Investigations in acute and chronic allodynia : using human psychophysics, sensory analysis, glial modulation & functional proteomics in the dorsal horn of the spinal cord

In many chronic pain pathologies, stimuli that are normally non-painful to healthy humans, such as light touch or small decrements in temperature, can cause painful responses – a phenomenon called allodynia. The majority of research on tactile allodynia has focused on myelinated low threshold A mechanoreceptors (A-LTMR) that are otherwise known to mediate innocuous mechano-sensation (1, 2). Recently, there is a growing recognition of the contribution of more than one class of low threshold fibres to pain processing, i.e. unmyelinated low threshold C mechanoreceptors (C-LTMRs), which are believed to be responsible for affective touch processing. (3-6). The first evidence of the contribution of C tactile fibres (CTs), the human counterpart of C-LTMRs, to cutaneous allodynia was shown in human models of rapid-onset skin and muscle pain as well as delayed-onset muscle soreness (3-9). In addition, recent studies in transgenic mice, in both acute and chronic pain models, have provided molecular mechanisms at the spinal level, which functionally correspond to the tactile and cold allodynia perceived in human subjects (10-13). In the last few years, both animal and human studies have argued for a convergence of low threshold C fibre input to nociceptive fibre signalling at the dorsal horn level (3, 4, 7, 10, 14-17). On the basis of the behavioural observations of bilateral cold and tactile allodynia post unilateral median nerve injury (from Paper I) in this thesis, it is hypothesised that central interactions of fibres conducting noxious (i.e. nociceptors) as well as non-noxious stimuli (i.e.non-nociceptors) at the dorsal horn level are responsible in driving these sensations. In addition, the actions of spinal immune cells in the dorsal horn such as microglia and astrocytes to influence nociceptive processing have been firmly established (18-22). Akin to the canonical perspective of attributing allodynia to A-LTMRs, the role of spinal glial cells in injury induced hypersensitivity has always been looked at in the context of these ALTMRs in addition to the unmyelinated high threshold C nociceptors (20, 23, 24). From previous observations of such neuro-glial modulation mentioned above, it is hypothesized that the glial cells can modulate bilateral noxious signalling and the percept of allodynia evoked by otherwise innocuous stimuli, i.e. normally non-painful touch and cooling in this model of bilateral allodynia due to a unilateral nerve injury. Incidentally, rapid cooling and non-painful gentle touch are hallmark of CTs in humans (5, 6) and in mice (10, 12, 13) and hence, cannot be ignored as one of the likely substrates of this phenomena in this rat model. In the dorsal horn, lamina II, which is the main termination site of CT inputs, has been postulated to act as a 'gate' for processing noxious as well as innocuous information by converging and processing inputs from superficial as well as deep dorsal horn (25). This work supports the view, also discussed in Abraira, Kuehn (26), that of low and high threshold inputs from the periphery, it is the dorsal horn (lamina I-III), that acts as the primary convergence centre to 'gate' or 'gain' painful and non-painful information before it is passed over to higher order neurons. Furthermore, by studying the neuronal and nonneuronal interactions in the dorsal horn at the peak time point of the bilateral allodynia seen in our model, it is possible to understand the biochemical changes responsible for this behaviour. These changes help us understand key mechanisms of protein signalling at the cellular dorsal horn that has been often overlooked in other experiments involving proteomics due to experimental bias. Hence, the animal studies in this thesis provide a greater understanding of mechanisms of allodynia and its modulation using pharmacological tools in animals. In rats, following a unilateral median nerve injury, bilateral allodynia was ameliorated using minocycline, a glial inhibitor, by modulation of the dorsal horn interactions between glia and primary afferent fibres that respond to non-painful stimuli. These interactions (Paper I & II) were studied using immuno-staining and proteomic profiling of the dorsal horn – prior to and following nerve injury and its modulation by minocycline. The key result from the animal work, presented in this thesis, is the presentation of modulatory proteins responsible for the sensory behaviour at the contralateral, uninjured side as opposed to the primarily studied injured side of the dorsal horn. To understand the ‘gating’ and ‘gaining’ mechanism of the dorsal horn discussed previously in rodent models, it is important to ask what dissimilates the perception of painfulness from non-painfulness or pleasure in humans with acute pain. Therefore, in healthy humans (Paper III), pain modulation was tested in the context of acute background muscle pain with concurrent ‘affective’ tactile stimulation. Furthermore, the resulting percept and its peripheral substrates was determined using a preferential block of myelinated fibres. In this study, we demonstrated that activation of CTs can produce a stimulus-locked, bi-directional (excitatory/inhibitory) affective modulation of pain that is consistent with previously documented CT function in the rodent dorsal horn. From this human study, it is hypothesised that CT dependent context driven affective stimulus can determine the direction of the perception, in this case, pleasurable or painful. This study also presents with the idea that long term changes in the dorsal horn circuitry may not be necessary to initiate this type of context-dependent bi-directional stimulation and can be achieved in an acute setting. Hence, the animal and human studies combine the animal sensory behaviour and human perception of allodynia (and its modulation) to explore the link between the activation of low threshold sensory fibres such as CTs (by innocuous stimuli) and nociceptive processing in acute and pathological pain states. This thesis comprises of an introduction section and 3 manuscripts. The introduction provides a short review of the peripheral and central mechanisms of allodynia with the aim of interlacing it with the work presented in the 3 manuscripts (referred to in the text by their Roman numerals)

