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C Schubert

Publications and source records attributed to C Schubert.

105 records · Page 6Linked to original sources
PubMed1976

Histological and histochemical observations on the neurosecretory cells in the diencephalon of Chthonerpeton indistinctum and Ichthyophis paucisulcus (Gymnophiona, Amphibia).

In the diencephalon of two species of Gymnophiona (Amphibia) two neurosecretory nuclei were examined with histological (Alcian Blue, Aldehyde Fuchsin, Brookes Trichrome stain) and enzyme histochemical techniques (acid phosphatase, alpha-naphthyl acetate esterase, acetylcholinesterase (AChE)). In the preoptic nucleus two categories of secretory neurons were distinguished: large and medium sized neurons. The perikarya of both cell types contain very little neurosecretory material. The Alcian Blue method stained the medium sized neurons faintly but selectively. The tractus praeopticohypophyseus is marked by the presence of Herring bodies, which, however, are relatively scarce. The neurohypophysis, in contrast, contains large amounts of neurosecretory material. Both cell types of the preoptic nucleus are characterized by their very strong AChE and alpha-naphthylacetate esterase activity. The AChE also marks the tractus praeoptico-hypophyseus. In the large neurons acid phosphatase is present around the nucleus; in the medium sized neurons this enzyme is concentrated close to the origin of the axon. In the dorso-caudal hypothalamus a small group of neurons is stained with Alcian-Blue. These neurons, which also contain AChE, are located immediately under the ependyma which seems to be specialized in this region.

Acetylcholinesterase↗
PubMed1976

The influence of temperature on the thyroid gland of Chthonerpeton indistinctum (Gymnophiona, Amphibia).

The thyroid gland of the tropical amphibian Chthonerpeton is markedly stimulated when the animal is exposed for two days to relatively high temperatures (36 degrees C). Control animals were kept at 20 degrees C. The stimulated gland exhibits collapsed follicles and a very tall follicular epithelium. At the ultrastructural level the activated epithelial cells were characterized by an increased number of apical microvilli, increased amounts of rough endoplasmic reticulum, an extended Golgi apparatus and a high number of various granular and vesicular inclusions. These differences in histology and fine structure were not paralleled by quantitative results, which were approximately the same in both groups of animals. The values of these determinations were relatively high.

Amphibians↗
PubMed1976

Temperature dependent changes in the thyroid gland of Mertensiella caucasica (Urodela, Amphibia).

The influence of temperature on the thyroid gland of the Caucasian salamander, Mertensiella caucasica has been studied (1) with the light- and electron microscopes, (2) with enzyme histochemical and quantitative methods. Animals which had been kept for years at 16 degrees C were exposed for 48 hrs to 4 degrees C or 27 degrees C. At 4 degrees C the follicular epithelium consisted of cuboidal cells with well-developed rough ER, occasional distended cisternae of the rough endoplasmic reticulum (ER) filling most of the cytoplasm, a relatively small Golgi apparatus and numerous round or oval shaped lysosomes. In animals kept at 27 degrees C the follicular wall was composed of markedly taller epithelial cells, the apices of which bulged into the follicular lumen. Compared to the animals at 4 degrees C, there appeared to be a decrease in the rough ER. The Golgi apparatus did not exhibit clear differences. The lysosomes increased in number and showed various shapes among which elongated ones with pointed ends were particularly striking. In the apical cytoplasm colloid droplets appeared indicating hormone release. The apical microvilli increased in number. The measurements of total T4 have shown that the hormone level in animals kept at 27 degrees C was about twice as high as in animals kept at 4 degrees C.

Animals↗
PubMed1975

Observations on the fine structure, enzyme histochemistry, and innervation of parathyroid gland and ultimobranchial body of Chthonerpeton indistinctum (Gymnophiona, Amphibia).

Fine structural and enzyme histochemical observations on ultimobranchial body and parathyroid gland of the caecilian Chthonerpeton are presented. The cell clusters and follicles of the ultimobranchial body consist mainly of granulated cells which are termed C-cells and obviously belong to the APUD cell series. In the larger follicles additional possibly exhausted degranulated cells and replacement cells occur. A rich supply of nerve fibres has been found in this gland. Frequently nerve terminals were observed to come into synaptic contact with the C-cells. Two categories of nerve fibres occur: a) fibres containing large polymorphic electron dense granules (probably purinergic fibres), b) fibres containing small electron transparent vesicles and a few electron dense granules (probably cholinergic fibres). The parathyroid gland consists of elongated cells (one cell type) poor in organelles and often containing fields of glycogen and lipid droplets. The cells are further characterized by fair amounts of lysosomal enzymes; they are interconnected by maculae adhaerentes and occludentes. No nerves and blood vessels have been found in the parathyroid gland of Chthonerpeton.

Acid Phosphatase↗
PubMedDate not supplied

Public response to elevated nitrate in drinking water wells in Wisconsin.

