Comparison of Hysteroscopic Cesarean Scar Defect Repair with 26 Fr Resectoscope and 16 Fr Mini-resectoscope: A Prospective Pilot Study.

STUDY OBJECTIVE: Several studies have been published on hysteroscopic treatment of cesarean scar defect using the 26 Fr resectoscope. This study compared the effects of the 26 Fr resectoscope with those of the 16 Fr mini-resectoscope in terms of efficacy, safety profile, and peri- and postoperative complications. DESIGN: A prospective cohort study. SETTING: Tertiary care university hospital (S. Orsola-Malpighi, Bologna, Italy). PATIENTS: Three hundred and nine women having symptoms and with a cesarean scar defect diagnosis were divided into 2 groups according to a temporal criterion: from March 2012 to March 2015, 155 consecutive women (control group) underwent isthmoplasty with the 26 Fr resectoscope (Karl Storz, Tuttlingen, Germany), whereas from April 2015 to March 2018, 154 consecutive women (study group) underwent isthmoplasty with the 16 Fr mini-resectoscope (Gubbini system, Tontarra Medizintechnik, Tuttlingen, Germany). INTERVENTIONS: One hundred and fifty-five women (control group) underwent isthmoplasty with the 26 Fr resectoscope, and 154 women (study group) underwent isthmoplasty with the 16 Fr mini-resectoscope. The so-called "channel-like" 360° endocervical resection technique was applied. MEASUREMENTS AND MAIN RESULTS: The isthmoplasty time with the 2 resectoscopes, excluding cervical dilatation, was similar (p = .25), whereas the overall surgical time was shorter in the case of the mini-resectoscope. The use of the 16 Fr mini-resectoscope was significantly associated with a reduced volume of distension medium used (p <.001) and a lower fluid absorption (p <.001). A significant increase (p = .01) in postoperative complications in the control group (9/155; 5.8%) compared with the study group (1/154; 0.7%) was also found. No significant reduction in discharge time was observed between the 2 groups (p = .13). Patient satisfaction immediately after surgery was significantly higher (p <.001) in the study group than in the control group. CONCLUSION: Isthmoplasty with a 16 Fr mini-resectoscope seems to be as effective as isthmoplasty with a 26 Fr resectoscope in reducing postmenstrual abnormal uterine bleeding and suprapubic pelvic pain. It is associated with a significant reduction in overall surgical time owing to the non-necessity of performing cervical dilatation. The 16 Fr mini-resectoscope facilitates surgery in small anatomical spaces such as the cervical canal and reduces the complication rate linked to blind maneuvers not respecting the uterine anatomy.

Comparative anatomical study on the role of zygomatic osteotomy in the extradural subtemporal approach to the clival region, when less is more.

PURPOSE: A great concern in performing the extradural subtemporal approach (ESTA) is the evaluation of the actual advantage provided by zygomatic osteotomy (ZO). Complications related to zygomatic dissection have been widely reported in the literature, making it of paramount importance to balance the actual need to perform it, against the risk of maneuver-related morbidity. Authors comparatively analyze the putative advantage provided by ZO in the ESTA in terms of anatomic exposure and surgical operability. Technical limits and potentials are critically revised and discussed. METHODS: A comparative microanatomical laboratory investigation was conducted. The operability score (OS) was applied for quantitative analysis of surgical operability. RESULTS: ZO was found to provide a weakly significant improvement in the surgical angle of attack (p value 0.01) (mean increase 3°). Maneuverability arch (MAC) increase related to ZO did not reach statistical significance (p value 0.09) (mean increase 2°). The variations provided by MAC increase on the conizing effect (CE) did not lead to an actual advantage in the real surgical scenario, modifying the vision area (VA) in terms of reduction of central vision area (CA) in favor of an increase of peripheral vision area (PA) only in the most caudal part of the surgical field. Ultimately, ZO did not influence the overall OS, scoring both ESTA-ZO+ and ESTA-ZO- 2 out of 3. CONCLUSION: In the ESTA, ZO does not provide an actual significant advantage in terms of surgical operability on clival and paraclival areas.

A comparative study of surgical outcomes using a Colorado microdissection needle versus standard-size needle electrocautery in one-stage hypospadias repair using a transverse preputial island flap.

