Laparoscopic versus open liver resection for hepatocellular carcinoma in patients with histologically proven cirrhosis: short- and middle-term results

BACKGROUND

Liver surgery, especially for cirrhotic patients, is one of the last areas of resistance to progress in laparoscopic surgery. This study compares the postoperative results and the 2-year patient outcomes between laparoscopic and open resection for hepatocellular carcinoma in patients with histologically proven cirrhosis.

METHODS

From May 2000 to October 2004, 23 consecutive cirrhotic patients who underwent laparoscopic hepatectomy (LH) for HCC were compared in a retrospective analysis with a historic group of 23 patients who underwent open hepatectomy (OH). The two groups were well matched for age, gender, American Society of Anesthesiology (ASA) class, tumor location and size, type of liver resection, and severity of cirrhosis. The selection criteria for both groups specified a small (size < 5 cm), exophytic, or subcapsular tumor located in the left or peripheral right segments of the liver (II-VI segments, Couinaud); a well-compensated cirrhosis (Child-Pugh A); and an ASA score lower than 3. In the LH group, 15 subsegmentectomies, 3 segmentectomies, and 5 left lateral sectionectomies were performed, as compared with 12 subsegmentectomies, 5 segmentectomies, and 6 left lateral sectionectomies in the OH group.

RESULTS

One patient in the LH group (4.3%) underwent conversion to laparotomy for inadequate exposition. The mean operative time was statistically longer for the LH group (LH, 148 min; OH, 125 min; p = 0.016), whereas blood transfusions (LH, 0%; OH, 17.3%; p = 0.036), Pringle maneuver (LH, 0%; OH, 21.73%; p = 0.017), mean hospital stay (LH, 8.3 days; OH, 12 days; p = 0.047), and postoperative complications (LH, 13%; OH, 47.8%; p = 0.010) were significantly greater in OH group. There was no statistically significant difference in mortality and 2-year survival rates between the two groups.

CONCLUSION

This study shows that LH for HCC in properly selected cirrhotic patients results in fewer early postoperative complications and a shorter hospital stay than the traditional OH. The 2-year survival rate was the same for LH and OH.

Laparoscopic and open treatment of hepatocellular carcinoma in patients with cirrhosis

Background

Few studies have compared survival and recurrence rates between laparoscopic and open liver resection for hepatocellular carcinoma in patients with cirrhosis.

Methods

A retrospective analysis of a prospectively maintained database of 179 liver resections performed for HCC in cirrhotic liver between 2000 and 2007 was performed.

Results

Fifty-four patients underwent a laparoscopic resection and 125 patients had open surgery. Histopathological features were largely comparable in the two groups. Tumours operated laparoscopically were smaller than those removed at open operation and laparoscopic liver resection was less extensive. Laparoscopic surgery had a lower morbidity rate than open surgery (19 versus 36·0 per cent; P = 0·020), whereas 30-day mortality was similar (2 versus 4·0 per cent; P = 0·615). After a median follow-up of 24 months, 1- and 3-year survival rates were 94 and 67 per cent in the laparoscopic group. Recurrence rates were similar after laparoscopic and open procedures (45 versus 52·5 per cent; P = 0·381), as was disease-free survival (P = 0·864).

Conclusion

Laparoscopic resection of HCC in cirrhotic liver is feasible and safe in selected patients. Adequate long-term survival and recurrence is achieved compared with open surgery, when stratified for tumour characteristics known to be related to survival outcome.

Optical transition energies for carbon nanotubes from resonant Raman spectroscopy: environment and temperature effects

This Letter reports the laser energy dependence of the Stokes and anti-Stokes Raman spectra of carbon nanotubes dispersed in aqueous solution and within solid bundles, in the energy range 1.52-2.71 eV. The electronic transition energies (E(ii)) and the radial breathing mode frequencies (omega(RBM)) are obtained for 46 different (18 metallic and 28 semiconducting) nanotubes, and the (n,m) assignment is discussed based on the observation of geometrical patterns for E(ii) versus omega(RBM) graphs. Only the low energy component of the E(M)(11) value is observed from each metallic nanotube. For a given nanotube, the resonant window is broadened and down-shifted for single wall carbon nanotube (SWNT) bundles compared to SWNTs in solution, while by increasing the temperature, the E(S)(22) energies are redshifted for S1 [(2n+m) mod 3=1] nanotubes and blueshifted for S2 [(2n+m) mod 3=2] nanotubes.

