Abstract:
:Doppler sonography is used as a routine test for detection of renal artery stenosis (RAS). Although increased peak systolic velocity at the site of the narrowing is a widely accepted method for assessing main renal artery stenosis, tardus parvus phenomenon detected on the downstream blood flow has been used as an alternative to direct insonation of the main artery. However, the uncertainty about the best Doppler parameter to be used for characterization of tardus parvus has yielded a variety of studies. Recently, the difference between the resistive index of the spleen and kidney (RISK) has been proposed as a potential marker of kidney damage and Doppler criterion for RAS in hypertensive patients without chronic kidney disease (CKD). The hypothesis of this study was to speculate further and propose the RISK as valuable new Doppler diagnostic criteria for the tardus parvus in CKD too. Data from 183 control patients and 135 chronic kidney disease patients (CKD) were included in the study to test the feasibility of the method and plausibility of the hypothesis. Criteria inclusion was a color Doppler ultrasound measurement of the renal (RRI) and spleen resistive index (SRI). Serum creatinine (0.83 ± 0.20 vs 3.27 ± 1.74), RRI (0.60 ± 0.06 vs 0.69 ± 0.09), SRI (0.55 ± 0.06 vs 0.58 ± 0.09), RISK (0.06 ± 0.04 vs 0.11 ± 0.08), and spleen size (94.1 ± 13.2 vs 100.8 ± 16.5) were higher in CKD patients (p < 0.05). RRI correlated with SRI in both groups; however, the coefficient of determination was different (Z = 2.29, p = 0.022). In the CKD group, RISK correlated inversely with age (r = -0.276; p = 0.001) and positively with creatinine (r = 0.509; p < 0.001). In the multivariate analysis, creatinine remained an independent predictor of the high RISK (Wald = 13.07; p < 0.001; odds ratio = 1.87; 95% confidence interval 1.33-2.62). Since extraneous factors similarly influence RRI and SRI, the SRI can be considered the correction factor that can estimate the cardiovascular burden on the RRI. Consequently, according to the suggested hypothesis, RISK helps to distinguish the tardus parvus related to RAS from tardus parvus related to systemic influences on Doppler morphology. The identification of the underlying mechanisms of tardus parvus, would help a more accurate characterization of the phenomenon and improve screening and diagnostic test for RAS in CKD patients.
journal_name
Med Hypothesesjournal_title
Medical hypothesesauthors
Cavalcante Araújo Ndoi
10.1016/j.mehy.2019.01.016subject
Has Abstractpub_date
2019-03-01 00:00:00pages
1-6eissn
0306-9877issn
1532-2777pii
S0306-9877(18)30998-8journal_volume
124pub_type
杂志文章abstract::This article reviews the biochemical and physiological observations underpinning the synergism between ghrelin and ghrelin agonists with exercise, especially progressive resistance training that has been shown to increase muscle mass. The synergy of ghrelin agonists and physical exercise could be beneficial in conditi...
journal_title:Medical hypotheses
pub_type: 杂志文章,评审
doi:10.1016/j.mehy.2015.09.008
更新日期:2015-12-01 00:00:00
abstract::Acute carbon monoxide (CO) poisoning causes the neurologic symptoms and brain lesions during both acute and delayed phase. We propose that catecholamine crises in globus pallidus and deep white matter are the key pathophysiological factors causing acute and delayed brain injuries respectively. Increased sympathetic ac...
journal_title:Medical hypotheses
pub_type: 杂志文章
doi:10.1016/j.mehy.2014.04.032
更新日期:2014-08-01 00:00:00
abstract::Dementia and other causes of functional disability can create considerable burdens for families and society as a whole, but it may be possible to partially alleviate this strain through technical innovations that replace some functions of human caregivers. This article proposes the hypothesis that cell phones, interne...
