Xylene-free method for histological preparation: a multicentre evaluation

Epicutaneous Application of Mannan Induces Psoriasis-like Inflammation in an Inbred Mouse Strain

Mannan from yeast induces psoriasis-like inflammation in the skin of inbred mouse strains. Limitations of available models led us to develop a new psoriasis model with a rapid disease onset, severe disease course, short duration, and a simple and easy-to-induce protocol with much more practically convenient features and cost-benefits. Mannan-induced skin inflammation (MISI) is more severe than the classical imiquimod (IMQ)-induced skin inflammation (IISI), with characteristic features resembling human plaque psoriasis but with relatively fewer toxicity issues. Epicutaneous application of mannan (5 mg) in incomplete Freund's adjuvant or Vaseline induces severe psoriasis in BALB/c female mice. Psoriasis area and severity index (PASI) and histological evaluation of the skin could help assess the disease development. MISI mimics natural environmental factors affecting the skin relatively more closely than IISI. This disease model can be used to dissect inflammatory pathways in the skin, identify genetic and environmental factors affecting psoriasis, and test potential pharmacological agents or new combinations of available drugs for treatment before designing clinical trials. Key features • S. cerevisiae mannan induces psoriasis-like skin inflammation (MISI) when applied on the skin of inbred mice. • The MISI model has a rapid onset, severe disease, short duration, and simple and easy-to-induce protocol. • MISI is more severe than imiquimod-induced skin inflammation (IISI). • Female mice had a more severe disease than males in the MISI model, thereby allowing the study of sex-dependent disease mechanisms. • The MISI model identifies skin inflammatory pathways and genetic/environmental factors affecting psoriasis. • The MISI model can be used as a drug testing platform for potential pharmaceuticals to develop new therapeutics for psoriasis patients. • The MISI model can be used to explore the relative contribution of different pattern recognition receptors in the development and severity of psoriasis.

Biofriendly Substitutes for Xylene in Deparaffinization

Background

Xylene is an aromatic hydrocarbon that is routinely used in histopathological laboratories. It is biohazardous and produces many toxic effects like carcinogenesis. A safer substitute for xylene is necessary to minimize its usage.

Aim

The aim of this study was to evaluate the effectiveness of 1.7% dishwashing solution, 95% lemon water, and 100% coconut oil when compared to xylene as a deparaffinizing agent during hematoxylin and eosin (H&E) staining.

Materials and Methods

Fifteen paraffin-embedded tissue blocks were selected. Four sections were made from each block. One section was stained with conventional H&E method using xylene (group A) as deparaffinizing agent and other three sections were stained with xylene-free H&E method using 1.7% dishwashing solution (group B), 95% lemon water (group C), and 100% coconut oil (group D), respectively. Slides were scored blindly by a single pathologist considering the parameters such as nuclear and cytoplasmic staining; uniformity, clarity, and crispness of staining; and presence or absence of wax retention.

Results

Adequate nuclear staining was noted in 100% of sections of groups A, B, C, and D (P < 0.001), whereas adequate cytoplasmic staining was noted in 93.33% each in groups A, C, and D when compared with 100% in group B (P > 0.05). Uniform staining was present in 80% of groups A and B and in 73.33% of groups C and D (P > 0.05). Clarity of staining was present in 86.66% of groups A and B and in 80% of groups C and D (P > 0.05), whereas crispness of staining was seen in 73.33% of groups A and D, 86.66% of group B, and 80% of group C (P > 0.05). Wax retention was noted in 20% of groups A and B, and 26.66% of groups C and D (P > 0.05). Adequate staining for diagnosis was noted in 100% of group A sections followed by 93.33% in group B, 86.66% in group C, and 80% in group D as compared with 90% in group B (P > 0.05).

Conclusion

Dishwashing solution, lemon water, and coconut oil can be used as safer and cost-effective substitutes to xylene for deparaffinization in H&E staining procedure.

NanoBiT System and Hydrofurimazine for Optimized Detection of Viral Infection in Mice-A Novel in Vivo Imaging Platform

Reporter genes are used to visualize intracellular biological phenomena, including viral infection. Here we demonstrate bioluminescent imaging of viral infection using the NanoBiT system in combination with intraperitoneal injection of a furimazine analogue, hydrofurimazine. This recently developed substrate has enhanced aqueous solubility allowing delivery of higher doses for in vivo imaging. The small high-affinity peptide tag (HiBiT), which is only 11 amino-acids in length, was engineered into a clinically used oncolytic adenovirus, and the complementary large protein (LgBiT) was constitutively expressed in tumor cells. Infection of the LgBiT expressing cells with the HiBiT oncolytic virus will reconstitute NanoLuc in the cytosol of the cell, providing strong bioluminescence upon treatment with substrate. This new bioluminescent system served as an early stage quantitative viral transduction reporter in vitro and also in vivo in mice, for longitudinal monitoring of oncolytic viral persistence in infected tumor cells. This platform provides novel opportunities for studying the biology of viruses in animal models.

