[Comparison of ultrathin bronchoscopy with conventional bronchoscopy for the diagnostic value of peripheral pulmonary lesions]

Objective: To assess and compare the diagnostic efficacy of next-generation ultrathin bronchoscopy (UTB) and conventional bronchoscopy (CB), both combined with radial endobronchial ultrasound (r-EBUS), in the evaluation of peripheral pulmonary lesions (PPL). Methods: A cohort of 39 patients with PPL who underwent multimodal bronchoscopy at Dushu Lake Hospital, Soochow University, from June 1, 2021 to May 31, 2023 was consecutively enrolled. A single bronchoscopist performed multimodal bronchoscopies using CB (external diameter 4.9 mm or 5.9 mm, working channel diameter 2 or 3 mm, CB group) for transbronchial biopsy under r-EBUS guidance (rEBUS-TBLB), followed by UTB (external diameter 3 mm, working channel diameter 1.7 mm, UTB group) for transbronchial biopsy under r-EBUS guidance. Pathological findings and a 6-month clinical follow-up were used as the gold standard to compare the diagnostic yield of biopsy specimens, ultrasound characteristics, and localization rates of the two bronchoscope types. The aim was to evaluate the clinical application value of UTB combined with r-EBUS. Binary variables were analysed using the McNemar test for paired data. Continuous variables or ranked data were analysed using the Wilcoxon signed-rank test for paired data. Results: The diagnostic yields for UTB and CB groups were 66.67% (26/39) and 30.77% (12/39), respectively, with the UTB group significantly surpassing the CB group (χ2=10.56, P=0.001, 1-β=0.968). r-EBUS with CB exhibited no visible lesion in 13 cases, adjacent to the lesion in 19 cases, and within the lesion in 7 cases.Substitution of UTB resulted in r-EBUS images changing from no visible lesion to adjacent to the lesion in 7 cases, from no visible lesion to within the lesion in 3 cases, and from adjacent to the lesion to within the lesion in 12 cases. The positioning of the r-EBUS probe in relation to the lesions improved significantly with UTB usage (Z=-4.46, P<0.001). Localization rates (number of patients with "within" or "adjacent to" the image/total number of patients) for UTB and CB were 92.30% (36/39) and 66.67% (26/39), respectively (χ2=8.10, P=0.002). UTB improved r-EBUS probe localization rates. The diagnostic yields of UTB were higher than CB for solid lesions, lesions>30 mm in diameter, non-upper lobar location, benign or malignant lesions and lesions with or without a bronchus sign. Conclusion: The UTB group demonstrated a significantly higher diagnostic yield than the CB group, providing superior r-EBUS probe images, and a significant diagnostic advantage for PPL.

[Role of crenel lateral lumbar interbody fusion in the precise selection of fusion level in posterior correction for adult degenerative scoliosis]

Objective: To investigate the role of minimally invasive crenel lateral lumbar interbody fusion (CLIF) in the decision of fusion level in posterior correction for severe adult degenerative scoliosis. Methods: This is prospective study.Patients with level Ⅴ and Ⅵ of Lenke-Silva classification who were treated in department of spine surgery,orthopedics center,the Second Affiliated Hospital, School of Medicine, Zhejiang University from June 2016 to March 2019 were included.First,the enrolled patients completed the preoperative clinical and imaging examination,the Lenke-Silva classification was evaluated,the surgical segments in first-stage CLIF was determined and the fusion segments required for single-stage posterior correction was predicted.After the first-stage CLIF,patients received reassessment of Lenke-Silva classification and global coronal and sagittal balance.Patients were divided into two groups:the effective group (level of Lenke-Silva classification decreased) and the ineffective group (level of Lenke-Silva classification unchanged).Second-stage posterior surgery was performed based on the results of reassessments.The fusion segment,Cobb angle,parameters of global coronal and sagittal plane,visual analogue pain score (VAS) and Oswestry disability index (ODI) were compared between the two groups preoperatively,after first-stage CLIF,second-stage posterior fixation and at the final follow-up.The potential factors associated with the decrease of the level of Lenke-Silva classification were recorded and compared between the two groups.Independent sample t test,repeated measure analysis of variance,rank sum test,χ² test or Fisher exact method were used to compare the difference among groups. Results: Fifty-four patients were enrolled,including 8 males and 46 females,aged (68.8±5.8) years (range:56 to 77 years).Preoperatively,26 patients were classified as level Ⅴ by Lenke-Silva classification,28 cases were grade Ⅵ.CLIF was performed in 194 segments,with 114 (58.8%) segments receiving anterior column realignment (ACR) and 15 (7.7%) segments using hyperlordotic cages.After first-stage CLIF,22 patients with level Ⅴ and 10 patients with Ⅵ of Lenke-Silva classification decreased and were classified into effective group.The level of the remaining 4 patients with level Ⅴ and 18 patients with grade Ⅵ unchanged and were classified into ineffective group.Preoperatively,the apical vertebrae was below L₁ in all 32 patients of effective group and 18 (81.8%,18/22) patients of ineffective group.The difference was statistically significant (P=0.023).There were 7 (31.8%,7/22) patients had continuous osteophyte in front of the intervertebral space in ineffective group,while none patient had continuous osteophyte in front of the intervertebral space in effective group,and the difference was statistically significant (P=0.001).In first-stage CLIF,more intraoperative ACR(71.2% vs.39.5%,χ²=20.66,P<0.01)and hyperlordotic cage (12.7$ vs.0,P=0.001)were used in the effective group,while there was less severe cage subsidence after the operation (5.9% vs.15.8%,χ²=4.793,P=0.029) in effective group.After first-stage CLIF,there was no difference in the Cobb angle between the two groups.While,lumbar lordosis (LL) in effective group (34.0±8.3)° was greater than that of the ineffective group (25.5±9.7)° (t=3.478,P=0.001),and the difference between the pelvic incidence (PI) and LL in effective group (15.7±4.6)°was significantly smaller than ineffective group(20.0±10.8)° (t=-2.129,P=0.038).The posterior fusion levels was less,the rate of fusion to thoracic spine region and the actual fusion segment was less than that of single-stage posterior correction in effective group (all P<0.01).All patients were follow-up for 24 to 45 months.There was no significant difference in radiological and clinical results between the two groups after first-,second-stage surgery and at the final follow-up (all P>0.05). Conclusions: First-stage CLIF decreased the Lenke-Silva classification of some patients with severe degenerative scoliosis.Combined with the reassessment of Lenke-Silva classification and global coronal and sagittal plane,it helps to accurately determine the fusion segment.Decrease of Lenke-Silva classification was associated with the preoperative level of apical vertebrae,continuous osteophytes in front of the intervertebral space,intraoperative use of ACR and hyperlordotic cage and the degree of cage subsidence postoperatively.

