Application of immunohistochemical staining to detect antigen destruction as a measure of tissue damage

Chondroprotective Effects of a Single PRP Injection in a Spontaneous Osteoarthritis Model of Dunkin Hartley Guinea Pig: An Immunohistochemical Analysis

Purpose of the Study

The evaluation of anti-apoptotic and chondroprotective properties of a single injection of PRP using immunohistochemistry (IHC).

Methods

This was a placebo-controlled blinded experimental study. Ten healthy Dunkin Hartley guinea pigs were selected. One knee of each animal was injected with a single injection of PRP (Group A); the contralateral knee acted as a control and was injected with a single injection of normal saline (Group B). These groups were further divided into A3 and B3 based on the timeline of animal sacrifice (3 months) and A6 and B6 (6 months). The formalin-preserved articular cartilage blocks were subjected to IHC to stain Aggrecan, Caspase-3, and Collagen-2.

Results

The mean IHC score was significantly low for Caspase-3 (p-0.029) in intervention group (A3) in comparison to placebo control group (B3) pointing towards decreased apoptosis. The mean IHC values were significantly higher for Collagen II (p-0.011) for intervention group (A6) in contrast to control group (B6); values were also significantly low for Caspase-3 (p-0.029) in A6 as compared to B6. The mean Caspase-3 values were significantly higher in A6 as compared to A3 (p-0.029).

Conclusion

The impact of a solitary injection of PRP on upregulation of anabolic pathways inside cartilage is relatively slower as compared to its effect on downregulation of apoptotic pathways. Even a single PRP injection holds the potential to change cartilage microenvironment, but the effects are not long lasting.

Review of immunohistochemistry techniques: Applications, current status, and future perspectives

The Hematoxylin and Eosin stain is a cornerstone in histopathology that facilitates the microscopic examination of tissue samples for identifying infections and tumors. However, challenges arise from the similar appearances of diseases and cells, prompting the emergence of Immunohistochemistry (IHC) as an important technique. This review summarizes the principles, procedures, and applications and future perspectives of IHC, a prevalent immunostaining method allowing the detection of specific proteins in tissue sections. The multistep IHC process involves fixation, embedding, sectioning, antigen retrieval, blocking, detection, counterstaining, mounting, and visualization, with interpretation relying on factors such as microanatomic distribution and staining intensity. Common errors in IHC such as non-specific staining, tissue artifacts, inadequately inactivation of endogenous peroxidase activity and cross-reactivity, can substantially affect the accuracy and reliability of results, thereby impacting the interpretation of biological findings. Serving diagnostic, prognostic, predictive, and therapeutic roles in various conditions, including tumors, infectious diseases, neurodegenerative disorders, and muscle diseases, IHC remains pivotal despite its intricate nature. The adoption of digital pathology emerges as a progressive enhancement, addressing limitations and ensuring more accurate analyses in histopathology.

The Defeathering Effect by Scalding in Chickens Follows Their Intrinsic Dermal Histologies

This study aimed to delineate the fundamental skin histology and its association with feathers in broilers and native Red-Feather (RF) chickens and further elucidate their thermal alterations in respect to the defeathering effect by scalding. Comparisons of skin thickness between fresh samples and those after dehydration and fixation, as well as their collagen contents and histological differences, suggested that RF chickens had a thicker dermal layer with more collagen deposition and compact architecture, particularly in the neck and abdominal skin, but a thinner hypodermal layer in the back, chest, and abdomen skin. Despite an adolescent age, RF chickens showed a shorter calamus depth of tail feathers but a larger calamus diameter of wing feathers. Within the feather follicle punch, a very intense follicle sheath layer with compact collagenous matrixes to fulfill the space next to the inner feather root sheath was observed in RF chickens. Under both soft and hard scalding, RF chickens showed a lower degree of denaturation on hip skins and were more resistant to structural disintegration, primarily within the epidermal and dermal layer. Accordingly, a much narrower gap space between the feather sheath and surrounding follicle sheath was observed, and the gap expansion was also resistant to thermal changes. These results suggest that the defeathering effect by scalding follows the intrinsic skin histologies in chickens of various breeds and ages, primarily depending on the interaction of the feather calamus with the surrounding follicle sheath and neighboring cutaneous tissues, reflecting their resistance to thermal denaturation, but is irrelevant to the feathers per se.

Assessing CB1 Expression in the Brain by Immunohistochemical Methods: Light, Confocal, and Electron Microscopy

Conventional techniques to reveal the neuroanatomical distribution of type 1 cannabinoid receptor (CB₁) in the brain, at the cellular and subcellular level, are mainly represented by light, confocal, and electron microscopy. By using immunoperoxidase and immunofluorescence methods, it is possible to reveal CB₁ distribution and localization in the brain and its changes under pathological conditions. Moreover, by using electron microscopy, we can define the ultrastructural localization at the level of subcellular structures and organelles. Here, we describe immunoperoxidase, immunofluorescence, and electron microscopy protocols used to get information about CB₁ spatial distribution and localization in the brain. Preparation of reagents, resin embedding, preparation for an endogenous activity-blocking step, and background counterstaining and revelation of CB₁ by using specific labeled secondary antibodies will be presented. The methods here discussed are highly sensitive and specific multistep processes, where each step is critical to finally obtain an optimum signal.

