[Risk assessment for thyroid (131)I exposure among nuclear medical staff].

Objective: To explore the main risk factors and to assess the risk of thyroid (131)I exposure among nuclear medical workers. Methods: From March to October in 2019, cluster sampling was adopted to collect the number of (131)I automatic packer and patients treated for thyroid cancer, hyperthyroidism and liven cancer used (131)I, the practicing categories, job rotation and (131)I operation condition of nuclear medical staff were also investegated in the 21 nuclear medicine hospitals in Fujian Province that carried out (131)I nuclide diagnosis and treatment in 2018. (131)I aerosol and personnel thyroid (131)I were measured in 20 hospitals using (131)I for thyroid cancer or hyperthyroidism. The main risk factors leading to thyroid (131)I exposure of nuclear medical staff were found and aninternal exposure risk assessment model was established. Results: The detection rate of (131)I aerosol and personnel thyroid (131)I were 80.0% (16/20) and 25.5% (62/243) in 20 hospitals. The situation of packaging and administration about (131)I in the nearly 10 effective half-life, the concentration of (131)I aerosol in the nuclear medicine workplace, the number of patients treated with (131)I for thyroid cancer or hyperthyroidism were the main risk factors leading to thyroid (131)I internal exposure (OR=5.857, 6.808, 1.983, 1.150, P<0.05) . Conclusion: (131)I exposure is common among nuclear medical workers, attention should be paid to the protection of internal radiation, strengthen the control of main risk factors, so as to reduce the risk of internal radiation.

[Percutaneous full-endoscopic removalof lumbar dumbbell tumors viatransforaminal approach].

Objective: To investigate the novel application and effectof Percutaneous Full-Endoscopic transforaminal approach for lumbar dumbbell tumors. Methods: A retrospective analysis of 12 cases of lumbar dumbbell tumors was conducted by Percutaneous full-endoscopic transforaminal approach in the Department of Neurosurgery, Fujian Medical University Union Hospital from Feb, 2018 to Jul, 2019. According to Eden classification, 5 cases in type Ⅲ and 7 cases in type Ⅳ. The Japanese Orthopaedic Association (JOA) score and Pain Visual analogue Scale (VAS) were used to compare the recovery of neurological function before and after surgery. Results: All the 12 tumors were completely removed in one stage. The pathological reports were all schwannomas (WHO grade Ⅰ). The VAS scores were significantly decreased compared with preoperative ones (P<0.001). The JOA scores were significantly improved without obvious complications and spinal instability. Median length of follow-up was 14 months with a range of 4 months to 20 months, there is no tumor recurrence and spinal instability. Conclusion: In the treatment of lumbar dumbbell spinal tumor, the full endoscopic transforaminal approach is a novel, safe and effective surgical procedure which removes the tumors intra-foramen and extra-foramen with less damage of spine, smaller possibility of instability and faster recovery.

Radio frequency measurement and tuning of a 13 MeV Alvarez-type drift tube linac for a compact pulsed hadron source.

This paper describes the radio frequency (RF) measurement and tuning result of a 13 MeV Alvarez-type drift tube linac (DTL) for a compact pulsed hadron source (CPHS) at Tsinghua University. The design, machining, assembly, and alignment of the DTL are presented for integrity. The CPHS project consists of a high-current proton linac (13 MeV, 16 kW, peak current of 50 mA, 0.5 ms pulse width at 50 Hz), a neutron target station, a small-angle neutron scattering instrument, and a neutron imaging/radiology station. The linac contains an electron cyclotron resonance ion source, a low energy beam transport line, a four-vane radio frequency quadrupole (RFQ) accelerator, an Alvarez-type DTL, a high energy beam transport line, and a RF power supply and distributor. Construction on the CPHS started in June 2009, and the CPHS has provided 2000 h since 2013 to users with the neutrons produced by the 3 MeV proton beam from the radio frequency quadrupole bombarding on the beryllium target as an achievement of its mid-term objective. Presently, the tuning of the assembled DTL cavity has been completed successfully. The 4.3-m-long DTL consists of 40 accelerating cells, among which 39 full-length drift tubes (DTs) are suspended inside the cavity, and two half-length DTs are mounted inside the two end flanges of the cavity. Each DT contains a permanent magnet quadrupole. Thirteen post couplers and nine tuners are available for the tuning of the field. The relative error of the field after tuning is within ±1.6%, with a tilt sensitivity within ±33%/MHz in all cells. The beam energy will reach its designed value of 13 MeV after the DTL is installed in the beam line downstream the 3 MeV RFQ accelerator.

