Single-port laparoscopic extraperitoneal repair of pediatric inguinal hernias and hydroceles by using modified Kirschner pin: a novel technique

BACKGROUND

The development of laparoscopic processus vaginalis repair has provided an alternative approach to the management of inguinal hernia and hydroceles in children. Here we describe our new technique for laparoscopic extraperitoneal ligation of processus vaginalis with subumbilical single-port using a modified Kirschner pin.

METHODS

A 5-mm trocar for an operative laparoscope was placed through an infraumbilical incision. A Kirschner pin with a hole in one flat terminal was inserted at the point of the internal inguinal ring. The processus vaginalis was closed extracorporeally by a non-absorbable suture, which was introduced into the abdomen through the Kirschner pin performing dissection within the extraperitoneal space in a series of movements. When a contralateral patent processus vaginalis is present, laparoscopic-assisted extracorporeal ligation is performed during the same operation.

RESULTS

Between September 2010 and September 2012, 211 children (130 cases of inguinal hernia and 81 cases of hydrocele) underwent processus vaginalis repair using this novel technique. A contralateral patent processus vaginalis was present and thus simultaneously closed in 20 patients with unilateral inguinal hernias and 12 patients with unilateral hydroceles. The mean operative time was 18 min (8-35 min). The mean follow-up period is 12 months (range 5-24 months), and no recurrence and complications has been observed to date.

CONCLUSIONS

This article describes a unique technique of extracorporeal circuit ligation of processus vaginalis using a minimally invasive technique as afforded by a reused modified Kirschner pin. Single-port laparoscopic processus vaginalis repair using this instrument is feasible and seems to be safe.

A 12-week intramuscular toxicity study of risperidone-loaded microspheres in Beagle dogs

Long-acting formulations of antipsychotics are important treatment options to increase the compliance of schizophrenic patients. Risperidone, a 5-HT2 and dopaminergic D2 receptor antagonist, was developed as long-acting sustained-release microspheres with poly(lactide-co-glycolide) (PLGA) as a drug carrier for the treatment of schizophrenia. In the present study, the main objective is to determine the nonclinical safety profile of risperidone-loaded microspheres (RM) in Beagle dogs after intramuscular administration for 3 months, once in 2 weeks, followed by 8-week recovery phase. No animal death was found and no special toxicological findings were observed. The findings, such as hypoactivity, ptosis, increased heart rate, and elevated serum and pituitary prolactin levels, were observed and related to the pharmacological effects of risperidone. The changes in the reproductive system (uterus, ovary, vagina, cervix, and mammary gland) were considered secondary to the prolactin elevation, and the congestion of spleen was related to risperidone. The foreign body granulomas at injection sites might be caused by PLGA. At the end of recovery phase, the above changes mostly recovered to normal, and on administering 3 mg/kg dose level once in 2 weeks on Beagle dogs showed no observed adverse effect. Taken together, RM had exhibited the acceptable safety.

Cysteamine improves growth performance and gastric ghrelin expression in preweaning piglets

The aim of the present study was to investigate the effect of cysteamine on growth performance of preweaning piglets and gastric expression of ghrelin mRNA in vivo and in vitro. Twelve litters of newborn piglets were allocated randomly to control and treatment groups. From 15 d of age, piglets in the control group were fed basal creep diet, whereas the treatment group received basal diet supplemented with 120 mg cysteamine per kg of diet until weaning on 35 d of age. Body weight gain, creep feed consumption, and diarrhea rates were recorded, and gastric mucosal tissues were collected for quantifying mRNA expression. To evaluate the direct effect of cysteamine on gastric ghrelin expression, primary cultures of gastric mucosal cells isolated from 35-d-old piglets were exposed to cysteamine for 20 h at 0, 1, 10, and 100 μg/mL, respectively. Dietary cysteamine increased (P < 0.05) average daily creep feed consumption and BW gain in preweaning pigs, which was accompanied by reduction in diarrhea rates. At 35 d of age, piglets treated with cysteamine showed increased (P < 0.05) ghrelin and gastrin and decreased (P < 0.05) somatostatin mRNA expression in gastric mucosa. Moreover, dietary cysteamine treatment increased serum concentration of gastrin (P < 0.05). In vitro, cysteamine significantly increased ghrelin mRNA expression in gastric mucosal cells at the concentration of 10 μg/mL. In conclusion, dietary cysteamine is effective in improving the growth performance and health condition of preweaning piglets, which is associated with its stimulatory effects on gastric ghrelin mRNA expression both in vivo and in vitro.

