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PubMed1997

Rare glomerular capillary regeneration and subsequent capillary regression with endothelial cell apoptosis in progressive glomerulonephritis.

Glomerulonephritis (GN) leading to glomerular sclerosis remains an important cause of renal failure. The glomerulus is a capillary network, but endothelial and vascular reactions during progressive GN are not well understood. We have, therefore, examined the morphological alterations of glomerular capillary network and endothelial cells during the progression of damaged glomeruli to glomerular sclerosis. A progressive model of anti-glomerular basement membrane (GBM) GN was induced in Wistar-Kyoto (WKY) rats with a single injection of anti-rat GBM antibody. Severe necrotizing glomerular injuries were observed between day 5 and week 3 with a reduction in the number of total glomerular endothelial cells and total glomerular capillary lumina per glomerular cross sections. In necrotizing lesions, the glomerular endothelial cells were lost with the destruction of the glomerular capillary network. Moreover, angiogenic capillary repair with proliferation of endothelial cells was rare in severely damaged regions of glomeruli. Subsequently, mesangial hypercellularity and marked mesangial matrix accumulation occurred with absence of the development of a capillary network, and the necrotizing lesions progressed to sclerotic scars until 8 weeks. Although active necrotizing lesions could not be seen in damaged glomeruli between week 4 and week 8, the number of apoptotic endothelial cells gradually increased in the glomerular capillaries (0.10 +/- 0.01 apoptotic endothelial cells/glomerular cross section at week 8 versus 0.00 +/- 0.00 control cells (mean +/- SEM; P < 0.05) with the progression of glomerular sclerosis. Whereas the number of apoptotic endothelial cells increased in the damaged glomeruli, the number of total glomerular endothelial cells decreased (9.3 +/- 3.0 cells/glomerular cross section at week 8 versus 24.8 +/- 3.0 cells in control (mean +/- SD); P < 0.001) with regression of glomerular capillaries (3.6 +/- 2.5 capillary lumina/glomerular cross section at week 8 versus 35.0 +/- 5.0 capillary lumina in control (mean +/- SD); P < 0.001). Finally, glomerular endothelial cells could not be detected in the sclerotic lesions in progressive anti-GBM GN in WKY rats. These data indicate that the destruction of the capillary network of glomeruli and subsequent incomplete angiogenic capillary repair leads to glomerular sclerosis in progressive GN. Endothelial cell apoptosis with glomerular capillary regression may also contribute to the development of glomerular sclerosis. Injury of the glomerular capillary network with endothelial cell damage, including apoptosis and subsequent incomplete capillary repair, plays an important role in the progression of glomerular sclerosis during anti-GBM GN in WKY rats.

Animals↗
PubMed1992

Progression rates of cytomegalovirus retinopathy in ganciclovir-treated and untreated patients.

Cytomegalovirus retinopathy lesions in patients with the acquired immunodeficiency syndrome may continue to enlarge despite ganciclovir sodium treatment. In an historical cohort study, we used serial, masked retinal photographs to calculate progression rates for 14 ganciclovir-treated patients known to have disease progression and for 17 untreated patients. The median period of evaluation was 23.5 days for ganciclovir-treated patients and 28 days for untreated patients (P = .89). In both groups, the rate at which borders of preexisting lesions advanced into uninfected retina varied in different directions. Anterior progression rates were usually faster than posterior progression rates. The median progression rate with which disease approached the fovea in ganciclovir-treated patients was 11.5 microns/d (range, 0 to 25.0 microns/d) and the median progression rate for untreated patients was 24.0 microns/d (range, 0 to 164.0 microns/d) (P = .01). These results suggest that ganciclovir provides a therapeutic benefit for patients with progressive disease by slowing the rate with which infection spreads. The size and appearance of lesions may also be related to their response to treatment and to progression rates of untreated disease.

AIDS-Related Opportunistic Infections↗
PubMed1999

Correlation of margin status and extraprostatic extension with progression of prostate carcinoma.