BACKGROUND: The purpose of this study was to compare the surgical outcomes of a Colorado microdissection needle (CMN) with that of a standard-size electrocautery needle in one-stage hypospadias repair using a transverse preputial island flap (TPIF). METHODS: The records of patients who received hypospadias repair from September 2012 to October 2013 were retrospectively reviewed. Patients were divided into a group that received repair using a CMN and those in which a standard-size electrocautery needle was used. Data collected and compared included age, types of hypospadias, duration of surgery, intraoperative blood loss, and postoperative edema and complications. RESULTS: There were 51 patients in the CMN group and 44 in the standard needle group, and the groups were similar with respect to age and type of hypospadias. The median surgery time for the CMN group was significantly shorter than that of the standard group (15.7 minutes vs. 20.6 minutes, respectively, P<0.001). At postoperative day 7 and day 30, the CMN group had significantly less patients with edema than the standard needle group (31.4% vs. 65.9%, P<0.01; and 37.3% vs. 79.5%, P<0.001, respectively). The overall complication rate has no significant difference between two groups. CONCLUSIONS: The use of CMN for tissue dissection and separation in hypospadias repair can facilitate foreskin degloving, shape the flap in a more efficient way, and help maintain adequate blood supply for the new urethra and its skin coverage.

Comparison of Colorado Microdissection Needle Versus Scalpel Incision for Aesthetic Upper and Lower Eyelid Blepharoplasty.

PURPOSE: Traditionally, eyelid skin incisions with electro-cautery devices have been avoided due to the concerns of aesthetically unacceptable scar formation. The purpose of this study is to compare ecchymosis, cosmesis, and histologic tissue damage of incisions made with a scalpel or Colorado needle in patients undergoing upper and lower aesthetic blepharoplasty. To the best of authors' knowledge, no previous study has been performed before to compare these 2 modalities in aesthetic blepharoplasty surgery. METHODS: This is a multicenter, prospective, interventional, comparative case series. The study protocol was approved by Institutional Review Board in each institution. Patients underwent bilateral upper and/or transcutaneous lower blepharoplasty with 1 side randomly selected for skin incision with the scalpel, the other side with the Colorado needle. Ecchymosis was evaluated using a 10-point Likert scale and the wounds using a Hollander score. The margins of excised tissues were evaluated histologically. RESULTS: A total of 254 eyelids of 101 patients were included in the study. No significant difference was observed in ecchymosis on postoperative day 1 and 7 and scar cosmesis on day 30 and 180 between the 2 techniques. Histologically, necrosis was noted only with the Colorado needle sides (p = 0.001). No adverse events occurred on the Colorado needle side at any time after surgery. CONCLUSIONS: No clinical difference is noted between Colorado needle and scalpel incisions in terms of ecchymosis and scar cosmesis after aesthetic blepharoplasty.

A multicentre study of the precision and accuracy of the TruSlice and TruSlice Digital histological dissection devices.

BACKGROUND: Five key factors enabling a good surgical grossing technique include a flat uniformly perpendicular specimen cutting face, appropriate immobilisation of the tissue specimen during grossing, good visualisation of the cutting tissue face, sharp cutting knives and the grossing knife action. TruSlice and TruSlice Digital are new innovative tools based on a guillotine configuration. The TruSlice has plastic inserts whilst the TruSlice Digital has an electronic micrometre attached: both features enable these dissection factors to be controlled. The devices were assessed in five hospitals in the UK. MATERIAL AND METHODS: A total of 267 fixed tissue samples from 23 tissue types were analysed, principally the breast (n = 32) skin (30), rectum (28), colon (27) and cervix (17). Precision and accuracy were evaluated by measuring the defined thickness, and the consistency of achieving the defined thickness of tissue samples taken respectively. Both parameters were expressed as a total percentage of compliance for the cohort of samples accessed. RESULTS: Overall, the mean (standard deviation) score for precision was 81 (11) % whilst the accuracy score was 82 (11) % (both p < 0.05, chi-squared test), although this varied with type of tissue. Accuracy and precision were strongly correlated (rp = 0.83, p < 0.001). CONCLUSION: The TruSlice Digital devices offer an assured precision and accuracy performance which is reproducible across an assortment of tissue types. The use of a micrometre to set tissue slice thickness is innovative and should comply with laboratory accreditation requirements, alleviating concerns of how to tackle issues such as the 'measurement of uncertainty' at the grossing bench.