[Minimally invasive surgery for the severe degenerative lumbar scoliosis: two stage protocol]

Objective: To investigate the surgical outcome of minimally invasive surgery(MIS) for severe degenerative lumbar scoliosis(DLS) and put forward a two-stage MIS surgical strategy. Methods: Prospective study of MISDEF Ⅲ DLS patients from June 2016 to August 2017 in the Second Affiliated Hospital of Zhejiang University was carried out, excluding the patients whose apex vertebrae of scoliosis was above L(1/2) level or whose facet joint got spontaneous fusion. Fifty-three patients were included in this study for staging evaluation and MIS surgical treatment. Information was recorded, including gender, age, body mass index, follow-up period, pelvic incidence (PI), blood loss, operation time, visual analogue pain score (VAS), Oswestry disability index (ODI), complications in the perioperative period and follow-up period, and also the radiographic parameters such as scoliosis Cobb angle, the mismatch between pelvic incidence and lumbar lordosis (PI-LL), sagittalvertical axis (SVA), coronal balance (CB) before and after each stage of surgery or latest follow-up. The paired-samples t test was used to analyze the effectiveness of staging surgery. Results: Fifty-three patients (18 males and 35 females) were included in this study. All patients had completed clinical and the follow-up records, with an average follow-up period of 11.52 months (6-20 months). A total of 168 segments fusions were performed with CLIF, 113 segments were performed with anterior column realignment (ACR), the average correct angle was 15.6°±6.3°(7°-28°) in sagittal plane each level. After the stage Ⅰ surgery, lumbar scoliosis cobb had been corrected for 55.35%, after the stage Ⅱ surgery, rate of correction was 75.6%. PI-LL had been matched (-32.8°±14.9° to -2.5°±9.4°), SVA was changed from 5.7 cm to 0.6 cm, the stage Ⅰ rate of correction was 80.3 and stage Ⅱ was 88.8%, pelvic tilt (PT), lumbar lordosis (LL) and CB had been restored; 13 (24.5%) patients were performed paraspinal approach transforaminal decompression. The posterior minimally invasive fixation indexes: 11(20.8%) patients were performed paraspinal approach transforaminal multi-segment transforaminal osteotomy (TFO) and internal fixation; 36(67.92%) cases were performed paraspinal approach transforaminal multi-segment fixation; 6(11.33%) patients were treated with percutaneous pedicle screw fixation. The average fixed segments was 7.4±1.4 in each patient. The blood loss of stage Ⅰ and stage Ⅱ operation was (157±71) ml, (343±224)ml, respectively. The operation time was (214±60) min, (190±54)min respectively in the two stage operations. The low back pain and leg pain VAS score and ODI improved after the stage Ⅰ and Ⅱ surgery (t=17.948, 10.099, 14.619, all P<0.001). Conclusions: MIS for the severe degenerative lumbar scoliosis can achieve good clinical outcome and deformity correction. The two-stage protocol has the advantages of less complications and is well-tolerated.

[A study on effects of immediate bone grafting at mandibular first molar fresh extraction socket on maintaining alveolar bone height after space closure]

Objective: To investigate the effect of immediate bone grafting at mandibular first molar extraction socket on maintaining alveolar bone height after space closure. Methods: Thirty adult orthodontic patients who need to extract mandibular first molar, totally 38 target teeth, were included. The samples were divided into two groups randomly: graft group and non-graft group. All extraction space was closed orthodontically. Dental models of all patients were taken before extraction (T0), before space closure(T1) and after space closure (T2). The distance, time of the space closure and the velocity of tooth movement were recorded. Probing depth (PD) and clinical attachment level (CAL) at six sites (mesial buccal, buccal, mesial lingual, lingual, distal buccal and distal lingual) on adjacent teeth were measured before extraction (T0) and after space closure (T2). Cone-beam CT (CBCT) was taken at T0 and T2 to compare the changes of alveolar bone height at six sites on adjacent teeth using Invivo Dental 5.0 software. Results: The extraction space in both graft group and non-graft group was closed successfully. However, the space in graft group was closed more slowly than in non-graft group. In graft group, PD and CAL at the six sites on both the second molar and the second premolar did not change significantly after space closure, and CBCT showed that the alveolar bone height of the second premolar had no significant difference after treatment. In non-graft group, alveolar bone height decreased in both adjacent teeth and periodontal attachment loss was found after space closure. On average, alveolar bone height and periodontal attachment of the second premolar decreased (0.75±0.16) mm and (0.64±0.15) mm, respectively. Meanwhile, alveolar bone height and periodontal attachment of the second molar decreased (0.79±0.23) mm and (0.80±0.24) mm, respectively. Conclusions: Bone graft immediately after mandibular first molar extraction could delay alveolar bone resorption and preserve the periodontal attachment of the adjacent teeth during space closure. However, the procedure could slow down tooth movement.

Curative effect and costs of surgical and gamma knife treatments on intractable epilepsy caused by temporal-hippocampal sclerosis

This study aimed to investigate the curative effect and costs of surgical and gamma knife treatments on intractable epilepsy caused by temporal-hippocampal sclerosis. The subjects comprised patients who suffered from intractable epilepsy caused by temporal-hippocampal sclerosis and received treatment in the Department of Neurosurgery of our hospital between 2010 and 2011. After obtaining their consent, patients were evaluated and selected to receive surgical or gamma knife treatments. In the surgical group, the short-term curative rate was 92.60% and the average cost was US$ 1311.50 while in the gamma knife group, the short-term curative rate was 53.79%, and the average cost was US$ 2786.90. Both surgical and gamma knife treatments of intractable epilepsy caused by temporal-hippocampal sclerosis are safe and effective, but the short-term curative effect of surgical treatment is better than that of gamma knife, and its cost is lower.

Adjacent SNPs in the transcriptional regulatory region of the FADS2 gene associated with fatty acid and growth traits in chickens

Delta-6 fatty acid desaturases are rate-limiting desaturases involved in metabolic processes of fatty acids, and they are encoded by the FADS2 gene. In the current study, an F2 resource population of Gushi chickens crossed with Anak broilers was used to investigate the genetic effects of the chicken FADS2. Two adjacent single nucleotide polymorphisms (SNPs) (g.4290C>G and g.4291C>A) were identified in the transcriptional regulatory region of the FADS2 gene by means of polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and created restriction site-PCR-RFLP. Associations between the two SNPs with chicken fatty acid contents and growth traits were determined using linkage disequilibrium, haplotype construction, and association analysis. The two SNPs and their haplotype combinations were significantly associated with linoleic acid (C18:2), α-linolenic acid (C18:3), arachidonic acid (C20:4), body weight (BW)2, BW4, BW6, shank girth (SG)4, and breast bone length 4 (P<0.05). These results suggested that the SNPs of the FADS2 gene affected the content of essential fatty acid in muscle, and played a role in the early-stage growth rate of chickens.

