Long-term delivery of all-trans-retinoic acid using biodegradable PLLA/PEG-PLLA blended microspheres

All-trans-retinoic acid (atRA) has been proved to be effective against several malignancies in human clinical trials. However, in many patients who were treated with atRA, the cancer relapsed after a brief remission. One reason for such relapse is that atRA is metabolized by specific P450s that are induced in the liver during prolonged atRA treatments. In order to overcome such a drawback of atRA, we prepared biodegradable microspheres to provide continuous release of atRA for a long period of time. These biodegradable microspheres were prepared by poly(L-lactide) (PLLA) and polyethylene glycol (PEG)-PLLA diblock copolymers (PLE) in various blending ratios to control the release rate of atRA. As the PLE content in microsphere was increased, the density of the hydrophilic PEG block of PLE on microsphere surfaces increased and the microspheres were dispersed well in PBS without any surfactants. Various release patterns of atRA were obtained according to PLE and atRA contents in the microspheres. Especially, the pseudo-zero-order release profiles were observed for 5 weeks when the contents of PLE and atRA in the microspheres were above 4 wt.%.

Baryon rapidity loss in relativistic Au + Au collisions

An excitation function of proton rapidity distributions for different centralities is reported from AGS Experiment E917 for Au+Au collisions at 6, 8, and 10.8 GeV/nucleon. The rapidity distributions from peripheral collisions have a valley at midrapidity which smoothly change to distributions that display a broad peak at midrapidity for central collisions. The mean rapidity loss increases with increasing beam energy, whereas the fraction of protons consistent with isotropic emission from a stationary source at midrapidity decreases with increasing beam energy. The data suggest that the stopping is substantially less than complete at these energies.

Seronegative spondyloarthropathy initiated by physical trauma

We undertook this study to demonstrate the pattern of onset and the course of arthritis on the traumatised joint in spondyloarthropathy (SpA) initiated by physical trauma. Among 288 patients with SpA, 12 (4.2%) whose arthropathies were associated with trauma were reviewed retrospectively. There were seven patients with ankylosing spondylitis (AS), three with juvenile onset AS and two undifferentiated SpA. The type of trauma was direct injury to the joint and injuries at other sites, except in spinal surgery, for example. In eight cases the initial evidence of disease was peripheral arthritis. The disease first occurred in traumatised joints in five cases. Only three cases showed recurrent inflammatory episodes in the traumatised joints throughout the disease course. SpA initiated by trauma initially manifested as peripheral arthritis at the traumatised joints in about half of the cases. Inflammatory episodes preferentially involved other joints apart from the traumatised joints throughout the whole course of the disease.

Mixed connective tissue disease associated with skin defects of livedoid vasculitis

A 21-year-old woman who had a 2-year history of mixed connective tissue disease (MCTD) developed rapidly evolving ulcers consistent with livedoid vasculitis (LV) in all distal extremities. She presented clinically with Raynaud's phenomenon, polyarthritis and swollen hands; serologically with high titres of ANA and anti-nRNP; and immunogenetically with HLA-DR4 and HLA-DR53. Although there was initial success in treatment except for the skin defects over the ankles, the patient died from disseminated intravascular coagulation. We suggest that LV may be a poor prognostic manifestation in MCTD.

5-acyloxy-5-hydroxymethyltetrahydro-2-furancarboxylate as a novel template for protein kinase C (PKC) binding

A series of alkyl tetrahydrofuran-2-carboxylates (1-4) bearing a new set of three pharmacophoric groups were tested as protein kinase C (PKC) ligands. The compounds were synthesized from commercially available glycidyl 4-methoxyphenyl ether. The correlation between their binding affinities for PKC-alpha and a conformational fit to phorbol ester indicates they mimic a pharmacophore model comprising the C20-OH, C3-C=O and C9-OH rather than that including the C13-C=O moiety.

Transverse myelitis in a patient with long-standing ankylosing spondylitis

Ankylosing spondylitis is reported to involve not only the joints but other organs as well. Among these extra-articular involvements, uncommon complications associated with nervous system such as single root lesions, compression of the myelum and cauda equina syndrome have also been documented. Here we present a patient with long-standing ankylosing spondylitis who developed spastic paraparesis. Extensive study to find the cause of a spastic paraparesis failed and therefore led to the conclusion that this patient was suffering from transverse myelitis. Similar reports in the past have been attributed to an association with multiple sclerosis; however, we suggest that the findings support the diagnosis of a rare complication of ankylosing spondylitis with an unknown etiology.