Study on the hypolipidemic effect of Inonotus obliquus polysaccharide in hyperlipidemia rats based on the regulation of intestinal flora

The purpose of this study was to observe the effect of Inonotus obliquus polysaccharide (IOP) on blood lipids and its regulation on the intestinal flora in hyperlipidemia rats, and explore the modern biological connotation of IOP in reducing blood lipids. In this study, we obtained the crude IOP by the water extraction and alcohol precipitation method, and then classified it by DEAE ion-exchange chromatography to obtain the acidic I. obliquus polysaccharide (IOP-A). After the administration of the IOP-A, the serum TC, TG, and LDL-C levels were significantly lower, while the serum HDL-C levels were significantly higher. The expression of CYP7A1 protein was considerably increased, whereas the expression of SREBP-1C protein was considerably decreased in the rat hepatic tissue. In addition, the IOP-A could significantly alleviate the hepatocyte fatty degeneration in the liver lobule of rats. We believe that the IOP-A can affect the composition of intestinal flora by reducing the relative abundance of Firmicutes and increasing the relative abundance of Bacteroidetes. These findings indicated that the IOP-A can regulate the dyslipidemia of hyperlipidemia rats, and its mechanism may be through regulating the CYP7A1 and SREBP-1C expression in the metabolism of lipids, and correcting the imbalance of intestinal flora structure caused by a high-fat diet.

Quantitative and qualitative analysis of pulmonary arterial hypertension fibrosis using wide-field second harmonic generation microscopy

We demonstrated that wide-field second harmonic generation (SHG) microscopy of lung tissue in combination with quantitative analysis of SHG images is a powerful tool for fast and label-free visualization of the fibrosis pathogenesis in pulmonary arterial hypertension (PAH). Statistical analysis of the SHG images revealed changes of the collagen content and morphology in the lung tissue during the monocrotaline-induced PAH progression in rats. First order statistics disclosed the dependence of the collagen overproduction on time, the second order statistics indicated tightening of collagen fiber network around blood vessels and their spreading into the alveolar region. Fourier analysis revealed that enhancement of the fiber orientation in the collagen network with PAH progression was followed with its subsequent reduction at the terminating phase of the disease. Proposed approach has potential for assessing pulmonary fibrosis in interstitial lung disease, after lung(s) transplantation, cancer, etc.

Chondroprotective effects of multiple PRP injections in osteoarthritis by apoptosis regulation and increased aggrecan synthesis- Immunohistochemistry based Guinea pig study

OBJECTIVE

Use of Immunohistochemistry as a tool to assess anti-apoptotic effects and cartilage regeneration effects of PRP in guinea pig model of spontaneous OA.

STUDY DESIGN

Controlled Laboratory Study involving Dunkin-Hartley guinea pigs.

METHODS

12 Dunkin-Hartley guinea pigs (weighing ∼600-800 g) were chosen for this study. One knee of each animal received 3 injections of allogenic PRP at weekly intervals (Group A = 12 Knees). The other knee received normal saline and acted as the control group (Group B = 12 Knees). Half of the animals from each group (subgroups A3 & B3 = 6 Knees each) were sacrificed at 3 months, and the remaining half (subgroups A6 & B6 = 6 Knees each) were sacrificed at 6 months after intervention. Immunohistochemistry (IHC) staining and evaluation were done for Collagen-II, Caspase-3 and Aggrecan.

RESULTS

The mean IHC score for Caspase-3 were significantly low in PRP knees compared to placebo Knees at 3 months (P = 0.031) and 6 months (P = 0.012) suggesting its down-regulation and inhibition of apoptosis. The mean IHC score for content of collagen- II and aggrecan at 3 months were higher in PRP Knees (A3) compared to placebo (B3) (Not significant). At 6 months, the Mean IHC Score decreased in both PRP (A6) and Control Knees (B6) for Collagen, but increased for aggrecan compared to its value at 3 months; and this was better in PRP group than in the control (P = 0.024).

CONCLUSION

Multiple injections of PRP has a chondroprotective role by its anti-apoptotic effect and by increasing the aggrecan content in ECM.

Comparative nephroprotective effects of curcumin and etoricoxib against cisplatin-induced acute kidney injury in rats

OBJECTIVE

Although cisplatin (CIS) acts as potent chemotherapy, nephrotoxicity still its major life-threatening side effect. The purpose of this study was to discuss and compare the renoprotective effects of curcumin (CUR) and etoricoxib (ETB) against CIS-induced nephrotoxicity.

