Propofol hemisuccinate suppression of experimental autoimmune encephalomyelitis.

Propofol hemisuccinate is a prodrug water soluble form of the lipophilic, phenolic compound propofol (2,6-di-isopropylphenol), that is the active ingredient in the widely used anesthetic agent Diprovan. Propofol binds to GABA(A) receptors but also has a phenolic structure that confers antioxidant properties to the molecule. The effects of propofol hemisuccinate in rat experimental autoimmune encephalomyelitis (EAE) were studied using different doses and time regimes. Propofol hemisuccinate, 100 mg/kg given three times a day from day 7 or day 12 until day 16 after disease initiation, significantly reduced maximal EAE score. Histology studies supported the clinical findings demonstrating reduction in the inflammatory response in the lumbar spinal cord in animals treated with propofol hemisuccinate. Decreased levels of nitrotyrosine and unchanged levels of induced nitric oxide synthase suggest propofol hemisuccinate crossed the blood brain barrier and exerted its effects by lowering reactive oxygen species levels. The results suggest that propofol hemisuccinate may provide an alternative mode of treatment for acute exacerbations of multiple sclerosis.

TGF-beta-induced invasiveness of pancreatic cancer cells is mediated by matrix metalloproteinase-2 and the urokinase plasminogen activator system.

TGF-beta strongly promotes local tumor progression in advanced epithelial tumors, though the underlying mechanisms are poorly understood. In the present study, we demonstrate the potential of TGF-beta to increase the invasiveness of the pancreatic cancer cell lines PANC-1 and IMIM-PC1. TGF-beta-induced tumor cell invasion occurred in a time-dependent manner, started after 12 hr and continued to increase even 48 hr after a single application of the growth factor. Blocking of secreted TGF-beta1 by application of neutralizing antibodies 24 hr after TGF-beta treatment completely prevented the sustained effects of TGF-beta on tumor cell invasion. Together with our previous observation that TGF-beta1 up-regulates its own expression in both cell lines, our data suggest that TGF-beta1 acts in an autocrine manner to maintain tumor cell invasion. As measured by Northern blot hybridization and zymography, TGF-beta treatment of PANC-1 and IMIM-PC1 cells resulted in strong up-regulation of expression and activity of both matrix metalloproteinase-2 (MMP-2) and the urokinase plasminogen activator (uPA) system. Treatment with MMP inhibitors or inhibitors of the uPA system caused significant reduction of TGF-beta-induced invasiveness in both cell lines. In contrast, expression and activity of MMP-2 and uPA as well as tumor cell invasiveness remained unaffected in cell lines with defects of the TGF-beta type II receptor (MiaPaca2) or the Smad4 gene (IMIM-PC2 and CAPAN-1). In these cell lines, TGF-beta also failed to auto-induce its own expression. In conclusion, our results suggest that TGF-beta1 is a strong promotor of pancreatic cancer progression. TGF-beta thereby acts in an autocrine manner to induce tumor cell invasion, which is mediated by MMP-2 and the uPA system.

Transforming growth factor beta1 treatment leads to an epithelial-mesenchymal transdifferentiation of pancreatic cancer cells requiring extracellular signal-regulated kinase 2 activation.