Parapharyngeal second branchial cyst manifesting as cranial nerve palsies: MR findings

SUMMARY

We report the MR findings of parapharyngeal branchial cleft cyst manifesting as multiple, lower cranial nerve palsies in a 35-year-old woman. On MR images, a well-marginated cystic mass was detected in the right parapharyngeal space, with displacement of both the right internal carotid artery and the right internal jugular vein on the posterolateral side. The cyst contained a whitish fluid that was slightly hyperintense on T1-weighted images and slightly hypointense to CSF on T2-weighted images. No enhancement on contrast-enhanced T1-weighted images was present. The right side of the tongue showed high signal intensity on T2-weighted images, suggesting denervation.

Bicritical scaling behavior in unidirectionally coupled oscillators

We study the scaling behavior of period doublings in a system of two unidirectionally coupled parametrically forced pendulums near a bicritical point where two critical lines of period-doubling transition to chaos in both subsystems meet. When crossing a bicritical point, a hyperchaotic attractor with two positive Lyapunov exponents appears, i.e., a transition to hyperchaos occurs. Varying the control parameters of the two subsystems, the unidirectionally coupled parametrically forced pendulums exhibit multiple period-doubling transitions to hyperchaos. For each transition to hyperchaos, using both a "residue-matching" renormalization group method and a direct numerical method, we make an analysis of the bicritical scaling behavior. It is thus found that the second response subsystem exhibits a new type of non-Feigenbaum scaling behavior, while the first drive subsystem is in the usual Feigenbaum critical state. The universality of the bicriticality is also examined for several different types of unidirectional couplings.

Expression of Fas and Fas-related molecules in human hepatocellular carcinoma

Many tumor cells, including hepatocellular carcinoma (HCC), express both Fas and its ligand on their surfaces, and it has remained a mystery why such cells do not spontaneously become apoptotic. In the current study, we analyzed the alterations of Fas structure and the expression of Fas and Fas ligand (FasL) and of Fas pathway inhibitors, including soluble Fas (sFas), Fas-associated phosphatase-1 (FAP-1), and bcl-2, in 50 cases of human HCC. Monoallelic loss of the Fas gene, as determined by loss of heterozygosity with intragenic polymorphisms, was observed in 5 of the 34 informative cases (15%), but none of the 50 cases showed Fas gene mutation. Expression of Fas and FasL was detected in 44 (88%) and 50 (100%) cases, respectively. sFas messenger RNA, as analyzed by in situ reverse-transcription polymerase chain reaction was expressed in 42 of the 50 cases (84%), and FAP-1 expression was observed in 40 of the 50 cases (80%). In contrast, none of the 50 cases showed bcl-2 expression. Our results showed that the majority of the HCCs (88%) coexpressed a death receptor, Fas and its cognate ligand, FasL, but all HCCs showed one or more alterations of the Fas pathway molecules known to inhibit Fas-mediated apoptosis. These findings suggest that the expression of sFas and FAP-1 and, in part, loss of Fas expression, rather than Fas gene alteration or bcl-2 expression, may be involved in the Fas resistance of HCC in vivo and that these mechanisms may play important roles in the pathogenesis of human HCC. HUM PATHOL 32:250-256.

Dissociation between plasma adrenocorticotropin and serum cortisol level during the early postoperative period after gastrectomy

We demonstrated the dissociation between plasma adrenocorticotropin (ACTH) and serum cortisol levels during the early recovery period after radical gastrectomy in 9 of 31 patients with gastric adenocarcinoma. Patients with the dissociation between plasma ACTH and serum cortisol levels (DAC) showed a sustained elevation of serum cortisol level on the first or second postoperative day, while the plasma ACTH level returned to its preoperative state. These patients also had more advanced cancers (p < 0.05) and suffered from more postoperative complications (p < 0.05) than those without DAC. In these patients with DAC, serum cortisol and interleukin (IL)-6 levels remained higher on the second postoperative day than in those of the patients without DAC (21.80 +/- 1.57 vs. 13.68 +/- 0.72 microg/dl, p < 0.001, and 74.31 +/- 15.65 vs. 18.75 +/- 3.14 pg/ml, p < 0.001, respectively). On the second postoperative day, serum IL-6 levels showed a significant correlation with serum cortisol levels in all patients (r = 0.511, p < 0.01). These results suggest that the DAC during the early postoperative period after radical gastrectomy is associated with advanced stage of cancer and postoperative complication, and that the increased serum IL-6 level is at least in part responsible for maintaining the elevated serum cortisol.

