During development and in the context of different morphogenetic events, epithelial cells undergo a process called epithelial to mesenchymal transition or transdifferentiation （EMT）. In this process, the cells lose ...During development and in the context of different morphogenetic events, epithelial cells undergo a process called epithelial to mesenchymal transition or transdifferentiation （EMT）. In this process, the cells lose their epithelial characteristics, including their polarity and specialized cell-cell contacts, and acquire a migratory behavior, allowing them to move away from their epithelial cell community and to integrate into surrounding tissue, even at remote locations. EMT illustrates the differentiation plasticity during development and is complemented by another process, called mesenchymal to epithelial transition （MET）. While being an integral process during development, EMT is also recapitulated under pathological conditions, prominently in fibrosis and in invasion and metastasis of carcinomas. Accordingly, EMT is considered as an important step in tumor progression. TGF-β signaling has been shown to play an important role in EMT. In fact, adding TGF-β to epithelial cells in culture is a convenient way to induce EMT in various epithelial cells. Although much less characterized, epithelial plasticity can also be regulated by TGF-β-related bone morphogenetic proteins （BMPs）, and BMPs have been shown to induce EMT or MET depending on the developmental context. In this review, we will discuss the induction of EMT in response to TGF-β, and focus on the under- lying signaling and transcription mechanisms.展开更多
Here, we report a case of a young man who presented with a significant upper gastrointestinal bleed treated by endoscopic removal of multiple hyperplastic polyps. Gastric hyperplastic polyps are a relatively uncommon ...Here, we report a case of a young man who presented with a significant upper gastrointestinal bleed treated by endoscopic removal of multiple hyperplastic polyps. Gastric hyperplastic polyps are a relatively uncommon cause of overt gastrointestinal bleeding. While most hyperplastic gastric polyps are asymptomatic, they may present with abdominal pain, iron def iciency anemia or gastric outlet obstruction. These polyps are associated with conditions such as Helicobacter pylori gastritis and atrophic autoimmune gastritis, which predispose the epithelium to chronic inf lammation and epithelial repair.The patient presented to Northwestern Memorial Hospital in July 2011. The polyps were resected by clip-assisted snare polypectomy. Histopathologic assessment of the resected polyps demonstrated multiple, nonulcerative hyperplastic polyps measuring 1.3-1.8 cm in size, without evidence of dysplasia or malignancy. This case describes a young adult patient with multiple, large gastric polyps causing overt gastrointestinal bleeding. This is a rare presentation in a young individual, as these polyps are typically identifi ed in patients older than 60 years of age and less commonly, pediatric populations.展开更多
BACKGROUND: AND PURPOSE: The measurement of relative cerebral blood volume (rCBV) and the volume transfer constant (K(trans)) by means of dynamic contrast-enhanced (DCE) perfusion MR imaging (pMRI) can be useful in ch...BACKGROUND: AND PURPOSE: The measurement of relative cerebral blood volume (rCBV) and the volume transfer constant (K(trans)) by means of dynamic contrast-enhanced (DCE) perfusion MR imaging (pMRI) can be useful in characterizing brain tumors. The purpose of our study was to evaluate the utility of these measurements in differentiating typical meningiomas and atypical meningiomas. METHODS: Fifteen patients with pathologically confirmed typical meningiomas and seven with atypical meningiomas underwent conventional imaging and DCE pMRI before resection.rCBV measurements were calculated by using standard intravascular展开更多
Histopathological reports of multiple sclerosis and its animal models have sh own evidence of a link between axonal injury in active lesions and impaired glut amate metabolism. Mature oligodendrocytes play a role in g...Histopathological reports of multiple sclerosis and its animal models have sh own evidence of a link between axonal injury in active lesions and impaired glut amate metabolism. Mature oligodendrocytes play a role in glutamate uptake to mai ntain glutamate homeostasis but in multiple sclerosis white matter the loss of e xpression of glutamate transporters in the lesion vicinity results in ineffectiv e glutamate removal. Using a magnetic resonance spectroscopy technique that isol ates the glutamate resonance at 3 T, we compared glutamate levels between normal subjects and multiple sclerosis patients in different brain