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1.
Arterioscler Thromb Vasc Biol ; 41(2): 915-930, 2021 02.
Article in English | MEDLINE | ID: mdl-33356390

ABSTRACT

OBJECTIVE: Circulating progenitor cells possess vasculogenesis property and participate in repair of vascular injury. Cx (connexin) 43-a transmembrane protein constituting gap junctions-is involved in vascular pathology. However, the role of Cx43 in smooth muscle progenitor cells (SPCs) remained unclear. Approach and Results: Human SPCs cultured from CD34+ peripheral blood mononuclear cells expressed smooth muscle cell markers, such as smooth muscle MHC (myosin heavy chain), nonmuscle MHC, calponin, and CD140B, and Cx43 was the most abundant Cx isoform. To evaluate the role of Cx43 in SPCs, short interference RNA was used to knock down Cx43 expression. Cellular activities of SPCs were reduced by Cx43 downregulation. In addition, Cx43 downregulation attenuated angiogenic potential of SPCs in hind limb ischemia mice. Protein array and ELISA of the supernatant from SPCs showed that IL (interleukin)-6, IL-8, and HGF (hepatocyte growth factor) were reduced by Cx43 downregulation. Simultaneously, Cx43 downregulation reduced the phosphorylation of NF-κB (nuclear factor kappa-light-chain-enhancer of activated B cells) and Akt (protein kinase B) pathway and reactivation of NF-κB and Akt using betulinic acid, and SC79 could restore the secretion of growth factors and cytokines. Moreover, FAK (focal adhesion kinase)-Src (proto-oncogene tyrosine-protein kinase Src) activation was increased by Cx43 downregulation, and inactivation of Akt-NF-κB could be restored by Src inhibitor (PP2), indicating that Akt-NF-κB inactivated by Cx43 downregulation arose from FAK-Src activation. Finally, the depressed cellular activities and secretion of SPCs after Cx43 downregulation were restored by FAK inhibitor PF-562271 or PP2. CONCLUSIONS: SPCs possess angiogenic potential to repair ischemic tissue mainly through paracrine effects. Gap junction protein Cx43 plays an important role in regulating cellular function and paracrine effects of SPCs through FAK-Src axis.


Subject(s)
Connexin 43/metabolism , Ischemia/surgery , Muscle, Skeletal/blood supply , Myocytes, Smooth Muscle/transplantation , NF-kappa B/metabolism , Neovascularization, Physiologic , Proto-Oncogene Proteins c-akt/metabolism , Animals , Cell Movement , Cell Proliferation , Cells, Cultured , Connexin 43/genetics , Disease Models, Animal , Down-Regulation , Female , Hindlimb , Humans , Inflammation Mediators/metabolism , Ischemia/genetics , Ischemia/metabolism , Ischemia/physiopathology , Mice, Inbred BALB C , Mice, Nude , Mice, Transgenic , Myocytes, Smooth Muscle/metabolism , Phosphorylation , Proto-Oncogene Mas , RNA Interference , Regional Blood Flow , Signal Transduction , Stem Cell Transplantation
2.
Osteoporos Int ; 32(2): 321-332, 2021 Feb.
Article in English | MEDLINE | ID: mdl-32803316

