A re-analysis of NH4+ sorption on biochar: Have expectations been too high?

Sorption of nutrients such as NH₄⁺ is often quoted as a critical property of biochar, explaining its value as a soil amendment and a filter material. However, published values for NH₄⁺ sorption to biochar vary by more than 3 orders of magnitude, without consensus as to the source of this variability. This lack of understanding greatly limits our ability to use quantitative sorption measurements towards product design. Here, our objective was to conduct a quantitative analysis of the sources of variability, and infer which biochar traits are more favourable to high sorption capacity. To do so, we conducted a standardized remodelling exercise of published batch sorption studies using Langmuir sorption isotherm. We excluded studies presenting datasets that either could not be reconciled with the standard Langmuir sorption isotherm or generated clear outliers. Our analysis indicates that the magnitude of sorption capacity of unmodified biochar for NH₄⁺ is lower than previously reported, with a median of 4.2 mg NH₄⁺ g^-1 and a maximum reported sorption capacity of 22.8 mg NH₄⁺ g^-1. Activation resulted in a significant relative improvement in sorption capacity, but absolute improvements remain modest, with a maximum reported sorption of 27.56 mg NH₄⁺ g^-1 for an activated biochar. Methodology appeared to substantially impact sorption estimates, especially practices such as pH control of batch sorption solution and ash removal. Our results highlight some significant challenges in the quantification of NH₄⁺ sorption by biochar and our curated data set provides a potentially valuable scale against which future estimates can be assessed.

Screening and Ranking Methodology Applied to Biochars Aimed at Acidic and Calcareous Sandy Soil Improvement

The application of biochar (the by-product of biomass pyrolysis), as a soil amendment has been accepted as a sustainable solution to improve soil quality. The current study aims to establish a decision support tool for characterizing, ranking, and selecting biochars of different origins for soil improvement, thereby contributing to the development of a systematic approach, which lacks in the existing literature.The development of a Multi-Criteria Decision Support Approach applying a banded and weighted rating and scoring system allowed the selection and ranking of various biochars suitable for improving sandy soils before application. First, 14 selected, different biochar products (produced from industrial by-products, herbaceous, wood-based and manure-based feedstocks) were characterized with several physicochemical, biological and ecotoxicological methods taking into account both the technological and the environmental efficiency aspects of biochar utilization. Then, a system for the assessment and ranking of biochars for acidic, and calcareous neutral sandy soil improvement was developed, which could be flexibly adapted to different soil problems as well. Based on their performance in the tests, scores from (−5) to (+5) were assigned to each biochar. As a result, the grain husks and paper fiber sludge biochar was ranked as the most suitable for both acidic and neutral calcareous sandy soil improvement, with 55 and 43 scores, respectively (from the maximum 100). The applicability of this innovative multicriteria scoring-ranking system, as a tool for potential biochar users, was verified in microcosms and field-scale experiments, demonstrating the positive influence of this biochar on the acidic sandy soil.

Three new genera of the Teloschistaceae proved by three gene phylogeny

Three new for science genera, i.e.: Erichansenia S. Y. Kondr., Kärnefelt et A. Thell for the ‘Caloplaca’ epithallina group of the subfamily Xanthorioideae, as well as Lendemeriella S. Y. Kondr. for the Caloplaca reptans group, and Pisutiella S. Y. Kondr., L. Lőkös et E. Farkas for the Caloplaca conversa group of the subfamily Caloplacoideae of the Teloschistaceae, are described on the basis of results of the three gene phylogeny of the Teloschistaceae based on nrITS, nrLSU and mtSSU sequences.

Twenty-seven new combinations, i.e.: Erichansenia epithallina (for Caloplaca epithallina Lynge), Erichansenia cryodesertorum (for Shackletonia cryodesertorum Garrido-Ben., Søchting et Pérez-Ort.), Erichansenia sauronii (for Caloplaca sauronii Søchting et Øvstedal), Fauriea mandshuriaensis (for Caloplaca mandshuriaensis S. Y. Kondr., L. Lőkös et J.-S. Hur), Fauriea trassii (for Caloplaca trassii Galanina et S. Y. Kondr.), Lendemeriella borealis (for Lecanora pyracea f. borealis Vain.), Lendemeriella dakotensis (for Caloplaca dakotensis Wetmore), Lendemeriella exsecuta (for Lecanora exsecuta Nyl.), Lendemeriella lucifuga (for Caloplaca lucifuga G. Thor), Lendemeriella nivalis (for Zeora nivalis Körb.), Lendemeriella reptans (for Caloplaca reptans Lendemer et B. P. Hodk.), Lendemeriella sorocarpa (for Placodium sorocarpum Vain.), Lendemeriella tornoensis (for Caloplaca tornoensis H. Magn.), Pisutiella congrediens (for Lecanora congrediens Nyl.), Pisutiella conversa (for Callopisma conversum Kremp.), Pisutiella furax (for Caloplaca furax Egea et Llimona), Pisutiella grimmiae (for Lecanora grimmiae Nyl.), Pisutiella ivanpisutii (for Caloplaca ivanpisutii S. Y. Kondr., L. Lőkös et Hur), Pisutiella phaeothamnos (for Caloplaca phaeothamnos K. Kalb et J. Poelt), Pyrenodesmia aetnensis (for Caloplaca aetnensis B. de Lesd.), Pyrenodesmia albolutescens (for Lecanora albolutescens Nyl.), Pyrenodesmia aractina (for Parmelia aractina Fr.), Pyrenodesmia atroflava (for Lecidea atroflava Turner), Pyrenodesmia bicolor (for Caloplaca bicolor H. Magn.), Pyrenodesmia molariformis (for Caloplaca molariformis Frolov, Vondrák, Nadyeina et Khodos.), Pyrenodesmia neotaurica (for Caloplaca neotaurica Vondrák, Khodos., Arup et Søchting), Pyrenodesmia peliophylla (for Placodium peliophyllum Tuck.) are proposed based on results from a combined phylogenetic analysis using nrITS, nrLSU and mtSSU gene sequences.

