TNF receptor-deficient mice reveal divergent roles for p55 and p75 in several models of inflammation

The pleiotropic activities of the potent proinflammatory cytokine TNF are mediated by two structurally related, but functionally distinct, receptors, p55 and p75, that are coexpressed on most cell types. The majority of biologic responses classically attributed to TNF are mediated by p55. In contrast, p75 has been proposed to function as both a TNF antagonist by neutralizing TNF and as a TNF agonist by facilitating the interaction between TNF and p55 at the cell surface. We have examined the roles of p55 and p75 in mediating and modulating the activity of TNF in vivo by generating and examining mice genetically deficient in these receptors. Selective deficits in several host defense and inflammatory responses are observed in mice lacking p55 or both p55 and p75, but not in mice lacking p75. In these models, the activity of p55 is not impaired by the absence of p75, arguing against a physiologic role for p75 as an essential element of p55-mediated signaling. In contrast, exacerbated pulmonary inflammation and dramatically increased endotoxin induced serum TNF levels in mice lacking p75 suggest a dominant role for p75 in suppressing TNF-mediated inflammatory responses. In summary, these data help clarify the biologic roles of p55 and p75 in mediating and modulating the biologic activity of TNF and provide genetic evidence for an antagonistic role of p75 in vivo.     

Vertical Sulfur Dioxide,Ozone, and Heavy Metal Concentration Profiles Above the Southern Bight of the North Sea

Vertical profiles of SO₂ and O₃ concentrations were measured continuously within the lower atmosphere during 18 flights over the Southern Bight of the North Sea. The average SO₂ concentration below the temperature inversion layer ranged from 1.9 to 19.5 ppb. The highest levels were observed when the air masses came from the southeast-east and under variable wind sector conditions: 15.2 and 12.0 ppb, respectively. The highest SO₂ concentrations were found at altitudes between 100 and 200 m. The overall average O₃ concentration was 46 ppb, with values of 30–40 ppb at sea level to 60–70 ppb at altitudes above 100 m. Low O₃ concentrations reflect O₃ depletion through reaction with freshly emitted pollutants, while high O₃ concentrations are an indication of photochemical activity. O₃ concentrations are primarily dependent on seasonal influences, while SO₂ levels are dictated more by the history of the sampled air mass. The results are discussed in relation to the heavy metal concentrations, measured within the same experiment. In spite of some differences, SO₂ and trace metals showed similar trends. The individual SO₂ and O₃ profiles clearly illustrated the high variability in vertical concentration distributions.     

Uniparental disomy 7 in Silver-Russell syndrome and primordial growth retardation

Maternal uniparental disomy for the entire chromosome 7 has so far been reported in three patients with intrauterine and postnatal growth retardation. Two were detected because they were homozygous for a cystic fibrosis mutation for which only the mother was heterozygous, and one because he was homozygous for a rare COL1A2 mutation. We investigated 35 patients with either the Silver-Russell syndrome or primordial growth retardation and their parents with PCR markers to search for uniparental disomy 7. Four of 35 patients were found to have maternal disomy, including three with isodisomy and one with heterodisomy. The data confirm the hypothetical localization of a maternally imprinted gene (or more than one such gene) on chromosome 7. It is suggested to search for UPD 7 in families with an offspring with sporadic Silver-Russell syndrome or primordial growth retardation.     

Mode-field diameter of single-mode fiber by knife-edge scanning in the far field

Knife-edge scanning has been applied to the far-field patterns of both matched-clad and depressed-clad single-mode fiber at 1300 nm. The method offers several advantages as compared with other techniques. The mode-field diameter (MFD) has been derived according to a Gaussian fitting procedure, and values agree closely with those obtained with the other standardized procedures.     

ArF-excimer laser-induced secondary radiation in photoablation of biological tissue

Secondary radiation, emitted during and after the irradiation of corneal, dermal, and dental tissue by an ArF-excimer laser (193 nm), was qualitatively and quantitatively characterized. Emission of secondary radiation was found in the range of 200-800 nm. The intensity of secondary radiation in the range of 200-315 nm (UVC and UVB) is approximately 20% of the total intensity at high laser fluences (> 2 J/cm2), and approximately 50% at moderate laser fluences (< 500 mJ/cm2); 10 muJ/cm2 in the UVC and UVB were measured at the sample surface, at fluences (< 1J/cm2) which are of relevance for clinical procedures on soft tissues. In dental tissue processing, very high fluences (> 5 J/cm2) are required. As a consequence, laser-induced plasma formation can be observed. Secondary radiation can be used as a visible guide for selective removal of carious altered tissue. The data we have found might be of assistance in estimating potential hazards for future mutagenic studies in the field.     

Aplastic anaemia and thymonal

The combination of aplastic anaemia and thymona was observed in a 49-year old woman. Concomitant with severe normochromic anaemia and reticulocytopenia was a cell-rich bone marrow smear in which erythropoietic precursors were almost absent. Immunological phenomena could not be demonstrated. The erythropoietin level was maximally increased. Pathological anatomy typically revealed a predominantly spindle-cell thymonal with only minor capsular invasion.     

Adolescent psychological and social predictors of young adult smoking acquisition and cessation: A 10-year longitudinal study.

Objective: A 10-year follow-up study to test the extent to which theory-based adolescent psychological and social factors directly predict and moderate the prediction of young adult smoking acquisition and cessation. Design: A prospective community-based sample. A total of 2,970 adolescents participated in the large Washington State Hutchinson Smoking Prevention Project (HSPP) longitudinal cohort. As predictors, psychological factors (i.e., parentnoncompliance, friendcompliance, rebelliousness, achievement motivation, and thrill seeking) and social environmental factors (i.e., parent's and friend's smoking) were measured when adolescents were 17–18 years old. Main Outcome Measures: As main outcome measures, smoking acquisition and cessation were assessed both at ages 18 and 28. Results: Psychological and social factors predicted 3% to 7% probability (p     

Electrical impedance tomography for imaging tissue electroporation

Electroporation is a method to introduce molecules, such as gene constructs or small drugs, into cells by temporarily permeating the cell membrane with electric pulses. In molecular medicine and biotechnology, tissue electroporation is performed with electrodes placed in the target area of the body. Currently, tissue electroporation, as with all other methods of molecular medicine, is performed without real-time control or near-term information regarding the extent and degree of electroporation. This paper expands the work from our previous study by implementing new ex vivo experimental data with "front-tracking" analysis for the image reconstruction algorithm. The experimental data is incorporated into numerical simulations of electroporation procedures and images are generated using the new reconstruction algorithm to demonstrate that electrical impedance tomography (EIT) can produce an image of the electroporated area. Combining EIT with electroporation could become an important biotechnological and medical technique to introduce therapeutic molecules into cells in tissue at predetermined areas of the body.