[Application of dysphonia severity index in laryngeal reflux related voice diseases].

Objective:To discuss the validity and reliability of dysphonia severity index in evaluating the effect of diagnosis and treatment of laryngeal reflux related voice diseases. Method:54 cases of voice disease patients accompanied by laryngopharyngeal reflux from January 2016 to June 2017 in department of otorhinolaryngology of our hospital were divided into two groups according to treatment type. 32 cases in the operation group received laser surgery and standard acid suppression therapy for 6 weeks, and 22 patients in the non-operation group received standard acid suppression therapy for 6 weeks. 24 h multichannel impedance pH (MCII-pH) monitoring was carried out. The indexes of reflux symptom, reflux finding score, subjective auditory perception and objective acoustic parameters of voice were measured before and after treatment, and the dysphonia severity index was calculated and analyzed. Result:There was no significant difference in age, sex and course of disease between the two groups (P> 0.05).Compared with pre-treatment, RSI, RFS, Jitter, Shimmer, G and R in two groups decreased significantly after treatment, and MPT, DSI increased significantly (P<0.05). Before treatment, RSI, RFS, Jitter, Shimmer, G and R in the operation group were significantly higher than those in the non-operation group, and MPT, DSI were lower (P<0.05). There were no significant differences in the parameters between the two groups after treatment (P> 0.05). DSI was negatively correlated with GRBAS scoring parameters, Jitter and Shimmer, and positively correlated with RSI, RFS, and MPT (P<0.01). DSI is related to the location of the lesion (P<0.05) The incidence of anxiety was 27.27% in patients with moderate and severe sudden sensorineural hearing loss, and the incidence of depression was 25.25%. The scores of anxiety and depression were statistically significant (P<0.05). The multivariate logistic regression analysis showed that the status of anxiety and depression was accompanied by symptoms and other diseases (P<0.05). There was a significant difference between the effective group, the significant efficacy group and the cured group (P<0.05). The difference between the scores before and after treatment was compared. Differences in the ineffective group compared with the other three groups, and the cured group compared with the other three groups of anxiety, depression were statistically significant. Conclusion:DSI can be used as an objective evaluation index for the diagnosis and treatment of laryngeal reflux related voice diseases, and it is accurate and reliable.

Functionally graded calcium phosphate coatings produced by ion beam sputtering/mixing deposition.

Ar+ ion beam sputtering/mixing deposition was used to produce thin calcium phosphate coatings on titanium substrate from hydroxyl-poly-calcium sodium phosphate (HPPA) and HPPA + Ti targets. Three types of coatings (one type of monolayer coating and two types of functionally graded coating) were manufactured. It was found that as-sputtered coatings were amorphous. No distinct hydroxyl band was observed in the FTIR spectra, but new absorption bands were determined for CO3(2-), which resulted during the deposition process. Compositional gradients from the surface to the interior (i.e. adjacent to the substrate) were achieved for the functionally graded coatings. Post-deposition heat treatment indicated that the bonding strength between the coating and the substrate was improved by the use of functionally graded structures.

Strontium ranelate increases cartilage matrix formation.

Based on previous studies showing that strontium ranelate (S12911) modulates bone loss in osteoporosis, it could be hypothesized that this drug also is effective on cartilage degradation in osteoarthritis (OA). This was investigated in vitro on normal and OA human chondrocytes treated or not treated with interleukin-1beta (IL-1beta). This model mimics, in vitro, the imbalance between chondroformation and chondroresorption processes observed in vivo in OA cartilage. Chondrocytes were isolated from cartilage by enzymatic digestion and cultured for 24-72 h with 10(-4)-10(-3) M strontium ranelate, 10(-3) M calcium ranelate, or 2 x 10(-3) M SrCl2 with or without IL-1beta or insulin-like growth factor I (IGF-I). Stromelysin activity and stromelysin quantitation were assayed by spectrofluorometry and enzyme amplified sensitivity immunoassay (EASIA), respectively. Proteoglycans (PG) were quantified using a radioimmunoassay. Newly synthesized glycosaminoglycans (GAGs) were quantified by labeled sulfate (Na2(35)SO4) incorporation. This method allowed the PG size after exclusion chromatography to be determined. Strontium ranelate, calcium ranelate, and SrCl2 did not modify stromelysin synthesis even in the presence of IL-1beta. Calcium ranelate induced stromelysin activation whereas strontium compounds were ineffective. Strontium ranelate and SrCl2 both strongly stimulated PG production suggesting an ionic effect of strontium independent of the organic moiety. Moreover, 10(-3) M strontium ranelate increased the stimulatory effect of IGF-I (10(-9) M) on PG synthesis but did not reverse the inhibitory effect of IL-1beta. Strontium ranelate strongly stimulates human cartilage matrix formation in vitro by a direct ionic effect without stimulating the chondroresorption processes. This finding provides a preclinical basis for in vivo testing of strontium ranelate in OA.

