Biomedical subjects

Adam Mor

Publications and source records attributed to Adam Mor.

10 recordsLinked to original sources

PubMed2006

PKC regulates a farnesyl-electrostatic switch on K-Ras that promotes its association with Bcl-XL on mitochondria and induces apoptosis.

K-Ras associates with the plasma membrane (PM) through farnesylation that functions in conjunction with an adjacent polybasic sequence. We show that phosphorylation by protein kinase C (PKC) of S181 within the polybasic region promotes rapid dissociation of K-Ras from the PM and association with intracellular membranes, including the outer membrane of mitochondria where phospho-K-Ras interacts with Bcl-XL. PKC agonists promote apoptosis of cells transformed with oncogenic K-Ras in a S181-dependent manner. K-Ras with a phosphomimetic residue at position 181 induces apoptosis via a pathway that requires Bcl-XL. The PKC agonist bryostatin-1 inhibited the growth in vitro and in vivo of cells transformed with oncogenic K-Ras in a S181-dependent fashion. These data demonstrate that the location and function of K-Ras are regulated directly by PKC and suggest an approach to therapy of K-Ras-dependent tumors with agents that stimulate phosphorylation of S181.

Amino Acid Sequence↗

PubMed2006

Syphilis mimicking Reiter's syndrome in an HIV-positive patient.

A 38-year-old man with HIV infection presented with panuveitis, urethritis, and a papulosquamous eruption on his palms and soles. Careful physical and laboratory examination led to the diagnosis of syphilitic keratoderma, uveitis, and balanitis. The patient was successfully treated with penicillin and prednisone therapy. Because the initial presentation was difficult to distinguish from the symptoms of Reiter's syndrome, a high degree of clinical suspicion was required to accurately diagnose syphilis, a curable and potentially fatal disease.

Adult↗

PubMed2006

Relapsing oligoarticular septic arthritis during etanercept treatment of rheumatoid arthritis.

Septic arthritis is a commonly reported complication of rheumatoid arthritis (RA). Tumor necrosis factor alpha (TNF-alpha) plays an important role in host defense against infection. Inhibition of its activity could therefore be anticipated to augment the risk of infection. Both opportunistic and bacterial infections have been described in patients with RA treated with anti-TNF-alpha therapy. We describe a patient who experienced 2 episodes of septic arthritis. Both occurred while the patient was on etanercept. Recurrence developed despite prolonged parenteral antibiotic. To our knowledge, this is the first report of relapsing oligoarticular methicillin-sensitive Staphylococcus aureus septic arthritis despite prolonged antibiotic treatment in a patient receiving etanercept therapy. Our case underscores the advisability of discontinuing TNF-alpha blockade in patients with septic arthritis during prolonged antimicrobial therapy.

Aged↗

PubMed2006

Compartmentalized Ras/MAPK signaling.

Signal transduction down the Ras/MAPK pathway, including that critical to T cell activation, proliferation, and differentiation, has been generally considered to occur at the plasma membrane. It is now clear that the plasma membrane does not represent the only platform for Ras/MAPK signaling. Moreover, the plasma membrane itself is no longer considered a uniform structure but rather a patchwork of microdomains that can compartmentalize signaling. Signaling on internal membranes was first recognized on endosomes. Genetically encoded fluorescent probes for signaling events such as GTP/GDP exchange on Ras have revealed signaling on a variety of intracellular membranes, including the Golgi apparatus. In fibroblasts, Ras is activated on the plasma membrane and Golgi with distinct kinetics. The pathway by which Golgi-associated Ras becomes activated involves PLCgamma and RasGRP1 and may also require retrograde trafficking of Ras from the plasma membrane to the Golgi as a consequence of depalmitoylation. Thus, the Ras/MAPK pathway represents a clear example of compartmentalized signaling.

Animals↗

PubMed2005

The fibroblast-like synovial cell in rheumatoid arthritis: a key player in inflammation and joint destruction.

Although multiple cell types are present in the rheumatoid joint, the fibroblast-like synovial cell (FLS) is among the most prominent. It is now appreciated that the FLS is not only space-filling, but is directly responsible for cartilage destruction, and also drives both inflammation and autoimmunity. In this article, we consider the normal role of the FLS in healthy joints, and review evidence that implicates the FLS as a central player in the propagation of rheumatoid arthritis.

Animals↗

PubMed2005

Evaluation of disease severity in familial Mediterranean fever.

OBJECTIVE: To establish a new, objective, statistically based severity score for familial Mediterranean fever (FMF). METHODS: One hundred consecutive FMF patients were evaluated independently by 2 FMF experts for severity of their disease and were assigned to 1 of 3 severity levels: mild, intermediate, or severe. Nine candidate criteria, reflecting objective suffering and disability, were analyzed to determine their weight for patient placement in the 3 predefined severity groups. RESULTS: Candidate criteria best differentiating between the 3 patient categories were the frequency of attacks, the number of sites affected during an attack and during the course of the disease, and the duration of the attacks. These criteria were applied in a classification-tree model to establish a new FMF-severity score (F-SS). The first set of F-SS (F-SS-1) was highly sensitive and specific. Integrating F-SS-1 with clinical parameters strongly associated with disease severity resulted in a simplified score, the second set of F-SS (F-SS-2). CONCLUSIONS: New, useful, objective, and valid severity scores were established and found to distinguish between patients with mild, intermediate, and severe diseases with high sensitivity and specificity. RELEVANCE: The F-SS established may be important for treatment decisions, prognosis evaluation, and comparative analysis of patient populations.

