dcc Haploinsufficiency results in blunted sensitivity to cocaine enhancement of reward seeking.

Mesocortical dopamine connectivity continues to mature during adolescence. This protracted development confers increased vulnerability for environmental and genetic factors to disrupt mesocortical wiring and subsequently influence responses to drugs of abuse in adulthood. The netrin-1 receptor, DCC, orchestrates medial prefrontal cortex dopamine input during adolescence and dictates the functional organization of local circuitry. Haploinsufficiency of dcc results in increased dopamine innervation to the medial prefrontal cortex, which in turn leads to resilience against the behavioral activating effects of stimulant drugs. However, whether sensitivity to the rewarding effects of drugs of abuse is also altered in dcc haploinsufficiency remains to be resolved. Here, we used the curve-shift method to measure cocaine-induced facilitation of intracranial self-stimulation (ICSS) in adult dcc haploinsufficient mice and wild-type littermates. We found that dcc haploinsufficient mice acquire ICSS behavior at comparable stimulation parameters to wild-type controls. However, cocaine-induced potentiation of ICSS is significantly blunted in dcc haploinsufficient mice. These results are consistent with decreased sensitivity to the rewarding effects of cocaine and/or decreased proclivity to invest effort in the pursuit of reward in dcc haploinsufficient mice. Moreover, these findings suggest that DCC signaling determines adult susceptibility to drug abuse most likely by controlling prefrontal cortex development in adolescence.

The effects of salivas on occlusal forces.

Contacting surfaces of opposing teeth produce friction that, when altered, changes the contact force direction and/or magnitude. As friction can be influenced by several factors, including lubrication and the contacting materials, the aim of this study was to measure the occlusal load alterations experienced by teeth with the introduction of different salivas and dental restorative materials. Pairs of molar teeth were set into occlusion with a weighted maxillary tooth mounted onto a vertical sliding assembly and the mandibular tooth supported by a load cell. The load components on the mandibular tooth were measured with three opposing pairs of dental restorative materials (plastic denture, all-ceramic and stainless steel), four (human and three artificial) salivas and 16 occlusal configurations. All lateral force component measurements were significantly different (P < 0·0001) from the dry (control) surface regardless of the crown material or occlusal configuration, while the effects of the artificial salivas compared to each other and to human saliva depended on the crown material.

TLR-mediated B cell activation results in ectopic CLIP expression that promotes B cell-dependent inflammation.

Infectious pathogens produce compounds called Toll ligands that activate TLRs on lymphocytes. Acute activation triggered by certain TLRs appears to "jump start" the innate immune response, characterized by the release of inflammatory cytokines and cellular expansion. In some individuals, there is a failure to control acute inflammation, resulting in postinfectious, chronic inflammation. Susceptibility to chronic inflammation is strongly associated with an individual's MHC genes. Recent clinical trials for several autoimmune diseases characterized by chronic inflammation suggest that B lymphocyte depletion therapies dampen chronic immune activation. However, currently, there is no known mechanism that accounts for the correlation among TLR activation, MHC genetics, and a pathological role for B-lymphocytes. Our hypothesis is that TLR-activated B cells (B cells that have been polyclonally activated in the absence of antigen-specific signals) are not controlled properly by T cell-dependent B cell death, thereby causing B cell-dependent chronic inflammation. Here, we show that treatment with Toll ligands results in polyclonal B cell activation accompanied by ectopic expression of CLIP. Furthermore, by adoptively transferring purified CLIP+ B cells in syngeneic animals, we find that CLIP+ B cells induce production of TNF-α by host T cells. Finally, we demonstrate that CLIP-targeted peptide competition results in the death of polyclonally activated CLIP+ B cells.

Upregulation of TRAIL expression on human T lymphocytes by interferon beta and glatiramer acetate.

We measured the in vivo and in vitro effects of interferon (IFN)beta and glatiramer acetate (GA) on the expression of the regulatory molecule, tumor necrosis factor related apoptosis inducing ligand (TRAIL), in patients with multiple sclerosis (MS). We confirmed the prior observation that TRAIL is enhanced on anti-CD3 activated T cells by the in vitro addition of IFNbeta. T cells from IFNbeta-treated patients stimulated with anti-CD3 only, had higher levels of TRAIL than untreated patients, suggesting that in vivo IFNbeta exposure has an effect on TRAIL expression in association with T cell activation. In vitro IFNbeta-induced TRAIL upregulation on anti-CD3 or phytohemagglutinin-activated T cells was comparable for IFNbeta-treated and non-treated MS patients and controls, indicating that IFN receptors were neither saturated nor down-regulated by current IFNbeta therapy. Although GA in vivo or in vitro did not induce TRAIL, the IFNbeta +GA combination in vitro enhanced TRAIL expression to higher levels than IFNbeta alone on CD4+ T cells obtained from MS patients, regardless of GA treatment status, and healthy donors, and on GA reactive T cell lines derived from GA-treated patients or controls. Whether any observed therapeutic effects of GA/IFNbeta combination therapy will correlate with TRAIL expression and function remains to be determined.