The aim of this study was to examine the effects of transforming growth factor (TGF) beta1 on the phenotype and the biological behavior of pancreatic cancer cell lines with and without mutations in the TGF-beta signaling pathway and to elucidate whether the Ras signaling cascade participates in mediating these effects of TGF-beta1. TGF-beta-responsive (PANC-1, COLO-357, and IMIM-PC1) and nonresponsive (CAPAN1 and IMIM-PC2) pancreatic cancer cell lines with activating mutations of the Ki-Ras oncogene were treated with 10 ng/ml TGF-beta1 over time. Phenotypic alterations were studied by electron and phase contrast microscopy and by immunohistochemistry and expression analyses of differentiation markers. The influence of TGF-beta on tumor cell scattering, migration, and invasion was determined. The role of the Ras-mitogen-activated protein kinase kinase (MEK)-extracellular signal-regulated kinase (ERK) cascade in mediating TGF-beta-induced morphological and functional effects were studied by pretreatment with the MEK1 inhibitor PD 98059 and by measuring ERK2 activation using immune complex kinase assays. TGF-beta1 led to a reversible and time-dependent epithelial-mesenchymal transdifferentiation (EMT) in TGF-beta-responsive pancreatic cancer cell lines, characterized by a fibroblastoid morphology and an up-regulation of mesenchymal markers and a down-regulation of epithelial markers. EMT was associated with an increase in tumor cell migration, invasion, and scattering. In the responsive cell lines, TGF-beta1 induced a moderate but sustained activation of ERK2. EMT, the concomitant changes in gene expression, and the invasive and migratory potential were reduced or abolished by pretreatment with the selective MEK1 inhibitor. Thus, in TGF-beta-responsive pancreatic cancer cells with activating Ki-Ras mutations, TGF-beta1 treatment caused an EMT associated with a more invasive phenotype. Cross-talk with the Ras-MEK-ERK-signaling cascade appears to be essential for mediating these effects of TGF-beta1.

Role of MT-MMPs and MMP-2 in pancreatic cancer progression.

Activation of matrix metalloproteinase-2 (MMP-2) by the membrane-type matrix metalloproteinases (MT-MMPs) has been associated with tumor progression. In the present study, we examined the role of MMP-2 and its activators MT1-MMP, MT2-MMP and MT3-MMP in pancreatic tumor cell invasion and the development of the desmoplastic reaction characteristic of pancreatic cancer tissues. Northern blot analyses revealed that transcript levels of MT1-MMP and MT2-MMP, but not MT3-MMP, were enhanced in pancreatic cancer tissues (n = 18) compared with both chronic pancreatitis (n = 9) and healthy pancreas (n = 9). A good correlation was found between MT1-MMP and both MMP-2 expression (p < 0.01) and activity in pancreatic cancer tissues. In addition, expression and activation of MMP-2 were strongly associated with the extent of the desmoplastic reaction in pancreatic cancer tissues. Invasion assays showed a good correlation between MMP-2 expression and activity and the invasive potential of pancreatic cancer cell lines. In cell lines with high levels of MMP-2 expression and activity, the MMP inhibitor Batimastat led to significant reduction of the number of invading cells. Our results suggest that MT1-MMP is involved in the progression of pancreatic cancer via activation of MMP-2. MMP-2 itself plays an important role in tumor cell invasion and appears to be associated with the development of the characteristic desmoplastic reaction in pancreatic cancer.

Propofol hemisuccinate protects neuronal cells from oxidative injury.

Oxidative stress contributes to the neuronal death observed in neurodegenerative disorders and neurotrauma. Some antioxidants for CNS injuries, however, have yet to show mitigating effects in clinical trials, possibly due to the impermeability of antioxidants across the blood-brain barrier (BBB). Propofol (2,6-diisopropylphenol), the active ingredient of a commonly used anesthetic, acts as an antioxidant, but it is insoluble in water. Therefore, we synthesized its water-soluble prodrug, propofol hemisuccinate sodium salt (PHS), and tested for its protective efficacy in neuronal death caused by non-receptor-mediated, oxidative glutamate toxicity. Glutamate induces apoptotic death in rat cortical neurons and the mouse hippocampal cell line HT-22 by blocking cystine uptake and causing the depletion of intracellular glutathione, resulting in the accumulation of reactive oxygen species (ROS). PHS has minimal toxicity and protects both cortical neurons and HT-22 cells from glutamate. The mechanism of protection is attributable to the antioxidative property of PHS because PHS decreases the ROS accumulation caused by glutamate. Furthermore, PHS protects HT-22 cells from oxidative injury induced by homocysteic acid, buthionine sulfoximine, and hydrogen peroxide. For comparison, we also tested alpha-tocopherol succinate (TS) and methylprednisolone succinate (MPS) in the glutamate assay. Although TS is protective against glutamate at lower concentrations than PHS, TS is toxic to HT-22 cells. In contrast, MPS is nontoxic but also nonprotective against glutamate. Taken together, PHS, a water-soluble prodrug of propofol, is a candidate drug to treat CNS injuries owing to its antioxidative properties, low toxicity, and permeability across the BBB.

