Role of L-selectin on leukocytes in the binding of sialic acids on sperm surface during the phagocytosis of sperm in female reproductive tract
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 generallyconsidered to be one of the most important barriers, but the mechanism of the phagocytosis of sperm remains unclear. (Source: Medical Hypotheses)
Source: Medical Hypotheses - August 10, 2018 Category: Biomedical Science Authors: Lin Yu, Yayun Zheng, Ying Feng, Fang Ma Source Type: research
Why does a steep caudal-rostral gradient exist in glycine content in the brain?
Glycine is an important amino acid in the central nervous system. Interestingly, the content of glycine is about 9 times higher in the spinal cord grey matter than in the telencephalon. And this kind of caudal to rostral gradient is never seen in any other neurotransmitters. However, the cause of this phenomenon remains unknown. In the present report, I, thus, postulate the following theory. Glycine has dual roles as a neurotransmitter, one is the agonist for inhibitory glycine receptors (GlyRs), and the other is a co-agonist for excitatory NMDA receptors (NMDARs). (Source: Medical Hypotheses)
Source: Medical Hypotheses - August 9, 2018 Category: Biomedical Science Authors: Kohji Sato Source Type: research
Noninvasive determination of the pulmonary artery input impedance
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. (Source: Medical Hypotheses)
Source: Medical Hypotheses - August 9, 2018 Category: Biomedical Science Authors: Fabijan Luli ć, Zdravko Virag, Marko Jakopović, Ivan Korade Source Type: research
‘Give-up-itis’ revisited: Neuropathology of extremis
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 cl inical 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 p rogression of give-...
Source: Medical Hypotheses - August 9, 2018 Category: Biomedical Science Authors: John Leach Source Type: research
The Pertussis Hypothesis: Bordetella pertussis Colonization in the Etiology of Asthma and Diseases of Allergic Sensitization
Decades of peer reviewed evidence demonstrate that: 1)Bordetellapertussisand pertussis toxin are potent adjuvants, inducing asthma and allergic sensitization in animal models of human disease, 2)Bordetella pertussisoften colonizes the human nasopharynx, and is well documented in highly pertussis-vaccinated populations and 3) in children, a history of whooping cough increases the risk of asthma and allergic sensitization disease. We build on these observations with six case studies and offer a pertussis-based explanation for the rapid rise in allergic disease in former East Germany following the fall of the Berlin Wall; the...
Source: Medical Hypotheses - August 9, 2018 Category: Biomedical Science Authors: Keith Rubin, Steven Glazer Source Type: research
Intermittent living; the use of ancient challenges as a vaccine against the deleterious effects of modern life A hypothesis
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...
Source: Medical Hypotheses - August 8, 2018 Category: Biomedical Science Authors: Leo Pruimboom, Frits A.J. Muskiet Source Type: research
Visceral theory of sleep and origins of mental disorders
Visceral theory of sleep states that the same brain neurons, which process exter- nal 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. (Source: Medical Hypotheses)
Source: Medical Hypotheses - August 7, 2018 Category: Biomedical Science Authors: Mariam M. Morchiladze, Tamila K. Silagadze, Zurab K. Silagadze Source Type: research
Postulating the Major Environmental Condition Resulting in the Expression of Essential Hypertension and Its Associated Cardiovascular Diseases: Dietary Imprudence in Daily Selection of Foods in Respect of Their Potassium and Sodium Content Resulting in Oxidative Stress-Induced Dysfunction of the Vascular Endothelium, Vascular Smooth Muscle, and Perivascular Tissues
We hypothesize that the major environmental determinant of the expression of essential hypertension in America and other Westernized countries is dietary imprudence in respect of the consumption of daily combinations of foods containing suboptimal amounts of potassium and blood pressure-lowering phytochemicals, and supraphysiological amounts of sodium. We offer as premise that Americans on average consume suboptimal amounts of potassium and blood pressure-lowering phytochemicals, and physiologically excessive amounts of sodium, and that such dietary imprudence leads to essential hypertension through oxidative stress-induce...