Video Forgery Detection: A Comprehensive Study of Inter and Intra Frame Forgery With Comparison of State-Of-Art

Availability of sophisticated and low-cost smart phones, digital cameras, camcorders, surveillance CCTV cameras are extensively used to create videos in our daily life. The prevalence of video sharing techniques presently available in the market are: YouTube, Facebook, Instagram, snapchat and many more are in utilization to share the information related to videos. Besides this, there are many software which can edit the content of video: Window Movie Maker, Video Editor, Adobe Photoshop etc., with this available software anyone can edit the video content which is called as “Forgery” if edited content is harmful. Usually, videos play a vital role in terms of proof in crime scene. The Victim is judged by the proof submitted by the lawyer to the court. Many such cases have evidenced that the video being submitted as proof is been forged. Checking the authentication of the video is most important before submitting as proof. There has been a rapid development in deep learning techniques which have created deepfake videos where faces are replaced with other faces which strongly made a belief of saying “Seeing is no longer believing”. The available software which can morph the faces are FakeApp, FaceSwap etc., the increased technology really made the Authentication of proofs very doubtful and un-trusty which are not accepted as proof without proper validation of the video. The survey gives the methods that are capable of accurately computing the videos and analyses to detect different kinds of forgeries. It has revealed that most of the existing methods are relying on number of tampered frames. The proposed techniques are with compression, double compression codec videos where research is being carried out from 2016 to present. This paper gives the comprehensive study of techniques, algorithms and applications designed and developed to detect forgery in videos

Complicated to operate case of appendicitis: A rare incident

Introduction: Appendicitis is an appendix inflammation that’s severe. It affects people of all ages but is most common between the ages of 10 to 30, and both men and women are afflicted equally. Appendicitis is substantially less common in developing nations, particularly regions of Africa, and among lower socioeconomic levels. Clinical Findings: Pain in the right iliac fossa, nausea, vomiting. Diagnostic Evaluation: Blood test: Hb-14.5 gm%, Total RBC count-4.5 millions/cu mm, Total WBC count-8000/cu mm, Total Platelet count-2.5 lac/cu mm, Albumin-4.1 gm%, Bilirubin (conjugated)-0.4 gm%, Bilirubin(unconjugated)-1.1 gm%. On a CT scan of the abdomen and pelvis, an abnormal appendix (diameter >6 mm) was discovered, or a calcified appendices eolith was discovered in conjunction with peri appendiceal inflammation and fat stranding. Therapeutic Intervention: Inj. Amoxicillin 500 mg x OD, Tab. Emset 4mg x TDS, Inj. Tramadol 100 mg x TDS, Tab. Limcee 500 mg x OD, Tab. Pantoprazole 40 mg x OD. Outcome: After treatment, the patient’s condition improved. His pain is relieved, and now the patient is good. Conclusion: My patient was admitted with the complaint of pain in the right iliac fossa, nausea and vomiting. Diagnosis confirmed the case of Appendicitis. After getting the proper treatment, the patient’s condition got improved

Rescuing the End-user systems from Vulnerable Applications using Virtualization Techniques

