Fixative Solution Research Articles

Investigation of the Effects of Ozon and Propolis on the Healing of Bone Defects: An Experimental Study

Background/aim: This study explores the effects of ozone and propolis on the healing of critically sized bone defects at both the histologic and molecular levels, and the locations and concentrations of osteopontin and osteonectin during healing; both proteins play roles during bone healing. Materials and methods: This study used 56 adult male Sprague-Dawley rats of an average weight of 350 g, divided into four groups of 14: a control group, a topical ozone group (O), a topical ozone + systemic propolis (O + PO) group, and a systemic propolis group (PO). Seven rats from each group were sacrificed at the end of week 4 and the other seven at the end of week 6. Tissues were subjected to histologic and immunohistochemical examinations in a fixative solution. The results were analyzed using the statistical software package SPSS 23 (Statistical Package for the Social Sciences—IBM). Results were considered significant at the 95% confidence level (P<0.05). Results: Graft sections were immunostained for osteonectin. Staining was low in the control group but moderate in the other three groups; the differences were significant. The three experimental groups did not differ significantly. Graft sections were also immunostained for osteonectin. At 4 weeks, staining was low in the control group but moderate in the other 3 groups. At 6 weeks, stronger staining was apparent in the 3 experimental groups. At both 4 and 6 weeks, the differences between the control and experimental groups were significantly different, but the differences among the experimental groups were not. Conclusion: The authors' results are compatible with the literature. Ozone and propolis, given separately or together, improved bone healing, increased bone formation, and reduced bone destruction. However, further research is required.

First experience using a plate for fixing histological specimens of parotid salivary gland tumors

Relevance. Accurately assessing all resection margins during the removal of parotid salivary gland tumors is crucial due to the risk of recurrence and the potential for benign processes to become malignant over time. Macroscopic specimens obtained during these surgeries are sent to the pathology laboratory in containers filled with fixative solution. During fixation, the soft tissue fragments, typically round in shape, can alter their configuration because of the tissue's heterogeneity. This can create challenges for the pathologist in properly orienting the surgical specimen, which in turn complicates the precise evaluation of the resection margins.Materials and methods. To address this issue, the "Plate for fixing histological specimens of parotid salivary gland tumors" (patented) was developed. Twenty cases of its clinical use were analyzed: the surgical material (parotid gland tissue containing a tumor) was sent to the pathology department, fixed on this plate to preserve its original anatomical orientation. A macroscopic and histological evaluation of the neoplasms was then carried out, with special attention given to the accurate identification of all resection margins. In all 20 clinical cases, the use of this invention improved the convenience for the pathologist in handling the excised tissue block by standardizing the method and clearly identifying the resection margins.Conclusion. The application of this invention enhances the accuracy of marking and evaluating the resection margins in parotid gland tumors.

Acute effect of the novel cadaver fixation and storage solution -Anatomical-biomechanical-microbiological study

Cadaver education is a golden standard in health sciences. It is aimed to purify the cadavers from microbes by subjecting them to chemicals and to be used for many years by terminating autolysis. As a result of literature searches, a solution consisting of a mixture of borax, nitrite-nitrate, glycerin, alcohol, and thyme oil was created. While seven sheep hearts were placed in this solution, seven were kept in 10% formaldehyde for two months for fixation and storage. At the end of the first ten days, it was observed that the discoloration of the heart in the solution was lower than the formalin fixation. In histological examinations, it was observed that there was no visual difference between the groups and the tissue could be examined at all magnifications. At the end of two months, insignificant microbial growth observed in the solution. While color changes were better than formaldehyde, texture profile analysis values were found to be closer to fresh heart. In histological examinations, in the solution group, although the tissue could be recognized at all magnifications, it was observed that cell nuclei were less stained at x100. It was concluded that this solution can be used mainly in short-term courses.