Source: Medical Hypotheses - August 6, 2018 Category: Biomedical Science Authors: Anthony Sebastian, Loren Cordain, Lynda Frassetto, Tanushree Banerjee, R. Curtis Morris Source Type: research
Copper as the most likely pathogenic divergence factor between lung fibrosis and emphysema
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. (Source: Medical Hypotheses)
Source: Medical Hypotheses - August 6, 2018 Category: Biomedical Science Authors: Rob Janssen, Bart de Brouwer, Jan H. von der Th üsen, Emiel F.M. Wouters Source Type: research
Could reflex cough induced through nebulized capsaicin achieve airway clearance in patients with acute retention of lung secretions?
Nasotracheal suctioning (NTS) is a procedure commonly performed by respiratory physiotherapists and nurses to remove excess respiratory secretions from the tracheobronchial tree in a self-ventilating, non-intubated and non-tracheotomized patient. NTS is an important treatment modality for patients with acute secretion retention who are at high risk of progressive respiratory deterioration and arrest. However, NTS is a blind invasive procedure with risk of serious adverse events, and the patient experience of NTS is often extremely negative. (Source: Medical Hypotheses)
Source: Medical Hypotheses - August 6, 2018 Category: Biomedical Science Authors: S.T. Kulnik Source Type: research
Conceptual challenges for the emergence of the biological system: cell theory and self-replication
We re-evaluate research relating to the current theories of the emergence of biological systems. The challenge being that research programmes concerning the emergence of these systems are viewed as the same as those relating to the origin of cells. Cells are strikingly important biological entities, hard wired into the entire field of biology. The development of biological systems took place much earlier than the origin of cells and even before the existence of the Last Universal Common Ancestor (LUCA); a period which could be construed as being preLUCA and which would have taken place during in a ribonucleoprotein world. ...
Source: Medical Hypotheses - July 30, 2018 Category: Biomedical Science Authors: Francisco Prosdocimi, Sohan Jheeta, S ávio Torres de Farias Source Type: research
Carcinogenesis is consequence of failure of tissue development
Cancer has become a public health problem. The exploration of pathogenesis and therapy of cancer is mainly under the guidance of gene mutation theory. But the therapeutic effect of cancer is not satisfactory, and many predictions of gene mutation theory do not conform actual phenomena of cancer. The research results of mechanism of genetic molecular mutation trap us in an intricate molecular maze hopelessly. The dilemma compels us to doubt about the correctness of gene mutation theory and re-understand the nature of tumor. (Source: Medical Hypotheses)
Source: Medical Hypotheses - July 27, 2018 Category: Biomedical Science Authors: Shaoqing Lai Source Type: research
A plausible causal relationship between the increased use of fentanyl as an obstetric analgesic and the current opioid epidemic in the US
We present the hypothesis that this effect is also true of the opioid, fentanyl: there is a causal relationship between the increased popularity of fentanyl as a labor anesthetic in the United States since the 1980 ’s and the current epidemic of fentanyl abuse. (Source: Medical Hypotheses)
Source: Medical Hypotheses - July 27, 2018 Category: Biomedical Science Authors: Kajsa Brimdyr, Karin Cadwell Source Type: research
A new hypothesis for the pathophysiology of complex regional pain syndrome
Complex Regional Pain Syndrome (CRPS) has defied a clear unified pathological explanation to date. Not surprisingly, treatments for the condition are limited in number, efficacy and their ability to enact a cure. Whilst many observations have been made of physiological abnormalities, how these explain the condition and who does and doesn ’t develop CRPS remains unclear. We propose a new overarching hypothesis to explain the condition that invokes four dynamically changing and interacting components of tissue trauma, pathological pain processing, autonomic dysfunction (both peripheral and central) and immune dysfunction, ...
Source: Medical Hypotheses - July 27, 2018 Category: Biomedical Science Authors: Marc Russo, Peter Georgius, Danielle M Santarelli Source Type: research
Shame as an evolved basic affect – approaches to it within the Comprehensive Resource Model (CRM)
Shame is an evolved emotional response which requires relational evaluation at a prefrontal cortical level but which has the visceral sensation and defence response impulse of a basic affect. We argue that the severe forms of shame, those residual from traumatic interpersonal experiences, have midbrain and diencephalic components mediating experiences of painful withdrawal while anhedonia is derived from a negatively valenced state of the mesolimbic dopamine system. This specific form of separation distress, with a characteristic sense of exclusion and unworthiness, benefits in treatment from the presence of attachment res...
Source: Medical Hypotheses - July 27, 2018 Category: Biomedical Science Authors: Frank M Corrigan, Elisa Elkin-Cleary Source Type: research