BACKGROUND: The correlation of surgical margins and extraprostatic extension (EPE) with progression is uncertain with regard to prostate carcinoma patients treated by radical prostatectomy. The objective of this study was to define factors predictive of cancer progression; emphasis was placed on surgical margins and their relation to extraprostatic extension. METHODS: The study group consisted of 377 patients who were treated by radical retropubic prostatectomy and bilateral pelvic lymphadenectomy at the Mayo Clinic between 1986 and 1993. All specimens were totally embedded and whole-mounted. Patients ranged in age from 41 to 79 years (mean, 65 years). Those with seminal vesicle invasion or lymph node metastasis and those treated preoperatively with radiation or androgen deprivation were excluded. Final pathologic T classifications were pT2a (41 patients), pT2b (237), and pT3a (99). Progression was defined as biochemical failure (prostate specific antigen [PSA] >0.2 ng/mL), clinical or biopsy-proven local recurrence, or distant metastasis. The mean follow-up was 5.8 years (range, 0.2-11.4 years). Seventy-nine patients who received adjuvant treatment within 3 months after surgery were excluded from survival analysis. RESULTS: The overall margin positivity rate was 29%. Seventy-two patients (19%) had only positive surgical margins without evidence of EPE ("surgical incision"), 53 (14%) had only EPE, 37 (10%) had both, and 215 (57%) had neither. Positive margins were correlated with the finding of EPE (P = 0.003). Progression free survival rates at 5 and 10 years were 88% and 67%, respectively. In univariate analysis, preoperative PSA concentration, positive surgical margins, Gleason grade, cancer volume, and DNA ploidy were significant in predicting progression (P values, <0.001, <0.001, 0.01, 0.007, and <0.001, respectively). In multivariate analysis, margin status and DNA ploidy were independent predictors of progression (relative risk for margin status, 1.9; 95% confidence interval [CI], 1.1-3.4; P = 0.03; relative risk for DNA ploidy, 5.1; 95% CI, 2.4-10.9; P<0.001). Among patients with positive margins, 5-year progression free survival was 78% for those with negative EPE and 55% for those with positive EPE. CONCLUSIONS: Surgical margin status and DNA ploidy were independent predictors of progression after radical prostatectomy. To improve cancer control, adjuvant therapy may be considered for patients with positive surgical margins or nondiploid cancer.

Adult↗
PubMed1997

Progression of atherosclerosis after venous coronary artery bypass graft surgery: a 15-year follow-up study.

We investigated the influence of progression of atherosclerosis on clinical outcome in a cohort of 428 consecutive patients with isolated venous coronary artery bypass graft surgery followed prospectively for 15 years. In 189 patients 307 repeat coronary angiograms were performed because of recurrent signs of ischemia. Progression in the native coronary circulation only was found in 38 angiograms (12%), in both the native circulation and in venous grafts in 66 angiograms (21%), in venous grafts only in 135 angiograms (44%), and no progression was found in 68 angiograms (22%). In all the angiographies with a proven progression in the native coronary arteries, 40% was found to be distal to a vein graft insertion. In multivariate analysis the number of distal anastomoses predicts progression in both the native circulation and in venous grafts. Thus, progression is determined by the extensiveness of coronary artery disease at operation. Also, the interval between operation and repeat angiography predicts progression in the native circulation. We conclude that clinical outcome is also determined by progression in the native coronary circulation. Secondary prevention may, therefore, benefit not only the long-term result in patients with venous bypass grafts but probably also in patients with any type of coronary bypass surgery.

Arteriosclerosis↗
PubMed1985

The relationship between membrane characteristics, functional reactivity of T-lymphocytes, and the progression rate of B-cell chronic lymphocytic leukemia.

Study performed on 192 patients has demonstrated that the progression rate of chronic lymphocytic leukemia (CLL) is associated with the existence of T-cell defect(s). A dynamic classification system based on evaluation of tumor mass growth rate, response to therapy, and myelopoietic failure (MF) has been devised for evaluation of progression rate of CLL. Besides four basic groups (Group 1: CLL without therapy; Group 2: CLL on therapy, without remission; Group 3: CLL on therapy, partial remission; Group 4: CLL on therapy, complete remission) patients were further classified into phase (type) A (stable, indolent CLL) or phase (type) B (active, progressive CLL). The major criteria for phase A were: total tumor mass (TTM) doubling time (DT) longer than 12 months, no MF, and/or good response to therapy. The major criteria for phase B were: TTM DT less than 12 months and/or accompanying MF and/or no response to therapy. The following major findings have been demonstrated: (1) altered quantitative relationship between active and nonactive parts of T-cell compartment (E/A ratio) in the progressive phase of CLL; (2) altered B/T gamma ratio in the progressive phase of CLL; (3) more than 50% increased percentage of T gamma cells in the stable phase of CLL; (4) very low stable and absent seeding efficiency of T-cells in the progressive phase of CLL; (5) altered (delayed) DNA synthesis pattern in the progressive phase of CLL; and (6) negative local xenogeneic graft versus host reaction in the progressive phase of CLL. Based on reported results, a hypothesis regarding the possible role of T-cells in the pathogenesis of CLL was suggested.