Modulation of human chondrocyte metabolism by recombinant human interferon.

OBJECTIVES: Interferon gamma (IFN gamma) is found to be elevated in the synovial fluid of patients with rheumatoid arthritis and osteoarthritis, suggesting its implication in joint disease pathogenesis. In this study, we investigated the effects of IFN gamma on the production of cytokines (IL-6, IL-8, IL-10), prostaglandin E(2)(PGE(2)), proteoglycans (PG), nitric oxide (NO), interleukin-1 receptor antagonist (IL-1ra) and stromelysin by non-stimulated and IL-1 beta-treated human chondrocytes. The role played by NO in the responses of chondrocytes to IFN gamma was also examined by incubation of chondrocytes with N(G)-monomethyl-L-arginine (L-NMMA), a competitive inhibitor of NO synthase. METHODS: Enzymatically isolated human chondrocytes were cultured for 48 h in the absence or presence of IL-1 beta, IFN gamma or N(G)-monomethyl-L-arginine (L-NMMA) added solely or in combination. The productions of IL-6, IL-8, IL-10, IL-1ra and stromelysin were measured by enzyme amplified sensitivity immunoassays (EASIA). PG and PGE(2)were quantified by specific radioimmunoassays (RIA). Nitrite concentrations in the culture supernatants were determined by a spectrophotometric method based upon the Griess reaction. RESULTS: As expected, IL-1 beta highly stimulated NO, IL-6, IL-8, IL-10, IL-1ra, PGE(2)and stromelysin synthesis, but dramatically decreased PG production. NO, IL-6, IL-1ra and PGE(2)production by non-stimulated chondrocytes was dose-dependently increased by IFN gamma while PG production was inhibited. In the absence of IL-1 beta, IL-10 was undetectable in the culture supernatants. At the doses of 10 and 100 U/ml, IFN gamma markedly inhibited the constitutive and IL-1 beta-stimulated IL-8, IL-10 and stromelysin productions. Interestingly, IFN gamma synergized with IL-1 beta to increase NO, IL-6, IL-1ra and to depress PG production. As previously reported, the inhibition of NO synthesis by the competitive inhibitor L-NMMA led to enhancement of IL-6, IL-8 and PGE(2)production by IL-1 beta treated chondrocytes, but did not significantly modify IL-10, PG and MMP-3 productions. Inhibition of NO synthase significantly inhibited the stimulating effect of IFN gamma on IL-6 and IL-1ra but did not affect the inhibitory effect of IFN gamma on IL-8, PG or stromelysin production. CONCLUSIONS: These findings suggest that IFN gamma and IL-1 synergistically stimulate the production of IL-6, IL-1ra, NO and PGE(2)and inhibit PG synthesis. By contrast, IL-1 beta and IFN gamma have opposite effects on IL-8, IL-10 and stromelysin productions. These effects are not reversed by L-NMMA, suggesting that NO is not the principal mediator involved in responses of chondrocytes to IFN gamma.

In vitro study of the antioxidant properties of nimesulide and 4-OH nimesulide: effects on HRP- and luminol-dependent chemiluminescence produced by human chondrocytes.

