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Platelets survey blood vessels, searching for endothelial damage and preventing loss of vascular integrity. However, there are circumstances where vascular permeability increases, suggesting that platelets sometimes fail to fulfill their expected function. Human inflammatory arthritis is associated with tissue edema attributed to enhanced permeability of the synovial microvasculature. Murine studies have suggested that such vascular leak facilitates entry of autoantibodies and may thereby promote joint inflammation. Whereas platelets typically help to promote microvascular integrity, we examined the role of platelets in synovial vascular permeability in murine experimental arthritis. Using an in vivo model of autoimmune arthritis, we confirmed the presence of endothelial gaps in inflamed synovium. Surprisingly, permeability in the inflamed joints was abrogated if the platelets were absent. This effect was mediated by platelet serotonin accumulated via the serotonin transporter and could be antagonized using serotonin-specific reuptake inhibitor antidepressants. As opposed to the conventional role of platelets to microvascular leakage, this demonstration that platelets are capable of amplifying and maintaining permeability adds to the rapidly growing list of unexpected functions for platelets.

Introduction: The CCR5 chemokine receptor occurs in a wild-type (wt) and a nonfunctional deleted form (Δ32). Reports suggested that Chlamydia-induced reproductive tract pathology is attenuated in women bearing Δ32. The authors asked whether the mutation affects synovial prevalence and burden of Chlamydia trachomatis., Methods: Polymerase chain reaction (PCR) defined CCR5 genotype in synovial tissue DNA from 218 individuals: 21 controls, 110 with reactive arthritis (ReA), 83 with undifferentiated oligoarthritis (UO), 4 with osteoarthritis (OA). Disease durations were 0.5 to 21 years. Additional PCR assays defined the presence of C trachomatis DNA. Bacterial load was assessed by real-time PCR in selected samples., Results: Five controls were wt/Δ32, 16 were wt/wt; 2 of 21 controls (both wt/wt) were PCR positive for C trachomatis. Eighty-five (44%) patients with arthritis were PCR positive for C trachomatis (69 ReA and 16 UO). For patients with ReA, 14 (13%) had wt/Δ32, 10 (71%) of whom were PCR positive. Nineteen patients with UO (23%) were wt/Δ32, with 1 (1%) PCR positive. No differences existed for gender or other factors. One patient with OA had wt/Δ32. In ReA and UO samples, wt/Δ32 heterozygotes had a 5- to 10-fold higher bacterial burden than did wt/wt patients (P = 0.03), regardless of diagnosis., Conclusion: These results indicate that the wt/wt genotype is associated with attenuated synovial bacterial load compared with loads in wt/Δ32 patients. Although no alleles other than Δ32 were assessed, our data suggest that this allele provides little/no protection from ReA in patients infected with Chlamydia- but it may provide some protection in patients with UO. The basis of this possible differential effect of CCR5 genotype is under study.

Patients with parathyroid disease can have important musculoskeletal problems.Hypoparathyroidism can cause subcutaneous calcifications, tetany, muscle cramps,and paresthesias, but also myopathies and an ankylosing spondylitis-like back disease. Hypoparathyroidism can occur in SLE caused by antiparathyroid antibodies.Patients with hyperparathyroidism can develop bone disease with cysts, erosions,and deformities. They can also develop pseudogout, gout, myopathies, and tendon ruptures., (Copyright © 2010 Elsevier Inc. All rights reserved.)

The management of gout can be subdivided into four phases. Asymptomatic hyperuricaemia represents the basic underlying metabolic abnormality that can lead to gout. Studies are evaluating whether interventions may be indicated in some cases. Diagnostic criteria for gout and acute flares are still not well defined unless urate crystals are found. Acute attacks of gout are treated with anti-inflammatory measures and the agent of choice is often determined by attack stage, severity and comorbidities that may contra-indicate one or more agents. After attacks subside, there are asymptomatic periods during which decisions must be made about when and how to start urate-lowering measures. If hyperuricaemia persists, there is generally persistence of urate crystals in the joint. Anti-inflammatory prophylaxis is needed when urate-lowering therapy is started. Lifestyle measures should be addressed. If chronic tophaceous gout is diagnosed, urate lowering should be started without delay. New agents are under development that may help with difficult cases.

