Thermodynamics of electron transfer in oxygenic photosynthetic reaction centers: a pulsed photoacoustic study of electron transfer in photosystem I reveals a similarity to bacterial reaction centers in both volume change and entropy

The thermodynamic properties of electron transfer in biological systems are far less known in comparison with that of their kinetics. In this paper the enthalpy and entropy of electron transfer in the purified photosystem I trimer complexes from Synechocystis sp. PCC 6803 have been studied, using pulsed time-resolved photoacoustics on the 1 micros time scale. The volume contraction of reaction centers of photosystem I, which results directly from the light-induced charge separation forming P(700+F(A)/F(B-) from the excited-state P700*, is determined to be -26 +/- 2 A3. The enthalpy of the above electron-transfer reaction is found to be -0.39 +/- 0.1 eV. Photoacoustic estimation of the quantum yield of photochemistry in the purified photosystem I trimer complex showed it to be close to unity. Taking the free energy of the above reaction as the difference of their redox potentials in situ allows us to calculate an apparent entropy change (TDeltaS) of +0.35 +/- 0.1 eV. These values of DeltaV and TDeltaS are similar to those of bacterial reaction centers. The unexpected sign of entropy of electron transfer is tentatively assigned, as in the bacterial case, to the escape of counterions from the surface of the particles. The apparent entropy change of electron transfer in biological system is significant and cannot be neglected.

Polyamines: new cues in cellular signal transduction

The naturally occurring polyamines putrescine, spermidine, and spermine are involved in signal transduction. This has been demonstrated by using inhibitors for polyamine biosynthesis (such as alpha-difluoromethylornithine) or adding polyamines to cultured cells. Different polyamines, preferentially activated protein kinases (tyrosine kinases and MAP kinases), stimulated the expression of nuclear protooncogenes (myc, jun, and fos).

Estrogen receptor alpha gene polymorphism in schizophrenia: frequency, age at onset, symptomatology and prognosis

Schizophrenic disorders are equally distributed for both sexes; however, later onset, milder psychopathology and better outcome are associated with the female gender. This sex difference is thought to be partly due to the estrogen system. Recent studies have determined that estrogen receptor alpha subtype (ER alpha) genetic polymorphisms may affect the expression of ER alpha, and are associated with Alzheimer's disease. For this study, we investigated the association of ER alpha polymorphisms for 125 schizophrenic patients and 142 control subjects. No significant differences for genotype distribution or allele frequency were revealed comparing controls and schizophrenic patients. The ER alpha genotypes were not associated with onset age, psychiatric symptoms or outcome for schizophrenic cases. With new research highlighting the prominent role of sex hormones in neurological and psychological dysfunction, further study is needed to explore the genetic effect of the sex hormone receptor gene on susceptibility mental disorders and associations with different phenotypes.

Endoscope-assisted microsurgery for treatment of a suprasellar craniopharyngioma presenting precocious puberty

Being the most common childhood tumor to involve the hypothalamus and pituitary gland, craniopharyngioma, a histologically benign tumor, is usually related to growth retardation and hypogonadism. The presentation of precocious puberty is very rare for a hypothalamic craniopharyngioma. Here, we report such a case. The female patient had presented with symptoms of menarche and breast development since she was 6 years old. Hormonal therapy with a gonadotropin-releasing hormone analogue was instituted to cease precocious puberty but was unsuccessful. Magnetic resonance imaging of the sella showed a 1-cm tumor in the hypothalamic area. Through a pterional approach, the tumor was removed en bloc with endoscope-assisted microsurgery. After the operation, our patient's symptoms improved, so the hormone therapy was discontinued. This extremely unique association of craniopharyngioma and precocious puberty, the causes and mechanisms involved along with the advantages of endoscope-assisted microsurgery are discussed.

