Toward next-generation primate neuroscience: A collaboration-based strategic plan for integrative neuroimaging

Open science initiatives are creating opportunities to increase research coordination and impact in nonhuman primate (NHP) imaging. The PRIMatE Data and Resource Exchange community recently developed a collaboration-based strategic plan to advance NHP imaging as an integrative approach for multiscale neuroscience.

A map of object space in primate inferotemporal cortex

The inferotemporal (IT) cortex is responsible for object recognition, but it is unclear how the representation of visual objects is organized in this part of the brain. Areas that are selective for categories such as faces, bodies, and scenes have been found^1-5, but large parts of IT cortex lack any known specialization, raising the question of what general principle governs IT organization. Here we used functional MRI, microstimulation, electrophysiology, and deep networks to investigate the organization of macaque IT cortex. We built a low-dimensional object space to describe general objects using a feedforward deep neural network trained on object classification⁶. Responses of IT cells to a large set of objects revealed that single IT cells project incoming objects onto specific axes of this space. Anatomically, cells were clustered into four networks according to the first two components of their preferred axes, forming a map of object space. This map was repeated across three hierarchical stages of increasing view invariance, and cells that comprised these maps collectively harboured sufficient coding capacity to approximately reconstruct objects. These results provide a unified picture of IT organization in which category-selective regions are part of a coarse map of object space whose dimensions can be extracted from a deep network.

Imatinib inhibits CSF1R that stimulates proliferation of rheumatoid arthritis fibroblast-like synoviocytes

In this study, we aimed to explore the effects of imatinib on the proliferation of rheumatoid arthritis synovial cell (RA-FLS) and inflammatory responses by regulating CSF1R. Differential genes were screened via microarray analysis, followed by being analysed through the weighted co-expression network (WGCNA) network, that included module and cluster analysis. The relationship between imatinib and genes was visualized using the Search Tool for the Retrieval of Interacting Genes (STITCH) database. Expressions of mRNA and protein were determined by reverse transcription-polymerase chain reaction (RT-PCR) and Western blot, respectively. Cell viability was examined via clone formation assay, while cell cycle and apoptosis were analysed through flow cytometry analysis. The hub gene CSF1R was ultimately determined by microarray analysis and WGCNA analysis. Colony-stimulating-factor receptor-1 (SF1R) was highly expressed in rheumatoid arthritis tissues and cells, and CSF1R over-expression could promote inflammatory responses. Moreover, CSF1R could promote RA-FLS proliferation, inhibit apoptosis and accelerate the cell cycle. The targeting relationship between imatinib and CSF1R was also validated in this study. Imatinib attenuated RA-FLS inflammation in a concentration-dependent manner. Meanwhile, imatinib could inhibit RA-FLS proliferation and promote apoptosis, ultimately reducing the damage of RA-FLS. Over-expression of CSF1R accelerated the cell cycle and proliferation of RA-FLS, while inhibiting cell apoptosis. Conversely, imatinib could significantly restrain the cell cycle and viability of RA-FLS and accelerated apoptosis via suppression of CSF1R expression. Further, histological and serological assay investigated and proved the proinflammatory effects of CSF1R in RA rabbits.

Representation of multiple objects in macaque category-selective areas

Object recognition in the natural world usually occurs in the presence of multiple surrounding objects, but responses of neurons in inferotemporal (IT) cortex, the large brain area responsible for object recognition, have mostly been studied only to isolated objects. We study rules governing responses to multiple objects by cells in two category-selective regions of macaque IT cortex, the middle lateral face patch (ML) and the middle body patch (MB). We find that responses of single ML and MB cells to pairs of objects can be explained by the widely accepted framework of normalization, with one added ingredient: homogeneous category selectivity of neighboring neurons forming the normalization pool. This rule leads to winner-take-all, contralateral-take-all, or weighted averaging behavior in single cells, depending on the category, spatial configuration, and relative contrast of the two objects. The winner-take-all behavior suggests a potential mechanism for clutter-invariant representation of face and bodies under certain conditions.

Inferotemporal cortex (IT) neurons respond to specific objects but the precise neural mechanisms for clutter-invariant representation is not known. Here the authors show that face and body patch IT neurons respond to multiple objects with winner-take-all, contralateral-take-all or weighted averaging depending on the stimulus properties.