Dual delivery for stem cell differentiation using dexamethasone and bFGF in/on polymeric microspheres as a cell carrier for nucleus pulposus regeneration

This study aimed to investigate the feasibility of the nanostructured 3D poly(lactide-co-glycolide) (PLGA) constructs, which are loaded with dexamethasone (DEX) and growth factor embedded heparin/poly(L-lysine) nanoparticles via a layer-by-layer system, to serve as an effective scaffold for nucleus pulposus (NP) tissue engineering. Our results demonstrated that the microsphere constructs were capable of simultaneously releasing basic fibroblast growth factor and DEX with approximately zero order kinetics. The dual bead microspheres showed no cytotoxicity, and promoted the proliferation of the rat mesenchymal stem cells (rMSCs) by lactate dehydrogenase assay and CCK-8 assay. After 4 weeks of cultivation in vitro, the rMSCs-scaffold hybrids contained significantly higher levels of sulfated GAG/DNA and collagen type II than the control samples. Moreover, quantitative real time PCR analysis revealed that the expression of disc-matrix proteins including collagen type II, aggrecan, and versican in the rMSCs-scaffold hybrids was significantly higher than that in the control group, whereas the expression of osteogenic differentiation marker (collagen type I) was decreased. Taken together, these data indicate that Dex/bFGF PLGA microspheres could be used as a scaffold to improve the rMSCs growth and differentiating into NP like cells, and reduce the inflammatory response for IVD tissue engineering.

MMP2 promoter polymorphism (C-1306T) and risk of recurrence in patients with hepatocellular carcinoma after transplantation

Genetic variants in matrix metalloproteinase (MMP) gene may influence the biological function of these enzymes and change their role in carcinogenesis and progression. The effect of MMP2 C-1306T and MMP9 C-1562T polymorphisms on genetic susceptibility has been investigated in various kinds of cancer. However, the relationship between these polymorphisms and risk of recurrence of hepatocellular carcinoma (HCC) after liver transplantation (LT) has not been reported. The present study was designed to investigate the association of these two loci with the risk of HCC recurrence in 93 HCC patients treated with LT. Genotyping was performed using direct DNA sequencing. For MMP2 C-1306T variant, patients with CT heterozygous conferred a 58% reduction in recurrence risk (risk ratio: 0.419; 95% confidence interval: 0.177-0.994). The mean recurrence-free survival for CT genotype was significantly longer than that for homozygous CC patients (30.4 vs 19.3 months, p = 0.019). However, no association was found between MMP9 C-1562T polymorphisms and recurrence of HCC (p = 0.259). These findings suggest that MMP2 promoter polymorphisms may provide some predictive value for HCC recurrence after LT.

Kinetics of complexing activation by the magnesium ion on green crab (Scylla serrata) alkaline phosphatase

As with mammalian enzymes, green crab (Scylla serrata) alkaline phosphatase can be activated by Mg2+ through a time-dependent course. The activation is mainly a Vmax effect. Tsou's method was used to study the kinetic course of activation. The results show that the enzyme was activated by a complexing scheme that had not been previously identified: the enzyme first reversibly and quickly binds Mg2+ and then undergoes a slow reversible course to activation, with a relatively high activation energy (78 +/- 4 kJ/mol) and a slow conformational change. The activation reaction is a single molecule reaction, and the apparent activation rate constant is independent of Mg2+ concentration if the concentration is sufficiently high. The microscopic rate constants of activation and the association constant were determined from the measurements. The proposed scheme may also be applied to the Mg2+ activation mechanism for mammalian enzyme, to explain why the activation rate is time-dependent and not diffusion controlled. Substrate binding was also shown to affect the activation rate constant.

In vitro spontaneous parthenogenetic activation of golden hamster oocytes

Parthenogenetic activation is a major hurdle to be cleared for the examination of the human sperm chromosome after intracytoplasmic injection (ICSI) into golden hamster oocytes. Various factors that affect spontaneous activation of hamster oocytes were, therefore, investigated in this study. We collected cumulus-oocyte complexes (COC) from the oviducts of superovulated females and washed them thoroughly with Ca2+-containing or Ca2+-free TALP-HEPES medium (handling media). We cultured oocytes with intact cumulus or those without cumulus (removed by previous hyaluronidase treatment) in Ca2+-containing or -free m-TALP-3 for 6 or 12 h before examining for their activation. Among the oocytes recovered 17 h post-hCG, 92-94% were parthenogenetically activated by 6 h of in vitro culture. Activation rate in the oocytes collected at 13.5 h post-hCG (53%) was significantly (P < 0.05) lower than that in the oocytes collected 17 h post-hCG (92%), indicating that the spontaneous activation rate increased as the oocytes became older. Both cumulus-intact and cumulus-free oocytes had similar (P > 0.05) activation rates when cultured in vitro, suggesting that hyaluronidase treatment had no effect on the rate of oocyte activation. Omission of Ca2+ from the handling medium also had no effect on the activation of the oocytes. The rate of spontaneous activation of the oocytes cultured in calcium-free medium for 6 (9%) and 12 h (16%) was significantly (P < 0.01) lower than that (94%) of the control oocytes cultured in Ca2+-containing medium, implying a positive influence of Ca2+ on in vitro activation of hamster oocytes. When we cultured the oocytes first in calcium-free medium for 6 h, and then in calcium-containing medium for 6 h, 94% were activated, which is comparable to the rate for oocytes continuously cultured in Ca2+-containing medium. This indicates that the inhibition of hamster oocyte activation in Ca2+-free medium is reversible and can be used to control spontaneous activation of golden hamster oocytes.

Axillary osmidrosis treated by partial removal of the skin and subcutaneous tissue en bloc and apocrine gland subcision

BACKGROUND

Axillary osmidrosis can be treated with many methods, but local surgery is the treatment of choice.

METHODS

Forty-three patients (32 females and 11 males, average age 20.3 years) were treated by partial removal of the skin and subcutaneous tissue en bloc and follicular clipping of the adjacent area. All operations were performed with local anesthesia in an outpatient setting.

RESULTS

Follow-up ranged from 2 to 47 months (mean: 13.4 months). Forty-one patients (95%) had good results, two (5%) were fair, and none were poor. No recurrences were seen. The wound complication rate was 3.5% for axillae and 7% for patients. There were no scar contractures or limitations of arm abduction.

CONCLUSION

This combined surgical method can eliminate malodor and has a low wound complication and recurrence rate. Though the transient and conspicuous scar is the chief drawback of this method, it is a simple, safe, effective and inexpensive method for treating axillary osmidrosis.