Immunohistochemistry and Reverse Transcriptase Polymerase Chain Reaction on Sentinel Lymph Nodes can Improve the Accuracy of Nodal Staging in Breast Cancer Patients

In this study the nodal staging sensitivity of sentinel lymph node biopsy (SLNB) with detailed pathological and molecular biological examination has been investigated and compared to that of axillary lymph node dissection (ALND) with routine histological evaluation. Sentinel lymph nodes (SLNs) were removed by the dual-agent injection technique in 68 patients with primary, clinically node-negative breast cancer. Forty-seven patients had negative SLNs according to hematoxylin and eosin (H&E) staining. These H&E-negative SLNs were serially sectioned and examined at 250 μm levels by anticytokeratin immunohistochemistry (IHC). In 14 patients the SLNs were also investigated by cytokeratin 20 (CK20) reverse transcriptase polymerase chain reaction (RT-PCR). SLNB with IHC increased the node-positive rate by 26% (by 40% in tumors less than or equal to 2 cm in size (pT1) and by 9% in tumors more than 2 cm but less than or equal to 5 cm in size (pT2)). The sensitivity of SLNB with IHC was superior to that of ALND with routine histology in pT1 tumors and identical in pT2 tumors. The concordance between histology and RT-PCR was only 21%, and in two of three cases with positive histological results RT-PCR was negative. In conclusion, SLNB with detailed pathological and/or molecular biological evaluation can improve the sensitivity of regional staging. ALND can probably be abandoned in patients with pT1 SLN-negative breast cancer. Further prospective studies are required to determine the clinical significance of these detailed SLN evaluation techniques, but at present these methods are still investigational.

Ischemia-induced depolarizations and associated hemodynamic responses in incomplete global forebrain ischemia in rats

Spontaneous depolarizations around the core are a consistent feature of focal cerebral ischemia, but the associated regional hemodynamic changes are heterogeneous. We determined how the features of depolarizations relate to subsequent cerebral blood flow (CBF) changes in global forebrain ischemia. Forebrain ischemia was produced in halothane-anesthetized rats (n=13) by common carotid artery occlusion and hypovolemic hypotension. Mean arterial blood pressure (MABP) was monitored via a femoral catheter. Specific illuminations allowed the capture of image sequences through a cranial window to visualize: changes in membrane potential (voltage-sensitive dye method); CBF (laser speckle contrast imaging); cerebral blood volume (intrinsic optical signal, IOS at 540-550nm); and hemoglobin deoxygenation (IOS at 620-640nm). A depolarization occurred (n=9) when CBF fell below 43.4±5% of control (41±4mmHg MABP), and propagated with a distinct wave front at a rate of 2.8mm/min. Depolarizations were either persistent (n=4), intermediate (n=3) or short, transient depolarization (n=2). Persistent and intermediate depolarizations were associated with sustained hypoperfusion (-11.7±5.1%) and transient hypoperfusion (-17.4±5.2, relative to CBF before depolarization). Short, transient depolarizations did not generate clear CBF responses. Depolarizations during incomplete global ischemia occurred at the lower limit of CBF autoregulation, propagated similar to spreading depolarization (SD), and the hemodynamic responses indicated inverse neurovascular coupling. Similar to SDs associated with focal stroke, the propagating event can be persistent or transient.

Effect of beta-sitosterol concentration and high pressure homogenization on the chlorhexidine release from vesicular gels

Previous studies have confirmed that the phase transition of vesicular gels of hydrogenated phospholipids to the less ordered fluid vesicular state was induced by the increase of the beta-sitosterol ratio in the whole gel system and consequently in the lipid bilayer. The purpose of the present study was to evaluate the influence of the beta-sitosterol portion in the lipid bilayer and the effect of high pressure homogenization on the structural characteristics of the prepared gel systems. In addition the influence of beta-sitosterol on the consequent chlorhexidine release from the obtained vesicles and liposomes was also examined. Lipid mixtures were prepared from different molar ratios of lecithin:sterol components (90:10-65:35 mol%). The obtained mixtures were hydrated with the aqueous solution of chlorhexidine digluconate in order to achieve a 30% (w/w) final concentration of the lipid mixtures and a 4% (w/w) concentration of the drug. One portion of the resultant multilamellar vesicles was homogenized by using high pressure. To characterize the homogenized and non-homogenized systems, transmission electron microscopy of the freeze-fractured samples and differential scanning calorimetry (DSC) were carried out. A vertical type diffusion cell was applied to determine the amount of released chlorhexidine digluconate. Along with the increase in beta-sitosterol concentration, the fluidity of the membrane as well as its permeability also increased. The increased permeability--caused by the higher beta-sitosterol concentration--and the high pressure homogenization, which increased the dispersity and therefore the surface area, enabled a higher amount of chlorhexidine to be released. The increase of drug release was more pronounced in the case of samples prepared with high pressure homogenization.