OBJECTIVES: Reactive oxygen species (ROS) are now recognized to play an important role in the pathogenesis of rheumatic diseases and constitute an interesting therapeutic target for drugs. This in vitro study was designed to evaluate the antioxidant properties of nimesulide (NIM), a nonsteroidal antiinflammatory drug of the sulfonanilide class, and its main metabolite 4-OH nimesulide (4-OHNIM). METHODS: The scavenging effects of NIM and 4-OH NIM on hydroxyl radical ((.)OH) and superoxide anions (O(minusd)(2)) were investigated by electron spin resonance (ESR), using 5, 5-dimethylpyrroline-N-oxide (DMPO) as the spin trap agent. The quenching properties of these drugs on hypochlorite anion was studied by luminol enhanced chemiluminescence. Finally, the effects of NIM and 4-OHNIM on the reactive oxygen species production by human articular chondrocytes were recorded by HRP and luminol-enhanced chemiluminescence. RESULTS: By this method it has been demonstrated that NIM and 4-OHNIM, at concentrations ranging from 10 to 100 microM, are potent scavengers of(.)OH whereas only 4-OHNIM was capable to scavenge O(minusd)(2). Chemiluminescence generated by HOCl was also significantly and dose-dependently inhibited by both NIM and 4-OHNIM. Nevertheless, at each concentration tested, the inhibitory effect of 4-OHNIM was significantly more marked, even at the highest concentration (100 microM). Furthermore, when chondrocytes were pre-incubated for 48-96 h with NIM or 4-OHNIM, the luminol- and HRP-dependent CL produced by the cells was significantly inhibited in a dose-dependent manner. CONCLUSIONS: NIM and 4-OHNIM may protect cartilage against oxidative stress, not only by scavenging ROS but also by inhibiting their production by chondrocytes.

Basic fibroblast growth factor up-regulates the expression of vascular endothelial growth factor in primary cultured rat astrocytes.

AIM: To examine the effect of recombinant human basic fibroblast growth factor (bFGF) on the expression of vascular endothelial growth factor (VEGF) in primary cultured rat astrocytes. METHODS: Semiquantification PCR (SQ-PCR) and immunocytochemistry were used to investigate the effect of bFGF on VEGF mRNA level and protein level, respectively. RESULTS: Treatment with bFGF dose-dependently increased the VEGF mRNA level in astrocytes. The up-regulation of VEGF mRNA induced by bFGF (10 micrograms/L) was detected as short as 3-h treatment. The increase of VEGF mRNA level reached the maximum after 24-h treatment with bFGF. The immunocytochemical staining showed that the VEGF protein level in astrocytes also increased after the cells were incubated with bFGF. CONCLUSION: bFGF induced a marked time- and concentration-dependent increase in VEGF expression in primary cultured astrocytes, suggesting that the effect of bFGF on angiogenesis in brain may act partly by up-regulating VEGF expression in astrocytes.

Bilobalide promotes expression of glial cell line-derived neurotrophic factor and vascular endothelial growth factor in rat astrocytes.

AIM: To study the effects of bilobalide on the expression of glial cell line-derived neurotrophic factor (GDNF) and vascular endothelial growth factor (VEGF) in rat astrocytes in vitro. METHODS: Semiquantification polymerase chain reaction (SQ-PCR) was used to investigate GDNF and VEGF mRNA expression in the astrocytes after bilobalide (5, 15, 50, 100 mumol.L-1) treatment. Immunohistochemistry method was used to detect GDNF and VEGF protein expression in cells treated with bilobalide 50 mumol.L-1 for 24 h. RESULTS: GDNF and VEGF mRNA increased markedly after astrocytes were treated with bilobalide 50 mumol.L-1 for 12 h. GDNF and VEGF protein were detected in the cytoplasm of astrocytes after the cells were treated with bilobalide 50 mumol.L-1 for 24 h. CONCLUSION: Bilobalide induced GDNF and VEGF expression in the cultured astrocytes.

In vitro study of the antioxidant properties of non steroidal anti-inflammatory drugs by chemiluminescence and electron spin resonance (ESR).

OBJECTIVES: To determine the antioxidant activities of nonsteroidal anti-inflammatory drugs (NSAIDS), we examined by chemiluminescence (CL) and electron spin resonance (ESR) their scavenging properties towards lipid peroxides, hypochlorous acid and peroxynitrite. METHODS: The antioxidant properties of nimesulide (NIM), 4-hydroxynimesulide (4-HONIM), aceclofenac (ACLO), 4-hydroxyaceclofenac (4-HOA-CLO), diclofenac (DICLO) and indomethacin (INDO) were tested on four different reactive oxygen species (ROS) generating systems: (I) phorbol-myristate acetate (PMA)-activated neutrophils, (II) Fe2+/ascorbate-induced lipid peroxidation, (III) HOCl-induced light emission, (IV) the kinetics of ONOO- decomposition followed by spectrophotometry. ROS production was monitored by luminol-enhanced CL or by ESR using two different spin traps. RESULTS: At 10 microM, ACLO, NIM, 4-HONIM, 4-HOA-CLO, and DICLO decreased luminol-enhanced CL generated by PMA-activated neutrophils. Inversely, INDO increased the luminol enhanced CL. Interestingly, hydroxylated metabolites were more potent antioxidants than the parent drugs. Furthermore, all drugs tested, excepted ACLO, lowered lipid peroxidation induced by Fe2+/ascorbate system. ACLO and DICLO, even at the highest concentration tested (100 microM), did not significantly lower HOCl induced CL, whereas the other drugs were potent scavengers. Finally, all the NSAIDS accelerated decomposition of ONOO-, suggesting a potential capacity of the molecules to scavenge peroxynitrite. CONCLUSION: The NSAIDs possess variable degrees of antioxidant activities, linked to their ability to react with HOCl, lipid peroxides or ONOO-. These antioxidant activities could offer interesting targeted side-effects in the treatment of joint inflammatory diseases.

