The Internal Structure of the Nucleus geniculatus lateralis ventralis in the Avian Brain: A Golgi Study and Electron Microscopic Investigation

Different types of neurons in the ventral geniculate nucleus of the thalamus of chicks were visualised by Golgi impregnation. The dendritic tree of projection neurons branched in a sphere-like territory in both the ventral and middle areas of the lamina externa. The dendrites of projection neurons in the lamina interna descended into the lamina externa and entered both the ventral and middle dendritic areas. One or two dendrites of the lamina interna neurons also emitted branches that developed a dorsal sphere-like dendritic territory. Optic terminals labelled by Golgi impregnation or injection of biotinylated dextran amine were found in these dendritic territories gathered into groups. They established synapses in these areas (synaptic islands or fields without a glial sheath) with different dendritic profiles, and a few gamma-aminobutyric acid (GABA)-positive terminals synapsed with them. No glomerulus-like synaptic complexes ensheathed by glial processes were found. Optic terminals also contacted the stem dendrites of projection neurons and GABA-positive neuron cell bodies and dendrites. Numerous synapses established by both optic and GABA-positive terminals were found on the proximal dendritic stems of the lamina interna projection neurons.

[Treatment of pancreaticopleural fistulas]

Pancreaticopleural fistulas are rare but serious complications of chronic or recurrent inflammatory pancreatic disease. Massive unilateral or bilateral pleural effusion may occur in association with rupture of pancreatic duct or pseudocyst into the pleural cavity. In the past decade we have treated 10 patients with pancreaticopleural fistulas. Eight of them had a previous history of inflammatory pancreatic disease. Diagnosis was made by finding a markedly elevated amylase level (10 pts) in the pleural fluid. US and CT examination enabled the establishment of the diagnosis of pancreatic origin, showing chronic pancreatic (9 pts) and pancreatic pseudocyst (6 pts). Pancreaticopleural fistula was successfully demonstrated by ERCP in four patients. Initial treatment was non-operative using total parenteral or jejunal nutrition and multiple thoracocentesis or thoracic drainage. Anti-secretory octreotide therapy was used in all patients. This conservative treatment was successful in three patients (3/10). Septic complication (1 pt) and unsuccessful medical therapy (6 pts) recommended surgical intervention. Decompression procedure (4 pts) and resection (3 pts) were performed. Surgery was successful in all seven patients. We lost no patients and none of them required subsequent surgical treatment.

The ramifications and terminals of optic fibres in layers 2 and 3 of the avian optic tectum: a golgi and light and electron microscopic anterograde tracer study

The ramification patterns and terminals of optic fibres in layers 2 and 3 of the optic tectum were studied in Golgi-stained and immunolabelled preparations made from the brains of chicks and pigeons. The different neuronal structures of layers 2 and 3 were also examined. In Golgi preparations, two types of optic fibre were found both in chick and pigeon tectum according to their thickness and terminal branching patterns. The same types of optic fibres were also found to be present in the anterograde tracer experiments after iontophoresis of biotinylated dextran amine into the optic nerve. The varicose terminals of thin fibres mostly terminated on terminal dendritic sections of radiate and pyramidal-like neurons, contacting them on their apical dendrites. The medium-thick fibre terminals in layer 2 mainly established synapses with horizontally extending dendrites, which may therefore be contacts with inhibitory local circuit neurons. The medium-thick optic fibre bushy-like arborisation in layer 3 established synapses with larger dendrites and also stem dendrites. Their terminals formed groups with different dendritic profiles, some of which were partly covered by glial processes, and/or were located among converging dendrites. The presence of these glomerular-like synapses in layer 3 proves that the optic terminals in layer 3 also take part in the transmission of optic impulses to the nucleus rotundus.

