Overexpression of GDNF induces and maintains hyperinnervation of muscle fibers and multiple end-plate formation

This study examined the role of glial cell line-derived neurotrophic factor (GDNF) in synaptic plasticity at the developing neuromuscular junction. Transgenic mice overexpressing GDNF in skeletal muscle under the myosin light chain-1 promoter were isolated. Northern blot and ELISA at 6 weeks of age indicated that GDNF mRNA and protein levels were elevated threefold in the lateral gastrocnemius muscle (LGM) of the GDNF-transgenic animals. Histochemical examination of LGM tissue sections at 6 weeks of age revealed a 70% increase in the number of cholinesterase-positive end plates without changes in end-plate area. Multiple end plates on a single muscle fiber were also observed, in addition to multiple axonal processes terminating on individual end plates. No change in the number of spinal motoneurons, overall LGM size, or muscle type composition was observed. Finally, overexpression of GDNF in muscle caused hypertrophy of neuronal somata in dorsal root ganglia without affecting their number. These findings demonstrate that overexpression of a single neurotrophic factor in skeletal muscle induces multiple end-plate formation and maintains hyperinnervation well beyond the normal developmental period. We suggest that GDNF, a muscle-derived motoneuron neurotrophic factor, serves an important role in the regulation of synaptic plasticity in the developing and adult neuromuscular junction.

Clinical value of lung uptake of iodine-123 metaiodobenzylguanidine (MIBG), a myocardial sympathetic nerve imaging agent, in patients with chronic heart failure

This study investigated the clinical value of I-123 MIBG pulmonary accumulation and washout in patients with chronic heart failure (CHF). Nineteen patients with CHF and 15 normal volunteers (NL) were included. The uptake ratio of heart to mediastinum (H/M), that of lung fields to mediastinum (L/M), and washout rate (WR) of the heart and lung fields were calculated in anterior planar images and compared with results of echocardiography and cardiac catheterization. In the CHF group, the lung uptake in delayed images increased and lung WR was decreased, suggesting pulmonary endothelial lesions. Furthermore, there was a negative correlation between right and left lung WR and pulmonary arterial diastolic pressure (PA(D)) and pulmonary arterial systolic pressure (PA(s)) in the CHF group. Since the WR of MIBG reflected PA, it may be used as an index of severity of cardiac dysfunction.

[Modification of transnasal medial canthopexy]

OBJECTIVE

To study the curative effect of transnasal medial canthopexy.

METHODS

By a coronal or medial canthal incision, we applied transnasal medial canthopexy to repair medial canthal detachment. A total of 78 patients received the operation.

RESULTS

Of them, 64 patients obtained satisfactory postoperative appearance with one operation; 6 patients obtained satisfactory results with two operations. The operation was unsuccessful in 8 patients.

CONCLUSION

This method is one of the ideal methods of repairing medial canthal detachment, however its indications should be observed.

CRTF is a novel transcription factor that regulates multiple stages of Dictyostelium development

During aggregation, Dictyostelium establish nanomolar oscillation waves of extracellular cAMP, but as development progresses, cells become responsive to higher, non-fluctuating concentrations of cAMP. The regulation of the promoter responsible for expression of cAMP receptor subtype 1, CAR1, during aggregation reflects these signaling variations. Transcription of CAR1 from the early, aggregation promoter is activated by cAMP pulsing, but is repressed by continuous exposure to micromolar concentrations of cAMP. Deletion and mutation analyses of this promoter had defined an element essential for cAMP-regulated expression, and mobility shift assay, DNA crosslinking and DNase I footprinting experiments had identified a nuclear protein (CRTF) with zinc-dependent sequence binding specificity. In our study, CRTF was purified to homogeneity, peptides were sequenced and full-length cDNAs were obtained. The deduced CRTF protein is ∼100 kDa with a C-terminal, zinc finger-like motif required for DNA binding; CRTF purified from cells, however, represents only a 40 kDa C-terminal fragment that retains DNA-binding activity.