Comparative study of Raman spectroscopy in graphene and MoS2-type transition metal dichalcogenides

CONSPECTUS: Raman spectroscopy is one of the most powerful experimental tools to study graphene, since it provides much useful information for sample characterization. In this Account, we show that this technique is also convenient to study other bidimensional materials beyond graphene, and we will focus on the semiconducting transition metal dichalcogenides (MX2), specifically on MoS2 and WS2. We start by comparing the atomic structure of graphene and 2H-MX2 as a function of the number of layers in the sample. The first-order Raman active modes of each material can be predicted on the basis of their corresponding point-group symmetries. We show the analogies between graphene and 2H-MX2 in their Raman spectra. Using several excitation wavelengths in the visible range, we analyze the first- and second-order features presented by each material. These are the E2g and 2TO(K) bands in graphene (also known as the G and 2D bands, respectively) and the A1', E', and 2LA(M) bands in 2H MX2. The double-resonance processes that originate the second-order bands are different for both systems, and we will discuss them in terms of the different electronic structure and phonon dispersion curves presented by each compound. According to the electronic structure of graphene, which is a zero band gap semiconductor, the Raman spectrum is resonant for all the excitation wavelengths. Moreover, due to the linear behavior of the electronic dispersion near the K point, the double-resonance bands of graphene are dispersive, since their frequencies vary when we change the laser energy used for the sample excitation. In contrast, the semiconducting MX2 materials present an excitonic resonance at the direct gap, and consequently, the double-resonance Raman bands of MX2 are not dispersive, and only their intensities depend on the laser energy. In this sense, resonant Raman scattering experiments performed in transition metal dichalcogenides using a wide range of excitation energies can provide information about the electronic structure of these materials, which is complementary to other optical spectroscopies, such as absorption or photoluminescence. Raman spectroscopy can also be useful to address disorder in MX2 samples in a similar way as it is used in graphene. Both materials exhibit additional Raman features associated with phonons within the interior of the Brillouin zone that are activated by the presence of defects and that are not observed in pristine samples. Such is the case of the well-known D band of graphene. MX2 samples present analogous features that are clearly observed at specific excitation energies. The origins of these double-resonance Raman bands in MX2 are still subjects of current research. Finally, we discuss the suitability of Raman spectroscopy as a strain or doping sensor. Such applications of Raman spectroscopy are being extensively studied in the case of graphene, and considering its structural analogies with MX2 systems, we show how this technique can also be used to provide strain/doping information for transition metal dichalcogenides.

Excited excitonic states in 1L, 2L, 3L, and bulk WSe2 observed by resonant Raman spectroscopy

Resonant Raman spectroscopy (RRS) is a very useful tool to study physical properties of materials since it provides information about excitons and their coupling with phonons. We present in this work a RRS study of samples of WSe2 with one, two, and three layers (1L, 2L, and 3L), as well as bulk 2H-WSe2, using up to 20 different laser lines covering the visible range. The first- and second-order Raman features exhibit different resonant behavior, in agreement with the double (and triple) resonance mechanism(s). From the laser energy dependence of the Raman intensities (Raman excitation profile, or REP), we obtained the energies of the excited excitonic states and their dependence with the number of atomic layers. Our results show that Raman enhancement is much stronger for the excited A' and B' states, and this result is ascribed to the different exciton-phonon coupling with fundamental and excited excitonic states.

Intervalley scattering by acoustic phonons in two-dimensional MoS2 revealed by double-resonance Raman spectroscopy

Double-resonance Raman scattering is a sensitive probe to study the electron-phonon scattering pathways in crystals. For semiconducting two-dimensional transition-metal dichalcogenides, the double-resonance Raman process involves different valleys and phonons in the Brillouin zone, and it has not yet been fully understood. Here we present a multiple energy excitation Raman study in conjunction with density functional theory calculations that unveil the double-resonance Raman scattering process in monolayer and bulk MoS2. Results show that the frequency of some Raman features shifts when changing the excitation energy, and first-principle simulations confirm that such bands arise from distinct acoustic phonons, connecting different valley states. The double-resonance Raman process is affected by the indirect-to-direct bandgap transition, and a comparison of results in monolayer and bulk allows the assignment of each Raman feature near the M or K points of the Brillouin zone. Our work highlights the underlying physics of intervalley scattering of electrons by acoustic phonons, which is essential for valley depolarization in MoS2.