Association analysis of polymorphism in the promoter region of the alpha2a-adrenoceptor gene with schizophrenia and clozapine response

There exists considerable evidence implicating the alpha (alpha) adrenergic system in the superior therapeutic effects of clozapine for the treatment of schizophrenia, as also its associated adverse hypersalivation side effect. It would seem plausible for variants of the adrenoceptors to be associated with the clozapine response. The present study tested the hypothesis that a biallelic polymorphism in the promoter region of the alpha2a-adrenoceptor gene confers susceptibility to schizophrenia, and is associated with a clozapine-induced (favorable) therapeutic response and/or a clozapine-induced hypersalivation. Ninety-seven treatment-resistant schizophrenic patients were assessed using the Brief Psychiatric Rating Scale before and after clozapine treatment. The results of clozapine treatment demonstrated that the alpha2a-adrenoceptor gene variants did not play a major role in the susceptibility, hypersalivation adverse effect or clozapine response of patients with schizophrenia. The polymorphism of the alpha2a-adrenoceptor gene investigated is not likely to play a major role in the pathogenesis of schizophrenic disorders or clozapine response, although the hypothesis that these genes are implicated in the cognitive deficit and polydipsia associated with schizophrenic disorders may, however, still warrant further study.

Association between tryptophan hydroxylase gene polymorphism (A218C) and schizophrenic disorders

The human tryptophan hydroxylase (TPH) gene, the rate-limiting enzyme in serotonin biosynthesis, was localized on human chromosome 11p14-p15.3. Variation within intron 7 of the TPH gene was found to influence serotonin metabolism in the brain. To explore the possible role of TPH in the pathogenesis of schizophrenic disorders, we genotyped the TPH A218C polymorphism in 196 schizophrenic patients and 251 controls. The results demonstrated that genotype distribution was significantly different between schizophrenic patients and control subjects (P=0.002). No association was found between TPH genotypes and suicidal history in schizophrenic patients (P=0.239). The positive finding in this study suggests that the TPH 218A allele is a risk factor for schizophrenic disorders or is in linkage disequilibrium with the putative schizophrenia susceptibility locus in Han Chinese population.

Extreme damping in composite materials with negative-stiffness inclusions

When a force deforms an elastic object, practical experience suggests that the resulting displacement will be in the same direction as the force. This property is known as positive stiffness. Less familiar is the concept of negative stiffness, where the deforming force and the resulting displacement are in opposite directions. (Negative stiffness is distinct from negative Poisson's ratio, which refers to the occurrence of lateral expansion upon stretching an object.) Negative stiffness can occur, for example, when the deforming object has stored (or is supplied with) energy. This property is usually unstable, but it has been shown theoretically that inclusions of negative stiffness can be stabilized within a positive-stiffness matrix. Here we describe the experimental realization of this composite approach by embedding negative-stiffness inclusions of ferroelastic vanadium dioxide in a pure tin matrix. The resulting composites exhibit extreme mechanical damping and large anomalies in stiffness, as a consequence of the high local strains that result from the inclusions deforming more than the composite as a whole. Moreover, for certain temperature ranges, the negative-stiffness inclusions are more effective than diamond inclusions for increasing the overall composite stiffness. We expect that such composites could be useful as high damping materials, as stiff structural elements or for actuator-type applications.

Loss of p16 and/or pRb protein expression in NSCLC. An immunohistochemical and prognostic study

The disruption of p16/pRb pathway has been reported in several types of human cancer including lung cancer. However, the etiological and prognostic involvement of this pathway remains poorly defined in lung tumorigenesis in Taiwan. Therefore, we investigated the expressions of p16 and pRb in 107 non-small cell lung cancer (NSCLC) patients by immunohistochemical analysis. The associations of altered p16 and pRb expressions with prognosis were also examined. Sixty-four specimens (59.8%) exhibited alteration of p16 and/or pRb expression, with 49.5 and 22.4% of the tumors failing to express p16 and pRb, respectively. However, there was no reciprocally correlated expression of p16 and pRb. Negative p16 and pRb expression did not correlate well with patients' clinicopathological parameters such as age, sex, smoking habit, tumor type, and tumor stage. In addition, negative p16 and pRb expression was not statistically associated with poor prognosis (P=0.10 and P=0.74, respectively). Our results suggested that the disruption of the p16/pRb pathway plays a significant role in NSCLC tumorigenesis whereas it may not have significant importance in the prognostic evaluation of NSCLC in Taiwan.