Induction and repair of DNA double-strand breaks assessed by gamma-H2AX foci after irradiation with pulsed or continuous proton beams

In particle tumor therapy including beam scanning at accelerators, the dose per voxel is delivered within about 100 ms. In contrast, the new technology of laser plasma acceleration will produce ultimately shorter particle packages that deliver the dose within a nanosecond. Here, possible differences for relative biological effectiveness in creating DNA double-strand breaks in pulsed or continuous irradiation mode are studied. HeLa cells were irradiated with 1 or 5 Gy of 20-MeV protons at the Munich tandem accelerator, either at continuous mode (100 ms), or applying a single pulse of 1-ns duration. Cells were fixed 1 h after 1-Gy irradiation and 24 h after 5-Gy irradiation, respectively. A dose-effect curve based on five doses of X-rays was taken as reference. The total number of phosphorylated histone H2AX (gamma-H2AX) foci per cell was determined using a custom-made software macro for gamma-H2AX foci counting. For 1 h after 1-Gy 20-MeV proton exposures, values for the relative biological effectiveness (RBE) of 0.97 ± 0.19 for pulsed and 1.13 ± 0.21 for continuous irradiations were obtained in the first experiment 1.13 ± 0.09 and 1.16 ± 0.09 in the second experiment. After 5 Gy and 24 h, RBE values of 0.99 ± 0.29 and 0.91 ± 0.23 were calculated, respectively. Based on the gamma-H2AX foci numbers obtained, no significant differences in RBE between pulsed and continuous proton irradiation in HeLa cells were detected. These results are well in line with our data on micronucleus induction in HeLa cells.

Differential involvement of striato- and cerebello-thalamo-cortical pathways in tremor- and akinetic/rigid-predominant Parkinson's disease

Parkinson's disease (PD) presents clinically with varying degrees of resting tremor, rigidity, and bradykinesia. For decades, striatal-thalamo-cortical (STC) dysfunction has been implied in bradykinesia and rigidity, but does not explain resting tremor in PD. To understand the roles of cerebello-thalamo-cortical (CTC) and STC circuits in the pathophysiology of the heterogeneous clinical presentation of PD, we collected functional magnetic resonance imaging (fMRI) data from 17 right-handed PD patients [nine tremor predominant (PDT) and eight akinetic-rigidity predominant (PDAR)] and 14 right-handed controls while they performed internally-guided (IG) sequential finger tapping tasks. The percentage of voxels activated in regions constituting the STC and CTC [divided as cerebellar hemisphere-thalamo-cortical (CHTC) and vermis-thalamo-cortical (CVTC)] circuits was calculated. Multivariate analysis of variance compared the activation patterns of these circuits between study groups. Compared to controls, both PDAR and PDT subjects displayed an overall increase in the percentage of voxels activated in both STC and CTC circuits. These increases reached statistical significance in contralateral STC and CTC circuits for PDT subjects, and in contralateral CTC pathways for PDAR subjects. Comparison of PDAR and PDT subjects revealed significant differences in ipsilateral STC (P=0.005) and CTC (P=0.043 for CHTC and P=0.003 for CVTC) circuits. These data support the differential involvement of STC and CTC circuits in PD subtypes, and help explain the heterogeneous presentation of PD symptoms. These findings underscore the importance of integrating CTC circuits in understanding PD and other disorders of the basal ganglia.

Tannin-based rigid foams: a survey of chemical and physical properties

Tannin-based rigid foams, prepared from 95% natural material, are suggested for replacing synthetic phenol-formaldehyde foams in various applications. For that purpose, a few physical properties were measured and reported here: resistance to fire and chemicals, absorption of various liquids, permeability, thermal conductivity and mechanical (compressive and tensile) strength. Modifying the composition through the use of boric and/or phosphoric acid allowed substantial increase of fire resistance. The materials were also found to present good resistance to strong acid and bases, and to solvents. High affinity for water, but limited one for organic liquids, was also evidenced. Finally, slightly anisotropic mechanical properties were measured. The materials present a brittle behaviour, whether tested in compression or traction; nevertheless, their strengths, as well as their thermal conductivities, are fully comparable with those of their phenolic counterparts. We show that such materials of vegetable origins can compete with synthetic ones for most of traditional applications.

Elevated glutathione production by adding precursor amino acids coupled with ATP in high cell density cultivation of Candida utilis

AIMS

Three precursor amino acids and adenosine triphosphate (ATP) are necessary for fermentative production of glutathione. In this study, our aims were to develop a strategy to enhance glutathione production by adding three precursor amino acids coupled with ATP in high cell density (HCD) cultivation of Candida utilis.

METHODS AND RESULTS

A high-glutathione yeast strain, C. utilis WSH 02-08, was used in this study. Whole fermentative process for glutathione production was divided into two phases of cell growth and glutathione synthesis. Cells concentration was increased by HCD cultivation. Meanwhile, intracellular glutathione content was enhanced by the addition of three precursor amino acids. Concentrations of three precursor amino acids added at stationary phase were optimized by response surface methodology. Moreover, the addition of ATP 15 h after the addition of the three amino acids can further enhance glutathione production. Based on aforementioned phenomenon, a strategy of adding three precursor amino acids coupled with ATP was developed to enhance glutathione production.

CONCLUSION

Without the addition of three precursor amino acids and the ATP, a total glutathione of 1123 mg l(-1) was achieved after 60-h cultivation. In comparison, addition of three precursor amino acid counterparts resulted in a total glutathione of 1841 mg l(-1). Moreover, by adding amino acids combined with ATP, a total glutathione of 2043 mg l(-1) was achieved after 72-h cultivation, increased by 81.9% and 11%, respectively, as compared with the control and the one without ATP addition.

