Immune function did not decline with aging in apparently healthy, well-nourished women

Nutrition plays a crucial role in immune function. Most studies on age-associated changes in immunocompetence in healthy adults did not examine the nutritional status of participants extensively. Inadequate nutritional status may confound the relationship of aging and immune response. The purpose of this study was to examine age-related changes in parameters of acquired and innate immunity in healthy and generally well-nourished older (62-88 years) versus younger (20-40 years) women. Subjects were screened for participation using the health criteria of the SENIEUR protocol as well as a number of nutrition criteria related to undernutrition, and protein, iron, vitamin B12, and folate status. Young and old women did not differ in total T (CD3+), T-helper (CD4+), or T-cytotoxic (CD8+) cell number. However, older women tended to have lower T-cell proliferation response to concanavalin A (P < 0.10) and significantly reduced response to phytohemagglutinin (P < 0.05). No age-related changes were noted in natural killer cell number or cytotoxicity. Phagocytosis and subsequent oxidative burst activity also did not differ between young and old women. Most immune parameters were not compromised with aging in this cohort of apparently healthy, well-nourished women. These findings highlight the importance of simultaneous examination of health and nutritional status in studies of immune function with aging.     

Selective inhibition of the transmembrane Ca conductivity of mammalian myocardial fibres by Ni,Co and Mn ions

Pflügers Archiv - European Journal of Physiology - According to earlier studies on mammalian papillary muscles, Ni and Co ions reduce the Ca dependent mechanical response whilst the action...     

Kinetic fluorescence RT-PCR is highly sensitive for detection of germ-cell-tumor-specific transcripts in peripheral blood

The aim of our study was to determine whether conventional staging in patients with testicular germ-cell-tumors (GCT) could be supplemented by quantification of beta-human choriogonadotropin mRNA levels in peripheral blood using kinetic fluorescence RT-PCR. Blood samples from 41 patients with GCT of different clinical stages (CS) were pre-therapeutically examined by kinetic fluorescence RT-PCR with the LightCycler for beta-human chorionic gonadotropin (beta-HCG) mRNA expression levels. The controls comprised of samples taken from patients 3 months after treatment, from patients with inflammatory testicular diseases or non-germ-cell-tumors and from healthy males (n=66). Six positive results [cut-off level: normalized beta-HCG mRNA (Nbeta-HCG) >400 relative gene expression (RGE)] were found in controls (specificity 90.9%, 95% CI: 76.9-97.3%). The overall ratio of positive PCR results in the group of GCT patients was 82.92% (34/41) (CS I 18/23, CS IIa-b 6/7, CS >IIb 10/11) (sensitivity 82.9%, 95% CI: 65.1-91.2%). The average Nbeta-HCG level in patients with clinical stage I tumors was 63772.0+/-125720.5 (mean +/- standard deviation) relative gene expression (RGE), 35076.0+/-52253.5 RGE in those with CS IIa-b tumors and 87298.3+/-120895.3 RGE in those with CS >IIb tumors. Kinetic fluorescence RT-PCR for tumor-specific gene products is, in contrast to qualitative RT-PCR, a promising approach to improve conventional staging in clinical low-stage testicular germ-cell-tumors. With high specificity, its sensitivity is higher than that of the corresponding serum tumor marker (82.92% vs 48.72%).     

Endogenous brain angiotensin II disrupts passive avoidance behavior in rats

The presence of angiotensinogen, the precursor of angiotensin II (ANG II), in brain tissue and in cerebrospinal fluid (CSF) allows stimulation of endogenous brain ANG II by renin. Passive avoidance tests were performed in female Wistar rats. The animals received an electrical shock after entering a black box on the first experimental day. Avoidance was tested every 24 h for 5 consecutive days. Renin in doses of 0.01 and 0.1 units was injected once into the lateral brain ventricles 2 min before the first test. CSF ANG II increased from 40 to 4547 and 5152 fmol per ml (means), respectively. A dose-dependent disruption of avoidance learning was observed, the frequency to enter the black box increasing from 11% (control) to 29% and 46%, and the latency decreasing from 165 (control) to 143 and 116 sec, respectively. These effects were statistically significant (P less than 0.001) for more than 24 h and returned to control levels after 48 to 120 h. Administration of the converting-enzyme inhibitor SQ 14225 i.v.t. prior to renin injections abolished the renin effects. Injections of renin given 22 h after learning were without effect.     

