced salt solution at neutral pH, but it could not be reversed by alcohol.

Hyperinsulinism associated with primary renal cell carcinoma.

A case is reported of a patient with symptomatic hyperinsulinism associated initially with a renal cell carcinoma and then later, with secondary deposits from the same tumor. Evidence points to a strong possibility of renal tumor involvement in the production of insulin hypersecretion.

A comparison of computed tomography, ultrasound and scintigraphy in the diagnosis of alcoholic liver disease.

In 35 alcoholics with histologically proven liver disease, computed tomography (CT), grey scale ultrasonography and liver scintigraphy were evaluated for their abilities to detect an abnormal liver and to identify the patients with cirrhosis. Abnormal studies were present on CT in 83% of patients, in 64% on ultrasound and in 94% on scintigraphy. In 10 control patients specificity was 90% by CT, 100% by ultrasound and 70% by scintigraphy. CT and ultrasound were poor in identifying the alcoholics with cirrhosis. Scintigraphy suggested cirrhosis in all but one of the patients with this diagnosis. Similar images were obtained in half of the patients with fatty change without cirrhosis but, with the exception of one patient, this appeared to be due to co-existent hepatitis. The results suggest that scintigraphy is the best of the imaging tests for screening alcoholics for cirrhosis.

The ability of lymphoscintigraphy to direct sentinel node biopsy in the clinically N0 neck for patients with head and neck squamous cell carcinoma.

This study aimed to evaluate the ability of lymphoscintigraphy (LSG) to direct sentinel node biopsy (SNB) in the identification of occult metastases in the clinically N0 neck for patients with head and neck squamous cell carcinoma (HNSCC). 57 clinically N0 neck sides in 48 patients were assessed using the triple diagnostic approach of pre-operative LSG, intra-operative use of a gamma probe and blue dye. SNB was performed after radiocolloid and blue dye injection. Pre-operative LSG and the intra-operative use of a gamma probe identified radioactive sentinel nodes, and visualization of blue stained lymphatics identified blue sentinel nodes. 104 sentinel nodes were harvested from 43 patients. The identification rate was 90% (43 of 48). Of the 104 nodes harvested, 17 of 62 (27%) nodes identified as both radioactive and blue were positive for occult metastases compared with 5 of 42 (12%) nodes identified as hot or blue only (p<0.05). Sentinel nodes were identified in 39 of 48 (81%) patients using LSG. Of 39 patients in whom sentinel nodes were identified using LSG, 37 of 39 (95%) had radioactive sentinel nodes harvested intra-operatively. In patients who had no sentinel nodes identified on LSG, 4 of 9 (44%) had radioactive sentinel nodes harvested intra-operatively. This difference was statistically significant using the t-test (p<0.05). LSG directs SNB and is essential in the identification of occult metastases within the clinically N0 neck for patients with HNSCC.

Gallbladder visualization in 99Tcm-HMPAO autologous white cell scintigraphy.

The appearance of the gallbladder in images of patients undergoing 99Tcm-hexamethylpropylene amine oxime (99Tcm-HMPAO) autologous white cell scans (AWCSs) was compared before and after the introduction of fasting in the white cell scan protocol in our department. Before February 1995, when fasting was not required as a condition of the test, gallbladders were identified in 10 and 13% of 128 patients at 1 and 3 h, respectively. After February 1995, when fasting was imposed for the duration of the AWCS procedure, gallbladders were identified in 44 and 58% of 139 patients undergoing an AWCS at 1 and 3 h, respectively (P < 0.01). While further studies are required to show that fasting affects the false-positive rate, the results suggest that the degradation products of 99Tcm-HMPAO may be retained in the biliary system longer during fasting. Fasting should therefore be included in the protocol for an AWCS, particularly in the evaluation of inflammatory bowel disease (IBD) when 99Tcm-HMPAO is the cell label used.

Nuclear medicine and radionuclide imaging: a survey of recruitment issues in the United Kingdom.