Newer approaches to the treatment of gout have included modifications and further attention to aspects of current therapies, and development of interesting new therapies. Colchicine prophylaxis appears to be needed longer than previously recognized after introduction of a urate-lowering agent. Diet has received attention, though most dietary effects are small. New agents under investigation include pegylated formulations of uricase and a new potent xanthine oxidase inhibitor, febuxostat. Some cardiovascular drugs have been shown to be uricosuric.

Inflammatory arthropathies are characterized by major changes in gene expression, which-ultimately-result from differential activities of intracellular signaling pathways and their associated inducible transcription factors. The nuclear factor of activated T cells' (NFAT) family of transcription factors plays diverse roles in a variety of processes in the immune system and other tissues. Preliminary evidence has recently emerged implicating NFAT family members directly in the pathogenesis of inflammatory arthropathies. Specific anti-NFAT drug therapy may add to the pharmacologic armamentarium against rheumatoid arthritis, other inflammatory arthropathies, and related autoimmune disorders.

The Chlamydia trachomatis genome encodes glycolysis and pentose phosphate pathway enzymes, two ATP/ADP exchange proteins, and other energy transduction-related components. We asked if and when chlamydial genes specifying products related to energy transduction are expressed during active vs. persistent infection in in vitro models and in synovia from Chlamydia-associated arthritis patients. Hep-2 cells infected with K serovar were harvested from 0-48 h post-infection (active infection). Human monocytes identically infected were harvested at 1, 2, 3, 5 days post-infection (persistent). RNA from each preparation and from synovial samples PCR-positive/-negative for Chlamydia DNA was subjected to RT-PCR targeting (a) chlamydial primary rRNA transcripts and adt1 mRNA, (b) chlamydial mRNA encoding enzymes of the glycolysis (pyk, gap, pgk) and pentose phosphate (gnd, tal) pathways, the TCA cycle (mdhC, fumC), electron transport system (cydA, cydB), and sigma factors (rpoD, rpsD, rpoN). Primary rRNA transcripts and adt1 mRNA were present in each infected preparation and patient sample; controls were negative for chlamydial RNA. In infected Hep-2 cells, all energy transduction-related genes were expressed by approximately 11 h post-infection. In monocytes, pyk, gap, pgk, gnd, tal, cydA mRNA were present in 1-2-day-infected cells but absent at 3 days and after; cydB, mdhC, fumC were expressed through 5 days post-infection. RT-PCR targeting mRNA from sigma factor genes indicated that lack of these gene products cannot explain selective transcriptional down-regulation during persistence. Analyses of RNA from synovial tissues mirrored those from the monocyte system. These data suggest that in the first phase of active chlamydial infection, ADP/ATP exchange provides energy required for metabolism; in active growth, glycolysis supplements host ATP. In persistence host, rather than bacterially produced, ATP is the primary energy source. Metabolic rate in persistent C. trachomatis is lower than in actively growing cells, as judged from assays for relative chlamydial primary rRNA transcript levels in persistent vs. actively growing cells.

In past years, consensus has been reached on the assessment of rheumatoid arthritis in clinical trials. Next to a core set of disease activity variables, response criteria have been developed and validated. These criteria are, however, of limited value in daily clinical practice. In this situation, emphasis should be paid to accurate measurement of disease activity on a continuous scale using the lowest possible number of core set variables. Different studies have shown that the DAS28 is a valuable instrument for this purpose. Many factors have been identified to possess a prognostic value; however, the IgM rheumatoid factor is still the only one which is of any importance in daily clinical practice., (Copyright 2001 Harcourt Publishers Ltd.)

Yoga is an ancient tradition that has been westernized and often practiced for its proposed health benefits. Traditional texts describe its benefits for many types of arthritis. Two limited studies of yoga in osteoarthritis of the hands and carpal tunnel syndrome show greater improvement in pain than in control groups. Yoga uses stretching and improves strength so that it theoretically should be beneficial for some musculoskeletal problems. Yoga merits further study into its cellular and physiologic effects.