Evaluating the effectiveness of various agents as interim preservative media for biopsy specimens: An experimental in vitro study

In the field of medicine, diagnosing diseases involves various steps, procedures, and protocols. Histopathological examination remains the gold standard for a definitive and accurate diagnosis. This process relies on an initial step of tissue fixation.Formaldehyde is a traditional fixative material and is typically used as 10% or 4% buffered solutions. However, significant health risks are associated with formaldehyde exposure.Our paper aimed to evaluate and compare variable media as a preservative agent. The study included eight groups as follows: (1) normal saline 0.9%; (2) local anesthesia with epinephrine (2% Lidocaine HCl/ 1:100,000 epi); (3) local anesthesia without epinephrine (3% Mepivacaine HCl/ plain); (4) distilled water; (5) Saliva collected from healthy male participants; (6) Milk (Almarai- full-fat fresh milk); (7) Propolis; and (8) l0% formalin. Three tissue samples from each group were fixed in 10% formalin for 24 h after being preserved for 6 h at ambient temperature in their respective media. All specimens were stained with Hematoxylin and Eosin.The following histological structures were assessed: (1) superficial 1/3 of the epithelium, (2) middle 1/3 of the epithelium, (3) lower 1/3 of the epithelium, (4) basement membrane/rete ridges, (5) fibrous connective tissue, (6) blood vessels/endothelial cells, (7) skeletal muscle, (8) adipose tissue, and (9) nerve bundles. A numerical rating system was employed to assess these components, with scores ranging from 1 to 4.Our findings suggest propolis has promising potential as a tissue fixative. This study highlighted the effectiveness of propolis as a preservative and fixative solution, which warrants further investigation.

Histo-pillar strip for optimal histogel block construction and biomarker analysis in 3D-lung cancer patient-derived organoids

This study proposed an optimized histogel construction method for histological analysis by applying lung cancer patient-derived organoids (PDOs) to the developed histo-pillar strip. Previously, there is the cultured PDOs damage problem during the histogel construction due to forced detachment of the Matrigel spots from the 96-well plate bottom. To address this issue, we cultured PDO on the proposed Histo-pillar strips and then immersed them in 4% paraformaldehyde fixation solution to self-isolate PDO without damage. The 4μl patient-derived cell (PDC)/Matrigel mixtures were dispensed on the surface of a U-shaped histo-pillar strip, and the PDCs were aggregated by gravity and cultured into PDOs. Cultured PDOs were self-detached by simply immersing them in a paraformaldehyde fixing solution without physical processing, showing about two times higher cell recovery rate than conventional method. In addition, we proposed a method for embedding PDOs under conditions where the histogel temperature was maintained such that the histogel did not harden, thereby improving the problem of damaging the histogel block in the conventional sandwich histogel construction method. We performed histological and genotyping analyses using tumor tissues and PDOs from two patients with lung adenocarcinoma. Therefore, the PDO culture and improved histogel block construction method using the histo-pillar strip proposed in this study can be employed as useful tools for the histological analysis of a limited number of PDCs.

The effect of reusing formaldehyde fixative solution on the quality of histopathological slides and the amount of waste produced

The effect of reusing formaldehyde fixative solution on the quality of histopathological slides and the amount of waste produced

Immunofluorescence staining of chloroplast proteins with frozen sections of plant tissues.

Immunofluorescence staining with frozen sections of plant tissues and a nest tube is convenient and effective, and broadens the applicability of immunofluorescence staining. Immunofluorescence staining is an indispensable and extensively employed technique for determining the subcellular localization of chloroplast division proteins. At present, it is difficult to effectively observe the localization of target proteins in leaves that are hard, or very thin, or have epidermal hair or glands with the current immunofluorescence staining methods. Moreover, signals of target proteins were predominantly detected in mesophyll cells, not the cells of other types. Thus, the method of immunofluorescence staining was further explored for improvement in this study. The plant tissue was embedded with 50% PEG4000 at -60℃, which was then cut into sections by a cryomacrotome. The sections were immediately immersed in fixation solution. Then, the sample was transferred into a special nested plastic tube, which facilitated the fixation and immunofluorescence staining procedures. The use of frozen sections in this method enabled a short processing time and reduced material requirements. By optimizing the thickness of the sections, a large proportion of the cells could be well stained. With this method, we observed the localization of a chloroplast division protein FtsZ1 in the wild-type Arabidopsis and various chloroplast division mutants. Meanwhile, the localization of FtsZ1 was also observed not only in mesophyll cells, but also in guard cells and epidermal cells in a lot of other plant species, including many species with hard leaf tissues. This method is not only easy to use, but also expands the scope of applicability for immunofluorescence staining.

