Complex In Vitro Model Characterization for Context of Use in Toxicologic Pathology: Use Cases by Collaborative Teams of Biologists, Bioengineers, and Pathologists.

Complex in vitro models (CIVMs) offer the potential to increase the clinical relevance of preclinical efficacy and toxicity assessments and reduce the reliance on animals in drug development. The European Society of Toxicologic Pathology (ESTP) and Society for Toxicologic Pathology (STP) are collaborating to highlight the role of pathologists in the development and use of CIVM. Pathologists are trained in comparative animal medicine which enhances their understanding of mechanisms of human and animal diseases, thus allowing them to bridge between animal models and humans. This skill set is important for CIVM development, validation, and data interpretation. Ideally, diverse teams of scientists, including engineers, biologists, pathologists, and others, should collaboratively develop and characterize novel CIVM, and collectively assess their precise use cases (context of use). Implementing a morphological CIVM evaluation should be essential in this process. This requires robust histological technique workflows, image analysis techniques, and needs correlation with translational biomarkers. In this review, we demonstrate how such tissue technologies and analytics support the development and use of CIVM for drug efficacy and safety evaluations. We encourage the scientific community to explore similar options for their projects and to engage with health authorities on the use of CIVM in benefit-risk assessment.

Computer-assisted image analysis of preexisting histological patterns of the cephalic vein to predict wrist arteriovenous fistula non-maturation.

BACKGROUND: We used computer-assisted image analysis to determine whether preexisting histological features of the cephalic vein influence the risk of non-maturation of wrist fistulas. METHODS: This study focused on patients aged 20-80 years who underwent their first wrist fistula creation. A total of 206 patients participated, and vein samples for Masson's trichrome staining were collected from 134 patients. From these, 94 patients provided a complete girth of the venous specimen for automatic image analysis. Maturation was assessed using ultrasound within 90 days after surgery. RESULTS: The collagen to muscle ratio in the target vein, measured by computer-assisted imaging, was a strong predictor of non-maturation in wrist fistulas. Receiver operating characteristic analysis revealed an area under the curve of 0.864 (95% confidence interval of 0.782-0.946, p < 0.001). The optimal cut-off value for the ratio was 1.138, as determined by the Youden index maximum method, with a sensitivity of 89.0% and specificity of 71.4%. For easy application, we used a cutoff value of 1.0; the non-maturation rates for patients with ratios >1 and ≤ 1 were 51.7% (15 out of 29 patients) and 9.2% (6 out of 65 patients), respectively. Chi-square testing revealed significantly different non-maturation rates between the two groups (X2 (1, N = 94) = 20.9, p < 0.01). CONCLUSION: Computer-assisted image interpretation can help to quantify the preexisting histological patterns of the cephalic vein, while the collagen-to-muscle ratio can predict non-maturation of wrist fistula development at an early stage.

Influence of loading and grafting on hard- and soft-tissue healing at immediately placed implants: An experimental study in minipigs.

AIM: To histologically evaluate the influence of (1) loading and (2) grafting on osseointegration and peri-implant soft-tissue healing at immediately placed, self-cutting progressive tissue-level implants (TLX) in a minipig model. MATERIALS AND METHODS: TLX implants (n = 56) were immediately placed following the extraction of the mandibular first and second premolars, bilaterally, in a total of n = 14 minipigs. In each animal, the implant sites were allocated to the following four groups: (1) unloaded with simultaneous grafting using a bovine bone mineral; (2) unloaded without grafting; (3) loaded with simultaneous grafting; and (4) loaded without grafting. Histomorphometric assessments at 4 and 12 weeks (n = 7 animals each) included primary (i.e., bone-to-implant contact [BIC]) and secondary outcome measures (e.g., first BIC [fBIC], junctional epithelium length [JE], connective tissue contact length [CTC], biological width [BW = JE + CTC]). RESULTS: At 4 weeks, mean BIC values ranged from 74.5 ± 11.6% in Group 2 to 83.8 ± 13.3% in Group 1, and, at 12 weeks, from 75.5% ± 7.9% in Group 2 to 79.9 ± 8.6% in Group 1. Multivariate linear mixed regression did not reveal any associations between BIC and implant loading or grafting at 4 and 12 weeks. At 12 weeks, significantly higher fBIC values were noted in Group 2 when compared with Group 1. All groups showed comparable JE, CTC, and BW values. CONCLUSIONS: Implant loading and grafting had no major effects on osseointegration and peri-implant soft tissue healing at TLX implants.

