Ultrastructural localization of matrix metalloproteinase-9 in eosinophils from the cerebrospinal fluid of mice with eosinophilic meningitis caused by Angiostrongylus cantonensis

Matrix metalloproteinase-9 (MMP-9) has been implicated in the pathogenesis of eosinophilic meningitis caused by Angiostrongylus cantonensis. In the present study, such meningitis in mice was found to be associated with elevated expression of MMP-9 mRNA, elevated MMP-9 concentrations and enhanced MMP-9 activity in the cerebrospinal fluid (CSF). Immunocytochemistry showed that an anti-MMP-9 antibody reacted with macrophages, neutrophils and eosinophils from the CSF. As eosinophils are generally considered to be effector cells in host defence against A. cantonensis infection, high-resolution immuno-electron microscopy was then used to confirm the localization of MMP-9 in the eosinophils from the CSF. The method used, which was based on immunogold, indicated that the eosinophilic MMP-9 was mostly localized in the 'small' granules in the cytoplasm and along the cell membrane, and not in the crystalloid-containing secretory granules observed. It therefore appears that MMP-9 is synthesised and/or stored in the small granules of the eosinophils, and is released into the subarachnoid space of the host's brain by secretion or cell rupture.

Matrix metalloproteinase-2 and -9 in the granulomatous fibrosis of rats infected with Angiostrongylus cantonensis

The histomorphology of granuloma formation and gelatinase production were investigated in the brains, hearts, lungs and livers of Sprague-Dawley rats infected with Angiostrongylus cantonensis. The relationships between two gelatinases and granulomatous fibrosis were explored, following infection of each rat with 60 infective larvae of the nematode. Worm recovery from the brain was maximal on day 15 post-inoculation whereas peak recovery from the lungs was maximal 75 days later, on day 90. The granulomatous reactions and fibrosis were marked in the lungs but only mild, if present at all, in the brain, heart and liver. Gelatin zymography revealed that matrix metalloproteinase2 (MMP-2) was present, at all time-points, in the heart and lungs, although only in the lungs was there partial conversion of the 72-kDa pro-enzyme to the 64-kDa active form during granulomatous fibrosis. The activity of the MMP-9 pro-enzyme was significantly higher at the time-points when granuloma formation was observed than at other times. Immuno-histochemistry revealed MMP-2 and MMP-9 within the lung granulomas, around infiltrating leucocytes and the epithelial cells of the alveoli. As the granulomatous fibrosis appeared to be strongly associated with MMP-2 and MMP-9, these enzymes may be useful markers in the lungs of rats infected with A. cantonensis.

Induction of matrix metalloproteinase-9 in murine eosinophilic meningitis caused by Angiostrongylus cantonensis

Matrix metalloproteinases (MMP) have been implicated in the pathogenesis of various inflammatory diseases of the central nervous system. In the present study, a gelatinase was found to be induced in parasitic meningitis caused, in mice, by Angiostrongylus cantonensis. The enzyme had a molecular weight of about 94 kDa, showed maximal activity between pH 6 and pH 8, and was clearly inhibited by EDTA and 1,10-phenanthroline but not by leupeptin or phenylmethanesulphonyl fluoride. When samples of cerebrospinal fluid from the mice with meningitis were blotted with specific antiserum against gelatinase B (MMP-9), a 94-kDa immunopositive band was observed, indicating that the induced gelatinase was MMP-9. In the A. cantonensis-infected mice, immuno-histochemistry demonstrated MMP-9 within the endothelial cells lining the vascular spaces of the brain and in the leucocytes that were found, in aggregates, in the subarachnoid space. Leucocytes may play an important role in the pathogenesis of inflammatory disorders of the central nervous system.

Iodine nutritional status of adults during a period of salt iodization

BACKGROUND

To measure the iodine nutritional status of island adults in Zhoushan, China.

