Inhibition of human lymphocyte reactivity by plasma fibronectin in vitro

The effect of purified human plasma fibronectin (FN) on the reactivity of human lymphocyte-rich mononuclear cells to mitogens and allogeneic cell interactions was studied. Concentrations of FN from 25 to 100 micrograms per 250 microL of culture consistently depressed phytohemagglutinin (PHA) responses. To exert an inhibitory effect, FN must be present within 20 hours after the addition of PHA to cells, and, therefore, it appears to interfere with early events in the transformation process. Increasing the concentration of PHA failed to reduce the inhibitory effect of FN, which suggests that the depressed response was not the result of FN-PHA complex formation, which would reduce the amount of mitogen available for stimulation. This possibility was supported by the finding that FN also inhibited the mixed lymphocyte response (MLR), in a reaction that was not dependent on the activity of soluble antigen or mitogen. In contrast, the stimulation of lymphocytes to undergo transformation that is induced by the nonlectin mitogen, sodium periodate, was unaffected by FN. Periodate-treated cells are, however, already stimulated to undergo transformation, prior to their exposure to FN. FN did not interfere with the activity of interleukin-2, nor did it indirectly regulate lymphocyte responses by modifying the production and/or effect of humoral regulatory factors released from the adherent accessory cells (macrophages). These studies show that FN is a potent immunosuppressive agent in vitro.     

Influence of fibronectin-containing blood products on lymphocyte reactivity

Two fibronectin (FN)-containing blood products, human peripheral blood plasma and cryoprecipitate, were examined for their effect on mitogen-induced lymphocyte transformation in vitro. Responses of human peripheral blood lymphocytes to phytohemagglutinin (PHA) were depressed in the presence of a plasma concentration above that required for maximum DNA synthesis, and this concentration must be present in cultures prior to lymphocyte activation. The removal from the plasma of heparin-induced cryoprecipitate, a complex consisting of FN, heparin, and fibrinogen, resulted in a significant reduction in the inhibitory effect of the plasma on the PHA response. Plasma specifically depleted of FN by affinity chromatography on gelatin-agarose beads was 32 percent less inhibitory to the PHA-induced stimulation of cells than untreated plasma; the remaining inhibitory activity in the FN-depleted plasma samples was attributed to the presence of other normal immunosuppressive factors. The inhibitory capacity of FN in plasma was similar to that obtained with purified FN alone, which indicates that, unlike that of other known plasma inhibitors, the immunosuppressive activity of FN was not altered by the presence of other components of plasma. Cryoprecipitate used in the treatment of hemophilia contains high levels of FN, and, as anticipated, PHA-induced lymphocyte transformation was markedly depressed in the presence of solubilized cryoprecipitate. The contribution of FN to the T-cell abnormalities in patients chronically receiving cryoprecipitate and/or factor VIII concentrates derived from cryoprecipitate warrants further investigation.     

Interictal spikes on intracranial recording: behavior, physiology, and implications

Purpose: The physiological, pathological, and clinical meaning of interictal spikes (IISs) remains controversial. We systematically analyzed the frequency, occurrence, and distribution of IISs recorded from multiple intracranial electrodes in 34 refractory epileptic patients with respect to seizures and antiepileptic drug (AED) changes. Methods: Continuous spike counts from all recorded contacts of all implanted electrodes, and also separately for the subset of contacts involved at seizure onset, were tabulated for every hour of every day of recording, and expressed as spikes per hour in six preselected, 24‐h intervals (defined to exclude seizures): (1) on medications; (2) prepreseizure; (3) preseizure; (4) postseizure; (5) off meds; and (6) resumed meds. Mean spike rates were analyzed for differences between designated 24‐h intervals. Results: Spike rate in all recorded contacts consistently and significantly decreased after AED withdrawal, despite variability in initial spike rate, diurnal occurrence, seizure character/number/localization of onset, and type(s) of AED continued or withdrawn (p < 0.0001). A significant increase in spike rate was noted in the 24  h after seizures of medial temporal origin, in the medial temporal lobe contacts; neocortical onset seizures did not show any increase. Conclusions: These observations confirm and extend previous reports, suggesting a general effect of AED withdrawal, and a more specific effect of medial temporal lobe seizures, on IIS rate. AED mechanisms and efficacy might be demonstrated by quantifying IIS with changes in AEDs. Furthermore, variability in IIS rate after seizures distinguishes localization of seizure onset in medial temporal versus neocortical locations.     

