Comment: Positive Mitsuda lepromin reaction in long-term treated lepromatous leprosy and tuberculoid relapse in lepromatous leprosy.
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Humans↗
Biomedical subjects
J Walter
Publications and source records attributed to J Walter.
Is guidance of chick retinal axons in vitro influenced by proteases?
Rhodamine-labeled explants of embryonic chick retinae were placed on a substratum consisting of alternating lanes of cell membranes derived from anterior and posterior chick optic tectum. Extending axons from temporal retinae prefer to grow in vitro on anterior tectal membranes because of a repulsive component within posterior membranes obtained from a tectum area which is not innervated by these axons in vivo. None of 16 protease inhibitors, specific for all known protease classes, when added to the culture medium, neutralized the repulsive activity of posterior membranes suggesting that the repulsive activity is not a protease. However, 2 metalloprotease inhibitors affect growth cone morphology and axon-axon interactions.
Animals↗
The amino acid sequence of the CCGG recognizing DNA methyltransferase M.BsuFI: implications for the analysis of sequence recognition by cytosine DNA methyltransferases.
The Bacillus subtilis FI DNA methyltransferase (M.BsuFI) modifies the outer cytosine of the DNA sequence CCGG, causing resistance against R.BsuFI and R.MspI restriction. The M.BsuFI gene was cloned and expressed in B.subtilis and Escherichia coli. As derived from the nucleotide sequence, the M.BsuFI protein has 409 amino acids, corresponding to a molecular mass of 46,918 daltons. Including these data we have compared the nucleotide and amino acid sequences of different CCGG recognizing enzymes. These analyses showed that M.BsuFI is highly related to two other CCGG specific methyltransferases, M.MspI and M.HpaII, which were isolated from Gram-negative bacteria. Between M.BsuFI and M.MspI the sequence similarity is particularly significant in a region, which has been postulated to contain the target recognition domains (TRDs) of cytosine-specific DNA methyltransferases. Apparently M.BsuFI and M.MspI, derived from phylogenetic distant organisms, use highly conserved structural elements for the recognition of the CCGG target sequence. In contrast the very same region of M.HpaII is quite different from those of M.BsuFI and M.MspI. We attribute this difference to the different targeting of methylation within the sequence CCGG, where M.HpaII methylates the inner, M.BsuFI/M.MspI the outer cytosine. Also the CCGG recognizing TRD of the multispecific B.subtilis phage SPR Mtase is distinct from that of the host enzyme, possibly indicating different requirements for TRDs operative in mono- and multispecific enzymes.
Amino Acid Sequence↗
A common denominator of growth cone guidance and collapse?
Axonal guidance in the retinotectal system and in spinal nerve segmentation is based on repulsion or inhibition. In both systems the membrane glycoprotein responsible for the guiding activity is capable of inducing growth cone collapse. We discuss two models of axonal guidance that correlate axonal guidance and growth cone collapse. The models are applicable to axon guidance by membrane-associated or diffusible stimuli, and are not based on preferential adhesion of axons to certain substrata.
Animals↗
Changes of arterial prostaglandin E2 during haemodialysis.
The absence of a reduction in peripheral vascular resistance secondary to hypervolaemia leads to so-called volume hypertension. In order to study whether a deficient formation of the vasodilator autacoid prostaglandin E2 (PGE2) contributes to the preservation of inadequate vascular tone during extracellular volume expansion, arterial plasma PGE2 and the stable PGE2 metabolite 13,14-dihydro-15-keto-PGE2 (PGE2-M) were determined in 13 oligoanuric women on chronic haemodialysis. Prior to treatment eight of them had hypervolaemia and hypertension (mean arterial pressure (MAP) 128 +/- 3 mmHg (mean +/- SE] and five patients had hypervolaemia of a similar degree but were not hypertensive (MAP: 99 +/- 4 mmHg P less than 0.005). Before haemodialysis the arterial PGE2 and PGE2-M concentrations were less (P less than 0.05) in hypertensive (11 observations in eight patients) than in normotensive patients (ten observations in five patients). As blood pressure decreased during the course of haemodialysis of volume hypertensive patients, the concentration of PGE2 and PGE2-M increased (P less than 0.02) by 104 +/- 43% and 89 +/- 32%, respectively. In normotensive patients neither blood pressure nor the concentration of PGE2 and PGE2-M were found to change during treatment. Since volume hypertension was associated with reduced values and dialysis induced normalisation of blood pressure with increased arterial values of PGE2 and PGE2-M, we hypothesise that the development of hypertension associated with fluid overload of haemodialysed patients may be related to a decreased release of prostaglandin E2.