[Exogenous pGH gene localization on chromosomes of the transgenic pigs]

The pUC19-OMT plasmids were cut by Ssp 1 and the products in 900 bp were recovered from low-melting agarose gel and used as probes which were labeled by Digoxigenin. After being denatured, the probes were dropped on the chromosome samples which were also denatured to anneal with them. The anti-digoxigenin antibodies labeled with colloidal gold were used to act with the chromosome samples. In order to localize the exogenous pGH genes(porcine growth hormone gene) on chromosomes detected with optical microscope and improve the sensitivity, digoxigen gold signals are amplified by silver precipitation. After calculating the number of silver grains on every chromosome under the optical microscope, we analyzed the data with statistical methods. The results show that the integrating sites of exogenous pGH genes are very different among the positives. However, it is clear that the exogenous genes in one are always of the tendency to integrate in one specific site on a certain chromosome. These data are of great significance for studying the site-specific integration and the expression efficiency of exogenous genes in the future research.

Inhibition kinetics of green crab (Scylla serrata) alkaline phosphatase by zinc ions: a new type of complexing inhibition

The Tsou method was used to study the kinetic course of inactivation of green crab alkaline phosphatase by zinc ions. The results show that the enzyme was inactivated by a complexing scheme which has not been previously identified. The enzyme first reversibly and quickly binds Zn(2+) and then undergoes a slow reversible course to inactivation and slow conformational change. The inactivation reaction is a single molecule reaction and the apparent inactivation rate constant is for a saturated reaction being independent of Zn(2+) concentration if the concentration is sufficiently high. The microscopic rate constants of inactivation and the association constant were determined from the measurements.

Effects of oxodiperoxovanadate (V) complexes on the activity of green crab (Scylla serrata) alkaline phosphatase

Green crab (Scylla serrata) alkaline phosphatase (EC 3.1.3.1) is a metalloenzyme that catalyzes the nonspecific hydrolysis of phosphate monoesters. The effects of some pollutants in seawater on the activity of the enzyme will result in the loss of the biological function of the enzyme, which will affect the exuviating crab shell and threaten the survival of the animal. In the present paper, the effects of four oxodiperoxovanadate (V) complexes on the activity of green crab alkaline phosphatase have been studied. The results show that these vanadate derivatives can lead to reversible inactivation. The equilibrium constants for binding of inhibitors with the enzyme and/or the enzyme-substrate complexes have been determined. The results show that sodium (2,2;-bipyridine)oxodiperoxovanadate, pV(bipy), and potassium oxodiperoxo-(1,10-phenanthroline)vanadate, pV(phen), are competitive inhibitors, while potassium picolinato-oxodiperoxo-vanadate, pV(pic), and oxalato-oxodiperoxovanadate, pV(ox), are mixed-type inhibitors. These results suggest that pV(bipy) is a considerably more potent competitive inhibitor than pV(phen) and that the competitive inhibition effect of pV(pic) is stronger than that of pV(ox), but the non-competitive inhibition effect of pV(ox) is stronger than that of pV(pic).

Kinetics of inhibition of green crab (Scylla serrata) alkaline phosphatase by vanadate

Green crab (Scylla serrata) alkaline phosphatase is a metalloenzyme that catalyzes the nonspecific hydrolysis of phosphate monoesters. The kinetics of inhibition of the enzyme by vanadate has been studied. The time course of the hydrolysis of p-nitrophenyl phosphate catalyzed by the enzyme in the presence of different Na3VO4 concentrations showed that, at each Na3VO4 concentration, the rate decreased with increasing time until a straight line was approached, the slopes of the straight lines being the same for all concentrations. The results suggest that the inhibition of the enzyme by Na3VO4 is a slow, reversible reaction with fractional residual activity. The microscopic rate constants were determined for the reaction of the inhibitor with the enzyme. As compared with Na2HPO4 (Ki = 0.95 mM), Na2HAsO4 (Ki = 1.10 mM), and Na2WO4 (Ki = 1.55 mM), the results suggest that Na3VO4 (Ki = 0.135 mM) is a considerably more potent inhibitor than other inhibitors.

Effect of metal ions on the activity of green crab (Scylla serrata) alkaline phosphatase

Green crab (Scylla serrata) alkaline phosphatase (EC 3.1.3.1) is a metalloenzyme, which catalyzes the nonspecific hydrolysis of phosphate monoesters. The present paper deals with the study of the effect of some kinds of metal ions on the enzyme. The positive monovalent alkali metal ions (Li(+), Na(+) and K(+)) have no effect on the enzyme; positive bivalent alkaline-earth metal ions (Mg(2+), Ca(2+) and Ba(2+)) and transition metal ions (Mn(2+), Co(2+), Ni(2+) and Cd(2+)) activate the enzyme; heavy metal ions (Hg(2+), Ag(+), Bi(2+), Cu(2+) and Zn(2+)) inhibit the enzyme. The activation of magnesium ion on the enzyme appears to be a partial noncompetitive type. The kinetic model has been set up and a new plot to determine the activation constant of Mg(2+) was put forward. From the plot, we can easily determine the activation constant (K(a)) value and the activation ratio of Mg(2+) on the enzyme. The inhibition effects of Cu(2+) and Hg(2+) on the enzyme are of noncompetitive type. The inhibition constants have been determined. The inhibition effect of Hg(2+) is stronger than that of Cu(2+).

Inhibition kinetics of green crab (Scylla serrata) alkaline phosphatase activity by dithiothreitol or 2-mercaptoethanol

Green crab (Scylla serrata) alkaline phosphatase (EC 3.1.3.1) is a metalloenzyme which catalyzes the nonspecific hydrolysis of phosphate monoesters. Some pollutants in seawater affect the enzyme activity causing loss of the biological function of the enzyme, which affects the exuviating crab-shell and threatens the survival of the animal. The present paper studies the effects of thiohydroxyal compounds on the activity of green crab alkaline phosphatase. The results show that thiohydroxyal compounds can lead to reversible inhibition. The equilibrium constants have been determined for dithiothreitol (DTT) and mercaptoethanol (ME) binding with the enzyme and/or the enzyme-substrate complexes. The results show that both DTT and ME are non-competitive inhibitors. The kinetics of enzyme inactivation by ME at low concentrations has been studied using the kinetic method of the substrate reaction. The results suggest that at pH 10.0, the action of ME on green crab ALP is first quick equilibrium binding and then slow inactivation. The microscopic rate constants were determined for inactivation and reactivation. The rate constant of the forward inactivation (k(+0)) is much larger than that of the reverse reactivation (k(-0)). Therefore, when the ME concentration is sufficiently large, the enzyme is completely inactivated.