ABSTRACT

This is the first study to report changes in BMD and related risk factors among Chinese patients with HIV after initiation of tenofovir disoproxil fumarate (TDF)-containing antiretroviral therapy. Greater bone mineral density (BMD) loss was observed in patients treated with TDF, compared to those on non-TDF-containing regimens. Our findings provide important knowledge regarding the risk factors in the long-term clinical management of patients with HIV in China. INTRODUCTION: Persons living with HIV (PLWH) are at increased risk for osteoporosis and fracture. Tenofovir disoproxil fumarate (TDF) has been associated with higher rates of bone mineral density (BMD) loss, osteoporosis, and fracture. Few studies have studied the impact among PLWH in Asia. METHODS: We analyzed retrospectively patients from the outpatient HIV clinic of a large tertiary hospital in Beijing, China, from March 2007 to May 2016. Patients who had dual-energy X-ray absorptiometry testing prior to antiretroviral initiation and at 48 and/or 96 weeks after initiation were included in this analysis. RESULTS: A total of 136 patients were included (mean age 36.0 ± 10.6 years) and over 90% participants were male and Han Chinese ethnicity. We observed greater declines in BMD at the spine from baseline to week 48 (-2.94% vs. -0.74%) and at the hip from baseline to week 96 (-4.37% vs. -2.34%) in the TDF group compared with the non-TDF group. With regard to HIV-specific parameters, longer duration since HIV diagnosis and undetectable viral load over time were associated with lower BMD at the hip [relative risk (RR) 0.97, 95% confidence index (CI) (0.95, 0.99) per 1 year increase and RR 0.96, 95%CI (0.94, 0.99), respectively] and femoral neck [RR 0.97, 95%CI (0.95, 0.99) per 1 year increase and RR 0.97, 95%CI (0.95, 0.998), respectively] over 96 weeks. CONCLUSIONS: This is the first study to report changes in BMD among PLWH after initiation of TDF-based antiretroviral therapy in China. Our findings provide important knowledge for the long-term clinical management of PLWH from this region.


Subject(s)
Anti-HIV Agents , HIV Infections , Adult , Anti-HIV Agents/adverse effects , Asia , Bone Density , China/epidemiology , HIV Infections/drug therapy , Humans , Male , Middle Aged , Retrospective Studies
3.
HIV Med ; 2018 May 15.
Article in English | MEDLINE | ID: mdl-29761920

ABSTRACT

OBJECTIVES: Few studies have explored the optimal dosing for efavirenz in individuals from China. We investigated plasma efavirenz concentrations and their association with efficacy and tolerance of efavirenz 600 mg daily in Chinese HIV-infected adults. METHODS: An analysis was performed using plasma samples from 455 patients enrolled in a prospective multicentre trial in China. A total of 1198 plasma samples collected at weeks 4, 24 and 48 following antiretroviral therapy initiation were analysed. The mid-dose interval efavirenz concentrations (C12 ) were determined using high-performance liquid chromatography. RESULTS: The median efavirenz concentration (interquartile range) steadily increased over time from 3.02 (2.28-4.23) to 3.71 (2.91-4.91) mg/L from week 4 to 48 (P < 0.001). The proportion of patients with C12 > 4.0 mg/L also rose from 28.0% to 34.2% and 43.8%, measured at 4, 24 and 48 weeks, respectively (P < 0.001). Five patients had efavirenz concentrations < 1.0 mg/L at week 4, 24 or 48. In the multivariable regression analysis, lower body weight and non-Han ethnicities were associated with higher efavirenz concentrations over time. At each time-point, patients with a body weight < 60 kg had significantly higher efavirenz C12 compared with those with body weight ≥ 60 kg (P < 0.05). CONCLUSIONS: Efavirenz concentrations increased steadily over 48 weeks, and a substantial proportion of participants had efavirenz C12 above the upper limit of the proposed therapeutic window, especially those with low body weight (< 60 kg). Based upon these findings, a dosage reduction of efavirenz to 400 mg daily may warrant consideration in this population, especially for those with lower body weight.

