Simultaneous determination and speciation of zinc, cadmium, lead, and copper in natural water with minimum handling and artifacts, by voltammetry on a gel-integrated microelectrode array

The paper reports a new approach based on a gel-integrated Hg-plated-Ir-based microelectrode array (GIME), for measuring Cu, Pb, Cd, and Zn speciation in natural waters. This paper focuses on the quantitative discrimination between mobile and colloidal metal species (size limit of a few nanometers), for which most classical separation techniques present severe drawbacks. Previous papers have shown qualitatively that GIME combined with square wave anodic stripping voltammetry (SWASV) has the basic characteristics required to discriminate between these two fractions directly on the unperturbed sample. In addition, because of the large sensitivity provided by GIME, complexation parameters (equilibrium constants and site concentrations) can be determined in little-perturbed samples, particularly without metal addition or with small addition compared with natural concentrations. The advantages of this procedure are exemplified and the possible artifacts occurring when titrating the sample with metals, in particular intermetallic compound formation and other problems, are discussed in detail. The present paper shows that the characteristics of GIME make it a unique tool to get quantitative information on metal speciation at nanomolar or even subnanomolar levels, with only minor sample handling.

Correlation between disparity for the minor histocompatibility antigen HA-1 and the development of acute graft-versus-host disease after allogeneic marrow transplantation

Results of a previous study suggested that recipient mismatching for the minor histocompatibility antigen HA-1 is associated with acute graft-versus-host disease (GVHD) after allogeneic marrow transplantation. In that study, most patients received either cyclosporine or methotrexate for GVHD prophylaxis, and a cytotoxic T-cell clone was used to test for HA-1 disparity. To facilitate large-scale testing, we developed a method that uses genomic DNA to identify HA-1 alleles. A retrospective study was conducted to correlate HA-1 disparity and the occurrence of acute GVHD in 237 HLA-A2-positive white patients who had received a marrow or peripheral blood stem cell transplant from an HLA-identical sibling. All patients received both methotrexate and cyclosporine for GVHD prophylaxis. The presence of HLA-A*0201 was confirmed in 34 of the 36 HA-1 disparate pairs by sequencing the HLA-A locus. Grades II-IV GVHD occurred in 22 (64.7%) of these 34 patients, compared with 86 (42.8%) of the 201 patients without HA-1 disparity (odds ratio, 2. 45; 95% confidence interval [CI], 1.15 to 5.23; P =.02). Recipient HA-1 disparity showed a trend for association with acute GVHD (odds ratio, 2.1; 95% CI, 0.91 to 4.68; P =.08) when a multivariable logistic regression model was used to include additional risk factors. These data are consistent with results of the previous study, suggesting an association between HA-1 disparity and risk of acute GVHD, but the strength of this association may be lower in patients who received both methotrexate and cyclosporine than in those who received methotrexate or cyclosporine alone.

[Primary study on HRV analysis of nonlinear dynamics in animal experiment]

The purpose of this study was to address the relationship between the parameters of nonlinear dynamics and functions of heart. We adopted the methods of nonlinear dynamics in observing the changes of the parameters of nonlinear dynamics under the conditions that sympathetic or parasympathetic nerve of heart exists singly as well as the coronary artery is narrowed. The results showed that in case the sympathetic or parasympathetic nerve was cut off the correlation dimension and entropy were lower than the normals, and in case the coronary artery was seriously narrowed the correlation dimension, entropy and laypunav exponent were also lower than the normals. The conclusion is that the parameters of nolinear dynamics can indicate the changes of the functions of autonomic nerve under the above conditions.

Definition of the gene encoding the minor histocompatibility antigen HA-1 and typing for HA-1 from genomic DNA

Recipient mismatching for the minor histocompatibility antigen HA-1 has been associated with acute graft-versus-host disease after allogeneic marrow transplantation. Two polymorphic nucleotides near an exon-intron junction of the gene encoding this minor histocompatibility antigen have been identified. In this study, we determined the genomic DNA sequence of the intron downstream from this polymorphic exon. Based on this sequence, primers were designed to amplify the genomic HA-1 gene sequence, and analysis of restriction fragment length polymorphisms was used to assign the HA-1 genotypes of 160 unrelated probands and a paired sibling for each proband. Among probands, the HA-1H allele frequency was 0.441, and the HA-1R allele frequency was 0.559. The distribution of HA-1 genotypes showed close fit with Hardy-Weinberg equilibrium. Likewise, the number of sibling pairs with disparity for HA-1 alleles showed close fit with predictions based on Hardy-Weinberg equilibrium. These results provide a simple and well validated method for future studies correlating HA-1 disparity with clinical outcome after allogeneic marrow transplantation.