Adolescent↗
Directional cues for retinal axons.
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Animals↗
Effects of nisoldipine on stress-induced changes in haemodynamics and plasma catecholamines in normotensives and hypertensives.
In a double-blind, placebo-controlled crossover study 10 mg nisoldipine was given orally twice daily for 3.5 days to 12 normotensives and 12 essential hypertensives. In each study period, subjects were exposed to 6 min of physical exercise and 3 min of mental stress following the morning dose on day 3 and 4, respectively. Blood pressure, heart rate, systolic time intervals (day 3 only) and plasma levels of noradrenaline, adrenaline, dopamine as well as dihydroxyphenylglycol (DOPEG; the main presynaptic metabolite of noradrenaline) were determined at rest and at the end of both tests. Nisoldipine increased resting heart rate in normotensives and hypertensives, but reduced resting BP and BP during mental stress in hypertensives only. It also increased plasma concentrations of noradrenaline and DOPEG at rest and plasma noradrenaline concentrations during mental stress in both groups. However, nisoldipine affected neither exercise- nor stress-induced changes in any of the parameters monitored here. There was a correlation between the drug-induced percentage fall in resting BP and the height of BP during placebo treatment. While the resting values of plasma DOPEG were higher in hypertensives than in normotensives, those of plasma noradrenaline were not. Consequently, the linear relationship that existed between the resting plasma concentrations of DOPEG and noradrenaline in both groups was shifted to higher DOPEG levels in hypertensives when compared with normotensives. In conclusion, the effectiveness of nisoldipine in lowering BP was the more pronounced the higher the BP to begin with. Nisoldipine did not attenuate exercise- or stress-induced increases in plasma catecholamines. Essential hypertension may be associated with an enhanced presynaptic formation of DOPEG.
Adult↗
Axonal guidance by an avoidance mechanism.
1. On a substrate consisting of alternating lanes of anterior and posterior tectal membranes, temporal retinal axons have a strong tendency to grow on the lanes of anterior membranes and to avoid the lanes of posterior membranes. 2. Temporal axons do extend neurites on posterior material, and in equivalent numbers and lengths to that of anterior membranes if the substrate consists of pure anterior or posterior membranes. 3. Inactivation of posterior membranes by heat or the enzyme phosphatidylinositol-specific phospholipase C (PI-PLC) abolishes their ability to induce the avoidance reaction of temporal axons. It is concluded that the posterior membranes contain a repulsive component for temporal retinal axons. 4. Growth cones growing on anterior membranes, which encounter posterior membranes at the strip boundary, in general do not become reduced in their growth rate. 5. These results are most easily explained by a "gradient-reading model" similar to chemotaxis where the steering of a growth cone is independent on the growth rate. 6. According to the model, a gradient of a guiding component outside the growth cone is transformed into an internal gradient which gives the growth cone its directionality. 7. Other models like growth inhibition cannot be ruled out but need at least two additional assumptions like habituation for growth on the putative posterior inhibitory substrate and a strong local restriction of the inhibitory effect within the growth cone which contacts the posterior material.
Animals↗
Sequence, internal homology and high-level expression of the gene for a DNA-(cytosine N4)-methyltransferase, M.Pvu II.