journal_title:Medical hypotheses
pub_type: 杂志文章
doi:10.1016/j.mehy.2005.11.045
更新日期:2006-01-01 00:00:00
abstract::Fissured tongue (FT) is a condition frequently seen in the general population. Clinically, FT is characterized by grooves that vary in depth and are noted along the dorsal and/or dorsolateral aspects of the tongue. Furthermore, FT presents many enlarged, smooth filiform papillae and subepithelial inflammatory infiltra...
journal_title:Medical hypotheses
pub_type: 杂志文章
doi:10.1016/j.mehy.2014.03.010
更新日期:2014-06-01 00:00:00
abstract::Endemic cancer of the oesophagus in Africa is associated with the use of maize as the staple. In one African community endemic cancer of the oesophagus has been shown to have a strong statistical association with the consumption of foods based on maize in the meal form. A strong association with consumption of maize m...
journal_title:Medical hypotheses
pub_type: 杂志文章
doi:10.1016/j.mehy.2006.05.037
更新日期:2006-01-01 00:00:00
abstract::Preliminary but increasing evidence suggests that attention-deficit/hyperactivity disorder (ADHD), Tourette's syndrome (TS), and restless legs syndrome (RLS) may be comorbid. In the present article, we hypothesize that ADHD, TS, and RLS may be part of a spectrum, and that iron deficiency contributes to the pathophysio...
journal_title:Medical hypotheses
pub_type: 杂志文章
doi:10.1016/j.mehy.2007.10.013
更新日期:2008-01-01 00:00:00
abstract::A comparison of more important physical, chemical and biological properties of the nitric oxide (NO) and free stable nitroxyl radicals (nitroxides) on the base of their structural similarity is made in the article. The active moiety in the nitroxide molecule represents a sterically hindered nitric oxide. The mechanism...
journal_title:Medical hypotheses
pub_type: 杂志文章
doi:10.1054/mehy.2001.1284
更新日期:2001-09-01 00:00:00
abstract::Epidemiological studies reveal that chronic alcoholics exhibiting liver disease are generally malnourished. Experimental studies unequivocally demonstrate that incidence of malnutrition cannot be avoided in animals fed liquid diets containing high concentrations of alcohol. Furthermore, ingestion of additional amounts...
journal_title:Medical hypotheses
pub_type: 杂志文章
doi:10.1016/0306-9877(94)90087-6
更新日期:1994-02-01 00:00:00
abstract::A general theory of neural circuitry is proposed wherein neural impulses travel in a continuous circuit from the brain to the extremities and back to the brain. At the extremities the impulse may be modified by the environment there. At the spinal column the return signal is compared with the outgoing signal and the a...
journal_title:Medical hypotheses
pub_type: 杂志文章
doi:10.1016/0306-9877(94)90002-7
更新日期:1994-05-01 00:00:00
abstract::Extracts of the unripe fruit of Momordica charantia--bitter melon, which flourishes throughout the tropics--appear to have utility in the management of type 2 diabetes. Rodent studies suggest that the thus-far-uncharacterized active components of such extracts enhance the efficiency of postprandial glucose storage in ...
journal_title:Medical hypotheses
pub_type: 杂志文章
doi:10.1016/j.mehy.2004.01.041
更新日期:2004-01-01 00:00:00
abstract::COVID-19 exacts a disproportionate toll on both the elderly and those with diabetes; these patients are more likely to require costly intensive care, longer hospitalisation, and die from complications. Nations would thus find it extremely difficult to either lift or sustain socially, economically, and politically dama...
journal_title:Medical hypotheses
pub_type: 杂志文章
doi:10.1016/j.mehy.2020.110374
更新日期:2021-01-01 00:00:00
abstract::Regulation of ion transport across the airway mucosa may be involved in the mechanisms producing hyperreactivity and asthma. Atrial Natriuretic Peptide (ANP) has been proposed to participate in the pathogenesis of asthma, and it has been found to have a bronchodilatory effect on asthmatic patients. Experimental eviden...