areas. Metabolite c oncentrations (glutamate, glutamine, N- acetyl- aspartate, myo- inositol, cho line, creatine) were derived from LC model and corrected for T1 relaxation time. Glutamate concentrations were found to be elevated in acute lesions (P=0.02) an d normal- appearing white matter (P=0.03), with no significant elevation in chr onic lesions (P=0.77). The N- acetyl- aspartate level in chronic lesions was s ignificantly lower (P < 0.001) than in acute lesions and normal- appearing whit e matter. The choline level in acute lesions was significantly higher (P < 0.001 ) than in chronic lesions. Evidence was also found for increased glial activity in multiple sclerosis, with significantly higher (P < 0.001) myo- inositol leve ls in acute lesions compared with control white matter. These in vivo results su pport the hypothesis that altered glutamate metabolism is present in brains of m ultiple sclerosis patients.展开更多
BACKGROUND Papillary cystadenoma is a rare benign epithelial tumor of the salivary gland,which is characterized by papillary structures and oncocytic cells with rich eosinophilic cytoplasm. We found only one case of p...BACKGROUND Papillary cystadenoma is a rare benign epithelial tumor of the salivary gland,which is characterized by papillary structures and oncocytic cells with rich eosinophilic cytoplasm. We found only one case of papillary cystadenoma in nearly 700 cases of salivary gland tumors. Our case was initially mistaken for a tumor of the right temporomandibular joint(TMJ) capsule rather than of parotid gland origin. Preoperative magnetic resonance imaging(MRI) and computed tomography(CT) should be carefully studied, which allows for appropriate preoperative counseling and operative planning.CASE SUMMARY Here, we report an unusual case of a 54-year-old woman with a parotid gland papillary cystadenoma(PGPC) that was misdiagnosed as a tumor of the right TMJ capsule. She was initially admitted to our hospital due to a mass anterior to her right ear inadvertently found 5 d ago. Preoperative CT and MRI revealed a well circumscribed tumor that was attached to the right TMJ capsule. The patient underwent a resection through an incision for TMJ, but evaluation of an intraoperative frozen section revealed a benign tumor of the parotid gland. Then we removed part of the parotid gland above the temporal facial trunk. The facial nerve was preserved. Postoperative histopathological findings revealed that the tumor was PGPC. No additional treatment was performed. There was no recurrence during a 20-mo follow-up period.CONCLUSION The integrity of the interstitial space around the condyle in MRI or CT should be carefully evaluated for parotid gland or TMJ tumors.展开更多
BACKGROUND Hospital admissions are common among patients with cirrhosis,but patient factors associated with hospitalization have not been well characterized.Given recent data suggesting increased liver transplant wait...BACKGROUND Hospital admissions are common among patients with cirrhosis,but patient factors associated with hospitalization have not been well characterized.Given recent data suggesting increased liver transplant waitlist dropout among women,we hypothesized that women on the liver transplant waitlist would have increased rates of hospitalization compared with men.AIM To evaluate the role of gender on risk of hospitalization for patients on the liver transplant waitlist,in order to help explain gender disparities in waitlist outcomes.METHODS Patients listed for liver transplant at a single center in the United States were prospectively enrolled in the Functional Assessment in Liver Transplantation Study.Patients included in this retrospective analysis included those enrolled between March 2012 and December 2014 with at least 12 mo of follow up and without hepatocellular carcinoma.The primary and secondary outcomes were hospitalization and total inpatient days within 12 mo,respectively.Logistic and negative binomial regression associated baseline factors with outcomes.RESULTS Of the 392 patients,41%were female,with median(interquartile range)age 58 years(52-63)and model for end-stage liver disease 18(15-22).Within 12 mo,186(47%)patients were hospitalized≥1 time;48%were readmitted,with a median of 8(4-15)inpatient days.More women than men were hospitalized(54%vs 43%;P=0.03).In univariable analysis,female sex was associated with an increased risk of hospitalization[odds ratios(OR)1.6,95%confidence interval(CI)1.0-2.4;P=0.03],which remained significant on adjusted multivariable analysis(OR 1.6,95%CI:1.1-2.6;P=0.03).Female gender was also associated with an increased number of inpatient days within 12 mo in both univariable and multivariable regression.CONCLUSION Women with cirrhosis on the liver transplant waitlist have more hospitalizations and inpatient days in one year compared with men,suggesting that the experience of cirrhosis differs between men and women,despite similar baseline illness severity.Future studies should explore gender-specific vulnerabilities to help explain waitlist disparities.展开更多