SIGNIFICANCE AND IMPACT OF THE STUDY

This is the first report on investigating changes of the intracellular three precursor amino acids and ATP, and gamma-glutamylcysteine synthase activity in HCD cultivation of C. utilis for glutathione production. A strategy of combining addition of three precursor amino acids with ATP was developed to enhance glutathione production in C. utilis.

Enhancement of glutathione production by altering adenosine metabolism of Escherichia coli in a coupled ATP regeneration system with Saccharomyces cerevisiae

AIMS

Adenosine triphosphate (ATP) during the enzymatic production of glutathione is necessary. In this study, our aims were to investigate the reason for low glutathione production in Escherichia coli coupled with an ATP regeneration system and to develop a new strategy to improve the system.

METHODS AND RESULTS

Glutathione can be synthesized by enzymatic methods in the presence of ATP and three precursor amino acids (L-glutamic acid, L-cysteine and glycine). In this study, glutathione was produced from E. coli JM109 (pBV03) coupled with an ATP regeneration system, by using glycolytic pathway of Saccharomyces cerevisiae WSH2 as ATP regenerator from adenosine and glucose. In the coupled system, adenosine used for ATP regeneration by S. cerevisiae WSH2 was transformed into hypoxanthine irreversibly by E. coli JM109 (pBV03). As a consequence, S. cerevisiae WSH2 could not obtain enough adenosine for ATP regeneration in the glycolytic pathway in spite of consuming 400 mmol l(-1) glucose within 1 h. By adding adenosine deaminase inhibitor to block the metabolism from adenosine to hypoxanthine, glutathione production (8.92 mmol l(-1)) enhanced 2.74-fold in the coupled system.

CONCLUSIONS

This unusual phenomenon that adenosine was transformed into hypoxanthine irreversibly by E. coli JM109 (pBV03) revealed that less glutathione production in the coupled ATP regeneration system was because of the poor efficiency of ATP generation.

SIGNIFICANCE AND IMPACT OF THE STUDY

The results presented here provide a strategy to improve the efficiency of the coupled ATP regeneration system for enhancing glutathione production. The application potential can be microbial processes where ATP is needed.

A fast online hit verification method for the single ion hit system at GSI

For a single ion hit facility built to irradiate specific targets inside biological cells, it is necessary to prove that the ions hit the selected targets reliably because the ion hits usually cannot be seen. That ability is traditionally tested either indirectly by aiming at pre-etched tracks in a nuclear track detector or directly by making the ion tracks inside cells visible using a stain coupled to special proteins produced in response to ion hits. However, both methods are time consuming and hits can be verified only after the experiment. This means that targeting errors in the experiment cannot be corrected during the experiment. Therefore, we have developed a fast online hit verification method that measures the targeting accuracy electronically with a spatial resolution of +/-1 microm before cell irradiation takes place.

Enhanced intracellular glutathione synthesis and excretion capability of Candida utilis by using a low pH-stress strategy

AIMS

To study the effect of low pH stress on glutathione (GSH) synthesis and excretion capability of GSH fermentation production in Candida utilis.

METHODS AND RESULTS

When C. utilis WSH 02-08 was cultivated in a glucose-ammonium sulfate medium without pH control, GSH leakage occurred when the pH of the medium decreased to 1.5. However, analysis of the cell viability indicated that the cells were not lysed. To further study the effect of low pH stress on GSH production, pH-controlled batch cultures were conducted, where the pH was switched from 5.5 to 1.2 at 24 h and maintained at 1.2 for 6 h. Nearly all intracellular GSH was leaked into the medium and the cell viability decreased dramatically, conceiving a long-term exposure of strain WSH 02-08 at low pH environment led to a complete cell lysis. A critical point (treated at pH 1.2 for 3 h) was experimentally determined, where most cells were alive but suffering a low pH stress. Low pH-stressed C. utilis cells displayed an increased intracellular GSH synthesis and export capability, which protected the cells against short-term low pH treatment.

CONCLUSIONS

Using this knowledge, a low pH-stress strategy was developed and applied in fed-batch production of GSH and 197.3 mg l-1 of GSH was secreted into the medium. The GSH-specific production yield could be increased from 2.11 to 2.67% (w/w), and the total GSH concentration could reach 737.1 mg l-1 and increased by 24.9%.

SIGNIFICANCE AND IMPACT OF THE STUDY

This is the first report of GSH secretion of C. utilis at low pH. This study demonstrated the importance of the physiology-based fermentation strategy in the production of useful metabolites.

Hand-assisted transperitoneal laparoscopic living donor nephrectomy

OBJECTIVE

We introduced and evaluated the advantages and disadvantages of the hand-assisted transperitoneal laparoscopic technique for living donor nephrectomy.

MATERIALS AND METHODS

In December 2001, we started using the technique of hand-assisted transperitoneal laparoscopic living donor nephrectomy (HLDN) in 10 cases. The procedure utilizes a hand-assisted device to increase safety and control of the laparoscopic technique.

RESULTS

Only left nephrectomy was performed. The mean total operating and the warm ischemia times were 130 minutes and 3.0 minutes, respectively. Average lengths of renal artery and vein were 1.95 cm and 2.8 cm, respectively. There were no intraoperative or postoperative complications.