Kinetics of inhibition of beta-glucosidase from Ampullarium crossean by bromoacetic acid

The kinetics of inhibition of beta-glucosidase from Ampullarium crossean by bromoacetic acid (BrAc) has been studied. The results show that the enzyme can be irreversibly and completely inactivated at high BrAc concentration, while at low BrAc concentration, inhibition of the enzyme is a slow, reversible reaction. The microscopic rate constants for the reactions of BrAc with the enzyme were determined. The presence of the substrate offers obvious protection of the enzyme against inhibition by BrAc. The above results suggest that the histidine residue is essential for activity and is situated at or near the active site of the enzyme.

Effect of methanol on the activity and conformation of acid phosphatase from the prawn Penaeus penicillatus

Prawn (Penaeus penicillatus) acid phosphatase (EC 3.1.3.2) catalyzes the nonspecific hydrolysis of phosphate monoesters. The effects of some pollutants in sea water on the enzyme activity results in the loss of the biological function of the enzyme, which leads to disruption of phosphate metabolism in cells. This paper analyzes the effects of methanol on the activity and conformation of prawn acid phosphatase. The results show that low concentrations of methanol can lead to reversible inactivation. Inhibition of the enzyme by methanol is classified as non-competitive inhibition, and the inhibition constant (Ki) is 8.5%. Conformational changes of the enzyme molecule in methanol solutions of different concentrations were measured using fluorescence emission, differential UV-absorption, and circular dichroism spectra. Increased methanol concentrations caused the fluorescence emission intensity of the enzyme to increase. The ultraviolet difference spectra of the enzyme denatured with methanol had two negative peaks, at 222 and 270 nm, and a positive peak at 236 nm. The changes in the fluorescence and ultraviolet difference spectra reflected the changes of the microenvironments of tryptophan and tyrosine residues of the enzyme. The CD spectrum changes of the enzyme show that the secondary structure of the enzyme also changed some. These results suggest that methanol is a non-competitive inhibitor and the conformational integrity of the enzyme is essential for its activity.

[A study of genetic character and foreign OMT/PGH gene integration in transgenic swine]

By using isotopic and non-isotopic in situ hybridization on chromosomes, the locus on chromosomes of foreign OMT/PGH gene was analyzed in eight transgenic pigs (G0, G1,G2 and G3). The research result is as follows: (1) The foreign genes could integrated on chromosomes of pig and the foreign integrated randomly; (2) the foreign genes integrated on chromosomes were transmissible through generations; (3) the locus on chromosomes of foreign gene was relatively stable in alternation of generations in transgenic swine.

Effect of ethanol on the activity and conformation of Penaeus penicillatus acid phosphatase

The effect of ethanol on the activity of Penaeus penicillatus acid phosphatase has been studied. The results show that ethanol significantly inhibits enzyme activity as a non-competitive inhibitor, with Ki 8.75%. The conformational changes of the enzyme molecule induced by ethanol were followed using fluorescence emission, ultraviolet difference and circular dichroism (CD) spectra. Increasing the ethanol concentration caused the fluorescence emission intensity of the enzyme to increase. The ultraviolet difference spectra of the enzyme denatured with ethanol had two negative peaks at 220 and 278 nm, and a positive peak at 240 nm. Increasing the ethanol concentration produced a small shoulder peak at 287 nm in addition to the increases in the negative magnitudes of the 220 and 278 nm peaks. The changes of the fluorescence and ultraviolet difference spectra reflected the changes of the microenvironments of the tryptophan and tyrosine residues of the enzyme. The CD spectrum changes of the enzyme show that the secondary structure of the enzyme also changed. The results suggest that ethanol is a non-competitive inhibitor and the conformational integrity of the enzyme is essential for its activity.

Kinetics of inhibition of green crab (Scylla serrata) alkaline phosphatase by sodium (2,2'-bipyridine) oxodiperoxovanadate

Green crab (Scylla serrata) alkaline phosphatase (EC 3.1.3.1) is a metalloenzyme, which catalyzes the nonspecific hydrolysis of phosphate monoesters. The kinetics of inhibition of the enzyme by sodium (2, 2'-bipyridine) oxodiperoxovanadate, pV(bipy), has been studied. The time course of the hydrolysis of p-nitrophenyl-phosphate catalyzed by the enzyme in the presence of different pV(bipy) concentrations showed that at each pV(bipy) concentration, the rate decreased with increasing time until a straight line was approached, the straight line slopes are the same for all concentrations. The results suggest that the inhibition of the enzyme by pV(bipy) is a slow, reversible reaction with fractional remaining activity. The microscopic rate constants are determined for the reaction of inhibitor with the enzyme.

Inhibitors of green crab (Scylla serrata) alkaline phosphatase

Green crab (Scylla serrata) alkaline phosphatase (EC 3.1.3.1) is a metalloenzyme which catalyzes the nonspecific hydrolysis of phosphate monoesters. The effects of several inhibitors on its activity have been studied. The results show that Na2HPO4, Na2HAsO4 and Na2WO4 are competitive inhibitors, L-phenylalanine is an uncompetitive inhibitor, while L-cysteine is a mixed-type inhibitor. The equilibrium constants were determined for inhibitor binding. The order of potency was Na2HPO4 (KI = 0.95 mM) > Na2AsO4 (1.10 mM) > Na2WO4 (1.55 mM).

Kinetics of inhibition of green crab (Scylla serrata) alkaline phosphatase by L-cysteine

The inhibition of alkaline phosphatase from green crab (Scylla serrata) by L-cysteine has been studied. The results show that L-cysteine gives a mixed-type inhibition. The progress-of-substrate-reaction method previously described by Tsou [(1988), Adv. Enzymol. Related Areas Mol. Biol. 61, 391-436] was used to study the inactivation kinetics of the enzyme by L-cysteine. The microscopic rate constants were determined for reaction of the inhibitor with the free enzyme and the enzyme-substrate complex (ES) The results show that inactivation of the enzyme by L-cysteine is a slow, reversible reaction. Comparison of the inactivation rate constants of free enzyme and ES suggests that the presence of the substrate offers marked protection of this enzyme against inactivation by L-cysteine.

An essential lysine residue of green crab (Scylla Serrata) alkaline phosphatase

The values of pKa (10.38) and Hion (10.92 Kcal/mol) have been determined for the ionizing groups controlling activity of green crab alkaline phosphatase. The results suggest that -NH2 of lysine residue responsible for the ionization with pKc = 10.38 and delta H(o)ion = 10.92 Kcal/mol is in the active site of the enzyme. Modification of lysine residues of the enzyme by an excess of 2,4,6-trinitrobenzenesulfonic acid leads to complete inactivation. The two results coincide with each other. Quantitative assessment of the data indicates that among the reactive -NH2 groups modified only one is essential for the activity of the enzyme.

