Microrheological characterisation of Cyanoflan in human blood plasma

Naturally occurring polysaccharidic biopolymers released by marine cyanobacteria are of great interest for numerous biomedical applications, such as wound healing and drug delivery. Such polymers generally exhibit high molecular weight and an entangled structure that impact the rheology of biological fluids. However, biocompatibility tests focus not so much on rheological properties as on immune response. In the present study, the rheological behaviour of native blood plasma as a function of the concentration of a cyanobacterium biopolymer is investigated via multiple particle tracking microrheology, which measures the Brownian motion of probes embedded in a sample, and cryogenic scanning electron microscope microstructural characterisation. We use Cyanoflan as the biopolymer of choice, and profit from our knowledge of its chemical structure and its exciting potential for biotechnological applications. A sol-gel transition is identified using time-concentration superposition and the power-law behaviour of the incipient network's viscoelastic response is observed in a variety of microrheological data. Our results point to rheology-based principles for blood compatibility tests by facilitating the assignment of quantitative values to specific properties, as opposed to more heuristic approaches.

Effects of a single paracetamol injection on the sevoflurane minimum alveolar concentration in dogs

This study aimed to determine the effect of a single injection of paracetamol on the sevoflurane minimum alveolar concentration (MAC) response to noxious mechanical stimulation. Seven healthy adult beagles were enrolled in a prospective, randomized, blinded, crossover experimental study. Anesthesia was induced with propofol [11.6 ± 2.4 mg/kg body weight (BW)] and maintained with sevoflurane. The MAC was determined before (MAC-1) and after (MAC-2) treatment with 15 mg/kg BW of intravenous (IV) paracetamol or saline over 15 minutes. Samples for plasma paracetamol determination were collected immediately after IV treatment administration and following MAC-2 determination (123 ± 27 minutes after starting paracetamol administration). The MAC-1 was similar between treatments (1.7% ± 0.4%). There were no differences between control and paracetamol groups at MAC-2 (2.0% ± 0.4% and 1.7% ± 0.5%, respectively; P = 0.285). Paracetamol plasma concentrations after paracetamol administration were 34.5 ± 9.9 μg/mL, decreasing at the end of the procedure (8.5 ± 4.2 μg/mL). In conclusion, 15 mg/kg BW of IV paracetamol did not significantly reduce sevoflurane MAC in healthy dogs.

Recurrence of vulvar carcinoma: A multidisciplinary approach

Although oncogynaecological management of bulky vulvar tumors tends to minimally-invasive approaches preceded by neoadjuvant therapies, ultra-radical surgery with curative intent may still have an important role. These procedures remain associated with significant short and long-term complications, imposing the need for novel reconstructive techniques [Brown et al., 2017, Di Donato et al., 2017, Moreno-Palacios et al., 2015, Oonk et al., 2017].

We present a video highlighting the crucial surgical steps of a successful pelvic exenterative procedure followed by perineal reconstruction with a muscle-sparing flap technique.

A 72-year woman with history of stage II vulvar epidermoid carcinoma, treated with radical surgery and adjuvant radiotherapy. At two-year follow-up local recurrence was diagnosed, handled with large excisional surgical treatment. Within four years a second local recurrence occurred, with infiltrative and bulky dimensions extending to perianal region and vaginal wall.

A multidisciplinary surgical approach with curative intent was performed, involving gynecologists, colorectal and plastic surgeons: radical bilateral vulvectomy with distal colpectomy, abdominoperineal resection with colostomy, perineal reconstruction with deep inferior epigastric perforators (DIEP) flap. No major intraoperative or postoperative complications occurred, and the patient was discharged within two weeks with no readmissions for wound care. At two-year follow up she remains in complete remission of the disease. No flap complications occurred during this period.

In highly selected patients with recurrent vulvar cancer previously submitted to multiple surgeries and radiotherapy, pelvic exenterative procedures followed by reconstructive techniques allow free surgical margins minimizing morbidity and pelvic disfiguring surgery. Association of reconstructive techniques to radical vulvo-vaginal surgery can shift the paradigm of oncological treatment approach, improving outcomes and quality-of-life.