Cerebral intraventricular hemorrhage caused by a large cerebral arteriovenous malformation at 31 years after diagnosis

Cerebral arteriovenous malformation (AVM) has an overall 2% to 4% annual risk of hemorrhage. The annual risk of hemorrhage does not decrease with age. However, the natural history of non-operative AVM is difficult to follow up consistently for more than 30 years. In this report, we present a case with a large cerebral AVM which developed a major bleeding causing intraventricular hemorrhage (IVH) 31 years after the diagnosis. A male patient was proved to have a cerebral AVM in the right corpus callosum by cerebral angiography at ages 20 and 28. He was found losing consciousness due to rupture of AVM with IVH at age 51. A small cerebral aneurysm and a dilated vein (aneurysm) of Galen were noted also. A craniotomy with removal of the hematoma and microsurgical resection of the AVM was performed immediately, and the patient regained normal respiration and consciousness about 2 months and 7 months after craniotomy, respectively. We recommend that neurosurgeons should play active roles in encouraging young patients with large AVMs to receive microsurgical resection.

Allelic variants of the alpha1a adrenoceptor and the promoter region of the alpha2a adrenoceptor and temperament factors

Human personality traits are partially determined by genes. It has been suggested that the reward-dependence dimension assessed by the Tridimensional Personality Questionnaire (TPQ) is related to the central noradrenergic system. Our population-based association study tested the hypothesis that genetic variants of the adrenoceptor are associated with this personality trait. The alpha1a- and the alpha2a-adrenoceptor genotypes were determined for 198 healthy Han Chinese who had completed the TPQ. We found no significant differences for TPQ personality-factor scores, including reward dependence and its subscales, for subjects showing different adrenoceptor genotypes. Our negative findings suggest that polymorphisms of the alpha1a adrenoceptor and of the promoter region of the alpha2a-adrenoceptor have no major effect on the reward-dependence personality trait as assessed by TPQ.

[Efficacy of ablendazole emulsion in treatment of 212 patients with cystic echinococcosis]

OBJECTIVE

To verify the efficacy of abendazole emulsion, a new formulation of abendazole, in treatment of human cystic echinococcosis.

METHODS

212 patients with liver cystic echinococcosis were treated orally with albendazole emulsion at a daily dose of 10 mg/kg or 12.5 mg/kg for 3 to 12 months or over one year. The therapeutic efficacy was mainly evaluated by image feature examined with B ultrasound examination, a short-term efficacy at the completion of treatment and a long-term efficacy followed-up for 1-4 years.

RESULTS

In 212 patients treated with albendazole emulsion at a daily dose of 10 mg/kg and 12.5 mg/kg, the average cure rate, improved rate and the rate of no avail were 74.5%, 99.1% and 0.9% respectively after termination of the treatment, and the average long-term rates were 83.1%, 89.3% and 0.6% respectively. Recurrence occurred in 18 patients(10.2%). The results indicated that the best efficacy was seen in patients treated with albendazole 12.5 mg/kg daily for 9 months. Better response was also found when the recurrent patients were re-treated with albendazole.

CONCLUSION

The efficacy of albendazole emulsion on patients with liver cystic echinococcosis is much better than that of albendazole tablet or capsule and mebendazole. Meanwhile, the efficacy of albendazole emulsion is stable with less adverse effects. The results suggest that albendazole emulsion could be the drug of choice for treatment of cystic hydatid disease.

Association analysis of a functional catechol-o-methyltransferase gene polymorphism in schizophrenic patients in Taiwan

The catechol-O-methyltransferase (COMT) gene was thought to be a candidate gene for schizophrenia because of its role in inactivating dopamine. This study examined the relationship between a functional polymorphism (val158met) of the COMT gene, schizophrenia and its associated behaviors. One hundred and ninety-eight Chinese schizophrenic patients and 188 controls were genotyped by polymerase chain reaction restriction fragment length polymorphism. Of the schizophrenic patients, 72 had a history of violence and 62 had a history of suicide attempts. The results failed to show significant association between val158met polymorphism and schizophrenia, violence or suicide. However, our results showed a significant difference in age at disease onset among different genotypes (F = 5.501, p = 0.005).