Kerosene as an Alternative to Xylene in Histopathological Tissue Processing and Staining: An Experimental Study

Background

Conventional tissue processing is as old as 100 years and still remains the gold standard. Tissue processing involves many steps, of which one of the important steps is clearing. Xylene is one of the common clearing agents used in laboratory, but it is carcinogenic and teratogenic.

Aim

The aim of this study was to substitute conventionally used xylene with kerosene in tissue processing and staining.

Materials and Methods

Thirty bits of chicken tissue samples were collected; each was randomly separated into two groups: tissue processing and staining. Instead of conventional xylene, we used kerosene. The tissue blocks were subjected to sectioning and staining, and finally, they were observed under light microscope.

Results

Tissue samples that were processed and cleared with kerosene showed equal clearing and staining without any alterations of the tissue morphology and cellular details with that of xylene.

Conclusion

Kerosene can be used as a substitute to xylene without posing any health risk or compromising the cellular integrity.

A robust nonlinear tissue-component discrimination method for computational pathology

Advances in digital pathology, specifically imaging instrumentation and data management, have allowed for the development of computational pathology tools with the potential for better, faster, and cheaper diagnosis, prognosis, and prediction of disease. Images of tissue sections frequently vary in color appearance across research laboratories and medical facilities because of differences in tissue fixation, staining protocols, and imaging instrumentation, leading to difficulty in the development of robust computational tools. To address this challenge, we propose a novel nonlinear tissue-component discrimination (NLTD) method to register automatically the color space of histopathology images and visualize individual tissue components, independent of color differences between images. Our results show that the NLTD method could effectively discriminate different tissue components from different types of tissues prepared at different institutions. Further, we demonstrate that NLTD can improve the accuracy of nuclear detection and segmentation algorithms, compared with using conventional color deconvolution methods, and can quantitatively analyze immunohistochemistry images. Together, the NLTD method is objective, robust, and effective, and can be easily implemented in the emerging field of computational pathology.

Low-level laser therapy ameliorates disease progression in a mouse model of multiple sclerosis

Multiple sclerosis (MS) is an autoimmune demyelinating inflammatory disease characterized by recurrent episodes of T cell-mediated immune attack on central nervous system (CNS) myelin, leading to axon damage and progressive disability. The existing therapies for MS are only partially effective and are associated with undesirable side effects. Low-level laser therapy (LLLT) has been clinically used to treat inflammation, and to induce tissue healing and repair processes. However, there are no reports about the effects and mechanisms of LLLT in experimental autoimmune encephalomyelitis (EAE), an established model of MS. Here, we report the effects and underlying mechanisms of action of LLLT (AlGaInP, 660 nm and GaAs, 904 nm) irradiated on the spinal cord during EAE development. EAE was induced in female C57BL/6 mice by immunization with MOG35-55 peptide emulsified in complete Freund's adjuvant. Our results showed that LLLT consistently reduced the clinical score of EAE and delayed the disease onset, and also prevented weight loss induced by immunization. Furthermore, these beneficial effects of LLLT seem to be associated with the down-regulation of NO levels in the CNS, although the treatment with LLLT failed to inhibit lipid peroxidation and restore antioxidant defense during EAE. Finally, histological analysis showed that LLLT blocked neuroinflammation through a reduction of inflammatory cells in the CNS, especially lymphocytes, as well as preventing demyelination in the spinal cord after EAE induction. Together, our results suggest the use of LLLT as a therapeutic application during autoimmune neuroinflammatory responses, such as MS.

The Oncolytic Adenovirus VCN-01 as Therapeutic Approach Against Pediatric Osteosarcoma

PURPOSE

Osteosarcoma is the most common malignant bone tumor in children and adolescents. Despite aggressive chemotherapy, more than 30% of patients do not respond and develop bone or lung metastasis. Oncolytic adenoviruses engineered to specifically destroy cancer cells are a feasible option for osteosarcoma treatment. VCN-01 is a replication-competent adenovirus specifically engineered to replicate in tumors with a defective RB pathway, presents an enhanced infectivity through a modified fiber and an improved distribution through the expression of a soluble hyaluronidase. The aim of this study is to elucidate whether the use of VCN-01 would be an effective therapeutic strategy for pediatric osteosarcoma.