Influence of antiresorptive/antiangiogenic therapy on the extension of experimentally induced peri-implantitis lesions.

OBJECTIVES: To investigate the extension of experimentally induced peri-implantitis lesions under various antiresorptive and antiangiogenic medications. MATERIAL AND METHODS: Fourty-eight albino rats had randomly received the following medications (dual application, n = 8 each): (1) amino-bisphosphonate (zoledronate) (Zo), (2) RANKL inhibitor (denosumab) (De), (3) antiangiogenic (bevacizumab) (Be), (4) Zo+Be, (5) De+Be, or (6) no medication (Co). Ligature- and lipopolysaccharide-induced peri-implantitis lesions were established at 2 maxillary implants over a period of 16 weeks. Histological (e.g., apical extension and surface area of the inflammatory cell infiltrate-aICT, ICT; defect length; defect width; CD68 positive cells) and bone micromorphometric (µCT) outcomes were assessed. The animal was defined as a statistical unit. RESULTS: A total of n = 38 animals (Zo = 6, De = 6, Be = 8, Zo + Be = 6, De + Be = 5, Co = 7) were analyzed. ICT's were commonly marked by a positive CD68 antigen reactivity. Comparable median aICT (lowest-Zo: 0.53 mm; highest-Be: 1.22 mm), ICT (lowest-De + Be: 0.00 mm2; highest-Co: 0.49 mm2), defect length (lowest-Zo: 0.90 mm; highest-Co: 1.93 mm) and defect width (lowest-De+Be: 1.27 mm; highest-Be: 1.80 mm) values were noted in all test and control groups. Within an inner (diameter: 0.8 mm) cylindric volume of interest, the bone microstructure did not significantly differ between groups. CONCLUSIONS: The present analysis did not reveal any marked effects of various antiresorptive/ antiangiogenic medications on the extension of experimentally induced peri-implantitis lesions. CLINICAL RELEVANCE: The extension of peri-implantitis lesions may not be facilitated by the antiresorptive and antiangiogenic medications investigated.

Influence of antiresorptive/antiangiogenic therapy on the surgical treatment outcomes of experimentally induced peri-implantitis lesions.

OBJECTIVE: To investigate the influence of various antiresorptive and antiangiogenic medications on the resolution of experimentally induced peri-implantitis lesions after different surgical treatment approaches. MATERIALS AND METHODS: Forty-eight albino rats randomly received a dual application of the following medications: (1) amino-bisphosphonate (zoledronate (Zo)) (n = 8), (2) RANKL inhibitor (denosumab (De)) (n = 8), (3) antiangiogenic (bevacizumab (Be)) (n = 8), (4) Zo + Be (n = 8), (5) De + Be (n = 8), or (6) no medication (control (Co)) (n = 8). Ligature-induced peri-implantitis lesions were established at 2 maxillary implants over 16 weeks. Afterward, animals were randomly treated either with open flap debridement (OFD) or reconstructive therapy (RT). Treatment procedures were followed by a 12-week healing period. The histological outcomes included residual defect length (DL); defect width (DW) at the bone crest (BC-DW); 25%, 50%, and 75% of the DL; and areas of inflammatory cell infiltrate (ICT). When present, areas of bone sequester (BS) were assessed considering the animal as a statistical unit. RESULTS: A total of 21 animals were analyzed (Zo: RT = 3, OFD = 1; De: RT = 3, OFD = 2; Be: OFD = 1; Zo + Be: RT = 2, OFD = 2; Co: RT = 3, OFD = 2). Implant loss rates were comparable among the experimental groups. Except for the 25% and 75% DW values that were significantly higher in the Zo + Be group compared to the Co group (p = 0.04 and p = 0.03, respectively), no significant differences were found among the experimental groups for the DL (lowest-Be: 0.56 mm; highest-Co: 1.05 mm), BC-DW (lowest-De: 0.86 mm, highest-Co: 1.07 mm), 50% DW (lowest-De: 0.86 mm; highest-Be + Zo: 1.29 mm), and ICT (lowest-Be: 0.56 mm2; highest-Be + Zo: 1.65 mm2). All groups, except for the Zo and Be following RT, showed presence of BS. CONCLUSIONS: The present findings did not reveal a marked effect of various antiresorptive/antiangiogenic medications on the resolution of experimentally induced peri-implantitis lesions, regardless of the surgical approach employed (OFD and RT). CLINICAL RELEVANCE: Resolution of peri-implantitis lesions may not be affected by the investigated antiresorptive/antiangiogenic medications.