A novel dual-target steroid sulfatase inhibitor and antiestrogen: SR 16157, a promising agent for the therapy of breast cancer

Endocrine therapy is the ideal treatment choice for estrogen receptor α (ERα)-positive breast cancer patients. Principal used therapies target either the ERα e.g. by selective ERα modulators (SERMs) such as tamoxifen or target estrogen biosynthesis with aromatase inhibitors. Steroid sulfatase (STS) plays a crucial role in formation of compounds with estrogenic properties, converting inactive sulfate-conjugated steroids to active non-conjugated forms. Steroid sulfates are considered as a reservoir for active steroids due to their prolonged half-life and increased concentration in plasma. STS is present in several tissues including the breast, and the STS the mRNA level and enzyme activity is significantly increased in ERα-positive breast tumors. Inhibition of STS is therefore a new approach for decreasing estrogenic steroids that stimulate breast cancer. The novel dual-acting compound SR 16157 is designed as a sulfamate-containing STS inhibitor that releases a tissue-selective SERM SR 16137. Use of a dual-target STS inhibitor and SERM represents a new strategy in the treatment of hormone-dependent breast cancer. In this study, we tested the potential of SR 16157 and SR 16137 on STS activity, cell growth and ERα function in MCF-7 breast cancer cells. We confirmed that the dual-target compound SR 16157 exerts STS inhibition and antiestrogenic effects. SR 16157 was a highly effective growth inhibitor, being 10 times more potent than the antiestrogens SR 16137 and tamoxifen. Relative to tamoxifen, SR 16137 displays profoundly improved ERα binding affinity and antiestrogenic effects on expression of estrogen-regulated genes. Thus, the dual-target SR 16157 is possibly a promising new treatment alternative, superior to tamoxifen.     

Different options for treatment of inverting papilloma of the nose and paranasal sinuses: a report of 41 cases.

Forty-two cases of inverting papilloma of the nose and paranasal sinuses were reviewed from 1972 to 1989. Forty-one patients underwent surgical excision. Of those patients followed up for at least 6 months, lateral rhinotomy was performed in 14 patients and midfacial degloving in 9 patients. The recurrence rates were 29% and 22%, respectively. The other 10 patients underwent excision through an external ethmoidectomy, Caldwell-Luc operation, or intranasal approach. There were five patients (12%) diagnosed with squamous cell carcinoma associated with inverting papilloma. The correlation of malignancy with proptosis, visual changes, infraorbital hypesthesia, and skull base involvement on presenting symptomatology is noted. Inverting papilloma is a benign neoplastic lesion that shows variable aggressiveness. A computed tomography (CT) scan evaluation is very important for the work-up. An aggressive wide surgical excision is best performed through an open approach. The approach for surgical removal should be based on the location and extension of the lesion. A graduating approach from a lesser to a more major excision is advocated even though a risk exists of having to reoperate in about one fifth of the patients who experience a recurrence. A secondary surgical excision, even with craniofacial resection, is essential to eradicate disease in cases of recurrence. Close follow-up is necessary. Further surgery may be indicated. Post-operative radiation therapy is recommended if malignancy is indeed present.     

One-step assembly in yeast of 25 overlapping DNA fragments to form a complete synthetic Mycoplasma genitalium genome

We previously reported assembly and cloning of the synthetic Mycoplasma genitalium JCVI-1.0 genome in the yeast Saccharomyces cerevisiae by recombination of six overlapping DNA fragments to produce a 592-kb circle. Here we extend this approach by demonstrating assembly of the synthetic genome from 25 overlapping fragments in a single step. The use of yeast recombination greatly simplifies the assembly of large DNA molecules from both synthetic and natural fragments.