In systems owned by normal end-users, many times security attacks are mounted by sneaking in malicious applications or exploiting existing software vulnerabilities through security non-conforming actions of users. Virtualization approaches can address this problem by providing a quarantine environment for applications, malicious devices, and device drivers, which are mostly used as entry points for security attacks. However, the existing methods to provide quarantine environments using virtualization are not transparent to the user, both in terms of application interface transparency and file system transparency. Further, software configuration level solutions like remote desktops and remote application access mechanisms combined with shared file systems do not meet the user transparency and security requirements. We propose qOS, a VM-based solution combined with certain OS extensions to meet the security requirements of end-point systems owned by normal users, in a transparent and efficient manner. We demonstrate the efficacy of qOS by empirically evaluating the prototype implementation in the Linux+KVM system in terms of efficiency, security, and user transparency.Comment: 14 pages, 9 figure

Fistulotomy versus fistulectomy for simple fistula in ano: a retrospective cohort study

OBJECTIVE: To compare fistulotomy with fistulectomy for wound healing, duration of surgery, post-operative pain, incontinence and recurrence in patients with fistula in ano. METHODS: This retrospective cohort study was conducted at the Aga Khan University Hospital, Karachi, and comprised data of adults who had undergone fistulotomy/fistulectomy for simple fistula in ano from January 2007 to August 2012. Data collection was done in August 2013 using questionnaire and telephonic interviews. Outcome variables like duration of wound healing, recurrence, incontinence, duration of surgery and post-operative pain were compared in both the groups. SPSS 19 was used for data analysis. RESULTS: Of the 192 cases, there were 96(50%) in each group. The mean age was 40.51 years (range: 21-72 years) in the fistulotomy group and 41.14 years (range: 21-66 years) in the fistulectomy group (p=0.66). Both groups were comparable for baseline demographic variables. The median duration of wound healing was shorter in the fistulotomy group 15 days (Interquartile range: 7-20 days) compared to the fistulectomy group 30 days (Interquartile range: 15-42 days) (p\u3c0.001). The incidence of recurrence was comparable in fistulotomy vs. fistulectomy (3[3.12%] vs. 4[4.16%]; p=0.70). The incidence of incontinence was higher in fistulotomy compared to fistulectomy (5[5.3%] vs. 12[12.5%]; p=0.07). The severity of incontinence was also compared but the difference was insignificant (p=0.06). The median duration of surgery was significantly shorter in fistulotomy group 17 minutes (Interquartile range: 12-25 minutes) compared to fistulectomy group 25 minutes Interquartile range: 20-35 minutes (p\u3c0.001). The median post-operative pain in the surgical day care unit and at the first follow-up in clinic was zero for both groups. CONCLUSIONS: Fistulotomy yielded better results than fistulectomy since it significantly decreased the duration of wound healing and duration of surgery without increasing the incidence of recurrence, incontinence and post-operative pain

Silicon alleviates PEG-induced osmotic stress in finger millet by regulating membrane damage, osmolytes, and antioxidant defense

Drought restricts plant growth and productivity. Silicon has beneficial effects on imparting drought tolerance in plants. Present work was intended to evaluate the effect of Si on polyethylene glycol-6000 (PEG) induced osmotic stress in local landraces of finger millet. The seeds of stress-tolerant and stress-sensitive landraces of finger millet were treated with distilled water, 15% PEG, and PEG+Si (5-25 ppm). The ameliorative effect of Si was evaluated in terms of percentage seed germination, seedling growth, accumulation of osmolyte and activity of antioxidative enzymes. PEG-induced osmotic stress reduced seed germination, seedling growth, and augmented osmolyte accumulation. It also elevated the levels of antioxidant enzymes. The exogenous supplementation of silicon significantly improved seed germination as well as early seeding growth. Positive effects of Si were reflected in decline in malondialdehyde (MDA) content and improved glycine betaine content and antioxidant enzymes in PEG-induced stress tolerant as well as susceptible landraces. The Si-induced ameliorated effects on all the parameters studied were more pronounced in the stress-tolerant landrace (FM/ST/01) than the stress-sensitive landrace (FM/RT/01). These results clearly indicate advantageous effects of Si in relieving PEG-induced stress during seed germination and early seeding growth and suggest a possibility of better stand establishment by application of silicon containing fertilizer during seed sowing

Psychophysical Investigations into the Role of Low-Threshold C Fibres in Non-Painful Affective Processing and Pain Modulation