Position-Specific Gene Expression Analysis Using a Microgram Dissection Method Combined with On-Bead cDNA Library Construction.

Gene expression analysis is a key technology that is used to understand living systems. Multicellular organisms, including plants, are composed of various tissues and cell types, each of which exhibits a unique gene expression pattern. However, because of their rigid cell walls, plant cells are difficult to isolate from the whole plant. Although laser dissection has been used to circumvent this problem, the plant sample needs to be fixed beforehand, which presents several problems. In the present study, we developed an alternative method to conduct highly reliable gene expression profiling. First, we assembled a dissection apparatus that used a narrow, sharpened needle to dissect out a microsample of fresh plant tissue (0.1-0.2 mm on each side) automatically from a target site within a short time frame. Then, we optimized a protocol to synthesize a high-quality cDNA library on magnetic beads using a single microsample. The cDNA library was amplified and subjected to high-throughput sequencing. In this way, a stable and reliable system was developed to conduct gene expression profiling in small regions of a plant. The system was used to analyze the gene expression patterns at successive 50 µm intervals in the shoot apex of a 4-day-old Arabidopsis seedling. Clustering analysis of the data demonstrated that two small, adjacent domains, the shoot apical meristem and the leaf primordia, were clearly distinguishable. This system should be broadly applicable in the investigation of the spatial organization of gene expression in various contexts.

Development of new and accurate measurement devices (TruSlice and TruSlice Digital) for use in histological dissection: an attempt to improve specimen dissection precision.

Histological dissection of human tissue has relied on conventional procedures, which have largely remained unchanged for decades. Practices to determine measurement parameters employed in these procedures have largely relied on the use of rulers and weighing scales. It is well documented in the scientific literature that both fixation and processing of tissue can significantly affect the viability of the of tissue sections both for tinctorial and immunocytochemical investigations. Both of these factors can be compounded in their negative effects by inappropriate sampling of tissue at histological cut up. There are five key factors to ensure good surgical grossing technique, flat uniformly perpendicular specimen cutting face, appropriate immobilisation of the tissue specimen during grossing, good visualisation of the cutting tissue face, sharp cutting knives and the grossing knife action. Meeting these factors implies the devices are fit for purpose. Here we describe an innovative approach to designing cut up devices to improve accuracy and precision, which take these five key requirements into consideration. The devices showed accuracy and precision, enabling tissue slices to be produced in a uniformly perpendicular fashion to within 2 mm in thickness and to enable consistency and reproducibility of performance across a series of tissue types. The application of a digital rule on one of these devices ensures accuracy and also enables quality control issues to be clearly assessed. As cellular pathology laboratories conform to ever increasing standards of compliance and performance in practice, the advent of assured precision and accuracy at cut up is awaited. Recommendations from accreditation bodies such as the United Kingdom Accreditation Service (UKAS) continue to push for improvements in this area of histological investigation. These newly designed devices may give the answers to these requirements and provide the impetus for a new generation of innovative equipment for histological dissection.

Peritubular dentin, a highly mineralized, non-collagenous, component of dentin: isolation and capture by laser microdissection.

We demonstrate the capability and technique to perform microdissection and isolation of select regions of untreated, mineralized dentin using laser capture. Dentin is a complex, non-homogeneous tissue comprised of a mineralized collagenous matrix (intertubular dentin [ITD]), odontoblastic processes (ODPs), a void space (tubules) that forms within the ITD left behind by the retraction of ODPs during dentin maturation, and a highly mineralized non-collagenous component that exists at the interface between the tubules and ITD known as peritubular dentin (PTD). PTD forms as the dentin matures. The ODPs retract toward the direction of the pulp; leaving very little PTD at either the DEJ or near the pulp. Statistical analysis of thin cross-sections of coronal bovine dentin imaged by light microscopy reveal that the area occupied by PTD >50%. To examine the nature of PTD and its relation to both the tubules and ITD, we devised a series of steps to carefully prepare sections of coronal bovine dentin so that areas of the dentin tissue could be cut and isolated for further analysis. We demonstrate that it is possible to selectively isolate targeted regions of dentin for analysis and that high resolution analysis of such sections can be performed using electron microscopy. Results show that the mineralized PTD has a different texture than mineralized ITD and that there is a distinct boundary between the PTD and the ITD. Selective isolation of mineralized tissue components for further analytical study opens the door for the investigation of similar enigmatic mineralized structures.