This wide ranging survey has highlighted difficulties in recruiting trained and committed individuals into nuclear medicine and radionuclide radiology. Several key factors have been recognised that reduce the attractiveness of the training. Recommendations include the rotation of medical senior house officers through nuclear medicine, reconsideration of dual accreditation in nuclear medicine and medicine, an increase in the number of consultant posts in nuclear medicine, parity of remuneration for nuclear medicine trainees and finally, an appropriate sessional provision for those providing radionuclide radiology services.

Lung scan reporting language: what does it mean?

The aim of this study was to analyse the understanding of the verbal probability language used for communicating lung scan findings. A questionnaire providing a series of expressions of probability in lung scan reporting was sent to 211 consultant nuclear medicine providers in the UK. Respondents were asked to estimate the probability of pulmonary embolism (PE) communicated by each reporting expression on a visual linear probability scale. Analysis of 135 replies revealed a wide variation in the interpretation of the probability language. We suggest that different training, the nature of the probability scale itself and the difficulties of expressing a verbal report on a numerical scale are major reasons for this finding. We conclude that use of verbal probability language complicates the communication of PE risk and that likelihood ratios provide a logical alternative.

Lung scan reports: interpretation by clinicians.

A questionnaire was sent to 217 consultant physicians in Scotland who were likely to encounter pulmonary embolism (PE) in their daily practice. Replies were received from 194 (89%). Only 34% of physicians understood that a normal lung scan made PE highly unlikely, while 65% considered a low probability scan equivalent to an uncertain diagnosis. This pattern of interpretation of lung scan reports was confirmed by a question on post-test management. After a normal lung scan report, 31% of physicians were uncertain about the diagnosis and this uncertainty increased to 37% for a low probability scan report. This survey has shown misunderstanding by a significant number of physicians of the risk of PE indicated by normal and low probability lung scan reports. It underlines the need for individuals reporting the test to provide informed guidance for clinical staff following ventilation/perfusion (V/Q) imaging. It may point in addition to a need for a more easily understood style of reporting of lung scans.

A preliminary evaluation of diagnostic odds in lung scan reporting.

Reporting of lung scans for pulmonary embolism (PE) using a descriptive probability notation is tried and tested. Subjectivity in interpretation of this jargon can be a problem for internists. Parallel descriptive and numerical probability reporting has been recommended, but the numerical probability scale is less precise than likelihood ratios expressed as odds. We therefore assessed internists' intuitive understanding of lung scan reports in the odds format compared to the descriptive probability notation. A questionnaire was sent to Scotland's 217 internists to assess their intuitive understanding of odds reporting and to compare their management strategies when confronted by lung scan reports in both an odds and a descriptive probability notation. There was a broad understanding of numerical odds. Internists used 'normal' and '100:1 against PE' identically; similarly, 'low probability' and '10:1 against PE'. There was a statistically significant preference for the diagnosis of PE when internists were given the '1:1 evens' report compared with the 'indeterminate' report. There does appear to be a greater awareness of the risk of PE when non-diagnostic lung scans are reported in numerical odds as compared with the descriptive probability format.

Vertebral metastases and an equivocal bone scan: value of magnetic resonance imaging.

To assess the value of magnetic resonance imaging (MRI) in the investigation of patients with suspected but nonproven vertebral metastases 45 consecutive patients referred in a 6 month period with known primary malignancy and back pain in whom an isotope bone scan was reported as equivocal were studied. All patients had abnormal isotope uptake localized to the spine. Twelve patients were shown to have bony metastases on plain X-ray. In the remainder, where X-rays showed normal or benign appearance, MRI of the spine was offered. Twenty-four patients underwent MRI examination which showed vertebral metastases in 11 cases. Magnetic resonance imaging is shown to be a useful, noninvasive, complementary investigation for evaluation of patients known to have malignant disease and suspected of having vertebral metastases on bone scintigraphy.