Controlling transmembrane protein concentration and orientation in supported lipid bilayers

The trans-membrane protein - proteorhodopsin (pR) has been incorporated into supported lipid bilayers (SLB). In-plane electric fields have been used to manipulate the orientation and concentration of these proteins, within the SLB, through electrophoresis leading to a 25-fold increase concentration of pR.

Intrinsic Ferromagnetism in the Diluted Magnetic Semiconductor Co:TiO_{2}

Here we present a study of magnetism in Co_{0.05}Ti_{0.95}O_{2-δ} anatase films grown by pulsed laser deposition under a variety of oxygen partial pressures and deposition rates. Energy-dispersive spectrometry and transmission electron microscopy analyses indicate that a high deposition rate leads to a homogeneous microstructure, while a very low rate or postannealing results in cobalt clustering. Depth resolved low-energy muon spin rotation experiments show that films grown at a low oxygen partial pressure (≈10^{-6}  torr) with a uniform structure are fully magnetic, indicating intrinsic ferromagnetism. First principles calculations identify the beneficial role of low oxygen partial pressure in the realization of uniform carrier-mediated ferromagnetism. This work demonstrates that Co:TiO_{2} is an intrinsic diluted magnetic semiconductor.

Breast cancer incidence and mortality: trends over 40 years among women in Shanghai, China

BACKGROUND

Breast cancer incidence rates are increasing among Asian women, likely due to the changes in risk factors caused by globalization. Trends in breast cancer rates among Chinese women may differ from other Asian regions due to the implementation of a nationwide family planning program and resulting changes in women's reproductive practices. Appraisal of cancer trends can direct cancer control and public health planning, but relevant studies in China are scarce due to a lack of long-term data. We sought to evaluate secular time trends in breast cancer incidence and mortality using 40 years of cancer registry data for women in urban Shanghai.

MATERIALS AND METHODS

Data on invasive breast cancer incidence and mortality were collected by the Shanghai Cancer Registry. Age-standardized rates (ASRs) for incidence and mortality were calculated using the Segi/Doll 1960 world standard population. Age, period, and birth cohort effects were evaluated using age-period-cohort (APC) Poisson regression models. Overall linear trends, interpreted as the estimated annual percentage change (EAPC), were derived from the net drift in age-drift models.

RESULTS

A total of 53 885 breast cancer cases and 17 235 breast cancer-specific deaths were documented among women in urban Shanghai between 1 January 1973 and 31 December 2012. Breast cancer incidence and mortality ASRs increased by 141.2% and 26.6%, respectively. Significant age, cohort, and period effects were identified in both incidence and mortality APC models; cohort effects were pronounced. Overall, a substantial increase in breast cancer incidence (EAPC = 2.96%/year) and a moderate increase in breast cancer mortality (EAPC = 0.87%/year) was observed. A notable downward trend in mortality was identified among younger women born after 1960.

CONCLUSIONS

Forty years of cancer registry data document a tremendous increase in incidence and a slight increase in mortality for breast cancer among women in Shanghai. Effective, appropriate, and affordable breast cancer prevention and control strategies are urgently needed in China.

The Effect of Depo Medroxyprogesterone Acetate (DMPA) on Cerebral Food Motivation Centers: A Pilot Study using Functional Magnetic Resonance Imaging

OBJECTIVE

The primary objective is to examine activation of food motivation centers in the brain before and 8 weeks after depo medroxyprogesterone acetate (DMPA) administration.

STUDY DESIGN

This prospective experimental pilot study examined the effects of DMPA on food motivation centers utilizing functional magnetic resonance imaging (fMRI) in eight nonobese, ovulatory subjects. fMRI blood oxygen level dependent (BOLD) signal was measured using a 3-Tesla Scanner while participants viewed images of high-calorie foods, low-calorie foods and nonfood objects. fMRI scans were performed at baseline and 8 weeks after participants received one intramuscular dose of DMPA 150 mg. fMRI data were analyzed using the FMRIB Software Library. Changes in adiposity and circulating leptin and ghrelin levels were also measured.

RESULTS

There was a greater BOLD signal response to food cues in brain regions associated with food motivation (anterior cingulate gyrus, orbitofrontal cortex) 8 weeks after DMPA administration compared to baseline (z>2.3, p<.05 whole-brain analysis clustered corrected). No statistically significant change was detected in circulating leptin or ghrelin levels or fat mass 8 weeks after DMPA administration.

