Diabetic neuropathy--a review

Discovery of potential antidiabetic peptides using deep learning

Antidiabetic peptides (ADPs), peptides with potential antidiabetic activity, hold significant importance in the treatment and control of diabetes. Despite their therapeutic potential, the discovery and prediction of ADPs remain challenging due to limited data, the complex nature of peptide functions, and the expensive and time-consuming nature of traditional wet lab experiments. This study aims to address these challenges by exploring methods for the discovery and prediction of ADPs using advanced deep learning techniques. Specifically, we developed two models: a single-channel CNN and a three-channel neural network (CNN + RNN + Bi-LSTM). ADPs were primarily gathered from the BioDADPep database, alongside thousands of non-ADPs sourced from anticancer, antibacterial, and antiviral peptide datasets. Subsequently, data preprocessing was performed with the evolutionary scale model (ESM-2), followed by model training and evaluation through 10-fold cross-validation. Furthermore, this work collected a series of newly published ADPs as an independent test set through literature review, and found that the CNN model achieved the highest accuracy (90.48 %) in predicting the independent test set, surpassing existing ADP prediction tools. Finally, the application of the model was considered. SeqGAN was used to generate new candidate ADPs, followed by screening with the constructed CNN model. Selected peptides were then evaluated using physicochemical property prediction and structural forecasts for pharmaceutical potential. In summary, this study not only established robust ADP prediction models but also employed these models to screen a batch of potential ADPs, addressing a critical need in the field of peptide-based antidiabetic research.

Nigella sativa L. and its bioactive and nutraceutical components in the management of diabetic peripheral neuropathy

Diabetes-induced hyperglycemia leads to excessive production of oxygen free radicals, inflammatory cytokines, and oxidative stress, which initiates diabetic peripheral neuropathy (DPN). Currently, this condition affects 20% of adults with diabetes. Despite significant advances in the treatment of diabetes, the incidence of its complications, including DPN, is still high. Thus, there is a growing research interest in developing more effective and treatment approaches with less side effects for diabetes and its complications. Nigella sativa L. (NS) has received much research attention as an antioxidant, anti-yperglycemic factor, and anti-inflammatory agent. This natural compound demonstrates its antidiabetic neuropathy effect through various pathways, including the reduction of lipid peroxidation, the enhancement of catalase and superoxide dismutase enzyme activity, and the decrease in inflammatory cytokine levels. The present review focuses on the bioactive and nutraceutical components of black cumin (Nigella sativa L.) and their effects on DPN. In addition, we have also summarized the findings obtained from several experimental and clinical studies regarding the antidiabetic neuropathy effect of NS in animal models and human subjects.

SGLT2 inhibitors: a novel therapy for cognitive impairment via multifaceted effects on the nervous system

The rising prevalence of diabetes mellitus has casted a spotlight on one of its significant sequelae: cognitive impairment. Sodium-glucose cotransporter-2 (SGLT2) inhibitors, originally developed for diabetes management, are increasingly studied for their cognitive benefits. These benefits may include reduction of oxidative stress and neuroinflammation, decrease of amyloid burdens, enhancement of neuronal plasticity, and improved cerebral glucose utilization. The multifaceted effects and the relatively favorable side-effect profile of SGLT2 inhibitors render them a promising therapeutic candidate for cognitive disorders. Nonetheless, the application of SGLT2 inhibitors for cognitive impairment is not without its limitations, necessitating more comprehensive research to fully determine their therapeutic potential for cognitive treatment. In this review, we discuss the role of SGLT2 in neural function, elucidate the diabetes-cognition nexus, and synthesize current knowledge on the cognitive effects of SGLT2 inhibitors based on animal studies and clinical evidence. Research gaps are proposed to spur further investigation.

Biodegradable microspheres via orally deliver celastrol with ameliorated neuropathic pain in diabetes rats

The treatment of peripheral neuropathy resulting from diabetes primarily emphasizes neurotrophic medications. However, a growing body of clinical studies indicates that neuroinflammation plays a significant role in the pathogenesis of neuropathic pain. This has spurred active exploration of treatment strategies leveraging nanomedicine for diseases, aiming for superior therapeutic outcomes. In this context, we have developed biodegradable nanoparticles made of polylactic-co-glycolic acid, loaded with triptolide (pCel), designed to alleviate somatic cell neuropathic pain induced by diabetes. Treatment with pCel notably reduced levels of reactive oxygen species and apoptosis in vitro. Furthermore, the progression of streptozotocin-induced diabetes, characterized by elevated renal function indices (blood urea nitrogen, creatinine), liver function indices (bilirubin, alkaline phosphatase) and decreased levels of albumin and globulin, was mitigated following pCel administration. Importantly, oral treatment with pCel significantly inhibited mechanical allodynia and the activation of the sciatic glial cells in diabetic rats. These findings indicate that this synthetic, biodegradable nanomedicine exhibits excellent stability, biocompatibility and catalytic activity, making it a promising and innovative approach for the management of chronic pain conditions associated with diabetic neuropathy.

Age-dependent small fiber neuropathy: Mechanistic insights from animal models

Small fiber neuropathy (SFN) is a common and debilitating disease in which the terminals of small diameter sensory axons degenerate, producing sensory loss, and in many patients neuropathic pain. While a substantial number of cases are attributable to diabetes, almost 50% are idiopathic. An underappreciated aspect of the disease is its late onset in most patients. Animal models of human genetic mutations that produce SFN also display age-dependent phenotypes suggesting that aging is an important contributor to the risk of development of the disease. In this review we define how particular sensory neurons are affected in SFN and discuss how aging may drive the disease. We also evaluate how animal models of SFN can define disease mechanisms that will provide insight into early risk detection and suggest novel therapeutic interventions.

Phenotypical characterization of exteroceptive sensation and pain symptoms on diabetic patients

BACKGROUD

Diabetic neuropathy (DN) is one of the most common complications of diabetes, affecting about half of individuals with the disease. Among the various symptoms of DN, the development of chronic pain stands out and manifests as exacerbated responses to sensorial stimuli. The conventional clinical treatments used for general neuropathy and associated painful symptoms, still brings uncomplete and unsatisfactory pain relief. Patients with neuropathic pain syndromes are heterogeneous. They present with a variety of sensory symptoms and pain qualities which difficult the correct diagnosis of sensory comorbidities and consequently, the appropriate chronic pain management.

AIMS

Herein, we aimed to demonstrate the existence of different sensory profiles on diabetic patients by investigating epidemiological and clinical data on the symptomatology of a group of patients with DN.

METHODS

This is a longitudinal and observational study, with a sample of 57 volunteers diagnosed with diabetes from outpatient day clinic of Hospital Universitário of the University of São Paulo-Brazil. After being invited and signed the Informed Consent Form (ICF), patients were submitted to clinical evaluation and filled out pain and quality of life questionnaires. They also performed quantitative sensory test (QST) and underwent skin biopsy for correlation with cutaneous neuropathology.

RESULTS

Data demonstrate that 70% of the studied sample presented some type of pain, manifesting in a neuropathic or nociceptive way, what has a negative impact on the life of patients with DM. We also demonstrated a positive association between pain and anxiety and depression, in addition to pain catastrophic thoughts. Three distinct profiles were identified in the sample, separated according to the symptoms of pain: (i) subjects without pain; (ii) with mild or moderate pain; (iii) subjects with severe pain. We also identified through skin biopsy that diabetic patients presented advanced sensory impairment, as a consequence of the degeneration of the myelinated and unmyelinated peripheral fibers. This study characterized the painful symptoms and exteroceptive sensation profile in these diabetic patients, associated to a considerable level of sensory degeneration, indicating, and reinforcing the importance of the long-term clinical monitoring of individuals diagnosed with DM, regarding their symptom profiles and exteroceptive sensitivity.

Aging related obesity and type 2 diabetes mellitus suppress neuromuscular communication and aggravate skeletal muscle dysfunction in rhesus monkeys

Age-related functional deterioration in skeletal muscle raises the risk for falls, disability, and mortality in the elderly, particularly in obese people or those with type 2 diabetes mellitus (T2D). However, the response of the skeletal muscle to transitioning from obesity to diabetes remains poorly defined, despite that obesity is classified as a stage of pre-diabetes. We screened and selected spontaneously obese and diabetic rhesus monkeys and examined altered protein expression in skeletal muscle of healthy aging (CON), obesity aging (OB), and type 2 diabetes mellitus aging (T2D) rhesus monkeys using Tandem Mass Tags (TMT)-based quantitative proteomic analysis. In total, we identified 142 differentially expressed proteins. Muscle-nerve communication proteins were firstly suppressed at obese-stage. With the disintegration of skeletal muscle, mitochondrial complex I and other energy homeostasis relate proteins were significantly disordered at T2D stage. Indicating that aging related obesity suppressed muscle-nerve communication and contribute to T2D related functional deterioration of skeletal muscles in elderly rhesus monkeys. Some alterations of muscular functional regulator are detected in both obesity and T2D samples, suggesting some T2D related skeletal muscular hypofunctions are occurring at obesity or pre-obesity stage. Muscle-nerve communication proteins and muscular function related proteins could be potential therapy target or early diagnose marker of for skeletal muscular hypofunctions in aging obesity populations.

