ELECTROPHORETICALLY HOMOGENEOUS ANTIBODY SYNTHESIZED BY SPLEEN FOCI OF IRRADIATED REPOPULATED MICE

106 splenocytes from primed donors were injected, together with sheep erythrocytes (SRBC), into X-irradiated syngeneic mice. 8 days later the spleens were excised and cut into small fragments, keeping track of their location in the organ. Each fragment was cultured individually for 24 hr in the presence of 14C amino acids and the culture fluids were assayed for antibody activity. The antibody-producing fragments were found to be clustered in few restricted areas (foci) surrounded by negative tissue. The anti-SRBC antibody from single foci was purified by absorption on stroma followed by acid elution. Thereafter, it was subjected to electrophoresis and immunoelectrophoresis. The radioautography of the runs showed a considerable degree of homogeneity. Distinct and sharp spikes were localized in the beta and gamma region. The pattern of each focus is unique from the point of view of the number of spikes and their mobility. Eluates obtained from many pooled fragments gave a broad radioactive smear in beta-gamma region. Many foci synthesized antibody migrating as a single band. This homogeneous protein is probably the product of a clone of cells homogeneously differentiated. However, some foci producing two and probably more antibody bands were also encountered. Two interpretations of the finding can be given. Either more than one precursor may participate in the formation of a focus or a differentiation switch may occur during the clonal expansion

A dispersion theoretical approach to the threshold amplitudes of pion photoproduction

We give predictions for the partial wave amplitudes of pion photoproduction near threshold by means of dispersion relations at fixed t. The free parameters of this approach are determined by a fit to experimental data in the energy range 160 MeV $\le E_{\gamma} \le$ 420 MeV. The observables near threshold are found to be rather sensitive to the amplitudes in the resonance region, in particular to the $\Delta$ (1232) and $N^*$ (1440). We obtain a good agreement with the existing threshold data for both charged and neutral pion production. Our predictions also agree well with the results of chiral perturbation theory, except for neutral pion production off the neutron.Comment: 16 pages LATEX including 4 postscript figure

Ultrastructural changes in enterocytes in subjects with Hashimoto's thyroiditis

We have recently described1 mucosal ultrastructural impairments, such as height and thickness of microvilli, space between microvilli, and thickness of tight junctions, in non-coeliac type 1 diabetic patients after a preliminary report of an alteration in intestinal mucosal permeability (IP) evaluated by the lactulose/mannitol (LA/MA) test.2,3 Therefore, in the “aetiological” classification of autoimmunity based on initiating factors,4 the category of diet induced diseases could be expanded to include type 1 diabetes and, perhaps, other endocrine autoimmune diseases. Thyroiditis is the most frequently associated autoimmune endocrine disease with type 1 diabetes. Moreover, type 1 diabetes and Hashimoto thyroiditis present similar pathogenetic mechanisms of cellular damage, a cell mediated autoimmunity induced by Th1 cytokines. However, mucosal intestinal morphology and function have not yet been studied in autoimmune thyroiditis patients. Hence we investigated intestinal mucosal ultrastructural morphology and IP in a group of patients with autoimmune thyroiditis. The study was approved by the local ethics committee. Fourteen patients (12 females and 2 males; mean age 33.2 (SD 10.2) years) and 23 controls (12 females and 11 males; mean age 27.9 (SD 8.01) years) were enrolled into the study after giving written informed consent. The diagnosis of autoimmune thyroiditis was based on the following criteria: plasma autoantibody TPO positive at high titre and a typical thyroiditis ultrasound pattern. All patients were in euthyroidism (normal FT3, FT4, and TSH plasma levels without hormonal therapy). Mean duration of known disease was 5.2 (2.5) years. All patients were negative for the presence of antigliadin antibodies IgA and IgG, antiendomysium antibodies IgA, as well as antihuman transglutaminase IgA following a gluten rich Mediterranean diet. Type 1 diabetes mellitus was excluded according to the 1997 American Diabetes Association criteria, and none of the participants had a family history of diabetes mellitus. Other intestinal and endocrine diseases were excluded through clinical and, when indicated, laboratory evaluation. Food or other allergies were excluded. None of the subjects reported gastrointestinal signs or symptoms, or was a habitual smoker, abuser of alcohol, or regularly took non-steroidal anti-inflammatory drugs

The position and the residues of the delta resonance pole in pion photoproduction

We have analyzed the $M_{1+}^{(3/2)}$ and $E_{1+}^{(3/2)}$ multipole amplitudes of pion photoproduction in the framework of fixed-$t$ dispersion relations. Applying the speed plot technique to our results for these multipoles, we have determined the position and the residues of the $\Delta$ (1232) resonance pole. The pole is found at total $c.m.$ energy $W = (1211 - 50i)$ MeV on the second Riemann sheet, and the ratio of the electric and magnetic residues is $R_{\Delta} = - 0.035 - 0.046 i$, resulting in an E2/M1 ratio for the "dressed" delta resonance of $- 3.5 \%$.Comment: 16 pages LATEX including 5 postscript figures in a self-extracting uufile archiv

