Protocol-driven multidetector SPECT/CT: integration of hybrid imaging into the routine workflow of whole-body bone scintigraphy in oncology patients.

AIM: To analyse the additional clinical value of protocol-driven and selective use of multidetector single-photon-emission tomography/computed tomography (SPECT/CT) in oncology patients undergoing whole-body bone scintigraphy (BS) and to analyse reporter confidence in diagnosis with and without SPECT/CT. MATERIALS AND METHODS: During a 2-year period, 2,954 whole-body BS examinations were performed in oncology patients, with 444 (15%) undergoing additional protocol-driven SPECT/CT. Retrospective evaluation of planar BS and SPECT/CT images was performed by two experienced dual-trained nuclear medicine radiologists. The BS and SPECT/CT images were graded blindly using a five-point scale designed to evaluate the likelihood of a lesion being benign or malignant. Interpretation was applied on a per-patient basis. RESULTS: There was a 74.5% increase in definitive diagnostic classification and a 26.6% reduction in equivocal findings with SPECT/CT when compared to BS alone (p<0001). Of cases initially classified as "probably benign" on BS, 5.1% (10/193) were reclassified to "probably malignant" (1%) or "malignant" (4.1%) using the SPECT/CT data. The highest impact in reporter confidence was seen with SPECT/CT in the interpretation of lesions within the pelvis (34%), ribs (23%), lumbar spine (22%), and thoracic spine (21%). CONCLUSION: Protocol-driven, selective use of SPECT/CT imaging to augment planar BS reduces equivocal findings and improves reporter confidence whilst minimising the impact on patient and reporting workflows.

Contact angle study of blood dilutions on common microchip materials.

Biocompatible polymers are commonly used to fabricate microfluidic channels for the study of biological flows such as blood microflows. The most common of these materials is polydimethylsiloxane (PDMS) which is very hydrophobic. Oxygenated plasma is advocated to treat the PDMS with reported decreases in contact angle i.e. increase the hydrophilicity of the material in order to make the liquid flow easily. All contact angle studies have been reported with water. Here the contact angles of blood suspensions, in saline and native plasma, are compared to each other and water on common microfluidic chip materials. The hydrophilic effect of plasma-treatment on PDMS is not found to be as significant with blood suspensions as it is with water. Red blood cells suspended in native plasma are found to have a greater contact angle than those suspended in saline.

Winter survival of larvae and pupae of the blowfly, Lucilia sericata (Diptera: Calliphoridae).

The mortality of larvae and pupae of the blowfly Lucilia sericata (Meigen) were examined during winter and spring, for two or three years. In soil cores in the field, 70-95% of the larvae died overwinter. Larvae congregated in the top 10 cm of the soil core and did not move extensively throughout the column during the winter. Larvae and pupae at greater depth were less likely to pupariate and emerge successfully than larvae closer to the surface. Under semi-natural conditions, where pupae were placed outside in sawdust filled tubes, in the absence of the usual biotic mortality factors, the mortality of larvae was considerably lower and was also unaffected by low winter temperatures. Hence, low temperatures did not appear to be the primary cause of high overwintering mortality in the field which, it is suggested, is more likely to be the result of the action of biotic mortality factors, such as entomopathogenic nematodes and fungi.

Pre-adult mortality in the blowfly Lucilia sericata.

Populations of the blowfly, Lucilia sericata (Meigen) (Diptera: Calliphoridae), have a considerable potential for rapid increase; the lifetime reproductive output of each adult female has been estimated to be between 130 and 172 eggs. Nevertheless, in the field, absolute population densities of this species are relatively low. To account for this difference, the levels of mortality affecting the eggs, feeding and wandering larvae and pupae of L. sericata were assessed in the field and laboratory. Percentage egg hatch was dependent on relative humidity with no egg eclosion at humidities below 50%; there was no significant effect of temperature on egg hatch. On infested sheep, the mean mortality of feeding larvae was 53%, but this ranged widely from 0% to 96%. There was no effect of atmospheric temperature or humidity on the mortality of feeding larvae in vivo. In the laboratory, only 10% of wandering larvae pupariated at 10 degrees C. At above 20 degrees C pupariation was consistently almost 100%. Percentage emergence increased from 0% at 10 degrees C to about 80% between 20 and 30 degrees C. The upper lethal temperature for pupae was approached at 35 degrees C. Analysis of the predation of pupae in the field revealed a weak, but significant curvilinear relationship between temperature and proportionate mortality and a median mortality of 0.49% per 24 h exposure (interquartile range = 5.2%). There was no evidence of density dependence in pupal predation. Overall, it is estimated that pre-adult mortality accounts for losses of approximately 97% of each generation, but this figure is subject to considerable variation depending on factors such as climate, time of year and host susceptibility.