Evaluation of Serum Neurofilament Light Chain and Nerve Ultrasound in Diabetic Neuropathy

OBJECTIVE

To assess the role of serum neurofilament light chain (NfL) levels in individuals with diabetic polyneuropathy (DPN) compared with controls, as well as to highlight the different sonographic changes in DPN and determine if NfL correlates with sonographic, clinical, and functional parameters.

METHODS

Diabetic individuals with signs or symptoms consistent with peripheral nerve involvement were recruited. They were evaluated by examination, functional neuropathy severity scores, laboratory assessments (including NfL), nerve conduction studies (NCS), and ultrasound. Ultrasound was performed of the bilateral median, ulnar, tibial, fibular, sural, and vagus nerves, and cervical roots 5 and 6. Results were compared with age, sex, and body mass index matched healthy controls.

RESULTS

A total of 320 nerves from 20 patients and 480 nerves from 30 controls were evaluated. NfL was significantly elevated in those with diabetes with a mean and standard deviation of 6.95 ± 2.95 pg/mL in the diabetic group and 2.83 ± 0.77 pg/mL in controls (P < .001). Nerve cross-sectional area and serum NfL levels correlated significantly with clinical and functional parameters and with each other (P < .05).

CONCLUSION

Individuals with DPN have significantly higher NfL levels than healthy controls, and NfL levels correlate with ultrasonographic parameters. These findings may be useful for the diagnosis, prognosis, and disease monitoring of those with DPN, though further exploration is needed.

Skin neuropathy and immunomodulation in diseases

Skin is a vital barrier tissue of the body. Immune responses in the skin must be precisely controlled, which would otherwise cause severe disease conditions such as psoriasis, atopic dermatitis, or pathogenic infection. Research evidence has increasingly demonstrated the essential roles of neural innervations, i.e., sensory and sympathetic signals, in modulating skin immunity. Notably, neuropathic changes of such neural structures have been observed in skin disease conditions, implicating their direct involvement in various pathological processes. An in-depth understanding of the mechanism underlying skin neuropathy and its immunomodulatory effects could help reveal novel entry points for therapeutic interventions. Here, we summarize the neuroimmune interactions between neuropathic events and skin immunity, highlighting the current knowledge and future perspectives of this emerging research frontier.

Pramipexole protects against diabetic neuropathy: Effect on oxidative stress, TLR4/IRAK-1/TRAF-6/NF-κB and downstream inflammatory mediators

BACKGROUND

Diabetic neuropathy (DN) is a serious microvascular complication and a major cause of morbidity and mortality in diabetes mellitus. It is characterized by neurodegeneration of terminal sensory nerve fibers with subsequent pain, loss of sensation, and paresthesia, thus compromising the quality of life of diabetic patients. It is considered the leading cause of non-traumatic amputations worldwide, reflecting the insufficiency of current therapies. Pramipexole (PPX) is a dopamine receptor agonist used for the treatment of Parkinson's disease. The current study aims to investigate the potential neuroprotective effect of PPX in an experimental model of DN.

METHODS

Sprague Dawley rats were randomly assigned into five groups: normal control, Normal + PPX (1 mg/kg) group, STZ control, STZ + PPX (0.25 and 1 mg/kg/day for eight weeks). The neuroprotective effect of PPX in rats was evaluated in terms of sciatic nerve histological alterations, oxidative stress, and protein expression of TLR4/MyD88/IRAK-1/TRAF-6/NF-κB axis and downstream inflammatory mediators.

RESULTS

PPX administration ameliorated histopathological signs of neuronal inflammation and apoptosis. Additionally, PPX attenuated STZ-induced sciatic nerve oxidative stress and downregulated neural tissue expression of TLR4, MyD88, IRAK-1, TRAF-6, NF-κB and downstream mediators (TNF-α, IL-1β and ICAM-1).

CONCLUSION

Collectively, the current study sheds light on PPX as a potential protective medication to alleviate neuropathy progression in diabetic patients. PPX neuroprotective effect can be attributed to modulating TLR4/ MyD88/IRAK-1/TRAF-6/ NF-κB axis signaling in nerve tissues with subsequent attenuation of oxidative stress and inflammation.

4. Painful diabetic polyneuropathy

INTRODUCTION

Pain as a symptom of diabetic polyneuropathy (DPN) significantly lowers quality of life, increases mortality and is the main reason for patients with diabetes to seek medical attention. The number of people suffering from painful diabetic polyneuropathy (PDPN) has increased significantly over the past decades.

METHODS

The literature on the diagnosis and treatment of diabetic polyneuropathy was retrieved and summarized.

RESULTS

The etiology of PDPN is complex, with primary damage to peripheral nociceptors and altered spinal and supra-spinal modulation. To achieve better patient outcomes, the mode of diagnosis and treatment of PDPN evolves toward more precise pain-phenotyping and genotyping based on patient-specific characteristics, new diagnostic tools, and prior response to pharmacological treatments. According to the Toronto Diabetic Neuropathy Expert Group, a presumptive diagnosis of "probable PDPN" is sufficient to initiate treatment. Proper control of plasma glucose levels, and prevention of risk factors are essential in the treatment of PDPN. Mechanism-based pharmacological treatment should be initiated as early as possible. If symptomatic pharmacologic treatment fails, spinal cord stimulation (SCS) should be considered. In isolated cases, where symptomatic pharmacologic treatment and SCS are unsuccessful or cannot be used, sympathetic lumbar chain neurolysis and/or radiofrequency ablation (SLCN/SLCRF), dorsal root ganglion stimulation (DRGs) or posterior tibial nerve stimulation (PTNS) may be considered. However, it is recommended that these treatments be applied only in a study setting in a center of expertise.

CONCLUSIONS

The diagnosis of PDPN evolves toward pheno-and genotyping and treatment should be mechanism-based.

New Horizons in Diabetic Neuropathies: An Updated Review on their Pathology, Diagnosis, Mechanism, Screening Techniques, Pharmacological, and Future Approaches

BACKGROUND

One of the largest problems for global public health is diabetes mellitus (DM) and its micro and macrovascular consequences. Although prevention, diagnosis, and treatment have generally improved, its incidence is predicted to keep rising over the coming years. Due to the intricacy of the molecular mechanisms, which include inflammation, oxidative stress, and angiogenesis, among others, discovering treatments to stop or slow the course of diabetic complications is still a current unmet need.

METHODS

The pathogenesis and development of diabetic neuropathies may be explained by a wide variety of molecular pathways, hexosamine pathways, such as MAPK pathway, PARP pathway, oxidative stress pathway polyol (sorbitol) pathway, cyclooxygenase pathway, and lipoxygenase pathway. Although diabetic neuropathies can be treated symptomatically, there are limited options for treating the underlying cause.

RESULT

Various pathways and screening models involved in diabetic neuropathies are discussed, along with their possible outcomes. Moreover, both medicinal and non-medical approaches to therapy are also explored.

CONCLUSION

This study highlights the probable involvement of several processes and pathways in the establishment of diabetic neuropathies and presents in-depth knowledge of new therapeutic approaches intended to stop, delay, or reverse different types of diabetic complications.

Diabetic Neuropathy: An Overview of Molecular Pathways and Protective Mechanisms of Phytobioactives

Diabetic neuropathy (DN) is a common and debilitating complication of diabetes mellitus that affects the peripheral nerves and causes pain, numbness, and impaired function. The pathogenesis of DN involves multiple molecular mechanisms, such as oxidative stress, inflammation, and pathways of advanced glycation end products, polyol, hexosamine, and protein kinase C. Phytochemicals are natural compounds derived from plants that have various biological activities and therapeutic potential. Flavonoids, terpenes, alkaloids, stilbenes, and tannins are some of the phytochemicals that have been identified as having protective potential for diabetic neuropathy. These compounds can modulate various cellular pathways involved in the development and progression of neuropathy, including reducing oxidative stress and inflammation and promoting nerve growth and repair. In this review, the current evidence on the effects of phytochemicals on DN by focusing on five major classes, flavonoids, terpenes, alkaloids, stilbenes, and tannins, are summarized. This compilation also discusses the possible molecular targets of numerous pathways of DN that these phytochemicals modulate. These phytochemicals may offer a promising alternative or complementary approach to conventional drugs for DN management by modulating multiple pathological pathways and restoring nerve function.

In-silico, in-vitro and in-vivo Biological Activities of Flavonoids for the Management of Type 2 Diabetes

In spite of the fact that many medicinal plants have been truly utilized for the management of diabetes all through the world, very few of them have been reported scientifically. Recently, a diverse variety of animal models have been established to better understand the pathophysiology of diabetes mellitus, and new medications to treat the condition have been introduced in the market. Flavonoids are naturally occurring substances that can be found in plants and various foods and may have health benefits in the treatment of neuropathic pain. Flavonoids have also been shown to have an anti-inflammatory impact that is significant to neuropathic pain, as indicated by a decrease in several pro-inflammatory mediators such TNF-, NF-B IL-6, and IL-1. Flavonoids appear to be a viable novel therapy option for macrovasular complications in preclinical models; however, human clinical data is still inadequate. Recently, several in silico, in-vitro and in-vivo aproaches were made to evaluate mechanisms associated with the pathogenesis of diabetes in a better way. Screening of natural antidiabetic agents from plant sources can be analysed by utilizing advanced in-vitro techniques and animal models. Natural compounds, mostly derived from plants, have been studied in diabetes models generated by chemical agents in the majority of research. The aim of this work was to review the available in silico, in-vitro and animal models of diabetes for screening of natural antidiabetic agents. This review contributes to the scientist's design of new methodologies for the development of novel therapeutic agents having potential antihyperglycemic activity.