Animals↗
PubMed1993

Correlation of pathologic findings with progression after radical retropubic prostatectomy.

BACKGROUND: This study was performed to evaluate the effect of positive margins, Gleason grade, and capsular penetration on progression after radical prostatectomy. METHODS: The authors followed 507 men with totally embedded retropubic prostatectomy specimens performed for clinical Stages A and B prostate cancer for a mean of 3.9 years. RESULTS: Fifty-nine percent of the specimens had negative margins, 37% had focally positive margins, and 4% had extensive positive margins. Although some positive margins were the result of extensive and/or high-grade tumor, in many cases, the tumors only focally reached the capsular margin such that positive margins resulted from an inability to remove additional soft tissue surrounding the prostate. Gleason sum 7 tumors had a significantly higher progression rate compared with Gleason sum 5 or 6 ones, although historically Gleason sum 5-7 lesions had been considered together as intermediate-grade tumors. In a multivariate analysis, positive margins and Gleason sum strongly correlated with progression, whereas capsular penetration did not. Only approximately 50% of patients with positive margins experienced disease progression during 5 years of follow-up. The most common single sites of positive margins were distal (22%), posterior (17%), and posterolateral (14%); 22% of positive margins were extensive. Only four patients (0.8% of the total) had positive margins only in the region of the spared neurovascular bundle and experienced progression. CONCLUSIONS: The most likely explanation for the discrepancy between margins and progression is that some of these margins represented artifactually positive margins caused by the unique problems with handling and assessing radical prostatectomy specimens. Radical prostatectomy provided excellent local control, with only 8% of patients exhibiting local recurrence. Sixty-one percent of men with progression had an elevated serum prostate-specific antigen level as their only manifestation of progression. The significance of isolated elevated serum prostate-specific antigen levels is uncertain, and long-term morbidity and mortality will depend on whether these patients have local disease or occult distant metastases.

Humans↗
PubMed1995

Central nervous system progression of metastatic breast cancer in patients treated with paclitaxel.

BACKGROUND: The possibility of tumor sanctuary sites in the central nervous system (CNS) of patients receiving paclitaxel has been suggested by laboratory data identifying low concentrations of drug in the brain and cerebrospinal fluid (CSF) of rats. METHODS: The pattern of disease progression in patients with metastatic breast cancer who had an initial response to paclitaxel treatment in five Phase II trials at the Memorial Sloan-Kettering Cancer Center was reviewed. RESULTS: Of 152 patients, 53 had a partial or complete response, and 25 had a minor response. Of the 78 patients who responded to paclitaxel, 52 had subsequent disease progression, 22 changed treatments before progression occurred (as specified by the protocol and/or to receive high dose consolidation chemotherapy), 2 stopped receiving treatment because of toxicity, 1 continued receiving treatment, and 1 died with no evidence of disease progression. Six of the 52 patients who progressed after initially responding to paclitaxel had isolated CNS progression while maintaining their systemic response (leptomeningeal metastasis in three, brain metastases in two, brain and leptomeningeal metastases in one). One patient had CNS progression (brain metastases) associated with other systemic sites of progression. All patients with CNS disease developed neurologic symptoms, prompting neurologic evaluation; one had only a mild headache, which was not recognized until evaluation for paclitaxel-related peripheral neuropathy. CONCLUSIONS: These data suggest that the CNS, and particularly the CSF, is an important sanctuary site for patients with metastatic breast cancer receiving paclitaxel.

Blood-Brain Barrier↗
PubMed1982

Autologous and allogeneic mixed lymphocyte reactions in progressive systemic sclerosis.

