Tin oxide nanoribbons with vacancy structures in luminescence-sensitive oxygen sensing

Vacancy structures in tin oxide nanoribbons fabricated via thermal evaporation and post-processing are probed by luminescence spectroscopy, and interesting properties that bode well for oxygen sensing are observed. Besides a broad 620-nm band, the fabricated tin oxide nanoribbons show a photoluminescence band at 480 nm when the measurement temperature is <100 K. The blue band appears from nanoribbons synthesized under high oxygen pressure or annealed under oxygen. The dependence suggests that the oxygen interstitial and vacancy densities determine the electronic states that produce the blue band. Calculation of the electron structures based on the density functional theory shows that decreased oxygen vacancies or increased oxygen interstitials enhance the 480-nm band but suppress the 620-nm band. The results reported here indicate that the tin oxide nanoribbons with vacancy structures have potential applications in luminescence-sensitive oxygen sensing.

A multimodal platform for nonlinear optical microscopy and microspectroscopy

Multimodal nonlinear optical microscopy is a valuable tool to study complex biological samples. We present an easy-to-operate approach to perform coherent anti-Stokes Raman scattering (CARS), two-photon fluorescence (TPF), second harmonic generation (SHG), and third-harmonic generation (THG) imaging using a single laser source composed of an 80 MHz femtosecond (fs) laser, an optical parametric oscillator (OPO), and a PPLN crystal for frequency doubling. The platform allows vibrationally resonant CARS imaging of CH-rich myelin sheath in fresh spinal tissues and lipid bodies in live cells. Multimodal nonlinear optical imaging and microspectroscopy analysis of fresh liver tissues are demonstrated.

Excessive S-adenosyl-L-methionine-dependent methylation increases levels of methanol, formaldehyde and formic acid in rat brain striatal homogenates: possible role in S-adenosyl-L-methionine-induced Parkinson's disease-like disorders

AIMS

Excessive methylation may be a precipitating factor for Parkinson's disease (PD) since S-adenosylmethionine (SAM), the endogenous methyl donor, induces PD-like changes when injected into the rat brain. The hydrolysis of the methyl ester bond of the methylated proteins produces methanol. Since methanol is oxidized into formaldehyde, and formaldehyde into formic acid in the body, we investigated the effects of SAM on the production of methanol, formaldehyde and formic acid in rat brain striatal homogenates and the toxicity of these products in PC12 cells.

MAIN METHODS

Radio-enzymatic and colorimetric assays, cell viability, Western blot.

KEY FINDINGS

SAM increased the formation of methanol, formaldehyde and formic acid in a concentration and time-dependent manner. Concentrations of [3H-methyl]-SAM at 0.17, 0.33, 0.67 and 1.34 nM produced 3.8, 8.0, 18.3 and 34.4 fmol/mg protein/h of [3H] methanol in rat striatal homogenates, respectively. SAM also significantly generated formaldehyde and formic acid in striatal homogenates. Formaldehyde was the most toxic metabolite to differentiated PC12 pheochromocytoma cells in cell culture studies, indicating that formaldehyde formed endogenously may contribute to neuronal damage in excessive methylation conditions. Subtoxic concentration of formaldehyde decreased the expression of tyrosine hydroxylase, the limiting factor in dopamine synthesis. Formaldehyde was more toxic to catecholaminergic PC12 cells than C6 glioma cells, indicating that neurons are more vulnerable to formaldehyde than glia cells.

SIGNIFICANCE

We suggest that excessive carboxylmethylation of proteins might be involved in the SAM-induced PD-like changes and in the aging process via the toxic effects of formaldehyde.

Cardioprotection of sevoflurane postconditioning by activating extracellular signal-regulated kinase 1/2 in isolated rat hearts

AIM

The activation of extracellular signal-regulated kinase (ERK)1/2 protects against ischemic-reperfusion injury. Whether ERK1/2 mediates the cardioprotection of sevoflurane postconditioning is unknown. We tested whether sevoflurane postconditioning produces cardioprotection via an ERK1/2-dependent mechanism.

METHODS

In protocol 1, Langendorff-perfused Sprague-Dawley rat hearts (n=84, 12 per group), with the exception of the Sham group, were subjected to 30 min ischemia followed by 90 min reperfusion and were assigned to the untreated (control) group, followed by 4 cycles of ischemic postconditioning (25 s of each), 3% (v/v) sevoflurane postconditioning (for 5 min and 10 min of washout), and the PD98059 solvent DMSO (<0.2%), ERK1/2 inhibitor PD98059 (20 micromol/L), and Sevo+PD administration. Left ventricular hemodynamics and coronary flow at 30 min of equilibrium were recorded at 30, 60, and 90 min of reperfusion, respectively. Acute infarct size was measured by triphenyltetrazolium chloride staining. The configuration of mitochondria was observed by an electron microscope. Western blot analysis was used to determine the contents of cytosolic and mitochondrial cytochrome c at the end of reperfusion. In protocol 2, after 15 min of reperfusion, the expression of total and phosphorylated forms of ERK1/2 and its downstream target p70S6K was determined by Western blotting.

RESULTS

No differences in baseline hemodynamics were observed among the experimental groups (P>0.05). After reperfusion, compared with the control group, sevoflurane postconditioning and ischemic postconditioning significantly(P<0.05) improved functional recovery and largely (P<0.05) decreased myocardial infarct size (22.9%+/-4.6% and 21.2%+/-3.8%, vs 39.4%+/- 5.7%, both P<0.05). Sevoflurane-mediated protection was abolished by PD98059.

CONCLUSION

Anesthetic postconditioning by sevoflurane effectively protects against reperfusion damage by activating ERK1/2 in vitro.

Fast release of lipophilic agents from circulating PEG-PDLLA micelles revealed by in vivo forster resonance energy transfer imaging

Understanding the in vivo behavior of nanoparticles is critical for the translation of nanomedicine from laboratory research to clinical trials. In this work, in vivo Forster resonance energy transfer (FRET) imaging was employed to monitor the release of hydrophobic molecules from circulating poly(ethylene glycol)-poly( D, L-lactic acid) (PEG-PDLLA) micelles. A lipophilic FRET pair (DiIC(18) and DiOC(18)) was physically entrapped into micelle cores by mimicking the loading of hydrophobic drugs. The FRET efficiency was found significantly reduced within 15 min after intravenous injection, implying that DiIC(18) and DiOC(18) quickly escaped from the circulating micelles. FRET spectroscopy studies further demonstrated that alpha- and beta-globulins were major factors for the observed fast release, while gamma-globulins, albumin, and red blood cells played minor roles. These results provide useful information for developing blood-stable micelles to deliver hydrophobic drugs to the target site via prolonged circulation and extravasation from the vascular system.

A process evaluation of the implementation of a computer-based, health provider-delivered HIV-prevention intervention for HIV-positive men who have sex with men in the primary care setting

There is increasing interest in using healthcare providers to deliver HIV-prevention services to their patients. Unfortunately, lack of counselling skills and time constraints within busy clinics serve as barriers to such efforts. The Providers Advocating for Sexual Health Initiative (PASHIN) study used state-of-the-art computer technology to assess each participant's risk behaviours and to determine the patient's readiness for changing each behaviour. The computer synthesized the participant-entered data, determined the targeted risk behaviour and printed a behavioural theory-based provider advice sheet and a 3-point patient prescription for the targeted risk behaviour. Since the intervention does not require providers to spend time performing a detailed sexual-risk assessment and it does not require providers to have received extensive counselling training, it has the potential to minimize some of the barriers associated with provider-delivered interventions. Thus, the purpose of this process evaluation was to assess how the PASHIN intervention was implemented in the field, including issues such as the fidelity of implementation and health providers' views on and experience with implementing the intervention. Overall, the results demonstrated that the computer-based, provider-delivered intervention was successfully delivered by providers within the context of regularly scheduled treatment sessions with HIV-positive men who have sex with men (MSM) patients. The majority of providers (79.4%) and patients (83.5%) reported that the quality of HIV-prevention services delivered during these sessions was 'good'. The majority of the providers also reported that they had received adequate training, felt more confident in communicating HIV-prevention issues with their patients and provided more HIV-prevention counselling to their patients, due to the project. However, the experience of delivering HIV-prevention counselling during an 18-month period did not appear to change providers' attitudes toward a provider-delivered HIV-prevention intervention nor their belief in the effectiveness of HIV prevention in general. Future studies should focus on how to enhance providers' acceptance and commitment to delivering HIV-prevention counselling to their patients during the clinic visit.