METHODS

A comparison study was carried out in eight villages. These were selected from iodized salt and non-iodized salt districts of Zhoushan island by random sampling. The Mann-Whitney test was used to compare the urinary iodine concentration and dietary iodine intake between the two districts.

RESULTS

The median of urinary iodine concentration in the non-iodized salt group was 90 micrograms/l, which was lower than 194 micrograms/l in the iodized salt group (u = 14.673; p < 0.000), whereas the median of daily dietary iodine intake in the two groups was 128 and 147 micrograms, respectively (u = 1.847; p = 0.065). There was no significant correlation between dietary iodine intake and urinary iodine concentration (p = 0.095).

CONCLUSIONS

Salt iodization is necessary. Special characteristics of the island diet should also be considered.

Oral retinoids for the prevention of skin cancers in solid organ transplant recipients: a systematic review of randomized controlled trials

BACKGROUND

The increased incidence of skin cancers after solid organ transplantation is well recognized. Skin cancers developing in transplant recipients are more aggressive in behaviour. Therapeutic options to reduce and/or delay the development of cutaneous neoplasms are therefore of interest.

OBJECTIVES

The objective of this review was to summarize the available medical literature from randomized controlled trials on the use of oral retinoids as a preventive agent for skin cancers in the solid organ transplant population.

METHODS

Three electronic databases were searched for relevant trials: MEDLINE (1966-October 2003), EMBASE (1980-week 44, 2003) and the Cochrane Controlled Trials Register (third quarter 2003). Randomized or quasi-randomized controlled clinical trials on subjects of any age or ethnic background who had received a solid organ transplant (cardiac, renal, liver, etc.) were evaluated. All titles and abstracts found by the search strategy were independently reviewed by two researchers for inclusion into the review.

RESULTS

Eighty-one abstracts were identified through the electronic databases for consideration. Review of the abstracts identified three eligible trials. One cross-over trial involving 23 subjects treated with acitretin 25 mg daily for 12 months reported 46 squamous cell carcinomas (SCCs) developing in six subjects during acitretin treatment vs. 65 SCCs developing in 15 subjects during the drug-free period. Another trial involving 44 subjects treated with acitretin 30 mg daily or placebo for 6 months reported two of 19 subjects developing two SCCs in the treatment group vs. nine of 19 subjects developing 18 new skin cancers (15 SCCs, one Bowen's disease, two basal cell carcinomas) in the placebo group. One dose comparison trial involving 26 renal transplant recipients treated with acitretin did not find a significant difference in numbers of skin cancers developing at the doses examined. The major limitation to the use of acitretin was poor tolerance due to adverse events. Headaches, rash, musculoskeletal symptoms and hyperlipidaemia were the most common causes of withdrawal from treatment. No alterations in renal or liver function were detected during the periods of treatment or follow-up.

CONCLUSIONS

The available data from a small number of randomized controlled trials suggest that acitretin may have a role in the management of solid organ transplant recipients with skin cancers. Tolerability of the drug is a major factor limiting its use. Appropriate selection of patients may help improve the risk-benefit ratio.

Efficacy of albendazole-GM6001 co-therapy against Angiostrongylus cantonensis-induced meningitis in BALB/c mice

Angiostrongylus cantonensis causes a form of parasitic meningitis in humans. Albendazole kills the nematode larvae staying in the brain. However, the dead larvae are capable of evoking a severe inflammatory response resulting in the brain damage. Matrix metalloproteinase 9 (MMP-9) is associated with the development of meningitis and with the immune inflammatory reaction. Presently, we studied the combination effects of albendazole and GM6001 (a MMP-9 inhibitor) against angiostrongyliasis in BALB/c mice. Co-administration of drugs produced marked effects; to kill the infecting larvae and to block MMP-9 activity. The combination treatment reduced MMP-9 activity by 89.2% in cerebrospinal fluid. The numbers of inflammatory cells increased significantly upon establishment of infection, but subsided upon co-treatment. Significantly fewer larvae were recovered from treated mice than from untreated, infected mice. The present results strongly suggest that co-therapy with albendazole and GM6001 may be an useful approach for the treatment of human angiostrongyliasis.