Mammalian dynamin-like protein DLP1 tubulates membranes.

Dynamins are large GTPases with mechanochemical properties that are known to constrict and tubulate membranes. A recently identified mammalian dynamin-like protein (DLP1) is essential for the proper cellular distribution of mitochondria and the endoplasmic reticulum in cultured cells. In this study, we investigated the ability of DLP1 to remodel membranes similar to conventional dynamin. We found that the expression of a GTPase-defective mutant, DLP1-K38A, in cultured cells led to the formation of large cytoplasmic aggregates. Electron microscopy (EM) of cells expressing DLP1-K38A revealed that these aggregates were comprised of membrane tubules of a consistent diameter. High-magnification EM revealed the presence of many regular striations along individual membrane tubules, and immunogold labeling confirmed the association of DLP1 with these structures. Biochemical experiments with the use of recombinant DLP1 and labeled GTP demonstrated that DLP1-K38A binds but does not hydrolyze or release GTP. Furthermore, the affinity of DLP1-K38A for membrane is increased compared with wild-type DLP1. To test whether DLP1 could tubulate membrane in vitro, recombinant DLP1 was combined with synthetic liposomes and nucleotides. We found that DLP1 protein alone assembled into sedimentable macromolecular structures in the presence of guanosine-5'-O-(3-thio)triphosphate (GTPgammaS) but not GTP. EM of the GTPgammaS-treated DLP1 revealed clusters of stacked helical ring structures. When liposomes were included with DLP1, formation of long membrane tubules similar in size to those formed in vivo was observed. Addition of GTPgammaS greatly enhanced membrane tubule formation, suggesting the GTP-bound form of DLP1 deforms liposomes into tubules as the DLP1-K38A does in vivo. These results provide the first evidence that the dynamin family member, DLP1, is able to tubulate membranes both in living cells and in vitro. Furthermore, these findings also indicate that despite the limited homology to conventional dynamins (35%) these proteins remodel membranes in a similar manner.

Variations in feminine hygiene practices of military women in deployed and noncombat environments.

There is limited information on how military women manage feminine hygiene practices in combat and noncombat environments. The purpose of this study was to describe feminine hygiene practices of military women in deployed and noncombat (normal) environments. A nonexperimental descriptive research design was used. The study used a survey questionnaire, the Deployed Female Health Practice Questionnaire, which was developed specifically for military women to report their experiences with hygiene issues. Significant differences between deployed and normal environments were found in the areas of types of menses management products used and in douching and handwashing practices. Continuing education about safe feminine hygiene practices will help military women cope better in deployed (field) environments. Recommendations suggest further study on intervention strategies for hygiene management practices.

When criminals are shot: A survey of Washington, DC, jail detainees.

INTRODUCTION: Criminals are at high risk of being victims of violence, but little is known about their victimization. METHODS: A screen of Washington, DC, detainees found that 1 in 4 had been wounded in events that appear unrelated to their incarceration. Extensive interviews were conducted with 79 men entering the city jail from March through June 1997; the men reported 93 prior events in which they had been shot within the past 5 years. RESULTS: Eighty-three percent had personally witnessed someone being shot, and 46% had a family member killed with a gun. In the incidents in which they were shot, most were victims of robberies, assaults, and crossfires. The shootings were serious -- 35% were hit by more than 1 bullet, more than 90% went to the hospital, and 40% still had some disability from the wounds. These detainees report being shot by other criminals rather than by law-abiding citizens. Ninety percent would prefer to live in a world without easy access to firearms. CONCLUSION: These young men live in a violent world of gunplay. The overwhelming majority would prefer that firearms were not so readily available.

Medical response to bioterrorism: are we prepared?