Kinetics of inhibition of Penaeus penicillatus acid phosphatase by bromoacetic acid

The kinetics of inhibition of penaeus penicillatus acid phosphatase by bromoacetic acid has been studied. The results show that inhibition of the enzyme by bromoacetic acid is a slow, reversible reaction. The microscopic rate constants for the reaction of inhibitor with the enzyme were determined. The presence of the substrate offers marked protection of this enzyme against inhibition by bromoacetic acid. The above results suggest that the histidine residue is essential for activity and are situated at the active site of the enzyme.

Kinetics of inactivation of Penaeus penicillatus acid phosphatase during inhibition by N-bromosuccinimide

In the present investigation, the inactivation by N-bromosuccinimide of acid phosphatase from penaeus penicillatus has been studied using the kinetic method of the substrate reaction during modification of enzyme activity as previously described by Tsou [(1988, Adv. Enzymemol. Related Areas Mol. Biol. 61, 381-436]. The results show that inactivation of the enzyme by N-bromosuccinimide is a slow, reversible reaction. The results also clearly show that the modification of the tryptophan residues of penaeus penicillatus acid phosphatase by high concentrations of N-bromosuccinimide led to the complete inactivation of the enzyme. The microscopic rate constants were determined for the reaction of the inactivator with the free enzyme and with the enzyme-substrate complex. Comparison of the obtained microscopic rate constants indicates that the presence of the substrate offers marked protection of the enzyme against inactivation by N-bromosuccinimide. The above results suggest that the tryptophan residue is essential for activity and may be situated at the active site of the enzyme.

The effects of N-thiophosphoryl amino acids on the activity of green crab (Scylla Serrata) alkaline phosphatase

Green crab (Scylla Serrata) alkaline phosphatase (EC 3.1.3.1) is a metalloenzyme which catalyzed the nonspecific hydrolysis of phosphate monoesters. In the present paper, the effects of several N-thiophosphoryl amino acids on the activity of green crab alkaline phosphatase have been studied. The results show that these derivatives of amino acids can lead to reversible inactivation. The equilibrium constants for inhibitors binding with the enzyme and/or the enzyme-substrate complexes have been determined. The obtained results show that both N-thiophosphoryl-Cys and N-thiophosphoryl-Glu were non-competitive inhibitors, while other five N-thiophosphoryl amino acids were un-competitive inhibitors. For the un-competitive inhibitors, the inhibition strength follows the order N-thiophosphoryl-Ile > -Val > -Lys > -Ala > -Tyr. Compared with respective free amino acids, it can be seen that N-thiophosphorylation of the amino acids increased their inhibition strength except the N-thiophosphoryl-Cys.

Zn2+ blocks the NMDA- and Ca2+ -triggered postexposure current ipe in hippocampal pyramidal cells

Whole cell voltage-clamp recordings from acutely isolated hippocampal CA1 pyramidal cells from adult guinea pigs were used to evaluate divalent cations as possible blockers of the postexposure current (Ipe). Ipe is a cation current that is triggered by the rise in intracellular Ca2+ concentration that occurs after the application of a toxic level of N-methyl-D-aspartate (NMDA). Once triggered, Ipe continues to grow until death of the neuron occurs. Ipe may be a critical link between transient NMDA exposure and cell death. Ipe was blocked by micromolar concentrations of Zn2+. The Zn2+ effect had an IC50 of 64 microM and saturated at 500 microM. Prolonged Zn2+ block of Ipe revealed that the maintenance of a steady Ipe is not dependent on Ipe-mediated Ca2+ influx but that the continuous growth in Ipe is dependent on Ipe-mediated Ca2+ influx. The availability of an effective blocker of Ipe should facilitate the investigation of the intracellular activation pathway of Ipe and the role of Ipe in neuronal death.

Unfolding and inactivation of Penaeus penicillatus acid phosphatase during denaturation by guanidine hydrochloride

The conformational changes of penaeus penicillatus acid phosphatase during denaturation in guanidine hydrochloride solutions were studied by following changes in the intrinsic fluorescence, ultraviolet difference absorption, and circular dichroism spectra. Inactivation of the enzyme in guanidine hydrochloride solutions were compared with unfolding of the enzyme molecule. The results show that the extent of unfolding in guanidine solutions measured by several different methods closely coincide with each other and that slightly lower concentrations of guanidine are required to bring about inactivation than are required to produce significant conformational changes of the enzyme molecule. At the same concentrations, the inactivation rate constants are markedly faster than the rate constants for unfolding of the enzyme. The above results suggest that the active sites of this enzyme display more conformational flexibility than the enzyme molecule as a whole.

Secondary activation of a cation conductance is responsible for NMDA toxicity in acutely isolated hippocampal neurons

One of the key questions concerning glutamate toxicity is how a transient NMDA exposure can lead to a delayed death of neurons. To address this issue, we performed whole-cell recording on acutely isolated hippocampal CA1 neurons to monitor the membrane response after NMDA exposure. Transient NMDA exposure (100 microM, 10 min) induced an inward current (postexposure current; Ipe) which was associated with a Ca2+- and Na+-permeable cation conductance. Ipe continuously increased (in the absence of NMDA) until death of the neuron occurred. Application of NMDA in the absence of extracellular calcium failed to trigger Ipe and neuronal death. Postexposure suppression of Ipe protected against NMDA toxicity. These results indicate that a cation current, which is induced by an increase in intracellular calcium concentration ([Ca2+]i) and is itself partly carried by Ca2+, links the initial NMDA exposure to neuronal death.

Kinetics of the thermal inactivation of alkaline phosphatase from green crab (Scylla serrata)

The kinetics of thermal inactivation of alkaline phosphatase from green crab (Scylla Serrata) has been studied using the kinetic method relating to the substrate reaction during irreversible inhibition of enzyme activity previously described by Tsou. The results show that the thermal inactivation of the enzyme is an irreversible reaction. Comparison of the microscopic rate constants for thermal inactivation of free enzyme and the enzyme-substrate complex shows that the presence of substrate has a certain protective effect against thermal inactivation.

An essential tryptophan residue of green crab (syclla serrata) alkaline phosphatase

The tryptophan residues in green crab (scylla serrata) alkaline phosphatase (EC 3.1.3.1) have been modified by N-bromosuccinimide (NBS). The modification of five tryptophan residues leads to complete loss of enzymatic activity. With the increase of NBS concentration, both the absorption at 278 nm and the fluorescence emission intensity at 335 nm of the modified enzyme decreased markedly indicating the modification of tryptophan residues. Quantitative treatment of the data (Tsou, Sci. Sinica 1962, 11, 1535-1558) shows that among the tryptophan residues modified, one is essential for its catalytic activity. The presence of the substrate markedly protects the modification of tryptophan residues as well as the inactivation, suggesting that the essential tryptophan residue is situated at the active site of this enzyme.