Plankton community composition in the Three Gorges Reservoir Region revealed by PCR-dGGE and its relationships with environmental factors

To explore the relationships between community composition and the environment in a reservoir ecosystem, plankton communities from the Three Gorges Reservoir Region were studied by PCR-denaturing gradient gel electrophoresis fingerprinting. Bacterial and eukaryotic operational taxonomic units (OTUs), generated by DGGE analysis of the PCR-amplified 16S and 18S rRNA genes, were used as surrogates for the dominant "biodiversity units". OTU composition among the sites was heterogeneous; 46.7% of the total bacterial OTUs (45) and 64.1% of the eukaryotic OTUs (39) were identified in less than half of the sampling sites. Unweighted pair group method with arithmetic averages (UPGMA) clustering of the OTUs suggested that the plankton communities in the Xiangxi River sites were not always significantly different from those from the Yangtze River sites, despite clear differences in their environmental characterizations. Canonical correspondence analysis (CCA) was applied to further investigate the relationships between OTU composition and the environmental factors. The first two CCA ordination axes suggested that the bacterial community composition was primarily correlated with the variables of NO(3-)-N, dissolved oxygen (DO), and SiO3(2-)-Si, whereas, the eukaryotic community was mainly correlated with the concentrations of DO, PO4(3-)-P, and SiO3(2-)-Si.

The Role of 3-O-Methyldopa in the Side Effects of l-dopa

Long-term treatment of L-dopa for Parkinson's disease (PD) patients induces adverse effects, including dyskinesia, on-off and wearing-off symptoms. However, the cause of these side effects has not been established to date. In the present study, therefore, 3-O-methyldopa (3-OMD), which is a major metabolite of L-dopa, was tested to determine whether it plays a role in the aforementioned adverse effects. The effects of 3-OMD on the dopaminergic nervous system in the brain were investigated, by examining behavioral, biochemical, and cellular changes in male Sprague-Dawley rats and catecholamine-producing PC12 neuronal cells. The results revealed that the intracerebroventricular (icv) injection of 1 micromol of 3-OMD impaired locomotor activities by decreasing movement time (MT), total distance (TD), and the number of movement (NM) by 70, 74 and 61%, respectively. The biochemical analysis results showed that a single administration of 1 micromole of 3-OMD decreased the dopamine turnover rate (DOPAC/DA) by 40.0% in the rat striatum. 3-OMD inhibited dopamine transporter and uptake in rat brain striatal membranes and PC12 cells. The subacute administration of 3-OMD (5 days, icv) also significantly impaired the locomotor activities and catecholamine levels. 3-OMD induced cytotoxic effects via oxidative stress and decreased mitochondrial membrane potential in PC12 cells, indicating that 3-OMD can damage neuronal cells. Furthermore, 3-OMD potentiated L-dopa toxicity and these toxic effects induced by both 3-OMD and L-dopa were blocked by vitamin E (alpha-tocopherol) in PC12 cells, indicating that 3-OMD may increase the toxic effects of L-dopa to some extent by oxidative stress. Therefore, the present study reveals that 3-OMD accumulation from long-term L-dopa treatment may be involved in the adverse effects of L-dopa therapy. Moreover, L-dopa treatment might accelerate the progression of PD, at least in part, by 3-OMD.

Multiple variants in vascular endothelial growth factor (VEGFA) are risk factors for time to severe retinopathy in type 1 diabetes: the DCCT/EDIC genetics study

OBJECTIVE

We sought to determine if any common variants in the gene for vascular endothelial growth factor (VEGFA) are associated with long-term renal and retinal complications in type 1 diabetes.

RESEARCH DESIGN AND METHODS

A total of 1,369 Caucasian subjects with type 1 diabetes from the Diabetes Control and Complications Trial (DCCT)/Epidemiology of Diabetes Interventions and Complications (EDIC) Study had an average of 17 retinal photographs and 10 renal measures over 15 years. In the DCCT/EDIC, we studied 18 single nucleotide polymorphisms (SNPs) in VEGFA that represent all linkage disequilibrium bins (pairwise r(2) > or = 0.64) and tested them for association with time to development of severe retinopathy, three or more step progression of retinopathy, clinically significant macular edema, persistent microalbuminuria, and severe nephropathy.

RESULTS

In a global multi-SNP test, there was a highly significant association of VEGFA SNPs with severe retinopathy (P = 6.8 x 10(-5))-the four other outcomes were all nonsignificant. In survival analyses controlling for covariate risk factors, eight SNPs showed significant association with severe retinopathy (P < 0.05). The most significant single SNP association was rs3025021 (hazard ratio 1.37 [95% CI 1.13-1.66], P = 0.0017). Family-based analyses of severe retinopathy provide evidence of excess transmission of C at rs699947 (P = 0.029), T at rs3025021 (P = 0.013), and the C-T haplotype from both SNPs (P = 0.035). Multi-SNP regression analysis including 15 SNPs, and allowing for pairwise interactions, independently selected 6 significant SNPs (P < 0.05).

CONCLUSIONS

These data demonstrate that multiple VEGFA variants are associated with the development of severe retinopathy in type 1 diabetes.

Characterization of the pH of folate receptor-containing endosomes and the rate of hydrolysis of internalized acid-labile folate-drug conjugates

Despite the widely accepted assumption that most endosomal compartments are acidic, evaluation of the efficiency of pH-dependent drug release from a ligand-targeted drug conjugate during receptor-mediated endocytosis is lacking. Therefore, we have characterized the kinetics of pH-dependent drug release from a model folate-drug conjugate during folate receptor (FR)-mediated endosomal trafficking. For this purpose, we synthesized an acid-labile folate-fluorescence resonance energy transfer reporter (ALFR) that emits green fluorescence (BODIPY FL, 6-((4,4-difluoro-5,7-dimethyl-4-bora-3a,4a-diazas-indacene-3-propionyl)amino)hexanoic acid) only after acid-catalyzed hydrolysis of the acyl hydrazone linker. In a cell-free system, cleavage of ALFR was found to be efficient only at acidic pH values (t1/2=1.95, 4.63, and 75 h at pH 4, 5, and 6, respectively) and essentially resistant to hydrolysis at pH 7. Curiously, when applied to folate receptor-expressing cancer cells, the acid-labile folate-linked probe exhibited little or no recovery of BODIPY FL fluorescence (green), even after 55 h of incubation, arguing very inefficient cleavage within the FR endocytic pathway. To understand this unanticipated observation, we measured the pH of FR-containing endosomes using ratiometric fluorescence microscopy and observed that most FR+ endosomes are only mildly acidic (average approximately pH 6.5). Taken together, these data argue that the FR-trafficking pathway does not involve acidic compartments and that acyl hydrazone linkers may constitute a poor option for FR-mediated drug delivery.

Evaluation of disulfide reduction during receptor-mediated endocytosis by using FRET imaging

Despite functional evidence for disulfide bond-reducing activity in endosomal compartments, the mechanistic details pertaining to such process (e.g., kinetics and sites of disulfide reduction) remain largely controversial. To address these questions directly, we have synthesized a previously uncharacterized fluorescent folate conjugate, folate-(BODIPY FL)-SS-rhodamine (folate-FRET), that changes fluorescence from red to green upon disulfide bond reduction. Using this construct, we have observed that disulfide reduction: (i) occurs with a half-time of 6 h after folate-FRET endocytosis, (ii) begins in endosomes and does not depend significantly on redox machinery located on the cell surface or within the lysosome or the Golgi apparatus, (iii) occurs independently of endocytic vesicle trafficking along microtubules, and (iv) yields products that are subsequently sorted into distinct endosomes and trafficked in different directions. Finally, colocalization of folate and transferrin receptors suggest that conclusions derived from this study may apply to other endocytic pathways.