4.
Osteoporos Int ; 29(6): 1263-1275, 2018 Jun.
Article in English | MEDLINE | ID: mdl-29546507

ABSTRACT

This study is the first meta-analysis investigating the pooled incidence rates of fractures among patients with RA. Our results demonstrated that this population is at high risk of overall and fragility fractures. Consideration of vertebral imaging and RA-specific risk factor assessment may aid in fracture prevention for this vulnerable group. INTRODUCTION: This systematic review and meta-analysis aims to estimate the incidence of fractures (overall and fragility) in patients with rheumatoid arthritis (RA). METHODS: MEDLINE, EMBASE, and CENTRAL were searched for cohort studies reporting incidence of fractures among patients with RA. Two reviewers independently assessed all studies for inclusion and extracted data. Pooled analyses of incidence rates and relative risk of fractures were conducted using a random-effects model. Subgroup analyses investigated potential sources of heterogeneity, and predictors of fractures were summarized. RESULTS: Twenty-five studies were included in total. The pooled incidence rates of overall and fragility fractures were 33.00 (95% CI 18.39-59.21) and 15.31 (95% CI 10.43-22.47) per 1000 person-years, respectively. Patients with RA had a higher risk of overall (RR 1.52, 95% CI 1.07-2.14) and fragility (RR 1.61, 95% CI 1.44-1.79) fractures. Subgroup analyses suggested a higher risk of fragility fractures among female patients (31.03 vs. 23.75 per 1000 person-years). The pooled site-specific incidence rates of vertebral, hip, forearm, and proximal humeral fractures were 7.51 (95% CI 3.27-17.23), 4.33 (95% CI 2.26-8.27), 3.40 (95% CI 2.27-5.10), and 1.86 (95% CI 1.36-2.53) per 1000 person-years, respectively. Clinical vertebral fractures were underestimated compared with radiographic screening (4.29 vs. 42.40 per 1000 person-years). Predictors of fractures included both traditional OP risk factors and RA-specific factors. CONCLUSIONS: Patients with RA are at high risk of incident overall and fragility fractures. Consideration of vertebral imaging for patients with additional OP risk factors, including RA-specific risk factors, may help with early OP diagnosis and timely intervention.


Subject(s)
Arthritis, Rheumatoid/complications , Osteoporotic Fractures/etiology , Arthritis, Rheumatoid/epidemiology , Humans , Incidence , Osteoporotic Fractures/epidemiology , Publication Bias , Risk Assessment/methods , Sensitivity and Specificity
5.
J Autoimmun ; 2017 Apr 04.
Article in English | MEDLINE | ID: mdl-28389038

ABSTRACT

Systemic Lupus Erythematosus (SLE) is a heterogeneous autoimmune disease with heightened disease severity in children. The incomplete understanding of the precise cellular and molecular events that drive disease activity pose a significant hurdle to the development of targeted therapeutic agents. Here, we performed single-cell phenotypic and functional characterization of pediatric SLE patients and healthy controls blood via mass cytometry. We identified a distinct CD14hi monocyte cytokine signature, with increased levels of monocyte chemoattractant protein-1 (MCP1), macrophage inflammatory protein-1ß (Mip1ß), and interleukin-1 receptor antagonist (IL-1RA). This signature was shared by every clinically heterogeneous patient, and reproduced in healthy donors' blood upon ex-vivo exposure to plasma from clinically active patients only. This SLE-plasma induced signature was abrogated by JAK1/JAK2 selective inhibition. This study demonstrates the utility of mass cytometry to evaluate immune dysregulation in pediatric autoimmunity, by identification of a multi-parametric immune signature that can be further dissected to delineate the events that drive disease pathogenesis.

6.
Am J Infect Control ; 45(3): 240-244, 2017 Mar 01.
Article in English | MEDLINE | ID: mdl-27838163

ABSTRACT

BACKGROUND: Evaluation and feedback is a core hand hygiene (HH) improvement strategy. The covert observation method avoids observation bias inherent to the overt method. The aim of the study was to observe HH compliance by a novel covert method in a real-world setting. METHODS: We conducted a 2-year, nationwide, prospective, observational study in teaching hospitals across Taiwan. Medical students and students who may have contact with patients in their careers were recruited as participants. A novel, shorthand notation method for covert observation was used. Observation results were reported through a study website. RESULTS: There were a total of 25,379 HH opportunities covertly observed by 93 observers. Overall HH compliance was 32.0%. Health care workers had the highest HH compliance for indication 4 (42.6%), and the lowest for indication 5 (21.7%). Overall handrubbing percentage was high, reaching 83.6%. The HH compliance increased significantly with an increase in the number of indications within 1 HH opportunity (P < .001). CONCLUSIONS: The overall HH compliance by the covert observation method was low. An innovative shorthand notation method facilitated covert observation, and website reporting was demonstrated to be feasible for large-scale observation.