journal_title:Medical hypotheses
pub_type: 杂志文章
doi:10.1016/0306-9877(91)90167-w
更新日期:1991-09-01 00:00:00
abstract::The CoV-19 infection appears to be unusual among patients with type 1 Diabetes Mellitus, although they are considered a fragile population. We think that this in part due to the peculiar immune condition that leads to the destruction of the Beta cells. ...
journal_title:Medical hypotheses
pub_type: 信件
doi:10.1016/j.mehy.2020.109795
更新日期:2020-09-01 00:00:00
abstract::Migraine is frequently assumed to have an hereditary origin, but what this hereditary factor is, no one really knows. Researchers are currently trying to find defects in genes which could either cause, or tend towards, the development of migraine. This approach is deemed mistaken for two reasons: firstly, pain, being ...
journal_title:Medical hypotheses
pub_type: 杂志文章
doi:10.1016/s0306-9877(02)00176-7
更新日期:2002-09-01 00:00:00
abstract::Cancer is the second cause of death worldwide, but current therapies are often insufficient or linked with toxicity. Initial evidence in scientific literature seems to support the role of non-pharmacological strategies, including hypoglycemia, in cancer treatment. The biological rationale for hypoglycemia-based treatm...
journal_title:Medical hypotheses
pub_type: 杂志文章
doi:10.1016/j.mehy.2019.109276
更新日期:2019-09-01 00:00:00
abstract::The aim was to search for periodical fluctuations in daily occurrence of gout attacks during the synodic lunar cycle. 126 gout attacks were recorded between 1972 and 1994 at known calendar dates. The synodic plexogram, displaying the number of attacks for each day of the cycle, was processed by cosinor regression. A p...
journal_title:Medical hypotheses
pub_type: 杂志文章
doi:10.1054/mehy.1999.0973
更新日期:2000-07-01 00:00:00
abstract::Epidural haematoma in newborn infants is rare, and few specific obstetrical data related to its formation are available in the literature. The aim of this study is to discuss the pathophysiology of this condition. EDH is always a post traumatic lesion and it is only possible if the insult has produced a cleavage of th...
journal_title:Medical hypotheses
pub_type: 杂志文章
doi:10.1016/j.mehy.2005.08.045
更新日期:2006-01-01 00:00:00
abstract::Puberty is starting earlier than ever before and there are serious physiological and sociological implications as a result of this development. Current research has focused on the potential role of high caloric, and commensurate high adiposity, contributions to early puberty. However, girls with normal BMI also appear...
journal_title:Medical hypotheses
pub_type: 杂志文章
doi:10.1016/j.mehy.2015.06.029
更新日期:2015-10-01 00:00:00
abstract::Functional, excessive-possibly temporary-deficiencies of the trace element zinc can change immune functions prematurely from predominantly cellular Th1 responses to humoral Th2 responses. T helper (Th1) cells produce cytokines such as interleukin-2 (IL-2) and interferon gamma, thereby controlling viral infections and ...
journal_title:Medical hypotheses
pub_type: 杂志文章
doi:10.1016/s0306-9877(97)90244-9
更新日期:1997-07-01 00:00:00
abstract::Dental caries, a bacterial process that results in the acidic destruction of tooth structure, has historically been managed by the mechanical excavation of diseased tooth structure and then restoration with a synthetic material. The mechanical excavation of the infected site is most commonly achieved by a dental handp...
journal_title:Medical hypotheses
pub_type: 杂志文章
doi:10.1016/j.mehy.2011.05.002
更新日期:2011-09-01 00:00:00
abstract::The number of patients with diabetes has been expected around 300 million by 2025 and 366 million by 2030 by WHO. On the other hand, diabetic wounds as one of the common complications of diabetes represent major health challenges. Recently, wound care biological products have been proposed for treatment of chronic wou...
