Read by QxMD icon Read

Medical Hypotheses

Omid Kohannim, Jimmy C Huang, Gasser M Hathout
Crossed cerebellar diaschisis (CCD) refers to transneuronal degeneration of the corticopontocerebellar pathway, resulting in atrophy of cerebellum contralateral to supratentorial pathology. CCD is traditionally diagnosed on nuclear medicine studies. Our aim is to apply a biexponential diffusion model, composed of intracellular and extracellular compartments, to the detection of subthreshold CCD on DWI, with the calculated fraction of the intracellular compartment as a proposed measure of cell density. At a voxel-by-voxel basis, we solve for intracellular and extracellular coefficients in each side of the cerebellum and compare the distribution of coefficients between each hemisphere...
November 2018: Medical Hypotheses
Jüri Engelbrecht, Kert Tamm, Tanel Peets
Experiments have demonstrated that signals in nerve fibers are composed by electrical and mechanical components. In this paper a coupled mathematical model is described which unites the governing equations for the action potential, the pressure wave in the axoplasm and the longitudinal and the transverse waves in the surrounding biomembrane into one system of equations. As a solution of this system, an ensemble of waves is generated. The main hypotheses of such a model are related to the nature of coupling forces between the single waves in the ensemble...
November 2018: Medical Hypotheses
Seong Chin
Although a wheel is an ideal method for transportation and the invention of the spoke wheel made a wheel lighter and swifter, a wheel cannot function well on slanted or rough surfaces; these are common in the natural environment. Further, the load support of the wheel is limited to a point of the whole wheel in contact with the ground. Then, we humans may be using the legs as a part of spoke wheel and place our legs and feet on the ground alternatively to support the body weight while the gravitational torque makes the center of mass (COM) rotate around the hip joint when proper stiffness and balance is made...
November 2018: Medical Hypotheses
Eiliv Lund, Lill-Tove Rasmussen Busund, Jean-Christophe Thalabard
The theory of breast cancer as a child deficiency disease is an inversion of the current paradigm, which considers full-term pregnancies to be a protective factor and uses nulliparous women as the reference group. Instead, the theory of breast cancer as a child deficiency disease says that women with the highest parity (about 20, which is the limit of human fertility) are those with the lowest risk and should be used as the reference group in risk estimations. This theory is explained biologically by converting parity from the simple value of number of children into an understanding of the long-lasting biological and immunological effects of pregnancy...
November 2018: Medical Hypotheses
Sheila N Garland, Michael R Irwin, Donn Posner, Michael L Perlis
Sleep continuity disturbance (also known as insomnia) and fatigue are common complaints of individuals diagnosed with cancer. Traditionally, many have believed that sleep continuity disturbance and fatigue are caused, in large measure, by the impact of the cancer diagnosis and treatment. Recent prospective research suggests however, that sleep continuity disturbance and fatigue may actually precede a cancer diagnosis. We suggest that sleep continuity disturbance and fatigue may in fact represent prodromal symptoms of cancer...
November 2018: Medical Hypotheses
Fabijan Lulić, Zdravko Virag, Marko Jakopović, Ivan Korade
A reliable noninvasive method for the estimation of pulmonary function in healthy and diseased subjects should be of great importance in the prognosis, diagnosis, and treatment of pulmonary hypertension. Here we propose such a method, which is based on the parameter identification of the five-element Windkessel model of pulmonary circulation. The method requires the following input variables: the heart rate, the stroke volume, the Doppler echocardiographic measurements of the tricuspid regurgitation and the pulmonary valve velocity profiles, and estimations of the right atrium and the pulmonary vein pressure...
November 2018: Medical Hypotheses
Kayle Dickson, Simo Liu, Juan Zhou, Morgan Langille, Bruce E Holbein, Christian Lehmann
Iron chelation has been proposed as a potential therapy for polybacterial abdominal sepsis. Treatment with iron chelation is known to be able to attenuate bacterial growth. It is hypothesized that the different types of bacteria will exhibit variations in their sensitivity to iron chelation based on differences in their iron metabolism. Bacteria with weaker iron access systems might have their growth reduced initially, but stronger species may also be suppressed. Gram-positive and Gram-negative bacteria are known to possess different iron acquisition systems, which may affect their response to iron chelation...