The 1995 bombing of the Federal Building in Oklahoma City made terrorism a shocking reality for all Oklahomans. The fact that such an event could happen here, far from foreign political and ethnic conflicts and from large coastal cities, made us realize that no one is immune from the terrorist threat. But as horrific as that event and other terrorist incidents have been, the present threat of the use of infectious agents in acts of terrorism has the potential to cause far greater human death and suffering than any previously used terrorist weapon. Although health care professionals have not historically participated in terrorist planning and response activities, the addition of infectious agents to the terrorists' arsenal makes medical and public health professionals critical players in these efforts. Indeed, physicians have the ability to first recognize and report such an event and thereby diminish the impact. To meet the bioterrorism responsibility, physicians must be knowledgeable of this type of threat. In this article we present an overview of bioterrorism and review the organisms most likely to be used in a terrorist event.

Comparative efficacy and potency of long-term therapy with glipizide or glyburide in patients with type 2 diabetes mellitus.

BACKGROUND: Long-term studies on the comparative efficacy and relative potency of glipizide and glyburide are sparse and controversial. METHODS: In a randomized prospective trial, we compared the effectiveness and relative potency of glipizide and glyburide over a 15-month period in 18 patients with type 2 diabetes mellitus (DM2) (9 on glyburide and 9 on glipizide) who were unresponsive to diet therapy. Glycemic control was assessed using 4 methods: 1) quarterly fasting plasma glucose (FPG), and 2-hour postprandial plasma glucose after a standard breakfast; 2) insulin and glucose response to Sustacal (test meal) challenge every 3 to 6 months; 3) quarterly hemoglobin A1c; and 4) intravenous glucose tolerance testing every 6 months to measure first and second phase insulin secretion. Patient characteristics were similar in each treatment group. RESULTS: Similar doses of glipizide (11 mg/day) or glyburide (10 mg/day) resulted in comparable reduction of FPG and hemoglobin A1c and increase in first phase insulin response to intravenous glucose tolerance testing. There was greater reduction in FPG and 2-hour postprandial plasma glucose with glipizide than with glyburide in 6 months. Contrary to the Physicians' Desk Reference, but consistent with another short-term study, our long-term study demonstrated that glipizide and glyburide are equipotent at similar doses in controlling hyperglycemia in DM2. CONCLUSIONS: Glipizide and glyburide are effective in controlling hyperglycemia with similar doses in DM2. Glipizide exhibits greater reduction in FPG and 2PPG at 6 months. Additional studies are needed to validate equipotency of these drugs.

The dynamin family of mechanoenzymes: pinching in new places.

The large GTPase dynamin is a mechanoenzyme that mediates the liberation of nascent clathrin-coated pits from the plasma membrane during endocytosis. Recently, this enzyme has been demonstrated to comprise an extensive family of related proteins that have been implicated in a large variety of vesicle trafficking events during endocytosis, secretion and even maintenance of mitochondrial form. The potential contributions by the dynamin family to these diverse but related functions are discussed.

Medical care solicitation by criminals with gunshot wound injuries: a survey of Washington, DC, jail detainees.

BACKGROUND: The best estimates of nonfatal gunshot wounds in the United States come from hospital emergency room data and may miss, among other things, wounded individuals who do not seek medical treatment. Criminals may be those least likely to rely on professional care for their wounds. This study provides evidence of whether medical care is solicited by criminals after gunshot wounds. In addition, the circumstances of the injury events are described. METHODS: A case series of 79 detainees at a Washington, DC, jail who had previously been shot in 93 separate incidents were interviewed using a standardized questionnaire. Data were obtained concerning the age and race of the victim, the location of the wound, and the length of hospital stay. RESULTS: In 92% of the incidents, respondents reported going to the hospital; one-third of those shot were hospitalized for more than 1 week. More than half (54%) had been hit in the head or torso, and 40% had a current disability attributable to the wound. CONCLUSION: Among these "criminals," the vast majority reported that they obtained professional care for their gunshot wounds. Such evidence suggests that individuals previously thought unlikely to enter the medical care system after a firearm injury usually do so. Statistics on medically treated nonfatal gunshot wounds probably do not substantially underestimate the actual number of nonfatal shootings.

The dynamin-like protein DLP1 is essential for normal distribution and morphology of the endoplasmic reticulum and mitochondria in mammalian cells.