No association between tryptophan hydroxylase gene polymorphism and Alzheimer's disease

Serotonergic dysfunction is implicated in Alzheimer's disease (AD) on the basis of studies of serotonin and its metabolite in postmortem specimens and CSF. There were also reports on association of a tryptophan hydroxylase (TPH) intron 7 variant and CSF 5-hydroxyindoleacetic acid concentrations. These suggested TPH might be a candidate to study for possible involvement in AD. Using a case-control association approach, we studied the TPH polymorphism in 150 subjects with AD and 100 controls. There were no significant differences in genotype or allele frequencies between controls and AD patients. The negative findings suggested that this TPH polymorphism has no major effect on the development of AD. However, the genetic variation of the TPH gene related to the symptomatology of AD deserves further investigation.

Two-chain high molecular weight kininogen induces endothelial cell apoptosis and inhibits angiogenesis: partial activity within domain 5

We previously reported that the binding of two-chain high molecular weight kininogen (HKa) to endothelial cells may occur through interactions with endothelial urokinase receptors. Since the binding of urokinase to urokinase receptors activates signaling responses and may stimulate mitogenesis, we assessed the effect of HKa binding on endothelial cell proliferation. Unexpectedly, HKa inhibited proliferation in response to several growth factors, with 50% inhibition caused by approximately 10 nM HKa. This activity was Zn(2+) dependent and not shared by either single-chain high molecular weight kininogen (HK) or low molecular weight kininogen. HKa selectively inhibited the proliferation of human umbilical vein and dermal microvascular endothelial cells, but did not affect that of umbilical vein or human aortic smooth muscle cells, trophoblasts, fibroblasts, or carcinoma cells. Inhibition of endothelial proliferation by HKa was associated with endothelial cell apoptosis and unaffected by antibodies that block the binding of HK or HKa to any of their known endothelial receptors. Recombinant HK domain 5 displayed activity similar to that of HKa. In vivo, HKa inhibited neovascularization of subcutaneously implanted Matrigel plugs, as well as rat corneal angiogenesis. These results demonstrate that HKa is a novel inhibitor of angiogenesis, whose activity is dependent on the unique conformation of the two-chain molecule.

Rapid diagnosis and quantification of herpes simplex virus with a green fluorescent protein reporter system

A genetically modified cell line (Vero-ICP10-EGFP) was constructed for detection of herpes simplex virus (HSV) by a simple, rapid and direct method. The cell line was developed by stable transfection of Vero cell with a plasmid encoding the green fluorescent protein (GFP) driven by the promoter of the HSV-2 ICP10 gene. As early as 6 h after infection with HSV, fluorescence-emitting cells can be observed under a fluorescence microscope. A single infected cell emitting fluorescence can be observed with soft agar overlay by inverted fluorescence microscopy. No induction of detectable fluorescence was seen following infections with human cytomegalovirus (HCMV), varicella zoster virus (VZV), coxsackievirus A16 and enterovirus 71. Analysis by flow cytometry also demonstrated that intensity of the triggered fluorescence is proportional to the titer of HSV inoculated. Taken together, this novel GFP reporter system could become a useful means for rapid detection and quantification of HSV in clinical specimens.

