Histological Light Microscopy Research Articles

β-Glucan Regulates Lipopolysaccharide Induced Genotoxic Damage to The Liver through The Induction of BRCA1 Protein Expression.

The present study aims to investigate the role of breast cancer-susceptibility gene 1 (BRCA1) protein in the β-Glucan (βG) molecule mediated regulation of lipopolysaccharide (LPS)-induced liver genotoxicity. In this experimental study, totally, 32 male Swiss Albino mice were randomly divided into 4 equal groups: control (C), LPS-administered (LPS), βG-administered (βG) and βG-pre-administered/LPS-administered (βG+LPS). The βG was injected at the dose of 150 mg/kg/day intraperitoneally (i.p.) for 3 days. A single dose of 4 mg/ kg (i.p.) LPS was administered 24 hours after the last βG injection. BRCA1 expression was determined by western blot analysis and confirmed by quantitative immunofluorescence. Proliferating cell nuclear antigen (PCNA), nuclear factor erythroid 2-related factor (Nrf2) and 8-OHdG protein levels were also determined by the immunofluorescence analysis. The alkaline comet assay was performed. superoxide dismutase (SOD), catalase (CAT) and membrane lipid peroxidation were biochemically measured, and light microscopic histology was evaluated. The BRCA1 expression level was significantly decreased in the LPS group. However, in the βG+LPS group, expression of BRCA1 protein was over 2 folds higher than the control. After the LPS induction, the DNA strand breaks, oxidative DNA lesions and abnormal proliferation of the liver cells were almost entirely suppressed in βG preadministrated animals, indicating the BRCA1 mediated ubiquitination of PCNA and activation of the DNA damage repair pathways. Activation of Nrf2 in the βG+LPS group resulted in an increase in the levels of Nrf2 pathway dependent antioxidant enzymes SOD and CAT, prevented the peroxidation of membrane lipids and maintained the histological architecture of the liver. The results manifested that the βG is a strong inducer of the BRCA1 protein expression in the LPSinduced hepatic stress and the protein constitutes the key component of a βG mediated liver protection against an LPS-induced genotoxic and pathological damage.

Mid-Term Outcomes of Novel Covered Stent with Biodegradable Membrane in Porcine Coronary Artery Perforation.

Currently, commercially covered stents are the main treatment for coronary artery perforation (CAP), but without satisfied late-term outcomes when compared to drug-eluting stents (DES). This study seeks to report a new covered stent to treat porcine CAP, which is manufactured with DES and a biodegradable membrane fabricated by poly-L-lactic acid (PLLA) polymer. Experimental swines experienced CAP in proximal-middle of right coronary artery (RCA) by non-compliant balloon burst, and covered stent was deployed in breach segment. Meanwhile, coronary angiography (CAG), optical coherence tomography (OCT), histological light microscopy and scan electron microscopy were performed to characterize the performance of covered stent. Seven swines were used for this study. Two swines were euthanasia at 14 days and 28 days after procedure, respectively. The remaining 5 kept alive until sacrifice at six months. CAG at six months showed total occlusion at the stented segment of RCA in all swines. The interventional revascularization of occlusion lesion was instituted in two swines. After recanalizing occlusion lesion, OCT examination visualized diffuse heterogeneous fibrous plaques, as well as organized thrombosis, lipid deposits and several neoatherosclerosis in the occluded segment. Serial histopathologic and electron microscopies at 14 days, 28 days and six months revealed gradual occlusive vessel lumen with diffuse heterogeneous fibroplasia, smooth muscle proliferation, inflammation response and local neoatherosclerosis, moreover with identification of PLLA polymer membrane degradability. The new covered stent with biodegradable membrane could seal urgent coronary breach and prevent experimental swines death, but with all stent occlusion in mid-term (six months) follow-up, which might be attributed to diffuse heterogeneous fibroplasia, smooth muscle proliferation, inflammation response and local neoatherosclerosis with the degradation of PLLA membrane.

Giving volume to the elephant in the imaging room.

