Physicochemical modeling of the role of free radicals in photodynamic therapy

A new kinetic approach is suggested and experimentally supported for quantification of the spin-trapping procedure. Accordingly, the concentration of the spin adduct formed in the interaction between the spin-trap DMPO and various free radicals (cyanopropylperoxy, cumylperoxy, phenylethylperoxy, and hydroperoxy radicals) generated by the initiated oxidation of the parent molecules is followed by kinetic ESR spectrometry. The initial sections of the corresponding kinetics are linear indicating that during this period the consumption of the adduct is negligible and thus the rate of accumulation (W(A)) approximates the rate of formation (W(f)): W(A) approximately W(f) = k(ST)[Rad(*)][DMPO], supported also by the fact that the rate of initiation of oxidation equals W(A) at high [DMPO]. In addition, the circulatory experimental apparatus enables calculation of the rate of molecular decomposition of the adduct by stopping circulation (W(f) becomes negligible) and following the decrease of the ESR signal. Corresponding rate constants are summarized.

A golgi and a combined Golgi/GABA immunogold study of local circuit neurons in the homing pigeon hippocampus

Three types of local circuit neurons have recently been reported in the homing pigeon hippocampus. The principal type appears to be constituted by the medium-sized angular or ovoid local circuit neurons that occur in all layers of the hippocampus. The current Golgi study has revealed that these neurons can be classified according to their axonal arborisation extension: (1) in all directions, (2) principally medio-laterally, or (3) dorso-ventrally. The local circuit neurons with dorso-ventral axon arborisation are present only in the subpyramidal layer. Serial sections of a Golgi-impregnated medium-sized, multiangular local circuit neuron in the pyramidal layer and a small, ovoid neuron in the suprapyramidal layer were investigated in the electron microscope. Some of these sections were processed for GABA immunogold cytochemistry. The soma and large dendrites of both neurons displayed GABA immunogold labelling. On the soma of medium-sized local circuit neuron there were numerous terminals; on the soma of the small one relatively fewer terminals were observed. The terminals contained round and/or flat synaptic vesicles. The long axonal branches of the neurons exhibited varicosities containing flattened or pleomorphic vesicles. Axo-dendritic, axo-somatic and a few axo-axonic synapses were observed. The large dense axon arborisation field of medium-sized local circuit neurons is properly situated to modulate intrinsic hippocampal activity and that of the small local circuit neurons is well situated to modulate the hippocampal input in the suprapyramidal layer.

Mirror image mutations reveal the significance of an intersubunit ion cluster in the stability of 3-isopropylmalate dehydrogenase

The comparison of the three-dimensional structures of thermophilic (Thermus thermophilus) and mesophilic (Escherichia coli) 3-isopropylmalate dehydrogenases (IPMDH, EC 1.1.1.85) suggested that the existence of extra ion pairs in the thermophilic enzyme found in the intersubunit region may be an important factor for thermostability. As a test of our assumption, glutamine 200 in the E. coli enzyme was turned into glutamate (Q200E mutant) to mimic the thermophilic enzyme at this site by creating an intersubunit ion pair which can join existing ion clusters. At the same site in the thermophilic enzyme we changed glutamate 190 into glutamine (E190Q), hereby removing the corresponding ion pair. These single amino acid replacements resulted in increased thermostability of the mesophilic and decreased thermostability of the thermophilic enzyme, as measured by spectropolarimetry and differential scanning microcalorimetry.

A comparative Golgi study of chicken (Gallus domesticus) and homing pigeon (Columba livia) hippocampus

Neurons and fibres in the chick and homing pigeon hippocampus were described following Golgi impregnation. Two principal classes of neurons were distinguished: projection neurons with distant projecting axons and spiny dendrites, and local circuit neurons. In the homing pigeon and chicken hippocampus there are three types of projection neurons: pyramidal, pyramidal-like and multipolar. The pyramidal and pyramidal-like neurons are only found in the central 'pyramidal' layer of the hippocampus whereas multipolar neurons are present in the suprapyramidal, pyramidal and infrapyramidal layers. The axon of projection neurons typically emits several varicose collaterals from the initial section. Most of these collaterals extend along the infrapyramidal layer of the hippocampus, while others ascend to the pyramidal and suprapyramidal layers where they branch. The number of impregnated axon collaterals was higher in the homing pigeon than in the chick hippocampus. A variety of multi-angular/ovoid local circuit neurons ranging from small to large size are found in the homing pigeon and chick hippocampus. Their axons develop local arborization of varicose branches, the extent of which varies with the type of local circuit neurons. The density of GABA immunopositive local circuit neurons was found to be greater in the homing pigeon than in the chick. The profuse arborization of projection neuron axon collaterals and the higher density of GABA-immunopositive local circuit neurons in the homing pigeon hippocampus may underlie the differences in hippocampal function between the homing pigeon and chick, and this complex local connectivity may contribute to the ability of spatial orientation and memory.