Influence of antiresorptive/antiangiogenic therapy on changes in periodontal and oral tissue structures: a histomorphometrical analysis in rats.

OBJECTIVE: The objective of this study was to investigate the influence of various antiresorptive and antiangiogenic medications on morphological changes in periodontal and oral tissue structures. MATERIALS AND METHODS: Fifty-five Wistar rats randomly received dual application (i.e., at baseline and after 12-weeks) one of the following medications: (1) amino-bisphosphonate [zoledronate (Zo)], (2) RANKL inhibitor [denosumab (De)], (3) antiangiogenic [bevacizumab (Be)], (4) Zo + Be, (5) De + Be or (6) no medication [Control (Co)]. Periodontal and oral tissue biopsies were obtained at 17 (n = 21 animals, Phase 1, (De = 3, De + Be = 3, Zo = 5, Be = 3, Zo + Be = 2, Co = 5) and 29 (n = 34 animals, (De = 8, De + Be = 6, Zo = 2, Be = 7, Zo + Be = 4, Co = 7, Phase 2) weeks after the second drug application. The following outcomes were histomorphometrically assessed: periodontal space width in the coronal (PLS-C, mm) and apical sections (PLS- A), number of empty alveolar bone lacunae in the coronal, apical sections and at the apex at respective tooth sites (EL - C, EL- A, EL- Ap), mucosal thickness at edentulous alveolar ridge areas (MT, mm), and, when present, associated areas of inflammatory cell infiltrates (ICI, mm2). RESULTS: Comparable mean PLS-C, PLS-A, ET-A, ET-C, ET-Ap, and MT values were observed in all experimental groups after Phases 1 and 2. The presence of ICI was identified in 3 animals in the Co group (Phase 1: 1, Phase 2: 2), and 17 animals in the test groups (Phase 1: 4; Phase 2: 14). The estimated ICI surface area was significantly higher in the Zo + Be group, followed by the Zo and Be groups compared to that measured in the Co group. The time (i.e., Phases 1 and 2) was not found to be a predictor for the extent of the ICI area. In all groups, the EL-C, EL-A, and EL-Ap values were significantly higher after Phase 2 compared to those assessed after Phase 1. The MT values were significantly reduced in all groups after Phase 2 compared to those measured after Phase 1. CONCLUSIONS: The present evaluation was not able to find any morphological effects of different antiresorptive and antiangiogenic medications on periodontal and oral tissue structures. The presence of inflammatory cell infiltrates was more frequently observed in the animals administered with antiresorptive and antiangiogenic medications as well as combinations thereof. CLINICAL RELEVANCE: Administration of antiresorptive and antiangiogenic medications may be capable of inducing inflammatory reactions in periodontal tissues.

The atrioventricular conduction axis and the aortic root-Inferences for transcatheter replacement of the aortic valve.