Structural and functional MRI following 4-aminopyridine-induced seizures: a comparative imaging and anatomical study

Structural and functional MRI was used in conjunction with computerized electron microscopy morphometry to study changes 2 h, 24 h and 3 days after 4-aminopyridine-induced seizures lasting 2 h in rats. T2 (relaxation time) values showed changes throughout the cerebral cortex, hippocampus, amygdala and medial thalamus, with a different temporal progression, showing a complete recovery only after 3 days. Two hours after seizures, the apparent diffusion coefficient was decreased throughout the brain compared to control animals, and a further decrease was evident 24 h after seizures. This was followed by a complete recovery at 3 days post-seizures. Functional MRI was performed using regional cerebral blood volume (rCBV) maps. The rCBV was increased shortly after convulsions (2 h) in all structures investigated, with a significant return to baseline values in the parietal cortex and hippocampus, but not in the medial thalamic nuclei, 24 h after seizure onset. No rCBV alterations were detected 3 days after seizures. Electron microscopy of tissue samples of parietal neocortex and hippocampus revealed prominent astrocytic swelling 2 h post-convulsions which decreased thereafter gradually. In conclusion, this experiment reports for the first time structural and functional brain alterations, lasting several hours, in 4-aminopyridine-treated rats after seizure onset. MRI approach combined with histological and ultrastructural analysis provided a clarification of the mechanisms involved in the brain acute response to ictal activity.

Study on the transfer of components of Aetheroleum carvi and Aetheroleum foeniculi oils

The transfer through a membrane of the main organic components and mineral elements of Carum carvi and Foeniculum vulgare volatile oils was studied. The transfer was studied from buffer solution pH 1.1 (stomach) and pH 6.5 (intestine) to pH 7.5 (plasma) in a Sartorius model. The transferred components were measured by GC-MS for volatile components and ICP-OES for inorganic elements. The main components (trans-anethole and fenchone from F. vulgare, carvone and D-limonene from C. carvi), as well as some mineral elements (Ca, Mg, S, Zn), transferred through the membrane.

Effect of β-sitosterol on the characteristics of vesicular gels containing chlorhexidine

Previous studies confirm that beta-sitosterol is very effective in altering the molecular packing of soybean lecithin bilayers even more than the cholesterol. The primary aim of the present study was to evaluate the influence of the beta-sitosterol portion in the lipid bilayer on the physical-chemical characteristics of the prepared gel systems, and its influence on the consequent drug release from the liposomes obtained from vesicular phospholipid gels (VPG-s) by redispersion. VPG-s were prepared of different molar ratios of lecithin:sterol components (10:90-35:65 mol%). The mixture was hydrated with the aqueous solution of chlorhexidin digluconate in order to achieve 30% (w/w) final concentration of the lipid mixtures and 4% (w/w) concentration of the drug in each homogenized VPG sample. To characterize the obtained VPG systems optical microscopic examinations using polarized light, differential scanning calorimetry (DSC), photon correlation spectroscopy (PCS), and dynamic surface tension measurements were carried out. Vertical type diffusion cell was applied to determine the amount of released chlorhexidine digluconate. As a result of the surface tension-decreasing effect of beta-sitosterol, the membrane deformability and the dispersity of the system increased. The increased dispersity and fluidity significantly increased the extent of released chlorhexidine from the vesicles.

Synovial fluid exoglycosidases are predictors of rheumatoid arthritis and are effective in cartilage glycosaminoglycan depletion

OBJECTIVE

To analyze enzymes involved in joint damage by simultaneous investigation of glycosidases and matrix metalloproteinases (MMPs) in patients with various joint diseases.

METHODS

Activities of glycosidases (beta-D-glucuronidase, beta-D-N-acetyl-glucosaminidase, beta-D-N-acetyl-galactosaminidase, beta-D-galactosidase, and alpha-D-mannosidase) were tested at an acidic pH as well as at the original pH of the synovial fluid (SF) samples in parallel with activities of MMP-1 and MMP-9.

RESULTS

Patients with rheumatoid arthritis (RA) were characterized by significantly elevated activities of beta-D-glucuronidase and beta-D-N-acetyl-glucosaminidase in SF compared with patients with osteoarthritis, seronegative spondylarthritis, or acute sports injury. To select the best predictor for distinguishing among patient groups, a stepwise logistic regression analysis was performed; the strongest association was found to be between RA and beta-D-glucuronidase/beta-D-N-acetyl-glucosaminidase activities (measured at the pH of the SF). Further, a significant correlation was observed between the activity of SF beta-D-N-acetyl-glucosaminidase and the level of rheumatoid factor. In vitro digestion of human hyaline cartilage samples revealed that the dominant glycosidases, alone or in combination with MMPs, proved to be effective in depleting glycosaminoglycans (GAGs) from cartilage.

CONCLUSION

These results suggest that exoglycosidases, which are present in the SF of RA patients, may contribute to the depletion of GAGs from cartilage and thereby facilitate the invasion of synovial cells and their attachment to cartilage in RA.

Inguinal sentinel lymph node biopsy for staging anal cancer

BACKGROUND AND AIMS

The optimal treatment of clinically negative inguinal lymph nodes in patients with primary anal cancer has not yet been clearly defined. The presence of metastases in the inguinal lymph nodes is an adverse prognostic factor for anal cancer. In the present study the feasibility of sentinel lymph node biopsy (SLNB) for staging anal cancer was investigated.

PATIENTS AND METHODS

From September 1999 to March 2002, 8 patients with biopsy proven primary anal cancer underwent lymphoscintigraphy and dual-agent guided inguinal SLNB for nodal staging before starting multimodality treatment.

RESULTS

Inguinal SLNB was successful in all 8 patients (13 groins). A total of 20 hot and blue SLNs (mean 1,5 (1-2) per groins) were removed. In 2 patients (25%) the SLN was positive for metastasis.