Subject(s)
Guideline Adherence/statistics & numerical data , Hand Hygiene/methods , Health Facilities , Observation/methods , Students, Medical , Humans , Prospective Studies , Taiwan
8.
Osteoporos Int ; 26(3): 1035-44, 2015 Mar.
Article in English | MEDLINE | ID: mdl-25224293

ABSTRACT

UNLABELLED: We sought to evaluate the effects of antiretroviral therapy on skeletal metabolism in Chinese individuals with human immunodeficiency virus. Patients switched to tenofovir/lamivudine + lopinavir/ritonavir after treatment failure had an increase in bone resorption marker levels by nearly 60%, which is greater than the magnitude previously described in non-Chinese populations. INTRODUCTION: Few studies have evaluated the effects of antiretroviral therapy on skeletal metabolism in Asian populations infected with human immunodeficiency virus (HIV). METHODS: We performed a secondary analysis of bone turnover markers (BTM) at baseline and 2 years in stored plasma samples collected from 2/2009 to 1/2013 as part of a multi-center trial. Two groups were compared: (1) treatment-naïve patients initiated on zidovudine (AZT)/lamivudine (3TC) plus nevirapine (NVP) and (2) patients who failed first-line therapy and were switched to tenofovir (TDF)/3TC plus lopinavir/ritonavir (LPVr). Tests included the bone resorption marker, C-terminal cross-linking telopeptide of type-1 collagen (CTX), and the bone formation marker procollagen type 1 N-terminal propeptide (P1NP). RESULTS: In the TDF/3TC + LPVr group, samples were available from 59 patients at baseline and 56 patients at 2 years. Of these, 36 patients had samples available from both time points. In the AZT/3TC + NVP group, plasma samples were analyzed from 82 participants at baseline and of those, 61 had samples at 2 years. Median change over 2 years was greater in the TDF/3TC + LPVr group for both CTX (+0.24 ng/mL, interquartile ranges (IQR) 0.10-0.43 vs. +0.09 ng/mL, IQR -0.03 to 0.18, p = 0.001) and P1NP (+25.5 ng/mL, IQR 2.4-51.3 vs. +7.11 ng/mL, IQR -4.3 to 21.6, p = 0.012). Differences remained after adjusting for potential confounders in the multivariable analysis. CONCLUSIONS: Switching to TDF/3TC + LPVr after treatment failure resulted in greater increases in BTMs than initiation with AZT/3TC + NVP in Chinese patients with HIV. Following this change, bone resorption marker levels increased by nearly 60 %, which is greater than the 25-35% increase from baseline described previously in non-Chinese populations. Further studies are warranted to elucidate these findings.


Subject(s)
Anti-HIV Agents/adverse effects , Bone Resorption/chemically induced , HIV Infections/drug therapy , HIV-1 , Lopinavir/adverse effects , Ritonavir/adverse effects , Tenofovir/adverse effects , Adolescent , Adult , Aged , Anti-HIV Agents/therapeutic use , Biomarkers/blood , Bone Remodeling/drug effects , Bone Resorption/blood , Collagen Type I/blood , Drug Combinations , Drug Substitution , Drug Therapy, Combination , Female , HIV Infections/blood , Humans , Lopinavir/therapeutic use , Male , Middle Aged , Peptides/blood , Ritonavir/therapeutic use , Tenofovir/therapeutic use , Young Adult
9.
Clin Exp Rheumatol ; 32(6 Suppl 86): S-115-21, 2014.
Article in English | MEDLINE | ID: mdl-25372797