The autologous and allogeneic mixed lymphocyte reactions (MLR), observed when peripheral blood mononuclear cells from 20 patients with progressive systemic sclerosis were used, were compared with those of age-, sex-, and race-matched normal controls. Such cells were separated by gradient centrifugation of sheep red blood cell (E) rosettes into stimulator (E- or non-T cell) and responder (E + or T cell) populations. The autologous MLR of both the progressive systemic sclerosis and normal peripheral blood mononuclear cells varied widely but there was no statistical difference between the means of each group. In the allogeneic MLR, proliferation between progressive systemic sclerosis non-T cells and normal T cells was significantly less than that of normal non-T cells and progressive systemic sclerosis T cells (P = 0.001). A decreased autologous MLR, while noted with other autoimmune diseases, was lacking in progressive systemic sclerosis. This suggests a different defect. The differences in the allogeneic MLR also suggest that either progressive systemic sclerosis non-T cells were poor stimulators or T cells associated with this disease were better responders when compared with similarly prepared cell populations from normal individuals. The MLR differences could have also resulted from compositional subset alterations or the sharing of a common antigen. HLA-DR5 was found in 9 of the 17 white patients with progressive systemic sclerosis. Although these individuals were evenly distributed as low, medium, and high responders, this finding showed that some progressive systemic sclerosis non-T cells shared a common antigen.

Adult↗
PubMed1996

Clinical and laboratory findings in four patients with the non-progressive hepatic form of type IV glycogen storage disease.

The classic clinical presentation for type IV glycogen storage disease (branching enzyme deficiency, GSD IV) is hepatosplenomegaly with failure to thrive occurring in the first 18 months of life, followed by progressive liver failure and death by age 5 years. Although there have been two patients without apparent liver progression previously reported, no long-term follow-up clinical data have been available. We present here the clinical spectrum of the non-progressive liver form of GSD IV in four patients, and long-term follow-up of the oldest identified patients (ages 13 and 20 years). None has developed progressive liver cirrhosis, skeletal muscle, cardiac or neurological involvement, and none has been transplanted. Branching enzyme activity was also measured in cultured skin fibroblasts from patients with the classic liver progressive, the early neonatal fatal, and the non-progressive hepatic presentations of GSD IV. The residual branching enzyme activity in the patients without progression was not distinguishable from the other forms and could not be used to predict the clinical course. Our data indicate that GSD IV does not always necessitate hepatic transplantation and that caution should be used when counselling patients regarding the prognosis of GSD IV. Patients should be carefully monitored for evidence of progression before recommending liver transplantation.

1,4-alpha-Glucan Branching Enzyme↗
PubMed2003

Cost-utility of interferon beta1b in the treatment of patients with active relapsing-remitting or secondary progressive multiple sclerosis.

Economic evaluations of treatments for multiple sclerosis have focused either on relapsing-remitting or secondary progressive disease. None has addressed specifically the question of how treatments affect disease progression from diagnoses to severe disability; however, in both clinical and economic terms this is one of the key questions. This study therefore created a disease model that includes both relapsing and progressive multiple sclerosis and covers the full range of disease severity. In addition, the issue of covariates influencing the cost per QALY and the uncertainty in the estimates is addressed. The model is based on our earlier approach using a Markov model, where disease progression is measured as functional disability (EDSS), costs and utilities associated with different disability levels, and outcome expressed as QALY. Treatment is based on a subgroup of patients with active disease in two placebo-controlled clinical trials and open-label extensions with interferon-beta(1b) in relapsing-remitting or secondary progressive multiple sclerosis, and natural history data are used for the extrapolation beyond the trials. Disease progression (transition probabilities) was estimated using a probit model controlling for differences in patient and disease characteristics, and costs and utilities for different disability levels are taken from large population-based observational studies. Results are presented for Sweden and compared to the United Kingdom. When treatment is given for 36 months (adjusted for compliance) and no further effect is included, the cost per QALY is EURO 7800 (direct, indirect, and informal care costs included, discounted at 3%) over 10 years. The total number of QALYs increases from 3.45 in the no-treatment group to 3.64 in the treatment group. When treatment is prolonged to 54 months, the cost per QALY is EURO 38,700. Using the full range of costs and utilities, the probability that the cost per QALY over a 20-year time-frame is below EURO 50,000 for patients starting treatment at EDSS 3.0 is 80%. In view of the progression of MS over many years models are required to estimate the cost-effectiveness of new treatments. The model proposed here allows estimating disease progression, costs, and QALYs for patients with different characteristics and types of MS, and it can be adapted to different countries. It can hence be used to assess the cost-effectiveness of a defined intervention, such as interferon-beta(1b).