Aqueous extracts of cigarette smoke promote the oxidation of low density lipoprotein by peroxidases.

Oxidation of low density lipoprotein (LDL) by cigarette smoke has been considered a potential mechanism by which smoking may promote atherosclerosis. We report in this study that cigarette smoke extract (CSE) inhibited copper-induced oxidation of LDL suggesting the presence of antioxidants in CSE. It is currently believed that peroxidases may oxidize LDL in vivo and during such oxidations antioxidants become pro-oxidants. Accordingly, when LDL was oxidized by peroxidase in the presence of CSE there was an increase in the oxidation of LDL. This is the first study suggesting that smoking may promote atherosclerosis by enhancing peroxidase-catalyzed lipid peroxidation.

Outpatient geriatric evaluation and management. Results of a randomized trial.

The effectiveness and efficiency of outpatient geriatric evaluation and management (GEM) was compared with usual outpatient primary care (UPC). One hundred sixty frail elderly outpatients were assigned randomly to GEM or UPC and assessed at baseline and at 8 months on measures of (1) health and functional status, (2) psychosocial well-being, (3) quality of health and social care, (4) use of inpatient and outpatient services, and (5) cost of care. The results indicate that GEM was significantly more effective than UPC in reducing mortality, increasing patient satisfaction, and improving the quality of health and social care. However, it was not effective in reducing health care use or the cost of care.

Rehabilitation of patients with spinal cord disease.

Spinal cord injury and disease have multisystem consequences and many potential medical complications. This article addresses the various medical, psychosocial, and vocational issues associated with spinal cord injury and describes how the patient's lifestyle may be affected. The role of the physician and other rehabilitation professionals in the rehabilitation process is described. In addition, various medical concerns, complications, and available treatment modalities are discussed.

Neoadjuvant chemotherapy in early-stage and locally advanced small bulk squamous cell carcinoma of the oral cavity and oropharynx.

Thirty patients with Stages I, II and III squamous cell carcinoma of the oral cavity and oropharynx (6, 12 and 12 patients, respectively) were entered into a combined modality protocol using preoperative chemotherapy, followed by resection with or without radical neck dissection and radiotherapy. None of the patients received prior treatment and all had good performance status. Primary sites included alveolar ridge (in nine patients), buccal mucosa (in eight), tongue (in six), floor of mouth (in five), and hard palate and tonsillar fossa in one each. Chemotherapy was given as a neoadjuvant debulking procedure using two courses of the Price-Hill regimen (5FU, methotrexate with citrovorum rescue, vincristine, bleomycin, and hydrocortisone) followed in 10 to 14 days by local resection for Stage I-II patients and radical neck dissection plus radiotherapy for Stage III patients. Response to chemotherapy alone was observed in 70% (21 of 30), with 17% (5 of 30) complete responders. Responses were seen in 100% of Stage I, 75% of Stage II, and 50% of Stage III patients. Age greater than 80 years was a poor prognostic indicator. Both men and women responded equally well. Of the 25 patients not entering CR with chemotherapy, a further 75% (11 of 15) did so after local resection and 50% (5 of 10) after local resection, radical neck dissection, and radiotherapy. Overall salvage rate post chemotherapy was 64% (16 of 25). All five patients in CR with chemotherapy alone are alive at a median follow-up time of greater than or equal to 43 months; full survival data are discussed. Toxicity was minimal and did not affect change in treatment course in any patient. These results show that further investigations on the use of neoadjuvant chemotherapy in early-stage and locally advanced squamous cell carcinoma of the oral cavity and oropharynx are indicated.

Idiopathic submandibular abscesses in children.

Idiopathic submandibular abscesses are often observed in young children and the report concerns 31 children treated over a period of 3 years. Their origin is unknown. As all these abscesses were lymph node abscesses in the submandibular region, it is assumed that they are due to minor oral and nasal cavity traumatic lesions secondarily infected. Antibiotic treatment and surgical drainage resulted in quick resolution and recurrences were never observed.