Liver transplantation in alpha(1)-antitrypsin deficiency

Only a minority of infants born with alpha(1)-antitrypsin deficiency will develop serious liver disease during childhood, mostly but not always after neonatal cholestasis. Early prognosis is difficult and all children have to be followed up carefully. The liver disease progresses with varying speed and it lacks specific features. At the time of liver transplantation the young patients have no pulmonary disease induced by the deficiency and in those with renal involvement, the kidney problems can mostly be dealt with by conservative therapy. The peri- and postoperative care of the patients who undergo liver transplantation does not differ from the usual routines.

Comparisons of fatness indicators in Budapest children

The aim of this study was to estimate the fatness level of Budapest children and youth in different ways and to compare these estimations using a large representative sample. Eighteen body measurements were taken on 2606 healthy boys and 2471 healthy girls aged between 3 and 18 years. About 20% of this sample was measured by the Futrex 5000A near infrared (NIR) spectrophotometer to assess the body fat percent (data of 419 boys and 462 girls aged between 5 and 18 years were analysed). Triceps skinfold thickness (TSF), sum of triceps, medial calf, subscapular and suprailiac skinfold thicknesses (SFS), body fat percent estimated according to Slaughter et al. (%BF), BMI (calculated from height and weight) and body fat percent assessed by NIR-method (NIR%BF) were compared. chi 2 tests of independence show significant connections among the distributions ranged by the five fatness indicators. However, correlation coefficients and standard errors indicate that strong relationships are only among the assessments based on skinfold thicknesses (r = 0.92-0.97, SEE = 1.8-2.6%). BMI and NIR%BF assess body fatness differently compared to skinfold thicknesses: r-values are moderate and SEE-values are relatively large (r = 0.59-0.87, SEE = 1.9-4.7%). These findings can be seen in both the boys and the girls. NIR%BF comparing to %BF significantly overpredicts body fat percent in the boys and significantly underpredicts it in the girls. BMI, height and weight are not in significant correlation with NIR%BF in the boys but there are moderate correlations in the girls. Our suggestion is that more research is needed with the use of NIR-method in children and adolescents, and it is necessary to refine prediction equations taking into consideration very carefully sex sand age differences.

Closure of an oropharyngocutaneous fistula in an irradiated patient. A case report

A case of oropharyngocutaneous fistula is presented in a preoperatively irradiated patient. A double-layer closure, using a modified Owens flap, was used to obtain a satisfactory result.

Physico-chemical modeling of the role of free radicals in photodynamic therapy. IV. Quantitative aspects of photodynamic effects on free radicals generated in cell cultures

Production and the mechanism of the interactions of free radicals generated by stimulated macrophages in the presence of luminol and a free radical inhibitor was investigated to determine the possibility of using luminol-dependent chemiluminescence for studying photodynamic effects in biology. Earlier measurements have been revisited and additional experiments performed indicating that oxidation products of luminol neither inhibit the in vitro formation of radicals nor quench CL. Simulation based on the mechanism suggested revealed that the likely value for the rate constant of the primary step between luminol and superoxide anion radicals producing luminol radicals is 5x10(2)-1x10(3) M-1s-1. It has been established that the ratio of the concentration of radicals generated by the biological system to that formed by oxidation of luminol exceeds 10(3); that is, the contribution of the latter is negligible and the system is appropriate to measure quantitatively the effect of excited photosensitizers on free radicals.

Electron microscopic data on the neurons of nuclei subpretectalis and posterior-ventralis thalami. A combined immunohistochemical study