The dynamin family of large GTPases has been implicated in vesicle formation from both the plasma membrane and various intracellular membrane compartments. The dynamin-like protein DLP1, recently identified in mammalian tissues, has been shown to be more closely related to the yeast dynamin proteins Vps1p and Dnm1p (42%) than to the mammalian dynamins (37%). Furthermore, DLP1 has been shown to associate with punctate vesicles that are in intimate contact with microtubules and the endoplasmic reticulum (ER) in mammalian cells. To define the function of DLP1, we have transiently expressed both wild-type and two mutant DLP1 proteins, tagged with green fluorescent protein, in cultured mammalian cells. Point mutations in the GTP-binding domain of DLP1 (K38A and D231N) dramatically changed its intracellular distribution from punctate vesicular structures to either an aggregated or a diffuse pattern. Strikingly, cells expressing DLP1 mutants or microinjected with DLP1 antibodies showed a marked reduction in ER fluorescence and a significant aggregation and tubulation of mitochondria by immunofluorescence microscopy. Consistent with these observations, electron microscopy of DLP1 mutant cells revealed a striking and quantitative change in the distribution and morphology of mitochondria and the ER. These data support very recent studies by other authors implicating DLP1 in the maintenance of mitochondrial morphology in both yeast and mammalian cells. Furthermore, this study provides the first evidence that a dynamin family member participates in the maintenance and distribution of the ER. How DLP1 might participate in the biogenesis of two presumably distinct organelle systems is discussed.

Mood, cue and gender influences on motivation, craving and liking for alcohol in recreational drinkers.

The effects of exposure to an alcohol-related cue (drinking low-alcohol beer) and a musical depression/elation mood induction procedure, on craving, motivation and liking for alcohol, were studied in male and female recreational drinkers. Alcohol craving was assessed using the multidimensional desires for alcohol questionnaire (DAQ), motivation for alcohol was assessed by performance on a progressive ratio (PR) task reinforced with small volumes (25 ml) of low-alcohol beer, and liking for the reinforcers earned in the PR task was assessed using a visual analogue scale. Consumption of a half-pint of low-alcohol beer increased alcohol craving in male subjects but had no effect or decreased craving in female subjects. Subsequent induction of a depressed mood increased craving scores, relative to elated or neutral mood groups, but these effects were confined to abstinent (non-cued) subjects, both male and female. Performance on the PR task correlated significantly with one of the four factors of the DAQ, negative reinforcement, and was increased by induction of a depressed mood in abstinent female and cued male subjects. Reinforcer liking was unchanged following mood induction in male subjects, but decreased in both groups of female subjects. To summarize, the cue of drinking low-alcohol beer increased alcohol craving in men but not in women, and induction of a depressed mood increased alcohol craving and motivation, but also decreased alcohol liking. These effects were present to different extents in different cue/gender subgroups, and were partially independent.

Thrombin induced inhibition of neurite outgrowth from dorsal root ganglion neurons.

Thrombin is a multifunctional protease. Recent studies on cultured neuronal cells have suggested a function for thrombin in the development and maintenance of the nervous system. Thrombin has been found to induce neurite retraction and reverse stellation in neuroblastoma cell lines and rat astrocytes, respectively. The major focus of our study was to investigate the potential role of thrombin in peripheral nervous system development using the rat embryonic dorsal root ganglion model. We found a dose dependent inhibition of neurite outgrowth from explant dorsal root ganglion cultures upon exposure to 2 to 200 nM thrombin. This effect was reversed by the specific thrombin inhibitor, hirudin. A synthetic peptide that imitates the fully active receptor, thrombin receptor activating peptide, was also found to inhibit neurite outgrowth from dorsal root ganglia. bis-Benzimide stained neuronal cultures did not show any evidence of cell death after exposure to thrombin or thrombin receptor activating peptides. Immunohistochemical studies revealed specific staining of the thrombin receptor on neurons, with intense labeling along neurites. Enriched neuronal cultures exposed to thrombin and thrombin receptor activating peptides revealed rapid activation of phospholipase Cgamma-1, a second messenger associated with the thrombin receptor. These findings are the first to describe the localization of the thrombin receptor to dorsal root ganglion neurons. We propose that receptor activation is associated with thrombin induced inhibition of neurite outgrowth.

Bacterial oxidation of mercury metal vapor, Hg(0).