A proposal for new genotoxic and cytotoxic endpoints to assess chemical effects on the red algae Ceramium tenuicorne.

Macroalgae provide key contributions to aquatic ecosystems, including their role as primary producers and the provision of biotopes for marine organisms, fish spawning, and fish nurseries. The aim of this study was to evaluate the feasibility of a micronucleus test and a comet assay in Ceramium tenuicorne, a red macroalga. This alga is widely distributed in marine ecosystems and brackish waters, and is therefore a potential bioindicator of the effects of anthropogenic pollution in these ecosystems. Unfortunately, the two genotoxicity tests evaluated were not suitable for this alga because the nuclei are generally very small (between 2 and 10µm), are variable in size, and there may be several nuclei in each cell (between 1 and 5 in our observations). However, the present study allowed us to define conditions for observing these algal cells and optimizing the choice of DNA dye (orcein), cell fixation solution (Carnoy's solution), and hydrolysis step (HCl, 1200mmol/L solution for 1min). This research allowed us to propose two genotoxicity and cytotoxicity endpoints for assessing chemical effects on the algal cells: counting of nuclei in cortical cell areas, and the frequency of axial cells in mitosis. These two criteria were measured after exposing C. tenuicorne to two reference substances: cadmium chloride and maleic hydrazide, and we highlight the effects from 1 × 10-5M of CdCl2 and 5 × 10-5M of maleic hydrazide.

Investigation of the Effects of Thymoquinone and Dental Pulp-Derived Mesenchymal Stem Cells on Tibial Bone Defect Models.

The thymoquinone obtained from Nigella sativa increases osteoblastic activity and significantly reduces the number of osteoclasts, thereby accelerating bone healing. In addition, mesenchymal stem cells isolated from various tissues are considered a potential cell source for bone regenerative therapies. The aim of this study is to investigate the effectiveness of thymoquinone, a current and novel agent, in combination with mesenchymal stem cells derived from the dental pulp in promoting bone healing. In the study, 28 male Sprague Dawley rats were used. The rats were divided into 4 groups, each consisting of 7 rats: the control group (group 1) (n=7), thymoquinone group (group 2) (n=7), stem cell group (group 3) (n=7), stem cell+thymoquinone group (group 4) (n=7). A bone defect of 4mm in diameter and 5mm in length was created in the left tibial bones of all rats with a trephine bur. In group 1, no procedure was applied to the defect area. Group 2 was applied thymoquinone (10mg/kg) with oral gavage. In group 3, stem cells were used locally to the defect area. In group 4, stem cells and thymoquinone (10mg/kg) was applied to the defect area. All rats were killed on the 28th day of the experiment. Tibia tissues extracted during sacrifice were histomorphologically examined in a fixative solution. Significant differences were found in terms of new bone formation and osteoblastic activity values in the "thymoquinone" ( P <0.05), "stem cell" ( P <0.05), and "stem cell+thymoquinone" ( P <0.05) groups compared to the "control" group. In addition, while there was no significant difference in the "thymoquinone" group compared to these stem cell+thymoquinone group in terms of osteoblastic activity ( P >0.05), the difference in terms of new bone formation was found to be significantly lower. No significant differences among the other groups were observed in new bone formation and osteoblastic activity ( P >0.05). According to the results of our study, stem cell+thymoquinone treatment for bone defects is not only more effective than thymoquinone or stem cell treatment alone but also induces greater development of bone trabeculae, contributes to the matrix and connective tissue formation, and increases the number of osteoblasts and osteocytes involved in bone formation.

