Electrical conductivity of oxidized-graphenic nanoplatelets obtained from bamboo: effect of the oxygen content

The large-scale production of graphene and reduced-graphene oxide (rGO) requires low-cost and eco-friendly synthesis methods. We employed a new, simple, cost-effective pyrolytic method to synthetize oxidized-graphenic nanoplatelets (OGNP) using bamboo pyroligneous acid (BPA) as a source. Thorough analyses via high-resolution transmission electron microscopy and electron energy-loss spectroscopy provides a complete structural and chemical description at the local scale of these samples. In particular, we found that at the highest carbonization temperature the OGNP-BPA are mainly in a sp(2) bonding configuration (sp(2) fraction of 87%). To determine the electrical properties of single nanoplatelets, these were contacted by Pt nanowires deposited through focused-ion-beam-induced deposition techniques. Increased conductivity by two orders of magnitude is observed as oxygen content decreases from 17% to 5%, reaching a value of 2.3 × 10(3) S m(-1) at the lowest oxygen content. Temperature-dependent conductivity reveals a semiconductor transport behavior, described by the Mott three-dimensional variable range hopping mechanism. From the localization length, we estimate a band-gap value of 0.22(2) eV for an oxygen content of 5%. This investigation demonstrates the great potential of the OGNP-BPA for technological applications, given that their structural and electrical behavior is similar to the highly reduced rGO sheets obtained by more sophisticated conventional synthesis methods.

Floral isolation is the major reproductive barrier between a pair of rewarding orchid sister species

The crucial role of reproductive isolation in speciation has long been recognized; however, a limited number of studies quantify different isolation barriers and embed reproductive isolation in a phylogenetic context. In this study, we investigate reproductive isolation between the often sympatrically occurring orchid species, Gymnadenia conopsea and G. odoratissima. We examine the phylogenetic relationship between the two species and analyse floral isolation, fruit set and seed viability from interspecies crosses, as well as the ploidy level. Additionally, we quantify interspecies differences in floral signals and morphology. The results suggest that the two species have a sister-species relationship. In terms of reproductive isolation, we found complete floral isolation between the two species, but little to no post-pollination isolation; the species also mostly had the same ploidy level in the studied populations. We also show clear distinctions in floral signals, as well as in floral size and spur length. We propose that respective adaptation to short- vs. long-tongued pollinators was the driver of speciation in the here studied Gymnadenia species. Our study supports the key role of floral isolation in orchid speciation and shows that floral isolation is not restricted to highly specialized pollination systems, but can also occur between species with less specialized pollination.

Noninvasive genomic detection of melanoma

BACKGROUND

Early detection and treatment of melanoma is important for optimal clinical outcome, leading to biopsy of pigmented lesions deemed suspicious for the disease. The vast majority of such lesions are benign. Thus, a more objective and accurate means for detection of melanoma is needed to identify lesions for excision.

OBJECTIVES

To provide proof-of-principle that epidermal genetic information retrieval (EGIR™; DermTech International, La Jolla, CA, U.S.A.), a method that noninvasively samples cells from stratum corneum by means of adhesive tape stripping, can be used to discern melanomas from naevi.

METHODS

Skin overlying pigmented lesions clinically suspicious for melanoma was harvested using EGIR. RNA isolated from the tapes was amplified and gene expression profiled. All lesions were removed for histopathological evaluation.

RESULTS

Supervised analysis of the microarray data identified 312 genes differentially expressed between melanomas, naevi and normal skin specimens (P<0·001, false discovery rate q<0·05). Surprisingly, many of these genes are known to have a role in melanocyte development and physiology, melanoma, cancer, and cell growth control. Subsequent class prediction modelling of a training dataset, consisting of 37 melanomas and 37 naevi, discovered a 17-gene classifier that discriminates these skin lesions. Upon testing with an independent dataset, this classifier discerned in situ and invasive melanomas from naevi with 100% sensitivity and 88% specificity, with an area under the curve for the receiver operating characteristic of 0·955.