MATERIALS & METHODS

Thirty six adult female rats were divided equally into 6 groups: Group I (control), Group II (CIS) received cisplatin (7.5 mg/kg i.p), Group III (CUR) and group IV (ETB) received curcumin (200 mg/kg/day) or etoricoxib (10 mg/kg/day) respectively via gavage for seven continuous days. Group V (CIS + CUR) and Group VI (CIS + ETB) received curcumin (200 mg/kg/day) or etoricoxib (10 mg/kg/day) via gavage for seven continuous days. On the 4th day, the rats received cisplatin (7.5 mg/kg i.p) as a single injection 1 h after last curcumin or etoricoxib administration. At the assigned time, blood and tissue samples were collected for biochemical, histochemical, histopathological, immunohistochemical, and RT-PCR gene expression studies.

RESULTS

Curcumin administration significantly decreased CIS-induced elevation of serum creatinine and blood urea nitrogen (BUN), and reversed oxidative stress markers; glutathione (GSH) and malondialdehyde (MDA) to control level. Suppression of inflammatory and apoptotic responses by CUR co-treatment was evidenced by decreased iNOS and BAX immunohistochemical reactions, and TNF-α and Caspase3 gene expressions which were detected by RT-PCR in kidney tissues. To our knowledge, this is the first time to discuss the effect of ETB on CIS induced nephrotoxicity. Although ETB reduced the previously mentioned inflammatory and apoptotic markers, its effect was less than that of CUR. Administration of ETB couldn't modify the disturbed levels of creatinine, BUN, GSH, and MDA.

CONCLUSION

In conclusion, CUR provided a promising renoprotective effect against CIS induced nephrotoxicity. Further studies are recommended to approve or disapprove the protective role of ETB in CIS induced nephrotoxicity.

Effect of cauterizing esophageal mucosa in "double-patch" treatment for acquired benign tracheoesophageal fistula/bronchogastric stump fistula

BACKGROUND

The management of acquired benign tracheoesophageal fistula (TEF) and bronchogastric stump fistula (BGSF) is a challenge. This study aimed to assess the "double-patch" technique with or without esophageal mucosa in treating nonmalignant TEF and BGSF.

MATERIALS AND METHODS

We established a dog model with TEF by incising the esophageal and tracheal membranes and suturing them together. The dogs were divided into three groups (n = 12 per group). Groups A and B received a double-patch 7 d later. The esophageal mucosa of the patches was cauterized in the group A dogs, kept intact in group B dogs, and group C dogs did not receive surgical intervention. Tissue healing was measured using hydroxyproline levels.

RESULTS

Morphologic and histopathologic changes of the esophagus were assessed by gross observation of the specimens, hematoxylin and eosin staining, tracheal stenosis index, and hydroxyproline levels. On day 56 after surgery, group A showed a tracheal stenosis index comparable with that of group C (0.140 ± 0.009 versus 0.138 ± 0.014, P = 1.00), whereas group B showed a higher stenosis index (0.170 ± 0.007) than group C (P = 0.029). The hydroxyproline levels were higher in group A than in B and C on day 7 (P = 0.029), and this difference was statistically significant on days 14 and 56 (all P < 0.001).

CONCLUSIONS

The use of an esophageal "double-patch" technique without mucosa showed faster and more stable recovery than patches with mucosa in the repair of acquired nonmalignant complicated TEF and BGSF.

Vincristine sulfate loaded dextran microspheres amalgamated with thermosensitive gel offered sustained release and enhanced cytotoxicity in THP-1, human leukemia cells: In vitro and in vivo study

Vincristine sulfate (VCS) is a drug of choice for the treatment of childhood and adult acute lymphocytic leukemia, Hodgkin's, non-Hodgkin's lymphoma as well as solid tumors including sarcomas. However, poor biopharmaceutical and pharmacokinetic traits of VCS like short serum half-life (12 min), high dosing frequency (1.4 mg/m(2) per week for 4 weeks) and extensive protein binding (75%) limit the clinical potential of VCS in cancer therapy. In present investigation, injectable vincristine sulfate loaded dextran microspheres (VCS-Dextran-MSs) were prepared and amalgamated with chitosan-β-glycerophosphate gel (VCS-Dextran-MSs-Gel) to surmount the biopharmaceutical and pharmacokinetic limitations of VCS that consequently induced synergistic sustained release pattern of the drug. Particle size and zeta-potential of VCS-Dextran-MSs were measured to be 6.8 ± 2.4 μm and -18.3 ± 0.11 mV along with the encapsulation efficiency of about 60.4 ± 4.5%. Furthermore, VCS-Dextran-MSs and VCS-Dextran-MSs-Gel exhibited slow release pattern and 94.7% and 95.8% of the drug was released in 72 h and 720 h, respectively. Results from cell viability assay and pharmacokinetic as well as histopathological analysis in mice indicated that VCS-Dextran-MSs-Gel offers superior therapeutic potential and higher AUClast than VCS-Dextran-MSs and drug solution. In conclusion, VCS-Dextran-MSs-Gel warrants further preclinical tumor growth study to scale up the technology.