Concepts about reactive arthritis are changing and must embrace consideration of the fact that bacteria or their products are present in the joint, not just at the portal of entry in the gastrointestinal (GI) or genitourinary (GU) tracts. With chlamydia-associated disease, atypical elementary bodies can be seen in synovium by electron microscopy, and nucleic acids, including RNA, can be found. It is not yet clear if bacterial nucleic acids are present in postenteric reactive arthritis and whether disease courses are predictably different after GI or GU infection. How bacteria are disseminated to joints and local factors, including cytokines that influence their persistence, are under study. Treatment with antibiotics may help some chlamydia-associated reactive arthritis but is not invariably effective.

It is difficult to quantitate cytokine mRNA profiles in small human tissue specimens obtained by a needle biopsy, even using standard RT-PCR methods, because the amount of mRNA in the specimens is very small. To address this problem, we developed highly sensitive, quantitative, nested RT-PCR techniques to evaluate the expression of multiple cytokine mRNAs in synovial specimens obtained by needle biopsy. To reduce effects of variation of initial RNA concentrations, cDNA from each target RNA sample was normalized, using a simplified competitive PCR method, to the levels of beta-actin cDNA. The first and the second (nested) PCR were performed in the same tube to prevent contamination. The number of PCR-product bands, evident on polyacrylamide gel electrophoresis, was used to quantitate the relative amounts of target cDNA. Using our methods, it was possible to evaluate, in a single synovial tissue specimen obtained by needle biopsy, the relative amounts of mRNAs for 10 cytokines (TNF-alpha, IL-1 beta, IL-2, IL-4, IL-6, IL-10, IL-12 p40, IL-13, IL-15, IFN-gamma) and CD3 delta chain. Our methods are particularly valuable if there are multiple target mRNAs, numerous samples, or if the amounts of mRNAs are limited. The methods are applicable to a wide variety of tissues and target mRNAs.

The authors have shown that protein antigens, RNA, and DNA from Chlamydia trachomatis are present in synovial tissues of patients with Reiter's syndrome (RS). However, those studies gave no insight into the host cell type involved or the precise tissue location of the bacteria. To address such issues, the authors developed an in situ hybridization system to detect chlamydia, and they used that system to examine synovial biopsies from a patient with RS and a patient without RS. The in situ system uses a previously described digoxigenin-labeled DNA probe that hybridizes with chlamydial 16S rRNA sequences in paraformaldehyde-fixed samples. Control studies with chlamydia-infected and uninfected HeLa cells confirmed that the in situ system is as sensitive as is direct fluorescence cytology for detection of the organism. Morphology of host and chlamydia cells is preserved after hybridization. Studies using synovial tissue from an osteoarthritis patient produced no in situ hybridization signal, but similar hybridization to tissue from a culture-/direct fluorescence cytology- negative RS patient had a strong intracellular signal for chlamydia within a subsynovial cell layer. These in situ hybridization results confirm the extensive presence of chlamydia in synovia and extend the authors' earlier observation that chlamydia RNA is present in the synovia of patients with RS. The data also confirm their electron microscopy studies, indicating that chlamydia are intracellular in synovial tissue, and they further show that infected host cells are located beneath the synovial lining.

We have performed a retrospective analysis of the clinical, morphologic, and cytogenetic findings in 26 patients diagnosed between January 1969 and September 1991 with acute erythroblastic leukemia de novo (EL or AML-M6). Clonal chromosomal abnormalities were found in 20 (77%) patients (95% confidence interval [CI], 61% to 93%). Loss of all or part of the long arm (q) of chromosomes 5 and/or 7 was observed in 17 (65%) patients (95% CI, 47% to 83%). In addition, the karyotypes were often complex, with multiple abnormalities and subclones. Among the remaining nine patients, six had a normal karyotype and one each had trisomy 8, t(3;3), or t(3;5). The overall frequency of abnormalities of chromosomes 5 and/or 7 observed in our M6 patients is similar to that observed in our patients with therapy-related acute myeloid leukemia (t-AML; 99 of 129 patients, 77%), but substantially higher than that noted in our other patients with AML de novo (French-American-British [FAB] subtypes M1-M5: 52 of 334 patients, 16%). Our M6 patients with abnormalities of chromosomes 5 and/or 7 were older and had a shorter median survival (16 v 77 weeks [P = .005]) than did the M6 patients without these abnormalities. We found no correlation between morphologic features and either cytogenetic abnormalities or clinical outcome. Of note was the finding that the percentage of myeloblasts, which may account for only a small fraction of the total marrow elements when the revised FAB criteria are applied, had no bearing on prognosis. We conclude that acute erythroblastic leukemia, when defined by morphologic criteria, consists of two distinctive subgroups: one group tends to be older, has complex cytogenetic abnormalities, especially of chromosomes 5 and/or 7, and shares biologic and clinical features with t-AML; the other group, with simple or no detectable cytogenetic abnormalities, has a more favorable prognosis when treated with intensive chemotherapy.