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In selected cases of recurrent vulvar cancer, radical procedures still play a role.

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A multidisciplinary surgical approach is crucial for better outcomes.

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Novel reconstructive techniques improve patient satisfaction and quality-of-life.

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The DIEP flap is a complex but feasible option for large perineal defects.

Multiple-trait genomewide mapping and gene network analysis for scrotal circumference growth curves in Brahman cattle

Fertility traits are economically important in cattle breeding programs. Scrotal circumference (SC) measures are repeatable, easily obtained, highly heritable, and positively correlated with female fertility traits and sperm quality traits in males. A useful approach to summarize SC measures over time is using nonlinear models, which summarize specific measures of SC in a few parameters with biological interpretation. This approach facilitates the selection of bulls with larger SC and maturity index (K), that is, early maturing animals. Because SC is a sex-limited trait, identifying the underlying genomics of growth curve parameters will allow selection across both males and females. We reported the first multitrait genomewide association study (GWAS) of estimated growth curve parameters for SC data in Brahman cattle. Five widely used nonlinear models were tested to fit a total of 3,612 SC records, measured at 6, 12, 18, and 24 mo of age. The von Bertalanffy model, individually fitted for each animal, best fit this SC data. Parameter estimates SC at maturity (A) and K as well as SC at all ages were jointly analyzed in a GWAS to identify 1-Mb regions most strongly associated with each trait. Heritabilities were 0.25 for K and 0.32 for A and ranged from 0.51 to 0.72 for SC at 6 (SC6), 12 (SC12), 18 (SC18), and 24 mo of age (SC24). An overlapping window on chromosome 14 explaining around 0.8% of genetic variance for K, SC12, SC18, and SC24 was observed. The major positional candidate genes within 1 Mb upstream and downstream of this overlapping window were , , , and . Windows of 1 Mb explaining more than 0.4% of each trait on chromosomes 1, 3, 6, 7, 14, 17, 18, 24, 25, and 26 were identified. Pathways and net-work analyses were indicated through transcription factors playing a role on fertility traits: , , , , , , and . Further validation studies on larger populations or other breeds are required to validate these findings and to improve our understanding of the biology and complex genetic architecture of traits associated with scrotal growth and male fertility in cattle.

Paraneoplastic limbic encephalitis--neurologic paraneoplastic syndrome associated with ovarian malignancy--the importance of clinical recognition

Paraneoplastic limbic encephalitis (PLE) is a rare disorder and it is also under-reported due to the difficulty in establishing the diagnosis. The delay in treatment could potentially lead to devastating neurological outcomes. The authors report a 32-year-old Caucasian, nullipara woman, who presented with a subacute dementia associated to generalized tonic-clonic seizure with rapid progression to coma. The diagnosis of immature ovarian teratoma surgical Stage FIGO IA R0 with PLE was confirmed. The patient began earlier oral corticosterois and human intravenous immunoglobulin. She was discharged one month after surgery with no neurologic deficit and remains three years later in oncological remission. A diagnosis of PLE should be considered in the differential diagnosis of unexplained dementias. Early diagnosis, treatment of the underlying malignancy, and prompt intervention with immunotherapy in this patient at the onset of presentation facilitated regression of the neurological syndrome and explains the favorable neurological outcome.

P5-16-03: The Breast Cancer Novela, Se Valiente…Son Tus Senos, an Innovative Tool To Educate Latina Women about Breast Cancer

Background

The Hispanic population is the fastest growing population and largest minority group in the United States. Breast cancer remains the leading cause of cancer death among latina women in part because they are more frequently diagnosed at a later stage than non-Hispanic whites. Critical information about early detection, diagnosis and treatment options is often inaccessible due to cultural and language barriers. There is a need to reach the Hispanic community in new and compelling ways. The purpose of this initiative was to reach diverse Spanish speaking communities, particularly in New York City, with information about breast health and breast cancer that was culturally-sensitive, language appropriate, scientifically and medically accurate and, most importantly, relevant to the lives of the people in the community.

