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Dragonflies pursue and capture tiny prey and conspecifics with extremely high success rates. These moving targets represent a small visual signal on the retina and successful chases require accurate detection and amplification by downstream neuronal circuits. This amplification has been observed in a population of neurons called small target motion detectors (STMDs), through a mechanism we term pr
Mouse islet cell suspensions were separated into subpopulations based on forward low angle and orthogonal scattered light. Separated fractions were analyzed for hormone content by radioimmunoassays. The pancreatic B‐cells had the highest orthogonal light scattering, while they overlapped in forward low angle light scattering with other endocrine (glucagon, pancreatic polypeptide and somatostatin c
Exposure to international competition on a country level has been shown to improve the efficiency of domestic producers. We contribute to this literature by assessing whether the distance between producers and importers, within a country, matters for import competition effects at product level. Using detailed geographical information about the location of all manufacturing firms in Sweden during t
Two HIV virus types exist: HIV-1 is pandemic and aggressive, whereas HIV-2 is confined mainly to West Africa and less pathogenic. Despite the fact that it has been almost 40 years since the discovery of AIDS, there is still no cure or vaccine against HIV. Consequently, the concepts of functional vaccines and cures that aim to limit HIV disease progression and spread by persistent control of viral
Optical DNA mapping (ODM) allows visualization of long-range sequence information along single DNA molecules. The data can for example be used for detecting long range structural variations, for aiding DNA sequence assembly of complex genomes and for mapping epigenetic marks and DNA damage across the genome. ODM traditionally utilizes sequence specific marks based on nicking enzymes, combined with
Background: Areal bone mineral density (aBMD) estimated by dual-energy X-ray absorptiometry (DXA) is used to estimate peak bone mass, define osteoporosis and predict fracture. However, as aBMD is calculated as bone mineral content (BMC) divided by the scanned area, aBMD displays an inverse relationship with bone size. In a skeleton that is increasing in size, this is a problem, as bone size is an
An antiserum (R4) from a rabbit immunized with suspensions of C57BL/6J ob/ob mouse islet cells contains antibodies which in a 125I-protein A radioligand assay can be demonstrated to bind to single cell suspensions of normal Naval Medical Research Institute (NMRI) mouse islet cells. The binding of 125I-protein A to islet cells was about four times that of normal rabbit serum (NRS) after incubation
It is emphasized that animal models should be used to study specific genotypic or phenotypic expressions associated with diabetes rather than assuming a single animal model can reflect diverse forms of the human disease. Diabetic and normal animals are reviewed on the basis of their usefulness as models of genetic, viral, and chemically induced diabetes, including the often associated immune pheno
The dynamics of insulin and chromium release from prelabelled rat pancreatic islet cells were studied by perifusion of cells supported in a column of Bio-Gel P-2 polyacrylamide beads. The column-perifused β cells released insulin in a biphasic pattern in response to 30 mmol/l D-glucose and in a monophasic pattern to 20 mmol/l L-arginine. Rat islet cells, first exposed
The influence of sex on pancreatic islet B cell susceptibility to streptozotocin was studied in mice given multiple low doses of streptozotocin. Male C3 D2 F1 mice developed a steadily increasing blood glucose level after a lag period of about 3 weeks, in contrast to females who were resistant. Spleen cells from streptozotocin treated female animals produced hyperglycaemia in total body irradiated
Not only has recombinant DNA added another source of insulin for treatment, but also, and perhaps more important, it has allowed the development of new techniques for studying the structure and function of the B cell at the gene level. We can only hope that this information will bring us closer to the understanding of the disease, so the diabetic patient may benefit from other measures of treatmen
Five daily injections of streptozotocin (40 mg/kg) produced a delayed but progressively increasing level of hyperglycaemia in long term studies with male Naval Medical Research Institute mice and C3D2F1 (DBA 2 J male × C3H/ Tif female) F1 hybrid mice. The development of hyperglycaemia was paralleled by decreased amounts of pancreatic immunoreactive insulin as well as degranulation and necrosis of
Pancreatic islets from A.TH mice were transplanted into the spleen or streptozotocin (SZ)‐diabetic A.TL mice. The two strains of mice are congenic inbred strains, differing only in the I and S subregions of the H‐2 complex. The allogeneic islet grafts decreased blood glucose temporarily, but the islets were rejected after 21 ± 7 days (mean ± SD). The effect of skin presensitization was tested by g
Insulin-dependent diabetic (IDD) patients have a high prevalence of circulating autoantibodies against islet of Langerhans cells at the time of diagnosis1-4. Inflammatory cells within the islets5, leukocyte migration inhibition in response to pancreatic antigens6 and an association with certain HLA-D/DR histocompatibility antigens 7,8, have also been observed. It seems that the autoantibodies may
Islet cell cytoplasmic and cell surface antibodies along with other autogenic tissue antibodies were determined prospectively from the day of diagnosis of insulin-dependent diabetes in a group of children and adolescents. Prior to the initiation of insulin therapy 30 out of 33 were antibody-positive, 67% having islet cytoplasmic antibodies and 67% islet cell surface antibodies. Among 74 age- and s
Diabetic A.TL and A.TH mice, congenic inbred strains differing only in the I and S (non-K, non-D) regions of the major histocompatibility (H-2) complex, received intrasplenic allogeneic and isogeneic pancreatic islet transplants. The isografts were uniformly accepted, while approximately 60% of the recipients receiving allografts rejected the islets, most within 4 weeks of transplantation. With ei
