The long term acute phase-like responses that follow acute stressor exposure are blocked by alpha-melanocyte stimulating hormone

Both intracerebroventricular (i.c.v.) IL-1β and exposure to inescapable tail shock (IS) activate acute phase responses (APRs) that include increases in core body temperature (CBT), increases in hypothalamic–pituitary–adrenal activity, decreases in carrier proteins such as corticosterone binding globulin (CBG), aphagia and adipsia. A variety of data suggested that stressors produce APRs by inducing brain IL-1β. The current series of studies further explored this possibility by determining whether the functional IL-1β antagonist, -melanocyte-stimulating hormone (-MSH_(1–13)), would block IS-induced APRs. Immediately following i.c.v. -MSH_(1–13) administration, rats were exposed to a single session of 100, 5 s, 1.6 mA ISs, or control treatment (home cage control). -MSH_(1–13) blocked IS-induced increased CBT, increased plasma corticosterone (CORT), decreased CBG, aphagia and adipsia 24 h after IS. The inhibitory effects of -MSH_(1–13) were shown not to be a consequence of -MSH_(1–13) producing its actions 24 h after its administration because -MSH_(1–13) given 24 h before IS did not block IS-induced increased CBT and CORT during IS. Additionally, -MSH_(1–13), given 24 h before IS, had no effect on increased CBT, increased CORT, decreased CBG, adipsia, or aphagia 24 h after IS. These data provide support for a specific mode of action for i.c.v. -MSH_(1–13), namely blockade of APRs with no impact on acute hyperthermia or increased levels of CORT produced during IS.     

Influence of the flavonoid (+)-catechin on the permeability of Ehrlich mouse ascites tumour cell membranes

Summary The effect of the flavonoid (+)-catechin and its hydrophilic derivative epicatechinsulphonate on the permeability of Ehrlich mouse ascites tumour cells (EMAT) was investigated. As a sensitive assay, the transmembrane fluxes of two different solutes were measured, the inwardly directed free diffusion of ¹⁴C-thiourea, and the carrier-mediated efflux of intracellularly accumulated ¹⁴C-1-aminocyclopentane-1-carboxylic acid.(+)-Catechin was found to reduce the permeability of EMAT membranes for both solutes. The primary target of the drug appears to be the membrane itself. The effectiveness of the drug was dependent on its concentration. Inhibition of fluxes was observed at 0.86 mM; the inhibition gradually increased as the concentration was increased. In contrast to (+)-catechin, epicatechinsulphonate was rather ineffective, even at a concentration as large as 10 mM. The effect of (+)-catechin was seen within a few minutes after its addition. However, it was considerably intensified as the incubation was prolonged. The effectivity of (+)-catechin decreased with increasing cell density. Thus, the drug appears to be adsorbed by the cells.From the various data and the observation that incorporation of a strong lipophobic sulphonate residue into the moderately lipophilic catechin molecule markedly lowers the effectivity of the flavonoid, it is concluded that (+)-catechin, as a membrane stabilizing drug, interacts directly with certain constituents, of the cell envelope, presumably membrane lipids.     

Extraskeletal Ewing''s Sarcoma of the Scalp

A 15-year-old boy had an extraskeletal Ewing's sarcoma arising in the soft tissues of the scalp. The tumor was rapidly growing, subcutaneous mass unattached to the underlying bony structures. Histologic examination revealed a proliferation of primitive-appearing, round to oval cells adopting a lobular configuration. Immunohistochemical studies confirmed the undifferentiated mesenchymal nature of the neoplasm.     

Stability of enzymes in urine at 37°C

The activity of alanine aminopeptidase, alkaline phosphatase, γ-gluta-myltransferase, lactate dehydrogenase and β-$\text{N-}\text{acetyl}\text{-}\text{d}\text{-}\text{glucosaminidase}$ in urine at 37°C was investigated by a model simulating in vivo conditions.The stability of these urinary enzymes is influenced particularly by pH. At low pH values in urine (about pH 5.0) the four first-mentioned enzymes rapidly lose a considerable part of their activity, whereas β-$\text{N-}\text{acetyl}\text{-}\text{d}\text{-}\text{glucosaminidase}$ is inactivated at higher pH values in urine (about at pH 8.0).This inactivation effect is also time-dependent and can be modified by urinary substances such as creatinine, urea and electrolytes. To avoid misinterpretation of enzyme activity determinations in urine, the simultaneous measurement of urinary pH should be performed.     

Analyse der Herzfrequenzvariabilität Grundlagen,Methodik und mögliche Anwendungen in der Anästhesie

Background and methods. Small, periodic fluctuations in heart rate are well known to physicians, the respiratory sinus arrhythmia (RSA) being the most easily detectable form of this heart rate variability (HRV). Since it is caused by changing activity of the autonomic nervous system (ANS) controlling heart rate, HRV is investigated to gain information on the functional states of the ANS. Recent developments have led to computer-aided processing of EKG signals based on time and frequency domain methods – the latter using power spectral analysis by fast Fourier or autoregressive algorithms – to exactly describe and quantify HRV. Three major regions in the frequency spectrum between 0.03 and 0.5?Hz (the suitable range for short-term recordings) have been established: (1) a region around the respiratory rate, usually between 0.2 and 0.35?Hz, called high frequency (HF), (2) a region around 0.1?Hz attributed to vasomotor activity feedback, called low (or mid-) frequency (LF), (3) a peak around 0.04–0.05?Hz correlated to thermoregulation, called very low (or low)frequency (VLF). Power spectral density of HRV is now commonly accetped as a measure of autonomic cardiovascular control activity. By studies on vagal or sympathetic blockade, the HF (or RSA) region has been attributed solely to vagal activity, while both parts of the ANS may contribute to the other two, with, however, the vagal part predominating the resting, healthy individuals. Clinical applications/anaesthesia. Thus, spectral analysis of HRV provides a measure for quantifying sympatho-vagal balance in its physiological range. Additionally, reduction of HRV along with cardiovascular disease, including hypertension, myocardial infarction, heart failure and sudden cardiac death, as well as with autonomic dysregulation, has been reported. Since is also a striking reduction produced by most anaesthetic agents, RSA and HRV are investigated as measures of anaesthetic depth. There are contradictory data on the influence of ventilation, medication, and co-existing disease on the spectrum, and thus validation of the method is still to be achieved. It has, however, been proven useful in some studies as a parameter for risk assessment of perioperative or post-infarction cardiovascular complications.