Ten modifiable health risk factors are linked to more than one-fifth of employer-employee health care spending.

An underlying premise of the Affordable Care Act provisions that encourage employers to adopt health promotion programs is an association between workers' modifiable health risks and increased health care costs. Employers, consultants, and vendors have cited risk-cost estimates developed in the 1990s and wondered whether they still hold true. Examining ten of these common health risk factors in a working population, we found that similar relationships between such risks and total medical costs documented in a widely cited study published in 1998 still hold. Based on our sample of 92,486 employees at seven organizations over an average of three years, $82,072,456, or 22.4 percent, of the $366,373,301 spent annually by the seven employers and their employees in the study was attributed to the ten risk factors studied. This amount was similar to almost a quarter of spending linked to risk factors (24.9 percent) in the 1998 study. High risk for depression remained most strongly associated with increased per capita annual medical spending (48 percent, or $2,184, higher). High blood glucose, high blood pressure, and obesity were strongly related to increased health care costs (31.8 percent, 31.6 percent, and 27.4 percent higher, respectively), as were tobacco use, physical inactivity, and high stress. These findings indicate ongoing opportunities for well-designed and properly targeted employer-sponsored health promotion programs to produce substantial savings.

Treatment of post-implantation aneurysm growth by laparoscopic sac fenestration: long-term results.

OBJECTIVES: Sac growth after endovascular aneurysm repair (EVAR) is an important finding, which may influence prognosis. In case of a type II endoleak or endotension, clipping of side branches and subsequent sac fenestration has been presented as a therapeutic alternative. The long-term clinical efficacy of this procedure is unknown. METHODS: The study included eight patients who underwent laparoscopic aortic collateral clipping and sac fenestration for enlarging aneurysms following EVAR. Secondary interventions and clinical outcome were retrieved from hospital records. Sac behaviour was evaluated measuring volumes on periodical computed tomography angiography (CTA) imaging using dedicated software. RESULTS: Follow-up had a median length of 6.6 (range 0.6-8.6) years. During this time, only three patients successfully achieved durable aneurysm shrinkage (n = 2) or stability (n = 1). The remaining patients suffered persistent (n = 2) or recurrent sac growth (n = 3), all regarded as failure of fenestration. A total of six additional interventions were performed, comprising open conversion (n = 2), relining (n = 1) and implantation of iliac extensions (n = 3). All additional interventions were successful at arresting further sac growth during the remainder of follow-up. CONCLUSIONS: Despite being a less invasive alternative to conversion and open repair, the long-term outcome of sac fenestration is unpredictable and additional major procedures were often necessary to arrest sac growth.

Indoleamine 2,3-dioxygenase as a modifier of pathogenic inflammation in cancer and other inflammation-associated diseases.

Chronic inflammation underlies the basis for development and progression of cancers and a variety of other disorders, but what specifically defines its pathogenic nature remains largely undefined. Recent genetic and pharmacological studies in the mouse suggest that the immune modulatory enzyme indoleamine 2,3-dioxygenase (IDO), identified as an important mediator of immune escape in cancer, can also contribute to the development of pathology in the context of chronic inflammatory models of arthritis and allergic airway disease. IDO-deficient mice do not display spontaneous disorders of classical inflammation and small molecule inhibitors of IDO do not elicit generalized inflammatory reactions. Rather, in the context of a classical model of skin cancer that is promoted by chronic inflammation, or in models of inflammation-associated arthritis and allergic airway disease, IDO impairment can alleviate disease severity. Here we offer a survey of preclinical literature suggesting that IDO functions as a modifier of inflammatory states rather than simply as a suppressor of immune function. We propose that IDO induction in a chronically inflamed tissue may shape the inflammatory state to support, or in some cases retard, pathogenesis and disease severity.

Decision-making in type-B dissection: current evidence and future perspectives.

Aortic dissection is a devastating cardiovascular condition with an incidence of 3,5:100 000. It is classified according to anatomic extent, mechanism of lesion, duration from index event and course (uncomplicated vs. complicated). Intramural hematoma and penetrating aortic ulcers share many of the features of classic dissections, but tend to occur in older patients with advanced atherosclerosis. In uncomplicated type-B dissection, conservative treatment with tight blood pressure and heart rate control is safe and effective. Early stent-graft implantation may, however, result in more favorable aortic remodeling and reduced late complications. For acute complicated cases intervention is usually required. Stent-graft coverage of the entry tear frequently resolves malperfusion, but the role of the false lumen in organ perfusion must be assessed and endovascular revascularization performed if necessary. In chronic type-B dissections, coverage of the entry tear likely results in continued pressurization of the false lumen due to rigidity of the dissecting membrane and distal fenestrations. Better understanding of the different disease mechanisms involved, imaging advances and introduction of dedicated stent-grafts are expected to further improve patient outcomes in the future. Primary and secondary pharmacological prevention, stricter follow-up protocols and screening of family members may also prove valuable. Better patient selection will allow preventive treatment with low morbidity for those at higher risk of complications.

