399 research outputs found
Origins of Bipedalism
The following manuscript reviews various theories of bipedalism and provides
a holistic answer to human evolution. There are two questions regarding
bipedalism: i) why were the earliest hominins partially bipedal? and ii) why
did hominins become increasingly bipedal over time and replace their less
bipedal ancestors? To answer these questions, the prominent theories in the
field, such as the savanna-based theory, the postural feeding hypotheses, and
the provisioning model, are collectively examined. Because biological evolution
is an example of trial and error and not a simple causation, there may be
multiple answers to the evolution of bipedalism. The postural feeding
hypothesis (reaching for food/balancing) provides an explanation for the
partial bipedalism of the earliest hominins. The savannah-based theory
describes how the largely bipedal hominins that started to settle on the ground
became increasingly bipedal. The provisioning model (food-gathering/monogamy)
explains questions arising after the postural feeding hypothesis and before the
savannah theory in an evolutionary timeline. Indeed, there are no straight
lines between the theories, and multiple forces could have pushed the evolution
of bipedalism at different points. Finally, this manuscript states that the
arboreal hominins that possessed ambiguous traits of bipedalism were eliminated
through choice and selection. Using the biological analogy of the okapi and
giraffe, I explain how one of the branches (Homo) became increasingly bipedal
while the other (Pan) adapted to locomotion for forest life by narrowing the
anatomical/biological focus in evolution
Recurrent True Brachial Artery Aneurysm
True aneurysm of the brachial artery is a rare disease entity. The mechanism of aneurysm formation is considered to be compression of the arterial wall, producing contusion of the media and subsequent weakness of the wall and fusiform dilatation. It can be caused by arteriosclerotic, congenital, and metabolic disorders, and can be associated with diseases such as Kawasaki's disease. Doppler ultrasonography, computed tomography, arteriography, and selective upper extremity angiography may be performed for establishing the diagnosis of aneurysm. The best therapeutic option is operative repair, and it should be performed without any delay, in order to prevent upper extremity ischemic or thrombotic sequelae. Here, we report a case of recurrent brachial artery aneurysm with review of the literature
Photoplethysmogram measurement without direct skin-to-sensor contact using an adaptive light source intensity control
We developed a chair-attached, nonintrusive photoplethysmogram
(PPG)measuring system for everyday life, unconstrained monitoring
using nonskin-contacting sensor-amplifier circuits capable of emitting
suitable light intensity adaptable to clothing characteristics. Comparison
between proposed and conventional systems showed reasonable correlation
and root-mean-squared error levels, indicating its feasibility for unconstrained
PPG monitoring.This work
was supported by a grant from the Advanced Biometric Research Center of
the Korea Science and Engineering Foundation and the Strategic Technology
Development Program funded by the Ministry of Knowledge Economy, Korea
Treatment of Keratoacanthoma with 5% Imiquimod Cream and Review of the Previous Report
Keratoacanthoma (KA) is a benign epidermal tumor, characterized by rapid and abundant growth, a tendency toward spontaneous regression and histopathologic similarity to squamous cell carcinoma (SCC). Because KA can be easily misdiagnosed as SCC, surgery is considered the treatment of choice. Recently, regression of KAs following application of 5% imiquimod cream (Aldara®) has been reported. We present 4 cases of KA treated with topical imiquimod, applied 3 to 4 times a week. Obvious improvement was observed after 4 to 6 weeks of application and the lesions were almost cleared leaving scars after 9 to 11 weeks. These results show that topical imiquimod can be an effective option for the conservative management of KA as previously reported. We also suggest that lesions treated with imiquimod cream should be considered for biopsy to judge histopathological remission after 5 to 8 weeks of application to shorten the duration of the treatment
Dietary Glucose Consumption Promotes RALDH Activity in Small Intestinal CD103(+)CD11b(+) Dendritic Cells
Retinal dehydrogenase (RALDH) enzymatic activities catalyze the conversion of
vitamin A to its metabolite Retinoic acid (RA) in intestinal dendritic cells (DCs)
and promote immunological tolerance. However, precise understanding of the exogenous
factors that act as initial trigger of RALDH activity in these cells is still
evolving. By using germ-free (GF) mice raised on an antigen free (AF) elemental
diet, we find that certain components in diet are critically required to establish
optimal RALDH expression and activity, most prominently in small intestinal
CD103(+)CD11b(+) DCs (siLP-DCs) right from the beginning of their lives.
