Search PubMed⌕ Search

Biomedical subjects

J Roth

Publications and source records attributed to J Roth.

At least 595 records · Page 33Linked to original sources

Applications of immunocolloids in light microscopy. Preparation of protein A-silver and protein A-gold complexes and their application for localization of single and multiple antigens in paraffin sections.

The protein A-gold (pAg) complex, a useful reagent for electron microscopic localization of antigens in thin sections, is tested for its suitability as second step reagent in light microscopic immunohistochemistry. In addition, the preparation of colloidal silver, its complex formation with staphylococcal protein A and the application of the protein A-silver complex for antigen localization in paraffin sections is reported. The antigens were visualized in a two-step technique with specific antisera in the first incubation step and pAg or pA-silver as a general second step reagent. The pAg complex gives a red coloration of antigenic sites, whereas the pA-silver stained yellow. The contrasting color provided by the two immunocolloids allowed localization of two antigens in the same section. No color mixing occurred, showing that removal of the antibodies of the first staining sequence is unnecessary. Staining is virtually permanent with the light microscopic immunocolloid method. It is concluded that pAg and pA-silver complexes are useful as general second step reagents for the localization of a variety of antigens in paraffin sections.

Animals↗

Insulin is present in chicken eggs and early chick embryos.

We showed that insulin appears in the chick embryo before beta-cells are recognizable, as well as in the egg constituents even before fertilization. Acid-ethanol extracts of 2- to 8-day-old embryos were gel-filtered on Sephadex G-50. The peak of immunoreactive insulin chromatographed in a position corresponding to that of authentic insulin. The immunoreactive insulin extracted from embryos was approximately 2 ng/g wet wt during early embryogenesis (days 2, 3, and 4), with a 2- to 3- fold increase by days 5 and 6, in conjunction with pancreatic development. The heads of the embryos contributed 22-23% of the total insulin on days 3 and 4, but only 5% by day 5. Based on its reactivity in a pork insulin RIA, chicken insulin RIA, and rat adipocyte bioassay, we concluded that the material is very similar to avian (chicken or turkey) rather than mammalian type insulin. Similar immunological and biological insulin-like activity [but at much lower concentrations (0.2-0.8 ng/ml)] were recovered from the gel-filtered acid-ethanol extracts of yolk and white of unfertilized and fertilized eggs. This study, which shows that insulin is present at a very early stage in ontogeny, extends observations that insulin is native to organisms that lack pancreatic islets, including flies, worms, and microbes.

Adipose Tissue↗

Decreased insulin binding in cultured lymphocytes from two patients with extreme insulin resistance.

[125I]Insulin binding has been studied in two patients with extreme insulin resistance using cultured B-lymphocytes transformed with Epstein-Barr virus. A cell line from a female infant with leprechaunism had insulin binding which was decreased 90% below the lower limit of normal. Lymphocytes from a young woman with type A extreme insulin resistance (associated with acanthosis nigricans and virilization) had insulin binding which was 80% depressed. In both cases, the defect in binding resulted from a decrease in the number of receptors per cell. The remaining receptors had normal properties, including a normal affinity for insulin and a normal specificity for insulin analogs. Insulin binding in cultured lymphocytes from these two insulin-resistant patients was also inhibited normally by antibodies to the insulin receptor. Immunological assays using anti-receptor antibodies confirmed the conclusion that the number of receptors was decreased. Affinity labeling of the leprechaun insulin receptor with [125I]insulin demonstrated the existence of an alpha-subunit with apparently normal molecular weight (130,000 daltons). However, the number of receptor molecules per cell appeared reduced.

Adolescent↗

Insulin resistance associated with androgen excess in women with autoantibodies to the insulin receptor.

Hirsutism, polycystic ovaries, and elevated levels of plasma testosterone are characteristic clinical features in women with extreme insulin resistance and acanthosis nigricans. Extreme insulin resistance resulting from autoantibodies to the insulin receptor (type B extreme insulin resistance) had been considered an exception to this generalization. A woman with type B extreme insulin resistance developed clinical evidence of masculinization in association with a markedly elevated level of plasma testosterone (1000 ng/dL). In nine women with autoantibodies to the insulin receptor, excessive ovarian production of testosterone was a common feature among the premenopausal patients. Postmenopausal patients rarely developed elevated levels of plasma testosterone, presumably as a result of ovarian failure. Overproduction of testosterone may result from a direct effect of hyperinsulinemia on the ovary.

Acanthosis Nigricans↗

[Lipowitz metal as attenuating material for electron rays with an energy of 3 to 45 MeV (author's transl)].