CONCLUSIONS

These results demonstrate that EGIR-harvested specimens can be used to detect melanoma accurately by means of a 17-gene genomic biomarker.

The Triad of Idiopathic Normal-Pressure Hydrocephalus: A Clinical Practice Case Report

An 89-year-old white male presented with memory impairment, slowness in responsiveness, and frequent falls over a two-year duration. Six months earlier, the patient was believed to have had a “dementia with parkinsonian features,” but showed no response to incrementing doses of both donepezil and carbidopa-levodopa. Urinary urgency was believed to have been due to prostate hypertrophy. A head CT with contrast revealed moderate ventriculomegaly in the setting of mild diffuse cortical atrophy. A diagnosis of idiopathic normal-pressure hydrocephalus (INPH) was made.

172 DOES ESTRADIOL-17β CAUSE CYCLE-DEPENDENT MODULATIONS OF UTERINE MILK PROTEIN IN BOVINE ENDOMETRIUM?

Uterine secretion from the endometrial glandular epithelium provides optimal conditions for early embryonic development. The uterine milk protein (UTMP), a member of the serine proteinase inhibitor superfamily, has been demonstrated to be a major progesterone-induced glycoprotein secreted by the endometrium during pregnancy. Previous transcriptomic analysis revealed that UTMP was highly abundant at estrus in the bovine endometrium (Bauersachs et al. 2005 J. Mol. Endocrinol. 34, 889–908). Here we describe a detailed characterization of UTMP mRNA expression at several time points during the bovine estrous cycle and the pre-implantation period. Simmental heifers were monitored with respect to serum progesterone (P4) and estradiol-17β (E2), and slaughtered at estrus or 3.5, 12, 15, or 18 days after estrus, or at Day 15 or 18 of pregnancy (n = 4 per group). The uterus was divided into corpus and caudal, middle and cranial parts of the ipsilateral uterine horn for sampling of intercaruncular endometrium. In addition, effects of steroid hormones were investigated by stimulating an endometrial cell culture obtained from Day 8 animals (n = 4) with physiological doses of P4 or E2. In all cases, UTMP mRNA was quantified by real-time RT-PCR. Pronounced changes of UTMP mRNA abundance were detected during the estrous cycle. Expression was highest at estrus, followed by a remarkable decrease at Day 3.5. There was no difference between pregnant and non-pregnant animals at Day 15. Cycling animals displaying a high P4 and low E2 content (P4 &gt; 2 ng mL-1 and E2 &lt; 1 pg mL-1) revealed a lower expression of UTMP at Day 18 compared to the pregnant heifers, whereas animals at Day 18 progressing toward estrus (P4 &lt; 1.5 ng mL-1 and E2 &gt; 3 pg mL-1) exceeded the mRNA expression of the pregnant group. Following stimulation with estradiol-17β, the in vitro UTMP transcripts increased significantly. These results indicate that two different interfering stimulatory events might take place. While estradiol-17β appeared to increase UTMP mRNA expression at estrus, a second factor, most probably embryo-derived or embryo-induced, is assumed to be responsible for the UTMP rise during early pregnancy. The distinct gradient from the cranial uterine horn to the corpus at estrus was less pronounced at Day 3.5 and absent at Days 12, 15, and 18, pointing toward functional implications regarding the passing gametes, particularly sperm. An antibody raised against bovine UTMP will further validate the observed mRNA regulations on the protein level. In conclusion, bovine UTMP seems to play a decisive role for precise cyclic regulation of the bovine uterine milieu and during early embryo-maternal communication. This work was supported by the DFG FOR 478.