Although severe and chronic mental disorders are common among Asian Americans in residential treatment programs, little has been known about the prevalence and predictors of co-occurring substance use in this populati...Although severe and chronic mental disorders are common among Asian Americans in residential treatment programs, little has been known about the prevalence and predictors of co-occurring substance use in this population. The purpose of this study was to examine predictors of co-occurring substance use among Asian Americans with mental disorders in residential treatment programs. This cross-sectional study included 375 clinical records of Asian Americans from residential treatment programs between 2007 and 2011. Demographic variables, principal psychiatric diagnoses, and data on alcohol, stimulant, and marijuana use were obtained from the clinical records. Separate binary logistic regression analyses were used to examine the demographic and diagnostic contributions to the risk of each type of substance use. Findings of this study indicated that the prevalence of co-occurring substance use was about 53% in Asian Americans with mental disorders. Binary logistic regression analyses revealed that male gender, older age, and depressive disorder predicted more alcohol use, but homelessness and schizophrenia predicted less alcohol use. Male gender, homelessness, and smoking predicted more stimulant use. Male gender and younger age predicted more marijuana use. Based on the findings of this study, awareness about co-occurring substance use problems of ethnic minority psychiatric clients should be increased and appropriate substance use prevention and treatment programs should be developed and provided for high-risk groups.展开更多
Extracellular-matrix composition impacts mechanical performance in native and engineered tissues.Previous studies showed collagen typeⅠ-agarose blends increased cell-matrix interactions and extracellular matrix produ...Extracellular-matrix composition impacts mechanical performance in native and engineered tissues.Previous studies showed collagen typeⅠ-agarose blends increased cell-matrix interactions and extracellular matrix production.However,long-term impacts on protein production and mechanical properties of engineered cartilage are unknown.Our objective was to characterize the effect of collagen type I on the matrix production of chondrocytes embedded in agarose hydrogels.We hypothesized that the addition of collagen would improve longterm mechanical properties and matrix production(e.g.collagen and glycosaminoglycans)through increased bioactivity.Agarose hydrogels(2%w/v)were mixed with varying concentrations of collagen typeⅠ(0,2 and 5 mg/ml).Juvenile bovine chondrocytes were added to the hydrogels to assess matrix production over 4 weeks through biochemical assays,and mechanical properties were assessed through unconfined compression.We observed a dose-dependent effect on cell bioactivity,where 2 mg/ml of collagen improved bioactivity,but 5 mg/ml had a negative impact on bioactivity.This resulted in a higher modulus for scaffolds supplemented with lower collagen concentration as compared to the higher collagen concentration,but not when compared to the control.In conclusion,the addition of collagen to agarose constructs provided a dose-dependent impact on improving glycosaminoglycan production but did not improve collagen production or compressive mechanics.展开更多
On April 13,2021,the US Centers for Disease Control and Prevention(CDC)and the US Food and Drug Administration(FDA)recommended a pause in administration of the Ad26.COV2.S(Johnson&Johnson[Janssen])coronavirus dise...On April 13,2021,the US Centers for Disease Control and Prevention(CDC)and the US Food and Drug Administration(FDA)recommended a pause in administration of the Ad26.COV2.S(Johnson&Johnson[Janssen])coronavirus disease 2019(COVID-19)vaccine for all persons[1].At that time,approximately 6.8 million doses of vaccine had been administered around the United States.The pause was prompted by 6 cases of cerebral venous sinus thrombosis(CVST)in combination with thrombocytopenia,a condition whose nomenclature is in flux but which we will refer to as thrombosis with thrombocytopenia syndrome(TTS),as used by CDC in describing the condition[2].All patients were women younger than 50 years.Of note,2 of 6 patients also had splanchnic and portal vein thrombosis.展开更多
