The PMI local site demonstration project: lessons in technical assistance.
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Americas↗
Biomedical subjects
J Rosenbaum
Publications and source records attributed to J Rosenbaum.
Hepatocarcinoma cells stimulate hepatocyte growth factor secretion in human liver myofibroblasts.
Hepatocellular carcinoma (HCC), the main type of primary liver cancer, is characterized by a high rate of intra-hepatic invasion. The stroma of HCC is infiltrated by myofibroblasts. We have previously shown that hepatocyte growth factor (HGF) secreted by human liver myofibroblasts greatly increased the in vitro invasiveness of 3 human HCC cell lines. In this study we show that the conditioned medium (CM) from the same HCC cell lines dose-dependently stimulates HGF secretion by myofibroblasts. This effect was post-transcriptional as no increase in HGF mRNA was observed. We show that the effect of CM is not due to IL-1, IL-6, IGF-1, bFGF or PDGF, previously shown to stimulate HGF synthesis in other models. Our data demonstrate that HCC cells increase HGF secretion by liver myofibroblasts in a paracrine way that could act to enhance invasion.
Carcinoma, Hepatocellular↗
Osteonectin/SPARC is overexpressed in human hepatocellular carcinoma.
Osteonectin (ON)/SPARC is a glycoprotein involved in extracellular matrix remodelling. ON expression by myofibroblasts has been reported in fibrotic human liver. As ON also plays a role in cell adhesion, differentiation, and proliferation, this study was designed to document its expression in human hepatocellular carcinoma (HCC). Tissues from 26 HCCs of various histological grades and architecture and from surrounding non-tumour liver (23 cirrhotic or fibrotic, three non-fibrotic) were tested by in situ hybridization and immunohistochemistry. Immunohistochemical detection of alpha-smooth muscle actin (alpha-SMA) was performed on serial sections or in combination with hybridization. Large amounts of ON mRNA and protein were detected in the tumour capsule, in the fibrous bands, and along capillaries within HCCs. The signal was located in cells suggestive of myofibroblasts, as confirmed by positive staining for alpha-SMA. In HCC, ON protein was always detectable, with strong staining in high-grade tumours, whereas it was mostly undetectable in non-tumour tissues. A clear difference was also shown for ON transcripts, except in a few cases with chronic active hepatitis, where ON transcripts were also expressed at a high level. Overexpression of ON transcripts in HCC vs. non-tumour liver was confirmed by RNA blot in 20/22 patients tested. In conclusion, ON is strongly expressed by the stromal myofibroblasts of human HCC, especially of high grade. This expression could play a role in tumour progression.
Actins↗
Impact of V beta 8+/+ T cells on the development of increased airway reactivity and IgE production in SJL mice.
SJL mice have been extensively characterized as "low-responder" animals in terms of IgE-dependent immediate-type hypersensitivity responses. Since these mice are genetically deficient in certain TCR Vbeta gene segments, we asked whether this might be the reason for the "low-responder" status. Specifically in H-2d mice the TCR-Vbeta8.2 gene element has been shown to play an important role in Th2 immune responses to ovalbumin (OVA). Utilizing a TCR Vbeta8. 2-transgenic SJL (SJL Vbeta8+/+) mouse, we examined whether the H-2s -bearing "low-responder" mouse could be converted into a "high-responder" animal. Remarkably, non-sensitized SJL Vbeta8+/+ mice demonstrated strongly elevated levels of total IgE antibody. Mitogen-stimulated T cells from these mice released high amounts of IL-4 as compared to SJL wild-type (wt) mice. In addition, sensitization to OVA via the airways resulted in the development of increased airway responsiveness in SJL Vbeta8+/+ mice, but not in SJL wt animals. The results indicate that the capacity to produce IgE and IL-4 and to develop increased airway responsiveness can be restored in SJL wt mice by introducing the Vbeta8.2 gene segment into the TCR repertoire.
Allergens↗
Hepatocyte growth factor secreted by human liver myofibroblasts increases invasiveness of hepatocellular carcinoma cells.
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Blotting, Northern↗
Fluoxetine efficacy in menopausal women with and without estrogen replacement.
