Monocyte tissue factor-like activity in post myocardial infarction patients

It is widely recognized that thrombosis is the major event in the evolution of stable vascular disease to unstable ischaemic syndromes including myocardial infarction and stroke. The purpose of this case-control study was to establish clinical and laboratory data on the possible relationship between specific components of the haemostatic system and coronary heart disease. The procoagulant activity (PCA) of peripheral monocytes and polymorphonuclear neutrophils was assessed in 21 males who had suffered a myocardial infarction (MI) and in age-matched controls. In addition, total factor VII activity, fibrinogen, tissue factor pathway inhibitor (TFPI). D-dimers, tissue plasminogen activator (t-PA), plasminogen activator inhibitor (PAI-1), tumour necrosis factor-alpha (TNF-alpha) and full blood counts were measured. Post MI patients had significantly higher monocyte PCA, higher plasma concentrations of TFPI, fibrinogen, t-PA, T/P100 and also higher total white blood cell and neutrophil counts compared to age-matched controls. This elevated procoagulant state in post MI patients could further exacerbate the disease process and increase the risk of subsequent acute ischaemic events.     

Neurologic problems of the lower extremity associated with HIV and AIDS

Lower extremity symptoms are caused by lesions at any level of the neuraxis, from cortex to muscle. HIV affects virtually every level of the nervous system, either directly or indirectly. The presence of pathology at multiple levels and by multiple processes further complicates the bedside diagnosis of a patient with AIDS and neurologic symptoms. Many neuropathies and other conditions that affect the lower extremities can be identified with careful history and physical examination, confirmed with limited testing, and can be treated successfully. Distal symmetric polyneuropathy is the most common lower extremity disorder, but it must be distinguished from similar-appearing neuropathies caused by medications, B12 deficiency, or vasculitis. Diffuse infiltrative lymphocytosis syndrome also causes a painful peripheral neuropathy that must be distinguished from distal symmetric polyneuropathy. Inflammatory demyelinating polyneuropathies are characterized by muscle weakness. They occur in early, asymptomatic HIV infection and respond to plasmapheresis or steroids. Mononeuropathies in patients with CD4 counts more than 200 often resolve on their own. Multiple mononeuropathies, which occur in patients with CD4 counts less than 50, are often associated with cytomegalovirus infection and may follow a rapidly progressive course unless treated promptly and aggressively. Progressive polyradiculopathy occurs late in the course of AIDS, is often caused by cytomegalovirus, is rapidly progressive, and generally is fatal unless recognized and treated promptly. Muscle weakness, myalgia, and fatigue are common in HIV and have multiple causes. Lower extremity spasticity may be caused by treatable etiologies such as spinal cord abscess, tumor, disc compression, B12 deficiency, or ischemia. Gait disturbances are common but nonspecific and may be caused by treatable neurologic disorders at any level of the neuraxis.     

Feedback inhibition of macrophage tumor necrosis factor-alpha production by tristetraprolin

Tumor necrosis factor-alpha (TNF-alpha) is a major mediator of both acute and chronic inflammatory responses in many diseases. Tristetraprolin (TTP), the prototype of a class of Cys-Cys-Cys-His (CCCH) zinc finger proteins, inhibited TNF-alpha production from macrophages by destabilizing its messenger RNA. This effect appeared to result from direct TTP binding to the AU-rich element of the TNF-alpha messenger RNA. TTP is a cytosolic protein in these cells, and its biosynthesis was induced by the same agents that stimulate TNF-alpha production, including TNF-alpha itself. These findings identify TTP as a component of a negative feedback loop that interferes with TNF-alpha production by destabilizing its messenger RNA. This pathway represents a potential target for anti-TNF-alpha therapies.     

osteoprotegerin-deficient mice develop early onset osteoporosis and arterial calcification

Osteoprotegerin (OPG) is a secreted protein that inhibits osteoclast formation. In this study the physiological role of OPG is investigated by generating OPG-deficient mice. Adolescent and adult OPG-/- mice exhibit a decrease in total bone density characterized by severe trabecular and cortical bone porosity, marked thinning of the parietal bones of the skull, and a high incidence of fractures. These findings demonstrate that OPG is a critical regulator of postnatal bone mass. Unexpectedly, OPG-deficient mice also exhibit medial calcification of the aorta and renal arteries, suggesting that regulation of OPG, its signaling pathway, or its ligand(s) may play a role in the long observed association between osteoporosis and vascular calcification.     