EXPERIMENTAL DESIGN

We used osteosarcoma cell lines established from patients with metastatic disease (531MII, 678R, 588M, and 595M) and a commercial cell line (143B). MTT assays were carried out to evaluate the cytotoxicity of VCN-01. Hexon assays were used to evaluate the replication of the virus. Western blot analysis was performed to assess the expression levels of viral proteins and autophagic markers. The antitumor effect of VCN-01 was evaluated in orthotopic and metastatic osteosarcoma murine animal models.

RESULTS

This study found that VCN-01, a new generation genetically modified oncolytic adenovirus, administered locally or systemically, had a potent antisarcoma effect in vitro and in vivo in mouse models of intratibial and lung metastatic osteosarcoma. Moreover, VCN-01 administration showed a safe toxicity profile.

CONCLUSIONS

These results uncover VCN-01 as a promising strategy for osteosarcoma, setting the bases to propel a phase I/II trial for kids with this disease. Clin Cancer Res; 22(9); 2217-25. ©2015 AACR.

A streptozotocin-induced diabetic neuropathic pain model for static or dynamic mechanical allodynia and vulvodynia: validation using topical and systemic gabapentin

Neuropathic vulvodynia is a state of vulval discomfort characterized by a burning sensation, diffuse pain, pruritus or rawness with an acute or chronic onset. Diabetes mellitus may cause this type of vulvar pain in several ways, so this study was conducted to evaluate streptozotocin-induced diabetes as a neuropathic pain model for vulvodynia in female rats. The presence of streptozotocin (50 mg/kg i.p.)-induced diabetes was initially verified by disclosure of pancreatic tissue degeneration, blood glucose elevation and body weight loss 5–29 days after a single treatment. Dynamic (shortened paw withdrawal latency to light brushing) and static (diminished von Frey filament threshold pressure) mechanical allodynia was then confirmed on the plantar foot surface. Subsequently, both static and dynamic vulvodynia was detected by application of the paradigm to the vulval region. Systemic gabapentin (75 mg/kg, i.p.) and topical gabapentin (10 % gel) were finally tested against allodynia and vulvodynia. Topical gabapentin and the control gel vehicle significantly increased paw withdrawal threshold in the case of the static allodynia model and also paw withdrawal latency in the model for dynamic allodynia when compared with the streptozotocin-pretreated group. Likewise, in the case of static and dynamic vulvodynia, there was a significant antivulvodynia effect of systemic and topical gabapentin treatment. These outcomes substantiate the value of this model not only for allodynia but also for vulvodynia, and this was corroborated by the findings not only with systemic but also with topical gabapentin.

Comparing the efficacy of coconut oil and xylene as a clearing agent in the histopathology laboratory

Background:

The commonly used clearing agent, xylene is supposed to be highly toxic and carcinogenic. As previous research studies have shown the effectiveness of different vegetable oils as clearants, this study was designed to evaluate the efficacy of coconut oil.

Materials and Methods:

Two equal halves of 60 soft tissue specimens were processed simultaneously in xylene and coconut oil as clearing agents. The Xylene-treated specimens (XY-S) and Coconut oil–treated specimens (CO-S) were checked for gross and histological features and comparison was done between the two groups.

Results:

Significant shrinkage was noted in XY-S compared to that in CO-S. No difference was found in either of the sections when checked for cellular details and staining quality. Morphometrically, there was significant reduction in the mean cell area in XY-S compared to that in CO-S.

Conclusion:

Coconut oil may be substituted for the highly hazardous xylene as a clearing agent without compromising the quality of histological details.

A comparative study to evaluate liquid dish washing soap as an alternative to xylene and alcohol in deparaffinization and hematoxylin and eosin staining

INTRODUCTION

Our study presents a new deparaffinizing and hematoxylin and eosin (H and E) staining method that involves the use of easily available, nontoxic and eco-friendly liquid diluted dish washing soap (DWS) by completely eliminating expensive and hazardous xylene and alcohol from deparaffinizing and rehydration prior to staining, staining and from dehydration prior to mounting. The aim was to evaluate and compare the quality of liquid DWS treated xylene and alcohol free (XAF) sections with that of the conventional H and E sections.

MATERIALS AND METHODS

A total of 100 paraffin embedded tissue blocks from different tissues were included. From each tissue block, one section was stained with conventional H and E (normal sections) and the other with XAF H and E (soapy sections) staining method. Slides were scored using five parameters: Nuclear, cytoplasmic, clarity, uniformity, and crispness of staining. Z-test was used for statistical analysis.