UNLABELLED: A gradual decline in estrogen levels after the age of 40 may contribute to a higher rate of depression in women over 45 years of age. Estrogen replacement therapy (ERT) has been shown to produce cognitive and mood-enhancing effects in women and may facilitate antidepressant activity. METHODS: We examined the efficacy rates in women on ERT > or = 45 years (n = 40) compared to women > or = 45 years not on ERT (n = 132) and to women < 45 years (n = 396) and to men (n = 262) with major depression during fluoxetine 20 mg daily up to 8 weeks. Remitters with a HAM-D17 score < or = 7 from week 9 to 12 were then treated up to 1-year in a placebo-controlled, relapse-prevention trial. RESULTS: Efficacy rates were similar in women > or = 45 years on ERT when compared to women > or = 45 years taking fluoxetine alone, and when compared to women < 45 years and men taking fluoxetine. A Kaplan-Meier survival analysis in fluoxetine responders treated up to 26 weeks showed a somewhat greater relapse rate in women > or = 45 years taking ERT compared to other treatment groups (P < 0.06). LIMITATIONS: This study was retrospective nature and ERT was given in an uncontrolled fashion: 63% of women received estrogen alone while 37% also took intermittent progesterone. Other variables include the absence of hormonal documentation of menopausal status, no direct assessment of ERT compliance and the use of fixed-dose fluoxetine 20 mg daily. CONCLUSION: In contrast to prior reports suggesting that ERT may facilitate antidepressant activity, we observed similar efficacy in depressed women > or = 45 years taking fluoxetine plus ERT compared to those taking fluoxetine alone.
Antidepressive Agents, Second-Generation↗
Myofibroblasts are responsible for collagen synthesis in the stroma of human hepatocellular carcinoma: an in vivo and in vitro study.
BACKGROUND/AIMS: Marked changes in extracellular matrix occur in the stroma of hepatocellular carcinoma, as compared to normal or cirrhotic liver. The cell types responsible for extracellular matrix synthesis within hepatocellular carcinoma have not been clearly identified. METHODS: In vivo collagen synthesis was studied by in situ hybridization and immunohistochemistry for types I, IV, V and VI collagen, together with immunolabeling of alpha-smooth muscle actin, a myofibroblast marker, and CD34, an endothelial cell marker. In vitro, extracellular matrix deposition by cultured myofibroblasts was studied by reticulin staining, immunocytochemistry and RNase protection. RESULTS: All collagens studied were expressed in the stroma of the tumor, with a higher level of type VI and IV collagens than of type I and V. The majority of the cells expressing collagen transcripts in human hepatocellular carcinoma stroma were alpha-actin positive and CD 34 negative. In vitro experiments demonstrated that the hepatocellular carcinoma cell lines HepG2, HuH7 and Hep3B markedly increased extracellular matrix deposition by human liver myofibroblasts. This increase was mediated by a soluble mediator present in tumor cell conditioned medium. It was not explained by an increase in mRNA levels of extracellular matrix components, nor by a decrease in the secretion of matrix-degrading proteinases by myofibroblasts. CONCLUSIONS: Myofibroblasts are the main source of collagens in the stroma of hepatocellular carcinoma. Our data also indicate that tumoral hepatocytes increase extracellular matrix deposition by cultured myofibroblasts, probably by post-transcriptional mechanisms. The generation of hepatocellular carcinoma stroma by myofibroblasts could thus be under control of tumoral cells.
Carcinoma, Hepatocellular↗
Direct evidence that hepatocyte growth factor-induced invasion of hepatocellular carcinoma cells is mediated by urokinase.
BACKGROUND/AIMS: We have shown that hepatocyte growth factor secreted by human hepatic myofibroblasts increased the in vitro invasion of the hepatocarcinoma cell line HepG2 through Matrigel. Our aim in this study was to evaluate the role of urokinase in this process. METHODS: Expression of urokinase in HepG2 cells was measured by Northern blot and zymography, and plasminogen activation was shown by a chromogenic substrate assay. Cell invasion was assayed on Matrigel-coated filters. Urokinase and urokinase receptor transcripts in hepatocarcinoma were detected by reverse transcription-polymerase chain reaction. Activated hepatocyte growth factor was detected by Western blot with a hepatocyte growth factor-beta chain-specific antibody. RESULTS: HepG2 cells expressed urokinase mRNA and secreted active urokinase. Urokinase expression was enhanced by hepatocyte growth factor at the protein and mRNA level. Notably, cell-surface-associated urokinase was increased 22-fold by hepatocyte growth factor. Hepatocyte growth factor also increased urokinase receptor mRNA expression. B428, a urokinase inhibitor, decreased by up to 70% HepG2 invasion induced by myofibroblasts and by 90% that induced by recombinant hepatocyte growth factor. This was not due to a decrease in the generation of activated hepatocyte growth factor by myofibroblasts. Finally, all 17 hepatocarcinoma samples tested expressed urokinase and urokinase receptor transcripts. CONCLUSION: Hepatocyte growth factor-dependent, myofibroblasts-induced invasion of HepG2 cells is secondary to the induction of urokinase expression on tumor cells.