November 2018: Medical Hypotheses
Frank Comhaire
Myalgic Encephalopathy/Chronic Fatigue Syndrome (ME/CFS) is an enigmatic disease the pathogenesis of which remains elusive. Pragmatic proof-of-principle of the hypothetical mechanisms causing the clinical symptoms has been delivered, but it is hard to explain why some patients do respond favourably to treatment with sodium dichloroacetate (DCA), which enhances the activity of the mitochondrial enzyme pyruvate dehydrogenase, but other patients experience no benefit from this substance. In a prospective trial including 35 ME/CFS patients, logistic regression analysis with stepwise elimination has identified 6 pre-treatment characteristics allowing for the differentiation between responders (n = 13) and non-reponders (n = 22) with high accuracy (P < 0...
November 2018: Medical Hypotheses
G Polidori, S Cuttell, L Hammond, D Langdon, F Legrand, R Taiar, F C Boyer, J T Costello
The aim of this study was to investigate how body thermal resistance between sexes evolves over time in the recovery period after a WBC session and to show how this parameter should be considered as a key parameter in WBC protocols. Eighteen healthy participants volunteered for the study (10 males and 8 females). Temperature (core and skin) were recorded pre- and post (immediately and every 5 min until 35 min post) exposure to a single bout of WBC (30 s at -60 °C, 150 s at -110 °C). From both core and skin temperatures a bio-heat transfer model was applied which led to the analytical formulation of the body thermal resistance...
November 2018: Medical Hypotheses
Hui-Min Wu, Juan Wei, Kai Wang, Ying Qi, Fang-Yu Wang
Inflammatory bowel disease (IBD) is a group of intestinal non-specific inflammatory diseases with unclear pathogenesis, characterized with the impaired intestinal mucosal barriers and the activated immune system. Mucus layer is the vital protector over the intestinal epithelia cells (IECs). Mucus layer with impaired function could not provide isolated protection for IECs and thus proteases and pathogens from the gut lumen attacked and damaged the epithelial layer. Clinical manifestation and histopathology suggest that IBD might be a self-digestive inflammatory disease caused by digestive enzymes...
November 2018: Medical Hypotheses
Rob Janssen, Bart de Brouwer, Jan H von der Thüsen, Emiel F M Wouters
Although fibrosis and emphysema are in many ways on opposite ends of the pulmonary parenchymal disease spectrum, they seem to share common pathomechanistic steps. This is illustrated by the coexistence of both entities in lungs of individuals with combined pulmonary fibrosis and emphysema. Macroproteins elastin and collagen are major constituents of the pulmonary extracellular matrix. The prevailing paradigm states that emphysema is caused by an imbalance between destructive proteolytic and protective antiproteolytic enzymes leading to accelerated degradation of elastin fibers in the lungs...
November 2018: Medical Hypotheses
A Thirumal Raj, Shankargouda Patil, Archana A Gupta
No abstract text is available yet for this article.
November 2018: Medical Hypotheses
Ruzena Tkacova
Obstructive sleep apnoea (OSA) is a highly prevalent medical condition and amajor cardiovascular risk factor. Obesity is present in ∼70% of patients with OSA, nevertheless, continuous positive airway pressure (CPAP) ventilation - the gold standard therapy for moderate and severe OSA - has no appreciable long-term beneficial effects on obesity, body composition, energy metabolism, physical activities or the incidence of major cardiovascular events. Therefore, effective weight loss strategies in conjunction with CPAP therapy in OSA are critically needed...