CONCLUSIONS

HLDN is an easier procedure than the traditional laparoscopic living donor nephrectomy and can greatly mitigate the learning curve. HLDN has shortened warm ischemia time and operating time. It is also good for trocar placement, prevention of torsion of the kidney, control of potential bleeding at the final stage of vascular stapling, and kidney removal. Therefore, HLDN is a promising method for living donor nephrectomy.

[Present situation in the study of antisperm antibodies]

Immune factors account for 5%-15% of male infertility. Because of the diversity in molecular weight, structure and location, sperm antigens play different roles in immune infertility. Antisperm antibodies (AsAb) influence sperm function not only by direct action, but also by changing the local microenvironment indirectly. This paper reviews the progress in the studies of the implication of human sperm antigens, the function, mechanisms, categories and titer of AsAb in male infertility.

[Advances in clinical application of nocturnal penile tumescence monitoring to diagnosis and treatment of erectile dysfunction]

Nocturnal penile tumescence is a normal physiological behavior of males. Nocturnal penile tumescence monitoring is one of the most effective methods to differentiate between organic and psychological erectile dysfunctions. Nocturnal penile tumescence monitoring has reportedly been applied to the diagnosis and treatment of erectile dysfunction as well as to the researches on the mechanism of nocturnal penile tumescence.

A novel polygalacturonic acid bioflocculant REA-11 produced by Corynebacterium glutamicum: a proposed biosynthetic pathway and experimental confirmation

Corynebacterium glutamicum CCTCC M201005 produces a novel polygalacturonic acid bioflocculant, REA-11, consisting of galacturonic acid as the main structural unit. A biosynthetic pathway of REA-11 in C. glutamicum CCTCC M201005 was proposed. Evidence for the biosynthetic pathway was provided by: (1) analyzing the response upon addition of UDP-glucose to the culture medium; (2) detecting the presence of several key intermediates in the pathway; and (3) correlating the activities of several key enzymes involved in the pathway with the yields of polygalacturonic acid. The production of polygalacturonic acid was improved by 24%, while the activities of UDP-galactose epimerase and UDP-galactose dehydrogenase were improved by 200% and 50%, respectively, upon addition of 100 microM UDP-glucose. In addition, the key intermediates in the proposed biosynthetic pathway, such as UDP-glucose, UDP-galactose, and UDP-glucuronic acid, were detected in cell-free extracts. Furthermore, the activities of UDP-glucose pyrophosphorylase (R2=0.97), UDP-galactose epimerase (R2=0.75) and UDP-galactose dehydrogenase (R2=0.89) were well correlated with the yields of polygalacturonic acid when different sugars were used as sole carbon sources. Therefore, the biosynthetic pathway of REA-11 in C. glutamicum CCTCC M201005 starts from phosphate-1-glucose, which was then converted to UDP-glucose by UDP-pyrophosphorylase. Predominantly, the UDP-glucose was converted to UDP-galactose by UDP-galactose epimerase; the latter was further converted to UDP-galacturonic acid by UDP-galactose dehydrogenase, which was presumably polymerized to polygalacturonic acid bioflocculant REA-11 by an unknown glucosyltransferase and a polymerase.

A role for phospholipase D1 in neurotransmitter release

Phosphatidic acid produced by phospholipase D (PLD) as a result of signaling activity is thought to play a role in membrane vesicle trafficking, either as an intracellular messenger or as a cone-shaped lipid that promotes membrane fusion. We recently described that, in neuroendocrine cells, plasma membrane-associated PLD1 operates at a stage of Ca(2+)-dependent exocytosis subsequent to cytoskeletal-mediated recruitment of secretory granules to exocytotic sites. We show here that PLD1 also plays a crucial role in neurotransmitter release. Using purified rat brain synaptosomes subjected to hypotonic lysis and centrifugation, we found that PLD1 is associated with the particulate fraction containing the plasma membrane. Immunostaining of rat cerebellar granule cells confirmed localization of PLD1 at the neuronal plasma membrane in zones specialized for neurotransmitter release (axonal neurites, varicosities, and growth cone-like structures). To determine the potential involvement of PLD1 in neurotransmitter release, we microinjected catalytically inactive PLD1(K898R) into Aplysia neurons and analyzed its effects on evoked acetylcholine (ACh) release. PLD1(K898R) produced a fast and potent dose-dependent inhibition of ACh release. By analyzing paired-pulse facilitation and postsynaptic responses evoked by high-frequency stimulations, we found that the exocytotic inhibition caused by PLD1(K898R) was not the result of an alteration in stimulus-secretion coupling or in vesicular trafficking. Analysis of the fluctuations in amplitude of the postsynaptic responses revealed that the PLD1(K898R) blocked ACh release by reducing the number of active presynaptic-releasing sites. Our results provide evidence that PLD1 plays a major role in neurotransmission, most likely by controlling the fusogenic status of presynaptic release sites.