Early effects of different cytostatic protocols for head and neck cancer on oncogene activation in animal experiments

In vivo investigations on oncogenes and onco-suppressor genes may provide new findings on the potential carcinogenic effects of various cytostatic protocols inducing secondary tumours of the head and neck. Further surgeries are often necessary due to regional recurrence after the Cisplatin-supplemented BVM (Bleomycin, Vincristine, Methotrexate) protocol in the treatment of human head and neck tumours. Our earlier studies have illustrated the carcinogenic and mutagenic potential of Cisplatin. The effect of Cisplatin on the alteration of different onco- and suppressor genes has also been proven. Our present study aimed at investigating the early effects of the BVM and the CFu (Cisplatin, 5-Fluorouracil) protocols on early oncogene and tumour suppressor gene expressions in mice. Body weight equivalent amounts of cytostatics were administered intraperitoneally to 6- to 8-week-old, inbred, female CBA/Ca mice. Twenty-four, 48 and 72 hours after the treatment, RNA was isolated from the target organs and the quantitative expression of c-myc, Ha-ras and p53 genes were examined. The protocols caused detectable changes. A "short-term" in vivo test, the 24-hour examination of gene expression, is suitable for detecting early effects of carcinogen exposure. The alterations of gene expression, caused by the Cisplatin-containing protocol, draw attention to the probable role of Cisplatin in the development of regional recurrence and to the possibility of prevention.

Mutational spectrum of the CHAC gene in patients with chorea-acanthocytosis

Chorea-acanthocytosis (ChAc) is an autosomal recessive neurological disorder whose characteristic features include hyperkinetic movements and abnormal red blood cell morphology. Mutations in the CHAC gene on 9q21 were recently found to cause chorea-acanthocytosis. CHAC encodes a large, novel protein with a yeast homologue implicated in protein sorting. In this study, all 73 exons plus flanking intronic sequence in CHAC were screened for mutations by denaturing high-performance liquid chromatography in 43 probands with ChAc. We identified 57 different mutations, 54 of which have not previously been reported, in 39 probands. The novel mutations comprise 15 nonsense, 22 insertion/deletion, 15 splice-site and two missense mutations and are distributed throughout the CHAC gene. Three mutations were found in multiple families within this or our previous study. The preponderance of mutations that are predicted to cause absence of gene product is consistent with the recessive inheritance of this disease. The high proportion of splice-site mutations found is probably a reflection of the large number of exons that comprise the CHAC gene. The CHAC protein product, chorein, appears to have a certain tolerance to amino-acid substitutions since only two out of nine substitutions described here appear to be pathogenic.

The intrinsic neuronal organisation of the nucleus of the basal optic root in the domestic chicken; a light and electron microscopic study using anterograde tracers and postembedding GABA-immunostaining

The intrinsic neuronal organisation in the nucleus of the basal optic root of chickens was investigated. The divergent connections with various areas and the functional complexity of the nucleus require a complex intrinsic structural arrangement. Therefore, an analysis of Golgi impregnated material, ultrastructure, GABA-immunocytochemistry and biotinylated dextran-amine anterograde tracer analysis of the nucleus was carried out. In the Golgi analysis, a characteristic dendritic ramification pattern of two types of putative projection neurons was observed. These neurons form dendritic nests with their overlapping dendritic terminal sections, that develop synaptic fields with the optic fibre terminals. These synaptic fields were confirmed by electron microscopy. GABA-immunopositive terminals synapse with distinct loci of the dendritic trees of projection neurons; they may therefore play an important role in the inhibitory-modulatory system of the nucleus of the basal optic root. The GABA-immunopositive terminals derive from small and/or elongated local circuit neurons which receive retinal afferents, and from myelinated fibres afferents to the nucleus of unknown origin.