Distribution of phytoplankton in the Three-Gorge Reservoir during rainy and dry seasons

After damming of the Yangtze River, in order to explore the impacts of the Three-Gorge Dam (TGD) on the aquatic ecosystem, phytoplankton composition, abundance and biomass spatial distribution were studied in the Three-Gorge Reservoir (TGR), and the closest upstream anabranch Xiangxi River, which is 38 km away from the Three-Gorge Dam (TGD) during August (rainy season) 2004 and April (dry season) 2005. In surveys, 6 transects (2 downstream and 4 cross-stream) and 25 stations have been investigated and 314 samples were collected from the surface to the river bed with water samplers. In TGR, 63 taxa and 60 taxa were identified in the rainy and dry seasons, respectively. In the Xiangxi River, 39 taxa were observed in the rainy and dry seasons. Algal blooms occurred in the Xiangxi River and at the influx region of the Yangtze and Xiangxi in both seasons, but had not occurred prior to damming. In the rainy season, the dominant species was Chroomonas acuta with 1.84x10(7) cells l-1, and in the dry season the dominant species were Asterionella formosa and Cryptomonas ovata with 1.34x10(7) cells l-1 and 1.79x10(6) cells.l-1, respectively. In the main channel of TGR, there were no significant correlations between phytoplankton abundance and the concentrations of the main soluble nutrients. In the Xiangxi River, significant negative correlations were observed between phytoplankton abundance and nitrate (Spearman, p<0.01, n=21), phosphate (Spearman, p<0.05, n=21) and silicate (Spearman, p<0.01, n=21) in the rainy season, and similar correlations were also observed with nitrate (Spearman, p<0.05, n=28) and silicate (Spearman, p<0.01, n=28), but not with phosphate in the dry season. Since the damming of the Yangtze River, eutrophication in the anabranch within the backwater has occurred and become severe, and the frequency of algal bloom within TGR and anabranches is expected to increase.

The Role of Phospholipid Methylation in 1-Methyl-4-Phenyl-Pyridinium Ion (MPP+)-Induced Neurotoxicity in PC12 Cells

Excessive methylation has been proposed to be involved in the pathogenesis of Parkinson's disease (PD), via mechanisms that involve phospholipid methylation. Meanwhile, 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) was found to stimulate phospholipid methylation via the oxidized metabolite, 1-methyl-4-phenyl-pyridinium (MPP+), in the rat brain and liver tissues. In the present study, we investigated the effect of MPP+ on phosphatidylethanolamine N-methyltransferases (PENMT) and the potential role of this pathway in MPP(+)-induced neurotoxicity using PC12 cells. The results obtained indicate that MPP+ stimulated phosphatidylethanolamine (PTE) methylation to phosphatidylcholine (PTC) and correspondingly increased the formation of lysophosphatidylcholine (lyso-PTC). Moreover, the addition of S-adenosylmethionine (SAM) to the cell culture medium increases MPP(+)-induced cytotoxicity. The incubation of 1mM MPP+ and various concentrations of SAM (0-4 mM) decreased the viability of PC12 cells from 80% with MPP+ alone to 38% viability with 4 mM SAM for 4 days incubation. The data also revealed that the addition of S-adenosylhomocysteine (SAH), a methylation inhibitor, offered significant protection against MPP(+)-induced cytotoxicity, indicating that methylation plays a role in MPP(+)-induced cytotoxicity. Interestingly, lyso-PTC showed similar actions to MPP+ in causing many cytotoxic changes with at least 10 times higher potency. Lyso-PTC induced dopamine release and inhibited dopamine uptake in PC12 cells. Lyso-PTC also caused the inhibition of mitochondrial potential and increased the formation of reactive oxygen species in PC12 cells. These results indicate that phospholipid methylation pathway might be involved in MPP+ neurotoxicity and lyso-PTC might play a role in MPP(+)-induced neurotoxicity.

Effects of Homocysteine on the Dopaminergic System and Behavior in Rodents

Long-term treatment of levodopa for Parkinson's disease (PD) patients is known to elevate homocysteine level in their plasma. The present study was designed to examine the possible neurotoxic effects of the increased homocysteine level on the dopaminergic system. Homocysteine was administered into Sprague-Dawley male rats intracerebroventricularly or C57BL/6 mice intraperitoneally. Following homocysteine injection the locomotor activities, the levels of dopamine (DA) and its metabolites, 3,4-dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA), and immunohistochemistry of dopaminergic neurons were examined. The results obtained indicate that homocysteine administration (1 or 2 micromol, i.c.v.) into the rat brains for 5 days significantly decreased the locomotor activities and dopamine as well as its metabolites, DOPAC and HVA, in the rat striatal regions. Two different doses of homocysteine (50 and 100mg/100g, i.p. daily) were administered into mice for 36 days to evaluate the effect of systemic treatment of homocysteine on the dopaminergic neurons of the brain. The intraperitoneal injections of two doses of homocysteine significantly increased homocysteine levels in the striatal regions of mouse brains by 21.5 and 39.2%, while reducing dopamine turnover rates in the striatal regions by decreasing (DOPAC+HVA)/DA, 23.7 and 51.6%, respectively. Accordingly, homocysteine decreased locomotor activities significantly by decreasing movement time by 29 and 38%, total distance by 32 and 42%, and numbers of movement by 28 and 41%, respectively. Moreover, homocysteine decreased tyrosine hydroxylase immunoreactivity in substantia nigra of mouse brain. The data obtained indicate that the potential of homocysteine to be toxic to the dopaminergic system. Consequently, long-term levodopa therapy for PD may accelerate the progression of PD, at least in part by elevated homocysteine.

Characterization of a thermostable alkaline phosphatase from a novel species Thermus yunnanensis sp. nov. and investigation of its cobalt activation at high temperature

A thermostable alkaline phosphatase with high specific activity and thermal resistance was purified from a novel species of Thermus sp. named as Thermus yunnanensis sp. nov. The enzyme contains a single peptide with a molecular mass of about 52 kDa on SDS-PAGE analysis and appears to be a homodimer in solution with the molecular mass of 104 kDa. The optimal pH and temperature for its activities are pH 8.0-10.0 and 70-80 degrees C, respectively. The catalytic activities of the enzyme are metal ion dependent, and Mg2+, Zn2+ and Co2+ are the main activators. Among these, Co2+ is the most active stimulator and has unique activation effect at high temperature. Metal binding analysis showed the binding of Mg2+ at the metal binding site was easy to loss in the thermoinactivation, and Co2+ was apt to bind at that site and kept the favorable configuration of catalysis, which would result high activation in the incubation with Co2+ at high temperature. According to this study, a model was proposed for the explanation of the activation and the results of actual experiments demonstrated the validity of the model.

Identification of a novel insulin-like growth factor binding protein gene homologue with tumor suppressor like properties

Here we report the identification of a new insulin-like growth factor binding protein homologue, provisionally designated insulin-like growth factor binding related protein-4 (IGFBP-rP4). IGFBP-rP4 was found to be most closely related to IGFBP-7 with 52% amino acid homology and 43% amino acid identity, and shares a similar domain structure. Semi-quantitative RT-PCR expression analysis demonstrated a pattern of downregulation of this gene in multiple tumor samples including lung and colon cancer, compared to matched adjacent normal tissue. Western blotting revealed a protein of approximately 38kDa expressed in both the cell pellet and secreted into the supernatant of transiently transfected Cos-7 cells. Cos-7 supernatants containing IGFBP-RP4 protein were observed to suppress the growth of HeLa cells in culture compared to vector controls. IGFBP-RP4 directly transiently transfected into HeLa cells also further confirmed the growth suppressive properties of this protein. Together these data suggest that IGFBP-RP4 may be a novel putative tumor suppressor protein.

