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1.
Cureus ; 16(7): e64045, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-39114200

RESUMO

Early detection of oral cavity malignancies is essential for improving treatment outcomes and patient survival rates. Diagnostic imaging, particularly computed tomography (CT), plays a pivotal role in the early identification and detailed assessment of these malignancies. This comprehensive review explores the advancements in CT imaging and its application in diagnosing oral cavity cancers. It discusses the anatomy and physiology of the oral cavity, the clinical characteristics of common malignancies, and the principles and protocols of CT imaging. The review highlights the diagnostic features of oral malignancies on CT, including distinguishing benign from malignant lesions and staging criteria. Emerging technologies, such as higher-resolution imaging, integration with other modalities, and the potential of artificial intelligence, are examined for their role in enhancing diagnostic accuracy. The clinical implications, challenges, and future directions in the use of CT imaging for oral cavity malignancies are also discussed. This review underscores the importance of continued research and technological advancements in optimizing the use of CT for early detection and effective management of oral cavity cancers.

2.
Cureus ; 16(6): e63072, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-39055478

RESUMO

Assisted reproductive technology (ART) has revolutionized the field of reproductive medicine, offering hope to millions of individuals and couples facing infertility challenges. In recent years, integrating robotics and artificial intelligence (AI) has emerged as a promising avenue for advancing ART. This comprehensive review explores the transformative impact of robotics and AI on ART, examining recent advancements, technological applications, clinical implications, and ethical considerations. Robotics enables precise and minimally invasive procedures, enhancing the efficiency and accuracy of various reproductive techniques such as sperm retrieval, embryo handling, and surgical interventions. Meanwhile, AI offers predictive analytics, personalized treatment protocols, and decision support systems tailored to individual patient needs, optimizing treatment outcomes and expanding access to reproductive care. Key findings highlight the significant advancements made possible by robotics and AI in ART, including improved success rates, reduced risks, and enhanced patient experience. However, challenges such as regulatory considerations, adoption barriers, and ethical dilemmas must be addressed to realize the full potential of these technologies. The transformative impact of robotics and AI on ART is profound, shaping the future of fertility treatment and family-building worldwide. Continued research, interdisciplinary collaboration, and investment are essential to further harness the potential of robotics and AI in advancing reproductive medicine and ensuring accessible, equitable, and effective care for all individuals and couples.

3.
Toxins (Basel) ; 16(7)2024 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-39057951

RESUMO

Triple-negative breast cancer (TNBC), which constitutes 10-20 percent of all breast cancers, is aggressive, has high metastatic potential, and carries a poor prognosis due to limited treatment options. LT-IIc, a member of the type II subfamily of ADP-ribosylating-heat-labile enterotoxins that bind to a distinctive set of cell-surface ganglioside receptors-is cytotoxic toward TNBC cell lines, but has no cytotoxic activity for non-transformed breast epithelial cells. Here, primary TNBC cells, isolated from resected human tumors, showed an enhanced cytotoxic response specifically toward LT-IIc, in contrast to other enterotoxins that were tested. MDA-MB-231 cells, a model for TNBC, were used to evaluate potential mechanisms of cytotoxicity by LT-IIc, which induced elevated intracellular cAMP and stimulated the cAMP response element-binding protein (CREB) signaling pathway. To dissect the role of ADP-ribosylation, cAMP induction, and ganglioside ligation in the cytotoxic response, MDA-MB-231 cells were exposed to wild-type LT-IIc, the recombinant B-pentamer of LT-IIc that lacks the ADP-ribosylating A polypeptide, or mutants of LT-IIc with an enzymatically inactivated A1-domain. These experiments revealed that the ADP-ribosyltransferase activity of LT-IIc was nonessential for inducing the lethality of MDA-MB-231 cells. In contrast, a mutant LT-IIc with an altered ganglioside binding activity failed to trigger a cytotoxic response in MDA-MB-231 cells. Furthermore, the pharmacological inhibition of ganglioside expression protected MDA-MB-231 cells from the cytotoxic effects of LT-IIc. These data establish that ganglioside ligation, but not the induction of cAMP production nor ADP-ribosyltransferase activity, is essential to initiating the LT-IIc-dependent cell death of MDA-MB-231 cells. These experiments unveiled previously unknown properties of LT-IIc and gangliosides in signal transduction, offering the potential for the targeted treatment of TNBC, an option that is desperately needed.