ABSTRACT

OBJECTIVES: Pulmonary arterial hypertension (PAH) is associated with significant morbidity and mortality, especially in systemic sclerosis (SSc). Since there was no published study regarding PAH in the Chinese SSc population, we aimed to describe a cohort to provide some data for early diagnosis. METHODS: We evaluated 236 systemic sclerosis patients prospectively registered in the EUSTAR (European League Against Rheumatism Scleroderma Trial and Research Group) database from the Peking Union Medical College Hospital from 2009 to 2012. Among them, 33 individuals received right heart catheterisations (RHC) while the remaining patients were grouped by echocardiographic data. These patients were classified into two groups, PAH and non-PAH group. Their clinical and laboratory features were statistically analysed to identify possible risk factors for PAH in Chinese SSc population. RESULTS: The possible prevalence of PAH in SSc patients was approximately 11% in our study. Digital ulcers (52.0% vs. 31.2%), telangiectasias (64.0% vs. 37.6%) and gastroesophageal reflux disease (GERD) (60.0% vs. 36.2%) were more common in SSc patients with PAH. Some laboratory results were also proved to be significantly correlated with it. Logistic regression analysis showed that telangiectasias (OR=2.888, 95% CI=1.176-7.093), presence of GERD (OR=2.592, 95% CI=1.067-6.296), anti-RNP positivity (OR=24.384, 95% CI=1.978-36.651), IgA level elevation (OR=8.745, 95% CI 4.838-122.896) and FVC/TLCO ratio (OR=97.067, 95% CI 12.475-755.271) were associated with an increased odds for PAH in SSc patients. CONCLUSIONS: This study described possible predictors of PAH in Chinese SSc population, which have been supported by similar studies in other ethnic groups.


Subject(s)
Gastroesophageal Reflux/etiology , Hand Dermatoses/etiology , Hypertension, Pulmonary/etiology , Scleroderma, Systemic/complications , Skin Ulcer/etiology , Adult , Autoantibodies/immunology , China , Databases, Factual , Female , Humans , Hypertension, Pulmonary/immunology , Hypertension, Pulmonary/physiopathology , Immunoglobulin A/immunology , Logistic Models , Lung/physiopathology , Male , Middle Aged , Ribonucleoproteins/immunology , Scleroderma, Systemic/immunology , Scleroderma, Systemic/physiopathology , Telangiectasis/etiology , Vital Capacity
10.
Early Hum Dev ; 88 Suppl 2: S6-S10, 2012 May.
Article in English | MEDLINE | ID: mdl-22633516

ABSTRACT

Candida infections are a major cause of morbidity and mortality in neonatal intensive care units. Mortality following Candida bloodstream infections is as high as 40%, and neurodevelopmental impairment is common among survivors. Because invasive fungal infections are common and extremely difficult to diagnose, empirical treatment with antifungal therapy should be considered in high-risk, low-birth-weight infants who fail to quickly respond to empirical antibacterial treatment. Risk factors to consider when deciding to administer empirical antifungal therapy include: prior exposure to third-generation cephalosporins, extreme prematurity, and presence of central venous catheters.


Subject(s)
Antifungal Agents/therapeutic use , Candidiasis, Invasive/drug therapy , Cephalosporins/therapeutic use , Infant, Premature, Diseases/drug therapy , Central Nervous System Infections/drug therapy , Central Venous Catheters , Fungemia/drug therapy , Humans , Infant , Infant, Newborn , Infant, Premature , Risk Factors , Treatment Outcome
12.
Oncogene ; 26(18): 2585-94, 2007 Apr 19.
Article in English | MEDLINE | ID: mdl-17043637

ABSTRACT

Epidermal growth factor (EGF) expresses mitogenic activity by a mechanism that requires the EGF receptor (EGFR). We report that murine embryonic fibroblasts (MEFs) proliferate in response to EGF only when these cells express the urokinase receptor (uPAR). EGFR expression was equivalent in uPAR-/- and uPAR+/+ MEFs. In response to EGF, these cells demonstrated equivalent overall EGFR tyrosine phosphorylation and ERK/MAP kinase activation; however, phosphorylation of Tyr-845 in the EGFR, which has been implicated in cell growth, was substantially decreased in uPAR-/- MEFs. STAT5b activation also was decreased. As Tyr-845 is a c-Src target, we overexpressed c-Src in uPAR-/- MEFs and rescued EGF mitogenic activity. Rescue also was achieved by expressing murine but not human uPAR, suggesting a role for autocrine uPAR cell-signaling. In MDA-MB 231 breast cancer cells, EGF mitogenic activity was blocked by uPAR gene silencing, with antibodies that block uPA-binding to uPAR, and with a synthetic peptide that disrupts uPAR-dependent cell signaling. Again, c-Src overexpression rescued the mitogenic activity of EGF. We conclude that uPAR-dependent cell-signaling may prime cells to proliferate in response to EGF by promoting Tyr-845 phosphorylation and STAT5b activation. The importance of this pathway depends on the c-Src level in the cell.