Cloning of two isoforms of mouse DNA helicase Q1/RecQL cDNA; alpha form is expressed ubiquitously and beta form specifically in the testis

We cloned cDNAs encoding mouse homologues for the human DNA helicase Q1/RecQL (human helicase Q1) which has homology with the Escherichia coli RecQ protein and found that they encode two isoforms. The two isoforms are identical over the entire sequence except for the carboxyl terminal sequence spanning less than 30 amino acids. One of the two isoforms, alpha, contains a sequence, KKRK, in the carboxyl terminus, which is also contained in human helicase Q1 and was confirmed to function as the nuclear localization signal. The other form, beta, does not contain such a sequence. Expression of mouse helicase Q1 mRNA is extremely and relatively high in the testis and the thymus, respectively. RT-PCR analysis revealed that helicase Q1alpha was expressed in all tissues tested and the beta form was expressed only in the testis. A survey of expression of Q1alpha and Q1beta mRNA in the testis after birth revealed that Q1alpha mRNA is expressed in all testes of mice aged from 7 days to 8 weeks, and the expression of Q1beta mRNA begins 14 days after birth, corresponding to the appearance of cells in the pachytene stage.     

Intermediate-grade lymphomas treated with cyclophosphamide-doxorubicin- vincristine-prednisone-bleomycin alternated with cyclophosphamide-methotrexate-etoposide-dexamethasone. Application of prognostic models to data analysis

BACKGROUND: Numerous treatment strategies have been tried with the aim of improving results for patients with intermediate-grade lymphomas (IGL) over those achieved with cyclophosphamide, doxorubicin, vincristine, prednisone, and bleomycin (CHOP-Bleo), and numerous prognostic models have been developed to identify and separate risk groups. This study reports on a new protocol for Ann Arbor Stages II-IV IGL that consists of CHOP-Bleo alternated with a new regimen of cyclophosphamide, methotrexate, etoposide, and dexamethasone (CMED) and radiation therapy and demonstrates the usefulness of prognostic models for identifying risk groups and comparing treatment programs. METHODS: One hundred seventy patients with Ann Arbor Stages II-IV IGL were treated with alternating cycles of CHOP-Bleo and CMED for a total of 12 cycles. Involved field radiation therapy was interspersed with courses of chemotherapy for patients with Stage II and Stage III disease. Results were analyzed and compared with those of the authors' previous study of CHOP-Bleo and radiation therapy using the Ann Arbor staging system, their earlier prognostic model, and the recently published International Index. RESULTS: A complete remission occurred in 78% of the patients. The overall 5-year survival rate was 67%. Survival was better for patients with Ann Arbor Stage II disease (80%) than for those with Stage III or Stage IV (67% and 58%, respectively). High tumor burden, above-normal levels of serum lactic dehydrogenase, serum beta 2-microglobulin, and Ann Arbor Stage IV disease were adverse factors. The International Index and the authors' earlier prognostic model separated four prognostic groups. CHOP-Bleo/CMED was generally well tolerated. Neutropenic fever was the major complication that occurred in 25 patients during treatment. Six of these patients died of sepsis. CONCLUSIONS: This study demonstrated that CHOP-Bleo/CMED is a well-tolerated regimen that produced better results than those reported for a former study that used CHOP-Bleo alone. Further, results for CHOP-Bleo/CMED compared favorably with those of other second- and third-generation regimens. The study also validated the usefulness of prognostic models and, in particular, the new International Index for identifying risk groups.     

Proteolysis of extracellular matrix by invadopodia facilitates human breast cancer cell invasion and is mediated by matrix metalloproteinases

Breast cancer cell lines vary in invasive behavior and one highly invasive cell line (MDA-MB-231) proteolytically degrades extracellular matrix with invadopodia (Thompson et al. 1992, J Cell Physiol, 150, 534-44; Chen et al 1994, Breast Cancer Res Treat, 31, 217-26). Invadopodial proteolysis of extracellular matrix is thought to be necessary for invasion; however, this has not been demonstrated directly. To obtain such evidence, normal (HBL-100) and malignant (MCF-7, MDA-MB-231) breast cells were evaluated for invadopodial proteolysis of extracellular matrix and invasive behavior. We report that invadopodial proteolysis of immobilized fibronectin is positively correlated with invasion of cells into type I collagen gels. Moreover, reducing the proteolytic activity of invadopodia with the metalloproteinase inhibitor, batimastat (BB-94), also decreases invasion indicating that breast cancer cell invasion is dependent upon proteolytically active invadopodia.