Serum concentration of S-100 protein in assessment of cognitive dysfunction after general anesthesia in different types of surgery.

BACKGROUND: S-100 protein serum concentration (S-100) serves as a marker of cerebral ischemia in cardiac surgery, head injury and stroke. In these circumstances S-100 corresponds well with the results of neuropsychological tests. The aim of the present study was to investigate the value of S-100 and neuron specific enolase (NSE) in reflecting postoperative cognitive deficit (POCD) after general surgical procedures. METHODS: One hundred and twenty patients undergoing vascular, trauma, urological or abdominal surgery were investigated. Serum values of S-100 and NSE were determined preoperatively and 0.5, 4, 18 and 36 h postoperatively. Neuropsychological tests for detecting POCD were performed preoperatively and on day 1, 3, and 6 after the operation. A decline of more than 10% in neuropsychological test results was regarded as POCD. Furthermore, we retrospectively compared the S-100 in patients with and without POCD in different types of surgery. RESULTS: According to our definition, forty-eight patients had POCD (95% confidence interval: 37.5-58.5). These patients showed higher serum concentrations of S-100 (median 024 ng/ml; range 0.01-3.3 ng/ml) compared with those without POCD (n=69; median 0.14 ng/ml; range 0-1.34 ng/ml) 30 min postoperatively (P=0.01). Neuron specific enolase was unchanged during the course of the study. Differences of S-100 in patients with and without POCD were found in abdominal and vascular surgery but not in urological surgery. CONCLUSION: When all patients are pooled, S-100 appears to be suitable in the assessment of incidence, course and outcome of cognitive deficits. We suspect that in some surgical procedures, such as urological surgery, S-100 appears to be of limited value in detecting POCD. Neuron specific enolase did not reflect neuropsychological dysfunction after noncardiac surgery.

Specific inhibition of phorbol ester-stimulated phospholipase D by Clostridium sordellii lethal toxin and Clostridium difficile toxin B-1470 in HEK-293 cells. Restoration by Ral GTPases.

Activation of m3 muscarinic acetylcholine receptor (mAChR), stably expressed in human embryonic kidney (HEK)-293 cells, leads to phospholipase D (PLD) stimulation, a process apparently involving Rho GTPases, as shown by studies with Clostridium botulinum C3 exoenzyme and Clostridium difficile toxin B (TcdB). Direct activation of protein kinase C (PKC) by phorbol esters, such as phorbol 12-myristate 13-acetate (PMA), also induces PLD stimulation, which is additive to the mAChR action and which is only poorly sensitive to inactivation of Rho proteins by TcdB. To study whether Ras-like GTPases are involved in PLD regulation, we studied the effects of the TcdB variant TcdB-1470 and Clostridium sordellii lethal toxin (TcsL), known to inactivate Rac and some members of the Ras protein family, on PLD activities. TcdB-1470 and TcsL did not affect basal PLD activity and PLD stimulation by mAChR or direct G protein activation. In contrast, PMA-induced PLD stimulation was inhibited by TcdB-1470 and TcsL in a time- and concentration-dependent manner, without alteration in immunologically detectable PKC isozyme levels. In membranes of HEK-293 cells pretreated with TcdB-1470 or TcsL, basal and stable GTP analog-stimulated PLD activities measured with exogenous phosphatidylcholine, in the presence or absence of phosphatidylinositol 4,5-bisphosphate, were not altered. In contrast, pretreatment with TcdB-1470 and TcsL, but not TcdB, strongly reduced PMA-stimulated PLD activity. The addition of recombinant Rac1, serving as glucosylation substrate for TcdB, TcsL, and TcdB-1470, did not restore PLD stimulation by PMA. Furthermore, PMA-stimulated PLD activity, suppressed by prior treatment with TcdB-1470 or TcsL, was not rescued by the addition of recombinant Ras (RasG12V) or Rap proteins, acting as glucosylation substrates for TcsL only (Ras) or TcdB-1470 and TcsL (Rap). In contrast, the addition of recombinant Ral proteins (RalA and RalB), glucosylation substrates for TscL and TcdB-1470, but not for TcdB, to membranes of TcdB-1470- or TcsL-treated cells fully restored PLD stimulation by PMA without altering the strict MgATP dependence of PMA-induced PLD stimulation. RalA-mediated restoration of PMA-stimulated PLD activity in membranes of TcsL-treated cells was not enhanced by coaddition of RasG12V. In conclusion, the data presented indicate that TcdB-1470 and TcsL selectively interfere with phorbol ester stimulation of PLD and suggest an essential role of Ral proteins in PKC signaling to PLD in HEK-293 cells.

Characteristics of protein-kinase-C- and ADP-ribosylation-factor-stimulated phospholipase D activities in human embryonic kidney cells.