NO as an autocrine mediator in the apoptosis of activated microglial cells: correlation between activation and apoptosis of microglial cells

Abnormal activation of microglial cells has been implicated in various neurodegenerative diseases. Microglial activation needs to be tightly regulated for physiological maintenance and normal functioning of the central nervous system. Potential mechanisms for the down-regulation of activated microglial cells are the deactivation or elimination of activated cells. We hypothesized that the elimination of activated microglial cells by apoptosis is one of the key mechanisms of auto-regulation of activated microglial cells. To test this hypothesis, we utilized BV-2 mouse microglial cells and rat primary microglial cultures exposed to activating agents such as lipopolysaccharide and interferon-gamma, and investigated a possible correlation between apoptosis and activation of these cells. We found that the activation of microglial cells led to apoptotic death, and the activation state of microglial cells inversely correlated with cell viability. We have also demonstrated that: (i) NO was produced by activated microglial cells in a manner dependent on time and dose of activating agents; (ii) inhibition of NO synthesis by iNOS inhibitor blocked the apoptosis of activated microglial cells; (iii) an exogenous NO donor induced apoptosis of microglial cells; and (iv) inhibition of TNFalpha or FasL using neutralizing antibodies did not affect activation-induced apoptosis of microglial cells. These results indicated that activation of microglial cells leads to the production of NO, which in turn acts as the major mediator of cellular apoptosis in an autocrine fashion. Our work suggests the presence of auto-regulatory mechanism for microglial activation, which may have relevance in the pathogenesis of various neurodegenerative diseases possibly resulting from 'over-activation' of microglial cells.

Association of alpha-2-macroglobulin deletion polymorphism with sporadic Alzheimer's disease in Koreans

Alpha-2-macroglobulin (A2M) deletion polymorphism was recently reported to be associated with Alzheimer's disease (AD) in a way comparable to apolipoprotein E (APOE) polymorphism in a family-based study. However, the association of A2M deletion polymorphism with AD has not been consistently replicated in successive case-controlled studies. In order to evaluate whether this A2M polymorphism is associated with AD in Koreans, we examined the frequencies of the A2M deletion (D) allele and D-bearing genotypes in a group of Koreans composed of 100 sporadic AD patients and 203 control subjects. The frequency of the deletion (D) allele (P=0.046) was significantly different between the total group of AD patients and the controls, although the frequency of the D-bearing genotypes did not attain significance (P=0.078). When the subjects were stratified according to age at onset, there was significant difference in the frequencies of the D allele (P=0.044) and D-bearing genotypes (P=0.041) between late-onset AD patients (> or =65 years) and the controls. However, no significant difference was observed between early-onset AD patients (<65 years) and the control group. Additionally, when we divided the late-onset AD and control subjects by APOE epsilon4 status, the difference of the A2M D allelic frequency was significant only in the APOE epsilon4 negative subjects (P=0.015). In conclusion, our data suggests that the A2M D allele is a modest risk factor for late-onset sporadic AD in Koreans, and the AD risk conferred by the A2M D allele increases in APOE epsilon4 negative subjects.

