In the public interest?

Restrictive patenting and licensing for cell-free fetal DNA testing has serious consequences for technology advances and benefits to public health.     

In Vitro and In Vivo Effects of Genistein on Murine Alveolar Macrophage TNFα Production

The present study was performed to determine whether genistein could inhibit in vivo LPS-induced alveolar macrophage TNF production and thus reduce the alveolar neutrophil influx following LPS. In vitro incubation with genistein completely inhibited LPS-induced TNF production by alveolar macrophages (AM) from BALB/c mice. Subsequently mice were pretreated with intraperitoneal genistein or vehicle, then received nasal LPS to induce an alveolitis. Genistein was then administered every eight hours for five days following LPS. At 24 hours after LPS, the bronchoalveolar lavage (BAL) TNF and ex vivo TNF production from AM, were lower in the genistein treated animals. As well, total BAL white blood cell (WBC) count was reduced in the genistein as compared to the vehicle-only group. The percent neutrophils and the resolution of neutrophils were similar between genistein and vehicle groups. Therefore, genistein was able to decrease AM TNF production, and was associated with a decrease in BAL WBC count post-LPS.     

Hydrophilic and lipophilic radiopharmaceuticals as tracers in pharmaceutical development: In vitro – In vivo studies

Background

Scintigraphic studies have been performed to assess the release, both in vitro and in vivo, of radiotracers from tablet formulations. Four different tracers with differing physicochemical characteristics have been evaluated to assess their suitability as models for drug delivery.

Methods

In-vitro disintegration and dissolution studies have been performed at pH 1, 4 and 7. In-vivo studies have been performed by scintigraphic imaging in healthy volunteers. Two hydrophilic tracers, (^99mTc-DTPA) and (^99mTc-MDP), and two lipophilic tracers, (^99mTc-ECD) and (^99mTc-MIBI), were used as drug models.

Results

Dissolution and disintegration profiles, differed depending on the drug model chosen. In vitro dissolution velocity constants indicated a probable retention of the radiotracer in the formulation. In vivo disintegration velocity constants showed important variability for each radiopharmaceutical. Pearson statistical test showed no correlation between in vitro drug release, and in vivo behaviour, for ^99mTc-DTPA, ^99mTc-ECD and ^99mTc-MIBI. High correlation coefficients were found for ^99mTc-MDP not only for in vitro dissolution and disintegration studies but also for in vivo scintigraphic studies.

Conclusion

Scintigraphic studies have made a significant contribution to the development of drug delivery systems. It is essential, however, to choose the appropriate radiotracers as models of drug behaviour. This study has demonstrated significant differences in release patterns, depending on the model chosen. It is likely that each formulation would require the development of a specific model, rather than being able to use a generic drug model on the basis of its physicochemical characteristics.     

Dynamic In Situ Cytometry Uncovers T Cell Receptor Signaling during Immunological Synapses and Kinapses In Vivo

Upon antigen recognition, T?cells form either static (synapses) or migratory (kinapses) contacts with antigen-presenting cells. Addressing whether synapses and kinapses result in distinct T?cell receptor (TCR) signals has been hampered by the inability to simultaneously assess T?cell phenotype and behavior. Here, we introduced dynamic in?situ cytometry (DISC), a combination of intravital multiphoton imaging and flow cytometry-like phenotypic analysis. Taking advantage of CD62L shedding as a marker of early TCR signaling, we examined how T?cells sense TCR ligands of varying affinities in?vivo. We uncovered three modes of antigen recognition: synapses with the strongest TCR signals, kinapses with robust signaling, and kinapses with weak signaling. As illustrated here, the DISC approach should provide unique opportunities to link immune cell behavior to phenotype and function in?vivo.     

Cloning and Overexpression of TGF-β1 cDNA in a Mammary Adenocarcinoma: In Vitro and In Vivo Effects

Abstract

It has been suggested that transforming growth factor beta (TGF-β) may be a potential negative autocrine growth regulator of carcinomas including mammary carcinomas. To directly test this hypothesis we have cloned and expressed human TGF-β1 cDNA in a murine mammary adenocarcinoma which is normally growth-inhibited by addition of exogenous TGF-β in vitro. A number of transfectants over-expressing the foreign TGF-β1 mRNA were selected amd compared to transfectants which did not overexpress the exogenous TGF-β1 cDNAS. Cell lines overexpressing the transfected TGF-β1 mRNA were found to produce total levels of TGF-β7 to 10 fold greater than the parental cells or control transfected clones. However, when levels of active fractions of TGF-β were compared in cell lines overexpressing TGF-β1 to those which did not, no differences were found. This suggests that the activation mechanism is not necessarily induced or altered by increasing levels of latent TGF-β production in a given tumor cell line. The basal in vitro doubling time of TGF-β1 overexpressing clones was identical to the control populations. Similarly, in vivo tumor growth rates after S.C. injection were similar to that of the parental line. Thus the precise role of TGF-β in mediating either the in vitro or in vivo growth control of a sensitive mammary adenocarcinoma cell line remains unclear. It may be that cellular over-secretion of latent TGF-β must be coupled with enhanced cellular TGF-β activation prior to any observed effect on growth rate in vitro or in vivo; this latter event may constitute the “rate-limiting” step of TGF-β activity on tumor behavior.     

In vitro study of a novel low-lensity-lipoprotein adsorbent

Hypercholesterolemia has been identified as a major risk factor in the develop-ment of premature atherosclerosisand in clinical sequelae like coronary artery diseaseand myocardial infarction.Studies on LDL apheresis hasbeen carried outby unselec-tive plasma exchange,double membrane filtration,chemoadsorption,immunoad-sorption and heparin- induced extracorporeal LDL precipitation.In this paper,we de-veloped a new LDL adsorbentof dextran modified cholesterol linked to agar- beads.METHODSSy…