Mechanism of initiation and regulation of axonal degeneration with special reference to NMNATs and Sarm1

Axonal degeneration is observed in a variety of contexts in both the central and peripheral nervous systems. Pathological signaling to regulate the progression of axonal degeneration has long been studied using Wallerian degeneration, the prototypical axonal degradation observed after injury, as a representative model. Understanding metabolism of nicotinamide adenine dinucleotide (NAD+) and the functional regulation of Sarm1 has generated great progress in this field, but there are a number of remaining questions. Here, in this short review, we describe our current understanding of the axonal degeneration mechanism, with special reference to the biology related to wlds mice and Sarm1. Furthermore, variations of axonal degeneration initiation are discussed in order to address the remaining questions needed for mechanistic clarification.

Effectiveness of neuromuscular taping on balance, proprioception, pain, and nerve conduction parameters in patients with diabetic peripheral neuropathy: a two-group pretest-posttest randomized sham-controlled trial study protocol

Background

The management of diabetic peripheral neuropathy (DPN) comprises a multidimensional approach. Along with pharmacological treatment, physiotherapy has gained applaudable popularity in improving the symptoms of DPN. Neuromuscular taping (NMT) is effective in improving motor, sensory, and balance impairments in many neuromuscular and musculoskeletal conditions but no research has conducted to evaluate the effect of NMT on balance, proprioception, pain, and nerve conduction parameters in patients with DPN.

Purpose

To evaluate the effectiveness of NMT on balance, proprioception, pain, and nerve conduction parameters in patients with DPN.

Methods

50 DPN patients aged 40-60 years, scored ≥ 2/13 on physical appearance and ≥ 1/10 on physical examination of Michigan Neuropathy Screening Instrument (MNSI), > 12 on Leeds Assessment of Neuropathic Symptom and Sign (LANSS) scale and < 45 on Berg Balance Scale (BBS) will be included. The experimental group (EG) will receive NMT at the tibialis anterior, tibialis posterior, and peroneus longus muscle and transverse arch of the foot and TENS at the tibial and peroneal nerves (80 Hz, 50 Amp, 0.2 ms square pulses, 2 to 3 times sensory threshold) and the control group (CG) will receive sham taping at the ankle joint and TENS with the same parameters as EG. Outcome measures will be taken at baseline, at 4 weeks, and at 8 weeks of intervention, respectively.

Conclusion

The results obtained upon completion of this study may provide a cost-effective non-invasive treatment option to improve the outcomes that will be measured in the present study in patients with DPN.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40200-023-01275-5.

Effects of Neural Mobilization in Diabetic Peripheral Neuropathy: A Scoping Review

Objective

The purpose of this scoping review was to explore the effects of neural mobilization (NM) on outcomes in adults with diabetic peripheral neuropathy (DPN).

Methods

Five databases were searched-PubMed, Web of Science (Web of Science Core Collection), Physiotherapy Evidence Database (PEDro), and Scopus-from inception to January 2022. The studies included were randomized controlled trials, pre-post single group design, multiple case studies, controlled case studies, quasi-experimental studies, and single case studies, which are published in full text in English.

Results

Six studies were included in this review, and most were of low-level evidence. The sample size of the studies ranges from 20 to 43, except for 1 case study, with a total of 158 participants in all the studies combined. In 4 out of 6 studies, only NM was given, whereas in 2 studies, NM was used along with other treatment strategies. The tibial nerve was the most studied nerve, whereas 1 study administered NM to nerves of the upper limbs, and only 1 trial examined the sciatic nerve. The outcomes included the Michigan Neuropathy Screening Instrument questionnaire, nerve conduction velocity, vibration perception threshold, heat/cold perception threshold, weight-bearing asymmetry and range of motion of lower limb, quality of life, and magnetic imaging changes.

Conclusion

At present, only a few low-level studies exist on the use of NM for the treatment of adults with DPN. The evidence for use of NM on DPN is still limited and insufficient.

Oropharynx pain, discomfort, and economic impact of transesophageal echocardiography for planned radio-frequency catheter ablation in patients with atrial fibrillation: A cross-sectional survey study

Background

To survey the unmet medical needs associated with atrium thrombus screening in Chinese patients with atrial fibrillation (AF) who underwent transesophageal echocardiography (TEE) for planned radio-frequency catheter ablation (RFCA).

Methods

This cross-sectional survey study interviewed 300 patients who underwent their first TEE for planned RFCA. The surveyed information included patients' anxiety, oropharynx pain and discomfort, time expense, and patient satisfaction related to TEE examination. Patient preference for a new atrium thrombus screening technology, hospital length of stay (LOS) of RFCA, and hospital costs of RFCA in these surveyed patients were collected as well. Descriptive statistical methods were used to summarize the collected survey information.

Results

Of the 300 interviewed patients, 36.3% reported anxiety before TEE examination, 58.6% reported oropharynx pain related to TEE, and 76.2% reported oropharynx discomforts, mainly including foreign body sensation (54.3%), dry heaves (33.8%), nausea (31.9%), and bleeding (22.9%). Even though 62.3% were satisfied with TEE, 84.3% preferred a new technology to replace TEE. Conducting outpatient TEE took more wait time (4.4 days vs. 0.1 days, p = 0.016) but led to significantly shorter hospital LOS (3.8 days vs. 6.4 days, p < 0.001) and significant lower hospital costs for RFCA (¥74,097 vs. ¥85,843, p < 0.001) than conducting inpatient TEE.

Conclusions

Most AF patients experienced oropharynx pain and discomfort during or after TEE. Although more than half of AF patients were satisfied with TEE, most AF patients preferred a new technology to replace TEE for atrium thrombus screening. TEE was associated with economic impact on RFCA irrespective of TEE conducting settings.

Facial nerve neurographies in intensive care unit-acquired weakness

BACKGROUND

Patients with an intensive care unit-acquired weakness (ICU-AW) often present clinically with severe paresis of the limb and trunk muscles while facial muscles appear less affected. To investigate whether the facial nerves are partially spared from this condition, we performed both peripheral and cranial nerve conduction studies in critically ill patients.

METHODS

In patients requiring prolonged ICU therapy, the motor and sensory nerve conduction velocities of the peroneal, ulnar and facial nerves and the muscle action potentials of the associated muscles, as well as the orbicularis oculi reflexes were assessed shortly after admission, and on ICU days 7 and 14.

RESULTS

Eighteen patients were included in the final data analysis (average age 54.2 ± 16.8 years, 8 females). The amplitudes of the peroneal nerve compound muscle action potentials (CMAPs) were reduced in all patients at ICU days 7 and 14 (F(1.39; 23.63) = 13.85; p < 0.001). There was no similar decrease in the CMAP amplitudes of the ulnar or facial nerve. Other parameters of nerve function (latencies, sensory and motor nerve conduction velocities, sensory nerve action potentials) remained unchanged. The reproducibility of the orbicularis oculi reflex was reduced during the disease course, while its latencies did not change significantly during the disease course.

CONCLUSIONS

There is a relative preservation of CMAPs in facial and hand as opposed to foot muscles. This is compatible with the clinical observation that the facial muscles in patients with ICU-AW are less severely affected. This may be primarily a function of the nerve length, and consequently more robust trophic factors in shorter nerves. Trial registration This study was prospectively registered in the German Clinical Trial Register on April 20th 2020 (DRKS00021467).

Ocular motor nerve palsy in patients with diabetes: High-resolution MR imaging of nerve enhancement

OBJECTIVE

To evaluate the extent of signal abnormality in impaired ocular motor nerves using high signal and spatial resolution MRI sequences and to discuss the involvement of inflammatory or microvascular impairment in patients with diabetic ophthalmoplegia.

METHODS

We conducted a retrospective study of 10 patients referred for acute ocular motor nerve palsy in the context of diabetes mellitus from September 15th, 2021 to April 24th, 2022. 3T MRI evaluation included diffusion, 3D TOF, FLAIR, coronal STIR and post-injection 3D T1 SPACE DANTE sequences.

RESULTS

Ten patients were included: 9 males and 1 female aged from 46 to 79 years. Five patients presented with cranial nerve (CN) III palsy, and 5 presented with CN VI palsy. Third nerve palsy was pupil-sparing in 4 patients and pupil-involved in 1 patient. Pain was associated in all patients with CN III deficiencies and in 2 patients CN VI deficiencies. In all patients, MRI sequences ruled out mass effect and vascular pathology, such as acute stroke or aneurysm. Eight patients presented with STIR hypersignals, some with enlargement of the involved nerve. The diagnosis was confirmed through a post-injection 3D T1 SPACE DANTE sequence, which showed extended enhancement along the abnormal portion of the nerve.

CONCLUSION

High-resolution MRI evaluation of diplopia in diabetic patients is used to rule out a diagnosis of acute stroke and contributes to the positive diagnosis of ocular motor nerve impairment, possibly combining the influences of inflammatory and microvascular phenomena. Dedicated MR imaging should be included in the initial diagnosis and longitudinal follow-up of patients with diabetic ophthalmoplegia.