[A study of effects of head-down bed-rest simulated weightlessness on phonetic features of Chinese].

OBJECTIVE: To study the changes of phonetic features of Chinese speech during head-down bed-rest (HDBR) simulated weightlessness. METHOD: During -6 degrees HDBR in 6 healthy subjects (20-30 years), acoustic-phonetic features were analyzed. RESULT: The duration of utterance was slightly increase in the first two days, and recovered after the fourth day of HDBR; mean energy decreased along with time of bed rest, t-tests showed that the decrease in energy of utterances was very significant; a decrease in fundamental frequencies under HDBR was also significant. CONCLUSION: There were certain changes in the acoustic phonetic features under HDBR, some of them were significant.

Effects of sound preconditioning on hearing loss from low or middle-frequency noise exposure.

Objective. To explore prior noise exposures or sound conditioning as a moderator of hearing loss produced by traumatic exposure to low or middle-frequency noise. Method. Two experimental groups of guinea-pigs were conditioned using a 0.5 kHz octave band noise (OBN) at 85 dB, 6 h/d for 4 d. The subjects were allowed to recover for 3 d after conditioning. Then the first group was exposed to a 0.5 kHz OBN at 110 dB for 1 h, the second group was exposed to 1 kHz OBN at 110 dB for 1 h. Two control groups received 0.5 kHz and 1 kHz OBN respectively at 110 dB for 1 h without prior sound conditioning. Result. Hearing threshold shifts recorded at 48 h after the high-level noise exposure in conditioned groups and control groups demonstrated that conditioning provided significant protection on hearing threshold shift from low or middle frequency noise exposure. Histological examination revealed significantly less hair cell loss in the conditioned than in the control groups. In addition, malondialdehyde (MDA) levels in red blood cell (RBC) of conditioned groups were significantly lower as compared with that of the control groups. Conclusion. Low-frequency conditioning provided significant protection not only on hearing threshold shift caused by noise of the same frequency, but also on that caused by middle frequency noise.

Antisense oligodeoxynucleotide inhibits vascular endothelial growth factor in human glioma cells.

AIM: To study the effects of antisense vascular endothelial growth factor (VEGF) oligodeoxynucleotide (ODN) on the expression of VEGF in human glioma cell line (A172 cells). METHODS: VEGF mRNA level was measured by semiquantification reverse transcriptase polymerase chain reaction (RTPCR). VEGF protein expression in the cells was determined by immunohistochemistry. VEGF protein level in the media was measured by ELISA. RESULTS: When the cells were treated with antisense VEGF ODN (6.25-50 mumol.L-1), VEGF mRNA level in the cells decreased remarkably in a concentration-dependent manner. No change was found when the cells were treated with sense or missense ODN. When the cells were treated with antisense VEGF ODN 25 mumol.L-1, VEGF protein level decreased greatly both in the cells and the media. CONCLUSIONS: Antisense VEGF ODN inhibited VEGF expression specifically in A172 cells in vitro and thus the results provided the basis for the further studies in vivo.

Amyloid-beta 25-35 peptide induces expression of monoamine oxidase B in cultured rat astrocytes.