[An in-vitro evaluation of the Sichuan Union Univ-I membrane lung and mathematical modeling calculation]

A new ELF hollow fibre lung, Sichuan Union Univ-I(SUU-I), constructed in our laboratory was tested in vitro to evaluate its oxygen transfer performance before it undergoes expensive animal trial. The test rig, conditions, procedure and the modelling method are introduced in the present paper. The results demonstrate that the Sichuan Union Univ-I membrane lung possesses the gas exchange ability claimed in the AAMI standards, and approaches the levels of the widely accepted membrane lungs, MAXIMA (Medtronic, US), SARNS(3M, US) and SAFE-II (Polystan, Denmark). The in vitro technique described in this paper proved practical, economical, and simple in the design and manufacturing of a new type membrane lung, as well as in research and development of membrane lungs.

[In vitro testing of the intravenacaval respiratory assist device (I)--Pressure drop characteristics and oxygen transfer performance]

The intravenacaval respiratory assist device(IVOX) of three different sizes developed by the present authors were evaluated experimentally in vitro. The tests using in turn two different test chamber materials(rigid and elastic) showed that a pressure drop occured. The pressure drop was higher in rigid test chamber than that in the elastic one, and the pressure drop difference between these two kinds of chamber increased with the diameter of the bundle of IVOX. Oxygen transfer rate, with water as the medium in the tests, was augmented with increasing water flow rate and gas flow rate, and with decreasing inlet oxygen concentration in water. It was concluded that, to avoid bubbles produced by IVOX, the gas flow rate should be controlled with fixed outlet water pressure, and vacancy be used in the effluent gas system.

[Study on effect of acupoint sticker of TTS-ST93-1 in treating motion sickness]

OBJECTIVE

To observe the effect of Transdermal Therapeutic System ST93-1 (TTS-ST93-1) by acupoint sticking in treating motion sickness (MS).

METHODS

One hundred and sixty-three young volunteers with history of MS recently were subjected to a 3 hours journey by track and armored car, and divided randomly into tested, positive control and negative control groups, treated with TTS-ST93-1 plaster, TTS-Scopolamine plaster and placebo (lactose plaster) respectively. The TTS-ST93-1 plaster was stuck on Neiguan (P6) or Shenque (CV8) or Qimai (TE18) point and the effect of treatment was observed by double-blind method.

RESULTS

The mean effective rate of tested group was 95.9%, which was significantly different to that of the negative control group (P < 0.01). In the tested group, the protection rate of plaster stuck on Shenque was 81.4%, on Neiguan was 45.5% and on Qimai was 100%, with an average of 76.0%, which was significantly different to that of the negative control group. The protection rate of TTS-Scopolamine plaster was merely 27.3%. The side effects of TTS-ST93-1 plaster were mouth dryness, sleepiness and fatigue, as compared with the negative control group, the difference was insignificant. No allergic reaction of skin such as swelling, pain or itching was found in the tested group.

CONCLUSION

Acupoint sticker of TTS-ST93-1 was an effective treatment for MS with less side effect and no allergic reaction of skin.

[Design and laboratory manufacture of "SUU-Type I" extra-luminal flow hollow fibre membrane oxygenator with microporous polypropylene]

The design and laboratory manufacture of "SUU-TYPE I" extra-luminal flow(ELF) hollow fibre membrane oxygenator are presented. The design is based on the O2 and CO2 transfer models in the cross-flow membrane oxygenator of Mockros and Pei. This paper also introduces the sketch of the membrane oxygenator, the structure of housing, the bundle of hollow fibres and the procedure of centrifugal potting. The self-made potting equipment and process of centrifugal potting are emphasized. The key know-how of centrifugal potting includes: (1) assuring the quality of the hollow fibre membrane material and the bundle; (2) calculating the quantity of potting material, polyurethane; (3) controlling reaction temperature; (4) removing gas from potting ends; (5) controlling rotation speed; (6) inserting the bundle in the house; (7) mastering the time of demoudling and cutting.