Gene expression profiling of bovine endometrium during the oestrous cycle: detection of molecular pathways involved in functional changes

The endometrium plays a central role among the reproductive tissues in the context of early embryo-maternal communication and pregnancy. It undergoes typical changes during the sexual/oestrous cycle, which are regulated by the ovarian hormones progesterone and oestrogen. To identify the underlying molecular mechanisms we have performed the first holistic screen of transcriptome changes in bovine intercaruncular endometrium at two stages of the cycle--end of day 0 (late oestrus, low progesterone) and day 12 (dioestrus, high progesterone). A combination of subtracted cDNA libraries and cDNA array hybridisation revealed 133 genes showing at least a 2-fold change of their mRNA abundance, 65 with higher levels at oestrus and 68 at dioestrus. Interestingly, genes were identified which showed differential expression between different uterine sections as well. The most prominent example was the UTMP (uterine milk protein) mRNA, which was markedly upregulated in the cranial part of the ipsilateral uterine horn at oestrus. A Gene Ontology classification of the genes with known function characterised the oestrus time by elevated expression of genes, for example related to cell adhesion, cell motility and extracellular matrix and the dioestrus time by higher expression of mRNAs encoding for a variety of enzymes and transport proteins, in particular ion channels. Searching in pathway databases and literature data-mining revealed physiological processes and signalling cascades, e.g. the transforming growth factor-beta signalling pathway and retinoic acid signalling, which are potentially involved in the regulation of changes of the endometrium during the oestrous cycle.

Prevalence of neurotoxic Clostridium botulinum type C in the gastrointestinal tracts of tilapia (Oreochromis mossambicus) in the Salton Sea

Tilapia (Oreochromis mossambicus) have been implicated as the source of type C toxin in avian botulism outbreaks in pelicans (Pelecanus erythrorhynchos, Pelecanus occidentalis californicus) at the Salton Sea in southern California (USA). We collected sick, dead, and healthy fish from various sites throughout the Sea during the summers of 1999 through 2001 and tested them for the presence of Clostridium botulinum type C cells by polymerase chain reaction targeting the C(1) neurotoxin gene. Four of 96 (4%), 57 of 664 (9%), and five of 355 (1%) tilapia tested were positive for C. botulinum type C toxin gene in 1999, 2000, and 2001, respectively. The total number of positive fish was significantly greater in 2000 than in 2001 (P<0.0001). No difference in numbers of positives was detected between sick and dead fish compared with live fish. In 2000, no significant relationships were revealed among the variables studied, such as location and date of collection.

211 TEMPORAL AND SPATIAL EXPRESSION PROFILE OF THE UTERINE MILK PROTEIN — A MEMBER OF THE SERINE PROTEASE INHIBITOR SUPERFAMILY — IN THE BOVINE ENDOMETRIUM

A combination of subtracted cDNA libraries and cDNA array hybridization was applied to identify differentially expressed genes in the bovine intercaruncular endometrium at estrus and diestrus. Six cyclic Simmental heifers were cycle-synchronized and slaughtered the morning after standing heat occurred (n = 3) or 12 days after estrus (n = 3), respectively. The uterus was divided into seven sections: corpus, plus the caudal, middle, and cranial parts of both uterine horns. Samples were collected from the epithelial layer of the lamina propria of the intercaruncular endometrium. Two subtracted libraries were prepared and analyzed by array hybridization with probes produced from the 42 tissue samples. More than 130 differentially expressed genes were identified. Among these genes, the mRNA for the uterine milk protein (UTMP) showed a much higher expression level at estrus versus diestrus. Furthermore, the expression level differed markedly between the uterus sections. Statistical significance was tested using ANOVA and Student Newman Keuls post-hoc test (GeneSpring® version 6.1, Silicon Genetics, Redwood City, CA, USA). There was a pronounced expression gradient from both cranial uterine horns (highest) to the corpus (lowest) at estrus. UTMP mRNA level was highest in the ipsilateral cranial horn. A more accurate quantification was done by quantitative real-time RT-PCR using the same RNA samples as for array hybridization and, in addition, samples from further time points of the estrous cycle and early pregnancy. The results obtained by array hybridization were clearly confirmed. UTMPs, also known as uterine serpins (US), were previously shown to be the major products secreted by the uteri of cattle, sheep, and pigs during pregnancy. The US are glycoproteins belonging to the serpin (serine proteinase inhibitor) superfamily of proteins. However, no inhibitory activity to any serine proteinase has been found. The ovine uterine serpin (OvUS) has been shown to inhibit a wide variety of immune responses, including mixed lymphocyte reaction, T cell-dependent antibody production, and NK (natural killer)-like activity, indicating a major role in protecting the conceptus from maternal immune reactions. The four members of the US family form a clade distinct from other serpins, which have probably adopted important biological functions in the reproductive biology of Artiodactyla. Therefore, the identified expression gradient of the UTMP mRNA at estrus may be of particular importance, e.g. for sperm selection, and deserves further investigation at the protein level and in functional studies. This work was supported by the Deutsche Forschungsgemeinschaft (Research Unit “Mechanisms of Embryo-Maternal Communication”; FOR 478/1).