Comparison of methods for erythroblast selection: application to selecting fetal erythroblasts from maternal blood

BACKGROUND

Many methods have been employed to obtain fetal cells from maternal blood for prenatal diagnostics, but there has been little work done that compares the efficacy of different methods. This study presents a comparison of two commonly used methods for selecting erythroblasts with selection directly from whole blood.

METHODS

Erythroblasts were isolated from maternal blood by either differential lysis or density separation, followed by selection with an antibody to the transferrin receptor. These methods were compared with antibody selection directly from whole blood. The total yield of erythroblasts was determined for each method.

RESULTS

Red cell lysis is not recommended because the lysis step cannot be well controlled. Density separation followed by antibody selection works well. However, a faster and simpler method, antibody selection directly from whole blood using Immunicon Ferrofluid and magnetic separators, works as well and has the potential to yield even more cells.

CONCLUSIONS

Considering the need for a simple and quick method for selecting fetal cells from maternal blood, we suggest selection directly from whole blood.

[Brain-stem cavernous hemangioma: surgical indications and approaches]

OBJECTIVE

To evaluate the surgical indications and prognosis for cavernous hemangiomas (CHs) in the brain-stem.

METHODS

From 1992 to 2000, 163 patients with intracranial CHs were operated on in our department. Among them, 14 patients (8 women and 6 men; mean age 42 years) had 15 CHs in the pons (12), mesencephalon (1) and medulla oblongata (1). Surgical indications for CHs are: progressive focal neurological deficits; hemorrhage; near the surface of the brainstem. Transvemian approach with midline suboccipital craniotomy was used for the lesions in the pons and medulla, near the floor of the IV cerebral ventricle. Transpetrosal approach was used for the lesions in the anterior part of the pons, and infratentorial supracerebellar approach for those in the mesencephalic case.

RESULTS

CHs were totally removed from all the 15 lesions. Neurological deficits were improved in 10 patients after operation. Two patients had transient worsening of neurological conditions, which returned to the preoperative status during follow-up. The mesencephalic case, however had neurological condition deteriorated and was homebound after surgery. Pathologically, an oligodendroglioma was seen with CH in this case.

CONCLUSIONS

If surgically indicated, CHs involving the brain-stem can be resected. Minimal invasiveness techniques and careful operative planning may contribute to the treatment of CHs involving the brain-stem.

[Identification of the genome of a picornavirus isolate using Random-PCR]

OBJECTIVE

To identify the genome of an enterovirus isolate (XJ90).

METHODS

The double-stranded cDNA of isolated virus was synthesized with anchored-random primer and was amplified with anchor primer; the PCR products were cloned into pGEM-T vector for sequencing and analysis.

RESULTS

Analysis on agarose gel electrophoresis of the Random-PCR products showed a typical smear; 11 randomly selected clones were all homologous to the members of enteroviruses and the homology rate over 80%; the 11 clones were distributed evenly along the whole genome and they assembled 4 contigs totally 2 261 bp long which covered 30% of the genome. The homology of the fourth contig and coxsackie virus B6 was 97.3% at amino acids level. The virus gene was specifically amplified with primers derived from the sequenced clones.

CONCLUSIONS

The picornavirus isolate XJ90 is a member of enteroviruses.

Management of hemangiopericytomas in the central nervous system

OBJECTIVE

To elucidate the clinical features and treatment of Hemangiopericytomas (HPCs) in the central nervous system.

METHODS

Twenty-six HPC operations performed at Huashan Hospital from January 1993 to June 1999 were analyzed retrospectively, and a review of relevant literatures was done.

RESULTS

Among the 26 cases, total tumor removal was achieved in 24 cases, and subtotal removal in 2 cases. Postoperatively, neurological symptoms were improved or unchanged in 21 cases, worsened in 4 cases, and pneumonia caused death in 1 case. Eighteen patients received postoperative radiotherapy. Eighteen patients were followed up from 1 month to 58 months (average, 22 months). During the follow-up period, 2 patients presented one or more distant metastasis, and one patient died of recurrence.

CONCLUSION

Surgical management is the best choice for treatment of patients with HPCs. Postoperative radiotherapy can postpone the risk of tumor recurrence.

ASH2L: alternative splicing and downregulation during induced megakaryocytic differentiation of multipotential leukemia cell lines

Abstract Drosophila ash2 is a member of the trxG gene super family, some human homologues of which are involved in hematopoiesis and leukemia. We report here the identification of the human homologue of Drosophila ash2 and its alternative splicing isoform, ASH2L1 and ASH2L2. ASH2L proteins are 60% homologous to Drosophila ash2. ASH2L also has a zinc finger motif (C2C2) although it is not identical to that in ASH2. Expression profile analysis showed that the amount of ASH2L transcripts is extremely high in fetal liver, testis, and leukemia cell lines with erythroid and megakaryocytic potential such as K562, Hel, and Dami. We treated these cells with differentiation inducers phorbol ester and hemin. We found that ASH2L is downregulated rapidly and dramatically in K562, Hel, and Dami cells during phorbol ester induced differentiation with megakaryocytic features. However, its expression is maintained at a high level during erythroid differentiation of K562 cells induced with hemin. These results suggest that ASH2L plays a role in hematopoiesis and is associated with some special kinds of leukemia.