Thalidomide for autoimmune disease.

The therapeutic efficacy of thalidomide in erythema nodosum leprosum suggests that thalidomide might play a useful therapeutic role in other human immune-complex diseases. Thalidomide has shown anti-inflammatory or immunosuppressive actions in several animal models. Current evidence suggests that its rapid activity in ENL may result from suppression of neutrophil chemotaxis and phagocytosis. Scattered anecdotal clinical reports of apparent response to thalidomide in various autoimmune diseases are hardly conclusive, but underline the desirability of appropriate pilot trials of thalidomide in autoimmune diseases, particularly those in which immune complex deposition plays a prominent role. Provided that a contraindication in fertile women is strictly observed, thalidomide therapy appears to be quite safe.

Divalent cation-activated RNA synthesis in toluene-treated Escherichia coli.

Novel RNA polymerase activities (termed type II reaction) can be found in toluene-treated Escherichia coli with Ca2+, Fe2+, or endogenously bound cations, probably Mg2+. These activities are distinguishable from the well characterized DNA-dependent RNA polymerase (type I reaction) by: (i) their divalent cation requirements, i.e., the classical enzyme is activated by exogenously added Mn2+, Mg2+, or CO2+ ions; (ii) their relative resistance to inhibition by actinomycin D, rifampicin, and streptolydigin; (iii) their selective synthesis of low molecular weight RNA; (iv) their sensitivity to inhibition by arabinonucleoside 5'-triphosphates or deoxyribonucleoside 5'-triphosphates; and (v) the strict requirement for ATP in Ca2+ and bound cation-activated reactions. The Ca2+-activated and endogenous RNA polymerase activities are inhibited by orthophosphate. The properties of the type II RNA polymerase(s) are compared with those of polynucleotide phosphorylase, and dnaG gene product, and the RNA polymerase described by Ohasa and Tsugita.

Escherichia coli DNA polymerases II and III: activation by magnesium or by manganous ions.

Escherichia coli DNA polymerases II and III have been extensively studied in vitro when activated with Mg2+. The Mn2+-activated polymerization reactions are considered here, and shown to differ from the Mg2+-activated reactions. The Mn2+-activated DNA polymerase II reaction requires K+ or spermidine, and the effects of monovalent cation and polyamine are additive. In contrast, the Mg2+-activated reaction does not require, but is stimulated by, K+ or spermidine, in a non-additive manner. Under optimal conditions, DNA polymerase II is activated better with Mn2+ than it is with Mg2+, suggesting a physiological role for the Mn2+-activated enzyme. The observed preference for Mn2+ over Mg2+ in reaction kinetics and at high DNA template concentrations suggest that Mg2+ may preferentially activate the associated exonuclease activity. At 29 degrees C, the Mn2+-activated DNA polymerase III reaction is stimulated by K+ and inhibited by ethanol or phosphatidylethanolamine. In contrast, the latter compounds and Triton X-100 increase the initial rate of the Mg2+-activated reaction, whereas K+ inhibits this reaction at all concentrations. The K+ inhibition is reduced at low Mg concentrations when Mn2+ is also present. After stimulating the initial reaction rate, ethanol causes a rapid decrease in the rate of the Mg2+-activated reaction during incubation at 20 degrees C. At 27 degrees C, all surface-active compounds inhibit the Mg2+-activated reaction. Preincubation of the enzyme at 30 degrees C or below with DNA template and divalent cation increases the initial reaction rate, suggesting that formation of an enzyme-divalent cation-DNA template complex occurs as the first step in DNA polymerase III catalysis. The apparent Km at 21 degrees C for gapped calf thymus DNA was 25 muM with Mn2+ and 125 muM with Mg2+ for DNA polymerase III, and 18 muM at 30 degrees C for DNA polymerase II with either Mn2+ or Mg2+. Reactions with poly[d(A-T)] were enhanced by Mn2+ relative to Mg2+, and activity with poly(rA)-poly(dT) was Mn2+ dependent for both enzymes.