Presence of anti-Neoparamoeba sp. antibodies in Tasmanian cultured Atlantic salmon, Salmo salar L

Previous studies have indicated that when Atlantic salmon, Salmo salar L., are exposed to Neoparamoeba sp. the fish produce anti-Neoparamoeba sp. antibodies. It appears unlikely that these antibodies elicit any specific protection against amoebic gill disease (AGD) as fish with demonstrable activities have been affected by AGD. Experiments were conducted on Atlantic salmon cultured throughout Tasmania to assess the natural production of antibodies towards Neoparamoeba sp. Fish were sampled from areas where AGD was prevalent and from areas where there had been no reported cases. An enzyme-linked immunosorbent assay (ELISA) was used to measure anti-Neoparamoeba sp. antibody activities in serum. All fish from sea water had antibody activities greater than the negative control fish, including fish from areas with no reported cases of AGD. Time trial samples indicated that time after transfer to sea water did not appear to be a significant (P > 0.05) factor in antibody activity, however location was (P < 0.05). There was no agreement (corrected kappa value, 0.16) between the ELISA result and the isolation of Neoparamoeba sp. from the gills of the same fish. The results suggest that Atlantic salmon in seawater culture in Tasmania produce anti-Neoparamoeba sp. antibodies regardless of infection history, suggesting the presence of Neoparamoeba sp. in the environment.

Cadmium-induced changes in antioxidative systems, hydrogen peroxide content, and differentiation in Scots pine roots

To investigate whether Cd induces common plant defense pathways or unspecific necrosis, the temporal sequence of physiological reactions, including hydrogen peroxide (H(2)O(2)) production, changes in ascorbate-glutathione-related antioxidant systems, secondary metabolism (peroxidases, phenolics, and lignification), and developmental changes, was characterized in roots of hydroponically grown Scots pine (Pinus sylvestris) seedlings. Cd (50 microM, 6 h) initially increased superoxide dismutase, inhibited the systems involved in H(2)O(2) removal (glutathione/glutathione reductase, catalase [CAT], and ascorbate peroxidase [APX]), and caused H(2)O(2) accumulation. Elongation of the roots was completely inhibited within 12 h. After 24 h, glutathione reductase activities recovered to control levels; APX and CAT were stimulated by factors of 5.5 and 1.5. Cell death was increased. After 48 h, nonspecific peroxidases and lignification were increased, and APX and CAT activities were decreased. Histochemical analysis showed that soluble phenolics accumulated in the cytosol of Cd-treated roots but lignification was confined to newly formed protoxylem elements, which were found in the region of the root tip that normally constitutes the elongation zone. Roots exposed to 5 microM Cd showed less pronounced responses and only a small decrease in the elongation rate. These results suggest that in cells challenged by Cd at concentrations exceeding the detoxification capacity, H(2)O(2) accumulated because of an imbalance of redox systems. This, in turn, may have triggered the developmental program leading to xylogenesis. In conclusion, Cd did not cause necrotic injury in root tips but appeared to expedite differentiation, thus leading to accelerated aging.