The nucleus rotundus receives GABA-like immunoreactive fibres from the nuclei subpretectalis and postero-ventralis thalami. This result was confirmed by Phaseolus vulgaris leucoagglutinin (PhA-L) anterograde tracer and with electron microscopic (EM) gamma-aminobutiric acid (GABA)-immunogold staining. The detailed electron microscopic analysis of the structure of the neurons in these nuclei revealed that the neurons in the nucleus subpretectalis displayed GABA-like immunoreactivity. In the postero-ventral thalamic nucleus a group of neurons was GABA-positive. The surface of the neurons was covered both with numerous GABA-negative and GABA-like immunoreactive terminals that established asymmetrical and symmetrical synapses, respectively, with the GABA-positive neurons. The GABA-like immunonegative terminals are supposed to be the axon terminals of the collaterals of tecto-rotundal fibres in the subpretectal nucleus and the collateral terminal branches of contralateral tecto-rotundal fibres in the postero-ventralis thalami. In both nuclei, the GABA-like immunoreactive terminals may be developed by the collaterals of local neurons that establish symmetrical synapses. In the Phaseolus lectin-stained preparations these terminals may be labelled. The morphological characteristics of the neurons in the subpretectal and partly, in the posteroventral nuclei are similar to those of interneurons (local circuit neurons) and the numerous asymmetrical and symmetrical axo-somatic synapses, respectively. But these neurons locate outside of their target nucleus, and exert their modulatory effect on rotundo-ectostriatal transmission. Also, a contralateral influence is present in the nucleus rotundus that may interact in the cooperation of the eyes. The neurons of the subpretectal and posteroventral nuclei, similarly to the neurons of isthmic nuclei, are a special group of modulatory neurons with effects at a distance.

A gene encoding a liver-specific ABC transporter is mutated in progressive familial intrahepatic cholestasis

The progressive familial intrahepatic cholestases (PFIC) are a group of inherited disorders with severe cholestatic liver disease from early infancy. A subgroup characterized by normal serum cholesterol and gamma-glutamyltranspeptidase (gammaGT) levels is genetically heterogeneous with loci on chromosomes 2q (PFIC2) and 18q. The phenotype of the PFIC2-linked group is consistent with defective bile acid transport at the hepatocyte canalicular membrane. The PFIC2 gene has now been identified by mutations in a positional candidate, BSEP, which encodes a liver-specific ATP-binding cassette (ABC) transporter, sister of p-glycoprotein (SPGP). The product of the orthologous rat gene has been shown to be an effective bile acid transporter in vitro. These data provide evidence that SPGP is the human bile salt export pump (BSEP).

[Surgical management of oro-cutaneous and pharyngo-cutaneous fistulae]

Pharyngocutan- or orocutan fistulas have been observed in 8.2% of patients after cancer operations at author's clinic. As first therapy the authors used a conservative treatment, and observed a closure in 7 patients while the remaining 5 patients were operated on. From these 5 last cases 3 had large and 2 had mid size fistulas. Four surgically treated patients had radiotherapy, but after conservative treatment their fistulas showed reepithelisation and lack of inflammatory reaction. These fistulas were closed with internal- and external (double) flaps. In all cases the internal flaps were prepared from surrounding tissues of the fistulas while the sternocleidomastoid-, the trapezius- and platysma-myocutan flaps were used externally.

GABA-immunohistological observations, at the electron-microscopical level, of the neurons of isthmic nuclei in chicken, Gallus domesticus

Following a demonstration of Golgi-impregnated neurons and their terminal axon arborization in the optic tectum, the neurons of the nucleus parvocellularis and magnocellularis isthmi were studied by means of postembedded electron-microscopical (EM) gamma-aminobutyric acid (GABA)-immunogold staining. In the parvocellular nucleus, none of the neuronal cell bodies or dendrites displayed GABA-like immunoreactivity in EM preparations stained by postembedded GABA-immunogold. However, numerous GABA-like immunoreactive and also unlabeled terminals established synapses with GABA-negative neurons. GABA-like immunoreactive terminals were usually found at the dendritic origin. Around the dendritic profiles, isolated synapses of both GABA-like immunoreactive and immunonegative terminals established glomerulus-like structures enclosed by glial processes. All giant and large neurons of the magnocellular nucleus of the isthmi displayed GABA-like immunoreactivity. Their cell surface was completely covered by GABA-like immunoreactive and unlabeled terminals that established synapses with the neurons. These neurons are thought to send axon collaterals to the parvocellular nucleus; their axons enter the tectum opticum. The morphological characteristics of neurons of both isthmic nuclei are like those of interneurons, because of their numerous axosomatic synapses with both asymmetrical and symmetrical features. These neurons are not located among their target neurons and exert their modulatory effect on optic transmission in the optic tectum at a distance.