Rudolf Virchow, the founder of cellular pathology, held that even when physical or chemical investigations yield the laws of physiology or medicine, the anatomist can still proudly state: This is the structure in which the law becomes manifest. In his words, "physiology presupposes anatomy." Pathological anatomy studies, at usual microstructural scales (approximately 1-100 μm), via light microscopic 2D histology, provided many insights into structure-function relationships of health and disease. For example, such studies established the progression of granulomas, bronchial erosions, microcavities, anddestructive lung disease in tuberculosis. While histologic studies remain the cornerstone of such efforts, the advent of nano or micro-X-ray computed tomography (n/μCT) has now made it additionally possible to obtain 3D visualizations of soft and hard tissues, while preserving the tissue for additional investigations. This has applications for old as well as new diseases (Katsamenis etal,2019; Tanabe & Hirai,2021).

Ultrastructural and immunohistochemical characteristics of the olfactory organ cardinal tetra, Paracheirodon axelrodi (Characiformes: Characidae).

The cardinal tetra Paracheirodon axelrodibelongs to the family Characidae, an economically important and morphologically diverse family of fishes. Information on the olfactory system of this species is scattered and scarce. Among teleost fishes, differences exist in the shape, number, and arrangement of the olfactory lamellae, in the distribution of the sensory and nonsensory epithelium, as well as in the abundance of various receptor cell types. Here, an anatomical and morphological description of the olfactory system was carried out using light microscopic histology, immunohistochemistry, scanning electron microscopy, and transmission electron microscopy. P. axelrodi is a ditremous and isosmat species. It has an arrow-shaped olfactory rosette arrangement. The olfactory epithelium is covering the 12-14 lamellae of the olfactory rosette and, using scanning electron microscopy, we observed that the apical surface of the olfactory epithelium carries a dense layer of mucus. Based on the histological, immunohistochemical, and ultrastructural descriptions, all characteristic sensory and nonsensory cell types of the olfactory epithelium of teleost fish were identified. Three types of olfactory receptor neurons were identified: ciliated, microvilli, and crypt cells. The distribution of sensory and nonsensory cell types is like that described in Aphyocharax anisitsi, another species of the Characidae family. A. anisitsi inhabits slow-flowing water bodies with high-density vegetation such as P. axelrodi.

Efficacy and Biosafety of a New Bioresorbable Vascular Scaffold Covered with Biodegradable Film in Rabbits: An In Vivo Study.

We developed a new fully bioresorbable vascular scaffold covered with biodegradable poly-L-lactic acid film (Firesorb-C) for coronary artery perforation. Our vitro tests have demonstrated that Firesorb-C was technically feasible but its biosafety and efficacy warranted further validation in vivo. The aim of this study was to evaluate the biosafety and efficacy of Firesorb-C in rabbits. Firesorb-C was deployed at the zone from the abdominal aorta to the right iliac artery in five rabbits. Angiography was conducted for evaluation of the immediate efficacy and 6-month biosafety and biodegradability of the Firesorb-C. Meanwhile, optical coherence tomography (OCT), histological light microscopy (HLM) and scan electron microscopy (SEM) were performed to evaluate the biosafety. All Firesorb-C applications were successfully implanted without procedure-related complications. In all treated rabbits, angiography showed that the Firesorb-C had completely sealed the opening of the left iliac artery without blood flow in its branches but with full patency of the right iliac artery immediately post-procedurally, while the covered membrane of Firesorb-C had been degraded and blood flow was restored in the left iliac artery and its branches at 6 months. OCT also found that the occluded left iliac artery had been reopened and the stented segment was almost fully endothelialized without in-stent restenosis at 6 months, meanwhile HLM and SEM confirmed comparable results. Firesorb-C is associated with excellent efficacy, biosafety and biodegradability in rabbits. It shows promise as a replacement for conventional covered stents for treatment of coronary artery perforation or for use in other clinical situations.