Blunt microdissection for endovascular treatment of infrainguinal chronic total occlusions.

PURPOSE: To present a systematic safety evaluation of the CrossBoss blunt microdissection catheter for crossing peripheral chronic total occlusions (CTOs). METHODS: Between July 2010 and July 2011, 15 patients (all men; mean age 60.7±9.1 years) underwent endovascular treatment of 17 infrainguinal CTOs that were resistant to guidewire passage, so the blunt microdissection catheter was employed to recanalize the artery. Fourteen lesions were de novo and 3 were in-stent restenoses. Sixteen lesions were in the superficial femoral artery; 8 of 17 CTOs were TASC II type D. Extensive calcification was present in 12 lesions. Mean lesion length was 182.9±66.2 mm (range 57-296). RESULTS: Procedural success was 100% and successful crossing without the use of a re-entry device (technical success) was achieved in 15 cases. Twelve lesions were stented. Average fluoroscopy time was 36.5±21.2 minutes (143.8±76.9 Gy*cm (2) radiaton dose area product), during which a mean 172.1±62.2 mL of iodinated contrast were used. Two patients had access site hematomas that were treated conservatively, and there was no perforation, distal embolization, amputation, or need for urgent revascularization. During the mean follow-up of 11.4±0.1 months, 1 patient died, and none required an amputation or surgical revascularization. There was a significant improvement in ankle-brachial index (0.6±0.1 to 0.8±0.2, p=0.001) and symptoms as assessed by Rutherford class at 1 year. Four of 17 limbs required secondary revascularization procedures within 1 year. CONCLUSION: The CrossBoss blunt microdissection catheter facilitated successful crossing of CTOs in patients with infrainguinal lesions following unsuccessful guidewire crossing, with an acceptably low rate of periprocedural complications and significant improvement in symptoms.

The utility of endoscopic radical resection with microdissection electrodes for lingual thyroglossal duct cysts.

BACKGROUND: Lingual thyroglossal duct cysts (LTGDCs) are very rare and liable to be misdiagnosed as simple vallecular or mucus retention cysts. We recognized the importance of complete resection by means of the Sistrunk operation and applied the revised surgical technique to the treatment of LTGDCs. The aim of this study was to evaluate the results of surgical management of LTGDCs from the author's series and analyze its utility. PATIENTS AND METHODS: Twelve patients, 10 male and 2 female, who were diagnosed with LTGDCs between January 2007 and December 2012, underwent endoscopic radical resection with microdissection electrodes. All cases were evaluated by enhanced CT and flexible laryngoscope before surgery. We reviewed the collected data including presentation, CT findings, surgical techniques, postoperative complication, and recurrence. RESULTS: Most adult LTGDCs presented with foreign body sensation, while one infant presented acute upper airway obstruction. All cysts abutted on the hyoid bone and were located at the midline of the posterior tongue. Endoscopic radical resection with microdissection electrodes was possible by dissecting hyoid periosteum without significant morbidity. All patients excluding 1 infant were not intubated electively overnight and went home the following morning. All patients showed no evidence of recurrence during follow-up. CONCLUSIONS: We found that the diagnosis of LTGDCs must be based on the anatomic relationship with the hyoid bone by enhanced sagittal neck CT. Endoscopic radical resection with microdissection electrodes can be recommended for reducing recurrence and morbidity by dissecting the hyoid perichondrium in the treatment of LTGDCs.

Development of a live tissue microtome: reflections of an amateur machinist.

Live circular tissue slices of nearly identical diameter and thickness can be generated from most tissues by the use of two instruments; a coring tool to cut cylindrical tissue cores which are subsequently sliced by a microtome into thin circular sections 5-8 mm in diameter and 50-300 microns thick. The sections are of very similar geometry permitting direct comparisons without normalization. Both instruments operate submerged in a cold isotonic medium that caries the cut slices outside the microtome. The slices are cut by a rapidly oscillating disposable Gillette blade mounted at an angle of 20 degrees to the vertical main axis of the tissue core. The latter is advanced against the oscillating blade by a weighted plunger pushing it against a screw adjustable limit plate that defines the desired slice thickness. Both instruments can be sterilized and slices can be obtained at a rate of approximately one every ten seconds.