Conduction problems still occur following transcatheter aortic valvar replacement. With this in mind, we have assessed the relationship of the conduction axis to the aortic root. We used serial histological sections, made perpendicular to the base of the triangle of Koch in nine hearts, and perpendicular to the aortic root in 11 hearts. We first defined the extent of the fibrous tissues forming the boundaries of an infero-septal recess of the subaortic outflow tract, found in all datasets but one. When the recess was present, the axis penetrated through its rightward wall, giving rise to the left bundle branch prior to entering the outflow tract. The axis itself was usually on the crest of the ventricular septum, but could be deviated leftward or rightward. Its proximity to the virtual basal plane reflected the angulation of the muscular septum. On average, the superior edge of the left bundle was within 3.3 mm of the hinge of the right coronary leaflet, with a range from 0.4 to 10.2 mm. The arrangement was markedly different in the case lacking an infero-septal recess. Our findings necessitated a redefinition of the right fibrous trigone and the central fibrous body. The atrioventricular conduction axis, having entered the aortic root, is usually closest at the hinge of the right coronary leaflet. Knowledge of the depth of the infero-septal recess, and the angulation of the muscular ventricular septal, may help to avoid conduction problems following transcatheter implantation of the aortic valve.

Histomorphometrical assessment of vertical alveolar ridge augmentation using extracted tooth roots in the canine.

OBJECTIVES: To histomorphometrically evaluate the influence of autoclavation on the efficacy of extracted tooth roots (TR) used for vertical alveolar ridge augmentation. MATERIALS AND METHODS: Upper premolars were randomly assigned to either autoclavation (TR-A) or an untreated control group (TR-C) and used as block grafts for vertical alveolar ridge augmentation in both lower quadrants (n = 4 beagle dogs). Tissue biopsies were obtained after 15 weeks of submerged healing. Histological analyses considered gain in ridge height (GRH), augmented area (AA), and the proportion of mineralized (MT) and non-mineralized tissue (NMT). RESULTS: TR-C and TR-A grafts were commonly associated with a complete replacement resorption and a marked gain in ridge height. Significant differences between groups were noted for mean GRH [TR-C: 2.35 ± 0.55 vs. TR-A: 2.46 ± 0.21 mm] and AA [TR-C: 11.88 ± 4.31 vs. TR-A: 8.65 ± 1.59 mm2] values. Within AA, both groups revealed a comparable distribution of mean MT and NMT values. The linear regression analysis pointed to a significant correlation between NMT and AA values. CONCLUSIONS: Both TR-C and TR-A grafts supported vertical alveolar ridge augmentation; however, GRH was improved in the TR-A group. CLINICAL RELEVANCE: TR grafts may serve as a potential alternative for vertical alveolar ridge augmentation.

Influence of autoclavation on the efficacy of extracted tooth roots used for vertical alveolar ridge augmentation.

OBJECTIVES: To assess the influence of autoclavation on the efficacy of extracted tooth roots (TR) used for vertical alveolar ridge augmentation and two-stage osseointegration. MATERIAL AND METHODS: Maxillary premolars were randomly assigned to either autoclavation (TR-A) or were left untreated (TR-C) and used as block grafts for vertical alveolar ridge augmentation in both lower quadrants (n = 4 beagle dogs). At 12 weeks, titanium implants were inserted and left to heal for 3 weeks. Histological analyses considered vertical bone gain (BD-BC), augmented area (AA) and bone-to-implant contact (BIC) at vestibular (v) and oral (o) aspects. RESULTS: Both TR-C and TR-A (exposures n = 3) grafts were associated with a replacement resorption and marked vertical bone gain. Median BD-BC (TR-C: 1.45 [v] to 1.62 mm [o] versus TR-A: 0.97 [v] to 1.79 mm [o]) and AA (TR-C: 0.64 [v] to 2.36 mm2 [o] versus TR-A: 0.22 [v] to 2.36 mm2 [o]) values were comparable in both groups. V BIC (TR-C: 49.32 [v] to 52.97% [o] versus TR-A: 25.34 [v] to 46.11% [o]) values were significantly higher in the TR-C group. CONCLUSIONS: Both TR-C and TR-A grafts equally supported vertical alveolar ridge augmentation; however, osseointegration was partially facilitated in the TR-C group.