Journal Article↗
PubMed1983

Progression of coronary artery disease in randomized medical and surgical patients over a 5-year angiographic follow-up.

Progression of coronary artery disease (CAD) was assessed prospectively in a randomized series of 36 medically treated and 42 surgically treated patients with angina pectoris. The medical patients were reexamined after 5 years and the surgical patients 3 weeks, 1 year and 5 years after operation. Sixty-seven percent of the medical patients and 69% of the surgical patients had progression. The frequency of new lesions in initially normal segments after 5 years in the medical group was 6.7%, versus 4.1% in ungrafted normal segments in the surgical group (p = 0.05 less than 0.010). The frequency of progression in abnormal arteries was 24.1% in the medical group, versus 22.6% in the ungrafted arteries of the surgical group (p = 0.90 less than 0.95). The rate of progression of obstructed segments proximal to the graft over 5 years was 43%, versus 27% of the corresponding segments in the medical group (p less than 0.01). Progression took place in 11.6% of normal segments proximal to the graft, versus 2% of the corresponding segments in the medical group (p less than 0.05); 69% of progression occurring in segments proximal to the graft had reached total occlusion, versus 38% of the corresponding segments in the medical group (p less than 0.01). Progression developed in 3.9% of segments distal to the graft, versus 3.1% of the corresponding segments in the medical group. Progression takes place at identical rates in medically treated patients and in ungrafted arteries and segments distal to the graft in surgical patients. Proximal to the graft the rates differ and total occlusions appear as early as 3 weeks after operation.

Coronary Angiography↗
PubMed1994

Platelet aggregation, coronary artery disease progression and future coronary events.

The platelet-aggregatory response, platelet-release factors and markers of thrombin generation in vivo were studied prospectively in 53 patients participating in a randomized clinical trial evaluating the influence of nicardipine on the progression of coronary atherosclerosis. Coronary lesions were measured quantitatively and progression was defined as a decrease in minimum diameter by > or = 0.4 mm. At repeat angiography 24 months after study entry, 20 of the 53 patients had progression of 28 coronary narrowings. Only thrombin-induced enhanced platelet aggregation differentiated patients with from those without coronary disease progression, with an estimated odds ratio of 2.49 (95% confidence interval 1.10 to 5.66). The aggregatory response to adenosine diphosphate, collagen, epinephrine and platelet-activating factor were not different in the 2 groups of patients, nor were measurements of platelet factor 4, beta-thromboglobulin, thromboxane B2, 6-keto-prostaglandin F1 alpha and fibrinopeptide A. During 46.8 months of follow-up after repeat angiography, coronary events occurred in 11 of the 20 with and 6 of the 33 without progression (difference 37%, p = 0.013, confidence interval 11 to 63%). Those with coronary disease progression and an enhanced thrombin-induced platelet aggregation had a worse prognosis than those with no disease progression and a low thrombin-induced platelet aggregation. Thus, patients with coronary disease progression and future coronary events have an enhanced thrombin-induced platelet aggregation. This platelet abnormality may be a marker of increased risk and may play a causative role in the development of coronary events.

6-Ketoprostaglandin F1 alpha↗
PubMed1993

Five-year angiographic follow-up of factors associated with progression of coronary artery disease in the Coronary Artery Surgery Study (CASS). CASS Participating Investigators and Staff.