Assuntos
Enterotoxinas , Gangliosídeos , Neoplasias de Mama Triplo Negativas , Humanos , Neoplasias de Mama Triplo Negativas/tratamento farmacológico , Neoplasias de Mama Triplo Negativas/patologia , Neoplasias de Mama Triplo Negativas/metabolismo , Linhagem Celular Tumoral , Gangliosídeos/metabolismo , Enterotoxinas/toxicidade , Feminino , AMP Cíclico/metabolismo , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/metabolismo , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/genética , Transdução de Sinais/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos
4.
Cureus ; 16(5): e60007, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38854288

RESUMO

Central pontine myelinolysis (CPM) is a rare neurological disorder characterized by demyelination within the central portion of the pons. While hyponatremia is a well-known precipitating factor, other etiologies, including medication use, have been reported. We present a case of a 69-year-old male with a history of obsessive-compulsive disorder, stroke, and type 2 diabetes mellitus who developed confusion, altered sensorium, and weakness in all four limbs. An MRI brain imaging revealed characteristic findings suggestive of CPM. Despite normal serum sodium levels, discontinuation of clobazam and quetiapine, medications taken by the patient, led to clinical improvement. This case underscores the importance of considering medication-induced CPM in the differential diagnosis of patients presenting with neurological symptoms, even in the absence of electrolyte abnormalities.

5.
Cureus ; 16(5): e60854, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38910647

RESUMO

Organophosphorus poisoning (OPP) poses a significant threat to human health, necessitating accurate prognostic markers for timely intervention and improved outcomes. This review evaluates the potential of the neutrophil-to-lymphocyte ratio (NLR) as a prognostic indicator in acute organophosphorus poisoning (AOPP). A comprehensive analysis of existing literature reveals that elevated NLR values correlate with increased severity of poisoning and adverse clinical outcomes, including mortality and morbidity. NLR assessment offers valuable prognostic information beyond traditional markers, aiding risk stratification and guiding clinical decision-making. Integration of NLR into clinical practice holds promise for optimizing patient care through the early identification of high-risk individuals and tailored therapeutic interventions. Further research is needed to validate the utility of NLR in larger patient cohorts and standardize its incorporation into clinical guidelines. Leveraging NLR as a prognostic tool can enhance risk stratification, optimize treatment strategies, and ultimately improve outcomes in AOPP.

6.
Cureus ; 16(4): e58165, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38741881

RESUMO

High-sensitivity C-reactive protein (hsCRP) has emerged as a critical biomarker in inflammation, offering insights into various chronic diseases. However, traditional blood-based assays for hsCRP measurement pose limitations regarding invasiveness and cost. In recent years, saliva has garnered attention as an alternative diagnostic medium, presenting a noninvasive and easily accessible option for biomarker analysis. Salivary hsCRP has thus emerged as a promising avenue for research and clinical application, offering potential advantages over blood-based assays. This comprehensive review aims to elucidate the biological basis of salivary hsCRP, its clinical applications, and methodologies for measurement. By exploring its diagnostic potential, prognostic value, and implications for treatment monitoring, this review highlights the potential impact of salivary hsCRP in modern medicine. Moreover, it emphasizes the need for continued exploration, validation, and integration of salivary hsCRP into routine clinical practice to realize its full potential for enhancing patient care and advancing personalized medicine approaches.

7.
Cureus ; 16(4): e57751, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38716007

RESUMO

Systemic lupus erythematosus (SLE) is a chronic autoimmune disorder known for its intricate clinical manifestations, spanning a spectrum of symptoms, including neuropsychiatric SLE (NPSLE) and lupus nephritis (LN). This condition predominantly affects young women of childbearing age, presenting a diverse array of symptoms that pose challenges in both diagnosis and treatment. Diagnosing central nervous system (CNS) involvement in SLE remains notably difficult despite being rooted in an autoimmune inflammatory response driven by cytokine surges. There exists no single definitive test for diagnosis, necessitating a thorough evaluation of clinical presentations, neurological indicators, and specific antibody detection. LN typically evades diagnosis until the patient progresses to a state of advanced renal insufficiency, demanding aggressive therapeutic interventions. In this discourse, we examine a case marked by generalized tonic-clonic seizures. While epilepsy might be initially suspected, in this instance, the underlying cause lay deeper, concealed within the complexities of autoimmune dysregulation. Additional symptoms included generalized edema, sun-exposed rash, oral ulcers, and recurrent fever over the past six months. The puzzle pieces eventually coalesced through meticulous examination of each clinical manifestation, coupled with laboratory analyses, neuroimaging studies, and renal biopsy, revealing a complex scenario of cerebral vasculitis concurrent with LN in a case of SLE.