NK cell-mediated lysis of autologous human oligodendrocytes.

Although considered an autoimmune disease, the mechanisms underlying oligodendrocyte (OL)/myelin injury in multiple sclerosis (MS) remain to be established. We utilized in vitro assays to demonstrate that human OLs, as well as other glial elements (astrocytes, microglia), were susceptible to injury mediated by peripheral blood-derived mononuclear cell preparations (MNCs) enriched for natural killer (NK cells) by depleting CD3(+) +/- CD19(+) cells through use of either magnetic beads or cell sorting. Cytotoxic effects of the NK cell-enriched effectors were dependent on pre-exposure of these cells to IL-2. Furthermore, we found that autologous OLs were as susceptible to injury mediated by IL-2 activated NK cells as were heterologous OLs. In context of the tissue injury that occurs in MS, our results suggest that the inflammatory milieu in MS lesions could provide conditions required for NK cell activation and that such effector cells can bypass the putative protective effects of self-MHC class I molecules that may be expressed on OLs.

Superantigen presenting capacity of human astrocytes.

We found that human fetal astrocytes (HFA) are able to support superantigen (SAG) staphylococcal enterotoxin B (SEB) and toxic shock syndrome toxin-1 (TSST-1)-induced activation of immediately ex vivo allogenic human CD4 T cells. Using radiolabelled toxins, we demonstrate that both SEB and TSST-1 bind with high affinity to MHC class II antigen expressing astrocytes; binding is displaceable with excess cold toxin. Competition experiments further indicate that TSST-1 and SEB at least partially compete with each other for binding to astrocytes suggesting they bind to the same HLA-DR region on these cells. Our study supports the hypothesis that SAG would be capable of stimulating immune responses within the human CNS and contribute to persistence or recurrence of inflammatory responses within this compartment.

Interferon-gamma secretion by peripheral blood T-cell subsets in multiple sclerosis: correlation with disease phase and interferon-beta therapy.

Interferon-gamma (IFN-gamma) is implicated as a participant in the immune effector and regulatory mechanisms considered to mediate the pathogenesis of multiple sclerosis (MS). We have used an intracellular cytokine staining technique to demonstrate that the proportion of ex vivo peripheral blood CD4 and CD8 T-cell subsets expressing IFN-gamma is increased in secondary progressing (SP) MS patients, whereas the values in untreated relapsing-remitting (RR) MS patients are reduced compared with those of controls. Patients treated with interferon-beta (IFN-beta) have an even more significant reduction in the percentage of IFN-gamma-secreting cells. The finding that the number of IFN-gamma-expressing CD8 cells is increased in SPMS patients, a group with reduced functional suppressor activity, and is most significantly reduced by IFN-beta therapy, which increases suppressor activity, indicates that IFN-gamma secretion by CD8 T cells and functional suppressor defects attributed to this cell subset in MS can be dissociated.

Non-MHC-restricted cell-mediated lysis of human oligodendrocytes in vitro: relation with CD56 expression.

Oligodendrocytes and their myelin membranes are the apparent target of the autoimmune response that characterizes the human adult central nervous system-demyelinating disease multiple sclerosis. Human oligodendrocytes do not express MHC class II molecules, a requirement for MHC-restricted injury mediated by myelin-reactive CD4+ T cells, the cell type implicated in initiating the disease process. In this study we observed that human adult central nervous system-derived oligodendrocytes can be susceptible to non-MHC-restricted lysis mediated by myelin basic protein-reactive CD4+ T cell lines. Cytotoxicity was significantly greater (37 +/- 4 vs 7 +/- 3%) with cell lines in which a high proportion of cells (mean, 28 +/- 6%) expressed CD56 compared with cytotoxicity mediated by low CD56 cell lines (8 +/- 2%). High CD56 cell lines, when rested in IL-2, lost cytotoxic activity and had reduced expression of CD56 (mean, 5 +/- 2%). CD4+ T cells isolated from short term (3-day) anti-CD3/IL-2-activated mononuclear cell cultures did not express CD56 and were not cytotoxic to oligodendrocytes unless lectin was added. In contrast, an enriched population of non-T cells extracted from the same activated MNC cultures expressed CD56 as well as other NK cell-associated surface molecules and was cytotoxic. These results indicate the potential susceptibility of human oligodendrocytes to non-MHC-restricted injury mediated by both Ag-reactive and nonspecific cellular immune effector cells, with CD56 expression being a common feature of the effector cells.