[Molecular genetic markers of Alzheimer dementia]

Alzheimer's dementia (AD) is a progressive neurodegenerative disease which is one of the most common forms of dementia in the above 65 years old age group. Diagnosis is based upon evaluation of cognitive skills, elimination of other dementia associated diseases and on cranial CT examination. However, definitive diagnosis is proved only by neurohistological findings. The etiology of the disease is unknown and effective treatment is not available. Intensive research into the pathomechanism of the disease revealed a connection between increased frequency of apolipoprotein E4 allele and later onset of AD. The aim of the author's research was to characterize apolipoprotein E polymorphisms in AD patients and to examine immunological factors which could play an important role in the development of the disease such as the polymorphism of complement and lipoprotein(a) [Lp(a)] alleles previously had not been investigated. 35 AD patients (26 female, 9 male) were examined (mean age 66.4 years +/- 8.7 SD). 18 of these patients showed late onset of the disease. The E4 allele was significantly more frequent in both early and late onset groups compared to controls (0.29 vs. 0.14 and 0.33 vs 0.09). The high frequency of apo E4 found in the early onset group in this study differs from other international data. Serum lipid, lipoproteins, Lp(a) concentrations and Lp(a) phenotype distribution showed no significant difference compared to controls. Furthermore, it was found that the frequency of complement C4AQ0 (null) and Bf F alleles was higher in the late onset AD group compared to controls (0.35 vs 0.139 and 0.305 vs. 0.225) suggesting an active involvement of the complement system in the pathogenesis of this disease.

[Helicobacter pylori in benign gastroduodenal diseases]

(A light- and electronmicroscopic study). We have examined the occurrence of Helicobacter pylori (HP) in 2937 gastric antral biopsy specimens from 979 patients with upper gastrointestinal symptoms. The incidence of HP proved to be 50.5%. The endoscopic diagnoses were: gastritis (62 cases), gastric erosion (425), gastric ulcer (51), duodenitis (22), duodenal erosion (119), duodenal ulcer (122) and the HP incidence was 29, 46, 63,, 50, 66 and 73%, respectively. Microscopic findings were: chronic gastritis (442), chronic active gastritis (356) and normal mucosa (181). The prevalence of HP in these groups was 43%, 78% and 11%, respectively. The activity of gastritis was in good correlation with HP infection. We did not see epithelial damage, and found only a few instances of mucus depletion. Electronmicroscopic examination was performed in order to investigate the morphology of bacterium and its relation to the mucosal cells. We observed mild loss of microvilli on the cell surface and did not see any cell invasion by bacteria.

[Effect of Gevilon therapy and its relation to E polymorphism]

Our clinical trial was set out to estimate the apoE allele frequency by way of polymerase chain reaction and restriction enzyme isoform genotyping amongst 81 obese, hyperlipoproteinemic patients (treated with gemfibrozil + diet). The relative frequencies of the E2, E3, E4 alleles were 0.28, 0.61, 0.11 respectively (according to the Hardy-Weinberg equilibrium). Phenotypes with increased triglycerides levels were dominant in both sexes: IV + V > II/B > II/A (44.4%, 39.5%, 16.0%). Therapy significantly decreased the atherogen lipid values with differing efficacy among each genotype group: E3 > E4 > E2. Our findings demonstrate that in the II/A group there was no great change using the gemfibrozil + diet combination: whereas in IV + V group this combination was effective in each apoE isoform. In the case of II/B it is highly important to determine the apoE genotypes, because the therapy is only efficacious in the E33 group taking all lipid parameters into consideration.

Phaseolus vulgaris lectin labelled and GABA immunogold stained terminals in nucleus rotundus. An EM study

Having injected Phaseolus Vulgaris Lectin (PhA-L) iontophoretically to subpretectal (SP) and postero-ventralis (PV) thalamic nuclei, labelled fibers and terminals appeared in nucleus rotundus (Rt). The PhA-L immunostained fibers are divided dichotomically and they develop long terminal sections with large varicosities. In EM preparates PhA-L labelled terminals were observed establishing axo-somatic, axo-dendritic symmetrical synapses. These terminals were stained by GABA immunogold procedure and proved to be GABA-ergic, i.e. the neurons of SP and PV nuclei supply the principal neurons of Rt with GABA positive terminals, which are located on specific, exponent loci of the principal neuron.