SUN-434 WHEN PROPHYLAXIS BECAME THE PROBLEM; AN INTERESTING CASE OF GRANULOMATOUS NEPHRITIS IN A RENAL TRANSPLANT PATIENT WHO WAS ON ROUTINE ANTIBIOTIC PROPHYLAXIS

A 41year old male patient received a Donation after brain death (DBD) kidney transplant from a 27-year-old female patient with a traumatic head injury. The donor had normal kidney function with an estimated glomerular filtration rate (eGFR) greater than 90 ml/min/1.732 m2 with no significant past medical history. The HLA mismatch was 1:1:1 and a cold ischaemic time of 13 hours 42 minutes. His primary renal disease was hypertensive ischaemic nephropathy, which was proven by renal biopsy in year 2016. Patient was on haemodialysis for 3 months via a left brachiocephalic fistula and had a urine output of 1000 to 1200 milliliters (mls) per day. Induction for renal transplant was with Basiliximab and Methylprednisolone. Maintenance immunosuppression therapy consisted of Prednisolone, Tacrolimus and Mycophenolate initiated from the day of surgery. Pneumocystis Carinii Pneumonia (PCP) prophylaxis was provided with co-trimoxazole. His surgery was uncomplicated and no immediate post-operative complications were reported. Immediately following surgery patient had a urine output of 90-100 mls/hour. On the first post-operative day this increased to 200 mls/hour. Despite having a good urine output his eGFR did not improve. Ultrasounds suggested good renal perfusion with no evidence of obstruction. His Tacrolimus levels were within acceptable limits (8-10) and there were no signs of infection. A decision to do a transplant kidney biopsy was made on the fifth day following a multidisciplinary team meeting. Patient's clinical notes and local renal data software (Vital Data) were used to get the details and information. Histological light microscopy images were requested from the Histopathology department.View Large Image Figure ViewerDownload Hi-res image Download (PPT) His transplant kidney biopsy showed florid granulomatous interstitial nephritis with no evidence of infection, rejection or Calcineurin Inhibitor (CNI) toxicity Figure 1. Differential diagnosis were fungal infections, sarcoidosis, adenovirus and tuberculosis, however all results were negative. The status of sister kidney (other kidney from the same donor) was investigated and showed that the recipient was discharged with an eGFR greater than 60 on the seventh day post-transplant. After excluding infection, rejection and any granulomatous disease in the sister kidney, drugs were thought to be a potential causative agent. Co-trimoxazole seemed most likely but there was very limited evidence in support of this. The patients’ Co-Trimoxazole was stopped and Dapsone was initiated for PCP prophylaxis. High dose oral prednisolone 60 mg was also initiated keeping in mind the severe inflammation. His eGFR rose from 7-to 20 ml/min/1.732 m2 in 7 days. Since then it has continually improved and the eGFR is now 46. Demonstrated by Figure 2. Our case report i suggests that in patients with early renal allograft dysfunction clinicians should be mindful about the possibility of AIN secondary to prophylactic antibiotics like Co-Trimoxazole. This case was discussed in American Society of Nephrology at San Diego 2018 in a talk on renal biopsy and clinical correlations. Neither the speakers and nor the audience agreed to have seen a case of granulomatous interstitial nephritis secondary to Co-trimoxazole and suggested to publish this case.

Revealing the Microscopic Structure of Human Renal Cell Carcinoma in Three Dimensions.

For fully characterizing renal cell carcinoma (RCC), information about the 3D tissue microstructure is essential. Histopathology, which represents the current diagnostic gold standard, is destructive and only provides 2D information. 3D X-ray histology endeavors to overcome these limitations by generating 3D data. In a laboratory environment, most techniques struggle with limited resolution and the weak X-ray attenuation contrast of soft tissue. We recently developed a laboratory-based method combining nanoscopic X-ray CT with a cytoplasm-specific X-ray stain. Here, we present the application of this method to human RCC biopsies. The NanoCT slices enable pathological characterization of crucial structures by reproducing tissue morphology with a similar detail level as corresponding histological light microscopy images. Beyond that, our data offer deeper insights into the 3D configuration of the tumor. By demonstrating the compatibility of the X-ray stain with standard pathological stains, we highlight the feasibility of integrating staining based NanoCT into the pathological routine.