RESULTS

Soapy sections scored better for cytoplasmic (90%) and crisp staining (95%) with a statistically significant difference. Whereas for uniformity of staining, normal sections (88%) scored over soapy sections (72%) (Z = 2.82, P < 0.05). For nuclear (90%) and clarity of staining (90%) total scored favored soapy sections, but the difference was not statistically significant. About 84% normal sections stained adequately for diagnosis when compared with 86% in soapy sections (Z = 0.396, P > 0.05).

CONCLUSION

Liquid DWS is a safe and efficient alternative to xylene and alcohol in deparaffinization and routine H and E staining procedure. We are documenting this project that can be used as a model for other histology laboratories.

Comparative efficacy of cedarwood oil and xylene in hematoxylin and eosin staining procedures: An experimental study

Background:

Xylene is used as a clearing agent in hematoxylin and eosin (H and E) staining of tissue sections in routine histopathology based diagnosis. However, the hazards associated with exposure to xylene are of concern. Numerous solutions mainly essential oils have been evaluated in the past as clearing agents, which can possibly be substituted for xylene during the routine tissue processing.

Aim:

The aim of this study is to compare the efficacy of essential oil (cedarwood oil), as a possible replacement for xylene in H and E staining procedures.

Materials and Methods:

The study was carried out in the Department of Oral Pathology and Microbiology. Thirty paraffin blocks of the routine biopsy specimen were retrieved from the department archives. The cedarwood oil was procured from organic and essential oil dealer in the local market. Two to three paraffin sections of four micron thickness were cut from each of the 30 paraffin blocks of processed tissue specimens, were subjected to different clearing agents: Essential oil (8% cedarwood oil) or xylene and stained with H and E stain. The stained sections were scored based on nuclear and cytoplasmic details, clarity and uniformity of staining.

Results:

Significant correlation was observed between cedarwood oil and xylene in terms of the three staining quality parameters assessed.

Conclusions:

We conclude that cedarwood oil can be an effective, eco-friendly and safe alternative to xylene as a clearing agent in the histopathological laboratory.

Delta-24-RGD oncolytic adenovirus elicits anti-glioma immunity in an immunocompetent mouse model

Background

Emerging evidence suggests anti-cancer immunity is involved in the therapeutic effect induced by oncolytic viruses. Here we investigate the effect of Delta-24-RGD oncolytic adenovirus on innate and adaptive anti-glioma immunity.

Design

Mouse GL261-glioma model was set up in immunocompetent C57BL/6 mouse for Delta-24-RGD treatment. The changes of the immune cell populations were analyzed by immunohistochemistry and flow cytometry. The anti-glioma immunity was evaluated with functional study of the splenocytes isolated from the mice. The efficacy of the virotherapy was assessed with animal survival analysis. The direct effect of the virus on the tumor-associated antigen presentation to CD8+ T cells was analyzed with an in vitro ovalbumin (OVA) modeling system.

Results

Delta-24-RGD induced cytotoxic effect in mouse glioma cells. Viral treatment in GL261-glioma bearing mice caused infiltration of innate and adaptive immune cells, instigating a Th1 immunity at the tumor site which resulted in specific anti-glioma immunity, shrunken tumor and prolonged animal survival. Importantly, viral infection and IFNγ increased the presentation of OVA antigen in OVA-expressing cells to CD8+ T-cell hybridoma B3Z cells, which is blocked by brefeldin A and proteasome inhibitors, indicating the activity is through the biosynthesis and proteasome pathway.

Conclusions

Our results demonstrate that Delta-24-RGD induces anti-glioma immunity and offers the first evidence that viral infection directly enhances presentation of tumor-associated antigens to immune cells.

Efficacy of 1.5% dish washing solution and 95% lemon water in substituting perilous xylene as a deparaffinizing agent for routine h and e staining procedure: a short study

Aim. To assess the efficacy of dish washing solution and diluted lemon water in deparaffinizing sections during conventional hematoxylin and eosin staining technique. Objective. The objective is to utilize eco-friendly economical substitute for xylene. Materials and Methods. Using twenty paraffin embedded tissue blocks, three sections each were prepared. One section was stained with conventional H and E method (Group A) and the other two sections with xylene-free (XF) H and E (Groups B and C). Staining characteristics were compared with xylene and scoring was given. Total score of 3-5 was regarded as adequate for diagnosis and less than that inadequate for diagnosis. Statistical Analysis. Chi-square test, Kruskal Wallis ANOVA test, and Mann-Whitney U test were used. Results. Adequacy of nuclear staining, crispness, and staining for diagnosis were greater in both Groups A and C (100%) than Group B (95%). Adequacy of cytoplasmic staining was similar in all the three groups (100%). Group B showed comparatively superior uniform staining and less retention of wax. Conclusion. Dish washing solution or diluted lemon water can be replaced for xylene as deparaffinizing agent in hematoxylin and eosin procedure.