OBJECTIVES: The Coronary Artery Surgery Study (CASS) required participants to undergo follow-up angiography at 5 years to identify clinical and angiographic features associated with progression of coronary artery disease. BACKGROUND: The CASS randomized 780 patients at 11 participating clinical centers between an initial strategy of medical therapy versus bypass surgery. Five clinical sites accomplished follow-up angiography in > 50% of their randomized subjects within a 42- to 66-month period after the entry arteriogram (n = 314). METHODS: Qualified clinical site angiographers, using side by side film review, evaluated an average of 13 segments/patient on both arteriograms for initial stenosis severity, morphologic features, lesion location and occurrence of disease progression or occlusion. Progression was defined as further definite narrowing by > or = 15% and occlusion as lesion progression to > or = 98%. Lesions were subcategorized as to whether they were univariate and had or had not been treated with bypass surgery. Multivariate logistic regression analyses were performed. RESULTS: For nonbypassed segments, right coronary artery and left anterior descending artery proximal and midlocations were associated with disease progression. For stenosis-containing segments, the initial severity, a non-left anterior descending artery location and increased treadmill duration predicted progression. Segment occlusion was associated with initial lesion severity, right coronary artery location and subsequent interval myocardial infarction. There were few predictors of progression or occlusion in bypassed arteries, other than initial lesion severity. CONCLUSIONS: Univariate and multivariate associations with lesion progression and occlusion included diabetes, lesion location, elevated cholesterol level, interval infarction and lesion morphology. These angiographic results, collected in a prospective trial, are consistent with known risk factors.

Coronary Angiography↗
PubMed2005

Identification of progression markers in B-CLL by gene expression profiling.

OBJECTIVE: B-cell chronic lymphocytic leukemia is a heterogeneous disease with a pronounced variation in the clinical course. With the purpose of identifying genes that could be related to disease progression, we have performed gene expression profiling on B-CLL patients with an indolent disease and patients with a progressive disease with need for therapy. MATERIALS AND METHODS: we applied the Affymetrix GeneChip technique to 11 B-CLL patients with stable and 10 patients with clinically progressive disease. Supervised and unsupervised clustering methods with different algorithms were used to identify genes that tend to give a distinction between stable and progressive disease. RESULTS: The supervised learning procedures identified groups of genes with a combined power to discriminate samples from progressive and stable disease with 70-90% accuracy. The gene for protein phosphatase 2 regulatory subunit B' (B56) gamma isoform (PPP2R5C) and the gene for retinoblastoma-like 2 (p130) (RBL2) were included among the best discriminators; both genes were downregulated in progressive as compared to stable B-CLL. In a hierarchical clustering analysis based on gene expression pattern three clinical subcategories could be identified: one with a more severe clinical outcome, a second one with good prognosis, and a third one that was intermediate between the other two groups. CONCLUSIONS: Our application of microarray analysis on a clinically well defined material has identified a number of genes with combined expression patterns related to stable or progressive disease in general. Unsupervised clustering suggested the existence of subclasses of samples in the progressive group that may be identifiable through gene expression patterns.

Aged↗
PubMed2001

Coronary artery disease progression assessed by electron-beam computed tomography.

The ability to observe changes in atherosclerotic plaque burden over time should provide an accurate measure of efficacy for different cardiovascular therapies. Electron-beam computed tomography (EBCT), by quantification of coronary artery calcification, is a noninvasive measure of atherosclerosis burden. This article summarizes data from abstracts and publications related to coronary artery calcium measurement and its use in progression studies. The issues related to interscan variability and reproducibility of this measure are detailed. The limitations of multidetector spiral computed tomography (high radiation dose and poor reproducibility) are also addressed. Several studies of progression using 2 scans, administered > or =1 year apart, demonstrate significant annual progression (22% to 52% per year). All studies demonstrate that therapy with cholesterol-lowering agents slows the atherosclerotic process, and that it may lead to regression of coronary calcium over time. There are 2 small prognostic studies that demonstrate that coronary events predominantly occur in those patients who exhibit significant progression of coronary artery calcium. Large multicenter trials are underway to evaluate the prognostic significance of coronary artery calcium progression. The progression of coronary artery atherosclerosis can be observed noninvasively by monitoring the progression of coronary calcification with EBCT. With annual progression rates of 22% to 52% and a median interscan variability of only 5% to 8%, this technology provides an opportunity to noninvasively monitor patients to assess the clinical efficacy of medical therapies in studies as short as 1 year.

Calcinosis↗
PubMed1996

Mechanistic imbalance of pulmonary vasomotor control in progressive lung injury.