As might have been predicted if CRTF were essential for the regulation of CAR1, crtf-null strains fail to develop under standard conditions or to exhibit induced expression of CAR1 or other cAMP-regulated genes. Furthermore, crtf-nulls also fail to sporulate, even under conditions that bypass the dependence on early cAMP signaling pathways. In addition, early developmental events of crtf-null strains could be rescued with exogenous cAMP treatment, constitutive expression of CAR1 or co-development with wild-type cells; however, these treatments were insufficient to promote sporulation. This suggests a cell-autonomous role for CRTF during late development that is separate from its capacity to control CAR1 expression. Finally, ablation of CRTF promotes a precocious induction of certain cAMP-dependent gene expression pathways. We suggest that CRTF may function to help insulate distinct pathways from simultaneous and universal activation by cAMP. CRTF, thus, exhibits multiple complex and independent regulatory functions during Dictyostelium development.

Efficient third-harmonic generation in partly periodically poled KTiOPO(4) crystal

A partly periodically poled KTiOPO(4) (KTP) crystal has been designed to integrate quasi-phase-matched second-harmonic generation (QPM SHG) with sum-frequency generation in one crystal for generating a third-harmonic beam. The highest conversion efficiencies of 45% and 3% have been achieved in our experiments for QPM SHG and third-harmonic generation, respectively, by use of picosecond laser pulses at 1.327 microm . We have also discovered that periodically poled KTP has slightly different indices (n(z)) from bulk KTP.

Tumor suppression and therapy sensitization of localized and metastatic breast cancer by adenovirus p53

We have examined the effects of a replication-defective adenovirus encoding p53 (RPR/INGN 201 [Ad5CMV-p53]; Adp53), alone or in combination with the breast cancer therapeutic doxorubicin (Adriamycin), to suppress growth and induce apoptosis in breast cancer cells in vitro. We have also examined the in vivo effect of intratumoral administration of Adp53, alone or in combination with doxorubicin, to suppress the growth of established subcutaneous MDA-MB-435 breast cancer tumors. Finally, using the MDA-MB-435 orthotopic model of metastatic breast cancer, we have examined the effect of systemic administration of Adp53, alone or in combination with doxorubicin, to reduce the incidence of metastases. We find that whereas in vitro treatment of cells with Adp53 reduces [(3)H]thymidine incorporation by about 90% at 48 hr, cell viability at 6 days is reduced by only some 50% relative to controls. Although apoptosis is detectable in Adp53-treated cultures, these results suggest that a large fraction of Adp53-treated cells merely undergo reversible cell cycle arrest. Combined treatment with Adp53 and doxorubicin results in a greater than additive loss of viability in vitro and increased apoptosis. In vivo, locally administered Adp53 suppresses growth of established subcutaneous tumors in nude mice and suppression is enhanced by doxorubicin. In the metastatic breast cancer model, systemic administration of Adp53 plus doxorubicin leads to a significant reduction in the incidence of metastases relative to Adp53 or doxorubicin alone. Taken together, these data indicate an additive to synergistic effect of Adp53 and doxorubicin for the treatment of primary and metastatic breast cancer.

Embryotoxicity of the alkylphenol degradation product 4-nonylphenol to the crustacean Daphnia magna