Biosafe alternative to xylene: A comparative study

BACKGROUND

Xylene in one of the non-substitutable chemical used in histology laboratories. However, it is known to have many toxic effects. The toxic effects of xylene include heart and kidney injuries, some fatal blood dyscrasia and other less dangerous problems, such as skin erythema, drying, scaling and secondary infections. The exposure and handling of xylene is maximum during deparaffinizing tissue sections.

AIMS

The aim of this study was to evaluate the efficacy of 1.7% dishwashing soap (DWS) solution as a deparaffinizing agent for hematoxylin and eosin (H and E) staining and compare it with xylene.

MATERIALS AND METHODS

Sixty sections of 4 μm were obtained from 30 formalin-fixed paraffin-embedded (FFPE) tissues and were considered in two different groups, groups A and B. Slides in group A were stained with routine H and E staining procedure; whereas, slides in group B were stained using 1.7% DWS as a deparaffinizing agent.

STATISTICAL ANALYSIS USED

Wilcoxon matched-pairs signed rank test was used to calculate the test of significance (P-value significant at ≤0.05).

RESULTS AND CONCLUSION

1.7% DWS was found to be an effective alternative deparaffinizing agent to xylene and meanwhile facilitating as less biohazardous, economical and a faster deparaffinizing agent.

Synthetically modified bioisosteres of salicyl alcohol and their gastroulcerogenic assessment versus aspirin: biochemical and histological correlates

The present study was conducted to synthesize nitrogen containing derivatives of salicyl alcohol and to investigate in vivo their ulcerogenic potential in comparison with aspirin in rats. The compounds [4-(2-hydroxybenzyl) morpholin-4-iumchloride (I)] and [1,4-bis(2-hydroxybenzyl) piperazine-1,4-diium chloride (II)] were synthesized and their chemical structures were characterized using spectral data. In our previous study (Ali et al., Afr J Pharm Pharmacol 7:585-596, 2013), both compounds showed anti-inflammatory, antinociceptive, and antipyretic properties in standard animal models and a greater binding affinity for cyclooxygenase-2 versus cyclooxygenase-1 in molecular docking and dynamics analysis. For in vivo studies, animals were randomly divided into four groups. The synthetic compounds (both at 100 or 150 mg/kg), aspirin (150 mg/kg), or saline vehicle was administered orally, once daily for 6 days and then tested for ulcerogenic activity. At the end of the procedure, gastric juice and tissues were collected and subjected to biochemical and histological analyses. The results of the study revealed that in the case of the aspirin-treated group, there was a significant increase in gastric juice volume, free acidity, total acidity, and ulcer score and a decrease in gastric pH. Moreover, histological examination of the gastric mucosa of the aspirin-treated group indicated morphological changes while neither of the synthetic compounds showed any significant ulcerogenic or cytotoxic properties. The results of the present study suggest that both compounds are free from ulcerogenic side effects and may represent a better alternative to aspirin.

Comparative evaluation of gastroulcerogenic potential of nitrogen isoforms of salicyl alcohol and aspirin in rats: biochemical and histological study

The aim of the current study was to explore in vivo any relative gastroulcerogenic prospective propensity of newly synthesized nitrogen containing derivatives of salicyl alcohol; compound (I) [1-(2-hydroxybenzyl)piperidinium chloride], compound (II) [4-carbamoyl-1-(2-hydroxybenzyl)piperidinium chloride] and aspirin in albino rats. The experimental groups received the following oral treatments daily for 6 days: group I saline control; group II, standard (aspirin) treatment group [150 mg/kg of body weight]; group III, test (compound I) treatment group [100, 150 mg/kg]; group IV, test (compound II) treatment group [100, 150 mg/kg]. The results showed that in the case of the aspirin treated group and compound (I) [150 mg/kg], there was a significant increase in gastric volume, free acidity, total acidity, ulcer score and a decrease in gastric pH. Furthermore, histopathological examination of gastric mucosa of these treated groups revealed detectable morphological changes. Utilizing the same protocol, synthetic compound (I) [100 mg/kg] and (II) [100, 150 mg/kg] exhibited no statistically significant ulcerogenic or cytotoxic properties. A cyclooxygenase (COX) selectivity test indicated the preferential inhibition of COX-I and COX-II enzymes by compounds (I) and (II). This study therefore indicates that these synthetic compounds may possess reduced ulcerogenic potential and could be a functional substitute to aspirin.