BACKGROUND: Pulmonary hypertension is the major hemodynamic feature of progressive lung injury. We hypothesized that the mechanisms of pulmonary vasorelaxation become progressively impaired in progressive lung injury. The purpose of this study was to examine the following mechanisms of pulmonary vasorelaxation in a rat model of monocrotaline-induced progressive lung injury: endothelial-dependent cyclic guanosine monophosphate-mediated relaxation (response to acetylcholine), endothelial-independent cyclic guanosine monophosphate-mediated relaxation (response to nitroprusside), beta-adrenergic cyclic adenosine monophosphate-mediated relaxation (response to isoproterenol), and hypoxic pulmonary vasoconstriction. METHODS: Rats were studied 2, 7, and 14 days after monocrotaline injection (100 mg/kg intraperitoneally). Pulmonary vasomotor control mechanisms were studied in isolated pulmonary artery rings. Controls were studied 14 days after saline injection. Statistical analysis was by ANOVA; p < 0.05 was considered significant. RESULTS: A progressive impairment of pulmonary vasorelaxation was observed. By 14 days after monocrotaline injection acetylcholine produced only 25% +/- 5% relaxation versus 95% +/- 5% in controls (p < 0.05), nitroprusside produced 46% +/- 5% relaxation versus 100% in controls (p < 0.05), and isoproterenol produced only 18% +/- 5% relaxation versus 94% +/- 4% in controls (p < 0.05). At the same time hypoxic pulmonary vasoconstriction became progressively exaggerated. CONCLUSIONS: Progressive dysfunction of pulmonary vasomotor control may contribute to the pulmonary hypertension seen in progressive lung injury.

Animals↗
PubMed1999

Human xenografts, human skin and skin reconstructs for studies in melanoma development and progression.

Melanoma develops from a series of architectural and phenotypically distinct stages and becomes progressively aggressive. Considerable progress has been made in understanding the biological, pathological, and immunological aspects of human melanoma. Genetic and cytogenetic studies have revealed broad chromosomal abnormalities and wide mutational spectra. Precise biological and molecular determinants responsible for melanoma progression are not yet known. This is in part due to lack of experimental models that mimic human melanomas. Experimental models in melanoma should not only identify cause and origin of malignancy, but also should represent the ordered progression steps that culminate in metastasis to distant organs. Currently, there are several mouse and other vertebrate melanoma models under investigation; several of them promise to shed light on mechanisms of melanomagenesis. However, many of them suffer from lack of context to human skin architecture and hence, are of basic interest. The lack of appropriate models impeded the efforts to understand origin, etiology, progression and ultimately therapeutic benefits to humans. Development of human skin-mouse chimeric models has appeal because it mimics human diseases. In addition, human artificial skin constructs in vitro promises to be a versatile and efficient model to study not only origin and mechanisms of melanoma, but also progression. This review will focus on the recent progress in establishing tumor models in melanoma in general and their relevance to human melanoma as molecular determinants of tumor progression.

Animals↗
PubMed2002

Changes of the ganglioside pattern and content in human fibroblasts by high density cell population subculture progression.

In this study we show that the ganglioside content and pattern of human skin fibroblasts change along the process of cell subculture progression by varying the cell density. GM3, GD3 and GD1a were components of the total cell ganglioside mixtures extracted from cells, but GD1a was in all the extracts a minor component or very scant. Other gangliosides present in traces were not characterised. The fibroblast ganglioside content of 52 pools of cells obtained from 5 different cell lines cultured at variable cell density ranged from 2.0 to 13.1 nmoles per mg of cell protein. The molar ratio between GM3 and GD3 varied from 418 to 0.6 in the ganglioside mixtures, as determined by densitometric quantitative analysis after thin layer chromatographic separation. Both the ganglioside content and the GM3/GD3 molar ratio were constant along several passages of subculture progression performed by plating cells collected at confluence. Instead, when the subculture progression was performed by plating cells collected at a few days after reaching confluence, a progressive increase of the ganglioside content was observed. GD3 increased proportionally more than GM3 so that a progressive decrease of the ratio between GM3 and GD3 was observed. In some experiments, GD3 was very scant at the beginning of the progression, while it was near 30% after 5 passages under these conditions. The progressive increase of GD3 along the high density cell population subculture progression was associated to a moderate increase of the mRNA GD3 synthase.

Blotting, Northern↗