The base sequence of the pvuIIM gene has been determined. This gene codes for a DNA-(cytosine N4)-methyltransferase, M.Pvu II. The base sequence contains a single large open reading frame that predicts a 38.3kDa polypeptide, consistent with experimental data. The pvuIIM gene contains some sequences common to DNA methyltransferases in general, but includes none of the sequences specifically conserved among DNA-(cytosine 5)-methyltransferases. The pvuIIM sequence also reveals an internal homology at the amino acid level, each half of which spans over 100 amino acids and is itself homologous to the sequences of some DNA-(adenine N6)-methyltransferases. A derivative of the pvuIIM plasmid was constructed to allow high-level production of M.Pvu II. Specifically, the composite Ptac promoter was inserted 5' to pvuIIM, intervening DNA was deleted, and the resulting construct was used to transform an mcrB laclq strain of Escherichia coli. When this transformant was induced with isopropyl-B-D-galactopyranoside (IPTG), growth rapidly ceased and M.Pvu II accumulated to the point of comprising over 10% of the total soluble protein.
Amino Acid Sequence↗
Financing patient education in arthritis and musculoskeletal and skin diseases.
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Arthritis↗
Tumor cell recruitment in the mouse adenocarcinoma EO 771 directly demonstrated by double labeling with [3H]- and [14C] thymidine and flow cytometry.
Tumor cell recruitment in the mouse adenocarcinoma EO 771 after application of 1-beta-D-arabinofuranosylcytosine (AraCyt) has been directly demonstrated by double labeling with [3H]- and [14C]-thymidine. This method enables a quantitative study of the extent and time course of tumor cell recruitment in this solid mouse tumor. The results show that tumor cell recruitment is a continuous process that starts early after AraCyt application (about 4-8 h) and lasts about 1 day with a maximum at about 12 h after Ara-Cyt application. Up to 40% of all cells are recruited at that time. The recruited tumor cells re-enter the resting state after having passed through one cycle.
Adenocarcinoma↗
Haemodynamics as a determinant of the pharmacokinetics of and the plasma catecholamine responses to isoprenaline.
The total body clearance and fractional extraction of isoprenaline (ISO) have been determined, and the relation between these parameters and cardiac output established. Whether desipramine, an inhibitor of neuronal uptake, altered the plasma catecholamine response to ISO was also investigated. Seven healthy subjects were given i.v., infusions of ISO in two, consecutive 25-min periods, at constant dose rates of 31-43 and 80-124 pmol.kg-1.min-1, respectively. The total-body (ER), pulmonary (ERp) and forearm (ERf) fractional extractions and the total body clearance (CL) of ISO were obtained from measurements of cardiac output and the steady-state ISO concentration in mixed central venous, arterial and forearm venous plasma. ISO-induced increases in cardiac output resulted in increases in CL, decreases in ER and no consistent change in ERf. ERp did not differ from zero. ISO also produced a dose-dependent increase in the mixed venous plasma concentrations of noradrenaline and 3,4-dihydroxyphenylglycol (DOPEG), and a decrease in that of adrenaline. Pretreatment with desipramine did not alter any of the pharmacokinetic parameters of ISO. Desipramine, however, reduced the mixed venous baseline plasma levels of noradrenaline (47%) and DOPEG (40%), and tended to reduce that of adrenaline (34%). It enhanced the plasma noradrenaline response 2.4-fold, abolished the plasma DOPEG response and did not alter the plasma adrenaline response to ISO. Hence, owing to its haemodynamic effects, ISO modifies its own pharmacokinetics which involve non-neuronal removal processes only. The increased DOPEG in plasma resulting from the ISO-induced increase in noradrenaline release was presynaptic in origin. Desipramine appears to reduce sympathetic activity.(ABSTRACT TRUNCATED AT 250 WORDS)
Adult↗
The post-lepromin scar and its significance in the control of HD.