Ultrastructural changes of the neuromuscular junction in reperfusion injury

Ischemia followed by reperfusion of skeletal muscle frequently takes place in trauma surgery. Anoxia followed by reoxygenation leads to reperfusion injury, which damages the involved tissues. However, no information is available about how the neuromuscular junction is affected by ischemia-reperfusion. Tourniquet ischemia of the left hind limb was applied in the anesthetized rat for 2 h. Reperfusion lasted for 2 and 24 h and for 1, 2 and 4 weeks. The extensor digitorum longus and the soleus muscles from both legs were prepared for electron-microscopic analyses. Morphological changes of the neuromuscular junction were investigated. In all cases only the nerve endings (terminals) were affected. The postsynaptic structures were not affected. Changes can be grouped in two categories: degeneration and recovery. Degeneration consisted of the loss of synaptic vesicles, disruption of the presynaptic membrane, degeneration of the mitochondria and the development of vacuoles. It was most severe at 24 h and was still present at 4 weeks of reperfusion. Recovery started at 1 week of reperfusion and lasted at least for 4 weeks. It consisted of the slow reappearance of synaptic vesicles and mitochondria, and restoration of the presynaptic membrane with active zones. Ultrastructure of the skeletal muscle fibers did not show pathological changes. The recovery of the structures may be regulated by the Schwann cells and also by the postsynaptic membrane which is not affected by 2 h of ischemia followed by reperfusion.

The ramification and connections of retinal fibres in layer 7 of the domestic chick optic tectum: a golgi impregnation, anterograde tracer and GABA-immunogold study

Layer 7 is one of the retinorecipient layers of the avian optic tectum. However, little information is available about the neuronal organization of this layer and its implications for visual function. Golgi impregnation was used to investigate the retinal input to and the neuronal architecture of layer 7 of the chick optic tectum, which forms a narrow band between the two cell-dense layers 6 and 8. Anterograde tracers were also used to investigate the afferent and efferent connections of layer 7, in both the light and the electron microscope, together with GABA immunogold labelling. Three types of radial neuron were defined according to the origin and course of their axons. The perikarya of these neurons were situated in tectal layers 10-11. The principal dendrites of these radial neurons ascended to the tectal surface and gave rise to dendritic side-branches in layer 7. These dendritic side-branches received asymmetric synapses from the terminations of retinal fibre arborisations. Type 2 radial neurons, whose axons arose from the deep pole of the perikaryon or occasionally from a basal dendrite, were shown to project to the nucleus isthmi pars magnocellularis, which has previously been demonstrated to be GABAergic and to project to glomerulus-like complexes in tectal layers 4-5. In these layers, the dendritic branches of layer 13 neurons that project to the nucleus rotundus have previously been shown to receive retinal fibre input. Therefore, the retinal input to layer 7 may be able to modulate the transmission of information to the visual thalamus, by way of a feed-back loop to layers 4-5 of the tectum involving the nucleus isthmi pars magnocellularis.

Oral health in liver transplant children administered cyclosporin A or tacrolimus

BACKGROUND

Immunosuppression by cyclosporin A (CsA) is associated with adverse side-effects, including nephrotoxicity, neurotoxicity and gingival overgrowth. Tacrolimus (TAC/FK506) is a new immunosuppressive agent, recently approved for use in solid-organ transplants. The mode of action of TAC is similar to that of CsA and the toxicity profile of CsA is duplicated by TAC. The effect of TAC on the gingival tissue is not yet conclusive.

SAMPLE

Gingival overgrowth was assessed in 30 liver transplant children, 20 boys and 10 girls, aged 2-19 years. Seventeen children (10 boys, seven girls) were on a CsA-based immunosuppressive regimen whereas 13 children (10 boys, three girls) were on TAC for at least 1 year (mean 4.3 +/- 2.7).

RESULTS

In the CsA group, 35% of children exhibited gingival overgrowth characterized by one or more units with increased sulcus probing depth (> or = 4 mm), i.e. pseudopockets. In contrast to the CsA group, none of the children in the TAC group exhibited gingival overgrowth. The occurrence of enamel hypoplasia was observed in 11 children (36%) and enamel opacities were found in 23 children (76%). Six of the 12 children (50%) with hyperbilirubinaemia biliary atresia exhibited a marked greenish discoloration of the teeth. Caries experience (dmft/DMFT) among these children was 2.0 +/- 2.8.

CONCLUSION

No difference in caries experience or enamel defect was observed between the CsA and TAC group.