CONCLUSION

Analysis of differences in food motivation may guide the development of interventions to prevent weight gain in DMPA users.

IMPLICATIONS

These data support a neural origin as one of the mechanisms underlying weight gain in DMPA users and may guide future research examining weight gain and contraception.

Using an achiasmic human visual system to quantify the relationship between the fMRI BOLD signal and neural response

Achiasma in humans causes gross mis-wiring of the retinal-fugal projection, resulting in overlapped cortical representations of left and right visual hemifields. We show that in areas V1-V3 this overlap is due to two co-located but non-interacting populations of neurons, each with a receptive field serving only one hemifield. Importantly, the two populations share the same local vascular control, resulting in a unique organization useful for quantifying the relationship between neural and fMRI BOLD responses without direct measurement of neural activity. Specifically, we can non-invasively double local neural responses by stimulating both neuronal populations with identical stimuli presented symmetrically across the vertical meridian to both visual hemifields, versus one population by stimulating in one hemifield. Measurements from a series of such doubling experiments show that the amplitude of BOLD response is proportional to approximately 0.5 power of the underlying neural response. Reanalyzing published data shows that this inferred relationship is general.

Quantitative assessment of new MRI-based measurements to differentiate low and high stages of pelvic organ prolapse using support vector machines

INTRODUCTION AND HYPOTHESIS

The objective of this study was to quantitatively assess the ability of new MRI-based measurements to differentiate low and high stages of pelvic organ prolapse. New measurements representing pelvic structural characteristics are proposed and analyzed using support vector machines (SVM).

METHODS

This retrospective study used data from 207 women with different types and stages of prolapse. Their demographic information, clinical history, and dynamic MRI data were obtained from the database. New MRI measurements were extracted and analyzed based on these reference lines: pubococcygeal line (PCL), mid-pubic line (MPL), true conjugate line (TCL), obstetric conjugate line (OCL), and diagonal conjugate line (DCL). A classification model using SVM was designed to assess the impact of the features (variables) in classifying prolapse into low or high stage.

RESULTS

The classification model using SVM can accurately identified anterior prolapse with very high accuracy (>0.90), and apical and posterior prolapse with good accuracy (0.80 - 0.90). Two newly proposed MRI-based features were found to be significant in the identification of anterior and posterior prolapse: the angle between TCL and MPL for anterior prolapse, and the angle between DCL and PCL for posterior prolapse. The overall accuracy of posterior prolapse identification increased from 47% to 80% when the newly proposed MRI-based features were taken into consideration.

CONCLUSIONS

The proposed MRI-based measurements are effective in differentiating low and high stages of pelvic organ prolapse, particularly for posterior prolapse.

Radial-tangential anisotropy of crowding in the early visual areas

Crowding, the inability to recognize an individual object in clutter (Bouma H. Nature 226: 177-178, 1970), is considered a major impediment to object recognition in peripheral vision. Despite its significance, the cortical loci of crowding are not well understood. In particular, the role of the primary visual cortex (V1) remains unclear. Here we utilize a diagnostic feature of crowding to identify the earliest cortical locus of crowding. Controlling for other factors, radially arranged flankers induce more crowding than tangentially arranged ones (Toet A, Levi DM. Vision Res 32: 1349-1357, 1992). We used functional magnetic resonance imaging (fMRI) to measure the change in mean blood oxygenation level-dependent (BOLD) response due to the addition of a middle letter between a pair of radially or tangentially arranged flankers. Consistent with the previous finding that crowding is associated with a reduced BOLD response [Millin R, Arman AC, Chung ST, Tjan BS. Cereb Cortex (July 5, 2013). doi:10.1093/cercor/bht159], we found that the BOLD signal evoked by the middle letter depended on the arrangement of the flankers: less BOLD response was associated with adding the middle letter between radially arranged flankers compared with adding it between tangentially arranged flankers. This anisotropy in BOLD response was present as early as V1 and remained significant in downstream areas. The effect was observed while subjects' attention was diverted away from the testing stimuli. Contrast detection threshold for the middle letter was unaffected by flanker arrangement, ruling out surround suppression of contrast response as a major factor in the observed BOLD anisotropy. Our findings support the view that V1 contributes to crowding.

