A simplified screening test for the diagnosis of allergy.

The Quidel allergy screen is a relatively rapid (less than 2 hours) multiallergen dipstick method for detecting specific immunoglobin E antibodies in serum. It was developed to answer the need of primary physician nonspecialists in allergy for a convenient in-office screening test for diagnosing allergy. The new test was evaluated against the benchmark diagnostic skin tests and the radioallergosorbent serologic tests for sensitivity, specificity, accuracy, and technical feasibility in an office setting. It was found that while the Quidel allergy screen lacks the specificity of the standard tests, its overall sensitivity, as defined by the percentage of patients with positive skin reactions who also tested positive with the Quidel screen (68%), its ease of use, and its rapidity warrant its consideration as a screening tool for confirming a possible case of allergy.     

Intestinal lactase in the neonatal rat. Maturational changes in intracellular processing and brush-border degradation

The mechanism of decline in the catalytic activity of intestinal lactase during neonatal maturation has not been defined, but a shift in the lactase subunit synthesis from an active 130-kDa subunit to an inactive 100-kDa species has now been noted in the adult rat (Quan, R., Santiago, N. A., Tsuboi, K. K., and Gray, G. M. (1990) J. Biol. Chem. 265, 15882-15888). The subunit structure, synthesis, intracellular assembly, and subsequent degradation of lactase from the brush-border surface membrane was examined in 15-day-old pre-weaned and 30-day-old post-weaned intact rats. Lactase was labeled intraintestinally with [35S]methionine, isolated from Triton-solubilized membranes with monospecific polyclonal anti-lactase, and analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and autoradiography. The protein-stained gel revealed subunits of 225 and 130 kDa, the latter species predominating in both the pre- and post-weaned state. The distinct adult-type 100-kDa moiety was present in post-weaned animals while only a trace of a slightly larger (approximately 110 kDa) species was observed in pre-weaned animals. Quantitation of radioactivity in newly synthesized lactase revealed an increasing prominence of the 100-kDa species in post-weaned rats (130/100 incorporation ratio: pre-weaned 6.2; post-weaned 3.3). Accumulation of newly labeled lactase in brush-border membranes after intraperitoneal [35S]methionine labeling was similar in both groups at 3 h. Despite these comparable rates of lactase synthesis, assembly and insertion in the pre- and post-weaned state, subsequent removal of the 130-kDa unit was more rapid in post-weaned animals (t1/2 = 11 h; pre-weaned t1/2 = 37 h). In intact rats, the neonatal maturational decline in lactase catalytic activities involves both a shift to production of the inactive 100-kDa subunit and increased membrane surface degradation of the active 130-kDa subunit.     

Effects of high and low molecular soluble factors of the bone marrow on antibody formation and pain sensitivity in animals

In addition to the immunostimulating activity, bone marrow mediators, myelopeptides (MP) show the dose-dependent effect on the development of pain sensitivity in mice. When injected in nanogram amounts, MP induce hyperalgesia and 3-9 fold higher production of antibodies against SREC. When injected in milligram amounts, they exhibit hypoalgesic effect and no influence on antibody production. Immunostimulating effect in MP (mol, mass less than 1 KD, fraction 3) is accompanied with hypoalgesia. Bone marrow factors of mol. masses 40-150 KD (fraction 1) eluted at Sephadex G-25 gel-filtration before MP enhance the pain sensitivity tHreshold and show a potent immunodepressive effect. Thus the bone marrow factors are capable of exhibiting the opposite effects on the immune system in the pain control system that evidences the tight interrelation between these systems.     

The participation of cholinergic structures at different levels in shaping the immediate adaptation of the pancreas to food quality in ontogeny

The experiments on rats showed that the urgent enzymatic adaptations of the pancreas to the quality of food have not been inherent, but have been created in the ontogeny. These adaptations are usually absent during transition to the definitive feeding (23rd day of life). Adaptation for protein stimulant appears in the moment of taking away of mother (30th day of life) and becomes persistent for protein and fat stimulants by the 90th day of life (adult rats). The blockade of different levels' cholinergic structures prevents the normal development of urgent specific pancreas adaptations in all investigated ages.     

The Relationship between Hierarchical Chiral Structures of Proteins and their Functions

Biophysics - The specific characteristics of the distribution of secondary structures and coiled-coil superhelix structures were investigated for the first time, while taking the sign of chirality...     

Development of the digestive system of Argentine hake,Merluccius hubbsi,larvae

The Argentine hake Merluccius hubbsi is an important fishery resource of the Southwestern Atlantic Ocean and it is also a potential species for cultivation. In this work, the digestive system development in field-caught hake larvae was studied using histological and histochemical approaches. The digestive tract of larvae was divided into: oropharyngeal cavity (OPC), esophagus, stomach (that develops in the preflexion stage), and intestine. The annexed digestive glands consisted of the liver and the exocrine pancreas. At the beginning of the preflexion stage, teeth were developed in the OPC. There were mucous cells in the esophagus secreting different glycoconjugates from hatching. The enterocytes in the posterior intestine exhibited supranuclear vesicles associated with protein absorption. Mucous cells were observed in the posterior intestine in the preflexion stage and, in the anterior region, ending the flexion stage. Each type of glycoconjugates has a specific role. Acidic mucins lubricate and protect from mechanical damage, sialomucines protect from bacterial infections and neutral mucins regulate the acidity of mucus secretion, protect against abrasion and participate in the formation of the chyme, indicating a pregastric digestion. The liver was present since hatching with pancreatic tissue inside and increased in size acquiring the typical structure with hepatocyte cords, sinusoids, vacuoles, and hepatic duct. The hepatocytes vacuolization increased with larval development. The pancreas became extra-hepatic, with basophilic acinar cells and acidophilic zymogen granules. Throughout the ontogeny, the increased structural and functional complexity of the digestive system reflected the transition to exogenous feeding and nutritional increasing needs.