Cadmium-induced changes in antioxidative systems, hydrogen peroxide content, and differentiation in Scots pine roots

To investigate whether Cd induces common plant defense pathways or unspecific necrosis, the temporal sequence of physiological reactions, including hydrogen peroxide (H(2)O(2)) production, changes in ascorbate-glutathione-related antioxidant systems, secondary metabolism (peroxidases, phenolics, and lignification), and developmental changes, was characterized in roots of hydroponically grown Scots pine (Pinus sylvestris) seedlings. Cd (50 microM, 6 h) initially increased superoxide dismutase, inhibited the systems involved in H(2)O(2) removal (glutathione/glutathione reductase, catalase [CAT], and ascorbate peroxidase [APX]), and caused H(2)O(2) accumulation. Elongation of the roots was completely inhibited within 12 h. After 24 h, glutathione reductase activities recovered to control levels; APX and CAT were stimulated by factors of 5.5 and 1.5. Cell death was increased. After 48 h, nonspecific peroxidases and lignification were increased, and APX and CAT activities were decreased. Histochemical analysis showed that soluble phenolics accumulated in the cytosol of Cd-treated roots but lignification was confined to newly formed protoxylem elements, which were found in the region of the root tip that normally constitutes the elongation zone. Roots exposed to 5 microM Cd showed less pronounced responses and only a small decrease in the elongation rate. These results suggest that in cells challenged by Cd at concentrations exceeding the detoxification capacity, H(2)O(2) accumulated because of an imbalance of redox systems. This, in turn, may have triggered the developmental program leading to xylogenesis. In conclusion, Cd did not cause necrotic injury in root tips but appeared to expedite differentiation, thus leading to accelerated aging.

Corticosteroids and cognition

The brain is a major target organ for corticosteroids. It has been observed that excessive circulatory levels of endogenous and exogenous corticosteroids are frequently associated with cognitive impairment in a wide variety of clinical disease states. Cognition and low levels of corticosteroids have been less well studied. In this paper we review the literature on glucocorticosteroid effects on cognition and delineate specific functions that appear to be causally affected. We draw a possible connection to specific areas of brain perturbation, including the hippocampus and frontal lobe regions. The possibility that cognitive dysfunction caused by glucocorticoids can be pharmacologically managed is introduced.

Assessing depression with the MMPI and MMPI-2

The usefulness of the MMPI (Hathaway & McKinley, 1951 ) and MMPI-2 (Butcher, Dahlstrom, Graham, Tellegen, & Kaemmer, 1989) for diagnosing and assessing symptomatic depression has been the subject of considerable debate for a number of years. In this article, we review the relative contributions of the MMPI and MMPI-2 clinical and content scales in predicting depression. Positive predictive power, negative predictive power, and overall classification rate were computed for Scale 2 (D) of the MMPI and MMPI-2 and the Depression content scale (DEP) of the MMPI-2. Scale 2 (D) of both the MMPI and MMPI-2 appears to be moderately accurate in predicting depression. Although some studies suggest that the content scale DEP provides incremental validity over Scale 2 (D) of the MMPI-2, the results of this review indicate that the content scale DEP of the MMPI-2 does not exceed the diagnostic efficiency of Scale 2 in predicting depression.

Role of interferon gamma in the pathogenesis of primary respiratory syncytial virus infection in BALB/c mice