AIM: To investigate the effects of amyloid-beta 25-35 peptide (A beta 25-35) on monoamine oxidase (MAO) expression and activity in primary cultured rat astrocytes. METHODS: Immunocytochemistry was used to observe the morphological changes in astrocytes. Fluorescence spectrophotometry was used to measure the activity of MAO in astrocytes. The expression of MAO in astrocytes was assayed by RT-PCR. RESULTS: A beta 25-35 induced a reactive morphological change in cultured rat astrocytes which was accompanied by increased immunoreactivities for glial fibrillary acidic protein. Treatment with A beta 25-35 resulted in an elevation of MAO activity in a dose- and time-dependent manner. A beta 25-35-induced enhancement of MAO activity was of type B (MAO-B). The increase in MAO-B activity appeared to be due to an increase in the number of enzyme molecules since kinetic analysis demonstrated a 1.5 fold increase in Vmax with no change in Km. Treatment with A beta 25-35 also led to a substantial increase in MAO-B mRNA level in the astrocytes. CONCLUSION: A beta 25-35 is able to selectively induce MAO-B expression in rat astrocytes and that the upregulation of MAO-B in A beta 25-35-stimulated astrocytes may play an important role in the pathogenesis of Alzheimer's disease.

[Insect-resistant transgenic plants of Brassica napus and analysis of resistance in the plants].

Cotyledons, each with a 1-2 mm petiole at its base, were cut from axenic seedlings and infected with Agrobacterium tumefaciens. After 2-3 days of cocultivation, the cotyledon explants were transferred to MS selection medium containing 15 mg/L kanamycin and 4.5 mg/L 6-BA to induce shoot differentiation. Kanamycin-resistant shoots were subcultured on selection medium with 20-50 mg/L kanamycin for 3-6 months for eliminating escaped non-transformants, and then rooted on MS medium containing 25 mg/L kanamycin and 0.1 mg/L NAA. Whole plants were transplanted into soil and grew in the field. DNA Southern blot hybridization and polymerase chain reaction showed that some of the plants were positive when probed with the insecticidal crystal protein gene. The transgenic plants exhibited tolerant to pest insects such as Laphygma exigua and Pieris rapae in leaf feeding experiments Kanamycin-resistance and insect-resistance were maintained in the progeny. The foreign genes were delivered to the progeny according to Mendelian Law of single gene segregation.

High prevalence of low femoral bone mineral density in elderly women living in nursing homes or community-dwelling: a plausible role of increased parathyroid hormone secretion.

The present study was designed to visit elderly women living in nursing homes and to compare their femoral neck bone mineral density (BMD) and circulating levels of parathyroid hormone (PTH) and 25-OH vitamin D (25-OHD) with those of subjects living at home, in the immediate vicinity of the nursing homes. Of 1483 women, aged 70 years and older, who were selected, 993 agreed to participate in this trial. Their femoral neck BMD (n = 993) was measured by dual-energy X-ray absorptiometry, with a specific device installed in a mobile truck. The circulating levels of 25-OHD and PTH were assessed after an overnight fast (n = 748). After stratification for age, there were no significant differences in mean femoral neck BMD values, prevalence of femoral neck osteoporosis, mean serum 25-OHD and prevalence of absolute or relative 25-OHD deficiency between the two groups. Serum levels of PTH were significantly higher in women over 80 years old living in nursing homes, compared with the community-dwelling women. After adjustment for age, a significant relation was found between femoral neck BMD and PTH levels in the whole population (p = 0.004) and in community-dwelling subjects (p = 0.039). When stratifying our population by quartiles of serum PTH values, the odds ratios for femoral neck osteoporosis were significantly increased for the top two quartiles compared with the lowest one both before (p = 0.00146) and after (p = 0.0013) adjustment for age and type of housing. From this study we conclude that femoral osteoporosis is largely underestimated in European women. Living in a nursing home is not, per se, a risk factor for decreased femoral BMD, and circulating PTH levels are a key determinant of low femoral bone density and osteoporosis.

Effects of nimesulide and sodium diclofenac on interleukin-6, interleukin-8, proteoglycans and prostaglandin E2 production by human articular chondrocytes in vitro.