Competition with TATA box-binding protein for binding to the TATA box implicated in human cytomegalovirus IE2-mediated transcriptional repression of cellular promoters

The human cytomegalovirus IE2 is a sequence-specific DNA-binding protein. A consensus IE2-binding site (IBS) contains two copies of the dinucleotide CG separated by 10 not well-conserved but AT-rich nucleotides. In this report, we demonstrated that the TATA box of the insulin-like growth factor binding protein 4 (IGFBP4) promoter is embedded in an IBS. In a transient transfection study, IE2-mediated repression of a reporter driven either by a synthetic promoter containing the IGFBP4 TATA/IBS element or by the native IGFBP4 promoter was dependent on the intactness of the IBS. Competition with TBP for binding to the IGFBP4 TATA/IBS element may underlie the mechanism for the IE2-mediated repression, because IE2 and TATA box-binding protein (TBP) binding to the IGFBP4 TATA/IBS element are mutually elusive. Moreover, the TATA boxes of several other genes, including ADA and CPH-70, are likewise confined in IBS-like sequences. The IE2 interacts with those TATA/IBS elements in vitro and inhibits transcription driven by them in vivo, supporting the idea that competitive inhibition of TBP binding to the TATA box represents a novel mechanism exploited by IE2 to repress cellular gene expression.

Self-organized oscillations of strongly coupled dust coulomb clusters in plasma traps

The self-organized oscillation of a strongly coupled dust Coulomb cluster with an elongated cross section in a weakly ionized rectangular plasma trap is investigated. Through an inverse supercritical bifurcation at the low rf power end, a low-frequency (about 5 Hz) limit cycle oscillation of the whole cluster associated with the intracluster compressional lattice wave and phase-locked oscillation of the glow intensity distribution is observed. It is caused by the interplay of the dust motion and the shrinking and expanding of the confining dark space.

No evidence for association of alpha 1a adrenoceptor gene polymorphism and clozapine-induced urinary incontinence

Clozapine is an effective atypical antipsychotic that has high affinity for many neurotransmitter receptors. Among the adverse effects of clozapine, urinary incontinence is commonly found and is suggested to be caused by alpha-adrenergic blockade. We tested the hypothesis that clozapine-induced urinary incontinence is related to a genetic variant of the alpha(1a)-adrenoceptor. We also tested whether the alpha(1a)-receptor gene confers susceptibility to schizophrenic disorders. Our result indicated that the alpha(1a)-adrenoceptor gene polymorphism investigated plays no major role in the pathogenesis of schizophrenia or in clozapine-induced urinary incontinence. Considering the superior effects of clozapine and its potent adrenergic antagonistic effects, it is of interest to investigate the association between this polymorphism and the treatment response.

Association study of a cannabinoid receptor gene (CNR1) polymorphism and schizophrenia

Cannabis can induce schizophrenic-like symptoms in healthy individuals. A principal active ingredient of cannabis, delta-9-tetrahydrocannabinol, acts in the brain on a specific receptor, termed the cannabinoid receptor 1 (CNR1). The human gene for CNR1 is mapped to chromosome 6q14-15, and linkage studies have produced evidence for a schizophrenia-susceptibility locus in this region. To explore a possible role for CNR1 in the pathogenesis of schizophrenic disorders, we used an association study to genotype the CNR1 polymorphism for 127 schizophrenic patients and 146 control subjects. The results demonstrate no association between CNR1 genotypes and schizophrenic disorders (P = 0.409), with these negative findings suggesting that, for Chinese populations, the (AAT)n triplet repeat in the promoter region of the CNR1 gene is not directly involved in the pathogenesis of schizophrenic disorders.

[Studies of beef performance traits in Piemontese x Nanyang crossbred using microsatellites as genetic markers]

Five microsatellites, IDVGA-2, IDVGA-27, IDVGA-46, IDVGA-55 and TGLA-44 were associated to beef performance traits of 100 heads of Nanyang cattle, Piemontese and their hybrid cattle using general linear model (GLM) with statistical analysis system (SAS). For microsatellite IDVGA-27, allele 136 had a positive relation with heart girth, height at hip cross and chest depth (body measurements) and loin width (muscularity evaluation); however, allele 142 showed a significant negative correlation with above performance traits. For IDVGA-46, the individuals with allele 205 had a good muscular development at loin width, on the contrary, the allele 211, which was not found in Piemontese cattle, had a negative correlation with shoulder development. Allele 203 (IDVGA-55) had a positive association with body measurement parameters including wither height, body length, height at hip cross and rump width.