Vascular rehabilitation in children with chronic intestinal failure reduces the risk of central-line associated bloodstream infections and catheter replacements

Background & AimsChildren with chronic intestinal failure (IF) require a long-term central venous catheter (CVC) for provision of parenteral nutrition. Vascular, mechanical and infectious complications such as central line-associated bloodstream infections (CLABSI) may lead to progressive loss of venous access sites. Handling and management of CVCs therefore play an important role. Our vascular rehabilitation concept (VRC) is a core component of our intestinal rehabilitation program (IRP) and consists of an education program, optimization of skin care, catheter fixation and lock solution, and the use of hybrid technique for catheter placement.Aim of this study is to analyse the effectiveness of our VRC on CLABSI rates and need for CVC replacements. MethodsRetrospective analysis of all children treated in our IRP that were followed up between 2018 and 2023. ResultsA total of 117 children with chronic IF could be included for analysis of 248864 catheter days (CD). 91 patients were referred from other hospitals (127117 CD before and 89359 CD after entry into our IRP). Children receiving primary care at our IRP (32388 CD) showed a significantly lower CLABSI and line replacement rate than patients referred from external centers (p<0.001). After entering our IRP, CLABSI rates and need for CVC replacements per 1000 CD decreased significantly in referred patients: 1.17 to 0.26 and 1.75 to 0.59, respectively (p<0.001). ConclusionManagement of paediatric chronic IF patients by an IRP with a vascular rehabilitation concept significantly lowers the rate of CLABSI episodes and the need for catheter replacements.

PITFALLS IN AUTOPSY TISSUE SAMPLING

Objective: To determine the pre-analytic factor which lead to autolysis in tissue sample thus hindering the establishment of histo-pathological cause of death in some autopsy tissue samples. Methods: Data collected from April, 2017 to September, 2018 (18 mo) at Department of Pathology, Dr. S. N. Medical College, Jodhpur. Results: The study, conducted over 18 mo from April 2017 to September 2018 at the Department of Pathology, Dr. S. N. Medical College, Jodhpur, analyzed 637 autopsy cases. These cases were predominantly from urban areas (70.17%), with a lesser number from rural regions (29.83%). A total of 698 tissue samples were received in various containers, with the majority (95.71%) preserved in formalin. The examination revealed that 38.4% of the samples were not autolysed, 36.1% were partially autolysed, and 25.5% were completely autolysed. The findings highlight a significant impact of the pre-analytic phase on tissue sample quality, notably the interval between death and autopsy, which was less than 24 h in 86.19% of cases, and the time from autopsy to histopathological examination, which ranged up to 1044 d. These factors were pivotal in the preservation status of the tissues, with formalin proving to be the most effective fixative in preventing autolysis, thus facilitating the accurate establishment of histopathological causes of death. Conclusion: If autopsy specimens are submitted for histopathological examination with proper protocol of transfer to fixative solution and transportation of tissue, this will help in determining the cause of death in majority of the autopsy specimens, therefore avoiding false negative results.

A comparative investigation of the effects of Resveratrol and dental pulp delivered mesenchimal stem cells on rat tibia bone defect healing

Resveratrol (3,4,5–trihydroxystilbene), an antioxidant compound, has a natural phytoalexin structure and also has many properties such as anti–inflammatory, antineoplastic and antiplatelet. In addition, mesenchymal stem cells isolated from various tissues are considered as a potential cell source for bone regenerative therapies. The present study aims to examine the effects of Resveratrol and dental pulp–derived mesenchymal stem cells on new bone formation in rats, both isolated and combined, by immunohistochemical methods. Twenty eigth Spraque Dawley male rats were used in the study. The rats were divided into four groups with seven rats in each group; the control group (Group 1) (n=7), the Systemic Resveratrol group (Group 2) (n=7), the Stem cell group (Group 3) (n=7), the Stem cell + Systemic Resveratrol group (Group 4) (n=7). A defect was opened on the tibia bones of the rats in all groups with a trephane bur (diameter of 3 mm and a length of 4 mm). After the 4–week experiment, all rats were sacrificed following the experimental protocols specific to each group. The specimens of tibia were subjected to histomorphological examination in fixative solutions. Values of inflammation, connective tissue formation, osteoclastic activity, osteoblast values, new bone formation, BMP2 and BMP4 expression levels obtained for all groups were evaluated by statistical analysis. Compared to the control group, new bone formation and osteoblastic activity were found to be significantly higher in the Stem cell group and Stem cell + Systemic Resveratrol group. (P=0.001) Additionally, new bone formation in the Systemic Resveratrol group was found to be significantly lower than in the Stem cell + Systemic Resveratrol group. (P=0.006) No significant difference was observed between other groups. (P&gt;0.05) According to the results of the study, it was observed that Stem cell + Resveratrol treatment was more effective than isolated Resveratrol or isolated stem cell treatment applications, it induced the development of more bone trabeculae, decrease inflammation and increased the number of osteoblasts involved in bone formation. In the light of these data, it was concluded that the combined use of Resveratrol and Stem cells is more effective on the healing of bone defects than their isolated use.