Methods: Latina breast cancer survivors and non-survivors from diverse Hispanic communities were identified and three 8 person focus groups, two for non-survivors and one for survivors, were organized to explore breast cancer-related issues relevant to these communities. The women's personal stories and common issues and experiences as well as medical information reviewed by a medical advisory group, formed the basis for the development of a breast cancer novela. The novela is a popular Spanish-language comic book style publication widely distributed in the Hispanic communities. The breast cancer novela used the real life stories of the women to address barriers to accessing health care and empower women in Hispanic communities. A distribution plan was developed and a curriculum created for inperson educational seminars at community organizations. Surveys prior to and following the educational intervention were conducted.

Results: We distributed over 25,000 novelas in Spanish to 478 sites within New York City and to 89 other sites throughout the U.S. We printed and distributed 2500 copies of an English version of the novela at the request of health providers. Attendees at a launch event helped identify distribution sites and educational seminar venues. Peer facilitators conducted these seminars, with the novela as the primary communication tool. The content of the workshops included information about breast health, risk, early detection, myths and realities about a diagnosis, managing relationships, survivorship and resources. To date, 17 seminars have been conducted and attended by more than 330 attendees. Results of the surveys as well as detailed information describing the distribution sites of the novela and feedback we received about its impact, will be presented at SABCS

Discussion: Se Valiente… Son Tus Senos, is an innovative educational tool that conveys information about breast health, breast cancer detection, diagnosis, treatment and survivorship that is personal, relevant, compelling and accessible. The breast cancer novela serves as a vehicle to change information levels and increase women's knowledge and to provide health providers with insights that enable them to treat members of Spanish-speaking communities in a culturally competent manner.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P5-16-03.

[Malassezia folliculitis in an immunocompromised patient]

Malassezia folliculitis (synonym: Pityrosporum folliculitis) is a polymorphic dermatomycosis characterized by the development of small papules and pustules. In severe cases, molluscoid comedonal papules are typical. The disease occurs mainly in sebum-rich areas of the face, back and chest, frequently affecting patients under immunosuppressive therapy. We report a case of Malassezia folliculitis observed in a heart transplant recipient who was successfully treated with itraconazole. Moreover, we summarize the taxonomy of the genus Malassezia as well as diagnostic and therapeutic measures of the related folliculitis.

Aprotinin and classic wound drainage are unnecessary in total hip replacement - a prospective randomized trial

BACKGROUND

Classic wound drainage is still common in hip replacement but its benefit is doubtful. The role of systemic administration of proteinase inhibitors like aprotinin to avoid perioperative blood loss is still unclear.

PATIENTS AND METHODS

In a prospective randomized trial, the perioperative blood loss in alloplastic hip replacement under the influence of proteinase inhibitor (aprotinin, Trasylol®) using wound drainage as well as compression treatment alone were compared. 80 patients were prospectively randomized in 4 arms. Patients received either aprotinin or placebo during surgery as well as drainage or targeted external wound compression.

RESULTS

Observing the "drug therapy" aprotinin had no effect on the intra- or postoperative blood loss (p>0.05), a trend to lower postoperative hemoglobin decline was found, but without significance. Thrombosis occurred in neither the aprotinin nor in the placebo group. Two patients had a severe allergic drug reaction and were excluded from the study. Under "non drug therapy" with compression therapy and wound drainage a significant difference in blood loss was found (p<0.001). The blood loss was higher under the wound drainage. There was no influence on the infection rate. Yet we could observe increased bruising under the sole external compression treatment.

CONCLUSION

The administration of aprotinin did not achieve the desired reduction of perioperative blood loss. Hence, costs and two severe allergic drug reactions in our study represent arguments against its use in regular treatment. Furthermore, it seems that wound drainage is neglectable in hip replacement and can be substituted by a sole compression treatment.

Evaluation of the tissue toxicity of antiseptics by the hen's egg test on the chorioallantoic membrane (HETCAM)

Background

Antiseptics are frequently used for the prophylaxis and treatment of local infections of chronic wounds. Whereas local antiseptics in general have a positive effect on wound healing an uncritical use may impair wound healing due to toxic side effects.