[The expression of HCV RNA polymerase in E.coli and the study of its solubility and antigenicity]

OBJECTIVE

To express HCV RNA polymerase and study its soluble condition and antigenicity.

METHODS

We constructed expression vectors pQE-5B-Fl and pQE-5B-C21 and expressed them in E.coli (M15). We analyzed their solubility in different conditions and purified soluble pQE-5B-C21 protein by Ni-NTA column, then detected its antigenicity by ELISA and western blot.

RESULTS

We obtained the purified soluble pQE-5B-C21 protein in the induction conditions of 18 degrees C and the protein was proved to be of good antigenicity by ELISA and western blot.

CONCLUSIONS

The RNA polymerase of HCV expressed in E.coli has good solubility and antigenicity.

Continuous production of poly-3-hydroxybutyrate by Ralstonia eutropha in a two-stage culture system

Poly-3-hydroxybutyrate (PHB) is mainly accumulated by Ralstonia eutropha under unbalanced growth conditions, which limits its production in batch or fed-batch modes. The continuous production of PHB was investigated in a two-stage continuous culture system. The first-stage produced cell mass giving the maximal cell dry weight of 27.1 g l(-1) at 0.21 h(-1) of dilution rate. High specific cell growth rate results in the decrease of PHB synthesis under glucose-limited and nitrogen-rich conditions in the first-stage. The second-stage produced PHB giving the maximal PHB concentration of 47.6 g l(-1) at 0.14 h(-1) of dilution rate. Specific PHB synthetic rate reached highest value at low dilution rate under nitrogen-limited condition in the second-stage, and decreased with the increase of ammonium concentration in the culture. In the continuous culture system, the maximal PHB productivity could reach 1.43 g l(-1) h(-1) at a dilution rate of 0.12 h(-1), but with relatively low PHB content of 47.6%. Maximal yield of PHB on glucose could reach 0.36 g g(-1) glucose at 0.075 h(-1) of dilution rate with relatively high PHB productivity of 1.23 g l(-1) h(-1) and PHB content of 72.1%, respectively.

Expression of multidrug-associated protein, P-glycoprotein, P53 and Bcl-2 proteins in bladder cancer and clinical implication

The expression of multidrug resistant proteins in bladder cancer and clinical implication was studied. Expression of multidrug-associated protein (MRP), P-glycoprotein (P-gp), P53 and Bcl-2 proteins were detected by using immunohistochemical method in 40 specimens of bladder transitional cell carcinoma. The results showed that the positive rate of MRP, P-gp, P53 and Bcl-2 was 52.5%, 57.5%, 47.5% and 62.5% respectively. The positive rate of MRP, P-gp, P53 and Bcl-2 in the grade I, II and III of tumors was 46.3%, 38.5%, 38.5%, 23.1%; 52.9%, 39.8%, 47.1%, 76.4%; 60.0%, 80.0%, 60.0%, 90.0% respectively. The positive rate of MRP, P-gp, P53 and Bcl-2 in 24 primary tumor specimens was 37.5%, 41.7%, 33.3%, 45.8% and that in 16 cases in recurrent specimens receiving chemotherapy 75.0%, 81.3%, 68.8%, 87.5% respectively. It was suggested the positive rate of MRP, P-gp, P53 and Bcl-2 was increased with the advance of tumor grade. The positive rate of four proteins in all recurrent cases was significantly increased (P < 0.05). The expression of MRP, P-gp, P53 and Bcl-2 proteins might be the important factors for chemotherapy failure.

Dual requirement for rho and protein kinase C in direct activation of phospholipase D1 through G protein-coupled receptor signaling

G protein-coupled and tyrosine kinase receptor activation of phospholipase D1 (PLD1) play key roles in agonist-stimulated cellular responses such as regulated exocytosis, actin stress fiber formation, and alterations in cell morphology and motility. Protein Kinase C, ADP-ribosylation factor (ARF), and Rho family members activate PLD1 in vitro; however, the actions of the stimulators on PLD1 in vivo have been proposed to take place through indirect pathways. We have used the yeast split-hybrid system to generate PLD1 alleles that fail to bind to or to be activated by RhoA but that retain wild-type responses to ARF and PKC. These alleles then were employed in combination with alleles unresponsive to PKC or to both stimulators to examine the activation of PLD1 by G protein-coupled receptors. Our results demonstrate that direct stimulation of PLD1 in vivo by RhoA (and by PKC) is critical for significant PLD1 activation but that PLD1 subcellular localization and regulated phosphorylation occur independently of these stimulatory pathways.