Carcinoma, Hepatocellular↗
Expression of collagens type I and IV, osteonectin and transforming growth factor beta-1 (TGFbeta1) in biliary atresia and paucity of intrahepatic bile ducts during infancy.
BACKGROUND/AIMS: Biliary atresia and paucity of intrahepatic bile ducts are the main causes of neonatal cholestasis leading to hepatic fibrosis. Fibrotic evolution is slow in paucity of bile ducts as compared to the rapid progression to biliary cirrhosis in biliary atresia when cholestasis persists despite hepatoportoenterostomy. Our aim was to compare the expression of collagens type I and IV, alpha-smooth muscle actin, osteonectin and transforming growth factor beta1 in biliary atresia and paucity of bile ducts. METHODS: Liver biopsies were obtained in 12 children with biliary atresia and in five with paucity of bile ducts. Collagens type I and IV, alpha-smooth muscle actin were detected with immunostaining. Collagens type I and IV, osteonectin and transforming growth factor beta1 mRNAs were detected by in situ hybridization. RESULTS: Expression of mRNA and proteins was roughly parallel. In ductular proliferation areas of biliary atresia: (1) the expression of collagens type I and IV and osteonectin was increased, and was localized to periductular myofibroblasts; (2) transforming growth factor beta1 was expressed around biliary ductules, probably in inflammatory cells, and also in biliary cells. Osteonectin expression was also increased in the lobules. In paucity of bile ducts, there was no overexpression of collagens type I and IV and transforming growth factor beta1, except in the only child with marked fibrosis. However, osteonectin expression was enhanced at the periphery of the lobules, even when fibrosis was mild or absent. CONCLUSIONS: These findings suggest that in biliary atresia ductular proliferation areas are the site of a marked production of extracellular matrix proteins in periductular myofibroblasts, probably secondary to transforming growth factor beta1 production by inflammatory cells and by biliary cells. The weak expression of transforming growth factor beta1 could explain the slow progression of fibrosis in paucity of bile ducts.
Actins↗
Is premenstrual dysphoric disorder a distinct clinical entity?
Does the evidence now available support the concept of premenstrual dysphoric disorder (PMDD) as a distinct clinical disorder such that the relative safety and efficacy of potential treatment can be evaluated? In a roundtable discussion of this question, a wealth of information was reviewed by a panel of experts. The key characteristics of PMDD, with clear onset and offset of symptoms closely linked to the menstrual cycle and the prominence of symptoms of anger, irritability, and internal tension, were contrasted with those of known mood and anxiety disorders. PMDD displays a distinct clinical picture that, in the absence of treatment, is remarkably stable from cycle to cycle and over time. Effective treatment of PMDD can be accomplished with serotinergic agents. At least 60% of patients respond to selective serotonin reuptake inhibitors (SSRIs). In comparison with other disorders, PMDD symptoms respond to low doses of SSRIs and to intermittent dosing. Normal functioning of the hypothalamic-pituitary-adrenal (HPA) axis, biologic characteristics generally related to the serotonin system, and a genetic component unrelated to major depression are further features of PMDD that separate it from other affective (mood) disorders. Based on this evidence, the consensus of the group was that PMDD is a distinct clinical entity. Potential treatments for this disorder can now be evaluated on this basis to meet the clear need for effective therapy.
Comorbidity↗
Activation of cultured rat hepatic stellate cells by tumoral hepatocytes.