3D Imaging of Soft-Tissue Samples using an X-ray Specific Staining Method and Nanoscopic Computed Tomography.

We demonstrate a laboratory-based method combining X-ray microCT and nanoCT with a specific X-ray stain, which targets the cell cytoplasm. The described protocol is easy to apply, fast and suitable for larger soft-tissue samples. The presented methodology enables the characterization of crucial tissue structures in three dimensions and is demonstrated on a whole mouse kidney. The multiscale approach allows to image the entire mouse kidney and supports the selection of further volumes of interest, which are acquired with higher resolutions ranging into the nanometer range. Thereby, soft-tissue morphology with a similar detail level as the corresponding histological light microscopy images is reproduced. Deeper insights into the 3D configuration of tissue structures are achieved without impeding further investigations through histological methods.

Impact of HIV/simian immunodeficiency virus infection and viral proteins on adipose tissue fibrosis and adipogenesis

HIV-infected patients receiving antiretroviral treatment (ART) often present adipose tissue accumulation and/or redistribution. adipose tissue has been shown to be an HIV/SIV reservoir and viral proteins as Tat or Nef can be released by infected immune cells and exert a bystander effect on adipocytes or precursors. Our aim was to demonstrate that SIV/HIV infection per se could alter adipose tissue structure and/or function. Morphological and functional alterations of subcutaneous (SCAT) and visceral adipose tissue (VAT) were studied in SIV-infected macaques and HIV-infected ART-controlled patients. To analyze the effect of Tat or Nef, we used human adipose stem cells (ASCs) issued from healthy donors, and analyzed adipogenesis and extracellular matrix component production using two dimensional (2D) and three-dimensional (3D) culture models. Adipocyte size and index of fibrosis were determined on Sirius red-stained adipose tissue samples. Proliferating and adipocyte 2D-differentiating or 3D-differentiating ASCs were treated chronically with Tat or Nef. mRNA, protein expression and secretion were examined by RT-PCR, western-blot and ELISA. SCAT and VAT from SIV-infected macaques displayed small adipocytes, decreased adipogenesis and severe fibrosis with collagen deposition. SCAT and VAT from HIV-infected ART-controlled patients presented similar alterations. In vitro, Tat and/or Nef induced a profibrotic phenotype in undifferentiated ASCs and altered adipogenesis and collagen production in adipocyte-differentiating ASCs. We demonstrate here a specific role for HIV/SIV infection per se on adipose tissue fibrosis and adipogenesis, probably through the release of viral proteins, which could be involved in adipose tissue dysfunction contributing to cardiometabolic alterations of HIV-infected individuals.

Light-Induced Length Shrinkage of Rod Photoreceptor Outer Segments.

PurposeThis study was designed to verify light-induced outer segment (OS) length shrinkage of rod photoreceptors and to characterize its anatomic source at disc-level resolution.MethodsFrog (Rana pipiens) retinas were used for this study. Time-lapse light microscopy of freshly isolated OSs was employed to test transient rod OS changes at 10 ms temporal resolution. Histological light microscopy of dark- and light-adapted retinas was used to confirm light-induced rod OS length changes; and transmission electron microscopy (TEM) was used to quantify light-driven structural perturbation of rod OSs at disc level resolution.ResultsTime-lapse light microscopy images verified transient length shrinking responses in freshly isolated rod OSs. Histological light microscopy images confirmed reduced rod OS lengths in light-adapted retinas, compared to that of dark-adapted retinas. TEM images disclosed shortened inter-disc distances in light-adapted retinas compared to dark-adapted retinas.ConclusionsLight-induced rod OS length shrinkage was confirmed using time-lapse light microscopy of isolated rod OSs and histological light microscopy of dark- and light-adapted retinas. TEM revealed that the rod OS length shrinkage was correlated to the light-driven decrease of the space between individual discs, not the disc thickness itself.Translational RelevanceLight-induced transient rod response promises a noninvasive biomarker for early diagnosis of age-related macular degeneration and retinitis pigmentosa, in which the rod photoreceptors are known to be more vulnerable than cone photoreceptors.