We used metalloregulated luciferase reporter fusions and spectroscopic quantification of soluble Hg(II) to determine that the hydroperoxidase-catalase, KatG, of Escherichia coli can oxidize monatomic elemental mercury vapor, Hg(0), to the water-soluble, ionic form, Hg(II). A strain with a mutation in katG and a strain overproducing KatG were used to demonstrate that the amount of Hg(II) formed is proportional to the catalase activity. Hg(0) oxidation was much decreased in stationary-phase cells of a strain lacking KatG, suggesting that the monofunctional hydroperoxidase KatE is less effective at this reaction. Unexpectedly, Hg(0) oxidation also occurred in a strain lacking both KatE and KatG, suggesting that activities other than hydroperoxidases may carry out this reaction. Two typical soil bacteria, Bacillus and Streptomyces, also oxidize Hg(0) to Hg(II). These observations establish for the first time that bacteria can contribute, as do mammals and plants, to the oxidative phase of the global Hg cycle.

A novel dynamin-like protein associates with cytoplasmic vesicles and tubules of the endoplasmic reticulum in mammalian cells.

Dynamins are 100-kilodalton guanosine triphosphatases that participate in the formation of nascent vesicles during endocytosis. Here, we have tested if novel dynamin-like proteins are expressed in mammalian cells to support vesicle trafficking processes at cytoplasmic sites distinct from the plasma membrane. Immunological and molecular biological methods were used to isolate a cDNA clone encoding an 80-kilodalton novel dynamin-like protein, DLP1, that shares up to 42% homology with other dynamin-related proteins. DLP1 is expressed in all tissues examined and contains two alternatively spliced regions that are differentially expressed in a tissue-specific manner. DLP1 is enriched in subcellular membrane fractions of cytoplasmic vesicles and endoplasmic reticulum. Morphological studies of DLP1 in cultured cells using either a specific antibody or an expressed green fluorescent protein (GFP)- DLP1 fusion protein revealed that DLP1 associates with punctate cytoplasmic vesicles that do not colocalize with conventional dynamin, clathrin, or endocytic ligands. Remarkably, DLP1-positive structures coalign with microtubules and, most strikingly, with endoplasmic reticulum tubules as verified by double labeling with antibodies to calnexin and Rab1 as well as by immunoelectron microscopy. These observations provide the first evidence that a novel dynamin-like protein is expressed in mammalian cells where it associates with a secretory, rather than endocytic membrane compartment.

A kinetic study of iron release from Azotobacter vinelandii bacterial ferritin.

The kinetics of iron release from Azotobacter vinelandii bacterial ferritin (AVBF) was measured by reduction of core iron with S2O4(2-) followed by chelation of Fe2+ with alpha, alpha-bipyridine (bipy). The rate was first order in AVBF and one half order in S2O4(2-), suggesting that SO2- is the active reductant formed by S2O4(2-) = 2SO2-. With zero-order conditions for dithionite and bipy, two consecutive first-order iron release reactions differing by a factor of about 14 were observed with rate constants of 0.0263 and 0.00184 sec-1, respectively, at 25 degrees C and pH 7.0. The faster reaction corresponded to the loss of 1433 iron atoms (91%) and the slower second reaction corresponded to loss of 145 (9%) of the original 1575 iron atoms present. The first reaction increased about twofold with pH variation between 6.5 and 8.0, whereas the second reaction was unchanged in the pH range 5.5-8. Both dramatically increased at pH 5.0. Methyl viologen increased the rate of both reactions about tenfold. The biphasic behavior for iron loss is interpreted as two different populations of iron atoms present in the core of AVBF, the first representing the bulk iron, and the second a group of unique iron atoms released last which may represent iron attached to the interior of the protein shell or iron associated with the heme groups. Kinetic stopped-flow measurements show that the heme is first reduced, followed by reduction of the core iron by reduced heme, suggesting an electron transfer role for heme in AVBF function.

Capital decisions. Where is the smart money being invested?

Health care executives are faced with a welter of priorities when it comes to allocating their increasingly scarce capital: they need to build information systems, organize primary care physicians, and expand outpatient services. But what are the defining issues? We asked five executives to explain how their strategies are changing as a result of managed care growth and integration. What emerges is a snapshot of the new capital allocation reality.