Pathophysiology, Volume 31, Issue 3 (September 2024) – 14 articles

High systolic blood pressure and increased blood pressure variability after the onset of ischemic stroke are associated with poor clinical outcomes. One of the key determinants of blood pressure is arteriolar size, determined by vascular smooth muscle tone and vasodilatory and vasoconstrictor substances that are released by the endothelium. The aim of this study is to outline alterations in vasomotor function in isolated peripheral arteries following ischemic stroke. The reactivity of thoracic aortic segments from male C57BL/6 mice to dilators and constrictors was quantified using wire myography. Acetylcholine-induced endothelium-dependent vasodilation was impaired after ischemic stroke (LogIC50 Sham = −7.499, LogIC50 Stroke = −7.350, p = 0.0132, n = 19, 31 respectively). The vasodilatory responses to SNP were identical in the isolated aortas in the sham and stroke groups. Phenylephrine-induced vasoconstriction was impaired in the aortas isolated from the stroke animals in comparison to their sham treatment counterparts (Sham LogEC50= −6.652 vs. Stroke LogEC50 = −6.475, p < 0.001). Our study demonstrates that 24 h post-ischemic stroke, peripheral vascular responses are impaired in remote arteries. The aortas from the stroke animals exhibited reduced vasoconstrictor and endothelium-dependent vasodilator responses, while the endothelium-independent vasodilatory responses were preserved. Since both the vasodilatory and vasoconstrictor responses of peripheral arteries are impaired following ischemic stroke, our findings might explain increased blood pressure variability following ischemic stroke. Full article

Cathepsin S (CatS) is a proteolytic enzyme and a member of the cysteine protease family of proteolytic enzymes. Cathepsins S, K, and L are particularly similar in terms of their amino acid sequences and interactions with substrates, and this has made it difficult to develop inhibitors with specificity for either CatS, CatK, or CatL. The involvement of CatS in various disease pathophysiologies (autoimmune disorders, cardiovascular diseases, cancer, etc.) has made it a very important target in drug development. Efforts have been made since the early 1990s to develop a specific CatS inhibitor without any major success. Following many failed efforts to develop an inhibitor for CatS, it was discovered that interactions with the amino acid residues at the S2 and S3 pockets of CatS are critical for the identification of CatS-specific inhibitors. Amino acid residues at these pockets have been the target of recent research focused on developing a non-covalent, reversible, and specific CatS inhibitor. Methods applied in the identification of CatS inhibitors include molecular modeling, in-vitro screening, and in-vivo studies. The molecular modeling process has proven to be very successful in the identification of CatS-specific inhibitors, with R05459072 (Hoffmann-La Roche) and LY3000328 (Eli Lilly Company) which has completed phase 1 clinical trials. CatS inhibitors identified from 2011 to 2023 with promising prospects are discussed in this article. Full article

Wound healing is a complex dynamic biomechanical process as the body attempts to restore the integrity of traumatized or devitalized tissues. There are four stages of wound of healing that begins with hemostasis followed by inflammation, proliferation and finally weeks later wound remodeling. Full thickness wounds usually are covered with a dressing material after hemostasis, which allows for controlled hydration. We investigated the potential of a visco-liquid hemostat, polyhedral oligomeric silsesquioxane (POSS), for providing hemostasis and to maintain a microenvironment in the wound bed that would maintain moisture content and promote early re-epithelialization. We hypothesized that the hemostatic agent POSS if left in the wound bed would maintain a protective barrier and accelerate wound healing similar to using saline to irrigate the wound to keep the wound moist. We compared the early phase of wound repair (3–7 days) in a porcine full thickness wound model to evaluate the efficacy of the material. Biopsies were taken after 3 and 7 days to determine the acute response of the POSS hemostat or saline on inflammation, cell migration, concentrations of metalloproteinase (MMPs), and tissue inhibitors of metalloproteinase (TIMPs). Accelerated healing was observed in POSS treated wounds by changes in wound contraction, keratinocyte migration, and development of granulation tissue in comparison to saline treated wounds. Increased concentrations at day 3 of MMP-2, MMP-3, and in MMP-1 at day 7 in POSS treated wounds compared to saline coincide with keratinocyte migration observed in the tissue histology and changes in wound contraction. Tissue concentrations of TIMP-1 and TIMP-2 in POSS treated wounds appear to coordinate the sequence of MMP events in the healing tissue. Matrix metalloproteinase-13, a marker for tissue remodeling, was not upregulated in the early wound healing cascade in either POSS or saline treated wounds at 3 or 7 days. Overall, the data suggests POSS treatment contributed to enhanced early cell migration and wound closure compared to saline treatment. Full article