Laboratory studies have suggested that some alkylphenols and pesticides elicit developmental toxicity to crustaceans. The purpose of the present study was to evaluate the possibility that the alkylphenol degradation product 4-nonylphenol is embryotoxic to the crustacean Daphnia magna through its known ability to interfere with the metabolic elimination of testosterone. Direct exposure of maternal daphnids to testosterone caused developmental abnormalities in neonates that consisted of partial arrest of early embryonic development and abnormalities in shell spine and first antennae development. Exposure of maternal daphnids to concentrations of 4-nonylphenol also produced developmental abnormalities though the profile of abnormalities was distinct from that observed throughout the testosterone concentration-response curve. Thus, 4-nonylphenol is a developmental toxicant in daphnids, but its toxicity is not consistent with that elicited by elevated testosterone accumulation. Further experiments demonstrated that testosterone was directly toxic to developing embryos, and the maternal organism can serve as the vector for this toxicity. In contrast, neither direct embryo exposure nor early maternal exposure to 4-nonylphenol elicited embryotoxicity consistent with that observed during continuous maternal and gestational exposure. Thus, 4-nonylphenol is not directly embryotoxic at these exposure levels, but rather toxicity is mediated by maternal influences during gestation. The threshold concentration for the occurrence of developmental abnormalities ( approximately 44 microg/L) indicates that typical environmental concentrations of 4-nonylphenol pose no imminent hazard with respect to developmental toxicity. However, these effects do occur at sufficiently low levels to warrant evaluation of the relative susceptibility of other crustacean species to this previously uncharacterized mode of toxicity.

[Perioperative changes of plasma ET-1 in patients undergoing coronary artery bypass grafting and the effect of nitroglycerin]

OBJECTIVE

To observe the dynamic changes of the plasma ET-1 and the effect of low dose nitroglycerin in patients with coronary artery bypass surgery.

METHODS

40 patients with coronary artery bypass surgery were divided into group A and B. Group B received intravenous nitroglycerin 1 microg x kg(-1) x min(-1) perioperatively. We used RIA to assay the plasma ET-1 level. All the hemodynamic parameters were recorded by the Swan-Ganz catheter.

RESULTS

The preoperative plasma ET-1 level in patients with coronary artery disease was significantly higher than the normal level. Five minutes after cardiopulmonary bypass in these patients the plasma ET-1 level was increased significantly until 6 to 8 hours after operation. The increased plasma ET-1 level in group B was less than in group A. There was a positive correlation between the plasma ET-1 level and the mean pulmonary pressure in group A 2 and 8 hours after operation.

CONCLUSION

In patients undergoing coronary artery bypass surgery, the increased plasma ET-1 level may be partly due to the influence of cardiopulmonary bypass. Low dose of nitroglycerin is beneficial to these patients.

Riluzole and methylprednisolone combined treatment improves functional recovery in traumatic spinal cord injury

The potential use of riluzole (a glutamate release inhibitor) alone or in combination with methyl-prednisolone (MP) in treating acute spinal cored injury (SCI) was examined. Rats received a contusion injury to the spinal cord using the NYU impactor and were treated with vehicle, riluzole (8 mg/kg), MP(30 mg/kg), or riluzole + MP at 2 and 4 h following injury. Animals continued to receive riluzole treatment (8 mg/kg) for a period of 1 week. The animals were then tested weekly for functional recovery using the BBB open field locomotor score. At the end of testing (6 weeks after injury), each spinal cord was examined for the amount of remaining tissue at the injury site and a myelination index was used to quantify remaining axons in the ventromedial white matter. In this study, only the combination treatment was found to significantly improve behavioral recovery as assessed using the BBB open field locomotor scale. In addition, the combination treatment promoted tissue sparing at the lesion epicenter, but had no clear effect on the index of myelination. The results of this study clearly demonstrate the potential beneficial effects of a combination approach in the treatment of traumatic SCI.

Riluzole increases high-affinity glutamate uptake in rat spinal cord synaptosomes