Prevalence of Gs alpha mutations in Korean patients with pituitary adenomas

The reported frequencies of Gs alpha mutations (gsp mutations) in growth hormone (GH)-secreting pituitary adenomas are variable (ranging from 4.4 to 43%), and the presence of these mutations in the other pituitary adenomas is still a matter of controversy. Previous clinical and biochemical analyses of patients with GH-secreting pituitary adenomas and gsp mutations produced conflicting results and did not demonstrate obvious characteristics. Therefore, we investigated the prevalence of gsp mutations in Korean patients with pituitary adenomas and elucidated the characteristics of these patients. Forty-four GH-secreting adenomas, 7 prolactin (PRL)-secreting adenomas and 32 clinically non-functioning adenomas were examined for the presence of point mutations in codon 201 and 227 of the Gs alpha gene using a nested PCR and direct sequencing of DNA extracted from fresh tissue or paraffin-embedded pituitary adenoma samples. Seven of the 44 GH-secreting pituitary adenomas had point mutations at codon 201 or 227; of these, five mutations were in codon 201 and two were in codon 227. In patients with gsp mutations, mean tumor size was significantly smaller than in patients without gsp mutations (15.9+/-8.7 mm vs. 24.9+/-14.9 mm, P<0.05). Age, sex, basal GH levels, GH response to oral glucose loading, GH response to octreotide and surgical outcome were not different in the two groups. One of the 32 clinically non-functioning pituitary adenomas had a point mutation at codon 201; none of the seven prolactinomas had these mutations. These results show that gsp mutations are not rare in Korean acromegalic patients and mean tumor size is significantly smaller in acromegalic patients with gsp mutations. Our results also confirm the low frequency of gsp mutations in clinically non-functioning pituitary adenomas and the absence of gsp mutations in prolactinoma.

Somatic mutations in the death domain of the Fas (Apo-1/CD95) gene in gastric cancer

It is now believed that genes regulating apoptosis are also important variables in cancer development. Fas, a transmembrane protein of the tumour necrosis factor receptor family, is a key molecule for cell death signalling. The mutation of the primary structure of the Fas gene might also be one of the possible mechanisms that disrupt Fas-mediated apoptosis in tumour cells. The purpose of this study was to determine whether somatic mutation of the Fas gene could be involved in the tumourigenesis of gastric cancer. Polymerase chain reaction (PCR)-based loss of heterozygosity (LOH) analysis with two intragenic polymorphic markers, and mutation analysis for the entire coding regions of the Fas gene were performed in 43 cases of gastric cancer, using PCR-single-strand conformational polymorphism sequencing. Five (11.6%) missense mutations were detected, only in the death domain of the Fas gene. Although these mutations were observed only in intestinal-type gastric cancers, there was no statistically significant difference in the frequency of Fas mutation between intestinal- and diffuse-type gastric cancer (p=0.068). Nine LOH out of 22 informative cases were also detected with one or both markers (41%). Three of them demonstrated a somatic mutation in the remaining allele, indicating the inactivation of both alleles. These results suggest that genetic alterations of the Fas gene may not only be limited to gastric cancer cell protection through Fas resistance, but may also play an important role in tumour promotion and/or progression in a subset of gastric cancer.

Mechanism for the riddling transition in coupled chaotic systems

We investigate the loss of chaos synchronization in coupled chaotic systems without symmetry from the point of view of bifurcations of unstable periodic orbits embedded in the synchronous chaotic attractor (SCA). A mechanism for direct transition to global riddling through a transcritical contact bifurcation between a periodic saddle embedded in the SCA and a repeller on the boundary of its basin of attraction is thus found. Note that this bifurcation mechanism is different from that in coupled chaotic systems with symmetry. After such a riddling transition, the basin becomes globally riddled with a dense set of repelling tongues leading to divergent orbits. This riddled basin is also characterized by divergence and uncertainty exponents, and thus typical power-law scaling is found.

Somatic mutations of TRAIL-receptor 1 and TRAIL-receptor 2 genes in non-Hodgkin's lymphoma

Tumor necrosis factor-related apoptosis-inducing ligand-receptor 1 (TRAIL-R1) and tumor necrosis factor-related apoptosis-inducing ligand-receptor 2 (TRAIL-R2) are cell-surface receptors involved in tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)-induced cell-death signaling. TRAIL-R1 and TRAIL-R2 genes have recently been mapped to chromosome 8p21-22, which is a frequent site of allelic deletions in many types of human tumors, including non-Hodgkin's lymphoma (NHL). Because TRAIL/TRAIL receptor system plays an important role in lymphocyte homeostasis, we hypothesized that the mutations of TRAIL-R1 and TRAIL-R2 may be involved in the development of NHL and that such mutations may be responsible for the allelic losses of 8p21-22 in NHL. In this study, we analysed the entire coding region of TRAIL-R2 gene and the death domain region of TRAIL-R1 gene for the detection of the somatic mutations in a series of 117 human NHLs using polymerase chain reaction (PCR)-based single strand conformation polymorphism (SSCP) analysis. Overall, eight tumors (6.8%) were found to have two TRAIL-R1 gene mutations or six TRAIL-R2 gene mutations. Interestingly, of the eight mutations, six missense mutations (two TRAIL-R1 and four TRAIL-R2) were detected in the death domains and one nonsense mutation of TRAIL-R2 was detected just before the death domain. Our data suggest that somatic mutations of TRAIL-R1 and TRAIL-R2 genes may play a role in the pathogenesis of some NHLs and that TRAIL-R1 and TRAIL-R2 genes might be the relevant genes to the frequent loss of chromosome 8p21-22 in human NHL.