Biomechanical, micro-computed tomographic and immunohistochemical analysis of early osseous integration at titanium implants placed following lateral ridge augmentation using extracted tooth roots.

OBJECTIVES: To assess biomechanical, micro-computed tomographic (micro CT) and immunohistochemical characteristics of early osseous integration at titanium implants placed following lateral ridge augmentation using autogenous extracted tooth roots. MATERIAL & METHODS: The roots of healthy maxillary premolars (PM) and retromolar cortical autogenous bone (AB) blocks were used for lateral ridge augmentation at chronic-type defects in the lower quadrants of n = 16 foxhounds. At 12 weeks, titanium implants were inserted and left to heal for another 3 weeks. Osteocalcin (OC) antigen reactivity, removal torque values (RT) and the bone volume per tissue volume (micro CT- BV/TV) along the implants were assessed. RESULTS: Median OC (PM: 6.71 vs. AB: 2.73%), RT (PM: 61.97 vs. AB: 44.8 Ncm) and BV/TV (PM: 0.34 vs. AB: 0.21) values were comparable in both PM and AB groups. CONCLUSIONS: PM and AB grafted sites equally supported the early stages of osseointegration.

Periodontally diseased tooth roots used for lateral alveolar ridge augmentation. A proof-of-concept study.

OBJECTIVES: To assess the efficacy of periodontally diseased tooth roots used as autografts for lateral ridge augmentation and two-stage early osseointegration of titanium implants. MATERIAL AND METHODS: Ligature-induced periodontitis lesions were established at the maxillary premolars in n = 8 foxhounds. Extracted, scaled and root planed pre-molar roots (PM-P) as well as retromolar cortical autogenous bone (AB) blocks were used for horizontal ridge augmentation of mandibular chronic-type defects. At 12 weeks, titanium implants were inserted and left to heal for another 3 weeks. Histological analyses included crestal ridge width (CW), augmented area (AA) and bone-to-implant contact (BIC). RESULTS: Both PM-P and AB grafts were gradually organized and replaced by newly formed bone. Median CW (PM-P: 3.83 versus AB: 3.67 mm), AA (PM-P: 10.18 versus AB: 9.82 mm(2) ) and BIC (PM-P: 50.00% versus AB: 35.21%) values did not reach statistical significance between groups (p > 0.05, respectively). Histologically, PM-P grafts were not associated with any inflammatory cell infiltrates. CONCLUSIONS: PM-P autografts may reveal a structural and biological potential to serve as an alternative autograft to AB.

Qualitative Comparison of Cryostat- versus Snap-Frozen Neurosurgical Intraoperative Consultations.

Background. Frozen sections (FS) are common in neurosurgery to address varied clinical concerns. Artifacts in central nervous system (CNS) FS can be severe and affect or hinder interpretation. We performed a case-control study using a semiquantitative scale: the Histologic Preservation Score (HPS), and a quantitative scale: the Ice Crystal Vacuolization Score (ICVS), to compare the histologic quality yielded by snap- versus cryostat freezing techniques. Material and Methods. All specimens were sectioned in 2 halves, one half was used for FS and the other for permanent evaluation. HPS assigns a distortion score to the FS sample using the non-frozen half as the comparator: 1 = minimal, 2 = slight, 3 = moderate, 4 & 5 = severe. The ICVS is the average size in µm of the 5 largest vacuoles/0.05 mm2, evaluated on digitized slides. Results. 86 CNS-FS were collected: 22 snap- and 64 cryostat-FS. Significant differences in HPS: 2.28 versus 2.84 (p <0.05) and ICVS 7.47 versus 14.56 (p < 0.001) were obtained for snap- versus cryostat-FS, respectively. HPS and ICVS showed a strong correlation: R2 = 0.63, p < 0.0001. Histologic distortion was worse for neuroglial than mesenchymal tissue by both methods; however, a significant difference was only observed in cryostat-FS: HPS: 3.23 versus 2.33, p < 0.001; ICVS: 16.86 µm versus 10.26 µm, p < 0.001. Conclusion. Snap-FS yields better histologic quality than cryostat-FS for CNS-FS, and the difference is more pronounced in neuroglial samples. HPS and ICVS correlate strongly, indicating that the histologic quality is inversely proportional to water-crystallization. These results may apply to other areas of surgical pathology.