journal_title:Medical hypotheses
pub_type: 杂志文章
doi:10.1016/j.mehy.2015.03.004
更新日期:2015-06-01 00:00:00
abstract::In a previous paper, I have proposed that the deficiency of an endogenous caffeine-like substance is the underlying pathogenic mechanism in schizophrenia (1). In the present paper, my new concept is used to explain many of the clinical, biochemical, radiologic and pharmacologic facts about schizophrenia. ...
journal_title:Medical hypotheses
pub_type: 杂志文章
doi:10.1016/0306-9877(91)90261-v
更新日期:1991-10-01 00:00:00
abstract::Down-regulation of hormonal effects is in the presented simulation related to the number of functional receptors and quantity of available hormonal stimulation. The former is in the model substituted with the quantity of stimulation able to produce a full down-regulation (Hs100) of target cells. The halftime (t1/2) of...
journal_title:Medical hypotheses
pub_type: 杂志文章
doi:10.1016/s0306-9877(96)90239-x
更新日期:1996-03-01 00:00:00
abstract::In 1937, Drs. Moritz and Oldt described arteriolar injuries in the kidneys (and other viscera) in hypertension, across the age range, in both sexes, and, in different races. This hypothesis proposes that injuries to vasomotor nerves cause the arteriolar injury in the kidney in hypertension, (as well as that in the ute...
journal_title:Medical hypotheses
pub_type: 历史文章,杂志文章
doi:10.1016/j.mehy.2017.12.025
更新日期:2018-02-01 00:00:00
abstract::Placebo controlled trials in disease states as currently constituted are designed to show a drug "works" when in fact it may not. Efficacy of this type may be constructed in trials that demonstrate some marginal superiority of a drug over placebo in disease states that do not take into account any potentialities of th...
journal_title:Medical hypotheses
pub_type: 社论,历史文章,评审
doi:10.1016/j.mehy.2010.01.038
更新日期:2010-05-01 00:00:00
abstract::In this work a new theory of acoustic signal detection in the inner ear and an experimental explanation of the causes of bifilar cochlear structure was presented. Our innovative approach describes sound detection in a completely different way from the one currently adopted. It requires analyzing the inner ear system i...
journal_title:Medical hypotheses
pub_type: 杂志文章
doi:10.1016/j.mehy.2020.109636
更新日期:2020-02-18 00:00:00
abstract::Incidental pituitary adenoma is the common finding during brain imaging. According to multistep model of pituitary tumourigenesis genetic alterations provide the initiating event that transforms cells while hormones play a role in promoting cell proliferation. Development of pituitary adenoma in a case of excessive hy...
journal_title:Medical hypotheses
pub_type: 杂志文章
doi:10.1016/j.mehy.2006.11.044
更新日期:2007-01-01 00:00:00
abstract::Sepsis is a life-threatening disease requiring rapid diagnosis and treatment. Steroid hormones (e.g., estradiol, dehydroepiandosterone) have been suggested to reduce the hyper-inflammatory response of the immune system and to improve outcome in sepsis. We hypothesize that the impact of steroid hormones on the metaboli...
journal_title:Medical hypotheses
pub_type: 杂志文章
doi:10.1016/j.mehy.2012.05.025
更新日期:2012-09-01 00:00:00
abstract::Growing evidence has indicated the existence of deleterious networks in the brains of neurodegenerative disorders, including Alzheimer's disease. Parkinson's disease, amyotrophic lateral sclerosis and Huntington's disease. The deleterious networks are formed on the basis of the intimate interactions among the key path...
journal_title:Medical hypotheses
pub_type: 杂志文章
doi:10.1016/s0306-9877(96)90071-7
更新日期:1996-10-01 00:00:00
abstract::The presented hypothesis suggests that chronic latent malaria infection prepares the niche where the otherwise feeble HIV coinfection can thrive and cause AIDS. It is suggested that the roots of the HIV outbreak and AIDS pandemic lay in the urbanization processes in Africa that resulted in the eradication of the Anoph...
journal_title:Medical hypotheses
pub_type: 杂志文章
doi:10.1054/mehy.2001.1299
更新日期:2001-10-01 00:00:00