Induced eosinophilia and proliferation in Angiostrongylus cantonensis-infected mouse brain are associated with the induction of JAK/STAT1, IAP/NF-kappaB and MEKK1/JNK signals

Eosinophilic meningitis or meningoencephalitis caused by Angiostrongylus cantonensis is endemic to the Pacific area of Asia, especially Taiwan, Thailand, and Japan. Although eosinophilia is an important clinical manifestation of A. cantonensis infection, the role of eosinophils in the progress of the infection remains to be elucidated. In this experiment, we show that A. cantonensis-induced eosinophilia and inflammation might lead to the induction of IAP/NF-kappaB, JAK/STAT1 and MEKK1/JNK signals. The phosphorylation levels of JAK and JNK, STAT1, IAP, NF-kappaB and MEKK1 protein products were significantly increased after 12 days or 15 days of A. cantonensis infection. However, no significant differences in MAPKs such as Raf, MEK-1, ERK1/2 and p38 expression were found between control and infected mice. The activation potency of JAK/STAT1, IAP/NF-kappaB and MEKK1/JNK started increasing on day 3, with significant induction on day 12 or day 15 after A. cantonensis infection. Consistent results were noted in the pathological observations, including eosinophilia, leukocyte infiltration, granulomatous reactions, and time responses in the brain tissues of infected mice. These data suggest that the development of brain injury by eosinophilia of A. cantonensis infection is associated with activation of JAK/STAT1 signals by cytokines, and/or activation of MEKK1/JNK by oxidant stress, and/or activation of NF-kappaB by increasing IAP expression.

Induction of matrix metalloproteinase-9 in mice during Toxocara canis larvae migration

The relationships between inflammation in organs with Toxocara canis larval migration and matrix metalloproteinase-9 (MMP-9) were investigated following the infection of mice with 1,000 infective eggs. Gelatinase activity was defined by gelatin zymography, optimum pH, inhibitor specificity and Western blot analysis. MMP-9 activity was present in the lungs, liver, muscles, and brain during T. canis larval migration. This enzyme had a molecular weight of about 94 kDa and showed maximum activity in the pH range of 6-8. The increased MMP-9 proteinases coincided with larval recovery and the degree of inflammation among the four organs. These results suggest that MMP-9 may be associated with the inflammatory reaction to larval toxocariasis during early migration, and may therefore be a useful marker during T. canis larvae migration.

Regulation of MAO-A and MAO-B gene expression

MAO A and B genes are made of 15 exons with identical exon-intron organization. They are located on X-chromosome organized in opposite direction, tail to tail with 24 kb apart. Both promoters are GC-rich and regulated by transcription factor Sp1. However, they have distinctly different features. MAO B gene, but not MAO A gene, has TATA box. MAO B promoter contains two clusters of overlapping Sp1 sites, the CACCC repressor element. Transcription factors Sp1 and Sp4 can activate MAO B promoter activity through the proximal cluster of Sp1 sites and its activation can be repressed by the over-expression of Sp3 and a related family member, BTEB2. Decreased methylation and transcription repressor Sp3 upregulate human MAO B, but not MAO A, gene expression during Caco-2 differentiation. MAO B, but not MAO A gene, could be activated by PMA (phorbol 12-myristate 13-acetate) by protein kinase C, MAPkinase signal transduction pathway involves cJun and Egr-1. The differences in MAO A and B gene regulation may explain the different tissue-specific expression and functions of these two important isoenzymes.