In the past little attention has been paid to the post-lepromin scar (PLS) and its use in controlling Hansen's disease (HD), particularly in the prognosis, classification and measurement of CMI response. The immuno-information of the Mitsuda reaction is thought to be informative only in the extreme range of 10 + mm or in its absence. Previous studies have shown that the range of PLS formation increases proportionally to the degree of lepromin positivity. PLS positive HD patients have a stable form of the disease with good prognosis. Those unable to form a PLS have a marked tendency to downgrade towards the lepromatous form of HD. PLS formation appears to indicate a CMI response to M. leprae implying immunity. It is thought that there exists a correlation between the PLS and the lymphocyte transformation test (LTT), both reaching their optimum measurement three months after the M. leprae injection, either with lepromin or M. leprae suspension used for the anti-HD vaccine. It is proposed to study the use of the PLS in HD control programs on a trial basis with the objective of its general introduction as part of the management of HD control. Considerable improvements in the prognosis, classification and application of treatment can be expected from such a measure. The discovery of the armadilo as a source of M. leprae by Kirchheimer and Storrs facilitates the availability of lepromin A and its purified version, lepromin Ap. The relevant studies have shown that a 40 M/bact/ml lepromin A suspension should be used for the application of lepromin in control programs.(ABSTRACT TRUNCATED AT 250 WORDS)
Cicatrix↗
[A modification of the ABC method (avidin-biotin-peroxidase complex) for the detection of viral antigens in coronavirus infections in cats (FIP) and parvovirus type 2 infections in dogs].
A modified ABC-method (avidin-biotin-peroxidase complex) is established to demonstrate viral antigens in paraffin sections of tissues of coronavirus (FIP) infected cats and parvovirus type 2 infected dogs using monoclonal antibodies. The pros and cons and potential sources of error are described and discussed.
Animals↗
[Social training of alcoholic traffic offenders completing a penal term--a general practice report].
This is to inform about a practical introduction of a training for alcoholic traffic-offenders in the liberal Sachsenheim-branch of the Pforzheim penal institution. There prisoners have the opportunity to participate in re-training by traffic psychologists of the "TUV" (Technical Surveillance Organization) in order to improve their aptitude to drive motor vehicles. The experience with the first 10 courses are said to be good, however, it is not possible to give an opinion on the efficiency of those measures.
Accidents, Traffic↗
Plasma concentrations of noradrenaline and 3,4-dihydroxyphenylethyleneglycol under conditions of enhanced sympathetic activity.
Antecubital venous blood was sampled at rest and during orthostasis or supine bicycle exercise. The plasma was analyzed for noradrenaline and 3,4-dihydroxyphenylethyleneglycol (DOPEG) by HPLC. Orthostasis resulted in increases in plasma concentrations of both noradrenaline and DOPEG. The magnitude of changes in both was dependent on the degree of orthostasis. In conditions of supine rest, sitting, and standing the plot of the geometric mean values of plasma DOPEG (ordinate) against those of plasma noradrenaline was linear, had a slope of about unity, and intersected the ordinate at a finite value of plasma DOPEG. After administration of desipramine (to block uptake), plasma concentrations of DOPEG fell both at rest and during orthostasis. Moreover, desipramine abolished the plasma DOPEG response to orthostasis without affecting the plasma noradrenaline response. Hence, changes in plasma DOPEG brought about by changes in sympathetic tone are presynaptic in origin. The plasma concentration of DOPEG observed in the presence of desipramine was virtually identical with the ordinate intercept of the regression line relating plasma DOPEG to plasma noradrenaline in the absence of desipramine. This pool of plasma DOPEG (which amounted to about 75% of that observed at supine rest in the absence of desipramine) probably stems from intraneuronal noradrenaline leaking out of the storage vesicles of peripheral sympathetic neurones and may in part also be derived from the central nervous system. Supine bicycle exercise failed to increase plasma DOPEG. This may be due to the separation of the sampling site from the site of noradrenaline release (i.e. the exercising limbs) by organs involved in DOPEG extraction.(ABSTRACT TRUNCATED AT 250 WORDS)
Adult↗
Cytogenetic study of cattle affected by persistent lymphocytosis.
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Animals↗