Hepatocellular carcinoma (HCC) is the main type of primary liver cancer, and it develops from hepatocytes. The stroma of HCC is infiltrated by myofibroblasts. In other settings, such as liver fibrosis, myofibroblasts are derived mainly from the activation of hepatic stellate cells (HSC). In this study, we investigated whether tumoral hepatocytes were able to activate HSC. HSC were isolated from normal rats and were plated in dishes coated with Matrigel, to prevent their spontaneous activation. HSC were exposed to conditioned medium (CM) from the rat HCC lines Fao and H5. Tumor cell CM elicited major morphologic changes, such as spreading and generation of cytoplasmic processes. Fao and H5 CM increased HSC proliferation to 1.60 and 1.76 times control values, respectively. The expression of alpha-smooth muscle actin was low or undetectable in control cells and was markedly increased by both tumor cell CM but not by normal rat hepatocyte CM. Desmin expression was also enhanced. Gelatinase A secretion was significantly increased 1.20-fold by Fao CM and 1.55-fold by H5 CM. Expression of beta-type platelet-derived growth factor receptor mRNA was increased 5.8-fold by H5 CM but was decreased to 13% of control levels by Fao CM. HSC activation by tumor cell CM was not prevented by urokinase or matrix metalloproteinase inhibitors, suggesting that Matrigel degradation was not central to the activation process. Finally, a blocking antibody to transforming growth factor-beta1 did not impede Fao CM-induced activation but significantly blocked the increase in matrix metalloproteinase-2 expression induced by H5 CM. Our results show that tumoral rat hepatocyte CM is able to induce the activation of rat HSC in culture. The lack of induction of beta-type platelet-derived growth factor receptor mRNA by Fao CM indicates that, in some cases, tumor-induced activation differs from classic fibrosis-type activation. Our data thus suggest that HSC recruitment and activation in HCC could be under the control of tumor cells.
Animals↗
Database protection and access to information.
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Copyright↗
Use of pattern analysis to predict differential relapse of remitted patients with major depression during 1 year of treatment with fluoxetine or placebo.
BACKGROUND: Delayed and persistent ("true drug") improvement characterizes the response to antidepressant medication. Early or nonpersistent ("placebo") benefit is typical of a placebo response. The prediction was that patients with a true drug response would sustain their benefit best if they continued to receive the drug and that patients with a placebo response would have an equivalent prognosis whether they continued to receive the drug or were switched to placebo. METHODS: Patients with major depression who met the study's response criteria (a modified Hamilton Depression Rating Scale score < or =7 and failure to meet major depression criteria after each of the last 3 weeks following 12 to 14 weeks of treatment with fluoxetine hydrochloride, 20 mg/d) were enrolled in a 50-week randomized placebo substitution trial during which the return of depressive symptoms defined relapse. The timing and persistency of response during initial treatment defined true drug or placebo response patterns. RESULTS: Patients with a true drug response pattern relapsed significantly more frequently if they were switched to placebo than if they continued to receive fluoxetine (P<.001 for weeks 12-26, P<.005 for weeks 26-50, and P<.41 for weeks 50-62). Patients with a placebo response pattern had an equivalent outcome whether maintained on fluoxetine therapy or placebo (P< .20 for weeks 12-26, test invalid for weeks 26-50, and P<.67 for weeks 50-62). Patients with a placebo response pattern relapsed more often when they continued to receive fluoxetine than patients with a true drug response pattern (P<.01 for weeks 12-26, P<.10 for weeks 26-50, and P<.36 for weeks 50-62). CONCLUSIONS: These findings confirm that pattern analysis validly differentiates true drug from nonspecific initial responses and extend its use to the continuation and maintenance phases of treatment for depression. Investigations into the mechanisms of antidepressant activity might best be limited to those that can account for delayed efficacy. Fluoxetine's efficacy during the continuation and maintenance phases of treatment may be limited to patients with a true drug pattern of initial response.
Adolescent↗
Antifibrotic and hemodynamic effects of the early and chronic administration of octreotide in two models of liver fibrosis in rats.
The aim of this study was to assess the effect of the early and chronic administration of octreotide in the prevention of hepatic fibrosis and portal hypertension (PHT). Two experimental models of liver fibrosis caused by bile duct ligation (BDL) or CCl4 were divided into 4 rat groups: sham, placebo, and octreotide (10 and 100 micrograms/kg twice daily, subcutaneously). Liver fibrosis was assessed by the area of fibrosis (image analysis), liver hydroxyproline and fibronectin mRNA contents, and serum hyaluronate. Systemic and splanchnic hemodynamic changes were also evaluated, including the splenorenal shunt blood flow by the transit-time ultrasound (TTU) technique. In both models, splenorenal shunt blood flow was significantly lower in the octreotide groups than in the placebo group (P <.05), while portal pressure was not significantly decreased. There was a significant decrease in fibrosis by octreotide in the CCl4 model only: area of fibrosis: 13.9% +/- 3.7% vs. 9.8% +/- 2.5% (P <.01), hydroxyproline: 1.8 +/- 0.6 vs. 1.3 +/- 0.4 mg/g wet liver (P <.05), respectively, placebo vs. octreotide 10 micrograms/kg. There was a significant correlation between the area of fibrosis and hydroxyproline liver content (r =.87 in the biliary model and r =.91 in the CCl4 model; P <.0001). The early and chronic administration of octreotide prevents the development of portocollateral blood flow without reducing portal pressure in two models of liver fibrosis and the development of liver fibrosis in the CCl4 model.