Kinetics of inactivation of green crab (Scylla Serrata) alkaline phosphatase during removal of zinc ions by ethylenediaminetetraacetic acid disodium

Green crab (Scylla Serrata) alkaline phosphatase (EC 3.1.3.1) is a metalloenzyme, the each active site in which contains a tight cluster of two zinc ions and one magnesium ion. The kinetic theory of the substrate reaction during irreversible inhibition of enzyme activity previously described by Tsou has been applied to a study on the kinetics of the course of inactivation of the enzyme by ethylenediaminetetraacetic acid disodium (EDTA). The kinetics of the substrate reaction with different concentrations of the substrate p-nitrophenyl phosphate (PNPP) and inactivator EDTA suggested a complexing mechanism for inactivation by, and substrate competition with, EDTA at the active site. The inactivation kinetics are single phasic, showing the initial formation of an enzyme-EDTA complex is a relatively rapid reaction, followed a slow inactivation step that probably involves a conformational change of the enzyme. Zinc ions are finally removed from the enzyme. The presence of metal ions apparently stabilizes an active-site conformation required for enzyme activity.

[3.3-style nurses' training goal made by the ABC analytical method]

Statistics of the structure of educational level and worked years of 140 occupied nurses, analysed by ABC curvegram, showed that the key training objects are class A (1 to 10 years at work) and class B nurses. Then the goal of nurses' training at work during 3 years for class A and B was made according to the difference of their classes and need of knowledge. In order to improve the effect of 3.3 style nurse training goal a method of two-direction teaching and assessing were applied, actual effect was achieved during a three-year conduction.

Kinetics of inhibition of green crab (Scylla serrata) alkaline phosphatase by phenylglyoxal

The kinetics method of the substrate reaction during modification of enzyme activity previously described by Tsou (Adv. Enzymol. Related. Areas Mol. Biol., 1988, 61, 381-436) has been applied to study the kinetics of the course of inactivation of green crab alkaline phosphatase by phenylglyoxal. The obtained results shows that the inactivation of the enzyme by phenylglyoxal is a slow reversible reaction. The microscopic rate constants for the reaction of the inhibitor with the enzyme were determined. The presence of substrate offers marked protection of this enzyme against inactivation by phenylglyoxal. The above results suggest that the arginine residue is essential for activity and is situated at the active site of the enzyme.

Kinetics of inhibition of alkaline phosphatase from green crab (Scylla serrata) by N-bromosuccinimide

The inactivation of alkaline phosphatase from green crab (Scylla serrata) by N-bromosuccinimide has been studied using the kinetic method of the substrate reaction during modification of enzyme activity previously described by Tsou [(1988), Adv. Enzymol. Related Areas Mol. Biol. 61, 381-436]. The results show that inactivation of the enzyme is a slow, reversible reaction. The microscopic rate constants for the reaction of the inactivator with free enzyme and the enzyme-substrate complex were determined. Comparison of these rate constants indicates that the presence of substrate offers marked protection of this enzyme against inactivation by N-bromosuccinimide. The above results suggest that the tryptophan residue is essential for activity and is situated at the active site of the enzyme.

Comparison of inactivation and unfolding of green crab (Scylla serrata) alkaline phosphatase during denaturation by guanidinium chloride

Green crab (Scylla serrata) alkaline phosphatase (EC 3.1.3.1) is a metalloenzyme, each active site in which contains a tight cluster of two zinc ions and one magnesium ion. Unfolding and inactivation of the enzyme during denaturation in guanidinium chloride (GuHCl) solutions of different concentrations have been compared. The kinetic theory of the substrate reaction during irreversible inhibition of enzyme activity previously described by Tsou [(1988), Adv. Enzymol. Related Areas Mol. Biol. 61, 381-436] has been applied to a study on the kinetics of the course of inactivation of the enzyme during denaturation by GuHCl. The rate constants of unfolding and inactivation have been determined. The results show that inactivation occurs before noticeable conformational change can be detected. It is suggested that the active site of green crab alkaline phosphatase containing multiple metal ions is also situated in a limited region of the enzyme molecule that is more fragile to denaturants than the protein as a whole.

Suppression of a Ca2+ current by NMDA and intracellular Ca2+ in acutely isolated hippocampal neurons

1. Ca2+ current was examined in acutely isolated hippocampal cells with the use of whole cell voltage-clamp recording and under continuous intracellular perfusion. A persistent Ca2+ current was activated by depolarization to -10 mV from a holding potential of -50 mV. 2. The persistent Ca2+ current was suppressed upon a wash out of the intracellular Mg(2+)-ATP. Adenosine 3',5'-cyclic monophosphate (cAMP) introduced intracellularly potentiated the Ca2+ current, and kinase A inhibitor blocked the current. 3. Reversible suppression of the persistent Ca2+ current was also observed by elevating intracellular Ca2+. This Ca(2+)-dependent suppression was retarded by the addition of a phosphatase inhibitor, okadaic acid, to the intracellular solution. 4. N-methyl-D-aspartate (NMDA) elicited inward current (NMDA response) in the isolated cells. The persistent Ca2+ current was transiently suppressed after the NMDA response. Suppression of the Ca2+ current by NMDA was reduced when intracellular Ca2+ buffering capacity was increased by increasing the concentration of bis-(o-aminophenoxy)-N,N,N',N'-tetraacetic acid (BAPTA) from a concentration of 1-10 mM. 5. Substitution of ATP in the intracellular solution with ATP-gamma-S or the addition of okadaic acid to the intracellular solution reduced the suppressive effect of NMDA on the Ca2+ current. 6. The results suggest that the persistent Ca2+ current in the hippocampal cells is maintained by a kinase A-mediated phosphorylation. Increases in the intracellular Ca2+ concentration suppressed the Ca2+ current via a mechanism involving a phosphatase. Ca2+ entry through the NMDA receptor channel suppressed the Ca2+ channel by activating the phosphatase.