Subject(s)
Breast Neoplasms/pathology , Cell Proliferation/drug effects , Epidermal Growth Factor/pharmacology , Receptors, Cell Surface/physiology , Animals , Autocrine Communication , Breast Neoplasms/metabolism , Cells, Cultured , Embryo, Mammalian/cytology , Embryo, Mammalian/drug effects , Embryo, Mammalian/metabolism , ErbB Receptors/metabolism , Fibroblasts/cytology , Fibroblasts/drug effects , Fibroblasts/metabolism , Humans , Mice , Mice, Knockout , Mitogen-Activated Protein Kinases/metabolism , Phosphorylation , Plasminogen/metabolism , Protein Binding , Proto-Oncogene Proteins pp60(c-src)/metabolism , RNA, Small Interfering/pharmacology , Receptors, Urokinase Plasminogen Activator , STAT5 Transcription Factor/metabolism , Tyrosine/metabolism , Urokinase-Type Plasminogen Activator/metabolism
13.
Appl Radiat Isot ; 64(10-11): 1313-8, 2006.
Article in English | MEDLINE | ID: mdl-16564692

ABSTRACT

Efficiency calibrations of multiple high-purity germanium (HPGe) detectors are being maintained at the National Institute of Standards and Technology (NIST). Four generally available software packages for HPGe detector gamma-ray spectrum analysis, including the one currently used at NIST, were tested on spectra collected from two HPGe detectors at different source-to-detector distances and using point sources and ampoules as calibration geometries. The resulting efficiency curves were inter-compared.


Subject(s)
Algorithms , Germanium/radiation effects , Radiation Monitoring/instrumentation , Radiation Monitoring/methods , Software Validation , Software , Calibration/standards , Equipment Failure Analysis/methods , Internationality , Radiation Dosage , Reproducibility of Results , Semiconductors , Sensitivity and Specificity , Transducers
14.
Spinal Cord ; 44(11): 692-4, 2006 Nov.
Article in English | MEDLINE | ID: mdl-16344849

ABSTRACT

STUDY DESIGN: Retrospective case study. OBJECTIVES: Report a rare case of cervical myelopathy induced by calcium pyrophosphate dehydrate (CPPD) deposition in multiple cervical levels. SETTING: An area teaching hospital in Taiwan. METHOD: A patient with cervical myelopathy was evaluated by computerized tomography (CT) scan and magnetic resonance (MR) image. CPPD deposition known as pseudogout was diagnosed and approved by a polarized microscope. RESULT: A prominent hypertrophy of ligmentum flavum and a retro-odontoid bulging mass induced cord compression were found in CT scan and MR image. CPPD deposition was confirmed by the histological examinations in the ligamentum flavum at the spinal levels of C3-C6. After decompression surgery of spine and comprehensive rehabilitation, the patient's neurological symptoms subsided and her neurological functions improved leading to a good prognosis. CONCLUSION: CPPD deposition in cervical spine occurring at multiple levels is rare. Image studies with CT scan and MR are complementary in the diagnosis of CPPD-induced myelopathy. Surgical decompression is always required and expected to have a good outcome.


Subject(s)
Chondrocalcinosis/complications , Ligamentum Flavum/pathology , Odontoid Process/pathology , Spinal Cord Diseases/etiology , Spinal Diseases/etiology , Aged , Female , Humans , Ligamentum Flavum/diagnostic imaging , Magnetic Resonance Imaging/methods , Retrospective Studies , Spinal Cord Diseases/pathology , Spinal Diseases/pathology , Spinal Diseases/radiotherapy , Tomography, X-Ray Computed/methods
15.
AIDS Res Hum Retroviruses ; 17(1): 1-33, 2001 Jan 01.
Article in English | MEDLINE | ID: mdl-11177380