In vivo comparison of mesh fixation solutions in open and laparoscopic procedures for inguinal hernia repair: A meta-analysis

BackgroundAbdominal hernia repair surgeries involve the fixation of a surgical mesh to the abdominal wall with different means such as suture, tacks, and glues. Currently, the most effective mesh fixation system is still debated. This review compares outcomes of mesh fixation in different surgical procedures, aiding surgeons in identifying the optimal technique. MethodsA meta-analysis was conducted according to PRISMA guidelines. Articles published between January 2003 and January 2023 were searched in electronic databases. Randomized controlled trials (RCTs) comparing mesh fixation with cyanoacrylate-based or fibrin glues with classical fixation techniques (sutures, tacks) in open and laparoscopic procedures were included. Results17 RCTs were identified; the cumulative study population included 3919 patients and a total of 3976 inguinal hernias. Cyanoacrylate-based and fibrin glues were used in 1639 different defects, suture and tacks in 1912 defects, self-gripping mesh in 404 cases, and no mesh fixation in 21 defects. Glue fixation resulted in lower early postoperative pain, and chronic pain occurred less frequently. The incidence of hematoma was lower with glue fixation than with mechanical fixation. Recurrence rate, seroma formation, operative and hospitalization time showed no significant differences; but significantly, a higher number of people in the glue group returned to work by 15- and 30-days after surgery when compared to the tacker and suture groups in the same time frame. ConclusionCyanoacrylate and fibrin glue may be effective in reducing early and chronic pain and hematoma incidence without increasing the recurrence rate, the seroma formation, or the operative and hospitalization time.

Examining the effects of Lemongrass (Cymbopogon nardus) extract on Sperm Quality and Testosterone Level in Mice Induced with Staphylococcus aureus

There are a variety of causes for male infertility. Among them is microbial infection. Lemongrass (C. nardus) contains natural antioxidants and flavonoids that have the ability to preserve the male reproductive system. This study examined the effects of different C. nardus extract dosages on mouse sperm quality. The male Balb/C mice were separated into five groups of equal size. The negative control group was injected with 0.01ml of Na-CMC 0.5% over the course of 28 days, the positive control group was injected with 0.2ml of Staphylococcus aureus (S. aureus) on days 10, 17, and 24, and the treatment groups were injected with 0.2ml of S. aureus on days 10, 17, and 24, followed by 0.01ml of C. nardus. After the experiment, mice were slaughtered, and sperm suspension was obtained from the cauda epididymal to measure morphology, concentration, and motility. The testis was fixed in a fixative solution to analyze the spermatogenic cells, and intracardiac blood was drawn to determine the level of testosterone. Significant differences (p 0.05) were seen in the morphology, concentration, and motility of spermatozoa when C. nardus extract was administered. Given the low and middle concentrations of C. nardus extract, it can repair sperm damage caused by S. aureus infection.

Optimasi Pemisahan Perak dari Limbah Fixer melalui Variasi Tegangan

Fixer solution is a chemical substance in the form of a concentrated liquid that is used to wash radiographic films. The Fixer Solution functions to dissolve the silver halide layer on unexposed radiographic films. This research aims to design a waste fixer solution processing device using the electrolysis method and to regulate the voltage to the optimal point to produce a large electrolysis rate. Design an electrolysis device using stainless steel electrodes with a trapezoidal cathode with parallel sides of the cathode with lengths of 170 mm, 145 mm and a cathode height of 155 mm. The anode is rectangular with a length of 30 mm and a height of 169 mm. The method for making tools goes through several stages, namely making tool designs, testing tools, and testing waste fixer solution. The fixer waste used comes from Betesdha Wonosari Hospital. In this research, each test used 5 liters of fixer waste at each voltage which was regulated for 3 hours. The higher the mass voltage produced, the higher the electrolysis rate will be. However, the higher the voltage, the faster the sulfidation process will be. In the design of this fixer waste management tool, it can work optimally at a voltage of 4 V with a speed of 4.87 g/hour.