A Better Enzyme to Cope with Cold

3-isopropylmalate dehydrogenase (IPMDH) from the psychrotrophic bacterium Vibrio sp. I5 has been expressed in Escherichia coli and purified. This cold-adapted enzyme is highly homologous with IPMDHs from other organisms, including mesophilic E. coli and thermophilic Thermus thermophilus bacteria. Its molecular properties are similar to these counterparts. Whereas the E. coli and T. thermophilus enzymes are hardly active at room temperature, the Vibrio IPMDH has reasonable activity below room temperature. The thermal stabilities, conformational flexibilities (hydrogen-deuterium exchange), and kinetic parameters of these enzymes were compared. The temperature dependence of the catalytic parameters of the three enzymes show similar but shifted profiles. The Vibrio IPMDH is a much better enzyme at 25 degrees C than its counterparts. With decreasing temperature i.e. with decreasing conformational flexibility, the specific activity reduces, as well; however, in the case of the Vibrio enzyme, the residual activity is still high enough for normal physiological operation of the organism. The cold-adaptation strategy in this case is achieved by creation of an extremely efficient enzyme, which has reduced but still sufficient activity at low temperature.

Frequency of the R3500Q mutation of the apolipoprotein B-100 gene in a sample screened clinically for familial hypercholesterolemia in Hungary

Familial hypercholesterolemia (FH) and familial defective apolipoprotein B-100 (FDB) cause early onset of coronary heart diseases (CHD). According to the recommendations of the international MEDPED program, we tried to find FH cases. We analyzed 73 FH probands and their 304 first-degree relatives. A total of 39 probands were found from the 21000 subjects screened (1:538) from family doctors' registers recording all citizens, while the remaining 34 were derived from screened patients from lipid clinics. In our FH probands, four cases of FDB (R3500Q mutation) were diagnosed with allele-specific PCR, and the mutation was also detectable in five cases out of seven living family members. In the remaining 69 FH families, 156 people were diagnosed clinically with FH, and 31.8% of the males (against 13% of the not clinically diagnosed FH males, P<0.01), and 32.4% of the females (against 13.5% of the not clinically diagnosed FH females, P<0.01) suffered from early onset CHD. The plasma total cholesterol level of the FDB patients, especially in the younger patients, was very close to normal values. Therefore, the FDB patients seem to be under-represented in this type of survey. Because FDB is one of the independent causes of early onset CHD, the R3500Q mutation should be considered in families with a high frequency of cardiovascular diseases.

Surgical closures of oropharyngocutaneous fistulas

Of the 146 patients undergoing surgery for oropharyngeal cancer in our institution, 12 (8.2 percent) developed fistulas. As a first line of therapy, conservative measures were used, which consisted of debridement, Xeroform gauze packing, and nasogastric feeding. Seven fistulas closed after conservative treatment. Of the five patients who required surgery for fistula closure, three had large (more than 20 mm) and two had mid-size (5- to 20-mm) fistulas. In all cases, internal flaps were prepared from the healthy viable tissues surrounding the fistula, and sternocleidomastoid-trapezius-platysma myocutaneous flaps were used for external closure. None of the closures failed, and we obtained good functional and aesthetic results.

Mechanism of volatile compound production during storage of sunflower Oil

Volatile compounds formed in the course of the thermal decomposition of hydroperoxides during storage of sunflower oil were analyzed by headspace solid-phase microextraction sampling followed by gas chromatographic separation and mass spectral detection. The determining role of alkoxyl radicals in the process has been proven by electron spin resonance spectroscopic measurements. On the basis of analytical results, the reaction networks and mechanisms were constructed by computer modeling to describe the formation of volatile products of radical decomposition of hydroperoxides. We established that off-flavor aliphatic aldehydes are originated from only the alkoxyl radicals derived from trigliceride of linoleic acid. To find a specific additive, which redirects the formation of these radicals toward production of more stable species, is suggested.