文摘During development and in the context of different morphogenetic events, epithelial cells undergo a process called epithelial to mesenchymal transition or transdifferentiation （EMT）. In this process, the cells lose their epithelial characteristics, including their polarity and specialized cell-cell contacts, and acquire a migratory behavior, allowing them to move away from their epithelial cell community and to integrate into surrounding tissue, even at remote locations. EMT illustrates the differentiation plasticity during development and is complemented by another process, called mesenchymal to epithelial transition （MET）. While being an integral process during development, EMT is also recapitulated under pathological conditions, prominently in fibrosis and in invasion and metastasis of carcinomas. Accordingly, EMT is considered as an important step in tumor progression. TGF-β signaling has been shown to play an important role in EMT. In fact, adding TGF-β to epithelial cells in culture is a convenient way to induce EMT in various epithelial cells. Although much less characterized, epithelial plasticity can also be regulated by TGF-β-related bone morphogenetic proteins （BMPs）, and BMPs have been shown to induce EMT or MET depending on the developmental context. In this review, we will discuss the induction of EMT in response to TGF-β, and focus on the under- lying signaling and transcription mechanisms.
文摘Here, we report a case of a young man who presented with a significant upper gastrointestinal bleed treated by endoscopic removal of multiple hyperplastic polyps. Gastric hyperplastic polyps are a relatively uncommon cause of overt gastrointestinal bleeding. While most hyperplastic gastric polyps are asymptomatic, they may present with abdominal pain, iron def iciency anemia or gastric outlet obstruction. These polyps are associated with conditions such as Helicobacter pylori gastritis and atrophic autoimmune gastritis, which predispose the epithelium to chronic inf lammation and epithelial repair.The patient presented to Northwestern Memorial Hospital in July 2011. The polyps were resected by clip-assisted snare polypectomy. Histopathologic assessment of the resected polyps demonstrated multiple, nonulcerative hyperplastic polyps measuring 1.3-1.8 cm in size, without evidence of dysplasia or malignancy. This case describes a young adult patient with multiple, large gastric polyps causing overt gastrointestinal bleeding. This is a rare presentation in a young individual, as these polyps are typically identifi ed in patients older than 60 years of age and less commonly, pediatric populations.
文摘BACKGROUND: AND PURPOSE: The measurement of relative cerebral blood volume (rCBV) and the volume transfer constant (K(trans)) by means of dynamic contrast-enhanced (DCE) perfusion MR imaging (pMRI) can be useful in characterizing brain tumors. The purpose of our study was to evaluate the utility of these measurements in differentiating typical meningiomas and atypical meningiomas. METHODS: Fifteen patients with pathologically confirmed typical meningiomas and seven with atypical meningiomas underwent conventional imaging and DCE pMRI before resection.rCBV measurements were calculated by using standard intravascular
文摘Histopathological reports of multiple sclerosis and its animal models have sh own evidence of a link between axonal injury in active lesions and impaired glut amate metabolism. Mature oligodendrocytes play a role in glutamate uptake to mai ntain glutamate homeostasis but in multiple sclerosis white matter the loss of e xpression of glutamate transporters in the lesion vicinity results in ineffectiv e glutamate removal. Using a magnetic resonance spectroscopy technique that isol ates the glutamate resonance at 3 T, we compared glutamate levels between normal subjects and multiple sclerosis patients in different brain areas. Metabolite c oncentrations (glutamate, glutamine, N- acetyl- aspartate, myo- inositol, cho line, creatine) were derived from LC model and corrected for T1 relaxation time. Glutamate concentrations were found to be elevated in acute lesions (P=0.02) an d normal- appearing white matter (P=0.03), with no significant elevation in chr onic lesions (P=0.77). The N- acetyl- aspartate level in chronic lesions was s ignificantly lower (P < 0.001) than in acute lesions and normal- appearing whit e matter. The choline level in acute lesions was significantly higher (P < 0.001 ) than in chronic lesions. Evidence was also found for increased glial activity in multiple sclerosis, with significantly higher (P < 0.001) myo- inositol leve ls in acute lesions compared with control white matter. These in vivo results su pport the hypothesis that altered glutamate metabolism is present in brains of m ultiple sclerosis patients.