Establishment and validation of a nomogram for progression to diabetic foot ulcers in elderly diabetic patients

Background

Many diabetic patients develop and progress to diabetic foot ulcers, which seriously affect health and quality of life and cause great economic and psychological stress, especially in elderly diabetic patients who often have various underlying diseases, and the consequences of their progression to diabetic foot ulcers are more serious and seriously affect elderly patients in surgery. Therefore, it is particularly important to analyze the influencing factors related to the progression of elderly diabetic patients to diabetic foot, and the column line graph prediction model is drawn based on regression analysis to derive the influencing factors of the progression of elderly diabetic patients to diabetic foot, and the total score derived from the combination of various influencing factors can visually calculate the probability of the progression of elderly diabetic patients to diabetic foot.

Objective

The influencing factors of progression deterioration to diabetic foot in elderly diabetic patients based on LASSO regression analysis and logistics regression analysis, and the column line graph prediction model was established by statistically significant risk factors.

Methods

The clinical data of elderly diabetic patients aged 60 years or older in the orthopedic ward and endocrine ward of the Third Hospital of Shanxi Medical University from 2015-01-01 to 2021-12-31 were retrospectively analyzed and divided into a modeling population (211) and an internal validation population (88) according to the random assignment principle. Firstly, LASSO regression analysis was performed based on the modeling population to screen out the independent influencing factors for progression to diabetic foot in elderly diabetic patients; Logistics univariate and multifactor regressions were performed by the screened influencing factors, and then column line graph prediction models for progression to diabetic foot in elderly diabetic patients were made by these influencing factors, using ROC (subject working characteristic curve) and AUC (their area under the curve), C-index validation, and calibration curve to initially evaluate the model discrimination and calibration. Model validation was performed by the internal validation set, and the ROC curve, C-index and calibration curve were used to further evaluate the column line graph model performance. Finally, using DCA (decision curve analysis), we observed whether the model could be used better in clinical settings.

Results and conclusions

(1) LASSO (Least absolute shrinkage and selection operator) regression analysis yielded a more significant significance on risk factors for progression to diabetic foot in elderly diabetic patients, such as age, presence of peripheral neuropathy, history of smoking, duration of disease, serum lactate dehydrogenase, and high-density cholesterol; (2) Based on the influencing factors and existing theories, a column line graph prediction model for progression to diabetic foot in elderly diabetic patients was constructed. The working characteristic curves of subjects in the training group and their area under the curve (area under the curve = 0.840) were also analyzed simultaneously with the working characteristic curves of subjects in the external validation population and their area under the curve (area under the curve = 0.934), which finally showed that the model was effective in predicting column line graphs; (iii) the C-index in the modeled cohort was 0.840 (95%CI: 0.779-0.901) and the C-index in the validation cohort was 0.934 (95%CI: 0.887-0.981), indicating that the model had good predictive accuracy; the calibration curve fit was good; (iv) the results of the decision curve analysis showed that the model would have good results in clinical use; (v) it indicated that the established predictive model for predicting progression to diabetic foot in elderly diabetic patients had good test efficacy and helped clinically screen the possibility of progression to diabetic foot in elderly diabetic patients and give personalized interventions to different patients in time.

The Effects of a 10-Week Aerobic and Unilateral Lower Extremity Resistance Training Program on Amplitude and Nerve Conduction Velocity of Sensory and Motor Nerves in Diabetic Patients with Neuropathy

This study aimed to investigate the effects of 10-week aerobic and unilateral lower extremity resistance training on nerve conduction velocity and amplitude of sensory and motor nerves in diabetic patients with neuropathy. This clinical trial was conducted on twenty women and men (aged 30-60 years old) with diabetic neuropathy. Participants were randomly assigned to one of the two groups: an exercise group (EG; n = 10) and a control group (CG; n = 10). The EG performed a 10-week programme with one session of aerobic exercises (40% to 70% of HR reserve), supplemented with one session of specific lower extremity resistance exercises (60-90 min/day) on the same day for four days per week. The CG subjects performed their regular daily activities. The nerve conduction velocity, amplitude of sensory and motor nerves and glycosylated haemoglobin A1c were measured before and after the intervention. The repeated-measures ANOVA showed a significant increase in the conduction velocity of the sural sensory nerve as well as the peroneal motor nerve (p < 0.01, p < 0.01). The changes in the conduction velocity of the tibial nerve were similar when compared to the control group (p > 0.05). A significantly greater decrease in glycosylated haemoglobin was also observed in the EG group (p < 0.01). Performing 10 weeks of aerobic and specific unilateral lower extremity exercises can improve the function of sensory and motor nerves and improve symptoms in diabetic patients with neuropathy. Given the limited studies in this area, the exact mechanisms of this performance improvement need further examination.

Time of onset and factors associated with delayed response post intradetrusor injection of onabotulinumtoxin a in patients with neurogenic and idiopathic overactive bladder syndrome

Objective

The objective of this study was to determine risk factors for delayed response in patients with neurogenic and idiopathic overactive bladder (OAB) after intradetrusor onabotulinumtoxin A injection.

Subjects and Methods

This is a retrospective study that included 87 patients who underwent onabotulinumtoxin A intradetrusor injection from October 2011 to November 2019. Patients were followed up at 2, 4, and 12 weeks post intervention in the outpatient clinic and over the phone. The data of patients with early response were compared with those with late response using univariate and multivariate analyses.

Results

The study included 87 patients. The mean age was 41 ± 15.3 standard deviation, and 69% of the participants were female. Fifty-one percent were diagnosed with neurogenic OAB. A median response time to onabotulinumtoxin A injection of 7 days was demonstrated, and patients who responded during the first 7 days post procedure were considered early responders. Independent predictors for late response include diabetes (Relative risk: 3.89, P = 0.018, and 95% confidence interval [CI]: 1.26-11.98), >1 BTX-A session (Relative risk: 4, P = 0.011, and 95% CI: 1.38-11.6), and wet OAB (RR: 9.94, P = 0.002, and 95% CI: 2.31-42.17).

Conclusions

The median time of onset post intradetrusor injection of onabotulinumtoxin A was found to be 7 days. Diabetes mellitus, wet OAB, and <1 Botox sessions were independent risk factors for late onset of response.

Chronic pain in Chile: first prevalence report of noncancer chronic pain, fibromyalgia, and neuropathic pain and its associated factors

ABSTRACT

Although we know chronic pain (CP) affects approximately 30% of people in developed countries, data from Latin America are scarce. Moreover, prevalence of specific CP conditions, such as chronic noncancer pain (CNCP), fibromyalgia (FM), and neuropathic pain (NP), is unknown. To estimate them in Chile, we prospectively enrolled 1945 participants (61.4% women and 38.6% men), aged 38 to 74 years, from an agricultural town who answered a Pain Questionnaire, the Fibromyalgia Survey Questionnaire, and Douleur Neuropathique 4 (DN4) to identify CNCP, FM, and NP, respectively. The estimated prevalence of CNCP was 34.7% (95% CI 32.6; 36.8), with an average duration of 32.3 months (SD ± 56.3), producing deep impairments in daily activities, sleep, and mood. We estimated a prevalence of 3.3% for FM (95% CI 2.5; 4.1) and 12% for NP (95% CI 10.6; 13.4). Female sex, fewer school years, and depressive symptoms were associated with FM and NP, whereas diabetes was only associated with NP. We standardized the results from our sample against the whole Chilean population and found no significant difference to our crude estimates. This is in line with studies from developed countries, highlighting the idea that despite genetic and environmental differences, the conditions that confer risk to CNCP remain stable.

Metabolic and lifestyle risk factors for chemotherapy-induced peripheral neuropathy in taxane and platinum-treated patients: a systematic review

PURPOSE

Chemotherapy-induced peripheral neurotoxicity (CIPN) is a common dose-limiting toxicity of cancer treatment causing functional impairment and impacting quality of life. Effective prevention and treatment of CIPN are lacking, and CIPN risk factors remain ill-defined. Metabolic syndrome and associated conditions have emerged as potential risk factors, due to their high prevalence and independent association with nerve dysfunction. This systematic review aimed to investigate the association between these common metabolic-lifestyle factors and CIPN.

METHODS

Searches were undertaken using Medline, Embase, CINAHL, Scopus, and Web of Science databases, with additional studies identified from bibliographic references cited by original and review articles. Articles that analyzed metabolic-lifestyle risk factors associated with CIPN for patients treated with platinum- or taxane-based chemotherapy were included.

RESULTS

Searches identified 6897 titles; 44 articles had full text review, with 26 studies included. Overall incidence of neuropathy ranged from 16.9 to 89.4%. Obesity had the most consistent patient-oriented evidence as a risk factor for CIPN, with moderate evidence suggesting diabetes did not increase CIPN incidence or severity. A limited number of studies supported an association with low physical activity and greater CIPN risk.

CONCLUSIONS

Comorbidities and lifestyle factors, particularly obesity and low physical activity, may contribute to the development of CIPN. The implementation of sensitive outcome measures in large-scale clinical trials is required to further elucidate CIPN risk factors and evaluate if changes in lifestyle would improve long-term CIPN outcomes for cancer survivors.

IMPLICATIONS FOR CANCER SURVIVORS

Better understanding of CIPN risk profiles may inform personalized medicine strategies and help elucidate pathophysiological mechanisms which could be targeted for neuroprotection.