Histological technique to detect the physiological age of the malaria vector mosquito Anopheles pharoensis (Diptera: Culicidae).

The risk of malaria recurrence increases due to the main vector, Anopheles pharoensis. The physiological age of the mosquito population is needed to expect malaria vector dynamics. The number of completed gonotrophic cycles is of great importance in determining the physiological age of females. A technique has been described that focuses on the number of dilatations remaining in the ovarioles after each oviposition to determine how many blood meals have been taken. At each gonotrophic cycle, the chances of infection of the vectors are repeated. The histological changes that occur immediately in the ovarioles and ovulation itself were studied. Under the influence of the contractions of the ovarian muscles, the eggs begin to move over the distal end of the ovariole into the inner oviduct. The terminal pedicle is markedly dilated near the diameter of the eggs. After the expulsion of the mature eggs, ovariole dilations were found at the point of their development in the terminal pedicle due to the accumulation of nurse cell remnants and follicular epithelium. The results were used to develop epidemiological localization and to evaluate the effectiveness of antimalaria interventions. The ovarian inspection often provides a technique to distinguish nulliparous from parous female anophelines. In addition, this study can provide basic entomological knowledge on the physiological age of mosquitoes by considering the histological changes in the ovaries, which allow the evaluation of vector management strategies in the field.

Posterior superior alveolar nerves contribute to sensation in the anterior teeth.

BACKGROUND: There is no available data on the occurrence rate of a converged alveolar canal, the detailed three-dimensional (3D) courses of alveolar canals/grooves (ACGs), or the contribution of each superior alveolar nerve to each area in the maxilla. This study aimed to clarify the 3D courses of ACGs, the relationship between ACGs and superior alveolar nerves, and the contribution of posterior superior alveolar nerves (PSANs) using computed tomography (CT) with histological analysis. METHODS: During the gross anatomy course at Niigata University, we investigated nine human cadavers. RESULTS: All anterior and posterior ACGs converged into the common alveolar canal, which contained blood vessels and several nerve bundles surrounded by perineurium, located at the nasal floor near the pyriform aperture. Histometrical analysis clarified that 16.3% of the nerve bundles in this canal were derived from PSANs, and 67% of the bundles were dispersed while they coursed down to the nasal floor. There seems to be no relationship between the density of nerve bundles in the canal and the number of remaining anterior teeth. CONCLUSIONS: Data obtained from observing the detailed 3D courses of anterior and posterior ACGs, and their relationship with superior alveolar nerves, suggest that PSANs partially contribute to the nociception of the anterior teeth.

Tackling the Mouse-on-Mouse Problem in Cochlear Immunofluorescence: A Simple Double-Blocking Protocol for Immunofluorescent Labeling of Murine Cochlear Sections with Primary Mouse Antibodies.

The mouse is the most widely used animal model in hearing research. Immunohistochemistry and immunofluorescent staining of murine cochlear sections have, thus, remained a backbone of inner ear research. Since many primary antibodies are raised in mouse, the problem of "mouse-on-mouse" background arises due to the interaction between the anti-mouse secondary antibody and the native mouse immunoglobulins. Here, we describe the pattern of mouse-on-mouse background fluorescence in sections of the postnatal mouse cochlea. Furthermore, we describe a simple double-blocking immunofluorescence protocol to label mouse cochlear cryosections. The protocol contains a conventional blocking step with serum, and an additional blocking step with a commercially available anti-mouse IgG blocking reagent. This blocking technique virtually eliminates the "mouse-on-mouse" background in murine cochlear sections, while adding only a little time to the staining protocol. We provide detailed instructions and practical tips for tissue harvesting, processing, and immunofluorescence-labeling. Further protocol modifications are described, to shorten the duration of the protocol, based on the primary antibody incubation temperature. Finally, we demonstrate examples of immunofluorescence staining performed using different incubation times and various incubation temperatures with a commercially available mouse monoclonal primary antibody. © 2020 The Authors. Basic Protocol: Tackling the Mouse-on-Mouse Problem in Cochlear Immunofluorescence: A Simple Double-Blocking Protocol for Immunofluorescent Labeling of Murine Cochlear Sections with Primary Mouse Antibodies.