[Research and application of cardiopulmonary-cerebral resuscitation]

A novel concept of cardiopulmonary-cerebral resuscitation (CPCR) has been proposed, in which a combination of technologies of the membrane artificial lung, mild hypothermia, centrifugal blood pump, heparin coated surfaces and blood shunting have been used. The present paper introduces the modern conception, history of CPCR, with emphasis on the brain(cerebral) resuscitation. Importance of extracorporeal membrane oxygenation, mild hypothermia and centrifugal blood pump in cerebral resuscitation has been emphasized. Thereupon the new idea of the novel CPCR has been proposed and the design and laboratory manufacture of the equipment of CPCR will be carried out.

[Observation of EGG parameters during -6 degrees head-down bedrest for 21 days]

Electrogastography (EGG) was recorded in 15 healthy volunteers before and after meal during 21 days head down tilt -6 degrees bed rest. The results showed that nausea, distension and pain in the abdomen and loss of appetite appeared at the beginning of bed rest and body weight decreased significantly (P < 0. 01) after bed rest; Low frequency (Bradygastria) proportion of EGG (<2.4cpm) increased apparently after 8 days of bedrest, and there was significant difference (P <0.05) between preprandial and postprandial bradygastria. The dynamic parameters of bradygastria declined significantly and the rhythm of bradygastria increased with duration of bedrest. It indicates that simulated weightlessness may cause decrease of gastric rhythm and gastric motility.

Evaluation of pretransplant donor anti-recipient cytotoxic and helper T lymphocyte responses as correlates of acute graft-vs.-host disease and survival after unrelated marrow transplantation

We analyzed pretransplant donor anti-recipient cytotoxic and helper T lymphocyte (CTL and HTL) responses separately in two cohorts of unrelated marrow transplant recipients. Donors and recipients were typed for HLA-A and -B antigens by serologic methods, and for HLA-DRB1 by molecular methods. A single mismatch for a cross-reactive HLA-A or -B antigen or the -DRB1 allele was accepted in patients younger than 36 years if an HLA-A, -B, or -DRB1-matched donor could not be identified. The combination of methotrexate and cyclosporine was used for graft-vs.-host disease (GVHD) prophylaxis, and marrows were not T cell depleted. Donor anti-recipient CTL precursor frequencies showed no correlation with the severity of acute GVHD or with survival after transplantation. HTL responses were detected in the presence of HLA-class II disparity and showed weak correlations with the severity of acute GVHD (p = 0.054) and with survival after transplantation (p = 0.08). These results suggest that testing donor anti-recipient CTL responses before unmodified marrow transplantation does not predict clinically important events and is not likely to help select unrelated donors. With the current availability of molecular genetic methods for assessing HLA-class II compatibility, testing donor anti-recipient HTL responses is not likely to add information that would help select unrelated donors.

[The establishment and evaluation of abdominal aorta thrombosis model in rat]

An animal model of abdominal aorta thrombosis based on Virchow's thrombosis principle was induced by endothelium denudation with a polyethylene catheter combining severe stenosis with an aortic constriction in rats. A total of 37 rats were involved in thrombosis induction. Among them thrombus developed in 27 rats. Mean length of thrombus was 8.53 +/- 1.42 mm. The contractibility of vascular wall in the thrombotic group significantly reduced.

Examination of four HLA class I pseudogenes. Common events in the evolution of HLA genes and pseudogenes