The purpose of this study was to examine the effect of the anti-convulsant agent, riluzole, on high-affinity glutamate uptake as measured in rat spinal cord synaptosomes. The rate of glutamate uptake was significantly increased in the presence of 0.1 microM and 1.0 microM riluzole, but not at the higher concentrations examined. Kinetics analysis demonstrated that riluzole (0.1 microM) decreased the apparent K(m) by 21% and increased the V(max) by 31%. Glutamate uptake also was significantly increased in spinal cord synaptosomes obtained from rats treated with 8 mg/kg (i.p.) of riluzole and sacrificed 4 h later. The increase in glutamate uptake in vitro was not affected by pretreatment either with H7, an inhibitor of PKA and PKC, or with the PKC activating phorbol ester, 12-O-tetradecanoylphorbol 13-acetate. Previous studies have shown that some of the actions of riluzole are mediated by G proteins sensitive to pertussis toxin. Surprisingly, treatment of synaptosomes with pertussis toxin alone increased the rate of glutamate uptake, while having no effect on uptake in the presence of riluzole. However, pretreatment with cholera toxin was found to completely block the effects of riluzole on glutamate uptake. These results reveal an additional mechanism by which riluzole can affect glutamatergic neurotransmission, and provides further support that riluzole may prove beneficial in the treatment of traumatic central nervous system injuries involving the excitotoxic actions of glutamate.

Riluzole improves measures of oxidative stress following traumatic spinal cord injury

Rats received a contusion injury to the spinal cord followed by treatment with riluzole (a glutamate release inhibitor, 8 mg/kg), methylprednisolone (MP 30 mg/kg) or both. At 4 h following injury, spinal cords were removed and synaptosomes prepared and examined using five measures of oxidative stress. Riluzole treatment was found to improve mitochondrial function, and enhance glutamate and glucose uptake. As expected, MP treatment was found to reduce lipid peroxidation, but also improved glutamate and glucose uptake. Interestingly, the combination treatment was found to be effective in improving all five measures of oxidative stress. The results of this study clearly demonstrate the potential beneficial effects of a combination approach in the treatment of oxidative stress events in traumatic spinal cord injury.

Investigation of damage mechanisms of KTiOPO4 crystals by use of a continuous-wave argon laser

We have developed a simple method that uses cw irradiation from an argon laser to measure the damage threshold of KTP crystals. Our experimental results show that there are two types of damage in KTP crystal, depending on the polarization of the incident laser beam. One type of optical damage is the appearance of gray tracks, including both dark tracks and orange dots, when the pump polarization is perpendicular to the z axis. The other type is invisible damage when the polarization is parallel to the z axis. In addition, we have also observed weak photorefractive two-wave mixing in KTP crystals in each of these polarization states. After a systematic analysis we have concluded that the first type of damage is due to the formation and absorption of Ti3+ and Fe3+ centers and the second is due to the drift of K+ ions. The weak photorefractive effect is the result of screening of the electric field by the drifted K+ ions.

FGFR3 gene mutation (Gly380Arg) with achondroplasia and i(21q) Down syndrome: phenotype-genotype correlation

We report the case of a boy with achondroplasia and i(21q) Down syndrome. Besides craniofacial features typical in Down syndrome, the skeletal findings of achondroplasia dominate the clinical picture. The diagnosis of Down syndrome was based on clinical features and the cytogenetic finding of i(21q) trisomy 21. The diagnosis of achondroplasia was based on the presence of clinical and radiographic findings and confirmed by the presence of a common FGFR3 gene mutation (Gly380Arg) detected by restriction enzyme analysis and sequencing of the polymerase chain reaction products. This is the first report of achondroplasia associated with i(21q) Down syndrome.

[One-stage correction of the contracted eye socket and orbitozygomatic hypoplasia]

OBJECTIVE

In order to simultaneous correct the contracted eye socket and orbitozygomatic hypoplasia that caused by early ophthalmectomy and radiotherapy.

METHODS

The one-stage surgical procedure for eye socket reconstruction and bone graft coverage included rotation of a postauricular skin flap and a temporal fascial flap. Hydroxyapatite implant was inserted as an onlay bone graft substitute to enlarge the orbitozygomatic region.

RESULTS

In 16 cases using this method, the results were satisfactory and encouraging with minor complications.

CONCLUSION

This procedure is effective for radiated complex deformities in paraorbit and eye socket.