The receptor for advanced glycation end products and its ligands' expression in OVE26 diabetic sciatic nerve during the development of length-dependent neuropathy

Type 1 diabetes (T1D) may affect the peripheral nervous system and alter the expression of proteins contributing to inflammation and cellular cytoskeleton dysfunction, in most cases leading to the development of diabetic length-dependent neuropathy (DLDN). In the present study, we performed immunohistochemistry (IHC) to probe the expression of the receptor for advanced glycation end products (RAGE); its key ligands, high-mobility group box 1 (HMGB1), S100 calcium-binding protein B (S100B), and carboxymethyl-lysine (CML - advanced glycation end products (AGE)); and its cytoplasmic tail-binding partner, diaphanous related formin 1 (DIAPH1) and associated molecules, beta-actin (ACTB) and profilin 1 (PFN1) proteins in sciatic nerves harvested from seven-month old FVB/OVE26 mice with genetically-mediated T1D. We found that the amount of RAGE, HMGB1, and S100B proteins was elevated in diabetic vs the non-diabetic groups, while the amount of DIAPH1, ACTB, as well as PFN1 proteins did not differ between these groups. Moreover, our data revealed linear dependence between RAGE and HMGB1 proteins. Interaction criss-cross of selected sets of proteins in the sciatic nerve revealed that there were connected in a singular network. Our results indicate that T1D may alter expression patterns of RAGE axis proteins and thus contribute to DLDN.

Effects of 1-methyl-1, 2, 3, 4-tetrahydroisoquinoline on a diabetic neuropathic pain model

Background: Neuropathy is a prevalent and debilitating complication of poorly managed diabetes, contributing towards poor quality of life, amputation risk, and increased mortality. The available therapies for diabetic neuropathic pain (DPN) have limitations in terms of efficacy, tolerability and patient compliance. Dysfunction in the peripheral and central monoaminergic system has been evidenced in various types of neuropathic and acute pain. The objective of the present study was to investigate 1-methyl 1, 2, 3, 4-tetrahydroisoquinoline (1MeTIQ), an endogenous amine found in human brain with a known neuroprotective profile, in a model of streptozotocin (STZ) induced neuropathic pain. Methods: Diabetic neuropathy in male BALB/c mice was induced by intraperitoneal injection of a single dose of STZ (200 mg/kg). Upon development of DPN after 4 weeks, mice were investigated for mechanical allodynia (von Frey filament pressure test) and thermal hyperalgesia (tail immersion test). Ondansetron (1.0 mg/kg i.p.), naloxone (3.0 mg/kg i.p.) and yohimbine (2.0 mg/kg i.p.) were used to elucidate the possible mechanism involved. Postmortem frontal cortical, striatal and hippocampal tissues were dissected and evaluated for changes in levels of dopamine, noradrenaline and serotonin using High-Performance Liquid Chromatography (HPLC) with UV detection. Results: Acute administration of 1MeTIQ (15-45 mg/kg i.p.) reversed streptozotocin-induced diabetic neuropathic static mechanical allodynia (von Frey filament pressure test) and thermal hyperalgesia (tail immersion test), these outcomes being comparable to standard gabapentin. Furthermore, HPLC analysis revealed that STZ-diabetic mice expressed lower concentrations of serotonin in all three brain regions examined, while dopamine was diminished in the striatum and 1MeTIQ reversed all these neurotransmitter modifications. These findings suggest that the antihyperalgesic/antiallodynic activity of 1MeTIQ may be mediated in part via supraspinal opioidergic and monoaminergic modulation since they were naloxone, yohimbine and ondansetron reversible. Conclusion: It was also concluded that acute treatment with 1MeTIQ ameliorated STZ-induced mechanical allodynia and thermal hyperalgesia and restored brain regionally altered serotonin and dopamine concentrations which signify a potential for 1MeTIQ in the management of DPN.

Nerve conduction velocity is independently associated with bone mineral density in type 2 diabetes mellitus

AIM

This study investigated the association between nerve conduction velocity (NCV) and bone mineral density (BMD) in patients with type 2 diabetes mellitus (T2DM).

METHODS

This study retrospectively collected medical data of T2DM patients who underwent dual-energy X-ray absorptiometry and nerve conduction study at the Shanghai Ruijin Hospital, Shanghai, China. The primary outcome was the total hip BMD T-score. The main independent variables were motor nerve conduction velocities (MCVs), sensory nerve conduction velocities (SCVs), and composite Z-scores of MCV and SCV. T2DM patients were divided into total hip BMD T-scores < -1 and total hip BMD T-scores ≥ -1 groups. The association between the primary outcome and main independent variables was evaluated by Pearson bivariate correlation and multivariate linear regression.

RESULTS

195 female and 415 male patients with T2DM were identified. In male patients with T2DM, bilateral ulnar, median, and tibial MCVs and bilateral sural SCVs were lower in the total hip BMD T-score < -1 group than T-score ≥ -1 group (P < 0.05). Bilateral ulnar, median, and tibial MCVs, and bilateral sural SCVs showed positive correlations with total hip BMD T-score in male patients with T2DM (P < 0.05). Bilateral ulnar and tibial MCVs, bilateral sural SCVs, and composite MCV SCV and MSCV Z-scores were independently and positively associated with total hip BMD T-score in male patients with T2DM, respectively (P < 0.05). NCV did not show significant correlation with the total hip BMD T-score in female patients with T2DM.

CONCLUSION

NCV showed positive association with total hip BMD in male patients with T2DM. A decline in NCV indicates an elevated risk of low BMD (osteopenia/osteoporosis) in male patients with T2DM.

Multi-omics analysis revealed the role of CYP1A2 in the induction of mechanical allodynia in type 1 diabetes

Background: Mechanical allodynia (MA) is one of the leading clinical symptoms of painful diabetic peripheral neuropathy (PDPN), which is a primary reason for non-traumatic amputations, foot ulceration, and gait abnormalities in patients with diabetes. However, the pathogenic mechanisms of MA have not yet been fully elucidated, and there is no effective treatment. This study aims to study the potential pathogenetic mechanisms of MA and to provide targets for the therapy of MA. Methods: A single intraperitoneal injection of streptozotocin induced type 1 diabetes in rat models. Subsequently, rats were divided into the control group, the diabetic group without MA, and the diabetic group with MA based on weekly behavioral assays. The differentially expressed lipids in the sciatic nerve of each group were detected using untargeted lipidomics, and the differentially expressed genes in the sciatic nerve of each group were detected by transcriptomics. The pathogenesis of MA was predicted using integrated analysis and validated by immunofluorescence staining and transmission electron microscopy. Results: Untargeted lipidomics revealed the accumulation of a more severe lipid in MA rats. Transcriptomics results suggested that differentially expressed genes in MA rats were primarily related to lipid droplets and myelin sheath. Integrated analysis results indicated that the downregulation of Cytochrome P450 1A2 (CYP1A2) expression was closely linked to lipid metabolism disorders. Immunofluorescence staining demonstrated that down-regulation of CYP1A2 expression occurred in MA rats. Transmission electron microscopy results showed that more severe lipid droplet accumulation and myelin sheath degeneration occurred in MA rats. Conclusion: Our findings imply that the downregulation of CYP1A2 expression leads to disorders of lipid metabolism and further leads to lipid droplet accumulation and myelin sheath degeneration, which might ultimately lead to the development of MA. Therefore, our study contributes to promoting the understanding of the molecular mechanisms of MA and providing potential targets for the clinical treatment of MA.

Pulsed magnetic field treatment ameliorates the progression of peripheral neuropathy by modulating the neuronal oxidative stress, apoptosis and angiogenesis in a rat model of experimental diabetes

OBJECTIVE

The present study aimed to investigate the possible anti-neuropathic effects of daily pulsed magnetic field treatments (PMF) in streptozotocin (60 mg/kg) induced 4 weeks diabetic (type-1) wistar rats (6-8 months).

MATERIALS AND METHODS

Body mass, blood glucose and thermal and mechanical sensations were evaluated during the PMF or sham-PMF in diabetic or non-diabetic rats (n = 7/group). After the measurements of motor nerve conduction velocities (MNCV), the levels of several biomarkers for oxidative stress, apoptosis and angiogenesis in spinal cord and sciatic nerve were measured.

RESULTS

PMF for 4 weeks significantly recovered the MCNV (96.9% and 63.9%) and almost fully (100%) restored to the latency and threshold. PMF also significantly suppressed the diabetes induced enhances in biochemical markers of both neuronal tissues.

CONCLUSIONS

Findings suggested that PMF might prevent the development of functional abnormalities in diabetic rats due to its anti-oxidative, anti-apoptotic and anti-angiogenic actions in neuronal tissues.

Residual one-dimensional convolutional neural network for neuromuscular disorder classification from needle electromyography signals with explainability

BACKGROUND AND OBJECTIVE

Neuromuscular disorders are diseases that damage our ability to control body movements. Needle electromyography (nEMG) is often used to diagnose neuromuscular disorders, which is an electrophysiological test measuring electric signals generated from a muscle using an invasive needle. Characteristics of nEMG signals are manually analyzed by an electromyographer to diagnose the types of neuromuscular disorders, and this process is highly dependent on the subjective experience of the electromyographer. Contemporary computer-aided methods utilized deep learning image classification models to classify nEMG signals which are not optimized for classifying signals. Additionally, model explainability was not addressed which is crucial in medical applications. This study aims to improve prediction accuracy, inference time, and explain model predictions in nEMG neuromuscular disorder classification.