Insulin-induced phospholipase D1 and phospholipase D2 activity in human embryonic kidney-293 cells mediated by the phospholipase C gamma and protein kinase C alpha signalling cascade

Phospholipase D (PLD)1 is quiescent in vitro and in vivo until stimulated by classical protein kinase C (PKC) isoforms, ADP-ribosylation factor or Rho family members. By contrast, PLD2 has high basal activity, and the mechanisms involved in agonist-induced activation of PLD2 are poorly understood. Using transiently transfected human embryonic kidney (HEK)-293 cells as a model system, we report in the present study that PLD2 overexpressed in HEK-293 cells exhibits regulatory properties similar to PLD1 when stimulated in response to insulin and phorbol ester. Co-expression of PLD1 or PLD2 with PKC alpha results in constitutive activation of both PLD isoforms, which cannot be further stimulated by insulin. Co-expression of PLD1 with phospholipase C (PLC)gamma has the same effect, while co-expression of PLD2 with PLC gamma allows PLD2 activity to be stimulated in an insulin-dependent manner. The PKC-specific inhibitors bisindolylmaleimide and Gö 6976 abolish insulin-induced PLD2 activation in HEK-293 cells co-expressing the insulin receptor, PLC gamma and PLD2, confirming that not only PLD1, but PLD2 as well, is regulated in a PKC-dependent manner. Finally, we provide evidence that PKC alpha is constitutively associated with PLD2. In summary, we demonstrate that insulin treatment results in activation of both PLD1 and PLD2 in appropriate cell types when the appropriate upstream intermediate signalling components, i.e. PKC alpha and PLC gamma, are expressed at sufficient levels.

Cardiac phospholipase D2 localizes to sarcolemmal membranes and is inhibited by alpha-actinin in an ADP-ribosylation factor-reversible manner

Myocardial phospholipase D (PLD) has been implicated in the regulation of Ca(2+) mobilization and contractile performance in the heart. However, the molecular identity of this myocardial PLD and the mechanisms that regulate it are not well understood. Using subcellular fractionation and Western blot analysis, we found that PLD2 is the major myocardial PLD and that it localizes primarily to sarcolemmal membranes. A 100-kDa PLD2-interacting cardiac protein was detected using a protein overlay assay employing purified PLD2 and then identified as alpha-actinin using peptide-mass fingerprinting with matrix-assisted laser desorption/ionization mass spectroscopy. The direct association between PLD2 and alpha-actinin was confirmed using an in vitro binding assay and localized to PLD2's N-terminal 185 amino acids. Purified alpha-actinin potently inhibits PLD2 activity (IC(50) = 80 nm) in an interaction-dependent and ADP-ribosylation factor-reversible manner. Finally, alpha-actinin co-localizes with actin and with PLD2 in the detergent-insoluble fraction from sarcolemmal membranes. These results suggest that PLD2 is reciprocally regulated in sarcolemmal membranes by alpha-actinin and ARF1 and accordingly that a major role for PLD2 in cardiac function may involve reorganization of the actin cytoskeleton.

[Survey on children's dental fluorosis and fluoride content in urine after defluridation to improve drinking water]

The authors surveyed the dental fluorosis and fluoride content in urine of 8-12 years old children's in 1993 to 1999 for the evaluation of the efficiency to prevent endemic fluorosis after defluoridation to change drinking water source in Guangdong Province. Three villages: slight fluorosis area in Dazhai village, middle fluorosis area in Hupi village and severe fluorosis area in Anquan village in Fengshun County were surveyed. The results showed that the fluoride contents in drinking water were 1 mg/L (or less) in Anquan village, at the same time the prevalence of dental fluorosis and indexes of dental fluorosis were decreasing as changing water time. Fluoride contents in urine were normal. But in other two villages, the fluoride contents in drinking water exceeded 1 mg/L, therefore the children's prevalence rates and indexes of dental fluorosis were higher than the national standards. It is important to keep fluoride contents in drinking water under 1 mg/L for preventing endemic fluorosis by defluoridation to improve drinking water.

[Effects of nitrogen feeding on the accumulation of poly-beta-hydroxybutyrate with Alcaligenes eutrophus]

On the basis of analysis of PHB fermentation processes, the effects of ammonium sulfate feeding rate at PHB formation period on the PHB accumulation by Alcaligenes eutrophus were investigated. It was shown that the complete absence of nitrogen source at PHB formation phase would lead to the decline of PHB synthetic activity, and the obvious influences of different nitrogen feeding rate on PHB synthesis were observed. Higher PHB content, but relative lower cell dry weight, PHB concentration and PHB productivity could be obtained at slower nitrogen feeding rate. The excessive nitrogen feeding rate resulted in the drop of PHB content, which led to the decrease of PHB concentration and PHB productivity. The better results could be achieved when the ammonium sulfate feeding rate was set at around 0.5 g/h.

Diagnosis and surgical treatment of posterior fossa solid hemangioblastomas

OBJECTIVE

To elucidate the diagnosis and surgical treatment of the posterior fossa solid hemangioblastomas (PFSHs).

METHODS

The data from 22 patients with PFSHs verified by surgery and pathology were analyzed retrospectively and a review of relevant literature was conducted.

RESULTS

The preoperative definitive diagnosis rate was 13/22. Total tumor removal was achieved in 20 patients. Two of the 22 patients died after surgery, one of brain-stem injury and the other from an intracranial hemorrhage. Twenty patients were followed up for 2 months to 8 years (average, 2 years). Kamofsky scale was > or = 80 in 15 patients, 60-70 in 1 patient and not measured in 4 patients who died during follow-up. The causes of death were pneumonia (2 patients) and purulent meningitis (2).