ATR-FTIR Spectroscopic Analysis of Novel Fixatives and their Histological Properties On Sheep Heart

Objective: In this study, new fixative solutions that are odorless and non-toxic were tested on the hearts of sheep to preserve the cellular structure and tissue architecture in a life-like manner. Material and Method: The changes of new fixatives before and after contact with tissue were detected for the first time by the ATR-FTIR spectroscopic method. After a preliminary inspection, hearts were fixed with six different solutions. It was periodically evaluated for weight, size, color, and hardness. Samples taken from the left vertical of each heart and stained with Hematoxylin eosin were observed histologically and alterations at the cellular level were evaluated. Results: As a result of the measurements of heart weights, reduction in Solution 1 (Standard Formaldehyde Fixative), Solution 4 and Solution 5 were detected at 5.64%, 23.70% and 14.38%, respectively. In Solution 4 and Solution 5, it was observed that the integrity of the myocardium was protected in terms of morphology, the stiffness was suited for sectioning and the coronary vessels were well preserved according to Solution 1. Further, compared to solution 1, it was determined that the endocardium and myocardium layers were well preserved in the tissues fixed in Solution 4 and Solution 5. Typical transversal streaking appearance in cardiac muscle tissue existed in all three Solution 1, Solution 4 and Solution 5. Conclusion: Solution 4 and Solution 5 were found to have superior fixative properties than Solution 1 (Formaldehyde). As a result of ATR-FTIR studies, it was determined that formaldehyde was converted into toxic formic acid in Standard Solution 1, while very few and harmless changes were detected in Solution 4 and Solution 5.

Changes of the bulbar conjunctiva as the result of glaucoma medication treatment

Aims/Purpose: To determine changes of the bulbar conjunctiva as the result of glaucoma medication treatment.Methods: We used an impression cytology method which implies the application of a cellulose acetate filter to the ocular surface, twice in the same place, to remove superficial layers of the nasal quadrant conjunctiva epithelium. The strips were removed after a few seconds of exposure, transferred into a fixative solution, followed by histological staining and light microscopy examination. The presence of squamous metaplasia was assessed using Nelson's scale, based on cells' morphology, staining behaviour, integrity and nucleoplasmic ratio. The case study included the first group of patients suffering from POAG and DED (80) (mean age = 63.8 ± 6.7 years) which was divided into 4 subgroups: 1 ‐ patients (40), who suffer from glaucoma for less than 5 years; 2 (40) ‐ more than 5 years; subgroup a (40) ‐ with one drug instilled, b (40) ‐ 2 or more drugs instilled. The second group consisted of almost healthy patients (mean age = 67.9 ± 8.9 years) All of them underwent general ophthalmological examination.Results: According to OSDI all glaucoma patients had dry eye symptoms (15 or more points). In subgroup 1 40% were diagnosed with Nelson I, 60% with Nelson II. In subgroup 2 15% had Nelson I, 55% had Nelson II and 30% had Nelson III. In subgroup a 20% of patients had Nelson I, 60% had Nelson II, and 20% were diagnosed with Nelson III. In subgroup b 30% had Nelson I, 60% had Nelson II, 10% of patients had Nelson III.Conclusions: 80% of cases show changes that correspond to II‐III Nelson degrees according to Nelson classification. The severity of metaplasia correlated with the duration of eye drops therapy, but not with the amount of them. According to the results that we received, and the international data, it is recommended to choose drugs without preservatives and other potentially toxic components for the long‐term treatment of glaucoma.

Gross, organoleptic and histologic assessment of cadaveric equine heads preserved using chemical methods for veterinary surgical teaching.