Preparation and culture of precision-cut organ slices from human and animal.

1.Human and animal precision-cut organ slices are being widely used to obtain drug metabolism and toxicity profiles in vitro. These data are then used to predict what might be seen in human patients. The accuracy of this prediction and extrapolation of the findings based on human or animal in vitro systems to the findings that occur in vivo is dependent on both the quality of the tissue itself and the quality of the in vitro system. 2.The quality of human organs used in research is dependent on procurement methods, warm ischaemia time, preservation solutions, cold ischaemia time, and donor-specific factors. It is important to confirm that the organs being used are highly viable and fully functional before using them in scientific studies. 3.The optimal preparation and incubation of organ slices is also essential in maintaining slice viability and function. It is important to prepare the slices in a cold preservation solution, to prepare the slices at a correct thickness, and to incubate the slices in a system where the slice rotates in out of the oxygen atmosphere and medium. 4.Meeting the criteria outlined here will lead to successful organ slice cultures for investigating drug-induced mechanisms and organ-specific toxicity.

The "bespoke" upper eyelid blepharoplasty and brow rejuvenation.

Blepharoplasty of the upper eyelids is one of the most commonly performed procedures in aesthetic plastic surgery. In this article, we describe our approach to the patient with aging of the periorbita. At all times, the approach is tailored to the individual's needs, trying to achieve a natural result that will not in any way affect the function of the eyelid. Our current approach and techniques for upper eyelid blepharoplasty and brow lifting are described.

Novel murine model of chronic granulomatous lung inflammation elicited by carbon nanotubes.

Lung granulomas are associated with numerous conditions, including inflammatory disorders, exposure to environmental pollutants, and infection. Osteopontin is a chemotactic cytokine produced by macrophages, and is implicated in extracellular matrix remodeling. Furthermore, osteopontin is up-regulated in granulomatous disease, and osteopontin null mice exhibit reduced granuloma formation. Animal models currently used to investigate chronic lung granulomatous inflammation bear a pathological resemblance, but lack the chronic nature of human granulomatous disease. Carbon nanoparticles are generated as byproducts of combustion. Interestingly, experimental exposures to carbon nanoparticles induce pulmonary granuloma-like lesions. However, the recruited cellular populations and extracellular matrix gene expression profiles within these lesions have not been explored. Because of the rapid resolution of granulomas in current animal models, the mechanisms responsible for persistence have been elusive. To overcome the limitations of previous models, we investigated whether a model using multiwall carbon nanoparticles would resemble chronic human lung granulomatous inflammation. We hypothesized that pulmonary exposure to multiwall carbon nanoparticles would induce granulomas, elicit a macrophage and T-cell response, and mimic other granulomatous disorders with an up-regulation of osteopontin. This model demonstrates: (1) granulomatous inflammation, with macrophage and T-cell infiltration; (2) resemblance to the chronicity of human granulomas, with persistence up to 90 days; and (3) a marked elevation of osteopontin, metalloproteinases, and cell adhesion molecules in granulomatous foci isolated by laser-capture microdissection and in alveolar macrophages from bronchoalveolar lavage. The establishment of such a model provides an important platform for mechanistic studies on the persistence of granuloma.

Characterization of gastrulation-stage progenitor cells and their inhibitory crosstalk in human embryoid bodies.

Human embryoid bodies (HEBs) are cell aggregates that are produced during the course of embryonic stem cell differentiation in suspension. Mature HEBs have been shown to contain derivatives of the three embryonic germ layers. In this study, using a combination of laser capture microscopy followed by DNA microarray analysis and cell sorting, we demonstrate that early HEBs are composed of three major cell populations. These cell populations can be defined by the expression of specific cell markers, namely: (i) OCT4(+), REX1(-); (ii) NCAD(+), OCT4(-); and (iii) EPOR(+), OCT4(-). By analyzing gene expression in embryonic tissues, these cell populations could respectively be assigned to the embryonic ectoderm, mesendoderm, and extraembryonic endoderm lineages. We show that the extraembryonic endoderm, which selectively expresses platelet-derived growth factor B (PDGF-B), negatively affects the mesendoderm lineage, which selectively expresses the receptor PDGFRA. Our analysis suggests that early HEBs are spatially patterned and that cell differentiation is governed by interactions between the different cell types.