METHODS

This study introduces the nEMGNet, a one-dimensional convolutional neural network with residual connections designed to extract features from raw signals with higher accuracy and faster speed compared to image classification models from previous works. Next, the divide-and-vote (DiVote) algorithm was designed to integrate each subject's heterogeneous nEMG signal data structures and to utilize muscle subtype information for higher accuracy. Finally, feature visualization was used to identify the causality of nEMGNet diagnosis predictions, to ensure that nEMGNet made predictions on valid features, not artifacts.

RESULTS

The proposed method was tested using 376 nEMG signals measured from 57 subjects between June 2015 to July 2020 in Seoul National University Hospital. The results from the three-class classification task demonstrated that nEMGNet's prediction accuracy of nEMG signal segments was 62.35%, and the subject diagnosis prediction accuracy of nEMGNet and the DiVote algorithm was 83.69 %, over 5-fold cross-validation. nEMGNet outperformed all models from previous works on nEMG diagnosis classification, and heuristic analysis of feature visualization results indicate that nEMGNet learned relevant nEMG signal characteristics.

CONCLUSIONS

This study introduced nEMGNet and DiVote algorithm which demonstrated fast and accurate performance in predicting neuromuscular disorders based on nEMG signals. The proposed method may be applied in medicine to support real-time electrophysiologic diagnosis.

Investigation of Natural Compounds for Therapeutic Potential in Streptozotocin-induced Diabetic Neuroinflammation and Neuropathic Pain

Diabetic neuropathy (DN) is a serious microvascular complication of diabetes mellitus (DM) that impacts the nervous system. Several risk factors are involved in the progression and maintenance of DN-associated pain, such as higher expression of various inflammatory mediators, e.g., tumor necrotic factor-alpha (TNF-α), nuclear factor-kappa B (NF-κB), and cyclo-oxygenase-2 (COX-2). The present research explores the neuroprotective potential of natural isolates, including berbamine, bergapten, and carveol, on the DM-induced neuroinflammation and neurodegeneration that cause neuropathic pain. The study utilized computerized techniques, including computational analysis (a docking assay and a molecular dynamic simulation) before moving to in vivo protocols. Diabetic neuropathy was induced by intraperitonial injection (IP) of streptozotocin (65 mg/kg), and the animal subjects (rats) were kept for 4 weeks for the development of DN. Once diabetic neuropathy was confirmed, the subjects were treated with berbamine, bergapten, and carveol until the sixth week (i.e., 2 weeks of treatment). At the sixth week, the rats were sacrificed, and the sciatic nerve and spinal cord of each was collected for further molecular investigation. Docking and a molecular dynamic simulation (MDS) delivered the information that the natural compounds (berbamine, bergapten, and carveol) were interacting with the selected target protein (i.e., mitogen-activated protein kinase). After IP, it was found that berbamine, bergapten, and carveol had ameliorated mechanical allodynia and thermal hyperalgesia by the 28th day of the study (2 weeks after treatment) without affecting blood glucose levels. Berbamine, bergapten, and carveol markedly elevated the levels of glutathione (GSH) and glutathione s-transferase (GST), in both the sciatic nerve and spinal cord, and also reduced lipid peroxidase (LPO) and nitric oxide (NO). The abovementioned natural isolates reduced pathologic alterations provoked through DN, a finding confirmed through histopathological assays (hematoxylin and eosin staining and immuno-histochemical analysis). Treatment down regulated higher expressions of the inflammatory mediatorcyclooxygenase-2 (COX-2), tumor necrosis factor-α (TNF-α), and nuclear factor kappa B (NF-κB), as confirmed by ELISA and polymerase chain reaction (PCR). The outcomes of berbamine, bergapten, and carveol are compared with those of pregabalin as a positive control group. Compared to pregabalin, treatment with the aforementioned three natural compounds improved nociception and reduced hyperalgesic effects, and consequently reduced pain perception and inflammation. Our results suggest the mechanism for the neuro-protective impact of berbamine, bergapten, and carveol might possibly be arbitrated via COX-2, TNF-α, and NF-κB, and regulated by mitogen-activated protein kinase, ultimately ameliorating STZ-provoked, DM-induced neuroinflammation and neurodegeneration, and associated neuropathic pain.

Association of peripheral neuropathy with skeletal muscle mass and function in type two diabetes mellitus patients: A cross-sectional study

BACKGROUND & OBJECTIVE

Diabetic peripheral neuropathy (DPN) is considered to be a risk factor for development of sarcopenia. Therefore, our study aimed to detect the association between peripheral neuropathy with skeletal muscle mass and function in type two diabetes mellitus (T2DM) patients.

METHODS

A total of 176 participants, ≥45 years were included in the study. Out of 176, 60 were healthy volunteers, 60 had T2DM without neuropathy, 56 had T2DM with neuropathy. In all the participants peripheral nerve function was assessed by nerve conduction studies (Common peroneal and Sural nerve) and sarcopenia parameters were evaluated according to the Asian Working Group for Sarcopenia (AWGS) criteria.

RESULTS

The present study suggested that diabetic peripheral neuropathy (DPN) was associated with decline in muscle mass, which was found only in men. Our study showed a positive correlation between appendicular skeletal muscle index (ASMI) and common peroneal nerve amplitude and sural nerve amplitude with r=0.527, p<0.05; r=0.847, p<0.001 respectively. Furthermore, in multiple linear regression analyses, we found a positive relationship between ASMI and sural nerve amplitude after adjustment for confounders like age, duration of diabetes, and HbA1C (B=0.739; p<0.001).

CONCLUSION

As DPN patients are more prone to developing sarcopenia, and periodic assessment of skeletal muscle mass and function is warranted to initiate early lifestyle interventions in these patients, which will improve their quality of life.

Oxidative Stress and Mitochondrial Dysfunction Associated with Peripheral Neuropathy in Type 1 Diabetes

Significance: This review highlights the many intracellular processes generating reactive oxygen species (ROS) in the peripheral nervous system in the context of type 1 diabetes. The major sources of superoxide and hydrogen peroxide (H₂O₂) are described, and scavenging systems are explained. Important roles of ROS in regulating normal redox signaling and in a disease setting, such as diabetes, contributing to oxidative stress and cellular damage are outlined. The primary focus is the role of hyperglycemia in driving elevated ROS production and oxidative stress contributing to neurodegeneration in diabetic neuropathy (within the dorsal root ganglia [DRG] and peripheral nerve). Recent Advances: Contributors to ROS production under high intracellular glucose concentration such as mitochondria and the polyol pathway are discussed. The primarily damaging impact of ROS on multiple pathways including mitochondrial function, endoplasmic reticulum (ER) stress, autophagy, and epigenetic signaling is covered. Critical Issues: There is a strong focus on mechanisms of diabetes-induced mitochondrial dysfunction and how this may drive ROS production (in particular superoxide). The mitochondrial sites of superoxide/H₂O₂ production via mitochondrial metabolism and aerobic respiration are reviewed. Future Directions: Areas for future development are highlighted, including the need to clarify diabetes-induced changes in autophagy and ER function in neurons and Schwann cells. In addition, more clarity is needed regarding the sources of ROS production at mitochondrial sites under high glucose concentration (and lack of insulin signaling). New areas of study should be introduced to investigate the role of ROS, nuclear lamina function, and epigenetic signaling under diabetic conditions in peripheral nerve.

Protective effects of CHIP overexpression and Wharton's jelly mesenchymal-derived stem cell treatment against streptozotocin-induced neurotoxicity in rats

Diabetic neuropathy is a common complication of diabetes mellitus, posing a challenge in treatment. Previous studies have indicated the protective role of mesenchymal stem cells against several disorders. Although they can repair nerve injury, their key limitation is that they reduce viability under stress conditions. We recently observed that overactivation of the carboxyl terminus of heat shock protein 70 (Hsp70) interacting protein (CHIP) considerably rescued cell viability under hyperglycemic stress and played an essential role in promoting the beneficial effects of Wharton's jelly-derived mesenchymal stem cells (WJMSCs). Thus, the present study was designed to unveil the protective effects of CHIP-overexpressing WJMSCs against neurodegeneration using in vivo animal model based study. In this study, western blotting observed that CHIP-overexpressing WJMSCs could rescue nerve damage observed in streptozotocin-induced diabetic rats by activating the AMPKα/AKT and PGC1α/SIRT1 signaling pathway. In contrast, these signaling pathways were downregulated upon silencing CHIP. Furthermore, CHIP-overexpressing WJMSCs inhibited inflammation induced in the brains of diabetic rats by suppressing the NF-κB, its downstream iNOS and cytokines signaling nexus and enhancing the antioxidant enzyme system. Moreover, TUNEL assay demonstrated that CHIP carrying WJMSCs suppressed the apoptotic cell death induced in STZ-induced diabetic group. Collectively, our findings suggests that CHIP-overexpressing WJMSCs might exerts beneficial effects, which may be considered as a therapeutic strategy against diabetic neuropathy complications.