CONCLUSIONS

Lymphoscintigraphy followed by dual-agent guided inguinal SLNB is technically feasible for staging patients with primary anal cancer. The detection of metastases in the removed sentinel lymph node(s) may alter the treatment and thus may improve the locoregional control and overall survival of these patients.

Elevated levels of synovial fluid antibodies reactive with the small proteoglycans biglycan and decorin in patients with rheumatoid arthritis or other joint diseases

OBJECTIVES

To determine whether patients with rheumatoid arthritis (RA) express humoral immunity to the small proteoglycans biglycan and decorin and to compare the response to that of patients suffering from other joint diseases.

METHODS

Serum and synovial fluid IgG and IgM antibody levels were determined by enzyme-linked immunosorbent assay. Antibodies to biglycan and decorin as well as to other known and extensively investigated cartilage matrix components such as type II collagen, aggrecan and fibronectin were investigated. Patients suffering from RA, osteoarthritis (OA), psoriatic arthritis and other seronegative spondylarthropathies were included in the study. Correlation between antibody levels and clinical/laboratory parameters was determined.

RESULTS

Patients with RA expressed an increased humoral immunity to biglycan, while patients with seronegative spondylarthropathies displayed elevated decorin-specific synovial antibody levels compared with OA patients.

CONCLUSION

These results indicate a significantly higher immunity to small proteoglycans in RA and seronegative spondylarthropathies than in OA suggesting a possible involvement in the pathogenesis of inflammatory rheumatic diseases.

[Laparoscopic resection of the rectum]

Improving the laparoscopic equipments and the techniques have spreaded the repertoire of the laparoscopic procedures. In the beginning, it was performed the laparoscopic-assisted resection of the rectum, and later was performed the entire laparoscopic procedures on the colon. It had presented a patient, 71 years old man with diagnosis of the adenocarcinoma recti. After preoperately prepare carried out the laparoscopic procedure with T-T anastomosis by EEA stapler. We presented the first case of the laparoscopical performed resection of the rectum with desire to show possibilities and advantages of the laparoscopic surgery in the relation with conventional surgery and with hope that this techniques would be found the application in our land.

Penicillin productivity and glutathione-dependent detoxification of phenylacetic and phenoxyacetic acids in Penicillium chrysogenum

Both toxicity and penicillin productivity of the hydroxylated derivatives of phenylacetic acid (PA) and phenoxyacetic acid (POA) were highly dependent on the position of hydroxylation on the aromatic ring in Penicillium chrysogenum. Hydroxylation at position 2 diminished penicillin production but the compounds retained most of their toxicity. On the other hand, hydroxylation at position 4 resulted in barely toxic derivatives with still significant penicillin productivity. 3-Hydroxy-PA was a weak side-chain precursor with considerably reduced toxicity. The activity of the glutathione-dependent detoxification pathway correlated well with the toxicity of the compounds but there was no correlation between acidity, toxicity and penicillin productivity.

[Examination of liquid crystalline gel systems containing chlorhexidine on the structure and the drug release]

The aim of the thesis was to examine liquid crystalline gel systems as novel, locally applied drug delivery systems. For developing liquid crystalline vehicle, different ratio of Synperonic A7--water mixtures was prepared. Chlorhexidine, chlorhexidine acetate and chlorhexidine gluconate were used as model drugs. Liquid crystalline structure, drug release and drug release kinetic of the samples were studied at increasing surfactant concentration and the effect of the different drugs on the physicochemical properties of the samples and on the membrane transport was examined. For the analysis of the prepared liquid crystalline systems polarising microscopy, rheology test, differential scanning calorimetry, small-angle neutron scattering and transmission electron microscopy were carried out. The drug release and membrane transport experiments were performed by Franz type vertical diffusion cell and Sartorius Resorptionsmodell apparatus. According to our results liquid crystalline vehicles of lamellar and hexagonal structure formed by increasing the surfactant concentration. The drug release studies indicated, that the kinetic of the release strongly depend on the liquid crystalline structure, zero order release occurs from hexagonal structures and anomalous transport occurs from lamellar structures. The addition of chlorhexidine species to the systems modified the structure of the liquid crystalline system. As a results of liquid crystal-drug interaction the solubility of chlorhexidine base and its diffusion through lipophilic membranes increased in comparison with those of the chlorhexidine salts.

Cerebral microvascular pathology in aging and Alzheimer's disease

The aging of the central nervous system and the development of incapacitating neurological diseases like Alzheimer's disease (AD) are generally associated with a wide range of histological and pathophysiological changes eventually leading to a compromised cognitive status. Although the diverse triggers of the neurodegenerative processes and their interactions are still the topic of extensive debate, the possible contribution of cerebrovascular deficiencies has been vigorously promoted in recent years. Various forms of cerebrovascular insufficiency such as reduced blood supply to the brain or disrupted microvascular integrity in cortical regions may occupy an initiating or intermediate position in the chain of events ending with cognitive failure. When, for example, vasoconstriction takes over a dominating role in the cerebral vessels, the perfusion rate of the brain can considerably decrease causing directly or through structural vascular damage a drop in cerebral glucose utilization. Consequently, cerebral metabolism can suffer a setback leading to neuronal damage and a concomitant suboptimal cognitive capacity. The present review focuses on the microvascular aspects of neurodegenerative processes in aging and AD with special attention to cerebral blood flow, neural metabolic changes and the abnormalities in microvascular ultrastructure. In this context, a few of the specific triggers leading to the prominent cerebrovascular pathology, as well as the potential neurological outcome of the compromised cerebral microvascular system are also going to be touched upon to a certain extent, without aiming at total comprehensiveness. Finally, a set of animal models are going to be presented that are frequently used to uncover the functional relationship between cerebrovascular factors and the damage to neural networks.