Objective

We sought to assess the vascular irritation potential of different antiseptic solutions and ointments commonly used for short and long term application as a measure of tissue toxicity.

Method

The vascular irritation was evaluated by the hen's egg test (HET) on the chorioallantoic membrane (CAM). The effects on the vessels of a mucous membrane were directly assessed by stereomicroscopic observation in vivo.

Results

Severe CAM irritation was observed after short-term applications of 1% octenidin-2HCl (Octeni sept™), 72% isopropanol (Cutasept™), 0.35% chloroxylenol (Dettol™) and 10% PVP-I ointment (Betaisodona™). Medium irritations were observed for 10% PVP-I solution (Betaisodona™), 3% lysosomal PVP-I ointment (Repithel™), 1.8% cadexomer-iodine ointment (Iodosorb™) and 1% cadexomer-iodine pellets (Iodosorb™). Finally, slight irritations were observed for 1% PVP-I solution (Betaisodona™), 0.1% polyhexanid plus betain (Prontosan™) and 1% silver-sulfadiazine ointment (Flammazine™), whereas 0.04% polyhexanid solution (Lavanid™), washings from sterile maggots of Lucilia sericata and filtrated enzymes from Clostridium histolyticum (Iruxol-N™) showed no effects of irritation. In the long-term approaches, no vascular irritations were found for polyhexanid, washings from Lucilia sericata and enzyme filtrations from Clostridium histolyticum.

Conclusion

The vascular injuries caused by the studied antiseptics are an indirect indicator of their tissue toxicity. Strikingly, even therapeutic substances, which have been regarded as safe in their application for the treatment of chronic wounds in clinical studies, showed severe irritations on the CAM. We suggest that agents with no or low irritation potential on the CAM should be preferred in the clinical practice in order to obtain optimal results.

Retinoid X receptor alpha controls innate inflammatory responses through the up-regulation of chemokine expression

The retinoid X receptor alpha (RXRalpha) plays a central role in the regulation of many intracellular receptor signaling pathways and can mediate ligand-dependent transcription by forming homodimers or heterodimers with other nuclear receptors. Although several members of the nuclear hormone receptor superfamily have emerged as important regulators of macrophage gene expression, the existence in vivo of an RXR signaling pathway in macrophages has not been established. Here, we provide evidence that RXRalpha regulates the transcription of the chemokines Ccl6 and Ccl9 in macrophages independently of heterodimeric partners. Mice lacking RXRalpha in myeloid cells exhibit reduced levels of CCL6 and CCL9, impaired recruitment of leukocytes to sites of inflammation, and lower susceptibility to sepsis. These studies demonstrate that macrophage RXRalpha plays key roles in the regulation of innate immunity and represents a potential target for immunotherapy of sepsis.

Gene expression of circulating tumour cells in breast cancer patients

Background

The diagnostic tools to predict the prognosis in patients suffering from breast cancer (BC) need further improvements. New technological achievements like the gene profiling of circulating tumour cells (CTC) could help identify new prognostic markers in the clinical setting. Furthermore, gene expression patterns of CTC might provide important informations on the mechanisms of tumour cell metastasation.

Materials and methods

We performed realtime-PCR and multiplex-PCR analyses following immunomagnetic separation of CTC. Peripheral blood (PB) samples of 63 patients with breast cancer of various stages were analyzed and compared to a control group of 14 healthy individuals. After reverse-transcription, we performed multiplex PCR using primers for the genes ga733.3, muc-1 and c-erbB2. Mammaglobin1, spdef and c-erbB2 were analyzed applying realtime-PCR.

Results

ga733.2 overexpression was found in 12.7% of breast cancer cases, muc-1 in 15.9%, mgb1 in 9.1% and spdef in 12.1%. In this study, c-erbB2 did not show any significant correlation to BC, possibly due to a highly ambient expression. Besides single gene analyses, gene profiles were additionally evaluated. Highly significant correlations to BC were found in single gene analyses of ga733.2 and muc-1 and in gene profile analyses of ga733.3*muc-1 and GA7 ga733.3*muc-1*mgb1*spdef.

