فهرست مطالب

Medical Hypotheses and Ideas - Volume:9 Issue:1, 2015
  • Volume:9 Issue:1, 2015
  • تاریخ انتشار: 1394/01/31
  • تعداد عناوین: 12
  • Azam Bazrafshan, Ali Akbar Haghdoost, Morteza Zare Pages 1-4
    This article reflects the comparison of downloads, readership and citation data for the Journal of Medical Hypotheses and Ideas. A brief analysis of the journal’s recent performance indicates that the journal articles appear to have a high rate of downloads around the world. Its published articles are from a variety of countries and the odds of accepted articles for publication is surprisingly even across regions. However, the rate of received citations to the published articles indicated a lack of considerable impact in scholarly publications. This approach has double value as it shows the overall impact of the journal in social web as well as scholarly publications and also provides future directions for the journal’s editorial boards. Altmetrics was also proposed as an alternative to the widely used citation and usage indicators in tracking the impact of individual articles.
    Keywords: Downloads, Journal usage indicators, Altmetrics, Readership, Journal of Medical Hypotheses, Ideas
  • Jiewen Dai, Hongbo Yu, Min Zhu, Steve Guofang Shen Pages 5-8
    Temporomandibular joint (TMJ) ankylosis can restrict the mandibular movement, followed by resulting in numerous problems. To understand the mechanism of TMJ ankylosis (TMJA) and prevent the generation of TMJA is urgent necessary. Although many factors contribute to it, trauma is the most common cause of TMJA. The mechanisms of TMJA are still unclear, and the distraction osteogenesis of the lateral pterygoid muscle (LPM) may play an important role. Injection of very small amounts of botulinum toxin type A (BTA) can temporarily block the muscle’s impulse and has been revealed to be an effective treatment method for many temporomandibular disorders. In this article, we make a hypothesis that LPM injection of BTA as a novel method for immobilization of mandible, followed by preventing the traumatic TMJA. Furthermore, the side effects of local injection of BTA also are minimal, temporary, reversible and self-limiting. If this strategy is validated, LPM injection of BTA will be a cost effective way to be administrated to prevent the traumatic TMJA.
    Keywords: Botulinum toxin A, Lateral pterygoid muscle, Prevention, Traumatic ankylosis, Temporomandibular joint
  • Zhihui Zhou, Weiwei Fan, Miaojie Lang, Yanliang Wang Pages 9-12
    Osteoradionecrosis of jaws (ORNJ) is a serious complication of radiotherapy for patients with head and neck cancer. As of yet, no universally accepted treatment exists for this chronic pathologic condition. It has been shown that ultrasound is an effective, noninvasive adjunctive therapy in ORNJ, as ultrasound can result in the increase of angiogenesis and bone production, which are essential for ORNJ healing. Recently, low-frequency ultrasound has been demonstrated to enhance the transdermal delivery of macromolecules and hydrophilic drugs (low-frequency sonophoresis, LFS). As a biological macromolecule, basic fibroblast growth factor (bFGF) also has potential osteoinductive and angiogenic properties. Herein, we present a hypothesis that LFS-mediated transdermal bFGF delivery is capable of improving the healing of ORNJ and will be a new effective adjunctive therapy to surgery. This treatment combines low-frequency ultrasound with bFGF to respectively promote vascularly compromised bone and soft tissue wound healing, and is expected to be more effective than ultrasound therapy alone.
    Keywords: Low, frequency sonophoresis, Basic fibroblast growth factor, Osteoradionecrosis of jaws
  • Yuan Zhang, Jie Zhu, Zhibing Wang, Yue Zhou, Xia Zhang Pages 13-19
    Total hip arthroplasty (THA) has progressed to be one of the most cost-effective surgical procedures to relieve pain and restore function to the pathological hip. Official retrospective statistics revealed over 500,000 cases of THA were performed per annum in the US alone, but failure cases brought about more than 40,000 revision procedures among them. The revision surgery is usually hard to manipulate due to the formidable difficulty of repairing the critical bone defect. Plenty of attempts aiming at tackling this problem have been dedicated by both tissue engineering and clinical investigators. Despite of the initial success, it is still a great challenge to overcome atypical intertrochanteric and diaphyseal defects of proximal femur to reach a satisfied therapeutic outcome in terms of long-term survivorship of the prosthesis. Given the interdisciplinary integration of biomaterial fabrication, bone tissue engineering, rapid prototyping, and biomacromolecule/drug delivery, we propose a hypothesis to construct a biphasic articular spacer to reach the dual goal of infection control and bone regeneration in this study. To be specific, this complex is consisted by a geometry-specific calcium phosphate sheath, derived from computer aided design and low temperature 3D printing, and an axial bone cement pillar delivering antibiotics. Theoretically, this modularized spacer possesses the potency of enhanced osteogenesis, controlled release of specific drugs, and co-delivery of growth factors. If this strategy is validated, further effort can be made to strengthen the printability of calcium phosphate using the 3D printing technique, and to accelerate its translation from lab to clinics.