The impact of biomass harvesting on phosphorus uptake by wetland plants

Two species of macrophytes, Baumea articulata and Schoenoplectus mucronatus, were examined for their capacity to remove phosphorus under nutrient-rich conditions. Forty large bucket systems with the two different species growing in two types of substrate received artificial wastewaters for nine months, simulating a constructed wetland (CW) under high loading conditions. Half of the plants growing in the topsoil and gravel substrates were periodically harvested whereas the other half remained intact. Plant tissue and substrate samples were regularly analysed to determine their phosphorus concentrations. With respect to phosphorus uptake and removal, the Schoenoplectus in the topsoil medium performed better than the Baumea. Biomass harvesting enhanced P uptake in the Schoenoplectus, however the effect was not significant enough to make an improvement on the overall P removal, due to the slow recovery of plants and regrowth of biomass after harvesting. From P partitioning, it was found that the topsoil medium was the major P pool, storing most of total P present in the system. Plant parts contributed only minor storage with approximately half of that P stored below ground in the plant roots. The overall net effect of harvesting plant biomass was to only remove less than 5% of total phosphorus present in the system.

Nonlinear dynamic analysis of the EEG in patients with Alzheimer's disease and vascular dementia

To assess nonlinear EEG activity in patients with Alzheimer's disease (AD) and vascular dementia (VaD), the authors estimated the correlation dimension (D2) and the first positive Lyapunov exponent (L1) of the EEGs in both patients and age-matched healthy control subjects. EEGs were recorded in 15 electrodes from 12 AD patients, 12 VaD patients, and 14 healthy subjects. The AD patients had significantly lower D2 values than the normal control subjects, (P < H > 0.05), except at the F7 and the O1 electrodes, and the VaD patients, except at the C3 and the C4 electrodes. The VaD patients had relatively increased values of D2 and L1 compared with the AD patients, and rather higher values of D2 than the normal control subjects at the F7, F4, F8, Fp2, O1, and O2 electrodes. The L1 values of the EEGs were also lower for the AD patients than for the normal control subjects, except in the O1 and the O2 channels, and for the VaD patients at all electrodes. The L1 values were higher for the VaD patients than for the normal control subjects (F3, F4, F8, O1, and O2). In addition, the authors detected that the VaD patients had an uneven distribution of D2 values over the regions than the AD patients and the normal control subjects, although the statistics do not confirm this. By contrast, AD patients had uniformly lower D2 values in most regions, indicating that AD patients have less complex temporal characteristics of the EEG in entire regions. These nonlinear analyses of the EEG may be helpful in understanding the nonlinear EEG activity in AD and VaD.

N-(3-Acyloxy-2-benzylpropyl)-N'-(4-hydroxy-3-methoxybenzyl) thiourea derivatives as potent vanilloid receptor agonists and analgesics

A series of N-(3-acyloxy-2-benzylpropyl)-N'-(4-hydroxy-3-methoxybenzyl) thiourea derivatives were investigated as vanilloid receptor ligands in an effort to discover a novel class of analgesics. The proposed pharmacophore model of resiniferatoxin. which includes the C20 homovanillic moiety, the C3-carbonyl and the orthoester phenyl ring as key pharmacophoric groups, was utilized as a guide for drug design. The compounds were synthesized after several steps from diethylmalonate and evaluated in vitro in a receptor binding assay and in a capsaicin-activated channel assay. Additional evaluation of analgesic activity, anti-inflammatory activity and pungency was conducted in animal models by the writhing test, the ear edema assay, and the eye-wiping test, respectively. Among the new compounds, 23 and 28 were found to be the most potent receptor agonists of the series with Ki values of 19 nM and 11 nM, respectively. Their strong in vitro potencies were also reflected by an excellent analgesic profile in animal tests with ED50 values of 0.5 microg kg for 23 and 1.0 microg/kg for 28. Relative to capsaicin these compounds appear to be ca. 600 and 300 times more potent. Both 23 and 28 were found to be less pungent than capsaicin based on the eye-wiping test. However, the compounds did not show significant anti-inflammatory activity. A molecular modeling study comparing the energy-minimized structures of resiniferatoxin and 35 demonstrated a good correlation in the spatial disposition of the corresponding key pharmacophores. The thioureas described in this investigation, which were designed as simplified resiniferatoxin surrogates, represent a novel class of potent vanilloid receptor agonists endowed with potent analgesic activity and reduced pungency.