基金Supported by Natural Science Foundation of Liaoning Province,No.20170541042
文摘BACKGROUND Papillary cystadenoma is a rare benign epithelial tumor of the salivary gland,which is characterized by papillary structures and oncocytic cells with rich eosinophilic cytoplasm. We found only one case of papillary cystadenoma in nearly 700 cases of salivary gland tumors. Our case was initially mistaken for a tumor of the right temporomandibular joint(TMJ) capsule rather than of parotid gland origin. Preoperative magnetic resonance imaging(MRI) and computed tomography(CT) should be carefully studied, which allows for appropriate preoperative counseling and operative planning.CASE SUMMARY Here, we report an unusual case of a 54-year-old woman with a parotid gland papillary cystadenoma(PGPC) that was misdiagnosed as a tumor of the right TMJ capsule. She was initially admitted to our hospital due to a mass anterior to her right ear inadvertently found 5 d ago. Preoperative CT and MRI revealed a well circumscribed tumor that was attached to the right TMJ capsule. The patient underwent a resection through an incision for TMJ, but evaluation of an intraoperative frozen section revealed a benign tumor of the parotid gland. Then we removed part of the parotid gland above the temporal facial trunk. The facial nerve was preserved. Postoperative histopathological findings revealed that the tumor was PGPC. No additional treatment was performed. There was no recurrence during a 20-mo follow-up period.CONCLUSION The integrity of the interstitial space around the condyle in MRI or CT should be carefully evaluated for parotid gland or TMJ tumors.
基金Supported by NIA Grants for Early Medical and Surgical Subspecialists’ Transition to Aging Research(R03AG045072,Lai)NIA Paul B.Beeson Career Development Award in Aging(K23AG048337,Lai)NIDDK National Research Service Award Hepatology Training Grant(T32DK060414,Rubin)
文摘BACKGROUND Hospital admissions are common among patients with cirrhosis,but patient factors associated with hospitalization have not been well characterized.Given recent data suggesting increased liver transplant waitlist dropout among women,we hypothesized that women on the liver transplant waitlist would have increased rates of hospitalization compared with men.AIM To evaluate the role of gender on risk of hospitalization for patients on the liver transplant waitlist,in order to help explain gender disparities in waitlist outcomes.METHODS Patients listed for liver transplant at a single center in the United States were prospectively enrolled in the Functional Assessment in Liver Transplantation Study.Patients included in this retrospective analysis included those enrolled between March 2012 and December 2014 with at least 12 mo of follow up and without hepatocellular carcinoma.The primary and secondary outcomes were hospitalization and total inpatient days within 12 mo,respectively.Logistic and negative binomial regression associated baseline factors with outcomes.RESULTS Of the 392 patients,41%were female,with median(interquartile range)age 58 years(52-63)and model for end-stage liver disease 18(15-22).Within 12 mo,186(47%)patients were hospitalized≥1 time;48%were readmitted,with a median of 8(4-15)inpatient days.More women than men were hospitalized(54%vs 43%;P=0.03).In univariable analysis,female sex was associated with an increased risk of hospitalization[odds ratios(OR)1.6,95%confidence interval(CI)1.0-2.4;P=0.03],which remained significant on adjusted multivariable analysis(OR 1.6,95%CI:1.1-2.6;P=0.03).Female gender was also associated with an increased number of inpatient days within 12 mo in both univariable and multivariable regression.CONCLUSION Women with cirrhosis on the liver transplant waitlist have more hospitalizations and inpatient days in one year compared with men,suggesting that the experience of cirrhosis differs between men and women,despite similar baseline illness severity.Future studies should explore gender-specific vulnerabilities to help explain waitlist disparities.