Third-harmonic generation by cascading second-order nonlinear processes in a cerium-doped KTiOPO4 crystal

We have achieved effective third-harmonic generation (THG) by cascading second-harmonic and sum-frequency generation in a single cerium-doped KTiOPO (4) crystal by using femtosecond laser pulses at 1.32 microm. A conversion efficiency of 0.17% was achieved with an average pump power of 35 mW.Furthermore, a unique quadratic power dependence for this type of THG was confirmed. We developed a theory and obtained an analytical solution for the THG.The solution exactly describes the measured characteristics of the THG.

[A case-control study on the risk factors in naevus fusco-caeruleus zygomaticus]

OBJECTIVE

To determine the risk factors of naevus fusco-caeruleus zygomaticus, a case-control study was conducted in 100 cases.

METHODS

The selection of major risk factors was through logistic regression and chi 2-test.

RESULTS

It was suggested that the high exposed rate in the family history of objectives was related to "genetic susceptibility". Histories of using cosmetics and exposure to ultraviolet ray were identified as environmental risk factors. However, there was no single factor that could completely explain the etiology of naevus fusco-caeruleus zygomaticus.

CONCLUSION

We believe that coordinating effects of both susceptibility in genetics and environmental risk factors may play important roles in the pathogenesis of naevus fusco-caeruleus zygomaticus. Thus combined research on the location of gene mutation with environmental factors is important in the discovery of the etiology of naevus fusco-caeruleus zygomaticus.

[The design and implement of PACS components in digital imaging apparatus]

The domestic application of PACS will surely be developed in the future, but it will still take a few years. This paper proposes a tradeoff scheme: Attaching to digital imaging apparatus the PACS components, which mainly contain the Auto-archiving unit, the Communication unit supporting WAN as well as LAN and the Converting Interface unit to the hospital PACS. In this way, a single digital imaging apparatus can archive and transmit data independently, also can merge with the hospital PACS conveniently in the future. In this paper, both the design and the implement are discussed in detail.

Surgical reconstruction of the contracted eye socket and orbitozygomatic hypoplasia in a one-stage operation

To correct the contracted eye socket and orbitozygomatic hypoplasia simultaneously secondary to previous surgery and radiotherapy, we employed a one-stage surgical reconstruction that used a postauricular skin flap and temporal fascial flap, which were rotated for eye socket reconstruction and bone graft coverage. Hydroxyapatite was inserted as an onlay bone graft substitute to enlarge the orbitozygomatic region. In our 12-case experience the results were satisfying and encouraging with minor complications, which are presented.

Uniparental isodisomy resulting from 46,XX,i(1p),i(1q) in a woman with short stature, ptosis, micro/retrognathia, myopathy, deafness, and sterility

We report on a 43-year-old woman who was referred for evaluation because of minor facial anomalies, myopathy, sterility, short stature, hearing loss, downward slant of palpebral fissures, bilateral ptosis, severe micro/retrognathia, high arched palate, and scoliosis. Cytogenetic analyses utilizing GTG/CBG bandings showed presence of one i(1p) and one i(1q) without normal chromosome 1 homologues. Fluorescence in situ hybridization analysis showed hybridization to only two chromosomes, consistent with the G-banded interpretation of i(1p) and i(1q). To the best of our knowledge, this is the first case of isochromosomes 1p and 1q replacing the two normal chromosome 1s. Molecular investigations using markers for chromosome 1 showed inheritance of only one set of paternal alleles and absence of any maternal alleles in the patient. The adverse phenotype of the patient may be due to one or more recessive mutations, genomic imprinting, or a combination of both.