The Nongenotropic Synthetic Ligand 4-Estren-3α17β-diol Is a High-Affinity Genotropic Androgen Receptor Agonist

The nongenotropic ligand estren (Science 298:843-846, 2002) was evaluated for its transcriptional activity mediated by the human androgen receptor (AR). Our results show that estren can bind, translocate, transactivate, and regulate two known target genes of AR in androgen-responsive cell lines. Estren binds recombinant AR with 10-fold higher affinity than either estrogen receptor (ER)-alpha or ERbeta. Estren-bound AR can translocate AR to the nucleus and stimulate the androgen response element-luciferase reporter activity with an efficacy similar to that of androgen. Estren also increased the expression of prostate-specific antigen (PSA) in a dose-dependent manner in human LnCaP cells. Using chromatin immunoprecipitation analysis, we show that the estren-bound AR coimmunoprecipitates with a region of the PSA gene promoter. Therefore, cotreatment with an AR antagonist, bicalutamide, blocked the estren-induced increase in PSA expression. In contrast, phosphoinositol 3-kinase inhibitor wortmannin, or extracellular signal-regulated kinase inhibitor 1,4-diamino-2,3-dicyano-1,4-bis(2-aminophynyltio)butadiene (U0126), and ER antagonist ICI-182780 failed to block the effects of estren. In vivo analysis of estren's action on male-orchidectomized ICR mice revealed estren's AR agonist actions on the levator ani and seminal vesicle target tissues. Taken together, our results reveal the hitherto unidentified genotropic action of estren mediated by AR in androgen-responsive cells and tissues.

Termite feeding deterrent from Japanese larch wood

Extraction of flavonoids from Japanese larch (Larix leptolepis) wood with water was carried out to prepare a termite feeding deterrent. A two-stage procedure for the extraction was adopted. The first extraction step was performed at ambient temperature (22 degrees C) and the second at elevated temperatures ranging 50-100 degrees C. The first step mainly gave a mixture of polysaccharides together with small amount of flavonoids. At the second step, the yield of extract and its chemical composition were greatly affected by the temperature. The yield of solubilised carbohydrates steadily increased with a rise in the temperature, while the overall yield of flavonoids reached its optimum at 70 degrees C. An additional increase in the temperature resulted in a decrease in the yield. Model experiments using dihydroflavonols confirmed the occurrence of oxidative dehydrogenation and/or intramolecular rearrangement during the hydrothermal treatment at higher temperatures. The crude water extracts showed strong feeding deterrent activities against the subterranean termite, Coptotermes formosanus, in a choice paper disc assay. The extracts containing flavonoids in large quantities exhibited potent termite feeding deterrent activities.

Association of matrix metalloproteinase-9 in eosinophilic meningitis of BALB/c mice caused by Angiostrongylus cantonensis

Induction of gelatinase in eosinophilic meningitis of BALB/c-strain mice was caused by Angiostrongylus cantonensis. Time-course studies showed that the molecular weight of 94-kDa gelatinase was detected at day 10 post-inoculation (PI), and reached a high intensity from days 15 to 25 PI. The 94-kDa gelatinase activity was clearly inhibited by EDTA and 1,10-phenanthroline, but not by leupeptin and phenylmethanesulphonyl fluoride. When immunoblots were performed using specific antiserums against the 94-kDa gelatinase B (matrix metalloproteinase-9; MMP-9) with cerebrospinal fluid (CSF), the 94-kDa immunopositive band was MMP-9. Immunohistochemistry studies demonstrated MMP-9 localisation within eosinophils and macrophages. The increased MMP-9 activity was closely associated with the rapid rise of CSF eosinophils, and the inflammatory reaction of the subarachnoid space. In contrast to changes in MMP-9, MMP-2 activity was constitutive and unaffected in this parasitic meningitis. These results show that MMP-9 was associated with eosinophilic meningitis, and that the enzyme may be a useful marker for angiostrongyliasis meningitis.