Correlation of vision loss with tactile-evoked V1 responses in retinitis pigmentosa

Neuroimaging studies have shown that the visual cortex of visually impaired humans is active during tactile tasks. We sought to determine if this cross-modal activation in the primary visual cortex is correlated with vision loss in individuals with retinitis pigmentosa (RP), an inherited degenerative photoreceptor disease that progressively diminishes vision later in life. RP and sighted subjects completed three tactile tasks: a symmetry discrimination task, a Braille-dot counting task, and a sandpaper roughness discrimination task. We measured tactile-evoked blood oxygenation level dependent (BOLD) responses using functional magnetic resonance imaging (fMRI). For each subject, we quantified the cortical extent of the tactile-evoked response by the proportion of modulated voxels within the primary visual cortex (V1) and its strength by the mean absolute modulation amplitude of the modulated voxels. We characterized vision loss in terms of visual acuity and the areal proportion of V1 that corresponds to the preserved visual field. Visual acuity and proportion of the preserved visual field both had a highly significant effect on the cortical extent of the V1 BOLD response to tactile stimulation, while visual acuity also had a significant effect on the strength of the V1 response. These effects of vision loss on cross-modal responses were reliable despite high inter-subject variability. Controlling for task-evoked responses in the primary somatosensory cortex (S1) across subjects further strengthened the effects of vision loss on cross-model responses in V1. We propose that such cross-modal responses in V1 and other visual areas may be used as a cortically localized biomarker to account for individual differences in visual performance following sight recovery treatments.

On the roles of graphene oxide doping for enhanced supercurrent in MgB2 based superconductors

Due to their graphene-like properties after oxygen reduction, incorporation of graphene oxide (GO) sheets into correlated-electron materials offers a new pathway for tailoring their properties. Fabricating GO nanocomposites with polycrystalline MgB2 superconductors leads to an order of magnitude enhancement of the supercurrent at 5 K/8 T and 20 K/4 T. Herein, we introduce a novel experimental approach to overcome the formidable challenge of performing quantitative microscopy and microanalysis of such composites, so as to unveil how GO doping influences the structure and hence the material properties. Atom probe microscopy and electron microscopy were used to directly image the GO within the MgB2, and we combined these data with computational simulations to derive the property-enhancing mechanisms. Our results reveal synergetic effects of GO, namely, via localized atomic (carbon and oxygen) doping as well as texturing of the crystals, which provide both inter- and intra-granular flux pinning. This study opens up new insights into how low-dimensional nanostructures can be integrated into composites to modify the overall properties, using a methodology amenable to a wide range of applications.

Assessment of a semiautomated pelvic floor measurement model for evaluating pelvic organ prolapse on MRI

INTRODUCTION AND HYPOTHESIS

The objective of this study was to assess the performance of a semiautomated pelvic floor measurement algorithmic model on dynamic magnetic resonance imaging (MRI) images compared with manual pelvic floor measurements for pelvic organ prolapse (POP) evaluation.

METHODS

We examined 15 MRIs along the midsagittal view. Five reference points used for pelvic floor measurements were identified both manually and using our semiautomated measurement model. The two processes were compared in terms of accuracy and precision.

RESULTS

The semiautomated pelvic floor measurement model provided highly consistent and accurate locations for all reference points on MRI. Results also showed that the model can identify the reference points faster than the manual-point identification process.

CONCLUSION

The semiautomated pelvic floor measurement model can be used to facilitate and improve the process of pelvic floor measurements on MRI. This will enable high throughput analysis of MRI data to improve the correlation analysis with clinical outcomes and potentially improve POP assessment.

Visual cortex activation induced by tactile stimulation in late-blind individuals with retinitis pigmentosa

The inter-subject variability of visual cortex reorganization was assessed in late-blind subjects suffering from retinitis pigmentosa (RP), a degenerative retinal disease that results in tunnel vision and eventual loss of sight. fMRI BOLD responses were measured as blindfolded RP and blindfolded sighted control groups completed a tactile discrimination task (in which subjects determined the relative roughness of sandpaper discs) during successive scans in a 3T Siemens scanner. Resulting activation patterns were compared between the two groups in a whole-brain analysis. We found that vision deprivation leads to elevated activation of the visual cortex elicited with tactile stimuli, and the degree of activation correlates with the degree of visual field loss: higher visual cortex activation is associated with greater vision loss. The location of vision loss in the visual field also correlates with the location of tactile responses in the visual cortex, with greater peripheral vision loss leading to stronger activation in the peripheral of V1. Visual cortex responses to tactile stimuli may hence be used as a diagnostic marker in determining the extent of an individual's vision loss and tracking sight recovery following treatments.