8.
Cureus ; 16(4): e57821, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38721215

RESUMO

Reversible posterior leukoencephalopathy syndrome, often referred to as posterior reversible encephalopathy syndrome (PRES), is a disorder characterized by acute cerebral dysfunction and is seen in conjunction with vasogenic edema on brain imaging. Headaches, visual issues, seizures, abnormal mentation, disturbances in awareness, and focal neurological symptoms are its defining features. In this case report, we present a 40-year-old male patient who developed PRES after experiencing a high-voltage electric shock.

9.
Cureus ; 16(3): e56254, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38623097

RESUMO

Elizabethkingia meningoseptica is a rare gram-negative bacterium recognized for its propensity to induce hospital-acquired infections, particularly in individuals with compromised immune systems and those equipped with indwelling medical devices. Its notorious resistance to a broad spectrum of antibiotics poses a considerable challenge in treatment protocols, contributing to its emergence as a significant cause of heightened mortality rates among critically ill patients. Herein, we present a case of E. meningoseptica infection in a patient afflicted with end-stage renal disease (ESRD) undergoing maintenance hemodialysis, concurrently grappling with ESRD, and a positive status for hepatitis B. This case report aims to shed light on the intricate complexities involved in diagnosing and managing such infections within this intricate clinical context.

10.
Cureus ; 16(3): e57006, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38681382

RESUMO

The rare yet potentially fatal neurological complication known as posterior reversible encephalopathy syndrome (PRES) can manifest during pregnancy. Alongside symptoms such as headaches, nausea, visual disturbances, and altered mental status, patients often experience seizures or loss of consciousness. Imaging typically reveals vascular edema affecting the parietal and occipital lobes within the subcortical region. We present the case of a 24-year-old patient who developed postpartum eclampsia followed by PRES. MRI findings demonstrated hyperintensities in the posterior parietal, frontal, and occipital lobes bilaterally, confirming the diagnosis. Prompt administration of levetiracetam and labetalol led to the resolution of the patient's symptoms. Subsequently, we thoroughly searched online databases for peer-reviewed articles examining the etiology, clinical presentation, and treatment options for PRES. Our evaluation of the case findings alongside existing literature underscored the rarity of PRES occurring concurrently with postpartum eclampsia, highlighting the importance of timely identification and intervention in managing this condition. Further research is warranted to enhance our understanding of PRES in the context of pregnancy-related complications.

11.
Cureus ; 16(3): e56353, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38633960

RESUMO

Lemierre's syndrome is characterized by internal jugular vein thrombophlebitis and bacteremia, primarily from anaerobic organisms. The condition usually arises after a recent oropharyngeal infection. Young, healthy people with prolonged pharyngitis that progresses into septicemia, pneumonia, or lateral neck stiffness should be suspected of having Lemierre's syndrome. Identifying internal jugular vein thrombophlebitis and developing anaerobic bacterial growth on blood culture are frequently used to confirm the diagnosis. Treatment consists of long-term antibiotic treatment, sometimes in conjunction with anticoagulant medication. In this case report, we describe the unique case of a 29-year-old male with Mycobacterium tuberculosis with pulmonary tuberculosis, tubercular meningitis, tuberculosis-related acute ischemic stroke with septic thrombophlebitis. The patient presented with sudden onset altered sensorium for 4 hours. Magnetic resonance imaging of the brain was done, which suggested obstructive hydrocephalus with periventricular ooze. The patient was started on antibacillary treatment, antibiotics, anticoagulants, and systemic steroids. The patient was vitally stable when he was discharged. Therefore, it is crucial to consider the likelihood of such atypical tuberculosis presentations while providing a prompt and relevant diagnosis and recommending the right course of therapy.