Conclusion

Our study reveals that the single genes ga733.3, muc-1 and the gene profiles ga733.3*muc-1 and ga733.3*3muc-1*mgb1*spdef can serve as markers for the detection of CTC in BC. The multigene analyses found highly positive levels in BC patients. Our study indicates that not single gene analyses but subtle patterns of multiple genes lead to rising accuracy and low loss of specificity in detection of breast cancer cases.

Dexamethasone induces a heat-stress response that ameliorates the conformational consequences on antithrombin of L-asparaginase treatment

BACKGROUND

L-asparaginase (L-ASP) treatment of patients with acute lymphoblastic leukemia causes a severe antithrombin deficiency by intracellular retention of this serpin within the endoplasmic reticulum (ER) of hepatic cells, and a subsequent risk of thrombosis. Interestingly, co-administration of dexamethasone with L-ASP seems to reduce the risk of thrombosis.

OBJECTIVES

We have investigated the effect of two corticoids, dexamethasone and prednisone, on the conformational consequences of L-ASP treatment on antithrombin.

PATIENTS/METHODS

Levels, activity, conformation and immunohistological features of antithrombin were studied in patients, cell and mice models. Because of the importance of the steroid receptor-heat stress response (HSR) axis, and the role of unfolded protein response (UPR) in conformational diseases, we also evaluated Hsp27, Hsp70, Hsp90, HSF-1 and ER chaperons (Grp78 and Grp94).

RESULTS

In all models, L-ASP alone or in combination with prednisone caused the intracellular retention of antithrombin associated with a severe deficiency. In contrast, the combination of L-ASP with dexamethasone ameliorated both the deficiency and intracellular retention of the serpin, which is associated with increased expression of heat shock proteins and ER-chaperons.

CONCLUSIONS

These results suggest a protective effect of dexamethasone on the conformational consequences of L-ASP on antithrombin as a result of exacerbated HSR and UPR that help to explain the reduced risk of thrombosis reported in patients that follow this scheme of treatment.

CD6 binds to pathogen-associated molecular patterns and protects from LPS-induced septic shock

CD6 is a lymphocyte receptor that belongs to the scavenger receptor cysteine-rich superfamily. Because some members of the scavenger receptor cysteine-rich superfamily act as pattern recognition receptors for microbial components, we studied whether CD6 shares this function. We produced a recombinant form of the ectodomain of CD6 (rsCD6), which was indistinguishable (in apparent molecular mass, antibody reactivity, and cell binding properties) from a circulating form of CD6 affinity-purified from human serum. rsCD6 bound to and aggregated several Gram-positive and -negative bacterial strains through the recognition of lipoteichoic acid and LPS, respectively. The Kd of the LPS-rsCD6 interaction was 2.69 +/- 0.32 x 10(-8) M, which is similar to that reported for the LPS-CD14 interaction. Further experiments showed that membrane CD6 also retains the LPS-binding ability, and it results in activation of the MAPK signaling cascade. In vivo experiments demonstrated that i.p. administration of rsCD6 before lethal LPS challenge significantly improved mice survival, and this was concomitant with reduced serum levels of the proinflammatory cytokines TNF-alpha, IL6, and IL-1beta. In conclusion, our results illustrate the unprecedented bacterial binding properties of rsCD6 and support its therapeutic potential for the intervention of septic shock syndrome or other inflammatory diseases of infectious origin.

Therapeutic treatment with poly(ADP-ribose) polymerase inhibitors attenuates the severity of acute pancreatitis and associated liver and lung injury

BACKGROUND AND PURPOSE

The mortality associated with acute pancreatitis (AP) is largely attributable to abnormalities that occur in distant organs and supportive care remains the only treatment for patients with these complications. Recently, prophylactic pharmacological blockade of poly(ADP-ribose) polymerase (PARP) enzymes has been shown to attenuate the severity of the disease. However, the clinical relevance of PARP inhibitors administered after the onset of AP remains uncertain. The aim of the present study was to investigate the therapeutic effects of PARP inhibitors in established AP.