Correction of the contracted eye socket and orbitozygomatic hypoplasia using postauricular skin flap and temporal fascial flap

The authors corrected a contracted eye socket and orbitozygomatic hypoplasia simultaneously, secondary to previous surgery and radiotherapy. A one-stage surgical reconstruction was undertaken using both a postauricular skin flap and a temporal fascial flap, which were rotated for eye socket reconstruction and bone graft coverage. Hydroxyapatite was inserted as an onlay bone graft substitute to enlarge the orbitozygomatic region. The authors' experience with 12 patients resulted in contours that were satisfying and encouraging. f1

[The implement of remote medical treatment by Internet & RAS]

This paper introduces a new method by taking full advantage of Internet and RAS technology, which can implement remote medical treatment perfectly. This method has been proved to be practical and will facilitate chinese hospital digital and information construction. The features and the advantages of of both technologies are introduced. Their designs & implement, and the prospect of this proposed method in china are discussed in details.

Sequence-specific protein interaction with a transcriptional enhancer involved in the autoregulated expression of cAMP receptor 1 in Dictyostelium

Major stages of Dictyostelium development are regulated by secreted, extracellular cAMP through activation of a serpentine receptor family. During early development, oscillations of extracellular cAMP mobilize cells for aggregation; later, continuous exposure to higher extracellular cAMP concentrations downregulates early gene expression and promotes cytodifferentiation and cell-specific gene expression. The cAMP receptor 1 gene CAR1 has two promoters that are differentially responsive to these extracellular cAMP stimuli. The early CAR1 promoter is induced by nM pulses of cAMP, which in turn are generated by CAR1-dependent activation of adenylyl cyclase (AC). Higher, non-fluctuating concentrations of cAMP will adapt this AC stimulus-response, repress the activated early promoter and induce the dormant late promoter. We now identify a critical element of the pulse-induced CAR1 promoter and a nuclear factor with sequence-specific interaction. Mutation of four nucleotides within the element prevents both in vitro protein binding and in vivo expression of an otherwise fully active early CAR1 promoter and multimerization of the wild-type, but not mutant, sequence will confer cAMP regulation to a quiescent heterologous promoter. These cis and trans elements, thus, constitute a part of the molecular response to the cAMP transmembrane signal cascade that regulates early development of Dictyostelium.

Localization of glial cell line-derived neurotrophic factor receptor alpha and c-ret mRNA in rat central nervous system

Glial cell line-derived neurotrophic factor (GDNF) is a neurotrophic factor that influences the survival and function of several neuronal populations in the central (CNS) and peripheral nervous systems. The actions of GDNF are mediated by a multicomponent receptor complex composed of the tyrosine kinase product of c-ret and the ligand-binding protein GDNF receptor alpha (GDNFR-alpha). In the present study, we used in situ hybridization to localize cells expressing the mRNA for these GDNF receptor subunits in rat CNS. As reported previously, GDNFR-alpha and c-ret mRNA are present in the substantia nigra and ventral tegmental area, regions containing GDNF-responsive dopamine neurons. However, both mRNA were found in motor neurons of spinal cord and brainstem nuclei that innervate skeletal muscle. These areas include alpha motor neurons in the ventral horn of spinal cord and neurons in hypoglossal, facial, trigeminal, and abducens nuclei. In areas rostral to the substantia nigra, c-ret mRNA is not detected, whereas GDNFR-alpha is found in numerous brain structures, including the hippocampus, cortex, medial geniculate, and the medial habenula, the latter area expressing the highest levels of GDNFR-alpha mRNA in brain. These results provide evidence that c-ret and GDNFR-alpha mRNA are expressed in neuronal populations involved in motor function and provides further support for GDNF as a target-derived neurotrophic for these motor neurons. The observation that GDNFR-alpha mRNA is localized in several brain structures that do not contain detectable levels of c-ret mRNA indicates that either GDNFR-alpha utilizes signal transduction molecules other than c-ret in these areas or that other GDNF-like ligands that utilize GDNFR-alpha as a receptor may be present.

[Reliability design and analysis of man-machine performance of display and illumination system in cockpit]

This paper analysed and discussed the basic reliability of display and illumination system in which Chinese characters displayed on LCD were read and the colours were identified, and instruments in different visual views and the instruments of differential display models were read. The colour rendering of the light source was also evaluated. Basic reliability may be chosen as 0.9995.