Symmetry-dependent exciton-phonon coupling in 2D and bulk MoS2 observed by resonance Raman scattering

This work describes a resonance Raman study performed on samples with one, two, and three layers (1L, 2L, 3L), and bulk MoS2, using more than 30 different laser excitation lines covering the visible range, and focusing on the intensity of the two most pronounced features of the Raman scattering spectrum of MoS2 (E2g(1) and A1g bands). The Raman excitation profiles of these bands were obtained experimentally, and it is found that the A1g feature is enhanced when the excitation laser is in resonance with A and B excitons of MoS2, while the E2g1 feature is shown to be enhanced when the excitation laser is close to 2.7 eV. We show from the symmetry analysis of the exciton-phonon interaction that the mode responsible for the E2g(1) resonance is identified as the high energy C exciton recently predicted [D. Y. Qiu, F. H. da Jornada, and S. G. Louie, Phys. Rev. Lett. 111, 216805 (2013)].

Atypical Exciton-Phonon Interactions in WS2 and WSe2 Monolayers Revealed by Resonance Raman Spectroscopy

Resonant Raman spectroscopy is a powerful tool for providing information about excitons and exciton-phonon coupling in two-dimensional materials. We present here resonant Raman experiments of single-layered WS2 and WSe2 using more than 25 laser lines. The Raman excitation profiles of both materials show unexpected differences. All Raman features of WS2 monolayers are enhanced by the first-optical excitations (with an asymmetric response for the spin-orbit related XA and XB excitons), whereas Raman bands of WSe2 are not enhanced at XA/B energies. Such an intriguing phenomenon is addressed by DFT calculations and by solving the Bethe-Salpeter equation. These two materials are very similar. They prefer the same crystal arrangement, and their electronic structure is akin, with comparable spin-orbit coupling. However, we reveal that WS2 and WSe2 exhibit quite different exciton-phonon interactions. In this sense, we demonstrate that the interaction between XC and XA excitons with phonons explains the different Raman responses of WS2 and WSe2, and the absence of Raman enhancement for the WSe2 modes at XA/B energies. These results reveal unusual exciton-phonon interactions and open new avenues for understanding the two-dimensional materials physics, where weak interactions play a key role coupling different degrees of freedom (spin, optic, and electronic).

Toxicity of single-wall carbon nanotubes functionalized with polyethylene glycol in zebrafish (Danio rerio) embryos

Single-wall carbon nanotubes functionalized with polyethylene glycol (SWCNT-PEG) are promising materials for biomedical applications such as diagnostic devices and controlled drug-release systems. However, several questions about their toxicological profile remain unanswered. Thus, the aim of this study was to investigate the action of SWCNT-PEG in Danio rerio zebrafish embryos at the molecular, physiological and morphological levels. The SWCNT used in this study were synthesized by the high-pressure carbon monoxide process, purified and then functionalized with distearoyl phosphatidylethanolamine block copolymer-PEG (molecular weight 2 kDa). The characterization process was carried out with low-resolution transmission electron microscopy, thermogravimetric analysis and Raman spectroscopy. Individual zebrafish embryos were exposed to the SWCNT-PEG. Toxic effects occurred only at the highest concentration tested (1 ppm) and included high mortality rates, delayed hatching and decreased total larval length. For all the concentrations tested, the alkaline comet assay revealed no genotoxicity, and Raman spectroscopy measurements on the histological slices revealed no intracellular nanotubes. The results shown here demonstrate that SWCNT-PEG has low toxicity in zebrafish embryos, but more studies are needed to understand what mechanisms are involved. However, the presence of residual metals is possibly among the primary mechanisms responsible for the toxic effects observed, because the purification process was not able to remove all metal contamination, as demonstrated by the thermogravimetric analysis. More attention must be given to the toxicity of these nanomaterials before they are used in biomedical applications. Copyright © 2016 John Wiley & Sons, Ltd.

Exciton antennas and concentrators from core-shell and corrugated carbon nanotube filaments of homogeneous composition

There has been renewed interest in solar concentrators and optical antennas for improvements in photovoltaic energy harvesting and new optoelectronic devices. In this work, we dielectrophoretically assemble single-walled carbon nanotubes (SWNTs) of homogeneous composition into aligned filaments that can exchange excitation energy, concentrating it to the centre of core-shell structures with radial gradients in the optical bandgap. We find an unusually sharp, reversible decay in photoemission that occurs as such filaments are cycled from ambient temperature to only 357 K, attributed to the strongly temperature-dependent second-order Auger process. Core-shell structures consisting of annular shells of mostly (6,5) SWNTs (E(g)=1.21 eV) and cores with bandgaps smaller than those of the shell (E(g)=1.17 eV (7,5)-0.98 eV (8,7)) demonstrate the concentration concept: broadband absorption in the ultraviolet-near-infrared wavelength regime provides quasi-singular photoemission at the (8,7) SWNTs. This approach demonstrates the potential of specifically designed collections of nanotubes to manipulate and concentrate excitons in unique ways.