WARP: a WIMP double phase Argon detector

The WARP programme for dark matter search with a double phase argon detector is presented. In such a detector both excitation and ionization produced by an impinging particle are evaluated by the contemporary measurement of primary scintillation and secondary (proportional) light signal, this latter being produced by extracting and accelerating ionization electrons in the gas phase. The proposed technique, verified on a 2.3 liters prototype, could be used to efficiently discriminate nuclear recoils, induced by WIMP's interactions, and measure their energy spectrum. An overview of the 2.3 liters results and of the proposed 100 liters detector is shown.Comment: Proceeding for IDM200

High cardiovascular risk in patients with Type 2 diabetic nephropathy: the predictive role of albuminuria and glomerular filtration rate. The NID-2 Prospective Cohort Study

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To Be, or Not to Be: That Is the Hamletic Question of Cryptic Evolution in the Eastern Atlantic and Mediterranean Raja miraletus Species Complex

The ability to correctly identify specimens at the species level is crucial for assessing and conserving biodiversity. Despite this, species-specific data are lacking for many of South Africa’s catsharks due to a high level of morphological stasis. As comprehensive and curated DNA reference libraries are required for the reliable identification of specimens from morphologically similar species, this study reviewed and contributed to the availability of cytochrome c oxidase subunit I (COI) and nicotinamide adenine dehydrogenase subunit 2 (NADH2) sequences for South Africa’s catsharks. A molecular taxonomic approach, implementing species delimitation and specimen assignment methods, was used to assess and highlight any taxonomic uncertainties and/or errors in public databases. The investigated species were summarised into 47 molecular operational taxonomic units (MOTUs), with some conflicting specimen assignments. Two Apristurus specimens sampled in this study remained unidentified, revealing the presence of previously undocumented genetic diversity. In contrast, haplotype sharing within Haploblepharus—attributed to nucleotide ambiguities—resulted in the delimitation of three congeners into a single MOTU. This study reveals that molecular taxonomy has the potential to flag undocumented species and/or misidentified specimens, and further highlights the need to implement integrated taxonomic assessments on catsharks that represent an irreplaceable component of biodiversity in the region

Multipole analysis of pion photoproduction based on fixed t dispersion relations and unitarity

We have analysed pion photoproduction imposing constraints from fixed t dispersion relations and unitarity. Coupled integral equations for the S and P wave multipoles were derived from the dispersion relations and solved by the method of Omnes and Muskhelishvili. The free parameters were determined by a fit to the most recent data for \pi^{+} and \pi^{0} production on the proton as well as \pi^{-} production on the neutron, in the energy We have analysed pion photoproduction imposing constraints from fixed t dispersion relations and unitarity. Coupled integral equations for the S and P wave multipoles were derived from the dispersion relations and solved by the method of Omnes and Muskhelishvili. The free parameters were determined by a fit to the most recent data for \pi^{+} and \pi^{0} production on the proton as well as \pi^{-} production on the neutron, in the energy range 160 MeV \leq E_{\gamma} \leq 420 MeV. The lack of high precision data on the neutron and of polarization observables leads to some limitations of our results. Especially the multipole M_{1-} connected with the Roper resonance P_{11}(1440) cannot be determined to the required precision. Our predictions for the threshold amplitudes are in good agreement with both the data and chiral perturbation theory. In the region of the \Delta(1232) we have determined the ratio of electric quadrupole and magnetic dipole excitation. The position of the resonance pole is obtained in excellent agreement with pion-nucleon scattering, and the complex residues of the multipoles are determined with the speed-plot technique.Comment: 46 pages LATEX including 29 postscript figure

Discovery of underground argon with low level of radioactive 39Ar and possible applications to WIMP dark matter detectors

We report on the first measurement of 39Ar in argon from underground natural gas reservoirs. The gas stored in the US National Helium Reserve was found to contain a low level of 39Ar. The ratio of 39Ar to stable argon was found to be <=4x10-17 (84% C.L.), less than 5% the value in atmospheric argon (39Ar/Ar=8x10-16). The total quantity of argon currently stored in the National Helium Reserve is estimated at 1000 tons. 39Ar represents one of the most important backgrounds in argon detectors for WIMP dark matter searches. The findings reported demonstrate the possibility of constructing large multi-ton argon detectors with low radioactivity suitable for WIMP dark matter searches.Comment: 6 pages, 2 figures, 2 table