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Biomedical subjects

M Ziegler

Publications and source records attributed to M Ziegler.

At least 379 records · Page 21Linked to original sources

Central noradrenergic adaptation to long-term treatment with imipramine in rhesus monkeys.

Rhesus monkeys were treated with the antidepressant drug imipramine; cerebrospinal fluid norepinephrine and dopamine-beta-hydroxylase were measured to assess central noradrenergic activity. Large changes occurred after short-term, but not long-term, treatment. Biochemical stabilization occurs at the time when therapeutic effects are seen in patients.

Acclimatization↗

Radioligand assays-methods and applications. IV. Uniform regression of hyperbolic and linear radioimmunoassay calibration curves.

In order to handle all types of radioimmunoassay (RIA) calibration curves obtained in our laboratory in the same way, we tried to find a non-linear expression for their regression which allows calibration curves with different degrees of curvature to be fitted. Considering the two boundary cases of the incubation protocol we derived a hyperbolic inverse regression function: x = a1y + a0 + a-1y-1, where x is the total concentration of antigen, ai are constants, and y is the specifically bound radioactivity. An RIA evaluation procedure based on this function is described providing a fitted inverse RIA calibration curve and some statistical quality parameters. The latter are of an order which is normal for RIA systems. There is an excellent agreement between fitted and experimentally obtained calibration curves having a different degree of curvature.

Humans↗

Route of pediatric parenteral nutrition: proposed criteria revision.

This study reviews the experience of the Nutrition Support Service at the Children's Hospital of Philadelphia over a 13-mo period from 1977 to 1979. Parenteral nutrition was administered to 585 children, 385 by peripheral vein infusion and 200 by central vein infusion. Weight gain was seen in 63% of those patients receiving peripheral vein infusions and 82.5% of those receiving central vein nutrients, and this apparent difference is likely due to the longer duration of therapy in the central vein recipients (33.7 versus 11.4 mean days) and the greater caloric intake delivered to these same patients (128 Kcal/kg/day versus 63.2 Kcal/kg/day). The complication rates were calculated for the more than 11,000 patient days of therapy surveyed; 35 of the 385 peripheral vein patients developed complications, the primary type being solution administration soft tissue sloughs. This amounted to an incidence of 9.08%. Central vein patients in 40 circumstances likewise had complications, 21 being infectious and 12 being metabolic. This accounted for 20% of all central vein recipients, a difference from the peripheral vein group significant to a p value of less than .01. However, when total days of therapy are considered in this complication incidence, a per diem complication rate between these two groups is not different, and in fact, is somewhat worse for the peripheral vein nutrient recipients. Vascular access in this group of patients was via peripheral vein cannulation or via central venous catheter placement, the latter more recenty done exclusively by percutaneous subclavian vein catheter insertions. This technique was safe and allowed repeated access to the central venous system. These data suggest that the only legitimate determining factor for selecting proper nutritional support of the pediatric patient is the caloric need of the individual.

Amino Acids↗

Validity and stability of a new desired control measure pertaining to psychological adjustment of the elderly.

The four studies reported herein were designed to test the reliabilities and predictive validities of a 70-item Desired Control Measure. This measure is based on the findings of a survey to establish what everyday reinforcements contributed to the happiness of senior citizens. Within the new measure, there were 35 Expectancy items indexing the extent to which senior citizens expected to realize these reinforcements and 35 were Desire items indexing the value older adults held for these reinforcements. The Desire items were used to weight the Expectancy items so as to derive a Desired Control score. Fifteen of the 17 correlations between Desired Control and a variety of measures of psychological adjustment reported across the four studies were significant and sizeable (mean r = .44). Social Desirability responding had negligible effects on correlations. Furthermore, five of seven correlations between Desired Control measured at one time and Psychological Adjustment measured 12 months later were significant (mean correlation = .46). Consistent with theoretical expectations, Expectancy scores were stronger predictors of well-being than were desire scores. The results of these studies gave support for the supposition that personal control is an important variable in psychological adjustment among the elderly.

Adaptation, Psychological↗

Transcriptional and translational control of glucose-stimulated (pro)insulin biosynthesis.