Achilles tendinosis does not always precede Achilles tendon rupture.

Degenerative change is a typical histologic finding of Achilles tendinosis and is thought to be a factor associated with Achilles tendon rupture; however, this relationship remains controversial. Therefore, the aim of this study was to review the histological findings of ruptured Achilles tendons and analyze demographics and injury patterns. Retrospective analysis was performed for all patients who underwent Achilles tendon repair for acute Achilles tendon rupture at our institution between 2008 and 2015. The presence of Achilles tendinosis was determined by light microscopic histology of ruptured Achilles tendons. Patients were grouped according to the presence of Achilles tendinosis and patient demographics, sports activities, and clinical outcomes were compared. Ankle activity score was used to evaluate the level of sports activity and Achilles tendon total rupture score (ATRS) was used to evaluate clinical outcomes. A total of 152 Achilles tendon ruptures were included: 112 (77%) showed Achilles tendinosis at a ruptured Achilles tendon on histology and 40 (23%) did not. Patients who had no Achilles tendinosis prior to rupture had a lower ankle activity score (P < 0.05) and higher incidence of non-sports related injury (P < 0.05). ATRS was not significantly different between the groups at final follow-up (P = n.s.). In contrast to previous reports, Achilles tendon rupture can occur without prior Achilles tendinosis, especially in non-sports-related injuries and in patients with low sports activity. Although the direct clinical applications of these results are limited, the findings of this study can improve our understanding of the etiology of Achilles tendon rupture. Prognostic, Level III.

Descriptive analysis of glomerulonephritis by histological type and their progression among adults in a tertiary care center in Sri Lanka.

Prevalence of different glomerulonephritides and their clinical course vary geographically. Our objectives are to assess the prevalence of different histological types of glomerulonephritis (GN) based on the light microscopic histology and to assess their progression according to histological type. A retrospective cross-sectional study was carried out among adult patients (>18 years) with a histological diagnosis of GN at the University Professorial Unit over a period of six months. Information including demographic data, renal biopsy findings, and progression of the disease through serum creatinine (SCr) level were collected through existing clinic records of consenting patients. Data were analyzed by Statistical Package for the Social Sciences. There were 109 patients (females = 90) with a mean age of 40.32 ± 15.24 years. The most common histological type was focal segmental glomerulosclerosis (FSGS) in 27 (24.8%) followed by minimal change disease in 25 (22.9%), mesangioproliferative glomerulonephritis (MesPGN) in 18 (16.5%), membranoproliferative glomerulonephritis in six (5.5%), membranous glomerulonephritis in three patients (2.8%), and crescentic GN in one patient (0.9%). There was a statistically significant rise in SCr level at seven years from the initial presentation in the histological types; FSGS [P = 0.04; 95% confidence interval (CI) = 0.06-1.0] and MesPGN (P = 0.03; 95% CI = 0.3-0.9). Focal segmental glomerulosclerosis was the most common histology type in the population studied. There was a statistically significant progression of FSGS and MesPGN.

A mouse dry eye model induced by topical administration of the air pollutant particulate matter 10