Preservation of biological tissues has been used since ancient times. Regardless of the method employed, tissue preservation is thought to be a vital step in veterinary surgery teaching and learning. This study was designed to determine the usability of chemically preserved cadaveric equine heads for surgical teaching in veterinary medicine. Six cadaveric equine heads were collected immediately after death or euthanasia and frozen until fixation. Fixation was achieved by using a hypertonic solution consisting of sodium chloride, sodium nitrite and sodium nitrate, and an alcoholic solution containing ethanol and glycerin. Chemically preserved specimens were stored at low temperatures (2°C to 6°C) in a conventional refrigerator. The specimens were submitted to gross and organoleptic assessment right after fixative solution injection (D0) and within 10, 20, and 30 days of fixation (D10, D20, and D30, respectively). Samples of tissue from skin, tongue, oral vestibule, and masseter muscle were collected for histological evaluation at the same time points. Physical and organoleptic assessments revealed excellent specimen quality (mean scores higher than 4 on a 5-point scale) in most cases. In some specimens, lower scores (3) were assigned to the range of mouth opening, particularly on D0 and D10. A reduced the range of mouth opening may be a limiting factor in teaching activities involving structures located in the oral cavity. The excellent physical, histologic, and organoleptic characteristics of the specimens in this sample support their usability in teaching within the time frame considered. Appropriate physical and organoleptic characteristics (color, texture, odor, and flexibility) of the specimens in this study support the use of the method described for preparation of reusable anatomical specimens.

Fixative Solution for Macromolecules in Histological Preparations

The fixation process is subjected to preserve cells, tissues, and their components so that the structure can be maintained as their alive condition and prevent autolysis. This literature review purpose to determine the appropriate use of fixative solutions for several macromolecules, such as proteins, lipids, carbohydrates, and nucleic acids. The literature review data is obtained form the secondary data included books, journals, or articles which discussed about fixative solutions without a limitation on the year of publication. The databases were sourced from Google Scholar, PubMed, NCBI, Science Direct, SpringerLink, Research Gate, and Nature. The keywords for the book search were tissue processing, pathology, and histology. Keywords for searching journals or articles were protein fixation, formaldehyde fixation lipids, fixatives for nucleic acids, Glyo-Fixx fixatives, mercury chloride fixative lipids, formalin-fixed carbohydrates, and ethanol or methanol for fixative lipids. Based on the literature review conducted, it can be concluded that the use of fixative solutions is according to the macromolecules to be observed.

Investigation of The Histopathological and Histometric Changes in Rectum Tissue Biopsies of Hirschsprung and Non-Hirschsprung Disease in Neonate and Infant

Hirschsprung disease is one of the most common and problematic infancy and childhood maladies. The most reliable method for diagnosis is the histopathological analysis of colorectal biopsies and the typical finding of Hirschsprung disease is the absence of ganglion cells. The study involved 36 cases of suspected Hirschsprung disease, in which 27 cases were males and 9 cases were females with an age range between (1 day - 1 year). All patients undergo complete history taking, physical examination, radiological investigations, and rectal biopsy. The tissue specimens were obtained from the rectum of neonate and infant patients, maintained in the fixative solution (formalin 10%) for histopathological analysis, and patients were divided into two groups (Hirschsprung disease and non-Hirschsprung disease group) according to histological findings. Statistical analysis was performed on the tabulated data by chi-square, and the automated computer-adopted image analysis program Image J® was utilized for the histometrical examination of rectum tissue. The Hirschsprung disease is more common in males than females. The delayed passage of meconium is the most common symptom of these diseases. We notice that there is a significant difference between the Hirschsprung disease group and the non-Hirschsprung disease group in clinical signs, empty rectum, tight anal sphincter on per rectal examination. Based on histopathology analysis of the rectal biopsy, out of the 36 cases, 27(75%) cases were diagnosed as Hirschsprung disease, and 9 (25%) cases as negative for Hirschsprung disease. In Histometric study of rectal biopsies tissues showed a significant difference in the mucosa, Submucosa, and muscularis externa between Hirschsprung disease and non-Hirschsprung disease patients.