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  • rat  (3)
  • IDDM  (2)
  • Taste hairs  (2)
  • 03.65.-w  (1)
  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Journal of comparative physiology 186 (2000), S. 193-203 
    ISSN: 1432-1351
    Keywords: Key wordsEristalis tenax ; Pollen ; Taste hairs ; Contact chemoreception ; Proline
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract The labellar gustatory system of the dronefly Eristalis tenax L. (Syrphidae; Diptera) that enables the fly to discriminate between pollen and nectar is investigated, and the triggering of pollen ingestion is examined. In behavioural preference tests, exhaustively extracted pollen of the sunflower Helianthus annuus is consumed in smaller amounts than untreated pollen, indicating that water-soluble substances are important for acceptance. Dry pollen is preferred over moist pollen in which the grains stick together, suggesting that mechanical properties of the pollen also play a role in its sensory assessment. Electrophysiological studies of the labellar taste hairs reveal that aqueous extracts of pollen (2% w/v) stimulate the salt receptor cell, but not the sugar receptor cell. The response of the water receptor cell remains the same as to pure water (or standard electrolyte, 10 mmol · l−1 KCl). Of the 20 amino acids tested, the salt cell is sensitive only to proline in a submillimolar range. Behavioural experiments support the electrophysiological findings. When KCl is applied at concentrations eliciting salt-cell spike frequencies equal to those produced by pollen extract (which is often accepted), the water receptor cell is inhibited and a pronounced rejection behaviour occurs. This rejection of concentrated salt solution in Eristalis is therefore mainly mediated by the inhibition of the water cell.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Diabetologia 14 (1978), S. 325-328 
    ISSN: 1432-0428
    Keywords: Diabetes ; hypertrophy ; kidney ; nephrectomy ; rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The kidney growth seen after the induction of experimental diabetes in rats has been compared to the compensatory renal growth after one-sided nephrectomy. After five days the kidney weight had increased from 650 ± 15 mg in a group of controls to 778 ± 21 mg in diabetic rats, and 764 ±17 mg in unilaterally nephrectomised rats. The increased weight was in both groups reflected in an increased DNA content and increased RNA/DNA and protein/DNA ratios. In a group of rats made diabetic and nephrectomised at the same time, kidney weight increased to 953 ± 22 mg after five days. When rats were unilaterally nephrectomised after 20 days of untreated diabetes, compensatory growth was much more pronounced than in non-diabetic rats, kidney weight rising from 780 ± 21 to 1144 ± 39 mg in five days. Similarly, in rats with established compensatory renal hypertrophy, diabetes induced a very rapid growth of the remaining kidney (1226 ± 46 mg after five days).
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Diabetologia 13 (1977), S. 141-143 
    ISSN: 1432-0428
    Keywords: Blood glucose ; diabetes ; DNA ; hypertrophy ; kidney ; rat ; Streptozotocin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Streptozotocin diabetic rats have larger kidneys than non-diabetic rats. In the present study the rate of kidney growth during the first seven days of diabetes was correlated with the blood glucose concentration. Over a wide range of blood glucose concentrations (116–340 mg/100 ml) the kidney weight, protein content and protein/DNA ratio were closely correlated with the glucose values.
    Type of Medium: Electronic Resource
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  • 4
    ISSN: 1432-0428
    Keywords: Keywords Diabetic retinopathy ; 24-h ambulatory blood pressure ; IDDM ; urinary albumin excretion.