Phospholipase D (PLD) activity in human embryonic kidney (HEK) cells is stimulated by phorbol-ester-activated protein kinase C (PKC) and by membrane receptors, the latter apparently acting via the GTP-binding proteins, ADP-ribosylation factor (ARF) and Rho. In the present study, performed in cell-free preparations, we have characterized and compared the regulation of HEK cell PLD activity by the stable GTP analogue, guanosine 5'-O-[gamma-thio]triphosphate (GTP[S]), and the phorbol ester, phorbol 12-myristate 13-acetate (PMA). In digitonin-permeabilized HEK cells, prelabeled with [3H]oleic acid, GTP[S] and PMA caused an approximately threefold concentration-dependent increase in the formation of [3H]phosphatidylethanol, measured in the presence of ethanol. Neomycin, which is known to complex with the PLD cofactor, phosphatidylinositol 4,5-bisphosphate, decreased basal and GTP[S]- or PMA-stimulated PLD activities with similar sensitivity. GDP and its analogue, guanosine 5'-O-[beta-thio]diphosphate, inhibited the stimulatory effect of GTP[S], whereas the PMA response was prevented by the nonselective PKC inhibitor, staurosporine, but not vice versa. PLD stimulation by GTP[S], but not by PMA, was markedly reduced upon cytosol depletion and reconstituted by purified recombinant ARF1. In HEK cell membranes, addition of purified recombinant ARNO, a guanine-nucleotide-exchange factor for ARF1. potentiated the GTP[S]-stimulated PLD activity. PLD stimulation by PMA in HEK cell membranes required MgATP and was largely prevented by the selective PKC inhibitors Goe 6976 and bisindolylmaleimide I. Immunoblot analysis demonstrated that both conventional PKC (alpha, beta, gamma) and atypical PKC isozymes (zeta, tau) were present in HEK cell membranes. The results indicate that phorbol ester stimulation of PLD activity in HEK cells apparently occurs by a phosphorylation-dependent mechanism involving membrane-associated PKC isozymes but not ARF proteins, the major targets of GTP[S]' action.

Cardioprotective potency of the radical scavenger S-2-(3 aminopropylamino) ethylphosphorothioic acid in the post-ischaemic rat heart.

S-2-(3 aminopropylamino) ethylphosphorothioic acid (WR-2721) shown to surpass radical scavenging thiols in their radioprotective efficacy in cancer-type diseases has been tested for its protective potential in the reperfused heart. We investigated the radical scavenger properties of the compound in a radical generating system in vitro as well as in isolated rat hearts subjected to 30 min ischaemia and 30 min reperfusion with the electron-paramagnetic resonance spin trap technique. The action on high-energy phosphates is observed by means of phosphorus-31 nuclear magnetic resonance (NMR) spectroscopy while its influence on left ventricular systolic segmental length change (SSLC) during 60 min reperfusion following 60 min regional ischaemia was assessed with a fibreoptic system in anaesthetized open-chest rats. WR-2721 (0.1 mM) reduced the vascular concentration of radical adduct in isolated hearts by up to 78% (275 +/- 84% of pre-ischaemic baseline values vs 1260 +/- 413%, p < 0.05) between 5 and 12.5 min reperfusion. This was accompanied by a reduction of the left ventricular end diastolic pressure to pre-ischaemic values at 30 min of reperfusion (9 +/- 6 mmHg vs 42 +/- 8 mmHg in the absence of WR-2721, p < 0.02). An accelerated recovery of creatine phosphate levels (78 +/- 5% of pre-ischaemia values vs 41 +/- 5% within 60 min reperfusion: p < 0.05) was observed under similar conditions with NMR-spectroscopy, although the post-ischaemic tissue content of adenosine triphosphate was not affected.(ABSTRACT TRUNCATED AT 250 WORDS)

Improved contractile function in the reperfused rat heart by the radical scavenger 2-[3-aminopropylamino] ethane thiol.

The action of the radioprotector WR 10 65 on regional function of the left ventricular muscle in ischemic injured and reperfused rat heart was investigated employing a new fiber optic based method for determination of segment shortening. In anesthetized rats exposed to regional myocardial ischemia by ligation of the left anterior descending coronary artery for 60 minutes followed by 60 minutes of reperfusion WR 10 65 applicated in a dosage of 1 mM/kg body weight intraperitoneally 30 minutes prior to ischemia induced an improvement of post ischemic recovery of segment shortening from 31% of pre-ischemic values in untreated animals to 64.6%. Because only moderate alterations in global functional parameters compared to control group were found in WR 10 65 treated animals, it is presumed that the observed influence on regional myocardial function is less due to changes in cardiac load than to the radical scavenger activity of the tested agent. A possible contribution of hypoxic and hypocalcemic activity of the substance remains to elucidate.

Pineal gland in rats suffering from malignancy.