November 2018: Medical Hypotheses
Lin Yu, Yayun Zheng, Ying Feng, Fang Ma
In either natural fertilization or artificial insemination, hundreds of millions of sperm are ejaculated or inseminated and then deposited in the female reproductive tract, but only a few sperm reach the ampulla or the site of fertilization. This dramatic reduction in numbers clearly highlights the obstacles that sperm must overcome in order to reach the destination for egg fertilizing. Phagocytosis of sperm by leukocytes are repeatedly observed and generally considered to be one of the most important barriers, but the mechanism of the phagocytosis of sperm remains unclear...
November 2018: Medical Hypotheses
Leo Pruimboom, Frits A J Muskiet
Chronic non-communicable diseases (CNCD) are the leading cause of mortality in developed countries. They ensue from the sum of modern anthropogenic risk factors, including high calorie nutrition, malnutrition, sedentary lifestyle, social stress, environmental toxins, politics and economic factors. Many of these factors are beyond the span of control of individuals, suggesting that CNCD are inevitable. However, various studies, ours included, show that the use of intermittent challenges with hormetic effects improve subjective and objective wellbeing of individuals with CNCD, while having favourable effects on immunological, metabolic and behavioural indices...
November 2018: Medical Hypotheses
Mariam M Morchiladze, Tamila K Silagadze, Zurab K Silagadze
Visceral theory of sleep states that the same brain neurons, which process external information in wakefulness, during sleep switch to the processing of internal information coming from various visceral systems. Here we hypothesize that a failure in the commutation of exteroceptive and interoceptive information flows in the brain can manifest itself as a mental illness.
November 2018: Medical Hypotheses
John Leach
The term 'give-up-itis' describes people who respond to traumatic stress by developing extreme apathy, give up hope, relinquish the will to live and die, despite no obvious organic cause. This paper discusses the nature of give-up-itis, with progressive demotivation and executive dysfunction that have clinical analogues suggesting frontal-subcortical circuit dysfunction particularly within the dorsolateral prefrontal and anterior cingulate circuits. It is hypothesised that progressive give-up-itis is consequent upon dopamine disequilibrium in these circuits, and a general theory for the cause and progression of give-up-itis is presented in which it is proposed that give-up-itis is the clinical expression of mental defeat; in particular, it is a pathology of a normal, passive coping response...
November 2018: Medical Hypotheses
Anna M Sandgren, Robert J M Brummer
The microbiome-gut-brain axis paradigm explains that alterations in the central nervous system and behavior may be secondary to functional changes in the gut in general and more specifically the enteric nervous system. An unfavorable development of the intestinal microbial ecosystem, leading to e.g. a diminished microbial diversity, may play a central role. This paper outlines, and describes the theoretical basis of, a novel integrative model explaining the etiology and pathogenesis of ADHD in a microbiota-gut-brain context, taking into account the complexity of the bi-directional signaling between the gut and the brain...
November 2018: Medical Hypotheses
Viviana Mucci, Yves Jacquemyn, Angelique Van Ombergen, Paul H Van de Heyning, Cherylea J Browne
INTRODUCTION: Mal de Debarquement Syndrome (MdDS) is a condition characterized by a sensation of motion in the absence of a stimulus, which presents with two subtypes depending on the onset: Motion-Triggered, and Spontaneous or Non-Motion Triggered. MdDS predominantly affects women around 40-50 years of age and a high number of patients report associated disorders, such as migraine and depression. The pathophysiology of MdDS is unclear, as is whether there are predisposing factors that make individuals more vulnerable to developing the condition...
November 2018: Medical Hypotheses
Mehmet Gunduz, Daichi Murakami, Ihsan Gunduz, Shunji Tamagawa, Masanobu Hiraoka, Gen Sugita, Muneki Hotomi
Head and neck cancers are the 6th most common cancer type in human malignant tumors and treated with chemoradiotherapy and surgery. Chemotherapy during these treatment modalities leads to damage of intestinal epithelial barriers and results in translocation of intestinal bacteria in bloodstream through invasion in these damaged regions. In this report, we report two cases of hypopharyngeal cancer patients, both of whom received chemotherapy before surgery. The patients demonstrated repeated sepsis before and after surgery, supporting translocation of intestinal bacteria...
November 2018: Medical Hypotheses
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"