Dynamism of cytoprotective and antisecretory drugs in patients with unhealed gastric and duodenal ulcers

A continuous multiclinical, randomized and prospective study has been carried out in our department to compare the efficacy of different cytoprotective (sucralfate, DE-NOL, Vitamin A) and antisecretory drugs (atropine, cimetidine, ranitidine, famotidine, pirenzepine) on ulcer healing in patients with chronic gastric ulcer (GU) and duodenal ulcer (DU). A total of 441 patients were randomized in different groups. The patients were treated with atropine (1 mg/day), cimetidine (1000 mg/day), ranitidine (300 mg/day), famotidine (80 mg/day), pirenzepine (50 mg/day), sucralfate (1000 mg/day), Vitamin A (3 x 50,000 IU/day) alone or in combination with cyproheptadinum (3 x 4 mg/day) DE-NOL (3 x 5 mL/day) and Tisacid (Al-Mg-hydroxycarbonicum; in different doses). Endoscopy (planimetric evaluation of ulcer sizes), measurements of clinical changes in patients' complaints, antacid consumption and laboratory tests (blood counts, urine, kidney and liver functions, electrolytes, pH status) were carried out at the beginning and 2, 4 and 6 weeks after treatment with different drugs. The incidence of ulcers, changes of ulcer sizes, subjective pain score and antacid consumption were noted at the abovementioned times. There were 20 or more patients in each group. The dynamism of ulcer healing rate was studied on the unhealed GU and DU. Our results showed that the ulcer size decreased significantly in all groups in GU and DU patients treated with cytoprotective and antisecretory drugs. Summed pain score (expressed as per cent of basic values) and antacid consumption decreased significantly in all groups. As well, some differences were found in the dynamism of ulcer healing at 2 weeks after the treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Quantitative immuno-gold labelling and ultrastructural preservation after cryofixation (combined with different freeze-substitution and embedding protocols) and after chemical fixation and cryosectioning. Analysis of the secretory organelle matrix of Paramecium trichocysts

Among the variety of parameters affecting immuno-gold labelling efficiency, mainly the effects of different preparative protocols were tested. Preservation of ultrastructure and of antigenicity are the salient features of this study. We have labelled insoluble components of the secretory matrix of Paramecium trichocysts with specific antisera, using 10 nm colloidal gold particles. The highest labelling efficiency was obtained with fast freezing (cryofixation, either by sandwich or spray-freezing), freeze-substitution in methanol (without added fixatives) and hydrophilic Lowicryls, particularly when applied at low temperatures (K11M at 193 K). The presence of different chemical fixatives always reduced the labelling density and some recommendations from the literature do not appear advisable. Methods commencing with fixation at greater than or equal to 0 degree C, such as "progressive lowering of temperature" (PLT) or preparation of cryostat sections, i.e. with chemical pretreatments, always resulted in lower labelling density. Our data appear, therefore, relevant for optimal immuno-gold labelling of insoluble antigens and emphasize the potential of cryofixation as a primary preparation step. In addition, ultrastructural preservation was also superior after cryofixation.

Mechanisms of vagal nerve in gastric mucosal defense: unchanged gastric emptying and increased vascular permeability

Gastric cytoprotection in response to different agents (prostaglandins, carotenoids, etc.) failed to occur after surgical vagotomy. Decreased gastric emptying and the increased vascular permeability were tested in ethanol-treated rats without and with bilateral surgical vagotomy. The experiments were carried out on Sprague-Dawley rats. The animals were fasted for 24 h before experiments. Bilateral surgical vagotomy or only laparatomy were carried out at 30 min before administration of ethanol (96%, 1 ml). The animals were killed at 0, 1, 5, 15, and 60 min after ethanol administration, when the number and severity of gastric mucosal lesions were noted. In another series of experiments, the animal received Evans blue (1 mg/100 g) i.v. 15 min before killing. The gastric contents were collected and the glandular mucosa was scraped. Evans blue was extracted in chloroform, and its concentration was spectrophotometrically measured. It has been found that (a) both number of lesions and severity of ethanol-induced gastric mucosal damage were larger at each time period in surgically vagotomized rats than in rats with intact vagal nerves; (b) the increased vascular permeability was significantly higher in gastric mucosa at an early period in surgically vagotomized rats compared to rats with intact vagal nerve; (c) the increased vascular events preceded the development of macroscopic appearance of gastric mucosa damage in both groups of animals; and (d) the time-related responses were the same in both groups of animals. It is concluded that increased vascular permeability, but not gastric emptying, probably has some role in the failure of the development of gastric cytoprotection in surgically vagotomized rats.

Effect of phototherapy on 3H-imipramine binding sites in patients with SAD, non-SAD and in healthy controls

The effect of incandescent light treatment on the density of 3H-imipramine binding sites (Bmax) was investigated in 17 patients with seasonal affective disorder, in eight patients with non-seasonal depression and in six healthy volunteers. A significant increase in mean Bmax value parallel to a marked improvement of the depressive symptoms was found only in patients with SAD. No effect was observed either on mean Bmax value or on clinical symptoms in patients with non-SAD and on mean Bmax value in healthy volunteers.