Calcium antagonists decrease capillary wall damage in aging hypertensive rat brain

Chronic hypertension during aging is a serious threat to the cerebral vasculature. The larger brain arteries can react to hypertension with an abnormal wall thickening, a loss of elasticity and a narrowed lumen. However, little is known about the hypertension-induced alterations of cerebral capillaries. The present study describes ultrastructural alterations of the cerebrocortical capillary wall, such as thickening and collagen accumulation in the basement membrane of aging spontaneously hypertensive stroke-prone rats. The ratio of cortical capillaries with such vascular pathology occurred significantly more frequently in hypertensive animals. Nimodipine and nifedipine are potential drugs to decrease blood pressure in hypertension but their beneficial effects in experimental studies reach beyond the control of blood pressure. Nimodipine and nifedipine can alleviate ischemia-related symptoms and improve cognition. These drugs differ in that nifedipine, but not nimodipine reduces blood pressure at the here-used concentration while both drugs can penetrate the blood-brain barrier. Here we show that chronic treatment of aging hypertensive stroke-prone rats with nimodipine or nifedipine could preserve microvascular integrity in the cerebral cortex.

[Oncocytic carcinoid tumor of the lung]

An elderly female patient was admitted and operated on for a lesion in the upper lobe of the right lung. After lobectomy the patient has recovered without complications. Histology proved oncocyter carcinoid tumour. This neuro-endocrine tumour is a rarity in the lungs with less than forty cases reported in the reviewed literature. This is the first case reported in Hungary.

Influence of chlorhexidine species on the liquid crystalline structure of vehicle

The aim of this study was to investigate the influence of three chlorhexidine species, chlorhexidine base and its salts (diacetate and digluconate), on the physico-chemical features of liquid crystalline systems and on drug transport through lipophilic membranes. Nonionic surfactant, Synperonic A7 (PEG(7)-C(13--15)) was selected for the preparation of the liquid crystalline systems. Mixtures of different ratios of Synperonic A7 and water were prepared. The liquid crystalline systems were characterized using polarizing microscopy, small-angle neutron scattering and transmission electron microscopy. Membrane transport was also examined. The addition of chlorhexidine species to the liquid crystalline system modified the structure of the liquid crystalline system. As a result of liquid crystal--drug interaction, the solubility of chlorhexidine base and its diffusion through lipophilic membranes increased in comparison with those of the chlorhexidine salts.

Interaction between iron(II) and hydroxamic acids: oxidation of iron(II) to iron(III) by desferrioxamine B under anaerobic conditions

Interaction between iron(II) and acetohydroxamic acid (Aha), alpha-alaninehydroxamic acid (alpha-Alaha), beta-alaninehydroxamic acid (beta-Alaha), hexanedioic acid bis(3-hydroxycarbamoyl-methyl)amide (Dha) or desferrioxamine B (DFB) under anaerobic conditions was studied by pH-metric and UV-Visible spectrophotometric methods. The stability constants of complexes formed with Aha, alpha-Alaha, beta-Alaha and Dha were calculated and turned out to be much lower than those of the corresponding iron(II) complexes. Stability constants of the iron(II)-hydroxamate complexes are compared with those of other divalent 3d-block metal ions and the Irving-Williams series of stabilities was found to be observed. Above pH 4, in the reactions between iron(II) and desferrioxamine B, the oxidation of the metal ion to iron(III) by the ligand was found. The overall reaction that resulted in the formation of the tris-hydroxamato complex [Fe(HDFB)]+ and monoamide derivative of DFB at pH 6 is: 2Fe2+ + 3H4DFB+ = 2[Fe(HDFB)]+ + H3DFB-monoamide+ + H2O + 4H+. Based on these results, the conclusion is that desferrioxamine B can uptake iron in iron(III) form under anaerobic conditions.

[Feasibility and accuracy of the combined radioisotope and blue-dye guided sentinel lymph node biopsy in breast cancer]

Sentinel lymph node biopsy is a minimally invasive operation for staging regional lymph nodes in breast cancer. This method was introduced in the last decade. However there are some remaining questions regarding labelling, surgical technique, indications, and the pathological examination of the removed sentinel lymph nodes which have to be answered before can be introduced as the routine clinical practice. 98 patients with primary breast cancer underwent double guided (radioisotope and blue-dye) sentinel lymph node biopsy in our department during a surgical feasibility study between December 1997 and February 2000. The operation was successful in 92 patients (94%). False negative rate, sensitivity and accuracy were 15%, 85% and 95% retrospectively. During the learning curve the success rate improved from 83% to 99%, the sensitivity from 79% to 89% and the accuracy from 88% to 97% and the false negative rate decreased from 21% to 11%. In T1 tumors the false negative rate and accuracy were 6% and 98%, while in T2 tumors these were 24% and 86%. Application of a larger particle sized colloid (200-600 nm), subareolar injection and next day operation technique had no effects on the results. Double guided sentinel lymph node biopsy is a sensitive surgical staging procedure which accurately predicts the lymph node status in T1 breast tumors. The technique used by us is easy to reproduce, and learn and is beneficial in technical and radiation protection aspects.