[Randomized study of cisplatin-based combination chemotherapy for the treatment of planocellular cancer of the head and neck region]

Between January 1996 and November 1998 38 patients were treated with induction chemotherapy. Patients were distributed in two randomized groups, 19-19 patients in each, receiving (group N) either bleomycin, vincristine and methotrexate (BVM) or the previous medication plus cisplatin (BVCM) chemotherapy (group C). Side effects were low and reversible during the treatments. The clinical regression rate (RR) of the cases was 87% including complete regression 24%. There was no difference between the two groups. There was no difference in the pathological macroscopic regression, however group C was better in microscopic regression. During the 27.5 months of average follow-up time, group N had a significantly better result in the tumor-free survival, with a lower rate of metastatic recidives (N/C = 2/9). There was no significant difference in the overall survival rate, due to the radical neck dissections of recidive metastases. According to our experience we recommend the use of cisplatin in conjunction with neck radiotherapy.

[Double flap reconstruction of extended facial defects]

The authors report the reconstruction of large facial defects remaining after resection of two advanced facial cancer cases. In both cases double flap closures were carried out. In the first case the internal flap was created from the remaining part of the oral mucosa membrane, while in the second a forearm fascio-cutan free flap was used. For external closure in both cases platysma based transpositional flaps were used, prepared from the neck. On the basis of excellent aesthetic results and safe applicability the authors recommend the more frequent use of this method.

Diagnostic test meal in childhood enteropathy using simultaneous carbohydrate and fat loading

The diagnostic value of a combined test meal consisting of glucose, D-xylose and dairy cream was studied in 230 infants and children with gastrointestinal symptoms. The simultaneous absorption of the three compounds was rated according to their serum concentrations at different times 0-240 min after intake and compared to the histological changes of jejunal biopsy specimens.

CONCLUSION

The results showed that the simultaneous loading test had higher specificity and sensitivity than D-xylose alone in patients with subtotal villous atrophy.

Fatal deterioration of neurological disease after orthotopic liver transplantation for valproic acid-induced liver damage

We describe a 12-year-old girl with an early onset neurologic disease of slow progressiveness and electro-encephalography showing epileptic activity. The girl developed fulminant liver failure 5 months after the start of valproic acid treatment. Repeated mitochondrial assays failed to prove a mitochondrial disorder, but muscle biopsies were slightly pathological. Liver histology indicated acute-on-chronic liver disease. Six weeks after a successful orthotopic liver transplantation her neurological condition deteriorated rapidly, soon leading to generalized cortical disease and death. Post-mortem brain examination showed advanced central nervous destruction. We suggest that this is a late-onset Huttenlocher variant of Alpers' syndrome, where fulminant liver failure can be triggered by valproic acid, and orthotopic liver transplantation can subsequently trigger a fatal neurologic deterioration. Our case illustrates that when a referral center receives a previously unknown patient with hepatocellular insufficiency, it might be impossible to differentiate between fulminant vs. acute-on-chronic liver failure, and the decision whether to perform a liver transplantation or not would become difficult.

Adaptive systems in speckle-pattern interferometry

The concept of adaptivity in television holography is discussed, and various realizations of adaptivity are presented. In one possible variation, functions of the components of the optical arrangement may be changed to adapt them to measurement conditions. An additional peculiarity of the technique is that reference waves are produced by holographically reconstructed virtual images. A method, believed to be new, is introduced for synthesizing the phase front of the master object beam that is produced by a simple holographic optical element and is used as a smooth or a speckled reference beam in the electronic speckle-pattern interferometer. An adaptive interferometer is presented as a measuring device for various measuring tasks. Selected applications are shown, demonstrating different aspects of adaptivity.

