Plasma cell-free DNA methylation marks for episodic memory impairment: a pilot twin study.

Decline in episodic memory performance usually causes the first clinical symptoms of Alzheimer's disease. At present, Alzheimer's disease can only be diagnosed at a very late stage when neurodegeneration and cognitive impairment is already irreversible. New early disease markers are needed for earlier and more efficient Alzheimer's disease intervention. To identify early disease markers, we implemented a genome-wide bisulphite sequencing method for the analysis of plasma cell-free DNA methylation profiles and compared differences associated with episodic memory performance in Finnish twin pairs. A noticeable amount of cell-free DNA was present in plasma, however, the amounts as well as the genomic coverage of these fragments varied substantially between individuals. We found no significant markers associated with episodic memory performance in the twins' plasma cell-free DNA methylation profiles. Furthermore, our results indicate that due to the low genomic coverage of cell-free DNA fragments and the variety in these fragments between individuals, the implemented genome-wide bisulphite sequencing method is not optimal for comparing cell-free DNA methylation differences between large groups of individuals.

Photochemical regulation of an artificial hydrolase by a backbone incorporated tertiary structure switch.

A stilbene chromophore has been incorporated into the turn region of a 42 amino acid peptide, linking two helical peptide sections. Spatial proximity between these sections, as well as aggregation into dimers, is required to facilitate the catalytic function of this artificial hydrolase. Photomodulation of the hydrolase activity results in an increase of the activity of 42 % upon switching from the trans to the cis isomer of the chromophore. This is rationalized by a change in the aggregation state of the peptidomimetic, which is supported by diffusion coefficients obtained from PFG-NMR experiments. The results show that incorporation of a small, relatively flexible chromophore into a large peptide is capable of inducing a considerable change in tertiary structure and thus, functionality.

Papillary adenocarcinoma of rete testis. Autopsy findings, histochemistry, immunohistochemistry, ultrastructure, and clinical correlations.

Adenocarcinoma of the rete testis is a rare neoplasm that usually occurs in men after the age of 60 and carries a variable prognosis. We report an occurrence of this tumor in a 91-year-old man who had been treated for 2 years for an hydrocele. At the time of diagnosis, metastases were not evident; and the patient was treated with local radiotherapy. The diagnosis of papillary adenocarcinoma of the rete testis was made on the basis of: (a) a transition from normal rete testis to atypical and neoplastic rete epithelium; (b) exclusion of primary germinal and nongerminal testicular tumors and spread from distant sources; and (c) electron-microscopic findings, histochemical and immunological studies, and autopsy findings supporting the diagnosis. This is the first reported case of adenocarcinoma of the rete testis that includes documentation of the tumor's metastatic pattern.

Prevention of paraplegia during aortic operations.

Ischemic spinal cord injury after aortic cross-clamping may be produced by a steal phenomenon. The present study investigates this possibility by directly measuring the oxygen tension on the spinal cord surface in pigs. After simple clamping of the aorta, oxygen tension decreased significantly distal to the clamping site both after occlusion of the thoracic aorta at T3-4 (group 1) and after occlusion of the abdominal aorta at L-1 (group 2). Exclusion of the thoracic aorta by a second clamp at T-13 restored oxygen tension almost to the original level, whereas segmentation of the abdominal aorta up to S-1 hardly affected oxygen tension in the area of the artery of Adamkiewicz in most of the animals. We conclude that after aortic cross-clamping, blood tends to drain away from the spinal cord rather than supplying it longitudinally. Without knowledge of the position of the Adamkiewicz artery in humans as well as of the competence of the collateral circulation in the excluded segment, it is necessary to develop a new strategy for repair of the aorta. We describe and discuss two surgical techniques for the prevention of paraplegia after aortic cross-clamping: the counterocclusion technique and the bypass fractionated technique.

Multiple extra-adrenal and thoracic pheochromocytomas.

On the basis of a case of multiple, extra-adrenal intrathoracic pheochromocytomas (total of 6 tumors), the value of dynamic computerized tomography investigations, venous sampling, scintigrams with 131I-meta iodobenzylguanide, and selective arteriography is discussed.

Congenital tremor in pigs in Sweden. A case report.

The authors describe an outbreak of congenital tremor in piglets in a herd for the integrated production of fattening pigs. All sows farrowing within a period of slightly over a month gave birth to piglets affected to a varying degree. All the sows were of the Swedish Land Race and covered by boars representing two different lines not genetically related to each other. The case history comprised information on oral treatment of the sows with an antiparasitic trichlorfon compound (Neguvon) during pregnancy. Morphological examination of the CNS revealed a marked cerebellar hypoplasia in all examined piglets. Teschen/Talfan virus was isolated from liver and spleen in one of the piglets, but this finding could be repudiated as merely coincidental. It is concluded that there is strong circumstantial evidence for Neguvon treatment as a possible etiologic factor in this tremor outbreak. All relevant data collected are seen from Tables I and II.

Dopamine D(2) receptors regulate tyrosine hydroxylase activity and phosphorylation at Ser40 in rat striatum.