    Keywords: Arthroplasty, Calcium phosphate, 3D printing, Articular spacer, Osteogenesis, Bone defect
  • R. Alelu, Paz Pages 20-23
    The molecular mechanisms of tumor metastasis remain largely unknown and undefined. A recent model suggests that a minor population of cells (cancer stem cells) is programmed to preferentially metastasize to specific organs based on their gene expression patterns. These cells have the ability to generate tumors after implantation into animal hosts, to self-renew and give rise to non-stem cells. In this paper I hypothesize that epigenetic mechanisms could play an important role in tumor metastasis through the reorganization of the bivalent chromatin marks in cancer stem cells in three phases: 1) the reprogramming of epigenetic marks in differentiation master regulator genes responsible for the differentiation to one particular lineage 2) the resolution of these bivalent chromatin marks forces cells to develop the necessary mechanisms to migrate to a new niche and 3) the epigenetic activation of the tissue-specific genes associated with the specific target organ and, simultaneously, the repression of genes associated with alternative developmental pathways.
    Keywords: Epigenetics, Cancer, Metastasis formation, Cancer stem cells
  • Hassan Niknejad, Masoumeh Mirmasoumi, Behzad Torabi, Nafiseh Deheshkar, Farahani Pages 24-28
    For stem cell therapy of degenerative diseases, it is necessary to differentiate stem cells into the specific lineage. There are several growth factors which have been used for differentiation of stem cells. Some growth factors can dose-dependently induce differentiation of stem cells so that the increase of growth factor concentration results in production of the higher level of differentiated cells. However, due to the toxicity of some differentiation factors (e.g. retinoic acid), the lower dose of growth factors for the specific lineage differentiation of stem cells is desirable. This paper suggests a new approach in the field of controlled growth factor delivery system using semiconductor nanocrystals; known as quantum dots (QDs). This system contains polymeric microencapsulated growth factor which is conjugated to near infrared (NIR) absorbing QDs. The control release of growth factors from microcapsules in the culture plates can be achieved by irradiation. To modulate growth factor release in response to stem cells needs for differentiation, the intensity and period of irradiation will be controlled. Our hypothesis is based on the fact that QDs can absorb NIR energy and by excitation of electrons and then vibrational relaxation of them become heated when they were irradiated and then release growth factors. We believe that controlled growth factors delivery through the suggested system is an effective method to reduce the amount of growth factors required for differentiation of stem cells.
    Keywords: Quantum dots, Nanocrystal, Near infrared, Stem cells, Differentiation, Growth factors
  • Hongwei Ma, Dunquan Xu, Yaqiong Wu, Yongtao Ma, Zhichao Li Pages 29-37
  • Aram Mokarizadeh, Parisa Esmaeili, Hamid Soraya, Kambiz Pages 38-44
    Despite great advances in clarifying the pathogenesis of multiple sclerosis (MS), the exact underlying mechanism has not been definitely established. However, the responsibility of cross-reactive antibodies as the initiating factor in MS pathogenesis is a novel idea. Recently, an antibody against-α-gliadin 33-mer peptide which is found in most patients with gluten sensitivity have shown to cross-react significantly with various neural antigens including asialoganglioside, synapsin, and myelin basic protein (MBP). Furthermore, evidence indicates that IL-17, circulating immune complexes and even antibodies produced during gluten sensitivity can contribute to blood–brain barrier (BBB) permeability. Accordingly, extravasation of these anti-α-gliadin antibodies (AGA; especially IgG isotype) through the impaired BBB thought to target asialoganglioside, synapsin, and MBP in neurons. This opsonization may trigger a series of cascade pathways including complement activation, antibody-dependent microglial cytotoxicity against neurons, secretion of inflammatory mediators, myelin sheath damage, chemokine expression, CNS inflammation, BBB disruption and then leukocyte infiltration. The present hypothesis introduces a new antibody-dependent alternative pathway which may lead to multiple sclerosis (MS) during gluten sensitivity.