EXPERIMENTAL APPROACH

Mice were fed a choline/methionine-deficient/ethionine-supplemented (CMDE) diet to induce AP. PARP inhibitors were given at 36 h after the onset of CMDE diet. Severity of pancreatitis was assessed by measurements of serum amylase, lipase, IL-1beta and IL-6, and histological grading. Serum hepatic enzymes, myeloperoxidase (MPO) activity and morphological changes were measured as indicators of hepatic insult. Lung injury was evaluated by MPO activity and morphological changes. Survival rates of mice were monitored for 7 days.

KEY RESULTS

CMDE diet administration resulted in a significant increase in serum amylase, lipase, IL-1beta, IL-6, alanine aminotransferase and aspartate aminotranferase levels, indicating AP and associated liver injury. Analysis of the histopathological changes in pancreas, liver and lung revealed extensive tissue damage. Treatment of mice with PARP-inhibitors after the onset of AP was associated with a reduction in the severity of AP and, accordingly, with a reduced mortality rate.

CONCLUSIONS AND IMPLICATIONS

Our results support the therapeutic application of PARP inhibitors in the treatment of established AP.

In vivo effects of hyperthermia on the functional and conformational characteristics of antithrombin

BACKGROUND

High temperatures produce in vitro transitions of antithrombin to its inactive latent and polymeric forms. Accordingly, high body temperatures might contribute in vivo to conformational changes in antithrombin associated with increased thrombotic risk.

METHODS

We assessed the in vivo effects of different hyperthermic stimuli on antithrombin. We studied two mouse models of hyperthermia. (i) Febrile syndrome induced by turpentine. (ii) Heat stroke generated by exposure to 42 degrees C. Body temperatures were measured. Antigen, anti-factor Xa activity and conformational features of plasma antithrombin were studied. Furthermore, structural and ultrastructural features from livers were analyzed. Intracellular retention of serpins (antithrombin and alpha1-antitrypsin) was studied by western-blotting, immunohistochemistry, and immunogold-labeling-electron microscopy.

RESULTS

Hyperthermic stimuli caused a moderate deficiency of circulating antithrombin and a slight increase in its latent form. Moreover, hyperthermia caused intracellular retention of antithrombin into aggregates within the lumen of the endoplasmic reticulum of hepatocytes. This effect was similar for alpha1-antitrypsin.

CONCLUSION

Hyperthermia causes minor conformational changes on circulating antithrombin in vivo, although it has severe consequences for intracellular antithrombin and other hepatic serpins, inducing the intracellular retention of the nascent protein. These effects may contribute to the moderate plasma deficiency of antithrombin and the increased thrombotic risk detected in hyperthermic conditions.

[Frequent and rare dermatological diseases in HIV patients]

HIV patients develop a variety of infectious and non-infectious diseases of the skin and mucous membranes. Some of these serve as indicator diseases for a weakening immune system. While none of the dermatological complications is pathognomonic, conditions such as oral hairy leukoplakia, herpes zoster, thrush, and eosinophilic folliculitis should make physicians consider the possibility of underlying HIV disease. Moreover, one has to consider HIV if these skin diseases take an atypical or severe course, or if they do not respond properly to appropriate medication. Frequent and rare dermatoses occurring in HIV infection are discussed.