MAO-B knockout mice exhibit deficient habituation of locomotor activity but normal nicotine intake

Low levels of monoamine oxidase-B (MAO-B) activity, such as those observed in smokers, are also associated with behavioral traits such as a heightened responsiveness to novelty. However, the exact mechanism by which low MAO-B activity influences smoking and heightened responsiveness to novelty is still poorly understood. We used MAO-B knockout (KO) mice to test the hypothesis that MAO-B concomitantly affects locomotor responses in a novel inescapable open field and nicotine intake. Male wild-type (WT) and MAO-B KO mice were placed in an inescapable open field and their horizontal locomotor activity was measured for 30 min per day for 5 days. MAO-B KO mice exhibited impaired within-session habituation of locomotor activity, as compared to WT mice. Separate groups of male WT and MAO-B KO mice were individually housed in their home cages with two water bottles. One of the bottles contained tap water and the other contained nicotine (0, 3.125, 6.25, 12.5, 25, 50 or 100 micro g/ml). The total amount of water and nicotine solution consumed was measured every three days for 16 days. MAO-B KO mice and WT mice consumed equal amounts of nicotine and exhibited comparable concentration-dependent nicotine preference and aversion over a period of 16 days. The data suggest that the absence of MAO-B impairs the ability of mice to habituate in the inescapable environment, but does not alter their nicotine intake.

Cloning and characterization of the mouse Arht2 gene which encodes a putative atypical GTPase

ARHT is a new subgroup of the Rho family identified recently, which consists of two Rho-like genes, Arht1 and Arht2. ARHT may be involved in mitochondrial homeostasis and apoptosis. Constitutively active mutants of ARHT1 induced an aggregation of the mitochondrial network and resulted in an increased apoptotic rate of the cells. Here we report the molecular cloning and characterization of a novel mouse cDNA encoding a putative atypical GTPase protein, Arht2. Mouse Arht2 consists of 19 exons and has been mapped to mouse chromosome 17A3.3. Both human and mouse Arht2 genes are ubiquitously expressed in adult tissues. The results of RT-PCR experiments indicated that the Arht2 gene is expressed in all stages of mouse testis and reached the adult level of transcription at postnatal day 30. In situ hybridization revealed strong hybridization signals of Arht2 in residual bodies. In the mouse testis, Arht2 may be involved in the differentiation of testis and spermiogenesis. The molecular characterization of the mouse Arht2 gene may provide a clue for functional studies of the human ARHT genes.

Improving the diffuse optical imaging spatial resolution of the cerebral hemodynamic response to brain activation in humans

We compare two geometries of sources and detectors for optimizing the diffuse optical imaging resolution of brain activation in humans. Because of limitations in the instruments' dynamic range, most diffuse optical brain activation images have used only nonoverlapping measurements. We demonstrate theoretically and with a human experiment that a simple geometry of sources and detectors can provide overlapping measurements within the limitation of instrumentation dynamic range and produce an image resolution and localization accuracy that is twofold better.

The efficacy of therapy with albendazole in mice with parasitic meningitis caused by Angiostrongylus cantonensis

Matrix metalloproteinase 9 (MMP-9) is involved in the pathogenesis of parasitic meningitis caused by the nematode Angiostrongylus cantonensis. The present study evaluated the efficacy of albendazole therapy in BALB/c mice infected with the third stage larvae of this nematode. Albendazole showed a pronounced larvicidal activity. Eosinophil numbers significantly increased in infected mice but decreased upon administration of albendazole. Densitometric scanning indicated that albendazole reduced gelatinolytic activity detected by gelatin-substrate zymography. In the cerebrospinal fluid, albendazole reduced the lytic area intensity of the 94 kDa MMP-9 band by 46.5% within 7 days, and by 51.5% by day 14. Examination of brain tissue revealed a similar pattern of decrease (48.6% by day 7, and 53.9% by day 14). Albendazole may thus be an effective compound for the treatment of angiostrongyliasis through its larvicidal activity and facilitation of an improved inflammatory response via the reduction of MMP-9 activity.