Behavioural and physiological indicators of shelter dogs' welfare: reflections on the no-kill policy on free-ranging dogs in Italy revisited on the basis of 15 years of implementation

The Italian National Law 281 of 1991 forbids the euthanatization of free-ranging dogs, unless they have an incurable illness or are proved to be dangerous. Without neglecting the undeniable benefits of the "no-kill" policy, nevertheless it has brought about a chronic overpopulation in shelters and, as a result, higher costs of management and welfare problems since some dogs remain in the shelter for life. In 2004-2008, the Istituto Zooprofilattico Sperimentale of the Lazio and Tuscany regions carried out a survey in the Lazio Region to verify the effects of the Italian National Law 281/91 on free-ranging dog management following 15 years from its implementation. One of the aims of the study was an assessment of the welfare of dogs in a shelter sample (8 shelters out of 47 censused in the Lazio Region). 97 mixed-breed dogs were selected, their behaviour was studied and a blood sample was taken for each dog in order to determine the individual blood concentration of cortisol and the amount of oxidative damage (level of dRoms), as well as the amount of antioxidants to cope with it. Moreover, the total leukocyte count (leukogram) was accomplished. We ran general backward stepwise regression models using "level of antioxidant", "level of dRoms" and "level of serum cortisol" as dependent variables respectively. The results showed that the most important variable that improved the level of welfare of dogs consisted in having the opportunity to regularly go out of the cage for a walk, whereas other variables like gender, size of the cage (small, medium, large), being alone in the cage, and being neutered/entire, had no significant effect on the physiological indicators of welfare. Dogs that enjoyed the regular walk had a higher total antioxidant capacity, and performed a lower frequency of displacing activities and stereotyped behaviour. Moreover, oxidative stress parameters seem to be indicators well matched with behavioural indicators of stress. Thus, for the first time, markers of oxidative status are utilised for the welfare evaluation in the domestic dog. Furthermore, the results of this paper give some suggestion about how small steps can help to improve shelters and, furthermore, this paper intends to solicit the debate on the no-kill policy.

Activation of nitric oxide synthase is involved in tamoxifen-induced apoptosis of human erythroleukemia K562 cells

Tamoxifen induces apoptosis (programmed cell death) in human erythroleukemia K562 cells. Nitric oxide synthase activity and expression increased in apoptotic cells by 315% and 280%, respectively, compared to controls. The specific inhibitor of nitric oxide synthase, L-NAME, protected K562 cells from tamoxifen-induced apoptosis, whereas the nitric oxide donor, sodium nitroprusside (SNP), potentiated the apoptotic effect of the drug. In addition, 5-lipoxygenase was activated by tamoxifen and the specific enzyme inhibitor, MK886, protected K562 cells against the drug. Conversely, the 5-lipoxygenase product, 5-hydroperoxyeicosatetraenoic acid, enhanced the tamoxifen-induced apoptosis. Finally, tamoxifen altered also membrane properties of K562 cells.

One-pot in situ photochemical synthesis of graphene oxide/gold nanorod nanocomposites for surface-enhanced Raman spectroscopy

One-pot process is demonstrated that produces gold nanorods/graphene oxide nanocomposites that can be used as highly sensitive surface-enhanced Raman spectroscopy substrates.

One-dimensional character of combination modes in the resonance Raman scattering of carbon nanotubes

Resonance Raman spectroscopy with an energy tunable system is used to analyze the 600-1100 cm(-1) spectral region in single-wall carbon nanotubes. Sharp peaks are associated with the combination of zone folded optic and acoustic branches from 2D graphite. These combination modes exhibit a peculiar dependence on the excitation laser energy that is explained on the basis of a highly selective resonance process that considers phonons and electrons in low dimensional materials.

A seroepidemiological survey on Leishmania infantum infection

Findings from a seroepidemiological survey of Leishmania infantum (LI) infection are presented. Among residents in the province of Rome, 2.7% (4.4% in the city of Rome and 1% in the suburbs) of 374 adults were positive for specific LI antibodies in indirect haemoagglutination studies. Among 217 adult residents of Caltanissetta province (Sicily), 4.1% were positive for LI antibodies (4.2% in Caltanissetta city and 4% in the suburbs). Serological tests for LI antibodies were also carried out on stray dogs captured in Rome. 5% of them resulted positive. Our findings show that LI infection is moderately present in both Rome and Caltanissetta, the latter being an area of known endemicity. According to our data, LI infections are usually asymptomatic: none of the positive subjects had a history of visceral leishmaniasis, and none of the seropositive dogs showed any sign or symptom correlated to leishmaniasis.