ABSTRACT

As the number of women infected with HIV in the United States continues to increase, the medical community is faced with the challenge of providing adequate and appropriate care to them. This paper reviews key questions concerning the state of knowledge on the epidemiology, biology, and clinical care of women living with HIV and AIDS in the United States. Because heterosexual transmission accounts for a growing number of cases among women, biological factors and cofactors that may enhance women's susceptibility to HIV infection are also reviewed. HIV-related gynecological issues are presented separately to evaluate whether gynecological complications are distinct in HIV-uninfected and HIV-infected women. Questions of whether there are sex-specific differences in the efficacy and adverse effects of new antiviral agents are discussed. In addition, significant gaps are highlighted that still exist in our understanding of both the effects of HIV and HIV-related drugs upon pregnancy. Finally, the psychiatric stresses and complications that affect women living with HIV and AIDS are also discussed. In each section of this review, gaps in our knowledge of these issues are identified. To properly address these disparities in knowledge, not only do efforts to gather sex-specific biomedical data need to be more exacting, but there is a distinct need to conduct more sex-specific research concerning HIV.


Subject(s)
Acquired Immunodeficiency Syndrome , HIV Infections , Primary Health Care , Acquired Immunodeficiency Syndrome/drug therapy , Acquired Immunodeficiency Syndrome/epidemiology , Acquired Immunodeficiency Syndrome/prevention & control , Acquired Immunodeficiency Syndrome/psychology , Animals , Anti-HIV Agents/therapeutic use , Female , HIV Infections/drug therapy , HIV Infections/epidemiology , HIV Infections/prevention & control , HIV Infections/psychology , Humans , Infectious Disease Transmission, Vertical/prevention & control , Pregnancy , Pregnancy Complications, Infectious/prevention & control , Psychology , United States/epidemiology
16.
Lung Cancer ; 29(2): 151-7, 2000 Aug.
Article in English | MEDLINE | ID: mdl-10963846

ABSTRACT

The interaction of epidermal growth factor receptor (EGFR) and its ligand transforming growth factor-alpha (TGF-alpha) leads to an autocrine activation of the ras signaling pathway and putatively its oncogenic activity. It is thus hypothesized that the co-overexpression of EGFR-TGFalpha will be redundant hence rare in tumors with oncogenic ras mutations. To test this hypothesis, we studied by immunohistochemistry the expression of EGFR and TGF-alpha in primary non small cell lung cancers. Such putative EGFR autocrine loop activation was found in 73% of squamous cell carcinomas that rarely develop ras mutations. In contrast, EGFR-TGFalpha co-expression occurred with equal frequency in adenocarcinomas irrespective of their ras genotype. The results indicate that EGFR autocrine loop activity in adenocarcinoma may have alternative signaling activities aside from the activation of ras-MAP kinase pathway.


Subject(s)
Adenocarcinoma/metabolism , Carcinoma, Non-Small-Cell Lung/metabolism , ErbB Receptors/metabolism , Genes, ras/genetics , Lung Neoplasms/metabolism , Transforming Growth Factor alpha/metabolism , Adenocarcinoma/genetics , Carcinoma, Large Cell/genetics , Carcinoma, Large Cell/metabolism , Carcinoma, Non-Small-Cell Lung/genetics , Carcinoma, Squamous Cell/genetics , Carcinoma, Squamous Cell/metabolism , ErbB Receptors/genetics , Gene Expression Regulation, Neoplastic , Humans , Immunohistochemistry , Lung Neoplasms/genetics , Mutation , Signal Transduction , Transforming Growth Factor alpha/genetics
17.
N Engl J Med ; 342(2): 69-77, 2000 Jan 13.
Article in English | MEDLINE | ID: mdl-10631274