Suppression of GABAA receptor responses by NMDA application in hippocampal neurones acutely isolated from the adult guinea-pig

1. In acutely isolated hippocampal cells, NMDA and glutamate application suppressed GABAA receptor-mediated responses. We studied the cellular events underlying the interaction between the two classes of receptors by using a whole-cell voltage-clamp approach. 2. Following an NMDA application, an outward current mediated by GABAA receptor activation (GABA response) was suppressed for up to 12 s. The suppression of the GABA response was reduced when Ca2+ in the extracellular solution was replaced by Ba2+ or when intracellular BAPTA (1,2-bis(O-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid) was increased from 1 to 10 mM. 3. Replacing ATP in the intracellular solution by adenosine-5'-O-3-thiotriphosphate reduced the suppressive effect of NMDA application on the GABA response. Okadaic acid, a phosphatase inhibitor, also prevented the NMDA-induced suppression of the GABA response. In addition, when the intracellular perfusing solution contained the calcineurin autoinhibitory fragment (50 microM), suppression of the GABA response by the NMDA current was also reduced. 4. Intracellular perfusion of an activated form of the Ca(2+)-dependent phosphatase, calcineurin, suppressed GABA responses. 5. The results show that NMDA responses elicited in hippocampal neurones transiently suppressed GABA responses. The data suggest that the functional linkage of the NMDA response with the GABA response was established via a Ca(2+)-dependent dephosphorylation process.

A new laser-ultrasound transducer for medical applications

A new type of probe is presented, which combines an ultrasound receiver constructed from piezoelectric polymer materials with a coaxial optical fibre for laser-induced ultrasound. The initial application of this probe, which may be further miniaturized, is in intra-arterial imaging and therapy. Overall diameters of the prototype probes presently range from 2.5 mm to 10.0 mm. Pulsed laser beams are introduced through the optical fibre to form a photoacoustic source within the material under investigation. Ultrasonic waves are induced in the material due to the photo-acoustic effect and received on return by a forward-looking piezoelectric polymer transducer. In principle, other high-power laser beams can also be introduced through the same optical fibre for therapeutic use. Initial development and characterization of this combined probe is reported in this paper, together with some results.

Analysis of tuberculous meningitis cases by an immunoblotting assay based on a mycobacterial antigen complex

Tuberculous meningitis cases were analyzed by an immunoblotting test based on Mycobacterium bovis BCG antigen complex A60. Anti-A60 immunoglobulin G (IgG) in cerebrospinal fluid (CSF) allowed early diagnosis, and concentrations decreased after recovery. In primary meningitis forms, anti-A60 IgGs were intrathecally synthesized and specific oligoclonal IgGs were present in CSF. In meningeal complications of pulmonary tuberculosis, there were matching titers of anti-A60 IgG in blood and CSF (mirror pattern). Correlation between CSF-restricted patterns and CSF pleocytosis was shown.

Different effects of intracellular and extracellular TEA on voltage-dependent K currents of acutely isolated hippocampal CA1 neurons

Tetraethylammonium (TEA) effects on K currents were examined on either side of the membrane of hippocampal CA1 neurons by means of whole-cell voltage-clamp recording and intracellular perfusion. Recording media contained ion channel blockers to allow the selective activation of voltage-dependent K currents which consisted of a rapidly decaying component (A-current) and a delayed component. Voltage protocols were applied to separate the A-current from the delayed component. Results show that 10 mM extracellular TEA suppressed 50 +/- 11% (S.D., n = 4) of the delayed current at different levels of depolarization but had little effect on the A-current. In contrast 10 mM TEA applied by intracellular perfusion suppressed the A-current by 42 +/- 10% (S.D., n = 4) in addition to inhibiting the delayed currently 55 +/- 15% (S.D., n = 4). Both the intracellular and extracellular actions of TEA on K currents showed no voltage- nor time-dependency. The results suggest that voltage-dependent transient current (A-current) is mediated through a separate group of ionic channels distinct from those that sustained the delayed current. Furthermore, the asymmetrical effects of intracellular and extracellular TEA on the transient current are similar to those described for the A-current in molluscan neurons. This observation supports the notion that the structure of the ion channel mediating the A-current is closely conserved across different species.

Hysteroscopic hydrotubation for treatment of tubal blockage

In order to increase the effectiveness of hydrotubation, a plastic cannula was inserted into the fallopian tube under hysteroscopic control. Fifty women with tubal blockage confirmed by HSG were selected for treatment. Hydrotubation solution consisted of hydrocortisone (20 mg), gentamicin (160,000 IU) and procaine (80 mg) in 20 ml distilled water. Repeat HSG was performed. After three treatments, tubal patency (one or both tubes) was achieved in 20 women (40%), and seven pregnancies resulted within 1-18 months. Hysteroscopic hydrotubation may be an alternative treatment for tubal blockage.

GABAA receptor function is regulated by phosphorylation in acutely dissociated guinea-pig hippocampal neurones

1. Current mediated by GABAA receptors was examined in pyramidal cells acutely dissociated from the hippocampus of mature guinea-pigs. Current responses were measured using whole-cell voltage-clamp recordings. An internal perfusion technique was used to change the intracellular contents during recording. 2. Application of GABA (100-300 microM) by short duration pressure pulses produced outward current responses at a holding potential of -10 mV. When recordings were made with intracellular solutions which did not contain Mg-ATP, GABA responses progressively decreased to less than 10% of their initial values after 10 min. This 'run-down' of the GABA response could not be accounted for by desensitization since the rate of run-down was not dependent upon agonist application. 3. The run-down of the GABAA response was reversed when Mg2+ (4 mM) and ATP (2 mM) were introduced into the intracellular perfusate. In addition to the presence of Mg-ATP, buffering of Ca2+ in the intracellular solution to low levels (approximately 10(-8) M) was also necessary to stabilize the GABAA response. 4. The role of a phosphorylation process in regulating the GABAA receptor was tested. After the GABA response stabilized, introduction of alkaline phosphatase (100 micrograms/ml) to the intracellular perfusate caused a complete run-down of the GABA response. 5. Stable GABA responses were obtained when ATP was replaced by ATP-gamma-S (adenosine 5'-O-(thiotriphosphate), an analogue of ATP that donates a thiophosphate group resulting in a product that is more resistant to hydrolysis. Following such treatment GABA responses declined more slowly after the introduction of intracellular alkaline phosphatase. 6. Run-down of GABA responses accelerated when intracellular Ca2+ concentration ([Ca2+]i) was elevated to about 5 x 10(-4) M. The run-down caused by elevated [Ca2+]i could be stopped and reversed by reducing [Ca2+]i to about 10(-8) M. 7. The introduction of ATP-gamma-S to the intracellular medium retarded the run-down of GABA responses caused by elevation of [Ca2+]i. 8. N-(6-Aminohexyl)-5-chloro-1-naphthalenesulphonamide (W-7), a calmodulin inhibitor, reduced the rate of run-down induced by elevated [Ca2+]i. 9. These results suggest that the function of the GABAA receptor is maintained by phosphorylation of the receptor or some closely associated regulatory molecule. Elevation of [Ca2+]i destabilizes the function of the GABAA receptor, probably by activating a Ca2+/calmodulin-dependent phosphatase.