The assessment of endothelial dysfunction and free radical homeostasis parameters were performed in 92 women, aged 45 to 69 years, divided into the following groups: women without COVID-19 (unvaccinated, no antibodies, control); women with acute phase of COVID-19 infection (main group, COVID-19+); 12 months post COVID-19+; women with anti-SARS-CoV-2 IgG with no symptoms of COVID-19 in the last 12 months (asymptomatic COVID-19). Compared to the control, patients of the main group had lower glutathione peroxidase (GPx) and superoxide dismutase (SOD) activities, decreased advanced glycation end products (AGEs) level, higher glutathione reductase (GR) activity, and higher glutathione S transferases pi (GSTpi), thiobarbituric acid reactants (TBARs), endothelin (END)-1, and END-2 concentrations (all p ≤ 0.05). The group with asymptomatic COVID-19 had lower 8-OHdG and oxidized glutathione (GSSG) levels, decreased total antioxidant status (TAS), and higher reduced glutathione (GSH) and GSH/GSSG levels (all p ≤ 0.05). In the group COVID-19+, as compared to the group without clinical symptoms, we detected lower GPx and SOD activities, decreased AGEs concentration, a higher TAS, and greater GR activity and GSTpi and TBARs concentrations (all p ≤ 0.05). The high content of lipid peroxidation products 12 months post COVID-19+, despite decrease in ENDs, indicates long-term changes in free radical homeostasis. These data indicate increased levels of lipid peroxidation production contribute, in part, to the development of free radical related pathologies including long-term post COVID syndrome. Full article

Small GTP-binding proteins of the Rab family regulate intracellular vesicle trafficking across many aspects of the transport system. Among these, Rab9 is recognized for its role in controlling the transport system not only around the trans-Golgi network but also around the late endosome. However, the specific functions across different cell types and tissues remain unclear. Here, for the first time, we report that Rab9 negatively regulates morphological changes in the FBD-102b cell line, an oligodendroglial precursor cell line undergoing morphological differentiation. The knockdown of Rab9 led to an increase in cell shape alterations characterized by widespread membrane extensions. These changes were accompanied by increased expression levels of oligodendroglial cell differentiation and myelination marker proteins. Notably, the knockdown of Rab9 was capable of recovering defective cell morphological changes induced by tunicamycin, an inducer of endoplasmic reticulum (ER) stress, which is one of the major causes of oligodendroglial cell diseases such as Pelizaeus–Merzbacher disease (PMD, currently known as hypomyelinating leukodystrophy type 1 [HLD1]). In addition, Rab9 knockdown recovered levels of ER stress marker proteins and differentiation markers. Similar results were obtained in the cases of dithiothreitol (DTT), another chemical ER stress inducer, as well as HLD1-associated proteolipid protein 1 (PLP1) mutant protein. These results indicate a unique role for Rab9 in oligodendroglial cell morphological changes, suggesting its potential as a therapeutic target for mitigating diseases such as HLD1 at the molecular and cellular levels. Full article

The present study aims to evaluate the effect of Sepia pharaonis ink on insulin resistance in PCOS-induced mice. Treatment with sepia ink in dehydroepiandrosterone (DHEA)-induced PCOS mice at various doses of 50 mg/kg, 100 mg/kg, and 200 mg/kg body weight mitigated the insulin resistance in the study groups with decreased concentration of testosterone and increased concentrations of estrogen and progesterone compared to the PCOS group tested by ELISA. The histopathological analysis and restoration of glucose analysis showed a significant reduction in treatment groups. Reduced expression of insulin resistance genes like androgen receptor (AR), insulin receptor substrate 1 (IRS-1), and insulin-like growth factor1 (IGF-1) by qRT-PCR indicate a positive impact of sepia ink in alleviating the symptoms associated with PCOS. Taken together, the results of this study indicate sepia ink as a promising therapeutic intervention and a possible drug target for insulin resistance in diabetes and gynecological disorders like PCOS. Full article