Pathological features of cerebral cortical capillaries are doubled in Alzheimer's disease and Parkinson's disease

Cerebral capillaries represent a major interface between the general circulation and the central nervous system and are responsible for sufficient and selective nutrient transport to the brain. Structural damage or dysfunctioning carrier systems of such an active barrier leads to compromised nutrient trafficking. Subsequently, a decreased nutrient availability in the neural tissue may contribute to hampered neuronal metabolism, hence to behavioral and cognitive functional deficiencies. Here we focus on the ultrastructural abnormalities of cerebral microvessels in Alzheimer's disease (AD: n = 5) and Parkinson's disease (PD; n = 10). The capillary microanatomy in samples from the cingulate cortex was investigated by electron microscopy and severe damage to the vessel walls was observed. Characteristic pathological changes including capillary basement membrane thickening and collagen accumulation in the basement membrane were enhanced in both AD and PD. The incidence of capillaries with basement membrane deposits was two times higher in AD and PD than in age-matched controls. Degenerative pericytes in all groups appeared at a similar frequency. The data indicate that basement membrane deposits, as opposed to pericytic degeneration, represent an important pathological feature of AD and PD and suggest that capillary dysfunction may play a causal role in the development of these two major neurodegenerative diseases.

Enzymatic synthesis of fucose-containing disaccharides employing the partially purified alpha-L-fucosidase from Penicillium multicolor

The alpha-L-Fucp-(1 --> 3)-D-GlcpNAc disaccharide structure is a vital core unit of the oligosaccharide components of glycoconjugates isolated from human milk and blood group substances. Alpha-L-Fucosidase from Penicillium multicolor catalyses the transfer of L-fucose from donor structures such as alpha-L-FucpOpNP and alpha-L-FucpF to various GlcpNAc derivatives and Glcp, forming alpha-(1 --> 3) linkages. The synthesis of several biologically relevant disaccharides including alpha-L-Fucp-(1 --> 3)-alpha-D-GlcpNAcOMe, alpha-L-Fucp-(1 --> 3)-alpha-D-GlcpNAcOAll, alpha-L-Fucp-(1 --> 3)-beta-D-GlcpNAcOAll, alpha-L-Fucp-(1 --> 3)-D-GlcpNAc and alpha-L-Fucp-(1 --> 3)-D-Glcp has been achieved in up to 34% yields by application of this enzyme.

Metal complexes of salicylhydroxamic acid (H2Sha), anthranilic hydroxamic acid and benzohydroxamic acid. Crystal and molecular structure of [Cu(phen)2(Cl)]Cl x H2Sha, a model for a peroxidase-inhibitor complex

Stability constants of iron(III), copper(II), nickel(II) and zinc(II) complexes of salicylhydroxamic acid (H2Sha), anthranilic hydroxamic acid (HAha) and benzohydroxamic acid (HBha) have been determined at 25.0 degrees C, I=0.2 mol dm(-3) KCl in aqueous solution. The complex stability order, iron(III) >> copper(II) > nickel(II) approximately = zinc(II) was observed whilst complexes of H2Sha were found to be more stable than those of the other two ligands. In the preparation of ternary metal ion complexes of these ligands and 1,10-phenanthroline (phen) the crystalline complex [Cu(phen)2(Cl)]Cl x H2Sha was obtained and its crystal structure determined. This complex is a model for hydroxamate-peroxidase inhibitor interactions.

Similar ultrastructural breakdown of cerebrocortical capillaries in Alzheimer's disease, Parkinson's disease, and experimental hypertension. What is the functional link?

The brain, as an intensely active organ, is highly dependent on a sufficient nutrient and oxygen availability in order to reach its optimal working capacity. It is well known that the vital supply of energy substrates is provided by the circulatory system, which splits up into a fine, terminal capillary network in target tissues. These capillaries are considered as important sites, since the actual nutrient trafficking takes place through their walls. That is why an intact, preserved structure of the microvessels is crucial to fulfill their function. Since the brain is known to be particularly vulnerable to suboptimal oxygen and glucose delivery, the intact morphology of capillaries is of paramount importance. Several observations have indicated that the cerebral capillary ultrastructure is damaged in Alzheimer's disease (AD). Curiously, the regional cerebral blood flow of AD patients is also significantly lower than in age-matched control individuals. Based on these data, it has been suggested that the decreased blood supply and the cerebrovascular alterations contribute to the development of dementia. However, we have observed similar capillary damage in Parkinson's disease patients and chronically hypertensive rats in addition to AD cases, as presented here. These findings indicate that cerebral capillary damage is not exclusive for AD but occurs under other neurodegenerative disorders and hypertension, as well. We hypothesize that ultrastructural abnormalities of cerebral capillaries are causally related to decreased cerebral blood flow and create a condition that favors neurodegenerative mechanisms including the development of dementia.

[Initial experiences with sentinel lymph node biopsy in malignant melanoma]

Elective versus therapeutic lymph node dissection has been a controversial field of the surgical treatment of cutaneous malignant melanoma for more than two decades. The identification and biopsy of the sentinel lymph node in different solid malignancies has become feasible by the method described by Morton in 1992. The sentinel lymph node is the first tumor draining lymph node in the regional lymph node basin. If metastasis is not proven in the sentinel node by detailed histological study those are unlikely in other regional lymph nodes and formal lymph node dissection can be omitted. Patients undergoing surgery for primary cutaneous (intermediate or high risk) melanoma have been initiated in this feasibility study. Of the 40 patients the sentinel lymph node biopsy was unsuccessful in two and at least one positive sentinel lymph node was found in nine patients. The duration of the procedure is between five and 15 minutes. After this feasibility study further prospective and randomized studies are projected.