CD8 positive T cells express IL-17 in patients with chronic obstructive pulmonary disease.

BACKGROUND: Chronic obstructive pulmonary disease (COPD) is a progressive and irreversible chronic inflammatory disease of the lung. The nature of the immune reaction in COPD raises the possibility that IL-17 and related cytokines may contribute to this disorder. This study analyzed the expression of IL-17A and IL-17F as well as the phenotype of cells producing them in bronchial biopsies from COPD patients. METHODS: Bronchoscopic biopsies of the airway were obtained from 16 COPD subjects (GOLD stage 1-4) and 15 control subjects. Paraffin sections were used for the investigation of IL-17A and IL-17F expression in the airways by immunohistochemistry, and frozen sections were used for the immunofluorescence double staining of IL-17A or IL-17F paired with CD4 or CD8. In order to confirm the expression of IL-17A and IL-17F at the mRNA level, a quantitative RT-PCR was performed on the total mRNA extracted from entire section or CD8 positive cells selected by laser capture microdissection. RESULTS: IL-17F immunoreactivity was significantly higher in the bronchial biopsies of COPD patients compared to control subjects (P < 0.0001). In the submucosa, the absolute number of both IL-17A and IL-17F positive cells was higher in COPD patients (P < 0.0001). After adjusting for the total number of cells in the submucosa, we still found that more cells were positive for both IL-17A (P < 0.0001) and IL-17F (P < 0.0001) in COPD patients compared to controls. The mRNA expression of IL-17A and IL-17F in airways of COPD patients was confirmed by RT-PCR. The expression of IL-17A and IL-17F was co-localized with not only CD4 but also CD8, which was further confirmed by RT-PCR on laser capture microdissection selected CD8 positive cells. CONCLUSION: These findings support the notion that Th17 cytokines could play important roles in the pathogenesis of COPD, raising the possibility of using this mechanism as the basis for novel therapeutic approaches.

Effect of ovarian hormones on genes promoting dendritic spines in laser-captured serotonin neurons from macaques.

Dendritic spines are the elementary structural units of neuronal plasticity and the cascades that promote dendritic spine remodeling center on Rho GTPases and downstream effectors of actin dynamics. In a model of hormone replacement therapy, we sought the effect of estradiol (E) and progesterone (P) on gene expression in these cascades in laser-captured serotonin neurons from rhesus macaques with complementary DNA array analysis. Ovariectomized rhesus macaques were treated with either placebo, E or E+P through Silastic implant for 1 month before euthanasia. The midbrain was obtained, sectioned and immunostained for tryptophan hydroxylase (TPH). TPH-positive neurons were laser captured using an Arcturus Laser Dissection Microscope (PixCell II). RNA from laser-captured serotonin neurons (n=2 animals/treatment) was hybridized to Rhesus Affymetrix GeneChips. With E±P treatment, there was a significant change in 744 probe sets (analysis of variance, P<0.05), but 10,493 probe sets exhibited a twofold or greater change. Pivotal changes in pathways leading to dendritic spine proliferation and transformation included twofold or greater increases in expression of the Rho GTPases called CDC42, Rac1 and RhoA. In addition, twofold or greater increases occurred in downstream effectors of actin dynamics, including p21-activated kinase (PAK1), Rho-associated coiled-coil-containing protein kinase (ROCK), PIP5K, IRSp53, Wiskott-Aldrich syndrome protein (WASP), WASP family Verprolin-homologous protein (WAVE), MLC, cofilin, gelsolin, profilin and three subunits of actin-related protein (ARP2/3). Finally, twofold or greater decreases occurred in CRIPAK, LIMK2 and myosin light chain kinase (MLCK). The regulation of RhoA, Rac1, CDC42, ROCK, PIP5k, IRSp53, WASP, WAVE, LIMK2, CRIPAK1, MLCK, ARP2/3 subunit 3, gelsolin, profilin and cofilin was confirmed with nested quantitative reverse transcriptase-PCR on laser-captured RNA (n=3 animals/treatment). The data indicate that ovarian steroids target gene expression of the Rho GTPases and pivotal downstream proteins, that in turn would promote dendritic spine proliferation and stabilization on serotonin neurons of the dorsal raphe nucleus.