The etiology of RS is not clear, but there is a strong correlation with infectious episodes and some genetic factor(s). Chlamydia have emerged as the most common pathogen associated with RS. We have presented evidence that chlamydia or its antigens may be present in the synovium and may be important in the pathogenesis of RS. The possibility of latent chlamydial infection has also been discussed. Although previous attempts to treat RS with antibiotics were not encouraging, recent reports suggest some favorable effects from antibiotic therapy. There is still a need to further assess the state of the infectious agent and to consider new, more effective regimens.

Both clinical and epidemiological data suggest that inapparent infection by Chlamydia trachomatis occurs in humans. To confirm and study such infections, we developed a hybridization screening system directed toward chlamydial ribosomal RNA (rRNA). Six restriction endonuclease fragments derived from the cloned rrnA operon of chlamydial serovar L2(434) were tested as hybridization screening probes, but only one fragment encoding the 5' portion of the 16s rRNA gene plus some upstream flanking sequence was both sensitive and highly specific in such experiments. In Northern slot blot assays, hybridization analyses with this fragment as probe routinely detected one picogram or less of chlamydial RNA when that RNA was bound to membranes alone or as part of a mixture with a vast excess of mammalian RNA. The probe did not hybridize to RNA from mammalian and relevant bacterial sources but did hybridize to rRNA from B (ocular) and E (genital) serovars of C. trachomatis. Experiments using RNA from conjunctival biopsies and standard conjunctival swab samples from cynomolgus monkeys showed that the probe reliably distinguishes between known chlamydia-infected and uninfected samples. This suggests that it may be useful for clinical screening. Characterization assays for the RNA-directed probe screening system in this monkey model of trachoma provide initial molecular evidence that ocular chlamydial infection may persist longer than previously thought, based solely on direct fluorescence antibody assay (DFA) and culture analyses.

Quantitative and qualitative electron microscopic studies were performed on the mitochondria of leukemic lymphoblasts in 6 patients with acute lymphoblastic leukemia. Similar studies were performed on lymphoblasts from lymph nodes obtained from 10 surgical patients without nodal diseases. Significant quantitative differences between normal and leukemic mitochondria were not observed except for a difference in mitochondrial area per cell (P less than 0.05). This was not significant lacking, qualitative diffecrences were observed. These abnormalities included rare giant mitochondria, disrupted mitochondria with virus-like particles, smaller granules in greater abundance, mitochondrial DNA, and contact between the mitochondrion and nucleus during interphase. Fifty-three percent of the leukemic lymphoblasts contained polyribosomes, as compared to 25% of the normal lymphoblasts. The cells with the polyribosomes contained the giant mitochondria. The leukemic lymphoblasts had an appearance similar to transformed lymphocytes resulting from an immunologic stimulus. This suggests that acute lymphoblastic leukemia may be a disease which is associated with an immunologic response. From the available ultrastructural and biochemical data, it would seem that the leukemic lymphoblast is a product of an abnormal metabolism which affects its ability to differentiate. These ultrastructural findings seem to indicate the need for biochemical investigation of leukemic mitochondria. (Am J Pathol 78:49-58, 1975