The HLA class I gene family in lymphoblastoid cell line 721 has been studied in detail and a number of sequences in addition to the classical genes have been identified. The cloning, characterization, and nucleotide sequences of four sequences, all full length HLA class I pseudogenes, are described in this report. These pseudogenes, contained within 5.4-, 5.9-, 7.0-, and 9.2-kb HindIII fragments, each have the class I exon-intron structure as well as class I homology in their 5' and 3' flanking regions. However, all four sequences have one or more substitutions that perturb the coding region, leaving little doubt that they are in fact pseudogenes. Comparisons among these sequences and the HLA class I genes revealed that their homology with the class I genes is patchwork. Thus, although some regions have diverged, other contiguous intron-exon sequences are highly conserved. Comparisons in the 5' regions indicate that the pseudogene promoters more closely resemble the classical HLA promoters than the nonclassical promoters as none of the unique structural features found in the HLA-E, -F, or -G regulatory regions are present in any of the pseudogene promoters. Further comparisons revealed that at least two putative gene conversion events, similar to those hypothesized to have occurred in the evolution of some HLA genes, may have occurred in the evolution of some of the pseudogenes. These and other hypothetical events in the evolution of the class I gene family are discussed.

Examination of four HLA class I pseudogenes. Common events in the evolution of HLA genes and pseudogenes

The HLA class I gene family in lymphoblastoid cell line 721 has been studied in detail and a number of sequences in addition to the classical genes have been identified. The cloning, characterization, and nucleotide sequences of four sequences, all full length HLA class I pseudogenes, are described in this report. These pseudogenes, contained within 5.4-, 5.9-, 7.0-, and 9.2-kb HindIII fragments, each have the class I exon-intron structure as well as class I homology in their 5' and 3' flanking regions. However, all four sequences have one or more substitutions that perturb the coding region, leaving little doubt that they are in fact pseudogenes. Comparisons among these sequences and the HLA class I genes revealed that their homology with the class I genes is patchwork. Thus, although some regions have diverged, other contiguous intron-exon sequences are highly conserved. Comparisons in the 5' regions indicate that the pseudogene promoters more closely resemble the classical HLA promoters than the nonclassical promoters as none of the unique structural features found in the HLA-E, -F, or -G regulatory regions are present in any of the pseudogene promoters. Further comparisons revealed that at least two putative gene conversion events, similar to those hypothesized to have occurred in the evolution of some HLA genes, may have occurred in the evolution of some of the pseudogenes. These and other hypothetical events in the evolution of the class I gene family are discussed.

Cloning and physical mapping of the HLA class I region spanning the HLA-E-to-HLA-F interval by using yeast artificial chromosomes

The HLA class I genes are located within a 2-million-base pair (2-Mbp) region constituting the telomeric half of the human major histocompatibility complex. The large majority of the class I sequences, including the HLA-A, -E, -F, and -G genes, is found within the telomeric 1 Mbp. We report here the isolation and characterization of yeast artificial chromosome (YAC) clones that span a contiguous region of greater than 1.2 Mbp and include 14 of the 18 characterized class I sequences. Restriction enzyme mapping and the use of locus-specific probes have allowed all of the class I genes and sequences to be ordered and positioned within the region. In addition, the transcriptional orientation of the four class I genes has been determined. Using probes derived from the ends of YAC inserts and from class I pseudogenes, we describe a highly polymorphic region between the HLA-A and HLA-G genes. This region appears to be deleted in certain HLA haplotypes, shortening the distance between HLA-A and HLA-G by greater than 50 kilobase pairs (kbp). As part of the characterization of the YAC clones, unique sequence probes derived from the ends of each YAC insert were identified. When combined with probes derived from HLA genes and pseudogenes, 25 locus-specific probes spanning the 1.2-Mbp region have been identified for an average of 1 probe every 48 kbp.

Association of four HLA class III region genomic markers with HLA haplotypes

We have studied restriction fragment length polymorphism (RFLP) in the region 300 kb centromeric to the HLA-B locus. Four probes were used: one was genomic DNA derived from the tumor-necrosis factor (TNF)-beta gene, one was a cDNA for the BAT3 gene, and two single-copy genomic probes, R5A and M20A. The order of these markers from HLA-B towards the centromere is M20A, R5A, TNF and BAT3. The BAT3 and TNF-beta probes each detected two allelic bands with Taq I and Nco I digestion, respectively; the R5A and M20A probes each detected three polymorphic allelic bands with BstEII digestion. To determine if these restriction polymorphisms are preferentially associated with certain HLA-B and -DR haplotypes, a total of 153 HLA haplotypes was analyzed. The haplotypes A1, B8, DR3 and A3, B7, DR2 were each associated with a distinct combination of polymorphisms identified at these four sites, thereby demonstrating that the strong linkage disequilibrium characteristic of these haplotypes extends also to this segment of the class III region. In contrast, haplotypes that are not in positive linkage disequilibrium, such as A1,B8,DR4 and A2,B7,DR3, showed no preferential association with any of these polymorphisms. The antigens HLA-B27 and B35 were also found to be in positive linkage disequilibrium with RFLP patterns at three of these sites, and HLA-B14,B35,B44,Bw57 and Bw62 were found preferentially associated with polymorphisms at one or two of these sites, independent of the DR antigen present. These data further demonstrate that genetic linkage disequilibrium in the HLA class III region is complex and variable among different HLA haplotypes.