Device-specific outcomes after endovascular abdominal aortic aneurysm repair.

Over the last decade, endovascular aneurysm repair (EVAR) has been used extensively for the elective treatment of infra-renal abdominal aneurysms. However, it remains unclear how specific devices perform and how they compare to others. We provide an overview of currently used endografts, and discuss the current evidence regarding device-specific outcomes. Published literature confirms differences in results according to endograft selection. These differences were more pronounced with older generations of devices, in comparison to newer models. Contemporary results are generally good and one should remember that no randomized data exist regarding individual device performance. Moreover, by the time there is enough follow-up to draw conclusions, the data is relatively obsolete due to constant improvements in endograft technology and design. Results from EVAR have been steadily improving and individualized device selection has shown to be valuable. It appears that patients with favorable anatomy do well with most modern endografts. Those with challenging anatomies may benefit more from a particular design, delivery and deployment feature requiring greater knowledge and experience for adequate device selection.

Ha-Ras transformation of MCF10A cells leads to repression of Singleminded-2s through NOTCH and C/EBPbeta.

We have previously shown that Singleminded-2s (SIM2s), a member of the basic helix-loop-helix Per-Arnt-Sim (bHLH/PAS) family of transcription factors, is downregulated in breast cancer samples and has tumor suppressor activity. However, the mechanism by which SIM2s is repressed in breast cancer cells has not been determined. In this study, we show that transformation of MCF10A cells by Harvey-Ras (Ha-Ras) induces CCAAT/enhance binding protein beta (C/EBPbeta) and activates the NOTCH signaling pathway to block SIM2s gene expression. NOTCH-mediated repression acts through a C-repeat binding factor 1 (CBF1)-independent mechanism, as introduction of CBF1 had no effect on SIM2s expression. Consistent with C/ebpbeta-dependent inhibition of SIM2s, C/ebpbeta(-/-) mouse mammary glands express high levels of SIM2s and reestablishment of C/ebpbeta isoforms decreased SIM2s mRNA levels in C/ebpbeta immortalized mammary epithelial cell lines. These studies illustrate a novel pathway of tumor suppressor gene silencing in Ha-Ras-transformed breast epithelial cells and identify SIM2s as a target of C/EBPbeta and NOTCH signaling.

Effects of a managed chiropractic benefit on the use of specific diagnostic and therapeutic procedures in the treatment of low back and neck pain.

OBJECTIVE: The aim of this study was to measure the effects of a managed chiropractic benefit on the rates of specific diagnostic and therapeutic procedures for the treatment of back pain and neck pain. DESIGN: This study is a retrospective analysis of claims data from a managed-care health plan over a 4-year period. The use rates of advanced imaging, surgery, inpatient care, and plain-film radiographs were compared between employer groups with and without a chiropractic benefit. RESULTS: For patients with low back pain, the use rates of all 4 studied procedures were lower in the group with chiropractic coverage. On a per-episode basis, the rates in the group with coverage were reduced by the following: surgery (-32.1%); computed tomography (CT)/magnetic resonance imaging (MRI) (-37.2%); plain-film radiography (-23.1%); and inpatient care (-40.1%). On a per-patient basis, the rates were reduced by the following: surgery (-13.7%); CT/MRI (-20.3%); plain-film radiography (-2.2%); and inpatient care (-24.8%). For patients with neck pain, the use rates were reduced per episode in the group with chiropractic coverage as follows: surgery (-49.4%); CT/MRI (-45.6%); plain-film radiography (-36.0%); and inpatient care (-49.5%). Per patient, the rates were surgery (-31.1%); CT/MRI (-25.7%); plain-film radiography (-12.5%); and inpatient care (31.1%). All group differences were statistically significant. CONCLUSION: For the treatment of low back and neck pain, the inclusion of a chiropractic benefit resulted in a reduction in the rates of surgery, advanced imaging, inpatient care, and plain-film radiographs. This effect was greater on a per-episode basis than on a per-patient basis.

Cervical artery dissection: An atypical presentation with Ehlers-Danlos-like collagen pathology?