Hand mirror cells are a morphological configuration that are seen in immunologically stimulated lymphocytes and can be induced by antigen--antibody complexes. Therefore, the bone marrow and peripheral blood plasma of two patients with acute lymphoblastic leukemia--hand mirror variant were evaluated for the presence of antigen--antibody complexes. Both patients had antigen--antibody complexes in the bone marrow plasma and not in the peripheral blood plasma as determined by double counter-current immunoelectrophoresis. The antigen moiety of these complexes appears immunologically related to components of the baboon endogenous virus (BaEV), and the antibody moiety also appears related to structural components of the BaEV. Bone marrow plasmas from patients without leukemia were evaluated for the presence of antigen--antibody complexes and found to be negative. The antigen--antibody complexes may account for the presence of hand mirror cells in the bone marrow of patients with acute lymphoblastic leukemia--hand mirror variant.

It has been suggested that streptococcal cell wall-induced arthritis in LEW/N rats resembles a localized neoplasm consisting of, in part, a proliferative and invasive population of fibroblast-like synoviocytes. To further pursue this concept, the synoviocytes from diseased rats were characterized in situ and in vitro for various parameters of "transformation." The spindle-shaped synoviocytes were found throughout the synovium and were the predominant cell type at sites of invasion of bone and cartilage by synovium. They stained intensely for vimentin, a microfilament prominently expressed in immature and transformed mesenchymal cells. They stained variably for Ia antigens and did not exhibit T cell surface antigens nor did they stain with histochemical stains characteristic of monocytes or granulocytes. Electron microscopy confirmed their fibroblastlike morphology and suggested high grade metabolic activity. In primary culture, the abnormal synoviocytes were adherent, grew rapidly and did not contact inhibit. Moreover, they grew under anchorage-independent conditions. These abnormal growth characteristics were inhibited by all-trans retinoic acid. Finally, explants of the arthritic synovium formed short-lived tumorlike nodules in athymic nude mice. These observations, considered in the context of other data, support the concept that the pathologic process represents a thymic-dependent, nonmalignant, locally invasive inflammatory neoplasm.

Terminal-deoxynucleotidyl transferase (TdT) bone marrow determinations were performed on 67 patients with leukemia using the indirect immunofluorescence technique. A total of 103 smears were evaluated on 32 patients with acute lymphoblastic leukemia. With some exceptions, TdT levels were elevated at onset, declined during induction except in resistant cases, decreased during remission on chemotherapy, showed slight elevation during remission off chemotherapy, and rose during relapse in those cases previously positive. The most important finding was that patients in remission may have elevated TdT levels. Those were usually less than 10%. A total of 124 bone marrow smears were evaluated on 29 patients with acute myeloid leukemia. In general, values in all categories were below 1%, with a few elevated between 1% to 10%. Six patients with chronic myelogenous leukemia in blast crisis had 13 bone marrow smears evaluated. Five were in myeloblastic crisis and had values of less than 1%; 1 was lymphoblastic which had 50% positive cells at onset. In our experience, TdT determinations are of value in lymphoblastic leukemia in diagnosis, in predicting response to therapy, and in detecting early relapse.

The identification of a morphologically unique lymphocyte in the peripheral blood of patients with infectious mononucleosis (IM) led to additional studies. Examination of Wright-stained smears of EDTA anticoagulated blood obtained from 25 patients with IM at presentation revealed significantly increased (p less than 0.0001) percentages of hand-mirror lymphocytes (HML) (mean 9.2%) compared with normal controls (mean 2.7%) or controls with nonspecific viral syndromes (mean 2.2%). Follow-up blood samples obtained on 10 of these patients demonstrated a marked increase in the HML count (mean 12.1%) that coincided with the onset of recovery. E-rosette separation of Ficoll-Hypaque-derived peripheral blood lymphocytes from 5 patients with early recovery IM showed the HML to be present almost exclusively in the T-cell population, representing about 25% of the T cells. Identical procedures on 5 controls showed less than 5% HML in the T-cell sample. Cytochemistries supported a T-cell derivation for HML. Electron microscopic examination of HML in IM demonstrated that these cells have unique ultrastructural features that may be related to functions of cellular attachment and cytotoxicity.