ABSTRACT

BACKGROUND: Colorectal cancer can arise through two distinct mutational pathways: microsatellite instability or chromosomal instability. We tested the hypothesis that colorectal cancers arising from the microsatellite-instability pathway have distinctive clinical attributes that affect clinical outcome. METHODS: We tested specimens of colorectal cancer from a population-based series of 607 patients (50 years of age or younger at diagnosis) for microsatellite instability. We compared the clinical features and survival of patients who had colorectal cancer characterized by high-frequency microsatellite instability with these characteristics in patients who had colorectal cancers with microsatellite stability. RESULT: We found high-frequency microsatellite instability in 17 percent of the colorectal cancers in 607 patients, and in a multivariate analysis, microsatellite instability was associated with a significant survival advantage independently of all standard prognostic factors, including tumor stage (hazard ratio, 0.42; 95 percent confidence interval, 0.27 to 0.67; P< 0.001). Furthermore, regardless of the depth of tumor invasion, colorectal cancers with high-frequency microsatellite instability had a decreased likelihood of metastasizing to regional lymph nodes (odds ratio, 0.33; 95 percent confidence interval, 0.21 to 0.53; P< 0.001) or distant organs (odds ratio, 0.49; 95 percent confidence interval, 0.27 to 0.89; P=0.02). CONCLUSION: High-frequency microsatellite instability in colorectal cancer is independently predictive of a relatively favorable outcome and, in addition, reduces the likelihood of metastases.


Subject(s)
Colorectal Neoplasms/genetics , Microsatellite Repeats/genetics , Adult , Colorectal Neoplasms/mortality , Colorectal Neoplasms/pathology , Colorectal Neoplasms/therapy , Female , Humans , Male , Middle Aged , Multivariate Analysis , Mutation , Prognosis , Survival Analysis
18.
Am J Surg Pathol ; 23(10): 1248-55, 1999 Oct.
Article in English | MEDLINE | ID: mdl-10524526

ABSTRACT

Inactivation of deoxyribonucleic acid (DNA) mismatch repair genes, most commonly human mutL homologue 1 (hMLH1) or human mutS homologue 2 (hMSH2), is a recently described alternate pathway in cancer development and progression. The resulting genetic instability is characterized by widespread somatic mutations in tumor DNA, and is termed high-frequency microsatellite instability (MSI-H). Although described in a variety of tumors, mismatch repair deficiency has been studied predominantly in colorectal carcinoma. Most MSI-H colorectal carcinomas are sporadic, but some occur in patients with hereditary nonpolyposis colorectal cancer (HNPCC), and are associated with germline mutations in mismatch repair genes. Until now, the identification of MSI-H cancers has required molecular testing. To evaluate the role of immunohistochemistry as a new screening tool for mismatch repair-deficient neoplasms, the authors studied the expression of hMLH1 and hMSH2, using commercially available monoclonal antibodies, in 72 formalin-fixed, paraffin-embedded tumors that had been tested previously for microsatellite instability. They compared immunohistochemical patterns of 38 MSI-H neoplasms, including 16 cases from HNPCC patients with known germline mutations in hMLH1 or hMSH2, with 34 neoplasms that did not show microsatellite instability. Thirty-seven of 38 MSI-H neoplasms were predicted to have a mismatch repair gene defect, as demonstrated by the absence of hMLH1 and/or hMSH2 expression. This included correspondence with all 16 cases with germline mutations. All 34 microsatellite-stable cancers had intact staining with both antibodies. These findings clearly demonstrate that immunohistochemistry can discriminate accurately between MSI-H and microsatellite-stable tumors, providing a practical new technique with important clinical and research applications.


Subject(s)
Adenocarcinoma/genetics , Base Pair Mismatch/genetics , Colorectal Neoplasms/genetics , DNA Repair , DNA-Binding Proteins , Neoplasm Proteins/analysis , Proto-Oncogene Proteins/analysis , Adaptor Proteins, Signal Transducing , Adenocarcinoma/chemistry , Adenocarcinoma/pathology , Adult , Carrier Proteins , Colorectal Neoplasms/chemistry , Colorectal Neoplasms/pathology , DNA, Neoplasm/analysis , Genes, DCC/genetics , Genetic Predisposition to Disease/genetics , Humans , Immunoenzyme Techniques , Microsatellite Repeats/genetics , MutL Protein Homolog 1 , MutS Homolog 2 Protein , Nuclear Proteins , Polymerase Chain Reaction
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