The authors took skin biopsies of the macroscopically normal skin of seven consecutive patients with spontaneous cervical artery dissection (SCAD). Histologically, alterations of the collagen and elastic fiber networks were found in six patients. In five, the histologic, immunohistochemical, and ultrastructural changes were similar to those usually found in Ehlers-Danlos syndrome (EDS). This suggests that SCAD is frequently associated with the dermal alterations seen in EDS.

Comparative analysis of individuals with and without chiropractic coverage: patient characteristics, utilization, and costs.

BACKGROUND: Back pain accounts for more than $100 billion in annual US health care costs and is the second leading cause of physician visits and hospitalizations. This study ascertains the effect of systematic access to chiropractic care on the overall and neuromusculoskeletal-specific consumption of health care resources within a large managed-care system. METHODS: A 4-year retrospective claims data analysis comparing more than 700 000 health plan members with an additional chiropractic coverage benefit and 1 million members of the same health plan without the chiropractic benefit. RESULTS: Members with chiropractic insurance coverage, compared with those without coverage, had lower annual total health care expenditures ($1463 vs $1671 per member per year, P<.001). Having chiropractic coverage was associated with a 1.6% decrease (P = .001) in total annual health care costs at the health plan level. Back pain patients with chiropractic coverage, compared with those without coverage, had lower utilization (per 1000 episodes) of plain radiographs (17.5 vs 22.7, P<.001), low back surgery (3.3 vs 4.8, P<.001), hospitalizations (9.3 vs 15.6, P<.001), and magnetic resonance imaging (43.2 vs 68.9, P<.001). Patients with chiropractic coverage, compared with those without coverage, also had lower average back pain episode-related costs ($289 vs $399, P<.001). CONCLUSIONS: Access to managed chiropractic care may reduce overall health care expenditures through several effects, including (1) positive risk selection; (2) substitution of chiropractic for traditional medical care, particularly for spine conditions; (3) more conservative, less invasive treatment profiles; and (4) lower health service costs associated with managed chiropractic care. Systematic access to managed chiropractic care not only may prove to be clinically beneficial but also may reduce overall health care costs.

Carotid endarterectomy in octogenarians with symptomatic high-grade internal carotid artery stenosis: long-term clinical and duplex follow-up.

The objective of this study was to evaluate the clinical and duplex outcome after carotid endarterectomy (CEA) in recently symptomatic patients aged 80 years or older. Information was assembled from a prospective data collection of all CEAs performed from January 1986 to December 1999. Included were all patients with recently symptomatic carotid artery stenosis who were aged 80 years or older at time of operation. Thirty-two patients, with a mean age of 82 years, were included. Outcome events were stroke, death, and restenosis (more than 50% diameter reduction) during routine duplex scan follow-up. Conventional surgical technique was used regarding anesthesia and selective shunting or patching. None of the operated-on patients suffered a stroke at any time during follow-up. One patient (3.1%) died in the early postoperative phase (<30 days). An additional 8 patients died during follow-up. None of these deaths were of cerebrovascular origin. Survival at 3 years was 73% (life table analysis). Routine duplex scan follow-up showed 2 patients with a diameter reduction of more than 50%, both 3 months after CEA. Restenosis rate on duplex scan was 7.4% after 1 year. The authors conclude that there seems to be no reason to deny the very elderly the benefits of CEA. Stroke-free survival and survival rates show that carotid surgery is a safe procedure in patients aged 80 and over who are in apparently good health. These findings are supported by a low incidence of restenosis on duplex scan follow-up, indicating a durable repair.

The effects of small-dose ketamine on propofol sedation: respiration, postoperative mood, perception, cognition, and pain.

We compared the effects of coadministration of propofol and small-dose ketamine to propofol alone on respiration during monitored anesthesia care. In addition, mood, perception, and cognition in the recovery room, and pain after discharge were evaluated. In the Propofol group (n = 20), patients received propofol 38 +/- 24 microg x kg(-1) x min(-1). The Coadministration group (n = 19) received propofol 33 +/- 13 microg x kg(-1) x min(-1) and ketamine 3.7 +/- 1.5 microg x kg(-1) x min(-1). Respiration was assessed by using end-expiratory PCO(2) measurements at nasal prongs. After surgeries, mood, perception, and thought were assessed by using visual analog scales, and cognition was assessed by Mini-Mental State Examination (MMSE). Pain after discharge was assessed by a five-point rating scale in the evening for 5 days. End-expiratory PCO(2) was lower in the Coadministration group (P < 0.0001). Mood and MMSE scores were higher in the Coadministration group (P < 0.004 and P = 0.001, respectively). Pain scores and analgesic consumption after discharge were less in the Coadministration group (P = 0.0004 and P < 0.0001, respectively). We conclude that coadministration of small-dose ketamine attenuates propofol-induced hypoventilation, produces positive mood effects without perceptual changes after surgery, and may provide earlier recovery of cognition.