Detailed study of four patients with BD, four controls with recurrent aphthous stomatitis, and 12 healthy controls has demonstrated markedly decreased levels of salivary SC in both its free and bound forms, and normal total protein concentration in BD salivas. In two BD patients, SC deficiency was also found in jejunal fluids. Depressed in vitro response of blood T cells to mitogens was also noted in BD. Levels of IgA in serum were normal, as well as total numbers of T cells and IgA-carrying B cells in blood. A fluid phase abnormality of the fibrinolytic system as tested by the clot lysis assay was demonstrated in the blood from BD patients. Studies of BD SF and synovial membrane by light and electron microscopy showed inclusions composed of degenerated neutrophils inside monocytes. Abnormalities of host defense mechanisms at the mucous membrane level due to SC deficiency, together with a systemic T cell functional defect and fibrinolytic abnormality, could be important mechanisms in the pathogenesis of recurrent mucosal ulcers and thrombosis in BD.

Pathologic examinations of joint fluid and articular tissues can be valuable in diagnosis and evaluation of pathogenesis of crystal-associated arthropathies provided that careful attention is paid to processing of tissues. Urates, calcium pyrophosphate, and apatite-like crystals are most common in human lesions and are most widely studied.

Patients with rheumatoid arthritis were found to have low plasma pyridoxal phosphate. Treatment with 50-150 mg/day of pyridoxine hydrochloride for 3 months caused a rise in pyridoxal phosphate in most cases to more than 3 times pretreatment levels. There was, however, no improvement in the clinical aspects of rheumatoid arthritis.

Quantitative and qualitative electron microscopic studies were performed on the mitochondria of leukemic myeloblasts in 3 patients with myeloblastic leukemia and in 3 patients with myelomonoblastic leukemia. In addition, to confirm the presence of virus-like particles within mitochondria and better understand the interaction between the virus and mitochondrion, a rat embryo tissue culture infected with MSV-MLV (Moloney sarcoma virus-Moloney leukemia virus) was selected for detailed electron microscopic examination. Significant quantitative differences between normal and leukemic human mitochondria were not observed. However, qualitative abnormalities were found in the human leukemic mitochondria and in the tissue culture material. These abnormalities included variable forms of the leukemic mitochondria (twisted, tear-drop and irregular shapes), fewer cristae, disrupted mitochondria with virus-like particles, smaller granules in greater abundance, mitochondrial DNA, and contact between the mitochondrion and the nucleus. The tissue culture material revealed similar changes, but showed more virus particles which were located outside the cells, in intracytoplasmic sacs and within the mitochondria. In addition two striking features were observed in the tissue culture material not seen in the human material: a) Budding from the outer mitochondrial membrane into the mitochondrial matrix and b) virus particles attached to the cristae. Since mitochondria are important organelles in the glycolytic-oxidative phosphorylation pathways, perhaps all of us engaged in cancer research should take a closer look at the Warburg effect and carefully consider extranuclear factors operating in oncogenesis.

Quantitative and qualitative electron microscopic studies were performed on the leukemic cells of 3 patients with stem cell leukemia, 6 patients with acute lymphoblastic leukemia, 7 patients with acute monoblastic leukemia, 3 patients with acute myeloblastic leukemia and 7 patients with acute monomyeloblastic leukemia. Significant quantitative differences were noted between some of the leukemic cells in heterochromatin:euchromatin ratios, cell size, granules per cell, amount of endoplasmic reticulum and the number of polyribosomes. Qualitative abnormalities which were found in some cells of all the leukemic groups were observed. These abnormalities included nuclear pockets, deep nuclear indentations (usually not the stem cell), nucleosomes, dilated perinuclear spaces, centrioles located in nuclear pockets (not in the stem cell or lymphoblast), accumulation of microfibrils (greatest in the monoblast and myeloblast), disrupted mitochondria with virus-like particles (none in stem cells), smaller granules and mitochondrial DNA, glycogen, and myelin whorls. The presence of the smaller granules in disrupted mitochondria and the resulting clear areas is probably related to the deranged carbohydrate metabolism of these cells. The presence of virus-like particles within mitochondria may be extremely important, but requires much more investigation. Some of the above findings may offer clues to further investigation of the acute leukemic cell.