Vasomotorik der Hirnrinde und EEG-Aktivität wacher,frei beweglicher Katzen

Zusammenfassung Zur Untersuchung von Vasomotorik und EEG der Großhirnrinde wurde ein Verfahren ausgearbeitet, das die Messungen an unnarkotisierten, frei beweglichen Katzen zuläßt und somit eine gleichzeitige Beurteilung der Verhaltensweisen der Tiere ermöglicht.Ein Meßelement zur lokalen Messung der Durchblutung, EEG-Elektroden sowie Katheter für die Messung des arteriellen Druckes und für i.v. Injektionen wurden in Halothane-Stickoxydul-Narkose implantiert. Die Messungen wurden im allgemeinen innerhalb 48 Std nach der Operation vorgenommen, wobei sich das Tier in einer geschlossenen Kammer befand.In den Versuchen hat sich zunächst gezeigt, daß die Durchblutung der Hirnrinde rhythmische Schwankungen aufweist, die in der Regel in einem — über längere Zeit konstanten oder auch häufig wechselnden — geradzahligen Verhältnis zur Atmung von 1:2 bis etwa 1:10 stehen.Das Ergebnis früherer Untersuchungen an narkotisierten Hunden, daß keine feste Korrelation zwischen EEG-Aktivität und Vasomotorik der Hirnrinde besteht, wurde bestätigt. Eine Desynchronisierung des EEG kann mit einer Dilatation oder auch ohne Gefäßreaktion ablaufen. Eine Gefäßreaktion scheint nur dann aufzutreten, wenn auch eine deutliche Reaktion im Gesamtverhalten des Tieres auftritt.Während desynchronisierter EEG-Aktivität gegebene sensible Reize können ebenfalls zu einer Dilatation der corticalen Gefäße führen. Das Ausmaß der Vasodilatation scheint dabei dem der Verhaltensreaktion parallel zu gehen.Mit 6 TextabbildungenMit Unterstützung durch die Deutsche Forschungsgemeinschaft.     

The mammalian testis-specific thioredoxin system

Redox control of cell physiology is one of the most important regulatory mechanisms in all living organisms. The thioredoxin system, composed of thioredoxin and thioredoxin reductase, has emerged as a key player in cellular redox-mediated reactions. For many years, only one thioredoxin system had been described in higher organisms, ubiquitously expressed in the cytoplasm of eukaryotic cells. However, during the last decade, we and others have identified and characterized novel thioredoxin systems with unique properties, such as organelle-specific localization in mitochondria or endoplasmic reticulum, tissue-specific distribution mostly in the testis, and features novel for thioredoxins, such as microtubule-binding properties. In this review, we will focus on the mammalian testis-specific thioredoxin system that comprises three thioredoxins exclusively expressed in spermatids (named Sptrx-1, Sptrx-2, and Sptrx-3) and an additional thioredoxin highly expressed in testis, but also present in lung and other ciliated tissues (Txl-2). The implications of these findings in the context of male fertility and testicular cancer, as well as evolutionary aspects, will be discussed.     

Evaluation of the clonidine-suppression test in the diagnosis of pheochromocytoma

Summary In this study we examined the preoperative value of the clonidine-suppression test in 15 patients with surgically proved pheochromocytomas. The result of the clonidine-suppression test was pathological (epinephrine plus norepinephrine above 500 ng/l 3 h after clonidine) in 10 of 15 patients (66%). These patients had relatively large tumors and higher basal norepinephrine plasma levels. Out of the 5 cases without a pathological clonidine test 4 had normal basal plasma catecholamine levels with the result that the clonidine test could not be properly applied and 1 case produced a false negative result. These 5 cases generally had smaller tumors and lower plasma catecholamine levels. Two of these cases had basally raised epinephrine values. The other three cases had either a paradoxical increase or a suspiciously low fall (less than 25%) in norepinephrine within the normal range. We conclude that the clonidine-suppression test is only reliable for the diagnosis of relatively large pheochromocytomas.Abbreviations MIBG metaiodobenzylguanidine - HPLC High-performance liquid chromatography     

Kinetics of inactivation and recovery of the slow inward current in the mammalian ventricular myocardium

In order to study the kinetics of inactivation and recovery of the slow inward current in the mammalian ventricular myocardium voltage clamp experiments using the double sucrose gap technique were performed on isolated trabeculae and papillary muscles of cats. The separation of the slow inward current from the fast Na current was achieved by use of the conditioning clamp procedure. 1. The decay of the Ca current reflects the inactivation which develops due to depolarization. The rate of inactivation depends upon the membrane potential. Excess Ca (8.8 mM) accelerates the inactivation speed indicating that Ca ions not only act as charge carrier of the slow inward current but might influence in addition the kinetics of the slow membrane channel. In the presence of a lowered temperature a deceleration of inactivation (Q10 2.3) occurs. 2 If the membrane is repolarized a recovery process takes place restoring the availability of the slow membrane channel. As the inactivation the recovery rate depends upon the membrane potential. Excess Ca causes an acceleration whereas a decrease in temperature diminishes the recovery speed (Q10 2.3). Consequently, the Ca supply to the myocardial cell can be modified not only by changes of the transmembrane Ca concentration gradient or by an alteration of the Ca conductance of the slow channel but also by changes in the degree of recovery after a preceding Ca current. 3. Compared with the inactivation the recovery proceeds very slowly. Assuming that this slow recovery represents an inherent kinetic feature of the slow channel the kinetics of inactivation and removal of inactivation are not describable by a single inactivation variable (called as f by Reuter, 1973) which is of the Hodgkin-Huxley type. If a second inactivation variable (called as l) would be introduced additionally a formulation of the inactivation-recovery process of the slow membrane channel on the basis of the Hodgkin-Huxley model becomes feasible.     

Glossitis in the area supplied by the chorda tympani nerve in peripheral facial paralysis. Early symptom of the Melkersson-Rosenthal syndrome?

The case is reported of a patient with incomplete peripheral facial palsy. In addition to hyperacousia and gustation disturbance, he presented with signs of glossitis limited to the region supplied by the chorda tympani. Clinical and laboratory investigations excluded the possibility of a viral infection. Possible connections between this combination of symptoms (apparently "idiopathic" facial palsy and regional glossitis) and the Melkersson-Rosenthal syndrome are discussed.