Patient Factors Impacting Baseline Motor Evoked Potentials (MEPs) in Patients Undergoing Cervical Spine Surgery for Myelopathy or Radiculopathy

STUDY DESIGN

Retrospective review of 2532 adults who underwent elective surgery for cervical radiculopathy or myelopathy with intraoperative neuromonitoring (IONM) with motor evoked potentials (MEPs) between 2017 and 2019.

OBJECTIVE

Evaluate attainability of monitorable MEPs across demographic, health history, and patient-reported outcomes measure (PROM) factors.

SUMMARY OF BACKGROUND DATA

When baseline IONM responses cannot be obtained, the value of IONM on mitigating the risk of postoperative deficits is marginalized and a clinical decision to proceed must be made based, in part, on the differential diagnosis of the unmonitorable MEPs. Despite known associations with baseline MEPs and anesthetic regimen or preoperative motor strength, little is known regarding associations with other patient factors.

METHODS

Demographics, health history, and PROM data were collected preoperatively. MEP baseline responses were reported as monitorable or unmonitorable at incision. Multivariable logistic regression estimated the odds of having at least one unmonitorable MEP from demographic and health history factors.

RESULTS

Age [odds ratio (OR)=1.031, P <0.001], sex (male OR=1.572, P =0.007), a primary diagnosis of myelopathy (OR=1.493, P =0.021), peripheral vascular disease (OR=2.830, P =0.009), type II diabetes (OR=1.658, P =0.005), and hypertension (OR=1.406, P =0.040) were each associated with increased odds of unmonitorable MEPs from one or more muscles; a history of thyroid disorder was inversely related (OR=0.583, P =0.027). P atients with unmonitorable MEPs reported less neck-associated disability and pain ( P <0.036), but worse SF-12 physical health and lower extremity (LE) and upper extremity function ( P <0.016). Compared with radiculopathy, unmonitorable MEPs in myelopathy patients more often involved LE muscles. Cord function was monitorable in 99.1% of myelopathic patients with no reported LE dysfunction and no history of hypertension or diabetes.

CONCLUSION

Myelopathy, hypertension, peripheral vascular disease, diabetes, and/or symptomatic LE dysfunction increased the odds of having unmonitorable baseline MEPs. Unmonitorable baseline MEPs was uncommon in patients without significant LE weakness, even in the presence of myelopathy.

Interactions between cannabinoid and opioid receptors in a mouse model of diabetic neuropathy

ABSTRACT

Diabetic neuropathy, often associated with diabetes mellitus, is a painful condition with no known effective treatment except glycemic control. Studies with neuropathic pain models report alterations in cannabinoid and opioid receptor expression levels; receptors whose activation induces analgesia. We examined whether interactions between CB1R and opioid receptors could be targeted for the treatment of diabetic neuropathy. For this, we generated antibodies that selectively recognize native CB1R-MOR and CB1R-DOR heteromers using a subtractive immunization strategy. We assessed the levels of CB1R, MOR, DOR, and interacting complexes using a model of streptozotocin-induced diabetic neuropathy and detected increased levels of CB1R, MOR, DOR, and CB1R-MOR complexes compared with those in controls. An examination of G-protein signaling revealed that activity induced by the MOR, but not the DOR agonist, was potentiated by low nanomolar doses of CB1R ligands, including antagonists, suggesting an allosteric modulation of MOR signaling by CB1R ligands within CB1R-MOR complexes. Because the peptide endocannabinoid, hemopressin, caused a significant potentiation of MOR activity, we examined its effect on mechanical allodynia and found that it blocked allodynia in wild-type mice and mice with diabetic neuropathy lacking DOR (but have CB1R-MOR complexes). However, hemopressin does not alter the levels of CB1R-MOR complexes in diabetic mice lacking DOR but increases the levels of CB1R-DOR complexes in diabetic mice lacking MOR. Together, these results suggest the involvement of CB1R-MOR and CB1R-DOR complexes in diabetic neuropathy and that hemopressin could be developed as a potential therapeutic for the treatment of this painful condition.

The Role of Long Noncoding RNA MALAT1 in Diabetic Polyneuropathy and the Impact of Its Silencing in the Dorsal Root Ganglion by a DNA/RNA Heteroduplex Oligonucleotide

Diabetic polyneuropathy (DPN) is the most common complication of diabetes, yet its pathophysiology has not been established. Accumulating evidence suggests that long noncoding RNA metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) plays pivotal roles in the regulation of cell growth and survival during diabetic complications. This study aimed to investigate the impact of MALAT1 silencing in dorsal root ganglion (DRG) sensory neurons, using an α-tocopherol-conjugated DNA/RNA heteroduplex oligonucleotide (Toc-HDO), on the peripheral nervous system of diabetic mice. We identified MALAT1 upregulation in the DRG of chronic diabetic mice that suggested either a pathological change or one that might be protective, and systemic intravenous injection of Toc-HDO effectively inhibited its gene expression. However, we unexpectedly noted that this intervention paradoxically exacerbated disease with increased thermal and mechanical nociceptive thresholds, indicating further sensory loss, greater sciatic-tibial nerve conduction slowing, and additional declines of intraepidermal nerve fiber density in the hind paw footpads. Serine/arginine-rich splicing factors, which are involved in pre-mRNA splicing by interacting with MALAT1, reside in nuclear speckles in wild-type and diabetic DRG neurons; MALAT1 silencing was associated with their disruption. The findings provide evidence for an important role that MALAT1 plays in DPN, suggesting neuroprotection and regulation of pre-mRNA splicing in nuclear speckles. This is also the first example in which a systemically delivered nucleotide therapy had a direct impact on DRG diabetic neurons and their axons.

Prospective dietary radical scavengers: Boon in Pharmacokinetics, overcome insulin obstruction via signaling cascade for absorption during impediments in metabolic disorder like Diabetic Mellitus

Diabetes mellitus is a metabolic disorder which is characterized based on the blood glucose level. This can be due to the lack of efficiency of utilizing insulin or lack of production of insulin. There are numerous therapies and medications which are available for the treatment of this disease which can reduce the risk of diabetes. But there is no permanent cure found. Nutritional antioxidants show a foremost role in sustaining the homeostasis of the oxidative equilibrium. They have imparted their electron donor efficacy in preventing aging and in cancer. Vitamin C, E, β-carotene, carotenoids, polyphenols and selenium have been appraised as antioxidant constituents in the human diet nourishment. This paper emphasizes on the role of antioxidants which help in reducing or maintaining the level of glucose in the body. Antioxidants are substances that reduces the damages to the cells caused by free radicals. The available treatment and medications and how the supplementation of antioxidants is different from them is also discussed. Different type of antioxidants and their treatment in curing the disease is further focused in this paper.

Graphical abstract

Mechanistic approach towards diabetic neuropathy screening techniques and future challenges: A review

Diabetic neuropathy, also called peripheral diabetic neuropathy (PDN), is among the most significant diabetes health consequences, alongside diabetic nephropathy, diabetic cardiomyopathy and diabetic retinopathy. Diabetic neuropathy is the existence of signs and indications of peripheral nerve damage in patients with diabetes after other causes have been governed out. Diabetic neuropathy is a painful and severe complication of diabetes that affects roughly 20% of people. The development of diabetic neuropathy is regulated by blood arteries that nourish the peripheral nerves and metabolic problems such as increased stimulation of polyol pathway, loss of myo-inositol and enhanced non-enzymatic glycation. It's divided into four types based on where neurons are most affected: autonomic, peripheral, proximal, and focal, with each kind presenting different symptoms like numbing, gastrointestinal disorders, and heart concerns. Pharmacotherapy for neuropathic pain is complex and for many patients, effective treatment is lacking; as a result, scientific proof recommendations are crucial. As a result, the current demand is to give the most vital medications or combinations of drugs that work directly on the nerves to help diabetic neuropathy patients feel less pain without causing any adverse effects. In diabetic neuropathy research, animal models are ubiquitous, with rats and mice being the most typically chosen for various reasons. This review covers the epidemiology, clinical features, pathology, clinical symptom, mechanism of diabetic neuropathy development, diagnosis, screening models of animals, diabetic neuropathy pharmacotherapy.

The Role of Extracellular Vesicles in Cancer-Nerve Crosstalk of the Peripheral Nervous System

Although the pathogenic operations of cancer–nerve crosstalk (e.g., neuritogenesis, neoneurogensis, and perineural invasion—PNI) in the peripheral nervous system (PNS) during tumorigenesis, as well as the progression of all cancer types is continuing to emerge as an area of unique scientific interest and study, extensive, wide-ranging, and multidisciplinary investigations still remain fragmented and unsystematic. This is especially so in regard to the roles played by extracellular vesicles (EVs), which are lipid bilayer-enclosed nano- to microsized particles that carry multiple-function molecular cargos, facilitate intercellular communication in diverse processes. Accordingly, the biological significance of EVs has been greatly elevated in recent years, as there is strong evidence that they could contribute to important and possibly groundbreaking diagnostic and therapeutic innovations. This can be achieved and the pace of discoveries accelerated through cross-pollination from existing knowledge and studies regarding nervous system physiology and pathology, as well as thoroughgoing collaborations between oncologists, neurobiologists, pathologists, clinicians, and researchers. This article offers an overview of current and recent past investigations on the roles of EVs in cancer–nerve crosstalk, as well as in neural development, physiology, inflammation, injury, and regeneration in the PNS. By highlighting the mechanisms involved in physiological and noncancerous pathological cellular crosstalk, we provide hints that may inspire additional translational studies on cancer–nerve interplay.