Carbon dioxide laser abrasion. Is it appropriate for all regions of the face?

OBJECTIVES: To evaluate the effectiveness of the carbon dioxide laser for treatment of facial acne scarring and to determine if certain regions of the face would respond more favorably to carbon dioxide laser resurfacing than other areas of the face. METHODS: Twenty-five patients with facial acne scarring were treated with the carbon dioxide laser with the flash-scanning attachment. Physician and patient evaluations were performed at postoperative follow-up. The face was evaluated for improvement by 5 anatomic regions: medial and lateral cheeks, perioral region, temple, and forehead. SETTING: Office ambulatory surgery center. RESULTS: Patients demonstrated overall improvement with the carbon dioxide laser. However, certain areas, such as the lateral cheek and temple, responded less favorably than other areas, such as the medial cheek, perioral region, and forehead. These findings were found to be statistically significant (P < .001) for physician and patient assessments. No long-term complications were reported. CONCLUSIONS: The carbon dioxide laser is an effective modality for the treatment of facial acne scarring. Physician and patient satisfaction is high. Nevertheless, multiple treatments may be necessary to achieve improvement, especially in the temple and lateral cheek areas; these anatomic sites respond less favorably to laser resurfacing than the medial cheek, perioral region, and forehead.

Involvement of hepatocyte nuclear factor 1 in the regulation of the UDP-glucuronosyltransferase 1A7 (UGT1A7) gene in rat hepatocytes.

UDP-glucuronosyltransferase 1A7 (UGT1A7) is a major UGT contributing to the glucuronidation of xenobiotic phenols in rats. Its expression in rat liver is tightly regulated, with low constitutive and high inducible expression in response to aryl hydrocarbon receptor ligands and oltipraz. Previously, we reported the absence of 3-methylcholanthrene- or oltipraz-responsive elements in the 1.6-kbp region flanking the UGT1A7 promoter. However, potential binding sites were noted for several liver-enriched transcription factors. Here we show that deletion of the hepatic nuclear factor (HNF)3, HNF4, and CCAAT-enhancer binding protein-like binding sites had no effect on the expression of a UGT1A7 reporter plasmid, p(-965/+56)1A7-Luc, in primary rat hepatocytes. The full activity of the promoter was contained in the region between bases -157 and +76. Two sites of binding by rat liver nuclear proteins were detected in this region by DNase footprinting. PR-1 corresponded to the HNF1-like binding site between bases -52 and -38, whereas PR-2 was located between -30 to -6. Gel retardation studies supported the presence of HNF1alpha in the PR-1 DNA-liver nuclear protein complex. Mutation of PR-1 inhibited binding in the gel shift assay, prevented activation by overexpressed HNF1 in human embryonic kidney cells, and reduced by >80% the maximal luciferase activities expressed from basal and 3-methylcholanthrene-responsive UGT1A7 gene reporter constructs in primary rat hepatocytes. These data provide evidence for an important stimulatory role of HNF1 in promoting UGT1A7 gene expression in rat liver.

Post cardiac surgery phrenic nerve palsy: value of plication and potential for recovery.

OBJECTIVES: Evaluation of an aggressive policy for the treatment of phrenic nerve palsy (PNP), following cardiac operations, with emphasis on early diaphragmatic plication. Attention was given to the incidence and predisposing factors for PNP and the potential for recovery following plication. METHODS: From 1 June 1991 to 1 January 1996 we prospectively screened patients for PNP following cardiac surgery. The diagnosis was suspected if difficulty was experienced in weaning the child from the ventilator. If abnormal elevation of the hemidiaphragm was present diaphragmatic plication was performed. Echocardiography was used to assess subsequent return of diaphragmatic function. RESULTS: Seventeen children (nine boys, eight girls), out of 867 (1.9%) children younger than 16 years of age, undergoing cardiac operations were found to have PNP. The mean age was 66 days (range 1-17 months) with 16 patients below 1 year out of a total of 285 patients (incidence 5.6%) and one patient 17 months old. The incidence following open procedures was 11/190, following closed procedures 2/95 and following reoperation 4/83. PNP was diagnosed from 2 to 44 days (mean 14 days) following surgery. It was present on the right side in seven cases, the left in nine and was bilateral in one patient. Two patients were extubated at the time of diagnosis, one patient could be extubated shortly thereafter. Fourteen children underwent diaphragmatic plication, at a median 5 days post diagnosis. Extubation was possible 1-60 days (mean 4 days) after plication. Mean follow-up was 19 +/- 5 months. Subsequent recovery of diaphragmatic movement was documented in seven (41%) children. Time to recovery following plication was 16 months, without plication 38 months. CONCLUSION: Prospective screening for PNP revealed an incidence in children younger than 1 year of 6%. Early plication substantially reduces the duration of ventilation, with its associated reduced morbidity and ICU stay.