The authors conducted a survey by mail of Wisconsin families who had their well water tested for nitrate to (a) assess their awareness and compliance with the state's health advisories for nitrate, (b) evaluate their reaction(s) to their test results, and (c) compare demographic differences between exposure levels. Owners of contaminated wells (i.e., > 12.9 mg/l nitrate-nitrogen) were more likely to have lived on a farm, had lower annual incomes, and had older and shallower wells than families whose wells were low in nitrate (i.e., < 2.0 mg/l nitrate-nitrogen). Most respondents were aware of the advisories for pregnant women and infants and, in accordance with these advisories, the majority of families with nitrate-contaminated drinking water took no remedial action. Given that many rural families consume nitrate-contaminated water daily, scientists should conduct additional research to determine whether chronic ingestion of nitrate-contaminated water poses a significant health threat to these families.

Adult↗
PubMedDate not supplied

Daily psychosocial stressors interfere with the dynamics of urine neopterin in a patient with systemic lupus erythematosus: an integrative single-case study.

OBJECTIVE: Systemic lupus erythematosus (SLE) is a chronic autoimmune disease characterized by flare-ups, the causes of which are not known. In accordance with new concepts in stress research, this study investigated whether daily psychosocial stressors interfere with immunological processes in SLE. Because such processes are unique to each individual, single-case design using time-series analysis (Box and Jenkins) was applied. METHODS: A 40-year-old woman with SLE (last flare-up September 1995) was interviewed initially to determine major life events and difficulties (using the Life Events and Difficulties Schedule) in the previous 2 years. She was then observed for 63 days. Urine neopterin, an immunological parameter demonstrated to parallel disease activity in SLE patients, was measured in daily overnight urine. Daily incidents were identified weekly by the Incidents and Hassles Inventory and independently rated. Intervening factors, including infections, medication, and lifestyle, were controlled. RESULTS: Retrospectively, data obtained from the Life Events and Difficulties Schedule indicated that major life events and difficulties had preceded the patient's last flare-up in 1995. Although there were no clinical signs of SLE during this prospective study of 63 days, cross-correlational analyses revealed that "moderately" stressful incidents associated with higher levels of emotional irritation (lag 0: +0.271, p < .05) predicted an increase in urine neopterin the following day (lag 1: +0.441, p < .05). Moreover, a 7-day cyclicity in neopterin levels that corresponded to the weekly examinations and interviews was found. CONCLUSIONS: This study showed a causal relationship between psychosocial stressors and urine neopterin concentrations that may be related to SLE disease activity. Furthermore, the workability of an integrative approach using single-case design and time-series analysis in psychoneuroimmunology was demonstrated for the first time.

Adult↗
PubMedDate not supplied

Efficacy and tolerability of enalapril and sustained-release verapamil in older patients with mild to moderate essential hypertension.

The study involved 113 patients over age 50 years with mild to moderate essential hypertension, randomly assigned to treatment with enalapril (n = 54) or sustained-release verapamil (n = 59). During an eight-week titration period, doses were adjusted to achieve supine diastolic blood pressures (DBP) below 90 mmHg; patients were then given maintenance doses for eight weeks. Mean blood pressures were reduced significantly from 147.7/93.9 mmHg at baseline to 137.7/84.5 mmHg at the end of the maintenance period in the enalapril group and from 155.1/95.1 to 142.4/86.2 mmHg in the verapamil group. In the patients who completed treatment, the mean daily doses required to maintain DBP below 90 mmHg were 9.6 mg of enalapril and 244.9 mg of verapamil. There were 11 treatment failures in the enalapril group and 22 in the verapamil group: eight of the enalapril and 17 of the verapamil patients did not attain goal blood pressures and three and five were withdrawn because of side effects. It is concluded that both enalapril and sustained-release verapamil were generally effective and well tolerated in the treatment of mild to moderate hypertension in the middle-aged and older patients.

Aged↗
PubMedDate not supplied

Time-dependent changes in image contrast in brain tumors after gadolinium-DTPA.

Time-dependent changes in the contrast enhancement of tumor tissue, tumor necrosis, perifocal edema, and normal brain tissue after IV injection of 0.1 mmol gadolinium-DTPA/kg body weight were studied with spin-echo technique (SE 800/35) in 15 patients with intracranial tumors. Using a region of interest technique, we determined the signal-intensity values of these tissues before and at fixed times up to 68.5 min after administration of the contrast agent. In tumor tissue, the 8.5 min postinjection (p.i.) scan showed a significant increase in signal intensity. The signal intensity of the tumor tissue remained significantly higher than precontrast levels throughout the entire period of observation, decreasing only slightly toward the end of the examination (48.5 and 68.5 min p.i.). Central tumor necrosis exhibited a delayed uptake of the contrast agent, with a maximum signal intensity between 48.5 and 68.5 min p.i. In perifocal edema and normal brain tissue, slight increases in signal intensity after injection of gadolinium-DTPA were measured (statistically significant in the case of edema). This effect, however, was not visually detectable. The present study shows that after one injection, scans with excellent tumor visualization can be obtained between 8.5 and 38.5 min p.i. and with diagnostically valid enhancement at least up to 68.5 min p.i.

Adult↗