Augmentation of parathyroid 201Tl/99Tcm scanning by infusion of trisodium edetate.

A significant number of patients with primary hyperparathyroidism have negative preoperative 201Tl/99Tcm subtraction localization scans. In this study an attempt was made to improve scan localization by creating a period of relative hypocalcaemia and increased parathyroid hormone (PTH) secretion before scanning. Six patients with primary hyperparathyroidism were studied (mean serum calcium 2.80 mmol l-1; range 2.70-2.95). All had had a negative standard 201Tl/99Tcm scan carried out within the 6 months prior to this study. Patients were commenced on an intravenous infusion of the calcium chelating agent trisodium edetate at a dose of 24 mg kg-1 h-1 given in 500 ml 0.9% saline over 90 min. Immediately thereafter a 201Tl/99Tcm scan was carried out in the usual way. Three patients showed areas of discordant thallium uptake consistent with the presence of a parathyroid adenoma. Two of these patients had surgery and an adenoma was found at the site corresponding to the scan appearances. It would appear that creating relative hypocalcaemia and increasing PTH secretion may allow increased thallium uptake, possibly secondary to the increased cellular metabolic activity, and thus creating a positive scan.

Gallbladder emptying following cholecystokinin and fatty meal in normal subjects.

A quantitative study of gallbladder emptying using 99mTc-HIDA as a bile tracer was performed with either CCK or a fatty meal as gallbladder stimulant. Its aims were to establish; (1) the reproducibility of CCK- and fatty-meal-induced gallbladder contraction, and (2) temporal patterns of gallbladder emptying following a physiological meal. Nineteen healthy, fasted volunteers were selected for 3-minute CCK administration (IV Boots Pancreozymin 2CHR units/kg) or a 40 g fatty meal. Each underwent repeat scans not less than 14 days after the first. Quantitative activity/time curves were drawn with computer analysis establishing gallbladder ejection fractions (GBEF) for each stimulus. Our results demonstrated: (1) poor reproducibility of CCK-induced gallbladder contraction precluding its diagnostic use, (2) improved but still variable meal-induced gallbladder contraction, and (3) evidence for a neurocephalic emptying response with a fatty meal stimulus.

The role of 99mTc HIDA cholescintigraphy in the diagnosis of acute gallbladder disease: comparison with oral cholecystography and ultrasonography.

Fifty-four patients with suspected acute cholecystitis underwent 99mTc HIDA cholescintigraphy, ultrasonography and oral cholecystography. The correct diagnosis was reached in 49 patients by cholescintigraphy (91%) in 35 (65%) by ultrasonography and in 45 (83%) by oral cholecystography. 99mTc HIDA cholescintigraphy provides a rapid accurate diagnosis with minimal discomfort to the patient and is the investigation of choice for patients with symptoms of acute gallbladder disease, particularly if early cholecystectomy is to be considered.

Ophthalmopathy in early thyrotoxicosis--relationship to thyroid receptor antibodies and effects of treatment.

A prospective study of 25 newly diagnosed thyrotoxic patients was undertaken to determine the incidence and severity of ophthalmopathy in the early stages of the disease. A quantitative analysis of the ocular muscle changes was made using B scan ultrasonography, and the effects of treatment for the thyroid disease on the course of the eye changes was assessed. Although the majority (75%) of patients showed only mild clinical signs of ophthalmopathy (Werner Class 3 or less), 92% had ultrasonographic evidence of ocular muscle enlargement. Clinical involvement of the extraocular muscles was seen in 12% of the cases. There was an inverse correlation between the serum level of thyroid stimulating hormone receptor antibody (TR Ab) and the size of the extraocular muscles. Recovery of the euthyroid state with treatment was accompanied by a decrease in orbital infiltration in some cases, both clinically (reduced amplitude of intraocular pressure rise on elevation of the globe) and by ultrasonography, but the improvement was not statistically significant.