Transcriptional activation of the UDP-glucuronosyltransferase 1A7 gene in rat liver by aryl hydrocarbon receptor ligands and oltipraz.

UDP-glucuronosyltransferase UGT1A7 catalyzes the glucuronidation of benzo(a)pyrene metabolites and other bulky aromatic compounds. Both UGT1A7 mRNA and an associated enzyme activity (benzo(a)pyrene7, 8-dihydrodioltransferase activity) are markedly increased in livers of rats treated with beta-naphthoflavone or 4-methyl-5-pyrazinyl-3H-1,2-dithiole-3-thione (oltipraz). Nuclear runoff assays show that the effects of both inducers are primarily due to transcriptional activation. A 27-kilobase region that included the UGT1A7/UGT1A6 promoter regions was cloned. Primer extension and RNase protection studies indicated >/=30 transcription start sites in five clusters between bases -85 and -40 respective to the translation start codon. There was no recognizable TATA box, but the promoter region is TA-rich. Sequence analysis revealed potential binding sites for CCAAT enhancer-binding protein, activator protein 1, and hepatic nuclear factors 1, 3, and 4, but no xenobiotic response elements or antioxidant response elements, implicated in the regulation of other genes by beta-naphthoflavone or oltipraz, were found. A UGT1A7 gene reporter plasmid directed strong constitutive expression in transient transfection assays using primary rat hepatocytes. Treatment with 3-methylcholanthrene or oltipraz had no effect compared with similarly treated pGL3-Basic-transfected cells. These results suggest that the regulatory elements controlling xenobiotic inducibility of UGT1A7 transcription are located either 5' or 3' of bases -1600 to +54. One possibility is that the polycyclic aromatic-mediated regulation of UGT1A7 occurs via the xenobiotic response element flanking the UGT1A6 locus 7 kilobase pairs downstream.

The carbon dioxide laser. An alternative for the treatment of actinically damaged skin.

BACKGROUND: The treatment of complex and diffuse actinic keratoses involving the face presents a problem in that they frequently recur despite traditional treatment modalities. The carbon dioxide (CO2) laser is an effective method for resurfacing actinically damaged facial skin. OBJECTIVE: The purpose of this study is to show the usefulness of the CO2 laser for the treatment of actinically damaged skin in patients with proven actinic keratoses and squamous cell carcinoma in situ of the face. METHODS: In an office surgery setting, the Sharplan 1030 or 40C CO2 laser with the SilkTouch flashscanner attachment was utilized to treat various regions of the face in 14 patients. RESULTS: All patients were satisfied with the aesthetic outcome of their laser procedures and no clinical evidence of residual or recurrent lesions have been noted. There were no long-term complications reported. CONCLUSIONS: Based on this preliminary report, the CO2 laser appears to be an excellent alternative for the surgical treatment of premalignant lesions of the face and can be used effectively without significant complications.

1alpha,25-dihydroxyvitamin D3 activates T cells of tumor bearers through protein phosphatase 2A.

The sterol 1alpha,25-dihydroxyvitamin D3 [1,25(OH)2D3] can inhibit T cell activation as well as restore the functional competence of suppressed T cells, The present studies determined whether 1,25(OH)2D3 had a differential effect on the activation of normal T cells or of suppressed T cells from mice bearing Lewis lung carcinoma tumors. Normal spleen cell proliferation in response to immobilized anti-CD3 was unaffected by the lower doses of 0.1-10 nM 1,25(OH)2D3, and was inhibited by the higher dose of 100 nM 1,25(OH)2D3. In contrast, 1,25(OH)2D3 increased proliferation and interferon gamma secretion by T cells of tumor bearers in response to stimulation through T cell receptor/CD3. Assessment of mechanisms associated with the 1,25(OH)2D3 stimulation of tumor-bearer T cells implicated protein phosphatase 2A (PP-2A). First, PP-2A activity of spleen cells from tumor bearers was reduced compared to that of normal spleen cells but was increased by 1,25(OH)2D3. Second, 1,25(OH)2D3 stimulation of tumor-bearer T cell proliferation was dependent on this PP-2A activity as it was blocked by doses of okadaic acid that selectively inhibit PP-2A. These results suggest that 1,25(OH)2D3 preferentially enhances the responsiveness of immunosuppressed T cells from tumor bearers to TCR/CD3 stimulation by restoring PP-2A activity.