The serum of rats administered flavonoid extract from Epimedium sagittatum but not the extract itself enhances the development of rat calvarial osteoblast-like cells in vitro

The flavonoid extract from Epimedium sagittatum (FES) has been found by us to be effective in preventing osteoporosis induced by ovariectomy in rats. In the present study, the effect of FES on the development of rat calvarial osteoblast-like (ROB) cells was investigated. No appreciable effect was observed when ROB cells were exposed to FES in vitro. However, serum isolated from rats administered FES orally was able to significantly stimulate the proliferation as well as the osteoblastic differentiation of ROB cells compared to serum from control rats. The results indicate that the serum of rats administered FES contains active metabolites ofFES that enhance the development of osteoblasts, while the original form of FES itself is inactive.

Persistence of abnormal neural responses to a meal in postobese individuals

OBJECTIVE

To determine whether abnormal obese-like neural responses to a meal persist in postobese individuals, who achieved and maintained a normal body weight despite a past history of severe obesity.

DESIGN AND SUBJECTS

Cross-sectional study of the brain's response to tasting and consuming a satiating meal in 11 postobese (age: 40+/-6 y, body mass index (BMI): 23.6+/-1.9 kg/m(2)), 23 obese (age: 29+/-6 y, BMI: 39.6+/-3.8 kg/m(2)) and 21 lean (age: 33+/-9 y, BMI: 22.8+/-2.1 kg/m(2)) subjects.

MEASUREMENTS

Regional cerebral blood flow (rCBF, a marker of neural activity) at baseline (after a 36-h fast), after tasting and after consuming a satiating liquid meal was assessed using positron emission tomography and state-dependent changes (taste-baseline; satiation-baseline), and compared across groups. Subjective ratings of hunger and fullness were measured by a visual analogue scale and body fatness by dual-energy X-ray absorptiometry.

RESULTS

In response to tasting the liquid meal, changes in rCBF were different in the obese as compared to the lean individuals (P<0.05, corrected for multiple comparisons) in the middle insula (peak voxel, x=-41, y=1, z=8; Montreal Neurological Institute coordinates) and posterior cingulate cortex (peak voxel, x=17, y=-47, z=40). The middle insular cortex exhibited a similar increase of neural activity in the obese and postobese subjects, whereas in the lean subjects the regional activity did not change. In the posterior cingulate cortex, the changes in rCBF in the postobese subjects were not different from those in the other groups. In response to a satiating amount of the same liquid meal, changes in rCBF were different in the obese as compared to the lean individuals (P<0.05, corrected for multiple comparisons) in the posterior hippocampus (peak voxel, x=21, y=-45, x=4), posterior cingulate cortex (peak voxel, x=17, y=-47, z=40), and amygdala (peak voxel, x=27, y=1, z=-24). The posterior hippocampus exhibited a similar decrease of neural activity in the obese and postobese subjects, whereas in the lean subjects the regional activity increased. In the posterior cingulate cortex and amygdala, the changes in rCBF were not different between the postobese and lean individuals. None of the changes in neural activity were correlated with the age of the individuals, the subjective ratings of hunger and fullness, or the meal induced-changes in plasma glucose, insulin, or serum free fatty acids.

CONCLUSION

Persistence of abnormal neural responses to a meal in the postobese individuals, a group at high risk for relapse, indicates that a predisposition to obesity may involve areas of the brain that control complex aspects of eating behavior including anticipation and reward, chemosensory perception, and autonomic control of digestion (insular cortex), as well as enteroception and learning/memory (hippocampus).

All-optical neural-net-like image processing with photosensitive nonlinear nematic film

Received June 30, 2003 We demonstrate that some neural-net image-processing operations can be realized in an all-optical manner by use of the natural diffraction property of light in conjunction with the photosensitivity and optical nonlinearities of a transparent thin film. An example of image edge enhancement is illustrated with photosensitive supranonlinear nematic liquid-crystal films.