Immunologic mechanisms are thought to contribute to the pathogenesis of respiratory syncytial virus (RSV) bronchiolitis in humans. RSV-infected BALB/c mice exhibit tachypnea and signs of outflow obstruction, similar to symptoms in humans. Interferon gamma (IFNgamma) has been found to be the predominant cytokine produced in humans and mice with RSV infection. We therefore undertook this study to evaluate the role of IFNgamma in the development of respiratory illness in RSV-infected mice. BALB/c mice were infected with RSV, and lung function was assessed by plethysmography. Bronchoalveolar lavage (BAL) fluids were analyzed for the concentration of interferon gamma (IFNgamma) and the presence of inflammatory cells, and lung tissue sections were examined for histopathologic changes. The role of IFNgamma was further addressed in studies of IFNgamma knock-out mice (IFNgamma(-/-)) and of mice depleted of IFNgamma by in vivo administration of a neutralizing antibody. After infection, mice developed respiratory symptoms that were strongly associated with the number of inflammatory cells in BAL, as well as with the concentrations of IFN-gamma. Both IFN-gamma(-/-) mice and mice treated with anti-IFNgamma developed more extensive inflammation of the airways than control mice. However mice lacking IFNgamma exhibited less severe signs of airway obstruction. Together these data suggest a protective role of IFNgamma in RSV infection in terms of limiting viral replication and inflammatory responses but also a pathogenic role in causing airway obstruction.

Stability and variability in competitive communities

Long-term variability in the abundance of populations depends on the sensitivity of species to environmental fluctuations and the amplification of environmental fluctuations by interactions among species. Although competitive interactions and species number may have diverse effects on variability measured at the individual species level, a combination of theoretical analyses shows that these factors have no effect on variability measured at the community level. Therefore, biodiversity may increase community stability by promoting diversity among species in their responses to environmental fluctuations, but increasing the number and strength of competitive interactions has little effect.

Axillary lymph node uptake of Tc-99m MIBI resulting from extravasation should not be misinterpreted as metastasis

Ipsilateral axillary lymph node visualization due to extravasation of Tc-99m MDP intravenous injection has been well documented. A patient with suspected angina underwent Tc-99m MIBI myocardial SPECT who had extravasation of Tc-99m MIBI in the antecubital region resulting in ipsilateral axillary lymph node uptake. This finding should not be misinterpreted as lymphatic nodal metastasis in a patient with breast cancer or lung cancer.

Myositis ossificans demonstrated by positive gallium-67 and technetium-99m-HMDP bone imaging but negative technetium-99m-MIBI imaging

Gallium-67-citrate and 99mTc-diphosphate bone imaging agents are localized in myositis ossificans, a tumor-like benign soft-tissue mass that makes it impossible to differentiate between malignant tumor and the infection/inflammatory process. We present such a myositis ossificans patient whose bone and 67Ga-citrate imagings showed increased uptake in the left thigh and two foci of the right gluteal region leading to inconclusive results. Technetium-99m-MIBI imaging showed the absence of substantial uptake in these regions. ACT scan confirmed myositis ossificans. The lack of 99mTc-MIBI uptake in myositis ossificans means that 99mTc-MIBI imaging may be useful in the differential diagnosis.

Reliability of taurine concentrations measured in single urine samples obtained from dogs eight hours after eating

OBJECTIVE

To evaluate the reliability of taurine concentrations measured in a single urine sample obtained from dogs 8 hours after eating, compared with taurine concentrations measured in 24-hour urine samples.

ANIMALS

18 healthy Beagles.

PROCEDURE

After emptying the urinary bladder by transurethral catheterization, dogs were fed a canned maintenance diet. Approximately 8 hours later, urine, plasma, and serum samples were obtained for determination of fractional urinary excretion of taurine and urine taurine-to-creatinine concentration ratios (Utaur:Ucr). Results were compared with 24-hour urinary taurine excretion rate.

RESULTS

Unbound and total fractional urinary taurine excretion correlated well with unbound and total 24-hour urinary taurine excretion. However, bound fractional urinary taurine excretion correlated poorly with bound 24-hour urinary taurine excretion. Unbound and total Utaur:Ucr correlated well with unbound and total 24-hour urinary taurine excretion. However, bound Utaur:Ucr correlated poorly with bound 24-hour urinary taurine excretion.

CONCLUSION AND CLINICAL RELEVANCE

Fractional urinary excretion of unbound and total taurine, and unbound and total Utaur:Ucr are reliable indicators of 24-hour urinary unbound and total taurine excretion in healthy dogs. However, determination of 24-hour urinary taurine excretion is recommended for evaluating urinary bound taurine concentrations of dogs.