Differential susceptibility of human CNS-derived cell populations to TNF-dependent and independent immune-mediated injury.

We examined whether oligodendrocytes, neurons, and astroglia derived from the human central nervous system differ in susceptibility to injury mediated by tumor necrosis factor (TNF)-alpha and by activated CD4+ T cells acting via a TNF-independent mechanism. Injury was assessed either as cell membrane-directed (lysis), measured by 51chromium (Cr) or lactate dehydrogenase (LDH) release, or nucleus-directed (apoptosis), measured by morphologic features based on propidium iodide (PI) staining and by DNA fragmentation measured by a terminal transferase (TdT)-mediated dUTP biotin nick end labeling technique (TUNEL). TNF did not induce 51Cr or LDH release in any cell targets, but did induce nuclear (66 +/- 2% of cells) and DNA (68 +/- 2% of cells) fragmentation selectively in the oligodendrocytes over 96 hr. At this time, there was no significant loss of oligodendrocyte cell number. Nuclear injury could be induced in neurons by serum deprivation and in malignant astrocytes by the combination of TNF and low serum. CD4+ T cells activated with phytohemagglutin (pha) or anti-CD3 plus interleukin-2 induced significant 51Cr and LDH release in all target cells tested; only pha-activated CD4+ T-cell cocultures showed reduced target cell numbers. Significant nuclear fragmentation was observed only for glioma cells (22 +/- 1% of cells). Differences in susceptibility to different immune effector mechanisms and in the nature of the injury response to the same effector mediator among human CNS-derived neural cells will need to be considered in design of therapeutic strategies aimed at protecting or limiting target cell injury consequent to disease or trauma.

T cell-mediated cytotoxicity of human gliomas: a tumor necrosis factor-independent mechanism.

Cellular immune effector mechanisms are implicated as potential therapies for malignant gliomas. We have examined the potential for anti-CD3-activated human peripheral blood-derived CD4+ and CD8+ T cells to induce lysis of human glioma cell lines in vitro, the mechanism of action of these cells, and the capacity of the glioma to inhibit the effect. We found that activated CD4+ and CD8+ T cell preparations containing less than 5% natural killer cells could induce significant lysis of the glioma cell line U251, as measured by an 18-hour, but not 5-hour, chromium-51 or lactate dehydrogenase release assay. This effect was not reproduced using recombinant tumor necrosis factor or inhibited with antitumor necrosis factor antibody. Anti-lymphocyte functional antigen-1 and anti-intercellular adhesion molecule antibodies also did not inhibit the effect. Glioma-derived supernatant could inhibit the proliferation of the T cells but not the cytotoxic effect. Human fetal astrocytes were also susceptible to the cytotoxic effect of the activated T cells. These results indicate that activated T cells can induce glioma cytotoxicity via a mechanism independent of tumor necrosis factor. The therapeutic potential of this effector mechanism will depend on its capacity to deliver these cells or their specific effector molecules to the tumor site or to augment the activity of such cells, which accumulate naturally in gliomas.

Inflammatory breast disease: mammographic spectrum.

We reviewed 27 biopsy-proven cases of inflammatory disease of the breast. Mammographic features of acute and chronic breast inflammation and abscess included focal increased density (68%), a spiculated mass (56%), skin thickening (48%), skin retraction (28%), and microcalcification (8%). We found considerable similarity between inflammation and malignancy.

Cytolysis of mammary tumor targets by resting, interleukin-2 stimulated and in vitro cultured peripheral blood lymphocytes from breast cancer patients.

The cytotoxic capacity of resting, interleukin-2 (IL-2)-stimulated and in vitro cultured (3-5 days in 10 U/ml IL-2 containing media) peripheral blood lymphocytes (PBLs) from breast cancer patients to a panel of established mammary tumor cell lines was ascertained. Significant cytolysis (ranging from 7.8 to 12.4%, at an effector: target ratio of 20:1) of all mammary tumor targets (MCF-7, 734B, ZR-75-1, ZR-75-30, BT-20 and Hs578T) by PBLs was demonstrable in 18 h chromium release assays. Natural killer (NK) cytotoxicity was distinct from IL-2 stimulated (5 U/ml) and in vitro cultured PBL cytotoxicity in that resting PBLs were not cytolytic to RAJI cells, normal breast epithelia (Hs578Bst) and fibroblasts. Basal NK activity against mammary tumor targets was significantly reduced in patients receiving chemotherapy when compared to both untreated patients and normal controls. In criss-cross cold target inhibition studies, ZR-75-1 and K562 targets were not mutually competitive in NK cell assays (using resting PBLs) but were mutually competitive in lymphokine-activated killer (LAK) assays (using in vitro cultured PBLs). In eleven independent experiments, basal NK activity of ZR-75-1 cells was increased by a cold target excess of K562 (8.2 +/- 2.4% vs 30.5 +/- 5.2%, mean +/- SE, p greater than 0.01, cold:hot target ratio = 10:1). Interestingly, no such parallel increase of cytolysis of 734B targets by K562 cells was observed. Basal cytotoxicity against ZR-75-1 and K562 targets was serologically depleted using antibodies to natural killer cells HNK-1 and Leu 11b. Thus mammary tumor cell lines parallel autologous tumor cells, yet show features that are distinct from NK-resistant and sensitive lymphoid cell lines in their susceptibility to natural resistant cytolytic mechanisms.