12.
Cureus ; 16(2): e54338, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38500916

RESUMO

There has been a notable rise in instances of multiple-fetus pregnancies over the last decade, attributed to the widespread adoption of assisted reproductive technologies. Moreover, these pregnancies have been associated with the use of drugs to induce ovulation. While some cases involve the loss of one twin with minimal consequences for the surviving twin, the demise of a fetus after the first trimester, especially beyond three months into the pregnancy, can significantly impact the health of both the mother and the surviving fetus. Unfavorable outcomes linked to the loss of one twin after the first trimester include impaired physical growth of the surviving fetus, preterm delivery, neurological abnormalities, and, in certain instances, the death of the surviving twin. This report provides a detailed account of a specific case involving twin pregnancies where a single fetal death occurred at the 24th week of gestation, leading to severe pregnancy-induced hypertension and pulmonary edema. Upon reviewing peer-reviewed articles related to similar cases in online databases, no exact matches were identified for cases with a comparable presentation. The scarcity of literature on the development of pre-eclampsia following the death of a single fetus suggests a gap in obstetric research in this area. Consequently, the uniqueness of this case report arises from its distinctive circumstances and the limited existing literature on the subject within the obstetric community.

13.
Cureus ; 16(1): e52361, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38361716

RESUMO

Klippel-Trenaunay syndrome (KTS) is a rare genetic syndrome comprising an abnormal development of soft tissues and the lymphovascular system with bony overgrowth, venous malformation, and port wine stains. We present an interesting case of a three-year-old child brought to our hospital with a swollen limb and raised skin lesions associated with bleeding from minor trauma. Most of the clinical characteristics of KTS were seen in our patient, including arteriovenous, soft tissue, capillary, and lymphatic abnormalities. The diagnosis of KTS is based on clinical examinations and imaging investigations. He had gross hypertrophy of the left lower limb with measurable lengthening compared to the opposite limb. Ultrasonography of the left limb revealed soft tissue hypertrophy with abnormal venous communication. The management of KTS is mainly symptomatic and should be approached conservatively if the patient has functional limbs without edema, bleeding, ulceration, or pain.

15.
Epidemiol Psychiatr Sci ; 32: e70, 2023 Dec 13.
Artigo em Inglês | MEDLINE | ID: mdl-38086740

RESUMO

AIMS: National policies can be used to reveal structural stigma and discrimination in relation to mental health. This review assesses how structural stigma and discrimination are manifested in the policies and legislations of Government of Nepal. METHODS: Scoping review methodology was followed to review policy documents (acts of parliament, legislation, policies, strategies, guidelines and official directives) drafted or amended after 2010. RESULTS: Eighty-nine policies were identified related to health, social welfare, development and regulations which were relevant to people with psychosocial and mental disabilities or have addressed the mental health agendas. Several critical policy failings and gaps are revealed, such as the use of stigmatizing language (e.g., 'insane' or 'lunatic'), inconsistencies within and between policies, deviation from international protocols defining legal capacity and consent, lack of inclusion of the mental health agenda in larger development policies and lack of cost-effective interventions and identification of financing mechanisms. Provisions for people living with mental health conditions included adequate standard of living; attaining standard mental health; the right to exercise legal capacity, liberty and security; freedom from torture or discrimination; and right to live independently. However, other policies contradicted these rights, such as prohibiting marriage, candidacy for and retention of positions of authority and vulnerability to imprisonment. CONCLUSION: Mental health-related structural stigma and discrimination in Nepal can be identified through the use of discriminator language and provisions in the policies. The structural stigma and discrimination may be addressed through revision of the discriminating policies, integrating the mental health agenda into larger national and provincial policies, and streamlining policies to comply with national and international protocols.