Effect of heavy metals (Cu, Pb, and Ni) on the compositions of EPS in biofilms

A series of batch adsorption tests to estimate the biofilm capacity for removal of the heavy metals (Cu, Pb, and Ni) in wastewater were carried out. The metal sorption results were fitted to the Freundlich isotherm model to compare their sorption capacity. The change of the composition of EPSs (extracellular polymeric substances) was simultaneously represented by the ratio of carbohydrate to protein (C/P) when the biofilm was exposed to the heavy metals. EPS composed of slime loosely bound to the cell and capsular materials was extracted by the four general extraction methods including regular centrifugation, regular centrifugation with formaldehyde, EDTA extraction and steam extraction. Although the various extraction methods showed different results, C/P ratio of biofilm exposed to copper and lead metal ions was generally lower than that of control.

Varying expression levels of colony stimulating factor receptors in disease states and different leukocytes

Administration of G-CSF may not always respond in rise of neutrophil counts in different patient population. In order to understand a possible inter-relationship between the G-CSF and GM-CSF induced leukocyte responses and expression levels of receptors for G-CSF (G-CSFr) and GM-CSF (GM-CSFr), the levels of each receptor and CSF were measured in patients with basophilia (8), eosinophilia (14) and bacterial infection showing neutrophilia (12) in comparison with normal healthy adults (12) and children (14). G-CSFr was expressed in neutrophils in the largest amount followed by monocytes, but GM-CSFr was expressed more in monocytes than neutrophils. Lymphocytes and basophils did not express G-CSFr or GM-CSFr. The amount of GM-CSFr in neutrophils was present less in patients with infection than normal control (P = 0.031). The neutrophils expressed more G-CSFr than GM-CSFr. The quantity of G-CSFr in eosinophil showed marked interval change, higher in acute stage. The plasma concentrations of G-CSF in patients with infection were much higher than normal adults or children (117.95 +/- 181.16 pg/ml, P < 0.05). Binding assay with excess amount of CSFs could discriminate the patient who did not show any response to G-CSF or GM-CSF administration. After incubation with excess CSFs, more receptors were blocked in children than in adults (G-CSF P = 0.024, GM-CSF P = 0.006). These results indicate that the amount of CSFr in leukocyte varies in different types of leukocyte, and changes according to the patients' condition even in the same type of leukocyte, and the CSFrs of children bind to CSFs more than those of adults.

High glucose-induced intercellular adhesion molecule-1 (ICAM-1) expression through an osmotic effect in rat mesangial cells is PKC-NF-kappa B-dependent

AIMS/HYPOTHESIS

Infiltration of mononuclear cells and glomerular enlargement accompanied by glomerular cell proliferation are very early characteristics of the pathophysiology of diabetes. To clarify the mechanism of early diabetic nephropathy, we measured [3H]-thymidine incorporation and cell numbers to show the influence of a high ambient glucose concentration and the osmotic effect on rat mesangial cell proliferation. We also measured the effect of high glucose on the expression of intercellular adhesion molecule-1 and vascular adhesion molecule-1 by flow cytometry and semiquantitative RT-PCR in mesangial cells and the adhesion of leukocytes to mesangial cells.