Islets of Langerhans were isolated from the pancreata of fed or 48-h-fasted Wistar rats. The islets were incubated with either [3H]leucine of [3H]uridine. Inhibition of RNA synthesis by actinomycin D or by alpha-amanitin for 4 h had no influence on the (pro)insulin biosynthesis of isolated islets of fed rats. The (pro)insulin biosynthesis was not inhibited after two days incubation of islets of fed rats with alpha-amanitin either. Incorporation of labelled uridine into total RNA for 3 h was stimulated by glucose in islets of fasted, but not of fed rats. Therefore, it was concluded that transcriptional control does not participate, even for longer periods than believed previously, in acute regulation of (pro)insulin biosynthesis of islets isolated fed rats. Despite the strong and preferential stimulation of (pro)insulin biosynthesis of islets of fed rats by glucose the radioactivity of the [3H]uridine-labelled polysomes active in proinsulin synthesis remained unchanged. To interprete these experimental data we suggest that glucose triggers the transformation of a translationally inactive form of pre-proinsulin mRNA to a translationally active form.

Amanitins↗

[Radioligand assay: method and application. II. Effect of glucagon coupling on the production of glucagon antisera with suitable binding parameters for radioimmunoassay].

Glucagon antibodies were produced in rabbits using three immunogenic glucagon conjugates. Glucagon was coupled to bovine serum albumin by difluorodinitrobenzene (DFDNB), carbodiimide (ECDI) or glutardialdehyde. Rabbits immunized with glucagon conjugated to albumin using DFDNB produced sensitive antisera for radioimmunoassay quite specific for pancreatic glucagon. The affinity constant of the best antiserum was approximately 10(11) l/mol. Antisera raised against the two other glucagon-conjugates were significantly less affine. All of these antisera showed inverse binding curves of 126J-glucagon caused by positive cooperatively in dependence upon the antigen/antibody ratio. The race of rabbits used for immunization was without influence on the immune response.

Animals↗

[Radioligand assay: methods and application. V. Mono-125I-insulin: preparation and immunological and biological characterization].

A reproducible method for preparation of 125I-monoiodoinsulin with fully biological activity was developed. Monoiodoinsulin has been prepared from a heterogeneous 125I-iodination mixture by anion exchange chromatography on DEAE-Sephadex A-25 without using any gradient elution technique. The specific radioactivity of 125I-monoiodoinsulin was calculated to 14.3 +/- 0.8 TBq/g, i.e. an iodine content of 1.04 +/- 0.06 atoms per molecule of insulin. Monoiodoinsulin was indistinguishable from native insulin with respect to binding to guinea pig anti-insulin serum, and to insulin receptors of isolated rat adipocytes. The biological potency (96.5 +/- 7.5 per cent of the immunoreactive insulin activity) determined by the conversion of [14C1]-D-glucose to 14CO2 in vitro by rat fat cells was not significantly different from that of native insulin.

Animals↗

Electrolytes and norepinephrine levels in blood of patients with cystic fibrosis.

Young adults with cystic fibrosis in good to excellent condition have reduced plasma sodium and chloride and elevated plasma potassium compared to a group of healthy young adult control subjects. Blood pressure was also lower in the patients with cystic fibrosis. However, plasma norepinephrine and dopamine-beta-hydroxylase and their response to standing and isometric hand grip were normal in the cystic fibrosis patients.

Adolescent↗

[Clinical efficacy, nephrotoxicity and ototoxicity of amikacin].

The clinical efficacy and toleration of amikacin was investigated in 22 patients most of whom had chronic urinary tract infections that had already been treated unsuccessfully on several occasions with other antibiotics. Amikacin was administered i.m. in a dosage of 7.5 mg per kg twice daily for an average of 11.4 days. This new aminoglycoside antibiotic proved highly effective in the treatment of chronic pyelonephritis and cystitis, as well as in septicaemia caused by gentamicin-resistant Pseudomonas. The pharmacokinetic studies did not show any retention after a ten day treatment with amikacin. Thorough nephrologic and otologic investigations for side-effects did not show any permanent nephrotoxic or ototoxic damage or delayed damage. The results were compared with the clinical and experimental data in the literature and with the results of experimental studies which have not yet been published.

Adult↗