We recently showed that C low-threshold mechanoreceptors (CLTMRs) contribute to touch-evoked pain (allodynia) during experimental muscle pain. Conversely, in absence of ongoing pain, the activation of CLTMRs has been shown to correlate with a diffuse sensation of pleasant touch. In this study, we evaluated (1) the primary afferent fibre types contributing to positive (pleasant) and negative (unpleasant) affective touch and (2) the effects of tactile stimuli on tonic muscle pain by varying affective attributes and frequency parameters. Psychophysical observations were made in 10 healthy participants. Two types of test stimuli were applied: stroking stimulus using velvet or sandpaper at speeds of 0.1, 1.0 and 10.0 cm/s; focal vibrotactile stimulus at low (20 Hz) or high (200 Hz) frequency. These stimuli were applied in the normal condition (i.e. no experimental pain) and following the induction of muscle pain by infusing hypertonic saline (5%) into the tibialis anterior muscle. These observations were repeated following the conduction block of myelinated fibres by compression of sciatic nerve. In absence of muscle pain, all participants reliably linked velvet-stroking to pleasantness and sandpaper-stroking to unpleasantness (no pain). Likewise, low-frequency vibration was linked to pleasantness and high-frequency vibration to unpleasantness. During muscle pain, the application of previously pleasant stimuli resulted in overall pain relief, whereas the application of previously unpleasant stimuli resulted in overall pain intensification. These effects were significant, reproducible and persisted following the blockade of myelinated fibres. Taken together, these findings suggest the role of low-threshold C fibres in affective and pain processing. Furthermore, these observations suggest that temporal coding need not be limited to discriminative aspects of tactile processing, but may contribute to affective attributes, which in turn predispose individual responses towards excitatory or inhibitory modulation of pain

The evolution of mineral processing in extraction of rare earth elements using liquid-liquid extraction: A review

The attempt to extract rare earth elements (REE) has started over a century ago using activated carbon and continues until today with various methods involved to improve the extraction yield. Instead of solid-liquid extraction, the use of liquid-liquid extraction (LLE) has been more common due to the convenient arrangement of the process. Solvent extraction is the main process applied in LLE of REE and along the way, various kind of solvent extractants have evolved. The use of traditional extractants (e.g., benzene, heptane, and kerosene) in LLE has been diverted to the application of conventional extractants (e.g., tributyl phosphate (TBP), di-(2-ethylhexyl)phosphoric acid (D2EHPA), and Cyanex 923 to increase the extraction efficiency. Apparently, the disadvantages of conventional extractants have led to the application of ionic liquid (IL) in the evolution of extraction of REE. IL was found as a potential extractant for REE due to its ability to extract certain metals, green solvent, and has the flexibility to create different combination of cation and anion. However, conventional extractants appear to be more effective in the extraction of REE compared to IL. Therefore, the complex solvents are then compromised and synergised to create better extractant with both advantages between conventional extractants and IL. Most synergistic extractants (SE) appear to be more effective in the extraction of REE and able to reduce the use of chemicals. These advantages make SE more desirable in solvent extraction. This paper highlights the evolution of REE extraction using various kind of extractants with advantages and disadvantages discoveries based on various literatures

Extraction of light, medium and heavy rare-earth elements using synergist extractants developed from ionic liquid and conventional extractants

This study focuses on the extraction of rare-earth elements (REE) using eight newly formulated synergist extractants and the performance was compared with that using the conventional extractants. Extraction was conducted on selected REE namely praseodymium (Pr), gadolinium (Gd) and dysprosium (Dy) representing light, medium and heavy REE, respectively. The synergist extractant of A336-[C2mim][NTf2] appeared to be the most positive synergist extractant, especially in the extraction of Pr and Dy based on a 90% increase in the extraction efficiency compared to the conventional extractant of A336. Apparently, the presence of the ionic liquid [C2mim][NTf2] in the synergist extractant altered the anion exchanger of A336 and successfully formulated extractant with a high extraction efficiency. The characterisation studies of A336-[C2mim][NTf2] show the synergist compatibility between A336 and [C2mim][NTf2]. Apparently, not all synergist extractants could elevate the extraction potential until conducting a sequence of tests

Extraction of rare earth element using synergist extractant immobilised resins (SEIR)

Extraction of REE using new combination of synergi st extractant between conventional extractant with ionic liquid. Improvise the convention-al technique in extraction of REE from LLE into SLE using industrial resin immobilised with synergist extractant