Animals↗
Effects of long-term administration of interferon alpha in two models of liver fibrosis in rats.
BACKGROUND/AIMS: The aim of this study was to assess the effect of the early and chronic administration of interferon alpha in the prevention of hepatic fibrosis and portal hypertension. METHODS: Rats with liver fibrosis due to bile duct ligation or CCl4 were divided into three groups: sham, placebo and interferon alpha2a 100,000 UI/day. Liver fibrosis was assessed by the area of fibrosis (image analysis), liver hydroxyproline and mRNA (fibronectin, procollagen alpha2(I)) contents, and serum hyaluronate. Systemic and splanchnic hemodynamics were also evaluated. RESULTS: Interferon alpha significantly decreased fibrosis in the CCl4 model only: area of fibrosis: 13.9+/-3.7 vs 10.5+/-3.3% (p<0.05), hydroxyproline: 1.8+/-0.6 vs 1.2+/-0.2 mg/g wet liver (p<0.001), respectively placebo vs interferon alpha. There was a significant correlation between the area of fibrosis and hydroxyproline liver content (r=0.77 in the biliary model and r=0.87 in the CCl4 model, p<0.0001). Interferon decreased spleno-renal shunt blood flow (2.0+/-1.8 vs 0.9+/-0.7 ml/min; p<0.05) but not portal pressure in the CCl4 model. No significant effects were observed in rats with biliary fibrosis. CONCLUSIONS: The early and chronic administration of interferon alpha prevents the development of liver fibrosis and porto-collateral circulation in the CCl4 model but not in the biliary model. However, the antifibrotic effects of interferon need to be confirmed in further studies.
Alanine Transaminase↗
The effects of a continuing medical education programme in interpersonal communication skills on doctor practice and patient satisfaction in Trinidad and Tobago.
This study investigates the effects of a brief training programme on the communication skills of doctors in ambulatory care settings in Trinidad and Tobago. Evaluation of doctor performance is based on analysis of audiotapes of doctors with their patients during routine clinic visits and on patient satisfaction ratings. A pre-test/post-test quasi-experimental study design was used to evaluate the effects of exposure to the training programme. Doctors were assigned to groups based on voluntary participation in the programme. Audiotapes of the 15 participating doctors (nine trained and six control) with 75 patients at baseline and 71 patients at the post-training assessment were used in this analysis. The audiotapes were content-coded using the Roter Interaction Analysis System (RIAS). Doctors trained in communication skills used significantly more target skills post-training than their untrained colleagues. Trained doctors used more facilitations in their visits and more open-ended questions than other doctors. There was also a trend towards more emotional talk, and more close-ended questions. Patients of trained doctors talked more overall, gave more information to their doctors and tended to use more positive talk compared to other patients. Trained doctors were judged as sounding more interested and friendly, while patients of trained doctors were judged as sounding more dominant, responsive and friendly than patients of untrained doctors. Consistent with these communication differences, patient satisfaction tended to be higher in visits of trained doctors.
Adult↗
Safety of abrupt discontinuation of fluoxetine: a randomized, placebo-controlled study.
Selective serotonin reuptake inhibitors may be associated with new adverse events after abrupt discontinuation. Hypothesizing that the long half-life of fluoxetine would be protective, this study analyzed the effects of abrupt fluoxetine discontinuation during a randomized, double-blind, placebo-controlled study of depression maintenance treatment. After 12 weeks of fluoxetine treatment (20 mg/day), 395 responders were abruptly randomized to placebo (N = 96) or to continued fluoxetine (N = 299). Patients were seen at weeks 1, 2, 4, and 6 after randomization. Reports of new or worsened adverse events were similar for both groups at each visit after randomization. Patient discontinuations related to adverse events were also similar in both groups. Mild, self-limited lightheadedness or dizziness occurred in a small percentage of patients who discontinued fluoxetine treatment but was of little clinical significance. No cluster of symptoms suggestive of a discontinuation syndrome was observed. Abrupt discontinuation of fluoxetine treatment was well tolerated and did not seem to be associated with significant clinical risk. Fluoxetine may offer a potential safety advantage over shorter-acting agents with respect to treatment interruption and/or discontinuation and may be a better choice for those patients who are likely to miss doses because of travel or forgetfulness.
Adult↗