Prevalence of type 2 diabetes mellitus, impaired fasting glucose, general obesity, and abdominal obesity in patients with bipolar disorder: A systematic review and meta-analysis

OBJECTIVES

The study herein aimed to assess the prevalence of type 2 diabetes mellitus (T2DM), impaired fasting glucose (IFG), as well as general and abdominal obesity in patients with bipolar disorder (BD). We also compared the prevalence of T2DM and general obesity in patients with BD with age- and gender-matched healthy controls.

METHODS

A systematic search of Embase, Medline, PubMed, and APA PsycArticles was conducted from inception to June 2021 without language restrictions. Methodological quality was assessed using the Newcastle-Ottawa Scale (NOS) modified for case-control studies.

RESULTS

A total of forty-nine studies were included in this analysis. The pooled prevalence of T2DM was 9.6% (95% CI, 7.3-12.2%). Patients with BD had a nearly 1.6 times greater risk of developing T2DM compared to their age- and gender-matched controls (RR=1.57, 95% CI 1.36-1.81, p<0.001). In the present analysis, IFG is defined as a fasting plasma glucose (FPG) ≥ 100 mg/dL (FPG≥100) with a prevalence of 22.4% (95% CI, 16.7-28.7%), or as an FPG equal to or greater than 110 mg/d (FPG≥110) with a prevalence of 14.8% (95% CI, 10.8-19.3%). The prevalence of general obesity (BMI≥30 kg/m²) was 29.0% (95% CI, 22.8-35.6%); the risk of obesity was almost twice the rate reported in patients with BD compared to controls (RR=1.67, 95% CI 1.32-2.12, p<0.001). We also observed that more than half of the BD participants had abdominal obesity (i.e., prevalence of 51.1%; 95% CI, 45.0-57.3%).

LIMITATIONS

A significant degree of heterogeneity was detected. Sources of heterogeneity included differences in study designs, inclusion criteria, measurement tools, and data analysis methods.

CONCLUSION

Bipolar disorder is associated with a higher prevalence of T2DM, IFG, general obesity, and abdominal obesity. Type 2 diabetes mellitus and obesity are significantly more prevalent in patients with BD than in their age- and gender-matched controls.

STUDY REGISTRATION

CRD42021258431.

An Insight into Potential Pharmacotherapeutic Agents for Painful Diabetic Neuropathy

Diabetes is the 4th most common disease affecting the world's population. It is accompanied by many complications that deteriorate the quality of life. Painful diabetic neuropathy (PDN) is one of the debilitating consequences of diabetes that effects one-third of diabetic patients. Unfortunately, there is no internationally recommended drug that directly hinders the pathological mechanisms that result in painful diabetic neuropathy. Clinical studies have shown that anticonvulsant and antidepressant therapies have proven fruitful in management of pain associated with PDN. Currently, the FDA approved medications for painful diabetic neuropathies include duloxetine, pregabalin, tapentadol extended release, and capsaicin (for foot PDN only). The FDA has also approved the use of spinal cord stimulation system for the treatment of diabetic neuropathy pain. The drugs recommended by other regulatory bodies include gabapentin, amitriptyline, dextromethorphan, tramadol, venlafaxine, sodium valproate, and 5 % lidocaine patch. These drugs are only partially effective and have adverse effects associated with their use. Treating painful symptoms in diabetic patient can be frustrating not only for the patients but also for health care workers, so additional clinical trials for novel and conventional treatments are required to devise more effective treatment for PDN with minimal side effects. This review gives an insight on the pathways involved in the pathogenesis of PDN and the potential pharmacotherapeutic agents. This will be followed by an overview on the FDA-approved drugs for PDN and commercially available topical analgesic and their effects on painful diabetic neuropathies.

AMPK signaling in diabetes mellitus, insulin resistance and diabetic complications: A pre-clinical and clinical investigation

Diabetes mellitus (DM) is considered as a main challenge in both developing and developed countries, as lifestyle has changed and its management seems to be vital. Type I and type II diabetes are the main kinds and they result in hyperglycemia in patients and related complications. The gene expression alteration can lead to development of DM and related complications. The AMP-activated protein kinase (AMPK) is an energy sensor with aberrant expression in various diseases including cancer, cardiovascular diseases and DM. The present review focuses on understanding AMPK role in DM. Inducing AMPK signaling promotes glucose in DM that is of importance for ameliorating hyperglycemia. Further investigation reveals the role of AMPK signaling in enhancing insulin sensitivity for treatment of diabetic patients. Furthermore, AMPK upregulation inhibits stress and cell death in β cells that is of importance for preventing type I diabetes development. The clinical studies on diabetic patients have shown the role of AMPK signaling in improving diabetic complications such as brain disorders. Furthermore, AMPK can improve neuropathy, nephropathy, liver diseases and reproductive alterations occurring during DM. For exerting such protective impacts, AMPK signaling interacts with other molecular pathways such as PGC-1α, PI3K/Akt, NOX4 and NF-κB among others. Therefore, providing therapeutics based on AMPK targeting can be beneficial for amelioration of DM.

Bioanalytical methods for the detection of duloxetine and thioctic acid in plasma using ultra performance liquid chromatography with tandem mass spectrometry (UPLC-MS/MS)

Duloxetine and thioctic acid (TA) are standard drugs for treating diabetic neuropathy, a primary complication associated with diabetes. In this study, ultra performance liquid chromatography coupled with tandem mass spectrometry methods was successfully developed and validated for quantifying duloxetine and TA in biological samples. The protein precipitation method was used to extract duloxetine, TA and their internal standards from beagle dog plasma. A Hypersil Gold C18 column (150 × 2.1 mm, 1.9 μm) was used for the experiment. Isocratic elution with 0.1% formic acid in acetonitrile (A) and 0.1% formic acid (B) was used for duloxetine, whereas a gradient elution with 0.03% acetic acid (A) and acetonitrile (B) was used for TA. The validated parameters included linearity, sensitivity, accuracy, precision, selectivity, matrix effect, stability, and recovery under different conditions. The linear ranges of the calibration curves for duloxetine and TA were 5–800 ng/mL and 5–1,000 ng/mL, respectively. An intra- and inter-run precision of ± 15% can be observed in all quality control samples. These methods were successfully used for pharmacokinetics (PKs) studies in beagle dogs to compare PK differences in a fixed-dose combination including duloxetine and TA and co-administration of the 2 drugs.

2-Substituted Benzoxazoles as Potent Anti-Inflammatory Agents: Synthesis, Molecular Docking and In Vivo Anti-Ulcerogenic Studies

BACKGROUND

Non-steroidal anti-inflammatory drugs (NSAIDs) are the commonly used therapeutic interventions of inflammation and pain that competitively inhibit the cyclooxygenase (COX) enzymes. Several side effects like gastrointestinal and renal toxicities are associated with the use of these drugs. The therapeutic anti-inflammatory benefits of NSAIDs are produced by the inhibition of COX-2 enzymes, while undesirable side effects arise from the inhibition of COX-1 enzymes.

OBJECTIVES

In the present study, a new series of 2-substituted benzoxazole derivatives 2(a-f) and 3(a-e) were synthesized in our lab as potent anti-inflammatory agents with outstanding gastro-protective potential. The new analogs 2(a-f) and 3(a-e) were designed depending upon the literature review to serve as ligands for the development of selective COX-2 inhibitors.

METHODS

The synthesized analogs were characterized using different spectroscopic techniques (FTIR, 1HNMR, 13CNMR) and elemental analysis. All synthesized compounds were screened for their binding potential in the protein pocket of COX-2 and evaluated for their anti-inflammatory potential in animals using the carrageenan-induced paw edema method. Further 5 compounds were selected to assess the in vivo anti-ulcerogenic activity in an ethanol-induced anti-ulcer rat model.

RESULTS

Five compounds (2a, 2b, 3a, 3b and 3c) exhibited potent anti-inflammatory activity and significant binding potential in the COX-2 protein pocket. Similarly, these five compounds demonstrated a significant gastro-protective effect (p<0.01) in comparison to the standard drug, Omeprazole.

CONCLUSION

Depending upon our results, we hypothesize that 2-substituted benzoxazole derivatives have excellent potential to serve as candidates for the development of selective anti-inflammatory agents (COX-2 inhibitors). However, further assessments are required to delineate their underlying mechanisms.

Fracture Patterns in Type 1 and Type 2 Diabetes Mellitus: A Narrative Review of Recent Literature

PURPOSE OF REVIEW

In this narrative review, we have summarized the literature on fracture risk in T1DM and T2DM with a special focus on fracture site, time patterns, glucose-lowering drugs, and micro- and macrovascular complications.

RECENT FINDINGS

T1DM and T2DM were associated with an overall increased fracture risk, with preferent locations at the hip, vertebrae, humerus, and ankle in T1DM and at the hip, vertebrae, and likely humerus, distal forearm, and foot in T2DM. Fracture risk was higher with longer diabetes duration and the presence of micro- and macrovascular complications. In T2DM, fracture risk was higher with use of insulin, sulfonylurea, and thiazolidinediones and lower with metformin use. The increased fracture risk in T1DM and T2DM concerns specific fracture sites, and is higher in subjects with longer diabetes duration, vascular complications, and in T2DM with the use of specific glucose-lowering medication.