Conventional xylene and xylene-free methods for routine histopathological preparation of tissue sections

Xylene customarily has been used as a clearing agent for routine tissue processing. Because xylene is a relatively hazardous solvent, laboratories are under pressure to seek less toxic alternatives for routine use. We prepared 30 paired soft tissue specimens for routine histopathological evaluation using conventional xylene and xylene-free methods to evaluate and compare their efficacy for fixation, processing, embedding, staining and turnaround time. All specimens were measured before and after processing. Three pathologists evaluated and scored the histological sections. Tissue shrinkage was greater when using the xylene method compared to the xylene-free method. The quality of tissue sections including tissue architecture; quality of staining; preservation of epithelial, fibrous, glandular, muscle and adipose tissue; inflammatory cells; and vascular tissue was better after using the xylene method, but differences were not statistically significant. Xylene-free method produced adequate results that nearly equaled the xylene method. Added advantages included cost effectiveness, better working atmosphere and decreased toxicity.

A study to evaluate the efficacy of xylene-free hematoxylin and eosin staining procedure as compared to the conventional hematoxylin and eosin staining: An experimental study

CONTEXT

Use of diluted dish washing solution (DWS) has been experimented successfully as a substitute for xylene to deparaffinize tissue sections during hematoxylin and eosin (H and E) staining.

AIMS

(1) Test the hypothesis that xylene- and methanol-free sections (XMF) deparaffinized with diluted DWS are better than or at par with conventional H and E sections. (2) To compare the efficacy of xylene-free sections with the conventional H and E sections.

SETTINGS AND DESIGN

Single blinded experimental study.

MATERIALS AND METHODS

Sixty paraffin blocks were considered. One section was stained with conventional H and E method (Group A) and the other with XMF H and E (Group B). Slides were scored for parameters; nuclear staining, cytoplasmic staining (adequate = score1, inadequate = score0), uniformity, clarity, crispness (present = score1, absent = score0). Score >/= 2 was inadequate for diagnosis and 3-5 was adequate for diagnosis.

STATISTICAL ANALYSIS USED

Z test.

RESULTS

Adequate nuclear staining, 96.66% sections in group A and 98.33% in Group B (Z = 0.59, P>0.05); adequate cytoplasmic staining, 93.33% in group A and 83.33% in Group B (Z = 1.97, P<0.05); uniform staining, 70% in group A, 50% in group B (Z = 1.94, P<0.05), clarity present in 85% of group A, 88.33% of group B sections (Z = 0.27, P>0.05), crisp staining in 76.66% in group A and 83.33% in Group B (Z = 1.98, P<0.05), 88.33% Group A sections stained adequately for diagnosis as compared with 90% in Group B (Z = 0.17, P>0.05).

CONCLUSION

Xylene- and methanol-free H and E staining is a better alternative to the conventional H and E staining procedure.

Replacing xylene with n-heptane for paraffin embedding

In standard histological technique, aromatic solvents such as xylene and toluene are used as clearing agents between ethanol dehydration and paraffin embedding. In addition, these solvents are used for de-waxing paraffin sections. Unfortunately, these solvents are harmful and therefore adequate substitutes would be useful. We suggest the use of n-heptane as a convenient substitute for xylene. Paraffin sections of rat tissues processed with n-heptane and stained with hematoxylin-eosin or Masson's trichrome showed proper embedment, well preserved morphology and excellent staining.

Protective effect of Acer mono Max. sap on water immersion restraint stress-induced gastric ulceration

Acer mono Max. sap (AmMs) is called 'Gol-Li-Su' or 'Go-Lo-Soe' in Korean, which means 'water beneficial to the bones'. It is reported that the sap contains several types of minerals and sugars. In particular, the calcium concentration of the sap is 36.5 times higher than that of commercial mineral water. Apart from its anti-osteoporosis effect, no reports have addressed the biological activities of AmMs against degenerative diseases. In the present study, we investigated whether AmMs alleviates gastric ulcer-related symptoms in a stress-induced mouse model. To assess the effect of AmMs on gastric ulcer-like symptoms, we carried out a water immersion restraint (WIRE) test and found that AmMs has potential in alleviating gastric ulcers in a concentration-dependent manner. These results indicate that the nutritional factors of the sap mitigate the gastric ulcer-related symptoms caused by stress-induced gastric lesions in mice. AmMs-treated mice exhibited a significant decrease in the ulcer index as compared to those treated with omeprazole or L-arginine. To examine one potential mechanism underlying this effect, we performed reverse transcription-polymerase chain reaction to ascertain whether molecular markers were associated with the mitigation of the gastric lesions. Epithelial and/or tissue nitric oxide synthase (NOS) was assessed to determine whether or not the genes were down-regulated dose-dependently by the sap. The levels of these enzymes were found to be lower in the tissue samples treated with AmMs compared with the levels in the control samples. These findings collectively suggest that AmMs significantly protects the gastric mucosa against WIRE stress-induced gastric lesions, at least in part, by alleviating inducible NOS and/or neuronal NOS expression.