Novel point mutation within intron 10 of FMR-1 gene causing fragile X syndrome

The majority of cases involving fragile X syndrome are due to expansion of a (CGG)n trinucleotide repeat at the 5' untranslated region of the FMR-1 gene. Deletion and intragenic loss of function mutations of the FMR-1 gene also have been reported. Here, we report a C to T point mutation at the 14th nucleotide in intron 10 of the FMR-1 gene in three unrelated fragile X patients. However, the (CGG)n repeat of FMR-1 in those patients does not expand. To determine the effect of this mutation on the patients' FMR-1 transcripts, total RNA from peripheral blood cells was reverse transcribed and amplified by polymerase chain reaction (RT-PCR). Direct and subcloned sequencing of the RT-PCR products revealed that the transcripts from the allele with C to T mutation skip exon 10 entirely, resulting in a joining of exons 9 and 11. Deletion of exon 10 results in frame-shift and premature termination of translation, which removes the highly conserved region that encoding the KH2 and RGG box domains of FMRP. Interestingly, a male of the three patients has another G to A substitution in exon 15. However, the intron 10 mutation is sufficient for development of fragile X syndrome.

Inhibition of farnesyltransferase with A-176120, a novel and potent farnesyl pyrophosphate analogue

Farnesylation of Ras is required for its transforming activity in human cancer and the reaction is catalysed by the enzyme farnesyltransferase. Recently, we discovered a novel chemical series of potent farnesyl pyrophosphate (FPP) analogues which selectively inhibited farnesyltransferase. Our most potent compound to date in this series, A-176120, selectively inhibited farnesyltransferase activity (IC(50) 1.2+/-0.3 nM) over the closely related enzymes geranylgeranyltransferase I (GGTaseI) (IC(50) 423+/-1.8 nM), geranylgeranyltransferase II (GGTaseII) (IC(50) 3000 nM) and squalene synthase (SSase) (IC(50)>10000 nM). A-176120 inhibited ras processing in H-ras-transformed NIH3T3 cells and HCT116 K-ras-mutated cells (ED(50) 1.6 and 0.5 microM, respectively). The anti-angiogenic potential of A-176120 was demonstrated by a decrease in Ras processing, cell proliferation and capillary structure formation of human umbilical vein endothelial cells (HUVEC), and a decrease in the secretion of vascular endothelial growth factor (VEGF) from HCT116 cells. In vivo, A-176120 reduced H-ras NIH3T3 tumour growth and extended the lifespan of nude mice inoculated with H- or K-ras-transformed NIH3T3 cells. A-176120 also had an additive effect in combination with cyclophosphamide in nude mice inoculated with K-ras NIH3T3 transformed cells. Overall, our results demonstrate that A-176120 is a potent FPP mimetic with both antitumour and anti-angiogenic properties.

Histopathological examination of chemo-sympathectomy in cats

In recent decades, there has been an increase in both the number of sympathectomy techniques, as well as the surgical findings of sympathetic anatomy. Currently the advanced technique of C-arm guided percutaneous thoracic chemo-sympathectomy is widely used for the treatment of palmar hyperhidrosis. However, a better understanding of chemical agents in sympathectomy is required. In this study, chemo-sympathectomy was performed in cats, using alcohol, glycerol and various concentrations of phenol, to determine the chronic neurotoxic effects of these chemical agents on the stellate ganglia. The stellate ganglia of 24 cats were exposed under endotracheal general anesthesia, then injected with about 0.02 ml of absolute alcohol, glycerol and phenol (10%, 25%, 50%, and 75% concentration) solutions, respectively. The stellate ganglia were taken for histological examination three weeks after the chemical injection. The results showed that the degenerative changes in the cytoplasm and nucleus of ganglionic cells and intercellular tissue were moderate and relatively moderate after the injection of alcohol and glycerol, respectively. Meanwhile, the stellate ganglia revealed mild, relatively moderate, serious and extremely serious degeneration after injection of 10%, 25%, 50%, and 75% phenol, respectively. In conclusion, we recommend a high concentration of phenol, in the least volume, as a chemical agent for clinical injection in the upper thoracic sympathetic ganglion.