METHODS/RESULTS

Cells exposed to high D-glucose (30 mmol/l) caused an increase in [3H]-thymidine incorporation and cell numbers at 24 and 48 h and normalized at 72 h (p < 0.05), whereas these changes were not found in high mannitol (30 mmol/l), IL-1 beta, or TNF alpha-stimulated mesangial cells. Cells exposed to high-glucose (15, 30, or 60 mmol/l) or osmotic agents (L-glucose, raffinose and mannitol) showed that intercellular adhesion molecule-1 expression began to increase after 24 h, reached its maximum at 24 and 48 h and gradually decreased afterwards. The stimulatory effects of high glucose and high mannitol on mRNA expression were observed as early as 6 h and reached its maximum at 12 h. Up-regulation of ICAM-1 protein and mRNA was also found in IL-1-beta and TNF-alpha-stimulated mesangial cells. Neither vascular adhesion molecule-1 protein nor mRNA expression was, however, affected by high glucose and high mannitol. Notably, the protein kinase C inhibitors calphostin C and staurosporine reduced high glucose- or high mannitol-induced intercellular adhesion molecule-1 mRNA expression and high glucose-induced proliferation. Furthermore, the NF-kappa B inhibitor N-tosyl-L-phenylalanine chloromethyl ketone reduced high glucose- or high mannitol-induced intercellular adhesion molecule-1 mRNA expression and high glucose-induced proliferation. Results showed that high glucose (15, 30 mmol/l) or high concentrations of osmotic agents remarkably increased the number of adherent leukocytes to mesangial cells (p < 0.01) compared with control cells (5 mmol/l D-glucose). Functional blocking of intercellular adhesion molecule-1 on mesangial cells with rat intercellular adhesion molecule-1 monoclonal antibody, calphostin C, staurosporine, or N-tosyl-L-phenylalanine chloromethyl ketone significantly inhibited high glucose- or high mannitol-induced increase in leukocyte adhesion (p << 0.05).

CONCLUSION/INTERPRETATION

These results suggest that high glucose can upregulate intercellular adhesion molecule-1 protein and mRNA expression but not vascular adhesion molecule-1 expression in mesangial cells and promote leukocyte adhesion through up-regulation of intercellular adhesion molecule-1 through osmotic effect, possibly depending on the protein kinase C nuclear factor-kappa B (PKC-NF-kappa B) pathway. High glucose itself can also promote mesangial cell proliferation through the PKC-NF-kappa B pathways. We conclude that hyperglycaemia in itself seems to be an important factor in the development of early diabetic nephropathy.

Two cases of orbital infarction syndrome

Orbital infarction syndrome is defined as ischemia of all intraorbital and intraocular structures. It is a rare disease caused by rich anastomotic vascularization of the orbit. It can occur secondary to different conditions, such as, acute perfusion failure, systemic vasculitis, orbital cellulitis and vasculitis. It results in orbital and ocular pain, total ophthalmoplegia, anterior and posterior segment ischemia, and acute blindness. We report here upon two cases of orbital infarction with similar presentations but with different causes, namely, mucormycosis and as a postoperative complication of intracranial aneurysm, discuss the possible mechanisms of orbital infarction, and present a review of the literature on the topic. The prompt recognition of clinical pictures and rapid diagnosis is essential for the early treatment of orbital infarction, since its progression is very rapid and it can be even fatal.

Effect of zinc on the visual sensitivity of the bullfrog's eye

There is a high concentration of zinc in ocular tissue, especially the retinachoroids, and the presence of physiological levels of zinc in these tissues seems essential for their normal function. The purpose of our study was to clarify this point using electroretinogram (ERG) recordings and spectrophotometer measurements before and after zinc treatment in a bullfrog's eye. The optimal zinc concentration used in this experiment was 1 microM ZnCl2, 100 microliters/6 ml ringer solution, with the result that the total zinc concentration in the ringer solution was 16.4 nM. To determine the effects of zinc on the retinal function, the changes of ERG parameters, such as threshold, a-, b- and c-waves and absorption spectra were observed before and after zinc treatment. It is noteworthy that high concentrations of zinc are present in the retina and the retinal pigment epithelium. Our results indicate that zinc treatment elevated the dark-adapted ERG threshold, all of the peak amplitudes of ERG were increased and rhodopsin regeneration was accelerated during visual adaptation. In spectral scans, absorbance increment due to zinc treatment was shown over the whole range of spectral scanning (300 nm-750 nm). We believe that zinc, which is abundant in the retina and the retinal pigment epithelium particularly, is an essential factor for the visual process and may be required to improve visual sensitivity during visual adaptation.