AimTo introduce a novel dry eye mouse model induced by topical administration of the air pollutant particulate matter 10 (PM10). MethodA total of 60 male BALB/c mice were used in this study and divided into two groups: group A (PBS eye drops, n=30) and group B (PM10 eye drop group, n=30). Each treatment was dosed four times a day, every time 50ul with the concentration of 5mg/ml PM10, for 14 consecutive days in the right eye. The clinical manifestations of dry eye were measured before therapy and 4, 7 and 14days post-treatment respectively, which included the tear volume, tear break-up (BUT) time, corneal fluorescein staining, rose bengal staining, Lissamine Green staining and inflammatory index. Eye samples were collected on D14 and examined by histologic light microscopy, transmission electron microscopy (TEM) and scanning electron microscopy (SEM), corneal cytokeration 10 (K10) immunnostaining, and tumor necrosis factor-α (TNF-α), NF-κB-p65 and NF-κB Western Blot analysis. ResultsAt 0d, 7d and 14d, there were no statistical changes in tear volume, BUT after treatment (P>0.05) with PBS in group A. In group B, all items showed statistical differences at each time point (P<0.05). At 14d after therapy, the fluorescein staining score of group B was higher than group A (P<0.05). The score of rose bengal staining and Lissamine Green staining in group B was also higher than that in group A (P<0.05). The number of mean layers of corneal epithelial cells in the group A was significantly lower than that in the group B (P<0.05). TEM and SEM revealed that the number of corneal epithelial microvilli were drastically reduced in group B. The number of corneal chondriosome/desmosomes was also reduced in group B by TEM. PM10 induced apoptosis in the superficial and basal corneal epithelium, and leaded to abnormal differentiation and proliferation of the ocular surface with higher expression levels of K10 and reduced number of goblet cells in the conjunctival fornix in group B. PM10 significantly increased the levels of TNF-α, NF-κB-p65 and NF-κB in the cornea. ConclusionPM10 can damage the tear film function and cause the destruction of the structural organization of ocular surface in mice. Topical administration of PM10 in mice induces ocular surface changes that are similar to those of dry eye in humans, representing a novel model of DES.

A microstructural study of the pleon-holding mechanism in Carcinus maenas (Decapoda, Brachyura, Portunoidea, Carcinidae) of different sizes.

Within the Brachyura there are a variety of specialized holding mechanisms, which facilitate the close attachment of the highly reduced pleon underneath the cephalothorax. The most common mechanism in eubrachyurans, known as the press-button, consists of a sternal protrusion and a corresponding pleonal socket. Reports on the microstructural properties of the surface of these holding structures are scarce and patchy. In this study, the European Green Crab Carcinus maenas, is used as model to describe the microstructure of a typical press-button mechanism with the use of scanning electron microscopy and light microscopic histology. A highly tuberculate cuticle and an apical ridge on the sternal knob are found in juveniles of both sexes. The microstructures are lost in adult males. In adult females, the holding structures themselves are reduced, but never completely lost. These findings show that C. maenas does not undergo a single "final puberty moult," after which all juvenile characteristics are lost, as previously assumed. Further comparison of the morphology of juveniles to another species indicates a close resemblance of the holding structures at this stage. Therefore, the use of the microstructure of the pleon-holding mechanism for phylogenetic analysis is restricted to adult specimens.

Reproductive Toxicity to Male Mice of Nose Only Exposure to Water‐ Pipe Smoke

Data on the possible adverse reproductive effects of water pipe smoking (WPS) are lacking. Here, we assessed the effects of exposure to WPS in mice. The duration of the session was 30 min/day for one month. Control mice were exposed to air. Twenty- four h after the last exposure, mice were killed and the testes and plasma removed. Testicular protein, alkaline phosphatase, several indices of oxidative damage and Vascular Endothelial Growth Factor Receptor 2 (VEGFR2) were quantified. The plasma concentrations of leptin, and reproductive hormones were also measured. Histological analysis of testes and lungs was also conducted. WPS caused statistically significant decreases in the plasma concentrations of leptin, testosterone, and LH, and in the concentrations of total protein and the antioxidant indices measured. A statistically non - significant decrease in VEGFR2 protein in the WPS - exposed mice was also found. The body and testicular weights of mice exposed to WPS , as well as testicular alkaline phosphatase activity and light microscopic histology, and plasma estrogen concentration were all not significantly affected by WPS. Further studies on the functional implications of these findings in mice exposed to WPS for longer duration are warranted.