PARP-2 deficiency affects the survival of CD4+CD8+ double-positive thymocytes

Poly-(ADP-ribose) polymerase-2 (PARP-2) belongs to a large family of enzymes that synthesize and transfer ADP-ribose polymers to acceptor proteins, modifying their functional properties. PARP-2-deficient (Parp-2-/-) cells, similar to Parp-1-/- cells, are sensitive to both ionizing radiation and alkylating agents. Here we show that inactivation of mouse Parp-2, but not Parp-1, produced a two-fold reduction in CD4+CD8+ double-positive (DP) thymocytes associated with decreased DP cell survival. Microarray analyses revealed increased expression of the proapoptotic Bcl-2 family member Noxa in Parp-2-/- DP thymocytes compared to littermate controls. In addition, DP thymocytes from Parp-2-/- have a reduced expression of T-cell receptor (TCR)alpha and a skewed repertoire of TCRalpha toward the 5' Jalpha segments. Our results show that in the absence of PARP-2, the survival of DP thymocytes undergoing TCRalpha recombination is compromised despite normal amounts of Bcl-xL. These data suggest a novel role for PARP-2 as an important mediator of T-cell survival during thymopoiesis by preventing the activation of DNA damage-dependent apoptotic response during the multiple rounds of TCRalpha rearrangements preceding a positively selected TCR.

Silicon adsorption in defective carbon nanotubes: a first principles study

The electronic and structural properties of an (8, 0) single-walled carbon nanotube (SWNT) with a single vacancy and interacting with a Si atom are studied using first principles calculations based on the density-functional theory. Initially, the Si atom is positioned in the site above the vacancy, with its position fixed until the nanotube geometry is fully relaxed. After that, the Si atom approaches the tube and it is shown that one C atom is displaced outwards forming a bump. The final configuration, as well as each step of the process, is studied in detail and the resulting band structures and the total charge densities are systematically analysed.

Doppler ultrasonographic and scintigraphic assessment of an auxiliary heterotopic liver transplantation with portal vein arterialization in pigs

OBJECTIVE

Our aim was to evaluate liver graft integrity and function using scintigraphy and ultrasonography in a porcine model of auxiliary heterotopic liver transplantation with portal vein arterialization (AHLT-PVA).

MATERIALS AND METHODS

Using Doppler ultrasonography we evaluated eight AHLT-PVA by parenchymal echogenicity, portal and arterial anatomy, and portal and biliary system flow. Two types of scintigraphy were performed: microaggregated human albumin colloid scintigraphy and diisopropyl iminodiacetic acid (DISIDA) scintigraphy, both labeled with 99mTc.

RESULTS

The animals were distributed into two groups. The first group consisted of three animals with clinical suspicion of graft dysfunction, in which the ultrasonographic study revealed areas of parenchymal destructuring. In the scintigraphic study, heterogenous uptake was observed; there was no uptake in one animal. Necropsy of these three animals revealed areas of graft necrosis. The second group consisted of five animals with good clinical evolutions, in which the ultrasonographic study showed portal dilation, portal flow with arterial spiculations, and homogenous echogenicity of the hepatic parenchyma. The scintigraphic study revealed homogenous uptake by the graft and an elimination speed of the hepatobiliary agent similar to that of the native liver.

CONCLUSIONS

An heterogenous echostructure of the graft provided a sign of poor prognosis indicating necrosis in the same way as heterogenous uptake or nonuptake of radioisotope upon scintigraphy. Scintigraphy is a good method to evaluate biliary function and bile elimination. In an AHLT-PVA, the main ultrasound findings derived from arterialization were dilation of the portal system and portal flow with arterial spiculations.

Titanium monomers and wires adsorbed on carbon nanotubes: a first principles study

In this work a theoretical study of Ti monomers and wires interacting with an (8, 0) semiconductor single-wall carbon nanotube (SWNT), by inside as well as outside faces, is presented. Spin-polarized total-energy ab initio calculations, based on the density functional theory, are used to describe the structural, electronic and magnetic properties of the studied systems. The most stable configurations for monomers are found to be over the centre of a C-C bond for inside and over the midpoint of the centre of the hexagonal site for outside. Considering that the Ti atoms on the tube surface tend to form continuous wires, to allow a comprehensive view of the interaction of the Ti wires with the SWNT surface, we present a complete understanding, both from inside and outside the nanotube. Our calculations have shown that the most stable configuration is with the wire inside the tube, with the resulting electronic structures showing a metallic system with high hybridization between the Ti and C atoms and a large charge transfer from Ti to C atoms. For Ti wire adsorbed inside the tube the low spin configuration is shown to be more stable than high spin configuration and the opposite behaviour is observed for the corresponding outside case. These novel results are relevant for the understanding of Ti atoms covering and filling SWNTs, demonstrating the high stability of these systems and suggesting that they can be useful for future use in nanodevices, in particular for spintronics and nanosensors.