A novel single nucleotide polymorphism (SNP) of the <i>IGF1R</i> gene and the association with growth traits in yak (Brief Report)

Abstract. The insulin-like growth factor-I (IGF1) is a peptide growth factor that exerts mitogenic and metabolic activities, which are regulators of growth, survival and cell differentiation in a number of cell and tissue types. To elicit its effects, IGF1 must bind its receptors. The insulinlike growth factor 1 receptor (IGF1R) is similar to insulin receptor (INSR) and it mediates the growth-promoting effect of IGF1. The IGF1R gene, therefore, was selected as a biological candidate gene for growth, body composition, metabolic, and skeletal traits in animals (Rothschild et al. 1997). By now, no polymorphism of yak (Bos grunniensL) IGF1R gene is reported. In the present paper, the partial exon 1 region of IGF1R was screened to detect the SNPs in Chinese yak breeds. Associations of SNP of IGF1R with growth traits were analysed.

Diphenhydramine modulates cytokines and induces apoptosis in experimental acute pancreatitis

In this study, we investigated the therapeutic potential of diphenhydramine (DPH), a H(1) receptor antagonist, on taurocholate-induced acute pancreatitis and the underlying mechanisms involved. Rats were randomly divided into sham-operated, model, DPH-treated, octreotide-treated and the DPH plus octreotide combination therapy groups (n = 30 per group). Animals were sacrificed 3, 6 and 24 h after modeling and drug administration (n = 10 per time point) and sera, pancreas and lungs were harvested for further studies. DPH and octreotide monotherapy relieved histopathological injuries in multiple organs when compared to the model group. Combination therapy (DPH + octreotide) demonstrated better therapeutic potential than monotherapy. Data indicated that combination therapy had a better ability to reduce average mortality rates in rats, decrease the number of inflammatory cells, attenuate necrosis, upregulate the levels of amylase, TNF-alpha and IL-8 and downregulate the levels of IL-10 in the serum. Moreover, enhanced expression of Bax in the pancreas and lung were recorded suggesting a pro-apoptotic mechanism involved in the therapeutic potential of DPH. Our study demonstrated the therapeutic potential of DPH in acute pancreatitis and suggested a novel strategy for clinical management of this disease.

Perceptual learning improves contrast sensitivity of V1 neurons in cats

BACKGROUND

Perceptual learning has been documented in adult humans over a wide range of tasks. Although the often-observed specificity of learning is generally interpreted as evidence for training-induced plasticity in early cortical areas, physiological evidence for training-induced changes in early visual cortical areas is modest, despite reports of learning-induced changes of cortical activities in fMRI studies. To reveal the physiological bases of perceptual learning, we combined psychophysical measurements with extracellular single-unit recording under anesthetized preparations and examined the effects of training in grating orientation identification on both perceptual and neuronal contrast sensitivity functions of cats.

RESULTS

We have found that training significantly improved perceptual contrast sensitivity of the cats to gratings with spatial frequencies near the "trained" spatial frequency, with stronger effects in the trained eye. Consistent with behavioral assessments, the mean contrast sensitivity of neurons recorded from V1 of the trained cats was significantly higher than that of neurons recorded from the untrained cats. Furthermore, in the trained cats, the contrast sensitivity of V1 neurons responding preferentially to stimuli presented via the trained eyes was significantly greater than that of neurons responding preferentially to stimuli presented via the "untrained" eyes. The effect was confined to the trained spatial frequencies. In both trained and untrained cats, the neuronal contrast sensitivity functions derived from the contrast sensitivity of the individual neurons were highly correlated with behaviorally determined perceptual contrast sensitivity functions.

CONCLUSIONS

We suggest that training-induced neuronal contrast gain in area V1 underlies behaviorally determined perceptual contrast sensitivity improvements.