Reproductive Toxicity to Male Mice of Nose Only Exposure to Water- Pipe Smoke

Background/Aims: Water-pipe smoking (WPS) is popular in the Middle East and is starting to gain popularity in several Western countries as well. It is widely and erroneously perceived to be less harmful than other forms of tobacco use. The reproductive adverse effects of cigarette smoking have been studied before with conflicting results, but data on the possible adverse reproductive effects of WPS are lacking. Here, we assessed the effects of nose-only exposure to mainstream WPS generated by commercially available honey-flavored "moasel" tobacco in mice. Methods: The duration of the session was 30 min/day for one month. Control mice were exposed to air. Twenty- four h after the last exposure, mice were killed and the testes and plasma removed for analysis. In testicular homogenates total protein, alkaline phosphatase activity, several indices of oxidative damage and Vascular Endothelial Growth Factor Receptor 2 (VEGFR2) were quantified. The plasma concentrations of leptin, testosterone, estrogen and luteinizing hormone (LH) were also measured. Histological analysis of testes and lungs was also conducted. Results: WPS caused statistically significant decreases in the plasma concentrations of leptin, testosterone, and LH, and in the concentrations of total protein and the antioxidant indices measured. A statistically non - significant decrease in VEGFR2 protein in the WPS - exposed mice compared to the control mice was also found. The body and testicular weights of mice exposed to WPS, as well as their testicular alkaline phosphatase activity and light microscopic histology, and plasma estrogen concentration were all not significantly affected by WPS. Conclusion: Further studies on the functional implications of these findings in mice exposed to WPS for longer durations are warranted.

A novel perfusion-based method for cochlear implant electrode insertion

A cochlear implant (CI) restores partial hearing to profoundly deaf individuals. CI electrodes are inserted manually in the cochlea and surgeons rely on tactile feedback from the implant to determine when to stop the insertion. This manual insertion method results in a large degree of variability in surgical outcomes and intra-cochlear trauma. Additionally, implants often span only the basal turn. In the present study we report on the development of a new method to assist CI electrode insertion. The design objectives are (1) an automated and standardized insertion technique across patients with (2) more apical insertion than is possible by the contemporary methods, while (3) minimizing insertion trauma. The method relies on a viscous fluid flow through the cochlea to carry the electrode array with it. A small cochleostomy (∼100-150 um in diameter) is made in scala vestibuli (SV) and the round window (RW) membrane is opened. A flow of diluted Sodium Hyaluronate (also known as Hyaluronic Acid, (HA)) is set up from the RW to the SV opening using a perfusion pump that sets up a unidirectional flow. Once the flow is established an implant is dropped into the ongoing flow. Here we present a proof-of-concept study where we used this technique to insert silicone implants all the way to the cochlear apex in rats and gerbils. In light-microscopic histology, the implantation occurred without cochlear trauma. To further assess the ototoxicity of the HA perfusion, we measured compound action potential (CAP) thresholds following the perfusion of HA, and found that the CAP thresholds were substantially elevated. Thus, at this point the method is promising, and requires further development to become clinically viable.

Disruption of vitellogenesis and spermatogenesis by triclabendazole (TCBZ) in a TCBZ-resistant isolate of Fasciola hepatica following incubation in vitro with a P-glycoprotein inhibitor.

A study has been carried out to investigate whether the action of triclabendazole (TCBZ) against Fasciola hepatica is altered by inhibition of P-glycoprotein (Pgp)-linked drug efflux pumps. The Sligo TCBZ-resistant fluke isolate was used for these experiments and the Pgp inhibitor selected was R(+)-verapamil [R(+)-VPL]. In the first experiment, flukes were initially incubated for 2 h in R(+)-VPL (100 μ m), then incubated in R(+)-VPL+triclabendazole sulphoxide (TCBZ.SO) (50 μg mL-1, or 133·1 μ m) until flukes ceased movement (at 9 h post-treatment). In a second experiment, flukes were incubated in TCBZ.SO alone and removed from the incubation medium following cessation of motility (after 15 h). In the third experiment, flukes were incubated for 24 h in R(+)-VPL on its own. Changes to the testis tubules and vitelline follicles following drug treatment and following Pgp inhibition were assessed by means of light microscope histology and transmission electron microscopy. Incubation of the Sligo isolate in either R(+)-VPL or TCBZ.SO on their own had a limited impact on the morphology of the two tissues. Greater disruption was observed when the drugs were combined, in terms of the block in development of the spermatogenic and vitelline cells and the apoptotic breakdown of the remaining cells. Sperm formation was severely affected and abnormal. Large spaces appeared in the vitelline follicles and synthesis of shell protein was disrupted. The results of this study support the concept of altered drug efflux in TCBZ-resistant flukes and indicate that drug transporters may play a role in the development of drug resistance.