CONCLUSION

MRI and DSA (digital subtraction angiography) are major preoperative diagnostic modalities for PFSH, but PFSH remains a challenging benign neoplasm. Special microsurgical techniques and improved operative manipulation can improve surgical efficacy.

Correlative expression of glutathione S-transferase-pi and multidrug resistance associated protein in bladder transitional cell carcinoma

In order to elucidate the mechanisms of multidrug resistance (MDR) in bladder cancer, the expression of glutathione S-transferase-pi (GST-pi) and multidrug resistance associated protein (MRP) in tissue samples resected from 44 patients and 6 normal bladder mucosa as control was detected by using immunohistochemical method, and the results were analyzed by computer-assisted image analyzing system (IAS) to achieve semi-quantitative data. In addition, correlation between the expression of both factors was studied. The results showed that the positive expression rate of GST-pi and MRP in bladder cancer was 72.7% (32/44) and 68.2% (30/44) respectively, significantly higher than those in normal bladder mucosa, being 16.7% and 33.3% respectively. The rate of GST-pi positive staining was increased correspondingly with tumor grade and stage elevated, being higher in recurrent tumors treated by chemotherapy, but not significantly (P > 0.05). There was no significant differences between the expression of MRP and tumors' behaviors and clinical characters. However, the results demonstrated that the correlation between the expression of both resistant factors was very evident (r = 0.695, P < 0.0025). It was suggested that the activation of GST-pi and MRP might occur during malignant transformation of normal mucosa, but tumors' differentiation and progression could not be the unique factors that influenced both overexpression. Chemotherapy might be another important reason. The correlation of both indicated that there was a common mechanism regulating their expression probably, which made them play a pivotal role in chemotherapy drug resistance of bladder cancers.

[Effect of tian ma cu zhi chongji medicinal granules (TMCZCJ) on blood rheology in hypostasis rats due to stagnation of liver-qi and learning-memory disorder in cerebral ischemia-reperfusion mice]

OBJECTIVE

To investigate the effect of TMCZCJ on the blood rheology in hypostasis rats due to stagnation of the liver-qi and on the learning-memory disorder in cerebral ischemia-reperfusion mice.

METHOD

The models of hypostasis due to stagnation of the liver-qi were made by combining irritation with hypodemic injected adrenalin and ice-bath in rats, and the models of learning-memory disorder were made by repeatedly ligating-reperfusing the bilateral carotid in mice. The hypostasis rats and learning-memory disorder mice were perorally administrated TMCZCJ(7.7, 15.4 g.kg-1) once a day, for fourteen consecutive days.

RESULT

TMCZCJ can significantly reduce plasma viscosity, blood viscosity and reduced viscosity in hypostasis rats. It can also improve the latent learning-memory capability and memory gain-repetition ability in water-maze for cerebral ischemia-reperfusion mice.

CONCLUSION

TMCZCJ can improve remarkably blood rheology in hypostasis rats and learning-memory disorder in cerebral ischemia-reperfusion mice.

EGb 761 protects liver mitochondria against injury induced by in vitro anoxia/reoxygenation

The present study investigated the protective effects of Ginkgo biloba extract (EGb 761) on rat liver mitochondrial damage induced by in vitro anoxia/reoxygenation. Anoxia/reoxygenation was known to impair respiratory activities and mitochondrial oxidative phosphorylation efficiency. ADP/O (2.57 +/- 0.11) decreased after anoxia/reoxygenation (1.75 +/- 0.09, p < .01), as well as state 3 and uncoupled respiration (-20%, p < .01), but state 4 respiration increased (p < .01). EGb 761 (50-200 microg/ml) had no effect on mitochondrial functions before anoxia, but had a specific dose-dependent protective effect after anoxia/reoxygenation. When mitochondria were incubated with 200 microg/ml EGb 761, they showed an increase in ADP/O (2.09 +/- 0.14, p < .05) and a decrease in state 4 respiration (-22%) after anoxia/reoxygenation. In EPR spin-trapping measurement, EGb 761 decreased the EPR signal of superoxide anion produced during reoxygenation. In conclusion, EGb 761 specially protects mitochondrial ATP synthesis against anoxia/reoxygenation injury by scavenging the superoxide anion generated by mitochondria.

[Selection of human phage antibodies against HAV and DNA sequence analysis]

OBJECTIVE

To obtain the anti-HAV antibodies.

METHODS

The antibody-capturing antigen strategy was used in panning antibody library with impure antigen. The HAV-binding activity and specificity of phage antibodies were assayed by sandwich ELISA and competitive inhibition ELISA.

RESULTS

Phage antibodies(Fab) against HAV were screened from a human immunoglobulin combinatorial library. Fd and light chain genes were sequenced. Comparison of the Fd gene and light chain gene with KABAT database showed that the heavy chain belonged to IgG1 subclass, and its variable region was derived from rearranged germ-line gene of DP88, D3-3 and JH5; while the light chain was a member of V kappa III family, the germ-line gene was DP kappa 22 and J kappa 4.

CONCLUSION

Phage antibodies against HAV were selected from the antibody library by using the antibody-capturing antigen strategy. The result also suggested that the antibody library was constructed successfully.