Reduction of matrix metalloproteinase-9 expression by culture filtrate of Paecilomyces farinosus J3

The aim of the present study was to investigate the anti-tumor effects of a culture filtrate of Paecilomyces farinosus J3. Various anti-tumor assays using B16 melanoma cells were carried out. Paecilomyces farinosus J3 significantly decreased the wound healing capability, invasiveness and angiogenic activity, which was confirmed by wound healing, human umbilical vein endothelial cell and invasion assays. Paecilomyces farinosus J3 strongly inhibited cell migration, tube formation and the angiogenic process in a concentration-dependent manner. Zymographic analysis also indicated a reduced expression of matrix metalloproteinase-9 (MMP-9), a 92-kDa gelatinase. Taken together, the results indicate that the anti-tumor activities of Paecilomyces farinosus J3 originate from the reduction of MMP-9 expression in B16F10 cells.

Histology without xylene

After the hazardous effects of xylene became indisputable in the 1970s, many potential substitutes became available, some with as many if not more hazards. This article discusses the inadequacy of 5 vegetable oils as substitutes, as well as the characteristics of 22 D-limonene-based substitutes, all less effective in their chemical role, some capable of inducing health problems, and costing more than twice as much as xylene. Some of the 35 alkane-based substitutes discussed are effective for tissue processing, less toxic, with a cost about the same as xylene, but are not very effective for dewaxing and other staining tasks. Isopropanol (2-propanol) alone or mixed with molten paraffin is a technically acceptable and cost-effective substitute for xylene for tissue processing, but in this study, we demonstrate that the best clearing agents from the sectioning quality and diagnostic value point of view, with automated or manual protocols, are mixtures of 5:1 and 2:1 isopropanol and mineral oil, followed by undiluted mineral oil, all at 50 degrees C, making them a safer and cheaper substitute than xylene. Using a 1.7% dishwasher soap aqueous solution at 90 degrees C to dewax before staining and oven drying the stained sections before coverslipping will eliminate xylene from the staining tasks. Tissue processors retorts and conduits can be dewaxed with a 2% solution of a strong glassware laboratory detergent. These 4 methodologies will make the histology laboratory xylene-free but, due to the natural resistance to change, many histotechs will be reluctant to adopt them if they think that their technical expertise could be jeopardized, and the only way these changes will succeed is if the pathologists, as stewards of the histology laboratory, commit to their implementation.

Delta-24-RGD in combination with RAD001 induces enhanced anti-glioma effect via autophagic cell death

Novel therapies are clearly needed for the treatment of gliomas, and strategies that involve combining oncolytic vectors with chemotherapy hold out significant hope for a more effective treatment of this malignancy. Whether chemotherapy acts directly on tumor cells by inducing cell arrest or cell death, or indirectly by blocking tumor angiogenesis, the resulting delay in tumor growth may provide the oncolytic virus with a wider window of opportunity to overcome the challenge imposed by the growth kinetics of the tumor. In this study we sought to determine whether the oncolytic adenovirus Delta-24-RGD, in combination with everolimus (RAD001), would result in an enhanced anti-glioma effect in vivo. Viability assays showed that Delta-24-RGD antitumoral activity is synergistically enhanced by combination with RAD001. Interestingly, combination treatment of Delta-24-RGD with RAD001 induced autophagy in vitro. We showed that Delta-24-RGD improved survival of tumor-bearing animals in a dose-dependent manner. A significant finding was that RAD001 enhanced the anti-glioma effect of Delta-24-RGD and resulted in the long-term survival of 80% of the experimental animals. Immunostaining of the treated tumors showed upregulation of Atg5, thereby indicating the therapeutic induction of autophagy. This is the first report showing that Delta-24-RGD plus RAD001 causes autophagic cell death, and dramatically increases long-term survival rates of glioma-bearing animals.