VUV spectroscopy of water under cellular conditions

The understanding of radiation damage within cells, and thence mutagenesis, depends upon a detailed knowledge of the spectroscopy and dissociation dynamics of water. Results of a new study of the electronic state spectroscopy of water, using synchrotron radiation are reported. In order to gain some insight into how the spectroscopy and dissociation dynamics of water is influenced by its environment we also report photo-absorption spectra of water within thin films of poly(o-methoxyaniline) which have been suggested as a good mimic for biological membranes in the cellular environment. Comparison of these spectra with those of gaseous water and condensed amorphous water ice suggest that water in such films is similar to gaseous water and does not show the blue shift suggested in some cellular models. The lowest energy of OH production from dissociation of water in the cellular environment may therefore be around 6.7 eV (185 nm).

The influence of the tip structure and the electric field on BN nanocones

Different configurations for BN nanocones with 240° disclination are analysed through first-principles calculations based on the density-functional theory. The studied cone tips involve either four pentagons with two homonuclear bonds or two squares and two hexagons with no homonuclear bonds. The structures are both terminated by two three-coordinated atoms. Cohesive energy results show that the cone terminated in pentagons is slightly energetically preferred. The influence of a 1.7 V Å(-1) external electric field, applied along the axis, on the structural changes and charge distributions is analysed. The responses of the charge distributions to the external electric field demonstrate the main role played by the B atoms for the applications of BN cones as probes in electronic microscopy as well as field emitters.

Vacancy formation process in carbon nanotubes: first-principles approach

The electronic and structural properties of a single-walled carbon nanotube (SWNT) under mechanical deformation are studied using first-principles calculations based on the density functional theory. A force is applied over one particular C-atom with enough strength to break the chemical bonds between the atom and its nearest neighbors, leading to a final configuration represented by one tube with a vacancy and an isolated C-atom inside the tube. Our investigation demonstrates that there is a tendency that the first bond to break is the one most parallel possible to the tube axis and, after, the remaining two other bonds are broken. The analysis of the electronic charge densities, just before and after the bonds breaking, helps to elucidate how the vacancy is formed on an atom-by-atom basis. In particular, for tubes with a diameter around 11 angstroms, it is shown that the chemical bonds start to break only when the externally applied force is of the order of 14 nN and it is independent of the chirality. The formation energies for the vacancies created using this process are almost independent of the chirality, otherwise the bonds broken and the reconstruction are dependent.

[Human papillomavirus associated with uterine cervix lesions]

It was studied the prevalence of human papillomavirus (HPV) among 228 women with lesions of uterine cervix attending the Ofir Loiola Institute, in Belem, Para, from March 1992 to May 1996. Histopathological examination was performed with all cervical biopsy samples obtained from these patients. In addition, specimens were analysed by both polimerase chain reaction and dot-blot hybridization to detect HPV DNA. The patients were assigned to three groups, according to the diagnosis made by histopathology, as follows: A, including 155 women suffering from invasive epidermoid carcinoma or adenocarcinoma; B, 54 patients having either cervical intraepithelial neoplasia grade II or III; and C, involving 19 women with chronic cervicitis. The prevalence rates of HPV in groups A, B and C were 70.3%, 63% and 36.8% respectively. HPV 16 accounted for 60.4% and 54.5% of types identified in groups A and B, respectively. Altogether HPV types 16, 18 and 33 were detected in 71.4% of positive patients belonging to group C.

[Immunoproliferative disease of the small intestine. Report of a case]

We report one case of immunoproliferative small intestinal disease with two rare characteristics. Firstly, the detection of monoclonal IgA-Kappa in serum and in the intestinal infiltrate and secondly, the advanced age of the patient at diagnosis. We checked up on Spanish literature and found an important number of patients that were diagnosed at such an age. We suggest that this disease may appear in elderly people in developed countries.