Shielding blocks made of lipowitz metal are used for electron irradiation with irregularly shaped fields. Depending on the thickness of the block, the attenuation of electrons with an energy of 3 to 45 MeV produced by an Asklepitron 45 was examined at the surface and at the depth dose maximum. The necessary thickness of the shielding blocks made of Lipowitz metal in order to achieve a defined attenuation depends largely on the electron energy.

Electrons↗

[The effect of bronchial reactivity on the hemodynamics of the pulmonary circulation in the early diagnosis of chronic non-specific lung diseases].

For the early diagnostics of chronic nonspecific pulmonary disease reversible functional disorders in persons without any symptoms and those with manifest obstruction should be identified. Provocation tests with acetylcholine-ultrasonic-aerosol have proved themselves. In 25 persons without any respiratory symptoms and in 27 patients with manifest obstruction the reactions of increased airway resistance to the hemodynamic of the pulmonary circuit were studied. It is possible to separate clearly groups with different pulmonary artery stream resistance measured by means of microheart-catheterization after inhalation of 0.01% acetylcholine-ultrasonic-aerosol.

Acetylcholine↗

[Ultrastructural visualization of binding and internalization of cholera and tetanuts toxins].

In monolayer cultures of a liver line, a population of non-coated membrane microinvaginations is preferentially involved in both the initial binding and subsequent internalization of colloidal gold-labelled cholera and tetanus toxins. These two toxins thus appear to be internalized via another pathway than most other polypeptide ligands studied, which enter cells via coated plasma membrane invaginations.

Animals↗

[Relationship of closing volume to other lung function tests].

The closing volume method is suitably to be used in exposed groups of the population, the preliminary diagnostics of them is inconspicuous, in order to establish in time beginning and thus therapeutically influencible alterations of the small respiratory tract. In such a group of test persons only relatively slight connections with the other conventional lung standard methods are the result, by means of which its independence is emphasized. On the other hand less promising seems to be the application of the method in the verification of a "small airways obstruction" in smokers, whose vital capacity, forced expiratory volume and residual volume are within the normal.

Adult↗

Specific neurons in chick central nervous system stain with an antibody against chick intestinal vitamin D-dependent calcium-binding protein.

A specific antiserum against intestinal vitamin D-dependent calcium-binding protein (CaBP) was used for a systematic immunohistochemical evaluation of immunoreactive sites in the central nervous system of chick. CaBP was observed in the perikarya, dendrites and axons of a specific population of neurons. It is concluded that CaBP represents a marker for selected neurons in the central nervous system of chick.

Aging↗

Vitamin D--dependent calcium binding protein: immunocytochemical localization in chick kidney.

A vitamin D--dependent calcium binding protein in the chick kidney that was detected by immunocytochemical techniques was localized exclusively in the distal convoluted tubule, the initial collecting tubule, and the early part of the collecting tubule. The intercalated (mitochondria-rich) cells in these tubular segments were negative for the calcium binding protein. Subcellularly, the protein was found in the cytosol and the nucleus of the tubular cells. The results suggest a role for vitamin D--dependent calcium binding protein in intracellular calcium metabolism rather than a direct involvement in membrane-mediated calcium reabsorption in the avian kidney.

Animals↗

Purification of the putA gene product. A bifunctional membrane-bound protein from Salmonella typhimurium responsible for the two-step oxidation of proline to glutamate.

In this paper we report the purification of a protein which is able to catalyze both the proline oxidase and the pyrroline-5-carboxylic acid dehydrogenase activities necessary for the oxidation of proline to glutamic acid. The purification involves the preparation of a crude membrane pellet, detergent solubilization, ammonium sulfate fractionation, and DEAE-chromatography. We are able to obtain an essentially pure preparation (greater than 95% pure) after only a 52-fold purification, demonstrating that the protein is a major protein in cells fully induced for proline utilization. Both proline oxidase and pyrroline-5-carboxylic acid dehydrogenase activities co-purity throughout our purification. Velocity sedimentation of the purified protein demonstrates that both proline oxidase and pyrroline-5-carboxylic acid dehydrogenase activities co-sediment. Early in the purification procedure we are able to detect two species of protein which have both proline oxidase and pyrroline-5-carboxylic acid dehydrogenase activities. Our procedure purifies only the larger molecular weight species. The purified protein is a dimer composed of identical 132,000-dalton subunits. Analysis of mutants defective for proline utilization demonstrate that the bifunctional enzyme is the putA gene product.

1-Pyrroline-5-Carboxylate Dehydrogenase↗