Increased action of triclabendazole (TCBZ) in vitro against a TCBZ-resistant isolate of Fasciola hepatica following its co-incubation with the P-glycoprotein inhibitor, R(+)-verapamil

A study has been carried out to investigate whether the action of triclabendazole (TCBZ) against Fasciola hepatica is altered by inhibition of P-glycoprotein (Pgp)-linked drug efflux pumps. The Sligo TCBZ-resistant fluke isolate was used for these experiments and the Pgp inhibitor selected was R(+)-verapamil [R(+)-VPL]. In the first experiment, flukes were initially incubated for 2h in R(+)-VPL (1×10−4 M), then incubated in R(+)-VPL + triclabendazole sulphoxide (TCBZ.SO) (50μg/ml) until flukes ceased movement (at 9h post-treatment). In a second experiment, flukes were incubated in TCBZ.SO alone and removed from the incubation medium following cessation of motility (after 15h). In the third experiment, flukes were incubated for 24h in R(+)-VPL on its own. Changes to the tegumental system and gut following drug treatment and following Pgp inhibition were assessed by means of light microscope histology and transmission electron microscopy. Incubation of the Sligo isolate in either R(+)-VPL or TCBZ.SO on their own had a limited impact on the tegumental syncytium and tegumental cells; the changes were consistent with a stress response by the fluke to drug action. Greater disruption was observed when the drugs were combined, in terms of the vacuolation and sloughing of the syncytium, spine disruption and the cessation of secretory activity in, and degradation of, the tegumental cells. In the gut, treatment with R(+)-VPL on its own did not lead to any cellular changes. Some limited changes to the mitochondria and the granular endoplasmic reticulum were observed after incubation in TCBZ.SO alone, together with reduced secretory activity and evidence of autophagy. However, these changes were far more pronounced in combination-treated flukes. The results of this study support the concept of altered drug efflux in TCBZ-resistant flukes and indicate that drug transporters may play a role in the development of drug resistance.

Some physiological and histological aspects of the gastrointestinal tract in a mouse model of chronic renal failure

IntroductionIt has been reported that mice with 5/6 nephrectomy- induced chronic renal failure (CRF) have reduced gastrointestinal transit (GIT) and increased fecal moisture content (FMC). We have recently shown that feeding adenine (0.2%, w/w) to mice can be used as a model of CRF. Here, we investigated the possible effects of adenine-induced CRF on several in vivo and in vitro aspects of GIT physiology and histology of the stomach, duodenum, ileum and colon in mice. MethodsThe effects of CRF induced by feeding adenine (0.2%, w/w for 2 or 4weeks) on the gastric emptying index (GEI), GIT, FMC and bead expulsion test (BET) were investigated. GIT was measured by the charcoal meal test and GEI by the difference between full and empty stomach weights. Fresh and dried feces were weighed to calculate the FMC. Renal function was assessed histologically, and biochemically in plasma and urine. The light microscopic histology of the different parts of the gut, as well as the in vitro contractility of the isolated ileum was also assessed. ResultsFeeding adenine for 2 or 4weeks resulted in CRF. The BET was significantly increased in mice given adenine for 2 but not 4weeks, while the GEI was significantly increased in mice treated with adenine for 4 but not 2weeks. No significant differences between control and adenine-treated mice were found in GIT, FMC or the histology of the different parts of the gut. Acetylcholine-induced contractions of the ileum of adenine-treated rats were not significantly different from those of the controls. DiscussionFeeding adenine for either 2 or 4weeks resulted in CRF, but it would appear that this model produces effects on the gastrointestinal tract that are milder than those reported before in animal models with 5/6 nephrectomy-induced-CRF.