Under control of the Ren-1c promoter, locally produced transforming growth factor-beta1 induces accumulation of glomerular extracellular matrix in transgenic mice

Our purpose was to elucidate the hypothesis that paracrine-produced transforming growth factor (TGF)-beta1 regulates the accumulation of extracellular matrix (ECM) in renal glomeruli, a hallmark of diabetic nephropathy. To produce TGF-beta1 from the juxtaglomerular apparatus in mouse kidneys, we cloned a mouse Ren-1c promoter fragment (-4.100 to +6 base pairs) upstream of porcine TGF-beta1 (pTGF-beta1) cDNA, mutated to ensure secretion of biologically active TGF-beta beta1. The resulting transgenic mice had significantly more TGF-beta1 in their kidneys than was in those of nontransgenic controls, as confirmed by immunohistochemistry, and the production of TGF-beta1 was enhanced in vivo by captopril-induced stimulation of the Ren-1c promoter. Overproduction of pTGF-beta1 close to the glomerulus resulted in a local accumulation of ECM, composed partly of collagen type IV and laminin, and thickening of the basement membrane, characteristic features of diabetic nephropathy. Interstitial accumulation of ECM and signs of tubular atrophy were present only in older mice (>5 months of age). Results from in situ hybridization and immunohistochemistry suggest that pTGF-beta1 stimulated the production of endogenous TGF-beta1 along collecting ducts and connecting tubules. The increased amount of biologically active TGF-beta1, transgenic as well as endogenous, was corroborated by heightened proteoglycan synthesis from incubated kidney slices. This transgenic model demonstrates that sustained local expression of TGF-beta1 leads to glomerulopathy. We conclude that autocrine- or paracrine-produced TGF-beta1 may play a role in the development of glomerular diseases, such as diabetic nephropathy.

Aneuploidogenic and clastogenic potential of the mycotoxins citrinin and patulin

The aneuploidogenic and clastogenic potentials of the mycotoxins citrinin (CIT) and patulin (PAT) were studied by determining inhibition of microtubule assembly under cell-free conditions and by measuring induction of mitotic arrest and micronuclei in cultured Chinese hamster V79 cells. Both CIT and PAT inhibited cell-free microtubule polymerization in a concentration-dependent manner. PAT, but not CIT, bound covalently to reactive thiol groups of microtubule proteins. At concentrations without gross cytotoxicity, mitotic arrest and CREST-positive micronuclei, i.e. micronuclei containing whole chromosomes/chromatids, were induced by CIT and PAT in V79 cells. The time course of micronucleus induction and positive CREST staining indicate the aneuploidogenic potential of CIT and PAT. CREST-negative micronuclei, i.e. micronuclei containing acentric chromosomal fragments, were induced by PAT but not by CIT, implying a clastogenic potential of PAT. The aneuploidogenic and clastogenic potential of PAT and the aneuploidogenic potential of CIT may well contribute to the putative carcinogenicity of these mycotoxins in long-term animal studies.

An unusual case of a tibial metastasis as the clinical presentation of bronchogenic adenocarcinoma

A patient with initial complaints of leg pain and difficulty walking was found to have a large right tibial metastatic tumor and poorly differentiated adenocarcinoma of the lung. Findings from total-body bone scintigraphy include a large area of increased uptake in the proximal half of the right tibia with a photon-deficient area medially, and focal areas of uptake in a right rib, in the femoral neck and the left ileum. An irregular area of increased uptake in the left lung mass was shown by thoracic bone SPECT. This is an unusual case of a tibial metastasis as the first clinical presentation of bronchogenic adenocarcinoma.

Information content and clarity of radiologists' reports for chest radiography

RATIONALE AND OBJECTIVES

We systematically characterized the information provided by chest radiography reports on a nationally representative sample of 822 elderly patients hospitalized in 297 acute-care hospitals in five states who had an admission diagnosis of congestive heart failure, acute myocardial infarction, or pneumonia.