Delayed response to argon laser trabeculoplasty in monkeys. Morphological and morphometric analysis

In eight cynomolgus monkeys we performed argon laser trabeculoplasty and evaluated morphological changes in the trabecular meshwork (TM). Four weeks after laser treatment, the treated spots were detected as regions of flattened and collapsed beams covered by a cellular sheet extending from the corneal endothelium. The inner wall of Schlemm's canal beneath these regions was flat, with no vacuoles despite fixation with intraocular pressure maintained at 15 mm Hg. Adjacent nonlasered spots had wide open intertrabecular spaces with herniations of juxtacanalicular TM and of inner wall endothelium into and across the lumen of Schlemm's canal. The herniations contained chronic inflammatory cells and large vacuoles. Statistical morphometric analysis in three monkeys established that these herniations were significantly wider, more numerous, and contained more vacuoles than did control eyes. Our findings suggest that a biologic process is involved in these reactions to argon laser trabeculoplasty. Scarring is seen to obliterate TM in spots treated by the laser, and this apparently causes the flow of the aqueous humor to be diverted through adjacent nonlasered regions that become structurally altered to compensate for this overload of flow.

HLA polymorphisms in a Han Chinese population of Sichuan

This study reports the phenotype frequencies (PF) and gene frequencies (GF) of a homogeneous Sichuan Han Chinese population by typing of unrelated 229 individuals and 16 families for HLA-A, B, C, DR and DQ antigens. The frequencies of Bw67, Bw71, DRw12, DRw13 and DRw14 are the first to be reported in Chinese. Two two-locus haplotypes with significant linkage disequilibrium among the Sichuan have also been listed.

Short-term effect of argon laser trabeculoplasty in monkeys

We performed argon laser trabeculoplasty (ALT) in four cynomolgus monkeys and evaluated the morphologic changes in the trabecular meshwork one hour and 14 hours following the laser treatment. One hour after ALT, disruption of the trabecular beams and coagulative necrosis of the tissue were evident. Fragmented cells and fibrillar tissue debris were found in the trabecular spaces, accumulating in the juxtacanalicular region. This might explain the elevation of intraocular pressure seen immediately following ALT in some glaucomatous patients. Also, many trabecular endothelial cells were rounded up, displaying different stages of leaving the beams; these cells were actively phagocytic. Such stimulation of trabecular meshwork cells with subsequent removal of tissue debris might explain the temporary nature of elevation of intraocular pressure following ALT.

Q-switched neodymium-YAG laser trabeculopuncture in monkeys

In nine cynomolgus monkeys, trabeculopuncture was performed with a Q-switched neodymium-YAG laser, using a pulse energy of 5 to 7 millijoules and an exposure time of 14 nanoseconds. A penetration into Schlemm's canal was successfully achieved with two to four pulses; this penetration was accompanied by intraocular pressure (IOP) reduction and blood reflux into the anterior chamber. However, after eight days, IOP returned to baseline level, while white tissue was observed gonioscopically to fill in the puncture sites. Histologically, one hour after laser treatment, a blasting effect on the trabecular meshwork was observed with no signs of necrosis. Ater eight days, a hypertrophic scar formed, with the corneal endothelium extending over the scarred surface. At eight weeks and at six months after laser treatment, further shrinkage of the scar and the formation of a membrane over it was evident. Attempts to control scar formation by preventing blood reflux or injecting fluorouracil subconjunctivally for two weeks were unsuccessful. Scar formation at the trabecular puncture site severely limits the applicability of this potentially simple glaucoma treatment.