Assuntos
Saúde Mental , Estigma Social , Humanos , Nepal , Política Pública
16.
Kathmandu Univ Med J (KUMJ) ; 21(81): 58-63, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37800427

RESUMO

Background Although Nephrolithiasis is a common condition caused by a wide variety of metabolic or environmental disturbances, its being one of the major factor of morbidity. Incidence of kidney stone disease (KSD) is highly affected by metabolic disorders and change in blood pressure and glucose. Objective To find out association of different biochemical and hemodynamic parameters with various glycemic status and hypertension in kidney stone disease. Method A cross sectional study was conducted in patients diagnosed as nephrolithiasis by using re¬nal ultrasonography and underwent nephrectomy between January 2019 to January 2021 in Shahid Dharmabhakta National Transplant Centre (SDNTC). A total of 100 subjects with 60 male and 40 females were enrolled. Glycemic status was categorized based on criteria of American Diabetes Association (ADA) and hypertension was defined as BP ≥ 140/90 mm Hg in right arm supine position. All biochemical and hemodynamic profile was carried out following standard protocol. Result Out of 100 patients enrolled, pre-diabetes accounted for 31% followed by diabetes (4%). However, hypertension comprised of 66% in total subjects. Serum urea, cholesterol and triglyceride level were found to be increased by 84.6%, 67.7% and 64.7% respectively in diabetes followed by increase of 3.9%, 19.5% and 3.1% respectively in prediabetes when compared to normal glycemic condition in nephrolithiasis subjects. Serum fasting blood glucose, creatinine and uric acid level was observed significantly higher (p=0.003, p=0.004, p < 0.001 respectively) in hypertensive patients. Duration of hospital stay was also seen positively correlated with hypertension. Conclusion Not only diabetes, prediabetes also manifests the increased risk of kidney stone disease along with hypertension. There is significant impairment in renal function and lipid profile based on diabetes mellitus and hypertension. Early identifying these systemic diseases, different biochemical and hemodynamic parameters and proper treatment accordingly may minimize risk and prevent serious complication in these patients.


Assuntos
Diabetes Mellitus Tipo 2 , Diabetes Mellitus , Hipertensão , Cálculos Renais , Estado Pré-Diabético , Feminino , Humanos , Masculino , Diabetes Mellitus Tipo 2/complicações , Estado Pré-Diabético/complicações , Estudos Transversais , Hipertensão/complicações , Cálculos Renais/complicações , Cálculos Renais/epidemiologia , Pressão Sanguínea
17.
J Obstet Gynaecol India ; 73(4): 295-300, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37701084

RESUMO

In the past few years almost every aspect of an IVF cycle has been investigated, including research on sperm, color doppler in follicular studies, prediction of embryo cleavage, prediction of blastocyst formation, scoring blastocyst quality, prediction of euploid blastocysts and live birth from blastocysts, improving the embryo selection process, and for developing deep machine learning (ML) algorithms for optimal IVF stimulation protocols. Also, artificial intelligence (AI)-based methods have been implemented for some clinical aspects of IVF, such as assessing patient reproductive potential and individualizing gonadotropin stimulation protocols. As AI has the inherent capacity to analyze "Big" data, the goal will be to apply AI tools to the analysis of all embryological, clinical, and genetic data to provide patient-tailored individualized treatments. Human skillsets including hand eye coordination to perform an embryo transfer is probably the only step of IVF that is outside the realm of AI & ML today. Embryo transfer success is presently human skill dependent and deep machine learning may one day intrude into this sacred space with the advent of programed humanoid robots. Embryo transfer is arguably the rate limiting step in the sequential events that complete an IVF cycle. Many variables play a role in the success of embryo transfer, including catheter type, atraumatic technique, and the use of sonography guidance before and during the procedure of embryo transfer. In contemporary Reproductive Medicine human beings are not yet dispensable.