Effect of change in transporter expression on gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid-enhanced magnetic resonance imaging during hepatocarcinogenesis in rats.

BACKGROUND AND AIMS: To analyze the difference in signal intensity on gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid (Gd-EOB-DTPA)-enhanced magnetic resonance imaging (MRI) among various hepatocellular nodules during hepatocarcinogenesis as correlated with the expressions of the transporters of Gd-EOB-DTPA. METHODS: We received institutional animal review board approval prior to the commencement of all studies. Forty rats were divided into three groups. The rats in the tumor groups received N-nitrosomorpholine solution (n = 16), and rats in the cirrhosis group (thioacetamide [TAA] group) received thioacetamide solution (n = 12). As a control, the remaining 12 rats were fed normal water. Each group was divided into two sub-groups: Group 1 for Gd-EOB-DTPA-enhanced MRI (0.025 mmol Gd/kg, n =7) and Group 2 for reverse transcription-polymerase chain reaction to compare transporter (oatp1 and mrp2) expressions (n = 5 for control and TAA groups, n = 9 for tumor groups). RESULTS: Signal enhancement of tumors decreased according to the progress of hepatocarcinogenesis. Although the relative enhancement of each tumor group was significantly lower than that of the control group (P < 0.01), and there was no significant difference between TAA, hyperplastic nodules (HPN), and HCC(well) groups. The relative enhancement of the HCC(mod) group was significantly lower than the other groups (P < 0.01). The oatp1 expression of HPN tended to be higher than those of HCC(well) and HCC(mod). The mrp2 expression of TAA was significantly higher than those of HCC(well), HCC(mod), HPN and control (P < 0.01). The mrp2 expression of HPN tended to be higher than those of HCC(well ) and HCC(mod). CONCLUSION: It was suggested that the signal enhancement on Gd-EOB-DTPA-enhanced MRI would correlate with the transporter expression in various hepatocellular nodules during hepatocarcinogenesis.

Sub-surface, micrometer-scale incisions produced in rodent cortex using tightly-focused femtosecond laser pulses.

BACKGROUND AND OBJECTIVE: Techniques that allow targeted, micrometer-scale disruption in the depths of biological tissue, without affecting overlying structures or causing significant collateral damage, could potentially lead to new surgical procedures. We describe an optical technique to make sub-surface incisions in in vivo rodent brain and characterize the relationship between the cut width and maximum depth of these optical transections as a function of laser energy. MATERIALS AND METHODS: To produce cuts, high intensity, femtosecond laser pulses were tightly focused into and translated within the cortex, through a craniotomy, in anesthetized rodents. Imaging of stained brain slices was used to characterize cut width and maximum cutting depth. RESULTS: Cut width decreased exponentially as a function of depth and increased as the cube root of laser energy, but showed about 50% variation at fixed depth and laser energy. For example, at a laser energy of 13 µJ, cut width decreased from 158 ± 43.1 µm (mean ± standard deviation) to 56 ± 33 µm over depths of approximately 200-800 µm, respectively. Maximal cut depth increased logarithmically with laser energy, with cut depths of up to 1 mm achieved with 13 µJ pulses. We further showcased this technique by selectively cutting sub-surface cortical dendrites in a live, anesthetized transgenic mouse. CONCLUSIONS: Femtosecond laser pulses provide the novel capacity for precise, sub-surface, cellular-scale cuts for surgical applications in optically scattering tissues.

A new microsurgical instrument--a suction tube combined with a microdissector.

A microsurgical suction tube with an attached ball probe has been developed. It functions as a microdissector when the ball probe is in its extended position, creating a larger working field than an ordinary sucker. When the ball probe is in the repose position, it does not interfere with the suction capacity, and the suction tube serves as a regular sucker. By adding the properties of the microdissector to the suction tube, dissection of exquisitely fine and subtle structures, including arachnoidal membranes, is facilitated. The ball probe is easily dismantled from the suction tube and the whole instrument conveniently cleaned.