Dry season diet composition of four-horned antelope Tetracerus quadricornis in tropical dry deciduous forests, Nepal.

It is essential to assess the feeding strategies of threatened species during resource-scarce seasons to understand their dietary niche breadth and inform appropriate habitat management measures. In this study, we examined the diet composition of four-horned antelope (FHA) Tetracerus and quadricornis, one of the least studied ungulate species, in Banke National Park, Nepal. A total of 53 fresh pellet groups were collected between December 2015 and January 2016 and analyzed using micro-histological fecal analysis technique. First, we prepared 133 micro-histological photographs of different parts of 64 reference plant species. Then we compared 1,590 fragments of 53 fecal samples with photographs of reference plants to assess the percentage of occurrence of different plant species in FHA diet. A total of 30 plant species belonging to 18 different families were identified in fecal samples. Chi-square goodness of fit tests showed that FHA appeared not to feed all plant uniformly. Out of 1,520 identified fragments in fecal samples, 1,300 were browse species and 220 were grass species. Browse represented 85.5% of the identified plant fragments, suggesting that FHA might be adopting a browser strategy at least during winter when grasses are low in abundance and their nutritive quality is poor. Tree species had the highest contribution in the diet (46.55%) followed by shrubs (24.52%). The family Gramineae was consumed in the highest proportion (27.68%) followed by Euphorbiaceae (11.95%). Overall, our results suggest that FHA has the feeding plasticity to adapt to resource fluctuation. Based on the findings of this study, we recommend that dicot plant species-particularly fruit trees and shrubs, which are the major source of nutrients for FHA during resource-lean, dry season-be conserved and natural regeneration of these taxa be promoted.

The effect of low-level helium-neon laser on oral wound healing.

BACKGROUND: The effectiveness of low power lasers on incisional wound healing, because of conflicting results of previous studies, is uncertain. Therefore, the aim of this study was to evaluate the effects of low-level helium-neon (He-Ne) laser irradiation on wound healing in rat's oral mucosa. MATERIALS AND METHODS: Sixty-four standardized incisions were carried out on the buccal mucosa of 32 male Wistar divided into four groups of eight animals each. Each rat received two incisions on the opposite sides of the buccal mucosa by a steel scalpel. On the right side (test side), a He-Ne laser (632 nm) was employed on the incision for 40 s. Laser radiation was used just in 1(st) day, 1(st) and 2(nd) day, 1(st) and 3(rd) day, and continuous 3 days in groups of A, B, C, and D of rats, respectively. The left side (control side) did not receive any laser. Histological processing and hematoxylin and eosin staining were done on tissue samples after 5 days. Wilcoxon and Kruskal-Wallis tests were used for statistical analysis. RESULTS: Histological analysis showed that the tissue healing after continuous 3 days on the laser irradiated side was better than the control side, but there was no difference between the two sides in each groups (P > 0.05). CONCLUSION: This study showed that He-Ne laser had no beneficial effects on incisional oral wound healing particularly in 5 days after laser therapy. Future research in the field of laser effects on oral wound healing in human is recommended.

Comparison of Prostatic Tissue Processed by Microwave and Conventional Technique Using Morphometry.