Ultra-sensitive detection of biomarkers and applications in pharmaceutical discovery and development. Example application to rat cardiac troponin I assay via nanoparticle probes

e14594

Although specific to heart, rat cardiac troponin I (cTnI) is an example of an important biomarker for assessing drug-induced cardiotoxicity in animal models used in various phases of drug discovery and development. Current commercially available assays can only detect 10 ∼ 100 pg/mL in serum at the lowest limits. To improve the sensitivity of rat cTnI assay, we have developed a generically applicable, microarray based nano-probe test. Our rat cTnI assay algorithm uses a multi-step robotic process, which relies on non- isotropically oriented antibodies on functionalized glass as multiplexed microarrays to capture cTnI from serum. Functionalized, 130 angstrom diameter gold nano-probes (measured by static light scattering, 5 nm S.D.) also bind to the troponin through a molecular-scale complex containing antibodies. The troponin-bound molecular complex is then quantified through silver enhancement of the functionalized gold. Assays in this format can be rapidly configured and implemented for a wide array of potential biomarkers. For cTnI we have demonstrated a robust and ultra-sensitive assay with an LOD of less than 500 femtograms of rat cTnI per mL serum, and an overall CV of less than 20%. The assay also shows very low background, a broad dynamic range and over 3 logs of linear dose response. As an example of the potential of high sensitivity, the nanoparticle-based rat cTnI assay could significantly increase the effectiveness of measuring drug-induced heart damage at very low drug dosages and early times. Such sensitive and early measurements can improve examination of the safety of drug candidates while correspondingly reducing drug development time and cost.

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Breast cancer mortality trends in the WEST compared to the EAST: lives gained, lives lost

Abstract #6082

INTRODUCTION: Breast Cancer (BrCa) Mortality trends between 1950 – 2005 were reviewed between the Western (WEST) and Eastern Asian (EAST) countries, with the objective to gain understanding between therapeutic and diagnostic interventions and underlying epidemiology factors determining BrCa outcomes.&#x2028; METHODOLOGY: We compared BrCa mortality trends in the WEST (Canada, UK, USA) and in the EAST (Japan and China-Shanghai). Data were obtained from WHO - IARC, Lyon (Canada, USA, UK, Japan); and from the Shanghai Cancer Registry (China-Shanghai). We analyzed age-standardized annual mortality rates per 100,000 / population (as per 1960 world standard population). Mortality trends were expressed relative to the baseline (year 1950 for all, year 1973 for China-Sha).&#x2028; RESULTS: The baseline mortality rates were: 22.5 for Canada; 23.5 for UK; 21.6 for USA, 4.1 for Japan; and 7.3 for China-Shanghai.&#x2028; &#x2028; CONCLUSION. These data confirm a substantial mortality reduction in the WEST evident after the 1980's - 1990's, likely reflecting the interaction of diagnostic and therapeutic interventions (mammography, education, systemic / locoregional therapies, etc). The different timing and extent of mortality reduction in the WEST probably reflect different degree of implementation of the interactive factors.&#x2028; On the other hand, mortality is increasing in the EAST, in parallel with the “westernization” of those regions (industrialization, diet, etc, Ref. [NEJM; 2008:358;3)]. For the EAST, our data also support a correlation between the timing / extent of the “westernization” and mortality trend dynamics (i.e. mortality increase in Japan 20 years earlier than China).

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 6082.

A prototype ultrasound-guided laparoscopic radiofrequency ablation system

BACKGROUND

Advanced laparoscopic procedures, particularly laparoscopic liver resection and ablation, may benefit from image-guided surgery techniques that involve interactive three-dimensional imaging and instrument tracking.

METHODS

A prototype system for laparoscopic ultrasound-guided radiofrequency ablation was designed and implemented. This system uses an infrared camera to track instruments and runs on a personal computer. Features of the system include spatially registered ultrasound visualization, volume reconstruction, and interactive targeting. Targeting of accuracy studies was performed by directing a tracked needle to a phantom target.

RESULTS

Ultrasound data collection and volume reconstruction can be achieved within minutes and interactively reviewed by the surgeon. Early results with phantom experiments demonstrate a targeting accuracy of 5 to 10 mm.

CONCLUSIONS

These results support the further development of this and similar image-guided surgery systems for specific laparoscopic procedures. Eventually, rigorous clinical evaluation will be necessary to prove their value.