Inhibitory Effects of Lysophosphatidylcholine on the Dopaminergic System

Lysophosphatidylcholine (lyso-PTC) is formed by phospholipase A2 (PLA2) from phosphatidylcholine (PTC), that is produced through phosphatidylethanolamine (PTE) methylation. 1-Methyl-4-phenyl-pyridinium (MPP+), a Parkinson's disease (PD) inducing agent, and S-adenosylmethionine (SAM), a biological methyl donor, increase lyso-PTC formation and both induce PD-like changes in animal models. In the current study, we investigated the effect of lyso-PTC on the dopaminergic system to determine the modulating role of lyso-PTC in dopaminergic neurotransmission. The results of these experiments show that lyso-PTC has a remarkable inhibitory effect on dopamine D1 and D2 receptor binding activities in the striatal membrane prepared from Sprague-Dawley rats. Lyso-PTC decreased the Bmax values of both D1 and D2 receptor binding activities. The Kd values for D1 and D2 receptors were not changed, but lyso-PTC also inhibited dopamine transporter and decreased striatal dopamine turnover rate. MPP+ showed similar, but less potent effects. The current studies suggest that lyso-PTC significantly impair the dopaminergic system and might play a role in MPP+ and SAM induced PD-like changes through its inhibitory effects on dopaminergic neurotransmission.

The inhibitory role of methylation on the binding characteristics of dopamine receptors and transporter

Excess methylation has been suggested to play a role in the pathogenesis of Parkinson's disease (PD), since the administration of S-adenosylmethionine (SAM), a biological methyl donor, induces PD-like changes in rodents. It was proposed that SAM-induced PD-like changes might be associated with its ability to react with the dopaminergic system. In the present study the effects of SAM on dopamine receptors and transporters were investigated using rats and cloned dopamine receptor proteins. Autoradiographic examination of SAM indicated its tendency to be localized and accumulated in rat striatal region after the intracerebroventricular injection into rat brain. Moreover, results showed that SAM significantly decreased dopamine D1 and D2 receptor binding activities by decreasing the Bmax and increasing the Kd values. At concentrations of 0.1, 0.25 and 0.5 mM, SAM was able to reduce the Bmax from the control value of 848.1 for dopamine D1-specific ligand [3H] SCH 23390 to 760.1, 702.6 and 443.0 fmol/mg protein, respectively. At the same concentrations, SAM was able to increase the Kd values from 0.91 for the control to 1.06, 3.84 and 7.01 nM of [3H] SCH 23390, respectively. The effects of SAM on dopamine D2 binding were similar to those of dopamine D1 binding. SAM also decreased dopamine transporter activity. The interaction of SAM with dopamine receptor proteins produced methanol from methyl-ester formation and hydrolysis. We propose that the SAM effect might be related to its ability to react with dopamine receptor proteins through methyl-ester formation and methanol production following the hydrolysis of the carboxyl-methylated receptor proteins.

[Nutrients regeneration speed of sediment in harmful algae blooms (HAB) area of East China Sea]

The fluxes of dissolved nutrients at sediment-water interface were investigated at 4 stations in the HAB area of East China Sea in May 2001 and May 2002. The benthic fluxes of nutrients were determined by incubating the sediment core samples with bottom seawater bubbled with air or nitrogen. The transfer of nutrients was more active under anoxic condition. The fluxes of dissolved nutrients were generally high at the stations close to the coast. The sediment was the source of SiO3(2-), which accounted for 6% of primary production. For DIN and PO4(3-), the sediment was the sink. DIN and PO4(3-) adsorbed by sediment accounted for 5.9% and 67% of the riverine DIN and PO4(3-) inputs, respectively, and the inputs of SiO3(2-) accounted for 7.8%.

[Nutrient elements in the atmospheric wet deposition in Changjiang River estuary]

In order to study the effects of atmospheric wet deposition on red tide, five kinds of nutrient elements were measured with 64 rainwater samples collected at Shengsi Archipelago from May 2000 to April 2001. The results showed that there were obvious differences between monthly average concentrations, due to the different resource and precipitation. The variation of seasonal fluxes suggested that the wet deposition might cause red tide except in winter. The annual concentrations of NO3-N, NH4(+)-N, NO2(-)-N, PO4(3-)-P and SiO3(2-)-Si were 20.23, 30.14, 0.11, 0.045 and 3.43 mumol.L-1, respectively, and their annual fluxes were 2.67 x 10(8), 3.98 x 10(8), 0.014 x 10(8), 0.0059 x 10(8) and 0.45 x 10(8) mol, respectively. Compared with river input, they were much more smaller.

Farnesol for aerosol inhalation: nebulization and activity against human lung cancer cells

PURPOSE

A nebulized aerosol formulation of the anti-cancer agent farnesol is developed and shown to induce cell death of human lung cancer cells in vitro.

METHODS

A nebulized farnesol formulation containing polysorbate 80 (Tween 80) is developed. The measurements of the aerosol properties during nebulization were used as input for a mathematical model of airway surface liquid in the lung of an average adult, to estimate the airway surface liquid drug concentration of the deposited farnesol. Cytotoxicity of the formulations was measured in vitro on non-small cell lung cancer cells (H460 and A549).

RESULTS

As much as 100% of lung cancer cytotoxicity can be achieved by using Pari LC Star and LC Plus nebulizers. The estimated airway surface liquid concentrations of the deposited farnesol reveal that the IC50 of the nebulized farnesol can be achieved over the entire tracheobronchial region, using the above Pari nebulizers with a volume fill of 5 ml.

CONCLUSIONS

Drug concentrations higher than IC50 in the airway surface liquid are predicted with our methods, suggesting in vivo trials of a formulation may be warranted with these particular nebulizers.

[HLA genotyping by automatic semi-quantitative polymerase chain reaction-reverse sequence specific oligonucleotide]

OBJECTIVE

To explore a HLA genotyping method that can be used for organ transplantation tissue typing, and especially for establishing hemopoietic stem cell bank and the cord blood stem cell bank by analyzing the PCR-DNA.

METHODS

Modified automatic method based on semi-quantitative amplification system of HLA-I, I allele genotyping was established using reverse sequence-specific oligonucleotide with polymerase chain reaction (PCR-RSSO), and was compared with PCR (using sequence specific primer, PCR-SSR) and manual PCR-RSSO in terms of the accuracy, resolution, and the quantity of DNA consumption. A total of 635 blood samples were genotyped with HLA-A, B, C, DR and DQ alleles using auto semi-quantitative PCR-RSSO, 166 of which were also examined using PCR-SSP and manual PCR-RSSO simultaneously. RDSULTS: The success rate of automatic semi-quantitative PCR-RSSO, PCR-SSP and manual PCR-RSSO was 98.4% (3 124/3 175), 98.8% (656/664) and 88.3% (732/830) respectively, with no significant difference between the former 2 as indicated by X2 test (P>0.05). Auto semi-quantitative PCR-RSSO, however, yielded significantly higher success rate than manual PCR-RSSO (P<0.05).

CONCLUSION

PCR-RSSO is capable of identifying 706 alleles of HLA-I, II antigens which amounts to 75.43% of the 936 alleles published by WHO in 2000, with intermediate to high resolution, even in the case of the homozygote. The hybridization results documenting the original data can be conveniently preserved. This method therefore possesses the merits of low expenses, low labor intensity, and rapid processing of large number of samples.