Identification of a rat oltipraz-inducible UDP-glucuronosyltransferase (UGT1A7) with activity towards benzo(a)pyrene-7,8-dihydrodiol.

Previous work has shown that polycyclic aromatic hydrocarbons and oltipraz both induce an unidentified rat liver UDP-glucuronosyltransferase with activity toward benzo(a)pyrene-7, 8-diol, the proximate carcinogenic form of benzo(a)pyrene. Here we report the isolation of a benzo(a)pyrene-7,8-diol transferase-encoding cDNA, LC14, from an adult rat hepatocyte-derived cell line (RALA255-10G LCS-3). The predicted amino acid sequence of LC14 is nearly identical (5 differences out of 531 residues) to that deduced from UGT1A7, recently cloned at the genomic DNA level (Emi, Y., Ikushiro, S., and Kyanagi, T. (1995) J. Biochem. (Tokyo) 117, 392-399). Northern analysis of RNA from female F344 rat liver and LCS-3 cells revealed over a 40-fold and 4.4-fold enhancement by oltipraz treatment, respectively. Benzo(a)pyrene-7, 8-diol glucuronidating activity was detected (0.4 nmol/10(6) cells/16 h) in AHH-1 cells transfected with the LC14 expression vector, pMF6-LC14-3. The LC14-encoded transferase exhibited even higher activity toward certain benzo(a)pyrene phenols, including the major 3- and 9-phenol metabolites (4.1 and 2.8 nmol/10(6) cells/16 h, respectively). The Km of the enzyme for (-)-trans benzo(a)pyrene-7, 8-diol and 3-OH-BP was 15.5 and 12.3 microM, respectively. Northern analyses of total RNA revealed expression of LC14 or LC14-like RNA in all extrahepatic tissues tested. Marked inducibility by oltipraz was observed only in liver and (to a lesser extent) intestine. The results suggest that induction of UGT1A7 may explain the increased glucuronidating activities toward benzo(a)pyrene-7,8-diol and other metabolites that occur following treatment with polycyclic aromatic hydrocarbon-type inducing agents and oltipraz. UGT1A7 appears to represent an important cellular chemoprotective enzyme which mediates conjugation and elimination of toxic benzo(a)pyrene metabolites.

Protein phosphatase-2A associates with the cytoskeleton to maintain cell spreading and reduced motility of nonmetastatic Lewis lung carcinoma cells: the loss of this regulatory control in metastatic cells.

Metastatic Lewis lung carcinoma (LLC-LN7) variants have previously been shown to have reduced levels of protein phosphatase-2A (PP-2A) activity as compared to the nonmetastatic LLC-C8 cells. The present study showed that inhibition of PP-2A in the nonmetastatic LLC-C8 cells caused a rapid change from a spread to a rounded morphology and increased their in vitro invasiveness through laminin. In contrast, the metastatic LLC-LN7 cells were rounded and invasive, which was not affected by inhibition of PP-2A. To determine whether these differences could be attributed to alterations in PP-2A association with the cytoskeleton, the extent of PP-2A colocalization with microtubules was tested. Immunostaining for tubulin showed prominent filamentous fibers in nonmetastatic LLC-C8 cells and small foci of PP-2A immunostaining along these microtubules. In contrast, the tubulin staining was diffuse throughout the metastatic LLC-LN7 cells and there was little evidence of association with PP-2A. Western blot analyses showed that this reduced level of PP-2A association with microtubules in metastatic LLC-LN7 cells was not due to differences in levels of the PP-2A subunits. Instead, it may be due to the reduced association of the subunits into the heterotrimeric form of the PP-2A holoenzyme. These studies show the importance of PP-2A in maintaining a spread morphology and in restricting invasiveness, and a loss of this regulatory control in metastatic cells. This loss of PP-2A regulatory control in metastatic cells may be due to a reduction in the trimeric form of the PP-2A holoenzyme.