OBJECTIVES: The aim of this study was to investigate the effects of two nonsteroidal anti-inflammatory drugs (NSAIDs), nimesulide and sodium diclofenac, on the production of proteoglycans (PG), prostaglandin E2 (PGE2) and cytokines (IL-6 and IL-8) by human articular chondrocytes in vitro. METHODS: Enzymatically isolated chondrocytes were cultured under constant agitation in a well defined culture medium. Specific radioimmunoassays were used to quantify PG and PGE2 production. Cytokine production (IL-6 and IL-8) was assayed by enzyme amplified sensitivity immunoassays (EASIAs). RESULTS: At a concentration of 3 micrograms/ml, nimesulide did not affect the PG production by chondrocytes. This concentration was superior to the highest level of nimesulide found in the synovial fluid of patients with rheumatoid arthritis 3 hours after the last oral administration of nimesulide (100 mg twice daily for 7 days). At 6 micrograms/ml a significant reduction in the PG content was obtained in the cellular phase in 5 out of the 8 cultures investigated. No similar effect was observed in the culture supernatants. Above this concentration nimesulide inhibited PG production in a dose-dependent manner. At concentrations ranging from 0.005 to 1 microgram/ml diclofenac did not significantly alter PG production. At therapeutic concentrations PGE2 production was totally inhibited by nimesulide, thus suggesting that PG inhibition is not linked to PGE2 production. Nimesulide inhibited PGE2 production by unstimulated (IC50 = 6 ng/ml) and IL-1 beta-stimulated (IC50 = 6.9 ng/ml) chondrocytes. At these concentrations, PGE2 production was fully inhibited by diclofenac. Furthermore, both nimesulide and diclofenac at therapeutic concentrations significantly decreased spontaneous and IL-1 beta-stimulated IL-6 production by human chondrocytes, but did not modify IL-8 production. CONCLUSION: From the results of this study we conclude that nimesulide and diclofenac at therapeutic concentrations are potent inhibitors of PGE2 and IL-6 production while they do not modify proteoglycan or IL-8 production.

Characterization of the inhibitory effect of boiled rice on intestinal chloride secretion in guinea pig crypt cells.

BACKGROUND & AIMS: When rice is incorporated into oral rehydration therapy for patients with secretory diarrhea, clinical outcomes improve. We have shown that a factor purified from boiled rice (RF) blocks the secretory response of intestinal crypt cells to adenosine 3',5'-cyclic monophosphate (cAMP). Now we report that the cystic fibrosis transmembrane conductance regulator (CFTR) chloride channel is the cellular target for this rice inhibitor. METHODS: We used RF, the same previously described extract prepared from boiled rice, to assess chloride channel activation in vitro, measuring (1) cell volume regulation of guinea pig intestinal crypt epithelial cell suspensions using standard Coulter counter technology, (2) transepithelial chloride current in monolayers of T84 cells mounted in Ussing chambers, and (3) whole-cell and single-channel currents using the patch-clamp technique in cells transfected to express CFTR. RESULTS: RF inhibited activation by cAMP of CFTR chloride channels in all experimental preparations; RF did not block volume-stimulated Cl- secretion, suggesting that its effect might be specific for CFTR chloride channels. RF inhibited transepithelial cAMP-stimulated Cl- current in T84 cells and inhibited forskolin (i.e., cAMP)-induced current in cells transfected with CFTR. Excised patch and single-channel patch-clamp recordings supported the view that the response was a direct effect on CFTR rather than on cAMP signal transduction. CONCLUSIONS: RF exerts a specific inhibitory effect on CFTR chloride channels, blocking activation from the luminal surface of the cell and reversing established activation. Many major diarrheal states are based on cAMP-induced CFTR activation, leading to excessive gut secretion; our findings could have clinical relevance.

Non-pore lining amino acid side chains influence anion selectivity of the human CFTR Cl- channel expressed in mammalian cell lines.

1. The effects of individually mutating two adjacent threonine residues in the sixth membrane-spanning region (TM6) of the cystic fibrosis transmembrane conductance regulator (CFTR) Cl- channel on permeation properties were examined using patch clamp recording from mammalian cell lines stably expressing human CFTR. 2. A number of mutations of T338 significantly affected the permeation properties of the channel. Increases and decreases in single channel conductance were observed for different mutants. Anion selectivity was strongly affected, with no two channel variants sharing the same selectivity sequence. Several mutations led to strong inward rectification of the macroscopic current-voltage relationship. The effects of these mutations on permeation properties were correlated with the size of the amino acid side chain substituted, rather than its chemical nature. 3. Most mutations of T339 resulted in a lack of functional channel expression and apparent misprocessing of the protein. One mutant, T339V, was characterized in detail; its permeation properties were significantly altered, although these effects were not as strong as for T338 mutations. 4. These results suggest an important role for T338 in controlling the permeation properties of the CFTR Cl- channel. It is suggested that mutation of this residue alters the interaction between permeating anions and the channel pore via an indirect effect on the orientation of the TM6 helix.