Studies of the pineal gland in rats suffering from fibrosarcomas induced by 9, 10-dimethyl-1, 2-benzanthracene have been carried out. The weight of the pineal gland in these animals did not differ from that in control animals. However, the cells and their nuclei in the pineal glands of tumour bearing animals were larger and contained more lipid than those in the pineal glands of control animals. The results indicate that there is increased metabolic activity in the pineal glands of tumour bearing animals.

The human pineal gland in malignancy.

The weight and degree of calcification of 500 pineal glands has been measured. The degree of cellularity, the size of the pineocyte nuclei and the extent of degeneration has been estimated in histological examinations of the glands. There are some differences in the weight of the gland in males and females of different ages and part of this is due to variations in the amount of calcium in the glands. There is only a minor decrease in the cellularity of the glands with increasing age, and this is accompanied in females by a slight increase in fibrosis and gliosis. The weight of the gland is high in patients dying from trauma and burns. No statistical differences are found in the weight of the pineal glands from patients dying of malignant and non-malignant conditions, although in most age-groups the glands tend to be smaller in patients dying of malignancy. On the other hand patients dying from carcinoma of the breast and from melanoma have much larger glands than those dying from sarcoma.

Radioimmunoassay for melatonin.

A radioimmunoassay for melatonin has been developed and used to measure the level of melatonin of male and post-menopausal female patinets coming to operation for benign and malignant conditions. The amount of melatonin in the serum of the females was considerably lower than that in males. No difference could be found between patients suffering from benign and malignant conditions. A patient with a non-parenchymatous pineal tumour had considerably lower levels in the serum at three months after surgery and radiotherapy. A further month later melatonin could not be found in samples of serum taken over a 24-hour period.

HBsAg and HBcAg in the livers of asymptomatic hepatitis B antigen carriers.

Asymptomatic blood donors with persistent HBs antigenaemia have a variety of histological lesions in the liver, and serial biopsies indicate that, in some, these lesions may progress. The immunoperoxidase technique was found to be a sensitive method for the histological demonstration of HBsAg and HBcAg. Livers showing minor histological changes contained more HBsAg than those with active lesions and there appears to be an inverse relationship between the amount of HBsAg in the liver and the severity of the histological damage. In the carriers who had more than one biopsy, the presence of stainable HBsAg, irrespective of the initial histological diagnosis, was associated with a greater likelihood of progression of the histological lesion. HBcAg was found only in the hepatocyte nuclei of carriers with chronic aggressive and chronic persistent hepatitis.

Serial liver biopsies in blood donors with persistent HBs antigenaemia.

Initial liver biopsies from asymptomatic HBs antigen positive blood donors showed a range of histological abnormalities ranging from minor parenchymal lesions to cirrhosis. Twenty of these have now been followed up for periods of up to four years and during that time have had at least two liver biopsies. Throughout the period of study all the donors have remained carriers of HBs Ag, and there was no significant variation in the titers of antigen or the electron microscopic appearances of the serum in individual donors. The histological appearances of subsequent liver biopsies were not always the same as those seen initially, and while there appeared to be some improvement in three cases, there were nine in which the histological appearances were worse.

Interpretation of respiratory tract histology in cot deaths.

The degree of inflammation in the trachea, bronchi, and lungs of 139 cot deaths has been analysed and each case allocated to one of four groups. In group I the changes were considered to be serious enough to have caused death, while group II cases showed similar abnormalities but of a less severe nature, and in this group there was some doubt as to whether they were a significant cause of death. Group III lesions were very minor in type and were not considered to be serious enough to have resulted in the death of the child. There was a good correlation between the degree of inflammation in the respiratory tract, and whether or not bacteria of any type were grown. The great majority of the bacterial pathogens were isolated from the first two groups. Respiratory viruses were isolated from three of the four cases of acute bronchiolitis included in group I, and also from a group II case which showed considerable bronchiolar inflammation. One-third of the cases with minor inflammation in the lung parenchyma (group III) showed some evidence of recent virus infection.

Electron microscopy of serum of healthy hepatitis B antigen carriers.

The sera of 36 blood donors who are established HBsAg carriers were examined with the electron microscope. The findings were correlated with the histological and electronoptic appearances of the liver and the titre and subtype of the antigen. Antigen-antibody complexes could not be detected. Dane particles constituted 2 percent or more of the total particle count in five of the 36 sera, including three sera from five carriers with chronic aggressive hepatitis and two sera from 11 carriers with chronic persistent hepatitis. In sera from carriers with normal histology or the minimal histological lesion of focal parenchymal necrosis they were detected very infrequently or not at all. Three biopsies revealed intranuclear inclusions when examined electronoptically and the corresponding sera all contained greater than 2 percent Dane particles. Where greater than 2 percent Dane particles were seen the antigen titre tended to be high. The predominant subtype was ad. There was no correlation between the number of Dane particles and the antigen subtype nor between subtype and histology.