Some factors affecting metal ion-monohydroxamate interactions in aqueous solution

The chelating properties exhibited by a series of monohydroxamic acids (propanohydroxamic acid (Pha), hexanohydroxamic acid (Hha), benzohydroxamic acid (Bha), N-methyl-acetohydroxamic acid (MAha), N-phenyl-acetohydroxamic acid (PhAha) and 2-hydroxypyridine-N-oxide (PYRha)) towards copper(II), nickel(II), zinc(II), calcium(II), magnesium(II) and aluminium(III) ions were studied by pH-metric, spectrophotometric and, in one case, by 27Al NMR methods. The results were compared with the corresponding data for metal ion-acetohydroxamate (Aha) and metal ion-desferrioxamine B (DFB) complexes. Changes of the substituents either on the carbon or on the nitrogen of the hydroxamate moiety caused a measurable effect on the chelate stability only in the case of aluminium(III) complexes. The aromatic derivative, PYRha, formed significantly more stable complexes than expected on the basis of the ligand basicity. The higher complex-forming ability of DFB compared to monohydroxamic acids diminishes in the case of the largest calcium(II) ion.

Brain Iron and Zinc Contents of German Patients with Alzheimer Disease

Our first project aimed to determine the average values of Fe and Zn in normal German human brain (5 individuals, 10 brain parts). Determinations were carried out by instrumental neutron activation analysis in Berlin. Quality control measurements were performed using National Institute of Standard Technology standard reference materials. The present results show non-homogeneous distribution of Fe and Zn in normal human brain. Our second goal was to study the possible elemental concentration changes in German patients with Alzheimer disease (5 subjects, 10 brain regions). Fe and Zn values are found to be significantly changed in some AD brain regions compared to the controls. Another object of this work was to extend the method for the determination of elemental concentration not only in whole brain samples (high fat content) but - applying two types of solvent extraction - in lipid fraction and in brain tissue without lipid.

Are Alzheimer's disease, hypertension, and cerebrocapillary damage related?

Alzheimer's disease (AD) patients are often subject to vascular dysfunction besides their specific CNS pathology, which warrants further examination of the interaction between vascular factors and the development of dementia. The association of decreased cerebral blood flow (CBF) or hypertension with AD has been a target of growing interest. Parallel with physiological changes, the cerebral capillaries in AD are also prone to degenerative processes. The microvascular abnormalities that are the result of such degeneration may be the morphological correlates of the vascular pathophysiology pointing to a compromised nutrient transport through the capillaries. Animal models have been developed to study the consequences of hypertension and reduced CBF. Spontaneously hypertensive rats are widely used in hypertension research whereas ligation of the carotid arteries has become a method to produce cerebral hypoperfusion. Based on these models, we propose a relationship between hypertension, cerebral hypoperfusion, cerebral capillary malformation and cognitive decline as it occurs in AD. We suggest that the above conditions are functionally related and can contribute to the progression of AD.

The effect of liquid crystalline structure on chlorhexidine diacetate release

The aim of this study was to examine different liquid crystalline preparations containing chlorhexidine diacetate and to find connection between their structure and the kinetic of drug release. Nonionic surfactant, Synperonic A7 (PEG(7)-C(13-15)) was selected for the preparation of the examined liquid crystalline systems. Mixtures of different ratios of Synperonic A7 and water were produced. By increasing the water content of the systems, lamellar and hexagonal liquid crystal structures were observed. For the analysis of the prepared liquid crystalline systems polarising microscopy, rheology study, differential scanning calorimetry and dynamic swelling tests were carried out. The chlorhexidine diacetate release was examined by Franz-type vertical diffusion cell apparatus. The chlorhexidine diacetate release from hexagonal liquid crystalline preparations was characterised by zero-order release kinetics, while the drug release from lamellar liquid crystalline systems was described by anomalous (non-Fickian) transport. The results indicate that the drug release kinetic is strongly dependent on the liquid crystalline structure.

Lessons learned from the initial 100 patient experience with sentinel lymph node mapping in the evaluation of breast cancer

The initial reports of sentinel lymph node mapping for breast cancer currently appearing in the surgical literature are demonstrating the practicality and accuracy of the technique to evaluate patients for axillary nodal disease. We reviewed our initial 100 patient experience with sentinel node mapping to evaluate our ability to employ this technique in breast cancer patients. We combined a peritumoral injection of a radioactive substance and blue dye. Each sentinel node was evaluated with frozen section analysis, hematoxylin and eosin staining, and, if still negative, five re-cuts were taken from deeper levels of the node and evaluated for immunohistochemical evidence of cytokeratin staining. Sentinel node(s) were identified in all but two patients with 51% demonstrating metastasis. We have demonstrated the ability to accurately perform sentinel node mapping in the evaluation of our breast cancer patients. This exciting advance should become a standard part of breast cancer surgery.

Metal complexes of taurine. The first reported solution equilibrium studies for complex formation by taurine at physiological pH; the copper(II)-glycylglycinate-taurine and the copper(II)-glycylaspartate-taurine systems

The first solution studies at physiological pH for the formation of metal complexes of taurine, +NH3CH2CH2S03-, one of the most abundant low molecular weight organic compounds in the animal kingdom, are reported. The complexes Cu(Gly-GlyH-1) (1) and [Cu(Gly-AspH-1)] (2) react with taurine to give the ternary complexes [Cu(Gly-GlyH-1)taurine]- (3) (log K=2.95+/-0.03, I=0.2M, T=25.0 degrees C) and [Cu(Gly-AspH-1)taurine]2- (4) (log K=2.68+/-0.02) in which taurine acts as an N-donor ligand, most likely monodentate, without involvement of the sulphonate group in coordination. The results of the pH-metric studies are confirmed by visible and EPR spectrophotometric studies. The taurine complexes are less stable than the analogous complexes of beta-alanine due to the decreased basicity of the amino group in the former ligand, and in the case of the Cu(Gly-GlyH-1) complexes due to involvement of the carboxylate group of beta-alanine in axial coordination.