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The role of blood pressure elevation in the incidence and progression of diabetic retinopathy is not clearly established and results have been conflicting. Blood pressure and urinary albumin excretion (UAE) are closely related. In order to evaluate the independent relationship between retinopathy and blood pressure elevation, precise information on UAE is essential, as confounding by renal disease (incipient or overt), cannot otherwise be excluded.The aim of the present study was to evaluate the association between diabetic retinopathy and 24-h ambulatory blood pressure (AMBP) in a group of well-characterized normoalbuminuric IDDM patients. In 65 normoalbuminuric (UAE 〈 20 μg/min) IDDM patients we performed 24-h AMBP (Spacelabs 90 207) with readings at 20-min intervals. Fundus photographs were graded independently by two experienced ophthalmologists. UAE was measured by RIA and expressed as geometric mean of three overnight collections made within 1 week. HbA1 c was determined by HPLC. Tobacco use and level of physical activity were assessed by questionnaire. Fifteen patients had no detectable retinal changes [grade 1], 35 had grade 2 retinopathy; and 15 had more advanced retinopathy [grade 3–6]. Diastolic night blood pressure was significantly higher in patients with diabetic retinopathy compared to patients without retinopathy (68 ± 8 mmHg [grade 3–6] and 65 ± 6 mmHg [grade 2], compared to 61 ± 4 mmHg [grade 1], p = 0.02). Diurnal blood pressure variation was significantly blunted in the patients with retinopathy as indicated by a higher night/day ratio of diastolic blood pressure (84.6 % ± 4 [grade 3–6], and 81.2 % ± 6 [grade 2] compared to 79.1 % ± 4 [grade 1], p = 0.01). Heart rate tended to be higher in patients in group 2 and 3–6 compared to patients without retinopathy with p values of 0.07 and 0.11 for day-time and 24 h values, respectively. Mean HbA1 c increased significantly with increasing levels of retinopathy (p 〈 0.01). Patients were similar regarding sex, age, tobacco use, and level of physical activity. Notably, UAE was almost identical in the three groups (5.0 × /÷1.7 [grade 1], 3.9 × /÷1.8 [grade 2], and 5.1 × /÷1.6 μg/min [grade 3–6]). In conclusion, night blood pressure is higher and circadian blood pressure variation blunted in patients with retinopathy compared to patients without retinopathy despite strict normoalbuminuria and similar UAE levels in the groups compared. Our data suggest that the association between blood pressure and diabetic retinopathy is present also when coexisting renal disease is excluded. Disturbed diurnal variation of blood pressure is a pathophysiological feature related to the development of both retinopathy and nephropathy in IDDM patients. [Diabetologia (1998) 41: 105–110]
    Type of Medium: Electronic Resource
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  • 5
    ISSN: 1432-0428
    Keywords: Diabetes ; growth hormone ; hypertrophy ; kidney ; rat ; streptozotocin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Normal and diabetic rats were given daily injections of human growth hormone for four days (5 mg per rat per day). Injected rats showed no differences from uninjected controls with respect to kidney weight or renal content of protein, RNA or DNA. Kidney weight increased by 7% after two days of diabetes and by 20% after four days, but growth hormone caused no augmentation of the hypertrophy. It is concluded that growth hormone plays no role in the initiation of diabetic renal hypertrophy.
    Type of Medium: Electronic Resource
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  • 6
    ISSN: 1432-0428
    Keywords: Keywords Ambulatory blood pressure ; autonomic control ; heart rate variability ; spectral analysis ; IDDM ; microalbuminuria ; diabetic nephropathy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Significant changes in both blood pressure, autonomic function and kidney ultrastructure are observed in insulin-dependent diabetic (IDDM) patients with microalbuminuria. Intervention strategies are evaluated at even earlier stages of disease. Identification of patients at risk of developing microalbuminuria must be based on a thorough knowledge of the relations between key pathophysiological parameters in patients with normoalbuminuria. The aim of the present study was to characterize the interactions of urinary albumin excretion (UAE), 24-h ambulatory blood pressure (AMBP), and sympathovagal balance in a large group of normoalbuminuric IDDM patients. In 117 normoalbuminuric (UAE 〈 20 μg/min) patients we performed 24-h AMBP (Spacelabs 90 207), with assessment of diurnal blood pressure and heart rate (HR) variation, and short-term (three times 5 min) power spectral analysis of RR interval oscillations, as well as cardiovascular reflex tests (HR variation to deep breathing, postural HR and blood pressure response). Patients with UAE above the median (4.2 μg/min) had significantly higher 24-h systolic and diastolic AMBP (125 ± 10.1/76 ± 7.2 mmHg) compared to the low normoalbuminuric group (120 ± 8.4/74 ± 5.1 mmHg), p 〈 0.01 and 0.02, respectively. Patients with UAE above the median had significantly reduced short-term RR interval variability including both the high frequency component (5.47 ± 1.36 vs 6.10 ± 1.43 ln ms2), and low frequency component (5.48 ± 1.18 ln ms2 compared to 5.80 ± 1.41 ln ms2), p 〈 0.02 and p = 0.04 (ANOVA). In addition, patients with high-normal UAE had reduced mean RR level (faster heart rates) 916 ± 108 compared to 963 ± 140 ms, p 〈 0.04. These differences were not explained by age, duration of diabetes, gender, level of physical activity, or cigarette smoking. HbA1 c was significantly higher (8.6 ± 1.2 vs 8.2 ± 1.0 %, p = 0.03) in the group with high normal UAE. Comparing normoalbuminuric IDDM patients with UAE above and below the median value, we found significantly higher AMBP in combination with significant differences in sympathovagal balance and significantly poorer glycaemic control in the group with high-normal albumin excretion. Our data demonstrate interactions between albumin excretion, blood pressure, autonomic function, and glycaemic status, already present in the normoalbuminuric range and may describe a syndrome indicative of later complications. [Diabetologia (1997) 40: 718–725]
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    Springer
    Cell & tissue research 117 (1971), S. 419-442 
    ISSN: 1432-0878
    Keywords: Taste hairs ; Insects ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung Die Schmeckhaare der Fliege Phormia terraenovae enthalten fünf Rezeptorzellen (vier Kontaktchemo- und eine Mechanorezeptorzelle), die von zwei Hüllzellen unter Aussparung von Lymphräumen („Vakuole“) umgeben sind. Die Rezeptorzellen gliedern sich in Axon, Zellkörper und Dendrit, der aus Innenglied, Übergangsabschnitt und Außenglied besteht. Der Übergangsabschnitt hat die 9+0-Struktur der modifizierten Cilien mit zwei Basalkörpern. Im Plasma der Außenglieder sind nur Mikrotubuli zu erkennen. Die Außenglieder der Kontaktchemorezeptoren ziehen durch die röhrenförmige Dendritenscheide und den Kanal I des Haarschafts bis zu einem Porus in der Haarspitze, durch den sie mit den Schmeckstoffen in Kontakt kommen (Ort der Primärprozesse). Das Außenglied der Mechanorezeptorzelle enthält einen tubulären Körper und setzt an der Haarbasis an. Die Hüllzelle II (tormogene Zelle) bildet zum großen Sensillenlymphraum hin ein stark gefaltetes Membransystem aus. Der Feinbau wird in Beziehung zur Funktion der Schmeckhaare gesetzt.
    Notes: Summary The tarsal taste hairs of the blowfly contain five receptor cells: four contact chemoreceptors and one mechanoreceptor. These cells are surrounded concentrically by two sheath cells with fluid-filled spaces (“vacuoles”) between them. The receptor cell parts are the axon, the cell body, and the dendrite. The latter has an inner segment, a transitional region, and an outer segment. The transitional region shows the 9+0 configuration of a modified cilium with two basal bodies. In the outer segment only microtubules are found. The outer segments of contact chemoreceptors pass through the tube-like dendrite sheath, then through “canal I” of the hair shaft, to reach the pore at the tip of the hair. The outer segment of the mechanoreceptor contains a “tubular body” and terminates at the hair base. The “sheath cell II” (tormogene cell) forms a folded membrane system toward the main liquor space. The fine structure of the tarsal taste hairs is discussed in relation to their function.
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  • 8
    ISSN: 1434-6079
    Keywords: 36.40 ; 35.20.Wg ; 03.65.-w
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract Measurements of the mass abundance spectra of sodium clusters containing up to 600 atoms are presented. The clusters are produced in a seeded supersonic expansion of Ar or Kr gas, and the spectra are obtained by a time-of-flight technique. The sawtooth features in the spectra are interpreted as evidence of a regular spherical shell structure with magic numbers,N 0, scaling approximately with the cube root of the number of sodium atoms. Altogether twelve shell closings are observed,N 0=2, 8, 20, 40, 58, 92, 138, 196, 260, 344, 440 and 558. There is also a pronounced odd-even staggering all the way up toN=70. The experimentally observed intensity changes for the clusters around the magic numbers are discussed in terms of the electronic free energy,F(N), calculated at finite temperature, and the second differences of the free energy Δ2 F(N)=F(N−1)−2F(N)+F(N+1). The processes behind the non-uniform abundance distributions, and the thermodynamics of finite electron systems with non-uniform level spacings are discussed on this basis.
    Type of Medium: Electronic Resource
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