Surprisingly, systematic screens using modified diets devoid of individual dietary
components indicate that proteins, starch and minerals are dispensable for this
activity. On the other hand, in depth comparison between subtle differences in
dietary composition among different dietary regimes reveal that adequate glucose
concentration in diet is a critical determinant for establishing RALDH activity
specifically in siLP-DCs. Consequently, pre-treatment of siLP-DCs, and not
mesenteric lymph node derived MLNDCs with glucose, results in significant
enhancement in the in vitro generation of induced Regulatory T (iTreg) cells. Our
findings reveal previously underappreciated role of dietary glucose concentration in
establishing regulatory properties in intestinal DCs, thereby extending a potential
therapeutic module against intestinal inflammation11Ysciescopu
Barrier protection via Toll-like receptor 2 signaling in porcine intestinal epithelial cells damaged by deoxynivalnol
Additional file 2. IPEC-J2 cells pretreated with TLR2 ligand maintained the expression of MCP-1, GM-CSF and TLR2 against DON exposure. IPEC-J2 cells pretreated with or without TLR2 ligand for 24 h were exposed to DON. (A) The bar graph showed the mRNA levels of porcine mcp-1, gm-csf measured using real time-PCR at 1 and 6 h after DON exposure (n = 3). (B) The mRNA levels of porcine tlr2 were measured using real-time quantitative PCR analysis at 6 h. NT represents no treatment. Expression of each mRNA was presented relative to the expression of housekeeping gene, gapdh (n = 3). *P < 0.05; **P < 0.01; ***P < 0.001, determined by one-way ANOVA with Tukey’s posttest
Low Concentration PM Had No Effect on Nasal Symptoms and Flow in Allergic Rhinitis Patients
Objectives Since Korea is geographically close to China (the origin site for Asian sand dust [ASD]) the health influence of ASD event will be still greater in Korea. We aimed to evaluate the effect of PM10 (particulate matter with aerodynamic diameter 100 μg/m3) Results There was no significant difference between group A and B in nasal symptoms and PNIF during the 120-day period. Changes in nasal symptoms and PNIF were not statistically significant before or after a PM10 concentration rise above 100 μg/m3. Conclusion Low concentration PM10 does not have significant effect on nasal symptoms and PNIF in AR patients
Fatal Biliary-Systemic Air Embolism during Endoscopic Retrograde Cholangiopancreatography: A Case with Multifocal Liver Abscesses and Choledochoduodenostomy
We report a rare case of a massive fatal embolism that occurred in the middle of endoscopic retrograde cholangiopancreatography (ERCP) and retrospectively examine the significant causes of the event. The patient was a 50-year old female with an uncertain history of previous abdominal surgery for multiple biliary stones 20 years prior. The patient presented with acute right upper quadrant pain. An abdominal computed tomographic (CT) scan revealed the presence of multiple stones in the common bile duct (CBD) and intra-hepatic duct (IHD) with biliary obstruction, multifocal liver abscesses, and air-biliarygram. Emergency ERCP showed a wide and straight opening of choledochoduodenostomy, which may have been created during a previous surgery, and multiple filling defects in the CBD. With the use of a forward endoscope, mud stones were extracted through the opening of the choledochoduodenostomy. Cardiac arrest suddenly developed during the procedure, and despite immediate resuscitation, the patient died due to a massive systemic air embolism. We reviewed previously reported fatal cases and accessed factors facilitating air embolisms in this case
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