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S Ritter

Publications and source records attributed to S Ritter.

154 records · Page 9Linked to original sources

Intraventricular glucose blocks feeding induced by 2-deoxy-D-glucose but not mercaptoacetate.

Previous results have shown that IV infusion of glucose reduces feeding induced by systemic administration of 2-deoxy-D-glucose (2-DG) or 2-mercaptoacetate (MA) in rats. Because glucose is a metabolic substrate for both central and peripheral tissues, the suppression of feeding by glucose could result from either a central or peripheral metabolic effect. In the present experiment we attempted to clarify the mechanism of glucose-induced suppression of feeding induced by 2-DG and MA by administering glucose centrally during systemic metabolic challenge. Administration of glucose into the lateral ventricle was begun immediately after systemic injection of 2-DG or MA and continued intermittently during the 2-h feeding test. We found that central glucose administration significantly reduced 2-DG- but not MA-induced feeding. These results suggest that the central effects of glucose are sufficient to suppress feeding induced by systemic 2-DG and support the hypothesis that receptors responsible for 2-DG-induced feeding are located in the brain.

Animals↗

Nodose ganglionectomy reduces angiotensin II receptor binding in the rat brainstem.

Angiotensin II (Ang II) receptor binding sites in the dorsomedial medulla of intact and unilaterally nodose ganglionectomized rats were identified and characterized using 125I-sarcosine,isoleucine Ang II. This radioligand bound saturably and with high affinity to rat brain homogenates and to sections of rat brainstem. Specific (1 microM angiotensin II displaceable) binding of 125I-sarcosine,isoleucine Ang II was displaced by angiotensin analogues with a potency order similar to that described for angiotensin II receptors. Unilateral nodose ganglionectomy caused a reduction in Ang II receptor binding in the medial solitary tract nucleus, dorsal motor nucleus of the vagus, and area postrema ipsilateral to the lesioned ganglion. This observation suggests that Ang II receptors in the dorsomedial medulla may be located on axon terminals of vagal afferents and cell bodies of vagal efferents.

Angiotensin II↗

[Prenatal diagnosis of hepatic hemangioendothelioma and peripartual management].

Infantile hepatic hemangioendothelioma is a benign hepatic tumor that can be associated with life-threatening perinatal complications. A 38-year-old gravida 3 para 2 was referred to our hospital with preterm labor at 33.6 gestational weeks. Fetal abdominal circumference was estimated sonographically above the 97 th percentile. Because of pathologic CTG, the fetus was delivered by caesarean section (APGAR-scores 0/0/7, pH: 7.15). After cardiopulmonary reanimation and intensive care of the fetus, the prenatally suspected hemangioma of the liver was confirmed by computer tomography. The day after, liver segments V, VI, and VII were resected because of lung compression. During the operation, reanimation was necessary two more times. Two days later, ductus arteriosus Botalli was occluded. After stabilization, the neonate was treated with prednisone because of tumor residues. If a large hyperechogenic mass in the fetal liver is seen prenatally, diagnosis of fetal hemangioma should be considered. In order to prevent serious cardiovascular complications, continual clinical surveillance is indicated.

Adult↗

[Quantitative evaluation of the dynamics of tubercular mediastinal adenopathy treated with rifampicin and ethambutol].

The authors have followed for one year the rhythm of involution of adenopathy in 114 patients aged between 0 and 16 years, with patent primary infection, in which four therapeutic regimens have been randomly applied, in continuous or intermittent administration, with INH-RMP; RMP-EMB; INH-EMB; INH-SM. Quantified data were obtained with the aid of a planimeter, measuring the surface of the adenopathy on trimestrial seriotomographies. The rhythm of involution was evaluated by the variable halving time of the surface of the adenopathy under treatment. The percentage, the data of the physical model, showed that in the first 3--4 months, detection of the curves is more rapid for RMP and the 7/7 formula, but with almost similar results (8--14%) at 12 months. By processing the data in the computer, depending on the mathematical model, it was estimated that the halving time is by 90,4 days shorter for RMP and similar for EMB and SM.

Adolescent↗

[Statistico-mathematical appraisal of the length of the pretherapeutic interval in the prognosis of tubercular meningitis in children].

The data obtained concerning the two main parameters for the prognosis of tuberculous meningitis: onset-admission interval, assessed anamnestically and electtoencephalogram performed on admission, were processed mathematically by computer. The EEG is a more reliable parameter for assessing the gravity of the lesions on admission that the anammestic data regarding the onset, at a signficance threshold of 10.48% as against 5.23%. For 11.3 days there was a close correspondence between the two parameters, after which the onset-admission variable became aleatory, the only objective index of gravity being the EEG. Statistico-mathematical processing increases the objectivity and precision of the prognosis.

Adolescent↗

Mental health. The nurse's support role.

The role of the nurse in the management and treatment of manic depression comprises social, psychological and pharmacological interventions. Achieving a balance is crucial to the management of this serious disorder and nurses are ideally placed to help in this.

Adaptation, Psychological↗

A new formalin test allowing simultaneous evaluation of cardiovascular and nociceptive responses.

The formalin test for nociception, predominantly used with rodents, is characterized by continuous pain due to tissue injury induced by formalin. In addition to the pain generated by formalin itself, the classical formalin test for nociception comprises a number of additional strong stressful events such as restraint and injury caused by needle insertion. These events have hampered its use as a model of stress employing continuous pain as a stress stimulus. We describe here a new, simple method of a subcutaneous application of formalin in conscious rats without restraint and needle insertion. Formalin or physiological saline (controls) was injected subcutaneously through a chronically implanted catheter in the region of the lower leg. In most animals, the cardiovascular and behavioural responses to subcutaneously injected formalin were biphasic. The early phase was quantitatively characterized. Formalin (2.5%, 50 microL) induced a marked increase in mean arterial pressure and heart rate. Maximal increases occurred during the first 3 min after formalin injection and were followed by a gradual decline of both cardiovascular parameters to levels higher than the preinjection baseline. Subcutaneous saline injection did not induce any changes in mean arterial pressure and heart rate. The behavioural response to formalin featured intensive licking and biting of the injection site. The behavioural response to subcutaneous saline did not differ from the spontaneous behavioural activity recorded in noninjected rats. Subcutaneously injected formalin induced an immediate increase in plasma corticotrophin (ACTH), corticosterone, noradrenaline, and adrenaline levels, and all hormones remained increased during the whole observation period (60 min). Adrenaline and noradrenaline levels in plasma were slightly, but significantly, elevated during the initial 5 min after subcutaneous saline application but returned to basal values after 15 min. The magnitude of the hormonal responses characterizes the described formalin test as a moderate stress stimulus. The complex response pattern to formalin injected through the subcutaneous catheter is brought about exclusively by pain generated by formalin-induced tissue injury. The described technique of subcutaneous formalin injection represents a new tool to study mechanisms activating brain neuronal circuits that generate the cardiovascular, endocrine, and behavioural responses of the reaction to pain.

Animals↗