文摘Although severe and chronic mental disorders are common among Asian Americans in residential treatment programs, little has been known about the prevalence and predictors of co-occurring substance use in this population. The purpose of this study was to examine predictors of co-occurring substance use among Asian Americans with mental disorders in residential treatment programs. This cross-sectional study included 375 clinical records of Asian Americans from residential treatment programs between 2007 and 2011. Demographic variables, principal psychiatric diagnoses, and data on alcohol, stimulant, and marijuana use were obtained from the clinical records. Separate binary logistic regression analyses were used to examine the demographic and diagnostic contributions to the risk of each type of substance use. Findings of this study indicated that the prevalence of co-occurring substance use was about 53% in Asian Americans with mental disorders. Binary logistic regression analyses revealed that male gender, older age, and depressive disorder predicted more alcohol use, but homelessness and schizophrenia predicted less alcohol use. Male gender, homelessness, and smoking predicted more stimulant use. Male gender and younger age predicted more marijuana use. Based on the findings of this study, awareness about co-occurring substance use problems of ethnic minority psychiatric clients should be increased and appropriate substance use prevention and treatment programs should be developed and provided for high-risk groups.
基金supported by the National Science Foundation(NSF),Grant Number[DGE 1752814].
文摘Extracellular-matrix composition impacts mechanical performance in native and engineered tissues.Previous studies showed collagen typeⅠ-agarose blends increased cell-matrix interactions and extracellular matrix production.However,long-term impacts on protein production and mechanical properties of engineered cartilage are unknown.Our objective was to characterize the effect of collagen type I on the matrix production of chondrocytes embedded in agarose hydrogels.We hypothesized that the addition of collagen would improve longterm mechanical properties and matrix production(e.g.collagen and glycosaminoglycans)through increased bioactivity.Agarose hydrogels(2%w/v)were mixed with varying concentrations of collagen typeⅠ(0,2 and 5 mg/ml).Juvenile bovine chondrocytes were added to the hydrogels to assess matrix production over 4 weeks through biochemical assays,and mechanical properties were assessed through unconfined compression.We observed a dose-dependent effect on cell bioactivity,where 2 mg/ml of collagen improved bioactivity,but 5 mg/ml had a negative impact on bioactivity.This resulted in a higher modulus for scaffolds supplemented with lower collagen concentration as compared to the higher collagen concentration,but not when compared to the control.In conclusion,the addition of collagen to agarose constructs provided a dose-dependent impact on improving glycosaminoglycan production but did not improve collagen production or compressive mechanics.
文摘On April 13,2021,the US Centers for Disease Control and Prevention(CDC)and the US Food and Drug Administration(FDA)recommended a pause in administration of the Ad26.COV2.S(Johnson&Johnson[Janssen])coronavirus disease 2019(COVID-19)vaccine for all persons[1].At that time,approximately 6.8 million doses of vaccine had been administered around the United States.The pause was prompted by 6 cases of cerebral venous sinus thrombosis(CVST)in combination with thrombocytopenia,a condition whose nomenclature is in flux but which we will refer to as thrombosis with thrombocytopenia syndrome(TTS),as used by CDC in describing the condition[2].All patients were women younger than 50 years.Of note,2 of 6 patients also had splanchnic and portal vein thrombosis.