18.
Mymensingh Med J ; 32(2): 556-566, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37002771

RESUMO

During the COVID-19 pandemic, elderly people have been more prone to depression, anxiety and stress. During these trying times, they require more attention and support for their mental health. This cross-sectional study was performed with the duration of 06 months from March 2021 to August 2021 in AIIMS, Bhopal in the state of Madhya Pradesh, in central India. And the participants recruited by systematic random sampling from a population aged more than 60 years, those who were able to read and write Hindi or English and having at least one family member; who reported to AIIMS, Bhopal during the second wave of COVID-19 in India. Those who were confirmed COVID-19 cases and undergoing treatment for the same, with diagnosed mental health disorders and who didn't give consent were excluded. A Google form based online semi-structured questionnaire along with DASS-21 scale was completed by participants. Elderly (>=60 years) will be selected. Of the 690 participants 7.25% reported mild to moderate depression, whereas 0.58 percent had severe or extremely severe depression. Mild to moderate anxiety were found in 9.56% of people, while 2.46% had severe or extremely severe anxiety. Mildly or moderately were stressed 4.78%, while 0.42% was severely or extremely anxious. Alcoholism and depression were found to have a statistically significant relationship (p=0.028). During the COVID-19 pandemic, elderly subjects who napped during the day were substantially less depressed (p=0.033). The older the respondents were, the more nervous they were during the pandemic (p=0.042). There is a link between alcohol consumption and stress (p=0.043) and it was seen that females were more stressed as compared to males (p=0.045). There was a strong correlation between participants' alcohol addiction and depressive symptoms. Psychological therapies for the elderly are thought to be necessary to enhance their psychological resilience and mental health. We need to tackle the stigma related to the COVID-19 and mental health issues.


Assuntos
Ansiedade , COVID-19 , Depressão , Pandemias , Depressão/epidemiologia , Humanos , Idoso de 80 Anos ou mais , Ansiedade/epidemiologia , Idoso , Índia/epidemiologia , COVID-19/psicologia , Masculino , Feminino , Fatores Sexuais , Fatores Etários , Sono , Inquéritos e Questionários , Consumo de Bebidas Alcoólicas
19.
Kathmandu Univ Med J (KUMJ) ; 21(82): 238-240, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38628022

RESUMO

Retroperitoneal mullerian cysts are rare, benign neoplastic cyst of urogenital subtype. They are usually asymptomatic and may present with symptoms if they grow considerably in size with pressure over the adjacent organ or follow infection, hemorrhage or rupture. Histologically, these cyst are lined with benign ciliated columnar epithelium. We present the case of a 30-year-old female with history of abdominal distension and epigastric pain. The mass excised was in retroperitoneal space and microscopic examination revealed benign cyst of mullerian origin.


Assuntos
Cistos , Feminino , Humanos , Adulto , Cistos/diagnóstico , Cistos/cirurgia , Cistos/patologia , Espaço Retroperitoneal/patologia , Dor Abdominal/diagnóstico , Dor Abdominal/etiologia , Dor Abdominal/patologia
20.
J Biol Chem ; 298(12): 102618, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36272647

RESUMO

Heterotrimeric G proteins (αßγ subunits) that are activated by G protein-coupled receptors (GPCRs) mediate the biological responses of eukaryotic cells to extracellular signals. The α subunits and the tightly bound ßγ subunit complex of G proteins have been extensively studied and shown to control the activity of effector molecules. In contrast, the potential roles of the large family of γ subunits have been less studied. In this review, we focus on present knowledge about these proteins. Induced loss of individual γ subunit types in animal and plant models result in strikingly distinct phenotypes indicating that γ subtypes play important and specific roles. Consistent with these findings, downregulation or upregulation of particular γ subunit types result in various types of cancers. Clues about the mechanistic basis of γ subunit function have emerged from imaging the dynamic behavior of G protein subunits in living cells. This shows that in the basal state, G proteins are not constrained to the plasma membrane but shuttle between membranes and on receptor activation ßγ complexes translocate reversibly to internal membranes. The translocation kinetics of ßγ complexes varies widely and is determined by the membrane affinity of the associated γ subtype. On translocating, some ßγ complexes act on effectors in internal membranes. The variation in translocation kinetics determines differential sensitivity and adaptation of cells to external signals. Membrane affinity of γ subunits is thus a parsimonious and elegant mechanism that controls information flow to internal cell membranes while modulating signaling responses.


Assuntos
Subunidades beta da Proteína de Ligação ao GTP , Subunidades gama da Proteína de Ligação ao GTP , Receptores Acoplados a Proteínas G , Animais , Membrana Celular/metabolismo , Subunidades beta da Proteína de Ligação ao GTP/genética , Subunidades beta da Proteína de Ligação ao GTP/metabolismo , Subunidades gama da Proteína de Ligação ao GTP/genética , Subunidades gama da Proteína de Ligação ao GTP/metabolismo , Transdução de Sinais , Receptores Acoplados a Proteínas G/genética , Receptores Acoplados a Proteínas G/metabolismo , Humanos
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