In the striatum, dopamine release is inhibited by activation of dopamine D(2) autoreceptors. Changes in dopamine release have been attributed to changes in the synthesis of dopamine, which is regulated via phosphorylation of tyrosine hydroxylase (TH), the rate-limiting enzyme in the synthesis of catecholamines. Here, we have studied the involvement of dopamine D(2) receptors in the regulation of TH phosphorylation at distinct seryl residues, using phosphorylation site-specific antibodies and a preparation of rat striatal slices. The D(2) receptor agonist, quinpirole, reduced basal TH phosphorylation at Ser40 but not at Ser19 or Ser31. Quinpirole was also able to reduce the increase in Ser40 phosphorylation caused by forskolin, an activator of adenylyl cyclase, without affecting the increase in Ser19 phosphorylation produced by the glutamate receptor agonist, N-methyl-D-aspartate (NMDA). In addition, the dopamine D(2) receptor agonist reduced both basal and forskolin-stimulated activity of TH, measured as 3,4-dihydroxyphenylalanine (DOPA) accumulation. Quinpirole decreased phosphorylation of Ser40 induced by okadaic acid, an inhibitor of protein phosphatase 1 and 2A and Ro-20-1724, a phosphodiesterase inhibitor. In contrast, quinpirole did not affect the increase in Ser40 phosphorylation caused by the cAMP analogue, 8-Br-cAMP. These data indicate that, in the striatum, activation of dopamine D(2) receptors results in selective inhibition of TH phosphorylation at Ser40 via reduction of the activity of adenylyl cyclase. They also provide a molecular mechanism accounting for the ability of dopamine D(2) autoreceptors to inhibit dopamine synthesis and release from nigrostriatal nerve terminals.

Regulation of tyrosine hydroxylase activity and phosphorylation at Ser(19) and Ser(40) via activation of glutamate NMDA receptors in rat striatum.

The activity of tyrosine hydroxylase, the rate-limiting enzyme in the biosynthesis of dopamine, is stimulated by phosphorylation. In this study, we examined the effects of activation of NMDA receptors on the state of phosphorylation and activity of tyrosine hydroxylase in rat striatal slices. NMDA produced a time-and concentration-dependent increase in the levels of phospho-Ser(19)-tyrosine hydroxylase in nigrostriatal nerve terminals. This increase was not associated with any changes in the basal activity of tyrosine hydroxylase, measured as DOPA accumulation. Forskolin, an activator of adenylyl cyclase, stimulated tyrosine hydroxylase phosphorylation at Ser(40) and caused a significant increase in DOPA accumulation. NMDA reduced forskolin-mediated increases in both Ser(40) phosphorylation and DOPA accumulation. In addition, NMDA reduced the increase in phospho-Ser(40)-tyrosine hydroxylase produced by okadaic acid, an inhibitor of protein phosphatase 1 and 2A, but not by a cyclic AMP analogue, 8-bromo-cyclic AMP. These results indicate that, in the striatum, glutamate decreases tyrosine hydroxylase phosphorylation at Ser(40) via activation of NMDA receptors by reducing cyclic AMP production. They also provide a mechanism for the demonstrated ability of NMDA to decrease tyrosine hydroxylase activity and dopamine synthesis.

Gastrointestinal blood loss in haemodialysis patients during use of a low-molecular-weight heparinoid anticoagulant.

In a randomised cross-over study we assessed total blood loss in 14 dialysis patients using 59Fe as a marker for measurement in a whole-body counting system. In one period the patients received standard heparin, in the other ORG 10172, a new low-molecular-weight-heparinoid. Our results show no significant difference between the two study periods with regard to blood loss and dialyser blood retention. In some patients a delayed bleeding ('oozing') from the puncture site was noticed as a side-effect of treatment with the low-molecular-weight-heparinoid. We conclude that this heparinoid is effective as an anticoagulant in regular dialysis treatment, but it seems to have no advantage over standard heparinisation with regard to occult bleeding. This may be related to the prolonged plasma anti-Xa activity (30.8 h) of this compound compared to standard heparin in dialysis patients.

Severe cardiopathy in branching enzyme deficiency.

A 7 1/2-year-old girl had exercise intolerance and exertional dyspnea. Four months later, congestive heart failure developed, with recurrent chylous pleural effusions, and she died at age 8 1/2 years. Endomyocardial biopsy tissue showed abundant PAS-positive, diastase-resistant cytoplasmic deposits. Similar inclusions were seen in muscle, skin, and liver specimens. Postmortem studies showed that the abnormal polysaccharide was especially abundant in heart and muscle, but was also present in all other tissues, including the central nervous system. Glycogen isolated from heart, muscle, and spinal cord showed a shift of the iodine spectrum toward higher than normal wavelengths. Branching enzyme activity was lacking in the muscle biopsy specimen and in all postmortem tissues; glycogenolytic enzymes had normal activities. These studies show that cardiomyopathy can be the first symptom of generalized branching enzyme deficiency and that the degree of accumulation of the abnormal polysaccharide may vary in different tissues.