Plain film evaluation of patients with abdominal pain: are three radiographs necessary?

Current recommendations for the plain radiographic evaluation of abdominal pain suggest a minimum three-film series including an erect and supine abdominal view and an erect chest study. Three film radiographic abdominal "series" were obtained in 252 consecutive emergency-room patients who presented with abdominal pain. The views were analyzed independently for their relative diagnostic value. Radiologic pathologic findings were present in 20% of the abdominal films and in 13% of the chest radiographs. The supine abdominal view and the erect chest study diagnosed normality or abnormality in 98% of these patients. The elimination of the erect abdominal view from the routine abdominal series could result in financial savings, decreased radiation exposure, and a more efficient use of technician time, without significant loss of diagnostic information.

Cystosarcoma phyllodes.

We present four cases of cystosarcoma phyllodes in which mammograms revealed a small or large lobulated mass occupying the entire breast. Preoperative diagnosis was a benign lesion with a low probability of nodular carcinoma. Histologically, all tumors were classified as malignant. Although uncommon, cystosarcoma should be considered in the differential diagnosis of these masses, since local recurrence is frequent unless wide wedge resection or simple mastectomy is done.

Computed tomography of the chest in small cell lung cancer: potential new prognostic signs.

Computed tomography (CT) of the chest was performed as part of the initial and subsequent staging evaluations in 33 patients with small cell lung carcinoma. In 25 of the 33 patients, CT demonstrated findings not observed on standard radiography. Eleven of the 33 would have been staged higher using CT. Before treatment, CT revealed more mediastinal and nodal involvement than conventional films. After chemotherapy, CT demonstrated areas of residual or early recurrent disease in nine of 28 patients that were not apparent on chest films. Initially thickened pericardium in patients with limited disease and persistent bronchial narrowing after chemotherapy were demonstrated to be associated with early relapse in the chest and short survival. These initial data suggest that the CT scan, in addition to more accurately assessing the extent of disease, can provide a new risk classification for early chest relapse. Initial thickened pericardium in limited disease and continued bronchial narrowing after chemotherapy may allow patient selection for future treatment trials with radiation as an adjuvant to chemotherapy.

Resolution of pulmonary cyst after steroid therapy of asthma.

Emphysematous lung cysts in rare instances are associated with bronchial asthma, as evidenced by our patient and possibly another. Particularly in young patients, a trial period of steroid therapy should be instituted to confirm this possible association, to avoid unwarranted surgery and its attendant morbidity.

Metastases to the breast.

Metastases to the breast are uncommon, with about 250 cases reported from clinical and autopsy series. The mammographic findings in 16 new cases revealed a spectrum of changes that included solitary or multiple lesions, well demarcated or poorly marginated masses, and diffuse involvement of skin or parenchyma or both. Diffuse disease was seen more frequently in this series (4/16), at times simulating inflammatory breast cancer. Although diagnosis of a primary malignancy usually preceded detection of the breast lesion, 40% (6/16) had no history of malignancy. Prognosis remains poor; however, it has improved in the lymphoma-leukemia group due to improved immunotherapeutic and chemotherapeutic regimens. The clinical, radiologic, and pathologic features are discussed. Some of the lesions encountered can be confused with a primary breast malignancy or a benign lesion, necessitating prompt and accurate biopsy to preclude unnecessary major surgery and to improve survival in cancers amenable to current therapy.

Chemotherapy for metastatic basal cell carcinoma.

Metastatic basal cell carcinoma is a rare, malignant neoplasm associated with poor survival. A 63-year-old woman had an extensive primary keratinizing basal cell carcinoma of the scalp, with metastases to the regional lymph nodes of the neck. Disease in the primary site and in the regional lymph nodes was controlled by surgery and irradiation. However, skeletal metastases that responded to therapy with three courses of cisplatin and bleomycin sulfate and then to ten courses of cyclophosphamide, methotrexate, and fluorouracil developed. Subsequent progressive metastases failed to respond to a combined cisplatin and cyclophosphamide regimen as well as to etoposide and doxorubicin hydrochloride used as single agents.