Several studies have correlate improved patient outcomes with increased physician–patient contacts, particularly in chronic diseases. Extending this approach to inflammatory bowel disease (IBD) care presents a promising means of improving outcomes. At LSU Health Shreveport (LSUHS), a new approach called “STABILITY” (Symptomatic Review during Biologic Therapy) was implemented during infusion therapy visits for IBD patients. These brief 15 min physician–patient interviews aimed to discuss the patients’ current IBD-related symptoms and evaluate the need for any changes in their treatment plan. Our goal was to remove a care gap and prevent intensifying symptoms created by missed appointments and loss of contact. To analyze the effectiveness of the STABILITY approach, a retrospective chart review was conducted on 111 IBD patients (18 with ulcerative colitis, 93 with Crohn’s disease) seen at LSUHS between 2011 and 2022. Since March 2019, STABILITY has been mandatory for all infusion therapy visits. The data collected included patients’ demographics, lab levels for biomarkers (fecal calprotectin, C-reactive protein, and erythrocyte sedimentation rates), hospitalizations, medication changes, and diagnosis dates before and after the implementation of STABILITY. Additionally, voluntary, anonymous infusion patient satisfaction surveys post-STABILITY were used to gather patient responses. In males with IBD, disease severity and hospitalizations were reduced significantly (p = 0.004 and 0.0234, respectively). In females with IBD, disease severity and hospitalizations were also reduced significantly (p = 0.0001 and 0.0072, respectively). In patients with UC and CD, there were significant improvements in disease severity (p = 0.043 and p = 0.0001, respectively), and CD hospitalizations were also improved (p = 0.0013). In males and females with UC, disease severity was marginally and significantly reduced (p = 0.0781 and p = 0.0379, respectively). In males and females with CD, disease severity was significantly reduced (p = 0.0161 and 0.0003, respectively), and CD male and female hospitalizations were also reduced significantly (p = 0.0436 and 0.013). Analyzing of survey responses, we found that the most patients reported improved IBD symptoms (56%), gained understanding of their condition (84%) and were in favor of continuing STABILITY consultations during infusion therapy (93%). To further investigate the impact of STABILITY, we conducted a comparative analysis between IBD patients undergoing STABILITY infusion therapy and LSUHS patients solely on self-injectable biologics. Our paired data analysis showed significant improvements in disease severity in female IBD patients (1.69 ± 0.13 vs. 1.41 ± 0.12, p = 0.0001) and male IBD patients (1.58 ± 0.16 vs. 1.2 ± 0.135, p = 0.004), in UC patients (1.833 ± 0.4.2 vs. 1.444, p = 0.043), in all CD patients (1.59 ± 0.11 vs. 1.29 ± 0.01, p = 0.0001), in male CD patients (1.52 ± 0.167 vs. 1.15 ± 0.15, p = 0.016), in female CD patients (1.66 ± 0.15 vs. 1.4 ± 0.13, p = 0.0003), in female UC patients (1.82 ± 0.32 vs. 1.45 ± 0.31, p = 0.0379), and marginally in male UC patients (p = 0.0781). Similarly, hospitalizations were significantly reduced in CD patients considered in aggregate (0.21 ± 0.04 vs. 0.11 ± 0.03, p = 0.0013), in male IBD patients (0.175 ± 0.06 vs. 0.05 ± 0.035, p = 0.024), in female IBD patients (0.21 ± 0.05 vs. 0.11 ± 0.04, p = 0.0072), in male CD patients (0.18 ± 0.07 vs. 0.06 ± 0.042, p = 0.0436), and in females with CD (0.23 ± 0.06 vs. 0.13 ± 0.04, p = 0.013). Although average values for fecal calprotectin, CRP, and sedimentation rate were frequently reduced after STABILITY interviews, these data did not reach statistical significance. These preliminary findings suggest that STABILITY may be effective in maintaining low disease activity or remission in IBD patients. Full article