METHODS

We studied the content of radiography reports, including mention of the type or adequacy of radiography; the presence or absence of a prior radiograph; comments about bones, the aorta, the mediastinum, and pleura and notation of the laterality of findings; and the presence of diagnosis. Two physicians reviewed each patient's report, and a third assigned the final rating when they disagreed.

RESULTS

Our analysis found wide variation in content of chest radiography reports, extensive variation in terms used to identify the presence or absence of abnormal findings, and a large degree of uncertainty in what was found.

CONCLUSION

With most hospitals introducing new information systems in response to technological advances and the need to generate more formal hospitalwide reports, the time is right to improve the quality of chest radiography reporting.

Reliability of carnitine concentrations measured in single postprandial urine samples from dogs

OBJECTIVE

To evaluate the reliability of urine carnitine concentrations measured in single postprandial samples, compared with carnitine concentrations measured in 24-hour urine samples.

ANIMALS

19 healthy Beagles.

PROCEDURE

After emptying the urinary bladder by catheterization, dogs were fed a canned canine maintenance diet. Approximately 8 hours later, urine, plasma, and serum samples were obtained for determination of urinary carnitine fractional excretion and urine carnitine-to-creatinine concentration ratio. Results were compared with 24-hour urinary carnitine excretion rate.

RESULTS

Fractional excretion of carnitine and urine carnitine-to-creatinine ratios correlated poorly with 24-hour urinary carnitine excretion.

CONCLUSION

Determination of 24-hour urinary carnitine excretion is recommended to measure urine carnitine concentrations in dogs.

A mural thrombus of an infrarenal aortic aneurysm demonstrated as photon deficiency in a radionuclide study

Radionuclide angiogram (RNA) and aortogram may underestimate external aneurysmal diameter. Photon deficient areas are not uncommon along the abdominal aortic aneurysm (AAA) on RNA. To determine whether or not photon deficient areas along the aneurysm could represent a large thrombus, we studied radionuclide aortic angiography in thirty-eight patients during a preoperative cardiac gated study. All the patients (men, ages from 60 to 78) had CT, US, and/or aortogram for comparison. The presence of a thrombus was determined by CT, US, and/or surgical findings. Twelve of 38 (32%) patients' RNA and blood pool images showed photon deficient areas along the aneurysmal walls having a large concentric or eccentric thrombus of the AAA. A large photon deficient area could be detected along the narrowing calibre of the aorta lumen. This finding results from a large mural thrombus being interposed between the left or right bowel/mesentery activity and the activity of the aneurysms functioning patent lumen. We concluded that a photon deficient area along an inferorenal aortic aneurysm may indicate a large thrombus of either eccentric or concentric type within an AAA.

Structural changes of thermally sprayed hydroxyapatite investigated by Rietveld analysis

Hydroxyapatite (HA) coatings were prepared by three thermal spraying methods: flame spraying, high velocity oxygen fuel spraying and plasma spraying. The HA was then examined by Rietveld analysis using the General Structure Analysis Software package (GSAS) and the results compared with those for the precursor powder. A comparison between HA before and after spraying showed that all three spraying methods caused a distortion in the unit cell in the form of a unit cell a-axis length decrease and a c-axis increase. Overall unit cell volumes showed a difference between the three thermal methods, with flame spraying and high velocity oxygen fuel methods giving a unit cell volume increase and the air plasma spraying method showing a decrease, compared to the starting powders. The two different starting powders used each showed a high oxygen occupancy for the hydroxyl oxygen. When thermally sprayed, both powders gave a reduction in occupancy, which suggested carbonate substitution for the OH group, but this was subsequently removed when thermally processed. The spraying also formed oxyapatite, indicated both by spectral analysis showing a reduction in the hydroxyl peak and by the hydroxyl oxygen occupancy falling to a level below 0.5. Major differences between the three spraying methods could be seen in the distortion index calculations. The thermal spraying techniques gave an increase in the distortion index, but it was significantly higher for the plasma-sprayed coating.