The role of recombination activating gene (RAG) reinduction in thymocyte development in vivo

Assembly of T cell receptor (TCR)alpha/beta genes by variable/diversity/joining (V[D]J) rearrangement is an ordered process beginning with recombination activating gene (RAG) expression and TCRbeta recombination in CD4(-)CD8(-)CD25(+) thymocytes. In these cells, TCRbeta expression leads to clonal expansion, RAG downregulation, and TCRbeta allelic exclusion. At the subsequent CD4(+)CD8(+) stage, RAG expression is reinduced and V(D)J recombination is initiated at the TCRalpha locus. This second wave of RAG expression is terminated upon expression of a positively selected alpha/beta TCR. To examine the physiologic role of the second wave of RAG expression, we analyzed mice that cannot reinduce RAG expression in CD4(+)CD8(+) T cells because the transgenic locus that directs RAG1 and RAG2 expression in these mice is missing a distal regulatory element essential for reinduction. In the absence of RAG reinduction we find normal numbers of CD4(+)CD8(+) cells but a 50-70% reduction in the number of mature CD4(+)CD8(-) and CD4(-)CD8(+) thymocytes. TCRalpha rearrangement is restricted to the 5' end of the Jalpha cluster and there is little apparent secondary TCRalpha recombination. Comparison of the TCRalpha genes expressed in wild-type or mutant mice shows that 65% of all alpha/beta T cells carry receptors that are normally assembled by secondary TCRalpha rearrangement. We conclude that RAG reinduction in CD4(+)CD8(+) thymocytes is not required for initial TCRalpha recombination but is essential for secondary TCRalpha recombination and that the majority of TCRalpha chains expressed in mature T cells are products of secondary recombination.

Clinical analysis and literature review of massive duodenal diverticular bleeding

A duodenal diverticulum (DD) appears in 2.5% of upper gastrointestinal (UGI) examinations and up to 22% of endoscopic retrograde cholangiopancreaticographies (ERCP) and autopsies. Most of these patients are asymptomatic, but the lesion is occasionally associated with bleeding, inflammation, perforation, obstruction of the duodenum or biliary-pancreatic duct (or both), fistula formation in the bile duct, and bezoar formation inside the diverticulum. A total of 816 patients have undergone ERCP examination at our institution since January 1987, and 100 (12.25%) of them have DD. Seven (7%) patients presented with bloody or tarry stools from massive UGI bleeding followed by shock. Only two could be diagnosed by UGI endoscopy preoperatively. The lesions were demonstrated in angiographic studies in another four cases. However, only one was correctly interpreted and one required reoperation after a correct repeat endoscopic finding. The lesions in the other two patients were identified by thorough exploration during laparotomy. The remaining case was diagnosed by intraoperative endoscopy via pyloroduodenotomy. Six underwent surgical intervention, and one was successfully treated by expectant treatment. Three (50%) had leakage from the duodenotomy but recovered uneventfully with conservative treatment. In conclusion, we believe that DD bleeding is more frequent than usually thought. A high index of suspicion should be raised in cases of UGI bleeding when more obvious and common causes have been excluded by routine endoscopy. Aggressive but careful endoscopic examination combined with accurate angiography can help us diagnose most of the cases preoperatively. Diverticulectomy is an effective surgical procedure, though it is associated with a considerable leakage rate. The morbidity is minimal if we can identify the lesion earlier and evacuate the lesion without delay.

Proton-lithium binding behavior of tris(2-((pyrid-2-ylmethyl)uredio)ethyl)amine

Tris(2-((pyrid-2-ylmethyl)uredio)ethyl)amine (2) and its perchlorate salt, 2.HClO(4), bind with Li+ in nitromethane in a 1:1 fashion. The stability constants of K(Li+) and K(H)(Li+) were found to be 112 +/- 25 and 130 +/- 30 M(-)(1) in CD(3)NO(2), respectively. Formation of the 1:1 complexes were further evidenced by electrospray ionization mass spectrometry (ESI-MS). The slight increase, or at least the same order of magnitude, of K(H)(Li+) compared to K(Li+) points to a remarkable preorganization of the protonated podand in 2.HClO(4), that essentially overcomes the increased Columbic repulsion occurring on complexation to Li+.

Effect of radiation on cytokine and cytokine receptor messenger-RNA profiles in p53 wild and mutated human glioblastoma cell lines

OBJECTIVE

Glioblastoma cells produce cytokines with proinflammatory or immunosuppressive properties, or both, which, in addition to altered p53 gene expression, have been shown to be associated with glioblastoma resistance to radiotherapy. The reported data concerning cytokines have been isolated and sometimes discordant, and a comprehensive profile analysis of cytokines and their corresponding receptors in irradiated glioblastomas has received limited attention. The object of this study was to test the hypothesis that radiation alone in clinically relevant doses would not significantly alter expression of endogenous cytokines and their receptors in human glioblastoma celll ines with wild-type and mutant p53.

DESIGN AND METHOD

Culture specimens of 4 glioblastoma cell lines of different p53 gene expression (U87, U118, U251, U373) were irradiated with cobalt 60 at a dose of 10 Gy. After 48 hours, radiosensitivity was defined through a colony formation assay, cell cycle distribution was analyzed by flow cytometry, and cytokine and cytokine receptor messenger-RNA (mRNA) profiles were defined with an RNase protection assay. Different single doses of radiation at varying time intervals after culture were applied also to wild-type p53 cell lines.

RESULTS

All cell lines were relatively radioresistant at lower doses of 1 and 2 Gy. Immunosuppressive cytokine and cytokine receptor mRNA of the Th2 (IL-13Ralpha, IL-4) and Th3 family (TGF-beta1, 2 and 3, TGF-betaRI and RII) were expressed. In contrast, only 2 proinflammatory Th1 cytokine receptor genes (IFN-gammaRa and IFN-gammaRbeta), but no significant Th1 cytokine gene expression, were detected. Even though the population examined included a large fraction of reproductively dead cells, cytokine and cytokine receptor mRNA profiles were not altered significantly by irradiation in all cell lines, regardless of the p53 status.

CONCLUSION

These results suggest that cobalt irradiation alone at clinically relevant doses does not significantly alter the cytokine and cytokine receptor profiles in human glioblastoma cell lines.

Genetic interactions between ATM and the nonhomologous end-joining factors in genomic stability and development

DNA ligase IV (Lig4) and the DNA-dependent protein kinase (DNA-PK) function in nonhomologous end joining (NHEJ). However, although Lig4 deficiency causes late embryonic lethality, deficiency in DNA-PK subunits (Ku70, Ku80, and DNA-PKcs) does not. Here we demonstrate that, similar to p53 deficiency, ataxia-telangiectasia-mutated (ATM) gene deficiency rescues the embryonic lethality and neuronal apoptosis, but not impaired lymphocyte development, associated with Lig4 deficiency. However, in contrast to p53 deficiency, ATM deficiency enhances deleterious effects of Lig4 deficiency on growth potential of embryonic fibroblasts (MEFs) and genomic instability in both MEFs and cultured progenitor lymphocytes, demonstrating significant differences in the interplay of p53 vs. ATM with respect to NHEJ. Finally, in dramatic contrast to effects on Lig4 deficiency, ATM deficiency causes early embryonic lethality in Ku- or DNA-PKcs-deficient mice, providing evidence for an NHEJ-independent role for the DNA-PK holoenzyme.

Giant ethmoid osteoma with orbital extension, a nasoendoscopic approach using an intranasal drill

OBJECTIVE

Ethmoid osteoma is a slow-growing, benign, and encapsulated bony tumor. Symptoms occur earlier than with osteomas of the frontal sinus because of the small volume of the ethmoid sinus. Interestingly, orbital extension is uncommon. Treatment remains controversial, with open procedures typically being used. In this article, we present a less invasive yet safe and effective approach to treatment.

STUDY DESIGN

A nasoendoscopic approach using a Stammberger-Saches intranasal drill was developed for treatment of patients with ethmoid osteoma, with or without orbital extension. Between 1995 to 1999, seven patients underwent the new surgical procedure.

METHODS

All procedures were performed under general anesthesia. Using 0 degrees and 30 degrees endoscopes, surface anesthesia of the nasal mucosa was performed, the anterior ethmoid cell was resected, and the whitish osteoma found. The osteoma was drilled out inferolaterally to superomedially. In the patient with orbital extension, a double-ended blunt elevator was used to separate the remaining osteoma from the lamina papyracea and to push the residual osteoma medially toward the nasal septum. With alternate drilling and elevation, the osteoma was gently removed. The surgical site was then packed.