ICOVIR-5 shows E2F1 addiction and potent antiglioma effect in vivo

During 2007, approximately 200,000 people in the United States will be diagnosed with brain tumors. Gliomas account for 77% of primary malignant brain tumors, and the prognosis has hardly changed in the past 20 years, with only 30% of patients with malignant glioma surviving 5 years after diagnosis. Oncolytic adenoviruses are promising therapies for the treatment of gliomas. Here, report the antiglioma activity of the tumor-selective ICOVIR-5 adenovirus, which encompasses an early 1A adenoviral (E1A) deletion in the retinoblastoma (Rb) protein-binding region, substitution of the E1A promoter for E2F-responsive elements, and an RGD-4C peptide motif inserted into the adenoviral fiber to enhance adenoviral tropism. Mechanistic studies showed a dramatic addiction of ICOVIR-5 to the E2F1 oncogene in vitro and in vivo. This addiction was mediated by the occupancy of the ectopic adenoviral E2F1-responsive elements by the endogenous E2F1 protein resulting in high level of E1A expression in cancer cells and potent antiglioma effect. Importantly, we showed for the first time the ability of oncolytic adenoviruses to enhance E2F transcriptional activity in vivo, and we provided direct evidence of the interaction of the E2F1 protein with native and ectopic adenovirus promoters. Restoration of Rb function led to the association of Rb/E2F1 repressor complexes with ICOVIR-5 ectopic E2F1 promoter and subsequent down-modulation of E1A, dramatically impairing adenoviral replication. In xenografted mice, intratumoral injection of ICOVIR-5 resulted in a significant improvement of the median survival (P < 0.0001), and furthermore, led to 37% of long-term survivors free of disease. The antitumor activity of ICOVIR-5 suggests that it has the potential to be an effective agent in the treatment of gliomas.

Histology safety: now and then

Histology safety usually focuses on general laboratory issues, but this article concentrates on the hazards affecting the individual histotech and their evolution in the last half a century. Using the information from a survey especially designed for the occasion, the hazards were divided into 4 groups, and their prevalence was expressed as percentages for national and foreign laboratories. All the laboratories received a "safety index" (SI) with an average value of 0.77 +/- 0.11 for 63 national laboratories and 0.69 +/- 0.13 for 22 foreign laboratories, these 2 averages being statistically different (P < .02). The historical evolution of the SI required answering the same questionnaire retrospectively, and so it was done for 17 laboratories with an SI average of 0.27 +/- 0.12 for 1955/1989 and 0.77 +/- 0.13, almost 3 times larger for 1990/2007, with improvement of all safety issues. The technological, organizational, and regulatory advances before 1989 showed an unremarkable effect on the SI, and the only circumstance considered as the driving force behind the almost triple increment of the SI during 1990/2007 was the awareness that the AIDS epidemic instilled in the minds and consciences of the medical laboratory personnel in general. Even after almost tripling the average SI value in 2007, national histology laboratories obtained a grade average of "C+" only, leaving room for improvement.

Preclinical characterization of the antiglioma activity of a tropism-enhanced adenovirus targeted to the retinoblastoma pathway

BACKGROUND

Oncolytic adenoviruses are promising therapies for the treatment of gliomas. However, untargeted viral replication and the paucity of coxsackie-adenovirus receptors (CARs) on tumor cells are major stumbling blocks for adenovirus-based treatment. We studied the antiglioma activity of the tumor-selective Delta-24 adenovirus, which encompasses an early 1 A adenoviral (E1A) deletion in the retinoblastoma (Rb) protein-binding region, and of the Delta-24-RGD adenovirus. Delta-24-RGD has an RGD-4C peptide motif inserted into the adenoviral fiber, which allows the adenovirus to anchor directly to integrins.

METHODS

CAR and integrin expression were examined by flow cytometry in six glioma cell lines and in normal human astrocytes (NHAs). Adenoviral vectors containing green fluorescent protein (GFP) (AdGFP and AdGFP-RGD) were used to infect glioma cell lines with high or low CAR expression. Viability of glioma cells infected with different adenoviruses was assessed by trypan blue staining. Adenovirus replication was quantified with the infection-dose replication assay. Athymic mice carrying glioma xenografts received intratumoral injections of Delta-24-RGD or Delta-24 and were followed for survival, which was analyzed by the Kaplan-Meier method and the log-rank test. All statistical tests were two-sided.

RESULTS

Half the glioma cell lines expressed low levels of CAR (defined as <50% of cells expressing detectable CAR); all lines expressed integrins in more than 50% of cells. Infection of U-87 MG cells (a low-CAR-expressing line) with AdGFP-RGD resulted in approximately six times more GFP-positive cells than infection with AdGFP. Delta-24-RGD was more cytopathic to both low- and high-CAR-expressing glioma lines than Delta-24, and it replicated more efficiently in both cell lines. In the xenografted mice, intratumoral injection of Delta-24-RGD was associated with longer survival than intratumoral injection of Delta-24 (P<.001, log-rank test). Furthermore, 60% of Delta-24-RGD-treated mice but only 15% of Delta-24-treated mice survived more than 4 months (difference = 45%, 95% CI = 21% to 68%).

CONCLUSIONS

The antitumor activity of Delta-24-RGD suggests that it has the potential to be an effective agent in the treatment of gliomas.