Adult↗

PubMed2005

Proliferative lupus nephritis and leukocytoclastic vasculitis during treatment with etanercept.

Tumor necrosis factor-alpha (TNF-alpha) is a proinflammatory cytokine. Agents that neutralize TNF-alpha are effective in the treatment of disorders such as rheumatoid arthritis, juvenile rheumatoid arthritis (JRA), spondyloarthropathies, and inflammatory bowel disease. TNF-alpha antagonist therapy has been associated with the development of antinuclear antibodies (ANA) and double-stranded DNA (dsDNA) antibodies, as well as the infrequent development of systemic lupus erythematosus (SLE)-like disease. We describe the first case of biopsy-confirmed proliferative lupus nephritis and leukocytoclastic vasculitis in a patient treated with etanercept for JRA.

Adult↗

PubMed2005

Arthritis as the sole episodic manifestation of familial Mediterranean fever.

OBJECTIVE: To clinically and genetically characterize patients with familial Mediterranean fever (FMF) in whom arthritis constitutes the only manifestation, and to establish the most important features distinguishing FMF arthritis in such a setting from other forms of mono/oligo arthritides. METHODS: The study population comprised 14 patients with episodes of arthritis as the only manifestation of FMF who nevertheless fulfilled the diagnostic criteria for FMF. The control group consisted of 28 patients with episodic mono/oligo arthritis of different disease entities (palindromic, reactive, inflammatory bowel disease, Reiter's, seronegative spondyloarthropathy, chronic juvenile, Behcet's, and gouty arthritis) who presented to the rheumatology clinic during the study period. Patients in both groups underwent clinical evaluation and donated blood for FMF gene analysis. RESULTS: The study and control groups shared similar age and sex distribution and experienced the monoarthritic attacks at similar sites, usually the knee and ankle joint. The 2 groups differed significantly in features of arthritis (which were febrile and of short duration in FMF), family history of FMF, mutation analysis, and response to colchicine. These differences allowed the defining of a rule, which readily distinguishes FMF arthritis from other forms of episodic mono/oligo arthritis. CONCLUSION: The clinical, ethnic, and genetic features of recurrent monoarthritis of FMF are specific and may separate FMF from other entities with mono/oligo arthritis.

Adolescent↗

PubMed2003

Abdominal and digestive system associations of familial Mediterranean fever.

Familial Mediterranean fever (FMF) is a hereditary episodic febrile syndrome that is expressed by acute spells of fever, painful manifestations in the abdomen, chest and joints, and slow development of nephropathic amyloidosis. Despite the recent cloning of the FMF gene (MEFV) and the identification of about 40 disease-related mutations, the diagnosis is still clinically dependent, and the pathogenesis and most of the clinical heterogeneity remain to be explained. Because episodic abdominal pain affects 95% of FMF patients, most of them are seen by gastroenterologists and undergo complete or partial abdominal imaging before the diagnosis is made. Focusing on recent advances in FMF, this article reviews both common and infrequent manifestations that a gastroenterologist may encounter during workups of FMF patients. These include episodic abdominal pain, paralytic or mechanical ileus, constipation, diarrhea, ascites, malabsorption, bowel infarction, and bleeding, arising directly from FMF or secondary to FMF common associations such as amyloidosis, vasculitides, inflammatory bowel disease, irritable bowel syndrome, or colchicine side effects. This article will help the gastroenterologist to cope with most clinical situations related to the abdominal and alimentary tract in patients with FMF.

Abdominal Pain↗

PubMed2003

Analysis of the three most common MEFV mutations in 412 patients with familial Mediterranean fever.

BACKGROUND: Familial Mediterranean fever is an autosomal recessive disease characterized by recurrent attacks of fever and serositis. The disease is caused by mutations in the MEFV gene, presumed to act as a down-regulator of inflammation within the polymorphonuclear cells. OBJECTIVES: To present the results of 412 FMF patients genotyped for three MEFV mutations, M694V, V726A and E148Q. RESULTS: The most frequent mutation, M694V, was detected in 47% of the carrier chromosomes. This mutation, especially common among North African Jewish FMF patients, was not found in any of the Ashkenazi (East European origin) patients. Overall, one of the three mutations was detected in 70% of the carrier chromosomes. M694V/M694V was the most common genotype (27%), followed by M694V/V726A (16%). The full genotype could be assessed in 57% of the patients, and one disease-causing mutation in an additional 26%. Only one patient with the E148Q/E148Q genotype was detected despite a high carrier rate for this mutation in the Jewish population, a finding consistent with a low penetrance of this genotype. The M694V/M694V genotype was observed in 15 patients with amyloidosis compared to 4 amyloidosis patients with other genotypes (P < 0.0001). CONCLUSIONS: Because of low penetrance and as yet other undetermined reasons, mutation analysis of the most common MEFV mutations supports a clinical diagnosis in only about 60% of patients with definite FMF.

Amyloidosis↗