RESULTS

The method successfully treated all patients. There were no major complications. The single patient with orbital extension had mild postoperative periorbital ecchymoses. Nasoendoscopy showed normal epithelialization 4 to 6 weeks after surgery. Computed tomography showed no residual tumors 6 months after surgery.

CONCLUSION

The 30 degrees nasoendoscopic approach using an intranasal drill provides a good operative field and is a safe and effective technique, with the potential to become the treatment of choice in selected cases.

Primary renal sarcoma with inferior vena cava thrombus presenting with tumor rupture

Primary renal sarcoma represents approximately one per cent of all primary tumors of the kidney in adults. We report an unusual case of primary renal sarcoma with inferior vena cava (IVC) thrombus. This patient presented with hemorrhagic shock due to tumor rupture. Emergent radical nephrectomy and vena caval thrombectomy were performed. Histological examination proved a clear cell sarcoma.

Enhanced sensitivity and long-term G2 arrest in hydrogen peroxide-treated Ku80-null cells are unrelated to DNA repair defects

While the Ku complex, comprised of Ku70 and Ku80, is primarily involved in the repair of DNA double-strand breaks, it is also believed to participate in additional cellular processes. Here, treatment of embryo fibroblasts (MEFs) derived from either wild-type or Ku80-null (Ku80(-/-)) mice with various stress agents revealed that hydrogen peroxide (H(2)O(2)) was markedly more cytotoxic for Ku80(-/-) MEFs and led to their long-term accumulation in the G2 phase. This differential response was not due to differences in DNA repair, since H(2)O(2)-triggered DNA damage was repaired with comparable efficiency in both Wt and Ku80(-/-) MEFs, but was associated with differences in the expression of important cell cycle regulatory genes. Our results support the notion that Ku80-mediated cytoprotection and G2-progression are not only dependent on the cell's DNA repair but also may reflect Ku80's influence on additional cellular processes such as gene expression.

Structure of a (Cys3His) zinc ribbon, a ubiquitous motif in archaeal and eucaryal transcription

Transcription factor IIB (TFIIB) is an essential component in the formation of the transcription initiation complex in eucaryal and archaeal transcription. TFIIB interacts with a promoter complex containing the TATA-binding protein (TBP) to facilitate interaction with RNA polymerase II (RNA pol II) and the associated transcription factor IIF (TFIIF). TFIIB contains a zinc-binding motif near the N-terminus that is directly involved in the interaction with RNA pol II/TFIIF and plays a crucial role in selecting the transcription initiation site. The solution structure of the N-terminal residues 2-59 of human TFIIB was determined by multidimensional NMR spectroscopy. The structure consists of a nearly tetrahedral Zn(Cys)3(His)1 site confined by type I and "rubredoxin" turns, three antiparallel beta-strands, and disordered loops. The structure is similar to the reported zinc-ribbon motifs in several transcription-related proteins from archaea and eucarya, including Pyrococcus furiosus transcription factor B (PfTFB), human and yeast transcription factor IIS (TFIIS), and Thermococcus celer RNA polymerase II subunit M (TcRPOM). The zinc-ribbon structure of TFIIB, in conjunction with the biochemical analyses, suggests that residues on the beta-sheet are involved in the interaction with RNA pol II/TFIIF, while the zinc-binding site may increase the stability of the beta-sheet.

Experimental examination of the effects of atmospheric wet deposition on primary production in the Yellow Sea

The effects of atmospheric wet deposition on primary production in the coastal Yellow Sea were examined by in situ incubation experiments in August, 1997. Phytoplankton species flourished in response to nutrient additions and chlorophyll-a (Chl-a) increased significantly when rainwater was added. Concentration of Chl-a increased 2.6 times with the addition of 10% (v/v) rainwater. In a coastal eutrophic region like Jiaozhou Bay, the impact of atmospheric wet deposition is negligible. However, the N/P ratio ranged from 22:1 to 80:1, indicating P limitation of photosynthesis in the Yellow Sea. During field observations, high N and low P rainwater was observed to be transported into the oligotrophic central Yellow Sea. Ammonium was used by phytoplankton in preference to nitrate, and Fe stimulated nutrient uptake by phytoplankton. Rainwater increased the Chl-a growth more than a single nutrient owing to the abundance of both plant and trace nutrients in the rainwater. A negative exponent relationship may exist between the impact of rainwater and total nutrient quality of the water in influencing phytoplankton growth.

DNA repair protein Ku80 suppresses chromosomal aberrations and malignant transformation

Cancer susceptibility genes have been classified into two groups: gatekeepers and caretakers. Gatekeepers are genes that control cell proliferation and death, whereas caretakers are DNA repair genes whose inactivation leads to genetic instability. Abrogation of both caretaker and gatekeeper function markedly increases cancer susceptibility. Although the importance of Ku80 in DNA double-strand break repair is well established, neither Ku80 nor other components of the non-homologous end-joining pathway are known to have a caretaker role in maintaining genomic stability. Here we show that mouse cells deficient for Ku80 display a marked increase in chromosomal aberrations, including breakage, translocations and aneuploidy. Despite the observed chromosome instabilities, Ku80-/- mice have only a slightly earlier onset of cancer. Loss of p53 synergizes with Ku80 to promote tumorigenesis such that all Ku80-/- p53-/- mice succumb to disseminated pro-B-cell lymphoma before three months of age. Tumours result from a specific set of chromosomal translocations and gene amplifications involving IgH and c-Myc, reminiscent of Burkitt's lymphoma. We conclude that Ku80 is a caretaker gene that maintains the integrity of the genome by a mechanism involving the suppression of chromosomal rearrangements.

Acute colonic intramural hematoma due to blunt abdominal trauma

Trauma to the colon is uncommon and accounts for only 3-5% of all blunt abdominal injuries. Among them, intramural hematoma of the colon is a rare complication and the acute form is rarer than the chronic form. We report a 37-year-old man who presented with abdominal pain followed by intestinal obstruction due to a blunt trauma. The initial diagnosis was done by sonography and proved by computed tomography (CT). Abdominal sonography also detected an increment in the size of the hematoma with progressive abdominal cramping pain that prompted urgent laparotomy. Ileocolic segmental resection with end-to-end ileocolostomy was performed and the patient recovered uneventfully. Based on our experience with a patient suffering from an intramural colonic hematoma following blunt abdominal trauma (BAT) and based on a review of the literature, we discuss the different clinical manifestations, difficulties of diagnosis, and different treatment modalities of this disease entity. We conclude that acute colonic hematoma can be diagnosed by sonography and/or CT in contrast to the early reported cases, in the pre-CT era, when they could only be diagnosed at laparotomy. Endoscopy may also be helpful for diagnosis in some cases. Although expectant therapy may be successful in some cases, the majority of the cases may need operation.

Endoscopic carpal tunnel release

BACKGROUND

Endoscopic carpal tunnel release was developed by Okutsu and Chow in 1989. Many reports have indicated that endoscopic carpal tunnel release diminishes postoperative pain and accelerates the recovery time.

METHODS

In a series of 1278 carpal tunnel release procedures (in 948 patients), 1214 were performed with a modified Menon endoscopic method and the remaining 64 with an open procedure. The patients with idiopathic carpal tunnel syndrome were followed for at least 3 months.

RESULTS

Of the endoscopic release patients, 80.9% recovered grip strength equal to or greater than preoperative levels within 4 weeks, whereas in the open procedure group, the rate was only 59.3%. The difference was statistically significant (p = 0.00011). An immediate complication was one median motor nerve severance. There were 24 conversions to a conventional open procedure during endoscopic release. In the endoscopic group, 81% developed scar tenderness over the thenar crease, 31% developed new sensory disturbance, and 4% developed pillar pain.

CONCLUSION

Endoscopic release facilitated the recovery of grip strength and diminished the frequency of scar tenderness. However, neurovascular injury should be carefully prevented.