[The role of intraoperative gamma-probe-guided sentinel lymph node biopsy in the treatment of malignant melanoma and breast cancer]

In the treatment of malignant tumors regional lymphadenectomy is used for two purposes. It is used partly for staging the regional lymph nodes which is a significant and independent prognostic factor and determines the need for adjuvant oncologic treatment and partly for achieving locoregional disease control. Removal of tumor-free lymph nodes by regional lymph node clearance is unnecessary according to our current knowledge. Since the sensitivity and specificity of non-invasive clinical examinations are insufficient in predicting the nodal status the histological study of the regional lymph nodes cannot be abandoned. A new and minimally invasive surgical procedure, the mapping and removal of the first tumor draining lymph node, the sentinel node provides the possibility of pathological nodal staging without performing formal lymphadenectomy. Mapping of the sentinel node can be performed by the use of a radioisotope and intraoperative hand-held gamma-probe or a vital blue dye or a combination of these two. This latter method was used by the authors in 73 patients (25 with malignant melanoma and 48 with breast cancer). Sentinel lymph node biopsy was performed successfully in 92% of patients with melanoma and 90% of patients with breast cancer. In three breast cancer patients the sentinel node inaccurately predicted the axillary status as negative, but is was in 93% accurate in predicting the histologic nodal state. According to our preliminary experiences intraoperative gamma-probe guided sentinel lymph node biopsy is considered a feasible procedure in both malignant melanoma and breast cancer. More experiences are needed before introducing this method in the routine clinical practice.

The research of lichenized fungi in Hungary

A brief historical account on the Hungarian lichenology is given in three stages. The early stage involves the oldest collections and the lichenological activity of F. Hazslinszky. In the mid-stage a separate, independent lichen collection was established in the Natural History Museum, and a rapid development of floristical and taxonomic research took place. Recent lichenological research in Hungary follows several fields: taxonomy, biogeography, bioindication and ecophysiology.

[Complications in laparoscopic cholecystectomy]

INTRODUCTION

For more than a century classical cholecystectomy has been a method of choice in surgical management of gallbladder diseases. At the end of eighties and at the beginning of nineties of this century, laparoscopic cholecystectomy has been introduced gradually taking the place of classical. Numerous studies deal with complications associated with this surgical procedure.

COMPLICATIONS RELATED TO INSERTION OF VERESS NEEDLE

During insertion of Veress needle, injuries of the frontal abdominal wall may occur (9). Insertion of the needle into the peritoneal cavity may cause: injury of the omentum with consequential hemorrhage; intestinal and mesenteric injuries as well as injuries of urinary bladder and great blood vessels of retroperitoneum. Initial insufflation of CO2 through the needle, if it is inadequately placed, may cause subacute emphysema, intraperitoneal adhesion formation, mediastinal emphysema and pneumothorax (8-10). COMPLICATIONS RELATED TO TROCAR INSERTION--TROCAR INJURIES: Apart from injuries associated with insertion of Veress needle, insertion of trocar may cause injuries of the liver, spleen and falciform ligament (4). Trocar injuries are more severe (8,9).

BILE DUCTS INJURIES

Bile ducts injuries are divided into mild (injuries of a smaller bile duct, incomplete ductus cysticus occlusion or partial that is lateral injury of greater ducts) and severe (injuries of duct choledochus or hepatic ducts) (1). Bile ducts injuries are extremely severe complications with high morbidity, long-term hospitalization and may be life threatening (11,12).

INTRAOPERATIVE BLEEDING

Intensive and uncontrolled intraoperative bleeding, especially within the operative field, both arterial (from arterial cyst) and venous (gallbladder, vena porte) requires conversion. POSTOPERATIVE HEMORRHAGE: Postoperative hemorrhage usually occurs in cases of cystic artery damage, prolonged hemorrhage from the gallbladder, parenchymal liver injuries and as well as in open cholecystectomy it is an indication for reoperation (8,9).

OTHER COMPLICATIONS

Other complications, thermic and mechanic diaphragmatic injuries and infections of incisional injuries and herniations at the place of trocar insertion.

OUR EXPERIENCES

In the period June 1995-November 1997, 500 patients underwent laparoscopic cholecystectomy (401 female--80.2% and 99 male--19.8%) aging from 16-78 years of age, average age 46 years. 16 (3.2%) mild complications were recorded (reoperation was necessary in one case): 1) subcutaneous emphysema in 3 patients (0.6%) which gradually disappeared up to 36 hours after surgery; 2) Retzin's space emphysema in 1 patient (0.2%) causing dysuria for 3 days; 3) bilirea--bile excretion through subhepatic drain in 2 patients (0.4%)--from the second to seventh postoperative day (excretion did not exceed 500 ml a day) and it spontaneously stopped; 4) inflammatory hematoma of the falciform ligament (0.02%); 5) in 8 patients (1.6%) postoperative infection of infraxifoid wound was registered; 6) in 1 patient (0.2%) segmental bile duct injury occurred. Out of 500 laparoscopic cholecystectomies conversion was necessary in 19 cases (3.8%).

CONCLUSION

In spite of numerous advantages and better comfort for patients, this method may have complications, whereas incidence of bile ducts injuries seems to be higher than in the classical procedure. The more laparoscopic cholecystectomies are performed, the more bile ducts injuries occur. Out of 500 laparoscopic cholecystectomies performed at the Surgery Department of the hospital in Senta, 3.2% of mild complications were registered with 1 case needing reoperation, while in 1 case (0.2%) it was probably type A bile duct injury.