    Keywords: Anti α gliadin antibody, Multiple sclerosis, Gluten sensitivity
  • Ravinder Jerath, Molly W. Crawford, Vernon A. Barnes Pages 45-56
    The human eyes and brain, which have finite boundaries, create a “virtual” space within our central nervous system that interprets and perceives a space that appears boundless and infinite. Using insights from studies on the visual system, we propose a novel fast processing mechanism involving the eyes, visual pathways, and cortex where external vision is imperceptibly processed in our brain in real time creating an internal representation of external space that appears as an external view. We introduce the existence of a three-dimension default space consisting of intrapersonal body space that serves as the framework where visual and non-visual sensory information is sensed and experienced. We propose that the thalamus integrates processed information from corticothalamic feedback loops and fills-in the neural component of 3D default space with an internal visual representation of external space, leading to the experience of visual consciousness. This visual space inherently evades perception so we have introduced three easy clinical tests that can assist in experiencing this visual space. We also review visual neuroanatomical pathways, binocular vision, neurological disorders, and visual phenomenon to elucidate how the representation of external visible space is recreated within the mind.
    Keywords: Retina, 3D default space, Corticothalamic feedback loops, Thalamus, Visual consciousness, Intrapersonal space
  • Q.Y. Liu Pages 57-60
    Scientists theorized that β-amyloid (Aβ) plaques and tau tangles are involved in the development of Alzheimer’s disease (AD), and amyloid precursor protein (APP) produces Aβ to trigger the disease process. However, the normal synaptic function of APP itself is not fully understood. Several findings cast APP as a potential key player in learning and memory under normal condition. Nevertheless, the regular operation of APP will be disrupted by abnormal accumulation of Aβ under cellular pathological conditions. Herein, there is a hypothesis that AD could be treated by attenuating APP synthesis during cellular pathophysiological stress. In virtue of a previous study, it was speculated that cells could not decrease APP synthesis via self-protection maybe because APP is synthesized via internal ribosome entry segment (IRES)-mediated translation. Consequently, the blockage of this translation might be a new inoffensive and high-level specificity treatment.
    Keywords: Alzheimer's disease, Amyloid precursor protein, IRES, mediated translation, RNA editing
  • Maryam Erfan Manesh, Abdolreza Esmaeilzadeh, Mehri Hajikhan Mirzaei Pages 61-66
    Hodgkin’s Lymphoma (HL) as a prevalent hematolymphoid malignancy begins in cells of immune system and is characterized by the specific histologic, clinical properties. Abnormality in apoptosis has been recognized as a crucial pathway in its progression. Nowadays, 35–40% of patients in stages III and IV show disease relapse or symptoms of refractory to first-line chemotherapy; therefore, novel treatment strategies are required. As apoptosis inducing is an important mechanism in cancer treatments, novel anticancer molecules to induce programmed cell death are required. The authors present a novel therapeutic approach for HL, with regard to anti-tumoral and immunomodulatory effects of the mda-7/IL-24. This gene, located in human chromosome 1q32-33, has shown tumor suppressor activity in various human malignant cells in, in vitro, in vivo, and even in clinical trial studies. Our hypothesis was designed to evaluate anti- tumoral effects of mda-7/IL-24 in SCID mice model using the adenovirus-based vector. mda-7/IL-24 interestingly has antiangiogenic, immunomodulatory, and bystander antitumoral activities. mda-7/IL-24 can suppress anti-apoptotic Bcl-2 family proteins, and induces GADD family, Bak, Bax, and other pro-apoptosis proteins. This hypothesis suggests that adenovirus vectors expressing mda-7/IL-24 may help for effective immunotherapies of HL.
    Keywords: Hodgkin Lymphoma, IL, 24, Apoptosis, Immune system up, regulation, Gene therapy
  • Hamid Abdollahi, Mohammadreza Atashzar, Maryam Amini Pages 67-71
    Radiation induced injury is a limiting factor in radiation related approaches from earth to space. Inductions of a wide spectrum of damages in radiotherapy patients due to unwanted normal tissues irradiation and space radiation related diseases in astronauts have been caused many limitations in cancer treatment and space missions. There are many radiation protection/mitigation approaches including: physical, chemical, biological and physiological methods. Radiation protection using these methods is expensive and also has many problems including acute toxicities and difficulties in their targeting to normal tissues. Based on experimental and hypothetical data, showing that medical/biological gases have many protective effects such as antioxidant, anti-inflammatory, anti-apoptotic, and induction of radioresistance, we hypothesize that similar gases which have been produced by microorganisms (biogases) have those properties and may be used as radiation mitigators/protectors in radiation related approaches such as radiotherapy, radiation accidents and in space missions. Isolation microorganism in safe laboratory conditions in enough amounts, finding non-toxic dose of microorganisms that provide highest radioprotection percent, dose reduction factor (DRF) calculation to compare the radioprotective efficacy of the microorganisms, finding the best targeting techniques to deliver those microorganisms into normal tissues, genetically manipulations of microorganism to achieve the highest amount of biogases with lowest side effects can be done for testing the hypothesis.
    Keywords: Radiation protection, Biogas, Microorganisms, Hypothesis