Background: Surgeons often encounter patients with intestinal failure due to inadequate intestinal length (“short bowel syndrome”/SBS). Treatment in these patients remains challenging and the process of physiologic adaptation may take years to complete, which frequently requires parenteral nutrition. We propose a proof-of-concept mechanical bowel elongation approach using a self-expanding prototype of an intestinal expansion sleeve (IES) for use in SBS to accelerate the adaptation process. Methods: IESs were deployed in the small intestines of Sprague Dawley rats. Mechanical characterization of these prototypes was performed. IES length–tension relationships and post-implant bowel expansion were measured ex vivo. Bowel histology before and after implantation was evaluated. Results: IES mechanical studies demonstrated decreasing expansive force with elongation. The deployment of IES devices produced an immediate 21 ± 8% increase in bowel length (p < 0.001, n = 11). Mechanical load testing data showed that the IESs expressed maximum expansive forces at 50% compression of the initial pre-contracted length. The small-intestine failure load in the rats was 1.88 ± 21 N. Intestinal histology post deployment of the IES showed significant expansive changes compared to unstretched bowel tissue. Conclusions: IES devices were scalable to the rat intestinal model in our study. The failure load of the rat small intestine was many times higher than the force exerted by the contraction of the IES. Histology demonstrated preservation of intestinal structure with some mucosal erosion. Future in vivo rat studies on distraction enterogenesis with this IES should help to define this organogenesis phenomenon. Full article

Background: Autism spectrum disorder (ASD) is one of the most prevalent neurodevelopmental disorders. Many patients with ASD often show behavioral problems at mealtimes, including food selectivity and atypical feeding behaviors. The Mediterranean diet (MD) has a beneficial effect on mental health for the general population across different ages. There is evidence that good adherence to the MD is effective in reducing peripheral inflammatory markers, such as the cytokine interleukin-6 (IL-6). The present study was designed to evaluate adherence to the MD in children with ASD using age- and sex-matched, typically developing individuals (TDs) as a control group and to determine whether differences in adherence to the MD are associated with salivary IL-6 and IL-6 receptor concentration. Methods: Twenty children and adolescents with ASD (mean age 9.95 ± 0.65 years) and twenty TDs (mean age: 9.85 ± 0.59 years) participated in this study (N = 16 males and N = 4 females in each group). Participants with ASD were enrolled in a psychiatric consultation in Valencia (Spain), and TDs were recruited from two public schools in Valencia. The parents of both ASD and TD groups answered the items in a validated Mediterranean Diet Quality Index for children and adolescents (KIDMED) questionnaire on their children’s adherence to the MD. Results: The mean adherence to MD score was significantly lower in the ASD group (9.10 ± 0.42) (range 6–12) than in the TD group (10.35 ± 0.31) (range 8–12) (p = 0.02, Mann–Whitney U test). There was no statistically significant association between adherence to the MD and age or sex in both groups, but there was a significant correlation between the total KIDMED score and body mass index (BMI) in the ASD group. Regarding the concentration of Il-6 and the Il-6 receptor in saliva samples, there were no significant differences between the two groups; however, linear regression analysis by group revealed significant associations between the adherence to MD score and the concentration of IL-6 and its receptor in saliva in the ASD group (p = 0.003, OR = 0.68, 95% CI 0.007 to −0.02; p = 0.009, OR = −0.64, 95% CI −0.01 to −0.00). In contrast, no significant associations were observed between the adherence to MD score and the concentration of IL-6 and its receptor in saliva in the TD group. Conclusions: Children and adolescents with ASD showed significantly lower adherence to the MD, which can contribute to nutritional deficits described in ASD, and the role of BMI composition (fat versus lean mass) needs to be further investigated in this group. The concentration of IL-6 and its receptor in saliva is associated with adherence to the MD, suggesting a possible link between IL-6 and diet in ASD. Further studies to clarify the associations between IL-6, psychiatric alterations, and diet in ASD are needed. Full article

Patients undergoing transurethral resection of the prostate (TURP) surgery can develop TURP syndrome and post-TURP bleeding. Post-TURP bleeding can be surgical, from arteries or venous sinuses, or non-surgical, due to coagulopathy preventing clot formation. Non-surgical post-TURP bleeding may be due to high concentrations of urokinase and tissue plasminogen activator (tPA) in the urine that cause fibrinolytic changes and increase bleeding risk. Urine urokinase and tPA may have both local and systemic fibrinolytic effects that may prevent blood clot formation locally at the site of surgery, and cause fibrinolytic changes systemically through leaking into the blood stream. Another post-TURP complication that may happen is TURP syndrome, due to absorption of hypotonic glycine fluid through the prostatic venous plexus. TURP syndrome may present with hyponatremia, bradycardia, and hypotension, which may be preceded by hypertension. In this case report, we had a patient with benign prostatic hyperplasia (BPH) who developed both TURP syndrome and non-surgical post-TURP bleeding. These complications were transient for one day after surgery. The local effect of urine urokinase and tPA explains the non-surgical bleeding after TURP by preventing clot formation and inducing bleeding. Coagulation studies showed fibrinolytic changes that may be explained by urokinase and tPA leakage into the blood stream. In conclusion, non-surgical bleeding after TURP can be explained by the presence of fibrinolytic agents in the urine, including urokinase and tPA. There is a deficiency in existing studies explaining the pathophysiology of the fibrinolytic changes and risk of bleeding after TURP. Herein, we discuss the possible pathophysiology of developing fibrinolytic changes after TURP. More research effort should be directed to explore this area to investigate the appropriate medications to treat and prevent post-TURP bleeding. We suggest monitoring patients’ coagulation profiles and electrolytes after TURP because of the risk of developing severe acute hyponatremia, TURP syndrome, fibrinolytic changes, and non-surgical bleeding. In our review of the literature, we discuss current clinical trials testing the use of an antifibrinolytic agent, Tranexamic acid, locally in the irrigation fluid or systemically to prevent post-TURP bleeding by antagonizing the fibrinolytic activity of urine urokinase and tPA. Full article