Differential binding of proteins to peroxisomes in rat hepatoma cells: unique association of enzymes involved in isoprenoid metabolism

Farnesyl diphosphate synthase (FPPS: EC2.5.1.10), a key enzyme in isoprenoid metabolic pathways, catalyzes the synthesis of farnesyl diphosphate (FPP) an intermediate in the biosynthesis of both sterol and non-sterol isoprenoid end products. The localization of FPPS to peroxisomes has been reported (Krisans, S. K., J. Ericsson, P. A. Edwards, and G. A. Keller. 1994. J. Biol. Chem. 269: 14165;-14169). Using indirect immunofluorescence and immunoelectron microscopic techniques we show here that FPPS is localized predominantly in the peroxisomes of rat hepatoma H35 cells. However, the partial release of 60;-70% of cellular FPPS activity is observed by selective permeabilization of these cells with digitonin. Under these conditions, lactate dehydrogenase, a cytosolic enzyme, is completely released whereas catalase, a known peroxisomal enzyme, is fully retained. Digitonin treatment of H35 cells differentially affects the release of other peroxisomal enzymes involved in isoprenoid metabolism. For instance, mevalonate kinase and phosphomevalonate kinase are almost totally released (95% and 91%, respectively), whereas 3-hydroxy-3-methylglutaryl-CoA reductase is fully retained. Indirect immunoflourescence studies indicate that FPPS is localized in peroxisomes of Chinese hamster ovary (CHO)-K1 cells but is dispersed in the cytosol of ZR-82 cells, a mutant that lacks peroxisomes. Unlike in H35 cells, FPPS is completely released upon digitonin permeabilization of CHO-K1 and ZR-82 cells. In contrast, under the same permeabilization conditions, catalase is fully retained in CHO-K1 cells but completely released from ZR-82 cells. These studies indicate that FPPS and other enzymes in the isoprenoid biosynthetic pathways, involved in the formation of FPP, are differentially associated with peroxisomes and may easily diffuse to the cytosol. Based on these observations, the significance and a possible regulatory model in the formation of isoprenoid end-products are discussed.

Correlation of clinical and ultrasonographic features in congenital muscular torticollis

OBJECTIVE

To find the relationship between the ultrasonographic pictures and the clinical features of patients with congenital muscular torticollis (CMT).

DESIGN

Prospective survey of patients with clinically suspected CMT by high-resolution ultrasonography.

SETTING

Rehabilitation department of a tertiary care center.

PARTICIPANTS

Two hundred fifty-six CMT patients, from the ages of 9 days to 16yrs, with a mean follow-up period of 6.7 months.

MAIN OUTCOME MEASURES

Correlation of the ultrasound appearance of the involved sternocleidomastoid (SCM) muscles with clinical features. The pathologic findings in diseased muscles from patients who underwent surgical intervention were also evaluated.

RESULTS

Muscle abnormalities were identified ultrasonographically in 218 CMT patients (85%) and were classified into four types: a fibrotic mass in the involved muscle (type I, 15%); diffuse fibrosis mixing with normal muscle (type II, 77%) and without normal muscle in the involved muscle (type III, 5%); and a fibrotic cord in the involved muscle (type IV, 3%). Compared with type I patients, type IV patients were more likely to undergo surgical treatment (odds ratio = 31.54, p = .0196). Type III patients were more likely to undergo surgical treatment, although this tendency was not statistically significant.

CONCLUSION

Ultrasonography can precisely identify pathologic changes in the involved SCM muscle of CMT patients. Type III and IV patients are more likely to require surgical intervention.

Involvement of farnesyl protein transferase (FPTase) in FcarepsilonRI-induced activation of RBL-2H3 mast cells

Changes in farnesyl protein transferase (FPTase) activity and FPTase beta-subunit protein levels were determined in IgE-sensitized RBL-2H3 mast cells in response to polyvalent antigen administration. Ten minutes after the addition of DNP modified BSA to mast cells, whose high affinity receptor for IgE (FcvarepsilonRI) contained bound anti-DNP IgE, FPTase specific activity increased by 54 +/- 28%. Time course studies showed FPTase specific activity doubled during a 20- to 30-min period after antigen-induced cell aggregation. Also, an increase in FPTase beta-subunit protein during this time ( approximately 30%) was observed; this protein increase was not accompanied by a similar increase in FPTase beta-subunit m-RNA levels. The FcvarepsilonRI aggregation had no significant effect on the activities of other enzymes involved with farnesyl diphosphate (FPP) metabolism: FPP synthase, isopentenyl diphosphate isomerase, geranylgeranyl protein transferase, and squalene synthase. Specific inhibition of FPTase activity by manumycin was studied to determine what role FPTase plays in mast cell activation. Manumycin profoundly inhibited hexosaminidase release in activated cells, indicating FPTase is required for signal transduction involved with protein exocytosis from RBL-2H3 mast cells.

Regulation of bovine interleukin-1 receptors

Interleukin-1 is a key player in inflammation and the immune response. The interleukin-1 family consists of three ligands (IL-1 alpha, IL-1 beta, and the IL-1 receptor antagonist) and two receptors (IL-1RI and IL-1RII). Previous studies suggest a dynamic relationship among these receptors and ligands that regulates the magnitude and extent of IL-1 mediated activities. Our laboratory has cloned and sequenced the bovine type I and II interleukin-1 receptors, and has begun to investigate their regulation in bovine leukocytes in vitro and in vivo. IL-1RI and IL-1RII mRNA levels were upregulated in vitro by various mediators, including dexamethasone, rBoIL-4, rBoGM-CSF, and rHuTNF alpha. Conversely, IL-1RI mRNA levels were down-regulated by IFN-gamma. An in vivo study indicated that IL-1RII mRNA levels increased earlier than IL-1RI mRNA levels in dexamethasone-treated cattle. These findings suggest that early upregulation of IL-1RII, which is a decoy receptor, may be part of the anti-inflammatory action of glucocorticoids. Our investigations suggest that anti-inflammatory agents increase expression of the biologically inactive IL-1RII, as compared with the biologically active IL-1RI, in bovine leukocytes.

Growth hormone receptor and regulation of gene expression in fetal lymphoid cells

The role of growth hormone (GH) in modulating the adult immune response is receiving increased attention; however, its role in the development of immune competence in the fetus has not been defined. In order to begin to address the role of GH in the ontogeny of the immune response. cells from bovine fetal spleen and thymus were examined for GH receptor and responsiveness to GH. Northern analysis and ligand binding studies showed that growth hormone receptor (GHR) was readily detected in early- and mid-gestational fetal thymocytes, but it was less readily detected in thymocytes from older fetuses. In contrast, GHR was easily detected in splenocytes at all fetal ages. Thymocytes and splenocytes from mid-gestational fetuses expressed low levels of cell surface GHR by flow cytofluorometric analysis, and CD4+ and CD8 (single positive) thymocyte subsets were positive. Northern analyses were employed to determine the effects of in vitro GH treatment on expression of several proto-oncogenes, cytokines, and GHR in thymocytes from fetuses at approximately mid-gestation. GH treatment for 30 min down-regulated c-jun and c-fos mRNA approximately 2- and 2.8-fold, respectively. After 6 h treatment, GH increased transcript levels for interleukin (IL)-1alpha, IL-1beta, IL-6, and GM-CSF about 2.5-, 2.2-, 3-, and 2-fold, respectively. GH also down-regulated the expression of its own receptor about 3.2-fold after 8 h of incubation. The presence of GHR in fetal lymphoid cells and its temporal and spatial regulation suggest a potential role for GH in the development and or function of the fetal bovine immune system. Although the mechanism(s) is unclear, our results suggest that GH is intimately involved in lymphocyte function and expression of certain cytokines during a critical period of fetal immune development.