BACKGROUND AND OBJECTIVES: Rapid processing of histopathological specimens and decreased turnaround time is important to fulfill the needs of clinicians treating sick patients, so the present study was conducted to compare the time taken and quality of sections in processing of prostatic tissue by rapid microwave and conventional techniques using morphometry. METHODS: Four to five mm thick paired prostate tissue pieces of fifty cases of prostatectomy specimens were taken. One tissue piece of the pair was processed routinely overnight by conventional tissue processing and the other by microwave processing. Time taken for processing by both conventional technique and microwave technique was noted and compared. Then, both were stained with conventional method of hematoxylin and eosin staining and examined for histological typing and grading. Morphometric study was done on slides of prostatic tissue processed by both conventional and microwave technique. RESULT: The prostatectomy specimens included both benign (86%) and malignant (14%) prostatic lesions in the age range of 46-85 years. The time taken for steps of dehydration, clearing and impregnation in microwave technique was significantly less as compared to histoprocessing done by conventional technique. Morphology, staining patterns of prostatic tissue processed within minutes by microwave technique, whether benign or malignant, were comparable to those sections which were processed in days using standard technique. CONCLUSION: Domestic microwave oven can be used for histoprocessing to accelerate the processing with preservation of morphology and is cheaper than commercially available microwave ovens and processing time was considerably reduced from days to minutes.

To what extent does hyaluronic acid affect healing of xenografts? A histomorphometric study in a rabbit model

ABSTRACT Among the many graft materials that have been used for the treatment of bone defects in oral and maxillofacial regions is xenograft. To improve osteoconductive effects of xenografts, they have been combined with various biocompatible materials, such as hyaluronic acid and bone morphogenetic protein. Objective: To determine bone-healing capacity of high molecular weight hyaluronic acid (HA) combined with xenograft in rabbit calvarial bone defects. Material and methods: Ten adult male New Zealand rabbits (mean weight 3 kg) were included in the study. Three 6-mm-diameter bicortical cranial defects were created on calvarial bone of all rabbits. These defects were filled as follows: a) xenograft; b) HA+xenograft; c) autograft. One month after the first operation, rabbits were sacrificed. Specimens were evaluated histomorphometrically. Results: Considering multiple comparisons, differences regarding new bone were statistically significant between all groups (p<0.05). The volume of residual graft was significantly decreased in HA group compared to xenograft group (p=0.035). Marrow space, trabecular thickness (TbTh), trabecular width (TbWi), trabecular separation (TbSp), and number of node: number of terminus (NNd:NTm) in the autograft group were significantly better than xenograft and HA groups (p<0.05). However, regarding marrow space, TbTh, TbWi, TbSp, and NNd:NTm values, xenograft and HA groups showed similar results and the difference were not significant (p>0.05). Conclusion: These results support that high molecular weight hyaluronic acid could contribute to the healing of xenograft by improving the percentage of new bone formation and reducing the percentage of residual graft. However, HA did not significantly affect the quality of newly formed bone assessed by microarchitectural parameters.

Cochlear damages caused by vibration exposure.

BACKGROUND: Many industrial devices have an excessive vibration which can affect human body systems. The effect of vibration on cochlear histology has been as a debatable problem in occupational health and medicine. OBJECTIVES: Due to limitation present in human studies, the research was conducted to survey the influence of vibration on cochlear histology in an animal model. MATERIALS AND METHODS: TWELVE ALBINO RABBITS WERE EXPERIMENTED AS: Vibration group (n = 6; exposed to 1.0 m.s(-2) r.m.s vertical whole-body vibration at 4 - 8 Hz for 8 hours per day during 5 consecutive days) versus Control group (n = 6; the same rabbits without vibration exposure). After finishing the exposure scenario, all rabbits were killed by CO2 inhalation; their cochleae were extracted and fixed in 10% formaldehyde for 48 hours, decalcified by 10% nitric acid for 24 hours. Specimens were dehydrated, embedded, sectioned 5 µm thick and stained with Hematoxylin and Eosin for light microscopy observations. RESULTS: Severely hydropic degenerated and vacuolated inner hair cells (IHCs) were observed in vibration group compared to the control group. Inter and intracellular edema was appeared in supporting cells (SC). Nuclei of outer hair cells (OHCs) seemed to be pyknotic. Slightly thickened basilar membrane (BM) was probably implied to inter cellular edematous. Tectorial Membrane (TM) was not affected pathologically. CONCLUSIONS: Whole-body vibration could cause cochlear damages in male rabbits, though vibration-induced auditory functional effects might be resulted as subsequent outcome of prolonged high level vibration exposures.