Obesity is a big public health problem that claims several thousand lives every year. Bariatric surgery has arisen as a suitable procedure for treating obesity, particularly morbid obesity. Oxidative stress, genotoxicity, apoptosis, and inflammatory responses are recognized as the most important occurrences in carcinogenesis, as they actively contribute to the multistep process. This study aimed to briefly review the connection between oxidative stress, genotoxicity, apoptosis, and inflammation in obese patients undergoing bariatric surgery, focusing on its impact on carcinogenesis. Regarding oxidative stress, bariatric surgery may inhibit the synthesis of reactive oxygen species. Moreover, a significant reduction in the inflammatory status after weight loss surgery was not observed. Bariatric surgery prevents apoptosis in several tissues, but the maintenance of low body weight for long periods is mandatory for mitigating DNA damage. In conclusion, the association between bariatric surgery and cancer risk is still premature. However, further studies are yet needed to elucidate the real association between bariatric surgery and a reduced risk of cancer. Full article

Background: Atrial fibrillation (AF) significantly contributes to acute ischemic stroke, with undetected AF being a common culprit in cryptogenic strokes. N-terminal pro-B-type natriuretic peptide (NT-proBNP), indicative of myocardial stress, has been proposed as a biomarker for AF detection, aiding in the selection of patients for extended cardiac monitoring. However, the diagnostic accuracy of NT-proBNP remains uncertain. Methods: We conducted a meta-analysis to evaluate the diagnostic accuracy of NT-proBNP in detecting AF among cryptogenic stroke patients. A comprehensive literature search was conducted across PubMed, Embase, and Cochrane databases to identify relevant studies. Studies reporting NT-proBNP levels in stroke patients and data on the proportion of patients with AF above a specified cut-off were included. Meta-analyses were performed using the midas command in STATA. Results: Seven studies encompassing 2171 patients were included in the analysis, of which five studies contained cohorts with cryptogenic strokes. Among patients with cryptogenic stroke, NT-proBNP demonstrated a diagnostic accuracy of 80% (Area Under the Receiver Operating Curve 0.80 [95% CI 0.76–0.83]), with a sensitivity of 81% (95% CI 0.68–0.89) and a specificity of 68% (95% CI 0.60–0.75). Conclusion: Our meta-analysis indicates that NT-proBNP exhibits a good-to-very-good diagnostic accuracy for detecting AF in patients with cryptogenic stroke. These findings suggest potential implications for utilizing NT-proBNP in guiding the selection of patients for prolonged cardiac monitoring, thereby aiding in the management of cryptogenic stroke cases. Full article

Understanding how gut flora interacts with oxidative stress has been the subject of significant research in recent years. There is much evidence demonstrating the existence of the microbiome–oxidative stress interaction. However, the biochemical basis of this interaction is still unclear. In this narrative review, possible pathways of the gut microbiota and oxidative stress interaction are presented, among which genetic underpinnings play an important role. Trimethylamine-N-oxide, mitochondria, short-chain fatty acids, and melatonin also appear to play roles. Moreover, the relationship between oxidative stress and the gut microbiome in obesity, metabolic syndrome, chronic ethanol consumption, dietary supplements, and medications is considered. An investigation of the correlation between bacterial community features and OS parameter changes under normal and pathological conditions might provide information for the determination of new research methods. Furthermore, such research could contribute to establishing a foundation for determining the linkers in the microbiome–OS association. Full article