Growth hormone and Pit-1 expression in bovine fetal lymphoid cells

Bovine fetal lymphoid cells were examined for growth hormone (GH) and the transcription factor Pit-1/GHF-1 mRNA. GH and Pit-1/GHF-1 transcripts were detected in thymocytes and splenocytes from fetuses at 60, 90, 120, and 270 d of gestation using reverse transcription-polymerase chain reaction (RT-PCR). Northern analysis indicated that the lymphoid GH mRNA was approximately 350 nucleotides larger than in the pituitary. RT-PCR analysis demonstrated that the coding regions as well as 3' untranslated region of the lymphocyte GH and pituitary transcripts were the same. Analysis of the 5'-untranslated region of the lymphocyte GH mRNA showed that transcription began upstream from the start site in the pituitary gland, suggesting differences in regulation in these tissues. Fetal thymocytes and splenocytes expressed Pit-1/GHF-1 mRNA; however, they contained only the 2.5-kb transcript. The GH and Pit-1/GHF-1 mRNA in fetal lymphoid cells supports the hypothesis that lymphocyte-derived GH may function as an autocrine and/or paracrine factor during the development and maturation of the bovine fetal immune system.

Free tissue transfer for leg reconstruction in children

Twenty-five free tissue transfers for reconstruction after lower limb trauma or release of scar contractures were performed in 23 children over an 8-year period. The ages ranged from 2 to 14 years (mean 7.1 years). Fourteen (61%) patients had major associated injuries. The reconstruction sites were all in the distal leg. The overall vascular success rate was 96%. Three patients underwent re-explorations because of vascular insufficiency. One flap failed and two were salvaged. The causes of vascular complications were considered to be inadequate debridement of an avulsed vessel, venous kinking and inadequate protection of the vascular pedicle. The three cases with vascular insufficiency were children with associated injuries on the ipsilateral leg proximally. Postoperative complications were not uncommon (28%). Six of the seven complications occurred in patients with major associated injuries. The mean follow-up was 57 months. Long-term problems such as a limping gait, frequent flap ulcers, toe contracture or a bulky flap were common. Our results suggest that free tissue transfer is reliable and safe for the reconstruction of major leg injuries in children. Associated injuries proximal to the reconstructed defects on the ipsilateral leg predispose to more vascular complications. Since postoperative complications and long-term morbidity are common in children, special precautions should be taken with the preoperative assessment, planning, execution of surgery and postoperative care to achieve better results.

Molecular characterization of the bovine type II IL-1 receptor

The purpose of this study was to clone and characterize the bovine IL-1rII. Using a human IL-1rII probe, three putative exons of the bovine IL-1rII were identified from a bovine genomic library. The full length cDNA for bovine IL-1rII was cloned from a bovine endometrial cDNA library using oligonucleotides designed from those exons. The nucleotide sequence of the bovine IL-1rII cDNA has 79, 69 and 69% identity with those of human, mouse, and rat IL-1rII, respectively. The bovine IL-1rII cDNA contains an open reading frame encoding 400 amino acids with a predicted amino acid sequence of 71, 58, and 59% identity with those of human, mouse and rat IL-1rII, respectively. Transient transfection of COS cells with the cloned bovine IL-1rII cDNA resulted in specific binding of bovine IL-1 beta, with a Kd of 1.82 x 10(-10) M. At least two transcripts of bovine IL-1rII were identified from bovine peripheral blood mononuclear cells (PBMCs), liver, and fetal thymocytes by Northern blot analysis. The relative proportion of these transcripts varied with cell type. In addition, bovine IL-1rII transcripts were detected by RT-PCR in stimulated and unstimulated neutrophils, fibroblasts, and splenocytes. The results of this study provide the first characterization of bovine IL-1rII at a molecular level.

Rabbit DQ52 and DH gene expression in early B-cell development

Rabbits predominantly rearrange the most 3'VH gene (VH1); thus combinatorial diversity is very limited. In man and mouse, the most 3'DH gene, DQ52, is preferentially rearranged early in B-cell development. To test whether this preference for rearranging a DH gene segment based on 3' end proximity exists in rabbit, we cloned and sequenced the rabbit DQ52 gene. The 11 base pair coding region sequence is identical to a published mouse DQ52, and 81.8% similar to the human sequence. It is localized approximately 805 bp upstream of the JH1 gene. However, the 3' recombination signal sequence has an atypical nonamer. We prepared mRNA from 15- to 28-day fetal rabbits and amplified expressed VDJ sequences of mu mRNA by RT-PCR. The PCR products with VDJ rearrangements were cloned and sequenced. As expected, 44 of 45 VDJ sequences reflected use of the 3' VH1a2 gene, but the DQ52 gene was utilized very infrequently, if at all. We found only one VDJ sequence from 28-day fetal liver B-cells with 8 bp that matched the germline DQ52 sequence. Instead of expressing DQ52, another DH gene, Df was frequently expressed. We cloned the genomic Df gene and localized it about 32 kb upstream of the JH region. Thus, in contrast to man and mouse, rabbits preferentially express a DH gene located in the middle of the DH region early in B cell ontogeny. This may correlate with more frequent initial rearrangement of VH to DH in rabbit B cells.

The salvage of a degloved hand skin flap by arteriovenous shunting

Nine cases of hand degloving injuries were treated successfully with arteriovenous shunting technique. Of these nine cases, four were degloved from the wrist level and one from the forearm, three were degloved at the palm and one at the dorsum of the hand. All injuries resulted in distally based skin flaps, which were either superficial to the palmar fascia or within the subcutaneous layer. Lack of active bleeding from the periphery of the avulsed flaps substantiated circulatory compromise before revascularization. Survival of the avulsed flaps was achieved by directing the proximal arterial flow into the venous channel within the avulsed skin flaps. The post-operative care and rehabilitation were straightforward, and functional results were satisfactory.

Effect of ionizing radiation on in vivo striatal release of dopamine in the rat

The time-course effect of ionizing radiation on the levels of basal and KCl-stimulated striatal release of dopamine (DA) was examined in vivo using microdialysis techniques. The basal level of extracellular DA in sham-irradiated controls was 0.172 +/- 0.042 pmol/sample (n = 9), and it increased 7.1-fold after the stimulation by 30 mM KCl (20microliters). However, the release of dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA), two metabolites of DA, was reduced significantly by 30 mM KCl (P < 0.05). In the presence of 10 microM forskolin, an activator of adenylate cyclase, a second stimulation by 30 mM KCl increased the release of DA 6.9-fold. Radiation exposure, at a dose of 10 Gy at 10 Gy/min, had no significant effect on the levels of either basal or KCl-stimulated release of DA or on the release of DOPAC and HVA. Striatal DA release increased in response to two consecutive challenges of KCl. However, the release of DA in response to the second challenge of KCl was significantly smaller than that after the first challenge (543 +/- 110% compared to 794 +/- 164%, P < 0.05; Student's paired t test). Pretreatment with 10 muM forskolin, which by itself had no significant effect on the level of basal release of DA, prevented the decreased response of DA to the second challenge of KCl. Our results suggest that radiation exposure at the dose we used has no significant effect on the level of the basal release of DA or the release of DA stimulated by 30mM KCl in the rat striatum, and that a reduced release of DA in response to repeated KCl stimulation might involve the cAMP effector system.

Effect of chloral hydrate on in vivo KCl-induced striatal dopamine release in the rat

The release of striatal dopamine (DA) and its metabolites in response to locally-induced K+ depolarization was investigated in vivo in chloral hydrate-anesthetized and freely moving rats. KCl at concentrations of 30, 50, and 100 mM induced significant dose-dependent increases in extracellular DA overflow in both chloral hydrate-anesthetized and freely moving rats (P < 0.05). Extracellular levels of dihydroxyphenylacetic acid (DOPAC), homovanillic acid (HVA), and 5-hydroxyindoleacetic acid (5-HIAA) were decreased. The DA overflow in response to 30 mM KCl stimulation in anesthetized rats was significantly greater than that in freely moving rats (P < 0.05). In addition, chloral hydrate anesthesia resulted in a significant decrease in extracellular levels of DOPAC and significant increases in extracellular levels of HVA and 5-HIAA in comparison with freely moving rats (P < 0.05). Furthermore, the basal level of extracellular HVA in chloral hydrate-anesthetized rats was significantly higher than that in freely moving rats. These results suggest that chloral hydrate anesthesia could have significant effects on the pharmacological response of the striatal dopaminergic neurons.