Direct connections between dendritic terminals of tectal ganglion cells and glutamate-positive terminals of presumed optic fibres in layers 4-5 of the optic tectum of Gallus domesticus. A light- and electron microscopic study

The principal afferent fibres of the avian optic tectum are the optic fibres of retinal origin. They terminate on the contralateral side, in the external layers (2-7) of the optic tectum (called optic layers) turning into these layers from the external surface. The terminal branchings of the optic fibres develop four densely innervated areas in layers 2, 3, 4-5 and 7. Their terminals are large and of various appearance in the different areas. In the middle third of the optic layer (in layers 4-5), thin dendritic terminal sections of tectal ganglion cells (according to Ramòn y Cajal) of layer 13 terminate into bunches. Phaseolus vulgaris lectin immunotracer corroborates these dendritic endings (further: dendritic terminals) of tectal ganglion cells. The direct connections between these dendritic terminals and the supposed optic fibres were studied under electron microscope and it was found that the large terminals of optic fibres containing round synaptic vesicles establish asymmetrical synapses with several dendritic profiles, among them Phaseolus lectin labelled dendritic terminals of ganglion cells. This result morphologically supports the former physiological observation of a direct synaptic transmission between optic fibres and ganglion cells of layer 13. In addition, on the dendritic terminals of ganglion cells, symmetrical synapses established by GABA-positive terminals were found. The optic terminals, the GABA-immunopositive terminals and the dendritic terminals of ganglion cells form complex synaptic units surrounded with glial sheath, and thus they establish glomerulus-like synaptic units. The size of the dendritic tree and the branching pattern of the dendrites of ganglion cells point to divergence and convergence in visual transmission.

[Comparison of various methods in the detection of Helicobacter pylori infection]

There are several possible methods to detect H. pylori in the gastric mucosa. The aim of our prospective study was to evaluate the diagnostic value of these tests and to define their place in the clinical practice. 109 (45 male, 64 female) patients who underwent upper GI endoscopy were included. Before endoscopy, whole blood was collected for serological test and 13C-UBT (13C-urea breath test) was performed. During endoscopy, multiple biopsies were collected from the antrum and corpus for the examination of H. pylori status by histology and rapid urease test. Patients with positive histology and a positive result of any other examinations, or--in case of negative histology--with two positive results of the remaining examinations were considered to be H. pylori-positive. 50 patients (46%) proved to be H. pylori-positive. Sensitivity and specificity, respectively, were as follows [in brackets: negative predictive value (NPV) and positive predictive value (PPV), respectively]: histology, 98% and 92% (98% and 91%); 13C-UBT, 93% and 98% (94% and 98%); rapid urease test, 83% and 100% (86% and 100%); serological examination, 86% and 74% (88% and 70%). The sensitivity and the clinical role of the methods used for the detection of H, pylori infection is different. Histology is the most reliable method if endoscopy in performed. The positive result of the rapid urease test is also of good diagnostic value. The 13C-UBT is the method of choice if no endoscopy is performed and the clarification of H. pylori status is necessary. This method can be useful to control the success of bacterium eradication as well. The serological examination provides instant result, therefore this method is proposed for screening and epidemiological studies.

[Detection of aneuploidy from gastrointestinal biopsy samples]

Aim of the present work was the development of a mechanic cell separation protocol for gastrointestinal biopsy analysis. Evaluation of the technique was performed on selected group of patients who underwent routine endoscopy. Routine gastrointestinal biopsies were obtained after informed consent. 23 gastric (6 healthy, 14 gastritis, 3 adenocarcinoma) and 15 colon samples (5 healthy, 7 colitis ulcerosa, 3 adenocarcinoma) were evaluated. The mechanic disruption of the biopsies was performed by Medimachine (DAKO, Denmark), a commercially available system using a 30 microns miner and a 30 microns mesh. The cell solution was centrifuged for 5 minutes by 250 g. The cells were fixed in paraformaldehide and stained by propidium iodide. The flow cytometry analysis was performed on a BD FacStar Plus flow cytometer. The DNA data were evaluated using the Winlist software. All of the preparations were appropriate for flow cytometric analysis. The coefficient of variation of the DNA histograms (n = 7) (CV mean +/- SD. 6.45% +/- 1.21) were acceptable for analysis. In the gastric biopsy samples aneuploidy was determined only in malignant cases. In four of the seven colitis ulcerosa samples and in one of the three adenocarcinoma aneploidy was found. The histologically healthy specimen were all diploid. Mechanic cell separation and disaggregation is a useful method for preparing fresh biopsy specimen for flow cytometry.